Pathogenic microorganisms carried by migratory birds passing through the territory of the island of Ustica, Sicily (Italy)

Abstract

Several studies have shown that migratory birds play an important role in the ecology, circulation and dissemination of pathogenic organisms. In October 2006, a health status evaluation was performed on a large population of migratory birds passing through the territory of Ustica (Italy), an island located on the migration route of many species of birds to Africa, and various laboratory tests were conducted. In total, 218 faecal swabs and the internal organs of 21 subjects found dead in nets were collected for bacteriological and virological examination, including avian influenza and Newcastle disease. In addition, 19 pooled fresh faecal samples were collected for mycological examination. The bacteriological analysis produced 183 strains belonging to 28 different species of the Enterobacteriaceae family. In particular, Salmonella bongori, Yersinia enterocolitica and Klebsiella pneumonia strains were isolated. Almost all of the isolates were susceptible to sulphamethoxazole/trimethoprime (99.4%), cefotaxime (98.9%), nalidixic acid (96.7%), chloramphenicol (95.6%), and tetracycline (93.4%). Alternatively, many strains were resistant to ampicillin (42.6%), amoxicillin-clavulanic acid (42.6%), and streptomycin (43.7%). According to reverse transcriptase-polymerase chain reaction analysis, all of the samples were negative for the M gene of avian influenza virus. Moreover, isolation tests conducted on specific pathogen free eggs were negative for avian influenza and Newcastle disease. Several hyphomycetes and yeasts belonging to different genera were present in the specimens, and Cryptococcus neoformans was observed in a pooled faecal sample. Antibiotic resistance in wildlife can be monitored to evaluate the impact of anthropic pressure. Furthermore, migratory birds are potential reservoirs of pathogenic agents; thus, they can be regarded as sentinel species and used as environmental health indicators.

Epidemiological Importance of Yeasts Isolated from the Beak and Cloaca of Healthy Charadriiformes

“…Interestingly, mycoses are sporadic in wild birds that are not fed by humans (23), while carrier-state, especially in water fowl, is reported more frequently than in other vertebrates (8,25). Fungi can be transmitted by birds in a passive manner (on the body surface or in feathering), by biological vectors (ectoparasites), or in the internal organs, mainly in the respiratory and digestive tracts, as evidenced by the close correspondence of the obtained results with the observations of other authors (17,18,25).…”

“…However, C. neoformans is a fungus that is thought to be the most dangerous to humans, especially to children. It is believed to be the most common commensal of birds (13,17,18,22) in which it asymptomatically colonises the skin, subcutaneous tissue, and lungs. This fungus is common in the lithosphere and easily develops in the Polish climate (particularly in autumn) on the faeces of different avian species and in faeces-contaminated soil (13).…”

Influenza monitoring in Sardinia, Italy identifies H3 subtype in Mediterranean wild migratory birds

“…Furthermore, it is commonly thought that early detection of avian influenza is essential for economic security in the poultry industry and maintenance of public health [32]. Previously, avian influenza has been monitored in wild birds, including those in Italy and those crossing the Europe/North America land bridge [11,[33][34][35][36][37]. We investigated for the first time the influenza strains currently affecting the migratory birds landing in the island of Sardinia, a land bridge between Europe and Africa.…”

“…LPAI viruses infect the intestinal tract of avian species typically through the fecal-oral route, whereas the HPAI viruses with mutated polybasic amino acids in the HA cleavage site can infect a range of tissues and organs outside of the gut [8,9]. Studies have implicated migratory birds in the spread of pathogenic organisms including the influenza virus, although controversy exists surrounding the ability of migratory birds to disseminate HPAI strains and the clinical disease caused by infection [7,8,[10][11][12][13][14][15][16][17].…”

Antibiotic resistance assessment in bacteria isolated in migratory Passeriformes transiting through the Metaponto territory (Basilicata, Italy)

“…Several studies have shown that migratory wild birds play an important role in the ecology, circulation and dissemination of enteric human pathogens such as Campylobacter, Salmonella, toxin-producing Escherichia coli and antimicrobial resistant organisms (Reed et al 2003;Abulreesh et al 2007;Foti et al 2011;Magda et al 2013).…”