Formation of biofilms allows bacterial cells to survive in adverse environments. Nontuberculous mycobacteria are ubiquitous in aqueous environments, where they adhere to surfaces and create a ...biofilm. This has led to the emergence of healthcare-associated infections and the use of biomaterials in medicine. Essential oils (EO) are substances of natural origin whose effect on microorganisms has been the subject of numerous studies. Here, we investigated the effect of Juniperus communis EO on nontuberculous mycobacteria and their early and mature biofilm formation in sterilised tap water. The combination of Juniperus communis EO and increasing ambient temperature showed a synergistic effect on the reduction of biofilm formation of Mycobacterium avium and Mycobacterium intracellulare on a polystyrene surface. A significant antibiofilm effect of Juniperus communis EO was also found at subinhibitory concentrations, suggesting a potential role for it as an alternative disinfectant of natural water.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
The paper examines the antiproliferative, antimicrobial and antioxidative effects of fir (Abies alba Mill.) honeydew honey from mountain region of Croatia (Gorski kotar) as a potential replacement ...for standard antibiotics and chemotherapeutic agents. Cell viability, annexin V assay and flow cytometry analysis served to analyse the antiproliferative effect on, apoptosis induction in and cell death of cancer cell lines: HeLa, MCF-7, SW620, CFPAC-1, MIA PaCa-2 and normal diploid human fibroblasts (BJ). Antimicrobial activity was tested against Staphylococcus and Acinetobacter strains by agar well diffusion and microdilution assays. The DPPH.sup.* assay determined the radical scavenging activity, while mathematical models helped to evaluate the kinetic data of DPPH.sup.* inhibition. Antiproliferative effect on all tested cell lines and the prominent effect on normal diploid human fibroblasts (BJ), colorectal adenocarcinoma (SW620, metastatic) and breast epithelial adenocarcinoma (MCF-7, metastatic) was observable. The mechanisms of antiproliferative effect included accumulation of cells in the sub-G1 phase in all tested cells and induction of apoptosis in SW620 and MCF-7 cells predominantly. The antibacterial assays showed that antibiotic-resistant strains of both bacteria, including multi-resistant strain A. baumannii ATCCR BAA1605TM, were sensitive to all tested honey samples. Radical scavenging assay suggests that antioxidants present in the honey possess different radical suppressing abilities and that they react at different rates with radicals, thereby causing two steps of reaction. The results of the study indicate that Croatian fir honeydew honey has a therapeutic potential due to the strong biological activity and can serve to protect human health.Key words: fir (Abies alba Mill.) honeydew honey, cell cycle, apoptosis, antimicrobial activity, antioxidant capacity, kinetic analysis
Pool water must meet certain chemical and microbiological conditions to ensure high water quality and a safe environment for users. A recreational swimming pool treated with a combined disinfection ...method (chlorination and UV radiation) was monitored for 18 months. Selected chemical and microbiological parameters of the indoor freshwater pool were analyzed, and the in vivo presence of Pseudomonas aeruginosa biofilm was assessed and further correlated to the type of disinfection. P. aeruginosa isolated from biofilm was further examined to determine the effects of combined disinfection methods on the formation and destruction of mature biofilm in vitro. The in vitro application of the combined disinfection methods led to the inhibition of planktonic P. aeruginosa biofilm formation (68.9% compared to the control group) and were more effective in the partial destruction of mature biofilm than individual disinfection methods (from 25.4 to 26.3%). The obtained results indicate the better microbiological and chemical quality of pool water when combined disinfection was applied. Our results contribute to developing the optimization of pool water disinfection methods and biofilm control.
