Virulence factors detection and pulsed field gel electrophoresis analysis of molecular typing on Shigella flexneri isolated from four provinces in China.

ShigellaThe roose of this study was to investigate the virulence genes carrying and molecular eidemiological features of]Shigella flexneri strains isolated from four rovinces of China in 2007.By using CR amlification,the distribution of iaH,Sen,Set1A and iaBCD virulence genes among the 262 strains were 100%,93.89%,96.18% and 92.75%,resectively.All isolates were classified into seven virulence gene carrying tyes.About 89.31% isolates were the virulence gene tyeⅠ(iaH+sen+set1A+iaBCD+),while 99.24% strains carried two or more virulence genes.As FGE was erformed according to the laboratory directions for molecular subtying of Shigella by FGE(ulseNet,USA) with some modifications,262 S.flexneri isolates were differentiated into 83 ulse tyes,and CNJZXN11.0002,CNJZXN11.0003,CNJZXN11.060,CNJZXN11.0081,CNJZXN11.0137,CNJZXN11.0169,CNJZXN11.0190,CNJZXN11.0195,CNJZXN11.0196,CNJZXN11.0199,CNJZXN11.0217,CNJZXN11.0325 and CNJZXN11.0327 were the 13 major atterns.CNJZXN11.0003 ulse tye was found in four rovinces,and CNJZXN11.0199 was the revalence ulse tye in Henan.CNJZXN11.0137,CNJZXN11.0325 and CNJZXN11.0327 ulse tyes were found only in Shanxi,and had lower similarity with CNJZXN11.0003.The results roved S.flexneri isolates have a high carrying rate of iaH,Sen,Set1A and iaBCD virulence genes in four rovinces.The distribution of ulse tyes of S.flexneri isolates was different in these regions,but some ulse tyes were crossing distribution.