Trimethoprim and ciprofloxacin resistance and prescribing in urinary tract infection associated with Escherichia coli: a multilevel model

Bayesian Calibration to Address the Challenge of Antimicrobial Resistance: A Review

Antimicrobial resistance (AMR) emerges when disease-causing microorganisms develop the ability to withstand the effects of antimicrobial therapy. This phenomenon is often fueled by the human-to-human transmission of pathogens and the overuse of antibiotics. Over the past 50 years, increased computational power has facilitated the application of Bayesian inference algorithms. In this comprehensive review, the basic theory of Markov Chain Monte Carlo (MCMC) and Sequential Monte Carlo (SMC) methods are explained. These inference algorithms are instrumental in calibrating complex statistical models to the vast amounts of AMR-related data. Popular statistical models include hierarchical and mixture models as well as discrete and stochastic epidemiological compartmental and agent based models. Studies encompassed multi-drug resistance, economic implications of vaccines, and modeling AMR in vitro as well as within specific populations. We describe how combining these topics in a coherent framework can result in an effective antimicrobial stewardship. We also outline recent advancements in the methodology of Bayesian inference algorithms and provide insights into their prospective applicability for modeling AMR in the future.

Trimethoprim resistance in surface and wastewater is mediated by contrasting variants of the dfrB gene

Trimethoprim (TMP) is a low-cost, widely prescribed antibiotic. Its effectiveness is increasingly challenged by the spread of genes coding for TMP-resistant dihydrofolate reductases: dfrA, and the lesser-known, evolutionarily unrelated dfrB. Despite recent reports of novel variants conferring high level TMP resistance (dfrB10 to dfrB21), the prevalence of dfrB is still unknown due to underreporting, heterogeneity of the analyzed genetic material in terms of isolation sources, and limited bioinformatic processing. In this study, we explored a coherent set of shotgun metagenomic sequences to quantitatively estimate the abundance of dfrB gene variants in aquatic environments. Specifically, we scanned sequences originating from influents and effluents of municipal sewage treatment plants as well as river-borne microbiomes. Our analyses reveal an increased prevalence of dfrB1, dfrB2, dfrB3, dfrB4, dfrB5, and dfrB7 in wastewater microbiomes as compared to freshwater. These gene variants were frequently found in genomic neighborship with other resistance genes, transposable elements, and integrons, indicating their mobility. By contrast, the relative abundances of the more recently discovered variants dfrB9, dfrB10, and dfrB13 were significantly higher in freshwater than in wastewater microbiomes. Moreover, their direct neighborship with other resistance genes or markers of mobile genetic elements was significantly less likely. Our findings suggest that natural freshwater communities form a major reservoir of the recently discovered dfrB gene variants. Their proliferation and mobilization in response to the exposure of freshwater communities to selective TMP concentrations may promote the prevalence of high-level TMP resistance and thus limit the future effectiveness of antimicrobial therapies.

E. coli bacteraemia and antimicrobial resistance following antimicrobial prescribing for urinary tract infection in the community

Background

Urinary tract infections are one of the most common infections in primary and secondary care, with the majority of antimicrobial therapy initiated empirically before culture results are available. In some cases, however, over 40% of the bacteria that cause UTIs are resistant to some of the antimicrobials used, yet we do not know how the patient outcome is affected in terms of relapse, treatment failure, progression to more serious illness (bacteraemia) requiring hospitalization, and ultimately death. This study analyzed the current patterns of antimicrobial use for UTI in the community in Scotland, and factors for poor outcomes.

Objectives

To explore antimicrobial use for UTI in the community in Scotland, and the relationship with patient characteristics and antimicrobial resistance in E. coli bloodstream infections and subsequent mortality.

Methods

We included all adult patients in Scotland with a positive blood culture with E. coli growth, receiving at least one UTI-related antimicrobial (amoxicillin, amoxicillin/clavulanic acid, ciprofloxacin, trimethoprim, and nitrofurantoin) between 1st January 2009 and 31st December 2012. Univariate and multivariate logistic regression analysis was performed to understand the impact of age, gender, socioeconomic status, previous community antimicrobial exposure (including long-term use), prior treatment failure, and multi-morbidity, on the occurrence of E. coli bacteraemia, trimethoprim and nitrofurantoin resistance, and mortality.

Results

There were 1,093,227 patients aged 16 to 100 years old identified as receiving at least one prescription for the 5 UTI-related antimicrobials during the study period. Antimicrobial use was particularly prevalent in the female elderly population, and 10% study population was on long-term antimicrobials. The greatest predictor for trimethoprim resistance in E. coli bacteraemia was increasing age (OR 7.18, 95% CI 5.70 to 9.04 for the 65 years old and over group), followed by multi-morbidity (OR 5.42, 95% CI 4.82 to 6.09 for Charlson Index 3+). Prior antimicrobial use, along with prior treatment failure, male gender, and higher deprivation were also associated with a greater likelihood of a resistant E. coli bacteraemia. Mortality was significantly associated with both having an E. coli bloodstream infection, and those with resistant growth.

Conclusion

Increasing age, increasing co-morbidity, lower socioeconomic status, and prior community antibiotic exposure were significantly associated with a resistant E. coli bacteraemia, which leads to increased mortality.

