Distribution of virulence genes and antimicrobial susceptibility of Salmonella isolated from dogs and chickens in Zambia

William Ulaya, Bernard Hangombe, Victor Zulu, King Nalubamba, Evans Mulenga, Hiroshi Isogai, Emiko Isogai

School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka, Zambia. 2Animal Research Center, Sapporo Medical University, South 1 West 17, Chuoh-ku, Sapporo, 060-8556, Japan. 3Laboratory of Animal Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori Amamiya-Machi Aoba-ku, Sendai 981-8555, Japan.

???Corresponding author’s E-mail: mudenda68@yahoo.com

Accept Date: Sep 10, 2012 23:31

Abstract :

The present study was conducted to investigate the distribution of virulence genes and the antimicrobial susceptibility of Salmonella isolated from dogs and chickens. A total of 379 samples were examined with 41 Salmonella isolates being cultured with 18 (7.4%; 95% CI: 4.57- 11.6) and 23 (16.9%; 95% CI: 11.2-24.5) isolates from dog and chicken, respectively. On serotyping, the isolates belonged to Group B, C, D and E, while 6 isolates from dog were untypeable. The Polymerase chain reaction (PCR) assay was carried out to detect Salmonella invA, invF and sipC virulence genes. A varying distribution of the targeted virulence genes was observed amongst the isolates. InvA was found in all the 41 strains, invF was found among 3 dog and 10 chicken isolates with sipC being observed among 2 dog and chicken isolates respectively. On antimicrobial susceptibility, dog isolates were susceptible to amoxicillin (100%) and nitrofurantoin (94.4%), whereas chicken isolates showed susceptibility to nitrofurantoin (100%), amoxicillin (95.7%), ampicillin and tetracycline (82.6%). It was concluded that dogs and chickens are important carriers of invasive Salmonella in Zambia with a multiple antimicrobial drug resistance pattern. This may be a potential source of human salmonellosis which is difficult to manage by antibiotic therapy. Key words: Salmonella, virulence-genes, chicken, dog.