Antibiotic susceptibility of Pseudomonas aeruginosa isolated at 108 Military Central Hospital from 01/2020 to 06/2022

Objective: To determine antibiotic susceptibility patterns of Pseudomonas aeruginosa isolated at the 108 Military Central Hospital from January 2020 to June 2022. Subject and method: A total of 784 Pseudomonas aeruginosa strains were isolated from patient specimens from different departments. Bacteria identification and antibiotic susceptibility test were performed using the Vitek MS system and the Vitek-2 Compact system, respectively. Multidrug-resistant and/or carbapenem-resistant Pseudomonas aeruginosa (MDR/CPR P. aeruginosa) strains were determined. Colistin susceptibility test was done using cation-modified Muller-Hinton broth diffusion method (CBDE, colistin broth disk elution). Result: Pseudomonas aeruginosa was highly resisting to fluoroquinolones (62.8%), and aminoglycosides (53.4%). The proportion of MDR/CPR P. aeruginosa was 54.3% (426/784), of which the highest proportion was found in the Department of Infectious Diseases (65.52%), ICU (64.39%) and the Internal Respiratory Department (45.69%). Carbapenem-resistant Pseudomonas aeruginosa was highly prevalent in urine specimens (65.38%) and respiratory specimens (56.76%). Of 258 MDR/CPR P. aeruginosa isolates, 11.2% isolates were resistant to colistin, 26.6% and 33.3% of these remained susceptible to amikacin and piperacillin/tazobactam, respectively. Conclusion: The prevalence of antibiotic resistante Pseudomonas aeruginosa remains high, including resistance to carbapenem and colistin. Antibiotic regimen should include amikacin or piperacillin/tazobactam in combination with other antibiotics. The study suggested the routine application of diagnostic tools for the rapid detection of resistant strains.