Severe Infection of Nippostrongylus brasiliensis in Bandicota bengalensis Inhabiting Commensal Areas of Punjab, India: Prevalence, Risk Factor Analysis, Molecular Identification and Phylogenesis.

Abstract

The present study aimed to record the prevalence, risk factors, molecular identification, and phylogeny of Nippostrongylus brasiliensis found in the small intestine of the lesser bandicoot rat, Bandicota bengalensis, a wild rodent species. A total of 100 bandicoot rats live trapped at two commensal urban locations (50 each), i.e., a fish market and railway station, in Ludhiana, Punjab State (India), from November 2020 to October 2021, were analysed for the presence of N. brasiliensis, a nematode parasite of zoonotic importance. Overall, the small intestine of 43.00% of the rats was found severely infected with bright red coloured adult N. brasiliensis of both sexes (total of 1439 specimens). Faecal samples contained ellipsoidal and thin-shelled eggs measuring 62.25-74.70m in length and 33.20-37.35m in breadth. No significant (P > 0.05) effect of host age, sex, or season was observed on the rate of infection. The parasite intensity and mean abundance ranged from 27.68-38.04 and 10.52-18.26, respectively, indicating a high risk of disease transmission. Based on the morphology, the nematode parasite was identified as Nippostrongylus sp. Molecular identification was confirmed through PCR amplification of the mitochondrial cytochrome oxidase I gene, which showed a single band of approximately 355bp. A comparison of the present isolate with the available sequences of Nippostrongylus species across the globe showed 100% nucleotide homology with N. brasiliensis sequences available in GenBank from Japan (AP017690), the USA (U57035), and New Zealand (NC033886). The study indicates that B. bengalensis inhabiting commensal urban areas is a reservoir host for N. brasiliensis, which if transmitted to humans and animals visiting the area may pose a potential health risk. The study thus suggests proper rodent population management close to human habitations to avoid the transmission of disease-causing agents.