Prior Antibiotic Use Increases Risk of Urinary Tract Infections Caused by Resistant Escherichia coli among Elderly in Primary Care: A Case-Control Study

We investigated whether prior use of antibiotics affects the risk of mecillinam/trimethoprim/nitrofurantoin/multi-resistant Escherichia coli urinary tract infection (UTI) among elderly patients in general practice. Data on urine culture came from urine samples performed in general practice and sent to hospitals in the Capital Region of Denmark, and prescription data came from a nationwide prescription database. The study population consisted of patients with UTI episodes (n = 41,027) caused by E. coli that received a concurrent antibiotic prescription against UTI from 2012 to 2017. We used a case-control design. Cases were UTI episodes caused by mecillinam, trimethoprim, nitrofurantoin or multi-resistant E. coli and controls were UTI episodes caused by E. coli not displaying the respective resistance pattern. We analyzed whether exposure to antibiotics in a period of 8-90 days prior to the UTI episode affected the risk of antibiotic resistant uropathogenic E coli. The analyses were adjusted for age, sex, hospital admission and nursing home status. The odds of resistance to all of the four antibiotics increased significantly after exposure to antibiotics within 90 days prior to the UTI episode. In general, mecillinam showed the lowest increase in the odds for selection of resistance. The results indicate that mecillinam is a favorable antibiotic choice in terms of selection of resistance.

Presentation, Treatment, and Natural Course of Severe Symptoms of Urinary Tract Infections Measured by a Smartphone App: Observational and Feasibility Study

Background

Urinary tract infections (UTIs) are one of the most common conditions in women. Current information on the presentation, management, and natural course of the infection is based on paper diaries filled out and subsequently posted by patients.

Objective

The aim of this study is to explore the feasibility of a smartphone app to assess the natural course and management of UTIs.

Methods

A smartphone app was developed to collect data from study participants presenting with symptoms of UTI in general practice. After initial demographic and treatment information, symptom severity was recorded by the patient after a reminder on their smartphone, which occurred twice daily for a period of 7 days or until symptom resolution.

Results

A total of 181 women aged 18-76 years downloaded the smartphone app. The duration of symptoms was determined from the results of 178 participants. All patients submitted a urine sample, most patients were prescribed an antibiotic (163/181, 90.1%), and 38.7% (70/181) of the patients had a positive culture. Moderately bad or worse symptoms lasted a mean of 3.8 (SD 3.2; median 4) days, and 70.2% (125/178) of the patients indicated that they were cured on day 4 after consultation. This compares with other research assessing symptom duration and management of UTIs using paper diaries. Patients were very positive about the usability of the smartphone app and often found the reminders supportive. On the basis of the feedback and the analysis of the data, some suggestions for improvement were made.

Conclusions

Smartphone diaries for symptom scores over the course of infections are an efficient and acceptable means of collecting data in research.

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

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

Trends, seasonality and the association between outpatient antibiotic use and antimicrobial resistance among urinary bacteria in the Netherlands

OBJECTIVES

To determine trends, seasonality and the association between community antibiotic use and antimicrobial resistance (AMR) in Escherichia coli and Klebsiella pneumoniae in urinary tract infections.

METHODS

We analysed Dutch national databases from January 2008 to December 2016 regarding antibiotic use and AMR for nitrofurantoin, trimethoprim, fosfomycin and ciprofloxacin. Antibiotic use was expressed as DDD/1000 inhabitant-days (DID) and AMR was expressed as the percentage of resistance from total tested isolates. Temporal trends and seasonality were analysed with autoregressive integrated moving average (ARIMA) models. Each antibiotic use-resistance combination was cross-correlated with a linear regression of the ARIMA residuals.

RESULTS

The trends of DID increased for ciprofloxacin, fosfomycin and nitrofurantoin, but decreased for trimethoprim. Similar trends were found in E. coli and K. pneumoniae resistance to the same antibiotics, except for K. pneumoniae resistance to ciprofloxacin, which decreased. Resistance levels peaked in winter/spring, whereas antibiotic use peaked in summer/autumn. In univariate analysis, the strongest and most significant cross-correlations were approximately 0.20, and had a time delay of 3-6 months between changes in antibiotic use and changes in resistance. In multivariate analysis, significant effects of nitrofurantoin use and ciprofloxacin use on resistance to these antibiotics were found in E. coli and K. pneumoniae, respectively. There was a significant association of nitrofurantoin use with trimethoprim resistance in K. pneumoniae after adjusting for trimethoprim use.

CONCLUSIONS

We found a relatively low use of antibiotics and resistance levels over a 9 year period. Although the correlations were weak, variations in antibiotic use for these four antibiotics were associated with subsequent variations in AMR in urinary pathogens.

[Current state of resistance of E. coli to trimethoprim in uncomplicated urinary tract infections in France]

OBJECTIVE

The objective of this study was to assess the level of resistance of trimethoprim alone (TMP) with respect to E. coli strains isolated from the urines of women with simple acute cystitis in community.

PATIENTS AND METHODS

Prospective study realized for 9 months in 2017-18. A total of 351 urine samples were analyzed. Culture has been made according to the usual techniques and antibiogram was carried out according to the recommendations of the CA-SFM.

RESULTS

The rate of resistance to TMP was 16.5% (58/351). Only 11 strains of E. coli (3%) producing ESBL were found, 5 of which were sensitive to TMP.

CONCLUSION

The resistance rate of E. coli to TMP remains below 20%, the threshold for choosing a probabilistic treatment of a non-serious infection. Considering the good tolerance of TMP and its weak effect on the microbiota during a short treatment, one can propose TMP alone in the probabilistic treatment of simple acute cystitis.

Antimicrobial prescribing and infections in long-term care facilities (LTCF): a multilevel analysis of the HALT 2016 study, Ireland, 2017

Background

The 2016 point prevalence survey (PPS) of healthcare-associated infections (HAI) and antimicrobial use (AMU) in Irish long-term care facilities (LTCF) (HALT) showed a 9.8% AMU and 4.4% HAI prevalence, based on aggregated data analysis.

