scholarly journals Translocated Intimin Receptors (Tir) of Shiga-Toxigenic Escherichia coli Isolates Belonging to Serogroups O26, O111, and O157 React with Sera from Patients with Hemolytic-Uremic Syndrome and Exhibit Marked Sequence Heterogeneity

1998 ◽  
Vol 66 (11) ◽  
pp. 5580-5586 ◽  
Author(s):  
Adrienne W. Paton ◽  
Paul A. Manning ◽  
Matthew C. Woodrow ◽  
James C. Paton
Keyword(s):  
Escherichia Coli ◽  
Hemolytic Uremic Syndrome ◽  
Amino Acid Sequences ◽  
Receptor Protein ◽  
Receptor Interaction ◽  
Host Cell Membrane ◽  
Western Blots ◽  
Sequence Heterogeneity ◽  
E Coli ◽  
Uremic Syndrome

ABSTRACT The capacity to form attaching and effacing (A/E) lesions on the surfaces of enterocytes is an important virulence trait of several enteric pathogens, including enteropathogenic Escherichia coli (EPEC) and Shiga-toxigenic E. coli (STEC). Formation of such lesions depends upon an interaction between a bacterial outer membrane protein (intimin) and a bacterially encoded receptor protein (Tir) which is exported from the bacterium and translocated into the host cell membrane. Intimin, Tir, and several other proteins necessary for generation of A/E lesions are encoded on a chromosomal pathogenicity island termed the locus for enterocyte effacement (LEE). Reports of sequence heterogeneity and antigenic variation in the region of intimin believed to be responsible for receptor binding raise the possibility that the receptor itself is also heterogeneous. We have examined this by cloning and sequencingtir genes from three different STEC strains belonging to serogroups O26, O111, and O157. The deduced amino acid sequences for the Tir homologues from these strains varied markedly, exhibiting only 65.4, 80.2, and 56.7% identity, respectively, to that recently reported for EPEC Tir. STEC Tir is also highly immunogenic in humans. Western blots of E. coli DH5α expressing the various STECtir genes cloned in pBluescript [but not E. coli DH5α(pBluescript)] reacted strongly with convalescent sera from patients with hemolytic-uremic syndrome (HUS) caused by known LEE-positive STEC. Moreover, no reaction was seen when the various clone lysates were probed with serum from a patient with HUS caused by a LEE-negative STEC or with serum from a healthy individual. Covariation of exposed epitopes on both intimin and Tir may be a means whereby STEC avoid host immune responses without compromising adhesin-receptor interaction.

Outbreak of Shiga Toxin–Producing Escherichia coli (STEC) O104:H4 Infection in Germany Causes a Paradigm Shift with Regard to Human Pathogenicity of STEC Strains

2012 ◽  
Vol 75 (2) ◽  
pp. 408-418 ◽  
Author(s):  
LOTHAR BEUTIN ◽  
ANNETT MARTIN
Keyword(s):  
Escherichia Coli ◽  
Hemolytic Uremic Syndrome ◽  
Shiga Toxin ◽  
Outbreak Strain ◽  
Fenugreek Seeds ◽  
E Coli ◽  
Aggregative Adherence ◽  
Uremic Syndrome ◽  
Enterocyte Effacement ◽  
The Way

