scholarly journals Streptococcus agalactiae Cβ protein gene (bac) sequence types, based on the repeated region of the cell-wall-spanning domain: relationship to virulence and a proposed standardized nomenclature

2006 ◽  
Vol 55 (7) ◽  
pp. 829-837 ◽  
Author(s):  
Fanrong Kong ◽  
Heather F. Gidding ◽  
Reinhard Berner ◽  
Gwendolyn L. Gilbert
Keyword(s):  
Cell Wall ◽  
Streptococcus Agalactiae ◽  
Protein Gene ◽  
Group B Streptococcus ◽  
Sequence Length ◽  
Insertion Sequences ◽  
Specific Pcr ◽  
Group B ◽  
Sequence Types ◽  
Positive Results

The Cβ protein (Bac) of Streptococcus agalactiae (group B streptococcus; GBS) is an IgA binding protein encoded by bac, of which at least 39 sequence types have been described, based on polymorphisms in the repeated region of the cell-wall-spanning domain (‘bac sequence types’). Cβ is usually found in serotype Ib, less commonly in serotype II, and rarely in other serotypes. The aim of this study was to examine the prevalence, variety and distribution, among GBS serotypes and between invasive and superficial isolates, of bac sequence types. A total of 1101 GBS isolates were tested, from 10 countries, with a bac-specific PCR, and amplicons from all 255 (23 %) with positive results were sequenced. Ninety-seven percent (184/190) of serotype Ib and 37 % of serotype II isolates were bac positive. The Cα protein gene (bca) was present in 98 % (251/255), and insertion sequences IS1381 and IS861 in 94 % (239/255), of bac-positive isolates. The authors identified 59 bac sequence types belonging to 19 groups, based on length, from 496 to 946 bp, with up to six sequence variants (a–f) in each group. The median bac sequence length of invasive isolates was significantly shorter than that of superficial isolates overall (640 versus 586 bp; P <0.001) and specifically for serotype Ib (541 versus 676 bp; P <0.001), and invasive isolates were significantly (P <0.001) more likely to have one or more 18 bp deletions relative to the original published bac sequence (X59771). bac sequence typing is a useful addition to the previously described genotyping system, and will help to predict relative virulence among S. agalactiae serotype Ib strains.

scholarly journals Prevalence and Serotype Determination of Streptococcus agalactiae Isolated From Non-Pregnant Women in Tehran, Iran

2020 ◽  
Author(s):  
Leila Goudarzi ◽  
Mohammad Bagher Khalili ◽  
Mahmood Vakili ◽  
Maryam Sadeh
Keyword(s):  
Pregnant Women ◽  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Cross Sectional Study ◽  
Chi Square ◽  
Cross Sectional ◽  
Specific Pcr ◽  
Pcr Method ◽  
Group B ◽  
Tehran Area

Consequence of Streptococcus agalactiae, Group B Streptococcus (GBS) relating infant’s diseases are well documented. Although many women carry this bacterium in their vagina, they may transfer to their infant during delivery and may result in different neonatal invasive diseases. The aim of this study was to determine the prevalence of GBS and serotyping the isolated species among un-selective non-pregnant women who attended two gynecology clinics in Tehran. In this cross-sectional study, a total of 560 vaginal samples collected from non-pregnant women. Following inoculation of the specimen on Blood Agar, the standard technology was applied for the final identification of GBS. Detected GBS species were further confirmed using specific PCR directed on dlts gene. Capsular serotyping was done by using the multiplex PCR method. The chi-square method was used for statistical analysis. Fifty (8.9%) out of 560 non-pregnant women were carriers of GBS. The most common types were III (36%), followed by type II (32%), Ia (26%), and Ib (6%), respectively. Results represent that the prevalence rate of GBS in non-pregnant women was reliable and similar to what obtained from pregnant women. In addition, the serotype III was found the most dominant types, as well as other investigations in the Tehran area. Therefore, vaccine designation based on type III is recommended.

scholarly journals Distribution of Pilus Islands in Streptococcus agalactiae That Cause Human Infections: Insights into Evolution and Implication for Vaccine Development

2012 ◽  
Vol 20 (2) ◽  
pp. 313-316 ◽  
Author(s):  
E. R. Martins ◽  
A. Andreu ◽  
J. Melo-Cristino ◽  
M. Ramirez
Keyword(s):  
Streptococcus Agalactiae ◽  
Vaccine Development ◽  
Group B Streptococcus ◽  
Human Pathogens ◽  
Content Type ◽  
The Stability ◽  
Group B ◽  
Human Infections ◽  
Sequence Types

ABSTRACTAt least one pilus island, PI-1 (70%), PI-2a (79%), or PI-2b (21%), was found among 898Streptococcus agalactiae(group B streptococcus [GBS]) isolates recovered from humans, supporting the use of pilus proteins in vaccines. The stability and dominance of PI-1 and PI-2a in multiple serotypes and founder multilocus sequence types disseminated worldwide suggest it could be the PI combination present in ancestral GBS human pathogens.

