Microbio Exam 4: Important Fungi and Protozoans

What are fungi that invade keratinized tissue called?

Dermatophytes

What condition do dermatophytes lead to?

Dermatomycoses

What is ringworm scientifically known as?

Tinea

What are the types of Tinea infections?

Tinea corporis, T. cruris, T. capitis, T. unguium

How are Tinea infections typically transmitted?

Through unclean environments and fomites

What is the treatment duration for Tinea infections?

It may take many weeks

What secondary issue can arise from Tinea pedis?

A secondary bacterial infection

What is the most common nosocomial fungal infection?

Candidiasis caused by Candida albicans

What can Candidiasis cause?

Thrush, vaginitis, and tissue infections

What is Candida auris known for?

Being an emerging fungal infection causing worldwide concern

Why is Candida auris particularly concerning in hospitals?

It is highly resistant to antifungal drugs

What is vulvovaginal candidiasis primarily caused by?

Candida albicans

What factors can lead to vulvovaginal candidiasis?

Uncontrolled diabetes, change in pH, hormone change, and long-term antibiotic therapy

What protozoan causes trichomoniasis?

Trichomonas vaginalis

How is trichomoniasis transmitted?

Sexually

What areas does Trichomonas vaginalis infect?

The urogenital tract surfaces

Are many cases of trichomoniasis symptomatic?

Many cases are asymptomatic

What are T. hominis and T. tenax?

Normal commensals in the mouth and intestinal tract, respectively

What is Coccidioidomycosis commonly referred to as?

Valley Fever

What organism causes Coccidioidomycosis?

Coccidioides immitis

Where is Coccidioides immitis commonly found?

Southwest USA

What are the typical symptoms of Coccidioidomycosis?

Mild flu-like symptoms or no symptoms at all

What structure does Coccidioides immitis form in tissues?

Spherule

Who is at higher risk for complications from Coccidioidomycosis?

Immunocompromised people

What is Histoplasmosis caused by?

Histoplasma capsulatum

Where is Histoplasma capsulatum endemic?

Central and eastern US

What form does Histoplasma capsulatum take after inhalation?

Yeastlike form

How does Histoplasma capsulatum spread in the body?

Through macrophages

What are common sources of Histoplasma capsulatum exposure?

Caves and bird feces

What type of infection does Histoplasmosis usually cause?

Mild respiratory infection

What complications can arise from Histoplasmosis?

Pneumonia and infection in the spleen, liver, and lymph nodes

What is Pneumocystis pneumonia (PCP) caused by?

Pneumocystis jirovecii (carinii)

What type of cells does Pneumocystis pneumonia invade?

Lung cells

What are the symptoms of Pneumocystis pneumonia in healthy individuals?

Few or no symptoms

What can happen if Pneumocystis pneumonia spreads to other organs in immunocompromised individuals?

Complications can occur

What is the fatality rate of untreated Pneumocystis pneumonia infections?

High fatality rate

Which group of people is particularly affected by Pneumocystis pneumonia?

People with AIDS

How do people typically become infected with Blastomycosis?

Through a wound or by breathing in endospores

What organism causes Blastomycosis?

Blastomyces dermatitidis

What happens to the spores of Blastomyces dermatitidis after entering the body?

They mature to yeast cells

How can yeast cells from Blastomyces dermatitidis enter circulation?

Via macrophages

What can systemic blastomycosis lead to?

Extensive tissue damage

Is Blastomycosis primarily a skin infection or a respiratory infection?

More of a skin infection, but can be breathed in

Aspergillus fumigatus causes what

Aspergillosis

Aspergillus fumigatus infects

the lungs when the spores are inhaled

where are Aspergillus fumigatus spores found?

in decaying vegetation

Aspergillosis can become an invasive lung infection which leads to

asphyxiation

______ is another fungal infection that causes problems for people with AIDS or with an impaired immune system.

aspergillosis

What is the cause of Giardiasis?

Giardia duodenalis (intestinalis or lamblia)

How are cysts of Giardia duodenalis transmitted?

By drinking or eating cysts of the organism.

Where do Giardia cysts mature after ingestion?

In the small intestine.

What is the mature form of Giardia called?

