Then samples were appropriately diluted 10 folds in peptone water (0.1%, w/v) and 100 μl of each dilution was plated on PALCAM agar (Alpha Bioscience, Baltimore, USA) containing acriflavine
(5 mg/l), polymyxin B (10 mg/l) and ceftazidime (8 mg/l) and the plates were incubated at 37 °C for 48 h.