Disinfection Procedures Research Articles

Evaluation of temperature, drying time and other determinants for the recovery of Gram-negative bacterial pathogens in disinfectant efficacy testing

In the clinical setting, surface disinfection is an important measure to reduce the risk of cross-transmission of microorganisms and the risk of nosocomial infections. Standardized methods can be used to evaluate said disinfection procedures, as well as the effectiveness of the active ingredients used for disinfection. However, despite standardization, the results of such methodologies are still determined by several factors and incorrect results may lead to invalid assumptions about the effectiveness of a disinfectant, posing significant health risks for patients and health personnel. The objective of this study was to evaluate several determinants for the recovery of Pseudomonas aeruginosa and other test organisms to establish their influence on the results of standardized disinfection methodologies and to find Gram-negative strains that could be used as suitable replacements of P. aeruginosa. The effects of inoculum application, drying times and temperatures as well as surface material on the survival and recovery of the test organisms were evaluated using Student-T test, one-way ANOVA and Tuckey's multiple comparison tests. Our results show that temperature and length of drying as well as application method and the material of germ carriers have significant effects on the recovery of P. aeruginosa cells and therefore influence the outcome of the methodologies used. This study also presents data showing that P. aeruginosa could be replaced with the Gram-negative species Acinetobacter baumannii, a test organism already in many standardized methodologies, which responds better under the same circumstances and has a behavior similar to that of P. aeruginosa in disinfectant efficacy tests.

The Detection of Salmonella Enteritidis on German Layer Farms after Cleaning and Disinfection.

The presence of Salmonella Enteritidis in poultry houses after cleaning and disinfection can pose a potential risk to public health, as Salmonella remains one of the most important causes of foodborne diseases. This study focused on ten German layer farms (including floor-reared and free-range systems) with a recent history of Salmonella Enteritidis, and samples were collected from July 2018 to March 2021 after the cleaning and disinfection process. A total of 244 swab samples were tested for the presence of Salmonella using real-time PCR, followed by a culture of positive samples. Results revealed that 61 out of the 244 swab samples tested positive for Salmonella, indicating a prevalence of 25% in the samples examined. Among the Salmonella-positive swab samples identified with the PCR assay, 65.6% (40 out of 61) were confirmed by the culture. Of the 40 isolates obtained from the culture, 36 were identified as Salmonella Enteritidis, while 4 were categorized as rough Salmonella strains. This study emphasizes the importance of both the surrounding area of the poultry houses in terms of infection carry-over and the meticulous implementation of cleaning and disinfection procedures to eliminate any remaining infection within the houses. To mitigate the risk of further Salmonella spread on layer farms, additional investigations are recommended to focus on the existing transmission pathways of Salmonella and their genetic diversity.

How Does Epidemic Prevention Training for Pig Breeding Affect Cleaning and Disinfection Procedures Adoption? Evidence from Chinese Pig Farms.

African Swine Fever (ASF) is a highly infectious disease, severely affecting domestic pigs and wild boar. It has significantly contributed to economic losses within the pig farming industry. As a critical component of biosecurity measures, the selection of cleaning and disinfection (C&D) procedures is a dynamic and long-term decision that demands a deeper knowledge base among pig farmers. This study uses a binary logit model to explore the effect of epidemic prevention training on the adoption of C&D procedures among pig farmers with irregular and regular C&D procedures based on micro-survey data obtained from 333 pig farmers from Sichuan. The endogeneity issue was handled using propensity score matching, resulting in solid conclusions. In addition, the critical mediating impact of biosecurity cognition was investigated using a bootstrap analysis. The empirical study demonstrated that epidemic prevention training encourages pig farmers to adopt C&D procedures, with biosecurity cognition significantly mediating. Furthermore, epidemic prevention training was more likely to promote the adoption of C&D procedures among pig farmers with shorter breeding experiences and those having breeding insurance. Our study emphasized the importance of implementing epidemic prevention training to improving pig farmers' biosecurity cognition and promoting the adoption of C&D procedures. The results included suggested references for preventing ASF and the next epidemic of animal diseases.

