Risk factors for community-acquired urinary tract infection due to quinolone-resistant E. coli

Regional Variation in Urinary Escherichia coli Resistance Among Outpatients in Washington State, 2013-2019

Escherichia coli (E. coli) is a predominant pathogen of urinary tract infections (UTIs) in the United States. We analyzed resistance patterns by geographic location in Washington State to assess the need for regional antibiograms. The study included urinary E. coli antibiotic susceptibility tests performed by Quest Diagnostics on Washington outpatient isolates from 2013 to 2019. We conducted logistic regressions with robust standard errors for five antibiotics (ceftriaxone, ciprofloxacin, gentamicin, trimethoprim-sulfamethoxazole), with isolates classified as "susceptible" or "resistant" for each antibiotic tested. Analyses were adjusted for sex, year of isolate collection, and age group (0-18, 19-50, >50). The state's nine Public Health Emergency Preparedness Regions (PHEPRs) were used as the geographic level for the analysis. The analysis included 40,217 isolates (93% from females, mean age 47 years). Compared to the Central PHEPR (containing Seattle), most other regions had significantly lower adjusted prevalence ratios (aPORs) of antimicrobial resistance (AMR), with aPORs as low as 0.20 (95% CI: 0.06-0.63) for ceftriaxone in the North Central region. Additionally, no regions had significantly higher aPOR of resistance for any antibiotic. Differences in resistance between the Central and other regions varied by antibiotic with the largest difference for ceftriaxone and smallest for ampicillin. The finding of regional variation of E. coli AMR calls for more specific community antibiograms to enable a precise approach to antibiotic prescribing and stewardship.

Determining a urinary-specific antibiogram and risk factors of trimethoprim/sulfamethoxazole, ciprofloxacin and multidrug resistance among Enterobacterales in primary care

BACKGROUND

Risk factors for ciprofloxacin or MDR in primary care urine specimens are not well defined.

OBJECTIVES

We created a primary care-specific antibiogram for Escherichia coli isolates from cases with complicated and uncomplicated urinary tract infection (UTI) and evaluated risk factors for ciprofloxacin, trimethoprim/sulfamethoxazole and MDR among Enterobacterales.

METHODS

We conducted a cross-sectional study to determine resistance and risk factors by collecting urine cultures from all patients (≥18 years) presenting with provider-suspected UTI at two primary care, safety-net clinics in Houston, TX, USA between November 2018 and March 2020.

RESULTS

Among 1262 cultures, 308 cultures grew 339 uropathogens. Patients with Enterobacterales (n = 199) were mostly female (93.5%) with a mean age of 48.5 years. E. coli was the predominant uropathogen isolated (n = 187/339; 55%) and had elevated trimethoprim/sulfamethoxazole (43.6%) and ciprofloxacin (29.5%) resistance, low nitrofurantoin (1.8%) resistance, and no fosfomycin resistance. Among E. coli, 10.6% were ESBL positive and 24.9% had MDR. Birth outside the U.S.A., prior (2 year) trimethoprim/sulfamethoxazole resistance, and diabetes mellitus were associated with trimethoprim/sulfamethoxazole resistance. Prior (60 day) fluoroquinolone use, prior ciprofloxacin resistance and both diabetes mellitus and hypertension were strongly associated with ciprofloxacin resistance. Prior fluoroquinolone use and a history of resistance to any studied antibiotic were associated with MDR, while pregnancy was protective.

CONCLUSIONS

We found elevated resistance to UTI-relevant antimicrobials and novel factors associated with resistance; these data can be incorporated into clinical decision tools to improve organism and drug concordance.

Propolis as an adjunctive therapy for treatment of uncomplicated cystitis in women: A randomized double-blind placebo-controlled trial

The current research is designed to investigate the effect of propolis supplementation on the clinical manifestations in women suffering from uncomplicated cystitis. In this randomized double-blind, placebo-controlled trial, 120 women with uncomplicated cystitis were selected and randomly assigned into two groups to receive two 500 mg capsules of propolis or placebo daily for 7 days along with ciprofloxacin (250 mg). Clinical symptoms including hematuria, urinary frequency, dysuria, suprapubic pain, and urgency, as well as bacteriuria, were assessed before and after the intervention. After supplementation, participants in the intervention group had significantly fewer days of urinary frequency (p < 0.001), dysuria (p = 0.005), and urgency (p = 0.03). However, there was no significant difference between the two groups regarding hematuria and suprapubic pain (p > 0.05). Furthermore, the severity of bacteriuria decreased significantly in both groups. In conclusion, it seems that propolis supplementation in women with uncomplicated cystitis could improve urinary frequency, dysuria, and urgency. However, further clinical trials should be conducted to fully understand the effects of propolis in women suffering from uncomplicated cystitis.

Clinical Risk Scores to Predict Nonsusceptibility to Trimethoprim-Sulfamethoxazole, Fluoroquinolone, Nitrofurantoin, and Third-Generation Cephalosporin Among Adult Outpatient Episodes of Complicated Urinary Tract Infection

Background

Clinical risk scores were developed to estimate the risk of adult outpatients having a complicated urinary tract infection (cUTI) that was nonsusceptible to trimethoprim-sulfamethoxazole (TMP-SMX), fluoroquinolone, nitrofurantoin, or third-generation cephalosporin (3-GC) based on variables available on clinical presentation.

Methods

A retrospective cohort study (1 December 2017-31 December 2020) was performed among adult members of Kaiser Permanente Southern California with an outpatient cUTI. Separate risk scores were developed for TMP-SMX, fluoroquinolone, nitrofurantoin, and 3-GC. The models were translated into risk scores to quantify the likelihood of nonsusceptibility based on the presence of final model covariates in a given cUTI outpatient.

Results

A total of 30 450 cUTIs (26 326 patients) met the study criteria. Rates of nonsusceptibility to TMP-SMX, fluoroquinolone, nitrofurantoin, and 3-GC were 37%, 20%, 27%, and 24%, respectively. Receipt of prior antibiotics was the most important predictor across all models. The risk of nonsusceptibility in the TMP-SMX model exceeded 20% in the absence of any risk factors, suggesting that empiric use of TMP-SMX may not be advisable. For fluoroquinolone, nitrofurantoin, and 3-GC, clinical risk scores of 10, 7, and 11 predicted a ≥20% estimated probability of nonsusceptibility in the models that included cumulative number of prior antibiotics at model entry. This finding suggests that caution should be used when considering these agents empirically in patients who have several risk factors present in a given model at presentation.

Conclusions

We developed high-performing parsimonious risk scores to facilitate empiric treatment selection for adult outpatients with cUTIs in the critical period between infection presentation and availability of susceptibility results.

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.

Minimizing treatment-induced emergence of antibiotic resistance in bacterial infections

Currently, treatment of bacterial infections focuses on choosing an antibiotic which matches a pathogen’s susceptibility, with less attention to the risk that even susceptibility-matched treatments can fail due to resistance emerging in response to treatment. Here, combining whole-genome sequencing of 1,113 pre- and post- treatment bacterial isolates with machine-learning analysis of 140,349 urinary tract infections (UTIs) and 7,365 wound infections, we find that treatment-induced emergence of resistance could be predicted and minimized at the individual-patient level. Emergence of resistance was common, yet driven not by de novo resistance evolution, but rather by rapid reinfection with a different strain resistant to the prescribed antibiotic. As most infections are seeded from the patient’s own microbiota, these resistance-gaining recurrences can be predicted based on the patient’s past infection history, and their expected risk minimized by machine learning personalized antibiotic recommendations, offering a means to reduce the emergence and spread of resistant pathogens.

