A prototype for on-site generation of chlorinated disinfectant for use in rural aqueducts

Sodium hypochlorite has significant potential as a sanitation solution in hard-to-reach areas.Few studies have investigated the optimal electrolysis parameters for its production with volumes greater than 1o L.This study evaluated sodium hypochlorite production through electrolysis in a 22-L prototype and identified the optimal operating parameters.Tests were performed using graphite electrodes with areas of 68.4 cm^(2) at the laboratory scale and 1865.0 cm^(2) at the prototype scale.A design for experiments with different operating times,chloride concentrations,and electric current intensities was developed.The optimal operating time,sodium chloride concentration,and current intensity at the laboratory scale were 120 min,150 g of chloride per liter,and 3 A,respectively,leading to the production of 5.02 g/L of the disinfectant with an energy efficiency of 12.21 mg of Cl_(2) per kilojoule.At the prototype scale,the maximum sodium hypochlorite concentration of 3.99 g of chloride per liter was achieved with an operating time of 120 min,a sodium chloride concentration of 100 g of chloride per liter,and a current intensity of 70 A,reaching an energy efficiency of 42.56 mg of Cl_(2) per kilojoule.In addition,this study evaluated the influences of the chloride concentration,current intensity,and operating time on the production of sodium hypochlorite at the two scales,and formulated the equations showing the trends of sodium hypochlorite production and energy efficiency in the electrochemical systems.The 22-L prototype model for production of this oxidizing substance is promising for disinfection of large volumes of water in areas that are difficult to access.

Estimating shear strength of high-level pillars supported with cemented backfilling using the HoekeBrown strength criterion

Deep metal mines are often mined using the high-level pillars with subsequent cementation backfilling(HLSCB)mining method.At the design stage,it is therefore important to have a reasonable method for determining the shear strength of the high-level pillars(i.e.cohesion and internal friction angle)when they are supported by cemented backfilling.In this study,a formula was derived for the upper limit of the confining pressure σ3max on a high-level pillar supported by cemented backfilling in a deep metal mine.A new method of estimating the shear strength of such pillars was then proposed based on the Hoek eBrown failure criterion.Our analysis indicates that the horizontal stress σhh acting on the cemented backfill pillar can be simplified by expressing it as a constant value.A reasonable and effective value for σ3max can then be determined.The value of s3max predicted using the proposed method is generally less than 3 MPa.Within this range,the shear strength of the high-level pillar is accurately calculated using the equivalent MohreCoulomb theory.The proposed method can effectively avoid the calculation of inaccurate shear strength values for the high-level pillars when the original HoekeBrown criterion is used in the presence of large confining pressures,i.e.the situation in which the cohesion value is too large and the friction angle is too small can effectively be avoided.The proposed method is applied to a deep metal mine in China that is being excavated using the HLSCB method.The shear strength parameters of the high-level pillars obtained using the proposed method were input in the numerical simulations.The numerical results show that the recommended level heights and sizes of the high-level pillars and rooms in the mine are rational.

On-Site Assessment of a Cryogenic Disinfectant for the Alpine Environment and Outer Packaging of Frozen Items

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.

Corrosion Behaviors of Disinfectants on Dental Unit Waterlines

To investigate the corrosion behaviors and antibacterial effects of sodium hypochlorite(NaClO)and hydrogen peroxide silver ion(HPSI)disinfectants with different concentrations against dental unit waterlines and provide guidance and reference for the use of chemical disinfectants,polyurethane tubes were immersed in ultrapure water(control group),0.1%NaClO,0.5%NaClO,1.0%NaClO,2.5%HPSI,5.0%HPSI,and 10%HPSI solutions for 6,12,and 18 weeks.Contact angles and Fourier transform infrared spectra were detected.Surface morphologies were observed using scanning electron microscopy and antibacterial activity was evaluated using Gram-positive Staphylococcus aureus(S.aureus).The results showed that sodium hypochlorite and hydrogen peroxide silver ion disinfectants presented good antibacterial activity against S.aureus.However,sodium hypochlorite could cause serious damage to the water pipes where corrosion pits and cracks were observed,and increasing the concentration of sodium hypochlorite could accelerate the corrosion process.Hydrogen peroxide silver ion disinfectants had no obvious damage to the water pipes.Therefore,hydrogen peroxide silver ion disinfectants are recommended to use for controlling bacterial infection in dental unit waterlines which can reduce the damage to the water pipes.

