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Sample records for inactivate blood-borne pathogens

  1. Protecting Adults and Children from Blood-Borne Pathogens.

    Science.gov (United States)

    Freeman, Nancy K.; Corning, Lisa L.

    2000-01-01

    Recommends universal precautions policies and procedures to minimize for children and adults in early childhood settings the risk of infection from exposure to blood-borne pathogens such as hepatitis B or HIV. Outlines symptoms of hepatitis B and HIV/AIDS. Discusses legal and ethical implications related to inclusion. Lists resources for teachers…

  2. Are your employees protected from blood-borne pathogens? OSHA standards charge textile rental companies with responsibility for worker safety.

    Science.gov (United States)

    Weller, S C

    1991-11-01

    Congress is putting pressure on OSHA to finalize its Universal Precaution standards by December. When the standards go into effect, textile rental companies that serve medical, dental, and outpatient care facilities--including private physician and dentist offices--must take steps to protect employees from blood-borne pathogens. Soiled linens, towels, gowns, and other items from any customer in risk categories link a textile rental facility and/or commercial laundry with the OSHA regulations. Read and heed this information.

  3. Pathogen inactivation techniques.

    Science.gov (United States)

    Pelletier, J P R; Transue, S; Snyder, E L

    2006-01-01

    The desire to rid the blood supply of pathogens of all types has led to the development of many technologies aimed at the same goal--eradication of the pathogen(s) without harming the blood cells or generating toxic chemical agents. This is a very ambitious goal, and one that has yet to be achieved. One approach is to shun the 'one size fits all' concept and to target pathogen-reduction agents at the Individual component types. This permits the development of technologies that might be compatible with, for example, plasma products but that would be cytocidal and thus incompatible with platelet concentrates or red blood cell units. The technologies to be discussed include solvent detergent and methylene blue treatments--designed to inactivate plasma components and derivatives; psoralens (S-59--amotosalen) designed to pathogen-reduce units of platelets; and two products aimed at red blood cells, S-303 (a Frale--frangible anchor-linker effector compound) and Inactine (a binary ethyleneimine). A final pathogen-reduction material that might actually allow one material to inactivate all three blood components--riboflavin (vitamin B2)--is also under development. The sites of action of the amotosalen (S-59), the S-303 Frale, Inactine, and riboflavin are all localized in the nucleic acid part of the pathogen. Solvent detergent materials act by dissolving the plasma envelope, thus compromising the integrity of the pathogen membrane and rendering it non-infectious. By disrupting the pathogen's ability to replicate or survive, its infectivity is removed. The degree to which bacteria and viruses are affected by a particular pathogen-reducing technology relates to its Gram-positive or Gram-negative status, to the sporulation characteristics for bacteria, and the presence of lipid or protein envelopes for viruses. Concerns related to photoproducts and other breakdown products of these technologies remain, and the toxicology of pathogen-reduction treatments is a major ongoing area

  4. Fibrinolysis and proliferative endarteritis: two related processes in chronic infections? The model of the blood-borne pathogen Dirofilaria immitis.

    Directory of Open Access Journals (Sweden)

    Javier González-Miguel

    Full Text Available The interaction between blood-borne pathogens and fibrinolysis is one of the most important mechanisms that mediate invasion and the establishment of infectious agents in their hosts. However, overproduction of plasmin (final product of the route has been related in other contexts to proliferation and migration of the arterial wall cells and degradation of the extracellular matrix. We have recently identified fibrinolysis-activating antigens from Dirofilaria immitis, a blood-borne parasite whose key pathological event (proliferative endarteritis is produced by similar mechanisms to those indicated above. The objective of this work is to study how two of this antigens [actin (ACT and fructose-bisphosphate aldolase (FBAL] highly conserved in pathogens, activate fibrinolysis and to establish a relationship between this activation and the development of proliferative endarteritis during cardiopulmonary dirofilariasis. We demonstrate that both proteins bind plasminogen, enhance plasmin generation, stimulate the expression of the fibrinolytic activators tPA and uPA in endothelial cell cultures and are located on the surface of the worm in contact with the host's blood. ELISA, western blot and immunofluorescence techniques were employed for this purpose. Additionally, the implication of lysine residues in this interaction was analyzed by bioinformatics. The involvement of plasmin generated by the ACT/FBAL and plasminogen binding in cell proliferation and migration, and degradation of the extracellular matrix were shown in an "in vitro" model of endothelial and smooth muscle cells in culture. The obtained results indicate that ACT and FBAL from D. immitis activate fibrinolysis, which could be used by the parasite like a survival mechanism to avoid the clot formation. However, long-term overproduction of plasmin can trigger pathological events similar to those described in the emergence of proliferative endarteritis. Due to the high degree of

  5. Biocontrol interventions for inactivation of foodborne pathogens on produce

    Science.gov (United States)

    Post-harvest interventions for control of foodborne pathogens on minimally processed foods are crucial for food safety. Biocontrol interventions have the primary objective of developing novel antagonists in combinations with physical and chemical interventions to inactivate pathogenic microbes. Ther...

  6. Photodynamic inactivation of pathogens causing infectious keratitis

    Science.gov (United States)

    Simon, Carole; Wolf, G.; Walther, M.; Winkler, K.; Finke, M.; Hüttenberger, D.; Bischoff, Markus; Seitz, B.; Cullum, J.; Foth, H.-J.

    2014-03-01

    The increasing prevalence of antibiotic resistance requires new approaches also for the treatment of infectious keratitis. Photodynamic Inactivation (PDI) using the photosensitizer (PS) Chlorin e6 (Ce6) was investigated as an alternative to antibiotic treatment. An in-vitro cornea model was established using porcine eyes. The uptake of Ce6 by bacteria and the diffusion of the PS in the individual layers of corneal tissue were investigated by fluorescence. After removal of the cornea's epithelium Ce6-concentrations tested in liquid culture against different concentrations of Ce6 (1 - 512 μM) using 10 minutes irradiation (E = 18 J/cm2 ). This demonstrated that a complete inactivation of the pathogen strains were feasible whereby SA was slightly more susceptible than PA. 3909 mutants of the Keio collection of Escherichia coli (E.coli) were screened for potential resistance factors. The sensitive mutants can be grouped into three categories: transport mutants, mutants in lipopolysaccharide synthesis and mutants in the bacterial SOS-response. In conclusion PDI is seen as a promising therapy concept for infectious keratitis.

  7. Photodynamic inactivation of antibiotic-resistant pathogens

    International Nuclear Information System (INIS)

    Paronyan, M.H.

    2015-01-01

    Nowadays methicillin-resistant strain Staphylococcus aureus (MRSA) is one of the most widespread multiresistant bacteria. Photodynamic inactivation (PDI) of microorganisms by photosensitizers (PS) may be an effective and alternative therapeutic option against antibiotic resistant bacteria. The effectiveness of new PS cationic porphyrin Zn-TBut4PyP was tested on two strains of S. aureus (MRSA and methicillin-sensitive S. aureus). It is shown that Zn-TBut4PyP has high photodynamic activity against both strains

  8. Laser inactivation of pathogenic viruses in water

    Science.gov (United States)

    Grishkanich, Alexander; Zhevlakov, Alexander; Kascheev, Sergey; Sidorov, Igor; Ruzankina, Julia; Yakovlev, Alexey; Mak, Andrey

    2016-03-01

    Currently there is a situation that makes it difficult to provide the population with quality drinking water for the sanitary-hygienic requirements. One of the urgent problems is the need for water disinfection. Since the emergence of microorganisms that are pathogens transmitted through water such as typhoid, cholera, etc. requires constant cleansing of waters against pathogenic bacteria. In the water treatment process is destroyed up to 98% of germs, but among the remaining can be pathogenic viruses, the destruction of which requires special handling. As a result, the conducted research the following methods have been proposed for combating harmful microorganisms: sterilization of water by laser radiation and using a UV lamp.

  9. Inactivation of dairy manure-borne pathogens by anaerobic digestion

    Science.gov (United States)

    Background: Anaerobic digestion of animal manure has the potential to inactivate enteric pathogens, thereby reducing exposures to livestock and humans when the products of digestion are disposed by land-spreading or irrigation or returned to livestock uses such as bedding. Data on digester effectiv...

  10. UV inactivation of pathogenic and indicator microorganisms

    International Nuclear Information System (INIS)

    Chang, J.C.; Ossoff, S.F.; Lobe, D.C.; Dorfman, M.H.; Dumais, C.M.; Qualls, R.G.; Johnson, J.D.

    1985-01-01

    Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts

  11. UV inactivation of pathogenic and indicator microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Chang, J.C.; Ossoff, S.F.; Lobe, D.C.; Dorfman, M.H.; Dumais, C.M.; Qualls, R.G.; Johnson, J.D.

    1985-06-01

    Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts.

  12. Pathogen Inactivated Plasma Concentrated: Preparation and Uses

    Science.gov (United States)

    2004-09-01

    of decontamination, porcine parvovirus (PPV) was selected as a model virus; B19 is the form that infects humans. PPV is an interesting pathogen...ultrasound to cold plasma. The ultrasound generates pure ice crystals, which are then removed to leave concentrated plasma. Testing: Porcine parvovirus ...energy to “burn” any proteins that they encounter. Furthermore, as they react, they also produce multiple other reactive oxygen species (ROS) that are

  13. Inactivation of pathogenic bacteria in food matrices: high pressure processing, photodynamic inactivation and pressure-assisted photodynamic inactivation

    Science.gov (United States)

    Cunha, A.; Couceiro, J.; Bonifácio, D.; Martins, C.; Almeida, A.; Neves, M. G. P. M. S.; Faustino, M. A. F.; Saraiva, J. A.

    2017-09-01

    Traditional food processing methods frequently depend on the application of high temperature. However, heat may cause undesirable changes in food properties and often has a negative impact on nutritional value and organoleptic characteristics. Therefore, reducing the microbial load without compromising the desirable properties of food products is still a technological challenge. High-pressure processing (HPP) can be classified as a cold pasteurization technique, since it is a non-thermal food preservation method that uses hydrostatic pressure to inactivate spoilage microorganisms. At the same time, it increases shelf life and retains the original features of food. Photodynamic inactivation (PDI) is also regarded as promising approach for the decontamination of food matrices. In this case, the inactivation of bacterial cells is achieved by the cytotoxic effects of reactive oxygens species (ROS) produced from the combined interaction of a photosensitizer molecule, light and oxygen. This short review examines some recent developments on the application of HPP and PDI with food-grade photosensitizers for the inactivation of listeriae, taken as a food pathogen model. The results of a proof-of-concept trial of the use of high-pressure as a coadjutant to increase the efficiency of photodynamic inactivation of bacterial endospores is also addressed.

