Humans vs microbes: the ASM goes to war

Microbiology is in ferment, says Dr Jan Tennent, and the next decade is likely to see major gains in the perennial war between humans and their microbial nemeses -- viruses, bacteria and parasites.

Tennent chaired the local organising committee for the annual scientific meeting of the Australian Society of Microbiology in Melbourne this week.

She told Australian Biotechnology News that new-wave sciences like genomics and proteomics, and new technological advances, are yielding unprecedented insights into what makes microbes tick -- and new weapons to counter them.

Tennent said the ASM 2002 meeting, 'Microbiology, Macrotechnology, Melbourne', had seen a marked change in emphasis for Australia's biggest microbiology conference.

The conference is giving strong emphasis to communication with the community, not just between peers -- Tennent said extra sponsorship from industry had allowed her committee to make it a media event, to inform the community about advances in microbiology.

"We teed speakers up in advance, and asked them to look at their research from the community's perspective -- we wanted to take them out of their comfort zones," she said.

Tennent said last week's announcement in the international journal Science that a US research team had discovered three cellular proteins that suppressed the HIV virus exemplifies the way in which new technology was accelerating progress in understanding microbes.

The new SELDI-TOF (Surface-Enhanced Laser Desorption and Ionisation -- Time of Flight) mass spectrometry system developed by California-based Ciphergen Biosystems had allowed the team to identify elusive three proteins, called defensins, secreted by infection-fighting T-cells in the blood, that inhibit replication of the HIV virus.

Tennent said genomics projects had now produced complete gene catalogues and maps for around 30 species of bacteria, that were collectively responsible for most of the common bacterial infections in humans.

"It's going to allow us to understand how microbes interact with their hosts, and with the environment, and which bits of the bugs we need to target to disrupt their ability to infect us and cause disease," she said.

"Genomics will also allow us to develop better microbes for bioremediation -- for breaking down chemicals contaminating soil or water.

"We're going to see a new generation of antibiotics that will target specific proteins, or selectively disrupt the activity of bacterial genes, which will put us in a position to outsmart the bugs."

For example scientists have now identified 30 to 40 genes in the O157 strain of the bacterium Escherichia coli, that differ from the normal E. coli strains that live in the human gut.

The O157 strain, believed to have originated in beef cattle, causes 'hamburger disease' in people who have eaten contaminated mince -- it causes severe diarrhoea and kidney damage, and has killed young children.

"We're going to see a large number of new, recombinant (genetically engineered) vaccines for common diseases, and we're likely to see intractable pathogens like the malaria parasite and the tuberculosis bacterium cracked," Tennent said.

"In the veterinary vaccine area, we're likely to see new recombinant vaccine against foot and mouth disease -- given the economic impact of the recent FMD [foot and mouth disease] epidemic in Britain, it's a vaccine that Australia needs now.

"Parasitology remains a big challenge -- there has been a dramatic increase in resistance to the chemicals that primary producers use to control parasites.

"Parasites are extremely complex and perfectly adapted to living with their hosts, but with genomics and proteomics, we can study how they do it and target their Achilles' heels."

Tennent predicts that new antibiotics will emerge from genomics and proteomics research that allow hospitals to control potentially deadly strains of bacteria like Staphylococcus aureus, that have become resistant to virtually all current antibiotics.

"But it won't be enough just to put in these new-generation antibiotics. We need to combine infection control and patient-management systems with clever design and engineering in our hospitals."

Bacteria may also be engineered to secrete probiotics -- substances that will enhance human health by keeping the human gut flora in balance, and countering infection."