Aim

Our aim was to identify institutional and resident risk factors of AMU and HAI.

Methods

HALT 2016 gathered information using institutional and resident questionnaires, for residents who met the surveillance definition of active HAI and/or AMU, limiting analysis to the aggregated institutional level. In January 2017, we requested additional data on age, sex, urinary catheter use and disorientation of current residents from HALT 2016 LTCF and matched to 2016 HALT data.

Results

Of 224 HALT 2016 LTCF, 80 provided additional information on 3,816 residents; prevalence of AMU was 10.6% and HAI was 4.7%. Presence of a coordinating physician (Odds ratio (OR): 0.3; 95% confidence interval (CI): 0.2–0.6), antimicrobial stewardship committee (OR: 0.2; 95%; CI: 0.1–0.6), healthcare assistants (OR: 0.9; 95% CI: 0.9–1.0), antimicrobial consumption feedback (OR: 0.3; 95% CI: 0.1–0.6) and medical care by personal general practitioner (OR: 0.6; 95% CI: 0.7–1.0) were associated with less AMU and feedback on surveillance of infection prevention and control (IPC) practices (OR: 0.6; 95% CI: 0.3–1.0) with less HAI. AMU and HAI varied significantly between LTCF.

Conclusions

Multilevel modelling identified significant inter-facility variation, as well as institutional factors associated with AMU and HAI. An antimicrobial stewardship committee linked with feedback on IPC and prescribing was associated with reduced AMU and HAI.

Use of other antimicrobial drugs is associated with trimethoprim resistance in patients with urinary tract infections caused by E. coli

In recent years, high frequencies of trimethoprim resistance in urinary tract infections (UTIs) caused by E. coli are have been reported. Co-resistance to other antimicrobial drugs may play a role in this increase. Therefore, we investigated whether previous use of other antimicrobial drugs was associated with trimethoprim resistance. We conducted a nested case-control study with urinary cultures with E. coli from participants of the Rotterdam Study sent in by general practitioners to the regional laboratory between 1 January 2000 and 1 April 2016. Multivariable logistic regression analysis was performed to study the association between prior prescriptions of several antimicrobial drug groups and trimethoprim resistance using individual participant data. Urinary cultures of 1264 individuals with a UTI caused by E. coli were included. When adjusted for previous other antimicrobial drug use, a history of > 3 prescriptions of extended-spectrum penicillins (OR 1.68; 95% CI 1.10-2.55) was significantly associated with trimethoprim resistance of E. coli as was the use of > 3 prescriptions of sulfonamides and trimethoprim (OR 2.22; 95% CI 1.51-3.26). The use of > 3 prescriptions of nitrofuran derivatives was associated with a lower frequency of trimethoprim resistance (OR 0.60; 95% CI 0.39-0.92), after adjustment for other antimicrobial drug prescriptions. We found that previous use of extended-spectrum penicillins is associated with trimethoprim resistance. On the contrary, previous nitrofurantoin use was associated with a lower frequency of trimethoprim resistance. Especially in individuals with recurrent UTI, co-resistance should be taken into account and susceptibility testing before starting trimethoprim should be considered.

Effect of general practice characteristics and antibiotic prescribing on Escherichia coli antibiotic non-susceptibility in the West Midlands region of England: a 4 year ecological study

Objectives

To assess the effect of general practice characteristics and antibiotic prescribing on the number of non-susceptible Escherichia coli isolated from urine specimens submitted from community settings, we undertook an ecological study of the general practice population in the West Midlands.

Methods

Descriptive analysis and multilevel modelling of temporal trends in antibiotic prescribing and non-susceptibility of E. coli urine isolates to a range of antibiotics prescribed in the community over a 4 year period.

Results

Nine of the 16 antibiotic prescribing/non-susceptibility combinations demonstrated a significant statistical linear correlation with non-susceptibility either for prescribing in a quarter or for prescribing within the previous 12 months. The magnitude of the effect varied, from a 0.3% increase in the odds of non-susceptibility to ampicillin/amoxicillin (when prescribing ampicillin/amoxicillin) to a 6.3% increase in the odds of non-susceptibility to nitrofurantoin (when prescribing nitrofurantoin) for an increase of 50 DDDs per 1000 practice population within a quarter (equivalent to ∼10 courses of antibiotics). In all 16 models, single-handed general practices were shown to have a significant association with increased numbers of non-susceptible E. coli urine isolates (adjusted ORs 1.083-1.657). Increased prescribing of ampicillin/amoxicillin in winter periods was associated with increased non-susceptibility of E. coli isolated from urine specimens.

Conclusions

Small increases in antibiotic prescribing in individual general practices reduce the number of susceptible bacteria in the practice population. To maintain the effectiveness of available treatment, antibiotic stewardship should be encouraged and supported within each practice.

Association between urinary community-acquired fluoroquinolone-resistant Escherichia coli and neighbourhood antibiotic consumption: a population-based case-control study

BACKGROUND

It is unknown whether increased use of antibiotics in a community increases the risk of acquiring antibiotic resistance by individuals living in that community, regardless of prior individual antibiotic consumption and other risk factors for antibiotic resistance.

METHODS

We used a hierarchical multivariate logistic regression approach to evaluate the association between neighbourhood fluoroquinolone consumption and individual risk of colonisation or infection of the urinary tract with fluoroquinolone-resistant Escherichia coli. We did a population-based case-control study of adults (aged ≥22 years) living in 1733 predefined geographical statistical areas (neighbourhoods) in Israel. A multilevel study design was used to analyse data derived from electronic medical records of patients enrolled in the Clalit state-mandated health service.