  14. Human milk inactivates pathogens individually, additively, and synergistically.

    Science.gov (United States)

    Isaacs, Charles E

    2005-05-01

    Breast-feeding can reduce the incidence and the severity of gastrointestinal and respiratory infections in the suckling neonate by providing additional protective factors to the infant's mucosal surfaces. Human milk provides protection against a broad array of infectious agents through redundancy. Protective factors in milk can target multiple early steps in pathogen replication and target each step with more than one antimicrobial compound. The antimicrobial activity in human milk results from protective factors working not only individually but also additively and synergistically. Lipid-dependent antimicrobial activity in milk results from the additive activity of all antimicrobial lipids and not necessarily the concentration of one particular lipid. Antimicrobial milk lipids and peptides can work synergistically to decrease both the concentrations of individual compounds required for protection and, as importantly, greatly reduce the time needed for pathogen inactivation. The more rapidly pathogens are inactivated the less likely they are to establish an infection. The total antimicrobial protection provided by human milk appears to be far more than can be elucidated by examining protective factors individually.

  15. Inactivation of certain insect pathogens by ultraviolet radiation

    International Nuclear Information System (INIS)

    Krieg, A.; Groener, A.; Huber, J.; Zimmermann, G.

    1981-01-01

    The UV-sensitivity of two baculoviruses (granulosis virus, nuclear polyhedrosis virus) and two entomopathogenic microorganisms (Bacillus thuringiensis, Beauveria bassiana) was determined by radiation tests. In the far UV (254 nm) the stability, measured at an inactivation rate of 99%, was in declining order: nuclear polyhedra >= conidia of B. bassiana > granula > spores of B. thuringiensis >= vegetative cells of B. thuringiensis. In the near UV (285-380 nm) the following order could be found: conidia of B. bassiana >= nuclear polyhedra > spores of B. thuringiensis >= granula > vegetative cells of B. thuringiensis. Far UV had a much higher germicidal effect for all pathogens tested than near UV. (orig.) [de

  16. Inactivation of certain insect pathogens by ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Krieg, A.; Groener, A.; Huber, J.; Zimmermann, G.

    1981-01-01

    The UV-sensitivity of two baculoviruses (granulosis virus, nuclear polyhedrosis virus) and two entomopathogenic microorganisms (Bacillus thuringiensis, Beauveria bassiana) was determined by radiation tests. In the far UV (254 nm) the stability, measured at an inactivation rate of 99%, was in declining order: nuclear polyhedra >= conidia of B. bassiana > granula > spores of B. thuringiensis >= vegetative cells of B. thuringiensis. In the near UV (285-380 nm) the following order could be found: conidia of B. bassiana >= nuclear polyhedra > spores of B. thuringiensis >= granula > vegetative cells of B. thuringiensis. Far UV had a much higher germicidal effect for all pathogens tested than near UV.

  17. Inactivation of pathogens on pork by steam-ultrasound treatment

    DEFF Research Database (Denmark)

    Morild, Rikke K; Christiansen, Pia; Sørensen, Anders Morten Hay

    2011-01-01

    The objective of the study was to evaluate a new pathogen inactivation concept that combines application of pressurized steam simultaneously with high-power ultrasound through a series of nozzles. On skin and meat surfaces of pork jowl samples, counts of total viable bacteria were reduced by 1...... in reduction was observed between samples inoculated with 10(4) CFU/cm(2) and those inoculated with 10(7) CFU/cm(2), and cold storage of samples for 24 h at 5°C after steam-ultrasound treatment did not lead to changes in recovery of bacteria....

  18. Reducing Blood-borne Exposure in Interventional Radiology: What the IR Should Know

    Energy Technology Data Exchange (ETDEWEB)

    Tso, David K. [University of British Columbia, Department of Radiology (Canada); Athreya, Sriharsha, E-mail: sathreya@stjoes.ca [St. Joseph' s Healthcare Hamilton, Department of Diagnostic Imaging (Canada)

    2013-08-01

    Interventional radiologists are at risk of exposure to blood-borne pathogens in their day-to-day practice. Percutaneous exposure from unsafe sharps handling, mucocutaneous exposure from body fluid splashes, and glove perforation from excessive wear can expose the radiologist to potentially infectious material. The increasing prevalence of blood-borne pathogens, including hepatitis B and C, and human immunodeficiency virus, puts nurses, residents, fellows, and interventional radiologists at risk for occupational exposure. This review outlines suggestions to establish a culture of safety in the interventional suite.

  19. Cost implications of implementation of pathogen-inactivated platelets.

    Science.gov (United States)

    McCullough, Jeffrey; Goldfinger, Dennis; Gorlin, Jed; Riley, William J; Sandhu, Harpreet; Stowell, Christopher; Ward, Dawn; Clay, Mary; Pulkrabek, Shelley; Chrebtow, Vera; Stassinopoulos, Adonis

    2015-10-01

    Pathogen inactivation (PI) is a new approach to blood safety that may introduce additional costs. This study identifies costs that could be eliminated, thereby mitigating the financial impact. Cost information was obtained from five institutions on tests and procedures (e.g., irradiation) currently performed, that could be eliminated. The impact of increased platelet (PLT) availability due to fewer testing losses, earlier entry into inventory, and fewer outdates with a 7-day shelf life were also estimated. Additional estimates include costs associated with managing (1) special requests and (2) test results, (3) quality control and proficiency testing, (4) equipment acquisition and maintenance, (5) replacement of units lost to positive tests, (6) seasonal or geographic testing, and (7) health department interactions. All costs are mean values per apheresis PLT unit in USD ($/unit). The estimated test costs that could be eliminated are $71.76/unit and a decrease in transfusion reactions corresponds to $2.70/unit. Avoiding new tests (e.g., Babesia and dengue) amounts to $41.80/unit. Elimination of irradiation saves $8.50/unit, while decreased outdating with 7-day storage can be amortized to $16.89/unit. Total potential costs saved with PI is $141.65/unit. Costs are influenced by a variety of factors specific to institutions such as testing practices and the location in which such costs are incurred and careful analysis should be performed. Additional benefits, not quantified, include retention of some currently deferred donors and scheduling flexibility due to 7-day storage. While PI implementation will result in additional costs, there are also potential offsetting cost reductions, especially after 7-day storage licensing. © 2015 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  20. Thermal inactivation of enzymes and pathogens in biosamples for MS analysis.

    Science.gov (United States)

    Ahnoff, Martin; Cazares, Lisa H; Sköld, Karl

    2015-01-01

    Protein denaturation is the common basis for enzyme inactivation and inactivation of pathogens, necessary for preservation and safe handling of biosamples for downstream analysis. While heat-stabilization technology has been used in proteomic and peptidomic research since its introduction in 2009, the advantages of using the technique for simultaneous pathogen inactivation have only recently been addressed. The time required for enzyme inactivation by heat (≈1 min) is short compared with chemical treatments, and inactivation is irreversible in contrast to freezing. Heat stabilization thus facilitates mass spectrometric studies of biomolecules with a fast conversion rate, and expands the chemical space of potential biomarkers to include more short-lived entities, such as phosphorylated proteins, in tissue samples as well as whole-blood (dried blood sample) samples.

  1. MPLEx: a method for simultaneous pathogen inactivation and extraction of samples for multi-omics profiling

    Energy Technology Data Exchange (ETDEWEB)

    Burnum-Johnson, Kristin E.; Kyle, Jennifer E.; Eisfeld, Amie J.; Casey, Cameron P.; Stratton, Kelly G.; Gonzalez, Juan F.; Habyarimana, Fabien; Negretti, Nicholas M.; Sims, Amy C.; Chauhan, Sadhana; Thackray, Larissa B.; Halfmann, Peter J.; Walters, Kevin B.; Kim, Young-Mo; Zink, Erika M.; Nicora, Carrie D.; Weitz, Karl K.; Webb-Robertson, Bobbie-Jo M.; Nakayasu, Ernesto S.; Ahmer, Brian; Konkel, Michael E.; Motin, Vladimir; Baric, Ralph S.; Diamond, Michael S.; Kawaoka, Yoshihiro; Waters, Katrina M.; Smith, Richard D.; Metz, Thomas O.

    2017-01-01

    The continued emergence and spread of infectious agents is of increasing concern due to increased population growth and the associated increased livestock production to meet food demands, increased urbanization and land-use changes, and greater travel. A systems biology approach to infectious disease research can significantly advance our understanding of host-pathogen relationships and facilitate the development of new therapies and vaccines. Molecular characterization of infectious samples outside of appropriate biosafety containment can only take place subsequent to pathogen inactivation. Herein, we describe a modified Folch extraction using chloroform/methanol that facilitates the molecular characterization of infectious samples by enabling simultaneous pathogen inactivation and extraction of proteins, metabolites, and lipids for subsequent mass spectrometry-based multi-omics measurements. This metabolite, protein and lipid extraction (MPLEx) method resulted in complete inactivation of bacterial and viral pathogens with exposed lipid membranes, including Yersinia pestis, Salmonella Typhimurium, and Campylobacter jejuni in pure culture, and Yersinia pestis, Campylobacter jejuni, West Nile, MERS-CoV, Ebola, and influenza H7N9 viruses in infection studies. Partial inactivation was observed for pathogens without exposed lipid membranes including 99.99% inactivation of community-associated methicillin-resistant Staphylococcus aureus, 99.6% and >99% inactivation of Clostridium difficile spores and vegetative cells, respectively, and 50% inactivation of adenovirus type 5. To demonstrate that MPLEx yields biomaterial of sufficient quality for subsequent multi-omics analyses, we highlight select proteomics, metabolomics and lipidomics data from human epithelial lung cells infected with wild-type and mutant forms of influenza H7N9. We believe that MPLEx will facilitate systems biology studies of infectious samples by enabling simultaneous pathogen inactivation and multi

  2. Patients' Fear of Contracting the Blood-Borne Infections from Dentists

    Directory of Open Access Journals (Sweden)

    Fatemah Ayatollahi

    2007-01-01

    Full Text Available Introduction: There has been no recent assessment of public attitudes and opinions concerning risk of blood-borne pathogen transmission during health care. To assess public attitudes and opinions towards dentists infected with blood-borne viruses, this study was carried out.Materials and Methods: Six items in this cross-sectional survey were used to assess current attitudes and opinions about dentists infected with Human Immunodeficiency Virus (HIV, Hepatitis B and CViruses, and the risk of blood-borne virus transmission during health care in a sample of 500 cases, in Yazd. Data were analyzed by SPSS (version 13 and chi-square tests were used, when appropriate.Results: Of 500 respondents, 94% agreed that they want to know whether their dentist is infectedwith HIV, HBV or HCV; 93.8% agreed that disclosure of HIV, HBV or HCV infection in a provider should be mandatory. However, 15.8% did not believe that HIV-infected dentists were more likely to infect patients than those dentists infected with HBV or HCV. Opinions were divided on whether HIV-infected providers should be able to care for patients as long as they use good infection control:only 41.6% thought that infected providers should be allowed to provide patient care.Conclusion: These findings suggest that improved public education and risk communication on health care-associated blood-borne infections is needed.

