counts of aerobic microorganisms and
S. aureus counts in foods. A 25-g food sample was placed in a
blender jar containing 225 ml of 0.1% peptone water and
blended for 1 to 2 min, after which serial decimal dilutions of
the food homogenate were made in peptone water. Total plate
counts of aerobic microorganisms were determined on tryptic
soy agar plates by the surface spread plate method. Viable S.
aureus counts were determined by plating a total of 1.0 ml of
decimal dilutions onto three plates of Baird-Parker agar,
followed by incubation at 35°C for 48 h (16). Presumptively
identified S. aureus strains were subsequently confirmed by
microscopic examination, production of both coagulase and
thermonuclease, and anaerobic utilization of glucose and
mannitol (15, 16). To estimate the presence of elevated levels