The key difference between bioburden and microbial limit test is that the bioburden test is a test used to determine the total number of viable microorganisms in a product, while the microbial limit test is a test used to determine the maximum number of microorganisms present in a product without affecting its safety or efficacy.
Bioburden and microbial limit tests are two microbiological tests to determine the level of microorganisms in a product for quality assurance. Both these tests are involved in pharmaceutical microbiology. However, these tests are different in nature.
CONTENTS
1. Overview and Key Difference
2. What is a Bioburden Test
3. What is a Microbial Limit Test
4. Similarities – Bioburden and Microbial Limit Test
5. Bioburden vs. Microbial Limit Test in Tabular Form
6. FAQ – Bioburden and Microbial Limit Test
7. Summary – Bioburden vs. Microbial Limit Test
What is a Bioburden Test?
A bioburden test is used to measure the total number of viable microorganisms on a medical device prior to its final sterilization. It is done before the implantation or usage. This test can also give insight into the comparative resistance of bioburden (the number of bacteria living on a surface that has not been sterilized) found on the material. Bioburden test normally measures the levels of microbial contamination in water, raw materials, and finished products. Moreover, the total aerobic microbial count (TAMC), and total combination yeast and mold count (TYMC) are part of a bioburden test.
This test is primarily performed by cutting up, disassembling, or flushing the fluid path of the test unit using sterile tools in order to prepare the sample. Furthermore, this test can be used for the detection of total viable microorganisms in medical devices, pharmaceuticals, food and beverages, water, packaging, raw materials, human tissue, animal tissue, and cosmetics.
What is a Microbial Limit Test?
The microbial limit test is also known as the “test for specified microorganisms.” This test is used to estimate the number and type of aerobic microorganisms that are present in pharmaceutical ingredients, intermediates, and final products, that have a natural or biological origin without affecting their safety or efficacy.
Moreover, membrane filtration, direct plating, spread plate, and serial dilution are normally part of microbial limit tests. In addition, a microbial limit test is used on non-sterile pharmaceutical, healthcare, or cosmetics manufacturing samples that range from raw materials to finished products.
What are the Similarities Between Bioburden and Microbial Limit Tests?
- Bioburden and microbial limit tests are two microbiological tests to determine the level of microorganisms in a product for quality assurance.
- Both these tests are involved in the pharmaceutical microbiology.
- These tests can be done collectively.
- Qualified microbiologists should perform them.
What is the Difference Between Bioburden and Microbial Limit Test?
A bioburden test is a test used to determine the total number of viable microorganisms in a product while a microbial limit test is a test used to determine the maximum number of microorganisms present in a product without affecting its safety or efficacy. Thus, this is the key difference between bioburden and microbial limit test. Furthermore, the bioburden test is used to check medical devices, pharmaceuticals, food and beverages, water, packaging, raw materials, human tissue, animal tissue, and cosmetics. On the other hand, the microbial limit test is used to check on non-sterile pharmaceutical, healthcare, or cosmetics manufacturing samples that range from raw materials to finished products.
The infographic below presents the differences between bioburden and microbial limit test in tabular form for side-by-side comparison.
FAQ: Bioburden and Microbial Limit Test
What is bioburden?
Bioburden indicates the presence of viable microorganisms on a surface (or complete item), inside a device, or in a portion of liquid, before sterilization. It measures the microbial contamination levels on or in a product.
Why test for bioburden?
Since it determines the microbiological quality or cleanliness of a test unit, this test is required.
What is another word for bioburden?
Microbial load and bioload are synonyms of bioburden.
Summary – Bioburden vs. Microbial Limit Test
Bioburden and microbial limit tests are two microbiological tests to determine the level of microorganisms in a product for quality assurance. Both these tests can be performed in combination. However, the bioburden test determines the total number of viable microorganisms present on a surface before sanitization while the microbial limit test determines the quality and quantity of viable aerobic microorganisms on non-sterilized pharmaceutical or other samples. Moreover, the bioburden test comprises methods such as total aerobic microbial count (TAMC), and the total combination yeast and mold count (TYMC), whereas the microbial limit test comprises methods such as membrane filtration, direct plating, spread plate, and serial dilution. This summarizes the difference between bioburden and microbial limit test.
Reference:
1. “Bioburden Testing vs. Microbiology Testing.” Ethide Laboratories.
2. “Microbial Limit Test.” Industrial Microbiology | Merck.
Image Courtesy:
1. “Bacteria (259 05)” By Doc. RNDr. Josef Reischig, CSc. – Author's archive (CC BY-SA 3.0) via Commons Wikimedia
2. “MALDI-TOF process” Solntceva V, Kostrzewa M, Larrouy-Maumus G (2020). “Detection of Species-Specific Lipids by Routine MALDI TOF Mass Spectrometry to Unlock the Challenges of Microbial Identification and Antimicrobial Susceptibility Testing.“. Front Cell Infect Microbiol 10: 621452. DOI:10.3389/fcimb.2020.621452. PMID 33634037. PMC: 7902069. (CC BY 4.0) Wikipedia Commons
