Uropathogenic Escherichia Coli Strains Research Articles

Multidrug-resistant Escherichia coli causing canine pyometra and urinary tract infections are genetically related but distinct from those causing prostatic abscesses

Despite extensive characterisation of uropathogenic Escherichia coli (UPEC) causing urinary tract infections (UTIs), the genetic background of non-urinary extraintestinal pathogenic E. coli (ExPEC) in companion animals remains inadequately understood. In this study, we characterised virulence traits of 104 E. coli isolated from canine pyometra (n = 61) and prostatic abscesses (PAs) (n = 38), and bloodstream infections (BSIs) in dogs (n = 2), and cats (n = 3). A stronger association with UPEC of pyometra strains in comparison to PA strains was revealed. Notably, 44 isolates exhibited resistance to third-generation cephalosporins and/or fluoroquinolones, 15 were extended-spectrum ß-lactamase-producers. Twelve multidrug-resistant (MDR) strains, isolated from pyometra (n = 4), PAs (n = 5), and BSIs (n = 3), along with 7 previously characterised UPEC strains from dogs and cats, were sequenced. Genomic characteristics revealed that MDR E. coli associated with UTIs, pyometra, and BSIs belonged to international high-risk E. coli clones, including sequence type (ST) 38, ST131, ST617, ST648, and ST1193. However, PA strains belonged to distinct lineages, including ST12, ST44, ST457, ST744, and ST13037. The coreSNPs, cgMLST, and pan-genome illustrated intra-clonal variations within the same ST from different sources. The high-risk ST131 and ST1193 (phylogroup B2) contained high numbers of ExPEC virulence genes on pathogenicity islands, predominating in pyometra and UTI. Hybrid MDR/virulence IncF multi-replicon plasmids, containing aerobactin genes, were commonly found in non-B2 phylogroups from all sources. These findings offer genomic insights into non-urinary ExPEC, highlighting its potential for invasive infections in pets beyond UTIs, particularly with regards to high-risk global clones.

MV140 Mucosal Vaccine Induces Targeted Immune Response for Enhanced Clearance of Uropathogenic E. coli in Experimental Urinary Tract Infection.

MV140 is an inactivated whole-cell bacterial mucosal vaccine with proven clinical efficacy against recurrent urinary tract infections (UTIs). These infections are primarily caused by uropathogenic E. coli (UPEC) strains, which are unique in their virulence factors and remarkably diverse. MV140 contains a non-UPEC strain, suggesting that it may induce an immune response against different UPEC-induced UTIs in patients. To verify this, we experimentally evaluated the cellular and humoral responses to UTI89, a prototypical UPEC strain, in mice vaccinated with MV140, as well as the degree of protection achieved in a UPEC UTI89 model of acute cystitis. The results show that both cellular (Th1/Th17) and antibody (IgG/IgA) responses to UTI89 were induced in MV140-immunized mice. MV140 vaccination resulted in an early increased clearance of UTI89 viable bacteria in the bladder and urine following transurethral infection. This was accompanied by a highly significant increase in CD4+ T cells in the bladder and an increase in urinary neutrophils. Collectively, our results support that MV140 induces cross-reactive humoral and cellular immune responses and cross-protection against UPEC strains.

Turbidimetric bioassays: A solution to antimicrobial activity detection in asymptomatic bacteriuria isolates against uropathogenic Escherichia coli.

Traditional bacteriocin screening methods often face limitations due to diffusion-related challenges in agar matrices, which can prevent the peptides from reaching their target organism. Turbidimetric techniques offer a solution to these issues, eliminating diffusion-related problems and providing an initial quantification of bacteriocin efficacy in producer organisms. This study involved screening the cell-free supernatant (CFS) from eight uncharacterized asymptomatic bacteriuria (ABU) isolates and Escherichia coli 83972 for antimicrobial activity against clinical uropathogenic E. coli (UPEC) strains using turbidimetric growth methods. ABU isolates exhibiting activity against five or more UPEC strains were further characterized (PUTS 37, PUTS 58, PUTS 59, S-07-4, and SK-106-1). The inhibition of the CFS by proteinase K suggested that the antimicrobial activity was proteinaceous in nature, potentially bacteriocins. The activity of E. coli PUTS 58 and SK-106-1 was enhanced in an artificial urine medium, with both inhibiting all eight UPECs. A putative microcin H47 operon was identified in E. coli SK-106-1, along with a previously identified microcin V and colicin E7 in E. coli PUTS 37 and PUTS 58, respectively. These findings indicate that ABU bacteriocin-producers could serve as viable prophylactics and therapeutics in the face of increasing antibiotic resistance among uropathogens.

