SIOUX CITY, Iowa -- Margaret Lamkin doesn’t visit her grandchildren much anymore. She never flies. She avoids wearing dresses. And she worries about infections and odors.

Three years ago, at age 87, Lamkin was forced to wear a colostomy bag for the rest of her life after a virulent meat-borne pathogen destroyed her large colon and nearly killed her.

What made her so sick? A medium-rare steak she ate nine days earlier at an Applebee’s restaurant.

Lamkin, like most consumers today, didn’t know she had ordered a steak that had been run through a mechanical tenderizer. In a lawsuit, Lamkin said her steak came from National Steak Processors Inc., which claimed it got the contaminated meat from a U.S. plant run by Brazilian-based JBS – the biggest beef packer in the world.

“You trust people, trust that nothing is going to happen,” said Lamkin, who feels lucky to be alive at 90, “but they (beef companies) are mass-producing this and shoveling it into us.”

The Kansas City Star investigated what the industry calls “bladed” or “needled” beef, and found the process exposes Americans to a higher risk of E. coli poisoning than cuts of meat that have not been tenderized.

The process has been around for decades, but while exact figures are difficult to come by, USDA surveys show that more than 90 percent of beef producers are now using it.

Mechanically tenderized meat is increasingly found in grocery stores, and a vast amount is sold to family-style restaurants, hotels and group homes.

The American Meat Institute, an industry lobbying group, has defended the product as safe, but institute officials recently said they can’t comment further until they see the results of a pending risk assessment by the meat safety division of the U.S. Department of Agriculture.

Although blading and injecting marinades into meat add value for the beef industry, that also can drive pathogens – including the E. coli O157:H7 that destroyed Lamkin’s colon – deeper into the meat.

If it isn’t cooked sufficiently, people can get sick. Or die.

There have been several USDA recalls of the product since at least 2000, and a Canadian recall in October included mechanically tenderized steaks imported into the United States, but it’s not clear how many people were sickened.

In a 2010 letter to the USDA, the American Meat Institute noted eight recalls between 2000 to 2009 that identified mechanically tenderized and marinaded steaks as the culprit. Those recalls sickened at least 100 people.

But food safety advocates suspect the incidence of illness is much higher.

An estimate by the Center for Science in the Public Interest, an advocacy group, suggests that mechanically tenderized beef could have been the source of as many as 100 outbreaks of E. coli and other illnesses in the United States in recent years. Those cases affected more than 3,100 people who ate contaminated meat at wedding receptions, churches, banquet facilities, restaurants and schools, the center said.

But that’s just one of the key findings from The Star’s investigation, which examined Big Beef’s processing methods, the use of drugs in cattle and the hazards they can pose for human health.

The Star examined the largest beef packers including the big four – Tyson Foods of Arkansas, Cargill Meat Solutions of Wichita, Kan., National Beef of Kansas City, Mo., and JBS USA Beef of Greeley, Colo. – as well as the network of feedlots, processing plants, animal drug companies and lobbyists who make up the behemoth known as Big Beef.