Relevant bibliographies by topics / S. agalactiae

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Academic literature on the topic 'S. agalactiae'

Author: Grafiati
Published: 4 June 2021
Last updated: 13 February 2022

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Journal articles on the topic "S. agalactiae"

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Hardi, Esti Handayani, Sukenda Sukenda, Enang Harris, and Angela Mariana Lusiastuti. "Toksisitas Produk Ekstrasellular (ECP) Streptococcus agalactiae pada Ikan Nila (Oreochromis niloticus)." Jurnal Natur Indonesia 13, no. 3 (October 21, 2012): 187. http://dx.doi.org/10.31258/jnat.13.3.187-199.

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This research aimed to know the toxicity of extracellular products (ECP) of Streptococcus agalactiae was tastedin cultured Nile tilapia (Oreochromis niloticus). Streptococcus agalactiae had two haemolytic types: β-haemolyticand non-haemolytic type. Toxicity test of ECP to know the virulancy factor of S. agalactiae was still limited. It wasfound that after tested on 15 fish weighing 15 g through intraperitoneal injection 0,1 ml/fish, both bacteria causedchanges in swimming pattern, palatability, external and internal anatomy macroscopically and microscopically.Extracellular products of S. agalactiae non-haemolytic type (BHIA and BHI 24 h) and β-haemolytic type (BHI 72 h)caused mortality 12 hours after injection and the mortality continued till day 7 th of culture. Whirling happened 96hours after injection with ECP S. agalactiae β-haemolytic type (BHIA 72 h incubation) whereas injection with ECP(BHI 24 h) on 72 h after injection and continued untill day 7 th. Behavior disease signs caused by S. agalactiaeoccured on eyes. There were opacity, purulens, eye shrink, lateral and bilateral exopthalmia and haemorrhage oninfected-fish. Silver staining of sodium dodecyl sulphate-polyacrylamide gels to S. agalactiae revealed thatpredominant 51.8-69.6 kDa bands were present in BHIA ECP fraction. The 69.6 kDa was absent from the BHI ECP.Total protein on non-haemolytic S. agalactiae ECP are 28.18 ppm on BHIA medium and 13.64 ppm on BHI medium.Whereas β-haemolytic S. agalactiae ECP are 2.73 ppm on BHIA medium and 8.18 ppm on BHI medium. Concentrationof protein in ECP was one of factor that caused non-haemolytic S. agalactiae more virulent than β-haemolytic type.The conclusion from the research that ECP was virulent factor on β-haemolytic and non-haemolytic S. agalactiaein fish which caused changes in behavior disease signs.
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Febrianti, Rita, Taukhid Taukhid, and Angela Mariana Lusiastuti. "KERENTANAN IKAN NILA SULTANA, RED NIFI, SRIKANDI DAN AUREUS TERHADAP INFEKSI BAKTERI Streptococcus agalactiae." Jurnal Riset Akuakultur 10, no. 2 (June 30, 2015): 221. http://dx.doi.org/10.15578/jra.10.2.2015.221-230.

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Penelitian ini bertujuan untuk menguji kerentanan empat strain ikan nila, yaitu: Sultana, Red NIFI, Srikandi, dan Aureus terhadap infeksi bakteri Streptococcus agalactiae. Ikan uji berukuran 15-20 g/ekor dan berasal dari populasi, serta batch umur yang sama. Infeksi bakteri S. agalactiae dilakukan secara buatan melalui penyuntikan intra peritoneal (IP) pada dosis 104 cfu/mL, sedangkan kelompok kontrol diinjeksi dengan larutan Phosphate Buffered Saline (PBS). Pengamatan dilakukan terhadap gejala klinis dan mortalitas ikan uji yang berlangsung selama 14 hari. Hasil penelitian menunjukkan bahwa seluruh strain ikan nila mengalami respons yang sama terhadap infeksi bakteri S. agalactie yang ditandai dengan munculnya gejala klinis seperti: warna gelap/menghitam, sirip geripis, nekrosa pada mulut, mata menonjol, opaque, ulcer, dan dropsy. Kerentanan tertinggi terhadap infeksi bakteri S. agalactiae yang dimanifestasikan dengan rataan persentase mortalitas ikan uji diperoleh pada ikan nila Aureus sebesar 72%, Sultana 50%, Srikandi 36%, Red NIFI sebesar 24%, dan kontrol tidak ada mortalitas. Setelah diuji tantang, kadar limfosit mengalami kenaikan, netrofil dan monosit mengalami penurunan.
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Samen, Ulrike, Birgit Gottschalk, Bernhard J. Eikmanns, and Dieter J. Reinscheid. "Relevance of Peptide Uptake Systems to the Physiology and Virulence of Streptococcus agalactiae." Journal of Bacteriology 186, no. 5 (March 1, 2004): 1398–408. http://dx.doi.org/10.1128/jb.186.5.1398-1408.2004.

