Disinfection Protocols Research Articles

Dimensional Stability of Maxillofacial Prosthetic Room Temperature Vulcanized Silicones after Various Disinfection Protocols: An In Vitro Study

Dimensional Stability of Maxillofacial Prosthetic Room Temperature Vulcanized Silicones after Various Disinfection Protocols: An In Vitro Study

Role of vehicles on antimicrobial efficacy of calcium hydroxide

Adequate disinfection of the root canal system plays a crucial role in ensuring the enduring success of endodontic therapy. While chemomechanical preparation is a major part of disinfection protocol, intracanal medicaments, such as calcium hydroxide (Ca(OH)2), help in eliminating the microbial flora that remains even after chemomechanical preparation. Enhancing the action of these antimicrobial agents will improve disinfection. Various vehicles have been studied that augment the action of intracanal medicaments and debate about their supremacy has been ongoing. Aqueous, viscous, and oily tensioactive agents serve their functions and have their own limitations. This review was undertaken to comprehensively analyze the effect of various vehicles on the antimicrobial activity of Ca(OH)2. In conclusion, aqueous, viscous, and oily vehicles have different advantages, and the type of vehicle utilized depends on the clinical situation at hand.

Effect of Thermal Aging and Chemical Disinfection on the Microhardness and Flexural Strength of Flexible Resins

This article examines the effects of thermal aging and chemical disinfection on the microhardness and flexural strength of flexible resins. The influence of the resin type on the mechanical properties was also investigated. Two flexible resins, Deflex Classic SR and Deflex Supra SF, produced by the injection method, and a thermopolymerizable acrylic resin—ProBase Hot, produced by the flasking method, were subjected to 1000 cycles of thermal aging and three chemical disinfection protocols (n = 8), with daily immersion and during a recommended time, in Corega Whitening, Corega Oxygen Bio-Active, 2.5% sodium hypochlorite, and distilled water (control). Knoop microhardness and three-point flexural strength were evaluated. Data were analyzed using Wilcoxon, Mann–Whitney and Kruskal Wallis tests (α = 0.05). The results varied between 14.5 KHN and 80.1 MPa for ProBase Hot and 7.3 KHN for Deflex Classic SR and 52.5 MPa for Deflex Supra SF. Thermal aging reduced the microhardness of the flexible resins, but not their flexural strength. The microhardness of Deflex Classic SR was influenced by chemical disinfection with Corega Bio-active (p < 0.001). The flexural strength of Deflex Supra SF was influenced by chemical disinfection with Corega Whitening (p < 0.05). It can be concluded that chemical disinfection led to changes in the flexible resins and should be used with caution to maintain the mechanical properties of the resins. Flexible resins showed reduced resistance to physical and chemical environmental influences, which can affect their longevity.

Inhibition of Salmonella Enteritidis adhesion and biofilm formation by β-glucosidase B from Microbacterium sp. BG28

SalmonellaEnteritidis is the most commonly reported pathogen for foodborne illness outbreaks in both underdeveloped and developed regions. S. Enteritidis biofilms, which form on various food contact surfaces, are resistant to conventional physical and chemical cleaning and disinfection procedures routinely used in food processing. The aim of this study was to identify novel, industrially applicable enzymes that are active against S. Enteritidis biofilms. We describe the properties and anti-biofilm activity of heterologously expressed β-glucosidase B derived from the environmental strain Microbacterium sp. BG28 (BglB-BG28) collected from gills of bream fish. The enzyme inhibited adhesion and the early stages of biofilm formation in clinical isolates of S. Enteritidis. At a concentration of 200 μg/mL, BglB-BG28 effectively reduced biofilm formation, by decreasing biofilm biomass by 50% and metabolic activity within biofilms by 80%. The enzyme reduced the formation of air-liquid biofilms on various surfaces, including plastic, glass and metal, as observed by fluorescence microscopy. BglB-BG28 inhibited biofilm formation in Escherichia coli, another important food pathogen that also forms cellulose-rich biofilms. Using o-NPG as substrate, the enzyme showed activity at temperatures up to 50 °C and in a pH range between 4 and 8, high tolerance to sodium chloride and glucose, and compatibility with nonionic detergents. Importantly, no toxicity was observed in the model system Caenorhabditis elegans even at an enzyme concentration of 1 mg/mL. These results suggest that the β-glucosidase BglB-BG28 is a promising candidate for the development of a new enzyme-based disinfection protocol that can be used in food processing facilities.

