Screening And Evaluation Of Method For Inactivation Of Bacteria In Blood

In this study, E.coli ,P.aeruginosa, S.aureus, S.epidermidis have been used as test bacteria. 4 common blood disinfection methods(UVC irradiation, activated carbon-iodine, MB photochemical treatment, 8-MOP photochemical treatment) have been screened initially .After the best method of disinfection has been chose, the best inactivating condition of this method was screened by the orthogonal assay, and the influence on major components and functions of dinsfected blood was decided on by the techniques, such as automatic biochemical analysis, SDS-PAGE electrophoresis, cross-immunoelectrophoresis, Enzyme-linked imm-unoadsordent assay, RBC membrane blinding to poly-L-lysine assay,reaction of promoted by ATP enzyme assay and neutrophil swallowing.The mam results are described as follows:1. At the desighed largest dose of screen test, E.coli in blood could reduced respectively by 0.800 log, 1.920 log, 2.772 log, 2.552 log by treated with activated carbon-iodine(3g/10ml), 8-MOP(300μg/ml)plus UVA(3000μW/cm2), UVC(3000μW/cm2), MB(5μmol/l)plus halogen lamp(30000Lux)for 40 min.At the same condition ,the plasma free hemoglobin increased respectively 679.16 mg/l, 16.06 mg/l, 107.70 mg/l, 1.68 mg/l,and prothrombin tune increased respectively 6.40 s, 4.60 s, 5.10 s, 0.80 s.According to the principl of effectively inactivating the bacteria and the best keep of the constituents of blood, MB photochemical treatment has been chose as the disinfection method of the next test.2. The results of orthogonal assays indicaed that,the inactiviaion efficacy for bacterium in blood by MB photochemical treatment was influenced by MB content,the intensity and time of halogen lamp irradiation.The initial screening condition(15 μ mol/LMB, 40000 Lux halogen lamp irradiation intensity, 40 mintime,0.35 mmol/1 rutin )which was the best condition could reduce E.coli about 5 log.The value of T/E of MB and irradiation of halogen lamp was higher than 1.This data indicated that MB and irradiation of halogen lamp have synergetic effects.3.With the best Treated condition, E.coli, P.aeruginosa, S.aureus, S.epidermidis reduced respectively by 5.021og,2.21 log,0.831og,1.081og.In the blood samples which have been diluted with the proportion of 1:4, P.aeruginosa,S.aureus,S.epidermidis could be reduced respectively by 4.05 log, 2.09 log- 3.04 log.4.Through examining by automatic biochemical analysis, SDS-PAGE electrophoresis, cross-immunoelectrophoresis, En2yme-linked immunoadsordent assay, we found that there was not significant change among the plasma of disinfected blood, and its contents of proteins and most biochemical parameters all remained within the normal ranges.5.The result of RBC membrane blinding to poly-L-lysine assay and reaction of promoted by ATP enzyme assay showed that, with MB photochemical treatment for 10-40min,the negative electricity on membrane of RBC was dcreased about 11.23%-25.49%,and treatment for 20-30min,the activity of Na+-K+ATP enzyme on RBC membrane was increased about 7.60%-20.07%.6.The result of neutrophil swallowing assay showed that, with the MB photochemical treatment for 10-20min,the positive rate of NBT swallowing is enhanced.If the treatment time was continuous increased,the positive rate was cut down gradually and reached the value of the common group.