Implementation of Virtual Interactive Cases for Pharmacy Education: A Single-Center Experience

Patient case simulation software are described in pharmacy education literature as useful tools to improve skills in patient assessment (including medication history-taking and physical assessment), clinical reasoning and communication, and are typically well-received by students and instructors. The virtual interactive case (VIC) system is a web-based software developed to deliver deliberate practice opportunities in simulated patient encounters across a spectrum of clinical topics. This article describes the implementation and utilization of VIC in the undergraduate curriculum at one Canadian pharmacy school. Methods: At our facility, the use of VIC was integrated across the training spectrum in the curriculum, including core and elective didactic courses and practice labs, experiential learning, interprofessional education, and continuing education. Its use was evaluated through student and instructor surveys and qualitative student interviews). VIC is easy to navigate and created a positive and realistic learning environment. Students identified that it enhanced their ability to identify relevant patient information, accurately simulated hospital pharmacy practice and thereby helped them to prepare for their upcoming experiential courses. The use of VIC has expanded beyond its original intended purpose for individual student practice to become a valuable addition to pharmacy undergraduate education. Future plans include ongoing development of cases and exploration of further uses of VIC within the didactic curriculum, for remediation in experiential courses, and for pharmacist continuing education.

Pneumocystis jirovecii pneumonia in people living with HIV: a review

Pneumocystis jirovecii is a ubiquitous opportunistic fungus that can cause life-threatening pneumonia. People with HIV (PWH) who have low CD4 counts are one of the populations at the greatest risk of Pneumocystis jirovecii pneumonia (PCP). While guidelines have approached the diagnosis, prophylaxis, and management of PCP, the numerous studies of PCP in PWH are dominated by the 1980s and 1990s. As such, most studies have included younger male populations, despite PCP affecting both sexes and a broad age range. Many studies have been small and observational in nature, with an overall lack of randomized controlled trials. In many jurisdictions, and especially in low- and middle-income countries, the diagnosis can be challenging due to lack of access to advanced and/or invasive diagnostics. Worldwide, most patients will be treated with 21 days of high-dose trimethoprim sulfamethoxazole, although both the dose and the duration are primarily based on historical practice. Whether treatment with a lower dose is as effective and less toxic is gaining interest based on observational studies. Similarly, a 21-day tapering regimen of prednisone is used for patients with more severe disease, yet other doses, other steroids, or shorter durations of treatment with corticosteroids have not been evaluated. Now with the widespread availability of antiretroviral therapy, improved and less invasive PCP diagnostic techniques, and interest in novel treatment strategies, this review consolidates the scientific body of literature on the diagnosis and management of PCP in PWH, as well as identifies areas in need of more study and thoughtfully designed clinical trials.

Bring it on again: antimicrobial stewardship in transplant infectious diseases: updates and new challenges

Advancement in solid organ transplantation and hematopoietic stem cell transplant continues to improve the health outcomes of patients and widens the number of eligible patients who can benefit from the medical progress. Preserving the effectiveness of antimicrobials remains crucial, as otherwise transplant surgeries would be unsafe due to surgical site infections, and the risk of sepsis with neutropenia would preclude stem cell transplant. In this review, we provide updates on three previously discussed stewardship challenges: febrile neutropenia, Clostridioides difficile infection, and asymptomatic bacteriuria. We also offer insight into four new stewardship challenges: the applicability of the "shorter is better" paradigm shift to antimicrobial duration; antibiotic allergy delabeling and desensitization; colonization with multidrug-resistant gram-negative organisms; and management of cytomegalovirus infections. Specifically, data are accumulating for "shorter is better" and antibiotic allergy delabeling in transplant patients, following successes in the general population. Unique to transplant patients are the impact of multidrug-resistant organism colonization on clinical decision-making of antibiotic prophylaxis in transplant procedure and the need for antiviral stewardship in cytomegalovirus. We highlighted the expansion of antimicrobial stewardship interventions as potential solutions for these challenges, as well as gaps in knowledge and opportunities for further research.

Efficacy of zinc acetate hydrate for hypozincemia in the elderly is influenced by the initial accumulated exposure dose after taking zinc acetate hydrate

This study aimed to determine the efficacy of zinc acetate hydrate (ZAH) for hypozincemia in elderly hospitalized patients with an accumulated exposure of < 1000 mg of ZAH and to explore the factors affecting the therapeutic efficacy of ZAH. Seventy-four patients (mean age, 82 years) were enrolled in this study. All patients (n = 74) had low serum zinc levels (< 80 μg/dL), and the mean serum zinc concentration before ZAH administration was 53.6±10.7 μg/dL. The median serum zinc level (μg/dL) elevated per tablet (25 mg) of ZAH was 1.26 μg/dL, and the patients were divided into two groups, the slightly increased (< 1.26) and significantly increased (≥ 1.26) groups, based on the median cutoff value for the median increase in serum zinc level. A significant difference was found between the slightly increased (0.63±0.35 μg/dL, n = 36) and significantly increased (2.37±0.95 μg/dL, n = 38) groups (p < 0.0001, Wilcoxon rank-sum test). Logistic regression analysis with the accumulated exposure dose of ZAH, sex, and body weight as multivariate variables showed a significant difference in the accumulated exposure dose (total number of tablets per 25 mg: odds ratio, 1.119; 95% confidence interval, 1.052???1.203; p = 0.0009). There was no effect of underlying disease or of diet or zinc-containing intravenous or enteral nutrition on serum zinc levels. These results suggest that at an accumulated exposure of < 1000 mg of ZAH, serum zinc levels tend to increase with smaller accumulated doses. Therefore, serum zinc concentrations should be measured at the accumulated exposure to 500-1000 mg after ZAH initiation for the treatment of zinc deficiency in elderly hospitalized patients.

Coronavirus Disease 2019 Vaccination Is Associated With Reduced Outpatient Antibiotic Prescribing in Older Adults With Confirmed Severe Acute Respiratory Syndrome Coronavirus 2: A Population-Wide Cohort Study

BACKGROUND

Antibiotics are frequently prescribed unnecessarily in outpatients with coronavirus disease 2019 (COVID-19). We sought to evaluate factors associated with antibiotic prescribing in outpatients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

METHODS

We performed a population-wide cohort study of outpatients aged ≥66 years with polymerase chain reaction-confirmed SARS-CoV-2 from 1 January 2020 to 31 December 2021 in Ontario, Canada. We determined rates of antibiotic prescribing within 1 week before (prediagnosis) and 1 week after (postdiagnosis) reporting of the positive SARS-CoV-2 result, compared to a self-controlled period (baseline). We evaluated predictors of prescribing, including a primary-series COVID-19 vaccination, in univariate and multivariable analyses.

