In vivo pharmacodynamic characterization of a next-generation polyene, SF001, in the invasive pulmonary aspergillosis mouse model

SF001 is a next-generation polyene antifungal drug in development, designed to have increased specificity to fungal ergosterol, which is absent in humans, and decreased binding to cholesterol. SF001 demonstrates long-acting, potent, broad-spectrum fungicidal activity. The goal of the current study was to determine the pharmacodynamic index and target of SF001 in an immunocompromised mouse model of invasive pulmonary aspergillosis against six Aspergillus fumigatus isolates. Minimum inhibitory concentration (MIC) values ranged from 0.5 to 2.0 mg/L. Plasma and epithelial lining fluid (ELF) pharmacokinetics were performed following single intraperitoneal doses of 1, 4, 16, and 64 mg/kg. Treatment efficacy was assessed with each of the six fungal isolates using daily doses of SF001 ranging from 0.25 to 64 mg/kg/day over a 96-h treatment duration. Efficacy was assessed by A. fumigatus quantitative PCR of conidial equivalents from lung homogenates. Nonlinear regression analysis using the Hill equation demonstrated that the 24-h exposure-response relationships for both plasma and ELF area under the concentration/MIC and Cmax/MIC ratios were strong and relatively similar [coefficient of determination (R2) = 0.74-0.75). Exposure-response relationships included a median plasma 24-h Cmax/MIC target for stasis and 1-log kill endpoint of 0.5 and 0.6, respectively. The present studies demonstrated in vitro and in vivo SF001 potency against A. fumigatus. These results have potential relevance for SF001 clinical dose selection and evaluation of susceptibility breakpoints.

Cryptococcosis and Cryptococcal Meningitis: A Narrative Review and the Up-to-Date Management Approach

Cryptococcosis is a fungal infectious disease that enormously impacts human health worldwide. Cryptococcal meningitis is the most severe disease caused by the fungus Cryptococcus, and can lead to death, if left untreated. Many patients develop resistance and progress to death even after treatment. It requires a prolonged treatment course in people with AIDS. This narrative review provides an evidence-based summary of the current treatment modalities and future trial options, including newer ones, namely, 18B7, T-2307, VT-1598, AR12, manogepix, and miltefosine. This review also evaluated the management and empiric treatment of cryptococcus meningitis. The disease can easily evade diagnosis with subacute presentation. Despite the severity of the disease, treatment options for cryptococcosis remain limited, and more research is needed.

High-dose amphotericin: yay or nay? A case series and literature review

Invasive fungal infections pose significant morbidity and mortality risks, particularly those caused by moulds. Available antifungal classes are limited by toxicities and are increasingly susceptible to resistance, particularly amongst challenging fungal pathogens. The purpose of this case series and literature review was to characterize the use of a high-dose lipid formulation of amphotericin B. A case series is presented including patients who received high-dose lipid formulation amphotericin B (≥7.5 mg/kg/day) between June 2012 and August 2021. Additionally, a systematic literature review was conducted by searching the PubMed database for English-language studies involving individuals who received high-dose amphotericin B therapy (≥7.5 mg/kg) using lipid formulations. Nine patients were included in the case series, receiving an average of 8.9 ± 1.3 mg/kg liposomal amphotericin B over a mean of 11.0 ± 10.8 days predominantly for mould infections including Mucorales, aspergillosis and Fusarium. The patients were primarily cared for in intensive care units, with varying treatment histories and outcomes. A total of 11 studies (n=260 patients) met inclusion criteria for the literature review. Responses to high-dose liposomal amphotericin B ranged from 8% to 100%, often showing favourable outcomes. High doses of liposomal amphotericin B were well tolerated both in the case series and in published literature, with serum creatinine changes being the most commonly reported adverse event. However, multi-patient studies continue to report less than favourable (range 8-62%) response rates. High-dose liposomal amphotericin B, either alone or in combination with other antifungal agents, might be a viable strategy for managing invasive fungal infections when few treatment choices exist. This article is part of the Challenges and strategies in the management of invasive fungal infections Special Issue: https://www.drugsincontext.com/special_issues/challenges-and-strategies-in-the-management-of-invasive-fungal-infections.

Hospital‑acquired pneumonia caused by Kodamaea ohmeri during extracorporeal membrane oxygenation treatment: A case report and literature review

Kodamaea ohmeri (K. ohmeri) is an ascosporogenic species of yeast that belongs to the genus Ascosporogenous and the family of Saccharomycetaceae. It has recently been found to cause various types of infections, particularly in critically ill immunocompromised patients. The present study describes a case of hospital-acquired pneumonia caused by K. ohmeri during veno-arterial extracorporeal membrane oxygenation. The fungal culture turned negative after the administration of caspofungin and amphotericin B. Extracorporeal membrane oxygenation (ECMO) is an adjunctive medical technique that provides temporary cardiopulmonary support for patients. Previous observations have suggested that the immune function of patients will typically decline during the use of ECMO, rendering infection to be one of the main complications of ECMO. K. ohmeri is a rare pathogenic fungus, particularly in immunocompromised individuals with vascular catheters, while amphotericin B is the most common antifungal therapy administered to treat K. ohmeri infections. It is important to raise awareness of rare fungal infections and actively treat them.

Diagnosis and management of cryptococcal meningitis in HIV-infected adults

Cryptococcal meningitis is a leading cause of morbidity and mortality globally, especially in people with advanced HIV disease. Cryptococcal meningitis is responsible for nearly 20% of all deaths related to advanced HIV disease, with the burden of disease predominantly experienced by people in resource-limited countries. Major advancements in diagnostics have introduced low-cost, easy-to-use antigen tests with remarkably high sensitivity and specificity. These tests have led to improved diagnostic accuracy and are essential for screening campaigns to reduce the burden of cryptococcosis. In the last 5 years, several high-quality, multisite clinical trials have led to innovations in therapeutics that have allowed for simplified regimens, which are better tolerated and result in less intensive monitoring and management of medication adverse effects. One trial found that a shorter, 7-day course of deoxycholate amphotericin B is as effective as the longer 14-day course and that flucytosine is an essential partner drug for reducing mortality in the acute phase of disease. Single-dose liposomal amphotericin B has also been found to be as effective as a 7-day course of deoxycholate amphotericin B. These findings have allowed for simpler and safer treatment regimens that also reduce the burden on the healthcare system. This review provides a detailed discussion of the latest evidence guiding the clinical management and special circumstances that make cryptococcal meningitis uniquely difficult to treat.

Rhinocerebral Mucormycosis with Extensive Cranial Nerve Palsies in a Diabetic Patient

Mucormycosis is a common opportunistic fungal infection with a disseminated nature. Despite being a devastating disease with the involvement of multiple upper cranial nerves, the implications of the seventh cranial nerve have been infrequently encountered. Although the radiological evidence with sinus destruction supports the diagnosis, histological specimen showing fungal elements confirms it as fungal culture doesn't always demonstrate a high diagnostic yield. Early detection and multimodal treatment are mandatory to prevent detrimental outcomes and to control the disease progression. We, hereby present a rare case of rhinocerebral mucormycosis with multiple cranial nerve involvement including the facial nerve in a 70-year-old female with long-standing poorly controlled diabetes mellitus.

A unique case of Rhizopus oryzae brain abscess treated with intracavitary amphotericin

Here we present a case of a poorly controlled diabetic who developed extensive rhinocerebral mucormycosis. Systemic and intrathecal amphotericin were not able to improve his life threatening infection. Therefore, salvage therapy with intracavitary amphotericin B deoxycholate was used to instill antifungal therapy directly into the patient's brain abscess. For proper dosing of intracavitary amphotericin B deoxycholate, we devised a formula which can be theoretically applied for all intracavitary therapies. Unfortunately, the patient's family withdrew care 6 days after starting intracavitary amphotericin and efficacy of this therapy could not be evaluated.

