Mic 541 Exam 4 - Mycology I And II

subcutaneous mycosis - under the skin
generally introduced by trauma
found in soil, decaying vegetation
most common in agricultural workers, gardeners

Sporotrichosis is a fungal infection caused by the fungus Sporothrix schenckii. It is commonly treated with antifungal medications, such as azoles. Itraconazole is a newer azole that has been found to be effective in treating Sporotrichosis. Therefore, the statement that treating Sporotrichosis caused by Sporothrix schenckii with newer azole, such as itraconazole, is true.

Cryptococcosis is a fungal infection that primarily affects the lungs and central nervous system. In some cases, it can spread to the brain and cause symptoms that resemble those of a brain tumor, abscess, or multiple sclerosis (MS). This is because the infection can lead to the formation of lesions or masses in the brain, which can be mistaken for other conditions on imaging tests. Therefore, it is true that cryptococcosis may mimic brain tumor, abscess, or MS.

Cutaneous Mycoses are fungal infections that affect the skin, hair, and nails. They are commonly known as tineas or ringworms. These infections are caused by various types of fungi and can be transmitted through direct contact with an infected person or animal, or by coming into contact with contaminated objects or surfaces. The term "ringworm" refers to the characteristic ring-shaped rash that often appears on the skin during these infections. Therefore, the statement that Cutaneous Mycoses are also called tineas or ringworms is true.

Opportunistic fungi are classified as those that only infect compromised hosts. These hosts have a weakened immune system or other underlying health conditions that make them more susceptible to fungal infections. Opportunistic fungi take advantage of this vulnerability to cause infections that they would not normally be able to cause in healthy individuals. Therefore, the correct answer is "opportunistic."

Infections from fungi can occur due to various reasons. Disruption of natural barriers, such as a weakened immune system or damage to the skin, can make it easier for fungi to enter the body and cause an infection. Immunosuppression, which refers to a weakened immune system, can also increase the risk of fungal infections as the body's ability to fight off pathogens is compromised. Additionally, occupational contact with certain fungi, such as those found in soil or contaminated materials, can also lead to infections. Therefore, all of the mentioned factors can contribute to the occurrence of fungal infections.

ergosterol can be targeted to alter permeability
drugs must not inhibit cholesterol as well

Echinocandins are a type of antifungal medication that is effective against Candida, a type of fungus that can cause infections in humans. Additionally, echinocandins also have activity against Aspergillus, another type of fungus. Therefore, the statement that echinocandins act as a fungicidal for Candida and also work against Aspergillus is true.

uncommon in children
primarily in adults who wear shoes
chronic infection of toe webs, soles
fluid-filled lesions dry to itch, crack, peel

A diaper rash is a common skin condition that occurs in infants and young children. It is typically caused by a yeast infection known as candidiasis. Candidiasis is a fungal infection that can occur in warm and moist areas of the body, such as the diaper area. The infection causes redness, irritation, and discomfort in the affected area. Therefore, the statement "A diaper rash is also known as a candidiasis infection" is true, as candidiasis is one of the main causes of diaper rash.

most cases asymptomatic to mild
resolve spontaneously and confer resistance

Nystatin is indeed a polyene similar to Amphotericin B. Polyenes are a class of antifungal drugs that work by binding to the fungal cell membrane and causing it to become permeable, leading to cell death. Nystatin and Amphotericin B both have a similar structure and mechanism of action, making them effective against a wide range of fungal infections. Therefore, the statement "Nystatin is a polyene similar to Amphotericin B" is true.

Fungi that infect only the outside layers of the skin or hair are classified as superficial. This means that the infection is limited to the surface of the body and does not penetrate deeper into the tissues. Superficial fungal infections are typically less severe and easier to treat compared to infections that affect deeper layers of the skin or internal organs.

Thiazoles and imidazoles are both types of organic compounds that contain a five-membered ring. They have similar side effects (SE) but thiazoles are less toxic compared to imidazoles. This means that thiazoles are likely to have fewer adverse effects or harmful reactions in the body compared to imidazoles. Therefore, the statement that thiazoles have the same side effects but are less toxic than imidazoles is true.

