Abstract
OBJECTIVE: Bloodstream infections(BSIs) caused by carbapenem-resistant Acinetobacter baumannii (CRAB) have a high mortality rate due to the high levels of drug resistance. There is an urgent need to establish a sensitive and accurate detection method to rapidly detect CRAB in BSIs. METHODS: A new method was developed based on fluorescence quantitative PCR (qPCR) targeting the specific region of 16sRNA and OXA-23 gene from CRAB. The parameters were evaluated and optimized. This qPCR method was further applied in the detection of AB from 30 clinical specimens. RESULTS: The qPCR method established in this study showed high specificity. The method successfully differentiated Acinetobacter baumannii(A. baumanii) from 26 other common pathogens in BSIs and identify the carbapenem resistance gene. The qPCR method shows a limit of detection (LOD) of 3×10(-3) ng/μL, and displays good linear relationship between 16sRNA and OXA-23 and excellent repeatability (CV ≤2%). The results for the detection of 30 clinical specimens using this new qPCR method are in complete agreement with those using blood culture and drug susceptibility test. CONCLUSION: The qPCR method established in this study has strong specificity, wide linear range, good repeatability, and a lower LOD than PCR (Non-fluorescence quantification). The method provides new technical support for the early clinical diagnosis of CRAB in BSIs.