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1
Westling, Katarina. "Viridans group streptococci septicaemia and endocarditis : molecular diagnostics, antibiotic susceptibility and clinical aspects /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-364-7/.
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Unnikrishnan, Meera. "Streptococcal superantigens in Group A streptococcal infections." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248185.
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Flock, Margareta. "Development of a vaccine against strangles /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-500-3/.
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Smith, Jennifer Marie. "Characterization of host-bacteria interactions contributing to group B streptococcus colonization." Huntington, WV : [Marshall University Libraries], 2002. http://www.marshall.edu/etd/descript.asp?ref=64.
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Wright, Lynda J. "Identification and characterisation of components expressed by gram-positive bacterial pathogens during human infection." Thesis, University of Sheffield, 2008. http://etheses.whiterose.ac.uk/10312/.
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Gram-positive pathogens are responsible for a wide range of global diseases, including nosocomial infections. The increasing incidence of antibiotic-resistant strains warrants the development of novel therapeutic strategies to combat these organisms.
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Ihendyane, Nahla. "Pathogenesis and immunotherapy of streptococcal septicemia and shock /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-599-9/.
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Darenberg, Jessica. "Streptococcus pyogenes infections and toxic shock syndrome : molecular epidemiology and immunotherapy /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-676-X/.
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Leung, Chin-pang, and 梁展鵬. "Characterization of group a streptococcus in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B3196963X.
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Stofile, P. Z. "Prevalence of Group B streptococcus and staphylococcus aureus colonization in the anogenital tract of pregnant women in the Eastern Cape Province, South Africa." Thesis, University of Fort Hare, 2017. http://hdl.handle.net/10353/5983.
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Neonatal sickness and death is increasingly becoming a public health problem worldwide. The colonization of Group B Streptococcus and Staphylococcus in the rectovaginal area is among the sources of infections in neonates which can result in illness and mortality. The over exposure of humans to antibiotics is the possible cause of resistance in bacteria. These resistant strains can be passed onto offspring, leading to resistant infections and increasing the morbidity of neonates because of treatment failures. Many people, including healthcare personnel are not aware of the effect of these bacteria, and informing clinics and hospitals can help create awareness and monitoring the levels of resistance among bacteria can assist in preventing the transference of the bacteria. In this study we investigated the prevalence of group B Streptococcus (GBS) and Staphylococcus aureus in the anogenital tract of pregnant women in the Eastern Cape Province, South Africa. A total of 49 isolates from 25 (30.5 percent) pregnant women colonized with GBS were isolated from vaginal and rectal swabs of 82 pregnant women at 25-37 gestation who participated in this study. These isolates were obtained using standard microbiological methods and confirmed by polymerase chain reaction (PCR) technique aimed at the ScpB gene. The isolates were further screened for the presence of 9 serogroups (Ia, Ib, II, III, IV, V, VI, VII, VII) and serogroups Ib 2 (4.8 percent), II 20 (40.8 percent) and IV 5 (10.2 percent) and 22 non-typable (44.9 percent) were identified. Susceptibility profiling of the isolates to 12 antibiotics (tetracycline, clindamycin, erythromycin, gentamycin, naladixic acid, norfloxacin, chloramphenicol, cefuroxime, cefotaxime, imipenem, penicillin and vancomycin) was tested in vitro by the standardized disc diffusion method. All the confirmed GBS isolates (49) were resistant to erythromycin, tetracycline and clindamycin. A higher percentage of the isolates were resistant to gentamycin 44 (90 percent), nalidixic acid 41 (84 percent), penicillin 41 (84 percent), chloramphenicol 38 (78 percent), cefuroxime 36 (74 percent), imipenem 36 (74 percent), cefotaxime 35 (71 percent), norfloxacin 32 (65 percent) and vancomycin 31 (78 percent). Multiple antimicrobial resistance patterns ranged from 9‒11 and indices ranged from 0.7‒0.9, respectively. Among the antimicrobial resistance determinants examined, genes encoding for resistance to erythromycin ermB 25 (51 percent), tetracycline tetM 32 (65 percent) and penicillin bla-Z 4 (8 percent) only were identified. On the other hand, screening for S. aureus yielded a total of 7 isolates from 4 study participants as confirmed by PCR based on staphylococcal, nuc gene. The isolates were further screened for the presence of six virulence genes (Hla, Hlb, LUKM, LUKED, PVL, Eta and Etb) and antibiotic susceptibility pattern by the disc diffusion method using 12 (penicillin, vancomycin, tetracycline, rifampicin, imipenem, gentamycin, chloramphenicol, norfloxacin, oxacillin, erythromycin and sulfamethoxazole-trimethoprim) antibiotics that are adopted in the treatment of infections caused by the organism. PVL 6 (85.7 percent) and eta 1 (14.3 percent) were the two virulence genes detected. The following percentages of antibiotics resistance among the isolates were observed; penicillin G 7 (100 percent), clindamycin 7 (100 percent), vancomycin 5 (100 percent), rifampicin 5 (71 percent), oxacillin 5 (71 percent), erythromycin 5 (71 percent) gentamycin 3 (43 percent), norfloxacin 3 (43 percent), sulfamethoxazole-trimethoprim 3 (43 percent), chloramphenicol 2 (29 percent), imipenem 1 (14 percent). Multiple antimicrobial resistance patterns ranged from 7‒8 and indices ranged from 0.6‒0.7, respectively. Genetic profiling of the resistance genes identified erythromycin ermB 5(71.4 percent), tetracycline tetM 5(71.4 percent) and penicillin bla-Z 1(14.3 percent) only. The findings from the study have revealed GBS and S. aureus colonization of pregnant women in the Eastern Cape Province, and these have great public health implications especially for the neonates who are mostly likely to be infected during birth. The unidentifiable multidrug resistant serogroups of GBS as well as resistant S. aureus limit the choice of drugs in the management of infections caused by these pathogens more so if transmitted to infants. Therefore asymptomatic pregnant women needed to be properly educated about the bacteria as well as the precautions that need to be taken.
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Eriksson, Björn K. G. "Invasive group A streptococcal infection : host and pathogen interactions /." Stockholm, 1999. http://diss.kib.ki.se/1999/91-628-3609-9/.
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Crowley, Ian F. "Intranasal Vaccination to Boost Equine Immunity to Uterine Streptococcal Infection." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/CrowleyIF2007.pdf.
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Rox, Katharina [Verfasser], and Rolf [Akademischer Betreuer] Müller. "Natural compounds as pathoblockers of streptococcal infections / Katharina Rox ; Betreuer: Rolf Müller." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2015. http://d-nb.info/1165573938/34.
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Fashola, Bola. "The Effect of Sodium Chloride on Beta-Hemolytic Streptococci." TopSCHOLAR®, 1987. https://digitalcommons.wku.edu/theses/2321.
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The drug of choice for the treatment of Stieptococcal pharyngitis is penicillin G. However, a common home remedy prescribes the use of salt-water solutions for gargling.
Members of Beta -hemolytic streptococcal groups A, B, and C were isolated from the upper -respiratory tracts of patients diagnosed as having streptococcal pharyngitis. These cultures we:e obtained from HCA Greenview Hospital (Bowling Green, Kentucky) and used to study the effects of sodium chloride on the isolates.
The minimum inhibitory concentration of sodium chloride was determined for each of eight hospital isolates. Croup A streptococci were inhibited at a concentration of 7.2% sodium chloride while Group C streptococci were inhibited at a 7.0% concentration. Group P streptococci were more resistant, and inhibition of growth occurred at 12.0% sodium chloride concentrations.
Scanning electron microscopic studies showed no significant differences in the external structure of cells treated with sodium chloride when compared to non-treated cells. Despite the lack of changes in the external structure of treated cells, fine structural alterations were observed with transmission electron microscopic studies.
Treatment of the cells with sodium chloride resulted in a condensation of nucleoid deoxyribonucleic acid (DNA) and some loss of ribosomes. These changes were followed by a dissolution of the cytoplasmic cell contents resulting in an intact cell wall with capsule.
Other parameters such as the rate of growth, minimum bactericidal concentrations, DNA content and protein content of cells treated with sodium chloride were examined and compared to control cells.
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McKay, Fiona Catherine. "Is plasminogen deployed as a virulence factor by Northern Territory group A streptococcal isolates during invasive disease?" Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20060712.140148/index.html.
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Nooh, Mohammed Mostafa. "Biochemical and immunological mechanisms underlying differential interaction of superantigens with host immunogenetic factors in streptococcal sepsis." View the abstract Download the full-text PDF version, 2008. http://etd.utmem.edu/ABSTRACTS/2008-027-Nooh-index.html.
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Thesis (Ph.D )--University of Tennessee Health Science Center, 2008.Title from title page screen (viewed on Sept. 17 2008). Research advisor: Malak Y. Kotb, Ph.D. Document formatted into pages (xvii, 189 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 161-189).
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Garcia, Febres Julio Carib. "A comparative investigation of Streptococcus agalactiae isolates from fish and cattle." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Spring%20Dissertations/GARCIA_JULIO_46.pdf.
