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The development of low-cost, highly effective, environmentally friendly, multi-functional bio-cidal substances has become a top priority in the current scenario. This study aimed to create low-cost materials, such as green-engineered magnesium oxide (GEMgO) and chitosan-coated magnesium oxide (GECsMgO) nanoparticles (NPs), using Chara zeylanica Klein ex Willd extract as a reducing agent. The X-ray diffraction results confirmed the cubic face-centered structure of the GEMgO and GECsMgO NPs. The field emission scanning electron microscopy and transmission electron microscopy results showed that GEMgO and GECsMgO NPs exhibit a spherical structure and nanoflakes with spherical structures, respectively. The Mg–O stretching frequencies were measured at 779 and 456 cm−1 for GEMgO and 543 cm−1 for GECsMgO NPs in the Fourier-transform infrared spectra. The oxygen vacancies responsible for the biocidal activities of GEMgO and GEC-MgO NPs were observed in their photoluminescence spectra at 501 and 520 nm and at 506 and 524 nm, respectively. The antioxidant activity of GEMgO and GECsMgO NPs was investigated using a DPPH assay. The GECsMgO NPs exhibited higher scavenging activity than the GEMgO NPs. Antibacterial studies on gram-negative bacteria treated with GEMgO and GECsMgO NPs showed that GECsMgO NPs exhibited the highest antibacterial activity. The ultrastructural morphological results of E. coli showed that GECsMgO NPs can damage it better than GEMgO NPs. An MTT assay determined that GEC-MgO NPs had better anticancer properties than GEMgO NPs when tested against a blood cancer cell line (MOLT-7). Fibroblast L929 cell toxicity tests showed that GEC-MgO NPs were less toxic than GEMgO NPs. In the future, GECsMgO NPs can be used as biocidal agents in clinical and industrial applications. • GEMgO and GECsMgO nanoparticles were synthesized using the Green Engineering method. • GECsMgO NPs exhibit higher antibacterial activity against gram-negative bacteria than GEMgO NPs. • GECsMgO NPs exhibit potential anticancer activity against blood cancer cell lines. • GECsMgO NPs were less harmful to fibroblast cells than GEMgO NPs. [ABSTRACT FROM AUTHOR]

• Wider variety of artefacts needs to be conserved. • NPs based coating have the potency to replace the traditional coating materials. • The NPs improved the photo-catalysis, hydrophobicity and antibacterial properties. The progression in the use of nanostructured metal oxide or metal oxide based polymeric nanocomposite for the conservation and refurbishment of cultural heritage are presented in this review. Starting from the definition of nanoparticles, their major synthesis techniques, the paper briefly describes the utilization of various metal oxide nanoparticles and metal oxide based polymeric nanocomposite coatings and their surface protection functions including self-cleaning, increased photocatalytic activity, biocidal effects, UV blocking properties and compatibility with the different types of substrates including wood, stones, bricks and paper focussing on their potential usage and their application in the arena of remediation of cultural heritage. [Display omitted] [ABSTRACT FROM AUTHOR]

The use of copper as an antimicrobial agent has a long history and has gained renewed interest in the context of the COVID-19 pandemic. In this study, the authors investigated the antimicrobial properties of an alloy composed of copper with a small percentage of silver (Cu-0.03% wt.Ag). The alloy was tested against various pathogens, including Escherichia coli, Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa, and the H1N1 virus, using contact exposure tests. Results showed that the alloy was capable of inactivating these pathogens in two hours or less, indicating its strong antimicrobial activity. Electrochemical measurements were also performed, revealing that the small addition of silver to copper promoted a higher resistance to corrosion and shifted the formation of copper ions to higher potentials. This shift led to a slow but continuous release of Cu2+ ions, which have high biocidal activity. These findings show that the addition of small amounts of silver to copper can enhance its biocidal properties and improve its effectiveness as an antimicrobial material. [ABSTRACT FROM AUTHOR]

IntroductionRecent work demonstrating reduction of aerosolized contamination via a wipe-down procedure using common veterinary antiseptics offers promise regarding health concerns associated with cross-contamination from working canines to humans. While mechanical reduction can be achieved via a wipe-down procedure, the biocidal impact on flora within the exterior coat is unknown.MethodologyThis study assessed the biocidal impact of antiseptics on the exterior bacterial community of the canine. Lint-free towels were saturated with 2% chlorhexidine gluconate scrub, or 7.5% povidone-iodine scrub diluted at a 1:4 ratio. Treatments were rotated across the dorsal aspect of kennel housed Foxhounds (n = 30). Sterile swabs were collected in triplicate prior to, and following wipe down, stored in Amies solution at 4°C, plated onto nutrient agar and reduction in colony forming units (CFU) was measured across both treatments. Statistical analysis utilizing PROC GLM examined effects of treatment (p ≤ 0.05). Molecular analysis of the 16S rRNA gene was completed for 3 hounds.ResultsReduction in CFU was measured (p

The present study reports on the biogenic synthesis of a copper-based biocidal material through the fermentation of gruel, a traditional non-alcoholic beverage. This process may involve a bio-beneficiation mechanism, in which the indigenous microorganisms in the ferment interact with the material. X-ray diffraction analysis confirmed the powder's crystalline copper composition. Fourier-transform infrared spectroscopy revealed the crucial role of organic acids in the capping process. Transmission electron microscopy, ultraviolet-visible spectroscopy, and antimicrobial susceptibility tests were conducted to characterize the powder. Furthermore, the biocidal material was combined with the anticancer drug curcumin to explore its additional anti-proliferative effects, including apoptosis, on human hepatocellular carcinoma cell lines in vitro. These findings highlight the potential of this biogenic copper material as a promising candidate for biomedical applications. [ABSTRACT FROM AUTHOR]