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ABSTRACT Streptococcus agalactiae is a major cause of invasive infections in human newborns. To satisfy its growth requirements, S. agalactiae takes up 9 of the 20 proteinogenic amino acids from the environment. Defined S. agalactiae mutants in one or several of four putative peptide permease systems were constructed and tested for peptide uptake, growth in various media, and expression of virulence traits. Oligopeptide uptake by S. agalactiae was shown to be mediated by the ABC transporter OppA1-F, which possesses two substrate-binding proteins (OppA1 and OppA2) with overlapping substrate specificities. Dipeptides were found to be taken up in parallel by the oligopeptide permease OppA1-F, by the dipeptide ABC transporter DppA-E, and by the dipeptide symporter DpsA. Reverse transcription-PCR analysis revealed a polycistronic organization of the genes oppA1-F and dppA-E and a monocistronic organization of dpsA in S. agalactiae. The results of quantitative real-time PCR revealed a medium-dependent expression of the operons dppA-E and oppA1-F in S. agalactiae. Growth of S. agalactiae in human amniotic fluid was shown to require an intact dpsA gene, indicating an important role of DpsA during the infection of the amniotic cavity by S. agalactiae. Deletion of the oppB gene reduced the adherence of S. agalactiae to epithelial cells by 26%, impaired its adherence to fibrinogen and fibronectin by 42 and 33%, respectively, and caused a 35% reduction in expression of the fbsA gene, which encodes a fibrinogen-binding protein in S. agalactiae. These data indicate that the oligopeptide permease is involved in modulating virulence traits and virulence gene expression in S. agalactiae.
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Hassan, Abdulwahed A., Amir Abdulmawjood, Ali Ö. Yildirim, Kristin Fink, Christoph Lämmler, and Reglindis Schlenstedt. "Identification of streptococci isolated from various sources by determination ofcfbgene and other CAMP-factor genes." Canadian Journal of Microbiology 46, no. 10 (October 1, 2000): 946–51. http://dx.doi.org/10.1139/w00-078.

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In the present study, the CAMP-factor (cfb) gene of streptococci of serological group B (Streptococcus agalactiae) and the CAMP-factor (cfu) gene of S. uberis could be amplified by polymerase chain reaction. A cfb specific amplicon could be observed for all 128 phenotypically CAMP-positive S. agalactiae, for the phenotypically CAMP-negative S. agalactiae strain 74-360, and for 2 S. difficile reference strains. A cfu specific amplicon could be observed for all 7 phenotypically CAMP-positive S. uberis. Four S. agalactiae strains isolated from 4 cows with mastitis appeared to be phenotypically CAMP-negative and negative in the cfb gene PCR. The CAMP-positive and CAMP-negative isolates, including both S. difficile, could be identified as S. agalactiae by amplification of a S. agalactiae specific part of the V2 region of the 16S rRNA and a species-specific part of the 16S-23S rRNA intergenic spacer region. Amplification of an internal fragment of the cfb gene with a reduced annealing temperature yielded positive reactions not only for CAMP-positive S. agalactiae, but also for phenotypically CAMP-positive S. pyogenes (n = 4), S. canis (n = 28), and S. uberis (n = 7), indicating a close relation of the CAMP genes of these 4 species. The relation could be further demonstrated by sequencing the internal fragment of the CAMP-factor (cfg) gene of S. canis and comparing the sequence with those of S. agalactiae, S. pyogenes, and S. uberis.Key words: CAMP factor, cfb, cfu, S. canis.
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Dashtizade, Mina, Mohammad Reza Zolfaghari, Masoud Yousefi, and Ali Nazari-Alam. "Antibiotic Susceptibility Patterns and Prevalence of Streptococcus Agalactiae Rectovaginal Colonization Among Pregnant Women in Iran." Revista Brasileira de Ginecologia e Obstetrícia / RBGO Gynecology and Obstetrics 42, no. 08 (June 19, 2020): 454–59. http://dx.doi.org/10.1055/s-0040-1710299.

