Uropathogenic Escherichia Coli Research Articles

Synergistic Effects of Pyrrosia lingua Caffeoylquinic Acid Compounds with Levofloxacin Against Uropathogenic Escherichia coli: Insights from Molecular Dynamics Simulations, Antibiofilm, and Antimicrobial Assessments

Urinary tract infections (UTIs), primarily caused by uropathogenic Escherichia coli (UPEC), have high morbidity and recurrence rates. Resistance to levofloxacin hydrochloride (LEV), a commonly used treatment for UTIs, is increasingly problematic, exacerbated by biofilm formation mediated by interactions between cyclic di-GMP (c-di-GMP or CDG) and YcgR. In this study, we identified three caffeoylquinic acid compounds from Pyrrosia lingua—chlorogenic acid (CGA), sibiricose A5 (Si-A5), and 3-O-caffeoylquinic acid methyl ester (CAM)—that target YcgR through molecular docking. Biological assays revealed that combining these compounds with levofloxacin hydrochloride significantly enhanced antibacterial activity against standard UPEC strains in a concentration-dependent manner and clinically isolated UPEC strains. Notably, chlorogenic acid and sibiricose A5, when used with levofloxacin hydrochloride, enhanced intracellular c-di-GMP levels and swimming motility, significantly reduced YcgR gene expression, and effectively inhibited biofilm formation of UPEC at multiple time points. Additionally, molecular dynamics simulations elucidated the strong binding of these compounds to YcgR, underscoring the critical roles of residues, such as Arg118 and Asp145. This research serves as a foundation for tackling antibiotic resistance and developing innovative therapeutics for UTIs.

Purified α-Amylase from Bacillus cereus exhibits antibiofilm and antiquorum sensing activities against uropathogenic Escherichia coli, Downregulating fimH, and papC virulence genes: implications for urinary tract infections

Background and aimPathogenic Escherichia coli is a known harmful microorganism that takes advantage of favorable conditions to cause various infections in healthcare settings, such as bloodstream infections related to catheters, as well as infections in the urinary and respiratory tracts. E. coli utilizes biofilm development as a means to enhance its virulence and pathogenicity. This work aims to investigate the antibiofilm activity of α-amylase enzyme against uropathogenic E. coli (UPEC) and its effect on biofilm-regulatory genes.MethodologyIn this study, we evaluated the antibiofilm activity of α-amylase enzyme by spectrophotometric microtiter plate analysis and confocal laser scanning microscopy. Also, the antibacterial activity of the test enzyme was evaluated by measuring the MIC and MBC levels against UPEC. The quorum-quenching activity of α-amylase enzyme was assessed using a qRT-PCR to evaluate the impact on biofilm-regulatory genes.ResultsBased on our results, purified α-amylase showed MIC and MBC levels ranged between 128 and 512 µg /ml against UPEC isolates using broth microdilution assay. Crystal violet assay revealed MBIC of 128 µg/ml and MBEC of 256 µg/ml for the purified α-amylase. When the biofilm was analyzed by confocal laser scanning microscope, our results showed inhibition of biofilm thickness (56%) and live/dead cell percentages (43/55%). Furthermore, analysis of the effect on the expression of biofilm-encoding genes showed downregulation of both fimH and papC genes by 57 and 25%, respectively, upon treatment of UPEC with ½ of the MIC (64 µg/ml).ConclusionsThe results demonstrate that our purified α-amylase from B. cereus exhibits promising antibiofilm activities against UPEC at both phenotypic as well as genotypic levels. These findings suggest that this enzyme may serve as a natural effective tool for removing bacterial biofilms, potentially offering new therapeutic avenues for treating infections caused by UPEC.

Canine uropathogenic and avian pathogenic Escherichia coli harboring conjugative plasmids exhibit augmented growth and exopolysaccharide production in response to Enterococcus faecalis.

