β-Lactam allergy delabeling is safe and saves costs in Primary Care

OBJECTIVE

To determine whether the β-lactam allergy delabeling was safe and cost-saving in Primary Care (PC) patients.

DESIGN

We have conducted a retrospective chart review of PC patients with β-lactam allergy label evaluated in our Allergy Unit between 2017 and 2022. SITE: Allergy Department. Hospital Virgen del Rocio (Sevilla).

PARTICIPANTS

A total of 391 patients labeled for β-lactam allergy in PC were studied.

MAIN MEASUREMENTS

(a) Outcome evaluation of a β-lactam allergy delabeling procedure. (b) A ratio between the total e-prescribed antibiotic cost and the number of treatment days (the experimental daily antibiotic cost or EDAC) before and after delabeling was analyzed in delabeled and truly allergic patients.

RESULTS

The results of skin testing were positive in 9.2% of the reported cases (36 of 391 patients). The reactions to oral provocation challenge (OPC) occurred in 2.14% of the patients who underwent negative skin testing to offending β-lactam (in 15 of 699 OPC). A total of 307 patients (78.5%) were delabeled; 70 (17.9%) had a β-lactam selective response and 14 (3.59%) reacted to both penicillin and cephalosporin. The EDAC before and after the procedure in delabeled patients was significantly lower (0.88 € vs 0.62 €, p<10-3), than that observed in truly allergic group (0.87 € vs. 0.76 €, p=not significant).

CONCLUSION

To delabel β-lactam allergy in Primary Care patients is safe in most patients, cost-saving in antibioticotherapy, and allows identify the main clinical β-lactam allergy phenotypes that benefit from this procedure.

Efficacy and safety of an early oral switch in low-risk Staphylococcus aureus bloodstream infection (SABATO): an international, open-label, parallel-group, randomised, controlled, non-inferiority trial

BACKGROUND

Staphylococcus aureus bloodstream infection is treated with at least 14 days of intravenous antimicrobials. We assessed the efficacy and safety of an early switch to oral therapy in patients at low risk for complications related to S aureus bloodstream infection.

METHODS

In this international, open-label, randomised, controlled, non-inferiority trial done in 31 tertiary care hospitals in Germany, France, the Netherlands, and Spain, adult patients with low-risk S aureus bloodstream infection were randomly assigned after 5-7 days of intravenous antimicrobial therapy to oral antimicrobial therapy or to continue intravenous standard therapy. Randomisation was done via a central web-based system, using permuted blocks of varying length, and stratified by study centre. The main exclusion criteria were signs and symptoms of complicated S aureus bloodstream infection, non-removable foreign devices, and severe comorbidity. The composite primary endpoint was the occurrence of any complication related to S aureus bloodstream infection (relapsing S aureus bloodstream infection, deep-seated infection, and mortality attributable to infection) within 90 days, assessed in the intention-to-treat population by clinical assessors who were masked to treatment assignment. Adverse events were assessed in all participants who received at least one dose of study medication (safety population). Due to slow recruitment, the scientific advisory committee decided on Jan 15, 2018, to stop the trial after 215 participants were randomly assigned (planned sample size was 430 participants) and to convert the planned interim analysis into the final analysis. The decision was taken without knowledge of outcome data, at a time when 126 participants were enrolled. The new sample size accommodated a non-inferiority margin of 10%; to claim non-inferiority, the upper bound of the 95% CI for the treatment difference (stratified by centre) had to be below 10 percentage points. The trial is closed to recruitment and is registered with ClinicalTrials.gov (NCT01792804), the German Clinical trials register (DRKS00004741), and EudraCT (2013-000577-77).

FINDINGS

Of 5063 patients with S aureus bloodstream infection assessed for eligibility, 213 were randomly assigned to switch to oral therapy (n=108) or to continue intravenous therapy (n=105). Mean age was 63·5 (SD 17·2) years and 148 (69%) participants were male and 65 (31%) were female. In the oral switch group, 14 (13%) participants met the primary endpoint versus 13 (12%) in the intravenous group, with a treatment difference of 0·7 percentage points (95% CI -7·8 to 9·1; p=0·013). In the oral switch group, 36 (34%) of 107 participants in the safety population had at least one serious adverse event compared with 27 (26%) of 103 participants in the intravenous group (p=0·29).

INTERPRETATION

Oral switch antimicrobial therapy was non-inferior to intravenous standard therapy in participants with low-risk S aureus bloodstream infection. However, it is necessary to carefully assess patients for signs and symptoms of complicated S aureus bloodstream infection at the time of presentation and thereafter before considering early oral switch therapy.

FUNDING

Deutsche Forschungsgemeinschaft.

TRANSLATIONS

For the German, Spanish, French and Dutch translations of the abstract see Supplementary Materials section.

Antimicrobial Stewardship in the Emergency Department Observation Unit: Definition of a New Indicator and Evaluation of Antimicrobial Use and Clinical Outcomes

We aimed to define a novel indicator for monitoring antimicrobial use specifically in the Emergency Department Observation Unit (EDOU) and to assess the long-term impact of an institutional education-based antimicrobial stewardship program (ASP) on the antimicrobial prescribing pattern and clinical outcomes in this setting. A quasi-experimental interrupted time-series study was performed from 2011 to 2022. An educational ASP was implemented at the EDOU in 2015. To estimate changes in antimicrobial use, we designed an indicator adjusted for patients at risk of antimicrobial prescribing: defined daily doses (DDDs) per 100 patients transferred from the Emergency Department to the Observation Unit (TOs) per quarter. The number of bloodstream infections (BSIs) and the crude all-cause 14-day mortality were assessed as clinical outcomes. Antimicrobial use showed a sustained reduction with a trend change of -1.17 DDD per 100 TO and a relative effect of -45.6% (CI95% -64.5 to -26.7), particularly relevant for meropenem and piperacillin-tazobactam, with relative effects of -80.4% (-115.0 to -45.7) and -67.9% (-93.9 to -41.9), respectively. The incidence density of all BSIs increased significantly during the ASP period, with a relative effect of 123.2% (41.3 to 284.7). The mortality rate remained low and stable throughout the study period, with an absolute effect of -0.7% (-16.0 to 14.7). The regular monitoring of antimicrobial use in the EDOU by using this new quantitative indicator was useful to demonstrate that an institutional education-based ASP successfully achieved a long-term reduction in overall antimicrobial use, with a low and steady BSI mortality rate.

C-terminal deletion of RelA protein is suggested as a possible cause of infective endocarditis recurrence with Enterococcus faecium

Infective endocarditis (IE) caused by Enterococcus spp. represents the third most common cause of IE, with high rates of relapse compared with other bacteria. Interestingly, late relapses (>6 months) have only been described in Enterococcus faecalis, but here we describe the first reported IE relapse with Enterococcus faecium more than a year (17 months) after the initial endocarditis episode. Firstly, by multi locus sequence typing (MLST), we demonstrated that both isolates (EF646 and EF641) belong to the same sequence type (ST117). Considering that EF641 was able to overcome starvation and antibiotic treatment conditions surviving for a long period of time, we performed bioinformatic analysis in identifying potential genes involved in virulence and stringent response. Our results showed a 13-nucleotide duplication (positions 1638-1650) in the gene relA, resulting in a premature stop codon, with a loss of 167 amino acids from the C-terminal domains of the RelA enzyme. RelA mediates the stringent response in bacteria, modulating levels of the alarmone guanosine tetraphosphate (ppGpp). The relA mutant (EF641) was associated with lower growth capacity, the presence of small colony variants, and higher capacity to produce biofilms (compared with the strain EF646), but without differences in antimicrobial susceptibility patterns according to standard procedures during planktonic growth. Instead, EF641 demonstrated tolerance to high doses of teicoplanin when growing in a biofilm. We conclude that all these events would be closely related to the long-term survival of the E. faecium and the late relapse of the IE. These data represent the first clinical evidence of mutations in the stringent response (relA gene) related with E. faecium IE relapse.

Implementation of a PCR-based strategy to control an outbreak by Serratia marcescens in a Neonatal Intensive Care Unit

OBJECTIVES

To evaluate the clinical and epidemiological impact of a new molecular surveillance strategy based on qPCR to control an outbreak by Serratia marcescens in a Neonatal Intensive Care Unit (NICU).

METHODS

We design a specific qPCR for the detection of S. marcescens in rectal swabs of patients admitted to a NICU. We divided the surveillance study into two periods: (a) the pre-PCR, from the outbreak declaration to the qPCR introduction, and (b) the PCR period, from the introduction of the qPCR until the outbreak was solved. In all cases, S. marcescens isolates were recovered and their clonal relationship was analysed by PFGE. Control measures were implemented during the outbreak. Finally, the number of bloodstream infections (BSI) was investigated in order to evaluate the clinical impact of this molecular strategy.

