Risk factors, outcome and impact of empirical antimicrobial treatment in extended-spectrum β-lactamase-producing Escherichia coli bacteraemia

Disease burden of bacteraemia with extended-spectrum beta-lactamase-producing and carbapenem-resistant Enterobacterales in Korea

BACKGROUND

Despite the significant impact of multi-drug-resistant bacteraemia, especially extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) and carbapenem-resistant Enterobacterales (CRE), the burden of disease has not been investigated thoroughly.

AIM

To evaluate the clinical outcomes and socio-economic burden of ESBL-E and CRE bacteraemia nationwide in the Republic of Korea.

METHODS

A search was undertaken for all cases of ESBL-E and CRE bacteraemia and matched controls in 10 hospitals in the Republic of Korea over 6 months. Patients with ESBL-E or CRE bacteraemia were classified as the R group, and matched controls with antibiotic-susceptible bacteraemia and without infection were classified as the S and N groups, respectively. Patients' clinical data were collected, and the economic burden was estimated based on medical expenses, loss of productivity and total costs.

FINDINGS

In total, 795 patients were identified, including 265 patients with ESBL-E or CRE bacteraemia and their matched controls. The mean total length of stay for patients with ESBL-E and CRE in the R group was 1.53 and 1.90 times that of patients in the S group, respectively. The 90-day mortality rates for ESBL-E in the R and S groups were 12.1% and 5.6%, respectively, and the corresponding figures for CRE were 28.6% and 12.0%. There were significant differences in the total costs between the R, S and N groups for both ESBL-E and CRE (ESBL-E: $11,151 vs $8712 vs $6063, P=0.004; CRE: $40,464 vs $8748 vs $7279, P=0.024).

CONCLUSION

The clinical and economic burden imposed by ESBL-E or CRE bacteraemia was extremely high. These findings suggest that efforts to control resistant bacteraemia are necessary to reduce this burden.

Predictors for onset of extended-spectrum beta-lactamase-producing Escherichia coli-induced bacteraemia: a systematic review and meta-analysis

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli bacteraemia can induce unfavourable clinical outcomes due to delay in appropriate antimicrobial treatment and limited therapeutic options. Therefore, elucidating the predictors of ESBL-producing E. coli-induced bacteraemia is crucial to improve clinical outcomes. However, a literature search did not reveal any studies that incorporate a meta-analysis of the predictors of ESBL-producing E. coli-induced bacteraemia. As such, this review was undertaken to assess current evidence on the predictors of ESBL-producing E. coli-induced bacteraemia. PubMed, Web of Science and Cochrane Library databases were searched for all relevant publications from January 2000 to September 2021. This systematic review evaluated 10 observational studies, comprising a total of 2325 patients with E. coli-induced bacteraemia and 850 (36.6%) ESBL-producing strains. In the meta-analysis, previous antibiotic therapy [pooled risk ratio (RR) 2.72; P<0.001], especially with cephalosporins (pooled RR 4.66; P<0.001) and quinolones (pooled RR 5.47; P<0.001), and urinary catheter use (pooled RR 3.79; P<0.001) were predictive of ESBL-producing E. coli-induced bacteraemia. Antibiotic therapy for patients with the above-mentioned risk factors should be selected considering the possibility of ESBL-producing E. coli-induced bacteraemia compared with non-ESBL-producing E. coli-induced bacteraemia. It is important to elucidate whether appropriate modulation of the identified risk factors can potentially mitigate the risk of ESBL-producing E. coli-induced bacteraemia compared with non-ESBL-producing E. coli-induced bacteraemia.

Carriage of Extended Spectrum Beta Lactamase-Producing Escherichia coli: Prevalence and Factors Associated with Fecal Colonization of Dogs from a Pet Clinic in Lower Saxony, Germany

Extended spectrum beta-lactamase (ESBL)-producing Escherichia coli are an emerging problem in veterinary and human medicine. Our study concentrated on the estimation of the prevalence and factors associated with the carriage of ESBL-producing E. coli in dogs who visited a veterinary clinic in northern Germany in 2017. For this reason, 1000 patients (healthy and sick dogs) were tested, resulting in 1000 samples originating from rectal swabs. Additional data were collected using a self-reported questionnaire that was completed by the dog owner. Factors associated with ESBL carriage were considered for further modeling if p < 0.05 using a two-sided Fisher test. Using a backward elimination procedure, the variables for the final multivariable logistic regression model were identified. In total, 8.9% of the dogs tested were positive for carriage of ESBL-producing E. coli. Seven factors were associated with the colonization of dogs with ESBL-E. coli within the multivariable model, namely husbandry system (p = 0.0019, OR = 3.00; 95% CI: 1.50-6.00), contact with puppies (p = 0.0044, OR = 2.43; 95% CI: 1.32-4.46), feeding of raw meat (p = 0.011, OR = 2.28; 95% CI: 1.21-4.31), food residues (p = 0.0151, OR = 2.31; 95% CI: 1.18-4.53) and food supplements (p = 0.0487, OR = 0.426; 95% CI: 0.18-0.96), and antibiotic treatments of dogs (p = 0.0005, OR = 3.030; 95% CI: 1.62-5.68) or owners (p = 0.041, OR = 2.74; 95% CI: 1.04-7.19) prior to the study. These factors refer to the animals themselves as well as to the owners and their habits or medical treatments. Although the causality and direction of transmission from owners to their dogs cannot be proven, the factor of antibiotic treatment of the owner is clearly associated with the dog's status.

Increased incidence rates of positive blood cultures shortly after chemotherapy compared to radiotherapy among individuals treated for solid malignant tumours

BACKGROUND

Cancer treatments suppress immune function and are associated with increased risk of infections, but the overall burden of serious infectious diseases in treated patients has not been clearly elucidated.

