Prevalence of Salmonella Isolated in Cattle, Inva Gene Detection and Antimicrobial Susceptibility Patterns of Isolates

This study was conducted to investigate the occurrence of Salmonella species in cattle, and determine the serovar distribution in Jos, North Central Nigeria. Antimicrobial susceptibility patterns of isolates and the presence of invA gene were also determined. A total of 712 faecal samples were collected from 17 cattle farms, one control post and one abattoir and screened for Salmonella species according to techniques recommended by ISO 6579 (2002). Isolation rate of 3% was obtained. S. Pullorum, S. Hull, S. Poona and S. Rubislaw were isolated at the rates of 43.5%, 34.8%, 13.0% and 8.7% respectively. Higher isolation rates were recorded in adults (3.2%), females (4%), and White Fulani breeds (3.3%) and on farms (3.3%). Isolation rates of 6.3%, 3.1% and 1.6% were recorded in Jos-East, Jos-North and Jos-South respectively. To the best of our knowledge this is the first report of such Salmonella serotypes in cattle in the study area. This result is significant because S. Pullorum, recorded the highest occurrence. PCR detected the invA gene in 84.2% of isolates. Antimicrobial susceptibility tests showed a low prevalence of resistance probably due to low use of these agents amongst cattle owners in the area. However, 26.1% of isolates manifested resistance to sulphonamide while 4.3% were resistant to colistin as well as streptomycin. There was no record of multiple resistances. In conclusion, there is need to improve biosecurity on farms, discourage housing more than one animal species at a time and improve surveillance to prevent the emergence of new serovars in the area.

Keywords: Salmonella, Cattle, Serovar, White Fulani, invA gene.