Fungi as pathogens and parasites

Many fungi are parasites on plants, animals, humans, and other fungi. Serious pathogens of many cultivated plants causing extensive damage and losses to agriculture and forestry include the rice blast fungus Magnaporthe oryzae.

Rice_blast_Magnaporthe_grisea

Gray leaf spot Magnaphorte gricea

Tree pathogens such as Ophiostoma ulmi and Ophiostoma novoulmi causing Dutch elm disease, and Cryphonectria parasitica responsible for chestnut blight, and plant pathogens in the genera Fusarium, Ustilago, Alternaria, and Cochliobolus. 

Dutch elm disease, Ophisotoma novo-ulmi

         

Dutch Elm Disease

   

Chesnut blight showing fruiting bodies of  Cryphonectria parasitica

Some carnivorous fungi, like Paecilomyces lilacinus, are predators of nematodes, which they capture using an array of specialized structures such as constricting rings or adhesive nets.

     

Paecilomyces lilacinus

Some fungi can cause serious diseases in humans, several of which
may be fatal if untreated. These include aspergilloses, candidoses,
coccidioidomycosis, cryptococcosis, histoplasmosis,

mycetomas, and paracoccidioidomycosis.

Mycoses caused by Paecilomyces lilacinus 

   

Aspergilloses

    

Candidoses

 

Coccidioidomycosis

   

Cryptococcosis

   

Histoplasmosis

   

Mycetomas

    

Paracoccidioidomycosis

 Furthermore, persons with immunodeficiencies are particularly susceptible to disease by genera such as Aspergillus, Candida, Cryptoccocus, Histoplasma,and Pneumocystis.

Other fungi can attack eyes, nails, hair, and especially skin, the so called dermatophytic and keratinophilic fungi, and cause local infections such as ringworm and athlete's foot. 

   

Ringworm

   

Sever Athlete's foot

Fungal spores are also a cause of allergies, and fungi from different taxonomic groups can evoke allergic reactions.