Uropathogenic Escherichia coli (UPEC) and avian pathogenic Escherichia coli (APEC) are extraintestinal pathogenic Escherichia coli (ExPEC) that infect dogs and poultry. These agents occur both as single-species infections and, commonly, in co-infection with Enterococcus faecalis (EF); however, it is unclear how EF co-infections modulate ExPEC virulence. Genetic drivers of interspecies interactions affecting virulence were identified using macrocolony co-culture, chicken embryo co-infection experiments, and whole-genome sequence analysis of ExPEC and EF clinical isolates. Ten of 11 UPEC strains originally co-isolated with EF exhibited a growth advantage when co-cultured with EF on iron-limited, semi-solid media in contrast to growing alone (P < 0.01). Phylogenetic analyses of these UPEC and 18 previously screened APEC indicated the growth-response phenotype was conserved in ExPEC despite strain diversity. When genomes of EF-responsive ExPEC were compared to non-responsive ExPEC genomes, EF-induced growth was associated with siderophore, exopolysaccharide (EPS), and plasmid conjugative transfer genes. Two matched pairs of EF-responsive and non-responsive ExPEC were selected for further characterization by macrocolony proximity and chicken embryo lethality assays. EF-responsive ExPEC produced 5 to 16 times more EPS in proximity to EF and were more lethal to embryos alone and during co-infection with EF compared to non-responsive ExPEC (P < 0.05). A responsive APEC strain cured of its conjugative plasmid lost the enhanced growth and EPS production response to EF. These data demonstrate that ExPEC growth augmentation by EF occurs in UPEC and APEC strains and is linked to conjugative virulence plasmids and EPS production, which are widely conserved ExPEC virulence determinants.

Detection of Uropathogenic Escherichia coli Virulence Factors’ fimH and fliC H7 in Urinary Tract Infections and Their Association with Antibiotics Resistance among Sudanese Children

Background UTIs are one of the most common pathological conditions in both community and hospital settings. A broad spectrum of pathogens causes UTIs, it has been estimated that about 80% to 90% of cases worldwide develop UTI each year. However, the most frequent agent of community-acquired UTI is Uropathogenic Escherichia coli (UPEC), Some of UPEC genes have been associated with disease and antibiotic resistance. The presence of multidrug-resistant UPEC harboring several virulence factors, is a major risk factor for inpatients. This study aimed to detect the presence of virulence factors; fimH and fliC H7 genes and their possible association with antibiotic resistance, to evaluate the relation between virulence factors and antibiotic resistance among UPEC isolated from Sudanese symptomatic children’s patients with UTI, in Khartoum State- Sudan. Methods Sixty-six urine samples from study participants with symptomatic UTIs have been identified by clinician from two hospitals as UPEC using the conventional microbiological tests. All the isolates were subjected to antimicrobial sensitivity test using disk diffusion and polymerase chain reaction (PCR) assay to identify the presence of two putative virulence factors; fimH and fliC H7, and their association with antimicrobial resistance. Results Our results have shown that Amoxcacillin (penicillin group) was consistently the most resistance active (90.9%) of the systemically active antimicrobials, followed by Sulfamethoxazole (89.4%). On the other hand, sensitivity to nitrofurantoin (nitrofuran) was found to be the highest (89.4%). FimH gene has the highest prevalence among E. coli isolates (63.6%), followed by fliC gene (53.0%). A statistically significant association was found between the presence of fimH gene and resistance of E. coli to Polynaphethol with Chi-square p-value = 0.016 and odds ratio =5.353. Another significant association was found with resistance of E. coli to Chloramphenicol (Chi-Square p-value = 0.038, odds ratio = 3.103) and presence of fimH gene, also there was a significant association between the presence of fliC H7 gene and resistance of E. coli to Cephalexin with a (Chi-Square p-value = 0.001 and odds ratio = 5.869) Conclusions The study highlighted the prevalence of UPEC isolates which harbored the virulence factors and their association with antibiotic resistance which possibly cause the urine disease. The outcome of the study may represent targets for improving the regimen used and therapeutics against UPEC in Sudan.

Emergence of Carbapenem-Resistant Uropathogenic Escherichia coli (ST405 and ST167) Strains Carrying blaCTX-M-15, blaNDM-5 and Diverse Virulence Factors in Hospitalized Patients.

