Microbial Efficacy Research Articles

Inactivation of Salmonella, Enterococcus faecium and natural microbiota on dry food matrices with microwave-driven plasma-processed air

This study explores the efficacy of plasma-processed air (PPA) as a non-thermal treatment for decontamination of dry food surfaces, such as wheat grains, black peppercorns, and onion flakes. We compared the effect of various inoculum types of Enterococcus faecium, revealing a higher resistance of the powder form compared with liquid and slurry inocula on black peppercorns. Furthermore, Enterococcus faecium NRRL B-2354 appeared to be a suitable control indicator for Salmonella. The PPA efficacy varied across matrices, being higher on medium agar (7.0 ± 0.5 log10), followed by wheat grains (2.1 ± 0.2 log10), black peppercorns (1.5 ± 0.1 log10), and no reduction on onion flakes. Variation was also found across microorganisms, as the natural microbiota was reduced on wheat grains (1.6 ± 0.6 log10 for mesophilic count and 0.8 ± 0.3 log10 for spores), while on black peppercorns this was only achieved after upscaling (1.3 ± 0.2 log10 for mesophilic and 1.5 ± 0.1 log10 for spores). The findings of this study give guidance to further optimize the application of PPA treatment by changing the technical parameter settings of the plasma setup to increase the microbial efficacy and/or combining the PPA treatment with other methods to enhance microbial control.

Dual release of daptomycin and BMP-2 from a composite of β-TCP ceramic and ADA gelatin

BackgroundAntibiotic-containing carrier systems are one option that offers the advantage of releasing active ingredients over a longer period of time. In vitro sustained drug release from a carrier system consisting of microporous β-TCP ceramic and alginate has been reported in previous works. Alginate dialdehyde (ADA) gelatin gel showed both better mechanical properties when loaded into a β-TCP ceramic and higher biodegradability than pure alginate.MethodsDual release of daptomycin and BMP-2 was measured on days 1, 2, 3, 6, 9, 14, 21, and 28 by HPLC and ELISA. After release, the microbial efficacy of the daptomycin was verified and the biocompatibility of the composite was tested in cell culture.ResultsDaptomycin and the model compound FITC protein A (n = 30) were released from the composite over 28 days. A Daptomycin release above the minimum inhibitory concentration (MIC) by day 9 and a burst release of 71.7 ± 5.9% were observed in the loaded ceramics. Low concentrations of BMP-2 were released from the loaded ceramics over 28 days.

Chemical resistance testing of plastics: material compatibility of detergent and disinfectant products

Surface cleaning and disinfection is a key part of breaking the chain of transmission and reducing the risk of healthcare associated infections. However, if cleaning and disinfectant formulations are incompatible with surface materials, frequent application can cause premature failure of plastics due to environmental stress cracking (ESC). Material compatibility should be considered when selecting cleaning and disinfecting products. This study evaluated the tendency of 2-in-1 wet wipes to cause ESC in commonly found healthcare plastics. Eight ready-to-use 2-in-1 wet wipes were evaluated for their ability to cause ESC in 13 plastic surfaces in accordance with BS EN ISO-22088-3. Polymers were exposed to fluid extracted from wipes at a fixed strain of 0.5% for seven days and assessed for cracking, crazing, and tensile strength in accordance with ISO 527-2:2012. All 2-in-1 wet wipes tested contained ESC agents, although the severity of ESC varied. Products with higher pH (>8.0) were responsible for 74% of failures, with 22 of the 39 tested plastics visibly cracking. Although the primary active in all tested wipe formulations were quaternary ammonium compounds, formulations that included small/medium amines or alcohol demonstrated a greater propensity for plastic cracking. Each disinfectant formulation exhibits a unique spectrum of microbial efficacy and unique potential to cause surface damage. This may result in device failures and recalls that could compromise patient and staff safety. BS EN ISO-22088-3 can support material compatibility assessments of disinfectant and detergent products before they come to market.

