Antimicrobial susceptibility of global inpatient urinary tract isolates of Escherichia coli: results from the Study for Monitoring Antimicrobial Resistance Trends (SMART) program: 2009-2010

Machine learning model for predicting ciprofloxacin resistance and presence of ESBL in patients with UTI in the ED

Increasing antimicrobial resistance in uropathogens is a clinical challenge to emergency physicians as antibiotics should be selected before an infecting pathogen or its antibiotic resistance profile is confirmed. We created a predictive model for antibiotic resistance of uropathogens, using machine learning (ML) algorithms. This single-center retrospective study evaluated patients diagnosed with urinary tract infection (UTI) in the emergency department (ED) between January 2020 and June 2021. Thirty-nine variables were used to train the model to predict resistance to ciprofloxacin and the presence of urinary pathogens' extended-spectrum beta-lactamases. The model was built with Gradient-Boosted Decision Tree (GBDT) with performance evaluation. Also, we visualized feature importance using SHapely Additive exPlanations. After two-step customization of threshold adjustment and feature selection, the final model was compared with that of the original prescribers in the emergency department (ED) according to the ineffectiveness of the antibiotic selected. The probability of using ineffective antibiotics in the ED was significantly lowered by 20% in our GBDT model through customization of the decision threshold. Moreover, we could narrow the number of predictors down to twenty and five variables with high importance while maintaining similar model performance. An ML model is potentially useful for predicting antibiotic resistance improving the effectiveness of empirical antimicrobial treatment in patients with UTI in the ED. The model could be a point-of-care decision support tool to guide clinicians toward individualized antibiotic prescriptions.

Specific capture of Pseudomonas aeruginosa for rapid detection of antimicrobial resistance in urinary tract infections

Urinary tract infections (UTIs) are among the most predominant microbial diseases, leading to substantial healthcare burdens and threatening human well-being. UTIs can become more critical when caused by Pseudomonas aeruginosa, particularly by antimicrobial-resistant types. Thereby a rapid diagnosis and identification of the antimicrobial-resistant P. aeruginosa can support and guide an efficient medication and an effective treatment toward UTIs. Herein, we designed a platform for prompt purification, and effective identification of P. aeruginosa to combat the notorious P. aeruginosa associated UTIs. A peptide (QRKLAAKLT), specifically binding to P. aeruginosa, was grafted onto PEGylated magnetic nanoclusters and enabled a successful capture and enrichment of P. aeruginosa from artificial human urine. Rapid identification of antimicrobial resistance of the enriched P. aeruginosa can be moreover accomplished within 30 min. These functionalized magnetic nanoclusters demonstrate a prominent diagnostic potential to combat P. aeruginosa associated UTIs, which can be extended to other P. aeruginosa involved infections.

Short- and long-term mortality in patients with urosepsis caused by Escherichia coli susceptible and resistant to 3rd generation cephalosporins

Background

The aim of this study was to compare short- and long-term mortality among patients with urosepsis caused by Escherichia coli susceptibile (EC-SC) and resistant (EC-RC) to 3rd generation cephalosporins.

Methods

A retrospective cohort study that included all patients with E. coli urosepsis admitted to a 700-bed hospital from January 2014 until December 2019. Mortality up to 30 days, 6 months and 1 year was assessed using logistic multivariate regression analysis and Cox regression analysis.

Results

A total of 313 adult were included, 195 with EC-SC and 118 patients with EC-RC. 205 were females (74%), mean age was 79 (SD 12) years. Mean Charlson score was 4.93 (SD 2.18) in the EC-SC group and 5.74 (SD 1.92) in the EC-RC group. Appropriate empiric antibiotic therapy was initiated in 245 (78.3%) patients, 100% in the EC-SC group but only 42.5% in the EC-RC group. 30-day mortality occurred in 12 (6.3%) of EC-SC group and 15 (12.7%) in the EC-RC group. Factors independently associated with 30-day mortality were Charlson score, Pitt bacteremia score, fever upon admission and infection with a EC-RC. Appropriate antibiotic therapy was not independently associated with 30-day mortality. Differences in mortality between groups remained significant one year after the infection and were significantly associated with the Charlson co-morbidity score.

Conclusions

Mortality in patients with urosepsis due to E. coli is highly affected by age and comorbidities. Although mortality was higher in the EC-RC group, we could not demonstrate an association with inappropriate empirical antibiotic treatment. Mortality remained higher at 6 months and 1 year long after the infection resolved but was associated mainly with co-morbidity.

Epidemiology of urinary tract infection in adults caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae - a case-control study from Qatar

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Urinary tract infection (UTI) caused by extended-spectrum beta-lactamase (ESBL)-producing organisms is a serious concern in the adult population.

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Escherichia coli is the primary organism causing ESBL-UTI.

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Avoiding indiscriminate use of antibiotics may reduce the incidence of ESBL-UTI.

Background

Community-acquired urinary tract infection (UTI) is the most common infection caused by extended-spectrum beta-lactamase (ESBL)-producing organisms.

Aim

to estimate the prevalence of ESBL-UTI in adults and to identify potential risk factors that may predispose to ESBL-UTI.

Methods

A retrospective study involving adult patients with UTI caused by ESBL-producing organisms was undertaken. Patients with UTI caused by non-ESBL-producing organisms represented the control group.

Results

In total, 1100 UTI isolates were included in the study, 277 of which were ESBL positive. The prevalence rate was 25.2%. The mean age of patients was 55.87 years. On univariate analysis, prior history of UTI or ESBL-UTI, invasive urological procedure within preceding 3 months, hospital admission within preceding 3 months, and exposure to antibiotics were found to be significant risk factors for ESBL-UTI. On multi-variate analysis, use of cephalosporins [adjusted odds ratio (OR) 1.61, P=0.048], previous ESBL-UTI (adjusted OR 2.67, P<0.001), and invasive urological procedure in the preceding year (adjusted OR 1.61, P=0.022) were found to be independent risk factors for ESBL-UTI.

Conclusions

In Qatar, the prevalence of ESBL-UTI in adults is modest. Recent exposure to antibiotics, previous ESBL-UTI and invasive urological procedures were found to be independent risk factors for ESBL-UTI.

Prevalence and Impact of Biofilms on Bloodstream and Urinary Tract Infections: A Systematic Review and Meta-Analysis

This study sought to assess the prevalence and impact of biofilms on two commonly biofilm-related infections, bloodstream and urinary tract infections (BSI and UTI). Separated systematic reviews and meta-analyses of observational studies were carried out in PubMed and Web of Sciences databases from January 2005 to May 2020, following PRISMA protocols. Studies were selected according to specific and defined inclusion/exclusion criteria. The obtained outcomes were grouped into biofilm production (BFP) prevalence, BFP in resistant vs. susceptible strains, persistent vs. non-persistent BSI, survivor vs. non-survivor patients with BSI, and catheter-associated UTI (CAUTI) vs. non-CAUTI. Single-arm and two-arm analyses were conducted for data analysis. In vitro BFP in BSI was highly related to resistant strains (odds ratio-OR: 2.68; 95% confidence intervals-CI: 1.60–4.47; p < 0.01), especially for methicillin-resistant Staphylococci. BFP was also highly linked to BSI persistence (OR: 2.65; 95% CI: 1.28–5.48; p < 0.01) and even to mortality (OR: 2.05; 95% CI: 1.53–2.74; p < 0.01). Candida spp. was the microorganism group where the highest associations were observed. Biofilms seem to impact Candida BSI independently from clinical differences, including treatment interventions. Regarding UTI, multi-drug resistant and extended-spectrum β-lactamase-producing strains of Escherichia coli, were linked to a great BFP prevalence (OR: 2.92; 95% CI: 1.30–6.54; p < 0.01 and OR: 2.80; 95% CI: 1.33–5.86; p < 0.01). More in vitro BFP was shown in CAUTI compared to non-CAUTI, but with less statistical confidence (OR: 2.61; 95% CI: 0.67–10.17; p < 0.17). This study highlights that biofilms must be recognized as a BSI and UTI resistance factor as well as a BSI virulence factor.

