Bloodstream infections (BSIs) caused by multidrug-resistant bacteria, such as carbapenem-resistant Acinetobacter baumannii (CRAB), are severe and life-threatening. CRAB infections are particularly challenging due to high mortality rates and limited treatment options. Carbapenem antibiotics, like imipenem and meropenem, are critical for treating these infections, but resistance rates have been rising in China, reaching 73.7% and 73.4% in 2023. OXA-23 carbapenemase is a major cause of resistance in CRAB. This study developed a dual qPCR method targeting 16sRNA and OXA-23 to detect CRAB in BSIs. The method demonstrated high sensitivity (LOD: 3×10-3 ng/μl), a wide linear range, and good repeatability (CV ≤ 2%). Clinical validation showed 100% accuracy, making this method a promising tool for rapid and accurate CRAB detection in BSIs.
Bloodstream infections (BSIs) caused by multidrug-resistant bacteria, such as carbapenem-resistant Acinetobacter baumannii (CRAB), are severe and life-threatening. CRAB infections are particularly challenging due to high mortality rates and limited treatment options. Carbapenem antibiotics, like imipenem and meropenem, are critical for treating these infections, but resistance rates have been rising in China, reaching 73.7% and 73.4% in 2023. OXA-23 carbapenemase is a major cause of resistance in CRAB. This study developed a dual qPCR method targeting 16sRNA and OXA-23 to detect CRAB in BSIs. The method demonstrated high sensitivity (LOD: 3×10-3 ng/μl), a wide linear range, and good repeatability (CV ≤ 2%). Clinical validation showed 100% accuracy, making this method a promising tool for rapid and accurate CRAB detection in BSIs.
Bloodstream infections (BSIs) are severe, life-threatening systemic infections caused by various pathogens. Among these, infections caused by multidrug-resistant bacteria, particularly carbapenem-resistant gram-negative bacilli, are associated with high mortality rates. Acinetobacter baumannii (A. baumannii), a gram-negative bacillus, is a significant cause of nosocomial infections. Timely and accurate identification of the causative pathogen and its antibiotic resistance is critical for effective treatment.
Carbapenem antibiotics, such as imipenem and meropenem, are considered the最后一道防线 against A. baumannii infections. However, the emergence of carbapenem resistance poses a serious threat to patient outcomes. According to data from the China Antimicrobial Surveillance Network, resistance rates of A. baumannii to imipenem and meropenem have remained high, with a year-on-year increasing trend observed between 2016 and 2023.
OXA-type carbapenemases, specifically the OXA-23 gene, are the primary contributors to carbapenem resistance in A. baumannii. This gene is predominantly found in carbapenem-resistant A. baumannii (CRAB) but is absent in carbapenem-sensitive A. baumannii (CSAB). This association underscores the importance of detecting the OXA-23 genotype to identify resistant strains.
To address the need for rapid and accurate diagnosis, this study developed a dual qPCR method targeting the 16sRNA gene (for A. baumannii identification) and the OXA-23 gene (for carbapenem resistance detection). The method was optimized to ensure specificity, sensitivity, and repeatability, demonstrating a detection limit of 3×10⁻³ ng/μl and a wide dynamic range. Clinical validation confirmed the method’s effectiveness in detecting CRAB in blood samples, providing a valuable tool for timely intervention and treatment optimization.
This dual qPCR approach offers a cost-effective and efficient alternative to traditional methods, with significant potential for clinical application in improving outcomes for patients with BSIs.