Carbon slow-release and enhanced nitrogen removal performance of plant residue-based composite filler and ecological mechanisms in constructed wetland application

Stable carbon release and coupled microbial efficacy of external carbon source solid fillers are the keys to enhanced nitrogen removal in constructed wetlands. The constructed wetland plant residue Acorus calamus was cross-linked with poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) to create composite solid carbon source fillers (Ac-BDPs). The study demonstrated the slow release of carbon sources from Ac-BDPs with 35.27 mg/g under an average release rate of 0.88 mg/(g·d). Excellent denitrification was also observed in constructed wetlands with Ac-BDPs. Moreover, the average removal rate of nitrate nitrogen (NO3−-N) was increased by 1.94 and 3.85 times of the blank groups under initial NO3−-N inputs of 5 and 15 mg/L, respectively. Furthermore, the relatively high abundances of nap, narG, nirKS, norB, qnorZ and nosZ guaranteed efficient denitrification performance in constructed wetlands with Ac-BDPs. The study introduced a reliable technique for biological nitrogen removal by using composite carbon source fillers in constructed wetlands.

Effect of mango butter on the physicochemical properties of beeswax-Moringa seed oil-based oleogels for topical application

Objective The purpose of this research was to determine any connections between the characteristics of oleogels made of beeswax and the impact of mango butter. Methods Oleogel was prepared through inverted tube methods, and optimized through oil binding capacity. Other evaluations like bright field and polarized microscopy, Fourier-transform infrared (FTIR) spectroscopy, crystallization kinetics, mechanical study, and X-ray diffractometry (XRD). The drug release kinetic studies and in vitro antibacterial studies were performed. Results FTIR study reveals that the gelation process does not significantly alter the chemical composition of the individual components. Prepared gel exhibiting fluid-like behavior or composed of brittle networks is particularly vulnerable to disruptions in their network design. The incorporation of mango butter increases the drug permeation. In-vitro microbial efficacy study was found to be excellent. Conclusion The studies revealed that mango butter can be used to modify the physico-chemical properties of the oleogels.

Development of sustainable ternary bionanocomposite film reinforced with nanocellulose and nanoclay for microbial efficacy

Development of sustainable ternary bionanocomposite film reinforced with nanocellulose and nanoclay for microbial efficacy

Antimicrobial Efficacy of Calcium Hydroxide with Different Herbal Additives: An In-vitro Study

Introduction: Microorganisms such as Enterococcus faecalis, Enterobacteriaceae, and Candida albicans are associated with persisting infections and can cause endodontic failure. The addition of herbal additives such as Triphala, Clove, and Activated charcoal to Calcium hydroxide enhances the microbial efficacy within the root canal. Aim: To evaluate and compare the anti-microbial efficacy of calcium hydroxide with various herbal additives against E. faecalis and C. albicans using Agar Diffusion Test (ADT) and Direct Contact Test (DCT). Materials and Methods: The present in-vitro study was conducted in Bangalore, Karnataka, between July 2023 and September 2023. Ethical clearance was obtained from the institution. Sabouraud Dextrose Agar (SDA) and Mueller-Hinton Agar were prepared and used to culture C. albicans and E. faecalis, respectively. In each plate, four wells were filled with groups (n=10): Group-I: Nanocalcium hydroxide (NCH)+sterile distilled water, Group-II: NCH+Nanoparticle Clove, GroupIII: NCH+Nanoparticle Triphala, Group-IV: NCH+nanoparticle activated charcoal. The plates were incubated at 37°C, and zones of inhibition around the wells were measured on the first, third, and seventh day. DCT was evaluated in Colony Forming Units (CFUs)/ml by adding each bacterial suspension to four groups and inoculating on blood agar plates. One-way ANOVA test followed by Tukey’s post-hoc analysis was used to compare the mean Zone Of Inhibition (ZOI). Kruskal-Wallis Test followed by Mann-Whitney post-hoc test was used to compare the mean CFUs. Results: One-way ANOVA test showed that there was a significant difference in the mean ZOI between the four groups at p=0.005. The maximum mean ZOI against C. albicans was achieved by the combination of calcium hydroxide and clove with an average mean of 22.20±1.92 mm, 20±1.87 mm, and 17.20±2.28 mm on the 1st, 3rd, and 7th day, respectively. Calcium hydroxide with distilled water combination showed the highest mean ZOI against E. faecalis with an average mean of 18.20±0.84 mm on day 1, 17±1 mm on the 3rd and 7th day. The mean CFUs of E. faecalis and C. albicans showed a significant difference between the four groups at p<0.001. Conclusion: The addition of herbals to Calcium hydroxide increased anti-microbial activity against Candida albicans and Enterococcus faecalis.