Effectiveness and safety of an institutional aminoglycoside-based regimen as empirical treatment of patients with pyelonephritis

OBJECTIVES

To determine clinical outcomes associated with aminoglycosides versus other antimicrobial agents as empirical treatment of hospitalized patients with pyelonephritis.

PATIENTS AND METHODS

An institutional programme promoting aminoglycosides as empirical treatment of pyelonephritis was implemented in 2016. We reviewed the hospital records of patients with pyelonephritis from January 2017 to April 2019. The primary outcome was death within 30 days of index culture. Initial treatment with aminoglycoside-based regimens was compared with non-aminoglycoside antibiotics. Propensity score matching was performed to adjust for between-group differences in baseline covariates.

RESULTS

The study cohort included 2026 patients, 715 treated with aminoglycosides and 1311 treated with non-aminoglycoside drugs (ceftriaxone, n = 774; piperacillin/tazobactam, n = 179; carbapenems, n = 161; and fluoroquinolones, n = 133); 589 patients (29%) had bloodstream infections. Treatment with aminoglycosides was associated with a higher likelihood of in vitro activity against clinical isolates (OR = 2.0; P < 0.001). Death at 30 days occurred in 55 (7.6%) versus 145 (11%) patients treated with aminoglycosides and non-aminoglycoside drugs, respectively (adjusted HR = 0.78; P = 0.013). Aminoglycosides were either superior or similar to comparator drugs in all patient subgroups, stratified according to age, glomerular filtration rate, bacteraemia, haemodynamic shock and infection with third-generation cephalosporin-resistant Enterobacteriaceae. The incidence of acute kidney injury was similar for aminoglycosides and comparators (2.5% versus 2.9%, respectively; P = 0.6).

CONCLUSIONS

Within the context of an institutional programme, initial empirical treatment of pyelonephritis with aminoglycosides was associated with higher rates of in vitro activity and lower overall mortality compared with non-aminoglycoside drugs, without excess nephrotoxicity.

Antimicrobial Resistance Patterns of Urinary Escherichia coli Among Outpatients in Washington State, 2013-2017: Associations with Age and Sex

BACKGROUND

Management of acute, uncomplicated cystitis in outpatients benefits from knowledge of drug resistance patterns in the population. However, antibiograms are often not available for the outpatient setting, and the role of host factors such as sex and age in assessing the likelihood of resistance are not well understood. We investigated whether antibiotic resistance patterns of outpatient urinary Escherichia coli (EC) isolates vary by age group and sex in a large database of antibiotic susceptibility test (AST) results from Washington State.

METHODS

We retrospectively analyzed AST data for outpatient urinary EC isolates in Washington State tested at a clinical reference laboratory from 2013 - 2017. In logistic regression models stratified by sex, we tested the associations of antibiotic resistance with patient age.

RESULTS

We found females >50 years had greater odds than females younger than 19 for resistance to amoxicillin-clavulanate (odds ratio [OR], 1.43; 95% CI, 1.22-1.69), ciprofloxacin (OR, 3.04; 95% CI, 2.48-3.74), ceftriaxone (OR, 2.58; 95% CI, 1.77-3.92), and gentamicin (OR, 1.62; 95% CI, 1.27-2.08) (all p<0.001). Compared to males younger than 19, males >50 years had greater odds of resistance to ciprofloxacin (OR, 2.59; 95% CI, 1.18-5.69) and lower odds of resistance to amoxicillin-clavulanate (OR, 0.56; 95% CI, 0.34-0.96) (all p<0.05).

CONCLUSION

These findings demonstrate that age and sex are associated with variability in antibiotic resistance patterns in the outpatient setting. Availability of outpatient antibiotic resistance data based on sex and age may be useful to inform empiric prescribing for outpatient UTIs and to support antibiotic stewardship efforts.

Predictive utility of prior positive urine culture of extended- spectrum β -lactamase producing strains

Rising incidence of extended- spectrum beta-lactamase (ESBL) induced urinary tract infections (UTIs) is an increasing concern worldwide. Thus, it is of paramount importance to investigate novel approaches that can facilitate the identification and guide empiric antibiotic therapy in such episodes. The study aimed to evaluate the usability of antecedent ESBL-positive urine culture to predict the pathogenic identity of future ones. Moreover, the study evaluated the accuracy of selected empiric therapy in index episodes. This was a retrospective study that included 693 cases with paired UTI episodes, linked to two separate hospital admissions within 12 month-period, and a conditional previous ESBL positive episode. Pertinent information was obtained by reviewing patients' medical records and computerized laboratory results. Multivariate analysis showed that shorter interval between index and previous episodes was significantly associated with increased chance of ESBL-positive results in current culture (OR = 0.912, 95CI% = 0.863-0.963, p = 0.001). Additionally, cases with ESBL-positive results in current culture were more likely to have underlying urological/surgical condition (OR = 1.416, 95CI% = 1.018-1.969, p = 0.039). Investigations of the accuracy of current empirical therapy revealed that male patients were less accurately treated compared to female patients (OR = 0.528, 95CI% = 0.289-0.963, p = 0.037). Furthermore, surgical patients were treated less accurately compared to those treated in internal ward (OR = 0.451, 95CI% = 0.234-0.870, p = 0.018). Selecting an agent concordant with previous microbiologic data significantly increased the accuracy of ESBL-UTIs therapy (p<0.001). A quick survey of the previous ESBL urine culture results can guide practitioners in the selection of empiric therapy for the pending current culture and thus improve treatment accuracy.

Reactive oxygen species and uspA overexpession: an alternative bacterial response toward selection and maintenance of multidrug resistance in clinical isolates of uropathogenic E. coli

Emergence of multidrug resistance (MDR) in uropathogenic E. coli (UPEC) demands alternative therapeutic interventions. Bactericidal antibiotics at their sub-inhibitory concentration stimulate production of reactive oxygen species (ROS) that results in oxidative stress, generates mutations, and alters transcription of different genes. Sub-inhibitory concentration of antibiotics facilitates selection of highly resistant population. Universal stress protein A (uspA) overexpression in MDR-UPEC at sub-inhibitory bactericidal antibiotics concentration was investigated to explore alternative survival strategy against them. Fifty clinical UPEC isolates were screened. Minimum inhibitory concentration (MIC) against three different bactericidal antibiotics (ciprofloxacin, CIP; ceftazidime, CAZ; gentamycin, GEN) was determined by broth dilution method; ROS production by DCFDA and overexpression of uspA by real-time PCR were determined at the sub-inhibitory concentration of antibiotics. DNA ladder formation and SEM studies were performed with drug untreated and treated samples. Statistical analysis was done by Student's t test and Pearson's correlation analysis; 25 out of 50 UPEC exhibited high MIC against CIP (> 200 μg/ml), CAZ (> 500 μg/ml), GEN (> 500 μg/ml), with varied ROS production (p ≤ 0.001) in treated than untreated controls. DNA ladder formation confirmed ROS production in drug-treated samples. SEM analysis revealed unaltered cell morphology in both untreated and drug-treated bacteria. uspA was universally overexpressed in all 25 UPEC. A significant correlation (p ≤ 0.001) between ROS production and uspA overexpression was observed in 19 out of 25 MDR isolates at sub-inhibitory doses of the bactericidal antibiotics. Therefore, this study highlights an alternative strategy that the MDR isolates may acquire when exposed to sub-inhibitory drug concentration for their survival.

