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At least 19 recordsLinked to original sources
PubMed1990

Dermatitis in broilers caused by Escherichia coli: isolation of Escherichia coli from field cases, reproduction of the disease with Escherichia coli O78:K80 and conclusions under consideration of predisposing factors.

A dermatitis in broiler chickens, especially on the caudal back, thighs and around the cloaca is observed more frequently in the last years. The skin is swollen at sites of inflammation and a fibrineous plaque extends between muscle and subcutis. No clinical signs are visible in the living flock but the disease causes economical losses because of degrading and rejection of carcasses. Studies of literature and own field observations suggest that Escherichia (E.) coli is involved in the development of the dermatitis. The following serotypes were isolated from field cases: O78:K80 (3X), O2:K56 (2X), O127:K63 (3X), O9:K57 (1X), O140 (2X); two isolates could not be identified. The reproduction of the dermatitis was successful by infection via feather follicles with E. coli O78:K80. The density of broilers kept on farms may contribute to the outbreak of dermatitis by violation of the skin followed by infection of the injuries. Massage of the infected sites by close contact of birds and insufficient hygiene may support the development of the disease.

Animals↗
PubMed1998

Thermotolerance of Escherichia coli O157:H7 ATCC 43,894, Escherichia coli B, and an rpoS-deficient mutant of Escherichia coli O157:H7 ATCC 43,895 following exposure to 1.5% acetic acid.

On a beef carcass, Escherichia coli may sequentially encounter acid- and heat-intervention steps. This study tested whether acid stress (1.5% [vol/vol] acetic acid, pH 4.0, 37 degrees C, 15 min) would enhance subsequent heat resistance of E. coli. Initially, cells (E. coli O157:H7 ATCC 43894, nonpathogenic E. coli B [strain FRIK-124], and rpoS-deficient mutant 813-6 [derived from E. coli O157:H7 ATCC 43895]) were acid stressed and transferred to 54 degrees C trypticase soy broth (TSB), and survivors were immediately enumerated after at least three intervals of 12, 2, and 6 min, respectively, by plating. The ATCC 43894 and 813-6 strains survived the acid stress but strain FRIK-124 did not. Acid-stressed ATCC 43894 had significantly lower D values than the non-acid-stressed controls. Strain 813-6 had significantly lower D values than strain ATCC 43894, with no significant difference between acid-stressed and non-acid-stressed cells. In a second experiment, cooling of cells prior to plating resulted in an increased D value for acid-stressed ATCC 43894 cells, such that it was not significantly different from the D value for non-acid-stressed controls. Using this protocol, there was no significant difference in D values between acid-stressed and non-acid-stressed ATCC 43894 cells in prewarmed TSB (54, 58, and 62 degrees C), in prewarmed ground beef slurry (GBS; 58 degrees C), or in TSB and GBS inoculated at 5 degrees C and heated to 58 degrees C. The acid stress tested does not enhance subsequent heat resistance of E. coli.

Acetic Acid↗
PubMed1975

[Competence in Escherichia coli cells. III. Formation of competent states in Escherichia coli X7026 and Escherichia coli Hfr H cells during storage in different conditions].

The competence formation in 2 strains of Escherichia coli X7026 and Hfr H to isolated phage gamma DNA after the prolonged treatment of cells with Ca++ ions at low temperatures was investigated. In both strains studied the sensitivity of cells to phage lambda DNA increased during several days of maintenance at 4 degrees C in 0.2 M CaCl2, and reached the maximal value in 24-48 hours for E. coli Hfr H cells, and in 72-96 hours for E. coli X7026 cells. Cells maintained in CaCl2 for 24 hours and more interacted more effectively with DNA in the cold, and didn't need Ca++ ions at the last stage of transfection (incubation of the infectious mixture at 37 degrees C) as the freshly grown cells did. Variations induced in the cells after the prolonged action Ca++ ions were preserved only in the presence of CaCl2. After the washing of CaCl2 from the cells with 0.15 M NaCl they returned to the initial state. The competence formation in cells of E. coli X7026 under the effect of Ca++ ions was going on more actively when the cells were preliminary incubated for several days at 4 degrees C in the absence of CaCl2. E. coli Hfr H cells were resistant to this treatment.

