Managing secondary fungal infections in severe COVID-19: how to move forward?

Nanoformulations for dismantling fungal biofilms: The latest arsenals of antifungal therapy

Globally, fungal infections have evolved as a strenuous challenge for clinicians, particularly in patients with compromised immunity in intensive care units. Fungal co-infection in Covid-19 patients has made the situation more formidable for healthcare practitioners. Surface adhered fungal population known as biofilm often develop at the diseased site to elicit antifungal tolerance and recalcitrant traits. Thus, an innovative strategy is required to impede/eradicate developed biofilm and avoid the formation of new colonies. The development of nanocomposite-based antibiofilm solutions is the most appropriate way to withstand and dismantle biofilm structures. Nanocomposites can be utilized as a drug delivery medium and for fabrication of anti-biofilm surfaces capable to resist fungal colonization. In this context, the present review comprehensively described different forms of nanocomposites and mode of their action against fungal biofilms. Amongst various nanocomposites, efficacy of metal/organic nanoparticles and nanofibers are particularly emphasized to highlight their role in the pursuit of antibiofilm strategies. Further, the inevitable concern of nanotoxicology has also been introduced and discussed with the exigent need of addressing it while developing nano-based therapies. Further, a list of FDA-approved nano-based antifungal formulations for therapeutic usage available to date has been described. Collectively, the review highlights the potential, scope, and future of nanocomposite-based antibiofilm therapeutics to address the fungal biofilm management issue.

COVID-19 associated Pulmonary Aspergillosis in Patients Admitted to the Intensive Care Unit: Impact of Antifungal Prophylaxis

Early after the beginning of the coronavirus disease 2019 (COVID-19)-pandemic, it was observed that critically ill patients in the intensive care unit (ICU) were susceptible to developing secondary fungal infections, particularly COVID-19 associated pulmonary aspergillosis (CAPA). Here we report our local experience on the impact of mold active antifungal prophylaxis on CAPA occurrence in critically ill COVID-19 patients. This is a monocentric, prospective cohort study including all consecutive patients with COVID-19 associated acute respiratory failure who were admitted to our local medical ICU. Based on the treating physician's discretion, patients may have received antifungal prophylaxis or not. All patients were retrospectively characterized as having CAPA according to the 2020 ECMM/ISHAM consensus definitions. Seventy-seven patients were admitted to our medical ICU during April 2020 and May 2021 and included in the study. The majority of patients received invasive-mechanical ventilation (61%). Fifty-three patients (68.8%) received posaconazole prophylaxis. Six cases of probable CAPA were diagnosed within clinical routine management. All six cases were diagnosed in the non-prophylaxis group. The incidence of CAPA in the overall study cohort was 0.57 events per 100 ICU days and 2.20 events per 100 ICU days in the non-prophylaxis group. No difference of cumulative 84-days survival could be observed between the two groups (p = 0.115). In this monocentric cohort, application of posaconazole prophylaxis in patients with COVID-19 associated respiratory failure did significantly reduce the rate of CAPA.

Pulmonary Aspergillosis in Critically Ill COVID-19 Patients Admitted to the Intensive Care Unit: A Retrospective Cohort Study

COVID-19-associated pulmonary aspergillosis (CAPA) is a life-threatening fungal infection that mainly affects critically ill patients. The aim of this study was to assess the incidence and clinical outcomes of putative CAPA in critically ill COVID-19 patients. This retrospective observational cohort study included 181 cases from 5 ICUs at Vienna General Hospital between January 2020 and April 2022. Patients were diagnosed with putative CAPA according to the AspICU classification, which included a positive Aspergillus culture in a bronchoalveolar lavage sample, compatible signs and symptoms, and abnormal medical imaging. The primary outcome was adjusted 60-day all-cause mortality from ICU admission in patients with vs. without putative CAPA. Secondary outcomes included time from ICU admission to CAPA diagnosis and pathogen prevalence and distribution. Putative CAPA was identified in 35 (19.3%) of 181 COVID-19 patients. The mean time to diagnosis was 9 days. Death at 60 days occurred in 18 of 35 (51.4%) patients with CAPA and in 43 of 146 (29.5%) patients without CAPA (adjusted HR (95%CI) = 2.15 (1.20–3.86, p = 0.002). The most frequently isolated Aspergillus species was Aspergillus fumigatus. The prevalence of putative pulmonary aspergillosis in critically ill COVID-19 patients was high and was associated with significantly higher mortality.

Addressing a future pandemic: how can non-biological complex drugs prepare us for antimicrobial resistance threats?

