Descriptions and natural habitats
Paecilomyces is a filamentous fungus found throughout the world, living on soil, corrosive plants and food products. Some species have been isolated from insects. Telomorphs of this fungus are classified in the genus Byssochlamys, Chromocleista, Talaromyces and Thermoascus. Paecilomyces are usually considered as contaminants, but they can also infect humans and animals.
The genus Pecilomyces includes several species. The most common are Paecilomyces lilacinus and P.variotii. Color of colonies and some microscopic features help differentiate species. Another feature that helps identify species is the thermometric method. Paecilomyces crustaceus and P.variotii are thermophilic and can grow at temperatures up to 50 ° C and possibly 60 ° C.
Pathogenicity and medical importance
Paecilomyces species can cause various infections in humans. This infection is sometimes referred to as paecilomycosis. Corneal ulcer, keratitis and endophthalmitis may be caused by the use of lens or eye surgery due to these microorganisms. This fungus is one of the opportunistic germs in cases of defective host immunization. Its direct tangles to the skin may lead to infection. Paecilomyces may affect almost every organ in the human body. Soft tissue, lung and skin infections, cellulitis, anichumixemia, sinusitis, otitis media, endocarditis, localized and malignant bone inflammation, peritonitis, and many others. this fungus species can also cause allergic disorders such as allergic alveoliitis.
Paecilomyces colonies grow fast and mature within 3 days. P.crustaceus and P. variotii are thermophilic and can grow at temperatures up to 50 ° C and possibly 60 ° C. Psilomyces colonies are flat, powdery or velvety in the tissue. The color of the mushroom is initially white and then yellow, yellow, green, yellow and brown, apricot brown, pink or purple (depending on the species) changes. The back of the cultivating plate is dirty, marshy or brown in color. Some species have aromatic aromas, and this is probably related to the culture medium and the nutrients they feed on.
The paecilomyces hyphae are bright and wally and contain conidiaphore, fialide, konidia and chlamydospore. Conidiofores (3-4 mm wide and 400-600 μm long) are often branched and carry phialides at their tips. The phials swell in their bases and reach the top. They are usually placed in pairs or clusters like a brush. Whether it’s a cell, bright to dark, smooth or rough, oval to bulk and forms in long chains. Chlamydospores are sometimes present.
Ascumata, Asc and Ascospores are produced by telomorphic species such as Hermoascus crustaceus.
The wall hinges may be seen.
Comparison of Psilomyces with Penicillium
The phalides in the Paecilomyces are mainly swollen and narrow to the tip and separate from each other. On the other hand, Penicillium phyllides have thicker tips and are organized in tight clusters. Penicillium colonies are usually blue and green, while Paecilomyces colonies are not.
No special precautions other than general laboratory precautions are required.
Very limited information is available in this regard, and this information is about the species P. fumosoroseus, P. javanicus, P. lilanicus, Paecilomyces marquandii and P. variotii. MICs of amphotericin B are low in strains of P. lilanicus. On the other hand, MICs are very much fluoxetine, except in the strain of P.variotii. Fluconazole levels have significant MICs in all tested species. The values of interaconazole and ketoconazole MIC in P.variotii are lower than other species. Voriconazole has been tested in P. lilanicus and P. variotii, and the MICs in these two species of Paecilomyces are significantly low. Posazonazole, the triazole novel UR-9825 and terbinafine, appear to be produced in active strains cultivated in a test site. On the other hand, Caspofungin is active in the cultivation of P. variotii, but does not have significant activity against Paecilomyces lilanicus.
Despite the high MICs in the laboratory, the combination of amphotericin B and flucytosin was successfully used in the treatment of Psycalomycosis by P. lilanicus fungus. Caspofunction, in combination with itraconazole, has also been successful in treating P. lilanicus infected specimens.