The next several pages will detail some of the medically important aerobic actinomycetes.
Note: Phenotypic characterization of the aerobic actinomycetes is time-consuming and difficult, which is why molecular testing is recommended in most cases.
The tables provided include some of the following main characteristics:
- Appearance on the Gram stain
- Appearance on the modified acid-fast stain [MAS]
- Genus (and species) of those most often associated with human disease
- Colonial growth characteristics
- Notable phenotypic characterizations
- Optimal temperature for growth
These tables are intended for use as an introduction to the genera - pointing out some of the noteworthy features and are not intended to be exhaustive. With the rise of genotypic characterization methods, the nomenclature of these bacteria is constantly evolving.
Note: Although images for some of the more infrequently encountered aerobic actinomycetes are scarce, a good source for the workbench is the Manual of Clinical Microbiology (published by ASM Press): Conville PS, Brown-Elliott BA, Witebsky FG. Nocardia, Rhodococcus, Gordonia, Actinomadura, Streptomyces, and other aerobic actinomycetes. In: Carroll KC, Pfaller MA, Landry ML, McAdam AJ, Patel R, Richter SS, Warnock DW, eds. Manual of Clinical Microbiology, 12th ed. ASM Press; 2019:525-557.