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Abstract Objective Streptococcus agalactiae is an important pathogen in neonates and pregnant women. Neonatal invasive infections due to S. agalactiae are life-threatening and preventive strategies for this challenge of human have become a concern. The aim of the present study was to determine the prevalence of rectovaginal colonization, related risk factors and antibiotic resistance pattern of S. agalactiae among pregnant women in Iran. Methods The present study was performed on 240 pregnant women. Vaginal and rectal swabs were obtained from all of the women and then were transferred to the laboratory. The isolation and identification of S. agalactiae was performed by standard microbiological tests and polymerase chain reaction (PCR) assay. The antimicrobial susceptibility patterns of the isolates were determined by the Kirby-Bauer disk diffusion. Polymerase chain reaction was used to detect ermB and mefA genes in erythromycin-nonsusceptible isolates. Results Out of 240 pregnant women, 16 cases (6.7%) were colonized by S. agalactiae. There is no significant association between demographic-obstetric factors and maternal S. agalactiae colonization in the pregnant women. Linezolid, vancomycin and ampicillin were the most effective antibiotics against S. agalactiae. The ermB gene was present in 6 (35.29%) S. agalactiae isolates. However, the mefA gene was not detected in any of the isolates. Conclusion Given the relatively significant prevalence of S. agalactiae colonization in the pregnant women in the present study and the risk of serious neonatal infections, the screening of pregnant mothers for the bacteria seems necessary. Our findings highlight the importance of appropriate antibiotic prophylaxis during pregnancy for the prevention of early onset S. agalactiae-neonatal infection and comorbidity.
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Pietrocola, Giampiero, Axel Schubert, Livia Visai, Mauro Torti, J. Ross Fitzgerald, Timothy J. Foster, Dieter J. Reinscheid, and Pietro Speziale. "FbsA, a fibrinogen-binding protein from Streptococcus agalactiae, mediates platelet aggregation." Blood 105, no. 3 (February 1, 2005): 1052–59. http://dx.doi.org/10.1182/blood-2004-06-2149.

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AbstractThe bacterium Streptococcus agalactiae is an etiologic agent in the pathogenesis of endocarditis in humans. FbsA, a fibrinogen-binding protein produced by this pathogen, is considered an important virulence factor. In the present study we provide evidence that S agalactiae clinical isolates bearing FbsA attach to fibrinogen and elicit a fibrinogen-dependent aggregation of platelets. Mutants of S agalactiae lacking the fbsA gene lost the ability to attach to fibrinogen and to aggregate platelets. Plasmid-mediated expression of fbsA restored the capability for fibrinogen binding and platelet aggregation in S agalactiae fbsA mutants, and allowed Lactococcus lactis to interact with fibrinogen and to aggregate human platelets. Moreover, a monoclonal anti-FbsA antibody inhibited bacterial adherence to fibrinogen and S agalactiae–induced platelet aggregation. Platelet aggregation was inhibited by aspirin, prostaglandin E1, the peptide RGDS, and the antibody abciximab, demonstrating the specificity of platelet aggregation by S agalactiae and indicating an involvement of integrin glycoprotein IIb/IIIa in the induction of platelet aggregation. Aggregation was also dependent on anti-FbsA IgG and could be inhibited by an antibody against the platelet FcγRIIA receptor. These findings indicate that FbsA is a crucial factor in S agalactiae–induced platelet aggregation and may therefore play an important role in S agalactiae–induced endocarditis.
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Trigo, Gabriela, Paula Ferreira, Niza Ribeiro, Márcia Dinis, Elva Bonifácio Andrade, José Melo-Cristino, Mário Ramirez, and Delfina Tavares. "Identification of immunoreactive extracellular proteins of Streptococcus agalactiae in bovine mastitis." Canadian Journal of Microbiology 54, no. 11 (November 2008): 899–905. http://dx.doi.org/10.1139/w08-083.

