Scientists sequence Nature's antibiotic factory

The genome sequence of Streptomyces coelicolor, one of the family of common soil bacteria that produce more than two thirds of the world's antibiotic medicines, is published in the journal Nature.

Streptomyces are almost ubiquitous in the soils and are responsible for its familiar ‘earthy’ smell. The genome data, collected by British scientists from the John Innes Centre and The Wellcome Trust Sanger Institute, is already being used in research that will help develop new types of antibiotics, anticancer agents and other beneficial chemicals.

“At over eight and a half million base pairs it has the largest completely sequenced bacterial genome to date and has a staggering 7825 genes – about half as many as a fruit fly. It is also, like the genomes of flies and humans, a linear DNA molecule, whereas most bacterial genomes are circular.”

Dr Stephen Bentley Project leader at the Wellcome Trust Sanger Institute

New types of antibiotic are urgently needed to help counter the growing threat from so-called ‘superbugs’, such as MRSA (methicillin-resistant Staphylococcus aureus), that are resistant to conventional treatments. Last month, heart surgery at the Edinburgh Royal Infirmary was suspended after 13 patients in the cardiac unit were found to have MRSA. In 1992, 3 percent of blood poisoning cases were caused by MRSA. By 1999 that proportion had risen to 37 percent and by 2000 nearly 50 percent of cases were caused by the bug

“Remarkably, we are enormously dependent on this common soil bacterium – it produces more than two-thirds of the antibiotics we use today to fight infection, as well as other valuable medical chemicals such as anti-cancer agents. Analysis of the genome has brought valuable new information in the quest to make new antibiotics as well as bringing new insights into the evolution of bacterial chromosomes.”

Dr Stephen Bentley

Streptomyces are harmless cousins of the bacteria that cause tuberculosis, leprosy and diphtheria. With the new sequence, many common features of all four genomes have been revealed and there is a real hope that studying these features in Streptomyces will provide new insights into these infamous diseases.

With 7,825 genes, Streptomyces coelicolor is the largest bacterial genome to be sequenced. The project began in 1997, cost £2 million and was funded by the Biotechnology and Biological Sciences Research Council and The Wellcome Trust.

More information

1. The reseach is published today Thursday 9 May 2002 in Nature magazine.
2. Streptomyces are an almost ubiquitous family of bacteria highly adapted to living in the soil – a nutritionally, physically and biologically complex and variable environment. The Streptomyces genome contains an unprecedented proportion of regulatory genes – predominantly those likely to be involved in responding to external stimuli and stresses.
3. As well as being used to produce over two thirds of naturally derived antibiotics in current use, Streptomyces are used in the production of many other pharmaceuticals such as anti-tumour agents and immunosuppressants. In all, Streptomyces make over 6,000 different chemicals.
4. Comparable genomes: Escherichia coli 4,000 genes, yeast 6,000 genes, fruit fly 13,000 genes, worm 18,000, thale cress 26,000 and human about 30,000 genes.