FINDINGS

300 105 events with E coli growth and 1 899 168 cultures with no growth were identified from medical records and included in the analysis. 45 427 (16·8%) of 270 190 women and 8835 (29·5%) of 29 915 men had fluoroquinolone-resistant E coli events. We found an independent association between residence in a neighbourhood with higher antibiotic consumption and an increased risk of bacteriuria caused by fluoroquinolone-resistant E coli. Odds ratios (ORs) for the quintiles with higher neighbourhood consumption (compared with the lowest quintile) were 1·15 (95% CI 1·06-1·24), 1·31 (1·20-1·43), 1·41 (1·29-1·54), and 1·51 (1·38-1·65) for women, and 1·17 (1·02-1·35), 1·24 (1·06-1·45), 1·35 (1·15-1·59), and 1·50 (1·26-1·77) for men. Results remained significant when the analysis was restricted to patients who had not consumed fluoroquinolones themselves.

INTERPRETATION

These data suggest that increased use of antibiotics in specific geographical areas is associated with an increased personal risk of acquiring antibiotic-resistant bacteria, independent of personal history of antibiotic consumption and other known risk factors for antimicrobial resistance.

FUNDING

None.

Uncomplicated urinary tract infections in Swedish primary care; etiology, resistance and treatment

Background

Uncomplicated urinary tract infection (uUTI) is common and a majority of patients are prescribed antibiotics. There is little knowledge about antibiotic resistance in urine samples from patients with uUTI in primary health care (PHC).

The aim was to describe antibiotic treatment, bacterial findings, the prevalence of resistant E.coli and factors associated with antibiotic resistance. The aim was also to compare the prevalence of resistant E.coli in clinical practice with the prevalence of resistant E.coli in routine microbiological laboratory data.

Methods

This observational study in PHC setting started in November 2014 and ended in March 2016. Women aged 17 years and older with symptoms indicating uUTI from eight PHCs were included. Questionnaires were used to retrieve anamnestic data. All urine samples were sent to the local laboratory of microbiology for diagnostic analysis and susceptibility testing. Proportions of resistant E.coli were compared with corresponding data from the regional laboratory.

Results

Urine cultures were analysed in 304 women with a median age of 46 (IQR 32–66) years. Bacterial growth was found in 243 (80%) of urine samples, and E.coli in 72% of the positive samples. A total of 80% of detected E.coli isolates were susceptible to all tested antimicrobials and resistance rates to ciprofloxacin were lower than reported from the local clinical laboratory. Antibiotic treatment within the last year was independently associated with antibiotic resistant E.coli in the urine sample adjusted OR 4.97 (95% CI 2.04–12.06). A total of 74% of the women were treated with antibiotics. The most prescribed was pivmecillinam followed by nitrofurantoin.

Conclusions

Antibiotic resistance in E.coli was low. Antibiotic treatment within the last year was associated with antibiotic resistant E.coli. Data from the clinical microbiology laboratory indicates that laboratory data may overestimate antibiotic resistance and lead to an unnecessary change in empiric antibiotic treatment of uUTI in primary care. The empirically prescribed antibiotics, were inline with Swedish treatment recommendations for uUTI.

Nanodiamonds facilitate killing of intracellular uropathogenic E. coli in an in vitro model of urinary tract infection pathogenesis

About 25-44% of women will experience at least one episode of recurrent UTI and the causative agent in over 70% of UTI cases is uropathogenic Escherichia coli (UPEC). UPEC cause recurrent UTI by evading the bladder's innate immune system through internalization into the bladder epithelium where antibiotics cannot reach or be effective. Thus, it is important to develop novel therapeutics to eliminate these intracellular pathogens. Nanodiamonds (NDs) are biocompatible nanomaterials that serve as promising candidates for targeted therapeutic applications. The objective of the current study was to investigate if 6 or 25 nm NDs can kill extracellular and intracellular UPEC in infected bladder cells. We utilized the human bladder epithelial cell line, T24, and an invasive strain of UPEC that causes recurrent UTI. We found that acid-purified 6 nm NDs displayed greater antibacterial properties towards UPEC than 25 nm NDs (11.5% vs 94.2% CFU/mL at 100 μg/mL of 6 and 25 nm, respectively; P<0.001). Furthermore, 6 nm NDs were better than 25 nm NDs in reducing the number of UPEC internalized in T24 bladder cells (46.1% vs 81.1% CFU/mL at 100 μg/mL of 6 and 25 nm, respectively; P<0.01). Our studies demonstrate that 6 nm NDs interacted with T24 bladder cells in a dose-dependent manner and were internalized in 2 hours through an actin-dependent mechanism. Finally, internalization of NDs was required for reducing the number of intracellular UPEC in T24 bladder cells. These findings suggest that 6 nm NDs are promising candidates to treat recurrent UTIs.

Antimicrobial susceptibility of long term care facility and general practice urine samples in patients 65 years and older: an observational study

Background

Antimicrobial resistance in long-term care facilities (LTCFs) poses a risk to elderly residents. The aim of this observational study was to investigate recent patterns of antimicrobial susceptibility in urine samples submitted to the Microbiology Laboratory at Cork University Hospital (CUH) from LTCFs in the greater Cork region. The antimicrobial susceptibilities of LTCF and General Practitioner (GP) urine samples sent to CUH, for patients aged over 65 years of age, were compared.

Methods

A retrospective analysis of the antimicrobial susceptibilities of urine samples submitted to the microbiology laboratory at CUH in quarter one of 2011-2014 was conducted. LTCF and GP urine sample susceptibilities, for patients over 65 years of age, were compared using Chi square statistics.

