scholarly journals Evolution of the iss Gene in Escherichia coli

2008 ◽  
Vol 74 (8) ◽  
pp. 2360-2369 ◽  
Author(s):  
Timothy J. Johnson ◽  
Yvonne M. Wannemuehler ◽  
Lisa K. Nolan
Keyword(s):  
Escherichia Coli ◽  
Neonatal Meningitis ◽  
Additional Tool ◽  
E Coli ◽  
Virulence Plasmids ◽  
Survival Gene ◽  
Type 3 ◽  
Manganese Transport ◽  
Iron And Manganese

ABSTRACT The increased serum survival gene iss has long been recognized for its role in extraintestinal pathogenic Escherichia coli (ExPEC) virulence. iss has been identified as a distinguishing trait of avian ExPEC but not of human ExPEC. This gene has been localized to large virulence plasmids and shares strong similarities with the bor gene from bacteriophage λ. Here, we demonstrate that three alleles of iss occur among E. coli isolates that appear to have evolved from a common λ bor precursor. In addition to the occurrence of iss on the ColV/BM virulence plasmids, at least two iss alleles occur within the E. coli chromosome. One of these alleles (designated type 3) was found to occur in the genomes of all currently sequenced ExPEC strains on a similar prophage element that also harbors the Sit iron and manganese transport system. When the prevalence of the three iss types was examined among 487 E. coli isolates, the iss type 3 gene was found to occur at a high frequency among ExPEC isolates, irrespective of the host source. The plasmid-borne iss allele (designated type 1) was highly prevalent among avian pathogenic E. coli and neonatal meningitis-associated E. coli isolates but not among uropathogenic E. coli isolates. This study demonstrates the evolution of iss in E. coli and provides an additional tool for discriminating among E. coli pathotypes through the differentiation of the three iss allele types and bor.

scholarly journals Escherichia coli K1 RS218 Interacts with Human Brain Microvascular Endothelial Cells via Type 1 Fimbria Bacteria in the Fimbriated State

2005 ◽  
Vol 73 (5) ◽  
pp. 2923-2931 ◽  
Author(s):  
Ching-Hao Teng ◽  
Mian Cai ◽  
Sooan Shin ◽  
Yi Xie ◽  
Kee-Jun Kim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Endothelial Cells ◽  
Human Brain ◽  
Neonatal Meningitis ◽  
Microvascular Endothelial Cells ◽  
Brain Microvascular Endothelial Cells ◽  
E Coli ◽  
Microvascular Endothelial

ABSTRACT Escherichia coli K1 is a major gram-negative organism causing neonatal meningitis. E. coli K1 binding to and invasion of human brain microvascular endothelial cells (HBMEC) are a prerequisite for E. coli penetration into the central nervous system in vivo. In the present study, we showed using DNA microarray analysis that E. coli K1 associated with HBMEC expressed significantly higher levels of the fim genes compared to nonassociated bacteria. We also showed that E. coli K1 binding to and invasion of HBMEC were significantly decreased with its fimH deletion mutant and type 1 fimbria locked-off mutant, while they were significantly increased with its type 1 fimbria locked-on mutant. E. coli K1 strains associated with HBMEC were predominantly type 1 fimbria phase-on (i.e., fimbriated) bacteria. Taken together, we showed for the first time that type 1 fimbriae play an important role in E. coli K1 binding to and invasion of HBMEC and that type 1 fimbria phase-on E. coli is the major population interacting with HBMEC.

scholarly journals Oxidation of Phenolate Siderophores by the Multicopper Oxidase Encoded by the Escherichia coli yacK Gene

2001 ◽  
Vol 183 (16) ◽  
pp. 4866-4875 ◽  
Author(s):  
Chulhwan Kim ◽  
W. Walter Lorenz ◽  
J. Todd Hoopes ◽  
Jeffrey F. D. Dean
Keyword(s):  
Escherichia Coli ◽  
Multicopper Oxidase ◽  
Epr Spectra ◽  
Significant Activity ◽  
Paramagnetic Resonance ◽  
E Coli ◽  
Copper Addition ◽  
Type 1 Copper ◽  
Type 3

