Search Results (213)

Logs supplied in Papua New Guinea and Indonesia are predominantly sourced from fast-growing tree species of plantation forests. The timber primarily consists of sapwood, which is highly susceptible to biodeterioration. At a training center, CCA (chromated copper arsenate) is still used for wood preservation, while in the wood industry, ACQ (alkaline copper quaternary) is commonly applied to enhance the service life of timber. In the future, polystyrene impregnation or other non-biocidal treatments could potentially serve this purpose. This study aimed to determine the discoloration and resistance of polystyrene-impregnated and CCA-preserved woods. Wood samples, Anisoptera thurifera and Octomeles sumatrana from Papua New Guinea, and Anthocephalus cadamba and Falcataria moluccana from Indonesia, were used. The wood samples were treated with polystyrene impregnation, CCA preservation, or left untreated, then exposed at the PNG Forest Research Institute site for four months. After treatment, the color change in polystyrene-impregnated wood was minor, whereas CCA-preserved wood exhibited a noticeably different color compared to untreated wood. The average polymer loading for polystyrene-impregnated wood reached 147%, while the average CCA retention was 8.4 kg/m³. Densities of untreated-, polystyrene-, and CCA-wood were 0.42, 0.64, and 0.45 g/cm³, respectively, and moisture contents were 15.8%, 9.4%, and 13.4%, respectively. CCA preservation proved highly effective in preventing termite attacks; however, CCA is hazardous to living organisms, including humans. Polystyrene impregnation also significantly improved wood resistance to subterranean termites, as indicated by lower weight loss and a higher protection level compared to untreated wood. Additionally, polystyrene treatment is nonhazardous and safe for living organisms, making it a promising option for enhancing wood resistance to termite attacks in the future as an alternative to the biocides currently in use. Full article

Background: The qacE gene and its variant, qacE∆1, have been associated with resistance to antimicrobials and biocides. This poses a threat to infection prevention, control and treatment. Several studies investigated this relationship with conflicting results. The aim of this research was to determine the prevalence of qacE and qacE∆1 in clinical extended spectrum β-lactamase- (ESBL) and carbapenemase-producing Klebsiella spp. and Enterobacter spp. and elucidate the association of these genes with resistance to sodium hypochlorite. Methods: This study included 216 isolates of ESBL- and carbapenemase-producing multidrug-resistant (MDR) Klebsiella spp. and Enterobacter spp. These isolates were identified by VITEK-2 analyser. The MIC and MBC of sodium hypochlorite were determined using the microbroth serial-dilution method. PCR was used to detect gene variants. A regression analysis investigated any association between qacE genotypes, MIC and MBC, as well as antimicrobial drug resistance profiles. Results: Overall, there was a high prevalence of qacE and qacE∆1 variants (84.7%; 95% CI, 79.2–89.2). There was a high prevalence of qacE∆1 (80.6%; 95% CI, 74.6–85.6) as compared to qacE (15.3%, 95% CI, 10.8–20.8). The MIC₅₀ and MIC₉₀ of the isolates ranged between 7031 mg/L and 9375 mg/L and 14,060 mg/L and 18,750 mg/L, respectively, while the MBC ranged from 48,750 mg/L to 18,750 mg/L. There was no association between qacE genotypes and high MIC and MBC as well as antimicrobial drug resistance. Conclusions: The MIC and MBC of sodium hypochlorite are higher than what is currently used for disinfection in Botswana. There is a high prevalence of qacE and qacE∆1; however, these genes do not seem to be associated with resistance to sodium hypochlorite. Full article

Mastitis is a common condition in dairy cattle that causes huge losses globally. The inflammation is caused by the invasion of the teat canal by pathogens, including hard-to-control single-cell microalgae of the genus Prototheca. The aim of the study was the in vitro comparison of the antimicrobial properties of 10 selected essential oils (EOs) and amphotericin B (AMB) against Prototheca bovis strains (PRO3 and PRO7) from different regions in Poland. The antialgal effect was estimated by using toxicity tests. The chemical composition of the EOs was determined by using gas chromatography coupled with mass spectrometry. The tested EOs had significant cytotoxic effects on algal viability. A statistical analysis of the results revealed that the highest biocidal potential, at a concentration of 2%, was demonstrated by lavender, rosemary, and oregano oils, reducing the survival of the Prototheca bovis strains, on average, by 51.21%, 45.83%, and 45.15%, respectively. In comparison, AMB reduced algal viability by an average of 88% compared with the control groups. Further research into the utilization of the biocidal properties of lavender, rosemary, and oregano oil against Prototheca spp. may help to develop new forms of treatments against mastitis caused by this pathogen in the future. Full article

