Characterization of oral microbiome from black rat (Rattus rattus) and assessment for pathogenicity

Abstract

The present study, conducted from August to November 2022 in district Okara, Pakistan, focused on assessing the bacterial characterization in oral saliva swabs of black rats (Rattus rattus). DNA extraction was performed using the QIAamp DNA Microbiome kit, and the 16S rRNA gene was amplified using universal primers to amplify variable regions (V) V1 to V8 of 1380 bp. The identified bacterial phyla were as follows: Proteobacteria 98%, Firmicutes 1%, Actinobacteria 0.4%, and Bacteroidetes 0.05%. The bacterial classes included Gammaproteobacteria 95%, Alpha Enterobacterales 3%, and Bacilli 1%.  The relative abundance of different bacterial orders was Pseudomonadales 40%, Enterobacterales 30%, Xanthomonadales 25%, Sphingomonadales 3%, Lactobacillales 1%, Micrococcales 0.4%, and Bacteroidales 0.05%. The identified families followed the order of Pseudomonadaceae 40%, Enterobacteriaceae 30%, Xanthomonadaceae 25%, and Sphingomonadaceae 3%. The percentage distribution of Pseudomonas was 40%, Stenotrophomonas 25%, Sphingomonas 3%, Pantoea 2%, and Porphyromonas 0.05%. This knowledge enhances our understanding of bacterial infections in rodents, serving as crucial baseline data for bacterial species. The high prevalence of potentially pathogenic bacteria like Pseudomonas suggests a significant risk of zoonotic diseases that could affect both local wildlife and human populations. It is crucial that future studies should focus on identified bacterial communities in other rodent species and small mammals to compare their roles in disease ecology. This ongoing research could identify specific species that are particularly significant in zoonotic transmission, thereby guiding future studies and public health measures.