New Ways of Combating Antibiotic Resistance

Author:  Schuck Kirsten

Date:  May 2007

New research gives hope to finding a way to beat antibiotic resistance. A research team at the University of Wisconsin-Madison has isolated four compounds which offer antibacterial activity close to some of the most potent antibiotics available. The findings of this team are published in the April 27th edition of Chemistry and Biology.

Resistant bacteria are a growing and imminent problem. According to Helen Balckwell, the lead investigator of this research, "Strains are emerging that are resistant to all known antibiotics," she says. "This is not a problem that's going to go away - and actually it's just going to get worse. There's a sense of urgency."

The research team which includes Blackwell, two graduate students, and one former graduate student, has come up with methods to synthesize molecules quickly and efficiently. They are then able to test these molecules for antibiotic resistance.

In testing these new molecules quickly, there is the possibility to create new drugs to try and remain a few step ahead of the bacteria. Some bacteria evolve so quickly that even the newest antibiotic, linezolid, was only around for about one year before bacteria became resistant to it.

The strategy of the Blackwell group is to synthesize different molecules one compound at a time. Molecules are built on a thin, flexible sheet and new compounds are added one at a time. The end result is a molecule about the size of a pencil eraser. Molecules are made in groups of 50 to 200, and the whole process takes about 2 days to complete.

Newly synthesized molecules undergo a series of tests which allow their potency to be tested against a variety of strains of bacteria of varying strengths.

The efficiency of this process, and the ability of many compounds to be made and tested at once, is a great advancement. Typically, only about two percent of the synthesized molecules present promising possibilities, but since so many more compounds can be made and tested, the chances of finding an effective molecule are increasing.

So far, the researchers have isolated four compounds that seem promising. They are about as effective as antibiotic drugs already on the market. These compounds are composed of chemical groups which have previously not been used to fight bacteria. Because they are new sources for fighting bacteria, they may be able to keep up resistance for longer periods of time than the compounds currently used. There may only be subtle structural differences that make these drugs effective, but they can be the difference between an effective treatment and an ineffective one.

While finding these bacteria-killing compounds is only the first step, it is an important one. From here drugs can be produced, and potent antibiotic agents can be made.

We can gather information on how to improve them fairly quickly," Blackwell says. "Hopefully we will find new approaches for anti-bacterial therapies."

Written by Kirsten Schuck