scholarly journals A unique serine-rich repeat protein (Srr-2) and novel surface antigen (ε) associated with a virulent lineage of serotype III Streptococcus agalactiae

Microbiology ◽  
2006 ◽  
Vol 152 (4) ◽  
pp. 1029-1040 ◽  
Author(s):  
Kyle N. Seifert ◽  
Elisabeth E. Adderson ◽  
April A. Whiting ◽  
John F. Bohnsack ◽  
Paula J. Crowley ◽  
...  
Keyword(s):  
Surface Antigen ◽  
Invasive Disease ◽  
Group B Streptococci ◽  
Gene Encoding ◽  
Repeat Protein ◽  
Encoding Gene ◽  
Group B ◽  
Mouse Model Of Infection ◽  
Highly Virulent

Group B streptococci (GBS) are pathogens of both neonates and adults, with serotype III strains in particular being associated with invasive disease and meningitis. In this study, a novel GBS surface antigen, ε, was found to be co-expressed with the previously reported δ antigen on an identical subset of serotype III GBS. Expression of δ/ε on the surface of serotype III GBS was shown to distinguish the restriction digest pattern (RDP) III-3 and multilocus sequence typing (ST)-17 lineage. ε-Specific antibodies were reactive with a unique, high-molecular-mass, serine-rich repeat protein (Srr-2) found exclusively in RDP III-3 strains. The gene encoding Srr-2 was located within a putative accessory secretory locus that included secY2 and secA2 homologues and had a genetic organization similar to that of the secY2/A2 locus of staphylococci. In contrast, serotype III δ/ε-negative strains and strains representative of serotypes Ia, Ib, Ic and II shared a common Srr-encoding gene, srr-1, and an organization of the secY2/A2 locus similar to that of previously reported serotype Ic, δ/ε-negative serotype III and serotype V GBS strains. Representative serotype III δ/ε-positive strains had LD90 values 3–4 logs less than those of serotype III δ/ε-negative strains in a neonatal mouse model of infection. These results indicate that the RDP III-3/ST-17 lineage expresses Srr-2 and is highly virulent in an in vivo model of neonatal sepsis.

scholarly journals Epidemiological aspects of group B streptococci of bovine and human origin

1996 ◽  
Vol 117 (3) ◽  
pp. 417-422 ◽  
Author(s):  
N. E. Jensen ◽  
F. M. Aarestrup
Keyword(s):  
Streptococcus Agalactiae ◽  
Double Diffusion ◽  
Restriction Enzymes ◽  
Group B Streptococci ◽  
Gene Encoding ◽  
Genetic Changes ◽  
Lactose Fermentation ◽  
Phenotypic Variations ◽  
Group B ◽  
Reference Strains

SummaryRestriction fragment length polymorphism of the gene encoding rRNA (ribotyping) was used in combination with conventional epidemiological markers to study phenotypic variations amongStreptococcus agalactiaeof bovine origin and the possible epidemiological interrelationship between the bovine and human reservoirs ofStreptococcus agalactiae.The bovine material constituted 53 strains (9 antigen combinations) isolated from 11 herds. Herds with a uniform as well as heterogenic antigenic pattern were included. Furthermore, strains isolated in the course of time from the same persistently infected quarters were examined. The human material constituted 16 strains, 4 each of 4 serotypes, isolated from healthy carriers. Finally, nine serotype- and the group reference strains were examined. All strains were serotyped by double diffusion in agarose gel, biotyped (lactose ±), and ribotyped using two restriction enzymes,HindIII andHhaI.All isolates could be typed by ribotyping and seven ribotypes were identified among the reference strains. The restriction enzymes used alone or in combination gave typing results that allowed discrimination between and within serotype. Combined use of serotype,HindIII andHhaI ribotypes produced 11 types among the 16 human strains. Ribotype analysis discriminated between herds infected with the same serotype. Strains of varying antigenic patterns from the same herd had the same ribotype. Phenotypic variations in serotype observed in persistent intramammary infection were not related to genetic changes as monitored by ribotype. Two ribotypes were represented among both bovine and human strains. The discriminating capability of lactose fermentation was of limited value.

scholarly journals Characterization of a Novel Leucine-Rich Repeat Protein Antigen from Group B Streptococci That Elicits Protective Immunity

2005 ◽  
Vol 73 (3) ◽  
pp. 1671-1683 ◽  
Author(s):  
Ravin Seepersaud ◽  
Sean B. Hanniffy ◽  
Peter Mayne ◽  
Phil Sizer ◽  
Richard Le Page ◽  
...  
Keyword(s):  
Significant Risk ◽  
Invasive Disease ◽  
Invasive Infection ◽  
Dependent Manner ◽  
Leucine Rich Repeat ◽  
Group B Streptococci ◽  
Lethal Challenge ◽  
Life Threatening ◽  
Group B