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Streptococcus agalactiae is a common pathogen that causes bovine mastitis. The aims of this study were to evaluate the antibody response against S. agalactiae extracellular proteins in the whey and serum of naturally infected bovines and to identify possible immunodominant extracellular antigens. IgG1 antibodies against S. agalactiae extracellular proteins were elevated in the whey and serum of naturally infected bovines. In the whey, the levels of IgG1 specific for S. agalactiae extracellular proteins were similar in infected and noninfected milk quarters from the same cow, and the production of antibodies specific for S. agalactiae extracellular proteins was induced only by infection with this bacterium. The immunoreactivity of extracellular proteins with bovine whey was clearly different in infected versus control animals. Group B protective surface protein and 5′-nucleotidase family protein were 2 major immunoreactive proteins that were detected only in the whey of infected cows, suggesting that these proteins may be important in the pathogenesis of S. agalactiae-induced mastitis. This information could be used to diagnose S. agalactiae infection. In addition, these antigens may be useful as carrier proteins for serotype-specific polysaccharides in conjugate vaccines.
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Gutekunst, Heike, Bernhard J. Eikmanns, and Dieter J. Reinscheid. "Analysis of RogB-Controlled Virulence Mechanisms and Gene Expression in Streptococcus agalactiae." Infection and Immunity 71, no. 9 (September 2003): 5056–64. http://dx.doi.org/10.1128/iai.71.9.5056-5064.2003.

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ABSTRACT Streptococcus agalactiae is the leading cause of bacterial sepsis and meningitis in neonates and also the causative agent of different serious infections in immunocompromised adults. The wide range of diseases that are caused by S. agalactiae suggests regulatory mechanisms that control the formation of specific virulence factors in these bacteria. The present study describes a gene from S. agalactiae, designated rogB, encoding a protein with significant similarity to members of the RofA-like protein (RALP) family of transcriptional regulators. Disruption of the rogB gene in the genome of S. agalactiae resulted in mutant strain RGB1, which was impaired in its ability to bind to fibrinogen and fibronectin. Mutant RGB1 also exhibited a reduced adherence to human epithelial cells but did not show an altered invasion of eukaryotic cells. By real-time PCR analysis, mutant RGB1 revealed an increased expression of the cpsA gene, encoding a regulator of capsule gene expression. However, strain RGB1 exhibited a reduced expression of the rogB gene and of two adjacent genes, encoding putative virulence factors in S. agalactiae. Furthermore, mutant RGB1 was impaired in the expression of the fbsA gene, coding for a fibrinogen receptor from S. agalactiae. The altered gene expression in mutant RGB1 could be restored by plasmid-mediated expression of rogB, confirming a RogB deficiency as the cause for the observed changes in virulence gene expression in S. agalactiae. Reporter gene studies with a promotorless luciferase gene fused to fbsA allowed a growth-dependent analysis of fbsA expression in S. agalactiae. These reporter gene studies also suggest that RogB exerts a positive effect on fbsA expression in S. agalactiae.
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Kawamura, Yoshiaki, Yoko Itoh, Noriko Mishima, Kiyufumi Ohkusu, Hiroaki Kasai, and Takayuki Ezaki. "High genetic similarity of Streptococcus agalactiae and Streptococcus difficilis: S. difficilis Eldar et al. 1995 is a later synonym of S. agalactiae Lehmann and Neumann 1896 (Approved Lists 1980)." International Journal of Systematic and Evolutionary Microbiology 55, no. 2 (March 1, 2005): 961–65. http://dx.doi.org/10.1099/ijs.0.63403-0.

