In:
Journal of Clinical Microbiology, American Society for Microbiology, Vol. 54, No. 5 ( 2016-05), p. 1326-1334
Abstract:
Serotype 1 is an important cause of invasive pneumococcal disease in South Africa and has declined following the introduction of the 13-valent pneumococcal conjugate vaccine in 2011. We genetically characterized 912 invasive serotype 1 isolates from 1989 to 2013. Simpson's diversity index (D) and recombination ratios were calculated. Factors associated with sequence types (STs) were assessed. Clonal complex 217 represented 96% (872/912) of the sampled isolates. Following the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13), ST diversity increased in children 〈 5 years (D, 0.39 to 0.63, P = 0.002) and individuals 〉 14 years (D, 0.35 to 0.54, P 〈 0.001): ST-217 declined proportionately in children 〈 5 years (153/203 [75%] versus 21/37 [57%] , P = 0.027) and individuals 〉 14 years (242/305 [79%] versus 96/148 [65%] , P = 0.001), whereas ST-9067 increased (4/684 [0.6%] versus 24/228 [11%] , P 〈 0.001). Three subclades were identified within ST-217: ST-217 C1 (353/382 [92%]), ST-217 C2 (15/382 [4%]), and ST-217 C3 (14/382 [4%]). ST-217 C2 , ST-217 C3 , and single-locus variant (SLV) ST-8314 (20/912 [2%]) were associated with nonsusceptibility to chloramphenicol, tetracycline, and co-trimoxazole. ST-8314 (20/912 [2%] ) was also associated with increased nonsusceptibility to penicillin ( P 〈 0.001). ST-217 C3 and newly reported ST-9067 had higher recombination ratios than those of ST-217 C1 (4.344 versus 0.091, P 〈 0.001; and 0.086 versus 0.013, P 〈 0.001, respectively). Increases in genetic diversity were noted post-PCV13, and lineages associated with antimicrobial nonsusceptibility were identified.
Type of Medium:
Online Resource
ISSN:
0095-1137
,
1098-660X
DOI:
10.1128/JCM.00055-16
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2016
detail.hit.zdb_id:
1498353-9
SSG:
12
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