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Background Piperacillin-tazobactam-non-susceptible/ceftriaxone-susceptible (TZP-NS/CRO-S) Escherichia coli (Ec) and Klebsiella pneumoniae (Kp) phenotypes are hypothesized to be due to hyperproduction of TEM-1/2 and SHV-1 penicillinases. Limited available literature evaluating treatment outcomes in patients with TZP-NS/CRO-S infections may lead to unnecessary carbapenem use. Methods This was a retrospective study of non-critically ill adults hospitalized between 2013-2021, and treated for at least 48 hours for TZP-NS/CRO-S Ec or Kp infections. Patients with concomitant multi-drug resistant gram-negative infections were excluded. The primary composite endpoint included the need for escalation to intensive care unit (ICU), infection- or treatment-related readmission, mortality, and infection recurrence. Outcomes were compared between groups who received carbapenem (CG) vs carbapenem-sparing agents (CSG) as targeted therapy. Results Out of 1062 patients screened, 200 were included, with 51 in the CG and 149 in the CSG. Baseline characteristics, including Charlson Comorbidity Index (6 [IQR 3-10] vs 6 [4-9], p=0.64), were similar between groups, except for more immunocompromised patients in the CG (29% vs 11%, p=0.001). The most common infection sources were urinary (31% vs 57%, p=0.002), bloodstream (BSI) (18% vs 17%, p=0.887) and intra-abdominal (IAI) (20% vs 8%, p=0.023). Eighty-eight percent of the CG received meropenem, while the most common targeted therapy in the CSG was ceftriaxone (58%) followed by cefepime (24%). The primary composite endpoint was numerically higher in the CG (27% vs 17%, p=0.123), with no differences based on infection type (urine 25% vs 18%, p=0.495; BSI 33% vs 16%, p=0.348; IAI 40% vs 33%, p=1). More patients in the CSG were switched to oral therapy (15 [29%] vs 100 [67%], p< 0.001), with numerically 2 days shorter time to oral switch (6 [3-9] vs 4 [3-7] days, p=0.196). Out of those switched to oral therapy, most had a urinary source (8/15 [53%] vs 59/100 [59%]). Conclusion Our study did not find better clinical outcomes with carbapenem therapy for TZP-NS/CRO-S infections, thus CS agents may be considered to spare carbapenems in non-critically ill patients. Further studies are warranted to compare these outcomes in the critically ill. Disclosures All Authors: No reported disclosures.

Background Candidemia is a common hospital acquired infection that is associated with significant morbidity and mortality. The optimal strategy for diagnosis remains unknown. Methods We evaluated 2 distinct diagnostic strategies in hospitalized patients with suspicion of Candida bloodstream infection, namely strategy #1 that included simultaneous blood cultures and T2Candida and strategy #2 that included blood cultures, T2Candida testing and Beta-D-glucan (BDG). We examined the consistency with which each diagnostic algorithm led to changes in antifungal prescribing, the overall rate of antifungal utilization and patients’ clinical outcomes. Flow Chart. Figure 1. Results Among 96 patients tested with strategy #1, 3 had a positive result. Of those 100% completed a 14-day antifungal course for candidemia or were on antifungals until hospital discharge. Of the 29 out 120 patients that tested positive with strategy #2, 55.2% received a complete 14-day course or were on antifungals until hospital discharge. The percentage of completed treatment increased to 75.0% and 80.0% when the threshold for BDG positivity was increased at 200 pg/ml and 500 pg/ml respectively. We observed a significant difference in the overall antifungal utilization with 268.5 days of antifungals per 1,000 patient days for strategy #1, as opposed to 371.9 days of antifungals for strategy #2, a 38.5% increase. Negative tests at both diagnostic strategies led to a similar rate of antifungal discontinuation 3 days after testing (36.8% and 37.0% for strategy #1 and #2 respectively). We did not find significant benefits in death and/or subsequent diagnosis of candidemia between the 2 diagnostic strategies. Sensitivity analyses performed based on indication for testing and severity of illness did not significantly alter results. Table 1.Characteristics of patients tested for suspicion of candidemia with the 2 diagnostic strategies. Figure 2. Duration of antifungal therapy among patients with positive BDG at different thresholds A. BDG Figure 3. Percentage of patients who were taken off antifungals within 3 days of testing for different BDG thresholds, BDG Conclusion In summary, the addition of BDG in diagnostic algorithms for candidemia was interpreted variably by clinicians, was associated with a significant increase in antifungal utilization, and it did not appear to lead to measured clinical benefits for patients. Diagnostic strategies of common and serious infections that incorporate non-culture diagnostics need to be evaluated for added benefit. Table 2.Antifungal utilization among patients tested for suspicion of candidemia with the 2 diagnostic strategies. Table 3. Outcomes among patients tested for suspicion of candidemia with the two different diagnostic strategies. Disclosures All Authors: No reported disclosures.

Purpose: Outpatient antimicrobial stewardship programs (ASPs) are becoming increasingly prevalent in healthcare. Many programs have demonstrated the effectiveness of pharmacist-driven outpatient consultations or follow-up programs to ensure appropriate antimicrobial prescribing. However, there is a paucity of literature describing multidisciplinary approaches in large healthcare systems for patients discharged from the emergency department (ED). The objective of this study was to describe the feasibility and impact of a combined effort between ASP pharmacotherapy specialists and nurse practitioners (NPs) in managing an ED follow-up center. Methods: A retrospective analysis was conducted for patients discharged from the ED between January 2018 and June 2019. Patients were identified for inclusion based on documentation by ASP pharmacotherapy specialists in the electronic health record for patient-specific inquiries from ED follow-up center NPs. The primary outcome of this study was to describe the number and types of interventions made by ASP pharmacotherapy specialists. Results: A total of 1088 patients were included in the study, for 1114 documented ASP calls. The urinary tract was the most common source of positive culture (79%), and third-generation cephalosporins were the most frequent antibiotic associated with calls (20%). Out of total calls, 60% lead to ASP interventions. Among total calls, the most frequent interventions were to correct drug-bug mismatches (20%), initiate new therapy (10%), and discontinue therapy (7%). Conclusion: This report describes a novel initiative that combines the efforts of ED NPs and ASP pharmacotherapy specialists in managing an ED follow-up center at a large healthcare system.

Background Patients with coronavirus disease 2019 (COVID-19) admitted to the intensive care unit (ICU) have poor outcomes and frequently develop comorbid conditions, including cytomegalovirus (CMV) reactivation. The implications of CMV reactivation in this setting are unknown. We aimed to investigate if treatment of CMV viremia improved in-hospital mortality in ICU patients with COVID-19. Methods In this single-center retrospective study, we analyzed clinical outcomes in patients diagnosed with COVID-19 pneumonia and CMV viremia admitted to an ICU from March 1, 2020, to April 30, 2021, who either received treatment (ganciclovir and/or valganciclovir) or received no treatment. The primary outcome was all-cause in-hospital mortality. Secondary outcomes were total hospital length of stay (LOS), ICU LOS, requirement for extracorporeal membrane oxygenation (ECMO) support, duration of mechanical ventilation (MV), and predictors of in-hospital mortality. Results A total of 80 patients were included, 43 patients in the treatment group and 37 in the control group. Baseline characteristics were similar in both groups. CMV-treated patients were more likely to test positive for CMV earlier in their course, more likely to be on ECMO, and received higher total steroid doses on average. In-hospital mortality was similar between the 2 groups (37.2% vs 43.2.0%; P = .749). There was no significant difference in hospital LOS, though CMV-treated patients had a longer ICU LOS. Conclusions Treatment of CMV viremia did not decrease in-hospital mortality in ICU patients with COVID-19, but the sample size was limited. CMV viremia was significantly associated with total steroid dose received and longer ICU stay.

