First case of mixed infection with Cryptococcus deuterogattii and Cryptococcus neoformans VNI in an Ivorian HIV-positive patient

Abstract

Introduction: Cryptococcal meningitis (CM) may be caused by several species of Cryptococcus.

Case presentation: We describe a fatal case of CM in a HIV-positive patient from Ivory Coast infected by Cryptococcus neoformans VNI and Cryptococcusdeuterogattii. Isolates were recovered from cerebrospinal fluid (CSF) prior to systemic antifungal treatment. Six isolates were studied (the entire culture plus five isolated colonies from it). Serotyping was performed via LAC 1 and CAP 64 gene amplification. Genotyping was performed using restriction fragment length polymorphism (RFLP) analysis of the URA5 gene, (GACA)₄, (GTG)₅ and M13 PCR fingerprinting. URA5-RFLP analysis identified the original culture with two different molecular type combinations. However, URA5-RFLP profiles of the five colonies isolated from the original sample revealed two different species. Four colonies were identified as C.deuterogattii and the last isolate as C.neoformans VNI. The in vitro susceptibility profile was determined using the standard method according to the CLSI M27-A3 protocol. The isolates were susceptible to the tested antifungals (fluconazole, flucytosine and amphotericin B). Treatment with fluconazole (1200 mg day^-1) was initiated; however, the patient died 17 days after the onset of antifungal therapy.

Conclusion: This is the first reported case of mixed infection with C. neoformans and C.deuterogattii in a HIV-positive patient.

Keywords: Cryptococcus neoformans; AIDS; Cryptococcus deuterogattii; antifungal susceptibility; genotyping; mixed infection.

Fig. 1.

URA5 gene restriction fragment length polymorphism (RFLP) of the isolates. Lanes: 1, Ladder 100 pb (Sigma Aldrich); 2, entire culture; 3–7, the five isolated colonies with lanes 3, 4, 5 and 7 corresponding to C. deuterogattii profiles and lane 6 corresponding to C. neoformans VNI profile.