New paradigms on antibiotic recommendations for community-acquired infections in Spain

Over the last years, the susceptibility activity of the most common microorganisms causing community-acquired infections has significantly changed in Spain. Based on the susceptibility rates of Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, Escherichia coli, and Klebsiella pneumoniae collected from outpatients aged 15 or older with symptoms of respiratory or urinary tract infections in several Microbiology Departments in Catalonia in 2021, penicillin V should be first choice for most respiratory tract infections, amoxicillin and clavulanate for chronic obstructive pulmonary disease exacerbations and a single dose of fosfomycin or a short-course nitrofurantoin should remain first-line treatments for uncomplicated urinary tract infections. Updated information on antimicrobial resistance for general practitioners is crucial for achieving appropriate empirical management of the most common infections by promoting more rational antibiotic use.

Diagnostic and Therapeutic Management of Urinary Tract Infections in Catalonia, Spain: Protocol for an Observational Cohort Study

BACKGROUND

Antibiotic resistance is an individual and public health problem; multidrug-resistant infections could cause an estimated 10 million deaths worldwide by 2050. Unnecessary use of antimicrobials is the most important cause of resistance generation in the community, and an estimated 80% of antimicrobials are prescribed in primary health care, frequently for urinary tract infections (UTIs).

OBJECTIVE

This paper presents the protocol for the first phase of the Urinary Tract Infections in Catalonia (Infeccions del tracte urinari a Catalunya) project. We aim to examine the epidemiology of the different types of UTIs in Catalonia (an autonomous community in Spain) and their diagnostic and therapeutic management by health professionals. Furthermore, we aim to evaluate the correlation between types and total consumption of antibiotics for recurrent UTIs in 2 cohorts of women with the presence and severity of infectious complications of urological origin, especially pyelonephritis and sepsis, and 2 potentially serious infections: pneumonia and COVID-19.

METHODS

The study is a population-based observational cohort study including adults with a diagnosis of UTI registered in the Information System for the Development of Research in Primary Care (in Catalan: Sistema d'informació per al desenvolupament de la investigació en atenció primària), the Minimum Basic Data Sets of Hospital Discharges and Emergency Departments (in Catalan: Conjunt mínim bàsic de dades a l'hospitalització d'aguts i d'atenció urgent), and data from the Hospital Dispensing Medicines Register (in Catalan: Medicació hospitalària de dispensació ambulatòria) of Catalonia from the period between 2012 and 2021. We will evaluate the variables obtained from the databases to analyze the proportion of different types of UTIs, the percentage of adequate antibiotic treatments prescribed or received for recurrent UTIs according to the national guidelines, and the proportion of UTIs with complications.

RESULTS

We expect to describe the epidemiology of UTIs in Catalonia from 2012 to 2021, as well as describe the diagnostic and therapeutic management of UTIs by health professionals.

CONCLUSIONS

We expect to find a high percentage of UTI cases with inadequate management according to the national guidelines, considering that on many occasions UTIs are treated with second- or third-line antibiotic therapies with a preference for the longest regimens. Furthermore, the use of antibiotic suppressive therapies, or prophylaxis, in recurrent UTIs will likely be highly variable. Moreover, we aim to determine whether women with recurrent UTIs treated with antibiotic suppressive therapies have a higher incidence and severity of potentially serious future infections, with special attention to acute pyelonephritis, urosepsis, COVID-19, and pneumonia, compared to women who receive antibiotic treatment after they present with a UTI. This is an observational study of data from administrative databases that will not allow causality analysis. The limitations of the study will be handled according to the appropriate statistical methods.

TRIAL REGISTRATION

European Union Electronic Register of Post-Authorisation Studies EUPAS49724; https://www.encepp.eu/encepp/viewResource.htm?id=49725.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/44244.

Improved management of cystitis in primary care following the implementation of a simple multifaceted intervention

Objective

We assessed the impact of the implementation of a simple multifaceted intervention aimed at improving management of cystitis in primary care.

Design

Quality control before and after study.

Site

Primary care centres in Barcelona city provided by the Catalonian Institute of Health.

Participants

The multifaceted intervention consisted of (1) creation of a group with a leader in each of the primary care centres, out of hours services, sexual and reproductive centres, and home visit service, (2) session on management of cystitis in each centre, (3) result feedback for professionals, and (4) provision of infographics for professionals and patients with urinary tract infections. Interventions started in November 2020 and ended in the summer of 2021.

Main measurements

Variation in the prescription of first-line antibiotics, usage of antibiotics, and request for urine cultures before and after this intervention.

Results

Training sessions took place in 93% of the centres. The use of first-line therapies cystitis increased by 6.4% after the intervention (95% confidence interval [CI], 5.7–7.1%). The use of nitrofurantoin in recurrent cystitis increased, mainly in out of hours service (8.7%; 95% CI, 5.2–12.2%). Urine cultures were more frequently requested after the intervention for recurrent cystitis in both primary care centres and out of hours services, with a 7.2% increase [95% CI, 5.9–8.5%), but also for uncomplicated urinary tract infections (3.1%; 95% CI, 1.8–4.4%).

Conclusions

A low-intensity multifaceted intervention on management of cystitis, with strong institutional support, resulted in a better choice of antibiotic in antibiotic prescribing, but the intervention had less impact on the adequacy of urine cultures.

Clinical effectiveness and bacteriological eradication of three different Short-COurse antibiotic regimens and single-dose fosfomycin for uncomplicated lower Urinary Tract infections in adult women (SCOUT study): study protocol for a randomised clinical trial

INTRODUCTION

Uncomplicated lower urinary tract infections (uLUTI) are a common problem in primary care. Current local guidelines recommend the use of a single 3 g dose of fosfomycin. However, most general practitioners (GP) prefer short-course therapies to single-dose therapy. No study has compared head-to-head short-course antimicrobial agents for uLUTIs. Therefore, the aim of this randomised clinical trial is to compare three different short-course antibiotic therapies with a single-dose of fosfomycin for these infections.

METHODS AND ANALYSIS

This will be a pragmatic, multicentre, parallel group, open trial. Women aged 18 or older and with symptoms of uLUTI and a positive urine dipstick analysis will be randomised to one of the following four groups: a single dose of 3 g of fosfomycin, 2 days of 3 g of fosfomycin o.d., 3 days of pivmecillinam 400 mg three times per day (t.i.d) or 5 days of nitrofurantoin 100 mg t.i.d. A total sample of 1120 patients was calculated. The primary endpoint is clinical effectiveness at day 7, defined as cure of symptoms reported by the patients in a diary including four symptoms: dysuria, urgency, frequency and suprapubic pain, which will be scored on a 4-point severity scale (not present/mild/moderate/severe). Follow-up visits are scheduled at days 7 (phone call), 14 and 28 for assessing evolution. Urine samples will be collected in the three on-site visits and urine cultures performed. If positive, antibiograms for the three antibiotics studied will be performed. Bacterial eradication will be measured at days 14 and 28.

ETHICS AND DISSEMINATION

The study was approved by the Ethical Board of IDIAP Jordi Gol (reference number: 21/173-AC) and Spanish Agency of Medicines and Medical Devices. The findings of this trial will be disseminated through research conferences and peer-review journals.

