Abstract
BackgroundThe incidence of human infection and colonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) has increased in the recent years. Environmental sources, including bird droppings, might play an important role as resistance reservoirs.ResultsFresh fecal samples were collected from rooks and wild-living birds during the autumn-winter period of 2016/2017, and tested for the presence of bacteria associated with human diseases. Besides bacteria representing the genera Enterococcus, Campylobacter, Escherichia, and Staphylococcus, Enterobacter, Citrobacter, Proteus, Hafnia, and Pseudomonas were also identified. The susceptibility of S. aureus and Enterococcus spp. isolates to methicillin, and vancomycin and teicoplanin, respectively, was analyzed to assess the avian wildlife as a reservoir of MRSA and VRE strains. Twenty-two percent of all S. aureus isolates were methicillin-resistant. These strains were screened by polymerase chain reaction (PCR), using the most widely used primer sets specific for the mecA gene. Twenty percent of all Enterococcus strains were phenotypically vancomycin-resistant. The presence of van resistance genes in these strains was investigated by PCR using vanA and vanB gene-specific primers. A good correlation between mecA gene detection and disc diffusion data was observed, while some discrepancy was noted between the PCR data and the vancomycin/teicoplanin phenotypic resistance pattern. The incidence of strains resistant to methicillin and glycopeptide antibiotics in wild-living birds was twice that in rooks.ConclusionsThe study suggests that rooks from urban areas and passerine birds from the natural habitat carry antibiotic-resistant Enterococcus spp. and S. aureus strains, probably reflecting the presence of such isolates in the environmental food sources.
Highlights
The incidence of human infection and colonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) has increased in the recent years
Wild-bird populations attracted to urbanized areas can be colonized with strains of Enterococcus spp. [6], Escherichia coli, Salmonella spp. [7,8,9], and Staphylococcus that are all resistant to antibiotics [4, 5, 10]
The aim of the current study was to evaluate and compare the presence of potentially pathogenic bacteria in the feces of rooks feeding in public sites and wild birds inhabiting places far from the urban areas, to verify whether feeding municipal food waste increases the occurrence of bacteria that could be harmful to human health
Summary
The incidence of human infection and colonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) has increased in the recent years. Environmental sources, including bird droppings, might play an important role as resistance reservoirs. Wild-living birds are reservoirs of potentially pathogenic bacteria. They may play an important role in the epidemiology of human diseases, either directly or indirectly, by contaminating foodstuff, water, dust, or other environmental sources [1]. Free-living bird species that are frequently found in the human environment are naturally infected with viruses, bacteria, fungi, and protozoa that are pathogenic to human [3,4,5]. Wild-bird populations attracted to urbanized areas can be colonized with strains of Enterococcus spp. Enterococcus, Campylobacter, E. coli, and coliforms are the predominating bacteria in feces of wild-living birds [2].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
