Risk Factors For Fluoroquinolone Resistance Research Articles

Modeling the risk of fluoroquinolone resistance in non-severe community-onset pyelonephritis.

Estimating whether the individual probability of being infected by a fluoroquinolone resistant isolate is higher than 10% may help to choose the empirical treatment of pyelonephritis. We aimed to model the risk of fluoroquinolone resistance in women with community-onset pyelonephritis. Women with non-severe community-onset pyelonephritis were prospectively recruited in 4 French emergency departments of 2 districts. Adjusted odds ratios (aOR) and 95% confidence intervals were estimated through multivariate logistic regression. Among 190 patients, 19 (10%) were infected by a fluoroquinolone resistant isolate. Fluoroquinolone resistance was more frequent in district #2 (17%) than in district #1 (3%). Independent risk factors for fluoroquinolone resistance were district (adjusted OR, 7.0 (2.2-31.9)), and in the 6 previous months, urinary tract infection (UTI, aOR, 3.9 (1.3-11.5)) and vesical catheterization (aOR, 4.7 (0.5-33.3)). A specific model was derived to identify district #2 patients with a low (10% or lower) probability of being infected by a fluoroquinolone resistant isolate. Independent risk factors were residency in long-term care facility (aOR, 3.3 (0.7-13.5)), and in the 6 previous months, UTI (adjusted OR, 3.1 (0.9-10.7)) and home nursing care (aOR, 3.4 (0.6-17.0)). For 63 (67%) patients, the predicted probability of fluoroquinolone resistance was 0.10; among these patients, 6 (10%) actually had a fluoroquinolone resistant isolate. Locally derived predictive models may be used to identify patients with a low probability of fluoroquinolone resistance and guide the empirical antimicrobial therapy of non-severe community-onset pyelonephritis.

Ciprofloxacin-Resistant Bacteria on Pre-Prostate Biopsy Rectal Swab Culture: A Northwest Ohio Study.

Ciprofloxacin is given to patients routinely prior to trans-rectal prostate biopsy. However bacterial resistance to this antibiotic has increased nationally resulting in increased infectious complications after prostate biopsy. In our study we aimed to quantify the percentage of older northwestern Ohio males harboring ciprofloxacin-resistant bacteria in the rectal vault and to assess if resistance is increasing over time. After Institutional Review Board approval, a retrospective chart review of all patients who underwent rectal swab culture within the Department of Urology at The University of Toledo Medical Center between January 1, 2012 and December 31, 2015 was completed. Patient demographic data were collected including the presence of ciprofloxacin resistance bacteria. To test for significant differences, χ2 and analysis of variance (ANOVA) analyses were completed where applicable. During the study period 311 swabs for resistant organisms were completed. The average age at time of swab was 64 (± 8.7 standard deviation [SD]) years old. Resistance rates were 13.2%, 13.8%, 19.5%, and 13.3% in 2012, 2013, 2014, and 2015, respectively. We found no statistically significant difference in resistances across years. Additionally, previous biopsy and age were not associated with ciprofloxacin resistance. Resistance to ciprofloxacin in the rectal vaults of older northwestern Ohio males is significant but appears to be stable over the study period. Previous biopsy and increased age do not appear to be risk factors for fluoroquinolone resistance. Given the relatively high rate of resistance in our population we recommend rectal swabs prior to prostate biopsy to assist in antibiotic agent choice.

Prevalence of fluoroquinolone-resistant rectal flora in patients undergoing transrectal ultrasound-guided prostate needle biopsy: A prospective multicenter study.

