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1
McConnell, Claire Deborah. "Effects of chicken anaemia virus on cell-mediated immune function in chickens." Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317510.
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Martins, Nelson Rodrigo da Silva. "Studies of the immunoglobulin responses to viral infections of chickens." Thesis, University of Surrey, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254977.
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Echevarría-Núñez, Lisbeth E. "Role of Surface Molecules in Campylobacter jejuni Colonization and Virulence in Chickens." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/228452.
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Campylobacter spp. is one of the two major causes of foodborne illness throughout the world. Campylobacter accounts for the most common causes of diarrheal illness caused by bacterial pathogens worldwide and in the United States. It is estimated that Campylobacter diarrheal illness affects about 2.4 million persons every year with an estimated cost of treatment and loss of productivity exceeding $1 billion annually. Previous work in our laboratory on biofilms has demonstrated the presence pilus-like surface-associated structures disseminating from the cell wall of C. jejuni isolates not expressing flagella (flaAB mutants). To further investigate this finding, bioinformatics analysis, purification and identification of genes involved in the expression of surface-associated structures as well as mutational analysis of putative genes were performed. We identified two important poultry colonization factors in C. jejuni. These studies might provide insights in understanding the pathogenesis of C. jejuni. Moreover, it will provide a new target for potential vaccine development against C. jejuni infection in poultry production system. Thus directly impacting the number of C. jejuni infection in humans.
4
Law, Bibiana Felicity. "Assessment of the pathogenicity of Campylobacter jejuni from broiler chickens." Diss., The University of Arizona, 2005. http://hdl.handle.net/10150/282899.
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Sixty-three of 435 (14.5%) samples collected from broiler chickens were positive for C. jejuni. Twenty-two of 55 samples were from organic chickens (40%) and 41 of 380 samples were from conventional chickens (10.8%). Isolates were subjected to macrorestriction profiling using SmaI and analyzed for their ability to survive in macrophage cells and invade in epithelial cells. Antibiotic testing to cefaclor, ciprofloxacin, tetracycline, erythromycin, gentamicin, trimethroprim/sulfamethoxazole, and ampicillin were performed. Finally, 5 isolates of varying putative in vitro virulence traits were chosen for experimental inoculation of newborn piglets. Five piglets per isolate were tested and examined macroscopically and microscopically upon necropsy. Genotyping of isolates indicated 1 to 3 profiles per flock. Of the 22 organic isolates from chickens, only 3 (13.6%) were able to survive within macrophages. For the conventional isolates, 21 out of 41 (51.2%) were able to survive. However, the majority of isolates (90.5%) from both organic and conventional isolates were not capable of invading epithelial cells. No isolates exhibited resistance to ciprofloxacin or gentamicin. One isolate out of 63 (1.6%) was resistant to erythromycin, 52 (82.5%) to tetracycline, 28 (44.4%) to trimethroprim/sulfamethoxazole, and 6 (9.5%) to cefaclor. In terms of the piglet studies, regardless of the combination of in vitro invasion or survival results or type of flock, most piglets (16/25) in all groups exhibited hyperemia, edema, and hemorrhage in the small intestine or colon upon gross examination. Microscopic examination revealed congested mucosa and erosion of the epithelium in 10 of the 25 piglets from 4 of the 5 groups. In conclusion, this study suggests that C. jejuni isolated from broiler chickens are virulent in piglets and are probably capable of causing disease in humans. Furthermore, the results of the survival and invasion assays did not correlate with the results of the piglet studies and cannot be relied upon to predict degree of virulence. Therefore, another virulence factor is responsible for the pathogenesis, such as a toxin(s). As this is the first study to confirm putative in vitro virulence traits with an animal model, further research is recommended with the piglet model to assess pathogenicity.
5
Kinsey, Yvette E. "The effect of the inclusion of probiotic micro-organisms in the diet of growing chickens." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307940.
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Nicholas, Robin Ashley John. "Studies on the development and application of an ELISA for the detection of antibody to Salmonella enteritidis in chickens and their eggs." Thesis, Brunel University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306853.
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Hu, Jinxin. "Molecular and genetic studies of resistance to infection with Salmonella typhimurium in chickens." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0001/NQ44455.pdf.
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Abundo, Michael Edward Cruz. "Evaluation of sampling methods for the study of respiratory bacterial microbiota in chickens." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574851946483897.
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Armstrong, Alexandra Edwards. "Salmonella in an Oyster Production and Small Feedlot Environment, Use of Novel Proteins Expressed by an Attenuated Salmonella Vector for the Reduction of Campylobacter Colonization in Broiler Chickens." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/228492.
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The CDC estimates that 48 million illnesses, 128,000 hospitalizations, and 3,000 deaths annually are attributable to foodborne illnesses, making their impact significant in terms of both human health and economic losses (3). Estimates vary, but it is frequently stated that Campylobacter species affect 2.4 million people annually (28). Among bacterial foodborne pathogens it is second in the US only to Salmonella, which in recent years has consistently been the most frequently reported, most likely to cause hospitalization, and deadliest foodborne bacterial illness in the US (3, 106).In order to reduce the burden of illness caused by these pathogens and improve the safety of our food supply, continued investigation of the epidemiology, transmission and interactions of these organisms with their environments is necessary. Additionally, prevention of colonization within natural reservoirs of these bacteria which contribute to contamination of foods is an important step in the reduction of the burden of foodborne illness. This work examines the relationship of Salmonella to oysters and the aquatic environment in which they are raised, the interactions of Salmonella in a small feedlot environment, and the reduction of colonization of broiler chickens by Campylobacter jejuni through vaccination with recombinant attenuated Salmonella vectors into which novel Campylobacter genes had been cloned. It was found that while Salmonella is still sporadically present on the West Coast of the US, an area where oysters were previously found to be positive for the organism, the strain which predominated in the last study of that area is reduced in prevalence. Additionally, it was found that that strain does not possess special fitness in oysters or the aquatic environments in which they are raised, though Salmonella survives in oysters and water samples longer than a representative coliform. Salmonella is also present in the small feedlot environment sampled, and animal stress appears to play a role in the shedding of the organism in that environment, leading to the potential contamination of beef carcasses during processing. Reduction of colonization by C. jejuni in broilers was achieved in the case of both vaccines, with a maximum reduction of four logs as compared to controls.
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Pisula, Anneka. "Detecting a Probiotic Product Within the Gut of Broiler Chickens." DigitalCommons@CalPoly, 2018. https://digitalcommons.calpoly.edu/theses/1921.
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As of January 2017, the U.S. poultry industry banned the use of antibiotics and now relies on alternatives such as probiotics to help protect animal health. Although probiotic use is not a new concept in the poultry industry, identifying the best combination of bacterial strains to generate an effective probiotic formula requires further investigation. This study aimed to detect a probiotic product of four bacterial strains (Pedioccoccus acidilactici, Pediococcus pentosaceus, Lactobacillus plantarum, and Bacillus subtilis) in a feeding trial with broiler chickens. Birds given the probiotic were predicted to show an improved growth performance with the probiotics colonizing the gut. Ninety-six broiler chickens were equally divided into 3 treatment and 3 control pens. During the 25-day experiment, birds were fed a starter diet (days 0-11) and a grower diet (days 12-25). Experimental birds were administered the probiotic product via the drinking water at a concentration of 3.1×104 CFU/ml. Control birds had an equivalent amount of dextrose filler added to their water supply. Feces were collected hourly on day one and daily thereafter. On days 1, 22, and 25 of the experiment, 2 birds from each pen were euthanized for gut sampling. Lumen and mucosa samples were collected from the duodenum, jejunum, ileum, and ceca. Species-specific and strain specific PCR primers were employed for probiotic detection. Wild strains of P. acidilactici, P. pentosaceus, and L. plantarum were detected in the feeds, inhibiting detection of the probiotic strains when using species-specific PCR primers. Strain-specific primers were used to detect the probiotic Pedioccoccus acidilactici and Lactobacillus plantarum strains. B. subtilis was detected in feces within one hour of probiotic administration and was predominantly detected in experimental birds only. Both P. acidilactici and L. plantarum probiotic strains were initially detected in the feces of treated birds within two hours of probiotic administration and again ten days later. Both L. plantarum and B. subtilis were seen only in treated bird gut samples. L. plantarum was predominantly detected in the ceca near the end of the small intestine. P. pentosaceus was observed more often in treated gut samples and P. acidilactici was the least commonly detected probiotic strain. All administered bacteria were rarely seen in mucosa samples. Feed-endogenous P. acidilactici and L. plantarum strains became progressively more detectable in the mucosa along the gastrointestinal tract suggesting gut colonization, however, probiotic strains did not appear to colonize the mucosa of treated birds. Although probiotic strains were no longer detected after product removal, all probiotic strains were detected in feces and gut samples during probiotic administration, suggesting the bacteria can colonize the gut. Probiotic supplementation did not result in significant differences in body weight gain, feed intake, or feed conversion ratio. However, birds growing in a more stressful environment than the carefully controlled experimental set up used here may show probiotic-related effects. This study identified that the probiotic bacteria appeared to survive the gastrointestinal tract, exhibited a transit time of 1-2 hours, could possibly colonize chickens, and localized near the end of the chicken gut.
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Pedroso, Antonio Carlos. "Modulação da resposta imune em aves imunizadas com vacinas aviárias associadas ao b-glucano." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-23102009-090556/.
