Multilocus sequence typing and pulsed-field gel electrophoresis analysis of Salmonella Paratyphi A isolates from 2000 to 2008, China.
- Author:
Hui HAN
1
;
Hai-jian ZHOU
;
Zhi-gang CUI
;
Peng-cheng DU
;
Biao KAN
Author Information
- Publication Type:Journal Article
- MeSH: Bacterial Typing Techniques; China; DNA, Bacterial; genetics; Electrophoresis, Gel, Pulsed-Field; methods; Humans; Multilocus Sequence Typing; Paratyphoid Fever; epidemiology; microbiology; Salmonella paratyphi A; classification; genetics; isolation & purification; Sequence Analysis, DNA; Serotyping
- From: Chinese Journal of Preventive Medicine 2010;44(9):810-814
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo analyze molecular and evolution characteristics of Salmonella Paratyphi A isolates from 2000 to 2008, China.
METHODSUsing pulsed-field gel electrophoresis (PFGE) method with SpeI restriction enzyme, and multilocus sequence typing (MLST) method based on housekeeping genes (aroC, thrA, hisD, purE, sucA, dnaN, hemD, adk, and purA), the genomic variations of 118 Salmonella Paratyphi A isolates from 10 regions during 2000 to 2008 were analyzed.
RESULTSUsing PFGE method, 118 Salmonella Paratyphi A isolates were clustered into 32 PFGE patterns, and 5 patterns were predominant (5 isolates or above). However, only 2 MLST types were identified for all isolates with MLST method. Among all Salmonella Paratyphi A isolates, the sequences of housekeeping genes were highly conservative and showed a high degree of cloning.
CONCLUSIONFor Chinese epidemic Salmonella Paratyphi A isolates during 2000 - 2008, MLST method showed low discrimination power and the MLST method should not be applied to outbreak and epidemiological surveillance of Salmonella Paratyphi A. Currently, nationwide paratyphoid fever epidemics is caused by highly clonal isolates in China. As the time changes, these isolates also accumulate sporadic mutations.