ABSTRACT A gene (yacK) encoding a putative multicopper oxidase (MCO) was cloned from Escherichia coli, and the expressed enzyme was demonstrated to exhibit phenoloxidase and ferroxidase activities. The purified protein contained six copper atoms per polypeptide chain and displayed optical and electron paramagnetic resonance (EPR) spectra consistent with the presence of type 1, type 2, and type 3 copper centers. The strong opticalA 610 (Ε610 = 10,890 M−1 cm−1) and copper stoichiometry were taken as evidence that, similar to ceruloplasmin, the enzyme likely contains multiple type 1 copper centers. The addition of copper led to immediate and reversible changes in the optical and EPR spectra of the protein, as well as decreased thermal stability of the enzyme. Copper addition also stimulated both the phenoloxidase and ferroxidase activities of the enzyme, but the other metals tested had no effect. In the presence of added copper, the enzyme displayed significant activity against two of the phenolate siderophores utilized by E. coli for iron uptake, 2,3-dihydroxybenzoate and enterobactin, as well as 3-hydroxyanthranilate, an iron siderophore utilized bySaccharomyces cerevisiae. Oxidation of enterobactin produced a colored precipitate suggestive of the polymerization reactions that characterize microbial melanization processes. As oxidation should render the phenolate siderophores incapable of binding iron, yacK MCO activity could influence levels of free iron in the periplasm in response to copper concentration. This mechanism may explain, in part, how yacK MCO moderates the sensitivity of E. coli to copper.

scholarly journals Avian-Pathogenic Escherichia coli Strains Are Similar to Neonatal Meningitis E. coli Strains and Are Able To Cause Meningitis in the Rat Model of Human Disease

2010 ◽  
Vol 78 (8) ◽  
pp. 3412-3419 ◽  
Author(s):  
Kelly A. Tivendale ◽  
Catherine M. Logue ◽  
Subhashinie Kariyawasam ◽  
Dianna Jordan ◽  
Ashraf Hussein ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rat Model ◽  
Neonatal Meningitis ◽  
Zoonotic Potential ◽  
E Coli ◽  
Virulence Plasmids ◽  
Pathogenic Escherichia Coli ◽  
Typing Methods ◽  
Tract Infections

ABSTRACT Escherichia coli strains causing avian colibacillosis and human neonatal meningitis, urinary tract infections, and septicemia are collectively known as extraintestinal pathogenic E. coli (ExPEC). Characterization of ExPEC strains using various typing techniques has shown that they harbor many similarities, despite their isolation from different host species, leading to the hypothesis that ExPEC may have zoonotic potential. The present study examined a subset of ExPEC strains: neonatal meningitis E. coli (NMEC) strains and avian-pathogenic E. coli (APEC) strains belonging to the O18 serogroup. The study found that they were not easily differentiated on the basis of multilocus sequence typing, phylogenetic typing, or carriage of large virulence plasmids. Among the APEC strains examined, one strain was found to be an outlier, based on the results of these typing methods, and demonstrated reduced virulence in murine and avian pathogenicity models. Some of the APEC strains tested in a rat model of human neonatal meningitis were able to cause meningitis, demonstrating APEC's ability to cause disease in mammals, lending support to the hypothesis that APEC strains have zoonotic potential. In addition, some NMEC strains were able to cause avian colisepticemia, providing further support for this hypothesis. However, not all of the NMEC and APEC strains tested were able to cause disease in avian and murine hosts, despite the apparent similarities in their known virulence attributes. Thus, it appears that a subset of NMEC and APEC strains harbors zoonotic potential, while other strains do not, suggesting that unknown mechanisms underlie host specificity in some ExPEC strains.

scholarly journals Avian Pathogenic Escherichia coli (APEC): An Overview of Virulence and Pathogenesis Factors, Zoonotic Potential, and Control Strategies

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 467
Author(s):  
Dipak Kathayat ◽  
Dhanashree Lokesh ◽  
Sochina Ranjit ◽  
Gireesh Rajashekara
Keyword(s):  
Escherichia Coli ◽  
Current Status ◽  
Neonatal Meningitis ◽  
Clear Understanding ◽  
Zoonotic Potential ◽  
Secretion Systems ◽  
Avian Pathogenic Escherichia Coli ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Tract Infections