Background As New York became the epicenter of the COVID-19 pandemic early on, clinicians were challenged to provide optimal medical and pharmaceutical care, despite the paucity of supporting literature and guidance. We sought to describe prescribing patterns and outcomes of physician response to the urgent need to treat COVID-19 patients before initiation of randomized clinical trials. Methods This was a retrospective cohort study of adult patients with COVID-19 initially admitted to acute care services during March 2020. Critically ill patients requiring intensive care unit level of care on admission were excluded. Results A total of 639 consecutive patients (supportive care, n = 247; treatment n = 392) were included in the analysis. Overall, the 28-day mortality rate was 12.2%. The mortality was 8.7% higher in the treatment group (15.6% vs 6.9% in the supportive care group, P < 0.001). Treatment was not protective against progression to severe disease (18.4% vs 3.6% with supportive care, P < 0.0001). Time to defervescence, duration of oxygen support, and hospital and intensive care unit (ICU) length of stay were also higher in the treatment group. In multivariate analysis, 60 years or older, presence of severe disease, and need for ICU admission were identified as independent predictors of 28-day mortality. There were 41 (10.5%) adverse event in the treatment group, with the majority being QT prolongation and gastrointestinal effects. Conclusions In this cohort of hospitalized patients admitted to acute care services, treatment with hydroxychloroquine, lopinavir/ritonavir or both could not be shown to improve mortality, progression to severe disease, or clinical response.

Objective:The data regarding the effectiveness of chemical prophylaxis against recurrentC. difficileinfection (CDI) remain conflicting.Design:Retrospective cohort study on the effectiveness of oral vancomycin for prevention of recurrent CDI.Setting:Two academic centers in New York.Methods:Two participating hospitals implemented an automated alert recommending oral vancomycin 125 mg twice daily in patients with CDI history scheduled to receive systemic antimicrobials. Measured outcomes included breakthrough and recurrent CDI rates, defined as CDI during and 1 month after initiation of prophylaxis, respectively. A self-controlled, before-and-after study design was employed to examine the effect of vancomycin prophylaxis on the prevalence of vancomycin-resistantEnterococcusspp (VRE) colonization and infection.Results:We included 264 patients in the analysis. Breakthrough CDI was identified in 17 patients (6.4%; 95% confidence interval [CI], 3.8%–10.1%) and recurrent in 22 patients (8.3%; 95% CI, 5.3%–12.3%). Among the 102 patients with a history of CDI within the 3 months preceding prophylaxis, 4 patients (3.9%; 95% CIs, 1.1%–9.7%) had breakthrough CDI and 9 had recurrent disease (8.8%; 95% CIs, 4.1%–16.1%). In the 3-month period following vancomycin prophylaxis, we detected a statistically significant increase in both the absolute number of VRE (χ2, 0.003) and the ratio of VRE to VSE isolates (χ2, 0.003) compared to the combined period of 1.5 months preceding and the 3–4.5 months following prophylaxis. This effect persisted 6 months following prophylaxis.Conclusions:Prophylactic vancomycin is an effective strategy to prevent CDI recurrence, but it increases the risk of VRE colonization. Thus, a careful selection of patients with high benefit-to-risk ratio is needed for the implementation of this preventive policy.

Purpose A critical shortage of small-volume parenteral solutions in late 2017 led hospitals to develop strategies to ensure availability for critical patients, including administration of antibiotics as intravenous push (IVP). Minimal literature has been published to date that assesses the safety of administration of beta-lactams via this route. Therefore, the purpose of this study was to evaluate the safety of IVP administration of select beta-lactam antibiotics. Methods We performed a retrospective review of IVP administrations of aztreonam, ceftriaxone, cefepime, and meropenem at two campuses of the New York University Langone Health system after October 2017. Patients receiving surgical prophylaxis or more than one IVP antibiotic simultaneously were excluded. The primary endpoint was adverse events (ADE) following IVP administration of antibiotics. Results We evaluated 1000 patients who received IVP aztreonam (n = 43), ceftriaxone (n = 544), cefepime (n = 368) or meropenem (n = 45). There were 10 (1%) ADE observed, 5 of which were allergic reactions. Four ADE were neurotoxicity related to IVP cefepime. Based on the Naranjo score, 1 adverse event was “probably” and 3 were “possibly” related to cefepime IVP administration. Lastly, only 1 report of phlebitis was observed with the use of IVP ceftriaxone. Conclusions The use of IVP as an alternative to intravenous piggyback (IVPB) during times of drug shortage for select beta-lactam antibiotics appears to be safe, and ADE are similar to those previously described for IVPB administration. Future studies evaluating clinical outcomes between IVP and IVPB administration may be of benefit.

Background The epidemiology of nosocomial bloodstream infections (NBSIs) in patients with coronavirus disease 2019 (COVID-19) is poorly understood, due in part to substantial disease heterogeneity resulting from multiple potential pathogens. Methods We identified risk factors for NBSIs and examined the association between NBSIs and mortality in a retrospective cohort of patients hospitalized with COVID-19 in 2 New York City hospitals during the height of the pandemic. We adjusted for the potential effects of factors likely to confound that association, including age, race, illness severity upon admission, and underlying health status. Results Between January 1 and October 1, 2020, 1403 patients had a positive blood culture, and 79 and 101 met the stringent criteria for NBSI among non-COVID-19 and COVID-19 patients, respectively. NBSIs occurred almost exclusively among patients who were severely ill with COVID-19 at hospital admission. NBSIs were associated with elevated mortality, even after adjusting for baseline differences in COVID-19 illness (55% cases vs 45% controls; P = .13). Mortality was concentrated in patients with early-onset pneumonia caused by S. aureus and gram-negative bacteria. Less virulent Candida (49%) and Enterococcus (12%) species were the predominant cause of NBSI in the latter stages of hospitalization, after antibiotic treatment and COVID-19 treatments that attenuate immune response. Most Enterococcus and Candida infections did not have an identifiable source and were not associated with common risk factors for infection by these organisms. Conclusions Pathogen species and mortality exhibited temporal differences. Early recognition of risk factors among COVID-19 patients could potentially decrease NBSI-associated mortality through early COVID-19 and antimicrobial treatment.

Background Limited data support use of pneumococcal urinary antigen testing (PUAT) for patients with community-acquired pneumonia (CAP) as an antimicrobial stewardship tool. At our institution, CAP guidelines and admission order set were standardized to include universal PUAT. Methods This was a retrospective study of adults hospitalized in 2019 who had PUAT performed. We compared incidence and timing of de-escalation in PUAT- positive vs -negative groups and described patients’ outcomes. Results We evaluated 910 patients, 121 (13.3%) of whom were PUAT positive. No difference in baseline characteristics, including severity of illness, was observed between groups. Initial de-escalation occurred in 82.9% and 81.2% of PUAT-positive and -negative patients, respectively (P = .749). Median time to de-escalation was shorter in the PUAT-positive group (1 [interquartile range {IQR}, 0–2] day vs 1 [IQR, 1–2] day, P = .01). Within 24 hours of PUAT, more patients in the PUAT-positive group had atypical coverage discontinued (61.3% vs 47.2%, P = .026) without difference in methicillin-resistant Staphylococcus aureus (MRSA) agent discontinuation (or antipseudomonal de-escalation). Among the PUAT-positive group, unadjusted analysis demonstrated shorter median length of stay in patients who were de-escalated compared to those who were not (6 [IQR, 4–10] vs 8 [IQR, 7–12] days, P = .0005), without difference in the incidence of Clostridioides difficile, in-hospital mortality, or 30-day infection-related readmission. Conclusions We observed earlier de-escalation in the PUAT-positive group. This seems to be due to discontinuation of atypical rather than anti-MRSA or antipseudomonal coverage. Further antimicrobial stewardship interventions are warranted.

