Infections due to Rare Cryptococcus Species. A Literature Review

Abstract

Infections due to rare Cryptococcus species (other than C. neoformans species complex, C. gattii species complex, C. albidus or C. laurentii) are barely reported. The aim of this work is to present a comprehensive literature review of all the papers describing infections due to these species referenced in the main databases (PubMed/MEDLINE, ScienceDirect, Scopus, and Google Scholar). Clinical and epidemiological data together with laboratory findings (identification and antifungal susceptibility) of each isolate were analyzed. Fifty-eight cryptococosis due to rare species were described in 46 papers between 1934–2018. These reports included 16 rare Cryptococcus spp. that were generally associated with nervous system infections and fungemias. Some species are non-capsulated and are not able to grow at 37 °C. Few species were identified by commercially available methods, making internal transcriber spacer (ITS) and D1/D2 regions sequencing mandatory. The most potent antifungal was amphotericin B (although some species showed high MIC values). The studied strains showed high MICs values to 5-fluorocytosine (all >64 µg/mL), echinocandins (all >8 µg/mL), and fluconazole (>80% of the MICs >4 µg/mL). Due to the scarcity of the data and the absence of guidelines for the treatment of these infections, this review could be informative and could help in the diagnosis and treatment of these infections.

Airborne Fungi in Show Caves from Southern Spain

“…Regarding the potential danger to human health, the most abundant fungi recorded in the caves have been considered opportunistic pathogens. They encompass Cladosporium cladosporioides [42], Beauveria bassiana [43], Parengyodontium album [44], Schyzophyllum commune [45], Aspergillus nidulans [46], Penicillium chrysogenum [47], in addition to basidiomycetous yeasts [48][49][50]. Jurado et al [51] reviewed the role of pathogenic and opportunistic microorganisms in caves and concluded that "the most-frequent diseases produced by cave microorganisms are located in the respiratory system and, therefore, it is recommended that visitors should, at the least, wear protective masks".…”

Search for Cryptococcus neoformans/gattii Complexes and Related Genera (Filobasidium, Holtermanniella, Naganishia, Papiliotrema, Solicoccozyma, Vishniacozyma) spp. Biotope: Two Years Surveillance of Wild Avian Fauna in Southern France

“…Nevertheless, this study shows that the risk of exposure to highly pathogenic Cryptococcus species in nonurban human populations and bird caretakers is limited. For the less pathogenic RCFC species, particularly those already known to infect humans [ 5 ], the risk may be elevated in care personnel working in aviaries or wild fauna protection centers. The risk may also be present for peri/suburban human populations because residential gardens are attractive to some carrier birds, particularly Passeriformes.…”

“…They are followed by N. albida and P. laurentii , which account for 80% of non- neoformans/gattii cryptococcal infections. The remaining 20% of non- neoformans/gattii cryptococcal mycoses are due to 16 species of rare Cryptococcus and former Cryptococcus [ 5 ].…”

“…Concerning C. neoformans and C. gattii species complexes, the most virulent species, the assessment, management, and control of a potential reservoir is difficult while these species impose a heavy burden on health systems in countries with a high HIV prevalence [ 4 ]. Concerning the less virulent RCFC species, the absence of a clear biotope or reservoir hinders the understanding of their biology while some of them could be responsible for human or veterinary infections [ 5 ]. Given the strong association of C. neoformans s.l.…”

Central Nervous System Cryptococcosis in Patients With Sarcoidosis: Comparison With Non-sarcoidosis Patients and Review of Potential Pathophysiological Mechanisms

“…is responsible for one million infections per year among human immunodeficiency virus (HIV)-infected patients in the world; of these, approximately 625,000 die ( 15 ). Cryptococcus neoformans and Cryptococcus gattii are the most common and major pathogenic species complex in the genus Cryptococcus ( 16 ). C. gattii shares major virulence determinants with C. neoformans and was previously thought to be a subtype of C. neoformans , but genomic and transcriptomic studies revealed distinctions leading to recognize C. gattii as a unique species ( 17 ).…”