October 2, 2008

Penicillin DNA Sequence Brings Hope For New Antibiotics

The DNA sequence of the fungus that produces penicillin has been deciphered by Dutch researchers.

This monumental discovery is just in time for the 80th anniversary of the breakthrough of penicillin, discovered by Sir Alexander Fleming.

Researchers hope that discovering the genome of Penicillium chrysogenum will increase further development of new antibiotics to help surmount the problems of resistance.

Penicillium chrysogenum is employed in the manufacture of antibiotics such as amoxicillin, ampicillin, cephalexin and cefadroxil. The use of penicillin in destroying bacteria was found in 1928 after mold spores unintentionally tainted a Petri dish in a laboratory. Further work on the drug revealed it was safe for humans to use.
Approximately one billion people take penicillin every year world wide. However, antibiotic resistance is becoming more and more problematic.

Experts have frequently warned against the overuse of antibiotics and cautioned there is a vital need for the industry to try to create new drugs.

Researchers also stated that in addition to fighting resistance, the genome sequence could also improve the overall manufacturing of antibiotics.

Dr Roel Bovenberg, a researcher at DSM Anti-Infectives, noted that the four-year project had brought up "several surprises" that they were further investigating in cooperation with academics.

"It provides insight into what genes encode for, know-how in terms of manufacturing and new compounds to be identified and tested," he said. "There are genes and gene families we did not think would be involved in biosynthesis of penicillin - they weren't on our radar so that is our follow-up work."

Professor Hugh Pennington, who is an expert in bacteriology at the University of Aberdeen, stated that the genome sequence could lead to the improvement and creation of new antibiotics.

"If we understand the genome we might be able to manipulate the genes," Pennington stated.

The professor noted that in the past antibiotics had been discovered by simply looking at fungi production; recently scientists had been working to modify current treatments.

"All the easy targets have been hit by one drug or another so it's proving very difficult to find new compounds and we're going to need some lateral thinking," he said. "If the genome helps to do antibiotic development quicker, then that can only be a good thing."

The complete work on the 13,500-gene sequence will be published in October's Nature Biotechnology.


Image Caption: Scanning electron micrograph of conidiophores of Penicillium chrysogenum, the mold from which penicillin was isolated. This Penicillium species, among others, was used to test a DNA barcoding system to identify fungi. The barcoding technique utilized a segment of the mitochondrial cytochrome c oxidase 1 (CO1) gene, which is the core barcode region for animals that has so far not been assessed in fungi. The development of a fungal DNA barcoding system would provide a major advance in accurate and rapid species identification. See the article by Seifert et al. on pages 3901"“3906. Image courtesy of Robert A. Samson/PNAS


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