Avian pathogenic Escherichia coli (APEC) causes colibacillosis in avian species, and recent reports have suggested APEC as a potential foodborne zoonotic pathogen. Herein, we discuss the virulence and pathogenesis factors of APEC, review the zoonotic potential, provide the current status of antibiotic resistance and progress in vaccine development, and summarize the alternative control measures being investigated. In addition to the known virulence factors, several other factors including quorum sensing system, secretion systems, two-component systems, transcriptional regulators, and genes associated with metabolism also contribute to APEC pathogenesis. The clear understanding of these factors will help in developing new effective treatments. The APEC isolates (particularly belonging to ST95 and ST131 or O1, O2, and O18) have genetic similarities and commonalities in virulence genes with human uropathogenic E. coli (UPEC) and neonatal meningitis E. coli (NMEC) and abilities to cause urinary tract infections and meningitis in humans. Therefore, the zoonotic potential of APEC cannot be undervalued. APEC resistance to almost all classes of antibiotics, including carbapenems, has been already reported. There is a need for an effective APEC vaccine that can provide protection against diverse APEC serotypes. Alternative therapies, especially the virulence inhibitors, can provide a novel solution with less likelihood of developing resistance.

scholarly journals Transcriptome analysis of Escherichia coli K1 after therapy with hesperidin conjugated with silver nanoparticles

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Abdulkader Masri ◽  
Naveed Ahmed Khan ◽  
Muhammad Zarul Hanifah Md Zoqratt ◽  
Qasim Ayub ◽  
Ayaz Anwar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Neonatal Meningitis ◽  
E Coli ◽  
Drug Candidates ◽  
Metabolic Genes ◽  
Genetic Mechanisms ◽  
Cell Stress Response

Abstract Backgrounds Escherichia coli K1 causes neonatal meningitis. Transcriptome studies are indispensable to comprehend the pathology and biology of these bacteria. Recently, we showed that nanoparticles loaded with Hesperidin are potential novel antibacterial agents against E. coli K1. Here, bacteria were treated with and without Hesperidin conjugated with silver nanoparticles, and silver alone, and 50% minimum inhibitory concentration was determined. Differential gene expression analysis using RNA-seq, was performed using Degust software and a set of genes involved in cell stress response and metabolism were selected for the study. Results 50% minimum inhibitory concentration with silver-conjugated Hesperidin was achieved with 0.5 μg/ml of Hesperidin conjugated with silver nanoparticles at 1 h. Differential genetic analysis revealed the expression of 122 genes (≥ 2-log FC, P< 0.01) in both E. coli K1 treated with Hesperidin conjugated silver nanoparticles and E. coli K1 treated with silver alone, compared to untreated E. coli K1. Of note, the expression levels of cation efflux genes (cusA and copA) and translocation of ions, across the membrane genes (rsxB) were found to increase 2.6, 3.1, and 3.3- log FC, respectively. Significant regulation was observed for metabolic genes and several genes involved in the coordination of flagella. Conclusions The antibacterial mechanism of nanoparticles maybe due to disruption of the cell membrane, oxidative stress, and metabolism in E. coli K1. Further studies will lead to a better understanding of the genetic mechanisms underlying treatment with nanoparticles and identification of much needed novel antimicrobial drug candidates.

Comparison of colony and stool blots for detection of enteropathogens by DNA probes

1991 ◽  
Vol 37 (5) ◽  
pp. 407-410
Author(s):  
Mônica A. M. Vieira ◽  
Beatriz E. C. Guth ◽  
Tânia A. T. Gomes
Keyword(s):  
Escherichia Coli ◽  
Key Words ◽  
Sensitivity And Specificity ◽  
Dna Probes ◽  
Type I ◽  
Enteropathogenic Escherichia Coli ◽  
Key Words Dna ◽  
E Coli ◽  
Heat Stable

