Phenotypic identification of Actinomyces and related species isolated from human sources

Abstract

Recent advancements in chemotaxonomic and molecular biology-based identification methods have clarified the taxonomy of the genus Actinomyces and have led to the recognition of several new Actinomyces and related species. Actinomyces-like gram-positive rods have increasingly been isolated from various clinical specimens. Thus, an easily accessible scheme for reliable differentiation at the species level is needed in clinical and oral microbiology laboratories, where bacterial identification is mainly based on conventional biochemical methods. In the present study we designed a two-step protocol that consists of a flowchart that describes rapid, cost-efficient tests for preliminary identification of Actinomyces and closely related species and an updated more comprehensive scheme that also uses fermentation reactions for accurate differentiation of Actinomyces and closely related species.

FIG. 1

Flowchart for preliminary identification of Actinomyces species. All enzyme reactions were performed with Rosco diagnostic tablets. ∗, see Table 2; ssp., subsp.; α-fuc, α-fucosidase.

FIG. 2

Flowchart for preliminary identification of Arcanobacterium species and A. schalii. All enzyme reactions were performed with Rosco diagnostic tablets.