Occurrence and antimicrobial resistance of Salmonella spp. isolated from food other than meat in Poland

Introduction and Objectives. Antimicrobial resistance of pathogenic bacteria can result in therapy failure, increased hospitalization, and increased risk of death. In Poland, Salmonella spp. is a major bacterial agent of food poisoning. The majority of studies on antimicrobial resistance in Salmonella spp. isolates from food have focused on meat products as the source of this pathogen. In comparison, this study examines the antimicrobial susceptibility of Salmonella spp. isolated from retail food products other than meat in Poland. Materials and Methods. A collection of 122 Salmonella spp. isolates were isolated in Poland in 2008-2012 from foods other than meat: confectionery products, eggs, fruits, vegetables, spices and others. The resistance of these isolates to 19 antimicrobial agents was tested using the disc diffusion method. Results. Salmonella Enteritidis was the most frequently identified serotype (84.4% of all tested isolates). In total, 42.6% of the Salmonella spp. isolates were resistant to antibiotics. The highest frequencies of resistance were observed in isolates from 2009 (60.0%) and 2012 (59.5%). Antibiotic resistance was most prevalent among Salmonella spp. isolated from egg-containing food samples (68.0%). Resistance to nalidixic acid was most common and was observed in 35.2% of all tested isolates. The isolates were less frequently resistant to sulphonamides (6.6%), ampicillin (4.9%), amoxicillin/clavulanic acid (2.5%) and to streptomycin, cefoxitin, gentamicin and tetracycline (1.6%). Only one isolate showed resistance to chloramphenicol. Four isolates displayed multiresistance. Conclusions. Although, the level of resistance and multiresistance of Salmonella spp. isolates from non-meat foods was lower than in those from meat products, the presence of these resistant bacteria poses a real threat to the health of consumers.