Oral gepotidacin versus nitrofurantoin in patients with uncomplicated urinary tract infection (EAGLE-2 and EAGLE-3): two randomised, controlled, double-blind, double-dummy, phase 3, non-inferiority trials.

BACKGROUND: Gepotidacin is a novel, bactericidal, first-in-class triazaacenaphthylene antibiotic that inhibits bacterial DNA replication by a distinct mechanism of action and a unique binding site, providing well balanced inhibition of two type II topoisomerase enzymes. Oral gepotidacin is under investigation to treat uncomplicated urinary tract infections. We aimed to compare the efficacy and safety of oral gepotidacin with that of nitrofurantoin in adolescent and adult female individuals with uncomplicated urinary tract infections. METHODS: EAGLE-2 and EAGLE-3 were phase 3, randomised, multicentre, double-blind, double-dummy, non-inferiority (10% margin) trials, in which patients were enrolled at 219 centres worldwide. Patients assigned female at birth, non-pregnant, aged 12 years or older, weighing 40 kg or more, with two or more symptoms of dysuria, frequency, urgency, or lower abdominal pain, and with evidence of urinary nitrite, pyuria, or both were eligible for inclusion. Patients were randomly assigned (1:1) centrally by interactive response technology to receive oral gepotidacin (1500 mg twice daily for 5 days) or oral nitrofurantoin (100 mg twice daily for 5 days), with randomisation stratified by age category and history of recurrent uncomplicated urinary tract infections. Patients, investigators, and the sponsor study team were masked to treatment assignment. The primary endpoint, therapeutic response (success or failure) at test-of-cure (ie, day 10-13), was evaluated in randomly assigned patients with nitrofurantoin-susceptible qualifying uropathogens (≥105 colony-forming units [CFU] per mL) and who received at least one dose of study treatment. Conforming to regulatory guidance, therapeutic success was defined as combined clinical success (ie, complete symptom resolution) and microbiological success (ie, reduction of qualifying uropathogens to <103 CFU/mL) without other systemic antimicrobial use. Safety analyses included patients who were randomly assigned and who received at least one dose of study treatment. The trials are registered with ClinicalTrials.gov, NCT04020341 (EAGLE-2) and NCT04187144 (EAGLE-3), and are completed. FINDINGS: Studies were undertaken from Oct 17, 2019, to Nov 30, 2022 (EAGLE-2), and from April 23, 2020, to Dec 1, 2022 (EAGLE-3). 1680 patients in EAGLE-2 and 1731 patients in EAGLE-3 were screened for eligibility, of whom 1531 and 1605 were randomly assigned, respectively (767 in the gepotidacin group and 764 in the nitrofurantoin group in EAGLE-2, and 805 in the gepotidacin group and 800 in the nitrofurantoin group in EAGLE-3). After an interim analysis, which was prospectively agreed as a protocol amendment, both studies were stopped for efficacy. Thus, the primary analysis population included only patients who, at the time of the interim analysis data cutoff, had the opportunity to reach the test-of-cure visit or were known to not have attained therapeutic success before the test-of-cure visit. In EAGLE-2, 162 (50·6%) of 320 patients assigned gepotidacin and 135 (47·0%) of 287 patients assigned nitrofurantoin had therapeutic success (adjusted difference 4·3%, 95% CI -3·6 to 12·1). In EAGLE-3, 162 (58·5%) of 277 patients assigned gepotidacin and 115 (43·6%) of 264 patients assigned nitrofurantoin had therapeutic success (adjusted difference 14·6%, 95% CI 6·4 to 22·8). Gepotidacin was non-inferior to nitrofurantoin in both studies and superior to nitrofurantoin in EAGLE-3. The most common adverse event with gepotidacin was diarrhoea (observed in 111 [14%] of 766 patients in EAGLE-2 and in 147 [18%] of 804 patients in EAGLE-3), whereas the most common adverse event with nitrofurantoin was nausea (in 29 [4%] of 760 patients in EAGLE-2 and in 35 [4%] of 798 patients in EAGLE-3). Cases were mostly mild or moderate. No life-threatening or fatal events occurred. INTERPRETATION: Gepotidacin is an efficacious oral antibiotic with acceptable safety and tolerability profiles. As a first-in-class investigational oral antibiotic with activity against common uropathogens, including clinically important drug-resistant phenotypes, gepotidacin has the potential to offer substantial benefit to patients. FUNDING: GSK and the US Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority.

In women with uncomplicated UTIs, gepotidacin was noninferior to nitrofurantoin for therapeutic response at 10 to 13 d.

