Legionella pneumophila can cause a potentially fatal form of humane pneumonia (Legionnaires' disease), which is most problematic in immunocompromised and in elderly people. Legionella species is ...present at low concentrations in soil, natural and artificial aquatic systems and is therefore constantly entering man-made water systems. The environment temperature for it's ideal growth range is between 32 and 42°C, thus hot water pipes represent ideal environment for spread of Legionella. The bacteria are dormant below 20°C and do not survive above 60°C. The primary method used to control the risk from Legionella is therefore water temperature control. There are several other effective treatments to prevent growth of Legionella in water systems, however current disinfection methods can be applied only intermittently thus allowing Legionella to grow in between treatments. Here we present an alternative disinfection method based on antibacterial coatings with Cu-TiO2 nanotubes deposited on preformed surfaces. In the experiment the microbiocidal efficiency of submicron coatings on polystyrene to the bacterium of the genus Legionella pneumophila with a potential use in a water supply system was tested. The treatment thus constantly prevents growth of Legionella pneumophila in presence of water at room temperature. Here we show that 24-hour illumination with low power UVA light source (15 W/m2 UVA illumination) of copper doped TiO2 nanotube coated surfaces is effective in preventing growth of Legionella pneumophila. Microbiocidal effects of Cu-TiO2 nanotube coatings were dependent on the flow of the medium and the intensity of UV-A light. It was determined that tested submicron coatings have microbiocidal effects specially in a non-flow or low-flow conditions, as in higher flow rates, probably to a greater possibility of Legionella pneumophila sedimentation on the coated polystyrene surfaces, meanwhile no significant differences among bacteria reduction was noted regarding to non or low flow of medium.
High economic burden is associated with foodborne illnesses. Different disinfection methods are therefore employed in food processing industry; such as use of ultraviolet light or usage of surfaces ...with copper-containing alloys. However, all the disinfection methods currently in use have some shortcomings. In this work we show that copper doped TiO2 nanotubes deposited on existing surfaces and illuminated with ceiling mounted fluorescent lights can retard the growth of Listeria Innocua by 80% in seven hours of exposure to the fluorescent lights at different places in a food processing plant or in the laboratory conditions with daily reinocuation and washing. The disinfection properties of the surfaces seem to depend mainly on the temperature difference of the surface and the dew point, where for the maximum effectiveness the difference should be about 3 degrees celsius. The TiO2 nanotubes have a potential to be employed for an economical and continuous disinfection of surfaces.
Bacterial infections acquired in healthcare facilities including hospitals, the so called healthcare acquired or nosocomial infections, are still of great concern worldwide and represent a ...significant economical burden. One of the major causes of morbidity is infection with Methicillin Resistant Staphylococcus aureus (MRSA), which has been reported to survive on surfaces for several months. Bactericidal activity of copper-TiO2 thin films, which release copper ions and are deposited on glass surfaces and heated to high temperatures, is well known even when illuminated with very weak UVA light of about 10 μW/cm2. Lately, there is an increased intrerest for one-dimensional TiO2 nanomaterials, due to their unique properties, low cost, and high thermal and photochemical stability. Here we show that copper doped TiO2 nanotubes produce about five times more ·OH radicals as compared to undoped TiO2 nanotubes and that effective surface disinfection, determined by a modified ISO 22196:2011 test, can be achieved even at low intensity UVA light of 30 μW/cm2. The nanotubes can be deposited on a preformed surface at room temperature, resulting in a stable deposition resistant to multiple washings. Up to 103 microorganisms per cm2 can be inactivated in 24 hours, including resistant strains such as Methicillin-resistant Staphylococcus aureus (MRSA) and Extended-spectrum beta-lactamase Escherichia coli (E. coli ESBL). This disinfection method could provide a valuable alternative to the current surface disinfection methods.