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Os b-glucanos são formados por polissacarídeos estruturais da parede celular de leveduras (Saccharomyces cerevisiae), alguns cereais em grãos e fungos. Os b-glucanos apresentam a molécula de glicose ligada ao carbono nas posições b-1,3 e pode apresentar cadeias laterais com o resíduo de glicose ligado nas posições b-1,6. O b-glucano tem sua ação benéfica como antiinflamatório, antitumoral, hipocolesterolêmico e hipoglicêmico. A inocuidade do b-glucano solubilizado nesse trabalho foi demonstrada in vitro, em cultivo celular de fibroblastos de embriões de galinhas SPF, e confirmado in vivo após a injeção no músculo peitoral de frangos. O b-glucano é um modulador biológico devido sua capacidade de em aumentar a resposta imune inata, aumentando os mecanismos inespecíficos de defesa dos animais. O b-glucano solúvel na dose de 240 mg/ave, associado ao diluente da vacina de Marek, apresentou efeito imunomodulador na resposta imune humoral. Os níveis de IgG no plasma foram detectados pela técnica de ELISA, e a resposta imune celular foi avaliada pela detecção de IFNg-, IL-2 e IL-6 em frangos vacinados com vacina recombinante e viva contra doença de Gumboro. O b-glucano solúvel nesse experimento demonstrou ser um potente imunoadjuvante após aumentar a resposta imune humoral e celular para os antígenos da doença infecciosa da Bursa, quando associado em vacinas recombinantes e vivas.<br>The b-glucans are structural polysaccharides from yeast cell wall (Saccharomyces cerevisiae), some cereal grains and fungi. The b-glucans have a glucose molecule carbon linked in sites b-1,3 and they have side chains of glucose residue in sites b-1,6. The b-glucans have a helpful effect as anti-inflammatory, antitumoral, hypoglycemic and hypocholesterolemic activity .The safety of b-glucan water-soluble obtained in this work was demonstrated in vitro, using specific-pathogen-free (SPF) cell culture chicken embryo fibroblast and it was confirmed in vivo after injection in chicken pectoral muscle. The b-glucan is a biological modulator due to its ability to increase the innate immune response. The soluble b-glucan in 240 mg/bird dose, associated to Marek\'s disease vaccine diluents showed immunomodulatory effect in humoral immune response. The IgG plasma levels were detected by ELISA method, and the cellular immune response was evaluated by detection IFN-g, IL-2 and IL-6 in vaccinated chickens with recombinant and live vaccines against Gumboro\'s disease using Real-Time PCR technique. The soluble b-glucan used in this trial demonstrated a powerful immune-adjuvant effect enhancing the cellular and humoral immune response against Bursal disease, when associated to recombinant vaccine and live vaccines.
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Cressman, Michael David. "A molecular approach to understanding the interrelation between the microbiomes in the litter and intestines of commercial broiler chickens." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1243872965.
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Ashraf, Shamaila. "Studies on infectious bursal disease virus." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1124124381.
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Thesis (Ph. D.)--Ohio State University, 2005.<br>Title from first page of PDF file. Document formatted into pages; contains xvi, 216 p.; also includes graphics (some col.). Includes bibliographical references (p. 180-216). Available online via OhioLINK's ETD Center
14
Phenix, Kerry Victoria. "Molecular characterization of chicken anaemia virus." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241429.
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Massoli, Mariana Casteleti Beraldo [UNESP]. "Avaliação da qualidade microbiológica de peito, coxa e coração de frango comercializados em diferentes estabelecimentos da cidade de Jaboticabal, SP." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/94919.
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massoli_mcb_me_jabo.pdf: 488238 bytes, checksum: 695803220e7404c7dbd9a93afa12ac49 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Carcaças e miúdos de frangos podem ser veiculadores de bactérias patogênicas para o homem, provocando intoxicações alimentares. A contaminação da carne de frango pode ocorrer desde a sua criação até a manipulação das peças durante e após a comercialização. Considerando isto, o objetivo do trabalho foi o de avaliar a qualidade microbiológica de peito, coxa e coração de frangos comercializados em seis diferentes estabelecimentos na cidade de Jaboticabal, através da pesquisa dos patógenos reconhecidos como principais indicativos de manipulação inadequada e consequente contaminação desse alimento. De 57 amostras analisadas verificou-se que 3 (5,5%) delas apresentava o número de mesófilos totais acima do limite permitido, e que todas as amostras foram positivas para enterobactérias, sendo 10 (18,5%) dessas foram identificadas como Escherichia coli. Ainda em 35 amostras (65%) foram detectadas para o gênero Staphylococcus dos quais 10 (29%) foram identificados como Estafilococos coagulase positiva, pelos quais o teste de sensibilidade a antimicrobianos mostrou uma cepa resistente a eritromicina. Uma amostra foi positiva para Clostridium perfringens cuja a presença não é permitida nas normativas vigentes. O Número Mais Provável de coliformes totais foi confirmado em 89% das amostras e 56% foram positivas para NMP de coliformes termotolerantes; duas amostras de coliformes totais e uma de coliforme termotolerante estavam fora dos padrões. Conclui-se que a conservação, a manipulação e o armazenamento de frango são de grande importância, uma vez que a presença dos microrganismos encontrados pode ser responsável pela deterioração dos alimentos e intoxicações alimentares. A resistência a eritromicina é preocupante, pois ainda é considerado um antibiótico seguro para medidas terapêuticas.<br>Carcasses and offal of chickens may carry pathogenic bacteria to humans, causing food poisoning. Contamination of chicken meat may occur from its creation to the manipulation of parts during and after the sale. Considering this, the objective was to evaluate the microbiological quality of breast, thigh and heart of chicken sold in six different establishments in the town of Jaboticabal, through the detection of the pathogens recognized as the key indicators of mishandling and resulting contamination of food. In 57 samples it was found that 3 (5.5%) of them had the total number of bacteria above the limit, and that all samples were positive for Enterobacteriaceae, 10 (18.5%) of these were identified as E. coli. Also in 35 samples (65%) were detected for the genus Staphylococcus of which 10 (29%) were identified as coagulase-positive staphylococci, for which the test disk diffusion showed a strain resistant to erythromycin. A sample was positive for Clostridium perfringens whose presence is not allowed under current regulations. The most probable number of coliforms was confirmed in 89% of the samples and 56% were positive for MPN of coliforms, two samples of total coliform and thermotolerant coliform were out of the box. We conclude that the conservation, handling and storage of chicken are of great importance, since the presence of microorganisms may be found responsible for food spoilage and food poisoning. Resistance to erythromycin is worrisome because it is still considered a safe antibiotic for therapeutic measures.
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Massoli, Mariana Casteleti Beraldo. "Avaliação da qualidade microbiológica de peito, coxa e coração de frango comercializados em diferentes estabelecimentos da cidade de Jaboticabal, SP /." Jaboticabal : [s.n.], 2010. http://hdl.handle.net/11449/94919.
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Orientador: Ruben Pablo Schocken-Iturrino<br>Banca: Helio José Montassier<br>Banca: Maria Luiza Poiatti<br>Resumo: Carcaças e miúdos de frangos podem ser veiculadores de bactérias patogênicas para o homem, provocando intoxicações alimentares. A contaminação da carne de frango pode ocorrer desde a sua criação até a manipulação das peças durante e após a comercialização. Considerando isto, o objetivo do trabalho foi o de avaliar a qualidade microbiológica de peito, coxa e coração de frangos comercializados em seis diferentes estabelecimentos na cidade de Jaboticabal, através da pesquisa dos patógenos reconhecidos como principais indicativos de manipulação inadequada e consequente contaminação desse alimento. De 57 amostras analisadas verificou-se que 3 (5,5%) delas apresentava o número de mesófilos totais acima do limite permitido, e que todas as amostras foram positivas para enterobactérias, sendo 10 (18,5%) dessas foram identificadas como Escherichia coli. Ainda em 35 amostras (65%) foram detectadas para o gênero Staphylococcus dos quais 10 (29%) foram identificados como Estafilococos coagulase positiva, pelos quais o teste de sensibilidade a antimicrobianos mostrou uma cepa resistente a eritromicina. Uma amostra foi positiva para Clostridium perfringens cuja a presença não é permitida nas normativas vigentes. O Número Mais Provável de coliformes totais foi confirmado em 89% das amostras e 56% foram positivas para NMP de coliformes termotolerantes; duas amostras de coliformes totais e uma de coliforme termotolerante estavam fora dos padrões. Conclui-se que a conservação, a manipulação e o armazenamento de frango são de grande importância, uma vez que a presença dos microrganismos encontrados pode ser responsável pela deterioração dos alimentos e intoxicações alimentares. A resistência a eritromicina é preocupante, pois ainda é considerado um antibiótico seguro para medidas terapêuticas.<br>Abstract: Carcasses and offal of chickens may carry pathogenic bacteria to humans, causing food poisoning. Contamination of chicken meat may occur from its creation to the manipulation of parts during and after the sale. Considering this, the objective was to evaluate the microbiological quality of breast, thigh and heart of chicken sold in six different establishments in the town of Jaboticabal, through the detection of the pathogens recognized as the key indicators of mishandling and resulting contamination of food. In 57 samples it was found that 3 (5.5%) of them had the total number of bacteria above the limit, and that all samples were positive for Enterobacteriaceae, 10 (18.5%) of these were identified as E. coli. Also in 35 samples (65%) were detected for the genus Staphylococcus of which 10 (29%) were identified as coagulase-positive staphylococci, for which the test disk diffusion showed a strain resistant to erythromycin. A sample was positive for Clostridium perfringens whose presence is not allowed under current regulations. The most probable number of coliforms was confirmed in 89% of the samples and 56% were positive for MPN of coliforms, two samples of total coliform and thermotolerant coliform were out of the box. We conclude that the conservation, handling and storage of chicken are of great importance, since the presence of microorganisms may be found responsible for food spoilage and food poisoning. Resistance to erythromycin is worrisome because it is still considered a safe antibiotic for therapeutic measures.<br>Mestre
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Duggett, Nicholas A. "High-throughput sequencing of the chicken gut microbiome." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6678/.
