One milliliter of the mixture was transferred to 10 mL Rappaport and Vassiliadis Broth (Merck 1.07700) and incubated for 13-24 h at 42 ◦C. Another 1 mL of the mixture was transferred to 10 mL of selenite cystine broth (Merck 1.07709) and incubated for 24 h at 35–37 ◦C for selective enrichment.