Microbial Biofilm Diversity and Prevalence of Antibiotic Resistance Genes in Drinking Water Distribution System of Peshawar, Pakistan

• Main Authors: Habib Ullah, Muhammad Shahzad, Faizan Saleem, Taj Ali, Muhammad Kamran Azim, Haris Khan, Johar Ali, Jawad Ahmed
• Format: Article
• Language: English
• Published: MDPI AG 2021-06-01
• Series: Water
• Subjects: shotgun metagenomic sequencing; bacterial diversity; core species; functional potential; resistome
• Online Access: https://www.mdpi.com/2073-4441/13/13/1788

The occurrence of microbial communities harboring antibiotic resistance bacteria and antibiotic resistance genes in the drinking water distribution system pose a significant threat to the aquatic ecosystem and to public health, especially in developing countries. In this study, we have used next-generation sequencing technology to explore bacterial community diversity and the abundance of antibiotic resistance genes in biofilms collected from the drinking water distribution system of Peshawar, the capital city of the Khyber Pakhtunkhwa province of Pakistan. The results showed that <i>Proteobacteria</i> were the most abundant phyla (89.79%) in all biofilm samples, followed by <i>Bacteroidetes</i> (3.48%) and <i>Actinobacteria</i> (2.79%). At genus level, <i>Pseudomonas</i> was the most common (22.45%) in all biofilm samples. Overall, bacterial diversity and richness was higher in biofilm samples collected from the consumer end than the source site. Bacterial diversity was also dependent on the piping material (GI vs. PVC) and water supply (direct vs. indirect). Functional annotation reveals a differential abundance of common metabolic pathways at source and consumer end. Resistome analysis revealed a prevalence of resistance genes against 12 classes of antibiotics in all samples with macrolides resistance being the commonest at the consumer end (42.1%) and fluoroquinolone resistance at the source end (24%). To our knowledge, this is the first study that provides new insight and evidence into the microbial community diversity and antibiotic resistance in the drinking water supply system of Peshawar. These findings may ultimately help the authorities to design and implement effective strategies for controlling biofilms and ensuring a continuous supply of safe drinking water to the community.