Usui Masaru, Kawakura Mayuko, Yoshizawa Nobuki, San Lai Lai, Nakajima Chie, Suzuki Yasuhiko, Tamura Yutaka
Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan.
Division of Bioresources, Hokkaido University Research Center for Zoonosis Control, Sapporo, Hokkaido, Japan.
Anaerobe. 2017 Feb;43:15-20. doi: 10.1016/j.anaerobe.2016.11.004. Epub 2016 Nov 18.
Pigs, particularly piglets, have been identified as reservoir hosts of Clostridium difficile. To examine the survival ability of this pathogen in pig feces-based manure compost, C. difficile spores, which were prepared to contain as few vegetative cells as possible, were artificially inoculated into pig feces and incubated at different temperatures. While C. difficile survived in the feces incubated at temperatures below 37 °C for over 30 days, cell numbers gradually decreased at thermophilic temperatures (over 55 °C; p < 0.05). Next, to clarify the prevalence of C. difficile in field manure compost, we isolated and characterized C. difficile from the final products of manure compost products of 14 pig farms. A total of 11 C. difficile strains were isolated from 5 of 14 (36% positive rate) samples tested. Of these 11 strains, 82% were toxigenic, with ribotype 078 being the most prevalent. Thus, the application of composted manure to land therefore poses a possible risk of C. difficile transfer to the food chain.
猪，尤其是仔猪，已被确定为艰难梭菌的储存宿主。为了研究这种病原体在猪粪堆肥中的存活能力，将尽可能少含营养细胞的艰难梭菌孢子人工接种到猪粪中，并在不同温度下孵育。虽然艰难梭菌在低于37°C的粪便中存活超过30天，但在嗜热温度（超过55°C；p<0.05）下细胞数量逐渐减少。接下来，为了阐明艰难梭菌在田间粪肥堆肥中的流行情况，我们从14个养猪场的粪肥堆肥产品的最终产物中分离并鉴定了艰难梭菌。在测试的14个样本中的5个（阳性率36%）中总共分离出了11株艰难梭菌菌株。在这11株菌株中，82%具有产毒性，其中核糖体分型078最为常见。因此将堆肥施用于土地可能会带来艰难梭菌转移到食物链中的风险。
