In this lesson, you’ll explore a type of protist, known as a pathogenic protist, that can live inside another organism and cause it harm. You’ll also examine specific types of pathogenic protists, how they enter humans, and the damage they can cause.
What Are Pathogenic Protists?
Imagine that you had a small organism that lived inside you and called you home. This organism might travel around your body and cause you harm. This might sound like a nightmare that someone made up, but it is real.
Pathogenic protists are single-celled organisms that cause diseases in their hosts. These types of protists enter a host, such as an animal or plant, and live within the organism. While inside the organism, the protist will feed, grow, and reproduce. In addition to living in a host, a protist also causes an organism harm. Pathogenic protists vary in the severity of the damage they cause, but they all have a negative impact on their hosts.
The genus Trypanosoma contains a variety of pathogenic protists that can cause various diseases.
In this group, we find a species known as Trypanosoma cruzi. This specific protist is transmitted from wild mammals to humans through skin contact with feces or urine. Once the protist has entered a human, it causes the development of Chagas disease, which can lead to problems with the heart and digestive systems.
Amazingly, wild mammals can carry this protist but are not harmed by it. Trypanosoma cruzi only causes harm when it infects humans and domestic animals.Another species from this group that is classified as a pathogenic protist is Trypanosoma brucei. This protist is transmitted to humans through the bite of an infected tsetse fly.
It causes the human to develop a disease called trypanosomiasis, which is also known as African sleeping sickness. People that are infected by this protist often experience extreme lethargy and fatigue, along with fevers, headaches, and joint pain.
Have you ever heard of malaria? This disease is called by pathogenic protists from the genus Plasmodium, a pathogenic protist carried by mosquitoes. Plasmodium have a very complex life cycle that actually requires both a mosquito and a mammal for proper reproduction.
This protist enters humans through the bite of an infected mosquito, after which it infects the red blood cells and can travel throughout the entire body.The protist is transmitted back to an uninfected mosquito when that individual bites and sucks the blood of the infected person. People that are infected with Plasmodium and develop malaria often suffer from fever, chills, fatigue, nausea, and in severe cases, impaired brain function and seizures.
The last pathogenic protist we will explore is called Toxoplasma gondii. This protist is common in cats and can be transmitted to humans through feces. If a person comes in contact with cat feces and does not wash his or her hands properly, he or she could ingest the protist.
In most healthy humans, the immune system prevents the protist from causing any harm.However, Toxoplasma gondii can be particularly harmful to pregnant women because the protist can cross the placental barrier and cause harm to the developing fetus that does not yet have an immune system. Many doctors suggest that pregnant women avoid cleaning litter boxes during their pregnancy to avoid the risk of contracting this protist.
Throughout this lesson, we explored a variety of different pathogenic protists, which are single-celled organisms that cause diseases in their hosts. The first group of pathogenic protists are species from the genus Trypanosoma. These protists are responsible for causing the development of Chagas disease, as well as African sleeping sickness.
Plasmodium is another type of pathogenic protist that is transmitted by mosquitoes and causes malaria. The last pathogenic protist is called Toxoplasma gondii and is common in cats and can be transmitted to humans through feces. It should be noted that in pregnant women, it can cause harm to a developing fetus. Although these examples of pathogenic protists are transmitted in different ways and cause a variety of diseases, they all have one thing in common: They can get inside the human body and cause harm.