Identification of Pseudomonas Aeruginosa Isolated from Burn Patients by Nested Polymerase Chain Reaction: Special reference to comparison with conventional blood culture

ABSTRACT

PURPOSE: Pseudomonas aeruginosa has emerged as one of the most problematic bacteria in modern hospital settings, and this organism is increasingly isolated as a nosocomial pathogen. Burn patients are particularly susceptible to Pseudomonas infection. Therefore, the accurate and sensitive microbiologic tests are needed for strict management of this prevalent microorganism. METHODS: A nested polymerase chain reaction test based on consecutive amplification of the lipoprotein genes, oprL and oprI, was designed and evaluated, in comparison with the conventional blood culture, for its ability to detect Pseudomonas aeruginosa in clinical materials of burn patients. RESULTS: Positive results of PCR based on oprL gene were observed only for Pseudomonas aeruginosa. All other bacteria (n=4) tested by this amplification method were negative. Also the lowest detection level was 1X101 bacteria per ml of blood samples. In addition, PCR afforded a significantly higher detection rate for Pseudomonas aeruginosa than the conventional blood culture technique in clinical materials of burn patients (25.9% vs. 8.6%). CONCLUSION: This study suggests that the nested PCR technique is highly specific and sensitive test for detectionof Pseudomonas aeruginosa, and therefore it may be a useful adjunct tool, in combination with other conventional techniques, for detection of Pseudomonas aeruginosa infection.