Non-toxigenic Escherichia coli O157:H7 strain NCTC12900 causes attaching-effacing lesions and eae-dependent persistence in weaned sheep

Woodward, Martin J.; Best, Angus; Sprigings, K. A.; Pearson, G. R.; Skuse, A. M.; Wales, Andrew; Hayes, Christine; Roe, John M.; Low, J. C.; Ragione, Roberto M. La

doi:10.1078/1438-4221-00264

Cited by 50 publications

(56 citation statements)

References 38 publications

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“…15,40 Much less is known about O157:H7 colonization in sheep but the data suggests that it attaches more widely, including in the colon and rectum. [41][42][43] During our studies we found that half of the members of a single sheep flock carried the same new O157:H7-infecting phage, CEV2. Our data supports previous observations, by both us and others, that O157:H7-infecting phages are naturally present in the intestinal ecosystem of ruminants.…”

Section: Resultsmentioning

confidence: 70%

Naturally resident and exogenously applied T4-like and T5-like bacteriophages can reduceEscherichia coliO157

et al. 2011

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Section: Resultsmentioning

confidence: 70%

Naturally resident and exogenously applied T4-like and T5-like bacteriophages can reduceEscherichia coliO157

et al. 2011

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“…Robinson et al showed that the presence of stx 2 -converting phage increased adherence of EHEC to epithelial cells, suggesting a role of Stx2 in colonization (54). In contrast, Woodward et al demonstrated that an Stx-negative E. coli O157:H7 persists in weaned sheep, suggesting Shiga toxins are not important in colonization (67). Also, purified Stx1 can inhibit the activation and proliferation of certain bovine lymphocytes (18,43), which may facilitate colonization of E. coli O157:H7 at the bovine RAJ mucosa by modulation of mucosal immune responses.…”

Section: Discussionmentioning

confidence: 97%

“…Intimin and Tir, encoded on the LEE5 operon, are critical for intimate adherence and the formation of characteristic attaching and effacing lesions on cells in tissue culture by EHEC and enteropathogenic E. coli (12,13,32). Studies to determine the roles of intimin and Tir in animals have used newborn piglets, newborn colostrum-deprived calves, and sheep (6,8,10,11,14,33,40,60,63,65,67). Recent studies show that E. coli O157:H7 forms attaching and effacing lesions at the bovine RAJ and that the LEE4 operon is essential for colonization of E. coli O157:H7 in calves (48).…”

Section: Discussionmentioning

confidence: 99%

Role of Escherichia coli O157:H7 Virulence Factors in Colonization at the Bovine Terminal Rectal Mucosa

et al. 2006

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The human pathogen Escherichia coli O157:H7 causes hemorrhagic colitis and life-threatening sequelae and transiently colonizes healthy cattle at the terminal rectal mucosa. This study analyzed virulence factors important for the clinical manifestations of human E. coli O157:H7 infection for their contribution to the persistence of E. coli in cattle. The colonizing ability of E. coli O157:H7 was compared with those of nonpathogenic E. coli K-12 and isogenic deletion mutants missing Shiga toxin (Stx), the adhesin intimin, its receptor Tir, hemolysin, or the ϳ92-kb pO157. Fully ruminant steers received a single rectal application of one E. coli strain so that effects of mucosal attachment and survival at the terminal rectum could be measured without the impact of bacterial passage through the entire gastrointestinal tract. Colonization was monitored by sensitive recto-anal junction mucosal swab culture. Nonpathogenic E. coli K-12 did not colonize as well as E. coli O157:H7 at the bovine terminal rectal mucosa. The E. coli O157:H7 best able to persist had intimin, Tir, and the pO157. Strains missing even one of these factors were recovered in lower numbers and were cleared faster than the wild type. In contrast, E. coli O157:H7 strains that were missing Stx or hemolysin colonized like the wild type. For these three strains, the number of bacteria increased between days 1 and 4 postapplication and then decreased slowly. In contrast, the numbers of noncolonizing strains (K-12, ⌬tir, and ⌬eae) decreased from the day of application. These patterns consistently predicted long-term colonization or clearance of the bacteria from the bovine terminal rectal mucosa.Enterohemorrhagic Escherichia coli (EHEC) strains are a subset of Shiga toxin-producing E. coli (STEC) that can cause human disease and are threats to public health worldwide (46,49). Human illnesses caused by EHEC range from self-limiting watery diarrhea or hemorrhagic colitis to life-threatening sequelae, the hemolytic-uremic syndrome or thrombotic thrombocytopenic purpura. The predominant EHEC serotype associated with the most severe disease in North America, the United Kingdom, and Japan is O157:H7 (23,42,44,46,59).Cattle are considered the primary reservoir for E. coli O157:H7 and the most common source for food-borne and direct animal contact infections (5, 25, 69). Healthy cattle carry E. coli O157:H7 transiently without suffering pathological symptoms (2,4,26). Individual animals can passively shed E. coli O157:H7 in their feces for a short time (a few days) without establishing a colonized state or can pass fecal E. coli O157:H7 for a longer time (a month or more) if the bacteria colonize and persist (22). The conditions that lead to these different host-bacterium interactions are not understood.It is well accepted that reducing the carriage or prevalence of E. coli O157:H7 in cattle would reduce the risk of human exposure to this pathogen (61). Recently, the recto-anal junction (RAJ) mucosa was identified as the primary site of E. coli O157:H7 colonizatio...

