Evaluation of Molecular Methods for Serotyping Shigella flexneri.
J Clin Microbiol
; 54(6): 1456-1461, 2016 06.
Article
em En
| MEDLINE
| ID: mdl-26984974
ABSTRACT
Shigella flexneri can be phenotypically serotyped using antisera raised to type-specific somatic antigens and group factor antigens and genotypically serotyped using PCR targeting O-antigen synthesis or modification genes. The aim of this study was to evaluate a real-time PCR for serotyping S. flexneri and to use whole-genome sequencing (WGS) to investigate the phenotypic and genotypic serotype identifications. Of the 244 cultures tested retrospectively, 226 (92.6%) had concordant results between phenotypic serotyping and PCR. Seventy of the 244 isolates (including 15 of the 18 isolates where a serotype-PCR mismatch was identified) were whole-genome sequenced, and the serotype was derived from the genome. Discrepant results between the phenotypic and genotypic tests were attributed to insertions/deletions or point mutations identified in O-antigen synthesis or modification genes, rendering them dysfunctional; inconclusive serotyping results due to nonspecific cross-reactions; or novel genotypes. Phylogenetic analysis of the WGS data indicated that the serotype, regardless of whether it was phenotypically or genotypically determined, was a weak predictor of phylogenetic relationships between strains of S. flexneri WGS data provided both genome-derived serotyping, thus supporting backward compatibility with historical data and facilitating data exchange in the community, and more robust and discriminatory typing at the single-nucleotide-polymorphism level.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Shigella flexneri
/
Sorotipagem
/
Técnicas de Genotipagem
/
Reação em Cadeia da Polimerase em Tempo Real
Tipo de estudo:
Evaluation_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Idioma:
En
Revista:
J Clin Microbiol
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Reino Unido