RESULTS

Nineteen patients colonized/infected by S. marcescens were detected in the pre-PCR period (October 2020-April 2021). On the contrary, after the PCR implementation, 16 new patients were detected. The PFGE revealed 24 different pulsotypes belonging to 7 different clonal groups, that were not overlapping at the same time. Regarding the clinical impact, 18 months after the qPCR implementation, no more outbreaks by S. marcescens have been declared in the NICU of our hospital, and only 1 episode of BSI has occurred, compared with 11 BSI episodes declared previously to the outbreak control.

CONCLUSIONS

The implementation of this qPCR strategy has proved to be a useful tool to control the nosocomial spread of S. marcescens in the NICU.

Recommendations for the prevention of healthcare-associated infections in nursing homes

Nursing homes (NH) conceptually should look as much like a home as possible. However NH have unquestionable similarities with a nosocomium as they are places where many patients with underlying diseases and comorbidities accumulate. There is evidence of transmission of microorganisms between residents and between residents and caregivers. We have not found any recommendations specifically aimed at the prevention of nosocomial infections in NH by the major Public Health Agencies and, therefore, the Health Sciences Foundation (Fundación de Ciencias de la Salud) has convened a series of experts and 14 Spanish scientific societies to discuss recommendations that could guide NH personnel in establishing written programs for the control and reduction of these infections. The present document is the result of these deliberations and contains suggestions for establishing such control programs on a voluntary and flexible basis in NH. We also hope that the document can help the health authorities to encourage this control activity in the different territorial areas of Spain. In our opinion, it is necessary to draw up a written plan and establish the figure of a coordinator or person responsible for implementing these projects. The document includes measures to be implemented and ways of quantifying the reality of different problems and of monitoring the impact of the measures established.

Safety of early oral ambulatory treatment of adult patients with bloodstream infections discharged from the emergency department

This study evaluates the safety of early oral ambulatory treatment of adult patients diagnosed with bacteremia after their discharge from the emergency department. A cohort of 206 febrile ambulatory patients was assessed. Bacteremic low-risk patients were recommended an oral treatment and were compared with matched febrile non-bacteremic outpatients. Rates of 14-day mortality and unplanned re-consultations were similar and below 5% in both cohorts, highlighting the safety of oral therapy of low-risk bacteremia, even from its onset.

BIChromET: A Chromogenic Culture Medium for Detection of Piperacillin/Tazobactam and Cefepime Resistance in Pseudomonas aeruginosa

OBJECTIVES

The BIChromET selective medium for detecting piperacillin-tazobactam (TZP) and cefepime (FEP) resistant Pseudomonas aeruginosa was developed.

METHODS

The performance of this medium was first evaluated using a collection of 100 P. aeruginosa clinical strains (70 TZP-susceptible, 30 TZP-resistant, 58 FEP-susceptible, and 42 FEP-resistant). Then, we performed clinical validation by testing 173 respiratory clinical samples.

RESULTS

The BIChromET medium showed excellent sensitivity (TZP (avg. 96.7%); FEP (avg. 92.7%)) and specificity (TZP (avg. 98.9%); FEP (avg. 98%)) in distinguishing the detection limit ranging from 104 to 108 CFU/mL. Then, testing the bronchoalveolar lavage (BAL) and tracheobronchial aspirate (TBA) clinical specimens (N = 173) revealed the excellent performance of the medium with P. aeruginosa, showing 100% and 92.6% of categorical agreements with the results obtained via the broth microdilution methods (BMD) for TZP and FEP, respectively.

CONCLUSION

This medium allows for easy and accurate detection of TZP/FEP-resistant isolates regardless of their resistance mechanisms.

Role of blaTEM and OmpC in the piperacillin-tazobactam resistance evolution by E. coli in patients with complicated intra-abdominal infection

Piperacillin-tazobactam resistance (P/T-R) is increasingly reported among Escherichia coli isolates. Although in vitro experiments have suggested that blaTEM gene plays a key role in the P/T-R acquisition, no clinical in vivo study has yet confirmed the role of blaTEM or other genes. Therefore, we aimed to identify the mechanisms underlying P/T-R by following up patients with E. coli complicated intra-abdominal infections (cIAI) who experienced P/T treatment failure. Four pairs of strains, clonally related from four patients, were isolated both before and after treatment with P/T dosed at 4 g/0.5 g intravenously. The P/T MIC was tested using broth microdilution, and β-lactamase activity was determined in these isolates. Whole-genome sequencing (WGS) was performed to decipher the role of blaTEM and other genes associated with P/T-R. Changes in the outer membrane protein (OMP) profile were analyzed using SDS-PAGE, and blaTEM and ompC transcription levels were measured by RT-qPCR. In addition, in vitro competition fitness was performed between each pairs of strains (P/T-susceptible vs. P/T-resistant). We found a higher copy number of blaTEM gene in P/T-R isolates, generated by three different genetic events: (1) IS26-mediated duplication of the blaTEM gene, (2) generation of a small multicopy plasmid (ColE-like) carrying blaTEM, and (3) adaptive evolution via reduction of plasmid size, leading to a higher plasmid copy number. Moreover, two P/T-R strains showed reduced expression of OmpC. This study describes the mechanisms involved in the acquisition of P/T-R by E. coli in patients with cIAI. The understanding of P/T-R evolution is crucial for effectively treating infected patients and preventing the spread of resistant microorganisms.

Analysis of the appropriateness of antibiotic prophylaxis in surgical procedures in Spain. Protocol for the "ProA-Q" study

Surgical antibiotic prophylaxis is one of the most useful measures to prevent surgical wound infection.

OBJECTIVE

The aim of this project is to evaluate the appropriateness of the use of antibiotic prophylaxis in surgical procedures performed in Spanish hospitals, both globally and according to the type of surgery performed.

METHOD

For this purpose, an observational, retrospective, cross-sectional and multicenter study has been designed to collect all the variables that allow the evaluation of the appropriateness of surgical antibiotic prophylaxis by comparing the prescribed treatment, the recommendations included in the local guidelines and the consensus document of the Spanish Society of Infectious Diseases and Clinical Microbiology and the Spanish Association of Surgeons. Indication, choice of antimicrobial, dose, route and duration of administration, timing, re-dosing and duration of the prophylaxis will be taken into account. The sample will consist of patients who underwent scheduled or emergency surgery, either as inpatients or outpatients, in hospitals in Spain. A sample size of 2,335 patients has been established to estimate, with 95% confidence and 80% power, a percentage of appropriateness that is expected to be around 70%. Differences between variables will be analyzed using Student's t-test, Mann-Whitney U test, Chi-square test, or Fisher's test, as appropriate. The degree of agreement between the antibiotic prophylaxis recommended by the guidelines of the different hospitals and that recommended in the literature will be analyzed by calculating the Cohen's kappa indicator. Binary logistic regression analysis using generalized linear mixed models will be performed to identify possible factors associated with differences in the appropriateness of antibiotic prophylaxis.

DISCUSSION

The results of this clinical study will allow us to focus on specific surgical areas with higher rates of inappropriateness, identify key points of action and guide future strategies for antimicrobial stewardship programs in the area of antibiotic prophylaxis.

[Translated article] Analysis of the appropriateness of antibiotic prophylaxis in surgical procedures in Spain. Protocol for the "ProA-Q" study

Surgical antibiotic prophylaxis is one of the most useful measures to prevent surgical wound infection.

OBJECTIVE

The aim of this project is to evaluate the appropriateness of the use of antibiotic prophylaxis in surgical procedures performed in Spanish hospitals, both globally and according to the type of surgery performed.

METHOD

For this purpose, an observational, retrospective, cross-sectional, and multicentre study has been designed to collect all the variables that allow the evaluation of the appropriateness of surgical antibiotic prophylaxis by comparing the prescribed treatment, the recommendations included in the local guidelines, and the consensus document of the Spanish Society of Infectious Diseases and Clinical Microbiology and the Spanish Association of Surgeons. Indication, choice of antimicrobial, dose, route and duration of administration, timing, re-dosing, and duration of the prophylaxis will be taken into account. The sample will consist of patients who underwent scheduled or emergency surgery, either as inpatients or outpatients, in hospitals in Spain. A sample size of 2335 patients has been established to estimate, with 95% confidence and 80% power, a percentage of appropriateness that is expected to be around 70%. Differences between variables will be analysed using Student's t-test, Mann-Whitney U test, Chi-square test, or Fisher's test, as appropriate. The degree of agreement between the antibiotic prophylaxis recommended by the guidelines of the different hospitals and that recommended in the literature will be analysed by calculating the Cohen's kappa indicator. Binary logistic regression analysis using generalised linear mixed models will be performed to identify possible factors associated with differences in the appropriateness of antibiotic prophylaxis.

DISCUSSION

The results of this clinical study will allow us to focus on specific surgical areas with higher rates of inappropriateness, identify key points of action and guide future strategies for antimicrobial stewardship programs in the area of antibiotic prophylaxis.

Post-mortem findings in Spanish patients with COVID-19; a special focus on superinfections

Introduction

Whole-body autopsies may be crucial to understand coronavirus disease 2019 (COVID-19) pathophysiology. We aimed to analyze pathological findings in a large series of full-body autopsies, with a special focus on superinfections.

