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From: Food Quality & Safety magazine, June/July 2012

Food Safety Happens in a Vacuum

by Jared Bradley

Over the past couple of decades, many millions of dollars and countless man-hours have been invested in the ever-growing war against foodborne illness. Learning the intricacies of every pathogen down to the mitochondria and beyond, studying the makeup of a biofilm, inventing a new intervention or vaccine to reduce pathogens on hides, expending extra effort to ensure the blades of a deli slicer are clean after the lunch rush, and millions more individual actions all contribute to the battle against the unseen, persistent enemies of health and food safety.

Knowledge, understanding, hard work, and the tools of the trade are all weapons that, when combined and applied effectively, can result in food safety for billions of people around the world.

Unfortunately, very few people fully understand the herculean effort that goes into ensuring that the world’s food supply is as pathogen-free as possible. Most people assume, as I did before I became more involved with the food industry, that food safety just happens and that any outbreak or recall simply arises from a lack of effort on the part of the manufacturer. Having gained a better understanding of the hard work and massive expense that go into food safety and quality assurance, I can attest that nothing could be farther from the truth.

The M-Vac is a non-destructive, highly sensitive sampling method.
The M-Vac is a non-destructive, highly sensitive sampling method.

How is it, then, that despite the hard work, massive expense, and unprecedented knowledge, technology, and information that freely and rapidly flow around the world, there are still so many foodborne illness incidents and recalls—and what is being done about it? It’s not an unfair question by any means, and it’s one that is asked increasingly amid today’s technological wonders and our ever-increasing expectation of instantaneous solutions.

Unfortunately, we tend to expect, along with lives that often exist somewhere between the microwave and level 24 of the latest zombie videogame, fresh and delicious food that is absolutely unblemished and perfectly safe. Eliminating the causes of foodborne disease surely can’t be more difficult than sweeping a computer virus or online dating?

In order to bravely exit the sterile bubble we’d like to be in when it comes to food, we must acknowledge several critical facts of life:

  • There is no such thing as zero pathogens in food. The reality is that contamination can be introduced at any point, including in your own kitchen;
  • The closer you get to zero pathogens in or on a food or food surface, the more difficult it is to detect those pathogens; and
  • It is in everyone’s best interest, and, frankly, it is the responsibility of every individual from farm to fork, to make the food chain as safe and secure as possible.

Food safety was once again thrust into the national spotlight with the Food Safety Modernization Act. For some, the heightened public attention on food safety is a major victory, while for others it’s a nuisance—or a nightmare.

For a real-life opinion of what that spotlight feels like, I imagine the previous owners of the Peanut Corporation of America could give us an interesting perspective. Regardless of anyone’s opinion about whether or not the spotlight is a good thing, I believe it’s here to stay, as do pretty much all of the folks that I have talked to.

Origin of a Solution

Although there were major outbreaks prior to 1993, one of the first major foodborne illness outbreaks that gained international notoriety was the 1993 E. coli outbreak involving undercooked hamburgers. It created a new form of litigation and a new sense of business exposure for the food industry.

During that outbreak, Bruce Bradley, PhD, became particularly bothered by the suffering and damage E. coli was causing, especially for children, and decided to contribute to the solution.

The M-Vac is a non-destructive, highly sensitive sampling method.
With the enclosed sampling head the M-Vac can take samples before, during, and after production.

While dissecting and evaluating the product safety and process control measures in question, he realized that one of the weakest links in the chain was surface sampling and the pathogen-extraction process from the food product itself, along with surfaces the food may touch during the manufacturing process. Dr. Bradley then narrowed his focus to the area of surface sampling—and the Microbial-Vac System was born.

The Microbial-Vac System, or M-Vac, is a wet vacuum surface sampling system that shares several characteristics with a carpet cleaner. Imagine the hand-held attachment used to clean a piece of furniture: Omit the rotating brushes and add in the fact that the M-Vac is sterile and smaller, and the idea is the same.

The M-Vac is a non-destructive, highly sensitive sampling method.
The sampling hose enables the user to reach difficult areas with the sampling head.

Just as a carpet cleaner sprays down a solution to get the deep dirt out of the fibers, cracks, and crevices of a carpet or couch, the M-Vac System sprays down a solution and at the same time vacuums the pathogens out of a food surface. Especially compared with the sponge and swab sampling methods, the M-Vac System is significantly more effective.

