Drug-resistant oral candidiasis in patients with HIV infection: a systematic review and meta-analysis

BACKGROUND

Oral candidiasis (OC) is a prevalent opportunistic infection in patients with human immunodeficiency virus (HIV) infection. The increasing resistance to antifungal agents in HIV-positive individuals suffering from OC raised concerns. Thus, this study aimed to investigate the prevalence of drug-resistant OC in HIV-positive patients.

METHODS

Pubmed, Web of Science, Scopus, and Embase databases were systematically searched for eligible articles up to November 30, 2023. Studies reporting resistance to antifungal agents in Candida species isolated from HIV-positive patients with OC were included. Baseline characteristics, clinical features, isolated Candida species, and antifungal resistance were independently extracted by two reviewers. The pooled prevalence with a 95% confidence interval (CI) was calculated using the random effect model or fixed effect model.

RESULTS

Out of the 1942 records, 25 studies consisting of 2564 Candida species entered the meta-analysis. The pooled prevalence of resistance to the antifungal agents was as follows: ketoconazole (25.5%, 95% CI: 15.1-35.8%), fluconazole (24.8%, 95% CI: 17.4-32.1%), 5-Flucytosine (22.9%, 95% CI: -13.7-59.6%), itraconazole (20.0%, 95% CI: 10.0-26.0%), voriconazole (20.0%, 95% CI: 1.9-38.0%), miconazole (15.0%, 95% CI: 5.1-26.0%), clotrimazole (13.4%, 95% CI: 2.3-24.5%), nystatin (4.9%, 95% CI: -0.05-10.3%), amphotericin B (2.9%, 95% CI: 0.5-5.3%), and caspofungin (0.1%, 95% CI: -0.3-0.6%). Furthermore, there were high heterogeneities among almost all included studies regarding the resistance to different antifungal agents (I2 > 50.00%, P < 0.01), except for caspofungin (I2 = 0.00%, P = 0.65).

CONCLUSIONS

Our research revealed that a significant number of Candida species found in HIV-positive patients with OC were resistant to azoles and 5-fluocytosine. However, most of the isolates were susceptible to nystatin, amphotericin B, and caspofungin. This suggests that initial treatments for OC, such as azoles, may not be effective. In such cases, healthcare providers may need to consider prescribing alternative treatments like polyenes and caspofungin.

REGISTRATION

The study protocol was registered in the International Prospective Register of Systematic Reviews as PROSPERO (Number: CRD42024497963).

Development and Characterization of New Miconazole-Based Microemulsions for Buccal Delivery by Implementing a Full Factorial Design Modeling

This research aimed to develop miconazole-based microemulsions using oleic acid as a natural lipophilic phase and a stabilizer mixture comprising Tween 20 and PEG 400 to solubilize miconazole as an antifungal agent known for its activity in oral candidiasis and to improve its bioavailability. The formulation and preparation process was combined with a mathematical approach using a 23-full factorial plan. Fluid and gel-like microemulsions were obtained and analyzed considering pH, conductivity, and refractive index, followed by extensive analyses focused on droplet size, zeta potential, rheological behavior, and goniometry. In vitro release tests were performed to assess their biopharmaceutical characteristics. Independent variables coded X1-Oleic acid (%, w/w), X2-Tween 20 (%, w/w), and X3-PEG 400 (%, w/w) were analyzed in relationship with three main outputs like mean droplet size, work of adhesion, and diffusion coefficient by combining statistical tools with response surface methodology. The microemulsion containing miconazole base-2%, oleic acid-5%, Tween 20-40%, PEG 400-20%, and water-33% exhibited a mean droplet size of 119.6 nm, a work of adhesion of 71.98 mN/m, a diffusion coefficient of 2.11·10-5 cm2/s, and together with remarked attributes of two gel-like systems formulated with higher oil concentrations, modeled the final optimization step of microemulsions as potential systems for buccal delivery.

A 3-year study of Candida infections among patients with malignancy: etiologic agents and antifungal susceptibility profile

Objective

Opportunistic fungal infections by Candida species arise among cancer patients due to the weakened immune system following extensive chemotherapy. Prophylaxis with antifungal agents have developed the resistance of Candida spp. to antifungals. Accurate identification of yeasts and susceptibility patterns are main concerns that can directly effect on the treatment of patients.

Methods

Over a period of three years, 325 cancer patients suspected to Candida infections were included in the current investigation. The clinical isolates were molecularly identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). All strains, were examined for in vitro susceptibility to the amphotericin B, itraconazole, fluconazole, and anidulafungin according to the CLSI M27 document.

Results

Seventy-four cancer patients had Candida infections (22.7%). Candida albicans was the most common species (83.8%). Antifungal susceptibility results indicated that 100% of the Candida isolates were sensitive to amphotericin B; however, 17.6%, 9.4%, and 5.4% of clinical isolates were resistant to anidulafungin, fluconazole, and itraconazole, respectively.

Conclusion

The findings of the present work shows a warning increase in resistance to echinocandins. Since all fluconazole resistance isolates were obtained from candidemia, we recommend amphotericin B as the first line therapy for this potentially fatal infection.