METHODS

All patients treated for solid malignant tumours with radiotherapy (RT) and/or standard first-line chemotherapy (C) at the Department of Oncology at Rigshospitalet between 01/1/2010 and 31/12/2016 were included. Patients were followed from treatment initiation until the first of new cancer treatment, 1 year after treatment initiation, end of follow-up or death. Incidence rates (IR) of positive blood culture (PBC) per 1000 person-years follow-up (PYFU) were calculated.

FINDINGS

12,433 individuals were included, 3582 (29%), 6349 (51%), and 2502 (20%) treated with RT, C, or both RT & C, respectively, contributing 8182 PYFU. 429 (3%) individuals experienced 502 unique episodes of PBC, incidence rate (95% CI) 52.43 (47.7, 57.6) per 1000 PYFU. The 30-day mortality rate after PBC was 24% independent of treatment modality. Adjusted incidence rate ratios in the first 3 months (95% CI) after PBC significantly varied by treatment: 2.89 (1.83, 4.55) and 2.52 (1.53, 4.14) for C and RT & C compared to RT. Escherichia coli (n = 127, 25%) was the top microorganism identified.

INTERPRETATION

PBCs are not common, but when they occur, mortality is high.

Risk factors and outcome due to extended-spectrum β-lactamase-producing uropathogenic Escherichia coli in community-onset bloodstream infections: A ten-year cohort study in Sweden

Objective

To study clinical outcome and risk factors associated with extended-spectrum β-lactamase (ESBL)-producing uropathogenic Escherichia coli (UPEC) in community-onset bloodstream infections (CO-BSI).

Methods

This was a population-based cohort study including patients with pheno- and genotype-matched ESBL-producing E. coli and non-ESBL- E. coli in urine and blood samples collected in 2009–2018 in southeast Sweden. Seventy-seven episodes of ESBL-UPEC satisfying the inclusion criteria were matched 1:1 with 77 non-ESBL-UPEC for age, gender, and year of culture.

Results

The most common ST-type and ESBL gene was ST131 (55%), and bla_CTX-M-15 (47%), respectively. Risk factors for ESBL-UPEC were: previous genitourinary invasive procedure (RR 4.66; p = 0.005) or history of ESBL-producing E. coli (RR 12.14; p = 0.024). There was significant difference between ESBL-UPEC and non-ESBL-UPEC regarding time to microbiologically appropriate antibiotic therapy (27:15 h vs. 02:14 h; p = <0.001) and hospital days (9 vs. 5; p = <0.001), but no difference in 30-day mortality (3% vs. 3%; p = >0.999) or sepsis within 36 hours (51% vs. 62%; p = 0.623) was observed.

Conclusion

The predominant risk factors for ESBL-UPEC were history of ESBL-Ec infection and history of genitourinary invasive procedure. The overall mortality was low and the delay in appropriate antibiotic therapy did not increase the risk for 30-day mortality or risk for sepsis within 36 hours among patients infected with ESBL UPEC. However, these results must be regarded with some degree of caution due to the small sample size.

Identifying the Sources of Intestinal Colonization With Extended-Spectrum β-Lactamase-Producing Escherichia coli in Healthy Infants in the Community

The prevalence of fecal colonization with extended-spectrum β-lactamase-producing Escherichia coli (ESBL-Ec) among children in low- and middle-income countries is alarmingly high. This study aimed to identify the sources of ESBL-Ec colonization in children &lt; 1 year old through comparative analysis of E. coli isolates from child stool, child’s mother stool, and point-of-use drinking water from 46 rural households in Bangladesh. The pairwise similarity in antibiotic susceptibility of E. coli from all three sources was evaluated, followed by phylogenetic clustering using enterobacterial repetitive intergenic consensus polymerase chain reaction and whole-genome sequence analysis of the isolates. Matching antibiotic susceptibility and enterobacterial repetitive intergenic consensus polymerase chain reaction patterns were found among ESBL-Ec isolates from child–mother dyads of 24 and 11 households, respectively, from child–water dyads of 5 and 4 households, respectively, and from child–mother–water triads of 3 and 4 households, respectively. Whole-genome sequence analysis of 30 isolates from 10 households revealed that ESBL-Ec from children in five households (50%) was clonally related to ESBL-Ec either from their mothers (2 households), drinking water sources (2 households), or both mother and drinking-water sources (1 household) based on serotype, phylogroup, sequence type, antibiotic resistance genes, mobile genetic elements, core single-nucleotide polymorphisms, and whole-genome multilocus sequence typing. Overall, this study provides empirical evidence that ESBL-Ec colonization in children is linked to the colonization status of mothers and exposure to the household environments contaminated with ESBL-Ec. Interventions such as improved hygiene practices and a safe drinking water supply may help reduce the transmission of ESBL-Ec at the household level.

Prevalence and Molecular Characterization of Extended Spectrum β-Lactamase and Carbapenemase-Producing Enterobacteriaceae Isolates from Bloodstream Infection Suspected Patients in Addis Ababa, Ethiopia

Background

Production of Extended spectrum beta-lactamase (ESBL) and Carbapenemase is the most common strategy for drug resistance in clinical isolates of Enterobacteriaceae. This study was conducted to determine the magnitude of ESBL and Carbapenemase production (CPE) among clinical isolates of Enterobacteriaceae causing bloodstream infections (BSI) in Ethiopia.

Methods

A cross-sectional study was performed from September 2018 to January 2019 in Ethiopia. A total of 2397 BSI suspected patients were enrolled and blood culture was performed using a BacT/Alert instrument in combination with conventional methods for identification. After antimicrobial susceptibility test, phenotypic confirmation of ESBLs was done by combined disc-diffusion. Meanwhile carbapenemase production was done by modified carbapenem inactivation method. Multiplex PCR was conducted to detect the presence of bla_CTX-M,bla_SHV,bla_TEM, bla_KPC and bla_NDM genes.