Pseudomonas fluorescens is one of the first colonizers of bacterial biofilm in water systems and a member of opportunistic premise plumbing pathogens (OPPPs). The aim of this study was to examine the ...effect of UV light and sodium hypochlorite on the formation and destruction of mature P. fluorescens biofilm on ceramic tiles. Planktonic bacteria or bacteria in mature biofilm were exposed to UV light (254 nm) for 5, 20 s. and to 0.4 mg/L sodium hypochlorite for 1 min. Mature biofilm was also exposed to increased concentration of sodium hypochlorite of 2 mg/L for 0.5, 1 and 2 h and combined with UV. Prolonged action of sodium hypochlorite and an increase in its concentration in combination with UV gave the best results in the inhibition of biofilm formation after the pre-treatment and destruction of mature biofilm. The effect of hyperchlorination in combination with UV radiation shows better results after a long exposure time, although even after 120 min there was no completely destroyed biofilm. Furthermore, the mechanism of the effect of combined methods should be explored as well as the importance of mechanical cleaning that is crucial in combating bacterial biofilm in swimming pools.
Honey is a natural food consisting mainly of sugars, enzymes, amino acids, organic acids, vitamins, minerals and aromatic substances. In addition to specific organoleptic properties, honey also has ...other components that contribute to its nutritional and health value. Proteins, vitamins, minerals, organic acids and phenolic compounds, the most variable components of honey, are predominantly responsible for its strong bioactive effect. Honeydew honey is a less known type of honey with outstanding antimicrobial and antioxidant properties that also demonstrates prebiotic effects and can promote the growth of probiotic bacteria. Foodborne illnesses can be prevented by using probiotic strains in combination with prebiotics. The aim of this study was for the first time to determine potential synergistic antimicrobial effect of fir (Abies alba Mill.) honeydew honey (HS) and probiotic bacteria Lactiplantibacillus plantarum on Salmonella enterica serotype Typhimurium, a primary cause of foodborne illnesses. The effect of three different samples of fir honeydew honey on the growth of L. plantarum in de Man, Rogosa and Sharpe (MRS) medium and the potential synergistic effect of HSs and L. plantarum on the growth of S. Typhimurium in the Brain Heart Infusion (BHI) medium were examined. The results indicate that concentrations of 1 and 5% of all three HS samples stimulate the growth and metabolic activity of L. plantarum, while a concentration of 10% inhibits the growth of L. plantarum. The concentration of 5% of all three HS and L. plantarum combined inhibits the growth of S. Typhimurium in BHI broth. Fir honeydew honey showed potential prebiotic properties and antimicrobial activity, both of which can synergistically enhance the probiotic efficacy of L. plantarum against S. Typhimurium To conclude, the combination of fir honeydew honey and L. plantarum represents a successful combination against S. Typhimurium and additional experiments are necessary regarding the mechanisms of their combined effect.
Pseudomonas fluorescens is one of the first colonizers of bacterial biofilm in water systems and a member of opportunistic premise plumbing pathogens (OPPPs). The aim of this study was to examine the ...effect of UV light and sodium hypochlorite on the formation and destruction of mature P. fluorescens biofilm on ceramic tiles. Planktonic bacteria or bacteria in mature biofilm were exposed to UV light (254 nm) for 5, 20 s. and to 0.4 mg/L sodium hypochlorite for 1 min. Mature biofilm was also exposed to increased concentration of sodium hypochlorite of 2 mg/L for 0.5, 1 and 2 h and combined with UV. Prolonged action of sodium hypochlorite and an increase in its concentration in combination with UV gave the best results in the inhibition of biofilm formation after the pre-treatment and destruction of mature biofilm. The effect of hyperchlorination in combination with UV radiation shows better results after a long exposure time, although even after 120 min there was no completely destroyed biofilm. Furthermore, the mechanism of the effect of combined methods should be explored as well as the importance of mechanical cleaning that is crucial in combating bacterial biofilm in swimming pools.