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The chicken (\(Gallus\) \(gallus\) \(domesticus\)) is the most abundant and widely distributed livestock animal with a global population of over 21 bill ion. A newly hatched broiler chick increases its body weight by 25% overnight and 50-fold over five weeks. The symbiotic, complex and variable community of the microbiome forms an important part of the gastrointestinal tract (gut). It is involved in gut development, biochemistry, immunology, physiology and non-specific resistance to infection. This study investigated the chicken gut microbiota using high-throughput 16S rRNA sequencing and culture-based techniques. There was specific interest in the proventriculus of which there is limited research currently in the literature and the caecum because it contains the highest density of bacterial cells in the gut at 10\(^1\)\(^1\) per gram. The results showed no significant difference in the first stages of the gut which shared a low-diversity microbiota dominated by a few \(Lactobacillus\) species. The microbiota becomes more diverse in the latter pa1ts of the small intestine where \(C/ostridiales\) and \(Enterobacteriaceae\) were present in higher numbers. The caecum was the most diverse organ with the majority of species belonging to Ruminococcaceae, Lachnospiraceae and \(Alistipes\). A number of novel species were isolated from the chicken gut and six of these were whole-genome sequenced.
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Mukiibi-Muka, G. "Studies on local and systemic antibody responses in chicken to avian reovirus infections." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364346.
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Muhammad, Khushi. "In vitro studies of chicken macrophages and their role in Salmonella-related immunization failure." Thesis, University of Surrey, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332302.
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Simon, Stephanie E. "Cloacal Microbiota of Captive-bred and Wild Attwater’s Prairie-chicken, Tympanuchus Cupido Attwateri." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc699867/.
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The Attwater’s prairie-chicken (Tympanuchus cupido attwateri; APC) is a species of grouse native to Texas coastal prairies and is on the critically endangered species list as a result of habitat destruction and overhunting. All of the current populations were captively bred and released into the wild. Survivorship for released APCs is very low, and individuals seldom survive to reproduce in the wild. One factor contributing to this may be an alteration in the gut microbiota as a result of captivity. Factors potentially influencing the gut microbial composition in captivity include antibiotic therapy, stress, and a predominantly commercially formulated diet. Recent studies have begun to shed light on the importance of the host microbial endosymbionts. Antibiotic administration, stress, diet, age, genotype and other factors have been shown to influence microbial populations in the gastrointestinal tracts of many different vertebrates. Sequencing of 16S rRNA gene amplicons on the Ion Torrent™ platform was used in this study to identify groups of bacteria in the cloacas as a surrogate for the gut microbiota in the APC. Antibiotic-treated and untreated birds, wild-hatched and captive-bred birds, and individuals sampled before and after release to the wild were examined. Significant differences were found between wild-hatched and captive raised birds both pre- and post release. In addition, there was extensive variation among the populations at the lower taxonomic ranks between individuals for each group of APCs. Principal coordinate analysis based on the weighted UniFrac distance metric further exhibited some clustering of individuals by treatment. These data suggest that captive breeding may have long-term effects on the cloacal microbiota of APCs with unknown consequences to their long-term health and survivorship.
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Okamoto, Adriano Sakai [UNESP]. "Avaliação histopatológica e imunológica da mucosa intestinal de aves tratadas com Lactobacillus spp. desfiadas com Salmonella Enteritidis." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/95987.
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okamoto_as_me_botfmvz.pdf: 447893 bytes, checksum: c07517a80a90c273e0c642d883569d57 (MD5)<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>Este estudo foi conduzido com o objetivo de avaliar a capacidade protetora de Lactobacillus spp. em frangos de corte desafiados com Salmonella Enteritidis, utilizando-o como tratamento no primeiro dia de idade, e posterior desafio com Salmonella Enteritidis fagotipo 04, observando-se possíveis alterações histopatológicas e imunológicas na mucosa intestinal, como o comprimento das vilosidades, a produção de imunoglobulina A e o peso corporal. Foi observada maior eficácia do tratamento com Lactobacillus spp. somente quando as aves foram desafiadas com Salmonella Enteritidis aos 21 dias de idade. O comprimento das vilosidades intestinais apresentou-se reduzido após os desafios, mostrando posterior regeneração. Com o desafio de Salmonella Enteritidis ocorrendo no terceiro dia de idade, verificou-se que aves jovens possuem maior sensibilidade à infecção.<br>This study was driven with the objective of evaluate the protective capacity of Lactobacillus spp. in chickens challenged with Salmonella Enteritidis, utilizing as handling on one-day old chicks and posterior challenge with Salmonella Enteritidis phagotype 04, observing possible histopathological and immunological alterations in the intestinal mucosa, like the length of the villus, the production of immunoglobulin A and body weight. Greater efficacy in the treatment with Lactobacillus ssp. was observed only when the chicks were challenged with Salmonella Enteritidis at 21 days old. The length of the intestinal villus always diminished after challenge, regenerating later. After the first challenge of with Salmonella Enteritidis (at three-days old), we verified that young chicks possess a greater sensibility to infection.
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Boufleur, Róger. "Campylobacter jejuni EM FRANGOS DE CORTE, CARNE E VÍSCERAS DE FRANGO NO RIO GRANDE DO SUL E EFEITO DO CONGELAMENTO SOBRE A CONTAMINAÇÃO NOS CORTES." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/10044.
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Campylobacteriosis, in the current days, is recognized as the major cause of foodborne illness in many developed and developing countries. Among the Campylobacter species
responsable for the infections, C. jejuni is responsable for 75% of the cases of human campilobacteriosis, as for it, it s considered as the major species involved on the
registered cases. In this work, two experiments were conduced. In the first, the presence of C. jejuni and Campylobacter spp. in poultry farms of Rio Grande do Sul State in Brazil was investigated. Epidemiological data was obtained with the person encharged by the farms, and the data obtained was corelated with the levels of contamination of each property. In the second experiment, we investigated the contamination of cicken meat
and giblets adquired in supermarkets in Santa Maria city of C. jejuni as well as the freezing effect on the contamination levels in this samples. For the first trial, 280 cloacal swabs were collected from four poultry farms. In the second experiment, 9 samples of heart, liver, gizzard and drumette, tottalizing 36 samples collected. A portion of each sample was processed freshly, while the rest was freezed (-18ºC) for 7 days before it s
processing. In the first trial, 147 samples (52,5%) were positive for C. jejuni and another 31 (11,07%) were identified as Campylobacter spp. The data analysis revealed
correlaction beetwen the number of birds kept in de farms (p=0,05), the age of the poultry (p=0,05) and the gender (p=0,03), as female was more infected than males. In
the second experiment, isolation of C. jejuni was achieved in 7 heart (77,7%), 8 liver (88,8%), 4 gizzard (44,4%) and 3 drumette (33,3%) fresh samples, corresponding to
61,1% of total samples. After freezing storage, in only 3 samples (two liver and one heart) C. jejuni was isolated (8,3%). The data obtained allowed us to conclude that C.
jejuni is widely spread in poultry farms os Rio Grande do Sul state, so, improve the control procedures for Compylobacter species on the poultry fars is needed. The
chicken cuts obtained from supermarkets in Santa Maria city are also higly contaminated by C. jejuni, however, freezing storage for seven days can drastically reduce the
contamination levels of chicken cuts, improoving food safety, althoght, this procedure do not eliminate completely C. jejuni from de cuts analized, and the correct manipullation is needed to eliminate the risk of infeccion from poultry meat sources .<br>A campilobacteriose, atualmente, é reconhecida como sendo a causa mais freqüente de infecção de origem alimentar em seres humanos. Dentre as espécies responsáveis pela
infecção, Campylobacter jejuni responde por cerca de 75% dos casos de campilobacteriose humana, sendo considerada a principal espécie envolvida nos casos registrados. Este trabalho é composto de dois experimentos. No primeiro avaliou-se a ocorrência de C. jejuni em granjas avícolas no estado do Rio Grande do Sul, correlacionando os índices de contaminação detectados com dados epidemiológicos
obtidos através de entrevista com o responsável pela granja. Foram coletados 280 swabs cloacais oriundos de quatro granjas avícolas do Rio Grande do Sul. No segundo
experimento, foram adquiridos em supermercados de Santa Maria, 9 amostras frescas de fígado, coração, moela e drumete, totalizando 36 amostras. Foi realizado o
processamento de um fragmento de 25g de cada amostra fresca, sendo o restante congelado à -18ºC durante sete dias, sendo as amostras, após este período novamente
analisadas. No primeiro experimento, foram obtidas 147 amostras (52,5%) positivas para C. jejuni e 31 amostras (11,07%) identificadas como Campylobacter spp. A análise
dos dados revelou existir influência dos índices de contaminação mais elevados com o número de aves alojadas (p=0,05), tempo de alojamento (p=0,05) e sexo (p=0,05),
sendo as fêmeas mais acometidas que os machos. No segundo experimento, realizou-se o isolamento em 7 (77,7%) amostras frescas de coração, 8 (88,8%) de fígado, 4
(44,4%) de moela e 3 (33,3%) de drumete, correspondendo a 61,1% das amostras frescas analisadas. Após o congelamento, em apenas três amostras (8,3%) foi obtido o
isolamento de C. jejuni, sendo duas amostras de fígado e uma de coração. Os dados obtidos permitem concluir que C. jejuni está amplamente difundido na avicultura industrial do Rio Grande do Sul, sendo necessário ampliar os esforços para redução deste patógeno nos plantéis avícolas. Os cortes de frango adquiridos em supermercados na cidade de Santa Maria apresentam índices de contaminação elevados por C. jejuni, contudo o congelamento por 7 dias é capaz de reduzir
consideravelmente os índices de contaminação, porém, não eliminando completamente C. jejuni dos cortes congelados, assim, a manipulação adequada da carne de frango
continua sendo essencial para assegurar a eliminação de C. jejuni dos alimentos contendo carne de frango em suas preparações.
