To explore the effects of plasma jet (PJ) and plasma activated water (PAW) on the sterilization of Streptococcus mutans ( S. mutans) and compare the advantages and disadvantages of the two methods, so as to provide a basis for plasma treatment of dental caries and to enrich the treatment means of dental caries, an atmospheric pressure plasma excitation system was built, and the effects of PJ and PAW on the sterilization rate of S. mutans and the changes of temperature and pH during treatment were studied under different excitation voltage ( U _e ) and different excitation time ( t _e ). The results showed that in the PJ treatment, the difference in the survival rate of S. mutans between the treatment group and the control group was statistically significant ( P = 0.007, d=2.66) when U _e = 7 kV and t _e = 60 s, and complete sterilization was achieved at U _e = 8 kV and t _e = 120 s in the PJ treatment. In contrast, in the PAW treatment, the difference in the survival rate of S. mutans between the treatment group and the control group was statistically significant ( P = 0.029, d = 1.71) when U _e = 7 kV and t _e = 30 s, and complete sterilization was achieved with PAW treatment when U _e = 9 kV and t _e = 60 s. Results of the monitoring of temperature and pH showed that the maximum temperature rise during PJ and PAW treatment did not exceed 4.3 °C, while the pH value after PAW treatment would drop to a minimum of 3.02. In summary, the optimal sterilization parameters for PJ were U _e =8 kV and 90 s < t _e ≤ 120 s, while the optimal sterilization parameters for PAW were U _e = 9 kV and 30 s< t _e ≤ 60 s. Both treatment methods achieved non-thermal sterilization of S. mutans, where PJ required only a smaller U _e to achieve complete sterilization, while at pH < 4.7, PAW only required a shorter t _e to achieve complete sterilization, but its acidic environment could cause some chemical damage to the teeth. This study can provide some reference value for plasma treatment of dental caries.
Humans ; Streptococcus mutans ; Dental Caries/therapy* ; Sterilization ; Temperature ; Water

OBJECTIVE: To study the effectiveness and feasibility of cryogenic disinfectants in different cold scenarios and analyze the key points of on-site cryogenic disinfection. METHODS: Qingdao and Suifenhe were selected as application sites for the manual or mechanical spraying of cryogenic disinfectants. The same amount of disinfectant (3,000 mg/L) was applied on cold chain food packaging, cold chain containers, transport vehicles, alpine environments, and article surfaces. The killing log value of the cryogenic disinfectant against the indicator microorganisms ( Staphylococcus aureus and Escherichia coli) was used to evaluate the on-site disinfection effect. RESULTS: When using 3,000 mg/L with an action time of 10 min on the ground in alpine regions, the surface of frozen items, cold-chain containers, and cold chain food packaging in supermarkets, all external surfaces were successfully disinfected, with a pass rate of 100%. The disinfection pass rates for cold chain food packaging and cold chain transport vehicles of centralized supervised warehouses and food processing enterprises were 12.5% (15/120), 81.67% (49/60), and 93.33% (14/15), respectively; yet, the surfaces were not fully sprayed. CONCLUSION Cryogenic disinfectants are effective in disinfecting alpine environments and the outer packaging of frozen items. The application of cryogenic disinfectants should be regulated to ensure that they cover all surfaces of the disinfected object, thus ensuring effective cryogenic disinfection.
Humans ; Disinfectants/pharmacology* ; Disinfection ; Escherichia coli ; Staphylococcal Infections ; Staphylococcus aureus

Decontamination ; Disinfection ; Manikins ; Protective Clothing ; Personal Protective Equipment ; Health Personnel

