People use drugs to fight bacteria, but now bacteria is learning to fight back. Bacteria is becoming resistant to antibiotics commonly used to kill them, making them harder to wipe out and rendering certain antibiotics less effective than before.

Methicillin-resistant Staphylococcus aureus, a bacterium responsible for some recent deaths, is the most visible in the list of bacteria that are becoming resistant to the drugs used to combat them, but it is not the only one on the list. Some other diseases, including some sexually transmitted infections, are becoming resistant to antibiotics, said James Dickson, professor of animal science.

“I think it’s a concern,” Dickson said. “Most bacterium are incredibly adaptive. If you give them a challenge like an antibiotic, given the fact that we have billions and billions of them, sooner or later one of them will figure out how to live with it.”

Bacteria adapt by a process of natural selection. When a bacterium survives the antibiotics through genetic traits, it reproduces and passes that trait on to its daughter cells. It can also pass the resistance genes on to other bacteria in DNA packets exchanged between bacteria.

Dickson said bacteria in soil make antibiotics and other bacteria become resistant to that as well.

“Resistance to antibiotics is something that occurs naturally in the environment, but we seemed to have encouraged the spread of it into other bacteria by the use of antibiotics,” said Joan Cunnick, associate professor of animal science.

Incorrect and overuse of antibiotics are the contributing factors to the growth of resistance.

“If antibiotics are given inappropriately, that causes a lot of the problems that we have right now with people not taking as we have prescribed,” said Jo Mostrom, microbiology supervisor at Mary Greeley Medical Center.

Dickson gave an example where someone gets a bacterial infection and they are prescribed 10 days of antibiotics. After about five days, they feel better and stop taking it. Then the surviving bacteria with resistant traits can continue to grow and reproduce. Antibiotics are needed to wipe out enough of the bacteria to allow the body to kill the rest.

Another contributing factor was doctors who used to prescribe antibiotics to patients who came in with viral infections, such as colds. This was to prevent the patient from getting anything else while they had the cold. However, it allowed the bacteria to build up resistance to the antibiotics.

“We don’t do that anymore. There’s kind of a shift in the philosophy,” Dickson said.

Iowa State is one of several universities involved in research concerning drug-resistant bacteria, said Qijing Zhang, associate professor of veterinary microbiology and preventive medicine.

ISU currently has research going on involving the study of drug-resistant bacteria in foods and animals and the emergence of drug-resistant bacteria, Zhang said.

“The long-term goal for everybody is to find ways to slow down or control resistance,” Zhang said. “I will say we’re making successes, gradual successes. We’re making solid progress, but we’ve not achieved the goal yet.”

Steffen Schmidt, university professor of political science, talked about what the government should do.

“I believe that the federal government needs to step up to the plate quickly and aggressively on a number of potential threats that could devastate the United States and then would pose a serious national security problem,” Schmidt said. “Avian flu, drug-resistant bacteria and super viruses are three of these areas.”

Schmidt said there are federal programs for addressing these concerns through Homeland Security.

“Let’s just say that I don’t see that it is probably going to get better pretty soon. We have problems with it and the organisms aren’t going to go away,” Mostrom said.

Mary Greeley Medical Center is keeping track of the infections that come in and monitor what the organisms do to help the physicians better treat the patients.

Cunnick said people should only take antibiotics when they need them and finish the prescription without giving any to anybody else. They should not expect to always get antibiotics for any illness.