TRIAL REGISTRATION NUMBER

NCT04959331; EudraCT Number: 2021-001332-26.

TIME SCHEDULE

January 2022 to April 2023.

The Synergistic Effect of Mud Crab Antimicrobial Peptides Sphistin and Sph12-38 With Antibiotics Azithromycin and Rifampicin Enhances Bactericidal Activity Against Pseudomonas Aeruginosa

Overuse or abuse of antibiotics has undoubtedly accelerated the increasing prevalence of global antibiotic resistance crisis, and thus, people have been trying to explore approaches to decrease dosage of antibiotics or find new antibacterial agents for many years. Antimicrobial peptides (AMPs) are the ideal candidates that could kill pathogens and multidrug-resistant bacteria either alone or in combination with conventional antibiotics. In the study, the antimicrobial efficacy of mud crab Scylla paramamosain AMPs Sphistin and Sph₁₂₋₃₈ in combination with eight selected antibiotics was evaluated using a clinical pathogen, Pseudomonas aeruginosa. It was interesting to note that the in vitro combination of rifampicin and azithromycin with Sphistin and Sph₁₂₋₃₈ showed significant synergistic activity against P. aeruginosa. Moreover, an in vivo study was carried out using a mouse model challenged with P. aeruginosa, and the result showed that the combination of Sph₁₂₋₃₈ with either rifampicin or azithromycin could significantly promote the healing of wounds and had the healing time shortened to 4–5 days compared with 7–8 days in control. The underlying mechanism might be due to the binding of Sphistin and Sph₁₂₋₃₈ with P. aeruginosa lipopolysaccharides (LPS) and subsequent promotion of the intracellular uptake of rifampicin and azithromycin. Taken together, the significant synergistic antibacterial effect on P. aeruginosa in vitro and in vivo conferred by the combination of low dose of Sphistin and Sph₁₂₋₃₈ with low dose of rifampicin and azithromycin would be beneficial for the control of antibiotic resistance and effective treatment of P. aeruginosa-infected diseases in the future.

Population Bottlenecks Strongly Influence the Evolutionary Trajectory to Fluoroquinolone Resistance in Escherichia coli

Experimental evolution is a powerful tool to study genetic trajectories to antibiotic resistance under selection. A confounding factor is that outcomes may be heavily influenced by the choice of experimental parameters. For practical purposes (minimizing culture volumes), most experimental evolution studies with bacteria use transmission bottleneck sizes of 5 × 106 cfu. We currently have a poor understanding of how the choice of transmission bottleneck size affects the accumulation of deleterious versus high-fitness mutations when resistance requires multiple mutations, and how this relates outcome to clinical resistance. We addressed this using experimental evolution of resistance to ciprofloxacin in Escherichia coli. Populations were passaged with three different transmission bottlenecks, including single cell (to maximize genetic drift) and bottlenecks spanning the reciprocal of the frequency of drug target mutations (108 and 1010). The 1010 bottlenecks selected overwhelmingly mutations in drug target genes, and the resulting genotypes corresponded closely to those found in resistant clinical isolates. In contrast, both the 108 and single-cell bottlenecks selected mutations in three different gene classes: 1) drug targets, 2) efflux pump repressors, and 3) transcription-translation genes, including many mutations with low fitness. Accordingly, bottlenecks smaller than the average nucleotide substitution rate significantly altered the experimental outcome away from genotypes observed in resistant clinical isolates. These data could be applied in designing experimental evolution studies to increase their predictive power and to explore the interplay between different environmental conditions, where transmission bottlenecks might vary, and resulting evolutionary trajectories.

Antimicrobial susceptibility among urinary Escherichia coli isolates from female outpatients: age-related differences

OBJECTIVES

Urinary tract infections (UTIs) are common problems in women, and important reason for visiting primary care physicians, resulting in substantial financial burden to community. The aim of this study was to determine the resistance rates of E. coli to commonly prescribed antimicrobial drugs for community-acquired UTIs in women and to establish the association between age and resistance to antibiotics among isolates of E. coli from urine.

METHODS

The study was designed as a retrospective cross-sectional study during the 5-years period. It was conducted on a sample of urinary tract isolates of E. coli taken from women with community-acquired UTIs. After prevalence of E. coli resistance to antibiotics was established, the analysis of risk factors for emergence of resistance was conducted.

RESULTS

There were 10,734 isolates of E. coli, comprising 70.62% of all samples analyzed. E. coli was the most frequently resistant to ampicillin (54.68%), followed by trimethoprim-sulphamethoxazole (37.46%), first and second generation cephalosporins (cephalexin and cefaclor) (29.53% both), and ciprofloxacin (23.80%). Less than 50% of E. coli isolates was sensitive to all three tested antibiotics, and nearly 13% acquired triple-resistance. Prevalence of isolates resistant to two or three agents was higher in the subgroup of women older than 65 years.

CONCLUSIONS

Empirical choice of antimicrobial agent for community-acquired non-complicated UTIs in women should be individualized on the basis of the patient's age, prevalence of resistance in the local community, and compliance history of the patient.

Phenotypic assays in yeast and zebrafish reveal drugs that rescue ATP13A2 deficiency

Mutations in ATP13A2 (PARK9) are causally linked to the rare neurodegenerative disorders Kufor-Rakeb syndrome, hereditary spastic paraplegia and neuronal ceroid lipofuscinosis. This suggests that ATP13A2, a lysosomal cation-transporting ATPase, plays a crucial role in neuronal cells. The heterogeneity of the clinical spectrum of ATP13A2-associated disorders is not yet well understood and currently, these diseases remain without effective treatment. Interestingly, ATP13A2 is widely conserved among eukaryotes, and the yeast model for ATP13A2 deficiency was the first to indicate a role in heavy metal homeostasis, which was later confirmed in human cells. In this study, we show that the deletion of YPK9 (the yeast orthologue of ATP13A2) in Saccharomyces cerevisiae leads to growth impairment in the presence of Zn2+, Mn2+, Co2+ and Ni2+, with the strongest phenotype being observed in the presence of zinc. Using the ypk9Δ mutant, we developed a high-throughput growth rescue screen based on the Zn2+ sensitivity phenotype. Screening of two libraries of Food and Drug Administration-approved drugs identified 11 compounds that rescued growth. Subsequently, we generated a zebrafish model for ATP13A2 deficiency and found that both partial and complete loss of atp13a2 function led to increased sensitivity to Mn2+. Based on this phenotype, we confirmed two of the drugs found in the yeast screen to also exert a rescue effect in zebrafish-N-acetylcysteine, a potent antioxidant, and furaltadone, a nitrofuran antibiotic. This study further supports that combining the high-throughput screening capacity of yeast with rapid in vivo drug testing in zebrafish can represent an efficient drug repurposing strategy in the context of rare inherited disorders involving conserved genes. This work also deepens the understanding of the role of ATP13A2 in heavy metal detoxification and provides a new in vivo model for investigating ATP13A2 deficiency.

