Health: Bacteria proving resistant to drugs

Illnesses caused by bacteria resistant to antibiotics are growing around the world and are spreading beyond hospitals into the community. Jeremy Laurance, Health Editor, reports on how the over-use of medicines has irretrievably altered the microbiological environment.

Public health experts are becoming increasingly alarmed at the threat to world health from the emergence of new strains of bacteria that cannot be destroyed by antibiotics.

Fears have been fuelled by the discovery of a bug in Japan last May and in the US in July resistant to the antibiotic, vancomycin, which is normally the last line of defence against it. The bug was an unusual strain of the MRSA bacterium (methycillin-resistant staphylococcus aureus) which is a common cause of hospital infections in Britain.

An international conference organised by the Government Public Health Laboratory Service in London yesterday considered measures to stem the rise in resistant strains. Professor Brian Duerden, deputy director of the service, said the seemingly uncontrolled increase in resistance presented a major to challenge to medical practice and to the community at large.

"There have been some vancomycin resistant enterococci [bacteria] in some hospitals in London that are almost untreatable. It is very worrying," he said, adding that it was not just a hospital problem but was now being seen in the community. "MRSA-infected patients are discharged from hospital with increasing speed and then transferred repeatedly between community facilities such as nursing homes and day care centres."

One bug which first emerged in Spain, where antibiotics can be bought over the counter and are used in huge quantities, caused an outbreak of infection among children in Iceland and was later transferred to the US. The bug, a strain of pneumococcus resistant to penicillin which causes pneumonia, ear infections, a type of meningitis and the blood infection, septicaemia, now accounts for a quarter of all resistant strains of pneumococcus identified in the US.

Professor Duerden said: "People move and their organisms move with them. With the growth in travel it only needs one rare event on the other side of the world and it becomes an international problem."

Scientists had been warning about the growing problem for 20 years and governments were finally taking notice. In Britain, parliamentary committees are examining the issue and the Chief Medical Officer was also involved. "It has come to the top of the agenda," he said.

It was no good waiting for drug companies to develop new antibiotics. The last new group, the fluoroquinolones0, were introduced 20 years ago and there were no new agents ready to be introduced.

"It is a biological problem. There are limited targets in the bacterial cell that you can aim drugs at. There are a lot of agents that will kill the cell but they will also kill us. The task is to find one that is fatal to the bacterium but not to us."