Antimicrobial resistance and ESBL production in uropathogenic Escherichia coli: a systematic review and meta-analysis in Ethiopia.

Antimicrobial resistance (AMR) is a serious threat to global health systems. Escherichia coli is a major cause of urinary tract infections (UTIs). Understanding the AMR patterns of uropathogenic E. coli (UPEC) is crucial for effective public health interventions worldwide. This systematic review and meta-analysis aimed to consolidate existing research and provide a comprehensive information on AMR UPEC in Ethiopia. We systematically searched databases such as PubMed, Web of Science, and Science Direct, along with including articles from Google Scholar. Data were extracted into Microsoft Excel and analysed using STATA 17.0. Cohen's kappa was computed to assess reviewer agreement, while the I2 statistic evaluated heterogeneity. Egger's tests were conducted to detect publication bias, and random-effects models were utilized to estimate the pooled resistance, with AMR rates for each antibiotic pooled separately. UPEC showed resistance rates, ranging from 3.64% (95% CI: -4.38% to 11.67%) for amikacin to 85.32% (95% CI: 78.6%-92.04%) for ampicillin. Highest resistance was to ampicillin (85.32%), followed by amoxicillin at 82.52% (95% CI: 74.3%-90.74%), tetracycline at 60.67% (95% CI: 51.53%-69.81%) and trimethoprim/sulfamethoxazole at 57.17% (95% CI: 49.93%-64.42%). Conversely, resistance rates were lower for amikacin at 3.64% and meropenem at 5.26% (95% CI: 2.64%-7.88%). UPEC demonstrated a pooled MDR rate of 79.17% (95% CI: 70.32%-88.01%) and a pooled ESBL production rate of 29.16% (95% CI: 22.36%-38.55%). High levels of AMR were observed in UPEC strains, highlighting a critical public health issue requiring urgent action through robust antimicrobial stewardship and surveillance to preserve effective UTI treatment options.

Gentamicin loaded niosomes against intracellular uropathogenic Escherichia coli strains

Urinary tract infections (UTIs) are the most common bacterial infections and uropathogenic Escherichia coli (UPEC) is the main etiological agent of UTIs. UPEC can persist in bladder cells protected by immunological defenses and antibiotics and intracellular behavior leads to difficulty in eradicating the infection. The aim of this paper is to design, prepare and characterize surfactant-based nanocarriers (niosomes) able to entrap antimicrobial drug and potentially to delivery and release antibiotics into UPEC-infected cells. In order to validate the proposed drug delivery system, gentamicin, was chosen as “active model drug” due to its poor cellular penetration. The niosomes physical–chemical characterization was performed combining different techniques: Dynamic Light Scattering Fluorescence Spectroscopy, Transmission Electron Microscopy. Empty and loaded niosomes were characterized in terms of size, ζ-potential, bilayer features and stability. Moreover, Gentamicin entrapped amount was evaluated, and the release study was also carried out. In addition, the effect of empty and loaded niosomes was studied on the invasion ability of UPEC strains in T24 bladder cell monolayers by Gentamicin Protection Assay and Confocal Microscopy. The observed decrease in UPEC invasion rate leads us to hypothesize a release of antibiotic from niosomes inside the cells. The optimization of the proposed drug delivery system could represent a promising strategy to significatively enhance the internalization of antimicrobial drugs.

ColiSeq: a multiplex amplicon assay that provides strain level resolution of Escherichia coli directly from clinical specimens.

