Clinical and laboratory features of Mycobacterium mageritense

Abstract

Six clinical isolates of the nonpigmented, rapidly growing species Mycobacterium mageritense were recovered from sputum, bronchial wash, blood, sinus drainage, and two surgical wound infections from separate patients in Texas, New York, Louisiana, and Florida. The isolates matched the ATCC type strain by PCR restriction enzyme analysis of the 65-kDa hsp gene sequence of Telenti, high-performance liquid chromatography, biochemical reactions, and partial 16S rRNA gene sequencing. These are the first isolates of this species to be described in the United States and the first isolates to be associated with clinical disease. Susceptibility testing of all known isolates of the species revealed all isolates to be susceptible or intermediate to amikacin, cefoxitin, imipenem, and the fluoroquinolones and sulfonamides but resistant to clarithromycin. Because of their phenotypic and clinical similarity to isolates of the Mycobacterium fortuitum third biovariant complex (sorbitol positive), isolates of M. mageritense are likely to go undetected unless selected carbohydrate utilization or molecular identification methods are used.

FIG. 1.

FL-HPLC patterns of three strains of M. mageritense and two rapidly growing mycobacterial reference strains.

FIG. 2.

PRA restriction fragment length polymorphism pattern from isolates of M. mageritense and an M. fortuitum control. Lanes 1 to 4: BstEII digests from M. mageritense ATCC 700351^T, clinical isolates 1582 and 1852, and control isolate M. fortuitum ATCC 6841^T, respectively. Lanes 5 and 6: 100-bp and pGEm markers, respectively. Lanes 7 to 10: HaeIII digests with the same isolates as those used for the BstEII digests.