Urinary tract infections (UTIs) are common infectious diseases in hospital settings, and they are frequently caused by uropathogenic Escherichia coli (UPEC). The emergence of carbapenem-resistant (Carb-R) E. coli strains poses a significant threat due to their multidrug resistance and virulence. This study aims to characterize the antimicrobial resistance and virulence profiles of Carb-R UPEC strains isolated from hospitalized patients. A total of 1100 urine samples were collected from patients in Lahore and Faisalabad, Pakistan, between May 2023 and April 2024. The samples were processed to isolate and identify E. coli using standard microbiological techniques and VITEK®2, followed by amplification of the uidA gene. Antimicrobial susceptibility was evaluated using the Kirby-Bauer disc diffusion method and broth microdilution. Resistance and virulence genes were detected through PCR and DNA sequencing, and sequence typing was performed using MLST. Among the 118 Carb-R UPEC isolates, resistance was most frequently observed against sulfamethoxazole-trimethoprim (96.6%) and doxycycline (96.6%). All of the isolates remained sensitive to colistin and tigecycline. Sequence types ST405 (35.6%) and ST167 (21.2%) were predominant and carried the blaCTX-M-15 and blaNDM-5 genes. The distribution of virulence genes and a variety of antimicrobial resistance genes (ARGs), conferring resistance to aminoglycosides, fluoroquinolones, tetracyclines, and sulfonamides, were observed as specifically linked to certain sequence types. This study provides insights into the molecular epidemiology of carbapenem-resistant Uropathogenic E. coli (Carb-R UPEC) strains and highlights the presence of globally high-risk E. coli clones exhibiting extensive drug resistance phenotypes in Pakistani hospitals. The findings underscore the urgent need for enhanced surveillance and stringent antibiotic stewardship to manage the spread of these highly resistant and virulent strains within hospital settings.

Distinct Escherichia coli transcriptional profiles in the guts of recurrent UTI sufferers revealed by pangenome hybrid selection

Low-abundance members of microbial communities are difficult to study in their native habitats, including Escherichia coli, a minor but common inhabitant of the gastrointestinal tract, and key opportunistic pathogen of the urinary tract. While multi-omic analyses have detailed interactions between uropathogenic Escherichia coli (UPEC) and the bladder mediating urinary tract infection (UTI), little is known about UPEC in its pre-infection reservoir, the gastrointestinal tract, partly due to its low relative abundance (<1%). To sensitively explore the genomes and transcriptomes of diverse gut E. coli, we develop E. coli PanSelect, which uses probes designed to specifically capture E. coli’s broad pangenome. We demonstrate its ability to enrich diverse E. coli by orders of magnitude, in a mock community and in human stool from a study investigating recurrent UTI (rUTI). Comparisons of transcriptomes between gut E. coli of women with and without history of rUTI suggest rUTI gut E. coli are responding to increased oxygen and nitrate, suggestive of mucosal inflammation, which may have implications for recurrent disease. E. coli PanSelect is well suited for investigations of in vivo E. coli biology in other low-abundance environments, and the framework described here has broad applicability to other diverse, low-abundance organisms.

Molecular characteristics of CTX-M β-lactamase-producing and quinolone-resistant Escherichia coli among deer in a popular tourist spot in Japan.

Introduction. Antimicrobial resistance (AMR) is a growing global concern. Clonal lineages of CTX-M β-lactamase-producing Escherichia coli (CTXE) and quinolone-resistant E. coli (QREC) were disseminated among the deer population in a famous tourist destination (Nara Park; NP) in Japan. Hypothesis/gap statement. The molecular characteristics of CTXE or QREC isolates, which could pose a threat to public health, have not been elucidated. Aim. This study aimed to characterize the genetic traits of CTXE and QREC isolates derived from NP deer and compare them with lineages prevalent worldwide. Methodology. Sixteen CTXE and three QREC isolates recovered from NP deer faeces between 2018 and 2020 were analysed using whole-genome sequencing (WGS). For endemic lineages, phylogenetic trees were constructed against the isolates registered in the EnteroBase database using the core genome SNP scheme. Results. The most prevalent lineage in NP deer was ST3580. Several pandemic lineages, such as sequence type (ST) 38, ST58 and ST117, were included. The QREC lineages prevalent among deer were designated as extra-intestinal pathogenic E. coli or uropathogenic E. coli (UPEC). Thirteen of the 24 antimicrobial resistance genes (ARGs) were considered high-risk ARG families. Chromosomal integration of bla CTX-M-15 was observed in all plasmid-negative isolates. Phylogenetic analysis suggested relationships between NP isolates and isolates sourced from the environment or poultry. Conclusion. ST3580 has a high potential for clonal dissemination. Furthermore, multiple clinically relevant lineages of CTXE and QREC are endemic in NP deer; however, they could be less virulent than isolates belonging to the same lineages, which could cause severe infectious diseases. Further studies are required to investigate the relationship between chromosomal integration of plasmid-encoded genes and the stable propagation of AMR bacteria in wildlife and the environment.