RESULTS

We identified 13 529 eligible nursing home residents and 50 885 eligible community-dwelling adults with SARS-CoV-2 infection. Of the nursing home and community residents, 3020 (22%) and 6372 (13%), respectively, received at least 1 antibiotic prescription within 1 week of a SARS-CoV-2 positive result. Antibiotic prescribing in nursing home and community residents occurred, respectively, at 15.0 and 10.5 prescriptions per 1000 person-days prediagnosis and 20.9 and 9.8 per 1000 person-days postdiagnosis, higher than the baseline rates of 4.3 and 2.5 prescriptions per 1000 person-days. COVID-19 vaccination was associated with reduced prescribing in nursing home and community residents, with adjusted postdiagnosis incidence rate ratios (95% confidence interval) of 0.7 (0.4-1) and 0.3 (0.3-0.4), respectively.

CONCLUSIONS

Antibiotic prescribing was high and with little or no decline following SARS-CoV-2 diagnosis but was reduced in COVID-19-vaccinated individuals, highlighting the importance of vaccination and antibiotic stewardship in older adults with COVID-19.

Vancomycin Therapeutic Drug Monitoring: A Cross-Sectional Survey of Canadian Hospitals

Background

Little is known about the current landscape of vancomycin therapeutic drug monitoring (TDM) in Canadian hospitals, which operate within publicly funded health care systems.

Objectives

To determine current TDM practices for vancomycin and associated challenges and to gather perceptions about TDM based on area under the concentration-time curve (AUC) in Canadian hospitals.

Methods

An electronic survey was distributed to hospital pharmacists in spring 2021 through multiple national and provincial antimicrobial stewardship, public health, and pharmacy organizations. The survey gathered data about hospital characteristics, TDM methods, inclusion criteria for patient selection, pharmacokinetic and pharmacodynamic targets, vancomycin susceptibility testing and reporting, and perceived barriers and challenges.

Results

In total, 120 pharmacists from 10 of the 13 provincial and territorial jurisdictions in Canada, representing 12.5% of Canadian acute care hospitals (n = 962), completed at least 90% of survey questions. The predominant TDM method was trough-based (107/119, 89.9%); another 10.1% of respondents (12/119) reported performing AUC-based TDM (with or without trough-based TDM), and 17.9% (19/106) of those not already using AUC-based TDM were considering implementing it within 1 to 2 years. Among hospitals performing trough-based TDM, 60.5% (66/109) targeted trough levels between 15 and 20 mg/L for serious infections with methicillin-resistant Staphylococcus aureus. One-quarter of the respondents using this method (27/109, 24.8%) agreed that trough-based TDM was of uncertain benefit, and about one-third (33/109, 30.3%) were neutral on this question. Multiple challenges were identified for trough-based TDM, including sub- or supra-therapeutic concentrations and collection of specimens at inappropriate times. Overall, 40.5% (47/116) of respondents agreed that AUC-based TDM was likely safer than trough-based TDM, whereas 23.3% (27/116) agreed that AUC-based TDM was likely more effective.

Conclusions

This survey represents a first step in developing evidence-based, standardized best practices for vancomycin TDM that are uniquely suited to the Canadian health care system.

Validation of the Antifungal National Antimicrobial Prescribing Survey (AF-NAPS) quality assessment tool

BACKGROUND

The Antifungal National Antimicrobial Prescribing Survey (AF-NAPS) was developed to undertake streamlined quality audits of antifungal prescribing. The validity and reliability of such tools is not characterized.

OBJECTIVES

To assess the validity and reliability of the AF-NAPS quality assessment tool.

METHODS

Case vignettes describing antifungal prescribing were prepared. A steering group was assembled to determine gold-standard classifications for appropriateness and guideline compliance. Infectious diseases physicians, antimicrobial stewardship (AMS) and specialist pharmacists undertook a survey to classify appropriateness and guideline compliance of prescriptions utilizing the AF-NAPS tool. Validity was measured as accuracy, sensitivity and specificity compared with gold standard. Inter-rater reliability was measured using Fleiss' kappa statistics. Assessors' responses and comments were thematically analysed to determine reasons for incorrect classification.

RESULTS

Twenty-eight clinicians assessed 59 antifungal prescriptions. Overall accuracy of appropriateness assessment was 77.0% (sensitivity 85.3%, specificity 68.0%). Highest accuracy was seen amongst specialist (81%) and AMS pharmacists (79%). Prescriptions with lowest accuracy were in the haematology setting (69%), use of echinocandins (73%), mould-active azoles (75%) and for prophylaxis (71%). Inter-rater reliability was fair overall (0.3906), with moderate reliability amongst specialist pharmacists (0.5304). Barriers to accurate classification were incorrect use of the appropriateness matrix, knowledge gaps and lack of guidelines for some indications.

CONCLUSIONS

The AF-NAPS is a valid tool, assisting assessors to correctly classify appropriate prescriptions more accurately than inappropriate prescriptions. Specialist and AMS pharmacists had similar performance, providing confidence that both can undertake AF-NAPS audits to a high standard. Identified reasons for incorrect classification will be targeted in the online tool and educational materials.

Antibiotic resistance associated with the COVID-19 pandemic: a systematic review and meta-analysis

BACKGROUND

COVID-19 and antimicrobial resistance (AMR) are two intersecting global public health crises.

OBJECTIVE

We aimed to describe the impact of the COVID-19 pandemic on AMR across health care settings.

DATA SOURCE

A search was conducted in December 2021 in WHO COVID-19 Research Database with forward citation searching up to June 2022.

STUDY ELIGIBILITY

Studies evaluating the impact of COVID-19 on AMR in any population were included and influencing factors were extracted. Reporting of enhanced infection prevention and control and/or antimicrobial stewardship programs was noted.

METHODS

Pooling was done separately for Gram-negative and Gram-positive organisms. Random-effects meta-analysis was performed.

RESULTS

Of 6036 studies screened, 28 were included and 23 provided sufficient data for meta-analysis. The majority of studies focused on hospital settings (n = 25, 89%). The COVID-19 pandemic was not associated with a change in the incidence density (incidence rate ratio 0.99, 95% CI: 0.67-1.47) or proportion (risk ratio 0.91, 95% CI: 0.55-1.49) of methicillin-resistant Staphylococcus aureus or vancomycin-resistant enterococci cases. A non-statistically significant increase was noted for resistant Gram-negative organisms (i.e. extended-spectrum beta-lactamase, carbapenem-resistant Enterobacterales, carbapenem or multi-drug resistant or carbapenem-resistant Pseudomonas aeruginosa or Acinetobacter baumannii, incidence rate ratio 1.64, 95% CI: 0.92-2.92; risk ratio 1.08, 95% CI: 0.91-1.29). The absence of reported enhanced infection prevention and control and/or antimicrobial stewardship programs initiatives was associated with an increase in gram-negative AMR (risk ratio 1.11, 95% CI: 1.03-1.20). However, a test for subgroup differences showed no statistically significant difference between the presence and absence of these initiatives (p 0.40).