Water Use and Water Saving Strategies in Dialysis, Room for Improvement?

Dialysis treatment consumes a significant amount of water and energy, which entails an important waste management effort. Those variables play a relevant role on the total cost of a dialysis session. Strict dialysis water and ultrapure dialysis fluids standards were established as a pre-requisite for online convective therapies (e.g., hemodiafiltration), improving biocompatibility of the dialysis system, reducing inflammation profile of the dialysis patients, enhancing the responsiveness to erythropoiesis-stimulating agents and thus having the potential for improved survival. The main purification step of a dialysis water treatment system is the reverse osmosis. Fouling of reverse osmosis membranes remains a major issue and all effort should be made to reduce it, to ensure a constant output. Naturally occurring waterborne filamentous fungi, yeasts, bacteria and fragments may contaminate dialysis water and, consequently, dialysis fluids. To maintain the dialysis water treatment system under proper conditions and fulfilling the dialysis fluids quality standards there is a need of a significant effort, namely in terms of cleaning and disinfection procedures of the reverse osmosis, distribution systems and dialysis machines. Improving the reverse osmosis inlet water quality profile by installing an Ultrafiltration system as a pre-treatment, could have an impact in terms of dialysis water quality outcomes, water and energy consumption, and disinfection frequency. The water treatment system efficiency is strongly influenced by the system design and reverse osmosis setup. System design (i.e., not over dimensioned) with a clear focus on increasing efficiency is mandatory if one wants to decrease the carbon footprint. Dialysis prescription (namely dialysis fluid flow rates) plays an important role in the dialysis fluid consumption and consequently the water consumption. A more environmentally friendly dialysis can be influenced by optimization of the current technology and development of innovative technology, and by the adoption of a conscious and coherent behavior of all persons involved in the daily routine of a dialysis unit.

Ceramic absorbed with calcium bicarbonate mesoscopic crystals partially inactivate scrapie prions.

Prion diseases are fatal neurodegenerative disorders affecting both humans and animals. The causative agent, prion, is extremely resistant to common disinfection procedures. Thus, effective prion inactivation strategies using relatively safe and less corrosive disinfectants are required. A solution containing CAC-717, mesoscopic crystals of calcium bicarbonate, exerts both antimicrobial and virucidal activities without apparent harmful effects. This study demonstrated that combined treatment with CAC-717 absorbed on ceramic (CAC-717 ceramic) and sodium dodecyl sulfate (SDS) substantially reduced the protein misfolding cyclic amplification (PMCA) seeding activity of Chandler strain scrapie mouse-brain homogenates (ScBH). Additionally, bioassays demonstrated that ScBH-inoculated mice treated with CAC-717 ceramic in combination with sodium dodecyl sulfate (SDS) did not develop disease. Furthermore, this combination effectively inactivated PMCA seeding activity on ScBH-coated stainless-steel wires below the detection limit. Overall, the findings suggest that combined treatment with CAC-717 ceramic and SDS represents a promising and less damaging approach for prion inactivation.

Outbreak of adenovirus D8 in a neonatal intensive care unit involving multiple simultaneous transmission pathways