Key genes of electron transfer, the nitrogen cycle and tetracycline removal in bioelectrochemical systems

BackgroundSoil microbial fuel cells (MFCs) can remove antibiotics and antibiotic resistance genes (ARGs) simultaneously, but their removal mechanism is unclear. In this study, metagenomic analysis was employed to reveal the functional genes involved in degradation, electron transfer and the nitrogen cycle in the soil MFC.ResultsThe results showed that the soil MFC effectively removed tetracycline in the overlapping area of the cathode and anode, which was 64% higher than that of the control. The ARGs abundance increased by 14% after tetracycline was added (54% of the amplified ARGs belonged to efflux pump genes), while the abundance decreased by 17% in the soil MFC. Five potential degraders of tetracycline were identified, especially the species Phenylobacterium zucineum, which could secrete the 4-hydroxyacetophenone monooxygenase encoded by EC 1.14.13.84 to catalyse deacylation or decarboxylation. Bacillus, Geobacter, Anaerolinea, Gemmatirosa kalamazoonesis and Steroidobacter denitrificans since ubiquinone reductase (encoded by EC 1.6.5.3), succinate dehydrogenase (EC 1.3.5.1), Coenzyme Q-cytochrome c reductase (EC 1.10.2.2), cytochrome-c oxidase (EC 1.9.3.1) and electron transfer flavoprotein-ubiquinone oxidoreductase (EC 1.5.5.1) served as complexes I, II, III, IV and ubiquinone, respectively, to accelerate electron transfer. Additionally, nitrogen metabolism-related gene abundance increased by 16% to support the microbial efficacy in the soil MFC, and especially EC 1.7.5.1, and coding the mutual conversion between nitrite and nitrate was obviously improved.ConclusionsThe soil MFC promoted functional bacterial growth, increased functional gene abundance (including nitrogen cycling, electron transfer, and biodegradation), and facilitated antibiotic and ARG removal. Therefore, soil MFCs have expansive prospects in the remediation of antibiotic-contaminated soil. This study provides insight into the biodegradation mechanism at the gene level in soil bioelectrochemical remediation.

Composite material consisting of microporous beta-TCP ceramic and alginate-dialdehyde-gelatin for controlled dual release of clindamycin and bone morphogenetic protein 2

The aim of this study was to produce a composite of microporous β-TCP filled with alginate-gelatin crosslinked hydrogel, clindamycin and bone morphogenetic protein (BMP-2) to prolong the drug-release behaviour for up to 28 days. The most promising alginate-di-aldehyde(ADA)-gelatin gel for drug release from microcapsules was used to fill microporous β-TCP ceramics under directional flow in a special loading chamber. Dual release of clindamycin and BMP-2 was measured on days 1, 2, 3, 6, 9, 14, 21 and 28 by high performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA). After release, the microbial efficacy of the clindamycin was checked and the biocompatibility of the composite was tested in cell culture. Clindamycin and the model substance FITC-protein A were released from microcapsules over 28 days. The clindamycin burst release was 43 ± 1%. For the loaded ceramics, a clindamycin release above the minimal inhibitory concentration (MIC) until day 9 and a burst release of 90.56 ± 2.96% were detected. BMP-2 was released from the loaded ceramics in low concentrations over 28 days. The release of active substances from β-TCP and hydrogel have already been extensively studied. Directional flow loading is a special procedure in which the ceramic could act as a stabilizer in the bone and, as a biodegradable system, enables a single-stage surgical procedure. Whether ADA-gelatin gel is suitable for this procedure as a more biodegradable alternative to pure alginate or whether a dual release is possible in this composite has not yet been investigated.Graphical