OXA-1 β-lactamase and non-susceptibility to penicillin/β-lactamase inhibitor combinations among ESBL-producing Escherichia coli

Background

ESBL-producing Escherichia coli have expanded globally since the turn of the century and present a major public health issue. Their in vitro susceptibility to penicillin/inhibitor combinations is variable, and clinical use of these combinations against ESBL producers remains controversial. We hypothesized that this variability related to co-production of OXA-1 penicillinase.

Methods

During a national study we collected 293 ESBL-producing E. coli from bacteraemias, determined MICs by BSAC agar dilution, and undertook genomic sequencing with Illumina methodology.

Results

The collection was dominated by ST131 (n = 188 isolates, 64.2%) and blaCTX-M-15 (present in 229 isolates, 78.2%); over half the isolates (159/293, 54.3%) were ST131 with blaCTX-M-15. blaOXA-1 was found in 149 ESBL producers (50.9%) and blaTEM-1/191 in 137 (46.8%). Irrespective of whether all isolates were considered, or ST131 alone, there were strong associations (P < 0.001) between co-carriage of blaOXA-1 and reduced susceptibility to penicillin/inhibitor combinations, whereas there was no significant association with co-carriage of blaTEM-1/191. For piperacillin/tazobactam the modal MIC rose from 2 mg/L in the absence of blaOXA-1 to 8 or 16 mg/L in its presence; for co-amoxiclav the shift was smaller, from 4 or 8 to 16 mg/L, but crossed the breakpoint. blaOXA-1 was strongly associated with co-carriage also of aac(6')-Ib-cr, which compromises amikacin and tobramycin.

Conclusions

Co-carriage of OXA-1, a penicillinase with weak affinity for inhibitors, is a major correlate of resistance to piperacillin/tazobactam and co-amoxiclav in E. coli and is commonly associated with co-carriage of aac(6')-Ib-cr, which narrows aminoglycoside options.

Prevalence of plasmid-mediated resistance genes among multidrug-resistant uropathogens in Egypt

Background

The emergence of multidrug-resistant (MDR) uropathogens has become a public health threat and current knowledge of the genotypic basis of bacterial resistance is essential for selecting appropriate treatment options.

Objectives

To determine the prevalence of antimicrobial resistance among MDR uropathogens and to elucidate the molecular bases of plasmid-mediated resistance.

Methods

Bacterial isolates were recovered from urine specimens of 150 out-patients with signs and symptoms of urinary tract infections (UTIs) at El-Demerdash Hospital, Cairo, Egypt. Standard methods were used for identification, antimicrobial susceptibility testing was performed according to CLSI guidelines.

Results

Among the recovered isolates, 22.7% and 77.3% were Gram-positive, and negative, respectively. Of which; 43.3% were MDR with 60% harboring plasmids. Extended spectrum β-lactamase (ESBL) genes ^blaCTX-M, ^blaSHV, and ^blaTEM were detected on plasmids of 89.7%, 41%, and 84.6% of the tested isolates, respectively. The aminoglycoside resistance gene aac6′-Ib/aac-6′-Ib-cr was found on plasmids of 92.3% of the tested isolates followed by qnrS (92.3%), qnrB (46.2%), and qnrA (7.7%). The most prevalent quinolone efflux pump gene was oqxB (38.5%), followed by oqxA (20.5%), then qepA (10.3%).

Conclusion

High levels of resistance to nitrofurans, β-lactam/β-lactamase inhibitor, cephalosporins, aminoglycosides, and fluoroquinolones were detected, and their use as empirical treatment for UTIs has become questionable.

Increased fluid intake for the prevention of urinary tract infection in adults and children in all settings: a systematic review

BACKGROUND

Non-antibiotic interventions for urinary tract infection (UTI) prevention have been investigated as a strategy to reduce antibiotic prescribing for UTI and subsequent antibiotic resistance. Increased hydration is widely advocated for preventing UTI; however, evidence for its effectiveness is unknown.

AIM

To systematically review the published literature on the effectiveness of increased fluid intake as a preventive intervention for UTI in adults and children in any setting.

METHODS

Five electronic databases were searched from inception to February 2019 to identify published randomized controlled trials (RCTs) and quasi-experimental studies evaluating the effectiveness of high (≥1.5 L/24 h) versus normal/low (<1.5 L/24 h) fluid intake for UTI prevention. The outcome was UTI incidence. Risk of bias was assessed using the Cochrane Collaboration's tool. Due to the small number of studies identified, meta-analysis was not possible. Hence a narrative synthesis was undertaken.

FINDINGS

Of the 2822 potentially relevant papers, two were eligible for inclusion: an RCT (individual randomization) and a cluster-RCT. Both studies differed regarding participants, setting, sample size, UTI definition, and intervention. The RCT was assessed as having a low risk of bias whereas the cluster-RCT had a high risk of bias. Only the RCT, which included healthy premenopausal women visiting primary care clinics, demonstrated statistical significance for the effect of high fluid intake for UTI prevention.

CONCLUSION

The lack of enough adequately powered and robust RCTs highlights the need for further research on the effectiveness of this intervention for UTI prevention.

The prevalence of resistant Gram-negative bacteraemia among hospitalized patients in Tucson, Arizona over a 12-month period; A retrospective single center study

Introduction

The objectives of this retrospective review were to: (a) determine the prevalence of resistant Gram-negative bacteraemia among hospitalized patients; (b) evaluate antibiotic use; (c) determine the time taken for Gram staining to final species identification.

Methods

For this retrospective study, information was extracted from patients’ electronic medical records. Eligible patients had been admitted to a 300-bed tertiary care hospital in Tucson, Arizona from October 2015 to October 2016, were over 18 years of age and had a positive blood culture for Gram-negative bacteraemia.

Results

In total, 84 patients with Gram-negative bacteraemia were identified; urinary tract infection was the most common source of infection (71%). ESBL-producing microorganisms were isolated from five (6%) patients and no MDR pathogens were identified. The, median time to Gram stain was 20.5 hours and the median time to final identification was 54.5 hours. Delayed de-escalation of broad-spectrum antibiotics (i.e., >24 hours after final culture) occurred in 25% patients with a median length of hospital stay of 118 hours (range: 56–552 hours) compared with a median length of hospital stay of 89 hours (range: 5–334 hours) in the early de-escalation group.

