The aim of this study was to analyse the susceptibility of Enterobacteriaceae strains isolated from food to antibiotics used in human therapy. The tests were conducted on 433 samples of raw and processed meat intended for sale. A total of 114 strains belonging to Enterobacteriaceae were isolated by the classical bacteriological technique. Escherichia, Klebsiella, Serratia, Enterobacter, Proteus, Hafnia, Citrobacter, Salmonella and Shigella were cultured from samples of beef, pork, poultry and ready-made meat products. Antibiotic susceptibility was tested by the mean of E-tests for the following antibiotics: piperacillin, piperacillin with tazobactam, cefotaxime, cefuroxime, imipenem, ceftazidime, gentamycin, tobramycin, ciprofloxacin and trimethoprim with sulfamethoxazole. Over 37% of the strains isolated were resistant to some of these antibiotics, and 34% showed resistance to at least 2 of them. Resistance was observed most frequently to cephalosporins, penicillins and trimethoprim with sulfamethoxazole, which may suggest that these antibiotics are used excessively in veterinary medicine.
The human sera often contain substances which interfere in the course of immunochemical reactions. It is essential for the control sera used to determine concentrations of antigen of the prostate not to contain such ingredients. The aim of this study was to test the control sera, three producers, containing low (N) and high (P) concentrations of prostate antigen (tPSA). As a factor blocking the interfering actions, the TRU Bloc Meridian Life Science, Inc. reagent was used which contains antibodies against mouse protein and rheumatoid factor. The sera with a low concentration of tPSA demonstrated the presence of interfering substances.