Halebian S, Harris B, Finegold S M, Rolfe R D
J Clin Microbiol. 1981 Mar;13(3):444-8. doi: 10.1128/jcm.13.3.444-448.1981.
Several species of anaerobic bacteria display variable Gram stain reactions which often make identification difficult. A simple, rapid method utilizing a 3% solution of potassium hydroxide to distinguish between gram-positive and gram-negative bacterial was tested on 213 strains of anaerobic bacteria representing 19 genera. The Gram stain reaction and KOH test results were compared with the antibiotic disk susceptibilities (vancomycin and colistin) the preliminary grouping of anaerobic bacteria. All three procedures were in agreement for the majority of strains examined. Some strains of clostridia, eubacteria, and bifidobacteria stained gram negative or gram variable; the KOH and antibiotic disk susceptibility tests correctly classified these strains as gram-positive. The KOH test incorrectly grouped some strains of Bacteroides sp., Fusobacterium sp., Leptotrichia buccalis, and Veillonella parvula, but all Gram stain results for these strains were consistent for gram-negative bacteria. The KOH test is a useful supplement to the Gram stain and antibiotic disk susceptibility testing for the initial classification of anaerobic bacteria.
几种厌氧菌呈现出可变的革兰氏染色反应，这常常使鉴定变得困难。一种利用3%氢氧化钾溶液区分革兰氏阳性菌和革兰氏阴性菌的简单、快速方法，在代表19个属的213株厌氧菌上进行了测试。将革兰氏染色反应和氢氧化钾试验结果与厌氧菌初步分组的抗生素纸片敏感性试验（万古霉素和黏菌素）进行了比较。对于大多数检测菌株，所有这三种方法的结果是一致的。一些梭菌属、真细菌属和双歧杆菌属菌株革兰氏染色呈阴性或革兰氏可变；氢氧化钾试验和抗生素纸片敏感性试验将这些菌株正确分类为革兰氏阳性菌。氢氧化钾试验错误地将一些拟杆菌属、梭杆菌属、口腔纤毛菌和小韦荣球菌菌株进行了分组，但这些菌株的所有革兰氏染色结果对于革兰氏阴性菌来说是一致的。氢氧化钾试验是革兰氏染色和抗生素纸片敏感性试验的有用补充，可用于厌氧菌的初步分类。