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The genetic relationship between Streptococcus agalactiae and Streptococcus difficilis was studied. S. difficilis was originally described as serologically non-typable but was later reported to be a group B, type Ib streptococcus. Upon comparative analysis of five gene sequences, it was found that S. agalactiae and S. difficilis are closely related. Sequence similarity values between these two species were 100·0 % for 16S rRNA, 99·6 % for gyrB, 98·6 % for sodA, 99·5 % for gyrA and 99·8 % for parC genes. These data strongly suggest that S. agalactiae and S. difficilis are synonyms. The biochemical characteristics of S. difficilis, which differ slightly from those of typical S. agalactiae, are similar to those of other group B, type Ib streptococci isolated from fish and frogs. Whole genome DNA–DNA hybridization values between the type strains of both species were greater than 78·6 %. On the basis of these data, it is proposed that S. difficilis is a later synonym of S. agalactiae.
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De Gregorio, Priscilla Romina, María Silvina Juárez Tomás, María Cecilia Leccese Terraf, and María Elena Fátima Nader-Macías. "In vitro and in vivo effects of beneficial vaginal lactobacilli on pathogens responsible for urogenital tract infections." Journal of Medical Microbiology 63, no. 5 (May 1, 2014): 685–96. http://dx.doi.org/10.1099/jmm.0.069401-0.

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The aim of this work was to evaluate the effects of beneficial human vaginal lactobacilli (Lb) on urogenital pathogens through in vitro and in vivo experiments. Co-aggregative and antimicrobial properties between five vaginal Lb strains and urogenital pathogens or potential pathogens (Streptococcus agalactiae, Staphylococcus aureus and Candida albicans strains) were assayed. Also, associative cultures of Lb strains and S. agalactiae were performed and bacterial growth, pH, lactic acid and hydrogen peroxide (H2O2) were determined at different times. Based on the results obtained, the in vivo studies were assayed in mice with Lactobacillus gasseri CRL 1509 or Lactobacillus salivarius CRL 1328 inoculated intravaginally (i.v.) and then challenged i.v. with S. agalactiae. Results were analysed by ANOVA (repeated measures and general linear models). Most of the Lb strains increased the percentage of aggregation of S. agalactiae strains. Only one strain (Lactobacillus reuteri CRL 1324) positively affected the aggregation of S. aureus and none increased the aggregation of C. albicans. The inhibition of the growth of S. agalactiae strains by production of organic acids by lactobacilli was evidenced. The Lb–S. agalactiae co-cultures showed a significant inhibition of the pathogen after 4 h and 8 h of incubation. Parallel increases in lactic acid and H2O2 levels were observed. However, in the experimental murine model, no significant differences were obtained in the number of streptococci recovered from the vaginal tract of control mice and those inoculated with Lb. In conclusion, vaginal Lb exhibited in vitro co-aggregative and antimicrobial effects on S. agalactiae strains, suggesting that they could be promising candidates for protection against S. agalactiae challenge. However, as these effects were not evidenced in the murine model used, further animal studies under different experimental conditions should be conducted to evaluate the preventive effect of Lb against challenge with S. agalactiae.
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Dissertations / Theses on the topic "S. agalactiae"

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Lütke, Volksbeck Urban. "Antibiotikaresistenz von S. agalactiae Molekulargenetische Grundlagen, Sero- und Genotypisierung." [S.l. : s.n.], 2006.

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Konto-Ghiorghi, Yoan. "Biosynthèse, régulation et rôle(s) du pilus chez Streptococcus agalactiae." Paris 6, 2009. http://www.theses.fr/2009PA066274.

