Understanding Microorganisms and Their Role in Infections

Types of Microorganisms

Microorganisms play a crucial role in infections. Understanding their types can help us implement effective infection control practices to protect against various infections. Below, we explore the different types of microorganisms:

Bacteria

Bacteria are microscopic organisms, typically ranging from one-thousandth to five-thousandth of a millimetre in diameter. They are single-celled and one of the earliest forms of life on Earth. Bacteria are so small they can only be seen under a microscope. They are abundant, with estimates suggesting there are ten times as many bacterial cells as human cells in the body. While some bacteria cause diseases, others assist in essential processes such as digestion and food production (e.g., cheese and yoghurt). Bacteria's susceptibility to antibiotics varies.

Viruses

Viruses are significantly smaller than bacteria and can only replicate inside living cells. They are not affected by antibiotics, though some antiviral medications can treat specific viral infections. Viruses are responsible for many common and rare diseases, such as the common cold (caused by rhinoviruses) and AIDS (caused by HIV). Viruses may contain either DNA or RNA as their genetic material.

Pathogenic Fungi

Pathogenic Fungi include both moulds and yeasts. Moulds can cause infections like ringworm, which can affect both the skin and nails. Common yeast infections include thrush. Fungi can cause a range of infections and are particularly concerning in immunocompromised individuals.

Protozoa

Protozoa are larger than bacteria and are microscopic organisms. They can cause infections through the ingestion of cysts, sexual transmission, or insect vectors. A notable protozoan infection is Malaria, which is transmitted by mosquitoes.

Worms

Worms, although not always microscopic, can still cause infections. Some pathogenic worms can be transmitted from person to person. Examples include threadworm and tapeworm, which can infest the digestive system.

Prions

Prions are infectious protein particles. A well-known example is the prion responsible for (New) Variant Creutzfeldt-Jakob Disease (vCJD). Prions cause diseases by inducing abnormal folding of proteins in the brain.

Understanding these microorganisms and their roles is essential in implementing effective infection control practices to safeguard health and prevent the spread of infections.