Cryptococcal Meningitis in an HIV-Negative Pulmonary Tuberculosis Patient: A Case Report

Cryptococcal meningitis represents a severe opportunistic fungal infection primarily observed in individuals with compromised immune systems. It frequently manifests in symptoms like headaches, vomiting, cranial nerve complications, and cognitive alterations. However, it's worth noting that up to 15% of cases may exhibit no discernible central nervous system-related symptoms. A 70-year-old male, previously diagnosed with pulmonary tuberculosis and undergoing treatment with anti-tubercular medications, was admitted due to changes in consciousness, sporadic low-grade fever, and cognitive impairment. An in-depth investigation revealed his HIV-negative and non-diabetic status, as well as his preserved immune competence. A plain CT head showed a communicating hydrocephalus and a lumbar puncture was positive for Cryptococcus neoformans. Treatment commenced with an induction regimen encompassing amphotericin and fluconazole, concurrently maintaining the anti-tubercular treatment course. The patient's condition displayed improvement, leading to a transition to a maintenance dosage of fluconazole. This case highlighted an extraordinary occurrence of Cryptococcal meningitis in an HIV-negative patient with no history of immunosuppressant use. Notably, Cryptococcal infection should be regarded as a primary consideration in patients afflicted by pulmonary tuberculosis who subsequently present with altered consciousness. The timely identification and proper management of such instances can substantially mitigate the risks of mortality and morbidity associated with this condition.

Post-Covid Isolated Mandibular Mucormycosis in a Patient with Chronic Kidney Disease: A Case Report

Mucormycosis is an opportunistic fungal infection which was earlier seen only in immunocompromised patients. With the recent covid pandemic, there had been a drastic surge in cases of mucormycosis worldwide and especially in India. Here, we present an unusual case of biopsy proven invasive mandibular mucormycosis in a patient with chronic kidney disease and a history of COVID-19 infection. The patient was given low-dose amphotericin B and underwent surgical debridement with a successful outcome.

Evolution of antifungals for invasive mold infections in immunocompromised hosts, then and now

INTRODUCTION

The current armamentarium of antifungal agents for invasive mold infections (IMI) has dramatically improved over the last 50 years. Existing therapies are, however, associated with toxicities, drug interactions, and in some cases, therapeutic failures. Novel antifungals are needed to address the increasing prevalence of IMI and the growing threat of antifungal resistance.

AREAS COVERED

We review the history and development of the most commonly used antifungals. We discuss the current consensus guidelines and supporting data for treatment of invasive mold infection (IMI), the role of susceptibility testing, and the niche that novel antifungals could fill. We review the current data for aspergillosis, mucormycosis, and hyalohyphomycosis.

EXPERT OPINION

Robust clinical trial data demonstrating the relative effectiveness of our current antifungal agents for treating IMI outside of A. fumigatus remains limited. Clinical trials are urgently needed to delineate the relationship between MICs and clinical outcomes for existing agents and to better evaluate the invitro and in-vivo aspects of antifungal synergy. Continued international multicenter collaboration and standardized clinical endpoints for trials evaluating both existing and new agents is necessary to advance the field.

Severe Fungal Asthma: A Role for Biologics and Inhaled Antifungals

Allergic asthma has traditionally been treated with inhaled and systemic glucocorticosteroids. A continuum of allergic fungal airways disease associated with Aspergillus fumigatus colonization and/or atopic immune responses that encompasses fungal asthma, severe asthma with fungal sensitization and allergic bronchopulmonary aspergillosis is now recognized along a phenotypic severity spectrum of T2-high immune deviation lung disease. Oral triazoles have shown clinical, anti-inflammatory and microbiologic efficacy in this setting; in the future inhaled antifungals may improve the therapeutic index. Humanized monoclonal antibody biologic agents targeting T2-high disease also show efficacy and promise of improved control in difficult cases. Developments in these areas are highlighted in this overview.

DRESS Syndrome Associated with Liposomal Amphotericin-B in a Kidney Transplant Patient: A Case Report

INTRODUCTION

Liposomal amphotericin B is a widely used broad-spectrum antifungal drug. It was developed to reduce nephrotoxicity and maximize the therapeutic utility of amphotericin B in the treatment of invasive fungal infections. Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) syndrome is a severe drug-induced hypersensitivity syndrome commonly associated with aromatic antiepileptic drugs. Liposomal amphotericin-B was associated with DRESS syndrome in only one case.

CASE REPORT

We report an exceptional case of possible DRESS syndrome associated with liposomal amphotericin B in a 31-year-old male renal transplant recipient. Seventeen days after starting liposomal amphotericin B for visceral leishmaniosis, he developed a skin rash with elevated liver tests. Liposomal amphotericin B was then discontinued. A favourable outcome was slowly observed in one month.

RESULTS AND CONCLUSION

This case scored two (possible case) based on the criteria adopted by the European group RegiSCAR. The Naranjo score for liposomal amphotericin B was four (possible).

Cost-effectiveness of single, high-dose, liposomal amphotericin regimen for HIV-associated cryptococcal meningitis in five countries in sub-Saharan Africa: an economic analysis of the AMBITION-cm trial

BACKGROUND

HIV-associated cryptococcal meningitis is a leading cause of AIDS-related mortality. The AMBITION-cm trial showed that a regimen based on a single high dose of liposomal amphotericin B deoxycholate (AmBisome group) was non-inferior to the WHO-recommended treatment of seven daily doses of amphotericin B deoxycholate (control group) and was associated with fewer adverse events. We present a five-country cost-effectiveness analysis.

METHODS

The AMBITION-cm trial enrolled patients with HIV-associated cryptococcal meningitis from eight hospitals in Botswana, Malawi, South Africa, Uganda, and Zimbabwe. Taking a health service perspective, we collected country-specific unit costs and individual resource-use data per participant over the 10-week trial period, calculating mean cost per participant by group, mean cost-difference between groups, and incremental cost-effectiveness ratio per life-year saved. Non-parametric bootstrapping and scenarios analyses were performed including hypothetical real-world resource use. The trial registration number is ISRCTN72509687, and the trial has been completed.

FINDINGS

The AMBITION-cm trial enrolled 844 participants, and 814 were included in the intention-to-treat analysis (327 from Uganda, 225 from Malawi, 107 from South Africa, 84 from Botswana, and 71 from Zimbabwe) with 407 in each group, between Jan 31, 2018, and Feb 17, 2021. Using Malawi as a representative example, mean total costs per participant were US$1369 (95% CI 1314-1424) in the AmBisome group and $1237 (1181-1293) in the control group. The incremental cost-effectiveness ratio was $128 (59-257) per life-year saved. Excluding study protocol-driven cost, using a real-world toxicity monitoring schedule, the cost per life-year saved reduced to $80 (15-275). Changes in the duration of the hospital stay and antifungal medication cost showed the greatest effect in sensitivity analyses. Results were similar across countries, with the cost per life-year saved in the real-world scenario ranging from $71 in Botswana to $121 in Uganda.

INTERPRETATION

The AmBisome regimen was cost-effective at a low incremental cost-effectiveness ratio. The regimen might be even less costly and potentially cost-saving in real-world implementation given the lower drug-related toxicity and the potential for shorter hospital stays.

FUNDING

European Developing Countries Clinical Trials Partnership, Swedish International Development Cooperation Agency, Wellcome Trust and Medical Research Council, UKAID Joint Global Health Trials, and the National Institute for Health Research.

TRANSLATIONS

For the Chichewa, Isixhosa, Luganda, Setswana and Shona translations of the abstract see Supplementary Materials section.

Bilateral renal mucormycosis following COVID-19 infection: A therapeutic challenge

India witnessed an epidemic of mucormycosis during the second wave of the COVID-19 pandemic. Renal mucormycosis has been reported rarely, mostly from India, but only 2 cases have been reported following COVID-19 infection to date. We report a case of mucormycosis predominantly affecting kidneys in a young and previously healthy male following COVID-19 pneumonia, for which he had received corticosteroid, remdesivir, and tocilizumab. He presented with hematuria, progressive oliguria, and severe acute kidney injury (AKI) requiring dialysis. The diagnosis was made on kidney biopsy and contrast-enhanced CT (CECT) showed segmental and subsegmental renal artery pseudoaneurysms with distal occlusion of both kidneys. He underwent bilateral nephrectomy and received high-dose amphotericin (AMB) and posaconazole. He developed cardiac arrhythmia and pulmonary edema attributed to AMB-related cardiotoxicity after a cumulative ABM dose of 2,450 mg. This is the first case report describing the survival of a patient with bilateral renal mucormycosis following COVID-19 infection. Our case report highlights the importance of considering mucormycosis in a patient with post-COVID-19 AKI to make an early diagnosis and aggressive management comprising of surgical debridement and high-dose AMB to improve survival.

Emergence of Cerebral Mucormycosis in the Post-COVID Period: A Detailed Analysis of Risk Factors, Clinical Progression, and Management of This Opportunistic Fungal Infection

BACKGROUND

An epidemic of Mucorales was reported following the second wave of COVID-19 in India, and intracranial extension of the same was one of the most dreadful complications.

