Uropathogenic Escherichia Coli Isolates Research Articles

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.

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.

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.

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.

Prevalence, Phenotypic Characterization and Antibiogram of Uro-pathogenic Escherichia coli (UPEC) in Patients attending a Tertiary Hospital in Katsina Metropolis

Study’s Excerpt Investigation of the prevalence and antibiotic resistance of uro-pathogenic Escherichia coli (UPEC) among patients at General Hospital Katsina was carried out. The results revealed a 13.33% prevalence rate and significant multidrug resistance (MDR) among 65% of UPEC isolates. Correlations between age, gender, occupation, and multidrug resistance, with notable resistance to common antibiotics were identified so as to give insights into the management of UPEC-related infections in the region. Full Abstract This study examines the prevalence and antibiotic resistance of uro-pathogenic Escherichia coli (UPEC) among 150 patients at General Hospital Katsina (GHK). The urine samples were cultured on CLED and subsequently sub-cultured on EMB using standard protocols to obtain pure colonies. Gram stain, biochemical, and antibiotic susceptibility tests were carried out on the UPEC isolates using standard methods. Of the 150 urine samples analyzed, 69(46%) yielded growth, with 20(13.33%) UPEC prevalence at GHK. Chi-square revealed a higher UTIs prevalence of (48.89%: X2=24.00) based on age observed in the 31-40 years group. Based on gender, females have a higher UTIs prevalence of (60%: X2=2.00) than males (40%: X2=2.00). Business-inclined individuals showed UTIs prevalence (39.13%: X2= 20.0) higher than other occupations. Remarkable UPEC resistance was observed with AMP, CAZ, CRX, and ERY. UPEC showed high susceptibility to Nitrofurantoin and Imipenem, but 65% of isolates were multidrug resistant. Multiple drug resistant indices (MARI) ranged from 0.3 to 0.9, indicating the existence of high multidrug resistance UPEC in the study population. Pearson correlation indicated a positive correlation between age (r=0.44) and gender (r= 0.797) in relation to multidrug antibiotic resistance. Routine surveillance is recommended.

Distribution of chaperone-usher fimbriae and curli fimbriae among uropathogenic Escherichia coli

BackgroundIn the present study, we aimed to determine the frequency of the csgA, fimH, mrkD, foc, papaGI, papGII and papGIII genes, to provide and to design fimbrial adhesin gene (FAG) patterns and profiles for the isolated uropathogenic Escherichia coli (UPEC) strains.MethodsThe enrollment of 108 positive urine samples was performed during seven months, between January 2022 and July 2022. The UPEC strains were confirmed through the standard microbiological and biochemical tests. The antimicrobial susceptibility test was performed through the Kirby–Bauer disc diffusion method. Molecular screening of FAGs was done through the polymerase chain reaction technology. The statistical analyses including chi square and Fisher’s exact tests were performed to interpret the obtained results in the present study.ResultsAs the main results, the antimicrobial resistance (AMR) patterns,multi- (MDR) and extensively drug-resistance (XDR) patterns and FAG patterns were designed and provided. fimH (93.3%), csgA (90.4%) and papG (37.5%) (papGII (30.8%)) genes were recognized as the top three FAGs, respectively. Moreover, the frequency of csgA-fimH gene profile was identified as the top FAG pattern (46.2%) among the others. The isolates bearing csgA-fimH gene profile were armed with a versatile of phenotypic AMR patterns. In the current study, 27.8%, 69.4% and 1.9% of the UPEC isolates were detected as extended-spectrum ß-lactamases (ESBLs) producers, MDR and XDR strains, respectively.ConclusionsIn conclusion, detection, providing and designing of patterns and profiles in association with FAGs, AMR feature in UPEC strains give us an effective option to have a successful and influential prevention for both of UTIs initiation and AMR feature.