Deposition of Daldinia starbaeckii (ELF) functionalized silver nanoparticles on urinary catheter tube using chitosan polymer to prevent microbial biofilms formation during UTI infection.

Catheter-associated urinary tract infections (CAUTI) are the most common healthcare problem in hospitals. In this study, we isolated the Daldinia starbaeckii (An endolichenic fungus from Roccella montagnie) and its biomass extract were used to simultaneously synthesize and deposit DSFAgNPs on the inner and outer surfaces of the catheter tube using chitosan biopolymer via In-situ deposition method. Perfectly designed D. starbaeckii extract functionalized DSFAgNPs were characterized by UV spectroscopy, FTIR, SEM, EDS, TEM, and XRD. The microbial efficacy of DSFAgNPs & DSFAgNPs coated catheter (CTH3) was evaluated against eight human pathogenic gram (+ / -) ive strains and Candida albicans. Results indicated DSFAgNPs showed significant biological activity against both gram (+ / -) ive bacteria with an average MIC90 of 4µl/ml. The most promising activity was observed against Helicobacter pylori. When bacteria strains allow to grow with CTH3 we reported significant reduction in colony formation unit (CFU/ml) in broth culture assay with an average 70% inhibition. Further, antibiofilm activity of CTH3 against P. aeruginosa showed strong inhibition of biofilm formation (85%). The study explored an alternate approach for significantly prevent CAUTI among hospital patients. We isolated an endolichenic fungus from lichen Roccella montagnei. The molecular characterization of fungus identified as Daldinia starbaeckii (DSF). The DSF was cultured and its fungal biomass exudes were used to simultaneously construct DSF-AgNPs and its deposition on the catheter surface using biopolymer chitosan via In-situ deposition method. Further, antimicrobial and antibiofilm efficacy of DSF-AgNPs was checked against urinary catheter contaminating and human pathogenic bacterial strains. Based on our research, we determined that DSF-AgNPs coating on a urinary catheter through this method is a cost-effective, eco-friendly approach to prevent catheter contamination.

Comparative study of polymyxin B and colistin sulfate in the treatment of severe comorbid patients infected with CR-GNB

BackgroundWith the difficulties in choosing colistin sulfate and polymyxin B sulfate (PBS) for carbapenem-resistant gram-negative bacteria (CR-GNB), we compared the efficacy and safety of these two old polymyxins in treatment of critically ill patients infected with CR-GNB infection.MethodsOne hundred four patients infected with CR-GNB in ICU were retrospectively grouped by PBS (68 patients) or colistin sulfate (36 patients). Clinical efficacy including symptoms, inflammatory parameters, defervescence, prognosis and microbial efficacy were analyzed. Hepatotoxicity, nephrotoxicity, and hematotoxicity were evaluated by TBiL, ALT, AST, creatinine, and thrombocytes.ResultsDemographic characteristics between colistin sulfate and PBS were not significantly different. Most of the CR-GNB were cultured in respiratory tract (91.7% vs 86.8%), and almost all were polymyxin-sensitive (98.2% vs 100%, MIC ≤ 2 μg/ml). The microbial efficacy in colistin sulfate (57.1%) was significantly higher than PBS (30.8%) (p = 0.022), however, no significant difference in clinical success was seen in both groups (33.8% vs 41.7%), as well as mortality, defervescence, imaging remission, days in the hospital, microbial reinfections, and prognosis, and almost all patients defervesce within 7 days (95.6% vs 89.5%).ConclusionsBoth polymyxins can be administrated in critically ill patients infected with CR-GNB and colistin sulfate is superior to PBS in microbial clearance. These results highlight the necessity of identifying CR-GNB patients who may benefit from polymyxin and who are at higher risk of mortality.