From Pathophysiological Hypotheses to Case-Control Study Design: Resistance from Antibiotic Exposure in Community-Onset Infections

Antimicrobial resistance is a global public health concern, at least partly due to the misuse of antibiotics. The increasing prevalence of antibiotic-resistant infections in the community has shifted at-risk populations into the general population. Numerous case-control studies attempt to better understand the link between antibiotic use and antibiotic-resistant community-onset infections. We review the designs of such studies, focusing on community-onset bloodstream and urinary tract infections. We highlight their methodological heterogeneity in the key points related to the antibiotic exposure, the population and design. We show the impact of this heterogeneity on study results, through the example of extended-spectrum β-lactamases producing Enterobacteriaceae. Finally, we emphasize the need for the greater standardization of such studies and discuss how the definition of a pathophysiological hypothesis specific to the bacteria-resistance pair studied is an important prerequisite to clarify the design of future studies.

Type 2 diabetes mellitus and antibiotic-resistant infections: a systematic review and meta-analysis

BACKGROUND

Type 2 diabetes mellitus (T2DM) has been associated with infectious diseases; however, whether T2DM is associated with bacterial-resistant infections has not been thoroughly studied. We ascertained whether people with T2DM were more likely to experience resistant infections in comparison to T2DM-free individuals.

METHODS

Systematic review and random-effects meta-analysis. The search was conducted in Medline, Embase and Global Health. We selected observational studies in which the outcome was resistant infections (any site), and the exposure was T2DM. We studied adult subjects who could have been selected from population-based or hospital-based studies. I² was the metric of heterogeneity. We used the Newcastle-Ottawa risk of bias scale.

RESULTS

The search retrieved 3370 reports, 97 were studied in detail and 61 (449 247 subjects) were selected. Studies were mostly cross-sectional or case-control; several infection sites were studied, but mostly urinary tract and respiratory infections. The random-effects meta-analysis revealed that people with T2DM were twofold more likely to have urinary tract (OR=2.42; 95% CI 1.83 to 3.20; I² 19.1%) or respiratory (OR=2.35; 95% CI 1.49 to 3.69; I² 58.1%) resistant infections. Although evidence for other infection sites was heterogeneous, they consistently suggested that T2DM was associated with resistant infections.

CONCLUSIONS

Compelling evidence suggests that people with T2DM are more likely to experience antibiotic-resistant urinary tract and respiratory infections. The evidence for other infection sites was less conclusive but pointed to the same overall conclusion. These results could guide empirical treatment for patients with T2DM and infections.

Epidemiology of antibiotic treatment for uncomplicated cystitis in adults in Japan

INTRODUCTION

A large number of antibiotics are used for the treatment of uncomplicated cystitis owing to its high morbidity. As the administration of antibiotics for uncomplicated cystitis may be considered an example of inappropriate use, outpatient antimicrobial stewardship for this condition is important. We evaluated the current pharmacoepidemiology trends for the treatment of uncomplicated cystitis in Japan to predict stewardship strategies.

METHODS

This descriptive observational study analyzed data from an anonymized claims database of employees and their family members covered by the employer's health insurance. We identified female outpatients diagnosed with acute cystitis (ICD-10 code N300) aged ≥15 years and extracted oral antibiotic prescription records between 2013 and 2016. We excluded prescriptions for >7 days.

RESULTS

The most prescribed antibiotic category was fluoroquinolones (52.67%), followed by cephalosporins and penems (40.63%). Third-generation cephalosporins accounted for 90.91% of cephalosporin and penem prescriptions. The most common duration of antibiotic prescription was 5 days, except for first-generation cephalosporins, penem (7 days) and sulfamethoxazole and trimethoprim (3 days).

CONCLUSION

Fluoroquinolones and third-generation cephalosporins were prescribed to most uncomplicated cystitis cases in Japan. Although the lack of alternatives to quinolones and beta-lactams in Japan is an obstacle for antimicrobial stewardship for uncomplicated cystitis, promoting accurate diagnoses and establishing alternatives available in the Japanese market are important. Shortening the treatment duration is also an important strategy. Further research is needed on local antimicrobial resistance patterns to determine a fixed treatment strategy for uncomplicated cystitis.

Changes in Clinical Characteristics of Community-Acquired Acute Pyelonephritis and Antimicrobial Resistance of Uropathogenic Escherichia coli in South Korea in the Past Decade

This study examined changes in the clinical characteristics of community-acquired acute pyelonephritis (CA-APN) in South Korea between the period 2010–2011 and 2017–2018. We recruited all CA-APN patients aged ≥19 years who visited eight hospitals in South Korea from September 2017 to August 2018, prospectively. Data collected were compared with those from the previous study in 2010–2012, with the same design and participation from 11 hospitals. A total of 617 patients were enrolled and compared to 818 patients’ data collected in 2010–2011. Escherichia coli was the most common causative pathogen of CA-APN in both periods (87.3% vs. 86.5%, p = 0.680). E. coli isolates showed significantly higher antimicrobial resistance against fluoroquinolone (32.0% vs. 21.6%, p < 0.001), cefotaxime (33.6% vs. 8.3%, p < 0.001), and trimethoprim/sulfamethoxazole (37.5% vs. 29.2%, p = 0.013) in 2017–2018 than in 2010–2011. Total duration of antibiotic treatment increased from 16.55 ± 9.68 days in 2010–2011 to 19.12 ± 9.90 days in 2017–2018 (p < 0.001); the duration of carbapenem usage increased from 0.59 ± 2.87 days in 2010–2011 to 1.79 ± 4.89 days in 2010–2011 (p < 0.001). The median hospitalization was higher for patients in 2017–2018 than in 2010–2011 (9 vs. 7 days, p < 0.001). In conclusion, antimicrobial resistance of E. coli to almost all antibiotic classes, especially third generation cephalosporin, increased significantly in CA-APN in South Korea. Consequently, total duration of antibiotic treatment, including carbapenem usage, increased.

Determination of the time-dependent association between ciprofloxacin consumption and ciprofloxacin resistance using a weighted cumulative exposure model compared with standard models

OBJECTIVES

To obtain comprehensive insight into the association of ciprofloxacin use at different times in the past with the current risk of detecting resistance.

METHODS

This retrospective nested case-control study of ciprofloxacin users used Dutch data from the PHARMO Database Network and one laboratory for the period 2003-14. Cases and controls were selected as patients with an antibiotic susceptibility test (AST) indicating ciprofloxacin resistance or susceptibility, respectively. We performed univariable and multivariable conditional logistic regression analyses, defining time-dependent exposure using standard definitions (current ciprofloxacin use, used 0-30, 31-90, 91-180 and 181-360 days ago) and a flexible weighted cumulative effect (WCE) model with four alternative time windows of past doses (0-30, 0-90, 0-180 and 0-360 days).

