1.Study on the influence factors of correction coefficient of biological load in testing the microorganism of medical device
Qun FENG ; Jing LI ; Bin ZHAN ; Guangjuan TIAN ; Xiaoyang LI
China Medical Equipment 2024;21(3):34-38
Objective:To study the different factors that affected the correction coefficient of biological load in microorganism test of medical device,so as to improve the accuracy of testing microorganism of medical device.Methods:According to the national standard"Sterilization of medical devices-Microbiological methods-Part 1:Determination of a population of microorganisms on products"(GB/T 19973.1-2015),the microorganisms of disposable sterile syringes were tested.The vaccination locations of different bacterial strains,the collection techniques of different eluents and the different microorganism count methods were selected to conduct experiment.And then,the correction coefficient of biological load was calculated.Results:Based on the data analysis of the correction coefficient of the biological load of disposable sterile syringes,the difference of the microorganism growth status on plate among three different vaccination locations of bacterial strains(cone head interior,tube inner wall and rubber piston)was statistically significant(F=36.575,P<0.05),and the correction coefficients for recovery rate were respectively 2.9,16.5,and 9.9.The difference of the microorganism growth status on plate among three different microorganism collection techniques(manual shaking for 20 seconds,mechanical shaking for 5 and 20 minutes,200 r/min)was statistically significant(F=119.460,P<0.05),and the correction coefficients for recovery rate were respectively 14.1,7.1 and 1.9.The difference of the microorganism growth status on plate among three different microorganism count methods(coating method,pouring method and membrane filtration method)was not significant(F=0.529,P>0.05),and the correction coefficients for recovery rate were respectively 1.2,1.1 and 1.2.Conclusion:In testing biological load,multiple sites should be selected to conduct simultaneous infection of bacteria,and mechanical shaking should be used to collect eluent.In the test of biological load of medical device,the selection of the sites of bacterial infection and microorganism collection technique are important factor of the correction coefficient of biological load.