Bacterial Etiology and Antimicrobial Resistance Patterns in Respiratory Tract Infections at a Tertiary Care Hospital in Damascus: A Two-Year Cross-Sectional Retrospective Analysis

<ns3:p>Background Armed conflict systematically dismantles the pillars of infection control, creating conditions that foster antimicrobial resistance (AMR). In Syria’s fragmented healthcare landscape, the scarcity of contemporary microbiological data undermines the treatment of common infections like respiratory tract infections (RTIs). This study aimed to define the bacterial etiology and resistance patterns of RTIs at a major Damascus teaching hospital to guide empiric therapy and inform stewardship. Methods We conducted a single-center, retrospective analysis of all non-mycobacterial isolates (n = 309) cultured from routine respiratory specimens (sputum, bronchoalveolar lavage) between January 2022 and December 2023. Antimicrobial susceptibility testing (disk diffusion) followed CLSI guidelines. Multidrug resistance (MDR) was defined as acquired non-susceptibility to at least three distinct antimicrobial classes. Associations between resistance phenotypes were evaluated using Spearman’s rank correlation. Results Among 349 patients, Enterobacteriaceae accounted for 57.6% of isolates, predominantly Enterobacter spp. (33.5%) and Klebsiella pneumoniae (24.1%). An alarming 87.4% of isolates met MDR criteria, with a mean of 5.3 affected drug classes. Carbapenem resistance was near-ubiquitous in K. pneumoniae (73.8%) and Enterobacter spp. (60.7%). A significant correlation between ceftriaxone and meropenem resistance (ρ = 0.72) suggested widespread co-production of ESBLs and carbapenemases. Colistin remained the sole reliable agent against Gram-negatives (69.2–86.5% susceptible), with resistance evolving independently of other classes (ρ ≤ 0.13). Equally concerning, we documented vancomycin resistance in both S. pneumoniae (100%) and S. aureus (14.3%)—findings that, if confirmed, signal an unprecedented therapeutic crisis. Conclusions This study documents an acute, post-antibiotic state for RTIs in a conflict-zone hospital, where empiric options have narrowed to colistin-based regimens for most Enterobacteriaceae. The data provide an essential local baseline, but more importantly, they sound like an alarm. Immediate, aggressive interventions, including enhanced infection control, molecular surveillance, and stringent stewardship, are no longer optional but existentially necessary to preserve the last remaining agents on the formulary.</ns3:p>