Results

A total of 104 (4.3%) Enterobacteriaceae were isolated from 2397 BSI suspected patients. Klebsiella pneumoniae (55/104, 52%) was the predominant isolate followed by E. coli, (19.2%, 20/104) and K.oxytoca (17.3%, 18/104). ESBL and carbapenemase production were observed from 70 (67.3%, 57.4 −76.2% at 95% CI) and 8 (7.7%, 3.4–14.6% at 95% CI) isolates respectively. The highest frequency of ESBL and carbapenemase production was observed in K. pneumoniae 78.2% (43/55) and 9.1% (5/55), respectively. All the 70 isolates confirmed as ESBL producers harbored at least one of the ESBL genes and the majority of them carried multiple beta-lactamase genes (84.3%), where bla_CTX-M, type was the most predominant (67.3%). Similarly, the entire eight isolates positive for carbapenemase carried bla_NDM but none of them carried bla_KPC.

Conclusion

In our study, the rate of ESBL production among BSI-causing Enterobacteriaceae was alarming and most of the isolates carried multiple types of ESBL genes. A significant magnitude of CPE isolates causing BSI was recorded.

Clinical prediction tool for extended-spectrum beta-lactamase-producing enterobacterales as the etiology of a bloodstream infection in solid organ transplant recipients

BACKGROUND

Multidrug-resistant Gram-negative bacterial infections are increasingly common among solid organ transplant (SOT) recipients, leading to challenges in the selection of empiric antimicrobial therapy. We sought to develop a clinical tool to predict which SOT recipients are at high risk for extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (EB) bloodstream infection (BSI).

METHODS

A multicenter case-control study was performed. The source population included SOT recipients with an EB BSI between 2005 and 2018. Cases were those with ESBL-EB BSI; controls were those with non-ESBL EB BSI. The population was subdivided into derivation and validation cohorts based on study site. The predictive tool was developed in the derivation cohort through iterative multivariable logistic regression analyses that maximized the area under the receiver-operating curve (AUC). External validity was assessed using the validation cohort.

RESULTS

A total of 897 SOT recipients with an EB BSI were included, of which 539 were assigned to the derivation cohort (135, 25% ESBL-EB) and 358 to the validation cohort (221, 62% ESBL-EB). Using multivariable analyses, the most parsimonious model that was predictive of ESBL-EB BSI consisted of 10 variables, which fell into four clinical categories: prior colonization or infection with EB organisms, recent antimicrobial exposures, severity of preceding illness, and immunosuppressive regimen. This model achieved an AUC of 0.81 in the derivation cohort and 0.68 in the validation cohort.

CONCLUSIONS

Though further refinements are needed in additional populations, this tool shows promise for guiding empiric therapy for SOT recipients with EB BSI.

Measures used to assess the burden of ESBL-producing Escherichia coli infections in humans: a scoping review

Background

ESBL-producing bacteria pose a serious challenge to both clinical care and public health. There is no standard measure of the burden of illness (BOI) of ESBL-producing Escherichia coli (ESBL-EC) in the published literature, indicating a need to synthesize available BOI data to provide an overall understanding of the impact of ESBL-EC infections on human health.

Objectives

To summarize the characteristics of BOI reporting in the ESBL-EC literature to (i) describe how BOI associated with antimicrobial resistance (AMR) is measured and reported; (ii) summarize differences in other aspects of reporting between studies; and (iii) highlight the common themes in research objectives and their relation to ESBL-EC BOI.

Methods and results

Two literature searches, run in 2013 and 2018, were conducted to capture published studies evaluating the BOI associated with ESBL-EC infections in humans. These searches identified 1723 potentially relevant titles and abstracts. After relevance screening of titles and abstracts and review of full texts, 27 studies were included for qualitative data synthesis. This review identified variability in the reporting and use of BOI measures, study characteristics, definitions and laboratory methods for identifying ESBL-EC infections.

Conclusions

Decision makers often require BOI data to make science-based decisions for the implementation of surveillance activities or risk reduction policies. Similarly, AMR BOI measures are important components of risk analyses and economic evaluations of AMR. This review highlights many limitations to current ESBL-EC BOI reporting, which, if improved upon, will ensure data accessibility and usefulness for ESBL-EC BOI researchers, decision makers and clinicians.

Evaluation of the health and healthcare system burden due to antimicrobial-resistant Escherichia coli infections in humans: a systematic review and meta-analysis

BACKGROUND

Assessment of the burden of disease due to antimicrobial-resistant Escherichia coli infections facilitates understanding the scale of the problem and potential impacts, and comparison to other diseases, which allows prioritization of research, surveillance, and funding. Using systematic review and meta-analysis methodology, the objectives were to evaluate whether humans with antimicrobial-resistant E. coli infections experience increases in measures of health or healthcare system burden when compared to susceptible E. coli infections.

METHODS

Comprehensive literature searches were performed in four primary and seven grey literature databases. Analytic observational studies of human E. coli infections that assessed the impact of resistance to third/fourth/fifth-generation cephalosporins, resistance to quinolones, and/or multidrug resistance on mortality, treatment failure, length of hospital stay and/or healthcare costs were included. Two researchers independently performed screening, data extraction, and risk of bias assessment. When possible, random effect meta-analyses followed by assessment of the confidence in the cumulative evidence were performed for mortality and length of hospital stay outcomes, and narrative syntheses were performed for treatment failure and healthcare costs.

RESULTS

Literature searches identified 14,759 de-duplicated records and 76 articles were included. Based on 30-day and all-cause mortality meta-analyses, regardless of the type of resistance, there was a significant increase in the odds of dying with resistant E. coli infections compared to susceptible infections. A summary mean difference was not presented for total length of hospital stay meta-analyses due to substantial to considerable heterogeneity. Since small numbers of studies contributed to meta-analyses for bacterium-attributable mortality and post-infection length of hospital stay, the summary results should be considered with caution. Studies contributing results for treatment failure and healthcare costs had considerable variability in definitions and reporting.

