A Baker's Dozen of Top Antimicrobial Stewardship Intervention Publications in 2022

Keeping abreast of the antimicrobial stewardship-related articles published each year is challenging. The Southeastern Research Group Endeavor identified antimicrobial stewardship-related, peer-reviewed literature that detailed an actionable intervention during 2022. The top 13 publications were selected using a modified Delphi technique. These manuscripts were reviewed to highlight actionable interventions used by antimicrobial stewardship programs to capture potentially effective strategies for local implementation.

Epidemiology and treatment of invasive Bartonella spp. infections in the United States

OBJECTIVES

Bartonella spp., renowned for cat-scratch disease, has limited reports of dissemination. Tissue and blood cultures have limitations in detecting this fastidious pathogen. Molecular testing (polymerase chain reaction, PCR) and cell-free DNA have provided an avenue for diagnoses. This retrospective observational multicenter study describes the incidence of disseminated Bartonella spp. and treatment-related outcomes.

METHODS

Inclusion criteria were diagnosis of bartonellosis via diagnosis code, serology testing of blood, polymerase chain reaction (PCR) of blood, 16/18S tests of blood or tissue, cultures of blood or tissue, or cell-free DNA of blood or tissue from January 1, 2014, through September 1, 2021. Exclusions were patients who did not receive treatment, insufficient data on treatment course, absence of dissemination, or retinitis as dissemination.

RESULTS

Patients were primarily male (n = 25, 61.0%), white (n = 28, 68.3%), with mean age of 50 years (SD 14.4), and mean Charlson comorbidity index of 3.5 (SD 2.1). Diagnosis was primarily by serology (n = 34, 82.9%), with Bartonella henselae (n = 40, 97.6%) as the causative pathogen. Treatment was principally doxycycline with rifampin (n = 17, 41.5%). Treatment failure occurred in 16 (39.0%) patients, due to escalation of therapy during treatment (n = 5, 31.3%) or discontinuation of therapy due to an adverse event or tolerability (n = 5, 31.3%).

CONCLUSIONS

In conclusion, this is the largest United States-based cohort of disseminated Bartonella spp. infections to date with a reported 39% treatment failure. This adds to literature supporting obtaining multiple diagnostic tests when Bartonella is suspected and describes treatment options.

Rhabdomyolysis Suspected to be Caused by Eravacycline Therapy: A Case Report

Eravacycline is approved by the U.S. Food and Drug Administration (FDA) for the treatment of complicated intra-abdominal infections. It is a novel, fully synthetic fluorocycline antibiotic belonging to the tetracycline class with a broad-spectrum of activity and an appealing side effect profile. This report describes a 74-year-old female who presented to the hospital with non-ST-elevation myocardial infarction (NSTEMI) requiring coronary artery bypass graft surgery. After surgery, she developed a sternal wound infection that grew multidrug resistant organisms, leading to a much longer than anticipated hospital stay. Eravacycline was eventually added to the antimicrobial regimen for the persistent infection. Shortly after therapy with eravacycline began, the patient started experiencing muscle pain and the creatine phosphokinase (CPK) level was noted to be elevated. Other causes, such as concomitant administration of an HMG-CoA reductase inhibitor, were explored in this case but not thought to be the cause of rhabdomyolysis. The patient's CPK dropped considerably upon discontinuation of the novel antibiotic, and symptoms resolved. The adverse drug event was reported to the drug manufacturer; however, there are no reports up until this time that address a possible relationship between eravacycline administration and the development of rhabdomyolysis.

Assessing clinical cure of empirical piperacillin/tazobactam for ESBL urinary tract infections (ACCEPT-UTI)

Background

Data are limited regarding use of piperacillin/tazobactam for ESBL urinary tract infections (UTIs). The objective of this study was to compare clinical outcomes of patients treated empirically with piperacillin/tazobactam versus carbapenems for ESBL UTIs.

Methods

This retrospective, observational, propensity score-matched study evaluated adults with an ESBL on urine culture. Patients who had UTI symptoms or leukocytosis, and who received a carbapenem or piperacillin/tazobactam empirically for at least 48 h were included. The primary outcome was clinical success within 48 h, defined as resolution of temperature (36-38°C), resolution of symptoms or leukocytosis (WBC <12 × 10³/μL) in the absence of documented symptoms, and the absence of readmission for an ESBL UTI within 6 months. Secondary outcomes included time to clinical resolution, hospital length of stay, and in-hospital and 30 day all-cause mortality.

Results

Overall, 223 patients were included in the full cohort and 200 patients in the matched cohort (piperacillin/tazobactam = 100, carbapenem = 100). Baseline characteristics were similar between the groups. There was no difference in the primary outcome of clinical success between the carbapenem and piperacillin/tazobactam groups (58% versus 56%, respectively; P = 0.76). Additionally, there was no difference in median (IQR) time to clinical resolution [38.9 h (21.5, 50.9 h) versus 40.3 h (27.4, 57.5 h); P = 0.37], in-hospital all-cause mortality (3% versus 3%; P = 1.00), or 30 day all-cause mortality (4% versus 2%; P = 0.68) between the carbapenem and piperacillin/tazobactam groups, respectively.

Conclusions

There was no significant difference in clinical success for patients treated empirically with piperacillin/tazobactam compared with carbapenems for ESBL UTIs.

Residual Infusion Performance Evaluation (RIPE): A Single-Center Evaluation of Residual Volume Post-Intravenous Eravacycline Infusion

Intravenous (IV) drugs are administered through infusion pumps and IV administration sets for patients who are seen in healthcare settings. There are multiple areas of the medication administration process that can influence the amount of a drug a patient receives. For example, IV administration sets that deliver a drug from an infusion bag to a patient vary in terms of length and bore. In addition, fluid manufacturers report that the total acceptable volume range for a 250 mL bag of normal saline can be anywhere from 265 to 285 mL. At the institution chosen for our study, each 50 mg vial of eravacycline is reconstituted using 5 mL of diluent, and the total dose is administered as a 250 mL admixture. This single-center, retrospective, quasi-experimental study evaluated the residual medication volume after the completion of an IV eravacycline infusion in patients admitted during the pre-intervention study period compared to those in the post-intervention study period. The primary outcome of the study was to compare the residual antibiotic volume remaining in the bags following IV infusions of eravacycline before and after the implementation of interventions. The secondary outcomes included the following: comparing the amount of the drug lost in the pre- and post-intervention periods, determining whether the amount of residual volume was affected by nursing shifts (day versus night), and lastly assessing the cost of facility drug waste. On average, approximately 15% of the total bag volume was not infused during the pre-intervention period, which was reduced to less than 5% in the post-intervention period. Clinically, the average estimated amount of eravacycline discarded decreased from 13.5 mg to 4.7 mg in the pre- and post-intervention periods, respectively. Following the statistically significant results of this study, the interventions were expanded at this facility to include all admixed antimicrobials. Further studies are needed to determine the potential clinical impact when patients do not receive complete antibiotic infusions.

