A total of 593 mastitic pathogens was isolated from the clinical mastitic milk of dairy cattle in Kyonggi area from March 1984 to February 1988. The mastitic pathogens were further studied bacteriologically and examined for susceptibility patterns to 10 antibiotics. 173 pathogens were isolated in the first year of studies, 205 pathogens in the second year, 122 pathogens in the third year and 93 pathogens in the last year. The pathogens isolated from clinical mastitis were more in summer than other seasons. Staphylococcus spp (50%) and Streptococcus spp (18%) were the main pathogens in the first year of studies but coliforms (15%) and other bacteria (40%) were the main pathogens in the last year of studies. Coliform mastitis occurred only in summer and autumn. Antibiotic susceptibility patterns of the same genuses from clinical mastitis infections in different herds and in different years varied greatly. Therefore, treatment should be selected on the basis of susceptibility test results

A porcine parvovirus inactivated vaccine was prepared and inoculated to 7 piglets and also 8 guinea-pigs, and their serum antibodies were titrated. Twenty-two field serum samples of unvaccinated sows were also tested by SN and HI methods. It was observed that SN test was superior over HI test. Therfore, it is suggested that the SN test could well be used in the detection of serum antibody for PPV in vaccinated pigs

The present study was done to demonstrate ADV antigens in frozen and paraffin sections from ADV-infected pigs and cell cultures by using of the IGS method. Tissue specimens from 3 young pigs infected with ADV-phylaxia strain and of 2 healthy pigs were used. Fibroblastic cells originated from pig brain and BHK cells were grown and confluent monolayers were infected with the virus. Two monoclonal antibodies and a specific hyperimmune serum to ADV were used as the source of primary antibodies for both the IGS and immunoperoxidase methods. Application of the IGS method yielded a black fine granular reaction in positive areas, and the results were superior to those obtained using the immuno-peroxidase technique for all cases tested. The IGS method might be useful in the detection of various viral antigens in tissue sections

Twenty-eight porcine rotavirus were isolated from piglets with diarrhoea in Chonnam Province. According to the age, 41 to 60 day old pigs showed the highest isolation frequency among the post weaning pigs. The characteristics of the field isolates were determined by electronmicroscopy(EM), immunofluorescent assay(FA), and electrophoretic migration patterns of the genome profiles. Some of the isolates showed remarkable haemagglutination activity against rabbit and dog erythrocytes, ranging from 4 to 2848, respectively. At least 3 serotypes of porcine rotavirus were recognized by serum neutralization test using serotype specific rotavirus hyperimmune sera

The present study was carried out to investigate the serum enzyme activities of racehorses. The enzymes investigated were aspartate and alanine aminotranserase (GOT, GPT), gamma-glutamyl transpeptidase(gamma-GTP), Lactic dehydrogenase(LDH), creatine phosphokinase(CPK), and alkaline phosphatase(ALP). Animals used were 30 healthy racehorse(female 17, male 13) average weighing 435kg and were from 2 to 8 years of age. LDH activity was progressively decreased with age and next in the order of GOT and CPK activities. GOT and gamma-GPT activities were not changed with age but ALP activity tended to be decreased with age. Activities of GOT, GPT, gamma-GTP and ALP were higher in female than in male. There was no difference in CPK activity by sex, and no difference was found out among breeds

This study was conducted to isolate etiological agents from the 103 scouring piglets in Kyongnam area and also carried out antimicrobial drug susceptibility test and epidemiogical survey. The incidence of scouring piglet was most prevalent in 81.6% at the age of 2 to 4 weeks after birth, while the rate was less than 10% at the age of 5 to 6 weeks and under 1 week after birth. When comparing the isolation frequency of each etiological agent, enteropathogenic E. coli was most prevalent in 46.6%, thermophilic Campylobacter in 26.2% and Salmonellae was in 8.7% in that order. In the OK serotyping for 117 isolates of enteropathogenic E. coli, type 0141 : K85(20.5%), 0157:K88ac(14.5%), 0138:K81 and 0149:K91 (13.3%) were encountered most frequently. In the biotyping for 27 isolates of thermophilic Campylobacter, most strains of C. jejuni belonged to type I (50.0%) and II (25.0%), and most strains of C. coli belonged to biotype I (78.9%). In the serotyping for 9 strains of Salmonellae, 3 strains were grouped as D, 2 strains as C and 1 strain each was group B and E. The other 2 strains were untypable. The 117 isolates of enteropathogenic E. coli were resistant more than 90% to erythromycin, penicillin, tetracycline and streptomycin, whereas about 90% of the isolates were sensitive to kanamycin and gentamicin. In the case of Salmonellae, all of the isolates were resistant to penicillin, but about 89% of the isolates were sensitive to gentamicin and colistin. All of C. jejuni and C. coli isolates were resistant to cephalothin, but more than 89% of C. jejuni and C. coli were sensitive to kanamycin and gentamicin

