Eikenella corrodens is a gram-negative facultative bacillus commonly found in the oral cavity. Although the role of E. corrodens in periodontitis is not clear, its isolation from extraoral infections attests to its pathogenic potential. Previous studies suggested that this species is phenotypically diverse. In the present study, we used restriction endonuclease analysis (REA) to assess the genetic diversity of this species and to explore the applicability of REA in studying the transmission of E. corrodens. Two groups of E. corrodens isolates were used in this study. Group 1 included 47 epidemiologically independent isolates recovered from dental plaques in periodontally healthy subjects and periodontitis patients and from extraoral infections in different geographic areas. Group 2 E. corrodens included 40 isolates recovered from two periodontitis patients and two periodontally healthy subjects. The results indicated that E. corrodens is genetically heterogeneous, as determined by REA. The majority of the group 1 E. corrodens isolates exhibited strain-specific restriction patterns. Forty restriction patterns were distinguishable among the 47 isolates. Analyses of group 2 isolates revealed that three of four subjects harbored more than one clonal type of E. corrodens. In one instance, a periodontitis patient was found to be colonized by six different clones. Furthermore, two different clonal types of E. corrodens were recovered from a single periodontal pocket in this patient. The results indicated that REA may be a useful tool in the epidemiologic investigation of E. corrodens infections.
Fourteen human periodontal isolates recovered from a purported Eikenella corrodens-selective medium containing 1 pg of clindamycin per ml displayed biochemical traits which differed from those described for E. corrodens. These organisms were gram-negative rods which corroded agar. The isolates were oxidase positive and urease, indole, and esculin negative. They differed from E. corrodens in catalase, nitrate reduction, lysine decarboxylase, and ornithine decarboxylase activities. One isolate, strain UB-294, was presumptively identified as Kingella denitnjkans. A second isolate, strain UB-204, differed from E. corrodens by being catalase positive and nitrate reduction negative. Twelve isolates, including strain UB-3ST (T = type strain), were phenotypically similar to Kingella kingae except that they did not produce acid from maltose and were not beta-hemolytic. Essentially complete (1,480-base) 16s rRNA sequences were determined for strains UB-3ST, UB-204, and UB-294 and the type strains of Neisseria animalis, Neisseria canis, Neisseria denitr@cans, Neisseria elongata, Neisseria JEavescens, Neisseria macaca, and Neisseriu polysaccharea. These sequences were compared with the previously published sequences of six other species belonging to the family Neisseriaceae. On the basis of the results of the comparative sequence analysis, UB-294 was confirmed as a K. denitrificans strain, UB-204 was identified as a member of a new species which may belong in the genus Eikenella, and UB-38T was identified as a member of a new species of the genus Kingelk, for which we propose the name Kingella orale. Since strain UB-204 was the only representative of a new species, it was not named. DNA probes for identification of E. corrodens, K. denitrificans, and K. orale based on 16s rRNA sequence information are described.In a previous study examining the prevalence of Eikenella corrodens in the human oral cavity, we frequently encountered gram-negative bacteria phenotypically similar to, but distinguishable from, Eikenella corrodens (2). These nonEikenella corrodens isolates grew well on selective medium containing 1 kg of clindamycin per ml, corroded agar, and did not produce acid from sugars as determined by standard broth tests. In contrast to Eikenella corrodens, these isolates lacked one or more of the following biochemical traits: nitrate reduction activity, lysine decarboxylase activity, and ornithine decarboxylase activity. In a subsequent study of six of these isolates, we reported that they exhibited less than 33% DNA homology with Eikenella cowodens reference strains (3). Four of these strains exhibited more than 70% DNA homology with one another, indicating that they belonged to a single species. In this study, we further characterized these six isolates, as well as eight additional strains. We found that the 14 isolates fell into three groups on the basis of biochemical characteristics and protein profiles determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE). 16s rRNA sequences were determ...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.