CONCLUSIONS

Overall, resistant E. coli infections were associated with significant 30-day and all-cause mortality burden. More research and/or improved reporting are necessary to facilitate quantitative syntheses of bacterium-attributable mortality, length of hospital stay, and hospital costs. Protocol Registration PROSPERO CRD42018111197.

A Cross-Sectional Cohort Study of Extended-Spectrum-Beta-Lactamase-Producing Enterobacterales in Patients with Traveler's Diarrhea

Patients with traveler's diarrhea (TD) can acquire extended-spectrum-beta-lactamase (ESBL)-producing members of the Enterobacterales (EPE) during travel to areas of endemicity. The aim of the present study was to investigate the prevalence and characteristics of EPE carriage in travelers from southern Sweden who were sampled for bacterial diagnostics of TD compared to those of EPE carriage 10 years ago. Clinical samples sent for culture of common causes of bacterial enterocolitis, if the referral stated foreign travel, were included in the study. Antimicrobial susceptibility testing was done according to the EUCAST disk diffusion test method. EPE strains were subjected to whole-genome sequencing (WGS). Eighty-four of 303 patients carried a total of 92 ESBL-producing members of the Enterobacterales The overall prevalence of EPE in tested samples was thus 28%, compared to 24% 10 years earlier (P = 0.33). Among 86 strains available for WGS, 47 different sequence types (STs) were identified, and there were only 5 ST131 strains. Of the 79 Escherichia coli isolates, 76% carried at least one fim (type 1 fimbria) gene, 29% carried at least one pap (p-fimbriae) gene, and 43% were extraintestinal pathogenic E. coli (ExPEC) or uropathogenic E. coli (UPEC). Over half of the E. coli strains (57%) were intestinal pathogenic E. coli, most commonly enteroaggregative E. coli (EAEC) (33%), and enteroinvasive E. coli EIEC (22%). A relatively high proportion of patients with traveler's diarrhea carry EPE, but there was no significant increase compared to 10 years ago. Most E. coli strains were intestinal pathogenic strains. A comparatively high proportion of the strains were ExPEC/UPEC, many expressing the virulence genes pap and/or fim (This project was assigned ClinicalTrials.gov number NCT03866291.).

Temporal Dynamics and Risk Factors for Bloodstream Infection With Extended-spectrum β-Lactamase-producing Bacteria in Previously-colonized Individuals: National Population-based Cohort Study

Background

Little is known of the long-term risks of bloodstream infection (BSI) with extended spectrum β-lactamase-producing Enterobacteriaceae (EPE) in previously-colonized individuals. We investigated EPE-BSI risks and associated risk factors during 6 years following EPE colonization.

Methods

We performed a population-based cohort study in Sweden using national health registers. Subjects were followed from their first EPE finding in feces (n = 5513) or urine (n = 17189). The effects of co-morbidity, sociodemography, and outpatient antibiotic dispensation on EPE-BSI risks were assessed. The EPE-BSI risks were compared to those of 45161 matched population-based reference subjects.

Results

The cumulative 6-year EPE-BSI incidences were 3.8%, 1.6%, and 0.02% in the urine, feces, and reference cohorts, respectively. The incidences decreased exponentially during the first 6-12 months. Among EPE-exposed subjects, urological disorders were associated with the highest adjusted cause-specific hazard ratio (aCSHR) for subsequent EPE-BSIs (3.40, 95% confidence interval 2.47-4.69). The aCSHRs were between 1.62-2.20 for male sex, immunosuppression, diabetes, malignancy, lung disease, baseline urine source, and Klebsiella pneumoniae, compared to the Escherichia coli baseline sample. Antibiotics with selective activity against gram-negative bacilli-but mostly not EPE (trimethoprim-sulfamethoxazole, fluoroquinolones, oral cephalosporins, and penicillins with extended spectrums)-and pivmecillinam were associated with doubled EPE BSI risk during the 3 months after antibiotic dispensation in EPE-colonized subjects.

Conclusions

EPE in urine or feces is a substantial risk factor for subsequent EPE-BSIs, but the risk declines rapidly during the first year after detection. In EPE-colonized individuals, specific risk factors can be used to identify subgroups for targeted interventions, such as eradication therapy.

An easy-to-use scoring system for predicting bacteraemia with third-generation cephalosporin-resistant Enterobacterales in a low-resistance setting

Background: The incidence of third-generation cephalosporin-resistant Enterobacterales (3GCR-E) is increasing and a growing number of patients risk receiving inappropriate initial antibiotic treatment. Published scoring systems for predicting 3GCR-E bacteraemia are mostly based on studies from countries with a high incidence. In this study, we aimed to create an easy-to-use scoring system for predicting bacteraemia with these bacteria in a low-resistance setting.Materials and methods: Factors associated with 3GCR-E were studied retrospectively in a cohort of patients with Enterobacterales bacteraemia using uni- and multivariate analysis. A scoring system was constructed and was validated in a separate cohort of patients with Enterobacterales bacteraemia.Results: The derivation cohort comprised 625 cases of Enterobacterales bacteraemia. Three variables (previous hospital care abroad, 3GCR-E in a previous blood or urine culture and 3GCR-E in a previous rectal swab culture) were significantly associated with 3GCR-E bacteraemia. A scoring system, where at least one positive parameter equalled a positive score, was studied in the validation cohort, which comprised 675 cases of Enterobacterales bacteraemia. The sensitivity and specificity of the score were 53% and 95%, respectively. Positive and negative predictive values were 38% and 97%, respectively.Conclusions: This study presents an easy-to-use scoring system for predicting bacteraemia with 3GCR-E. The performance of the score is similar to that of several other, more complicated, scoring systems, developed in countries with higher rates of resistance. The minimal extra effort required to use this new score could facilitate its introduction into clinical routine.