Leveling Up: Evaluation of IV v. PO Linezolid Utilization and Cost after an Antimicrobial Stewardship Program Revision of IV to PO Conversion Criteria within a Healthcare System

The CDC’s Core Elements of an Antimicrobial Stewardship Program (ASP) lists intravenous (IV) to oral (PO) conversion as an important pharmacy-based intervention. However, despite the existence of a pharmacist-driven IV to PO conversion protocol, conversion rates within our healthcare system remained low. We aimed to evaluate the impact of a revision to the current conversion protocol on conversion rates, using linezolid as a marker due to its high PO bioavailability and high IV cost. This retrospective, observational study was conducted within a healthcare system composed of five adult acute care facilities. The conversion eligibility criteria were evaluated and revised on 30 November 2021. The pre-intervention period started February 2021 and ended November 2021. The post-intervention period was December 2021 to March 2022. The primary objective of this study was to establish if there was a difference in PO linezolid utilization reported as days of therapy per 1000 days present (DOT/1000 DP) between the pre- and post-intervention periods. IV linezolid utilization and cost savings were investigated as secondary objectives. The average DOT/1000 DP for IV linezolid decreased from 52.1 to 35.4 in the pre- and post-intervention periods, respectively (p < 0.01). Inversely, the average DOT/1000 DP for PO linezolid increased from 38.9 in the pre-intervention to 58.8 for the post-intervention period, p < 0.01. This mirrored an increase in the average percentage of PO use from 42.9 to 62.4% for the pre- and post-intervention periods, respectively (p < 0.01). A system-wide cost savings analysis showed projected total annual cost savings of USD 85,096.09 for the system, with monthly post-intervention savings of USD 7091.34. The pre-intervention average monthly spend on IV linezolid at the academic flagship hospital was USD 17,008.10, which decreased to USD 11,623.57 post-intervention; a 32% reduction. PO linezolid spend pre-intervention was USD 664.97 and increased to USD 965.20 post-intervention. The average monthly spend on IV linezolid for the four non-academic hospitals was USD 946.36 pre-intervention, which decreased to USD 348.99 post-intervention; a 63.1% reduction (p < 0.01). Simultaneously, the average monthly spend for PO linezolid was USD 45.66 pre-intervention and increased to USD 71.19 post-intervention (p = 0.03) This study shows the significant impact that an ASP intervention had on IV to PO conversion rates and subsequent spend. By revising criteria for IV to PO conversion, tracking and reporting results, and educating pharmacists, this led to significantly more PO linezolid use and reduced the overall cost in a large healthcare system.

Nephrotoxicity of Vancomycin in Combination With Beta-Lactam Agents: Ceftolozane-Tazobactam vs Piperacillin-Tazobactam

BACKGROUND

Vancomycin (VAN)-associated acute kidney injury (AKI) is increased when VAN is combined with certain beta-lactams (BLs) such as piperacillin-tazobactam (TZP) but has not been evaluated with ceftolozane-tazobactam (C/T). Our aim was to investigate the AKI incidence of VAN in combination with C/T (VAN/C/T) compared with VAN in combination to TZP (VAN-TZP).

METHODS

We conducted a multicenter, observational, comparative study across the United States. The primary analysis was a composite outcome of AKI and risk, injury, failure, loss, end stage renal disease; Acute Kidney Injury Network; or VAN-induced nephrotoxicity according to the consensus guidelines. Multivariable logistic regression analysis was conducted to adjust for confounding variables and stratified Kaplan-Meir analysis to assess the time to nephrotoxicity between the 2 groups.

RESULTS

We included VAN/C/T (n = 90) and VAN-TZP (n = 284) at an enrollment ratio of 3:1. The primary outcome occurred in 12.2% vs 25.0% in the VAN-C/T and VAN-TZP groups, respectively (P = .011). After adjusting for confounding variables, VAN-TZP was associated with increased odds of AKI compared with VAN-C/T; with an adjusted odds ratio of 3.308 (95% confidence interval, 1.560-6.993). Results of the stratified Kaplan-Meir analysis with log-rank time-to-nephrotoxicity analysis indicate that time to AKI was significantly shorter among patients who received VAN-TZP (P = .004). Cox proportional hazards analysis demonstrated that TZP was consistent with the primary analysis (P = .001).

CONCLUSIONS

Collectively, our results suggest that the AKI is not likely to be related to tazobactam but rather to piperacillin, which is a component in VAN-TZP but not in VAN-C/T.

Can't keep it SECRET: system evaluation of carbapenem restriction against empirical therapy

Objectives

Carbapenems are appealing agents for empirical use given their broad spectrum of activity; however, selective use is vital in minimizing the risk for development of carbapenem-resistant pathogens. We aimed to examine the impact of carbapenem restriction criteria and a pre-authorization process on utilization and cost savings across a health system.

Methods

This retrospective study was conducted across five adult hospitals. The pre-implementation period was 8 February 2020 to 30 April 2020 and the post-implementation period was 8 February 2022 to 30 April 2022. The primary outcome was to compare the number of orders for carbapenems between the study periods for both the intervention and non-intervention hospitals. Secondary outcomes included projected annual cost and an estimated cost-savings evaluation using a stratified analysis for the intervention and non-intervention facilities to account for more resource-limited settings.

