Dennis Champagne, Director, Laboratory Services, at Microtest Laboratories, Inc., has written an article on microbial identification for Controlled Environments, which can be viewed on-line.
The article is interesting in that it looks at modern and rapid methods for microbial identification, including genotypic methods. As the article indicates:
“The new microbial identification systems, such as the MicroSEQ® instrument from Applied Biosystems, employ ribosomal DNA (rDNA) sequencing to replace phenotypic microbial ID methods, fatty acid ID methods, traditional plate identification, ELISA, or antibody-based methods. Using a phylogenetic approach, the systems sequence the stable 16S ribosomal RNA (rRNA) gene present in all bacteria. For fungi, they sequence the D2 region of the large fungi sub-unit. (Note that a single isolated colony—alive or dead—is sufficient for identification purposes.) After sequencing the rRNA gene, the systems automatically compare the results to validated sequences in their customizable microbial libraries. They then deliver a list of the closest matches, ranked according to genetic distance from the sample.”
Posted by Tim Sandle