ABSTRACT Group B streptococci (GBS) usually behave as commensal organisms that asymptomatically colonize the gastrointestinal and urogenital tracts of adults. However, GBS are also pathogens and the leading bacterial cause of life-threatening invasive disease in neonates. While the events leading to transmission and disease in neonates remain unclear, GBS carriage and level of colonization in the mother have been shown to be significant risk factors associated with invasive infection. Surface antigens represent ideal vaccine targets for eliciting antibodies that can act as opsonins and/or inhibit colonization and invasion. Using a genetic screen for exported proteins in GBS, we identified a gene, designated lrrG, that encodes a novel LPXTG anchored surface antigen containing leucine-rich repeat (LRR) motifs found in bacterial invasins and other members of the LRR protein family. Southern blotting showed that lrrG was present in all GBS strains tested, representing the nine serotypes, and revealed the presence of an lrrG homologue in Streptococcus pyogenes. Recombinant LrrG protein was shown in vitro to adhere to epithelial cells in a dose-dependent manner, suggesting that it may function as an adhesion factor in GBS. More importantly, immunization with recombinant LrrG elicited a strong immunoglobulin G response in CBA/ca mice and protected against lethal challenge with virulent GBS. The data presented in this report suggest that this conserved protein is a highly promising candidate antigen for use in a GBS vaccine.

scholarly journals Demonstration of opsonic activity and in vivo protection against group B streptococci type III by Streptococcus pneumoniae type 14 antisera.

1978 ◽  
Vol 148 (3) ◽  
pp. 776-786 ◽  
Author(s):  
G W Fischer ◽  
G H Lowell ◽  
M H Crumrine ◽  
J W Bass
Keyword(s):  
Streptococcus Pneumoniae ◽  
Rat Model ◽  
In Vivo Studies ◽  
Group B Streptococci ◽  
Opsonic Activity ◽  
Type Iii ◽  
Neonatal Group ◽  
Group B ◽  
Type 3

The present studies demonstrate that antisera directed against Streptococcus pneumoniae type 14 is opsonic for group B streptococci type III in a neutrophile-mediated bactericidal assay. Specificity was demonstrated by the observations that group B streptococci type III and S. pneumoniae type 14 adsorbed the opsonic activity of anti-S. pneumoniae type 14 antisera. Group B streptococci strain 090R (devoid of type antigens) and S. pneumoniae type 3, did not remove the opsonic activity of anti-S. pneumoniae type 14 serum. In vivo studies using a suckling rat model of neonatal group B streptococcal type III sepsis demonstrated that antisera directed against S. pneumoniae type 14 was highly protective.

scholarly journals Distribution of Pilus island and antibiotic resistance genes in Streptococcus agalactiae obtained from vagina of pregnant women in Yazd, Iran

2020 ◽  
Author(s):  
Mahdieh Nabavinia ◽  
Mohammad Bagher Khalili ◽  
Maryam Sadeh ◽  
Gilda Eslami ◽  
Mahmood Vakili ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Pregnant Women ◽  
Multiplex Pcr ◽  
Resistance Genes ◽  
Streptococcus Agalactiae ◽  
Antibiotic Resistance Genes ◽  
Invasive Disease ◽  
Group B Streptococci ◽  
Resistance Factors ◽  
Group B

Background and Objectives: Due to the important role of Streptococcus agalactiae, Group B streptococci (GBS), in production of invasive disease in neonates, investigation regarding the pathogenicity and antibiotic resistance factors is necessary in selecting the appropriate therapeutic agents. Beside capsule, the pilus has been currently recognized as an important factor in enhancing the pathogenicity of GBS. Resistance of GBS to selected antibiotics is noticeably increasing which is mainly due to the anomalous use of these drugs for treatment. The aim of this study was to determine the prevalence of pili genes followed by antibiotic susceptibility of GBS, previously serotyped, isolated from pregnant women in the city of Yazd, Iran. Materials and Methods: Fifty seven GBS from pregnant women were subjected to multiplex PCR for determination of PI-1, PI-2a and PI-2b pilus-islands and simultaneously, the phenotype of antibiotic resistance to penicillin, tetracycline, erythromycin, clindamycin, gentamycin and levofloxacin was determined. Antibiotic resistance genes (ermA, ermB, mefA, tetM, int-Tn) were further diagnosed using PCR and multiplex PCR. Results: PI-1+PI-2a with 71.9%; followed by PI-2a (21.1%) and PI-2b (7%) were observed. PI-1+PI-2a in serotype III was (73.2%), serotype II, Ia, Ib and V were 12.2%, 9.8%, 2.4% and 2.4% respectively. GBS penicillin sensitive was 89.5% and 96.5% resistance to tetracycline. The frequency of resistance genes were as follows: tetM (93%), ermA (33.3%), ermB (8.8%), int-Tn (80.7%) and mefA (0). Conclusion: Majority of GBS contained PI-1+PI-2a. Hence presence of this pilus stabilizes the colonization, therefore designing a program for diagnosing and treatment of infected pregnant women seems to be necessary.