Efficacy and mortality of ceftazidime/avibactam-based regimens in carbapenem-resistant Gram-negative bacteria infections: A retrospective multicenter observational study

ObjectivesLimited data on clinical and microbiological efficacy, patient mortality, and other associated factors are available for ceftazidime/avibactam (CAZ/AVI)-based regimens for carbapenem-resistant Gram-negative bacteria (CR-GNB). This study aimed to assess these issues retrospectively using multicenter data. MethodsThis multicenter study included CR-GNB infected patients treated with CAZ/AVI-based regimens for more than three days. Patient characteristics, bacterial culture reports, drug-sensitivity test results, and antibiotic use, including CAZ/AVI use, were extracted from the patient's clinical records. The clinical and microbiological efficacy of the combined drug regimen and patient mortality were evaluated according to corresponding definitions. Univariate and multivariate logistic regressions were performed to explore the efficacy and mortality-related factors. ResultsA total of 183 patients with CR-GNB infection were considered for the analysis according to the inclusion and exclusion criteria. After the treatment of CAZ/AVI-based regimens, the clinical efficacy was 75.4 %. The 7-day microbial efficacy and clearance rate after treatment were 43.7 % and 66.0 %, respectively. Moreover, 30-day all-cause and in-hospital mortality were 11.5 % and 14.2 %, respectively. Harboring renal dysfunction (creatinine clearance rate (CCR) of<20 mL/min), cardiovascular diseases, and digestive system diseases were independent risk factors for poor clinical efficacy of CAZ/AVI-based regimens. Bloodstream infection (BSI), patients with the adjusted doses of CAZ/AVI, and CAZ/AVI co-administration with carbapenem were independently associated factors of bacterial clearance by CAZ/AVI-based regimens. Age, total hospital stays, use of mechanical ventilation, and cumulative CAZ/AVI dose were independent factors associated with all-cause mortality. ConclusionCAZ/AVI was an effective drug in treating CR-GNB infection. CAZ/AVI that is mostly excreted by the kidney and is accumulated in renal impairment should be renally adjusted. Renal dysfunction and the adjusted dose of CAZ/AVI were associated with efficacy. Clinicians should individualize CAZ/AVI regimen and dose by the level of renal function to achieve optimal efficacy and survival. The efficacy of CAZ/AVI in the treatment of CR-GNB infection, as well as the implementation of individualized precision drug administration of CAZ/AVI according to patients’ different infection sites, renal function, bacterial types, bacterial resistance mechanisms, blood concentration monitoring and other conditions need to be further studied in multicenter.

A Comparative Evaluation of Antibacterial Efficacy of Moringa oleifera Leaf Extract, Octenidine Dihydrochloride, and Sodium Hypochlorite as Intracanal Irrigants against Enterococcus faecalis: An In Vitro Study.

The aim of this study is to investigate and compare the microbial efficacy of Moringa oleifera leaf extract, octenidine dihydrochloride (OCT), NaOCl, and their combinations as intracanal irrigants against Enterococcus faecalis. Sixty single-rooted mandibular premolars were decoronated followed by root canal preparation. Each root specimen was autoclaved, inoculated with E. faecalis, and incubated at 37°C for 48 hr. Then, the specimens were divided into six groups based on the irrigation solution used: 2.5% NaOCl (Group 1), 0.1% OCT (Group 2), M. oleifera leaves extract (Group 3), a combination of M. oleifera extract and 1.25% NaOCl (Group 4), a combination of M. oleifera extract and OCT (Group 5) and normal saline (Group 6). Microbial samples were taken from each root canal before (S1) and after (S2) irrigation and the bacterial viability was assessed using colony-forming units (CFU) on bile esculin agar plates. Comparing the number of CFU/ml before and after irrigation showed a significant reduction (P < 0.001) in all studied groups. Comparison between the CFU/ml after irrigation by NaOCl and each of the combination groups showed a significant difference. M. oleifera leaves extract and 0.1% OCT solutions have antibacterial effect against E. faecalis comparable to 2.5% NaOCl and might be used as root canal irrigants. The combination groups showed better antimicrobial activities than individual irrigants. However, further studies are required to investigate the biocompatibility and possible toxic effects of the tested irrigants.