SOURCE CITATION: Wagenlehner F, Perry CR, Hooton TM, et al. Oral gepotidacin versus nitrofurantoin in patients with uncomplicated urinary tract infection (EAGLE-2 and EAGLE-3): two randomised, controlled, double-blind, double-dummy, phase 3, non-inferiority trials. Lancet. 2024;403:741-755. 38342126.

Pervasive Selection for Clinically Relevant Resistance and Media Adaptive Mutations at Very Low Antibiotic Concentrations.

Experimental evolution studies have shown that weak antibiotic selective pressures (i.e., when the antibiotic concentrations are far below the minimum inhibitory concentration, MIC) can select resistant mutants, raising several unanswered questions. First, what are the lowest antibiotic concentrations at which selection for de novo resistance mutations can occur? Second, with weak antibiotic selections, which other types of adaptive mutations unrelated to the antibiotic selective pressure are concurrently enriched? Third, are the mutations selected under laboratory settings at subMIC also observed in clinical isolates? We addressed these questions using Escherichia coli populations evolving at subMICs in the presence of either of four clinically used antibiotics: fosfomycin, nitrofurantoin, tetracycline, and ciprofloxacin. Antibiotic resistance evolution was investigated at concentrations ranging from 1/4th to 1/2000th of the MIC of the susceptible strain (MICsusceptible). Our results show that evolution was rapid across all the antibiotics tested, and selection for fosfomycin- and nitrofurantoin-resistant mutants was observed at a concentration as low as 1/2000th of MICsusceptible. Several of the evolved resistant mutants showed increased growth yield and exponential growth rates, and outcompeted the susceptible ancestral strain in the absence of antibiotics as well, suggesting that adaptation to the growth environment occurred in parallel with the selection for resistance. Genomic analysis of the resistant mutants showed that several of the mutations selected under these conditions are also found in clinical isolates, demonstrating that experimental evolution at very low antibiotic levels can help in identifying novel mutations that contribute to bacterial adaptation during subMIC exposure in real-life settings.

Predicting Antibiotic Susceptibility Among Patients With Recurrent Urinary Tract Infection Using a Prior Culture.

PURPOSE: Recurrent cystitis guidelines recommend relying on a local antibiogram or prior urine culture to guide empirical prescribing, yet little data exist to quantify the predictive value of a prior culture. We constructed a urinary antibiogram and evaluated test metrics (sensitivity, specificity, and Bayes' positive and negative predictive values) of a prior gram-negative organism on predicting subsequent resistance or susceptibility among patients with uncomplicated, recurrent cystitis. MATERIALS AND METHODS: We performed a retrospective database study of adults with recurrent, uncomplicated cystitis (cystitis occurring 2 times in 6 months or 3 times in 12 months) from urology or primary care clinics between November 1, 2016, and December 31, 2018. We excluded pregnant females, patients with complicated cystitis, or pyelonephritis. Test metrics were calculated between sequential, paired cultures using standard formulas. RESULTS: We included 597 visits from 232 unique patients wherein 310 (51.2%) visits had a urine culture and 165 had gram-negative uropathogens isolated. Patients with gram-negative uropathogens were mostly females (97%), with a median age of 58.5 years. Our antibiogram found 38.0%, 27.9%, and 5.5% of Escherichia coli isolates had resistance to trimethoprim-sulfamethoxazole, ciprofloxacin, and nitrofurantoin, respectively. Prior cultures (within 2 years) had good predictive value for detecting future susceptibility to first-line agents nitrofurantoin (0.85) and trimethoprim-sulfamethoxazole (0.78) and excellent predictive values (≥0.90) for cefepime, ceftriaxone, cefuroxime, ciprofloxacin, levofloxacin, gentamicin, tobramycin, piperacillin-tazobactam, and imipenem. CONCLUSIONS: Considerable antibiotic resistance was detected among E coli isolates in patients with recurrent, uncomplicated cystitis. Using a prior culture as a guide can enhance the probability of selecting an effective empirical agent.

A rare urinary tract infection of multidrug-resistant Chryseobacterium urinae sp. nov. isolated from a diabetic, non-catheterized patient.

