Free-living Waterfowl as a Source of Zoonotic Bacteria in a Dense Wild Bird Population Area in Northeastern Spain

Salmonella spp. and Campylobacter spp. are zoonotic bacteria that represent an economic and public health concern worldwide. Due to the difficulty to collect samples from free-living waterfowl, little is known on their importance as a reservoir of zoonotic agents. Thus, a study was conducted to determine the prevalence, genotypic diversity and antimicrobial susceptibility of Salmonella and Campylobacter from waterfowl in Ebro Delta (northeastern Spain), a geographical area with a dense wild bird population. Samples were collected from 318 adult waterfowl belonging to nine fowl species. All the samples were taken during the hunting season from 2008 to 2010. None of the birds were positive for Salmonella, while the overall Campylobacter prevalence was 12.58% (40/318). A much higher Campylobacter coli prevalence than Campylobacter jejuni was found (11.64% versus 0.94%). The species Fulica atra showed the highest Campylobacter prevalence (78.05%). ERIC-PCR of the isolates showed a high diversity of strains. Antimicrobial susceptibility testing of Campylobacter isolates showed that all the isolates were susceptible to the seven antibiotics tested.