AOAC 2018 Methods

AOAC Official Method 2018.05 Enumeration of Enterobacteriaceae in Select Foods and Environmental Surfaces Peel Plate EB First Action 2018 [Applicable to the enumeration of bacteria in the family Enterobacteriaceae that comprise a broad

number of Gram-negative bacteria from pasteurized whole milk, butter, non-fat dry milk, vanilla ice

cream, powdered and liquid infant formula (milk based) containing probiotic, non-probiotic liquid infant

formula (soy-based), infant cereal with probiotics, infant rice cereal without probiotic, chicken carcass

rinse with neutralized buffered peptone water, chicken carcass rinse with buffered peptone water, and

stainless-steel surfaces.]

Caution: Perform tests with clean washed and gloved hands assuming potential pathogenic bacteria.

Microbiological cultures and reagents should be collected into biohazardous bags and autoclaved.

Dispose according to local, state, and federal regulations.

See Table 2018.05 for results of the interlaboratory study supporting acceptance of the method. A. Apparatus ( a ) Peel Plate EB .—Cat. No. PP-EB-100K, 100 Peel Plate EB tests; PP-EB-1000K, 1000 Peel Plate EB Tests (Charm Sciences, Inc., Lawrence, MA, USA). Test kit components: Two foil bags containing 50 Peel Plate

EB each with blue indicator desiccants.

( b ) 1 mL pipet tips . ( c ) 1 mL pipettor . ( d ) 37 ± 1°C incubator, depending on test matrix .

( e ) Light box for back illuminating and counting plates . ( f ) Magnifying glass 2x or 4x for examining plates . ( g ) Stomacher- Seward 400 paddle type or equivalent B. Reagents ( a ) Butterfield’s Phosphate Buffered Dilution Water (BPBDW).—Buffer KH 2 PO 4 (34 g to 500 mL distilled