Distribution of Microorganisms Isolated from Blood Cultures and Evaluation of Antibiotic Resistance Rates in Patients Diagnosed with Cancer

Objective: Cancer patients are a high-risk population for infections caused by various bacterial agents. Specifically, bloodstream infections (BSIs) can lead to severe complications and even mortality in cancer patients. This study aimed to identify the predominant bacterial species causing bacteremia and assess the prevalence of antibiotic resistance among cancer patients receiving treatment at our hospital. Materials and Methods: Retrospective analysis was conducted on data from cancer patients diagnosed between January 2020 and June. The microorganisms isolated from blood cultures of cancer patients were identified using the matrix-assisted laser desorption ionization (MALDI) Biotyper Microflex LT device. The antimicrobial susceptibility profiles of the bacteria were examined using the BD Phoenix 100. Data analysis was performed using the Statistical Package for the Social Sciences (SPSS) 22.0 program. Results: The study included a total of 158 bacterial isolates grown from blood cultures of 133 patients across different populations. Gram-positive bacteria were detected in 54.4% (86) of the isolates, while gram-negative bacteria were found in 40.5% (64) of the isolates. The extended spectrum beta-lactamase (ESBL) positivity rate was 41.2% (14/34) in Escherichia coli isolates and 25% (3/12) in Klebsiella pneumoniae isolates. Methicillin-resistant Staphylococcus aureus (MRSA) was identified in only one bacterial strain. Nine (26.5%) E. coli isolates and three (25%) K. pneumoniae isolates were determined to be multi-drug resistant (MDR). Conclusion: BSIs remain a significant health issue in cancer patients. Analyzing MDR isolates and resistance profiles through routine bacterial surveillance in cancer patients can provide guidance for antimicrobial therapy. Furthermore, regularly sharing the obtained data can enhance treatment success. Keywords: Bloodstream infections, cancer, antibiotic resistance, population.