초록 ▼

□ 돼지 장내 spirochetes 감염증 조사
○ Brachyspira spp. 배양법 확립
- 야외가검물로부터 Brachyspira spp.를 분리하기위해 항생제가 함유된 4종의 선택배지를 이용하여 B. hyodysenteriae와 B. pilosicoli의 최적 배양 조건 확립.
○ PCR 기법 확립
- Duplex PCR : B. hyodysenteriae의 nox gene과 B. pilosicoli의 16S rRNA gene 을 증폭하여 B. hyodysenteriae와 B. pilosicoli의 동시

□ 돼지 장내 spirochetes 감염증 조사
○ Brachyspira spp. 배양법 확립
- 야외가검물로부터 Brachyspira spp.를 분리하기위해 항생제가 함유된 4종의 선택배지를 이용하여 B. hyodysenteriae와 B. pilosicoli의 최적 배양 조건 확립.
○ PCR 기법 확립
- Duplex PCR : B. hyodysenteriae의 nox gene과 B. pilosicoli의 16S rRNA gene 을 증폭하여 B. hyodysenteriae와 B. pilosicoli의 동시 진단 가능.
- Brachyspira spp.의 nox gene을 이용하여 진단.
○ Brachyspira spp. 분리
- 31농가 58개의 설사분변 및 장병변을 검사한 결과 4개 농가에서 4주의 돈적리의 원인균인 B. hyodysenteriae 를 분리.
- 19개 양돈장으로부터 채취한 299개의 분변을 검사한 결과11개 농가에서 Brachyspira spp. 37주를 분리하였음.
○ 15주의 Brachyspira spp. 분리주에 대한 생물학적 특성 검사 : Hemolysis, indole, hippurate hydrolysis 검사 결과, 4주의 B. hyodysenteriae는 Brachyspira spp.의 group I, 37주의 Brachyspira spp.는 group Ⅲ로 분류
□ 돼지 주요 병원성 세균 분포도 조사
○ 병원성 대장균 검사
- 1개 이상의 병원성인자를 생산하는 대장균을 86주 분리하였으며, 병원성인자 중 EAST1이 가장 높은 빈도로 분포하였음
○ Salmonella spp. 분리 동정
- 9개 농가로부터 16주의 Salmonella spp 분리
○ 돼지증식성장염 분포도 조사(PCR법)
- 20개 농가 268시료 중 11농가 49시료가 양성
○ Brachyspira spp. 분리 및 grouping
- 전체시료 중 6개 농가에서 15주의 Brachyspira spp.((group III) 분리
○ 병원성 대장균의 혈청형 동정
- 86주의 병원성인자를 산생하는 대장균는 다양한 혈청형 분포를 나타내었으며, 이 중 O8, O112ac, O20, O123이 비교적 높은 빈도로 분포하였음
○ 분리주에 대한 약제 감수성검사
- 대장균과 살모넬라 모든 균주가 tetracycline에 내성을 나타내었으며 그 외 ampicillin과 streptomycin에 높은 내성을 나타내었음.

Abstract ▼

Enteric bacterial infections are among the most common and economically significant diseases affecting swine production worldwide. Clinical signs of these infections include diarrhea, reduced growth rate, weight loss, and death of preweaned, weanling, grower-finisher, young and adult age breeding an

Enteric bacterial infections are among the most common and economically significant diseases affecting swine production worldwide. Clinical signs of these infections include diarrhea, reduced growth rate, weight loss, and death of preweaned, weanling, grower-finisher, young and adult age breeding animals. The most common etiological agents include Escherichia coli (E. coli), Clostridium perfringens, Lawsonia intracellularis (L. intracellularis), Salmonella spp., and spp. The purpose of this study was to investigate the prevalence of enteric pathogens and the characterization of isolates in Korea. Between June 2003 and December 2004, 62 rectal swabs and intestines from diarrheic pigs and 299 rectal swabs were taken from 31 and 19 farms, respectively. Forty-two Brachyspira spp. were isolated, 4 beta-hemolytic isolates obtained from four diarrheic farms were identified as B. hyodysenteriae, and 37 isolates from 11 other farms were identified as Brachyspira spp.(Group III). Pathogenic Brachyspira spp. and non-pathogenic Brachyspira spp. were present on 12.9%, 52.65% of the clinical farms and control farms, respectively. Four B. hyodysenteriae isolates were susceptible to ciprofloxacin, clindamycim, penicillin, tetracycline, tiamulin, while resistant to erythromycin and tylosin. The prevalence of B. hyodysenteriae in Korean herds and pigs appear lower than other that reported in other counties, and this may be due to susceptible to antimicrobials which used in pig farms in Korea.
Between January and December 2005, 62 rectal swabs and intestines from diarrheic pigs and 341 rectal swabs were taken from 41 farms. We investigate the prevalence of enteric pathogens and the characterization of isolates. A total of 86 E. coli isolates produced one or more potential virulence factors. Of the virulence factors, the EAST1 gene was detected in 49 (32.5%), and the F4, LT, ST gene were detected in 5, 13, 11 isolates from diarrheic pigs, respectively. Especially F4, LT and ST were frequently occurred in diarrheic fecal samples of the neonate. Among the 86 pathogenic isolates, strains expressing EAST1(n=57), ST+EAST1(n=4), F4+LT+EAST1(n=4), and F4+ST+EAST1(n=4) occurred more frequently. The relationship between serotypes and virulence factor genes was observed. Serogroup O8, O112ac, O20, O123 were frequently observed in pathogenic E. coli isolates. The high levels of antimicrobial resistance were observed in tetracycline(100%), ampicillin(83.8%), streptomycin(83.8%) in pathogenic E. coli isolates. The overall herd prevalence of L. intracellularis, Brachyspira spp. and Salmonella spp. were 38.9%, 8.0% and 27.2%, respectively. Also, the prevalence of L. intracellularis, B. hyodysenteriae and Salmonella spp. among all sampled pigs were 33.9%, 2.0% and 6.0%, respectively. This study suggested that herds positive for L. intracellularis, pathogenic E. coli. were distributed throughout Korea.

목차 Contents

• 수의과학기술개발연구사업 연구과제 최종보고서 ... 1
• I. 연구배경 및 목표 ... 3
• 1. 연구배경 및 필요성 ... 3
• 2. 연구 목표 ... 3
• II. 연구방법 및 수행전략 ... 4
• 1. 1~2차년도(2003~2004년) ... 4
• 2. 3차년도(2005년) ... 4
• III. 연구결과 ... 4
• 1. 1~2차년도(2003~2004) ... 4
• 2. 3차년도 (2005년) ... 9
• IV. 결론 및 고찰 ... 13
• V. 참고문헌 ... 14
• VI. 연구결과 활용 ... 16
• 1. 학회발표 2건 ... 16
• VII. 영문초록 ... 16