RESULTS

The study population consisted of 230 cases and 909 controls. Under the standard exposure definitions, the association of ciprofloxacin use with resistance decreased with time [current use: adjusted OR 6.8 (95% CI 3.6-12.4); used 181-360 days ago: 1.3 (0.8-1.9)]. Under the 90 day WCE model (best-fitting model), more recent doses were more strongly associated with resistance than past doses, as was longer or repeated treatment. The 180 day WCE model, which fitted the data equally well, suggested that doses taken 91-180 days ago were also significantly associated with resistance.

CONCLUSIONS

The estimates for the association between ciprofloxacin use at different times and resistance show that ciprofloxacin prescribers should consider ciprofloxacin use 0-180 days ago to ensure that patients receive suitable treatment. The OR of ciprofloxacin resistance could be reduced by eliminating repeated ciprofloxacin prescription within 180 days and by treating for no longer than necessary.

Risk factors for quinolone-resistant Escherichia coli infection: a systematic review and meta-analysis

Background

Antimicrobial resistance to quinolone is rising worldwide, especially in Escherichia coli causing various infections. Although many studies have been conducted to identify the risk factors for quinolone-resistant Escherichia coli (QREC) infection, the results are inconsistent and have not been systematically reported. The aim of the present study is to conduct a systematic review and meta-analysis to evaluate the potential risk factors for QREC infection.

Methods

A systematic search was performed to collect published data in the EMBASE, PubMed, and the Cochrane Library up to April 2019. Risk factors were analyzed using the pooled odds ratio (ORs) with 95% confidence interval (CIs).

Results

Twenty-seven trials involving 67,019 participants were included in the present study. The following risk factors associated with QREC infection were identified: (1) male (OR = 1.41), (2) hepatic cirrhosis (OR = 2.05), (3) diabetes mellitus (OR = 1.62), (4) cardiovascular disease (OR = 1.76), (5) neurogenic bladder (OR = 8.66), (6) renal dysfunction (OR = 2.47), (7) transplantation (OR = 2.37), (8) urinary tract infection (OR = 2.79) and urinary tract abnormality (OR = 1.85), (9) dementia (OR = 5.83), (10) heart failure (OR = 5.63), (11) neurologic disease (OR = 2.80), (12) immunosuppressive drugs (OR = 2.02), (13) urinary catheter (OR = 4.39), (14) nursing home resident (OR = 4.63), (15) prior surgery (OR = 2.54), (16) quinolones (OR = 7.67), (17) other antibiotics (OR = 2.74), (18) hospitalization (OR = 2.06) and (19) nosocomial infection acquisition (OR = 2.35).

Conclusions

QREC infection was associated with nineteen risk factors including prior quinolones use, hospitalization, and several comorbidities. Reducing exposure to these risk factors and modification of antibiotic use are important to prevent quinolone resistance.

Bystander Selection for Antimicrobial Resistance: Implications for Patient Health

Antimicrobial therapy promotes resistance emergence in target infections and in off-target microbiota. Off-target resistance emergence threatens patient health when off-target populations are a source of future infections, as they are for many important drug-resistant pathogens. However, the health risks of antimicrobial exposure in off-target populations remain largely unquantified, making rational antibiotic stewardship challenging. Here, we discuss the contribution of bystander antimicrobial exposure to the resistance crisis, the implications for antimicrobial stewardship, and some novel opportunities to limit resistance evolution while treating target pathogens.

Fluoroquinolone consumption and Escherichia coli resistance in Japan: an ecological study

BACKGROUND

The frequency of antimicrobial resistance has steadily increased worldwide, induced by inappropriate use of antibiotics in a variety of settings. We analyzed the ecological correlation between fluoroquinolone consumption and levofloxacin resistance in Escherichia coli in Japan.

METHODS

We collected information on cases of E. coli resistant to levofloxacin in 2015-2016 in all 47 prefectures from the Japan Nosocomial Infections Surveillance system. Information on fluoroquinolone consumption was obtained from pharmaceutical sales data. To address potential confounding, we also collected information on the number of physicians, nurses, and medical facilities per 100,000 individuals.

RESULTS

We identified higher fluoroquinolone consumption and higher resistance in western prefectures, and lower consumption and resistance in eastern prefectures. Multivariate analysis identified a positive correlation between fluoroquinolone consumption and levofloxacin resistance in both 2015 and 2016.

CONCLUSIONS

Fluoroquinolone consumption and levofloxacin-resistant E. coli are potentially associated on a nationwide scale. The relationship between the two must be elucidated using additional studies with different epidemiological designs, so that any possible counter-measures, including alternative prescription, can be considered in the future.

Performance of an Easy and Simple New Scoring Model in Predicting Multidrug-Resistant Enterobacteriaceae in Community-Acquired Urinary Tract Infections

Background

Multidrug resistance (MDR) is a growing global problem in bacterial community-acquired urinary tract infections (CUTIs). We aimed to propose an easy-to-use clinical prediction model to identify patients with MDR in CUTI.

Methods

We conducted a retrospective study including 770 patients with documented CUTI diagnosed during 2010–2017. Logistic regression–based prediction scores were calculated based on variables independently associated with MDR. Sensitivities and specificities at various cutoff points were determined, and the area under the receiver operating characteristic curve (AUROC) was computed.

Results

We found MDR Enterobacteriaceae in 372 cases (45.1%). Multivariate analysis showed that age ≥70 years (adjusted odds ratio [aOR], 2.5; 95% confidence interval [CI], 1.8–3.5), diabetes mellitus (aOR, 1.65; 95% CI, 1.19–2.3), history of urinary tract surgery in the last 12 months (aOR, 4.5; 95% CI, 1.22–17), and previous antimicrobial therapy in the last 3 months (aOR, 4.6; 95% CI, 3–7) were independent risk factors of MDR in CUTI. The results of Hosmer-Lemshow chi-square testing were indicative of good calibration of the model (χ² = 3.4; P = .49). At a cutoff of ≥2, the score had an AUROC of 0.71, a sensitivity of 70.5%, a specificity of 60%, a positive predictive value of 60%, a negative predictive value of 70%, and an overall diagnostic accuracy of 65%. When the cutoff was raised to 6, the sensitivity dropped (43%), and the specificity increased appreciably (85%).

Conclusions

We developed a novel scoring system that can reliably identify patients likely to be harboring MDR in CUTI.

Relationship Between Antimicrobial Prescribing and Antimicrobial Resistance Among UTI Patients at Buraidah Central Hospital, Saudi Arabia

Introduction:

Most of the decisions regarding diagnosis and treatment are based on laboratory test results. Urinary tract infections (UTIs) are among the most common infections in humans. The changing antimicrobial sensitivity in UTI requires appropriate antibiotics. Antimicrobial resistance is an emerging problem in the Kingdom of Saudi Arabia where the complete reversal of antimicrobial resistance is difficult due to irrational use of antibiotics.

Objectives:

This study aimed to determine the most common bacterial agents causing UTI in different seasons among patients who were admitted to Buraidah Central Hospital (BCH), Saudi Arabia. The study also evaluated the link between prescribing and resistance toward antimicrobials.

Materials and Methods:

A 6-month retrospective study was conducted among adult patients who were admitted to the inpatient department at BCH. A total of 379 files were collected from microbiological laboratory for inpatients.