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Law, Vicky Wai-Kee. "Oral colonization of mutans streptococci in young children : a longitudinal study /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19176.pdf.
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Pires, Renato Hélder Morais. "Evolution of genotypes of Group A streptococci from colonization and infection." Doctoral thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/6917.
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Dissertação para obtenção do Grau de Doutor em BiologiaStreptococcus pyogenes is one pathogenic bacterium of humans and is associated with a wide variety of infections and disease states, ranging from uncomplicated but highly prevalent pharyngitis to extremely severe infections, such as necrotizing fasciitis and streptococcal toxic shock syndrome. This work aimed to study important and unexplored aspects of the epidemiology, transmission and evolution of S. pyogenes causing colonization and a wide range of diseases. Our sample included 1,629 nonduplicated S. pyogenes isolates associated with colonization and infections. Out of the 1,629 isolates, 1,026 were recovered from 10,578 throat swabs of asymptomatic populations (children and adults) during 2000-2007 and 603 isolates were from patients diagnosed with clinical infections: 487 with tonsillitis/pharyngitis in 2000-2006, 72 with skin/soft tissue infections in 1999-2005, and 44 with invasive diseases in 1999-2005. This study demonstrated that a very heterogeneous population of S. pyogenes colonized healthy carriers. The mean carrier rate was higher among pre-school children (0-6 years) than among school-aged children (7-16 years) and colonization frequency was higher during Winter periods, which suggests that the crowding of children in day-care centers may possibly increase the carrier rate in healthy pre-school children. Moreover, it was also found that a high diversity of S. pyogenes strains was associated with long-term colonization, and it was detected co-colonization of the oropharynx by multiple S. pyogenes strains. In this work, it was reported the long term persistence among carriers of the low-level bacitracin-resistant emm28/ST52 lineage, which is prevalent in Europe. It was also reported for the first time a high-level bacitracin-resistant isolate of the emm74/ST120 lineage, which was not previously known to include bacitracin-resistant isolates. In this study were also reported for the first time temporal inversions of macrolide resistance phenotypes among colonization isolates, reinforcing the importance of surveillance of carriers, as they may be indicators of the pool of isolates circulating in the community that may cause infections. The high prevalence (>20%) of virulence genes speC, prtF1 and ssa was probably caused either by clonal dissemination (speC), or to horizontal gene transfer events (prtF1 and ssa). In this work it was observed that ciprofloxacin-nonsusceptibility rate was slightly lower among colonization isolates (4.3%) than among the clinical isolates (6.0%). All but one ciprofloxacin-nonsusceptible isolates had parC-QRDR mutations generating the aminoacid substitutions S79A (n=63) and D83G (n=2); the ParC-D83G substitution was found for the first time in this study and emm1 association with fluoroquinolone-nonsusceptibility was also first detected in this work. It was observed a higher frequency of virulence genes among isolates from disease, such as tonsillitis/pharyngitis, skin/soft tissue infections or invasive disease, than among colonization. In particular, this study contributed to a better knowledge of S. pyogenes virulence factors that circulate in this country. Among the 1,629 isolates, novel genotypes were discovered, such as emm-subtypes 6.63, 28.9, 53.10, st4040.0 and stMrp6.0, as well as sequence types ST380, ST397, ST398, ST401, ST402, ST427, ST428, ST429, ST430, ST431 and ST581. In conclusion, the results from this dissertation extend our knowledge about the carrier state, the susceptibility to antimicrobial agents, molecular epidemiology and virulence of S. pyogenes isolates from oropharyngeal colonization and symptomatic infections.
Fundação para a Ciência e a Tecnologia (FCT)- (SFRH/BD/32374/2006)
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Effertz, Bernard Stephen. "The humoral immune response to streptococcal cell wall-induced arthritis in the rat." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184877.
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I investigated the humoral immune response to streptococcal cell walls (SCW) in arthritis susceptible Lewis and resistant Fisher rats. All rats were given a single intraperitoneal injection of either SCW or saline (controls). Rats were sacrificed, three rats per time point, over an eleven week period and serum was collected for ELISA. SCW injected Lewis rats produced anti-SCW antibody, whereas control rats did not. Anti-SCW antibody was significantly elevated over controls between days 14-28 (post injection). Both saline and SCW injected Fisher rats produced anti-SCW antibody, but with different kinetics. Anti-SCW antibody increased by day 7 and remained elevated over controls till day 21, after which there was no difference. ELISA were designed to determine the SCW epitope(s) recognized by anti-SCW antibody. Formamide extracts of SCW, peptidoglycan and polysaccharide, were investigated along with the terminal epitope of polysaccharide, N-acetyl-D-glucosamine, and the peptidoglycan precursor peptide. The data revealed that anti-SCW antibody was directed against a combined SCW epitope, given the lack of significant binding to any of the SCW epitopes tested. Isotype analysis of anti-SCW antibody revealed that the Lewis response was composed primarily of IgG2a whereas the Fisher response was composed primarily of IgM. Binding of rat IgG isotypes to whole streptococcus, SCW, peptidoglycan, and polysaccharide was investigated, given the possibility of background binding by the streptococcal Fc-receptor. Streptococcal binding of rat IgG was specific for IgG2c and the polysaccharide portion of SCW was necessary for binding. Passive immunization of naive Lewis rats with antibody from rats with active arthritis was ineffective at transferring the disease. However, subcutaneous injection of affinity purified anti-SCW antibody or IgG into Lewis rats, followed twenty-four hours later by a single intraperitoneal injection of SCW, suppressed the acute phase and inhibited the chronic disease. IgM rheumatoid factor (RF) was present in the serum of both saline and SCW injected Lewis and Fisher rats. However, SCW injection only induced a significant increase in IgM RF (between days 3-7) in Lewis rats. Passive immunization of Fisher rats with affinity purified IgM RF (from Lewis serum), three days post SCW injection, was ineffective at inducing arthritis.
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Barth, Dylan Dominic. "AFROStrep (SA): a surveillance system for group A streptococcal infection in South Africa." Doctoral thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29316.
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BACKGROUND AND AIMS OF THE THESIS: Group A β-haemolytic Streptococcus (GAS) also known as Streptococcus pyogenes, is responsible for a wide range of invasive and non-invasive GAS diseases. Prevalence and incidence data on GAS from developing countries are largely lacking when compared with industrialised nations. This thesis sought to (1) establish the South African arm of the AFROStrep biorepository and clinical database for patients with invasive and non-invasive GAS infection, (2) identify and summarize all published studies of laboratory-confirmed GAS infection in Africa, (3) describe, from national laboratory data, the incidence of invasive and non-invasive GAS in South Africa and, (4) conduct a prospective, surveillance study in order to determine the molecular epidemiology of GAS in Cape Town, South Africa over a 12-month period. METHODS: A systematic review was conducted on population-based studies reporting on the prevalence of laboratory-confirmed GAS infection among patients living in Africa (Study 1). A retrospective study of the incidence of GAS infection was conducted on data obtained from the National Health Laboratory Service between 2003 – 2015 (Study 2). The AFROStrep registry and biorepository (based in Cape Town) was established and through passive surveillance, laboratory confirmed invasive and non-invasive GAS cases were collected over a 12-month period. The molecular analysis of invasive and non-invasive infection was determined using emm type sequencing to provide insight into vaccine development (Study 3). RESULTS AND DISCUSSION: The pooled prevalence of GAS pharyngitis in Africa was determined to be 21% (95% CI, 17% to 26%). The incidence rates of laboratory-confirmed non-invasive GAS infection in the South African public sector appears to have declined over the last 13 years. Given the possibility that the lower incidence of invasive and non-invasive GAS infection found in our study is due to infrequent submission of specimens for microbiological culture by health practitioners, our findings may be an underestimate of the true burden of disease in South Africa. In our prospective surveillance study, 46 different emm types were identified. The most prevalent emm types were M76 (16% of isolates), M81 (10%), M80 (6%), M43 (6%), and M183 (6%) and were almost evenly distributed between invasive and non-invasive GAS isolates. When compared against the putative 30-valent vaccine under development, four of our most prevalent emm types are not included; vaccine coverage (i.e. vaccine type and non-vaccine type-killing) for non-invasive and invasive GAS infection in our setting was 60% and 59% respectively, notably lower than coverage in developed countries. CONCLUSION: This work provides evidence for a significantly high prevalence of GAS pharyngitis in Africa. While GAS surveillance in South Africa indicates a declining incidence of GAS disease in parts of the country over the last thirteen years, the findings may be an underestimate of the true burden of disease, demonstrating the need for accurate and comprehensive surveillance of GAS in South Africa. Finally, this research showed a low potential vaccine coverage in our setting and thus, emphasises the need for a reworking of the potential vaccine formulation to improve coverage in areas where the burden of disease is high.
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Salloum, Mazen. "Les infections à "Streptococus agalactiae" chez l'adulte : emergence et impact de la lysogénie." Thesis, Tours, 2010. http://www.theses.fr/2010TOUR3144/document.
