scholarly journals Comparative Pathogenomics of Escherichia coli : Polyvalent Vaccine Target Identification Through Virulome Analysis

2021 ◽  
Author(s):  
J.R. Clark ◽  
A.M. Maresso
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Vaccine Development ◽  
Target Identification ◽  
Iron Acquisition ◽  
Model Organism ◽  
Comparative Genomic ◽  
E Coli ◽  
Polyvalent Vaccine ◽  
Group 2

Comparative genomics of bacterial pathogens has been useful for revealing potential virulence factors. Escherichia coli is a significant cause of human morbidity and mortality worldwide but can also exist as a commensal in the human gastrointestinal tract. With many sequenced genomes, it has served as a model organism for comparative genomic studies to understand the link between genetic content and potential for virulence. To date, however, no comprehensive analysis of its complete “virulome” has been performed for the purpose of identifying universal or pathotype-specific targets for vaccine development. Here, we describe the construction of a pathotype database of 107 well-characterized completely sequenced pathogenic and non-pathogenic E. coli strains, which we annotated for major virulence factors (VFs). Data are cross referenced for patterns against pathotype, phylogroup, and sequence type and results verified against all 1,348 complete E. coli chromosomes in the NCBI RefSeq database. Our results demonstrate that phylogroup drives many of the “pathotype-associated” VFs, and ExPEC-associated VFs are found predominantly within the B2/D/F/G phylogenetic clade, suggesting these phylogroups are more adapted to infect human hosts. Finally, we used this information to propose polyvalent vaccine targets with specificity towards extraintestinal strains, targeting key invasive strategies including immune evasion (group 2 capsule), iron acquisition (FyuA, IutA, Sit), adherence (SinH, Afa, Pap, Sfa, Iha), and toxins (Usp, Sat, Vat, Cdt, Cnf1, HlyA). While many of these targets have been proposed before, this work is the first to examine their pathotype and phylogroup distribution and how they may be targeted together to prevent disease.

scholarly journals Virulence and antibiotic resistance profile of avian Escherichia coli strains isolated from colibacillosis lesions in central of Algeria

2019 ◽  
Vol 12 (11) ◽  
pp. 1840-1848 ◽  
Author(s):  
Nacima Meguenni ◽  
Nathalie Chanteloup ◽  
Angelina Tourtereau ◽  
Chafika Ali Ahmed ◽  
Saliha Bounar-Kechih ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Iron Acquisition ◽  
Virulence Gene ◽  
Resistance Profile ◽  
E Coli ◽  
Antibiotic Resistance Profile ◽  
Embryo Lethality

Background and Aim: Avian pathogenic Escherichia coli cause extensive mortality in poultry flocks, leading to extensive economic losses. To date, in Algeria, little information has been available on virulence potential and antibiotics resistance of avian E. coli isolates. Therefore, the aim of this study was the characterization of virulence genes and antibiotic resistance profile of Algerian E. coli strains isolated from diseased broilers. Materials and Methods: In this study, 43 avian E. coli strains isolated from chicken colibacillosis lesions at different years were analyzed to determine their contents in 10 virulence factors by polymerase chain reaction, antimicrobial susceptibility to 22 antibiotics belonging to six different chemical classes and genomic diversity by pulsed-field gel electrophoresis (PFGE). Results: Mainly E. coli isolates (58.1%) carried two at six virulence genes and the most frequent virulence gene association detected were ompT (protectin), hlyF (hemolysin) with 55.8% (p<0.001), and iroN, sitA (iron acquisition/uptake systems), and iss (protectin) with 41.8% (p<0.001). Some strains were diagnosed as virulent according to their virulence gene profile. Indeed, 23.25% of the isolates harbored iroN, ompT, hlyF, iss, and sitA combination, 14% ompT, hlyF, and frzorf4 (sugar metabolism), and 11,6% iroN, hlyF, ompT, iss, iutA (iron acquisition/uptake systems), and frzorf4. The chicken embryo lethality assay performed on five isolates confirmed the potential virulence of these strains. All isolates submitted to PFGE analysis yielded different genetic profiles, which revealed their diversity. Overall, 97.2% of the isolates were resistant to at least one antibiotic and 53.5% demonstrated multi-antimicrobial resistance to three different antimicrobial classes. The highest resistance levels were against nalidixic acid (83.4%), amoxicillin and ampicillin (83.3%), ticarcillin (80.5%), pipemidic acid (75%), and triméthoprim-sulfamethoxazole (66.6%). For beta-lactam class, the main phenotype observed belonged to broad-spectrum beta-lactamases. However, extended-spectrum beta-lactamase associated with three at six virulence factors was also detected in 13 isolates. Two of them were attested virulent as demonstrated in the embryo lethality test which constitutes a real public threat. Conclusion: It would be imperative in avian production to discourage misuse while maintaining constant vigilance guidelines and regulations, to limit and rationalize antimicrobial use.

