Human Genome Sciences Inc. said yesterday that it has discovered the genetic blueprint for a bacterium that is a leading cause of pneumonia and meningitis. The breakthrough could help researchers enormously in the race to develop a class of drugs to tackle the growing problem of drug-resistant infections.
Comparing similarities and variations in the blueprints "should collapse the time it takes for drug discovery and help pick better targets on microbes to interfere with their actions," said Craig Rosen, senior vice president for research and development at Rockville-based Human Genome.
The company's detective work on the pathogen, Streptococcus pneumoniae, was completed under a March 1996 agreement with drug giants F. Hoffmann-La Roche Ltd. of Basel, Switzerland, and Hoffmann-La Roche Inc. of Nutley, N.J., and is the fourth microbial genetic blueprint Human Genome has determined.
Under that agreement, Human Genome is due an undisclosed payment for determining the chemical code -- or genome -- of the strep bacterium. The company also got an undisclosed payment for signing the research deal.
Yesterday, Hoffman-La Roche said it had also obtained a nonexclusive license from Human Genome to use the genomic sequence for Enterococcus faecalis, which occurs naturally in the intestines and is a major cause of infection in hospitals, to develop new antibiotics. Hoffman-La Roche will pay an undisclosed signing fee and product royalties.
While determining the sequence of a bacterium's nucleotides -- the four basic chemical building blocks found in all DNA -- is a milestone, the harder work is yet to come: developing new antibiotics or other treatments to battle strep, which, like other human infections, has been showing an alarming resistance to conventional antibiotics.
Scientists believe it is only a matter of time before some infectious bacteria exhibit a resistance to vancomycin, an antibiotic that is considered the "last line of defense" for virulent strains of bacteria.
Hence, the race to develop powerful antibiotics is on at several major pharmaceutical houses.
"We now have the [genetic] sequences for four microbes and it's our belief that this should be a big help in developing a whole new class of drugs to fight these bacterial infections," Rosen said.
Meanwhile, Rosen expects Hoffman-LaRoche researchers to use genomic information on the two microbes to develop drugs that specifically target the bugs.
That would be in sharp contrast to today's antibiotics, which are used on a broad array of microbes -- a factor scientists believe has contributed to bacteria rapidly developing drug resistance.
Elizabeth Silverman, a New York-based genomics industry analyst with Punk, Ziegel & Knoell, an investment bank, says the discovery is significant on several fronts.
For one, it opens yet another window in scientists' understanding of what makes strep and other microbes tick, and gives them an edge in efforts to develop new treatments.
"Pathogenic resistance to antibiotics is frightening to think about. These are airborne diseases and ones which we can pick up in food. They are pretty easy to catch," Silverman said.
"Imagine the risk to surgical procedures if we start seeing a lot of antibiotic resistance."
The discovery also marks a potential revenue source for Human Genome in the near future, since development and clinical testing of bacteria-fighting drugs historically takes less time than that of more complex diseases, such as cancer.
Those revenues should help sustain the company while it shifts from being a purely research-based outfit to one that develops its own line of drugs and other treatments from its storehouse of information about human genes, Silverman said.
"This is further evidence that Human Genome's pathogen program is on course," she said.
Pub Date: 7/09/97