Scientists in Portugal have discovered that a species of seagull that feeds on human rubbish is carrying and spreading highly drug-resistant superbug bacteria.
You can read how lead researcher Dr Gilberto Igrejas, from the University of Tras-os-Montes and Alto Douro, and colleagues, make their discovery in the 21 September issue of the journal Proteome Science.
In their background information, Igrejas and colleagues explained that Enterococci bacteria are now the third most common cause of infections in hospital settings, requiring antibiotic therapy.
A growing problem in such settings is resistance to the “last resort” antibiotic vancomycin which is normally only used when other drugs have failed, and while studies have shown that resistance is emerging in farm animals, few have looked at the extent of the problem in wild animals, said the researchers.
To investigate the problem they decided to look at a particular population of wild animals: a type of Herring Gull known as the Larus Cachinnans seagull.
These large, loud, white and grey seagulls with distinctive yellow legs are often seen scavanging around rubbish tips in the south of the UK.
For the study, the researchers collected and analysed 57 samples of feces dropped by Larus Cachinnans seagulls on an island off the Portuguese coast that is part of the Berlengas Nature Reserve.
They found that one in ten of the samples carried bacteria that showed signs of having developed resistance to vancomycin. They also found signs of resistance to other antibiotics.
The researchers used a method based on “proteomics” and “genomics” to create a comprehensive inventory of particular proteins, the presence of which indicates that bacteria have developed resistance to drugs (for instance in the case of vancomycin, the protein is vanA).
According to a Press Association report, Igrejas told the media that:
“Migrating birds that fly and travel long distances can act as transporters, or as reservoirs, of antibiotic-resistant bacteria and may consequently have a significant epidemiological role in the dissemination of resistance.”
“Our comprehensive description of the proteins that we found may provide new targets for development of antimicrobial agents,” he added.
The researchers suggested that their findings may also help to find new biomarkers of antibiotic resistance and also virulence in infectious bacteria.
“Proteomic characterization of vanA-containing Enterococcus recovered from seagulls at the Berlengas Nature Reserve, W Portugal.”
Hajer Radhouani, Patricia Poeta, Luis Pinto, Julio Miranda, Celine Coelho, Carlos Carvalho, Jorge Rodrigues, Maria Lopez, Carmen Torres, Rui Vitorino, Pedro Domingues, Gilberto Igrejas.
Proteome Science, 2010, 8:48 (21 September 2010).
DOI: 10.1186/1477-5956-8-48
Additional source: Press Association.
Written by: Catharine Paddock, PhD