Catch microbes before they become a problem and work to implement a microbial contamination control strategy. The perspective of Anne Wagner, PhD, Technology and Market Development Manager for Charles River's Microbial Solutions division.
Manufacturing is often perceived and evoked from the angle of its efficiency. We've all seen those reports or ads showing conveyor belts with bottles filled and packed in seconds. Speed and efficiency are essential to manufacturing, but everything falls apart if it is not based on the quality of the product.
Let's take the example of manufacturing household cleaning and personal care products. They are not "sterile" companies, but non-sterile does not mean non-quality. One of the biggest antagonists of consumer product safety is microbial contamination. If microbial contamination occurs in your plant, a series of events are triggered to respond, disinfect and remedy the problem, costing time and money. But sometimes contamination goes undetected and reaches the market, causing a recall with a greater and broader impact. From 2014 to 2019, the vast majority of recalls requested by the FDA – 78% – were due to microbial contamination (see ill.). The Safety Gate, the EU's early warning system, has also detected problems with microbial contamination over the years. Not all microorganisms are pathogenic, but products must be free of microorganisms that cause harm.
Notorious culprits behind recent product recalls
Several high-profile incidents of microbial contamination have led to product recalls in recent times. These include Pluralibacter gergoviae and Cronobacter sakazakii. Pluralibacter (Enterobacter) gergoviae is a bacterium commonly found in water. It is classified as an opportunistic pathogen with a low risk to healthy people, but it can cause infection in people with weakened immune systems. P. gergoviae is of particular interest to the consumer products industry because of its acquired ability to evade common cosmetic preservatives. A publication by Dr. Periame in the Journal of Applied Microbiology found that P. gergoviae has evolved so well that it now has multiple mechanisms, including detoxifying enzymes, flagellin expression, and a modified cell membrane structure, to survive in the presence of common cosmetic preservatives. With microorganisms like P. gergoviae becoming more 'smart', we also need to adapt to keep them away from consumer products.
Another notorious microorganism that has made its way into food and consumer products is Cronobacter sakazakii. Like P. gergoviae, it is also an opportunistic pathogen. In fact, these two microorganisms previously belonged to the same genus, Enterobacter, but were later classified into separate genera as the taxonomy improved. Cronobacter sakazakii was discovered from clinical human isolates and was found to be resistant to desiccation. C. sakazakii has been found in home and food environments. Infections have been reported in elderly and immunocompromised people; it is also a high-risk microorganism for infants when it ends up in infant formula and contaminates them. In a recall notice issued by the FDA in March 2022, a major producer of powdered formula discovered the presence of Cronobacter sakazakii in its product and then in its manufacturing plant, resulting in a massive recall and supply chain issue.
Contamination of infant formula with C. sakazakii can put babies at risk of infection, sepsis, meningitis and necrotizing enterocolitis. 7 The proposed sources of C. sakazakii may come from poor manufacturing practices and contaminated raw materials or may come from human sources.
Testing early and again upstream for microbial contamination
Microbial contamination is not necessarily homogeneous in the product and can have variable growth rates, so you should be careful not to miss it. Unfortunately, even with tests on the final product, microbes can go unnoticed. Testing earlier in the manufacturing process and further upstream to ensure raw material quality and water purity, as well as implementing effective cleaning practices and good manufacturing practices can have a significant positive impact on reducing microbial contamination. These practices are all part of good industrial hygiene designed to find the source of a problem before it gets out of control.
To make a simple analogy, it's like going to the dentist every six months for a regular checkup. By looking very early, you can spot a small cavity and plug it before it gets worse. But if you don't spot it and ignore it, this decay can turn into a painful root canal treatment. Preventive measures can prevent small problems from getting worse.
Recall is the worst-case scenario, but microbial contamination can impact every facet of a business. When a product fails microbial release testing, corrective action is costly, revenue is lost, and manufacturing plants can be taken out of service, having a huge impact on the company's supply chain. In the case of a recall, the same monetary losses occur, but the impact is wider, with very public notifications, and depending on the microbes, contamination can cause illness in the consumer and even, in some tragic cases, death. Customers demand quality and it is the manufacturer's responsibility to keep this promise of quality. It is therefore necessary to catch microbes before they become a problem and implement a microbial contamination control strategy, which involves monitoring your environment using modern technology to detect microbial contamination faster and more accurately. By putting all these protective measures in place, you ensure that your product is of better quality and has a safety profile that you can guarantee to your customer.