Rapid decline of bacterial drug-resistance in an antibiotic-free environment through phenotypic reversion

Antibiotic resistance typically induces a fitness cost that shapes the fate of antibiotic-resistant bacterial populations. However, the cost of resistance can be mitigated by compensatory mutations elsewhere in the genome, and therefore the loss of resistance may proceed too slowly to be of practical importance. We present our study on the efficacy and phenotypic impact of compensatory evolution in Escherichia coli strains carrying multiple resistance mutations. We have demonstrated that drug-resistance frequently declines within 480 generations during exposure to an antibiotic-free environment. The extent of resistance loss was found to be generally antibiotic-specific, driven by mutations that reduce both resistance level and fitness costs of antibiotic-resistance mutations. We conclude that phenotypic reversion to the antibiotic-sensitive state can be mediated by the acquisition of additional mutations, while maintaining the original resistance mutations. Our study indicates that restricting antimicrobial usage could be a useful policy, but for certain antibiotics only.

Antimicrobial resistance of Escherichia coli isolates from outpatient urinary tract infections in women in six European countries including Russia

OBJECTIVES

In the Northern Dimension Antibiotic Resistance Study (NoDARS), Finland, Germany, Latvia, Poland, Russia and Sweden collected urine samples from outpatient women (aged 18-65years) with symptoms of uncomplicated urinary tract infection (UTI) to investigate the levels of antimicrobial resistance (AMR) among Escherichia coli isolates.

METHODS

A total of 775 E. coli isolates from 1280 clinical urine samples were collected from October 2015 to January 2017. Antimicrobial susceptibility testing was performed and the results were interpreted according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria.

RESULTS

Overall AMR rates to the commonly used antibiotics nitrofurantoin, fosfomycin and mecillinam (except for Germany that was missing a result for mecillinam) were 1.2%, 1.3% and 4.1%, respectively. The highest overall resistance rates were determined for ampicillin (39.6%), trimethoprim (23.8%), trimethoprim/sulfamethoxazole (22.4%), amoxicillin/clavulanic acid (16.7%) and ciprofloxacin (15.1%), varying significantly between countries. The rate of extended-spectrum β-lactamase (ESBL) production was 8.7%. None of the isolates showed resistance to meropenem.

CONCLUSIONS

In most cases, low AMR rates were detected against the first-line antibiotics recommended in national UTI treatment guidelines, giving support to their future use. These results also support the European Association of Urology guidelines stating that nitrofurantoin, fosfomycin and mecillinam are viable treatment options for uncomplicated UTI.

Factors associated with the duration of symptoms in adult women with suspected cystitis in primary care

Objective

The aim of this study was to identify factors associated to the duration of symptoms of cystitis.

Patients and methods

We conducted a nested survival study using Druti study data. Druti was a cross-sectional survey conducted in adult women visiting a general practitioner in France, for a suspected urinary tract infection between January 2012 and February 2013. For this study, urine cultures were systematically performed for all women. The evolution of symptoms were monitored daily for two weeks. This nested study considered only women with suspected cystitis from Druti; women with pyelonephritis were excluded. To identify independent predictors for duration of symptoms, a Cox proportional hazards regression model was performed.

Results

In Druti, 449 patients had a suspected cystitis. Among them, 440 had a follow up at two weeks. Out of the 440 patients, 424 had a prescription of antibiotic treatment (96.4%). The urine culture was positive for 326 patients (74.1%). The median duration of symptoms after consultation was two days (interquartile 1–3). The absence of urinary frequency (median two days versus three days, p = 0.008), age over 55 years (median two days versus three days, p<0.001) and patient’s bet about the presence of a urinary tract infection (median two days, p = 0.021) were associated to a longer duration of symptoms. Positive culture (p = 0.99) and presence of a multi-drug resistant organism (p = 0.38) did not influence the duration of symptoms.

Conclusion

In a real-life study, factors influencing the duration of symptoms are clinical factors. The delay before re-evaluation in case of persistent symptoms after treatment could be adapted according to the initial clinical examination.

Furaltadone suppresses IgE-mediated allergic response through the inhibition of Lyn/Syk pathway in mast cells

Mast cells are critical cells that prompt various allergic response-inducing factors, contributing to allergic diseases. While used as an antibiotic for livestock, there is no study on the effect of furaltadone on allergic response. This study investigated the effect of furaltadone on mast cells and passive cutaneous anaphylaxis (PCA). Furaltadone inhibited the degranulation of mast cells stimulated by antigen (IC₅₀, ~ 3.9 μM), and also suppressed the production of tumor necrosis factor (TNF)-α and interleukin (IL)-4 in a concentration dependent manner. In addition, furaltadone inhibited allergic responses in an acute allergy animal model, PCA. Further investigation on the mechanism for these inhibitory effects of furaltadone found that the activities of Lyn/Syk and Syk-dependent downstream proteins such as mitogen-activated protein (MAP) kinases were inhibited by furaltadone in mast cells. Taken together, this study demonstrates that furaltadone inhibits the activation of mast cells by antigen via the suppression of the Lyn/Syk pathway and ameliorates allergic responses in vivo.

Assessment of the comparability of CLSI, EUCAST and Stokes antimicrobial susceptibility profiles for Escherichia coli uropathogenic isolates

BACKGROUND

As many clinical laboratories convert between Stokes, Clinical and Laboratory Standards Institute (CLSI) and European Committee for Antimicrobial Susceptibility Testing (EUCAST) methods, the problem of comparing differently derived sets of antimicrobial susceptibility testing (AST) data with each other arises, owing to a scarcity of knowledge of inter-method comparability. The purpose of the current study was to determine the comparability of CLSI, EUCAST and Stokes AST methods for determining susceptibility of uropathogenic Escherichia coli to ampicillin, amoxicillin-clavulanate, trimethoprim, cephradine/cephalexin, ciprofloxacin and nitrofurantoin.

METHODS

A total of 100 E. coli isolates were obtained from boric acid urine samples from patients attending GP surgeries. For EUCAST and CLSI, the Kirby-Bauer disc diffusion method was used and results interpreted using the respective breakpoint guidelines. For the Stokes method, direct susceptibility testing was performed on the urine samples.

RESULTS

The lowest levels of agreement were for amoxicillin-clavulanate (60%) and ciprofloxacin (89%) between the three AST methods, when using 2017 interpretive guidelines for CLSI and EUCAST. A comparison of EUCAST and CLSI without Stokes showed 82% agreement for amoxicillin-clavulanate and 94% agreement for ciprofloxacin. Discrepancies were compounded by varying breakpoint susceptibility guidelines issued during the period 2011-2017, and through the inclusion of a definition of intermediate susceptibility in some cases.

CONCLUSIONS

Our data indicate that the discrepancies generated through using different AST methods and different interpretive guidelines may result in confusion and inaccuracy when prescribing treatment for urinary tract infection.