CONCLUSION

The COVID-19 pandemic may have hastened the emergence and transmission of AMR, particularly for Gram-negative organisms in hospital settings. But there is considerable heterogeneity in both the AMR metrics used and the rate of resistance reported across studies. These findings reinforce the need for strengthened infection prevention, antimicrobial stewardship, and AMR surveillance in the context of the COVID-19 pandemic.

Antimicrobial resistance in patients with COVID-19: a systematic review and meta-analysis

BACKGROUND

Frequent use of antibiotics in patients with COVID-19 threatens to exacerbate antimicrobial resistance. We aimed to establish the prevalence and predictors of bacterial infections and antimicrobial resistance in patients with COVID-19.

METHODS

We did a systematic review and meta-analysis of studies of bacterial co-infections (identified within ≤48 h of presentation) and secondary infections (>48 h after presentation) in outpatients or hospitalised patients with COVID-19. We searched the WHO COVID-19 Research Database to identify cohort studies, case series, case-control trials, and randomised controlled trials with populations of at least 50 patients published in any language between Jan 1, 2019, and Dec 1, 2021. Reviews, editorials, letters, pre-prints, and conference proceedings were excluded, as were studies in which bacterial infection was not microbiologically confirmed (or confirmed via nasopharyngeal swab only). We screened titles and abstracts of papers identified by our search, and then assessed the full text of potentially relevant articles. We reported the pooled prevalence of bacterial infections and antimicrobial resistance by doing a random-effects meta-analysis and meta-regression. Our primary outcomes were the prevalence of bacterial co-infection and secondary infection, and the prevalence of antibiotic-resistant pathogens among patients with laboratory-confirmed COVID-19 and bacterial infections. The study protocol was registered with PROSPERO (CRD42021297344).

FINDINGS

We included 148 studies of 362  976 patients, which were done between December, 2019, and May, 2021. The prevalence of bacterial co-infection was 5·3% (95% CI 3·8-7·4), whereas the prevalence of secondary bacterial infection was 18·4% (14·0-23·7). 42 (28%) studies included comprehensive data for the prevalence of antimicrobial resistance among bacterial infections. Among people with bacterial infections, the proportion of infections that were resistant to antimicrobials was 60·8% (95% CI 38·6-79·3), and the proportion of isolates that were resistant was 37·5% (26·9-49·5). Heterogeneity in the reported prevalence of antimicrobial resistance in organisms was substantial (I2=95%).

INTERPRETATION

Although infrequently assessed, antimicrobial resistance is highly prevalent in patients with COVID-19 and bacterial infections. Future research and surveillance assessing the effect of COVID-19 on antimicrobial resistance at the patient and population level are urgently needed.

FUNDING

WHO.

A national survey of antimicrobial stewardship content in Canadian entry-to-practice pharmacy programs

Objective

To describe the current landscape of antimicrobial stewardship (AMS) instruction in Canadian entry-to-practice pharmacy programs and the perceived barriers and facilitators to optimizing teaching and learning.

Design

Electronic survey.

Participants

Faculty representatives from the 10 Canadian entry-to-practice pharmacy programs, including content experts and faculty leadership.

Methods

A review of international literature pertaining to AMS in pharmacy curricula informed a 24-item survey, which was open for completion from March to May of 2021. Curriculum content questions were developed using AMS topics recommended by pharmacy educators in the United States, and professional roles described by the Association of Faculties of Pharmacy of Canada.

Results

All 10 Canadian faculties returned a completed survey. All programs reported teaching AMS principles in their core curricula. Content coverage varied, with programs teaching, on average, 68% of the recommended AMS topics from the United States. Potential gaps were identified within the professional roles of "communicator" and "collaborator." Didactic methods of content delivery and student assessment, such as lectures and multiple-choice questions, were most frequently used. Three programs offered additional AMS content in their elective curricula. Experiential rotations in AMS were commonly offered, though teaching AMS in formalized interprofessional settings was rare. Curricular time constraints were identified by all programs as a barrier to enhancing AMS instruction. A course to teach AMS, a curriculum framework, and prioritization by the faculty's curriculum committee were perceived as facilitators.

Conclusions

Our findings highlight potential gaps and areas of opportunity within Canadian pharmacy AMS instruction.

Low-dose trimethoprim-sulfamethoxazole for the treatment of Pneumocystis jirovecii pneumonia (LOW-TMP): protocol for a phase III randomised, placebo-controlled, dose-comparison trial

INTRODUCTION

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection of immunocompromised hosts with significant morbidity and mortality. The current standard of care, trimethoprim-sulfamethoxazole (TMP-SMX) at a dose of 15-20 mg/kg/day, is associated with serious adverse drug events (ADE) in 20%-60% of patients. ADEs include hypersensitivity reactions, drug-induced liver injury, cytopenias and renal failure, all of which can be treatment limiting. In a recent meta-analysis of observational studies, reduced dose TMP-SMX for the treatment of PJP was associated with fewer ADEs, without increased mortality.

METHODS AND ANALYSIS

A phase III randomised, placebo-controlled, trial to directly compare the efficacy and safety of low-dose TMP-SMX (10 mg/kg/day of TMP) with the standard of care (15 mg/kg/day of TMP) among patients with PJP, for a composite primary outcome of change of treatment, new mechanical ventilation, or death. The trial will be undertaken at 16 Canadian hospitals. Data will be analysed as intention to treat. Primary and secondary outcomes will be compared using logistic regression adjusting for stratification and presented with 95% CI.

ETHICS AND DISSEMINATION

This study has been conditionally approved by the McGill University Health Centre; Ethics approval will be obtained from all participating centres. Results will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04851015.

Investigating the efficacy of baricitinib in new onset type 1 diabetes mellitus (BANDIT)—study protocol for a phase 2, randomized, placebo controlled trial

Background

Type 1 diabetes (T1D) places an extraordinary burden on individuals and their families, as well as on the healthcare system. Despite recent advances in glucose sensors and insulin pump technology, only a minority of patients meet their glucose targets and face the risk of both acute and long-term complications, some of which are life-threatening.

