Evaluation of two media and different plating techniques for enumeration of thermotolerant coliforms in river water.

Testing for evidence of faecal contamination in river water has been traditionally accomplished by enumeration of thermotolerant coliform bacteria. In this work, deoxycholate lactose and m-Endo Agar LES media were evaluated using different techniques. The colony count methods were pour plate technique on Deoxycholate Agar (DCL pour plate), spread plating on m-Endo Agar LES (ELS spread), and membrane filtration on m-Endo Agar LES (ELF filtration).

Evaluation of Petrifilm method for enumerating aerobic bacteria in Crottin goat cheese.

The Petrifilm Aerobic Count Plate (ACP) developed by 3M laboratories, is a ready-to-use culture medium system, useful for the enumeration of aerobic bacteria in food. Petrifilm was compared with a standard method in several different food products with satisfactory results. However, many studies showed that bacterial counts in Petrifilm were significantly lower than those obtained with conventional methods in fermented food.

Behavior of Yersinia enterocolitica and Salmonella typhimurium in Crottin goat's cheese.

In order to evaluate the behavior of Yersinia enterocolitica and Salmonella typhimurium in Crottin goat's cheese, inoculated products stored at 5, 15 and 25 degrees C were analysed together with chemical and microbiological characteristics of the cheese. In general, low counts of microorganisms were detected. None of the samples showed the presence of Escherichia coli, Salmonella spp.

Recovery of Escherichia coli in fresh water fish, Jenynsia multidentata and Bryconamericus iheringi.

Escherichia coli concentration was determined in digestive tract and muscle of Jenynsia multidentata and Bryconamericus iheringi through bioassays. Field experiments were also conducted with J. multidentata collected in the Suquía River, Córdoba, Argentina.

[Indicators of contamination and their relation to the presence of Escherichia coli in ready-to-eat foods].

The relationship between indicator microorganism counts and the presence of Escherichia coli was determined in ready-to-eat food in food stores. Aerobic counts (CA), total coliforms (CT) and molds and yeast (ML) were registered in each food sample as well as the presence of E. coli in food, surface and hand samples.