Methods

This was a prospective multicenter study that included 70 COVID-19 autopsies performed between April 2020 and February 2021. Epidemiological, clinical and pathological information was collected using a standardized case report form.

Results

Median (IQR) age was 70 (range 63.75-74.25) years and 76% of cases were males. Most patients (90%,) had at least one comorbidity prior to COVID-19 diagnosis, with vascular risk factors being the most frequent. Infectious complications were developed by 65.71% of the patients during their follow-up. Mechanical ventilation was required in most patients (75.71%) and was mainly invasive. In multivariate analyses, length of hospital stay and invasive mechanical ventilation were significantly associated with infections (p = 0.036 and p = 0.013, respectively). Necropsy findings revealed diffuse alveolar damage in the lungs, left ventricular hypertrophy in the heart, liver steatosis and pre-infection arteriosclerosis in the heart and kidneys.

Conclusion

Our study confirms the main necropsy histopathological findings attributed to COVID-19 in a large patient series, while underlining the importance of both comorbid conditions and superinfections in the pathology.

Lipid signatures of West Nile virus infection unveil alterations of sphingolipid metabolism providing novel biomarkers

West Nile virus (WNV) is a neurotropic flavivirus transmitted by the bites of infected mosquitoes. Severe forms of West Nile disease (WND) can curse with meningitis, encephalitis or acute flaccid paralysis. A better understanding of the physiopathology associated with disease progression is mandatory to find biomarkers and effective therapies. In this scenario, blood derivatives (plasma and serum) constitute the more commonly used biofluids due to its ease of collection and high value for diagnostic purposes. Therefore, the potential impact of this virus in the circulating lipidome was addressed combining the analysis of samples from experimentally infected mice and naturally WND patients. Our results unveil dynamic alterations in the lipidome that define specific metabolic fingerprints of different infection stages. Concomitant with neuroinvasion in mice, the lipid landscape was dominated by a metabolic reprograming that resulted in significant elevations of circulating sphingolipids (ceramides, dihydroceramides and dihydrosphingomyelins), phosphatidylethanolamines and triacylglycerols. Remarkably, patients suffering from WND also displayed an elevation of ceramides, dihydroceramides, lactosylceramides and monoacylglycerols in their sera. The dysregulation of sphingolipid metabolism by WNV may provide new therapeutic opportunities and supports the potential of certain lipids as novel peripheral biomarkers of WND progression.

Application of new indicators to assess the quality of antimicrobial use in Intensive Care Units

We explored the feasibility of a bundle of indicators aimed at assessing the quality of antimicrobial use in intensive care units (ICUs) through an observational prospective study spanning 12 quarters (January 2019-December 2021) in a 1,290-bed teaching hospital in Spain. Members of the ASP team selected the indicators to analyze the quality of antimicrobial use based on consumption data from a list proposed in a previous study. Antimicrobial use in the ICU was measured as defined daily doses (DDD) per 100 occupied bed days. Trends and points of change were analyzed with segmented regression. Intravenous macrolides/intravenous respiratory fluoroquinolones ratio presented a non-significant progressive increase in the ICU of 11.14% per quarter, probably related to the prioritization of the use of macrolides in serious community-acquired pneumonia and the COVID-19 pandemic. A remarkable upward trend of 2.5% per quarter was detected in the anti-methicillin-susceptible Staphylococcus aureus/anti-methicillin-resistant S. aureus agents ratio in the ICU, which could be explained by the low prevalence of methicillin-resistant S. aureus in our center. Patterns of amoxicillin-clavulanic acid/piperacillin-tazobactam ratio and the diversification of anti-pseudomonal beta-lactams showed an increment in its use in that period. The use of these novel indicators provides additional information to the current analysis of DDD. Its implementation is feasible and has led to the detection of patterns that agree with local guidelines and cumulative antibiogram reports and foster targeted improvement actions within antimicrobial stewardship programs.

High-level delafloxacin resistance through the combination of two different mechanisms in Staphylococcus aureus

Delafloxacin is a new fluoroquinolone indicated for the treatment of complicated bacterial skin infections caused by Staphylococcus aureus. In spite of its recent approbation by the FDA, the emergence of S. aureus-resistant strains has been reported. Thus, we aimed to study the activity of delafloxacin against a collection of S. aureus and to determine the mechanisms of resistance. The activity of delafloxacin was measured in 59 S. aureus clinical isolates (MRSA=40; MSSA=19). In those isolates resistant to delafloxacin, whole genome sequencing (WGS) was performed. The MIC₅₀ and MIC₉₀ were higher in MRSA (0.19 mg/L and 0.75 mg/L, respectively) than in MSSA (0.008 mg/L and 0.25 mg/L, respectively). Furthermore, 10 S. aureus clinical isolates (16.9%) were categorized as resistant to delafloxacin. Regarding the WGS data, several mutations were found in the Quinolone Resistance-Determining Regions (QRDR). Nevertheless, a mutation in the same position (E84K and E84V) of the topoisomerase IV (ParC) was exclusively found in the 4 high-level delafloxacin-resistant isolates. Interestingly, we also found a plasmid-encoded qacC gene (efflux pump) harbored by the isolate with the highest delafloxacin MIC value (32 mg/L). The use of a wide-spectrum efflux pump inhibitor revealed an important contribution of this system to the acquisition of delafloxacin resistance. In conclusion, delafloxacin has activity against S. aureus, including MRSA. However, in this study, we showed that mutations in position 84 of ParC and the acquisition of QacC efflux pump are key factors for the resistance development in S. aureus.

Evaluation of the MDR Direct Flow Chip Kit for the Detection of Multiple Antimicrobial Resistance Determinants

The objective of this study was to evaluate the accuracy of the MDR Direct Flow Chip Kit for the detection of antimicrobial resistance (AMR) determinants from bacterial colonies. Ninety-two clinical isolates with known AMR determinants genotypically characterized were used. The MDR Direct Flow Chip Kit is a microarray-based assay that included 55 AMR determinants for beta-lactams (23), quinolones (13), aminoglycosides (5), macrolides (5), sulfonamides (3), colistin (2), vancomycin (2), chloramphenicol (1), and linezolid (1). The MDR Direct Flow Chip Kit correctly detects 52 of 53 AMR determinants tested. The cfr gene (linezolid resistance) was not detected. The global sensibility, specificity, positive predictive value, and the negative predictive value calculated were 98%, 100%, 100%, and 97%. The Cohen's Kappa coefficient calculated was 0.97 [95% Confidence Interval (0.90-1.03)]. In conclusion, the MDR Direct Flow Chip is an accurate assay for the detection of multiple AMR determinants in one simple reaction.

Clinical and Ecological Impact of an Educational Program to Optimize Antibiotic Treatments in Nursing Homes (PROA-SENIOR): A Cluster, Randomized, Controlled Trial and Interrupted Time-Series Analysis

BACKGROUND

Antimicrobial stewardship programs (ASPs) are recommended in nursing homes (NHs), although data are limited. We aimed to determine the clinical and ecological impact of an ASP for NHs.

METHODS

We performed a cluster, randomized, controlled trial and a before-after study with interrupted time-series analyses in 14 NHs for 30 consecutive months from July 2018 to December 2020 in Andalusia, Spain. Seven facilities implemented an ASP with a bundle of 5 educational measures (general ASP) and 7 added 1-to-1 educational interviews (experimental ASP). The primary outcome was the overall use of antimicrobials, calculated monthly as defined daily doses (DDD) per 1000 resident days (DRD).

RESULTS

The total mean antimicrobial consumption decreased by 31.2% (-16.72 DRD; P = .045) with respect to the preintervention period; the overall use of quinolones and amoxicillin-clavulanic acid dropped by 52.2% (P = .001) and 42.5% (P = .006), respectively; and the overall prevalence of multidrug-resistant organisms (MDROs) decreased from 24.7% to 17.4% (P = .012). During the intervention period, 12.5 educational interviews per doctor were performed in the experimental ASP group; no differences were found in the total mean antimicrobial use between groups (-14.62 DRD; P = .25). Two unexpected coronavirus disease 2019 waves affected the centers increasing the overall mean use of antimicrobials by 40% (51.56 DRD; P < .0001).

CONCLUSIONS

This study suggests that an ASP for NHs appears to be associated with a decrease in total consumption of antimicrobials and prevalence of MDROs. This trial did not find benefits associated with educational interviews, probably due to the coronavirus disease 2019 pandemic. Clinical Trials Registration. NCT03543605.

