Prevalence and Antibiotic Resistance Phenotypes of Pseudomonas spp. in Fresh Fish Fillets

In fresh fish products, excessive loads of Pseudomonas can lead to their rapid spoilage. It iswise for Food Business Operators (FBOs) to consider its presence both in whole and prepared fishproducts. With the current study, we aimed to quantify Pseudomonas spp. in fresh fillets of Salmosalar, Gadus morhua and Pleuronectes platessa. For all three fish species, we detected loads ofpresumptive Pseudomonas no lower than 104 –105 cfu/g in more than 50% of the samples. We isolated55 strains of presumptive Pseudomonas and carried out their biochemical identification; 67.27% ofthe isolates were actually Pseudomonas. These data confirm that fresh fish fillets are normallycontaminated with Pseudomonas spp. and the FBOs should add it as a “process hygiene criterion”according to EC Regulation n.2073/2005 n.2073/2005. Fu rthermore, in food hygiene, it is worthevaluating the prevalence of antimicrobial resistance. A total of 37 Pseudomonas strains were testedagainst 15 antimicrobials, and they all were identified as being resistant to at least one antimicrobial,mainly penicillin G, ampicillin, amoxicillin, tetracycline, erythromycin, vancomycin, clindamycinand trimethoprim. As many as 76.47% of Pseudomonas fluorescens isolates were multi-drug resistant.Our results confirm that Pseudomonas is becoming increasingly resistant to antimicrobials and thusshould be continuously monitored in foods.