Prevalence of Vertical Root Fractures in a University Endodontics Program versus a Private Endodontics Office.

Vertical root fractures (VRFs) typically have a poor prognosis with an extraction or occasionally root amputation as the preferred treatment. VRFs have been considered an epidemic, motivating changes in the access openings, as well as in the preparation and disinfection protocols of endodontic treatment. Hence, we aimed to evaluate the prevalence of VRFs by tracking cases in both a University Endodontic Program (UEP) and a private endodontics practice (PP). We also evaluated changes in prevalence during COVID-19 along with the alterations in the frequency of cases diagnosed by clinical and radiographic signs which were later confirmed by direct visualization compared to those in which the suspicion was based on clinical and radiographic signs alone. This retrospective study looked at the prevalence of VRF in patient records at UEP and a PP. Data for the pre-COVID-19 and COVID-19 time periods were extracted from patient records and referral letters then compared. Data for suspected and confirmed prevalence were compared. The UEP group included 21,156 patients while the PP group comprised 7,209 patients. The prevalence of VRFs in the former cohort was 1.80%, while 2.62% of the latter cohort exhibited VRFs with a combined total of 2.01%. The combined total prevalence of VRFs pre-COVID-19 was 1.72%, increasing from 2.1% to 3.82% during COVID-19 (p < 0.0001). The same applied to suspected cases for both clinical settings. The increase in confirmed cases between the two periods was statistically significant for the UEP group (p=0.0202) but it was insignificant for the PP group (p=0.0721). The combined prevalence for VRFs was 2.01% for all years denying the claim that VRF is a pandemic phenomenon. COVID-19 period saw almost a double increase in the prevalence of VRF compared to pre-COVID-19 era. This was consequently associated with a significant increase in the number of suspected VRF cases.

Radiology Department: A Potential Source of Multidrug-Resistant Microorganisms: A Cross-Sectional Study at Tertiary Hospital, Palestine.

Globally, healthcare facilities face a great challenge in the form of hospital-acquired infections (HAIs). Aside from the morbidity and mortality they cause, these illnesses are also extremely costly. Research on infection transmission in the medical field has been considerable, but not so much in the radiology department. This study aims to identify the presence of multidrug-resistant (MDR) microbes on surfaces that are frequently touched in computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), plain X-ray examination rooms, and portable radiography that are susceptible to contamination as well as to investigate the potential dangers of contracting MDR organisms to patients and healthcare providers. Materials and Method. In this study, 160 swab samples were collected from the radiology department during May and June 2022. Samples were obtained from 80 predefined surfaces twice within and outside of CT and MRI examination rooms as well as from US and plain X-ray machines and portable X-ray machines. Samples were taken at 7:00 a.m. using cotton swabs following the regular cleaning procedure. Bacterial colony-forming units (CFUs) per square centimeter were calculated after swabbing a 100 cm2 surface. Nearly all of the surfaces tested had bacterial CFUs. The highest contamination rate was found on keyboards ranging from (1.2-8) CFU/cm2, the sides of patient tables (1.2-20) CFU/cm2, knee coil (2.4-3) CFU/cm2, and patient leg supports (1.2-8) CFU/cm2. A noticeable increase in the contamination was noticed in June compared to May, and this was consistent with the increase in the number of isolated patients in the hospital, the workload in the radiology department, and the number of patients referred to the hospital. In our study, none of the examined sites showed contamination with MDR Gram-negative bacteria such as extended-spectrum beta-lactamases producing Enterobacterales (ESPL) or Carbapenemase-producing Enterobacterales (CPE). On the other hand, methicillin-resistant Staphylococcus (MRS), vancomycin-resistant Staphylococcus (VRS), and vancomycin-resistant Enterococcus (VRE) were detected. All of the radiology department equipment and sites could be a source of bacterial infection including MDR, so the obligatory and committed disinfection protocol must be revised and implemented in the morning and between patients.