Escherichia coli is a diverse pathogen, causing a range of disease in humans, from self-limiting diarrhea to urinary tract infections (UTIs). Uropathogenic E. coli (UPEC) is the most frequently observed uropathogen in UTIs, a common disease in high-income countries, incurring billions of dollars yearly in treatment costs. Although E. coli is easily grown and identified in the clinical laboratory, genotyping the pathogen is more complicated, yet critical for reducing the incidence of disease. These goals can be achieved through whole-genome sequencing of E. coli isolates, but this approach is relatively slow and typically requires culturing the pathogen in the laboratory. To genotype E. coli rapidly and inexpensively directly from clinical samples, including but not limited to urine, we developed and validated a multiplex amplicon sequencing assay, called ColiSeq. The assay consists of targets designed for E. coli species confirmation, high resolution genotyping, and mixture deconvolution. To demonstrate its utility, we screened the ColiSeq assay against 230 clinical urine samples collected from a hospital system in Flagstaff, Arizona, USA. A limit of detection analysis demonstrated the ability of ColiSeq to identify E. coli at a concentration of ~2 genomic equivalent (GEs)/mL and to generate high-resolution genotyping at a concentration of 1 × 105 GEs/mL. The results of this study suggest that ColiSeq could be a valuable method to understand the source of UPEC strains and guide infection mitigation efforts. As sequence-based diagnostics become accepted in the clinical laboratory, workflows such as ColiSeq will provide actionable information to improve patient outcomes.IMPORTANCEUrinary tract infections (UTIs), caused primarily by Escherichia coli, create an enormous health care burden in the United States and other high-income countries. The early detection of E. coli from clinical samples, including urine, is important to target therapy and prevent further patient complications. Additionally, understanding the source of E. coli exposure will help with future mitigation efforts. In this study, we developed, tested, and validated an amplicon sequencing assay focused on direct detection of E. coli from urine. The resulting sequence data were demonstrated to provide strain level resolution of the pathogen, not only confirming the presence of E. coli, which can focus treatment efforts, but also providing data needed for source attribution and contact tracing. This assay will generate inexpensive, rapid, and reproducible data that can be deployed by public health agencies to track, diagnose, and potentially mitigate future UTIs caused by E. coli.

TusDCB, a sulfur transferase complex involved in tRNA modification, contributes to UPEC pathogenicity

tRNA modifications play a crucial role in ensuring accurate codon recognition and optimizing translation levels. While the significance of these modifications in eukaryotic cells for maintaining cellular homeostasis and physiological functions is well-established, their physiological roles in bacterial cells, particularly in pathogenesis, remain relatively unexplored. The TusDCB protein complex, conserved in γ-proteobacteria like Escherichia coli, is involved in sulfur modification of specific tRNAs. This study focused on the role of TusDCB in the virulence of uropathogenic E. coli (UPEC), a bacterium causing urinary tract infections. The findings indicate that TusDCB is essential for optimal production of UPEC's virulence factors, including type 1 fimbriae and flagellum, impacting the bacterium's ability to aggregate in bladder epithelial cells. Deletion of tusDCB resulted in decreased virulence against urinary tract infection mice. Moreover, mutant TusDCB lacking sulfur transfer activity and tusE- and mnmA mutants revealed the indispensability of TusDCB's sulfur transfer activity for UPEC pathogenicity. The study extends its relevance to highly pathogenic, multidrug-resistant strains, where tusDCB deletion reduced virulence-associated bacterial aggregation. These insights not only deepen our understanding of the interplay between tRNA sulfur modification and bacterial pathogenesis but also highlight TusDCB as a potential therapeutic target against UPEC strains resistant to conventional antimicrobial agents.