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Gibbons, Brian. "The use of desmin as an insoluble antigen in the immunochemical identification of pork and chicken meats." Thesis, Nottingham Trent University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263939.
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The muscle specific intermediate filament protein, desmin, was shown to be a potentially useful insoluble antigen for the production of pork specific monoclonal antibodies and in the development of poultry meat specific immunoassays. Differential extraction and chromatographic purification procedures were optimised for the recovery of desmin from smooth and skeletal muscles in forms suitable for antibody production. Desmin of sufficient purity for the production of monoclonal antibodies was obtained using differential extractions followed by an anion exchange step and then a gel filtration step. Very pure desmin necessary for the production of polyclonal antibodies was obtained using electro-elution from SDS-PAGE of desmin enriched samples prepared by differential extraction only. Although smooth muscle was a rich source for desmin it was found that pork specific monoclonal antibodies produced with this immunogen were also tissue specific in simple assay formats and thus did not react with desmin enriched extracts of pork steak. Those antibodies that did react with extracts of pork steak also reacted with similar extracts of beef skeletal muscle. As a result of these findings, improvements to the extraction and purification procedures were made and applied to the recovery of pure desmin from pork skeletal muscle. Anti-desmin antibodies were recovered from the single successful fusion performed but none were found to be pork specific. Although outside the remit of this project it was noted that the tissue specificity of some of the anti-pork desmin antibodies may suggest a hitherto unrecognised tissue dependent post-translational modification of desmin. Polyclonal sera obtained from rabbits immunised with pure smooth muscle desmin obtained from pig stomach cross-reacted extensively with similar smooth and skeletal muscle extracts of beef, lamb and chicken. Although not species specific, these sera could be used as revealing antibodies in two site assays should a pork specific antiskeletal muscle antibody be created. Immunoassays for the detection and quantitation of chicken in beef were developed using the poultry specific monoclonal antibody 4B4/B2 produced in this laboratory by Dr. Ruth Bevan. An indirect antibody capture type ELISA was developed capable of detecting 10% w/w contamination of minced beefsteak with chicken meat along with a indirect Western blot technique capable of detecting 2% w/w contamination of minced beefsteak with chicken meat
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Okamoto, Adriano Sakai. "Avaliação histopatológica e imunológica da mucosa intestinal de aves tratadas com Lactobacillus spp. desfiadas com Salmonella Enteritidis /." Botucatu : [s.n.], 2005. http://hdl.handle.net/11449/95987.
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Orientador: Raphael Lucio Andreati Filho<br>Resumo: Este estudo foi conduzido com o objetivo de avaliar a capacidade protetora de Lactobacillus spp. em frangos de corte desafiados com Salmonella Enteritidis, utilizando-o como tratamento no primeiro dia de idade, e posterior desafio com Salmonella Enteritidis fagotipo 04, observando-se possíveis alterações histopatológicas e imunológicas na mucosa intestinal, como o comprimento das vilosidades, a produção de imunoglobulina A e o peso corporal. Foi observada maior eficácia do tratamento com Lactobacillus spp. somente quando as aves foram desafiadas com Salmonella Enteritidis aos 21 dias de idade. O comprimento das vilosidades intestinais apresentou-se reduzido após os desafios, mostrando posterior regeneração. Com o desafio de Salmonella Enteritidis ocorrendo no terceiro dia de idade, verificou-se que aves jovens possuem maior sensibilidade à infecção.<br>Abstract: This study was driven with the objective of evaluate the protective capacity of Lactobacillus spp. in chickens challenged with Salmonella Enteritidis, utilizing as handling on one-day old chicks and posterior challenge with Salmonella Enteritidis phagotype 04, observing possible histopathological and immunological alterations in the intestinal mucosa, like the length of the villus, the production of immunoglobulin A and body weight. Greater efficacy in the treatment with Lactobacillus ssp. was observed only when the chicks were challenged with Salmonella Enteritidis at 21 days old. The length of the intestinal villus always diminished after challenge, regenerating later. After the first challenge of with Salmonella Enteritidis (at three-days old), we verified that young chicks possess a greater sensibility to infection.<br>Mestre
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McCain, April Kathleen. "Influence of market setting and time of purchase on counts of aerobic bacteria, Escherichia coli, and coliform and prevalence of Salmonella and Listeria in beef, pork, and chicken in Vietnam." Thesis, Mississippi State University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1604197.
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<p> The objective of this study was to determine the influence of market type and sampling time on <i>Salmonella</i> and <i>Listeria </i> prevalence and microbiological quality of 540 beef, pork, and whole chicken samples collected in 6 supermarkets (SM), 6 indoor markets (IM), and 6 open markets (OM) at opening (T0) and 4 h after the opening (T4) in Vietnam. <i> Salmonella</i> and <i>Listeria</i> prevalence ranged from 30.4 to 71.0% and 56.6 to 99.9 %, respectively, in beef, pork, and chicken in Vietnam. Aerobic bacteria counts ranged from 10.5 to 11.6 log CFU/g, whereas, <i> E. coli</i> and coliform counts ranged from 7.2 to 11.4 log CFU/g in beef, pork, and chicken in Vietnam. <i>E. coli</i> counts were influenced by the interaction of market type and sampling time in beef and pork. Market characteristic data that were considered relevant to microbiological safety of fresh meat and poultry products were collected for individual samples. </p>
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Harper, Marina. "Virulence determinants of Pasteurella multocida." Monash University, Dept. of Microbiology, 2003. http://arrow.monash.edu.au/hdl/1959.1/9341.
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Pan, Deng. "An Integrated Study on Chicken Gut Microbiome Associated with Diets and Feed Utilization Using Microarray and Illumina Sequencing." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417694886.
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Eckhardt, Junior João Carlos. "Avaliação de desempenho de frangos de corte intoxicados com aflatoxinas e submetidos às concentrações de 0,25% e 0,5% de montmorilonita como adsorvente." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/99095.
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Aflatoxinas são metabólitos altamente tóxicos, com efeitos teratogênicos e carcinogênicos, produzidos predominantemente por fungos do gênero Aspergillus. Devido aos seus graves efeitos deletérios na produção animal, muitos estudos são conduzidos com o objetivo de encontrar métodos eficazes de minimizar seus prejuízos econômicos. O presente estudo teve como objetivo avaliar a eficiência do efeito protetor de um aditivo antimicotoxinas a base de bentonita cálcica natural brasileira (BCM – Brazilian calcium montmorillonite) sobre os parâmetros de ganho de peso, consumo e conversão alimentar, índice de eficiência produtiva, peso ponderado do coração, fígado, moela e baço, proteínas plasmáticas totais, e concentração de minerais no soro (cálcio, fósforo, magnésio, ferro, sódio, cloro e potássio). O experimento consistiu em 1056 pintos de corte machos, de 1 dia de vida, Cobb, distribuídos em baias aleatoriamente, com 22 aves em cada baia, por 42 dias. Foram utilizados 6 tratamentos, sendo o grupo controle sem o adsorvente BCM e sem aflatoxina (AFL), um grupo contendo apenas AFL (3 mg/kg), dois grupos recebendo apenas BCM (0,25% e 0,5%) e dois grupos recebendo AFL+BCM em dois níveis (0,25% e 0,5%). Os resultados demonstraram que de todo o experimento, o grupo mais afetado foi o das aves que receberam apenas AFL. Os tratamentos que receberam AFL+BCM a 0,25% e a 0,5% tiveram seus pesos 13,3% e 22,7% maiores do que o grupo que recebeu apenas AFL, respectivamente, e também aumentaram seu índice produtivo em 53% e 66,5%, respectivamente. Os índices de peso ponderado dos órgãos foram todos melhorados com a inclusão de BCM, mas houve um decréscimo no nível de potássio sérico de 15,3% quando comparado com o grupo que recebeu apenas AFL. A argila bentonita cálcica pode ser utilizada como aditivo adsorvente de micotoxinas para tratamento e controle de rações contaminadas com aflatoxinas em frangos de corte.<br>Aflatoxins are a highly toxic metabolites, with carcinogenic and teratogenic effects, produced mainly by the genus Aspergillus. Due their negative impact in the animal production chain, several studies have been conducted intended to find efficient methods to minimize the economical losses. The present experiment aimed to evaluate the protective effect of a Brazilian natural calcium montmorillonite (BCM) on the parameters of body weight gain, feed consumption, feed conversion, productive efficiency index, hart, spleen, liver and gizzard’s weight, total plasmatic protein level, and serum minerals. One thousand and fifty-six 1 d-old Cobb male broilers were housed in experimental pens (22 chickens per pen) for 42 d. Two levels of aflatoxins (AFLs) (0 and 3 mg kg-1) and three levels of BCM (0, 2.5 and 5 g kg-1) were assayed. Each treatment had eight replicates of 22 broiler chickens each. Of all the chickens tested in the experiment, the ones treated with AFLs were the most adversely affected. The treatments that received AFLs and BCM (0.25% and 0.5%) had their weights 13.3% and 22.7% heavier than the group that received only aflatoxins, respectively. They also improved their productive efficiency index in 53% and 66.5%, respectively. The organs weight parameter were all improved with the inclusion of BCM, but a decrease in the serium potassium level of 15.3% was observed when compared with the group that did not received AFLs. BCM did not affect negatively those groups that did not received AFLs. The BCM could be used as a mycotoxin binder for aflatoxins in broilers feed.
