Patient Antimicrobial Stewardship Research Articles

The impact of immunosuppressive therapy on secondary infections and antimicrobial use in COVID-19 inpatients: a retrospective cohort study

BackgroundImmunosuppressive therapies have become a cornerstone of the management of severe COVID-19. The impact of these therapies on secondary infections and antimicrobial prescribing remains unclear. We sought to assess antimicrobial use and the incidence of bacterial and fungal infections in patients with severe COVID-19, and to explore their associations with receipt of immunosuppressive therapies.MethodsOur retrospective cohort study included 715 hospitalised, adult patients with severe COVID-19 admitted to St George’s Hospital, London, UK, during the first UK pandemic wave (1st March–10th June 2020). Co-infections (occurring within 48 h of admission) and secondary infections (≥ 48 h) were defined as a positive microbiological culture with supporting clinical, radiological or laboratory data to suggest true infection. Cox regression models with time-dependent covariates were used to explore the association between immunosuppressant use and secondary infection.ResultsMicrobiologically confirmed co-infection occurred in 4.2% (n = 30) and secondary infection in 9.3% (n = 66) of the cohort (n = 715) and were associated with in-hospital mortality (48% vs 35%, OR 1.8, 95%CI 1.1–2.7, p = 0.01). Respiratory (n = 41, 39%) and bloodstream infections (n = 38, 36%) predominated, with primarily Gram-negative pathogens. 606 (84.7%) patients received an antimicrobial, amounting to 742 days of therapy per 1000 patient-days (DOTs). In multivariable models, receipt of high-dose steroids (≥ 30 mg prednisolone or equivalent) or tocilizumab was significantly associated with increased antimicrobial consumption (+ 5.5 DOTs, 95%CI 3.4–7.7 days) but not secondary infection (HR 0.56, 95%CI 0.26–1.18).ConclusionsBacterial and fungal infections in severe COVID-19 were uncommon. Receipt of steroids or tocilizumab was independently associated with antimicrobial consumption despite its lack of association with secondary infection. These findings should galvanise efforts to promote antimicrobial stewardship in patients with COVID-19.

Rapid Point-of-Care PCR Testing of Drug-Resistant Strains on Endotracheal Aspirate Samples: A Repurposed Effective Tool in the Stepwise Approach of Healthcare-Acquired Pneumonia-A Pilot Study.

Healthcare-associated pneumonia (HCAP) is a common nosocomial infection with high morbidity and mortality. Culture-based detection of the etiologic agent and drug susceptibility is time-consuming, potentially leading to the inadequate use of broad-spectrum empirical antibiotic regimens. The aim was to evaluate the diagnostic capabilities of rapid point-of-care multiplex polymerase chain reaction (PCR) assays from the endotracheal aspirate of critically ill patients with HCAP. A consecutive series of 29 intensive care unit (ICU) patients with HCAP and a control group of 28 patients undergoing elective surgical procedures were enrolled in the study. The results of the PCR assays were compared to the culture-based gold standard. The overall accuracy of the PCR assays was 95.12%, with a sensitivity of 92.31% and a specificity of 97.67%. The median time was 90 min for the rapid PCR tests (p < 0.001), while for the first preliminary results of the cultures, it was 48 h (46-72). The overall accuracy for rapid PCR testing in suggesting an adequate antibiotic adjustment was 82.98% (95% CI 69.19-92.35%), with a specificity of 90% (95% CI 55.50-99.75%), a positive predictive value of 96.77% (95% CI 83.30-99.92%), and a negative predictive value of 56.25 (95% CII 29.88-80.25%). This method of rapid point-of-care PCR could effectively guide antimicrobial stewardship in patients with healthcare-acquired pneumonia.

Impact of Metagenomic Next-Generation Sequencing of Bronchoalveolar Lavage Fluid on Antimicrobial Stewardship in Patients With Lower Respiratory Tract Infections: A Retrospective Cohort Study.