Trophozoite

What symptom is commonly associated with Giardiasis?

Severe diarrhea with dehydration

How can Giardia cysts be effectively cleared from water?

By using a filtering system or boiling.

What causes Amebiasis (Amebic Dysentery)?

Entamoeba histolytica

What can happen if Entamoeba histolytica invades the intestinal mucosa?

It can enter the bloodstream and cause peritonitis.

Are cysts of Entamoeba histolytica killed by normal chlorine concentrations in water?

No, they are not killed.

What is a characteristic of Cyclosporiasis?

It leads to watery diarrhea.

What organism causes Cyclosporiasis?

Cyclospora cayetanensis

What is a common source of Cryptosporidiosis?

Contaminated water

What are the two main species of Cryptosporidium that infect humans?

C. hominis and C. parvum

What can happen to immunodeficient individuals infected with Cryptosporidium?

They can experience life-threatening diarrhea.

What disease is spread by a sand fly bite and is common in the tropics?

Visceral Leishmaniasis

What organism causes Visceral Leishmaniasis?

Leishmania donovani

What type of cells ingest the Leishmania donovani protozoan?

Macrophages

What happens to the liver, spleen, and kidneys if Visceral Leishmaniasis is left untreated?

Extensive damage can occur, leading to death.

What is the relationship between Visceral Leishmaniasis and HIV?

It is becoming an opportunistic infection associated with HIV.

What disease is endemic in tropical areas and is transmitted by mosquitoes?

Malaria

What stage of the malaria protozoan enters the human bloodstream from the mosquito?

Sporozoite stage

Where does the sporozoite stage of malaria travel to after entering the bloodstream?

The liver

What stage does the malaria protozoan enter after maturing in the liver?

Merozoite stage

What happens to the liver cells infected by the malaria protozoan?

They rupture, releasing merozoites.

What is the name of the stage when merozoites invade red blood cells?

Trophozoite stage

What is the effect of the periodic rupture of red blood cells in malaria?

It releases new merozoites and causes a rise in body temperature.

What genetic trait provides protection against malaria?

Sickle cell trait

How many species of Plasmodium are there?

Four species

Which species of Plasmodium is the most pathogenic?

Plasmodium falciparum

What severe condition can Plasmodium falciparum cause?

Blood vessel obstruction

What drug is Plasmodium falciparum becoming resistant to?

Chloroquine

How is Plasmodium falciparum best controlled?

Controlling the mosquito population with pesticides

What has been developed through genetic manipulation to combat Plasmodium?

A mosquito resistant to infection

What is the goal of introducing genetically modified mosquitoes into the wild?

To mate with wild-type mosquitoes and reduce the population's ability to support Plasmodium infection

What is the name of the vaccine available for children against malaria?

Mosquirix

What is a challenge in developing a vaccine for Plasmodium?

Identifying the stage of the organism that provides protection

What leads to symptoms in malaria caused by Plasmodium?

Blood cell rupturing

What is essential for the survival of Plasmodium?

Mosquitoes

What occurs in the mosquito that is crucial for Plasmodium's life cycle?

The sexual stage of the organism

How do young children develop immunity to malaria?

They acquire some immunity on their own

What causes Chagas' Disease?

Trypanosoma cruzi

What are the initial symptoms of Chagas' Disease?

Fever and swollen glands

What organs can be damaged in the chronic form of Chagas' Disease?

Heart, skeletal muscles, and colon

Can Chagas' Disease be transmitted from a pregnant woman to her fetus?

Yes

Why is it difficult to treat Chagas' Disease in its chronic stage?

The trypanosome can multiply inside host cells

What causes Toxoplasmosis?

Toxoplasma gondii

Where can Toxoplasma gondii be found?

In the feces of cats as oocysts

How can humans become infected with Toxoplasma gondii?

By eating undercooked contaminated meat

What is a common symptom of Toxoplasmosis?

Mild lymph node inflammation

Can Toxoplasma gondii cross the placenta?

Yes

What group of people is particularly affected by Toxoplasmosis?

Pregnant women and immunocompromised individuals

Is there ongoing research regarding Toxoplasma gondii and schizophrenia?

Yes, there is research on a potential connection