Jones L F, Zakanycz J P, Thomas E T, Farmer J J
Appl Microbiol. 1974 Feb;27(2):400-6. doi: 10.1128/am.27.2.400-406.1974.
A simplified method has been devised for typing Pseudomonas aeruginosa by pyocin production. Pyocins are produced as strains grow overnight in Trypticase soy broth (without glucose) plus 1% potassium nitrate. Because P. aeruginosa can use nitrate instead of oxygen as a terminal electron acceptor, mechanical shaking is not necessary, nor is induction by mitomycin C. Pyocins can now be produced in screw-cap tubes in a water bath or incubator. A total of 250 strains were tested as possible pyocin indicators, which included 60 strains already used in pyocin-typing systems. The final set contained 18 indicators which were chosen because (i) they had clear positive or clear negative reactions, thus eliminating reactions difficult to read, (ii) they had few zones due to bacteriophage lysis, and (iii) they were most sensitive in differentiating clinical isolates of P. aeruginosa. The final typing method was tested in several studies and the results were clear; thus definitive epidemiological conclusions could be made. Because it is simple to perform and easily automated, the new method should have application in many hospitals; however, it should be used only in carefully planned epidemiological studies. The method and its application are described in detail, and some pitfalls are discussed.
已设计出一种通过绿脓菌素产生对铜绿假单胞菌进行分型的简化方法。绿脓菌素是菌株在胰蛋白酶大豆肉汤（不含葡萄糖）加1%硝酸钾中过夜培养时产生的。由于铜绿假单胞菌可以利用硝酸盐代替氧气作为末端电子受体，因此无需机械振荡，也无需丝裂霉素C诱导。现在可以在带螺旋盖的试管中于水浴或培养箱中产生绿脓菌素。总共测试了250株菌株作为可能的绿脓菌素指示菌，其中包括60株已用于绿脓菌素分型系统的菌株。最终选定了18株指示菌，选择的原因是：（i）它们有明确的阳性或阴性反应，从而消除了难以判读的反应；（ii）它们因噬菌体裂解产生的噬菌斑较少；（iii）它们在区分铜绿假单胞菌临床分离株方面最为敏感。在多项研究中对最终的分型方法进行了测试，结果明确；因此可以得出明确的流行病学结论。由于该方法操作简单且易于自动化，应可在许多医院应用；然而，它仅应在精心规划的流行病学研究中使用。详细描述了该方法及其应用，并讨论了一些潜在问题。
