What is already known about this topic? There were a total of 4 and 3 human plague cases that occurred in the Inner Mongolia Autonomous Region in 2019 and 2020, respectively, with 1 and 2 deaths in 2019 and 2020 respectively, which indicated that plague still poses a significant threat to human health especially for farmers, shepherds, or residents living in native plague foci. What is added by this report? On August 14, 2021, 1 patient from the Otog Qi (County) in the Inner Mongolia sought treatment in Yinchuan City (the capital of Ningxia Hui Autonomous Region), where the patient was diagnosed with bubonic plague and secondary septicemic plague. The genetic source tracking of associated Yersinia pestis strains indicated that human plague cases were infected from animal reservoirs in Inner Mongolia. What are the implications for public health practice? Major threats of plague to residents living in native plague foci is the infection by bites of bacterium-bearing fleas or direct contact with diseased or dead plague-infected animals. And the ability of early diagnostic is very critical for county-level hospital in native plague foci.

Bartonella are generally recognized as zoonotic pathogens of mammals, including many rodent species. However, data on the genetic diversity of Bartonella in some regions are still absent in China. In this study, we collected rodent samples (Meriones unguiculatus, Spermophilus dauricus, Eolagurus luteus, and Cricetulus barabensis) from Inner Mongolia located in Northern China. The Bartonella were detected and identified by sequencing the gltA, ftsZ, ITS, and groEL genes in them. An overall 47.27% (52/110) positive rate was observed. This may be the first report that M. unguiculatus and E. luteus harbor Bartonella. Phylogenetic and genetic analysis on gltA, ftsZ, ITS, and groEL genes indicated that the strains were divided into seven distinct clades, suggesting the diverse genetic genotypes of Bartonella species in this area. Of those, Clade 5 meets the criteria for identification as a novel species based on gene sequence dissimilarity to known Bartonella species and herein we name it “Candidatus Bartonella mongolica”.

Ehrlichia are intracellular bacteria of medical importance to both humans and domestic animals. They are mainly vectored by ticks and harbored by domestic and wild animals such as rodents. In this study, we investigated the prevalence and genetic diversity of Ehrlichia in rodents from Inner Mongolia Autonomous Region, Northern China. In 2021, a total of 359 rodents representing 10 species were captured in two locations of Inner Mongolia: Siziwang Banner and Ar Horqin Banner. Subsequently, an Ehrlichia was detected and characterized in three Spermophilus dauricus and one Meriones unguiculatus. Its rrs, gltA, and groEL sequences have the highest identities of 100%, 87.9%, and 99.7% to known Ehrlichia species, respectively, and they form distinct clades in the phylogenetic trees. Ehrlichia strains mostly related to this species have been detected in ticks from Russia, sug-gesting that it may be exposed to humans and animals through tick bites. The pathogenicity of this Ehrlichia should be further studied.

According to WHO, plague, caused by Yersinia pestis, has resurged since 2000. Inner Mongolia, harboring a quarter of China’s plague foci, has accounted for 80% of national plague cases in the past five years. Despite its pivotal role in Chinese plague epidemiology, the genetic diversity and transmission dynamics of Y. pestis in this region remain under-investigated. Our analysis of 585 Y. pestis strains from Inner Mongolia (1948–2021) revealed three primary lineages, with 2.MED3 being predominant. We further delineated seven sub-phylogroups in 2.MED3, with 2.MED3.1.2 and 2.MED3.1.4 showing recent dominance. These two subgroups reveal dual transmission patterns: localized short-distance spread and long-distance dispersals over 300 km. Xilingol League is highlighted as a key source and reservoir for Y. pestis, predominantly spreading from central-eastern to southwestern Inner Mongolia, including occasional reverse transmissions. These findings enhance understanding of Y. pestis diversity and transmission in Inner Mongolia, aiding in enhanced surveillance and control measures.

Plague persistence relies on complex host–vector–environment interactions, yet the ecological contribution of soil microbiomes to natural foci remains poorly understood. We performed shotgun metagenomic sequencing of 143 soil samples across four distinct plague foci in Inner Mongolia, China, to characterize microbiome features associated with contrasting epidemiological states. Taxonomic, functional, and network analyses showed that the three active plague foci exhibited lower microbial diversity, simplified co-occurrence networks, and enrichment of specific taxa, particularly Streptomyces. Conversely, the quiescent Marmota sibirica focus harbored a more complex and interconnected microbial network with greater richness and exclusive detection of Yersinia bacteriophages, showing significant concordance with bacterial community structure. These patterns indicate distinct microbiome configurations associated with specific host and geographic settings, highlighting the need to disentangle host- and site-specific effects from broader epidemiological status. Compared with surface and deep soil, burrow-associated soil exhibited greater microbial differentiation and higher richness of bacteriophages, antimicrobial resistance genes, and virulence-associated genes, suggesting its potential as a sensitive environmental matrix for ecological monitoring. Overall, our findings identify distinct soil microbiome signatures—specifically taxonomic shifts, altered network complexity, exclusive Yersinia phage detection, and functional gene enrichment—associated with epidemiological heterogeneity across natural plague foci, providing a baseline for understanding ecological variation among endemic habitats.

Introduction: Ketosis is a common metabolic disease in periparturient dairy cows. Monitoring and early warning based on blood indicators have become a key research focus in this field. Current diagnosis mainly relies on detecting plasma β-hydroxybutyric acid (BHBA). This study aims to explore the pathogenesis of ketosis at the blood genetic level, with the goal of achieving the early warning and prevention of the disease. Methods: According to China’s “gold standard” diagnostic method for dairy cow ketosis, blood samples were collected from different groups. Biochemical and oxidative stress indicators were then measured to evaluate organ function. Transcriptome sequencing analysis was performed on healthy cows and sick cows (both pre- and post-onset) to identify differentially expressed genes (DEGs). The functions of DEGs and their enriched pathways were analyzed through GO and KEGG pathway analyses. Weighted Gene Co-expression Network Analysis (WGCNA) was used to analyze the transcriptomic data, identify co-expression modules, and explore the relevance between these modules and the traits associated with ketosis occurrence. A dual standard curve method was established with the AHR gene as the core for early warning and detection. Then the specificity, sensitivity, and repeatability of the primers were validated. Finally, the method was applied to detect both positive samples (diseased cows) and healthy dairy cow samples to analyze the relative expression level of the AHR gene and the prediction accuracy. Results: Three biochemical indicators BHBA, non-esterified fatty acid (NEFA), and glucose (GLU) were identified as key diagnostic markers for ketosis in postpartum dairy cows. Changes in NEFA and GLU levels prior to parturition may indicate the risk of ketosis. A large number of DEGs were screened out, among which the AHR gene was identified as a candidate molecular marker gene for ketosis prediction. The early warning and detection method based on the AHR gene demonstrated high primer specificity, and the detection method itself exhibited excellent specificity, sensitivity, and repeatability. The prediction accuracy for healthy dairy cows reached 91.11%. Discussion: This study demonstrates that the detection method established based on the AHR gene is efficient and reliable, effectively distinguishing between early ketosis individuals and healthy ones based on gene expression differences. This study provides an efficient and reliable technical tool for the early warning of ketosis in dairy cows.