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Lautert, Claudia. "Efeitos de micotoxinas sobre o sistema imunológico de frangos de corte." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/116166.
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Aves domésticas são um dos principais alvos da contaminação alimentar com micotoxinas. O que contribui para o aumento dos prejuízos da indústria avícola devido a problemas como: alta mortalidade, redução do ganho de peso, alteração da conversão alimentar, imunossupressão, anormalidades embrionárias e morte embrionária precoce. Além disso, o acúmulo residual de micotoxinas na carne é uma preocupação da Saúde Pública. Diversos métodos são utilizados para a avaliação da citotoxicidade induzida por agentes tóxicos, incluindo a inibição do crescimento celular, a avaliação da capacidade celular de sintetizar macromoléculas necessárias para a replicação e da capacidade desse agente tóxico para induzir a peroxidação lipídica. Sendo assim, o objetivo geral do presente estudo foi avaliar os efeitos in vitro de ocratoxina A, deoxinivalenol e zearalenona sobre o sistema imunológico de frangos de corte, utilizando como parâmetros, a viabilidade celular, a atividade enzimática e o estresse oxidativo. Realizou-se cultivo primário de linfócitos das aves e o seu isolamento através da técnica de centrifugação por gradiente de densidade. Cada micotoxina foi adicionada ao meio celular, em uma confluência de 80%, em diferentes concentrações (0,001; 0,01; 0,1 e 1 μg/mL), analisando-se viabilidade celular, atividade de ecto-adenosina desaminase e acetilcolinesterase por ensaios colorimétricos e peroxidação lipídica através dos níveis de malondialdeído mensurados pela técnica de substâncias reativas ao ácido tiobarbitúrico. Todos esses parâmetros foram analisados em 24, 48 e 72 h, em triplicata e os resultados expressos como média e erro padrão da média, utilizando nível de significância P<0,05. Os resultados obtidos demonstraram que tanto ocratoxina A como deoxinivalenol induziram proliferação linfocitária e baixa atividade de adenosina desaminase, enquanto zearalenona também induziu proliferação, mas nenhuma alteração na atividade da respectiva enzima. Quanto à avaliação da peroxidação lipídica, demonstrou-se a seguinte relação crescente de citotoxicidade: deoxynivalenol> ocratoxina A> zearalenona; enquanto que na avaliação da atividade de acetilcolinesterase esta relação foi inversamente proporcional. Este é o primeiro estudo in vitro realizado com ocratoxina A, deoxinivalenol e zearalenona sobre o cultivo primário de linfócitos de frangos de corte na avaliação desses parâmetros.<br>Poultry is one of the main targets of food contamination with mycotoxins. This contributes to the increase in the poultry industry losses due to problems such as high mortality, reduced body weight gain, change in feed conversion, immunosuppression, embryonic abnormalities and early embryonic death. Furthermore, the residual accumulation of mycotoxins in the meat is a public health concern. Various methods are used to assess the cytotoxicity induced by toxic agents, including inhibition of cellular growth, the evaluation of cell ability to synthesize macromolecules necessary for replication and the ability of this toxic agent to induce lipid peroxidation. Thus, the general objective of this study was to evaluate the in vitro effects of ochratoxin A, deoxynivalenol and zearalenone on the immune system of broiler chickens using as parameters, cell viability, enzymatic activity and oxidative stress. It was realized a primary culture of lymphocytes of birds and their isolation through density gradient centrifugation technique. Each mycotoxin has been added to the cell medium, at 80% confluence, at different concentrations (0.001, 0.01, 0.1 and 1 μg/ mL), analyzing cell viability, ecto-adenosine deaminase and acetylcholinesterase activity by colorimetric assays and lipid peroxidation through the malondialdehyde levels measured by thiobarbituric acid-reactive species test. All these parameters were evaluated at 24, 48 and 72 h, in triplicate and the results expressed as mean and standard error of the mean, using P<0.05 as significance level. The results showed that both ochratoxin A and deoxynivalenol induced lymphocyte proliferation and low adenosine deaminase activity, while zearalenone also induced proliferation, but no change in their enzyme activity. The assessment of lipid peroxidation demonstrated the following increasing cytotoxicity relation: deoxynivalenol>ochratoxin A>zearalenone; while in the evaluation of acetylcholinesterase activity this relationship was inversely proportional. This is the first in vitro study performed with ochratoxin A, deoxynivalenol and zearalenone on the primary culture of broiler chicken lymphocytes evaluating these parameters.
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Wei, Shan. "Towards a Better Understanding of Poultry Intestinal Microbiome through Metagenomic and Microarray Studies." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1357219743.
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Lo, Miranda. "Characterisation of in vivo expressed proteins of Pasteurella multocida." Monash University, Dept. of Microbiology, 2003. http://arrow.monash.edu.au/hdl/1959.1/9429.
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Andrigheto, Cristiano. "Disseminação de Listeria monocytogenes em uma linha de produção de \"nuggets\" congelados de frango." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-25072017-152400/.
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A presente pesquisa teve por objetivo avaliar as fontes de contaminação por Listeria monocytogenes em uma linha de processamento de \"nuggets\" congelados de frango. Linhagens de L. monocytogenes isoladas de diferentes pontos de uma usina de processamento industrial nas diversas etapas do processamento foram avaliadas quanto à sua diversidade genética. A técnica empregada foi o RAPO com metodologia modificada da Organização Mundial da Saúde (OMS/WHO). Os perfis RAPO gerados com os \"primers\" M13 e UBC155 foram agrupados, combinados e analisados quanto à sua similaridade. As cepas foram também sorotipadas e 189 pertenciam ao sorogrupo 1 e 63 ao sorogrupo 4. A correlação entre a diversidade genética e a distribuição do microrganismo na linha de processamento foi estabelecida. As 252 L. monocytogenes estudadas puderam ser divididas em dois grandes \"clusters\" cada qual dividido em dois grupos. Os resultados da análise de \"clusters\" foram relacionados aos da sorologia, determinando sete subtipos. Verificou-se que três subtipos são introduzidos no ambiente de processamento juntamente com a matériaprima. Um deles foi encontrado somente na matéria-prima e os outros dois também foram detectados em superfícies de equipamentos e no ambiente de processamento. Outros subtipos encontrados em superfícies de equipamentos e no ambiente foram encontrados no produto em etapas subseqüentes. A contaminação da matéria-prima por cepas diferentes daquelas encontradas no ambiente de processamento mostra a sua importância como fonte de contaminação. Formas de controle da presença de L. monocytogenes na matéria-prima devem ser buscadas assim como o controle da contaminação ambiente.<br>This research was carried out in order to evaluate the sources of Listeria monocytogenes contamination in a frozen chicken nugget processing line. Strains of L. monocytogenes from different origins and isolated from different steps of the processing line were analysed for their genetic diversity. RAPO methodology modified from a WHO protocol was used. The RAPO profiles generated by primers UBC155 and M13 were grouped, combined and the similarities analysed. The strains were also serotyped and 189 belonged to serogroup 1 and 63 to serogroup 4. The correlation between genetic diversity and the strain distribution along the processing line was established. The 252 L. monocytogenes strains analysed were divided in two clusters, each of them containing 2 groups. Seven subtypes could be determined when the results of RAPO and serotyping were combined. It could be established that from the three sub-types of L. monocytogenes that belonged to the raw material, two could establish themselves in the processing line. These sub-types were detected latter in the environmental samples (food contact and non-food contact surfaces). On the other hand, other sub-types found initially in environmental samples were detected in the product in subsequent steps. The introduction of L. monocytogenes into the plant by raw material highlights its importance as a contamination source. Measures must be taken to control the presence of L. monocytogenes in the raw material as well as in the processing environment.
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Silva, Oyama Rodrigues da. "Modelo teórico de estimativa de risco de Salmonella Enteritidis em sistema integrado de produção de frango de corte e tipagem molecular de Salmonella spp. oriundas de aves e rações submetidas a diferentes tratamentos com ácido." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-28082008-160245/.
