The purpose of present study was to investigate the antimicrobial resistance in Escherichia coli isolated from healthy animals in all provinces of the Republic of Korea. A total of 2,085 E. coli strains isolated from 11,336 fecal samples of healthy animals during 2010-2012 were examined for antimicrobial resistance. Comparison of average resistance rate through the years revealed that tetracycline (47.0% and 76.1%) and streptomycin resistance (42.6% and 64.6%) was most frequently observed in cattle and pigs, respectively. Whereas, in chicken isolates, resistance against nalidixic acid (90.9%) was highest among the antimicrobials tested. Percentage of E. coli that showed multidrug resistance (resistance against¡� three subclasses of antimicrobial agents) was 17.6% (151/860) in cattle, 69.4% (506/729) in pigs, and 86.1% (427/496) in chickens. Overall, the rates of resistance are apparently different between animal species and, in particular, resistance was less prevalent in cattle than in pigs and chickens. In conclusion, this study showed higher prevalence of resistance in commensal E. coli strains to antimicrobial agents in Korean livestock and highlighted the urgent need for measures to regulate the abuse of antimicrobial agents.

Bovine enteroviruses (BEVs) were separated into two groups, BEV-1 and BEV-2. BEVs, found in cattle worldwide, usually cause asymptomatic infections and are excreted in the feces of infected animals. Antibodies against BEV have been found in different species including human, cattle, sheep, goats, dogs, horses and monkeys in the world. This study aimed to investigate prevalence of the neutralizing antibodies for BEVs in human and animals in Korea. Antibodies against BEV-1 in humans, cattle, pigs, goats, horses and dogs were shown to be 46.8%, 48.3%, 70.6%, 11.5% and 6.3% respectively. Also, antibodies against BEV-2 were shown to be 98.7%, 68.1%, 89.2%, 59.4%, 9.4% and 96.9% respectively. We found that the neutralizing antibodies against these viruses are common in Korea. The prevalences of antibodies against BEV-1 were lower than those against BEV-2 in humans and in all animals except horses. These results showed that the BEV is considered endemic in cattle in many regions in Korea.