THIẾT LẬP MẪU MÁU GIẢ ĐỊNH CHỨA VI KHUẨN STAPHYLOCOCCUS AUREUS DÙNG TRONG NGOẠI KIỂM

Abstract

Objective: Establish a simulated blood sample containing S. aureus achieving the homogeneity and stability in accordance with ISO 17043: 2011 used for the external quality assessement program. Methods: Experimental study was carried out on simulated blood samples containing S.aureus. The growth rate of S. aureus in simulated blood samples with and without boric acid and natriformat was evaluated. Determine suitable concentrations of acid boric and natriformate. One batch of simulated blood samples containing S.aureus with nutrient broth, sheep blood, boric acid and natrifomat in the determined concentration has been prepared. The homogeneity and stability of final samples were evaluated by F test and T-student. Results: The study found that the use of boric acid and natrifomat maintaining the volume of S. aureus in samples (sheep's blood, nutrient broth) was more effectively than not using. Concentrations of boric acid 8% and natriformate 4% are suitable for the production of simulated blood samples with the target bacteria S.aureus. Sample set containing target bacteria S. aureus was homogeneous with  F _reality = 0.911 < F _theory = 3.02 and stable for 17 days. Conclusion: the use of boric acid and natriformat as a preservative in simulated blood sample is appropriate. Successfully establishing the simulated blood sample set containing S. aureus according to ISO 17043: 2011 standards achieves homogeneity and stability in 17 days under the assumed transport conditions of 22⁰C-30⁰C.