Conclusion

The prevalence of bacteraemia due to resistant Gram-negative microorganisms is low (6%) in this institution. However, there may be room for improvement in the antimicrobial stewardship program with regard to rapid diagnostic testing.

Analysis of Risk Factors for Multiantibiotic-Resistant Infections Among Surgical Patients at a Children's Hospital

BACKGROUND

To identify the potential risk factors for multiantibiotic-resistant infections and provide sufficient evidence for multiantibiotic resistance prevention and control.

MATERIALS AND METHODS

We conducted a retrospective study of all patients in pediatric orthopedics, pediatric heart surgery, and pediatric general surgery at a level 3, grade A children's hospital from January to December 2016. The clinical laboratory information monitoring system and the medical record system were used to collect patient information regarding age, surgery type, preoperative length of stay, admission season, incision type, preoperative infection, intraoperative blood loss, postoperative use of invasive equipment, duration of catheter drainage, and timepoint of intraoperative prophylactic antibiotics administration. We used logistic univariate and multivariate regression analysis to analyze the potential risk factors for multiantibiotic-resistant infections among pediatric surgical patients. SPSS 21.0 and Excel software packages were used for the statistical analysis.

RESULTS

In total, 2,973 patients met the inclusion criteria: 1,247 patients in pediatric orthopedics, 1,089 patients in pediatric heart surgery, and 637 patients in pediatric general surgery. At the end of the study, 113 patients were multiantibiotic-resistant infection cases; the rate of multiantibiotic-resistant infections was 3.80%, and the detection rate was 84.79%. Multivariate analysis indicated that the multiantibiotic-resistant infection cases were influenced by age, department, admission season, incision type, preoperative infection, and duration of catheter drainage.

CONCLUSIONS

Age, department, admission season, incision type, preoperative infection, and duration of catheter drainage may provide possible evidence for prevention and control strategies of multiantibiotic-resistant infections.

Recent advances in managing lower urinary tract infections

Urinary tract infections (UTIs) are among the most common bacterial infections. Traditionally, all symptomatic UTIs are tested and treated. The use of antibiotics has resulted in an antibiotic resistance crisis, and we have limited options for managing UTIs. Currently, we live in the era of antimicrobial resistance and may live in other eras like the era of the microbiome. New insights might provide an opportunity to prevent the overuse and misuse of antibiotics and could enable the development of innovate managing strategies.

Community-Acquired Urinary Tract Infection by Escherichia coli in the Era of Antibiotic Resistance

Urinary tract infections (UTIs) caused by Escherichia coli (E. coli) are the most common types of infections in women. The antibiotic resistance of E. coli is increasing rapidly, causing physicians to hesitate when selecting oral antibiotics. In this review, our objective is to ensure that clinicians understand the current seriousness of antibiotic-resistant E. coli, the mechanisms by which resistance is selected for, and methods that can be used to prevent antibiotic resistance.

Urosepsis Due to Extended-Spectrum β-Lactamase-Producing Escherichia coli: A Retrospective, Single-Centre Review of Risk Factors and Clinical Outcomes

BACKGROUND

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are pathogens that are implicated in urosepsis and may be associated with greater morbidity and mortality than non-ESBL Enterobacteriaceae. Identification of risk factors for ESBL infection may facilitate the selection of appropriate empiric therapy.

OBJECTIVES

The primary objectives were to determine the cumulative incidence of ESBL urosepsis, to identify major risk factors for ESBL urosepsis, and to determine the impact of international travel on development of ESBL urosepsis in an ethnically diverse Canadian population. The secondary objective was to characterize the outcomes of patients with ESBL urosepsis.

METHODS

A single-centre retrospective nested case-control study was conducted from January 2011 to June 2013. The study cohort consisted of adult patients with urosepsis and positive results on blood culture for ESBL-producing and non-ESBL-producing Enterobacteriaceae. Multivariate analysis was then used to determine risk factors for ESBL urosepsis.

RESULTS

The cumulative incidence of ESBL urosepsis at the study site was 19.4% (58/299) over 2.5 years. The 58 cases of ESBL urosepsis were compared with 118 controls (patients with urosepsis caused by non-ESBL Enterobacteriaceae). Significant predictors of ESBL urosepsis were chronic renal insufficiency (odds ratio [OR] 4.66, 95% confidence interval [CI] 1.96-11.08; p < 0.001) and travel to an endemic region in the previous 6 months (OR 4.62, 95% CI 1.17-18.19; p = 0.029), as well as Punjabi or Hindi as the primary language (OR 3.25, 95% CI 1.45-7.29; p = 0.004) and male sex (OR 2.65, 95% CI 1.21-5.80; p = 0.015). Patients with ESBL urosepsis had worse prognosis-in terms of death or discharge with palliative measures only-than those with non-ESBL urosepsis (7/58 [12.1%] versus 4/118 [3.4%]; p = 0.042).

CONCLUSIONS

Institution-specific data support prompt recognition of patients at risk for ESBL infections. Chronic renal insufficiency, recent travel to regions endemic for ESBL-producing organisms, primary language of Punjabi or Hindi, and male sex were the strongest risk factors for ESBL urosepsis at the study centre. However, findings from this single-centre study may not be generalizable to other institutions.

Risk factors for Pseudomonas aeruginosa infections in Asia-Pacific and consequences of inappropriate initial antimicrobial therapy: A systematic literature review and meta-analysis

OBJECTIVES

Treating infections of Gram-negative pathogens, in particular Pseudomonas aeruginosa, is a challenge for clinicians in the Asia-Pacific region owing to inherent and acquired antimicrobial resistance. This systematic review and meta-analysis provides updated information on risk factors for P. aeruginosa infection in Asia-Pacific as well as the consequences (e.g. mortality, costs) of initial inappropriate antimicrobial therapy (IIAT).

METHODS

Embase and MEDLINE databases were searched for Asia-Pacific studies reporting the consequences of IIAT versus initial appropriate antimicrobial therapy (IAAT) in Gram-negative bacterial infections as well as risk factors for serious P. aeruginosa infection. A meta-analysis of unadjusted mortality was performed using a random-effects model.

RESULTS

A total of 22 studies reporting mortality and 13 reporting risk factors were identified. The meta-analysis demonstrated that mortality was significantly lower in patients receiving IAAT versus IIAT, with a 67% reduction observed for 28- or 30-day all-cause mortality (odds ratio=0.33, 95% confidence interval 0.20-0.55; P<0.001). Risk factors for serious P. aeruginosa infection include previous exposure to antimicrobials, mechanical ventilation and previous hospitalisation.

CONCLUSION

High rates of antimicrobial resistance in Asia-Pacific as well as the increased mortality associated with IIAT and the presence of risk factors for serious infection highlight the importance of access to newer and appropriate antimicrobials.

Epidemiology and susceptibility of pathogens from SMART 2011-12 Turkey: evaluation of hospital-acquired versus community-acquired urinary tract infections and ICU- versus non-ICU-associated intra-abdominal infections

Objectives

To describe the epidemiology and susceptibility of pathogens (including ESBL producers) from hospital-acquired (HA) versus community-acquired (CA) urinary tract infections (UTIs) and ICU- versus non-ICU-associated intra-abdominal infections (IAIs) in Turkey as a part of the SMART study.

