scholarly journals degS Is Necessary for Virulence and Is among Extraintestinal Escherichia coli Genes Induced in Murine Peritonitis

2003 ◽  
Vol 71 (6) ◽  
pp. 3088-3096 ◽  
Author(s):  
Peter Redford ◽  
Paula L. Roesch ◽  
Rodney A. Welch
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Luria Bertani ◽  
Broth Culture ◽  
Wild Type ◽  
E Coli ◽  
Virulence Attenuation

ABSTRACT Extraintestinal Escherichia coli strains cause meningitis, sepsis, urinary tract infection, and other infections outside the bowel. We examined here extraintestinal E. coli strain CFT073 by differential fluorescence induction. Pools of CFT073 clones carrying a CFT073 genomic fragment library in a promoterless gfp vector were inoculated intraperitoneally into mice; bacteria were recovered by lavage 6 h later and then subjected to fluorescence-activated cell sorting. Eleven promoters were found to be active in the mouse but not in Luria-Bertani (LB) broth culture. Three are linked to genes for enterobactin, aerobactin, and yersiniabactin. Three others are linked to the metabolic genes metA, gltB, and sucA, and another was linked to iha, a possible adhesin. Three lie before open reading frames of unknown function. One promoter is associated with degS, an inner membrane protease. Mutants of the in vivo-induced loci were tested in competition with the wild type in mouse peritonitis. Of the mutants tested, only CFT073 degS was found to be attenuated in peritoneal and in urinary tract infection, with virulence restored by complementation. CFT073 degS shows growth similar to that of the wild type at 37°C but is impaired at 43°C or in 3% ethanol LB broth at 37°C. Compared to the wild type, the mutant shows similar serum survival, motility, hemolysis, erythrocyte agglutination, and tolerance to oxidative stress. It also has the same lipopolysaccharide appearance on a silver-stained gel. The basis for the virulence attenuation is unclear, but because DegS is needed for σE activity, our findings implicate σE and its regulon in E. coli extraintestinal pathogenesis.

scholarly journals In vitro inhibition of Escherichia coli from women with urinary tract infection by cranberry hydroalcoholic extract

Revista Fitos ◽  
2019 ◽  
Vol 13 (4) ◽  
pp. 278-288
Author(s):  
Mariê Scotegagna Chiavini ◽  
Jane Mary Lafayette Neves Gelinski ◽  
Claudriana Locatelli ◽  
Pâmela Aparecida da Costa ◽  
Vânia Aparecida Vicente
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Direct Action ◽  
E Coli ◽  
Antimicrobial Potential ◽  
Diffusion Assay

The antimicrobial potential of cranberry hydro alcoholic extracts (CrE) was evaluated against Escherichia coli isolated from women with urinary tract infection (UTI). CrE was diluted based on the percentage of proanthocyanidins (PACs) in extract powder for final concentrations: 1.26%; 2.52%; 3.35%, 5.03% and 10.06%. CrE antimicrobial potential was evaluated by disk and well diffusion assays, and by in vitro direct action against E. coli. Antibacterial action was observed for all performed tests: minimal inhibitory concentration (MIC) was 1.26% PACs per disk diffusion assay and 2.52% of PACs by well diffusion assay. The in vitro antimicrobial direct action against E. coli resulted 3.8 Log10 cycles reduction for a concentration of 5.03% of PACs. One of the isolates showed multi resistance to antibiotics. But it was also inhibited more than any of the antibiotic tested in well diffusion assay. Only for concentrations 1.26%, 2.52% and 3.45% the inhibition of Escherichia coli by cranberry extract was dose-dependent, i.e directly proportional to the concentration of PACs. The results indicate a inhibitory action high potential of CrE. However, more in vitro and in vivo analysis can be performed to fix which the best concentration of CrE capable of causing a real beneficial effect on UTI´s.

scholarly journals Iha from an Escherichia coli Urinary Tract Infection Outbreak Clonal Group A Strain Is Expressed In Vivo in the Mouse Urinary Tract and Functions as a Catecholate Siderophore Receptor

2006 ◽  
Vol 74 (6) ◽  
pp. 3427-3436 ◽  
Author(s):  
Simon Léveillé ◽  
Mélissa Caza ◽  
James R. Johnson ◽  
Connie Clabots ◽  
Mourad Sabri ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Growth Promotion ◽  
Clonal Group ◽  
E Coli ◽  
Group A ◽  
K 12

