Implementation of an Automated Antibiotic Time-out at a Comprehensive Cancer Center.

Background: Antimicrobial stewardship programs can optimize antimicrobial use and have been federally mandated in all hospitals. However, best stewardship practices in immunocompromised patients with cancer are not well established. Methods: An antimicrobial time out, in the form of an email, was sent to physicians caring for hospitalized patients reaching 5 days of therapy for targeted antimicrobials (daptomycin, linezolid, tigecycline, vancomycin, imipenem/cilastatin, meropenem) in a comprehensive cancer center. Physicians were to discontinue the antimicrobial if unnecessary or document a rationale for continuation. This is a quasi-experimental, interrupted time series analysis assessing antimicrobial use during the following times: period 1 (before time-out: January 2007-June 2010) and period 2 (after time-out: July 2010-March/2015). The primary antimicrobial consumption metric was mean duration of therapy. Days of therapy per 1000 patient-days were also assessed. Results: Implementation of the time-out was associated with a significant decrease in mean duration of therapy for the following antimicrobials; daptomycin: -0.89 days (95% confidence interval [CI], -1.38 to -.41); linezolid: -0.89 days (95% CI, -1.27 to -.52); meropenem: -0.97 days (95% CI, -1.39 to -.56); tigecycline: -1.41 days (95% CI, -2.19 to -.63); P < .001 for each comparison. Days of therapy/1000 patient-days decreased significantly for meropenem (-43.49; 95% CI, -58.61 to -28.37; P < .001), tigecycline (-35.47; 95% CI, -44.94 to -26.00; P < .001), and daptomycin (-9.47; 95% CI, -15.25 to -3.68; P = .002). Discussion: A passive day 5 time-out was associated with reduction in targeted antibiotic use in a cancer center and could potentially be successfully adopted to several settings and electronic health records.

The growing threat of NDM-producing E. coli with penicillin-binding protein 3 mutations in the United States - is there a potential role for durlobactam?

We report identification of 5 patients with infections caused by NDM-5-producing E. coli harboring PBP3 mutations that showed reduced susceptibility to aztreonam-avibactam and cefiderocol. Durlobactam, a novel diazabicyclooctane ß-lactamase inhibitor, demonstrated minimum inhibitory concentrations ranging from 0.5 to 2 µg/mL supporting future investigations into a potential role in clinical management.

Clinical outcomes and frequency of persistent infection among immunosuppressed patients treated with bebtelovimab for COVID-19 infection at an ambulatory cancer center.

BACKGROUND: There are limited data on clinical outcomes associated with the use of bebtelovimab for the treatment of coronavirus disease 2019 (COVID-19) among cancer patients. We aimed to define the clinical characteristics and outcomes among patients receiving bebtelovimab as part of the COVID-19 therapeutics program at our cancer center. METHODS: This is a retrospective cohort study of immunosuppressed adult patients who received bebtelovimab at Fred Hutchinson Cancer Center between March 2022, and November 2022. We reviewed medical records to capture the date of the first positive COVID-19 test, clinical characteristics, outcomes, and follow-up COVID-19 testing for 60 days after the first positive. Persistent infection was defined as a positive test beyond day 30; these patients were reviewed beyond day 60. RESULTS: Among 93 patients who received bebtelovimab, 64 (69%) had hematologic malignancy. Sixty-nine (74%) patients received bebtelovimab within 2 days after diagnosis. Two (2%) patients were hospitalized, none required ICU care, and one patient died on day 52; although it is unknown if death was directly related to COVID-19. Ten (11%) patients had persistent COVID-19 infection; of these, four received additional COVID-19 therapy with either nirmatrelvir/ritonavir or remdesivir, and five out of six patients with sequencing data available had spike protein mutations associated with bebtelovimab resistance. CONCLUSION: A coordinated systems-based approach led to prompt initiation of bebtelovimab within two days of testing positive in most patients. We observed few hospitalizations or deaths. Persistent infection was noted in 11% of patients with four requiring additional therapies, highlighting a need for novel strategies to manage immunosuppressed patients.

