Food manufacturers can't afford to ignore Listeria, a foodborne pathogen that can kill and has killed people.
Food manufacturers can't afford to ignore Listeria, a foodborne pathogen that can kill and has killed people.

For food-safety personnel at meat or poultry plants, detecting Listeria monocytogenes is akin to finding a needle in a haystack.

“You are chasing something you can’t see,” says Melissa Raybon, the plant manager at Fieldale Farms’ poultry-processing plant in Baldwin, Ga. “You are chasing a ghost.”

But plant managers and food-safety experts at meat and poultry plants can’t afford to ignore Listeria, which can kill and has killed people that have eaten food products contaminated with it. The good news about Listeria (if there is any) is that most plant managers and food-safety experts are vigilant about detection and preventing the spread of the pathogen.

“We realize we need to know if it’s there … because we’re ultimately responsible for the outcome,” says Lee Johnson, Ph.D., vice president of technical services for West Liberty, Iowa-based West Liberty Foods, which processes sliced meats. A we-can-find-it attitude has gradually permeated the culture of the meat and poultry industry, Johnson adds.

At Fieldale Farms, Raybon leads a proactive program to find Listeria – taking a minimum of 120 swab samples weekly. “Our philosophy is to do everything we can to find it so we can get it back under control or eradicate it,” she explains.

The last thing Raybon wants to occur is a recall for contaminated product. “Because there’s a whole new set of issues if we find it on product,” she says.

Learning Experiences

Raybon, who has worked in the poultry industry for 17 years, has spent nearly five years at Fieldale. Her first exposure to a Listeria outbreak occurred at a previous job at a poultry plant located in the Southeast that produced fully cooked poultry.

Listeria can be found just about anywhere — even in places where you least expect.
Listeria can be found just about anywhere — even in places where you least expect.

After “tearing apart everything on the production line” to find the source of the outbreak, Raybon and others turned their attention to two exhaust stacks – one for a char-mark and the other for a spiral chiller. The bug was found in the char-mark stack after water had seeped into cracks of the stack’s weld when it was sanitized. The problem was rectified once the cracks were repaired.

What did Raybon learn from the outbreak?

“I think sometimes we have a tendency to focus on hand-washing … don’t get me wrong that is very important … but we focus more on the people side of things than the equipment side of things,” she says.

At the time, Raybon felt the breakout had a lot to do with equipment design. She still does. To that point, she stresses that equipment needs to be broken down properly on a regular basis so the sanitation crew has time to clean it properly. However, she realizes that shutting down production lines isn’t an option. That’s why Raybon implemented zone cleaning on Sundays at the Fieldale plant. Every Sunday or every other Sunday, Raybon and other members of the food-safety team will concentrate on a specific area of the plant to deep clean.

One of those areas is the oven room. “So this Sunday, for example, we will remove all the belts from the ovens and soak them,” Raybon explains. In addition, nuts and bolts will be removed from conveyors and those materials will be hand scrubbed. And then it’s all put together again before undergoing normal sanitation on Sunday night.

Then it’s on to the other zones in the plant the following Sundays. The goal is for every zone to receive a detailed cleaning about every 10 weeks.

Once a month, Raybon and Fieldale’s quality assurance manager and maintenance manager also survey the RTE lines and freezers, looking for anything they think could harbor Listeria. All it takes is for one crack in equipment or the floor to harbor the pathogen, Raybon says, noting that it can spread quickly through the air.

“You have to be diligent to stay ahead of it,” Raybon says.

The spokesman for a Southern-based meat-processing company that experienced a product recall due to a Listeria outbreak a few years ago, says the company tested for the bacteria the way it was supposed to, but still experienced an outbreak.

“We went by the book,” the spokesman adds.

Looking back, the spokesman, who asked that he and his company not be identified, realized that “by the book” may not have been enough.

The plant where the outbreak occurred is now closed, because the company decided to outsource that part of its business. But if it was still open, the spokesman says he would change his attitude about Listeria and go on the offensive, instead of the defensive.

“While we had been testing for it, we really didn’t want to find it,” he says.

He realizes if the Listeria would have been found through additional testing, the plant would have been in control of the situation and there might not have been a product recall. He also says he would expand environmental testing and do more testing in the middle of production, not just before production.

The spokesman also learned that Listeria can be found just about anywhere, even places one would never expect. Ironically, after the recall, the pathogen was found harboring in a tube on a machine that sprayed acidified sodium chloride on product to kill Listeria.

The tube, which he and others thought was solid, turned out to be hollow. It also turned out that meat was slowly creeping into the tube, where the Listeria was harboring and contaminating product.

“I’ve heard people say that the cleaner your plant is, the more likely you have a chance for Listeria because it doesn’t compete well with other bacteria,” the spokesman says. “So if you knock out all the other bacteria, then the smallest bit of Listeria has a chance to flourish if it finds a hiding spot.”

|||Read more: A Diligent Approach|||
A Diligent Approach

 Percent positive tests for Listeria have declined since 1998.
FSIS regulatory testing results for Listeria monocytogenes in ready-to-eat meat and poultry products (Source: North American Meat Institute.

West Liberty Foods’ Johnson says all meat and poultry processing facilities, big and small, are at risk for Listeria. “Where there is protein and moisture, there’s ample opportunity for it to grow.”

But Johnson is impressed with how the industry has reacted to combating Listeria, noting that West Liberty Foods is doing everything it can to control it and other pathogens.

In 2010, West Liberty Foods received a Clean Room Food Processing Systems, Methods and Structures patent for its manufacturing facilities.

A major move in the battle against Listeria contamination is when the industry mandated separation of production of raw and ready-to-eat products in plants, which reduced potential for cross contamination, Johnson says, noting that West Liberty Foods has taken the mandate to another level by implementing individually contained rooms so employees aren’t moving from place to place.

“Ultimately, it’s setting up the facility to make it easier for people to do the things you want them to do and very difficult to do the things you don’t want them to do, like walking into a ready-to-eat area from a raw area,” Johnson explains. “If you limit that ability for people to move around freely, you’re controlling a risk point.”

West Liberty Foods has also invested in new equipment that facilitates more efficient equipment cleaning. Earlier this year, the company installed a high-pressure processing (HPP) technology system in its Bolingbrook, Ill., facility, the fifth unit of its kind in the company’s three plants. High-pressure pasteurization is an all-natural, environmentally friendly technology that uses water under high hydrostatic pressure to prevent the growth of pathogens in packaged foods.

If companies don’t invest upfront, they could end up paying on the back end if Listeria is detected and a recall ensues, Johnson says. Processing equipment that can be easily and efficiently cleaned will help control Listeria, Johnson assures.

A trend in the food industry, including on the meat and poultry side, is the growing consumer demand for clean label products that are minimally processed and free from chemical additives. This has impacted sanitation, Johnson says.

“We have responded,” Johnson says. “Ultimately, to deliver the same level of food safety as an antimicrobial does, you have to have the equipment to do that. High pressure pasteurization is a tool to deliver that for us. A lot of customers like it, and seem to be willing to pay for the added cost [for us] to provide that safety.”

Johnson says discipline and attention to detail are crucial on the processing floor when trying to find Listeria. Discipline is taking regular swabs. Attention to detail is taking swabs in difficult-to-get-to areas. It’s also important to evaluate activities on the plant floor and study data diligently.

“Then, detection is at the front of your mind, not buried in your mind,” he says.