Fluconazole is used to treat meningitis because it can reach high levels in the central nervous system (CNS). Meningitis is an infection that affects the membranes surrounding the brain and spinal cord, and it requires medication that can effectively penetrate the CNS to combat the infection. Fluconazole is an antifungal medication that is able to cross the blood-brain barrier and reach therapeutic concentrations in the CNS, making it an effective treatment option for meningitis caused by certain fungal infections.

Dermatophytes are a common label for a group of three types of fungus that commonly causes skin disease in animals and humans. Dermatophytes cause infections of the skin, hair and nails.

Sporotrichosis is a subcutaneous mycosis that is commonly known as "rose-handler's" disease. It is caused by the fungus Sporothrix schenckii and is often contracted through handling thorny plants, such as roses. The infection typically starts at the site of injury and spreads along the lymphatic system, resulting in nodules or ulcers on the skin. This condition is not associated with the other options listed, which are different types of fungal infections that affect other parts of the body.

Cryptococcus neoformans is the only medically important encapsulated yeast that is not dimorphic. Dimorphism refers to the ability of a fungus to exist in two different forms, typically a mold form and a yeast form. Both Histoplasma capsulatum and Coccidioides immitis are dimorphic fungi, meaning they can exist as molds in the environment and as yeast in the human body. Cryptococcus neoformans, on the other hand, is a yeast-like fungus that does not undergo a mold phase. It is known for causing serious infections, particularly in individuals with weakened immune systems.

The statement suggests that there is a limit to the amount of Amphotercin that a person can receive throughout their lifetime. This implies that there is a restriction or maximum dosage of this drug that can be administered to an individual. Therefore, the correct answer is true, indicating that there is indeed a limit to the amount of Amphotercin a person can receive in their lifetime.

Fungi that are more virulent and cause disease in healthy hosts are classified as systemic. Systemic infections occur when the fungi invade and spread throughout the body, affecting multiple organs and systems. These infections are typically more severe and can be life-threatening. In contrast, superficial, cutaneous, subcutaneous, and opportunistic infections are generally limited to specific areas of the body or occur in individuals with weakened immune systems.

Relatively few cause human disease
Healthy humans have innate resistance

The given correct answer states that all of the options provided are true regarding Cryptococcosis Treatment. This means that Cryptococcosis Treatment is not usually needed for pulmonary infection, it is mandatory for meningitis, and it involves the administration of Amphotericin B intravenously with or without 5-flurocytosine. Additionally, it mentions that in some cases, the treatment can be switched to oral azole.

Fungi that enter the body through localized trauma, such as a cut or wound, are classified as subcutaneous. This means that they infect the layers of skin beneath the surface, causing infections that are deeper than superficial or cutaneous infections. Subcutaneous fungal infections can be caused by various types of fungi and typically require medical treatment to resolve.

Tinea corporis is a fungal infection that affects the skin and is commonly known as ringworm. It typically appears as circular or ring-shaped lesions on the body, hence the name "ringworm." These lesions are often red, itchy, and scaly, and may have a raised border. Tinea corporis can occur on any part of the body, including the arms, legs, trunk, and face. It is highly contagious and can be transmitted through direct contact with an infected person or animal, or by sharing contaminated items such as towels or clothing.

Fungi that invade the skin, hair, and nails are classified as cutaneous. Cutaneous refers to anything related to the skin, so it makes sense that fungi that infect these areas would fall under this classification. Superficial refers to something on or near the surface, but it doesn't specifically indicate the skin. Subcutaneous refers to something beneath the skin, so it doesn't accurately describe fungi that infect the skin. Systemic refers to something affecting the entire body, which is not the case for these fungi. Opportunistic refers to infections that occur when the immune system is weakened, but it doesn't specifically describe fungi that invade the skin, hair, and nails.

people inhale spores when dust is stirred up

5-fluorocytosine is the correct answer because it is a drug that fungi can take up using a permease that our cells do not make. Once inside the fungal cells, 5-fluorocytosine is converted into 5-fluorouracil, which gets incorporated into the fungal RNA in place of uracil. This disrupts the normal functioning of the fungal cells and inhibits their growth.

Amphotericin is an antifungal drug that binds to ergosterol in the fungal membrane. Ergosterol is a key component of the fungal membrane, and by binding to it, Amphotericin disrupts the integrity of the membrane. This disruption leads to the formation of pores in the membrane, which ultimately causes the death of the fungal cell. Therefore, Amphotericin is an effective antifungal agent that targets the fungal membrane and disrupts its structure.

