| Abstrakt: |
Eleven multiresistant Escherichia coli strains of animal and human origin were assayed for the presence of antimicrobial resistance genes, integrons and associated gene cassettes, as well as plasmid content. Ciprofloxacin-resistant strains were screened for amino acid changes in GyrA and ParC proteins. The E. coli strains were found to harbor a variety of genes including cmlA, aac (3)-II, aac (3)-IV, aadA, strA-strB, tet (A), tet (B), bla(TEM), sul1, sul2 and sul3. Four of the eight int I1-positive strains were also positive for qacE Δ1 -sul1 region and the following gene cassettes were detected: dfrA7, dfrA12 + orfF + aadA2 and bla(OXA1)+ aadA1. Five strains contained class 1 integrons lacking the qacE Δ1 -sul1 region and they showed a single type of gene cassette arrangement (estX + psp + aadA2 + cmlA + aadA1 + qacH + IS440 + sul3). The two int I2-positive strains carried the same type of gene cassette arrangement (dfrA1 + sat + aadA1). The seven ciprofloxacin-resistant E. coli strains exhibited a Ser-83-Leu substitution in GyrA protein and a Ser-80-Ile substitution in ParC protein; six of these strains presented an additional substitution in GyrA (Asp-87-Gly or Asp-87-Asn) and one strain in ParC (Glu-84-Gly). Eight different plasmid-replicon-types were detected among the 11 E. coli strains, IncF being the most frequent one detected, found in nine strains; other plasmid replicon types detected were IncX, IncI1, IncY, IncW, IncFIC, IncB/O, and IncK. Antimicrobial resistance in the E. coli strains studied was mediated by a variety of genes, some of them included in integrons, as well as by mutations gyr A and par C genes. |
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