METHODS

A total of 62 patients with cerebral mucormycosis were recruited and followed up till 12 weeks to evaluate the risk factors, incidence, clinical manifestations, management, and prognosis of cerebral mucormycosis.

FINDINGS

A median age of 51.5 years with male predominance (74%) was noted. The majority of subjects reported a history of COVID infection (93.5%) and diabetes mellitus (83.87%). The first symptom of mucormycosis appeared after a mean period of 17.63 ± 8.9 days following COVID. Facial swelling and ptosis were the most common symptoms. Only 55% of patients had neurological presentations, and hemiparesis was the most common neurological sign (30.6%). Radiologically, the involvement of maxillary sinus (90.32%) and ethmoid sinus (87.10%) was commonly noted. Cerebral findings included temporal lobe (50%) and parietal lobe (30.06%) involvement, cavernous sinus thrombosis (30.06%), and internal carotid artery thrombosis (22.58%). Acute cerebral infarction was notable in 37% of subjects (p-value=0.0015, significant association with the outcome). Conventional and liposomal amphotericin B were used in 91.94% and 53.23% of patients, respectively. Retrobulbar amphotericin injections used in 11.3% of subjects significantly affected the outcome (p-value=0.03, significant). Posaconazole step-down therapy was used in 72.5% of subjects (p-value=0.0005, significant). Surgical interventions were performed in 53 (85.48%) subjects (p-value=0.004, significant). Functional endoscopic sinus surgery was the most common (in 64.52% of subjects), followed by maxillectomy (20.97% of subjects) and craniotomy (17.7% of subjects). At the end of 12 weeks, 33.87% of patients died and 59.68% were alive; the rest (6.45%) were lost to follow-up.

INTERPRETATION

The absence or late presentation of neurological symptoms led to a delayed diagnosis of cerebral mucormycosis. The presence of acute cerebral infarction indicated a worse prognosis. However, there was a significant influence of step-down posaconazole therapy, retrobulbar amphotericin injections, and surgical intervention on the prognosis of cerebral mucormycosis.

Amphotericin B-PEG Conjugates of ZnO Nanoparticles: Enhancement Antifungal Activity with Minimal Toxicity

Amphotericin B (AMB) is commonly used to treat life-threatening systemic fungal infections. AMB formulations that are more efficient and less nephrotoxic are currently unmet needs. In the current study, new ZnO-PEGylated AMB (ZnO-AMB-PEG) nanoparticles (NPs) were synthesized and their antifungal effects on the Candida spp. were investigated. The size and zeta potential values of AMB-PEG and ZnO-AMB-PEG NPs were 216.2 ± 26.9 to 662.3 ± 24.7 nm and −11.8 ± 2.02 to −14.2 ± 0.94 mV, respectively. The FTIR, XRD, and EDX spectra indicated that the PEG-enclosed AMB was capped by ZnO, and SEM images revealed the ZnO distribution on the surface NPs. In comparison to ZnO-AMB NPs and free AMB against C.albicans and C.neoformans, ZnO-AMB-PEG NPs significantly reduced the MIC and MFC. After a week of single and multiple dosage, the toxicity was investigated utilizing in vitro blood hemolysis, in vivo nephrotoxicity, and hepatic functions. ZnO-AMB-PEG significantly lowered WBC count and hematocrit concentrations when compared to AMB and ZnO-AMB. RBC count and hemoglobulin content, on the other hand, were unaltered. ZnO-AMB-PEG considerably lowered creatinine and blood urea nitrogen (BUN) levels when compared to AMB and ZnO-AMB. The difference in liver function indicators was determined to be minor by all formulae. These findings imply that ZnO-AMB-PEG could be utilized in the clinic with little nephrotoxicity, although more research is needed to determine the formulation’s in vivo efficacy.

Primary amoebic meningoencephalitis in children- report of two cases from South India

Primary Amoebic meningoencephalitis is a rare and fatal neuro-infection caused by free-living fresh-water amoeba Naegleria fowleri. It is a ubiquitous organism and the infection occurs usually via contact with warm water-bodies. The clinical presentation is often indistinguishable from acute bacterial meningitis and the diagnosis can be made by CSF wet smear examination if there is a high index of suspicion. The disease progresses rapidly compared to pyogenic meningitis and usually has a fatal outcome. Reports of two confirmed cases of primary amoebic meningoencephalitis in children from different centres in Kerala state of India are presented here. In spite of early diagnosis and treatment, both these patients demised. Primary amoebic meningoencephalitis should be considered in the differential diagnosis of acute meningitis, especially in patients with recent freshwater exposure. Implementation of chlorination of pools of water bodies, especially if re-opened for recreational purpose after prolonged periods of non-use, needs vigorous implementation.

Management of Histoplasmosis by Infectious Disease Physicians

Background

The Infectious Diseases Society of America (IDSA) guidelines for the management of histoplasmosis were last revised 15 years ago. Since those guidelines were compiled, new antifungal treatment options have been developed. Furthermore, the ongoing development of immunomodulatory therapies has increased the population at increased risk to develop histoplasmosis.

Methods

An electronic survey about the management practices of histoplasmosis was distributed to the adult infectious disease (ID) physician members of the IDSA's Emerging Infections Network.

Results

The survey response rate was 37% (551/1477). Only 46% (253/551) of respondents reported seeing patients with histoplasmosis. Regions considered endemic had 82% (158/193) of physicians report seeing patients with histoplasmosis compared to 27% (95/358) of physicians in regions not classically considered endemic (P < 0.001). Most ID physicians follow IDSA treatment guidelines recommending itraconazole for acute pulmonary (189/253 [75%]), mild-moderate disseminated (189/253 [75%]), and as step-down therapy for severe disseminated histoplasmosis with (232/253 [92%]) and without (145/253 [57%]) central nervous system involvement. There were no consensus recommendations observed for survey questions regarding immunocompromised patients.

Conclusions

Though there are increased reports of histoplasmosis diagnoses outside regions classically considered endemic, a majority of ID physicians reported not seeing patients with histoplasmosis. Most respondents reported adherence to IDSA guidelines recommending itraconazole in each clinical situation. New histoplasmosis guidelines need to reflect the growing need for updated general guidance, particularly for immunocompromised populations.

Outcomes after lung resection in renal transplant patients with pulmonary mucormycosis

Pulmonary mucormycosis has been associated with high mortality (reported up to 100%) in renal transplant recipients. This was a retrospective analysis of renal transplant patients with pulmonary mucormycosis between April 2014 - March 2020, who underwent surgical resection of the affected lung along with liposomal amphotericin therapy. Patients with lower respiratory illness features underwent chest X-ray, high-resolution computed tomography of the chest, and those with suspicious findings underwent analysis of bronchioloalveolar fluid and transbronchial lung biopsy. Patients with histological or microbiological evidence of mucormycosis were started on liposomal Amphotericin B. Tacrolimus and mycophenolate mofetil were stopped at the time of diagnosis. Patients were taken up for surgical resection of the affected part of the lung. Ten patients underwent combined management, while five patients were managed medically. At last follow up, seven out of ten patients (70%) who underwent combined management and two of the five patients (40%) who were managed medically, had a mean survival of 28.86 months (sd = 15.71, median = 25) and 14.17 months (sd = 12.21, median = 18), respectively, post-diagnosis of pulmonary mucormycosis. Surgical resection combined with antifungals in the perioperative period and decreased immunosuppression may improve the outcomes in renal transplant patients with pulmonary mucormycosis. This article is protected by copyright. All rights reserved.

Attributable Mortality of Candida Bloodstream Infections in the Modern Era: A Propensity Score Analysis

BACKGROUND

This study quantifies the mortality attributable to Candida bloodstream infections (BSI) in the modern era of echinocandins.

DESIGN

We conducted a retrospective cohort study of adult patients admitted to Barnes Jewish Hospital, a 1,368-bed tertiary care academic hospital, in Saint Louis, Missouri from 1/2/2012-4/30/2019. We identified 626 adult patients with Candida BSI that were frequency-matched with 6,269 control patients that had similar Candida BSI risk-factors. The 90-day all-cause mortality attributable to Candida BSI was calculated using three methods-propensity score matching, matching by inverse weighting of propensity score, and stratified analysis by quintile.

RESULTS

The 90-day crude mortality was 42.4% (269 patients) for Candida BSI cases and 17.1% (1,083 patients) for frequency-matched controls. Following propensity score-matching, the attributable risk difference for 90-day mortality was 28.4% with hazard ratio (HR) of 2.12 (95% CI, 1.98-2.25, p<0.001). In the stratified analysis, the risk for mortality at 90 days was highest in patients in the lowest risk quintile to develop Candida BSI (HR 3.13 (95% CI, 2.33-4.19). Patients in this lowest risk quintile accounted for 81(61%) of the 130 untreated patients with Candida BSI. Sixty nine percent of untreated patients (57/83) died versus 35% of (49/127) of treated patients (p<0.001).