Analysis of health care facility-onset Clostridioides difficile infection (CDI) in a hematopoietic cell transplant (HCT) unit: A call for diagnostic stewardship in a complex patient population.

Nearly half the patients identified as having health care facility-onset Clostridioides difficile infections on a hematopoietic cell transplant unit had an alternative clinical explanation for diarrhea, including conditioning regimen toxicity or other medications. Our study supports that targeted diagnostic stewardship interventions should be explored and that additional risk-adjustments considered for facilities with oncology hematopoietic cell transplant wards in the National Healthcare Safety Network LabID Clostridioides difficile infection standardized infection ratio model.

Antimicrobials in patients with hematologic malignancies and recipients of hematopoietic cell transplantation and other cellular therapies.

BACKGROUND: Appropriate use of antimicrobials for hematologic malignancy, hematopoietic stem cell transplant recipients, and other cellular therapies is vital, with infection causing significant morbidity and mortality in this unique population of immunocompromised hosts. However, often in this population the choice and management of antimicrobial therapy is complex. When selecting an antimicrobial agent, key considerations include the need for dose adjustments due to renal or hepatic impairment, managing drug interactions, the potential for additive drug toxicity among those receiving polypharmacy and therapeutic drug monitoring. Other factors include leveraging pharmacodynamic principles to enable optimization of directed therapy against challenging pathogens, as well as judicious use of antimicrobials to limit drug resistance and adverse drug reactions. SUMMARY: This review summarizes the clinical considerations for commonly used antimicrobials in this setting, including antibacterial, antiviral, and antifungal agents.

Successful Treatment of Persistent Symptomatic Coronavirus Disease 19 Infection With Extended-Duration Nirmatrelvir-Ritonavir Among Outpatients With Hematologic Cancer.

Persistent symptomatic coronavirus disease 2019 (COVID-19) is a distinct clinical entity among patients with hematologic cancer and/or profound immunosuppression. The optimal medical management is unknown. We describe 2 patients who had symptomatic COVID-19 for almost 6 months and were successfully treated in the ambulatory setting with extended courses of nirmatrelvir-ritonavir.

Antiviral Prescribing Among Patients at an Ambulatory Cancer Center With Laboratory-Confirmed Influenza.

Among 133 cancer outpatients diagnosed with influenza between 2016 and 2018, 110 (83%) were prescribed oseltamivir. Among 109 with a known symptom onset date, 53% presented for care and 31% were prescribed oseltamivir within 48 hours. Patient/provider education and rapid diagnostics are needed to improve early oseltamivir use among cancer patients with influenza.

Aminoglycoside Pharmacokinetics in Critically Ill Patients Undergoing Continuous Renal Replacement Therapy.

BACKGROUND: There are few studies describing aminoglycoside pharmacokinetics during continuous renal replacement therapy (CRRT). OBJECTIVE: To characterize the effect of CRRT on aminoglycoside clearance and volume of distribution (Vd). METHODS: Retrospective observational pharmacokinetic study of adult critically ill oncologic patients who received a first dose of amikacin or tobramycin during CRRT between February 2012 and May 2017. Study outcomes included aminoglycoside clearance, Vd, and attainment of the target peak: MIC (minimum inhibitory concentration) ratio as a surrogate for dosing appropriateness. RESULTS: In total, 80 patients were included, sustained low-efficiency dialysis (SLED), n = 49; continuous venovenous hemodialysis (CVVHD), n = 19; continuous venovenous hemofiltration (CVVH), n = 12. Fifty-one patients received amikacin at a median dose of 14.5 mg/kg per actual body weight and achieved a median peak level of 26.7 mg/L. Twenty-nine patients received tobramycin at a median dose of 6.5 mg/kg actual body weight and achieved a median peak level of 10.3 mg/L. The median aminoglycoside clearance was 63.1 mL/min and was similar between CRRT modality groups (P = 0.97). The median Vd was 0.47 L/kg and was different between the SLED and CVVH groups (P = 0.007). Attainment of target peak: MIC occurred in 29% in the total study population and 44% in the subgroup of 23 patients with isolates tested for aminoglycoside susceptibility. CONCLUSION AND RELEVANCE: Critically ill oncology patients undergoing CRRT exhibited reduced clearance and expanded Vd that was not significantly different between CRRT modalities. Current dosing regimens led to low peak concentrations and poor attainment of pharmacokinetic targets.

