Effects of amphotericin B gargles on oral colonization of Candida albicans in asthmatic patients on steroid inhalation therapy

Monitoring Phenotypic Switching in Candida albicans and the Use of Next-Gen Fluorescence Reporters

Candida albicans is an opportunistic human fungal pathogen that is able to cause both mucosal and systemic infections. It is also a frequent human commensal, where it is typically found inhabiting multiple niches including the gastrointestinal tract. One of the most remarkable features of C. albicans biology is its ability to undergo heritable and reversible switching between different phenotypic states, a phenomenon known as phenotypic switching. This is best exemplified by the white-opaque switch, in which cells undergo epigenetic transitions between two alternative cellular states. Here, we describe assays to quantify the frequency of switching between states, as well as methods to help identify cells in different phenotypic states. We also describe the use of environmental cues that can induce switching into either the white or opaque state. Finally, we introduce the use of mNeonGreen and mScarlet fluorescent proteins that have been optimized for use in C. albicans and which outperform commonly used fluorescent proteins for both fluorescence microscopy and flow cytometry. © 2019 by John Wiley & Sons, Inc.

Dysphonia associated with the use of inhaled corticosteroids

PURPOSE OF REVIEW

This article discusses the relationship between inhaled corticosteroids and dysphonia, with discussion of the therapeutic use of inhaled steroids in laryngeal disease and a review of negative laryngeal effects of this class of medication in patients with reactive airway disease.

RECENT FINDINGS

Although prescribed for their anti-inflammatory effects (predominantly for pulmonary disease and less often for laryngeal conditions), corticosteroid inhalers can cause laryngeal inflammation. This may relate to chemical irritation from the inhaler itself as well as fungal inflammation related to opportunistic candidiasis that may accompany inhaler use. Patients who suffer from dysphonia because of inhaler use may improve if switched to another inhaler. Studies suggest that ciclesonide metered-dose inhaler may have less oropharyngeal deposition and therefore be associated with reduced oropharyngeal candidiasis and dysphonia compared with other inhaled corticosteroids.

SUMMARY

Corticosteroid inhalers are a common cause of dysphonia and their use should be investigated in any patient with laryngeal complaints.

Budding off: bringing functional genomics to Candida albicans

Candida species are the most prevalent human fungal pathogens, with Candida albicans being the most clinically relevant species. Candida albicans resides as a commensal of the human gastrointestinal tract but is a frequent cause of opportunistic mucosal and systemic infections. Investigation of C. albicans virulence has traditionally relied on candidate gene approaches, but recent advances in functional genomics have now facilitated global, unbiased studies of gene function. Such studies include comparative genomics (both between and within Candida species), analysis of total RNA expression, and regulation and delineation of protein-DNA interactions. Additionally, large collections of mutant strains have begun to aid systematic screening of clinically relevant phenotypes. Here, we will highlight the development of functional genomics in C. albicans and discuss the use of these approaches to addressing both commensalism and pathogenesis in this species.

Rapid formation of Aspergillus mycetoma in a patient receiving corticosteroid treatment. Serial radiographic observation over two months

This study presents the case of rapidly progressing pulmonary aspergillosis in a 47-year-old woman who had healed cavitations of pulmonary tuberculosis in the right upper lobe. She had been treated for pulmonary tuberculosis seven years prior to admission. The initial manifestations of the disease on admission included cough, dyspnea, hemoptysis, pulmonary infiltrate, and renal failure. As anti-myeloperoxidase anti-neutrophil cytoplasmic antibodies (MPO-ANCA) were positive, she was diagnosed with ANCA-associated vasculitis and treated with corticosteroids. This treatment resulted in remission of the vasculitis. However, she developed new pulmonary symptoms and an enlarged cavitary lesion associated with the rapid formation of a fungal, ball-shaped shadow that was serially observed by radiological analysis. Pulmonary resection was finally performed because of acute progressive respiratory failure due to massive recurrent hemoptysis. A subsequent pathological analysis revealed a mass of hyphae with acute-angle branching, features consistent with Aspergillus, within the cavitary lesion, and she was diagnosed with pulmonary aspergillosis. The rapid development of pulmonary aspergillosis associated with the formation of an Aspergillus mycetoma should be attributed to the loss of normal immune mechanisms due to immunosuppressive treatment.

Side effects with inhaled corticosteroids: the physician's perception

The National Asthma Education and Prevention Program 1997 guidelines and 2002 update provide an overview of potential local and systemic side effects associated with inhaled corticosteroids (ICS) and suggest ways of minimizing the risk of these side effects occurring. Despite the guidelines and extensive clinical experience of the safe use of ICS, a significant number of physicians retain concerns regarding side effects. Local side effects may lead to patients discontinuing therapy, with or without the knowledge of their physicians. In particular, concerns regarding systemic side effects, such as growth retardation in children and osteoporosis, remain relatively widespread. Pharmacokinetic studies reveal that different ICS compounds and formulations result in different degrees of systemic bioavailability, indicating possible differences in their potential to cause systemic side effects. However, clinical studies that can be used to differentiate between ICS formulations are generally lacking. Consequently, there is a need to continue to further our understanding of side effects with ICS, with the aim of identifying formulations, devices, and doses with an optimal risk/benefit ratio. The introduction of new agents with potentially improved safety profiles may reassure physicians and patients as to the relative benefits of ICS therapy in asthma.