CONCLUSIONS

Patients with Candida BSI continue to experience high mortality. Mortality attributable to Candida BSI was more pronounced in patients at lowest risk to develop Candida BSI. A higher proportion of these low-risk patients went untreated, experienced higher mortality, and should be the target of aggressive interventions to ensure timely, effective treatment.

Coalition of Biological Agent (Melatonin) With Chemotherapeutic Agent (Amphotericin B) for Combating Visceral Leishmaniasis via Oral Administration of Modified Solid Lipid Nanoparticles

In this study, 2-hydroxypropyl-β-cyclodextrin (HPβCD) grafted solid lipid nanoparticle (SLN)-based bioconjugate was synthesized and used for administering a combination of melatonin (Mel) and amphotericin B (AmB) orally for effective visceral leishmaniasis (VL) treatment. The formulations (HPCD-Mel-AmB SLN) were synthesized by the emulsion solvent evaporation method. HPCD-Mel-AmB SLN showed a high loading capacity and a high entrapment efficiency of AmB (% DL = 9.0 ± 0.55 and % EE = 87.9 ± 0.57) and Mel (% DL = 7.5 ± 0.51 and % EE = 63 ± 6.24). The cumulative percent release of AmB and Mel was 66.10 and 73.06%, respectively, up to 72 h. Time-dependent cellular uptake was noticed for HPCD-Mel-AmB SLN for 4 h. Further, HPCD-Mel-AmB SLN did not show any toxic effects on J774A.1 macrophages and Swiss albino mice. HPCD-Mel-AmB SLN (10 mg/kg ×5 days, p.o.) has significantly diminished (98.89%) the intracellular parasite load in liver tissues of L. donovani-infected BALB/c mice, subsequently highlighting the role of melatonin toward an effective strategy in combating leishmanial infection. Therefore, these results indicated that administration of HPCD-Mel-AmB SLN improve the therapeutic index of the first-line drug in addition to the introduction of biological agent and would be a promising therapeutic candidate for effective VL therapy. In the present study, the objective is to test the efficacy of the chemotherapeutic approach in combination with a biological immunomodulatory agent against leishmanial infection using in vitro and in vivo studies. This information suggests that melatonin could be an efficacious and potent antileishmanial agent.

Efficacy and safety of pentamidine isethionate for tegumentary and visceral human leishmaniasis: a systematic review

RATIONALE FOR REVIEW

We performed a systematic review of the literature to investigate the efficacy and safety of pentamidine isethionate for the treatment of human tegumentary and visceral leishmaniasis.

KEY FINDINGS

A total of 616 papers were evaluated, and 88 studies reporting data on 3108 cases of leishmaniasis (2082 patients with tegumentary leishmaniasis and 1026 with visceral leishmaniasis) were finally included. The majority of available studies were on New World cutaneous leishmaniasis and visceral leishmaniasis caused by Leishmania donovani. At the same time, few data are available for Old World cutaneous leishmaniasis, mucosal leishmaniasis, and visceral leishmaniasis caused by L. infantum. Pooled cure rate for tegumentary leishmaniasis was 78.8% (CI 95%, 76.9-80.6%) and 92.7% (CI 95%, 88.3-97.1%) according to controlled randomized trial and observational studies and case report and case series respectively. Pooled cure rate for visceral leishmaniasis was 84.8% (CI 95%, 82.6-87.1%) and 90.7% (CI 95%, 84.1-97.3%) according to controlled randomized trial and observational studies and case report and case series, respectively. Comparable cure rate was observed in recurrent and refractory cases of visceral leishmaniasis. Concerning the safety profile, among about 2000 treated subjects with some available information, the most relevant side effects were six cases of arrhythmia (including four cases of fatal ventricular fibrillation), 20 cases of irreversible diabetes, 26 cases of muscular aseptic abscess following intramuscular administration.

CONCLUSIONS/RECOMMENDATIONS

Pentamidine isethionate is associated with a similar cure rate of the first-line anti-leishmanial drugs. Severe and irreversible adverse effect appear to be rare. The drug may still have a role in the treatment of any form of human leishmaniasis when the first-line option has failed or in patients who cannot tolerate other drugs also in the setting of travel medicine. In difficult cases, the drug can also be considered as a component of a combination treatment regimen.

Evaluation of Total Body Weight versus Adjusted Body Weight Liposomal Amphotericin B Dosing in Obese Patients

Liposomal amphotericin B (LAmB) is used for various fungal infections, but it is unclear which dosing weight to use in obese patients. The purpose of this study was to compare clinical outcomes of adjusted body weight (adjBW) versus total body weight (TBW) dosing of LAmB. This single-center, retrospective cohort study included patients who received LAmB for definitive therapy and whose TBW exceeded 120% of their ideal body weight (IBW). Analyses were conducted for 3 mg/kg for adjBW versus TBW and 5 mg/kg for adjBW versus TBW. A total of 238 patients were included. For the 68 patients who received LAmB at 3 mg/kg, there were no differences in safety or efficacy outcomes. For the 170 patients who received LAmB at 5 mg/kg, significantly more patients in the TBW group experienced the primary outcome of nephrotoxicity (57% versus 35% [P value of 0.016]) and had significantly higher rates of early discontinuation of LAmB due to toxicity (33% versus 17% [P = 0.030]). There was a trend toward increased 90-day mortality in the adjBW group (60% versus 45% [P = 0.079]); however, adjBW dosing was not associated with increased mortality in an adjusted model. Given the lower rates of nephrotoxicity but a possible trend toward increased mortality in patients whose TBW exceeds 120% of their IBW, dosing LAmB by adjBW may be reasonable in patients who are not critically ill and who have lower-risk infections. In critically ill patients or those with fungal pathogens or sites of infection associated with higher mortality risk, dosing by TBW can be considered.

Well-Tolerated Amphotericin B Derivatives That Effectively Treat Visceral Leishmaniasis

Chemotherapy against the neglected tropical disease visceral leishmaniasis (VL) is suboptimal with only four licensed drugs. Amphotericin B (AmB), despite its toxicity, remained a second line drug for a long time. However, the demonstration that liposomal AmB is highly effective against VL propelled it, despite its cost, to a first line drug in many countries. While several ongoing efforts are aiming at finding cheaper and stable AmB-formulations, an alternative strategy is the development of less-toxic AmB derivatives. We show here that two less-toxic AmB derivatives with the carboxylate at position 16 of AmB derivatized to a methyl urea (AmB-MU) or amino urea (AmB-AU) are active in vitro against Leishmania donovani, both as free-living parasites as well as their intracellular form. Both less-toxic derivatives, similarly to AmB, target the ergosterol pathway of L. donovani. While the AmB-AU derivative showed female-specific liver toxicity in vivo, the AmB-MU derivative was well-tolerated and more effective than AmB against experimental VL. These studies are an important step for improving AmB-based therapy against a prevalent parasitic disease.

Pseudozyma spp. human infections: A systematic review

Pseudozyma spp. are described as environmental yeasts but have also been identified as rare human pathogens found in immunocompromised patients. This systematic review details the clinical manifestations, diagnostic methodology, and empirical anti-fungal therapy for this rare yeast. PubMed, LILACS, Scielo, and Web of Science databases were searched for articles about Pseudozyma spp. infections from inception to June 2019. Inclusion criteria were any published studies that included patients with Pseudozyma spp. infection. Infections were identified using criteria set forth by the European Organization for Research and Treatment of Cancer, and were further classified according to clinical, laboratory, or radiologic findings, microbiologic confirmation, and response to therapy. Eleven articles were included with 15 patients. Oncological and/or hematological disorders were the most reported risk factors. Nontraditional microbiological methods correctly identified Pseudozyma spp., whereas traditional methods failed to identify fungal genus. Species were identified by sequencing, and most demonstrated a higher minimal inhibitory concentration (MIC) for fluconazole and echinocandins. MICs for itraconazole, voriconazole, and posaconazole varied by species. All isolates were susceptible to amphotericin B, which was the most used treatment. Pseudozyma spp. infections usually present with fever and are diagnosed by blood culture. Most species studied appeared to be resistant to fluconazole and echinocandin. Voriconazole, posaconazole, and amphotericin were effective in treating P. aphidis. However, more studies are needed to evaluate voriconazole and posaconazole in species other than P. aphidis.