Results

The total number of carbapenem orders decreased between study periods at the intervention hospital (246 versus 61, P < 0.01). At the non-intervention hospitals, orders decreased, although not significantly (333 versus 279, P = 0.58). Meropenem orders decreased by 66% compared with 12% for the intervention and the non-intervention hospitals, respectively (P < 0.001). Annual estimated cost for all facilities was $255 561 in the pre-implementation period compared with $29 593 in the post-implementation period (P < 0.001). Using a stratified analysis to account for available resources, the estimated annual cost saving was $225 968 for the system.

Conclusions

Implementation of carbapenem restriction at the intervention hospital decreased utilization and provided significant cost savings. Furthermore, resource-limited facilities can still experience significant cost savings using a stratified antimicrobial stewardship intervention approach.

1017. Residual Infusion Performance Evaluation (RIPE): A Single-Center Evaluation of Residual Volume Post-Intravenous Eravacycline Infusion

Background

Intravenous (IV) fluid manufacturers report an acceptable volume of overfill range for a 250 mL bag of normal saline from 265-285 mL. This overfill can contribute to residual drug that is not administered to patients. Frequent instances of incomplete eravacycline infusions were noticed by infectious disease providers.

Residual Eravacycline Volume Following IV Infusion

Methods

This single-center, retrospective, quasi-experimental study evaluated residual volume after the completion of IV eravacycline infusion in patients admitted during the pre-intervention period (July 1 – 30, 2021) vs. post-intervention period (November 1 – 30, 2021). The intervention (August 1 – October 31, 2021), consisted of updating drug labels to add the drug diluent to total volume and a comment in the administration section to “infuse at current rate until bag is empty.” Nursing education was provided to encourage administration of the entire drug volume. The primary outcome compared residual antibiotic volume before and after implementation of the intervention. The secondary outcomes evaluated amount of drug lost (total mg and percent of total dose) in the pre- and post-intervention periods and cost of facility drug waste.

Nursing Education Distributed During Intervention Period

Results

There was an average residual volume of 38.0 mL (range 6 – 85 mL) for pre-intervention (n=9, total of 46 doses) vs. 12.2 mL (range 0 – 37 mL) for the post-intervention (n=7, total of 21 doses) population (p&lt; 0.0001). Residual volume accounted for an average of 15.2% of the total bag volume compared to 4.7% for the pre- and post-intervention groups, respectively (p&lt; 0.0001). The pre-intervention residual volume contained an average of 13.5 mg (15.3% of total dose) of eravacycline, versus 4.7 mg (4.7% of total dose) in the post-intervention (p&lt; 0.0001). Cost analysis used average wholesale price for 50 mg vials. Residual volume in the pre-intervention period estimated $893.45 ($10,721.40 annualized) vs. $161.04 ($1,932.48 annualized) in the post-intervention period.

Pre- and Post-Intervention Comparison

Clinical Analysis of Residual Antibiotic Volume

Facility Waste

Conclusion

Average residual volume and amount of discarded drug was significantly reduced after the interventions. Following the results of this study, interventions were expanded to all admixed antimicrobials. Further studies are needed to determine the potential clinical impact when patients do not receive the complete antibiotic infusion due to residual volume.

Disclosures

Kerry O. Cleveland, MD, AbbVie: Honoraria|Cumberland: Honoraria|Merck: Honoraria|Pfizer: Honoraria Michael S. Gelfand, MD, AbbVie: Expert Testimony|La Jolla: Expert Testimony.

2231. Assessing Clinical Cure of Empiric Piperacillin-Tazobactam for ESBL Urinary Tract Infections (ACCEPT-UTI)

Background

While literature supports use of carbapenems over piperacillin-tazobactam (TZP) for extended spectrum beta-lactamase (ESBL) bacteremia, data is limited regarding the use of TZP for ESBL urinary tract infections (UTIs). The objective of this study is to determine if patients have similar clinical outcomes when empirically treated with TZP versus carbapenems for ESBL UTIs.

Methods

This IRB-approved, retrospective, non-inferiority study evaluated adult patients admitted to a 5-facility healthcare system from January 1, 2016 to June 30, 2021. Patients who received a carbapenem or TZP empirically for at least 48 hours with a urine culture positive for an ESBL, urinary symptoms or leukocytosis, and isolate susceptibility to the empiric antibiotic of choice were included. The primary outcome was clinical success within 48 hours defined as resolution of temperature (36-38 °C), resolution of symptoms or leukocytosis (WBC &lt; 12 x103/μL) in the absence of symptoms, and the absence of readmission for an ESBL UTI within 6 months. Secondary outcomes included time to clinical success, hospital length of stay (LOS), and 30-day all-cause mortality.

Results

A total of 223 patients were included with 123 (55%) patients receiving TZP and 100 (45%) patients receiving a carbapenem. Patients were predominantly female (65%) and Caucasian (52%) with a median (IQR) age of 70 (58, 81) years. Baseline characteristics were similar between the groups with no difference in complicated cystitis (60%), pyelonephritis (27%), or concomitant bacteremia (25%) (Table 1). There was no difference in the primary outcome of clinical success between the carbapenem and TZP group (60% vs 59%, respectively; p=0.92). Additionally, there was no difference in median (IQR) time to clinical success [39 (21, 52) vs 40 (25, 57) hrs, p=0.53], median hospital LOS [7.0 (5.1, 10.6) vs 6.8 (4.7, 9.2) days, p=0.12], or 30-day all-cause mortality (4% vs 2%, p=0.72) between the carbapenem and TZP groups, respectively (Table 2).

Conclusion

In this large, multi-center study, we found no difference in clinical outcomes in patients with UTIs caused by ESBL-producing organisms treated empirically with TZP versus carbapenems. Clinicians could consider using TZP in patients with ESBL UTIs susceptible to TZP.

Disclosures

Michael S. Gelfand, MD, AbbVie: Expert Testimony|La Jolla: Expert Testimony Kerry O. Cleveland, MD, AbbVie: Honoraria|Cumberland: Honoraria|Merck: Honoraria|Pfizer: Honoraria.

633. Eravacycline Use in Immunocompromised Patients: Multicenter Evaluation of Clinical and Safety Endpoints

Background

Infections caused by multidrug-resistant (MDR) bacteria are an increasingly common public health threat associated with worse outcomes in immunocompromised patients. Eravacycline (ERV) has potent in-vitro activity against MDR Gram-negative and Gram-positive bacteria and has demonstrated non-inferiority to meropenem in the phase III IGNITE4 trial; however, the trial excluded immunocompromised patients. We aimed to evaluate clinical and safety endpoints of immunocompromised patients receiving ERV as definitive therapy.