The JAK-STAT pathway is critical for the immune-mediated pancreatic beta cell destruction in T1D. Our pre-clinical data show that inhibitors of JAK1/JAK2 prevent diabetes and reverse newly diagnosed diabetes in the T1D non-obese diabetic mouse model. The goal of this study is to determine if the JAK1/JAK2 inhibitor baricitinib impairs type 1 diabetes autoimmunity and preserves beta cell function.

Methods

This will be as a multicentre, two-arm, double-blind, placebo-controlled randomized trial in individuals aged 10–30 years with recent-onset T1D. Eighty-three participants will be randomized in a 2:1 ratio within 100 days of diagnosis to receive either baricitinib 4mg/day or placebo for 48 weeks and then monitored for a further 48 weeks after stopping study drug. The primary outcome is the plasma C-peptide 2h area under the curve following ingestion of a mixed meal. Secondary outcomes include HbA1c, insulin dose, continuous glucose profile and adverse events. Mechanistic assessments will characterize general and diabetes-specific immune responses.

Discussion

This study will determine if baricitinib slows the progressive, immune-mediated loss of beta cell function that occurs after clinical presentation of T1D. Preservation of beta cell function would be expected to improve glucose control and prevent diabetes complications, and justify additional trials of baricitinib combined with other therapies and of its use in at-risk populations to prevent T1D.

Trial registration

ANZCTR ACTRN12620000239965. Registered on 26 February 2020. ClinicalTrials.gov NCT04774224. Registered on 01 March 2021

Use of Novel Strategies to Develop Guidelines for Management of Pyogenic Osteomyelitis in Adults: A WikiGuidelines Group Consensus Statement

IMPORTANCE

Traditional approaches to practice guidelines frequently result in dissociation between strength of recommendation and quality of evidence.

OBJECTIVE

To construct a clinical guideline for pyogenic osteomyelitis management, with a new standard of evidence to resolve the gap between strength of recommendation and quality of evidence, through the use of a novel open access approach utilizing social media tools.

EVIDENCE REVIEW

This consensus statement and systematic review study used a novel approach from the WikiGuidelines Group, an open access collaborative research project, to construct clinical guidelines for pyogenic osteomyelitis. In June 2021 and February 2022, authors recruited via social media conducted multiple PubMed literature searches, including all years and languages, regarding osteomyelitis management; criteria for article quality and inclusion were specified in the group's charter. The GRADE system for evaluating evidence was not used based on previously published concerns regarding the potential dissociation between strength of recommendation and quality of evidence. Instead, the charter required that clear recommendations be made only when reproducible, prospective, controlled studies provided hypothesis-confirming evidence. In the absence of such data, clinical reviews were drafted to discuss pros and cons of care choices. Both clear recommendations and clinical reviews were planned with the intention to be regularly updated as new data become available.

FINDINGS

Sixty-three participants with diverse expertise from 8 countries developed the group's charter and its first guideline on pyogenic osteomyelitis. These participants included both nonacademic and academic physicians and pharmacists specializing in general internal medicine or hospital medicine, infectious diseases, orthopedic surgery, pharmacology, and medical microbiology. Of the 7 questions addressed in the guideline, 2 clear recommendations were offered for the use of oral antibiotic therapy and the duration of therapy. In addition, 5 clinical reviews were authored addressing diagnosis, approaches to osteomyelitis underlying a pressure ulcer, timing for the administration of empirical therapy, specific antimicrobial options (including empirical regimens, use of antimicrobials targeting resistant pathogens, the role of bone penetration, and the use of rifampin as adjunctive therapy), and the role of biomarkers and imaging to assess responses to therapy.

CONCLUSIONS AND RELEVANCE

The WikiGuidelines approach offers a novel methodology for clinical guideline development that precludes recommendations based on low-quality data or opinion. The primary limitation is the need for more rigorous clinical investigations, enabling additional clear recommendations for clinical questions currently unresolved by high-quality data.

Challenges of Antimicrobial Resistance and Stewardship in Solid Organ Transplant Patients

Purpose of Review

Without effective antimicrobials, patients cannot undergo transplant surgery safely or sustain immunosuppressive therapy. This review examines the burden of antimicrobial resistance in solid organ transplant recipients and identifies opportunities for antimicrobial stewardship.

Recent Findings

Antimicrobial resistance has been identified to be the leading cause of death globally. Multidrug-resistant pathogens are associated with significant morbidity and mortality in transplant recipients. Methicillin-resistant S. aureus affects liver and lung recipients, causing bacteremia, pneumonia, and surgical site infections. Vancomycin-resistant enterococci is a nosocomial pathogen primarily causing bacteremia in liver recipients. Multidrug-resistant Gram-negative pathogens present urgent and serious threats to transplant recipients. Extended-spectrum beta-lactamase-producing E. coli and K. pneumoniae commonly cause bacteremia and intra-abdominal infections in liver and kidney recipients. Carbapenemase-producing Enterobacterales, mainly K. pneumoniae, are responsible for infections early-post transplant in liver, lung, kidney, and heart recipients. P. aeruginosa and A. baumannii continue to be critical threats. While there are new antimicrobial agents targeting resistant pathogens, judicious prescribing is crucial to minimize emerging resistance. The full implications of the COVID-19 global pandemic on antimicrobial resistance in transplant recipients remain to be understood. Currently, there are no established standards on the implementation of antimicrobial stewardship interventions, but strategies that leverage existing antimicrobial stewardship program structure while tailoring to the needs of transplant recipients may help to optimize antimicrobial use.

Summary

Clinicians caring for transplant recipients face unique challenges tackling emerging antimcirobial resistance. Coordinated antimicrobial stewardship interventions in collaboration with appropriate expertise in transplant and infectious diseases may mitigate against such threats.

Bring it on: Top five antimicrobial stewardship challenges in transplant infectious diseases and practical strategies to address them

Antimicrobial therapies are essential tools for transplant recipients who are at high risk for infectious complications. However, judicious use of antimicrobials is critical to preventing the development of antimicrobial resistance. Treatment of multidrug-resistant organisms is challenging and potentially leads to therapies with higher toxicities, intravenous access, and intensive drug monitoring for interactions. Antimicrobial stewardship programs are crucial in the prevention of antimicrobial resistance, though balancing these strategies with the need for early and frequent antibiotic therapy in these immunocompromised patients can be challenging. In this review, we summarize 5 frequently encountered transplant infectious disease stewardship challenges, and we suggest strategies to improve practices for each clinical syndrome. These 5 challenging areas are: asymptomatic bacteriuria in kidney transplant recipients, febrile neutropenia in hematopoietic stem cell transplantation, antifungal prophylaxis in liver and lung transplantation, treatment of left-ventricular assist device infections, and Clostridioides difficile infection in solid-organ and hematopoietic stem-cell transplant recipients. Common themes contributing to these challenges include limited data specific to transplant patients, shortcomings in diagnostic testing, and uncertainties in pharmacotherapy.