scholarly journals Two-Component System RgfA/C Activates the fbsB Gene Encoding Major Fibrinogen-Binding Protein in Highly Virulent CC17 Clone Group B Streptococcus

PLoS ONE ◽  
2011 ◽  
Vol 6 (2) ◽  
pp. e14658 ◽  
Author(s):  
Rim Al Safadi ◽  
Laurent Mereghetti ◽  
Mazen Salloum ◽  
Marie-Frédérique Lartigue ◽  
Isabelle Virlogeux-Payant ◽  
...  
Keyword(s):  
Binding Protein ◽  
Group B Streptococcus ◽  
Two Component System ◽  
Gene Encoding ◽  
Component System ◽  
Fibrinogen Binding ◽  
Two Component ◽  
Group B ◽  
Highly Virulent ◽  
Clone Group

scholarly journals CORRELATION OF HINDIII RESTRICTION DIGEST PATTERNS OF CHROMOSOMAL DNA FROM TYPE III GROUP B STREPTOCOCCI WITH INVASIVE DISEASE. • 1101

1996 ◽  
Vol 39 ◽  
pp. 186-186
Author(s):  
Shinji Takahashi ◽  
Mark R Briesacher ◽  
Judy A Daly ◽  
Karen C Carroll ◽  
Harry R Hill ◽  
...  
Keyword(s):  
Invasive Disease ◽  
Chromosomal Dna ◽  
Group B Streptococci ◽  
Type Iii ◽  
Restriction Digest ◽  
Group B

scholarly journals Phenotypic changes in group B streptococci grown in the presence of the polyols, erythritol, sorbitol and mannitol

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Maram Hulbah ◽  
Matthew A. Croxen ◽  
Gregory J. Tyrrell
Keyword(s):  
Epithelial Cell ◽  
Amniotic Fluid ◽  
Biofilm Formation ◽  
Surface Expression ◽  
Invasive Disease ◽  
Epithelial Cell Line ◽  
Sugar Alcohols ◽  
Group B Streptococci ◽  
Phenotypic Changes ◽  
Group B

Abstract Background Group B streptococci (GBS) are important neonatal bacterial pathogens that can cause severe invasive disease in the newborn. It is thought that in many cases of invasive neonatal GBS disease, the bacteria ascend the vagina into the uterus and infect the amniotic fluid surrounding the fetus. Important constituents of this environment include the polyols or sugar alcohols of which erythritol, sorbitol and mannitol are examples. The aim of our study was to investigate the effect of polyols on GBS grown in media containing these sugar alcohols. Results GBS incubated in varying concentrations of polyols (erythritol, sorbitol or mannitol) did not display any significant enhancement or inhibition of bacterial growth. However, growth of GBS in the presence of erythritol significantly increased the surface expression of GBS-PGK (a plasminogen binding protein) 1.25 to 1.5-fold depending on the erythritol concentration and significantly enhanced the survival in human blood 3X to 18X depending on the concentration of polyol used. Interestingly, GBS grown in 1% erythritol significantly increased invasion by the bacteria of HeLa cells (epithelial cell line) (150% vs 100%) however, at higher concentrations (2% or 4% of polyol) the number of CFUs was significantly reduced (55-75% vs 100%) suggesting higher concentrations of polyols may inhibit invasion. Erythritol also increased GBS hemolytic activity as well as enhancing biofilm formation 1.4X to 3.3X depending on the concentration of polyol used. Conclusions GBS grown in the presence of polyols alters the bacteria’s phenotype resulting in changes associated with GBS virulence. This effect was greatest for the polyol erythritol.

scholarly journals Infection-Derived Enterococcus faecalisStrains Are Enriched in esp, a Gene Encoding a Novel Surface Protein

