A novel multiplex PCR for detection of Pseudomonas aeruginosa: A major cause of wound infections

Background and Objective: Wound infections are often difficult to treat due to various bacterial pathogens. Pseudomonas aeruginosa is one of the common invaders of open wounds. Precise diagnosis of this etiological agent in wound infections is of critical importance particularly in treatment of problematic cases. The existing diagnostic methods have certain limitations particularly related to specificity. Our objective was to to establish a comprehensive and reliable multiplex PCR to confirm diagnosis of P. aeruginosa.

Methods: A multiplex PCR test was developed for rapid and comprehensive identification of P. aeruginosa. Four highly specific genes were targeted simultaneously for detection of genus, species and exotoxin production (16S rDNA, gyrB, oprL and ETA) in P. aeruginosa; additionally one internal control gene invA of Salmonella was used. The specificity of the multiplex PCR was confirmed using internal and negative controls. Amplified fragments were confirmed by restriction analysis and DNA sequencing.

Results: The developed method was applied on 40 morphologically suspected P. aeruginosa isolates (from 200 pus samples) and 18 isolates were confirmed as P. aeruginosa. In comparison, only 12 could be identified biochemically.

Conclusions: Combination of the four reported genes in multiplex PCR provided more confident and comprehensive detection of P. aeruginosa which is applicable for screening of wound infections and assisting treatment strategy.