Determination of antibiotic resistance levels of gram (-) bacteria isolated from Harsit Stream estuary

The aim of this study is to investigate the antibiotic resistance levels of Gr (-) bacteria isolated from Harşit Stream Estuary, Giresun. The surface water samples were collected from three different stations between June 2015 and May 2016 with a sterile dark glass bottle wait an ice box. Gram (-) bacteria were isolated with selective media. Additionally, disk diffusion method was evaluated for determining of antibiotic resistance levels of Gr (-) isolates. Antibiotic resistance levels of isolates was determined; Amikacin (AK): 93,36%, Erythromycin (E): 85,70%, Ampicillin (AMP): 37,58%, Tetracycline (TE): 22,77%, Cefazolin (KZ): 17,95%, Cefuroxime (CXM): 13,48%, Cefotaxime (CTX): 11,68%, Nalidixic acid (NA): 10,84%, and Chloramphenicol (C): 7%, respectively. Also, multidrug resistance index values of 86,74% of the isolates were higher than the reference value and the mean antimicrobial resistance index (ARI) recorded was 0,4. As a result of present findings of this study showed that high resistances of Gr (-) bacteria against to commercial antibiotics, and this situation indicated antibiotic pollution in Harşit Stream Estuary.