The ARESC study: an international survey on the antimicrobial resistance of pathogens involved in uncomplicated urinary tract infections

Identification of a copper-responsive small molecule inhibitor of uropathogenic Escherichia coli

Urinary tract infections (UTIs) are a major global health problem and are caused predominantly by uropathogenic Escherichia coli (UPEC). UTIs are a leading cause of prescription antimicrobial use. Incessant increase in antimicrobial resistance in UPEC and other uropathogens poses a serious threat to the current treatment practices. Copper is an effector of nutritional immunity that impedes the growth of pathogens during infection. We hypothesized that copper would augment the toxicity of select small molecules against bacterial pathogens. We conducted a small molecule screening campaign with a library of 51,098 molecules to detect hits that inhibit a UPEC ΔtolC mutant in a copper-dependent manner. A molecule, denoted as E. coli inhibitor or ECIN, was identified as a copper-responsive inhibitor of wild-type UPEC strains. Our gene expression and metal content analysis results demonstrate that ECIN works in concert with copper to exacerbate Cu toxicity in UPEC. ECIN has a broad spectrum of activity against pathogens of medical and veterinary significance including Acinetobacter baumannii, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus. Subinhibitory levels of ECIN eliminate UPEC biofilm formation. Transcriptome analysis of UPEC treated with ECIN reveals induction of multiple stress response systems. Furthermore, we demonstrate that L-cysteine rescues the growth of UPEC exposed to ECIN. In summary, we report the identification and characterization of a novel copper-responsive small molecule inhibitor of UPEC.IMPORTANCEUrinary tract infection (UTI) is a ubiquitous infectious condition affecting millions of people annually. Uropathogenic Escherichia coli (UPEC) is the predominant etiological agent of UTI. However, UTIs are becoming increasingly difficult to resolve with antimicrobials due to increased antimicrobial resistance in UPEC and other uropathogens. Here, we report the identification and characterization of a novel copper-responsive small molecule inhibitor of UPEC. In addition to E. coli, this small molecule also inhibits pathogens of medical and veterinary significance including Acinetobacter baumannii, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus.

Review of the In Vitro Microbiological Activity of Mecillinam Against Common Uropathogens in Uncomplicated Urinary Tract Infection: Focus on Resistant Pathogens

Antimicrobial resistance in uropathogens commonly causing urinary tract infections (UTIs) is a growing problem internationally. Pivmecillinam, the oral prodrug of mecillinam, has been used for over 40 years, primarily in Northern Europe and Canada. It is recommended in several countries as a first-line agent for the treatment of uncomplicated UTIs (uUTIs) and is now approved in the United States. We performed a structured literature search to review the available evidence on susceptibility of common uUTI-causing uropathogens to mecillinam. Among 38 studies included in this literature review, susceptibility rates for Escherichia coli to mecillinam-including resistant phenotypes such as extended-spectrum β-lactamase-producing E. coli-exceed 90% in most studies. High rates of susceptibility were also reported among many other uropathogens including Klebsiella spp., Enterobacter spp., and Citrobacter spp. In the current prescribing climate within the United States, pivmecillinam represents a viable first-line treatment option for patients with uUTI.

Urinary calprotectin as a diagnostic tool for detecting significant bacteriuria

Pyuria in dipstick examination serves as the most widespread screening tool for urinary tract infections (UTI). The absence of pyuria, however, does not exclude UTI. We investigated the diagnostic value of urinary calprotectin, a mediator protein of the innate immune system, which is released by leukocytes, for the detection of UTI and compared it with dipstick pyuria. Since even low numbers of leukocytes in the urine significantly increase urinary calprotectin concentrations, calprotectin might be a more sensitive marker than pyuria detected by dipstick. All 162 patients were prospectively included and underwent a urine dipstick, urine culture, quantification of proteinuria and determination of calprotectin in the urine. Urinary calprotectin was determined using an enzyme-linked immunosorbent assay (ELISA). UTI was defined as urine cultures with detection of one or a maximum of two uropathogenic bacteria with ≥ 105 colony-forming units per millilitre (CFU/ml). Exclusion criteria were acute kidney injury, chronic renal insufficiency and tumors of the urinary tract. 71 (43.8%) patients had a UTI. Of the 91 patients without UTI, 23 had a contamination and 19 had evidence of ≥ 105 CFU/ml considered to be asymptomatic bacteriuria. The median calprotectin concentration in patients with UTI and pyuria was significantly higher than in patients with UTI and without pyuria (5510.4 vs. 544.7 ng/ml). In ROC analyses, calprotectin revealed an area under the curve (AUC) of 0.70 for the detection of significant bacteriuria. Pyuria in dipstick examinations provided an AUC of 0.71. There was no significant difference between these AUCs in the DeLong test (p = 0.9). In patients with evidence of significant bacteriuria but without pyuria, a significantly higher calprotectin concentration was measured in the urine than in patients with neither pyuria nor UTI (544.7 ng/ml vs 95.6 ng/ml, p = 0.029). Urinary calprotectin is non-inferior to dipstick pyuria in the detection of UTI.

Plasmid-mediated fosfomycin resistance in Escherichia coli isolates of worldwide origin

OBJECTIVES

Fosfomycin is a first-line treatment for uncomplicated urinary tract infections (UTIs) in several European countries, and it is increasingly becoming the treatment of choice globally. Resistance to fosfomycin in Escherichia coli can be exerted through several mechanisms, including the acquisition of fosfomycin-modifying enzymes, of which the FosA-type enzymes are the most common. This study analysed, both phenotypically and genotypically, an international collection of E. coli strains harbouring acquired fosA genes.

METHODS

Thirty-one fosA-positive E. coli isolates were obtained from both clinical and environmental sources, from seven countries (Portugal (n = 12), Switzerland (n = 9), China (n = 3), France (n = 2), Nepal (n = 2), South Africa (n = 2), Kuwait (n = 1)). MICs were determined according to EUCAST guidelines. Whole genome sequencing (WGS) was performed on 23 isolates, and complete fosA plasmid sequences were determined for 12. Conjugation assays were performed on seven isolates.

RESULTS

All isolates exhibited high-level resistance to fosfomycin (64 to >256 mg/L). WGS of 23 isolates identified 17 sequence types (STs), and 16 harboured fosA3, four fosA4, two fosA8, and one fosA10. ESBLs, pAmpC, or carbapenemase genes were present in 15, four, and three isolates, respectively. The fosA plasmids of 12 isolates were determined and were diverse in size (∼67 kb to ∼235 kb), resistance gene carriage, and replicon types. Six fosA plasmids additionally carried ESBL or carbapenemase genes. Conjugation assays, performed on seven isolates harbouring diverse plasmids, identified that all were capable of being transmitted.

CONCLUSION

This study highlights the necessity of the surveillance and close monitoring of fosfomycin resistance in E. coli, essential to maintain the optimal use of this treatment option.

Antimicrobial resistance and its detection in Staphylococcus saprophyticus urinary isolates

The aim of this study was to describe the antibiotic susceptibility of clinical Staphylococcus saprophyticus isolates collected prospectively from urine specimens over a 2-month period from September to October 2022 at a single centre in Melbourne, Australia. Species identification was performed by MALDI-TOF MS. All isolates underwent phenotypic antibiotic susceptibility testing by disc diffusion using European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) guidelines and VITEK2, and mecA polymerase chain reaction. A total of 302 S. saprophyticus isolates from 298 patients were included in this study. Most specimens (91.1%) were referred by community general practitioners from non-hospitalised patients. Antimicrobial resistance to non-β-lactam antibiotics was uncommon; trimethoprim susceptibility was 97%; trimethoprim/sulfamethoxazole, 98%; nitrofurantoin, 100%; and ciprofloxacin, 100% (100% ciprofloxacin susceptible, increased exposure by EUCAST breakpoints). Methicillin resistance (by mecA detection) was the most common form of urinary antibiotic resistance at 5.6%. VITEK2 susceptibility testing for methicillin resistance had a poor specificity of 61.8% (95% CI 55.8-67.4%) compared to mecA detection. These findings indicate that empiric antibiotic recommendations of trimethoprim, trimethoprim/sulfamethoxazole, and nitrofurantoin for treatment of urinary S. saprophyticus remain appropriate.

Water intake and recurrent urinary tract infections prevention: economic impact analysis in seven countries

BACKGROUND

To estimate the economic impact of preventing urinary tract infections (UTI) by increasing water intake among women with recurrent UTI and low fluid intake across seven countries: France, United Kingdom, Spain, United States of America, Mexico, China and Australia.

METHODS

A Markov model was developed to compare costs and outcomes of UTIs associated with low fluid intake in women versus a strategy of primary prevention by increasing water intake. Model inputs were based on randomized controlled trial data which found that increasing water intake by 1.5 L/day decreased the risk of developing cystitis by 48% in women with low fluid intake and recurrent UTI. A time horizon of 10 years was used; outcomes were from the payer perspective and included both direct and indirect costs, reported in 2019 United States dollars ($). Discounting rates varied by country. Scenarios of increasing levels of compliance to the increased water intake strategy were evaluated.

RESULTS

The total cost of one UTI episode, including diagnostics, treatment and complications, ranged from $2164 (Mexico) to $7671 (Australia). Assuming 80% compliance with the increased water intake strategy over a 10-year time horizon, the number of UTIs prevented ranged from 435,845 (Australia) to 24150,272 (China), resulting in total savings of 286 million (Australia) to $4.4 billion (China). Across all countries, increased water intake resulted in lower cost and fewer UTIs compared with low water intake.

