Introduction: There are limited treatments options for carbapenem resistant Enterobacteriaceae (CRE) species and especially colistin, fosfomycin and tigecyclin are used for treatment. Therefore, in this study, we aimed for determining the rates of antibiotic susceptibility against colisting, fosfomycin and tigecyclin in CRE isolates with microdilution method.
Material and Method: In our study, a total of 63 isolates, which were isolated from blood, urine and tracheal aspirate samples. Bacteria identification of the isolates was made with MALDI-TOF MS (Bruker Biotyper; Germany) device. Imipenem, meropenem and ertapenem susceptibilities were determined with the gradient strip test (Liofilchem, Italy) method and genotypic properties were determined with the PCR method. Colistin (0.06-32 μg/ml), fosfomycin (0.06-32 μg/ml) and tigecyclin (0.25-256 μg/ml) M?K values were determined with the microdilution method.
Results: Of the isolates included in the study, 60 isolates (95.24%) were defined as Klebsiella pneumoniae, 2 (3.17%) as Escherichia coli and 1 (1.59%) as Enterobacter cloacae. 57 isolates (90.48%) had OXA-48, 4 (6.35%) had NDM and 2 (3.17%) had OXA-48 and NDM resistant genotypes. M?K50 values for colistin, fosfomycin and tigecyclin were 0.50, 4 and 0.25 M?K90 values were 1, 16 and 1, respectively. Two isolates (3.17%) had resistance to colistin, 23 (63.51%) to fosfomycin and 18 (28.57%) to tigecyclin.
Conclusion: Under the light of the findings of the study, we believe colistin, fosfomycin and tigecyclin can be alternatives for CRE treatment, however, local and national level surveillance studies are important and treatment protocols should be organized and dosage should be arranged based on this surveillance data.