How a Deadly Superbug Tricks the Immune System to Survive in Hair Follicles

A hospital patient might remain unaware of the presence of the deadly superbug Candida auris on their skin, as there are no visible signs such as rashes or itching. The pathogen typically infiltrates deeper tissues only after gaining access through an open wound or an IV line. Researchers at the University of California, San Francisco sought to understand the reasons behind the fungus's ability to thrive in the body.

Their findings, published in Science, reveal that the key lies within the hair follicles, where C. auris manipulates an immune signal to its advantage.

C. auris is far more adept at colonizing human skin compared to its close relative Candida albicans. While C. albicans is cleared from the skin within days due to the release of an immune molecule called IL-17, C. auris exhibits a unique behavior. It reshapes its cell wall to expose more chitin, a substance normally associated with antiviral defenses.

This triggers the production of interferon gamma, which dampens the skin's anti-fungal response and hinders the natural shedding of old cells, creating an ideal environment for the fungus to settle in.

The study, conducted by researchers at the University of California, San Francisco, highlights that C. auris's ability to trigger interferon gamma rather than IL-17 allows it to establish itself in hair follicles, making it challenging to eliminate from the skin. With no reliable way to remove C. auris from the skin, researchers are looking into potential treatments that could target this specific immune signaling pathway.

By silencing the interferon gamma response or blocking chitin production, scientists aim to disrupt C. auris's colonization process, potentially preventing the development of serious infections. However, these interventions have yet to be proven effective in clearing the fungus from human skin. Nevertheless, understanding how C. auris manages to survive in hair follicles could provide crucial insights into preventing its spread and mitigating its impact on vulnerable patients.