A Hemagglutination, serum resistance, cell surface hydrophobicity and ESBL production among uropathogenic Escherichia coli

Abstract
 Background
 Bacteria have adapted themselves with increased pathogenesis and drug resistance mechanisms to overcome host defense systems. Uropathogenic E. coli (UPEC) responsible for symptomatic Urinary tract infections (UTIs) carry diverse virulence factors and extended spectrum beta-lactamase (ESBL) production which play pivotal role in pathogenesis and antibiotic resistance. Objective: The purpose of this study was to determine the phenotypic expression of virulence factors; i.e. Hemagglutination, serum resistance, cell surface hydrophobicity and resistance factor ESBL production among UPEC isolates. Methods: In this prospective study 50 drug resistant UPEC strains were evaluated for hemagglutination by slide method, cell surface hydrophobicity by salt aggregation test, serum resistance by serum bactericidal assay and ESBL detection by double disc synergy test. Results: Among 50 UPEC strains 46 (92%) showed mannose resistant hemagglutination, 48 (96%) were found to be serum resistant, 40 (80%) isolates were positive for cell surface hydrophobicity, while 43 (86%) were ESBL producers. Most of the UPEC that expressed virulence factors were ESBL producers as well. Conclusion: Over all, this study indicated that MDR UPEC isolates have expressed a number of virulence factors with ESBL production, which explains how pathogens have increased their virulence and resistance repertoire resulting in treatment failures.

Enhancing a multi-purpose artificial urine for culture and gene expression studies of uropathogenic Escherichia coli strains.

The main objective of this study was to modify a recently reported multi-purpose artificial urine (MP-AU) for culture and gene expression studies of uropathogenic Escherichia coli (UPEC) strains. We used liquid chromatography mass spectrometry (LC-MS) to identify and adjust the metabolic profile of MP-AU closer to that of pooled human urine (PHU). Modification in this way facilitated growth of UPEC strains with growth rates similar to those obtained in PHU. Transcriptomic analysis of UPEC strains cultured in enhanced artificial urine (enhanced AU) and PHU showed that the gene expression profiles are similar, with <7% of genes differentially expressed between the two conditions. Enhancing an MP-AU with metabolites identified in PHU allows the enhanced AU to be used as a substitute for the culture and in vitro gene expression studies of UPEC strains.

Study on the therapeutic mechanism of HJ granules in a rat model of urinary tract infection caused by Escherichia coli

Ethnopharmacological relevanceUrinary tract infections (UTIs) are globally prevalent infectious diseases, predominantly caused by uropathogenic Escherichia coli (UPEC). The misuse of antibiotics has led to the emergence of several drug-resistant strains. Traditional Chinese Medicine (TCM) has its own advantages in the treatment of UTIs. HJ granules is a herbal formula used for the treatment of UTIs. However, its mechanism of action is not clear. Aim of the studyThe aim of this study was to investigate the therapeutic efficacy and mechanism of action of HJ granules in a rat model of UTI caused by Escherichia coli (E coli) CFT073. Materials and methodsSD rats were selected to establish a rat UTI model by injecting UPEC strain CFT073 into the bladder using the transurethral placement method. HJ granules were administered to rats after modelling and the efficacy of HJ granule was investigated by measuring urinary decanalogue, inflammatory factors in bladder tissue and pathological changes in the bladder after 3d of administration. Expression of sonic hedgehog (SHH), NOD-like receptor thermoprotein domain 3 (NLRP3), apoptosis-associated speck-like protein (ASC) and activation of cysteinyl aspartate specific proteinase-1 (caspase-1) were detected by western blotting and immunofluorescence staining in rat bladder tissue. NLRP3, ASC and caspase-1, a cysteine-containing aspartic protein, were expressed and activated. ResultsThe results showed that infection of rats with UPEC resulted in increased pH and erythrocytes in bladder irrigation fluid; increased expression of IL-1β, IL-6 and SHH and decreased expression of IL-10 in bladder tissue; and significant upregulation of the expression of both SHH and NLRP3 inflammasom and significant activation of NLRP3 inflammasom. HJ granules significantly increased the concentration of IL-10 in the bladder, inhibited the expression of SHH and NLRP3 inflammasom in bladder tissue, and suppressed the activation of NLRP3 inflammasom, thereby reducing inflammatory lesions in bladder tissue. ConclusionHJ granules may improve bladder injury and treat UTIs by inhibiting the expression and activation of NLRP3 inflammasom.

The inner membrane protein YhiM links copper and CpxAR envelope stress responses in uropathogenic E. coli.