Calcium↗
PubMed1996

[PCR methods for detection of enteropathogenic Escherichia coli (localized adherence) and enteroaggregative Escherichia coli].

A PCR method was developed to detect enteropathogenic Escherichia coli (localized adherence) and enteroaggregative Escherichia coli. A portion of the structural gene (bfpA) encoding bundle-forming pilus (BFP), was amplified by the PCR for the detection of enteropathogenic Escherichia coli. It proved to be sensitive and specific in detecting enteropathogenic Escherichia coli. For the detection of enteroaggregative Escherichia coli, a portion of aggR (a transcriptional activator of aggA coding a major fimbrial subunit) was amplified. Although few strains showing non-aggregative adherence gave positive result, the PCR method was shown to have greater sensitivity than the probe assay in detecting enteroaggregative Escherichia coli.

Bacterial Adhesion↗
PubMed2005

Evolutionary genetics of a new pathogenic Escherichia species: Escherichia albertii and related Shigella boydii strains.

A bacterium originally described as Hafnia alvei induces diarrhea in rabbits and causes epithelial damage similar to the attachment and effacement associated with enteropathogenic Escherichia coli. Subsequent studies identified similar H. alvei-like strains that are positive for an intimin gene (eae) probe and, based on DNA relatedness, are classified as a distinct Escherichia species, Escherichia albertii. We determined sequences for multiple housekeeping genes in five E. albertii strains and compared these sequences to those of strains representing the major groups of pathogenic E. coli and Shigella. A comparison of 2,484 codon positions in 14 genes revealed that E. albertii strains differ, on average, at approximately 7.4% of the nucleotide sites from pathogenic E. coli strains and at 15.7% from Salmonella enterica serotype Typhimurium. Interestingly, E. albertii strains were found to be closely related to strains of Shigella boydii serotype 13 (Shigella B13), a distant relative of E. coli representing a divergent lineage in the genus Escherichia. Analysis of homologues of intimin (eae) revealed that the central conserved domains are similar in E. albertii and Shigella B13 and distinct from those of eae variants found in pathogenic E. coli. Sequence analysis of the cytolethal distending toxin gene cluster (cdt) also disclosed three allelic groups corresponding to E. albertii, Shigella B13, and a nontypeable isolate serologically related to S. boydii serotype 7. Based on the synonymous substitution rate, the E. albertii-Shigella B13 lineage is estimated to have split from an E. coli-like ancestor approximately 28 million years ago and formed a distinct evolutionary branch of enteric pathogens that has radiated into groups with distinct virulence properties.

Adhesins, Bacterial↗
PubMed2004

Enzyme-linked immunosorbent assay for detection of Shiga toxin-producing Escherichia coli infection by antibodies to Escherichia coli secreted protein B in children with hemolytic uremic syndrome.

In order to detect immunoglobulin (Ig)A and IgG antibodies to Escherichia coli-secreted protein B in sera of children infected with Shiga toxin-producing Escherichia coli, an enzyme-linked immunosorbent assay was developed. The assay was tested using acute sera from 40 children with diarrhea-associated hemolytic uremic syndrome compared with 238 sera obtained from pediatric controls. Two cut-off values were used for children <5 (n=27) or > or =5 (n=13) years of age. Among the younger patients, 24 of 27 had IgA antibodies to Escherichia coli-secreted protein B (sensitivity, 89%; specificity, 98%) and 22 of 27 had IgG antibodies (sensitivity, 82%; specificity, 94%). Among the older patients, 13 of 13 had IgA antibodies (sensitivity, 100%; specificity, 96%) and 11 of 13 had IgG antibodies (sensitivity, 85%; specificity, 96%). This enzyme-linked immunosorbent assay detects Shiga-toxin-producing Escherichia coli independent of serogroup and could serve as a complementary assay for detection of infection.

