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 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 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 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.

scholarly journals Evaluation of ESBL (Extended Spectrum Beta-Lactamase) Producing Escherichia Coli Isolated from Patients with Urinary Tract Infection by Phenotypic and Genotypic Methods

2020 ◽  
Author(s):  
Mohammad Hasan Namaei ◽  
Hengameh Hamzei ◽  
Marzie Moghanni ◽  
Azadeh Ebrahimzadeh
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Antibiotic Use ◽  
M Gene ◽  
Esbl Producer ◽  
Accurate Identification ◽  
E Coli ◽  
Tract Infections

Abstract Background: Urinary Tract Infection (UTI) is the most common bacterial infection in the world. E. coli is the predominant Pathogen. This study evaluates the prevalence of ESBL in E. colis isolated from patients with urinary tract infections with phenotypic and genotypic methods.Methods: This descriptive-analytical study was done on 155 isolates of E. coli isolated from patients with urinary tract infection who had received the study consent. After accurate identification of E. coli strains. ESBL production for Escherichia coli isolates which are resistant to ceftriaxone or ceftazidime was evaluated by CDT method. TEM, SHV and CTX-M genes were identified by PCR.Results: The results showed that 30 strains from 155 strains of E. coli had ESBL. Strains of ESBL producer were more in males was lower in educated persons. 38.9% of ESBL producer had antibiotic use, 29.9% -producing Escherichia hospitalization and 31.6% uti history. The highest level of drug allergy in the ESBL was related to nitrofurantoin, and the highest resistance was related to cefazolin, co-trimoxazole. The CTX-M and the CTX-M15 gene were found in 92.7% and 57.1% of cases, respectively; also the SHV and TEM genes were not found in any of ESBL-producing Escherichia coli strains. Most therapeutic response in patients was related to cefexime, ciprofloxacin and nitrofurantoin 27.4%, 26% 21.9%, respectively.Conclusion: This study showed that the history of antibiotic use, hospitalization, uti related to increase of ESBL-producing in E. coli isolates., the CTMX-M gene is the most common gene in ESBL-producing E. coli strains.

Outcome of community-onset ESBL-producing Escherichia coli and Klebsiella pneumoniae bacteraemia and urinary tract infection: a population-based cohort study in Denmark

2020 ◽  
Vol 75 (12) ◽  
pp. 3656-3664
Author(s):  
Rasmus Richelsen ◽  
Jesper Smit ◽  
Henrik Carl Schønheyder ◽  
Pavithra Laxsen Anru ◽  
Belen Gutiérrez-Gutiérrez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Cohort Study ◽  
Urinary Tract ◽  
Tract Infection ◽  
Klebsiella Pneumoniae ◽  
Population Based ◽  
Esbl Production ◽  
E Coli ◽  
Community Onset

Abstract Objectives To assess the impact of ESBL production on mortality and length of hospital stay (LOS) of community-onset infections due to Escherichia coli or Klebsiella pneumoniae. Methods A population-based cohort study including all adult patients hospitalized with a first-time community-onset E. coli or K. pneumoniae bacteraemia or urinary tract infection in the North Denmark Region between 2007 and 2017. For each bacterial agent, we computed 1 year Kaplan–Meier survival curves and cumulative incidence functions of LOS, and by use of Cox proportional hazard regression we computed HRs as estimates of 30 day and 1 year mortality rate ratios (MRRs) and LOS among patients with and without ESBL-producing infections. Results We included 24 518 cases (among 22350 unique patients), of whom 1018 (4.2%) were infected by an ESBL-producing bacterium. The 30 day cumulative mortality and adjusted MRR (aMRR) in patients with and without ESBL-producing isolates was as follows: E. coli bacteraemia (n = 3831), 15.8% versus 14.0%, aMRR = 1.01 (95% CI = 0.70–1.45); E. coli urinary tract infection (n = 17151), 9.5% versus 8.7%, aMRR = 0.97 (95% CI = 0.75–1.26); K. pneumoniae bacteraemia (n = 734), 0% versus 17.2%, aMRR = not applicable; and K. pneumoniae urinary tract infection (n = 2802), 13.8% versus 10.7%, aMRR = 1.13 (95% CI = 0.73–1.75). The 1 year aMRR remained roughly unchanged. ESBL-producing E. coli bacteraemia was associated with an increased LOS compared with non-ESBL production. Conclusions ESBL production was not associated with an increased short- or long-term mortality in community-onset infections due to E. coli or K. pneumoniae, yet ESBL-producing E. coli bacteraemia was associated with an increased LOS.

scholarly journals In-Vitro Biofilm Formation and Antimicrobial Resistance of Escherichia coli in Diabetic and Nondiabetic Patients