Aquaculture has an important role in the global food market and aquatic organisms are a great reservoir of wholesome nourishment concomitantly addressing the issues of malnutrition in developing nations. The increased fish demand calls for exploring new avenues in aquaculture that include strategies for better aquaculture water management, suitable aquafeed that facilitates fish health and are rich in antioxidants, antimicrobials to ensure less motility and accelerated productivity. Microalgae possess all the qualities that qualify them to ideal sustainable aquafeed as they are rich in protein and carbohydrate, easily digestible, appetizing, and provide essential amino acids, pigments, carotenoids, vitamins, polysaccharides, and omega-3 fatty acids. The growth of algae in aquaculture wastewater leads to efficient remediation preventing eutrophication and the nutrients present in the water generate algal biomass, which can act as biocontrol agents to combat the fish pathogenic microbes like bacteria, fungi, and viruses. This review highlights the multifaceted role of microalgae in aquaculture. Exploring promising microalgae strains for aquaculture can provide viable, sustainable, and cost-effective solutions including better aquafeeds promoting aquatic health and efficiently remediating the diverse aquaculture wastewater. [ABSTRACT FROM AUTHOR]

The unprecedented cases of antimicrobial resistance and scarcity of effective antibiotics against resistant strains demand the development of proficient antibiotics and their stewardship. The antibiotic carriers and the adjuvants that can counteract the resistance mechanism and revive the activity of existing antibiotics are considered as one of the promising tools to fight against antimicrobial resistance and its consequences. Herein, we demonstrated the development of sulfonium- and lauryl amine-conjugated BSA protein nanoparticles (PNPs) with inherent antimicrobial activities that embraced the benefits of biocompatibility and antibiotic-carrying capability. The PNPs showed encapsulation and controlled release profiles of clinically approved antibiotics. The antibiotic-encapsulated PNPs exhibited synergistic antimicrobial activity against Gram-negative, Gram-positive, and drug-resistant bacterial strains, which could reduce the effective doses of antibiotics and exposure to other microbial strains. Subsequent studies showed that the PNPs were capable enough to breach the sturdy biofilm barriers of the bacterial strains, and at a minimum inhibitory concentration, the biofilm lost its viability. The antibiotic-encapsulated PNPs also lower the drug resistance ability of commercial antibiotics. The mechanistic studies revealed that the antibacterial activity of the PNPs follows a membrane-directed pathway. The PNPs showed negligible toxicity against erythrocytes. Interestingly, lauryl amine and sulfonium-conjugated albumin protein (R-BSA-S) gives protection against Staphylococcus aureus biofilm-associated infection in albino laboratory-bred (BALB/c) mice, as appeared from the decrease in the colony forming unit (CFU) count and histological changes in the liver and spleen. Thus, the synthesized antimicrobial carrier molecule revitalizes the activity of the antibiotics and is a cost-effective strategy. [ABSTRACT FROM AUTHOR]

Assay of enzyme activity generates accurate biochemical data for evaluating microbial activities. Assay of dehydrogenase activity of test organisms eliminates underestimation of viable cells and lack of homogeneity in distribution which characterize cultural methods. In this study the antibacterial and antifungal activities of ethanol leaf extract of Jatropha tanjorensis (ELJT) was investigated against Staphylococcus aureus and Candida albicans using the inhibition of total dehydrogenase activity (DHA) method. Inhibition of DHA of the test organisms by ELJT was determined and compared to standard antibiotic (Ciprofloxacin). Total DHA was assayed using 2,3,5-triphenyltetrazolium chloride as artificial electron acceptor which was reduced to redcoloured triphenylformazan (TPF). Pure cultures of Staphylococcus and Candida species were exposed to varied concentrations of ELJT (0 - 2000 µg/ml). ELJT exhibited concentration dependent response against tested organisms. Total DHA was progressively inhibited mostly in a logistic dose-response fashion in the test organism by the extracts and standard drug. The extract and standard drug achieved 80% inhibition within the tested doses (0-2000 µg/ml). Threshold inhibitory concentrations (IC50) and IC80 for ELJT against S. aureus were 102.350 ± 6.14 µg/ml, and 440.930 ±26.46 µg/ml respectively, while ciprofloxacin showed 100% inhibition at 447.911 ± 26.87 µg/ml. The IC50 and IC80 for ELJT against C. albicans were 26.821 ± 1.34 µg/ml, and 58.895 ± 4.12 µg/ml respectively, while ciprofloxacin showed 80% inhibition at 5.742 ± 0.40 µg/ml. These results indicate J. tanjorensis extract as a viable antimicrobial source, useful in complimentary management and treatment of infections caused by S. aureus and C. albicans. [ABSTRACT FROM AUTHOR]

Nanoparticles have drawn significant attention in recent years, owing to their unique electrical, optical, biocidal, and catalytic properties. The present study reports an environment friendly, green approach for silver nanoparticles (AgNPs) synthesis using bacterial yellow color pigment, xanthomonadin (XP) derived from Xanthomonas sp. After exposing the reaction mixture to sunlight, a visible colour shift and spectrophotometric measurement proved that nanosized silver particles (XP-AgNPs) were being synthesized by xanthomonadin. The size of XP–AgNPs was in the range between 30 and 100 nm, with the spherical shaped particles. The XP–AgNPs showed excellent biocidal activity against representative Gram positive and Gram negative organisms i.e. Staphylococcus aureus, B. subtilis and Pseudomonas aeruginosa, Escherichia coli. In addition, using standard assays, the photo-protecting/SPF enhancement of commercial sunscreens and DPPH radical scavenging activity of XP, and XP-AgNPs were evaluated. As a result, adding 4 % w/w xanthomonadin in commercial sunscreens have original SPFs 4 and 10 increases by 271 % and 85.2 %, respectively. XP and XP-AgNPs showed significant antioxidant activities with the IC50 values of 46.21 µg/mL and 21.62 µg/mL, respectively. In conclusion, xanthomonadin mediated silver nanomaterial with photo protecting, antioxidant and biocidal potential has been reported.

