Abstract: Objective To develop a rapid method with high sensitivity and specificity to detect Mycobacterium avium.Methods A polymerase chain reaction(PCR)was developed.Its sensitivity and specificity were verified by sequential dilution of DNA of M.avium and other 17 Mycobacterium spp.,respectively.Simulation of clinical infection was established by mixing normal skin tissue with M.avium.The treatment of the tissue specimens was optimized in order to improve the sensitivity of the PCR assay.Results A fragment of 427bp was amplified by the PCR assay with the strains of M.avium at the sensitivity of 1×10² cells/mL.The other 17 Mycobacterium spp.were all negative.The sensitivity of the PCR assay decreased to 1×10⁴cells/mL when M.avium was mixed with the homogenized skin tissue.The sensitivity recovered to 1×10² cell/mL when the skin tissue was diluted to≥1:4.Conclusion It is suggested that PCR be a rapid and reliable method for detection of M.avium.

Key words: Mycobacterium avium, Polymerase chain reaction