Efficacy of an impression disinfectant solution after repeated use: An in vitro study

Statement of problemThere are very few studies using Benzalkonium Chloride (BAC) as an active disinfection agent for immersion techniques and there are no studies investigating the efficacy of repeated use of a disinfectant solution. PurposeThis study evaluated an impression disinfectant by testing bacterial contamination of disinfectant batches used in a clinical setting after repeated use. Materials and methodsLiquid samples were collected from impression disinfectant solutions used to disinfect dental impressions taken at a university dental clinic. The experimental samples (500 ml from 1 L of solution) were collected from teaching and professional clinics and the in-house commercial processing laboratory and stored at room temperature each day of clinic operation over five weeks. To determine to what extent the disinfectant efficacy of the active product decreased over time, the following tests were carried out: a. Inoculation b. Gram staining technique c. Matrix Assisted Laser Desorption/Ionization Mass spectrometry (MALDI- MS). Microbial growth was monitored and photographed. A culture revival was made from colonies grown on sheep blood agar, to isolate pure colonies incubated for 24 h at 37 °C. Each morphologically distinct type of colony was gram stained and MALDI spectrometry analysis was performed using the VITEK MS (BioMerieux Inc.) ResultsEvidence of growth of bacteria was detected in teaching clinics’ samples, and no growth from the professional clinic or the commercial laboratory. ConclusionsThe study demonstrated that the impression disinfectant solution tested is effective against common oral bacteria, despite some rare species such as Bacillus circulans, Bacillus horneckiae, Bacillus altitudinis/pumilus and Bacillus cereus showing evidence of survival in solutions used for disinfection of impressions. However, in a high use teaching clinic environment its efficacy deteriorated. Though a second level disinfection protocol in the commercial laboratory-maintained impression disinfection.

Assessing the antimetabolite activity of modified vitamin B12 analogues against Lactobacillus delbrueckii and Listeriamonocytogenes

Developing novel strategies against foodborne pathogens, like Listeria monocytogenes, is crucial due to their growing resistance to current hurdles and disinfection protocols. Disruption of the cobalamin biosynthesis pathway revealed the importance of vitamin B12 (B12) in L. monocytogenes tolerance to cold and copper stress, suggesting that B12 analogues have potential as hurdles against it on food. In 2021, 10-Br-methyl cobalamin (10-Br-MeCbl) was introduced as an L. monocytogenes antimetabolite. Herein, we re-evaluated 10-Br-MeCbl and tested seven related B12 analogues against six L. monocytogenes strains and a B12 auxotrophic Lactobacillus delbrueckii strain. No analogue, including 10-Br-MeCbl, was inhibitory to L. monocytogenes. In contrast, 10-Br-MeCbl, 10-Br-CNCbl, 10-Br-PhCbl, and 10-Br-CNCbl-c-lactam inhibited L. delbrueckii growth (13–27%) at concentrations 50-folds higher than B12. This inhibitory activity was lost under conditions of B12 abundance, indicating competitive inhibition. The activity of phenylcobalamin-c-lactam against L. delbrueckii differed compared to a previous study, emphasizing that the antimicrobial activity of B12 derivatives is not universal and must be examined for each species under the application conditions. Overall, while this study illustrates the potential of B12 antimetabolites as antimicrobials, it also demonstrates that other classes of B12 antimetabolites and/or improved strategies are required for tackling pathogens like L. monocytogenes.

Evaluation of different disinfection protocols for seed germination of Ocimum basilicum L.

