Infectious Agents: Bacteria, Viruses, Fungi, Protists, and Helminths

What are bacteria?

Living, microscopic, unicellular, prokaryotic organisms.

What are viruses?

Non-living microscopic agents made of an outer protein shell called a capsid and either DNA or RNA.

What are fungi?

Living multicellular, eukaryotic organisms that include yeasts, mildews, molds, and mushrooms.

How can bacteria be contracted?

Through the nose, eyes, mouth, wounds, or contaminated food or water.

How can viruses be contracted?

Through touch, saliva, blood, or sexual contact.

How can fungi be contracted?

By inhaling spores or having them land on a host.

What damage can bacteria cause to the host?

They can invade cells, cause tissue damage, and produce harmful toxins.

How are bacterial infections diagnosed?

Through a physical exam and lab testing.

How are viral infections diagnosed?

Through physical exams and lab testing.

How are fungal infections diagnosed?

Through microscopic examination of tissue or blood from the infected area.

What is one way to treat bacterial infections?

Using antibiotics.

How can viral infections be treated?

Over-the-counter medications can relieve symptoms, but they do not treat the virus itself.

What is a common treatment for fungal infections?

Antifungal medications.

What is an example of a bacterial agent?

Mycobacterium tuberculosis, which causes TB.

What is an example of a viral agent?

The influenza virus.

What is an example of a fungal agent?

Tinea pedis, which causes athlete's foot.

What are protists?

Living microscopic single-celled eukaryotic organisms.

What are helminths?

Living multicellular eukaryotic worms, which can be microscopic or macroscopic.

How can protists be contracted?

By ingestion of contaminated food or water.

How can helminths be contracted?

Through consumption of contaminated foods or water, or bites from infected insects.

What damage can helminths cause to the host?

They can deprive the host of essential nutrients and cause organ and tissue damage.

How are protist infections diagnosed?

By microscopic examination of fecal material.

How are helminth infections diagnosed?

By microscopic examination of fecal material or through deworming medication.

What is an example of a protist?

Giardia lamblia, which causes giardiasis.

What is an example of a helminth?

Taenia, which is a type of tapeworm.