OBJECTIVES Secondary oral vancomycin prophylaxis (OVP) has been used in adults with a history of Clostridioides difficile infection (CDI) while receiving systemic antibiotics to prevent CDI recurrence. However, this practice has not been studied in pediatric patients. The objective of this study was to assess the utility of secondary OVP in pediatric patients with previous CDI who received subsequent antibiotic exposure. METHODS A multicampus, retrospective cohort evaluation was conducted among patients aged ≤18 years with any history of clinical CDI and receiving systemic antibiotics in a subsequent encounter from 2013–2019. Patients who received concomitant OVP with antibiotics were compared with unexposed patients. The primary outcome was CDI recurrence within 8 weeks after antibiotic exposure. Infection with vancomycin-resistant enterococci and risk factors for CDI recurrence were assessed. RESULTS A total of 148 patients were screened, of which 30 and 44 patients received OVP and no OVP, respectively. Patients who received OVP had greater antibiotic use and hospital lengths of stay. The incidence of CDI recurrence within 8 weeks of antibiotic exposure was significantly lower in patients who received OVP (3% vs 25%; P = .02) despite this group having notably more risk factors for recurrence. There were no vancomycin-resistant enterococci infections in any patients within either group. After adjustment in a multivariable analysis, secondary OVP was associated with less risk of recurrence (odds ratio, 0.10; 95% confidence interval, 0.01–0.86; P = .04). CONCLUSIONS Secondary OVP while receiving systemic antibiotics reduces the risk of recurrent CDI in pediatric patients with a history of CDI.

Background: Midline catheters (MCs) have arisen as alternatives to peripherally inserted central catheters (PICCs) for both general intravenous therapy and extended outpatient parenteral therapy. However, there is a lack of data concerning the safety of medication therapy through midline for extended durations. Objective: The purpose of this study is to evaluate the safety of MCs for extended intravenous use. Methods: This was a retrospective cohort study evaluating patients who received intravenous therapy through an MC at a tertiary care academic medical center. The primary end point was the incidence of composite catheter-related adverse events that included local events, catheter dislodgment, infiltration, catheter occlusion, catheter-related venous thromboembolism, extravasation, and line-associated infection. Results: A total of 82 MC placements and 50 PICC placements were included; 50 MCs were for outpatient parenteral antimicrobial therapy, and 32 were for inpatient intravenous use. There were 21 complications per 1000 catheter-days in the outpatient group and 7 complications per 1000 catheter-days in the PICC group ( P = 0.91). The median time to complication in both groups was 8 days. The antimicrobial classes commonly associated with complications were cephalosporins, carbapenems, and penicillins. Conclusion and Relevance: Our results suggest that intravenous therapy with MCs is generally safe for prolonged courses that do not exceed 14 days as compared with PICC lines, which can be placed for months. There is still limited evidence for the use of MCs between 14 and 28 days of therapy. This study can help guide our selection of intravenous catheters for the purpose of outpatient antimicrobial therapy.

Secondary oral vancomycin prophylaxis (OVP) has been used in adults with a history ofA multicampus, retrospective cohort evaluation was conducted among patients aged ≤18 years with any history of clinical CDI and receiving systemic antibiotics in a subsequent encounter from 2013-2019. Patients who received concomitant OVP with antibiotics were compared with unexposed patients. The primary outcome was CDI recurrence within 8 weeks after antibiotic exposure. Infection with vancomycin-resistant enterococci and risk factors for CDI recurrence were assessed.A total of 148 patients were screened, of which 30 and 44 patients received OVP and no OVP, respectively. Patients who received OVP had greater antibiotic use and hospital lengths of stay. The incidence of CDI recurrence within 8 weeks of antibiotic exposure was significantly lower in patients who received OVP (3% vs 25%;Secondary OVP while receiving systemic antibiotics reduces the risk of recurrent CDI in pediatric patients with a history of CDI.

Background Ceftriaxone (CTX) and penicillin G (PCN G) are considered reasonable treatment options for viridans group streptococci (VGS) bloodstream infections, but comparisons between these agents are limited. We evaluated clinical outcomes among patients treated with these agents for complicated VGS bacteremia. Methods This was a single-center retrospective study of adult patients with ≥1 positive VGS blood culture who were treated with either CTX or PCN G/ampicillin (both included in the PCN arm) between January 2013 and June 2019. The primary outcome was a composite of safety end points, including hospital readmission due to VGS bacteremia or adverse events (AEs) from therapy, Clostridioides difficile infections, treatment modification or discontinuation due to AEs from therapy, and development of extended-spectrum beta-lactamase resistance. Secondary outcomes included individual safety end points, VGS bacteremia recurrence, hospital readmission, and all-cause mortality. Results Of 328 patients screened, 94 met eligibility criteria (CTX n = 64, PCN n = 30). Streptococcus mitis was the most common isolate, and infective endocarditis was the predominant source of infection. CTX was not significantly associated with increased risk of the primary composite safety outcome (CTX 14% vs PCN 27%; P = .139). The driver of the composite outcome was hospital readmission due to VGS bacteremia or therapy complications. No secondary end points differed significantly between groups. On multivariate analysis, source removal was a protective factor of the primary composite safety outcome. Conclusions Despite potential safety concerns with the prolonged use of CTX in complicated VGS bacteremia, this study did not demonstrate higher rates of treatment failure, adverse events, or resistance.

What is known and objective Nationwide shortages of small-volume parenteral solutions (SVPS) compelled hospitals to develop strategies including the use of intravenous push (IVP) administration of antibiotics to reserve SVPS for absolute necessities. It is unknown if administration of beta-lactam antibiotics (BL) via IVP results in worse clinical outcomes compared to intravenous piggyback (IVPB) due to the potential inability to achieve pharmacodynamic targets. Methods Our health-system implemented a mandatory IVP action plan for BL from October 2017 to September 2018. This was a retrospective study of adult patients with GNB who received empiric therapy with IVPB (30 minutes) or IVP (5 minutes) cefepime (FEP) or meropenem (MEM) for at least 2 days. Endpoints included clinical response, microbiological clearance and mortality. All data are presented as n (%) or median (interquartile range). Results The final cohort included 213 patients (IVPB n = 105, IVP n = 108). The primary source of bacteremia was urinary, with Escherichia coli being the primary pathogen. Escalation of therapy was similar between groups (15 [14%] vs 11 [10%], P = .36) at a median of 3 days (P = .68). No significant differences were observed in any secondary endpoints including microbiological clearance, bacteremia recurrence, time to defervescence, WBC normalization, vasopressor duration or in-hospital mortality. What is new and conclusion Our findings suggest no differences in clinical response with the use of IVP compared to IVPB FEP and MEM for treatment of GNB. This form of administration may be considered as a fluid conservation strategy in times of shortage.

Background Effective therapies to combat coronavirus 2019 (COVID-19) are urgently needed. Hydroxychloroquine (HCQ) has in vitro antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but the clinical benefit of HCQ in treating COVID-19 is unclear. Randomized controlled trials are needed to determine the safety and efficacy of HCQ for the treatment of hospitalized patients with COVID-19. Methods We conducted a multicenter, double-blind randomized clinical trial of HCQ among patients hospitalized with laboratory-confirmed COVID-19. Subjects were randomized in a 1:1 ratio to HCQ or placebo for 5 days and followed for 30 days. The primary efficacy outcome was a severe disease progression composite end point (death, intensive care unit admission, mechanical ventilation, extracorporeal membrane oxygenation, and/or vasopressor use) at day 14. Results A total of 128 patients were included in the intention-to-treat analysis. Baseline demographic, clinical, and laboratory characteristics were similar between the HCQ (n = 67) and placebo (n = 61) arms. At day 14, 11 (16.4%) subjects assigned to HCQ and 6 (9.8%) subjects assigned to placebo met the severe disease progression end point, but this did not achieve statistical significance (P = .350). There were no significant differences in COVID-19 clinical scores, number of oxygen-free days, SARS-CoV-2 clearance, or adverse events between HCQ and placebo. HCQ was associated with a slight increase in mean corrected QT interval, an increased D-dimer, and a trend toward an increased length of stay. Conclusions In hospitalized patients with COVID-19, our data suggest that HCQ does not prevent severe outcomes or improve clinical scores. However, our conclusions are limited by a relatively small sample size, and larger randomized controlled trials or pooled analyses are needed.