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“…One of the LEE-encoded type III secreted proteins (Tir) is translocated into the host cell plasma membrane where it acts as a receptor for the LEEencoded outer-membrane protein intimin (DeVinney et al, 1999). Intimin is an important colonization factor for E. coli O157 : H7 in neonatal calves (Dean-Nystrom et al, 1998), lambs (Woodward et al, 2003), adult cattle and sheep (Cornick et al, 2002), gnotobiotic piglets (Donnenberg et al, 1993;McKee et al, 1995), rabbits (Ritchie et al, 2003) and streptomycin-treated mice (Judge et al, 2004). Intimin can also bind to b1-integrins (Frankel et al, 1996) and cell surface-localized nucleolin (Sinclair & O'Brien, 2002); however, the importance of such interactions in colonization of the ruminant intestines is unknown.…”

Section: Introductionmentioning

confidence: 99%

Identification of Escherichia coli O157 : H7 genes influencing colonization of the bovine gastrointestinal tract using signature-tagged mutagenesis

et al. 2004

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Enterohaemorrhagic Escherichia coli (EHEC) cause acute gastroenteritis in humans that may be complicated by life-threatening systemic sequelae. The predominant EHEC serotype affecting humans in the UK and North America is O157 : H7 and infections are frequently associated with contact with ruminant faeces. Strategies to reduce the carriage of EHEC in ruminants are expected to lower the incidence of human EHEC infections; however, the molecular mechanisms underlying persistence of EHEC in ruminants are poorly understood. This paper reports the first comprehensive survey for EHEC factors mediating colonization of the bovine intestines by using signature-tagged transposon mutagenesis. Seventy-nine E. coli O157 : H7 mutants impaired in their ability to colonize calves were isolated and 59 different genes required for intestinal colonization were identified by cloning and sequencing of the transposon insertion sites. Thirteen transposon insertions were clustered in the locus of enterocyte effacement (LEE), which encodes a type III protein secretion system required for the formation of attaching and effacing lesions on intestinal epithelia. A putative structural component of the apparatus (EscN) is essential for intestinal colonization; however, the type III secreted effector protein Map plays only a minor role. Other Type III secretion-associated genes were implicated in colonization of calves by E. coli O157 : H7, including z0990 (ecs0850), which encodes the non-LEE-encoded type III secreted effector NleD and the closely related z3023 (ecs2672) and z3026 (ecs2674) genes which encode homologues of Shigella IpaH proteins. We also identified a novel fimbrial locus required for intestinal colonization in calves by E. coli O157 : H7 (z2199-z2206; ecs2114-ecs2107/locus 8) and demonstrated that a mutant harbouring a deletion of the putative major fimbrial subunit gene is rapidly out-competed by the parent strain in co-infection studies. Our data provide valuable new information for the development of intervention strategies. INTRODUCTIONEnterohaemorrhagic Escherichia coli (EHEC) were first recognized as a cause of human disease in 1983 and are associated with diarrhoea and haemorrhagic colitis, which may be complicated by life-threatening renal and neurological sequelae, including haemolytic uraemic syndrome and thrombocytopaenic purpura (Karmali et al., 1983;Riley et al., 1983). EHEC, and in particular serotype O157 : H7, have since emerged as a major cause of severe diarrhoeal illness worldwide and EHEC infections are the leading antecedent to paediatric acute renal failure in many countries (Ammon, 1997; Mead et al., 1999; WHO, 1997). E. coli O157 : H7 strains are estimated to cause 73 480 cases and 60 deaths per annum in the United States, with serotypes other than O157 : H7 accounting for a further 36 740 illnesses (Mead et al., 1999). Non-O157 EHEC are an emerging problem, and indeed may be more prevalent than serogroup O157 in some countries (Bettelheim, 2000). EHEC are defined by their ability to produce one or mo...

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Non-toxigenic Escherichia coli O157:H7 strain NCTC12900 causes attaching-effacing lesions and eae-dependent persistence in weaned sheep

Cited by 50 publications

References 38 publications

Naturally resident and exogenously applied T4-like and T5-like bacteriophages can reduceEscherichia coliO157

Naturally resident and exogenously applied T4-like and T5-like bacteriophages can reduceEscherichia coliO157

Role of Escherichia coli O157:H7 Virulence Factors in Colonization at the Bovine Terminal Rectal Mucosa

Identification of Escherichia coli O157 : H7 genes influencing colonization of the bovine gastrointestinal tract using signature-tagged mutagenesis

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