Voriconazole in Hematopoietic Stem Cell Transplantation and Cellular Therapies: Real-World Usage and Therapeutic Level Attainment at a Major Transplantation Center.

Voriconazole (VCZ) was one of the first mold-active triazoles available; however, its current use among high-risk hematology populations is unknown as the uptake of posaconazole (PCZ) and isavuconazole (ISZ) increases. We evaluated the usage and therapeutic level attainment of VCZ in hematopoietic cell transplantation (HCT) and chimeric antigen receptor T cell (CAR-T) therapy patients at our cancer center. Electronic medical records for all adult HCT or CAR-T patients with an order for VCZ, PCZ, or ISV between January 1, 2018, and June 30, 2020, were extracted. Clinical characteristics, VCZ indication, trough VCZ levels, and frequency of VCZ initiation from 6 months before to 6 months after HCT/CAR-T infusion in consecutive HCT/CAR-T recipients within the study period (infusion between July 1, 2018, and January 1, 2020) were assessed. The association between relevant clinical characteristics and the attainment of subtherapeutic or supratherapeutic levels was also evaluated. Of 468 patients prescribed mold-active triazoles, 256 (54.7%) were prescribed VCZ, 324 (69.2%) PCZ, and 60 (12.8%) ISZ; 152/468 (32.5%) treatment regimens were sequentially modified to alternate mold-active triazoles. Among consecutive HCT and CAR-T recipients at our center, evaluated 6 months pre- or post- HCT/ CAR-T, VCZ was commonly initiated before or after allogeneic HCT (102/381, 26.8%), with most use in the first 30 days after stem cell infusion (40/381, 10.5%); VCZ use was less common in autologous HCT (13/276, 4.7%) and CAR-T (10/153, 6.5%). Of 223 VCZ orders that met inclusion for analysis, indications included empiric treatment in 108/223 (48.4%), directed therapy in 25/223 (11.2%), primary prophylaxis in 69/223 (30.9%) and secondary prophylaxis in 21/223 (9.4%). Of 223 eligible VCZ patients, 144 (64.6%) had at least 1 VCZ level measured during the study period; 75/144 (52.1%) had a therapeutic VCZ level (1.0-5.5 mg/L) at the first measurement (median 2.8mg/L [range 0.1-13.5]) at a median of 6 days of therapy, with 26.4% subtherapeutic and 21.5% supratherapeutic; 46/88 (52.3%) were therapeutic at the second measurement (2.1mg/L [0.1-9.9]) at a median of 17 days of therapy; and 33/48 (68.8%) at the third (2.3mg/L [0.1-7.7]) at a median of 29 days. In multivariable analysis of factors associated with sub- or supratherapeutic levels (body mass index ≥30, concurrent omeprazole use, concurrent letermovir use, indication for VCZ, history/timeframe of HCT), the only significant association was lower odds of a supratherapeutic VCZ level among those undergoing HCT within the previous 30 days compared to those without a history of HCT. VCZ continues to remain an important option in the treatment and prevention of invasive fungal infections in an era when alternative oral mold-active triazoles are available. In spite of long-standing experience with VCZ prescribing, therapeutic level attainment remains a challenge.

Contemporary Perspective on the Treatment of Acinetobacter baumannii Infections: Insights from the Society of Infectious Diseases Pharmacists.

