scholarly journals FIMBRIAE AND FLAGELLA MEDIATED SURFACE MOTILITY AND THE EFFECT OF GLUCOSE ON NONPATHOGENIC AND UROPATHOGENIC ESCHERICHIA COLI

2019 ◽  
Author(s):  
Sankalya Ambagaspitiye ◽  
Sushmita Sudarshan ◽  
Jacob Hogins ◽  
Parker McDill ◽  
Nicole J. De Nisco ◽  
...  

ABSTRACTWe characterized the surface motility of nonpathogenic and pathogenic E. coli strains with respect to the appendage requirement, flagella versus fimbriae, and the glucose requirement. Nonpathogenic lab strains exhibited either slow or fast surface movement. The slow strains required type 1 fimbriae for movement, while the fast strains required flagella and had an insertion in the flhDC promoter region. Surface movement of three uropathogenic E. coli (UPEC) strains was fast and required flagella, but these strains did not have an insertion in the flhDC promoter region. We assessed swimming motility as an indicator of flagella synthesis and found that glucose inhibited swimming of the slow nonpathogenic strains but not of the fast nonpathogenic or pathogenic strains. Fimbriae-based surface motility requires glucose, which inhibits cyclic-AMP (cAMP) and flagella synthesis; therefore, we examined whether surface motility required cAMP. The surface motility of a slow, fimbriae-dominant, nonpathogenic strain did not require cAMP, which was expected because fimbriae synthesis does not require cAMP. In contrast, the surface motility of a faster, flagella-dominant, UPEC strain required cAMP, which was unexpected because swarming was unaffected by the presence of glucose. Electron microscopy verified the presence or absence of fimbriae or flagella. In summary, surface motilities of the nonpathogenic and uropathogenic E. coli strains of this study differed in the appendage used and the effects of glucose on flagella synthesis.IMPORTANCEUropathogenic Escherichia coli strains cause 80-90% of community-acquired urinary tract infections, and recurrent urinary tract infections, which can last for years, and often become antibiotic resistant. Urinary tract infections can be associated with intra-vesical lesions extending from localized trigonitis/cystitis to widely distributed pancystitis: motility may be a factor that distinguishes between these infection patterns. Nonpathogenic and uropathogenic E. coli were shown to exhibit fimbriae- and flagella-dependent surface motility, respectively, and the difference was attributed to altered control of flagella synthesis by glucose. Uropathogenic E. coli strains grow more rapidly in urine than nonpathogenic strains, which implies differences in metabolism. Understanding the basis for glucose-insensitive control of flagella-dependent motility could provide insight into uropathogenic E. coli metabolism and virulence.

2020 ◽  
Author(s):  
Sushmita Sudarshan ◽  
Jacob Hogins ◽  
Sankalya Ambagaspitiye ◽  
Philippe Zimmern ◽  
Larry Reitzer

ABSTRACTUropathogenic E. coli (UPEC) is the causative pathogen for most uncomplicated urinary tract infections. Flagellar-mediated motility is essential for virulence and colonization for ascending urinary tract infections. The appendage requirement for surface motility depends on the strain: nonpathogenic E. coli (NPEC) lab strains use pili, NPEC hypermotile derivatives use flagella, and UPEC strains use flagella. E. coli flagella-dependent surface motility had been previously shown to require glucose and amino acids. We examined the nutritional and pathway requirements of the NPEC strain W3110 for pili-dependent surface motility, which have not been previously examined. We then compared these requirements to those for two strains with flagella-dependent surface motility: a variant of W3110, W3110-J1, in which the synthesis of the activator of flagella synthesis has been upregulated and the UPEC strain UTI89. The glucose requirement for W3110 was higher than that for either W3110-J1 or UTI89. The pathways required for motility were also different. W3110, but not UTI89, required the Embden-Meyerhof-Parnas pathway via PfkA; conversely, UTI89, but not W3110, required the Entner-Doudoroff pathway, acetogenesis, and the TCA cycle. Glucose did not control flagella synthesis for W3110-J1 and UTI89. The differing requirements for surface motility are likely to reflect major metabolic differences between strains. The metabolic requirements for UTI89 motility suggest a specific adaptation to the urinary tract environment.IMPORTANCEUrinary tract infections affect over 50% of women and E. coli is the most common uropathogen. Virulence requires both pili and flagella, and both appendages can contribute to surface motility. Previous studies of E. coli surface motility did not consider the appendage requirement and the ability to switch the surface appendage. The nutrient and pathway requirements for surface motility of a non-pathogenic E. coli strain with either pili- or flagella-dependent surface motility and the uropathogen UTI89 were examined. Pili-dependent surface motility required glycolysis, while flagella-dependent motility required the TCA cycle and oxidative phosphorylation and was less dependent on glycolysis. The distinctive nutrient and pathway requirements for UTI89 motility probably result from metabolic adaptations to the urinary tract.