scholarly journals Defining Genomic Islands and Uropathogen-Specific Genes in Uropathogenic Escherichia coli

2007 ◽  
Vol 189 (9) ◽  
pp. 3532-3546 ◽  
Author(s):  
Amanda L. Lloyd ◽  
David A. Rasko ◽  
Harry L. T. Mobley
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Iron Acquisition ◽  
Genomic Islands ◽  
Comparative Genomic ◽  
Upec Strain ◽  
E Coli ◽  
Strain Collection ◽  
Tract Infections ◽  
K 12

ABSTRACT Uropathogenic Escherichia coli (UPEC) strains are responsible for the majority of uncomplicated urinary tract infections, which can present clinically as cystitis or pyelonephritis. UPEC strain CFT073, isolated from the blood of a patient with acute pyelonephritis, was most cytotoxic and most virulent in mice among our strain collection. Based on the genome sequence of CFT073, microarrays were utilized in comparative genomic hybridization (CGH) analysis of a panel of uropathogenic and fecal/commensal E. coli isolates. Genomic DNA from seven UPEC (three pyelonephritis and four cystitis) isolates and three fecal/commensal strains, including K-12 MG1655, was hybridized to the CFT073 microarray. The CFT073 genome contains 5,379 genes; CGH analysis revealed that 2,820 (52.4%) of these genes were common to all 11 E. coli strains, yet only 173 UPEC-specific genes were found by CGH to be present in all UPEC strains but in none of the fecal/commensal strains. When the sequences of three additional sequenced UPEC strains (UTI89, 536, and F11) and a commensal strain (HS) were added to the analysis, 131 genes present in all UPEC strains but in no fecal/commensal strains were identified. Seven previously unrecognized genomic islands (>30 kb) were delineated by CGH in addition to the three known pathogenicity islands. These genomic islands comprise 672 kb of the 5,231-kb (12.8%) genome, demonstrating the importance of horizontal transfer for UPEC and the mosaic structure of the genome. UPEC strains contain a greater number of iron acquisition systems than do fecal/commensal strains, which is reflective of the adaptation to the iron-limiting urinary tract environment. Each strain displayed distinct differences in the number and type of known virulence factors. The large number of hypothetical genes in the CFT073 genome, especially those shown to be UPEC specific, strongly suggests that many urovirulence factors remain uncharacterized.

scholarly journals Virulence Genes Profiles and Phylogenetic Origin of Escherichia coli from Acute and Chronic Intestinal Diseases Revealed by Comparative Genomic Hybridization Microarray

2012 ◽  
Vol 61 (2) ◽  
pp. 105-110
Author(s):  
BEATA SOBIESZCZAŃSKA ◽  
URSZULA KASPRZYKOWSKA ◽  
MICHAŁ TURNIAK ◽  
HENRYK MACIEJEWSKI ◽  
ROMAN FRANICZEK ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Virulence Factors ◽  
Acute Diarrhea ◽  
Virulence Genes ◽  
Comparative Genomic ◽  
Control Group ◽  
Intestinal Diseases ◽  
E Coli

The association between Escherichia coli virulence factors and chronic intestinal disorders is mostly unknown. The presented study compared the distribution of virulence genes and phylogroups among E. coli isolated from chronic intestinal disorders such as Crohn's disease and irritable bowel syndrome (IBS) with strains isolated from patients with acute diarrhea as a control group. The presence of 159 virulence genes corresponding to known E. coli pathotypes was determined among 78 E. coli archive strains isolated from IBS, acute diarrhea and Crohn's disease using CGH microarray. E. coli isolated from IBS demonstrated a mosaic of virulence genes specific to enteropathogenic, enterotoxigenic, enterohemorrhagic E. coli strains and Shigella species. In contrast, virulence factors and phylogroups distribution among E. coli isolated from children with acute diarrhea was similar to extraintestinal E. coli strains that probably acquired some virulence genes. The acquisition of virulence genes might have an impact on diarrheagenic potential of these strains. On the other hand, E. coli isolated from children with Crohn's disease seem to be similar to adherent-invasive E. coli strains (AIEC), as it lack most known virulence genes. The presented study showed that these analyzed groups of E. coli strains differed from each other with the respect to the distribution of virulence genes. The differences in gene content support the idea that the participation of E. coli in chronic intestinal diseases is mostly related to virulence potential of these strains.