Rapid Detection of Piperacillin-Tazobactam Resistance in Klebsiella pneumoniae and Escherichia coli

Rapid determination of susceptibility to piperacillin-tazobactam (TZP) is very important since the development of antibiotic resistance and inadequate treatment could increase the risk of clinical failure in infected patients, especially if such resistance is unknown to the clinician. Therefore, based on color change from orange to yellow of phenol red due to glucose metabolism (bacterial growth) in the presence of an adequate concentration of TZP (10 mg/L piperacillin and 5 mg/L tazobactam), the RapidTZP test has been developed to detect TZP resistance in Escherichia coli and Klebsiella pneumoniae isolates in a maximum of 3 h. A total of 140 isolates, 43 of E. coli and 97 of K. pneumoniae, were used to evaluate the performance of the test, 60 being resistant to TZP. The sensitivity and specificity of the test were 98.24% and 100%, respectively. Additionally, the RapidTZP test was validated by a pellet obtained directly from blood culture bottles. A total of 37 positive blood cultures for E. coli and 43 for K. pneumoniae were used for validation, 8 of them resistant to TZP. The sensitivity and specificity shown in the evaluation were 100% for both parameters. This new test is easy, fast, and accurate, providing results in 3 h. IMPORTANCE TZP is an antibiotic widely used for the empirical treatment of severe infections such as bloodstream infections. However, resistance to TZP in K. pneumoniae and E. coli has been increasing in the last few years. Thus, rapid detection of TZP resistance is critical to optimize the empirical treatment of patients with severe infections. In this study, we developed and evaluated a rapid test (RapidTZP) for the detection of TZP resistance in K. pneumoniae and E. coli directly from positive hemocultures in just 3 h. This rapid test has been validated on 138 K. pneumoniae and E. coli clinical isolates directly from agar plates and 80 K. pneumoniae and E. coli isolates causing bloodstream infections. The results demonstrate that the RapidTZP test has great clinical potential to optimize the empirical treatment of patients with bloodstream infections.

In Vitro and In Vivo Virulence Study of Listeria monocytogenes Isolated from the Andalusian Outbreak in 2019

In 2019, the biggest listeriosis outbreak by Listeria monocytogenes (Lm) in the South of Spain was reported, resulting in the death of three patients from 207 confirmed cases. One strain, belonging to clonal complex 388 (Lm CC388), has been isolated. We aimed to determine the Lm CC388 virulence in comparison with other highly virulent clones such as Lm CC1 and Lm CC4, in vitro and in vivo. Four L. monocytogenes strains (Lm CC388, Lm CC1, Lm CC4 and ATCC 19115) were used. Attachment to human lung epithelial cells (A549 cells) by these strains was characterized by adherence and invasion assays. Their cytotoxicities to A549 cells were evaluated by determining the cells viability. Their hemolysis activity was determined also. A murine intravenous infection model using these was performed to determine the concentration of bacteria in tissues and blood. Lm CC388 interaction with A549 cells is non-significantly higher than that of ATCC 19115 and Lm CC1, and lower than that of Lm CC4. Lm CC388 cytotoxicity is higher than that of ATCC 19115 and Lm CC1, and lower than that of Lm CC4. Moreover, Lm CC388 hemolysis activity is lower than that of the Lm CC4 strain, and higher than that of Lm CC1. Finally, in the murine intravenous infection model by Lm CC388, higher bacterial loads in tissues and at similar levels of Lm CC4 were observed. Although a lower rate of mortality of patients during the listeriosis outbreak in Spain in 2019 has been reported, the Lm CC388 strain has shown a greater or similar pathogenicity level in vitro and in an animal model, like Lm CC1 and Lm CC4.

Duration of antibiotic treatment for Gram-negative bacteremia - Systematic review and individual participant data (IPD) meta-analysis

BACKGROUND

We aim to compare the effect of short versus long treatment duration in Gram-negative bacteremia on all-cause mortality in pre-specified sub-groups.

METHODS

Individual participant data meta-analysis of randomized controlled trials (RCTs) comparing short (≤7) versus longer (>7 days) antibiotic treatment for Gram-negative bacteremia. Participants were adults (≥18 years), with Gram-negative bacteremia during hospital stay. We searched PubMed, Cochrane Central Register of Controlled Trials, and Web of Science to identify trials conducted up to May 2022. Primary outcome was 90-day all-cause mortality. Secondary outcomes were 30-day mortality, relapse of bacteremia, length of hospital stay, readmission, local or distant infection complications, adverse events, and resistance emergence.Outcomes were assessed in pre-specified subgroups: women vs men; non-urinary vs urinary source; presence vs absence of hypotension on initial presentation; immunocompromised patients versus non-immunocompromised patients, and age (above/below 65). Fixed-effect meta-analysis model was used to estimate pooled odds ratio (OR) and 95% confidence interval (CI). All three trials had low risk of bias for allocation generation and concealment.

FINDINGS

Three RCTs (1186 patients) were included; 1121 with enterobacterales bacteremia. No significant difference in mortality was demonstrated between 7- and 14-days treatment (90-day mortality: OR 1.08, 95% CI 0.73-1.58; 30-day mortality: 1.08, 0.62-1.91). Relapse (1.00, 0.50-1.97); length of hospital stay (P = 0.78); readmission (0.96, 0.80-1.22); and infection complications (local: 1.62 0.76-3.47; distant: 2.00, 0.18-22.08), were without significant difference, and so were adverse events or resistance emergence.No significant difference in clinical outcomes between 7 and 14 days of antibiotics was demonstrated in the subgroups of gender, age, hemodynamic status, immune status, and source of infection.

INTERPRETATION

For patients hemodynamically stable and afebrile at 48 h prior to discontinuation, seven days of antibiotic therapy for enterobacterales bacteremia result in similar outcomes as 14 days, in terms of mortality, relapse, length of hospital stay, complications of infection, resistance emergence, and adverse events. These results apply for any adult age group, gender, source of infection, immune status, and hemodynamic status on presentation.

FUNDING

There was no funding source for this study.

Study protocol for a randomized clinical trial to assess 7 versus 14-days of treatment for Pseudomonas aeruginosa bloodstream infections (SHORTEN-2 trial)

BACKGROUND

Research priorities in Antimicrobial Stewardship (AMS) have rapidly evolved in the last decade. The need for a more efficient use of antimicrobials have fueled plenty of studies to define the optimal duration for antibiotic treatments, and yet, there still are large areas of uncertainty in common clinical scenarios. Pseudomonas aeruginosa has been pointed as a priority for clinical research, but it has been unattended by most randomized trials tackling the effectiveness of short treatments. The study protocol of the SHORTEN-2 trial is presented as a practical example of new ways to approach common obstacles for clinical research in AMS.

OBJECTIVE

To determine whether a 7-day course of antibiotics is superior to 14-day schemes for treating bloodstream infections by P. aeruginosa (BSI-PA).

METHODS

A superiority, open-label, randomized controlled trial will be performed across 30 Spanish hospitals. Adult patients with uncomplicated BSI-PA will be randomized to receive a 7 versus 14-day course of any active antibiotic. The primary endpoint will be the probability for the 7-day group of achieving better outcomes than the control group, assessing altogether clinical effectiveness, severe adverse events, and antibiotic exposure through a DOOR/RADAR analysis. Main secondary endpoints include treatment failure, BSI-PA relapses, and mortality. A superiority design was set for the primary endpoint and non-inferiority for treatment failure, resulting in a sample size of 304 patients.

CONCLUSIONS

SHORTEN-2 trial aligns with some of the priorities for clinical research in AMS. The implementation of several methodological innovations allowed overcoming common obstacles, like feasible sample sizes or measuring the clinical impact and unintended effects.

TRIAL REGISTRATION

EudraCt: 2021-003847-10; ClinicalTrials.gov: NCT05210439.

A step forward in antibiotic use and resistance monitoring: a quarterly surveillance system pilot in 11 European Union/European Economic Area countries, September 2017 to May 2020

BackgroundSurveillance of antimicrobial resistance (AMR) and antimicrobial use (AMU) in Europe is currently annual.AimTo study the feasibility and scalability of a quarterly AMR/AMU surveillance system in the European Union/European Economic Area (EU/EEA).MethodsWe conducted a longitudinal study within the scope of the EU-JAMRAI project. Seventeen partners from 11 EU/EEA countries prospectively collected 41 AMU and AMR indicators quarterly from September 2017 to May 2020 for the hospital sector (HS) and primary care (PC). Descriptive statistics and coefficients of variation (CV) analysis were performed.ResultsData from 8 million hospital stays and 45 million inhabitants per quarter were collected at national (n = 4), regional (n = 6) and local (n = 7) levels. Of all partners, five were able to provide data within 3 months after each preceding quarter, and eight within 3-6 months. A high variability in AMU was found between partners. Colistin was the antibiotic that showed the highest CV in HS (1.40; p < 0.0001). Extended-spectrum beta-lactamase-producing Escherichia coli presented the highest incidence in HS (0.568 ± 0.045 cases/1,000 bed-days per quarter), whereas ciprofloxacin-resistant E. coli showed the highest incidence in PC (0.448 ± 0.027 cases/1,000 inhabitants per quarter). Barriers and needs for implementation were identified.ConclusionThis pilot study could be a first step towards the development of a quarterly surveillance system for AMU and AMR in both HS and PC in the EU/EEA. However, committed institutional support, dedicated human resources, coordination of data sources, homogeneous indicators and modern integrated IT systems are needed first to implement a sustainable quarterly surveillance system.

