Bloodstream Infections in the Intensive Care Unit: a Single-Center Retrospective Bacteriological Analysis Between...

Area of Science:

• Clinical Microbiology
• Infectious Diseases
• Public Health

Background:

• Hospital-acquired bloodstream infections (HA-BSI) pose a significant global health threat, leading to increased morbidity and mortality.
• Effective management of HA-BSI relies on understanding local epidemiological patterns and antimicrobial resistance profiles.

Purpose of the Study:

• To analyze the spectrum of pathogens causing bloodstream infections in intensive care unit (ICU) patients.
• To determine the antimicrobial susceptibility patterns of isolated pathogens over a 13-year period (2007-2019).
• To identify challenges in treating multidrug-resistant organisms (MDROs) in the ICU setting.

Main Methods:

• Retrospective analysis of blood culture data from ICU patients at the Military Institute of Medicine, Poland (2007-2019).
• Microbiological analysis of 12,619 blood samples, including pathogen identification and antimicrobial susceptibility testing.
• Specific focus on identifying Gram-negative bacteria, Gram-positive cocci, and fungi, along with resistance mechanisms like ESBL, NDM, KPC, and MRSA.

Main Results:

• A total of 1,509 positive blood cultures yielded 1,557 pathogens; 278 cases were associated with central line-associated bloodstream infections.
• Gram-negative bacteria predominated (770/1,557), with *Acinetobacter baumannii* (312/770) and *Klebsiella pneumoniae* (165/770) being most frequent. High rates of resistance, including ESBL, NDM, and KPC, were observed in *K. pneumoniae*.
• Staphylococci (545/733) were the main Gram-positive isolates, including methicillin-resistant *Staphylococcus aureus* (MRSA) (58/545). Vancomycin remained effective against MRSA and MRCNS, while colistin was crucial for certain carbapenem-resistant Gram-negative infections.

Conclusions:

• The study highlights a concerning prevalence of multidrug-resistant Gram-negative bacteria in the ICU, necessitating stringent infection control measures.
• Antimicrobial stewardship programs are vital to preserve the efficacy of last-resort antibiotics like colistin and vancomycin.
• Continuous surveillance of HA-BSI epidemiology and resistance patterns is essential for guiding empirical treatment strategies and improving patient outcomes.