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Assessing the Putative Anticryptococcal Properties of Crude and Clarified Extracts from Mollusks
Published on: December 2, 2022
Molecular characterization and evaluation of virulence factors of Cryptococcus laurentii and Cryptococcus neoformans
Leonardo Andrade-Silva1, Kennio Ferreira-Paim, Mario León Silva-Vergara
1Disciplina de Biologia Molecular, Departamento de Ciências Biológicas, Universidade Federal do Triângulo Mineiro, Avenida Frei Paulino, 30, CEP 38025-180, Uberaba, Minas Gerais, Brazil.
Abstract:
Cryptococcosis is a common opportunistic fungal infection that is mainly caused by the species Cryptococcus neoformans and Cryptococcus gattii, but there have recently been several reports of infection by non-neoformans Cryptococcus species. The aims of this study were to genetically characterize Cryptococcus spp. isolated from external hospital areas in Minas Gerais State, Brazil, and to evaluate their pathogenic potential, analyzing their phospholipase and melanin production and the capacity for capsule enlargement. Seventy-three different samples were collected: 62 from bird droppings and 11 from tree detritus. C. neoformans alone was isolated from 43.8% of the samples, Cryptococcus laurentii alone from 23.3% and both fungi were found together in 10.9%. C. laurentii was exclusively isolated from 45% (5/11) of the tree samples (Anacardium occidentale, Guazuma ulmifolia, Mangifera indica and Ficus benjamina). Among the 51 C. neoformans isolates, 47 were classified as type VNI and four as type VNII. All of the C. neoformans isolates were of MATα type. Among the 21 isolates of C. laurentii genotyped using the URA5-RFLP technique, 16 amplified a 1.6kb amplicon which produced a specific restriction profile in 15 isolates. In C. neoformans, 76.4% of the isolates were capable of capsule enlargement in the induction medium and 92.1% were phospholipase producers. In C. laurentii, 7.4% of the isolates were capable of capsule enlargement and 85.1% were phospholipase producers. Characterization of the genotypes and the pathogenic potential of the Cryptococcus spp. isolates studied may contribute towards better understanding of the epidemiology of cryptococcosis and the ecology of agents causing this disease in our region.
Insights
This study genetically characterized Cryptococcus species from Brazil, finding Cryptococcus neoformans and Cryptococcus laurentii in hospital environments. It assessed their pathogenic potential, revealing differences in capsule enlargement and phospholipase production.
Area of Science:
- Medical Mycology
- Fungal Pathogenesis
- Environmental Microbiology
Background:
- Cryptococcosis, an opportunistic fungal infection, is primarily caused by Cryptococcus neoformans and Cryptococcus gattii.
- Emerging reports highlight infections by non-neoformans Cryptococcus species, necessitating broader ecological and pathogenic characterization.
- Understanding Cryptococcus species distribution in environmental niches is crucial for public health surveillance.
Purpose of the Study:
- To genetically characterize Cryptococcus species isolated from external hospital areas in Minas Gerais, Brazil.
- To evaluate the pathogenic potential of these isolates, focusing on phospholipase and melanin production and capsule enlargement.
- To investigate the prevalence and genotypes of Cryptococcus neoformans and Cryptococcus laurentii in environmental samples.
Main Methods:
- Collection of 73 environmental samples (bird droppings and tree detritus).
- Isolation and identification of Cryptococcus species using standard microbiological techniques.
- Genotyping of Cryptococcus neoformans (VNI, VNII, MATα) and Cryptococcus laurentii (URA5-RFLP).
- Assessment of pathogenic potential: capsule enlargement, phospholipase production, and melanin production.
Main Results:
- Cryptococcus neoformans (43.8%) and Cryptococcus laurentii (23.3%) were frequently isolated; both were found together in 10.9% of samples.
- Cryptococcus laurentii was predominantly found in tree detritus (45%).
- Most C. neoformans isolates were VNI type (47/51) and MATα.
- High phospholipase production was observed in both C. neoformans (92.1%) and C. laurentii (85.1%).
- Capsule enlargement capacity was higher in C. neoformans (76.4%) than in C. laurentii (7.4%).
Conclusions:
- The study identified Cryptococcus neoformans and Cryptococcus laurentii in Brazilian hospital environments, highlighting their ecological presence.
- Differences in pathogenic potential, particularly capsule enlargement, were observed between the species.
- Genetic characterization provides insights into the epidemiology and ecology of Cryptococcus species in the region, relevant for cryptococcosis management.
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