p.10
Pathogenesis of Fungal Infections
How do pathogenic fungi survive in the immune system?
They can survive and multiply slowly in nonactivated macrophages.
p.2
Structure and Components of Fungal Cells
What is a key component of the fungal cell structure that is not found in bacterial membranes?
Sterols, specifically ergosterols.
p.1
Definition and Characteristics of Fungi
How do fungi reproduce?
They can reproduce sexually or asexually.
p.21
Subcutaneous and Systemic Mycoses
Can subcutaneous mycoses spread to other parts of the body?
Yes, they can potentially spread to deeper tissues or organs.
p.18
Pathogenesis of Fungal Infections
What happens if Candida albicans is phagocytosed?
Hyphal growth interferes with lysosomal fusion and leads to the death of macrophages.
p.14
Pathogenesis of Fungal Infections
What initiates a dermatophyte fungal infection?
A minor traumatic skin lesion that comes into contact with dermatophyte hyphae.
p.30
Subcutaneous and Systemic Mycoses
What is the pathogenic cause of Rhinocerebral Mucormycosis?
Various species in the genera Mucor, Absidia, and Rhizopus.
p.14
Pathogenesis of Fungal Infections
How does inflammation affect dermatophyte infections?
It tends to increase skin growth and helps limit the infection.
p.14
Pathogenesis of Fungal Infections
What effect do immunosuppressive drugs like corticosteroids have on dermatophyte infections?
They decrease shredding of keratinized layers and tend to prolong the infection.
p.24
Pathogenesis of Fungal Infections
What is an example of a pathogenic fungus?
Candida albicans is an example of a pathogenic fungus that can cause infections.
p.27
Pathogenesis of Fungal Infections
What diseases can Cryptococcus neoformans cause?
Pneumonia and chronic meningitis.
p.17
Pathogenesis of Fungal Infections
What protein does Candida albicans use to attach to human epithelial cells?
Hyphal wall protein (Hwp 1).
p.22
Treatment Options for Fungal Infections
What are the treatment options for Sporothrix schenckii infection?
Itraconazole and Amphotericin B (for systemic disease).
p.11
Fungal Infections: Dermatophytes
What are common names for dermatophyte infections?
Ringworm, athlete’s foot, and jock itch.
p.1
Definition and Characteristics of Fungi
Are fungi unicellular or multicellular?
They can be either unicellular or multicellular.
What is dimorphism in fungi?
The ability of some fungi species to grow in either a yeast or a mold phase depending on environmental conditions.
At what temperature do fungi typically grow in mold form?
Ambient temperature, around 25 °C.
p.18
Pathogenesis of Fungal Infections
How do the hyphae surface proteins affect phagocytes?
They confuse the phagocyte’s ability to recognize C3b bound to the Candida surface.
p.3
Structure and Components of Fungal Cells
What are the properties of chitin?
Inert, insoluble, rigid, and provides structural support.
p.13
Treatment Options for Fungal Infections
What is a common topical treatment for fungal infections?
Terbinafine or azoles (miconazole, ketoconazole).
p.14
Pathogenesis of Fungal Infections
What factors influence the course of a dermatophyte infection?
Anatomical location, moisture, and dynamics of skin growth.
p.16
Fungal Infections: Candida albicans
What are common sites of infection for Candida albicans?
Skin, mucous membranes, urinary tract, and disseminated sites.
p.29
Pathogenesis of Fungal Infections
How is Coccidioidomycosis primarily transmitted?
Through inhalation (e.g., construction site, dust storm).
p.10
Pathogenesis of Fungal Infections
What happens to pathogenic fungi when macrophages are activated?
The growth of the fungi is restricted and they are digested.
p.23
Pathogenesis of Fungal Infections
What is Mycetoma?
A fungal infection associated with trauma to the foot.
p.2
Structure and Components of Fungal Cells
How do fungi obtain their carbon source?
They are heterotrophic and degrade organic substrates as an exogenous source of carbon.
p.2
Structure and Components of Fungal Cells
What is the polar bud scar in fungi?
It is the site of cytokinesis and septation.
p.3
Structure and Components of Fungal Cells
What are the main components of the fungal cell wall?
Glucans, mannan, and chitin.
p.23
Pathogenesis of Fungal Infections
What is a common characteristic of the grains associated with Mycetoma?