Cefuroxime compared to piperacillin/tazobactam as empirical treatment of Escherichia coli bacteremia in a low Extended-spectrum beta-lactamase (ESBL) prevalence cohort

Objectives: On January 18, 2010, a part of the capital region of Denmark shifted the empirical treatment of febrile conditions from cefuroxime to piperacillin/tazobactam. We compare empirical treatment with piperacillin/tazobactam versus cefuroxime for Escherichia coli bacteremia with regard to 14 days mortality, in a low prevalence cohort of Extended-spectrum beta-lactamase-producing E. coli. Methods: From January 18, 2010 to December 31, 2012, we conducted a retrospective cohort study including patients with E. coli bacteremia from six university hospitals in Copenhagen, Denmark. Clinical and laboratory information was obtained from a bacteremia research database, including information on comorbidity, and we used Cox proportional hazard analysis to asses all-cause 14 days mortality. Results: A total of 568 patients receiving either cefuroxime (n=377) or piperacillin/tazobactam (n=191) as empirical therapy were included. In the Cox proportional hazard model, cefuroxime treatment was significantly associated with death (mortality rate ratio 3.95, CI 1.12-13.90). Other variables associated with death were health care related infection (MRR 3.20, CI 1.67-6.15), hospital-acquired infection (MRR 2,17, CI 1.02-4.62), admission at intensive care unit (MRR 20.45, 5.31-78.82), and combination therapy with ciprofloxacin (MRR 2.14, CI 0.98-4.68). Conclusion: Empiric cefuroxime treatment of E. coli bacteremia was significantly associated with higher 14 days mortality in comparison with piperacillin/tazobactam.

Clinical Prediction Score for Community-Onset Bloodstream Infections Caused by Extended-Spectrum Beta-Lactamase-Producing Escherichia coli and Klebsiella Species

BACKGROUND

This study aimed to identify the predictors and build a prediction score for community-onset bloodstream infections (CO-BSIs) caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella species.

METHODS

All CO-BSIs caused by E. coli and Klebsiella species from 2012 to 2015 were grouped into derivation (BSIs from 2012 to 2014) and validation (BSIs in 2015) cohorts. A prediction score was built using the coefficients of the multivariate logistic regression model from the derivation cohort.

RESULTS

The study included 886 CO-BSIs (594 and 292 in the derivation and validation cohorts, respectively). The independent predictors of CO-BSIs caused by ESBL-producing E. coli and Klebsiella species included: 1) identification of ESBL-producing microorganisms from any clinical culture within one year of admission, 2) beta-lactam or fluoroquinolone treatment within 30 days (with 2 or more courses within 90 days; with 1 course within 90 days), 3) hospitalization within one year, 4) the presence of an indwelling urinary catheter at the time of admission. The area under the curve (AUC) of the clinical prediction score was 0.72 (95% confidence interval [CI], 0.68-0.77). In the validation cohort, the AUC was 0.70 (95% CI, 0.63-0.77).

CONCLUSIONS

The results of this study suggest a simple and easy-to-use scoring system to predict CO-BSIs caused by ESBL-producing E. coli and Klebsiella species.

Prediction of bloodstream infection caused by extended-spectrum β-lactamase-producing Enterobacterales in patients with suspected community-onset sepsis

OBJECTIVES

In severe infections, time to appropriate therapy is decisive for survival. Patients with bloodstream infection caused by extended-spectrum β-lactamase-producing Enterobacterales (EPE-BSI) often receive inadequate empirical treatment. This study aimed to identify risk factors, to evaluate a previously suggested risk score and to suggest a new score for facilitating empirical treatment choice.

METHODS

Predictors for EPE-BSI were assessed through a retrospective case-control design. The diagnostic performance of the two scores was evaluated. Included patients had blood cultures sampled at four EDs in Stockholm (2012-2015), were admitted, and received antibiotics with activity against Gram-negative bacilli.

RESULTS

A total of 277 EPE-BSI cases and 400 controls were included. The strongest predictor of EPE-BSI was prior EPE-positive culture (cases 33% vs. controls 3%; multivariate (MV) OR = 19.1). Recent EPE-positivity within ≤3 months had a univariate OR of 32.8. Other major predictors were recent prostate biopsy (14% vs. 1%; MV OR = 22.2) and healthcare abroad (6% vs. 2%; MV OR = 3.9). Several previously suggested risk factors were not associated with EPE-BSI. The previously developed Utrecht score had a sensitivity of 54% and a specificity of 77%. The Stockholm score suggested herein (prior EPE-positive culture/prostate biopsy/healthcare abroad) showed comparable sensitivity (50%) but better specificity (96%). Prediction in patients lacking major predictors was difficult and caused high false-positive rates, which would cause unnecessary overtreatment.

CONCLUSIONS

Prior EPE-positive culture, especially recently sampled, prostate biopsy and healthcare abroad were the strongest risk factors for community-onset EPE-BSI in Stockholm. Local data are needed when evaluating risk-scoring models before implementation.

Large variation in ESBL-producing Escherichia coli carriers in six European countries including Russia

We investigated the faecal carriage prevalence of extended-spectrum β-lactamase production in Escherichia coli (EP-EC) and/or Klebsiella pneumoniae (EP-KP) and risk factors associated with carriage among adult study subjects in Finland, Germany, Latvia, Poland, Russia and Sweden (partner countries). The aim was to get indicative data on the prevalence of ESBL-carriage in specific populations in the region. Faecal samples were collected from four study populations and screened on ChromID-ESBL and ChromID-OXA-48 plates. Positive isolates were further characterised phenotypically. Our results show a large variation in carrier prevalence ranging from 1.6% in Latvia to 23.2% in Russia for EP-EC. For the other partner countries, the prevalence of EP-EC were in increasing numbers, 2.3% for Germany, 4.7% for Finland, 6.6% for Sweden, 8.0% for Poland and 8.1% for all partner countries in total. Carriers of EP-KP were identified only in Finland, Russia and Sweden, and the prevalence was < 2% in each of these countries. No carriers of carbapenemase-producing isolates were identified. This is the first study reporting prevalence of carriers (excluding traveller studies) for Finland, Latvia, Poland and Russia. It contributes with important information regarding the prevalence of EP-EC and EP-KP carriage in regions where studies on carriers are limited.