  3. Prospects for a novel ultrashort pulsed laser technology for pathogen inactivation

    Directory of Open Access Journals (Sweden)

    Tsen Shaw-Wei D

    2012-07-01

    Full Text Available Abstract The threat of emerging pathogens and microbial drug resistance has spurred tremendous efforts to develop new and more effective antimicrobial strategies. Recently, a novel ultrashort pulsed (USP laser technology has been developed that enables efficient and chemical-free inactivation of a wide spectrum of viral and bacterial pathogens. Such a technology circumvents the need to introduce potentially toxic chemicals and could permit safe and environmentally friendly pathogen reduction, with a multitude of possible applications including the sterilization of pharmaceuticals and blood products, and the generation of attenuated or inactivated vaccines.

  4. Pathogens Inactivated by Low-Energy-Electron Irradiation Maintain Antigenic Properties and Induce Protective Immune Responses

    Science.gov (United States)

    Fertey, Jasmin; Bayer, Lea; Grunwald, Thomas; Pohl, Alexandra; Beckmann, Jana; Gotzmann, Gaby; Casado, Javier Portillo; Schönfelder, Jessy; Rögner, Frank-Holm; Wetzel, Christiane; Thoma, Martin; Bailer, Susanne M.; Hiller, Ekkehard; Rupp, Steffen; Ulbert, Sebastian

    2016-01-01

    Inactivated vaccines are commonly produced by incubating pathogens with chemicals such as formaldehyde or β-propiolactone. This is a time-consuming process, the inactivation efficiency displays high variability and extensive downstream procedures are often required. Moreover, application of chemicals alters the antigenic components of the viruses or bacteria, resulting in reduced antibody specificity and therefore stimulation of a less effective immune response. An alternative method for inactivation of pathogens is ionizing radiation. It acts very fast and predominantly damages nucleic acids, conserving most of the antigenic structures. However, currently used irradiation technologies (mostly gamma-rays and high energy electrons) require large and complex shielding constructions to protect the environment from radioactivity or X-rays generated during the process. This excludes them from direct integration into biological production facilities. Here, low-energy electron irradiation (LEEI) is presented as an alternative inactivation method for pathogens in liquid solutions. LEEI can be used in normal laboratories, including good manufacturing practice (GMP)- or high biosafety level (BSL)-environments, as only minor shielding is necessary. We show that LEEI efficiently inactivates different viruses (influenza A (H3N8), porcine reproductive and respiratory syndrome virus (PRRSV), equine herpesvirus 1 (EHV-1)) and bacteria (Escherichia coli) and maintains their antigenicity. Moreover, LEEI-inactivated influenza A viruses elicit protective immune responses in animals, as analyzed by virus neutralization assays and viral load determination upon challenge. These results have implications for novel ways of developing and manufacturing inactivated vaccines with improved efficacy. PMID:27886076

  5. An analysis of multimodal occupational exposure leading to blood borne infections among health care workers

    OpenAIRE

    N Lakshmi Priya; K Usha Krishnan; G Jayalakshmi; S Vasanthi

    2015-01-01

    Occupational exposure poses a significant risk of transmission of blood-borne pathogens to healthcare workers (HCWs). Adherence to standard precautions, awareness about post exposure prophylaxis is poor in developing countries. This retrospective study analyzes the self-reported cases of occupational exposure in a tertiary care hospital. During the study period, 105 HCWs sustained occupational exposure to blood and body fluids. Majority of the victims 36 (34.2%) were interns and the clinical ...

  6. Bacterial contamination of platelet concentrates: pathogen detection and inactivation methods

    Directory of Open Access Journals (Sweden)

    Dana Védy

    2009-04-01

    Full Text Available Whereas the reduction of transfusion related viral transmission has been a priority during the last decade, bacterial infection transmitted by transfusion still remains associated to a high morbidity and mortality, and constitutes the most frequent infectious risk of transfusion. This problem especially concerns platelet concentrates because of their favorable bacterial growth conditions. This review gives an overview of platelet transfusion-related bacterial contamination as well as on the different strategies to reduce this problem by using either bacterial detection or inactivation methods.

  7. Pathogen inactivation of Dengue virus in red blood cells using amustaline and glutathione.

    Science.gov (United States)

    Aubry, Maite; Laughhunn, Andrew; Santa Maria, Felicia; Lanteri, Marion C; Stassinopoulos, Adonis; Musso, Didier

    2017-12-01

    Dengue virus (DENV) is an arbovirus primarily transmitted through mosquito bite; however, DENV transfusion-transmitted infections (TTIs) have been reported and asymptomatic DENV RNA-positive blood donors have been identified in endemic countries. DENV is considered a high-risk pathogen for blood safety. One of the mitigation strategies to prevent arbovirus TTIs is pathogen inactivation. In this study we demonstrate that the amustaline and glutathione (S-303/GSH) treatment previously found effective against Zika virus in red blood cells (RBCs) is also effective in inactivating DENV. Red blood cells were spiked with high levels of DENV. Viral RNA loads and infectious titers were measured in the untreated control and before and after pathogen inactivation treatment of RBC samples. DENV infectivity was also assessed over five successive cell culture passages to detect any potential residual replicative virus. The mean ± SD DENV titer in RBCs before inactivation was 6.61 ± 0.19 log 50% tissue culture infectious dose (TCID 50 )/mL and the mean viral RNA load was 8.42 log genome equivalents/mL. No replicative DENV was detected either immediately after completion of treatment using S-303/GSH or after cell culture passages. Treatment using S-303/GSH inactivated high levels of DENV in RBCs to the limit of detection. In combination with previous studies showing the effective inactivation of DENV in plasma and platelets using the licensed amotosalen/UVA system, this study demonstrates that high levels of DENV can be inactivated in all blood components. © 2017 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  8. Inactivation of high concentration of pathogens in land-applied food ...

    African Journals Online (AJOL)

    In Mexico, as in other developing countries, the most important pollution and management problems of food-processing sludge are the high levels of pathogen microorganisms within the sludge and the lack of sites for its disposal. The aims of this study were to evaluate the effect of calcium oxide in the inactivation of ...

  9. Psychosocial Factors at Work and Blood-Borne Exposure among Nurses

    Directory of Open Access Journals (Sweden)

    R Mehrdad

    2014-01-01

    Full Text Available Background: Exposure to human blood and body fluids is a common risk for nurses. Many factors can affect the prevalence and incidence of this occupational hazard. Psychosocial factors at work may be a risk factor for the exposure. Objective: To assess needle stick, sharp injury and mucus exposure to blood-borne pathogens among nurses in Iran and to determine the association between these exposures and psychosocial factors at work. Methods: A cross-sectional study was conducted on nurses in a public hospital, Tehran, Iran. 364 nurses received and 339 completed and returned a self-reported questionnaire containing demographic data, history of exposure to blood-borne pathogens at work during previous year and the General Nordic questionnaire for psychological and social factors at work (QPS Nordic 34+ Questionnaire. Results: Of 339 participants, 197 (58.1% reported needle-stick injury, 186 (54.6% reported another type of sharp injury, and 112 (33% reported a mucous membrane exposure during the previous year. More than half of the participants who had history of exposure, had not reported it. Those with middle or high level of stress had higher crude and adjusted odds than those with lower stress for all kinds of exposure. Adjusted odds ratios for high stress group (ranging from 2.8 to 4.4 were statistically different from 1. Conclusion: There is a high prevalence of needle-stick and sharp injury and mucous membrane exposure to patients' blood or body fluids among studied nurses. There is a significant association between increasing psychosocial factors at work and exposure to blood-borne pathogens among this group of nurses.

  10. An analysis of multimodal occupational exposure leading to blood borne infections among health care workers.

    Science.gov (United States)

    Priya, N Lakshmi; Krishnan, K Usha; Jayalakshmi, G; Vasanthi, S

    2015-01-01

    Occupational exposure poses a significant risk of transmission of blood-borne pathogens to healthcare workers (HCWs). Adherence to standard precautions, awareness about post exposure prophylaxis is poor in developing countries. This retrospective study analyzes the self-reported cases of occupational exposure in a tertiary care hospital. During the study period, 105 HCWs sustained occupational exposure to blood and body fluids. Majority of the victims 36 (34.2%) were interns and the clinical practice that led to the occupational exposure was withdrawal of blood (45.7%). Good infection control practices and emphasis on appropriate disposal are needed to increase the occupational safety for HCWs.

  11. An analysis of multimodal occupational exposure leading to blood borne infections among health care workers

    Directory of Open Access Journals (Sweden)

    N Lakshmi Priya

    2015-01-01

    Full Text Available Occupational exposure poses a significant risk of transmission of blood-borne pathogens to healthcare workers (HCWs. Adherence to standard precautions, awareness about post exposure prophylaxis is poor in developing countries. This retrospective study analyzes the self-reported cases of occupational exposure in a tertiary care hospital. During the study period, 105 HCWs sustained occupational exposure to blood and body fluids. Majority of the victims 36 (34.2% were interns and the clinical practice that led to the occupational exposure was withdrawal of blood (45.7%. Good infection control practices and emphasis on appropriate disposal are needed to increase the occupational safety for HCWs.

  12. Gamma irradiation inactivates honey bee fungal, microsporidian, and viral pathogens and parasites.

    Science.gov (United States)

    Simone-Finstrom, Michael; Aronstein, Kate; Goblirsch, Michael; Rinkevich, Frank; de Guzman, Lilia

    2018-03-01

    Managed honey bee (Apis mellifera) populations are currently facing unsustainable losses due to a variety of factors. Colonies are challenged with brood pathogens, such as the fungal agent of chalkbrood disease, the microsporidian gut parasite Nosema spp., and several viruses. These pathogens may be transmitted horizontally from worker to worker, vertically from queen to egg and via vectors like the parasitic mite, Varroa destructor. Despite the fact that these pathogens are widespread and often harbored in wax comb that is reused from year to year and transferred across beekeeping operations, few, if any, universal treatments exist for their control. In order to mitigate some of these biological threats to honey bees and to allow for more sustainable reuse of equipment, investigations into techniques for the sterilization of hive equipment and comb are of particular significance. Here, we investigated the potential of gamma irradiation for inactivation of the fungal pathogen Ascosphaera apis, the microsporidian Nosema ceranae and three honey bee viruses (Deformed wing virus [DWV], Black queen cell virus [BQCV], and Chronic bee paralysis virus [CBPV]), focusing on the infectivity of these pathogens post-irradiation. Results indicate that gamma irradiation can effectively inactivate A. apis, N. ceranae, and DWV. Partial inactivation was noted for BQCV and CBPV, but this did not reduce effects on mortality at the tested, relatively high doses. These findings highlight the importance of studying infection rate and symptom development post-treatment and not simply rate or quantity detected. These findings suggest that gamma irradiation may function as a broad treatment to help mitigate colony losses and the spread of pathogens through the exchange of comb across colonies, but raises the question why some viruses appear to be unaffected. These results provide the basis for subsequent studies on benefits of irradiation of used comb for colony health and productivity

  13. Development of a Nordic system for measuring the inactivation of pathogens during composting

    DEFF Research Database (Denmark)

    Christensen, Kasper Kjellberg; Møller, Kaare; Hockenhull, John

    The report presents the results of a study initiated to prepare a full-scale investigation for evaluating the inactivation of pathogens during composting of biodegradable waste by means of a direct evaluation. On the basis of the presented study it is recommended to include the direct procees...... evaluation in the Nordic full-scale investigation for evaluating the sanitary aspects of composting biodegradable waste...

