Module 5: Acellular Pathogens

The acellular microorganisms are considered non-living infectious agents due to the lack of fundamental structures of cellular life, including a nucleus, cytoplasm, and cell membrane, and do not carry out metabolic processes independently and rely entirely on a host cell’s organelles and biochemical machinery for replication and survival.

This chapter will examine three primary types of acellular infectious agents: viruses, viroids, and prions.

• Viruses are composed of either DNA or RNA (never both), enclosed in a protein capsid, and in some cases, a lipid envelope. They invade host cells and hijack the cellular machinery to replicate, often causing cellular damage or death.
• Viroids are small, circular RNA molecules that lack a protein coat. They infect plants and disrupt regular gene expression, leading to disease.
• Prions are misfolded proteins capable of inducing abnormal folding in normal cellular proteins, particularly in neural tissue. They contain no genetic material and are associated with fatal neurodegenerative diseases, such as Creutzfeldt-Jakob disease.

Viruses may cause widespread outbreaks and significantly impact human life across all biological domains due to their rapid mutation rates.

Understanding the mechanisms of infection and transmission of acellular microorganisms is essential for infection control, vaccine development, and patient care.

Studying acellular microorganisms is essential because of their role in infectious disease and their utility in medical research, diagnostics, and biotechnology.

Image / Source: https://upload.wikimedia.org/wikipedia/commons/8/84/Figure_21_01_03.png ;

Upon completion of this module, you will be able to:

1. Read the Module 5 Introduction 
2. Read Chapter 5 in Acellular Pathogens in Medical Microbiology for Nursing and Allied Health: A Louisiana Perspective
3. Complete the module 5 assignment and discussion.

Module Pressbooks Resources and Activities

You will find the following resources and activities in this module at the Pressbooks website. Click on the links below to access or complete each item.