February 22, 2011

Dutch researchers report new details of ESBL bacteria in chickens

Dutch researchers have stated new data on the connection of ESBL bacteria in chickens and humans afflicted with serious urinal or bloodstream infections.

According to the researchers, in one in five patients, these ESBL-bacteria are genetically identical to the antibiotic resistance bacteria that have been found in chicken.

Nearly all chicken in Dutch supermarkets and at poultry farms are infected with ESBL-bacteria. ESBL stands for Extended Spectrum Beta-Lactamase, which are enzymes that have developed a resistance to antibiotics like penicillin. ESBL enzymes are most commonly produced by two bacteria - Escherichia coli (E. coli) and Klebsiella pneumoniae. The scientists say that their findings not conclusively prove that chicken meat is the source of the infection, but it is a strong lead. Epidemical observations, however, show that in the past years antibiotic resistance in humans and in chicken increases proportionally.

Roel Coutinho, director of the Dutch National Institute for Public Health and the Environment (RIVM), says the connection now is well demonstrated. "Sufficient to an extent that I say: this is another example of such a strong indication and such a threat that the use of antibiotics in the poultry sector must be strongly reduced," he said.

In 2010 the previous Dutch Minister of Agriculture demanded that the use of antibiotics in animal husbandry should be reduced by 20% compared to 2009, but clear data on the use have never been demonstrated. Dutch government believes self-regulation by the sector is more effective than legislation, because the support would be greater. "Leave it up to us," the poultry sector said. On a voluntary basis it has started registering antibiotic use.

According to Belgium veterinarian Davy Persoons, over 58% of the bacterial isolates (from broiler farms in Belgium) were resistant against four or more antibiotics. In his work, the Belgian researcher showed that E. coli showed the most resistance against antibiotics on Belgium poultry farms. "Over 50% of the E. coli was resistant against five different antibiotics. Only 4.8% was sensitive against all 14 tested antibiotics" he concluded.