Methods

Multicenter, retrospective, observational study conducted from October 2018 to April 2022. Adult hospitalized immunocompromised patients treated with ERV for ≥72 hours were included. Immunocompromised patients were defined as having any of the following: chemo or radiation therapy < 30 days of hospital admission, HIV/AIDS with CD4 < 200, chronic steroids ( >40 mg prednisone or equivalent. The primary outcome was 30-day survival. Secondary outcomes were lack of 30-day infection recurrence and drug-related safety events.

Results

Overall, 75 immunocompromised patients treated with ERV were included from 17 United States medical centers. Median (IQR) age was 62 (53-70) and 61.6% were male. Hospital length of stay was 28 (13-42) days and 67% were admitted to the intensive care unit. SOFA and APACHE II scores were 3.5 (1-7) and 16 (11-20), respectively. Common infection sources were intra-abdominal (26%) and lower respiratory tract (18%); 24% were bacteremic. Most patients had cultured Enterobacterales (58.7%) and Enterococci (37%) spp. infections. Of those, 21.3% were CRE and 19% were VRE. Infectious diseases consult was obtained in 91.8% of cases. Time elapsed from index culture collection to ERV initiation was 4 (2-8) days and duration of ERV therapy was 7 (4-12) days. In total, 81.3% of immunocompromised patients achieved 30-day survival and 90.7% did not have 30-day infection recurrence. Probable drug-related adverse events occurred in 5.3% of patients (GI 4%, rash 1%).

Conclusion

A majority of immunocompromised patients receiving ERV as definitive therapy achieved 30-day survival and did not experience infection recurrence. ERV use in immunocompromised subpopulations will benefit from studies tailored to their specific characteristics.

Disclosures

Kimberly C. Claeys, PharmD, BioFire Diagnostics: Honoraria Bruce M. Jones, Pharm.D., FIDSA, BCPS, AbbVie: Advisor/Consultant|AbbVie: Honoraria|La Jolla: Honoraria|Melinta: Advisor/Consultant|Paratek: Honoraria|Regeneron: Honoraria.

920. Leveling Up: Evaluation of IV vs. PO Linezolid Utilization and Cost after an Antimicrobial Stewardship Program Revision of IV to PO Conversion Criteria within a Healthcare System

Background

Intravenous (IV) to oral (PO) conversion is specifically listed as a pharmacy-based intervention in the CDC’s Core Elements of an Antimicrobial Stewardship Program (ASP). Due to linezolid’s high PO availability and high IV cost, it is used as a marker for pharmacist-driven IV to PO conversion within our healthcare system, which remained low despite the existence of a pharmacist-driven IV to PO protocol. The system ASP implemented an intervention aimed at improving rates of IV to PO conversion of antimicrobials.

Methods

This retrospective, observational cohort was conducted within a healthcare system composed of 5 adult acute care facilities. The system ASP reviewed and revised the conversion eligibility criteria November 30, 2021 (Table 1). Education was conducted, and a compulsory computerized training module was assigned to every pharmacist in the system. Two follow-up emails reporting results were also sent to the system ASP pharmacy leaders during the post-intervention period, and leaders were encouraged to share results with their departments. The primary objective of this study was to determine if there was a difference in PO linezolid utilization reported as days of therapy per 1000 patient days (DOT/1000 PD) between the pre- and post-intervention periods. Secondary objectives included IV linezolid utilization and cost savings.

Results

The average DOT/1000 PD for PO linezolid in the pre-intervention period (February-November 2021) was 38.9 compared to 58.8 for the post-intervention period (December 2021-March 2022), p&lt; 0.01 (Figure 1). This reflected an increase in the average percentage of PO use from 42.9 to 62.4% for the pre- and post-intervention periods, respectively (p&lt; 0.01, Figure 2). Inversely, the average DOT/1000 PD for IV linezolid fell from 52.1 to 35.4 in the pre- and post-intervention periods, respectively (p&lt; 0.01). A cost savings analysis revealed a monthly post-intervention savings of $7,091.34 with a projected total annual cost savings of $85,096.09 for the system.

Conclusion

An ASP intervention that revised criteria for IV to PO conversion, educated pharmacists, and tracked and reported results led to significantly more PO linezolid use and reduced overall cost in a large healthcare system.

Disclosures

Kerry O. Cleveland, MD, AbbVIe: Honoraria|Merck: Honoraria.

897. Criteria Restricting Inappropriate Meropenem Empiricism (CRIME): A Quasi-Experimental Carbapenem Restriction Pilot at a Large Academic Medical Center

Background

Carbapenems’ broad spectrum of activity may make these agents appealing for empiric use; however, their use is associated with development of Clostridioides difficile infection (CDI) and multi-drug resistance. Selective use of carbapenems is vital in maintaining their effectiveness. Our study aimed to examine the impact of meropenem restriction criteria on utilization and patient outcomes.

Methods

This single-center, quasi-experimental study was conducted at an academic medical center where an initial medication use analysis found frequent inappropriate meropenem utilization. The antimicrobial stewardship team developed restriction criteria and implemented a pilot in February 2022. Investigators aimed to determine how restriction criteria affected meropenem utilization across 8 weeks in the pre-implementation period compared to the post-implementation period. The primary outcome was to compare the inappropriateness of meropenem utilization. Secondary outcomes included comparison of days of therapy per 1000 patient-days (DOT/1000 PD), hospital length of stay (LOS), frequency of CDI, and acquisition cost.

Results

Across the 8 week timeframes, reductions in inappropriate meropenem use (64.5% vs 12.8%; p&lt; 0.001), duration of therapy (5.8 [3.2-7.3] vs. 2.4 [1.0-5.5] days, p&lt; 0.0001), and utilization (30.5 vs. 8.3 DOT/1000 PD, p=0.04) in the pre- and post-implementation periods, respectively, were observed. Total number of meropenem orders decreased by 65% (p&lt; 0.001). Implementation of restriction criteria also resulted in decreased median hospital LOS between periods (11.9 [7.8-20.4] vs. 9.2 [5.4-15.2] days, p=0.05). There was no difference in frequency of CDI (2 vs. 0, p=0.99). Projected annual cost savings was approximately $57,300.