The molecular-genetic characteristics of uropathogenic Escherichia coli isolated from pregnant women with asymptomatic bacteriuria

Introduction. Uropathogenic Escherichia coli (UPEC) are the dominant bacterial pathogens of urinary tract infections (UTIs). UPEC belong to different phylogenetic groups and have many virulence factors, the study of which, in conjuction with the assessment of their relationship with clinical forms of UTI, is necessary for a better understanding of the pathogenesis of UTI and the development of new diagnostic algorithms. Aim: determination of the molecular genetic characteristics of uropathogenic Escherichia coli isolated from pregnant women with asymptomatic bacteriuria. Materials and methods. Clinical isolates of uropathogenic E. coli (n = 70) from pregnant women with asymptomatic bacteriuria were included in the study. The PCR method was used to determine the belonging to phylogenetic groups and detect 15 virulence markers — genes associated with adhesion (fimH, papC, sfa, afa, focG); toxin synthesis (cnf 1, hlyA, sat, vat, usp); siderophores (fyuA, iroN, iuc); capsular antigen (kpsMII). To assess the statistical significance of differences, Fisher's exact test was used. Differences were considered statistically significant at a confidence interval of 95% (p 0.05). Results. Most of the UPEC isolates belonged to phylogroup B2 (51,4%) and were characterized by the detection of all UPEC-associated virulence factors included in this study; genes associated with adhesion (sfa, focG), invasins (ibeA), synthesis of toxins (hlyA, cnf1, vat, usp) and capsule (kpsMII), siderophores (fyuA, iroN, hlyA) were detected significantly more frequently (p 0.05). Two or more virulence determinants were detected in 93% of isolates. Conclusion. The identification of key determinants of virulence and/or a combination of virulence genes can be a prognostic marker for predicting the course of UTI, especially in pregnant women, and will expand diagnostic capabilities taking into account the virulent properties of the uropathogen.

Detection of csg and lux Genes in Biofilm-Forming Uropathogenic Escherichia coli Associated with Urinary Tract Infections

Uropathogenic Escherichia coli (UPEC) is responsible for 80–90% of urinary tract infections (UTI) in the global population. The emergence of the increasing resistance to broad-spectrum antimicrobial agents was due to the ability to form biofilms. Cell surface factors that play a role in biofilm formation include Quorum Sensing (QS) which is encoded by the luxS family gene and curli by two operons, namely the csgBA operon. The purpose of the study is to detect the effects of 2 virulence genes (csgD and luxS) on biofilm-forming UPEC associated with UTI. As many as 76 UPEC isolates were collected from the clinical microbiology laboratories and the biofilm development was analyzed using the crystal violet method on microplate 96 wells. Using PCR assay, the two studied genes (csgD and luxS) were determined to be present in the isolates. UPEC isolates the bacteria-produced biofilms (90.80%) and nonproducers (9.20%). Most UPEC bacteria (97.36%) are known to be positive for csgD and luxS gene, while the others (92.10%) are known to be positive for the luxS gene. The highest proportion of the genes expressed in this study is followed by the presence of a relationship between the ability to produce biofilm and the presence of the genes under investigation, which is followed by all UPEC strains that cause UTI in humans.

Intra-strain colony biofilm heterogeneity in uropathogenic Escherichia coli and the effect of the NlpI lipoprotein