CONCLUSION

Preventing recurrent UTIs by increasing water intake would reduce both the clinical and economic burden associated with UTI. Public, healthcare professionals and patients should be made aware about the preventive positive impact of appropriate water intake on UTIs.

Antibiotic Resistance Patterns Among Uropathogens in Female Outpatients Affected by Uncomplicated Cystitis: Focus on Fosfomycin Trometamol

OBJECTIVES

To report the resistance rate against fosfomycin trometamol among outpatient women with symptoms related to urinary tract infections over a 6-year period in a multicentre, cross-sectional study.

METHODS

Urinary samples were collected from three high-volume laboratories from January 2015 to December 2020. The pattern of resistance to fosfomycin was analysed by using the Vitek II automated system.

RESULTS

A total of 7289 urinary samples were collected and 8321 strains were analysed during the study period. The most commonly isolated uropathogen was Escherichia coli (n = 6583, 79.1%). The mean resistance rate against fosfomycin was 9.7% (range 7.1-11.3). No statistically significant difference was found between the three laboratories (P = 0.53). There was no significant increase in resistance rate during the study period. The mean resistance rate against fosfomycin was higher among extended-spectrum β-lactamase (ESBL)-producing bacteria when compared with non-ESBL-producing strains (10.8% vs. 7.9%; P < 0.001).

CONCLUSION

Uropathogens isolated from women affected by cystitis remained highly susceptible to fosfomycin. These findings confirm recommendations in international guidelines that advocate fosfomycin trometamol for empirical treatment of uncomplicated cystitis in women.

Exploring Proteus mirabilis Methionine tRNA Synthetase Active Site: Homology Model Construction, Molecular Dynamics, Pharmacophore and Docking Validation

Currently, the treatment of Proteus mirabilis infections is considered to be complicated as the organism has become resistant to numerous antibiotic classes. Therefore, new inhibitors should be developed, targeting bacterial molecular functions. Methionine tRNA synthetase (MetRS), a member of the aminoacyl-tRNA synthetase family, is essential for protein biosynthesis offering a promising target for novel antibiotics discovery. In the context of computer-aided drug design (CADD), the current research presents the construction and analysis of a comparative homology model for P. mirabilis MetRS, enabling development of novel inhibitors with greater selectivity. Molecular Operating Environment (MOE) software was used to build a homology model for P. mirabilis MetRS using Escherichia coli MetRS as a template. The model was evaluated, and the active site of the target protein predicted from its sequence using conservation analysis. Molecular dynamic simulations were performed to evaluate the stability of the modeled protein structure. In order to evaluate the predicted active site interactions, methionine (the natural substrate of MetRS) and several inhibitors of bacterial MetRS were docked into the constructed model using MOE. After validation of the model, pharmacophore-based virtual screening for a systemically prepared dataset of compounds was performed to prove the feasibility of the proposed model, identifying possible parent compounds for further development of MetRS inhibitors against P. mirabilis.

Antimicrobial susceptibility patterns of community-acquired uropathogenic Escherichia coli, Dublin 2010-2022

Background

Escherichia coli is a common cause of urinary tract infections. Due to the increase in antimicrobial resistance (AMR) and global differences in antimicrobial susceptibility data, routine assessment of local antimicrobial susceptibility patterns is necessary to guide the selection of appropriate empirical therapy. The aim of this study was to evaluate the antimicrobial susceptibility patterns of community-acquired uropathogenic Escherichia coli within a catchment area in Dublin over a 13 year period, 2010-2022.

Methods

All mid-stream urine samples received from local general practitioners in which there was significant E. coli bacteriuria during the study period, 2010-2022, were included in the analysis. Antimicrobial susceptibility testing was performed by disc diffusion as per the European Committee on Antimicrobial Susceptibility Testing recommendations.

Results

An average of 11 407 urine samples per month had significant bacteriuria, with E. coli accounting for an average of 67 % of those. Overall AMR rates were highest for ampicillin (53.9 %), followed by trimethoprim (32.4 %), gentamicin (18.6 %), co-amoxiclav (16.5 %), ciprofloxacin (12.3 %), cephalexin (8.3 %), cefpodoxime (6.8 %) and nitrofurantoin (2 %). While rates appeared grossly static, statistically significant reduced resistance rates were noted for co-amoxiclav (rs=-0.95; P=<0.001), cephalexin prior to 2019 (rs=-0.783; P=0.013) and trimethoprim (rs=-0.639; P=0.019), with a statistically significant increase in non-susceptibility to cefpodoxime (rs=0.802; P=0.001).

Conclusions

In order to generate efficient empirical antimicrobial prescribing guidelines, knowledge of region-specific contemporaneous antimicrobial susceptibility patterns is pivotal. Our findings support the use of nitrofurantoin or cephalexin as empirical antimicrobial therapy within our setting.

Escherichia coli resistance, treatment patterns and clinical outcomes among females with uUTI in Germany: a retrospective physician-based chart review study

Real-world data were collected to examine antimicrobial resistance (AMR) prevalence, treatment patterns, and clinical outcomes among female patients with uncomplicated urinary tract infection (uUTI) in Germany. Data were from a retrospective physician-based chart review completed by physicians treating patients with uUTI. Non-pregnant women aged ≥ 12 years, with a uUTI diagnosis, an E. coli-positive urine culture between January 2017-December 2019, and susceptibility test results for ≥ 4 drug classes were eligible. Patients were stratified into three cohorts by drug class susceptibility: susceptible to all (SUS), resistant to one or two drug classes (DR1/2), and resistant to ≥ 3 (MDR) drug classes tested. Among 386 eligible patients [SUS (67.1%); DR1/2 (29.0%); MDR (3.9%)], AMR prevalence was highest for FMIs (18.3%) and lowest for fluoroquinolones (5.2%). The most prescribed drugs were fosfomycin in SUS (44.0%), DR1/2 (41.4%), and fluoroquinolones in MDR (40.0%). Treatment for uUTI failed for 8.8% of patients; failure was more likely in MDR versus SUS [adjusted odds ratio [95% CI] = 4.21 [1.14-1.50]; P = 0.031); incidence of recurrent infection in the 6-months post-index period was higher in DR1/2 versus SUS. These findings may have implications for empiric prescribing, suggesting an unmet need for new treatments.

Effect of Gravity on Bacterial Adhesion to Heterogeneous Surfaces

Bacterial adhesion is the first step in the formation of surface biofilms. The number of bacteria that bind to a surface from the solution depends on how many bacteria can reach the surface (bacterial transport) and the strength of interactions between bacterial adhesins and surface receptors (adhesivity). By using microfluidic channels and video microscopy as well as computational simulations, we investigated how the interplay between bacterial transport and adhesivity affects the number of the common human pathogen Escherichia coli that bind to heterogeneous surfaces with different receptor densities. We determined that gravitational sedimentation causes bacteria to concentrate at the lower surface over time as fluid moves over a non-adhesive region, so bacteria preferentially adhere to adhesive regions on the lower, inflow-proximal areas that are downstream of non-adhesive regions within the entered compartments. Also, initial bacterial attachment to an adhesive region of a heterogeneous lower surface may be inhibited by shear due to mass transport effects alone rather than shear forces per se, because higher shear washes out the sedimented bacteria. We also provide a conceptual framework and theory that predict the impact of sedimentation on adhesion between and within adhesive regions in flow, where bacteria would likely bind both in vitro and in vivo, and how to normalize the bacterial binding level under experimental set-ups based on the flow compartment configuration.

Predictors of antepartum maternal sepsis and effects on neonatal outcomes: a population-based cohort study

OBJECTIVE

To examine the relationship between maternal sepsis, type of infection, and short-term neonatal outcomes.

STUDY DESIGN

We conducted a retrospective cohort study investigating pregnancies between 2005 and 2008 in California with antepartum maternal sepsis diagnosis. Comparisons were made between sepsis cases and controls, using chi-squared or Fisher's exact test. Multivariable logistic regression was performed, adjusting for maternal characteristics.

RESULTS

Several maternal characteristics were associated with increased odds of maternal sepsis. Both obstetric and non-obstetric infections were associated with maternal sepsis (p < 0.001). The positive predictive value of maternal sepsis for preterm delivery was 55.03%. Neonates born to maternal sepsis patients had a higher risk of developing neonatal complications including neonatal shock.

CONCLUSION

Maternal sepsis was associated with neonatal complications. Efforts to reduce maternal sepsis may improve neonatal outcomes. Further studies are required for a better understanding of these associations and whether prevention or more rapid diagnosis and treatment can lower these risks.

Uropathogens' Antibiotic Resistance Evolution in a Female Population: A Sequential Multi-Year Comparative Analysis

Urinary Tract Infections (UTIs) represent a common finding among females and an important basis for antibiotic treatment. Considering the significant increase in antibiotic resistance during the last decades, this study retrospectively follows the incidence of uropathogens and the evolution of resistance rates in the short and medium term. The current study was conducted at the "Prof. Dr. Th. Burghele" Clinical Hospital, including 1124 positive urine cultures, in three periods of four months between 2018 and 2022. Escherichia coli was the most frequent uropathogen (54.53%), followed by Klebsiella spp. (16.54%), and Enterococcus spp. (14.59%). The incidence of UTIs among the female population is directly proportional to age, with few exceptions. The highest overall resistance in Gram-negative uropathogens was observed for levofloxacin 30.69%, followed by ceftazidime 13.77% and amikacin 9.86%. The highest resistance in Gram-positive uropathogens was observed for levofloxacin 2018-R = 34.34%, 2020-R = 50.0%, and 2022-R = 44.92%, and penicillin 2018-R = 36.36%, 2020-R = 41.17%, and 2022-R = 37.68%. In Gram-negative uropathogens, a linear evolution was observed for ceftazidime 2018-R = 11.08%, 2020-R = 13.58%, and 2022-R = 17.33%, and levofloxacin 2018-R = 28.45%, 2020-R = 33.33%, and 2022-R = 35.0%. The current knowledge dictates the need to continuously assess antimicrobial resistance patterns, information that is necessary for treatment recommendations. The present study aims to determine the current situation and the evolution trends according to the current locoregional situation.

Nitrite-negative results in urinary tract infection by Enterobacterales: does the nitrite dipstick test have low sensitivity?

Urinary tract infection (UTI) is one of the most common bacterial infections among humans. Urine culture is the gold standard diagnostic method for UTI; however, the dipstick test for nitrite is a widely used method signalling the presence of urinary nitrate-reducing bacteria. Unlike the gold standard, the dipstick test is easy to perform, while it is also less time-consuming and less expensive, and produces a result in a few minutes. This study investigates the sensitivity of the dipstick test for nitrite compared with the Griess test in urine samples from UTI caused by Enterobacterales species. We used the Griess test, which is the gold standard in nitrite measurement, to determine the sensitivity of the nitrite dipstick test. Semiquantitative urine culture was performed using standard procedures, and Enterobacterales identification was performed by manual conventional biochemical tests. In the first sample selection, 3 % (8/267) of urine samples suspected of UTI, analysed from March to April 2016, were nitrite-negative by dipstick test but positive for Enterobacterales in the urine culture. In the second sample selection, 5 % (2/44) of urine samples from October to December 2022 were also nitrite-negative but showed urine Enterobacterales isolation. All nitrite-negative dipstick results were consistent with the Griess test. Escherichia coli was the most prevalent bacterium, followed by Klebsiella pneumoniae, independent of sample selection. The dipstick test is a safe alternative for investigating nitrite in urine samples. We believe that the cause of nitrite-negative results is a lack of dietary nitrate, dilution of urine and exogenous interference (e.g. ascorbic acid). These findings support the idea that standard urine culture is necessary to rule out UTI.

Fast identification and susceptibility determination of E. coli isolated directly from patients' urine using infrared-spectroscopy and machine learning

For effective treatment, it is crucial to identify the infecting bacterium at the species level and to determine its antimicrobial susceptibility. This is especially true now, when numerous bacteria have developed multidrug resistance to most commonly used antibiotics. Currently used methods need ∼ 48 h to identify a bacterium and determine its susceptibility to specific antibiotics. This study reports the potential of using infrared spectroscopy with machine learning algorithms to identify E. coli isolated directly from patients' urine while simultaneously determining its susceptibility to antibiotics within ∼ 40 min after receiving the patient's urine sample. For this goal, 1,765 E. coli isolates purified directly from urine samples were collected from patients with urinary tract infections (UTIs). After collection, the samples were tested by infrared microscopy and analyzed by machine learning. We achieved success rates of ∼ 96% in isolate level identification and ∼ 84% in susceptibility determination.

A Randomized Controlled Trial Comparing a New D-Mannose-based Dietary Supplement to Placebo for the Treatment of Uncomplicated Escherichia coli Urinary Tract Infections

BACKGROUND

The rise in antimicrobial resistance means that alternative approaches for the treatment and prevention of urinary tract infection (UTIs) are required.

OBJECTIVE

To evaluate the safety and efficacy of a D-mannose-based dietary supplement (D-mannose, citric acid, prebiotic fibers, Astragalus, and dandelion; DAPAD complex) for the treatment of uncomplicated acute E. coli UTIs.

DESIGN, SETTING, AND PARTICIPANTS

This was a single-center, randomized, double-blind, placebo-controlled trial conducted from April 2021 to October 2021 in Rajalakshmi Hospital and Research Centre (Bangalore, India). The participants were nonmenopausal women with an acute uncomplicated E. coli UTI. UTI was diagnosed according to the presence of at least one urinary symptom and bacteriuria (>100 000 CFU/ml).

INTERVENTION

The DAPAD complex was administered twice a day for 5 d, with phenazopyridine and alkalizing agents as the standard of care (SOC). The control group received placebo with SOC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Subjective (clinical resolution/response) and objective (midstream bacteriuria) outcomes were evaluated at the end of therapy (day 6) and at day 35 of follow-up. Adverse events were recorded. Categorical variables were analyzed using χ² and Fisher's exact tests; a p value <0.05 was considered significant.

RESULTS AND LIMITATIONS

Seventy women were enrolled and equally randomized to the two groups. Clinical resolution was higher in the DAPAD group at 6 d (34.3% vs 0%; p < 0.0001) and 35 d from baseline (88.6% vs 20%, p < 0.0001). At day 35, no patients in the DAPAD group had moderate or severe symptoms, whereas 25.7% (nine/35) and 11.4% (four/35) of patients in the placebo group had moderate and severe symptoms, respectively. Bacteriological resolution was also higher in the DAPAD group at day 6 (85.7% vs 14.3%; p < 0.0001) and day 35 (100% vs 40%; p < 0.0001). Three mild adverse events (4.26%) unrelated to the investigated product were recorded, all of which were medically treated.

CONCLUSIONS

The DAPAD complex dietary supplement is effective and safe for treatment of acute uncomplicated E. coli UTIs.

PATIENT SUMMARY

Our results show that for nonmenopausal women with an uncomplicated Escherichia coli urinary tract infection, those treated with a dietary supplement (containing D-mannose, citric acid, prebiotic fibers, Astragalus, and dandelion) had a higher rate of clinical resolution or response than women who received a placebo.

Prevalence and Antimicrobial Sensitivity Patterns of Uropathogens, in Tikur Anbessa Specialized Hospital Emergency Medicine Department Addis Ababa, Ethiopia

Background

Empirical treatment of infections remains a major contributing factor to the emergence of pathogens that are resistant to antibiotics. The study aimed to assess the prevalence and anti-microbial sensitivity patterns of uropathogens in the Emergency Medicine Department of Tikur Anbessa Hospital, Ethiopia.

Methods

Urine sample data collected over two years from January 2015 to January 2016 at Tikur Anbessa Hospital's laboratory were retrospectively analyzed for bacterial pathogens, and their antimicrobial susceptibility. Antimicrobial sensitivity tests were done using the disc diffusion technique as per the standard of the Kirby-Bauer method.

Results

Of the total 220 samples that were collected, 50 (22.7%) were culture-positive. Male to female data ratio was 1:1.1. Escherichia coli was the dominant isolate (50%) followed by Enterococcus species (12%), Enterobacter species (12%), and Klebsiella species (8%). Overall resistance rates to Cotrimoxazole, Ampicillin, Augmentin, and Ceftriaxone were 90.4%, 88.8%, 82.5%, and 79.3%, respectively. The sensitivity rates for Chloramphenicol, Amikacin, Vancomycin, Meropenem, Cefoxitin, and Nitrofurantoin ranged from 72% to 100%. The antibiogram of isolates showed that 43 (86%) isolates were resistant to two or more antimicrobials, and 49 (98%) were resistant to at least one antibiotic.

Conclusion and Recommendation

Urinary tract infections are mostly caused by Gram-negative bacteria predominantly in females and Escherichia coli are the most common isolates. Resistance rates to Cotrimoxazole, Ampicillin, Augmentin, and Ceftriaxone were high. Chloramphenicol, Amikacin, Vancomycin, Meropenem, Cefoxitin, and Nitrofurantoin are considered appropriate antimicrobials for the empirical treatment of complicated urinary tract infections in the emergency department. Yet, using antibiotics indiscriminately for patients with complicated UTIs may increase the resistance rate and also lead to treatment failure, hence the prescriptions should be revised following the culture and sensitivity results.

Older patient age and prior antimicrobial use strongly predict antimicrobial resistance in Escherichia coli isolates recovered from urinary tract infections among female outpatients

BACKGROUND

Increasing prevalence of antimicrobial resistance (AMR), including multidrug resistance (MDR), among Escherichia coli (E. coli) makes treatment of uncomplicated urinary tract infection (uUTI) difficult. We assessed risk factors for fluoroquinolone (FQ)-not-susceptible (NS) and MDR E. coli among US female outpatients.

METHODS

This retrospective cohort study utilized data from female outpatients aged ≥ 12 years with E. coli positive urine culture and oral antimicrobial prescription ± 1 day from index. We assessed patient-level factors within 90 and 91-360 days prior to index as predictors of FQ NS (intermediate/resistant) and MDR (NS to ≥ 1 drug across ≥ 3 classes) E. coli: age, prior oral antimicrobial dispensing, prior AMR phenotypes, prior urine culture, and prior hospitalization.

RESULTS

Among 1,858 outpatients with urine-isolated E. coli, 369 (19.9%) had FQ NS and 59 (3.2%) had MDR isolates. After multivariable adjustment, independent risk factors (p < 0.03) for FQ NS E. coli were older age, prior FQ NS isolates, prior dispensing of FQ, and dispensing of any oral antibiotic. Independent risk factors (p < 0.02) for MDR were prior extended-spectrum β-lactamase-producing isolates (ESBL+), prior FQ dispensing, and prior oral antibiotic dispensing.