The Activity of Fosfomycin Against Extended-Spectrum Beta-Lactamase-Producing Isolates of Enterobacteriaceae Recovered from Urinary Tract Infections: A Single-Center Study Over a Period of 12 Years

Despite global efforts to tackle resistance in extended-spectrum beta-lactamase (ESBL)-producing isolates via old antibiotics, there are limited data on the efficacy of fosfomycin-an old oral antibiotic-against Enterobacteriaceae in the Middle East. The purpose of this study was to evaluate the in vitro activity of fosfomycin against urinary ESBL-producing isolates of Enterobacteriaceae. Between 2004 and 2015, 363 isolates of ESBL-producing Enterobacteriaceae were recovered from high-risk patients suffering from cardiac disorders and were subjected to polymerase chain reaction using specific primers for the bla_TEM, bla_SHV, and bla_CTX-M genes. Antibiotic susceptibility testing was performed for fosfomycin and other antibiotic comparators. For the isolates considered nonsusceptible to fosfomycin by disk diffusion, the minimum inhibitory concentration (MIC) was determined. The susceptibility rate to fosfomycin remained almost steady (90-100%) over a 12-year period, although it fluctuated vis-à-vis ciprofloxacin (0-54%), trimethoprim/sulfamethoxazole (9.1-31.7%), and nitrofurantoin (41.7-100%). Of all the antibiotics tested, fosfomycin was the most active antimicrobial agent (97%) against the ESBL-positive isolates. Fosfomycin maintained higher activity against ESBL-Escherichia coli than against ESBL-Klebsiella pneumoniae. Only 11 (3%) isolates were not susceptible to fosfomycin according to disk diffusion and they had MICs greater than 1,024 mg/ml. All of the fosfomycin-nonsusceptible isolates were positive for the bla_CTX-M gene (100%), while 5 (45.4%) and 3 (27.3%) of the isolates harbored the bla_TEM and bla_SHV genes, respectively. We showed that fosfomycin had a numerically higher susceptibility rate than the other antibiotics against the ESBL-producing isolates of the most common Enterobacteriaceae. Given its low resistance rate and oral administration, fosfomycin may be deemed a promising antibiotic for the treatment of urinary tract infections caused by ESBL-producing Enterobacteriaceae.

Synthesis and retention properties of molecularly imprinted polymers for antibiotics containing a 5-nitrofuran ring

Impedimetric sensor based on molecularly imprinted polymers synthetized for antibiotics containing a 5-nitrofuran ring.

A High-resolution Typing Assay for Uropathogenic Escherichia coli Based on Fimbrial Diversity

Urinary tract infections (UTIs) are one of the most common bacterial infections in humans, causing cystitis, pyelonephritis, and renal failure. Uropathogenic Escherichia coli (UPEC) is the leading cause of UTIs. Accurate and rapid discrimination of UPEC lineages is useful for epidemiological surveillance. Fimbriae are necessary for the adherence of UPEC strains to host uroepithelia, and seem to be abundant and diverse in UPEC strains. By analyzing all the possible fimbrial operons in UPEC strains, we found that closely related strains had similar types of chaperone-usher fimbriae, and the diversity of fimbrial genes was higher than that of multilocus sequence typing (MLST) genes. A typing assay based on the polymorphism of four gene sequences (three fimbrial genes and one housekeeping gene) and the diversity of fimbriae present was developed. By comparison with the MLST, whole-genome sequence (WGS) and fumC/fimH typing methods, this was shown to be accurate and have high resolution, and it was also relatively inexpensive and easy to perform. The assay can supply more discriminatory information for UPEC lineages, and have the potential to be applied in epidemiological surveillance of UPEC isolates.

Managing chronic bladder diseases with the administration of exogenous glycosaminoglycans: an update on the evidence

Although the pathophysiology of acute chronic cystitis and other 'sensory' disorders, i.e. painful bladder syndrome (PBS) or interstitial cystitis (IC), often remains multifactorial, there is a wide consensus that such clinical conditions may arise from a primary defective urothelium lining or from damaged glycosaminoglycans (GAGs). A 'cascade' of events starting from GAG injury, which fails to heal, may lead to chronic bladder epithelial damage and neurogenic inflammation. To restore the GAG layer is becoming the main aim of new therapies for the treatment of chronic cystitis and PBS/IC. Preliminary experiences with GAG replenishment for different pathological conditions involving the lower urinary tract have been reported. There is a range of commercially available intravesical formulations of these components, alone or in combination. Literature evidence shows that exogenous intravesical hyaluronic acid markedly reduces recurrences of urinary tract infections (UTIs). Patients treated with exogenous GAGs have fewer UTI recurrences, a longer time to recurrence and a greater improvement in quality of life. Exogenous intravesical GAGs have been used for the treatment of PBS/IC. Despite the limitations of most of the studies, findings confirmed the role of combination therapy with hyaluronic acid and chondroitin sulfate as a safe and effective option for the treatment of PBS/IC. To prevent and/or treat radiotherapy and chemotherapy induced cystitis, GAG replenishment therapy has been used showing preliminary encouraging results. The safety profile of exogenous GAGs has been reported to be very favourable, without adverse events of particular significance.

Ultraviolet germicidal irradiation susceptibility of methicillin-resistant Staphylococcus aureus compared with methicillin-susceptible S. aureus

Antibiotic misuse and overuse in both the healthcare and agricultural fields have dramatically increased the prevalence of antibiotic resistance in human pathogens. Two strains of methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43330 and a wild-type) and 1 strain of methicillin-susceptible S. aureus (ATCC 25923) were challenged (9 runs in triplicate) in a preliminary study with ultraviolet germicidal irradiation (UVGI) doses ranging from 0.25 to 3.00 mJ/cm(2). The mean percent kill was calculated for each strain when compared with the control plates (no exposure to UVGI). Then, each strain was challenged (22 runs in triplicate) with UVGI doses of 2.00, 2.50, and 3.00 mJ/cm(2). The results suggest a difference between the doses required to disinfect surfaces with each strain. Assuming a standard error rate of α = 0.05, there was a significant difference in variance between the MRSA (ATCC 43330 and wild type) strains and the S. aureus (ATCC 25923) methicillin-susceptible strain.

Recurrent Lower Urinary Tract Infections Have a Detrimental Effect on Patient Quality of Life: a Prospective, Observational Study

INTRODUCTION

This study investigated the effects of recurrent urinary tract infections (rUTI) and the impact of prophylaxis on rUTI and patients' quality of life (QoL).

METHODS

Altogether, 575 patients affected by rUTI were included in a 6-month observational study. QoL was assessed using the Hospital Anxiety and Depression (HAD) and the Leicester scales. Statistical analyses were performed using SAS® Version 8.2 software (SAS Institute Inc., Cary, NC, USA). The significance level was set at 5%. Spearman correlation was used to assess the degree of correlation between infectious episodes and HAD and Leicester scores. For each parameter, the comparison between Day 0 and Day 180 was performed using Wilcoxon signed-rank test for quantitative data.