Experimental model of Pseudomonas aeruginosa biofilm was established in vitro by using biofilm reactor. The aim of this study was evaluating the removal effect of two kinds of water flowing through bactericide resin on Pseudomonas aeruginosa biofilm, and exploring the effectiveness of continuous treatment with low concentration disinfection factor on dental unit waterlines. The experimental group selected 1-2 mg/L iodinated resin (IR) filtered water and bromined hydantoin resin (BHR) filtered water with the control group selecting the sterile distilled water. Biofilms were treated by using the immersion method for 3, 7, 10, 20, and 40 days. Total viable count (TVC) and laser confocal microscopy method (CLSM) were selected to evaluate the biofilm removal effect. The result of TVC showed that in group IR, the bacterial clearance after the treatment of 3, 7, 10, and 20 days was lower than 99.9% and unqualified. The bacterial clearance after the treatment of 40 days was 99.9%,which is qualified. In group BHR, it was lower than 99.9% and unqualified after the treatment of 3, 7, and 10 days. It was and 99.99%, 100.00% after the treatment of 20, 40 days, respectively. The result of CLSM showed that before treatment, Pseudomonas aeruginosa biofilm showed a sheet and mass distribution. The bacterial coverage was 19.24%±1.97%. The proportion of viable bacteria was 93.91%±1.39%, and the biofilm matrix coverage was 17.69%±1.11%. After 20 days of treatment, the biofilm was decreased in the IR group, with the biofilm bacterial coverage reducing to 6.77%±1.61%, the proportion of live bacteria reducing to 54.85%±5.65%, and the biofilm matrix coverage reducing to 2.41%±0.85%.There was significant difference from the pre-treatment and the control (F=359.996,P<0.001). No biofilm-like structure was found in the BHR group. After 40 days of treatment, there was still a small amount of biofilm matrix residue in the IR group, with no bacterial coverage observed. The biofilm matrix coverage was 0.67%±0.47% (F=1 021.373,P<0.001). No biofilm-like structure was found in the BHR group. In conclusion, the continuous application of BHR filter water has more advantages in killing microorganisms in biofilms, removing live and dead bacteria and biofilm matrix in biofilms. Treatment water containing corresponding low concentration disinfection factors can play an important role in the field of biofilm control in dental unit waterlines.
Humans ; Disinfection/methods* ; Pseudomonas aeruginosa ; Biofilms ; Water/pharmacology*

Experimental model of Pseudomonas aeruginosa biofilm was established in vitro by using biofilm reactor. The aim of this study was evaluating the removal effect of two kinds of water flowing through bactericide resin on Pseudomonas aeruginosa biofilm, and exploring the effectiveness of continuous treatment with low concentration disinfection factor on dental unit waterlines. The experimental group selected 1-2 mg/L iodinated resin (IR) filtered water and bromined hydantoin resin (BHR) filtered water with the control group selecting the sterile distilled water. Biofilms were treated by using the immersion method for 3, 7, 10, 20, and 40 days. Total viable count (TVC) and laser confocal microscopy method (CLSM) were selected to evaluate the biofilm removal effect. The result of TVC showed that in group IR, the bacterial clearance after the treatment of 3, 7, 10, and 20 days was lower than 99.9% and unqualified. The bacterial clearance after the treatment of 40 days was 99.9%,which is qualified. In group BHR, it was lower than 99.9% and unqualified after the treatment of 3, 7, and 10 days. It was and 99.99%, 100.00% after the treatment of 20, 40 days, respectively. The result of CLSM showed that before treatment, Pseudomonas aeruginosa biofilm showed a sheet and mass distribution. The bacterial coverage was 19.24%±1.97%. The proportion of viable bacteria was 93.91%±1.39%, and the biofilm matrix coverage was 17.69%±1.11%. After 20 days of treatment, the biofilm was decreased in the IR group, with the biofilm bacterial coverage reducing to 6.77%±1.61%, the proportion of live bacteria reducing to 54.85%±5.65%, and the biofilm matrix coverage reducing to 2.41%±0.85%.There was significant difference from the pre-treatment and the control (F=359.996,P<0.001). No biofilm-like structure was found in the BHR group. After 40 days of treatment, there was still a small amount of biofilm matrix residue in the IR group, with no bacterial coverage observed. The biofilm matrix coverage was 0.67%±0.47% (F=1 021.373,P<0.001). No biofilm-like structure was found in the BHR group. In conclusion, the continuous application of BHR filter water has more advantages in killing microorganisms in biofilms, removing live and dead bacteria and biofilm matrix in biofilms. Treatment water containing corresponding low concentration disinfection factors can play an important role in the field of biofilm control in dental unit waterlines.
Humans ; Disinfection/methods* ; Pseudomonas aeruginosa ; Biofilms ; Water/pharmacology*

OBJECTIVE: To investigate the baseline levels of microorganisms' growth on the hands of anesthesiologists and in the anesthesia environment at a cancer hospital. METHODS: This study performed in nine operating rooms and among 25 anesthesiologists at a cancer hospital. Sampling of the hands of anesthesiologists and the anesthesia environment was performed at a ready-to-use operating room before patient contact began and after decontamination. RESULTS: Microorganisms' growth results showed that 20% (5/25) of anesthesiologists' hands carried microorganisms (> 10 CFU/cm ²) before patient contact began. Female anesthesiologists performed hand hygiene better than did their male counterparts, with fewer CFUs ( P = 0.0069) and fewer species ( P = 0.0202). Our study also found that 55.6% (5/9) of ready-to-use operating rooms carried microorganisms (> 5 CFU/cm ²). Microorganisms regrowth began quickly (1 hour) after disinfection, and increased gradually over time, reaching the threshold at 4 hours after disinfection. Staphylococcus aureus was isolated from the hands of 20% (5/25) of anesthesiologists and 33.3% (3/9) of operating rooms. CONCLUSION Our study indicates that male anesthesiologists need to pay more attention to the standard operating procedures and effect evaluation of hand hygiene, daily cleaning rate of the operating room may be insufficient, and we would suggest that there should be a repeat cleaning every four hours.
Female ; Humans ; Male ; Anesthesia ; Anesthesiologists/statistics & numerical data* ; Disinfection/standards* ; Hand Hygiene/statistics & numerical data* ; Staphylococcal Infections ; Operating Rooms/statistics & numerical data* ; Staphylococcus aureus/isolation & purification*