The impact of metagenomic next-generation sequencing (mNGS) on antimicrobial stewardship in patients with lower respiratory tract infections (LRTIs) is still unknown. This retrospective cohort study included patients who had LRTIs diagnosed and underwent bronchoalveolar lavage between September 2019 and December 2020. Patients who underwent both mNGS and conventional microbiologic tests were classified as the mNGS group, while those with conventional tests only were included as a control group. A 1:1 propensity score match for baseline variables was conducted, after which changes in antimicrobial stewardship between the 2 groups were assessed. A total of 681 patients who had an initial diagnosis of LRTIs and underwent bronchoalveolar lavage were evaluated; 306 patients were finally included, with 153 in each group. mNGS was associated with lower rates of antibiotic escalation than in the control group (adjusted odds ratio, 0.466 [95% confidence interval, .237-.919]; P = .02), but there was no association with antibiotic de-escalation. Compared with the control group, more patients discontinued the use of antivirals in the mNGS group. The use of mNGS was associated with lower rates of antibiotic escalation and may facilitate the cessation of antivirals, but not contribute to antibiotic de-escalation in patients with LRTIs.

Importance of antimicrobial stewardship in solid organ transplant recipients: An ESCMID perspective.

In the last decades, solid organ transplantation (SOT) has emerged as an important method in the management of chronic kidney, liver, heart, and lung failure. Antimicrobial use has led to a significant reduction of morbidity and mortality due to infectious complications among patients with SOT; however, it can lead to adverse events and drive the development of antimicrobial resistance; thus, antimicrobial stewardship is of extreme importance. Even though there are ongoing efforts of transplant societies to implement principles of antimicrobial stewardship in everyday practice in SOT, there is still a lack of guidelines in this patient population. The aim of this study was to review the status of antimicrobial stewardship in patients with SOT, highlight its importance from the perspective of an ongoing vivid dialogue among ESCMID experts in the field of antimicrobial stewardship, and depict opportunities for future study in the field. Antimicrobial stewardship programs are important in order to allow appropriate initiation and termination of antimicrobials in SOT recipients, and also aid in the most appropriate dosing and choosing of the route of administration of antimicrobials. Application of already known antimicrobial stewardship principles and application of currently used biomarkers and newly developed molecular rapid diagnostic testing tools can aid to the rationalization of antimicrobial prescribing and to a more targeted treatment of infections. Finally, physicians caring for SOT recipients should be actively involved in antimicrobial stewardship in order to assure optimization of antimicrobial prescribing and become familiar with the principles of antimicrobial stewardship.

Antimicrobial Stewardship in Patients with Penicillin Allergy Undergoing Hysterectomy for Benign Indications

Antimicrobial Stewardship in Patients with Penicillin Allergy Undergoing Hysterectomy for Benign Indications

Use of a Novel Clinical Decision Support Tool for Pharmacist-Led Antimicrobial Stewardship in Patients with Normal Procalcitonin.

In 2018, a clinical decision support (CDS) tool was implemented as part of a “daily checklist” for frontline pharmacists to review patients on antibiotics with procalcitonin (PCT) <0.25 mcg/L. This study used a retrospective cohort design to assess change in antibiotic use from pharmacist interventions after this PCT alert in patients on antibiotics for lower respiratory tract infections (LRTI). The secondary outcome was antibiotic days of therapy (DOT), with a subgroup analysis examining antibiotic use and the length of stay (LOS) in patients with a pharmacist intervention. From 1/2019 to 11/2019, there were 165 alerts in 116 unique patients on antibiotics for LRTI. Pharmacists attempted interventions after 34 (20.6%) of these alerts, with narrowing spectrum or converting to oral being the most common interventions. Pharmacist interventions prevented 125 DOT in the hospital. Vancomycin was the most commonly discontinued antibiotic with an 85.3% use reduction in patients with interventions compared to a 27.4% discontinuation in patients without documented intervention (p = 0.0156). The LOS was similar in both groups (median 6.4 days vs. 7 days, p = 0.81). In conclusion, interventions driven by a CDS tool for pharmacist-driven antimicrobial stewardship in patients with a normal PCT resulted in fewer DOT and significantly higher rates of vancomycin discontinuation.

