Plant shutdown, a shortage of key products, patients unable to access important drugs, profits hit … the consequences of a biological contamination can be devastating for a biopharmaceutical manufacturer.
Detection of a viral contamination at a manufacturing facility can halt production of drugs with significant sales loss, potential lawsuits and even decline in stock value as a result.
Preventing contamination, however, poses a serious challenge for biopharmaceutical manufacturers.
The challenges of Mycoplasma contamination
- Mycoplasma are slow growing and may be difficult – or impossible – to culture and detect using standard microbiological techniques.
- Mycoplasma can infect mammalian cell cultures through adhesion and subsequent fusion to cell membranes, allowing them to exploit the conditions and synthesized molecules provided by the host cell. This means that detection and quarantine procedures must also be implemented around cell lines.
- Mycoplasma can vary in size and shape from 0.2 microns upwards, have no peptidoglycan cell wall and exhibit pleomorphism (the ability to alter size and shape in relation to environmental conditions). This means that they are capable of penetrating sterilizing grade filtration membranes.
Audience polls conducted during our webinar entitled Implementing a Risk-Management Based Approach to the Prevention of Mycoplasma Contaminations, suggested that approximately 45% of respondents were using 0.2 micron filtration to sterilize growth media. Additionally, as part of the same poll, the majority of respondents who used Mycoplasma retentive filtration indicated that they were reliant on the filter manufacturer’s Mycoplasma retention claim, generated under test conditions, using the organism Acholeplasma laidlawii.
This suggests that a high proportion of respondents are completely confident that their process is Mycoplasma free, or alternatively, do have a concern but have not conducted process specific filter validation.
Gamma irradiation or heat inactivation to eliminate mycoplasma present on gamma or heat stable incoming raw materials can be used to guard against contamination. In order to understand the true risk to a manufacturing process – and avoid the potential for increased contamination from raw materials – suitably validated detection techniques should be implemented.
In addition to detecting Mycoplasma and ideally avoiding the potential for contaminant organisms from entering a facility in the first instance, employing filtration steps to safeguard against Mycoplasma entering the biopharmaceutical process also has a vital role to play in combating contamination.
Filtration and automation
The use of a Mycoplasma retentive 0.1 micron filter, such as Parker’s PROPOR MR, to sterilize growth media, is recommended for mammalian cell cultures due to Mycoplasma’s ability to penetrate larger filters.
However, filtration process conditions can affect mycoplasma retention. A study was carried out by Parker to determine whether there is a link between filter pressure and retention levels using the organism Mycoplasma faucium. Challenges were conducted at different pressures with conditions continuously monitored using a SciPres® single-use pressure sensor. The results showed a clear relationship between filtration pressure and filter performance, as retention rates dropped dramatically once a threshold pressure was exceeded.
We speculate that, at this identified threshold pressure, the mechanical strength of cells present on the membrane is overcome, causing them to be deformed and forcing them through the filter pores – leading to contamination.
By automating a process, pressure levels can be constantly monitored and, if sporadic pressure peaks occur, they can be identified and controlled.
A system such as Parker’s SciFlex® NFF platform with single-use flow-path can be used to control differential pressure and maintain this below proposed threshold values at which Mycoplasma is not significantly diminished. The result is documented evidence that validated pressure limits have not been exceeded - and the peace of mind provided by a safe processing method.