1. The antimicrobial most frequently involved in observed resistance patterns was nalidixic acid.

2. Prepare Acriflavin and nalidixic acid supplements as 0.5% (w/v) stock solutions in distilled water

3. 07/01/21: Meprobamate: Cep 2009-322: 07/01/21 Nalidixic acid: Cep 2009-216: 07/01/21

4. Gram stain, oxidase, catalase, growth at 25°C, nalidixic acid and cephalothin resistance, hippurate, and indoxyl acetate hydrolysis.

5. The reduced capacity for growth is due to a metabolic-drift mutation induced by exposure to a combination of nalidixic acid and rifampicin for a time and under conditions sufficient to induce the mutation.

6. In this protocol, 25 g or ml of the dairy sample is homogenized with 225 ml of selective enrichment medium containing Acriflavin, nalidixic acid, and cycloheximide and is incubated for 48 h at 30 °C