ABSTRACT Virulence factors of pathogenic Escherichia coli belonging to a recently emerged and disseminated clonal group associated with urinary tract infection (UTI), provisionally designated clonal group A (CGA), have not been experimentally investigated. We used a mouse model of ascending UTI with CGA member strain UCB34 in order to identify genes of CGA that contribute to UTI. iha was identified to be expressed by strain UCB34 in the mouse kidney using selective capture of transcribed sequences. iha from strain UCB34 demonstrated a siderophore receptor phenotype when cloned in a catecholate siderophore receptor-negative E. coli K-12 strain, as shown by growth promotion experiments and uptake of 55Fe complexed to enterobactin or its linear 2, 3-dihydroxybenzoylserine (DHBS) siderophore derivatives. Siderophore-mediated growth promotion by Iha was TonB dependent. Growth and iron uptake were more marked with linear DHBS derivatives than with purified enterobactin. The reported phenotype of adherence to epithelial cells conferred by expressing iha from a multicopy cloning vector in a poorly adherent E. coli K-12 host strain was confirmed to be specific to iha, in comparison with other siderophore receptor genes. iha expression was regulated by the ferric uptake regulator Fur and by iron availability, as shown by real-time reverse transcriptase PCR. In a competitive infection experiment using the mouse UTI model, wild-type strain UCB34 significantly outcompeted an isogenic iha null mutant. Iha thus represents a Fur-regulated catecholate siderophore receptor that, uniquely, exhibits an adherence-enhancing phenotype and is the first described urovirulence factor identified in a CGA strain.

scholarly journals Antimicrobial Activity Evaluation of Tebipenem (SPR859), an Orally Available Carbapenem, against a Global Set of Enterobacteriaceae Isolates, Including a Challenge Set of Organisms

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
S. J. Ryan Arends ◽  
Paul R. Rhomberg ◽  
Nicole Cotroneo ◽  
Aileen Rubio ◽  
Robert K. Flamm ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Broth Microdilution ◽  
Wild Type ◽  
Content Type ◽  
E Coli

ABSTRACT The antimicrobial activity of tebipenem and other carbapenem agents were tested in vitro against a set of recent clinical isolates responsible for urinary tract infection (UTI), as well as against a challenge set. Isolates were tested by reference broth microdilution and included Escherichia coli (101 isolates), Klebsiella pneumoniae (208 isolates), and Proteus mirabilis (103 isolates) species. Within each species tested, tebipenem showed equivalent MIC50/90 values to those of meropenem (E. coli MIC50/90, ≤0.015/0.03 mg/liter; K. pneumoniae MIC50/90, 0.03/0.06 mg/liter; and P. mirabilis MIC50/90, 0.06/0.12 mg/liter) and consistently displayed MIC90 values 8-fold lower than imipenem. Tebipenem and meropenem (MIC50, 0.03 mg/liter) showed equivalent MIC50 results against wild-type, AmpC-, and/or extended-spectrum β-lactamase (ESBL)-producing isolates. Tebipenem also displayed MIC50/90 values 4- to 8-fold lower than imipenem against the challenge set. All carbapenem agents were less active (MIC50, ≥8 mg/liter) against isolates carrying carbapenemase genes. These data confirm the in vitro activity of the orally available agent tebipenem against prevalent UTI Enterobacteriaceae species, including those producing ESBLs and/or plasmid AmpC enzymes.

scholarly journals Effect of Inactivation of the Global Oxidative Stress Regulator oxyR on the Colonization Ability of Escherichia coli O1:K1:H7 in a Mouse Model of Ascending Urinary Tract Infection

2006 ◽  
Vol 74 (1) ◽  
pp. 461-468 ◽  
Author(s):  
James R. Johnson ◽  
Connie Clabots ◽  
Henry Rosen
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Wild Type ◽  
In Vitro Susceptibility ◽  
E Coli ◽  
C57bl Mice ◽  
The Impact

