Antibiotic Susceptibility Pattern of Nosocomial and Community-Acquired Pseudomonas aeruginosa in Isfahan: A Prospective Multicenter Study

Pseudomonas aeruginosa is a ubiquitous bacillus responsible for severe infections in inpatients, especially nosocomial and intensive care unit (ICU) infections.

This study aimed to determine the antibiotic susceptibility of clinical isolates from inpatients in three referral hospitals in Isfahan, Iran.

Standard tests identified the organism and antibiotic susceptibility testing. Stratification was performed by place of infection (community, hospital), admission ward (ICU, non-ICU), and age group (< 20 versus > 20 years).

P. aeruginosa showed high susceptibility to colistin (100%) and amikacin (81.8%) followed by tobramycin (69.2%), ciprofloxacin (68.5%), meropenem (67.2%), cefepime (65.7%), ceftazidime (64.3%), and imipenem (63.3%). Community-acquired strains were significantly more susceptible to meropenem (81.6%), ciprofloxacin (77.1%), cefepime (77.1%), imipenem (74.3%), and ceftazidime (72.2%) than nosocomial strains. Non-ICU isolates were more susceptible to carbapenems. P. aeruginosa isolates had higher antibiotic susceptibility in less than 20 years.

Based on the results, a combination of colistin and amikacin would be appropriate for the empiric treatment of suspected P. aeruginosa infections in severe cases, nosocomial infections, or patients admitted to ICU. Ceftazidime, cefepime, ciprofloxacin, meropenem, or imipenem would be suitable for mild to moderate infections, especially in community-acquired infections.