Derriford Hospital has complained about intrusion

Six English hospitals were found to have antibiotic-resistant bugs in areas used by patients.

A senior microbiologist told Tonight with Trevor McDonald that it showed the superbug MRSA was at the hospitals.

But some of the hospitals disputed the claim, questioning the methodology of the tests and saying it could just be a "harmless" bacteria.

Hospitals targeted were St Mary's Hospital in Paddington, London, where all five swabs taken were positive, while three tested positive at St Helier in Carshalton, Surrey, Milton Keynes General, Worcester Royal Infirmary, and Derriford Hospital in Plymouth.

MRSA can open the bloodstream through open wounds

Two swabs were positive at Oldchurch Hospital in Romford, Essex.

The documentary crew at Derriford said skips of toxic waste were overflowing and used surgical gloves were found on top of a paper bin outside a public lift at the hospital.

The findings come just days after the government appointed a new chief nursing officer with the top priority of ridding hospital wards of MRSA.

All of the hospitals responded by saying they were actively fighting infection.

Analysis offer

Four argued that the presence of MRSA was not proven because the screening tests did not reveal the exact nature of the antibiotic resistant bacteria found.

Derriford, Worcester and St Mary's said their own tests found no MRSA.

Plymouth Hospitals NHS Trust said the documentary team's tests might have picked up another bug, MRSE, which it described as "harmless".

It said its own microbiology department had offered to look at any of the swab results to determine whether they were MRSA, but they were never sent for analysis.

It has lodged a complaint with the executive producer of the programme about the crew's "intrusion into the privacy and dignity of patients".

Some of the sensationalist reporting we have seen recently is causing an unnecessary degree of concern Dr Peter Jenks

Director of Infection Prevention and Control, Dr Peter Jenks, said: "We appreciate that members of the public are concerned about the risks of picking up an infection during a stay in hospital - but some of the sensationalist reporting we have seen recently is causing an unnecessary degree of concern.

"We would like to see a more responsible approach by some parts of the media in reporting the important issue of healthcare acquired infections - one that is informative but not alarmist."

However, Professor Pennington, president of the Society of General Microbiology, said MRSE was actually not harmless.

"In really sick people it can cause quite serious damage and it's quite resistant to antibiotics as well," he told the programme.

He added: "These results are very significant.

"As a group there are enough... strong positives in there to convince me that most of those results are due to MRSA.

"It may be that some of them are due to other bugs, which come through on these tests occasionally - only occasionally - but the majority of them are MRSA."

A spokesman for Tonight With Trevor McDonald said the programme stood by the results of its investigation, which found antibiotic resistant bacteria at six NHS hospitals.

He said: "In each case swabs were taken according to strict scientific procedures by a microbiologist from public areas of the hospitals used by patients and staff."