Antimicrobial stewardship in patients with confirmed coronavirus disease 2019 (COVID-19).

Hospitalized coronavirus disease 2019 (COVID-19) patients receiving antibiotics (n = 173) were retrospectively assigned to the early or late discontinuation groups. The length of therapy was shorter in the early discontinuation group (3 vs 7 days; P < .0001). Mortality rates (14.3% vs 20.7%; P = .316) and length of stay (7 vs 9 days; P = .063) were similar.

Evaluation of procalcitonin-guided antimicrobial stewardship in patients admitted to hospital with COVID-19 pneumonia.

BackgroundProcalcitonin is a biomarker that may be able to identify patients with COVID-19 pneumonia who do not require antimicrobials for bacterial respiratory tract co-infections.ObjectivesTo evaluate the safety and effectiveness of a procalcitonin-guided algorithm in rationalizing empirical antimicrobial prescriptions in non-critically ill patients with COVID-19 pneumonia.MethodsRetrospective, single-site, cohort study in adults hospitalized with confirmed or suspected COVID-19 pneumonia and receiving empirical antimicrobials for potential bacterial respiratory tract co-infection. Regression models were used to compare the following outcomes in patients with and without procalcitonin testing within 72 h of starting antimicrobials: antimicrobial consumption (DDD); antimicrobial duration; a composite safety outcome of death, admission to HDU/ICU or readmission to hospital within 30 days; and length of admission. Procalcitonin levels of ≤0.25 ng/L were interpreted as negatively predictive of bacterial co-infection. Effects were expressed as ratios of means (ROM) or prevalence ratios (PR) accordingly.Results259 patients were included in the final analysis. Antimicrobial use was lower in patients who had procalcitonin measured within 72 h of starting antimicrobials: mean antimicrobial duration 4.4 versus 5.4 days, adjusted ROM 0.7 (95% CI 0.6–0.9); mean antimicrobial consumption 6.8 versus 8.4 DDD, adjusted ROM 0.7 (95% CI 0.6–0.8). Both groups had similar composite safety outcomes (adjusted PR 0.9; 95% CI 0.6–1.3) and lengths of admission (adjusted ROM 1.3; 95% CI 0.9–1.6).ConclusionsA procalcitonin-guided algorithm may allow for the safe reduction of antimicrobial usage in hospitalized non-critically ill patients with COVID-19 pneumonia.

Systems biology evaluation of refractory Clostridioides difficile infection including multiple failures of fecal microbiota transplantation

BackgroundFecal microbiota transplantation (FMT) aims to cure Clostridioides difficile infection (CDI) through reestablishing a healthy microbiome and restoring colonization resistance. Although often effective after one infusion, patients with continued microbiome disruptions may require multiple FMTs. In this N-of-1 study, we use a systems biology approach to evaluate CDI in a patient receiving chronic suppressive antibiotics with four failed FMTs over two years. MethodsSeven stool samples were obtained between 2016-18 while the patient underwent five FMTs. Stool samples were cultured for C. difficile and underwent microbial characterization and functional gene analysis using shotgun metagenomics. C. difficile isolates were characterized through ribotyping, whole genome sequencing, metabolic pathway analysis, and minimum inhibitory concentration (MIC) determinations. ResultsGrowing ten strains from each sample, the index and first four recurrent cultures were single strain ribotype F078-126, the fifth was a mixed culture of ribotypes F002 and F054, and the final culture was ribotype F002. One single nucleotide polymorphism (SNP) variant was identified in the RNA polymerase (RNAP) β-subunit RpoB in the final isolated F078-126 strain when compared to previous F078-126 isolates. This SNV was associated with metabolic shifts but phenotypic differences in fidaxomicin MIC were not observed. Microbiome differences were observed over time during vancomycin therapy and after failed FMTs. ConclusionThis study highlights the importance of antimicrobial stewardship in patients receiving FMT. Continued antibiotics play a destructive role on a transplanted microbiome and applies selection pressure for resistance to the few antibiotics available to treat CDI.

