Objective: Gram negative bacteria isolated from blood culture samples sent to Microbiology Laboratory between April 2023 and April 2024 and their antibiogram susceptibilities were evaluated retrospectively.

Methods: Bacteria were identified by BD Phoenix 100 Bacterial identification system between 01.04.2023- 10.07.2023, and by MALDI-TOF MS between 11.07.2023-01.04.2024. Antibiotic susceptibilities were determined by Kirby Bauer disc diffusion method and evaluated according to the recommendations of “The European Committee on Antimicrobial Susceptibility Testing”.

Results: Of the isolates, 485 (%75.3) were members of the order Enterobacteriales, 152 (%23.6) were nonfermentary gram negative bacilli (NFGNB) and seven (%1.1) were other gram negative bacilli. When the incidence rates of NFGNBs in clinics were evaluated; the incidence rate in intensive care unit patients was found to be significantly higher than the incidence rates in inpatient ward and outpatient clinic patients (p=0.001). The most common bacteria isolated were Escherichia coli (%35.6), Klebsiella pneumoniae (%24.8), Pseudomonas aeruginosa (%13.5) and Acinetobacter baumannii (%5.9). The highest resistance was observed in ceftazidime (%60.3) and levofloxacin (%66.7) in E. coli isolates. The resistance rate to all antibiotics evaluated in K. pneumoniae isolates was found to be above 30%. The highest antibiotic resistance was observed in imipenem (%32.2) and meropenem (%29.9) in P. aeruginosa isolates. The antibiotic resistance rate of A.baumannii was above 60%.

Conclusion: In conclusion, the most common group among GNBs was found to be members of the Enterobacteriales and the most common bacteria were E. coli and K. pneumoniae. Amikacin, imipenem and meroperem can be used in empirical treatment for E. coli.