Chen C K, Potts T V, Wilson M E
Department of Oral Biology, State University of New York, Buffalo School of Dental Medicine.
J Periodontal Res. 1990 Mar;25(2):106-12. doi: 10.1111/j.1600-0765.1990.tb00900.x.
In a previous microbiological study of Eikenella corrodens, we noted the presence of E. corrodens strains with variability in colony morphology, as well as other corroding bacilli phenotypically similar to E. corrodens but which were unidentifiable on the basis of biochemical reactions. This raised questions as to whether E. corrodens constitutes a genetically heterogeneous group of organisms, and whether the unidentified corroding bacilli represent atypical E. corrodens or genetically unrelated organisms. In the present study, the genetic relationship among 14 E. corrodens isolates and 6 unidentified corroding bacilli was examined. DNA base compositions were determined from the melting temperatures of DNA samples. DNA homologies among E. corrodens and corroding bacilli were determined by DNA hybridization in solution using S1 nuclease. The % G + C content of E. corrodens strains varied from 56 to 58%, and from 56 to 60% for unidentified corroding bacilli. The DNA homologies among 12 E. corrodens isolates and 2 reference strains varied from 57 to 97%. Although these E. corrodens isolates exhibited variabilities in colony morphology and biochemical profile, no subspecies was identified. The unidentified corroding bacilli shared less than 33% homology with either of the E. corrodens reference strains. These corroding bacilli were further divided into 3 species on the basis of DNA hybridization studies using radiolabeled DNA from 2 representative corroding bacilli. One of the unidentified corroding bacilli appears to be a component of the normal flora in the human oral cavity. Our results indicate that E. corrodens is a genetically homogeneous species containing no recognizable subspecies.(ABSTRACT TRUNCATED AT 250 WORDS)
在先前对腐蚀艾肯菌的微生物学研究中，我们注意到存在菌落形态具有变异性的腐蚀艾肯菌菌株，以及其他在表型上与腐蚀艾肯菌相似但基于生化反应无法鉴定的腐蚀杆菌。这引发了关于腐蚀艾肯菌是否构成一组基因异质性生物体的问题，以及未鉴定的腐蚀杆菌是否代表非典型的腐蚀艾肯菌或基因上不相关的生物体。在本研究中，检测了14株腐蚀艾肯菌分离株与6株未鉴定的腐蚀杆菌之间的遗传关系。通过DNA样品的解链温度确定DNA碱基组成。使用S1核酸酶通过溶液中的DNA杂交确定腐蚀艾肯菌与腐蚀杆菌之间的DNA同源性。腐蚀艾肯菌菌株的G + C含量百分比在56%至58%之间，未鉴定的腐蚀杆菌为56%至60%。12株腐蚀艾肯菌分离株与2株参考菌株之间的DNA同源性在57%至97%之间。尽管这些腐蚀艾肯菌分离株在菌落形态和生化特征上表现出变异性，但未鉴定出亚种。未鉴定的腐蚀杆菌与任何一种腐蚀艾肯菌参考菌株的同源性均低于33%。基于使用来自2株代表性腐蚀杆菌的放射性标记DNA进行的DNA杂交研究，这些腐蚀杆菌进一步分为3个种。其中一种未鉴定的腐蚀杆菌似乎是人类口腔正常菌群的一个组成部分。我们的结果表明，腐蚀艾肯菌是一个基因同质的物种，不包含可识别的亚种。（摘要截短于250字）
