Molecular typing and occurrence of beta ‐lactam resistance genes of Shigella sonnei strains isolated during 1983‐2014 in the São Paulo State in Brazil

ABSTRACT Shigella sonnei is generally associated with dysentery in developed countries; but it has recently emerged in developing countries. Specifically, in Brazil there are few published studies that molecularly characterized this species. The aims of this study were to analyze the efficacy of the MLVA typing method, to study the phylogeny by MLST and to assess the presence of some beta‐lactam resistance genes in S. sonnei strains isolated from human diarrhoeic faeces in the São Paulo State in Brazil between 1983‐2014. Seventy‐two S. sonnei strains were typed by MLVA and grouped in two clusters, both presenting isolates from 1983‐2014. Furthermore, the discrimination index of MLVA was 0.996. Twenty strains were typed by MLST as ST152. In addition, the blaTEM gene was detected in 8 (72.7%) of the 11 S. sonnei strains, which showed to be previously resistant to β‐lactams. However, blaCTX‐M‐1group, blaCTX‐M‐9group and blaSHV genes were not found. MLVA results suggest the existence of two prevalent subtypes in the S. sonnei strains studied, confirming previous results. Moreover, MLVA could discriminate efficiently the monomorphic S. sonnei species. The S. sonnei strains studied belonged to clonal complex 152 and all isolates were typed as ST152; therefore, the MLST is not suitable method for studying the population structure of S. sonnei. Although, the β‐lactams resistance rates of the present work were not high, the frequency of blaTEM may represent a ri...
Source: Microbiology and Immunology - Category: Microbiology Authors: Tags: Original Article Source Type: research