A POTENTIALLY lethal form of drug-resistant "golden staph" bacteria has arrived in Australia from the US and is spreading rapidly in the community, prompting a call for doctors to take skin infections more seriously - especially in younger people - in case they are caused by the new strain.

The strain, known as USA300, is a tougher variant of the widespread golden staph infections often acquired in hospital after surgery, especially among frail, elderly people. But USA300 frequently affects otherwise healthy young people, causing infections that deteriorate rapidly and are hard to treat.

Of 61 cases of USA300 identified in Western Australia since the new strain first emerged in 2003, 35 of the cases were in 2007 - indicating a likely acceleration in the rate of new infections, according to research presented to a conference earlier this year by Keryn Christiansen, an infectious diseases specialist at the Royal Perth Hospital.

The superbug - which is becoming increasingly resitant to antibiotics - can be sexually transmitted, causing boils and abscesses on the buttocks and genitals. It can also cause a form of pneumonia that may quickly result in irreversible lung damage and death.

Dr Tom Gottlieb, the vice-president of the Australasian Society for Infectious Diseases, said doctors should suspect USA300 when they treated skin infections in young people, indigenous people, those who had travelled overseas, and in anyone whose condition did not respond to treatment with the usually recommended antibiotics. They should order cultures to identify the bug, and lance and drain abscesses to hasten healing, he said.

Dr Gottlieb, from Concord Hospital, said he had identified a case of USA300 in a 37-year old man from the US, in Australia as a tour crew member for a rock band. The case, "highlights the ease of international spread of microorganisms," said Dr Gottlieb, describing it in today's Medical Journal of Australia . But the man had initially been discharged from hospital with ineffective antibiotics, and the cause of the infection would never have come to light had specialists not run extra tests.