Abstract
Antimicrobial resistance profiles were assessed in
Enterococcus faecium, Enterococcus faecalis,
and
Enterococcus columbae
strains isolated from racing pigeons (
Columba livia
).
E.
columbae
is the most prevalent enterococcal species in the intestines of pigeons. Acquired resistance against the antimicrobials bambermycin, vancomycin, monensin, narasin, virginiamycin (cross-resistant
with quinupristin/dalfopristin), avilamycin (cross-resistant with evernimicin), and ampicillin was not seen. Only for the antimicrobials tetracycline and tylosin was a frequent occurrence of resistance
found in all three enterococcal species tested. Resistance to the fluoroquinolone antimicrobial enrofloxacin was present in
E. columbae.
Bacitracin resistance was seen in the species
E. faecalis
and
E. faecium
but not in
E. columbae.
High-level streptomycin resistance was found in
E. columbae
and in one
E. faecium
strain, whereas high-level gentamicin resistance was
mainly associated with
E. faecalis.
The differences noted between the different species illustrate the difficulties related to the choice of indicator bacteria for antimicrobial resistance in the
intestinal flora.