Acta Vet. Brno 2018, 87: 9-17

Prevalence and molecular characteristics of multi-resistant Escherichia coli in wild birds

Lina Merkeviciene, Irena Klimiene, Rita Siugzdiniene, Marius Virgailis, Raimundas Mockeliunas, Modestas Ruzauskas

Lithuanian University of Health Sciences, Microbiology and Virology Institute, Kaunas, Lithuania

Received June 1, 2017
Accepted April 3, 2018

Humans and animals share the same bacterial species including the resistant ones. For that reason, epidemiological studies in domestic and wild animals should be performed on a regular basis. Wild, particularly migratory birds, should be investigated as potential carriers of antimicrobial resistant bacteria that can be spread globally in a short time. The aim of this study was to investigate the prevalence and to characterize multi-resistant Escherichia coli in wild birds. Three hundred and ninety two samples were obtained from different bird species including gulls (Larus spp.), mallards (Anas platyrhynchos), mute swans (Cygnus olor), as well as other species of birds. Phenotypical and genotypical resistance of E. coli was investigated. In total 60 isolates from 179 tested were resistant to three or more antimicrobial classes and treated as multi-resistant (33.5%; 95% CI 21.56–45.44); the isolates were obtained from gulls, mallards, swans, and rooks. All of the strains demonstrated resistance to aztreonam and cefpodoxime. The most frequent resistance prevalence of the above-mentioned isolates in vitro was also demonstrated to ampicillin (82%), ampicillin/sulbactam (68%), cefazolin (66%), ceftriaxone (55%), and ciprofloxacin (47%). All E. coli isolates were susceptible to amikacin. The results of polymerase chain reaction confirmed the presence of the genes encoding resistance to beta-lactams, aminoglycosides, tetracycline, amphenicols, trimethoprim, and sulphonamides. Consequently, wild birds might constitute a potential hazard to human and animal health by transmitting multi-resistant E. coli strains to waterways and other environmental sources via bird faeces.


The study was funded by a grant (SIT-6/2015) from the Research Council of Lithuania.


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