Abstract
Background: Pseudomonas aeruginosa is a common opportunistic pathogen that causes nosocomial
infection in immunocompromised patients. Among different virulence factors, the type III secretion system
(TTSS) is an important agent in virulence and development of antimicrobial resistance in P. aeruginosa.
Previous studies have shown that production of TTSS proteins was correlated with increasing virulence
and resistance to several antibiotics. In this study, the exotoxins genes (exoU and exoS) and pattern of
antimicrobial susceptibility in clinical P. aeruginosa isolates were determined.
Methods: A total of 175 P. aeruginosa isolates were collected from patients hospitalized in Shahrekord
and Chamran educational hospitals of Isfahan, Iran (during April to December 2015). Antimicrobial
susceptibility test was performed by disk diffusion test. The presence of exotoxin genes was detected using
multiplex polymerase chain reaction (PCR) of exoU and exoS genes.
Results: The antibiotic resistance rate was higher than 70% to many antibiotics. The highest rates of
resistance (155 and 148)