Formation and germination of fungal arthroconidia.

A large variety of fungi are known to produce asexual spores known as arthroconidia. These propagules are formed by segmentation of existing hyphae and may form by several mechanisms. The specific processes of formation may lead to acropetal, basipetal, or random formation of endoarthroconidia or exoarthroconidia. The development of arthroconidia is a survival response to the depletion of nutrients or other environmental stresses and, in at least one case, is accompanied by the excretion of high levels of antibiotics. Arthroconidia are generally not as resistant to physical factors as are other fungal reproductive structures and are also susceptible to a variety of antibiotics and disinfectants. Arthroconidia are produced by some medically important fungi and in some cases, such as coccidioidomycosis, they are the principal means of dissemination. Germination of arthroconidia in complex media generally does not require specific "activation" events.