Conclusion

Implementation of antimicrobial stewardship-initiated restriction criteria can reduce inappropriate utilization of meropenem, overall number of orders, and total duration of therapy.

Disclosures

Kerry O. Cleveland, MD, AbbVie: Honoraria|Cumberland: Honoraria|Merck: Honoraria|Pfizer: Honoraria.

Gut microbiome health and dysbiosis: A clinical primer

The gut microbiome has been referred to as the "forgotten organ." Although much about the gut microbiome remains incompletely understood, data on its clinical importance is emerging at rapid speed. Many practicing clinicians may be unaware of the essential role that the microbiome plays in both health and disease. This review aims to improve clinical understanding of the gut microbiome by discussing key terminology and foundational concepts. The role of a healthy microbiome in normal host function is described, as well as the consequences of a disrupted microbiome (i.e., dysbiosis). Management strategies to restore the gut microbiome from a disrupted to a healthy state are also briefly discussed. Lastly, we review emerging areas for therapeutic potential and opportunity to bring determinants of microbiome health from the bench to bedside.

Clinical Outcomes of Eravacycline in Patients Treated Predominately for Carbapenem-Resistant Acinetobacter baumannii

Forty-six patients were treated with eravacycline (ERV) for Acinetobacter baumannii infections, where 69.5% of isolates were carbapenem resistant (CRAB). Infections were primarily pulmonary (58.3%), and most patients received combination therapy (84.4%). The median (IQR) ERV duration was 6.9 days (5.1 to 11.1). Thirty-day mortality was 23.9% in the cohort and 21.9% in CRAB patients. One patient experienced an ERV-possible adverse event. IMPORTANCE Acinetobacter baumannii, particularly when carbapenem resistant (CRAB), is one of the most challenging pathogens in the health care setting. This is complicated by the fact that there is no consensus guideline regarding management of A. baumannii infections. However, the recent Infectious Diseases Society of America guidelines for treatment of resistant Gram-negative infections provided expert recommendations for CRAB management. The panel suggest using minocycline among tetracycline derivatives rather than eravacycline (ERV) until sufficient clinical data are available. Therefore, we present the largest multicenter real-world cohort in patients treated with ERV for A. baumannii, where the majority of isolates were CRAB (69.5%). Our analysis demonstrate that patients treated with ERV-based regimens achieved a 30-day mortality of 23.9% and had a low incidence of ERV-possible adverse events (2.1%). This study is important as it fills the gap in the literature regarding the use of a novel tetracycline (i.e., ERV) in the treatment of this challenging health care infection.

Criteria Restricting Inappropriate Meropenem Empiricism (CRIME): a quasi-experimental carbapenem restriction pilot at a large academic medical centre

The broad-spectrum activity of carbapenems makes them appealing for empirical use; however, they are associated with development of Clostridioides difficile infection (CDI) and multidrug resistance. Selective carbapenem use is vital in maintaining their effectiveness. We examined the impact of meropenem restriction criteria on utilisation and patient outcomes. This quasi-experimental study was conducted at a single academic medical centre after medication use evaluation found frequent inappropriate meropenem utilisation. Antimicrobial stewardship-led restriction criteria were developed and implemented in February 2022. Investigators aimed to determine how restriction criteria affected meropenem utilisation across 8 weeks in the pre- (February-April 2020) versus post-implementation period (February-April 2022). The primary outcome was inappropriateness of meropenem utilisation. Secondary outcomes included days of therapy per 1000 patient-days (DOT/1000 PD), hospital length of stay (LOS), CDI Standardized Infection Ratio (SIR), and acquisition cost. Across the 8-week timeframes, reductions in inappropriate meropenem use (64.5% vs. 12.8%; P < 0.001), duration of therapy [5.8 (3.2-7.3) vs. 2.4 (1.0-5.5) days; P < 0.001] and utilisation (30.5 vs. 8.3 DOT/1000 PD; P < 0.001) pre- versus post-implementation were observed. Total meropenem orders decreased by 65% (P < 0.001). Median hospital LOS also decreased between periods [11.9 (7.8-20.4) vs. 9.2 (5.4-15.2) days], although not statistically significant (P = 0.051). There was no difference in CDI SIR (0.1 vs. 0.1; P = 0.99). Projected annual cost savings were ∼US$57 300. Implementation of antimicrobial stewardship-initiated restriction criteria can reduce inappropriate meropenem utilisation, overall number of orders, and total duration of therapy.

Successful treatment of disseminated Verruconis gallopava infection in a heart transplant recipient: A case report

DISCLAIMER

In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

To describe a case of disseminated Verruconis gallopava infection in a cardiac transplant recipient that was successfully treated with oral posaconazole and intravenous anidulafungin.

SUMMARY

A 51-year-old male initially presented with pulmonary manifestations, but subsequently developed cutaneous lesions, fungemia, osteomyelitis of the hip requiring excision, and eventually brain abscesses over the course of 3 months. The patient was successfully treated with various antifungal agents throughout his treatment course and was eventually discharged on oral posaconazole and intravenous anidulafungin. He remained on oral posaconazole suppressive therapy and had had no recurrence of fungal infection after 31 months of follow-up.

CONCLUSION

On the basis of this case report, intravenous anidulafungin and chronic suppressive therapy with oral posaconazole can successfully treat disseminated V. gallopava infections.

Evaluation of the timing of MRSA PCR nasal screening: How long can a negative assay be used to rule out MRSA-positive respiratory cultures?

PURPOSE

Previous studies indicate that the polymerase chain reaction (PCR) nasal assay for methicillin-resistant Staphylococcus aureus (MRSA) has a consistently high (>95%) negative predictive value (NPV) in ruling out MRSA pneumonia; however, optimal timing of PCR assay specimen and respiratory culture collection is unclear.

METHODS

A study including 736 patients from a community hospital system was conducted. Patients were included if they had undergone MRSA nasal screening with a PCR assay and had documented positive respiratory culture results.

