Diversity of Antimicrobial Resistance and Virulence Determinants inPseudomonas aeruginosaAssociated with Fresh Vegetables

Abstract

With the increased focus on healthy eating and consuming raw vegetables, this study assessed the extent of contamination of fresh vegetables byPseudomonas aeruginosain Jamaica and examined the antibiotic susceptibility profiles and the presence of various virulence associated determinants ofP. aeruginosa. Analyses indicated that vegetables from retail markets and supermarkets were widely contaminated byP. aeruginosa; produce from markets were more frequently contaminated, but the difference was not significant. Lettuce and carrots were the most frequently contaminated vegetables, while tomatoes were the least. Pigment production (Pyoverdine, pyocyanin, pyomelanin and pyorubin), fluorescein and alginate were common in these isolates. Imipenem, gentamicin and ciprofloxacin were the most inhibitory antimicrobial agents. However, isolates were resistant or showed reduced susceptibility to ampicillin, chloramphenicol, sulphamethoxazole/trimethoprim and aztreonam, and up to 35% of the isolates were resistant to four antimicrobial agents. As many as 30% of the isolates were positive for thefpv1gene, and 13% had multiple genes. Sixty-four percent of the isolates harboured an exoenzyme gene (exoS,exoT,exoUorexoY), and multiple exo genes were common. We conclude thatP. aeruginosais a major contaminant of fresh vegetables, which might be a source of infection for susceptible persons within the community.