scholarly journals Escherichia coli virulence factors iutA, an iron acquisition factor, and ibeA, an invasion factor, are related to severity of bacteremic acute biliary tract infections

2020 ◽  
Author(s):  
Mahoko Ikeda ◽  
Tatsuya Kobayashi ◽  
Fumie Fujimoto ◽  
Yuta Okada ◽  
Yoshimi Higurashi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Tract Infection ◽  
Virulence Factors ◽  
Biliary Tract ◽  
Iron Acquisition ◽  
Care Hospital ◽  
Biliary Tract Infection ◽  
E Coli ◽  
Severe Group ◽  
Tract Infections

Abstract BackgroundAlthough Escherichia coli is the most frequently isolated organism in acute biliary tract infections with bacteremia, data regarding its virulence are limited.ResultsBacteremic acute biliary tract infection cases in a retrospective study were collected from 2013 to 2015 at a tertiary care hospital in Japan. Factors related to the severity of infection were investigated, including patient background, phylogenetic typing, and virulence factors of E. coli, such as adhesion, invasion, toxins, and iron acquisition. In total, 72 E. coli strains were identified in 71 cases, most of which primarily belonged to the phylogenetic B2 group (68%). The presence of IutA (77.3% in the non-severe group, 46.4% in the severe group, P = 0.011) and ibeA (9.1% in the non-severe group, and 35.7% in the severe group, P = 0.012) were significantly associated with severity of infection, whereas patient characteristics did not relate to the severity of infection.ConclusionsWe showed that bacteremic E. coli strains from acute biliary tract infections belonged to a virulent (B2) group. The severity of biliary tract infection depended on iutA and ibeA.

scholarly journals Escherichia coli Bcteriuria in pregnant women in Ghana: Antibiotic resistance pattern, Virulence Factors and Resistant genetic markers

2018 ◽  
Author(s):  
Forson Obeng Akua ◽  
Wilson Bright ◽  
David Nana-Adjei ◽  
Marjorie Ntiwaa Quarchie ◽  
Noah Obeng-Nkuramah
Keyword(s):  
Escherichia Coli ◽  
Pregnant Women ◽  
Virulence Factors ◽  
Iron Acquisition ◽  
Asymptomatic Bacteriuria ◽  
Resistance Pattern ◽  
Neonatal Infections ◽  
E Coli ◽  
Resistant Genes ◽  
Polymerase Chain

AbstractThe relevance of Escherichia coli associated bacteriuria infection in pregnant women is poorly understood, despite these strains sharing a similar virulence profile with other extra intestinal pathogenic E. coli producing severe obstetric and neonatal infections. We characterized and determined the antimicrobial susceptibility, resistant genes and virulence profiles of 82 E. coli isolates associated with asymptomatic bacteriuria in some pregnant in five very distinct hospitals in the Volta region from January, 2016 to April, 2016 using Kirby-Bauer disc diffusion and polymerase chain reaction.High levels of antimicrobial resistance was observed to Ampicillin (79.3%), Tetracycline (70.7%) and Cotrimoxazole (59.8%), except for Cefuroxime (32.9%). Resistant genes analyses revealed 58.5% were positive for BlaTEM and 14.6% for aph(3)-Ia(aphA2). Virulence factors (VFs) was more widespread in pregnant women in the 2nd and 3rd trimesters than 1st trimester. VFs relating to adhesion (papC and iha), Protectins (traT), aerobactin acquisition (iutA) and iron acquisition systems (fyuA and irp2) were more prevalent in the resistant E. coli isolates. This study provides additional evidence for a link in bacteriuria and transmission of extra-intestinal E. coli in pregnant women to cause multi-resistant severe obstetric or neonatal infections. Considering the involvement of extra-intestinal E. coli in infections, our results may be helpful to develop strategies to prevent maternal and/ neonatal infections. In addition continuous surveillance is required to guide appropriate antibiotic usage in pregnant women.

