A study was conducted to examine sources of variation introduced into a phagocytosis assay as a result of the isolation of neutrophils from bovine blood, including variation attributable to isolation of neutrophils from blood, variation between duplicate determinations of percentage phagocytosis, and the variation in the ability of neutrophils isolated from blood (over repeated collections from the jugular vein) to phagocytose. For the phagocytosis assay, jugular venous blood from each of 4 cows was divided into 2 equal portions. The neutrophils were isolated by lysis of red blood cells with 0.2% sodium chloride. The neutrophils (2 X 10(7)) were incubated in duplicate with 32P-labeled Staphylococcus aureus ([32P]SA; 2 X 10(8)) inskimmed milk samples (2.5% final concentration) prepared from 4 cows. This process was repeated thrice on neutrophils isolated from 4 cows at 2-week intervals. The proportions of variation in percentage of 32P-labeled S aureus phagocytosed between duplicate neutrophil isolations and between duplicate assay determinations were 0 and 1%. Differences among skimmed milk sources and among runs, using blood neutrophils taken at different times from the same donor cow, accounted for 62 and 36% of the total variation. The results indicated that variation arising from blood neutrophil isolation introduced into a phagocytosis assay within a single-day trial is of no concern. The large variation among skimmed milk sample sources indicated differences among cows in the ability of their milk to support phagocytosis. The variation in neutrophil isolations over time for any cow was considered too large to allow for evaluation of physiologic and environmental effects on phagocytosis of neutrophils isolated from blood.

The present study was conducted to investigate the Bordetella bronchiseptica infection in Youngnam swine herds during the period of August 1986 to July 1987 and some properties of the organisms isolated from these Korean swine. B. bronchiseptica was recovered from 25 of 70 (35.7%) growing pigs of 4 to 10 weeks of age and from 12 of 13 (92.3%) herds. From 115 slaughter pigs, 58(50.4%) pigs were culture positive and the pigs from 13 of 14 (92.9%) herds were found to be infected with B. bronchiseptica. The majority of biochemical and cultural properties of B. bronchiseptica isolated from Korean swine were identical to those of the standard strain employed and some 97.6% of the isolates showed the characters of phase I organism on primary isolation.

The first outbreak of aujeszky's disease (AD) was identified from piggery located at the southern part of Korea in July, 1987. This piggery suffered from a significant economic loss caused by unexpected piglet mortality and reproductive failure. Etiologic viral agents were isolated from tonsil and spleen of the infected piglets, and the isolates produced a typical cytopathic effect of herpesvirus with giant cell formation when inoculated in many different cells. Subsequently the field isolates were characterized as suid herpesvirus I by cross-neutralization test and indirect fluorescence assay utilizing specific monoclonal antibody, and proved to be a pathogenic strain of AD virus(ADV).

Mating experiments were performed to elucidate the distribution of perfect state of Microsporum gypseum complex originating from animals and soils in Korea. A total of 30 strains of M. gypseum complex, composed of 16 from animals and 14 from soils, mated with the tester strains of Nannizzia incurvata, N. gypsea and N. fulva. Among 30 strains of M. gypseum complex examined, 16 strains (53.3%) were N. incurvata, 13 strains (43.3%) N. gypsea and 1 strain (3.3%) N. fulva. Among 13 strains of dog isolates, 8 strains (61.5%) were N. incurvata and 5 strains (38.5%) N. gypsea. And each strain isolated from Korean native goat, monkey and albino rat was N. gypsea. Among 14 strains of soil isolates, 8 strains (57.2%) were N. incurvata, 5 strains (35.7%) N. gypsea and 1 strain (7.2%) N. fulva. And - mating type was more frequently obseved than + mating type in the strains of N. incurvata and N. gypsea. By this study, N. fulva was isolated the first time in Korea.

This paper deals with the distribution of Salmonella (S) infection on 4 herds in Kyungju and Taegu during the period from May to October 1986. Isolated Salmonella were examined for serotypes, antimicrobial drug resistance and detection of R plasmid. From 4 herds, 67 Salmonella were isolated from 51 samples (1.1%), and their serovar strains were S. typhimurium 6, S. derby 5, S. infantis 4, S. bareilly 4, S. dublin 3, S. anatum 2, S. montevideo 2 and untypable 41. In 4 herds, the incidence of drug resistance was 57.7-100% and transfer frequency of conjugative R plasmid was 96.1-100%.