TABLE 1.

Phenotypic differences between patient isolates and type and reference strains of M. fortuitum complex^a

Characteristic	M. fortuitum ATCC 6841T	M. peregrinum ATCC 14467T	M. fortuitum third biovariant complex		Patient isolates (n = 4)
			d-sorbitol-positive strain ATCC 49403	d-sorbitol-negative strain ATCC 49935
Growth at 42°C	+	−	+	−	−
Hydrolysis of acetamide	+	−	+	+	−
Acid production from:
d-Mannitol	−	+	+	+	+
i-myo-Inositol	−	−	+	+	+
d-Sorbitol	−	−	+	−	−
Resistance tob:
Erythromycin (MIC, ≥8 μg/ml)	+	+	+	+	−
Minocycline (MIC, ≥16 μg/ml)	−	+	+	+	−
Doxycycline (MIC, ≥16 μg/ml)	−	+	+	+	−
Vancomycin (MIC, ≥32 μg/ml)	+	+	+	+	−
Kanamycin (zone size, <15 mm)	−	−	+	−	−
Tobramycin (zone size, <20 mm)	+	+	+	+	−
Neomycin (zone size, <20 mm)	−	−	+	−	−

^aSymbols: +, positive; −, negative. 

^bThe MIC breakpoints for resistance that were used are those of NCCLS (8). Disk contents were as follows: kanamycin, 30 μg; tobramycin, 10 μg; and neomycin, 30 μg. Zone sizes for resistance are those of Grange and Stanford (4).