Читать книгу Parasitology - Alan Gunn - Страница 121

Some estimates suggest that there may be over a million species of fungi although less than 10% of these have so far been described. Unlike plants, fungi are heterotrophs – that is, they cannot make their own food and must gain their nutrients by breaking down existing organic matter. Most fungi do this by acting as saprophytes, that is, they break down dead organic matter. In addition, many species are in symbiotic relationships with plants and invertebrates, whilst some are parasites of other fungi, plants, and invertebrate and vertebrate animals. Some of these parasitic species are important in human and veterinary medicine, as well as wildlife ecology. For example, Pneumocystis (which was once thought to be a protozoan) is a major cause of morbidity and mortality in AIDS patients (Gilroy and Bennett 2011), the skin disease ‘ringworm’ in cattle is caused not by a helminth but fungi such as Trichophyton verrucosum (Pier et al. 1994), and chytridiomycota fungi are responsible for widespread and catastrophic levels of mortality among amphibians in many parts of the world (Fisher and Garner 2020). However, only the Microsporidia will be covered here.