Two studies find bad news for meat eaters: Bacteria even USDA inspectors don’t look for.

This is a rough month for carnivores and others who like eating safe meat.

Two studies tested beef, chicken, pork and turkey purchased from groceries in six cities from Seattle to Ft. Lauderdale.

What they found was enough to make a caveman queasy.

The latest study conducted in Seattle is by Mansour Samadpour, a leading bacterial microbiologist who heads the Institute for Environmental Health, which is a national network of food-safety laboratories.

Staphylococcus aureus Photo by McGill University

Samadpour ‘s staff purchased 100 packages of chicken parts and fryers from 10 Seattle-area groceries during March. The analysis of these samples found that 65 percent of the birds tested had Campylobacter, 19 percent had Salmonella, 2 percent had E. coli or Listeria. USDA inspectors at all slaughterhouses or processing plants watch for these poisonous bacteria.

But Samadpour also found that that an alarming number of the poultry samples had bacteria that the government doesn’t look for: Staphylococcus aureus.

S. aureus is a fast-acting toxin, often causing gastrointestinal symptoms within 30 minutes, and, according to the Centers for Disease Control, it sickens at least 240,000 people a year.

Samadpour told me last night (4/18/2011) that 10 percent of the samples contained the more worrisome Multidrug-Resistant S. aureus or MRSA. Handling contaminated chicken with a cut or break in the skin is a screaming invitation for MRSA to enter the body.

The study was funded by Seattle food-safety lawyer William Marler, who, as The Food Watchdog reported in the past had commissioned Samadpour’s labs to test 5,000 samples of beef for the presence of non-O157 strains of E. coli.

The findings showed that millions of pounds of beef sold throughout the country were contaminated with strains of dangerous E. coli that the USDA neither outlaws nor apparently cares much about.

Food scientist Mansour Samadpour and food safety lawyer William Marler © Photo Andrew Schneider

“I funded the chicken study because I’m concerned that consumers don’t understand how many pathogens may be on the chicken they purchase and serve to their families,” Marler told me yesterday.

Marler said that he was concerned because one of the samples was contaminated with E. coli 0126, a bacteria usually only found in beef.

All the contamination most likely occurs because of sloppiness in the processing facilities, where the meat comes in contact with feces, which causes most of the dangerous bacteria to flourish, Marler says.

Echoing recommendations from federal food-safety agencies, Marler says great care must be used when handling the uncooked chicken at home. Poultry must be cooked to 165 degrees, which should kill most of the bacteria that leads to food poisoning.

An exception to that rule may well be Staph-contaminated meat because those toxins are far more resistant to heat and must be cooked more thoroughly to be made safe, food-safety experts say.

That fact alone makes the findings of another group of food scientists more troubling.

A nationwide study by the Translational Genomics Research Institute (TGen) published this month in  the journal Clinical Infectious Disease reported on the analysis of 136 samples–80 different brands of beef, chicken, pork and turkey. They were purchased at 26 retail grocery stores in Los Angeles, Chicago, Fort Lauderdale, Flagstaff and Washington, D.C.

Lance Price, senior author of the study, says nearly half of the meat and poultry samples–47 percent–were contaminated with S. aureus. And more bothersome is that more than half of those staph bacteria–52 percent–were resistant to at least three classes of antibiotics.

Drug-resistant strains of S. aureus, are linked to a wide range of human health problems from minor skin infections to life-threatening pneumonia, endocarditis and sepsis.

Scientist Lance Price

The scientist say that that theirs is the first national assessment of antibiotic-resistant S. aureus in the U.S. food supply. Their DNA testing suggests that the food animals themselves were the major source of contamination and the Arizona team identifies overcrowded industrial farms, where food animals are steadily fed low doses of antibiotics, as ideal breading grounds for the contaminant.

“The single most effective way to reduce antibiotic-resistant bacteria in food is to stop feeding millions of animals antibiotics,” Price said in a press conference.

S. aureus infects hundreds of thousands of Americans each year. Prior to the discovery of antibiotics, Staph infections were associated with extremely high mortality rates, Price told me yesterday.

“Our study shows (for the first time) that retail meat and poultry are routinely contaminated with S. aureus that are resistant to multiple antibiotics. These products are potential sources of human exposure and infection from multi-drug-resistant Staph,” said Price who is the director TGen’s Center for Food Microbiology and Environmental Health. “Antibiotics are the most important drugs that we have to treat Staph infections. But when Staph are resistant to three, four, five or even nine different antibiotics — like we saw in this study–that leaves physicians few options,” Price said.

Many food-safety activists have expressed concern over the results of the studies.

“This is a public health risk because these bacteria can cause food-borne illness.  What makes it even more insidious is the fact that this bacteria is resistant to antibiotics. There needs to be a broader sample, though, to ascertain the extent to which this situation is widespread,” Tony Carbo of Food & Water Watch told me.

The American Meat Institute, the industry’s lead lobbying arm, sent me a statement saying that the sample size is insufficient to reach the sweeping conclusions conveyed by the Arizona scientists. AMI further noted that S. aureus is also carried by household pets.

“Despite the claims of this small study, consumers can feel confident that meat and poultry is safe,” said the group’s president James Hodges. “Federal data show that S. aureus infections in people that are caused by food are uncommon.”

What about the almost 250,000 illnesses that CDC attributes to S. aureus in food each year?

AMI finally replied and seemed to indicate that  it wasn’t a lot to worry about.

“While our goal is to get as close to zero foodborne illnesses linked to meat and poultry as science permits, the fact is that the 241,000 estimated human infections with S. aureus from all foods comprise one half of one percent of the total foodborne illnesses that CDC estimates occur annually in the U.S.” said Meat Institute spokesman Tom Super.


–Andrew Schneider





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