Enumeration of heterotrophs, fecal coliforms and Escherichia coli in water: comparison of 3M™ Petrifilm™ plates with standard plating procedures

Quality of Source Water and Drinking Water in Urban Areas of Myanmar

“…E. coli and total coliform bacteria were incubated at 37°C for 24 hours, and HPC was incubated at 37°C for 48 hours. The validity of this kit has been confirmed [5, 6], and it showed high correlations for E. coli and total coliform. High correlations were also reported for HPC, although small differences can arise with different incubation conditions [7].…”

Comparison of Petrifilm and Colilert methods forE. colienumeration in recreational water

“…The small volume of water (1 mL/sample) used for the Petrifilm test proved to be a disadvantage for the method, restricting the lower limit of detection to 100 colony forming units (CFU)/100 mL (Vail et al 2003). Schraft and Watterworth (2005) found the average confirmed E. coli counts on Petrifilm EC plates were always less than those from membrane filtration, but differences were not statistically different. These researchers, however, did not adhere to the manufacturer's recommended incubation temperature of 35 C for the Petrifilm method.…”

“…These researchers, however, did not adhere to the manufacturer's recommended incubation temperature of 35 C for the Petrifilm method. Instead, Schraft and Watterworth (2005) chose to incubate their tests at 44.5 C, to eliminate nonfecal coliform organisms that typically are not thermotolerant (Orsanco Water Users Committee 1971). In a study comparing a variety of microbiological methods against the reference membrane filtration method for detection of E. coli in water, Petrifilms showed the weakest agreement with the standard method (Horman and Hanninen 2006).…”

Real-Time TaqMan PCR for Rapid Detection and Quantification of Coliforms in Chilled Meat

“…Coliforms are aerobic or facultatively anaerobic, Gram-negative, nonspore-forming rods (Schraft and Watterworth 2005) and are considered relatively harmless. However, some typical coliform strains such as Escherichia coli O157:H7, Klebsiella oxytoca, and Citrobacter freundii are pathogenic to humans.…”

“…Traditional MPN methods based on culturing require 24 to 7 h for enumeration. Rapid count plate method such as 3 M Petrifilm rapid count plate is widely accepted and approved for microbiological analysis in the food industry (Schraft and Watterworth 2005) and could provide a report within 24 h, but it is costly. In addition, all the culturing methods fail to detect sublethally injured bacteria that cannot grow on media.…”