Spoligotype analysis of Mycobacterium bovis isolates from northern Mexico

Bovine tuberculosis is still rife in Latin America, producing huge economic losses. There are very few studies of the way this disease is spread through this geographical region, particularly in countries that border those that are almost free of Mycobacterium bovis. In this work, we have analyzed the spacer oligonucleotide typing (spoligotype) patterns of M. bovis isolates from cattle at Ciudad Juarez, a Mexican city close to El Paso, Texas. Fifty-eiaht M. bovis isolates collected from a herd in Northern Mexico were studied by spoligotyping. Nine spoligotype patterns were observed in total. Two were predominant (SB0121 and SB0140) and accounted for 50% and 14% of the isolates, respectively. Six patterns were found to be already described in an international M. bovis spoligotype database, while the other three (SB0985, SB0986, and SB0987) were novel. Interestingly, none of the isolates corresponded to any other Mexican pattern previously reported. This is the first spoligotype analysis of M. bovis strains from a border city between Mexico and the United States. The necessity for further studies to formulate a better identification of M. bovis strains within, and its dissemination between, the two countries is discussed.