P404 Biofilm formation by Cryptococcus species isolated from Cerebrospinal fluid (CSF)

Abstract

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM IntroductionCases of Cryptococcal meningitis have increased exponentially in the last 30 years due to the advent of AIDS, the use of immunosuppressive drugs, and chemotherapeutic agents. Among HIV-infected patients’ relapse is seen often. The ability of Cryptococcus to form biofilm may influence the clinical outcome of patients though poor adherence to ART and/or anti-fungal therapy is a known factor for relapse.MethodsDuring a period of 2 years and 8 months (August 2019 to March 2022), 11 Cryptococcus sps. were isolated from 59 cerebrospinal fluids (CSF) collected from patients clinically suspected of meningitis. Samples were examined and processed by direct microscopy and fungal culture. Identification of cryptococcal isolates was carried out by conventional method and by using an automated VITEK-2 (Biomerieux) identification system. Biofilm production was estimated by XTT reduction assay. Statistical analysis was done in SPSS version 21 (IBM) and Fischer's exact was used to find an association between biofilm formation and relapse.ResultsOut of 11 Cryptococcus isolated 10 were identified as C. neoformans and one was C. gattii. Three HIV-infected patients had recurrent cryptococcal meningitis. A total of 6 (42.8%) cases reported non-adherence to ART and/or anti-fungal therapy. Biofilm was detected in 3 isolates one of which was from a patient with re-current cryptococcal meningitis but the association is not statistically significant.DiscussionNon-adherence to HAART among HIV patients is known to increase the rate of hospitalization and mortality. Recurrence of cryptococcal meningitis has been thought to be due to drug resistance. But Illnait-zaragozí MT et al. based on STR typing technique, concluded that recurrence was due to co-infection with different strains or strains genetically modified during the long maintenance therapy. Biofilms produced by bacteria as well as fungus have been associated with more stubborn, recurrent, and persistent infections, especially among the immunocompromised population. Although biofilm production was detected in only one out of 3 isolates from recurrent cryptococcal meningitis, it may be a contributing factor along with non-adherence to treatment.ConclusionNon-adherence to ART and/or antifungal therapy is an important cause of relapse of cryptococcal meningitis. Biofilm production may be responsible for recurrence, especially among non-adherent patients. Further studies with a larger sample size may shed more light on the association between biofilm formation and recurrence.