Predicting Resistance to Piperacillin-Tazobactam, Cefepime and Meropenem in Septic Patients With Bloodstream Infection Due to Gram-Negative Bacteria

Background

Predicting antimicrobial resistance in gram-negative bacteria (GNB) could balance the need for administering appropriate empiric antibiotics while also minimizing the use of clinically unwarranted broad-spectrum agents. Our objective was to develop a practical prediction rule able to identify patients with GNB infection at low risk for resistance to piperacillin-tazobactam (PT), cefepime (CE), and meropenem (ME).

Methods

The study included adult patients with sepsis or septic shock due to bloodstream infections caused by GNB admitted between 2008 and 2015 from Barnes-Jewish Hospital. We used multivariable logistic regression analyses to describe risk factors associated with resistance to the antibiotics of interest (PT, CE, and ME). Clinical decision trees were developed using the recursive partitioning algorithm CHAID (χ2 Automatic Interaction Detection).

Results

The study included 1618 consecutive patients. Prevalence rates for resistance to PT, CE, and ME were 28.6%, 21.8%, and 8.5%, respectively. Prior antibiotic use, nursing home residence, and transfer from an outside hospital were associated with resistance to all 3 antibiotics. Resistance to ME was specifically linked with infection attributed to Pseudomonas or Acinetobacter spp. Discrimination was similar for the multivariable logistic regression and CHAID tree models, with both being better for ME than for PT and CE. Recursive partitioning algorithms separated out 2 clusters with a low probability of ME resistance and 4 with a high probability of PT, CE, and ME resistance.

Conclusions

With simple variables, clinical decision trees can be used to distinguish patients at low, intermediate, or high risk of resistance to PT, CE, and ME.

Management of infections caused by extended-spectrum β-lactamase-producing Enterobacteriaceae: current evidence and future prospects

INTRODUCTION

The spread of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae has become a major public health threat worldwide. Area covered: A thorough systematic literature review describing the current evidence and future prospects of therapeutic options for infections caused by ESBL-producing Enterobacteriaceae. Expert commentary: The methods of detecting ESBLs have been evolving. The Clinical and Laboratory Standards Institute and the European Committee on Antimicrobial Susceptibility Testing lowered the MIC breakpoints of cephalosporins against ESBL-producing Enterobacteriaceae in 2010. Phenotypic testing for ESBLs is no longer recommended. Instead, the selection of appropriate antimicrobial agents largely depends on the report of minimum inhibitory concentrations (MICs). To date, therapeutic options for these multidrug-resistant organisms remain limited. The clinical efficacy of piperacillin/tazobactam and cefepime on in vitro-susceptible ESBL-producing Enterobacteriaceae remains a concern. Many studies found an in vitro-in vivo discordance based on current breakpoints. Carbapenems are the most reliable antibiotics for severe infections caused by ESBL-producing Enterobacteriaceae. However, their overuse has led to a serious problem of increasing drug resistance. Recently, ceftolozane/tazobactam and ceftazidime/avibactam have been approved for the treatment of complicated urinary tract infections and complicated intra-abdominal infections. The introduction of these new β-lactam/β-lactamase inhibitor combinations offers new carbapenem-sparing options for the treatment of ESBL infections.

Secular trends in the appropriateness of empirical antibiotic treatment in patients with bacteremia: a comparison between three prospective cohorts

The objective of this study was to explore whether the percentage of inappropriate empirical antibiotic treatment in patients with bacteremia changed over time and to understand the factors that brought on the change. Three prospective cohorts of patients with bacteremia in three different periods (January 1st, 1988 to December 31st, 1989; May 1st, 2004 to November 30, 2004; May 1st, 2010 to April 30, 2011) were compared. Analysis was performed on a total of 811 patients. In 2010-2011, 55.9% (76/136) of patients with bacteremia received inappropriate empirical treatment, compared with 34.5% (170/493) and 33.5% (55/164) in the first and second periods, respectively, in a significant upward trend (p = 0.001). Resistance to antibiotics increased significantly during the study period. The following variables were included in the multivariate analysis assessing risk factors for inappropriate empirical treatment: study period (third period) [odds ratio, OR = 2.766 (95% confidence interval, CI, 1.655-4.625)], gender (male) [OR = 1.511 (1.014-2.253)], pathogen carrying extended-spectrum beta-lactamases [OR = 10.426 (4.688-23.187)], multidrug-resistant Acinetobacter baumannii [OR = 5.428 (2.181-13.513)], and skin/soft infections [OR = 3.23 (1.148-9.084)]. A model excluding microbiological data included: gender (male) [OR = 1.648 (1.216-2.234)], study period (third period) [OR = 2.446 (1.653-3.620)], hospital-acquired infection [OR = 1.551 (1.060-2.270)], previous use of antibiotics [OR = 1.815 (1.247-2.642)], bedridden patient [OR = 2.019 (1.114-3.658)], and diabetes mellitus [OR = 1.620 (1.154-2.274)]. We have observed a worrisome increase in the rate of inappropriate empirical treatment of bacteremia. We need tools that will allow us better prediction of the pathogen and its susceptibilities during the first hours of managing a patient suspected of a severe bacterial infection.

Clinical and microbiologic characteristics of cefotaxime-non-susceptible Enterobacteriaceae bacteremia: a case control study

Background

Cefotaxime plays an important role in the treatment of patients with bacteremia due to Enterobacteriaceae, although cefotaxime resistance is reported to be increasing in association with extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase (AmpC).

Methods

We conducted a case-control study in a Japanese university hospital between 2011 and 2012. We assessed the risk factors and clinical outcomes of bacteremia due to cefotaxime-non-susceptible Enterobacteriaceae (CTXNS-En) and analyzed the resistance mechanisms.