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Sunayana Raya ◽  
Ankit Belbase ◽  
Laxmi Dhakal ◽  
Krishna Govinda Prajapati ◽  
Reena Baidya ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Diabetic Patients ◽  
Microtitre Plate ◽  
Plate Method ◽  
E Coli ◽  
Biofilm Production

Background. Diabetic patients are more susceptible to urinary tract infection compared to nondiabetic patients, Escherichia coli being the most common uropathogen causing UTI. Unreasonable and incorrect antibiotic prescription for UTI in these patients may induce the development of antibiotic-resistant urinary pathogens resulting in delayed recovery and longer hospitalization. In addition to these, biofilm forming capacity of the pathogen may worsen the problem. The main aim of this cross-sectional study (conducted from March to September 2015) is to detect the biofilm forming capacity of UTI causing micro-organisms and compare the antibiotic resistance pattern of Escherichia coli, the most common cause of UTI, which will help the physician in choosing the best antibiotic. Method. Total of 1,099 clean-catch mid stream urine (CCMSU) was processed by standard microbiological technique; 182 were from the diabetic group and 917 nondiabetic. Following identification, all isolates were subjected to antibiotic susceptibility testing using modified Kirby-Bauer disc diffusion method. In-vitro biofilm forming capacity of the isolates were detected by Microtitre plate method. The data were analyzed using SPSS software 16. Result. Urinary tract infection was found to be significantly higher in diabetic patients (42.9%) compared to nondiabetic patients (17.4%) with Escherichia coli as the most common uropathogen in both diabetic and nondiabetic groups. Similarly, UTI was more common in elderly population (29.5%). Imipenem, nitrofurantoin and amikacin were found to be the most effective drug for uropathogenic E. coli in both diabetic and nondiabetic patients, whereas amoxicillin, ciprofloxacin, and cotrimoxazole were least effective. Of the total bacterial isolates, 43.3% showed positive results for in-vitro biofilm production by the Microtitre plate method. A significantly higher resistance rate was observed among biofilm producing E. coli for quinolones, cotrimoxazole, and third generation cephalosporin ceftriaxone. Most of the biofilm producers (79.5%) were found to be MDR (p-value 0.015). Conclusion. Elderly populations with diabetes are at a higher risk of UTI. Higher biofilm production and resistance to in-use antimicrobial agents in this study render its inefficacy for empirical treatment and point out the importance of biofilm screening to ensure the effective management of infection.

scholarly journals Uropathogenic Escherichia coli-Induced Inflammation Alters Mouse Urinary Bladder Contraction via an Interleukin-6-Activated Inducible Nitric Oxide Synthase-Related Pathway

2009 ◽  
Vol 77 (8) ◽  
pp. 3312-3319 ◽  
Author(s):  
Te I. Weng ◽  
Hsiao Yi Wu ◽  
Pei Ying Lin ◽  
Shing Hwa Liu
Keyword(s):  
Nitric Oxide ◽  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Urinary Bladder ◽  
Tract Infection ◽  
Interleukin 6 ◽  
Electrical Field Stimulation ◽  
E Coli

ABSTRACT Escherichia coli is the most common cause of urinary tract infection. Elevated blood and urine interleukin-6 (IL-6) levels have been shown in inflammatory urinary tract diseases. The role of IL-6 in mediating the urodynamic dysfunction in response to E. coli-induced urinary tract infection has not yet been fully elucidated. In this study, we investigated the role of IL-6 in the nitric oxide (NO)-triggered alteration of contractile responses in the urinary bladder under an E. coli-induced inflammatory condition. The electrical field stimulation (EFS)-evoked contractions of the isolated detrusor strips, and immunoblotting for detecting protein expression in the bladders was measured short term (1 h) or long term (6 or 24 h) after intraperitoneal injection of E. coli endotoxin (lipopolysaccharide [LPS]) or intravesical instillation of human pyelonephritogenic E. coli-J96 (O4:K6) strain or LPS into mice. IL-6 and NO productions were increased in the urinary bladders of mice 1 to 24 h after LPS or E. coli-J96 treatment. Inducible NO synthase (iNOS) expression and protein kinase C (PKC) activation and EFS-evoked detrusor contractions were increased in the bladders at 6 h after LPS or E. coli-J96 treatment, which could be reversed by anti-IL-6 antibody and iNOS inhibitor aminoguanidine. At 1 h after LPS administration, bladder NO generation, endothelial NOS expression, and EFS-evoked detrusor contractions were effectively increased, whereas anti-IL-6 antibody could not reverse these LPS-induced responses. These results indicate that IL-6 may play an important role in the iNOS/NO-triggered PKC-activated contractile response in urinary bladder during E. coli or LPS-induced inflammation.

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