The findings, published in the Danish integrated antimicrobial resistance monitoring and research programme’s (DANMAP) annual report, also revealed that the levels of the bacteria found in imported broiler meat remained the same as in 2012, at just over half. The report is published by Statens Serum Institut and the National Food Institute, Technical University of Denmark.
ESBL (extended-spectrum beta-lactamase) bacteria, such as E.coli, salmonella and klebsiella, are enzymes which cause cephalosporin resistance. Cephalosporins are antimicrobials used for the treatment of life-threatening infections in humans.
According to the National Food Institute (NFI), Danish poultry producers have not used cephalosporins for more than a decade.
Yvonne Agersø, senior researcher, at the NFI, said: "When resistant ESBL bacteria are nonetheless found in Danish broiler meat, it is because they have entered production through imported parent animals of the chickens we eat today. ESBL bacteria are inherited from generation to generation, and until 2012 cephalosporins were used in animals at the top of the breeding pyramid abroad.
"The situation shows why it is necessary to have international standards for the use of antimicrobials in food production in order to avoid resistance problems in one country creating problems beyond its borders," she added.
There was a much lower incidence of ESBL bacteria being found in pigs (5.8%), than in poultry, at slaughter last year, due to the decision by Danish pork producers to introduce a voluntary ban on cephalosporins in 2010. However, the figure was higher than the previous year.
Of a total antimicrobial consumption in pigs of just over 90 tonnes, approximately three kilos was cephalosporins. However, while antimicrobial usage in animals increased in pigs by 6% last year, it is still 12% lower than in 2009.
"Even though the use of cephalosporins is very low, it still represents a considerable increase compared to the previous year when it was one kilo. It is important that these antimicrobials are only used when absolutely necessary, so we can maintain the low occurrence of ESBL that we have seen in pigs at slaughter in recent years," continued Agersø.
From 2015, all EU member states will be required to monitor the occurrence of resistance in cattle and pigs as well as beef and pork – and from 2016 it will be required for broilers and broiler meat.