Molecular typing of Shigella sonnei isolates circulating in Nanjing, China, 2007–2011

Autores: Cheng Tingting, Shi Xiaochao, Yong Wei, Wang Jianping, Xie Guoxiang, Ding Jie

Resumen

Introduction: Shigellosis is a major public health concern worldwide. This study intended to assess the baseline genotyping data among local Shigella sonnei strains spanning over five years. Methodology: Fifty non-repeat clinical strains of S. sonnei isolated from stools of patients in different hospitals in Nanjing, China, were studied. Three subtyping tools, pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST), and multi-locus variable-number tandem-repeat (VNTR) analysis (MLVA), were used for routinely subtyping local S. sonnei. Results: DNA sequencing only identified two sequence types (STs) among the 50 isolates in the MLST profiles, whereas PFGE and MLVA both showed suitable discriminatory power and yielded 19 and 30 different patterns, respectively. The major PFGE pattern comprised 21 strains isolated from different years. A total of four complexes were identified by MLVA, with the isolates differing by a single locus (single-locus variants). Conclusions: The S. sonnei strains circulating in Nanjing, China, in 2007–2011 originated from different clones with a degree of diversity. Most of the clones were closely related to each other. Overall, the strains were distinguishable by PFGE and MLVA. MLVA based on eight selected VNTR loci represented a more favorable degree of discrimination than did PFGE and may be a reliable complement for PFGE for routine subtyping of S. sonnei. The problems of MLST in subtyping regarding S. sonnei were also demonstrated.

Palabras clave: Shigella sonnei; molecular typing PFGE; multi-locus sequence typing; multi-locus variable-number tandem-repeat.

2014-12-15   |   302 visitas   |   Evalua este artículo 0 valoraciones

Vol. 8 Núm.12. Diciembre 2014 Pags. 1525-1532 J Infect Developing Countries 2014; 8(12)