Biofilm growth facilitates the interaction of uropathogenic Escherichia coli (UPEC) with the host environment. The extracellular polymeric substances (EPS) of UPEC biofilms are composed prominently of curli amyloid fiber and cellulose polysaccharide. When the organism is propagated as a colony biofilm on agar media, these macromolecules can generate pronounced macroscopic structures. Moreover, curli/cellulose associate tightly with Congo red, generating a characteristic pink-to-red staining pattern when the media is supplemented with this dye. Among different clinical isolates of UPEC, changes in the abundance of curli/cellulose can lead to diverse colony biofilm phenotypes on a strain-by-strain basis. Nevertheless, for any given isolate, these phenotypes are classically homogenous throughout the colony biofilm. Here, we report that a subset of clinical UPEC isolates display heterogenous ‘peppermint’ colony biofilms, with distinct pale and red subpopulations. Through isolation of these subpopulations and whole genome sequencing, we demonstrate various emergent mutations associated with the phenomenon, including within the gene encoding the outer membrane lipoprotein nlpI. Deletion of nlpI within independent strain-backgrounds increased biofilm rugosity, while its overexpression induced the peppermint phenotype. Upregulation of EPS-associated proteins and transcripts was likewise observed in the absence of nlpI. Overall, these results demonstrate that EPS elaboration in UPEC is impacted by nlpI. More broadly, this phenomenon of intra-strain colony biofilm heterogeneity may be leveraged as a tool to identify additional members within the broad collection of genes that regulate or otherwise affect biofilm formation.

Antimicrobial Resistance in Uropathogenic Escherichia coli Strains Isolated from Relapses from Recurrent Urinary Tract Infections.

Little is known about the characteristics of uropathogenic Escherichia coli (UPEC) associated with recurrent urinary tract infections (RUTIs). The present study aimed to analyze the phenotypic antimicrobial resistance of recurrent UPEC isolates attributable to either relapse or reinfection. A total of 140 E. coli strains were isolated from 70 outpatients with RUTIs. All isolates were analyzed by random amplified polymorphic DNA-polymerase chain reaction to evaluate genetic similarity between the first and second isolates. We found that 64.2% (45/70) of outpatients had a relapse with the primary infecting E. coli strain and 35.7% (25/70) had reinfection with a new E. coli strain. Compared with reinfecting strains, relapse UPEC isolates exhibited much higher antimicrobial resistance; 89% of these isolates were multidrug-resistant and 46.6% were extended-spectrum β-lactamase producers. Our study provides evidence that RUTIs are mainly driven by the persistence of the original strain in the host (relapses) despite appropriate antibiotic treatments, and only RUTIs attributed to relapses seem to favor multidrug resistance in UPEC isolates.

Antibacterial Properties of Mint Nanoemulsion Against Uropathogenic Escherichia coli Carrying Beta-Lactamase Resistance Genes

Background: Uropathogenic Escherichia coli (UPEC) is a significant contributor to urinary tract infections (UTIs). The inappropriate prescription and utilization of antibiotics in treating UTIs have resulted in a rise in antibiotic resistance. The aim of this study was to investigate the antibacterial properties of mint nanoemulsion against beta-lactam-resistant strains of UPEC. Methods: Three hundred fifty urine samples were collected in sterile containers and cultured on eosin-methylene blue agar and blood agar media under sterile conditions. Microbial sensitivity testing was conducted using the standard disk diffusion method. Molecular analysis was performed to identify the blaTEM, blaSHV, and blaCTX genes in the samples. The mint nanoemulsion was produced using the low-energy method of spontaneous emulsion formation and characterized using scanning electron microscopy (SEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR). The antibacterial activity of the mint nanoemulsion against multidrug-resistant (MDR) isolates underwent assessment. Results: One hundred UPEC strains were isolated and identified, showing differing levels of resistance and sensitivity to various antibiotics. Nitrofurantoin exhibited the highest resistance (22%), while amikacin had the lowest resistance (4%). The prevalence of the blaTEM, blaSHV, and blaCTX genes among the UPEC isolates was 93.33%, 100%, and 73.33%, respectively. The mint nanoemulsion demonstrated effective antibacterial activity against resistant isolates, with a minimum inhibitory concentration of 0.2 mg/µL and a minimum bactericidal concentration of 0.3 mg/µL. Conclusion: The resistance of UPEC against conventional antibiotics commonly used to treat UTIs was consistently high and demonstrated an increasing trend over time. This escalating situation could potentially become more severe in the future if the rational consumption of antibiotics is not carefully managed. Nanoemulsions synthesized using mint revealed promising stability and robust antimicrobial properties against UPEC isolates. Consequently, it is evident that these synthesized nanoemulsions represent a viable candidate as effective antimicrobial agents in combating antibiotic resistance in UTI treatment.