scholarly journals Iron Acquisition of Urinary Tract Infection Escherichia coli Involves Pathogenicity in Caenorhabditis elegans

2021 ◽  
Vol 9 (2) ◽  
pp. 310
Author(s):  
Masayuki Hashimoto ◽  
Yi-Fen Ma ◽  
Sin-Tian Wang ◽  
Chang-Shi Chen ◽  
Ching-Hao Teng
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Caenorhabditis Elegans ◽  
Large Scale ◽  
Iron Acquisition ◽  
Infection Model ◽  
High Throughput Analysis ◽  
E Coli ◽  
C Elegans ◽  
Tract Infections

Uropathogenic Escherichia coli (UPEC) is a major bacterial pathogen that causes urinary tract infections (UTIs). The mouse is an available UTI model for studying the pathogenicity; however, Caenorhabditis elegans represents as an alternative surrogate host with the capacity for high-throughput analysis. Then, we established a simple assay for a UPEC infection model with C. elegans for large-scale screening. A total of 133 clinically isolated E. coli strains, which included UTI-associated and fecal isolates, were applied to demonstrate the simple pathogenicity assay. From the screening, several virulence factors (VFs) involved with iron acquisition (chuA, fyuA, and irp2) were significantly associated with high pathogenicity. We then evaluated whether the VFs in UPEC were involved in the pathogenicity. Mutants of E. coli UTI89 with defective iron acquisition systems were applied to a solid killing assay with C. elegans. As a result, the survival rate of C. elegans fed with the mutants significantly increased compared to when fed with the parent strain. The results demonstrated, the simple assay with C. elegans was useful as a UPEC infectious model. To our knowledge, this is the first report of the involvement of iron acquisition in the pathogenicity of UPEC in a C. elegans model.

scholarly journals The prevalence of the iutA and ibeA genes in Escherichia coli isolates from severe and non-severe patients with bacteremic acute biliary tract infection is significantly different

Gut Pathogens ◽  
2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Mahoko Ikeda ◽  
Tatsuya Kobayashi ◽  
Fumie Fujimoto ◽  
Yuta Okada ◽  
Yoshimi Higurashi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Tract Infection ◽  
Biliary Tract ◽  
Iron Acquisition ◽  
Tertiary Care ◽  
Care Hospital ◽  
Biliary Tract Infection ◽  
E Coli ◽  
Severe Group ◽  
Tract Infections

Abstract Background Although Escherichia coli is the most frequently isolated microorganism in acute biliary tract infections with bacteremia, data regarding its virulence are limited. Results Information on cases of bacteremia in acute biliary tract infection in a retrospective study was collected from 2013 to 2015 at a tertiary care hospital in Japan. Factors related to the severity of infection were investigated, including patient background, phylogenetic typing, and virulence factors of E. coli, such as adhesion, invasion, toxins, and iron acquisition. In total, 72 E. coli strains were identified in 71 cases, most of which primarily belonged to the B2 phylogroup (68.1%). The presence of the iutA gene (77.3% in the non-severe group, 46.4% in the severe group, P = 0.011) and the ibeA gene (9.1% in the non-severe group, and 35.7% in the severe group, P = 0.012) was significantly associated with the severity of infection. Among the patient characteristics, diabetes mellitus with organ involvement and alkaline phosphatase were different in the severe and non-severe groups. Conclusions We showed that bacteremic E. coli strains from acute biliary tract infections belonged to the virulent (B2) phylogroup. The prevalence of the iutA and ibeA genes between the two groups of bacteremia severity was significantly different.

scholarly journals The AIDA Autotransporter System Is Associated with F18 and Stx2e in Escherichia coli Isolates from Pigs Diagnosed with Edema Disease and Postweaning Diarrhea

2001 ◽  
Vol 8 (1) ◽  
pp. 143-149 ◽  
Author(s):  
Ulla Niewerth ◽  
Andreas Frey ◽  
Thomas Voss ◽  
Chantal Le Bouguénec ◽  
Georg Baljer ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Western Blot ◽  
Virulence Factors ◽  
Rapid Screening ◽  
Edema Disease ◽  
E Coli ◽  
Large Numbers ◽  
High Prevalence ◽  
Pcr Method ◽  
Postweaning Diarrhea

