High resistance to environmental factors as well as the ability to form biofilms allow Listeria monocytogenes to persist for a long time in difficult-to-reach places in food-producing plants. L. monocytogenes enters final products from contaminated surfaces in different areas of plants and poses a health risk to consumer. Modified surfaces are already used in the food industry to prevent cross-contamination. In this study, stainless-steel surfaces were coated with nanoscale silicon dioxide and the effects on attachment, bacterial growth and detachment of L. monocytogenes were evaluated. Attachment was considered for three different ways of application to simulate different scenarios of contamination. Bacterial growth of L. monocytogenes on the surface was recorded over a period of up to 8 h. Detachment was tested after cleaning inoculated stainless-steel surfaces with heated distilled water or detergent. Coating stainless-steel surfaces with nanoscale silica tends to reduce adherence and increased detachment and does not influence the bacterial growth of L. monocytogenes. Further modifications of the coating are necessary for a targeted use in the reduction of L. monocytogenes in food-processing plants.
Biocompatibility is one of the key issues for implants, especially in the case of stainless steel with medium to low biocompatibility, which may lead to a lack of osseointegration and consequently to implant failure or rejection. To precisely control preferential cell growth sites and, consequently, the biocompatibility of prosthetic devices, two types of surfaces were analyzed, containing periodic nanogrooves laser induced periodic surface structure (LIPSS) and square-shaped micropillars. For the fast and efficient production of these surfaces, the unique combination of high energy ultrashort pulsed laser system with multi-beam and beamshaping technology was applied, resulting in increased productivity by 526% for micropillars and 14 570% for LIPSS compared to single beam methods.In vitroanalysis revealed that micro and nanostructured surfaces provide a better environment for cell attachment and proliferation compared to untreated ones, showing an increase of up to 496% in the number of cells compared to the reference. Moreover, the combination of LIPSS and micropillars resulted in a precise cell orientation along the periodic microgroove pattern. The combination of these results demonstrates the possibility of mass production of functionalized implants with control over cell organization and growth. Thus, reducing the risk of implant failure due to low biocompatibility.
Bacillus toyonensis (a Gram-positive bacterium) and Pseudomonas aeruginosa (a Gram-negative bacterium) isolated from the different surfaces of a dairy plant in our previous study were selected as the test bacteria for the present study. These two test bacteria were investigated in terms of their attachment on the stainless steel test surfaces in a model dairy batch system. After incubation at 5 °C and 20 °C for 6 h, 12 h, and 24 h, stainless steel plates were examined using cultural counts, profilometer, scanning electron microscopy (SEM), and fluorescent microscopy. Also, the test plates were subjected to a cleaning/disinfection procedure used in the dairy plant. Tests were employed before and after the cleaning/disinfection procedures. Cell wall characteristics and holding temperature were found to be significant for the attachment of the test bacteria to stainless steel test surfaces. In the study, the effect of the holding temperature varied depending on the type and characteristics of the bacteria. The adhesion ability of P. aeruginosa was higher than that of B. toyonensis. Increases in the holding temperature may increase the adhesion ability of the bacteria. Milk growth medium was found to be more successful in preventing the attachment ability of P. aeruginosa compared to B. toyonensis. This indicates that the chemical characteristic of the contact material may affect adhesion. The adhered bacterial cells were entirely removed by means of the cleaning/disinfection treatment. Therefore, the adhesion of bacterial cells could be explained as "initial phase of biofilm formation." It can be concluded that the microorganism cell adhesion on the surface is followed by biofilm formation, and this situation lasts for many years. These results reveal the importance of controlling biofilm formation in dairy plants from the beginning.
- MeSH
- Bacillus MeSH
- bakteriální adheze MeSH
- biofilmy MeSH
- nerezavějící ocel * MeSH
- Pseudomonas aeruginosa * MeSH
- Publikační typ
- časopisecké články MeSH
Biofilm formation (BF) and production in the food processing industry (FPI) is a continual threat to food safety and quality. Various bacterial pathogens possess the ability to adhere and produce biofilms on stainless steel (SS) in the FPI due to flagella, curli, pili, fimbrial adhesins, extra polymeric substances, and surface proteins. The facilitating environmental conditions (temperature, pressure, variations in climatic conditions), SS properties (surface energy, hydrophobicity, surface roughness, topography), type of raw food materials, pre-processing, and processing conditions play a significant role in the enhancement of bacterial adhesion and favorable condition for BF. Furthermore, biofilm formers can tolerate different sanitizers and cleaning agents due to the constituents, concentration, contact time, bacterial cluster distribution, and composition of bacteria within the biofilm. Also, bacterial biofilms' ability to produce various endotoxins and exotoxins when consumed cause food infections and intoxications with serious health implications. It is thus crucial to understand BF's repercussions and develop effective interventions against these phenomena that make persistent pathogens difficult to remove in the food processing environment.