DNA probes that identify genes coding for heat-labile type I (LT-I) and heat-stable type 1 (ST-I) enterotoxins, enteropathogenic Escherichia coli adherence factor (EAF), and Shigella-like, invasiveness (INV) are used to evaluate the sensitivity and specificity of stool blots in comparison with the sensitivity and specificity of colony blots in detecting enteropathoghens. The sensitivities of the probes in stool blots are 91.7% for the LT-I probe, 76.9% for the ST-I probes, 78.9% for the EAF probe, and 45.5% for the INV probe. The specificity of all probes is higher than 95%. In general, the stool blot method identifies as many if not more LT-I-, ST-I-, and EAF-producing E. coli infections than the colony blots. Key words: DNA probes, stool blots, enteropathogens, diagnosis.

scholarly journals Role of the ceramide-signaling pathway in cytokine responses to P-fimbriated Escherichia coli.

1996 ◽  
Vol 183 (3) ◽  
pp. 1037-1044 ◽  
Author(s):  
M Hedlund ◽  
M Svensson ◽  
A Nilsson ◽  
R D Duan ◽  
C Svanborg
Keyword(s):  
Escherichia Coli ◽  
Signaling Pathway ◽  
Kinase Inhibitors ◽  
Human Kidney ◽  
Cytokine Response ◽  
Protein Kinase Inhibitors ◽  
E Coli ◽  
Type 1 Fimbriae ◽  
Outer Leaflet

Escherichia coli express fimbriae-associated adhesins through which they attach to mucosal cells and activate a cytokine response. The receptors for E. coli P fimbriae are the globoseries of glycosphingolipids; Gal alpha 1--&gt;4Gal beta-containing oligosaccharides bound to ceramide in the outer leaflet of the lipid bilayer. The receptors for type 1 fimbriae are mannosylated glycoproteins rather than glycolipids. This study tested the hypothesis that P-fimbriated E. coli elicit a cytokine response through the release of ceramide in the receptor-bearing cell. We used the A498 human kidney cell line, which expressed functional receptors for P and type 1 fimbriae and secreted higher levels of interleukin (IL)-6 when exposed to the fimbriated strains than to isogenic nonfimbriated controls. P-fimbriated E. coli caused the release of ceramide and increased the phosphorylation of ceramide to ceramide 1-phosphate. The IL-6 response to P-fimbriated E. coli was reduced by inhibitors of serine/threonine kinases but not by other protein kinase inhibitors. In contrast, ceramide levels were not influenced by type 1-fimbriated E. coli, and the IL-6 response was insensitive to the serine/threonine kinase inhibitors. These results demonstrate that the ceramide-signaling pathway is activated by P-fimbriated E. coli, and that the receptor specificity of the P fimbriae influences this process. We propose that this activation pathway contributes to the cytokine induction by P-fimbriated E. coli in epithelial cells.

scholarly journals Genotypic and Phenotypic Traits That Distinguish Neonatal Meningitis-Associated Escherichia coli from Fecal E. coli Isolates of Healthy Human Hosts

2012 ◽  
Vol 78 (16) ◽  
pp. 5824-5830 ◽  
Author(s):  
Catherine M. Logue ◽  
Curt Doetkott ◽  
Paul Mangiamele ◽  
Yvonne M. Wannemuehler ◽  
Timothy J. Johnson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Phylogenetic Group ◽  
Neonatal Meningitis ◽  
Phenotypic Traits ◽  
Healthy Human ◽  
Content Type ◽  
Plasmid Content ◽  
E Coli ◽  
Healthy Humans ◽  
Definition Of

ABSTRACTNeonatal meningitisEscherichia coli(NMEC) is one of the top causes of neonatal meningitis worldwide. Here, 85 NMEC and 204 fecalE. coliisolates from healthy humans (HFEC) were compared for possession of traits related to virulence, antimicrobial resistance, and plasmid content. This comparison was done to identify traits that typify NMEC and distinguish it from commensal strains to refine the definition of the NMEC subpathotype, identify traits that might contribute to NMEC pathogenesis, and facilitate choices of NMEC strains for future study. A large number ofE. colistrains from both groups were untypeable, with the most common serogroups occurring among NMEC being O18, followed by O83, O7, O12, and O1. NMEC strains were more likely than HFEC strains to be assigned to the B2 phylogenetic group. Few NMEC or HFEC strains were resistant to antimicrobials. Genes that best discriminated between NMEC and HFEC strains and that were present in more than 50% of NMEC isolates were mainly from extraintestinal pathogenicE. coligenomic and plasmid pathogenicity islands. Several of these defining traits had not previously been associated with NMEC pathogenesis, are of unknown function, and are plasmid located. Several genes that had been previously associated with NMEC virulence did not dominate among the NMEC isolates. These data suggest that there is much about NMEC virulence that is unknown and that there are pitfalls to studying single NMEC isolates to represent the entire subpathotype.

