We found antibiotic-resistant bacteria –
and traces of a veterinary drug.
Our analysis of
pork-chop and ground-pork samples from around the U.S. found that Yersinia
enterocolitica, a bacterium that can cause fever, diarrhea, and abdominal pain,
was widespread. Some samples harbored other potentially harmful bacteria,
including salmonella. And there are more reasons to be concerned about “the
other white meat.”
Some of the bacteria
we found in 198 samples proved to be resistant to antibiotics commonly used to
treat people. The frequent use of low-dose antibiotics in pork farming may be
accelerating the growth of drug-resistant “superbugs” that threaten human
health.
About one-fifth of the
240 pork products we analyzed in a separate test harbored low levels of the
drug ractopamine, which the U.S. approved in 1999 to promote growth and
leanness in pigs. It’s commonly used in pigs raised for food in the U.S. but is
banned in the European Union, China, and Taiwan. Our food-safety experts say
that no drugs should be used routinely in healthy animals to promote growth.
Here are details from our tests:
Yersinia
enterocolitica was in 69 percent of the tested pork sample. It infects about
100,000 Americans a year, especially children. We found salmonella,
staphylococcus aureus, or listeria monocytogenes, more common causes of
food-borne illness, in 3 to 7 percent of samples. And 11 percent harbored
enterococcus, which can indicate fecal contamination and can cause problems
such as urinarytract infections.
Some of the bacteria
we found were resistant to multiple drugs or classes of drugs. That’s
worrisome, because if those bugs make you sick, your doctor may need to
prescribe more powerful (and expensive) antibiotics.
Ground pork was more
likely than pork chops to harbor pathogens. That’s to be expected, since
grinding meat provides another opportunity for contamination.
Some antibiotic claims
you’ll see on packaging are misleading. And a “no hormones added” claim might
be true but is meaningless, because hormones aren’t allowed in pork production.
Bugs in pigs.
All animals (humans
included) have bacteria on their skin and in their gastrointestinal tract. Some
are beneficial, including the probiotic kind, which help digestion. Others,
such as salmonella, can be harmful to people, but affected animals might not
become ill. Confining animals in less-than-clean quarters can allow bad bacteria
to proliferate.
An animal’s muscles
(meat), blood, and brain are normally sterile. But during slaughter and
processing, meat can become contaminated with bacteria from the animal’s skin
or gut and from workers, equipment, or the environment. Contamination is
especially likely to occur if processing lines run too fast or if sanitary practices
aren’t followed. Once bacteria are on meat, improper storage can encourage them
to multiply.
To minimize
contamination, the federal government requires processors of meat poultry, and
seafood to create safety and inspection procedures collectively known as HACCP
(pronounced hass-ip), which stands for Hazard Analysis & Critical Control
Points. Implemented for meat and poultry plants in 1997, HACCP is officially
the consumer’s first line of protection against contaminated pork. However, in
Spector’s spot-test for a limited number of pathogens. Yersinia enterocolitica,
for example, isn’t among them. And the Department of Agriculture can’t require
a recall if HACCP plans fail to meet goals.
“Very low
contamination levels in hog carcasses indicate that companies’ practices are
adequately controlling pathogens,” a USDA spokeswoman told us. But our tests
showed that some harmful bacteria can make their way into your kitchen.
Moreover, the bacteria
we found often continued to multiply even in the presence of some drugs
designed to kill them or stop them from reproducing. Thirteen of 14
staphylococcus samples we isolated from pork were resistant to one or more
antibiotics. So were six of eight salmonella samples, 12 of 19 enterococcus
samples, and 121 of 132 Yersinia samples. One sample was identified as MRSA, a
drug-resistant and sometimes fatal staph.
Pigs on drugs
Some 80 percent of all
antibiotics sold in the U.S. are given to animals raised for food. Often, those
drugs aren’t used to treat infections but are fed continuously in low does to
promote growth and prevent infections that can spread in the cramped quarters
in which most farm animals live a single barn from a large hog-production
facility can hold 2,000 or more pigs, creating ideal conditions for the spread
of antibiotic – resistant bacteria.
Many samples of pork harbored Yersinia
bacteria.
“When you give
low-dose antibiotics for growth promotion or for prophylaxis of infection, you
end up killing off the susceptible bacteria, whether they’re E. coli,
salmonella, campylobacter, or other bacteria,” says Robert S. Lawrence, M.D.,
director of the center for a Livable Future at the Johns Hopkins Bloomberg
School of Public Health in Baltimore. “And you continue to select for those
bacteria that, through spontaneous mutations or transfer of genes from other
resistant bacteria, allow them to be resistant to antibiotics.” Lawrence cited
recent laboratory research at Boston University suggesting that the continual
exposure to low doses of antibiotics cause enough stress in bacteria to
increase the rate of spontaneous mutations that render the bugs resistant to
drugs, a process known as mutagenesis.
Mutant bacteria in
animals can cause not only foodborne illness but also other treatment-resistant
problems, such as infections of the skin or urinary tract. That’s because the
bugs don’t just end up in the meat you buy. They can also wind up in fertilizer
or contaminate the environment. And they can spread from person to person.
Another drug fed to
animals, ractopamine, is given to as money as 60 to 80 percent of pigs raised
in the U.S., by one estimate. It was originally developed (but never approved)
as an asthma treatment for humans and was later found to boost pigs’ growth and
lean muscle mass.
The U.S. pork industry
says ractopamine is safe. “Ractopamine is approved and used in 26 other
countries, including some of the Asian countries,” says Dave Warner, director
of communications for the National Pork Producers Council, an industry group.
“The issues with China and Taiwan have nothing to do with the safety of the
product. Countries that have banned pork or meat from animals fed ractopamine
are doing it to protect their domestic pork industries. This is not about food
safety.”
“Ractopamine is approved and used in 26
other countries, including some of the Asian countries,”
The European Food
Safety Authority, which advises the European Union on food policy, concluded
that it couldn’t establish a safe level for ractopamine in food after reviewing
the only study of its effect on humans (involving just six men). But it noted
that drugs like ractopamine can cause restlessness, anxiety, a fast heart rate,
and other conditions. And FDA documents show that it increases the risk of
injury and lameness in pigs.
Warner emphasized that
the U.S. pork industry uses ractopamine at levels that meet FDA and
international food-safety standards. Indeed, although we found the drug at
detectable levels in about 20 percent of our 240 pork samples, all had less
than 5 parts per billion. That’s well below the FDA’s limit of 50 ppb in muscle
tissue and the international limit of 10ppb adopted in July 2012 by the Codex
Alimentarius Commission, a program of the United Nations.
Warner emphasized that the U.S. pork
industry uses ractopamine at levels that meet FDA and international food-safety
standards. Indeed
We asked three of the
nation’s largest pork producers- Smithfield Foods, Tyson, and JBS USA, which
makes the Swift Premium and Swift Premium Natural brands – about their use of
ractopamine. Keira Lombardo, vice president of investor relations and corporate
communications at Smithfield, called it “a safe and effective FDA-approved feed
supplement that has been widely used in the hog framing industry for many
years”. Lombardo and a JBS spokeswoman, Margaret McDonald, told us their
companies produce pork with and without ractopamine according to their
customer’s specifications.
Some food companies,
including Chipotle Mexican Grill, Nian Ranch, and Whole Foods, say they don’t
sell any meat from pigs raised with ractopamine. Consumers Union, the policy and
advocacy arm of us, has pressed for a ban of the drug, citing insufficient
evidence that it’s safe.