Objective: Respiratory infections are important health problems that cause mortality and morbidity. This study was planned to determine the microorganisms growing in tracheal aspirate samples of patients in intensive care units and the antimicrobial resistance profiles of frequently isolated bacteria.

Methods: The bacterial diversity and antimicrobial resistance of bacteria isolated from 14,144 tracheal aspirate samples, which were sent to microbiology laboratory from intensive care units between 2018 and 2020 and found to be pathogen-positive, were evaluated retrospectively. Patient information and laboratory data were taken from Sisoft Health Information Systems and transferred to the computer environment. Diagnosis of bacteria is done by routine methods; antibiotic resistance was investigated using the disk diffusion method or the automated susceptibility testing system with the VITEK® 2 device.

Results: Gram-negative bacteria grew in 66.0% of tracheal aspirates, and gram-positive bacteria grew in 34.0%. Coagulase-negative staphylococci (20.1%) was the most frequently growing bacteria, followed by Pseudomonas aeruginosa (19.2%), Klebsiella pneumoniae (17.5%), Acinetobacter baumannii (14.5%), and S. aureus (6.5%). The most effective antibiotics were imipenem, meropenem, and amikacin in the gram-negatives, and linezolid and tetracycline in the gram-positives. Gram-negatives showed the highest resistance to amoxocillin/clavulanic acid, piperacillin, and ceftazidime. Among gram-positives, staphylococci have the highest resistance to penicillin, erythromycin, and trimethoprim-sulfamethoxazole; enterococci against SXT; and S. agalactiae against tetracycline and gentamicin.

Conclusion: The high resistance of bacteria frequently isolated from tracheal aspirates to antibiotics used in treatment is a result that limits treatment options and requires infection control measures to be taken into consideration.