Ciprofloxacin and nalidixic acid resistance of Salmonella spp. isolated from retail food in Poland

MIC values of two isolates harboring qnrS1without any substitutions were 32 mg/L (NA) and 0.5-1.0 mg/L (CIP). The highest MIC values for NA and CIP were observed in two isolates of Salmonella spp. carrying double substitutions in gyrA: Ser83Phe + Asp87Tyr and parC: Thr57Ser + Ser80Ile. MIC value for NA was 2048 mg/L while for CIP - 16 mg/L.