The effects of the addition of catalase (EC 1.11.1.6) or pyruvate on the enumeration of Staphylococcus aureus in Trypticase soy broth with 10% NaCl were examined using a most-probable-number technique. Addition of catalase or pyruvate to the broth increased enumeration of all heat-stressed S. aureus strains tested. Increases were also observed with nonstressed cells. Catalase and pyruvate were ...

This paper reports on the first successful molecular detection and quantification of soil protozoa. Quantification of heterotrophic flagellates and naked amoebae in soil has traditionally relied on dilution culturing techniques, followed by most-probable-number (MPN) calculations. Such methods are biased by differences in the culturability of soil protozoa and are unable to quantify specific ta...

A single-step most-probable-number method for enumerating fecal coliforms in sewage treatment plant effluents is described. The method requires the use of only one lactose-based medium and a single incubation temperature of 44.5 degrees C, and it can be completed in 18 h or less, as compared with up to 72 h for the standard most-probable-number method. The appearance of growth is the sole crite...

The incidence of confirmed test, false-positive coliform most-probable-number results was compared with environmental parameters and was found to be inversely related to water temperature. It is concluded that the completed coliform test must be done when water temperatures drop below 15 degrees C.

AIMS To better understand the transport and enumeration of dilute densities of Escherichia coli O157:H7 in agricultural watersheds, we developed a culture-based, five tube-multiple dilution most probable number (MPN) method. METHODS AND RESULTS The MPN method combined a filtration technique for large volumes of surface water with standard selective media, biochemical and immunological tests, ...