Results:

Most UTI-causing bacteria prevailed in the same season. Of 15 bacterial strains, 12 were significantly correlated with 20 (of a total of 40) antibiotics that were used. Most bacteria were gram-negative. Gram-negative bacilli including Escherichia coli, Klebsiella spp., and Pseudomonadaceae and gram-positive Enterococcus faecalis were most frequently causing UTIs.

Conclusion:

Overall prevalence of antibiotic resistance was negative in bacterial isolates. However, the relationship between antimicrobial prescribing and antimicrobial resistance was significantly negative among UTI patients in BCH, Saudi Arabia.

Comparison of antibiotics use, urinary tract infection (UTI)-causative bacteria and their antibiotic susceptibilities among 4 hospitals with different backgrounds and regions in Japan

In this study, we compared the antibiotic use, urinary tract infection-causative bacteria and their antibiotic susceptibilities among four hospitals with different backgrounds and regions in Japan in 2014. Frequency of antibiotic use (antibiotic use density: AUD/all AUD) were: ampicillin: 0.21-20.3 (median: 1.6) and cefazolin: 0.8-34.2 (2.5), representatively. The antibiotic resistant rates of Escherichia coli were ampicillin: 1.1-52.3% (median: 51.8%), piperacillin: 47.9-49.1% (48.0%), cefazolin: 23.2-34.1% (28.9%), levofloxacin: 36.6-43.8% (40.2%).We found that there were significant correlations (1) between antibiotic resistance of E. coli and annual total amount of antibiotic use (p = 0.017), annual number of days of antibiotic use (p = 0.002) and days of therapy (DOT, p = 0.002), and (2) between antibiotic resistance of extended-spectrum β-lactamase-producing bacteria and annual number of days of antibiotic use (p = 0.004) and DOT (p = 0.004) in a rehabilitation hospital. These results suggested that more antibiotic uses could lead to antibiotic resistances. Further analyses with more number of data are being undertaken.

Antibacterial Resistance in Ureaplasma Species and Mycoplasma hominis Isolates from Urine Cultures in College-Aged Females

Urinary tract infections (UTIs) affect nearly 20% of women age 15 to 29 and account for an estimated $3.5 billion in costs. Antibiotic resistance prolongs UTI treatment, and resistance profiles vary regionally. This regional variation is an important consideration in guiding empirical treatment selection. Regional studies in the United States have identified tetracycline resistance in over one-third of Ureaplasma species isolates, but no studies have evaluated antibiotic resistance levels in college-aged women with a first-time UTI. We tested a panel of antibiotics and determined the MICs of Ureaplasma species (60 U. parvum and 13 U. urealyticum) and 10 Mycoplasma hominis isolates obtained from urine from college-aged women with a first-time UTI. Low antibiotic resistance was found in this population of women with a first-time UTI. All M. hominis and U. urealyticum isolates were sensitive. However, two U. parvum isolates were resistant, with one to levofloxacin (MIC, 4 μg/ml) and one to tetracycline (MIC, 8 μg/ml). For the Ureaplasma spp., the MIC₉₀s were highest against gentamicin (21 μg/ml) and lowest against doxycycline (0.25 μg/ml). In a comparison of MIC levels between Ureaplasma spp., U. urealyticum had significantly higher MICs against each antibiotic except doxycycline. For the resistant isolates, the genetic mechanisms of resistance were determined. PCR amplification identified tetM to be present in the tetracycline-resistant isolate and an S83W mutation within the parC gene of the quinolone-resistant isolate. To our knowledge, this study is the first to provide molecular and phenotypic evidence of the S83W parC mutation conferring levofloxacin resistance in U. parvum isolated from a patient in the United States.

Social and economic burden of recurrent urinary tract infections and quality of life: a patient web-based study (GESPRIT)

BACKGROUND

Uncomplicated lower urinary tract infections (UTIs) occur in approximately 50% of women, and 20-30% experience recurrent UTI. Data on UTIs and quality of life (QoL) in Europe are limited.

METHODS

This was an anonymous, self-administered web-based survey conducted in 5 countries (Germany, Switzerland, Poland, Russia and Italy), on adult women who had experienced recurrent UTI and were affected by acute UTI currently or within 4 weeks of study entry. Questions covered disease course; management; social and economic burden; education, income, and health insurance status. QoL was evaluated using the SF-12v2.

RESULTS

Participants reported a mean of 5.15 UTI symptoms, ranging from 4.85 - 5.38 in Russia and Germany. There was a mean of 2.78 doctor visits per year (1.74 - 3.71 in Russia and Germany; p < 0.0001). 80.3% of participants had been treated with antibiotics, mean prescriptions ranged from 2.17 (Poland) to 3.36 (Germany) per person per year. A mean of 3.09 days sick leave due to UTIs, and 3.45 days of limited activities, were reported. Although 73.8% of participants had tried prophylaxis recurrence was common and associated with mental stress for a high proportion of women.

CONCLUSIONS

Our results indicate that recurrent UTIs have a significant impact on QoL of women in Europe.

Immunity to uropathogens: the emerging roles of inflammasomes

Urinary tract infections (UTIs) cause a huge burden of morbidity worldwide with recurrent UTIs becoming increasingly frequent owing to the emergence of antibiotic-resistant bacterial strains. Interactions between the innate and adaptive immune responses to pathogens colonizing the urinary tract have been the focus of much research. Inflammasomes are part of the innate immune defence and can respond rapidly to infectious insult. Assembly of the multiprotein inflammasome complex activates caspase-1, processes proinflammatory cytokines IL-1β and IL-18, and induces pyroptosis. These effector pathways, in turn, act at different levels to either prevent or resolve infection, or eliminate the infectious agent itself. In certain instances, inflammasome activation promotes tissue pathology; however, the precise functions of inflammasomes in UTIs remain unexplored. An improved understanding of inflammasomes could provide novel approaches for the design of diagnostics and therapeutics for complicated UTIs, enabling us to overcome the challenge of drug resistance.

High Rate of Multidrug-Resistant Gram-Negative Bacilli Carriage and Infection in Hospitalized Returning Travelers: A Cross-Sectional Cohort Study

BACKGROUND

Carriage of and infection with multidrug-resistant Gram-negative bacilli (MDR-GNB) are a potential cause of concern in travelers with no history of hospitalization abroad.

METHODS

All consecutive returning travelers hospitalized in our department between February 2012 and January 2013 were prospectively screened for MDR-GNB gastrointestinal tract carriage or infection. We compared the prevalence of MDR-GNB in travelers to a non-travelers nonexposed group. Then among the travelers, MDR-GNB carriers were compared to noncarriers to determine risk factors of acquisition of MDR-GNB.

RESULTS

Overall, 359 patients (191 travelers, 168 non-travelers) were included, and 25 (6.4%), including 23 travelers, harbored MDR-GNB. Five travelers had an MDR-GNB infection while 18 were asymptomatic enteric carriers. MDR-GNB carriage or infection was significantly more frequent in travelers (11.0% vs 1.2% for non-travelers, odds ratio (OR) = 11.3, p < 0.001) and in patients born outside France (OR = 1.67; p = 0.03). Among travelers, in multivariate analysis, factors independently associated with MDR-GNB carriage or infection were traveling to Asia (OR = 3.1; p = 0.01) and visiting friends and relatives (VFR) or migrants (OR=3.6; p = 0.01).

