scholarly journals Group B Streptococcal Colonization in African Countries: Prevalence, Capsular Serotypes, and Molecular Sequence Types

Pathogens ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1606
Author(s):  
Sarah Shabayek ◽  
Patricia Ferrieri ◽  
Barbara Spellerberg
Keyword(s):  
Group B Streptococcus ◽  
Epidemiological Data ◽  
Protein Vaccine ◽  
African Countries ◽  
Suitable Alternative ◽  
Promising Alternative ◽  
Molecular Sequence ◽  
Resource Limited ◽  
Group B ◽  
Sequence Types

Streptococcus agalactiae or group B streptococcus (GBS) is a commensal of the gastrointestinal and genitourinary tracts of healthy women and an important cause of neonatal invasive infections worldwide. Transmission of bacteria to the newborn occurs at birth and can be prevented by intrapartum antibiotic prophylaxis. However, this not available in resource limited settings in Africa, which carries a particular high burden of disease. Serotype based vaccines are in development and present a suitable alternative to prevent neonatal infections. To be able to assess vaccine efficacy, knowledge and surveillance of GBS epidemiological data are required. This review summarizes investigations about the serotype distribution and the multi-locus sequence types (MLST) found in different African countries. While most serotypes and MLST data are comparable to findings from other continents, some specific differences exist. Serotype V is predominant among colonizing maternal strains in many different African countries. Serotypes that are rarely detected in western industrialized nations, such as serotypes VI, VII and IX, are prevalent in studies from Ghana and Egypt. Moreover, some specific MLST sequence types that seem to be more or less unique to Africa have been detected. However, overall, the data confirm that a hexavalent vaccine can provide broad coverage for the African continent and that a protein vaccine could represent a promising alternative.

scholarly journals Molecular epidemiology of infections caused by group B Streptococcus in pregnant women and newborns, and development of preventive vaccines

2018 ◽  
Vol 67 (5) ◽  
pp. 62-73
Author(s):  
Vasilisa A. Vasilyeva ◽  
Elena V. Shipitsyna ◽  
Kira V. Shalepo ◽  
Alevtina M. Savicheva
Keyword(s):  
Capsular Polysaccharide ◽  
Vaccine Development ◽  
Current Knowledge ◽  
Group B Streptococcus ◽  
Epidemiological Data ◽  
Group B Streptococci ◽  
Group B ◽  
Sequence Types ◽  
Experimental Immunization ◽  
Selection Of

Hypothesis/aims of study. The present analysis was undertaken to summarize current knowledge about molecular properties of group B streptococci (GBS), emphasizing potential targets of vaccines against neonatal GBS infection. Study design, materials, and methods. This review is based on articles published mainly in the last ten years. Results. Epidemiological data on serotypes, multilocus sequence types, clonal complexes of GBS and their relationship are presented. Genetic events in GBS populations indicate significant obstacles to vaccine development. We described key properties of major GBS virulence factors, such as capsular polysaccharide, pili, and cell adhesion molecules, as well as results of experimental immunization on their basis. Conclusion. The population of invasive GBS strains is molecularly and genetically heterogeneous, which complicates selection of vaccine targets. Capsular switching, a low level of immunogenicity and variability of population composition are the most important factors that necessitate the accumulation and monitoring of molecular epidemiological data.

scholarly journals Challenges in reducing group B Streptococcus disease in African settings

2016 ◽  
Vol 102 (1) ◽  
pp. 72-77 ◽  
Author(s):  
Yo Nishihara ◽  
Ziyaad Dangor ◽  
Neil French ◽  
Shabir Madhi ◽  
Robert Heyderman
Keyword(s):  
Late Onset ◽  
Group B Streptococcus ◽  
Phase Iii ◽  
Current Evidence ◽  
African Countries ◽  
Mortality And Morbidity ◽  
Preventative Measures ◽  
Resource Limited ◽  
Sub Saharan ◽  
Group B