scholarly journals A New Clone Sweeps Clean: the Enigmatic Emergence of Escherichia coli Sequence Type 131

2014 ◽  
Vol 58 (9) ◽  
pp. 4997-5004 ◽  
Author(s):  
Ritu Banerjee ◽  
James R. Johnson
Keyword(s):  
Escherichia Coli ◽  
Sequence Type ◽  
Rapid Expansion ◽  
Future Research ◽  
Content Type ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Phylogenetic Studies ◽  
Ecological Success

ABSTRACTEscherichia colisequence type 131 (ST131) is an extensively antimicrobial-resistantE. coliclonal group that has spread explosively throughout the world. Recent molecular epidemiologic and whole-genome phylogenetic studies have elucidated the fine clonal structure of ST131, which comprises multiple ST131 subclones with distinctive resistance profiles, including the (nested) H30, H30-R, and H30-Rx subclones. The most prevalent ST131 subclone, H30, arose from a single common fluoroquinolone (FQ)-susceptible ancestor containing allele 30 offimH(type 1 fimbrial adhesin gene). An early H30 subclone member acquired FQ resistance and launched the rapid expansion of the resulting FQ-resistant subclone, H30-R. Subsequently, a member of H30-R acquired the CTX-M-15 extended-spectrum beta-lactamase and launched the rapid expansion of the CTX-M-15-containing subclone within H30-R, H30-Rx. Clonal expansion clearly is now the dominant mechanism for the rising prevalence of both FQ resistance and CTX-M-15 production in ST131 and inE. coligenerally. Reasons for the successful dissemination and expansion of the key ST131 subclones remain undefined but may include increased transmissibility, greater ability to colonize and/or persist in the intestine or urinary tract, enhanced virulence, and more-extensive antimicrobial resistance compared to otherE. coli. Here we discuss the epidemiology and molecular phylogeny of ST131 and its key subclones, possible mechanisms for their ecological success, implications of their widespread dissemination, and future research needs.

scholarly journals P fimbriae and other adhesins enhance intestinal persistence of Escherichia coli in early infancy

1998 ◽  
Vol 121 (3) ◽  
pp. 599-608 ◽  
Author(s):  
I. ADLERBERTH ◽  
C. SVANBORG ◽  
B. CARLSSON ◽  
L. MELLANDER ◽  
L.-Å. HANSON ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Line ◽  
Intestinal Epithelial Cells ◽  
Antigen Expression ◽  
Intestinal Epithelial ◽  
E Coli ◽  
O Antigen ◽  
Ht 29 ◽  
Intestinal Persistence

Resident and transient Escherichia coli strains were identified in the rectal flora of 22 Pakistani infants followed from birth to 6 months of age. All strains were tested for O-antigen expression, adhesin specificity (P fimbriae, other mannose-resistant adhesins or type 1 fimbriae) and adherence to the colonic cell line HT-29. Resident strains displayed higher mannose- resistant adherence to HT-29 cells, and expressed P fimbriae (P=0·0036) as well as other mannose-resistant adhesins (P=0·012) more often than transient strains. In strains acquired during the first month of life, P fimbriae were 12 times more frequent in resident than in transient strains (P=0·0006). The O-antigen distribution did not differ between resident and transient strains, and none of the resident P-fimbriated strains belonged to previously recognized uropathogenic clones. The results suggest that adhesins mediating adherence to intestinal epithelial cells, especially P fimbriae, enhance the persistence of E. coli in the large intestine of infants.

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