Abstract:Objective To evaluate the detection efficiency of different sampling methods to detect bacterial contamination on the surface of different materials, and explore a sampling method that not only conforms to national standards, but also can simply, quickly and accurately reflect the actual microbial contamination on object surface. Methods Surface of sterilized stainless steel plate and sterilized non-woven fabric were evenly coated with Staphylococcus saprophyticus, after natural drying, object surface were taken samples and detected the total number of bacterial colonies by adenosine triphosphate (ATP) bioluminescence assay, cotton swab smearing method, carrier imprinting method, and membrane filtration method, differences in different sampling methods were compared. Data were analyzed by SPSS 18.0 software. Results Under different contamination concentrations, stainless steel plates and non-woven fabrics had the highest number of bacteria detected by carrier imprinting method, followed by membrane filtration method, while cotton swab smearing method had the lowest number of detected bacteria. When bacterial colonies of non-woven fabric was 106 CFU/mL, the qualified rate of carrier imprinting method (30.0%) was lower than that of cotton swab smearing method (80.0%), membrane filtration method (80.0%) and ATP bioluminescence assay (90.0%), differences were all statistically significant (all P < 0.05). ATP bioluminescence assay was prone to get false negative results. When bacterial concentration was 107 CFU/mL, Pearson correlation coefficient between cotton swab smearing method and ATP bioluminescence assay was 0.838 (P=0.002), detection results of two sampling methods had good correlation. Conclusion Carrier imprinting method is more sensitive than cotton swab smearing method, membrane filtration method and ATP bioluminescence assay for the detection of bacterial colonies contaminated on object surface, carrier imprinting method can be used for the monitoring of bacteria on environmental object surface and hands in medical institutions; ATP bioluminescence assay and cotton swab smearing method have a good correlation to the detection results of bacterial load on artificially contaminated non-woven fabric surface.

Abstract:Objective To evaluate the disinfection effect of a new hypochlorous acid disinfectant on fiberbronchoscopes. Methods 60 used fiberbronchoscopes were strictly cleaned in accordance with the operation procedures, then fiberbronchoscopes were performed machine washing and disinfection with hypochlorous acid disinfectant for 3 and 5 minute respectively. ATP bioluminescence assay and membrane filtration method were used to monitor and evaluate the disinfection effect on the outer and inner surface of fiberbronchoscopes,result was compared with before cleaning and enzyme washing. Results The median value of relative light unit(RLU) on the outer surface of 30 used fiberbronchoscopes before cleaning was 911.5, qualified rate was 16.7%; after enzyme washing but before machine washing, the median value of RLU on the outer surface of fiberbronchoscopes was 234.0, qualified rate was 43.3%. After each group of 30 fiberbronchoscopes were immersed in disinfectant for 5 and 3 minutes respectively, median values of RLU of the outer surface of fiberbronchoscopes were 25.0 and 23.5 respectively, qualified rates were both 100.0%. Concentration of hypochlorous acid disinfectant could maintain at effective concentration (≥ 80 mg/L) after continuous use for 7 days. Conclusion The new hypochlorous acid disinfectant can achieve good disinfection effect on fiberbronchoscopes for 3-minute contact time, and improve work efficiency with good safety and stability.

Abstract:Objective To compare and analyze the efficacy and cost of endoscope cleaning and disinfection detected with membrane filtration method and smear method. Methods Endoscopes after cleaning and disinfection in a large tertiary first-class general hospital from January to December 2018 were randomly selected, cleaning and disinfection efficacy of endoscopes were detected with membrane filtration method and smear method respectively, the qualified rate, pathogen detection rate, bacterial colony count and cost between two methods were compared, QuestionStarTM and WeChat platform were used to investigate the current status of detection methods for endoscope cleaning and disinfection efficacy in some hospitals. Results A total of 207 flexible endoscopes were detected. The qualified rates of endoscopes detected with membrane filtration method and smear method were 78.26% and 95.65% respectively, difference was statistically significant (P<0.001). After endoscopes were cleaned and disinfected, pathogen detection rate and bacterial colony count detected with membrane filtration method were both higher than smear method, difference was statistically significant (P<0.001). Compared with smear method, economic cost of 207 endoscopes detected with membrane filtration method increased by 1 498.48 yuan per year, with an average increase of 7.24 yuan per endoscope. On average, each endoscope detected with membrane filtration method took 62 seconds longer than smear method. A total of 26 hospitals were investigated endoscope cleaning and disinfection detection methods, only 2 hospitals adopted membrane filtration method. For membrane filtration method to detect the cleaning and disinfection efficacy of endoscopes, the most important issue concerned by hospitals was increased economic cost. Conclusion Membrane filtration method can effectively cultivate bacteria in the eluent of endoscopes and objectively reflect the cleaning and disinfection efficacy of endoscopes.

Abstract:ObjectiveTo evaluate membrane filtration (MF) method and agar plate pouring (AP) method for detecting endoscopy disinfection efficacy. MethodsDisinfection efficacy of all endoscopes in a hospital were detected and evaluated with MF method and AP method. ResultsA total of 192 disinfected endoscopes were detected, 96 were detected with MF method and 96 were detected with AP method, according to the detected bacterial colony count, disinfected endoscopes were divided into 0, 1-10, 11-20, 21-300, and > 300 CFU/piece groups, ranksum test results showed differences in distribution of colony count of disinfected nasopharyngoscopes, bronchoscopes, gastroscopes, and enteroscopes were significant(all P<0.05), bacterial colony count detected by MF method was higher than AP method. Qualified rate of endoscope disinfection detected by AP method was 91.67%, MF method was 88.54%, there was no significant difference in qualified rate between two methods (χ2=0.53, P=0.630). ConclusionMF method is more accurate than AP method to detect bacterial colony count remained in the endoscope after disinfection, it is worth to be popularized.