Journal Article

Trends of Mycobacterium bovis Isolation and First-Line Anti-tuberculosis Drug Susceptibility Profile: A Fifteen-Year Laboratory-Based Surveillance

Cervera-Hernández, Miguel Enrique, Cinta-Severo, Carmen, Chávez-Mazari, Bárbara, Rodríguez-Cruz, Luis, Martínez-Gamboa, Areli, Cervantes-Sánchez, Axel, Ortiz-Conchi, Narciso, Torres-González, Pedro, Bobadilla-del Valle, Miriam, Ponce de León, Alfredo, Crabtree-Ramirez, Brenda, Gudiño-Enríquez, Tomasa, Sifuentes-Osornio, José

2015

Overview

Mycobacterium tuberculosis causes the majority of tuberculosis (TB) cases in humans; however, in developing countries, human TB caused by M. bovis may be frequent but undetected. Human TB caused by M. bovis is considered a zoonosis; transmission is mainly through consumption of unpasteurized dairy products, and it is less frequently attributed to animal-to-human or human-to-human contact. We describe the trends of M. bovis isolation from human samples and first-line drug susceptibility during a 15-year period in a referral laboratory located in a tertiary care hospital in Mexico City. Data on mycobacterial isolates from human clinical samples were retrieved from the laboratory's database for the 2000-2014 period. Susceptibility to first-line drugs: rifampin, isoniazid, streptomycin (STR) and ethambutol was determined. We identified 1,165 isolates, 73.7% were M. tuberculosis and 26.2%, M. bovis. Among pulmonary samples, 16.6% were M. bovis. The proportion of M. bovis isolates significantly increased from 7.8% in 2000 to 28.4% in 2014 (X(2)trend, p<0.001). Primary STR resistance was higher among M. bovis compared with M. tuberculosis isolates (10.9% vs.3.4%, p<0.001). Secondary multidrug resistance (MDR) rates were 38.5% and 34.4% for M. bovis and M. tuberculosis, respectively (p = 0.637). A rising trend of primary STR monoresistance was observed for both species (3.4% in 2000-2004 vs. 7.6% in 2010-2014; p = 0.02). There is a high prevalence and a rising trend of M. bovis isolates in our region. The proportion of pulmonary M. bovis isolates is higher than in previous reports. Additionally, we report high rates of primary anti-tuberculosis resistance and secondary MDR in both M. tuberculosis and M. bovis. This is one of the largest reports on drug susceptibility of M. bovis from human samples and shows a significant proportion of first-line anti-tuberculosis drug resistance.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Antitubercular agents / Antitubercular Agents - therapeutic use / Cattle / Disease susceptibility / Distribution / Health aspects / Humans / Laboratories / Laboratories, Hospital - trends / Mexico - epidemiology / Microbial Sensitivity Tests - trends / Milk / Mycobacterium bovis / Mycobacterium bovis - isolation & purification / Mycobacterium bovis - physiology / Population Surveillance / Prevalence / Tertiary Care Centers - trends / Trends / Tuberculosis / Tuberculosis - drug therapy / Tuberculosis - microbiology / Tuberculosis - physiopathology / Tuberculosis, Multidrug-Resistant - epidemiology