Results

Overall, the LTCF urine samples were less susceptible than GP urine samples to the antimicrobials recommended in the national urinary tract infection guidelines; trimethoprim, nitrofurantoin, cephalexin, co-amoxiclav, ciprofloxacin and amoxicillin ( P < 0.001). Important trends in antimicrobial susceptibility over the time period were noted. A significant reduction in susceptibility to co-amoxiclav was found between Q1 2011 and Q1 2014 in both settings (GP P = 0.013, LTCF P = 0.005). This study provides important information which will contribute to the revision of antimicrobial prescribing guidelines in the future.

Conclusion

This study highlights the need for continuous surveillance of antimicrobial susceptibility trends in LTCFs. Antimicrobial stewardship strategies are urgently required to address antimicrobial resistance and appropriate antimicrobial prescribing in the LTCF setting.

Use of antimicrobial resistance information and prescribing guidance for management of urinary tract infections: survey of general practitioners in the West Midlands

BACKGROUND

There is a marked variation in both antibiotic prescribing practice and urine sampling rates for diagnostic microbiology across general practices in England. To help understand factors driving this variation, we undertook a survey in 2012/13 to determine sampling protocols and antibiotic formularies used by general practitioners (GPs) for managing urinary tract infections (UTIs) in the West Midlands region of England.

METHOD

Cross-sectional survey of all eligible general practices in the West Midlands region of England undertaken in November 2012. GPs were invited to complete an online survey questionnaire to gather information on policies used within the practice for urine sampling for microbiological examination, and the source of antibiotic formularies used to guide treatment of UTIs. The questionnaire also gathered information on how they would manage five hypothetical clinical scenarios encountered in the community.

RESULTS

The response rate was 11.3 % (409/3635 GPs), equivalent to a practice response rate of 26 % (248/950). Only 50 % of GPs reported having a practice policy for urine sampling. Although there was good agreement from GPs regarding collecting specimens in scenarios symbolising treatment failure (98 %), UTI in an adult male (98 %) and asymptomatic UTI in pregnancy (97 %), there was variation in GPs requesting a specimen for the scenarios involving a suspected uncomplicated urinary tract infection (UTI) and an asymptomatic catheterised elderly patient; with 40 and 38 % respectively indicating they would collect a specimen for microbiological examination.

CONCLUSION

Standardised evidence based clinical management policies and antibiotic formularies for GPs should be readily available. This will promote the rational use of diagnostic microbiology services, improve antimicrobial stewardship and aid the interpretation of ongoing antimicrobial resistance surveillance.

Using qualitative insights to change practice: exploring the culture of antibiotic prescribing and consumption for urinary tract infections

OBJECTIVES

The aim of this paper is to explore the culture of antibiotic prescribing and consumption in the community for urinary tract infections (UTI) from the perspective of the general practitioners (GPs) and community member.

DESIGN

Indepth interviews were conducted with GPs, and focus groups were held with community members.

SETTING

General practice and community setting.

PARTICIPANTS

15 GPs practising in rural and urban locations in Ireland participated in the indepth interviews. 6 focus groups (n=42) with participants who had direct or indirect experiences with UTI were also undertaken.

RESULTS

The decision to prescribe or consume an antibiotic for a UTI is a set of complex processes including need recognition, information search and evaluation processes governed by the relationship and interactions between the GP and the patient. Different GP and patient decision-making profiles emerged emphasising the diversity and variety of general practice in real-life settings. The GP findings showed a requirement for more microbiological information on antibiotic resistance patterns to inform prescribing decisions. Focus group participants wanted a conversation with the GP about their illness and the treatment options available.

CONCLUSIONS

Collectively, this research identified the consultation as a priority intervention environment for stimulating change in relation to antibiotics. This paper demonstrates how qualitative research can identify the interacting processes which are instrumental to the decision to prescribe or consume an antibiotic for a suspected UTI. Qualitative research empowers researchers to investigate the what, how and why of interventions in real-life setting. Qualitative research can play a critical and instrumental role in designing behavioural change strategies with high impact on practice. The results of this research were used to design a complex intervention informed by social marketing.

TRIAL REGISTRATION NUMBER

NCT01913860; Pre-results.

Bacteriology of Urine Specimens Obtained from Men with Symptomatic Benign Prostatic Hyperplasia

Background:

Bacteriuria and urinary tract infections are common sequelae of benign prostatic hyperplasia (BPH). Thus, the knowledge of urine bacteriology in men with symptomatic BPH in our environment may play a complementary role in management.

Objectives:

To determine the incidence of bacteriuria and the antibiotic sensitivity pattern of bacterial isolates in cultured urine samples of men with symptomatic BPH.

Patients and Methods:

This was a 1 year prospective study. All patients who presented with lower urinary tract symptoms due to BPH and who met the inclusion criteria were studied. Urine samples were obtained from the patients for microscopy, culture, and sensitivity following standard protocol.

Results:

Ninety-four patients were studied. The age range was 53–80 years with a mean of 65.5 ± 7.8 years. Bacterial isolates were noted in 42 (44.7%) patients. Six of these had two different species of bacterial organisms isolated. Escherichia coli noted in 20 (47.6%) specimens was the most common organism isolated while the least common, Providencia species, was noted in 1 (2.4%). The bacterial isolates were mostly sensitive to imipenem, meropenem, and nitrofurantoin, but showed greater resistance to cefuroxime, gentamicin, and ofloxacin. There was no significant difference between the means for age (P = 0.80), duration of symptoms (P = 0.09), and prostate size (P = 0.52) in the patients with and those without bacteriuria.

Conclusion:

Bacteriuria is a common finding in patients with symptomatic BPH in our setting. The bacterial isolates showed high level of resistance to oral cephalosporins and fluoroquinolones. There is a need to update guidelines in empiric use of antibiotics in this group of patients.