Extended infusion (EI) administration of β-lactams can improve target attainment in critically ill patients with altered pharmacokinetics/pharmacodynamics. To optimize meropenem dosing in patients with severe sepsis/septic shock, our Antimicrobial Stewardship Program implemented a EI meropenem (EIM) protocol in an 18-bed Medical Intensive Care Unit in March 2014. In this retrospective study, we compared intensive care unit (ICU) mortality and clinical response in patients who received meropenem for ≥72 hours administered per EIM protocol of 1 g over 3 hours every 8 hours versus intermittent infusion (IIM) protocol of 500 mg over 30 minutes every 6 hours. Age, weight, comorbidities, severity of illness, and vasopressor use were comparable between groups (EIM protocol n = 52, IIM protocol n = 96). The IIM protocol group had higher rates of renal dose adjustment at meropenem initiation. Among 56 identified gram-negative (GN) pathogens, 94% had meropenem minimal inhibitory concentration ≤0.25 mg/L. The ICU mortality was lower (19 vs 37%; P = .032) and clinical response was higher (83% vs 46%; P < .01) in the EIM protocol versus IIM protocol group. Total vasopressor days were shorter (2 vs 3 days; P = .038), and white blood cell normalization rate was higher (87% vs 51%; P < .01) in the EIM protocol versus IIM protocol group. There was no difference in days of mechanical ventilation, duration of therapy, and ICU stay. The IIM protocol was also identified as an independent risk factor associated with ICU mortality (hazard ratio: 3.653, 95% confidence interval: 1.689-7.981; P = .001) after adjusting for Sequential Organ Failure Assessment score. In this cohort of patients with severe sepsis/septic shock and highly susceptible GN pathogens, there was improved mortality and clinical response in the EIM protocol group.

Background Limited data support the use of pneumococcal urinary antigen testing (PUAT) for patients admitted with community-acquired pneumonia (CAP) as a stewardship tool to curtail the use of broad-spectrum antimicrobials. At NYULH, CAP guidelines and admission order set were developed to standardize diagnostic testing, including PUAT. In this study we describe patients with positive versus negative PUAT and evaluate de-escalation and patients’ outcomes. Methods This was a retrospective study of adults admitted with diagnosis of CAP between January-December 2019 who had a PUAT performed. The primary outcome was incidence and timing of de-escalation of antimicrobials following PUAT result. Among patients with a positive PUAT we compared hospital length of stay (LOS), incidence of Clostridioides difficile infection (CDI), infection-related readmission within 30 days, and in-hospital mortality among those who were de-escalated versus those who were not de-escalated/required escalation. Results We evaluated 910 patients, of which 121 (13.3%) were PUAT positive. No difference in baseline characteristics, including severity of illness as represented by the Pneumonia Severity Index (97 [IQR 76-117] vs 89 [IQR 67-115], p=0.083) and Charlson Comorbidity Index, were observed between PUAT positive and negative groups. Time to PUAT testing occurred shortly after presentation to the hospital in both cohorts (16h [IQR 16-27] vs 13h [IQR 8-22], p=0.140). Initial de-escalation occurred in 97/117 (82.9%) and 629/775 (81.2%) of PUAT positive and negative patients, respectively (p = 0.749). Median time to de-escalation was shorter in the PUAT positive cohort (1 [IQR 0-2] vs 1 [IQR 1-2] day, p = 0.01). Among the PUAT positive group, hospital LOS stay was shorter in patients who were de-escalated compared to those who were not de-escalated/required escalation (6 days [IQR 4-10] vs 8 days [IQR 7-12], p=0.0005) with no difference in the incidence of CDI (2 [2.1%] vs 1 [3.7%], p=0.535), in-hospital mortality (4 [4.3%] vs 3 [11.1%], p=0.185), or 30-day infection-related readmission (2 [2.1%] vs 1 [3.7%], p=0.535). Conclusion PUAT positivity resulted in quicker time to targeted therapy for CAP. Among patients with a positive PUAT, initial de-escalation of antimicrobials did not lead to worse patient outcomes. Disclosures All Authors: No reported disclosures

Purpose The integration of pharmacy residents into an antimicrobial stewardship program (ASP) is described, and data on the residents’ ASP interventions and outcomes are reported. Summary ASP coverage of nighttime, holiday, and weekend shifts is often provided by infectious diseases (ID) medical fellows and staff pharmacists, potentially leading to inconsistent stewardship practices. As part of an initiative by a large urban hospital to provide around-the-clock, comprehensive ASP services 7 days a week, postgraduate year 2 (PGY2) pharmacy residents in ID or critical care were assigned to provide ASP coverage on weekends. Over a 12-month period, residents providing ASP weekend coverage documented a total of 1,443 interventions, of which 1,000 (69%) were pursuant to 72-hour prospective audit and feedback review and 443 (31%) occurred during ASP phone coverage. A comparison of overall antimicrobial utilization (mean ± S.D. days of therapy [DOT] per 1,000 patient-days [PD]) before and after implementation of resident ASP coverage on weekends showed a decrease in aggregate antimicrobial use from 799.3 ± 46.8 to 740.7 ± 17.3 DOT/1,000 PD (a difference of 58.6 DOT/1,000 PD, p = 0.08), with a corresponding decline in the incidence of hospital-onset Clostridium difficile infection (from 1.18 cases to 0.9 case per 1,000 PD). Conclusion By expanding the hospital’s ASP services by assigning PGY2 pharmacy residents to weekend coverage, the institution was able to provide high-level clinical care 7 days per week, which benefited both patients and PGY2 pharmacy residents while meeting national ASP regulatory requirements.

tudy Objective Despite recent reports of relatively high rates (16–37%) of acute kidney injury (AKI) in patients receiving the combination of intravenous piperacillin-tazobactam (PTZ) and vancomycin, data are limited evaluating the impact of PTZ infusion strategy on the occurrence of nephrotoxicity. The objective of this study was to compare the rates of nephrotoxicity in patients receiving vancomycin in combination with PTZ administered as an extended infusion (EI) versus a standard infusion (SI). Design Single-center, retrospective, matched cohort study. Setting Large, academic, tertiary care hospital. Patients Two hundred eighty adults with a creatinine clearance (CrCl) of 40 mL/minute or higher who received at least 96 hours of vancomycin plus PTZ EI (140 patients) or vancomycin plus PTZ SI (140 patients) between January 1, 2009, and December 31, 2011, and between January 1, 2013, and December 31, 2014 (year 2012 was skipped due the closure of inpatient units following Superstorm Sandy); 48 patients in each group were admitted to the intensive care unit. Measurements and Main Results Median age of all patients was 67 (interquartile range [IQR] 54–77) years, and CrCl was 75 (IQR 55–107) mL/minute. Nephrotoxicity was assessed by the risk, injury, failure, loss, and end-stage kidney disease (RIFLE) and Acute Kidney Injury Network (AKIN) criteria. Rates of AKI, according to these criteria, were similar between groups: 17.9% vs. 17.1% (p=1) and 32.9% vs. 29.3% (p=0.596) for the PTZ EI and PTZ SI groups, respectively. When controlling for residual differences between groups in a conditional logistic regression analysis, no association was observed between receipt of PTZ EI and RIFLE-defined AKI (odds ratio 0.522, 95% confidence interval 0.043–6.295, p=0.609). Time to onset of nephrotoxicity was 4 (IQR 3-6) days, with no significant difference noted between groups (p=0.887). Conclusion Our findings suggest a similar rate of nephrotoxicity between patients who received vancomycin in combination with PTZ EI versus PTZ SI. These results need to be further validated in a prospective, randomized, controlled study. This article is protected by copyright. All rights reserved.

