The reproductive tracts have an intimate relationship with reproduction because there are bacterial communities that can affect reproductive health. The differences in the bacterial community of periparturient dairy cows were investigated. Vaginal and fecal samples were collected seven days before and after calving, and DNA was extracted to sequence the V3-V4 regions of the 16S rRNA genes. In the postpartum vaginas, operational taxonomic units, Chao1, Shannon, and Simpson were decreased, and phyla Fusobacteria and Bacteroidetes were increased. In summary, bacterial abundance can affect the periparturient biological differences in dairy cows, suggesting a susceptibility to infection within one week after calving.

Paratuberculosis caused by Mycobacterium avium subsp. paratuberculosis (MAP) has extended latent periods of infection. Due to this property, difficulties in the detection of fecal shedder have been raised. A newly designed method for DNA extraction from fecal specimens, mGITC/SC was evaluated in terms of diagnostic efficiency. The detection limit of IS900 real-time PCR was about 50 MAP (1.5 cfu) in 250 mg of feces (6 cfu per g). Also, this DNA extraction method was faster and cheaper than that using commercial kit or other methods. Consequently, the mGITC/SC is an economical DNA extraction method that could be a useful tool for detecting MAP from fecal specimens.

To investigate the epidemiological trait of intestinal diseases of animals caused by thermophilic Campylobacter spp., isolation of etiological agent was carried out. Isolated Campylobacter spp. were biotyped, serotyped and the susceptibility of the isolates to antimicrobial agents were examined. Isolation rates of Campylobacter spp. from 649 fecal materials of 208 cattle, 300 pigs and 141 chickens were 25.5 %, 23.7 % and 38.3 %, respectively. The majority of the 130 isolates of C jejuni was classified as biotype I (50.6 %) and biotype II (34.6 %). Most of the 46 isolates of C coli were biotype I (71.7 %). Isolated C jejuni strains showed 14 different serotype, and serotype 4, 26, 36 were most frequent. Isolated C coli strains showed 5 different serotype and serotype 31 and 21 were relatively common. Isolated Campylobacter spp. were highly susceptible to nalidixic acid, amikacin, gentamycin, colistin and chlorampehnicol

To investigate the epidemiological trait of intestinal diseases of animals caused by thermophilic Campylobacter spp., isolation of etiological agent was carried out and the profiles of plasmids and the transfer of resistance plasmid in the isolated Camplyobacter spp. were examined. A total of 110 isolates of C jejuni and C coli were subjected to the test for the presence of plasmid DNA. Of the isolates examined, 60 % of the isolates were noted to harbor plasmid DNA. Plasmid occurrence rate from pigs, chickens and cattle were 76.2 %, 61.7 % and 37.7 %, respectively. The plasmids of a large molecular weight, ranging from 36 Md to 86Md, were identified with the strains of tetracycline resistant. Transfer frequency of tetracycline resistant plasmids was higher in the case of the filter mating method than in the broth mating method by the factor of 10-1,000. Tetracycline resistant plasmids of C jejuni were transferarble to C jejuni and C coli by conjugation. In a low frequency, the transfer of tetracycline plasmid was also possible to Vibrio parahemolyticus. However, it was impossible to transfer to Streptococcus fecalis, E. coli and Vibrio cholerae. Tetracycline resistant plasmids of C jejuni were impossible to transfer to Campylobacter spp. and related bacteria by transformation

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.

A survey on the prevalence of internal parasites in the laboratory rats in the Chonnam and Kyonggi areas was carried out. A total of 208 rats was selected for necropsy and the parasites were collected from the organs and the fecal samples. The infection rate of the internal parasites was high as 63.9 % and eight species of parasites were identified. Among the species identified A tetraptera (21.6 %) and H diminuta (20.7 %) appeared with relatively higher infection rates than any other species identified. A significant difference in numbers of parasites was recognized between the regions as 8 species in Chonnam and 4 species in Kyonggi. The laboratory rats reared in stainless steel cage showed the higher infection rate than those in polycarbonate cage, with some exception in H spumosa and H nana. In this survey T crassicauda was firstly in the laboratory rats in Korea

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