Invasion of Epithelial Cells by Locus of Enterocyte Effacement-Negative Enterohemorrhagic<i>Escherichia coli</i>

Luck, Shelley Narelle; Bennett-Wood, Vicki; Poon, Rachael; Robins-Browne, Roy M.; Hartland, Elizabeth L.

doi:10.1128/iai.73.5.3063-3071.2005

Cited by 48 publications

(53 citation statements)

References 60 publications

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“…Although the isolate does not invade endothelial cells, invasion is not a prerequisite for pathogenicity. Enterohemorrhagic Escherichia coli (EHEC) strains associated with severe disease, such as the LEE locus career strain O157:H7, attach to the epithelial cell surface and also do not invade 31) . The effect of our Enterobacter hormaechei isolate on vascular cell types will be the subject of further exploration.…”

Section: Persistence In Phagocytesmentioning

confidence: 99%

Cultivation of Enterobacter Hormaechei from Human Atherosclerotic Tissue

Rafferty

Dolgilevich

Kalachikov

et al. 2011

JAT

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Aim:To determine whether culturable bacterial strains are present in human atheromatous tissue and to investigate their properties using culture, quantitative PCR, metagenomic screening, genomic and biochemical methods. Methods: We analyzed femoral atherosclerotic plaque and five pairs of diseased and healthy arterial tissue for the presence of culturable bacteria using cell cultures and genomic analysis. Results: Gram negative aerobic bacilli were cultivated from the plaque tissue. Ribosomal 16S DNA amplification and sequencing identified the isolates as Enterobacter hormaechei. The isolate was resistant to ampicillin, cefazolin, and erythromycin. A circular 10kb plasmid was isolated from the strain. Antibiotic protection assays of the isolate demonstrated invasive ability in a human monocytic cell line. To extend the study, five matched pairs of diseased and healthy aortic tissue were analyzed via quantitative PCR. Eubacterial 16S rDNA was detected in all specimens, however, E. hormaechei DNA was detected in surprisingly high numbers in two of the diseased tissues only. Conclusions: While it is well documented that inflammation is an important risk factor for vascular pathophysiology, the association of bacteria with atherosclerosis has not been clearly established, in large part due to the inability to isolate live bacteria from atheromatous tissue. This is the first study providing direct evidence of Enterobacter spp. associated with atheromatous tissues. The data suggest that chronic infection with bacteria may be an under-reported etiologic factor in vascular pathogenesis. Importantly, characterization of the clinical isolate supports a model of atherogenesis where systemic dissemination of bacteria to atherosclerotic sites may occur via internalization in phagocytic cells. J Atheroscler Thromb, 2011; 18:72-81.

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Section: Persistence In Phagocytesmentioning

confidence: 99%

Cultivation of Enterobacter Hormaechei from Human Atherosclerotic Tissue

Rafferty

Dolgilevich

Kalachikov

et al. 2011

JAT

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“…Nevertheless, strains of EHEC that do not carry LEE are regularly isolated from patients with severe disease, and these isolates have been termed eae-or LEE-negative EHEC or STEC (2,4,11,13,17,20,24,25). We have shown previously that clinical isolates of LEE-negative EHEC have the ability to invade Chinese Hamster Ovary (CHO-K1) cells and the human colonic cell lines HCT-8 and Caco-2 (21). We speculate that this atypical subgroup of EHEC may use a mechanism of host cell invasion to colonize the intestinal mucosa.…”

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“…1A). To determine whether increased expression of FliC H21 correlated with increased invasion, we performed invasion assays with EH41 grown in LB broth overnight at 25°C and at 37°C as described previously (21,28). Briefly, washed semiconfluent cell monolayers were infected in the presence of 0.5% mannose with ca.…”

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confidence: 99%

“…Assays were carried out in duplicate, and the results represented data obtained from at least three independent experiments. Invasion was expressed as the percentage of total adherent bacteria that resisted killing by gentamicin (mean Ϯ the standard deviation), and adherence was expressed as the percentage of cell-associated bacteria from the original inoculum (mean Ϯ the standard deviation) as described previously (21,28). Differences in invasion and adherence were assessed for signifi-cance by using an unpaired, two-tailed t test.…”