CONCLUSIONS

In women with uUTI due to E. coli, prior dispensing of FQ or any oral antibiotic within 90 days predicted FQ NS and MDR urine E. coli. Prior urine culture with FQ NS isolates and older age were predictive of FQ NS E. coli. Prior ESBL+ was predictive of MDR E. coli. These data could help identify patients at risk for AMR E. coli and inform empiric prescribing.

Methenamine hippurate to prevent recurrent urinary tract infections in older women: protocol for a randomised, placebo-controlled trial (ImpresU)

INTRODUCTION

Methenamine hippurate is a urinary antiseptic used as preventive treatment for recurrent urinary tract infections (UTIs) in some Scandinavian countries. However, the scientific evidence for the preventive effect and safety for longer-term use is limited. The aim of this study is to assess whether methenamine hippurate can reduce the incidence of UTIs in older women with recurrent UTIs.

METHODS AND ANALYSIS

The ImpresU consortium is a collaboration between Norway, Sweden, Poland and the Netherlands. The study is a randomised, controlled, triple-blind phase IV clinical trial. Women ≥70 years with recurrent UTIs are screened for eligibility in a general practice setting. We aim to include 400 women in total, with 100 recruited from each collaborating country. The participants are randomised to treatment with methenamine hippurate 1 g or placebo tablets two times per day for a treatment period of 6 months, followed by a drug-free follow-up period of 6 months. The primary outcome is number of antibiotic treatments for UTIs during the treatment period. The secondary outcomes include number of antibiotic treatments for UTIs during the follow-up period and self-reported symptom of severity and duration of UTI episodes. Differences in complications between the treatment groups are measured as safety outcomes. We also aim to investigate whether strain characteristics or phylogenetic subgroups of Escherichia coli present in the urine culture at inclusion have a modifying effect on the outcomes.

ETHICS AND DISSEMINATION

Ethical approvals are obtained in all participating countries. The results will be communicated in peer-reviewed journals and at scientific conferences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04077580); EudraCT: 2018-002235-15.

Rationale for choosing an antibiotic for the treatment of cystitis: recommendations of clinical pharmacologists: A review

In recent years, the harmonization of domestic and foreign clinical recommendations for the treatment of cystitis has been achieved. Nitrofurans and fosfomycin trometamol are recommended as first line therapy antibiotics, and oral 3rd generation of cephalosporins are recommended as alternative antibiotics; fluoroquinolones are excluded from the recommended medications due to an unfavorable safety profile. The main rationale for inclusion of antibiotics in the recommendations as a first line therapy of cystitis is the level of resistance of uropathogens to antibiotics, primarily Escherichia coli. Stable low level of resistance of E. coli in Russia was noted to nitrofurans and fosfomycin (5%), higher to cephalosporins. Among nitrofurans, furazidine is characterized by higher activity against E. coli compared to nitrofurantoin. The potassium salt of furazidine in dosage form with magnesium carbonate is preferred, since it is characterized by higher bioavailability and provides a therapeutic level of concentrations in urine above the MIC during the entire dosing period. Due to the global increase in the resistance of uropathogens observed in recent years, experts have begun to pay more and more attention to the ecological safety of antimicrobial therapy in order to minimize the risk of concomitant (collateral) damage, contributing to the selection of multi-drug resistant strains of microorganisms. In the latest WHO document of 2021, experts divided antibiotics into three groups (ACCESS, WATCH, RESERVE) according to the priority of choice. The ACCESS group of drugs for the treatment of cystitis includes nitrofurantoin and furazidine as agents with minimal collateral effect, while fosfomycin trometamol and cephalosporins are listed in the WATCH group. Thus, from the standpoint of ecological safety, WHO experts recommend prescribing nitrofurans in the treatment of cystitis in the first line of therapy.

Escherichia coli from urine samples of pregnant women as an indicator for antimicrobial resistance in the community: a field study from rural Burkina Faso

Background

In low- and middle-income countries, surveillance of antimicrobial resistance (AMR) is mostly hospital-based and, in view of poor access to clinical microbiology, biased to more resistant pathogens. We aimed to assess AMR among Escherichia coli isolates obtained from urine cultures of pregnant women as an indicator for community AMR and compared the AMR results with those from E. coli isolates obtained from febrile patients in previously published clinical surveillance studies conducted within the same population in Nanoro, rural Burkina Faso. We furthermore explored feasibility of adding urine culture to standard antenatal care in a rural sub-Saharan African setting.

Methods

Between October 2016–September 2018, midstream urine samples collected as part of routine antenatal care in Nanoro district were cultured by a dipslide method and screened for antibiotic residues. Significant growth was defined as a pure culture of Enterobacterales at counts of ≥ 104 colony forming units/ml.

Results

Significant growth was observed in 202/5934 (3.4%) cultures; E. coli represented 155 (76.7%) of isolates. Among E. coli isolates, resistance rates to ampicillin, cotrimoxazole and ciprofloxacin were respectively 65.8%, 64.4% 16.2%, compared to 89.5%, 89.5% and 62.5% among E. coli from clinical isolates (n = 48 of which 45 from blood cultures). Proportions of extended spectrum beta-lactamase producers and multidrug resistance were 3.2% and 5.2% among E. coli isolates from urine in pregnant women versus 35.4%, and 60.4% respectively among clinical isolates.

Conclusions

The E. coli isolates obtained from healthy pregnant women had significantly lower AMR rates compared to clinical E. coli isolates, probably reflecting the lower antibiotic pressure in the pregnant women population. Adding urine culture to the routine urine analysis (dipstick) of antenatal care was feasible. The dipslide culture method was affordable and user-friendly and allowed on-site inoculation and easy transport; challenges were contamination (midstream urine sampling) and the semi-quantitative reading. Provided confirmation of the present findings in other settings, E. coli from urine samples in pregnant women may be a potential indicator for benchmarking, comparing, and monitoring community AMR rates across populations over different countries and regions.

Preventive effect of methenamine in women with recurrent urinary tract infections - a case-control study

BACKGROUND

Urinary tract infection (UTI) is the most common bacterial infection in women. In Norwegian general practice, methenamine has been prescribed for many years as long-term prevention and accounted for 20% of the total antibiotic prescribing in 2015, as measured in defined daily dosages (DDDs). The efficacy of methenamine is unknown. If shown to be effective, this drug may become an important preventive against UTI.

OBJECTIVE

To examine whether methenamine is preventive against recurrent UTI in women.

DESIGN

Data for all antibiotics used for UTIs dispensed from all pharmacies from 2005 to 2015 were collected from the Norwegian prescription database (NorPD).

SUBJECTS

Women aged ≥ 40 years with recurrent UTI, defined as ≥3 courses of UTI antibiotic/year, were included.

MAIN OUTCOME MEASURES

Patients using methenamine (cases) and those not using methenamine (controls) were compared. The numbers of UTI prescriptions during the 2 years before and after inclusion were analysed. Results: The yearly prevalence for recurrent UTI was 2.4% in women ≥ 40 years. The change in antibiotic use from 2 years before to 2 years after inclusion in the study differed significantly between groups: 44.6 and 34.9% reductions in the number of antibiotic prescriptions for UTI in the methenamine and control groups, respectively. The decrease in UTI antibiotic prescriptions (58.9%) was greater in patients with a higher consumption of antibiotics before starting methenamine.

CONCLUSIONS

Methenamine seems to be effective against recurrent UTI over the time span studied. The effect seems to be greater in patients with the highest number of recurrent UTIs. Key pointsMethenamine has been used for many years for prevention of recurrent UTI, but no studies have demonstrated a significant preventive effect of long time use.This study shows that methenamine seems to be effective for prevention in patients having recurrent UTI over 2 years or more.The effect seems to be larger in patients with a high number of UTIs over 2 years.

High antimicrobial resistance in urinary tract infections in male outpatients in routine laboratory data, Germany, 2015 to 2020

Background

Evidence on the distribution of bacteria and therapy recommendations in male outpatients with urinary tract infections (UTI) remains insufficient.

Aim

We aimed to report frequency distributions and antimicrobial resistance (AMR) of bacteria causing UTI in men and to identify risk factors for resistance of Escherichia coli against trimethoprim (TMP) and ciprofloxacin (CIP).

Methods

We conducted a retrospective observational study using routinely collected midstream urine specimens from 102,736 adult male outpatients sent from 6,749 outpatient practices to nine collaborating laboratories from all major regions in Germany between 2015 and 2020. Resistance in E. coli was predicted using logistic regression.

Results

The three most frequent bacteria were E. coli (38.4%), Enterococcus faecalis (16.5%) and Proteus mirabilis (9.3%). Resistance of E. coli against amoxicillin (45.7%), TMP (26.6%) and CIP (19.8%) was common. Multiple drug resistance was high (22.9%). Resistance against fosfomycin (0.9%) and nitrofurantoin (1.9%) was low. Resistance of En. faecalis against CIP was high (29.3%). Isolates of P. mirabilis revealed high resistance against TMP (41.3%) and CIP (16.6%). The CIP and TMP resistance was significantly higher among bacteria derived from recurrent UTI (p < 0.05). Age ≥ 90 years, recurrent UTI and regions East and South were independently associated with AMR of E. coli against TMP and CIP (p < 0.05).

