Mycology is the branch of biology that deals with the study of fungi. Fungi are a part of the natural environment and exist as saprophytes in nature. However, there are certain species that remain as normal flora in an immunocompetent host but are capable of causing opportunistic infections in an immunocompromised host.
Mycology includes the study of the structure, classification of various types of fungi, and also the pathogenesis, clinical manifestations, and laboratory diagnosis of fungal infections.
In person with invasive aspergillosis, there may be high titers of galactomannan antigen in serum and bronchoalveolar lavage (BAL) fluid.
Mycoses can be classified based on the site of the infection, route of acquisition of the pathogen, and type of virulence exhibited by the fungi.
Candida auris causes a serious and sometimes fatal fungal infection that is emerging globally. Identification of C. aurius is challenging.
Mucormycosis caused by Mucorales can be diagnosed by histopathological examination with or without isolation of the fungus from the same site.
Mucormycosis (zygomycosis, phycomycosis) is caused by saprophytic molds (e.g., Mucor, Rhizopus, and Absidia).
Hair, nail clippings, skin scrapings, blood, CSF, and sputum are the most common clinical specimens.
Dermatophyte test medium (DTM) is a specialized selective and differential fungal cultures medium to isolate and identify dermatophytes.
Blastomyces dermatitidis is a thermally dimorphic fungus and causes blastomycosis. Single broad-based bud in a clinical sample is diagnostic.
Slide-culture is a rapid method of preparing fungal colonies for examination and identification with little disturbance as possible.
Pneumocystis jirovecii is an opportunistic atypical fungal pathogen which does not respond to conventional anti-fungal agents.
Detection of specific antigens present in the sample (blood, urine, or CSF) using specific antibodies is the mainstay for the rapid diagnosis of infections.
Aspergillus fumigatus is a mold with a septate hyphae with acute angle branching. It causes infections of the skin, eyes and ears; fungus ball in the lungs.
Culture, direct microscopy, and histopathology are mostly used methods for the diagnosis of fungal infections.
Bird Seed Agar is a solid medium used for selective and differential isolation of Cryptococcus neoformans from clinical specimens.
Histoplasma capsulatum is an intracellular, thermally dimorphic fungi. It causes systemic mycoses called histoplasmosis.
Cryptococcus neoformans is an opportunistic fungal pathogen (yeast) responsible for causing cryptococcal meningitis.
KOH preparation is used for the rapid detection of fungal elements in clinical specimens but it may not necessarily identify the species of the fungi.
Causative agents of Candidiasis, Candida albicans is a gram-positive yeast cells. It gives positive germ-tube test.
Germ tube is a short hyphal extension arising laterally from a yeast cell with no constriction at the point of origin.
Originally formulated for dermatophyte growth and pigment production, SDA is used for growth and maintenance of fungi.
Potato Dextrose Agar (PDA) is an ideal medium for slide culture preparation. It promotes sporulation of moulds.
Lactophenol cotton blue solution is a mounting medium and staining agent used in the preparation of slides for microscopic examination of fungi.
Fungal culture media contains high carbohydrate and nitrogen source. They may also contain cycloheximide and antibacterial agents to inhibit contaminants.
Sporotrichosis is a chronic infection of subcutaneous tissues caused by a dimorphic fungus, Sporothrix schenckii.
Dimorphic fungi exist as molds in the environment at ambient temperature and as yeasts in human tissues at body temperature.