Answer:
Protists are any eukaryotes that are not animals or plants. examples include amoeba and diatoms among others. Some of them are pathogenic.
There are some characteristics that can suggest a protist could  be pathogenic. Such as;
The mode of acquiring food or nutritional characteristic
Protists that are heterotrophic are more likely to cause disease than autotrophic protists since they cannot make their own food an depends on other organisms.
Method of locomotion
Protists that lack certain important locomotive organelles or that are nonmotile are more likely to be parasitic or pathogenic than those that are.