Conclusion

The most frequent UTI-causing pathogens showed high resistance against TMP and CIP, empirical therapy is therefore likely to fail. Apart from intrinsically resistant pathogens, susceptibility to fosfomycin and nitrofurantoin remains sufficient. Therefore, they remain an additional option for empirical treatment of uncomplicated UTI in men.

Decreasing susceptibility of bacteria to ampicillin/ sulbactam and third generation cephalosporins in urinary tract infections

Background

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide and have become more difficult to treat over the years. Inappropriate antibiotic use has led to increased antibiotic resistance.

Materials and methods

We examined 1921 urine culture samples from a single hospital and analyzed them for bacterial spectrum and antibiotic susceptibility. We further analyzed changes in the rates of detected bacteria and of the sensitivity of these uropathogens to antibiotics over the years.

Results

In our hospital-based analysis, cystitis was the most frequently diagnosed UTI in women (76%) and men (79%). Escherichia coli (48%) was the most commonly identified uropathogen. Samples demonstrated an increase in the proportion of E. coli (p < 0.001) and a decrease in Enterococcus faecalis (p < 0.001) over the study time period. Antimicrobial susceptibility analysis showed an increase over time in the number of isolates with resistance to ampicillin/sulbactam (p < 0.001) and to third-generation cephalosporins cefotaxime (p = 0.043) and ceftazidime (p < 0.001).

Conclusions

Ampicillin/sulbactam and third-generation cephalosporins are antibiotics frequently used in the treatment of UTIs. When selecting an optimal antimicrobial treatment regimen for patients with UTIs, it is imperative to understand regional and timedependent differences in the prevalence of various uropathogens and antimicrobial resistance patterns. Therefore, continuous surveillance of local pathogen and antimicrobial susceptibility patterns for frequently used antibiotics should be prioritized.

Occurrence and Genomic Characterization of Clone ST1193 Clonotype 14-64 in Uncomplicated Urinary Tract Infections Caused by Escherichia coli in Spain

We conducted a prospective, multicenter, specific pilot study on uncomplicated urinary tract infections (uUTI). One-hundred non-duplicated uropathogenic Escherichia coli (UPEC) from uUTI occurred in 2020 in women attending 15 primary care centers of a single health region of northern Spain were characterized using a clonal diagnosis approach. Among the high genetic diversity showed by 59 different phylogroup-clonotype combinations, 11 clones accounted for 46% of the isolates: B2-ST73 (CH24-30); B2-ST73 (CH24-103); B2-ST131 (CH40-30); B2-ST141 (CH52-5); B2-ST372 (CH103-9); B2-ST404 (CH14-27); B2-ST404 (CH14-807); B2-ST1193 (CH14-64); D-ST69 (CH35-27); D-ST349 (CH36-54), and F-ST59 (CH32-41). The screening of the UPEC status found that 69% of isolates carried ≥ 3 of chuA, fyuA, vat, and yfcV genes. Multidrug resistance to at least one antibiotic of ≥ 3 antimicrobial categories were exhibited by 30% of the isolates, with the highest rates of resistance against ampicillin/amoxicillin (48%), trimethoprim (35%), norfloxacin (28%), amoxicillin-clavulanic acid (26%), and trimethoprim-sulfamethoxazole (24%). None extended-spectrum beta-lactamase/carbapenemase producer was recovered. According to our results, fosfomycin and nitrofurantoin should be considered as empirical treatment of choice for uUTI by E. coli (resistance rates 4% and 2%, respectively). We uncover the high prevalence of the pandemic fluoroquinolone-resistant ST1193 clone (6%) in uUTI, which represents the first report in Spain in this pathology. The genomic analysis showed similar key traits than those ST1193 clones disseminated worldwide. Through the SNP comparison based on the core genome, the Spanish ST1193 clustered with isolates retrieved from the Enterobase, showing high genomic similarity than the global ST1193 described in the United States, Canada and Australia.

IMPORTANCE Analyzing the clonal structure and antimicrobial resistance of E. coli isolates implicated in uncomplicated urinary tract infections, one of the most frequent visits managed in primary health care, is of interest for clinicians to detect changes in the dynamics of emerging uropathogenic clones associated with the spread of fluoroquinolone resistance. It can also provide consensus concerning optimal control and antibiotic prescribing.

First Record of Dissemination of BLBLI-Resistant Enterobacter cloacae from Public Hospitals in Baghdad, Iraq

Background:

Enterobacter cloacae are most frequently isolated from human clinical specimens.

Objective:

This cross-sectional study aimed to investigate the dissemination of E. cloacae clinical isolates resistant to β-lactam-β-lactamase inhibitor (BLBLI) combinations from different clinical specimens of hospitalized patients.

Methods:

E. cloacae isolates were recovered from different clinical samples of hospitalized patients in three main hospitals in Baghdad city. E. cloacae isolates were identified based on their morphology and biochemical tests, and the identification was confirmed using Vitek-2 system. The antibiotic susceptibility testing of E. cloacae isolates to a variety of antibiotics was achieved using disc diffusion test (DDT) and Vitek-2 system.

Results:

Results found that among 335 culture-positive samples, 30 isolates (8.9%) belonged to E. cloacae. A high rate of isolation was observed in urine isolates (46.6%), followed by wounds (burns) isolates (26.6%). Out of 30 E. cloacae strains isolated during this study, 18 (60%) showed reduced susceptibility to BLBLI combinations. TEM genes (TEM-1 and TEM-2) were successfully amplified from 7/18 isolates (38.8%) and high rate of BLBLI genes was detected (CTX-M, bla-SHV, SHV-2, and OXA-1). However, no BLBLI genes of bla-AmpC, bla- OXA-2, and bla- OXA-10 were found in E. cloacae isolates when tested using specific primers for bla-AmpC and bla-OXA genes.

Conclusion:

From this study, we can conclude that the production of inhibitor-resistant β-lactamases by E. cloacae isolates could be increasingly common in nosocomial pathogens other than E. coli or K. pneumoniae in public hospitals in Baghdad, Iraq.

Risk factors for concomitant positive midstream urine culture in patients presenting with symptomatic ureterolithiasis

In patients with symptomatic ureterolithiasis, immediate treatment of concomitant urinary tract infection (UTI) may prevent sepsis. However, urine cultures require at least 24 h to confirm or exclude UTI, and therefore, clinical variables may help to identify patients who require immediate empirical broad-spectrum antibiotics and surgical intervention. Therefore, we divided a consecutive cohort of 705 patients diagnosed with symptomatic ureterolithiasis at a single institution between 2011 and 2017 into a training (80%) and a testing cohort (20%). A machine-learning-based variable selection approach was used for the fitting of a multivariable prognostic logistic regression model. The discriminatory ability of the model was quantified by the area under the curve (AUC) of receiver-operating curves (ROC). After validation and calibration of the model, a nomogram was created, and decision curve analysis (DCA) was used to evaluate the clinical net-benefit. UTI was observed in 40 patients (6%). LASSO regression selected the variables elevated serum CRP, positive nitrite, and positive leukocyte esterase for fitting of the model with the highest discriminatory ability. In the testing cohort, model performance evaluation for prediction of UTI showed an AUC of 82 (95% CI 71.5–95.7%). Model calibration plots showed excellent calibration. DCA showed a clinically meaningful net-benefit between a threshold probability of 0 and 80% for the novel model, which was superior to the net-benefit provided by either one of its singular components. In conclusion, we developed and internally validated a logistic regression model and a corresponding highly accurate nomogram for prediction of concomitant positive midstream urine culture in patients presenting with symptomatic ureterolithiasis.

International travel and travelers' diarrhea - Increased risk of urinary tract infection

BACKGROUND

Urinary tract infections (UTIs) rank among the most common infections encountered in health care, with an annual incidence of 12% for women. Despite the vast numbers of international travels (over 1.5 billion annually), no prospective studies have had primary focus on UTIs during travel.

METHODS

We recruited in 2008-17 international travelers who all filled out pre- and post-travel questionnaires. Incidence rates of UTI were calculated separately for both sexes. Multivariable analyses were conducted to identify risk factors for UTI during travel.

RESULTS

In total 15/517 (2,9%) travelers acquired UTI during travel, yielding an annual incidence of 62% for female and 18% for male travelers. Travelers' diarrhea (TD) was identified as a factor predisposing to UTI (OR 9.2, 95% CI 1.5-+∞, p = 0.011); all UTI cases were recorded by travelers with TD.

CONCLUSIONS

To our knowledge, this is the first prospective study with a primary focus on UTI during travel. Our data reveal that among travelers the incidence of UTI far exceeds that reported for the general population. TD was identified as a major risk factor for the infection. Our results highlight the need for TD prevention as a means of also preventing UTI during travel.

Culture Requests and Multi-Drug Resistance among Suspected Urinary Tract Infections in Two Tertiary Hospitals in Freetown, Sierra Leone (2017-21): A Cross-Sectional Study

In sub-Saharan Africa, there is limited information about the use of microbiology laboratory services in patients with suspected urinary tract infections (UTIs). This cross-sectional study assessed the requests for urine culture in patients with suspected UTI in two tertiary (maternal and paediatric) hospitals—Freetown and Sierra Leone, during May 2017–May 2021—and determined antimicrobial resistance (AMR) patterns among bacterial isolates. One laboratory served the two hospitals, with its electronic database used to extract information. Overall, there were 980 patients, of whom 168 (17%) had cultures requested and performed. Of these, 75 (45%) were culture positive. During 2017–2019, there were 930 patients, of whom 156 (17%) had cultures performed. During 2020–2021, when services were disrupted by the COVID-19 pandemic, there were 50 patients, of whom 12 (24%) had cultures performed. The four commonest isolates were Escherichia coli (36), Klebsiella pneumoniae (10), Staphylococcus aureus (9), and Pseudomonas spp. (6). There were high levels of AMR, especially for trimethoprim-sulfamethoxazole (47%), nalidixic acid (44%), nitrofurantoin (32%) and cefotaxime (36%). Overall, 41 (55%) bacterial isolates showed multidrug resistance, especially E. coli (58%), Pseudomonas spp. (50%), and S. aureus (44%). These findings support the need for better utilization of clinical microbiology services to guide antibiotic stewardship and monitoring of trends in resistance patterns.

