Metagenomic profiling of microbial communities and the resistome within Egyptian hospital wastewater and tap water

Antimicrobial resistance (AMR) is a worldwide health concern that compromises the successful treatment of a growing array of infectious diseases, particularly in low- and middle-income countries. AMR is exaggerated by the spread of antimicrobial resistance genes (ARGs) across humans, animals, and environmental reservoirs like water and soil. Hospital wastewater (HWW) is the main source of antimicrobial resistance in the environment. The current study used high throughput metagenomic nanopore sequencing to investigate the microbial abundance and ARGs associated with both HWW and tap water in five different hospitals in Cairo, Egypt. The bacterial community composition of the HWW microbiome identified 25 taxonomic families. The most abundant genera in HWW were Acinetobacter (6%) and Propioniciclav (5%) out of 101 unique genera while, the most abundant in tap water were Enterococcus (53%), Escherichia (15%), and Francisella (14%) out of 89 unique genera. Alpha diversity analysis revealed significantly greater microbial diversity in the HWW samples than in the tap water samples (P value > 0.05), moreover beta diversity analysis revealed a significant difference in the microbial community composition between the tap water and HWW samples (P value > 0.05) using Chao metric for richness estimation and Shannon metric for richness and evenness estimation. Total ARG analysis revealed absence of ARGs in tap water using the three databases, while comparable levels of ARGs were detected in HWW across the five hospitals. In total, 45, 28, and 28 ARG subtypes were identified in the HWW samples using ResFinder, CARD, and the NCBI AMRFinderPlus databases, respectively. The most abundant AMR mechanisms among the five hospitals were linked to the inhibition of protein synthesis. Using the ResFinder database, streptogramin resistance genes were most prevalent in Hospitals 1 and 5 (15% and 40%, respectively); using CARD, aminoglycoside, lincosamide, and macrolide resistance genes were most predominant (relative abundances 35-60%). Using NCBI AMRFinderPlus, streptomycin, tetracycline, and macrolide resistance genes were most prevalent (relative abundances 30.1-60%). Detection of plasmid replicons in HWW identified 39 different plasmid-associated replication genes via the PlasmidFinder database. The Col440l-1, colRNAI-1 and Col440ll-1 plasmid replicons were the most detected across the five hospitals with relative abundances of 16.6%, 10.9% and 9.6%, respectively. This study revealed different microbial communities among HWW and tap water in addition to the widespread occurrence of ARGs and AMR encoding plasmid replicons in the HWW in the five different hospitals in Cairo, Egypt indicating a significant risk associated with HWW, necessitating the implementation of preventative measures to avert their environmental diffusion. To our knowledge, this is one of the first Egyptian studies to apply Oxford Nanopore long-read metagenomic sequencing for simultaneous profiling of microbial communities and the resistome in HWW and tap water, using three ARG databases across five hospitals in two seasons.