Antibiotic prescribing patterns among patients admitted to an academic teaching hospital for COVID-19 during the first wave of the pandemic in Toronto: A retrospective, controlled study

BACKGROUND

Empirical antibiotics are not recommended for coronavirus disease 2019 (COVID-19).

METHODS

In this retrospective study, patients admitted to Toronto General Hospital's general internal medicine from the emergency department for COVID-19 between March 1 and August 31, 2020 were compared with those admitted for community-acquired pneumonia (CAP) in 2020 and 2019 in the same months. The primary outcome was antibiotics use pattern: prevalence and concordance with COVID-19 or CAP guidelines. The secondary outcome was antibiotic consumption in days of therapy (DOT)/100 patient-days. We extracted data from electronic medical records. We used logistic regression to model the association between disease and receipt of antibiotics, linear regression to compare DOT.

RESULTS

The COVID-19, CAP 2020, and CAP 2019 groups had 67, 73, and 120 patients, respectively. Median age was 71 years; 58.5% were male. Prevalence of antibiotic use was 70.2%, 97.3%, and 90.8% for COVID-19, CAP 2020, and CAP 2019, respectively. Compared with CAP 2019, the adjusted odds ratio (aOR) for receiving antibiotics was 0.23 (95% CI 0.10 to 0.53, p = 0.001) and 3.42 (95% CI 0.73 to 15.95, p = 0.117) for COVID-19 and CAP 2020, respectively. Among patients receiving antibiotics within 48 hours of admission, compared with CAP 2019, the aOR for guideline-concordant combination regimens was 2.28 (95% CI 1.08 to 4.83, p = 0.031) for COVID-19, and 1.06 (95% CI 0.55 to 2.05, p = 0.856) for CAP 2020. Difference in mean DOT/100 patient-days was -24.29 (p = 0.009) comparing COVID-19 with CAP 2019, and +28.56 (p = 0.003) comparing CAP 2020 with CAP 2019.

CONCLUSIONS

There are opportunities for antimicrobial stewardship to address unnecessary antibiotic use.

White paper on antimicrobial stewardship in solid organ transplant recipients

Antimicrobial stewardship programs (ASPs) have made immense strides in optimizing antibiotic, antifungal, and antiviral use in clinical settings. However, although ASPs are required institutionally by regulatory agencies in the United States and Canada, they are not mandated for transplant centers or programs specifically. Despite the fact that solid organ transplant recipients in particular are at increased risk of infections from multidrug-resistant organisms, due to host and donor factors and immunosuppressive therapy, there currently are little rigorous data regarding stewardship practices in solid organ transplant populations, and thus, no transplant-specific requirements currently exist. Further complicating matters, transplant patients have a wide range of variability regarding their susceptibility to infection, as factors such as surgery of transplant, intensity of immunosuppression, and presence of drains or catheters in situ may modify the risk of infection. As such, it is not feasible to have a "one-size-fits-all" style of stewardship for this patient population. The objective of this white paper is to identify opportunities, risk factors, and ASP strategies that should be assessed with solid organ transplant recipients to optimize antimicrobial use, while producing an overall improvement in patient outcomes. We hope it may serve as a springboard for development of future guidance and identification of research opportunities.

Patterns of Antimicrobial Use in an Outpatient Hemodialysis Unit

BACKGROUND

Patients receiving hemodialysis (HD) are at high risk of infections, including those caused by multidrug-resistant organisms. Given that antimicrobial exposure is a major risk factor for the emergence of these resistant organisms, minimizing inappropriate use is imperative. To optimize use, it is important to understand patterns of antimicrobial prescribing in this setting.

OBJECTIVES

To measure antimicrobial use and to describe prescribing patterns among patients receiving outpatient HD.

METHODS

A retrospective observational case series study was performed in an outpatient HD unit from February to April 2017. Adults for whom at least 1 antimicrobial was prescribed were included. The primary outcome was total antimicrobial days of therapy (DOT) per 1000 patient-days. Secondary outcomes were the characteristics of the antimicrobial prescriptions, in terms of antimicrobial class, indication, purpose, route, and prescriber group.

RESULTS

Antimicrobials were prescribed for 53 (16%) of the 330 patients treated in the HD unit during the study period; the total number of prescriptions was 75. Antimicrobial use was 27.5 DOTs/1000 patient-days. Fluoroquinolones were the most frequently prescribed type of antimicrobial (n = 17, 23%), whereas the second most frequently prescribed were first-generation cephalosporins (n = 16, 21%). The most common indication was skin or soft-tissue infection (n = 14, 19%), followed by bloodstream infection (n = 13, 17%). Of the 75 antimicrobials, 48 (64%) were prescribed for empiric therapy, 19 (25%) for targeted therapy, and 8 (11%) for prophylaxis. Two-thirds of the antimicrobials prescribed (n = 50, 67%) were oral medications, and most (n = 72, 96%) were ordered by hospital prescribers.

CONCLUSIONS

Antimicrobial use was common in this study setting, with 1 in 6 HD patients receiving this type of medication. The findings of this study create opportunities to standardize antimicrobial prescribing at the local level for common infections that occur in patients receiving outpatient HD.

OUP accepted manuscript

The National Antimicrobial Prescribing Survey (NAPS) is a web-based qualitative auditing platform that provides a standardized and validated tool to assist hospitals in assessing the appropriateness of antimicrobial prescribing practices. Since its release in 2013, the NAPS has been adopted by all hospital types within Australia, including public and private facilities, and supports them in meeting the national standards for accreditation. Hospitals can generate real-time reports to assist with local antimicrobial stewardship (AMS) activities and interventions. De-identified aggregate data from the NAPS are also submitted to the Antimicrobial Use and Resistance in Australia surveillance system, for national reporting purposes, and to strengthen national AMS strategies. With the successful implementation of the programme within Australia, the NAPS has now been adopted by countries with both well-resourced and resource-limited healthcare systems. We provide here a narrative review describing the experience of users utilizing the NAPS programme in Canada, Malaysia and Bhutan. We highlight the key barriers and facilitators to implementation and demonstrate that the NAPS methodology is feasible, generalizable and translatable to various settings and able to assist in initiatives to optimize the use of antimicrobials.