RESULTS

In the full cohort, the MRSA PCR nasal screen assay was demonstrated to have an NPV of 94.9% (95% confidence interval [CI], 92.8%-96.5%) in ruling out MRSA-positive respiratory cultures. When evaluating the NPV by level of care (ie, where the MRSA PCR nasal assay sample was collected), no significant difference between values for samples collected in an intensive care unit vs medical/surgical units was identified (NPV [95%CI], 94.9% [92.7%-96.6%] vs 95.3% [88.4%-98.7%]). Additionally, NPV remained high with use of both invasive (NPV [95%CI], 96.8% [92.7%-99.0%]) and noninvasive (NPV [95%CI], 94.5% [91.7%-96.2%]) respiratory sampling methods. Finally, when evaluating the effect of time between MRSA PCR nasal screening and respiratory sample collection, we found high NPVs for all evaluated timeframes: within 24 hours, 93.8% (90.1%-96.4%); within 25 to 48 hours, 98.6% (92.7%-100.0%); within 49 hours to 7 days, 95.7% (91.4%-98.3%); within 8 to 14 days, 92.9% (85.1%-97.3%); and after more than 14 days, 95.5% (84.5%-99.4%).

CONCLUSION

We report high NPVs for up to 2 weeks between specimen collections, which allows clinicians to use a negative MRSA PCR nasal screen assay to rule out MRSA pneumonia, potentially leading to decreased exposure to MRSA-active antibiotics.

1577. Real-World, Multicenter Experience with Eravacycline for Various Infections

Background

Eravacycline (ERV) is Food and Drug Administration approved in patients for the treatment of adults complicated intra-abdominal infections in 2018. Real-world data regarding the indications for ERV use are is limited. We evaluated the clinical/safety outcomes of patients treated with ERV in FDA and non-FDA approved indications.

Methods

Multicenter, retrospective, observational study from September 2018 to June 2020. Adult patients treated with ERV for ³ 72 hours were included. The primary outcome was 30-day survival. Secondary outcomes included a lack of 30-day infection-recurrence, resolution of signs/symptoms of infection and safety. All outcomes were measured from ERV start date.

Results

Overall, 108 patients were included from 12 geographically-distinct medical centers across the United States. The median(IQR) age was 60(52-67) years and 60% were male. Median(IQR) APACHE II and Charlson Comorbidity scores were 15(11-21) and 3 (2-6), respectively. The most common sources of infection were intra-abdominal (32%), and respiratory (24%). Common pathogens included Acinetobacter baumannii (19%), Klebsiella pneumoniae and Enterococcus faecium (16%). Infectious diseases consultation was obtained in 98%, and surgical interventions in 51% of cases. Patients often received active therapy prior to ERV(40%). Median(IQR) ERV therapy duration was 7.7(4.4-14.0) days. Among cases with documented cultures, ERV was initiated within a median(IQR) of 4.8(2.5-9.9) days. Combination therapy ³ 48 hours was given in 45%. The primary endpoint was achieved in 79%(85/108). Of patients who died(n=23), 57% were on monotherapy, 39% were critically ill, 39% had intra-abdominal as a source, and 30% had positive blood cultures. For secondary outcomes, 94%(102/108) lacked 30-day infection-recurrence and 74%(80/108) resolved signs/symptoms of infection. ERV was selected primarily for consolidation of the regimen(40%). Eight patients experienced a probable ERV-related adverse event, mainly gastrointestinal(87.5%) and none experienced clostridium difficile.

Conclusion

30-day survival was achieved in the majority of patients treated with ERV. Studies with longer follow-up are required to confirm these findings.

Disclosures

Madeline King, PharmD, Tetraphase (Speaker’s Bureau) Bruce M. Jones, PharmD, BCPS, ALK-Abello (Research Grant or Support)Allergan/Abbvie (Speaker’s Bureau) Michael J. Rybak, PharmD, MPH, PhD, Paratek (Grant/Research Support)

The Pharmacodynamics of Prolonged Infusion β-Lactams for the Treatment of Pseudomonas aeruginosa Infections: A Systematic Review

PURPOSE

Pseudomonas aeruginosa is a commonly isolated nosocomial pathogen for which treatment options are often limited for multidrug-resistant isolates. In addition to newer available antimicrobial agents active against P. aeruginosa, strategies such as extended (eg, prolonged or continuous) infusion have been suggested to optimize the pharmacokinetic and pharmacodynamic profiles of β-lactams. Literature regarding clinical outcomes for extended infusion β-lactams has been controversial; however, this use seems most beneficial in patients with severe illness. Prolonged infusion of β-lactams (eg, 3- to 4-hour infusion) can enhance the pharmacodynamic target attainment via increasing the amount of time throughout the dosing interval to which the free drug concentration remains above the MIC (minimum inhibitory concentration) of the organism (fT > MIC). This systematic review summarizes current literature related to the probability of target attainment (PTA) of various antipseudomonal β-lactam regimens administered as prolonged infusions in an effort to provide guidance in selecting optimal dosing regimens and infusion times for the treatment of P. aeruginosa infections.

METHODS

A literature search for all pertinent studies was performed by using the PubMed database (with no year limit) through March 31, 2019.

FINDINGS

Thirty-nine studies were included. Although many standard antipseudomonal β-lactam intermittent infusion regimens can provide adequate PTA against most susceptible isolates, prolonged infusion may enhance percent fT > MIC for organisms with higher MICs (eg, nonsusceptible) or patients with altered pharmacokinetic profiles (eg, obese, critically ill, those with febrile neutropenia).

IMPLICATIONS

Prolonged infusion β-lactam regimens can enhance PTA against nonsusceptible P. aeruginosa isolates and may provide a potential therapeutic option for multidrug-resistant infections. Before implementing prolonged infusion antipseudomonal β-lactams, institutions should consider the half-life of the antibiotic, local incidence of P. aeruginosa infections, antibiotic MIC distributions or MICs isolated from individual patients, individual patient characteristics that may alter pharmacokinetic variables, and PTA (eg, critically ill), as well as implementation challenges.