Acinetobacter baumannii is a prominent emerging pathogen responsible for a variety of hospital-acquired infections. It can contaminate inanimate surfaces and survive in harsh environmental conditions ...for prolonged periods of time in the form of biofilm. Biofilm is difficult to remove with only one method of disinfection, so combined disinfection methods and biocidal active substances are needed for biofilm eradication. Additionally, having in mind ecological demands, legislators are more prone using fewer toxic substances for disinfection that produce less solid waste and hazardous disinfection byproducts. Gaseous ozone and citric acid are natural biocidal compounds, and the purpose of this study was to determine their combined biocidal effects on A. baumannii biofilm formed on ceramics and polystyrene. Twenty-four-hour A. baumannii biofilm formed on ceramic tiles and polystyrene was exposed to different combinations of disinfection protocols with 25 ppm of gaseous ozone for 1 h exposure time and 15% citric acid for 10 min exposure. The total number of bacteria was counted afterwards and expressed as CFU/cmsup.2. The determined disinfection protocols of A. baumannii biofilm with combined citric acid and gaseous ozone caused reduction of 2.8 to 5.89 logsub.10 CFU (99.99% inhibition rate) of total viable bacteria for each method, with the citric acid-ozone-citric acid disinfection protocol being most successful in eradication of viable bacteria on both ceramics and polystyrene. In conclusion, gaseous ozone and citric acid showed good combined biocidal effects on A. baumannii biofilm and successfully reduced early A. baumannii biofilm from ceramic and polystyrene surfaces. The given combination of active substances can be a good option for eco-friendly disinfection of hospital inanimate surfaces from A. baumannii biofilm contamination with prior mechanical cleaning.
Acinetobacter baumannii is a prominent emerging pathogen responsible for a variety of hospital-acquired infections. It can contaminate inanimate surfaces and survive in harsh environmental conditions ...for prolonged periods of time in the form of biofilm. Biofilm is difficult to remove with only one method of disinfection, so combined disinfection methods and biocidal active substances are needed for biofilm eradication. Additionally, having in mind ecological demands, legislators are more prone using fewer toxic substances for disinfection that produce less solid waste and hazardous disinfection byproducts. Gaseous ozone and citric acid are natural biocidal compounds, and the purpose of this study was to determine their combined biocidal effects on A. baumannii biofilm formed on ceramics and polystyrene. Twenty-four-hour A. baumannii biofilm formed on ceramic tiles and polystyrene was exposed to different combinations of disinfection protocols with 25 ppm of gaseous ozone for 1 h exposure time and 15% citric acid for 10 min exposure. The total number of bacteria was counted afterwards and expressed as CFU/cm2. The determined disinfection protocols of A. baumannii biofilm with combined citric acid and gaseous ozone caused reduction of 2.8 to 5.89 log10 CFU (99.99% inhibition rate) of total viable bacteria for each method, with the citric acid–ozone–citric acid disinfection protocol being most successful in eradication of viable bacteria on both ceramics and polystyrene. In conclusion, gaseous ozone and citric acid showed good combined biocidal effects on A. baumannii biofilm and successfully reduced early A. baumannii biofilm from ceramic and polystyrene surfaces. The given combination of active substances can be a good option for eco-friendly disinfection of hospital inanimate surfaces from A. baumannii biofilm contamination with prior mechanical cleaning.
Summary
Adhesion of foodborne pathogens to materials of industrial surfaces is an important step in their transmission through the food chain. Adhesion is also a prerequisite for bacterial ...colonisation within a host, to enable intracellular invasion. We define a strategy to reduce contamination and infection by Listeria monocytogenes, Campylobacter jejuni and Escherichia coli using an ethanol extract of Alpinia katsumadai seeds (AlpE) and epigallocatechin gallate (EGCG) as anti‐adhesive agents. We show for the first time that AlpE and EGCG reduce adhesion of individual cultures to polystyrene (AlpE, up to 10.6%; EGCG, up to 39.7%) and to the amoeba Acanthamoeba castellanii (AlpE, up to 52.6%; EGCG, up to 53.4%). The combination of AlpE/EGCG significantly reduced C. jejuni adherence to the abiotic (45.5%) and biotic (52.2%) surfaces. Thus, using natural agents from plants at low doses, we can potentially reduce the primary source of food contamination and a frequent source of infections.
The anti‐adhesion effects of Alpinia katsumadai seeds (AlpE) and epigallocatechin gallate (EGCG) were determined for foodborne bacterial attachment to polystyrene as an abiotic surface and A. castellanii as a biotic surface.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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