Characterization of a 2.6 kbp variable region within a class 1 integron found in an Acinetobacter baumannii strain isolated from a horse.
OBJECTIVE
A complete gene cassette contained in a class 1 integron from a multidrug-resistant (MDR) isolate of Acinetobacter baumannii cultured from a horse was characterized by molecular methods.


METHODS
Template genomic DNA purified from the A. baumannii isolate was investigated by PCR. A gene cassette-associated amplicon was detected and completely characterized.


RESULTS
A 2.6 kbp DNA fragment containing four gene cassettes was amplified from the MDR A. baumannii isolate. Sequence analysis showed it was similar to sequences recently reported in Klebsiella pneumoniae, Serratia marcescens and an Escherichia coli plasmid p1658/97 which conferred aminoglycoside resistance. Aminoglycoside resistance-encoding genes aacC1 and aadA1 were located within the 2.6 kbp amplicon, separated by two open reading frames (ORFs) coding for unknown products. This cassette structure (and some variants) was identified in unrelated Acinetobacter spp. from human sources, based on sequence comparisons of the current databases.


CONCLUSIONS
Identification of a complete class 1 integron in an equine isolate of A. baumannii suggests that the screening of isolates from animals for these elements should be considered, as this information could influence the selection of chemotherapeutic agents.
Abbott
Yvonne
Y
Department of Veterinary Microbiology & Parasitology, Faculty of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
O'Mahony
Rebecca
R
Leonard
Nola
N
Quinn
P Joseph
PJ
van der Reijden
Tanny
T
Dijkshoorn
Lenie
L
Fanning
Séamus
S
D040981:Acinetobacter baumannii / Q000187:drug effects / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D006736:Horses / Q000382:microbiology*; D032023:Integrons; D008969:Molecular Sequence Data