The purpose of this narrative review is to bring together the most recent epidemiologic, preclinical, and clinical findings to offer our perspective on best practices for managing patients with A. baumannii infections with an emphasis on carbapenem-resistant A. baumannii (CRAB). To date, the preferred treatment for CRAB infections has not been defined. Traditional agents with retained in vitro activity (aminoglycosides, polymyxins, and tetracyclines) are limited by suboptimal pharmacokinetic characteristics, emergence of resistance, and/or toxicity. Recently developed and US Food and Drug Administration (FDA)-approved ß-lactam/ß-lactamase inhibitor agents do not provide enhanced activity against CRAB. On balance, cefiderocol and eravacycline demonstrate potent in vitro activity and are well tolerated, but clinical data for patients with CRAB infections do not yet support widespread use. Given that CRAB has the capacity to infect vulnerable patients and preferred regimens have not been identified, we advocate for combination therapy. Our preferred regimen for critically ill patients infected, or considered to be at high risk for CRAB, includes meropenem, polymyxin B, and ampicillin/sulbactam. Importantly, site of infection, severity of illness, and local epidemiology are essential factors to be considered in selecting combination therapies. Molecular mechanisms of resistance may unveil preferred combinations at individual centers; however, such data are often unavailable to treating clinicians and have not been linked to improved clinical outcomes. Combination strategies may also pose an increased risk for antibiotic toxicity and Clostridioides difficile infection, and should therefore be balanced by understanding patient goals of care and underlying health conditions. Promising therapies that are in clinical development and/or under investigation include durlobactam-sulbactam, cefiderocol combination regimens, and bacteriophage therapy, which may over time eliminate the need for the continued use of polymyxins. Future goals for CRAB management include pathogen-focused treatment paradigms that are based on molecular mechanisms of resistance, local susceptibility rates, and the availability of well-tolerated, effective treatment options.

Effect of High-Dose Posaconazole on Serum Levels in Adult Patients with Hematologic Malignancy.

Posaconazole (POS) appears to have dose-proportional pharmacokinetics; however, there is a paucity of real-life data. We retrospectively evaluated 67 patients with hematologic cancer who had POS dose increases from 300 mg/day to either 400 mg/day (n = 52) or 300 mg twice daily (BID) (n = 15) and for whom POS serum levels were measured. Median POS levels were 840 ng/ml, 1,625 ng/ml, and 2,710 ng/ml for the dosages of 300 mg/day, 400 mg/day, and 300 mg BID, respectively. Significant interpatient variability in serum levels was noted.

Association of Physician Orders for Life-Sustaining Treatment With Inpatient Antimicrobial Use at End of Life in Patients With Cancer.

BACKGROUND: Antimicrobial utilization at end of life is common, but whether advance directives correlate with usage is unknown. We sought to determine whether Washington State Physician Orders for Life Sustaining Treatment (POLST) form completion or antimicrobial preferences documented therein correlate with subsequent inpatient antimicrobial prescribing at end of life. METHODS: This was a single-center, retrospective cohort study of adult patients at a cancer center who died between January 1, 2016, and June 30, 2019. We used negative binomial models adjusted for age, sex, and malignancy type to test the relationship between POLST form completion ≥30 days before death, antimicrobial preferences, and antimicrobial days of therapy (DOT) per 1000 inpatient-days in the last 30 days of life. RESULTS: Among 1295 eligible decedents with ≥1 inpatient-day during the last 30 days of life, 318 (24.6%) completed a POLST form. Of 318, 120 (37.7%) were completed ≥30 days before death, 35/120 (29.2%) specified limited antimicrobials, 55/120 (45.8%) specified full antimicrobial use, and 30/120 (25%) omitted antimicrobial preference. Eighty-three percent (1070/1295) received ≥1 inpatient antimicrobial. The median total and intravenous (IV) antimicrobial DOT/1000 inpatient-days were 1077 and 667. Patients specifying limited antimicrobials had significantly lower total antimicrobial DOT (adjusted incidence rate ratio [IRR], 0.68; 95% CI, 0.49-0.95; P = .02) and IV antimicrobial DOT (IRR, 0.57; 95% CI, 0.38-0.86; P = .008) compared with those without a POLST. CONCLUSIONS: Indicating a preference for limited antimicrobials on a POLST form ≥30 days before death may lead to less inpatient antimicrobial use in the last 30 days of life.