IgM-enriched immunoglobulin improves colistin efficacy in a pneumonia model by Pseudomonas aeruginosa

Using polyclonal IgM-enriched immunoglobulin (IgM-IG) as adjuvant therapy to colistin appears useful in the treatment of pneumonia caused by multidrug-resistant strains of P. aeruginosa.

We evaluated the efficacy of ceftazidime or colistin in combination with polyclonal IgM-enriched immunoglobulin (IgM-IG), in an experimental pneumonia model (C57BL/6J male mice) using two multidrug-resistant Pseudomonas aeruginosa strains, both ceftazidime-susceptible and one colistin-resistant. Pharmacodynamically optimised antimicrobials were administered for 72 h, and intravenous IgM-IG was given as a single dose. Bacterial tissues count and the mortality were analysed. Ceftazidime was more effective than colistin for both strains. In mice infected with the colistin-susceptible strain, ceftazidime reduced the bacterial concentration in the lungs and blood (−2.42 and −3.87 log₁₀ CFU/ml) compared with colistin (−0.55 and −1.23 log₁₀ CFU/ml, respectively) and with the controls. Colistin plus IgM-IG reduced the bacterial lung concentrations of both colistin-susceptible and resistant strains (−2.91 and −1.73 log₁₀ CFU/g, respectively) and the bacteraemia rate of the colistin-resistant strain (−44%). These results suggest that IgM-IG might be useful as an adjuvant to colistin in the treatment of pneumonia caused by multidrug-resistant P. aeruginosa.

Has the COVID-19 pandemic wiped out the seasonality of outpatient antibiotic use and influenza activity? A time-series analysis from 2014 to 2021

OBJECTIVE

To assess the influence of the emergence of severe acute respiratory syndrome coronavirus 2 and the implementation of public health measures on the seasonality of outpatient antibiotic use and their possible association with the incidence of influenza.

METHODS

We performed a time-series ecological study in 1516 primary care centres of Andalusia, Spain, comparing the coronavirus disease 2019 period (April 2020 to March 2021) with the 6 previous years. We assessed the number of packs and defined daily doses per 1000 inhabitants of antibacterials and key antibiotics commonly used for acute respiratory tract infections and the number of influenza-positive cases per 100 000 inhabitants. We calculated the correlation between variables and analyzed the seasonal patterns and differences in quarterly antibiotic use.

RESULTS

For all quarters, a significant correlation was observed between influenza activity and antibiotic use (Spearman's r = 0.94; p < 0.001). Before the pandemic period, both variables presented similar seasonal patterns. After the start of the pandemic, influenza activity was suppressed and the pattern of antibiotic use flattened into a straight line (R² = 0.96; p = 0.022) with a quarterly change of 3.9% (p = 0.007). Total antibiotic use and antibiotics used for treating acute respiratory tract infections showed significant reductions in all quarters compared to the previous year (p < 0.01).

DISCUSSION

The coronavirus disease 2019 pandemic has strongly influenced the seasonality of antibiotic use in primary care. The decline in respiratory viruses, among which the influenza virus is a major player that may act as a proxy for general prevalence, is proposed as a reason for the flattening of the seasonal fluctuations of outpatient antibiotic use in our region.

Factors associated with recruitment success in the phase 2a study of aztreonam-avibactam development programme: a descriptive qualitative analysis among sites in Spain

OBJECTIVE

Successful clinical trials are subject to recruitment. Recently, the REJUVENATE trial, a prospective phase 2a open-label, single-arm interventional clinical trial conducted within the Innovative Medicines Initiative-supported Combatting Bacterial Resistance in Europe-Carbapenem Resistance project, was published, with 85% of the recruitment performed in Spain. We analysed the recruitment success in this trial by establishing a model of recruitment practice.

METHODS

A descriptive qualitative study was performed from May 2016 to October 2017 at 10 participating Spanish centres. Data were extracted from: (1) feasibility questionnaires to assess the centre's potential for patient enrolment; (2) delegation of responsibility records; (3) pre-screening records including an anonymised list of potentially eligible and (4) screening and enrolment records. A descriptive analysis of the features was performed by the participating centre. Pearson's and Spearman's correlation coefficients were calculated to determine factors of recruitment success.

RESULTS

The highest recruitment rate was observed in Hospitals 3 and 6 (58.8 and 47.0 patients per month, respectively). All the study teams were multidisciplinary with a median of 15 members (range: 7-22). Only Hospitals 3, 5 and 6 had dedicated nursing staff appointed exclusively to this study. Moreover, in those three hospitals and in Hospital 9, the study coordinator performed exclusive functions as a research planner, and did not assume these functions for the other hospitals. The univariate analysis showed a significant association between recruitment success and months of recruitment (p=0.024), number of staff (p<0.001), higher number of pharmacists (p=0.005), infectious disease specialists (p<0.001), the presence of microbiologist in the research team (p=0.018) and specifically dedicated nursing staff (p=0.036).

CONCLUSIONS

The existence of broad multidisciplinary teams with staff dedicated exclusively to the study as well as the implementation of a well-designed local patient assessment strategy were the essential optimisation factors for recruitment success in Spain.

TRIAL REGISTRATION NUMBER

NCT02655419; EudraCT 2015-002726-39; analysis of pre-screened patients.

Seven-versus 14-day course of antibiotics for the treatment of bloodstream infections by Enterobacterales: a randomized, controlled trial

OBJECTIVE

To prove that 7-day courses of antibiotics for bloodstream infections caused by members of the Enterobacterales (eBSIs) allow a reduction in patients' exposure to antibiotics while achieving clinical outcomes similar to those of 14-day schemes.

METHODS

A randomized trial was performed. Adult patients developing eBSI with appropriate source control were assigned to 7 or 14 days of treatment, and followed 28 days after treatment cessation; treatments could be resumed whenever necessary. The primary endpoint was days of treatment at the end of follow-up. Clinical outcomes included clinical cure, relapse of eBSI and relapse of fever. A superiority margin of 3 days was set for the primary endpoint, and a non-inferiority margin of 10% was set for clinical outcomes. Efficacy and safety were assessed together with a DOOR/RADAR (desirability of outcome ranking and response adjusted for duration of antibiotic risk) analysis.

RESULTS

248 patients were assigned to 7 (n = 119) or 14 (n = 129) days of treatment. In the intention-to-treat analysis, median days of treatment at the end of follow-up were 7 and 14 days (difference 7, 95%CI 7-7). The non-inferiority margin was also met for clinical outcomes, except for relapse of fever (-0.2%, 95%CI -10.4 to 10.1). The DOOR/RADAR showed that 7-day schemes had a 77.7% probability of achieving better results than 14-day treatments.

CONCLUSIONS

7-day schemes allowed a reduction in antibiotic exposure of patients with eBSI while achieving outcomes similar to those of 14-day schemes. The possibility of relapsing fever in a limited number of patients, without relevance to final outcomes, may not be excluded, but was overcome by the benefits of shortening treatments.

Do specific antimicrobial stewardship interventions have an impact on carbapenem resistance in Gram-negative bacilli? A multicentre quasi-experimental ecological study: time-trend analysis and characterization of carbapenemases

BACKGROUND

Carbapenem-resistant Gram-negative bacilli (CR-GNB) are among the most threatening microorganisms worldwide and carbapenem use facilitates their spread. Antimicrobial stewardship programmes (ASPs) can help to optimize the use of antibiotics. This study evaluates the impact of a multifaceted educational ASP on carbapenem use and on the epidemiology of CR-GNB.

METHODS

We conducted a quasi-experimental, time-series study in seven hospitals, from January 2014 to September 2018. The key intervention was composed of educational interviews promoting the appropriate use of carbapenems. The primary endpoints were carbapenem consumption and incidence density (ID) of CR-GNB. All non-duplicated CR-GNB clinical isolates were tested using phenotypic assays and PCR for the presence of carbapenemases. Joinpoint regression and interrupted time-series analyses were used to determine trends.

RESULTS

A decrease in carbapenem consumption throughout the study period [average quarterly percentage change (AQPC) -1.5%, P < 0.001] and a -8.170 (-16.064 to -0.277) level change following the intervention were observed. The ID of CR-Acinetobacter baumannii decreased (AQPC -3.5%, P = 0.02) and the overall ID of CR-GNB remained stable (AQPC -0.4%, P = 0.52). CR-GNB, CR-Pseudomonas aeruginosa and CR-A. baumannii IDs per hospital correlated with the local consumption of carbapenems. The most prevalent carbapenem resistance mechanisms were OXA-23 for CR-A. baumannii (76.1%), OXA-48 for CR-Klebsiella pneumoniae (66%) and no carbapenemases for CR-P. aeruginosa (91.7%). The epidemiology of carbapenemases was heterogeneous throughout the study, especially for carbapenemase-producing Enterobacteriaceae.

CONCLUSIONS

In conclusion, a multifaceted, educational interview-based ASP targeting carbapenem prescribing reduced carbapenem use and the ID of CR-A. baumannii.

