Retrospective determination of antibiotic resistance profiles and detection of resistance genes in clinical isolates of Acinetobacter baumannii

The genus Acinetobacter was first isolated from soil samples by Beijerinck in 1911 and initially identified as Micrococcus calcoaceticus. In 1954, Brisou and Prévot reclassified this group as Gram-negative, non-motile, non-pigmented, non-spore-forming, strictly aerobic, and non-fermentative coccobacilli, based on morphological and biochemical characteristics. The name "Acinetobacter" derives from the Greek word akinetos, meaning "immobile." Acinetobacter spp. are widely distributed in nature and can survive in diverse environmental settings such as soil, water, and hospital surfaces. Among these, Acinetobacter baumannii has emerged as a clinically significant pathogen due to its ability to persist on inanimate surfaces and cause healthcare-associated infections (HAIs). It primarily affects immunocompromised patients, particularly those admitted to intensive care units, undergoing mechanical ventilation, or subjected to invasive procedures like catheterization and tracheostomy. Clinically, A. baumannii is associated with a range of opportunistic infections including pneumonia, sepsis, wound infections, meningitis, and catheter-associated urinary tract infections. Due to its increasing antibiotic resistance and environmental resilience, A. baumannii has become a major global threat in nosocomial infections. The widespread and inappropriate use of broad-spectrum antibiotics has facilitated the emergence and dissemination of multidrug-resistant strains, posing significant challenges for treatment and infection control strategies.