Adenovirus (ADV) outbreaks in neonatal intensive care units (NICU) can lead to durable transmission and serious adverse outcomes. This study describes the investigation and control of an ADV-D8 outbreak in an NICU, associated with ophthalmologic equipment used during retinopathy of prematurity (ROP) screening. Cases were observed in neonates, parents and nurses. The outbreak investigation was performed including sampling patients, parents and health care workers as well as the environment for molecular detection of ADV DNA. The investigation was also conducted in the guest house where some parents were temporary residents. A retrospective cohort study focused on neonates hospitalized during the epidemic period to assess the risk associated with ROP examination. Fifteen cases were identified in neonates; all but one presented with conjunctivitis. Two healthcare workers and 18 parents acquired conjunctivitis. ADV DNA was identified on the RetCam and on the freezer shared by parents. All ADV-positive samples were typed as ADV-D8. ADV infections occurred more frequently in neonates who had ROP examinations (37.8% (14/37) vs (0.9% (1/110); P<0.001) (relative risk 41.6; (5.7-305.8)). The RetCam was disinfected between two examinations using a disinfectant that was virucidal on ADV after a 30-min contact. This outbreak was significantly associated with ROP examination with a RetCam that had a disinfection protocol ill-adapted to rapid patient turnover. In addition, nosocomial transmission via the parents to neonates and parent-to-parent transmission is likely to have played a role in the dissemination of cases. No further cases were observed after the new disinfection procedure was enforced.

Sustainable Handling of OR Waste - a Difficult Issue with Great Potential

Surgical interventions often result in large amounts of waste. Contaminated waste must not be separated in recyclable fractions but must directly be burned for thermal recycling. Clinical waste is classified according to the potential dangers in accordance with the European Waste List (EWL). Unfortunately the waste number does not contain information about recyclable material. Only about 5% of clinical waste is hazardous waste resulting from contact with notifiable diseases in accordance with the definition of §6, German Law on Infection Protection. This waste must be burned or be further sterilised. By using separate collection of packaging material without contamination with body secretions, up to 50% of waste from operating rooms can be disposed of via the German "Dual System" free of charge. Nearly 30% of packaging waste will undergo material recycling. The recycling of contaminated high-class single use surgical instruments (SUSI) is not allowed unless they pass through a disinfection procedure that is certified by the responsible authorities. Two examples will be presented. Other separated waste fractions (for example paper, pasteboard, cardboard packaging or light packaging like PET etc.) can be sold directly to specialised recycling companies. Conclusion: Responsible handling of clinical waste from operating theatres preserves our environment, can save money and motivates staff members who care for the future of our planet earth. When sustainable waste management is introduced, all staff members must be introduced from the start. Doctors must function as role models.

Tolerance of clinical vancomycin-resistant Enterococcus faecium isolates against UV-C light from a mobile source

BackgroundAdmission to a room previously occupied by patients carrying environmentally robust pathogens implies an increased risk of acquiring those pathogens. Therefore, ‘No-touch’ automated room disinfection systems, including devices based on UV-C irradiation, are discussed to improve terminal cleaning. It is still unclear if clinical isolates of relevant pathogens behave differently under UV-C irradiation compared to laboratory strains used in the approval process of disinfection procedures. In this study we analysed the susceptibility of well characterized clonally divergent vancomycin-resistant enterococci (VRE) strains, including a linezolid-resistant isolate, against UV-C radiation.MethodsSusceptibility against UV-C of ten clonally divergent clinical isolates of VRE was determined in comparison to the commonly used test organism Enterococcus hirae ATCC 10541. Ceramic tiles contaminated with 105 to 106 colony forming units/25 cm² of the different enterococci were positioned at a distance of 1.0 and 1.5 m and irradiated for 20 s, resulting in a UV-C dose of 50 and 22 mJ/cm², respectively. Reduction factors were calculated after quantitative culture of the bacteria recovered from treated and untreated surfaces.ResultsSusceptibility to UV-C varied considerably among the strains studied, with the mean value of the most robust strain being up to a power of ten lower compared to the most sensitive strain at both UV-C doses. The two most tolerant strains belonged to MLST sequence types ST80 and ST1283. The susceptibility of the laboratory strain E. hirae ATCC 10541 ranged between the most sensitive and most tolerant isolates for both irradiation doses. However, for UV-C dose of 22 mJ/cm², the reduction of the most tolerant isolate of ST1283 was statistically significantly lower compared to E. hirae ATCC 10541. The most susceptible strains belonged to the MLST sequence types ST117 and ST203.ConclusionsThese results indicate that UV-C doses reported in the literature are sufficient for the reduction of commonly used reference strains of enterococci but could be insufficient for the reduction of tolerant patient VRE-isolates in a hospital setting. Therefore, for future studies, the most tolerant clinical isolates should be used to validate automated UV-C devices or longer exposure times should be expected to ensure efficacy in the real world.