Clinical effectiveness of beta-lactams versus fluoroquinolones as empirical therapy in patients with diabetes mellitus hospitalized for urinary tract infections: A retrospective cohort study

Background

Diabetic patients are at risk of severe urinary tract infections (UTIs). Due to the emerging resistance rates to fluoroquinolones and β-lactams, we aimed to evaluate the effectiveness of β-lactams versus fluoroquinolones as empirical therapy for diabetic patients hospitalized for UTIs.

Methods

A retrospective cohort study was conducted in a medical center in Taiwan between 2016 and 2018. Patients with type 2 diabetes, aged ≥20 and hospitalized for UTIs were enrolled. Patients with UTI diagnosis within one year before the admission, co-infections at the admission, or ≥2 pathogens in the urine cultures were excluded. The primary outcome was empiric treatment failure.

Results

298 patients were followed for at least 30 days after the admission. Escherichia coli (61.07%) was the most common pathogen. The resistance rates of the pathogens to levofloxacin were 28.52% and 34.22% according to the historical Clinical and Laboratory Standards Institute (CLSI) breakpoints and the updated 2019 CLSI breakpoints, respectively. The resistance rates of ceftazidime and cefepime were 21.81% and 11.41%, respectively. Empirical β-lactams were associated with less treatment failure compared to fluoroquinolones (adjusted OR = 0.32, 95% CI = 0.17–0.60). Beta-lactams were associated with less treatment failure than fluoroquinolones when appropriatness was determined by the pre-2019 CLSI breakpoints but not the 2019 CLSI breakpoints.

Conclusions

In diabetic patients hospitalized for UTIs, β-lactams were associated with less empiric treatment failure compared to fluoroquinolones when the resistance rate to fluoroquinolone is higher than β-lactams. The updated 2019 CLSI breakpoint for fluoroquinolone was better than pre-2019 CLSI breakpoints to correlate with treatment outcomes for hospitalized UTIs in diabetic patients.

Influence of Antimicrobial Resistance on the Course of Symptoms in Female Patients Treated for Uncomplicated Cystitis Caused by Escherichia coli

Background: Resistance to the prescribed antibiotic causes a longer duration of symptoms in patients with urinary tract infection. Yet, a study found that patients infected with trimethoprim-resistant Escherichia coli (E. coli) had a prolonged duration of symptoms even if treated with an antibiotic to which the strain was susceptible. The purpose of this study was to attempt to reproduce this finding in a different cohort. Methods: We analyzed data from two studies from general practice in the Capital Region of Denmark including patients from 2014 to 2016. The primary outcome was the severity of frequency and dysuria. The secondary outcome was the number of days until symptoms had disappeared. Results: We included 180 women treated for uncomplicated cystitis caused by E. coli. We found that 16.11% (n = 29) of the E. coli strains were resistant to all of the three selected antibiotics (ampicillin, sulfamethizole and trimethoprim). There was no significant difference in severity or time until the symptoms had disappeared between women infected with resistant or susceptible E. coli. Conclusions: Strains of E. coli resistant to ampicillin, sulfamethizole and trimethoprim causing uncomplicated cystitis do not result in more severe symptoms or a longer symptom duration if treated with an antibiotic to which they are susceptible.

Studies on Virulence and Extended-Spectrum β-Lactamase-Producing Uropathogenic Escherichia coli Isolates and Therapeutic Effect of Fosfomycin in Acute Pyelonephritis Mice

The understanding about virulence factors (VFs) and the drug resistance of uropathogenic Escherichia coli (UPEC) helps us understand the pathogenesis of urinary tract infections (UTIs) and make better decisions for clinical treatment. This study examined the correlation between the extended-spectrum β-lactamases (ESBLs) phenotype and VFs in UPEC strains. In addition, we validated the therapeutic potential of fosfomycin in acute pyelonephritis mice. From May 2017 to November 2018, 22 nonduplicate E coli. strains were isolated from UTI patients. PCR was utilized to detect the distribution of virulence genes. We also analyzed the ESBL phenotype in E coli. We further evaluated the therapeutic effect of intravenous fosfomycin treatment in the acute pyelonephritis (APN) model. All 22 UPEC strains expressed the type 1 fimbriae (FimH) gene and more than 50% (12/22) of strains produced ESBLs. The detection rates of the iron acquisition-associated genes ChuT and IutA were 77.3% (n = 17) and 50% (n = 11) and those of P fimbria papA and papC genes were 45% (n = 10) and 50% (n = 11), respectively. Though the VFs were closely related with pathologenicity, the relationship between VFs and ESBLs still needs further investigation. Furthermore, intravenous fosfomycin 800 mg/kg significantly reduced the bacterial load and the inflammatory infiltration in the bladder and kidney, maintaining the structural integrity of the kidney. Intravenous fosfomycin administration can be used for the treatment of acute pyelonephritis caused by highly pathogenic and drug-resistant UPEC strains.

Fluoroquinolones and Other Antibiotics Redeemed for Cystitis—A Swedish Nationwide Cohort Follow-Up Study (2006–2018)

Background: Antibiotics are commonly prescribed for outpatient management of cystitis. Previous evidence suggests that certain factors likely beyond the infection seem to influence the choice of antimicrobial treatment. However, studies on the specific antibiotic treatments for cystitis are lacking. This study aimed to explore the antibiotic treatments for cystitis using nationwide primary healthcare data and investigate if factors beyond the infection could be associated with fluoroquinolone treatment. Methods: This nationwide follow-up cohort study consisted of 352,507 women with cystitis. The primary aim was to investigate what specific classes of antibiotics were redeemed by patients within five days from the cystitis diagnosis. Each patient could only be included once. Logistic regression models were also used to examine the relationship between fluoroquinolone (FQ) treatment, parity, and sociodemographic factors. Results: In total, 192,065 antibiotic prescriptions were redeemed. Pivmecillinam (58.4%) followed by nitrofurantoin (22.2%), trimethoprim (12.0%), fluoroquinolone (5.6%), and cephalosporins (1.5%) were the most redeemed antibiotics. Sociodemographic factors were weakly associated with fluoroquinolone treatment; young age was inversely associated with fluoroquinolone treatment. Parity and cervical cancer history were not associated with fluoroquinolone treatment. The proportion of fluoroquinolone and trimethoprim treatments decreased over time, while pivmecillinam and nitrofurantoin increased. Conclusions: The treatment trends of antibiotics redeemed within five days from a cystitis diagnosis were similar to the national surveillance program of these antibiotics (not diagnosis linked). Fluoroquinolones were weakly associated with sociodemographic factors, which likely is only of historical relevance.

Antibiotic resistance of Escherichia coli urinary tract infections at a North Carolina community hospital: Comparison of rural and urban community type

OBJECTIVE

We aimed to identify differences in urinary E. coli resistance rates based on community type of patient residence (rural and urban).

METHODS

This cross-sectional study examined antibiotic resistance of E. coli isolates from 12,604 urine specimens at a North Carolina hospital between 2016 and 2018. Using multivariable logistic regression modeling, we investigated the association between resistance and community type, adjusting for patient age, gender, season, and setting of infection onset. Analyses were performed using SAS Version 9.3 (SAS Institute, Cary, NC) at alpha = 0.05.

RESULTS

Prevalence of resistance was highest for ampicillin (42.2%), ampicillin-sulbactam (24.7%), ciprofloxacin (21.8%), trimethoprim-sulfamethoxazole (SXT) (21.6%), and levofloxacin (21.4%). Rural compared to urban community type was significantly associated with resistance of E. coli urinary isolates to ciprofloxacin (adjusted odds ratio [aOR] = 1.29, 95% confidence interval [CI] = 1.16-1.43, P < .0001), levofloxacin (aOR = 1.28, 95% CI = 1.15-1.42, P < .0001), SXT (aOR = 1.15, 95% CI = 1.04-1.27, P = .01), and nitrofurantoin (aOR = 1.57, 95% CI = 1.13-2.17, P = .01).

CONCLUSIONS

Rural community type may influence urinary E. coli resistance to fluoroquinolones, SXT, and nitrofurantoin, indicating the need for antimicrobial stewardship interventions in medically underserved populations.

A global perspective on improving patient care in uncomplicated urinary tract infection: Expert consensus and practical guidance

BACKGROUND

Uncomplicated urinary tract infections (uUTIs) are a common problem in women. Management is mainly based on empirical prescribing, but there are concerns about overtreatment and antimicrobial resistance (AMR), especially in patients with recurrent uUTIs.

METHODS

A multidisciplinary panel of experts met to discuss diagnosis, treatment, prevention, guidelines, AMR, clinical trial design, and the impact of COVID-19 on clinical practice.

