990338 On the Front Line Of Food Safety

Washington Post - Alejandro Mazzotta is grinding his own beef. But there will be no takers for his meat: The microbiologist will be injecting it with lethal bacteria.

Mazzotta works in the downtown laboratory of the National Food Processors Association, where you're more likely to see white lab coats than gray suits, and where the office refrigerator stocks "biohazards" rather than "Bob's lunch."

Science and politics intersect here in a modern office building at 1350 I St. NW, where the NFPA performs research to provide the government with documentation of food safety policies its members want to see adopted--or rejected.

The lab, for example, generated information to convince the U.S. Food and Drug Administration to extend the use of chlorine dioxide--a sanitizer that can remove harmful pathogens in food--to all kinds of produce. Data from the lab also helped convince the U.S. Department of Agriculture not to require that processing plants test their products for salmonella; NFPA argued that the level of another bacteria, generic E. coli, is a better indication of whether or not a facility is clean.

Relocated last fall from NFPA's former headquarters at 1401 New York Ave. NW at a cost of about $5 million, the lab is staffed with 20 scientists from all over the world. Converting office space to lab space involved meeting stringent safety and environmental requirements, refitting the electrical systems and adding gas lines and floor drains. Two towering ventilators outside provide filtered air.

Aside from providing scientific data in support of or against government proposals, the lab analyzes consumer complaints for member companies ("there's a fly in my canned soup!"), does nutritional analysis (chances are the calorie count on your can of green beans came from here), tests the integrity of cans and packages (why did that rust?) and conducts research on pathogens, including E. coli O157:H7 (the bacteria inoculated into Mazzotta's meat) and listeria monocytogenes (the bacteria linked to hot dogs and deli meats that caused the recent multi-state foodborne disease outbreak and recall).

At a time when foodborne bacteria are making headlines--the latest being the outbreak of listeriosis--the NFPA lab takes on added significance. For here, just as in facilities all over the country, scientists are trying to put together a puzzle about the behavior of pathogens, and unfortunately, it has many missing pieces.

Biohazards Ahead

Unusual precautions are taken by those entering the isolation lab where Mazzotta works: Only those who have received a special vaccination are permitted. The room has negative pressure, meaning air can move in but it can't move out. And that means that none of the dangerous pathogens inside can escape.

A big picture window that looks into the lab allows outsiders to see Mazzotta slicing a large roast, as smoothly and expertly as a chef. Holding a sterile knife, Mazzotta reaches his rubber-gloved hands under a sterile hood to carve the meat. And also under that hood--kind of like a scientific salad bar-- sits the sterilized meat grinder.

"If all butcher shops could use sterile meat grinders in sterile environments, a burger would only cost $50 or $60," jokes David Gombas, senior director for the lab's processing and microbiology departments.

Mazzotta wants to use clean meat, Gombas explains, so that when he inoculates it with E. coli O157:H7, he will be able to look at just that bug, not any other organisms.

E. coli O157:H7, the virulent bacteria responsible for the 1993 Jack-in-the- Box hamburger outbreak, can cause bloody diarrhea, dehydration and kidney failure. Like other foodborne pathogens, it's most problematic for the very young, the elderly and people with weakened immune systems. Although juices, mesclun lettuce mixes, drinking water and other foods have been implicated in outbreaks, undercooked and underprocessed ground beef has caused the most problems.

Mazzotta is looking for the temperature at which the bacteria are killed. And he also wants to find out if salt and acid will affect that temperature. With this information, food manufacturers who make frozen or ready-to-eat beef dishes that contain salt and acidic ingredients will know exactly how long and how hot they must cook their products to ensure that they are safe from this type of E. coli.

So with a pipette, he injects sodium and an acid and phosphate solution into the beef samples. Then, he lowers the ground meat, which he has placed in plastic sealable bags, into a hot water bath. They will be submerged at different temperatures for different amounts of time.