Antibiotic Resistance, Biofilm Formation, and Identification of FimH and FimA Adhesion Genes in Uropathogenic Escherichia Coli (UPEC) Isolated from Patients in Baghdad Province

Urinary tract infections (UTIs) are one of the most common infectious disorders worldwide. The most frequent cause of UTIs is uropathogenic Escherichia coli (UPEC). The current study is designed to assess the resistance of antibiotics, the formation of biofilm, and the detection of adhesion genes in E. coli isolated from patients with UTIs. A hundred and fifty samples were collected from patients with confirmed UTIs in Baghdad province during the period of October 2022 to February 2023. Isolation and identification of E. coli were performed using cultural characteristics, gram staining, and biochemical examination, and the results indicated that 52 (35%) isolates were identified as E. coli. Eleven antibiotic discs were utilized to estimate the sensitivity of E. coli isolates. 98% of isolates were resistant to ampicillin, followed by 75.5% of isolates resistant to both trimethoprim/sulfamethoxazole and fosfomycin, followed by 73.5, 71.4, 67.3, 53.1, and 6.1% of isolates resistant to imipenem, ceftazidime, nitrofurantoin, cefepime, and amikacin. All isolates were sensitive to piperacillin-tazobactam, ciprofloxacin, and aztreonam at 100%, 100%, and 98%, respectively. The microtiter plate method was utilized to estimate the ability of E. coli to form biofilm. The majority of isolates (69.2%; n = 36) were moderate biofilm producers, while 19.2% (n = 10) and 11.5% (n = 6) of isolates were strong and weak biofilm producers, respectively. Polymerase Chain Reactions (PCR) were applied to determine the gene expression level of adhesion genes (fimH and fimA genes). Forty isolates harbored both fimH and fimA genes.

Virulence genes and antibiotic susceptibility patterns of Escherichia coli isolated from nosocomial urinary tract infections in the northwest of Iran during 2022-2023: A cross-sectional study.

Urinary tract infections (UTIs) are prevalent among hospitalized patients, constituting the most frequent health-care infections. Uropathogenic Escherichia coli (UPEC) is leading causative agent of UTIs. The present study was aimed to examine the susceptibility of UPEC isolates obtained from nosocomial cases to antibiotics, as well as their biofilm formation capability and frequency of virulence genes. A total of 100 UPEC isolates were collected from nosocomial UTIs at Imam Reza Hospitals in Tabriz, Iran, spanning from April 2022 to January 2023. The antimicrobial susceptibility patterns were evaluated using the disk diffusion method, along with the detection of broad-spectrum β-lactam enzymes (ESBLs) and carbapenemases. The ability of isolates to form biofilms was assessed using the microtiter-plate method, while the PCR method was employed to identify the presence of virulence genes. The highest resistance was observed toward piperacillin (82%), followed by aztreonam and ciprofloxacin (81%), while the lowest resistance was found against piperacillin/tazobactam (12%) and meropenem (9%). ESBLs were detected in 62% of the isolates. The microtiter-plate results revealed strong, moderate, and weak biofilm formation abilities in 32%, 33%, and 24% of the isolates, respectively. The most prevalent virulence gene was fimA (74%) followed by hlyF (68%), papA (44%), papC (32%), iroN (26%), and cnf (20%). The elevated levels of resistance to multiple antimicrobial agents, coupled with the co-presence of virulence genes and biofilm formation abilities, contribute to the persistence of UPEC-related infections, particularly in hospitalized patients. These findings underscore the necessity of implementing an effective program to control nosocomial UTIs caused by UPEC in the healthcare centers.

Ten-Year Antimicrobial Resistance Trend in Uropathogenic Escherichia coli (UPEC) Isolated from Dogs and Cats Admitted to a Veterinary Teaching Hospital in Italy.