CONCLUSIONS

The 10-fold higher prevalence rate of MDR-GNB in travelers raises the issues of systematic screening of all travelers, and of the choice of first line antibiotic therapy when treating urinary tract infections in travelers, especially those VFR, migrants, and those returning from Asia.

An outbreak of multi-drug resistant Escherichia coli urinary tract infection in an elderly population: a case-control study of risk factors

BACKGROUND

Prevention of infection due to multi-drug resistant organisms is particularly challenging because of the spread of resistant bacteria beyond hospitals into the community, including nursing homes. This study aimed to identify risk factors for the acquisition of a multidrug resistant (MDR) Escherichia coli in a local outbreak.

METHODS

Study participants were all aged over 65 years. Cases had the MDR E. coli isolated from a routine urine sample, and controls had a urine sample submitted to the laboratory in the same time period but the MDR E. coli was not isolated. Information from clinical records was used to identify risk factors both in the hospital and the community setting for acquisition of the MDR E. coli.

RESULTS

76 cases and 156 controls were identified and included in the study. In a multivariate analysis, risk factors statistically significantly associated with acquisition of the MDR E. coli were female gender (adjusted OR 3.2; 95 % confidence interval 1.5-6.9), level of care (high dependency OR 7.5; 2.2-25.7) compared with living independently), and in hospital prescription of antimicrobials to which the MDR E. coli was resistant (OR 5.6; 2.5-12.9).

CONCLUSIONS

The major risk factors for the acquisition of a MDR E. coli were found to be residence in a nursing home and in-hospital prescription of antimicrobials to which the MDR E. coli was resistant. This emphasises that prevention of transmission of MDROs within a community needs to involve both hospitals and also other healthcare organizations, in this case nursing homes.

Value of an aggregate index in describing the impact of trends in antimicrobial resistance for Escherichia coli

Typically, rates of resistance to various antibiotics in a given pathogen are assessed for a single drug at a time, in the setting of a particular type of infection. A more cohesive analysis is the drug resistance index, which incorporates resistance to multiple drugs for a given pathogen. The authors of this article developed a drug resistance index for Escherichia coli causing urinary tract infections in British Columbia.

BACKGROUND:

Drug resistance indexes (DRIs) quantify the cumulative impact of antimicrobial resistance on the likelihood that a given pathogen will be susceptible to antimicrobial therapy.

OBJECTIVE:

To derive a DRI for community urinary tract infections caused by Escherichia coli in British Columbia for the years 2007 to 2010, and to examine trends over time and across patient characteristics.

METHODS:

Indication-specific utilization data were obtained from BC PharmaNet for outpatient antimicrobial prescriptions linked to diagnostic information from physician payment files. Resistance data for E coli urinary isolates were obtained from BC Biomedical Laboratories (now part of LifeLabs Medical Laboratory Services). DRIs were derived by multiplying the rate of resistance to a specific antimicrobial by the proportional rate of utilization for that drug class and aggregating across drug classes. Higher index values indicate more resistance.

RESULTS:

Adaptive-use DRIs remained stable over time at approximately 18% (95% CI 17% to 18%) among adults ≥15 years of age and approximately 28% (95% CI 26% to 31%) among children <15 years of age. Similar results were observed when proportional drug use was restricted to the baseline year (ie, a static-use model). Trends according to age group suggest a U-shaped distribution, with the highest DRIs occurring among children <10 years of age and adults ≥65 years of age. Males had consistently higher DRIs than females for all age groups.

CONCLUSIONS:

The stable trend in adaptive-use DRIs over time suggests that clinicians are adapting their prescribing practices for urinary tract infections to local resistance patterns. Results according to age group reveal a higher probability of resistance to initial therapy among young children and elderly individuals.

Antibacterial susceptibility of Escherichia coli among outpatients with community-acquired urinary tract infection in Hamadan, Iran

Escherichia coli is the main cause of community-acquired urinary tract infections (UTIs). The aims of the present study were to examine the susceptibility profile of E. coli causing UTIs and to identify factors associated with antimicrobial resistance. A cross-sectional study was conducted in Hamadan City, Iran, between 2012 and 2013. Patients referred to Farshchian or Shahid Beheshti Hospitals and diagnosed with UTI caused by E. coli were enrolled in the study. Susceptibility testing to commonly used antimicrobial agents was performed by the disk diffusion method. Relevant data were abstracted, and analysis was performed to identify factors associated with antimicrobial resistance. A total of 154 patients were enrolled in the study. Among the respective number of E. coli isolates, the highest susceptibility was observed to nitrofurantoin (94.1%) and gentamicin (86.4%) and the lowest to amoxicillin/clavulanic acid (35.1%), trimethoprim/sulfamethoxazole (38.3%) and ciprofloxacin (51.9%). Twenty-four isolates (15.6%) were susceptible to all antimicrobial tested, 31 (20.1%) were resistant to one agent and 99 (64.3%) exhibited resistance to at least two different classes of antibiotics [multidrug-resistant (MDR) phenotype]. Patients with prior use of antibiotics during the past 3 months and those who had an episode of UTI in the past 2 years were at higher risk of being infected with MDR E. coli (P=0.034 and P=0.001, respectively). In conclusion, a substantial proportion of E. coli causing UTI exhibited a MDR phenotype. History of UTI and prior use of antibiotics were associated with increased risk of infection caused by MDR E. coli.

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.

Occurrence of multidrug resistance to oral antibiotics among Escherichia coli urine isolates from outpatient departments in Germany: extended-spectrum β-lactamases and the role of fosfomycin

The in vitro activities of fosfomycin and seven other antibiotics commonly used for oral treatment of urinary tract infections (UTIs) were evaluated for 499 Escherichia coli isolated from urine samples during a nationwide laboratory-based surveillance study in 2010. Overall, the highest resistance rates were found for amoxicillin (42.9%), followed by amoxicillin/clavulanic acid (32.7%), trimethoprim/sulfamethoxazole (SXT) (30.9%), ciprofloxacin (19.8%), cefuroxime (10.0%), cefpodoxime (8.6%) and cefixime (8.2%). One-half of the isolates (n=252; 50.5%) were fully susceptible to the eight drugs, whilst only 6 strains (1.2%) were resistant to fosfomycin. Combined resistance to amoxicillin, cefuroxime, ciprofloxacin and SXT was detected in 29 isolates (5.8%). Moreover, 40 isolates (8.0%) produced an extended-spectrum β-lactamase (ESBL), including CTX-M-type ESBLs detected in 39/40 isolates (97.5%) and a TEM-52 ESBL in 1 strain (2.5%). The predominant CTX-M-type ESBL was CTX-M-15 (27/39; 69.2%). Of the 27 CTX-M-15 producers, 19 (70.4%) belonged to the clonal lineage E. coli O25b-ST131. All but one ESBL-producing strains were fosfomycin-susceptible. In view of the emergence of multidrug resistance to standard oral antibiotics, these data support that oral fosfomycin (trometamol salt) may represent a valuable option in the treatment of uncomplicated UTIs.

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.

