[Comparison of agar screening plates and double disk synergy method in detection of extended-spectrum beta-lactamase...

In this study, extended-spectrum beta-lactamase (ESBL) production of 83 enteric isolates has been investigated by using a new agar screening method described by Storenburg et al. and double disk synergy (DDS) method. Agar screening method has also been evaluated in terms of presumptive bacterial identification. ESBL production was shown in 15 (18.1%) and 17 (20.5%) of 83 isolates by using DDS method with a distance of 25 and 22-20 mm between antibiotic disks, respectively. Agar screening plates demonstrated 16 (19.3%) ESBL positive isolates and was more sensitive compared to DDS method with 25 mm distance between disks. However, agar screening method gave a successful presumptive bacterial identification in only 10 of 16 ESBL positive isolates. In conclusion, the potential of the new agar screening test in direct identification of ESBL production in clinical samples should be evaluated.