Studies of development of method for detection of aquatic pathogenic bacteria in viable but non-culturable stage and their ecology.

一些细菌种类，如芽孢杆菌属和梭状芽孢杆菌属，通过形成孢子来适应不利的环境。近年来，人们认为，在自然环境中，除了孢子形成之外，还有一种耐受机制，即细菌细胞的存活但不可培养(VNC)阶段。一些水生细菌对人类是致病的，许多细菌可以在常规培养基上培养出来用于临床诊断，但也有一些不能检测到。我们试图建立一种检测VNC的方法，并将其应用于生态学研究，特别是对食物中毒细菌副溶血性弧菌的生态学研究。以弧菌侧鞭毛区基因为模板，建立了聚合酶链式反应方法，并对其有效性进行了检验。尽管有必要进行一些改进，但该方法被认为对检测VNC细胞很有用。对该弧菌进行了生态学研究，并提出了利用选择性培养基进行生态研究应注意的几个问题。

Some bacterial species such as genera Bacillus and Clostridium adapt against undesirable circumstances by spore formation. Recently it has been believed that a tolerant mechanism other than spore formation against change of environmental condition acts in natural environment, namely viable but non-culturable (VNC) stage of bacterial cells. Some of the aquatic bacteria are pathogenic for human and many of them can be detected by cultivation on/in usual media for clinical diagnostic, but some of them cannot. These undetectable bacteria are supposed to exist as VNC.We tried to develop method for detection of VNC and to apply it to ecological study, special emphasis on ecology of Vibrio parahaemolyticus, a food poisoning bacterium. A polymerase chain reaction method with primers induced from lateral flagellar gene of the vibrio was developed and its usefulness was tested. Although some improvements are necessary, the method is thought to be useful for detection VNC cells. Ecological study of the vibrio was also carried out and some points of problem in use of selective media to ecological study was suggested.