The comparative survey of phenotypic methods and the BD Phoenix M50 automated microbiology system for detecting the genus of non-fermenting gram-negative bacteria isolated from blood samples in Isfahan, Iran

Abstract

Introduction: A comparative study was conducted to identify the genus and species of non-fermenting gram-negative bacilli isolated from blood culture samples using phenotypic methods and the Phoenix method. Objectives: This study aimed to evaluate the Phoenix system compared to the currently available phenotypic process. Materials and Methods: This descriptive-analytical cross-sectional study evaluated 30 samples collected from 2019 to 2020 from patients at AL Zahra and Kashani hospitals who required blood cultures. The specimens were injected into BACTEC™. Positive cultures identified as non-fermenting gram-negative bacteria by the phenotypic method were included in the study and then evaluated using the Phoenix method to determine the genus and species of non-fermenting gram-negative bacteria. A comparison was then conducted. Results: The study identified 30 non-fermenting gram-negative bacteria. The Phoenix method revealed that 78.5% of the diagnoses were Acinetobacter, while the phenotypic approach identified 86.7% as Acinetobacter spp. Conclusion: The present study demonstrated a significant difference between the Phoenix and phenotypic methods in identifying the type of bacteria.