Updated: Jul 5

Editorial | Open Access | Published 25th March 2022


GUEST EDITORIAL : Contamination Control Strategy in the QC Microbiology Laboratory


Authors : Tammy Hassel & Lina Celis Bautista - A2Z Microbiology




In recent years the pharmaceutical sector has been abuzz with words associated with data integrity, but with an updated Annex 1 on the very near horizon, a new term, Contamination Control Strategy (CCS), is about to become the common language to those operating in this space.


Immediately thoughts jump to how to gather all the relevant references together into a cohesive document that is of use to a site, manageable from an update perspective and seen as value-adding by all those who need to access it on a day to day basis, but what of CCS in the QC Micro Lab? While we try not to point fingers when things go wrong, the finger is initially directed back at the lab when a microbiology result comes back out of limits or out of specification. What follows is an investigation that is often shoehorned into a generic lab phase 1 template which does not always provide a satisfactory root cause. Nothing can destroy trust and credibility faster than lab-based errors that remain a persistent problem.


But, what if the CCS approach is also applied to the laboratory? Instead of a generic investigation, the CCS can be referenced to direct the investigation. This approach offers a holistic and objective perspective for the analysing of data and of the process employed to identify the root cause. A CCS designed for your QC Microbiology Laboratory, by your QC Microbiologists, will help the team assess where their risks lie and design mitigation strategies to control for these.


Taking the above into consideration, the CCS will be a live visual and theoretical aide describing the process controls applied from access control and sample management through to the handling, storage, cleaning, comportment, waste removal, and exiting procedures. The CCS pulls together the scattered controls and documentation that exist throughout the lab into one coherent space, easily accessible to all users of the lab.


At a high level, a CCS should consider all aspects of the running of a lab, starting with training and culture before working its way through to access control and goods receipts and onwards to exiting procedures and waste removal. In the next few paragraphs, we discuss a few of the higher-level elements for consideration for inclusion on your CCS.


TRAINING AND CULTURE: Your CCS should include your training approach. The criticality of contamination control should be learned and embedded into your team and its culture from the very start. Training provides the opportunity for you to explain and justify the controls in place, which in turn helps your microbiologists understand the importance of implementing the good practices you and your team have developed, building on a culture centred around contamination control.


ENTRY AND GOODS IN PROCEDURE: Training provides the backbone of a CCS after which the more practical elements can be introduced. Entry of people and samples into the lab are the initial touchpoints the manufacturing process has with the lab. How your microbiologists gown up will ensure both operator protection, protect against inadvertent transfer between testing spaces and also protect against your team carrying contamination out of the lab and into the manufacturing environment when they leave again. The same applies to samples coming into the lab, have they known contaminants or are they “clean” samples and if so how does your team handle these samples and store them. Segregation and comportment in handling are critical to protecting against cross-contamination.


TESTING AND LAB DESIGN/LAYOUT: The CCS should consider the testing of samples and as well as the timing of the testing, the location of the activity and the cleaning/sanitisation required to maintain contamination control. Not only is sample handling critical, but also the lab design and the management of materials flowing in and out of your testing zone. All it takes is one non-sterile item, like a non-irradiated marker pen for plate labelling, to make its way into the BSC to contaminate your working environment. Post testing, the CCS should consider how the segregation of your “dirty” and “clean” plates is to be managed followed by the clean down of the test environment.


MONITORING PROGRAM: The CCS should consider the efficacy of your cleaning. An ideal arrangement would include a monitoring program to help direct any investigations. The information gathered from monitoring the lab can be invaluable in identifying problem spots or sources of contamination.


PROCESS FLOW: Transfer and segregation of work is another critical feature of the CCS. Work where contamination sources are exposed, for example, positive control testing, identification work, reading of environmental monitoring samples etc should be performed away from areas where aseptic techniques and sterile/”clean” samples are being handled and again, the transfer of these samples and test plates should not pass close to, where possible, areas where more “dirty” work is being performed.


EXIT AND WASTE REMOVAL: The CCS must include the egress process for waste, equipment, materials and staff. If any contamination were to make its way back to the plant, you instantly create more work for your lab and potentially put patients at risk. This means the process of de-gowning, waste removal and equipment movement out of the lab is a critical part of the CCS.


While providing a high-level run-through of some of the more critical considerations of a CCS for a lab, the purpose of this editorial was to introduce the concept that CCS should not be purely focused on the manufacturing plant but should also be applied to the lab, where critical testing and thus trustworthy results are being generated. A CCS provides the framework of lab operations to ensure the results being produced are a true reflection of the samples being tested. We encourage you to consider implementing this idea for your own laboratories.