SARS-CoV-2 viral load in nasopharyngeal swabs is not an independent predictor of unfavorable outcome

The aim was to assess the ability of nasopharyngeal SARS-CoV-2 viral load at first patient's hospital evaluation to predict unfavorable outcomes. We conducted a prospective cohort study including 321 adult patients with confirmed COVID-19 through RT-PCR in nasopharyngeal swabs. Quantitative Synthetic SARS-CoV-2 RNA cycle threshold values were used to calculate the viral load in log₁₀ copies/mL. Disease severity at the end of follow up was categorized into mild, moderate, and severe. Primary endpoint was a composite of intensive care unit (ICU) admission and/or death (n = 85, 26.4%). Univariable and multivariable logistic regression analyses were performed. Nasopharyngeal SARS-CoV-2 viral load over the second quartile (≥ 7.35 log₁₀ copies/mL, p = 0.003) and second tertile (≥ 8.27 log₁₀ copies/mL, p = 0.01) were associated to unfavorable outcome in the unadjusted logistic regression analysis. However, in the final multivariable analysis, viral load was not independently associated with an unfavorable outcome. Five predictors were independently associated with increased odds of ICU admission and/or death: age ≥ 70 years, SpO₂, neutrophils > 7.5 × 10³/µL, lactate dehydrogenase ≥ 300 U/L, and C-reactive protein ≥ 100 mg/L. In summary, nasopharyngeal SARS-CoV-2 viral load on admission is generally high in patients with COVID-19, regardless of illness severity, but it cannot be used as an independent predictor of unfavorable clinical outcome.

Prevalence and Risk Factors for Multidrug-Resistant Organisms Colonization in Long-Term Care Facilities Around the World: A Review

Elderly people confined to chronic care facilities face an increased risk of acquiring infections by multidrug-resistant organisms (MDROs). This review presents the current knowledge of the prevalence and risk factors for colonization by MDROs in long-term care facilities (LTCF), thereby providing a useful reference to establish objectives for implementing successful antimicrobial stewardship programs (ASPs). We searched in PubMed and Scopus for studies examining the prevalence of MDROs and/or risk factors for the acquisition of MDROs in LTCF. One hundred and thirty-four studies published from 1987 to 2020 were included. The prevalence of MDROs in LTCF varies between the different continents, where Asia reported the highest prevalence of extended-spectrum ß-lactamase (ESBL) Enterobacterales (71.6%), carbapenem resistant (CR) Enterobacterales (6.9%) and methicillin-resistant Staphylococcus aureus (MRSA) (25.6%) and North America the highest prevalence to MDR Pseudomonas aeruginosa (5.4%), MDR Acinetobacter baumannii (15.0%), vancomycin-resistant Enterococcus spp. (VRE) (4.0%), and Clostridioides difficile (26.1%). Furthermore, MDRO prevalence has experienced changes over time, with increases in MDR P. aeruginosa and extended spectrum ß-lactamase producing Enterobacterales observed starting in 2015 and decreases of CR Enterobacterales, MDR A. baumannii, VRE, MRSA and C. difficile. Several risk factors have been found, such as male sex, chronic wounds, the use of medical devices, and previous antibiotic use. The last of these aspects represents one of the most important modifiable factors for reducing colonization with MDROs through implementing ASPs in LTCF.

Impact of an Antimicrobial Stewardship Program on the Incidence of Carbapenem Resistant Gram-Negative Bacilli: An Interrupted Time-Series Analysis

Carbapenem-resistant Gram-negative bacilli (CR-GNB) are a critical public health threat, and carbapenem use contributes to their spread. Antimicrobial stewardship programs (ASPs) have proven successful in reducing antimicrobial use. However, evidence on the impact of carbapenem resistance remains unclear. We evaluated the impact of a multifaceted ASP on carbapenem use and incidence of CR-GNB in a high-endemic hospital. An interrupted time-series analysis was conducted one year before and two years after starting the ASP to assess carbapenem consumption, CR-GNB incidence, death rates of sentinel events, and other variables potentially related to CR-GNB incidence. An intense reduction in carbapenem consumption occurred after starting the intervention and was sustained two years later (relative effect -83.51%; 95% CI -87.23 to -79.79). The incidence density of CR-GNB decreased by -0.915 cases per 1000 occupied bed days (95% CI -1.743 to -0.087). This effect was especially marked in CR-Klebsiella pneumoniae and CR-Escherichia coli, reversing the pre-intervention upward trend and leading to a relative reduction of -91.15% (95% CI -105.53 to -76.76) and -89.93% (95% CI -107.03 to -72.83), respectively, two years after starting the program. Death rates did not change. This ASP contributed to decreasing CR-GNB incidence through a sustained reduction in antibiotic use without increasing mortality rates.

High incidence of MDR and XDR Pseudomonas aeruginosa isolates obtained from patients with ventilator-associated pneumonia in Greece, Italy and Spain as part of the MagicBullet clinical trial

OBJECTIVES

To characterize the antimicrobial susceptibility, molecular epidemiology and carbapenem resistance mechanisms in Pseudomonas aeruginosa isolates recovered from respiratory tract samples from patients with ventilator-associated pneumonia enrolled in the MagicBullet clinical trial.

METHODS

Isolates were collected from 53 patients from 12 hospitals in Spain, Italy and Greece. Susceptibility was determined using broth microdilution and Etest. MALDI-TOF MS was used to detect carbapenemase activity and carbapenemases were identified by PCR and sequencing. Molecular epidemiology was investigated using PFGE and MLST.

RESULTS

Of the 53 isolates, 2 (3.8%) were considered pandrug resistant (PDR), 19 (35.8%) were XDR and 16 (30.2%) were MDR. Most (88.9%) of the isolates from Greece were MDR, XDR or PDR, whereas fewer of the isolates from Spain (33.3%) and Italy (43.5%) showed antibiotic resistance. Three Greek isolates were resistant to colistin. Overall, the rates of resistance of P. aeruginosa isolates to imipenem, ciprofloxacin, ceftolozane/tazobactam and ceftazidime/avibactam were 64.1%, 54.7%, 22.6% and 24.5%, respectively. All isolates resistant to ceftolozane/tazobactam and ceftazidime/avibactam (Greece, n = 10; and Italy, n = 2) carried blaVIM-2. Spanish isolates were susceptible to the new drug combinations. Forty-eight restriction patterns and 27 STs were documented. Sixty percent of isolates belonged to six STs, including the high-risk clones ST-111, ST-175 and ST-235.

CONCLUSIONS

MDR/XDR isolates were highly prevalent, particularly in Greece. The most effective antibiotic against P. aeruginosa was colistin, followed by ceftolozane/tazobactam and ceftazidime/avibactam. blaVIM-2 is associated with resistance to ceftolozane/tazobactam and ceftazidime/avibactam, and related to highly resistant phenotypes. ST-111 was the most frequent and disseminated clone and the clonal diversity was lower in XDR and PDR strains.

Long-Term Impact of an Educational Antimicrobial Stewardship Program on Management of Patients with Hematological Diseases

Antimicrobial stewardship programs (ASPs) in hematological patients are especially relevant. However, information about ASPs in this population is scarce. For 11 years, we quarterly assessed antimicrobial consumption and incidence and death rates of multidrug-resistant (MDR) bloodstream infections (BSI) in the hematology Department. Healthcare activity indicators were also monitored yearly. We performed an interrupted time-series analysis. Antimicrobials showed a sustained reduction with a relative effect of −62.3% (95% CI −84.5 to −40.1) nine years after the inception of the ASP, being especially relevant for antifungals (relative effect −80.4%, −90.9 to −69.9), quinolones (relative effect −85.0%, −102.0 to −68.1), and carbapenems (relative effect −68.8%, −126.0 to −10.6). Incidence density of MDR BSI remained low and stable (mean 1.10 vs. 0.82 episodes per 1000 occupied bed days for the pre-intervention and the ASP period, respectively) with a quarterly percentage of change of −0.3% (95% CI −2.0 to 1.4). Early and late mortality of MDR BSI presented a steady trend (quarterly percentage of change −0.7%, 95% CI −1.7 to 0.3 and −0.6%, 95% CI −1.5 to 0.3, respectively). Volume and complexity of healthcare activity increased over the years. The ASP effectively achieved long-term reductions in antimicrobial consumption and improvements in the prescription profile, without increasing the mortality of MDR BSI.

Impact of the COVID-19 Pandemic on Antimicrobial Consumption and Hospital-Acquired Candidemia and Multidrug-Resistant Bloodstream Infections

During the COVID-19 pandemic, the implementation of antimicrobial stewardship strategies has been recommended. This study aimed to assess the impact of the COVID-19 pandemic in a tertiary care Spanish hospital with an active ongoing antimicrobial stewardship programme (ASP). For a 20-week period, we weekly assessed antimicrobial consumption, incidence density, and crude death rate per 1000 occupied bed days of candidemia and multidrug-resistant (MDR) bacterial bloodstream infections (BSI). We conducted a segmented regression analysis of time series. Antimicrobial consumption increased +3.5% per week (p = 0.016) for six weeks after the national lockdown, followed by a sustained weekly reduction of −6.4% (p = 0.001). The global trend for the whole period was stable. The frequency of empirical treatment of patients with COVID-19 was 33.7%. No change in the global trend of incidence of hospital-acquired candidemia and MDR bacterial BSI was observed (+0.5% weekly; p = 0.816), nor differences in 14 and 30-day crude death rates (p = 0.653 and p = 0.732, respectively). Our work provides quantitative data about the pandemic effect on antimicrobial consumption and clinical outcomes in a centre with an active ongoing institutional and education-based ASP. However, assessing the long-term impact of the COVID-19 pandemic on antimicrobial resistance is required.