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O presente trabalho objetivou identificar os fatores de risco para a presença de S. Enteritidis no sistema de produção de frangos de corte, avaliar, qualificar e quantificar as variáveis encontradas e elaborar um modelo teórico de estimativa de risco deste sorovar em frangos criados em sistema de integração. Os dados foram obtidos de trabalhos recentes realizados por alguns autores e deram subsídios à realização de uma análise de riscos microbiológicos. Para caracterização molecular foram utilizadas 42 cepas de Salmonella isoladas de frangos e rações inoculados experimentalmente com uma cepa de S. Typhimurium. A inoculação da bactéria foi realizada na ração e a mesma tratada com diferentes concentrações dos ácidos propílico, fórmico e acético sendo, então, fornecida para consumo ad libitum até os 21 dias de idade, quando as aves foram sacrificadas. Foram obtidos diferentes perfis genéticos com o uso do ERIC e BOX-PCR, que se mostraram eficientes para discriminação das cepas em estudo.<br>The aim of this work was identify the risk factors for S. Enteritidis in the production system of broiler chickens, to evaluate, qualify and quantify the variables studied and to make a theoretical model of risk assessment of this serovar in broilers in integration system. Therefore, the data was obtain from works of some authors and supported the proposed model of microbiological risk analysis. For molecular characterization were included 42 Salmonella spp. strains isolated from chicks and feed experimentally inoculated with S. Tiphimurium. After inoculation of feed with the specific dose of strain, it was submitted to treatment with propilic, formic and acetic acids in several concentrations and it was given to birds ad libitum until 21 days old, when they were sacrificed. It was obtained different patterns through the ERIC and BOX-PCR techniques, which showed good discrimination power for the strains analyzed.
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Lopes, Graciela Volz. "Campylobacter spp. no abate e varejo: ocorrência em carcaças de bovinos para exportação e em cortes refrigerados de aves e bovinos." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-07122009-185602/.
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As infecções causadas por Campylobacter spp. são relatadas como causa freqüente de gastrenterites de origem alimentar em vários países do mundo. As espécies bacterianas termofílicas pertencentes ao gênero Campylobacter, principalmente Campylobacter jejuni e Campylobacter coli, têm sido isoladas de fezes de animais e estão associadas à contaminação da carne durante o processo de abate. Estas duas espécies são as mais freqüentemente envolvidas nos casos de campilobacteriose humana veiculada por alimentos. O presente estudo pretendeu avaliar a presença e a população de Campylobacter spp. no abate de bovinos e cortes refrigerados de aves e bovinos comercializados na cidade de São Paulo/SP. Um total de 198 animais foi amostrado no couro logo após a sangria, na carcaça imediatamente após a esfola e após a evisceração. As amostras foram obtidas através da técnica de swab na região do peito abrangendo uma área de 400 cm2. Foram analisados também 120 cortes refrigerados de frango e 100 cortes de carne bovina, assim distribuídos: 40 amostras de asa, 20 de coxa com sobrecoxa, 20 de coxa, 20 de coxinha da asa, 20 amostras de peito; 20 de patinho bovino (M. biceps femoris), 20 de contrafilé (M. longissimus dorsi), 20 de coxão mole (M. semi membranosus), 20 de lagarto (M. semitendinosus) e 20 de alcatra (M. glutaes medius). As amostras foram analisadas segundo os métodos ISO 10272-1 e 2 e os isolados obtidos foram confirmados como Campylobacter pela técnica de PCR. Campylobacter foi isolado em 22,7% (45/198) das amostras de couro bovino, ou seja, apenas no ponto antes da esfola, e C. jejuni foi a única espécie encontrada. Nas amostras de cortes de frango Campylobacter foi isolado em 14,2% (17/120) das amostras. A espécie prevalente em frangos foi C. coli (88%), seguido de C. jejuni (12%). Campylobacter spp. não foi isolado dos cortes bovinos. A população de Campylobacter spp. foi < 13 UFC/cm2 em carcaças bovinas, < 2 UFC/g em amostras de frango e < 10 UFC/cm2 em cortes bovinos. A susceptibilidade de 120 isolados de frango e couro bovino foi determinada frente a 8 agentes antimicrobianos usando o método de disco-difusão. A resistência às quinolonas (ác. nalidíxico e ciprofloxacina) foi frequentemente observada nas cepas de C. jejuni (72,2%) e C. coli (50,8%) isoladas dos frangos. Entre os isolados de C. jejuni obtidos do couro bovino maior taxa de resistência foi observada para estreptomicina (32%), seguida da eritromicina (16%) e do ácido nalidíxico (14%).<br>Campylobacter spp. infections are reported as a frequent cause of foodborne gastroenteritis in many countries. The thermophilic bacterial species belonging to the genus Campylobacter, particularly Campylobacter jejuni and Campylobacter coli have been isolated from feces of animals and are associated with the contamination of meat during the slaughtering process. These two species are the most frequently involved in cases of human campylobacteriosis conveyed by food. The aim of the present study was to evaluate the presence and population of Campylobacter spp. during cattle slaughter and in refrigerated chicken and beef cuts commercialized in the city of Sao Paulo/SP. A total of 198 animals were sampled in the hide after bleeding, the carcass immediately after skinning and after evisceration. Samples were obtained by swab technique in the chest area encompassing an area of 400 cm2. We also analyzed 120 refrigerated chicken cuts and 100 beef cuts. The samples were analyzed according to ISO 10272-1 and 2 methods and the isolates were confirmed as Campylobacter by PCR technique. Campylobacter was isolated only in the hide samples (45/198), and C. jejuni was the only species found. Campylobacter was isolated in 14.2% (17/120) of chicken samples. The most prevalent species in chickens was C. coli (88%), followed by C. jejuni (12%). Campylobacter spp. was not isolated from beef cuts. The counts of Campylobacter spp. was < 13 CFU/cm2 in bovine carcasses, < 2 CFU/g in chicken samples and < 10 CFU/cm2 in beef cuts. The susceptibility to 8 antimicrobial agents of 120 isolates of chicken and bovine hide was determined using the disk-diffusion method. The resistance to quinolones (ciprofloxacin and nalidixic acid) was frequently observed in strains of C. jejuni (72.2%) and C. coli (50.8%) isolated from chickens. Among strains of C. jejuni obtained from bovine hide highest resistance rate was observed to streptomycin (32%), followed by erythromycin (16%) and nalidixic acid (14%).
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Pascual, Camps Mònica. "Caracterització de Lactobacils d'origen intestinal i avaluació in vivo del seu poder probiòtic en pollastres." Doctoral thesis, Universitat de Girona, 2003. http://hdl.handle.net/10803/7627.
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Una soca de Lactobacillus salivarius resistent a la rifampicina, CTC2197, es va assajar com a probiòtic en pollastres, estudiant la seva capacitat de prevenir la colonització de Salmonella enteritidis C-114 en pollastres. Quan la soca probiòtica es va administrar via oral juntament amb S.enteritidis C-114 directament al proventricle en pollets Leghorn de 1 dia, el patògen fou eliminat completament després de 21 dies. Els mateixos resultats es van obtenir quan la soca es va administrar a través del menjar i l'aigua a més de la inoculació directa al proventricle. La inclusió de L.salivarius CTC2197 en el menjar del primer dia va mostrar que una concentració de 105 UFC g-1 era suficient per assegurar la colonització dels tracte gastrointestinal dels pollets després de 1 setmana. No obstant, entre els 21 i 28 dies, L.salivarius CTC2197 no va ser detectable en el tracte gastrointestinal d'alguns pollets, mostrant que seria necessària més d'una dosis per assegurar la seva presència fins al final de l'etapa d'engreix. La liofilització i la congelació per glicerol o llet descremada com a agents crioprotector, van semblar mètodes adequats per preservar la soca probiòtica. La inclusió de L.salivarius CTC2197 en un pinso comercial va semblar ser un bon mètode per subministrar-lo en granja, tot i que la soca va mostrar sensibilitat a les temperatures utilitzades durant l'emmagatzematge del pinso i a les incubadores dels pollets. A més, la supervivència va millorar després de diverses reinoculacions en pinso.<br>A rifampicin-resistant Lactobacillus salivarius strain, CTC2197, was assessed as a probiotic in poultry, by studying its ability to prevent Salmonella enteritidis C-114 colonization in chickens. When the probiotic strain was dosed by oral gavage together with S.enteritidis C-114 directly into the proventriculus in 1-day-old Leghorn chickens, the pathogen was completely removed from the birds after 21 days. The same results were obtained when the probiotic strain was also administered through the feed and the drinking water apart from direct inoculation into the proventriculus. The inclusion of L.salivarius CTC2197 in the first day chicken feed revealed that a concentration of 105 CFU g-1 was enough to ensure the colonization of the gastrointestinal tract of the birds after 1 week. However, between 21 and 28 days, L.salivarius CTC2197 was undetectable in the gastrointestinal tract of some birds, showing that more than one dose would be necessary to ensure its presence till the end of the rearing time. Freeze-drying and freezing with glycerol or skin milk as cryoprotective agents, appeared to be suitable methods to preserve the probiotic strain. The inclusion of the L.salivarius CTC2197in a commercial feed mixture seemed to be a good way to supply it on the farm, although the strain showed sensitivity to the temperatures used during the feed mixture storage and in the chicken incubator rooms. Moreover, survival has been improved after several reinoculations in chicken feed mixture.
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Vazquez, Ana M. "Possible Drivers in Endophyte Diversity and Transmission in the Tomato Plant Bacterial Microbiome." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1594918263597025.
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Dandachi, Iman. "Multi drug resistant organisms in Lebanese livestock." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0286/document.
