Detection of antibiotic-resistant bacteria and resistance genes SHV, TEM, and CTX-M in drinking waters in Tehran, Iran

Nowadays, a difficult problem has been disrupting people's health through treated and untreated water, namely the existence of antibiotic-resistant bacteria in these environments. The first is such organisms’ ability to acquire resistance genes through genetic elements, and the second seems to be the substances’ potential toxicity. The health index of supply water is lacking for bacteria such as coliform bacteria, Escherichia coli, Pseudomonas aeruginosa, and intestinal enterococci. The study's main aim was to figure out how these bacteria function as antibiotic resistance pools, not only to find resistant genes like SHV, TEM, and CTX-M but also to depict the dendrogram of clones in water supply samples in Tehran. Over the course of a year, 17 strains of P. aeruginosa were analyzed. In this study, 94.1% of the isolates tested positive for the TEM gene, while only one isolate tested positive for the CTX-M gene, and none tested positive for the SHV gene. This research shows that P. aeruginosa is not as common in drinkable water as previously thought. Nevertheless, it appears that P. aeruginosa can spread acquired antibiotic resistance vertically rather than horizontally. HIGHLIGHTS Pseudomonas aeruginosa is not as common in drinkable water in Tehran.; P. aeruginosa can spread acquired antibiotic resistance vertically rather than horizontally.; One isolate of Bacillus, two isolates of Enterococcus, one isolate of P. mendocina, and 13 isolates of P. aeruginosa were isolated.