Background: Although dalbavancin’s (DBV’s) long half-life and one-time dosing strategy confer ideal administration in the ambulatory setting, the optimal role of DBV in the management of acute bacterial skin and skin structure infections (ABSSSIs) remains to be elucidated. Objectives: The primary objective of this study was to compare treatment outcomes of ABSSSI between patients who received DBV in the emergency department (ED) as part of standard care versus patients who received DBV as part of a telehealth program. Methods: This was a retrospective cohort study evaluating patients who received DBV at 3 urban EDs. The primary end point was the incidence of ABSSSI recurrence. Secondary outcomes included need for hospital admission and ED length of stay (LOS; in hours). Results: A total of 65 ABSSSI treatment courses were included; 42 were included in the telehealth criteria (TC) cohort and 23 in the initial criteria (IC) cohort. There were 14% (6/42) infection recurrences in the TC cohort and 22% (5/23) in the IC cohort, with median time to recurrence being 4 and 14 days, respectively. Median ED LOS was significantly shorter in the TC (5 vs 25 hours, P < 0.05). Numerically fewer individuals in the TC cohort required inpatient admission (0 vs n = 2, 9%). Conclusion and Relevance: Our results suggest that patients may be safely administered DBV in an ED setting, with telehealth follow-up. Providing structured patient selection criteria is an effective method of assisting ED providers in selecting appropriate DBV candidates to limit potential recurrences and readmissions.

Invasive fungal infections (IFIs) continue to pose a serious challenge in patients undergoing transplantation. An essential need for treatment with immunosuppressive drugs necessary for sustenance of solid organ allograft; preparatory conditioning regimens use to facilitate hematopoietic stem cell engraftment; drugs given to mitigate hosts’ adaptive cellular immune response for prevention and treatment of graft-versus-host disease (GVHD), and visceral allgraft rejection promote the risk for opportunistic fungal disease. Despite the availability of new-generation diagostic assays, and availability of new antifungal drugs, IFIs continue to pose a serious challenge in the care for patients undergoing transplantation. For prevention and treatment of invasive fungal disease, systemic antifungal drugs are given episodically during the high-risk periods or for extended duration to maintain primary, or secondary suppression after successful resolution of an IFI episode. Selection of appropriate antifungal agent relies upon a number of factors that include patients' susceptibility for infection, spectrum of antimicrobial activity, drug toxicity profile, potential for drug-drug interaction, and clinical efficacy of various classes of antifungal compounds. In authors’ opinion, the role of antifungal drugs in eliciting and promoting drug resistance among clinically relevant fungi should also be an important part of the drug selection process. In this chapter, a review of antifungal drugs with a focus on drug resistance is provided.

Background Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection that can lead to significant morbidity and mortality in immunocompromised pediatric hematology/oncology patients. Trimethoprim/sulfamethoxazole is the gold standard for prophylaxis. Intravenous (IV) pentamidine is the preferred second-line agent for PCP prophylaxis at our institution and is used first-line under certain circumstances. The purpose of this study is to evaluate the effectiveness and safety of IV pentamidine for PCP prophylaxis in pediatric hematology/oncology patients. Materials and methods A retrospective analysis of pediatric hematology/oncology patients (N=121) who received ≥1 dose of IV pentamidine between January 2009 and July 2014 was conducted. Electronic health records were reviewed to determine baseline characteristics, rate of breakthrough PCP infection, characteristics of IV pentamidine use, and adverse events. The follow-up period was 6 months after the last reported IV pentamidine dose or the last recorded clinic visit/hospital admission. Results No patients developed PCP during the entirety of their IV pentamidine course or during the follow-up period. Nineteen patients (16%) experienced adverse events and 5 of the 19 patients required discontinuation of IV pentamidine. Conclusions IV pentamidine is a safe, tolerable, and effective agent for PCP prophylaxis in pediatric hematology/oncology patients and may be considered a reasonable therapeutic alternative when trimethoprim/sulfamethoxazole cannot be used for PCP prophylaxis.

Background: Cefepime and meropenem are used frequently in hospitalized patients for broad-spectrum empiric coverage, however, practitioners are often reluctant to prescribe these antibiotics for patients with a self-reported nonsevere, nontype I allergic reaction to penicillin. Methods: Retrospective review of electronic medical records of adults with a self-reported allergy to penicillin who received at least 1 dose of cefepime, ceftriaxone, cefoxitin, cephalexin, or meropenem to assess incidence and type of allergic reactions. Results: Of 175 patients included, 10 (6%) patients experienced an allergic reaction. The incidence for individual study drugs were cefepime 6% (6 of 96), meropenem 5% (3 of 56), cefoxitin 8% (1 of 13), ceftriaxone 0% (0 of 69), and cephalexin 0% (0 of 8). The majority of patients experienced a rash with or without pruritus and fever. Patients with a concomitant “sulfa” allergy (odds ratio [OR] 5.4, 95% confidence interval [CI] 1.4-21, P = .02) or ≥3 other drug allergies (OR 6.4, 95% CI 1.3-32, P = .025) were more likely to have an allergic reaction. Conclusions: In one of the largest retrospective reviews of hospitalized patients who received full dose therapy with cefepime, ceftriaxone, and meropenem, the incidence of allergic reactions was low and reactions were mild. Cefepime, ceftriaxone, and meropenem can be considered for use in patients with a self-reported nontype I penicillin allergy.

We describe a case ofBacteroides fragilisbacteremia associated with paraspinal and psoas abscesses in the United States. Resistance to b-lactam/b-lactamase inhibitors, carbapenems, and metronidazole was encountered despite having a recent travel history to India as the only possible risk factor for multidrug resistance. Microbiological cure was achieved with linezolid, moxifloxacin, and cefoxitin.

Background Viridans group streptococci (VGS) is an infrequent yet significant cause of bloodstream infections, and complicated cases may require prolonged antibiotic therapy. Ceftriaxone (CTX) and penicillin G (PCN G) are both considered first line options for VGS infections, but comparisons between these agents are limited. We evaluated the clinical outcomes amongst patients treated with CTX and PCN G for complicated VGS bacteremia. Methods This was a single-center, retrospective study of adult patients with ≥1 positive VGS blood culture who were treated with either CTX or PCN G/ampicillin (both included in PCN G arm) between January 2013 and June 2019. The primary outcome was a composite of safety endpoints, including hospital readmission due to VGS or an adverse event (AE) from therapy, Clostridioides difficile infections, treatment modification or discontinuation due to an antibiotic-related AE, and development of extended-spectrum beta lactamase resistance. Secondary outcomes included the individual safety endpoints, VGS bacteremia recurrence, hospital readmission, and all-cause mortality. Results Of 328 patients screened for inclusion, 94 patients met eligibility criteria (CTX n= 64, PCN G n=34). Median age was 68 years (IQR 56–81) and 68% were male. Study patients did not present with critical illness, as reflected by a median Pitt bacteremia score of 0 in the CTX and 1 in the PCN G arms, P=0.764. Streptococcus mitis was the most common VGS isolate and infective endocarditis (IE) was the predominant source of infection. CTX was not significantly associated with increased risk of the primary outcome (14% vs. 27%; P= 0.139). The driver of the composite outcome was hospital readmission due to VGS bacteremia or therapy complications. Results were similar in the subgroup of patients with IE (12.5% vs. 23.5%). No secondary endpoints differed significantly between groups. On multivariate analysis, source removal was a protective factor of the primary outcome (OR 0.1; 95% CI 0.020–0.6771; P= 0.017). Conclusion Despite potential safety concerns with the prolonged use of CTX in complicated VGS bacteremia, this study did not demonstrate a higher rate of treatment failure, adverse events, or resistance. These findings warrant further exploration. Disclosures All Authors: No reported disclosures

