Rapid detection of the bacterial drug susceptibility testing based on AIE technology / 中华检验医学杂志

ABSTRACT

Objective:Based on the principle that the aggregation-induced emission (AIE) fluorescent probe 6PD-DPAN could bind and aggregate with bacteria, and the fluorescence intensity could reflect the quantity of bacteria, a new method for rapid, convenient, and accurate bacterial drug sensitivity testing was established, which provided a basis for rapid and accurate clinical drug use.Methods:This was a methodological evaluation study. A total of 107 clinical isolates were collected from Houjie Hospital of Dongguan City from January to December 2022, among which 46 isolates were used for the establishment of the new method, and 61 isolates were used for methodological validation. The minimum inhibitory concentration (MIC) determined by broth microdilution method was used as the gold standard, and three antibacterial drugs, gentamicin, levofloxacin, and cefotaxime, were used as experimental drugs. The AIE plate was incubated for 4 hours, and the fluorescence intensity was measured every half an hour to draw a fluorescence change curve. The MIC results were compared with the CLSI breakpoints to determine the bacteria as sensitive, intermediate, or resistant. To simplify the detection process, the ratio of fluorescence intensity at 4 hours(R) was calculated, and the ROC curve was used to analyze the efficacy of R in determining bacterial growth and establish its cutoff value. The new method was used to determine the MIC of 61 clinical isolates, with broth microdilution method as the gold standard. The basic consistency, categorical consistency, very major errors, and major errors of the new method were analyzed, and the consistency between the two methods was determined by the Kappa test.Results:ROC curve analysis of the R after 4 hours of culture: The cut-off value was 3.0, with both sensitivity and specificity for determining bacterial growth being 100%. The median (interquartile) R for bacterial growth inhibition was 11.1 (8.6, 14.4); the median R-value for bacterial growth was 1.1 (1.0, 1.2). Compared to the gold standard, the newly established method showed 100% (61/61) essential agreement in detecting MICs of 61 clinical isolates, with a categorical agreement of 96.7% (59/61). There were no very major or major errors, and the Kappa value was 0.94, indicating good consistency between the newly established method and the microbroth dilution method.Conclusions:This study successfully established a new method for bacterial drug sensitivity testing based on AIE technology, which could obtain satisfactory results within 5 hours, providing a basis for early precision drug treatment in clinical practice.