An outbreak that comprised 3,842 cases of human infections with enteroaggregative hemorrhagic Escherichia coli (EAHEC) O104:H4 occurred in Germany in May 2011. The high proportion of adults affected in this outbreak and the unusually high number of patients that developed hemolytic uremic syndrome makes this outbreak the most dramatic since enterohemorrhagic E. coli (EHEC) strains were first identified as agents of human disease. The characteristics of the outbreak strain, the way it spread among humans, and the clinical signs resulting from EAHEC infections have changed the way Shiga toxin–producing E. coli strains are regarded as human pathogens in general. EAHEC O104:H4 is an emerging E. coli pathotype that is endemic in Central Africa and has spread to Europe and Asia. EAHEC strains have evolved from enteroaggregative E. coli by uptake of a Shiga toxin 2a (Stx2a)–encoding bacteriophage. Except for Stx2a, no other EHEC-specific virulence markers including the locus of enterocyte effacement are present in EAHEC strains. EAHEC O104:H4 colonizes humans through aggregative adherence fimbrial pili encoded by the enteroaggregative E. coli plasmid. The aggregative adherence fimbrial colonization mechanism substitutes for the locus of enterocyte effacement functions for bacterial adherence and delivery of Stx2a into the human intestine, resulting clinically in hemolytic uremic syndrome. Humans are the only known natural reservoir known for EAHEC. In contrast, Shiga toxin–producing E. coli and EHEC are associated with animals as natural hosts. Contaminated sprouted fenugreek seeds were suspected as the primary vehicle of transmission of the EAHEC O104:H4 outbreak strain in Germany. During the outbreak, secondary transmission (human to human and human to food) was important. Epidemiological investigations revealed fenugreek seeds as the source of entry of EAHEC O104:H4 into the food chain; however, microbiological analysis of seeds for this pathogen produced negative results. The survival of EAHEC in seeds and the frequency of human carriers of EAHEC should be investigated for a better understanding of EAHEC transmission routes.

Verocytotoxin-Producing Escherichia coli O26 in Raw Water Buffalo (Bubalus bubalis) Milk Products in Italy

2009 ◽  
Vol 72 (8) ◽  
pp. 1705-1708 ◽  
Author(s):  
VANESSA LORUSSO ◽  
ANGELA DAMBROSIO ◽  
NICOLETTA CRISTIANA QUAGLIA ◽  
ANTONIO PARISI ◽  
GIOVANNA LA SALANDRA ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hemolytic Uremic Syndrome ◽  
Dairy Products ◽  
Water Buffalo ◽  
Bubalus Bubalis ◽  
Buffalo Milk ◽  
Raw Water ◽  
E Coli ◽  
Isolation And Characterization ◽  
Uremic Syndrome

Escherichia coli O26 is known as a verocytotoxin-producing E. coli (VTEC) organism that causes severe foodborne diseases such as hemorrhagic colitis and hemolytic uremic syndrome. Although cattle are the most important reservoir of VTEC, only a few reports on the role of water buffalo (Bubalus bubalis) as a reservoir of VTEC and on the presence of these organisms in their milk are available. However, in Southern Italy, where water buffalo are intensively reared, an outbreak of hemolytic uremic syndrome due to E. coli O26 has recently been reported, in which the consumption of typical dairy products was considered to be a common risk factor. The aims of this work were to assess the prevalence of E. coli O26 in raw water buffalo milk, to characterize the virulence gene profiles of the isolates, and to evaluate their phenotypic antimicrobial resistance pattern. Of 160 analyzed samples, 1 (0.6%) tested positive for E. coli O26, and the isolate showed the stx1+/stx2+/eae−/hlyA+ genotypic profile. The strain showed resistance against glycopeptides, macrolides, and penicillins. The presence of VTEC organisms in raw water buffalo milk could be considered to be a potential threat to consumers; however, the strict adherence to the processes used in the preparation of the most common buffalo dairy products could strongly mitigate the foodborne risk. To our knowledge, this article reports the first isolation and characterization of E. coli O26 VTEC in raw water buffalo milk.

Escherichia coli O157:H7 as the Predominant Pathogen Associated With the Hemolytic Uremic Syndrome: A Prospective Study in the Pacific Northwest

PEDIATRICS ◽  
1987 ◽  
Vol 80 (1) ◽  
pp. 37-40
Author(s):  
Marguerite A. Neill ◽  
Phillip I. Tarr ◽  
Carla R. Clausen ◽  
Dennis L. Christie ◽  
Robert O. Hickman
Keyword(s):  
Escherichia Coli ◽  
Prospective Study ◽  
Hemolytic Uremic Syndrome ◽  
Pacific Northwest ◽  
Enteric Pathogens ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
The Pacific ◽  
Uremic Syndrome ◽  
A Prospective Study

