Phenotypic and genotypic characterization of multidrug resistant Salmonella serovars isolated from slaughter animals and food products of animal origin in Ethiopia

Alemán. The widespread occurrence of multidrug resistance (MDR) in foodborne bacterial pathogens such as Salmonella is a global challenge. Multidrug resistance is linked with mobile DNA elements such as integrons which can disseminate genes encoding resistance to a number of antimicrobial drugs. Integrons are one of the mobile DNA elements which have specific structures and ability to capture genes notably those encoding antimicrobial resistance by a site specific recombination system and are found in both chromosomal and extra chromosomal DNA. We identified and characterized the antimicrobial resistance phenotypes, integrons and associated resistance gene cassettes involved in MDR Salmonella serovars isolated from slaughter animals and food products of animal origin in Ethiopia.Conclusions:Class 1 integrons carrying gene cassettes which confer resistance to different classes of antimicrobials, such as aminoglycosides, ß-lactams and trimethoprim are widespread among the MDR Salmonella serovars isolated from slaughter animals and food products of animal origin in Ethiopia.Thus, data presented confirm the important role of these genetic elements in the dissemination of multidrug resistance.Location on large transferable plasmids makes the horizontal intra- and interspecies transfer of dfrA1- aadA1- and dfrA12-orf-aadA2 -carrying integrons very efficient. aacCA5-aadA7 carrying integrons have become integrated into the chromosome in S . Kentucky, and this has led to a widely disseminated MDR clone in Ethiopian swine husbandry.The results presented also highlight the need for the prudent use of antimicrobials in the veterinary practices in Ethiopia.