Urinary tract infections (UTIs) are a common occurrence in cats and dogs. Surveillance of antibiotic resistance trends helps in the prudent selection of suitable antimicrobial agents. However, there are limited available data on this matter in Italy. This retrospective study aimed to investigate the trends of antimicrobial resistance in uropathogenic Escherichia coli (UPEC) isolated from cats and dogs over ten years (January 2014 to October 2023). Three hundred thirty-nine UPEC strains were isolated from urine samples submitted to the Veterinary Teaching Hospital of Torino (Italy). Antimicrobial susceptibility testing was conducted for up to 11 classes of antibacterials, categorized into four categories (A, B, C, and D) following the European Medicine Agency guidelines for prudent antimicrobial use in animals. The results reveal a higher resistance towards compounds in categories C and D, while fewer isolates were resistant to antibacterials in categories B and A. Resistance has steadily increased from 2014 to 2019. Starting from 2020, a decline in resistance is evident in all four categories. The reduction is more pronounced for the categories subject to the greatest restrictions under European and national legislation. The change in resistance trend is in line with findings from other European countries and food-production animals in Italy.

Consumption of cranberry and probiotics as a natural remedy for urinary tract infections

Introduction and PurposeUrinary tract infections (UTIs) are a prevalent health issue caused primarily by uropathogenic Escherichia coli (UPEC) and other pathogens, affecting millions annually. These infections encompass lower (cystitis) and upper (pyelonephritis) tract manifestations, presenting with symptoms ranging from dysuria to severe complications like sepsis. Traditional antibiotic treatments, while effective, are increasingly challenged by resistance and adverse effects, necessitating exploration of alternative therapies. Cranberry-derived compounds, particularly proanthocyanidins (PACs), are known for their ability to inhibit bacterial adhesion to uroepithelial cells, a critical step in UTI pathogenesis. Clinical studies suggest that cranberry products may reduce UTI incidence, especially in vulnerable populations such as women and catheterized patients. Probiotics, specifically lactobacilli, contribute to urogenital health by competing with uropathogens for epithelial cell binding sites and producing antimicrobial substances. Emerging research highlights the potential synergistic benefits of combining cranberry extracts with probiotics in UTI prevention strategies. Material and MethodsThis review is based on articles from the PubMed database, covering the years 2004-2023, using keywords: urinary tract infections, cranberry, probiotics, E. Coli, antibiotics ConclusionsCranberry products and probiotics offer promising non-antibiotic approaches for UTI prevention, targeting fundamental aspects of bacterial pathogenesis. While preliminary studies indicate promising outcomes, rigorous clinical trials are essential to validate these combinations and optimize therapeutic protocols. Further research is warranted to identify specific bioactive compounds within cranberries, standardize probiotic formulations, and establish comprehensive guidelines for their clinical use in UTI management.

Imidazolium, pyridinium and pyrazinium based ionic liquids with octyl side chains as potential antibacterial agents against multidrug resistant uropathogenic E. coli

Urinary tract infections (UTIs) are the second most prevalent infectious disease with E. coli being the most common etiological agent behind these infections, affecting more than 150 million people globally each year. In recent decades, the emergence of multi-drug resistant (MDR) pathogens has rapidly escalated. To combat antimicrobial resistance (AMR), it is important to synthesize new biologically effective alternatives like ionic liquids (ILs) to control the bacterial infection and their spread. Ionic liquids are poorly coordinated organic salts characterized by melting points typically below 100 °C. The ability of ILs to form anionic and cationic interactions contributes to their versatile chemical, physical and biological attributes. In the present study, a total of 9 previously chemically synthesized and characterized ILs were used. For exploration of their antibacterial potential against the urinary tract infections (UTIs) caused by MDR Uropathogenic E. coli (UPEC) strains, in vitro and in vivo evaluation of ILs were performed. ILs showed pronounced zone of inhibition (ZOI), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 29.5 mm, 3.81 μM and 5.08 μM by agar disk diffusion and broth micro-dilution methods, respectively. Scanning electron microscopy results depicted substantial morphological changes in UPEC biofilm formation ascertaining antibiofilm potential of tested ILs. Moreover, ILs showed exceptional antioxidant potential depicted by DPPH assay along with low cytotoxic effect toward mammalian cell lines (NB4), red blood cells and whole blood. Furthermore, the gene expression analysis results justified the antibacterial potential of ILs showing down-regulation of fimH, uvrY and up-regulation of csrA gene in UPEC after ILs treatment. In vivo dermal sensitivity assessment also established their non-cytotoxic behavior. In silico analysis validated these results, with the majority of the compounds exhibiting moderate to good absorption.Due to remarkable antibacterial and antioxidant potential and negligible cytoxicity, it could be inferred that ILs could serve as novel antimicrobial alternative agents in the treatment of UTIs.