Methods

: For this report, Gram-negative pathogens (363 from UTIs and 458 from IAIs) were collected in 2011 and 2012 at six hospitals in Turkey. HA versus CA UTIs and ICU- versus non-ICU-associated IAIs were compared for the species isolated, percentage of ESBL-positive isolates by species and susceptibility for overall and individual Gram-negative species.

Results

: Escherichia coli was the most common pathogen identified in HA (40.2%) and CA (73.9%) UTIs and ICU-associated (25.8%) and non-ICU-associated (43.3%) IAIs. The rate of ESBL-positive E. coli was significantly higher in HA than in CA UTIs (50.5% versus 38.2%, P  <   0.001) and in non-ICU-associated than in ICU-associated IAIs (52.5% versus 29.2%, P  = 0.029). Of the drugs studied, only amikacin was active against ≥90% of pathogens in UTIs, while ertapenem, imipenem and amikacin were active against ≥90% of E. coli ; and imipenem, amikacin and cefoxitin were active against ≥90% of Klebsiella pneumoniae in IAIs.

Conclusions

Our findings demonstrated that E. coli continues to be the principal pathogen of UTIs and IAIs in Turkey. Along with a high rate of ESBL-positive isolates, high antimicrobial resistance among Gram-negative bacilli from either UTIs or IAIs was noted particularly in the case of HA UTIs and ICU-associated IAIs, with a higher likelihood of carbapenem- or amikacin-based therapy to provide the broadest activity against bacterial pathogens.

Prospective cohort study of risk factors for extended-spectrum ß-lactamase-producing Escherichia coli urinary tract infections in elderly patients admitted to hospital

BACKGROUND

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli are currently common in community-onset infections, limiting therapeutic options. In this work we aim to identify the prevalence of and risk factors for ESBL-producing E. coli in elderly patients with urinary tract infections (UTI) admitted to hospital.

METHODS

Prospective cohort study on elderly patients with E. coli UTI admitted to a university hospital in Spain, from January 2013 to December 2015. Clinical features, microbiology and outcomes were recorded from the electronic medical records and reviewed by two researchers. Cases were segregated according to ESBL-producing E. coli. Risk factors for ESBL-producing E. coli were analysed by multivariate analysis.

RESULTS

The prevalence of ESBL-producing E. coli was 27.4% (85/310). Healthcare-associated UTI was the only risk factor for ESBL-producing E. coli (OR 6.79; 95% CI 3.22-14.31, P < .001) by multivariate analysis. ESBL-producing E. coli was 43.9% in the healthcare-associated UTI group and 8.9% in the community-acquired UTI group (P < .001). Inadequate empirical antibiotic therapy and length of stay in hospital were higher in the ESBL-producing E. coli group than in the non-ESBL-producing E. coli group (62.3% vs 5.3% and 6.60 ± 3.69 days vs 5.61 ± 3.16 days, respectively). Mortality was not significantly different between groups (13% in ESBL-producing E. coli group vs 7.5% in non-ESBL-producing E. coli group, P = .140).

SUMMARY

Healthcare-associated UTI was a risk factor for ESBL-producing E. coli in elderly patients with UTI admitted to hospital. Our results might help clinicians in choosing empirical antibiotics in an overall high rate setting of ESBL-producing E. coli.

Risk factors for extended-spectrum β-lactamase-producing Escherichia coli urinary tract infection in the community in Denmark: a case-control study

OBJECTIVE

To verify the role of proton pump inhibitors (PPI) and nitrofurantoin, which have appeared as novel risk factors for carriage of extended-spectrum β-lactamase (ESBL) -producing Escherichia coli, as risk factors for ESBL E. coli urinary tract infection (UTI). We included known risk factors to ascertain whether our findings are comparable with those of previous studies.

METHODS

Population-based case-control study including 339 cases with community-onset ESBL E. coli UTI in 2007-2012, 3390 non-ESBL E. coli UTI controls and 3390 population controls. We investigated potential risk factors by estimating ORs and 95% CIs adjusting for sex, age and co-morbidity.

RESULTS

Comparing cases with non-ESBL E. coli UTI, PPI use yielded an OR of 1.6 (95% CI 1.2-2.0) and antibiotic exposure gave an OR of 1.4 (95% CI 1.1-1.8); these were driven by nitrofurantoin (OR 1.8; 95% CI 1.3-2.6) and macrolides (OR 1.7; 95% CI 1.2-2.3). Other risk factors included previous hospitalization with one or two and more than two hospitalizations versus none yielding ORs of 1.9 (95% CI 1.4-2.5) and 4.6 (95% CI 3.2-6.8), recent surgery (OR 2.0; 95% CI 1.5-2.8), renal disease (OR 2.2; 95% CI 1.4-3.4), chronic pulmonary disease (OR 1.4; 95% CI 1.0-2.0) and cancer (OR 1.5; 95% CI 1.1-2.1). Comparing cases with population controls, we found that most risk factors were also risk factors for non-ESBL UTI.

CONCLUSIONS

ESBL E. coli UTI were associated with previous hospitalization and surgery. Nitrofurantoin and macrolides augmented the risk. PPIs had a moderate effect but may be important facilitators of ESBL carriage due to their widespread use.

Ceftazidime-avibactam: novel antimicrobial combination for the treatment of complicated urinary tract infections

Ceftazidime-avibactam is a combination of a third-generation cephalosporin and a novel non-beta-lactam beta-lactamase inhibitor. This combination was recently recommended for the treatment of complicated urinary tract infections, including acute pyelonephritis, in adults with limited or no alternative treatment options. The current review is aimed to determine activity, efficacy and safety of ceftazidime-avibactam in the treatment of patients with complicated urinary tract infections.

Efficacy, pharmacokinetic and pharmacodynamic profile of ceftolozane + tazobactam in the treatment of complicated urinary tract infections

INTRODUCTION

Urinary tract infections (UTIs) are the second most common nosocomially acquired infections, responsible for approximately 21% of healthcare-associated pyelonephritis and 10.5% of urosepsis. Worldwide trends of increasing resistance resulted in the urgent need for novel antimicrobials that would be active against bacterial resistance mechanisms as an alternative to carbapenems, which are considered last resort antibiotics.

AREAS COVERED

The current review is based on a Medline search of published English language literature and contains summary information regarding the evaluation of pharmacologic properties, efficacy, safety and activity of ceftolozane+tazobactam against common bacterial resistance mechanisms.

EXPERT OPINION

In vivo and vitro studies demonstrated high activity of ceftolozane+tazobactam in the combination of 2:1 against a variety of uropathogens, including ESBL-producers. Phase II and Phase III studies performed in patients with complicated UTIs showed good tolerability and safety of ceftolozane+tazobactam when prescribed intravenously 1.5 g every 8 h for 7 days and at least non-inferiority to a high dose (750 mg) of levofloxacin. The pharmacokinetics of ceftolozane+tazobactam makes it a worthy alternative to carbapenems in cases of complicated UTIs, also caused by multidrug resistant uropathogens.

Urological infections due to multidrug-resistant bacteria: what we need to know?

