Molecular Detection Of Mycobacterium Bovis In Cattle Milk And Abattoir Staff In Enugu

ABSTRACT

The study was carried out to detect Mycobacterium bovis in cattle milk and abattoir staff in Enugu. Blood samples were collected from 50 subjects at Artisan and Ogbete market abattoirs with 25 samples from each location. 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. Milk samples were cultured on Lowenstein Jensen medium and incubated for 8weeks at 37o C. DNA was extracted from both milk and blood 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. EnzymeLinked Immunosorbent Assay Technique was also used to analyze blood samples. Statistical tools used to analyze the data were: Chi-square, fishers exact test and non parametric t test. No growth was observed on Lowenstein Jensen media after 8weeks of incubation at 37o c, but 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 9th 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). With ELISA technique, tuberculosis IgM (TBIgM) were detected in 4 (8%) out of the 50 blood samples while 7 (14%) were positive in PCR method. After using Nar 1 digestion enzyme on the positive samples; 3 (6%) of the blood samples were positive for Mycobacterium tuberculosis while the remaining 4 (8%) were found to be Mycobacterium bovis. There was also no statistically significant difference between the positive samples (P>0.05).