Picture: ISTOCK
Picture: ISTOCK

Large populations of potentially deadly fungi are thriving in central Cape Town. But the microbiologist who discovered them says the cryptococcal fungi — which cause cryptococcal meningitis — do not pose a risk in people whose immune systems have not been compromised by HIV/AIDS.

After tuberculosis‚ cryptococcal meningitis is the leading cause of death in HIV/AIDS patients in Sub-Saharan Africa. People become infected when they inhale the airborne microscopic spores produced by pathogenic cryptococci, which grows on decaying wood.

Last year‚ SA launched the world’s largest national screening programme to detect cryptococcal meningitis in HIV patients‚ and Stellenbosch University PhD student Jo-Marie Vreulink told TimesLIVE on Thursday that it offered "excellent" protection from the disease.

Vreulink’s supervisor‚ Prof Alf Botha‚ had been searching for cryptococcal fungi in SA since 2003 when his student found numerous colonies in samples collected from a public park in the centre of Cape Town.

"It was late on a Friday afternoon and I was working alone. I decided to check on the petri dishes that I prepared from the samples collected in Cape Town‚" said Vreulink‚ whose findings have been published in the journal Fungal Ecology.

"On most of the dishes, brown colonies — typical of these cryptococcal pathogens — were growing. This was such a rare occasion that I started working immediately to transfer the colonies to new petri dishes for identification. I was scared to death that the colonies will be overgrown by other micro-organisms if I left it over the weekend."

The Cape Town find and another in the Northern Cape are the first locations of cryptococcal fungi has been found in such large numbers on trees in SA.

Vreulink said evidence from other countries suggested the fungi were found in areas with a combination of pigeons‚ old trees and large numbers of people. Her research efforts have focused on understanding the biology and ecology of the single-celled yeasts that make up the colonies.

"For now‚ I’m focusing on the ecology of these yeasts. I want to understand the population dynamics‚ the genetics, and how these interact with their environment‚" she said. "If we can understand how they survive‚ we can use this knowledge to better predict how they can survive in their human host."

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