This study introduces a pilot protocol for evaluating the environmental impact of materials used in the conservation of canvas paintings, applying a Life Cycle Impact Assessment (LCIA) approach. There are five common treatment phases: disinfection, consolidation (including paint layer softening and stabilization), varnish removal, and retouching. These interventions were assessed across three scenarios: Baseline Scenario; Scenario 1, involving material substitution; and Scenario 2, focusing on process optimization. The analysis reveals that solvent-intensive phases, particularly paint softening with Methyl Ethyl Ketone (MEK) and varnish removal using White Spirit and ethanol, have the highest environmental impacts, including climate change, ecotoxicity, and human toxicity. Biocidal treatments, although used in small quantities, also show significant toxicity impacts. Scenario 1 demonstrates that targeted substitution with lower-impact solvents can reduce key impact categories, while Scenario 2 indicates that operational improvements lead to more moderate but widespread benefits. The results confirm that even in specialized fields such as cultural heritage conservation, measurable environmental improvements are achievable through informed material choices and more efficient application practices. Full article

Biofouling, the undesirable deposition of microorganisms on surfaces, is ubiquitous in aqueous systems. This is no different for systems running with water-miscible metalworking fluids (MWFs), which additionally contain many organic chemicals that create favorable conditions for growth and metabolism. Biofilm formation is thus inevitable, as there is no shortage of wetted surfaces in metalworking systems. MWF manufacturers tried in vain to offer resistance by using biocides and biostatic compounds as ingredients in concentrates and as tank-side additives. We report here that such elements, alone or as components of MWFs, did not prevent biofilm formation and had negligible effects on pre-established laboratory biofilms. Moreover, biofilms in metalworking systems are interwoven with residues, sediments, and metal swarfs generated during machining. Again, co-incubation of such “real” biofilms with MWFs had no significant effect on population size—but on population composition! The implications of this finding are unclear but could provide a starting point for the treatment of biofouling, as biofilm population structure might be of importance. Finally, we show that bacteria gain function in biofilms and that they were able to degrade a toxic amine in MWFs, which the same bacteria were unable to do in planktonic form. Full article

In this study, a historically significant journal subject to fungal colonization was used as a case study for experimenting with a fumigation treatment using essential oils. The experiments were carried out both in vitro and in vivo directly on the artifact. Post-treatment monitoring showed that the succession of two fumigation treatments (alternately using rosemary and lavender oil) resulted in the complete disinfection of the first and second populations detected on the substrate. The latter was identified as Trichoderma longibrachiatum, a human pathogenic species, which was found to be sensitive to various concentrations of rosemary essential oil (1.2% v/v) and lavender essential oil (0.4% v/v), while it was not contained by the standard biocide based on benzalkonium chloride. The results obtained allowed the proposal of an application protocol for the fumigation of paper items that need to undergo biocidal treatment, which consists of alternating essential oils to increase the action spectrum of the natural substances and implementing a rotation principle to prevent the development of bio-resistances. Full article

Biodeterioration poses a significant challenge in the conservation of cultural heritage, particularly for earthen sites in humid environments, which are highly susceptible due to their inherent material properties. To address the diverse biological threats affecting such sites, we developed a novel broad-spectrum biocide, FACA, formulated by combining phenylcarbamoylthiazoles and isothiaquinolones to achieve triple efficacy: antimicrobial, anti-algal, and anti-lichen effects. Laboratory assessments demonstrated FACA’s rapid efficacy in eliminating molds, algae, and lichens. A 12-month field application at the Sanyangzhuang earthen site (Neihuang, Henan) yielded excellent results, confirming long-term protection against biological colonization without recurrence. Crucially, the treatment exhibited no adverse effects on the earthen sites, enabling sustainable coexistence between the heritage site and its surrounding ecosystem. These findings support the applicability of FACA for surface treatment across various humid earthen archeological sites. Full article

Silver nanoparticles (AgNPs) have emerged as a promising antimicrobial agent in dentistry due to their distinctive physicochemical characteristics and broad-spectrum biocidal activity. For example, silver nanoparticles can be incorporated into oral hygiene products in preventive dentistry, composite resins in restorative treatment, irrigation solutions in endodontic treatment, membranes for guided tissue regeneration in periodontal treatment, acrylic resins and porcelains in prosthodontic treatment, coatings in dental implant treatment, and brackets and wires in orthodontic treatment. This paper focuses on summarizing the current knowledge on the antimicrobial use of silver nanoparticles in dentistry, highlighting their antimicrobial mechanism and potential applications in clinical treatment. The literature indicates that silver nanoparticles are a promising antimicrobial agent in dentistry. However, there are still many issues including fundamental antibacterial mechanisms that need to be completely elucidated before clinical applications. Full article