High economic burden is associated with foodborne illnesses. Different disinfection methods are therefore employed in food processing industry; such as use of ultraviolet light or usage of surfaces ...with copper-containing alloys. However, all the disinfection methods currently in use have some shortcomings. In this work we show that copper doped TiO.sub.2 nanotubes deposited on existing surfaces and illuminated with ceiling mounted fluorescent lights can retard the growth of Listeria Innocua by 80% in seven hours of exposure to the fluorescent lights at different places in a food processing plant or in the laboratory conditions with daily reinocuation and washing. The disinfection properties of the surfaces seem to depend mainly on the temperature difference of the surface and the dew point, where for the maximum effectiveness the difference should be about 3 degrees celsius. The TiO.sub.2 nanotubes have a potential to be employed for an economical and continuous disinfection of surfaces.
Bacterial infections acquired in healthcare facilities including hospitals, the so called healthcare acquired or nosocomial infections, are still of great concern worldwide and represent a ...significant economical burden. One of the major causes of morbidity is infection with Methicillin Resistant Staphylococcus aureus (MRSA), which has been reported to survive on surfaces for several months. Bactericidal activity of copper-TiO.sub.2 thin films, which release copper ions and are deposited on glass surfaces and heated to high temperatures, is well known even when illuminated with very weak UVA light of about 10 muW/cm.sup.2 . Lately, there is an increased intrerest for one-dimensional TiO.sub.2 nanomaterials, due to their unique properties, low cost, and high thermal and photochemical stability. Here we show that copper doped TiO.sub.2 nanotubes produce about five times more ·OH radicals as compared to undoped TiO.sub.2 nanotubes and that effective surface disinfection, determined by a modified ISO 22196:2011 test, can be achieved even at low intensity UVA light of 30 muW/cm.sup.2 . The nanotubes can be deposited on a preformed surface at room temperature, resulting in a stable deposition resistant to multiple washings. Up to 10.sup.3 microorganisms per cm.sup.2 can be inactivated in 24 hours, including resistant strains such as Methicillin-resistant Staphylococcus aureus (MRSA) and Extended-spectrum beta-lactamase Escherichia coli (E. coli ESBL). This disinfection method could provide a valuable alternative to the current surface disinfection methods.
Airborne Listeria spp. in the red meat processing industry Dobeic, M.,University of Ljubljana (Slovenia). Inst. for Environmental and Animal Hygiene with Ethology; Kenda, E.,University of Ljubljana (Slovenia). Inst. for Environmental and Animal Hygiene with Ethology; Micunovic, J.,University of Ljubljana (Slovenia). Inst. for Microbiology and Parasitology ...
Czech Journal of Food Sciences,
01/2011, Letnik:
29, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The aim of this study was to determine the potential presence of the airborne Listeria spp. and its correlation with the aerobic mesophilic bacteria and Listeria carcass contamination in three red ...meat slaughtering and three processing plants. Airborne L. seeligeri and L. innocua were determined using 8 (5.06%, n = 158) air samples taken on the locations characteristic for aerosol generating and in a chilly environment. The positive airborne samples of Listeria spp. were in an insignificant relation with the highest airborne bacteria counts. On the carcass, only 1 positive case (n = 144) of L. innocua was determined, presumably owing to the low airborne Listeria counts and its unpredictable settling rates. In addition, insignificant influences of air moisture and airflow on the airborne Listeria were found.
•The fate of lasalocid in poultry manure and on arable land is largely unknown.•We measured lasalocid degradation in manure and compost and dissipation on land.•Degradation in compost is faster than ...in manure.•Half-life of lasalocid in soil was 3.1±0.6d.•PEC/PNEC in soil could exceed 1 in a worst-case scenario if manure is not aged.