Background Secondary oral vancomycin prophylaxis (OVP) has been utilized in adults with a history of Clostridioides difficile infection (CDI) while receiving systemic antibiotics to prevent CDI recurrence. However, this practice is poorly described in pediatric patients. Rates of CDI recurrence in pediatric patients range from 10-40% and is associated with morbidity and mortality. This study assessed the efficacy and safety of secondary OVP in pediatric patients with subsequent antibiotic exposure. Methods This retrospective study evaluated pediatric patients ≤18 years with any history of clinical CDI and receiving systemic antibiotics in a subsequent encounter during the time period of 2013-2019. Patients who received OVP 10 mg/kg (up to 125 mg per dose) every 12 hours during concomitant antibiotics were compared to those who did not. The primary outcome was CDI recurrence within 8 weeks following antibiotic exposure. Secondary outcomes included time to recurrence, severity of recurrence, and isolation of vancomycin-resistant enterococci (VRE) from any site. Risk factors for CDI recurrence were assessed using logistic regression. Results A total of 153 patients were screened for inclusion, of which 32 and 47 patients were assigned to the OVP and no OVP group, respectively. Median age was 8.6 years and the most common comorbidities were malignancy (47%) and immunosuppression (46%). Median time since last CDI to study inclusion was 64.5 days in the OVP group and 90 days in the no OVP group, P=0.320. Compared to the no OVP group, OVP patients had longer hospital stays (5 vs 14 days, P=0.001) and more concomitant antibiotic exposure (8 vs 12.5 days, P=0.001). Median duration of OVP was 12 days. CDI recurrence occurred in 12 patients and was significantly lower in the OVP vs no OVP group (3.1% vs 23.4%; odds ratio, 0.106; 95% confidence interval, 0.013-0.864; P=0.022). VRE was not isolated in any patients. After adjustment in a multivariate analysis, only secondary OVP remained as a protective factor against recurrence (odds ratio, 0.082; 95% confidence interval, 0.009-0.748; P=0.027). Conclusion Secondary OVP effectively reduces the risk of recurrent CDI in pediatric patients with a history of CDI while receiving systemic antibiotics. Future prospective studies should validate these findings. Disclosures Cristian Merchan, PharMD, BCCCP, abbive (Speaker’s Bureau)

Background: Parameters within reconstitution, storage, stability, and administration may be optimized according to the unique pharmacokinetics of each antibiotic to ensure a successful desensitization. Objective: The study aims to evaluate the successfulness and safety of antibiotic desensitization protocols developed by the pharmacy department at our institution. Methods: A retrospective study was conducted at an 800-bed, urban, tertiary care, academic medical center. A total of 36 patients 18 years of age or older, admitted to our intensive care units between March 2013 and July 2017, who underwent antibiotic desensitization utilizing our pharmacy developed protocols were included. Results: In 36 patients, 61 desensitization cases were identified and included; 17 (47%) were male, 27 (75%) were Caucasian, and the median age was 55 years (range 19-94). In all, 15 different antibiotics were administered for desensitization, with meropenem (n = 12, 20%), ampicillin (n = 7, 11%), piperacillin/tazobactam (n = 7, 11%), and penicillin (n = 7, 11%) being the most common; 59 (97%) of 61 desensitizations were completed successfully with or without experiencing reactions, and 53 (89%) of the successful desensitization cases were completed without reactions. Two cases were categorized as anaphylaxis, which was severe enough to terminate the desensitization process. Of the 59 cases successfully completed, the 6 (10%) cases that experienced reactions were managed successfully during desensitization with completion of the process. Conclusion and Relevance: The findings suggest that our pharmacy-developed antibiotic desensitization protocols are successful and safe and may be adapted by other institutions.

Nephrotoxicity is a known adverse effect of polymyxin B (PMB). Animal data suggest that once-daily dosing may reduce the rate and delay the onset of acute kidney injury (AKI). In a multicenter retrospective study, we evaluated adult patients with a creatinine clearance (CrCl) of ≥30 ml/min who received ≥48 h of PMB therapy. The primary endpoint was the difference in rate of AKI comparing once- and twice-daily PMB dosing. The secondary endpoints included the time to AKI and the recovery of renal function. Of 273 eligible patients, 100 from each group were matched on the basis of propensity scores. In the matched groups, nephrotoxicity, defined according to risk, injury, failure, loss, and end-stage renal disease (RIFLE) criteria, was more frequent with once- than with twice-daily dosing (47% versus 17%, respectively; P = 0.0005). After adjusting for residual differences by multivariate conditional logistic regression, once-daily dosing was more likely to result in nephrotoxicity (adjusted odds ratio, 2.5; 95% confidence interval [CI], 1.413 to 4.541; P = 0.002). Among 64 patients who developed AKI, the median onsets were similar between the groups (7 days with once versus 6 days with twice-daily dosing, P = 0.095). Of 37 patients who had their serum creatinine evaluated subsequently, 29/37 (78%) had recovery of renal function. No patient required renal replacement therapy. Our findings suggest that AKI is significantly more common with PMB once daily than with twice-daily dosing with no difference in time to AKI. A prospective randomized study is warranted to validate these results.

Purpose: Leveraging pharmacy personnel resources for the purpose of antimicrobial stewardship program (ASP) operations presents a challenging task. We describe our experience integrating all pharmacists into an ASP, and evaluate the impact on ASP interventions, antimicrobial utilization, rate of selected hospital-onset infections and readmission. Summary: During a study period (January 1 to December 31, 2015), a total of 14 552 ASP-related pharmacy interventions were performed (ASP clinical pharmacotherapy specialists [CPS] n = 4025; non-ASP CPS n = 4888; hospital pharmacists n = 5639). Sixty percent of interventions by ASP CPS were initiated utilizing the dedicated ASP phone, and 40% through prospective audit and feedback. Non-ASP CPS performed interventions during bedside rounds (dose adjustment 23%, initiate new or alternative anti-infective 21%, discontinue antibiotic(s) 12%, therapeutic drug monitoring 11%, de-escalation 4%), whereas hospital pharmacists participated at the point of verification (dose adjustment 75%, restricted antibiotic verification 15%, and reporting major drug-drug interactions 4%). The acceptance rate of interventions by providers and clinicians was >90% for all groups. Annual aggregate antimicrobial use decreased by 6.4 days of therapy/1000 patient-days (DOT/1000 PD; P = 1.0). Ceftriaxone use increased by 8.4 DOT/1000 PD ( P = .029) without a significant compensatory increase in the use of antipseudomonal agents. Sustained low rates of hospital-onset Clostridium difficile (CDI) and carbapenem-resistant Enterobacteriaceae (CRE) infections were observed in 2015 compared with the prior year (1.1 and 1.2 cases/1000 PD, 0.2 and 0.1 cases/1000 PD, respectively). Thirty-day readmission rate decreased by 0.6% ( P = .019). Conclusions: Integration of all pharmacists into ASP activities based on the level of patient care and responsibilities is an effective strategy to expand clinical services provided by ASP.

