It used to be trichinosis was the big fear when eating pork, but the risk of getting that disease has been largely eliminated. However, Consumer Reports' new lab tests on pork found there are new reasons to take precautions.

Consumer Reports tested almost 200 samples of pork chops and ground pork and found more than two-thirds were contaminated with the bacteria yersinia enterocolitica, which can cause fever and abdominal pain.

"Even more troubling is the vast majority of the yersinia bacteria that Consumer Reports found were resistant to one or more commonly used antibiotics," said Jamie Kopf of Consumer Reports.

The tests also found that a few pork samples were contaminated with other bacteria that can be harmful, including salmonella and staphylococcus and listeria. And again, some of the bacteria were resistant to certain antibiotics.

"Antibiotic resistance is worrisome because it can lead to infections in humans that are more difficult to treat," Kopf said.

Healthy pigs are commonly given low doses of antibiotics to prevent infections and promote growth, which can accelerate the development of drug-resistant bacteria.

A second test of 240 pork samples found that about 20 percent had traces of the drug ractopamine, which is used in pigs to promote growth and make meat lean.

A major pork producer, Smithfield, says ractopamine is "a safe and effective Food and Drug Administration-approved feed supplement that has been widely used in the hog farming industry for many years."

The levels Consumer Reports found were well below the limits set by the FDA. But Consumers Union, the advocacy arm of Consumer Reports, called for ractopamine to be banned claiming there isn't enough evidence that's safe for humans.

Consumer Reports recommends buying pork raised without antibiotics and ractopamine. It's also important to cook pork thoroughly to kill any possible bacteria. Whole pork, such as chops and tenderloin, should be cooked to 145 degrees farenheit. Ground pork needs to reach 160 degrees farenheit.

As for finding pork that has not been given antibiotics or ractopamine, Consumer Reports advised looking for meat labeled "certified organic." Another option is to buy from Whole Foods, which requires producers not to use antibiotics or ractopamine.

For a list of recent stories Marilyn Moritz has done, click here.