Identification of coryneform and other Gram‐positive rods with several methods

Abstract

The identification of 202 isolates of aerobically growing Gram‐positive rods from clinical material was attempted by using a combination of “traditional” morphological and biochemical tests (Hollis & Weaver (20)) plus patterns of cellular and metabolic fatty acids. This system served as the “gold standard” for three others, i.e. API Coryne (Rapid Coryne), MIDI TSBA and MIDI CLIN Aerobic. In addition, several growth, biochemical and susceptibility tests (growth on cystine‐tellurite blood agar, DNase, hippurate and starch hydrolysis, methanethiol formation, API ZYM, CAMP reaction, susceptibility to O/129 and to six antimicrobials) were done in order to check their usefulness for the identification of this group of bacteria. Our system, with the help of chemotaxonomic tests (m‐DAP and mycolic acids), was able to identify 154/202 (76%) of the isolates by species and an additional 41/202 (21%) by genus only; 7 (3%) could not be identified. The API Coryne system identified to species or genus level 140/195 isolates (72%). Corresponding figures for the MIDI TSBA and CLIN systems were 63/195 (32%) and 88/195 (45%); further details of species and genus identification are presented in the text. The main drawback of the commercial systems is the extent and probably the numerical depth of the data base. We recommend the use of our multisystem approach for the identification of Gram‐positive rods until commercial systems are based on a broader and numerically more extensive data base. The additional tests did not prove species‐ or genus‐specific.

Description of Human-Derived Centers for Disease Control Coryneform Group 2 Bacteria as Actinomyces bernardiae sp. nov.

“…Most of the strains were susceptible to gentamicin (MIC range, 2 to 64 p,g/ml) but resistant to ciprofloxacin (MIC range, 1 to 4 pg/ml). The antimicrobial agent susceptibility test results are, therefore, consistent with the data obtained for other Actinomyces species by Schaal (22) and von Graevenitz et al (27).…”

“…The taxonomic position of an individual strain, however, is often unclear (8,27). In 1987, workers at the Special Bacteriology Reference Laboratory at the Centers for Disease Control and Prevention (CDC) designated some coryneform bacteria that were referred to this laboratory CDC coryneform group 2 bacteria (19).…”

In vitro activity of linezolid and 12 other antimicrobials against coryneform bacteria

“…The following strains were included in the study: C. amycolatum (60 strains), C. striatum (30 strains), C. jeikeium (30 strains), C. urealyticum (10 strains), Brevibacterium casei (20 strains), Dermabacter hominis (20 strains) and Turicella otitidis (20 strains). All the strains were identified to the species level using published methods [2,10,11].…”

Corynebacterium timonense sp. nov. and Corynebacterium massiliense sp. nov., isolated from human blood and human articular hip fluid

“…Among this group, phenotypic identification at the species level on the basis of biochemical criteria remains problematic because of a lack of characteristic traits. The combination of chemotaxonomic markers (Collins et al, 1982;Von Graevenitz et al, 1994) and molecular approaches based on 16S rRNA and rpoB gene sequence analyses has improved the identification of members of the genus Corynebacterium (Khamis et al, 2004(Khamis et al, , 2005Pascual et al, 1995;Roux et al, 2004;Ruimy et al, 1995;Tang et al, 2000). At the time of writing, the genus comprised 70 recognized species, most of which have been described since 2000.…”