This study was carried out to investigate the effect of plant extracts, African pepper fruit (Dennettia tripetala) and Ginger (Zingiber officinale) on seed borne fungal pathogens of Watermelon (Citrullus lanatas) seeds. Watermelon seeds were extracted for seed health test using blotter paper method. The antifungal effects of ethanol and acetone extracts of the two plant extracts and synthetic fungicide were studied under in- vitro experiment against the seed borne fungal pathogen of Watermelon at 0%, 50% and 75%. It was a 3x3 factorial experiment at 5% Probability level laid out in a Completely Randomized Design experiment with three replications Ninety percent germination was obtained in the germination and seed health test of Watermelon seeds. Seed borne fungal pathogen (Aspergillus spp. and Fusarium spp.) were identified. The potential of these organisms for pathogenicity were tested using Kock's postulate. The result of the pathogenicity test showed that Fusarium spp. was pathogenic. All plant extracts and Benlate inhibited the fungus (Fusarium moniliforme) in culture. The inhibition was also greater as concentration increased from 50% to 75%. It was also observed that ethanol extraction solvent did better than acetone. Generally, Dennettia tripetala extract performed better than Zingiber officinale. It could therefore be recommended that the two plant extracts used in this investigation which were very effective in the control of Fusarium moniliforme of watermelon could be an alternative to the synthetic fungicide. It could also be suggested that further studies be carried out to isolate, identify, characterize and standardize the bioactive components of these phytochemicals in a bid to commercializing their production. [ABSTRACT FROM AUTHOR]

Reusing source-separated urine as fertiliser enhances wastewater circularity, but further concentration is needed. Reverse osmosis (RO) is a promising option due to its low energy consumption but is susceptible to biofouling. Free ammonia in hydrolysed urine (HU) can be a biocidal agent at concentrations reached in RO concentrates. This study investigated the biocidal effects of concentrated free ammonia in concentrated HU and the feasibility of using it to reduce RO biofouling. Hydrolysed urine was pre-concentrated at different volume reduction factors (VRFs) (1.0, 1.7, 2.3 and 3.0) and was recirculated through a RO system for seven days. Using 3.0 VRF HU as feed, the RO permeate flux decline was 67 % lower than 1.0 VRF HU. The number of bacterial cells on the RO membrane exposed to 3.0 VRF HU was four orders of magnitude lower than 1.0 VRF HU. The dead bacteria fraction increased from 1 % with 1.0 VRF HU to 68 % with 3.0 VRF HU. The mass of organic foulants was reduced by 98 % with 3.0 VRF HU compared to 1.0 VRF HU. This study shows free ammonia in 3.0× concentrated HU is sufficient to reduce fouling in RO, which can potentially reduce the operational costs. [Display omitted] • Free ammonia concentration in hydrolysed urine (HU) increased with the increase of VRF. • Free ammonia in 3× concentrated HU reduces the fractional loss of water flux by 67 %. • Free ammonia in concentrated HU increased dead cell fraction from 1 % to 68 % in the biofouling layer. • The mass of organic foulants decreased with the increase of free ammonia concentration. • Increased free ammonia concentration has no obvious effect on inorganic fouling. [ABSTRACT FROM AUTHOR]

Community-associated and hospital-acquired infections caused by bacteria continue to yield major global challenges to human health. Bacterial contamination on abiotic surfaces is largely spread via high-touch surfaces and contemporary standard disinfection practices show limited efficacy, resulting in unsatisfactory therapeutic outcomes. New strategies that offer non-specific and broad protection are urgently needed. Herein, we report our novel ceria-silver nanozyme engineered at a molar ratio of 5:1 and with a higher trivalent (Ce3+) surface fraction. Our results reveal potent levels of surface catalytic activity on both wet and dry surfaces, with rapid, and complete eradication of Pseudomonas aeruginosa , Staphylococcus aureus , and methicillin resistant S. aureus , in both planktonic and biofilm form. Preferential electrostatic adherence of anionic bacteria to the cationic nanozyme surface leads to a catastrophic loss in both aerobic and anaerobic respiration, DNA damage, osmodysregulation, and finally, programmed bacterial lysis. Our data reveal several unique mechanistic avenues of synergistic ceria-Ag efficacy. Ag potentially increases the presence of Ce3+ sites at the ceria-Ag interface, thereby facilitating the formation of harmful H 2 O 2 , followed by likely permeation across the cell wall. Further, a weakened Ag-induced Ce–O bond may drive electron transfer from the E c band to O 2 , thereby further facilitating the selective reduction of O 2 toward H 2 O 2 formation. Ag destabilizes the surface adsorption of molecular H 2 O 2 , potentially leading to higher concentrations of free H 2 O 2 adjacent to bacteria. To this end, our results show that H 2 O 2 and/or NO/NO 2 −/NO 3 − are the key liberators of antibacterial activity, with a limited immediate role being offered by nanozyme-induced ROS including O 2 •- and OH•, and likely other light-activated radicals. A mini-pilot proof-of-concept study performed in a pediatric dental clinic setting confirms residual, and continual nanozyme antibacterial efficacy over a 28-day period. These findings open a new approach to alleviate infections caused by bacteria for use on high-touch hard surfaces. o Bacteria continue to yield major global challenges to human health.o A novel ceria-silver nanozyme engineered at a molar ratio of 5:1 and with a higher trivalent (Ce3+) surface fraction delivers superior catalytic activity.o The unique synergistic material formulation potently eradicates multispecies inoculations after repeated surface rechallenges.o The key liberator of antibacterial nanozyme activity is hydrogen peroxide and not reactive oxygen species formation. [Display omitted] [ABSTRACT FROM AUTHOR]

Plants have been used as medicines in the treatment of diseases from the past to present. In this research, the anti-microbial effects of aqueous and methanolic extracts of Erythrostemon gilliesii were studied. For this purpose, fresh flowers were ground and then macerated in methanol 100% and water overnight. After the evaporation of solvents, anti-microbial activities of the concentrated extracts were evaluated by the well-diffusion method on Klebsiella pneumoniae, Pseudomonas aeroginosa, Methicilin resistance, Staphylococcus aureus, Bacillus subtilis and Candida albicans. The results showed that the extracts were effective on different bacteria and yeasts. In order to determine the minimum inhibitory concentration (MIC) and minimum biocidal concentration (MBC), anti-microbial tests were performed in micro-plates. Subsequently, the results indicated that the extracts were stable at different temperatures. The aqueous and methanolic extracts of the flowers of E. gilliesii had exhibited anti-microbial effects against important infectious microbes and could be introduced as an excellent source for anti-microbial agents.