During a 12-month period, 14 patients with the hemolytic uremic syndrome were identified in a prospective study of enteric pathogens associated with this disorder. Of the 12 patients with a diarrheal illness preceding the onset of hemolytic uremic syndrome, fecal Escherichia coli O157:H7 was detected in seven (58%), all of whom had bloody diarrhea. Half of the siblings of these patients had concurrent nonbloody diarrhea. No source for infection with this organism was identified. Enteric infection with E coli O157:H7 occurs in the majority of cases of hemolytic uremic syndrome following diarrheal illness in the Pacific Northwest and may represent a previously overlooked cause of hemolytic uremic syndrome in other locales. Evaluation of all cases of hemolytic uremic syndrome for enteric pathogens should routinely include cultures for E coli O157:H7 until results of additional studies clarify the distribution of agents associated with hemolytic uremic syndrome in different geographic regions. These findings may provide new opportunities for the design of therapeutic and preventive strategies in this disorder.

scholarly journals The Isolation Rate ofEscherichia coli0157:H7 in Toronto and Surrounding Communities

1990 ◽  
Vol 1 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Andrew E Simor ◽  
Christine Watt ◽  
Donald E Low
Keyword(s):  
Escherichia Coli ◽  
Hemolytic Uremic Syndrome ◽  
Diarrheal Disease ◽  
Hemorrhagic Colitis ◽  
Isolation Rate ◽  
E Coli ◽  
History Of ◽  
Uremic Syndrome ◽  
Stool Specimens ◽  
Differential Medium

Verocytotoxin-producing strains ofEscherichia coli,most often serotype 0157:H7, have been associated with both sporadic and epidemic diarrheal disease in Canada. In order to determine the isolation rate ofE coli0157:H7 in outpatients with diarrhea, all stool specimens submitted for culture to Med-Chem Laboratories in Metropolitan Toronto between June 1988 and September 1989 were cultured on MacConkey-Sorbitol agar in addition to standard enteric media. A total of 46 (0.3%) of 16,125 stool specimens yieldedE coli0157:H7 or verotoxin-producingE coli0157:H−. These isolates came from 31 patients with diarrhea; only 16 (52%) had a history of hemorrhagic colitis and one patient developed hemolytic uremic syndrome. Although MacConkey-Sorbitol agar was useful as a differential medium for detectingE coli0157:H7, 14.5% of all specimens yielded nonsorbitol-fermenting isolates. It is not certain whether the routine use of MacConkey-Sorbitol agar is justified when isolation rates ofE coli0157:117 are very low.

scholarly journals Whole-Genome Sequencing Analysis of a stx-Negative Escherichia coli O63:H6 Isolate Associated with Hemolytic Uremic Syndrome

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1823
Author(s):  
Tae Yeul Kim ◽  
Tae-Min La ◽  
Taesoo Kim ◽  
Sun Ae Yun ◽  
Sang-Won Lee ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hemolytic Uremic Syndrome ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Virulence Gene ◽  
Enterohemorrhagic Escherichia Coli ◽  
Whole Genome ◽  
Sequencing Analysis ◽  
E Coli ◽  
Uremic Syndrome

Shiga toxin-encoding genes (stx) of enterohemorrhagic Escherichia coli (EHEC) can be lost during infection or in vitro cultivation, and in clinical practice, it is difficult to distinguish EHEC that have lost stx (EHEC-LST) from enteropathogenic E. coli (EPEC), as both are stx-negative and eae-positive. In this study, we performed whole-genome sequencing (WGS) of a stx-negative, eae-positive E. coli O63:H6 isolate from a child with hemolytic uremic syndrome and compared its genome with those of nine E. coli O63:H6 strains in public databases. Virulence gene profiles were analyzed and core-genome multilocus sequence typing (cgMLST) was conducted. The virulence gene profile of our isolate was consistent with EHEC, except for the absence of stx, and the isolate clustered with seven EHEC strains but was distant from two EPEC strains in cgMLST. In genome alignment, our isolate exhibited a high nucleotide identity with EHEC strain 377323_2f but displayed a gap corresponding to the stx-harboring prophage sequence. Overall, our isolate was genetically closely related to EHEC strains, consistent with this being an EHEC-LST strain. As EHEC-LST may be misdiagnosed as EPEC in routine laboratories, comparative genomic analysis using WGS can be useful to determine whether stx-negative and eae-positive isolates are EHEC-LST or EPEC.

