Antimicrobial resistance is one of the most concerns in pig industry. Escherichia (E.) coli have been used for the indicator to monitor the antimicrobial resistance. In this study, 321 E. coli from diarrheic and non-diarrheic piglets were tested for antimicrobial resistance and frequency of Bla∧TEM. In non-diarrheic piglets, they were resistant to oxytetracycline (93%), streptomycin (92%) and sulfadiazine (90%) but susceptible to ceftiofur (99%), colistin (97%), and enrofloxacin (82%). The isolates from diarrheic piglets were resistant to enrofloxacin (72.9%), ceftiofur (17.6%), and colistin (11.3%), whereas the resistance was 1%, 18% and 3% in case of non-diarrheic piglets, respectively. The resistance for amoxicillin/clavulanic acid (54.1%) and ceftiofur (22%) was high in isolates from post-weaning piglets. The resistance for colistin was 15.2% in nursery piglets. Seventy-three percent of isolates from diarrheic piglets showed high multidrug resistance profile (more than 13 antimicrobials) compared to those from non-diarrheic pigs in which 71% of isolates showed moderate multidrug resistance profile (7 to 12 antimicrobials). The frequency of Bla∧TEM in E. coli from non-diarrheic and diarrheic piglets was 57% and 69%, respectively. The results might provide the basic knowledge to establish the strategies for treatment and reduce antibiotic resistance of E. coli in piglets.

Bovine viral diarrhea (BVD) is very important disease in cattle industry with a worldwide distribution. Detection and elimination of persistently infected calves with bovine viral diarrhea virus (BVDV) was valuable strategy for BVD eradication because those calves were main source for transmission. We surveyed persistent infection with BVDV by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) using whole blood and skin. Five hundred thirty nine Korean native calves were tested. Four calves (0.7%) were positive for BVDV antigen for both tests.

A 2-years-old female domesticated mouflon with a clinical history of chronic diarrhea and emaciation was submitted to NVRQS. Grossly, there were severe thickening of small intestine wall and enlargement of mesenteric lymph nodes. Microscopically, severe granulomatous inflammation was found in small and large intestine, mesenteric lymph nodes, spleen and liver. By Ziehl-Neelsen stain, innumerable acid-fast rod bacteria were found in the cytoplasm of epitheloid and Langhans type giant cells present in these organs.

The purpose of this study was to evaluate effect of chitosan-oligosaccharides(CHIOL) on hydrophobicity of pathogenic E coli including a field isolate from suckling piglet with diarrhea, E coli-0157:H7, and E coli-O149:K88ac. E coli field isolate appeared adhesion of 100% to n-hexadecne between 0.00125% and 0.05% CHIOL. E coli-O157:H7 occurred adhesion of 69% and 64% under the level of 0.00125% and 0.025% CHIOL, respectively. E coli-O149:K88ac showed adhesion of 100% in higher than 0.025% CHIOL. For cationic action, the adhesion of E coli isolate and E coli-O149:K88ac to n-hexadecane were inhibited at level of higher than 10mM Ca2+ but did not induce any difference among the concentrations used(p0.01). However,the adhesion of E coli-O157:H7 to n-hexadecane was inhibited at level of higher than 50mM Ca2+. In a field trial, control piglets showed average mortality of up to 58% during 3 days after the onset of diarrhea. In contrast, the prevalence of E coli-induced diarrhea in CHIOL-treated groups without mortality was dropped down to average 34% on the 1st day after the treatment of CHIOL, and average 2% on the 4th day. After then, piglets with diarrhea was not present. In conclusion, the low concentrations of CHIOL were most likely to associate with the enhancement of hydrophobicit to pathogenic E coli. Calcium inhibited the hydrophobicity of E coli by CHIOL. These results suggested that CHIOL could be played an efficient and reliable role in treating enteric colibacillosis of piglets.

Detection and distribution of bovine biral diarrhea virus(BVDV) was studied in formalin-fixed, paraffin-embedded tissues from two naturally infected cattle by in situ hybridization with a non-radioactive biotinylated probe. A 600 base pair cDNA probe from BVDV B-25 strain ws used for probe. The whole procedure of ISH to diagnose was carried out within 1~2 hours in MicroprobeTM capillary action system. The biotin-labelled probe was demonstrated after hybridization under standard conditions by the application of streptoavidin and biotinylated alkaline phosphatase. Alkaline phosphatase was visualized using a fast red TR/naphthol phosphatase and the sections were counterstained with hematoxylin. We have obtained the result of positive reactions in digestive tract(sm1.all intestine and colon) and epidermis of tongue in the state of the intract tissues. The result suggested that in situ hybridization method can be considered as a useful diagnostic technique for detection of specific nucleic acid sequences of BVDV.