Biocidal activity of Vernonia amygdalina was assessed on Rhipicephalus appendiculatus ticks responsible for livestock diseases in North and South-Kivu provinces. In vitro trials were conducted in the laboratory of Lwiro Research Center for Natural Sciences to determine the lethal dose for different days after ticks contact with extracts. Five different dosages of 1.25, 2.5, 5, 10, 20 g/mL were evaluated. Water was considered as positive control and Batycol as negative control. The phytochemical screening of extracts of Vernonia amygdalina plant shows that this plant contains several substances responsible for acaricidal activity, mainly saponins, terpenoids, steroids and tannins. The experiment shows a mortality rate that varies with the concentration of the extracts; the most fatal is 20 g/mL and decreases with exposure time. The aqueous extracts showed a progressive decrease in mortality compared to ethanol extracts. This is due to the dissolution of the substances responsible for this insecticidal activity. The study recommends the application of aqueous extracts of Vernonia amygdalina in the fight against cattle ticks. Indeed, this is a natural insecticide available and easier to prepare, non-toxic to humans and is rapidly degraded in the environment.

ABSTRACT: Brazil has one of the largest commercial cattle herds in the world, which naturally coexist with an enormous number of parasitic species. Southern cattle tick, Rhipicephalus (Boophilus) microplus, is among these species, interfering with animal productivity and causing losses to the beef and dairy cattle sector. The use of chemical acaricides in the control of this mite has resulted in the emergence of resistant populations. In this sense, alternative control measures using plants as sources of botanical acaricides have shown to be effective. Eugenia pyriformis Cambess is a Brazilian plant with antioxidant and antimicrobial activity; however, there are no reports on its acaricidal activity in the literature. The present study aimed to evaluate the acaricidal and larvicidal potential of E. pyriformis leaf essential oil (EO) on southern cattle tick at different stages of the reproductive cycle. E. pyriformis leaves were collected and dried, and had their EO extracted by hydrodistillation (3h) using a modified Clevenger apparatus. Chemical analysis was performed by gas chromatography coupled with mass spectrometry (GC/MS), and 32 compounds belonging to the sesquiterpene class were identified: hydrocarbons (17.98%) and oxygenated forms (81.96%), with spathulenol (43.65%) and caryophyllene oxide (12.17%) as the most common. The EO was evaluated by the Adult Immersion Test at the concentrations (500.00 to 3.12mg/mL) in which the following parameters were measured: mortality of females (%), hatchability of eggs (%), and product efficiency (%). Larvae were assessed by the Larval Packet Test at concentrations ranging from 25.00 to 0.00004mg/mL. Lethal concentrations (LC) required for killing 50 and 99.9% of adult females and larvae were determined using Probit analysis. LC50 and LC99.9 of EO were 0.06 and 24.60mg/mL and 1,208.80 and 2,538mg/mL for larvae and adult females, respectively. Action of the EO in the free-living cycle of R. (B.) microplus larvae was another parameter assessed. To this end, the larvae were deposited in pots containing Brachiaria decumbens and, after migration to the leaf apex, a solution containing LC99.9 (24.60mg/mL) of the EO was sprayed. After 24h, 72.25% of the larvae had died, indicating stability of the EO when subjected to uncontrolled temperature and humidity conditions. The mechanism of action through which the EO killed the larvae and adult females was investigated by the Bioautographic Method, which showed inhibition of 3.15mg/mL of the EO on the acetylcholinesterase (AChE) enzyme. The results found in the present experiment indicate that E. pyriformis essential oil is an alternative in the control of southern cattle tick in the larval (parasitic) and free-living cycle (non-parasitic) stages under field conditions.

Iodine pentoxide (I 2 O 5) based nanothermites are one of the most promising candidates for biocidal energetic materials due to superior reactivity and high iodine content. However, the tunability of nanothermites, which is important for biocidal performance, has not been fully exploited for I 2 O 5 based nanothermites. In this work, I 2 O 5 with various fuels (Al, Ti, Si) and their mixtures (i.e., a ternary system) have been investigated. The reactivity and flame temperature were evaluated by a pressure cell coupled with a spectrometer. Temperature-Jump time-of-flight mass spectrometry (T-Jump TOFMS) was used to probe the reaction mechanism and iodine release behavior, along with a high-speed camera to capture the ignition event. I 2 O 5 showed distinct reactivity with different fuels. As a result, by varying the fuel composition of ternary systems, the combustion properties can be tuned. Rapid heating experiments revealed that the reaction initiation was shifted from gas phase dominated to condensed phase dominated mechanism after introducing Ti or Si into Al/I 2 O 5 system. Further analysis of the ternary systems found that the energy release rate correlates with burn time instead of flame temperature. This study shows an approach to tune the reactivity and energy release rate of I 2 O 5 based nanothermites without compromising the energy density. [ABSTRACT FROM AUTHOR]

Surface-modified Ag/TiO 2 photocatalysts with enhanced activity under visible light and biocidal properties have been produced through a two-stage method involving the functionalization of TiO 2 nanoparticles(NPs) with –SH or –NH terminated alkoxysilanes and deposition of AgNPs. The functionalization process increased the yield of the Ag deposition and promoted a more homogeneous distribution of the Ag over the TiO 2 surface. The highest stability, homogeneity and visible range absorption was achieved by –NH functionalization. However, the modification with –SH groups alters the size of the AgNPs and decreases the effectiveness due to formation of Ag 2 S. The increased absorption in the visible spectrum accelerated the organic dye degradation under solar light, although aggregation processes affected their effectiveness under UV-A. The incorporation of AgNPs allowed for the elimination of phototrophic microorganisms under white light at very low Ag concentrations whereas TiO 2 and –SH functionalized Ag/TiO 2 showed no biocidal activity. [Display omitted] [ABSTRACT FROM AUTHOR]

