UP TO half of the 55,000 people taking antibiotics every day in Scotland would get better without them, according to ministers.

The claim came as national guidelines are to be introduced for treating common infections with one leading expert suggesting that the nation is making "substantial progress" in tackling the problem of resistance to the medications.

Professor Dilip Nathwani, chairman of the Scottish Antimicrobial Prescribing Group, said measures to slow down resistance were having an effect but more must be done to cut unnecessary prescribing of the drugs.

Growing numbers of bacterial and viral infections are resistant to antibiotics and the problem was described by the World Health Organisation (WHO) earlier this year as "a global threat".

Mr Nathwani said: "In the last six years we have made substantial progress in improving the quality of prescribing: more patients are getting the right treatment for the right infection. Combined with good infection control, this has led to a significant reduction in C.difficile (C. diff) infections and the slowing-down of antimicrobial resistance, which is regarded by the WHO as a serious global threat to human health."

Cases of C. diff in patients aged over 65 have reduced by 84% during the last seven years, from 1775 cases between January and March 2007 to 270 cases in the same period this year, the lowest since mandatory surveillance began.

Mr Nathwani said: "We have much more to do to reduce the total amount of unnecessary antibiotic prescribing and also ensure we measure the impact of our interventions on health outcomes.

"The work undertaken so far at local and national level has led to Scotland being recognised worldwide as having an exemplar antimicrobial stewardship programme."

He welcomed the action plan, saying it would build on the progress made so far.

The document includes a commitment to issue national guidance on treating common infections.

Education initiatives will also be developed to raise awareness about the problem among health workers and the public.

Health Secretary Alex Neil said: "In Scotland we are leading the way in tackling the growing threat of antimicrobial resistance and our investment over the last six years in antimicrobial work is already delivering positive changes.

"This report shows that we are ahead of the game and have already adopted many of the recommended measures - including better prescribing and improved infection control.

"However, the situation is constantly moving and this ­four-year action plan sets out how we will, as a country, collectively play our part in ensuring all measures are taken to reduce resistance to antibiotics.

"It is vital that we act to protect both ourselves and future generations from the serious ramifications of antibiotic resistance."

Prime Minister David Cameron recently warned the world could be "cast back into the dark ages of medicine" unless action is taken to tackle antibiotic resistance.

He announced an independent review - led by an economist and to include experts from science, finance, industry, and global health - to look at the economic issues associated with the problem, including why no new classes of antibiotics have come on the market for more than 25 years.

It will set out plans for encouraging the development of new antibiotics.