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Streptococcus Agalactiae est depuis les années 1990, responsable d'infections invasives émergentes chez l'adulte. Nous montrons queles souches responsables de ces infections appartiennent majoritairement aux sérotypes V et Ia et aux deux clones phylogénétiquement éloignés, CC1 et CC23. L'étude du contenu prophagique montre une lysogénie fréquente suggérant l'importance de la lysogénie dans la spécialisation de ces souches particulièrement aptes à infecter l'adulte. Dans un deuxième temps, nous avons isolé sept phages tempérés de souches associées à des infections cutanées et ostéo-articulaires. Ces phages appartiennent à la famille des SIPHOVIRIDAE. L’analyse par restriction enzymatique de l’ADN phagique et l’amplification par PCR de fragments d’ADN prophagique a montré la diversité de ces phages et leurdifférence des phages isolés de souches associées aux infections materno-foetales. Les phagesisolés de souches lysogènes de CC1 ont présenté un spectre lytique étendu aux souches de tous les clones intra-speciesStreptococcus agalactiae has emerged since 1990 in infections in nonpregnant adults, We showed that the strains isolated from adult infections were mainly of serotypes V and Ia., and mainly belonged to the two phylogenetically distant clones, CC1 and CC23. The prophagic content study showed a frequent lysogeny, suggesting a role of lysegeny in the specialization of these strains able to infect adult. Also, we isolated seven phages from strains associated with cutaneous and osteoarticular infections in adult. Ces phages classified among SIPHOVIRIDAE. Restriction analysis of phagic DNA and PCR for prophagic DNA showed genetiacally diverse phages, distinct from the phages isolated from strains responsible for materno-foetal infections. Phages isolated from lysogenic strains of CC1 had a wide lytic spectrum and were able to lyse strains belonging to all clones intra-species
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Power, Daniel Aaron, and n/a. "Non-culture based studies of the human upper respiratory tract microbiota and preliminary considerations of the influence of bacteriocin producing commensal and pathogenic oral streptococci." University of Otago. Department of Microbiology & Immunology, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070620.160726.
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The upper respiratory tract (URT) of humans is complex and interconnected region and comprises several major ecosystems including the oral cavity, oropharynx, nasal cavity, sinuses, nasopharynx and middle ear. Most of the anatomical locations within the URT are colonised with a normal bacterial microbiota, within which are often organisms having the potential to cause disease. The diseases of the URT are both varied and frequent in their occurrence, and conditions such as otitis media, rhinosinusitis and pharyngitis are sources of morbidity and mortality in adults and children in both developing and developed countries.
The study of diseases of the URT has traditionally been based on application of culture-based methods in which the infection-implicated organisms are first grown in vitro and then studied further. Ongoing advances in DNA-based techniques have led to the development of new molecular tools for the study of infectious diseases. One such technique is PCR-denaturing gradient gel electrophoresis (PCR-DGGE). This is a PCR-based tool that allows the investigation of microbial communities independent of culture. Although this technique has been applied extensively in the study of the gastrointestinal tract, the vagina and endodontic infections in humans, there have been few reports of its application to URT infections. PCR-DGGE was applied in the present study to investigate (a) the bacteria present in the middle ear of children suffering from otitis media with effusion (OME), (b) the microbiota associated with the sinuses in patients with chronic rhinosinusitis (CRS) and (c) perioperative changes in the bacterial population of the middle meatus of patients undergoing nasal or sinus surgery. The analysis of the middle ear fluid samples indicated an increased role in OME for the newly-discovered pathogen Alloiococcus otitidis and also the possible involvement of certain coryneform bacteria and coagulase-negative staphylococci in the aetiology of this condition. PCR-DGGE analysis of patients with CRS revealed a polymicrobial disease with considerable variability in the predominant species detected when multiple, serial samples were evaluated. The perioperative audit showed that when good clinical practice is adhered to, there was no apparent introduction of potentially-harmful organisms into the middle meatus.
Streptococcus salivarius is a common, commensal inhabitant of the oral cavity of humans and has also been shown to inhabit the nasopharynx of infants. S. salivarius is also a well known producer of bacteriocins with activity directed against Streptococcus pyogenes. One such strain, S. salivarius K12, is now marketed in New Zealand as the probiotic, K12 Throat Guard[TM]. In the present study, S. salivarius K12 was compared with two additional strongly-inhibitory S. salivarius (strains T18A and T30A) for activity against the common causative pathogens of otitis media. A paediatric formulation of strain K12 was also tested in a pilot clinical trial for its ability to colonise the URT of young children. Although the levels of colonisation of these subjects was not as high as typically obtained with use of the K12 Throat Guard[TM] formulation, it was considered that further development of the paediatric formulation is warranted, particularly with respect to use of a different pre-treatment regimen. In other studies, the molecular basis for the unusual in vitro inhibitory activity of S. salivarius strain T30A was investigated. Although this still remains unresolved, other observations made during the course of this study have led to the introduction of a schema for the division of inhibitory S. salivarius into three groups based on (a) their sensitivity to the lantibiotic salivaricin A and (b) the structure of their salivaricin A genetic locus. This grouping is analogous to the "rock-paper-scissors" system previously described for colicin-producing strains of E. coli.
Streptococcus pneumoniae is a major human pathogen responsible for a variety of diseases in humans. There have been very few reports of bacteriocin production by S. pneumoniae when compared to other streptococcal species. In the present study a putative cluster of bacteriocins encoded by the blp locus has been investigated. The distribution of the individual blp determinants within this locus was evaluated in a collection of S. pneumoniae strains using PCR. The blp genes were detected in 92% of 57 tested strains and a variant form (termed the B-form) of the cluster was identified that appeared to have arisen due to a genetic recombination event. In this case an approximately 250 bp portion of the blpMNO cluster appears to have recombined into blpK of the blpIJK cluster. Attempts were made to express the putative bacteriocin peptide genes in an Escherichia coli expression system. Failure to achieve expression was taken to indicate that these bacteriocin-like peptides may be toxic for the host producer cells under these test conditions. Future attempts to achieve expression of the Blp peptides, could explore the use of different fusion proteins, a Gram-positive expression host or a cell-free protein expression system.
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Jarvis, Christopher D. "Mouse Antibody Response to Group A Streptococcal Carbohydrate: A Thesis." eScholarship@UMMS, 1989. https://escholarship.umassmed.edu/gsbs_diss/227.
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In an attempt to more fully understand the generation of antibody diversity to carbohydrate antigens, we produced and characterized a panel of hybridoma cell lines specific for group A streptococcal carbohydrate from mice injected with the intact bacteria (minus the hyaluronic acid capsule and cell wall protein antigens). We have analyzed the use of heavy and light chain variable region genes in the early (day 7) and late response (hyperimmune) and have determined the nucleotide sequence of the dominant VH gene used in several of our hybridomas. Our data allowed us to assess the extent to which the recombination of various V, D, and J gene segments and somatic mutation contribute to antibody diversification in this system. In this report we confirm that a minimum of two VH and four VK gene segments are used to encode this response. We extend this analysis to show that multiple D and J gene segments are used and that a significant amount of junctional variability is tolerated in CDR 3. Our results also suggest that there is a positive selection for somatic mutation in CDR 1 during the hyperimmune response to group A streptococcal carbohydrate.
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Sanderson-Smith, Martina Louise. "Investigation of the role of the plasminogen-binding group A streptococcal M-like protein (PAM) in the pathogenesis of Streptococcus pyogenes." Access electronically, 2006. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20070821.125843/index.html.
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Tong, Jie [Verfasser]. "Co-infection of respiratory epithelial cells by respiratory viruses and streptococci / Jie Tong." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2018. http://d-nb.info/1162715758/34.
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Schirm, Sibylle, Peter Ahnert, Sandra Wienhold, Holger Müller-Redetzky, Geraldine Nouailles-Kursar, Markus Löffler, Martin Witzenrath, and Markus Scholz. "A biomathematical model of pneumococcal lung infection and antibiotic treatment in mice." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-204153.
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Pneumonia is considered to be one of the leading causes of death worldwide. The outcome depends on both, proper antibiotic treatment and the effectivity of the immune response of the host. However, due to the complexity of the immunologic cascade initiated during infection,
the latter cannot be predicted easily. We construct a biomathematical model of the murine immune response during infection with pneumococcus aiming at predicting the outcome of antibiotic treatment. The model consists of a number of non-linear ordinary differential
equations describing dynamics of pneumococcal population, the inflammatory cytokine IL-6, neutrophils and macrophages fighting the infection and destruction of alveolar tissue due to pneumococcus. Equations were derived by translating known biological mechanisms
and assuming certain response kinetics. Antibiotic therapy is modelled by a transient depletion of bacteria. Unknown model parameters were determined by fitting the predictions of the model to data sets derived from mice experiments of pneumococcal lung infection with and without antibiotic treatment. Time series of pneumococcal population, debris, neutrophils, activated epithelial cells, macrophages, monocytes and IL-6 serum concentrations were available for this purpose. The antibiotics Ampicillin and Moxifloxacin were considered. Parameter fittings resulted in a good agreement of model and data for all experimental scenarios. Identifiability of parameters is also estimated. The model can be used to predict the performance of alternative schedules of antibiotic treatment. We conclude that we established a biomathematical model of pneumococcal lung infection in mice allowing predictions regarding the outcome of different schedules of antibiotic treatment. We aim at translating the model to the human situation in the near future.