86. Use of a Novel Clinical Decision Support Tool for Pharmacist-Led Antimicrobial Stewardship in Patients with Normal Procalcitonin

BackgroundOur Antimicrobial Stewardship Program (ASP) instituted review of patients on antibiotics with procalcitonin (PCT) < 0.25 mcg/L in 2012. In 2018, a clinical decision support (CDS) tool was implemented as part of a “daily checklist” for frontline pharmacists to assist in this patient review. We sought to validate the effectiveness of this tool for pharmacist-led PCT-based antibiotic stewardship.MethodsA retrospective cohort design was used to assess antibiotic de-escalation after PCT alert in patients on antibiotics for lower respiratory tract infections (LRTI). Secondary outcomes included antibiotic use and length of stay (LOS) in patients with PCT interventions vs those without.ResultsFrom 1/2019 to 11/2019, 652 of 976 (66.8%) PCT alerts were addressed by pharmacists. Of these, 331 were in patients with a respiratory-related diagnosis at discharge and 165 alerts were in patients on antibiotics specifically for LRTI over 119 encounters. Pharmacists made or attempted interventions after 34 (20.6%) of these alerts, with narrowing spectrum or converting to oral therapy being the most common interventions. Antibiotics were completely stopped in 4 of these interventions (11.8%). Patients with pharmacist intervention had 125 fewer antibiotic days of therapy (DOT) in the hospital, and changes were made to an additional 56 DOT (narrower therapy, IV to PO, dose optimization) following the alert. Two cases (5.9%) subsequently had therapy escalated within 48 hours. Vancomycin was the most commonly discontinued antibiotic with an 85.3% use reduction in patients with interventions compared to 27.4% discontinuation in patients with no documented intervention (p=0.0156). Alerts eligible for de-escalation but with no pharmacist intervention represented 140 DOT. LOS was similar in patients from both groups (median 6.4 days vs. 7 days, p=0.81).ConclusionInterventions driven by a CDS tool for pharmacist-driven antimicrobial stewardship in patients with normal PCT resulted in fewer DOT and significantly higher rates of vancomycin discontinuation. Additional interventions could have potentially prevented 140 DOT. We feel refinement of this tool can lead to more meaningful CDS, reduce alert fatigue, and likely increase intervention rates.Disclosures All Authors: No reported disclosures

Improving Antimicrobial Stewardship in Patients With Cancer With the Use of Molecular Diagnostic Tests

Improving Antimicrobial Stewardship in Patients With Cancer With the Use of Molecular Diagnostic Tests

Prescriber Commitment Posters to Increase Prudent Antibiotic Prescribing in English General Practice: A Cluster Randomized Controlled Trial.

Unnecessary antibiotic prescribing contributes to Antimicrobial Resistance posing a major public health risk. Estimates suggest as many as half of antibiotics prescribed for respiratory infections may be unnecessary. We conducted a three-armed unblinded cluster randomized controlled trial (ISRCTN trial registry 83322985). Interventions were a commitment poster (CP) advocating safe antibiotic prescribing or a CP plus an antimicrobial stewardship message (AM) on telephone appointment booking lines, tested against a usual care control group. The primary outcome measure was antibiotic item dispensing rates per 1000 population adjusted for practice demographics. The outcome measures for post-hoc analysis were dispensing rates of antibiotics usually prescribed for upper respiratory tract infections and broad spectrum antibiotics. In total, 196 practice units were randomized to usual care (n = 60), CP (n = 66), and CP&AM (n = 70). There was no effect on the overall dispensing rates for either interventions compared to usual care (CP 5.673, 95%CI −9.768 to 21.113, p = 0.458; CP&AM, −12.575, 95%CI −30.726 to 5.576, p = 0.167). Secondary analysis, which included pooling the data into one model, showed a significant effect of the AM (−18.444, 95%CI −32.596 to −4.292, p = 0.012). Fewer penicillins and macrolides were prescribed in the CP&AM intervention compared to usual care (−12.996, 95% CI −34.585 to −4.913, p = 0.018). Commitment posters did not reduce antibiotic prescribing. An automated patient antimicrobial stewardship message showed effects and requires further testing.