Evolution of the pheV-tRNA integrated genomic island in Escherichia coli.

Escherichia coli exhibit extensive genetic diversity at the genome level, particularly within their accessory genome. The tRNA integrated genomic islands (GIs), a part of the E. coli accessory genome, play an important role in pathogenicity. However, studies examining the evolution of GIs have been challenging due to their large size, considerable gene content variation and fragmented assembly in draft genomes. Here we examined the evolution of the GI integrated at pheV-tRNA (GI-pheV), with a primary focus on uropathogenic E. coli (UPEC) and the globally disseminated multidrug resistant ST131 clone. We show the gene content of GI-pheV is highly diverse and arranged in a modular configuration, with the P4 integrase encoding gene intP4 the only conserved gene. Despite this diversity, the GI-pheV gene content displayed conserved features among strains from the same pathotype. In ST131, GI-pheV corresponding to the reference strain EC958 (EC958_GI-pheV) was found in ~90% of strains. Phylogenetic analyses suggested that GI-pheV in ST131 has evolved together with the core genome, with the loss/gain of specific modules (or the entire GI) linked to strain specific events. Overall, we show GI-pheV exhibits a dynamic evolutionary pathway, in which modules and genes have evolved through multiple events including insertions, deletions and recombination.

Suppression of virulence factors of uropathogenic Escherichia coli by Trans-resveratrol and design of nanoemulgel

BackgroundDevelopment of multidrug resistance in Uropathogenic Escherichia coli (UPEC) makes treatment of Urinary Tract Infections (UTIs) a major challenge. This study was conducted to investigate the effect of trans-resveratrol (t-RSV) at a subinhibitory concentration (sub-MIC-t-RSV) on phenotypic and genotypic expression of virulence factors of clinical isolates of UPEC and develop a nanoformulation of t-RSV. Fifty-five clinical UPEC strains were investigated for the presence of virulence factors by phenotypic methods and PCR detection of virulence genes. The effect of sub-MIC-t-RSV was studied on the phenotypic and genotypic expression of virulence factors. t-RSV-loaded nanoemulgel formulation was prepared and characterized.ResultsOut of the 55 tested isolates, 50.9% were biofilm producers, 23.6% showed both mannose-sensitive and mannose-resistant hemagglutination, 21.8% were serum-resistant, 18.2% were hemolysin producers, while 36.4% showed cytotoxic effect on HEp-2 cells. A total of 25.5% of the isolates harbor one or more of hly-A, cnf-1 and papC genes, while 54.5% were positive for one or more of fimH, iss and BssS genes. A concentration of 100 µg/mL of t-RSV effectively downregulates the phenotypic and genotypic expression of the virulence factors in positive isolates. A stable t-RSV-nanaoemulgel with droplet size of 180.3 nm and Zetapotential of -46.9 mV was obtained.ConclusionThe study proves the effective role of t-RSV as an antivirulence agent against clinical UPEC isolates in vitro and develops a stable t-RSV-nanoemulgel formulation to be assessed in vivo. The promising antibacterial and antivirulence properties of t-RSV place this natural compound to be a better alternative in the treatment of persistent UTIs.

Isolation and molecular characterization of multi-drug resistant uropathogenic Escherichia coli from urine samples: Insights into urinary tract infection management

Urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) present a significant global health burden. With UPEC responsible for approximately 90 % of UTIs, understanding its mechanisms of virulence and antibiotic resistance is paramount for effective treatment strategies. This study aimed to investigate the prevalence of multi-drug resistant (MDR) E. coli strains in urinary tract infections and to elucidate the molecular mechanisms underlying their resistance. A total of 150 E. coli isolates were obtained from urinary tract infection specimens collected patients at Doctor’s Diagnostic Centre in Kalyan Nagar, Bangalore over four months November 2022 to February 2023. Isolation and screening of pathogenic E. coli were conducted using Eosin Methylene Blue Agar and Nutrient Agar, followed by identification through gram staining and biochemical characterization tests. Antibiotic susceptibility testing was performed using Mueller-Hinton agar and various antibiotic discs. Phenotypic and molecular identification of extended-spectrum beta-lactamase (ESBL) producers were conducted, along with the screening for specific antibiotic resistance genes using polymerase chain reaction (PCR). Of the 150 E. coli isolates, 57.3 % were found to be multi-drug resistant, with all 35 isolates from hospitalized patients exhibiting MDR characteristics. Phenotypic and molecular analyses revealed the presence of ESBL-producing isolates, with the blaCTX-M, blaTEM, and blaSHV genes detected in PCR assays. Plasmid extraction and PCR assays further identified the presence of plasmid-encoded carbapenemase genes (blaOXA-48, blaNDM-1, blaKPC-2), as well as other antibiotic resistance genes including those conferring resistance to fluoroquinolones. The results underscore the alarming prevalence of MDR E. coli strains in urinary tract infections, particularly in hospitalized patients. Molecular characterization revealed the diverse genetic mechanisms contributing to antibiotic resistance, including the presence of ESBLs and plasmid-encoded resistance genes. These findings emphasize the urgent need for surveillance and infection control measures to mitigate the spread of MDR pathogens and the development of alternative therapeutic strategies to combat antibiotic resistance in UTIs.

Estrogen-stimulated uropathogenic E. coli mediate enhanced neutrophil responses

Urinary tract infection (UTI) is one of the most common bacterial infections worldwide and the most common cause is uropathogenic Escherichia coli (UPEC). Current research is mostly focused on how UPEC affects host factors, whereas the effect of host factors on UPEC is less studied. Our previous studies have shown that estrogen alters UPEC virulence. However, the effect of this altered UPEC virulence on neutrophils is unknown. The aim of the present study was to investigate how the altered UPEC virulence mediated by estrogen modulates neutrophil responses. We found that estradiol-stimulated CFT073 increased neutrophil phagocytosis, NETs formation and intracellular ROS production. We observed that the total ROS production from neutrophils was reduced by estradiol-stimulated CFT073. We also found that estradiol-stimulated CFT073 induced less cytotoxicity in neutrophils. Additionally, we found that several cytokines and chemokines like IL-8, IL-1β, CXCL6, MCP-1 and MCP-4 were increased upon estradiol-stimulated CFT073 infection. In conclusion, this study demonstrates that the estrogen-mediated alterations to UPEC virulence modulates neutrophil responses, most likely in a host-beneficial manner.

Incidence and Recurrence of Urinary Tract Infections Caused by Uropathogenic Escherichia coli: A Retrospective Cohort Study.

Urinary tract infections (UTIs) are among the most common bacterial infections, with uropathogenic Escherichia coli (UPEC) as the main etiologic agent of uncomplicated UTIs (uUTIs). The prevalence of uUTis caused by organisms with antimicrobial resistance (AMR) is increasing worldwide, complexifying the disease management and increasing the risk of complications. In efforts to develop new strategies for uUTI prevention, it is imperative to understand factors associated with the occurrence of new episodes. This retrospective cohort study aimed to assess the incidence of uUTIs caused by UPEC (UPEC-uUTIs) or unknown etiology (untested uUTIs) in adults aged ≥18 years receiving care in a San Francisco healthcare system. During 2014-2019, 1087 UPEC-uUTI and 4106 untested uUTI cases were documented, of which 324 (29.8%; 95% confidence interval: 27.1%-32.6%) and 1030 (25.1%; 95% confidence interval: 23.8%-26.4%) were followed by ≥1 new episode of uUTI within 12 months. In the UPEC-uUTI cohort, male gender, diagnosis of diabetes mellitus, and prior uUTI were risk factors for new episodes of uUTI. At the time of first UPEC-uUTI diagnosis, antimicrobial prescriptions were retrieved for 41.1% of cases. When tested, AMR was most frequently reported for trimethoprim/sulfamethoxazole or trimethoprim/sulfamethoxazole prescribed with other antimicrobials. Our study provides important information on the incidence and risk of repeated episodes of uUTIs, as well as on AMR related to them.

Analysing the influence of dapagliflozin on urinary tract infection vulnerability and kidney injury in mice infected with uropathogenic Escherichia coli.