Predictors and microbiology of respiratory and bloodstream bacterial infection in patients with COVID-19: living rapid review update and meta-regression

Background

The prevalence of bacterial infection in patients with COVID-19 is low, however, empiric antibiotic use is high. Risk stratification may be needed to minimize unnecessary empiric antibiotic use.

Objective

To identify risk factors and microbiology associated with respiratory and bloodstream bacterial infection in patients with COVID-19.

Data sources

We searched MEDLINE, OVID Epub and EMBASE for published literature up to 5 February 2021.

Study eligibility criteria

Studies including at least 50 patients with COVID-19 in any healthcare setting.

Methods

We used a validated ten-item risk of bias tool for disease prevalence. The main outcome of interest was the proportion of COVID-19 patients with bloodstream and/or respiratory bacterial co-infection and secondary infection. We performed meta-regression to identify study population factors associated with bacterial infection including healthcare setting, age, comorbidities and COVID-19 medication.

Results

Out of 33 345 studies screened, 171 were included in the final analysis. Bacterial infection data were available from 171 262 patients. The prevalence of co-infection was 5.1% (95% CI 3.6–7.1%) and secondary infection was 13.1% (95% CI 9.8–17.2%). There was a higher odds of bacterial infection in studies with a higher proportion of patients in the intensive care unit (ICU) (adjusted OR 18.8, 95% CI 6.5–54.8). Female sex was associated with a lower odds of secondary infection (adjusted OR 0.73, 95% CI 0.55–0.97) but not co-infection (adjusted OR 1.05, 95% CI 0.80–1.37). The most common organisms isolated included Staphylococcus aureus, coagulase-negative staphylococci and Klebsiella species.

Conclusions

While the odds of respiratory and bloodstream bacterial infection are low in patients with COVID-19, meta-regression revealed potential risk factors for infection, including ICU setting and mechanical ventilation. The risk for secondary infection is substantially greater than the risk for co-infection in patients with COVID-19. Understanding predictors of co-infection and secondary infection may help to support improved antibiotic stewardship in patients with COVID-19.

The Impact of COVID-19 on Outpatient Antibiotic Prescriptions in Ontario, Canada; An Interrupted Time Series Analysis

Background

The coronavirus disease 2019 (COVID-19) pandemic has potentially impacted outpatient antibiotic prescribing. Investigating this impact may identify stewardship opportunities in the ongoing COVID-19 period and beyond.

Methods

We conducted an interrupted time series analysis on outpatient antibiotic prescriptions and antibiotic prescriptions/patient visits in Ontario, Canada, between January 2017 and December 2020 to evaluate the impact of the COVID-19 pandemic on population-level antibiotic prescribing by prescriber specialty, patient demographics, and conditions.

Results

In the evaluated COVID-19 period (March–December 2020), there was a 31.2% (95% CI, 27.0% to 35.1%) relative reduction in total antibiotic prescriptions. Total outpatient antibiotic prescriptions decreased during the COVID-19 period by 37.1% (95% CI, 32.5% to 41.3%) among family physicians, 30.7% (95% CI, 25.8% to 35.2%) among subspecialist physicians, 12.1% (95% CI, 4.4% to 19.2%) among dentists, and 25.7% (95% CI, 21.4% to 29.8%) among other prescribers. Antibiotics indicated for respiratory infections decreased by 43.7% (95% CI, 38.4% to 48.6%). Total patient visits and visits for respiratory infections decreased by 10.7% (95% CI, 5.4% to 15.6%) and 49.9% (95% CI, 43.1% to 55.9%). Total antibiotic prescriptions/1000 visits decreased by 27.5% (95% CI, 21.5% to 33.0%), while antibiotics indicated for respiratory infections/1000 visits with respiratory infections only decreased by 6.8% (95% CI, 2.7% to 10.8%).

Conclusions

The reduction in outpatient antibiotic prescribing during the COVID-19 pandemic was driven by less antibiotic prescribing for respiratory indications and largely explained by decreased visits for respiratory infections.

Bacterial co-infection and secondary infection in patients with COVID-19: a living rapid review and meta-analysis

BACKGROUND

Bacterial co-pathogens are commonly identified in viral respiratory infections and are important causes of morbidity and mortality. The prevalence of bacterial infection in patients infected with SARS-CoV-2 is not well understood.

AIMS

To determine the prevalence of bacterial co-infection (at presentation) and secondary infection (after presentation) in patients with COVID-19.

SOURCES

We performed a systematic search of MEDLINE, OVID Epub and EMBASE databases for English language literature from 2019 to April 16, 2020. Studies were included if they (a) evaluated patients with confirmed COVID-19 and (b) reported the prevalence of acute bacterial infection.

CONTENT

Data were extracted by a single reviewer and cross-checked by a second reviewer. The main outcome was the proportion of COVID-19 patients with an acute bacterial infection. Any bacteria detected from non-respiratory-tract or non-bloodstream sources were excluded. Of 1308 studies screened, 24 were eligible and included in the rapid review representing 3338 patients with COVID-19 evaluated for acute bacterial infection. In the meta-analysis, bacterial co-infection (estimated on presentation) was identified in 3.5% of patients (95%CI 0.4-6.7%) and secondary bacterial infection in 14.3% of patients (95%CI 9.6-18.9%). The overall proportion of COVID-19 patients with bacterial infection was 6.9% (95%CI 4.3-9.5%). Bacterial infection was more common in critically ill patients (8.1%, 95%CI 2.3-13.8%). The majority of patients with COVID-19 received antibiotics (71.9%, 95%CI 56.1 to 87.7%).

IMPLICATIONS

Bacterial co-infection is relatively infrequent in hospitalized patients with COVID-19. The majority of these patients may not require empirical antibacterial treatment.

Descriptive Analysis of Pharmacy Students' Impressions on Virtual Interactive Case Software

Objective. To assess students' impressions on whether Virtual Interactive Cases (VICs) contribute to their learning experience. Methods. Ten fourth- year pharmacy students each independently completed the same four VICs followed by a semi-structured interview conducted by VIC project team members. The interviews were audio-recorded, transcribed, and coded for themes using qualitative research methods. Results. All participating students completed all the cases. Overall, students' feedback on VIC was positive. Five main themes emerged from the transcripts: VIC facilitated their skills in information gathering; they learned from the built-in, real-time, formative feedback; they had a fun and positive learning experience; VICs were realistic; and VIC system was user-friendly. Students also recommended that VIC be incorporated into classroom learning. Some students required additional explanation on the concept of time and costs associated with each action they selected, and the associated performance score. Conclusion. Pharmacy students' positive experiences with VICs support its use to bridge classroom learning with clinical practice.