Preliminary Study of the Bactericide Properties of Biodegradable Polymers (PLA) with Metal Additives for 3D Printing Applications

Plastic is a highly used material in various sectors. Due to its plentiful availability in the environment, microorganism surface contamination is a risk. The aim of this work is to achieve bactericidal capacity in plastics that reduces the microorganism's colonization risk and, consequently, reduces the chances of having an infection with E. coli and Listeria monocytogenes bacteria. Using polylactic acid (PLA) as the polymeric matrix, mixtures in concentrations of metal additive of ions of silver (Ag) R148 and S254 in 1% and 2% have been studied and manufactured. The materials are developed on an industrial scale through a process that proceeds as follows: (I) a mixture of polymer and additive in a double-screw compounder to obtain the compound in different concentrations, (II) the manufacture of filaments with a single-screw extruder, (III) 3D printing parts. Therefore, materials are evaluated in the form of powder, pellets and printed pieces to ensure their antibacterial effectiveness throughout the manufacturing process. The results of the research show antibacterial effectiveness for E. coli and Listeria monocytogenes of metal additives and polymeric compounds for all manufacturing phases on an industrial scale, with the effectiveness for additive R148 predominating at a concentration of 2%, demonstrating its microbial efficacy on surfaces with potential application in medicine.

Assessment of a novel, easy-to-implement, aerosolized H2O2 decontamination method for single-use filtering facepiece respirators in case of shortage

The COVID-19 pandemic has affected the world and caused a supply shortage of personal protection equipment, especially filtering facepiece respirators (FFP). This has increased the risk of many healthcare workers contracting SARS-CoV-2. Various strategies have been assessed to tackle these supply issues. In critical shortage scenarios, reusing single-use-designed respirators may be required. Thus, an easily applicable and reliable FFP2 (or alike) respirator decontamination method, allowing safe re-use of FFP2 respirators by healthcare personnel, has been developed and is presented in this study. A potent and gentle aerosolized hydrogen peroxide (12% wt) method was applied over 4 hr to decontaminate various brands of FFP2 respirators within a small common room, followed by adequate aeration and storage overnight. The microbial efficacy was tested on unused respirator pieces using spores of Geobacillus stearothermophilus. Further, decontamination effectiveness was tested on used respirators after one 12-hr shift by swabbing before and after the decontamination. The effects of up to ten decontamination cycles on the respirators’ functionality were evaluated using material properties, the structural integrity of the respirators, and fit tests with subjects. The suggested H2O2 decontamination procedure was proven to be (a) sufficiently potent (no microbial recovery, total inactivation of biological indicators as well as spore inoculum on critical respirator surfaces), (b) gentle as no significant damage to the respirator structural integrity and acceptable fit factors were observed, and (c) safe as no H2O2 residue were detected after the defined aeration and storage. Thus, this easy-to-implement and scalable method could overcome another severe respirator shortage, providing enough flexibility to draft safe, effective, and logistically simple crisis plans. However, as highlighted in this study, due to the wealth of design and material used in different models and brands of respirators, the decontamination process should be validated for each FFP respirator model before its field implementation.

