2.4. Isolation of Salmonella from raw milk
25 ml of each well mixed raw milk sample were thoroughly
mixed with 225 ml of sterile buffered peptone water. All
samples were incubated at 35 C for 24 ± 2 h. One hundred
microliters from the pre-enriched sample was transferred to
10 ml of Rappaport Vassiliadis (RV) enrichment broth and
incubated at 43 C for 24 h. Loopfuls from enriched RV broth
were separately streaked onto each of xylose lysine desoxycholate
(XLD) agar and Salmonella- Shigella (SS) agar plates
and incubated at 37 C for 24 h. Two or three of typical or a
typical colonies (colorless with black center on SS standard
colonies with black center on XLD) were selected from each
selective medium and streaked onto nutrient agar slope
which incubated at 37 C for 24 h for further biochemical and
serological identification.