2.5. Isolation and identification of Y. enterocolitica and
A. hydrophila from raw milk samples
25 ml from the collected raw milk samples were added to
sterilized tubes containing 225 ml of BPW and incubated
aerobically at 37 C for 24 h. All enrichments were streaked
onto XLD, incubated at 32 C for about 18 h, SS agar, was
incubated at 30 C for about 24 h, while MCA agar was incubated
at 25 C for 24 h. Each colonial type present was selected
with neither fewer than two nor more than four colonies per
plate used to individually inoculate Simmon's citrate agar,
Christensen's urea agar and were incubated overnight at 28 C.
Isolates exhibiting typical reactions “Citrate eve, urease þ ve
were subjected to additional biochemical API 20E system
(BioMerieux) to confirm identification as Y. enterocolitica and A.
hydrophila.