MICROM 442 Study Guide - Midterm Guide: Nontuberculous Mycobacteria, Mycobacterium Tuberculosis Complex, Kinyoun Stain
Document Summary
Neither gram negative nor positive, but staining is often weakly positive. Results from the unique cell wall structure, with 60% mycolic acids (waxy coats) and lipoarabinomannan. Renders mycobacterial cells very resistant to drying (likely aids transmission in droplets: acid fast staining (ziehl-neelsen of kinyoun stain): stain with carbon fuchsin, decolorize with acid-alcohol, counterstain with methylene blue, slow growing and difficult to culture (fastidious) M. abscessus, chelonae, forms visible colonies or growth in less than or equal to. May be used to speciate clinical isolates (can also use pcr and biochemical tests: aerobic, aerobic, generally non-motile (exception: m. marinum can move intracellularly, clinically, host genetics thought to play important role in susceptibility/manifestations. Forensic evidence: fossil bone evidence that it infected homo erectus (>500k years ago- nyt, 2007, dna evidence found in neolithic humans (>4k years ago) identi ed in the spines of mummi ed egyptian remains. Tb disease burden is highest in areas with endemic hiv.
