Characterization of virulence factors, antimicrobial resistance pattern and clonal complexes of group B streptococci isolated from neonates

2016 ◽  
Vol 99 ◽  
pp. 119-122 ◽  
Author(s):  
Mohammad Emaneini ◽  
Fereshteh Jabalameli ◽  
Akbar Mirsalehian ◽  
Amir Ghasemi ◽  
Reza Beigverdi
Keyword(s):  
Antimicrobial Resistance ◽  
Virulence Factors ◽  
Resistance Pattern ◽  
Group B Streptococci ◽  
Group B

scholarly journals Correlation between Group B Streptococcal Genotypes, Their Antimicrobial Resistance Profiles, and Virulence Genes among Pregnant Women in Lebanon

2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
Antoine Hannoun ◽  
Marwa Shehab ◽  
Marie-Therese Khairallah ◽  
Ahmad Sabra ◽  
Roland Abi-Rached ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Pregnant Women ◽  
Virulence Factors ◽  
Dna Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Group B Streptococci ◽  
Near Term ◽  
Group B ◽  
Susceptibility Profiles ◽  
Encoding Genes

The antimicrobial susceptibility profiles of 76Streptococcus agalactiae(Group B Streptococci [GBS]) isolates from vaginal specimens of pregnant women near term were correlated to their genotypes generated by Random Amplified Polymorphic DNA analysis and their virulence factors encoding genescylE, lmb, scpB, rib, andbcaby PCR. Based on the distribution of the susceptibility patterns, six profiles were generated. RAPD analysis detected 7 clusters of genotypes. ThecylEgene was present in 99% of the isolates, thelmbin 96%,scpBin 94.7%,ribin 33%, andbcain 56.5% of isolates. The isolates demonstrated a significant correlation between antimicrobial resistance and genotype clusters denoting the distribution of particular clones with different antimicrobial resistance profiles, entailing the practice of caution in therapeutic options. All virulence factors encoding genes were detected in all seven genotypic clusters withribandbcanot coexisting in the same genome.

scholarly journals Trends in molecular characteristics and antimicrobial resistance of group B streptococci: a multicenter study in Serbia, 2015–2020

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dusan Kekic ◽  
Ina Gajic ◽  
Natasa Opavski ◽  
Milan Kojic ◽  
Goran Vukotic ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Late Onset ◽  
Group B Streptococcus ◽  
Neonatal Morbidity ◽  
Disease Rate ◽  
Molecular Characteristics ◽  
Group B Streptococci ◽  
Live Births ◽  
Invasive Infections ◽  
Group B

AbstractGroup B Streptococcus (GBS) is a major cause of neonatal morbidity and mortality. Serbia has not fully implemented preventive measures against GBS neonatal diseases. Therefore, we aimed to assess the maternal GBS colonisation and invasive neonatal disease rate, to reveal the trends of antimicrobial resistance and serotype distribution of GBS from various patient groups. Randomly selected non-invasive (n = 991) and all invasive GBS (n = 80) collected throughout Serbia from 2015 to 2020 were tested for antimicrobial susceptibility, capsular typing, and hvgA detection. Overall, 877/5621 (15.6%) pregnant women were colonised with GBS. Invasive GBS infections incidence in infants (0.18/1000 live births) showed a decreasing trend (0.3 to 0.1/1000 live births). Type III was overrepresented in infants with invasive infections (n = 35, 58.3%), whereas type V predominated among colonised adults (n = 224, 25.5%) and those with noninvasive (n = 37, 32.5%) and invasive infections (n = 8, 40%). The hypervirulent clone III/ST17 was highly associated with invasive infections (n = 28, 35%), particularly late-onset disease (n = 9, 47.4%), showing an increase from 12.3 to 14.8%. The GBS resistance to erythromycin and clindamycin was 26.7% and 22.1%, respectively, with an upward trend. The emergence of the hypervirulent clone III/ST17 and the escalation in GBS resistance highlight an urgent need for continuous monitoring of GBS infections.

Immunochemical Characterization of the Polysaccharide Antigens of Group B Streptococci

1988 ◽  
Vol 10 (Supplement 2) ◽  
pp. S367-S371 ◽  
Author(s):  
D. G. Pritchard ◽  
M. L. Egan ◽  
B. M. Gray ◽  
H. C. Dillon
Keyword(s):  
Group B Streptococci ◽  
Immunochemical Characterization ◽  
Polysaccharide Antigens ◽  
Group B

scholarly journals CsrRS Regulates Group B Streptococcus Virulence Gene Expression in Response to Environmental pH: a New Perspective on Vaccine Development