RESULTS

Symptoms remain the cornerstone of uUTI diagnosis, and urine culture is necessary only when empirical treatment fails, or rapid recurrence of symptoms or AMR is suspected. Specific antimicrobials are first-line therapy (typically nitrofurantoin, fosfomycin, trimethoprim-sulfamethoxazole, and pivmecillinam; dependent on availability and local resistance data). Fluoroquinolones are not first-line options for uUTIs due primarily to safety concerns, but also rising resistance rates. High-quality data to support most non-antimicrobial approaches are lacking. Local AMR data specific to community-acquired uUTIs are needed, but representative information is difficult to obtain; instead, identification of risk factors for AMR can provide a basis to guide empirical antimicrobial prescribing. The COVID-19 pandemic has impacted management of uUTIs in some countries and may have long-lasting implications for future models of care.

CONCLUSIONS

The management of uUTIs in women can be improved without increasing complexity, including simplified diagnosis, and empirical antimicrobial prescribing based on patient characteristics, including review of recent antimicrobial use and past pathogen resistance profiles, drug availability, and guidelines. Current data for non-antimicrobial approaches are limited. The influence of COVID-19 on telehealth could provide an opportunity to enhance patient care in the long term.

Efficacy of vaccination with StroVac for recurrent urinary tract infections in women: a comparative single-centre study

PURPOSE

To assess the efficacy of prophylaxis for urinary tract infections (UTI) in a two-year follow-up in women with StroVac compared to a therapy with Nitrofurantoin over three months.

MATERIALS AND METHODS

All patients with documented recurrent urinary tract infections (rUTI) were offered vaccination with StroVac or therapy with three months Nitrofurantoin 100 mg once daily for three months at patient's choice. Only patients with a follow-up of at least 24 months were included. All episodes with signs of UTI were documented and urine culture was performed. Success was defined as one or none UTI per 12 months, documented by urine culture. StroVac booster injection was offered 12 months after primary vaccination at patient's choice.

RESULTS

173 patients were included in this study, 124 in the StroVac group, 49 chose Nitrofuratoin. In the first 12 months, 86.8% of patients in the StroVac group and 91.8% in Nitrofurantoin group were successful (p = 0.22). Side effects were noted in 2.3% in the StroVac group causing discontinuation of therapy, whereas in the Nitrofurantoin group 18.4% stopped medication premature, mostly due to mild diarrhoea. In the second year 79.3% of patients in the StroVac group were still successful, most of them had undergone booster injection. In contrast, in the Nitrofurantoin group only 59.2% of patients were still successful (p = 0.03).

CONCLUSION

StroVac is an effective and lasting non-antibiotic prophylaxis for rUTI, easy to administer with low rates of adverse events and should be offered to patients with rUTI.

Recurrent Urinary Tract Infections: Unraveling the Complicated Environment of Uncomplicated rUTIs

Urinary tract infections (UTIs) are frequent in humans, affecting the upper and lower urinary tract. Present diagnosis relies on the positive culture of uropathogenic bacteria from urine and clinical markers of inflammation of the urinary tract. The bladder is constantly challenged by adverse environmental stimuli which influence urinary tract physiology, contributing to a dysbiotic environment. Simultaneously, pathogens are primed by environmental stressors such as antibiotics, favoring recurrent UTIs (rUTIs), resulting in chronic illness. Due to different confounders for UTI onset, a greater understanding of the fundamental environmental mechanisms and microbial ecology of the human urinary tract is required. Such advancements could promote the tandem translation of bench and computational studies for precision treatments and clinical management of UTIs. Therefore, there is an urgent need to understand the ecological interactions of the human urogenital microbial communities which precede rUTIs. This review aims to outline the mechanistic aspects of rUTI ecology underlying dysbiosis between both the human microbiome and host physiology which predisposes humans to rUTIs. By assessing the applications of next generation and systems level methods, we also recommend novel approaches to elucidate the systemic consequences of rUTIs which requires an integrated approach for successful treatment. To this end, we will provide an outlook towards the so-called 'uncomplicated environment of UTIs', a holistic and systems view that applies ecological principles to define patient-specific UTIs. This perspective illustrates the need to withdraw from traditional reductionist perspectives in infection biology and instead, a move towards a systems-view revolving around patient-specific pathophysiology during UTIs.

Antimicrobial susceptibility trends for urinary isolates in the veteran population

BACKGROUND

Guidance on empiric treatment for urinary tract infections (UTIs) is lacking for the male population which comprises much of the Veteran population in the United States. This study evaluated susceptibility trends in antimicrobials used for treatment of UTIs in the inpatient and outpatient Veteran population nationwide.

METHODS

Urine culture data was retrospectively obtained from Corporate Data Warehouse. All urine cultures from Veteran Health Administration patients 18 years of age or older who were treated at any VA health care center in the years 2009 and 2018 were eligible. Antibiograms were constructed for bacterial isolate susceptibility.

RESULTS

In 2009 and 2018 isolates from 54,788 and 58,983 Veterans were analyzed, respectively. Escherichia coli was the most common bacteria isolated. For ceftriaxone, E coli susceptibilities were relatively high but trended downward from 2009 to 2018. Common urinary pathogen susceptibilities remained low for fluoroquinolones and trimethoprim-sulfamethoxazole.

DISCUSSION

Empiric therapy for Veterans with UTIs should be based on local susceptibility patterns as previously recommended first-line agents have fallen out of favor due to increasing resistance rates.

CONCLUSIONS

Both inpatient and outpatient stewardship is needed to ensure appropriate treatment, as viable treatment options for UTIs are becoming increasingly limited.

Human carriage of cefotaxime-resistant Escherichia coli in North-East India: an analysis of STs and associated resistance mechanisms

OBJECTIVES

To determine the prevalence of Escherichia coli STs and associated resistance mechanisms carried by the community in North-East India.

METHODS

E. coli (108) were isolated from sewage collected from 19 sites across the city of Silchar by plating on MacConkey agar with/without selection (50 mg/L cefotaxime). Species identification was confirmed by MALDI-TOF MS for 82 isolates. Common resistance mechanisms were determined by WGS of pooled E. coli isolates. PFGE combined with specific probes determined the presence of common resistance mechanisms in all isolates. Phylotypes, multilocus STs, core-genome multilocus STs, resistance genes and virulence genes were determined by in silico analysis of 38 genomes.

RESULTS AND CONCLUSIONS

Analysis of isolates collected without selection (n=33) indicated that cefotaxime resistance in E. coli was 42% (14/33) and estimated meropenem resistance at 9%. The remaining 58% (19/33) were additionally susceptible to ampicillin, trimethoprim, ciprofloxacin and aminoglycosides. The most common ST among the cefotaxime-resistant E. coli was ST167 (29%), followed by ST410 (17%) and ST648 (10%). E. coli ST131 was absent from the collection. Sixty-three isolates were resistant to cefotaxime and harboured blaCTX-M-15 [54% (34/63)] or blaCMY-42 [46% (29/63)], of which 10% (6/63) harboured both genes. Carbapenem resistance was due to blaNDM-5, found in 10/63 cefotaxime-resistant isolates, and/or blaOXA-181, found in 4/63 isolates. NDM-5 was encoded by IncX3 and/or IncFII plasmids and CMY-42 was mostly encoded by IncI plasmids. NDM-5 appears to have replaced NDM-1 in this region and CMY-42 appears to be in the process of replacing CTX-M-15.

Characterization of cefotaxime-resistant urinary Escherichia coli from primary care in South-West England 2017-18

OBJECTIVES

Third-generation cephalosporin-resistant Escherichia coli from community-acquired urinary tract infections are increasingly reported worldwide. We sought to determine and characterize the mechanisms of cefotaxime resistance employed by urinary E. coli obtained from primary care, over 12 months, in Bristol and surrounding counties in South-West England.

METHODS

Cefalexin-resistant E. coli isolates were identified from GP-referred urine samples using disc susceptibility testing. Cefotaxime resistance was determined by subsequent plating onto MIC breakpoint plates. β-Lactamase genes were detected by PCR. WGS was performed on 225 isolates and analyses were performed using the Center for Genomic Epidemiology platform. Patient information provided by the referring general practices was reviewed.

RESULTS

Cefalexin-resistant E. coli (n=900) isolates were obtained from urines from 146 general practices. Following deduplication by patient approximately 69% (576/836) of isolates were cefotaxime resistant. WGS of 225 isolates identified that the most common cefotaxime-resistance mechanism was blaCTX-M carriage (185/225), followed by plasmid-mediated AmpCs (pAmpCs) (17/225), AmpC hyperproduction (13/225), ESBL blaSHV variants (6/225) or a combination of both blaCTX-M and pAmpC (4/225). Forty-four STs were identified, with ST131 representing 101/225 isolates, within which clade C2 was dominant (54/101). Ciprofloxacin resistance was observed in 128/225 (56.9%) of sequenced isolates, predominantly associated with fluoroquinolone-resistant clones ST131 and ST1193.

CONCLUSIONS

Most cefalexin-resistant E. coli isolates were cefotaxime resistant, predominantly caused by blaCTX-M carriage. The correlation between cefotaxime resistance and ciprofloxacin resistance was largely attributable to the high-risk pandemic clones ST131 and ST1193. Localized epidemiological data provide greater resolution than regional data and can be valuable for informing treatment choices in the primary care setting.

