The colonies identified as
Staphylococcus spp. were further tested for co-agulase formation using
Dryspot Staphytect Plus (OXOID,UK). Positive colonieswere considered
to be S. aureus. Round purple colonies grown on Violet Red Bile Glucose
(VRB) agar (OXOID, UK) incubated at 30°C for 48h were tested for gas
production in Lauryl Sulfate Tryptose (LST) broth (OXOID, UK) containing
Durham tubes at 35°C for 48h. The gas producing colonies
were counted as coliforms and then further tested for gas production
by incubation in EC broth containing Durham tubes at 45°C for 48h.