Identification of Bacterial Agents from Blood Samples Based on Phenotypic and Genotypic Methods in Kermanshah, West of Iran

Abstract

Introduction: Sepsis is a syndrome of host systemic inflammatory response and is caused by microbial pathogens invading the bloodstream. Quick and accurate diagnosis is a key factor in the treatment of sepsis before complications occur. Therefore, this study aimed to identify the bacterial agents of sepsis from blood culture using phenotypic and polymerase chain reaction (PCR) techniques. Materials and Methods: A total of 287 blood culture bottles of suspected patients in Imam Reza Hospital were taken and transferred to the microbiology laboratory of the medical school. Isolates were identified by Microgen Kit and API 20 E kit. The PCR sequence analysis of the 16S rDNA gene was implemented for molecular detection of bacterial isolates. Results: Of the 287 suspected sepsis samples, 231 were negative and 56 were positive. Among the positive samples, five were positive by PCR despite being negative in the culture. Among 56 isolates, 16 (28.57%) were Gram-negative bacteria and 40 (71.42%) were Gram-positive bacteria. Conclusion: In this study, the result of PCR-based 16S rDNA gene analysis revealed high sensitivity compared with other methods of bacterial detection. Overall, the fast sampling and quick and accurate diagnosis reduce unnecessary prescription of antibiotics by physicians.

Keywords

• blood culture
• bacterial isolates
• phenotypic identification
• genotypic identification
• polymerase chain reaction