Physiological and potentially pathogenic microbial flora in stone curlew (Burhinus oedicnemus), southeastern Sicily

Abstract

European stone curlew (Burhinus oedicnemus) is a Palearctic species with high conservation interest. This species nests on the ground, in open canopies with sparse herbaceous vegetation, and is typically found next to areas of intense agro-pastoral activity, where it feeds on invertebrates present in ruminant droppings. This study aimed to investigate the enteric, ocular, and oral bacterial flora of stone curlew and determine the possible occurrence of pathogenic bacteria. Furthermore, the study aimed to determine how epidemiological factors shape the bacterial flora. Fecal samples, cloacal, conjunctival and oral swabs from 61individuals of B. oedicnemus were taken in three different agro-pastoral areas of the southeastern Sicily. The presence of commensal and potentially pathogenic bacteria in the samples was evaluated by standard methods. The bacteriological analysis revealed the presence of 215 Gram – and 92 Gram + strains belonging to 23 different genera (12 families). Potentially pathogenic species including Salmonella enterica, Shigella dysenteriae, Staphylococcus aureus, and Enterococcus spp. have been identified. To our knowledge, this is the first study to determine the presence of potentially pathogenic bacteria in stone curlew living in a semi-natural habitat. Some of the detected bacterial species are potentially pathogenic not only for wild species but also for domestic animals and humans. Altogether, our results suggest that stone curlew from agro-pastoral areas are being colonized with commensal or potentially pathogenic bacteria from agricultural or human sources; the prevalence of bacteria is probably influenced by environmental and alimentary factors. B. oedicnemus can, therefore, be considered a good indicator of environmental contamination by bacteria deriving from human activities, which are potentially threatening stone curlew and other wild birds species‎.