Trichoderma species

It is commonly found in soil, dead trees, pine needles, paper, and unglazed ceramics. It often will grow on other fungi. It produces antibiotics which are toxic to humans. It has been reported to be allergenic (7, 17). It readily degrades cellulose.

Fungi are plant like organisms that lack chlorophyll. Many fungi are good and useful while others are harmful to plants and people. There are over 100,000 species of fungi. Trichoderma species is a filamentous fungus that is widely distributed in the soil, plants material, decaying vegetation and wood. It is normally considered as a contaminant but may cause infections in presence of predisposing factors.

The taxonomic classification of Trichoderma is kingdom; Fungi, Phylum; Ascomycota, Order; Hypocreals, Family; Hypocreaceae and Genus; Trichoderma. The genus Trichoderma has 5 species namely;

The morphological features of the conidia and phialides help in differentiation of the species from one another. Other trichoderma species are Trichoderma asperelum, Trichoderma citrinoviride. Trichoderma species is a mould that lacks a known sexual state and therefore belongs to the Fungi Imperfecti. The telemorphs and synonyms of the genus are Aleurisma and pachybasium.

Aleurisma and pachybasium are obsolete synonyms of the genius. Like any other species, trichoderma species has pathogenicity and clinical significance although very few case if human cases have been identified. Their infections are opportunistic and develop in immmunocompromised patients. Examples include;

Trichoderma species have macroscopic features; its colonies grow rapidly and mature in 5days. At 25°C, and on potato dextrose agar, the colonies are wooly and become compact in time. Scattered blue-green or yellow-green patches become visible as the conidia are formed. They are more readily visible on potato dextrose agar than Sabouraud dextrose agar. The reverse is pale, yellowish or Tan.

The microscopic features that can be observed are Septate hyaline hyphae, conidiophores, phialides and conidia. Trichoderma longibrachiatum and Trichoderma viride may also produce chlamydospores. Conidiophores are hyaline branched and may occasionally display a pyramidal arrangement. Phialides are hyaline, flask-shaped and inflated at the base.

They are attached to the conidiophores at right angles. The phialides may be arranged in clusters. Conidia are one-celled and round or ellipsoidal in shape. They are smooth or rough-walled or grouped in sticky heads at the tips of the phialides. The clusters are frequently disrupted during routine slide preparation procedure for microscopic examination. The color of the conidia is mostly green.

Histopathologic feature is branching septate hyphae may be observed. Histopathology remains one of the major diagnosis tools in mycology. Its major advantages are high speed, low-cost and the ability to provide a presumptive identification of the infecting fungus. It also demonstrates the tissue reaction. It usually provides essential information before the fungus can be isolated in mycology biology.

Trichoderma species require no special precautions other than the general laboratory precautions. Very limited data on its susceptibility are available. Amphotecirin B and itraconazole microscopes may be elevated. Voriconazole exerts some activity in vitro against isolates of Trichoderma longibrachiatum. Other MIC's that appear promising are Posaconazole, caspofungine and anidulafungin.

Advantages of the species;