Abstract:Shiga toxin-producing Escherichia coli (STEC) is an important food-borne pathogen, which often exists in the intestines of ruminants, such as cow and sheep, as normal flora.[Objective] In this study, we isolated and identified Shiga toxin-producing Escherichia coli isolates from cow and sheep feces samples, and analyzed their pathogenic potentials Totally 11 Shiga toxin-producing Escherichia coli strains from sheeps and 1 isolate from cattle were isolated from Jiangsu, Yunnan, and Hebei, and another 10 isolates of STEC from cattle were donated by Tong Pan Group of Xinjiang Agricultural University. [Methods] We conducted the separation and identification through bacterial selective culture and detection of specific genes stx1 and stx2. We analyzed the pathogenic potential of the Shiga toxin-producing Escherichia coli isolates by Vero cytotoxicity test, hemolytic activity test, and toxin factor detection. [Results] In this study, the separation and identification result revealed that 11 isolates of sheep origin were isolated with an isolation rate of 17.5% (11/63); 1 isolate from cow origin was isolated with an isolation rate of 0.7% (1/134). The pathogenic potential results showed that, among the 11 sheep-derived isolates, 5 of them had strong toxicity to Vero cells, and 3 had hemolytic activity. Among the 11 cow-derived isolates, 5 had strong toxicity to Vero cells, and 3 had hemolytic activity. The eae gene carrying rate of the 11 sheep-derived Shiga toxin-producing Escherichia coli isolates was 63.6% (7/11), while the eae gene carrying rate of the cow-derived 11 Shiga toxin-producing Escherichia coli isolates was only 9.0% (1/11). [Conclusion] The results indicated that the isolation rate and pathogenic potential of the Shiga toxin-producing Escherichia coli strains derived from sheep were higher than the strains of cow origin. Therefore, sheep, as the host of Shiga toxin-producing Escherichia coli strains, should be paid higher attention than cow.
WeChat ID 
Mobile Terminal