Role of wild birds as carriers of multi-drug resistant Escherichia coli and Escherichia vulneris

Braz J Microbiol. 2015 Mar 4;45(4):1199-209. doi: 10.1590/s1517-83822014000400010. eCollection 2014.


Emergence and distribution of multi-drug resistant (MDR) bacteria in environments pose a risk to human and animal health. A total of 82 isolates of Escherichia spp. were recovered from cloacal swabs of migrating and non-migrating wild birds. All bacterial isolates were identified and characterized morphologically and biochemically. 72% and 50% of isolates recovered from non-migrating and migrating birds, respectively, showed positive congo red dye binding (a virulence factor). Also, hemolysin production (a virulence factor) was showed in 8% of isolates recovered from non-migrating birds and 75% of isolates recovered from migrating birds. All isolates recovered from non-migrating birds were found resistant to Oxacillin while all isolates recovered from migrating birds demonstrated resistance to Oxacillin, Chloramphenicol, Oxytetracycline and Lincomycin. Some bacterial isolates recovered from non-migrating birds and migrating birds exhibited MDR phenotype. The MDR isolates were further characterized by API 20E and 16S rRNA as E. coli and E. vulneris. MDR Escherichia isolates contain ~1-5 plasmids of high-molecular weights. Accordingly, wild birds could create a potential threat to human and animal health by transmitting MDR bacteria to water streams and other environmental sources through their faecal residues, and to remote regions by migration.

Keywords: 16S rRNA; API 20E; E. coli; E. vulneris; congo red binding; hemolysin; migrating and non-migrating birds; multi-drug resistance (MDR); plasmid profile.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Typing Techniques
  • Birds
  • Carrier State / microbiology
  • Carrier State / veterinary*
  • Cloaca / microbiology
  • Cluster Analysis
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • DNA, Ribosomal / chemistry
  • DNA, Ribosomal / genetics
  • Drug Resistance, Multiple, Bacterial*
  • Enterobacteriaceae Infections / microbiology
  • Enterobacteriaceae Infections / veterinary*
  • Escherichia / classification
  • Escherichia / drug effects*
  • Escherichia / isolation & purification*
  • Molecular Sequence Data
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA
  • Virulence Factors / analysis


  • Anti-Bacterial Agents
  • DNA, Bacterial
  • DNA, Ribosomal
  • RNA, Ribosomal, 16S
  • Virulence Factors

Associated data

  • GENBANK/AB758349
  • GENBANK/AB758350
  • GENBANK/AB758351
  • GENBANK/AB758352
  • GENBANK/AB758353
  • GENBANK/AB758354
  • GENBANK/AB758355
  • GENBANK/AB758356
  • GENBANK/AB758357