Genetic and molecular features for hepadnavirus and plague infections in the Himalayan marmot

High genetic diversity of the himalayan marmot relative to plague outbreaks in the Qinghai-Tibet Plateau, China

Plague, as an ancient zoonotic disease caused by Yersinia pestis, has brought great disasters. The natural plague focus of Marmota himalayana in the Qinghai-Tibet Plateau is the largest, which has been constantly active and the leading source of human plague in China for decades. Understanding the population genetics of M. himalayana and relating that information to the biogeographic distribution of Yersinia pestis and plague outbreaks are greatly beneficial for the knowledge of plague spillover and arecrucial for pandemic prevention. In the present research, we assessed the population genetics of M. himalayana. We carried out a comparative study of plague outbreaks and the population genetics of M. himalayana on the Qinghai-Tibet Plateau. We found that M. himalayana populations are divided into two main clusters located in the south and north of the Qinghai-Tibet Plateau. Fourteen DFR genomovars of Y. pestis were found and exhibited a significant region-specific distribution. Additionally, the increased genetic diversity of plague hosts is positively associated with human plague outbreaks. This insight gained can improve our understanding of biodiversity for pathogen spillover and provide municipally directed targets for One Health surveillance development, which will be an informative next step toward increased monitoring of M. himalayana dynamics.

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.