The impact of the coexistence of mycobacterium avium with mycobacterium tuberculosis on the result of GeneXpert and MGIT susceptibility test.

Rapid tests to diagnose tuberculosis relies on molecular detection of the M. tuberculosis. GeneXpert MTB/RIF test identifies M. tuberculosis and rifampicin resistance. We present a case of simultaneous coinfection with M. tuberculosis and M. avium. M. tuberculosis was detected in the sputum by PCR GeneXpert method. Unrecognized coexistence of M. tuberculosis and M. avium modified the results of drug susceptibility tests making the primary identification of M. tuberculosis as multi-drug resistant strain. We performed in vitro experiments to investigate the effect of the coexistence of M. avium with M. tuberculosis on the results of GeneXpert method, and drug susceptibility test.