Evaluation of PREVI Color Gram Automated Staining System on Positive Blood Culture Samples

Abstract

Objective: This study aims to evaluate the performance of PREVI Color Gram system among positive blood culture samples. Methods: A double-blind study was performed on gram smears prepared by the system using either commercial PREVI Color Gram dyes (n=157) or in-house homemade stains (n=167) and compared to the manual gram-stain method using subsequent culture identification as a reference standard. Results: The automatic method using PREVI Color Gram dyes and the manual method showed 99.2% (120/121) agreement with culture results (single organism). The concordant rate of automatic and manual methods with corresponding culture results (multiple organisms) were 96.3% (26/27) and 100% (27/27), respectively. The automatic method using an in-house homemade stain showed 99.3% (138/139) agreement with culture results (single organism), while the manual method was 98.6% (137/139). The automatic and manual methods gave a 91.7% (22/24) concordant rate with culture results (multiple organisms). Conclusions: PREVI Color Gram system can replace a conventional manual gram-stain method on clinical blood culture specimens. * MRSA : methicillin-resistant Staphylococcus aureus VRE : vancomycin-resistant Enterococci SVR : Spiritus Vinum Rectificatum