Temporal Changes in Invasive Group B Streptococcus Serotypes: Implications for Vaccine Development

ABSTRACTUsing serotyping, multilocus sequence typing, and whole-genome sequencing (WGS) of selected strains, we studied the population structure of 102 group BStreptococcus(GBS) isolates prospectively sampled in 2014 from vaginal/rectal swabs of healthy pregnant women in metropolitan Toronto, Canada. We also determined the susceptibilities of each of the colonizing isolates to penicillin, erythromycin, clindamycin, tetracycline, and other antimicrobial agents. Overall, we observed a high rate of tetracycline resistance (89%) among colonizing GBS isolates. We found resistance to erythromycin in 36% of the strains, and 33% were constitutively or inducibly resistant to clindamycin. The most frequently identified serotypes were III (25%), Ia (23%), and V (19%). Serotype IV accounted for 6% of the colonizing isolates, a rate consistent with that observed among patients with invasive GBS infections in metropolitan Toronto. The majority of serotype IV isolates belonged to sequence type (ST)459, a tetracycline-, erythromycin-, and clindamycin-resistant ST first identified in Minnesota, which is considered to be the main driver of serotype IV GBS expansion in North America. WGS revealed that ST459 isolates from Canada are clonally related to colonizing and invasive ST459 organisms circulating in regions of the United States. We also used WGS to study recombination in selected colonizing strains from metropolitan Toronto, which revealed multiple episodes of capsular switching. Present and future circulating GBS organisms and their genetic diversity may influence GBS vaccine development.

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Disease burden and antimicrobial resistance of invasive group B streptococcus among infants in China: a protocol for a national prospective observational study

BMC Infectious Diseases ◽

10.1186/s12879-017-2475-9 ◽

2017 ◽

Vol 17 (1) ◽

Cited By ~ 6

Author(s):

Wenjing Ji ◽

Haiying Liu ◽

Zhengjiang Jin ◽

Aimin Wang ◽

Xiaoping Mu ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Observational Study ◽

Disease Burden ◽

Prospective Observational Study ◽

Group B Streptococcus ◽

Invasive Group ◽

Group B

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Current Status of Vaccine Development for Group B Streptococcus

NeoReviews ◽

10.1542/neo.15-10-e430 ◽

2014 ◽

Vol 15 (10) ◽

pp. e430-e438 ◽

Cited By ~ 6

Author(s):

K. M. Puopolo

Keyword(s):

Vaccine Development ◽

Group B Streptococcus ◽

Current Status ◽

Group B

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Molecular and phenotypic characterization of invasive group B streptococcus strains from infants in Norway 2006–2007

Clinical Microbiology and Infection ◽

10.1111/j.1469-0691.2009.02789.x ◽

2009 ◽

Vol 15 (12) ◽

pp. 1182-1185 ◽

Cited By ~ 15

Author(s):

H. Bergseng ◽

J.E. Afset ◽

A. Radtke ◽

K. Loeseth ◽

R.V. Lyng ◽

...

Keyword(s):

Group B Streptococcus ◽

Phenotypic Characterization ◽

Invasive Group ◽

Group B

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

Journal of obstetrics and women s diseases ◽

10.17816/jowd67562-73 ◽

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.

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Group B Streptococcus vaccine development: present status and future considerations, with emphasis on perspectives for low and middle income countries

F1000Research ◽

10.12688/f1000research.9363.1 ◽

2016 ◽

Vol 5 ◽

pp. 2355 ◽

Cited By ~ 42

Author(s):

Miwako Kobayashi ◽

Johan Vekemans ◽

Carol J. Baker ◽

Adam J. Ratner ◽

Kirsty Le Doare ◽

...

Keyword(s):

At Risk ◽

Disease Burden ◽

Vaccine Development ◽

Young Infant ◽

Group B Streptococcus ◽

Current Status ◽

Middle Income ◽

Young Infants ◽

Group B ◽

Low And Middle Income

Globally, group BStreptococcus(GBS) remains the leading cause of sepsis and meningitis in young infants, with its greatest burden in the first 90 days of life. Intrapartum antibiotic prophylaxis (IAP) for women at risk of transmitting GBS to their newborns has been effective in reducing, but not eliminating, the young infant GBS disease burden in many high income countries. However, identification of women at risk and administration of IAP is very difficult in many low and middle income country (LMIC) settings, and is not possible for home deliveries. Immunization of pregnant women with a GBS vaccine represents an alternate pathway to protecting newborns from GBS disease, through the transplacental antibody transfer to the fetus in utero. This approach to prevent GBS disease in young infants is currently under development, and is approaching late stage clinical evaluation.This manuscript includes a review of the natural history of the disease, global disease burden estimates, diagnosis and existing control options in different settings, the biological rationale for a vaccine including previous supportive studies, analysis of current candidates in development, possible correlates of protection and current status of immunogenicity assays. Future potential vaccine development pathways to licensure and use in LMICs, trial design and implementation options are discussed, with the objective to provide a basis for reflection, rather than recommendations.

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