BACKGROUND: Pediatric antimicrobial stewardship programs (ASPs) within larger institutions have unique opportunities to develop programs specialized to the needs of the pediatric program. In January 2013, our institution established a formalized pediatric ASP utilizing the prospective audit and feedback process. In an effort to standardize therapy and improve quality of care, members of the ASP developed evidence-based guidelines for management of common inpatient pediatric infections. ASP members met periodically with faculty and house staff to discuss guidelines and ways to improve prescribing. METHODS: Provider adherence with clinical inpatient practice guidelines, frequency of interventions suggested by ASP, and acceptance of interventions by providers were elements used to measure process change. We measured outcome data by analyzing antimicrobial utilization (defined as days of therapy) and length of therapy. RESULTS: Over a period of 2 years, institutional ASP guidelines were applicable to nearly half (44%) of all antimicrobial orders. Interventions were performed on 30% of all antimicrobial orders, of which 89% were accepted. Total antimicrobial days of therapy and length of therapy decreased significantly when comparing pre- and post-ASP. Overall, the susceptibility profiles of common bacterial pathogens to antibiotics remained stable. CONCLUSIONS: Pediatric ASPs within larger institutions have opportunities to create programs specific to the needs of the population they serve. We observed high rates of adherence by providers and a subsequent reduction in antibiotic utilization when implementing an audit feedback-based process.

We describe a case of a 72-year-old man with early-stage chronic lymphocytic leukemia (CLL) who presented with invasive nontyphoidal Salmonella (iNTS) infection, necrotizing pneumonia, and chronic infection of a hilar lymph node. Infection is a major cause of death in patients with CLL. Though few cases of iNTS infection associated with CLL have been described in the literature, to our knowledge this is the first reported case of iNTS-associated necrotizing pneumonia. Immunocompromised state in patients, even with early-stage CLL, likely predisposes them to invasive infection with intracellular organisms, such as Salmonella spp. In this case, successful treatment was achieved with prolonged course of intravenous followed by oral antibiotics without any surgical removal of infected focus.

Treatment of Legionnaires’ disease in severely ill or immunosuppressed patients presents a clinical challenge. Tigecycline (TG) achieves high concentrations intracellularly and has been shown to be effective against L. pneumophila in animal and cell models. We report our experience using TG as second-line therapy. Clinical response was seen in most patients after switching to TG alone or as a combination therapy.

Polymyxin B remains the last-line treatment option for multidrug-resistant Gram-negative bacterial infections. Current U.S. Food and Drug Administration-approved prescribing information recommends that polymyxin B dosing should be adjusted according to the patient's renal function, despite studies that have shown poor correlation between creatinine and polymyxin B clearance. The objective of the present study was to determine whether steady-state polymyxin B exposures in patients with normal renal function were different from those in patients with renal insufficiency. Nineteen adult patients who received intravenous polymyxin B (1.5 to 2.5 mg/kg [actual body weight] daily) were included. To measure polymyxin B concentrations, serial blood samples were obtained from each patient after receiving polymyxin B for at least 48 h. The primary outcome was polymyxin B exposure at steady state, as reflected by the area under the concentration-time curve (AUC) over 24 h. Five patients had normal renal function (estimated creatinine clearance [CL CR ] ≥ 80 ml/min) at baseline, whereas 14 had renal insufficiency (CL CR < 80 ml/min). The mean AUC of polymyxin B ± the standard deviation in the normal renal function cohort was 63.5 ± 16.6 mg·h/liter compared to 56.0 ± 17.5 mg·h/liter in the renal insufficiency cohort ( P = 0.42). Adjusting the AUC for the daily dose (in mg/kg of actual body weight) did not result in a significant difference (28.6 ± 7.0 mg·h/liter versus 29.7 ± 11.2 mg·h/liter, P = 0.80). Polymyxin B exposures in patients with normal and impaired renal function after receiving standard dosing of polymyxin B were comparable. Polymyxin B dosing adjustment in patients with renal insufficiency should be reexamined.

Background: Several nomograms include recommendations to give intravenous (IV) vancomycin at 8-hour dosing intervals (Q8H). However, there is a lack of detailed data regarding this dosing recommendation. Methods: A retrospective chart review of 100 patients who received 107 treatment courses of vancomycin Q8H for at least 5 days was performed. Distribution of vancomycin trough levels and rate of nephrotoxicity were evaluated. Results: Median patient age was 38 years (interquartile range [IQR] 27-50 years), median weight was 67 kg (IQR 55-79 kg), and median creatinine clearance was 124 mL/min (IQR 101-147 mL/min). Median duration of Q8H dosing was 9 days (IQR 7-12 days). Within the initial 96 hours, only 7% (7 of 104) of maximum trough concentrations were >20 mg/L (median dose 15 mg/kg [IQR 15-18 mg/kg]). After 96 hours of Q8H dosing, 34% (30 of 89) of maximum troughs were >20 mg/L (median dose 17 mg/kg [IQR 15-20 mg/kg]), P = .0005. The rate of nephrotoxicity was 4%. Conclusion: We observed an increase in the percentage of trough levels >20 mg/L later during treatment courses of vancomycin IV Q8H with a relatively small corresponding increase in vancomycin dose. Close monitoring of trough levels (eg, every 3 days) with prolonged courses of vancomycin IV Q8H is warranted.

The treatment of choice for Stenotrophomonas maltophilia is trimethoprim-sulfamethoxazole (SXT). Fluoroquinolones (FQs) have in vitro activity against S. maltophilia ; however, there is limited published information on their effectiveness. The purpose of this study is to compare the effectiveness of FQs and SXT for the treatment of S. maltophilia . A retrospective review of 98 patients with S. maltophilia infections who received SXT or FQ monotherapy was conducted. Patients ≥18 years old with a positive culture for S. maltophilia and clinical signs of infection who received treatment for ≥48 h were included. Microbiological cure and clinical response were evaluated at the end of therapy (EOT). In-hospital mortality and isolation of nonsusceptible isolates were also evaluated. Thirty-five patients received SXT, and 63 patients received FQ; 48 patients received levofloxacin, and 15 patients received ciprofloxacin. The most common infection was pulmonary. The overall microbiological cure rate at EOT was 63%. Thirteen of 20 patients (65%) who received SXT and 23 of 37 patients (62%) who received FQ had microbiological cure at EOT ( P = 0.832). The overall clinical success rate was 55%, 52% for those who received FQ and 61% for those who received SXT ( P = 0.451). In-hospital mortality was 24%, with similar rates in the two groups (25% for FQ versus 22% for SXT; P = 0.546). Development of resistance on repeat culture was 30% for FQ and 20% for SXT ( P = 0.426). Fluoroquinolone and SXT monotherapies may be equally effective for the treatment of S. maltophilia infections. Resistance was documented in subsequent isolates of S. maltophilia in both groups.

Background Cefpodoxime (CPD) and cefuroxime (CFX) are both oral cephalosporins indicated for urinary tract infection (UTI) treatment. CPD may have unfavorable pharmacokinetics (PK) given the lesser degree of renal excretion and urine concentration vs. CFX and risk of collateral damage. The objective of this study was to compare the efficacy and safety of these two agents for UTI treatment. Methods We conducted a retrospective evaluation among adult patients who received CPD or oral CFX for ≥48 hours for UTI treatment between January 2013 and July 2018. The primary outcome was the rate of subsequent UTI within 90 days following therapy. Safety outcomes included the rate of Clostridium difficile infection (CDI) and development of isolates resistant to third-generation cephalosporins (TGC) within 90 days. We also examined missed opportunities for antibiotic de-escalation in culture-positive patients. Results Of 747 patients assessed for study inclusion, 295 patients met eligibility criteria (CPD n = 165, CFX n = 130). Median age was 72 years (IQR 55–84) and 71% were female. More patients in the CPD vs. CFX group had pyelonephritis (29% vs. 11%, P = 0.0005) and were treated in the emergency department (42% vs. 16%, P = 0.0005). Escherichia coli was most commonly isolated (n = 139), followed by Klebsiella spp. The rate of subsequent UTI for CPD vs. CFX was 18% vs. 16%, P = 0.647 at median of 25 vs. 32 days, P = 0.399. CDI rate was 1% vs. 2%, P = 0.324 and resistance to TGC was detected in 4% vs. 1%, P = 0.068 for CPD vs. CFX, respectively. Missed opportunities to de-escalate antibiotics based on cultures were found in one-third of patients. After adjusting for multiple factors in multivariate analysis, genitourinary abnormality (Odds Ratio [OR] 2.2, 95% CI 1.10–4.29, P = 0.026) and prior history of UTI within 180 days (OR 2.2, 95% CI 1.08–4.398, P = 0.03), but not the choice of oral cephalosporin, were the only independent predictors of subsequent UTI. Conclusion Despite less favorable urinary PK of CPD compared with CFX, in this patient cohort, no differences in efficacy or safety between the two agents for UTI treatment were found. These findings warrant further exploration. Stewardship strategies for de-escalation from higher generation cephalosporins to narrow-spectrum antibiotics based on susceptibilities should be implemented. Disclosures All authors: No reported disclosures.