To estimate the prevalence of fluoroquinolone-resistant rectal flora in patients undergoing transrectal ultrasound-guided prostate needle biopsy and to identify the high-risk groups. From January 2015 to March 2016, rectal swabs of 557 men who underwent transrectal ultrasound-guided prostate needle biopsy were obtained from five institutions. Clinical variables, including demographics, rectal swab culture results and infectious complications, were evaluated. Univariable and multivariable analyses were used to identify the risk factors for fluoroquinolone resistance of rectal flora and infectious complications. The incidence of fluoroquinolone-resistant and extended-spectrum beta-lactamase production was 48.1 and 11.8%, respectively. The most common fluoroquinolone-resistant bacteria was Escherichia coli (81% of total fluoroquinolone-resistant bacteria, 39% of total rectal flora), and 16 (2.9%) patients had infectious complications. Univariable and multivariable analysis of clinical parameters affecting fluoroquinolone resistance showed no factor associated with fluoroquinolone resistance of rectal flora. The clinical parameter related to infectious complications after prostate biopsy was a history of operation within 6 months (relative risk 6.60; 95% confidence interval 1.99-21.8, P = 0.002). These findings suggest that a risk-based approach by history taking cannot predict antibiotic resistance of rectal flora, and physicians should consider targeted antibiotic prophylaxis or extended antibiotic prophylaxis for Korean patients undergoing transrectal ultrasound-guided prostate biopsy because of high antibiotic resistance of rectal flora.

Farm level risk factors for fluoroquinolone resistance in E. coli and thermophilic Campylobacter spp. on poultry farms

ABSTRACTData on husbandry practices, performance, disease and drug use were collected during a cross-sectional survey of 89 poultry meat farms in England and Wales to provide information on possible risk factors for the occurrence of fluoroquinolone (FQ)-resistant bacteria. Faeces samples were used to classify farms as “affected” or “not affected” by FQ-resistant (FQr) Escherichia coli or Campylobacter spp. Risk factor analysis identified the use of FQ on the farms as having by far the strongest association, among the factors considered, with the occurrence of FQr bacteria. Resistant E. coli and/or Campylobacter spp. were found on 86% of the farms with a history of FQ use. However, a substantial proportion of farms with no history of FQ use also yielded FQr organisms, suggesting that resistant bacteria may transfer between farms. Further analysis suggested that for Campylobacter spp., on-farm hygiene, cleaning and disinfection between batches of birds and wildlife control were of most significance. By contrast, for E. coli biosecurity from external contamination was of particular importance, although the modelling indicated that other factors were likely to be involved. Detailed studies on a small number of sites showed that FQr E. coli can survive routine cleaning and disinfection. It appears difficult to avoid the occurrence of resistant bacteria when FQ are used on a farm, but the present findings provide evidence to support recommendations to reduce the substantial risk of the incidental acquisition of such resistance by farms where FQ are not used.

Risk factors for fluoroquinolone resistance in ocular cultures.

PurposeTo identify the risk factors associated with fluoroquinolone resistance in patients undergoing cataract surgery.MethodsA total of 1,125 patients (1,125 eyes) who underwent cataract surgery at Veterans Health Service Medical Center from May 2011 to July 2012 were enrolled in this study. Conjunctival cultures were obtained from the patients on the day of surgery before instillation of any ophthalmic solutions. The medical records of patients with positive coagulase negative staphylococcus (CNS) and Staphylococcus aureus (S. aureus) cultures were reviewed to determine factors associated with fluoroquinolone resistance.ResultsOf 734 CNS and S. aureus cultures, 175 (23.8%) were resistant to ciprofloxacin, levofloxacin, gatifloxacin, or moxifloxacin. Use of fluoroquinolone within 3 months and within 1 year before surgery, topical antibiotic use other than fluoroquinolone, systemic antibiotic use, recent hospitalization, ocular surgery, intravitreal injection and use of eyedrops containing benzalkonium chloride were significantly more frequent in resistant isolates than in susceptible isolates. In multivariable logistic regression analysis, ocular surgery (odds ratio [OR], 8.457), recent hospitalization (OR, 6.646) and use of fluoroquinolone within 3 months before surgery (OR, 4.918) were significant predictors of fluoroquinolone resistance, along with intravitreal injection (OR, 2.976), systemic antibiotic use (OR, 2.665), use of eyedrops containing benzalkonium chloride (OR, 2.323), use of fluoroquinolone within 1 year before surgery (OR, 1.943) and topical antibiotic use other than fluoroquinolone (OR, 1.673).ConclusionsRecent topical fluoroquinolone use, hospitalization and ocular surgery were significantly associated with fluoroquinolone resistance in CNS and S. aureus isolates from ocular culture.