Chryseobacterium demonstrates a diverse environmental presence and a significant pathogenic potential across various ecosystems. This clinical case showcases a rare instance of bacterial infection in a 75-year-old male with untreated diabetes and recurrent urinary tract infections (UTIs). The patient presented symptoms of abdominal pain, burning urination, fever, and an elevated eosinophil count. A subsequent urine culture identified a Chryseobacterium-related bacterium as the causative agent, exhibiting sensitivity to piperacillin/tazobactam, trimethoprim/sulfamethoxazole, and nitrofurantoin, which led to successful treatment using oral nitrofurantoin. Analysis of the 16S rRNA gene sequence of APV-1T revealed a close relationship of 98.2% similarity to Chryseobacterium gambrini strain 5-1St1aT (AM232810). Furthermore, comparative genome analysis, incorporating Average Nucleotide Identity (ANI), Digital DNA-DNA Hybridization (dDDH) values, and comprehensive phylogenetic assessments utilizing 16S rRNA gene sequences, core genes, and amino acid sequences of core proteins, highlighted the unique phylogenetic positioning of APV-1T within the Chryseobacterium genus. Distinct carbon utilization and assimilation patterns, along with major fatty acid content, set APV-1T apart from C. gambrini strain 5-1St1aT. These findings, encompassing phenotypic, genotypic, and chemotaxonomic characteristics, strongly support the proposal of a novel species named Chryseobacterium urinae sp. nov., with APV-1T designated as the type strain (= MCC 50690 = JCM 36476). Despite its successful treatment, the strain displayed resistance to multiple antibiotics. Genomic analysis further unveiled core-conserved genes, strain-specific clusters, and genes associated with antibiotic resistance and virulence. This report underscores the vital importance of elucidating susceptibility patterns of rare pathogens like Chryseobacterium, particularly in immunocompromised individuals. It advocates for further analyses to understand the functional significance of identified genes and their implications in treatment and pathogenesis.

Antibiotics efficacy in clinical and microbiological cure of uncomplicated urinary tract infection: a systematic review and network meta-analysis.

PURPOSE: Fosfomycin has been used more frequently in managing uncomplicated urinary tract infections (UTIs) due to decreased compliance and increased multidrug-resistant bacteria. The aim of this network meta-analysis was to assess the efficacy of Fosfomycin compared to Nitrofurantoin, Trimethoprim-Sulfamethoxazole (TMP-SMX), and Ciprofloxacin in terms of clinical and microbiological cure alongside with other measurements. MATERIALS AND METHODS: We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL). We included randomized control trials (RCTs) with uncomplicated UTI patients who received Fosfomycin, Nitrofurantoin, TMP-SMX, or Ciprofloxacin and reported the clinical or microbiological cure. We used Cochrane Risk of Bias Assessment Tool to assess the included studies' quality. R-software was used for all statistical analysis. We ranked all antibiotics using the netrank function which yielded P scores. Frequentist network meta-analysis was used to assess the efficacy of all outcomes. RESULTS: We included 13 RCTs with a total number of 3856 patients that showed Fosfomycin ranked the highest among the other antibiotics with respect to clinical cure (P-score = 0.99) and microbiological cure (P-score = 0.99) while Ciprofloxacin ranked the lowest (P-score = 0.11 and 0.02, respectively). Moreover, Ciprofloxacin yielded the highest relapse rate (P-score = 1), whereas TMP-SMX had the lowest relapse rate (P-score = 0.07). As for the adverse events, Ciprofloxacin demonstrated the highest adverse events as opposed to Fosfomycin (P-score = 0.98 and 0.05, respectively). CONCLUSION: The network meta-analysis demonstrated that Fosfomycin is the most effective antibiotic in treating uncomplicated UTIs with respect to clinical cure, microbiological cure, and adverse events profile.

In vitro antitrypanosomal activity of synthesized nitrofurantoin-triazole hybrids against Trypanosoma species causing animal African trypanosomosis.

