Identification of clinically significant Mycobacterium fortuitum complex isolates

Abstract

Recent outbreaks of nosocomial infections caused by organisms identified as the Mycobacterium fortuitum complex suggest that species and subspecies identification is epidemiologically important. In a study of 170 strains, M. fortuitum was differentiated from M. chelonei by nitrate reduction and iron uptake. M. fortuitum was further divided into biovariant fortuitum, biovar peregrinum, and an unnamed third biovar by inositol and mannitol utilization. M. chelonei was further divided into subsp. chelonei, subsp. abscessus, and an unnamed subspecies by tolerance to 5% sodium chloride, utilization of mannitol and sodium citrate, and uptake of iron.