Evaluation of antimicrobial efficacy of different hand sanitizers available in Thimphu, Bhutan

Introduction: Hand washing and the use of alcohol based hand-rub are two effective hand-hygiene procedures. Though the compliance to hand washing was relatively low, the COVID-19 pandemic situation has drastically increased the use of hand sanitizers. Thus, many hand sanitizer brands have entered the market and this study was taken up to assess the microbial efficacy of different types of hand sanitizers available in Thimphu. Methods: Ten gel based and ten liquid hand sanitizers were collected from various retail pharmacy shops in Thimphu during first quarter of 2020. Laboratory based experiment was performed using standard organism; Gram Negative Bacteria (GNB) Escherichia coli (American Type Culture Collection 25922) and Pseudomonas aurigenosa (American Type Culture Collection 27853), Gram Positive Bacteria (GPB) Staphylococcus aureus (American Type Culture Collection 25923) and a cocktail of GNB and GPC. The efficacy of hand sanitizer was assessed with the size of the Zone of Inhibition (ZoI). Results: The hand sanitizers were found to be effective against all strains of micro organism but with differentsize of ZoI. The maximum size of Zone of Inhibition was observed by sample N and Q (ZoI diameter 33.0±0.14mm) for American Type Culture Collection 25923. The Zone of Inhibition of liquid base hand sanitizers was significantly higher than that of gel base (p&lt;0.05). Conclusions: The study presents that liquid base alcohol based hand sanitizer is more efficient than the gel form.

Local production of alcohol-based hand rub to optimize hand hygiene facility in healthcare settings during COVID-19

Background: Hand hygiene (HH) remains arguably the most effective way to prevent healthcare-associated infections (HAIs) and ultimately improve the prospect of patient safety. Studies have shown that as many as 50%–70% of infections are transmitted through hands due to poor HH practices. HH with use of alcohol-based hand rub (ABHR) is preferred over handwashing with soap and water because of its wide microbial efficacy, time efficiency, and improved skin tolerance. It is also well known that ABHR can be used as an effective prevention measure during disease outbreaks. Before and during the COVID-19 pandemic, health facilities in Sierra Leone have been challenged with HH infrastructural problems such as lack of sinks with constant running water. Before Sierra Leone recorded its first case of COVID-19 in March 2020, the consumption of ABHR in the health facilities was estimated to be 24,000 L per year, which doubled during the COVID-19 pandemic. The demand for commercially available ABHR increased, leading to acute shortages. The estimated cost of the locally produced ABHR ~$2–3 per 500 mL, although it may cost up to $10 for 500 mL when buying imported ABHR products from the local market. Methods: All ingredients were procured locally, and ABHR production was based on WHO formula 1. The production was set for 12 months to cover the estimated annual consumption of ABHR, with periodic monitoring to ensure effective distribution and availability at the point of care. Analysis of assessment results in 12 hospitals from the pre-COVID-19 era (2019) to the COVID-19 era (2021) was performed based on the WHO IPC Assessment Framework (IPCAF) indicator. Results: With an average monthly production of 3,482 L, a total of 41,780 L ABHR was produced and packaged in branded 500-mL containers for distribution to healthcare facilities. This quantity exceeded the estimated demand for ABHR during the COVID-19 pandemic. The data show a considerable increase (from 25% to 44%) in the number of available and functioning HH stations with mainly locally produced ABHR. Results from the monitoring of 575 peripheral health units (PHUs) in 2021 also showed that &gt;67% of PHUs had HH facilities in all clinical areas and that the locally produced ABHR was used in 79% of these HH stations. Conclusions: Locally produced ABHR has shown to be a cost-effective and evidence-based intervention to optimize HH at the point of care. Therefore, localities are encouraged to undertake this realistic and sustainable approach to address issues of acute shortage of ABHR, especially during a global pandemic.Funding: NoneDisclosures: None

Mechanical Property, Thermal Stability and BioDegradability Studies on PLA based Bio-Nanocomposites derived from Agricultural Residues