Are hematopoietic cell transplant recipients with Gram-negative bacteremia spending more time outpatient while on intravenous antibiotics? Addressing trends over 10 years at a single center.

INTRODUCTION: The increasing proportion of outpatient allogeneic hematopoietic cell transplants (HCTs) coupled with increased access of once-daily broad-spectrum antibiotics and evidence that outpatient antibiotic treatment may be safer and less costly than inpatient treatment, suggest that allogeneic HCT recipients with Gram-negative rod bacteremia (GNRBs) are increasingly being treated in ambulatory care settings. METHODS: Using data from the first GNRB event that occurred within the first 100 days posttransplantation among allogeneic HCT recipients transplanted at a single center between 2007 and 2016, we estimated the temporal trends in GNRB incidence and treatment management of GNRBs and identified if patient or infection characteristics impacted observed trends. RESULTS: A total of 11% (238/2165) of the observed allogeneic HCT recipients experienced ≥1 GNRB with available resistance data and contributed antibiotic treatment time. Patients, on average, received 55.1% of their antibiotic treatment in an outpatient setting and we observed a significant decline in the proportion of treatment time spent outpatient (crude: -3.3% [95% confidence interval: -5.0, -1.6%]). We observed similar declines in the proportion of treatment time spent outpatient among patients with similar GNRB and pretransplant complexity factors but not among patients with similar posttransplant complications (p value: .165). CONCLUSION: These results suggest that, despite increased availability of outpatient suitable treatment options, allogeneic HCT recipients with GNRBs received less treatment in outpatient settings. However, among patients with similar posttransplant complications, the lack of significant decline suggests that treatment location decisions remained consistent for patients with similar posttransplant complications. These findings suggest the need for additional interventions targeting outpatient antibiotic treatment among allogeneic HCT recipients with GNRBs.

Impact of a pharmacy-driven transitions-of-care program on postdischarge healthcare utilization at a national comprehensive cancer center.

PURPOSE: Results of a study comparing readmission rates and medication adherence measures before and after implementation of a pharmacy-led transitions-of-care (TOC) program are reported. METHODS: A quasi-experimental case-control study was conducted to assess the impact of a TOC program including medication history-taking and reconciliation services, inpatient and discharge education, and 72-hour and 30-day postdischarge phone follow-up. Hospital and emergency room (ER) readmission rates were compared in cohorts of oncology patients admitted to a large teaching hospital during specified periods before TOC program implementation (the standard-of-care [SOC] group) or after program implementation (the TOC group). The primary outcome was unplanned hospital or ER readmission within 30 days after initial discharge. The secondary endpoint was first-fill medication adherence. Benefits associated with specific TOC interventions were assessed in subgroup analyses. RESULTS: After propensity score matching, both study groups consisted of 323 patients. The SOC group had 76 patients (23.5%) and the TOC group had 74 patients (22.9%) who were readmitted to the hospital or ER within 30 days, with a significant reduction in hospital readmissions in 1 subgroup of TOC patients versus SOC controls (absolute difference, -7.6%; p = 0.0159). CONCLUSION: While there were no significant overall differences in readmission rates between the TOC and SOC groups, hospital readmissions were reduced in the subgroup of TOC patients who received both medication history-taking and reconciliation services and phone follow-up as TOC interventions.

Clinical Outcomes Associated With Linezolid Resistance in Leukemia Patients With Linezolid-Resistant Staphylococcus epidermidis Bacteremia.

