Prevalence and Distribution of Bacterial Isolates from Blood Cultures Among Patients with Fever: A Retrospective Study

Abstract

Abstract

Background: Bloodstream infections (BSIs) remain a critical cause of morbidity and mortality worldwide, particularly among patients presenting with fever. Understanding the local epidemiology of bacterial isolates recovered from blood cultures is essential for guiding empirical antimicrobial therapy and improving clinical outcomes.

Objective: This study aimed to determine the prevalence, distribution, and antimicrobial susceptibility profiles of bacterial isolates recovered from the blood cultures of patients presenting with fever.

Materials and Methods: This retrospective cross-sectional study involved the analysis of 186 blood culture records from patients presenting with fever. Blood samples were examined using routine microbiological procedures, including inoculation on appropriate culture media, biochemical identification of bacterial isolates, and antimicrobial susceptibility testing using the disk-diffusion method. Demographic data, including age and sex, as well as culture results, identified organisms, and antimicrobial susceptibility profiles, were retrieved and analysed.

Results: Of the 186 blood cultures analysed, 33 (17.7%) yielded bacterial growth, whereas 153 (82.3%) showed no growth. Gram-positive organisms constituted the majority of isolates, accounting for 72.7% (n = 24), with Staphylococcus haemolyticus (n = 12, 36.3%) and Staphylococcus aureus (n = 11, 33.3%) being the predominant species. Gram-negative organisms represented 24.2% (n = 8) of all positive cultures. Female patients comprised 55.4% of the study population and showed a slightly higher culture-positivity rate of 18.4% compared with 16.8% among male patients. High rates of multidrug resistance were observed, particularly among Staphylococcus isolates, whereas vancomycin and linezolid retained complete antimicrobial activity against the tested Gram-positive isolates.

Conclusions: The predominance of Gram-positive organisms among positive blood cultures highlights the importance of local epidemiological surveillance in guiding empirical antimicrobial therapy. The high prevalence of multidrug resistance, particularly among Staphylococcus isolates, demonstrates the urgent need for effective antimicrobial stewardship programmes and continuous monitoring of resistance trends to support evidence-based treatment protocols and improve patient outcomes.