Full textAbstract:
De nos jours, l'épidémiologie des bactéries multi-résistantes a évolué et ne se limite plus aux milieux hospitaliers. En effet, les animaux sont désormais considérés comme d’importants réservoirs de bactéries multi-résistantes, notamment des Bacilles à Gram négatif sécréteurs de bêta-lactamases et/ou résistant à la colistine. L'émergence de ces bactéries chez les animaux est due principalement à l’utilisation excessive d’antibiotiques en tant que prophylaxie et facteurs de croissance. Le transfert d’organismes multi-résistants aux antibiotiques provenant d’animaux vers les humains est un problème majeur pouvant entrainer de graves infections. La transmission zoonotique se fait par contact direct/indirect mais aussi par voie environnementale. Au Liban, plusieurs études ont été menées dans les hôpitaux et ont montré une prévalence élevée de bactéries multi-résistantes. En revanche, ces études sont rares dans le milieu vétérinaire. Le but de ce travail de thèse est de décrire l'épidémiologie des organismes multi-résistants dans les animaux d’élevage destinés à la consommation au Liban. Le typage des bactéries par MLST et le séquençage du génome entier ont été utilisés pour décrire la prévalence des organismes multi-résistants et les mécanismes de résistance chez les souches isolées. Nous pouvons ainsi conclure que les élevages de poulets et de porcs sont de puissants réservoirs de gènes de résistance BLSE et mcr-1 au Liban. La dissémination de la résistance semble être polyclonale et liée à la propagation de plasmides porteurs de gènes de résistance. Par conséquent, l'utilisation de la colistine en médecine vétérinaire au Liban doit être interdite<br>Nowadays, the epidemiology of multi-drug resistance has changed and is no more confined to the hospital settings. Food producing animals are increasingly regarded as potent reservoirs of multi-drug resistant organisms i.e. beta lactamase producers and colistin-resistant Gram-negative bacilli. The emergence of multi-drug resistance in animals is thought to be mainly driven by the overuse of antibiotics as growth promoters and prophylaxis. The dissemination of resistant organisms in animals is sparked by the concern of being transferred to humans where they can be candidates for infections with limited therapeutic options. The zoonotic transmission of resistant organisms from animals to humans occurs mainly via direct/indirect contact but also via environmental routes. In Lebanon, several studies were conducted in hospitals and showed a high prevalence of multi-drug resistance; unlikely, these studies are scarce in animals. The aim of this thesis research was thus to describe the epidemiology of multi-drug resistant organisms in Lebanese Livestock Multi-locus sequence typing and whole genome sequencing were used to describe the prevalence of multi-drug resistant organisms and the corresponding mechanisms of resistance in the isolated strains from chicken, pigs, farmers and environment. Chicken and swine farms showed to be potent reservoirs of ESBL and mcr-1 genes in Lebanon. The dissemination of multi-drug resistance appears to be multi-clonal and related to the spread of plasmid carrying resistance genes. Colistin use in veterinary medicine in Lebanon should be banned
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"A Plant Based Vaccine for Necrotic Enteritis in Chickens." Master's thesis, 2018. http://hdl.handle.net/2286/R.I.50573.
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abstract: Necrotic enteritis (NE) is caused by type A strains of the bacterium Clostridium perfringens, leading to an estimated 2 billion dollar global economic loss in the poultry industry annually. Traditionally, NE has been effectively controlled by antibiotics added to the diet of poultry. Concerns about increasing antibiotic resistance of poultry and human based pathogens have led to the consideration of alternative approaches for controlling disease, such as vaccination. NE causing strains of C. perfringens produce two major toxins, α-toxin and NetB. Immune responses against either toxin can provide partial protection against NE. We have developed a fusion protein combining a non-toxic carboxy-terminal domain of the α-toxin (PlcC) and an attenuated, mutant form of NetB (NetB-W262A) for use as a vaccine antigen to immunize poultry against NE. We utilized a DNA sequence that was codon-optimized for Nicotiana benthamiana to enable high levels of expression. The 6-His tagged PlcC-NetB fusion protein was synthesized in N. benthamiana using a geminiviral replicon transient expression system. The fusion protein was purified by metal affinity chromatography and used to immunize broiler birds. Immunized birds produced a strong serum IgY response against both the plant produced PlcC-NetB protein and against bacterially produced His-PlcC and His-NetB. However, the PlcC-NetB fusion had antibody titers four times that of the bacterially produced toxoids alone. Immunized birds were significantly protected against a subsequent in-feed challenge with virulent C. perfringens when treated with the fusion protein. These results indicate that a plant-produced PlcC-NetB is a promising vaccine candidate for controlling NE in poultry.<br>Dissertation/Thesis<br>Masters Thesis Molecular and Cellular Biology 2018
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Chen, Yinghwei. "Quality of fryers purchased in retail markets using microbial and sensory assessment." Thesis, 1989. http://hdl.handle.net/1957/27280.
Full textAbstract:
Dressed, bagged whole chickens from three Oregon and several
out-of-state processors were purchased from retail markets in each
season in 1988. Birds were stored at 3°C for 6 days. Total aerobic
microorganisms, total psychrotrophic microorganisms, pseudomonads
and fluorescent pseudomonads were determined by appropriate
procedures. Total aerobic microorganisms and psychrotrophic
microorganisms were counted on standard plate count agar with
incubation at 20°C for 3 days and at 5°C for 7 days, respectively. Two
media, King's B medium and CFC medium, were used in counting
pseudomonads. Fluorescent colonies were observed on King's medium
under ultraviolet light. A simple slime smear test was used to
determine the sliminess.
Sensory evaluation was done by thirteen panelists using 9-point
scales. The flavor of cooked white and dark meat and skin, the flavor intensity of cooked white and dark meat and skin, the aroma of raw and
simmered meat, the aroma intensity of raw and simmered meat and
raw sliminess were evaluated.
Simple regression analysis was used to determine the
relationships between the microbial parameters and sensory
evaluations. The paired t test was used in determining the difference
between counts on King's medium and CFC medium. A significance
level of 95% was set for all tests. Correlation coefficients were also
calculated.
All the microbial counts were at or below 10⁷/cm², which
indicated from literature comparisons that most of the fryers purchased
from retail markets and stored for six days were of acceptable quality.
The season had no significant effect on the microbial counts and sensory
qualities. The means of flavor of cooked meat and skin and aroma of
raw and simmered meat were all above fair. Only the raw aroma
intensity was significantly (p<0.05) and strongly correlated (r=-0.88) to
the aroma quality. Relationships between microbial counts and flavor of
cooked meat and aroma of raw and simmered meat were all significant
but the correlations were weak. The narrow range of microbial counts
may explain the weakness of the correlations found. The slime smear
tests had a positive relationship (p<0.05) to the raw sliminess score by
panelists, total aerobic microorganisms, total psychrotrophic
microorganisms, pseudomonads, and fluorescent pseudomonads.<br>Graduation date: 1990
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Jacobs, Amanda. "The influence of effective microorganisms (EM) on the growth, production and egg quality of the commercial laying hen." Diss., 2001. http://hdl.handle.net/2263/26085.
Full textAbstract:
In the first part of the study an experimental design was followed whereby 600 DeKalb Amber-link® commercial laying pullets were subjected to three levels of EM bokashi (0.5%, 1.0% and 1.5%) and a standard level of a coccidiostat in the starter (17% CP, 0.9% Ca and 0.4% available phosphate) and grower (15% CP, 0.8% Ca and 0.35% available phosphate) diets from day-old to 16 weeks of age. EM treatments did not significantly affect the average weekly body mass, average daily gain, average weekly feed intake, cumulative weekly feed intake, cumulative feed conversion ratio and the average bi-weekly shank length over the control. The coccidiostat treatment maintained significant lower body weights, average daily gains and worse feed conversion ratios than all the EM treatments and the control throughout the trial period of 16 weeks. Although not significant the EM 1.5% level had the best feed conversion ratio, the highest body mass and the longest shank length at the end of the trial period at week 16. Mortalities were not treatment linked.<br>Dissertation (MSc Agric (Nutritional Science))--University of Pretoria, 2006.<br>Animal and Wildlife Sciences<br>unrestricted
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Vaziry, Asaad. "Chicken infectious anemia virus vaccination induces immune disorders and viral persistency in infectious bursal disease virus-infected young chicks." Thèse, 2010. http://hdl.handle.net/1866/5101.
Full textAbstract:
La bursite infectieuse aviaire (IBD) est une des causes majeures de pertes économiques pour l’industrie aviaire. La vaccination est le principal outil de contrôle de cette maladie et les oiseaux susceptibles doivent être vaccinés aussitôt que le niveau des anticorps maternels (MA) anti-IBDV est suffisamment bas. L’estimation du moment de vaccination est habituellement déterminée par la formule de Deventer qui utilise le titre initial de MA anti-IBDV et la demi-vie des anticorps pour prédire l’évolution du titre. Dans la présente étude, l’effet du gain de poids sur la vitesse de disparition des MA a été étudié dans le but de l’utiliser pour prédire la détermination du moment de la vaccination. L’analyse des taux d’anticorps neutralisants par ELISA a montré que les poussins avec une forte croissance avaient un taux de disparition plus rapide des MA que ceux à faible croissance. Une formule pour la prédiction du moment de vaccination contre le IBDV, basée sur le gain de poids et le niveau des MA a été développée et vérifiée. La prédiction du moment de vaccination avec cette formule a montré une haute corrélation avec les titres de MA mesurés par ELISA.