Prevalence and Antimicrobial Resistance Pattern of Uropathogenic Escherichia coli at a Tertiary Care Hospital: A Retrospective Study

Background: Uropathogenic Escherichia coli (UPEC) is the most common cause of urinary tract infection in humans including cystitis and pyelonephritis. Antimicrobial resistance (AMR) in UPEC is one of the global public challenges that is due to prevalent use of antibiotics in healthcare setting. Therefore, the purpose of this study is to investigate the frequency and antibiotic resistance pattern of UPEC isolated from patients admitted to Modares Hospital in Saveh, Iran. Methods: In this study, in total 633 isolates were evaluated. UPEC isolates were obtained from patients with urinary tract infection and identified using conventional microbiological protocols. Antibiotic resistance pattern of UPEC against different antibiotic were determined using disk diffusion method. SPSSTM software was used for statistical analysis Results: In this study, the most sample was related to outpatients and the lowest sample was related to the CCU wards. The highest antibiotic resistance showed against cephalothin (63.8%) and nalidixic acid (62.2%) antibiotics. The highest effective antibiotics for the tested UPEC was nitrofurantoin (90.7%) and gentamicin (77.3%). Cephalothin and nalidixic acid in hospitalized patients in ICU and emergency wards, respectively, showed the highest antibiotic resistance. Out of 633 UPEC, the rate of Multi Drug Resistant (MDR) isolates were 343 (54.2%). Conclusion: The result of this study highlighted the role of UPEC as one of the important cause of UTI in individuals. Also, nitrofurantoin then gentamicin are the most effective antibiotics against UPEC infections. Logical prescription of antibiotics and infection control strategies are needed for prevention and control of nosocomial infections especially urinary tract infection.

Evaluation of adhesin genes and risk factors associated with urinary tract infections by drug-resistant uropathogenic Escherichia coli in North of Iran.

Uropathogenic Escherichia coli (UPEC) isolates, have a wide variety of virulence factors to promote colonization and survival in the urinary tract. This study aimed to evaluate adhesin genes, biofilm formation ability, antibiotic resistance profiles of UPEC strains, and the related risk factors in patients with UTIs caused by drug-resistant UPEC. A total of 105 UPEC isolates were evaluated for biofilm formation using 96-well microtiter plates, the presence of adhesin genes by PCR assay and the antimicrobial susceptibility pattern using the disk diffusion method. Demographic and clinical characteristics of patients were investigated to identify predisposing factors for drug-resistant isolates. Out of 105 UPEC isolates, 84.8% were positive for biofilm formation. Biofilm-producing isolates exhibited a significantly higher prevalence of fimH, kpsMTII, csgA, afa/draBC, and pap adhesin genes compared to non-biofilm-producing strains (p < 0.05). The results also revealed that 52.4% of the isolates were ESBL-producing, and 84.8% were multidrug-resistant (MDR). Further analysis of antibiotic susceptibility among ESBL-producing strains showed the highest resistance rates to ampicillin, ciprofloxacin, and trimethoprim-sulfamethoxazole. Conversely, the highest susceptibility, in addition to carbapenems, was observed for fosfomycin, amikacin, cefoxitin, and nitrofurantoin. We identified hypertension as a potential risk factor for infection with ESBL-producing UPEC strains. Our results revealed a significant rate of drug resistance among UPEC isolates obtained from UTIs in our region. This underscores the importance of monitoring the empirical use of antibiotics and identifying specific risk factors in our geographical area to guide the selection of appropriate empirical treatment for UTIs.