The aim of this study was to discriminate between different disinfection protocols applied to common basil seeds for in vitro establishment on Murashige &amp; Skoog medium. The aim of this approach was not only to overcome seed dormancy, but also to decisively influence the germination process in order to achieve a significant increase in the proportion of seeds that germinate successfully. In the Colombian context, where some 156 species of medicinal plants are currently marketed, basil (Ocimum basilicum L.), originally from Asia Minor, stands out as one of the most widely used plants in the world. In the department of Valle del Cauca, medicinal plants have emerged as protagonists in contrast to the monoculture of sugar cane (Saccharum Officinarum L.) that dominates the region. However, basil faces significant challenges related to seed dormancy, a condition that negatively affects germination and therefore directly affects yield. In this scenario, 21 treatments were carried out in the Biological Sciences Laboratory of the Central Unit of Valle del Cauca, which showed a marked variability and influence in phenological development, especially in stem and leaf growth. Treatment 12 (0.7% NaClO) showed the highest percentage of basil seed germination (80%). It is imperative to explore new protocols that effectively contribute to the basil production process by overcoming seed dormancy.

Effect of photodynamic therapy on the healing of periapical lesions after root canal retreatment: 1-year follow up randomized clinical trial

BackgroundThe aim of this randomized clinical trial was to evaluate the effects of photodynamic therapy (PDT) after traditional activated final irrigation protocol (ultrasonically activated irrigation, UAI) on periapical lesion healing after single–visit root canal retreatment. MethodsWe included 36 patients with asymptomatic chronic apical periodontitis with periapical lesions larger than 5 mm and teeth sensitive to percussion and palpation, who had previous root canal treatment. All patients who signed informed consent underwent cone-beam computed tomography (CBCT) to determine and calculate the preoperative volume of the periapical lesion. Patients were randomly distributed into two groups according to the final disinfection protocol: Group 1; UAI (NaOCl, EDTA, and NaOCl), Group 2; UAI + PDT. All patients underwent single-visit root canal retreatment using rotary instrumentation and standardized irrigation (3 %NaOCl) by the same endodontist. The root canals were filled with epoxy resin-based sealer and single-cone gutta-percha, followed by control radiography. After one year, a new CBCT scan of the teeth was performed to calculate the reduction in the initial periapical lesion as a measure of periapical healing. For the statistical analysis, the chi-square test variants, Fisher's exact test and the Fisher-Freeman-Halton test were used at the level of significance set at 5 %. ResultsThere were no significant differences between the groups in terms of age, sex, preoperative and postoperative lesion volume (p > 0.05), and reduction of periapical lesion volume (median, 86.98 % for UAI and 79.72 % for UAI+PDT) (p = 0.970). Additional use of PDT after UAI did not contribute to the healing of periapical lesions. ConclusionThe UAI and UAI+PDT protocols had equal effects on healing of periapical lesion.

Regenerative endodontic procedures in immature permanent teeth with pulp necrosis: the impact of microbiology on the clinical and radiographic outcome

AimsThe current study aimed to determine how the regenerative endodontic procedures (REP) disinfection strategy influences overall bacterial load and REP outcomes. Different bacterial species in the teeth were also examined.MethodsA previously reported non-randomized controlled clinical research on REP ± leukocyte and platelet-rich fibrin gathered microbial samples from 14 of 29 patients during REP (LPRF). Four microbiological samples were obtained in two treatment sessions. S1 and S2 were taken before and after the first irrigation with 1.5% NaOCl and saline. Samples S3 and S4 were obtained before and after rinsing with 17% EDTA in the second treatment session. Microbial samples were identified using quantitative polymerase chain reaction with species-specific primers.ResultsThe total bacterial load recovered from patients showed a significant (p &amp;lt; 0.05) decrease after the first treatment and was maintained throughout the second treatment. Fusobacterium nucleatum, Treponema denticola, and Enterococcus faecalis were the most prevalent species in root canals, detected in all analyzed cases (100%), followed by Prevotella intermedia and Tannerella forsythia, both in six of 14 (42.9%) cases. The presence of these abundant species was significantly reduced after S1. Parvimonas micra was present in four of 14 (28.6%) cases and Actinomyces naeslundii in two of 14 (14.3%) cases. Filifactor alocis, Porphyromonas endodontalis, and Porphyromonas gingivalis were each detected in only one of 14 (7.1%) cases. No statistical correlation could be made between bacterial species and clinical or radiographic outcomes due to the small sample size. In the LPRF group, two cases required retreatment due to early post-treatment flare-up, and two other cases presented radiographically a persistent apical periodontitis 3 years after treatment. In the control group, all analyzed cases were clinically asymptomatic after treatment, and radiographically the final periapical index score at the last recall revealed healthy periapices.ConclusionThe REP disinfection protocol of the present study seems to be satisfactorily effective in reducing the total bacterial load, omitting clinical symptoms, and inducing periapical bone healing in immature permanent teeth with pulp necrosis. LPRF seems to prevent these outcomes from being achieved and should consequently not be recommended in REP.