Animal African trypanosomosis (AAT) is a disease caused by Trypanosoma brucei brucei, T. vivax, T. evansi and T. congolense which are mainly transmitted by tsetse flies (maybe the family/genus scientific name for the tsetse flies here?). Synthetic trypanocidal drugs are used to control AAT but have reduced efficacy due to emergence of drug resistant trypanosomes. Therefore, there is a need for the continued development of new safe and effective drugs. The aim of this study was to evaluate the in vitro anti-trypanosomal activity of novel nitrofurantoin compounds against trypanosomes (Trypanosoma brucei brucei, T. evansi and T. congolense) causing AAT. This study assessed previously synthesized nineteen nitrofurantoin-triazole (NFT-TZ) hybrids against animal trypanosomes and evaluated their cytotoxicity using Madin-Darby bovine kidney cells. The n-alkyl sub-series hybrids, 8 (IC50 0.09 ± 0.02 µM; SI 686.45) and 9 (IC50 0.07 ± 0.04 µM; SI 849.31) had the highest anti-trypanosomal activity against T. b. brucei. On the contrary, the nonyl 6 (IC50 0.12 ± 0.06 µM; SI 504.57) and nitrobenzyl 18 (IC50 0.11 ± 0.03 µM; SI 211.07) displayed the highest trypanocidal activity against T. evansi. The nonyl hybrid 6 (IC50 0.02 ± 0.01 µM; SI 6328.76) was also detected alongside the undecyl 8 (IC50 0.02 ± 0.01 µM; SI 3454.36) and 3-bromobenzyl 19 (IC50 0.02 ± 0.01 µM; SI 2360.41) as the most potent hybrids against T. congolense. These hybrids had weak toxicity effects on the mammalian cells and highly selective submicromolar antiparasitic action efficacy directed towards the trypanosomes, hence they can be regarded as potential trypanocidal leads for further in vivo investigation.

Acute Uncomplicated UTIs in Adults: Rapid Evidence Review.

An acute uncomplicated urinary tract infection (UTI) is a bacterial infection of the lower urinary tract with no sign of systemic illness or pyelonephritis in a noncatheterized, nonpregnant adult with no urologic abnormalities or immunocompromise. In women, a self-diagnosis of a UTI with the presence of typical symptoms (e.g., frequency, urgency, dysuria/burning sensation, nocturia, suprapubic pain), without vaginal discharge, is accurate enough to diagnose an uncomplicated UTI without further testing. Urine culture and susceptibility testing should be reserved for women with recurrent infection, treatment failure, history of resistant isolates, or atypical presentation to make a definitive diagnosis and guide antibiotic selection. First-line antibiotics include nitrofurantoin for five days, fosfomycin in a single dose, trimethoprim for three days, or trimethoprim/sulfamethoxazole for three days. Symptomatic treatment with nonsteroidal anti-inflammatory drugs and delayed antibiotics may be considered because the risk of complications is low. Increased fluids, intake of cranberry products, and methenamine hippurate can prevent recurrent infections. Antibiotic prophylaxis is also effective in preventing recurrence but has a risk of adverse effects and antimicrobial resistance. Men with lower UTI symptoms should always receive antibiotics, with urine culture and susceptibility results guiding the antibiotic choice. Clinicians should also consider the possibility of urethritis and prostatitis in men with UTI symptoms. First-line antibiotics for men with uncomplicated UTI include trimethoprim, trimethoprim/sulfamethoxazole, and nitrofurantoin for seven days. Uncomplicated UTIs in nonfrail women and men 65 years and older with no relevant comorbidities also necessitate a urine culture with susceptibility testing to adjust the antibiotic choice after initial empiric treatment; first-line antibiotics and treatment durations do not differ from those recommended for younger adults.

Antibiogram data of urinary tract infection in spinal cord injury patients in an outpatient setting.

OBJECTIVES: To establish antibiogram data for patients with spinal cord injury (SCI) that would help differentiate the organisms commonly present depending on the voiding method and antibiotic sensitivity for empirical treatment. METHODS: A total of 499 urine culture results were obtained from 151 SCI patients with symptomatic urinary tract infection (UTI) with significant bacteriuria and pyuria with more than 10 white blood cells per high power field. The voiding method was categorized as follows: self-intermittent catheterization (SIC), suprapubic catheter (SPC), Foley catheter, condom catheter, or voiding freely. RESULTS: The demographic data were as follows: male, n=124 (82.2%); female, n=27 (17.8%); mean age, 39; paraplegic n=105 (69.5%); and tetraplegic, n=45 (29.8%). The SIC was the most common voiding method (n=64, 42.3%), followed by Foley catheter (n=39, 25.8%). Escherichia coli was the most common organism overall (29%) and more frequent in patients using SIC as the voiding method. Proteus mirabilis was present more frequently in patients using SPC (33%), and Klebsiella pneumoniae in voiding freely cultures (30%). Antibiotic sensitivity was as follows Gentamicin (44.1%), Nitrofurantoin (39.1%), Augmentin (33.5%), and Ciprofloxacin (31.5%). CONCLUSION: Increased preference of the local population to foley catheter as a voiding method which needs to be investigated more. The type of voiding methods in patients with SCI results in different common causative organisms of UTI. Ciprofloxacin resistance profile increased overall except in patients voiding with SPC. Nitrofurantoin is the most overall sensitive oral antibiotic in our sample followed by Augmentin then Cefuroxime.

