Objective: To study epidemiological characteristics of Escherichia coli O157:H7 isolated in Sichuan.
Methods: Multiplex PCR was used to analyze the slt1, slt2, eaeA, and hly gene. Plasmid profile and PFGE was utilized to investigate the homology among the strains. Drug and disinfectant resistance patterns of 67 stains were determined.
Results: The overall virulence gene prevalence was 62.7% (42/67); and the main virulence gene type was slt1 + slt2 + eaeA + hly. Of the 67 Escherichia coli O157: H7 strains, 5 plasmid profile and 6 PFGE types were acquired. 64.2% (43/67) Escherichia coli O157:H7 strains resisted to 7 antibiotics, namely, Ampicilin, Chloramphnicol, Tetracyline, Gentamicin, Cephlothin, SMZ, TMP-SMZ, and there were 23, 35, 34 strains resisted to Ampicilin, Tetracyline and SMZ respectively. The resistance types were different in Escherichia coli O157: H7 strains isolated from humans, animals, food, and environment. 80.6% (54/67) Escherichia coli 0157:H7 strains resisted to alcohol and quaternary ammonium, but all the stains were sensitive to chlorhexidiniacetas.
Conclusion: The virulence gene prevalence rate was familiar of 67 Escherichia coli O157: H7 Strains isolated from Sichuan, but virulence gene type was not the same in different sources. Bacterial drug resistance was high. Bacterial resistance to common disinfectants was so high that the strains could be killed by big dosage disinfectants. There were some familiarity with drug resistance, plasmid profile and PFGE types of 67 Escherichia coli 0157:H7 strains isolated from different sources, which indicated homology of the strains.