Comparison of the Elevated Temperature Plate Count (ETPC) and MPN Procedure to Estimate the Densities of Fecal Coliforms and Escherichia coli in Soft-Shell Clams
The Elevated Temperature Plate Count procedure of Hefferman and Cabelli was assessed to measure the sanitary quality of soft shell clams. The method, compared to the standard MPN procedure, underestimated the densities of fecal coliforms by about 10%. The estimated cell densities of Escherichia coli and Enterobacter aerogenes in saline suspension were about 20% lower than the estimate obtained on nutrient agar plates. Thus, the fecal coliform standard used in the assessment of sanitary quality of clams would need to be modified when the analysis is conducted by the Elevated Temperature Plate Count procedure.