Sequence Variation of Candida albicans Sap2 Enhances Fungal Pathogenicity via Complement Evasion and Macrophage M2-Like Phenotype Induction.

Candida albicans (C. albicans) is an opportunistic pathogen increasingly causing candidiasis worldwide. This study aims to investigate the pattern of systemic immune responses triggered by C. albicans with disease associated variation of Sap2, identifying the novel evasion strategies utilized by clinical isolates. Specifically, a variation in clinical isolates is identified at nucleotide position 817 (G to T). This homozygous variation causes the 273rd amino acid exchange from valine to leucine, close to the proteolytic activation center of Sap2. The mutant (Sap2-273L) generated from SC5314 (Sap2-273V) background carrying the V273L variation within Sap2 displays higher pathogenicity. In comparison to mice infected with Sap2-273V strain, mice infected with Sap2-273L exhibit less complement activation indicated by less serum C3a generation and weaker C3b deposition in the kidney. This inhibitory effect is mainly achieved by Sap2273L -mediated stronger degradation of C3 and C3b. Furthermore, mice infected with Sap2-273L strain exhibit more macrophage phenotype switching from M0 to M2-like and more TGF-ß release which further influences T cell responses, generating an immunosuppressed cellular microenvironment characterized by more Tregs and exhausted T cell formation. In summary, the disease-associated sequence variation of Sap2 enhances pathogenicity by complement evasion and M2-like phenotype switching, promoting a more efficient immunosuppressed microenvironment.

Pathogen Analysis of Superficial Mucocutaneous Mycosis in a Tertiary A-level Hospital from 2007 to 2018.

OBJECTIVE: This study aimed to analyze the fungal species of pathogens isolated from patients with superficial mucocutaneous mycosis from May 2007 to December 2018. METHODS: A retrospective analysis was carried out to determine the pathogenic fungi isolated from patients with superficial fungal infections in the Medical Mycology Clinical Laboratory, Department of Dermatology and Venereology, Union Hospital, from May 2007 to December 2018. RESULTS: A total of 7639 strains were obtained, belonging to 21 genera and 36 species. They mainly consisted of Candida (3707/7639, 48.53%) and dermatophytes (3594/7639, 47.05%). The specimens were skin scales, nail shavings, secretions on the nail grooves, broken or diseased hair and dandruff, secretions or pseudomembrane of the external genitalia, and the oral mucosa. A total of 7300 patients were enrolled in this study, including 3301 males and 3999 females aged 2 months to 92 years old with a median age of 46.04 years old except for 633 patients whose ages were unknown. Two strains of different species were isolated from each of 339 patients at different body sites. The most frequent species were Trichophyton rubrum complex (2906/7639, 38.04%), Candida albicans (2619/7639, 34.28%), and unclassified Candida spp. Dermatophytes were mostly isolated from glabrous skin (2138/3594, 59.49%), with T. rubrum complex being the predominant species. Candida strains were most commonly isolated from mucosal sites (1979/3707, 53.39%), and C. albicans was the most prevalent causative agent. CONCLUSION: The main distribution of pathogenic fungal species isolated from patients with superficial mycosis from 2007 to 2018 in Wuhan, Hubei province and the surrounding areas was that Candida slightly outnumbered dermatophytes. Among all of the isolated strains, T. rubrum complex was the most abundant.

Aetiological changes of tinea capitis in the Hubei area in 60 years: Focus on adult tinea capitis.

BACKGROUND: Tinea capitis is a common dermatophyte infection of the scalp primarily affecting children, with less frequent, though not rare, observation in adults. OBJECTIVE: This study aimed to assess changes in the causative agents of adult tinea capitis over a 60-year period in the Hubei area. METHODS: A retrospective, single-centre study was performed on 164 adults with tinea capitis between 1960 and 2020. RESULTS: Out of 1113 cases of tinea capitis, 164 patients were adults, representing 14.7% of all patients. Adult tinea capitis was slightly more prevalent in males (91, 55.5%) than in females (73, 44.5%), but gender difference was not statistically significant between adults and children. Adult tinea capitis was most prevalent between the ages of 18 and 29 years, with a mean age of 22 years. Trichophyton schoenleinii was the most common dermatophyte in adult tinea capitis (78, 47.6%), followed by Trichophyton violaceum (58, 35.4%). Most adult tinea capitis cases before the 1980s were caused by T. schoenleinii, but T. violaceum has become the leading pathogen for recent adult tinea capitis cases. CONCLUSION: Tinea capitis is not a disease exclusive to children. On the contrary, an upward trend of tinea capitis in adults has been observed in recent years. T. violaceum has become the dominant causative agent of adult tinea capitis in the Hubei area, replacing T. schoenleinii. These results provide a better understanding of the treatment and prevention of tinea capitis in adults.

In Vitro and In Vivo Activities of Essential Oil from the Seed of Anethum graveolens L. against Candida spp.

The essential oil produced from the seed of Anethum graveolens L. (Umbelliferae) was tested in vitro and in vivo anti-Candida activity. The microbroth dilution method was used in the minimal inhibitory concentration (MIC), according to M27-A3 of the guidelines of the Clinical and Laboratory Standard Institute (CLSI). And then, efficacy evaluation of essential oil in the prophylaxis and treatment of experimental vaginal candidiasis was performed in immunosuppressed mice. The anti-Candida activity was analyzed by microbiological and histological techniques and was compared with that of fluconazole (FCZ). The results showed essential oil was active in vitro against all tested strains, with MICs ranging from 0.312 µL/mL (for C. tropicalis, C. parapsilosis, and C. krusei) to 0.625 µL/mL (for 6 isolated C. albicans strains). Essential oil (2% v/v) was highly efficacious in accelerating C. albicans 09-1555 clearance from experimentally infected mice vagina by prophylaxis and therapeutic treatments. In both therapeutic efficacy and prophylaxis studies, the histological findings confirmed the microbiological results. The experimental results revealed that the tested essential oil is effective against vulvovaginal candidiasis in immunosuppressed mice.