A biocidal product in gel form containing 0.05% fipronil active substance was used for pest control in the habitat of thirteen Squirrel Monkey (Saimiri sciureus) in a zoo. Following the application, sudden death was observed in three primates. Routine bacteriological, histopathological and toxicological analyses on one cadaver and tissue samples from the cadaver did not produce any pathogenic agent, pesticide and any pathognomonic findings. In an attempt to investigate the presence of known fipronil intoxication biomarkers, fipronil and fipronil sulfone, we applied modified QuEChERS extraction processes on tissue samples and determined the fipronil and fipronil sulfone levels as 27.1-3.5 µg/kg in cutaneous tissue and 13.8-47.2 µg/kg in brain tissue, respectively, by using UHPLC Q-Orbitrap Mass Spectrometer. In the light of the anamnesis, necropsy, microbiology and histopathology results, and after evaluating the presence of fipronil-fipronil sulfone in tissues, we considered that the deaths could have resulted from acute fipronil toxicity due to species-specific active substance susceptibility. [ABSTRACT FROM AUTHOR]

Natural compounds of botanical origin are increasingly being investigated for the development of novel biocides. Intensive use of synthetic biocides and the confined array of chemical classes in use has led to the buildup of unwanted residues and to parasites' adaptive responses and resistance. Meanwhile, the geographic and host ranges of arthropod vectors and vector-borne diseases are broadening. In an effort to develop "friendly" biocidal compounds for the environment and human health, plant secondary metabolites originating in a number of botanical families could be engaged. This mini-review compiles the recently available knowledge on plant secondary metabolites exhibiting biocidal properties and provides a brief overview on their activity against arthropods with a focus on toxic and repellent properties. The selected examples show that it is valuable to consider plants as a promising source for new products development to support the fight against arthropods related to human health. Finally, we outline the biocides regulatory framework in the European Union (EU) and pinpoint some issues of concern regarding the development of low risk biocides. Plant secondary metabolites acting against arthropods of medical importance [ABSTRACT FROM AUTHOR]

Most commercially available disinfectants cause serious health side effects. This study investigates controlled carbonation of Ca (OH) 2 by mixing with dry ice and the use of the resultant particles as a more health friendly antimicrobial agent. In one mixing scheme, alternate layering of Ca (OH) 2 and dry ice is used with no additional mixing, while in another a Hamilton Beach mixer is utilized. X – ray diffraction confirmed the identity of the resultant particles and thermogravimetry measured their bulk composition. Fourier transform infrared spectroscopy displayed different surface composition than Ca (OH) 2 suggesting a core – shell structured product. Commercial Ca (OH) 2 − CaCO 3 core – shell (CSCC) particles prepared under quiescent conditions and the particles prepared in this work displayed different extent of aggregated structures, despite the different mixing strategies. Thicker Ca CO 3 shell and CSCC particle aggregation corresponded to higher content of Ca CO 3 as estimated by acid/base titration. The antibacterial activity of the CSCC particles was evaluated using a novel strategy where cells are mixed with a fixed density of particles as a slurry. Both gram – negative; namely P.aeruginosa and E.coli , and gram – positive; namely S.aureus , bacteria were tested. The results confirmed the superior antibacterial properties of the in – house prepared CSCC particles, where at least 2 times more effective particles than Ca (OH) 2 and commercial particles were reported against gram-positive bacteria. The antibacterial properties of the particles were correlated to their morphology. [Display omitted] ● Controlled carbonation of Ca (OH) 2 to form core – shell Ca (OH) 2 − Ca CO 3 is achieved. ● The product is more health friendly antimicrobial agent. ● Thicker CaCO 3 shell and aggregation corresponded to less antibacterial efficacy. ● The CaCO 3 shell prolonged the biocidal activity of the core-shell particles. [ABSTRACT FROM AUTHOR]

The antimicrobial effect of copper (Cu) as well as its potentiality to reduce healthcare-associated infections is well recognized. In this study, a twin wire arc spray gun has been used to produce antibacterial copper coatings on stainless-steel (316L) surfaces. The thickness of coating was 120 ± 30 μm in average. In parallel, series of coating formation simulations were made using Comsol Multiphysics. The coating morphology was examined by scanning electron microscope (SEM) and its structure determined by x-ray diffraction (XRD). Surface roughness measurements were carried out on as-sprayed and polished surfaces by using a 3-D Profilometer. The coating antibacterial efficacy has been investigated considering standard and clinically isolated cultures such as standard ATCC 25922 Escherichia coli (E. coli), standard ATCC 29213 Staphylococcus Aureus (Staph. Aureus), clinically isolated Pseudomonas aeruginosa, Vancomycin-resistant Enterococcus (VRE) and Methicillin-resistant Staphylococcus aureus (MRSA). The predictions of simulations matched with the monitored data with an error below 10%. The coatings exhibited excellent antibacterial properties for all the pathogen types used. [ABSTRACT FROM AUTHOR]

Abstract Energetic materials with a high iodine content and tunable reactivity are desirable for application as a biocidal agent. In this paper, aluminum/polyvinylidene fluoride (Al/PVDF) composites with different iodine content were prepared by an electrospray deposition method. Most of the iodine in the films are found to be fixed by PVDF and aluminum, which is released at 250 °C and 450 °C respectively. The heat release and burning rate of the iodine-containing films decreases with the increase of iodine content. With an iodine content of ≥40 wt.%, the film did not propagate. However, when fabricated in a laminate structure the threshold for iodine loading to sustain propagation increased to 67 wt.%. Evaluation of several multi-layered structured films indicated that an optimum single layer thickness of ∼25 µm produced the fastest reaction velocity, with loadings of up to 67 wt.% iodine. The thermal decomposition and oxidation of the laminated Al/PVDF films are also investigated. It appears thus that iodine which acts as a reaction retardant can be loaded in higher concentrations if it is physically separated from the primary energetic. In so doing, the primary energetic can maintain a continuous ignition threshold to propagate and enable the heat released from reaction to evolve gas phase iodine. [ABSTRACT FROM AUTHOR]