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Schubert, Axel Georg [Verfasser]. "Identifizierung des fbsA-Gens aus S. agalactiae und Untersuchungen zur Bedeutung von FbsA für dieVirulenz der Bakterien / Axel Schubert." Ulm : Universität Ulm. Fakultät für Naturwissenschaften, 2005. http://d-nb.info/1015471692/34.

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Szili, Noémi Réka. "Biosynthesis, role(s) and regulation of the PI-2b pilus in the hypervirulent ST-17 clone of Streptococcus agalactiae." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC062/document.

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Streptococcus agalactiae (Streptocoque du Groupe B, SGB) est une bactérie pathogène opportuniste à Gram-positif responsable principalement d’infections néonatales. Les études épidémiologiques ont montré que les souches appartenant au complexe clonal 17 (ST-17) sont responsables de 80% des cas de méningites tardives. La génomique comparative a permis de mettre en évidence des gènes codant pour des protéines de surface spécifiques au clone ST-17 comme les adhésines Srr2 et HvgA. On y trouve également un locus codant pour un pilus spécifique appelé PI-2b, qui constitua l’objet principal de cette thèse. Ce locus PI-2b est ubiquitaire dans les souches ST-17, mais on le retrouve également dans quelques souches humaines non-ST-17 comme la souche A909 ainsi que dans les souches bovines. Dans la première partie de ce travail, nous avons comparé l’expression du pilus PI-2b dans les souches ST-17 versus non-ST-17. L’expression du locus PI-2b, bien que variable au sein du complexe ST-17, est plus faible que dans les souches non-ST-17. Dans la souche représentative du ST-17 BM110, l’expression du gène spb1codant pour la piline majeure est 4-6 fois plus faible que dans la souche A909. Nous avons montré que cet effet est dû à la présence d’une séquence de 43 paires de base en amont du locus PI-2b, formant une structure de type tige-boucle, qui empêche la transcription provenant du locus situé en amont codant pour l’antigène B. Grâce à des expériences de fusion transcriptionnelle avec un gène rapporteur codant pour la GFP, nous avons montré qu’une région étendue du promoteur ainsi que des facteurs spécifiques à S. agalactiae sont nécessaires pour l’expression maximale du locus PI-2b. Le niveau maximal de transcription du pilus PI-2b est observé à 37 °C. L’ensemble de nos résultats suggère une régulation complexe de l’expression du locus PI-2b, dont l’expression plus faible dans les souches ST-17, pourrait conférer aux bactéries la capacité d’échapper au système immunitaire de l’hôte et de disséminer plus efficacement. La deuxième partie de ce travail a porté sur le rôle des gènes orf, lep et san1519 dont la fonction sur la biosynthèse du pilus n’était pas connue. Nous avons montré que les gènes orf et lep sont importants pour l’expression et la polymérisation du pilus PI-2b. Nous avons montré que lep code pour une signal peptidase fonctionnelle qui participe à la maturation de la piline majeure. Quant à orf, nos autres résultats ainsi le chevauchement traductionnel entre ce gène et lep, conservé dans d’autres espèces de streptocoques, suggèrent un rôle dans la stabilisation des ARNm
Streptococcus agalactiae (also known as Group B Streptococcus, GBS) is an opportunistic Gram-positive pathogen responsible for severe invasive infections, especially in neonates. GBS strains belonging to the ST-17 sequence type are responsible for 80% of late-onset neonatal meningitis. Genomic comparison of ST-17 strains to non-ST-17 GBS isolates revealed a few surface proteins that are characteristic of ST-17 clone, such as HvgA and Srr2, which contribute to colonization and dissemination. Similarly, the PI-2b type pilus is conserved in ST-17 strains and the main goal of this PhD project was to decipher the role of this pilus in the physiopathology of ST-17 strains. In the first part of this work, we compared the expression of the PI-2b pilus in our ST-17 representative strain BM110, and a non-ST-17 human clinical isolate, A909. We showed that PI-2b expression, although variable, was lower in ST-17 isolates as compared to non ST17 isolates. In the representative strain BM110, we demonstrated that the lower expression was be due to the presence of a 43-base pair (bp) hairpin-like structure in the upstream region of PI-2b, preventing read-through transcription from upstream antigen B (AgB) operon. Furthermore, gene reporter assays to characterize the Ppi-2b promoter region revealed the requirement of an extended 5’ region and of GBS-specific regulatory factors to drive PI-2b transcription. PI-2b transcription was shown to be maximal at 37 °C. Collectively our results suggest a complex regulation of PI-2b expression in ST-17 clinical isolates, that may confer a selective advantage in the human host either by reducing host immune responses and/or increasing their dissemination potential.In the second part of this work, we sought to investigate the role of the putative adhesin AP1-2b, and the two accessory genes lep and orf in the biosynthesis of PI-2b pilus. We showed that both orf and lep are important for PI-2b expression. Our results suggest that Lep is a functional signal peptidase involved in the optimal processing of the major PI-2b pilin. The role of orf remains to be uncovered
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Gianoli, Nicola. "Identification de streptocoques autres que S. agalactiae issus de mammites bovines et mesure de leur concentration minimale inhibitrice pour huit antibiotiques /." [S.l.] : [s.n.], 1990. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.