Urinary tract infection (UTI) is a ubiquitous infectious condition, and uropathogenic Escherichia coli (UPEC) is the predominant causative agent of UTI. Copper (Cu) is implicated in innate immunity, including against UPEC. Cu is a trace element utilized as a co-factor, but excess Cu is toxic due to mismetalation of non-cognate proteins. E. coli precisely regulates Cu homeostasis via efflux systems. However, Cu import mechanisms into the bacterial cell are not clear. We hypothesized that Cu import defective mutants would exhibit increased resistance to Cu. This hypothesis was tested in a forward genetic screen with transposon (Tn5) insertion mutants in UPEC strain CFT073, and we identified 32 unique Cu-resistant mutants. Transposon and defined mutants lacking yhiM, which encodes a hypothetical inner membrane protein, were more resistant to Cu than parental strain. Loss of YhiM led to decreased cellular Cu content and increased expression of copA, encoding a Cu efflux pump. The CpxAR envelope stress response system was activated in the ΔyhiM mutant as indicated by increased expression of cpxP. Transcription of yhiM was regulated by CueR and CpxR, and the CpxAR system was essential for increased Cu resistance in the ΔyhiM mutant. Importantly, activation of CpxAR system in the ΔyhiM mutant was independent of NlpE, a known activator of this system. YhiM was required for optimal fitness of UPEC in a mouse model of UTI. Our findings demonstrate that YhiM is a critical mediator of Cu homeostasis and links bacterial adaptation to Cu stress with the CpxAR-dependent envelope stress response in UPEC.IMPORTANCEUPEC is a common bacterial infection. Bacterial pathogens are exposed to host-derived Cu during infection, including UTI. Here, we describe detection of genes involved in Cu homeostasis in UPEC. A UPEC mutant lacking YhiM, a membrane protein, exhibited dramatic increase in resistance to Cu. Our study demonstrates YhiM as a nexus between Cu stress and the CpxAR-dependent envelope stress response system. Importantly, our findings establish NlpE-independent activation of CpxAR system during Cu stress in UPEC. Collectively, YhiM emerges as a critical mediator of Cu homeostasis in UPEC and highlights the interlinked nature of bacterial adaptation to survival during Cu and envelope stress.

Molecular characterization of ESBL-producing uropathogenic Escherichia coli isolates among kidney transplant patients: Emergence and spread of B2-ST131 clone type

This study was conducted to identify the distribution of virulence determinants in uropathogenic Escherichia coli (UPEC) isolates obtained from kidney transplant (KTP) and non-transplant patients (non-KTP) with urinary tract infections (UTI). Additionally, the (GTG)5 fingerprinting technique was used to investigate the genetic diversity of Extended-Spectrum B-Lactamase (ESBL)-positive isolates.In this case-control study, 111 urine isolates were obtained from non-KTPs and KTPs, respectively. The presence of genetic markers encoding adhesion proteins, toxins and major E. coli phylogroups was assessed through PCR amplification. Molecular typing of ESBL-positive UPEC strains was performed using (GTG)5 fingerprinting and Multilocus sequence typing (MLST) techniques.Overall, 65 and 46 UPEC isolates were obtained from non-KTPs and KTPs, respectively. Among the studied isolates, traT (85.6%) gene was the most frequently observed virulence gene, followed by kpsMT (49.5%). Using the 80% cut-off point, all the 35 UPEC isolates were classified into four major clusters, namely A, B, C, and D. The majority of the Sequence Type (ST) 131 isolates belonged to cluster A. Additionally, three ST1193 isolates belonged to cluster A and phylogroup B2. Moreover, ST38, ST131 and ST10 were in different cluster.In general, we observed significant differences in the papA, ompT, sat, and vat genes between KTPs and non-KTPs. Furthermore, since all the isolates carried one or more virulence factors (VFs), these findings are concerning in the context of managing UTIs caused by the UPEC strain. Additionally, the distribution of ST and Clonal Complex (CC) among isolates in the main clusters revealed significant differences between MLST and (GTG)5 fingerprinting analysis.

