Chlamydospores

Chlamydospores are thick-walled, resting spores produced by certain fungi as a long-term survival form. They typically arise from hyphal cells or yeast-like cells when nutrients are limited, stressed, or aging, and they may be terminal (at the end of a hypha) or intercalary (along the hypha). Chlamydospores are usually larger than surrounding cells and feature a robust, multilayered cell wall that contributes to their resilience.

The primary function of chlamydospores is survival during adverse environmental conditions. They are dormant and desiccation- and temperature-tolerant, capable of withstanding unfavorable periods and germinating later to form new hyphae or colonies when conditions improve. Not all fungi produce chlamydospores; they are characteristic of a subset of species, including some Candida yeasts and various filamentous fungi such as Fusarium, Cladosporium, and Phialophora.

In clinical and diagnostic mycology, chlamydospore formation serves as a useful morphological clue. For example, Candida albicans and some related species form chlamydospores on nutrient-limited media, which helps differentiate them from other yeasts. However, identification is supported by additional tests or molecular methods.

Chlamydospores are non-motile and non-reproductive structures that function primarily as dormant survival units. Upon the return of favorable conditions, they germinate to reinitiate growth and colonization.