scholarly journals Escherichia coli O157:H7 and O157:H−Strains That Do Not Produce Shiga Toxin: Phenotypic and Genetic Characterization of Isolates Associated with Diarrhea and Hemolytic-Uremic Syndrome

1999 ◽  
Vol 37 (11) ◽  
pp. 3491-3496 ◽  
Author(s):  
H. Schmidt ◽  
J. Scheef ◽  
H. I. Huppertz ◽  
M. Frosch ◽  
H. Karch
Keyword(s):  
Escherichia Coli ◽  
Hemolytic Uremic Syndrome ◽  
Shiga Toxin ◽  
Low Frequency ◽  
Diagnostic Methods ◽  
Gene Encoding ◽  
E Coli ◽  
Uremic Syndrome ◽  
Plasmid Genes ◽  
Phenotypic And Genetic Characterization

We have isolated one sorbitol-nonfermenting (SNF) Escherichia coli O157:H7 isolate and five sorbitol-fermenting (SF) E. coli O157:H− isolates that do not contain Shiga toxin (Stx) genes (stx). Isolates originated from patients with diarrhea (n = 4) and hemolytic-uremic syndrome (HUS) (n = 2). All isolates harbored a chromosomaleae gene encoding gamma-intimin as well as the plasmid genes E-hly and etp. The E. coliO157:H7 isolate was katP and espP positive. Respective sera obtained from the patient with HUS contained antibodies to the O157 lipopolysaccharide antigen. Thestx-negative E. coli O157:H7 isolate is genetically related to stx-positive SNF E. coliO157:H7. All stx-negative SF E. coliO157:H− isolates belong to the same genetic cluster and are closely related to stx-positive SF E. coliO157:H− isolates. Our data indicate thatstx-negative E. coli O157:H7/H−variants may occur at a low frequency and cannot be recognized by diagnostic methods that target Stx.

scholarly journals Structure and Function of Plasmid pColD157 of Enterohemorrhagic Escherichia coli O157 and Its Distribution among Strains from Patients with Diarrhea and Hemolytic-Uremic Syndrome

1998 ◽  
Vol 36 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Clemens Hofinger ◽  
Helge Karch ◽  
Herbert Schmidt
Keyword(s):  
Escherichia Coli ◽  
Nucleotide Sequence ◽  
Hemolytic Uremic Syndrome ◽  
Enterohemorrhagic Escherichia Coli ◽  
E Coli ◽  
Uremic Syndrome ◽  
And Function ◽  
High Degree ◽  
Degree Of Similarity

In this study, pColD157, a 6.7-kb colicinogenic plasmid of enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain CL40cu, was characterized by restriction mapping and determination of its complete nucleotide sequence. The sequence consists of 6,675 bp and shows a high degree of similarity to the nucleotide sequence of colicinogenic plasmids pColD-CA23 and pColK. Seven potential genes were located on pColD157, three of which were closely related (>97.9%) to the colicin D structural gene and the corresponding immunity and lysis genes of plasmid pColD-CA23, and these were therefore designatedcda, cdi, and cdl, respectively, using the reference extension -CL40 for differentiation. The adjacent 3′ region is related to the origin of replication of pColD-CA23. In contrast, the remaining part of the plasmid harbors a cluster of genes, closely related to the mobilization genes of pColK, which is followed by a 0.3-kb stretch homologous to the pColK resolution function. These determinants were designated mbdA, mbdB,mbdC, and mbdD and cdr, respectively. Southern blot analysis was performed with a probe specific for the cda gene of pColD157 and two groups of EHEC O157:H7 isolates from patients with diarrhea or hemolytic-uremic syndrome resident in Germany. Whereas 16 of 46 E. coli O157 strains isolated between 1987 and 1991 harbored plasmid pColD157, only 1 of 50 strains isolated during 1996 carried this plasmid. In addition, all strains harboring plasmid pColD157 were shown to have colicinogenic activity.

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