BACKGROUND: Coagulase-negative staphylococci, including Staphylococcus epidermidis, are the most common cause of bloodstream infection in cancer patients. Linezolid resistance is increasingly identified in S. epidermidis, but whether such resistance alters the clinical course of S. epidermidis infections is unknown. The purpose of this study was to assess the clinical impact of linezolid resistance in leukemia patients with S. epidermidis bloodstream infection. METHODS: This was a retrospective, single-center cohort study of all adult leukemia patients with S. epidermidis bacteremia treated with empiric linezolid between 2012 and 2015. The primary end point was adverse clinical outcome on day 3, defined as a composite of persistent bacteremia, fever, intensive care unit admission, or death. Fourteen- and 30-day mortality were also assessed. RESULTS: Eighty-two unique leukemia patients with S. epidermidis were identified. Linezolid resistance was identified in 33/82 (40%). Patients with linezolid-resistant S. epidermidis were significantly more likely to have persistent bacteremia (41% vs 7%; adjusted relative risk [aRR], 5.15; 95% confidence interval [CI], 1.63-16.30; P = .005); however, adverse short-term clinical outcomes overall were not more common among patients with linezolid-resistant S. epidermidis (61% vs 33%; aRR, 1.46; 95% CI, 0.92-2.32; P = .108). No differences were observed in 14- or 30-day mortality. CONCLUSIONS: Leukemia patients with linezolid-resistant S. epidermidis bacteremia who were treated with linezolid were significantly more likely to have persistent bacteremia compared with those with linezolid-sensitive isolates. Interventions to limit the clinical impact of linezolid-resistant S. epidermidis are warranted.

Timing to antibiotic therapy in septic oncologic patients presenting without hypotension.

PURPOSE: Sepsis accounts for only 2% of the hospitalizations worldwide but more than 17% of total in-hospital mortality. Inappropriate antimicrobial selection and delays in appropriate therapy have been associated with reduced survival in severe sepsis and septic shock. No studies to date have exclusively targeted septic oncologic patients without hypotension. METHODS: This study was a retrospective chart review of 100 adult cancer patients presenting to the emergency department with sepsis without hypotension. We investigated the effect of time to appropriate antibiotics on in-hospital mortality and hospital length of stay. It was hypothesized that increased time to antibiotic administration would worsen patient outcomes including in-hospital mortality and length of stay. RESULTS: Each 1-h delay in administration of appropriate antibiotic therapy increased the odds of in-hospital mortality by 16% (adjusted OR 1.16. 95% CI 1.04-1.34, p = 0.04). Time to appropriate antibiotics had no effect on hospital length of stay. CONCLUSIONS: Time to appropriate antibiotics and in-hospital mortality were associated in this population of adult oncologic patients with sepsis without hypotension. Clinicians in the emergency department should strive to ensure the timely administration of a complete and appropriate empiric antibiotic regimen in septic patients with active cancer even in the absence of hypotension.

Real-Life Assessment of the Safety and Effectiveness of the New Tablet and Intravenous Formulations of Posaconazole in the Prophylaxis of Invasive Fungal Infections via Analysis of 343 Courses.

Posaconazole is the preferred mold-active azole for prophylaxis against invasive fungal infections (IFIs) in patients with hematological malignancy. Delayed-release tablet and intravenous formulations of posaconazole have recently become available, but clinical data are limited. We sought to examine the real-world pharmacokinetics and prophylactic effectiveness of the new formulations of posaconazole given as prophylaxis for patients with hematological malignancy. A retrospective cohort of all consecutive adult inpatients with hematological malignancy who received ≥3 days of tablet or intravenous posaconazole therapy for primary IFI prophylaxis at the M. D. Anderson Cancer Center between 1 December 2013 and 31 December 2015 was established. Clinical information was collected and correlated with low posaconazole serum levels (<700 ng/ml). Rates of IFIs and safety events were assessed. A total of 1,321 courses of posaconazole were administered at the M. D. Anderson Cancer Center during the study period, of which 343 courses were assessed for prophylactic safety and effectiveness. Seventy-nine patients (23%) had posaconazole serum level measurements available for interpretation. Acute myeloid leukemia was the primary malignancy (62%), with 20% of all patients having previously received a stem cell transplant. The median posaconazole level was 1,380 ng/ml (interquartile range, 864 to 1,860 ng/ml). Low posaconazole levels (<700 ng/ml) were observed for 14 patients (18%). Proven or probable breakthrough IFIs occurred in 8 patients (2%); posaconazole therapeutic drug monitoring (TDM) was performed for 6 of those patients, all with levels above 700 ng/ml. Overall, 19% of patients experienced grade 3 or 4 liver injury, manifesting primarily as hyperbilirubinemia and being correlated with serum levels of >1,830 ng/ml. Although hepatotoxicity in a small percentage of patients is of concern, posaconazole tablets appeared to be generally safe and effective. As all breakthrough IFIs for which TDM was performed occurred in patients with levels of >700 ng/ml, and a posaconazole level of >1,830 ng/ml was correlated with grade 3 or 4 liver toxicity, further studies are needed to assess the role of TDM.