2065 WHO SHOULD RECEIVE ALTERNATIVE PROPHYLACTIC REGIMENS FOR PROSTATE BIOPSY? A COMPREHENSIVE LOOK AT RISK FACTORS FOR INFECTION AFTER BIOPSY

INTRODUCTION AND OBJECTIVES: Hospital admission rates for infection secondary to fluoroquinolone (FQ) resistant E. coli following TRUS-guided prostate biopsy have dramatically increased in the last decade. We describe a retrospective case series designed to characterize risk factors for infection and FQ resistance. METHODS: We retrospectively evaluated the medical records of 492 patients who underwent TRUS guided prostate biopsy between 2009 and 2011. Patients’ charts were evaluated for risk factors and complications. Infection was the primary outcome and FQ resistance was the secondary outcome. The following covariates were tested for each outcome: age, race, diabetes mellitus, immunosuppression, catheterization, prostate volume, PSA level, number of biopsy cores obtained, history of prior prostate biopsy, number of past biopsies, active surveillance status, history of UTI, prostatitis, epididymitis, or sepsis, antibiotic use in the past four weeks, use of peri-operative antibiotics, and prior FQ use. Analyses were performed using STATA 12.0 (Stata Corporation, College Station, TX.) RESULTS: Of 492 patients evaluated, 5.69% developed infections. 81.3% of patients with positive cultures were infected with E. coli and 92.3% of these were FQ resistant. All patients except two received four days of ciprofloxacin prophylaxis. 4.6% of patients received additional intra-operative antibiotics. Additional antibiotics were not associated with decreased risk of infection (p .638). In our analysis, prostate volume (p .028), presence of an indwelling catheter (p .008), African American race (p .032), Asian ethnicity (p .021) and history of catheterization (p .008) were significantly associated with infection after biopsy. Active surveillance (AS) was not associated with infection (p .301) nor was history of FQ use (p .889). Most notably, prior FQ use was not a risk factor for FQ resistance (p .653), despite the fact that over 50% of the population had prior FQ use. CONCLUSIONS: Prior FQ use is not associated with infection or FQ resistance indicating that FQ resistance must be acquired by another mechanism. The subgroup who received FQ plus additional antibiotics did not show a decrease in infection rate as compared to those who received FQ monotherapy implying that targeting high risk patients may be ineffective.

913 THE MECHANISMS AND RISK FACTORS FOR FLUOROQUINOLONE-RESISTANCE IN ENTEROCOCCUS FAECALIS STRAINS CLINICALLY ISOLATED FROM URINARY TRACT INFECTION PATIENTS

