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. 2023 Nov;9(11):001140.
doi: 10.1099/mgen.0.001140.

Molecular epidemiology of Streptococcus agalactiae in non-pregnant populations: a systematic review

Luria Leslie Founou  1   2   3 , Uzma Basit Khan  4 , Nubwa Medugu  5 , Tatiana C A Pinto  6 , Saffiatou Darboe  7 , Zhu Chendi  8 , Raspail Carrel Founou  9   3   10 , Ka-Ning To  11 , Dorota Jamrozy  4 , Konstantinos Karampatsas  11 , Victoria R Carr  12   4 , Kevin Pepper  4 , Ziyaad Dangor  13 , Margaret Ip  8 , Kirsty Le Doare  14 , Stephen D Bentley  15   4
Affiliations

Molecular epidemiology of Streptococcus agalactiae in non-pregnant populations: a systematic review

Luria Leslie Founou et al. Microb Genom. 2023 Nov.

Abstract

Streptococcus agalactiae (group B Streptococcus, GBS) has recently emerged as an important pathogen among adults. However, it is overlooked in this population, with all global efforts being directed towards its containment among pregnant women and neonates. This systematic review assessed the molecular epidemiology and compared how the lineages circulating among non-pregnant populations relate to those of pregnant and neonatal populations worldwide. A systematic search was performed across nine databases from 1 January 2000 up to and including 20 September 2021, with no language restrictions. The Joanna Briggs Institute (JBI) Prevalence Critical Appraisal Tool (PCAT) was used to assess the quality of included studies. The global population structure of GBS from the non-pregnant population was analysed using in silico typing and phylogenetic reconstruction tools. Twenty-four articles out of 13 509 retrieved across 9 databases were eligible. Most studies were conducted in the World Health Organization European region (12/24, 50 %), followed by the Western Pacific region (6/24, 25 %) and the Americas region (6/24, 25 %). Serotype V (23%, 2310/10240) and clonal complex (CC) 1 (29 %, 2157/7470) were the most frequent serotype and CC, respectively. The pilus island PI1 : PI2A combination (29 %, 3931/13751) was the most prevalent surface protein gene, while the tetracycline resistance tetM (55 %, 5892/10624) was the leading antibiotic resistance gene. This study highlights that, given the common serotype distribution identified among non-pregnant populations (V, III, Ia, Ib, II and IV), vaccines including these six serotypes will provide broad coverage. The study indicates advanced molecular epidemiology studies, especially in resource-constrained settings for evidence-based decisions. Finally, the study shows that considering all at-risk populations in an inclusive approach is essential to ensure the sustainable containment of GBS.

Keywords: One Health; Streptococcus agalactiae; antibiotic resistance; molecular epidemiology; non-pregnant populations; virulence.

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Conflict of interest statement

The authors declare that there are no conflicts of interest.

Figures

Fig. 1.
Fig. 1.
PRISMA flow chart summarizing the study selection process.
Fig. 2.
Fig. 2.
Distribution of GBS serotypes (n=10240) among included studies. (a) Overall distribution of GBS serotypes. (b) Sub-group analyses of GBS serotypes per age group. (c) Sub-group analyses of GBS serotypes per outcome. (d) Sub-group analyses of GBS serotypes per WHO region.
Fig. 3.
Fig. 3.
Distribution of GBS clonal complexes (n=7470) among included studies. (a) Overall distribution of GBS clonal complexes. (b) Sub-group analyses of GBS clonal complexes per age group. (c) Sub-group analyses of GBS clonal complexes per outcome. (d) Sub-group analyses of GBS clonal complexes per WHO region.
Fig. 4.
Fig. 4.
Overall distribution of antibiotic resistance (a) and surface protein genes (b).
Fig. 5.
Fig. 5.
Serotype distribution of CC1 isolates (n=2555) per four study populations.
Fig. 6.
Fig. 6.
Phylogenetic relationship between GBS isolates belonging to CC1 (n=2555). (a) Zoom-in snapshot of clade A. (b) Zoom-in snapshot of clade C.
See this image and copyright information in PMC

References

    1. Seale AC, Bianchi-Jassir F, Russell NJ, Kohli-Lynch M, Tann CJ, et al. Estimates of the burden of group B Streptococcal disease worldwide for pregnant women, stillbirths, and children. Clin Infect Dis. 2017;65:S200–S219. doi: 10.1093/cid/cix664. - DOI - PMC - PubMed
    1. World Health Organization (WHO) WHO Preferred Product Characteristics for Group B Streptococcus Vaccines. Geneva: World Health Organization; 2017.
    1. van Kassel MN, Janssen S, Kofman S, Brouwer MC, van de Beek D, et al. Prevalence of group B streptococcal colonization in the healthy non-pregnant population: a systematic review and meta-analysis. Clin Microbiol Infect. 2021;27:968–980. doi: 10.1016/j.cmi.2021.03.024. - DOI - PubMed
    1. Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:71. doi: 10.1136/bmj.n71. - DOI - PMC - PubMed
    1. Ouzzani M, Hammady H, Fedorowicz Z, Elmagarmid A. Rayyan-a web and mobile app for systematic reviews. Syst Rev. 2016;5:210. doi: 10.1186/s13643-016-0384-4. - DOI - PMC - PubMed

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