5-fluorocytosine is the correct answer because the statement mentions that the fungal cells can develop resistance to *this drug* if given by itself. This implies that the drug being referred to is 5-fluorocytosine. Additionally, it is mentioned that 5-fluorocytosine is usually given in combination with Amphotericin B, further supporting the correctness of the answer.

Tinea capitis is mostly seen in children before puberty. This is a fungal infection that affects the scalp and hair follicles, causing symptoms such as itching, redness, and hair loss. It is more common in children due to their close contact with others in schools and daycare centers, as well as their underdeveloped immune systems. Tinea corporis, tinea unguium, and tinea cruris are fungal infections that typically affect the body, nails, and groin area, respectively, but they are not predominantly seen in children before puberty.

it does NOT have a capsule!

Cryptococcosis is the hallmark infection of AIDS patients

oral + topical needed

The correct answer is the azoles. The azoles are a class of antifungal drugs that inhibit cytochromes (cytochrome P450), which prevents the formation of ergosterol. Ergosterol is an essential component of fungal cell membranes, and its disruption leads to membrane dysfunction and inhibits fungal growth. Amphotericin, 5-flurocytosine, terbinafine, and capsofungin are other antifungal drugs, but they do not specifically inhibit cytochromes or prevent ergosterol formation.

Caspofungin is the correct answer because it inhibits β-(1,3)-D-glucan synthesis, which is responsible for making the cross-bridges in the fungal cell wall. By inhibiting this process, caspofungin prevents the formation of the fungal cell wall, leading to cell wall disruption and ultimately inhibiting the growth of the fungus.

Fungi reproduce through multiple methods. Fission, as in bacteria, refers to the process of a single organism splitting into two identical organisms. Budding, mostly seen in yeasts, involves the formation of a small outgrowth or bud that eventually separates from the parent organism to become a new individual. Fragmentation of hyphae occurs when the hyphae, which are the thread-like structures of fungi, break into fragments that can grow into new individuals. Spore formation is a common method among mold forms, where specialized cells called spores are produced and dispersed to give rise to new fungal individuals.

tinea corporis – NON-hairy body parts
tinea unguium – nails

5-fluorocytosine is a good drug for fungal meningitis because it has the ability to enter the central nervous system (CNS). This is important because fungal meningitis affects the membranes surrounding the brain and spinal cord, and the drug needs to be able to reach these areas to effectively treat the infection.

Terbinafine is the correct answer because it is known to block the squalene epoxidase enzyme, which is responsible for converting squalene to ergosterol. By inhibiting this enzyme, terbinafine prevents the synthesis of ergosterol, an essential component of the fungal cell membrane. Without ergosterol, the fungal cell membrane becomes unstable and leads to the death of the fungus. Therefore, terbinafine is an effective antifungal drug for treating fungal infections.

The azoles can have the mentioned side effects. This class of antifungal drugs can cause hormonal imbalances in males, leading to the development of breasts. In females, it can disrupt the normal menstrual cycle, resulting in irregular periods. Additionally, the azoles have been associated with liver toxicity, which can manifest as liver damage or dysfunction. Therefore, the azoles are the most likely antifungal drugs to cause these specific side effects.

Terbinafine is a medication that can be administered orally or topically. It is commonly used to treat dermatophytes, which are fungal infections that affect the skin, hair, and nails. Terbinafine is particularly effective in treating nail infections caused by fungi. Therefore, all of the given characteristics are true for terbinafine.

Pityriasis Versicolor is a chronic infection that affects the superficial layers of the skin. It is characterized by hypo- or hyperpigmented scaly lesions. This condition can be treated using keratinolytic agents such as salicylic acid, which helps to remove the outer layer of dead skin cells. Additionally, topical imidazoles like miconazole can also be used to treat Pityriasis Versicolor.

Amphotericin is a medication that disrupts the cell membrane, making it more permeable. This increased permeability affects the movement of ions, including magnesium (Mg) and potassium (K). Therefore, the correct answer is Mg and K.

voriconazole is a triazole
ketoconazole is used orally for dermatophytes, Candida, and some systemic infections

topical treatment usually lasts 2-4 weeks

treatment should continue 1-2 weeks after it has cleared up