  14. Treatment alternatives of slaughterhouse wastes, and their effect on the inactivation of different pathogens: a review.

    Science.gov (United States)

    Franke-Whittle, Ingrid H; Insam, Heribert

    2013-05-01

    Slaughterhouse wastes are a potential reservoir of bacterial, viral, prion and parasitic pathogens, capable of infecting both animals and humans. A quick, cost effective and safe disposal method is thus essential in order to reduce the risk of disease following animal slaughter. Different methods for the disposal of such wastes exist, including composting, anaerobic digestion (AD), alkaline hydrolysis (AH), rendering, incineration and burning. Composting is a disposal method that allows a recycling of the slaughterhouse waste nutrients back into the earth. The high fat and protein content of slaughterhouse wastes mean however, that such wastes are an excellent substrate for AD processes, resulting in both the disposal of wastes, a recycling of nutrients (soil amendment with sludge), and in methane production. Concerns exist as to whether AD and composting processes can inactivate pathogens. In contrast, AH is capable of the inactivation of almost all known microorganisms. This review was conducted in order to compare three different methods of slaughterhouse waste disposal, as regards to their ability to inactivate various microbial pathogens. The intention was to investigate whether AD could be used for waste disposal (either alone, or in combination with another process) such that both energy can be obtained and potentially hazardous materials be disposed of.

  15. Inactivation of food-borne pathogens by combined high hydrostatic pressure and irradiation- a model study

    International Nuclear Information System (INIS)

    Kamat, Anu; Thomas, Paul; Kesavan, P.C.; Fotedar, R.

    1997-01-01

    Application of radiation or high pressure as a food processing method is comparatively recent development in food industry. To investigate the response to hydrostatic pressure, cells of pathogens at logarithmic phase were exposed to 200 MPa for various time intervals in saline as model system. The cells of Salmonella were observed to be most sensitive whereas Listeria monocytogenes were most resistant as revealed by 7 and 2 log cycle inactivation respectively in 10 min. The cells of Bacillus cereus and Yersinia enterocolitica showed 3 long cycles reduction by the same treatment. Bacterial spores because of their resistant nature, are inactivated only at high radiation doses, which are technologically unfeasible. Studies carried out to examine the effectiveness of combination of pressure and radiation clearly suggested that combination treatment given in either sequence reduces the bacterial spore load more effectively than the individual treatment per se. (author)

  16. Effective inactivation of a wide range of viruses by pasteurization.

    Science.gov (United States)

    Gröner, Albrecht; Broumis, Connie; Fang, Randel; Nowak, Thomas; Popp, Birgit; Schäfer, Wolfram; Roth, Nathan J

    2018-01-01

    Careful selection and testing of plasma reduces the risk of blood-borne viruses in the starting material for plasma-derived products. Furthermore, effective measures such as pasteurization at 60°C for 10 hours have been implemented in the manufacturing process of therapeutic plasma proteins such as human albumin, coagulation factors, immunoglobulins, and enzyme inhibitors to inactivate blood-borne viruses of concern. A comprehensive compilation of the virus reduction capacity of pasteurization is presented including the effect of stabilizers used to protect the therapeutic protein from modifications during heat treatment. The virus inactivation kinetics of pasteurization for a broad range of viruses were evaluated in the relevant intermediates from more than 15 different plasma manufacturing processes. Studies were carried out under the routine manufacturing target variables, such as temperature and product-specific stabilizer composition. Additional studies were also performed under robustness conditions, that is, outside production specifications. The data demonstrate that pasteurization inactivates a wide range of enveloped and nonenveloped viruses of diverse physicochemical characteristics. After a maximum of 6 hours' incubation, no residual infectivity could be detected for the majority of enveloped viruses. Effective inactivation of a range of nonenveloped viruses, with the exception of nonhuman parvoviruses, was documented. Pasteurization is a very robust and reliable virus inactivation method with a broad effectiveness against known blood-borne pathogens and emerging or potentially emerging viruses. Pasteurization has proven itself to be a highly effective step, in combination with other complementary safety measures, toward assuring the virus safety of final product. © 2017 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  17. PEF and UV combined system for pathogen microorganisms inactivation in liquid food products

    Energy Technology Data Exchange (ETDEWEB)

    Cramariuc, R [Competence Center in Electrostatics and Electrotechnologies, Bucharest (Romania); Popa, M; Mitelut, A; Geicu, M [University of Agronomic Science and Veterinary Medicine, Bucharest (Romania); Tudorache, A; Brinduse, E; Kontek, A; Fotescu, L [Research and Development Institute in Viticulture and Vinification Valea Calugareasca (Romania); Cramariuc, B [IT Center for Science and Technology, Bucharest (Romania); Nisiparu, L, E-mail: raducramariuc@yahoo.com [Carol Davila University of Medicine and Pharmacy, Bucharest (Romania)

    2011-06-23

    Pulsed electrical field (PEF) treatment is a non-thermal food preservation technology based on the use of the electrical field in impulses applied in order to inactivate and control pathogen microorganisms in foods. This technology is highly appreciated for its ability to prolong the shelf life of the treated product without the use of heat and also for its ability to preserve the product's sensory qualities and nutritional value as well as for the microbiological control of the treated products. This paper presents the PEF and UV treatment methods, or a combination between the two, for microbe inactivation in liquid products. The experiments were carried out using yeasts, lactic bacteria and acetic bacteria in the following systems: stand-alone treatments (PEF or UV) or in combination (UV+PEF or PEF+UV). The results of these experiments showed that one can obtain total inactivation of microorganisms using the combined UV+PEF system, thus leading to the possibility of increasing liquid food products quality as compared to the quality obtained using thermal pasteurization.

  18. PEF and UV combined system for pathogen microorganisms inactivation in liquid food products

    Science.gov (United States)

    Cramariuc, R.; Popa, M.; Tudorache, A.; Brînduşe, E.; Kontek, A.; Mitelut, A.; Fotescu, L.; Cramariuc, B.; Geicu, M.; Nisiparu, L.

    2011-06-01

    Pulsed electrical field (PEF) treatment is a non-thermal food preservation technology based on the use of the electrical field in impulses applied in order to inactivate and control pathogen microorganisms in foods. This technology is highly appreciated for its ability to prolong the shelf life of the treated product without the use of heat and also for its ability to preserve the product's sensory qualities and nutritional value as well as for the microbiological control of the treated products. This paper presents the PEF and UV treatment methods, or a combination between the two, for microbe inactivation in liquid products. The experiments were carried out using yeasts, lactic bacteria and acetic bacteria in the following systems: stand-alone treatments (PEF or UV) or in combination (UV+PEF or PEF+UV). The results of these experiments showed that one can obtain total inactivation of microorganisms using the combined UV+PEF system, thus leading to the possibility of increasing liquid food products quality as compared to the quality obtained using thermal pasteurization.

  19. PEF and UV combined system for pathogen microorganisms inactivation in liquid food products

    International Nuclear Information System (INIS)

    Cramariuc, R; Popa, M; Mitelut, A; Geicu, M; Tudorache, A; Brinduse, E; Kontek, A; Fotescu, L; Cramariuc, B; Nisiparu, L

    2011-01-01

    Pulsed electrical field (PEF) treatment is a non-thermal food preservation technology based on the use of the electrical field in impulses applied in order to inactivate and control pathogen microorganisms in foods. This technology is highly appreciated for its ability to prolong the shelf life of the treated product without the use of heat and also for its ability to preserve the product's sensory qualities and nutritional value as well as for the microbiological control of the treated products. This paper presents the PEF and UV treatment methods, or a combination between the two, for microbe inactivation in liquid products. The experiments were carried out using yeasts, lactic bacteria and acetic bacteria in the following systems: stand-alone treatments (PEF or UV) or in combination (UV+PEF or PEF+UV). The results of these experiments showed that one can obtain total inactivation of microorganisms using the combined UV+PEF system, thus leading to the possibility of increasing liquid food products quality as compared to the quality obtained using thermal pasteurization.

  20. Mild processing applied to the inactivation of the main foodborne bacterial pathogens

    DEFF Research Database (Denmark)

    Barba Orellana, Francisco Jose; Koubaa, Mohamed; do Prado-Silva, Leonardo

    2017-01-01

    shelf-lives, pasteurization and commercial sterilization may result in numerous nutritional and sensory changes in foods. To address these disadvantages, mild processing methods (i.e., processing technologies for food preservation that apply mild temperature; ... contaminants have been developed. Scope and approach This review emphasizes the main applications of mild technologies aiming to the inactivation of the four main pathogenic bacteria of relevance for food safety as well as their mechanisms of action. Key findings and conclusions Mild processing technologies...... such as high pressure processing, ultrasounds, pulsed electric fields, UV-light, and atmospheric cold plasma may serve, in some conditions, as useful alternatives to commercial sterilization and pasteurization aiming to destroy foodborne pathogens. Each of these mild technologies has a specific mode...

  1. Immunogenicity of commercial, formaldehyde and binary ethylenimine inactivated Newcastle disease virus vaccines in specific pathogen free chickens

    Directory of Open Access Journals (Sweden)

    Razmaraii, N.

    2012-06-01

    Full Text Available Newcastle disease (ND is one of the most important diseases that affect birds; the epizootic nature of the disease has caused severe economic losses in the poultry industry worldwide. In this experiment ND virus (NDV was inactivated by two different chemicals binary ethylenimine (BEI and formaldehyde. Formaldehyde was used at 0.1%, while BEI was used at concentrations of 1 to 4 mM. NDV inactivation with BEI was done in various incubation temperatures and periods and the best result (30 °C, 4 mM BEI and 21 hrs treatment used as an experimental vaccine. Prepared inactivated NDV vaccines and a commercial vaccine were tested for their efficiency in generating humoral immune response in different groups of specific pathogen free (SPF chicks. Test groups received 0.2 ml formaldehyde inactivated NDV (NDVF, BEI inactivated NDV (NDVEI and Razi institute produced NDV vaccine (NDVR subcutaneously respectively. HI Log 2 total mean titer of NDVEI group (8.42 ± 0.12 were significantly higher than NDVF (7.64 ± 0.16 and NDVR (7.86 ± 0.11 groups (p<0.05. BEI-inactivated vaccine gave higher antibody titers than formaldehyde-inactivated vaccine and preserves both structural integrity and antigenicity of the virus. Thus, it might be possible to use these compounds as an inactivator agent for commercial NDV inactivated vaccines in future.

