Prevalence and Antibiotic Susceptibility Profile of Virulent Multi-Drug Resistant Escherichia coli O157 Isolates in Native Cattle (Bos taurus L.) from Selected Farms in Indang, Cavite, Philippines
The study was done to ascertain the prevalence of virulent Escherichia coli O157 in the fecal samples of native cattle (Bos taurus L.) from selected farms in Indang, Cavite, Philippines and determine the antibiotic susceptibility profile of the isolates against selected antimicrobials. A total of 24 presumptive enterohemorrhagic E. coli (EHEC) cells were isolated from the feces of native cattle among the 70 animals sampled. Of these, five isolates were E. coli O157 based on the agglutination test and PCR detection of the O157 (rfbO157) gene. All isolates were hemolytic on washed sheep red blood agar plate and possessed the hlyA gene for hemolysin as detected through PCR, showing the virulence potential of the organisms. Results of the antibiotic sensitivity test showed that the isolates were resistant to erythromycin, trimethoprim/sulfamethoxazole and clarithromycin, except for two isolates that showed intermediate susceptibility to the latter. However, susceptibility of the isolates to newer classes of antibiotics was also observed. The overall prevalence rate was 7.14% and confirmed the presence of enterohemorrhagic E. coli O157 in native cattle in Cavite. This showed that native cattle is a source of the pathogen.
Key words: enterohemorrhagic E. coli, multidrug resistance, native cattle, virulence