, one of the 30 members of the bacterial family of Enterobacteriaceae
, is a coliform bacterium and is one of the 6 types of Escherichia
species (E. adecaroxylate, E. blattae, E. fergusonii, E. hermannii
and E. vulneris
). It is a gram-negative, non-spore-forming, facultative, anaerobic, rod shaped, mesophilic bacterium that grows in 7–45°C. The group of coliform bacteria consists of Citrobacter, Enterobacter, Klebsiella
. While there are bacteria of fecal origin among coliform bacteria, there are also bacteria of plant origin such as Enterobacter aerogenes, Citrobacter freundii
, and Klebsiella pneumoniae
Presence of coliform group in food is indicative of fecal contamination, poor hygienic conditions or existence of enteric pathogens. For instance, the presence of coliform bacteria in raw milk is an indication of poor hygiene in milking or storage conditions. The presence of coliform bacteria in raw or frozen fruits and vegetables is not important as Enterobacter, Citrobacterand Klebsiella are naturally present in the microbiota of plants. However, E. coli presence in fruits and vegetables is very important in terms of inadequate hygiene. E. coli is an important pathogen as it is an indicator of fecal contamination in foods and drinking water. Due to this characteristic, it is considered as an indicator bacterium in food safety and hygiene.
Shigatoxin producing E. coli (STEC) like E. coli O157:H7, E. coli O157:H- or E. coli O104:H4 are known to cause different diseases like diarrhea, hemorrhagic colitis (HC) and the potentially fatal hemolytic uremic syndrome (HUS). STEC are most commonly transmitted through undercooked minced meat, unpasteurized or inadequately pasteurized milk, cold sandwiches, sprouts and vegetables. As most of these foods have relatively short shelf lives, the need for a rapid, accurate and sensitive detection method is a major food safety issue.
The STEC Screening LyoKit detects stx1, stx2 and eae. The stx2f variant is included, which will not be detected using the ISO TS 13136 method.