This paper deals with the isolation of Salmonella on 3 herds during the period from May 1984 to May 1985. Isolated Salmonella were examined for serotypes, adhesive fimbriae, antibiotic susceptibility and detection of R plasmid. Of total 1505 cattle, 24 Salmonella were isolated from 18 cattle (1.2%) and their serotypes were S. enteritidis (9 strains), S. derby (4 strains), S. infantis (1 strain), C1 group (8 strains), C2 group (1 strain) and untypable (1 strain). Twelve strains of Salmonella were isolated from 227 cattle with diarrhea and their serotypes were S. enteritidis (4 strains), S. derby (3 strains), S. infantis (1 strain), C1 group (3 strains) and untypable (1 strain)

The purpose of this study was the examination for presence of K99 antigen (K99), enterotoxigenicity, 0-groups, colicin and antibiotic susceptibility among E. coli isolated from calves and cows. A total of 49 (18.7%) among 262 strains, isolated from 30 (26.5) out of 113 calves and cows, possesed K99, and thirty three of 49 K99+ strains produced ST. Of the strains of diarrheal calf origin which less than 15 days old, a high correlation was observed between enterotoxigenic ability and K99: 92.3% of the K99+ strains produced heat stable enterotoxin (ST)

Isolation and identification of mycoplasma were performed to clarify mycoplasma infection of mice fed by convectional feeding at two (K1, K2) institutes in Korea. The twenty mice to be tested were randomly samples from each of 10 breeding colonies in respective institute. Identification of the mycoplasma strains isolated from the nasal cavity, lung and synovia of mice was made according to the morphology of colonies, biological and biochemical properties with special reference to M. pulmonis, M. arthritidis and M. neurolyticum

This paper deals with the incidence of antibiotic resistance and of R plasmids in 319 Salmonella strains isolated from various samples on 7 piggeries in Taegu, Kyongbuk, Kyongnam and Chungnam and a slaughter house in Taegu during the period from May, 1984 to May, 1985. Of the 319 strains examined, 250 (78.4%) were resistant to one or more antibiotics such as ampicillin (Am), chloramphenicol (Cm), gentamicin (Gm), kanamycin (Km), sulfadimethoxine (Su), streptomycin (Sm), rifampicin (Rf) and tetracycline (Tc), and higher resistant to Su (74.9%), Sm (53.0%) and Tc (28.5%). Only two Salmonella strains isolated from A and C farms were resistant to Rf and Gm, respectively

Sprague-Dawley rats received subcutaneous injections of gentamicin sulfate, 50 and 100mg/kg for 3, 7 and 10 days. The hematological and blood chemical values were determined. Kidneys were examined histologically and ultrastructurally. The serum values of aspartate transaminase, blood urea nitrogen and creatinine in the rats administered gentamicin, 50 and 100mg/kg/day were significantly increased than those in the control. The ratio of kidney weight to body weight was significantly increased in the rats injected gentamicin, 100mg/kg for 10 days than those in the control

This paper deals with the incidence of bovine mastitis for 743 quarters and distribution of Staphylococci for the quarter and 70 bulk milk samples in the northern area of Kyongbuk during the period from Jan to Dec 1984. Isolated Staphylococci were examined for species, subgroups, antibiotic resistance and penicillinase production. A total of 25 (73.5%) of 34 herds, 102 (54.3%) of 188 cows and 208 (30.3%) of 743 quarters were found to be infected with subclinical mastitis. A total of 83 (83.1%) of 102 cows, 94 (45.2%) of 208 mastitic quarters and 55 (78.6%) of 70 bulk milk samples were isolated Staphylococci