Comparative evaluation on the effect of different cavity disinfectant nano gels; Chlorohexidine, Propolis, Liquorice versus Diode Laser in terms of composite microleakage (comparative in vitro study)

IntroductionThe application of different cavity disinfectants is an essential step that eliminates bacteria after cavity preparation. However, some of these materials may affect restoration sealing ability.AimThis study aimed to assess the degree of microleakage at the tooth restoration interface after using different nano prepared cavity disinfectants versus Diode Laser.Materials and methodsThree disinfectants were prepared on the nanoscale; Propolis, Liquorice and Chlorhexidine. A total of 40 extracted premolars with standard class V cavities were prepared on the facial surface. Teeth were divided into five groups according to the applied cavity disinfection protocol; no treatment, Chloehexidine, Propolis, Liquorice, and Diode Laser. After application of composite resin restoration, all teeth were subjected to thermocycling, afterwords the degree of microleakage was measured in micrometers. Data were analyzed by one-way analysis of variance (ANOVA) test, followed by Bonferroni’s and Tukey’s post hoc test.ResultsThe highest mean microlekage value was recorded in no treatment group, followed by Liquorice, Propolis. While Diode Laser group showed the lowest degree of microleakage.ConclusionDiode Laser cavity disinfectant has no negative effect on the restoration sealing ability. Nano prepared Propolis showed comparative results to nanoChloehexidine as both had low degree of microleakage.

Synergistic Strategies of Heat and Peroxyacetic Acid Disinfection Treatments for Salmonella Control.

The food industry has recognized a pressing need for highly effective disinfection protocols to decrease the risk of pathogen emergence and proliferation in food products. The integration of antimicrobial treatments in food production has occurred as a potential strategy to attain food items of superior quality with respect to microbiological safety and sensory attributes. This study aims to investigate the individual and synergistic effects of heat and peroxyacetic acid on the inactivation of bacterial cells, considering various contact times and environmental conditions. Four Salmonella serotypes, isolated from industrial meat production surfaces, were employed as model organisms. By systematically assessing the impacts of individual factors and synergistic outcomes, the effectiveness of bacterial cell inactivation and the efficiency of heat and peroxyacetic acid could be predicted. To better approximate real-world food processing conditions, this study also incorporated a bovine albumin-rich condition as a simulation of the presence of organic loads in processing steps. The findings revealed the essential need for a synergistic interplay of investigated parameters with the following optimized values: 1.5% concentration of peroxyacetic acid, temperature range of 60-65 °C, and contact time of 3 min for the complete effect regardless of the degree of contamination.

Effects of Irrigants on Pulp Stem Cells: A Systematic Review

Endodontic intervention in necrotic immature permanent teeth is usually a clinical challenge. With appropriate case selection, regenerative treatment can be effective, providing a desirable outcome. However, there is still no consensus on the optimal methods to achieve predictable clinical outcome. To ensure a successful regenerative procedure, it is essential to investigate the appropriate disinfection protocols and the use of biocompatible molecules in order to control the release of growth factors and the differentiation of stem cells. This systematic review summarizes the present knowledge regarding the effect of intracanal irrigants on the dental derived stem cells fate in regenerative endodontic procedures. Keywords: Chlorhexidine; Growth factors; Intracanal irrigants; NaOCl; Regenerative endodontics;

The pharmacy service facing the logistics of safely dispensing, storing and preserving drugs in healthcare units

