Characterisation of ESBL phenotypes
The strains were phenotypically screened by E-test
MIC using ceftazidime, π/ª clavulanic acid, cefotaxime
π/ª clavulanic acid and cefepime π/ª clavulanic
acid (AB Biodisk, Solna, Sweden). A reduction of
MIC by 3 twofold dilutions of the cephalosporin in
the presence of clavulanic acid, i. e. a MIC ratio of 8,
was considered indicative of ESBL phenotype.