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*

Severe cases infected with the coronavirus disease 2019 (COVID-19), named by the World Health Organization (WHO) on Feb. 11, 2020, tend to present a hypercatabolic state because of severe systemic consumption, and are susceptible to stress ulcers and even life-threatening gastrointestinal bleeding. Endoscopic diagnosis and treatment constitute an irreplaceable part in the handling of severe COVID-19 cases. Endoscopes, as reusable precision instruments with complicated structures, require more techniques than other medical devices in cleaning, disinfection, sterilization, and other reprocessing procedures. From 2016 to 2019, health care-acquired infection caused by improper endoscope reprocessing has always been among the top 5 on the list of top 10 health technology hazards issued by the Emergency Care Research Institute. Considering the highly infective nature of COVID-19 and the potential aerosol contamination therefrom, it is of pivotal significance to ensure that endoscopes are strictly reprocessed between uses. In accordance with the national standard "Regulation for Cleaning and Disinfection Technique of Flexible Endoscope (WS507-2016)," we improved the workflow of endoscope reprocessing including the selection of chemicals in an effort to ensure quality control throughout the clinical management towards COVID-19 patients. Based on the experience we attained from the 12 severe COVID-19 cases in our hospital who underwent endoscopy 23 times in total, the article provides an improved version of endoscopic reprocessing guidelines for bedside endoscopic diagnosis and treatment on COVID-19 patients for reference.
Adult ; Aged ; Aged, 80 and over ; Betacoronavirus ; China ; Coronavirus Infections ; diagnosis ; therapy ; Cross Infection ; prevention & control ; Disinfection ; methods ; Endoscopes ; virology ; Equipment Contamination ; prevention & control ; Female ; Humans ; Male ; Middle Aged ; Pandemics ; Peracetic Acid ; Personal Protective Equipment ; Pneumonia, Viral ; diagnosis ; therapy ; Sterilization ; methods ; Workflow

Academic Medical Centers ; COVID-19/prevention & control* ; Cross Infection/prevention & control* ; Disinfection ; Hospitals, Isolation ; Humans ; Infection Control/methods* ; Infectious Disease Transmission, Patient-to-Professional/prevention & control* ; Radiology ; Radiology Department, Hospital/organization & administration* ; SARS-CoV-2 ; Singapore

COVID-19 Nucleic Acid Testing/methods* ; Clinical Laboratory Techniques ; Containment of Biohazards ; Disinfection ; Environmental Monitoring ; Humans ; Nucleic Acids/isolation & purification* ; SARS-CoV-2/isolation & purification* ; Specimen Handling

OBJECTIVES: Irrigants are imperative in endodontic therapy for the elimination of pathogens from the infected root canal. The present study compared the antimicrobial efficacy of octenidine dihydrochloride (OCT) with chlorhexidine (CHX) and sodium hypochlorite (NaOCl) against Staphylococcus epidermidis (S. epidermidis) for root canal disinfection. MATERIALS AND METHODS: The minimum inhibitory concentration (MIC) was obtained using serial dilution method. The agar diffusion method was then used to determine the zones of inhibition for each irrigant. Lastly, forty 6-mm dentin blocks were prepared from human mandibular premolars and inoculated with S. epidermidis. Samples were randomly divided into 4 groups of 10 blocks and irrigated for 3 minutes with saline (control), 2% CHX, 3% NaOCl, or 0.1% OCT. Dentin samples were then collected immediately for microbial analysis, including an analysis of colony-forming units (CFUs). RESULTS: The MICs of each tested irrigant were 0.05% for CHX, 0.25% for NaOCl, and 0.0125% for OCT. All tested irrigants showed concentration-dependent increase in zones of inhibition, and 3% NaOCl showed the largest zone of inhibition amongst all tested irrigants (p < 0.05). There were no significant differences among the CFU measurements of 2% CHX, 3% NaOCl, and 0.1% OCT showing complete elimination of S. epidermidis in all samples. CONCLUSIONS: This study showed that OCT was comparable to or even more effective than CHX and NaOCl, demonstrating antimicrobial activity at low concentrations against S. epidermidis.
Agar ; Anti-Bacterial Agents ; Bicuspid ; Chlorhexidine ; Dental Pulp Cavity ; Dentin ; Diffusion ; Disinfection ; Humans ; In Vitro Techniques ; Methods ; Microbial Sensitivity Tests ; Sodium Hypochlorite ; Staphylococcus epidermidis ; Staphylococcus ; Stem Cells

PURPOSE: Although dental impression disinfection is determinant to reduce the cross-infection risk, some studies have shown that, in real practice, the disinfection procedures vary considerably. Thus, the aim of this study was to evaluate the antimicrobial effectiveness and the impact on the dimensional stability of addition silicone' impressions of water wash and the most clinically used disinfection solutions: 3% hydrogen peroxide, commercial disinfectant MD520 (Durr) and 1% and 5.25% sodium hypochlorite. MATERIALS AND METHODS: For this investigation, dental impressions were taken on 16 volunteer dental students. The antimicrobial effectiveness of each procedure was evaluated by pour plate method. The dimensional stability was evaluated using a standardized stainless-steel model, according to ANSI/ADA nº19 specification. RESULTS: The study results showed that water wash does not alter the dimensional stability of addition silicone impressions but doesn't reduce the microbial load of the material (P>.05). On the other hand, addition silicone disinfection by immersion with 3% hydrogen peroxide, MD520 (Durr), or sodium hypochlorite at 1% and 5.25% does not alter the dimensional stability significantly but reduces > 99.9% of the microbial load of the impressions (P<.001). CONCLUSION: Addition silicone impressions should always be disinfected after water wash in order to reduce effectively the cross-infection risk. All disinfectants tested showed high antimicrobial efficiency without significant changes in three-dimensional shape of impressions. Hydrogen peroxide and sodium hypochlorite are of particular importance because are easily accessible in dental setting. The less explored hydrogen peroxide could be a valuable alternative for silicone impressions disinfection.
Disinfectants ; Disinfection ; Hand ; Humans ; Hydrogen Peroxide ; Immersion ; Methods ; Silicon ; Silicone Elastomers ; Silicones ; Sodium Hypochlorite ; Students, Dental ; Volunteers ; Water