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Dua, Priyamvada. "Functional effects of anti-neuronal antibodies in patients with encephalitis lethargica and related disorders associated with streptococcal infection." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8704.
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Encephalitis lethargica affected a large number of people in the pandemic in the early 1900s (von Economo, 1930). Histological and biochemical data suggest that autoimmune mechanisms play an important role in this disorder and recently serum anti-basal ganglia antibodies (ABGA) have been detected in affected sporadic cases associated with evidence of recent streptococcal infection (Dale et al., 2004a). ABGA are also associated with other neuropsychiatric disorders including Sydenhams chorea, paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections, Tourettes syndrome and obsessive compulsive disorder. The precise frequency, presentation, disease course, treatment response and causes of these disorders are still unknown. As ABGA are strongly associated with recent streptococcal infection, these disorders represent a potentially good model for the study of molecular mimicry and autoimmunity. The present study focussed on various aspects of this group of disorders. Profiling of group A streptococcus isolates from both patients with postulated post-streptococcal disorders of the CNS and controls was done which highlighted differences in virulence factors like M protein and superantigens between the two groups. Also in the present study we demonstrated the pathogenicity of anti-neuronal antibodies found in patients in both an in vivo and in vitro setting. An animal model of the disorders was produced by passive transfer of antibodies from patients which resulted in symptoms reminiscent of diseases like encephalitis lethargica and dystonia. An active immunization animal model using GABHS proteins and recombinant proteins (putative autoantigens) was also developed. Furthermore, the autoantibodies from patients and animal models were analysed on both neuronal and non-neuronal cells where they demonstrated to have a functional effect on cytotoxicity, apoptosis, calcium flux and enolase activity. N-methyl D-aspartate glutamate receptor and voltage gated potassium channel have been recently been implicated in a 16 range of neurological disorders, hence we also tested the patient sera for antibodies against these receptors and found a group of patients to be positive. In summary, EL and other ABGA-associated disorders are still an emerging entity, with major implications for neuropsychiatry. As auto-antibody mediated diseases respond to immunomodulatory therapy, identifying and defining the pathogenesis of these disorders is important so that patients can be appropriately treated.
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Deicke, Christin [Verfasser], and Manfred [Akademischer Betreuer] Rohde. "The role of coagulation factor XIII in the early innate immune response against streptococcal infections / Christin Deicke ; Betreuer: Manfred Rohde." Braunschweig : Technische Universität Braunschweig, 2015. http://d-nb.info/1175818925/34.
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Kong, Fanrong. "Integrated study of group B streptococcus and human ureaplasmas � the paradigm shifts." University of Sydney. Medicine, 2004. http://hdl.handle.net/2123/592.
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Group B streptococcus (GBS, S. agalactiae) and human ureaplasmas (U. parvumand U. urealyticum) are two clinically and phylogenetically related, potential perinatal pathogens. Their relationships between genotypes and pathogenesis of GBS and ureaplasma infection were still not well understood, one of the reason is that both of them are still short of a very practical genotyping system. In the study, to solve the above problem we developed genotyping systems for the organisms (the second section). For human ureaplasmas, based on four genes/gene clusters (rRNAgene clusters, the elongation factor Tu genes, urease gene complexes and multiplebanded antigen genes), we designed many primer pairs suitable for developing species identification assays for the two newly established human ureaplasma species (U. parvum and U. urealyticum). Further, based on the heterogeneity of ureaplasma multiple banded antigen gene (which contains species- and serovar-specific regions), we developed genotyping methods for each ureaplasma species.For GBS, based on three sets of molecular markers (capsular polysaccharidesynthesis gene clusters, surface protein antigen genes and mobile genetic elements),we developed a genotyping system. The primary evaluation of the genotyping systems showed that the genotyping systems were practical alternative assays for the conventional serotyping and they will be useful to further explore the relationships between genotypes and pathogenesis of GBS and ureaplasma infection. In the study, we introduced novel data and tools into GBS and ureaplasma studies especially from genomic- and bioinformatics-based molecular microbiology(the third section). For two newly established human ureaplasma species, based on the U. parvum serovar-3 genome, and using the above four important genes/geneclusters, we exposed some interesting problems in the understanding of newureaplasma taxonomy especially in the post genomic era. For GBS, we studied the two published full genomes and exposed some new problems or possible future new research fields. In particular we found the two finished and one ongoing GBS genomes were all non-typical and suggest that future genomic project had better have genetic population structure viewpoint. Finally, we suggested that integrated studies of the two potential or conditional perinatal pathogens, from the viewpoint of evolution, would provide a new understanding angle of the pathogenesis of the two organisms. Studies suggested that during coevolution, human ureaplasmas(especially U. parvum) became friendlier than their ancestors to their human host (by losing most of its virulence genes); however, GBS tried to increase its invasive abilities (by getting more virulence genes) to fight against the human host attack.
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Walker, Kate. "Trends in birthweight and infant weights : relationships between early undernutrition, skin lesions, streptococcal infections and renal disease in an Aboriginal community /." Connect to thesis, 1996. http://repository.unimelb.edu.au/10187/2406.
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Undernutrition in prevalent in Aboriginal communities, in utero, infancy and childhood. It influences childhood morbidity and mortality and growth patterns. Undernutrition and poor socio-economic status also contribute to endemic and epidemic infectious disease, including scabies and streptococcal infection. It has been suggested that early undernutrition, and streptococcal and scabies infection are risk factors for renal disease, which is at epidemic levels and increasing. This thesis examines the prevalence of undernutrition in newborns and infants in an Aboriginal community over time, and its impact on childhood growth and child and adult renal markers. The association between skin lesions, streptococcal serology, post-streptococcal glomerulonephritis (PSGN) and renal markers as evaluated through a community wide screening program in 1992-1995 is also examined. Birthweights have increased since the 1960s, but they are still much lower than the non-Aboriginal values. Weights in infancy have decreased since the 1960s. At screening in childhood stunting was common, reflecting the presence of long-term poor nutrition in infancy. In both adults and children, birth weight and infant weights were negatively associated with albuminuria measured by the albumin to creatine ratio (ACR).
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Chella, Krishnan Karthickeyan. "Host-Pathogen Interactions Promoting Pathogen Survival and Potentiating Disease Severity & Morbidity in Invasive Group A Streptococcal Necrotizing Soft Tissue Infections." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1446546952.
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Seanego, Christinah Tshephisho. "Phytochemical analysis and bioactivity of Garcinia Kola (Heckel) seeds on selected bacterial pathogens." Thesis, University of Fort Hare, 2012. http://hdl.handle.net/10353/420.
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Garcinia kola is one of the plants used in folklore remedies for the treatment of microbial infections. Bacterial resistance to commonly used antibiotics has necessitated the search for newer and alternative compounds for the treatment of drug resistant microbial infections. This study focuses on the bioactivity of G. kola seeds on Streptococcus pyogenes (ATCC 49399), Staphylococcus aureus (NCTC 6571), Plesiomonas Shigelloides (ATCC 51903) and Salmonella typhimurium (ATCC 13311), organisms which can cause illnesses from mild to severe with potentially fatal outcomes. The crude ethyl acetate, ethanol, methanol, acetone and aqueous extracts were screened by agar-well diffusion method and the activities of the extract were further determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. The inhibition zones ranged from 0 - 24 mm, while MIC and MBC of the extract ranged between 0.04 - 1.25 mg/mL and 0.081 - 2.5 mg/mL respectively. Chloroform/ Ethyl Acetate/ Formic acid (CEF) solvent system separated more active compounds followed by Ethyl Acetate/ Methanol/ Water (EMW) and Benzene/ Ethanol/ Ammonium Hydroxide (BEA). The extracts were fractionated by Thin Layer Chromatography (TLC). Bioautography was used to assess the activity of the possible classes of compounds present in the more active extracts. Column chromatography was used to purify the active compounds from the mixture while Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify the phyto components of the fractions. The MIC of the fractions ranged between 0.0006 - 2.5 mg/mL. CEF 3 (F3), CEF 11 (F11) and CEF 12 (F12) revealed the presence of high levels fatty acids Linoleic acid, 1, 2-Benzenedicarboxylic acid and 2, 3-Dihydro-3, 5-dihydroxy-6-methyl, respectively. The results obtained from this study justify the use of this plant in traditional medicine and provide leads which could be further exploited for the development of new and potent antimicrobials.
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Cole, Jason Nicklaus. "Characterisation of cell wall proteins, virulence factor maturation and invasive disease trigger of Group A streptococcus." Access electronically, 2006. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20070130.144214/index.html.
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Koskenkorva, T. (Timo). "Outcome after tonsillectomy in adult patients with recurrent pharyngitis." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526207995.
