Invited Review: Prevalence of Shiga Toxin-Producing Escherichia coli in Dairy Cattle and Their Products

Abstract

The main objective of this review was to assess the role of dairy cattle and their products in human infections with Shiga toxin-producing Escherichia coli (STEC). A large number of STEC strains (e.g., members of the serogroups O26, O91, O103, O111, O118, O145, and O166) have caused major outbreaks and sporadic cases of human illnesses that have ranged from mild diarrhea to the life-threatening hemolytic uremic syndrome. These illnesses were traced to O157 and non-O157 STEC. In most cases, STEC infection was attributed to consumption of ground beef or dairy products that were contaminated with cattle feces. Thus, dairy cattle are considered reservoirs of STEC and can impose a significant health risk to humans. The global nature of food supply suggests that safety concerns with beef and dairy foods will continue and the challenges facing the dairy industry will increase at the production and processing levels. In this review, published reports on STEC in dairy cattle and their products were evaluated to achieve the following specific objectives: 1) to assemble a database on human infections with STEC from dairy cattle, 2) to assess prevalence of STEC in dairy cattle, and 3) to determine the health risks associated with STEC strains from dairy cattle. The latter objective is critically important, as many dairy STEC isolates are known to be of high virulence. Fecal testing of dairy cattle worldwide showed wide ranges of prevalence rates for O157 (0.2 to 48.8%) and non-O157 STEC (0.4 to 74.0%). Of the 193 STEC serotypes of dairy cattle origin, 24 have been isolated from patients with hemolytic uremic syndrome. Such risks emphasize the importance and the need to develop long-term strategies to assure safety of foods from dairy cattle.

Molecular based prevalence of shigatoxigenic Escherichia coli in rectal swab of apparently healthy cattle in Mymensingh district, Bangladesh

“…The prevalence of O157 E. coli as revealed in this study is inclined with the previous report of Hussein and Sakuma (2005).…”

Tüketime Sunulan Kıymalarda Escherichia coli O157:H7’nin ve Bazı Virülens Genlerinin Araştırılması

“…This proportion is in parallel with previous studies except the researchers conducted in South Africa. The differences between the results may be due to cultivation method, sample size and resource, geographical region, season and degree of dispersion of E. coli O157: H7 infections in the region [14] .…”

Elazığ’da Mezbahalarda Kesilen Sığırlardan ve Piyasada Satılan Kıymalardan Shiga Toksin Üreten Escherichia coli O157’nin İzolasyonu, Virulens Genleri ve Antibiyotiklere Duyarlılıkları

“…However, samples were collected in winter and spring months. It was reported that in ruminants the prevalence of Escherichia coli O157:H7 is the highest in summer months and decreases in winter months 6,26 . Pathogenic STEC strains produce toxins that cause human illnesses and can produce other virulence factors that may increase the severity of illnesses.…”