Risk Factors of Sporadic Human Infection of Shiga Toxin Producing Escherichia coli O157 and Non-O157 in Australia

There is very little human disease associated with enterohaemorrhagic Escherichia coli O157 in Australia even though these organisms are present in the animal population. A group of Australian isolates of E. coli O157:H7 and O157:H- from human and animal sources were tested for the presence of virulence markers and compared by XbaI DNA macrorestriction analysis using pulsed-field gel electrophoresis (PFGE). Each of 102 isolates tested contained the gene eae which encodes the E. coli attaching and effacing factor and all but one carried the enterohaemolysin gene, ehxA, found on the EHEC plasmid. The most common Shiga toxin gene carried was stx2c, either alone (16%) or in combination with stx1 (74%) or stx2 (3%). PFGE grouped the isolates based on H serotype and some clusters were source specific. Australian E. coli O157:H7 and H- isolates from human, animal and meat sources carry all the virulence markers associated with EHEC disease in humans therefore other factors must be responsible for the low rates of human infection in Australia.

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Risk factors for sporadic Shiga toxin-producing Escherichia coli O157 infections in FoodNet sites, 1999–2000

Epidemiology and Infection ◽

10.1017/s0950268806007564 ◽

2006 ◽

Vol 135 (6) ◽

pp. 993-1000 ◽

Cited By ~ 46

Author(s):

A. C. VOETSCH ◽

M. H. KENNEDY ◽

W. E. KEENE ◽

K. E. SMITH ◽

T. RABATSKY-EHR ◽

...

Keyword(s):

Risk Factors ◽

Escherichia Coli ◽

Shiga Toxin ◽

Case Control Study ◽

Escherichia Coli O157 ◽

Indirect Contact ◽

Illness Onset ◽

Laboratory Surveillance ◽

Clinical Illness ◽

Control Study

SUMMARYTo monitor risk factors for illness, we conducted a case-control study of sporadic Shiga toxin-producing Escherichia coli O157 (STEC O157) infections in 1999–2000. Laboratory-confirmed cases of STEC O157 infection were identified through active laboratory surveillance in all or part of seven states. Patients and age-matched controls were interviewed by telephone using a standard questionnaire. Information was collected on demographics, clinical illness, and exposures to food, water, and animals in the 7 days before the patient's illness onset. During the 12-month study, 283 patients and 534 controls were enrolled. STEC O157 infection was associated with eating pink hamburgers, drinking untreated surface water, and contact with cattle. Eating produce was inversely associated with infection. Direct or indirect contact with cattle waste continues to be a leading identified source of sporadic STEC O157 infections.

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Pathogenic Potential of Emergent Sorbitol-Fermenting Escherichia coli O157:NM

Infection and Immunity ◽

10.1128/iai.01180-08 ◽

2008 ◽

Vol 76 (12) ◽

pp. 5598-5607 ◽

Cited By ~ 39

Author(s):

Tracy Rosser ◽

Tracy Dransfield ◽

Lesley Allison ◽

Mary Hanson ◽

Nicola Holden ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Human Infection ◽

Escherichia Coli O157 ◽

Pathogenic Potential ◽

E Coli ◽

Toxin Exposure ◽

Uremic Syndrome ◽

Human Infections ◽

Main Factor

ABSTRACT Non-sorbitol-fermenting (NSF) Escherichia coli O157:H7 is the primary Shiga toxin-producing E. coli (STEC) serotype associated with human infection. Since 1988, sorbitol-fermenting (SF) STEC O157:NM strains have emerged and have been associated with a higher incidence of progression to hemolytic-uremic syndrome (HUS) than NSF STEC O157:H7. This study investigated bacterial factors that may account for the increased pathogenic potential of SF STEC O157:NM. While no evidence of toxin or toxin expression differences between the two O157 groups was found, the SF STEC O157:NM strains adhered at significantly higher levels to a human colonic cell line. Under the conditions tested, curli were shown to be the main factor responsible for the increased adherence to Caco-2 cells. Notably, 52 of 66 (79%) European SF STEC O157:NM strains tested bound Congo red at 37οC and this correlated with curli expression. In a subset of strains, curli expression was due to increased expression from the csgBAC promoter that was not always a consequence of increased csgD expression. The capacity of SF STEC O157:NM strains to express curli at 37οC may have relevance to the epidemiology of human infections as curliated strains could promote higher levels of colonization and inflammation in the human intestine. In turn, this could lead to increased toxin exposure and an increased likelihood of progression to HUS.

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Influence of socio-economic status on Shiga toxin-producing Escherichia coli (STEC) infection incidence, risk factors and clinical features

Epidemiology and Infection ◽

10.1017/s0950268819000864 ◽

2019 ◽

Vol 147 ◽

Author(s):

N. L. Adams ◽

L. Byrne ◽

T. C. Rose ◽

G. K. Adak ◽

C. Jenkins ◽

...

Keyword(s):

Risk Factors ◽

Escherichia Coli ◽

Shiga Toxin ◽

Economic Status ◽

Care Seeking ◽

Socio Economic Status ◽

Accident And Emergency ◽

Incidence Risk ◽

Potential Risk Factors

Abstract Shiga toxin-producing Escherichia coli (STEC) infection can cause serious illness including haemolytic uraemic syndrome. The role of socio-economic status (SES) in differential clinical presentation and exposure to potential risk factors amongst STEC cases has not previously been reported in England. We conducted an observational study using a dataset of all STEC cases identified in England, 2010–2015. Odds ratios for clinical characteristics of cases and foodborne, waterborne and environmental risk factors were estimated using logistic regression, stratified by SES, adjusting for baseline demographic factors. Incidence was higher in the highest SES group compared to the lowest (RR 1.54, 95% CI 1.19–2.00). Odds of Accident and Emergency attendance (OR 1.35, 95% CI 1.10–1.75) and hospitalisation (OR 1.71, 95% CI 1.36–2.15) because of illness were higher in the most disadvantaged compared to the least, suggesting potential lower ascertainment of milder cases or delayed care-seeking behaviour in disadvantaged groups. Advantaged individuals were significantly more likely to report salad/fruit/vegetable/herb consumption (OR 1.59, 95% CI 1.16–2.17), non-UK or UK travel (OR 1.76, 95% CI 1.40–2.27; OR 1.85, 95% CI 1.35–2.56) and environmental exposures (walking in a paddock, OR 1.82, 95% CI 1.22–2.70; soil contact, OR 1.52, 95% CI 2.13–1.09) suggesting other unmeasured risks, such as person-to-person transmission, could be more important in the most disadvantaged group.

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