ABSTRACT To survive within the host urinary tract, Escherichia coli strains that cause urinary tract infection (UTI) presumably must overcome powerful oxidant stresses, including the oxygen-dependent killing mechanisms of neutrophils. Accordingly, we assessed the global oxygen stress regulator OxyR of Escherichia coli as a possible virulence factor in UTI by determining the impact of oxyR inactivation on experimental urovirulence in CBA/J and C57BL (both wild-type and p47phox−/−) mice. The oxyR and oxyS genes of wild-type E. coli strain Ec1a (O1:K1:H7) were replaced with a kanamycin resistance cassette to produce an oxyRS mutant. During in vitro growth in broth or human urine, the oxyRS mutant exhibited the same log-phase growth rate (broth) and plateau density (broth and urine) as Ec1a, despite its prolonged lag phase (broth) or initial decrease in concentration (urine). The mutant, and oxyRS mutants of other wild-type ExPEC strains, exhibited significantly increased in vitro susceptibility to inhibition by H2O2, which, like the altered growth kinetics observed with oxyRS inactivation, were reversed by restoration of oxyR on a multiple-copy-number plasmid. In CBA/J mice, Ec1a significantly outcompeted its oxyRS mutant (by >1 log10) in urine, bladder, and kidney cultures harvested 48 h after perurethral inoculation of mice, whereas an oxyR-complemented mutant exhibited equal or greater colonizing ability than that of the parent. Although C57BL mice were less susceptible to experimental UTI than CBA/J mice, wild-type and p47phox−/− C57BL mice were similarly susceptible, and the oxyR mutant of Ec1a was similarly attenuated in C57BL mice, regardless of the p47phox genotype, as in CBA/J mice. Within the E. coli Reference collection, 94% of strains were positive for oxyR. These findings fulfill the second and third of Koch's molecular postulates for oxyR as a candidate virulence-facilitating factor in E. coli and indicate that oxyR is a broadly prevalent potential target for future preventive interventions against UTI due to E. coli. They also suggest that neutrophil phagocyte oxidase is not critical for defense against E. coli UTI and that the major oxidative stresses against which OxyR protects E. coli within the host milieu are not phagocyte derived.

scholarly journals Sat, the Secreted Autotransporter Toxin of Uropathogenic Escherichia coli, Is a Vacuolating Cytotoxin for Bladder and Kidney Epithelial Cells

2002 ◽  
Vol 70 (8) ◽  
pp. 4539-4546 ◽  
Author(s):  
Debra M. Guyer ◽  
Suzana Radulovic ◽  
Faye-Ellen Jones ◽  
Harry L. T. Mobley
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Cell Lines ◽  
Kidney Tissue ◽  
Upper Urinary Tract ◽  
Wild Type ◽  
Vacuolating Cytotoxin ◽  
E Coli

ABSTRACT The secreted autotransporter toxin (Sat) of uropathogenic Escherichia coli exhibits cytopathic activity upon incubation with HEp-2 cells. We further investigated the effects of Sat on cell lines more relevant to the urinary tract, namely, those derived from bladder and kidney epithelium. Sat elicited elongation of cells and apparent loosening of cellular junctions upon incubation with Vero kidney cells. Additionally, incubation with Sat triggered significant vacuolation within the cytoplasm of both human bladder (CRL-1749) and kidney (CRL-1573) cell lines. This activity has been associated with only a few other known toxins. Following transurethral infection of CBA mice with a sat mutant, no reduction of CFU in urine, bladder, or kidney tissue was seen compared to that in mice infected with wild-type E. coli CFT073. However, significant histological changes were observed within the kidneys of mice infected with wild-type E. coli CFT073, including dissolution of the glomerular membrane and vacuolation of proximal tubule cells. Such damage was not observed in kidney sections of mice infected with a Sat-deficient mutant. These results indicate that Sat, a vacuolating cytotoxin expressed by uropathogenic E. coli CFT073, elicits defined damage to kidney epithelium during upper urinary tract infection and thus contributes to pathogenesis of urinary tract infection.

scholarly journals Comparison of virulence factors and expression of specific genes between uropathogenic Escherichia coli and avian pathogenic E. coli in a murine urinary tract infection model and a chicken challenge model

Microbiology ◽  
2009 ◽  
Vol 155 (5) ◽  
pp. 1634-1644 ◽  
Author(s):  
Lixiang Zhao ◽  
Song Gao ◽  
Haixia Huan ◽  
Xiaojing Xu ◽  
Xiaoping Zhu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Virulence Genes ◽  
Iron Acquisition ◽  
Infection Model ◽  
Phylogenetic Groups ◽  
E Coli

Avian pathogenic Escherichia coli (APEC) and uropathogenic E. coli (UPEC) establish infections in extraintestinal habitats of different hosts. As the diversity, epidemiological sources and evolutionary origins of extraintestinal pathogenic E. coli (ExPEC) are so far only partially defined, in the present study,100 APEC isolates and 202 UPEC isolates were compared by their content of virulence genes and phylogenetic groups. The two groups showed substantial overlap in terms of their serogroups, phylogenetic groups and virulence genotypes, including their possession of certain genes associated with large transmissible plasmids of APEC. In a chicken challenge model, both UPEC U17 and APEC E058 had similar LD50, demonstrating that UPEC U17 had the potential to cause significant disease in poultry. To gain further information about the similarities between UPEC and APEC, the in vivo expression of 152 specific genes of UPEC U17 and APEC E058 in both a murine urinary tract infection (UTI) model and a chicken challenge model was compared with that of these strains grown statically to exponential phase in rich medium. It was found that in the same model (murine UTI or chicken challenge), various genes of UPEC U17 and APEC E058 showed a similar tendency of expression. Several iron-related genes were upregulated in the UTI model and/or chicken challenge model, indicating that iron acquisition is important for E. coli to survive in blood or the urinary tract. Based on these results, the potential for APEC to act as human UPEC or as a reservoir of virulence genes for UPEC should be considered. Further, this study compared the transcriptional profile of virulence genes among APEC and UPEC in vivo.

