September 21, 2010

Antibiotic-Resistant Bacteria Found In Seagulls

A new study, published Tuesday in the open access journal Proteome Science, has found the presence of antibiotic-resistant enterococci bacteria in seagull stool, leading researchers to believe that the birds could be spreading difficult-to-treat infections.

The team of researchers, which included Gilberto Igrejas from the University of Trás-os-Montes and Alto Douro in Portugal, studied the droppings of the Larus cachinnans species of gulls. They found that one out of every ten carry bacteria that is resistant to the glycopeptide antibiotic vancomycin. The samples were obtained from the Berlengas Natural Reserve of Portugal.

In a Monday statement, Igrejas said that he and his colleagues "used a novel technique called proteomics to detect the maximum number of bacterial proteins which are thought to be connected in some, as yet unknown, way to antibiotic resistance. Our comprehensive description of the proteins that we found may provide new targets for development of antimicrobial agents. This knowledge may also help to identify new biomarkers of antibiotic resistance and virulence factors."

According to BBC News Health Reporter Michelle Roberts, the researchers "identified several strains of enterococcus bacteria in the samples--some of which were resistant to vancomycin."

Specifically, of the 57 fecal samples collected by the research team, 54 of them contained some form of Enterococcus. Half of the seagull samples contained E. faecium, while just over 10-percent of them contained E. faecalis and E. durans, and roughly 6-percent of them contained E. hirae. Not all of those are considered resistant to vancomycin, however--only 10.5-percent of the samples contained strains that met that criteria.

"Given that these are wild birds and not pets, they will not have encountered these antibiotics directly," Roberts said. "Instead, their exposure has come inadvertently from humans"¦ And the scientists believe wild migratory birds may be spreading antibiotic resistance from place to place, and to other animals and humans through their droppings."

"Antibiotic-resistant bacteria are generally harmless to healthy people but can cause serious infections in the weak and vulnerable," she added. "There are usually other antibiotics that can be used to treat the infection"¦ The concern is that they could pass on their resistance to bacteria that can evade other antibiotics, ultimately leading to infections that would be incredibly difficult to treat."


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