Craven S E
Poultry Microbiological Safety Research Unit, R. B. Russell Agricultural Research Center, U.S. Department of Agriculture, Athens, Georgia 30613.
Avian Dis. 1994 Jul-Sep;38(3):401-8.
Salmonella typhimurium strain 3333/O was used to assess the role of bacterial lipopolysaccharide (LPS) in intestinal colonization of broiler chicks by salmonellae. LPS-defective TnPhoA mutants of this strain were isolated. The sensitivities of the mutants to smooth and rough phages and LPS banding patterns in sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated a defect in the polysaccharide side chain of the LPS molecule. Colonization was determined by orally administering 10(8) cells each of the wild-type and/or the mutant strains per chick and counting the colony-forming units (CFU) from the ceca 1 to 3 weeks after gavage. CFU of chicks given the LPS-deficient strains either were not detected or were significantly lower than the CFU from chicks given the wild-type strain. The incidence of the wild-type strain in spleens was higher than incidence of the mutant strains. In vitro binding studies with LPS-deficient mutants derived in this study and from S. typhimurium LT2 suggest that LPS side-chain components may shield the bacterial cell from entrapment in the chicken mucus. The LPS layer appears to enhance persistence of Salmonella in the avian intestinal tract.
鼠伤寒沙门氏菌菌株3333/O被用于评估细菌脂多糖（LPS）在沙门氏菌对肉鸡肠道定植中的作用。分离出了该菌株的LPS缺陷型TnPhoA突变体。这些突变体对光滑和粗糙噬菌体的敏感性以及在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳中的LPS条带模式表明LPS分子的多糖侧链存在缺陷。通过每只雏鸡口服10⁸个野生型和/或突变株细胞，并在灌胃后1至3周对盲肠中的菌落形成单位（CFU）进行计数来确定定植情况。给予LPS缺陷菌株的雏鸡的CFU要么未被检测到，要么显著低于给予野生型菌株的雏鸡的CFU。野生型菌株在脾脏中的发生率高于突变株。对本研究中获得的以及鼠伤寒沙门氏菌LT2的LPS缺陷突变体进行的体外结合研究表明，LPS侧链成分可能保护细菌细胞不被鸡黏液捕获。LPS层似乎增强了沙门氏菌在禽类肠道中的持久性。
