This study was performed considering the public health hazards related to the elimination of mycobacteria through milk of dairy cows suspected or positive for tuberculosis presenting no clinical alterations. A total of 780 milk samples from 52 animals, positive or suspected for tuberculosis, according to Stormont's test, were analysed to detect Mycobacterium spp. The samples consisted of 300 ml/cow, collected in the first milking of the day, during 15 days. Frozen samples were sent to the laboratory, inoculated in Löwenstein-Jensen with reduced glicerol (0.5%) and Stonebrink media and kept under 37ºC for at least 90 days. The genus of each observed colony was initially confirmed by Ziehl-Neelsen and auramin staining methods. The isolation of Mycobacterium spps was confirmed in 78 (10%) samples collected from 19 (36.54%) animals. According to thin layer chromatography, time and temperature growth characteristics and colonies aspects, the 19 animals eliminated: M. avium (5.26%), M. fortuitum (10.52%), M. bovis (5.26%) and Mycobacterium spp. (78.95%).
Tuberculosis; Cattle; Milk; Public health; Mycobacterium
