The occurrence of Clostridium difficile in nine wastewater treatment plants in the Ticino Canton (southern Switzerland) was investigated. The samples were collected from raw sewage influents and from treated effluents. Forty-seven out of 55 characterized C. difficile strains belonged to 13 different reference PCR ribotypes (009, 010, 014, 015, 039, 052, 053, 066, 070, 078, 101, 106, and 117), whereas 8 strains did not match any of those available in our libraries. The most frequently isolated ribotype (40%) was 078, isolated from six wastewater treatment plants, whereas ribotype 066, a toxigenic emerging ribotype isolated from patients admitted to hospitals in Europe and Switzerland, was isolated from the outgoing effluent of one plant. The majority of the isolates (85%) were toxigenic. Forty-nine percent of them produced toxin A, toxin B, and the binary toxin (toxigenic profile A+ B+ CDT+), whereas 51% showed the profile A+ B+ CDT−. Interestingly, eight ribotypes (010, 014, 015, 039, 066, 078, 101, and 106) were among the riboprofiles isolated from symptomatic patients admitted to the hospitals of the Ticino Canton in 2010. Despite the limitation of sampling, this study highlights that toxigenic ribotypes of C. difficile involved in human infections may occur in both incoming and outgoing biological wastewater treatment plants. Such a finding raises concern about the possible contamination of water bodies that receive wastewater treatment plant effluents and about the safe reuse of treated wastewater.
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机译：调查了提契诺州（瑞士南部）的9个废水处理厂中艰难梭菌的发生情况。样品是从原污水和处理过的污水中收集的。 55个特征化艰难梭菌菌株中有47个属于13种不同的参考PCR核型（009、010、014、015、039、052、053、066、070、078、101、106和117），而8个菌株与我们的库中的任何不匹配。从六个污水处理厂中分离出的最常见的核糖型（40％）是078，而从欧洲和瑞士的住院病人中分离出的一种有毒的新兴核糖型066是从一家工厂的流出物中分离出来的。大多数分离株（85％）是产毒的。其中百分之四十九产生毒素A，毒素B和二元毒素（产毒曲线A + B + CDT +），而51％的人表现出曲线A + B + CDT-。有趣的是，2010年从提契诺州医院收治的有症状患者中分离出了8种核糖型（010、014、015、039、066、078、101和106）。尽管取样有限，但这项研究突出了认为，与人类感染有关的艰难梭菌的产毒核糖型可能会在进出的生物废水处理厂中发生。这一发现引起了人们对接收废水处理厂废水的水体的可能污染以及对经过处理的废水的安全再利用的关注。
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