Comparison of the SimPlate™ Total Plate Count Method with Petrifilm™, Redigel™, and Conventional Pour-Plate Methods for Enumerating Aerobic Microorganisms in Foods

Abstract

The SimPlate Total Plate Count (TPC) method, developed by IDEXX Laboratories, Inc., is designed to determine the most probable number of aerobic microorganisms in foods. The 24-h test was compared to the conventional plate count agar (PCA) method, the Petrifilm Aerobic Count plates, and the Redigel Total Count procedure for enumerating microflora in 751 food samples. Results using the SimPlate TPC method were highly correlated (r > or = 0.96) with results from other test methods. Slopes (0.96-0.97) were not significantly different from 1, and y intercepts (-0.03-0.08) were not different from O. The SimPlate has a high counting range (> 1600 most probable number per single dilution), thus requiring fewer dilutions of samples compared to other methods evaluated. Some foods, e.g., raw liver, wheat flour, and nuts, contain enzymes that gave false-positive reactions on SimPlates. Overall, however, the SimPlate TPC method is a suitable alternative to conventional PCA, Petrifilm, and Redigel methods for estimating populations of mesophilic aerobic microorganisms in a wide range of foods.

Avaliação do padrão coliformes a 45ºC e comparação da eficiência das técnicas dos tubos múltiplos e Petrifilm EC na detecção de coliformes totais e Escherichia coli em alimentos

“…Alguns países como estados Unidos, Canadá, Austrália, Coréia, Portugal, Noruega, itália, entre outros, desenvolveram trabalhos e estudos colaborativos para avaliar a eficiência das placas Petrifilm e de outros métodos rápidos em relação aos métodos convencionais [6,7,8,11,16,19,23,24,29].…”

Performance of two ready-to-use systems for enumeration of aerobic mesophilic microorganisms in frozen goat milk

“…Simplate TM plates have also been submitted to equivalence studies and good correlation indexes were also reported (3,11,15,22,29,30). The correlation indexes found for Petrifilm TM AC plates for the enumeration of mesophilic microorganisms in pasteurized frozen goat milk, compared with the conventional pour-plate method, and the correlations observed in other studies in the literature are presented in Table 2; those for Simplate TM TPC and pour plates, in Table 3, and those for Petrifilm TM AC and Simplate TM TPC, in Table 4.…”

Assessment of the efficiency of SimPlate™ total plate count color indicator (TPC CI) to quantify mesophilic aerobic microorganisms in pasteurized milk

“…The culture medium contained various substrates that when metabolized released a fluorescent substance (4). In pasteurized milk, the SimPlate™ TPC showed variations in the fluorescence intensity of the positive wells, causing doubt in the readings and low correlation with the standard MAM counting method (1).…”