Antimicrobial resistance of Escherichia coli isolates from
canine urinary tract infections |
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| Authors: | Shao-Kuang CHANG Dan-Yuan LO Hen-Wei WEI Hung-Chih KUO |
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| Institution: | 1)Graduate Institute of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC;2)Department of Veterinary Medicine, National Chiayi University, Chiayi, 600, Taiwan, ROC;3)Department of Animal Science and Technology, National Taiwan University, Taipei 106, Taiwan, ROC |
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| Abstract: | This study determined the
antimicrobial resistance profiles of Escherichia coli isolates from dogs
with a presumptive diagnosis of urinary tract infection (UTI). Urine samples from 201 dogs
with UTI diagnosed through clinical examination and urinalysis were processed for
isolation of Escherichia coli. Colonies from pure cultures were
identified by biochemical reactions (n=114) and were tested for susceptibility to 18
antimicrobials. The two most frequent antimicrobials showing resistance in Urinary
E. coli isolates were oxytetracycline and ampicillin. Among the
resistant isolates, 17 resistance patterns were observed, with 12 patterns involving
multidrug resistance (MDR). Of the 69 tetracycline-resistant E. coli
isolates, tet(B) was the predominant resistance determinant and was
detected in 50.9% of the isolates, whereas the remaining 25.5% isolates carried the
tet(A) determinant. Most ampicillin and/or amoxicillin-resistant
E. coli isolates carried blaTEM-1 genes.
Class 1 integrons were prevalent (28.9%) and contained previously described gene cassettes
that are implicated primarily in resistance to aminoglycosides and trimethoprim
(dfrA1, dfrA17-aadA5). Of the 44 quinolone-resistant
E. coli isolates, 38 were resistant to nalidixic acid, and 6 were
resistant to nalidixic acid, ciprofloxacin and enrofloxacin. Chromosomal point mutations
were found in the GyrA (Ser83Leu) and ParC (Ser80Ile) genes. Furthermore, the
aminoglycoside resistance gene aacC2, the chloramphenicol resistant gene
cmlA and the florfenicol resistant gene floR were also
identified. This study revealed an alarming rate of antimicrobial resistance among
E. coli isolates from dogs with UTIs. |
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| Keywords: | antimicrobial resistance class 1 integrons urinary Escherichia coli |
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