2021 ◽  
Author(s):  
Sushmita Sudarshan ◽  
Jacob Hogins ◽  
Sankalya Ambagaspitiye ◽  
Philippe Zimmern ◽  
Larry Reitzer

Uropathogenic E. coli (UPEC) is the causative pathogen for most uncomplicated urinary tract infections. Motility is likely to contribute to these infections, and E. coli possesses flagella-dependent swimming motility, flagella-dependent surface motility (often called swarming), and the recently observed pili-dependent surface motility. Surface motility has not been extensively studied, but for the strains that have been tested nonpathogenic E. coli (NPEC) lab strains use pili, NPEC hypermotile derivatives of these lab strains use flagella, and UPEC strains use flagella. Using a representative of these three types of strains, we showed differences in the nutritional and pathway requirements for surface motility with respect to the glucose concentration, the glycolytic pathway utilized, acetogenesis, and the TCA cycle. In addition, glucose controlled flagella synthesis for the NPEC strain, but not for the hypermotile NPEC variant or the UPEC strain. The requirements for surface motility are likely to reflect major metabolic differences between strains for the pathways and regulation of energy metabolism. IMPORTANCE Urinary tract infections (UTIs) are one of the most common bacterial infections and are an increasing burden on the healthcare system because of recurrence and antibiotic resistance (1, 2). The most common uropathogen is E. coli (3, 4), which is responsible for about 80-90% of community acquired UTIs and 40-50% of nosocomial acquired UTIs (2). Virulence requires both pili and flagella, and either appendage can contribute to surface motility, although surface motility of uropathogenic E. coli has not been examined. We found different appendage, nutrient and pathway requirements for surface motility of a nonpathogenic E. coli lab strain and a uropathogenic E. coli. We propose that these differences are the result of differences in the pathways and regulation of energy metabolism.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1348
Author(s):  
Lívia Slobodníková ◽  
Barbora Markusková ◽  
Michal Kajsík ◽  
Michal Andrezál ◽  
Marek Straka ◽  
...  

Urinary tract infections (UTIs) are among the events that most frequently need medical intervention. Uropathogenic Escherichia coli are frequently their causative agents and the infections are sometimes complicated by the presence of polyresistant nosocomial strains. Phage therapy is a tool that has good prospects for the treatment of these infections. In the present study, we isolated and characterized two bacteriophages with broad host specificity against a panel of local uropathogenic E. coli strains and combined them into a phage cocktail. According to genome sequencing, these phages were closely related and belonged to the Tequatrovirus genus. The newly isolated phages showed very good activity on a panel of local clinical E. coli strains from urinary tract infections. In the form of a two-phage cocktail, they were active on E. coli strains belonging to phylogroups B2 and D, with relatively lower activity in B1 and no response in phylogroup A. Our study is a preliminary step toward the establishment of a national phage bank containing local, well-characterized phages with therapeutic potential for patients in Slovakia.


mBio ◽  
2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Dana Willner ◽  
Serene Low ◽  
Jason A. Steen ◽  
Narelle George ◽  
Graeme R. Nimmo ◽  
...  

