Probabilistic identification of coryneform bacteria.

Abstract

A frequency matrix of positive results was constructed for major phena defined in a previous phenetic classification of several species of coryneform and related taxa. A total of 280 physiological characters from 441 strains were taken as basis for this identification matrix. Minimum number of diagnostic characters for the matrix was selected using computer programs for calculation of different separation indices (CHA-RSEP) and selection of group diagnostic properties (DIACHAR). The resulting matrix consisted of 31 phena versus 58 characters. Phena overlap within the matrix was found to be relatively small (OVERMAT program). For each phenon, the identification scores for the most typical hypothetical organism was satisfactory (MOSTTYP program).The matrix was evaluated theoretically and practically (MATIDEN program). The overall identification rate (442 strains) of the theoretical evaluation (Willcox probability >0.99) was 92.0%. In the practical evaluation (40 strains) a total of 33 strains (82.5%) were identified with a Willcox probability >0.9. For minor clusters and single strains belonging to genetically and chemotaxonomically defined species, additional identification tables are provided. When used in combination with chemotaxonomic methods, the identification matrix can improve the identification of coryneform bacteria.The use of numerical identification and the development of matrices for routine use has been successfully applied to various bacteria, e.g. Gram-negative non-fermentative bacteria (18, 31), vibrios (1,10), Gram-negative fermentative bacteria (17), bacilli (21, 36), micrococci (12), nocardioform bacteria (23), and streptomycetes (24, 30, 51). For some `coryneform ' bacteria, Hill et al. (16)

Clinical microbiology of coryneform bacteria

“…Kämpfer demonstrated the use of glycosidase tests by using fluorogenic substrates with high separation values at the genus level for coryneform bacteria (223). The same author has published on numerical classification of coryneform bacteria (225,226). However, this approach using hundreds of phenotypic tests for identification of a coryneform bacterium is not applicable in the routine clinical laboratory.…”

Diphtérie à Corynebacterium ulcerans

“…Ces conclusions sont confortées par des études portant sur l'analyse des ARNr 16S et confirment des résultats antérieurs obtenus par hybridations ADN-ADN ou par taxonomie numérique ou par chimiotaxonomie (composition des acides corynomycoliques et des acides gras) [2,6,16,17,23]. C. ulcerans pouvant être caractérisé par ses caractères phénotypiques, Riegel et al [24] ont proposé la nomenclature de C. ulcerans.…”