Whole genome sequencing of uropathogenic E. coli from Ireland reveals diverse resistance mechanisms and strong correlation with phenotypic (EUCAST) susceptibility testing

Urinary tract infections (UTI) caused by uropathogenic Escherichia coli (UPEC) pose a global health concern. Resistance mechanisms, including genetic mutations in antimicrobial target genes, efflux pumps, and drug deactivating enzymes, hinder clinical treatment. These resistance factors often spread through mobile genetic elements. Molecular techniques like whole genome sequencing (WGS), multilocus sequence typing (MLST), and phylotyping help decode bacterial genomes and categorise resistance genes.In this study, we analysed 57 UPEC isolates from different UTI patients following EUCAST guidelines. A selection of 17 representative strains underwent WGS, phylotyping, MLST, and comparative analysis to connect laboratory susceptibility data with predictive genomics based on key resistance genes and chromosomal mutations in antimicrobial targets.Trimethoprim resistance consistently correlated with dfr genes, with six different alleles detected among the isolates. These dfr genes often coexisted with class 1 integrons, with the most common gene cassette combining dfr and aadA. Furthermore, 52.9% of isolates harboured the blaTem-1 gene, rendering resistance to ampicillin and amoxicillin. Ciprofloxacin-resistant strains exhibited mutations in GyrA, GyrB and ParC, plasmid-mediated quinolone resistance genes (qnrb10), and aac(6′)-Ib-cr5. Nitrofurantoin resistance in one isolate stemmed from a four amino acid deletion in NfsB.These findings illustrate the varied strategies employed by UPEC to resist antibiotics and the correlation between clinical susceptibility testing and molecular determinants. As molecular testing gains prominence in clinical applications, understanding key resistance determinants becomes crucial for accurate susceptibility testing and guiding effective antimicrobial therapy.

Gut microbiome correlates of recurrent urinary tract infection: a longitudinal, multi-center study

Urinary tract infections (UTI) affect approximately 250 million people annually worldwide. Patients often experience a cycle of antimicrobial treatment and recurrent UTI (rUTI) that is thought to be facilitated by a gut reservoir of uropathogenic Escherichia coli (UPEC). 125 patients with UTI caused by an antibiotic-resistant organism (ARO) were enrolled from July 2016 to May 2019 in a longitudinal, multi-center cohort study. Multivariate statistical models were used to assess the relationship between uropathogen colonization and recurrent UTI (rUTI), controlling for clinical characteristics. 644 stool samples and 895 UPEC isolates were interrogated for taxonomic composition, antimicrobial resistance genes, and phenotypic resistance. Cohort UTI gut microbiome profiles were compared against published healthy and UTI reference microbiomes, as well as assessed within-cohort for timepoint- and recurrence-specific differences. Risk of rUTI was not independently associated with clinical characteristics. The UTI gut microbiome was distinct from healthy reference microbiomes in both taxonomic composition and antimicrobial resistance gene (ARG) burden, with 11 differentially abundant taxa at the genus level. rUTI and non-rUTI gut microbiomes in the cohort did not generally differ, but gut microbiomes from urinary tract colonized patients were elevated in E.coli abundance 7-14 days post-antimicrobial treatment. Corresponding UPEC gut isolates from urinary tract colonizing lineages showed elevated phenotypic resistance against 11 of 23 tested drugs compared to non-colonizing lineages. The gut microbiome is implicated in UPEC urinary tract colonization during rUTI, serving as an ARG-enriched reservoir for UPEC. UPEC can asymptomatically colonize the gut and urinary tract, and post-antimicrobial blooms of gut E.coli among urinary tract colonized patients suggest that cross-habitat migration of UPEC is an important mechanism of rUTI. Thus, treatment duration and UPEC populations in both the urinary and gastrointestinal tract should be considered in treating rUTI and developing novel therapeutics. This work was supported in part by awards from the U.S. Centers for Disease Control and Prevention Epicenter Prevention Program (grant U54CK000482; principal investigator, V.J.F.); to J.H.K. from the Longer Life Foundation (an RGA/Washington University partnership), the National Center for Advancing Translational Sciences (grants KL2TR002346 and UL1TR002345), and the National Institute of Allergy and Infectious Diseases (NIAID) (grant K23A1137321) of the National Institutes of Health (NIH); and to G.D. from NIAID (grant R01AI123394) and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (grant R01HD092414) of NIH. R.T.'s research was funded by the Deutsche Forschungsgemeinschaft (DFG; German Research Foundation; grant 402733540). REDCap is Supported by Clinical and Translational Science Award (CTSA) Grant UL1 TR002345 and Siteman Comprehensive Cancer Center and NCI Cancer Center Support Grant P30 CA091842. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.

