Wildlife Trade and Genetic Basis of Disease Susceptibility: A Review.

Investigating Bacillus anthracis genomic diversity and trait-specific lineages in an endemic area in northern Tanzania through a combination of traditional and culture-free sequencing approaches

Anthrax, caused by Bacillus anthracis (BA), is a prominent neglected zoonosis with major impacts on human, livestock, and wildlife health. Despite this, limited genomic investigation at the One Health interface constrains current understanding of BA transmission and of the ecological and host factors shaping its diversity and population structure. This includes the possibility of host-specific BA lineages, given that anthrax outbreaks often disproportionally affect individual species. This study characterises the genomic diversity of BA in an endemic area, the Ngorongoro Conservation Area (NCA), in northern Tanzania. We analysed 213 BA genomes from livestock, wildlife and humans from cultured isolates combined with a culture-free targeted capture (TC) approach. NCA sequences formed a distinct genetic cluster compared with those from surrounding areas, and we observed surprisingly high levels of strain diversity within apparent epidemiological clusters, as well as within single animals, though strain diversity was lowest at the within host scale. We found limited evidence for seasonal clustering of cases as well as for BA lineages clustering by host species. This indicates that disproportional impacts on certain species during outbreaks are more likely driven by host ecology factors or, hypothetically, by accessory parts of the bacterial genome not represented in our data. TC-derived data significantly expanded the range of host species and geographic locations for genomic analysis, demonstrating the value of this approach. Although TC data may contain artefactual variation, shared SNP profiles between isolate- and TC-derived genomes gave confidence in its use for genotyping. Our analysis demonstrates unexpectedly high BA strain diversity and limited population structure in this endemic area across a range of spatial scales, including within-host. It further highlights the need for high density sampling and adaptable sequencing strategies to generate adequate BA genomic datasets that can enable informative molecular epidemiological studies of anthrax at the One Health interface.

Genetic Determinants of Infectious Diseases in the Qatari Population

Background and Objectives: Human populations show striking phenotypic disparities in traits and diseases, including responses to infectious diseases (IDs). The impact of host genetic diversity on infection susceptibility and outcomes is increasingly recognized, yet remains largely unknown in Qatar. Here, we explored the distribution of infection-related host genetic variants in Qatar. Materials and Methods: Infection-related genetic variants from the GWAS Catalog were analyzed in 6047 Qatari whole genomes from the Qatar Genome Program (QGP) and compared with populations from the 1000 Genomes Project (1000G). Results: Out of 272,610 GWAS Catalog associations, 1086 were related to ID susceptibility, resistance, severity, progression, clearance, response to treatment, or vaccination, and hence included in the subsequent analysis. A significant heterogeneity in the allelic frequencies (AFs) between Qatari (n = 6047) and the 1000G populations (n = 2504) was observed. The QGP cohort carries significantly lower AFs of most risk variants associated with susceptibility to tuberculosis, malaria, hepatitis, diarrheal disease, and shingles (up to 222-fold, p < 0.0001). Contrarily, an enrichment in the AFs of variants that increase the risk of chickenpox, plantar warts, pneumonia, urinary tract infections (UTIs), and leprosy was observed among Qatari individuals, yet with much smaller-fold differences (≤5-fold, p < 0.0001). In addition, most severity/chronicity-related variants were considerably less prevalent in the Qatari population (up to 20.5-fold). Analysis of variants associated with antibody response revealed a distinct genetic distribution, especially in Epstein–Barr virus (EBV) and Chlamydia pneumoniae infections (27.8- and 3-fold, respectively). Moreover, a variable inter-population allelic distribution was observed in SNPs related to measles, mumps, and rubella (MMR), smallpox, and hepatitis B virus (HBV) vaccine response, as well as variants linked to viral clearance, viral load, virus-induced progression to cancer, and response to treatment. Conclusions: These findings reveal substantial differences in pathogen-associated host variants in a diverse Qatari cohort and highlight the need for follow-up validation and future GWAS discovery efforts.

Host and Pathogen Genetic Determinants of Brucellosis in Veterinary–One Health Interface: A Review

Simple Summary Brucellosis imposes heavy economic burdens on livestock and poses a persistent zoonotic threat. Although infection rarely causes death, it commonly triggers abortion and stillbirth; however, the genomic and immunological drivers of this variable clinical outcome are largely unknown. This review brings together scattered findings from genetics, genomics, and transcriptomics to explain how both the animal host and the bacterium shape disease outcome. We highlight practical advances most relevant to veterinary practice: genetic markers that may contribute to breeding programs after independent validation to produce naturally resistant cattle, goats, sheep, and buffalo, and gene-expression signatures that may sharpen diagnosis and disease staging. We also clarify why antimicrobial resistance in Brucella may involve regulatory, metabolic, and chromosomal mechanisms that are not fully captured by classical acquired resistance-gene databases. By identifying where current evidence is strong, weak, or missing, this work offers researchers and practitioners key research priorities for advancing genetics-informed disease control, improving animal welfare, and reducing zoonotic transmission.

Research Progress on the Major Histocompatibility Complex in Herbivores: Structure, Genetics, and Disease Resistance

The major histocompatibility complex (MHC) represents a critical genetic locus that orchestrates adaptive immune responses through antigen presentation and T cell activation, characterized by exceptional polymorphism and species-specific diversity. In herbivores, MHC polymorphisms constitute fundamental determinants of resistance to parasitic, viral, and bacterial infections while serving as crucial indicators of genetic diversity and breeding value in animal populations. Recent advances in high-throughput sequencing technologies, single-cell omics, and population genetics have substantially advanced understanding of MHC gene structure, allelic polymorphism, evolutionary patterns, and associations with disease susceptibility and vaccine responsiveness. This comprehensive review systematically examines the structural characteristics and regulatory mechanisms of MHC genes, their associations with infectious disease resistance, their role in vaccine responses, and their practical applications in molecular breeding programs, conservation genetics, and immunological research. We identify current technical limitations and outline future research directions to establish a robust theoretical foundation for disease resistance breeding and immune regulation strategies in herbivore populations.

Title: Genomic impact of the second plague pandemic on three human populations

Vector-Borne Disease Control in the Anthropocene: Integrating Biotechnology, Genomic Surveillance, and Environmental Management