PURPOSE

Recent epidemiological data have confirmed the increasing problem of antimicrobial resistance not only for hospitalized, healthcare-associated patients, but also for outpatients. In particular, the progressive increase in resistance to broad-spectrum antibiotics, such as third-generation cephalosporins, fluoroquinolones or carbapenems in Enterobacteriaceae, is an alarming situation for all urologists and general practitioners. Here, we aimed to review the epidemiological data of multidrug-resistant bacteria in the urological setting, in order to summarize all diagnostic and therapeutic recommendations to use in everyday clinical practice.

METHODS

We collected all recent publications from Medline and Cochrane Library from January 2000 to December 2013. Moreover, data from the abstracts presented at the EAU and AUA Congresses during the last 5 years have also been analyzed. All papers were evaluated by an expert panel on urological infections on behalf of the Italian Urological Association (SIU).

RESULTS

Fluoroquinolone and other antibiotic-resistant bacteria prevalence is normally very high in the lower urinary tract infection patients. In particular, multidrug-resistant bacteria prevalence in urological practice contributes to infectious morbidity increasing the financial costs to healthcare system. The expert panel on urological infections on behalf of the Italian Urological Association formulated new diagnostic pathway and therapeutic protocol in patients affected by urological tract infections due to multidrug-resistant bacteria.

CONCLUSIONS

The recent emergence of multidrug-resistant pathogens is an alarming public health issue also in urological practice with socioeconomic importance. Our practice should be revised on the basis of these new acquisitions.

Amikacin therapy for urinary tract infections caused by extended-spectrum β-lactamase-producing Escherichia coli

BACKGROUND/AIMS

The number of urinary tract infections (UTIs) caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) is increasing. In an outpatient setting, there are limited therapeutic options to treat ESBL-producing pathogens. We evaluated the outcomes of amikacin outpatient parenteral antibiotic therapy (OPAT) for UTIs caused by ESBL-EC in patients not pre-treated with carbapenem.

METHODS

We retrospectively evaluated the outcomes of amikacin OPAT for UTIs caused by ESBL-EC.

RESULTS

From November 2011 to October 2012, eight females, who could not be hospitalized for carbapenem treatment, were treated with amikacin OPAT for nine episodes of non-bacteremic ESBL-EC UTIs. Seven of the eight patients had one or more comorbidities. Of the nine UTI cases, three had symptomatic lower UTIs and six had non-bacteremic upper UTIs. In all of the cases, symptomatic and laboratory improvements were observed following amikacin OPAT. One patient showed a delayed relapse with bilateral microabscesses 3 weeks after treatment cessation; however, a clinical and microbiological cure was eventually reached. All of the patients were able to tolerate amikacin OPAT without any significant nephrotoxicity or ototoxicity.

CONCLUSIONS

Amikacin OPAT represents a feasible therapeutic option for non-bacteremic UTIs caused by ESBL-EC in settings with limited resources.

Fosfomycin: An Alternative Therapy for the Treatment of UTI Amidst Escalating Antimicrobial Resistance

INTRODUCTION

Urinary tract infections (UTIs) are the most commonly encountered infectious diseases. The current study was undertaken with a dual purpose, to provide an insight into the current scenario of the microorganisms causing UTI, their antimicrobial sensitivity patterns and also try and evaluate the activity of fosfomycin against E. coli, both ESBL producers as well as non-producers.

MATERIALS AND METHODS

The study was conducted prospectively in the Department of Microbiology of a tertiary care hospital from January to June 2014. A total of 358 isolates from the urinary samples of the patients with a diagnosis of urinary tract infection were included in the study. Antibiotic sensitivity testing and extended spectrum beta lactamase (ESBL) production testing was done as per CLSI guidelines.

RESULTS

These represented 297 (82.9%) gram-negative isolates and 61 (17%) gram-positive isolates. The 297 gram-negative isolates represented 265 (89.2%) members of the Enterobacteriaceae, 185 (69.8%) of which were Escherichia coli, 66 (24.9%) Klebsiella spp. and 14 (5.28%) Proteus spp. Non-fermentative Pseudomonas spp were isolated from 8.9% cases. Amongst the Gram negative isolates tested, 78 (21.8%) formed extended spectrum beta-lactamases. Of the total 358 isolates tested, 338 (94.4%) were found to be susceptible to fosfomycin.

CONCLUSION

Fosfomycin showed good activity against both ESBL-producing and ESBL-negative E. coli isolates. The main finding of our study is that fosfomycin exhibits excellent antimicrobial activity even against the isolates with relatively high levels of antimicrobial resistance and hence can be a useful drug in our armamentarium.

Ciprofloxacin resistance in community- and hospital-acquired Escherichia coli urinary tract infections: a systematic review and meta-analysis of observational studies

Background

During the last decade the resistance rate of urinary Escherichia coli (E. coli) to fluoroquinolones such as ciprofloxacin has increased. Systematic reviews of studies investigating ciprofloxacin resistance in community- and hospital-acquired E. coli urinary tract infections (UTI) are absent. This study systematically reviewed the literature and where appropriate, meta-analysed studies investigating ciprofloxacin resistance in community- and hospital-acquired E. coli UTIs.

Methods

Observational studies published between 2004 and 2014 were identified through Medline, PubMed, Embase, Cochrane, Scopus and Cinahl searches. Overall and sub-group pooled estimates of ciprofloxacin resistance were evaluated using DerSimonian-Laird random-effects models. The I² statistic was calculated to demonstrate the degree of heterogeneity. Risk of bias among included studies was also investigated.

Results

Of the identified 1134 papers, 53 were eligible for inclusion, providing 54 studies for analysis with one paper presenting both community and hospital studies. Compared to the community setting, resistance to ciprofloxacin was significantly higher in the hospital setting (pooled resistance 0.38, 95 % CI 0.36-0.41 versus 0.27, 95 % CI 0.24-0.31 in community-acquired UTIs, P < 0.001). Resistance significantly varied by region and country with the highest resistance observed in developing countries. Similarly, a significant rise in resistance over time was seen in studies reporting on community-acquired E. coli UTI.

Conclusions

Ciprofloxacin resistance in E. coli UTI is increasing and the use of this antimicrobial agent as empirical therapy for UTI should be reconsidered. Policy restrictions on ciprofloxacin use should be enhanced especially in developing countries without current regulations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1282-4) contains supplementary material, which is available to authorized users.

The challenge of antibiotic resistance in haematology patients

Bacterial infections were once a major obstacle to the treatment of acute leukaemia. Improvement in management strategies, including the use of broad-spectrum antibacterial drugs targeting Gram-negative bacteria, has reduced the mortality in neutropenic patients developing blood stream infections and other severe infections. In many countries these achievements are threatened by development of multi-resistant bacteria, such as Klebsiella pneumoniae, Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. This review addresses the epidemiology, clinical importance and possible management of these multi-resistant organisms.

Clinical and economic impact of urinary tract infections caused by ESBL-producing Escherichia coli requiring hospitalization: A matched cohort study

OBJECTIVE

To analyze the clinical and economic impact of urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli requiring hospitalization.

METHODS

Matched cohort study including adults with UTI caused by ESBL-producing E. coli admitted to a tertiary care hospital in Barcelona, Spain, between August 2010 and July 2013. Demographic, clinical and economic data were analyzed.

