Study on the ecological characteristics of environmental bacteria, and selection of a simple and easy genotyping method for the tracking their sources and disseminating routes in the hospitals.

首先，我们调查了生物膜形成，环境细菌的生态特性，对消毒剂的敏感性使用铜绿假单胞菌（Ps）之间的关系。主要结果如下：1.从29处场所中分离到21处Ps，其中包括护士站的水塞和排水区，以及小便冲洗和洗浴区。2.聚四氟乙烯片试验，其中生物膜形成固着细胞（SC）和漂浮细胞（FC）的区别，结果表明，除1株环境分离株外，21株环境分离株和10株临床分离株均被生物膜覆盖（苄索氯铵和葡萄糖酸氯己定）敏感试验显示SC的存活率显著高于FC。4. SC的存活率在临床分离株中表现得更为明显，其次，比较了随机扩增多态性DNA聚合酶链反应（RAPD）、PCR和PCR三种基因分型方法的优缺点使用三种不同引物的RAPD-PCR（pr 1 ~ 3）、脉冲场凝胶电泳法（PFGE）和罕见限制性酶切位点PCR法（IRS-PCR），目的：用16株粘质沙雷氏菌（Sm）为感染控制护士（ICN）选择一种简便易行的方法。结果表明：1.16个菌株在RAPD-PCR（pr 1）、RAPD-PCR（pr 2）和PFGE、IRS-PCR和RAPD-PCR（pr 3）中分别被分为15型、13型、9型和7型。RAPD-PCR在时间（2 d）、简便性等方面优于PFGE。3. RAPD-PCR可作为ICN医院感染源及传播途径的检测方法。

Initially, we investigated the relation between biofilm formation, an ecological characteristic of environmental bacteria, and sensitivity against disinfectants using Pseudomonas aeruginosa(Ps). The main findings are summarized as follows.1.Ps could be isolated from as much as 21 places from 29 places including water-plug and drainage areas in the nurse station, and urinal-washing and bath areas.2.Teflon-sheet test, in which biofilm-forming sessile cells (SC) is distinguished from floating cells(FC), showed that biofilm was detected in all strains including 21 environmental isolates and 10 clinical isolates except one environmental isolates.3.Disinfectant(benzethonium chloride and chlorhexidine digluconate)-sensitivity test showed that survival rates of SC are significantly higher than those of FC.4.The higher survival rates of SC is shown more clearly in the clinical isolates, suggesting that recontamination of health-care environments with the clinical isolates should be avoided.Secondly, we compared three genotyping methods, random amplified polymorphic DNA polymerase chain reaction method(RAPD-PCR) using three different primers(pr 1 to 3), pursed field gel electrophoresis method(PFGE) and infrequent restriction site PCR method(IRS-PCR), to select a simple and easy one for the infection control nurses(ICN) using 16 stains of Serracia marcescens (Sm). The main findings are summarized as follows.1.16 strains were distinguished to 15 types, 13 types, 9 types and 7 types in the RAPD-PCR (pr 1), RAPD-PCR(pr 2) and PFGE, IRS-PCR, and RAPD-PCR(pr 3), respectively.2.These data indicate that strain-distinguishing efficiency of RAPD-PCR is almost comparable to that of PFGE if an appropriated primer is constructed. However, RAPD-PCR has more merits than PFGE from the aspects of time consumption (2 days versus 7 days) and simplicity.3.In summary, RAPD-PCR should be recommended for ICN to search the sources and disseminating routes of hospital-acquired infection.