Genetic characteristics of an amikacin-resistant Brucella abortus strain first isolated from Marmota himalayana.

Brucella spp. are facultative intracellular pathogens that can persistently colonize animal host cells and cause zoonotic brucellosis. Brucellosis affects public health and safety and even affects economic development. Our lab found that a Brucella strain isolated from Marmota himalayana exhibited amikacin resistance. To annotate and analyze the potential resistance genes in this strain, we utilized sequencing platforms in this study and cloned potential resistance genes. The findings showed that the isolated strain belonged to B. abortus biovar 1 and was similar to B. abortus 2308. The isolate had amikacin resistance genes encoding aminoglycoside 3'-phosphotransferase. Based on the results of genome analysis, the isolated strain may have obtained amikacin resistance genes from Salmonella spp. through Tn3 family transposons. Notably, this study establishes a foundation for further research on the resistance mechanism of Brucella spp. and provides data that may be useful for the prevention and control of drug-resistant Brucella strains.