2157. Evaluation of the Utility of the MRSA Nasal PCR Assay in a Community Healthcare System

Background

The MRSA nasal PCR assay is a rapid, noninvasive test that has demonstrated a strong negative predictive value (NPV), as high as 99%, for ruling out MRSA pneumonia. These findings are based primarily on literature from large academic centers, which have evaluated both the positive predictive value (PPV) and NPV of MRSA nasal PCR assays. Investigators sought to assess the NPV of the MRSA nasal PCR assay to rule out MRSA pneumonia within a community healthcare system. To the best of our knowledge, this is the largest study from a community hospital and the only study from a community healthcare system for the utilization of a nasal PCR assay to rule out MRSA pneumonia.

Methods

This is a multicenter, retrospective study of adult patients with both an MRSA nasal PCR assay and positive respiratory culture (sputum, bronchoalveolar lavage, or endotracheal aspirate). Data were collected from September 2014 through August 2015 at three community hospitals (bed size ranging from 328 to 706) across two states within a healthcare system. The study was approved by the Baptist Memorial Hospital Institutional Review Board. PPV and NPV 95% confidence intervals (95% CI) were calculated as previously described in the literature.

Results

A total of 808 patients were included in the analysis across the three hospitals. The total incidence of MRSA in positive sputum samples was 14.9% across the three facilities. Our study demonstrated an overall NPV of 95.1% (93.2, 96.6%) and a PPV of 65.9% (95% CI 57.2, 73.9%). The high NPV was retained despite unit type, resulting in 94.9% (95% CI 92.7, 96.6%), 96.3% (95% CI 90.8, 99.0%), and 94.7% (95% CI 74.0, 99.9%) for the intensive care units (ICU), medical-surgical units, and the emergency department, respectively (Table 1).

Conclusion

We concluded that the high NPV of a negative MRSA nasal PCR assay to rule out MRSA pneumonia persisted within a community hospital system. With the results of our study, we plan to utilize institution-specific data along with previously published literature to encourage earlier discontinuation of anti-MRSA antibiotics in patients being treated for pneumonia with negative MRSA nasal PCR assays. Our study demonstrates the validity of the assay in the large community hospital setting with similar findings to studies at large academic institutions.

Disclosures

All authors: No reported disclosures.

965. The Efficacy of Oral Β-lactam Antibiotics as Step-down Therapy for Acute Pyelonephritis

Background

Often, oral β-lactams have been avoided for the treatment of pyelonephritis due to data suggesting lower efficacy vs. currently recommended therapy. However, increasing resistance and concerns for collateral damage of primarily recommended oral agents have increased interest in the use of oral β-lactams for the treatment of pyelonephritis. Authors sought to assess the impact of oral step-down β-lactam therapy compared with an alternative oral agent (fluoroquinolone or trimethoprim-sulfamethoxazole) in patients with acute pyelonephritis requiring hospitalization.

Methods

This is an IRB-approved, multicenter, retrospective study of hospitalized patients with acute pyelonephritis in six hospitals within two healthcare systems who received an IV cephalosporin followed by step-down therapy with either a β-lactam or an alternative agent (i.e., fluoroquinolone or trimethoprim-sulfamethoxazole). We theorize that oral β-lactams are noninferior to alternative oral agents for step-down therapy for pyelonephritis requiring hospitalization. Treatment success was defined as lack of 30-day urinary system-related re-admission. We calculated that 89 patients were required in each group to achieve 80% power with a noninferiority margin of 15% and assuming a cure rate of 85% as reported in previous literature.

Results

A total of 188 patients were included in the study; 115 and 73 who received an oral β-lactam and an alternative oral agent, respectively. There was no difference in treatment success when comparing the two groups (113 [98%] vs. 70 [96%]; P = 0.38). The mean length of hospital stay, number of patients treated with ceftriaxone inpatient, and the duration of IV therapy was the same in both groups, though mean duration of oral therapy was longer in the oral alternative group compared with the oral β-lactam group (9.5 [+ 3.7] vs. 8.2 [+ 2.7] days, respectively; P = 0.02). Baseline characteristics other than mean age were the same, as reported in Table 1.

Conclusion

When using 30-day urinary system-related readmission as a surrogate for treatment success, we found no difference between β-lactams vs. alternative agents for oral step down therapy for pyelonephritis requiring hospitalization.

Disclosures

All Authors: No reported Disclosures.

Patient preferences for treatment of acute bacterial skin and skin structure infections in the emergency department

Background

Limited research has assessed patient preferences for treatment disposition and antibiotic therapy of acute bacterial skin and skin structure infection (ABSSSI) in the emergency department (ED). Understanding patient preference for the treatment of ABSSSI may influence treatment selection and improve satisfaction.

Methods

A survey was conducted across 6 US hospital EDs. Patients with ABSSSI completed a baseline survey assessing preferences for antibiotic therapy (intravenous versus oral) and treatment location. A follow-up survey was conducted within 30–40 days after ED discharge to reassess preferences and determine satisfaction with care.

Results

A total of 94 patients completed both baseline and follow-up surveys. Sixty (63.8%) participants had a history of ABSSSI, and 69 (73.4%) were admitted to the hospital. Treatment at home was the most common preference reported on baseline and follow-up surveys. Patients with higher education were 82.2% less likely to prefer treatment in the hospital. Single dose intravenous therapy was the most commonly preferred antibiotic regimen on baseline and follow-up surveys (39.8 and 19.1%, respectively). Median satisfaction scores for care in the ED, hospital, home, and with overall antibiotic therapy were all 8 out of a maximum of 10.

Conclusions

In these patients, the most common preference was for outpatient care and single dose intravenous antibiotics. Patient characteristics including higher education, younger age, and current employment were associated with these preferences. Opportunities exist for improving ABSSSI care and satisfaction rates by engaging patients and offering multiple treatment choices.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3751-0) contains supplementary material, which is available to authorized users.

1791. The Impact of a β-lactam Allergy Assessment on Aztreonam Utilization Within a Healthcare System

Background

Penicillin allergies are the most commonly reported drug allergies and are documented in up to 17% of patients. Incomplete reaction histories and exaggerated concerns regarding the risk of cross-reactivity often leads to unnecessary avoidance of β-lactams in patients with reported allergies. Utilization of alternative non-β-lactam therapy in patients with reported allergies has been associated with increased incidence of multidrug-resistant organisms, including C. difficile infection. Per the Infectious Diseases Society of America guidelines for implementing an antibiotic stewardship program (ASP), ASPs should promote allergy assessments and penicillin skin testing in patients with a history of a β-lactam allergy. Implementation of penicillin skin testing in the acute care setting is often limited by the education, skill, and time required in administering and interpreting the result. Investigators sought to assess the impact of a β-lactam allergy assessment on aztreonam utilization within a healthcare system.

