Identification and assessment of antifungal susceptibility of Candida species based on bronchoalveolar lavage in immunocompromised and critically ill patients.

Background and Objectives: The presence of fungi in the respiratory tract as mycobiome, particularly Candida species (spp.), remains a serious problem due to increasing numbers of immunocompromised patients. The confirmed reliable existence of these pathogens due to frequent colonization is essential. This investigation aimed to recognize Candida spp. among isolates from bronchoalveolar lavage of immunocompromised and critically ill patients and to evaluate their susceptibility to antimycotic drugs. Materials and Methods: Bronchoalveolar lavage fluid was collected from 161 hospitalized patients presenting with suspected respiratory fungal infection /colonization. The specimens were examined by standard molecular and mycological assays. Candida spp. were recognized with sequence assessment of the D1-D2 section of the large subunit ribosomal DNA. The susceptibility of Candida isolates to common antimycotic drugs was distinguished by standard broth microdilution. Results: Seventy-one clinical isolates of Candida spp. were recognized. Candida albicans was the most frequent, followed by C. glabrata, C. krusei (Pichia kudriavzevii), C. dubliniensis, C. parapsilosis, and C. tropicalis. We found 5.1% of C. albicans isolates and 8% of C. glabrata isolates to show resistance to fluconazole. The whole of the Candida spp. were sensitive to amphotericin B and caspofungin. Conclusion: This study demonstrated that C. albicans and C. glabrata are the most common isolates of bronchoalveolar lavage fluid in patients, and the drug susceptibility screening confirmed that amphotericin B and caspofungin are effective against Candida spp. but some C. glabrata and C. albicans isolates showed resistance to fluconazole.

Low prevalence of antifungal resistant Candida africana, in the C. albicans complex causing vulvovaginal candidiasis.

The Candida (C.) albicans complex includes C. albicans, C. dubliniensis, C. stellatoidea, and C. africana, with the last mentioned as an important emerging agent of vulvovaginal candidiasis (VVC). The aim of the study was to identify C. africana and C. dubliniensis and assess their drug susceptibility in vaginitis. One-hundred Candida isolates of the C. albicans complex from women diagnosed with vaginitis and from vaginal samples in the culture collection of a medical mycology laboratory were examined. Species of the C. albicans complex were identified with conventional and molecular methods using polymerase chain reaction (PCR) for amplification and sequencing of the internal transcribed spacer (ITS) region, PCR for partial amplification of hyphal wall protein 1 (HWP1) gene and duplex PCR. The effects of antifungal drugs were evaluated according to standard broth microdilution protocols. Ninety-seven C. albicans (97%) and three C. africana (3%) isolates were identified. Results of susceptibility testing revealed one isolate of C. africana to be resistant to both clotrimazole and fluconazole, and one showed reduced susceptibility to itraconazole. Identification of Candida species especially C. africana in vaginitis is crucial, there are varying levels of resistance to antifungal drugs.

Effect of 2-Phenylethanol as Antifungal Agent and Common Antifungals (Amphotericin B, Fluconazole, and Itraconazole) on Candida Species Isolated from Chronic and Recurrent Cases of Candidal Vulvovaginitis.

The antifungal effects of 2-phenylethanol are clearly visible through its intervention in Candida morphogenesis. Chronic and recurrent vulvovaginitis, however, does not respond to this standard experimental therapy; therefore, the study presented in this article investigated the effect of common antifungal drugs (amphotericin B [AMB], fluconazole [FLU], and itraconazole [ITC]), in combination with 2-phenylethanol, on the Candida species isolated from cases of chronic and recurrent vulvovaginitis, thereby allowing the recommendation of a more appropriate treatment option. Forty isolates from patients with chronic and recurrent vaginal candidiasis were investigated in this experimental study. The specimens were examined by direct microscopy, culturing, and PCR to identify the species. The antifungal effects of 2-phenylethanol and conventional drugs, both alone and in combination, were determined in duplicate. Finally, the findings were analyzed. In this study, 40 strains of Candida species were identified, whose agents were Candida albicans (95%) and Candida africana (5%). After 48 h, the minimum inhibitory concentration (MIC) range of the 2-phenylethanol was 800-3,200 µg/mL. Also, in the final study on the MIC levels of common antifungal drugs, AMB (0.42 µg/mL) had the lowest MIC, FLU (40.51 µg/mL) had the highest MIC, and the combination of ITC and 2-phenylethanol had the lowest fractional inhibitory concentration index (FICI) of any of the combinations (FICI range, 0.26-1.03). Combining FLU and ITC with 2-phenylethanol can effectively increase their antifungal effect.