Abstract 330: Targeted Nanotherapy for the Treatment of Atherosclerosis

Objective: Atherosclerosis is the leading cause of death and disability in the United States. We hypothesize that systemic administration of a novel nanofiber will target areas of atherosclerosis and regress atherosclerotic lesions.

Methods: Self assembling peptide amphiphile (PA) nanofibers were synthesized. An 18 amino acid sequence which retains the cholesterol efflux actions of apolipoprotein-A1 (apoA1) along with a Liver X Receptor (LXR) agonist, known to enhance cholesterol efflux, were incorporated into the nanofiber to both target and treat atherosclerosis. To assess the ability of the nanofiber to target and treat atherosclerosis in vivo , LDL receptor knockout mouse (LDLR KO) mice were fed a high fat diet (HFD) for 14 weeks after which they received bi-weekly injections of the therapeutic or control for 8 weeks. Optimum dose, concentration, binding duration, and biodistribution was determined using fluorescent microscopy and pixel quantification. Treatment groups included: PBS control, PA nanofiber with a scrambled targeting sequence, LXR agonist alone, targeted PA nanofiber (ApoA PA), and targeted PA nanofiber incorporating LXR agonist (ApoA-LXR PA). n=10/treatment group.

Results: ApoA PA and ApoA-LXR PA nanofibers effectively targeted atherosclerotic plaque in the aortic root. Optimum concentration of nanofiber was 2mg/mL, and optimum dose was 6mg/kg. There was no difference in optimum dosing or concentration between males and female mice. ApoA PA nanofiber localized to the aortic root for approximately 2-3 days, and was cleared from the aortic root by 7-10 days. Concentrations of ApoA PA in the aortic root was 5-fold higher than in the lung, liver, and kidney one day post injection. After only 8 weeks of treatment, male and female mice treated with ApoA-LXR PA had 11 and 9% plaque area reduction compared to PBS treated controls, respectively. Differences in treatment conditions vs. controls showed sex dependence, with only male mice demonstrating significantly higher plaque reduction from ApoA1-LXR PA treatment in comparison to scrambled PA treatment.

Conclusions: Our results demonstrate that a novel targeted nanofiber binds specifically to atherosclerotic lesions and reduce plaque burden after a short treatment duration.

Effect of an antimicrobial stewardship programme on antimicrobial utilisation and costs in patients with leukaemia: a retrospective controlled study

OBJECTIVES

To examine the effectiveness of an antimicrobial stewardship programme on utilization and cost of antimicrobials in leukaemia patients in Canada.

METHODS

We conducted a multisite retrospective observational time series study from 2005 to 2013. We implemented academic detailing as the intervention of an antimicrobial stewardship programme in leukaemia units at a hospital, piloted February-July 2010, then fully implemented December 2010-March 2013, with no intervention in August-November 2010. Internal control was the same hospital's allogeneic haematopoietic stem-cell transplantation unit. External control was the combined leukaemia-haematopoietic stem-cell transplantation unit at another hospital. Primary outcome was antimicrobial utilization (antibiotics and antifungals) in defined daily dose per 100 patient-days (PD). Secondary outcomes were antimicrobial cost (Canadian dollars per PD); cost and utilization by drug class; length of stay; 30-day inpatient mortality; and nosocomial Clostridium difficile infection. We used autoregressive integrated moving average models to evaluate the impact of the intervention on outcomes.

RESULTS

The intervention group included 1006 patients before implementation and 335 during full implementation. Correspondingly, internal control had 723 and 264 patients, external control 1395 and 864 patients. Antimicrobial utilization decreased significantly in the intervention group (p <0.01, 278 vs. 247 defined daily dose per 100 PD), increased in external control (p = 0.02, 237.4 vs. 268.9 defined daily dose per 100 PD) and remained stable in internal control (p = 0.66). Antimicrobial cost decreased in the intervention group (p = 0.03; $154.59 per PD vs. $128.93 per PD), increased in external control (p = 0.01; $109.4 per PD vs. $135.97 per PD) but was stable in internal control (p = 0.27). Mortality, length of stay and nosocomial C. difficile rate in intervention group remained stable.

CONCLUSIONS

The antimicrobial stewardship programme reduced antimicrobial use in leukaemia patients without affecting inpatient mortality and length of stay.

The Pharmacist’s Guide to Antimicrobial Therapy and Stewardship

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Activation of Nesfatin-1-Containing Neurones in the Hypothalamus and Brainstem by Peripheral Administration of Anorectic Hormones and Suppression of Feeding via Central Nesfatin-1 in Rats

Peripheral anorectic hormones, such as glucagon-like peptide (GLP)-1, cholecystokinin (CCK)-8 and leptin, suppress food intake. The newly-identified anorectic neuropeptide, nesfatin-1, is synthesised in both peripheral tissues and the central nervous system, particularly by various nuclei in the hypothalamus and brainstem. In the present study, we examined the effects of i.p. administration of GLP-1 and CCK-8 and co-administrations of GLP-1 and leptin at subthreshold doses as confirmed by measurement of food intake, on nesfatin-1-immunoreactive (-IR) neurones in the hypothalamus and brainstem of rats by Fos immunohistochemistry. Intraperitoneal administration of GLP-1 (100 μg/kg) caused significant increases in the number of nesfatin-1-IR neurones expressing Fos-immunoreactivity in the supraoptic nucleus (SON), the area postrema (AP) and the nucleus tractus solitarii (NTS) but not in the paraventricular nucleus (PVN), the arcuate nucleus (ARC) or the lateral hypothalamic area (LHA). On the other hand, i.p. administration of CCK-8 (50 μg/kg) resulted in marked increases in the number of nesfatin-1-IR neurones expressing Fos-immunoreactivity in the SON, PVN, AP and NTS but not in the ARC or LHA. No differences in the percentage of nesfatin-1-IR neurones expressing Fos-immunoreactivity in the nuclei of the hypothalamus and brainstem were observed between rats treated with saline, GLP-1 (33 μg/kg) or leptin. However, co-administration of GLP-1 (33 μg/kg) and leptin resulted in significant increases in the number of nesfatin-1-IR neurones expressing Fos-immunoreactivity in the AP and the NTS. Furthermore, decreased food intake induced by GLP-1, CCK-8 and leptin was attenuated significantly by pretreatment with i.c.v. administration of antisense nesfatin-1. These results indicate that nesfatin-1-expressing neurones in the brainstem may play an important role in sensing peripheral levels of GLP-1 and leptin in addition to CCK-8, and also suppress food intake in rats.

