荧光染色法与革兰染色法检测痰标本细菌的对比研究

Objective To compare the diagnostic efficacy of fluorescence staining method and gram staining method in detecting bacteria in sputum specimens, and to explore the application value of fluorescence staining method in the screening of pathogenic bacteria in clinical sputum specimens. Methods A total of 420 sputum samples from patients with suspected respiratory tract infection collected in our center from January 2024 to December 2025 were selected as the study objects. The results of bacterial culture were used as the gold standard, and the fluorescent staining method(fluorescent dye labeling bacterial cell wall, fluorescence microscopy observation) and Gram staining method(traditional crystal violet, iodine solution, ethanol and safranin staining) were used at the same time and observed under an optical microscope. The bacterial detection rate, sensitivity, specificity, positive predictive value, negative predictive value and detection time of the two staining methods were compared. Results Bacterial culture results were used as the gold standard. Among 420 sputum samples, 306(72.86%) were positive and 114(27.14%) were negative. The detection rate of bacteria by fluorescence staining method was significantly higher than that by Gram staining method(P<0.05). The sensitivity, negative predictive value and accuracy of fluorescence staining were higher than those of Gram staining(P<0.05). The average time of fluorescence staining was shorter than that of Gram staining(P<0.05). There was no difference in the detection rate of Gram-positive bacteria between the two detection methods, while the detection rate of Gram-negative bacteria by fluorescent staining method was higher than that by Gram staining method(P<0.05). Conclusion Fluorescence staining has higher detection rate, sensitivity and accuracy in the detection of bacteria in sputum samples, and it is simple to operate and takes less time, especially in the identification of Gram-negative bacteria. This method is suitable for rapid bacterial screening of sputum samples in primary centers for disease control and prevention, and can be used as an important supplement or alternative method to the traditional Gram staining method, which is helpful in improving the efficiency of etiological diagnosis of respiratory tract infections.