  2. Application of gamma irradiation for inactivation of three pathogenic bacteria inoculated into meatballs

    Science.gov (United States)

    Gumus, Tuncay; Şukru Demirci, A.; Murat Velioglu, H.; Velioglu, Serap D.; Yilmaz, Ismail; Sagdic, Osman

    2008-09-01

    In this research, the effect of gamma irradiation on the inactivation of Escherichia coli O157:H7 (ATCC 33150), Staphylococcus aureus (ATCC 2392) and Salmonella typhimurium (NRRL 4463) inoculated into Tekirdag meatballs was investigated. The meatball samples were inoculated with pathogens and irradiated at the absorbed doses of 1, 2.2, 3.2, 4.5 and 5.2 kGy. E. coli O157:H7 count in 1 kGy irradiated meatballs stored in the refrigerator for 7 days was detected to be 4 log cfu/g lower than the count in nonirradiated samples ( pmeatballs. However, none of the test organisms were detected in the samples after irradiation with 4.5 kGy doses.

  3. Pathogen inactivation in liquid dairy manure during anaerobic and aerobic digestions

    Science.gov (United States)

    Biswas, S.; Pandey, P.; Castillo, A. R.; Vaddella, V. K.

    2014-12-01

    Controlling manure-borne pathogens such as E. coli O157:H7, Salmonella spp. and Listeria monocytogenes are crucial for protecting surface and ground water as well as mitigating risks to human health. In California dairy farms, flushing of dairy manure (mainly animal feces and urine) from freestall barns and subsequent liquid-solid manure separation is a common practice for handling animal waste. The liquid manure fraction is generally pumped into the settling ponds and it goes into aerobic and/or anaerobic lagoons for extended period of time. Considering the importance of controlling pathogens in animal waste, the objective of the study was to understand the effects of anaerobic and aerobic digestions on the survival of three human pathogens in animal waste. The pathogen inactivation was assessed at four temperatures (30, 35, 42, and 50 °C), and the relationships between temperature and pathogen decay were estimated. Results showed a steady decrease of E. coli levels in aerobic and anaerobic digestion processes over the time; however, the decay rates varied with pathogens. The effect of temperature on Salmonella spp. and Listeria monocytogenes survival was different than the E. coli survival. In thermophilic temperatures (42 and 50 °C), decay rate was considerable greater compared to the mesophilic temperatures (30 and 35°C). The E. coli log reductions at 50 °C were 2.1 in both aerobic and anaerobic digestions after 13 days of incubation. The Salmonella spp. log reductions at 50 °C were 5.5 in aerobic digestion, and 5.9 in anaerobic digestion. The Listeria monocytogenes log reductions at 50 °C were 5.0 in aerobic digestion, and 5.6 in anaerobic digestion. The log reduction of E. coli, Salmonella spp., and Listeria monocytogens at 30 °C in aerobic environment were 0.1, 4.7, and 5.6, respectively. In anaerobic environment, the corresponding reductions were 0.4, 4.3, and 5.6, respectively. We anticipate that the outcomes of the study will help improving the

  4. Inactivated Recombinant Rabies Viruses Displaying Canine Distemper Virus Glycoproteins Induce Protective Immunity against Both Pathogens.

    Science.gov (United States)

    da Fontoura Budaszewski, Renata; Hudacek, Andrew; Sawatsky, Bevan; Krämer, Beate; Yin, Xiangping; Schnell, Matthias J; von Messling, Veronika

    2017-04-15

    The development of multivalent vaccines is an attractive methodology for the simultaneous prevention of several infectious diseases in vulnerable populations. Both canine distemper virus (CDV) and rabies virus (RABV) cause lethal disease in wild and domestic carnivores. While RABV vaccines are inactivated, the live-attenuated CDV vaccines retain residual virulence for highly susceptible wildlife species. In this study, we developed recombinant bivalent vaccine candidates based on recombinant vaccine strain rabies virus particles, which concurrently display the protective CDV and RABV glycoprotein antigens. The recombinant viruses replicated to near-wild-type titers, and the heterologous glycoproteins were efficiently expressed and incorporated in the viral particles. Immunization of ferrets with beta-propiolactone-inactivated recombinant virus particles elicited protective RABV antibody titers, and animals immunized with a combination of CDV attachment protein- and fusion protein-expressing recombinant viruses were protected from lethal CDV challenge. However, animals that were immunized with only a RABV expressing the attachment protein of CDV vaccine strain Onderstepoort succumbed to infection with a more recent wild-type strain, indicating that immune responses to the more conserved fusion protein contribute to protection against heterologous CDV strains. IMPORTANCE Rabies virus and canine distemper virus (CDV) cause high mortality rates and death in many carnivores. While rabies vaccines are inactivated and thus have an excellent safety profile and high stability, live-attenuated CDV vaccines can retain residual virulence in highly susceptible species. Here we generated recombinant inactivated rabies viruses that carry one of the CDV glycoproteins on their surface. Ferrets immunized twice with a mix of recombinant rabies viruses carrying the CDV fusion and attachment glycoproteins were protected from lethal CDV challenge, whereas all animals that received

  5. Detection, fate and inactivation of pathogenic norovirus employing settlement and UV treatment in wastewater treatment facilities

    International Nuclear Information System (INIS)

    Barrett, M.; Fitzhenry, K.; O'Flaherty, V.; Dore, W.; Keaveney, S.; Cormican, M.; Rowan, N.; Clifford, E.

    2016-01-01

    It is accepted that discharged wastewaters can be a significant source of pathogenic viruses in receiving water bodies contributing to pollution and may in turn enter the human food chain and pose a risk to human health, thus norovirus (NoV) is often a predominant cause of gastroenteritis globally. Working with NoV poses particular challenges as it cannot be readily identified and detection by molecular methods does not assess infectivity. It has been proposed that the infectivity of NoV may be modelled through the use of an alternative virus; F-specific RNA (FRNA) bacteriophages; GA genotype and other FRNA bacteriophages have been used as a surrogate in studies of NoV inactivation. This study investigated the efficiency of novel pulsed ultraviolet irradiation and low pressure ultraviolet irradiation as a potential pathogen inactivation system for NoV and FRNA bacteriophage (GA) in secondary treated wastewaters. The role of UV dose and the impact of suspended solids concentration on removal efficiency were also examined. The study also investigated the role of settlement processes in wastewater treatment plants in removing NoV. While NoV inactivation could not be determined it was found that at a maximum UV dose of 6.9 J/cm"2 (6900 mJ/cm"2) an average 2.4 log removal of FRNA bacteriophage (GA) was observed; indicating the potential need for high UV doses to remove NoV if FRNA bacteriophage prove a suitable indicator for NoV. The study found that increasing concentrations of suspended solids impacted on PUV efficiency however, it appears the extent of the impact may be site specific. Furthermore, the study found that settlement processes can play a significant role in the removal of FRNA bacteriophage, thus potentially NoV. - Highlights: • Effectiveness of low pressure UV and novel high-intensity pulsed UV disinfection in NoVs removal. • Reduction of FRNA bacteriophage was seen in clarified wastewater after settling. • Adsorption of viral particles to solids

  6. Detection, fate and inactivation of pathogenic norovirus employing settlement and UV treatment in wastewater treatment facilities

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, M. [Microbial Ecology Laboratory, Microbiology, School of Natural sciences, National University of Ireland Galway (Ireland); Ryan Institute, National University of Ireland Galway (Ireland); College of Engineering and Informatics, National University of Ireland Galway (Ireland); Fitzhenry, K. [Ryan Institute, National University of Ireland Galway (Ireland); College of Engineering and Informatics, National University of Ireland Galway (Ireland); O' Flaherty, V. [Microbial Ecology Laboratory, Microbiology, School of Natural sciences, National University of Ireland Galway (Ireland); Ryan Institute, National University of Ireland Galway (Ireland); Dore, W.; Keaveney, S. [Marine Institute, Galway (Ireland); Cormican, M. [Ryan Institute, National University of Ireland Galway (Ireland); Centre for Health from Environment, Ryan Institute, National University of Ireland Galway (Ireland); Rowan, N. [Bioscience Research Institute, Athlone Institute of Technology (Ireland); Clifford, E., E-mail: eoghan.clifford@nuigalway.ie [Ryan Institute, National University of Ireland Galway (Ireland); College of Engineering and Informatics, National University of Ireland Galway (Ireland)

    2016-10-15

    It is accepted that discharged wastewaters can be a significant source of pathogenic viruses in receiving water bodies contributing to pollution and may in turn enter the human food chain and pose a risk to human health, thus norovirus (NoV) is often a predominant cause of gastroenteritis globally. Working with NoV poses particular challenges as it cannot be readily identified and detection by molecular methods does not assess infectivity. It has been proposed that the infectivity of NoV may be modelled through the use of an alternative virus; F-specific RNA (FRNA) bacteriophages; GA genotype and other FRNA bacteriophages have been used as a surrogate in studies of NoV inactivation. This study investigated the efficiency of novel pulsed ultraviolet irradiation and low pressure ultraviolet irradiation as a potential pathogen inactivation system for NoV and FRNA bacteriophage (GA) in secondary treated wastewaters. The role of UV dose and the impact of suspended solids concentration on removal efficiency were also examined. The study also investigated the role of settlement processes in wastewater treatment plants in removing NoV. While NoV inactivation could not be determined it was found that at a maximum UV dose of 6.9 J/cm{sup 2} (6900 mJ/cm{sup 2}) an average 2.4 log removal of FRNA bacteriophage (GA) was observed; indicating the potential need for high UV doses to remove NoV if FRNA bacteriophage prove a suitable indicator for NoV. The study found that increasing concentrations of suspended solids impacted on PUV efficiency however, it appears the extent of the impact may be site specific. Furthermore, the study found that settlement processes can play a significant role in the removal of FRNA bacteriophage, thus potentially NoV. - Highlights: • Effectiveness of low pressure UV and novel high-intensity pulsed UV disinfection in NoVs removal. • Reduction of FRNA bacteriophage was seen in clarified wastewater after settling. • Adsorption of viral particles

  7. Integrated oxide graphene based device for laser inactivation of pathogenic microorganisms

    Science.gov (United States)

    Grishkanich, Alexsandr; Ruzankina, Julia; Afanasyev, Mikhail; Paklinov, Nikita; Hafizov, Nail

    2018-02-01

    We develop device for virus disinfection of pathogenic microorganisms. Viral decontamination can be carried out due to hard ultraviolet irradiation and singlet oxygen destroying the genetic material of a virus capsid. UV rays can destroy DNA, leading to the formation of dimers of nucleic acids. This practically does not occur in tissues, tk. UV rays penetrate badly through them, however, the viral particles are small and UV can destroy their genetic material, RNA / DNA and the virus can not replicate. It is with the construction of the ultraviolet laser water disinfection system (UFLOV) based on the continuous and periodic pulsed ultraviolet laser sources (pump) binds to solve sterility and depyrogenation of water. It has been established that small doses of UV irradiation stimulate reproduction, and large doses cause the death of pathogenic microorganisms. The effect of a dose of ultraviolet is the result of photochemical action on the substance of a living bacterial cell or virion. Also complex photodynamic laser inactivation on graphene oxide is realized.