Molecular Identification and Antifungal Susceptibility Pattern of Non-albicans Candida Species Isolated from Vulvovaginal Candidiasis

Background: Vulvovaginal candidiasis (VVC) is an important health problem caused by Candida spp. The aim of this study was molecular identification, phylogenetic analysis, and evaluation of antifungal susceptibility of non-albicans Candida isolates from VVC. Methods: Vaginal secretion samples were collected from 550 vaginitis patients at Sayyad Shirazi Medical and Educational Center of Gorgan (Golestan Province, Iran) from May to October 2015. Samples were analyzed using conventional mycological and molecular approaches. Clinical isolates were analyzed with specific PCR using CGL primers, and the internal transcribed spacer region and the D1-D2 domain of the large-subunit rRNA gene were amplified and sequenced. Susceptibility to amphotericin B, fluconazole, itraconazole, and clotrimazole was determined by the guidelines of the Clinical and Laboratory Standard Institute. Results: In total, 35 non-albicans Candida isolates were identified from VVC patients. The isolates included 27 strains of Candida glabrata (77.1%), 5 Candida krusei (Pichia kudriavzevii; 14.3%), 2 Candida kefyr (Kluyveromyces marxianus; 5.7%), and 1 Candida lusitaniae (Clavispora lusitaniae; 2.9%). The fungicides itraconazole and amphotericin B were effective against all species. One isolate of C. glabrata showed resistance to fluconazole and clotrimazole, and 26 isolates of C. glabrata indicated dose-dependent susceptibility to fluconazole. C. lusitaniae was susceptible in a dose-dependent manner to fluconazole and resistant to clotrimazole. Conclusion: Non-albicans Candida spp. are common agents of vulvovaginitis, and C. glabrata is the most common species in the tested patients.

The first report of onychomycosis caused by Cryptococcus friedmannii (Naganishia friedmannii) a basidiomycetous yeast.

Yeasts are common etiologic agents of onychomycosis. This study reported a case of onychomycosis due to Cryptococcus friedmannii (Naganishia friedmannii). This yeast was isolated of the right great toenail of 57-year-old man. Microscopic examination of nail scrapings showed budding cells with thin capsule. Sequence analyzes of the internal transcribed spacer regions was closely related to Cryptococcus friedmannii. The results of susceptibility testing showed the Cryptococcus friedmannii to be sensitive to fluconazole, itraconazole and amphotericin B.

Imidazolylchromanones containing alkyl side chain as lanosterol 14α-demethylase inhibitors: synthesis, antifungal activity and docking study.

Previously, 2-alkylchromans have been introduced as non-azole inhibitors of 14α-demethylase. Accordingly, we incorporated imidazole ring on the 3-position of 2-alkylchromanones to design new inhibitors of 14α-demethylase and potential antifungal agents. Thus, a series of 2-alkyl-3-imidazolylchromanones were synthesized starting from 2-hydroxyphenacyl bromide. The trans-configuration of compounds was confirmed by NMR-spectroscopy. The antifungal activity of title compounds were evaluated against different fungi in comparison with fluconazole and miconazole. trans-2-(1-Pentyl)-3-imidazolylchroman-4-one (4d) showed the most potent activity against yeasts comparable to fluconazole. The experimental data based on (1)H NMR spectroscopy revealed that 2-alkyl side chain and 3-imidazolyl moiety in compound 4d exist predominantly in the di-equatorial conformation. While docking study with 14α-demethylase demonstrated that the di-axial form of compound 4d can be considered as active conformation.

Synthesis and antifungal activity of 1-[(2-benzyloxy)phenyl]-2-(azol-1-yl)ethanone derivatives: exploring the scaffold flexibility.

Based on the N-(phenethyl)azole backbone of azole antifungals, we designed 1-[(2-benzyloxy)phenyl]-2-(azol-1-yl)ethanone derivatives 2 and 3, containing benzyloxyphenyl scaffold of croconazole. Also these compounds can be considered as flexible analogs, resulted from C2-C3 disconnection of 3'-chloro-3-imidazolylflavanone 1, recently described as antifungal agent. Thus, in this report, we describe the synthesis of 1-[(2-benzyloxy)phenyl]-2-(azol-1-yl)ethanone derivatives 2 and 3 and their biological evaluation against different pathogenic fungi. By comparing the antifungal activity profile of flexible compounds 2 and 3 with that of rigid analog 1, it can be inferred that lower susceptibilities (higher minimum inhibitory concentrations) were observed with flexible compounds. However, among the synthesized compounds, 1-[2-(2,4-dichlorobenzyloxy)phenyl]-2-(1H-imidazol-1-yl)ethanone hydrochloride (2g) showed comparable or more potent antifungal activity in comparison with fluconazole as a standard drug.