Inhaled Antifungal Agents for the Treatment and Prophylaxis of Pulmonary Mycoses

Pulmonary mycoses are associated with high morbidity and mortality. The current standard treatment by systemic administration is limited by inadequate local bioavailability and systemic toxic effects. Aerosolisation of antifungals is an attractive approach to overcome these problems, but no inhaled antifungal formulation is currently available for the treatment of pulmonary mycoses. Hence, the development of respirable antifungals formulations is of interest and in high demand. In this review, the recent advances in the development of antifungal formulations for pulmonary delivery are discussed, including both nebulised and dry powder formulations. Although the clinical practices of nebulised parenteral amphotericin B and voriconazole formulations (off-label use) are reported to show promising therapeutic effects with few adverse effects, there is no consensus about the dosage regimen (e.g. the dose, frequency, and whether they are used as single or combination therapy). To maximise the benefits of nebulised antifungal therapy, it is important to establish standardised protocol that clearly defines the dose and specifies the device and the administration conditions. Dry powder formulations of antifungal agents such as itraconazole and voriconazole with favourable physicochemical and aerosol properties are developed using various powder engineering technologies, but it is important to consider their suitability for use in patients with compromised lung functions. In addition, more biological studies on the therapeutic efficacy and pharmacokinetic profile are needed to demonstrate their clinical potential.

Multicenter Epidemiologic Study of Coronavirus Disease-Associated Mucormycosis, India

During September-December 2020, we conducted a multicenter retrospective study across India to evaluate epidemiology and outcomes among cases of coronavirus disease (COVID-19)-associated mucormycosis (CAM). Among 287 mucormycosis patients, 187 (65.2%) had CAM; CAM prevalence was 0.27% among hospitalized COVID-19 patients. We noted a 2.1-fold rise in mucormycosis during the study period compared with September-December 2019. Uncontrolled diabetes mellitus was the most common underlying disease among CAM and non-CAM patients. COVID-19 was the only underlying disease in 32.6% of CAM patients. COVID-19-related hypoxemia and improper glucocorticoid use independently were associated with CAM. The mucormycosis case-fatality rate at 12 weeks was 45.7% but was similar for CAM and non-CAM patients. Age, rhino-orbital-cerebral involvement, and intensive care unit admission were associated with increased mortality rates; sequential antifungal drug treatment improved mucormycosis survival. The COVID-19 pandemic has led to increases in mucormycosis in India, partly from inappropriate glucocorticoid use.

Treatment and Prevention of Histoplasmosis in Adults Living with HIV

Histoplasmosis causes life-threatening disseminated infection in adult patients living with untreated HIV. Although disease incidence has declined dramatically in countries with access to antiretroviral therapy, histoplasmosis remains prevalent in many resource-limited regions. A high index of suspicion for histoplasmosis should be maintained in the setting of a febrile multisystem illness in severely immunosuppressed patients, particularly in persons with hemophagocytic lymphohistiocytosis. Preferred treatment regimens for initial therapy include liposomal amphotericin B for severe disease, or itraconazole for mild to moderate disease. Subsequently, itraconazole maintenance therapy should be administered for at least one year and then discontinued if CD4 count increases to ≥150 cells/µL. Antiretroviral therapy, which improves outcome when administered together with an antifungal agent, should be instituted immediately, as the risk of triggering Immune Reconstitution Syndrome is low. The major risk factor for relapsed infection is nonadherence. Itraconazole prophylaxis reduces risk for histoplasmosis in patients with CD4 counts <100/µL but is not associated with survival benefit and is primarily reserved for use in outbreaks. Although most patients with histoplasmosis have not had recognized high-risk exposures, avoidance of contact with bird or bat guano or inhalation of aerosolized soil in endemic regions may reduce risk. Adherence to effective antiretroviral therapy is the most important strategy for reducing the incidence of life-threatening histoplasmosis.

Experience with Liposomal Amphotericin B in Outpatient Parenteral Antimicrobial Therapy

Outpatient parenteral antimicrobial therapy (OPAT) is a safe, effective, and convenient treatment strategy for patients receiving intravenous antimicrobials in the outpatient setting; however, data are limited describing the use and safety of liposomal amphotericin B (L-AMB). Records of patients receiving L-AMB OPAT between 1/1/2015 and 7/31/2018 were retrospectively reviewed. The primary objective was to describe the OPAT patient population discharged on L-AMB and evaluate factors associated with readmission and adverse events (AEs). Analysis was performed to evaluate for predictors of worse outcomes. Forty-two patients (67% male, median age 50 years) were identified, most of whom were treated for histoplasmosis. The most common doses of L-AMB were 3 mg/kg (n = 16, 38%) or 5 mg/kg (n = 14, 33%) based on actual body weight. Twenty-six (62%) patients completed their anticipated course of L-AMB. Twenty-two (52%) patients were readmitted within 30 days of discharge; median time to readmission was 11 days (interquartile range [IQR] 5 to 18). While hypokalemia and acute kidney injury (AKI) were common, occurring in 26 (62%) and 20 (48%) patients, respectively, only 5 (12%) were readmitted to the hospital due to L-AMB-associated AEs. Ninety percent of patients achieved at least partial renal recovery within 30 days after L-AMB discontinuation. Factors significantly associated with AKI include higher L-AMB dose, lower serum potassium levels after therapy initiation, and receipt of potassium supplementation at discharge. L-AMB is associated with significant AEs; however, these results suggest that treatment is feasible in the outpatient setting with close monitoring, as the majority of AEs were managed effectively in an outpatient without long-term sequelae.

A Rare Case of Brain Abscesses Caused by Acremonium Species

Acremonium species are saprophytic fungi that are rarely pathogenic in humans. According to several reports, Acremonium species can cause various diseases, ranging from superficial infections after traumatic inoculation in immunocompetent individuals to invasive infections in the immunocompromised. To the best of our knowledge, this is the first case report of brain abscess in an 18-year-old male caused by Acremonium species in Pakistan. A combination of intravenous amphotericin B and oral voriconazole was administered to the patient, which resulted in marked clinical improvement. However, the recurrence of fungiwas observed after three months of completion of the antifungal course. The purpose of this report is to alert clinicians regarding this pathogen and its ability to cause systemic disease.

Comparative Transcriptome Analysis of Streptomyces nodosus Mutant With a High-Yield Amphotericin B

Antibiotics play an important role in human health. Most antibiotics are derived from microbial secondary metabolites. Amphotericin is a polyene macrolide antibiotic synthesized by Streptomyces nodosus. S. nodosus ZJB2016050 with high-yield amphotericin B (AmB) was obtained by traditional mutagenesis using S. nodosus ATCC14899 as the original strain. The differences in the characterization of the two strains were found in color, mycelium morphology, and AmB yield. Subsequent comparative transcriptome explained the yield differences between the two strains. Pathways including the carbohydrate metabolic pathway and the secondary product synthesis pathway were targeted. The upregulation of glucokinase, phosphoglycerate mutase, and pyruvate dehydrogenase accelerates the consumption of glucose and has great effects on the accumulation of precursors. One of the competitive secondary metabolites of the polyketone synthetase (PKS) II type sapromomycin analog synthesis gene cluster was downregulated, which competes for malonyl-CoA. Five PKS modules (except for the first module amphA) of the amphotericin synthetic gene cluster in the high-yielding strain were downregulated, which resulted in the total amphotericin A (AmA) and AmB of S. nodosus ZJB2016050 being less than that of the wild-type S. nodosus ATCC14899. Combined with gene differential expression in the pentose phosphate pathway and the reaction mechanism of the ER5 domain, the reason that S. nodosus ZJB2016050 preferred to synthesize AmB was probably related to intracellular reduction.

Lactoferrin-Derived Peptide Lactofungin Is Potently Synergistic with Amphotericin B

Lactoferrin (LF) is an iron-binding glycoprotein with broad-spectrum antimicrobial activity. Previously, we discovered that LF synergistically enhanced the antifungal efficacy of amphotericin B (AMB) across a variety of yeast species and subsequently hypothesized that this synergy was enhanced by the presence of small peptides derived from the whole LF molecule. In this study, LF was digested with pepsin under a range of conditions. The resulting hydrolysates exhibited enhanced synergy with AMB compared to its synergy with undigested LF. Samples were analyzed using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, and 14 peptides were identified. The sequences of these peptides were predicted by matching their molecular weights to those of a virtual digest with pepsin. The relative intensities of predicted peptides in each hydrolysate were compared with the activity of the hydrolysate, and the structural and physicochemical properties of the peptides were assessed. From this, a 30-residue peptide was selected for synthesis and dubbed lactofungin (LFG). Pure LFG was highly synergistic with AMB, outperforming native LF in all fungal species tested. With potential for further structural and chemical improvements, LFG is an excellent lead for development as an antifungal adjuvant.

