Bioburden testing is considered as one of the most crucial processes in industries such as the medical devices, biotechnology, pharmaceuticals and food manufacturing done to guarantee the safety of products along with regulatory compliance.
The term ‘bioburden’ defines the amount of viable microorganism that may be present on a specific surface, product or raw material before the process of sterilisation is initiated.
An accurate bioburden analysis is significant to rule out the microbial contamination to validate sterilisation processes and ultimately come up to the required regulatory standards.
Companies now require an innovative and advanced bioburden testing strategy owing to the increase in consumer awareness along with the strict international laws.
Application of Bioburden Testing Across Different Industries
1- Medical Devices
Medical devices refer to catheters, surgical instruments, implants and more. All these items related to the medical field should be free from contaminants in order to avoid the potential chances of infections.
Bioburden testing helps evaluate the levels of contamination before the process of sterilisation. This ultimately ensures proper compliance with ISO 11737 standards.
2- Pharmaceutical Industry
Potential contamination on drugs, vaccines and other pharmaceutical products can cause a spike in the risks of infections. Bioburden testing helps rule out these hazards ensuring that pharmaceutical products are free from contamination. This is one important part of the Good Manufacturing Practices or GMP.
3- Biotechnology
The processes used in the field of biotechnology often use live cultures along with sensitive materials.
Testing for bioburden analysis is one step taken to ensure that microbial contamination doesn’t pose a risk to the integrity of research or production outcomes.
4- Food and Beverage Industry
Salmonella is one microorganism that can infect urine, blood, bones or joints. Bioburden testing remains the core of safety done to make sure that organisms like E. coli and molds do not infect the consumable products. As a result, consumer health is protected.
Bioburden Testing Methods
There is a lengthy list of the approaches used to determine the bioburden levels. Each of these (mentioned below) are done based on manufacturing environmental and regulator requirements.
1- Plate Count Method
The method literally involves nutrient rich agar plates on which microorganisms are cultured.
The colonies are then measured after the incubatory period.
It is among the most simple yet cost-effective techniques. One advantage is that one can get results in quantitative form. However, this method comes with its own set of disadvantages such as the increased time that it requires (typically 24-48 hours) for result. In addition to this it is also specific to the cultivable organisms.
2- Direct Inoculation
Direct inoculation is a technique in which samples are inoculated in a growth medium. This is then incubated for microbial growth.
This method is mainly used for products that cannot be otherwise filtered. It is an uncomplicated technique. But one of the drawbacks is that it may only be useful for massive sample volumes.
3- Membrane Filtration
In this process, a liquid sample is passed from a semi-permeable membrane. This filter is able to trap microorganisms which are further cultured on a nutrient rich medium.
This process is super useful due to its high sensitivity. Moreover, it is also an ideal technique for samples with low-burden levels.
4- Rapid Microbial Methods (RMMS)
This involves utilisation of advanced and innovative techniques such as ATP bioluminescence, PCR, along with flow cytometry. All these procedures have the ability to detect microorganisms much quicker (faster turnaround ranging from minutes to hours) when brought in comparison to the traditional methods.
5- Surface Monitoring Techniques
Surface monitoring is among the most important strategies used for bioburden control. It is of specific significance in cleanroom environments where the chances of contamination should be limited.
The aim of this is to measure microbial contamination on the diverse production surfaces such as tools, gloves and more.
Some of the common surface monitoring techniques have been listed below:
- Swab Testing
in this process, sterile swabs are basically moistened using saline or buffer. This swab is then rubbed over a surface and then combined with a culture medium for the purpose of incubation.
It is a helpful procedure for irregular surfaces. Moreover, the process is highly flexible.
- ATP Bioluminescence
ATP or adenosine triphosphate levels are computed through the use of a bioluminescence reader. The presence of ATP is a strong indication of microbial contamination.
This process has lengthy benefits but the most potent is that it provides a very rapid yet reliable result.
- Tape Lift Testing
In this process, simply an adhesive tape is pressed onto a surface which is then transferred to a microbial slide.
This is a relatively, easy and non-complex technique. Moreover, it is also non-destructive. However, one of the limitations is that when brought in comparison to the other methods, it is less quantitative.
