Infectious agents and disease - An overview

Infectious agents

Agents that can enter the body and cause injury, disease, or death.

Pathogenic

Refers to an infectious agent that causes disease.

Virulence

The degree of pathogenicity or severity of an infectious agent.

Prion

An infectious agent consisting of misfolded proteins that can cause disease.

Virus

An infectious agent that is not alive and requires a host cell to replicate.

Bacteria

Single-celled organisms that can be classified based on their shape and cell wall properties.

Fungi

Eukaryotic organisms that have cell walls made of chitin and often reproduce via spores.

Protozoa

Unicellular eukaryotic organisms that often cause disease.

Helminths

Parasitic worms, which can be large and categorized as roundworms, flatworms, or flukes.

Peptidoglycan

A polymer that makes up the cell wall of bacteria.

Gram-positive

Bacteria with a thick cell wall that retains the crystal violet stain used in the Gram staining protocol.

Gram-negative

Bacteria with a thin cell wall and an outer membrane that does not retain the crystal violet stain.

TSE (Transmissible Spongiform Encephalopathies)

A group of infectious diseases caused by prions that lead to brain dysfunction.

Mycosis

Fungal infection, which can affect the skin or internal organs.

Diarrhea-related diseases

Diseases often caused by infectious agents that lead to excessive loss of fluid in feces.

HIV/AIDS

A viral infection that attacks the immune system and can lead to AIDS.

Chlamydia

An obligate intracellular bacterium that can cause reproductive issues and eye infections.

Malaria

A disease caused by protozoa transmitted by mosquito bites.

CVD

Cardiovascular disease, listed as a leading cause of death.

Vaccination

The administration of a vaccine to stimulate an immune response.