SDS-NaOH solution for rapid discrimination of gram-positive and gram-negative bacteria in urine / 第二军医大学学报

ABSTRACT

Objective To explore the efficiency of SDS-NaOH solution for discriminating Gram-positive and Gram-negative bacteria in urine. Methods Seventy-nine urine samples were treated with SDS-NaOH solution for 5 minutes. The bacterium counts were determined by UF-1000i urine analyzer before and after treatment, and the bacteria ratio (BR) was calculated. Receiver operation characteristics (ROC) curve analysis was used to assess the discrimination efficiency of B.R. Results BR in Gram-negative bacteria contained urine was significantly lower than that in Gram-positive one (P=0.01). The area under curve (AUC) of BR for discriminating Gram-positive and Gram-negative bacteria was 0.70 (95% confidence interval0.57-0.82). At a cut-off value of 0.05, the discrimination sensitivity and specificity of BR for Gram-positive bacteria were 0.83 (95% confidence interval0.63-0.95) and 0.46 (95% confidence interval0.32-0.59), respectively. Conclusion Treatment with SDS-NaOH solution can help to discriminate Gram-positive and Gram-negative bacteria in urine, and the method is rapid and automatic.