RESULTS

In total, 61.9% of patients suffering from rUTI exhibited some degree of depression at baseline (Day 0). Alternative oral non-antimicrobial prophylactic treatment for rUTI [Escherichia coli lyophilized bacterial lysate (OM-89)] was administered to 94.4% of patients (1 capsule a day for 90 days), followed by a 3-month treatment-free period. At the end of the study (Day 180), the mean number of UTI decreased by 59.3% (P ≤ 0.0001), the total HAD score decreased by 32.1% (P ≤ 0.0001), and the mean Leicester score decreased by 44.0% (P ≤ 0.0001) from baseline. There was a correlation trend between the reduction in the numbers of UTI at the end of the study compared to the 6 months prior to study entry and the reduction in the anxiety, depression, total HAD scores, activity, feeling, and total Leicester scores registered from Day 0 to Day 180, suggesting a lessening of emotional problems, and social and functional handicaps with decreasing UTI incidence.

CONCLUSIONS

This study showed that rUTI had a negative impact on patients' QoL and that effective alternative prophylaxis significantly improved their QoL.

Coagulase-negative staphylococci

The definition of the heterogeneous group of coagulase-negative staphylococci (CoNS) is still based on diagnostic procedures that fulfill the clinical need to differentiate between Staphylococcus aureus and those staphylococci classified historically as being less or nonpathogenic. Due to patient- and procedure-related changes, CoNS now represent one of the major nosocomial pathogens, with S. epidermidis and S. haemolyticus being the most significant species. They account substantially for foreign body-related infections and infections in preterm newborns. While S. saprophyticus has been associated with acute urethritis, S. lugdunensis has a unique status, in some aspects resembling S. aureus in causing infectious endocarditis. In addition to CoNS found as food-associated saprophytes, many other CoNS species colonize the skin and mucous membranes of humans and animals and are less frequently involved in clinically manifested infections. This blurred gradation in terms of pathogenicity is reflected by species- and strain-specific virulence factors and the development of different host-defending strategies. Clearly, CoNS possess fewer virulence properties than S. aureus, with a respectively different disease spectrum. In this regard, host susceptibility is much more important. Therapeutically, CoNS are challenging due to the large proportion of methicillin-resistant strains and increasing numbers of isolates with less susceptibility to glycopeptides.

Cranberry and recurrent cystitis: more than marketing?

Epidemiologic studies indicate that millions of people suffer from recurrent cystitis, a pathology requiring antibiotic prophylaxis and entailing high social costs. Cranberry is a traditional folk remedy for cystitis and, which, in the form of a variety of products and formulations has over several decades undergone extensive evaluation for the management of urinary tract infections (UTI). The aim of this retrospective study is to summarize and review the most relevant and recent preclinical and clinical studies on cranberries for the treatment of UTIs. The scientific literature selected for this review was identified by searches of Medline via PubMed. A variety of recent experimental evidence has shed light on the mechanism underlying the anti-adhesive properties of proanthrocyanidins, their structure-activity relationships, and pharmacokinetics. Analysis of clinical studies and evaluation of the cranberry efficacy/safety ratio in the prevention of UTIs strongly support the use of cranberry in the prophylaxis of recurrent UTIs in young and middle-aged women. However, evidence of its clinical use among other patients remains controversial.

Crystal structure of the dithiol oxidase DsbA enzyme from proteus mirabilis bound non-covalently to an active site peptide ligand

The disulfide bond forming DsbA enzymes and their DsbB interaction partners are attractive targets for development of antivirulence drugs because both are essential for virulence factor assembly in Gram-negative pathogens. Here we characterize PmDsbA from Proteus mirabilis, a bacterial pathogen increasingly associated with multidrug resistance. PmDsbA exhibits the characteristic properties of a DsbA, including an oxidizing potential, destabilizing disulfide, acidic active site cysteine, and dithiol oxidase catalytic activity. We evaluated a peptide, PWATCDS, derived from the partner protein DsbB and showed by thermal shift and isothermal titration calorimetry that it binds to PmDsbA. The crystal structures of PmDsbA, and the active site variant PmDsbAC30S were determined to high resolution. Analysis of these structures allows categorization of PmDsbA into the DsbA class exemplified by the archetypal Escherichia coli DsbA enzyme. We also present a crystal structure of PmDsbAC30S in complex with the peptide PWATCDS. The structure shows that the peptide binds non-covalently to the active site CXXC motif, the cis-Pro loop, and the hydrophobic groove adjacent to the active site of the enzyme. This high-resolution structural data provides a critical advance for future structure-based design of non-covalent peptidomimetic inhibitors. Such inhibitors would represent an entirely new antibacterial class that work by switching off the DSB virulence assembly machinery.

Urinary Tract Infections: Leading Initiatives in Selecting Empiric Outpatient Treatment (UTILISE)

BACKGROUND

Overuse of fluoroquinolone antibiotics is associated with outbreaks of methicillin-resistant Staphylococcus aureus and of Clostridium difficile-associated diarrhea and increasing resistance in gram-negative organisms. Over the past decade, resistance of Escherichia coli to ciprofloxacin has increased in the Regina Qu'Appelle Health Region. In August 2011, an exploratory audit of the Regina General Hospital (RGH) emergency department showed that 20% of new antibiotic orders were for fluoroquinolones, and 60% of these new fluoroquinolone orders were for ciprofloxacin. It was postulated that ciprofloxacin was predominantly prescribed for outpatients with urinary tract infection.

OBJECTIVE

To develop, implement, and evaluate a best-practice algorithm for the empiric treatment of uncomplicated urinary tract infection in the RGH emergency department, as part of an educational initiative for emergency physicians.

METHODS

A literature review was conducted and local antibiogram data were analyzed to establish a best-practice algorithm for treatment of uncomplicated urinary tract infection in outpatients seen in the emergency department. A chart review was conducted from January to March 2011 to establish a baseline of empiric antibiotic use. An educational strategy targeting emergency physicians described changes in antibiotic resistance patterns in the health region, principles of antimicrobial stewardship, drivers of resistance, and the results of a literature review of best practice for urinary tract infection in outpatients. A post-intervention audit was conducted from January to March 2012 to determine changes in practice.

RESULTS

Comparison of results from the post-intervention audit with baseline data showed that adherence to best practice increased significantly, from 41% (39/96) before the intervention to 66% (50/76) after the intervention (odds ratio [OR] 2.81, 95% confidence interval [CI] 1.51-5.25; p < 0.001). There was also a significant change in overall antibiotic selection (OR 0.25, 95% CI 0.11-0.58; p < 0.001). Further analysis suggested that this significant change was driven by a decrease in use of ciprofloxacin, from 32% (31/96) to 11% (8/76).

CONCLUSION

Creation of a best-practice algorithm and education focused on emergency physicians significantly increased adherence to best practice and optimized antibiotic prescribing for outpatients with uncomplicated urinary tract infection by limiting overuse of fluoroquinolones, primarily ciprofloxacin.

