Background

Antimicrobial resistance (AMR) has emerged as one of the most significant threats to global public health. Hospitals represent critical environments for the emergence and spread of resistant microorganisms due to high antibiotic consumption, vulnerable patient populations, and invasive medical procedures.

Objective

To investigate antimicrobial resistance patterns among clinically significant bacterial pathogens isolated from hospitalized patients and evaluate factors associated with multidrug resistance.

Methods

A retrospective multicenter observational study was conducted across five tertiary-care hospitals from January 2022 to December 2024. A total of 3,500 bacterial isolates obtained from blood, urine, respiratory secretions, wound swabs, and other clinical specimens were analyzed. Antimicrobial susceptibility testing was performed using Clinical and Laboratory Standards Institute (CLSI) guidelines. Resistance rates, multidrug-resistant organism prevalence, and associated risk factors were evaluated.

Results

Among 3,500 isolates, Gram-negative bacteria accounted for 62.4% and Gram-positive bacteria for 37.6%. The most frequently isolated pathogens were Escherichia coli (28.7%), Klebsiella pneumoniae (21.4%), Staphylococcus aureus (18.3%), and Pseudomonas aeruginosa (12.8%). Overall multidrug resistance prevalence was 38.9%. Carbapenem resistance was observed in 22.5% of Gram-negative isolates, while methicillin-resistant Staphylococcus aureus (MRSA) accounted for 41.7% of S. aureus isolates.

Conclusion

High levels of antimicrobial resistance were observed among hospital pathogens, particularly Gram-negative organisms. Strengthening antimicrobial stewardship programs, infection prevention measures, and surveillance systems is essential to mitigate the growing burden of AMR.