| Characteristics | Results for | ||
| Our isolate | M. avium complex | M. xenopi | |
| Niacin | − | − | − |
| Nitrate reduction | − | − | − |
| Heat stable catalase | + | + | + |
| Growth at 25˚C | + | + | − |
| Growth at 37˚C | + | + | + |
| Growth at 45˚C | + | − | + |
| Tween hydrolysis | − | − | − |
| Growth in presence of p-nitro benzoic acid (PNB) (500 mg/ml) and TCH (5 mg/ml) | + | + | + |
| Pigmentation (scotochromogen) | + | − | + |
| Iron uptake | − | − | − |
| Tolerance to Nacl (5%) | − | − | − |