nalidixic acid (30), ciprofloxacin (5), amoxicillin (25); ticarcillin (75); cephalothin (30); ceftazidime (30); streptomycin (10); sulphamethoxazole/trimethoprim (25); tetracycline (30); gentamicin (10) and colistin sulfate (50). For the antibiotics Amoxicillin and colistin sulfate, which are not included in the CLSI list, the following criteria were used: S 21/R < 14 and S 10/R < 10, respectively. Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853 were used as a control strains.