Draft Genome Sequences of Seven Extended-Spectrum β-Lactamase-Producing Escherichia coli Strains Isolated from New Zealand Waterways

Draft genomes of seven extended-spectrum β-lactamase (ESBL)-producing Escherichia coli strains recovered from New Zealand waterways are described. The mean genome size was 5.1 Mb, with 4,724 coding sequences. All genomes contained the ESBL gene bla_CTX-M, and one carried a plasmid-mediated AmpC gene, bla_CMY-2. A multidrug-resistant genotype was detected in three isolates.

Draft genomes of seven extended-spectrum β-lactamase (ESBL)-producing Escherichia coli strains recovered from New Zealand waterways are described. The mean genome size was 5.1 Mb, with 4,724 coding sequences. All genomes contained the ESBL gene bla_CTX-M, and one carried a plasmid-mediated AmpC gene, bla_CMY-2. A multidrug-resistant genotype was detected in three isolates.

Self-Limiting Mussel Inspired Thin Antifouling Coating with Broad-Spectrum Resistance to Biofilm Formation to Prevent Catheter-Associated Infection in Mouse and Porcine Models

Catheter-associated urinary tract infections (CAUTIs) are one of the most commonly occurring hospital-acquired infections. Current coating strategies to prevent catheter-associated biofilm formation are limited by their poor long-term efficiency and limited applicability to diverse materials. Here, the authors report a highly effective non-fouling coating with long-term biofilm prevention activity and is applicable to diverse catheters. The thin coating is lubricous, stable, highly uniform, and shows broad spectrum prevention of biofilm formation of nine different bacterial strains and prevents the migration of bacteria on catheter surface. The coating method is adapted to human-sized catheters (both intraluminal and extraluminal) and demonstrates long-term biofilm prevention activity over 30 days in challenging conditions. The coated catheters are tested in a mouse CAUTI model and demonstrate high efficiency in preventing bacterial colonization of both Gram-positive and Gram-negative bacteria. Furthermore, the coated human-sized Foley catheters are evaluated in a porcine CAUTI model and show consistent efficiency in reducing biofilm formation by Escherichia coli (E. coli) over 95%. The simplicity of the coating method, the ability to apply this coating on diverse materials, and the high efficiency in preventing bacterial adhesion increase the potential of this method for the development of next generation infection resistant medical devices.

Antimicrobial Susceptibility Patterns of Escherichia coli among Tunisian Outpatients with Community-Acquired Urinary Tract Infection (2012-2018)

Introduction

Community-acquired urinary tract infection is one of the most common reasons for consultation in everyday practice; it represents a major source of antibiotic consumption. Escherichia coli (E. coli) is the main pathogen incriminated.

Objective

The aim of this study was to evaluate antimicrobial susceptibility patterns of community-acquired uropathogenic E coli throughout a 7-year period.

Methodology

All strains of E. coli isolated from urine samples between January 1st 2012 and December 31st 2018 were included. Presence of ≥ 10³ CFU/ml in urine culture media was considered as significant for urinary tract infection. The identification of E. coli strains was realized using standard laboratory techniques. Antibiotic susceptibility testing was performed using the disk diffusion method according to the CA-SFM/ EUCAST criteria.

Results

A total of 1,335 E. coli strains were isolated. Overall susceptibility rates to antimicrobial agents were as follows: ampicillin 39.1%, amoxicillin-clavulanic acid 64.9%, cefotaxime 94.9%, trimethoprim/sulfamethox-azole 67.6%, ciprofloxacin 89.2%, ofloxacin 86.9%, amikacin 98.6%, gentamicin 93.9%, nitrofurantoin 97.6% and fosfomycin 99.3%. All isolates were susceptible to carbapenems. The frequency of extended spectrum beta-lactamases-producing E. coli strains was 4.7%. Susceptibility rates of E. coli for ampicillin, trimethoprim/sulfamethoxazole and amikacin remained relatively stable over the study period, whereas susceptibility to amoxicillin-clavulanic acid, cefotaxime and fluoroquinolones showed a 2-phase pattern. As for gentamicin, a continuous decrease in susceptibility rates was observed.

Conclusion

Antimicrobial susceptibility profiles of uropathogenic E. coli are constantly changing, due to modifications in the antibiogram interpretation criteria and antibiotic prescription habits. Rigorous surveillance of resistance rate is necessary to determine appropriate empirical treatment and limit the spread of multiresistant strains.

Polymicrobial interactions in the urinary tract: is the enemy of my enemy my friend?

The vast majority of research pertaining to urinary tract infection has focused on a single pathogen in isolation, and predominantly Escherichia coli. However, polymicrobial urine colonization and infection are prevalent in several patient populations, including individuals with urinary catheters. The progression from asymptomatic colonization to symptomatic infection and severe disease is likely shaped by interactions between traditional pathogens as well as constituents of the normal urinary microbiota. Recent studies have begun to experimentally dissect the contribution of polymicrobial interactions to disease outcomes in the urinary tract, including their role in development of antimicrobial-resistant biofilm communities, modulating the innate immune response, tissue damage, and sepsis. This review aims to summarize the epidemiology of polymicrobial urine colonization, provide an overview of common urinary tract pathogens, and present key microbe-microbe and host-microbe interactions that influence infection progression, persistence, and severity.

Carriage of Extended-Spectrum-Beta-Lactamase- and AmpC Beta-Lactamase-Producing Escherichia coli Strains from Humans and Pets in the Same Households

Extended-spectrum-beta-lactamase (ESBL)- or AmpC beta-lactamase (ACBL)-producing Escherichia coli bacteria are the most common cause of community-acquired multidrug-resistant urinary tract infections (UTIs) in New Zealand. The carriage of antimicrobial-resistant bacteria has been found in both people and pets from the same household; thus, the home environment may be a place where antimicrobial-resistant bacteria are shared between humans and pets. In this study, we sought to determine whether members (pets and people) of the households of human index cases with a UTI caused by an ESBL- or ACBL-producing E. coli strain also carried an ESBL- or ACBL-producing Enterobacteriaceae strain and, if so, whether it was a clonal match to the index case clinical strain. Index cases with a community-acquired UTI were recruited based on antimicrobial susceptibility testing of urine isolates. Fecal samples were collected from 18 non-index case people and 36 pets across 27 households. Eleven of the 27 households screened had non-index case household members (8/18 people and 5/36 animals) positive for ESBL- and/or ACBL-producing E. coli strains. Whole-genome sequence analysis of 125 E. coli isolates (including the clinical urine isolates) from these 11 households showed that within seven households, the same strain of ESBL-/ACBL-producing E. coli was cultured from both the index case and another person (5/11 households) or pet dog (2/11 households). These results suggest that transmission within the household may contribute to the community spread of ESBL- or ACBL-producing E. coliIMPORTANCEEnterobacteriaceae that produce extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases (ACBLs) are important pathogens and can cause community-acquired illnesses, such as urinary tract infections (UTIs). Fecal carriage of these resistant bacteria by companion animals may pose a risk for transmission to humans. Our work evaluated the sharing of ESBL- and ACBL-producing E. coli isolates between humans and companion animals. We found that in some households, dogs carried the same strain of ESBL-producing E. coli as the household member with a UTI. This suggests that transmission events between humans and animals (or vice versa) are likely occurring within the home environment and, therefore, the community as a whole. This is significant from a health perspective, when considering measures to minimize community transmission, and highlights that in order to manage community spread, we need to consider interventions at the household level.

[Rational antimicrobial therapy - recommendations for common infections]

Infectious diseases are a frequent reason for medical consultations both in the inpatient and outpatient setting. Inadequate management is associated with increased costs, morbidity and mortality. In times of rising antibiotic resistance rational therapy and antimicrobial stewardship are of utmost importance. While it is crucial to avoid excessively broad antimicrobial coverage and unnecessary therapies, serious conditions must be treated effectively. The article highlights common infections and gives recommendations for empiric and targeted antibiotic treatment. Discussed are pulmonary, abdominal, urinary tract, skin and soft tissue infections, as well as sepsis and staphylococcal bloodstream infections. The recommendations consider national and international guidelines, recent publications and current antimicrobial resistance in Germany.

Escherichia coli Resistance to Fluoroquinolones in Community-Acquired Uncomplicated Urinary Tract Infection in Women: a Systematic Review

Antibiotic resistance is a threat to public health, and uncomplicated urinary tract infections (uUTIs) are an example of this concern. This systematic review (International Prospective Register of Systematic Reviews [PROSPERO] ID: CRD42020156674) is the first to determine the prevalence of Escherichia coli resistance to fluoroquinolones in women with community-acquired uUTI. PubMed and Embase searches were conducted; 38 studies fulfilled eligibility criteria and were included in the systematic review. Within Europe, ciprofloxacin resistance in E. coli isolates varied between countries and increased in some from 2006 to 2008 and 2014 to 2016, specifically in the United Kingdom (0.5% to 15.3%), Germany (8.7% to 15.1%), and Spain (22.9% to 30.8%), although methodologies and settings were often not comparable. In Asia, there was a substantial increase in ciprofloxacin resistance during 2008 to 2014 from 25% to more than 40%. In North America, resistance to ciprofloxacin also increased between 2008 and 2017, from 4% to 12%. Data exploring different age groups did not show a consistent relationship with resistance, whereas two studies found that fluoroquinolone resistance was higher in postmenopausal women than premenopausal women. One study indicated a link between fluoroquinolone resistance and uUTI recurrence. These findings may have implications for the empirical treatment of uUTI with fluoroquinolones globally, but more data are needed to fully understand regional situations and impact patient management.