Biocidal properties of ultrafine, cysteamine stabilized silver nanoparticles (AgNPs) are reported. The membrane-bound activity of the AgNPs was validated by performing the calcofluor white staining method followed by an in vitro quantification of chitin. The results verified the development of stress response in fungal cells leading to their clumping and eventually, as confirmed by propidium iodide staining assay, their death. Scanning electron microscope (SEM) imaging further confirms the development of stress environment around fungal cell wall in the presence of test AgNPs followed by a loss of cell viability. [ABSTRACT FROM AUTHOR]

Innovations in the nanotechnological arena have paved a path leading to nano-revolution, which has most recently unfurled the role of plants in the biogenic synthesis of nanoparticles. Though synthesis of nanoparticles can be accomplished through physical and chemical techniques, biological course of synthesis has proficiently proved competent over other techniques. The problem of evolving multidrug resistant bacteria, due to irrational use of antibiotics, makes the biogenically synthesized nanoparticles attractive, due to their promising efficacy with negligible side effects. Consequently, the nanoparticles becoming better substitutes for conventional treatment besides overcoming all the limitations. Nanoparticles have great stability and potent antibacterial activity. The uniqueness lies in their size (10 and 500 nm) and dimension offers these particles to dynamically communicate with biomolecules on the cell surfaces and within the cells, so proficiently to decode and designate various biochemical and physiochemical properties of the cells. The present review aims to recapitulate various emerging efforts in the biogenic synthesis of nanoparticles, most significantly their unique mechanisms of action with different approaches as well as the factors that may add up to their antimicrobial activity. [ABSTRACT FROM AUTHOR]

Purpose: Contact lens (CL) wear is a risk factor for the acquisition of microbial keratitis. Accordingly, compliance to manufacturers' recommended hygiene and disinfection procedures are vital to safe (CL) use. In this study we evaluated a novel povidone-iodine (PI) (CL) disinfection system (cleadew, Ophtecs Corporation, Japan) against a range of bacterial, fungal and Acanthamoeba.Methods: Antimicrobial assays were conducted according to ISO 14729 using the recommended strains of bacteria and fungi, with and without the presence of organic soil. Regrowth of bacteria and fungi in the disinfection system was also examined. The activity on biofilms formed from Stenotrophomonas maltophilia and Achromobacter sp. was evaluated. Efficacy against A. castellanii trophozoites and cysts was also investigated.Results: The PI system gave >4 log10 kill of all bacteria and fungi following the manufacturer's recommended disinfection and cleaning time of 4h, with or without the presence of organic soil. No regrowth of organisms was found after 14days in the neutralized solution. In the biofilm studies the system resulted in at least a 7 log10 reduction in viability of bacteria. For Acanthamoeba, >3 log10 kill of trophozoites and 1.1-2.8 log10 kill for the cyst stage was obtained.Conclusions: The PI system effective against a variety of pathogenic microorganisms under a range of test conditions. Strict compliance to recommended CL hygiene procedures is essential for safe CL wear. The use of care systems such as PI, with broad spectrum antimicrobial activity, may aid in the prevention of potentially sight threatening microbial keratitis. [ABSTRACT FROM AUTHOR]

An elaborated organic–inorganic hybrid method to fabricate functional textiles with excellent bacterial killing efficiencies (>99.99% against a broad spectrum of bacteria) and bacterial monitoring (differential fluorescence recovery upon contacting pathogens) is reported. Such functional textiles are extremely promising in medical and healthcare scenarios, particularly for healthcare professionals to avoid cross-contamination and post-infection caused by the continually used textiles. [Display omitted] • Excellent bactericidal efficiencies of >99.99% towards both E. coli and S. aureus. • Bacterial monitoring via differential FL recovery ability after exposure to pathogens. • Address the exclusive cross-infection concerns raised by disposable textiles. • Development of safe, comfortable, and intelligent textiles for medical healthcare. In medical, healthcare, and packaging industries, antibacterial textiles are widely used. However, contamination of textiles with bacteria can result in exclusive cross-infection. To address this issue, we devised an engineering strategy for creating organic–inorganic hybrid layers on the surface of fiber materials by combining MXene quantum dots (MQDs) with highly efficient antimicrobial agents, endowing the textiles with dual functions of bacterial killing and monitoring. Surface-functionalized MQDs were anchored on the surface of cellulose nonwovens (CNWs) by hydrogen bonding (MQDs@CNWs), followed by immobilization of Ni2+ ions by metal affinity coordination (Ni@MQDs@CNWs). In the last step, the antimicrobial compounds with catechol moieties were coordinated with Ni2+ to produce the modified textile named as NCA@Ni@MQDs@CNWs. Fluorescence (FL) recovery experiments demonstrated that NCA@Ni@MQDs@CNWs had differential FL recovery ability after exposure to pathogens with different concentrations indicating its ability for bacteria monitoring. Moreover, NCA@Ni@MQDs@CNWs exhibited excellent bactericidal efficiencies of >99.99% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in a 30-min. This work presents a novel approach for design and fabrication of biocidal textiles with ability of sensing bacteria. [ABSTRACT FROM AUTHOR]

Introduction: Nanoparticles composed of Titanium Oxide (TiO2 ) are non toxic, durable, stable and have a high refractive index with a lot of scope in biomedical applications. Due to their antibacterial effects, they can be applied to inanimate objects like glass, metal and even biomedical implants. Aim: This study was conducted to assess the antibacterial effect of Titanium Oxide (TiO2 ) alone or with Silver (Ag) as an additive on Escherichia coli. Materials and Methods: Escherichia coli isolates (n=25) sensitive to most of the drugs including first generation cephalosporins, ampicillin and amoxycillin from various samples like pus, urine, sputum and blood were placed onto the glass slides containing TiO2 annealed at 200°C, 400°C, TiO2 with 0.1% Ag as additive, TiO2 with 0.3% Ag, and TiO2 with 0.6% Ag as additive. Samples from this were inoculated at every hour onto sterile petri plates and observed for growth after overnight incubation at 37°C. Results: The organisms which were inoculated onto TiO2 annealed at 200°C showed a slower reduction rate from >1 × 108 cfu/ml to