Disinfection Byproducts and Their Precursors in Drinking Water Sources:Origins,Influencing Factors,and Environmental Insights

Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health.However,current analysis approaches are not ideal,as they tend to be laborious,time-consuming,or technically difficult.Disinfection byproducts(DBPs)are a family of well-known secondary pollutants formed by the reactions of chemical disinfectants with DBP precursors during water disinfection treatment.Since DBP precursors have various origins(e.g.,natural,domestic,industrial,and agricultural sources),and since the formation of DBPs from different precursors in the presence of specific disinfectants is distinctive,we argue that DBPs and DBP precursors can serve as alternative indicators to assess the contamination in water sources and identify pollution origins.After providing a retrospective of the origins of DBPs and DBP precursors,as well as the specific formation patterns of DBPs from different precursors,this article presents an overview of the impacts of various natural and anthropogenic factors on DBPs and DBP precursors in drinking water sources.In practice,the DBPs(i.e.,their concentration and speciation)originally present in source water and the DBP precursors determined using DBP formation potential tests—in which water samples are dosed with a stoichiometric excess of specific disinfectants in order to maximize DBP formation under certain reaction conditions—can be considered as alternative metrics.When jointly used with other water quality parameters(e.g.,dissolved organic carbon,dissolved organic nitrogen,fluorescence,and molecular weight distribution)and specific contaminants of emerging concern(e.g.,certain pharmaceuticals and personal care products),DBPs and DBP precursors in drinking water sources can provide a more comprehensive picture of water pollution for better managing water resources and ensuring human health.

Efficacy of graphene nanocomposites for air disinfection in dental clinics: A randomized controlled study

BACKGROUND Aerosols containing disease-causing microorganisms are produced during oral diagnosis and treatment can cause secondary contamination.AIM To investigate the use of graphene material for air disinfection in dental clinics by leveraging its adsorption and antibacterial properties.METHODS Patients who received ultrasonic cleaning at our hospital from April 2023 to April 2024.They were randomly assigned to three groups(n=20 each):Graphene nanocomposite material suction group(Group A),ordinary filter suction group(Group B),and no air suction device group(Group C).The air quality and air colony count in the clinic rooms were assessed before,during,and after the procedure.Additionally,bacterial colony counts were obtained from the air outlets of the suction devices and the filter screens in Groups A and B.RESULTS Before ultrasonic cleaning,no significant differences in air quality PM2.5 and colony counts were observed among the three groups.However,significant differences in air quality PM2.5 and colony counts were noted among the three groups during ultrasonic cleaning and after ultrasonic treatment.Additionally,the number of colonies on the exhaust port of the suction device and the surface of the filter were significantly lower in Group A than in Group B(P=0.000 and P=0.000,respectively).CONCLUSION Graphene nanocomposites can effectively sterilize the air in dental clinics by exerting their antimicrobial effects and may be used to reduce secondary pollution.

Effect of Different Disinfection Methods on Calluses of Amorphophallus albus P.Y.Liu&J.F.Chen

This study aimed to examine the effect of different disinfection methods on the callus of Amorphophallus albus in the tissue culture and rapid propagation system.The calluses induced from buds of A.albus were disinfected with benzalkonium bromide,mercury bichloride,sodium hypochlorite,and ethanol,respectively,for different time periods.The growth of calluses was compared between different treatments and observed in detail by dissection.The results showed that the disinfection with 0.1% mercury bichloride for 5 min and 75% ethanol for 5 s had mild effect on the callus,with the lowest browning rates of 16.32% and 15.46% and the lowest vitrification rates of 3.24% and 9.72%,respectively,after 20 d.The disinfection with benzalkonium bromide and sodium hypochlorite had strong effect on the callus cells,with the lowest browning rate of 50.69% and 25.12% and the lowest vitrification rates of 28.47% and 28.43%,respectively.The cytological observation result showed that the calluses disinfected with ethanol and mercury bichloride showcased compact structures,while those disinfected with sodium hypochlorite and benzalkonium bromide exhibited loose structures.To sum up,it is recommended that 75% ethanol or 0.1% mercury bichloride can be used for disinfection in the tissue culture and rapid propagation of A.albus,while the use of benzalkonium bromide and sodium hypochlorite should be avoided as much as possible.