Phycocyanin-Incorporated Zirconium Dioxide Nanoparticles Activated by Photodynamic Therapy for Caries Affected Dentin Disinfection: “An Examination of Adhesive Bond Strength And Scanning Elemental Analysis”

Aim: The purpose of the present study was to examine the effect of various disinfection regimes on the antimicrobial efficacy and bond integrity of CAD against two varieties of bacteria: lacto-bacilli and S. mutans. Material and methods: The investigation used SBS, SEM, elemental analysis, disinfection procedures, and failure mode analysis. Biofilm was grown on CAD samples. The specimens were randomly separated into five groups for disinfection: Group 1 received CHX treatment, Group 2 (Phycocyanain) PC treatment, Group 3 PC-PDT, Group 4 PC@ZrO2 NP-PDT, and Group 5 CO2 therapy. After disinfection, CFUs were measured, specimens were reconstituted, and SBS was tested using a universal testing machine (UTM). Stereomicroscope analyzed failures. Kruskal-Walis tested group survival rates. ANOVA and Post Hoc Tukey were used to calculate bond value mean and standard deviation for different disinfection techniques. All analyses used p&lt;0.05. Results: The highest survival rate of S. mutans and Lactobacillus was found in group 2 CAD disinfected with PC only with no activation by PDT. The lowest survival rate of both bacteria was seen in Group 4: PC@ZrO2NP-PDT. Conclusion: PC@ZnO2NP-PDT demonstrated robust antibacterial activity against lactobacillus and S. mutans, albeit with lower bond values when compared to CHX and CO2.

Evaluation of the Efficacy of Commercial Disinfectants against African Swine Fever Virus.

African swine fever (ASF) is an economically important disease due to high morbidity and mortality rates and the ability to affect all ages and breeds of pigs. Biosecurity measures to prevent the spread of the causative agent, African swine fever virus (ASFV), include prescriptive cleaning and disinfection procedures. The aim of this study was to establish the biocidal effects of twenty-four commercially available disinfectants including oxidizing agents, acids, aldehydes, formic acids, phenol, and mixed-class chemistries against ASFV. The products were prepared according to the manufacturer's instructions and a suspension assay was performed with ASFV strain, BA71V using Vero cells (African green monkey cells) to test efficacy in reducing ASFV infection of cells. Generally, disinfectants containing formic acid and phenolic compounds, as well as oxidizing agents reduced viral titers of ASFV by over 4 log10 at temperatures ranging from 4 °C to 20 °C. Hydrogen peroxide, aldehyde, and quaternary ammonium compounds containing disinfectants were cytotoxic, limiting the detection of viral infectivity reductions to less than 4 log10. These preliminary results can be used to target research on disinfectants which contain active ingredients with known efficacy against ASFV under conditions recommended for the country where their use will be applied.

First water safety plan approach applied to a Dental Clinic complex: identification of new risk factors associated with Legionella and P. aeruginosa contamination, using a novel sampling, maintenance and management program