An Emerging Infection: Streptococcal Toxic Shock-Like Syndrome Caused By Group B Streptococcus (GBS), Streptococcus Agalactiae

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S140-S140
Author(s):  
F Rajack ◽  
A Afsari ◽  
A M Ramadan ◽  
T J Naab
Keyword(s):  
Soft Tissue ◽  
Necrotizing Fasciitis ◽  
Streptococcus Agalactiae ◽  
Group A Streptococcus ◽  
Multiorgan Failure ◽  
Group B Streptococcus ◽  
Stage Iii ◽  
Streptococcal Toxic Shock Syndrome ◽  
Toxic Shock ◽  
Group B

Abstract Introduction/Objective Streptococcus agalactiae, Group B Streptococcus (GBS), is a major cause of neonatal sepsis and infections in pregnant women. However, incidence of invasive GBS infections has more than doubled in the last two decades with highest risk in adults 65 years or older. Other risk factors are diabetes, malignancy, and immunocompromised state. Bacteremia and skin soft tissue infections are the most common invasive infections in nonpregnant adults. Rarely GBS infection has a fulminating pyrogenic exotoxin-mediated course characterized by acute onset, multiorgan failure, shock, and sometimes death, referred to as toxic shock-like syndrome. Methods A 77-year-old hypertensive female with uncontrolled type 2 diabetes mellitus and a history of bilateral foot ulcers presented to the hospital in probable septic shock. Clinical diagnosis of necrotizing fasciitis was made and she underwent bilateral lower limb amputations. Results Grossly soft tissue appeared gray. Microscopically fascia was necrotic without neutrophils present and Gram stain revealed sheets of Gram positive cocci. These findings reflected histopathologic Stage III necrotizing fasciitis, which is associated with 47% mortality. Autopsy showed a similar histology of Stage III necrotizing fasciitis involving the surgical stump. Erythema and desquamation of the upper limbs bilaterally and multi-organ failure met the clinical picture of Streptococcal Toxic Shock Syndrome (STSS) and fulfilled the criteria for TSS due to Group A Streptococcus (GAS), defined by The Working Group on Severe Streptococcal Infections. Conclusion Group B Streptococcal Toxic Shock-Like Syndrome may have a similar outcome to STSS caused by GAS and other pathogens and, in limited studies, mortality has been 30% or greater.

scholarly journals To screen or not to screen women for Group B Streptococcus (Streptococcus agalactiae) to prevent early onset sepsis in newborns: recent advances in the unresolved debate

2020 ◽  
Vol 7 ◽  
pp. 204993612094242
Author(s):  
Guduru Gopal Rao ◽  
Priya Khanna
Keyword(s):  
Risk Factor ◽  
Antimicrobial Resistance ◽  
Low Income ◽  
Streptococcus Agalactiae ◽  
Early Onset ◽  
Group B Streptococcus ◽  
Developed Countries ◽  
Low Income Countries ◽  
Early Onset Sepsis ◽  
Group B

Streptococcus agalactiae, also known as Group B streptococcus (GBS) is the commonest cause of early onset sepsis in newborns in developed high-income countries. Intrapartum antimicrobial (antibiotic) prophylaxis (IAP) is recognized to be highly effective in preventing early onset Group B sepsis (EOGBS) in newborns. The key controversy is about the strategy that should be used to identify mothers who should receive IAP. There are two strategies that are followed in developed countries: screening-based or risk-factor-based identification of women requiring IAP. The debate regarding which of the two approaches is better has intensified in the recent years with concerns about antimicrobial resistance, effect on newborn’s microbiome and other adverse effects. In this review, we have discussed some of the key research papers published in the period 2015–2019 that have addressed the relative merits and disadvantages of screening versus risk-factor-based identification of women requiring IAP. Although screening-based IAP appears to be more efficacious than risk-based IAP, IAP-based prevention has several limitations including ineffectiveness in prevention of late-onset GBS infection in babies, premature and still births, impact of IAP on neonatal microbiota, emergence of antimicrobial resistance and difficulties in implementing IAP-based strategies in middle and low income countries. Alternative strategies, principally maternal immunization against GBS would circumvent use of IAP. However, no licensed vaccines are currently available for use.

