How Environmental Fungi Cause a Range of Clinical Outcomes in Susceptible Hosts

Abstract

Life-threatening infections in immunocompetent individuals have been documented for all the fungi we discuss. However, the majority of life-threatening infections typically present in individuals with particular immunocompromising risk factors [4]. Thus, the outcome of infection is determined by a constellation of fungal traits and host susceptibilities (Table 1). In this review, we discuss host and fungal factors that contribute to infectivity, persistence within the host, and progression to life-threatening infections for five groups of fungi: Cryptococcus, Aspergillus, Histoplasma, Blastomyces, and Coccidioides spp. These common environmental fungi do not require an infectious life cycle for their survival. They are not transmissible between humans, nor are humans considered a particularly suitable niche for commensalism, such as it is for certain Candida spp. [10]. We do not discuss Candida spp., which are addressed elsewhere in this issue. Aspergillus spp. and Cryptococcus spp. are considered some of the more cosmopolitan fungal species. Due to their large geographical range, respiratory exposure to these fungi is commonplace [11]. Aspergillus spp. commonly cause both asymptomatic and symptomatic 2

Global warming impact on the expansion of fundamental niche of Cryptococcus gattii VGI in Europe

“…Environmental fungi able to infect humans represent a serious health problem. A growing number of fungal species associated with human diseases are emerging due to the increase in the number of susceptible hosts such as immunocompromised patients (Denham et al ., 2019; Friedman and Schwartz, 2019). Aspergillus , Candida , Cryptococcus , Fusarium , Mucor , Rhizopus , Histoplasma , Coccidioides , Blastomyces , Scedosporium , Sporothrix , are just some example of fungal genera including fungi able to cause life‐threatening disseminated diseases with a high mortality rate (de S Araújo et al ., 2017).…”

Immunotherapy against Systemic Fungal Infections Based on Monoclonal Antibodies

“…There are currently~120,000 identified fungal species [12], with only a few hundred capable of causing disease in humans. Of these, only a small number affect healthy people [13,14], differing in severity from mild to severe systemic infections [2,7].…”

Differential Thermotolerance Adaptation between Species of Coccidioides

“…This “preadaptation” is particularly important to pathogenic fungi that can grow in high temperatures, which allows colonization of mammalian tissues [ 55 , 56 ]. For example, Coccidioides is adapted to grow at high temperatures in the environment (i.e., North and South American deserts), and is able to colonize a wide range of endothermic hosts throughout the Americas [ 57 , 58 , 59 , 60 , 61 ]. C. immitis is endemic to the California Central Valley; whereas C. posadasii is widely distributed, but has highest prevalence in the Sonoran Desert.…”