Rapid molecular methods enable the subtyping of unrelated strains but do so with different accuracy and reproducibility. They are available primarily to research and reference laboratories and include the following:17
- Pulsed Field Gel Electrophoresis (PFGE)
- Detects genetic variation between strains; useful for differentiating epidemiologically similar strains of Nocardia
- Multilocus Sequence Analysis (MLSA)
- Useful for Nocardia and Streptomyces species identification using analysis of specific preproteins (secA1), proteins (heat shock), and other cellular fatty acid components
- 16S rRNA gene sequencing has become the most popular as it allows for the identification of most aerobic actinomycetes to the genus and species level.18,19 Gene sequencing has been responsible for many recent changes in taxonomy (nomenclature). Species are renamed after discovering they belong to a new or different species (or genus). For more information, a procedure and list of suggested primers used for PCR and sequencing are provided in the Clinical Microbiology Procedures Handbook.19