Solid organ transplant patients: are there opportunities for antimicrobial stewardship?

OBJECTIVE

Rising incidence of Clostridium difficile and multidrug-resistant organisms' infections and a dwindling development of new antimicrobials are an impetus for antimicrobial stewardship in organ transplant recipients. We sought to understand antimicrobial prescribing practices and identify opportunities for interdisciplinary collaboration among the transplant, antimicrobial stewardship, and infectious diseases teams.

METHODS

In 2013, two assessors conducted four real-time audits on all antimicrobial therapy in transplant patients, assessing each regimen against stewardship principles established by the Centers for Disease Prevention and Control, supplemented by applicable transplant-specific infection guidelines. Chi-square test was used to compare stewardship-concordant and stewardship-discordant audit results relative to transplant infectious diseases consultation.

RESULTS

Analysis was performed on 176 audits. Fifty-eight percent (103/176) received at least one antimicrobial, of which 69.9% (72/103) were stewardship-concordant. Infections were confirmed or suspected in 52.3% (92/176). Of those, 98.9% (91/92) received antimicrobials, and 41.8% (38/91) were prescribed by transplant clinicians. Infectious diseases consultation was associated with more stewardship-concordant prescriptions (78.5% vs. 59.6%, p = 0.03). The most common stewardship-discordant categories were lack of de-escalation, empiric antimicrobial spectrum being too broad, and therapy duration being too long.

CONCLUSIONS

Opportunities exist for antimicrobial stewardship in transplant recipients, especially those who do not require infectious diseases consultation.

Efficacy of an enteral feeding protocol for providing nutritional support after paediatric cardiac surgery

Enteral nutrition (EN) is considered to be a more appropriate method than parenteral feeding for providing nutrition to critically ill children. However, children who undergo cardiac surgery are at high risk of postoperative gastrointestinal complications during EN. The purpose of this study was to demonstrate the safety and efficacy of our EN feeding protocol after paediatric cardiac surgery through comparison between a single-centre prospective case series and historical cases. Forty-seven children who were admitted to the ICU after cardiac surgery were enrolled ('post group'). Data for these children were compared with a similar cohort of children who were admitted before the implementation of the feeding protocol (n=62; 'pre group'). The incidence of complications including vomiting, necrotising enterocolitis and hypoglycaemia; the time until the initiation of EN; and the changes in calories provided were compared between the groups. The frequency of vomiting was significantly lower in the post group than in the pre group (36.2% versus 58.0%, P=0.038), and necrotising enterocolitis did not occur in either group. The time until the initiation of EN and the total calories provided did not differ significantly; however, in the post group the proportion of energy provided by parenteral nutrition was significantly smaller (P <0.001), and provided by EN was significantly larger (P=0.003), than in the pre group. The frequency of hypoglycaemia was similar in both groups. This study showed that our EN protocol resulted in adjustments to calories provided via EN versus parenteral nutrition after paediatric cardiac surgery, and reduced the frequency of vomiting.

Safety and efficacy of once-daily modified-release tacrolimus in kidney transplant recipients: interim analysis of multicenter postmarketing surveillance in Japan

INTRODUCTION

Modified-release formulation of tacrolimus (TAC-MR) has been developed with the intent of improving patient adherence and quality of life. A number of studies have indicated that the efficacy and safety of once-daily TAC-MR were comparable with those of the original formulation, twice-daily TAC. However, its dosage, trough level, safety, and efficacy in the multicenter clinical experience of Japanese kidney transplant recipients have not been reported.

METHODS

This post-marketing surveillance designed as an open-label, prospective, noncomparative, noninterventional observational study was performed. The 256 patients were enrolled for de novo transplantation, and the 106 patients were enrolled for conversion to TAC-MR from 52 medical institutions in Japan. The follow-up period in de novo transplantation was 5 years, but here we report the results of the 24-week interim analysis. The observation period in conversion was 24 weeks.

RESULTS

Regarding de novo transplantation, the median daily TAC-MR dose was 0.150 mg/kg/d at the initial administration and the median TAC trough level was 12.1 ng/mL at 3 days. The common adverse drug reactions were infections, renal disorders, and glucose tolerance disorders at incidence rates of 23.6%, 6.8%, and 5.6%, respectively. Both patient and graft survival rates at 24 weeks were 98.2% and the rejection rate was 16.1%. Regarding conversion to TAC-MR, the median conventional TAC dose before conversion was 3.2 mg/d, and the median TAC-MR dose at the converted day was 3.2 mg/d. The median TAC trough level was 5.4 ng/mL before conversion, and it was 5.2 ng/mL after conversion. The most common adverse drug reactions were infections at an incidence rate of 4.9%. There was 1 graft loss and death, and there was 1 episode of rejection.

CONCLUSION

This interim analysis shows that a TAC-MR-based immunosuppressive regimen is safe and effective as used in Japanese clinical practice.

Modelling clogging and biofilm detachment in sponge carrier media

Sponge carrier media provide a large surface area for biofilm support; however, little information is known about how to model their dual nature as a moving bed and as porous media. To investigate the interaction of mass transfer and detachment with bio-clogging, a novel biofilm model framework was built based on individual-based modelling, and hydrodynamics were modelled using the lattice Boltzmann method. The combined model structure enabled the simulation of oxygen and biomass distribution inside the porous network as well as inside the biofilm. In order to apply the model to moving bed biofilm reactors (MBBR), biofilm detachment due to abrasion (carrier collisions) was modelled to be dependent on intracarrier distance. In the initial growth stage, biofilm grew homogeneously on the internal skeleton after which a more discontinuous growth developed which significantly increased permeability. Low detachment rates caused clogging in the outer pores which limited growth of biofilm to the surface region of the sponge. High detachment rates on the surface enabled deeper oxygen penetration with higher internal biomass activity. The degree of clogging was also sensitive to the presence of extracellular polymeric substances because of its large spatial occupancy.

Towards the Total Synthesis of Marineosin A: Construction of the Macrocyclic Pyrrole and an Advanced, Functionalized Spiroaminal Model

Herein, we describe the enantioselective construction of the 12-membered macrocyclic pyrrole core 4 of marineosin A in 5.1% overall yield from (S)-propylene oxide. The route features a key Stetter reaction to install a 1,4-diketone, which is then subjected to Paal-Knorr pyrrole synthesis and ring closing metathesis (RCM) to afford macrocycle 4. A divergence point in the synthetic scheme also enabled access to a highly functionalized spiroaminal model system 8 via an acid-mediated hydroxyketoamide cyclization strategy.