The mosquito-borne pathogen Zika virus may result in neurological disorders such as Guillain-Barré syndrome and microcephaly. The virus is classified as a member of the Flaviviridae family and its wide spread in multiple continents is a significant threat to public health. So, there is a need to develop animal models to examine the pathogenesis of the disease and develop vaccines. To examine the clinical profile during Zika virus infection, we infected neonatal and adult wild-type mice (C57BL/6 and Balb/c) and compared the clinical signs of African-lineage strain (MR766) and Asian-lineage strain (PRVABC59, MEX2-81) of Zika virus. Consistent with previous reports, eight-week-old female Balb/c mice infected with these viral strains showed changes in body weight, survival rate, and no neurologic signs, but demonstrated increases in the weights of spleens and hearts. However, one-day-old neonates showed significantly lower survival rate and body weight with the African-lineage strain than the Asian-lineage strain. These results confirmed the pathogenic differences between Zika virus strains. We also evaluated the clinical responses in neonatal and adult mice of different strains. Our findings suggest that these are useful mouse models for characterization of Zika virus for vaccine development.

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.

In order to know the comparative histological structure of the tongue of some domestic and laboratory animals, the root of the tongue has been investigated by light microscopy. The filiform papillae were mainly distributed in the root of the tongue of most animals and many foliate papillae were also found in the dog and rabbit. The very well-developed mucosa was found in the cattle and in the dog, fowl, rat and mouse was fair. The lamina propria was well developed in the cattle, dog and pig. The muscle layer was well developed in the cattle. The adipose tissue which distributed between the muscle fibers was mainly found in the dog