ABSTRACT Dental unit waterlines (DUWLs) represent a complex environment able to promote microbial contamination, due to functional, mechanical and practical risk factors. According to a water safety plan approach, the main goal is to preserve the health of dentists, dental staff and patients. The aim of this study is to develop a DUWLs water safety plan that is able to support correct and effective maintenance and disinfection procedures. Three different water systems serve 60 dental chairs: (i) water that comes directly from municipal water (Type A), (ii) water supplied by municipal water and water bottles (Type B) and (iii) water supplied only via water bottles (Type C). For each type, Legionella and Pseudomonas aeruginosa contamination was studied, by applying a new sampling scheme, based on separate sampling from water bottles, cup filler and handpieces. Type B DUWL is the only type of DUWL contaminated by L. pneumophila (ST 59) and L. anisa (mean contamination: 608.33 ± 253.33 cfu/L) detected in cup filler and handpieces, as well as the high presence of P. aeruginosa (44.42 ± 13.25 cfu/100 mL). Two subsequent shock treatments and resampling procedures were performed by increasing disinfectant dosage and contact time and removing some DUWL components linked to biofilm growth in DUWLs. A significant reduction of contamination was obtained for both microorganisms (Legionella spp.: −100%, p < 0.001 and P. aeruginosa: −99.86%, p = 0.006). The sampling strategy proposed allows us to identify the source of contamination and better focus on the maintenance and disinfection procedures. DUWLs represent an environment that requires a multidisciplinary approach, combining the knowledge of all DUWL components to correct procedures that are able to preserve the health of personnel and patients, as well as guaranteeing DUWLs’ safe functionality.

#4059 MICROBIOLOGICAL ANALYSIS OF HEMODIALYSIS WATER AT THE DOUALA GENERAL HOSPITAL, CAMEROON

Abstract Background and Aims Rigorous control of the microbiological quality of water in hemodialysis services is important because the immune system of patients with chronic renal failure is weakened. The aims of this study was to determine the microbiological quality of water for hemodialysis in Nephrology Unit of the Douala Général Hospital in order to improve the disinfection strategy. Method Twelve water samples were collected each month at different sites of the hemodialysis circuits A (inlet of filters), B (Outlet of filters / inlet of Reverse Osmosis (RO) device) and C (outlet of the RO device / close to the generator) between November 2015 and February 2016 to be analyzed. The bacteria were isolated after filtration of 100 ml of water at each site through nitrocellulose membrane with 0.45 µm microporosity deposited on the surface of the Tryptone Glucose Extract Agar (TGEA) and then incubated at room temperature (20 to 22°C) for 7 days. After transplanting to different environments, pure bacterial isolates were identified by their cultural characters and marketed biochemical galleries. Results The colony count was well above the required international standards (˃100 CFU / ml), for the hemodialysis water with a percentage of 50% of non-compliance. Among the bacteria identified, seven (07) were Gram-negative bacilli including Pseudomonas fluorescens, and Klebsiella pneumoniae subsp ozaenae, three (03) Gram-positive bacilli all Bacillus sp and three (03) Gram-positive cocci all of coagulase-negative staphylococci. The most frequently isolated bacterial genera were Pseudomonas sp (38,5%), Staphylococcus sp (23%), Bacillus sp (23%) and Klebsiella sp (15,5%). Conclusion The high bacteriological contamination of the hemodialysis water with the detection of a variety of bacteria shows that the disinfection procedure of the distribution loop is not efficient and cannot prevent the development of a biofilm. A higher frequency of disinfection (almost every week), an increase of the concentration and time of contact of the chlorine disinfection product or the use of peracetic acid and a regular monitoring can contribute to improve the quality of the hemodialysis water at the Douala General Hospital to ensure a better quality of life for patients undergoing this treatment.

A Study on The Presence of Legionella pneumophila in Hospital Water Samples from Eastern Turkey