The M-Vac has shown consistently greater recoveries than most other sampling methods and, due to its scalability in covering larger surface areas, is essentially unlimited in its sensitivity (see Table 1). These capabilities and more are exactly what one would expect when closely evaluating the wet vacuum concept.

The secret to the M-Vac System’s effectiveness is that the pressurized, sterile liquid is applied at the same time as the vacuum. That combination creates what Dr. Bradley called the LAMDAC principle: liquid-assisted microbial detachment and capture. It’s what enables the M-Vac to effectively extract pathogens, viruses, drug residue, and virtually any other type of microscopic particle from a surface, including those that are embedded and/or attached.

Recovery of Common Food Pathogen Simulants from Representative Food Processing Environmental Surfaces
click for large version
Table 1. Recovery of Common Food Pathogen Simulants from Representative Food Processing Environmental Surfaces

The M-Vac is a much more aggressive form of sampling, bringing to bear multiple elements to extract every possible particle from a surface. This is critical when dealing with bacteria such as E. coli, Listeria, Salmonella, or the many other foodborne illness-causing adulterants. Even one cell that is missed can quickly multiply into billions and wreak terrible havoc on the populace. The most dangerous scenario is when the QA sampling is done at the right place and at the right time, and the sampling method fails to extract the contamination, giving the producer a false negative reading and a false sense of security.

Meaty Motive

The M-Vac System was originally designed for the meat industry, to sample carcasses shortly after slaughter. Dr. Bradley knew that the vast majority of pathogens enter a meat-processing facility on the hide, getting onto the meat during the removal of the hide, and that it would be best to detect those pathogens as early as possible after the hide is removed.

Dr. Bradley believed sampling product post-production is almost worthless, because by that point it is too late in the process to really do anything about the contamination other than destroy or cook the contaminated product, which is, at best, a small percentage of the overall product volume. Most importantly, it tells the plant little about the upstream process and nothing about where the contamination came from. The higher up the chain the sampling is focused, the more it can be used as a process control tool, giving the plant actionable information.

To date, there is no sampling method that is more effective than the M-Vac System at sampling at line speeds, while at the same time recovering the quantities of pathogens that the M-Vac is capable of. When compared with sponge sampling, the M-Vac has extracted up to six times more bacteria from the carcass surface and is as much as 3 log better when sampling beef hides.

The same need for better sampling and process control tools exists in other industries in virtually the same way. Fresh produce, consumer products, ready-to-eat meats, and processed foods are all areas that will benefit from better surface sampling. Even areas such as DNA forensics, drug residue analysis, anti-biowarfare, and homeland defense are in need of more effective sampling. The exact same sampling principles exist across the board and, when new methods are developed that benefit one area, the others can also benefit.

“If you can see the contamination, you don’t need the M-Vac,” was a favorite saying of Dr. Bradley’s. That holds true for every industry and microbiological circumstance, but it is especially relevant to the food industry. The contamination issues within a food processing facility that can be observed by the naked eye are not usually the ones making consumers sick. It’s the unseen killers that slip through the QA process and sampling and continue on through the food chain, eventually causing foodborne illnesses and product recalls.

The contamination issues that can be observed by the naked eye are not usually the ones making consumers sick. It’s the unseen killers that slip through the QA process and sampling.

Unfortunately, these killers are evolving at the same time the food supply is expanding and becoming more complex. Everyone knows more must be done. The question is: What? Increasing end product testing will, at some point and volume, become counterproductive, because the cost-to-benefit ratio diminishes. We contend that the best way to truly improve food safety is to improve the process control testing, which requires more effective sampling and testing methods during the food production process. That process control testing must start with the M-Vac System.

Over the years, I have met hundreds of food safety and quality assurance professionals from all over the world—and every one of them would cringe at the thought of ever putting contaminated product into the food chain. I am sure that all QA folks, along with most plant managers, lose a lot of sleep worrying about the safety of their product. Based on those I have met, I can assure you that all the people who work in the food industry, from the guy or gal on the processing line all the way to the top executives, the regulatory folks, and every other person involved with the food chain, are good people who have the same goal—good, safe food at a good price. With the introduction of the M-Vac System, those professionals now have another weapon that will improve their ability to wage war against foodborne pathogens and illnesses.


Jared Bradley is president of Microbial-Vac Systems. He can be reached at



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