An eleven-year cohort of bloodstream infections in 552 febrile neutropenic patients: resistance profiles of Gram-negative bacteria as a predictor of mortality.

Antimicrobial stewardship is of major importance in patients with febrile neutropenia (FN). In this study, we aimed to investigate the trends in resistance and the relationship with mortality rates in patients with FN. The single-center surveillance data of inpatients with FN and diagnosed as microbiologically confirmed bloodstream infections (BSIs) between 2006 and 2016 were reviewed retrospectively. A total of 950 episodes in 552 patients with BSIs were analyzed. Of whom, 55.9% were male, the median age was 43years, and 35.6% had acute myeloid leukemia. In total, 1016 microorganisms were isolated from blood cultures. Gram-negatives accounted for 42.4% (n = 403) of the episodes. Among Gram-negatives, Enterobacteriaceae accounted for 346 (86%) (E. coli, n = 197; 34% extended-spectrum β-lactamases (ESBL) producers, and Klebsiella spp., n = 120; 48.3% ESBL producers). Also, 24 (20.0%) of Klebsiella spp. had carbapenemase activity. There were 6 (5.0%) colistin-resistant Klebsiella spp. Thirteen (26.5%) of Pseudomonas spp. and 17 (60.7%) of Acinetobacter spp. had carbapenemase activity. There were 2 (5.6%) colistin-resistant Acinetobacter spp. The 30-day mortality rates were 12.0%, 21.5%, 34.6%, and 29.0% in BSIs due to Gram-positive, Gram-negative bacterial, fungal, and polymicrobial etiology respectively (p = 0.001). BSIs with ESBL-producing (p = 0.001) isolates, carbapenem (p < 0.001), and colistin-resistant isolates (p < 0.001) were associated with increased mortality risk. The tremendous rise in resistance rates among Gram-negatives is dreadfully related to increasing mortality and leads to sharp shifts toward extreme restrictions of unnecessary antibiotic uses. Antimicrobial stewardship in patients with FN requires vigilance and tailoring of treatment upon local surveillance data.

72: Antimicrobial stewardship in patients with penicillin allergy undergoing hysterectomy

72: Antimicrobial stewardship in patients with penicillin allergy undergoing hysterectomy

Antimicrobial Stewardship in Patients with Hematological Malignancies: Key Considerations

This review establishes current evidence supporting antimicrobial stewardship programs for malignant hematology and hematopoietic stem cell transplant patients. It describes best practices and identifies opportunities for research. It examines metrics relevant to the patient population, and new approaches to the management of high-risk febrile neutropenia. There is an urgent need for antimicrobial stewardship programs to optimize antimicrobial use in malignant hematology and stem cell transplant patients. Audit and feedback is effective and safe. Febrile neutropenia is a key area to optimize antimicrobial use. Shortening duration of antimicrobial therapy in fever of unknown origin appears to be feasible. Routine antimicrobial prophylaxis has been reexamined. Locally developed guideline for high-risk febrile neutropenia is a major intervention. Antifungal stewardship and rapid diagnostic technologies reduce unnecessary antifungal use. Metrics for antimicrobial stewardship programs in malignant hematology and stem cell transplant are multifaceted. Antimicrobial stewardship in the malignant hematology and stem cell transplant population is feasible, effective, and safe. Current gaps in knowledge include the optimal duration of antimicrobial use in fever of unknown origin, and the safety of targeted therapy despite neutropenia. The ideal human resources requirement is unclear. Cost-effectiveness of antimicrobial stewardship interventions remains to be determined.

Opportunities for antimicrobial stewardship in patients with acute bacterial skin and skin structure infections who are unsuitable for beta-lactam antibiotics: a multicenter prospective observational study.

