prions.worms etc

How do anti-fungal medications exert their effects?

interfere with DNA/RNA synthesis, disrupt microtubules and mitochondria, affect membrane structure

What are the fungi lifestyles?

Saprobic (feed on dead matter) and parasitic and mutualistic symbionts.

What are unicellular fungi called?

Yeasts

4. What are multi-cellular fungi called?

Moulds (mycelium with hyphae)

Main infectious fungi:

• Moulds: Aspergillus, Mucor

• Yeasts: Candida, Cryptococcus

  • Dimorphics: Histoplasma, Coccidioides, Blastomyces

Define saprobe:

Organism that feeds on dead or decaying organic matter.

7. Define dissemination (or disseminated):

Spread of infection from initial site to other parts of the body.

What does dimorphic mean? Give an example of a dimorphic fungus:

• Can exist as yeast in body temperature and mould in environment. Example: Histoplasma capsulatum.

Factors that determine virulence:

ability to adhere, Host immunity, fungal enzymes, spore production, produce enzymes, ability to switch forms

what causes Athlete’s foot: what are the symptoms and risk factors

• dermatophytes (tinea pedis)

• Symptoms: itching, scaling, redness, cracking

• Risk factors: moist environments, communal showers, tight footwear

Candida infections:

• Cutaneous: skin, nails, diaper rash

• Mucosal: mouth, vagina, esophagitis

• Disseminated: blood, organs, brain, eye

General symptoms for a respiratory fungal infection:

Cough, fever, shortness of breath, chest pain

General symptoms for a cutaneous fungal infection:

• Rash, itching, redness, scaling

Coccidioides immitis: portal of entry and incubation period. what is the diease?

• Portal of entry: inhalation of spores

• Incubation time: 1–4 weeks

• Disease: Valley Fever

where is Aspergillus found? where does it infect?

• Environment: soil, decaying vegetation

• Infection site: lungs, sinuses, immunocompromised patients

what infection is caused by Diplomonads? source? symptoms?

• Infection: Giardia

• Source: contaminated water

• Symptoms: diarrhea, abdominal cramps, nausea

what infection is caused by Parabasalids? source? symptoms?

• Infection: Trichomonas vaginalis

• Source: sexual transmission

• Symptoms: vaginal discharge, itching, irritation

Insect vector for Trypanosoma:

• Africa: tsetse fly

• America: triatomine bug

Life cycle of Trypanosoma:

fly takes blood meal—parasite multiplies in gut—migrates to salivary glands—injected into hose—multiplies in blood/lymph/CNS

Symptoms of trypanosomiasis:

Fever, fatigue, swollen lymph nodes, neurological symptoms

areas affected by Leishmaniasis:

Symptoms: skin ulcers, hepatosplenomegaly, fever

cutaneous: skin sores

visceral: spleen, liver, bone marrow

mucosal: nose, mouth throat

7. Insect that transmits malaria:

Anopheles mosquito

Malaria plasmodium in human host:

Liver first, then red blood cells

Symptoms of malaria:

Cyclical fever, chills, sweating, anemia

Source for toxoplasmosis: symptoms

• Cat feces, undercooked meat

• Symptoms: flu-like, may affect fetus

Infectious agent of a prion:

Misfolded proteins

Area of brain affected by BSE:

Brainstem in cattle

Area of brain affected by CJD:

Cerebral cortex in humans

Source of infection with Kuru:

Cannibalism of infected human brain tissue

Source of infection with BSE (mad cow disease):

Cattle feed containing infected tissue

Symptoms of CJD:

Dementia, ataxia, myoclonus; Symptoms of BSE: neurological signs, motor dysfunction

Chronic wasting disease spread and symptoms:

• Spread: direct contact, contaminated environment among deer/elk

• Symptoms: weight loss, behavioral changes, poor coordination

1. Characteristics of parasitic worms:

• Multicellular, host-specific, complex life cycles, may have attachment structures

Body structure of a cestode tapeworm:

Segmented body (proglottids), head (scolex) with hooks and suckers

Transmission of tapeworms and flukes:

• Tapeworms: ingestion of larvae in undercooked meat

• Flukes: contaminated water, snails as intermediate hosts

Types of hosts infected by trematodes (flukes):

Humans, animals; often require intermediate snail host

Body organs flukes seek out:

Liver, lungs, blood vessels, intestines

Tissue Ascaris nematode infects:

Intestinal lining, migrates through lungs

Life cycle of hookworms and food source:

• Larvae penetrate skin → lungs → intestines; feed on blood from intestinal mucosa

Where does Loa loa infect:

Subcutaneous tissue; vector: deer fly