Bacilloscopy, Bacterial culture, and Spoligotyping of Mycobacterium bovis strains isolated from cattle in North Central Algeria

This study aimed to assess bovine tuberculosis-like cases in three slaughterhouses in North Central Algeria and to confirm these suspected cases using microscopic, bacteriological examination, and molecular biology technique. We highlighted the factors influencing the prevalence of the disease. Also, the genomic profiles of Mycobacterium tuberculosis complex (MTBC) strains isolated by Oligonucleotide typing technique (Spoligotyping) were determined. At the abattoir level, bovine carcasses were routinely inspected to detect visible abnormalities including suspicious lesions of bovine tuberculosis (BTB). At the laboratory level (Pasteur Institute, Algiers), Ziehl-Neelsen staining, bacterial culture, biochemical study (nitrate reduction test), and spoligotyping were performed to confirm suspected cases. On a total of 1300 bovine carcasses, 100 presented BTB-like cases (7.69%). Animals over 5 years of age were more affected compared to other age groups. Lesions were observed more often in females than in males and cattle of local breed were the most exposed to BTB-like cases (P<0.05). Bacilloscopy data were positive for 44 of the 100 suspected samples (44%) while bacteriology showed that 56 cultures were positive, while 35 were negative and 9 were contaminated. Molecular spoligotyping of 40 Mycobacterium strains samples showed 19 spoligotype profiles of M. bovis, of which 50% of profiles have been previously detected in the Mediterranean area and the three spoligotype patterns not previously reported were named SB2651, SB2652, SB2653 (by http:// www.Mbovis.org). Measures and means to prevent TB transmission among animals and to humans should be recommended, and more intensive investigations are required using both routine and molecular diagnostic techniques to understand and further explore MTBC.