Uropathogenic Escherichia coli wield enterobactin-derived catabolites as siderophores

Uropathogenic Escherichia coli (UPEC) secrete multiple siderophore types to scavenge extracellular iron(III) ions during clinical urinary tract infections, despite the metabolic costs of biosynthesis. Here, we find the siderophore enterobactin (Ent) and its related products to be prominent components of the iron-responsive extracellular metabolome of a model UPEC strain. Using defined Ent biosynthesis and import mutants, we identify lower molecular weight dimeric exometabolites as products of incomplete siderophore catabolism, rather than prematurely released biosynthetic intermediates. In E.coli, iron acquisition from iron(III)-Ent complexes requires intracellular esterases that hydrolyze the siderophore. Although UPEC are equipped to consume the products of completely hydrolyzed Ent, we find that Ent and its derivatives may be incompletely hydrolyzed to yield products with retained siderophore activity. These results are consistent with catabolic inefficiency as means to obtain more than one iron ion per siderophore molecule. This is compatible with an evolved UPEC strategy to maximize the nutritional returns from metabolic investments in siderophore biosynthesis.

Multi-drug resistance pattern and genome-wide SNP detection in levofloxacin-resistant uropathogenic Escherichia coli strains.

Antibiotic treatment is extremely stressful for bacteria and has profound effects on their viability. Such administration induces physiological changes in bacterial cells, with considerable impact on their genome structure that induces mutations throughout the entire genome. This study investigated drug resistance profiles and structural changes in the entire genome of uropathogenic Escherichia coli (UPEC) strains isolated from six adapted clones that had evolved under laboratory conditions. Eight UPEC strains, including two parental strains and six adapted clones, with different fluoroquinolone resistance levels originally isolated from two patients were used. The minimum inhibitory concentration (MIC) of 28 different antibiotics including levofloxacin was determined for each of the eight strains. In addition, the effects of mutations acquired with increased drug resistance in the levofloxacin-resistant strains on expression of genes implicated to be involved in drug resistance were examined. Of the eight UPEC strains used to test the MIC of 28 different antibiotics, two highly fluoroquinolone-resistant strains showed increased MIC in association with many of the antibiotics. As drug resistance increased, some genes acquired mutations, including the transcriptional regulator acrR and DNA-binding transcriptional repressor marR. Two strain groups with genetically different backgrounds (GUC9 and GFCS1) commonly acquired mutations in acrR and marR. Notably, acquired mutations related to efflux pump upregulation also contributed to increases in MIC for various antibiotics other than fluoroquinolone. The present results obtained using strains with artificially acquired drug resistance clarify the underlying mechanism of resistance to fluoroquinolones and other types of antibiotics.

Detection and characterization of potentially hybrid enteroaggregative Escherichia coli (EAEC) strains isolated from urinary tract infection.

Uropathogenic Escherichia coli (UPEC) have the potential to receive the virulence markers of intestinal pathotypes and transform into various important hybrid pathotypes. This study aimed to investigate the frequency and characteristics of hybrid enteroaggregative E. coli (EAEC)/UPEC strains. Out of 202 UPEC strains, nine (4.5%) were detected as hybrid EAEC/UPEC. These strains carried one to four iron uptake systems. Among nine investigated pathogenicity islands (PAIs), PAI IV536, PAI II536, and PAI ICFT073 were found in 9 (100%), 3 (33.3%), and 1 (11.1%) strains, respectively. The chuA and sitA genes were detected in 5 (55.5%) and 3 (33.3%) hybrid strains, respectively. Six hybrid strains were found to be typical extraintestinal pathogenic E. coli (ExPEC) according to their virulence traits. Most of the hybrid strains belonged to the phylogenetic group E (6/9). Among the hybrid strains, seven (7/9) were able to form biofilm and adhere to cells; however, only two strains penetrated into the HeLa cells. Our findings reveal some of the virulence characteristics of hybrid strains that lead to fitness and infection in the urinary tract. These strains, with virulence factors of intestinal and non-intestinal pathotypes, may become emerging pathogens in clinical settings; therefore, further studies are needed to reveal their pathogenicity mechanisms and so that preventive measures can be taken.