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Spoerry, Christian. "Streptococcal immunoglobulin degrading enzymes of the IdeS and IgdE family." Doctoral thesis, Umeå universitet, Institutionen för molekylärbiologi (Medicinska fakulteten), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-134552.

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Bacteria of the genus Streptococcus are common asymptomatic colonisers of humans and animals. As opportunistic pathogens they can however, depending on their host’s immune status and other circumstances, cause mild to very severe infections. Streptococci are highly intertwined with specific host species, but can also cause zoonosis or anthroponosis in more uncommon hosts. Prolonged and reoccurring infections require immune evasion strategies to circumvent detection and eradication by the host’s immune defence. A substantial part of the immune defence against bacterial pathogens is mediated by immunoglobulins. This thesis is based on work to identify and characterise immunoglobulin degrading enzymes secreted by different Streptococcus species as a means to sabotage and evade antibody-mediated immune responses. Stoichiometric and kinetic analysis of the IgG degrading enzyme IdeS from the important human pathogen S. pyogenes revealed that IdeS cleaves IgG, opposed to previous publications, as a monomer following classical Michaelis-Menten kinetics. The IdeS homologue of S. suis, IdeSsuis, did however not cleave IgG, but was highly specific fo rporcine IgM. S. suis was found to possess yet another protease, IgdE, capable of cleaving porcine IgG. Both of these proteases were shown to promote increased bacterial survival in porcine blood during certain conditions. IgdE is the founding member of a novel cysteine protease family (C113). Novel streptococcal members of this protease family were shown to specifically degrade certain IgG subtypes of the respective Streptococcus species’ main host. The observed substrate specificity of IgdE family proteases reflects the host tropism of these Streptococcus species, thereby giving insights into host-pathogen co-evolution. The abundance of immunoglobulin degrading enzymes among Streptococcus species indicates the importance of evasion from the antibody mediated immune responses for streptococci. These novel identified immunoglobulin degrading enzymes of the IdeS and IgdE protease families are potential valid vaccine targets and could also be of biotechnological use.
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Lütke, Volksbeck Urban [Verfasser]. "Antibiotikaresistenz von S. agalactiae : molekulargenetische Grundlagen, Sero- und Genotypisierung / vorgelegt von Urban Lütke Volksbeck, geb. Müller." 2007. http://d-nb.info/98311885X/34.

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Conference papers on the topic "S. agalactiae"

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Pinto, Vanessa Arantes, Gabriela Santos Alencar, Adriano Favero, Hugo Franciscon, and Fagner Luiz Da Costa Freitas. "POTENCIAL MICROBIOLÓGICO DO SYZYGIUM AROMATICUM (L). SOBRE MICRORGANISMOS DE IMPORTÂNCIA NA MEDICINA VETERINÁRIA." In I Congresso On-line Nacional de Clínica Veterinária de Pequenos Animais. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1920.