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Abstract Recurrent pharyngitis causes doctor visits, antibiotics use and absences from school or work and thus worsens patients’ quality of life (QOL). Even though tonsillectomy is often performed for recurrent pharyngitis, there is limited evidence of the tonsillectomy benefit concerning both researcher- and patient-recorded outcomes. The intent of this work was to find out if tonsillectomy reduces numbers of pharyngitis episodes or symptom days, if tonsillectomy improves patients’ QOL and if there are any clinical factors predicting QOL benefit after tonsillectomy. Seventy adult patients with recurrent streptococcal pharyngitis (2001–2005) and 86 patients with recurrent pharyngitis of any origin (2007–2010) were enrolled for two randomised controlled trials. Patients with recurrent pharyngitis of any origin were followed up either before (control group, n=40) or after (tonsillectomy group, n=46) tonsillectomy. At five months of follow-up, 17 (43%) patients in the control group and 2 (4%) patients in the tonsillectomy group consulted a physician for pharyngitis. Thirty-two (80%) patients in the control group and 18 (39%) patients in the tonsillectomy group experienced any kind of pharyngitis episode. Only one episode was considered severe. The numbers of days with throat pain and fever were significantly lower in the tonsillectomy group. QOL of 142 responders measured by Glasgow Benefit Inventory (GBI) six months after tonsillectomy showed improvement: median GBI total score was +27. However, GBI total scores varied considerably between the patients (range −19 to +69). Only one patient reported declined QOL. The number of prior pharyngitis episodes, frequent throat pain, untreated dental caries and chronically infected tonsils were the best clinical factors predicting QOL improvement. The precision of these predictions was still quite low. The results of this work suggest that tonsillectomy reduces numbers of acute pharyngitis episodes and symptoms. Although most of the episodes are not severe, tonsillectomy still generally improves patients’ QOL. The distribution of QOL benefit is broad, however. Throat-related morbidity before tonsillectomy is the only clinical factor that was associated with patient satisfactionTiivistelmä Toistuvat nielutulehdukset aiheuttavat paljon lääkärikäyntejä, antibioottihoitoja sekä poissaoloja töistä tai opinnoista ja huonontavat potilaiden elämänlaatua. Toistuvien nielutulehdusten vuoksi päädytään usein nielurisaleikkaukseen, vaikka tutkimusnäyttö leikkauksen hyödystä on vähäistä. Tämän väitöskirjatyön tavoitteena oli tutkia, vähentääkö nielurisaleikkaus nielutulehdusten määrää tai oireita sekä selvittää leikkauksenjälkeistä elämänlaatua ja siihen liittyviä ennustekijöitä. Tutkimusaineisto koostui kahta eri satunnaistettua kliinistä koetta varten rekrytoiduista potilaista: 70 potilasta, joiden toistuvien nielutulehdusten aiheuttaja oli A-ryhmän streptokokki (2001–2005) ja 86 potilasta, joiden toistuvien nielutulehdusten etiologialle ei asetettu vaatimuksia (2007–2010). Potilaat, joilla nielutulehdusten etiologia oli avoin, satunnaistettiin kahteen ryhmään: kontrolliryhmää (n=40) seurattiin ennen nielurisaleikkausta ja leikkausryhmää (n=46) sen jälkeen, molempia 5 kuukauden ajan. Seurannassa 17 (43 %) kontrolliryhmän potilasta ja 2 (4 %) leikkausryhmän potilasta hakeutui lääkäriin nielutulehduksen vuoksi. Kontrolliryhmän potilaista 32 (80 %) ja leikkausryhmän potilaista 18 (39 %) sairasti nielutulehduksen vähintään kerran. Vain yksi episodi luokiteltiin vaikeaksi. Nielukipu- ja kuumepäiviä oli merkittävästi vähemmän leikkausryhmässä. Nielurisaleikkauksen vaikutusta elämänlaatuun tutkittiin Glasgow Benefit Inventory (GBI) -kyselyllä kuusi kuukautta leikkauksen jälkeen. Yhteensä 142 potilasta vastasi kyselyyn. GBI:n mediaanitulos +27 osoitti leikkauksen parantavan elämänlaatua. GBI-tulokset kuitenkin vaihtelivat huomattavasti potilaiden välillä (−19 – +67), vaikkakin vain yksi potilas raportoi elämänlaatunsa heikentyneen. Aiempien nielutulehdusten määrä, usein toistuva nielukipu, hoitamaton karies ja kroonisesti tulehtuneet nielurisat ennustivat parhaiten potilastyytyväisyyttä leikkauksen jälkeen, mutta näidenkin tekijöiden ennustearvo oli melko heikko. Tulosten perusteella nielurisaleikkaus vähentää akuutteja nielutulehduksia sekä oirepäiviä. Vaikka sairastamisjaksot ovat harvoin vaikeaoireisia, leikkaus parantaa useimmiten elämänlaatua, mutta hyödyn määrä vaihtelee merkittävästi potilaiden välillä. Ainoastaan leikkausta edeltävä nielun oireilun määrä ennustaa leikkaushyötyä jossain määrin
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Santos, Almeida Alexandre Miguel. "Evolutionary insights into the host--specific adaptation and pathogenesis of group B Streptococcus Persistence of a dominant bovine lineage of group B Streptococcus reveals genomic signatures of host adaptation Whole-Genome Comparison Uncovers Genomic Mutations between Group B Streptococci Sampled from Infected Newborns and Their Mothers." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066029/document.
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Streptococcus agalactiae (streptocoque du groupe B, SGB) est un commensal fréquent des voies intestinale et génito-urinaire dans la population humaine mais constitue une des causes principales d'infections néonatales. Dans le même temps, SGB est connu comme pathogène vétérinaire, responsable de mastites bovines à l'origine de pertes économiques importantes dans plusieurs pays comme le Portugal. L'objectif de ma thèse était d'analyser au niveau génomique les bases de l'adaptation spécifique de SGB à ses hôtes humains et bovins et de l'établissement des lignées plus pathogènes. La comparaison des profils génomiques des souches isolées de nouveau-nés infectés et de leurs mères nous a permis de montrer que la transmission de SGB de mère à enfant est accompagnée dans certains cas par l'acquisition de mutations pathoadaptives. Par ailleurs, l'analyse des séquences génomiques de plus de 600 souches appartenant au complexe clonal (CC) 17, hypervirulent et spécifique à l'hôté humain, nous a permis de caractériser les forces évolutives agissant sur ce complexe. Finalement, l'étude de la colonisation des fermes laitières portugaises par un seul clone CC61 depuis plus de 20 ans a mis en évidence que la régulation spécifique de l'import du fer/manganèse est une stratégie d'adaptation récurrente dans l’environnement bovin. En conclusion, les résultats que nous présentons améliorent notre compréhension de l'adaptation chez les espèces hôte-généralistes, en apportant des idées utiles qui pourront spécifiquement aider à améliorer le contrôle et le traitement des infections de SGB mondialementStreptococcus agalactiae (group B Streptococcus, GBS) is a commensal of the intestinal and genitourinary tracts in the human population, while also a leading cause of neonatal infections. Likewise, GBS remains a serious concern in many countries as frequently responsible for bovine mastitis. Therefore, the purpose of my PhD project was to use state-of-the-art whole-genome approaches to decipher the host-specific adaptation and pathogenesis of GBS in both humans and bovines. By comparing the genomic profile of strains from infected newborns and their mothers we showed that the transmission of GBS from mother to child is accompanied in particular instances by the acquisition of specific pathoadaptive mutations. Moreover, from the study of the evolutionary forces acting on the human-specific and hypervirulent clonal complex (CC) 17, we reveal that various systems can evolve to improve the ability of GBS to survive in the human host. Functions related to metabolism, cell adhesion, regulation and immune evasion were among the most preferentially affected in GBS strains from human origin. Conversely, colonization of Portuguese dairy farms by one single CC61 clone for over 20 years highlighted that the specific regulation of iron/manganese uptake is a recurrent adaptive strategy in the bovine environment
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Skull, Susan. "Effectiveness of influenza and pneumococcal vaccination against hospitalisation for community-acquired pneumonia among persons >65 years /." Connect to thesis, 2007. http://repository.unimelb.edu.au/10187/1998.
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Although there are well-documented benefits from influenza vaccine and 23-valent pneumococcal polysaccharide vaccine (23vPPV) against invasive pneumococcal disease and laboratory confirmed influenza, their effectiveness against pneumonia remains controversial for community-based persons aged >=65years. At the time of this research, within Australia, only the government of Victoria publicly funded these vaccines for elderly persons. With continued growth of the elderly population, the subsequent adoption of an Australia-wide program, and increasing uptake of similar programs in other countries, there is a need for data clarifying the impact of vaccination on pneumonia. This research estimates incremental vaccine effectiveness of 23vPPV over and above influenza vaccine against hospitalisation with community-acquired pneumonia (CAP) in the elderly.
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Cardoso, Debora Morais. "Impacto do uso de técnicas microbiológicas para o estreptococo beta hemolítico do grupo A no diagnóstico e tratamento das faringotonsilites." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/5/5141/tde-04082015-094743/.