Antibodies, Bacterial↗
PubMed1962

Isoleucine and valine metabolism in Escherichia coli. XI. Valine inhibition of the growth of Escherichia coli strain K-12.

Leavitt, Richard I. (Harvard Medical School, Boston, Mass.) and H. E. Umbarger. Isoleucine and valine metabolism in Escherichia coli. XI. Valine inhibition of the growth of Escherichia coli strain K-12. J. Bacteriol. 83:624-630. 1962.-The inhibition of the growth of Escherichia coli strain K-12 by valine was shown to be due to the sensitivity of the acetohydroxybutyrate-forming system to valine. It was demonstrated that both E. coli strain W, a strain whose growth is unaffected by valine, and a valine-resistant mutant of strain K-12 have acetolactate- and acetohydroxybutyrate-forming systems which are less sensitive to valine than that of strain K-12. It was further shown that alpha-aminobutyrate accumulates in the culture fluid of the valine-sensitive strain when incubated in the presence of valine. The levels of valine in the "free amino acid pool" were examined and found to be related to the differences in valine sensitivity of the acetolactate-forming systems of the three strains.

Amino Acids↗
PubMed1992

Serological cross-reactions between Escherichia coli O157 and other species of the genus Escherichia.

The antigenic relatedness of Escherichia coli O157 and four sorbitol-negative species of the genus Escherichia was examined. Isolates of Escherichia hermannii, E. fergusonii, E. vulneris, and E. blattae were tested in the tube agglutination assay by using polyclonal antisera and in the slide agglutination assay by using latex reagents. Only four isolates (17%) of E. hermannii exhibited serological cross-reactivity.

Cross Reactions↗
PubMed2003

Biochemical properties of a newly described Escherichia species, Escherichia albertii.

Five strains of a newly described Escherichia species, Escherichia albertii, were extensively characterized by conventional biochemical methods and by commercial identification panels. E. albertii is an indole-negative species that ferments D-mannitol but not D-xylose. Because these strains are not included in the databases of commercial systems at present, they were most often identified as Hafnia, Salmonella, Escherichia coli, or, on one system (MicroScan dried overnight panels), Yersinia ruckeri.

Bacterial Typing Techniques↗
PubMed1996

Detección de Escherichia coli toxigénica (LT) mediante la reacción en cadena de la polimerasa [The detection of toxigenic Escherichia coli (LT) by the polymerase chain reaction].

In this paper it is described the detection enteroxigenic Escherichia coli LT (+). This method is based on the amplification of a DNA fragment of 400 pairs of bases by polymerase chain reaction (PRC). The oligonucleotides were designed by the authors and the characteristic patterns were observed when the samples were submitted to an electrophoresis in an Agarose gel at 2%. The PCR had positive results with the strains of Escherichia coli 0:149 K; 88 (LT+) collection and with 20 strains isolated from patients with acute diarrhea. Negative results were found in Escherichia coli 0:101 K:99 NM (ST+), Vibrio cholerae 01 and Aeromonas hydrophila.

Aeromonas hydrophila↗
PubMed2004

Detection and isolation of Escherichia coli with a coding gene for enteroaggregative Escherichia coli heat-stable enterotoxin 1 from food and comparison with fecal isolates.