scholarly journals Subtractive Hybridization Identifies a Novel Predicted Protein Mediating Epithelial Cell Invasion by Virulent Serotype III Group B Streptococcus agalactiae

2003 ◽  
Vol 71 (12) ◽  
pp. 6857-6863 ◽  
Author(s):  
Elisabeth E. Adderson ◽  
Shinji Takahashi ◽  
Yan Wang ◽  
Jianling Armstrong ◽  
Dylan V. Miller ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Newborn Infants ◽  
Subtractive Hybridization ◽  
Group B Streptococci ◽  
Mutant Type ◽  
Isogenic Mutant ◽  
Type Iii ◽  
Group B

ABSTRACT Group B Streptococcus agalactiae bacteria (group B streptococci [GBS]) are the most common cause of serious bacterial infection in newborn infants. The majority of serotype III-related cases of neonatal disease are caused by a genetically related subgroup of bacteria, restriction fragment digest pattern (RDP) type III-3, suggesting that these strains possess unique genes contributing to virulence. We used genomic subtractive hybridization to identify regions of genomic DNA unique to virulent RDP type III-3 GBS strains. Within one of these III-3-specific regions is a 1,506-bp open reading frame, spb1 (surface protein of group B streptococcus 1). A mutant type III GBS strain lacking Spb1 was constructed in virulent RDP type III-3 strain 874391, and the interactions of the wild-type and spb1 isogenic mutant with a variety of epithelial cells important to GBS colonization and infection were compared. While adherence of the spb1 isogenic mutant to A549 respiratory, C2Bbe1 colonic, and HeLa cervical epithelial cells was slightly lower than that of the 874391 strain, invasion of the Spb1− mutant was significantly reduced with these cell lines compared to what was seen with 874391. The defect in epithelial invasion was corrected by supplying spb1 in trans. These observations suggest that Spb1 contributes to the pathogenesis of neonatal GBS infection by mediating internalization of virulent serotype III GBS and confirm that understanding of the population structure of bacteria may lead to insights into the pathogenesis of human infections.

scholarly journals Features of Streptococcus agalactiae strains recovered from pregnant women and newborns attending different hospitals in Ethiopia

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Musa Mohammed Ali ◽  
Yimtubezinash Woldeamanuel ◽  
Daniel Asrat ◽  
Demissie Assegu Fenta ◽  
Bernard Beall ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Streptococcus Agalactiae ◽  
Vaccine Development ◽  
Group B Streptococcus ◽  
Tetracycline Resistance ◽  
Body Parts ◽  
Beta Lactam ◽  
Suspected Sepsis ◽  
Cross Sectional ◽  
Sequence Types

Abstract Background Streptococcus agalactiae (Group B Streptococcus, GBS) serotypes, sequence types, and antimicrobial resistance profile vary across different geographic locations affecting disease patterns in newborns. These differences are important considerations for vaccine development efforts and data from large countries in Africa is limited. The aim of this study was to determine serotypes and genotypes of GBS isolates from pregnant women and their newborns in Ethiopia. Methods A hospital based cross-sectional study was conducted at three hospitals in Ethiopia from June 2014 to September 2015. Out of 225 GBS isolates, 121 GBS were recovered, confirmed and characterized at CDC’s Streptococcus Laboratory using conventional microbiology methods and whole genome sequencing. Results Of the 121 isolates, 87 were from rectovaginal samples of pregnant women, 32 from different body parts of their newborns and 2 from blood of newborns with suspected sepsis. There were 25 mother-infant pairs and 24 pairs had concordant strains. The most prevalent serotypes among mothers and/or their babies were II, Ia and V (41.5, 20.6, 19.5 and 40.6%, 25 and 15.6%, respectively). Multilocus sequence typing (MLST) on 83 isolates showed ST10 (24; 28.9%) and ST2 (12; 14.5%) as most predominant sequence types. All GBS strains were susceptible to penicillin, cefotaxime and vancomycin, which correlated to the presence of wildtype PBP2x types and the lack of known vancomycin-resistance genes. Tetracycline resistance was high (73; 88%, associated primarily with tetM, but also tetO and tetL). Five isolates (6%) were resistant to erythromycin and clindamycin and 3 isolates were fluoroquinolone-resistant, containing associated mutations in gyrA and parC genes. All isolates were positive for one of four homologous Alpha/Rib family determinants and 1–2 of the three main pilus types. Conclusions Predominant serotypes were II, Ia, and V. A limited number of clonal types were identified with two STs accounting for about half of the isolates. All strains collected in this study were susceptible to beta-lactam antibiotics and vancomycin. Typical of most GBS, these isolates were positive for single alpha-like family protein, serine-rich repeat gene, as well as 1–2 pilus determinants.

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