Bioburden testing is the method of quantifying the number of viable microorganisms in a sample. It is among the most significant processes for ensuring the safety and efficacy of medical devices, pharmaceutical items and other health-care related items.
The ISO 11737-2 standard has stated the required guidelines for the purpose of bioburden enumeration. This would ultimately ensure that laboratories can reliably assess the microbial contamination.
Understanding Bioburden
The term ‘bioburden’ actually refers to the number of microorganisms that are present with in a sample before the process of sterilization. An accurate measurement of bioburden results in enhanced product quality, shelf life and even compliance with the regulatory standards.
The significance of bioburden testing is immense for various applications such as:
- Medical device production: Measuring contamination levels of implants and surgical instruments.
- Pharmaceutical manufacturing: This ensures the sterility of all injectable drugs.
- Environmental monitoring: There is a risk of microbial contamination with in the manufacturing environment. Measuring contamination gives an idea of the level of contamination with in the environment.
An Overview of ISO 11737-2
The ISO 11737-2 is a sub-category of the 11737 series. It specifically focuses on the enumeration of viable microorganisms present with in the medical devices and other such items.
The guidelines are basically a standard for bioburden testing. It provides a framework so that laboratories can carry out accurate and repeated assessments.
Some of the key features of ISO 11737-2 have been listed below:
– Scope: The standard determines bioburden for numerous products including the ones that are intended for the purpose of implantation.
– Principles: It provides guidance on the crucial principles of culture media selection, sampling and also incubation conditions.
Key Methodologies in ISO 11737-2
ISO 11737-2 focuses in two key methodologies for the purpose of bioburden enumeration:
1- Membrane Filtration Method: This method is specifically useful for samples that have a known lesser bioburden level. It literally does what the name says – filters a liquid sample through a membrane that has the capability to retain microorganisms. These organisms are then transferred to a culture media for enumeration purpose.
2- Direct Count Method: This involves placing a volume of sample on a culture media and further incubating it to allow for microbial growth.
This results in the development of colonies that are then counted so as to determine the bioburden.
Both techniques come with their own set of advantages depending on the type of product along with the expected bioburden levels.
Accurate Bioburden Enumeration – Best Methods
- Preparation of sample
A proper sample preparation is mandatory for accurate results. Some of the important aspects of sample preparation include:
- Sample size: An adequate sample size provides a representative measurement of bioburden. According to a recommendation by ISO 11737-2, a minimum volume is advised.
- Handling procedures: Samples should be handled aseptically as an attempt to avoid contamination. Utilization of sterile techniques is mandatory.
- Culture Media Selection
The selection of appropriate culture media impacts the recovery of microorganisms. Some of the ideal methods include:
- Use the appropriate media: Opt for media that would ultimately support the growth of microorganisms. Enriched media might be requirement for specific samples.
- Sterilization: You need to make sure that all equipment used along with media is thoroughly sterilized. This is done so additional contamination can be avoided.
- Incubation Conditions
Incubatory conditions must be optimized to get the right results:
- Atmosphere
Certain microorganisms require variable atmospheric conditions such as anaerobic or microaerophilic for the purpose of growth.
- Time and Temperature
Adhering to the ISO recommendations for temperature and time of incubation.
- Counting Methods
Accurate measurement of colonies is mandatory for the right results:
- Manual vs. Automated counting: Although manual counting is subjective, automated counting can increase accuracy along with reproducibility.
- Validating methods: Validate counting techniques for consistency along with reliability.
- Documentation and Quality Control
- Quality control: A regular quality control analysis can serve very helpful including the use of control organisms.
The Role of CMDC Labs in Bioburden Enumeration
CMDC labs offer a multitude of expertise, knowledge along with resources to guarantee accurate testing as well as compliance with ISO 11737-2.
- Expertise and Technical Support
CMDC labs boast a team of skilled microbiologists and technicians. This helps client adhere to ISO standards and surpass complicated regulatory requirements.
- Advanced Technology
CMDC labs have access to cutting-edge technology that may not be feasible for individual companies to uphold. This includes sophisticated counting systems, advanced automated sample processing and environmental monitoring systems.
- Flexibility
CMDC labs tend to offer flexibility in testing. They provide the clients with an opportunity to scale up and down according to the project requirements. Moreover, this is also valuable for companies that tend to experience deviations in the volume of production.
- Detailed Testing Services
Other than bioburden enumeration, CMDC labs provide a wide variety of testing services. This includes the sterility testing and endotoxin testing as well.