Methods

This is a multicenter, retrospective study comparing aztreonam utilization in five hospitals within a healthcare system after implementation of a β-lactam allergy assessment. The program included education as well as development of criteria for utilization and a β-lactam allergy assessment algorithm. A β-lactam allergy assessment was performed on any patient with an order for aztreonam. The Mann–Whitney U test was used to assess the impact of the restriction program on aztreonam utilization and expenditure.

Results

The hospital system experienced roughly a 50% decrease in aztreonam days of therapy per 1,000 patient-days [P < 0.01] and 67% reduction in annual expenditure [P < 0.05]. Of the 204 patients with an order for aztreonam, 151 (74%) patients received at least one dose; however, 97 (48%) patients ultimately received and tolerated a β-lactam. Only 112 (55%) patients had a prior reported reaction with 68 (61%) of those having a history of a Type I reaction.

Conclusion

Implementation of a β-lactam allergy assessment for patients with reported allergies can enhance appropriate use of β-lactams and result in reduced aztreonam utilization and expenditure.

Disclosures

All authors: No reported disclosures.

Variability in Emergency Medicine Provider Decisions on Hospital Admission and Antibiotic Treatment in a Survey Study for Acute Bacterial Skin and Skin Structure Infections: Opportunities for Antimicrobial Stewardship Education

Background

Acute bacterial skin and skin structure infections (ABSSSIs) are a frequent cause of emergency department (ED) visits. Providers in the ED have many decisions to make during the initial treatment of ABSSSI. There are limited data on the patient factors that influence these provider decisions.

Methods

An anonymous survey was administered to providers at 6 EDs across the United States. The survey presented patient cases with ABSSSIs ≥75 cm² and escalating clinical scenarios including relapse, controlled diabetes, and sepsis. For each case, participants were queried on their decision for admission vs discharge and antibiotic therapy (intravenous, oral, or both) and to rank the factors that influenced their antibiotic decision.

Results

The survey was completed by 130 providers. For simple ABSSSI, the majority of providers chose an oral antibiotic and discharged patients home. The presence of recurrence or controlled diabetes resulted in more variation in responses. Thirty-four (40%) and 51 (60%) providers chose intravenous followed by oral antibiotics and discharged the recurrence and diabetes cases, respectively. Presentation with sepsis resulted in initiation with intravenous antibiotics (122, 95.3%) and admission (125, 96.1%) in most responses.

Conclusions

Variability in responses to certain patient scenarios suggests opportunities for education of providers in the ED and the development of an ABSSSI clinical pathway to help guide treatment.

Evaluating the Impact of the Addition of Cladribine to Standard Acute Myeloid Leukemia Induction Therapy

BACKGROUND

Treatment for acute myeloid leukemia (AML) has remained relatively unchanged over the past few decades. Although recent drug approvals have provided an increase in the number of treatment options in AML, further optimization of standard induction therapy is still necessary. The most commonly utilized induction options have been well studied, but there is a paucity of literature comparing the combination of idarubicin with cytarabine and cladribine.

OBJECTIVE

To assess the clinical effectiveness of the addition of cladribine to idarubicin and cytarabine (7+3 IA) induction therapy in the treatment of AML.

METHODS

This retrospective, propensity score-matched cohort study evaluated 37 patients with previously untreated AML who received either 7+3 IA or idarubicin, cytarabine, and cladribine (7+3+5 IAC) as induction therapy. The primary end point of this study was complete response (CR), with secondary end points including hospital length of stay (LOS), and adverse event rates.

RESULTS

After propensity score matching, odds of reaching CR in the 7+3+5 IAC cohort were increased by 33% (95% CI = 1.09-1.55; P < 0.01) compared with the 7+3 IA cohort. Patients who received cladribine were also found to have a reduction in hospital LOS by 3.5 days (95% CI = 0.07-6.85; P = 0.045) without an increase in adverse event rates.

CONCLUSION

The addition of cladribine to the 7+3 IA regimen may improve clinical outcomes when used as initial induction therapy, without increasing the incidence of adverse event rates.

Are first-generation cephalosporins obsolete? A retrospective, non-inferiority, cohort study comparing empirical therapy with cefazolin versus ceftriaxone for acute pyelonephritis in hospitalized patients

OBJECTIVES

Literature is lacking regarding the utilization of first-generation cephalosporins for the treatment of acute pyelonephritis. The aim of this study was to determine whether cefazolin is non-inferior to ceftriaxone for the empirical treatment of acute pyelonephritis in hospitalized patients. The primary outcome included a composite of symptomatic resolution plus either defervescence at 72 h or normalization of serum white blood cell count at 72 h (non-inferiority margin 15%). Secondary outcomes included length of stay and 30 day readmission. A subgroup analysis of the composite outcome was also conducted for imaging-confirmed pyelonephritis.

METHODS

This was a retrospective, non-inferiority, multicentre, cohort study comparing cefazolin versus ceftriaxone for the empirical treatment of acute pyelonephritis in hospitalized patients.

RESULTS

Overall, 184 patients received one of the two treatments between July 2009 and March 2015. The composite outcome was achieved in 80/92 (87.0%) in the cefazolin group versus 79/92 (85.9%) in the ceftriaxone group (absolute difference 1.1%, 95% CI -11.1% to 8.9%, P = 0.83), meeting the pre-defined criteria for non-inferiority. The composite outcome for patients with imaging-confirmed pyelonephritis was achieved in 46/56 (82.1%) versus 42/50 (84.0%) for the cefazolin group and the ceftriaxone group, respectively (absolute difference 1.9%, 95% CI -12.8% to 16.5%, P = 0.80). Additionally, there were no statistically significant differences in length of stay or 30 day readmission for cystitis or pyelonephritis.

CONCLUSIONS

Cefazolin was non-inferior to ceftriaxone with regard to clinical response for the treatment of hospitalized patients with acute pyelonephritis in this study. No difference was observed for length of stay or 30 day readmission.