TY - JOUR
T1 - Molecular epidemiology of group B streptococcal meningitis in children beyond the neonatal period from Angola.
AU - Santos Sanches, Ilda
PY - 2011/1/1
Y1 - 2011/1/1
N2 - Streptococcus agalactiae is a major pathogen of neonates and immunocompromized adults. Prior studies demonstrate that beyond the neonatal period, S. agalactiae rarely causes invasive infections in children. However, during 2004-2005, 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 (n=21). This constitutes 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 17 (CC-17) presenting the capsular subtype III-2 (86 % of cases) and marked by the intron group II GBSi1, whose association with neonatal hosts has been observed. The predominance of single locus variants of sequence type 17 (ST-17), suggested the local diversification of this hypervirulent clone, which displayed novel alleles of fbsB and sip virulence genes. The absence of scpB-lmb region in two S. agalactiae isolates with Ia/ST-23 genotype is more typical of cattle than human isolates. Globally, these data provide novel information about the enhanced invasiveness of the CC-17 genetic lineage in older children and suggest the local diversification of this clone, which may be related with the future emergence of a novel epidemic clone in Angola.
AB - Streptococcus agalactiae is a major pathogen of neonates and immunocompromized adults. Prior studies demonstrate that beyond the neonatal period, S. agalactiae rarely causes invasive infections in children. However, during 2004-2005, 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 (n=21). This constitutes 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 17 (CC-17) presenting the capsular subtype III-2 (86 % of cases) and marked by the intron group II GBSi1, whose association with neonatal hosts has been observed. The predominance of single locus variants of sequence type 17 (ST-17), suggested the local diversification of this hypervirulent clone, which displayed novel alleles of fbsB and sip virulence genes. The absence of scpB-lmb region in two S. agalactiae isolates with Ia/ST-23 genotype is more typical of cattle than human isolates. Globally, these data provide novel information about the enhanced invasiveness of the CC-17 genetic lineage in older children and suggest the local diversification of this clone, which may be related with the future emergence of a novel epidemic clone in Angola.
KW - LATE-ONSET
KW - ASSOCIATION
KW - INFANTS
KW - BACTERIAL-MENINGITIS
KW - ANTIBIOTIC-RESISTANCE
KW - AGALACTIAE
KW - COLONIZING STRAINS
KW - ERYTHROMYCIN
KW - POPULATION-STRUCTURE
KW - DISEASE
U2 - 10.1099/jmm.0.031674-0
DO - 10.1099/jmm.0.031674-0
M3 - Article
C2 - 21474607
SN - 0022-2615
VL - 60
SP - 1276
EP - 1280
JO - Journal of Medical Microbiology
JF - Journal of Medical Microbiology
IS - NA
ER -