Genotype Diversity of Mycobacterium bovis and Pathology of Bovine Tuberculosis in Selected Emerging Dairy Regions of Ethiopia

Abstract

Bovine tuberculosis (bTB) is endemic in Ethiopia with higher prevalence in cattle, particularly in the central parts. Spread of Mycobacterium bovis (M. bovis) to wider regions is inevitable in uncontrolled conditions. This study was conducted to explore the pathology, characterize M. bovis strains, and describe genotypic diversity to demonstrate possible epidemiological links in emerging dairy areas of Ethiopia, namely, Mekelle and Gondar. Twenty-seven bTB positive cattle identified by the Single Intradermal Comparative Cervical Tuberculin (SICCT) test were subjected to post-mortem inspection to determine lesion distribution and pathological score. Samples from tissues with visible tuberculous or suspected non-visible lesions were processed and cultured following a standard protocol. Isolates identified as M. bovis by Region of Difference (RD)-based Polymerase Chain Reaction (PCR) were also spoligotyped to determine their spoligotype patterns. Post-mortem inspection of visceral organs indicated bTB suggestive lesions in 41% of the animals, with 25% being in the lungs. Lymph nodes from 77% of the animals had lesions. Fifty-five isolates identified from 24 of the slaughtered animals were confirmed as M. bovis. No other mycobacterial species were isolated. Spoligotyping classified strains from 21 of these animals into seven spoligotype patterns: SB0133,

Bacteriological and molecular characterization of Mycobacterium bovis isolates from tuberculous lesions collected among slaughtered cattle, Northwest Ethiopia

“…In our findings, culture-positive isolates were identified in 29% (18/62) of the tuberculous lesions, of which M. bovis was detected only in five isolates, all confirmed by MPT64 Ag assay and molecular tests, such as Hain Genotype LPA, RD4 typing, and spoligotyping. This agrees with the findings that explained M. bovis is isolated among slaughtered cattle in Ethiopia [ 10 , 27 , 28 , 45 ]. However, our study displays a lower prevalence of M. bovis than other reports elsewhere [ 46 – 50 ].…”

Isolation and Molecular Identification of Mycobacterium bovis from Slaughtered Cattle in Nekemte Municipality Abattoir, Ethiopia

“…RD4 deletion typing of the 9 isolates confirmed the presence of a PCR product of size 446 bp, indicating that they were “deleted for RD4” and hence identified as M. bovis [ 18 ]. Furthermore, molecular characterization using spoligotyping on the nine M. bovis isolates revealed that 55.6% (5/9) of the isolates belonged to three different spoligotype patterns, namely, SB0134, SB2233, and SB1176, which aligns with the findings of previously reported studies conducted by Mekonnen et al [ 45 ] and Berg et al [ 46 ]. The most dominant spoligotypes were SB2233 and SB0134 with a prevalence of 40% (2/5).…”

Evaluation of the discriminatory power of spoligotyping and 19-locus mycobacterial interspersed repetitive unit-variable number of tandem repeat analysis (MIRU-VNTR) of Mycobacterium bovis strains isolated from cattle in Algeria

“…The BCG cluster associated spoligotypes SB0120 and SB0121 are circulating nearly worldwide in Europe, Africa, and America [ 28 , 29 ]. Spoligotype SB0134 is also frequent in many African countries (e.g., Tunisia, Morocco, Mali and Ethiopia) [ 30 – 33 ]. The new type SB2520 identified in our study has been recently found in Ethiopia [ 33 ].…”

“…Spoligotype SB0134 is also frequent in many African countries (e.g., Tunisia, Morocco, Mali and Ethiopia) [ 30 – 33 ]. The new type SB2520 identified in our study has been recently found in Ethiopia [ 33 ]. The spoligotypes SB0339 and SB0119 are common on the Iberian peninsula, thereof SB0339 frequently reported for Spain and SB0119 in Portugal, and both were also reported for Morocco [ 24 , 34 , 35 ].…”