scholarly journals Transcriptome of Uropathogenic Escherichia coli during Urinary Tract Infection

2004 ◽  
Vol 72 (11) ◽  
pp. 6373-6381 ◽  
Author(s):  
Jennifer A. Snyder ◽  
Brian J. Haugen ◽  
Eric L. Buckles ◽  
C. Virginia Lockatell ◽  
David E. Johnson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Capsular Polysaccharide ◽  
Iron Acquisition ◽  
Expression Profiles ◽  
Growth State ◽  
E Coli

ABSTRACT A uropathogenic Escherichia coli strain CFT073-specific DNA microarray that includes each open reading frame was used to analyze the transcriptome of CFT073 bacteria isolated directly from the urine of infected CBA/J mice. The in vivo expression profiles were compared to that of E. coli CFT073 grown statically to exponential phase in rich medium, revealing the strategies this pathogen uses in vivo for colonization, growth, and survival in the urinary tract environment. The most highly expressed genes overall in vivo encoded translational machinery, indicating that the bacteria were in a rapid growth state despite specific nutrient limitations. Expression of type 1 fimbriae, a virulence factor involved in adherence, was highly upregulated in vivo. Five iron acquisition systems were all highly upregulated during urinary tract infection, as were genes responsible for capsular polysaccharide and lipopolysaccharide synthesis, drug resistance, and microcin secretion. Surprisingly, other fimbrial genes, such as pap and foc/sfa, and genes involved in motility and chemotaxis were downregulated in vivo. E. coli CFT073 grown in human urine resulted in the upregulation of iron acquisition, capsule, and microcin secretion genes, thus partially mimicking growth in vivo. On the basis of gene expression levels, the urinary tract appears to be nitrogen and iron limiting, of high osmolarity, and of moderate oxygenation. This study represents the first assessment of any E. coli pathotype's transcriptome in vivo and provides specific insights into the mechanisms necessary for urinary tract pathogenesis.

scholarly journals CAPSULE PRODUCTION PATTERN OF UROPATHOGENIC ESCHERICHIA COLI OF URINARY TRACT INFECTION PATIENTS IN KIRKUK HOSPITALS

2020 ◽  
Vol 17 (35) ◽  
pp. 621-627
Author(s):  
May Ali Hussien UMRAN ◽  
Sumaya Najim AL-KHATEEB
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Clinical Manifestations ◽  
Uropathogenic Escherichia Coli ◽  
E Coli ◽  
Intestinal Pathogens ◽  
Production Pattern ◽  
Living Organisms

The bacterium Escherichia coli is one of the best free-living organisms studied in depth. It is a surprisingly diverse species, since some strains of E. coli live in the intestine of animals as harmless commensals, while other distinct genotypes, such as an enteropathogenic or enterohemorrhagic E. coli, for example, cause morbidity and death marked as human intestinal pathogens. The purpose of this study was to develop and validate a PCR assay for a known and suspected uropathogenic E. coli virulence factor (kpsMT) gene region to determine the distribution of the gene and its role in the development of clinical diseases of the urinary system. A total of 25 urine samples were collected from patients with urinary tract infection (UTI) at Azadi and Kirkuk hospitals in the city of Kirkuk, Iraq. Samples of both genders and different ages were collected from patients with suspected urinary tract infection according to the clinical manifestations and symptoms diagnosed by the examining physician. The samples were cultured and positive samples were subjected to the IMViC test to identify E. coli bacteria and subsequently identified using the Vitek 2 compact system. Among 25 samples, 24 (96%) showed positive results for bacterial cultural growth. Of these, 17 (68%) were identified as Escherichia coli. Of the total of 17 isolates, 14 from patients with mild urinary tract infection, and 3 from patients with Urosepsis. The kpsMT gene was present in 14 isolates (82.3%), including 11 (78.5%) isolates from patients with mild urinary tract infection, and 3 (100%) isolates from patients with Urosepsis. It was concluded that Escherichia coli is the most prevalent in urine tract infection samples. Due to the abundance of the kpsMT gene in uropathogenic Escherichia coli (UPEC), this gene plays an important role in developing UTI if it is not treated correctly and quickly; mild cases of UTI can turn into Urosepsis.

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