Pathogenicity of Cryptococcus neoformans VNI (ST 32) recovered from environmental and clinical isolates in Nigeria

We present the comparative pathogenicity of Nigeria environmental and clinicalCryptococcus neoformans VNI (ST32) strains in an animal model. Isolates previously identified and confirmed in a different study, using matrix-assisted laser desorption ionization –time-of-flight mass spectrometry (MALDI–TOF MS) and multi-locus sequence typing (MLST) techniques, were inoculated into male mice weighing 26 ± 4.0 g. Postinfection survival time, tissue fungal burden, and histopathological changes were observed. Log–rank survival curve comparisons show ed that there is a significant difference between clinical and control isolates and between environmental and control isolates. However, when intragroup and intergroup comparisons were made, no significant difference was observed. There was a significant difference when the brain fungal burden of mi ce infected with environmental isolate was compared with the kidney fungal burden. Tissues of the control group inoculated with PBS showed no evidence of lesions. The mouse group infected with clinical isolates showed a significant difference when the brain fungal burden was compared with the kidney fungal burden. No lesion was produced in the kidneys of mouse groups infected with environmental and positive control isolates. The evaluated pathogenicity indices in this study may suggest that both the environmental and clinical isolates ofC. neoformans VNI exhibit similar pathogenicity potential.
Source: Comparative Clinical Pathology - Category: Pathology Source Type: research