The Mechanism of Resistance to Free Residual Chlorine and Pathogenesity in Protomonas extorquens Isolated from Drinking Tank-Water

从饮用水水箱中分离出大量的扭脱原单胞菌，对扭脱原单胞菌的耐氯机理进行了初步研究。在日本东京和筑波科学城调查，用标准琼脂和LNP琼脂培养基在25 ℃下培养7天，分离出扭脱原单胞菌，全市自来水、饮用水箱水（78.9%）和直饮水（64.3%）中检出了氯，游泳池水中检出率为40%，游离余氯浓度较高，为0.6- 1.0mg。1.<-1>扭脱原单胞菌（Protomonasextorquens）是一种在自然环境池塘、湖泊、河流中很少发现的微生物，本文对扭脱原单胞菌（Protomonasextorquens）的氯敏感野生株和抗氯突变株进行了生物型、抗菌药物敏感性、细菌脂肪酸组成、形态、细胞表层结构和质粒的检测，电镜观察表明，抗氯突变株的外膜厚而坚固。这种增强的外膜被认为与该细菌对氯的抗性有关。对该菌进行了裸鼠急性致病性试验。腹腔注射（i. P.）在腹腔注射后3天，从腹腔内分离到许多生物细胞，扭脱原单胞菌似乎在免疫受损的宿主中起重要作用。

A fundamental study was conducted to elucidate the mechanism of resistance to chlorine exhibited by Protomonas extorquens, which was isolated from the drinking water tank at a high frequency.Distribution of Protomonas extorquens, chlorine resisitant gram-negative rod bacteria, was investigated in Tokyo and Tsukuba Science City.It was isolated by using standard agar and LNP agar medium culture for 7 days at 25 ﾟC.Protomonas extorquens was highly detected from tap water, drinking tank-water (78.9%)and direct-water(64.3%),all over the city.Furthermore,it was found in 40% of swimming pool water, in which free residual chlorine-concentration was high, 0.6-1.0 mg . 1^<-1>.However, it was found little in natural environmental pond,lake and river.The Chlorine-sensitive wild strain and chlorine-resistant mutant strain of Protomonas extorquens were examined for biotypes, antimicrobial susceptibility, bacterial fatty acid composition, morphology, structure of the superficial layer of the cell and for the presence of plasmids.Electron microscopic observations showed that the resisitant strain microbes have thick and solid outer-membranes. This strengthened outer membrane was considered to be related with the resistance of this bacterium to chlorine. Plasmids were not detected in any tested strain.Acute pathogenisity of this bacteria to nude mouse was examined. Noun of them was died but their weight decreased in the group injected(i.P.) bacterial cells.Many bio-cells were isolated from intraperitoneum after 3 days injection.Protomonas extorquens seems to have a significant role in immunocompromised hosts.