1999 ◽  
Vol 67 (1) ◽  
pp. 193-200 ◽  
Author(s):  
Viswanathan Shankar ◽  
Arto S. Baghdayan ◽  
Mark M. Huycke ◽  
Gunnar Lindahl ◽  
Michael S. Gilmore
Keyword(s):  
Surface Protein ◽  
Group B Streptococci ◽  
Gene Encoding ◽  
Repeat Units ◽  
Enterococcal Species ◽  
Alternate Forms ◽  
Selection For ◽  
Group B ◽  
High Degree ◽  
Organizational Similarity

ABSTRACT We report the identification of a new cell wall-associated protein of Enterococcus faecalis. Studies on the distribution of the gene encoding this novel surface protein, Esp, reveal a significant (P < 0.001) enrichment in infection-derived E. faecalis isolates. Interestingly, the esp gene was not identified in any of 34 clinical E. faecium isolates or in 4 other less pathogenic enterococcal species tested. Analysis of the structural gene among various E. faecalis isolates reveals the existence of alternate forms of expression of the Esp protein. The deduced primary structure of the Esp protein from strain MMH594, inferred to be 1,873 amino acids (aa) with a predicted mass of ∼202 kDa, reveals a core region consisting of repeat units that make up 50% of the protein. Esp bears global organizational similarity to the Rib and C alpha proteins of group B streptococci. Identity among Esp, Rib, and C alpha proteins is strikingly localized to a stretch of 13 aa within repeats of similar length. The high degree of conservation of this 13-residue sequence suggests that it plays an important role in the natural selection for this trait among infection-derived E. faecalis and group B streptococcal isolates.

scholarly journals Antimicrobial Susceptibilities of Group B Streptococci Isolated from Patients with Invasive Disease: 10-Year Perspective

2001 ◽  
Vol 45 (12) ◽  
pp. 3623-3624 ◽  
Author(s):  
David R. Murdoch ◽  
L. Barth Reller
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Invasive Disease ◽  
Antimicrobial Susceptibility Testing ◽  
Streptococcal Infections ◽  
Group B Streptococci ◽  
Treatment And Prevention ◽  
Group B ◽  
High Level ◽  
Level Resistance

ABSTRACT Antimicrobial susceptibility testing of 192 group B streptococcal isolates from patients with invasive disease demonstrated that 31 (16%) were resistant to erythromycin and 17 (9%) were resistant to clindamycin. One isolate demonstrated high-level resistance to streptomycin, but none was highly resistant to gentamicin. Erythromycin and clindamycin are no longer reliable empirical alternatives to penicillin for the treatment and prevention of group B streptococcal infections.

scholarly journals Streptococcus salivarius K12 Limits Group B Streptococcus Vaginal Colonization

2015 ◽  
Vol 83 (9) ◽  
pp. 3438-3444 ◽  
Author(s):  
Kathryn A. Patras ◽  
Philip A. Wescombe ◽  
Berenice Rösler ◽  
John D. Hale ◽  
John R. Tagg ◽  
...  
Keyword(s):  
Group B Streptococcus ◽  
Neonatal Infection ◽  
Antibacterial Activities ◽  
Invasive Disease ◽  
Oral Microbiota ◽  
Streptococcus Salivarius ◽  
Content Type ◽  
Vaginal Colonization ◽  
Group B

Streptococcus agalactiae(group B streptococcus [GBS]) colonizes the rectovaginal tract in 20% to 30% of women and during pregnancy can be transmitted to the newborn, causing severe invasive disease. Current routine screening and antibiotic prophylaxis have fallen short of complete prevention of GBS transmission, and GBS remains a leading cause of neonatal infection. We have investigated the ability ofStreptococcus salivarius, a predominant member of the native human oral microbiota, to control GBS colonization. Comparison of the antibacterial activities of multipleS. salivariusstrains by use of a deferred-antagonism test showed thatS. salivariusstrain K12 exhibited the broadest spectrum of activity against GBS. K12 effectively inhibited all GBS strains tested, including disease-implicated isolates from newborns and colonizing isolates from the vaginal tract of pregnant women. Inhibition was dependent on the presence of megaplasmid pSsal-K12, which encodes the bacteriocins salivaricin A and salivaricin B; however, in coculture experiments, GBS growth was impeded by K12 independently of the megaplasmid. We also demonstrated that K12 adheres to and invades human vaginal epithelial cells at levels comparable to GBS. Inhibitory activity of K12 was examinedin vivousing a mouse model of GBS vaginal colonization. Mice colonized with GBS were treated vaginally with K12. K12 administration significantly reduced GBS vaginal colonization in comparison to nontreated controls, and this effect was partially dependent on the K12 megaplasmid. Our results suggest that K12 may have potential as a preventative therapy to control GBS vaginal colonization and thereby prevent its transmission to the neonate during pregnancy.

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