Molecular characterisation of adenoviruses in sewage and farm waste water samples in Punjab, India

This study aimed to investigate the occurrence and genotype distribution of Human adenovirus (HAdV), Bovine adenovirus (BAdV), and Porcine adenovirus (PAdV) in environmental waters, with a focus on their association with water contamination and potential use in microbial source tracking in Punjab, Northern India. A total of 52 samples were collected from three different river stretches. Using nested PCR, BAdVs were detected in 16% of the samples, while HAdVs and PAdVs were found in 32 and 11% of the samples, respectively. The isolated serotypes included HAdV type 40/41, BAdV type 8/6/5/4//2, and PAdV type 3/5, with HAdV-41 being the most prevalent. Notably, multiple BAdV asymptomatic infections were observed among herds, although their implications for livestock health remain uncertain. BAdV-8 and BAdV-6, the predominant types identified, have been associated with specific clinical conditions in Punjab. Phylogenetic analysis of PAdV indicated a high nucleotide sequence identity (95.4 to 100%) among viruses detected in wastewater samples. This study represents the first investigation into the epidemiology and molecular characterisation of PAdV in porcine farm wastewater in India. Additionally, evidence of recombination among livestock adenoviruses was found, highlighting the need for continued genetic surveillance of animal AdV. These findings underscore the importance of considering BAdV and PAdV detection in fecal source attribution in environmental samples. Overall, this study provides valuable insights into the occurance, diversity, and genetic characteristics of adenoviruses in agricultural and environmental settings.