Objective: Legionnaires' disease is a fatal form of pneumonia brought on by an infection mostly caused by the 60 different species of Legionella pneumophila. Legionnaires' illness is caused by Legionella spp.-contaminated water systems. In this work, we sought to analyze Legionella species, serogroups (SG), and contamination in the water sources of hospitals in five regions in eastern Turkey.&#x0D; Methods: Between January 2017 and December 2018, a total of 1008 samples were examined, including 2 cooling towers, 62 hot water tanks, 104 cold water tanks, and 840 faucet shower heads. Samples were collected by the standard culture method L. pneumophila SG 1, it was analyzed for L. pneumophila SG 2-16 and Legionella spp. The samples were inoculated into BCYE and GVPC medium, and the colonies were assessed using a latex agglutination test, followed by species- and serotype-level identifications.&#x0D; Results: In our study, a total of 1008 water samples were examined, of which 35.31% (356) belonged to 2017, while 64.68% (652) belonged to 2018. 83.33% of the water samples were taken from faucets and shower heads, 10.32% from the cold water tank, 6.15% from the hot water tank, and 0.2% from the cooling tower, and the highest positivity rate was observed in the hot water tank with 12.60%. 7.04% (71) of the samples were positive, and 16.9% (12) of the positive samples were L. pneumophila SG 1, 77.46% (55) L. pneumophila SG 2-14 was detected, while 5.63% (4) were nonpneumophila (Legionella spp) it has been determined as.&#x0D; Conclusions: Legionella disease remains a significant public health threat. The water tanks of hospitals and hotels should be investigated more thoroughly, the necessary disinfection procedures should be carried out frequently. All hospitals should have water management policies, and towns and large buildings should establish comprehensive water system management programs that decrease Legionella growth and transmission. To enhance prevention measures and clinical diagnosis, we also need quicker ways of detecting Legionella in water systems and clinical samples.

Analysis of antimicrobial efficacy of sodium hypochlorite and ozonated water against biofilm in oval canals.

This in vitro study compared the antimicrobial efficacy of 2.5% sodium hypochlorite (NaOCl) and 8 µg/mL ozonated water agitated by passive ultrasonic irrigation (PUI) or PUI combined with EndoActivator (EA) against mature multispecies biofilm. One hundred and five oval-shaped mandibular premolars were instrumented, sterilized, and inoculated with Enterococcus faecalis, Candida albicans, and Staphylococcus aureus, divided into: control group - saline; O3 group - ozonated water; O3 PUI group - ozonated water with PUI agitation; O3 PUI+EA group - ozonated water with PUI+EA agitation; NaOCl group - NaOCl; NaOCl PUI group - NaOCl with PUI agitation; and NaOCl PUI+EA group - NaOCl with PUI+EA agitation. Microbiological samples were collected before (S1) and after (S2) the disinfection procedures and the data were statistically analyzed using the Kruskal-Wallis test. In the culture method, there was significant disinfection in the O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). The combination of NaOCl with PUI+EA reduced microbial counts to zero (p˂0.05). In the qPCR method, there was a significant reduction in the total count of viable microorganisms in the O3 PUI, O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). It can be concluded that 2.5% NaOCl with and without agitation, as well as 8 µg/mL ozonated water with its action enhanced by the agitation techniques, were effective in root canal disinfection, and their antimicrobial efficacy is related to the microorganisms present in the biofilm.

A single-center experience with microbiologic surveillance of LivaNova 3T heater-cooler devices (HCDs)

