Characterizing the Incidence and Trends of Bloodstream Infections in an ICU Setting: A Retrospective Analysis of Five Years in Mashhad, Iran

Background: Intensive care unit (ICU) patients are often found to have bloodstream infections. Objectives: This investigation aimed to analyze the antimicrobial utilization patterns in blood cultures within the ICU of the leading educational hospital in northeastern Iran. Methods: Blood samples collected from ICU patients at Imam Reza Hospital in Mashhad, Iran, between 2017 and 2021 were retrospectively examined. Medical records were used to extract patient data, and GraphPad Prism 6.0 and SPSS software (version 16) were used for statistical analysis. Results: Of the total study participants (n = 8013), 3932 (49%) were male. The mortality rate in the ICU ward was 51% (n = 4122), which was higher in males compared to females (55% vs. 45%). Of the total ICU patients, 1265 (16%) showed bacterial growth, and 29 different kinds of pathogens were identified. Gram-positive bacterial species were more frequently isolated, with a total of 607 cases, compared to gram-negative bacterial species, which accounted for 587 cases. The most commonly identified pathogens responsible for bloodstream infections were Acinetobacter spp. and Klebsiella spp. Among them, methicillin-resistant Staphylococcus aureus was observed in 60% of the cases. Furthermore, 18% of Klebsiella infections and 50% of Acinetobacter infections contained multidrug-resistant gram-negative bacteria. Conclusions: The findings revealed a concerning increase in multidrug-resistant strains among the detected microbes, providing valuable information on antimicrobial susceptibility patterns, which can help guide antibiotic selection and dosing.