Defining persistent Staphylococcus aureus bacteraemia: secondary analysis of a prospective cohort study

BACKGROUND

Staphylococcus aureus persistent bacteraemia is only vaguely defined and the effect of different durations of bacteraemia on mortality is not well established. Our primary aim was to analyse mortality according to duration of bacteraemia and to derive a clinically relevant definition for persistent bacteraemia.

METHODS

We did a secondary analysis of a prospective observational cohort study at 17 European centres (nine in the UK, six in Spain, and two in Germany), with recruitment between Jan 1, 2013, and April 30, 2015. Adult patients who were consecutively hospitalised with monomicrobial S aureus bacteraemia were included. Patients were excluded if no follow-up blood culture was taken, if the first follow-up blood-culture was after 7 days, or if active antibiotic therapy was started more than 3 days after first blood culture. The primary outcome was 90-day mortality. Univariable and time-dependent multivariable Cox regression analysis were used to assess predictors of mortality. Duration of bacteraemia was defined as bacteraemic days under active antibiotic therapy counting the first day as day 1.

FINDINGS

Of 1588 individuals assessed for eligibility, 987 were included (median age 65 years [IQR 51-75]; 625 [63%] male). Death within 90 days occurred in 273 (28%) patients. Patients with more than 1 day of bacteraemia (315 [32%]) had higher Charlson comorbidity index and sequential organ failure assessment scores and a longer interval from first symptom to first blood culture. Crude 90-day mortality increased from 22% (148 of 672) with 1 day of bacteraemia, to 39% (85 of 218) with 2-4 days, 43% (30 of 69) with 5-7 days, and 36% (10 of 28) with more than 7 days of bacteraemia. Metastatic infections developed in 39 (6%) of 672 patients with 1 day of bacteraemia versus 40 (13%) of 315 patients if bacteraemia lasted for at least 2 days. The second day of bacteraemia had the highest HR and earliest cutoff significantly associated with mortality (adjusted hazard ratio 1·93, 95% CI 1·51-2·46; p<0·0001).

INTERPRETATION

We suggest redefining the cutoff duration for persistent bacteraemia as 2 days or more despite active antibiotic therapy. Our results favour follow-up blood cultures after 24 h for early identification of all patients with increased risk of death and metastatic infection.

FUNDING

None.

Usefulness of guideline recommendations for prognosis in patients with candidemia

We aimed to analyze whether the lack of inclusion of specific recommendations for the management of candidemia is an independent risk factor for early and overall mortality. Multicenter study of adult patients with candidemia in 13 hospitals. We assessed the proportion of patients on whom nine specific ESCMID and IDSA guidelines recommendations had been applied, and analyzed its impact on mortality. 455 episodes of candidemia were documented. Patients who died within the first 48 hours were excluded. Sixty-two percent of patients received an appropriate antifungal treatment. Either echinocandin or amphotericin B therapy were administered in 43% of patients presenting septic shock and in 71% of those with neutropenia. Sixty-one percent of patients with breakthrough candidemia underwent a change in antifungal drug class. Venous catheters were removed in 79% of cases. Follow-up blood cultures were performed in 72% of cases. Ophthalmoscopy and echocardiogram were performed in 48% and 50% of patients, respectively. Length of treatment was appropriate in 78% of cases. Early (2-7 days) and overall (2-30 days) mortality were 8% and 27.7%, respectively. Inclusion of less than 50% of the specific recommendations was independently associated with a higher early (HR = 7.02, 95% CI: 2.97-16.57; P < .001) and overall mortality (HR = 3.55, 95% CI: 2.24-5.64; P < .001). In conclusion, ESCMID and IDSA guideline recommendations were not performed on a significant number of patients. Lack of inclusion of these recommendations proved to be an independent risk factor for early and overall mortality.

A multimodal intervention program to control a long-term Acinetobacter baumannii endemic in a tertiary care hospital

Background

Acinetobacter baumannii causes frequently nosocomial infections worldwide. Its ability to survive on dry surfaces facilitates its spread and the persistence of endemic situations, especially in the intensive care units (ICUs).

The objective of this paper is to describe a multicomponent intervention program designed to control a hyperendemic persistence of multidrug-resistant A. baumannii (MDR-Ab) and to characterize its impact.

Methods

Design: Quasi-experimental intervention study based on open cohorts.

Setting: Public tertiary referral centre. Period: January 2009–August 2017.

Intervention: multifaceted program based on environmental decontamination, hand hygiene, antimicrobial stewardship, contact precautions, active surveillance, weekly reports and regular meetings.

Analysis: joinpoint regression and interrupted time-series analysis.

Results

The intervention was successfully implemented. Through the study period, the compliance with contact precautions changed from 0 to 100% and with hand hygiene, from 41.8 to 82.3%. Between 2012 and 2016, the antibiotic consumption decreased from 165.35 in to 150.44 daily-defined doses/1000 patients-days in the ICU. The incidence density of MDR-Ab in the ICU was 10.9 cases/1000 patients-days at the beginning of the intervention. After this moment, the evolution of the incidence density of MDR-Ab was: between months 0 and 6°, it remained stable; between months 7° and 10°: there was an intense decrease, with an average monthly percentage change (AMPC) = − 30.05%; from 11° month until the end, the decrease was lighter but continuous (AMPC:-2.77%), achieving an incidence density of 0 cases/1000 patients-days on the 18° month, without any new case for 12 months. From the 30° month until the end of the study period, several little outbreaks of MDR-Ab were detected, all of them rapidly controlled. The strains of MDR-Ab isolated during these outbreaks were not clonally related with the previously endemic one, which supports its eradication from the environmental reservoirs.

Conclusion

The multicomponent intervention performed by a multidisciplinary team was effective to eradicate the endemic MDR-Ab.

Long-term impact of an educational antimicrobial stewardship programme in primary care on infections caused by extended-spectrum β-lactamase-producing Escherichia coli in the community: an interrupted time-series analysis

BACKGROUND

There is little evidence on the ecological effect and sustainability of antimicrobial stewardship programmes (ASPs) in primary-care settings. We aimed to determine whether a multimodal, educational ASP would be sustainable in the long-term and reduce the incidence of infections caused by extended-spectrum β-lactamase-producing Escherichia coli in the community by optimising antibiotic use.

METHODS

We did this quasi-experimental intervention study in 214 primary health centres of four primary health-care districts in Andalusia, Spain. Local multidisciplinary teams, comprised of general practitioners, paediatricians, primary-care pharmacists, and epidemiologists, were created in each district and implemented a multimodal, education-based ASP. The core activity of the programme consisted of regular one-to-one educational interviews between a reference interviewing physician and prescribing physicians from each centre on the appropriateness of their most recent (same or preceding day) antibiotic prescriptions based on a structured questionnaire. Appropriate prescribing was defined as compliance of all checklist items with the reference guidelines. An average of five educational interviews were scheduled per prescriber per study year. We did an interrupted time-series analysis to assess the effect of the intervention on quarterly antibiotic use (prescription and collection by the patient) and quality of prescriptions (as defined daily doses per 1000 inhabitants per day) and incidence per 1000 inhabitants of E coli producing extended-spectrum β-lactamase (ESBL) isolated from urine samples.

FINDINGS

The study was done between January, 2012, and December, 2017, in a pre-intervention period of 2012-13 and an intervention period of 2014-17. Throughout the study period, there were 1387 physicians (1116 general practicioners and 271 paediatricians) in the included health centres serving a mean population of 1 937 512 people (299 331 children and 1 638 181 adults). 24 150 educational interviews were done over the 4 years. Inappropriate antibiotic prescribing was identified in 1794 (36·5%) of 4917 educational interviews in 2014 compared with 1793 (26·9%) of 6665 in 2017 (p<0·0001). The intervention was associated with a sustained reduction in the use of ciprofloxacin (relative effect -15·9%, 95% CI -23·9 to -8·0) and cephalosporins (-22·6%, -35·9 to -9·2), and a sustained increase in the use of amoxicillin (22·2%, 6·4 to 38·0) and fosfomycin trometamol (6·1%, 2·6 to 9·6). The incidence density of ESBL-producing E coli decreased by -0·028 cases per 1000 inhabitants (95% CI -0·034 to -0·021) after the start of the programme, reversing the pre-intervention increase and leading to a relative reduction of -65·6% (-68·2 to -63·0) 4 years later.

