U Receives Grant to Study Drug-Resistant Microbes

Recent usage of antibiotics as a prevention against anthrax has revived concerns about the emergence of drug-resistant bacteria.

Excessive and incorrect use of antibiotics have existed since the ’40s, when penicillin was first mass-produced. The problem persisted and multiplied because of the increased dependance on antibiotics.

A recent national survey of pediatricians estimates that as much as 50 percent of all antibiotic usage is inappropriate. Such figures have health officials worry about battling future outbreaks of infectious diseases.

“Forty percent of pneumococci [a type of bacterium responsible for diseases such as meningitis and pneumonia] are showing some resistance to antibiotics,” said Dr. Matthew Samore, associate professor of internal medicine. “That’s 10 times the figure from five to 10 years ago.”

Samore leads a study investigating drug-resistant microbes in rural communities in Utah and Idaho as part of a $6.6 million grant from the Centers for Disease Control and Prevention (CDC) announced this week.

“It’s a less studied environment,” Samore said. It’s easier to study because researchers can isolate the factors contributing to resistance in more isolated populations.

Samore’s background is in infectious disease and epidemiology. He has studied drug-resistance at large urban teaching hospitals. When he moved from Boston to Utah, he started working in a project studying drug-resistant pneumococci in Price and Delta, and became more involved with rural medicine.

Another reason for targeting rural communities is that the study is part of a larger research effort including an agricultural component. The widespread use of antibiotics in animal feed can also lead to drug-resistant bacteria. The microbes can be transmitted by contact with the soil, or eating or handling the animal as food.

“The funding came from Congress [through the CDC] who made a decision to target rural communities,” Samore added.

Samore’s strategy is to track the pattern of antibiotic prescription and resistance, then alter habits and misconceptions through training and education.

Bacteria can develop drug resistance because mutations occur frequently in most micro organisms. Very rarely would a mutation lead to drug-resistance, but because application of antibiotics select for bacteria with these mutations and the surviving variants can multiply opportunistically, drug resistant strains can arise and spread quickly after introduction of an antibiotic.

Frequent misuse speeds up the process further. Antibiotics are ineffective against viruses but are often prescribed for viral infections, such as the common cold; and broad-spectrum antibiotics, which can kill several types of bacteria, are often prescribed when there is a better, more strain-specific drug available.

Patients often demand antibiotics because they felt better after receiving the medication for a previous ailment and then falsely attribute their improvement to the antibiotics. Physicians also make presumptive diagnoses of infections, Samore said, because there is no test to show an infection is viral.

“Doctors say it’s the patients’ fault, and patients say it’s the doctors’ fault,” Samore said. “It’s nobody’s fault. We have a system that leads to over-prescribing.”

To help change prescription habits, Samore plans to supply rural physicians with personal digital assistants equipped with decision-support software and knowledge bases of antibiotics.

The project contracted with Theradoc, a Salt Lake City company, to customize an existing application called Antibiotic Assistant for this study.

Samore anticipates a long campaign. The current CDC grant will last three years.

“You can’t do just a television spot and change everything,” Samore said. “It takes more than that.”

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