Lasalocid is a veterinary ionophore antibiotic used for prevention and treatment of coccidiosis in poultry. It is excreted from the treated animals mostly in its active form and enters the environment with the use of contaminated manure on agricultural land. To properly assess the risk that lasalocid poses to the environment, it is necessary to know its environmental concentrations as well as the rates of its degradation in manure and dissipation in soil. These values are still largely unknown. A research was undertaken to ascertain the rate of lasalocid degradation in manure under different storage conditions (aging in a pile or composting) and on agricultural soil after using lasalocid-contaminated manure. The results have shown that there is considerable difference in lasalocid degradation between aging manure with no treatment (t1/2=61.8±1.7d) and composting (t1/2=17.5±0.8d). Half-lives in soil are much shorter (on average 3.1±0.4d). On the basis of the measured concentrations of lasalocid in soil after manure application, we can conclude that it can potentially be harmful to soil organisms (PEC/PNEC ratio of 1.18), but only in a worst-case scenario of using the maximum permissible amount of manure and immediately after application. To make certain that no harmful effects occur, composting is recommended.
In the European Union, eggs may not be washed or cleaned. So, in order to reduce food safety risks, several techniques for eggs in shell decontamination have been developed. The current study was ...undertaken to determine the potential of the Non-thermal, Atmospheric, Openair® Plasma Jet for surface decontamination of eggs in shell. In the experiment Polyethylene Theraphtalate plates and the eggshells of table eggs were exposed to single or multiple treatments with a Non-thermal, Atmospheric, Openair® Plasma Jet. This resulted in up to > 3 log reduction of Staphylococcus aureus (S. aureus) (NCTC 8325) on Polyethylene Theraphtalate and 1.8–2.5 log reduction of a common number of native aerobic mesophylic bacteria and S. aureus (NCTC 8325) on eggshells in a treatment time of 10-60 seconds. Ionising gas of the plasma jet was obviously not harmful to eggshell cuticle, since no significant alterations to plasma-treated eggs were found, or to physico-chemical properties of the contents of plasma-treated eggs, such as: air cell height, pH, the whole weight of eggs, or height of the thickness of egg white, which did not significantly differ from the untreated eggs during 54 days of aging. The results of the experiment indicate that the treatment of eggshells with the plasma jet has the potential for egg in shell decontamination with no side effects on egg quality, which is important as far as food safety and quality characteristics that are acceptable to consumers.
Pigeon circovirus (PiCV) was detected by real-time PCR in cloacal swabs, pharyngeal swabs, and serum samples taken from 74 feral pigeons (Columba livia var. domestica) that were caught at various ...locations in the city of Ljubljana, Slovenia. PiCV infections were detected in the majority of the tested birds. The highest (74.3%) detection rate was observed in the cloacal swabs and the lowest (31.1%) in serum samples. PiCV DNA was more readily detected in the cloacal swabs, pharyngeal swabs, and serum samples of birds younger than 1 yr. Molecular analysis of partial open reading frame V1 sequences showed that PiCV strains detected in feral pigeons share high nucleotide and amino acid sequence identities with PiCV strains detected in ornamental, racing, meat, and feral pigeons. Reporte de Caso—Prevalencia de las infecciones asociadas con circovirus de las paloma en las palomas en libertad en Ljubljana, Eslovenia. El circovirus de las palomas (PiCV) fue detectado por PCR en tiempo real en hisopos cloacales, hisopos faríngeos y en muestras de suero tomadas de 74 palomas en libertad (Columba livia var. domestica) que fueron capturadas en distintos lugares de la ciudad de Ljubljana, Eslovenia. Se detectó la infección por el circovirus de las palomas en la mayoría de las aves analizadas. El porcentaje de detección más alto (74.3%) se observó en los hisopos cloacales y la más baja (31.1%) en muestras de suero. El ADN del circovirus de las palomas fue detectado más fácilmente en los hisopos cloacales, hisopos faríngeos y en muestras de suero de las aves menores de un año. El análisis molecular de las secuencias parciales del marco de lectura continua V1 mostró que las cepas de circovirus detectadas en las palomas en libertad comparten altas identidades en las secuencias de nucleótidos y de aminoácidos con las cepas de circovirus detectadas en palomas ornamentales, de competencia, productoras de carne y salvajes.
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