Drug of Choice in the Treatment of Multiple Drug Resistant (MDR) Salmonellae Isolated from Wildlife in Nigeria

Abstract

Multiple drug resistant (MDR) strains of Salmonella are frequently encountered with increased rates in recent years. Many variants of the organism have developed MDR genes which they retain even when antimicrobial drugs are no more in use, limiting the choice of drugs for therapy of Salmonella infections resulting in morbidity and mortality in both man and animals and raising more public health questions. The objective of this study was to evaluate the susceptibility of Salmonella spp. to twelve antimicrobial agents using the disk diffusion method. Eight Salmonella spp. isolated from wildlife were tested. All the isolates exhibited MDR, showing resistance to at least four and up to nine antimicrobial agents. They were all highly resistant (100%) to ceftazidime, cephazoline, cefuroxidine and ampicillin but were susceptible to nalidixic acid and ciprofloxacin. Six resistant patterns were observed, with ampicillin-cefuroxime sodiumcephazolin-ceftazidime and streptomycin-ampicillin-cefuroxime sodium-cephazolin-ceftazidime resistant patterns exhibited by two isolates each. The substantial multiple resistance pointed to the fact that limitations could be faced in choosing drugs for the treatment of Salmonella infections and that mortality and economic losses could be experienced especially if sensitivity tests are not carried out before antimicrobial choice is made for treatments in both man and animals.