They can be black in color.
p.5
Structure and Components of Fungal Cells
What are hyphae?
Tube-like extensions of the cells with thick and parallel walls.
p.3
Structure and Components of Fungal Cells
How does the variation in mannan composition affect fungi?
It affects the serologic specificity due to variation in composition and linkages of polymer side chains.
p.30
Pathogenesis of Fungal Infections
How does Rhinocerebral Mucormycosis spread in the body?
Inhalation leads to spread from the nose or sinuses to the brain.
p.30
Subcutaneous and Systemic Mycoses
What does the arrow in the context of Rhinocerebral Mucormycosis indicate?
The necrosis of the palate.
p.27
Pathogenesis of Fungal Infections
What are the complex polysaccharides produced by Cryptococcus neoformans?
Glucuronoxylomannan (GXM) and glucuronoxylomannogalactan.
p.16
Fungal Infections: Candida albicans
What are the symptoms of vaginal thrush?
Painful urination, discomfort during sexual intercourse, and discharge.
p.22
Pathogenesis of Fungal Infections
What does melanin do in the context of Sporothrix schenckii infection?
Resists oxidative killing in tissues and macrophages.
p.22
Pathogenesis of Fungal Infections
What happens to the lesion if a Sporothrix schenckii infection is untreated?
The lesion will evolve into an ulcer.
p.10
Pathogenesis of Fungal Infections
What role do cytokines from T-cells play in fungal infections?
They activate macrophages, restricting fungal growth and aiding in digestion.
p.19
Other Superficial Mycoses
What is Pityriasis versicolor characterized by?
Discrete areas of hypopigmentation or hyperpigmentation with induration and scaling.
p.6
Structure and Components of Fungal Cells
What is a hypha?
A hypha is a long, branching filamentous structure of a fungus.
p.19
Other Superficial Mycoses
What type of skin discoloration is associated with Pityriasis versicolor?
Discoloration of skin, either hypopigmented or hyperpigmented.
p.7
Types of Fungi: Yeast and Mold
What do aerial hyphae produce?
Spores, serving as reproductive structures.
What is a characteristic of the mold form of fungi?
It requires minimal nutrients.
p.21
Subcutaneous and Systemic Mycoses
What are some symptoms of subcutaneous mycoses?
Localized swelling, ulceration, and drainage.
p.13
Fungal Infections: Dermatophytes
What are the symptoms of athlete's foot?
Cracking skin with a burning feeling.
p.9
Pathogenesis of Fungal Infections
What does invasion in fungal pathogenesis refer to?
Passing the initial surface barrier such as skin or mucous membranes.
p.16
Fungal Infections: Candida albicans
Where is Candida albicans commonly found in healthy individuals?
In oropharyngeal, gastrointestinal, and female genital microbiota.
p.9
Pathogenesis of Fungal Infections
What causes injury during fungal infections?
Mainly due to inflammatory and immunologic responses.
p.24
Pathogenesis of Fungal Infections
Can fungi be pathogenic?
Yes, certain fungi can be pathogenic and cause infections in humans, particularly in immunocompromised individuals.
p.16
Fungal Infections: Candida albicans
What risk factor is associated with Candida albicans infections?
Use of antibiotics, which kill lactobacillus.
p.17
Pathogenesis of Fungal Infections
What components of the extracellular matrix does Candida albicans bind to?
Fibronectin, collagen, and laminin.
p.17
Pathogenesis of Fungal Infections
What is the role of aspartic proteinases (Saps) in Candida albicans infection?
They digest keratin and collagen, favoring deep tissue invasion.
p.22
Pathogenesis of Fungal Infections
What is the initial lesion of a Sporothrix schenckii infection?
Pustular nodular lesion on the finger.
p.11
Fungal Infections: Dermatophytes
Which three genera are classified as dermatophytes?
Epidermophyton, Microsporum, and Trichophyton.
p.2
Structure and Components of Fungal Cells
What organelles are present in fungi?
Nucleus, mitochondria, endoplasmic reticulum, and ribosomes.
p.23
Pathogenesis of Fungal Infections
What causes Mycetoma?
Inoculation of various fungi species due to trauma.
p.7
Structure and Components of Fungal Cells
What is the function of vegetative hyphae?