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INTRODUÇÃO: A Faringotonsilite é doença comum nos consultórios e prontosocorros de pediatria. OBJETIVOS: Avaliar o impacto da realização rotineira da prova rápida para pesquisa de estreptococo do grupo A (PRE) no diagnóstico e tratamento da faringotonsilite aguda em crianças e adolescentes atendidos em um Hospital Geral. MÉTODOS: Trata-se de um estudo prospectivo, observacional, de protocolo de atendimento, instituído no Pronto-Socorro do Hospital Universitário da Universidade de São Paulo para o atendimento de crianças e adolescentes com diagnóstico de faringotonsilite aguda. RESULTADOS: Foram estudadas 1039 crianças e adolescentes. Com base no quadro clínico, antibiótico seria prescrito em 530 pacientes (51%), e com o uso da PRE e/ou cultura de orofaringe foi prescrito em 268 (25,8%) pacientes. Das 509 crianças que não receberiam antibiótico pelo quadro clínico, 157 tiveram PRE e/ou cultura de orofaringe positiva. O diagnóstico baseado no quadro clínico apresentou sensibilidade de 63,06% (IC-95%:62,95-63,17%); especificidade de 57,33% (IC-95%:57,25-57,41%); valor preditivo positivo de 50,57% (IC-95%:50,47-50,66%) e valor preditivo negativo de 69,16% (IC-95%: 50,47-50,66%). CONCLUSÕES: Neste estudo o diagnóstico clínico da faringotonsilite estreptocócica mostrou baixa sensibilidade e especificidade. O uso rotineiro da prova rápida para pesquisa de estreptococo permitiu uma redução do uso de antibiótico e a identificação de crianças e adolescentes com faringotonsilite estreptocócicas que não receberiam antibiótico e estariam sob o risco das complicações da infecção estreptocócicaBACKGROUND: Sore throat is a common disease in the pediatric emergency room. OBJECTIVES: The objective of this study was to evaluate the impact of routine performance of rapid antigen detection test (RADT) in the diagnosis and treatment of acute pharyngitis in children treated at an academic hospital. METHODS: This is a prospective, observational, protocol compliance, established at the Emergency of Hospital Universitário - Universidade de São Paulo for the care of children and adolescents diagnosed with acute pharyngitis. RESULTS: We studied 1039 children and adolescents. Based on clinical findings, antibiotic would be prescribed in 530 patients (51%) and using the RADT or sore throat culture was prescribed in 268 patients. Of the 509 children who did not receive antibiotics for the clinical, 157 had positive RADT or sore throat culture. The diagnosis based on clinical sensitivity was 63,06% (IC 95% 62,95- 63,17%), specificity 57,3% (IC 95% 57,25-57,41%), positive predictive value of 50,57% (IC 95% 50,47-50,66%) and negative predictive value of 69,16% (IC 95% 50,47-50,66%). CONCLUSIONS: In this study the clinical diagnosis of streptococcal pharyngitis had low sensitivity and specificity. The routine use of rapid test for streptococcal research led to a reduction of antibiotic use and the identification of a risk group for complication of streptococcal infection
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Guet-Revillet, Hélène. "Métagénomique bactérienne de l'hidrosadénite suppurée." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05T065/document.
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L’hidrosadénite suppurée (HS) ou maladie de Verneuil, est une maladie cutanée orpheline fréquente qui touche 1 % de la population générale. Elle se manifeste par des lésions inflammatoires récidivantes ou chroniques des plis axillaires, inguinaux et périnéaux. La sévérité clinique de la maladie varie selon les patients. Les lésions les moins sévères (lésions de stade 1 dans la classification de sévérité clinique de Hurley) sont des nodules inflammatoire centimétriques pouvant évoluer vers l’abcédation. Les lésions les plus sévères (lésions de stade 2 et 3 de Hurley) sont des lésions suppurées étendues et chroniques. Sur le plan histologique, la lésion primitive de l’HS semble être une hyperplasie de l’épithélium du follicule pileux. La physiopathologie de la maladie est mal connue et probablement multifactorielle, incluant des facteurs génétiques, hormonaux, infectieux et dys-immunitaires. Il a été montré récemment qu’une antibiothérapie à large spectre pouvait permettre d’obtenir une rémission clinique prolongée des lésions inflammatoires de l’HS. Objectif du travail : L’objectif principal de ce travail était d’identifier par des techniques de culture classique et de métagénomique bactérienne les espèces ou les flores bactériennes spécifiquement associées aux lésions d’HS des trois stades de sévérité clinique. Résultats : Nous avons identifié par culture bactérienne deux profils bactériens lésionnels. Le premier était représenté par Staphylococcus lugdunensis, et plus rarement par d’autres espèces bactériennes de la flore cutanée commensale (Propionibacterium acnes, staphylocoques à coagulase négative et Staphylococcus aureus). Le second correspondait à une flore anaérobie composée de bactéries anaérobies stricts, d’Actinomycetes et de streptocoques du groupe milleri. L’approche métagénomique a permis d’identifier les germes anaérobies stricts associés aux lésions : des cocci à Gram positif de la flore cutanée (principalement Anaerococcus spp., Peptoniphilus spp., Finegoldia spp.) des bacilles à Gram négatif anaérobies n’appartenant pas à la flore cutanée (Prevotella spp., Porphyromonas spp., Fusobacterium spp), Veillonellaceae et Corynebacteriaceae. Ce profil était caractéristique des lésions suppurées chroniques de stade 2 et 3 et était également associé à certaines lésions de stade 1. Les lésions des stades 2 et 3 présentaient une diversité bactérienne supérieure à celle des lésions de stade 1, avec un nombre plus élevé de taxons très minoritaires dans la flore cutanée (Fusobacteria, Bacteroidetes, Peptococcaceae, Erysipelotrichales). Conclusion : Cette étude démontre que certaines espèces bactériennes sont spécifiquement associées aux lésions d’HS. Ces espèces sont impliquées dans des infections cutanées, mais aussi dans des infections sévères, ce qui témoigne de leur pathogénicité. L’efficacité des antibiotiques chez les patients et les résultats de cette étude suggèrent qu’un processus infectieux participe à la présentation clinique de l’HS. Notre hypothèse est que ces infections surviennent en raison d’une anomalie primitive de la barrière cutanée folliculaireHidradenitis suppuratiav (HS) is an orphan skin inflammatory disease disease characterized by chronic or recurrent inflammatory lesions localized in the armpits, the inguinal and perineal folds. With a 1% prevalence of a general population, HS is an public health issue. The clinical severity of the disease is heterogeneous among patients. Most patients present the mild form of the disease with inflammatory nodules and abscesses (Hurley stage 1 lesions). More severe patients show extended chronically suppurating lesions (Hurley stage 2 and Hurley stage 3 lesions). The primary histological lesion of HS is characterized by epidermal follicular hyperplasia and perifollicular inflammation. The physiopathology of HS remains unclear. HS is probably a multifactorial disease, involving genetical, immunological and infectious factors. Indeed, wide-spectrum antibiotic treatments can significantly improve or induce prolonged clinical remissions of HS inflammatory lesions. Objective: The main objective of this work was to identify the bacterial species or flora specifically associated with Hurley stage 1, 2 and 3, using prolonged aerobic and anaerobic culture and bacterial metagenomics (454 sequencing of 16Sr DNA libraries). Results. Using bacterial culture, we identified two bacterial profiles associated with HS lesions . The first one was represented by Staphylococcus lugdunensis and rarely by other skin commensals (Propionibacterium acnes, coagulase negative staphylococci and Staphylococcus aureus). Results. The second one corresponded to a mixted anaerobic flora including strict anaerobes, Actinomycetes and milleri group streptococci. The metagenomic approach allowed to identify the anaerobic flora associated with lesions : Gram positive cocci from the cutaneous flora (mainly Anaerococcus spp., Peptoniphilus spp., Finegoldia spp.) and Gram negative rods which do not belong to the cutaneous microbiota (Prevotella spp., Porphyromonas spp., Fusobacterium spp), Veillonellaceae and Corynebacteriaceae. This profile was typically associated with Hurley stage 2 and 3 lesions but was also observed in Hurley stage 1 lesions. Hurley stage 2 and 3 lesions presented an increased bacterial diversity as compared to Hurley stage 1 lesions, with a higher number of taxa taxa rarely associated with normal skin microbiota (Fusobacteria, Bacteroidetes, Peptococcaceae, Erysipelotrichales). Conclusion. This study demonstrate that particular bacterial species are specifically associated with HS lesions. These species are cause soft tissue and skin infections, but also in severe infections arguing for their pathogenicity. These data provide a rationale for antibiotic use in HS, and suggests that the disease may be due to a primitive immune defect of the follicular skin barrier
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TSAI, MENG-CHUN, and 蔡孟珺. "PCR Assays Taiwan Farmed Fish Streptococcal Infection and Iridovirus Infection." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/21025428976276444439.