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The research was conducted in the year 2016 at the Entomology laboratory of the Department of Crop Protection, Bayero University Kano to assess the biocidal and damage reduction effect of leaf powder from physic nut, Jatropha curcas L causedby Callosobruchus subinnotatus (Pic) on stored bambara nut, Vigna subterranea (L.) Verdcourt. Also, the study aimed at comparing the effectiveness of the plant product with conventional chemical insecticide (pirimiphos-methyl). Factorial experiment of 4x2 levels (leaf powder at the rates of 0, 0.5. 1.0 and 1.5 g, with and without addition of the synthetic chemical at 0.01 g/20 g bambara nut seed) were laid out in a Completely Randomized Design and repeated three times. Results showed that, admixture of 0.5g leaf powder proved effective in causing high biocidal effect and reduced seed damage. However, this was statistically same with seeds treated with 1.0g leafpowder. Comparatively, all treatments were statistically different from the untreated control seeds but similar with the check treatment. Highlysignificant (p<0.001) persistent effect was observedin seeds treated with 1.5g leaf powder mixed with 0.5g seed powder at 60 days after treatment (DA T) without any negative effect on seed viability. This was also statistically similar in all other treatments apart from the untreated control. In conclusion, appreciable level of protection on bambara nut seeds was achieved using leaf and seed powder of J. curcas applied at different mixture rates and singly. Therefore, it is recommended that for effective management of C subinnotatus infesting bambara nut, farmers could use 1.5 g leaf powder or 1.0 g seed powder per 20 g bambara nut seeds singly each. Alternatively, 0.5:1.0, 1.0:1.0or1.5:0.5leaf/seedcombinationscouldbe usedforsafebambara nut storage. [ABSTRACT FROM AUTHOR]

In this manuscript, we describe the fabrication of photoactive biocidal or sporicidal films from urea-derived graphitic carbon nitride (u- g -C 3 N 4 ). Co-deposited films of u- g -C 3 N 4 and Escherichia coli O157:H7 (IC 50 = 14.1 ± 0.2 mJ) or Staphylococcus aureus (methicillin resistant IC 50 = 33.5 ± 0.2 mJ, methicillin sensitive IC 50 = 42.7 ± 0.5 mJ) demonstrated significantly enhanced bactericidal behavior upon administration of visible radiation (400 nm ≤ λ ≤ 426 nm). In all cases, complete eradication of the microbial sample was realized upon administration of 100 mJ of visible radiation, while no antimicrobial activity was observed for non-irradiated samples. In contrast, Bacillus anthracis endospores were more resistant to u- g -C 3 N 4 mediated killing with only a ca . 25% reduction in spore viability when treated with a 200 mJ dose of visible radiation. Characterization of u- g -C 3 N 4 reveals that the improved activity results from enhancements of both the surface area and reduction potential of the material’s conduction band edge, coupled with fast injection of charge carriers into localized states and a decline in radiative recombination events. The results of this study demonstrate that g -C 3 N 4 -based materials offer a viable scaffold for the development of new, visible light driven technologies for controlling potentially pathogenic microorganisms. [ABSTRACT FROM AUTHOR]

A thin film combination of anti-reflection (AR) and biocidal properties would be of particular interest to reduce the transfer of infection and improve readability of public high use touch screens. In this paper we describe the development of a dual functionality film of silica (AR) and copper oxide (biocidal). Deposition was via flame assisted chemical vapour deposition (FACVD) which has the advantages of being a cost efficient atmospheric pressure technique enabling use of non-volatile precursors and that no closed reaction cell is required so making it ideal for integration into industrial production lines. The resulting films were characterised by a range of techniques including optical spectroscopy, electron microscope and X-ray fluorescence. Biocidal behaviour was tested by determining the kill rate of Escherichia coli . A 3 layer stack on glass of silica/copper oxide/silica had better adhesion and lower reflection than a comparable 2 layer stack. This multilayer film led to a > 2% drop in reflection from that of uncoated glass, similar to that of silica only film. In addition, showed a > 6 log10 kill between 6 and 24 h for as deposited and annealed samples. [ABSTRACT FROM AUTHOR]

In situsynthesis of size- and shape-controlled silver nanoparticles (AgNPs) on fabrics was evaluated with structural and morphological characterization (scanning electron microscope, X-ray diffraction, and energy-dispersive spectroscope (EDS)). At lower concentration of NaBH4(0.5 mM) with preferred AgNO3(1 mM) mixtures shows uniform distribution of AgNPs on cotton fabrics. The attachment of smaller sized and discrete AgNPs on fabrics shows good antibacterial action on comparison with other aggregated and larger sized AgNPs when tested inShigella sonneiandBacillus subtilisspecies. Higher bactericidal action and relative change in hydrophobic nature (water contact angle >110°) of treated fabrics explained by decrease in surface free energy could have self-cleaning biomedical applications. [ABSTRACT FROM PUBLISHER]

We report the development of copolymers based on 2-vinylpyridine with different porosity degrees. The copolymers were quaternized with methyl iodide and acrylonitrile to introduce quaternary ammonium groups on pyridine units. To prepare charge transfer complexes, the unmodified copolymers and their derivatives quaternized were impregnated with iodine. The antibacterial properties of all the polymers were evaluated ranging from of the Escherichia coli strain. The unmodified copolymers did not have antibacterial activity against E.Coli suspensions. The quaternization with methyl iodine and acrylonitrile increased the biocidal performance of these copolymers, but only the copolymer with the lowest porosity modified with methyl iodine showed significant bactericidal action for all E. Coli concentrations. The 2-vinylpiridine copolymers quaternized and impregnated with iodine had higher antibacterial activity than the impregnated ones. The charge transfer complexes derived from the copolymer with the lowest porosity and highest swelling capacity in water had the best bactericidal performance.

