Antimicrobial susceptibility of Salmonella serotypes isolated from human and animals in Sudan

The aim of the present study was to determine the prevalence of multidrug resistance among Salmonella enterica serotypes recovered from human and animals in Sudan. A total of 119 Salmonella isolates recovered from stools of humans, cattle, camels and poultry were subjected to in vitro susceptibility against 10 commonly prescribed antibacterial agents. The test was done by the disc diffusion assay, isolates were categorized as sensitive or resistant based on standardized zones of inhibition and the odd ratio (OR) was performed to measures of degree of association between the two result characteristics of agents. The majority of Salmonella serotypes (80.67%) were found resistant to at least one of the tested nine antibacterial agents and 45 isolates (37.82%) were found multidrug resistant (MDR). Human isolates were found to be more resistant than the animal's isolates. Ciprofloxacin, gentamicin and colistin were found to be highly active against the isolates. But the isolates showed high resistance to ampicillin, chloramphenicol, tetracycline, furazolidone and sulfamethoxazole + trimethoprim. The odd ratios (OR) among the isolates to combination of two antimicrobials ranged from 1.1 to 5.75. The highest OR was shown in combination cefalexin-nalidixic acid, which has an OR of 5.75. Salmonella serotypes revealed very high resistance (80.67%) and high MDR (37.82%) rates. Salmonella sp. recovered from human exhibited higher rates of resistance than those recovered from animals.