SPECIFIC AND FAST TYPING OF CLINICAL ISOL ATES OF MYCOBACTERIUM BY PCR AND RESTRICTION ENZYME ANALYSIS

BACKGROUND: Typing at specie level of Mycobacterium is usually perform ed by microbiological and biochemical methods that require a long time and/or sufficient amount of bacteria. Molecular biology can avoid the se problems using different techniques. METHODS: A colony growth of th e following mycobacteria has been analyzed: M. tuberculosis, M. kansas ii, M. avium, M. intracellulare, M. gordonae, M. phlei, M. aurum, M. f ortuitum, M. flavescens, M. marinum, M. xenopi, M. nonchromogenicum, M . terrae and M. chelonei. Strains were grown in Lowenstein Jensen medi um. DNA was obtained by proteolytic digestion and fenol extraction. Th e 16S rRNA gen was amplified by polymerase chain reaction (PCR) and th e amplification was digested by Haelll, Hpall, Rsal and Alul restricti on enzymes. Restriction fragment patterns were analyzed by agarose gel electrophoresis and UV transillumination. RESULTS: The combination of the patterns obtained with Hpall and Rsal was sufficient to generate 13 different combinated ones. The patterns of M. intracellulare and M. avium were the same. CONCLUSIONS: PCR and restriction enzyme analysis is an useful method for typing at species level of clinical isolates of mycobacteria.