You have accessJournal of UrologyInfections/Inflammation of the Genitourinary Tract: Kidney & Bladder1 Apr 2012913 THE MECHANISMS AND RISK FACTORS FOR FLUOROQUINOLONE-RESISTANCE IN ENTEROCOCCUS FAECALIS STRAINS CLINICALLY ISOLATED FROM URINARY TRACT INFECTION PATIENTS Tomihiko Yasufuku, Katsumi Shigemura, Minori Matsumoto, Yuzo Nakano, Toshiro Shirakawa, Kazushi Yanaka, Masato Kawabata, Soichi Arakawa, and Masato Fujisawa Tomihiko YasufukuTomihiko Yasufuku Kobe, Japan More articles by this author , Katsumi ShigemuraKatsumi Shigemura Kobe, Japan More articles by this author , Minori MatsumotoMinori Matsumoto Kobe, Japan More articles by this author , Yuzo NakanoYuzo Nakano Kobe, Japan More articles by this author , Toshiro ShirakawaToshiro Shirakawa Kobe, Japan More articles by this author , Kazushi YanakaKazushi Yanaka Kobe, Japan More articles by this author , Masato KawabataMasato Kawabata Kobe, Japan More articles by this author , Soichi ArakawaSoichi Arakawa Kobe, Japan More articles by this author , and Masato FujisawaMasato Fujisawa Kobe, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1009AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Enterococcus faecalis (E. faecalis) isolated from urinary tract infection (UTI) patients often demonstrates antibiotic resistance. The emergence of fluoroquinolone resistant strains have become problem even though fluoroquinolones were frequently used to treat UTI patients. The objective of this study is to investigate the mechanism and risk factors for fluoroquinolone resistance in E. faecalis causing UTI. METHODS We examined the minimum inhibitory concentration (MIC) in levofloxacin (LVFX) and amino acid mutations by direct DNA sequence in 100 clinical isolates of E. faecalis isolated from UTI patients. We set risk factors for LVFX resistance such as age, sex, the number of significant amino acid mutations, and the previous use of fluoroquinolone. The correlation of risk factors with LVFX resistance and with the presence of amino acid mutations was investigated. RESULTS We demonstrated 4 mutations (Ser83-to-Ile and Glu87-to-Lys in gyrA and Ser80-to-Ile and Glu84-to-Val in parC) in the quinolone resistance determining regions (QRDR) in E. faecalis strains clinically isolated from UTI patients. Among all isolates tested, 18 (18.0%) isolates had amino acid mutations and 14 (14.0%) isolates were resistant to LVFX. All LVFX-resistant isolates had amino acid mutations in the QRDR and the isolates which had more than 2 mutations significantly related to LVFX resistance. We revealed that the previous use of fluoroquinolones was significantly related to LVFX resistance (p = 0.015) and the presence of amino acid mutations (p = 0.040) by multivariate analyses. We had 77 isolates from complicated UTI and 23 isolates from uncomplicated UTI from the classificationn of the presence of urinary tract underlying diseases. Sixteen isolates from complicated UTI (20.8%) had amino acid mutations and 2 isolates (16.9%) were resistant to LVFX. On the other hand, 2 isolates from uncomplicated UTI (8.70%) had amino acid mutations and only one isolate (4.3%) was resistant to LVFX. The previous use of fluoroquinolones and other types of antibiotics were significantly associated with LVFX resistance in complicated UTI cases. CONCLUSIONS We demonstrated that amino acid mutations in the QRDR related to fluoroquinolone resistance in E. faecalis and found that there was a significant correlation between the number of amino acid mutations and LVFX resistance. We also revealed that the previous use of fluoroquinolones related to not only LVFX resistance but the presence of amino acid mutations in the QRDR. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e372 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Tomihiko Yasufuku Kobe, Japan More articles by this author Katsumi Shigemura Kobe, Japan More articles by this author Minori Matsumoto Kobe, Japan More articles by this author Yuzo Nakano Kobe, Japan More articles by this author Toshiro Shirakawa Kobe, Japan More articles by this author Kazushi Yanaka Kobe, Japan More articles by this author Masato Kawabata Kobe, Japan More articles by this author Soichi Arakawa Kobe, Japan More articles by this author Masato Fujisawa Kobe, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Mechanisms of and Risk Factors for Fluoroquinolone Resistance in Clinical Enterococcus faecalis Isolates from Patients with Urinary Tract Infections

We examined Enterococcus faecalis strains clinically isolated from 100 patients with urinary tract infections (UTIs) for their susceptibility to levofloxacin (LVX) by measuring the MIC and investigated amino acid mutations by direct DNA sequencing, which were then correlated with LVX resistance. Next, we studied risk factors for LVX resistance, such as age, gender, and previous fluoroquinolone use, and investigated the statistical correlation of these risk factors with each amino acid mutation and LVX resistance. Of the 100 isolates tested, 14 isolates showed LVX resistance and all of these isolates had amino acid mutations. We demonstrated that 2 out of 4 mutations (Ser83-to-Ile in gyrA and Ser80-to-Ile in parC) had a significant correlation with LVX resistance. There was a significant relationship between isolates with 2 or 3 amino acid mutations and LVX resistance. In addition, we found a significant correlation between the previous use of fluoroquinolones and LVX resistance or the presence of mutations and also demonstrated that previous use of other types of antibiotics was significantly related to the presence of mutations by multivariate analysis. In conclusion, we found significant correlation between amino acid mutations in E. faecalis, LVX resistance, and risk factors such as previous use of fluoroquinolones.