Clinical features, outcomes, and HLA risk factors associated with nitrofurantoin-induced liver injury.

BACKGROUND & AIMS: Nitrofurantoin (NTF) is widely used for the treatment (short-term) and prevention (long-term) of urinary tract infections. We aimed to describe the clinical characteristics, outcomes, and HLA risk factors for NTF-induced liver injury (NTF-DILI) among individuals enrolled in the Drug Induced Liver Injury Network (DILIN). METHODS: Seventy-eight individuals with definite, highly likely, or probable NTF-DILI were enrolled into DILIN studies between 2004-2020. HLA alleles were compared between NTF-DILI and three control groups: population (n = 14,001), idiopathic autoimmune hepatitis (n = 231), and non-NTF DILI (n = 661). RESULTS: Liver injury was hepatocellular in 69% and icteric in 55%. AST > ALT was more common in the 44 long-exposure (≥1 year) NTF-DILI cases than in the 18 short (≤7 days) and 16 intermediate (>7 to <365 days) exposure cases (73% vs. 33% vs. 50%, respectively, p = 0.018), as was ANA or SMA positivity (91% vs. 44% vs. 50%, respectively, p <0.001), and corticosteroid use (61% vs. 27% vs. 44%, respectively, p = 0.06). In long-term NTF-DILI, bridging fibrosis, nodularity or cirrhosis, or clinical and imaging evidence for cirrhosis were present in 38%, with massive or sub-massive necrosis in 20%. No one in the short-term exposure group died or underwent transplantation, whereas 7 (12%) patients from the other groups died or underwent transplantation. After covariate adjustments, HLA-DRB1∗11:04 was significantly more frequent in NTF-DILI compared to population controls (odds ratio [OR] 4.29, p = 1.15 × 10-4), idiopathic autoimmune hepatitis (OR 11.77, p = 7.76 × 10-5), and non-NTF DILI (OR 3.34, p = 0.003). CONCLUSION: NTF-DILI can result in parenchymal necrosis, bridging fibrosis, cirrhosis, and death or liver transplantation, especially with long-term exposure, and is associated with HLA-DRB1∗11:04. To mitigate against serious liver injury associated with NTF, regulators should revise the prescribing information and consider other mitigation strategies. IMPACT AND IMPLICATIONS: Nitrofurantoin is a recognized cause of drug-induced liver injury (DILI). In this study consisting of a large cohort of well-phenotyped individuals with nitrofurantoin-induced liver injury, two distinct patterns of liver injury were identified: liver injury associated with short-term exposure, which is generally self-limiting, and liver injury associated with long-term exposure, which can lead to advanced fibrosis, cirrhosis and liver failure. HLA DRB1∗11:04 is a risk factor for liver injury due to long-term nitrofurantoin exposure. Our findings are important for regulators as well as physicians prescribing and pharmacists dispensing nitrofurantoin.

Nomenclature, diagnosis and management of drug-induced autoimmune-like hepatitis (DI-ALH): An expert opinion meeting report.

Drug-induced liver injury (DILI) can mimic almost all other liver disorders. A phenotype increasingly ascribed to drugs is autoimmune-like hepatitis (ALH). This article summarises the major topics discussed at a joint International Conference held between the Drug-Induced Liver Injury consortium and the International Autoimmune Hepatitis Group. DI-ALH is a liver injury with laboratory and/or histological features that may be indistinguishable from those of autoimmune hepatitis (AIH). Previous studies have revealed that patients with DI-ALH and those with idiopathic AIH have very similar clinical, biochemical, immunological and histological features. Differentiating DI-ALH from AIH is important as patients with DI-ALH rarely require long-term immunosuppression and the condition often resolves spontaneously after withdrawal of the implicated drug, whereas patients with AIH mostly require long-term immunosuppression. Therefore, revision of the diagnosis on long-term follow-up may be necessary in some cases. More than 40 different drugs including nitrofurantoin, methyldopa, hydralazine, minocycline, infliximab, herbal and dietary supplements (such as Khat and Tinospora cordifolia) have been implicated in DI-ALH. Understanding of DI-ALH is limited by the lack of specific markers of the disease that could allow for a precise diagnosis, while there is similarly no single feature which is diagnostic of AIH. We propose a management algorithm for patients with liver injury and an autoimmune phenotype. There is an urgent need to prospectively evaluate patients with DI-ALH systematically to enable definitive characterisation of this condition.

Antimicrobial Resistance Studies Using Raman Spectroscopy on Clinically Relevant Bacterial Strains.