Bacterial infections are the primary cause of mastitis in dairy cattle. Fungal mastitis occurs in 1–12% of cases. Antibiotic therapy, the standard treatment for mastitis, has led to antibiotic-resistant bacteria, reducing treatment efficacy and increasing fungal mastitis occurrence. Antibiotics lack biocidal effects on fungi, which often exhibit resistance to antifungal agents. This study evaluated the antifungal properties of nanoparticles (NPs) against Candida albicans, Candida glabrata, Candida parapsilosis, Diutina rugosa var. rugosa, Diutina catenulata, and Diutina rugosa. Tested NPs included gold (AuNPs), silver (AgNPs), copper (CuNPs), iron with hydrophilic carbon coating (FeCNPs) (1.56–25 mg/L), and platinum (PtNPs) (0.625–10 mg/L), along with their complexes. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) at 0.75–25 mg/L for AuNPs, AgNPs, CuNPs, and FeCNPs and 0.313–10 mg/L for PtNPs, as well as fungal sensitivity to standard antifungals, were determined. Each strain showed different sensitivities depending on the NPs used and their concentrations. C. glabrata was the most resistant to nanoparticles, while D. catenulata was the most susceptible. PtNPs and FeCNPs showed no or weak biocidal properties. Some mycotic-resistant strains were sensitive to nanoparticles. This study indicates a high in vitro antifungal potential for the application of nanoparticles, especially AgCuNPs, as a new effective non-antibiotic agent for the prevention and control of mycotic mastitis in dairy cattle. Full article

The vase life of cut hydrangea (Hydrangea macrophylla) flowers is a critical quality parameter, influencing their marketability and consumer satisfaction. This review examines the influence of various treatments on prolonging the postharvest lifespan of cut hydrangea blooms. It discusses hydrangea in general and its after-harvest mechanism, the vase life of cut hydrangea inflorescence in two phases, and conditions such as different storage temperatures and storage terms and length. It also highlights postharvest factors affecting cut flowers longevity like interventions targeting water balance, carbohydrate degradation, and sensitiveness to ethylene. Specific treatments that positively extend the life span of cut hydrangeas, such as sucrose, biocides, essential oil compounds, and commercial preservative solutions, are also evaluated. These treatments successfully increased the vase life of cut flowers from 3.6 to 12.3 days. The most effective solution for significantly extending the vase life of cut hydrangea flowers (‘Magical Jewel’) by 12.3 days was the combination of 1% sucrose and 8-HQS (8-hydroxyquinoline sulphate). The focus is on hydrangeas’ physiological and biochemical responses to these treatments, particularly their effects on water absorption, microbial activity, and the senescence process. By synthesising recent advancements and identifying research gaps, this review aims to provide actionable steps for growers, florists, and researchers to optimise the vase life of cut hydrangeas and improve the sustainability of their postharvest handling. Full article

The prevention of human infectious diseases associated with waterborne pathogens is reliant on the effective disinfection of water supplies by drinking water treatment plants and adequately maintained distribution networks. For decades, the chlorination of water has safeguarded public health, where chlorine is broadly applied in both water disinfection and food production facilities, including the dairy industry, from farm to fork. The identification of chlorine disinfection byproducts in water supplies and dairy food produce is of great concern, however, due to their cytotoxic, genotoxic, mutagenic, teratogenic, and potential endocrine-disrupting activity. The association between the trihalomethanes (THMs) and haloacetic acids (HAAs) and tumour formation is documented and has led to the implementation of maximum contaminant levels enforced by the European Union. Furthermore, chlorine resistance in bacterial species is associated with multidrug resistance in clinically relevant pathogens, where antibiotic- and biocidal-resistant genes are also environmental pollutants. Increasing the concentration of chlorine to surmount this resistance will ultimately lead to increasing concentrations of byproducts in both water and food products, exceeding the EU requirements. This article provides insight into chlorine DBPs as a toxicological public health risk and the relationship between chlorine resistance and antibiotic resistance in microbes relevant to dairy food production. Full article