[The challenge of infections and multiresistant bacteria among the elderly living in long-term care facilities]

Healthcare-associated infections not only affect patients in acute care hospitals but also patients in need of long-term care. As the elderly are generally most affected, the demographic change in Germany faces a range of increasing challenges in the field of infection control. The ageing process itself is accompanied by several physiological and pathological changes which may result in an increase in the risk of infectious diseases. Elderly living in long-term care facilities (LTCFs) may in addition be exposed to further risks due to their everyday life in a community, nursing care and the, to some extent, inappropriate use of antibiotics. Bacteria that have become resistant to commonly used antimicrobial agents are meanwhile prevalent in nursing homes. Caregivers often feel left alone when facing the task of achieving a balance between the need for a comfortable familiar environment and the application of infection control measures according to a resolute prevention strategy. This review aims to give an overview about the characteristics of infections among the elderly, especially with respect to long-term care.

Impact of antibiotic use during hospitalization on the development of gastrointestinal colonization with Escherichia coli with reduced fluoroquinolone susceptibility

OBJECTIVE

Infections due to fluoroquinolone-resistant Escherichia coli (FQREC) are associated with significant morbidity and mortality. Fluoroquinolone resistance likely arises at the level of gastrointestinal colonization. The objective of this study was to identify risk factors for the development of FQREC gastrointestinal tract colonization in hospitalized patients, including the impact of antibiotics prescribed during hospitalization.

DESIGN

A prospective cohort study was conducted from 2002 to 2004 within a university health system.

METHODS

Hospitalized patients initially colonized with fluoroquinolone-susceptible E. coli were followed up with serial fecal sampling for new FQREC colonization or until hospital discharge or death. A Cox proportional hazards regression model was developed to identify risk factors for new FQREC colonization, with antibiotic exposure modeled as time-varying covariates.

RESULTS

Of 395 subjects, 73 (18.5%) became newly colonized with FQREC. Length of stay before sampling (hazard ratio [HR], 1.02 [95% confidence interval (CI), 1.1-1.03]; P = .003) and malignancy (HR, 0.37 [95% CI, 0.21-0.67]; P = .001) were significantly associated with the development of FQREC colonization. In addition, receipt of a first-generation cephalosporin (HR, 1.19 [95% CI, 1.10-1.29]; P < .001) or cefepime (HR, 1.05 [95% CI, 1.00-1.10]; P = .048) during hospitalization increased the risk of new FQREC colonization.

CONCLUSIONS

The acquisition of FQREC in the hospital setting is complex, and antimicrobial stewardship programs should take into account patterns of antibiotic use in implementing strategies to reduce the development of new FQREC colonization. Future studies are needed to identify risk factors for infection in hospitalized patients newly colonized with FQREC.

Healthcare-associated, community-acquired and hospital-acquired bacteraemic urinary tract infections in hospitalized patients: a prospective multicentre cohort study in the era of antimicrobial resistance

The clinical and microbiological characteristics of community-onset healthcare-associated (HCA) bacteraemia of urinary source are not well defined. We conducted a prospective cohort study at eight tertiary-care hospitals in Spain, from October 2010 to June 2011. All consecutive adult patients hospitalized with bacteraemic urinary tract infection (BUTI) were included. HCA-BUTI episodes were compared with community-acquired (CA) and hospital-acquired (HA) BUTI. A logistic regression analysis was performed to identify 30-day mortality risk factors. We included 667 episodes of BUTI (246 HCA, 279 CA and 142 HA). Differences between HCA-BUTI and CA-BUTI were female gender (40% vs 69%, p <0.001), McCabe score II-III (48% vs 14%, p <0.001), Pitt score ≥2 (40% vs 31%, p 0.03), isolation of extended spectrum β-lactamase-producing Enterobacteriaciae (13% vs 5%, p <0.001), median hospital stay (9 vs 7 days, p 0.03), inappropriate empirical antimicrobial therapy (21% vs 13%, p 0.02) and mortality (11.4% vs 3.9%, p 0.001). Pseudomonas aeruginosa was more frequently isolated in HA-BUTI (16%) than in HCA-BUTI (4%, p <0.001). Independent factors for mortality were age (OR 1.04; 95% CI 1.01-1.07), McCabe score II-III (OR 3.2; 95% CI 1.8-5.5), Pitt score ≥2 (OR 3.2 (1.8-5.5) and HA-BUTI OR 3.4 (1.2-9.0)). Patients with HCA-BUTI are a specific group with significant clinical and microbiological differences from patients with CA-BUTI, and some similarities with patients with HA-BUTI. Mortality was associated with patient condition, the severity of infection and hospital acquisition.

Risk factors associated with group B streptococcus resistant to clindamycin and erythromycin in pregnant korean women

Background

The prevalence of group B streptococcus (GBS) among pregnant women and neonates in the Republic of Korea has increased. In addition, rates of resistance to antibiotics recommended for pregnant women allergic to penicillin, such as clindamycin and erythromycin, have increased. The aim of this study was to evaluate subject characteristics associated with GBS resistance to clindamycin and erythromycin.

Materials and Methods

A total of 418 clinical isolates from pregnant women in Korea were screened for antibiotic resistance from January 2006 to December 2011. Sociodemographic information, medical and obstetric history, and details of events during the previous 2 weeks were recorded using a standardized questionnaire.

Results

The resistance rates were 39.5% for clindamycin and 23.0% for erythromycin. In multiple logistic regression analysis, the subject characteristic significantly associated with resistance to both antibiotics was a history of symptomatic sore throat in the 2 weeks before obtaining the specimen (erythromycin: odds ratio [OR]: 2.13, 95% confidence interval [CI]: 1.10 to 4.13; clindamycin: OR: 2.31, 95% CI: 1.21, 4.42). Premature rupture of membranes (PROM) had an association of borderline significance.

Conclusions

In the urgent treatment of GBS-colonized pregnant women, the subject's history of previous sore throat and PROM should be considered when choosing appropriate antibiotics.

Epidemiological interpretation of studies examining the effect of antibiotic usage on resistance

Bacterial resistance to antibiotics is a growing clinical problem and public health threat. Antibiotic use is a known risk factor for the emergence of antibiotic resistance, but demonstrating the causal link between antibiotic use and resistance is challenging. This review describes different study designs for assessing the association between antibiotic use and resistance and discusses strengths and limitations of each. Approaches to measuring antibiotic use and antibiotic resistance are presented. Important methodological issues such as confounding, establishing temporality, and control group selection are examined.

Comparison of the bacterial isolates and antibiotic resistance patterns of elderly nursing home and general community patients

BACKGROUND

Nursing home-acquired infections may differ from general community-acquired infections in bacteriology and antibiotic resistance. However, there are currently limited data on this topic in the Australian setting.

AIMS

To compare bacterial isolates and antibiotic resistance patterns, from pathology specimens of nursing home and community patients, and to comment on the suitability of empiric antibiotic guidelines for nursing home-acquired infection.

METHODS

This was a retrospective cohort study of patients, aged ≥ 65 years, who resided in either nursing homes or the general community. Patients with a hospital admission in the previous 28 days were excluded. Positive specimen cultures, collected between July 2003 and June 2008 in the Emergency Department and Outpatient Clinics of the Austin Hospital (Melbourne), were examined. The main outcome measures were the bacterial isolates, and their antibiotic resistance patterns, of patients from nursing homes and the general community.