Results

Of 316 patients with Enterobacteriaceae bacteremia, 37 patients with bacteremia caused by CTXNS-En were matched to 74 patients who had bacteremia caused by cefotaxime-susceptible Enterobacteriaceae (CTXS-En). The most common CTXNS-En was Escherichia coli (43%), followed by Enterobacter spp. (24%) and Klebsiella spp. (22%). Independent risk factors for CTXNS-En bacteremia included previous infection or colonization of CTXNS-En, cardiac disease, the presence of intravascular catheter and prior surgery within 30 days. Patients with CTXNS-En bacteremia were less likely to receive appropriate empirical therapy and to achieve a complete response at 72 h than patients with CTXS-En bacteremia. Mortality was comparable between CTXNS-En and CTXS-En patients (5 vs. 3%). CTXNS-En isolates exhibited multidrug resistance but remained highly susceptible to amikacin and meropenem. CTX-M-type ESBLs accounted for 76% of the β-lactamase genes responsible for CTXNS E. coli and Klebsiella spp. isolates, followed by plasmid-mediated AmpC (12%). Chromosomal AmpC was responsible for 89% of CTXNS Enterobacter spp. isolates.

Conclusions

CTXNS-En isolates harboring ESBL and AmpC caused delays in appropriate therapy among bacteremic patients. Risk factors and antibiograms may improve the selection of appropriate therapy for CTXNS-En bacteremia. Prevalent mechanisms of resistance in CTXNS-En were ESBL and chromosomal AmpC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2150-6) contains supplementary material, which is available to authorized users.

Extended-spectrum β-lactamase-producing bacteria caused less than 5% of urinary tract infections in a paediatric emergency centre

AIM

The last decade has seen a significant increase in extended-spectrum β-lactamase (ESBL) secreting organisms responsible for paediatric urinary tract infections (UTIs), particularly in community-acquired infections. These expose patients to the risks of antibiotic treatment failure and renal scarring. This prospective study examined the prevalence and risk factors of febrile ESBL UTIs and their treatment in the paediatric emergency department of a university hospital.

METHODS

In this prospective observational study, all children from 0 to 16 years of age with febrile UTIs were included from May 2012 to April 2013. Cases with and without ESBL involvement were compared.

RESULTS

Of the 474 diagnosed febrile UTIs, 22 (4.6%) with a 95% confidence interval (95% CI) of 2.9-6.9 were due to an ESBL-producing organism. Escherichia coli was found in 85% of cases. Significant odds ratios (OR) for ESBL urinary tract infections were prior hospitalisation (OR 4.1, 95% CI 1.6-10.8), urinary tract abnormalities (OR 3.9, 95% CI 1.5-10.2) and previous antibiotic treatment (OR 3.1, 95% CI 1.2-8.8). All ESBL urinary tract infections had positive outcomes.

CONCLUSION

The prevalence of febrile ESBL urinary tract infections was less than 5% in a paediatric emergency department. This low rate was not high enough to justify changing our guidelines.

A Clinical Decision Tree to Predict Whether a Bacteremic Patient Is Infected With an Extended-Spectrum β-Lactamase-Producing Organism

BACKGROUND

Timely identification of extended-spectrum β-lactamase (ESBL) bacteremia can improve clinical outcomes while minimizing unnecessary use of broad-spectrum antibiotics, including carbapenems. However, most clinical microbiology laboratories currently require at least 24 additional hours from the time of microbial genus and species identification to confirm ESBL production. Our objective was to develop a user-friendly decision tree to predict which organisms are ESBL producing, to guide appropriate antibiotic therapy.

METHODS

We included patients ≥18 years of age with bacteremia due to Escherichia coli or Klebsiella species from October 2008 to March 2015 at Johns Hopkins Hospital. Isolates with ceftriaxone minimum inhibitory concentrations ≥2 µg/mL underwent ESBL confirmatory testing. Recursive partitioning was used to generate a decision tree to determine the likelihood that a bacteremic patient was infected with an ESBL producer. Discrimination of the original and cross-validated models was evaluated using receiver operating characteristic curves and by calculation of C-statistics.

RESULTS

A total of 1288 patients with bacteremia met eligibility criteria. For 194 patients (15%), bacteremia was due to a confirmed ESBL producer. The final classification tree for predicting ESBL-positive bacteremia included 5 predictors: history of ESBL colonization/infection, chronic indwelling vascular hardware, age ≥43 years, recent hospitalization in an ESBL high-burden region, and ≥6 days of antibiotic exposure in the prior 6 months. The decision tree's positive and negative predictive values were 90.8% and 91.9%, respectively.

CONCLUSIONS

Our findings suggest that a clinical decision tree can be used to estimate a bacteremic patient's likelihood of infection with ESBL-producing bacteria. Recursive partitioning offers a practical, user-friendly approach for addressing important diagnostic questions.

Unique Risks and Clinical Outcomes Associated With Extended-Spectrum β-Lactamase Enterobacteriaceae in Veterans With Spinal Cord Injury or Disorder: A Case-Case-Control Study