Amphotericin B Specifically Induces the Two-Component System LnrJK: Development of a Novel Whole-Cell Biosensor for the Detection of Amphotericin-Like Polyenes

The rise of drug-resistant fungal pathogens urges for the development of new tools for the discovery of novel antifungal compounds. Polyene antibiotics are potent agents against fungal infections in humans and animals. They inhibit the growth of fungal cells by binding to sterols in the cytoplasmic membrane that subsequently causes pore formation and eventually results in cell death. Many polyenes are produced by Streptomycetes and released into the soil environment, where they can then target fungal hyphae. While not antibacterial, these compounds could nevertheless be also perceived by bacteria sharing the same habitat and serve as signaling molecules. We therefore addressed the question of how polyenes such as amphotericin B are perceived by the soil bacterium, Bacillus subtilis. Global transcriptional profiling identified a very narrow and specific response, primarily resulting in strong upregulation of the lnrLMN operon, encoding an ABC transporter previously associated with linearmycin resistance. Its strong and specific induction prompted a detailed analysis of the lnrL promoter element and its regulation. We demonstrate that the amphotericin response strictly depends on the two-component system LnrJK and that the target of LnrK-dependent gene regulation, the lnrLMN operon, negatively affects LnrJK-dependent signal transduction. Based on this knowledge, we developed a novel whole-cell biosensor, based on a P_lnrL-lux fusion reporter construct in a lnrLMN deletion mutant background. This highly sensitive and dynamic biosensor is ready to be applied for the discovery or characterization of novel amphotericin-like polyenes, hopefully helping to increase the repertoire of antimycotic and antiparasitic polyenes available to treat human and animal infections.

Cryptococcal meningitis: a review of cryptococcal antigen screening programs in Africa

INTRODUCTION

Cryptococcal meningitis remains a significant contributor to AIDS-related mortality despite widened access to antiretroviral therapy. Cryptococcal antigen (CrAg) can be detected in the blood prior to development of meningitis. Development of highly sensitive and specific rapid diagnostic CrAg tests has helped facilitate the adoption of CrAg screening programs in 19 African countries.

AREAS COVERED

The biological rationale for CrAg screening and the programmatic strategies for its implementation are reviewed. We describe the approach to the investigation of patients with cryptococcal antigenemia and the importance of lumbar puncture to identify individuals who may have cryptococcal meningitis in the absence of symptoms. The limitations of current treatment recommendations and the potential role of newly defined combination antifungal therapies are discussed. A literature review was conducted using a broad database search for cryptococcal antigen screening and related terms in published journal articles dating up to December 2019. Conference abstracts, publicly available guidelines, and project descriptions were also incorporated.

EXPERT OPINION

As we learn more about the risks of cryptococcal antigenemia, it has become clear that the current management paradigm is inadequate. More intensive investigation and management are required to prevent the development of cryptococcal meningitis and reduce mortality associated with cryptococcal antigenemia.

Lathosterol Oxidase (Sterol C-5 Desaturase) Deletion Confers Resistance to Amphotericin B and Sensitivity to Acidic Stress in Leishmania major

Sterols are essential membrane components in eukaryotes, and sterol synthesis inhibitors can have potent effects against pathogenic fungi and trypanosomatids. Understanding the roles of sterols will facilitate the development of new drugs and counter drug resistance. LSO is required for the formation of the C-5–C-6 double bond in the sterol core structure in mammals, fungi, protozoans, plants, and algae. Functions of this C-5–C-6 double bond are not well understood. In this study, we generated and characterized a lathosterol oxidase-null mutant in Leishmania major. Our data suggest that LSO is vital for the structure and membrane-stabilizing functions of leishmanial sterols. In addition, our results imply that while mutations in lathosterol oxidase can confer resistance to amphotericin B, an important antifungal and antiprotozoal agent, the alteration in sterol structure leads to significant defects in stress response that could be exploited for drug development.

Lathosterol oxidase (LSO) catalyzes the formation of the C-5–C-6 double bond in the synthesis of various types of sterols in mammals, fungi, plants, and protozoa. In Leishmania parasites, mutations in LSO or other sterol biosynthetic genes are associated with amphotericin B resistance. To investigate the biological roles of sterol C-5–C-6 desaturation, we generated an LSO-null mutant line (lso⁻) in Leishmania major, the causative agent for cutaneous leishmaniasis. lso⁻ parasites lacked the ergostane-based sterols commonly found in wild-type L. major and instead accumulated equivalent sterol species without the C-5–C-6 double bond. These mutant parasites were replicative in culture and displayed heightened resistance to amphotericin B. However, they survived poorly after reaching the maximal density and were highly vulnerable to the membrane-disrupting detergent Triton X-100. In addition, lso⁻ mutants showed defects in regulating intracellular pH and were hypersensitive to acidic conditions. They also had potential alterations in the carbohydrate composition of lipophosphoglycan, a membrane-bound virulence factor in Leishmania. All these defects in lso⁻ were corrected upon the restoration of LSO expression. Together, these findings suggest that the C-5–C-6 double bond is vital for the structure of the sterol core, and while the loss of LSO can lead to amphotericin B resistance, it also makes Leishmania parasites vulnerable to biologically relevant stress.

IMPORTANCE Sterols are essential membrane components in eukaryotes, and sterol synthesis inhibitors can have potent effects against pathogenic fungi and trypanosomatids. Understanding the roles of sterols will facilitate the development of new drugs and counter drug resistance. LSO is required for the formation of the C-5–C-6 double bond in the sterol core structure in mammals, fungi, protozoans, plants, and algae. Functions of this C-5–C-6 double bond are not well understood. In this study, we generated and characterized a lathosterol oxidase-null mutant in Leishmania major. Our data suggest that LSO is vital for the structure and membrane-stabilizing functions of leishmanial sterols. In addition, our results imply that while mutations in lathosterol oxidase can confer resistance to amphotericin B, an important antifungal and antiprotozoal agent, the alteration in sterol structure leads to significant defects in stress response that could be exploited for drug development.

A Method for the Evaluation of Site-Specific Nephrotoxic Injury in the Intact Rat Kidney

In a previously published report we detailed an in situ method to quantify cell death in the renal cortex by perfusing the cell membrane impermeable fluorochrome, ethidium homodimer in situ. The objective of the present study was to use this in situ viability assay to examine cell death following the administration of nephrotoxic drugs known to produce cell death and/or injury in specific segments of the nephron. Male Sprague/Dawley rats were treated with the following nephrotoxicants: Gentamicin, amphotericin-B, and indomethacin. Results of the in situ viability assay indicated that gentamicin and amphotericin-B treatment caused cell death localized in the kidney cortex and medulla, respectively. The urinary biomarker kidney injury molecule-1 (Kim-1) showed significant increases in both gentamicin (20 fold increase) and amphotericin-B-treated (9.2 fold increase) animals. Urinary alpha glutathione-S-transferase (GST) showed significant increases for gentamicin (6.2 fold increase) only and mu GST for amphotericin-B-treated (19.1 fold increase) animals only. These results show that this in situ viability assay provides a sensitive method to identify cell death in different regions of the kidney. Furthermore, urinary alpha GST and mu GST are specific for proximal and distal tubule injury, respectively; urinary Kim-1 demonstrated greater sensitivity to both proximal and distal tubule injury.

Short-course amphotericin B in addition to sertraline and fluconazole for treatment of HIV-associated cryptococcal meningitis in rural Tanzania

BACKGROUND

Cryptococcal meningitis accounts for 15% of all AIDS mortality globally. Most cases in low- and middle-income countries are treated with fluconazole monotherapy, which is associated with a high mortality. New available therapies are needed. Short-course amphotericin B has been shown to be a safe and efficient therapeutic option. Sertraline has in vitro fungicidal activity against Cryptococcus and bi-directional synergy with fluconazole.

METHODS

We conducted an open-label clinical trial to assess the safety and efficacy of sertraline 400 mg/day and fluconazole 1200 mg/day (n = 28) vs sertraline, fluconazole and additional 5 days of amphotericin B deoxycholate 0.7-1 mg/kg (n = 18) for cryptococcal meningitis.