RESULTS

Specimens of blood (638), sputum (425), urine (4044) and wound cultures (785) were examined. The bacteriology of blood culture isolates did not differ between the two groups (P= 0.3). However, the bacteriology of sputum, urine and wound cultures differed significantly between the groups (P= 0.025, P < 0.001, P= 0.004 respectively). There were also higher proportions of antibiotic resistance among some bacteria in nursing home patients, especially methicillin resistance among Staphylococcus aureus isolates across all specimen types, and resistance to several empiric antibiotics among Enterobacteriaceae isolates in urine cultures.

CONCLUSION

Empiric antibiotic guidelines appear adequate to treat nursing home-acquired septicaemia and pneumonia. However, guidelines for urinary tract infections and wound infections may need to be refined.

Clinical characteristics of community-acquired acute pyelonephritis caused by ESBL-producing pathogens in South Korea

OBJECTIVES

The aim of this study was to determine the risk factors and clinical characteristics of community-acquired acute pyelonephritis (CA-APN) caused by extended-spectrum β-lactamase (ESBL)-producing organisms.

METHODS

From March 2010 to February 2011, patients with CA-APN were recruited in 11 hospitals in South Korea. Clinical and microbiological data were collected prospectively, and the ESBLs and multilocus sequence types of the ESBL-producing Escherichia coli were characterized. Comparison between CA-APN caused by ESBL-producing Enterobacteriaceae and those by non-ESBL-producing organisms was performed.

RESULTS

A total of 566 patients were recruited. Enterobacteriaceae were detected in 526 patients. Forty-six isolates (46/526, 8.7 %) were positive for ESBLs. Clinical and microbiological failure did not differ between the two groups, despite there being fewer patients with ESBL-positive isolates provided with appropriate antibiotics initially (19.6 vs. 93.8 %, p < 0.001). However, the duration of hospitalization was longer in the ESBL group (10.5 vs. 7.0 days, p = 0.012). In a logistic regression model, Charlson score ≥1 point [odds ratio (OR) 3.4, 95 % confidence interval (CI) 1.6-7.0, p = 0.001], antibiotics usage during the previous year (OR 3.1, 95 % CI 1.4-7.2, p = 0.008), and urinary catheterization during the previous month (OR 4.4, 95 % CI 1.1-17.6, p = 0.035) were associated with the risks of CA-APN by ESBL producers. CTX-M-15 (48 %) and CTX-M-14 (38 %) were the most common ESBLs. ST131 was the most common clone (7/24, 29.1 %), which was more frequently resistant to cefepime, fosfomycin, and temocillin.

CONCLUSIONS

The risk factors for CA-APN by ESBL producers were Charlson score ≥1 point, antibiotics usage during the previous year, and urinary catheterization during the previous month.

Antimicrobial resistance and spread of multi drug resistant Escherichia coli isolates collected from nine urology services in the Euregion Meuse-Rhine

We determined the prevalence and spread of antibiotic resistance and the characteristics of ESBL producing and/or multi drug resistant (MDR) Escherichia coli isolates collected from urine samples from urology services in the Euregio Meuse-Rhine, the border region of the Netherlands (n = 176), Belgium (n = 126) and Germay (n = 119). Significant differences in resistance between the three regions were observed. Amoxicillin-clavulanic acid resistance ranged from 24% in the Netherlands to 39% in Belgium (p = 0.018), from 20% to 40% (p<0.004) for the fluoroquinolones and from 20% to 40% (p = 0.018) for the folate antagonists. Resistance to nitrofurantoin was less than 5%. The prevalence of ESBL producing isolates varied from 2% among the Dutch isolates to 8% among the German ones (p = 0.012) and were mainly CTX-M 15. The prevalence of MDR isolates among the Dutch, German and Belgian isolates was 11%, 17% and 27%, respectively (p< = 0.001 for the Belgian compared with the Dutch isolates). The majority of the MDR and ESBL producing isolates belonged to ST131. This study indicates that most antibiotics used as first choice oral empiric treatment for UTIs (amoxicillin-clavulanic acid, fluoroquinolones and folate antagonists) are not appropriate for this purpose and that MDR strains such as CTX-M producing ST131 have spread in the entire Euregion. Our data stress the importance of ward specific surveillance to optimize empiric treatment. Also, prudent use of antibiotics and further research to alternative agents are warranted.

A prospective, randomized, double dummy, placebo-controlled trial of oral cefditoren pivoxil 400mg once daily as switch therapy after intravenous ceftriaxone in the treatment of acute pyelonephritis

OBJECTIVES

To compare the clinical and bacteriological effectiveness of intravenous (IV) ceftriaxone followed by oral cefditoren pivoxil or IV ceftriaxone for acute pyelonephritis.

METHODS

A prospective randomized controlled trial of patients with a presumptive diagnosis of acute pyelonephritis was performed. Daily 2g IV ceftriaxone was initially given to all patients. After day 3, patients who satisfied the criteria for switch therapy were randomized to either group A (IV ceftriaxone) or group B (oral cefditoren pivoxil 400mg once daily).

RESULTS

Eighty-two patients were enrolled; 41 (50%) patients in group A and 41 (50%) patients in group B were evaluated. There was no statistically significant difference in baseline characteristics between the two groups. Clinical cure was observed in 39 of 41 (95.1%) patients in group A and 41 of 41 (100%) patients in group B (p=0.15, 95% confidence interval (CI) -0.12 to 0.02). Urine bacteriological eradication was found in 63.4% in group A and 60% in group B (p=0.75, 95% CI -0.18 to 0.25). There was no statistically significant difference in adverse effects between the two treatment groups.

CONCLUSION

These data suggest that IV ceftriaxone followed by oral cefditoren pivoxil is highly effective and well-tolerated for the treatment of acute pyelonephritis, even for uropathogens with a high proportion of quinolone-resistant strains.

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

OBJECTIVES

Individual and group level factors associated with the probability of antimicrobial resistance of uropathogenic Escherichia coli were analysed in a multilevel model.

METHODS

Adult patients consulting with a suspected urinary tract infection (UTI) in 22 general practices over a 9 month period supplied a urine sample for laboratory analysis. Cases were patients with a UTI associated with a resistant E. coli. Previous antimicrobial exposure and other patient characteristics were recorded from the medical files.

RESULTS

Six hundred and thirty-three patients with an E. coli UTI and a full record for all variables were included. Of the E. coli isolates, 36% were resistant to trimethoprim and 12% to ciprofloxacin. A multilevel logistic regression model was fitted. The odds that E. coli was resistant increased with increasing number of prescriptions over the previous year for trimethoprim from 1.4 (0.8-2.2) for one previous prescription to 4.7 (1.9-12.4) for two and 6.4 (2.0-25.4) for three or more. For ciprofloxacin the ORs were 2.7 (1.2-5.6) for one and 6.5 (2.9-14.8) for two or more. The probability that uropathogenic E. coli was resistant showed important variation between practices and a difference of 17% for trimethoprim and 33% for ciprofloxacin was observed for an imaginary patient moving from a practice with low to a practice with high probability. This difference could not be explained by practice prescribing or practice resistance levels.

