ANTIBIOTIC RESISTANCE AND EXTENDED SPECTRUM BETA-LACTAMASES (ESBLs) PRODUCTION IN ESCHERICHIA COLI STRAINS ISOLATED FROM INTRAHOSPITAL PATIENTS

The main objectives of this work were to determine the prevalence of ESBL-producing E. coli and to establish antimicrobial susceptibility pattern of ESBL-producing and non producing strains. The tests were carried out in the laboratory of military hospital, Military Medical Academy (MMA), Belgrade, Serbia, during the second half of 2017 (July-December). Four hundred and fifty-one E. coli strains isolated from various clinical specimens were tested. Detection of ESBLs isolates was carried out by the double-disc synergy test and confirmed by double-disc diffusion test. The overall incidence of ESBLs production among E. coli isolates was 34%. The highest frequency of ESBLs production was noted in blood isolates (82%), which was statistically significant (p < 0.05) compared to the other isolates. The highest susceptibility of E. coli strains was expressed to imipenem (100%) and to amikacin (88%), so these antibiotics can be considered antibiotics of choice in the treatment of infections caused by this bacterium. The isolates that produced ESBLs were significantly (p < 0.05) more resistant to the classes of antibiotics other than beta-lactams compared to the non-ESBL-producers. These results show very high frequency of ESBLs production in the tested isolates and suggest the urgent introduction of some measures in clinical practice, such as quicker and reliable diagnostic tools, new effective therapies and reasonable use of existing drugs.