CLINICAL LABORATORY, cilt.69, sa.5, ss.1-11, 2023 (SCI-Expanded)
Background: Multidrug-resistant organisms cause to serious
infections with significant morbidity and mortality in the worldwide. These
organisms have been identified as urgent and serious threats. The aim of this
study was to determine the prevalence and changes of antibiotic resistance of
multidrug-ressistant pathogens isolated from blood cultures over a four-year
period in a tertiary-care hospital.
Methods: Blood cultures were incubated in blood
culture system. Positive signalling blood cultures were subcultured on 5%
sheep-blood agar. Identification of isolated bacteria was performed using
conventional or automated identification systems. Antibiotic susceptibility
tests were performed by disc diffusion and/or gradient test methods, if
necessary, by automated systems. The CLSI guidelines were used for interpretatiton
of antibiotic susceptibility testing of bacteria.
Results: The most frequently isolated Gram-negative
bacteria was Escherichia coli (33.4%) followed by Klebsiella
pneumoniae (21.5%). ESBL positivity was 47% for E. coli, 66% for K.
pneumoniae. Among E. coli, K. pneumoniae, Pseudomonas
aeruginosa and Acinetobacter baumannii isolates, carbapenem
resistance was 4%, 41%, 37%, and 62%, respectively. Carbapenem resistance of K.
pneumoniae isolates has increased from 25% to 57% over the years, and the
highest rates (57%) was occured during the pandemic period. It is noteworthy
that the aminoglycoside resistance in E. coli isolates gradually
increased from 2017 to 2021. The rate of methicillin-resistant S. aureus
(MRSA) was found to be 35.5%.
Conclusions: Increased carbapenem resistance in K.
pneumoniae and A. baumannii isolates is noteworthy, but carbapenem
resistance in P. aeruginosa decreased. It is of great importance for
each hospital to monitor the increase in resistance in important microorganisms,
especially isolated from invasive samples, in order to take the necessary
precautions in a timely manner. Future studies involving clinical data of
patients and bacterial resistance genes are warranted.