In response to the SARS-CoV-2 pandemic, the Hospital Pharmacy Services have quickly adapted to respond to a critical situation characterized by the constant and continuous admission of patients with severe pneumonia who needed treatment, requiring a transformation of the hospital in order to increase the number of hospital and critical beds. Moreover, other out-of-hospital spaces have been transformed into hospitalization units to absorb the large number of patients that had to be treated and isolated.To guarantee the distribution of medicines and the quality of the pharmaceutical care, drug distribution systems, such as unit dose and automated dispensing systems, have undergone transformations. Standard stocks were assigned for COVID units, and different dispensing circuits to avoid the risk of cross-contamination between COVID and non-COVID units were created, as well as disinfection protocols for medication transport systems and medication return protocols. All this without forgetting COVID treatment protocol's changes that were affected by the availability of the drugs.The increase in the number of beds in out-of-hospital spaces, such as field hospitals, hotels, socio-medical centers and nursing homes, has challenged Pharmacy Services, since new medication dispensing and conciliation circuits have been created forcing the increase of pharmacy staff's presence and modifying work shifts, to afford all the new tasks successfully.Development of contingency plans for the different Pharmacy Service activities and providing fluent communication channels are key elements for crisis situations or health emergencies such as the current pandemic.

Polarity-dominated chitosan biguanide hydrochloride-based nanofibrous membrane with antibacterial activity for long-lasting air filtration

Facemasks play a significant role as personal protective equipment during the COVID-19 pandemic, but their longevity is limited by the easy dissipation of electrostatic charge and the accumulation of bacteria. In this study, nanofibrous membranes composed of polyacrylonitrile and chitosan biguanide hydrochloride (PAN@CGH) with remarkable antibacterial characteristics were prepared through the coaxial electrospinning process. Particulate matter could be efficiently captured by the fibrous membrane, up to 98 % or more, via polarity-dominated forces derived from cyano and amino groups. As compared commercial N95 masks, the PAN@CGH was more resistant to a wider variety of disinfection protocols. Additionally, the nanofibrous membrane could kill >99.99 % of both Escherichia coli and Staphylococcus aureus. Based on these characteristics, PAN@CGH nanofibrous membrane was applied to facial mask, which possessed an excellent and long-lasting effect on the capture of airborne particles. This work may be one of the most promising strategies on designing high-performance face masks for public health protection.

The Effect of Microwave Irradiation and Some Denture Cleansers on The Bond Strength of Soft Liner to CAD/CAM-Milled Acrylic Resin

Disinfection of dentures and denture liners was desired for cross-contamination prevention and improved safety. Nonetheless, it has been discovered that these procedures impact the physical and mechanical features of denture liners.To assess the impact of different disinfection procedures on the tensile bond strength of an acrylic-based soft liner with CAD/CAM-based acrylic denture resin. Material and Methods: 25 specimens were collected and randomly divided into five groups (sodium hypochlorite, chlorohexidine, cleansing tablet, microwave, and control groups), following the daily disinfection protocol, the samples were stored at room temperature (23±2°C) in distilled water. After 30 days, the tensile bond strength was determined using universal testing equipment (Gester, China). The specimens were subjected to force by the machine at a steady crosshead speed of 5 mm/minute till the failure was recorded. The data were analyzed using statistics software (SPSS). Results: Showed that the control group had a higher mean value for bond strength, whereas the chlorhexidine group had a lower value. There was no significant difference between the control and cleansing tablet groups. However, they were significantly different from the microwave, CHX, and NaOCl groups. The NaOCl soft liner group is significantly different from all the other groups. No significant difference is found between microwave and CHX disinfected liner groups. Conclusion: The tensile bond strength of all disinfected soft liners decreased as compared with the control, which was not significant with the protefix tab but significant with the NaOCl, CHX, and microwave groups.

Single-use accessories and endoscopes in the era of sustainability and climate change-A balancing act.

