Enteric bacteria in Olrog's Gull and Kelp Gull from the Estuary of Bahía Blanca, Argentina

LA SALA L.F.; PETRACCI P.; RANDAZZO, V.; MIYAKAWA, M.E.

El Hornero

Asociación Ornitológica del Plata

Lugar: Buenos Aires; Año: 2014 vol. 28 p. 59 - 64

0073-3407

The Estuary of Bahía Blanca in Argentina is under the effect of chronic microbiological pollution with untreated municipal raw sewage and the pathogens associated with it. In this estuary, there are breeding colonies of Olrog´s Gull (Larus atlanticus) and Kelp Gull (Larus dominicanus), where parents feed chicks and themselves on prey and food items foraged at or near sewage outfalls and refuse tips where they can be exposed to pathogens of human and animal origin. The objective of this study was to assess the role of Olrog´s Gull and Kelp Gull as carriers of zoonotic pathogens of fecal origin. The presence of fecal bacteria was assessed using standard bacteriological methods. Bacterial recovery from fecal samples of both species was positive for Salmonella typhimurium, Salmonella gallinarum, Escherichia coli, Shigella dysenteriae, Enterobacter cloacae, and Klebsiella pneumoniae. The prevalence and diversity of pathogens found varied between gull species and age categories, and Olrog´s Gull tested positive for a wider range of pathogens than Kelp Gull. Escherichia coli was the most prevalent bacteria in chicks and adults of both gull species, followed by Salmonella spp. in Olrog´s Gull chicks, and Enterobacter cloacae and Shigella dysenteriae in Olrog´s Gull adults. This is the first report of enteric pathogens in Olrog´s Gull and provides evidence that these and Kelp Gull act as carriers of human-specific and zoonotic pathogens in the study area.