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

Abstract&#x0D; Background&#x0D; 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.

Comprehensive analysis of multiple cytokines to stratify uropathogenic Escherichia coli pathogenesis in mouse model of urinary tract infection

PurposeUrinary tract infection (UTI) is one of the most common human bacterial infections primarily caused by uropathogenic E. coli (UPEC). Empiric treatment in UTI cause emergence of multidrug resistance and limit treatment options. Understanding UTI at the molecular level with respect to the causative pathogen as well as subsequent host response pose an absolute necessity towards appropriate clinical management. This study aimed to investigate host cytokine response in mouse UTI model with respect to bacterial colonization and associated virulence gene expression upon infection. MethodMouse UTI model was established with two clinical UPEC isolates E. coli NP105 and E. coli P025. UPEC colonization in bladder and kidney was evaluated by bacterial culture (CFU/ml). Histopathology of the tissues were examined by hematoxylin and eosin staining. PCR and real time PCR were used to detect the incidence and expression of respective bacterial genes. Cytokine concentrations in tissues and sera were evaluated using ELISA. GraphPad prism version 8.0.2 was used for statistical interpretation. ResultHighest bacterial colonization was observed on 7th and 9th day post infection (p.i). in bladder and kidney of mouse infected with E. coli P025 and E. coli NP105 respectively with a distinct difference in relative expression of fimH and papC adhesin genes in vivo. IL-1β level in tissues and sera of E. coli NP105 and E. coli P025 infected mouse was significantly different but the IL-17A, GCSF, TGF-β levels were comparable. ConclusionThese findings show a role of IL1β to stratify pathogenicity of UPEC in mouse UTI model.

Biofilm formation and antimicrobial resistance pattern of uropathogenic E. coli ST131 isolated from children with malignant tumors

The multidrug-resistant clone identified as Escherichia coli sequence type 131 (E. coli ST131) has spread world-wide. This study sought to ascertain the frequency and biofilm formation of E. coli ST131 isolated from children with various malignancies. A total of 60 uropathogenic E. coli (UPEC) isolates from children without cancer and 30 UPEC isolates from children with cancer were assessed in this study. The microdilution method was used to investigate the sensitivity of bacteria to antibiotics. The microtiter plate (MTP) approach was used to phenotypically assess biofilm formation. The lasR, pelA, and lecA biofilm-encoding genes were detected by PCR in biofilm-producing isolates of E. coli. Thirty-seven out of 90 E. coli isolates were found to be ST131 (41.1%), with 17 (56.7%) from cancer-affected children and 20 (33.3%) from children without cancer, respectively (P-value = 0.036). The frequency of antimicrobial resistance was higher in ST131 strains were compared to non-ST131 strains and when they were isolated from healthy children vs. those who had cancer. In contrast to non-ST131 isolates, ST131 isolates were more biofilm-producers. There was a significant difference between the percentage of biofilm producers between the 22 (100%) ST131-O16 isolates and the 13 (86.7%) ST131-O25b isolates (P-value = 0.04). Children with cancer are more likely than children without cancer to develop biofilm forming E. coli ST131, the latter having a higher profile of antibiotic resistance. Interestingly, E. coli ST131 isolates from non-cancer patients had higher levels of overall antibiotic resistance and while more E. coli ST131isolates from cancer patients formed biofilms.

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.