Evaluation of Quick Bacterial Count Methods for Assessment of Food Plant Sanitation

Four methods to detect microbial contamination on food plant equipment surfaces were compared to determine the accuracy, precision, cost and time required to do each test. A standard method for swabbing; a simplified swab test (Millipore Corporation); a contact-transfer method (Con-Tact-It, Birko Chemical Corporation) and a direct method using Rodac plates (BBL) were evaluated. The equipment surfaces were found to be highly contaminated indicating the necessity for regular microbial testing. Under conditions of the test, there was good agreement in enumeration of bacteria between the standard swab test and both the Millipore swab method and the Con-Tact-It system; the standard swab method and Rodac plates showed the best precision. The contact methods were by far the quickest tests to do, and the Con-Tact-It system was the least expensive.