MONOCLONAL INFECTION INVOLVING MYCOBACTERIUM-AVIUM PRESENTING WITH 3 DISTINCT COLONY MORPHOTYPES

Recent reports indicate that polyclonal infections may play an importa nt role in multiple drug resistance in Mycobacterium avium infections, We report here on the isolation of a single M. avium strain that appe ared to have smooth colony morphology upon initial isolation on a Lowe nstein-Jensen slant, Primary subculture onto Middlebrook 7H10, however , revealed three distinct morphotypes representing smooth opaque (SmO) , smooth transparent (SmT), and rough (Rg) colony morphologies. All th ree morphotypes were identified as M. avium by standard biochemical pr ocedures, Genprobe analysis, and mycolic acid patterns, Subsequent res triction fragment length polymorphism analysis, using SalI- and PvuII- digested genomic DNA, revealed identical patterns for hybridization wi th the IS1245 probe, Thin-layer chromatographic analysis of lipids fro m the three morphotypes revealed that only the SmT morphotype possesse d what appeared to be lipid components similar to, but unlike, previou sly described serovar-specific glycopeptidolipid antigens, Further ana lysis of internally radiolabeled deacylated lipids from the SmT morpho type, by high-performance liquid chromatography and thin-layer chromat ography, disclosed that some of these components can be internally rad iolabeled with [C-14] phenylalanine and [C-14]mannose. These results s uggest that these components are structurally similar to previously de scribed glycopeptidolipid antigens, This is apparently the first repor t of a monoclonal infection involving a single strain of M. avium pres enting with all three colony morphotypes, SmO, SmT, and Rg.