Microsomal oxidative stress induced by NADPH is inhibited by nitrofurantoin redox biotranformation

Nitrofurantoin is used in the antibacterial therapy of the urinary tract. This therapy is associated with various adverse effects whose mechanisms remain unclear. Diverse studies show that the nitro reductive metabolism of nitrofurantoin leads to ROS generation. This reaction can be catalyzed by several reductases, including the cytochrome P450 (CYP450) reductase. Oxidative stress arising from this nitro reductive metabolism has been proposed as the mechanism underlying the adverse effects associated with nitrofurantoin. There is, however, an apparent paradox between these findings and the ability of nitrofurantoin to inhibit lipid peroxidation provoked by NADPH in rat liver microsomes. This work was aimed to show the potential contribution of different enzymatic systems to the metabolism of this drug in rat liver microsomes. Our results show that microsomal lipid peroxidation promoted by NADPH is inhibited by nitrofurantoin in a concentration-dependent manner. This suggests that the consumption of NADPH in microsomes can be competitively promoted by lipid peroxidation and nitrofurantoin metabolism. The incubation of microsomes with NADPH and nitrofurantoin generated 1-aminohidantoin. In addition, the biotransformation of a classical substrate of CYP450 oxidative system was competitively inhibited by nitrofurantoin. These results suggest that nitrofurantoin is metabolized through CYP450 system. Data are discussed in terms of the in vitro redox metabolism of nitrofurantoin.

A novel 2-(2-methyl-2-nitrovinyl)-furan ectoparasitic drug: physicochemical characterization and determination of the raw material by gas chromatography mass spectrometry

2-(2-methyl-2-nitrovinyl)-furan (NVF) has recently been synthesized and the pharmaceutical industry interest in this compound has grown due to its antibacterial, fungicidal and anti-ectoparasitic activities. Therefore, the physicochemical characterization of new drug was conducted. In addition, two rapid, simple and suitable GC methods were developed for determination of NVF. Analyses were carried out with an Agilent DB-5ms capillary column (60 m × 0.25 mm i.d., 0.25 µm film thickness). The GC-FID analysis employed splitless mode of injection, oven/injector/detector temperature of 160/230/280°C and nitrogen carrier at the flow of 5.0 mL min−1. The GC-MS analysis employed splitless mode of injection, helium carrier at the flow of 1.5 mL min−1, column temperature program with 2 min at 100°C, ramp at 50°C min−1 to 260°C and injector and detector temperature of 250 and 290°tC, respectively. The MS conditions were ionization voltage, 70 eV; mass range, m/z 40–350; and ion source temperature, 200°C. The analysis time took less than 6 min. The results obtained in the validation of the methods suggest that these methods are economic, precise, accurate and linear over the range of analysis. The methods were successfully employed during the synthesis of NVF in order to ensure the quality of the raw material.

Nitrofurantoin Contraindication in Patients with a Creatinine Clearance Below 60 mL/min: Looking for the Evidence

OBJECTIVE

To investigate the evidence leading to nitrofurantoin contraindication in patients with a creatinine clearance (CrCl) below 60 mL/min.

DATA SOURCES

Literature was searched in PubMed (1965-June 2012) by using the key words and MeSH terms urinary tract infections-drug therapy, chronic kidney insufficiency, kidney diseases, pharmacokinetics, safety, and efficacy, combined with nitrofurantoin. Articles were limited to the English language. References from the identified studies, Food and Drug Administration–approved product information packets, drug information resources, and pharmacology books were also reviewed.

DATA SYNTHESIS

The contraindication of nitrofurantoin in patients with a CrCl below 60 mL/min was included in the product information packets sometime between 1988 and 2003. The 1988 Macrodantin product information indicated a CrCl cutoff level of 40 mL/min, but the current contraindication of less than 60 mL/min is found in the 2003 Macrobid product information. It is unclear when and why this change occurred, but it may have followed the work of Sachs and colleagues in 1968, who reported very little drug recovery in the urine of patients with a CrCl below 60 mL/min. This and previous studies have several and severe limitations, such as the inclusion of a small number of patients, an undefined or poorly defined method to determine CrCl and renal impairment, measurement of amounts of nitrofurantoin excreted in the urine instead of urinary concentrations, and most importantly, a lack of clinical efficacy end points. More recently, a chart review on clinical cure of urinary tract infections treated with nitrofurantoin provided grounds for further investigations on the utility of this drug for patients with a CrCl of 60 mL/min or lower. Concerns of increased risks of serious adverse reactions in patients with reduced renal function have further limited the use of nitrofurantoin. However, although not completely clear, these complications seem to be linked most often to prolonged treatment, genetic variability, and predisposition to hypersensitivity.

CONCLUSIONS

Data supporting the contraindication of nitrofurantoin for patients with a CrCl less than 60 mL/min are nonexistent. Well-designed clinical trials with urinary concentration information and clinical end points on patients with various degrees of renal impairment are much needed. Until such a study becomes available, the limited data available would support considering using this drug in patients with a CrCl of 40 mL/min or higher.

Jaundice increases the rate of complications and one-year mortality in patients with hypoxic hepatitis

Hypoxic hepatitis (HH) is the most frequent cause of acute liver injury in critically ill patients. No clinical data exist about new onset of jaundice in patients with HH. This study aimed to evaluate the incidence and clinical effect of jaundice in critically ill patients with HH. Two hundred and six consecutive patients with HH were screened for the development of jaundice during the course of HH. Individuals with preexisting jaundice or liver cirrhosis at the time of admission (n = 31) were excluded from analysis. Jaundice was diagnosed in patients with plasma total bilirubin levels >3 mg/dL. One-year-survival, infections, and cardiopulmonary, gastrointestinal (GI), renal, and hepatic complications were prospectively documented. New onset of jaundice occurred in 63 of 175 patients with HH (36%). In patients who survived the acute event of HH, median duration of jaundice was 6 days (interquartile range, 3-8). Patients who developed jaundice (group 1) needed vasopressor treatment (P < 0.05), renal replacement therapy (P < 0.05), and mechanical ventilation (P < 0.05) more often and had a higher maximal administered dose of norepinephrine (P < 0.05), compared to patients without jaundice (group 2). One-year survival rate was significantly lower in group 1, compared to group 2 (8% versus 25%, respectively; P < 0.05). Occurrence of jaundice was associated with an increased frequency of complications during follow-up (54% in group 1 versus 35% in group 2; P < 0.05). In particular, infections as well as renal and GI complications occurred more frequently in group 1 during follow-up.

CONCLUSION

Jaundice is a common finding during the course of HH. It leads to an increased rate of complications and worse outcome in patients with HH.

Cranberries and lower urinary tract infection prevention

Lower urinary tract infections are very common diseases. Recurrent urinary tract infections remain challenging to treat because the main treatment option is long-term antibiotic prophylaxis; however, this poses a risk for the emergence of bacterial resistance. Some options to avoid this risk are available, including the use of cranberry products. This article reviews the key methods in using cranberries as a preventive measure for lower urinary tract infections, including in vitro studies and clinical trials.

Antibiotic resistance in urinary tract infections in college students

OBJECTIVE

To determine resistance to antibiotics of Escherichia coli in uncomplicated urinary tract infections (uUTIs) in female college students.

PARTICIPANTS

Symptomatic patients presenting to a student health service from September 2008 to December 2009.

METHODS

Clean catch midstream urine samples were tested for urinalysis (UA) and culture and sensitivity.