This paper addresses the upconversion of blue light to ultraviolet-C (UVC) with Pr³⁺-activated materials for antibacterial applications of UVC. It discusses the processes through which UV radiation provides biocidal effects on microorganisms, along with the most popular UVC sources employed in these processes. We describe the electronic and optical properties of the Pr³⁺ ion, emphasizing the conditions the host material must meet to obtain broad and intense emission in the UVC from parity-allowed transitions from the 4f5d levels and provide a list of materials that fulfill these conditions. This paper also delineates lanthanide-based upconversion, focusing on Pr³⁺ blue to UVC upconversion via the ³P₀ and ¹D₂ intermediate states, and suggests routes for improving the quantum efficiency of the process. We review literature related to the use of upconversion materials in antimicrobial photodynamic treatments and for the blue to UVC upconversion germicidal effects. Further, we propose the spectral overlap between the UVC emission of Pr³⁺ materials and the germicidal effectiveness curve as a criterion for assessing the potential of these materials in antimicrobial applications. Finally, this paper briefly assesses the toxicity of materials commonly used in the preparation of upconversion materials. Full article

Bacteriophages can be used as biocontrol agents in agriculture to improve food safety, provided they can remain viable in food environments. The viability of ten Shigella phages (AShi, Shi3, Shi22, Shi30, Shi33, Shi34, Shi40, Shi88, Shi93, and Shi113) was evaluated against different additives and biocides used daily in food applications. In addition, the influence of additives on phage viability in a food matrix was investigated. Treatments with lactic and citric acid were the most effective to inactivate phages. In addition, the acetic acid was the most phage-friendly treatment evaluated. Preservatives such as acetate, lactate, benzoate, sorbate, and propionate proved to be highly compatible with all the phages tested. Regarding the influence of the food matrix on phage viability, an equal or higher viability was found for most phages tested when compared with the corresponding organic acid. Finally, when phages were exposed to sodium hypochlorite, ethanol, quaternary ammonium chloride (QAC), and H₂O₂, most of them were sensitive to long incubations and high concentrations. However, when biocide concentrations employed are low, 10³–10⁴ PFU mL⁻¹ phage particles remains viable. Thus, the phages evaluated could be used in combination with additives and biocides as a biocontrol tool against the foodborne pathogen S. flexneri in agricultural products. Full article

The presence of opportunistic pathogens, such as the Enterobacter cloacae complex (ECC), in fresh vegetables poses a significant health risk, particularly amid the ongoing antibiotic resistance crisis. Traditional chemical decontamination methods are often ineffective and these are associated with issues such as cross-resistance between antibiotics and biocides, highlighting the need for alternative approaches. This study describes the isolation of a novel phage, FENT2, with anti-ECC activity, obtained from cattle farm sewage. Belonging to the Seunavirus genus, FENT2 did not carry genes associated with lysogenic cycle, antimicrobial resistance, or virulence factors. The phage demonstrated lytic activity against the host strain E. kobei AG07E, which harbored the mcr-9 gene, exhibiting a narrow host range that also included E. ludwigii strains. In vitro assays using BioTrac (SY-LAB) impedance technology confirmed the sustained lytic activity of FENT2 under food-related stress conditions, including pH levels from 5 to 7 and NaCl concentrations up to 2%. Furthermore, FENT2 demonstrated bactericidal potential on lettuce leaves, achieving 1 log reduction in bacterial counts of the host strain after 30 min immersion treatment. These findings highlight FENT2 as a promising candidate for biocontrol applications, offering a sustainable alternative to conventional decontamination methods for reducing antimicrobial-resistant ECC contamination in fresh produce. Full article

Hydrocarbon fuel biofouling and biocorrosion require expensive cleanup of aviation infrastructures unless appropriate sustainment measures are applied. The identification of novel biological control agents offers promising alternatives to the current chemical biocides used in fuel sustainment. In this study, 496 microbial fuel isolates from our in-house repository were screened to identify new endogenously produced antimicrobial compounds. Using agar plug screening, liquid culture growth testing, and Jet A fuel culture assays, the two fuel-isolate strains Pseudomonas protegens #133, and Bacillus subtilis #232 demonstrated promising biocontrol activity against bacteria, yeast, and filamentous fungi. Liquid chromatography-quadrupole time of flight tandem mass spectrometry (LC-QTOF-MS/MS) of #232 culture filtrate identified several common lipopeptide antimicrobials including gageostatin C, gageopeptin B, and miscellaneous macrolactins. In contrast, LC-QTOF-MS/MS identified the siderophore pyochelin as one of the predominant compounds in #133 culture filtrate with previously demonstrated antimicrobial effect. Jet fuel microbial consortium culture testing of #133 culture filtrate including flow-cytometry live/dead cell mechanism determination demonstrated antimicrobial action against Gram-positive bacteria. The study concludes that antimicrobial compounds secreted by #133 have bactericidal effects against Gordonia sp. and cause cell death through bacterial lysis and membrane damage with potential applications in the biocidal treatment of hydrocarbon-based aviation fuels. Full article