Intervention to improve the quality of antimicrobial prescribing for urinary tract infection: a cluster randomized trial

BACKGROUND

Overuse of antimicrobial therapy in the community adds to the global spread of antimicrobial resistance, which is jeopardizing the treatment of common infections.

METHODS

We designed a cluster randomized complex intervention to improve antimicrobial prescribing for urinary tract infection in Irish general practice. During a 3-month baseline period, all practices received a workshop to promote consultation coding for urinary tract infections. Practices in intervention arms A and B received a second workshop with information on antimicrobial prescribing guidelines and a practice audit report (baseline data). Practices in intervention arm B received additional evidence on delayed prescribing of antimicrobials for suspected urinary tract infection. A reminder integrated into the patient management software suggested first-line treatment and, for practices in arm B, delayed prescribing. Over the 6-month intervention, practices in arms A and B received monthly audit reports of antimicrobial prescribing.

RESULTS

The proportion of antimicrobial prescribing according to guidelines for urinary tract infection increased in arms A and B relative to control (adjusted overall odds ratio [OR] 2.3, 95% confidence interval [CI] 1.7 to 3.2; arm A adjusted OR 2.7, 95% CI 1.8 to 4.1; arm B adjusted OR 2.0, 95% CI 1.3 to 3.0). An unintended increase in antimicrobial prescribing was observed in the intervention arms relative to control (arm A adjusted OR 2.2, 95% CI 1.2 to 4.0; arm B adjusted OR 1.4, 95% CI 0.9 to 2.1). Improvements in guideline-based prescribing were sustained at 5 months after the intervention.

INTERPRETATION

A complex intervention, including audit reports and reminders, improved the quality of prescribing for urinary tract infection in Irish general practice.

TRIAL REGISTRATION

ClinicalTrials.gov, no. NCT01913860.

A new approach to the analysis of antibiotic resistance data from hospitals

We aimed to develop a new approach to the analysis of antimicrobial resistance data from the hospitals, which allows simultaneous analysis of both individual- and population-level determinants of bacterial resistance. This was a retrospective cohort study that included adult patients who stayed in the hospital >2 days. We analyzed data using shared frailty Cox models and tested our approach using a priori hypotheses based on biology and epidemiology of antibiotic resistance. For gram-negative bacteria, the use of the major selecting antibiotic by an individual was the main risk factor for acquiring resistant species. Hazard ratios (HRs) were strikingly high for ceftazidime-resistant Enterobacter species (HR=11.17; 95% confidence interval [CI]: 5.67-22.02), ciprofloxacin-resistant Pseudomonas aeruginosa (HR=4.41; 95% CI: 2.14-9.08), and imipenem-resistant P. aeruginosa (HR=7.92; 95% CI: 4.35-14.43). Ward-level use was significant for vancomycin-resistant enterococci (VRE) (HR=1.40; 95% CI: 1.07-1.83) and for imipenem-resistant P. aeruginosa (HR=1.40; 95% CI: 1.08-1.83). Previous incidence of infection in the same ward increased the risk of acquiring methicillin-resistant Staphylococcus aureus (HR=1.22; 95% CI: 1.15-1.30) and VRE (HR=1.53; 95% CI: 1.38-1.70). Our results were consistent with our hypotheses and showed that combining population- and individual-level data is crucial for the exploration of antimicrobial resistance development.

Clinical importance and epidemiology of quinolone resistance

The quinolone class of antimicrobial agents is one of most widely used classes of antimicrobial agents in outpatient and inpatient treatment. However, quinolone resistance in gram-positive and gram-negative bacteria has emerged and increased globally. This resistance limits the usefulness of quinolones in clinical practice. The review summarizes mechanisms of quinolone resistance and its epidemiology and implications in the most common clinical settings, urinary tract infections, respiratory tract infections, intraabdominal infections, skin and skin structure infections, and sexually transmitted diseases.

Factors associated with ciprofloxacin- and cefotaxime-resistant Escherichia coli in women with acute pyelonephritis in the emergency department

BACKGROUND

High rates of antimicrobial resistance in Escherichia coli isolated from patients with urinary tract infections have been reported worldwide. The aim of this study was to identify risk factors for resistance to ciprofloxacin (CIP) and cefotaxime (CTX) in E. coli isolated from patients with acute pyelonephritis (APN).

METHODS

We prospectively identified women over 18 y of age who visited the emergency department of one of 10 hospitals with APN and whose urine culture grew E. coli. The study was conducted from April 16 to June 10, 2012.

RESULTS

Of the 229 patients identified, 173 (75.5%) had community-associated (CA) infections and 56 (24.5%) had healthcare-associated (HCA) infections. Sixty-seven isolates (29.3%) were resistant to CIP, 45 (19.7%) to CTX, and 29 (12.7%) to both CIP and CTX. Multivariate analyses revealed that hematologic disease, chronic kidney disease, a bed-ridden state, indwelling urinary catheter, antibiotic treatment in the preceding 3 months, and isolation of CIP-resistant E. coli in the urine within the preceding 3 months, were significantly associated with resistance to both CIP and CTX.

CONCLUSIONS

Chronic conditions and healthcare-associated factors were related to resistance to both fluoroquinolones and third-generation cephalosporins in women with APN. Continued and vigilant surveillance is necessary to monitor the dissemination of antimicrobial resistance in uropathogens.