Background Trimethoprim/Sulfamethoxazole (TMP/SMX) is not routinely employed for urinary tract infections (UTI) with multi-drug-resistant organisms (MDRO) due to paucity of effectiveness data, concerns regarding inadequate urinary penetration, and risk of adverse effects. We describe our experience with TMP/SMX as definitive therapy for MDRO Enterobacteriaceae (MDRO-E). Methods We carried out a retrospective review of patients hospitalized at a tertiary care center and treated with TMP/SMX as definitive therapy for UTI with MDRO-E (as defined by resistance to third-generation cephalosporins in culture). We evaluated rates of overall cure rate (CR), adverse events (AE), recurrence (RC) and reinfection (RI). Repeat growth of same or different pathogen in urine culture (UC) within 30 days of completion of treatment was defined as RC or RI, respectively. Results 92 patients had 101 episodes of MDRO-E UTIs treated with TMP/SMX as initial (n = 26, 25.7%) or as step-down therapy (n = 23, 77%) after broad-spectrum empiric antimicrobials (ceftriaxone n = 22, cefepime n = 21, piperacillin/tazobactam n = 12, carbapenems n = 6, ciprofloxacin n = 3). 63 (68.5%) patients were 65 years or older. MDRO-E in 10 (9.9%) episodes were also resistant to carbapenems. Empiric therapy was appropriate in 56 (55.5%) episodes. Median duration of treatment was 8.5 (range 3–24) days for all antimicrobials and 7 (range 2–15) days for TMP-/SMX. Overall CR was 100%. RC/RI was seen in 23/101 (22.8%) episodes (RC n = 9; RI n = 14); UC data were available for 20 of which 8/20 (40%) had a TMP/SMX-resistant organism. 4 (3.9%) patients required readmission for a RC/RI UTI. In terms of AEs: 10 (9.9%) episodes of hyperkalemia (median maximum potassium level 4.5 mmol/L, range 2.7–6.4), 3 (2.9%) episodes of acute kidney injury, 5 episodes of Clostridium difficile infection, and 4 (3.9%) readmissions for a RC/RI UTI within 90 days. Conclusion Our findings suggest that TMP/SMX can be safe and effective as definitive therapy for ESBL-E UTI. The major AE are hyperkalemia and AKI, the incidence of which is high when TMP/SMX is used in combination with ACEI/ARBs. No clinical factors were found to be predictive of recurrence of reinfection. Disclosures All authors: No reported disclosures.

Background Clostridioides difficile is the most common hospital-acquired pathogen with an unchanged infection prevalence between 2011–2015. The data regarding the effectiveness of chemical prophylaxis to prevent recurrent C. difficile infection (CDI) are conflicting. Methods We conducted a retrospective study of hospitalized patients with CDI history in 2 New York academic hospitals over a 4.5-year period to determine the effectiveness of vancomycin prophylaxis for CDI prevention. The participating hospitals implemented an automated alert to providers recommending oral vancomycin 125 mg twice daily in patients with a history of CDI scheduled to receive any systemic antimicrobials for the duration of therapy and 5 days thereafter. Measured outcomes included the rate of breakthrough and recurrent CDI, defined as CDI during and in the one-month following prophylaxis, respectively. A self-controlled, before and after study design was employed to examine whether the use of oral vancomycin was associated with an increase in the prevalence of vancomycin-resistant Enterococcus species (VRE) both in absolute numbers and in comparison to vancomycin-sensitive Enterococcus species (VSE) in the period following vancomycin prophylaxis. Results 264 patients were included in the final analysis. Breakthrough CDI was identified in 17 (6.4%; 95% CIs 3.8%–10.1%) and recurrent CDI in 22 (8.3%; 95% CIs 5.3%–12.3%) patients. Of the 102 patients with a history of CDI within the 3 months preceding the administration of prophylaxis 4 (3.9%, 95% CIs 1.1%-9.7%) had breakthrough CDI and 9 had recurrent disease (8.3%, 95% CIs 5.3%–12.3%). In the 3 months following vancomycin prophylaxis there was an increase in both the absolute number of VRE and the ratio of VRE to VSE isolates compared with the combined period of 1.5 months preceding and the 3–4.5 months following the administration of prophylaxis. The increase in the absolute number of VRE colonized patients remained in the extended period of 6 months following prophylaxis. Conclusion Prophylactic vancomycin is an effective strategy to prevent CDI recurrence, but is associated with an increase in VRE colonization in the immediate period after administration. The risk of VRE infection should lead to careful selection of patients at the highest risk for CDI recurrence. Disclosures All authors: No reported disclosures.

Polymyxins are reserved for salvage therapy of infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP). Though synergy has been demonstrated for the combination of polymyxins with carbapenems or tigecycline, in vitro synergy tests are nonstandardized, and the clinical effect of synergy remains unclear. This study describes outcomes for patients with CRKP infections who were treated with polymyxin B monotherapy. We retrospectively reviewed the medical records of patients with CRKP infections who received polymyxin B monotherapy from 2007 to 2011. Clinical, microbiology, and antimicrobial treatment data were collected. Risk factors for treatment failure were identified by logistic regression. Forty patients were included in the analysis. Twenty-nine of 40 (73%) patients achieved clinical cure as defined by clinician-documented improvement in signs and symptoms of infections, and 17/32 (53%) patients with follow-up culture data achieved microbiological cure. End-of-treatment mortality was 10%, and 30-day mortality was 28%. In a multivariate analysis, baseline renal insufficiency was associated with a 6.0-fold increase in clinical failure after adjusting for septic shock (odds ratio [OR] = 6.0; 95% confidence interval [CI] = 1.22 to 29.59). Breakthrough infections with organisms intrinsically resistant to polymyxins occurred in 3 patients during the treatment. Eighteen of 40 (45%) patients developed a new CRKP infection a median of 23 days after initial polymyxin B treatment, and 3 of these 18 infections were polymyxin resistant. The clinical cure rate achieved in this retrospective study was 73% of patients with CRKP infections treated with polymyxin B monotherapy. Baseline renal insufficiency was a risk factor for treatment failure after adjusting for septic shock. Breakthrough infections with organisms intrinsically resistant to polymyxin B and development of resistance to polymyxin B in subsequent CRKP isolates are of concern.

The feasibility of fidaxomicin versus vancomycin and metronidazole (conventional therapy) was assessed in 59 transplant recipients with 61 episodes of Clostridium difficile -associated diarrhea (CDAD). Overall clinical cure was achieved in 86% of episodes, and in 7% of episodes, infection recurred. Fidaxomicin was well tolerated. Clinical cures were not significantly different compared with conventional therapy (67% versus 89%, respectively; P = 0.06). Univariate analysis of predictors for lack of clinical cure included continued use of broad-spectrum systemic antibiotics ( P = 0.026) and prior diagnosis of CDAD (95% confidence interval, 1.113 to 19.569; odds ratio, 4.667; P = 0.041). New-onset vancomycin-resistant Enterococcus (VRE) colonization was not noted after fidaxomicin therapy alone. However, this occurred in 10 of 28 patients (36%) following conventional therapy, and 2 of 3 patients with subsequent bacteremia died.