Poultry Microbiological Safety and Processing Research Unit, U.S. Natl. Poultry Research Center, Agricultural Research Service, U.S. Dept. of Agriculture, 950 College Station Road, Athens, GA 30605-2720, U.S.A.
J Food Sci. 2018 Mar;83(3):770-779. doi: 10.1111/1750-3841.14056. Epub 2018 Feb 13.
Proteus mirabilis, a Gram-negative bacterium, is ubiquitous in the environment and is considered as the normal microflora in the human gastrointestinal tract. However, this bacterium is an opportunistic pathogen in humans, often causing urinary tract infections. Moreover, Proteus has been frequently isolated from food animals, including poultry. Whether this bacterium contributes to the foodborne illness in humans is unclear. In this report, P. mirabilis isolates recovered from broilers during housing in the units were characterized, their antimicrobial activity was assayed, and broiler immune response to the soluble proteins was determined. Cecal contents and fecal droppings were treated according to the standard protocol for isolation. Speciation based on biochemical reactions and the antimicrobial activity of the isolates were carried out using commercial kits. Immunoblot was assayed to determine immune status of broilers against P. mirabilis. A total of 10 isolates of P. mirabilis were selected for further characterization. These isolates could grow in pH 6.0 and 1% NaCl conditions. They were resistant to sodium lactate, troleandomycin, rifamycin SV, vancomycin, but sensitive to nalidixic acid, cefotaxime and novobiocin. Moreover, the CTX, ACC, CMY-1, BIC, NDM, VEB, qnrB and qnrD genes were detected by PCR amplification in all isolates. Sera from broilers harboring this bacterium reacted to the P. mirabilis soluble proteins, but not from litter- and age-matched P. mirabilis negative and SPF chickens, indicating that this bacterium infected chickens that could have humoral immune response against P. mirabilis. This study provides a rationale for further monitoring P. mirabilis during poultry production to determine whether this bacterium poses potential threats to public health.
奇异变形杆菌是一种革兰氏阴性细菌，广泛存在于环境中，被认为是人类胃肠道的正常微生物群。然而，这种细菌是人类中的机会性病原体，常引起尿路感染。此外，奇异变形杆菌已频繁从食用动物中分离出来，包括家禽。这种细菌是否会导致人类食源性疾病尚不清楚。在本报告中，对鸡舍中饲养的肉鸡中分离出的奇异变形杆菌进行了特征描述，测定了其抗菌活性，并测定了肉鸡对可溶性蛋白的免疫反应。根据标准分离方案处理盲肠内容物和粪便。根据生化反应和分离株的抗菌活性进行种属鉴定，使用商业试剂盒进行。免疫印迹用于检测肉鸡对奇异变形杆菌的免疫状态。选择了总共 10 株奇异变形杆菌进行进一步鉴定。这些分离株可在 pH 值为 6.0 和 1%NaCl 条件下生长。它们对乳酸钠、替考拉宁、利福霉素 SV、万古霉素有抗性，但对萘啶酸、头孢噻肟和新生霉素敏感。此外，所有分离株均通过 PCR 扩增检测到 CTX、ACC、CMY-1、BIC、NDM、VEB、qnrB 和 qnrD 基因。携带这种细菌的肉鸡血清与奇异变形杆菌可溶性蛋白发生反应，但与年龄和垫料匹配的奇异变形杆菌阴性和 SPF 鸡的血清没有反应，表明这种细菌感染了鸡，这些鸡可能对奇异变形杆菌产生了体液免疫反应。本研究为进一步监测家禽生产过程中的奇异变形杆菌提供了依据，以确定这种细菌是否对公共卫生构成潜在威胁。