Risk factors for fluoroquinolone-resistant Escherichia coli in adults with community-onset febrile urinary tract infection

To assess risk factors for fluoroquinolone resistance in community-onset febrile Escherichia coli urinary tract infection (UTI). A nested case-control study within a cohort of consecutive adults with febrile UTI presenting at primary healthcare centres or emergency departments during January 2004 through December 2009. Resistance was defined using EUCAST criteria (ciprofloxacin MIC >1.0 mg/L). Cases were subjects with fluoroquinolone-resistant E. coli, and controls those with fluoroquinolone-susceptible isolates. Multivariable logistic regression analysis was used to identify potential risk factors for fluoroquinolone resistance. Of 787 consecutive patients, 420 had E. coli-positive urine cultures. Of these, 51 (12%) were fluoroquinolone resistant. Independent risk factors for fluoroquinolone resistance were urinary catheter [odds ratio (OR) 3.1; 95% confidence interval (CI) 0.9-11.6], recent hospitalization (OR 2.0; 95% CI 1.0-4.3) and fluoroquinolone use in the past 6 months (OR 17.5; 95% CI 6.0-50.7). Environmental factors (e.g. contact with animals or hospitalized household members) were not associated with fluoroquinolone resistance. Of fluoroquinolone-resistant strains, 33% were resistant to amoxicillin/clavulanate and 65% to trimethoprim/sulfamethoxazole; 14% were extended-spectrum β-lactamase (ESBL) positive compared with <1% of fluoroquinolone-susceptible isolates. Recent hospitalization, urinary catheter and fluoroquinolone use in the past 6 months were independent risk factors for fluoroquinolone resistance in community-onset febrile E. coli UTI. Contact with animals or hospitalized household members was not associated with fluoroquinolone resistance. Fluoroquinolone resistance may be a marker of broader resistance, including ESBL positivity.

Risk factors and mechanisms of fluoroquinolone resistance in 156 Escherichia coli strains clinically isolated from urinary tract infections

As fluoroquinolone-resistant strains of Escherichia coli emerge, several risk factors for fluoroquinolone resistance have become evident, such as amino acid mutations in the quinolone resistance determining regions (QRDR) of gyrA and parC and previous use of fluoroquinolone. This study investigated risk factors for fluoroquinolone resistance and amino acid mutation in the QRDR in E. coli. We investigated the statistical correlation between each amino acid mutation and resistance to levofloxacin. We examined the minimum inhibitory concentration (MIC) of levofloxacin and the amino acid mutations of gyrA and parC by direct DNA sequence in E. coli clinically isolated from urinary tract infection (UTI) patients. We investigated risk factors for levofloxacin resistance, such as age, sex, and previous use of fluoroquinolone. We found a significant correlation between the number of mutations and resistance to levofloxacin (p < 0.001) and between the presence of underlying urinary tract disease and the presence of mutations (p = 0.004) by multivariate analyses. Three mutations in QRDR were demonstrated to be significantly correlated with levofloxacin resistance. In conclusion, these findings contribute to our understanding of the molecular mechanisms and risk factors for fluoroquinolone resistance.

Risk factors for fluoroquinolone resistance in Enterococcus urinary tract infections in hospitalized patients

Past studies exploring risk factors for fluoroquinolone (FQ) resistance in urinary tract infections (UTIs) focused only on UTIs caused by Gram-negative pathogens. The epidemiology of FQ resistance in enterococcal UTIs has not been studied. We conducted a case-control study at two medical centres within the University of Pennsylvania Health System in order to identify risk factors for FQ resistance in enterococcal UTIs. Subjects with positive urine cultures for enterococci and meeting CDC criteria for healthcare-acquired UTI were eligible. Cases were subjects with FQ-resistant enterococcal UTI. Controls were subjects with FQ-susceptible enterococcal UTI and were frequency matched to cases by month of isolation. A total of 136 cases and 139 controls were included from 1 January 2003 to 31 March 2005. Independent risk factors [adjusted OR (95% CI)] for FQ resistance included cardiovascular diseases [2·24 (1·05-4·79), P=0·037], hospitalization within the past 2 weeks [2·08 (1·05-4·11), P=0·035], hospitalization on a medicine service [2·15 (1·08-4·30), P<0·030], recent exposure to β-lactamase inhibitors (BLIs) [14·98 (2·92-76·99), P<0·001], extended spectrum cephalosporins [9·82 (3·37-28·60), P<0·001], FQs [5·36 (2·20-13·05), P<0·001] and clindamycin [13·90 (1·21-10·49), P=0·035]. Use of BLIs, extended spectrum cephalosporins, FQs and clindamycin was associated with FQ resistance in enterococcal uropathogens. Efforts to curb FQ resistance should focus on optimizing use of these agents.