ABSTRACT Pathogenic Escherichia coli strains are known to cause edema disease (ED) and postweaning diarrhea (PWD) in piglets. Although the exact mechanisms of pathogenicity that lead to ED-PWD remain to be elucidated, E. coli-borne Shiga-like toxin and adhesion-mediating virulence factors such as F18 adhesin or F4 fimbriae are believed to play a central role in ED-PWD. In light of these observations we investigated whether another E. coliadhesin, the plasmid-encoded AIDA (adhesin involved in diffuse adherence) might also be present in ED-PWD-causing E. coli isolates. For rapid screening for the AIDA system in large numbers of isolates, a multiplex PCR method along with a duplex Western blot procedure was developed. When screening 104 strains obtained from pigs with or without ED-PWD, we observed a high prevalence of the AIDA operon in porcine E. coli isolates, with over 25% of all strains being AIDA positive, and we could demonstrate a significant association of the intact AIDA gene (orfB) with ED-PWD, while defects in orfB were associated with the absence of disease. Although our data hint toward a contribution of AIDA to ED-PWD, further studies will be necessary since the presence of the AIDA genes was also associated with the presence of the Shiga-like toxin and F18 adhesin genes, two reported virulence factors for ED-PWD.

scholarly journals The Repeat-In-Toxin Family Member TosA Mediates Adherence of Uropathogenic Escherichia coli and Survival during Bacteremia

2011 ◽  
Vol 80 (2) ◽  
pp. 493-505 ◽  
Author(s):  
Patrick D. Vigil ◽  
Travis J. Wiles ◽  
Michael D. Engstrom ◽  
Lev Prasov ◽  
Matthew A. Mulvey ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Virulence Factors ◽  
Upper Urinary Tract ◽  
Host Cells ◽  
Content Type ◽  
E Coli ◽  
Wide Range ◽  
Novel Target ◽  
Tract Infections

ABSTRACTUropathogenicEscherichia coli(UPEC) is responsible for the majority of uncomplicated urinary tract infections (UTI) and represents the most common bacterial infection in adults. UPEC utilizes a wide range of virulence factors to colonize the host, including the novel repeat-in-toxin (RTX) protein TosA, which is specifically expressed in the host urinary tract and contributes significantly to the virulence and survival of UPEC.tosA, found in strains within the B2 phylogenetic subgroup ofE. coli, serves as a marker for strains that also contain a large number of well-characterized UPEC virulence factors. The presence oftosAin anE. coliisolate predicts successful colonization of the murine model of ascending UTI, regardless of the source of the isolate. Here, a detailed analysis of the function oftosArevealed that this gene is transcriptionally linked to genes encoding a conserved type 1 secretion system similar to other RTX family members. TosA localized to the cell surface and was found to mediate (i) adherence to host cells derived from the upper urinary tract and (ii) survival in disseminated infections and (iii) to enhance lethality during sepsis (as assessed in two different animal models of infection). An experimental vaccine, using purified TosA, protected vaccinated animals against urosepsis. From this work, it was concluded that TosA belongs to a novel group of RTX proteins that mediate adherence and host damage during UTI and urosepsis and could be a novel target for the development of therapeutics to treat ascending UTIs.

Ability ofEscherichia coliO157:H7 isolates to colonize the intestinal tract of conventional adult CD1 mice is transient

2001 ◽  
Vol 47 (1) ◽  
pp. 91-95 ◽  
Author(s):  
J Wayne Conlan ◽  
Sonia L Bardy ◽  
Rhonda KuoLee ◽  
Ann Webb ◽  
Malcolm B Perry
Keyword(s):  
Escherichia Coli ◽  
Mouse Model ◽  
Intestinal Tract ◽  
Vaccine Development ◽  
Escherichia Coli O157 ◽  
Intestinal Colonization ◽  
E Coli ◽  
Cd1 Mice ◽  
A Current

In an attempt to improve upon a current mouse model of intestinal colonization by Escherichia coli O157:H7 used in this laboratory for vaccine development, nine clinical isolates of the pathogen were screened for their ability to persist in the intestinal tract of conventional adult CD-1 mice. None of the test isolates of E. coli O157:H7 were capable of colonizing these mice for a period of more than two weeks. Most of the isolates appeared to be benign for the experimental host, but one isolate was lethal. This virulence correlated with the ability of the latter isolate to produce large quantities of Shiga-like toxin 2 in vitro.

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