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碩士國立臺北教育大學
自然科學教育學系
105
Streptococcus spp. and Iridovirus often cause a large number of deaths from cultured fish, and epidemiology is widely distributed in southern Taiwan. Streptococcal infection was treated with Tilapia (Tilapia nilotica x Tilapia aurea) and Perch (Lates calcarifer). Sick fish will have hemorrhagic sepsis, mainly swimming is not normal, body color black, prominent eye, mouth and gill cover bleeding phenomenon. In this study, we should explore the pathogen, take the diseased fish spleen for bacterial isolation and purification. 16S rDNA and 16S-23S rDNA PCR were carried out and the product was cloned and sequenced. The results were compared with those in GenBank. 16S rDNA is 1500 bp, 16S-23S rDNA of Tilapia is 600 bp, 16S-23S rDNA of Perch is 800 bp, it can be seen from the Tilapia isolated for the Streptococcus agalactiae; Perch isolated for the Streptococcus iniae. Iridovirus infection often causes a large number of deaths of grouper (Epinephelus spp.). In the province, the sick fish have no obvious signs of appearance, but their breathing is reduced, the feeding rate is reduced and the activity is reduced. Sick fish gill tablet can be seen giant cells, and internal organs splenomegaly, sliced observation in the gills and spleen can also be seen huge cells exist. In the spleen organs can be seen in the basophilic nuclear inclusion body. In this study, we should quickly explore the pathogen, take the internal organs of diseased fish for tissue sections and H&E staining. Take the spleen tissue 0.3 g, the tissue grinding and made of emulsion. Centrifuge, take the supernatant, quantitative 0.1 (μg/μl). In the GenBank to obtain a pair of primers, respectively CY15n-F, CY15n-R, PCR amplifycation, available 1,339 bp, you can confirm the infection iridovirus. Therefore, effective application PCR technology to detect fish farming, can increase the income of farmers.
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Hua, Guo Li, and 郭力華. "Role of Cystatin C in Streptococcal Infection." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/99824618664773109157.
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Li, Ming-han, and 李明翰. "Protective effect of dextromethorphan in group A streptococcal infection." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/51256700707233096841.
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碩士國立成功大學
微生物及免疫學研究所
96
Group A streptococcus (GAS) is an important human pathogen that causes a wide spectrum of disorders, ranging from mild infections to severe invasive diseases such as necrotizing fasciitis and streptococcal toxic shock syndrome. Patients suffering from severe invasive infection have higher levels of inflammatory cytokines and nitric oxide (NO) compared with non-invasive infection. Dextromethorphan (DM) is a widely-used anti-tussive drug. Recent reports show that DM has anti-inflammatory properties through reducing the levels of reactive oxygen species and inflammatory cytokines including TNF-�� and IL-6. In the present study, we investigate the potential protective effect of DM in GAS infection. Our results showed that DM treatment increased the survival rate of GAS-infected mice. DM administration reduced bacterial numbers and increased neutrophil viability in local infection site. Moreover, DM treatment prevented bacterial dissemination to the blood and reduced serum levels of proinflammatory cytokines and chemokines. In addition, examination of liver histology and serum AST and ALT levels in GAS-infected mice revealed that DM reduced liver injury. Further in vitro studies showed that GAS induced NF-�羠 activation in macrophages and DM treatment reduced this activation. DM also reduced iNOS expression and NO production in GAS-infected macrophages. Taken together, DM treatment increased the viability of infiltrated neutrophils and reduced systemic inflammatory responses to provide the protective effect in GAS infection.
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WANG, CHIH-HUNG, and 王志宏. "Roles of Oligopeptide Permease in Group A Streptococcal Infection." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/22117739200162916308.
Full textAbstract:
博士國立成功大學
基礎醫學研究所
93
Group A streptococcus (GAS) is an important human pathogen that causes pharyngitis, toxic shock syndrome and many other human respiratory tract and tissue infections. The oligopeptide permease (Opp) of GAS is a membrane-associated protein and belongs to the ABC-transporter family. It is coded from a polycistronic operon containing oppA, oppB, oppC, oppD and oppF. The biological function of these genes is not clear in GAS. To understand the role of Opp on streptococcal infection, an isogenic oppA mutant was constructed by using an integrative plasmid to disrupt the opp operon and confirmed by Southern blot hybridization and RT-PCR. The oppA isogenic mutant not only decreased transcription of speB, speX, and rofA, but also increased transcription of speF, sagA (streptolysin S associated gene A), slo (streptolysin O), pel (pleotrophic effect locus), and dppA (dipeptide permease). No effects were found on transcription of emm, speJ, speG, rgg, and csrR. The oppA mutant caused more dissemination and less mortality and tissue damage than the wild-type strain when inoculated into BALB/c mice. The efficiency of adhesion to and internalization by host cells decreased about 50% and 46%, respectively, in opp mutant strain compared with those of the wild-type strain. The pull down and western blot assays showed that Opp may trigger the Rac, Rho activation, FAK and JNK phosphorylation of A549 cells and caused cytoskeleton rearrangement after GAS infection. Immunoflouresence staining and transmission electromicroscopy demonstrated that Opp mediated the tight junction open in A549 and MDCK cells. This would lead to open the cell tight junction that enhances GAS entry to deeper tissue. Based on these data, we conclude that the opp operon plays two important roles in the pathogenesis of group A streptococcal infection. First, Opp can regulate several important streptococcal virulence factors and regulators which would lead to severe mortality in BALB/c mice. Second, Opp can trigger host signal transduction that enhances streptococcal adhesion, internalization and invasion.
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Luengpailin, Somkiat. "Fluoride downregulates glucan-binding lectin in streptococci." 1997. http://catalog.hathitrust.org/api/volumes/oclc/47912284.html.
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Chih-Feng, Kuo, and 郭志峰. "Role of Streptococcal Pyrogenic Exotoxin B in Streptococcus Pyogenes infection." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/08993316894688672757.
Full textAbstract:
博士國立成功大學
基礎醫學研究所
87
The group A streptococcus ((Streptococcus pyogenes) casuses a broad spectrum of diseases. Clinical features that result in life-threatening sequelae of these infections include necrotizing fasciitis and streptococcal toxic shock syndrome. However, so far, their pathogenic factor is poorly defined. High-level protease activity of the invasive clinical isolates are significantly associated with the clinical signs of necrotizing fasciitis and with mortality. The gene of streptococcal pyrogenic exotoxin B (SPE B) is found in all strains of S. pyogenes, and the encoded protein functions as a cysteine protease. In order to study the role that SPE B may play in the pathogenesis of S. pyogenes infection, the isogenic protease-negative mutants have been constructed by homologous recombination. Using an animal model via air pouch inoculation, we showed that these mutants caused less mortality and tissue damage than protease-positive strains. Reconstitution of SPE B in the air pouches increased the mortality rate and tissue damage of mice receiving the speB mutant strain. The role of SPE B was further confirmed by demonstrating that SPE B immunization of mice conferred protection from challenge with a lethal dose of protease-positive bacteria. A higher neutrophil influx was observed after inoculation with protease-positive strains than that with the speB mutants. However, we found a higher level of infiltrated cell death in the group treated with wild-type strain. Some of those infiltrated cells exhibited the characteristics of apoptosis. Apoptosis has been implicated in the mechanism of bacterial pathogenesis, which involves a variety of host-pathogen interactions. We adapted an in vitro system using U937 human monocytic cells to ask the question whether SPE B plays a role in the apoptosis. Treatment of U937 cells with S. pyogenes led to an induction of apoptosis in these cells. A comparison between the wild-type strain and its isogenic protease-negative mutant indicated that the production of SPE B caused a greater extent of apoptosis in U937 cells. Further study showed that purified SPE B alone could induce U937 cells to undergo apoptosis. The protease activity of SPE B was required for apoptosis to proceed, since treatment with cysteine protease inhibitor E64 or heat inactivation abrogated this death-inducing effect. The SPE B-induced apoptosis pathway was caspase family protease-dependent. Treatment with caspase-1 and caspase-3 inhibitors blocked SPE B-induced apoptosis. Further experiments showed that the phagocytic activity of U937 cells was reduced by SPE B. Treatment with E64 and heat inactivation both abrogated the phagocytosis-inhibitory effect of SPE B. Concerning the effect of SPE B on other proteins or cell surface markers, our study showed that SPE B digested other streptococcal pyrogenic exotoxins and blocked the mitogenic activity of streptococcal pyrogenic exotoxin C (SPE C). Further, SPE B can modulate CD4 and CD18 expression on MOLT-4 and U937 cells, respectively. Taken together, SPE B acts as an enhancing factor for disease progressing. SPE B causes an increase in apoptotic cell death and resistance to phagocytic activity of host cells. The multiplication of bacteria in local tissues causes tissue injury, then the bacteria can invade and disseminate into inner tissues and cause severe consequences of infection.
45
An-ChiKu and 顧安琪. "The roles of oxidative stress in group A streptococcal infection." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/x59jjm.
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Li, Shao-Hui, and 李紹暳. "Investigate the Role of M4 Streptococcal Pili in Superficial Skin Infection." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/f9wrer.
