양돈장(養豚場)에 있어서 Salmonella감염증(感染症)의 역학적(疫學的) 연구(硏究) : I. 발생(發生) 및 오염상황(汚染狀況), 혈청형(血淸型)과 Salmonella typhimurium의 생물형(生物型)

Epizootiological Study of Salmonella Infection on Piggery: I. Study on Distribution, Occurrence, Serovars and Biovars

This paper deals with the distribution, reservoir and mode of spread of salmonella infection on 7 pig farms in Taegu, Gyeongbuk, Gyeongnam and Chungnam and a slaughter house in Teagu during the period from May 1984 to May 1985. Isolated salmonella were examined for serotypes and biotyping of S. typhimurium. The results obtained were summarised as follows; 1. Of total 7,995 samples from 7 pig farms and a slaughter house, 319 salmonella were isolated from 234 samples (2.9%) and their serovar strains were S. derby 77, S. infantis 41, S. enteritidis 20, S. typhimurium 18, S. bredeney 16, S. london 14, S. paratyphi B 9, S. anatum 8, S. montevideo 8, S. senftenberg 7, S. thompson 6, S. pullorum 4, S. paratyphi A 1 and untypable 70. 2. The incidence rate of diarrhea of piglets, weaned pigs and fattening pigs was 9.8%, 2.3% and 0.5%, respectively whereas the rate by salmonella infection was 4.2%, 1.2% and 11.3%, respectively. 3. The isolation rate of salmonella was higher in summer and autumn. 4. The isolation rate of salmonella varied from 1.1% to 4.5% in 7 pig farms, it was higher in sewages(4.4%), weaned pigs(3.7%), boars(3.7%) and other(3.7%) included soils, manure and wild rats according to samples. Three out of 7 pig farms were contaminated heavily with various serovars of salmonella. 5. The isolation rate of salmonella from pigs slaughtered was 8.1%, it was 13.6% in rectal contents and 1.6% in mensenteric lymph nodes. 6. Eighteen strains of S. typhimurium were classified into 3 different biovars(1, 10 and 10a) by the method of Brandis and were subdivided into 6 different full biovars(1a, 1d, 1dh, 3d, 26i and 26ei) by the method described by Duguid et al. Appearance of different biovars indicated the occurrence of different exotic infection sources on the farms.