OBJECTIVETo compare the discriminatory ability between multilocus sequence typing system (MLST) and pulsed-field gel electrophoresis (PFGE).

METHODSSalmonella enteritidis strains, isolated from food in China were identified by MLST, under PCR products of thrA, purE, sucA, aroC, hemD, dnaN and Sdf I. The same set of strains was typed by PFGE using Xba I, Spe I as the restriction enzyme in order to compare the discriminatory power of the methods.

RESULTSData from MLST revealed the lack of diversity among the strains of the same serotype and the number of variable nucleotide sites per locus ranged from 1 to 23 between Salmonella typhi LT2 and other serotypes of Salmonella. However, 50 Salmonella enteritidis strains were identified as 11 patterns and more sub-patterns by PFGE.

CONCLUSIONIn strain typing, PFGE was the highly discriminatory method comparing to the MLST system.