Cryptococcosis in HIV/AIDS patients in northern Brazil: Clinical aspects, molecular types and isolation of agents from environmental samples associated with patients.

OBJECTIVES: In the state of Amazonas, northern Brazil, cryptococcosis is endemic, with a predominance of Cryptococcus neoformans in individuals with HIV/AIDS, and Cryptococcus gattii VGII in non-HIV individuals. This study analysed the clinical isolates and clinical-epidemiological characteristics of HIV/AIDS patients diagnosed with cryptococcosis in a tertiary healthcare facility in Manaus, Amazonas and investigated the presence of agents of cryptococcosis in environmental samples. METHODS: A survey was made of data from HIV/AIDS patients diagnosed with cryptococcosis between January 2017 and December 2019, and environmental samples were collected at the patients' and their neighbours' homes. The isolates were submitted to morphophysiological analysis and PCR-RFLP typing to determine the molecular types. RESULTS: Clinical-epidemiological characteristics of 55 patients and 75 clinical isolates were analysed. Neurocriptococcosis was the clinical form observed in 98.2% (n = 54/55) of patients. A total of 38.1% (n = 21/55) of patients died within 100 weeks, of which 21.8% (n = 12/55) died less than a month after the diagnosis of cryptococcosis. C. neoformans VNI (n = 68/75), C. neoformans VNII (n = 1/75), C. gattii VGI (n = 3/75) and C. gattii VGII (n = 3/75) were identified. Mixed infection was observed in two patients, one by C. neoformans VNI and VNII and the other by C. neoformans VNI and C. gattii VGI. Cryptococcus VNI was detected in three (n = 3/51) households, one of a patient (n = 1/17) and two households that neighbour patients' houses (n = 2/34). CONCLUSIONS: This study demonstrated the prevalence of C. neoformans VNI, which is a cause of cryptococcosis in patients with HIV/AIDS in the state of Amazonas, and revealed a greater diversity of molecular types affecting these patients in the region than in previous studies. In the studied group, a high mortality rate was observed, which reflects the importance of early diagnosis, and evidences cryptococcosis as an AIDS-defining disease and an important public health problem in the region. The home environment proved to be a potential source of infection/reinfection by C. neoformans VNI.

Milk-clotting proteases from Pleurotus albidus: an innovative alternative for the production of Minas frescal cheese

Pleurotus albidus, a naturally growing species in the Amazon region, has been considered a promising source of milk-clotting proteases. The production of such enzymes using lignocellulosic residues is a sustainable alternative to replace mammalian rennet. The application of P. albidus milk-clotting proteases in cheese making has not yet been reported in the scientific literature. The aim of this study was to characterize the milk-clotting proteases of P. albidus and use these enzymes in the production of Minas frescal cheese. For the production of coagulating proteases, the mushroom was grown in açaí seeds supplemented with rice bran (10%, w/w). The parameters affecting the production of coagulant, such as inoculum size, fermentation time, initial pH of cultivation medium and age of the inoculum were evaluated. The coagulant extract obtained under optimal production conditions was evaluated for optimal pH and temperature, pH and temperature stability, effect of ions and inhibitors. Significant production of coagulating proteases was obtained under the following conditions: inoculum size (2.5%), fermentation time (10 days), initial pH of the cultivation medium (6), and inoculum age (10 days). The coagulant exhibited significant catalytic activity in pH 5.0 at 55°C, with stability at 45°C and was completely inhibited by iodoacetic acid. The milk-clotting proteases of P. albidus were efficient for making Minas frescal cheese that presented 55.0% of moisture, 20.0% of lipids and 17.20% of protein. Pleurotus albidus is a potential source of milk-clotting proteases that can be applied in dairy industry for production of fresh Minas frescal cheese.