This paper deals with the 0 groups of citrate utilizing variants of Escherichia coli (Cit+ E. Coli) isolated from cattle, the production of colicin, hemolysin, K99 antigen, heat stable enterotoxin, and the isolation of plasmid DNA. Among 42 Cit + E. Coli, 12 strains were 020, 9 strains 08, 5 strains 045, 3 strains 0115, 1 strain 064, 1 strain 0139 and remaining strains (11) were untypable. Thirty-nine(81.3%)out of 48 Cit + E. Coli produced colicin and 13(27.0%) produced hemolysin. Of 12 cit + E. coli bearing K99 antigen, 6(50.0%) produced heat stable enterotoxin. In gel electrophoresis for the isolation of plasmid DNA, the number of plasmids varied from 1 to 7 in 10 Cit+ E. Coli. Its molecular weight ranged from 2 to 50 Mdalton, and 50 Mdalton plasmid commonly existed in all strains

Light-microscope studies of the coccidial organisms found in the Bursa fabricii from chickens showing some specific signs were carried out, and the etiological agent was estimated as the parasite belonging to the Family Cryptosporiidae. The specific gross pathological signs were intestinal hemorrhage and atrophy of the Bursa fabricii and hyperplasia was associated with the presence of organisms attached to the epithelial cells lining the plicae of the bursa of Fabricius in the microscopical findings

To establish a laboratory animal model for study on development of diagnostic methods for infectious bovine rhinotracheitis virus(IBRV), experimental infection of the virus to rabbits immunosuppressed with dexamethasone(DX) were carried out. When lymphocyte activity was measured by lymphocyte transformation to phytohaemagglutinin parallel with total and differential leucocyte counting, both groups treated with 2.0mg DX once and 1.0mg DX daily showed marked immunosuppression between 5 to 72 hrs. after administration. The degree of suppression of lymphocyte activities was more remarkable in the latter group. IBRV PQ7 strain at 10** (7.5) TCID50/0.2ml was inoculated into conjunctival sacs of rabbits immunosuppressed with DX and non-treated. During 3 weeks observation, the immunosuppressed groups revealed mild conjunctivitis, viremia and virus recovery by 33.3 to 100%, whereas the DX nontreated group showed viremia and virus recovery with no clinical conjunctivitis in one of three rabbits(33.3%). In conclusion, it was indicated that experimental infection of IBRV PQ7 strain to rabbit was limited in prerequisite to immunologic modification by administration of immunosuppressive drugs

The present study was carried out to investigate C. jejuni and C. coli in chicken. Also were examined the pathogenicity of the isolates in chicks by experimental inoculation. Thermophilic Campylobacter were isolated from 34 (45.9%) of the 74 specimens, and classified as 21.6 % C. jejuni, and 24.3 % C. coli. In the biotyping of 16 strains of C. jejuni isolates, 37.5 % of the strains were grouped as biotype I, 62.5 % as biotype II. In the case of 18 strains of C. coli isolates, 49.9 % of isolates were grouped as biotype I, 55.6 % as biotype II. In oral inoculation with 10** (4)cfu of Capmylobacter isolates into infant chicks (1 to 3 days-old), 17 days-old and 34 days-old chicks, 32.5 % of the chicks developed diarrhea on day 1, 52.5 % on day 3, 70.0 % on day 5, and 27.5% on day 7, and the peak incidence of diarrhea was reached on day 5. The organisms were found to be discharged in feces one day afterwards. C. jejuni and C. coli strains were detected from the feces in 87.5 % of the chicks on day 5.