Roberts M C, Moncla B, Kenny G E
Department of Pathobiology, University of Washington, Seattle 98195.
J Gen Microbiol. 1987 Jun;133(6):1423-30. doi: 10.1099/00221287-133-6-1423.
We compared 22 Bacteroides species by DNA-DNA homology studies using the S1 endonuclease method. None of the currently defined species shared more than 30% DNA homology with any other species examined with the exception of B. buccae and B. capillus (which along with B. pentosaceus are now considered a single species), which shared 86% of their DNA sequences. Two clusters showed weak genetic relationships, with DNA homology greater than 10%. The first cluster included B. coporis, B. disiens, B. bivius, B. intermedius and B. melaninogenicus. The second cluster included B. fragilis, B. eggerthii, B. ovatus, B. thetaiotaomicron and B. uniformis. Five of the oral species, B. asaccharolyticus, B. gingivalis, B. loescheii, B. intermedius and B. melanogenicus, were chosen for study as whole chromosomal probes in dot blot assays. These were tested against 243 clinical strains biochemically identified as Bacteroides species. The DNA probes correctly identified 94% of the clinical strains. DNA probe and biochemical identification was 100% for two of the five species. In contrast, only 86% of the strains biochemically identified as B. intermedius were identified by the DNA probe. The DNA probes gave a species identification to seven strains which could not be biochemically identified.
我们使用S1核酸内切酶法，通过DNA-DNA同源性研究比较了22种拟杆菌。除颊拟杆菌和毛细拟杆菌（现在它们与戊糖拟杆菌被认为是单一物种）外，目前定义的任何物种与其他所检测物种的DNA同源性均不超过30%，颊拟杆菌和毛细拟杆菌共享86%的DNA序列。两个聚类显示出较弱的遗传关系，DNA同源性大于10%。第一个聚类包括体拟杆菌、双栖拟杆菌、二路拟杆菌、中间拟杆菌和产黑素拟杆菌。第二个聚类包括脆弱拟杆菌、埃氏拟杆菌、卵形拟杆菌、多形拟杆菌和单形拟杆菌。选择5种口腔物种，即不解糖拟杆菌、牙龈拟杆菌、洛氏拟杆菌、中间拟杆菌和产黑素拟杆菌，作为斑点印迹分析中的全染色体探针进行研究。用这些探针检测了243株经生化鉴定为拟杆菌属的临床菌株。DNA探针正确鉴定了94%的临床菌株。5种中的两种通过DNA探针和生化鉴定的结果为100%。相比之下，经生化鉴定为中间拟杆菌的菌株中，只有86%能被DNA探针鉴定。DNA探针还对7株无法通过生化方法鉴定的菌株进行了物种鉴定。