Antibiotic treatment of acute uncomplicated cystitis based on rapid urine test and local epidemiology: lessons from a primary care series

Background

Acute uncomplicated cystitis (AUC) is an ideal target of optimization for antibiotic therapy in primary care. Because surveillance networks on urinary tract infections (UTI) mix complicated and uncomplicated UTI, reliable epidemiological data on AUC lack. Whether the antibiotic choice should be guided by a rapid urine test (RUT) for leukocytes and nitrites has not been extensively studied in daily practice. The aim of this primary care study was to investigate local epidemiology and RUT-daily use to determine the optimal strategy.

Methods

General practitioners included 18–65 years women with symptoms of AUC, performed a RUT and sent urines for analysis at a central laboratory. Different treatment strategies were simulated based on RUT and resistance results.

Results

Among 347 enrolled patients, 78% had a positive urine culture. Escherichia coli predominated (71%) with high rates of susceptibility to nitrofurantoin (100%), fosfomycin (99%), ofloxacin (97%), and even pivmecillinam (87%) and trimethoprim-sulfamethoxazole (87%). Modelization showed that the systematic use of RUT would reduce by 10% the number of patients treated. Fosfomycin for patients with positive RUT offered a 90% overall bacterial coverage, compared to 98% for nitrofurantoin. 95% for ofloxacin, 86% for trimethoprim-sulfamethoxazole and 78% for pivmecillinam.

Conclusion

Local epidemiology surveillance data not biased by complicated UTI demonstrates that the worldwide increase in antibiotic resistance has not affected AUC yet. Fosfomycin first line in all patients with positive RUT seems the best treatment strategy for AUC, combining good bacterial coverage with expected low toxicity and limited effect on fecal flora.

Trial registration

The current study was registered at clinicaltrials.gov (NCT00958295)

Supporting the improvement and management of prescribing for urinary tract infections (SIMPle): protocol for a cluster randomized trial

BACKGROUND

The overuse of antimicrobials is recognized as the main selective pressure driving the emergence and spread of antimicrobial resistance in human bacterial pathogens. Urinary tract infections (UTIs) are among the most common infections presented in primary care and empirical antimicrobial treatment is currently recommended. Previous research has identified that a substantial proportion of Irish general practitioners (GPs) prescribe antimicrobials for UTIs that are not in accordance with the Guidelines for Antimicrobial Prescribing in Primary Care in Ireland. The aim of this trial is to design, implement and evaluate the effectiveness of a complex intervention on GP antimicrobial prescribing and adult (18 years of age and over) patients' antimicrobial consumption when presenting with a suspected UTI.

METHODS/DESIGN

The Supporting the Improvement and Management of Prescribing for urinary tract infections (SIMPle) study is a three-armed intervention with practice-level randomization. Adult patients presenting with suspected UTIs in primary care will be included in the study.The intervention integrates components for both GPs and patients. For GPs the intervention includes interactive workshops, audit and feedback reports and automated electronic prompts summarizing recommended first-line antimicrobial treatment and, for one intervention arm, a recommendation to consider delayed antimicrobial treatment. For patients, multimedia applications and information leaflets are included. Thirty practices will be recruited to the study; laboratory data indicate that 2,038 patients will be prescribed an antimicrobial in the study. The primary outcome is a change in prescribing of first-line antimicrobials for UTIs in accordance with the Guidelines for Antimicrobial Prescribing in Primary Care in Ireland. The study will take place over 15 months with a six-month intervention period. Data will be collected through a remote electronic anonymized data-extraction system, a text-messaging system and GP and patient interviews and surveys. The intervention will be strengthened by the implementation of a social marketing framework and an economic evaluation.

TRIAL REGISTRATION

This intervention is registered at ClinicalTrials.gov, ID NCT01913860.

Management of urinary tract infections in the era of increasing antimicrobial resistance

Antimicrobial resistance of urinary pathogens is increasing. Most urinary tract infections (UTIs) should still be treated empirically. However, patients with recurrence or other risk factors for resistance may benefit from urine culture. Patients with recurrent UTI often resort to antibiotic prevention, a risky proposition in terms of resistance. Non-antimicrobial preventative methods should be considered first. If preventative antibiotics must be used, postcoital patient-initiated protocols are effective and reduce overall antibiotic exposure compared with continuous prophylaxis. Consider referring patients for urologic evaluation when at risk for complicated UTIs or when recurrence continues despite conservative interventions.

Exploratory Spatial Mapping of the Occurrence of Antimicrobial Resistance in E. coli in the Community

The use of antimicrobials over the past six decades has been associated with the emergence and dissemination of antimicrobial-resistant bacteria. To explore local geographical patterns in the occurrence of acquired antimicrobial resistance (AMR), AMR of E. coli causing urinary tract infections (UTI) in the community in the West of Ireland was mapped. All adult patients consulting with a suspected UTI in 22 general practices in the West of Ireland over a nine-month study period were requested to supply a urine sample. Those with a laboratory confirmed E. coli infection were included (n = 752) in the study. Antimicrobial susceptibility testing was performed by standardized disc diffusion. Patient addresses were geocoded. The diameters of the zone of inhibition of growth for trimethoprim (5 μg) and ciprofloxacin (5 μg) for the relevant isolate was mapped against the patient address using ArcGIS software. A series of maps illustrating spatial distribution of AMR in the West of Ireland were generated. The spatial data demonstrated a higher proportion of isolates with AMR from urban areas. Some rural areas also showed high levels of resistant E. coli. Our study is the first to demonstrate the feasibility of using a geographical information system (GIS) platform for routine visual geographical analysis of AMR data in Ireland. Routine presentation of AMR data in this format may be valuable in understanding AMR trends at a local level.

