Zero prevalence of Clostridium difficile in wild passerine birds in Europe

Abstract

Clostridium difficile is an important bacterial pathogen of humans and a variety of animal species, where it can cause significant medical problems. The major public health concern is the possibility of inapparent animal reservoirs of C. difficile and shedding of bacteria to noninfected individuals or populations, as well as being a source of food contamination. Migrating birds can be a key epizootiological factor for transmission and distribution of pathogens over a wide geographic range. Therefore, the purpose of this study was to investigate whether migrating passerine birds can be a source of spread of C. difficile along their migration routes. Cloacal samples were taken from 465 passerine birds during their migration south over the Alps. Selective enrichment was used for detection of C. difficile. Clostridium difficile was not isolated from any of the samples, which indicates that migrating passerine birds are unlikely to serve as a reservoir and a carrier of C. difficile.

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

“…The sample population in this study was predominantly juvenile birds, which is in concordance with the expected ratio of juvenile birds on migration (>80%) [16,30]. In most studied animal species, CD tends to predominate in younger animals [31,32].…”

“…Passerine birds were previously not determined to be the source of CD; however, only passerines unlikely to come in close contact with humans have been investigated [16]. In contrary, House Sparrows, a non-migrating passerine, had previously been associated with CD on pig farms in the Netherlands [19].…”

“…An epidemiological study on mostly migrating passerine birds in Europe suggested that they are unlikely to serve as a carrier or reservoir of CD [16]. However, the study [16] was conducted in the region where Barn Swallows ( Hirundo rustica ) were not congregating during their migration south, and included only garden birds unlikely to dwell in habitats intensively cultivated by humans.…”

“…However, the study [16] was conducted in the region where Barn Swallows ( Hirundo rustica ) were not congregating during their migration south, and included only garden birds unlikely to dwell in habitats intensively cultivated by humans. On the other hand, Barn Swallows, come in close contact with human habitats [17,18], as do House Sparrows ( Passer domesticus ), which are a non-migrating passerine bird, that have been associated with CD when sampled on pig farms [19].…”

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).…”