Full textAbstract:
碩士國立臺灣大學
微生物學研究所
105
Group A Streptococcus (Streptococcus pyogenes, GAS) is a severe and widespread human pathogen that cause mild diseases such as pharyngitis, impetigo as well as life-threatening necrotizing fasciitis and streptococcal septic shock syndrome. Successful colonization and invasion to host epithelial cell is a critical first step for succeeding invasive diseases. Multiple virulence factors have been reported in group A Streptococcus to strengthen its interaction with host cells, such as M protein, extracellular matrix-binding proteins and pili. Pili was a long non-covalent proteinaceous structure assembled on bacterial surface first observed in Gram-negative bacteria in 1949 and it is responsible for host cell adherence, biofilm formation, electron transport, conjugation, mobility and immunomodulation. However, functional characterization of pili in Gram-positive bacteria was just began in the past decade. The genes encoding the streptococcal pilus proteins all cluster in a highly variable pilus island, the fibronectin-binding, collagen-binding, T antigen (FCT) region, which would translate into three pilus subunits and assembly enzymes, sortase. Unlike the non-covalent linkage of pili observed in Gram-negative bacterium, pili in Gram-positive bacteria are composed of covalently linked pilins which polymerize into thin rods with various length. The previously constructed serotype M4 streptococcal mutant, M4 Δspy0116, lacks the cell wall anchor protein encoded by a gene located in the FCT region, therefore, we speculated that the formation of pili in this M4 Δspy0116 mutant should be affected. We found that the M4 streptococcal pilus subunits and sortase in the FCT region can be co-transcribed into a polycistronic mRNA. In addition, our data demonstrated that the M4 Δspy0116 mutant lacks the long flexible polymers protruding from the bacteria, and are less capable to form biofilm and to adhere to human nasal septum cells. Moreover, in the in vivo murine subcutaneous infection model, the pilus-absent mutant resulted in mild skin infection with reduced bacterium recovery in the lesion compared to the parental wild-type bacteria. In summary, our data suggest that M4 streptococcal pili play a crucial role in all steps responsible for a successful streptococcal skin infection. In the future, we will analyze whether the expression level of pilus components can be modulated during its interplaying with host cells.
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Madzivhandila, Mashudu. "Serotype, pilus island distribution and molecular epidemiology of Streptococcus agalactiae isolates from colonization and invasive disease." Thesis, 2014.
Find full textAbstract:
Background: Group B streptococcus (GBS) is a leading cause of invasive bacterial
disease in neonates. The possibility of maternal immunization with GBS-vaccines is
being explored. Vaccine candidates include serotype-specific polysaccharide-protein
conjugates and GBS surface proteins, including pilus island proteins. In this project, we
aimed to undertake capsular serotype identification, pilus island identification and
genotypic characterization of GBS isolates associated with colonization in mothernewborn
dyads and invasive disease in infants. Methods: Colonizing GBS isolates were identified by vaginal swabbing of mothers
(n=541) during active labor and from skin of their newborns post-delivery (n=395).
Invasive GBS isolates from infants (n=284) were identified through laboratory-based
surveillance. GBS serotyping was done by latex agglutination. Serologically nontypeable
isolates were typed by a serotype-specific PCR method. The pilus islands from
541 colonizing isolates and 284 invasive isolates were characterized by real-time PCR
targeting the ancillary protein 1 and 2. We undertook sequence typing based on the three
most heterogeneous genes (adhP, atr and glnA) of multilocus sequence typing (MLST)
on GBS isolates identified in young-infants with invasive disease (n=283) and those
associated with maternal (n=525) and newborn colonization at birth (n=369). A total of
121 colonizing and 131 invasive disease GBS isolates that were representative of 55 and
35 clusters respectively were analyzed by the remaining four MLST genes. The gbs2018 locus was characterized by DNA sequencing.
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Shiou-Ling, Lu, and 呂秀菱. "Anti-inflammatory and protective effects of kallistatin in group A streptococcal infection." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/83373735382141661280.
Full textAbstract:
碩士國立成功大學
微生物暨免疫學研究所
95
The group A streptococcus (GAS) causes a variety of diseases, ranging from mild self-limiting infection to severe life-threatening infection, such as pharyngitis, tonsillitis, and tympanitis to necrotizing fasciitis, bacteremia, and streptococcus toxic shock syndrome (STSS). The disease severity may be associated with the different bacterial serotype or depend on patient’s healthy condition. Previous clinical findings indicated that patients with sepsis had lower level of kallistatin protein. Kallistatin was originally found to be a tissue kallikrein-binding protein. But recent studies have shown that kallistatin may function independently of its interaction with tissue kallikrein. Kallistatin has some biological effects, such as anti-angiogenesis, anti-inflammation, and anti-oxidation and possesses beneficial effects in hypertensive, cardiovascular and renal diseases. However, the effects of kallistatin in microbial infection have not been explored. In this study, we transiently overexpressed kallistatin gene by hydrodynamic injection and investigated the protective effects of kallistatin in a mouse model of GAS infection. We found that kallistatin increased the survival rate of GAS-infected mice. The bacterial numbers and the inflammatory cytokines and chemokines in the local infection site and blood were lower in kallistatin-treated group than those in control groups. In contrast with control mice, kallistatin-treatment decreased neutrophil infiltration into the local infection site, while promoting neutrophil viability. In the histological analysis, the skin and liver tissue showed less damage after treatment with kallistatin compared to the control groups. Consequently, we will examine the biological function and therapeutic effect of kallistatin in GAS-infected mice.
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Lin, Hsiu Yueh, and 林秀月. "Group A streptococcal infection in a mouse model: role of SPE B." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/95326013936828972200.
Full textAbstract:
碩士國立成功大學
微生物暨免疫學研究所
87
Abstract Group A streptococci (GAS) streptococcus pyogenes causes a broad spectrum of diseases. Clinical features that result in life-threatening sequelae include necrotizing fasciitis and streptococcal toxic shock syndrome. However, so far, their pathogenic factors are poorly defined. Accumulated evidence suggests that streptococcal pyrogenic exotoxin B (SPE B) may be a critical virulent factor in invasive GAS infections. The gene of SPE B is found in all strains of GAS, and the encoded protein functions as a cysteine protease. In order to study the role that SPE B may play in the pathogenesis of GAS infection, the isogenic protease-negative mutants were previously constructed by homologous recombination. The common primary focuses of the severe GAS infections are infections of the skin and soft tissue (necrotizing fasciitis or myositis). We have adopted skin air sac as the route of bacterial infection for studying the role of SPE B in the mouse model of GAS infection. Previous studies in our laboratory indicated that these mutants caused less mortality and tissue damage than protease-positive strains. The role of SPE B was further confirmed by demonstrating that SPE B immunization of mice conferred protection from challenge with a lethal dose of protease-positive bacteria. To further explore the correlation of SPE B with the process of GAS diseases, the systemic effects by local infection were investigated in this study. We found that bacterial numbers in the exudates from the air pouches of mice infected with the wild-type strains were increased by the time, but not seen in mice infected with the speB mutants. The frequency of mice infected with the wild-type strains developed bacteremia was higher than that of mice infected with the speB mutants. Further, to observe whether the multiple organs were affected, the histopathologic changes of various organs were examined. We found severe tissue destruction in kidney and liver. Histopathologic changes in kidney and liver occurred at 24 h after bacteria inoculation, and the wild-type strains caused a higher severity compared to those of the speB mutants. The elevation of biochemical components (AST﹑ALT and BUN) levels in sera was correlated with liver and renal impairment, and the levels were higher in sera from mice infected with the wild-type strains than those from mice infected with the speB mutants. The histopathologic changes were not observed in brain and lung. The organ weights of spleen from mice infected with the wild-type strains were reduced at 48 h, but not seen in mice infected with the speB mutants. The increase of SPE B level in inoculation site and serum was detected with competition ELISA. In addition, the direct effects of SPE B in mice via intraperitoneal injection were studied using the recombinant wild-type SPE B and its mutant C192S. The results indicated that wild-type SPE B but not C192S caused local tissue damage and death in the animal. Taken together, a correlation of SPE B with bacteriologic and histopathologic changes is demonstrated in this study.
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Miao-HueiCheng and 鄭妙慧. "Study on the protective mechanisms of dextromethorphan in group A streptococcal infection." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/74512896002706002600.
Full textAbstract:
碩士國立成功大學
微生物及免疫學研究所
101
Group A streptococcus (GAS) is an important human pathogen that causes a wide spectrum of diseases, ranging from relatively mild infections such as pharyngitis and impetigo, to life-threatening invasive diseases, including necrotizing fasciitis and streptococcal toxic shock syndrome. Dextromethorphan (DM) is an over-the-counter antitussive. In addition, it has been identified as an anti-inflammatory agent. Recent studies indicate that DM has neuroprotective activity by inhibiting NADPH oxidase activity which leads to the reduction of reactive oxygen species (ROS). Our previous studies showed that DM treatment reduced inflammatory responses which contributed to an increased survival rate of GAS-infected mice. We used in vitro systems to further investigate the mechanisms underlying DM-mediated attenuation of inflammation in GAS-infected macrophages. Our results showed that DM treatment reduced Akt/GSK-3β/NF-κB signaling pathway activation, and also led to down-regulation of iNOS expression and NO production by inhibiting the membrane translocation of NADPH oxidase subunit p47phox in GAS-infected macrophages. In addition, DM can significantly decrease ROS production in GAS-infected macrophages. Taken together, DM can reduce GAS infection-induced overactive inflammation by inhibiting NADPH oxidase-mediated ROS production, which leads to down-regulation of the Akt/GSK-3β/NF-κB/iNOS/NO signaling pathway.