  8. Pathogen reduction by ultraviolet C light effectively inactivates human white blood cells in platelet products.

    Science.gov (United States)

    Pohler, Petra; Müller, Meike; Winkler, Carla; Schaudien, Dirk; Sewald, Katherina; Müller, Thomas H; Seltsam, Axel

    2015-02-01

    Residual white blood cells (WBCs) in cellular blood components induce a variety of adverse immune events, including nonhemolytic febrile transfusion reactions, alloimmunization to HLA antigens, and transfusion-associated graft-versus-host disease (TA-GVHD). Pathogen reduction (PR) methods such as the ultraviolet C (UVC) light-based THERAFLEX UV-Platelets system were developed to reduce the risk of transfusion-transmitted infection. As UVC light targets nucleic acids, it interferes with the replication of both pathogens and WBCs. This preclinical study aimed to evaluate the ability of UVC light to inactivate contaminating WBCs in platelet concentrates (PCs). The in vitro and in vivo function of WBCs from UVC-treated PCs was compared to that of WBCs from gamma-irradiated and untreated PCs by measuring cell viability, proliferation, cytokine secretion, antigen presentation in vitro, and xenogeneic GVHD responses in a humanized mouse model. UVC light was at least as effective as gamma irradiation in preventing GVHD in the mouse model. It was more effective in suppressing T-cell proliferation (>5-log reduction in the limiting dilution assay), cytokine secretion, and antigen presentation than gamma irradiation. The THERAFLEX UV-Platelets (MacoPharma) PR system can substitute gamma irradiation for TA-GVHD prophylaxis in platelet (PLT) transfusion. Moreover, UVC treatment achieves suppression of antigen presentation and inhibition of cytokine accumulation during storage of PCs, which has potential benefits for transfusion recipients. © 2014 AABB.

  9. Reducing the financial impact of pathogen inactivation technology for platelet components: our experience.

    Science.gov (United States)

    Girona-Llobera, Enrique; Jimenez-Marco, Teresa; Galmes-Trueba, Ana; Muncunill, Josep; Serret, Carmen; Serra, Neus; Sedeño, Matilde

    2014-01-01

    Pathogen inactivation (PI) technology for blood components enhances blood safety by inactivating viruses, bacteria, parasites, and white blood cells. Additionally, PI for platelet (PLT) components has the potential to extend PLT storage time from 5 to 7 days. A retrospective analysis was conducted into the percentage of outdated PLT components during the 3 years before and after the adoption of PLT PI technology in our institution. The PLT transfusion dose for both pre-PI and post-PI periods was similar. A retrospective analysis to study clinical safety and component utilization was also performed in the Balearic Islands University Hospital. As a result of PI implementation in our institution, the PLT production cost increased by 85.5%. However, due to the extension of PLT storage time, the percentage of outdated PLT units substantially decreased (-83.9%) and, consequently, the cost associated with outdated units (-69.8%). This decrease represented a 13.7% reduction of the initial cost increase which, together with the saving in blood transportation (0.1%), led to a saving of 13.8% over the initial cost. Therefore, the initial 85.5% increase in the cost of PLT production was markedly reduced to 71.7%. The mean number of PLT concentrates per patient was similar during both periods. The extension of PLT storage time can substantially contribute to reducing the financial impact of PI by decreasing the percentage of outdated PLTs while improving blood safety. Since the adoption of PI, there have been no documented cases of PLT transfusion-related sepsis in our region. © 2013 American Association of Blood Banks.

  10. Pathogen Inactivating Properties and Increased Sensitivity in Molecular Diagnostics by PAXgene, a Novel Non-Crosslinking Tissue Fixative.

    Directory of Open Access Journals (Sweden)

    Martina Loibner

    Full Text Available Requirements on tissue fixatives are getting more demanding as molecular analysis becomes increasingly relevant for routine diagnostics. Buffered formaldehyde in pathology laboratories for tissue fixation is known to cause chemical modifications of biomolecules which affect molecular testing. A novel non-crosslinking tissue preservation technology, PAXgene Tissue (PAXgene, was developed to preserve the integrity of nucleic acids in a comparable way to cryopreservation and also to preserve morphological features comparable to those of formalin fixed samples.Because of the excellent preservation of biomolecules by PAXgene we investigated its pathogen inactivation ability and biosafety in comparison to formalin by in-vitro testing of bacteria, human relevant fungi and human cytomegalovirus (CMV. Guidelines for testing disinfectants served as reference for inactivation assays. Furthermore, we tested the properties of PAXgene for detection of pathogens by PCR based assays.All microorganisms tested were similarly inactivated by PAXgene and formalin except Clostridium sporogenes, which remained viable in seven out of ten assays after PAXgene treatment and in three out of ten assays after formalin fixation. The findings suggest that similar biosafety measures can be applied for PAXgene and formalin fixed samples. Detection of pathogens in PCR-based diagnostics using two CMV assays resulted in a reduction of four to ten quantification cycles of PAXgene treated samples which is a remarkable increase of sensitivity.PAXgene fixation might be superior to formalin fixation when molecular diagnostics and highly sensitive detection of pathogens is required in parallel to morphology assessment.

  11. Pathogen Inactivating Properties and Increased Sensitivity in Molecular Diagnostics by PAXgene, a Novel Non-Crosslinking Tissue Fixative.

    Science.gov (United States)

    Loibner, Martina; Buzina, Walter; Viertler, Christian; Groelz, Daniel; Hausleitner, Anja; Siaulyte, Gintare; Kufferath, Iris; Kölli, Bettina; Zatloukal, Kurt

    2016-01-01

    Requirements on tissue fixatives are getting more demanding as molecular analysis becomes increasingly relevant for routine diagnostics. Buffered formaldehyde in pathology laboratories for tissue fixation is known to cause chemical modifications of biomolecules which affect molecular testing. A novel non-crosslinking tissue preservation technology, PAXgene Tissue (PAXgene), was developed to preserve the integrity of nucleic acids in a comparable way to cryopreservation and also to preserve morphological features comparable to those of formalin fixed samples. Because of the excellent preservation of biomolecules by PAXgene we investigated its pathogen inactivation ability and biosafety in comparison to formalin by in-vitro testing of bacteria, human relevant fungi and human cytomegalovirus (CMV). Guidelines for testing disinfectants served as reference for inactivation assays. Furthermore, we tested the properties of PAXgene for detection of pathogens by PCR based assays. All microorganisms tested were similarly inactivated by PAXgene and formalin except Clostridium sporogenes, which remained viable in seven out of ten assays after PAXgene treatment and in three out of ten assays after formalin fixation. The findings suggest that similar biosafety measures can be applied for PAXgene and formalin fixed samples. Detection of pathogens in PCR-based diagnostics using two CMV assays resulted in a reduction of four to ten quantification cycles of PAXgene treated samples which is a remarkable increase of sensitivity. PAXgene fixation might be superior to formalin fixation when molecular diagnostics and highly sensitive detection of pathogens is required in parallel to morphology assessment.

  12. Application of gamma irradiation for inactivation of three pathogenic bacteria inoculated into meatballs

    Energy Technology Data Exchange (ETDEWEB)

    Gumus, Tuncay [Department of Food Engineering, Faculty of Agriculture, Namik Kemal University, 59030 Tekirdag (Turkey); Sukru Demirci, A; Murat Velioglu, H; Velioglu, Serap D; Yilmaz, Ismail [Department of Food Engineering, Faculty of Agriculture, Namik Kemal University, 59030 Tekirdag (Turkey); Sagdic, Osman [Department of Food Engineering, Faculty of Engineering, Erciyes University, Kayseri (Turkey)

    2008-09-15

    In this research, the effect of gamma irradiation on the inactivation of Escherichia coli O157:H7 (ATCC 33150), Staphylococcus aureus (ATCC 2392) and Salmonella typhimurium (NRRL 4463) inoculated into Tekirdag meatballs was investigated. The meatball samples were inoculated with pathogens and irradiated at the absorbed doses of 1, 2.2, 3.2, 4.5 and 5.2 kGy. E. coli O157:H7 count in 1 kGy irradiated meatballs stored in the refrigerator for 7 days was detected to be 4 log cfu/g lower than the count in nonirradiated samples (p<0.05). S. aureus counts were decreased to 4 log cfu/g after being exposed to irradiation at a dose of 1 kGy. Although it was ineffective on elimination of S. typhimurium, irradiation at a dose of 3.2 kGy reduced E. coli O157:H7 and S. aureus counts under detectable values in the meatballs. However, none of the test organisms were detected in the samples after irradiation with 4.5 kGy doses.

  13. Application of gamma irradiation for inactivation of three pathogenic bacteria inoculated into meatballs

    International Nuclear Information System (INIS)

    Gumus, Tuncay; Sukru Demirci, A.; Murat Velioglu, H.; Velioglu, Serap D.; Yilmaz, Ismail; Sagdic, Osman

    2008-01-01

    In this research, the effect of gamma irradiation on the inactivation of Escherichia coli O157:H7 (ATCC 33150), Staphylococcus aureus (ATCC 2392) and Salmonella typhimurium (NRRL 4463) inoculated into Tekirdag meatballs was investigated. The meatball samples were inoculated with pathogens and irradiated at the absorbed doses of 1, 2.2, 3.2, 4.5 and 5.2 kGy. E. coli O157:H7 count in 1 kGy irradiated meatballs stored in the refrigerator for 7 days was detected to be 4 log cfu/g lower than the count in nonirradiated samples (p<0.05). S. aureus counts were decreased to 4 log cfu/g after being exposed to irradiation at a dose of 1 kGy. Although it was ineffective on elimination of S. typhimurium, irradiation at a dose of 3.2 kGy reduced E. coli O157:H7 and S. aureus counts under detectable values in the meatballs. However, none of the test organisms were detected in the samples after irradiation with 4.5 kGy doses

  14. Culture of human cell lines by a pathogen-inactivated human platelet lysate.

    Science.gov (United States)

    Fazzina, R; Iudicone, P; Mariotti, A; Fioravanti, D; Procoli, A; Cicchetti, E; Scambia, G; Bonanno, G; Pierelli, L

    2016-08-01

    Alternatives to the use of fetal bovine serum (FBS) have been investigated to ensure xeno-free growth condition. In this study we evaluated the efficacy of human platelet lysate (PL) as a substitute of FBS for the in vitro culture of some human cell lines. PL was obtained by pools of pathogen inactivated human donor platelet (PLT) concentrates. Human leukemia cell lines (KG-1, K562, JURKAT, HL-60) and epithelial tumor cell lines (HeLa and MCF-7) were cultured with either FBS or PL. Changes in cell proliferation, viability, morphology, surface markers and cell cycle were evaluated for each cell line. Functional characteristics were analysed by drug sensitivity test and cytotoxicity assay. Our results demonstrated that PL can support growth and expansion of all cell lines, although the cells cultured in presence of PL experienced a less massive proliferation compared to those grown with FBS. We found a comparable percentage of viable specific marker-expressing cells in both conditions, confirming lineage fidelity in all cultures. Functionality assays showed that cells in both FBS- and PL-supported cultures maintained their normal responsiveness to adriamycin and NK cell-mediated lysis. Our findings indicate that PL is a feasible serum substitute for supporting growth and propagation of haematopoietic and epithelial cell lines with many advantages from a perspective of process standardization, ethicality and product safety.

