Molecular typing of Mycobacterium bovis isolates in Argentina: first description of a person-to-person transmission case

ETCHECHOURY, IGNACIO; ECHAVARRÍA VALENCIA, GABRIELA; MORCILLO, NORA; SEQUEIRA, M. D.; IMPERIALE, BELÉN; LÓPEZ, MARISA; CAIMI, KARINA; ZUMÁRRAGA, MARTÍN JOSÉ; CATALDI, ANGEL; ROMANO, MARÍA ISABEL

ZOONOSES AND PUBLIC HEALTH

WILEY-BLACKWELL PUBLISHING, INC

Año: 2010 vol. 57 p. 375 - 381

1863-1959

Bovine tuberculosis is caused by Mycobacterium bovis, a mycobacterium highlysimilar to M. tuberculosis that belongs to the M. tuberculosis complex. The mainhost of M. bovis is cattle but it also affects many other mammalians includinghumans. Tuberculosis in humans caused by either M. bovis or M. tuberculosisis clinically hard to distinguish. During 2004?2005, samples from 448 patientswith diagnosis of TB were collected from different regions of Argentina. ThePRA technique identified 400 isolates with representative patterns of mycobacterium.The predominant ones were the M. tuberculosis complex, the M. avium?M. intracellulare complex and M. gordonae. Samples with M. tuberculosiscomplex PRA restriction profiles were analyzed with a multiplex PCR to differentiatebetween M. tuberculosis and M. bovis. Multiplex PCR identified nineM. bovis. The results allowed the possibility to establish that 2% of pulmonarytuberculosis was due to M. bovis. Isolates of M. bovis from humans were examinedusing spoligotyping. These isolates presented five different spoligotypes.The main spoligotype was also the most frequently one found in cattle. Theremaining human spoligotypes (grouped in clusters) are occasionally found incattle. Variable number tandem repeat (VNTR) analysis identified five differentpatterns. By combining the results of spoligotyping and VNTR analysis, wewere able to differentiate seven M. bovis isolates. The remaining two M. bovissamples showed the same spoligotype and VNTR profile and belonged tohousehold contacts. An MDR-M. bovis was isolated from the samples of thesehousehold contacts. The identification of two epidemiologically linked casesof human M. bovis infection suggests person-to-person transmission of anMDR-M. bovis.