Escherichia coli O157 Prevalence in Different Cattle Farm Types and Identification of Potential Risk Factors

Abstract

Although the prevalence of Escherichia coli O157 on cattle farms has been examined extensively, the relationship between this pathogen and farm type has been established only rarely. A large-scale study was designed to determine the prevalence of E. coli O157 in the Flemish region of Belgium on farms of dairy cattle, beef cattle, mixed dairy and beef cattle, and veal calves. The effect of various factors on the occurrence at the pen level also was evaluated. In 2007, 180 farms were randomly selected based on region, farm size, and number of animals purchased and were examined using the overshoe sampling method. When possible, overshoes used in areas containing animals in three different age categories (< 8 months, 8 to 30 months, and > 30 months) were sampled on each farm. In total, 820 different pens were sampled and analyzed for the presence of E. coli O157 by enrichment, immunomagnetic separation, and plating on selective agar. Presumptive E. coli O157 colonies were identified using a multiplex PCR assay for the presence of the rfb(O157) and fliC(H7) genes. The statistical analysis was carried out with Stata SE/10.0 using a generalized linear regression model with a logit link function and a binomial error distribution. The overall farm prevalence of E. coli O157 was 37.8% (68 of 180 farms). The highest prevalence was found on dairy cattle farms (61.2%, 30 of 49 farms). The prevalences on beef, mixed dairy and beef, and veal calf farms were 22.7% (17 of 75 farms), 44.4% (20 of 45 farms), and 9.1% (1 of 11 farms), respectively. A significant positive correlation between age category and E. coli O157 prevalence was found only on mixed dairy and beef farms and dairy farms. No influence of farm size or introduction of new animals was demonstrated.

Prevalence of Carriage of Shiga Toxin-Producing Escherichia coli Serotypes O157:H7, O26:H11, O103:H2, O111:H8, and O145:H28 among Slaughtered Adult Cattle in France

“…These results are in agreement with the results of PCR screenings showing that the simultaneous presence of stx and eae genes was significantly more frequently detected in feces from young dairy bulls than in other categories. Overall, these results are consistent with the results of previous studies (54). Concerning the effect of age on STEC shedding, a Scotland investigation on 14,856 cattle fecal samples showed that an increased probability of a sampling group containing a STEC O157:H7-shedding animal was associated with larger numbers of 12-to 30-month-old finished cattle (55).…”

Escherichia coliO157:H7: Animal Reservoir and Sources of Human Infection

“…A recent study compared prevalence of EHEC O157:H7 among 180 farms of different types (dairy, beef, mixed, and veal) in Belgium and found higher farm prevalence in dairy farms (61%) than in beef farms (23%), with an intermediate prevalence in mixed farms (44%); pen prevalence was also higher at dairy farms (Cobbaut et al, 2009). Since this is the first comparative study of this kind, which rigorously applied the same sampling and culturing techniques to all surveyed farms, it is not yet possible to conclude what factors may be responsible for the noticed differences.…”

Detection of &lt;i&gt;Stx&lt;/i&gt;2 Gene of &lt;i&gt;Escherichia coli&lt;/i&gt; and Elevated Levels of Fecal Bacteria in the Cattle Farming Regions of Lake Oconee

“…It was unexpected that stx was not detected at the dairy farming sites because stx2 was detected in fecal samples from both dairy and beef cattle farms used in this study (data not shown), and previous research has indicated STEC is shed from beef and dairy cattle [7,27]. However, it has been suggested that depending on their diet beef cattle may shed greater quantities of STEC compared to dairy cattle [3]. Overall qPCR detected approximately 50% less E. coli at the dairy farm sites compared to the beef cattle sites, and IDEXX enumeration of E. coli also indicated that there were lower levels of E. coli at dairy cattle sites (DC1 and DC2).…”

“…This outbreak was caused by consumption of poorly cooked ground beef in a fast-food restaurant chain in the western US From 1982 to 2002, a total of 350 E. coli O157:H7 outbreaks were reported in 49 US states, from which 325 outbreaks included a number of deaths [1]. Although the Shiga-toxin gene is found in all enterohemorrhagic E. coli (STEC), serotype O157:H7 alone is responsible for more than 73,000 cases of disease per year in the US, and it has been implicated in 250 deaths [1,2]; Cattle and other ruminants are natural reservoirs of E. coli O157:H7 that can introduce pathogenic E. coli into the environment through fecal shedding [3][4][5][6]. Estimates of occurrence vary, but it appears that both dairy herds and beef feedlots can have animals carrying STEC including E. coli O157:H7 [6,7].…”