Evaluation of the Impact of Refined Quality Control Management Model on the Qualified Rate of Disinfection and Sterilization of Surgical Instruments in the Sterilization Supply Center

Objective:To evaluate the application value of a refined quality control management model for a sterilization supply center.Methods:A retrospective analysis was conducted on the work situation of the sterilization supply center from January 2021 to January 2023.The work situation before January 31,2022,was classified as the control group;a routine quality control management model was implemented,and the work situation after January 31,2022,was classified as the observation group.The quality of medical device management and department satisfaction between the two groups were compared.Results:The timely recovery and supply rate,classification and cleaning pass rate,disinfection pass rate,packaging pass rate,sterilization pass rate,and department satisfaction score in the observation group were all higher than those of the control group(P<0.05).Conclusion:Implementing a refined quality control management model in the sterilization supply center can improve the quality management level of medical devices and department satisfaction and is worthy of promotion.

Double enzyme mimetic activities of multifunctional Ag nanoparticle-decorated Co_(3)V_(2)O_(8)hollow hexagonal prismatic pencils for application in colorimetric sensors and disinfection

Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes,there is urgent need to discover novel highly efficient enzyme-like materials.In this work,Co_(3)V_(2)O_(8)with hollow hexagonal prismatic pencil structures were prepared as novel artificial enzyme mimics.They were then decorated by photo-depositing Ag nanoparticles(Ag NPs)on the surface to further improve its catalytic activities.The Ag NPs decorated Co_(3)V_(2)O_(8)(ACVPs)showed both excellent oxidase-and peroxidase-like catalytic activities.They can oxidize the colorless 3,3’,5,5’-tetramethylbenzidine rapidly to induce a blue change.The enhanced enzyme mimetic activities can be attributed to the surface plasma resonance(SPR)effect of Ag NPs as well as the synergistic catalytic effect between Ag NPs and Co_(3)V_(2)O_(8),accelerating electron transfer and promoting the catalytic process.ACVPs were applied in constructing a colorimetric sensor,validating the occurrence of the Fenton reaction,and disinfection,presenting favorable catalytic performance.The enzyme-like catalytic mechanism was studied,indicating the chief role of⋅O_(2)-radicals in the catalytic process.This work not only discovers a novel functional material with double enzyme mimetic activity but also provides a new insight into exploiting artificial enzyme mimics with highly efficient catalytic ability.

Curative effect of hydrogen peroxide combined with silver ion disinfection on pelvic floor dysfunction

BACKGROUND Pelvic floor dysfunction(PFD)is related to muscle fiber tearing during childbirth,negatively impacting postpartum quality of life of parturient.Appropriate and effective intervention is necessary to promote PFD recovery.AIM To analyze the use of hydrogen peroxide and silver ion disinfection for vaginal electrodes in conjunction with comprehensive rehabilitation therapy for postpartum women with PFD.METHODS A total of 59 women with PFD who were admitted to the hospital from May 2019 to July 2022 were divided into two groups:Control group(n=27)received comprehensive rehabilitation therapy and observation group(n=32)received intervention with pelvic floor biostimulation feedback instrument in addition to comprehensive rehabilitation therapy.The vaginal electrodes were disinfected with hydrogen peroxide and silver ion before treatment.Intervention for both groups was started 6 weeks postpartum,and rehabilitation lasted for 3 months.Pelvic floor muscle voltage,pelvic floor muscle strength,vaginal muscle voltage,vaginal muscle tone,pelvic floor function,quality of life,and incidence of postpartum PFD were compared between the two groups.RESULTS Before comprehensive rehabilitation treatment,basic data and pelvic floor function were not significantly different between the two groups.After treatment,the observation group showed significant improvements in the maximum voltage and average voltage of pelvic floor muscles,contraction time of type I and type II fibers,pelvic floor muscle strength,vaginal muscle tone,vaginal muscle voltage,and quality of life(GQOLI-74 reports),compared with the control group.The observation group had lower scores on the pelvic floor distress inventory(PFDI-20)and a lower incidence of postpartum PFD,indicating the effectiveness of the pelvic floor biostimulation feedback instrument in promoting the recovery of maternal pelvic floor function.CONCLUSION The combination of the pelvic floor biostimulation feedback instrument and comprehensive rehabilitation nursing can improve pelvic floor muscle strength,promote the recovery of vaginal muscle tone,and improve pelvic floor function and quality of life.The use of hydrogen peroxide and silver ion disinfectant demonstrated favorable antibacterial efficacy and is worthy of clinical application.

