Antimicrobial resistance and virulence gene profiles of seven Pseudomonas aeruginosa in bottled and large-volume packaged drinking water in Hanoi

Abstract

Pseudomonas aeruginosa is an opportunistic pathogen with high levels of antimicrobial resistance and multiple virulence factors, posing a potential public health risk when present in drinking water. This study was conducted using 50 bottled and large-volume packaged drinking water samples collected in Hanoi to determine the prevalence, antimicrobial resistance characteristics, and virulence gene profiles of P. aeruginosa. The results showed that 38% of the samples were positive for P. aeruginosa. The isolates exhibited high resistance rates to third- and fourth-generation cephalosporins and aminoglycosides, whereas all isolates were susceptible to doripenem and piperacillin-tazobactam (100%). Virulence gene analysis showed that the isolates simultaneously carried multiple genes associated with the type III secretion system (exoA, exoY, exoS, and exoU) and the quorum-sensing system (lasA, lasB, rhlAB, rhlI, lasI, and lasR), indicating a high potential for biofilm formation and pathogenicity. These findings highlight the need for routine microbiological surveillance and stringent quality control of bottled drinking water.