Sodium-glucose co-transporter-2 (SGLT2) inhibitors have revolutionized clinical medicine, but their association with urinary tract infection (UTI) risk remains debated. This study investigates the influence of dapagliflozin on UTI outcomes, focusing on kidney injury. Female non-diabetic C57BL/6J and C3H/HeOuJ mice, along with diabetic db/db mice, were orally administered dapagliflozin (1 mg/kg or 10 mg/kg) for 7 days before transurethral uropathogenic Escherichia coli (UPEC) infection. Mice were killed either 24 h after UTI or after six additional days of dapagliflozin treatment. UPEC titers were enumerated, and kidney histopathology, injury, fibrosis and function were assessed. Vehicle- and dapagliflozin-treated C57BL/6J mice exhibited similar urine and bladder UPEC titers, with minimal kidney burden 24 h after UTI. In C3H/HeOuJ mice, UPEC burden was comparable in vehicle- and 1 mg/kg dapagliflozin-treated groups both 24 h and 7 days after UTI. However, C3H/HeOuJ mice receiving 10 mg/kg dapagliflozin had increased UPEC titers in the urine, bladder and kidneys at both endpoints. Kidney injury and fibrosis markers, as well as kidney function, were similar in vehicle and dapagliflozin groups. In diabetic db/db mice receiving dapagliflozin, UPEC strain UTI89 titers were reduced 7 days after UTI compared to vehicle-treated mice, but no difference in UPEC titers was observed when mice were infected with UPEC strain CFT073. Kidney injury and fibrosis markers and kidney function remained similar across treatment groups. Dapagliflozin does not consistently influence UTI susceptibility and shows limited impact on kidney injury or fibrosis, suggesting SGLT2 inhibitors have minimal effects on UTI-related kidney complications.

Hydroxyproline increases inflammation and Uropathogenic E. coli (UPEC) infection in female rats.

Calcium oxalate (CaOx) kidney stones may be associated with urinary tract infections (UTIs). However, the mechanisms for this association are not well-established. The objective of this study was to investigate the effect of oxalate on immunity and UTI development in vivo. Female Sprague-Dawley rats were fed a control diet for 3 days before continuing this diet or starting a 5% Hydroxy-L-proline diet (HLP; oxalate precursor) for 7 days. Rats were subsequently infected transurethrally with Uropathogenic E. coli (UPEC, a bacterium that causes UTI) and sacrificed 3 days later. Urine, blood, kidney, and bladder samples were collected. Urinary oxalate levels, renal CaOx crystal deposition, inflammatory markers, and the bacterial load were assessed using ion chromatography-mass spectrometry, immunohistochemistry, qRT-PCR, western blotting, enzyme-linked immunosorbent assays, or colony forming unit assays. Animals fed HLP and infected with UPEC had a significant increase in urinary oxalate levels, renal CaOx deposition, pro-inflammatory macrophages, pro-inflammatory cytokines, and bacterial loads compared to animals fed the control diet with UPEC infection. In addition, HLP-fed animals had significantly reduced anti-inflammatory renal macrophages and anti-inflammatory cytokine levels in their plasma, urine, and kidneys. These findings suggest that oxalate may play a novel role in the propagation of UTI development.

Nur77 protects the bladder urothelium from intracellular bacterial infection

Intracellular infections by Gram-negative bacteria are a significant global health threat. The nuclear receptor Nur77 (also called TR3, NGFI-B, or NR4A1) was recently shown to sense cytosolic bacterial lipopolysaccharide (LPS). However, the potential role for Nur77 in controlling intracellular bacterial infection has not been examined. Here we show that Nur77 protects against intracellular infection in the bladder by uropathogenic Escherichia coli (UPEC), the leading cause of urinary tract infections (UTI). Nur77 deficiency in mice promotes the formation of UPEC intracellular bacterial communities (IBCs) in the cells lining the bladder lumen, leading to persistent infection in bladder tissue. Conversely, treatment with a small-molecule Nur77 agonist, cytosporone B, inhibits invasion and enhances the expulsion of UPEC from human urothelial cells in vitro, and significantly reduces UPEC IBC formation and bladder infection in mice. Our findings reveal a new role for Nur77 in control of bacterial infection and suggest that pharmacologic agonism of Nur77 function may represent a promising antibiotic-sparing therapeutic approach for UTI.