Bacterial pathogens and antibiotic resistance in bloodstream infections: A three-year retrospective analysis from a tertiary hospital in Northern Iran

Nilufar Bavafa; Sara  Jamasbi; Tofigh Yaghubi Kalurazi; Meysam Hasannejad-Bibalan

doi:10.61882/jcbior.6.4.333

Authors

Nilufar Bavafa Department of Food Microbiology, Sanjesh Zagros Mokrian Laboratory, Mahabad, Iran https://orcid.org/0009-0009-0796-6426
Sara Jamasbi Razi Clinical Research Development Unit, Razi Hospital, Guilan University of Medical Sciences, Rasht, Iran
Tofigh Yaghubi Kalurazi Razi Clinical Research Development Unit, Razi Hospital, Guilan University of Medical Sciences, Rasht, Iran
Meysam Hasannejad-Bibalan Department of Microbiology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran https://orcid.org/0000-0002-9402-098X

DOI:

https://doi.org/10.61882/jcbior.6.4.333

Keywords:

Bacteria, Respiratory infection, Antibiotic resistance

Abstract

Bloodstream infections (BSIs) are a major contributor to morbidity and mortality among hospitalized patients, particularly when antimicrobial resistance is rapidly increasing. The increasing prevalence of multidrug-resistant bacteria poses significant challenges to empirical treatment and infection-control efforts. This study aimed to determine the prevalence, bacterial etiology, and antimicrobial susceptibility patterns of BSIs among inpatients at a tertiary hospital in northern Iran over a three-year period. A retrospective observational analysis was conducted at a tertiary university hospital from March 2021 to March 2024. All hospitalized patients with culture-confirmed BSIs and documented antimicrobial susceptibility testing results were included. Bacterial identification followed standard microbiological procedures. A total of 284 cases of BSI were recorded, and based on the number of hospital admissions, the rates of nosocomial infection and BSI were approximately 4% and 1%, respectively. The mean patient age was 59.7 years, and 32.4% were admitted to ICUs. Gram-negative bacteria predominated, with Klebsiella spp. (18.3%), Escherichia coli (18.0%), and Acinetobacter spp. (12.7%) as the most frequent pathogens. High antimicrobial resistance rates were observed among Gram-negative isolates, particularly non-fermenters. Carbapenems and aminoglycosides remained the most active agents against Enterobacterales. Among Gram-positive bacteria, approximately half of staphylococcal isolates were methicillin-susceptible, and enterococci showed full susceptibility to vancomycin. BSIs continue to impose a significant clinical burden in northern Iran, dominated by Gram-negative pathogens and marked antimicrobial resistance. The findings highlight the need for ongoing local surveillance, updated empirical treatment guidelines, and reinforced antimicrobial-stewardship and infection-control programs to reduce morbidity, mortality, and the spread of resistant organisms.

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