Prevalence and molecular characterization of Clostridium difficile isolated from European Barn Swallows (Hirundo rustica) during migration

Abstract

BackgroundClostridium difficile is an important bacterial pathogen of humans and a variety of animal species. Birds, especially migratory passerine species, can play a role in the spread of many pathogens, including Clostridium difficile. Barn Swallows (Hirundo rustica) nest in close proximity to human habitats and their biology is closely associated with cattle farming. Therefore, we hypothesized that Barn Swallows can be the reservoir of Clostridium difficile.ResultsBarn Swallows (n = 175) were captured on their autumn migration across Europe to sub-Saharan Africa. Droppings were collected from juvenile (n = 152) and adult birds (n = 23). Overall prevalence of Clostridium difficile was 4% (7/175); 4.6% (7/152) in juvenile birds and 0/23 in adults. Clostridium difficile ribotypes 078, 002 and 014 were identified, which are commonly found in farm animals and humans. Three new Clostridium difficile ribotypes were also identified: SB3, SB159 and SB166, one of which was toxigenic, harbouring genes for toxins A and B.ConclusionsResults of this study indicate that Barn Swallows might play a role in national and international dissemination of Clostridium difficile and could serve as a source for human and animal infection. Clostridium difficile ribotype 078 was identified, which has been reported as an emerging cause of community-associated Clostridium difficile infection in humans. Based on this and other studies, however, it is more likely that Barn Swallows have a more indicative than perpetuating role in Clostridium difficile epidemiology.

Presence ofClostridium difficilein pig faecal samples and wild animal species associated with pig farms

“…These results were in line with those from a previous study that found C. difficile in faeces from wild birds (house sparrows) trapped in or close to pig farms (Burt et al 2012). Interestingly, other bird species have also found positive for ribotypes which are commonly found in farm animals and humans (Bandelj et al 2014).…”

“…As observed in other infections such as salmonellosis (Andr es et al 2013), wild birds in close contact with pig farms may be at higher risk of harbouring the pathogens present in the farm, especially if the farm environment appears to be highly contaminated. These results differed from those from other European countries, including Spain, in which C. difficile was not found in wild birds or was isolated from only a few samples (Alderete 2011;Bandelj et al 2011Bandelj et al , 2014. However, in these studies, most of the sampled birds were not related to pig farming.…”

“…Interestingly, other bird species have also found positive for ribotypes which are commonly found in farm animals and humans (Bandelj et al . ). As observed in other infections such as salmonellosis (Andrés et al .…”

“…These results differed from those from other European countries, including Spain, in which C. difficile was not found in wild birds or was isolated from only a few samples (Alderete ; Bandelj et al . , ). However, in these studies, most of the sampled birds were not related to pig farming.…”

Clostridium difficile in Food and Animals: A Comprehensive Review

“…Furthermore, different studies have investigated the presence of the bacterium in wild animals, including wild passerine birds (Bandelj et al 2011) and barn swallows (Bandelj et al 2014); zoo animals (chimpanzees, dwarf goats, Iberian ibexes and plains zebras) (Á lvarez-Pérez et al 2014); sea otters (Miller et al 2010); free-living South America coatis (Silva et al 2014); small and medium-size wild mammals (raccoons, shrews, deer and house mice, rats, voles, opossum and groundhogs) (Jardine et al 2013); black and Norway rats (Firth et al 2014;Himsworth et al 2014); feral pigs (Thakur et al 2011) and Iberian free-range pigs (Á lvarez-Pérez et al 2013).…”