There has been a steep rise in the emergence of antibiotic-resistant bacteria in the past few years. A timely diagnosis can help in initiating appropriate antibiotic therapy. However, conventional techniques for diagnosing antibiotic resistance are time-consuming and labor-intensive. Therefore, we investigated the potential of Raman spectroscopy as a rapid surveillance technology for tracking the emergence of antibiotic resistance. In this study, we used Raman spectroscopy to differentiate clinical isolates of antibiotic-resistant and -sensitive bacteria of Escherichia coli, Acinetobacter baumannii, and Enterobacter species. The spectra were collected with or without exposure to various antibiotics (ciprofloxacin, gentamicin, meropenem, and nitrofurantoin), each having a distinct mechanism of action. Ciprofloxacin- and meropenem-treated sensitive strains showed a decrease in the intensity of Raman bands associated with DNA (667, 724, 785, 1378, 1480, and 1575 cm-1) and proteins (640 and 1662 cm-1), coupled with an increase in the intensity of lipid bands (891, 960, and 1445 cm-1). Gentamicin- and nitrofurantoin-treated sensitive strains showed an increase in the intensity of nucleic acid bands (668, 724, 780, 810, 1378, 1480, and 1575 cm-1) while a decrease in the intensity of protein bands (640, 1003, 1606, and 1662 cm-1) and the lipid band (1445 cm-1). The Raman spectral changes observed in the antibiotic-resistant strains were opposite to that of antibiotic-sensitive strains. The Raman spectral data correlated well with the antimicrobial susceptibility test results. The Raman spectral dataset was used for partial least-squares (PLS) analysis to validate the biomarkers obtained from the univariate analysis. Overall, this study showcases the potential of Raman spectroscopy for detecting antibiotic-resistant and -sensitive bacteria.

Exploring the in situ evolution of nitrofurantoin resistance in clinically derived uropathogenic Escherichia coli isolates.

BACKGROUND: Nitrofurantoin has been re-introduced as a first-choice antibiotic to treat uncomplicated acute urinary tract infections in England and Wales. Highly effective against common uropathogens such as Escherichia coli, its use is accompanied by a low incidence (<10%) of antimicrobial resistance. Resistance to nitrofurantoin is predominantly via the acquisition of loss-of-function, step-wise mutations in the nitroreductase genes nfsA and nfsB. OBJECTIVE: To explore the in situ evolution of NitR in E. coli isolates from 17 patients participating in AnTIC, a 12-month open label randomized controlled trial assessing the efficacy of antibiotic prophylaxis in reducing urinary tract infections (UTIs) incidence in clean intermittent self-catheterizing patients. METHODS: The investigation of NitR evolution in E. coli used general microbiology techniques and genetics to model known NitR mutations in NitSE. coli strains. RESULTS: Growth rate analysis identified a 2%-10% slower doubling time for nitrofurantoin resistant strains: NitS: 20.8 ±â€Š0.7 min compared to NitR: 23 ±â€Š0.8 min. Statistically, these data indicated no fitness advantage of evolved strains compared to the sensitive predecessor (P-value = 0.13). Genetic manipulation of E. coli to mimic NitR evolution, supported no fitness advantage (P-value = 0.22). In contrast, data argued that a first-step mutant gained a selective advantage, at sub-MIC (4-8 mg/L) nitrofurantoin concentrations. CONCLUSION: Correlation of these findings to nitrofurantoin pharmacokinetic data suggests that the low incidence of E. coli NitR, within the community, is driven by urine-based nitrofurantoin concentrations that selectively inhibit the growth of E. coli strains carrying the key first-step loss-of-function mutation.

Nitrofurantoin: what is the evidence for current UK guidance?

Three days of nitrofurantoin at 100 mg twice daily is recommended as first-line treatment for uncomplicated urinary tract infection (UTI) in evidence-based guidelines across the UK. A review of international guidelines shows that the evidence base has been interpreted in very different ways. UK guidelines are unusual in promoting short (3 day) courses, and we find little direct evidence to support this. Although 'short' courses of antibiotics for other agents may provide optimum balance between providing effective treatment whilst reducing selective pressure driving resistance amongst colonizing microbial flora, it remains unclear that course lengths can be extrapolated to nitrofurantoin. Three days of nitrofurantoin may indeed be a useful intervention in a large group of patients. However, without supporting evidence and because clinical response should be expected to vary widely, it is unclear that establishing and promoting an antibiotic duration for UTI is the best approach to optimizing prescribing in this important area.

Antibacterial effect of vitamin C against uropathogenic E. coli in vitro and in vivo.