RESULTS

Two-week survival was 64% (18/28) without amphotericin and 89% (16/18) with amphotericin, and 10-week survival was 21% (6/28) vs 61% (11/18), respectively (P = .012). The cerebrospinal fluid (CSF) Cryptococcus clearance rate was 0.264 log₁₀ colony-forming units (CFU)/mL of CSF/day (95% CI: 0.112-0.416) without amphotericin and 0.473 log₁₀ CFU/mL/day (95% CI: 0.344-0.60) with short-course amphotericin (P = .03). Sertraline was discontinued in one participant due to side effects. Four participants receiving amphotericin B experienced hypokalemia <2.4 mEq/L.

CONCLUSIONS

Short-course amphotericin substantially increased CSF clearance and 10-week survival. Adjunctive sertraline improved 2-week CSF fungal clearance but did not improve 10-week mortality compared with published data using fluconazole 1200 mg/day monotherapy (early fungicidal activity 0.15 log₁₀ CFU/mL/day).

Short-Course Rather Than Low-Dose Amphotericin B May Exert Potential Influence on Mortality in Cryptococcal Meningitis Patients Treated With Amphotericin B Plus Flucytosine Alone or in Combination With Fluconazole

Background

The influence of Amphotericin B (AmB) dose and the addition of fluconazole (Flu) on the AmB + 5-flucytosine (5FC) regimen for cryptococcal meningitis (CM) treatment remain debatable.

Methods

A retrospective study was conducted to compare 44 CM patients treated with AmB + 5FC and 78 CM patients treated with AmB + 5FC + Flu using the propensity score matching method. The effects of AmB dosage, AmB course and Flu addition on the cerebrospinal fluid (CSF) chemical profile recovery, adverse effects, and 90-day mortality were compared between the groups.

Results

No differences in adverse effects, the rate of the 14-day CSF chemical profile recovery and 90-day cumulative survival rate (91.2% vs. 87.5%, P = 0.637) were observed between the AmB + 5FC group and the AmB + 5FC + Flu group. However, the incidence rates of hypokalemia (33.9%) and creatinine elevation (7.1%) in patients treated with an AmB dosage of 0.4–0.5 mg/kg/d were less than those (53.0 and 22.7%, respectively) treated with an AmB dosage of 0.6–0.7 mg/kg/d (P = 0.034 and P = 0.018, respectively). The 90-day cumulative survival rate was 70.1% for patients treated with AmB for <14 days and 96.4% for patients treated with AmB for ≥14 days (log-rank P < 0.001). Multivariate Cox proportional hazards models suggested the hazard ratio was 26.8 (95% CI: 3.9–183.2) for patients treated with AmB < 14 days than those treated with AmB ≥ 14 days (P = 0.001).

Conclusion

Treatment with AmB less than 14 days was associated with a higher 90-day mortality in CM patients. A relative lower dosage but prolonged course of AmB in the +5FC ± Flu regimen led to favorable trends of fewer adverse effects and comparable clinical efficacy.

Efficacy of Oral Encochleated Amphotericin B in a Mouse Model of Cryptococcal Meningoencephalitis

Cryptococcus neoformans is an encapsulated yeast responsible for approximately a quarter of a million deaths worldwide annually despite therapy, and upwards of 11% of HIV/AIDS-related deaths, rivaling the impact of tuberculosis and malaria. However, the most effective antifungal agent, amphotericin B, requires intravenous delivery and has significant renal and hematopoietic toxicity, making it difficult to utilize, especially in resource-limited settings. The present studies describe a new nanoparticle crystal encapsulated formulation of amphotericin B known as encochleated amphotericin B (CAmB) that seeks to provide an oral formulation that is low in toxicity and cost. Using a 3-day delayed model of murine cryptococcal meningoencephalitis and a large inoculum of a highly virulent strain of serotype A C. neoformans, CAmB, in combination with flucytosine, was found to have efficacy equivalent to parental amphotericin B deoxycholate with flucytosine and superior to oral fluconazole without untoward toxicity. Transport of fluorescent CAmB particles to brain as well as significant brain levels of amphotericin drug was demonstrated in treated mice, and immunological profiles were similar to those of mice treated with conventional amphotericin B. Additional toxicity studies using a standardized rat model showed negligible toxicity after a 28-day treatment schedule. These studies thus offer the potential for an efficacious oral formulation of a known fungicidal drug against intrathecal cryptococcal disease.IMPORTANCE Cryptococcus neoformans is a significant global fungal pathogen that kills an estimated quarter of a million HIV-infected individuals yearly and has poor outcomes despite therapy. The most effective therapy, amphotericin B, is highly effective in killing the fungus but is available only in highly toxic, intravenous formulations that are unavailable in most of the developing world, where cryptococcal disease in most prevalent. For example, in Ethiopia, reliance on the orally available antifungal fluconazole results in high mortality, even when initiated as preemptive therapy at the time of HIV diagnosis. Thus, alternative agents could result in significant saving of lives. Toward this end, the present work describes the development of a new formulation of amphotericin B (CAmB) that encapsulates the drug as a crystal lipid nanoparticle that facilitates oral absorption and prevents toxicity. Successful oral absorption of the drug was demonstrated in a mouse model that, in combination with the antifungal flucytosine, provided efficacy equal to a parental preparation of amphotericin B plus flucytosine. These studies demonstrate the potential for CAmB in combination with flucytosine to provide an effective oral formulation of a well-known, potent fungicidal drug combination.

Electrochemical Response of Saccharomyces cerevisiae Corresponds to Cell Viability upon Exposure to Dioclea reflexa Seed Extracts and Antifungal Drugs

Dioclea reflexa bioactive compounds have been shown to contain antioxidant properties. The extracts from the same plant are used in traditional medical practices to treat various diseases with impressive outcomes. In this study, ionic mobility in Saccharomyces cerevisiae cells in the presence of D. reflexa seed extracts was monitored using electrochemical detection methods to link cell death to ionic imbalance. Cells treated with ethanol, methanol, and water extracts were studied using cyclic voltammetry and cell counting to correlate electrochemical behavior and cell viability, respectively. The results were compared with cells treated with pore-forming Amphotericin b (Amp b), as well as Fluconazole (Flu) and the antimicrobial drug Rifampicin (Rif). The D. reflexa seed water extract (SWE) revealed higher anodic peak current with 58% cell death. Seed methanol extract (SME) and seed ethanol extract (SEE) recorded 31% and 22% cell death, respectively. Among the three control drugs, Flu revealed the highest cell death of about 64%, whereas Amp b and Rif exhibited cell deaths of 35% and 16%, respectively, after 8 h of cell growth. It was observed that similar to SWE, there was an increase in the anodic peak current in the presence of different concentrations of Amp b, which also correlated with enhanced cell death. It was concluded from this observation that Amp b and SWE might follow similar mechanisms to inhibit cell growth. Thus, the individual bioactive compounds from the water extracts of D. reflexa seeds could further be purified and tested to validate their potential therapeutic application. The strategy to link electrochemical behavior to biochemical responses could be a simple, fast, and robust screening technique for new drug targets and to understand the mechanism of action of such drugs against disease models.

Population Pharmacodynamics of Amphotericin B Deoxycholate for Disseminated Infection Caused by Talaromyces marneffei

Amphotericin B deoxycholate (DAmB) is a first-line agent for the initial treatment of talaromycosis. However, little is known about the population pharmacokinetics and pharmacodynamics of DAmB for talaromycosis. Pharmacokinetic data were obtained from 78 patients; among them, 55 patients had serial fungal CFU counts in blood also available for analysis. A population pharmacokinetic-pharmacodynamic model was fitted to the data. The relationships between the area under the concentration-time curve (AUC)/MIC and the time to blood culture sterilization and the time to death were investigated. There was only modest pharmacokinetic variability in the average AUC, with a mean ± standard deviation of 11.51 ± 3.39 mg·h/liter. The maximal rate of drug-induced kill was 0.133 log10 CFU/ml/h, and the plasma concentration of the DAmB that induced the half-maximal rate of kill was 0.02 mg/liter. Fifty percent of patients sterilized their bloodstreams by 83.16 h (range, 13 to 264 h). A higher initial fungal burden was associated with a longer time to sterilization (hazard ratio [HR], 0.51; 95% confidence interval [CI], 0.36 to 0.70; P < 0.001). There was a weak relationship between AUC/MIC and the time to sterilization, although this did not reach statistical significance (HR, 1.03; 95% CI, 1.00 to 1.06, P = 0.091). Furthermore, there was no relationship between the AUC/MIC and time to death (HR, 0.97; 95% CI, 0.88 to 1.08; P = 0.607) or early fungicidal activity {slope = log[(0.500 - 0.003·(AUC/MIC)]; P = 0.319} adjusted for the initial fungal burden. The population pharmacokinetics of DAmB are surprisingly consistent. The time to sterilization of the bloodstream may be a useful pharmacodynamic endpoint for future studies. (This study has been registered at the ISRCTN registry under no. ISRCTN59144167.).