They grow into the medium or organic substrate to collect nutrients and moisture, and anchor the mold.
p.23
Pathogenesis of Fungal Infections
What types of objects can cause trauma leading to Mycetoma?
Wood splinters and thorns.
p.13
Fungal Infections: Dermatophytes
What is a common symptom of hair infections?
Hair loss and superficial lesions.
p.3
Structure and Components of Fungal Cells
What role does mannan play in the fungal cell wall?
Mannan links to surface proteins (mannoproteins) and serves as major determinants of serologic specificity.
p.26
Fungal Infections: Dermatophytes
What are some pathogenic causes of Chromomycosis?
Fonsecaea compacta, Pilalophora verrucosa, Cladosporium carionii.
p.13
Fungal Infections: Dermatophytes
What are the signs of a nail infection?
Discolored, thickened, and fragile nails.
p.9
Pathogenesis of Fungal Infections
What can facilitate fungal invasion?
Mechanical break or trauma, along with extracellular enzymes like protease and elastase.
p.28
Pathogenesis of Fungal Infections
What happens if Cryptococcus neoformans is phagocytosed by macrophages?
It can survive and multiply, producing melanin to interfere with oxidative killing mechanisms.
p.27
Pathogenesis of Fungal Infections
What are the late symptoms of Cryptococcosis?
Seizures, cranial nerve signs, and papilledema.
p.29
Subcutaneous and Systemic Mycoses
What does disseminated Coccidioidomycosis cause?
Lesions in the bones, joints, skin, and progressive chronic meningitis.
p.11
Fungal Infections: Dermatophytes
What causes the ring-like lesions associated with ringworm?
Advancing growth of Trichophyton mentagrophytes.
p.7
Structure and Components of Fungal Cells
What are septa in molds?
Structures that can vary among species and may contain pores and incomplete walls, allowing movement of nutrients, organelles, and nuclei.
p.21
Subcutaneous and Systemic Mycoses
How do subcutaneous mycoses typically occur?
Through traumatic implantation of fungi into the skin.
p.21
Subcutaneous and Systemic Mycoses
What is a common cause of subcutaneous mycoses?
Fungi found in soil or decaying vegetation.
p.3
Structure and Components of Fungal Cells
What is the composition of chitin in fungal cell walls?
Long and unbranched chains of poly-N-acetylglucosamine.
p.9
Pathogenesis of Fungal Infections
What is the role of fungal adhesin in pathogenesis?
It interacts with host cell receptors to facilitate adherence.
p.14
Pathogenesis of Fungal Infections
What happens once the stratum corneum is penetrated by dermatophytes?
The organism can proliferate in the keratinized layers of skin, aided by proteases.
p.24
Pathogenesis of Fungal Infections
How do pathogens typically enter the host?
Pathogens can enter the host through various routes, including inhalation, ingestion, or through breaks in the skin.
p.27
Pathogenesis of Fungal Infections
What enzymes does Cryptococcus neoformans produce?
Urease, laccase, and melanin.
p.22
Pathogenesis of Fungal Infections
What areas can a Sporothrix schenckii infection spread to?
Bones, eyes, lungs, and central nervous system.
p.11
Fungal Infections: Dermatophytes
What tissues are dermatophytes highly adapted to?
Non-living, keratinized tissues of nails, hair, and stratum corneum of skin.
p.21
Subcutaneous and Systemic Mycoses
What are subcutaneous mycoses?
Fungal infections that occur beneath the skin.
p.26
Fungal Infections: Dermatophytes
What are the characteristics of lesions caused by Chromomycosis?
Scaly, wart-like pigmented lesions.
p.6
Structure and Components of Fungal Cells
What is the relationship between hyphae and mycelium?
Mycelium is composed of many hyphae intertwined together.
p.5
Structure and Components of Fungal Cells
What types of hyphae can molds produce?
Septate or non-septate hyphae.
p.24
Pathogenesis of Fungal Infections
What are pathogenic causes?
Pathogenic causes refer to microorganisms, such as bacteria, viruses, fungi, and parasites, that can cause disease.
p.27
Pathogenesis of Fungal Infections
How is Cryptococcus neoformans typically acquired?