Local oropharyngeal side effects of inhaled corticosteroids in patients with asthma

The widespread use of inhaled corticosteroids (ICS) for the treatment of persistent asthma, although highly effective, may be associated with both systemic and local side effects. Systemic side effects of ICS have been extensively studied. In contrast, relatively few studies have been performed to specifically evaluate local side effects of ICS. These local side effects--including oropharyngeal candidiasis, dysphonia, pharyngitis, and cough--are generally viewed as minor complications of therapy. However, they can be clinically significant, affect patient quality of life, hinder compliance with therapy, and mask symptoms of more serious disease. Local side effects result from deposition of an active ICS in the oropharynx during administration of the drug. Numerous factors can influence the proportion of an inhaled dose that is deposited in the oropharyngeal cavity, including the ICS formulation, type of delivery system, and patient compliance with administration instructions. Therefore, the incidence of local side effects can vary widely. The goal in developing a new ICS is to include key pharmacologic characteristics that reduce oropharyngeal exposure to active drug while maintaining efficacy comparable with currently available ICS.

Novel modes of antifungal drug administration

Administration of antifungals by routes other than that for which the agent was designed or approved have been utilised in attempts to provide directed therapy, reduce adverse effects and improve drug penetration into selected infection sites, such as the central nervous system, lungs and peritoneum. The most widely investigated agent utilising a novel method of drug delivery is amphotericin B. Dose forms for this agent include topicals (aerosol, nasal spray, irrigations, pastes, absorbable sponges, impregnated bone cement and gelatin), oral dosage forms (solutions, suspensions, tablets and so on) and ophthalmic preparations (drops, ointments and injections). Amphotericin B has been administered by routes such as oral, endobronchial, intrathecal, intracisternal, intra-articular, intraperitoneal, ophthalmic and as an antibiotic 'line lock'. Nystatin has been administered as an aerosol, percutaneous paste and bladder washes. Azoles, such as miconazole, fluconazole, ketoconazole and posaconazole, have been administered by novel methods but to a lesser degree. Most of these reports involve miconazole. The dose forms and routes of administration for azoles have included irrigants (bladder, joint), ophthalmic preparations (eye drops, intraocular injections, ointments), impregnated bone cement, endobronchial and intrathecal administration. Finally, both methylene blue (bladder washes) and flucytosine (peritoneal lavage, ophthalmic eye drops) have also been employed. Adequate evaluations of both the safety and efficacy of these therapies are most often hindered by prior or concomitant antifungal therapies, comorbidities and the lack of controlled clinical trials. In addition, the availability of newer treatment options, which demonstrate significant improvement in drug distribution and treatment-related adverse effects make many such novel modes of administration less practical or necessary. In contrast, the inhalation of antifungal aerosols, such as amphotericin B, is rapidly becoming a viable prophylactic option.

Oral candidiasis associated with inhaled corticosteroid use: comparison of fluticasone and beclomethasone

BACKGROUND

Inhaled steroids such as fluticasone propionate and beclomethasone dipropionate play a central role in the treatment of bronchial asthma. Fluticasone exhibits excellent clinical effectiveness; however, oral adverse effects can occur.

OBJECTIVE

To compare the frequency of oral candidiasis in asthmatic patients treated with fluticasone and beclomethasone, to evaluate the effect of gargling with amphotericin B, and to measure the inhalation flow rate on candidiasis.

METHODS

The study consisted of 143 asthmatic patients who were treated with inhaled steroids, 11 asthmatic patients not treated with inhaled steroids, and 86 healthy volunteers. Quantitative fungal culture was performed by aseptically obtaining a retropharyngeal wall swab from these patients. Patients with positive results were treated with gargling using a 1:50 dilution amphotericin B solution. In asthmatic patients treated with fluticasone, the inhalation flow rate was measured using an inspiratory flow meter.

RESULTS

The amount of Candida spp. was significantly greater in asthmatic patients taking inhaled steroids compared with those who were not. It was also significantly greater in patients with oral symptoms than asymptomatic patients and significantly greater in asthmatic patients treated with fluticasone than in those treated with beclomethasone. Although the presence of Candida did not correlate with the inhaled dose of beclomethasone, it did increase with the dose of fluticasone. Gargling with amphotericin B was effective in most asthmatic patients with candidiasis. Candidiasis was not due to inappropriate flow rates during inhalation of steroids.

CONCLUSIONS

Fungal culture of a retropharyngeal wall swab may be useful for predicting the risk of developing oral candidiasis in asthmatic patients treated with inhaled steroids. The amount of isolated Candida was significantly greater in asthmatic patients treated with fluticasone than in those treated with beclomethasone. Attention to dosage is required as the amount of Candida increased with dose of fluticasone. Gargling with a 1:50 dilution of amphotericin B is effective in treating oral candidiasis of asthmatic patients treated with inhaled steroids.