Thebeta-lactamases with extended spectrum of activity (ESBL) are medically one ofthe most important group of enzymes. The presented study providesidentification and determination of the spectrum of resistance againstdifferent and clinically used antimicrobial drugs in the clinical isolates of Escherichiacoli. These isolates had their origin in different departments of theUniversity Hospital L. Pasteur in Košice. The second goal was the detection ofbeta-lactamase production with extended-spectrum effect (ESBL) and testing ofAmpC-type cephalosporinases by several phenotypic tests in clinical isolates.We used both the microdilution method and the method with an active agent,respectively. Samples were positively tested for ESBL with the use of the CLSIdisk diffusion method. PCRs were performed with a series of primers designedfor the detection of Ambler class A, B and C beta-lactamase genes. About 307strains of E. coli were investigated. The growth of E. coliresistance to selected antibiotics was present in 83.25% of clinical isolates.There were identified 85 positive isolates in the studied group and the prevalence of the ESBL positive strains ofE. coli reached 27.78%. An E. coli strain was isolated withmutations in the promoter region of the AmpC chromosomal gene that isassociated with overproduction of the relevant enzyme. We describe a complexESBL epidemiology. The study revealed a high rate of ESBL-producing E. coliisolates. The blaTEM and blaSHV enzymesdominated in ESBL-positive E. coli isolates in the University HospitalL. Pasteur in Košice.