Enteroaggregative Escherichia coli heat-stable enterotoxin 1 (EAST1) was originally regarded as a putative enterotoxin of enteroaggregative Escherichia coli. Although its etiological role has not yet been elucidated, it has been epidemiologically suggested that some strains of E. coli possessing EAST1-coding gene (astA) but no other identifiable pathogenic properties comprise a new group of diarrhea-associated E. coli (EAST1EC). However, the source of the organisms and their prevalence in foods are still obscure. In this study, methods for detection of the organisms in foods heavily contaminated with coliforms were evaluated and properties of the isolated strains were compared with those of fecal strains. Four enrichment methods (brilliant green lactose bile broth, E. coli, lauryl tryptose broth, and a combination of brain heart infusion broth and tryptone phosphate broth) were evaluated through inspection of 115 samples. PCR showed positive results in 26 samples after enrichment with a combination of brain heart infusion broth and tryptone phosphate broth, and EAST1EC was successfully isolated from 18 samples. Fifteen samples showed a positive reaction in the PCR test after enrichment by the other methods, and the organisms were isolated from only 10 specimens. The highest prevalence of EAST1EC was found in animal products (16 of 54, 29.6%); the organism was rarely found in foods of plant origin (2 of 45, 4.4%) or fishery products (1 of 16, 6.3%). Although EAST1EC is unexpectedly common in animal products, its potential as a human pathogen remains uncertain because the possession of some virulence properties differs significantly between strains from fecal specimens and those from foods. Some food isolates, however, possess the same characteristics as diarrheal isolates do. It is necessary to clarify the pathogenicity of EAST1EC and the significance of food as a source of infection.

Animals↗
PubMed1993

Two open reading frames adjacent to the Escherichia coli K-12 transketolase (tkt) gene show high similarity to the mannitol phosphotransferase system enzymes from Escherichia coli and various gram-positive bacteria.

I have subcloned and sequenced the genes cmtB and cmtA of Escherichia coli K-12 which lie adjacent to the tkt gene on the chromosome. The genes cmtB and cmtA could encode a cytoplasmic protein (EIIA) and an integral-membrane protein (EIIBC), respectively, of the bacterial phospho enol pyruvate-dependent carbohydrate phosphotransferase system. High similarity to the Enzymes IIMtl of Escherichia coli K-12 (gene mtlA) and of Staphylococcus carnosus was detected, but the two genes did not complement mannitol-negative E. coli mutants without the use of a heterologous promoter.

Amino Acid Sequence↗
PubMed2003

Fishing new proteins in the twilight zone of genomes: the test case of outer membrane proteins in Escherichia coli K12, Escherichia coli O157:H7, and other Gram-negative bacteria.

We address the problem of clustering the whole protein content of genomes into three different categories-globular, all-alpha, and all-beta membrane proteins-with the aim of fishing new membrane proteins in the pool of nonannotated proteins (twilight zone). The focus is then mainly on outer membrane proteins. This is performed by using an integrated suite of programs (Hunter) specifically developed for predicting the occurrence of signal peptides in proteins of Gram-negative bacteria and the topography of all-alpha and all-beta membrane proteins. Hunter is tested on the well and partially annotated proteins (2160 and 760, respectively) of Escherichia coli K 12 scoring as high as 95.6% in the correct assignment of each chain to the category. Of the remaining 1253 nonannotated sequences, 1099 are predicted globular, 136 are all-alpha, and 18 are all-beta membrane proteins. In Escherichia coli 0157:H7 we filtered 1901 nonannotated proteins. Our analysis classifies 1564 globular chains, 327 inner membrane proteins, and 10 outer membrane proteins. With Hunter, new membrane proteins are added to the list of putative membrane proteins of Gram-negative bacteria. The content of outer membrane proteins per genome (nine are analyzed) ranges from 1.5% to 2.4%, and it is one order of magnitude lower than that of inner membrane proteins. The finding is particularly relevant when it is considered that this is the first large-scale analysis based on validated tools that can predict the content of outer membrane proteins in a genome and can allow cross-comparison of the same protein type between different species.

Bacterial Outer Membrane Proteins↗
PubMed2002

Colicins produced by the Escherichia fergusonii strains closely resemble colicins encoded by Escherichia coli.

Plasmid DNA of six Escherichia fergusonii colicinogenic strains (three producers of colicin E1, two of Ib and one of Ia) was isolated and the colicin-encoding regions of the corresponding Col plasmids were sequenced. Two new variants of colicin E1, one of colicin Ib, and one of colicin Ia were identified as well as new variants of the colicin E1 and colicin Ib immunity proteins and the colicin E1 lysis polypeptide. The recombinant Escherichia coli producer harboring pColE1 from E. fergusonii strain EF36 (pColE1-EF36) was found to be only partially immune to E1 colicins produced by two other E. fergusonii strains suggesting that pColE1-EF36 may represent an ancestor ColE1 plasmid.

