Conventional Antifungals for Invasive Infections Delivered by Unconventional Methods; Aerosols, Irrigants, Directed Injections and Impregnated Cement

Emphysematous pyelonephritis due to Candida albicans in a diabetic patient: A case report

Emphysematous pyelonephritis is an infection of the kidney tissue that is necrotizing and gas-producing and primarily affects individuals with diabetes mellitus. We have reported a 67-year-old female with a history of diabetes mellitus and prior urological procedures who developed emphysematous pyelonephritis due to Candida albicans. She was treated with systemic fluconazole and underwent other urological interventions as necessary. But due to persistent fever, irrigation of amphotericin B via nephrostomy was applied for three days after which her fever resolved. She finally recovered and was discharged in a healthy state. This case presentation underscores the complexity of managing fungal pyelonephritis.

Augmented glycerosomes as a promising approach against fungal ear infection: Optimization and microbiological, ex vivo and in vivo assessments

In the current study, voriconazole (VCZ) augmented glycerosomes were optimized for topical otomycosis management according to a 23 factorial design, employing a thin film hydration method. By optimizing Glycerol volume, limonene: VCZ ratio and Span® 60: soybean phosphatidyl choline (PC) ratio, glycerosomes with maximum percentage entrapment efficiency (%EE) and zeta potential (ZP) and minimum vesicle size (VS) and polydispersity index (PDI) were to be obtained. An optimal augmented glycerosomal formula (OAG) that contained 10 mg VCZ, 150 mg PC, and 3 mL glycerol, comprising 2.5: and 0.92:1 ratios of the latter two independent variables, was proposed via numerical optimization. OAG exhibited high %EE and ZP values and acceptable low values for VS and PDI (84.3 ± 2.0 %, -38.8 ± 1.8 mV, 191.0 ± 1.1 nm, and 0.192 ± 0.01, respectively). Extensive in vitro testing of OAG revealed the entrapment of VCZ within OAG, biphasic in vitro release profile, stability for up to 3 months at 2-8 °C and spherical morphology of OAG with VS like that obtained via zetasizer. OAG demonstrated higher permeated amounts of VCZ and flux values than VCZ suspension, leading to an enhancement ratio of 2.56 in the ex vivo permeation study. The deeper penetration ability of OAG demonstrated by Confocal Laser Scanning Microscopy and its superior in vitro antifungal activity confirmed the validity of the ex vivo study. Also, the histopathological study confirmed the safety of OAG for topical use, suggesting that VCZ OAG was a promising topical antimycotic formula.

New and emerging roles for inhalational and direct antifungal drug delivery approaches for treatment of invasive fungal infections

INTRODUCTION

The rising prevalence of difficult-to-treat, deep-seated invasive fungal diseases (IFD) has led to high mortality. Currently available antifungal treatments, administered predominantly orally or intravenously, may not sufficiently penetrate certain body sites, and/or are associated with systemic toxicity. Little is known about how to position alternative administration approaches such as inhalational and direct drug delivery routes.

AREAS COVERED

This review provides an updated overview of unconventional drug delivery strategies for managing IFD, focusing on inhalational (to target the lungs) and direct delivery methods to the central nervous system, bone/joint, and eyes. Novel compounds (e.g. opelconazole) and existing antifungals with innovative drug delivery systems currently undergoing clinical trials and/or used off-label in the clinical setting are discussed.

EXPERT OPINION

For both inhalational agents and direct delivery approaches, there are similar challenges that include the absence of: approved formulations for specific administration routes, delivery vehicles that are simple and safe to use whilst maintaining potency and efficiency of delivery, animal models suitable for investigating pharmacokinetic/pharmacodynamic profiles of inhaled antifungals, and consensus on the composite endpoints and intervals for of follow-up in clinical trials. To meet these challenges, cooperation of all stakeholders in drug development and regulation is required.

Propensity of Candida spp. prosthetic joint infection clinical isolates to form aggregates in synovial fluid and the clinical ramifications

BACKGROUND

Bacterial aggregation has been shown to occur in synovial fluid which are resistant to high concentrations of antibiotics. Yet the propensity of Candida spp. to form aggregates is unknown.

OBJECTIVE

To assess the ability of numerous Candida spp. to form synovial fluid aggregates and the clinical ramifications of the aggregates.

METHODS

Nine different Candidal prosthetic joint infection clinical isolates were evaluated for their ability to form aggregates at static and dynamic conditions and their resistance to high concentrations of amphotericin. Furthermore, the ability of tissue plasminogen activator (TPA) to disrupt the aggregates and enhance amphotericin activity was assessed.

RESULTS

The results show that all species of Candida spp. evaluated formed aggregates in synovial fluid under dynamic conditions that were resistant to amphotericin. Yet no aggregates formed in tryptic soy broth under any conditions or in synovial fluid under static conditions. As well, when TPA was combined with amphotericin there was a statistically significant decrease (p < .005) in the amount of colony forming units per mL for all Candidal species evaluated. Interestingly, for Candida krusei there was no colony forming units observed after exposure to TPA and amphotericin.

CONCLUSION

Our findings suggest that Candidal species form synovial fluid aggregates that are resistant to high dose amphotericin similar to those that occur with bacteria. However, the varying ability of the different Candida spp. to form hyphae and pseudohyphae compared to yeast cells may have direct impacts on the hardiness of the aggregates and thereby have clinical ramifications with respect to treatment durations.

Relapsing Aspergillus otomycosis despite prolonged systemic antifungal therapy and resolution after topical voriconazole administration: A case report

We report a case of intractable Aspergillus otomycosis with multiple relapses despite conventional topical and systemic antifungal treatment, and adjunctive usage of hyperbaric oxygen therapy. Of note, otomycosis relapsed even after six months of continuous systemic antifungal treatment with therapeutic drug levels and without treatment interruption; and only resolved after application of topical voriconazole. (max. 75 words).

Resistance profiles to antifungal agents in Candida albicans isolated from human oral cavities: systematic review and meta-analysis

Aim

To identify the antifungal susceptibility profile of Candida spp. isolated from the human oral cavity was assessed with meta-analyses of observational studies that collected samples from the oral cavity of human subjects.

Material and methods

Isolated Candida albicans tested by E-test®; disk diffusion test; microdilution and macrodilution; Sensititre YeastOne; and/or FungiTest. Search strategies were conducted on the MEDLINE, Embase, CINAHL, Dentistry, and Oral Sciences, Central, Scopus, and LILACS databases, and gray literature sources. Articles were initially screened by title and then their abstracts. Articles that met the conditions for inclusion were read in full, followed by data extraction. A descriptive analysis was conducted of each study, and the data were tabulated. A first meta-analysis was conducted to assess the resistance of antifungals regardless of systemic comorbidities. An additional stratified analysis was conducted by systemic comorbidity groups for the outcome “resistance” to the antifungals.

Results

When not grouping Candida albicans isolates by systemic conditions, the lowest resistance rates to the antifungals tested were observed for amphotericin B, nystatin, flucytosine, and caspofungin. In contrast, the highest resistance rates were observed for miconazole and econazole. There was a high degree of heterogeneity and low resistance in general in all analyses, except for the “several associated comorbidities” group, which had high resistance rates.

Conclusions

Clinical C. albicans isolates had low antifungal resistance.

Clinical relevance

The presence of concomitant systemic comorbidities appears to be an essential factor that should be considered when evaluating resistance to antifungals for oral isolates.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-022-04716-2.