- MeSH
- bakteriální adheze MeSH
- bakteriální infekce prevence a kontrola přenos MeSH
- biofilmy * růst a vývoj MeSH
- dezinfekce MeSH
- fyziologie bakterií * MeSH
- lidé MeSH
- manipulace s potravinami * přístrojové vybavení normy MeSH
- nerezavějící ocel * MeSH
- potravinářská mikrobiologie * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
OBJECTIVE: Antineoplastic drugs (ADs) pose risks to healthcare staff. Surface disinfectants are used in hospitals to prevent microbial contamination but the efficiency of disinfectants to degrade ADs is not known. We studied nine disinfectants on ten ADs in the standardized laboratory and realistic in situ hospital conditions. METHODS: A survey in 43 hospitals prioritized nine most commonly used disinfections based on different ingredients. These were tested on inert stainless steel and in situ on contaminated hospital flooring. The effects against ten ADs were studied by LC-MS/MS (Cyclophosphamide CP; Ifosfamide IF; Capecitabine CAP; Sunitinib SUN; Methotrexate MET; Doxorubicin DOX; Irinotecan IRI; Paclitaxel PX; 5-Fluorouracil FU) and ICP-MS (Pt as a marker of platinum-based ADs). RESULTS: Monitoring of the floor contamination in 26 hospitals showed that the most contaminated are the outpatient clinics that suffer from a large turnover of staff and patients and have limited preventive measures. The most frequent ADs were Pt, PX, FU and CP with maxima exceeding the recommended 1 ng/cm2 limit by up to 140 times. IRI, FU, MET, DOX and SUN were efficiently removed by hydrolysis in clean water and present thus lower occupational risk. Disinfectants based on hydrogen peroxide were efficient against PX and FU (> 70% degradation) but less against other ADs, such as carcinogenic CP or IF, IRI and CAP. The most efficient were the active chlorine and peracetic acid-based products, which however release irritating toxic vapors. The innovative in situ testing of ADs previously accumulated in hospital flooring showed highly problematic removal of carcinogenic CP and showed that alcohol-based disinfectants may mobilize persistent ADs contamination from deeper floor layers. CONCLUSION: Agents based on hydrogen peroxide, peracetic acid, quaternary ammonium salts, glutaraldehyde, glucoprotamine or detergents can be recommended for daily use for both disinfection and AD decontamination. However, they have variable efficiencies and should be supplemented by periodic use of strong chlorine-based disinfectants efficient also against the carcinogenic and persistent CP.
- MeSH
- antitumorózní látky * MeSH
- dekontaminace metody MeSH
- detergenty MeSH
- dezinficiencia * MeSH
- diaminy MeSH
- glutaraldehyd MeSH
- kontaminace zdravotnického vybavení MeSH
- kvartérní amoniové sloučeniny MeSH
- kyselina peroctová MeSH
- laboratoře MeSH
- nemocnice MeSH
- nerezavějící ocel MeSH
- peroxid vodíku MeSH
- podlahy a podlahové krytiny MeSH
- pyrrolidinony MeSH
- Publikační typ
- časopisecké články MeSH
Incomplete endothelialization of intracoronary stents has been associated with stent thrombosis and recurrent symptoms, whereas prolonged use of dual antiplatelet therapy increases bleeding-related adverse events. Facilitated endothelialization has the potential to improve clinical outcomes in patients who are unable to tolerate dual antiplatelet therapy. The objective of this study was to demonstrate the feasibility of magnetic cell capture to rapidly endothelialize intracoronary stents in a large animal model. A novel stent was developed from a magnetizable duplex stainless steel (2205 SS). Polylactic-co-glycolic acid and magnetite (Fe3O4) were used to synthesize biodegradable superparamagnetic iron oxide nanoparticles, and these were used to label autologous blood outgrowth endothelial cells. Magnetic 2205 SS and nonmagnetic 316L SS control stents were implanted in the coronary arteries of pigs (n = 11), followed by intracoronary delivery of magnetically labeled cells to 2205 SS stents. In this study, we show extensive endothelialization of magnetic 2205 SS stents (median 98.4% cell coverage) within 3 days, whereas the control 316L SS stents exhibited significantly less coverage (median 48.9% cell coverage, p < 0.0001). This demonstrates the ability of intracoronary delivery of magnetic nanoparticle labeled autologous endothelial cells to improve endothelialization of magnetized coronary stents within 3 days of implantation.
