Epidemiology, species distribution, antifungal susceptibility, and ERG11 mutations of Candida species isolated from pregnant Chinese Han women

Distribution and antifungal susceptibility pattern of Candida species from mainland China: A systematic analysis

Antifungal resistance to Candida pathogens increases morbidity and mortality of immunosuppressive patients, an emerging crisis worldwide. Understanding the Candida prevalence and antifungal susceptibility pattern is necessary to control and treat candidiasis. We aimed to systematically analyse the susceptibility profiles of Candida species published in the last ten years (December 2011 to December 2021) from mainland China. The studies were collected from PubMed, Google Scholar, and Science Direct search engines. Out of 89 included studies, a total of 44,716 Candida isolates were collected, mainly comprising C. albicans (49.36%), C. tropicalis (21.89%), C. parapsilosis (13.92%), and C. glabrata (11.37%). The lowest susceptibility was detected for azole group; fluconazole susceptibilities against C. parapsilosis, C. albicans, C. glabrata, C. tropicalis, C. guilliermondii, C. pelliculosa, and C. auris were 93.25%, 91.6%, 79.4%, 77.95%, 76%, 50%, and 0% respectively. Amphotericin B and anidulafungin were the most susceptible drugs for all Candida species. Resistance to azole was mainly linked with mutations in ERG11, ERG3, ERG4, MRR1-2, MSH-2, and PDR-1 genes. Mutation in FKS-1 and FKS-2 in C. auris and C. glabrata causing resistance to echinocandins was stated in two studies. Gaps in the studies' characteristics were detected, such as 79.77%, 47.19 %, 26.97%, 7.86%, and 4.49% studies did not mention the mortality rates, age, gender, breakpoint reference guidelines, and fungal identification method, respectively. The current study demonstrates the overall antifungal susceptibility pattern of Candida species, gaps in surveillance studies and risk-reduction strategies that could be supportive in candidiasis therapy and for the researchers in their future studies.

An Immunomodulatory Peptide Confers Protection in an Experimental Candidemia Murine Model

Fungal Candida species are commensals present in the mammalian skin and mucous membranes. Candida spp. are capable of breaching the epithelial barrier of immunocompromised patients with neutrophil and cell-mediated immune dysfunctions and can also disseminate to multiple organs through the bloodstream. Here we examined the action of innate defense regulator 1018 (IDR-1018), a 12-amino-acid-residue peptide derived from bovine bactenecin (Bac2A): IDR-1018 showed weak antifungal and antibiofilm activity against a Candida albicans laboratory strain (ATCC 10231) and a clinical isolate (CI) (MICs of 32 and 64 μg · ml-1, respectively), while 8-fold lower concentrations led to dissolution of the fungal cells from preformed biofilms. IDR-1018 at 128 μg · ml-1 was not hemolytic when tested against murine red blood cells and also has not shown a cytotoxic effect on murine monocyte RAW 264.7 and primary murine macrophage cells at the tested concentrations. IDR-1018 modulated the cytokine profile during challenge of murine bone marrow-derived macrophages with heat-killed C. albicans (HKCA) antigens by increasing monocyte chemoattractant protein 1 (MCP-1) and interleukin-10 (IL-10) levels, while suppressing tumor necrosis factor alpha (TNF-α), IL-1β, IL-6, and IL-12 levels. Mice treated with IDR-1018 at 10 mg · kg-1 of body weight had an increased survival rate in the candidemia model compared with phosphate-buffered saline (PBS)-treated mice, together with a diminished kidney fungal burden. Thus, IDR-1018 was able to protect against murine experimental candidemia and has the potential as an adjunctive therapy.