Le virus de l’anémie infectieuse aviaire (CIAV) est une cause importante d’immunosuppression chez le poulet augmentant la pathogénicité des infections secondaires et en entraînant une réponse humorale suboptimale et une forte mortalité. D’autre part, l’infections sub-clinique du au CIAV provoque une immunosuppression qui facilite la coinfection par d’autre virus tel que le IBDV. Les effets de la coinfection à J1 avec une souche vaccinale de CIAV CAV-VAC® (Intervet) et à J14 avec une souche faiblement virulente de IBDV isolée au Québec, sur l’état de santé des poussins, sur la persistance virale et sur la réponse immunitaire ont été étudiés autant chez des poussins de 1 jour d’âge exempts d’agents pathogènes specifique (SPF) que ceux provenant d’élevages commerciaux. Les résultats ont montré que l’inoculation de la souche vaccinale du CIAV a entraîné une infection sub-clinique, une persistance virale dans la rate et le thymus, une altération de la thymopoièse et une réponse humorale temporaire chez les poussins SPF. Ces effets ont aussi été mis en évidence chez des poussins d’élevage commerciaux malgré des taux élevés de MA. Lors de l’infection avec la souche de IBDV chez des poussins déjà vaccinés contre le CIAV, la persistance du CIAV dans les organes lymphoïdes a été aggravée par une présence de réponses humorales temporaires contre les deux virus et une altération des populations lymphocytaires dans les organes lymphoïdes. Par contre, la présence des MA contre le CIAV a limité temporairement ces effets. Ces travaux ont mis en évidence des désordres immunitaires cellulaires et humoraux et une persistance virale chez des poussins vaccinés contre le CIAV et co-infectés avec le IBDV.<br>Infectious bursal disease (IBD) is one of the major causes of economic losses in the chicken industry. Vaccination is the main tool against the disease, and the susceptible birds should be vaccinated as soon as the maternal antibody (MA) becomes low enough to allow the vaccine to break through. Estimation of vaccination time is currently performed by Deventer formula which uses initial anti-IBDV titer and antibody half-life to predict the titer. Considering the increased growth rate of chicken in the last decades and the wide variations of MA, we have examined the effects of chick’s weight gain on MA decline and the use of weight in predicting IBD vaccination time. The virus neutralization test and ELISA results demonstrated that fast-growing birds had a faster rate of antibody decline whereas slow-growing birds demonstrated a slower rate. Based on the effect of weight-gain on maternal antibody decline, a new formula for predicting IBD vaccination time was introduced and tested. The predicted IBD vaccination time made by this weight formula showed higher correlation with the measured ELISA titers in the experiment.
Chicken infectious anemia virus (CIAV) is another cause of immunosuppression in chicken which is characterized by increased pathogenicity of secondary infectious agents, sub-optimal antibody responses and mortality. CIAV subclinical infections can result in immunosuppression and enhancement of pathogenicity of co-infecting agents such as infectious bursal disease virus (IBDV). Effects of pathogenic CIAV and IBDV coinfection on chick’s health and immune responses are investigated in different studies. In this study, newly hatched specific pathogen free (SPF) and commercial chicks were vaccinated with CAV-VAC® (Intervet) vaccine and /or inoculated with a low-virulent Québec isolate of IBDV at 14 days post CIAV vaccination.
Inoculation of the CIAV vaccinal strain at hatch resulted in subclinical infection associated with viral persistency in spleen and thymus, alteration of thymopoiesis and transient humoral response in SPF chicks. Subclinical infection, viral persistency and lack of antibody responses were also shown in CIAV inoculated commercial chicks with high MA. Infection of the low-virulent IBDV in the CIAV vaccinated SPF chicks lead to extended viral persistence of CIAV in lymphoid organs, transient immune responses to both CIAV and IBDV, and alteration of lymphocytes subpopulation in the lymphoid organs. In the coinfected commercial chicks, presence the CIAV in the lymphoid organs was controlled by MA in the first 1-2 weeks after hatch. Thereafter, the immune disorders, viral persistence and lack of humoral responses almost similar to the coinfected SPF chicks were recorded.
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Kaboré, Kiswendsida Paul. "Étude de prévalence et associations des gènes de virulence et résistance aux antimicrobiens d’Escherichia coli de la flore intestinale du poulet sain." Thèse, 2011. http://hdl.handle.net/1866/6277.
Full textAbstract:
Les Escherichia coli pathogènes de la volaille (APEC) font partie des E. coli extra-intestinaux pathogènes (ExPEC) et seraient un réservoir possible de gènes de virulence et de résistance aux antimicrobiens (RAM) des ExPEC chez l’humain. L’objectif de cette étude était d’évaluer l’effet d’un prébiotique et d’un mélange d’acide organique et d’huiles essentielles encapsulés sur la prévalence des gènes de virulence des ExPEC et de RAM, ainsi que les associations entre ces gènes chez E. coli de l’intestin du poulet sain. Des échantillons de contenus caecaux de poulets de 29 jours d’âge ayant reçu un de ces ingrédients alimentaires comparativement à des témoins ont été analysés pour la présence des gènes de virulence iucD, tsh, papC et des gènes de RAM blaTEM, blaSHV, tetA, tetC, blaCMY-2, aadA1, aac3 par PCR. La prévalence d’iucD était supérieure dans le groupe témoin comparativement aux groupes «prébiotique» et «acide organique» et la prévalence de papC était affectée dans le groupe «acide organique». La prévalence d’isolats d’E.coli positifs pour blaCMY-2 était supérieure dans le groupe témoin comparée aux groupes «prébiotique» et «acide organique», tel que démontré par la technique d’hybridation de l’ADN sur HGMF (Hydrophobic Grid Membrane Filter). De plus, la prévalence des isolats d’E. coli positifs pour tetA, blaTEM, aadA1 ou tsh était affectée par les ingrédients alimentaires. Dans l’ensemble, des associations entre la présence de tsh et iucD, blaTEM et aadA1, et iucD et blaCMY-2 ont été observées. .Cette étude démontre l’utilité de certains ingrédients alimentaires pour dimunier le risque d’exposition en santé publique.<br>Avian Pathogenic E. coli (APEC) belong to the extra-intestinal pathogenic E. coli (ExPEC) pathotype, and may be a virulence and antimicrobial resistance (AMR) gene reservoir for ExPEC in humans. The aim of this study was to evaluate the effect of addition to the feed of a prebiotic or an organic acid on the prevalence of ExPEC-associated virulence genes and antimicrobial resistance (AMR) genes and the association between these genes in E. coli of the intestinal microflora of healthy chickens. Caecal contents from 29-day-old chickens having received one of these feed ingredients in comparison to a control group were examined for the presence of virulence genes iucD, tsh, and papC and AMR genes blaTEM, blaSHV, tetA, tetC, blaCMY-2, aadA1, and aac3 by PCR. The prevalence of iucD was significantly higher in the control group than in the prebiotic and organic acid groups and prevalence of papC was affected by the use of the organic acid. The prevalence of blaCMY-2-positive E. coli isolates was higher in the control group than the prebiotic or organic acid groups, as demonstrated by Hydrophobic–grid membrane filter (HGMF) DNA probe colony hybridization. In addition, the prevalence of E. coli isolates positive for tetA, blaTEM, aadA1 or tsh was affected by the use of these feed ingredients. Overall, associations between the presence of iucD and tsh, blaTEM and aadA1, and iucD and blaCMY-2 were observed. This study demonstrates that the use of certain feed ingredients could reduce the risk of exposure in a public health perspective.
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Zhou, Wei. "Functional Cloning and Characterization of Antibiotic Resistance Genes from the Chicken Gut Microflora." 2011. http://trace.tennessee.edu/utk_gradthes/930.
Full textAbstract:
A recent study using human fecal samples in conjunction with a culture-independent approach revealed immense diversity of antibiotic resistance (AR) genes in the human gut microflora. We hypothesize that food animal gut microflora also contain diverse and novel AR genes which could contribute to the emergence and transmission of AR in pathogens important in animal and human health. To test this, we examined AR reservoir in chicken gut microflora using a metagenomic, functional cloning method. Total genomic DNA was extracted from individual cecal contents of two free range chickens and two conventionally raised chickens. The DNAs were physically sheered into 1 to 3 kb fragments, cloned into expression vector pZE21-MCS, and transformed into E. coli TOP10 host strain, resulting in four metagenomic libraries of a total size of 108 base pairs per library. The AR transformants from the libraries were selected on plates containing the specific antibiotic of interest; six antibiotics including ampicillin, tetracycline, chloramphenicol, spectinomycin, ciprofloxacin and norfloxacin were used for screening. Plasmids from selected transformants were extracted and subjected to sequence analysis of inserted fragments. Identified AR genes were annotated and aligned with homologs that have been deposited in GenBank. A total of 12 AR genes and 3 AR genes were identified from the microbiome in conventionally raised chickens and free-range chickens, respectively. Of the identified 15 AR genes, 8 genes that confer resistance to ampicillin, spectinomycin or chloramphenicol shared low sequence similarity (58% - 76% at amino acid level) with the corresponding AR genes previously identified using culture-dependent approaches. Notably, among the 8 novel AR genes identified in this study, 4 genes also shared low sequence similarities (59%-76% at amino acid level) with recently identified AR genes in human gut. An E. coli-Campylobacter shuttle vector bearing the flaA sigma 28 promoter was constructed. Two novel genes conferring resistance to ampicillin (FRAmp1.1) and spectinomycin (FRSpe1.1) were cloned into this new expression vector, respectively. The derived vectors have conferred increased AR in C. jejuni, a leading zoonotic bacterial pathogen causing human gastroenteritidis in many industrialized countries. Together, findings from this study showed the effectiveness of the metagenomic approach for examination of AR reservoir in food animals, revealed novel AR resistance genes in chicken gut microflora, and demonstrated the functionality of such AR genes in foodborne human pathogens.