Performance Parameters:Demobilization Antibiotic Resistant Bacteria(ARB)and Carrying Genes(ARG)in Wastewater Disinfection

The UV irradiation is used for removing Antibiotic Resistant Bacteria(ARB)and Antibiotic Resistance Genes(ARG)from wastewater treatment.Bacteriophages are viruses that infect within bacteria,are recognized for bacterial control.The influence of some parameters in quantification and performance influencing of pathogen demobilization could be considered in disinfection of wastewater.The comparison of Polyvalent phage(NE1)versus Coliphage(NE4)in suppressing a bacterium Escherichia coli(NDM-1:b-lactam-resistant)with UV irradiation was observed the efficacy in reduction of cells in the disinfection and parameter process.The results with the effect of UV-C irradiation on NDM-1 infected with 1%of NE4 showed a decrease of cells from 8×10^(6)to 2×10^(5)in 60 min with UV-C dose.The NDM1(E.coli)was infected with 1%of NE4(Polyvalent Phage)under magnetic stirring for 1 h,the cells count was 8×10^(6).After 1 h in UV-C e×posure,the cells number reached 3×10^(5).The NDM1 that was e×posed in 1 h of UV-C irradiation and then was infected with 1%of NE4.Cells counting were done 24 h after this procedure.These cells were e×posed in UV-C and showed a reduction in the number of cells from 1×10^(8)to 4×10^(5)after 60 min.The results indicate that bacteriophages can mitigate bacteria species,and combined the conventional water disinfection technologies that can support the microbial safety control strategies.

Research on the Path of Cultivating High-Level Technical and Skilled Talents in Vocational Undergraduate Colleges and Universities

This paper explores strategies to cultivate high-level technical talents in vocational undergraduate colleges by analyzing their development,the essence of such talents,and proposing several key measures.Strategies include optimizing professional settings and curricula,enhancing school-enterprise cooperation and the integration of industry-university-research,improving teaching staff quality and educational standards,and expanding international cooperation.The importance of policy support and funding and establishing robust quality assurance systems is emphasized for effectively cultivating skilled talents in vocational undergraduate colleges.

Progress in Analytical Methods of Halogenated Disinfection By-Products

Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become one of the significant advances in public health.However,the disinfectants used in the process,such as chlorine and chlorine dioxide,react with natural organic matter in the water to produce disinfection by-products(DBPs).Most of these DBPs contain chlorine,and if the source water contains bromine or iodine,brominated or iodinated DBPs,collectively referred to as Halogenated disinfection byproducts(X-DBPs),are formed.Numerous studies have found that X-DBPs pose potential risks to human health and the environment,leading to widespread concern.Mass spectrometry has become an important means of discovering new types of X-DBPs.This paper focuses on the study of methods for analyzing X-DBPs in drinking water using mass spectrometry.

Effects of Penicillium spp. and Trichoderma spp.on Pleurotus ostreatus Growth and Screening of Effective Disinfectants

[Objective] This study was conducted to investigate the effects of Penicillium spp. and Trichoderma spp. on the growth of Pleurotus ostreatus （oyster mushroom） and to screen effective disinfectants to control them and other pathogenic microbes. [Method] Six strains or species of Penicilliurn and Trichoderma were inocu- lated into PDA plates growing with P. ostreatus to observe the growth of their mycelia. And the inhibitory effects of hydrogen peroxide, bromogeramine bromide, 84 disinfectant, lysol, potassium permanganate, and 75% medical alcohol on Trichoderma pleuroticola, Trichoderma viride, Trichoderma harzianum, Penicillium citrinum, Penicillium thomii and Penicillium brevicompactum were detected. [Result] Confrontation test revealed that Penicillium spp. and Trichoderma spp. competed for nutrients with P. ostreatus mycelia, antagonized against the growth of P. ostreatus mycelia, invaded and twined around P. ostreatus mycelia, and also produced toxins poisoning P. ostreatus mycelia. The six disinfectants exhibited different inhibitory effects against different species of Penicillium and Trichoderma. Among them the in- hibitory effects of bromogeramine bromide against the six species of Penicillium and Trichoderma were significantly different. However, the inhibitory effects of 3% hydrogen peroxide, 84 disinfectant, 5% lysol, potassium permanganate and 75% medical alcohol were significantly different among Penicillium spp., but did not among Tri- choderma spp. [Conclusion] Bromogeramine bromide can be used to control the bacteria and fungi in mushroom production for it has significant inhibitory effects on the six species of both Penicillium and Trichoderma.