ABSTRACTUrinary tract infections (UTIs) are one of the most commonly acquired bacterial infections in humans, and uropathogenicEscherichia colistrains are responsible for over 80% of all cases. The standard method for identification of uropathogens in clinical laboratories is cultivation, primarily using solid growth media under aerobic conditions, coupled with morphological and biochemical tests of typically a single isolate colony. However, these methods detect only culturable microorganisms, and characterization is phenotypic in nature. Here, we explored the genotypic identity of communities in acute uncomplicated UTIs from 50 individuals by using culture-independent amplicon pyrosequencing and whole-genome and metagenomic shotgun sequencing. Genus-level characterization of the UTI communities was achieved using the 16S rRNA gene (V8 region). Overall UTI community richness was very low in comparison to other human microbiomes. We strain-typedEscherichia-dominated UTIs using amplicon pyrosequencing of the fimbrial adhesin gene,fimH. There were nine highly abundantfimHtypes, and each UTI sample was dominated by a single type. Molecular analysis of the corresponding clinical isolates revealed that in the majority of cases the isolate was representative of the dominant taxon in the community at both the genus and the strain level. Shotgun sequencing was performed on a subset of eightE. coliurine UTI and isolate pairs. The majority of UTI microbial metagenomic sequences mapped to isolate genomes, confirming the results obtained using phylogenetic markers. We conclude that for the majority of acute uncomplicatedE. coli-mediated UTIs, single cultured isolates are diagnostic of the infection.IMPORTANCEIn clinical practice, the diagnosis and treatment of acute uncomplicated urinary tract infection (UTI) are based on analysis of a single bacterial isolate cultured from urine, and it is assumed that this isolate represents the dominant UTI pathogen. However, these methods detect only culturable bacteria, and the existence of multiple pathogens as well as strain diversity within a single infection is not examined. Here, we explored bacteria present in acute uncomplicated UTIs using culture-independent sequence-based methods.Escherichia coliwas the most common organism identified, and analysis ofE. colidominant UTI samples and their paired clinical isolates revealed that in the majority of infections the cultured isolate was representative of the dominant taxon at both the genus and the strain level. Our data demonstrate that in most cases single cultured isolates are diagnostic of UTI and are consistent with the notion of bottlenecks that limit strain diversity during UTI pathogenesis.


Author(s):  
Rachana Kanaujia ◽  
Amit Kumar ◽  
Malay Bajpai

Background: Urinary tract infections (UTIs) are one of the most common infections. For treatment of UTIs, there are limited antibiotics due to increased resistance among uropathogens. Two older antibiotics; Nitrofurantoin and Fosfomycin have become novel oral therapeutic options against uropathogens. Aim of the study was to identify UTI causing micro-organisms and evaluate in-vitro activity of nitrofurantoin and fosfomycin against most common isolated organism (E. coli).Methods: Results of urine samples culture and susceptibility testing over a period of 1 year were analysed and included in this study.Results: Micro-organisms were isolated from 568 urine samples. Most commonly isolated organism was Escherichia coli (40.50%), followed by Klebsiella spp. (20.07%) and Staphylococcus spp. (17.07%). Susceptibility of E. coli to nitrofurantoin and fosfomycin was 91.74% and 65.65% respectively. Conclusion: Good activity of nitrofurantoin and fosfomycin against E. coli indicates that these two drugs are potential therapeutic alternatives for urinary tract infections.


2013 ◽  
Vol 57 (9) ◽  
pp. 4512-4517 ◽  
Author(s):  
Etienne Ruppé ◽  
Brandusa Lixandru ◽  
Radu Cojocaru ◽  
Çağrı Büke ◽  
Elisabeth Paramythiotou ◽  
...  

