The hospital recorded only 10 cases of MRSA infections in patients' blood during the last six months, compared to 16 recorded incidents between October 2005 and March last year.
Hospitals must reduce the level to one case or less of the superbug each month by April 2008 to meet health targets.
Dr Tony Bentley, NGH consultant microbiologist, said: "With MRSA we are now back on trajectory.
"Over the last four or five months things have improved and we are now on target. They are the best months we have had for some time."
There were four reports of MRSA infections in blood between October and December last year, and six between July and September, and Dr Bentley believed the decrease would continue.
The hospital screens high-risk patients when they arrive at hospital to see if they are carrying the bacteria and uses specialist creams or places them in private rooms to stop them passing it to other patients.
Dr Bentley added: "The issue is that we are making it everybody's business, not just infection control's, but doctors, nurses, managers and all the staff and patients."
A Department of Health memo leaked this week warned that the NHS in general was not on track to hit its April 2008 target, to halve the number of MRSA bloodstream infections from its 2004 rate.
But Dr Bentley said the hospital faced a bigger problem than MRSA, in combating the clostridium difficile "hospital superbug".
He said: "The C difficile infection is a big problem. Like many hospitals we saw a big increase between 2005 and 2006, and this is proving much harder to control.
"It will be very challenging to reduce this, especially if targets are set."
The number of cases of C difficile – which causes sickness and diarrhoea and mainly affects vulnerable people over the age of 65 – rose from 250 in 2005 to 400 last year.
There are currently no Government targets for reducing this bug, with primary care trusts and health authorities due to decide their own targets later this year.
It is harder to contain as it is easier to spread than MRSA.
Dr Bentley said cases were increasing because of an ageing population and he added that patients could become vulnerable to the infection if they were on antibiotics.
alison.curtis@northantsnews.co.uk