Using the rate of bacterial clearance determined by real-time polymerase chain reaction as a timely surrogate marker to evaluate the appropriateness of antibiotic usage in critical patients with Acinetobacter baumannii bacteremia
Journal
Critical Care Medicine
Journal Volume
40
Journal Issue
8
Pages
2273-2280
Date Issued
2012
Author(s)
Abstract
OBJECTIVE: Bacteremia caused by Acinetobacter baumannii is becoming more frequent among critically ill patients, and has been associated with high mortality and prolonged hospital stay. Multidrug resistance and delay in blood culture have been shown to be significant barriers to appropriate antibiotic treatment. Quantitative polymerase chain reaction assays were recently used to monitor bacterial loads; we hypothesized that the rate of bacterial clearance determined by quantitative polymerase chain reaction can be used as a timely surrogate marker to evaluate the appropriateness of antibiotic usage. DESIGN: Prospective observational study. SETTING: University hospital and research laboratory. PATIENTS: Patients with culture-proven A. baumannii bacteremia in the intensive care units were prospectively enrolled from April 2008 to February 2009. INTERVENTIONS: Plasmid Oxa-51/pCRII-TOPO, which contained a 431-bp fragment of the A. baumannii-specific Oxa-51 gene in a pCRII-TOPO vector, was used as the standard. Sequential bacterial DNA loads in the blood were measured by a quantitative polymerase chain reaction assay. MEASUREMENTS AND MAIN RESULTS: We enrolled 51 patients with A. baumannii bacteremia, and examined 318 sequential whole blood samples. The initial mean bacterial load was 2.15 log copies/mL, and the rate of bacterial clearance was 0.088 log copies/mL/day. Multivariate linear regression using the generalized estimation equation approach revealed that the use of immunosuppressants was an independent predictor for slower bacterial clearance (coefficient, 1.116; p < .001), and appropriate antibiotic usage was an independent predictor for more rapid bacterial clearance (coefficient, -0.995; p < .001). Patients with a slower rate of bacterial clearance experienced higher in-hospital mortality (odds ratio, 2.323; p = .04) CONCLUSIONS: Immunosuppression and appropriate antibiotic usage were independent factors affecting the rate of clearance of A. baumannii bacteremia in critical patients. These findings highlight the importance of appropriate antibiotic usage and development of effective antibiotics against A. baumannii in an era of emerging antibiotic resistance. The rate of bacterial clearance could serve as a timely surrogate marker for evaluating the appropriateness of antibiotics. Copyright ? 2012 by the Society of Critical Care.
SDGs
Other Subjects
antibiotic agent; cefepime; colistin; imipenem; immunosuppressive agent; sulbactam; tigecycline; virus DNA; Acinetobacter infection; adult; aged; antibiotic therapy; article; bacteremia; bacterial clearance; bacterial load; bacterium culture; blood sampling; controlled study; critically ill patient; female; human; intensive care; major clinical study; male; mortality; observational study; priority journal; prospective study; quantitative assay; real time polymerase chain reaction; university hospital; Acinetobacter baumannii; Acinetobacter Infections; Anti-Bacterial Agents; Bacteremia; Bacterial Load; Biological Markers; Critical Illness; DNA, Bacterial; Female; Humans; Intensive Care Units; Male; Middle Aged; Prospective Studies; Real-Time Polymerase Chain Reaction
Type
journal article