. Detection, isolation and identifcation of Enterobacter sp.
The procedure of FDA (2002) for detection, isolation, and identiWcation of E. sakazakii and other Enterobacter sp. in food and environmental samples was followed.
An aliquot (10ml) of homogenate sample (10 g of powder/90ml sterile Peptone water) or swab sample was added to 90ml Enrichment Broth (EE broth) which contains bile salt and brilliant green to suppress the growth of non- Enterobacteriaceae. The bottles were then incubated for 14–16 h at 36 C. Two plates of Violet Red Bile Glucose Agar (VRBGA) were inoculated (0.1ml) by streak method form the EE
broth culture. Another loopful of the suspension was streaked on VRBGA. The plates were incubated for 14–16 h at 36 C. Five colonies of the red or purple colonies surrounded by purple halo were examined morphologically. E. sakazakii and other Enterobacter sp. grown on VRBGA appeared under microscope as short-rods in shape and was Gram negative. Typical colonies were streaked on Tryptic Soya Agar (TSA), plates were incubated for 24– 72 h at 25 C. The isolated colonies that produce yellow pigment were identifed using API 24E test. To avoid the lack of speciWcity of the FDA procedure for the isolation of E. sakazakii (Iversen et al., 2004), E. sakazakii isolates were confrmed by growing them on Druggan-Forsythe-Iversen (DFI) medium. E. sakazakii ATCC 51329 was used as the positive control
organism. The non E. sakazakii isolates were also identifed.