RESULTS

One hundred and twenty episodes of UTI were studied: 60 due to ESBL-producing E. coli and 60 due to non-ESBL-producing E. coli. Bivariate analysis showed that prior antimicrobial treatment (p = 0.007) and ESBL production (p < 0.001) were related to clinical failure during the first 7 days. Multivariate analysis selected ESBL as the sole risk factor for clinical failure (p = 0.002). Regarding the economic impact of infections caused by ESBL-producing E. coli, an ESBL-producing infection cost more than a non-ESBL-producing E. coli infection (mean €4980 vs. €2612). Looking at hospital expenses separately, the total pharmacy costs and antibiotic costs of ESBL infections were considerably higher than for non-ESBL infections (p < 0.001), as was the need for outpatient parenteral antibiotic therapy (OPAT) and its related costs. Multivariate analysis performed for the higher costs of UTI episodes found statistically significant differences for males (p = 0.004), chronic renal failure (p = 0.025), ESBL production (p = 0.008) and OPAT (p = 0.009).

CONCLUSION

UTIs caused by EBSL-producing E. coli requiring hospital admission are associated with worse clinical and economic outcomes.

Febrile urinary tract infection in the emergency room

PURPOSE OF REVIEW

To review the recent advances in the diagnostic and therapeutic approach to adults presenting with febrile urinary tract infection (UTI) in the emergency department (ED).

RECENT FINDINGS

Recent research suggests overdiagnosis and therefore overtreatment of UTI in the ED, especially in the elderly. Antimicrobial pretreatment, an indwelling catheter, and malignancy are independent risk factors for bacteremia with uropathogens that cannot be cultured from urine. A simple clinical prediction rule can predict clinically relevant radiologic findings in patients with invasive UTI. Procalcitonin is a marker for bacteremia; pro-adrenomedullin predicts a complicated course and 30-day mortality in complicated UTI. Several reports have identified the risk factors for resistant uropathogens in community-acquired febrile UTI. Adherence to the guidelines and early culture-guided intravenous-to-oral switch reduces the length of hospitalization.

SUMMARY

An effective strategy is needed to improve the diagnosis of UTIs in acute care. Further research regarding biomarker-guided triage might improve the management of patients with febrile UTI. Future efforts should be directed toward the improvement of adherence to UTI treatment guidelines.

Urinary tract infections and asymptomatic bacteriuria in older adults

Overuse of urinalysis in older adults to investigate vague changes in condition such as confusion, lethargy, and anorexia, has led to overtreatment of asymptomatic bacteriuria and associated antibiotic resistance.

Comparison of community-onset healthcare-associated and hospital-acquired urinary infections caused by extended-spectrum beta-lactamase-producing Escherichia coli and antimicrobial activities

OBJECTIVE

We aimed to compare community-onset healthcare-associated (CO-HCA) and hospital-acquired (HA) urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in terms of epidemiology, clinical outcomes and antimicrobial activities.

METHODS

Patients from both groups with ESBL-producing E. coli detected by urine culture between January 2009 and January 2011 were included in this retrospective study. Relevant demographical, microbiologic and clinical data were obtained from case records.

RESULTS

A total of 173 patients (mean age of 58 years, 74% female) were included, of whom 75 (43.4%) had a CO-HCA UTI and 98 (56.6%) had an HA UTI. Eighty (46.2%) patients had more than one comorbid disease, of whom 57 (32.5%) had urological problems. The most common clinical manifestations were pyelonephritis (43.9%) and urosepsis (16.2%). An age of > 65 years (p = 0.005) in addition to urinary catheterisation (p = 0.001), urosepsis (p = 0.001) and mortality (p = 0.001) were significantly more common in the HA UTI group. Acute cystitis (p = 0.027), complicated cystitis (p = 0.001) and non-urologic neoplasm (p = 0.032) were significantly more common in the CO-HCA UTI group. No isolate was resistant to carbapenems or fosfomycin. Sensitivities to nitrofurantoin, amikacin, trimethoprim sulfamethoxazole-trimoxazole and quinolones were 97.6%, 89%, 29.4% and 17.9% respectively. Both groups showed similar rates of antibiotic resistance.

CONCLUSION

ESBL-producing E. coli should be taken into consideration in patients with a CO HCA UTI, not only in hospital settings but also in outpatient settings. We suggest ertapenem as a first-line empirical treatment for patients with an upper UTI and fosfomycin and nitrofurantoin for those with a lower UTI when ESBL-producing E. coli is suspected.

ESBL-producing enterobacteriaceae-related urinary tract infections in kidney transplant recipients: incidence and risk factors for recurrence

BACKGROUND

Urinary tract infections (UTIs) represent the first cause of bacterial infections in renal transplant recipients. In a period of increasing resistance to antimicrobial agents, the factors leading to the development of UTI in previously urinary colonized renal transplant recipients as well as the factors associated with recurrence of UTIs have to be determined. The aims of this retrospective study were (1) to assess the incidence of extended-spectrum beta-lactamase-producing enterobacteriaceae (ESBL-PE)-related UTI in kidney transplant recipients, (2) to identify factors associated with ESBL-PE infection and (3) to determine the risk factors for recurrence.

METHODS

We included all kidney transplant recipients admitted in our hospital between January 2009 and January 2012 who had a monobacterial ESBL-PE UTI or bacteriuria.

RESULTS

During the study period, 659 patients underwent kidney transplantation; 72 patients had ESBL-PE bacteriuria, representing a 10.9% prevalence, and among the latter 34 (47.2%) presented an ESBL-PE-related UTI. Fourteen patients (41.2%) experienced a UTI relapse associated with two factors: advanced age (p = 0.032) and persistent bacteriuria 48 h after appropriate antibiotic therapy (p = 0.04). No other risk factor for recurrence was found, including the presence and management of a ureteral stent during the first UTI, causative microorganisms, or diabetes mellitus.

CONCLUSIONS

In this specific population, regarding the risk of relapse there is an urgent need for prospective studies to test the best treatment strategy.

Extended spectrum β-lactamase producers among nosocomial Enterobacteriaceae in Latin America

To review the epidemiology of nosocomial extended spectrum β-lactamase-producing Enterobacteriaceae in Latin America, a systematic search of the biomedical literature (PubMed) was performed for articles published since 2005. Rates of nosocomial infections caused by extended spectrum β-lactamase-producing Enterobacteriaceae in Latin America have increased since 2005. Up to 32% of Escherichia coli and up to 58% of Klebsiella pneumoniae isolates are extended spectrum β-lactamase-positive, rates that are higher than in other world regions. From a region-wide perspective, 11–25% of E. coli isolates and 45–53% of K. pneumoniae isolates were nonsusceptible to third-generation cephalosporins. At the country level, there was a wide range in Enterobacteriaceae resistance rates to third-generation cephalosporins, with especially high rates of resistance to E. coli in Guatemala, Honduras, and Mexico, and high resistance rates to Klebsiella spp. in Argentina, Brazil, Chile, Guatemala, Honduras, and Paraguay. Susceptibility of extended spectrum β-lactamase-producing Enterobacteriaceae to cefepime, fluoroquinolones, ampicillin/sulbactam, aminoglycosides, and piperacillin/tazobactam has also been compromised, leaving the carbapenems, tigecycline, and colistin as the only antibiotics with >90% susceptibility rates. There is a steady increase in the prevalence and types of extended spectrum β-lactamases produced by Enterobacteriaceae isolates in Latin American hospitals (particularly CTX-Ms), suggesting endemic conditions overlaid by clonal outbreaks. Appropriate treatment decisions and infection control strategies informed by surveillance of regional and local susceptibilities and mechanisms of resistance are required to mitigate this major public health concern.

