Great Lakes WATER Institute, University of Wisconsin-Milwaukee, Milwaukee, WI 53204, USA.
J Appl Microbiol. 2010 Jun;108(6):1994-2002. doi: 10.1111/j.1365-2672.2009.04605.x. Epub 2009 Oct 26.
The purpose of the work was to evaluate the mCP method to correctly identify and enumerate Clostridium perfringens that are present in surface waters impacted by a mixture of faecal pollution sources.
Clostridium perfringens were enumerated and isolated from sewage influent, surface water and suspended sediments using the mCP method. Molecular characterization of isolates was performed using species-specific PCR, along with full-length sequencing of the 16S rRNA gene for a subset of isolates.
The environmental isolates were presumptively identified as C. perfringens based on utilization of sucrose, inability to ferment cellobiose and a positive action for acid phosphatase activity. All isolates (n = 126) were classified as C. perfringens based on positive results with species-specific PCR with a subset confirmed as C. perfringens based on the 16S rRNA gene identity.
The molecular results indicated all of the presumptive positive isolates were C. perfringens regardless of the source, e.g. sewage influent or environmental water samples. Sequencing revealed that C. perfringens obtained from sewage and the aquatic environment were nearly identical (c. 99.5% similarity).
From this study we conclude that the mCP method is a robust approach to enumerate and isolate C. perfringens from aquatic environments that receive diverse sources of faecal pollution.
本研究旨在评估 mCP 方法，以正确识别和计数受粪便污染混合源影响的地表水样本中的产气荚膜梭菌。
采用 mCP 方法从污水进水、地表水和悬浮沉积物中对产气荚膜梭菌进行计数和分离。采用种特异性 PCR 对分离株进行分子特征描述，并对部分分离株的 16S rRNA 基因进行全长测序。
根据蔗糖利用、不能发酵纤维二糖和酸性磷酸酶活性阳性，环境分离株被推测为产气荚膜梭菌。所有分离株（n=126）均基于种特异性 PCR 的阳性结果被分类为产气荚膜梭菌，部分分离株基于 16S rRNA 基因鉴定被确认为产气荚膜梭菌。
分子结果表明，所有推定阳性分离株均为产气荚膜梭菌，无论其来源是污水进水还是环境水样。测序结果表明，从污水和水生环境中获得的产气荚膜梭菌几乎完全相同（相似度约为 99.5%）。
本研究表明，mCP 方法是一种从受多种粪便污染源影响的水生环境中计数和分离产气荚膜梭菌的可靠方法。
