Comparative study between molecular and conventional detection methods of pantoea agglomerans isolated from iraqi septicemia patients

Background: Pantoea agglomerans is an opportunistic human bacteria characterized by shaped aggregations or symplas-mata, yellow pigment-producing colonies that were 2 mm in size, nonhemolytic, and convex were detected on a blood agar plate. It belongs to the family Enterobacteriaceae and is responsible for infection diseases ranging from plant-thorn arthritis, osteoitis, osteomyelitis and traumatic wound infections to septicemia. Bacterial identification systems were performed by using manual and automated methods as phenotypic assays, and PCR method as molecular assay. Aims and objectives: The aims of the present study were to review the impact of Pantoea agglomerans in septicemia cases, and study the role of 16S rRNA gene in the molecular detection of Pantoea agglomerans in patients with clinical diagnosis of septicemia. Materials and Methods: In this study blood samples from 75 patients with clinical diagnosis of septicemia were used for blood culture, Gram staining, culture, VITEC-2 Compact and PCR methods. PCR was performed with primer pair targeted to the 16S rRNA gene of Pantoea agglomerans. The result of the PCR was compared with conventional methods of blood culture, Gram staining, culture and VITEC-2 Compact methods. The PCR positive samples were identified by presence of ~1500 bp amplicon of the 16S rRNA gene. Results: Conventional methods of blood culture, Gram staining, culture, VITEC-2 Compact methods showed a positive results in 14 (18,6 %) of 75 patients with clinical diagnosis of septicemia. PCR detected all 14 (18,6 %) samples that were positive by conventional method. Two (2.6 %) of 61 (81,3 %) patients who were negative by conventional methods were positive by PCR method. Statistical analysis revealed that the PCR to have a sensitivity of 95.1 % in the detection of Pantoea agglomerans in septicemia cases. Conclusion: Polymerase chain reaction (PCR) is a rapid, specific and sensitive method to detect Pantoea agglomerans in septicemia cases of human.