Risk factors for fluoroquinolone resistance in Gram-negative bacilli causing healthcare-acquired urinary tract infections

The prevalence of urinary tract infections caused by fluoroquinolone-resistant Gram-negative bacilli (FQ-resistant GNB-UTIs) has been increasing. Previous studies that explored risk factors for FQ resistance have focused only on UTIs caused by Escherichia coli and/or failed to distinguish colonisation from infection. We conducted a case-control study at two medical centres within the University of Pennsylvania Health System to identify risk factors for FQ resistance among healthcare-acquired GNB-UTIs. Subjects with positive urine cultures for GNB and who met Centers for Disease Control and Prevention criteria for healthcare-acquired UTI were eligible. Cases were subjects with FQ-resistant GNB-UTI and controls were subjects with FQ-susceptible GNB-UTI matched to cases by month of isolation and species of infecting organism. In total, 251 cases and 263 controls were included from 1 January 2003 to 31 March 2005. Independent risk factors (adjusted odds ratio; 95% confidence interval) for FQ resistance included male sex (2.03; 1.21-3.39; P=0.007), African-American race (1.80; 1.10-2.94; P=0.020), chronic respiratory disease (2.58; 1.18-5.62; P=0.017), residence in a long term care facility (4.41; 1.79-10.88; P=0.001), hospitalisation within the past two weeks (2.19; 1.31-3.64; P=0.003), hospitalisation under a medical service (2.72; 1.63-4.54; P<0.001), recent FQ exposure (15.73; 6.15-40.26; P<0.001), recent cotrimoxazole exposure (2.49; 1.07-5.79; P=0.033), and recent metronidazole exposure (2.89; 1.48-5.65; P=0.002).

Farm-level risk factors for fluoroquinolone resistance inE. coliand thermophilicCampylobacterspp. on finisher pig farms

Logistic regression, supported by other statistical analyses was used to explore the possible association of risk factors with the fluoroquinolone (FQ)-resistance status of 108 pig finisher farms in Great Britain. The farms were classified as 'affected' or 'not affected' by FQ-resistant E. coli or Campylobacter spp. on the basis of isolation of organisms from faecal samples on media containing 1 mg/l FQ. The use of FQ was the most important factor associated with finding resistant E. coli and/or Campylobacter, which were found on 79% (FQ-resistant E. coli) and 86% (FQ-resistant Campylobacter) of farms with a history of FQ use. However, resistant bacteria were also found on 19% (FQ-resistant E. coli) and 54% (FQ-resistant Campylobacter) of farms with no history of FQ use. For FQ-resistant E. coli, biosecurity measures may be protective and there was strong seasonal variation, with more farms found affected when sampled in the summer. For FQ-resistant Campylobacter, the buying-in of grower stock may increase risk and good on-farm hygiene may be protective. The findings suggest that resistant organisms, particularly Campylobacter, may spread between pig farms.

Risk Factors for Coexistence of Fluoroquinolone Resistance and ESBL Production among Enterobacteriaceae in a Greek University Hospital

The purpose of this study was to identify risk factors for fluoroquinolone resist-ance (QR) among ESBL-producing Enterobacteriaceae causing nosocomial infections. The study was conducted in Laikon General Hospital in Athens, Greece, during the period January 2004 - January 2005. Epidemiological and clinical data were collected from the medical charts of the patients diagnosed with nosocomial infections due to an ESBL-producing Enterobacteriaceae.QR was 60% among the 84 ESBL-producing Enterobacteriaceae isolates. Infection from QR-ESBL bacteria was associated with increased hospital stay (p=0.028); QR-ESBL bacteria were isolated later during hospitalization than fluoroquinolone suscep-tible (QS)-ESBL (p=0.089); factors associated with QR were immune-deficiency (p=0.047), previous use of carbapenems (p=0.08) and fluoroquinolones (p=0.067), and admission to the Transplantation Unit (p=0.047). In addition, QR-ESBL bacteria were more likely to be resistant to co-trimoxazole (p<0.001), gentamicin (p=0.054) and tobramycin (p=0.004). Logistic regression analysis indicated that admission to the transplantation unit was an independent risk factor for infection due to a QR-ESBL isolate.Results of this study question ciprofloxacin's usefulness as a valid alternative to carbapenems in our hospital for the treatment of infections due to ESBL-producing bacteria. In addition strategies for addressing the QR-ESBL situation should focus on limiting fluoroquinolone and carbapenem consumption and emphasize on barrier precautions in patients with longer hospitalization, immunosuppression, or admission to the transplantation unit.

