Johns Hopkins Guides provide diagnosis, management, and treatment guidance for infectious diseases, diabetes, and psychiatric conditions. Explore these free sample topics:
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- Slow-growing acid fast bacilli (AFB), nontubercular mycobacterium (NTM).
- Runyon classification Group 2: scotochromogen (meaning develops yellow-orange pigment in either the light or the dark; other members include M. szulgai, M. gordonae).
- World-wide distribution; reservoir is soil, water.
- AFB smear appearance is thicker, longer than M. tuberculosis but definitive identification depends on culture.
- Differentiation from other NTM may be difficult.
- DNA probes or 16s ribosomal sequencing useful.
- Newly described M. parascrofulaceum may account for many clinical isolates. Difficult to distinguish in lab from M. scrofulaceum.
- Most closely related to M. simiae.
- Few human cases makes advice about treatment uncertain.