Through inhalation from the environment.
p.22
Pathogenesis of Fungal Infections
What proteins does Sporothrix schenckii bind to?
Extracellular matrix proteins such as fibronectin, laminin, and collagen.
p.29
Subcutaneous and Systemic Mycoses
In which type of soil does Coccidioides immitis grow?
Alkaline soil of semiarid climates.
p.29
Pathogenesis of Fungal Infections
What are common symptoms of Valley fever?
Fever, malaise, dry cough, joint pain, and sometimes rash.
p.1
Definition and Characteristics of Fungi
How do fungi acquire nutrients?
Through absorption, as they lack chlorophyll.
p.6
Structure and Components of Fungal Cells
What is mycelium?
Mycelium is a network of hyphae that forms the vegetative part of a fungus.
p.6
Structure and Components of Fungal Cells
How do hyphae contribute to the growth of fungi?
Hyphae absorb nutrients and help in the spread of the fungus.
p.18
Pathogenesis of Fungal Infections
What do hyphae surface proteins of Candida albicans resemble?
Complement receptors (CR2, CR3) on phagocytes.
p.5
Structure and Components of Fungal Cells
What is the function of septa in hyphae?
To divide the hyphae into subunits.
p.24
Pathogenesis of Fungal Infections
What role do virulence factors play in pathogenicity?
Virulence factors are traits of a pathogen that enhance its ability to cause disease, such as toxins, adhesion factors, and immune evasion mechanisms.
p.28
Pathogenesis of Fungal Infections
How does Cryptococcus neoformans interfere with the immune response?
By interfering with antigen presentation and leukocyte migration.
p.28
Pathogenesis of Fungal Infections
Where can Cryptococcus neoformans spread after infecting the lungs?
It can spread to the brain.
p.27
Treatment Options for Fungal Infections
What are the treatment options for Cryptococcosis?
Amphotericin B, flucytosine, and an extended course of fluconazole.
p.11
Fungal Infections: Dermatophytes
What type of infections do dermatophytes cause?
Superficial infections of skin and its appendages.
p.29
Subcutaneous and Systemic Mycoses
What type of lesions are associated with pulmonary infection from Coccidioidomycosis?
Round or oval spots (lesions) in the lungs.
p.4
Structure and Components of Fungal Cells
What is the simplest form of yeast reproduction?
Formation of a bud (blastoconidia).
p.18
Pathogenesis of Fungal Infections
What does Candida albicans accelerate in its pathogenesis?
The degradation of surface complement C3b.
p.18
Pathogenesis of Fungal Infections
What does Candida albicans bind to or secrete to aid in its pathogenesis?
Serum factor H or its own protease.
p.9
Pathogenesis of Fungal Infections
What is the first step in the pathogenesis of fungi?
Adherence to the mucosal surface of gastrointestinal and female genital tracts.
p.13
Treatment Options for Fungal Infections
What systemic therapies are used for fungal infections?
Griseofulvin/itraconazole + oral terbinafine + topical therapy.
p.30
Pathogenesis of Fungal Infections
Who is at risk for developing Rhinocerebral Mucormycosis?
Patients with immune deficiencies or metabolic disorders.
p.28
Pathogenesis of Fungal Infections
What role does the capsule of Cryptococcus neoformans play in its pathogenesis?
It is antiphagocytic, leading to complement depletion and downregulation of cytokines.
p.16
Fungal Infections: Candida albicans
What localized diseases can result from Candida albicans?
Erythema and white plaques in moist skinfolds, oral thrush, and vaginal thrush.
p.16
Treatment Options for Fungal Infections
What are some treatment options for invasive Candida albicans infections?
Amphotericin B, fluconazole, and caspofungin.
p.17
Pathogenesis of Fungal Infections
What do the hyphae of Candida albicans secrete to facilitate invasion?
Proteinases and phospholipases.
p.22
Pathogenesis of Fungal Infections
How does a Sporothrix schenckii infection typically begin?
With a slow inflammatory process that follows lymphatic drainage from the original site.
p.29
Subcutaneous and Systemic Mycoses
Which regions in the US are associated with Coccidioidomycosis?
Arizona, Nevada, New Mexico, Western Texas, California.
p.11
Fungal Infections: Dermatophytes
How are dermatophyte infections transmitted?
Contact with intact or detached skin or hair.