2009 ◽  
Vol 191 (17) ◽  
pp. 5387-5397 ◽  
Author(s):  
Isabella Santi ◽  
Renata Grifantini ◽  
Sheng-Mei Jiang ◽  
Cecilia Brettoni ◽  
Guido Grandi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Factors ◽  
Vaccine Development ◽  
Ph Regulation ◽  
Protective Efficacy ◽  
Virulence Gene ◽  
Ph Sensing ◽  
Group B Streptococci ◽  
Virulence Gene Expression ◽  
Group B

ABSTRACT To identify factors involved in the response of group B streptococci (GBS) to environmental pH, we performed a comparative global gene expression analysis of GBS at acidic and neutral pHs. We found that the transcription of 317 genes was increased at pH 5.5 relative to that at pH 7.0, while 61 genes were downregulated. The global response to acid stress included the differential expression of genes involved in transport, metabolism, stress response, and virulence. Known vaccine candidates, such as BibA and pilus components, were also regulated by pH. We observed that many of the genes involved in the GBS response to pH are known to be controlled by the CsrRS two-component system. Comparison of the regulon of wild-type strain 2603 V/R with that of a csrRS deletion mutant strain revealed that the pH-dependent regulation of 90% of the downregulated genes and 59.3% of the up-regulated genes in strain 2603 V/R was CsrRS dependent and that many virulence factors were overexpressed at high pH. Beta-hemolysin regulation was abrogated by selective inactivation of csrS, suggesting the implication of the CsrS protein in pH sensing. These results imply that the translocation of GBS from the acidic milieu of the vagina to the neutral pH of the neonatal lung signals the up-regulation of GBS virulence factors and conversion from a colonizing to an invasive phenotype. In addition, the fact that increased exposure of BibA on the bacterial surface at pH 7.0 induced opsonophagocytic killing of GBS in immune serum highlights the importance of pH regulation in the protective efficacy of specific antibodies to surface-exposed GBS proteins.

Characterization of an IgA receptor from group B streptococci: specificity for serum IgA

1990 ◽  
Vol 20 (10) ◽  
pp. 2241-2247 ◽  
Author(s):  
Gunnar Lindahl ◽  
Bo Åkerström ◽  
Jean-Pierre Vaerman ◽  
Lars Stenberg
Keyword(s):  
Group B Streptococci ◽  
Serum Iga ◽  
Group B

Characterization of group B streptococcal glyceraldehyde-3-phosphate dehydrogenase: surface localization, enzymatic activity, and protein–protein interactions

2003 ◽  
Vol 49 (5) ◽  
pp. 350-356 ◽  
Author(s):  
Kyle N Seifert ◽  
William P McArthur ◽  
Arnold S Bleiweis ◽  
L Jeannine Brady
Keyword(s):  
Monoclonal Antibody ◽  
Western Blot ◽  
Protein Interactions ◽  
Fluid Phase ◽  
Protein Protein Interactions ◽  
Group B Streptococci ◽  
Whole Cells ◽  
Surface Localization ◽  
Group B

During characterization of the surface antigens of serotype III group B streptococci (GBS), a protein with an apparent Mr~ 173 500 migrating on a SDS – polyacrylamide gel was found to have an N-terminal amino acid sequence identical to that of the plasmin receptor (Plr) of group A streptococci, a surface-localized glyceraldehyde-3-phosphate dehydrogenase (GAPDH). This work begins to characterize GBS GAPDH and to assess its functional activity on the cell surface. The 1.0-kb gapC gene of GBS was amplified by PCR. plr and gapC demonstrated 87% homology. An anti-Plr monoclonal antibody reacted with GBS whole cells, suggesting GBS GAPDH is surface localized. Multiple serotypes of GBS demonstrated functional GAPDH on their surfaces. The anti-Plr monoclonal antibody recognized GBS protein bands of approximately 41 and 173.5 kDa, by Western blot. Presumably, these represent monomeric and tetrameric forms of the GAPDH molecule. GBS GAPDH was demonstrated by Western blot analysis to interact with lys- and glu-plasminogens. Fluid-phase GBS GAPDH interacted, by means of ELISA, with immobilized lys-plasminogen, glu-plasminogen, actin, and fibrinogen. Enzymatically active GAPDH, capable of binding cytoskeletal and extracellular matrix proteins, is expressed on the surface of GBS.Key words: group B streptococci, glyceraldehyde-3-phosphate dehydrogenase.

scholarly journals Correction for Six et al., Molecular Characterization of Nonhemolytic and Nonpigmented Group B Streptococci Responsible for Human Invasive Infections

2016 ◽  
Vol 54 (7) ◽  
pp. 1932-1932
Author(s):  
Anne Six ◽  
Arnaud Firon ◽  
Céline Plainvert ◽  
Camille Caplain ◽  
Abdelouhab Bouaboud ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Group B Streptococci ◽  
Invasive Infections ◽  
Group B
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