Impact of extended-spectrum β-lactamase-producing organisms on clinical and economic outcomes in patients with urinary tract infection

OBJECTIVE

To compare clinical and economic outcomes between patients with urinary tract infection (UTI) due to extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella species (ESBL-EK) versus patients with non-ESBL-EK UTI.

PATIENTS AND METHODS

Eighty-four (3.6%) of 2345 patients admitted between September 1, 2011 and August 31, 2012 with UTI were positive for ESBL-EK. Fifty-five ESBL-EK UTI (cases) and matched controls (non-ESBL-EK UTI) were included in the analysis. Clinical and economic outcomes were compared between cases and controls for statistical significance.

RESULTS

Cases were more likely to have diabetes mellitus, a history of recurrent UTIs, recently received antibiotics, recently been hospitalized, and had previous isolation of an ESBL-producing organism compared with controls. Failure of initial antibiotic regimen (62% vs 6%; P < 0.001) and time to appropriate antibiotic therapy (51 vs 2.5 hours; P < 0.001) were greater in cases. The median cost of care was greater (additional $3658; P = 0.02) and the median length of stay (LOS) prolonged for cases (6 vs 4 days; P = 0.02) despite similar hospital reimbursement (additional $469; P = 0.56). Although not significant, infection-related mortality (7.2% vs 1.8%) and 30-day UTI readmission (7.2% vs 3.6%) were higher in ESBL-EK cases.

CONCLUSIONS

UTI caused by ESBL-EK is associated with significant clinical and economic burden. The cost of care and LOS of patients with ESBL-EK UTI were 1.5 times those caused by non-ESBL-EK. Importantly, the additional cost of care is a liability to the hospital, as this is not offset by reimbursement. Appropriate and timely initial antibiotics may minimize the ESBL-EK impact on outcomes of patients with UTI.

Ceftazidime-avibactam: an evidence-based review of its pharmacology and potential use in the treatment of Gram-negative bacterial infections

Avibactam (NXL104, AVE1330A) is a semi-synthetic, non-β-lactam, β-lactamase inhibitor that is active against Ambler class A, class C, and some class D serine β-lactamases. In this review, we summarize the in vitro data, pharmacology, mechanisms of action and resistance, and clinical trial data relating to the use of this agent combined with ceftazidime for the treatment of Gram-negative bacterial infections. The addition of avibactam to ceftazidime improves its in vitro activity against Enterobacteriaceae and Pseudomonas aeruginosa. Avibactam does not improve the activity of ceftazidime against Acinetobacter spp., Burkholderia spp., or most anaerobic Gram-negative rods. Pharmacodynamic data indicate that ceftazidime—avibactam is bactericidal at concentrations achievable in human serum. Animal studies demonstrate that ceftazidime–avibactam is effective in ceftazidime-resistant Gram-negative septicemia, meningitis, pyelonephritis, and pneumonia. Limited clinical trials published to date have reported that ceftazidime–avibactam is as effective as therapy with a carbapenem in complicated urinary tract infection and complicated intra-abdominal infection (combined with metronidazole) including infection caused by cephalosporin-resistant Gram-negative isolates. Safety and tolerability of ceftazidime–avibactam in clinical trials has been excellent, with few serious drug-related adverse events reported. Given the abundant clinical experience with ceftazidime and the significant improvement that avibactam provides in its activity against contemporary β-lactamase-producing Gram-negative pathogens, it is likely this new combination agent will play a role in the empiric treatment of complicated urinary tract infections (monotherapy) and complicated intra-abdominal infections (in combination with metronidazole) caused or suspected to be caused by antimicrobial-resistant pathogens (eg, extended spectrum beta-lactamase-, AmpC-, or Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae and multidrug-resistant P. aeruginosa). Potential future uses also include hospital-acquired pneumonia (in combination with antistaphylococcal and antipneumococcal agents) or treatment of skin and soft tissue infections caused by antimicrobial-resistant Gram-negative pathogens (eg, diabetic foot infections), but further clinical trials are required.

Rates of fecal transmission of extended-spectrum β-lactamase-producing and carbapenem-resistant Enterobacteriaceae among patients in intensive care units in Korea

Background

We investigated the rates of fecal transmission of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) and carbapenem-resistant Enterobacteriaceae (CRE) among patients admitted to intensive care units (ICUs).

Methods

From June to August 2012, rectal cultures were acquired from all patients at ICU admission. For patients not carrying ESBL-E or CRE at admission, follow-up cultures were performed to detect acquisition. A chromogenic assay was used to screen for ESBL-E and CRE. Bacterial species identification and antibiotic susceptibility tests were performed using the Vitek 2 system (bioMérieux, France). ESBL genotypes were determined by PCR, and clonal relatedness of the isolates was assessed by pulsed-field gel electrophoresis.

Results

Out of 347 ICU admissions, 98 patients were found to be carriers of ESBL-E (28.2%, 98/347). Follow-up cultures were acquired from 91 of the patients who tested negative for ESBL-E at admission; the acquisition rate in this group was 12.1% (11/91), although none was a nosocomial transmission. For CRE, the prevalence of fecal carriage was 0.3% (1/347), and the acquisition rate was 2.9% (4/140). None of the CRE isolates were carbapenemase-producers.

Conclusions

The high prevalence of ESBL-E carriage on admission (28.2%), coupled with rare nosocomial transmission and the very low carriage rate of CRE (0.3%), challenge the routine use of active surveillance in non-epidemic settings. Nevertheless, passive surveillance measures, such as rapid and accurate screening of clinical specimens, will be critical for controlling the spread of CRE.

Antimicrobial susceptibility pattern and epidemiology of female urinary tract infections in South Korea, 2010-2011

This study aimed to (i) investigate the antimicrobial susceptibilities of bacteria that cause urinary tract infections (UTIs) in outpatient and inpatient settings and (ii) evaluate the risk factors for emerging antimicrobial drug resistance in UTIs in South Korea. In total, 3,023 samples without duplication were collected from females between 25 and 65 years of age who had been diagnosed with a urinary tract infection. Multicenter patient data were collected using a Web-based electronic system and then evaluated. The isolation rates of Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecium in the outpatient setting were 78.1, 4.7, and 1.3%, respectively; in the inpatient setting, the isolation rates of these microorganisms were 37.8, 9.9, and 14.8%, respectively. The susceptibilities of E. coli to amikacin, amoxicillin-clavulanic acid, cefotaxime, cefoxitin, ciprofloxacin, piperacillin-tazobactam, and imipenem in the outpatient setting were 99.4, 79.8, 89.4, 92.8, 69.8, 96.9, and 100.0%, respectively; in the inpatient setting, the susceptibilities to these antibiotics were 97.8, 73.9, 73.7, 82.1, 53.6, 93.2, and 100.0%, respectively. The most unique and common risk factor for emerging antimicrobial-resistant E. coli, K. pneumoniae, and E. faecium was previous exposure to antimicrobials. On the basis of these data, the use of fluoroquinolones should be reserved until culture data are available for the treatment of UTIs in South Korea. The present study will serve as a useful reference for Far Eastern Asia.