New USDA requirements mandate that manufacturers have a system in place that reduces or eliminates the presence of bacteria, including E. coli O157:H7, listeria monocytogenes and salmonella, three serious pathogens that can inhabit processing plants. Killing them by cooking is one way, and that's why NFPA members asked the lab to find out exactly what it takes to achieve that end.

Although food manufacturers already have their own heating procedures, "sometimes empirical, sometimes historical," says Gombas, they are often based on laboratory studies that haven't taken into account the conditions in processing plants. Those conditions can cause stress on bacteria, which in turn may affect their heat resistance.

Scientists usually experiment with "nice, fat, happy organisms," says Gombas. Not stressed-out ones.

Two of the conditions that can cause stress, as Mazzotta was testing, are the presence of salt and acid. Another is what's called "starvation": When a facility cleans up a plant, wiping all the meat scraps or vegetable bits from the equipment, some bacteria may stay behind. Without those food scraps, bacteria have nothing to eat. When the plant starts processing again, what happens to the "starved" bacteria on the equipment? Are they harder or easier to kill?

Still another condition the lab is looking at is called "heat shock." This refers to a process in which ingredients are heated at low temperatures to make them dissolve or blend better with the final product. This pre-cooking isn't hot enough or long enough to kill the bacteria; it only injures them. But what happens to their heat resistance when they enter the final cooking?

The NFPA lab is finding that when any of the three bacteria are stressed-- under any of these four conditions--they actually become stronger, not weaker. It takes higher temperatures to kill them.

So, for some products, manufacturers will "have to process them a little more," says Mazzotta, several days after he emerges from the isolation lab. All this work "will help us to give conservative recommendations to members to assure that their processing is right," he says.

The Listeria Threat

For listeria, the pathogen associated with the recent deaths and illnesses from processed meats and hot dogs, the cooking process is actually the lesser of two concerns. The main concern is environmental: Found in soil and water, listeria is ubiquitous, attaching itself to factory drainpipes, plastic surfaces, even the spiral threads of screws. It can encase itself in something called a biofilm, a bubblelike coating that makes it undetectable. Its omnipresence means that even fully and properly cooked products can become recontaminated.

Although all details are not yet known, it seems that's what happened at Sara Lee Corp.'s Bil Mar Foods in Zeeland, Mich., which recalled a limited number of hot dogs and deli meats in December because of contamination with listeria. One theory is that contaminated construction dust from air conditioning repairs drifted onto the products.

The bacteria can cause listeriosis, which can result in miscarriages and stillbirths in pregnant women. It can also manifest itself as meningitis, with symptoms of severe headache, neck stiffness and nausea. Listeriosis is rare, but has a high fatality rate.

As of last week, the Centers for Disease Control had reported 97 illnesses from the Bil Mar outbreak, including 20 deaths, in 22 states. Maryland is one of those states, and a spokeswoman with the Maryland department of health said that an elderly woman from Baltimore had been hospitalized in November from the infection.

While the NFPA lab isn't doing any research on environmental reduction of the bacteria, the association did just help gather information from food manufacturers regarding the effective environmental controls they are currently using. That information was recently submitted to the USDA, which is soon planning to release "best practice" guidelines--recommendations to manufacturers on how they can best reduce the organism in their plants.

As for the NFPA lab's work on the heat resistance of listeria and the other bacteria, the results will help establish a precise safety margin for manufacturers. Then hopefully, says Mazzotta, "no surprises will come later."

Keeping Track of Recalls

Some recalls get a lot of publicity, usually because they involve large numbers of products or illnesses. But dozens more occur every year.

Sara Lee's Bil Mar Foods has been in the limelight recently for its recall of hot dogs and lunch meats contaminated with listeria monocytogenes. But in 1998, there were 29 other recalls because of contamination with the same bacteria. Those products included cole slaw, smoked salmon, blueberries and several cheeses.

Since January, there have been 16 USDA recalls, with nine due to listeria. And last week, the FDA announced recalls of seven products it regulates, ranging from alfalfa sprouts associated with an outbreak of salmonellosis to knishes containing eggs that weren't listed on the label.

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