- MeSH
- endoteliální buňky cytologie účinky léků ultrastruktura MeSH
- fenotyp MeSH
- kovy chemie MeSH
- nanočástice chemie ultrastruktura MeSH
- nerezavějící ocel farmakologie MeSH
- prasata MeSH
- stenty * MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
This paper investigates the interaction of human osteoblast-like Saos-2 cells with stainless steel covered by a film of densely inter-grown silicalite-1 crystals with defined outer and inner surfaces. The chemical composition of this film, labeled as SF(RT), was tuned by heat treatment at 300°C and 500°C (labeled as SF(300) and SF(500), respectively) and characterized by X-ray photoelectron spectroscopy (XPS), water drop contact angle (WCA) measurements and scanning electron microscopy (SEM). The number, the spreading area and the activity of alkaline phosphatase of human osteoblast-like Saos-2 cells in cultures on the silicalite-1 film were affected by the chemical composition of its outer surface and by its micro-porous structure. The number and the spreading area of the adhered osteoblast-like cells on day 1 was highest on the surface of SF(RT) relative to their adhesion and spreading on a glass cover slip due to the SF(RT) topology. However, SF(300) markedly supported cell growth during days 3 and 7 after seeding.
Recently, porous metallic materials have been extensively studied as candidates for use in the fabrication of scaffolds and augmentations to repair trabecular bone defects, e.g. in surroundings of joint replacements. Fabricating these complex structures by using common approaches (e.g., casting and machining) is very challenging. Therefore, rapid prototyping techniques, such as selective laser melting (SLM), have been investigated for these applications. In this study, we characterized a highly porous (87 vol.%) 316L stainless steel scaffold prepared by SLM. 316L steel was chosen because it presents a biomaterial still widely used for fabrication of joint replacements and, from the practical point of view, use of the same material for fabrication of an augmentation and a joint replacement is beneficial for corrosion prevention. The results are compared to the reported properties of two representative nonporous 316L stainless steels prepared either by SLM or casting and subsequent hot forging. The microstructural and mechanical properties and the surface chemical composition and interaction with the cells were investigated. The studied material exhibited mechanical properties that were similar to those of trabecular bone (compressive modulus of elasticity ~0.15GPa, compressive yield strength ~3MPa) and cytocompatibility after one day that was similar to that of wrought 316L stainless steel, which is a commonly used biomaterial. Based on the obtained results, SLM is a suitable method for the fabrication of porous 316L stainless steel scaffolds with highly porous structures.
- MeSH
- fotoelektronová spektroskopie MeSH
- lasery * MeSH
- lidé MeSH
- modul pružnosti účinky léků MeSH
- nádorové buněčné linie MeSH
- nerezavějící ocel farmakologie MeSH
- pevnost v tahu účinky léků MeSH
- poréznost MeSH
- povrchové vlastnosti MeSH
- testování materiálů metody MeSH
- tvar buňky MeSH
- železo farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
It is demonstrated that numerous bacteria are able to attach to surfaces of equipment used for food handling or processing. In this study, a strain of Enterococcus durans, originally isolated from a milking machine surface, was firstly studied for its biofilm formation potential on plastic and stainless steel supports. The strain was found to be a biofilm producer either at 25, 30 or 37 °C on polystyrene microtitre plates, with a best adherence level observed at 25 °C. En. durans showed a strong adhesion to stainless steel AISI-304. Antibacterial and anti-adherence activities of En. durans were tested against four foodborne pathogens (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853 and Listeria innocua CLIP 74915) which were shown as biofilm producers on both plastic and stainless steel. En. durans cells and cell-free culture supernatant showed a significant (P < 0.05) inhibition potential of the pathogens either on solid media or in broth co-cultures. Characterization of the antibacterial substances indicated their proteinaceous nature which assigned them most probably to bacteriocins group.