BACKGROUND: Resistance to antibiotics has increased steadily over time, thus there is a pressing need for safer alternatives to antibiotics. Current study aims to evaluate the influence of vitamin C as an antibacterial and anti-biofilm agent against uropathogenic E. coli (UPEC) strains. The expression of beta-lactamases and biofilm encoding genes among E. coli isolates before and after treating the isolates with sub MIC of vitamin C was analyzed by Real-time PCR. The in vivo assessment of the antibacterial and anti-biofilm effects of vitamin C against uropathogenic E. coli strains was done using a urinary tract infection (UTI) rat model. RESULTS: The effective concentration of vitamin C that could inhibit the growth of most study isolates (70%) was 1.25 mg/ml. Vitamin C showed a synergistic effect with most of the studied antibiotics; no antagonistic effect was detected at all. Vitamin C showed an excellent anti-biofilm effect against studied isolates, where 43 biofilm-producing isolates were converted to non-biofilm at a concentration of 0.312 mg/ml. The expression levels of most studied genes were down-regulated after treatment of E. coli isolates with vitamin C. In vivo assessment of vitamin C in treating UTIs showed that vitamin C has a rapid curative effect as the comparable antibiotic. Administration of both vitamin C and nitrofurantoin at a lower dose for treatment of UTI in rats had a better effect. CONCLUSION: Vitamin C as an antibacterial and anti-biofilm agent either alone or in combination with antibiotics could markedly improve UTI in experimental rats.

CombiANT: Antibiotic interaction testing made easy.

Antibiotic combination therapies are important for the efficient treatment of many types of infections, including those caused by antibiotic-resistant pathogens. Combination treatment strategies are typically used under the assumption that synergies are conserved across species and strains, even though recent results show that the combined treatment effect is determined by specific drug-strain interactions that can vary extensively and unpredictably, both between and within bacterial species. To address this problem, we present a new method in which antibiotic synergy is rapidly quantified on a case-by-case basis, allowing for improved combination therapy. The novel CombiANT methodology consists of a 3D-printed agar plate insert that produces defined diffusion landscapes of 3 antibiotics, permitting synergy quantification between all 3 antibiotic pairs with a single test. Automated image analysis yields fractional inhibitory concentration indices (FICis) with high accuracy and precision. A technical validation with 3 major pathogens, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, showed equivalent performance to checkerboard methodology, with the advantage of strongly reduced assay complexity and costs for CombiANT. A synergy screening of 10 antibiotic combinations for 12 E. coli urinary tract infection (UTI) clinical isolates illustrates the need for refined combination treatment strategies. For example, combinations of trimethoprim (TMP) + nitrofurantoin (NIT) and TMP + mecillinam (MEC) showed synergy, but only for certain individual isolates, whereas MEC + NIT combinations showed antagonistic interactions across all tested strains. These data suggest that the CombiANT methodology could allow personalized clinical synergy testing and large-scale screening. We anticipate that CombiANT will greatly facilitate clinical and basic research of antibiotic synergy.

Molecular mechanisms of collateral sensitivity to the antibiotic nitrofurantoin.

Antibiotic resistance increasingly limits the success of antibiotic treatments, and physicians require new ways to achieve efficient treatment despite resistance. Resistance mechanisms against a specific antibiotic class frequently confer increased susceptibility to other antibiotic classes, a phenomenon designated collateral sensitivity (CS). An informed switch of antibiotic may thus enable the efficient treatment of resistant strains. CS occurs in many pathogens, but the mechanisms that generate hypersusceptibility are largely unknown. We identified several molecular mechanisms of CS against the antibiotic nitrofurantoin (NIT). Mutants that are resistant against tigecycline (tetracycline), mecillinam (ß-lactam), and protamine (antimicrobial peptide) all show CS against NIT. Their hypersusceptibility is explained by the overexpression of nitroreductase enzymes combined with increased drug uptake rates, or increased drug toxicity. Increased toxicity occurs through interference of the native drug-response system for NIT, the SOS response, with growth. A mechanistic understanding of CS will help to develop drug switches that combat resistance.

A new framework for advancing in drug-induced liver injury research. The Prospective European DILI Registry.

