New way `to keep bacteria at bay`

Washington: Researchers claim new treatments to combat the growing problem of antibiotic resistance by disarming rather than killing bacteria are on the anvil.

A team at Monash University has showed a protein complex, called the Translocation and Assembly Module (TAM), formed a type of molecular pump in bacteria, the `Nature Structure and Molecular Biology` journal reported.

The TAM allows bacteria to shuttle key disease-causing molecules from inside bacterial cell where they are made, to the outside surface, priming the bacteria for infection, say the scientists.

Team leader Joel Selkrig said the work paves the way for future studies to design new drugs that inhibit this process.
"The TAM was discovered in many disease-causing bacteria, from micro-organisms that cause whooping cough and meningitis, to hospital-acquired bacteria that are developing resistance to current antibiotics.

"It is a good antibacterial target because a drug designed to inhibit TAM function would unlikely kill bacteria, but simply deprive them of their molecular weaponry, and in doing so, disable the disease process.

"By allowing bacteria to stay alive after antibiotic treatment, we believe we can also prevent the emergence of antibiotic resistance, which is fast becoming a major problem worldwide," Selkrig said.

The team showed the TAM was made of two protein parts, TamA and TamB, which function together to form a machine of molecular scale. They compared normal virulent bacteria to mutant strains of bacteria engineered to have no TAM.

"We noticed that proteins important for disease were missing in the outer membrane of the mutant bacteria.

The absent proteins help bacteria to adhere to our bodies and perform disease-related functions," Selkrig said.