RESULTS

Of 168 students enrolled in the study, 138 had positive UA, and 94 of these grew >100,000 colonies/mL of E. coli. Ampicillin resistance was 31.9%, trimethoprim-sulfamethoxazole (TMP-SMX) resistance 16.0%, ciprofloxacin resistance 4.3%, amoxicillin/clavulanate resistance 3.2%, and nitrofurantoin resistance 1.1%. The sensitivity of UA was 95.4% and the positive predictive value was 87.0% (p ≤ .001). Specificity was 77.5% and negative predictive value 92.9%.

CONCLUSIONS

In healthy college women with uUTI symptoms, TMP-SMX should not be universally used for empirical therapy, whereas use of ciprofloxacin, amoxicillin/clavulanate, and nitrofurantoin are appropriate.

The adherence of GPs to guidelines for the diagnosis and treatment of lower urinary tract infections in women is poor

OBJECTIVES

To assess the adherence of GPs to evidence-based guidelines for the diagnosis and management of lower urinary tract infection (UTI) in women.

METHODS

A cross-sectional study was performed from March to July 2009 in primary care offices. Physicians consecutively registered the first six UTI attended during an 8-week period. Age, days with symptoms, episode of infection, associated morbidity, signs and symptoms, diagnostic procedures performed, antibiotic prescription, allergies and referral or not were registered. The type of antibiotic course (short or long) and first-choice treatments were also taken into account.

RESULTS

Of 176 physicians invited to participate, 110 (62.5%) included 658 women with lower UTI. Urine dipstick was performed in 550 cases (83.6%) and urine culture was requested in 235 women (35.7%), with criteria for culture in 49.6% and without criteria in 32.8%. Antibiotic treatment was administered in 634 cases (96.4%). Short courses were given to 385 women (60.7%) and 75 of those with complicated UTI were treated with long courses (66.4%). First-choice antibiotics were administered as empiric treatment in only 92 women with uncomplicated UTI (17.7%).

CONCLUSIONS

These results highlight the poor adherence of GPs to the current recommendations of clinical practice guidelines with a high number of inappropriate urine cultures requested and a low utilization of first-choice antibiotics.

L-Proline nutrition and catabolism in Staphylococcus saprophyticus

Staphylococcus saprophyticus strains ATCC 15305, ATCC 35552, and ATCC 49907 were found to require L-proline but not L-arginine for growth in a defined culture medium. All three strains could utilize L-ornithine as a proline source and contained L-ornithine aminotransferase and Δ(1)-pyrroline-5-carboxylate reductase activities; strains ATCC 35552 and ATCC 49907 could use L-arginine as a proline source and had L-arginase activity. The proline requirement also could be met by L-prolinamide, L-proline methyl ester, and the dipeptides L-alanyl-L-proline and L-leucyl-L-proline. The bacteria exhibited L-proline degradative activity as measured by the formation of Δ(1)-pyrroline-5-carboxylate. The specific activity of proline degradation was not affected by addition of L-proline or NaCl but was highest in strain ATCC 49907 after growth in Mueller-Hinton broth. A membrane fraction from this strain had L-proline dehydrogenase activity as detected both by reaction of Δ(1)-pyrroline-5-carboxylate with 2-aminobenzaldehyde (0.79 nmol min(-1) mg(-1)) and by the proline-dependent reduction of p-iodonitrotetrazolium (20.1 nmol min(-1) mg(-1)). A soluble fraction from this strain had Δ(1)-pyrroline-5-carboxylate dehydrogenase activity (88.8 nmol min(-1) mg(-1)) as determined by the NAD(+)-dependent oxidation of DL-Δ(1)-pyrroline-5-carboxylate. Addition of L-proline to several culture media did not increase the growth rate or final yield of bacteria but did stimulate growth during osmotic stress. When grown with L: -ornithine as the proline source, S. saprophyticus was most susceptible to the proline analogues L-azetidine-2-carboylate, 3,4-dehydro-DL-proline, DL-thiazolidine-2-carboxylate, and L-thiazolidine-4-carboxylate. These results indicate that proline uptake and metabolism may be a potential target of antimicrobial therapy for this organism.

Antimicrobial agents for treating uncomplicated urinary tract infection in women

BACKGROUND

Acute uncomplicated lower urinary tract infection (UTI) is one of the most common problems for which young women seek medical attention.

OBJECTIVES

To compare the efficacy, resistance development and safety of different antimicrobial treatments for acute uncomplicated lower UTI.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Renal Group's Specialised Register, MEDLINE, EMBASE and bibliographies of included studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing different classes of antimicrobials for acute uncomplicated UTI in women were included. The outcomes of interest were symptomatic and bacteriological cure at short and long-term follow-up, resistance development, number of days to symptom resolution, days of work loss, adverse events and complications.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data and assessed study quality. Statistical analyses were performed using the random effects model and the results expressed as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Trimethoprim-sulfamethoxazole (TMP-SMX) was as effective as fluoroquinolones in achieving short-term (RR 1.00, 95% CI 0.97 to 1.03) and long-term (RR 0.99, 95% CI 0.94 to 1.05) symptomatic cure. Beta-lactam drugs were as effective as TMP-SMX for short-term (RR 0.95' 95% CI 0.81 to 1.12) and long-term (RR 1.06' 95% CI 0.93 to 1.21) symptomatic cure. Short-term cure for nitrofurantoin was similar to that of TMP-SMX (RR 0.99' 95% CI 0.95 to 1.04) as was long-term symptomatic cure (RR 1.01' 95% CI 0.94 to 1.09).Fluoroquinolones were more effective than beta-lactams (RR 1.22, 95% CI 1.13 to 1.31) for short-term bacteriological cure. Rashes were more frequent in patients treated with TMP-SMX than with nitrofurantoin or fluoroquinolones and in patients treated with beta-lactam drugs compared to fluoroquinolones. Minimal data were available on the emergence of resistant strains during or after antimicrobial treatment.

AUTHORS' CONCLUSIONS

No differences were observed between the classes of antimicrobials included in this review for the symptomatic cure of acute uncomplicated UTI. Fluoroquinolones proved more effective than beta-lactams for the short-term bacteriological outcome, probably with little clinical significance. Individualised treatment should take into consideration the predictable susceptibility of urinary pathogens in local areas, possible adverse events and resistance development, and patient preference.

Host-pathogen interactions in urinary tract infection

The urinary tract is a common site of bacterial infections; nearly half of all women experience at least one urinary tract infection (UTI) during their lifetime. These infections are classified based on the condition of the host. Uncomplicated infections affect otherwise healthy individuals and are most commonly caused by uropathogenic Escherichia coli, whereas complicated infections affect patients with underlying difficulties, such as a urinary tract abnormality or catheterization, and are commonly caused by species such as Proteus mirabilis. Virulence and fitness factors produced by both pathogens include fimbriae, toxins, flagella, iron acquisition systems, and proteins that function in immune evasion. Additional factors that contribute to infection include the formation of intracellular bacterial communities by E. coli and the production of urease by P. mirabilis, which can result in urinary stone formation. Innate immune responses are induced or mediated by pattern recognition receptors, antimicrobial peptides, and neutrophils. The adaptive immune response to UTI is less well understood. Host factors TLR4 and CXCR1 are implicated in disease outcome and susceptibility, respectively. Low levels of TLR4 are associated with asymptomatic bacteriuria while low levels of CXCR1 are associated with increased incidence of acute pyelonephritis. Current research is focused on the identification of additional virulence factors and therapeutic or prophylactic targets that might be used in the generation of vaccines against both uropathogens.