Purpose:The objective of this prospective, observational study was to describe the treatment, severity assessment and healthcare resources required for management of patients with acute bacterial skin and skin structure infections who were unsuitable for beta-lactam antibiotic treatments.Methods:Patients were enrolled across five secondary care National Health Service hospitals. Eligible patients had a diagnosis of acute bacterial skin and skin structure infection and were considered unsuitable for beta-lactam antibiotics (e.g. confirmed/suspected methicillin-resistant Staphylococcus aureus, beta-lactam allergy). Data regarding diagnosis, severity of the infection, antibiotic treatment and patient management were collected.Results:145 patients with acute bacterial skin and skin structure infection were included; 79% (n = 115) patients received greater than two antibiotic regimens; median length of the first antibiotic regimen was 2 days (interquartile range of 1–5); median time to switch from intravenous to oral antibiotics was 4 days (interquartile range of 3–8, n = 72/107); 25% (n = 10/40) patients with Eron class 1 infection had systemic inflammatory response syndrome, suggesting they were misclassified. A higher proportion of patients with systemic inflammatory response syndrome received treatment in an inpatient setting, and their length of stay was prolonged in comparison with patients without systemic inflammatory response syndrome.Conclusion:There exists an urgent need for more focused antimicrobial stewardship strategies and tools for standardised clinical assessment of acute bacterial skin and skin structure infection severity in patients who are unsuitable for beta-lactam antibiotics. This will lead to optimised antimicrobial treatment strategies and ensure effective healthcare resource utilisation.

Inpatient β-lactam test-dose protocol and antimicrobial stewardship in patients with a history of penicillin allergy

BackgroundPenicillin allergy is the most commonly reported drug allergy in hospitalized patients, resulting in increased second-line antibiotic use, nosocomial infections, and health care use. Given that most patients are not truly allergic, a safe strategy that empowers the admitting physician is needed. ObjectiveTo assess the effect on antibiotic prescribing practices for hospitalized patients with penicillin allergy using a validated intervention. MethodsAn intervention was implemented to educate health care professionals on management of patients with penicillin allergy using a validated risk stratification algorithm to guide testing and antibiotic use. Thirty days of control data using current standard of care was compared with 60 days of postintervention data measuring documentation of penicillin allergy history and antibiotic selection. ResultsThe relative use of cephalosporin and penicillin antibiotics increased by 121.2% (P = .03) and 256% (P = .04), respectively, without an increase in adverse drug reactions. There was a decrease in the use of broad-spectrum antibiotics: vancomycin, 67.2% (P = .04); quinolones, 33.3% (P = .31); carbapenems, 81.9% (P = .08); and aztreonam, 73.8% (P = .18). ConclusionThe antibiotic choice in patients admitted to the hospital with a reported penicillin allergy can be improved by better evaluation of the allergy history and the use of a risk stratification guideline.

Clostridium difficile Infection Among Hospitalized Chronic Hepatitis B Virus-Infected Patients in a Chinese Hospital

Background: Liver disease represents a risk factor for Clostridium difficile infection (CDI). However, CDI predisposition and its incidence in patients with chronic hepatitis B (CHB) have not been well-characterized. Objectives: This study aimed at determining the incidence and risk factors of CDI in CHB patients without cirrhosis. Methods: A retrospective case-control study was conducted on hospitalized patients in a Chinese tertiary hospital between June 2010 and June 2016. Results: A total of 105 CHB patients without cirrhosis were included in the present study. Among these patients, 35 (33%) patients developed hospital-acquired CDI. A total of 35 toxigenic C. difficile strains were assigned to 15 different STs by multi-locus sequence typing (MLST). Multivariate analysis indicated that prolonged hospital stay (OR: 1.045; 95% CI: 1.006 to 1.086) and higher Charlson scores on admission (OR: 3.063; 95% CI: 1.602 to 5.857) were independent factors for the development of CDI among CHB patients without cirrhosis. Conclusions: A high incidence of CDI was detected in this cohort of CHB patients. Both the prolonged hospital stay and higher Charlson scores made CHB patients more susceptible to hospital-acquired CDI. Greater emphasis on infection control measures and antimicrobial stewardship in patients with CHB during hospital admission is needed.