Group B Streptococcus (GBS) is a leading cause of neonatal sepsis and meningitis in high-income settings and is associated with high rates of neonatal mortality and morbidity. There is now increasing evidence to suggest that there is a high GBS disease burden in resource-limited countries, and it is therefore critically important to identify suitable and practical preventive strategies. In Europe and North America, intrapartum antibiotic prophylaxis (IAP) has led to a dramatic reduction of early-onset GBS disease. However, the methods for identifying pregnant women who should receive IAP and how to reduce late-onset GBS disease are not without controversy and are challenging for most sub-Saharan African countries. GBS vaccines are approaching phase III trials but are still under development. This review aims to explore the current evidence related to strategies for reducing invasive GBS disease in an African setting, the development of a GBS vaccine and whether preventative measures against GBS disease can be practically implemented.

Protection against experimental infection with group B streptococcus by immunization with a bivalent protein vaccine

Vaccine ◽  
1999 ◽  
Vol 17 (5) ◽  
pp. 454-458 ◽  
Author(s):  
Charlotte Larsson ◽  
Margaretha Stålhammar-Carlemalm ◽  
Gunnar Lindahl
Keyword(s):  
Experimental Infection ◽  
Group B Streptococcus ◽  
Protein Vaccine ◽  
Group B

Population structure of group B streptococcus from a low-incidence region for invasive neonatal disease

Microbiology ◽  
2005 ◽  
Vol 151 (6) ◽  
pp. 1875-1881 ◽  
Author(s):  
Naiel Bisharat ◽  
Nicola Jones ◽  
Dror Marchaim ◽  
Colin Block ◽  
Rosalind M. Harding ◽  
...  
Keyword(s):  
Population Structure ◽  
Disease Incidence ◽  
Group B Streptococcus ◽  
Invasive Disease ◽  
Multilocus Genotype ◽  
Neonatal Disease ◽  
Strain Collection ◽  
Low Incidence ◽  
Group B ◽  
Sequence Types

The population structure of group B streptococcus (GBS) from a low-incidence region for invasive neonatal disease (Israel) was investigated using multilocus genotype data. The strain collection consisted of isolates from maternal carriage (n=104) and invasive neonatal disease (n=50), resolving into 46 sequence types. The most prevalent sequence types were ST-1 (17·5 %), ST-19 (10·4 %), ST-17 (9·7 %), ST-22 (8·4 %) and ST-23 (6·5 %). Serotype III was the most common, accounting for 29·2 % of the isolates. None of the serotypes was significantly associated with invasive neonatal disease. burst analysis resolved the 46 sequence types into seven lineages (clonal complexes), from which only lineage ST-17, expressing serotype III only, was significantly associated with invasive neonatal disease. Lineage ST-22 expressed mainly serotype II, and was significantly associated with carriage. The distribution of the various sequence types and lineages, and the association of lineage ST-17 with invasive disease, are consistent with the results of analyses from a global GBS isolate collection. These findings could imply that the global variation in disease incidence is independent of the circulating GBS populations, and may be more affected by other risk factors for invasive GBS disease, or by different prevention strategies.

scholarly journals Seroepidemiology of maternally-derived antibody against Group B Streptococcus (GBS) in Mulago/Kawempe Hospitals Uganda - PROGRESS GBS

2020 ◽  
Vol 4 ◽  
pp. 155
Author(s):  
Mary Kyohere ◽  
Hannah Georgia Davies ◽  
Philippa Musoke ◽  
Annettee Nakimuli ◽  
Valerie Tusubira ◽  
...  
Keyword(s):  
Placental Transfer ◽  
Young Infant ◽  
Group B Streptococcus ◽  
Maternal Blood ◽  
Antibody Concentration ◽  
Large Sample Size ◽  
High Burden ◽  
Resource Limited ◽  
Entry Points ◽  
Group B