- MeSH
- bakteriální adheze účinky léků MeSH
- bakteriální proteiny metabolismus MeSH
- biofilmy účinky léků MeSH
- biologické přípravky metabolismus MeSH
- Enterococcus metabolismus fyziologie MeSH
- gramnegativní bakterie účinky léků fyziologie MeSH
- grampozitivní bakterie účinky léků fyziologie MeSH
- mikrobiologie životního prostředí * MeSH
- nerezavějící ocel MeSH
- plastické hmoty MeSH
- potravinářská mikrobiologie MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
Cíl práce: Účelem této studie bylo detekování biofilmu patogenních mikroorganismů vyskytujících se v potravinářském průmyslu a porovnání jeho tvorby při různých kultivačních podmínkách. Materiál a metody: Ke studii byly zvoleny následující mikroorganismy – Staphylococcus aureus, Listeria innocua, Listeria ivanovii, Cronobacter sakazakii, Cronobacter muyt-jensii, Arcobacter butzleri, Arcobacter cryaerophilus, Campylobacter jejuni a Campylobacter coli. Pro detekci biofilmu vybraných mikroorganismů byla použita Christensenova metoda v mikrotitračních destičkách a metoda kultivace na kuponech z nerezové oceli. Výsledky: U všech sledovaných mikroorganismů byla potvrzena schopnost tvorby biofilmu, a to jak v mikrotitračních destičkách, tak na kuponech z nerezové oceli. Tvorba biofilmu byla ovlivněna jak kultivačním médiem, použitým materiálem a dobou kultivace, tak samotným mikroorganismem. Bylo prokázáno, že různé druhy a kmeny téhož rodu tvoří biofilm rozdílně. Rozdíl byl zjištěn i při porovnání sbírkových kultur a izolátů z prostředí. Některé bakterie tvořily biofilm ve větší míře na povrchu polyetylenových mikrotitračních destiček a na nerezových kuponech pak méně, nebo tomu bylo naopak. Některé patogeny byly schopny zvýšit denzitu planktonních buněk původní suspenze během 72 hodin až o 3 řády a zároveň vytvořit velké množství biofilmu. Závěry: Sledování tvorby biofilmu obávaných patogenů je velice důležité, a to nejen v potravinářském průmyslu. Podle získaných výsledků je zřejmé, že se bakteriální biofilmy formují již po relativně krátkém čase (v našem případě 24 hodin). Vzhledem ke struktuře těchto biofilmů je jejich likvidace velice náročná, je tedy žádoucí předcházet samotnému vzniku biofilmu. Klíčová slova: nerezová ocel – biofilm – patogeny – planktonní buňky – mikrotitrační destička
Objective: Detection of biofilm formation by microbial pathogens relevant to the food industry and comparison of biofilm formation under different conditions of culture. Material and methods: The following microorganisms were selected for the study: Staphylococcus aureus, Listeria innocua, Listeria ivanovii, Cronobacter sakazakii, Cronobacter muytjensii, Arcobacter butzleri, Arcobacter cryaerophilus, Campylobacter jejuni, and Campylobacter coli. To detect biofilm formation the microtiter plate assay, as described by Christensen and culture on stainless steel coupons were used. Results: The biofilm forming capacity was confirmed in all microorganisms tested, both on the microtiter plates and stainless steel coupons. Biofilm formation was influenced by the culture medium, material used, and culture duration as well as by the test microorganism. It was found that different species and strains of the same genus differ in biofilm formation. Differences were also found between the collection strains and isolates from the environment. Some bacteria tended to form biofilm more readily on the surface of the polyethylene microtiter plates and less readily on stainless steel coupons while others appeared to have an opposite tendency. Some pathogens were able to increase the planktonic cell density in the initial suspension even by three orders of magnitude within 72 hours while producing plenty of biofilm. Conclusions: The study of biofilm formation by high risk pathogens is of utmost importance, not only to the food industry. From the obtained results, it is evident that bacterial biofilms form rapidly (within 24 hours in the present study). Due to their architecture, these biofilms are difficult to eradi-cate, and therefore, it is crucial to prevent biofilm formation. Keywords: stainless steel – biofilm – pathogens – planktonic cells – microtiter plate
- Klíčová slova
- planktonní buňky, mikrotitrační destička,
- MeSH
- Arcobacter fyziologie růst a vývoj MeSH
- bakteriální adheze MeSH
- biofilmy * růst a vývoj MeSH
- Campylobacter coli fyziologie růst a vývoj MeSH
- Campylobacter jejuni fyziologie růst a vývoj MeSH
- časové faktory MeSH
- Cronobacter sakazakii fyziologie růst a vývoj MeSH
- Cronobacter fyziologie růst a vývoj MeSH
- kultivační techniky metody statistika a číselné údaje MeSH
- Listeria fyziologie růst a vývoj MeSH
- nerezavějící ocel * MeSH
- potravinářská mikrobiologie * MeSH
- potravinářský průmysl MeSH
- povrchové vlastnosti MeSH
- Staphylococcus aureus fyziologie růst a vývoj MeSH
- Publikační typ
- práce podpořená grantem MeSH
- srovnávací studie MeSH