OBJECTIVES To describe the burden of extended-spectrum β-lactamase (ESBL) Enterobacteriaceae in veterans with spinal cord injury or disorder (SCI/D), to identify risk factors for ESBL acquisition, and to assess impact on clinical outcomes DESIGN Retrospective case-case-control study PATIENTS AND SETTING Veterans with SCI/D and utilization at a Veterans' Affairs medical center from January 1, 2012, to December 31, 2013. METHODS Patients with a positive culture for ESBL Klebsiella pneumoniae, Escherichia coli, or Proteus mirabilis were matched with patients with non-ESBL organisms by organism, facility, and level of care and to uninfected controls by facility and level of care. Inpatients were also matched by time at risk. Univariate and multivariate matched models were assessed for differences in risk factors and outcomes. RESULTS A total of 492 cases (62.6% outpatients) were matched 1:1 with each comparison group. Recent prior use of fluoroquinolones and prior use of third- and fourth-generation cephalosporins were independently associated with ESBL compared to the non-ESBL group (adjusted odds ratio [aOR], 2.61; 95% confidence interval [CI], 1.77-3.84; P<.001 for fluoroquinolones and aOR, 3.86; 95% CI, 2.06-7.25; P<.001 for third- and fourth-generation cephalosporins) and the control group (aOR, 2.10; 95% CI, 1.29-3.43; P = .003 for fluoroquinolones; and aOR, 3.31; 95% CI, 1.56-7.06; P=.002 for third- and fourth-generation cephalosporins). Although there were no differences in mortality rate, the ESBL group had a longer post-culture length of stay (LOS) than the non-ESBL group (incidence rate ratio, 1.36; 95% CI, 1.13-1.63; P=.001). CONCLUSIONS All SCI/D patients with ESBL were more likely to have had recent exposure to fluoroquinolones or third- and fourth-generation cephalosporins, and hospitalized patients were more likely to have increased post-culture LOS. Programs targeted toward reduced antibiotic use in SCI/D patients may prevent subsequent ESBL acquisition. Infect Control Hosp Epidemiol 2016;37:768-776.

The prevalence of ESBL-producing Enterobacteriaceae in a nursing home setting compared with elderly living at home: a cross-sectional comparison

Background

The aim of the study was to investigate the prevalence of faecal carriage of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae among residents living in nursing homes and to compare it with a corresponding group of elderly people living in their own homes.

Methods

A total of 160 persons participated in the study between February and April 2014, 91 were residents in nursing homes (n = 10) and the remaining 69 were elderly living in their own homes. In addition to performing faecal samples, all participants answered a standardized questionnaire regarding known risk factors for ESBL-carriage.

Results

There was no significant difference between the groups, as 10 of the 91 (11 %) residents from nursing homes were ESBL-carriers compared with 6 of 69 (8,7 %) elderly living in their own homes. There was no significant difference between the groups. The total prevalence was 10 %. A univariate analysis revealed that the only studied risk factor significantly associated with ESBL-carriage was recent foreign travel (p = 0,017). All ESBL-positive isolates were Escherichia coli and there was a high degree of co-resistance to other antibiotics. All isolates (n = 17) were susceptible to imipenem and amikacin.

Conclusion

Residents of nursing homes as well as elderly living in their own homes have high rates of faecal carriage of ESBL-producing bacteria. These findings may affect the choice of empirical antibiotic treatment of severe infections in older adults.

The antimicrobial activity of mecillinam, nitrofurantoin, temocillin and fosfomycin and comparative analysis of resistance patterns in a nationwide collection of ESBL-producing Escherichia coli in Norway 2010-2011

BACKGROUND

The prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in Norway has been steadily increasing during the last 10-15 years as part of a global pandemic. ESBL producers frequently express co-resistance to other important antimicrobial drug classes, limiting therapeutic options. This has led to regained interest in older antimicrobial agents. The aim of this study was to evaluate the antimicrobial activity of mecillinam, nitrofurantoin, temocillin and fosfomycin, as well as to perform a comparative analysis of resistance patterns in a nationwide collection of ESBL-producing E. coli.

METHODS

A nationwide collection of all 105 clinical isolates of ESBL-producing E. coli from the Norwegian Organisation for Surveillance of Antimicrobial Resistance (NORM) during 2010-2011 was analyzed. Detection and identification of ESBL-encoding genes were performed by PCR and sequencing for confirmation of ESBL variants of blaTEM and blaSHV (2010) or microarray (2011). Minimum inhibitory concentrations (MICs) or MIC correlates were determined using MIC gradient tests or VITEK 2, respectively. Comparative analysis of resistance patterns was performed.

RESULTS

All isolates were susceptible to fosfomycin, temocillin (urinary tract breakpoint) and meropenem. For mecillinam and nitrofurantoin, 6% and 9% of the isolates, respectively, were non-susceptible. A high level of susceptibility was also observed for amikacin (95%). In contrast, the non-susceptibility proportions to ampicillin (100%), cefotaxime (97%), ceftazidime (77%), aztreonam (87%), gentamicin (42%), tobramycin (52%), ciprofloxacin (76%) and trimethoprim-sulfamethoxazole (71%) were higher.

CONCLUSIONS

Overall, the in vitro susceptibility to nitrofurantoin, fosfomycin, mecillinam and temocillin was high, indicating that these drugs are good options for treating uncomplicated urinary tract infections caused by ESBL-producing E. coli.

Two-year prospective evaluation of colonization with extended-spectrum beta-lactamase-producing Enterobacteriaceae: time course and risk factors

BACKGROUND

We wanted to determine the time course of colonization with extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (EPE), sites of colonization and risk factors for prolonged colonization with EPE to obtain information for successful infection control measures.

METHODS

Rectal swab, urine, throat swab and other clinically relevant samples (wound swab, tracheal aspirate and sputum) were obtained from each participant. Sets of follow-up samples and data about potential risk factors for prolonged colonization with EPE were collected every 3 months for 2 years. Multivariate analysis using a logistic regression model was performed to identify risk factors for prolonged colonization.

RESULTS

A total of 114 patients were included in the study, 49 completed the 2-year follow-up. In all, 611 sample sets were collected, 309 (50.6%) of which were positive for ESBL. Of the positive sample sets, 90% had a rectal swab positive for ESBL, the throat swab was positive for ESBL in 17.2% of cases and urine in 36.2% of cases; 10% of positive sample sets had negative rectal swabs with EPE isolated from other sites, most often from urine. Immobility was found to be associated with prolonged carriage (≥ 12 months) of EPE. After 2 years, 15/49 (30.6%) patients were colonized with EPE. In 12/49 (24.5%) patients, transient negativity was observed.

CONCLUSIONS

We found that prolonged colonization with EPE was common, especially in bedridden patients. Transient negative samples were often observed during the course of colonization. In some patients, urine can be the only positive site from which EPE are isolated.