Changes of characterization of Salmonella Typhimurium isolate following sequential exposures to porcine neutrophil |
Hee-Soo Lee1, Aeran Kim1, Min Youn1, Ji-Youn Lee1, Suk-Kyung Lim1, Ho-Young Kang2, Han Sang Yoo3, Jung-Won Park1, Sung-Hwan Wee1, Suk-Chan Jung1 |
1Animal, Plant and Fisheries Quarantine and Inspection Agency 2Department of Microbiology, College of Natural Sciences, Pusan National University 3Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University |
Salmonella Typhimurium의 돼지 호중구내 연속노출에 따른 특성변화 |
이희수1, 김애란1, 윤민1, 이지연1, 임숙경1, 강호영2, 유한상3, 박중원1, 위성환1, 정석찬1 |
1농림수산검역검사본부 2부산대학교 자연과학대학 3서울대학교 수의과대학 |
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Abstract |
To develop a live vaccine candidate using an attenuated strain of Salmonella Typhimurium (ST), biochemical properties, plasmid profile, PFGE patterns and pathogenic analysis of the ST isolate were carried out after sequential passage of the ST isolate in porcine neutrophils. By the passage, the ability of the neutrophil-adapted isolate to utilize d-xylose was lost, while the ability of the strain to ferment trehalose was delayed after 2 or more days of the culture. Also, changes including deletion of the gene fragments were observed in PFGE analysis of the neutrophil-adapted isolates. Two plasmids, 105kb and 50kb, were cured in the strain passaged over 15 times in porcine neutrophils. The 50% of lethal dose ($LD_{50}$) of the parent strain was changed from $1{ imes}10^5;LD_{50}$ to $6{ imes}10^6;LD_{50}$ by the passage in intraperitoneal injection of the strains into mice. These results suggested that bacterial genotypic and phenotypic responses might be globally altered depending on the inside environment of neutrophils. |
Key Words:
live vaccine, neutrophil, plasmid curing, Salmonella Typhimurium |
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