The most common cause of antibiotic-associated diarrhea is Clostridium difficile infection (CDI). Recurrent C. difficile infection (rCDI) often occurs after successful treatment of CDI. Due to the increased incidence and the difficulty in treating rCDI, it is becoming an important clinical issue. Identifying risk factors is helpful for early detection, treatment, and prevention of rCDI. Advanced age, use of antibiotics, gastric acid suppression, and infection with a hypervirulent strain are currently regarded as the major risk factors for rCDI. Several treatment modalities, including vancomycin, fidaxomicin, and fecal microbiota transplant (FMT), are suggested for rCDI treatment. However, there is currently no definitive treatment method with sufficient evidence for rCDI. Recent studies have focused on FMT and have shown positive results for rCDI. Prevention of rCDI by measures such as hand washing and isolation of patients is very important. However, these preventive measures are often overlooked in clinical practice. Here, we review the risk factors, treatment, and prevention of rCDI.
Anti-Bacterial Agents ; Clostridium difficile* ; Clostridium* ; Diarrhea ; Gastric Acid ; Hand Disinfection ; Humans ; Incidence ; Methods ; Microbiota ; Recurrence ; Risk Factors* ; Vancomycin

We studied the disinfection effect of a new ultraviolet (UV) sterilizer and its utilization on ultrasound probe surfaces. Carrier quantitative germicidal tests, simulated on-the-spot trials, and organic substance influence tests were used to carry out experimental observation. Artificially infected probes were disinfected using the sterilizer or a germicidal lamp for comparison. The total number and types of bacteria were determined and identified. Our results demonstrated the sterilizer had the best disinfection effect among three different disinfection methods in hospital. The sterilizer has been used in a hospital setting for 2 years with no notable damage to the ultrasound probe instrument. It has the advantages of fast disinfection, high disinfection effect, and good compatibility with the ultrasound instrument, worthy of being a promoted application in medical institutions.
Bacterial Infections ; microbiology ; prevention & control ; Colony Count, Microbial ; Cross Infection ; microbiology ; prevention & control ; Disinfection ; instrumentation ; methods ; Equipment Contamination ; prevention & control ; Sterilization ; instrumentation ; Surface Properties ; Ultrasonography ; instrumentation ; Ultraviolet Rays

ObjectiveTo study the influence of povidone-iodine (PI) versus that of the benzethonium chloride wipe (BCW) on semen collection and semen quality of sperm donors undergoing penile skin disinfection and provide some evidence for the selection of disinfection methods for semen collection.

METHODSWe used PI from August to December 2015 and BCWs from January to July 2016 for penile skin disinfection before semen collection, with two samples from each donor, one collected with and the other without penis skin disinfection (the blank control group). After semen collection, we conducted a questionnaire investigation on the influence of the two disinfection methods on semen collection and compared the semen parameters between the two groups of sperm donors.

RESULTSTotally, 185 sperm donors were included in this study, of whom 63 underwent penile skin disinfection with PI and the other 122 with BCWs before semen collection. Statistically significant differences were found between the PI and BCW groups in the adaptability to the disinfectant and rigid disinfection procedures (P <0.05), but not in the other items of the questionnaire (P >0.05). Compared with the sperm donors of the blank control group, those of the PI group showed statistically significant difference in the percentage of progressively motile sperm (PMS) (［63.02 ± 3.18］% vs ［61.45 ± 4.78］%, P<0.05), but not in the abstinence time (［4.97 ± 1.79］ vs ［4.7 ± 0.94］ d, P >0.05), semen volume (［4.11 ± 1.54］ vs ［4.15 ± 1.61］ ml, P >0.05), sperm concentration (［110 ± 29.6］ vs ［107.5 ± 31.79］ ×10⁶/ml, P >0.05), or total sperm count (［439.10 ± 170.13］ vs ［434.02 ± 186.91］ ×106/ejaculate, P >0.05), while those of the BCW group exhibited no remarkable difference in any of the above parameters (P >0.05). Among the samples with abnormal semen quality, significantly fewer were found with abnormal PMS in the BCW than in the PI group (1.64% ［2/122］ vs 9.68% ［6/62］, P <0.05). However, there were no significant differences between the PI and BCW groups in the abnormal semen volume, abnormal sperm concentration, or the rate of semen bacterial contamination (P >0.05).

CONCLUSIONSBefore semen collection from donors, penile skin disinfection with povidone-iodine may affect both the semen collection process and the quality of donor sperm, while the benzethonium chloride wipe can reduce the influence on the semen collection process and does not affect the semen parameters.

Anti-Infective Agents, Local ; administration & dosage ; Benzethonium ; administration & dosage ; Disinfection ; methods ; statistics & numerical data ; Humans ; Male ; Penis ; Povidone-Iodine ; administration & dosage ; Semen ; Semen Analysis ; Skin ; Sperm Count ; Sperm Retrieval ; Spermatozoa ; Tissue Donors