Introduction to Mycology

Endemic in Southeast Asia, specifically Thailand, Southern China, and Hong Kong.

Rarely infects healthy immune systems.

Fungal communities forming layers on surfaces, often including capsules.

A protective layer surrounding some fungi that makes them resistant.

Fungi existing in multiple forms (shapes).

Ability to grow at human body temperature (37°C).

Melanin within fungal cell walls provides resistance to phagocytosis.

Certain fungi resist the body's defense mechanism (oxidative burst).

A fungal infection caused by Histoplasma capsulatum.

Fungal infection caused by Paracoccidioides brasiliensis.

Fungal infection caused by Sporothrix schenckii.

Fungal infection caused by Talaromyces marneffei.

Fungi that can exist in two forms (mycelial and yeast/spherule) in the host.

The spread of an infection from the lungs to other parts of the body.

Jobs may increase the exposure risk to certain fungi.

Fungal proteins helping fungi adhere to cells.

The ability of fungi to penetrate tissues in the human body.

Risk factors include: immune deficiencies (e.g., HIV/AIDS, diabetes) and certain occupations.

The process by which a fungus changes its form, for example, from a mold to a yeast.

A fungal infection caused by pigmented fungi, often characterized by dark yeast-like forms.

A common commensal yeast that can become pathogenic and assume various forms, including yeast, pseudohyphae, and true hyphae, during tissue invasion.

A dimorphic fungus that exists as filamentous molds in the environment but converts to endosporulating spherules in the human host.

'Grains' are masses of fungal hyphae, which are thread-like structures that make up the body of a fungus. They can sometimes clump together in infectious lesions.

Madura foot is a fungal infection of the foot, often caused by Scedosporium or Madurella species, that forms 'grains', leading to swelling, pain, and disfigurement.

Endemic mycoses, caused by dimorphic fungi, are more prevalent in tropical and subtropical areas of the world due to factors like climate and environmental exposure.

Dimorphic fungi can exist in two distinct forms: one adapted to the environment (mold) and the other adapted to living inside a host (yeast).

Individuals typically acquire endemic mycoses through inhalation of fungal spores, which are tiny particles released by fungi.

Initially, endemic mycoses often present with flu-like symptoms, such as fever, cough, and muscle aches. This can progress to pneumonia.

Individuals with weakened immune systems, such as those undergoing organ transplantation, receiving chemotherapy, or living with HIV/AIDS are at higher risk of developing severe fungal infections.

Prolonged exposure to certain environments, like ICU settings or areas where specific fungi are prevalent, can elevate the risk of fungal infection.

Invasive procedures, such as abdominal surgery, prosthetic implants, and indwelling catheters, can create entry points for fungi to infect the body.

Very young (<1 month) and older (>65 years) individuals have a higher risk of developing severe fungal infections.

Bacteria possess a single chromosome not enclosed by a membrane, located in the nucleoid region of the cytoplasm.

Bacteria have 70s ribosomes (30s + 50s subunits) while fungi have 80s ribosomes (40s + 60s subunits).

Some fungi can exist in two distinct forms: yeast and mold.

Most fungi require oxygen (aerobic) during human infections, but some can survive in low oxygen conditions (anaerobic).

Fungi use mitochondria for energy production, in contrast to bacteria which use their cell membrane.

These fungal infections affect the outermost layer of the skin, often causing conditions like pityriasis versicolor or dandruff.

These fungal infections affect deeper skin layers and are commonly known as 'ringworm', caused by Trichophyton and Microsporum species.

Rhizopus species (e.g., Rhizopus oryzae) cause Mucormycosis, a serious fungal infection, particularly in individuals with diabetic ketoacidosis.

Antibiotics generally target bacteria, while antifungals target fungi. However, similarities between fungal and human cells make developing effective antifungals challenging.

The close similarities between fungal and human cells make it difficult to create antifungal drugs that only target fungi without harming human cells.