Recent changes in bacterial epidemiology and the emergence of fluoroquinolone-resistant Escherichia coli among patients with haematological malignancies: results of a prospective study on 823 patients at a single institution

Regular monitoring of bacterial epidemiology allows evaluation of antibacterial strategies adopted. The aim of this study was to disclose evolving trends in the epidemiology of infections and emerging antibiotic resistance in unselected inpatients with haematological cancers. Febrile/infectious episodes occurring in 823 patients consecutively admitted to a single institution during a 16 month period were analysed. Levofloxacin prophylaxis was used in patients with >7 days expected neutropenia. Fever developed in 364 patients (44.2%) and an infection was documented in 187 (22.7%), either clinically (6.1%) or microbiologically (16.6%). Levofloxacin prophylaxis, used in 39.4% of cases, caused a reduction in febrile episodes only among neutropenic patients and no difference in the frequency of documented infections. Among 164 pathogens isolated, gram-negative (49.4%) outweighed gram-positive bacteria (40.9%), Escherichia coli being most frequent (23.2%). Fluoroquinolone resistance and methicillin resistance were the most frequent types of antibiotic resistance, occurring in 56.1% of bacterial isolates and in 66.7% of staphylococci, respectively. Fluoroquinolone-resistant E. coli accounted for 20.1% of all isolates and for 86.8% of E. coli. Multivariate analysis of risk factors for fluoroquinolone resistance identified prophylaxis (P < 0.001) and neutropenia >7 days (P = 0.02) as independent. Methicillin resistance was independently associated with prophylaxis (P = 0.041) and central venous catheters (P = 0.036). Infections by fluoroquinolone-resistant strains did not show a worse outcome. A shift towards gram-negative bacteria has been occurring in recent years in the bacterial epidemiology of haematological patients. Fluoroquinolone resistance is emerging as a major type of antibacterial resistance, particularly among E. coli strains. Further investigation is needed to explore the consequences of such epidemiological changes.

Empiric Treatment of Uncomplicated Urinary Tract Infection with Fluoroquinolones in Older Women in Israel: Another Lost Treatment Option?

Current guidelines for the treatment of uncomplicated urinary tract infection (UTI) in women recommend empiric therapy with antibiotics for which local resistance rates do not exceed 10-20%. We hypothesized that resistance rates of Escherichia coli to fluoroquinolones may have surpassed this level in older women in the Israeli community setting. To identify age groups of women in which fluoroquinolones may no longer be appropriate for empiric treatment of UTI. Resistance rates for ofloxacin were calculated for all cases of uncomplicated UTI diagnosed during the first 5 months of 2005 in a managed care organization (MCO) in Israel, in community-dwelling women aged 41-75 years. The women were without risk factors for fluoroquinolone resistance. Uncomplicated UTI was diagnosed with a urine culture positive for E. coli. The data set was stratified for age, using 5 year intervals, and stratum-specific resistance rates (% and 95% CI) were calculated. These data were analyzed to identify age groups in which resistance rates have surpassed 10%. The data from 1291 urine cultures were included. The crude resistance rate to ofloxacin was 8.7% (95% CI 7.4 to 10.2). Resistance was lowest among the youngest (aged 41-50 y) women (3.2%; 95% CI 1.11 to 5.18), approached 10% in women aged 51-55 years (7.1%; 95% CI 3.4 to 10.9), and reached 19.86% (95% CI 13.2 to 26.5) among the oldest women (aged 56-75 y). Physicians who opt to treat UTI in postmenopausal women empirically should consider prescribing drugs other than fluoroquinolones. Concomitant longitudinal surveillance of both antibiotic utilization patterns and uropathogen resistance rates should become routine practice in this managed-care organization.

