Penicillin and Erythromycin are examples of antibiotics that used to be one-time miracle cures. These drugs and other antibiotics are now less effective because bacteria have become more resistant. VOA's Carol Pearson has more on this growing problem.

A Belgian study shows a link between the use of antibiotics and bacteria that mutates to resist antibiotic treatment. The study used healthy volunteers and two different antibiotics.

After just one course of treatment, the volunteers showed an increase in bacteria in their mouths resistant to the drug they had taken. In some cases, the drug resistant bacteria stayed in the volunteer's mouth for more than six months.

Other studies on antibiotics show that the misuse of these drugs is causing these drugs to be less effective.

Dr. Marc Lipsitch from the Harvard School of Public Health says, "It's truly human medical use of antibiotics that is driving this."

Part of the problem lies with patients who do not complete the full course of their treatment.  This allows any bacteria still alive to mutate and become more resistant to the antibiotic taken.

Doctors who over-prescribe these drugs are also part of the problem. Another study shows that hospitals that control the use of antibiotics are more likely to control antibiotic resistance.

Doctors often prescribe antibiotics before or during surgery to prevent infection. They also prescribe a specific antibiotic after a culture shows which drug would best combat the infection.

But some doctors prescribe an antibiotic without taking a culture. 

According to this study, that is where the problem lies. Dr. Stuart Levy with Tufts University School of Medicine says, "We are creating, without knowing it, our own kinds of weapons of mass destruction.  That is, those that can take lives because we can't treat them."

Resistant bacteria can lead to deadly illness and increased complications. The Belgian researchers say their study should be a vital warning to doctors that the misuse of antibiotics can have dire consequences for their patients and for others as well.

Video courtesy of the National Community Pharmacists Association