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Introdução: O fenômeno de resistência a antimicrobianos está se mostrando um grande problema na saúde, ameaçando tanto a população humana como animal. Devido a isso, a descoberta de novos compostos com capacidade antimicrobiana torna-se imprescindível, e os fitoterápicos têm se mostrado uma alternativa promissora na terapia complementar. O óleo essencial (OE) de Syzygium aromaticum (Cravo da Índia), apresenta potencial capacidade antibacteriana e antifúngica devido às altas concentrações de Eugenol. Objetivos: Avaliar o potencial antimicrobiano do óleo essencial de Syzygium aromaticum (L). contra microrganismos de importância na Medicina veterinária. Materiais e métodos: Foram testadas as bactérias gram positivas: S. aureus LB 25923, S. aureus B24, S. aureus NP 38, Streptococcus uberis, S. agalactiae, Enterococcus faecalis e S. epidermidis; as gram negativas: Pseudomonas aeruginosa ATCC 27853 e E. coli ATCC 25922; e os fungos: C. tropicalis e C. gattii 179. Utilizou-se a técnica de disco difusão (Kirby-bauer) aplicando 10µL de OE, e posteriormente, para os patógenos que apresentaram o halo inibitório, determinou-se, aplicando 15µL de OE, a concentração inibitória mínima (CIM), concentração bactericida mínima (CBM) e concentração fungicida mínima (CFM) através da microdiluição seriada utilizando leitor de ELISA e corante resazurina. Resultados: Todos os microrganismos apresentaram halo inibitório. Com relação aos valores de CIM e CBM para as bactérias, obteve-se, respectivamente: S. aureus LB25923 (18,75% e 18,75%), S. aureus B 24 (4,94% e 4,94%) S. aureus NP 38 (3,64% e 3,64%) Streptococcus uberis (2,60% e 3,125%) S. agalactiae (5,20 %, 5,20%), Enterococcus faecalis (5,20% e 6,25%), S. epidermidis (3,38% e 4,42%), Pseudomonas aeruginosa ATCC 27853 (2,09% e 2,09%), E. coli ATCC 25922 (10,41% e 10,41%). Os resultados de CIM e CFM obtidos para os fungos foram respectivamente: C. tropicalis (1,82% e 1,82%) e C. gattii 179 (5,27% e 5,27%). Conclusão: O óleo essencial de Syzygium aromaticum possui considerável potencial antimicrobiano “in vitro”, e dessa forma, pode ser considerado uma possível alternativa para as terapias sintéticas de tratamento das doenças infecciosas bacterianas e fúngicas encontradas na rotina clínica.
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Aguiar, Edgar L., Gustavo H. M. Mendonça, Claudia B. Assunção, Sandro R. Dias, and Thiago S. Rodrigues. "Desenvolvimento de Bactérias Artificiais Mutantes de S. agalactiae Híbridas entre Humano e Tilápia Usando Algoritmo Evolucionário e Lógica Fuzzy." In CNMAC 2019 - XXXIX Congresso Nacional de Matemática Aplicada e Computacional. SBMAC, 2020. http://dx.doi.org/10.5540/03.2020.007.01.0368.

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Groiss, C., W. Ernst, K. Entleutner, and B. Seelbach-Göbel. "Einfluss der immunologischen Vorgänge während einer natürlichen Geburt auf neonatale und maternale Monozyten die mit Escherichia coli und Streptococcus agalactiae stimuliert werden." In 28. Deutscher Kongress für Perinatale Medizin. Georg Thieme Verlag KG, 2017. http://dx.doi.org/10.1055/s-0037-1607796.

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Oliveira, Marcelio, Marilza Correa, Maria Leal, Barbara Silva, and Ellen Jessouroun. "Preliminary studies of reactions using colominic and sialic acids as prototypes to bivalent vaccine against S. agalactiae and A. baumannii." In IV International Symposium on Immunobiologicals & VII Seminário Anual Científico e Tecnológico. Instituto de Tecnologia em Imunobiológicos, 2019. http://dx.doi.org/10.35259/isi.sact.2019_32596.

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