Microsatellite typing and susceptibilities of serial Cryptococcus neoformans isolates from Cuban patients with recurrent cryptococcal meningitis

Isolates (n = 19) were recovered from cerebrospinal fluid, blood, urine and semen. Antifungal susceptibilities for amphotericin B, fluconazole, flucytosine, itraconazole, voriconazole, posaconazole and isavuconazole were tested by CLSI M27A3 broth microdilution method. Genotyping was done using a panel of 9 microsatellite (STR) markers: (CT)n, (TG)n, (TA)n, (CTA)n, (TCT)n, (CCA)n, (TTAT)n, (ATCC)n and (TATT)n.The average number of isolates/patient was 2.71. The mean time interval between the collection of any two isolates was 52.5 days. All strains were identified as C. neoformans var. grubii (serotype Aα). Although none of the strains were resistant to the studied drugs, in serial isolates from two patients, MICs values of triazoles increased 4-5 log2 dilutions over time. STR patterns showed 14 distinctive profiles. In three patients the recurrent infection was associated with genotypically identical isolates. The four other patients had relapse isolates which were genotypically different from the initial infecting strain.Recurrences of cryptococcal meningitis in our series of patients was not associated with development of drug resistance of the original strain but by an initial infection with different strains or a reinfection with a new strain.The incidence of cryptococcosis started to increase with the beginning of the acquired immune deficiency syndrome (AIDS) epidemic in the early 1980 s. Its frequency declined in the Western world since the mid 1990 s due to the use of highly active antiretroviral therapy (HAART). However, cryptococcal meningitis is still one of the most common life-threatening opportunistic fungal infections in immunocompromised patients, particularly among those with AIDS in Sub-Saharan Africa [1] and Asia [2]. These patients show a high tendency to relapse despite effective antifungal therapy. Early studies performed with karyotyping and restriction fragment length polymorphism (RFLP) analysis of serial isolates of AIDS patients in New Yo