Looking at the environmental hazards being posed by indiscriminate use of synthetic plastics, abundant research is being done to explore various bio-degradable polymers. In the present study, Cellulose Nano Fibers (CNFs) were extracted from Pineapple Crown using mechano chemical treatment, PLA was synthesized by Simultaneous Saccharification and Fermentation using cellulase enzyme on Acacia Arabica as substrate. Further, ZnO nanoparticles were synthesized by using different precursors. The biocomposite sheets of PLA, PLA+ 5%-20% CNFs, PLA+5% ZnO+5-20 % CNFs and PLA+10% ZnO+5-20 % CNFs were solvent casted. Microbial efficacy test was done using E.coli and with inclusion of ZnO nanoparticles the microbial resistance has increased. Noteworthy vibration band of the sheets were observed in the wavelength range of 3700 to 2800 cm-1 from the FTIR analysis, which shows that there is only a physical interaction rather than chemical. The crystallinity increased for initial concentration, but was similar to the neat PLA. Significant increase in tensile strength and maximum elongation at break was observed in PLA + 5% ZnO + 10% CNFs sheet. Sheets were allowed to degrade naturally and significant weight loss was observed after 120 days with maximum reduction of 38.4 %. Morphological analysis through SEM revealed the uniform distribution of fillers in the polymer matrix. TGA studies have shown that the degradation temperatures were in the range of 320-405oC. The thermal stability decreased with the increase in ZnO concentration. The results have shown a promising and sustainable use in various applications in view of microbial resistance and bio-degradability.

Antibacterial Treatment of Selected High-Touch Objects and Surfaces within Provision of Nursing Care in Terms of Prevention of Healthcare-Associated Infections.

Prevention of healthcare-associated infections is an important part of providing nursing care. High-touch objects and surfaces that can be contaminated with various bacteria are matters of concern. The possibility of reducing contamination is the use of antibacterial and hydrophobic nanolayers. The aim of this study was to determine, by means of an experimental method, the microbial efficacy of applied antibacterial and hydrophobic nanolayers on high-touch objects and surfaces used in nursing practice in a regional hospital in the Czech Republic. The results show that the antibacterial efficacy of the applied nanolayer was not demonstrated. Furthermore, the results show that selected objects and surfaces can always be contaminated by bacterial agents in about 1/3 of cases. It is mainly contamination with nonpathogenic bacteria; however, the presence of pathogenic bacteria, such as Staphylococcus aureus, has also been detected. The results of this study pinpoint the importance of following the basic rules for the use of decontaminated objects and surfaces used to provide healthcare.

Synthesis and characterization of azobenzene derivatives and azobenzene-imidazolium conjugates with selective antimicrobial potential

Five new non-fluorinated and fluorinated azo derivatives, as well as a new series containing five azo-imidazolium conjugates of varying alkyl chain length in the imidazolium head group were prepared and characterized using FTIR and NMR spectroscopy, and elemental microanalysis. Antimicrobial activities of these compounds against pathogenic Gram positive bacterium Staphylococcus aureus and Gram negative bacteria Escherichia coli, Salmonella enterica serovar Typhimurium, as well as yeasts Candida albicans and Saccharomyces cerevisiae were evaluated using the disc diffusion method. The azo derivatives and their imidazolium conjugates were selectively active against the tested microorganisms with zone of inhibition diameters ranging from 10mm-21mm. Their biological efficacy was dependent on the chain length and level of fluorine substitution. The presence of long alkyl chains is essential for the azo derivatives to exhibit microbial efficacy. Active azo-imidazolium conjugates on Staphylococcus aureus contained 16 and 18 carbons in the alkyl chains while Gram negative strains exhibited a cut-off effect at chain length C16. Difference in antimicrobial behavior of the azo derivatives could be due to the different cell wall between the Gram positive and negative bacteria. Fluorination had no effect on the activity against E. coli and Salmonella. However, a clear correlation between the level of fluorine substitution and the antimicrobial activity against Staphylococcus aureus, Candida albicans and Saccharomyces cerevisiae was observed.