Cranberry, but not D-mannose and ibuprofen, prevents against uropathogenic Escherichia coli-induced cell damage and cell death in MDCK cells

IntroductionThe main function of the urinary tract is to form an impermeable barrier against urinary solutes and bacteria. However, this barrier can be compromised by urinary tract infections, most commonly caused by uropathogenic Escherichia coli (UPEC). This can result in damage to the epithelial barrier, leading to decreased epithelial thickness, loss of tight junctions, loss of epithelial integrity, and apoptosis. Due to the rise in antimicrobial resistance, there is worldwide interest in exploring non-antibiotic agents as alternative therapy.MethodsUsing the Madin-Darby canine kidney (MDCK) cell line, a widely accepted epithelial cell model for the urinary tract, and the UPEC strain UTI89, this paper aimed to investigate the impact of UPEC on cell integrity, permeability, and barrier functions, and determine whether cranberry, D-mannose and ibuprofen could counteract the effects induced by UPEC. Furthermore, the study examined the protective potential of these agents against UPEC-induced increase in reactive oxygen species (ROS) production and programmed death-ligand 1 (PD-L1) expression.ResultsThe results demonstrated that UTI89 caused a marked reduction in cell viability and monolayer integrity. Cranberry (3 mg/mL) was protective against these changes. In addition, cranberry exhibited protective effects against UPEC-induced damage to cell barrier integrity, escalation of oxidative stress, and UPEC/TNFα-triggered PD-L1 expression. However, no effect was observed for D-mannose and ibuprofen in alleviating UPEC-induced cell damage and changes in ROS and PD-L1 levels.ConclusionOverall, cranberry, but not D-mannose or ibuprofen, has a protective influence against UPEC associated damage in urinary epithelial cells.

The Efficacy of Silver Nanoparticles in Combating Biofilm Formation by Uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) is prevalent in urinary tract infections (UTIs). UPEC’s biofilm production enables it to invade and persist in the uroepithelium, leading to recurrent UTIs. The biofilm formation is associated with antibiotic resistance. To overcome this resistance, non-conventional compounds must be developed as an alternative to conventional antibiotics. Silver nanoparticles (AgNPs) are significant due to their antibacterial activity against diverse organisms. This study was done to investigate the antibacterial and anti-biofilm effects of AgNPs on UPEC. AgNPs were biosynthesized using Pseudomonas aeruginosa ATCC 27853. AgNPs were characterized using visual inspection and scanning electron microscopy. The Agar well diffusion method was employed to assess the antibacterial activity of AgNPs against UPEC isolates. The study utilized the tissue culture plate method to investigate both the biofilm and anti-biofilm properties of AgNPs. Following incubation, Ps.aeruginosa and silver nitrate (AgNO3) mixture exhibited a colour change from pale yellow to dark brown. The mean size of spherical AgNPs observed under a scanning electron microscope was 24.187 ± 8.019 nm. 130 UPECs were obtained. AgNPs exhibited antibacterial activity at a concentration of 20 µg/ml against all tested UPEC strains. Among UPEC strains that produced biofilms, a significant inhibition of 99.89 ± 0.45% was observed at a higher concentration of 512 µg/ml of AgNPs. Ps.aeruginosa produces nitrate reductase enzyme that can potentially convert AgNO3 to AgNPs. The biosynthesized AgNPs exhibit antibacterial and anti-biofilm activity against all tested UPEC strains.

Recent Data Characterizing the Prevalence and Resistance Patterns of FimH-producing Uropathogenic Escherichia coli Isolated from Patients with Urinary Tract Infections in North Lebanon

