The government has set a target to halve MRSA rates
Recent drops in the number of new MRSA infections seem to have stalled, latest figures show.
Cases in England rose by 0.6% between October and December 2007 to 1,087, the Health Protection Agency said.
It comes after a series of continuous drops in infections since April 2006 and may hinder the government target of halving the number of cases by 2008.
HPA experts said variations were not unexpected and the NHS had made huge efforts to combat the infection.
In order to meet the MRSA target, the government says the number of cases needs to drop to 963 cases or less in the quarter April to June 2008.
But opposition parties have accused them of moving the goalposts - it had been widely expected the target would measure the period January to March 2008.
The latest figures represent the period before the £50m deep clean of hospitals which is now almost complete.
Health Minister Ann Keen said there was a 30% reduction in MRSA cases compared with last year indicating the target was "in reach".
"However, one case of avoidable infection is one too many and I am challenging the NHS to make full use of the resources at their disposal to eradicate avoidable infections."
She added the Healthcare Commission is now inspecting each and every acute trust against the Hygiene Code.
The Commission wrote to all acute trusts this week asking them to ensure standards were in place to minimise the risk to patients of catching an infection while in hospital.
Dr Georgia Duckworth, of the HPA, said: "The NHS has faced a great challenge in turning around the seemingly unstoppable rise in MRSA bloodstream infections that we saw throughout the 1990s.
"The substantial decreases seen in recent quarters clearly demonstrate the huge efforts made by our NHS colleagues to combat these infections."
The Health Protection Agency figures also show an apparent fall in cases of Clostridium difficile with an 8% reduction in reported cases in the over 65s from the previous quarter.
However changes in the way hospitals report cases of C difficile, which can cause severe diarrhoea and inflammation of the bowel, means it is not yet clear if rates are actually falling.
Shadow health secretary, Andrew Lansley, said the government's policy on tackling hospital infections was "misguided".
"For years even their own advisers have been telling them that the way to tackle the problem is to identify infected patients as early as possible and then isolate them to make sure others don't catch it.
"But Gordon Brown has stubbornly chosen to put time, money and effort into a deep clean which made a good headline but wasn't backed up by any evidence."
Liberal Democrat health spokesman, Norman Lamb, said the figures cast doubt on government claims to have cracked the problem.
"At best, rates have levelled off and at worst, previous drops were a blip and not part of an overall trend of genuine success in reducing infection rates."