Is the Potential Interconnection between Antibiotic Susceptibility and Disinfectant Resistance a Threat to Food Safety?

The prevalence of antibiotic susceptibility and disinfectant resistance in bacterial pathogens causes a serious problem not only to food safety but also to public health, which directly or indirectly leads to treatment and disinfection failures. In this review, multidrug resistance, the mechanism of disinfectant resistance, the methods for detecting disinfectant resistance and the cross-resistance between an- tibiotics and disinfectants are summarized. More efforts should be devoted to explor- ing the professional guidance of using antibiotics and disinfectants, and to develop- ing the comprehensive detection with genetic and molecular methods is highly ex- pected.

High-level disinfection of gastrointestinal endoscope reprocessing

High level disinfection(HLD) of the gastrointestinal(GI)endoscope is not simply a slogan, but rather is a form of experimental monitoring-based medicine. By definition,GI endoscopy is a semicritical medical device. Hence,such medical devices require major quality assurance for disinfection. And because many of these items are temperature sensitive, low-temperature chemical methods, such as liquid chemical germicide, must be used rather than steam sterilization. In summarizing guidelines for infection prevention and control for GI endoscopy, there are three important steps that must be highlighted: manual washing, HLD with automated endoscope reprocessor, and drying. Strict adherence to current guidelines is required because compared to any other medical device, the GI endoscope is associated with more outbreaks linked to inadequate cleaning or disinfecting during HLD. Both experimental evaluation on the surveillance bacterial cultures and in-use clinical results have shown that, the monitoring of the stringent processes to prevent and control infection is an essential component of the broader strategy to ensure the delivery of safe endoscopy services, because endoscope reprocessing is a multistep procedure involving numerous factors that can interfere with its efficacy. Based on our years of experience in the surveillance of culture monitoring of endoscopic reprocessing, we aim in this study to carefully describe what details require attention in the GI endoscopy disinfection and to share our experience so that patients can be provided with high quality and safe medical practices. Quality management encompasses all aspects of pre- and postprocedural care including the efficiency of the endoscopy unit and reprocessing area, as well as the endoscopic procedure itself.

Swab culture monitoring of automated endoscope reprocessors after high-level disinfection

AIM:To conduct a bacterial culture study for monitoring decontamination of automated endoscope reprocessors(AERs) after high-level disinfection(HLD).METHODS:From February 2006 to January 2011,authors conducted randomized consecutive sampling each month for 7 AERs.Authors collected a total of 420 swab cultures,including 300 cultures from 5 gastroscope AERs,and 120 cultures from 2 colonoscope AERs.Swab cultures were obtained from the residual water from the AERs after a full reprocessing cycle.Samples were cultured to test for aerobic bacteria,anaerobic bacteria,and mycobacterium tuberculosis.RESULTS:The positive culture rate of the AERs was 2.0%(6/300) for gastroscope AERs and 0.8%(1/120) for colonoscope AERs.All the positive cultures,including 6 from gastroscope and 1 from colonoscope AERs,showed monofloral colonization.Of the gastroscopeAER samples,50%(3/6) were colonized by aerobic bacterial and 50%(3/6) by fungal contaminations.CONCLUSION:A full reprocessing cycle of an AER with HLD is adequate for disinfection of the machine.Swab culture is a useful method for monitoring AER decontamination after each reprocessing cycle.Fungal contamination of AERs after reprocessing should also be kept in mind.