Background: Group B Streptococcus (GBS) is a major contributor to the high burden of neonatal and young infant infectious disease in resource- limited settings. As disease protection during the first six months of life is provided via placental transfer of maternal antibodies, a maternal GBS vaccine may provide an effective strategy to reduce infectious death and disability. An efficacy study may be difficult because of the large sample size required and alternative approaches such as serocorrelates of protection based on natural antibody concentration are being considered. Such studies would need to be undertaken in high burden settings such as Uganda. We therefore aim to evaluate the feasibility and acceptability of a GBS sero-epidemiology study in Kampala, Uganda. Methods: This is a prospective cohort and nested case-control study, conducted across two-centres with two entry points. A) consecutive women and their infants at birth, with collection of maternal swab, cord and maternal blood, and follow up by telephone until the infant is 3 months old; B) any infant under 3 months of age, presenting with signs of sepsis to any of the paediatric units, with collection of blood culture, cerebrospinal fluid and nasopharyngeal swabs. Any infants identified as having GBS disease (defined as GBS isolated from a normally sterile site) will be recruited and followed up for two years to assess their neurodevelopment. A nested qualitative study will investigate stakeholder (pregnant women and their families, healthcare workers and community leaders) opinions of sampling for such a study and understanding and potential uptake of vaccines in pregnancy. Discussion: The primary aim is to determine anti-GBS antibody concentration in infants with GBS disease compared to healthy controls. Secondary outcomes include stillbirth and all-cause infection and acceptance of sample methods and vaccination. The findings will inform scalability and sustainability of the programme in Uganda.

scholarly journals Seroepidemiology of maternally-derived antibody against Group B Streptococcus (GBS) in Mulago/Kawempe Hospitals Uganda - PROGRESS GBS

2020 ◽  
Vol 4 ◽  
pp. 155
Author(s):  
Mary Kyohere ◽  
Hannah Georgia Davies ◽  
Philippa Musoke ◽  
Annettee Nakimuli ◽  
Valerie Tusubira ◽  
...  
Keyword(s):  
Placental Transfer ◽  
Young Infant ◽  
Group B Streptococcus ◽  
Maternal Blood ◽  
Antibody Concentration ◽  
Large Sample Size ◽  
High Burden ◽  
Resource Limited ◽  
Entry Points ◽  
Group B

Background: Group B Streptococcus (GBS) is a major contributor to the high burden of neonatal and young infant infectious disease in resource- limited settings. As disease protection during the first six months of life is provided via placental transfer of maternal antibodies, a maternal GBS vaccine may provide an effective strategy to reduce infectious death and disability. An efficacy study may be difficult because of the large sample size required and alternative approaches such as serocorrelates of protection based on natural antibody concentration are being considered. Such studies would need to be undertaken in high burden settings such as Uganda. We therefore aim to evaluate the feasibility and acceptability of a GBS sero-epidemiology study in Kampala, Uganda. Methods: This is a prospective cohort and nested case-control study, conducted across two-centres with two entry points. A) consecutive women and their infants at birth, with collection of maternal swab, cord and maternal blood, and follow up by telephone until the infant is 3 months old; B) any infant under 3 months of age, presenting with signs of sepsis to any of the paediatric units, with collection of blood culture, cerebrospinal fluid and nasopharyngeal swabs. Any infants identified as having GBS disease (defined as GBS isolated from a normally sterile site) will be recruited and followed up for two years to assess their neurodevelopment. A nested qualitative study will investigate stakeholder (pregnant women and their families, healthcare workers and community leaders) opinions of sampling for such a study and understanding and potential uptake of vaccines in pregnancy. Discussion: The primary aim is to determine anti-GBS antibody concentration in infants with GBS disease compared to healthy controls. Secondary outcomes include stillbirth and all-cause infection and acceptance of sample methods and vaccination. The findings will inform scalability and sustainability of the programme in Uganda.

scholarly journals The antimicrobial activity of zinc against group B Streptococcus is strain-dependent across diverse sequence types, capsular serotypes, and invasive versus colonizing isolates