ABSTRACTExtended-spectrum-beta-lactamase (ESBL)-producingEscherichia coli(ESBLE. coli) strains are of major concern because few antibiotics remain active against these bacteria. We investigated the association between the fecal relative abundance (RA) of ESBL-producingE. coli(ESBL-RA) and the occurrence of ESBLE. coliurinary tract infections (UTIs). The first stool samples passed after suspicion of UTI from 310 women with subsequently confirmedE. coliUTIs were sampled and tested for ESBL-RA by culture on selective agar. Predictive values of ESBL-RA for ESBLE. coliUTI were analyzed for women who were not exposed to antibiotics when the stool was passed. ESBLE. coliisolates were characterized for ESBL type, phylogroup, relatedness, and virulence factors. The prevalence of ESBLE. colifecal carriage was 20.3%, with ESBLE. coliUTIs being present in 12.3% of the women. The mean ESBL-RA (95% confidence interval [CI]) was 13-fold higher in women exposed to antibiotics at the time of sampling than in those not exposed (14.3% [range, 5.6% to 36.9%] versus 1.1% [range, 0.32% to 3.6%], respectively;P< 0.001) and 18-fold higher in women with ESBLE. coliUTI than in those with anotherE. coliUTI (10.0% [range, 0.54% to 100%] versus 0.56% [range, 0.15% to 2.1%[, respectively;P< 0.05). An ESBL-RA of <0.1% was 100% predictive of a non-ESBLE. coliUTI. ESBL type, phylogroup, relatedness, and virulence factors were not found to be associated with ESBL-RA. In conclusion, ESBL-RA was linked to the occurrence of ESBLE. coliUTI in women who were not exposed to antibiotics and who had the same clone ofE. coliin urine samples and fecal samples. Especially, a low ESBL-RA appeared to be associated with a low risk of ESBLE. coliinfection.


2014 ◽  
Vol 82 (4) ◽  
pp. 1572-1578 ◽  
Author(s):  
Karen L. Nielsen ◽  
Pia Dynesen ◽  
Preben Larsen ◽  
Lotte Jakobsen ◽  
Paal S. Andersen ◽  
...  

ABSTRACTCathelicidin (LL-37) and human β-defensin 1 (hBD-1) are important components of the innate defense in the urinary tract. The aim of this study was to characterize whether these peptides are important for developing uncomplicatedEscherichia coliurinary tract infections (UTIs). This was investigated by comparing urinary peptide levels of UTI patients during and after infection to those of controls, as well as characterizing the fecal flora of participants with respect to susceptibility to LL-37 andin vivovirulence. Forty-seven UTI patients and 50 controls who had never had a UTI were included. Participants were otherwise healthy, premenopausal, adult women. LL-37 MIC levels were compared for fecalE. coliclones from patients and controls and were also compared based on phylotypes (A, B1, B2, and D).In vivovirulence was investigated in the murine UTI model by use of selected fecal isolates from patients and controls. On average, UTI patients had significantly more LL-37 in urine during infection than postinfection, and patient LL-37 levels postinfection were significantly lower than those of controls. hBD-1 showed similar urine levels for UTI patients and controls. FecalE. coliisolates from controls had higher LL-37 susceptibility than fecal and UTIE. coliisolates from UTI patients.In vivostudies showed a high level of virulence of fecalE. coliisolates from both patients and controls and showed no difference in virulence correlated with the LL-37 MIC level. The results indicate that the concentration of LL-37 in the urinary tract and low susceptibility to LL-37 may increase the likelihood of UTI in a complex interplay between host and pathogen attributes.


2014 ◽  
Vol 63 (2) ◽  
pp. 229-234 ◽  
Author(s):  
Kamel Adwan ◽  
Naser Jarrar ◽  
Awni Abu-Hijleh ◽  
Ghaleb Adwan ◽  
Elena Awwad

Antibiotic resistance of Escherichia coli isolated from urinary tract infections (UTIs) is increasing worldwide. A total of 41 E. coli isolates were obtained from urine samples from hospitalized patients with a UTI in three hospitals in the northern districts of the West Bank, Palestine during March and June 2011. Resistance rates were: erythromycin (95 %), trimethoprim–sulfamethoxazole (59 %), ciprofloxacin (56 %), gentamicin (27 %), imipenem (22 %), amoxicillin (93 %), amoxicillin–clavulanic acid (32 %), ceftazidime (66 %) and cefotaxime (71 %). No meropenem-resistant isolates were identified in this study. Among the isolates, phylogenetic group B2 was observed in 13 isolates, D in 12 isolates, A in 11 isolates and B1 in five isolates. Thirty-five of the isolates were positive for an extended-spectrum β-lactamase phenotype. Among these isolates, the bla CTX-M gene was detected in 25, and eight harboured the bla TEM gene. None of the isolates contained the bla SHV gene. Transformation experiments indicated that some of the β-lactamase genes (i.e. bla CTX-M and bla TEM) with co-resistance to erythromycin and gentamicin were plasmid encoded and transmissible. Apart from this, enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) revealed that the 41 isolates were genetically diverse and comprised a heterogeneous population with 11 ERIC-PCR profiles at a 60 % similarity level.