Anti-biofilm properties of eucalyptol in combination with antifungals against Candida albicans isolates in patients with hematological malignancy

Oral candidiasis is a fungal infection caused mainly by Candida albicans and it is a major problem among hematologic malignancy patients. Biofilm formation is an attributable factor to both virulence and drug resistance of Candida species. The aim of the study was to evaluate the biofilm-producing ability of oral C. albicans isolates and to evaluate the inhibitory activity of eucalyptol on Candida biofilm, alone and in combination with antifungal agents. Samples were collected from the oral cavity of 106 patients with hematologic malignancy. The isolated yeasts were identified by PCR-sequencing. Then C. albicans isolates were analyzed for their biofilm-producing ability by crystal violet staining and MTT assay. The minimum biofilm inhibition concentrations (MBIC) of eucalyptol, amphotericin B, itraconazole, and nystatin and the in vitro interaction of eucalyptol with these drugs were tested according to CLSI-M-27-A3 protocol and checkerboard methods, respectively. From 106 patients, 50 (47.2%) were confirmed for oral candidiasis [mean ± SD age 39 ± 14 years; female 31 (62%) and male 19 (38%)]. C. albicans was isolated from 40 of 50 (80%) patients. From 40 C. albicans isolates, 24 (60%) and 16 (40%) were moderate and weak biofilm producer, respectively. The geometric mean MBIC of amphotericin B, itraconazole, nystatin and eucalyptol were 3.93 µg/mL, 12.55 µg/mL, 0.75 µg/mL and 798 µg/mL, respectively. Eucalyptol interacted synergistically with amphotericin B, itraconazole and nystatin against 12.5, 10, and 22.5% of isolates, respectively. Eucalyptol demonstrated promising activity against biofilm of C. albicans when tested alone or combined with antifungal drugs.

Design, Synthesis, and In Vitro and In Vivo Evaluation of Novel Fluconazole-Based Compounds with Promising Antifungal Activities

Demand has arisen for developing new azole antifungal agents with the growth of the resistant rate of infective fungal species to current azole antifungals in recent years. Accordingly, the present study reports the synthesis of novel fluconazole (FLC) analogues bearing urea functionality that led to discovering new azole agents with promising antifungal activities. In particular, compounds 8b and 8c displayed broad-spectrum activity and superior in vitro antifungal capabilities compared to the standard drug FLC against sensitive and resistant Candida albicans (C. albicans). The highly active compounds 8b and 8c had potent antibiofilm properties against FLC-resistant C. albicans species. Additionally, these compounds exhibited very low toxicity for three mammalian cell lines and human red blood cells. Time-kill studies revealed that our synthesized compounds displayed a fungicidal mechanism toward fungal growth. Furthermore, a density functional theory (DFT) calculation, additional docking, and independent gradient model (IGM) studies were performed to analyze their structure-activity relationship (SAR) and to assess the molecular interactions in the related target protein. Finally, in vivo results represented a significant reduction in the tissue fungal burden and improvements in the survival rate in a mice model of systemic candidiasis along with in vitro and in silico studies, demonstrating the therapeutic efficiency of compounds 8b and 8c as novel leads for candidiasis drug discovery.

Oral Candidal Colonization in Patients with Different Prosthetic Appliances

Oral infections caused by Candida species are becoming more common, which may be related to an increase in the number of immunologically compromised patients as well as favorable conditions in the oral cavity that often include removable prosthetic appliances. The purpose of this study was to determine the presence of a particular Candida species in patients with PMMA and Cr-Co prosthetic appliances, as well as the salivary flow rate, and oral signs and symptoms. This investigation included a total of 120 subjects with different kinds of removable dentures. A sample of concentrated oral rinse was collected from all subjects in order to detect Candida colonization and identify the Candida species, a quantum of salivation was measured, and subjects were examined clinically. Candida spp. was predominant among the subjects who were denture wearers (p < 0.0001). In all subjects, the most frequently detected species was C.albicans. A statistically significant difference was found between the prevalence of C.albicans (p < 0.001) and C.krusei (p < 0.001) in denture wearers. Subjects with PMMA-based removable prosthetic appliances mostly demonstrated a significant decrease in salivation (p < 0.001), an increase in burning sensations (p < 0.001), and dry mouth (p < 0.001) compared to the subjects who wore partial dentures with Co–Cr metallic frameworks. Red oral lesions were more frequently found among the subjects with partial dentures with Co–Cr metallic frameworks (p < 0.001). Regardless of the material used for the denture, patients must be regularly checked by their dentists in order to prevent the development of oral lesions.

Does Prolonged Exposure of Environmental Fungi to Ultraviolet Irradiation Change the Pattern of Drug Resistance?

Background: The pathogenic and opportunistic fungal species cause life-threatening infections in immunocompromised patients. The ultraviolet (UV) germicidal irradiation is a well-known method for inactivating a significant number of microorganisms and has wide application for sterilization. Objectives: This study aimed to investigate the effect of ultraviolet C (UV-C) irradiation on the antifungal susceptibility pattern of some filamentous fungi. Methods: The effect of UV-C on the antifungal susceptibility pattern of itraconazole, voriconazole, fluconazole, and amphotericin B against filamentous fungi was examined. Changes in the morphological features of resistant strains following UV-C irradiation were also evaluated using scanning electron microscopy. Results: The results revealed a significant decrease in the number of the surviving spores of strains with the prolongation of UV-C irradiation (0 - 10 to 20 min; P < 0.05). Concerning the morphology of resistant Aspergillus spp., the results of scanning electron microscopy showed a significant increase in the length of irradiated hyphae compared to the non-irradiated hyphae (P < 0.05). In addition, colony count showed a significant decrease (P < 0.05). The findings revealed that UV-C radiation exposure could alter the antifungal susceptibility pattern of Aspergillus spp., such as increasing the minimum inhibitory concentration. Conclusions: Aspergillus spp. can cause systemic infections among lab technicians exposed to different doses of radiation. Moreover, this increase in susceptibility pattern can directly affect the duration of treatment.