The antibiotic susceptibility patterns of uropathogenic Escherichia coli, with special reference to the fluoroquinolones

CONTEXT

The emergence of drug resistance to trimethoprim-sulfamethoxazole, the penicillins, cephalosporins, and fluoroquinolones by Uropathogenic Escherichia coli (UPEC) has limited the options for selecting the appropriate antibiotic for the treatment of urinary tract infections.

AIMS

The The E. coli isolates, which were obtained from the culture of urine samples,were studied for their antibiotic resistance patterns, with special reference to the antimicrobial activity of the fluoroquinolones and the production of the extended spectrum β-lactamases. (ESBL), Settings and Design: This was a hospital based, prospective study which was done for a period of eighteen months.

MATERIAL AND METHODS

This study was done by using the standard culture techniques for urine samples, the modified Kirby-Bauer disk diffusion method for the antibiotic susceptibility testing and the disk diffusion method to confirm the ESBL production by the clinical isolates of E. coli in urine. The sensitivity pattern was correlated with the clinical condition and the presence of the risk factors. The statistical analysis which was used: The statistical analysis was done by using the proportions of sensitive, resistant and intermediates. Descriptive statistics like the total, mean and percentage were done by using the Statistical Package for the Social Sciences (SPSS), version 15.0.

RESULTS

The hospital isolates showed high degrees of resistance to the penicillins, cephalosporins, nalidixic acid and the fluoroquinolones, with 59% of the isolates being ESBL producers.

CONCLUSIONS

The incidence of the multidrug resistant strains of Escherichia coli has been steadily increasing over the past few years. The knowledge on the resistance pattern of the bacterial strains in a geographical area will help in guiding the appropriate and the judicious use of antibiotics. Also, the formulation of an appropriate hospital antibiotic policy will go a long way in controlling these infections.

Foodborne urinary tract infections: a new paradigm for antimicrobial-resistant foodborne illness

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide. Disproportionately affecting women, UTIs exact a substantial public burden each year in terms of direct medical expenses, decreased quality of life, and lost productivity. Increasing antimicrobial resistance among strains of extraintestinal pathogenic Escherichia coli challenges successful treatment of UTIs. Community-acquired UTIs were long considered sporadic infections, typically caused by the patients' native gastrointestinal microbiota; however, the recent recognition of UTI outbreaks with probable foodborne origins has shifted our understanding of UTI epidemiology. Along with this paradigm shift come new opportunities to disrupt the infection process and possibly quell increasing resistance, including the elimination of non-therapeutic antimicrobial use in food-animal production.

Is living in a border region a risk for a high prevalence of resistance?

This study assessed the antimicrobial resistance and population structure of Staphylococcus aureus isolated from general practice (GP) patients and nursing home (NH) residents in the province of Limburg (near the border with Germany and Belgium) in comparison with those obtained in the remaining provinces of the Netherlands. A total of 617 and 418 S. aureus isolates were isolated from 2,691 to 1,351 nasal swabs from GP patients and NH residents, respectively. Quantitative antibiotic susceptibility testing was performed using a microbroth dilution method. Putative methicillin-resistant S. aureus (MRSA) isolates were tested for the presence of the mecA gene and spa typing was performed on all S. aureus isolates. No significant differences in the prevalence of resistance were found between the two groups of GP isolates, but the isolates from the NH residents showed a lower resistance for trimethoprim-sulfamethoxazole (p = 0.003) in Limburg province compared with the remaining provinces in the Netherlands. Among the isolates from NH residents in Limburg province, the prevalence of spa-CC 084 was higher (p = 0.003) and that of spa-CC 002 was lower (p = 0.01) compared with isolates from NHs in the remaining provinces of the Netherlands. We observed no differences in resistance and population structure between S. aureus isolates from GP patients in Limburg and the remaining provinces of the Netherlands, and only a few differences were observed between the NH populations. There was no higher prevalence of resistance among the GP and NH isolates from Limburg compared with the remaining provinces.

Zoonotic potential of multidrug-resistant extraintestinal pathogenic Escherichia coli obtained from healthy poultry carcasses in Salvador, Brazil

The zoonotic potential to cause human and/or animal infections among multidrug-resistant extraintestinal pathogenic Escherichia coli from avian origin was investigated. Twenty-seven extraintestinal pathogenic E. coli isolates containing the increased survival gene (iss) were obtained from the livers of healthy and diseased poultry carcasses at two slaughterhouses in Salvador, northeastern Brazil. The antimicrobial resistance-susceptibility profiles were conducted with antibiotics of avian and/or human use by the standardized disc-diffusion method. Antimicrobial resistance was higher for levofloxacin (51.8%), amoxicillin/clavulanic acid (70.4%), ampicillin (81.5%), cefalotin (88.8%), tetracycline (100%) and streptomycin (100%). The minimum inhibitory concentrations above the resistance breakpoints of doxycycline, neomycin, oxytetracycline and enrofloxacin reached, respectively, 88.0%, 100%, 75% and 91.7% of the isolates. Strains with high and low antimicrobial resistance were i.p. administered to Swiss mice, and histopathological examination was carried out seven days after infection. Resistance to goat and human serum complement was also evaluated. The results show that Swiss mice challenged with strain 2B (resistant to 11 antimicrobials) provoked a severe degeneration of hepatocytes besides lymphocytic infiltration in the liver, whereas the spleen showed areas of degeneration of the white and red pulp. Conversely, the spleen and liver of mice challenged with strain 4A (resistant to two antimicrobials) were morphologically preserved. In addition, complement resistance to goat and human serum was high for strain 2B and low for strain 4A. Our data show that multidrug resistance and pathogenesis can be correlated in extraintestinal pathogenic E. coli strains obtained from apparently healthy poultry carcasses, increasing the risk for human public healthy.