Health Secretary Nicola Sturgeon has ruled out an immediate public inquiry into the issue of Clostridium difficile in Scottish hospitals.
Her comments came during question time at Holyrood after Labour and the Tories said enough was not being done.
The exchanges followed a BBC probe into the death of 18 patients at the Vale of Leven Hospital, Dunbartonshire.
Ms Sturgeon said tackling infection was a top priority, adding: "It is a responsibility I will never shirk."
A total of 55 people were affected by the Clostridium difficile bug at the Vale of Leven Hospital between December of last year and June this year.
C.diff was the primary cause of the death of nine patients and was a contributory factor in another nine deaths.
Scottish Labour leader Iain Gray urged Ms Sturgeon to hold an immediate public inquiry, adding: "In opposition, the health secretary called for public inquiries with monotonous regularity - but in government she resists doggedly.
"What is she afraid of? What is she trying to cover up?"
Mr Gray demanded: "She is the only obstacle to the inquiry we need - in the interests of the families, will she change her mind now?"
Ms Sturgeon said an ongoing police investigation into the events at the Vale of Leven meant it was not appropriate to stage an immediate public inquiry - but has not ruled one out altogether.
"I readily recognise that C.diff is a growing concern - it's not a new concern," she said, while standing in for First Minister Alex Salmond.
"The death rates from Clostridium difficile in Scotland have been rising steadily throughout this entire decade. It's an issue that is a problem and an issue that we are determined to tackle."
The Vale of Leven Hospital was the focus of the C.diff outbreak
The health secretary said funding to tackle hospital infections had been tripled, while cleaning standards had been toughened up and infection-cutting targets had been set.
Scottish Conservative leader Annabel Goldie said Scotland was "behind the game" on tackling hospital-acquired infection, saying Ms Sturgeon needed a "reality check".
"We need to know what is happening, where it is happening, why it is happening and when it is happening," added Ms Goldie.
Ms Sturgeon said Scotland had been playing "catch up" with England since she took office, because the last Labour/Lib Dem Scottish Government only introduced mandatory surveillance three years after south of the border.