A cat exhibiting a characteristic cutaneous lesion on its nose caused by Sporothrix brasiliensis in Rio de Janeiro. Credit: Dr. Sandro Antonio Pereira (Laboratory of Clinical Research on Dermatozoonoses in Domestic Animals, Evandro Chagas National Institute of Infectious Diseases – Oswaldo Cruz Foundation, Rio de Janeiro, Brazil)
A deadly fungal epidemic in Brazil is evolving fast: pollution, cats, and genetics may be fueling its unstoppable spread.
Brazil is facing the world’s largest and most persistent sporotrichosis epidemic, a fungal infection spread primarily through cats. A new study reveals an alarming genetic diversity in the fungus, suggesting that urban pollutants may be accelerating its evolution. Researchers identified molecular markers that could enhance diagnostics and treatments, while also highlighting the rapid adaptation and virulence of Sporothrix brasiliensis.
Unraveling the Largest Sporotrichosis Epidemic
A recent study led by Dr. Anderson Messias Rodrigues of the Federal University of São Paulo, and funded by the São Paulo Research Foundation (FAPESP), has revealed new insights into Brazil’s ongoing sporotrichosis epidemic, the largest and longest-lasting outbreak of this fungal infection in the world.
Sporotrichosis is a chronic disease that primarily affects the skin and lymphatic system, and in some cases, internal organs. It is usually caused by fungi from the Sporothrix genus. Unlike most fungal infections, sporotrichosis can be transmitted from animals to humans, with infected cats serving as a major source of infection through scratches, bites, or contact with bodily fluids.
Genetic Diversity and Urban Pollutants
The research team analyzed 104 isolates of Sporothrix fungi, focusing on the 3-carboxymuconate cyclase (CMC) gene, which produces an important antigen known as Gp60-70. They discovered 79 distinct genetic variants, revealing a much higher level of genetic diversity than previously thought. Molecular analysis showed high levels of polymorphism in Sporothrix brasiliensis and Sporothrix schenckii, suggesting recent population growth or adaptive evolution.