CONCLUSIONS

Previous antimicrobial use and the practice visited affect the risk that a patient with a UTI will be diagnosed with an E. coli resistant to this agent, which was particularly important for ciprofloxacin.

Community-onset healthcare-related urinary tract infections: comparison with community and hospital-acquired urinary tract infections

OBJECTIVES

To analyze the characteristics of infection, adequacy of empirical treatment and outcome of patients with community-onset healthcare-associated (HCA) urinary tract infections (UTI) and compare them with hospital (HA) and community-acquired (CA) UTI.

METHODS

Prospective observational cohort study performed at a university 600-bed hospital between July 2009 and February 2010. Patients with UTI requiring hospital admission were included. Epidemiological, clinical and outcome data were recorded.

RESULTS

251 patients were included. Patients with community-onset HCA UTI were older, had more co-morbidities and had received previous antimicrobial treatment more frequently than CA UTI (p = 0.02, p = 0.01 and p < 0.01). ESBL-Escherichia coli and Pseudomonas aeruginosa infections were more frequent in HCA than in CA UTI (p = 0.03 and p < 0.01). Inadequate empirical treatment was not significantly different between community-onset HCA and CA. Factors related to mortality were P. aeruginosa infection (OR 6.51; 95%CI: 1.01-41.73), diabetes mellitus (OR 22.66; 95%CI: 3.61-142.21), solid neoplasia (OR 22.48; 95%CI: 3.38-149.49) and age (OR 1.15; 95%CI 1.03-1.28).

CONCLUSIONS

Epidemiological, clinical and microbiological features suggest that community-onset HCA UTI is different from CA and similar to HA UTI. However, in our series inadequate empirical antimicrobial therapy and mortality were not significantly higher in community-onset HCA than in CA UTI.

Prevalence and risk factors for quinolone resistance among Escherichia coli strains isolated from males with community febrile urinary tract infection

The purpose of this study was to evaluate the prevalence and clinical risk factors for quinolone resistance (QR) in E. coli strains from males with febrile urinary tract infection (FUTI). An ambispective cross-sectional study was performed in which we evaluated 153 males with a community FUTI caused by E. coli. Among the 153 FUTI episodes, 101 (66%) were due to quinolone susceptible E. coli strains while 52 (34%) were caused by QR E. coli strains. In the univariate analysis QR was associated with older age, higher Charlson scores, dementia, past UTI, urinary tract abnormalities, previous antibiotic use, particularly with fluoroquinolones (FQ), a healthcare-associated (HA)-UTI (HA-UTI) and to four of the components included in the definition of HA-UTI: hospital admission, nursing home residence, indwelling urethral catheter and invasive urinary instrumentation. In the multivariate analysis, HA-UTI (OR 3.82, 95% CI 1.3-11.24; P 0.015) and use of antimicrobials in the previous month (OR 5.82, 95% CI 2.3-14.88; P < 0.001) mainly with FQ (OR 13.97, 95% CI 2.73-71.53; P 0.002) were associated with QR. To have a HA-UTI and a previous use of FQ in the preceding month were strong risk factors for QR E. coli, and thus empirical antimicrobial treatment with quinolones should be avoided in these patients.

Chronological change of antibiotic use and antibiotic resistance in Escherichia coli causing urinary tract infections

Overuse of antibiotics can cause the emergence of resistant bacterial strains. This study retrospectively investigated recent trends in Escherichia coli causing urinary tract infections (UTIs), focusing on antibiotic use and antibiotic susceptibilities. Patients diagnosed with UTIs caused by E. coli in Akashi Municipal Hospital between April 2004 and March 2010 were enrolled in the study. A total of 858 UTI cases were examined. Antibiotics used in our hospital during that period and the antibiotic susceptibilities of E. coli in UTI cases were assessed. We analyzed the data on a yearly basis, with the year being defined as the period from April to the following March (e.g., in this study the period from April 2004 to March 2005 represents 2004). The first 3 years (2004-2006) were compared to the last 3 years (2007-2009). The use of piperacillin, cephazolin, amikacin, oral cefotiam, and levofloxacin decreased significantly and the use of imipenem, gentamicin (GM), cefcapene, and oral minocycline (MINO) increased significantly in the last 3 years compared to the previous 3 years. The susceptibilities of MINO in complicated cystitis significantly increased and those of GM in uncomplicated pyelonephritis significantly decreased in these 3 years (2007-2009) compared to the previous 3 years (2004-2006) (P < 0.05). Additionally, extended-spectrum β-lactamase (ESBL)-producing E. coli tended to be isolated more often; this was statistically significant in the last 3 years (2007-2009) compared to the previous 3 years (2004-2006) (P < 0.05). In conclusion, we found changes in our pattern of antibiotic use associated with changes in antibiotic susceptibilities and an increase in ESBL-producing E. coli isolated from our UTI cases. Monitoring of antibiotic use and emergence of resistant strains should be continued.

The epidemiology of urinary tract infection

Urinary tract infections (UTIs) are among the most common bacterial infections acquired in the community and in hospitals. In individuals without anatomical or functional abnormalities, UTIs are generally self limiting, but have a propensity to recur. Uropathogens have specialized characteristics, such as the production of adhesins, siderophores and toxins that enable them to colonize and invade the urinary tract, and are transmitted between individuals both through person-to-person contact and possibly via food or water. Although generally self limiting, treatment of UTIs with antibiotics leads to a more rapid resolution of symptoms and is more likely to clear bacteriuria, but also selects for resistant uropathogens and commensal bacteria and adversely affects the gut and vaginal microbiota. As uropathogens are increasingly becoming resistant to currently available antibiotics, it may be time to explore alternative strategies for managing UTI.

Epidemiology of ciprofloxacin resistance and its relationship to extended-spectrum β-lactamase production in Proteus mirabilis bacteremia

BACKGROUND/AIMS

We evaluated the clinical features of ciprofloxacin-resistant Proteus mirabilis bacteremia and risk factors for ciprofloxacin resistance.

METHODS

From October 2000 to July 2009, 37 patients with clinically significant P. mirabilis bacteremia were identified and data from patients with ciprofloxacin-resistant and ciprofloxacin-susceptible P. mirabilis bacteremia were compared.

RESULTS

The most common underlying diseases were neurologic disease (37.8%) and solid tumors (29.7%). The most common site of infection was the urinary tract (35.1%). Ten of the 37 patients (27.0%) were infected with ciprofloxacin-resistant isolates, and univariate analysis revealed a significant relationship between ciprofloxacin-resistant P. mirabilis bacteremia and neurologic disease, recent operation, L-tube insertion, percutaneous tube use, and extended-spectrum β-lactamase (ESBL) production (all p < 0.05). ESBL was detected in six of 10 (60%) ciprofloxacin-resistant isolates, while only three of 27 (11%) ciprofloxacin-susceptible isolates produced ESBL (p = 0.005). In a logistic regression analysis, ESBL production remained a significant factor associated with ciprofloxacin resistance, after adjusting for other variables.

CONCLUSIONS

These data indicate a close association between ciprofloxacin resistance and ESBL-production in P. mirabilis bacteremia. This association is particularly troublesome because the therapeutic options for serious infections caused by ESBL-producing P. mirabilis are severely restricted.