Antibiotic resistance and its cost: is it possible to reverse resistance?

Most antibiotic resistance mechanisms are associated with a fitness cost that is typically observed as a reduced bacterial growth rate. The magnitude of this cost is the main biological parameter that influences the rate of development of resistance, the stability of the resistance and the rate at which the resistance might decrease if antibiotic use were reduced. These findings suggest that the fitness costs of resistance will allow susceptible bacteria to outcompete resistant bacteria if the selective pressure from antibiotics is reduced. Unfortunately, the available data suggest that the rate of reversibility will be slow at the community level. Here, we review the factors that influence the fitness costs of antibiotic resistance, the ways by which bacteria can reduce these costs and the possibility of exploiting them.

Probable nitrofurantoin-induced bronchiolitis obliterans with organizing pneumonia

PURPOSE

A case of bronchiolitis obliterans with organizing pneumonia (BOOP) that developed after three years of nitrofurantoin therapy is described.

SUMMARY

An 89 year-old Caucasian woman weighing 60 kg with diastolic heart failure and a history of urosepsis, viral pericarditis, and atrial fibrillation arrived at the emergency department with worsening dyspnea, shortness of breath that had limited her activities of daily living for three days, and lower extremity edema. Over the previous six months the patient had experienced decreased appetite, abdominal bloating, and a 9.1-kg weight loss. Four months prior, the primary physician diagnosed her symptoms of worsening dyspnea at rest and with exertion as severe bronchitis. Imaging at the time of presentation revealed interstitial fibrosis consistent with nitrofurantoin-induced BOOP. A diagnosis of BOOP was made, nitrofurantoin was discontinued, and the patient was discharged home on oxygen. Prednisone 20 mg was started two weeks later, after no improvement in symptoms was seen. Seven weeks after nitrofurantoin discontinuation, the results of a chest radiograph and computed tomography scan were unchanged, but her symptoms had improved by 20%. The patient was readmitted three weeks later for worsening dyspnea, and it was determined that prednisone had resulted in fluid retention, complicating her diastolic congestive heart failure. Prednisone therapy was therefore tapered off after two months of treatment. No improvement in subjective symptoms, in chest radiograph results, or in BOOP symptoms was seen after three months of prednisone discontinuation and five months of nitrofurantoin discontinuation.

CONCLUSION

An 89-year-old woman developed unresolving BOOP after three years of nitrofurantoin therapy.

Multicentric outcome analysis of sirolimus-based immunosuppression in 252 liver transplant recipients

SUMMARY

The use of sirolimus (SRL) in orthotopic liver transplantation (OLT) has been controversial after experimental data suggested an increased risk of hepatic artery thrombosis (HAT). To assess the safety and efficacy of SRL as de novo immunosuppression in OLT recipients. Outcomes of 252 OLT patients who received SRL were compared with outcomes of 291 OLT recipients who received calcineurin inhibitor in a retrospective study. Primary outcomes of this study were: patient- and graft survivals, vascular, biliary, wound complications and rejection rates. Secondary outcomes were: postoperative infection rate, bone marrow and renal function and changes of lipid levels. Patient- and graft survivals, rejection and infection rates were similar. In the SRL group, HAT occurred in 1.2%, biliary complications in 19.4%, and incisional hernias in 9.1%. In the control group the incidence of HAT was 5.8% (P = 0.004), biliary complications 18.5% (P = NS) and incisional hernias 7.2% (P = NS). Patients on SRL experienced significantly higher levels of serum triglycerides but fewer acute cellular rejections. Bone marrow and renal functions were similar in both the groups. Our findings would suggest that SRL is safe and effective for very selected OLT recipients. Randomized controlled trials are necessary to confirm our results.

Cranberry and urinary tract infections

Urinary tract infection (UTI) refers to the presence of clinical signs and symptoms arising from the genitourinary tract plus the presence of one or more micro-organisms in the urine exceeding a threshold value for significance (ranges from 102 to 103 colony-forming units/mL). Infections are localized to the bladder (cystitis), renal parenchyma (pyelonephritis) or prostate (acute or chronic bacterial prostatitis). Single UTI episodes are very common, especially in adult women where there is a 50-fold predominance compared with adult men. In addition, recurrent UTIs are also common, occurring in up to one-third of women after first-episode UTIs. Recurrences requiring intervention are usually defined as two or more episodes over 6 months or three or more episodes over 1 year (this definition applies only to young women with acute uncomplicated UTIs). A cornerstone of prevention of UTI recurrence has been the use of low-dose once-daily or post-coital antimicrobials; however, much interest has surrounded non-antimicrobial-based approaches undergoing investigation such as use of probiotics, vaccines, oligosaccharide inhibitors of bacterial adherence and colonization, and bacterial interference with immunoreactive extracts of Escherichia coli. Local (intravaginal) estrogen therapy has had mixed results to date. Cranberry products in a variety of formulations have also undergone extensive evaluation over several decades in the management of UTIs. At present, there is no evidence that cranberry can be used to treat UTIs. Hence, the focus has been on its use as a preventative strategy. Cranberry has been effective in vitro and in vivo in animals for the prevention of UTI. Cranberry appears to work by inhibiting the adhesion of type I and P-fimbriated uropathogens (e.g. uropathogenic E. coli) to the uroepithelium, thus impairing colonization and subsequent infection. The isolation of the component(s) of cranberry with this activity has been a daunting task, considering the hundreds of compounds found in the fruit and its juice derivatives. Reasonable evidence suggests that the anthocyanidin/proanthocyanidin moieties are potent antiadhesion compounds. However, problems still exist with standardization of cranberry products, which makes it extremely difficult to compare products or extrapolate results. Unfortunately, most clinical trials have had design deficiencies and none have evaluated specific key cranberry-derived compounds considered likely to be active moieties (e.g. proanthocyanidins). In general, the preventive efficacy of cranberry has been variable and modest at best. Meta-analyses have established that recurrence rates over 1 year are reduced approximately 35% in young to middle-aged women. The efficacy of cranberry in other groups (i.e. elderly, paediatric patients, those with neurogenic bladder, those with chronic indwelling urinary catheters) is questionable. Withdrawal rates have been quite high (up to 55%), suggesting that these products may not be acceptable over long periods. Adverse events include gastrointestinal intolerance, weight gain (due to the excessive calorie load) and drug-cranberry interactions (due to the inhibitory effect of flavonoids on cytochrome P450-mediated drug metabolism). The findings of the Cochrane Collaboration support the potential use of cranberry products in the prophylaxis of recurrent UTIs in young and middle-aged women. However, in light of the heterogeneity of clinical study designs and the lack of consensus regarding the dosage regimen and formulation to use, cranberry products cannot be recommended for the prophylaxis of recurrent UTIs at this time.