  15. The absorbed dose to blood from blood-borne activity

    International Nuclear Information System (INIS)

    Hänscheid, H; Fernández, M; Lassmann, M

    2015-01-01

    The radiation absorbed dose to blood and organs from activity in the blood is relevant for nuclear medicine dosimetry and for research in biodosimetry. The present study provides coefficients for the average absorbed dose rates to the blood from blood-borne activity for radionuclides frequently used in targeted radiotherapy and in PET diagnostics. The results were deduced from published data for vessel radius-dependent dose rate coefficients and reasonable assumptions on the blood-volume distribution as a function of the vessel radius. Different parts of the circulatory system were analyzed separately. Vessel size information for heart chambers, aorta, vena cava, pulmonary artery, and capillaries was taken from published results of morphometric measurements. The remaining blood not contained in the mentioned vessels was assumed to reside in fractal-like vascular trees, the smallest branches of which are the arterioles or venules. The applied vessel size distribution is consistent with recommendations of the ICRP on the blood-volume distribution in the human. The resulting average absorbed dose rates to the blood per nuclear disintegration per milliliter (ml) of blood are (in 10 −11  Gy·s −1 ·Bq −1 ·ml) Y-90: 5.58, I-131: 2.49, Lu-177: 1.72, Sm-153: 2.97, Tc-99m: 0.366, C-11: 4.56, F-18: 3.61, Ga-68: 5.94, I-124: 2.55. Photon radiation contributes 1.1–1.2·10 −11  Gy·s −1 ·Bq −1 ·ml to the total dose rate for positron emitters but significantly less for the other nuclides. Blood self-absorption of the energy emitted by ß-particles in the whole blood ranges from 37% for Y-90 to 80% for Tc-99m. The correspondent values in vascular trees, which are important for the absorbed dose to organs, range from 30% for Y-90 to 82% for Tc-99m. (paper)

  16. Effects of use of riboflavin and ultraviolet light for pathogen inactivation on quality of platelet concentrates

    Directory of Open Access Journals (Sweden)

    Stanojković Zoran

    2011-01-01

    Full Text Available Background/Aim. Pathogen inactivation in blood and blood products is one of the major means to achieve a zero risk blood supply and improve transfusion safety. Riboflavin (vitamin B2 activated by ultraviolet (UV light, produces active oxygen which damages cell membrane and prevents replication of the carrier of diseases (viruses, bacteria, protozoa in all blood products. The aim of this study was to establish the influence of the process of pathogens photoinactivation using riboflavin and UV rays on the biochemical and functional characteristics of platelet concentrates prepared from “buffy coat”. Methods. The examination included 80 platelet concentrates prepared from “buffy coat”, which was separated from whole blood donated by voluntary blood donors around 6 hours from the moment of collection. Concentrates were pooled, filtered and separated unton two groups: one consisted of 10 control units and the other of 10 examined units (pooled platelet concentrates. Examined units of the platelets were treated by riboflavin (35 mL and UV rays (6.24 J/mL, 265-370 nm on Mirasol aparature (Caridian BCT Biotechnologies, USA in approximate duration of 6 min. A total of 35 mL of saline solution was added to the control units. The samples for examining were taken from the control and examined units initially (K0, I0, after the addition of saline (K1 and riboflavin (I1, after illumination (I2, first day of storage (K3, I3 and the fifth day of storage (K4, I4. The following parameters were measured: platelet count and platelet yield, residual erythrocyte and leukocyte count, pH, pO2, pCO2 and bacterial contamination. Results. All the measured parameters showed a statistically significant decrease comparing to K0 and I0; all the results of the first day of platelet storage showed statistically significant decrease comparing to K1 and I1, and all the results of the fifth day of platelet storage (K4, I4 showed a statistically significant decrease

  17. Efficacy of Peracetic Acid in Inactivating Foodborne Pathogens on Fresh Produce Surface.

    Science.gov (United States)

    Singh, Prashant; Hung, Yen-Con; Qi, Hang

    2018-02-01

    Washing treatment with effective sanitizer is one of the critical steps in ensuring fresh produce safety. This study was to evaluate the efficacy of peracetic acid (PAA; VigorOx® 15 F&V), chlorine-based sanitizers (acidic electrolyzed water [AEO], near neutral electrolyzed water and bleach), lactic acid, and deionized (DI) water to reduce Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium DT104 from fresh produce surfaces. A 5-strain cocktail of E. coli O157:H7, L. monocytogenes, and S. Typhimurium DT104 was separately prepared and used for surface inoculation on produce samples (E. coli O157:H7 on romaine lettuce, lemons, tomatoes, and blueberries; L. monocytogenes on romaine lettuce and cantaloupe; S. Typhimurium DT104 on lemons, tomatoes, cantaloupe, and blueberries). PAA at 45, 85, and 100 mg/L; AEO, NNEO, and bleach at 100 mg/L of free chlorine; lactic acid at 2%; and DI water were used for washing inoculated produce in an automated produce washer for 5 min. In general, PAA at 100 mg/L achieved the highest microbial inactivation of E. coli O157:H7 (lettuce, lemon, tomato, and blueberry at 2.2, 5.7, 5.5, and 6.7 log CFU/g, respectively), S. Typhimurium DT104 (lemon, tomato, cantaloupe, blueberry at 5.4, 6.8, 4.5, and 5.9 log CFU/g, respectively), and L. monocytogenes (lettuce and cantaloupe at 2.4 and 4.4 log CFU/g, respectively). Efficacy of sanitizers on produce with coarse surface (for example, lettuce and cantaloupe) was lower than produce with smooth texture (lemon, tomato, and blueberry). Cross-contamination of E. coli O157:H7 among romaine lettuce heads during simulated retail crisping process was greatly reduced by the application of PAA and NNEO. NNEO and PAA showed high efficacy in foodborne pathogen removal from fresh produce. Produce surface texture plays an important role in pathogen removal. NNEO and PAA effectively prevented cross-contamination during the crisping process. © 2018 Institute of Food Technologists®.

  18. Inactivation of bacterial pathogens in yoba mutandabota, a dairy product fermented with the probiotic Lactobacillus rhamnosus yoba.

    Science.gov (United States)

    Mpofu, Augustine; Linnemann, Anita R; Nout, Martinus J R; Zwietering, Marcel H; Smid, Eddy J; den Besten, Heidy M W

    2016-01-18

    Mutandabota is a dairy product consumed as a major source of proteins and micronutrients in Southern Africa. In this study the microbial safety of traditional and a variant of mutandabota fermented with the probiotic Lactobacillus rhamnosus yoba (yoba mutandabota) was investigated by challenging the products with five important food pathogens: Listeria monocytogenes, Salmonella spp., Campylobacter jejuni, Escherichia coli O157:H7 and Bacillus cereus. Pasteurized full-fat cow's milk was used for producing traditional and yoba mutandabota, and was inoculated with a cocktail of strains of the pathogens at an inoculum level of 5.5 log cfu/mL. Survival of the pathogens was monitored over a potential consumption time of 24h for traditional mutandabota, and over 24h of fermentation followed by 24h of potential consumption time for yoba mutandabota. In traditional mutandabota (pH3.4 ± 0.1) no viable cells of B. cereus and C. jejuni were detected 3h after inoculation, while L. monocytogenes, E. coli O157:H7 and Salmonella spp. significantly declined (Pfermentation, mainly due to organic acids produced during fermentation. Only Salmonella spp. was able to grow in yoba mutandabota during the first 9h of fermentation, but then decreased in viable plate count. None of the tested pathogens were detected (>3.5 log inactivation) after 3h into potential consumption time of yoba mutandabota. Inactivation of pathogens in mutandabota is of public health significance because food-borne pathogens endanger public health upon consumption of contaminated food, especially in Southern Africa where there are many vulnerable consumers of mutandabota such as children, elderly and immuno-compromised people with HIV/AIDS. The findings of this study demonstrate that mutandabota fermented with L. rhamnosus yoba has antimicrobial properties against the tested pathogens and it is safer compared to the traditional mutandabota. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Prevalence of transfusion-transmitted viral pathogens among health-care workers and risk mitigation programme in a paediatric tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Charu Nayyar

    2017-01-01

    Full Text Available The health-care workers (HCWs are at an occupational risk of exposure to blood-borne pathogens, mainly, HIV, hepatitis B virus (HBV and hepatitis C virus. HBV is currently the only blood-borne virus for which a vaccine is available. All health-care institutions must encourage the HCWs to undergo screening for blood-borne pathogens.

  20. Two pathogen reduction technologies--methylene blue plus light and shortwave ultraviolet light--effectively inactivate hepatitis C virus in blood products.

    Science.gov (United States)

    Steinmann, Eike; Gravemann, Ute; Friesland, Martina; Doerrbecker, Juliane; Müller, Thomas H; Pietschmann, Thomas; Seltsam, Axel

    2013-05-01

    Contamination of blood products with hepatitis C virus (HCV) can cause infections resulting in acute and chronic liver diseases. Pathogen reduction methods such as photodynamic treatment with methylene blue (MB) plus visible light as well as irradiation with shortwave ultraviolet (UVC) light were developed to inactivate viruses and other pathogens in plasma and platelet concentrates (PCs), respectively. So far, their inactivation capacities for HCV have only been tested in inactivation studies using model viruses for HCV. Recently, a HCV infection system for the propagation of infectious HCV in cell culture was developed. Inactivation studies were performed with cell culture-derived HCV and bovine viral diarrhea virus (BVDV), a model for HCV. Plasma units or PCs were spiked with high titers of cell culture-grown viruses. After treatment of the blood units with MB plus light (Theraflex MB-Plasma system, MacoPharma) or UVC (Theraflex UV-Platelets system, MacoPharma), residual viral infectivity was assessed using sensitive cell culture systems. HCV was sensitive to inactivation by both pathogen reduction procedures. HCV in plasma was efficiently inactivated by MB plus light below the detection limit already by 1/12 of the full light dose. HCV in PCs was inactivated by UVC irradiation with a reduction factor of more than 5 log. BVDV was less sensitive to the two pathogen reduction methods. Functional assays with human HCV offer an efficient tool to directly assess the inactivation capacity of pathogen reduction procedures. Pathogen reduction technologies such as MB plus light treatment and UVC irradiation have the potential to significantly reduce transfusion-transmitted HCV infections. © 2012 American Association of Blood Banks.

  1. Effect of atmospheric pressure plasma on inactivation of pathogens inoculated onto bacon using two different gas compositions.