INTERPRETATION

Our data suggest that implementation of a multimodal ASP in primary care that is based on individual educational interviews improves the use of antibiotics and results in a sustained significant reduction of infections by ESBL-producing E coli in the community. This information should encourage the implementation of ASPs in primary care.

FUNDING

Instituto de Salud Carlos III, Spanish Government (PI14/01523).

Evaluation of the impact of a nationwide massive online open course on the appropriate use of antimicrobials

Objectives

To evaluate the impact of a massive online open course (MOOC) design on the appropriate use of antimicrobial agents, to determine specific study areas with better learning outcomes and to identify weak points.

Methods

A pre- and post-intervention study in the context of a training course on infectious diseases aimed at health professionals. We designed a questionnaire with 30 questions related to the management of infectious diseases in different clinical situations. Participants had to answer the questions based on their competencies and training for these situations. We analysed the scores obtained before and after the course and the resulting progress. In addition, an open response section was provided to enable a qualitative evaluation.

Results

Two thousand one hundred and forty-eight health professionals were enrolled in the course. The questionnaire was completed before and after the course by 606 participants, mainly physicians (81.2%) and pharmacists (15.4%). The mean overall scores for the pre- and post-course questionnaires were 6.2 (SD 1.38) and 7.9 (SD 0.88), respectively (overall score increase = 1.8, SD 1.21, P < 0.001). A significant increase in self-assessment was detected (P < 0.001) for all the questions. Qualitative assessments were provided by 218 participants with 225 comments, most of which were very positive.

Conclusions

The course with a MOOC design showed a great teaching capacity in the infectious diseases area for all the clinical situations analysed, notably in the management of severe infections with higher mortality. For future editions of this training activity, the need to include other infectious diseases, especially infections in primary care, was highlighted.

Outcomes of the PIRASOA programme, an antimicrobial stewardship programme implemented in hospitals of the Public Health System of Andalusia, Spain: an ecologic study of time-trend analysis

OBJECTIVES

Inappropriate antimicrobial use favours the spread of resistance, and multidrug-resistant microorganisms (MDR) are currently of major concern. Antimicrobial stewardship programmes (ASPs) are essential for improving antibiotic use in hospitals. However, their impact on entire healthcare systems has not been thoroughly assessed. Our objective was to provide the results of an institutionally supported ASP involving 31 public hospitals in Andalusia, Spain.

METHODS

We designed an ecologic time-series study from 1 January 2014 to 31 December 2017. Quarterly, data on indicators were collected prospectively, and feedback reports were provided. PIRASOA is an ongoing clinically based quality-improvement programme whose key intervention is the educational interview, regular peer-to-peer interventions between advisors and prescribers to reinforce the appropriate use of antibiotics. Seventy-two indicators were monitored to measure prescribing quality (inappropriate treatments), antimicrobial consumption (defined daily doses per 1000 occupied bed-days), incidence density of MDR per 1000 occupied bed-days and crude mortality rate associated with bloodstream infections. We used Joinpoint regression software to analyse the trends.

RESULTS

The quality of antimicrobial prescribing improved markedly, and the inappropriate treatment rate was significantly lower, with quarterly percentage change (QPC) = -3.0%, p < 0.001. Total antimicrobial consumption decreased (QPC = -0.9%, p < 0.001), specifically carbapenems, amoxicillin/clavulanic acid, quinolones and antifungal agents, whereas antipseudomonal cephalosporin use increased. While the incidence of MDR showed a sustained decreasing trend (QPC = -1.8%; p 0.002), the mortality of patients with bloodstream infections remained stable (QPC = -0.2%, p 0.605).

CONCLUSIONS

To date, the PIRASOA programme has succeeded in optimizing the use of antimicrobial agents and has had a positive ecologic result on bacterial resistance at level of an entire healthcare system.

Clinical impact of an educational antimicrobial stewardship program associated with infectious diseases consultation targeting patients with cancer: Results of a 9-year quasi-experimental study with an interrupted time-series analysis

OBJECTIVES

Antibiotic stewardship programs (ASP) have already demonstrated clinical benefits. However, their effectiveness or safety in immunocompromised hosts needs to be proved.

METHODS

An ecologic quasi-experimental study was performed from January 2009 to June 2017 in the Oncology department of a tertiary-care hospital. A stable program of Infectious Diseases consultation (IDC) already existed at this unit, and an educational ASP was added in 2011. Its main intervention consisted of face-to-face educational interviews. Antibiotic consumption was assessed through quarterly Defined Daily Doses (DDD) per 100 occupied bed-days. Mortality was evaluated in patients with bloodstream infections through the quarterly incidence density per 1000 admissions, and the annual mortality rates at 7 and 30-days. Time-trends were analysed through segmented-regression analysis, and the impact of the ASP was assessed through before-after interrupted time-series analysis.

RESULTS

Mortality significantly decreased throughout the study period (-13.3% annual reduction for 7-day mortality rate, p < 0.01; -8.1% annual reduction for 30-day mortality, p = 0.03), parallel to a reduction in antibiotic consumption (quarterly reduction -0.4%, p = 0.01), especially for broader-spectrum antibiotics. The before-after study settled a significant inflexion point on the ASP implementation for the reduction of antibiotic consumption (change in level 0.95 DDD, p = 0.71; change in slope -1.98 DDD per quarter, p < 0.01). The decreasing trend for mortality before the ASP also continued after its implementation.

CONCLUSIONS

The combination of an ASP with IDC improved antibiotic use among patients with cancer, and was accompanied by a reduction of mortality of bacteraemic infections. Implementation of the ASP was necessary to effectively change antibiotic use.

Impact of De-escalation on Prognosis of Patients With Bacteremia due to Enterobacteriaceae: A Post Hoc Analysis From a Multicenter Prospective Cohort

Background

More data are needed about the safety of antibiotic de-escalation in specific clinical situations as a strategy to reduce exposure to broad-spectrum antibiotics. The aims of this study were to investigate predictors of de-escalation and its impact on the outcome of patients with bloodstream infection due to Enterobacteriaceae (BSI-E).

Methods

A post hoc analysis was performed on a prospective, multicenter cohort of patients with BSI-E initially treated with ertapenem or antipseudomonal β-lactams. Logistic regression was used to analyze factors associated with early de-escalation (EDE) and Cox regression for the impact of EDE and late de-escalation (LDE) on 30-day all-cause mortality. A propensity score (PS) for EDE vs no de-escalation (NDE) was calculated. Failure at end of treatment and length of hospital stay were also analyzed.

Results

Overall, 516 patients were included. EDE was performed in 241 patients (46%), LDE in 95 (18%), and NDE in 180 (35%). Variables independently associated with a lower probability of EDE were multidrug-resistant isolates (odds ratio [OR], 0.50 [95% confidence interval {CI}, .30–.83]) and nosocomial infection empirically treated with imipenem or meropenem (OR, 0.35 [95% CI, .14–.87]). After controlling for confounders, EDE was not associated with increased risk of mortality; hazard ratios (HR) (95% CIs) were as follows: general model, 0.58 (.25–1.31); model with PS, 0.69 (.29–1.65); and PS-based matched pairs, 0.98 (.76–1.26). LDE was not associated with mortality. De-escalation was not associated with clinical failure or length of hospital stay.

Conclusions

De-escalation in patients with monomicrobial bacteremia due to Enterobacteriaceae was not associated with a detrimental impact on clinical outcome.

Predictors of outcome in patients with severe sepsis or septic shock due to extended-spectrum β-lactamase-producing Enterobacteriaceae

PURPOSE

There are few data in the literature regarding sepsis or septic shock due to extended-spectrum β-lactamases (ESBL)-producing Enterobacteriaceae (E). The aim of this study was to assess predictors of outcome in septic patients with bloodstream infection (BSI) caused by ESBL-E.

METHODS

Patients with severe sepsis or septic shock and BSI due to ESBL-E were selected from the INCREMENT database. The primary endpoint of the study was the evaluation of predictors of outcome after 30 days from development of severe sepsis or septic shock due to ESBL-E infection. Three cohorts were created for analysis: global, empirical-therapy and targeted-therapy cohorts.

RESULTS

367 septic patients were analysed. Overall mortality was 43.9% at 30 days. Escherichia coli (62.4%) and Klebsiella pneumoniae (27.2%) were the most frequent isolates. β-lactam/β-lactamase inhibitor (BLBLI) combinations were the most empirically used drug (43.6%), followed by carbapenems (29.4%). Empirical therapy was active in vitro in 249 (67.8%) patients, and escalation of antibiotic therapy was reported in 287 (78.2%) patients. Cox regression analysis showed that age, Charlson Comorbidity Index, McCabe classification, Pitt bacteremia score, abdominal source of infection and escalation of antibiotic therapy were independently associated with 30-day mortality. No differences in survival were reported in patients treated with BLBLI combinations or carbapenems in empirical or definitive therapy.

CONCLUSIONS

BSI due to ESBL-E in patients who developed severe sepsis or septic shock was associated with high 30-day mortality. Comorbidities, severity scores, source of infection and antibiotic therapy escalation were important determinants of unfavorable outcome.