hsp65 PCR-restriction analysis (PRA) with capillary electrophoresis for species identification and differentiation of Mycobacterium kansasii and Mycobacterium chelonae–Mycobacterium abscessus group

SummaryObjectivesThe aim of the present study was to identify and differentiate Mycobacterium kansasii and Mycobacterium chelonae–Mycobacterium abscessus group strains isolated from clinical and environmental sources in different countries.MethodsPCR-restriction analysis of the hsp65 gene (PRA) with automated capillary electrophoresis was applied to the isolates previously identified by conventional biochemical testing and the molecular INNO-LiPA MYCOBACTERIA assay.ResultsPRA performed very well in comparison with the two other methods (96.4% concordance). Among 27 M. kansasii isolates, this method detected five genetic types, of which type 1 represented the most common clinical isolate, as it is worldwide. PRA differentiated 29 M. chelonae–M. abscessus group isolates into Mycobacterium immunogenum type 2 (n = 13), M. chelonae (n = 12), and M. abscessus types 1 (n = 1) and 2 (n = 1). M. immunogenum was the most frequent (69%) isolate from humans, but only one of 11 cases was clinically significant. M. chelonae was the most commonly (83%) recovered from water. PRA also identified two isolates with hsp65 alleles representing previously unreported patterns.ConclusionsPRA based on automated capillary electrophoresis is a rapid, simple, and reliable method for the identification and differentiation of both clinically relevant and environmental isolates of M. kansasii and M. chelonae–M. abscessus group.