Antimicrobial resistance and prevalence of diarrheagenic Escherichia coli (DEC), in diarrheic yaks of Tibetan Plateau, China.

This study was conducted to test the distribution of diarrheagenic Escherichia coli (DEC) associated genes in fecal isolates from diarrheic yaks of a high remote region of China. Briefly, we obtained 203 fecal samples from diarrheic adult yaks and E. coli strains were isolated and identified via standard methods The antibiotic sensitivity of isolates was determined via disk diffusion method and polymerase chain reaction (PCR) was used to detect the DEC virulence associated genes. Results of the current study showed a high rate of resistance to tetracycline (93.6%) and low rate of resistance to ofloxacin (16.7%) antibiotics. Meanwhile, five different diarrheagenic associated virulence traits were detected including; EAEC (11.80%), EHEC (25.62%), EIEC (17.18%), EPEC (36.92%) and ETEC (11.36%). Moreover, E. coli isolates were positive for all tested DEC associated virulence genes ranging from 1.48% to 33%. Additionally, four isolates were positive for more than one virulence genes. In conclusion, our investigation showed a relatively low number of E. coli virulence genes isolated from diarrheic Tibetan yaks, which could be attributed to the high altitude induced harsh environmental conditions that may not help in the growth and survival of pathogenic organisms. In addition, this study highlights the high level of antibiotic resistance in yaks, therefore; preventive measures should be taken to monitor the antibiotic usage in Tibet region of China.