cobas^® MAI

Mycobacterium avium complex (MAC) detection

Nontuberculous mycobacteria (NTM) are mycobacterial species other than M. tuberculosis and M. leprae. NTMs are found ubiquitously in the environment, including soil and water. Although NTM can colonize body surfaces and secretions without causing disease, they have been associated with four distinct clinical syndromes; progressive pulmonary disease (MAC, M. kansasii, M. abscessus), superficial lymphadenitis, seen commonly in pediatric populations, (MAC, M. scrofulaceum, M. malmoense), disseminated disease in severely immunocompromised patients, and skin and soft tissue infection usually as a consequence of direct inoculation.^1,2 M. avium and M. intracellulare are two closely related, distinct species of nontuberculous mycobacteria (NTM), which comprise the M. avium complex (MAC), and may also be grouped together as M. avium-intracellulare (MAI). MAC is primarily a pulmonary pathogen that affects individuals who are immune compromised (e.g., patients with AIDS, cancer, receiving hematologic and solid organ transplants, or on immunosuppressive chemotherapy).⁴ NTMs, including MAC, should be identified to species level.^1,3 cobas^® MAI provides a solution to detect and differentiate M. avium and M. intracellulare DNA in human respiratory specimens providing important information for patient care decisions. This test is intended for use in conjunction with culture as an aid in the diagnosis of M. avium-intracellulare complex (MAC) infection.

cobas^® MAI is a duplex test designed to detect and differentiate M. avium and M. intracellulare DNA. Selective amplification of target nucleic acid from the sample is achieved by the use of target-specific forward and reverse primer for the M. avium complex which is selected from a highly-conserved region within the respective target organism. MAC is detected by one selective set of primers and M. avium and M. intracellulare are differentiated by two distinct probes within the amplification region.

Enabling a complete diagnosis is critical to ensure proper therapy is initiated. When patient presents with symptoms of tuberculosis, the cobas^® MTB test is performed. If positive, patient should be evaluated for drug resistance using cobas^® MTB-RIF/INH test. If negative, the cobas^® MAI test can be used to detect a nontuberculosis infection.