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Contribution of FliC to Epithelial Cell Invasion by Enterohemorrhagic Escherichia coli O113:H21

et al. 2006

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Enterohemorrhagic Escherichia coli (EHEC) O113:H21 can invade epithelial cells. In this study, we found that invasion but not adherence was inhibited by anti-FliC H21 specific antibodies. In addition, deletion of fliC H21 from EHEC O113:H21 resulted in an eightfold decrease in invasion that was restored upon transcomplementation with fliC H21 but not with fliC H6 . These results suggested that FliC plays an important role in the pathogenesis of infections caused by EHEC O113:H21 by allowing bacteria to penetrate the intestinal epithelium.Shiga toxin-producing Escherichia coli (STEC) strains associated with hemorrhagic colitis or the hemolytic-uremic syndrome (HUS) in humans are commonly referred to as enterohemorrhagic E. coli (EHEC) (32). Most EHEC strains carry the locus for enterocyte effacement (LEE), which is essential for intestinal colonization (12,14,19,27,34). Nevertheless, strains of EHEC that do not carry LEE are regularly isolated from patients with severe disease, and these isolates have been termed eae-or LEE-negative EHEC or STEC (2,4,11,13,17,20,24,25). We have shown previously that clinical isolates of LEE-negative EHEC have the ability to invade Chinese Hamster Ovary (CHO-K1) cells and the human colonic cell lines HCT-8 and Caco-2 (21). We speculate that this atypical subgroup of EHEC may use a mechanism of host cell invasion to colonize the intestinal mucosa.Recently, Rogers et al. used the streptomycin-treated mouse model to show that LEE-negative EHEC O113:H21 strain 98NK2 was closely associated with the colonic mucosa during infection (30). In addition, bacteria were observed to penetrate the gut epithelium, and this close interaction was dependent on fliC. Although there was no difference in the fecal shedding of wild-type 98NK2 and a 98NK2⌬fliC mutant, fliC was required for full lethality in mice mediated by Shiga toxin, suggesting that a close interaction of 98NK2 with the intestinal mucosa was important for virulence. In the present study, we have extended these findings to examine the contribution of FliC to invasion of HCT-8 epithelial cells by EHEC O113:H21.FliC H21 -mediated invasion of HCT-8 cells. Previous work has shown that FliC is more highly expressed at temperatures below 37°C in the invasive pathogens Yersinia enterocolitica and Listeria monocytogenes (3, 9, 18). We therefore examined FliC H21 expression by wild-type STEC O113:H21 strain EH41 at two different growth temperatures. EH41 is a clinical isolate that has been described previously (10). Bacteria were grown in Luria-Bertani (LB) broth to the same optical density (i.e., an optical density at 600 nm of 0.8 [mid-log phase]) at 25 and 37°C, and whole-cell lysates were analyzed by immunoblotting with anti-H21 antibodies (Statens Serum Institut, Copenhagen, Denmark). The results showed that FliC H21 production by EH41 was more abundant at 25°C than at 37°C (Fig. 1A). To determine whether increased expression of FliC H21 correlated with increased invasion, we performed invasion assays with EH41 grown in LB broth overnight ...

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“…SubAB is more prevalent in LEE-negative than in LEE-positive strains of STEC and likely contributes to the progression to severe disease (15,16). In addition, LEE-negative STEC isolates from several serogroups, particularly STEC O113:H21, can invade tissue culture cells, a mechanism partially dependent on fl agellin (17)(18)(19).…”

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Shiga Toxin–producingEscherichia coliStrains Negative for Locus of Enterocyte Effacement

Newton¹,

Sloan²,

Bulach³

et al. 2009

Emerg. Infect. Dis.

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Most Shiga toxin-producing Escherichia coli (STEC) infections that are associated with severe sequelae such as hemolytic uremic syndrome (HUS) are caused by attaching and effacing pathogens that carry the locus of enterocyte effacement (LEE). However, a proportion of STEC isolates that do not carry LEE have been associated with HUS. To clarify the emergence of LEE-negative STEC, we compared the genetic composition of the virulence plasmids pO113 and pO157 from LEE-negative and LEE-positive STEC, respectively. The complete nucleotide sequence of pO113 showed that several plasmid genes were shared by STEC O157:H7. In addition, allelic profi ling of the ehxA gene demonstrated that pO113 belongs to a different evolutionary lineage than pO157 and that the virulence plasmids of LEEnegative STEC strains were highly related. In contrast, multilocus sequence typing of 17 LEE-negative STEC isolates showed several clonal groups, suggesting that pathogenic LEE-negative STEC has emerged several times throughout its evolution.

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Invasion of Epithelial Cells by Locus of Enterocyte Effacement-Negative EnterohemorrhagicEscherichia coli

Cited by 48 publications

References 60 publications

Cultivation of Enterobacter Hormaechei from Human Atherosclerotic Tissue

Cultivation of Enterobacter Hormaechei from Human Atherosclerotic Tissue

Contribution of FliC to Epithelial Cell Invasion by Enterohemorrhagic Escherichia coli O113:H21

Shiga Toxin–producingEscherichia coliStrains Negative for Locus of Enterocyte Effacement

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