Disinfection ; Research ; Mass Screening

This study briefly introduces the basic theory of sterilization, the characteristics of ethylene oxide sterilization for medical devices and the key factors about sterilization effectiveness, analyzes and compares three methods used in the product release of medical devices sterilized by ethylene oxide: test for sterility, traditional release and parametric release, and focuses on the theoretical basis, feasibility, validation requirements, advantages and disadvantages of parametric release.
Ethylene Oxide ; Sterilization/methods*

Purpose: This study aims to compare surgical scrubbing with and without a brush in decreasing the number of germ colonies on hands. Background: Surgical scrubbing with and without a brush are currently popular worldwide. To date, the optimal method in decreasing the number of germ colonies on the hands is not known. Methods: Systematic review of effectiveness was conducted. The databases and publisher websites included PubMed, Science Direct, Google Scholar, Wiley Online Library, Cochrane Library and recruitment studies published between 2009-2019. The risk of bias was assessed utilizing Cochrane Collaboration's tool. Results: Included clinical studies consisting of five randomized controlled trials. The procedures and duration of surgical scrubbing on each study varied depending on the protocol as a reference. All clinical studies found no difference in the number of colonyforming units (CFU) on the hand between surgical scrubbing with and without a brush. Conclusions Scrubbing with and without a brush showed similar efficacy in terms of the number of germ colonies on the hands.
Hand Disinfection

BACKGROUND: Public perceptions and personal characteristics are heterogeneous between countries and subgroups, which may have different impacts on health-protective behaviors during the coronavirus disease 2019 (COVID-19) pandemic. To assess whether self-reported perceptions of COVID-19 and personal characteristics are associated with protective behaviors among general adults and to compare patterns in six different countries. METHODS: This cross-sectional study uses the secondary data collected through an online survey between 15 and 23 April 2020 across six countries (China, Italy, Japan, Korea, the UK, and the USA). A total of 5945 adults aged 18 years or older were eligible for our analysis. A logistic regression model was used to estimate odds ratios (OR) and 95% confidence intervals (95%CI) of three recommended behaviors (wearing a mask, handwashing, and avoiding social gatherings). RESULTS: In most countries except for China, the participants who perceived wearing a mask as being extremely effective to curtail the pandemic were more likely to wear a mask (OR, 95%CI: Italy: 4.14, 2.08-8.02; Japan: 3.59, 1.75-7.30; Korea: 7.89, 1.91-31.63: UK: 9.23, 5.14-17.31; USA: 4.81, 2.61-8.92). Those who perceived that handwashing was extremely effective had higher ORs of this preventive behavior (OR, 95%CI: Italy: 16.39, 3.56-70.18; Japan: 12.24, 4.03-37.35; Korea: 12.41, 2.02-76.39; UK: 18.04, 2.60-152.78; USA: 10.56, 2.21-44.32). The participants who perceived avoiding social gathering as being extremely effective to curtail the pandemic were more likely to take this type of preventive behavior (OR, 95%CI: China: 3.79, 1.28-10.23; Korea: 6.18, 1.77-20.60; UK: 4.45, 1.63-11.63; USA: 4.34, 1.84-9.95). The associations between personal characteristics, living environment, psychological status, and preventive behaviors varied across different countries. Individuals who changed their behavior because of recommendations from doctors/public health officials were more likely to take preventive behaviors in many countries. CONCLUSIONS These findings suggest that higher perceived effectiveness may be a common factor to encourage preventive behaviors in response to the COVID-19 pandemic. These results may provide a better understanding of the homogeneity and heterogeneity of factors related to preventive behaviors and improve public health policies in various countries and groups.
Adolescent ; Adult ; Aged ; Attitude to Health ; COVID-19/psychology* ; Cross-Sectional Studies ; Female ; Hand Disinfection ; Health Behavior ; Humans ; Male ; Masks ; Middle Aged ; Physical Distancing ; SARS-CoV-2 ; Self Report ; Social Conformity ; Young Adult