The use of new and better antibiotics for bacterial infections in patients with leukemia

A phytotherapic blend immunity-6™ inhibits myeloid leukemic cells 2 activation involving purinergic signaling

Leukemia is among the most common types of hematological cancers and the use of herbal medicines to prevent and treat leukemia are under quick development. Among several molecular pathways involved in leukemia pathogenesis and exacerbations, purinergic signaling is revealed as a key component. In the present study, the effects of two doses (5 ug/mL and 10 ug/mL) of Immunity-6™, a phytocomplex composed by beta-glucan, green tea (Camelia sinensis), chamomile (Matricaria chamomilla), and ascorbic acid (vitamin C) was tested in vitro, using chronic myelogenous leukemia cell line (K-562; 5 ×104/mL/well), which were challenged with lipopolysaccharide (LPS; 1 ug/mL) for 24 h. The results demonstrated that both doses of Immunity-6™ inhibited ATP release (p < 0.001) and P2×7 receptor at mRNA levels expression (p < 0.001). Purinergic inhibition by Immunity-6™ was followed by reduced release of proinflammatory cytokines IL-1beta (p < 0.001) and IL-6 (p < 0.001), while only 5 ug/mL of Immunity-6™ reduced the release of TNF-alpha (p < 0.001). Beyond to inhibit the release of pro-inflammatory cytokines, both doses of Immunity-6™ induced the release of anti-inflammatory cytokine IL-10 (p < 0.001), while only the higher dose (10 ug/mL) of Immunity-6™ induced the release of anti-inflammatory IL-1ra (p < 0.05) and klotho (p < 0.001). Thus, Immunity-6™ may be a promising adjuvant in the treatment of leukemia and further clinical trials are guaranteed.

Granulocyte collection by polymorphonuclear cell-targeting apheresis with medium-molecular-weight hydroxyethyl starch

Granulocyte transfusion (GTX) is a therapeutic option for patients with prolonged neutropenia suffering from severe infections. Efficient granulocyte collection by apheresis from donors requires clear separation of granulocytes from red blood cells (RBCs), and infusion of high-molecular-weight (MW) hydroxyethyl starch (HES) facilitates RBC sedimentation. Recent research has shown that apheresis with medium-MW HES may prevent adverse effects of high-MW HES on donors, but the rationale for collection with medium-MW HES has yet to be evaluated. To validate the use of medium-MW HES, we first performed experiments with whole blood samples to determine how efficiently high-, medium- and low-MW HES separated granulocytes from RBCs, and found that medium-MW HES was just as efficient as high-MW HES. We also reviewed clinical data of granulocyte apheresis at our institution to evaluate granulocyte yields. Retrospective analysis of granulocyte collection revealed that apheresis with medium-MW HES yielded sufficient granulocytes for GTX and that donor anemia reduced collection efficiency. These results collectively may help us to establish a safer method for apheresis targeting polymorphonuclear granulocytes as an alternative to high-MW HES.

Insights into idarubicin antimicrobial activity against methicillin-resistant Staphylococcus aureus

BACKGROUND

MRSA is a major concern in community settings and in health care. The emergence of biofilms and persister cells substantially increases its antimicrobial resistance. It is very urgent to develop new antimicrobials to solve this problem.

OBJECTIVE

Idarubicin was profiled to assess its antimicrobial effects in vitro and in vivo, and the underlying mechanisms.

METHODS

We investigated the antimicrobial effects of idarubicin against MRSA by time-kill analysis. The antibiofilm efficacy of idarubicin was assessed by crystal violet and XTT staining, followed by laser confocal microscopy observation. The mechanisms underlying the antimicrobial effects were studied by transmission electron microscopy, all-atom molecular dynamic simulations, SYTOX staining, surface plasma resonance, and DNA gyrase inhibition assay. Further, we addressed the antimicrobial efficacy in wound and subcutaneous abscess infection in vivo.

RESULTS

Idarubicin kills MRSA cells by disrupting the lipid bilayers and interrupting the DNA topoisomerase IIA subunits, and idarubicin shows synergistic antimicrobial effects with fosfomycin. Through synergy with a single dose treatment fosfomycin and the addition of the cell protector amifostine, the cytotoxicity and cardiotoxicity of idarubicin were significantly reduced without affecting its antimicrobial effects. Idarubicin alone or in combination with fosfomycin exhibited considerable efficacy in a subcutaneous abscess mouse model of MRSA infection. In addition, idarubicin also showed a low probability of causing resistance and good postantibiotic effects.

CONCLUSIONS

Idarubicin and its analogs have the potential to become a new class of antimicrobials for the treatment of MRSA-related infections.

Antimicrobial stewardship in patients with cancer

Consensus guidelines recommend antimicrobial stewardship in all hospitals with the following goals in mind: appropriate and judicious use of antimicrobial agents leading to increased drug safety, reduced antimicrobial utilization, reduction in the development and selection of resistant organisms, cost containment, and improved patient outcomes. Patients with cancer, especially those with hematologic malignancies and neutropenia, develop serious infections often and receive antimicrobial therapy frequently. Consequently, there is considerable opportunity to practice antimicrobial stewardship in this population. Several antimicrobial stewardship strategies such as antimicrobial restriction, cycling, prospective audit and feedback, and de-escalation have been evaluated in patients with cancer. The primary focus has been on the prevention and treatment of bacterial infections in febrile neutropenic patients. These efforts should be expanded to include fungal, viral, and other infections.

Prospective audit and feedback on antibiotic prescription in an adult hematology-oncology unit in Singapore

We evaluated the impact of a prospective audit and feedback antimicrobial stewardship program (ASP) on antibiotic prescription and resistance trends in a hematology-oncology unit in a university hospital (National University Cancer Institute, Singapore [NCIS]). A prospective interrupted time-series study comprising 11-month pre-intervention (PIP) and intervention evaluation phases (IEP) flanking a one-month implementation phase was carried out. Outcome measures included defined daily dose per 100 (DDD/100) inpatient-days of ASP-audited and all antibiotics (encompassing audited and non-audited antibiotics), and the incidence-density of antibiotic-resistant microorganisms at the NCIS. Internal and external controls were DDD/100 inpatient-days of paracetamol at the NCIS and DDD/100 inpatient-days of antibiotics prescribed in the rest of the hospital. There were 580 ASP recommendations from 1,276 audits, with a mean monthly compliance of 86.9%. Significant reversal of prescription trends towards reduced prescription of audited (coefficient = -2.621; 95% confidence interval [CI]: -4.923, -0.319; p = 0.026) and all evaluated antibiotics (coefficient = -4.069; 95% CI: -8.075, -0.063; p = 0.046) was observed. No changes were seen for both internal and external controls, except for the reversal of prescription trends for cephalosporins hospital-wide. Antimicrobial resistance did not change over the time period of the study. Adverse outcomes-the majority unavoidable-occurred following 5.5% of accepted ASP recommendations. Safe and effective ASPs can be implemented in the complex setting of hematology-oncology inpatients.