Short-course High-dose Liposomal Amphotericin B for Human Immunodeficiency Virus-associated Cryptococcal Meningitis: A Phase 2 Randomized Controlled Trial

Background

We performed a phase 2 noninferiority trial examining the early fungicidal activity (EFA) of 3 short-course, high-dose liposomal amphotericin B (L-AmB) regimens for cryptococcal meningitis (CM) in Tanzania and Botswana.

Methods

Human immunodeficiency virus (HIV)-infected adults with CM were randomized to (i) L-AmB 10 mg/kg on day 1 (single dose); (ii) L-AmB 10 mg/kg on day 1 and 5 mg/kg on day 3 (2 doses); (iii) L-AmB 10 mg/kg on day 1 and 5 mg/kg on days 3 and 7 (3 doses); or (iv) L-AmB 3 mg/kg/day for 14 days (control). All patients also received oral fluconazole 1200 mg/day for 14 days. Primary endpoint was mean rate of clearance of cerebrospinal fluid cryptococcal infection (EFA). Noninferiority was defined as an upper limit of the 2-sided 95% confidence interval (CI) of difference in EFA between intervention and control <0.2 log10 colony-forming units (CFU)/mL/day.

Results

Eighty participants were enrolled. EFA for daily L-AmB was -0.41 log10 CFU/mL/day (standard deviation, 0.11; n = 17). Difference in mean EFA from control was -0.11 (95% CI, -.29 to .07) log10 CFU/mL/day faster with single dose (n = 16); -0.05 (95% CI, -.20 to .10) log10 CFU/mL/day faster with 2 doses (n = 18); and -0.13 (95% CI, -.35 to .09) log10 CFU/mL/day faster with 3 doses (n = 18). EFA in all short-course arms was noninferior to control. Ten-week mortality was 29% (n = 23) with no statistical difference between arms. All arms were well tolerated.

Conclusions

Single-dose 10 mg/kg L-AmB was well tolerated and led to noninferior EFA compared to 14 days of 3 mg/kg/day L-AmB in HIV-associated CM. Induction based on a single 10 mg/kg L-AmB dose is being taken forward to a phase 3 clinical endpoint trial.

Clinical Trials Registration

ISRCTN 10248064.

Permeability Characteristics of a New Antifungal Topical Amphotericin B Formulation with γ-Cyclodextrins

Amphotericin B is a low soluble broad-spectrum antifungal agent. Cyclodextrins can be added to amphotericin formulations to enhance both their solubility and antifungal properties. Semisolid amphotericin formulations containing gamma cyclodextrin (AGCD) were prepared and compared with two reference formulations—one of them without any solubility enhancer (A) and the other with DMSO (ADMSO). Rheological, the permeability through hairless mouse skin and antifungal characteristics of the different formulations were evaluated. All three semisolid formulations show low thixotropy characteristics. ADMSO was the formulation with the least consistency, lowest viscosity, and greatest extensibility. The AGCD formulation had the opposite behavior and had both the greatest consistency and viscosity and the lowest extensibility. The lowest permeability was obtained with the reference A formulation while both AGCD and ADMSO had a similar permeability enhancement. According to the antimicrobial in vitro efficacy trials, the AGCD formulation showed 45–60% more activity than the reference A formulation. It can be concluded that γ-cyclodextrin is a useful excipient to improve the solubility, permeability, and antifungal activity of amphotericin B in semisolid topical formulations.

Treatment of Aspergillosis

Infections caused by Aspergillus spp. remain associated with high morbidity and mortality. While mold-active antifungal prophylaxis has led to a decrease of occurrence of invasive aspergillosis (IA) in those patients most at risk for infection, breakthrough IA does occur and remains difficult to diagnose due to low sensitivities of mycological tests for IA. IA is also increasingly observed in other non-neutropenic patient groups, where clinical presentation is atypical and diagnosis remains challenging. Early and targeted systemic antifungal treatment remains the most important predictive factor for a successful outcome in immunocompromised individuals. Recent guidelines recommend voriconazole and/or isavuconazole for the primary treatment of IA, with liposomal amphotericin B being the first alternative, and posaconazole, as well as echinocandins, primarily recommended for salvage treatment. Few studies have evaluated treatment options for chronic pulmonary aspergillosis (CPA), where long-term oral itraconazole or voriconazole remain the treatment of choice.

In-Vitro Activity of Silybin and Related Flavonolignans against Leishmania infantum and L. donovani

Flavonolignans from the seeds of the milk thistle (Silybum marianum) have been extensively used in folk medicine for centuries. Confirmation of their properties as hepatoprotective, antioxidant and anticancer has been obtained using standardized extracts and purified flavonolignans. Information on their potential effect on Leishmania is very scarce. We have investigated the effect of silymarin, silybin and related flavonolignans on the multiplication of promastigotes in vitro and ex vivo on intracellular amastigotes of L. infantum (Li) and L. donovani (Ld), causative agents of human and canine visceral leishmaniasis (VL). In addition, the potential synergistic effect of the most active molecule and well-established antileishmanial drugs against promastigotes was explored. Dehydroisosilybin A elicited the highest inhibition against Ld and Li promastigotes with an approximate IC₅₀ of 90.23 µM. This molecule showed a moderate synergism with amphotericin B (AmB) but not with Sb^III or paromomycin, although it was ineffective against amastigotes. Antileishmanial activity on intracellular amastigotes of the two diastereoisomers of dehydrosilybin (10 µM) was comparable to that elicited by 0.1 µM AmB. Antiproliferative activity and safety of flavonolignans suggest the interest of exploring their potential value in combination therapy against VL.

Impact of high MIC of fluconazole on outcomes of Candida glabrata bloodstream infection: a retrospective multicenter cohort study

To evaluate the impacts of fluconazole minimum inhibitory concentration (MIC) according to primary antifungal agents on Candida glabrata bloodstream infection (BSI), a multicenter retrospective cohort study was conducted in Korea, concerning the time period from January 2010 to February 2016. A total of 197 adult patients with C. glabrata BSI were included in the study, and neutropenia (P = 0.026), APACHE II score (P = 0.004), and fluconazole resistance (HR 3.960, 95% CI 1.395-11.246, P = 0.010) were associated with 30-day mortality in multivariate analysis. In subgroup analysis, fluconazole MIC = 32 μg/mL in the azole-treated group (HR 6.691, 95% CI 1.569-28.542, P = 0.010) and fluconazole MIC ≥ 64 μg/mL in the non-azole-treated group (HR 3.337, 95% CI 1.183-9.411, P = 0.023) showed the highest hazard ratio (HR) for 30-day mortality. Increased fluconazole MIC was associated with poor outcome both in azole- and non-azole-treated patients with C. glabrata BSI.

Executive Summary: Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Cryptococcal meningitis in AIDS

Cryptococcal meningitis remains a significant cause of morbidity and mortality amongst patients living with human immunodeficiency virus (HIV). The prevalence in the developed world has decreased as HIV is being diagnosed earlier, but is still significant, and the prevalence in resource-limited settings is exceedingly high. The presenting symptoms usually include a headache, fever, and, less often, cranial nerve abnormalities. Space-occupying lesions do occur, but are rare. Once diagnosed, patients should be treated with a combination of amphotericin and flucytosine, with step-down therapy to fluconazole for a minimum of a year, or until the CD4 count is above 100 cells/μL, whichever is longer. In the acute phase of treatment increased opening pressure is common, which should be managed aggressively with frequent lumbar punctures, or through neurosurgical interventions (lumbar drains, ventriculoperitoneal shunts) if those fail. Antiretrovirals should be delayed at least 2 weeks, but maybe as many as 10 weeks, after initiation of antifungal therapy in order to prevent clinical or subclinical immune reconstitution inflammatory syndrome (IRIS), which may lead to increased mortality. However, if IRIS does develop, there is no role for antiretroviral interruption, and the condition should be managed supportively by use of anti-inflammatories and aggressive management of elevated opening pressure, if present. Steroids should be administered for specific indications only (IRIS or cryptococcoma with cerebral edema and risk of herniation) as routine use of steroids increases mortality in cryptococcal meningitis.