Colicins↗
PubMed1998

Association of enterohemorrhagic Escherichia coli hemolysin with serotypes of shiga-like-toxin-producing Escherichia coli of human and bovine origins.

In this study we investigated whether the enterohemorrhagic Escherichia coli (EHEC) hemolysin gene ehxA could be used as an indicator of pathogenicity in Shiga-like-toxin-producing Escherichia coli (SLTEC) isolates. The isolates in a collection of 770 SLTEC strains of human and bovine origins were assigned to group 1 (230 human and 138 bovine SLTEC isolates belonging to serotypes frequently implicated in human disease), group 2 (85 human and 183 bovine isolates belonging to serotypes less frequently implicated in disease), and group 3 (134 bovine isolates belonging to serotypes not implicated in disease). PCR amplification was used to examine all of the SLTEC isolates for the presence of ehxA and the virulence-associated genes eae, slt-I, and slt-II. The percentages of human isolates in groups 1 and 2 that were positive for ehxA were 89 and 46%, respectively, and the percentages of bovine isolates in groups 1 to 3 that were positive for ehxA were 89, 51, and 52%, respectively. The percentages of human isolates in groups 1 and 2 that were positive for eae were 92 and 27%, respectively, and the percentages of bovine isolates in groups 1 to 3 that were positive for eae were 78, 15, and 19%, respectively. The frequencies of both ehxA and eae were significantly higher for group 1 isolates than for group 2 isolates. The presence of the ehxA gene was associated with serotype, as was the presence of the eae gene. Some serotypes, such as O117:H4, lacked both eae and ehxA and have been associated with severe disease, but only infrequently. The slt-I genes were more frequent in group 1 isolates than in group 2 isolates, and the slt-II genes were more frequent in group 2 isolates than in group 1 isolates. In a second experiment we determined the occurrence of the ehxA and slt genes in E. coli isolated from bovine feces. Fecal samples from 175 animals were streaked onto washed sheep erythrocyte agar plates. Eight E. coli-like colonies representing all of the morphological types were transferred to MacConkey agar. A total of 1, 080 E. coli isolates were examined, and the ehxA gene was detected in 12 independent strains, only 3 of which were positive for slt. We concluded that the ehxA gene was less correlated with virulence than the eae gene was and that EHEC hemolysin alone has limited value for screening bovine feces for pathogenic SLTEC because of presence of the ehxA gene in bovine isolates that are not SLTEC.

Animals↗
PubMed1985

Colonization of human wounds by Escherichia vulneris and Escherichia hermannii.

In this report we present clinical descriptions of 12 Hawaiian patients from whom Escherichia vulneris or E. hermannii strains were isolated. All but two patients had soft-tissue infections with multiple bacteria, particularly Staphylococcus aureus. The other two had purulent conjunctivitis associated with S. aureus and infected malignant peritonitis with multiple organisms, respectively. In none of the cases were the Escherichia spp. found in abundant quantities or considered pathogenic. In preliminary animal pathogenicity studies, 12 strains each of E. vulneris and E. hermannii failed to cause serious symptoms in 4-week-old mice when 10(7) cells were injected intraperitoneally. When 10(6) cells were used, none of these bacterial strains injected into mouse soft tissue was capable of producing persistent wound infections. Susceptibility studies of 40 strains of these bacteria to 20 different antimicrobial agents showed that they were susceptible to third-generation cephalosporins as well as to most other cephalosporins, aminoglycosides, trimethoprim, and sulfamethoxazole-trimethoprim; these strains were only marginally susceptible or resistant to penicillin, tetracycline, chloramphenicol, and nitrofurantoin.

Adult↗