Introduction:

In Mexico, there is an alarming increase in the number of cases of Mycobacterium bovis infection on pulmonary and extrapulmonary presentations. The lack of timely identification triggers complications and increases mortality.

Objective:

To know the frequency of M. bovis infections in clinical samples of patients with tuberculosis in the mycobacteria laboratory of a reference hospital in Mexico City.

Method:

Prospective, descriptive study. Strains isolated from biological material were studied in Löwestein-Jensen and MGITI960 cultures. M. bovis was identified by amplifying the RD9 fragment with end-point polymerase chain reaction (PCR).

Results:

Eight-hundred and fifty tuberculosis-diagnosed patients were included; in 441 cases, Mycobacterium tuberculosis was confirmed by positive culture (250 pulmonary, 65 ganglionic, 39 renal, 34 meningeal, 25 miliary, 14 pleural, 8 peritoneal, 4 bone and 2 pericardial cases). Forty-eight strains (10.8%) were typified as M. bovis by amplification of the RD9 fragment with end-point PCR.

Conclusions:

M. bovis is not currently thought of a causative agent of tuberculosis, which could be the cause of pharmacological treatment failure. In this study, the main extrapulmonary form was observed to be cervical lymphadenopathy.