2014 ◽  
Vol 8 (07) ◽  
pp. 818-822 ◽  
Author(s):  
Farzaneh Firoozeh ◽  
Mohammad Zibaei ◽  
Younes Soleimani-Asl

Introduction: Plasmid-mediated quinolone resistance, which complicates treatment, has been increasingly identified in Escherichia coli isolates worldwide. The purpose of this study was to identify the plasmid-mediated qnrA and qnrB genes among the quinolone-resistant Escherichia coli isolated from urinary tract infections in Iran. Methodology: A total of 140 Escherichia coli isolates were collected between March and October 2012 from urinary tract infections in Khorram Abad, Iran. All isolates were tested for quinoloe resistance using the disk diffusion method. Also, all quinolone-resistant isolates were screened for the presence of the qnrA and qnrB genes by polymerase chain reaction. Minimum inhibitory concentrations (MICs) of ciprofloxacin for the qnr-positive isolates were determined. Results: One hundred sixteen (82.8%) of 140 Escherichia coli isolates were nalidixic acid-resistant; among them, 14 (12.1%) and 9 (7.8%) were qnrA and qnrB-positive, respectively. Two quinolone-resistant isolates harbored both qnrA and qnrB. Among 63 ciprofloxacin-resistant isolates, 14 (22.2%) and 9 (14.3%) were found to carry qnrA and qnrB genes, respectively. The ciprofloxacin MIC range was 0.25–512 μg/mL for 23 qnr-positive Escherichia coli isolates, 18 of which had MICs values of 4–512 μg/mL. Conclusion: Our study shows that the frequency of plasmid-mediated quinolone resistance genes among E. coli isolates in Iran is high.


2004 ◽  
Vol 72 (8) ◽  
pp. 4570-4578 ◽  
Author(s):  
Robert Blomgran ◽  
Limin Zheng ◽  
Olle Stendahl

ABSTRACT Type 1 fimbriae are the most commonly expressed virulence factor on uropathogenic Escherichia coli. In addition to promoting avid bacterial adherence to the uroepithelium and enabling colonization, type 1 fimbriae recruit neutrophils to the urinary tract as an early inflammatory response. Using clinical isolates of type 1 fimbriated E. coli and an isogenic type 1 fimbria-negative mutant (CN1016) lacking the FimH adhesin, we investigated if these strains could modulate apoptosis in human neutrophils. We found that E. coli expressing type 1 fimbriae interacted with neutrophils in a mannose- and lipopolysaccharide (LPS)-dependent manner, leading to apoptosis which was triggered by the intracellular generation of reactive oxygen species. This induced neutrophil apoptosis was abolished by blocking FimH-mediated attachment, by inhibiting NADPH oxidase activation, or by neutralizing LPS. In contrast, CN1016, which did not adhere to or activate the respiratory burst of neutrophils, delayed the spontaneous apoptosis in an LPS-dependent manner. This delayed apoptosis could be mimicked by adding purified LPS and was also observed by using fimbriated bacteria in the presence of d-mannose. These results suggest that LPS is required for E. coli to exert both pro- and antiapoptotic effects on neutrophils and that the difference in LPS presentation (i.e., with or without fimbriae) determines the outcome. The present study showed that there is a fine-tuned balance between type 1 fimbria-induced and LPS-mediated delay of apoptosis in human neutrophils, in which altered fimbrial expression on uropathogenic E. coli determines the neutrophil survival and the subsequent inflammation during urinary tract infections.


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