Isolation of Pseudomonas aeruginosa from food and determination of their antibiotic resistance

Despite the fact that Pseudomonas aeruginosa is a well-known opportunist pathogen, it remains an understudied microorganism in the context of food safety. Due to its high adaptation capability, rapid reproduction and minimal growth necessities, P. aeruginosa is a common bacterium in the food chain. The resistance of P. aeruginosa to various antibiotics in clinical isolates has been extensively investigated and in-depth characterized. Conversely, information on food-borne isolates of this genus and species is insufficient. In this study, a total of 208 colonies were isolated from 144 food samples collected from different provinces and subjected to morphological, physiological, and chemical analyses. Based on the results, total 22 isolates obtained from milk (12) and chicken (10) samples and exhibiting characteristics specific to P. aeruginosa were identified at the molecular level using the 16 S rRNA region. The antibiotic resistance profiles of the identified isolates were evaluated against azithromycin and erythromycin (macrolides), cefoperazone and ceftazidime (cephalosporin), meropenem and imipenem (carbapenem), as well as amikacin (aminoglycoside) among others. As a result of 16 S rRNA analysis, it was determined that only the 10 isolates obtained from raw milk samples were P. aeruginosa. The prevalence of antibiotic resistance among P. aeruginosa isolates was found to be variable. All isolates were observed to be susceptible to amikacin, imipenem, and piperacillin/tazobactam, while they were resistant to erythromycin, nalidixic acid, ampicillin, kanamycin, and chloramphenicol. Only the RM16 strain was susceptible to tetracycline, RM18 to meropenem, and RM20 and RM24 showed intermediate susceptibility to gentamicin. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.