Loss of effective antibiotics through antimicrobial resistance (AMR) is one of the greatest threats to human health. By 2050, the annual death rate resulting from AMR infections is predicted to have climbed from 1.27 million per annum in 2019, up to 10 million per annum. It is therefore imperative to preserve the effectiveness of both existing and future antibiotics, such that they continue to save lives. One way to conserve the use of existing antibiotics and build further contingency against resistant strains is to develop alternatives. Non-biological complex drugs (NBCDs) are an emerging class of therapeutics that show multi-mechanistic antimicrobial activity and hold great promise as next generation antimicrobial agents. We critically outline the focal advancements for each key material class, including antimicrobial polymer materials, carbon nanomaterials, and inorganic nanomaterials, and highlight the potential for the development of antimicrobial resistance against each class. Finally, we outline remaining challenges for their clinical translation, including the need for specific regulatory pathways to be established in order to allow for more efficient clinical approval and adoption of these new technologies.

Improved absorption of itraconazole tablet by co-administration with lemon beverages in a lung transplant recipient: A case report

After lung transplantation, itraconazole (ITCZ) is used as a prophylaxis for aspergillosis. ITCZ is a weak base with high lipophilicity, and the dissolution and absorption of ITCZ tablets and capsules are pH dependent. Therefore, ITCZ may not achieve sufficient serum concentrations in patients with higher gastric pH because of its poor bioavailability. We report a case of a woman in fifties with post-COVID-19 respiratory failure who successfully underwent lung transplantation, followed by improved bioavailability of ITCZ tablets when given with acidic lemon beverages. The patient was initially administered ITCZ oral solution; this was discontinued because of its unpleasant taste, nausea, and vomiting. The ITCZ oral solution was replaced with ITCZ tablets 78 days after transplantation; however, serum concentrations of ITCZ and hydroxy-ITCZ were below the detection limit (100 ng/mL). We co-administered ITCZ tablets with commercially available lemon beverages. Subsequently, serum concentrations of ITCZ and hydroxy-ITCZ increased to 341 and 673 ng/mL, respectively, on the 125th day after transplantation. Infection with fungi, including Aspergillus spp., was not observed in this case. The patient had no adverse events such as gastric ulcer or hyperglycemia. These results suggest that the co-administration of lemon beverages and ITCZ tablets may help achieve better absorption of ITCZ in patients taking acid suppressants.

Nebulized Amphotericin B in Mechanically Ventilated COVID-19 Patients to Prevent Invasive Pulmonary Aspergillosis: A Retrospective Cohort Study

Despite high mortality rates of COVID-19-associated pulmonary aspergillosis (CAPA) in the ICU, antifungal prophylaxis remains a subject of debate. We initiated nebulized conventional amphotericin B (c-AmB) as antifungal prophylaxis in COVID-19 patients on invasive mechanical ventilation (IMV).

OBJECTIVES

To assess the CAPA incidence in COVID-19 patients on IMV treated with and without nebulized c-AmB as antifungal prophylaxis.

DESIGN SETTING AND PARTICIPANTS

Retrospective cohort study of consecutive COVID-19 patients admitted to our adult 17-bed ICU in a university-affiliated general hospital in Ede, The Netherlands, between January 25, 2021, and July 9, 2021. Patients not requiring IMV or transferred from or to another ICU were excluded. From April 9, 2021, daily nebulized amphotericin B in all patients on IMV was initiated.

MAIN OUTCOMES AND MEASURES

Bronchoscopy with bronchoalveolar lavage (BAL) was performed in case of positive cultures for Aspergillus from the respiratory tract and/or unexplained respiratory deterioration. Incidence of probable and proven CAPA was compared between patients treated with and without nebulized antifungal prophylaxis using Pearson chi-square test.

RESULTS

A total of 39 intubated COVID-19 patients could be analyzed, of which 16 were treated with antifungal prophylaxis and 23 were not. Twenty-six patients underwent bronchoscopy with BAL. In patients treated with antifungal prophylaxis, the incidence of probable/proven CAPA was significantly lower when compared with no antifungal prophylaxis (27% vs 67%; p = 0.047). Incidence of tracheobronchial lesions and positive Aspergillus cultures and BAL-galactomannan was significantly lower in patients treated with antifungal prophylaxis (9% vs 47%; p = 0.040, 9% vs 53%; p = 0.044, and 20% vs 60%; p = 0.047, respectively). No treatment-related adverse events and no case of proven CAPA were encountered in patients receiving antifungal prophylaxis.

CONCLUSIONS AND RELEVANCE

Nebulization of c-AmB in critically ill COVID-19 patients on IMV is safe and may be considered as antifungal prophylaxis to prevent CAPA. However, a randomized controlled trial to confirm this is warranted.