Clinical Risk Factors and Antimicrobial Resistance Patterns of Multidrug Resistant Enterobacter cloacae Isolates from Hospitalized Patients.

Background Enterobacter cloacae is considered an important hospital-acquired pathogen associated with bloodstream, respiratory, and wound infections. Its increasing ability to acquire multidrug-resistant (MDR) traits poses a serious challenge for both infection control and therapeutic management. This study aimed to determine the antimicrobial resistance profiles, prevalence of MDR, and associated clinical risk factors of E. cloacae isolated from hospitalized patients. Methods Four hundred clinical specimens such as blood, pus, and sputum were collected between July 2024 and July 2025 from hospitalized patients suspected to have a bacterial infection. Risk-factor data were obtained through medical record review. Manual and automated identification with antimicrobial susceptibility testing were performed using the BD Phoenix™ automated microbiology system. Results Most infected patients with E. cloacae were male (64%) and aged 60 years or older (56%). Significant risk factors associated with MDR E. cloacae infections included prior antibiotic exposure (p = 0.008), hospitalization longer than 10 days (p = 0.021), and ICU admission (p = 0.034). All isolates (100%) were resistant to ampicillin, amoxicillin–clavulanate, cefazolin, and cefuroxime. Third- and fourth-generation cephalosporins (ceftazidime 70%, cefepime 70%, ceftriaxone 64%), along with ciprofloxacin (44%), levofloxacin (44%), and tigecycline (50%), showed high resistance rates, indicating reduced activity of major antibiotic classes. Imipenem resistance was detected in 34% of isolates, while amikacin (10%), meropenem (10%), and ertapenem (10%) retained good activity. Ceftolozane–tazobactam remained fully effective (100% susceptibility). The overall prevalence of MDR was 86%. Conclusion A high prevalence of MDR E. cloacae was identified among hospitalized patients, with strong associations to ICU stay, prolonged hospitalization, and prior antibiotic use. Despite widespread resistance to β-lactams and fluoroquinolones, ceftolozane–tazobactam, amikacin, meropenem, and ertapenem remain effective therapeutic options. The findings emphasize the importance of strengthening local antimicrobial stewardship programs and establishing region-specific surveillance data to guide empirical treatment and support infection-prevention strategies.