The SARS-CoV-2 global pandemic has reinvigorated interest in the creation and widespread deployment of durable, cost-effective, and environmentally benign antipathogenic coatings for high-touch public surfaces. While the contact-kill capability and mechanism of metallic copper and its alloys are well established, the biocidal activity of the refractory oxide forms remains poorly understood. In this study, commercial cuprous oxide (Cu 2 O, cuprite) powder was rapidly nanostructured using high-energy cryomechanical processing. Coatings made from these processed powders demonstrated a passive "contact-kill" response to Escherichia coli ( E. coli ) bacteria that was 4× (400%) faster than coatings made from unprocessed powder. No viable bacteria (>99.999% (5-log10) reduction) were detected in bioassays performed after two hours of exposure of E. coli to coatings of processed cuprous oxide, while a greater than 99% bacterial reduction was achieved within 30 min of exposure. Further, these coatings were hydrophobic and no external energy input was required to activate their contact-kill capability. The upregulated antibacterial response of the processed powders is positively correlated with extensive induced crystallographic disorder and microstrain in the Cu 2 O lattice accompanied by color changes that are consistent with an increased semiconducting bandgap energy. It is deduced that cryomilling creates well-crystallized nanoscale regions enmeshed within the highly lattice-defective particle matrix. Increasing the relative proportion of lattice-defective cuprous oxide exposed to the environment at the coating surface is anticipated to further enhance the antipathogenic capability of this abundant, inexpensive, robust, and easily handled material for wider application in contact-kill surfaces.

Objective: In this study, it was aimed to determine qualitatively the substances in the composition of biocidal products and plant protection sold in public areas with reference to current use of prohibited pesticides detected in toxicological studies conducted in Antalya province. Methods: A total of 19 samples sold under the name of DDT, insecticide, termiticide were gathered from public markets, illegal suppliers and districts where agricultural activities take place in Antalya province. To identify ingredients of products, after 100 mg of each was weighed and dissolved in 10 ml methanol, it was diluted with isooctane, and tested to instrumental analysis on a Gas Chromatography-Mass Spectrometry (Shimadzu QP2010 Ultra). Chromatograms gathered from scan mode were matched with the content of Wiley/NIST which has a comprehensive pesticide library. Results: AAs a result of qualitative evaluation, it was observed that dichlorvos, aldicarb and cypermethrin as well as Dursban whose active ingredient is chlorpyrifosethyl in the samples. In addition to these active ingredients, inactive ingredients (extender) such as sebacic acid, mercaptane, propionic acid were detected at varying ratios in the samples. While chlorpyrifos-ethyl was mostly detected in 31.6% of the active content available, sebacic acid (47.4%) was mostly detected as extender ingredient as well. Conclusion: It has been observed that there are materials that are classified as carcinogenic by USEPA and may pose a threat to human health in the content of some of the products analyzed, or that the products which do not contain any active ingredient affecting incect pests have been used in commercial activities away from control and supervision. It is considered that the unconscious implementation of such products by persons with insufficient knowledge may constitute a serious risk in terms of both user and environment. [ABSTRACT FROM AUTHOR]

Schiff bases are versatile ligands and play important role in medicinal and bioinorganic fields because of their wide spectrum of biological activities. Schiff bases are multipurpose ligands which are amalgamated from the condensation of carbonyl compounds with an amino compound. Schiff bases and their metal complexes are also used for industrial purposes and their metal complexes have been screened for their in vitro biological activities against bacteria, fungi and yeast. These complexes also show significant growth inhibitory activity against the bacteria like Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Klebsilla Pneumonia, etc. than the free ligands. Most of them show biological activities such as antibacterial, antifungal antioxidant, biocidal, antiviral as well as antitumor activity. It has been observed that the antimicrobial activities of these metal complexes are higher than that of the free ligand. [ABSTRACT FROM AUTHOR]

[Display omitted] • A review of development of antibiofilm materials with great potential for adaptation in food applications. • Antibiofilm strategies including "attack", "defense", and a combination of both are provided. • The working mechanisms of "attack" agents and "defense" agents are highlighted. • Trends in developing novel antibiofilm strategies via a combination of "attack" and "defense" functions. Foodborne diseases caused by ingesting pathogen-contaminated foods have become a significant global challenge afflicting public health. A report from the National Institute of Health found that around 80% of microbial infections were related to the generation of microbial biofilms on food-contact surfaces. Therefore, developing a universally applicable food-contact surface with an effective antibiofilm function is urgently needed. However, many antibiofilm strategies are designed for marine and medical industries, which are not fully applicable to the food area. Therefore, in this review, a comprehensive overview of the reported antibiofilm strategies originally designed for various applications is presented. According to their working mechanisms, these antibiofilm strategies were divided into "attack", "defense", and a combination of both. In addition, definitions, antibiofilm mechanisms, features, inherent limitations, and suitable application scenarios of typical antibiofilm strategies were systematically summarized, respectively, which could provide some underlying principles and perspectives to design food-contact surfaces with desirable antibiofilm functions in the future. [ABSTRACT FROM AUTHOR]

Two N-halamine precursors, 1-glycidyl-s-triazine-2,4,6-trione and 1-(2,3-dihydroxypropyl)-s-triazine-2,4,6-trione, were synthesized and tethered onto cotton fabrics via the crosslinking agent 1,2,3,4-butanetetracarboxylic acid. The modified samples were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). The modified fabrics were rendered biocidal activities upon exposure to dilute hypochlorite solutions. The chlorinated cotton swatches were challenged with Staphylococcus aureus (ATCC 6538) and Escherichia coli O157:H7 (ATCC 43895) and exhibited excellent biocidal efficacy. The stability and rechargeability of the modified samples during washing and ultraviolet irradiation were also investigated. In vitro cell cytocompatibility studies demonstrated that the antibacterial cotton has good biocompatibility. [ABSTRACT FROM AUTHOR]