Most probable number technique in Escherichia coli count using ISO 16649‐3, ISO 7251, and rapid test enumeration device (TEMPO EC) methods in milk and dairy products

Abstract

The aim of the study was to compare of International Standard Organization (ISO) 7251, ISO 16649‐3 most probable number (MPN) assay for the enumeration of Escherichia coli group to the Tempo EC automated method using a variety of spiked milk and milk product foods. Foods evaluated in this study included wet pasta (crema), milk, ayran, and ice cream. The spiked food samples were diluted at three inoculation levels such as low, medium, and high. A comparison of the results indicated that automated system approximated the inoculation level to an automated system. In this study, TEMPO EC, ISO 16649‐3, and ISO 7251 methods are compliant for MPN E. coli count in high, medium, and low contamination level studies. Nevertheless, for precise results, performing primary validation studies by ISO, Association Française de Normalisation (AFNOR), and/or Association Of Official Analytical Chemists (AOAC) will give more reliable results. Practical applications In Turkish Food Codex Microbiological Criteria Communique, it is requested to perform studies of E. coli analysis method in milk and milk products as per ISO 16649‐3. However, in the revised version of ISO 16649‐3, it is stated in the scope of the standard that this method does not provide a full assessment for all products particularly for milk and milk products and that ISO 7251 method should be used in these samples. As it is required in new methods, it has been intended to perform comparative analyses to low, medium, and high inoculation level with rapid the TEMPO EC card and conventional test methods by ISO, AFNOR, and/or AOAC. If the use of TEMPO EC, laboratory response time will improve with automation reducing the time for enumeration of E. coli from 4 days to 24 hr, especially critical for evaluation of perishable foods and outbreak events.

Production of Low‐fat mayonnaise without preservatives: Using the ultrasonic process and investigating of microbial and physicochemical properties of the resultant product

“…The bags were homogenized for 2 min at 8,000 rpm (SH-IIM, Anke Biotechnology Co., Shanghai, China). A series of 10 times dilutions in Ringer solution was made and cultured using pure plate method with Plate Count Agar medium (Merck, Darmstadt, Germany), then incubated at 37°C for 72 hr for total number of colonies count (ISO4833-1, 2013), incubated at 25°C for 120 hr in dicholoran (18%)-glycerol (DG18) culture medium (Merck, Darmstadt, Germany) for molds and yeasts (ISO, 21527-2, 2008), at 30°C for 120 hr in Orange Serum Agar culture medium (Merck, Darmstadt, Germany) for acid-tolerant micro-organisms at 30°C for 72 hr in Lactobacillus MRS Broth culture (Merck, Darmstadt, Germany) for heterofermentative lactic acid bacteria (ISIRI, 2017) and for Escherichia Coli 10 ml of diluted samples were put into double concentration of Lauryl Sulfate Broth culture (Merck, Darmstadt, Germany) and incubated at 37°C for 24-48 hr (Yörük, 2018).…”

Physicochemical and Microbiological Characteristics from “Wagashi” Production Whey in Abomey-Calavi (Benin)

“…The enumeration of Escherichia coli was demonstrated by the Tryptone Bile X-Glucuronide (TBX) culture medium according to the ISO standard [14]. A quantity (0.1 ml) of the stock suspension or of the dilutions considered was added and spread over 15 to 20 ml of the TBX culture medium previously prepared in sterile petri dishes.…”

Evaluation of the Tempo® System: Improving the Microbiological Quality Monitoring of Human Milk

“…This methodology precludes a rapid intervention upon the human milk processing chain and can result in time, material and product wastage. New bacteriological testing technologies with higher throughput have been recently introduced, among others, by the food and cosmetic industries as a means of intervening faster on their production chain [26,27]. The TEMPO ® system (bioMérieux, Marcy-l'Étoile, France) is the first semi-automated bacteriological testing technology able to identify contaminants typically found in human milk.…”