Fluoroquinolone-resistant Pseudomonas aeruginosa: risk factors for acquisition and impact on outcomes

Resistance among Pseudomonas aeruginosa has risen dramatically and parallels the increase in fluoroquinolone (FQ) prescribing in recent years. Risk factors for FQ resistance in P. aeruginosa and its impact on outcomes need to be well characterized. A case-control study was carried out on hospitalized adult patients from whom FQ-resistant (case) and FQ-susceptible (control) P. aeruginosa were isolated. A total of 177 patients with positive cultures (91 cases and 86 controls) and 119 with documented infections (65 cases, 54 controls) were included in risk factor and outcomes analysis, respectively. Independent risk factors for FQ resistance were: FQ exposure (OR 12.6, CI 4.95-32), nosocomial acquisition (OR 8.6, CI 3.5-20.7), and diabetes mellitus (OR 6.4, CI 2.1-19.3). An FQ agent was prescribed in 59% of patients receiving an 'antipseudomonal' empirical regimen. Compared with controls, FQ-resistant cases had a median delay to receiving effective therapy of 3.5 days versus 1 day and poorer outcomes: (i) lower complete response rate (45% versus 63%, P=0.04); (ii) longer time to achieve clinical stability (8 days versus 3 days, P=0.005); and (iii) higher infection-related mortality (21% versus 7%; OR = 2.9, 0.9-9.4). Empirical FQ use (OR 4.6, CI 1.5-14.3), FQ resistance (OR 3.6, CI 1.0-13.1), and high APACHE II score (OR 1.1, CI 1.0-1.2) were independent risk factors for increased mortality. FQ exposure from widespread prescribing is a modifiable risk factor for FQ resistance in P. aeruginosa. FQ empirical therapy for Pseudomonas infections may be associated with significant delays in administering effective therapy resulting in adverse outcomes.

Risk factors for fluoroquinolone resistance in nosocomial Escherichia coli and Klebsiella pneumoniae infections.

The incidence of fluoroquinolone (FQ) resistance has increased markedly in recent years. Even in the common nosocomial pathogens Escherichia coli and Klebsiella pneumoniae, in which the emergence of FQ resistance was believed to be unlikely, increasing resistance to these agents has been noted. Risk factors for FQ resistance in these pathogens remain unknown. Although FQs are important components of the present antimicrobial arsenal, their continued usefulness is threatened by rising FQ resistance. To identify risk factors for nosocomial FQ resistance. A case-control study of hospitalized patients with infections due to FQ-resistant and FQ-susceptible E coli and K pneumoniae occurring between January 1, 1998, and June 30, 1999. We included 123 patients with nosocomial FQ-resistant infections and 70 randomly selected patients with nosocomial FQ-susceptible infections. Independent risk factors (adjusted odds ratio [95% confidence interval]) for FQ resistance were (1) recent FQ use (5.25 [1.81-15.26]); (2) residence in a long-term care facility (3.65 [1.64-8.15]); (3) recent aminoglycoside use (8.86 [1.71-45.99]); and (4) older age (1.03 [1.01-1.06]). Recent FQ use, residence in a long-term care facility, recent aminoglycoside use, and older age were all noted to be independent risk factors for FQ resistance among patients with nosocomial E coli and K pneumoniae infections. Efforts should be directed at recognition and modification of these risk factors to curb the rise in FQ resistance and preserve the utility of these agents in the treatment of common nosocomial gram-negative infections.

Epidemiological investigation of fluoroquinolone resistance in infections due to extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae.

The incidence of infections due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EK) has increased markedly in recent years. Treatment is difficult because of frequent multidrug resistance. Although fluoroquinolones offer effective therapy for ESBL-EK infections, their usefulness is threatened by increasing fluoroquinolone resistance. To identify risk factors for fluoroquinolone resistance in ESBL-EK infections, a case-control study of all patients with ESBL-EK infections from 1 June 1997 through 30 September 1998 was conducted. Of 77 ESBL-EK infections, 43 (55.8%) were resistant to fluoroquinolones. Independent risk factors for fluoroquinolone resistance were fluoroquinolone use (odds ratio [OR], 11.20; 95% confidence interval [CI], 1.99-63.19), aminoglycoside use (OR, 5.83; 95% CI, 1.12-30.43), and long-term care facility residence (OR, 3.39; 95% CI, 1.06-10.83). The genotypes of fluoroquinolone-resistant ESBL-EK isolates were closely related. Efforts should be directed at modification of these risk factors to preserve the utility of fluoroquinolones in the treatment of ESBL-EK infections.