Molecular epidemiology of group B streptococcal meningitis in children beyond the neonatal period from Angola

Abstract

Streptococcus agalactiae is a major pathogen of neonates and immunocompromised adults. Prior studies have demonstrated that, beyond the neonatal period, S. agalactiae rarely causes invasive infections in children. However, during 2004However, during -2005, S. agalactiae was the causative agent of 60 meningitis episodes in children aged 3 months to 12 years from Angola. To identify and study the specific causative genetic lineages of S. agalactiae childhood meningitis, which lack characterization to date, we conducted an extensive molecular analysis of the recovered isolates (n521). This constitutes what we believe to be the first molecular study of the population structure of invasive S. agalactiae isolates from Africa. A low genetic diversity was observed among the isolates, where the majority belonged to clonal complex (CC) 17 presenting the capsular subtype III-2 (86 % of cases) and marked by the intron group II GBSi1, which has previously been observed to be associated with neonatal hosts. The predominance of single-locus variants of sequence type (ST) 17 suggested the local diversification of this hypervirulent clone, which displayed novel alleles of the fbsB and sip virulence genes. The absence of the scpB-lmb region in two S. agalactiae isolates with the Ia/ST23 genotype is more typical of cattle than human isolates. Globally, these data provide novel information about the enhanced invasiveness of the CC17 genetic lineage in older children and suggest the local diversification of this clone, which may be related to the future emergence of a novel epidemic clone in Angola.

Streptococcus agalactiae Serotype Distribution and Antimicrobial Susceptibility in Pregnant Women in Gabon, Central Africa

“…In a systematic review and meta-analysis on S. agalactiae disease in infants aged <3 months no low-income country was represented in the serotype assessment due to lack of data; the most frequently identified serotype in all regions with available data was serotype III (48.9%) followed by serotypes Ia (22.9%), Ib (7.0%), II (6.2%), and V (9.1%), and five serotypes (Ia, Ib, II, III, V) accounted for >85% of all serotypes 15 . Limited data on molecular characteristics of African GBS isolates suggests that the overall population structure is similar to industrialized countries 16 17 18 .…”

Clinical profile and outcome of pediatric bacterial meningitis: a prospective study from tertiary institute in Northern India

“…8 Florindo et al, Dwivedi reported, 60, 27 and 5(17%) cases of Group B streptococcus meningitis in post neonatal period. 22,23 It is worth noticing that out of 26 cases of GBS meningitis 23, were diagnosed purely on the basis of LAT while only three (11%) had CSF findings suggestive of ABM in addition to LAT. Baker et al, also documented LAT to have high sensitivity for GBS as compared to culture.…”

Parallel Evolution of Group B Streptococcus Hypervirulent Clonal Complex 17 Unveils New Pathoadaptive Mutations

“…To complement our analysis of the CC17 clone, a similar approach was used to extract 923 publicly available GBS genomes belonging to CC1, CC19, and CC23 ( 8 , 15 , 16 , 18 , 19 ). A set of 45 CC17 strains provided by the Centre National de Référence des Streptocoques in France, the Collection de l’Institut Pasteur (CIP), and the pediatric hospital of Luanda ( 38 ) were also added and sequenced in this study ( Table S1 ).…”