Prevalence of Listeria monocytogenes and other Listeria spp. in gulls feeding on Zagreb landfill site, Croatia

Gulls, as migratory wild birds are known that can spread different pathogens over long distances. Aim of this study was to access prevalence of different Listeria species in their population fed at the Zagreb landfill site. Altogether, 390 gulls of three species were sampled: Yellow-legged Gull, Larus michahellis; Black-headed Gull, L. ridibundus and Common Gull, L. canus. Most prevalent species was L. innocua (14.4%), while L. monocytogenes was found in 11.3 % of tested samples. The presence of other species was found in a smaller percentage, namely L. welshimeri (1.3%), L. ivanovii (0.5%) and L. seeligeri (0.3%). Serotyping of L. monocytogenes isolates was performed using both molecular and conventional methods, and most isolates belonged to serotypes 1/2a and 1/2b. To the best of our knowledge, this study reports the first results of research on the presence of L. monocytogenes and other Listeria spp. in wild birds in Croatia.