Background: The adhesin gene (FimH) of uropathogenic Escherichia coli (UPEC) plays a critical role in mediating the first contact of UPEC bacterial strains with uroepithelial cells, leading to colonization and invasion of host cells. Objectives: This study aimed to determine the prevalence of FimH in UPEC strains isolated from patients with urinary tract infections (UTIs) in North Lebanon and characterize the resistance profile of UPEC isolates. Methods: A total of 881 urine samples were collected from UTI-symptomatic patients admitted to different hospitals and laboratories in North Lebanon. Seventy UPEC isolates were identified and transferred to the Biomedical Laboratory of Beirut Arab University (BAU) for further analysis. All UPEC isolates were subjected to antimicrobial susceptibility testing, phenotypic assays for ESBL detection, and PCR to detect the FimH gene. Results: The prevalence of UTIs reached 42% (370/881), with UPEC representing 19% (70/370) of the detected uropathogens. The highest and the lowest resistance among UPEC isolates were reported against Ampicillin (80%; 56/70) and carbapenem (0%; 0/70), respectively. A high prevalence of MDR (68%; 48/70) and ESBL (64%; 45/70) was reported. Molecular analysis revealed that most of the tested UPEC (98.6%; 69/70) harbored the FimH gene. A significant correlation was found between FimH and the antimicrobial resistance properties of UPEC (P &lt; 0.05). Conclusions: This study highlighted the high prevalence of the FimH adhesin gene among UPEC isolates, revealing its crucial role in enhancing the resistance of these bacteria to antimicrobial agents.

Immunoinformatics aided designing of a next generation poly-epitope vaccine against uropathogenic Escherichia coli to combat urinary tract infections

Urinary tract infections (UTIs) are the second most prevalent bacterial infections and uropathogenic Escherichia coli (UPEC) stands among the primary causative agents of UTIs. The usage of antibiotics is the routine therapy being used in various countries to treat UTIs but becoming ineffective because of increasing antibiotic resistance among UPEC strains. Thus, there must be the development of some alternative treatment strategies such as vaccine development against UPEC. In the following study, pan-genomics along with reverse vaccinology approaches is used under the framework of bioinformatics for the identification of core putative vaccine candidates, employing 307 UPEC genomes (complete and draft), available publicly. A total of nine T-cell epitopes (derived from B-cells) of both MHC classes (I and II), were prioritized among three potential protein candidates. These epitopes were then docked together by using linkers (GPGPG and AAY) and an adjuvant (Cholera Toxin B) to form a poly-valent vaccine construct. The chimeric vaccine construct was undergone by molecular modelling, further refinement and energy minimization. We predicted positive results of the vaccine construct in immune simulations with significantly high levels of immune cells. The protein-protein docking analysis of vaccine construct with toll-like receptors predicted efficient binding, which was further validated by molecular dynamics simulation of vaccine construct with TLR-2 and TLR-4 at 120 ns, resulting in stable complexes’ conformation throughout the simulation run. Overall, the vaccine construct demonstrated positive antigenic response. In future, this chimeric vaccine construct or the identified epitopes could be experimentally validated for the development of UPEC vaccines against UTIs. Communicated by Ramaswamy H. Sarma

A new killing assay with the Caenorhabditis elegans PX627 mutant to assess the virulence of uropathogenic Escherichia coli strains

The nematode Caenorhabditis elegans (C. elegans) is a prime invertebrate host model for studying uropathogenic Escherichia coli (UPEC) pathogenesis. The aim of this work was to develop a new C. elegans killing assay based on feeding bacteria by the nematode throughout its life from the egg. With this model, the lifespan of C. elegans rrf-3, temperature-sterile, mutant, and PX627, auxin-inducible infertile, mutant fed UPEC strains, was compared. The behavior of three clinical UPEC strains and the non-pathogenic Escherichia coli OP50 strain was analyzed. Survival curves were generated by the Kaplan–Meier method and compared by the log-rank test over 10 days of follow-up. There was no significant difference between the survival curves obtained with each of the two C. elegans mutants (PX627 and rrf-3) fed with each of the strains of E. coli (OP50, G1722, G1473 or ER41). The UPEC strains were classified according to their virulence in vivo in the C. elegans PX627 mutant. The most virulent strain was ER41 which harbored the virulence genes fimA, papC and hlyA, expressed hemolysis in vitro and showed no antibiotic resistance. The least virulent strain was G1722 which only harbored the two adhesion factor genes, was not hemolytic and was resistant to multiple antibiotics. The C. elegans PX627 mutant fed with UPEC bacteria from the egg stage is a simple and inexpensive invertebrate animal model for assessing the in vivo virulence of different strains. The early exposure of C. elegans to pathogenic bacteria at the egg stage, without the need to change the incubation temperature, is an advantage over previously described C. elegans killing assays.