A strategy based on Amplified Fragment Length Polymorphism (AFLP) for routine genotyping of nontuberculous mycobacteria at the clinical laboratory

The increasing worldwide incidence of mycobacteriosis and the need to achieve improved clinical management makes nontuberculous mycobacteria (NTM) genotyping a useful tool. However, because of technical difficulties, medium size microbiology laboratories do not attempt to compare the genetic patterns that each of their isolates present. We have aimed to optimize a genotyping method with a reduced hands-on experimental time and that requires few technical resources. A strategy based on the Amplified Fragment Length Polymorphism (AFLP) methodology was developed using two rare-cutters enzymes (SacI and BglII). One out of seven primers was sequentially used in each amplification reaction that was analyzed by agarose gel electrophoresis. This approach makes it possible the timely genotyping of a moderate number of strains and its characterization without the need of image analysis software. We have genotyped 28 Mycobacterium intracellulare and 4 M. abscessus. Clinical researchers are encouraged to routinely genotype their NTM isolates.