Disease-Producing Microorganisms Disease-producing microorganisms, or pathogens, are microbes capable of causing infections in humans, animals, or plants. These pathogens include bacteria, viruses, fungi, protozoa, helminths, and prions. Understanding their characteristics and mechanisms is essential for diagnosis, prevention, and treatment of infectious diseases. Categories of Disease-Producing Microorganisms 1. Bacteria 2. Viruses 3. Fungi 4. Protozoa 5. Helminths 6. Prions Mechanisms of Disease Production 1. Invasion: 2. Toxin Production: 3. Immune Evasion: