Molecular epidemiology of pneumococci obtained from Gambian children aged 2-29 months with invasive pneumococcal disease during a trial of a 9-valent pneumococcal conjugate vaccine.
BACKGROUND
The study describes the molecular epidemiology of Streptococcus pneumoniae causing invasive disease in Gambian children


METHODS
One hundred and thirty-two S. pneumoniae isolates were recovered from children aged 2-29 months during the course of a pneumococcal conjugate vaccine trial conducted in The Gambia of which 131 were characterized by serotyping, antibiotic susceptibility, BOX-PCR and MLST.


RESULTS
Twenty-nine different serotypes were identified; serotypes 14, 19A, 12F, 5, 23F, and 1 were common and accounted for 58.3% of all serotypes overall. MLST analysis showed 72 sequence types (STs) of which 46 are novel. eBURST analysis using the stringent 6/7 identical loci definition, grouped the isolates into 17 clonal complexes and 32 singletons. The population structure of the 8 serotype 1 isolates obtained from 4 vaccinated and 2 unvaccinated children were the same (ST 618) except that one (ST3336) of the isolates from an unvaccinated child had a novel ST which is a single locus variant of ST 618.


CONCLUSIONS
We provide the first background data on the genetic structure of S. pneumoniae causing IPD prior to PC7V use in The Gambia. This data will be important for assessing the impact of PC7V in post-vaccine surveillance from The Gambia.
Antonio
Martin
M
Medical Research Council Laboratories, Banjul, The Gambia. mantonio@mrc.gm
Dada-Adegbola
Hannah
H
Biney
Ekow
E
Awine
Tim
T
O'Callaghan
John
J
Pfluger
Valentin
V
Enwere
Godwin
G
Okoko
Brown
B
Oluwalana
Claire
C
Vaughan
Adeola
A
Zaman
Syed Ma
SM
Pluschke
Gerd
G
Greenwood
Brian M
BM
Cutts
Felicity
F
Adegbola
Richard A
RA
D000483:Alleles; D002675:Child, Preschool; D002986:Clinical Trials as Topic; D005714:Gambia / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000276:immunology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification
D022242:Pneumococcal Vaccines