Determination of siderophore production, serum resistance, production of extended spectrum beta-lactamase (ESBL) and antibiotic resistance of Pseudomonas species isolated from various of food products

In this research; we examined 20 raw milk samples collected from various villages of Ankara, 20 white cheese, 20 icecream, 20 minced meat, 20 meat in small pieces, 20 chicken breast collected from different sale points in Ankara, as material between March 2008 and December 2009. Pseudomonas species were isolated from food samples and identified with Becton Dickinson (BD) BBL Crystal Identification Systems and Enteric/Nonfermenter ID Kit. Identified Pseudomonas species were analysed in terms of virulence factors such as siderophore production and serum resistance. Furthermore production of extended spectrum beta-lactamases (ESBL), inducible beta-lactamases (IBL) and antibiotic resistance characteristics were analysed. The rate of distribution 154 Pseudomonas strains, isolated from food samples, was 57 (37,0%) P.aeruginosa, 52 (33,8%) P.fluorescens, 43 (27,9%) P.putida, 2 P. stutzeri (1,3%). It was determined that 154 Pseudomonas isolates (100%) siderophore producers. 117 (76,0%) of total 154 Pseudomonas isolates were determined as resistant to human serum. Detection of extended spectrum of beta-lactamases (ESBL) was made with double disc synergy method and none of Pseudomonas isolates were established ESBL producers. Detection of inducible beta-lactamases (IBL) was made with disc induction method and 35 (22,7%) of total 154 Pseudomonas isolates were found as IBL producers. Antibiotic sensitivities of Pseudomonas isolates were detected Kirby-Bauer disc diffusion method. The distribution of antibiotic resistances of Pseudomonas isolates was 89 (%57,8) cefotaxime, 87 (%56,5) azteronam, 58 (%37,7) ceftriaxone, 41 (%26,6) ticarcillin/clavulonic acid, 4 (%2,6) colistin, 4 (%2,6) ceftazidime. All Pseudomonas isolates were determined as susceptible to ciprofloxacin, gentamicin and piperacillin.