What is the Difference Between Bioburden and Endotoxin

The key difference between bioburden and endotoxin is that bioburden is the number of microorganisms found in a given amount of material before undergoing sterilization, while endotoxin is a type of toxin released by microorganisms to the surrounding environment.

Microbial testing or analysis often covers the use of biological, biochemical, or chemical methods to detect and enumerate microorganisms. It is usually used for the detection of disease-causing and spoilage microorganisms. Microbial testing is very important for many industries, individuals, and caregivers worldwide. Microbial testing is essential to identify threats such as E.coli, Staphylococcus, Pseudomonas, Candida, Aspergillus, etc. It also helps to maintain high quality in industries. Bioburden and endotoxin are two important factors in microbial testing in order to detect the level of microbial contamination and to decrease the risk of infection.

CONTENTS

1. Overview and Key Difference
2. What is Bioburden
3. What is Endotoxin
4. Similarities – Bioburden and Endotoxin
5. Bioburden vs Endotoxin in Tabular Form
6. Summary – Bioburden vs Endotoxin

What is Bioburden?

Bioburden is the concentration or quantity of microorganisms found from a given amount of material before conducting a sterilization procedure. This term is often used when performing bioburden testing (microbial limit testing). Bioburden testing is usually performed on pharmaceutical products and medical products for the purpose of quality control. The aim of bioburden testing is to measure the total number of viable microorganisms on a pharmaceutical product or a medical device prior to its final sterilization before use.

Bioburden testing for medical devices made is governed by ISO11737 worldwide. Furthermore, the United States Pharmacopeia (USP) outlines several tests that can be performed to determine bioburden quantitatively on non-sterile drug products. When conducting these tests, it is highly important that they do not either introduce microbes into the test sample or kill microbes in the test sample. Popular bioburden testing methods for samples of drugs include the membrane filtration method and plate count method. Bioburden quantification is normally expressed in the colony-forming unit (CFU). Moreover, bioburden is also associated with biofouling. In the healthcare system, this increases the risk of healthcare-associated infections. Natural convection or liquid cooling in critical care units, clean rooms, and HEPA filters are really helpful in hospital settings to reduce the bioburden.

What is Endotoxin?

Endotoxin is a type of toxin released by microorganisms to the surrounding environment. Endotoxins can be deadly to humans.  It usually comes from the cell wall components of gram-negative bacteria. Endotoxins contain both fat components as well as complex sugar components. Therefore, endotoxin is also known as lipopolysaccharide in the scientific literature.

Endotoxins are pyrogens. Pyrogens are fever-inducing substances from microorganisms. When present in sufficient quantity, it can lead to severe signs of inflammation, shock, multiorgan failure and even deaths in humans. Bacterial endotoxin testing can measure the presence and quantity of endotoxins in a specific sample.

What are the Similarities Between Bioburden and Endotoxin?

• Bioburden and endotoxin are two important factors in microbial testing.
• These may contain antigens such as O antigens.
• Both help to detect the level of microbial contamination and to decrease the risk of infection.
• They can be toxic and trigger inflammatory reactions in humans.

What is the Difference Between Bioburden and Endotoxin?

Bioburden is the number of microorganisms found in a given amount of material before undergoing sterilization, while endotoxin is a type of toxin released by microorganisms to the surrounding environment. Thus, this is the key difference between bioburden and endotoxin. Bioburden is measured through bioburden testing, while endotoxin is measured through endotoxin testing.

The following infographic lists the differences between bioburden and endotoxin in tabular form for side by side comparison.

Summary – Bioburden vs Endotoxin

Bioburden and endotoxin are two important factors in microbial testing in order to detect the level of microbial contamination. They help to decrease the risk of infection. Bioburden is the number of microorganisms found in a given amount of material before undergoing sterilization procedure, while endotoxin is a type of toxin released by microorganisms to the surrounding environment. So, this is the key difference between bioburden and endotoxin.

Reference:

1. “Bioburden.” An Overview | ScienceDirect Topics.
2. “Endotoxin.” An Overview | ScienceDirect Topics.

Image Courtesy:

1. “Great-plate-count-anomaly” By Estevezj – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “LPS” By Mike Jones – Own work (CC BY-SA 3.0) via Commons Wikimedia