Gastrointestinal (GI) endoscopy is among the highest waste generator in healthcare facilities. The major reasons include production of large-volume non-renewable waste, use of single-use devices, and reprocessing or decontamination processes. Single-use endoscopic accessories have gradually replaced reusable devices over last two decades contributing to the rising impact of GI endoscopy on ecosystem. Several reports of infection outbreaks with reusable duodenoscopes raised concerns regarding the efficacy and adherence to standard disinfection protocols. Even the enhanced reprocessing techniques like double high-level disinfection have not been found to be the perfect ways for decontamination of duodenoscopes and therefore, paved the way for the development of single-use duodenoscopes. However, the use of single-use endoscopes is likely to amplify the net waste generated and carbon footprint of any endoscopy unit. Moreover, single-use devices challenge one of the major pillars of sustainability, that is, "reuse." In the era of climate change, a balanced approach is required taking into consideration patient safety as well as financial and environmental implications. The possible solutions to provide optimum care while addressing the impact on climate include selective use of disposable duodenoscopes and careful selection of accessories during a case. Other options include use of disposable endcaps and development of effective high-level disinfection techniques. The collaboration between the healthcare professionals and the manufacturers is paramount for the development of environmental friendly devices with low carbon footprint.

Hospital mattresses: Thermal disinfection against bacteria, fungi and virus

Disinfection protocols for medical items play an important role in the prevention and con-trol of healthcare-associated infections. Regarding mattresses, disinfection with chemical products only cleans the surface, leading to failures in the execution of final processes of cleaning. This study aims to evaluate the antimicrobial activity of ECOSTOVE Thermal Chamber for the disinfection of hospital mattresses. Microbiological analyses were carried out under different experimental con-ditions, considering microbial viability, treatment time and position of inoculum on mattress. Staphylococcus aureus, Klebsiella pneumoniae, Candida albicans and Chikungunya virus were in-oculated at five pre-defined positions on the external and internal areas of hospital mattresses. Im-prints were done using RODAC plates, before and after heat treatment to evaluate colony-forming unit and microbial viability. The percentage of microbial inhibition obtained by heat treatment of the ECOSTOVE varied between 83.1 to 100%. The best results were observed for the enveloped Chikungunya (100% inhibition) and C. albicans (between 97.6 and 100%), followed by K. pneu-moniae (85.4-100%) and S. aureus (83.1-99.1%). Due to the significant antimicrobial activity of ECOSTOVE, it can be integrated into standard hospital hygiene and cleaning procedures as a prom-ising strategy in the control of healthcare-associated infections.

IMPROVEMENT OF THE CHRYSANTHEMUM × KOREANUM HORT. CLONAL MICROPROPAGATION PROCESSES USING BACILLUS MEGATERIUM ONU500

The aim of this study was to improve the Chrysanthemum × Koreanum micropropagation processes using Bacillus megaterium ONU500 at the post-aseptic adaptation stage. Methods. At the initial stages of clonal micropropagation, two surface sterilization protocols with different fungicidal preparations were tested. The influence of the agar concentration in the medium on the development of explants was determined. At the ex vitro adaptation stage, the roots of the microclones were inoculated with bacteria of the strain B. megaterium ONU500. Results. The most effective protocol for plant material surface disinfection, which included quinozol and ethanol, was established. It was determined that the use of Murashige and Skoog (MS) nutrient medium supplemented with 0.4% agar at the stage of in vitro culture establishment increased the survival of chrysanthemum initial explants by 9.3% and accelerated proliferation by 1 day. It was found that inoculation of the chrysanthemum microclone rhizosphere with bacteria had a positive effect on the growth of adapted plantlets, increasing their survival rate by 20.4–22.2%, shoot height by 1.8–1.9 cm, and average number of nodes by 2.0–2.2 nodes. Conclusion. The effectiveness of the use of fungicides for the treatment of chrysanthemum plant material during in vitro culture establishment and the influence of the consistency of the nutrient medium on the development of explants were determined, which is new and relevant for increasing the efficiency of clonal micropropagation of this plant. Also, experiments on the inoculation of chrysanthemum microclones at the stage of ex vitro adaptation were carried out for the first time, and the positive effect of such inoculation on the morphometric characteristics of seedlings and their survival rate was shown. When establishing chrysanthemum explants in vitro, it is recommended to use the fungicide quinozol for surface sterilization, and carry out cultivation in a semi-liquid nutrient medium with 0.4% agar. At the postaseptic adaptation stage of microclones, it is advisable to inoculate the roots with bacteria of the strain B. megaterium ONU500 at concentrations of 108–109 CFU/ml.