Preparation and Evaluation of Novel Solid Chlorine Dioxide-based Disinfectant Powder in Single-pack

Objective To prepare and evaluate novel chlorine dioxide-based disinfectant powder in single-pack that is more convenient for use and transportation. Methods Orthogonal experiment was performed to determine the recipe of the disinfectant powder. Stability test, suspension quantitative bactericidal test, simulation field triM, and animal toxicity test were carded out to observe its bactericidal and toxicological effects. Results The orthogonal experiment showed that the type of water solution had no effect on the disinfectant powder and the best ratio of sodium chlorite to solid acid was 1：3. Ten grams of the disinfectant powder was fully dissolved in 20 mL water for 2 min, and diluted to 500 mL in water. After 5-10 min, the concentration of chlorine dioxide （CIO2） solution was 266 mg/L to 276 mg/L. After stored at 54℃ for 14 d, the average concentration of CIO2 was decreased by 5.03%. Suspension quantitative bactericidal test showed that the average killing logarithm （KL） value for both Staphylococcus aureus and Escherichia coli in 100 mg/L CIO2 solution for 2 min was over 5.00. In simulation field triM, the average descending KL value for Escherichia coli in the solution containing 100 mg/L CIO2 for 5 min was over 3.00. The mouse acute LD50 in the solution 5 times exceeded 5000 mg/kg. The disinfectant powder was not toxic and irritative to rabbit skin and had no mutagenic effect on mouse marrow polychromatic erythrocytes （PCE）. Conclusion The stability and bactericidal efficacy of solid chlorine dioxide-based disinfectant powder in single-pack are good. The solution containing 100 mg/L CIO2 can kill vegetative forms of bacteria. The concentration of CIO2 on the disinfecting surface of objects is 100 mg/L. The disinfectant powder is not toxic and irritative.

Enhanced Disinfection Effect of a Compound Disinfectant against Bovine Herpes Virus Type 1 at Low Temperature

A compound disinfectant, which consisted of didecyldimethylammonium chloride (DDAC), ortho-dichlorobenzene (1,2-dichlorobenzene, ODB), and chlorocresol (4-chloro-3-methylphenol, CC), and its component chemicals were individually tested for effectiveness against bovine herpes virus type 1 (BHV-1). DDAC, DDAC+ODB, DDAC+CC, and DDAC+ODB+CC showed effectiveness against BHV-1 at room temperature. However, ODB, CC, and ODB+CC showed no virucidal effects. The effects of all disinfectants tested were decreased at low temperature. DDAC showed disinfectant effects at a dilution of 1/800 and DDAC+ODB, DDAC+CC, and DDAC+ODB+CC at dilutions of 1/800 and 1/1600 at low temperature in the presence of 2% fetal bovine serum (FBS) but ODB, CC, and ODB+CC showed no virucidal effects. At low temperature and in the presence of 10% FBS, DDAC, DDAC+ODB, and DDAC+CC showed disinfectant effects at dilutions of 1/800, whereas ODB, CC, and ODB+CC showed no virucidal effects. DDAC+ ODB+CC was more effective (at 1/800 and 1/1600) than the other disinfectants under these conditions. In conclusion, a combination of three disinfectant components (DDAC+ODB+CC), enhanced the disinfectant effects at low temperature and in organic matter contamination.

Flashlight contamination and effectiveness of two disinfectants in a stomatology hospital

Aim: This study aims to assess the infection risks of flashlight contamination in a stomatology hospital and compare the disinfection effectiveness of alcohol (75%) and disinfecting wipes.Background: The flashlight is a basic non-critical medical device in oral and maxillofacial surgery wards. Wounds are mostly found in oral cavities;therefore, reusable flashlights may be a potential source of nosocomial infections (NIs). However, the microbial flora present in flashlights used in hospitals has not yet been explored. Methods: This study investigated the microbial contamination of 41 flashlights used in a stomatology hospital in Guangzhou in March 2016. Results: Results indicated that 75.6%(31/41) of the flashlights had microbial contamination. Gram-positive bacteria accounted for 72.7%(24/33)of the microbial groups contaminating the flashlights, and Gram-negative bacteria (21.2%, 7/33), and fungi (6.1%, 2/33) constituted the remaining contaminants. The predominantly isolated species was Staphyloccus (66.7%, 22/33), especially Staphylococcus aureus (24.2%, 8/33). Approximately 77.3%(17/22) of the types of bacteria detected in the hands were same as those in the corresponding flashlights. Both the bacterial overstandard and S. aureus detection rates of doctors' flashlights were higher than those of nurses' flashlights (16/17 vs. 14/23, 7/17 vs. 1/23, respectively) (P < 0.05). Moreover, both disinfectants performed excellently, and their eligibility rates were not significantly different (17/17 vs. 14/14) (P>0.05). Conclusion: Flashlights are potential causes of NIs. Disinfecting flashlights could be an effective and practical infection control method.