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Jamisha D. Francis ◽  
Miriam A. Guevara ◽  
Jacky Lu ◽  
Shabir A. Madhi ◽  
Gaurav Kwatra ◽  
...  
Keyword(s):  
Reproductive Tract ◽  
Group B Streptococcus ◽  
Antimicrobial Properties ◽  
Zinc Toxicity ◽  
Capsular Type ◽  
Zinc Stress ◽  
Wide Range ◽  
Invasive Infections ◽  
Group B ◽  
Sequence Types

Abstract Background Streptococcus agalactiae or Group B Streptococcus (GBS) is an encapsulated gram-positive bacterial pathobiont that commonly colonizes the lower gastrointestinal tract and reproductive tract of human hosts. This bacterium can infect the gravid reproductive tract and cause invasive infections of pregnant patients and neonates. Upon colonizing the reproductive tract, the bacterial cell is presented with numerous nutritional challenges imposed by the host. One strategy employed by the host innate immune system is intoxication of bacterial invaders with certain transition metals such as zinc. Methodology Previous work has demonstrated that GBS must employ elegant strategies to circumnavigate zinc stress in order to survive in the vertebrate host. We assessed 30 strains of GBS from diverse isolation sources, capsular serotypes, and sequence types for susceptibility or resistance to zinc intoxication. Results Invasive strains, such as those isolated from early onset disease manifestations of GBS infection were significantly less susceptible to zinc toxicity than colonizing strains isolated from rectovaginal swabs of pregnant patients. Additionally, capsular type III (cpsIII) strains and the ST-17 and ST-19 strains exhibited the greatest resilience to zinc stress, whereas ST-1 and ST-12 strains as well as those possessing capsular type Ib (cpsIb) were more sensitive to zinc intoxication. Thus, this study demonstrates that the transition metal zinc possesses antimicrobial properties against a wide range of GBS strains, with isolation source, capsular serotype, and sequence type contributing to susceptibility or resistance to zinc stress.

scholarly journals Estimation of country-level incidence of early-onset invasive Group B Streptococcus disease in infants using Bayesian methods

2021 ◽  
Vol 17 (6) ◽  
pp. e1009001
Author(s):  
Bronner P. Gonçalves ◽  
Simon R. Procter ◽  
Sam Clifford ◽  
Artemis Koukounari ◽  
Proma Paul ◽  
...  
Keyword(s):  
Early Onset ◽  
Disease Incidence ◽  
Group B Streptococcus ◽  
Epidemiological Data ◽  
Epidemiological Studies ◽  
Invasive Disease ◽  
Country Level ◽  
Detection Assay ◽  
Group B ◽  
Country Specific

Neonatal invasive disease caused by Group B Streptococcus (GBS) is responsible for much acute mortality and long-term morbidity. To guide development of better prevention strategies, including maternal vaccines that protect neonates against GBS, it is necessary to estimate the burden of this condition globally and in different regions. Here, we present a Bayesian model that estimates country-specific invasive GBS (iGBS) disease incidence in children aged 0 to 6 days. The model combines different types of epidemiological data, each of which has its own limitations: GBS colonization prevalence in pregnant women, risk of iGBS disease in children born to GBS-colonized mothers and direct estimates of iGBS disease incidence where available. In our analysis, we present country-specific maternal GBS colonization prevalence after adjustment for GBS detection assay used in epidemiological studies. We then integrate these results with other epidemiological data and estimate country-level incidence of iGBS disease including in countries with no studies that directly estimate incidence. We are able to simultaneously estimate two key epidemiological quantities: the country-specific incidence of early-onset iGBS disease, and the risk of iGBS disease in babies born to GBS-colonized women. Overall, we believe our method will contribute to a more comprehensive quantification of the global burden of this disease, inform cost-effectiveness assessments of potential maternal GBS vaccines and identify key areas where data are necessary.

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 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.

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