Comparative metagenomic analysis of bacterial communities across rodents, dogs, and humans: Insights into public health and one health outlooks

Rodents are key reservoirs and vectors of zoonotic pathogens that impact both animal and human health. In regions such as Ngorongoro District, where wildlife, domestic animals, and humans frequently interact, these close contacts facilitate the transmission of infectious diseases. In this study, we employed metagenomic next-generation sequencing, utilizing both nanopore and Illumina platforms, to detect zoonotic, opportunistic, and environmental bacteria in 530 blood samples collected from 230 rodents, 100 domestic dogs, and 200 humans. In rodents, the zoonotic and opportunistic bacteria identified included Helicobacter spp., Campylobacter spp., Pseudomonas spp., Francisella spp., Listeria spp., Klebsiella spp., Proteus spp., Providencia spp., Morganella spp., Enterococcus spp., and Bibersteinia spp. In domestic dogs, the bacteria detected were Mycoplasmopsis spp., Staphylococcus spp., Helicobacter spp., Capnocytophaga spp., and Streptococcus spp. Human blood samples revealed the presence of Klebsiella pneumoniae , Cronobacter sakazakii , Staphylococcus spp., Enterococcus spp., Providencia spp., Finegoldia spp., Streptococcus spp., Mycoplasma spp., Aeromonas spp., and Francisella spp. Several zoonotic bacteria were detected across multiple host species. Klebsiella pneumoniae , Providencia rettgeri , and Francisella hispaniensis were identified in both humans and rodents, while Staphylococcus cohnii was detected in both humans and dogs. Notably, Proteus spp., Mycoplasma spp., Streptococcus spp., and Enterococcus spp. were present in all three hosts: rodents, dogs, and humans. The detection of these bacteria highlights significant public health risks and underscores the urgent need for enhanced surveillance, improved sanitation, and community education. Our findings emphasize the interconnectedness of animal and human health, reinforcing the critical importance of a One Health approach in the management of zoonotic diseases and the safeguarding of public health.