최근 경북지역의 양계농장에서 발생한 salmonellosis의 역학적 특성

Epidemiological properties of salmonellosis of poultry farms in Kyongbuk province at recent year

The present study was conducted to investigate the epidemiological properties of salmonellosis of poultry farms in Kyongbuk province during the relied from November 1998 to November 1999 And antibiotic susceptibility and biochemical characteristics of 120 Salmonella cultures isolated from chicken samples were also investigated. The results obtained through this study were summarized as follows, 1. Among 667,200 chickens of 31 flocks in 17 layer farms and 9 broiler farms, 61,350 chickens of 31 flocks were died with salmonellosis. The death rate of 25 farms varied from 0.1% to 75.0%, and the average death rate was 9.2%. 2. According to etiological agents, fowl typhoid was shown the most predominant outbreak among the salmonellosis during a year, which accounted for 8R.0%(22/25) of the total case 3. The serotypes of 120 Salmonella isolates were identified as 7 strains(5.8%) of S pullorum, 10 strains(8.4%) of S typhimurium and 103 strains(85.8%) of S gallinarum. 4. Most outbreak of fowl typhoid were prevalent on the layer chicken farms(77.1%), and the summer season(45.5%) also appeared the most hazardous season during the year. 5. It seemed that the Hyline breed(70.6%) was the most susceptible among the layer chicken breeds, and followed by Isabrown(23.5%), Tetra(5.9%) in order. 6. In layers, 76.4% of fowl typhoid occurred commonly from 14 to 40 weeks including the early laying peroid, but in broiler farms, all cases was outbreak within first second weeks. 7 All the strains of S pullorum were resistant to lincomycin(Lm), penicillin(Pm), and steptomycin(Sm), but sensitive to amikacin(Ak), ampicillin(Am), cephalothin(Ce), ciprofloxacin (CiP), chloramphenicol(Cm), colistin(Co), enrofloxacin(Enr), furazolidone(Fu), gentamicin(Gm), kanamycin(Km), neomycin(Nm), polymyxin(Po), and teracycline(Tc). All the strains of S typhimurium were resistant to Lm(100%), Pm(100%), Po(90%), and Sm(90%), but were sensitive to Ak, Am, Ce, CiP, Cm, Co, Enr, Fu, Gm, Km, Nm, and Tc. 8. Minimum inhibitory concentration(MIC) of 103 strains of S gallinarum were also evaluated and their patterns were much more variable than others. All the strains of S gallinarum were sensitive to Ak, Am, Ce, Cip, Cm, Enr, Fu, Km, and Nm, but resistant to Lm(100%), and Sm(100%), 99(96.1%) to Co, 83(80.6%) to Pm, and 83(80.6%) to Po, 55(53.4%) to Gm, and 33(32.0%) to Tc. 9. The multiple drug resistance patterns of 120 Salmonella strains were CoLmPmPo Sm pattern(34.2%), CoGmLmPmPoSmTc(20.8%), CoGmLmPmPoSm(13.3%), CoGmLmSm(7.5%), LmPmSm(7.5%), LmPm(6.7%), CoLmSmTc(3.3%),, CoGmLmSmTc(1.7%), GmLmSmTc(1.7%), CoGmLmPoSm(0.1%), LmPmPo(0.1%), CoLm Sm(0.1%), and LmSm(0.1%), in order.