Review of Fluconazole Treatment and Prophylaxis for Invasive Candidiasis in Neonates

New Peptide Based Fluconazole Conjugates with Expanded Molecular Targets

Infections of Candida spp. etiology are frequently treated with azole drugs. Among azoles, the most widely used in the clinical scenario remains fluconazole (FLC). Promising results in treatment of dangerous, systemic Candida infections demonstrate the advantages of combined therapies carried out with combinations of at least two different antifungal agents. Here, we report five conjugates composed of covalently linked FLC and cell penetrating or antimicrobial peptide: TP10-7-NH₂, TP10-NH₂, LFcinB(2-11)-NH₂, LFcinB[Nle^1,11]-NH₂, and HLopt2-NH₂, with aspects of design, chemical synthesis and their biological activities. Two of these compounds, namely FLCpOH-TP10-NH₂ and FLCpOH-TP10-7-NH₂, exhibit high activity against reference strains and fluconazole-resistant clinical isolates of C. albicans, including strains overproducing drug transporters. Moreover, both of them demonstrate higher fungicidal effects compared to fluconazole. Analysis performed with fluorescence and scanning electron microscopy as well as flow cytometry indicated the cell membrane as a molecular target of synthesized conjugates. An important advantage of FLCpOH-TP10-NH₂ and FLCpOH-TP10-7-NH₂ is their low cytotoxicity. The IC₉₀ value for the human cells after 72 h treatment was comparable to the MIC₅₀ value after 24 h treatment for most strains of C. albicans. In reported conjugates, FLC was linked to the peptide by its hydroxyl group. It is worth noting that conjugation of FLC by the nitrogen atom of the triazole ring led to practically inactive compounds. Two compounds produced by us and reported herein appear to be potential candidates for novel antifungal agents.

Successful fluconazole combined with caspofungin treatment of candida bloodstream infection in preterm infant: A case report

RATIONALE

Candida bloodstream infection continues to be a significant cause of mortality in premature infants. Amphotericin B has been recommended as the primary treatment; however, its use is limited due to drug-induced nephrotoxicity and amphotericin B-resistant candidemia.

PATIENT CONCERNS

The gestational age was 29 (+6) weeks, and birth weight was 1760 g.

DIAGNOSIS

The infant was diagnosed with Candida parapsilosis bloodstream infection.

INTERVENTIONS

Fluconazole, 12 mg/kg/day, combined with caspofungin (loading dose 3 mg/kg, at a maintenance dose of 2 mg/kg every 24 h) therapy was administered to premature infant with Candida bloodstream infection. When fluconazole or caspofungin was used to treat Candida bloodstream infection in preterm infants, the blood cultures of the infant remained positive for Candida parapsilosis.

OUTCOMES

All persistent candidemia resolved on fluconazole combined with caspofungin therapy. There were no adverse effects, hepatotoxicity, nephrotoxicity, anemia, or thrombocytopenia.

LESSONS

Fluconazole combined with caspofungin successfully treated Candida bloodstream infection in premature infants at 29 + 6 weeks' gestational age, but large-scale clinical trials are required.

Identification and Antifungal Susceptibility Analysis of Stephanoascus ciferrii Complex Species Isolated From Patients With Chronic Suppurative Otitis Media

Background

Stephanoascus ciferrii is a heterothallic ascomycetous yeast-like fungus. Recently, the concept of S. ciferrii complex has been proposed and it consists of S. ciferrii, Candida allociferrii, and Candida mucifera. We aimed to identify 32 strains of S. ciferrii complex isolated from patients with chronic suppurative otitis media (CSOM) at the species level and analyze the morphology and antifungal susceptibility profiles of the three species.

Method

The sequencing of the internal transcribed spacer (ITS) region and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to identify S. ciferrii complex species. The SARAMIS software was used for cluster analysis of the mass spectra. All the strains were cultured on Sabouraud dextrose agar (SDA) and CHROM plates for 7 days. In the meantime, colonies of the 32 strains went through Gram staining. The Sensititre YeastOne YO10 colorimetric panel was used for the antifungal susceptibility analysis.

Results

There were 10 strains of C. allociferrii (31.25%), six strains of C. mucifera (18.75%), and 16 strains of S. ciferrii (50%) in the 32 strains of S. ciferrii complex according to the sequencing of the ITS region. MALDI-TOF MS could identify S. ciferrii but showed no results for C. allociferrii and C. mucifera. The cluster analysis of the mass spectra by SARAMIS indicated that the MALDI-TOF MS could distinguish the three species. The morphology characteristics of the three species were similar. As for antifungal susceptibility, S. ciferrii and C. mucifera tended to have high fluconazole MICs compared with C. allociferrii. C. mucifera and C. allociferrii had relatively low flucytosine MICs while S. ciferrii owned high flucytosine MICs. Besides, C. mucifera tended to have a higher MIC value than S. ciferrii for amphotericin B and C. allociferrii for anidulafungin, micafungin, and caspofungin.

Conclusion

The antifungal susceptibility profiles of the three species of S. ciferrii complex had their own characteristics. Besides, more mass spectra of C. allociferrii and C. mucifera are needed to construct the reference database for S. ciferrii complex species, enabling MALDI-TOF MS to identify S. ciferrii complex at species level.