Changes in In Vitro Susceptibility Patterns of Aspergillus to Triazoles and Correlation With Aspergillosis Outcome in a Tertiary Care Cancer Center, 1999-2015.

BACKGROUND: Azole-resistant aspergillosis in high-risk patients with hematological malignancy or hematopoietic stem cell transplantation (HSCT) is a cause of concern. METHODS: We examined changes over time in triazole minimum inhibitory concentrations (MICs) of 290 sequential Aspergillus isolates recovered from respiratory sources during 1999-2002 (before introduction of the Aspergillus-potent triazoles voriconazole and posaconazole) and 2003-2015 at MD Anderson Cancer Center. We also tested for polymorphisms in ergosterol biosynthetic genes (cyp51A, erg3C, erg1) in the 37 Aspergillus fumigatus isolates isolated from both periods that had non-wild-type (WT) MICs. For the 107 patients with hematologic cancer and/or HSCT with invasive pulmonary aspergillosis, we correlated in vitro susceptibility with 42-day mortality. RESULTS: Non-WT MICs were found in 37 (13%) isolates and was only low level (MIC <8 mg/L) in all isolates. Higher-triazole MICs were more frequent in the second period and were Aspergillus-species specific, and only encountered in A. fumigatus. No polymorphisms in cyp51A, erg3C, erg1 genes were identified. There was no correlation between in vitro MICs with 42-day mortality in patients with invasive pulmonary aspergillosis, irrespective of antifungal treatment. Asian race (odds ratio [OR], 20.9; 95% confidence interval [CI], 2.5-173.5; P = .005) and azole exposure in the prior 3 months (OR, 9.6; 95% CI, 1.9-48.5; P = .006) were associated with azole resistance. CONCLUSIONS: Non-WT azole MICs in Aspergillus are increasing and this is associated with prior azole exposure in patients with hematologic cancer or HSCT. However, no correlation of MIC with outcome of aspergillosis was found in our patient cohort.

Daptomycin non-susceptible Enterococcus faecium in leukemia patients: Role of prior daptomycin exposure.

OBJECTIVES: We sought to determine the association between previous daptomycin exposure and daptomycin non-susceptible Enterococcus faecium (DNSEf) bloodstream infections (BSI) in adult leukemia patients. METHODS: We retrospectively identified adult (≥18 years old) leukemia patients with Enterococcus spp. bacteremia at The University of Texas MD Anderson Cancer Center (MDACC) from 6/1/2013 to 7/22/2015. Antimicrobial susceptibility and previous antibiotic exposure within the 90 days prior to bacteremia were collected. Classification and Regression Tree (CART) analysis was used to identify the most significant breakpoint between daptomycin exposure and DNSEf. RESULTS: Any amount of daptomycin received within the 90 days preceding BSI was significantly associated with isolation of DNSEf compared to daptomycin susceptible E. faecium (DSEf) (88% vs. 44%, respectively, p < 0.01). CART analysis identified receiving ≥13 days of daptomycin in the preceding 90 days as most significantly correlated with DNSEf (60% vs. 11%, relative risk [RR] 5.31, 95% Confidence interval [CI] 2.36-11.96, p < 0.01). CONCLUSIONS: Prior daptomycin exposure for ≥13 days within 90 days preceding BSI was significantly associated with isolation of DNSEf BSI in adult leukemia patients at our institution. Antimicrobial stewardship initiatives aimed at minimizing daptomycin exposure in high-risk patients may be of significant benefit in limiting the emergence of DNSEf.