Background: The global outbreak of Mycobacterium chimaera infections associated with HCDs resulted in new maintenance recommendations. Since 2018, HCDs have been disinfected according to instructions for use (IFU), including twice-monthly bleach disinfection and monitoring hydrogen peroxide (H2O2) to maintain a minimum daily concentration of 100 ppm. In February 2020, the IFU added the recommendation to perform microbiologic surveillance of HCD tank water to ensure effectiveness of disinfection to levels of &lt;1 colony forming unit per milliliter (CFU/mL) of nontuberculous mycobacterium (NTM). We report our experience with this microbiologic surveillance as well as that of culturing the HCD environment to investigate modes of transmission. Methods: In 2022, we began culturing tank water in 10 HCDs for NTM. For a subset of 6 HCDs, quantitative NTM culturing of tank water before and after bleach disinfection was done. After initial results indicated widespread-contamination of HCDs with M. chimaera, we performed fill water cultures from 5 sinks in 4 HCD maintenance rooms. We also conducted 20 two-hour NTM settle-plate cultures of a cardiac operating room (OR) at different sites both inside (n = 7) and outside (n = 3) the OR: 10 with the HCD (located outside the OR) turned off (controls) and 10 with HCD turned on (exposure). A paired t test was used to evaluate differences in mean recovery of NTM in tank water samples. Results: Cultures from 7 (70%) of 10 HCDs were positive, with a mean of 13.6 CFU/mL M. chimaera (Table 1). There was no significant difference between the 10 pairs of pre- and postdisinfection NTM cultures done according to the IFU from 6 HCDs: mean predisinfection cultures (15.5 CFU/mL) versus mean postdisinfection cultures (12 CFU/mL) (P = .90) (Table 2). For fill water, 1 of 7 sink samples in 1 of 4 rooms was positive for M. chimaera ( &lt;1 CFU/mL) from a specimen from a fresh 0.2-µm filter that had been stored in the fill-sink splash zone. OR settle-plate cultures showed 0 (0%) of 10 control sites and 1 (10 %) of 10 exposure sites inside the OR positive for NTM, with a single CFU of M. avium–intracellulare complex. Conclusions: Our data cannot clearly refute either of 2 possible scenarios for HCD contamination: cross contamination during device maintenance versus at the point of manufacture. Despite the IFU guidance or disinfection being implemented, disinfection procedures failed to suppress NTM contamination, and tank water within most HCDs was contaminated with M. chimaera regardless of age or whether it was deep cleaned or upgraded with an aerosol containment device.Disclosures: None

HOCl Rapidly Kills Corona, Flu, and Herpes to Prevent Aerosol Spread

The COVID-19 pandemic has escalated the risk of SARS-CoV-2 transmission in the dental practice, especially as droplet-aerosol particles are generated by high-speed instruments. This has heightened awareness of other orally transmitted viruses, including influenza and herpes simplex virus 1 (HSV1), which are capable of threatening life and impairing health. While current disinfection procedures commonly use surface wipe-downs to reduce viral transmission, they are not fully effective. Consequently, this provides the opportunity for a spectrum of emitted viruses to reside airborne for hours and upon surfaces for days. The objective of this study was to develop an experimental platform to identify a safe and effective virucide with the ability to rapidly destroy oral viruses transported within droplets and aerosols. Our test method employed mixing viruses and virucides in a fine-mist bottle atomizer to mimic the generation of oral droplet-aerosols. The results revealed that human betacoronavirus OC43 (related to SARS-CoV-2), human influenza virus (H1N1), and HSV1 from atomizer-produced droplet-aerosols were each fully destroyed by only 100 ppm of hypochlorous acid (HOCl) within 30 s, which was the shortest time point of exposure to the virucide. Importantly, 100 ppm HOCl introduced into the oral cavity is known to be safe for humans. In conclusion, this frontline approach establishes the potential of using 100 ppm HOCl in waterlines to continuously irrigate the oral cavity during dental procedures to expeditiously destroy harmful viruses transmitted within aerosols and droplets to protect practitioners, staff, and other patients.

Staphylococcus aureus in the Processing Environment of Cured Meat Products.

The presence of Staphylococcus aureus in six dry-cured meat-processing facilities was investigated. S. aureus was detected in 3.8% of surfaces from five facilities. The occurrence was clearly higher during processing (4.8%) than after cleaning and disinfection (1.4%). Thirty-eight isolates were typified by PFGE and MLST. Eleven sequence types (STs) were defined by MLST. ST30 (32%) and ST12 (24%) were the most abundant. Enterotoxin genes were detected in 53% of isolates. The enterotoxin A gene (sea) was present in all ST30 isolates, seb in one ST1 isolate, and sec in two ST45 isolates. Sixteen isolates harbored the enterotoxin gene cluster (egc) with four variations in the sequence. The toxic shock syndrome toxin gene (tst) was detected in 82% of isolates. Regarding antimicrobial resistance, twelve strains were susceptible to all the antibiotics tested (31.6%). However, 15.8% were resistant to three or more antimicrobials and, therefore, multidrug-resistant. Our results showed that in general, efficient cleaning and disinfection procedures were applied. Nonetheless, the presence of S. aureus with virulence determinants and resistance to antimicrobials, particularly multidrug-resistant MRSA ST398 strains, might represent a potential health hazard for consumers.