BACKGROUND & AIMS: No multi-national prospective study of drug-induced liver injury (DILI) has originated in Europe. The design of a prospective European DILI registry, clinical features and short-term outcomes of the cases and controls is reported. METHODS: Patients with suspected DILI were prospectively enrolled in the United Kingdom, Spain, Germany, Switzerland, Portugal and Iceland, 2016-2021. DILI cases or non-DILI acute liver injury controls following causality assessment were enrolled. RESULTS: Of 446 adjudicated patients, 246 DILI patients and 100 had acute liver injury due to other aetiologies, mostly autoimmune hepatitis (n = 42) and viral hepatitis (n = 34). DILI patients (mean age 56 years), 57% women, 60% with jaundice and 3.6% had pre-existing liver disease. DILI cases and non-DILI acute liver injury controls had similar demographics, clinical features and outcomes. A single agent was implicated in 199 (81%) DILI cases. Amoxicillin-clavulanate, flucloxacillin, atorvastatin, nivolumab/ipilimumab, infliximab and nitrofurantoin were the most commonly implicated drugs. Multiple conventional medications were implicated in 37 (15%) and 18 cases were caused by herbal and dietary supplements. The most common single causative drug classes were antibacterials (40%) and antineoplastic/immunomodulating agents (27%). Overall, 13 (5.3%) had drug-induced autoimmune-like hepatitis due to nitrofurantoin, methyldopa, infliximab, methylprednisolone and minocycline. Only six (2.4%) DILI patients died (50% had liver-related death), and another six received liver transplantation. CONCLUSIONS: In this first multi-national European prospective DILI Registry study, antibacterials were the most commonly implicated medications, whereas antineoplastic and immunomodulating agents accounted for higher proportion of DILI than previously described. This European initiative provides an important opportunity to advance the study on DILI.

Empiric versus culture-based antibiotic therapy for UTIs in menopausal women.

PURPOSE: To assess the benefits and risks associated with empiric prescription of antibiotic therapy for treatment of a urinary tract infection (UTI). METHODS: Following IRB approval menopausal women presenting with a symptomatic UTI to a single urology clinic were prospectively assigned to one of the two treatment groups based on day of presentation: culture-based treatment (CB) (Monday, Tuesday, Wednesday) or empiric treatment (ET) (Thursday, Friday) and started on nitrofurantoin (NF) pending culture results. Both groups were contacted at 7 and 14 days following treatment. Side effects and answers to a standardized questionnaire (UTISA) were recorded. Success was defined as a total UTISA score < 3. Any NF retreatment, use of another antibiotic therapy, or extension of the original antibiotic course was considered treatment failures. RESULTS: From July 2020 to March 2022, 65 women with 80 UTI events were included in the study, with CB treatment used for 60 UTIs and ET used for 23 UTIs. At 7 days after start of treatment, questionnaire failure rate was 44% (20/45) for the CB group and 16% (3/19) for the ET group (P = 0.076). At 14 days following start of treatment, questionnaire failure rate was 31% (13/42) for the CB group and 17% (3/18) for the ET group (P = 0.3). In the ET group, 11% of cultures were found to be resistant to NF. CONCLUSION: Outcomes for the empiric treatment of uncomplicated UTI with NF at both 7 and 14 days are not significantly different than outcomes with culture-based treatment.

Mechanistic Insight of Polymer Effects on the Kinetic of Solution-Mediated Phase Transformation of Nitrofurantoin Anhydrate to Monohydrate.

PURPOSE: Nitrofurantoin is an effective antibacterial drug for the treatment of lower urinary tract infection. However, the anhydrate form can easily transform to the less soluble hydrate form (monohydrate) during dissolution, resulting in a reduction of dissolution rate and oral bioavailability. Therefore, inhibition of phase transformation is vital to stabilize the quality of drugs. METHODS: In this work, the potential of polyethylene glycol (PEG 8000), polyvinyl pyrrolidone (PVP K30), poloxamer 188 and hydroxypropyl methylcellulose (HPMC) to inhibit the hydration of nitrofurantoin during dissolution was investigated by experimental and simulation approaches. RESULTS: The rates of phase transformation were decreased in the presence of PEG 8000 and poloxamer 188, and PVP K30 and HPMC completely inhibited the phase transformation of anhydrate. The abundant hydrogen bond donor and acceptor groups of PVP and HPMC may easily establish intermolecular interactions with nitrofurantoin molecules, accounting for stronger inhibition of nucleation. Besides, the molecular dynamic simulation further indicated the formation of more extensive interactions between PVP K30 (or HPMC) and the (111) face of monohydrate, suggesting that the strong absorption of polymers on the surface and thus block the sites for incorporation of new growth. CONCLUSION: This study provides a mechanistic insight into the inhibition of nitrofurantoin hydration by polymeric additives, which helps design formulations and improve the physical stability of anhydrate.