Escherichia coli O157[ratio ]H7 diarrhoea associated with well water and infected cattle on an Ontario farm

Abstract

A 16-month old female child living on an Ontario dairy farm was taken to hospital suffering from bloody diarrhoea. Escherichia coli O157:H7 was isolated from her stool. Initial tests of well water samples were negative for E. coli by standard methods but culture of selected coliform colonies on sorbitol-MacConkey agar led to isolation of E. coli O157:H7. E. coli O157:H7 was also isolated from 63% of cattle on the farm. The E. coli O157:H7 isolates from the child, the water and the cattle were phage type 14, produced verotoxins 1 and 2, and were highly related on analysis by pulsed field gel electrophoresis. The child did not have known direct contact with the cattle and did not consume unpasteurized milk. Hydrogeological investigation revealed the design and location of the well would allow manure-contaminated surface water to flow into the well. This investigation demonstrates that cattle farm well water is a potential source of E. coli O157:H7 which may not be identified by standard screening for E. coli in water.

From the Cover: Correlation of enterohemorrhagic Escherichia coli O157 prevalence in feces, hides, and carcasses of beef cattle during processing

“…Isolation methods and time of year are the likely reasons for the difference between the results of this study and those previously reported. In other EHEC O157 studies, immunomagnetic separation and enrichment broth selection played a key role in the isolation of the target organism (8,12,21). In the absence of a reliable ''gold standard'' for the presence of EHEC O157 in samples, it is difficult to directly compare the methods used in this study with other culture techniques (8,12,21,22).…”

“…In other EHEC O157 studies, immunomagnetic separation and enrichment broth selection played a key role in the isolation of the target organism (8,12,21). In the absence of a reliable ''gold standard'' for the presence of EHEC O157 in samples, it is difficult to directly compare the methods used in this study with other culture techniques (8,12,21,22). In addition, because operator experience can have a significant effect on the outcome obtained by different culture techniques, comparisons should be made on split samples in laboratories experienced in performing a given culture method.…”

“…However, it was noted in this study that 63 of 100 feedlots had at least one positive fecal sample, indicating widespread distribution of EHEC O157. Recent studies using improved enrichment and isolation procedures have indicated that the overall prevalence of EHEC O157 infection in cattle may be significantly higher than originally estimated (8,11,12). These studies found that peak EHEC O157 fecal shedding rates occur during summer and early fall, and they vary from a low of 0% to as high as 61% on some farms.…”

Água de consumo humano como fator de risco à saúde em propriedades rurais

“…No Reino Unido, após analisar-se amostras de água de fontes privadas, verificou-se que 100% das amostras dos poços e 63% das nascentes estavam fora dos padrões de potabilidade, representando um risco considerável a saúde dos consumidores (Fewtrell et al, 7 1998 mesma bactéria foi isolada nas fezes de 63% dos bovinos da fazenda (Jackson et al, 13 1998). 5 Baseado no exposto, o objetivo do presente artigo foi verificar o papel da água utilizada em propriedades rurais, como fator de risco à saúde dos consumidores.…”

Survival and retention ofEschenchia coliO157:H7 andCampylobacterin contrasting soils from the Toenepi catchment

“…Human epidemics have been traced to contamination of drinking water with E. coli O157:H7 from animal faeces (Swerdlow et al 1992;Jackson et al 1998;Licence et al 2001), and freshwater recreation has been linked to a risk of campylobacteriosis (Till et al 2008). As well, consumption of contaminated drinking water by animals can maintain infection levels in cattle herds (Faith et al 1996) and on dairy farms (Hanninen et al 1998).…”