Impact of matrix-assisted laser desorption/ionization time of flight mass spectrometric evaluation on the clinical outcomes of patients with bacteremia and fungemia in clinical settings lacking an antimicrobial stewardship program: a pre-post quasi experimental study

BackgroundsSeveral studies have evaluated the impact of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) combined with antimicrobial stewardship in patients with positive blood cultures; clinical outcomes improved. However, in many hospitals, antimicrobial stewardship is not available because of restricted medical resources. Thus, we investigated the impact of evaluation by MALDI-TOF MS on the clinical outcomes of patients with bacteremia and fungemia treated in a clinical setting lacking an antimicrobial stewardship program (ASP).MethodsWe designed a pre–post quasi experimental study and retrospectively reviewed the medical records of patients aged > 18 years old with bacteremia and fungemia during two periods: October–December 2012 and October–December 2013. Conventional methods were used to detect microbial pathogens in 2012, and MALDI-TOF MS was employed in 2013. Clinical outcomes compared between periods were the time to pathogen identification, time to effective therapy, 30-day all-cause mortality, time to microbiological clearance, length of ICU stay, and rate of recurrence of the same bloodstream infection (BSI).ResultsA total of 556 patients were enrolled; 302 patients in 2012, and 254 in 2013. The use of MALDI-TOF MS without an ASP reduced the time to pathogen identification (86.4 vs. 63.5 h, P < 0.001) but did not significantly reduce the time to effective therapy (27.4 vs. 23.2 h, P = 0.187). Also, none of the following differed significantly between the two periods: mortality (17.5 vs. 15.7%, P = 0.571), the time to microbiological clearance (3.6 vs. 3.7 days, P = 0.675), the length of ICU stay (16.8 vs. 14.7 days, P = 0.706), and the recurrence rate of the same BSI (5.0 vs. 2.8%, P = 0.183).ConclusionsThe use of MALDI-TOF MS alone in a setting lacking an ASP did not afford clinical benefits. An ASP combined with MALDI-TOF MS is necessary to improve clinical outcomes.

Accelerate PhenoTestTM BC Kit Versus Conventional Methods for Identification and Antimicrobial Susceptibility Testing of Gram-Positive Bloodstream Isolates: Potential Implications for Antimicrobial Stewardship.

The Accelerate PhenoTestTM BC kit (AXDX) provides rapid organism identification (ID) and antimicrobial susceptibility testing (AST) results. Its potential role for antimicrobial stewardship is unknown. To compare the diagnostic accuracy of AXDX with conventional methods (CMs) and assess AXDX's potential role for antimicrobial stewardship in patients with Gram-positive bloodstream infections (BSIs). This retrospective cohort study included adults with Staphylococcus aureus or Enterococcus spp BSIs from July 2014 to January 2016 at a tertiary care medical center. Available isolates were tested on AXDX, and ID and AST results from AXDX were compared with those from CMs (VITEK 2 or ETEST). The following antibiotics were assessed for categorical agreement (CA) and essential agreement (EA) between the methods: ampicillin and daptomycin ( Enterococcus spp only), erythromycin and cefoxitin ( S aureus only), linezolid, and vancomycin. Potential role of AXDX for stewardship was assessed via a retrospective audit by infectious diseases clinicians. We included 231 patients with S aureus (n = 112) or Enterococcus spp (n = 119) BSIs, and 106 unique isolates were available for ID and AST performance analyses. Sensitivity and specificity of AXDX for ID were 98.0% and 99.5%, respectively. CA and EA for the tested antibiotics were >97%. In Monte Carlo simulations, AXDX coupled with stewardship personnel (either 24/7 or Monday to Friday) would have allowed unnecessary therapy to be stopped and active/targeted therapy to be started ≥24 hours sooner in >50% of patients. Compared with CMs, AXDX had similar diagnostic accuracy and can potentially optimize therapy sooner in patients with Gram-positive BSIs.