THE SURFACE ROUGHNESS VALUE ALTERATION OF ACRYLIC RESIN IMMERSED IN 10% CINNAMON EXTRACT AS A DISINFECTING MATERIAL

The surface roughness of acrylic denture bases can be a reservoir for food debris and microorganisms. Surface roughness can result from disinfection procedures. Cinnamon (Cinnamomum burmanii) is a spice-producing tree which has aroma and taste and contains active substances that most act as antimicrobials, namely cinnamaldehyde and eugenol, which can be used as disinfectants. The purpose of this study was to determine the change in the value of the surface roughness of acrylic resin after being immersed in 10% cinnamon extract and 0.5% sodium hypochlorite as a disinfectant. The research was experimental. The samples were heat-polymerized acrylic resin plates immersed in 10% cinnamon extract, 0.5% sodium hypochlorite, and distilled water. The results showed a significant difference in the degree of roughness of the acrylic plate immersed in 0.5% sodium hypochlorite solution compared to 10% cinnamon extract. The acrylic plate immersed in cinnamon extract had a minor level of roughness (0,37 µm) compared to the plate immersed in 0.5% sodium hypochlorite solution (0,20 µm). A cinnamon extract of 10% did not affect the roughness of the acrylic plate.

A survey on awareness and knowledge among dentist practicing regenerative endodontics towards current regenerative endodontic protocols and the scaffolds used in regenerative dentistry

There are many inconsistencies in the protocols followed for Regenerative Endodontic Procedures (REP’s).This study was formulated with an aim to conduct a survey among Pediatric Dentists, Endodontists and General Practioners treating Necrotic young permanent teeth to examine their awareness and Knowledge on Current Regenerative Endodontic Protocols and Scaffolds used in regenerative dentistry. MethodsA Cross-Sectional Survey was carried out amongst 100 Pediatric dentists,100 Endodontists and 100 General Practioners. It was web-based survey and the questionnaire was formulated and all the items in the questionnaire were tested for reliability and validity before circulation of the questionnaire for the purpose of the study. ResultsThe results of the study indicated that all the three groups were unaware that failure of cases should be reported to AEE (American Academy of Endodontics) REP Database and only 20.2, 20.1 and 0.3 % of Pediatric dentists,Endodontists and General Dentists preferred Regenerative Dentistry as a clinical protocol for REP. With respect to knowledge regarding irrigation and disinfection procedures all three groups were lacking in the knowledge regarding intracanal medicament for disinfection and the irrigation solutions. ConclusionThere is a lack of homogeneity in protocols followed for REP among those practicing Regenerative Endodontics as a protocol. Since it’s an evolving science there is a need to bring about a uniformity in practices to increase the evidences to support the causal effect relation of regenerative endodontics.

DePolymerase Predictor (DePP): a machine learning tool for the targeted identification of phage depolymerases

Biofilm production plays a clinically significant role in the pathogenicity of many bacteria, limiting our ability to apply antimicrobial agents and contributing in particular to the pathogenesis of chronic infections. Bacteriophage depolymerases, leveraged by these viruses to circumvent biofilm mediated resistance, represent a potentially powerful weapon in the fight against antibiotic resistant bacteria. Such enzymes are able to degrade the extracellular matrix that is integral to the formation of all biofilms and as such would allow complementary therapies or disinfection procedures to be successfully applied. In this manuscript, we describe the development and application of a machine learning based approach towards the identification of phage depolymerases. We demonstrate that on the basis of a relatively limited number of experimentally proven enzymes and using an amino acid derived feature vector that the development of a powerful model with an accuracy on the order of 90% is possible, showing the value of such approaches in protein functional annotation and the discovery of novel therapeutic agents.