New generation of antibiotics launch assault on superbugs

A new generation of antibiotics to combat hospital "superbugs" as well as tuberculosis and salmonellosis are being developed by Dr Jim Naismith of St Andrews University, Scotland.

Superbugs such as MRSA (methicillin-resistant staphylococcus aureus) and other antibiotic-tolerant bacteria are found increasingly in hospital intensive-care units, where the most vulnerable patients are treated.

In many developing countries, drug-tolerant bacteria are now endemic.

Bacterial infection has re-emerged as a serious health problem, particularly because pathogens develop resistance to conventional antibiotics.

Dr Naismith and his colleagues are using micro-organisms and structural biology to study the synthesis of carbohydrates as a way to creating drugs to combat new, virulent forms of bacteria.

"Carbohydrates are another name for sugars," said Dr Naismith. "Bacteria make carbohydrate molecules that are not found in humans. We have worked out how they make two sugars in particular - L-rhamnose and D-galactofuranose. Several enzymes [protein molecules] which we have characterised make these sugars."

The painstaking experimental research involves determining the full three-dimensional structure of protein molecules. In essence, the protein is magnified one hundred million times.

This allows Dr Naismith and his colleagues to see exactly how the protein works and, more importantly, how the structure can be altered to stop it operating.

"Bacterial disease is a serious problem," said Dr Naismith. "While we are looking for antibiotics that could combat MRSA, we are also focusing on tuberculosis that is re-emerging as a significant concern in the United Kingdom.

"Multi-drug resistant tuberculosis is also prevalent in many parts of the world. Salmonellosis is another of our interests."

nzherald.co.nz/health