Perspectives on non-neoformanscryptococcal opportunistic infections

Abstract

Non-neoformans Cryptococcus species, including C. laurentii and C. albidus, have historically been classified as exclusively saprophytic. However, recent studies have increasingly implicated these organisms as the causative agent of opportunistic infections in humans. Herein, the case is presented of C. laurentii meningitis in a critically ill patient receiving corticosteroids. C. laurentii has been implicated in an additional 18 cases of opportunistic infection, predominantly of the skin, bloodstream, and central nervous system. The most clinically significant risk factors for non-neoformans cryptococcal infections include: impaired cell-mediated immunity, recent corticosteroid use, and invasive catheter placement. This article provides a comprehensive review of the clinical relevance, pathogenesis, risk factors, and treatment of non-neoformans Cryptococcus species.

Incidence and clinical outcome of Cryptococcosis in a nation with advanced HIV surveillance program

“…Whereas, C. laurentii rarely causes infection in human. For instance, C. laurentii has been reported in literature in only 19 cases, predominantly of the skin, bloodstream, and central nervous system [10,18]. It has been reported that the most clinically significant risk factors for C. laurentii infection are impaired cell-mediated immunity, recent corticosteroid use, and invasive catheter placement.…”

New pathogens, new tricks: emerging, drug‐resistant fungal pathogens and future prospects for antifungal therapeutics

“…The rise in incidence of these pathogens may be due to improvements and availability of diagnostic tools. The most commonly identified emerging cryptococcal species associated with immunocompromised hosts are Cryptococcus laurentii and Cryptococcus albidus , which account for 80% of non‐ neoformans and non‐ gattii Cryptococcus infections . Susceptibility testing has revealed that these species are not susceptible to flucytosine, and 50% of C. laurentii and 80% of C. albidus have an elevated MIC to fluconazole (≥16 mg/L), although the mechanisms of resistance have not been conclusively identified.…”

“…The most commonly identified emerging cryptococcal species associated with immunocompromised hosts are Cryptococcus laurentii and Cryptococcus albidus, which account for 80% of non-neoformans and non-gattii Cryptococcus infections. 127,128 Susceptibility testing has revealed that these species are not susceptible to flucytosine, and 50% of C. laurentii and 80% of C. albidus have an elevated MIC to fluconazole (ࣙ16 mg/L), 78 although the mechanisms of resistance have not been conclusively identified. This mirrors the trend observed among emerging non-albicans Candida species with high rates of fluconazole resistance and suggests that widespread use of this antifungal may be responsible for the new emergence of diverse, fluconazole-resistant fungal pathogens.…”

Clinical significance of nosocomial Cryptococcus laurentii in urine: A case series

“…To the Editor-The genus Cryptococcus spp comprises~70 species, 1 of which the C. neoformans-C. gattii complex are considered pathogenic. However, non-neoformans cryptococci, such as Cryptococcus laurentii and Cryptococcus albidus, are emerging as opportunistic pathogens, causing disease in patients with impaired cell-mediated immunity (eg, HIV-infected patients or those with hematologic malignancies), in those using steroids or chemotherapeutic agents, and in those with invasive devices.…”

“…2 A recent case report of a patient requiring invasive mechanical ventilation with a long hospital stay, central venous catheter use, and prolonged duration of broad-spectrum antibiotics including echinocandin, developed a C. laurenttii bloodstream infection. 1 Another case report described a cystic fibrosis patient with a prior C. laurentii paranasal sinus colonization who developed pneumonia and disseminated cryptococcosis after sinus surgery. 5 In our case series, the clinicians considered treating the cryptococcuria in some patients; however, the sample size did not allow us to reach conclusions regarding whether treatment of asymptomatic urinary C. laurentii was beneficial; none of these patients developed cryptococcal disease without treatment.…”