Molecular Detection of Mycobacterium bovis in Cattle Milk in Enugu State, Nigeria

Abstract

The study was carried out to detect Mycobacterium bovis in cattle milk in Enugu. Fifty Milk samples were collected from cattle at Fulani settlements which comprised of 13 from Gariki, 16 from 9th Mile and 21 from Monarch in Enugu. DNA was extracted from milk samples using Relia prep DNA spin column method and screened for Tuberculosis using Nested Polymerase Chain Reaction (PCR) with specific Tuberculosis primer; Insertion sequence 6110 (IS6110) while Restriction Fragment Length Polymorphism (IS6110- RFLP) method was used to differentiate between Mycobacterium bovis and Mycobacterium tuberculosis using Nar 1 digestion enzyme. Statistical tools used to analyze the data were: Chi-square, fishers’ exact test and non parametric t test. 9 (18%) samples out of the 50milk samples were positive for tuberculosis with the PCR method. 1 (2%) out of the 9 positive milk samples was found to be Mycobacterium tuberculosis while the remaining 8 (16%) were detected to be Mycobacterium bovis after using the digestion enzyme. 1 (6.3%) of the 16 milk samples collected from the Fulani settlement in 9^th Mile was positive for M.bovis while a total of 2 (15.4%) out of the 13 milk samples from Gariki were positive for M.bovis and a total positive of 6 (28.6%) were detected out of the 21 milk samples analyzed from Monarch, 5 (23.8%) of which were found to be M.bovis while M. tuberculosis was detected in 1 (4.8%). The differences however, were not statistically significant (P>0.05).

Keywords: Tuberculosis, Mycobacterium bovis, Mycobacterium tuberculosis, DNA