    Science.gov (United States)

    Kim, Binna; Yun, Hyejeong; Jung, Samooel; Jung, Yeonkook; Jung, Heesoo; Choe, Wonho; Jo, Cheorun

    2011-02-01

    Atmospheric pressure plasma (APP) is an emerging non-thermal pasteurization method for the enhancement of food safety. In this study, the effect of APP on the inactivation of pathogens inoculated onto bacon was observed. Sliced bacon was inoculated with Listeria monocytogenes (KCTC 3596), Escherichia coli (KCTC 1682), and Salmonella Typhimurium (KCTC 1925). The samples were treated with APP at 75, 100, and 125 W of input power for 60 and 90 s. Two gases, helium (10 lpm) or a mixture of helium and oxygen, (10 lpm and 10 sccm, respectively) were used for the plasma generation. Plasma with helium could only reduce the number of inoculated pathogens by about 1-2 Log cycles. On the other hand, the helium/oxygen gas mixture was able to achieve microbial reduction of about 2-3 Log cycles. The number of total aerobic bacteria showed 1.89 and 4.58 decimal reductions after plasma treatment with helium and the helium/oxygen mixture, respectively. Microscopic observation of the bacon after plasma treatment did not find any significant changes, except that the L∗-value of the bacon surface was increased. These results clearly indicate that APP treatment is effective for the inactivation of the three pathogens used in this study, although further investigation is needed for elucidating quality changes after treatment. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. The control of H5 or H7 mildly pathogenic avian influenza: a role for inactivated vaccine.

    Science.gov (United States)

    Halvorson, David A

    2002-02-01

    Biosecurity is the first line of defence in the prevention and control of mildly pathogenic avian influenza (MPAI). Its use has been highly successful in keeping avian influenza (AI) out of commercial poultry worldwide. However, sometimes AI becomes introduced into poultry populations and, when that occurs, biosecurity again is the primary means of controlling the disease. There is agreement that routine serological monitoring, disease reporting, isolation or quarantine of affected flocks, application of strict measures to prevent the contamination of and movement of people and equipment, and changing flock schedules are necessities for controlling AI. There is disagreement as to the disposition of MPAI-infected flocks: some advocate their destruction and others advocate controlled marketing. Sometimes biosecurity is not enough to stop the spread of MPAI. In general, influenza virus requires a dense population of susceptible hosts to maintain itself. When there is a large population of susceptible poultry in an area, use of an inactivated AI vaccine can contribute to AI control by reducing the susceptibility of the population. Does use of inactivated vaccine assist, complicate or interfere with AI control and eradication? Yes, it assists MPAI control (which may reduce the risk of highly pathogenic AI (HPAI)) but, unless steps are taken to prevent it, vaccination may interfere with sero-epidemiology in the case of an HPAI outbreak. Does lack of vaccine assist, complicate or interfere with AI control and eradication? Yes, it assists in identification of sero-positive (convalescent) flocks in a HPAI eradication program, but it interferes with MPAI control (which in turn may increase the risk of emergence of HPAI).A number of hypothetical concerns have been raised about the use of inactivated AI vaccines. Infection of vaccinated flocks, serology complications and spreading of virus by vaccine crews are some of the hypothetical concerns. The discussion of these concerns

  3. Thin-film fixed-bed reactor (TFFBR for solar photocatalytic inactivation of aquaculture pathogen Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    Khan Sadia J

    2012-01-01

    Full Text Available Abstract Background Outbreaks of infectious diseases by microbial pathogens can cause substantial losses of stock in aquaculture systems. There are several ways to eliminate these pathogens including the use of antibiotics, biocides and conventional disinfectants, but these leave undesirable chemical residues. Conversely, using sunlight for disinfection has the advantage of leaving no chemical residue and is particularly suited to countries with sunny climates. Titanium dioxide (TiO2 is a photocatalyst that increases the effectiveness of solar disinfection. In recent years, several different types of solar photocatalytic reactors coated with TiO2 have been developed for waste water and drinking water treatment. In this study a thin-film fixed-bed reactor (TFFBR, designed as a sloping flat plate reactor coated with P25 DEGUSSA TiO2, was used. Results The level of inactivation of the aquaculture pathogen Aeromonas hydrophila ATCC 35654 was determined after travelling across the TFFBR under various natural sunlight conditions (300-1200 W m-2, at 3 different flow rates (4.8, 8.4 and 16.8 L h-1. Bacterial numbers were determined by conventional plate counting using selective agar media, cultured (i under conventional aerobic conditions to detect healthy cells and (ii under conditions designed to neutralise reactive oxygen species (agar medium supplemented with the peroxide scavenger sodium pyruvate at 0.05% w/v, incubated under anaerobic conditions, to detect both healthy and sub-lethally injured (oxygen-sensitive cells. The results clearly demonstrate that high sunlight intensities (≥ 600 W m-2 and low flow rates (4.8 L h-1 provided optimum conditions for inactivation of A. hydrophila ATCC 3564, with greater overall inactivation and fewer sub-lethally injured cells than at low sunlight intensities or high flow rates. Low sunlight intensities resulted in reduced overall inactivation and greater sub-lethal injury at all flow rates. Conclusions This

  4. Pulsed-light inactivation of pathogenic and spoilage bacteria on cheese surface.

    Science.gov (United States)

    Proulx, J; Hsu, L C; Miller, B M; Sullivan, G; Paradis, K; Moraru, C I

    2015-09-01

    Cheese products are susceptible to postprocessing cross-contamination by bacterial surface contamination during slicing, handling, or packaging, which can lead to food safety issues and significant losses due to spoilage. This study examined the effectiveness of pulsed-light (PL) treatment on the inactivation of the spoilage microorganism Pseudomonas fluorescens, the nonenterohemorrhagic Escherichia coli ATCC 25922 (nonpathogenic surrogate of Escherichia coli O157:H7), and Listeria innocua (nonpathogenic surrogate of Listeria monocytogenes) on cheese surface. The effects of inoculum level and cheese surface topography and the presence of clear polyethylene packaging were evaluated in a full factorial experimental design. The challenge microorganisms were grown to early stationary phase and subsequently diluted to reach initial inoculum levels of either 5 or 7 log cfu/slice. White Cheddar and process cheeses were cut into 2.5×5 cm slices, which were spot-inoculated with 100 µL of bacterial suspension. Inoculated cheese samples were exposed to PL doses of 1.02 to 12.29 J/cm(2). Recovered survivors were enumerated by standard plate counting or the most probable number technique, as appropriate. The PL treatments were performed in triplicate and data were analyzed using a general linear model. Listeria innocua was the least sensitive to PL treatment, with a maximum inactivation level of 3.37±0.2 log, followed by P. fluorescens, with a maximum inactivation of 3.74±0.8 log. Escherichia coli was the most sensitive to PL, with a maximum reduction of 5.41±0.1 log. All PL inactivation curves were nonlinear, and inactivation reached a plateau after 3 pulses (3.07 J/cm(2)). The PL treatments through UV-transparent packaging and without packaging consistently resulted in similar inactivation levels. This study demonstrates that PL has strong potential for decontamination of the cheese surface. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc

  5. Microencapsulated antimicrobial compounds as a means to enhance electron beam irradiation treatment for inactivation of pathogens on fresh spinach leaves.

    Science.gov (United States)

    Gomes, Carmen; Moreira, Rosana G; Castell-Perez, Elena

    2011-08-01

    Recent outbreaks associated to the consumption of raw or minimally processed vegetable products that have resulted in several illnesses and a few deaths call for urgent actions aimed at improving the safety of those products. Electron beam irradiation can extend shelf-life and assure safety of fresh produce. However, undesirable effects on the organoleptic quality at doses required to achieve pathogen inactivation limit irradiation. Ways to increase pathogen radiation sensitivity could reduce the dose required for a certain level of microbial kill. The objective of this study was to evaluate the effectiveness of using natural antimicrobials when irradiating fresh produce. The minimum inhibitory concentration of 5 natural compounds and extracts (trans-cinnamaldehyde, eugenol, garlic extract, propolis extract, and lysozyme with ethylenediaminetetraacetate acid (disodium salt dihydrate) was determined against Salmonella spp. and Listeria spp. In order to mask odor and off-flavor inherent of several compounds, and to increase their solubility, complexes of these compounds and extracts with β-cyclodextrin were prepared by the freeze-drying method. All compounds showed bacteriostatic effect at different levels for both bacteria. The effectiveness of the microencapsulated compounds was tested by spraying them on the surface of baby spinach inoculated with Salmonella spp. The dose (D₁₀ value) required to reduce the bacterial population by 1 log was 0.190 kGy without antimicrobial addition. The increase in radiation sensitivity (up to 40%) varied with the antimicrobial compound. These results confirm that the combination of spraying microencapsulated antimicrobials with electron beam irradiation was effective in increasing the killing effect of irradiation. Foodborne illness outbreaks attributed to fresh produce consumption have increased and present new challenges to food safety. Current technologies (water washing or treating with 200 ppm chlorine) cannot

  6. Gamma radiation inactivation of pathogens in sludge under larger-scale condition

    Energy Technology Data Exchange (ETDEWEB)

    Sermkiattipong, N; Pongpat, S

    1996-12-01

    The effect of gamma radiation on microorganisms in sludge from Huay Kwang Sewage Treatment Plant and Vajira Hospital showed that total bacterial counts were reduced to 2-3 log cycles and 1-2 log cycles at 5 kGy irradiation with and without aeration, respectively. Inactivation of coliform bacteria in sludge required irradiation with and without aeration at the dosages of 3-4.5 and 4-5 kGy, respectively. A dose of 2-3 kGy was sufficient to inactivate fecal coliform bacteria and E. coli. The doses used for inactivation these bacteria depend on the irradiation condition and solid content in sludge sample. Irradiation with aeration led to an increased microbial inactivation. According to our results, the frequency of occurrence of salmonella e contaminated in sludge from Huay Kwang Sewage Treatment Plant and Vajira Hospital was 50% and 75%, respectively. A dose of 2 kGy irradiation with or without aeration, salmonella e could not be detected in any sludge. Clostridium perfringens organisms were also detected in non-irradiated and irradiated sludge from both sources. Moreover, a dose of 5 kGy irradiation with or without aeration was not enough to eliminate C. perfringens. However, no shigella e were isolated from any treatment of sludge

  7. Gamma radiation inactivation of pathogens in sludge under larger-scale condition

    International Nuclear Information System (INIS)

    Sermkiattipong, N.; Pongpat, S.

    1996-01-01

    The effect of gamma radiation on microorganisms in sludge from Huay Kwang Sewage Treatment Plant and Vajira Hospital showed that total bacterial counts were reduced to 2-3 log cycles and 1-2 log cycles at 5 kGy irradiation with and without aeration, respectively. Inactivation of coliform bacteria in sludge required irradiation with and without aeration at the dosages of 3-4.5 and 4-5 kGy, respectively. A dose of 2-3 kGy was sufficient to inactivate fecal coliform bacteria and E. coli. The doses used for inactivation these bacteria depend on the irradiation condition and solid content in sludge sample. Irradiation with aeration led to an increased microbial inactivation. According to our results, the frequency of occurrence of salmonella e contaminated in sludge from Huay Kwang Sewage Treatment Plant and Vajira Hospital was 50% and 75%, respectively. A dose of 2 kGy irradiation with or without aeration, salmonella e could not be detected in any sludge. Clostridium perfringens organisms were also detected in non-irradiated and irradiated sludge from both sources. Moreover, a dose of 5 kGy irradiation with or without aeration was not enough to eliminate C. perfringens. However, no shigella e were isolated from any treatment of sludge

  8. INACTIVATION OF PATHOGENIC BACTERIA USING PULSED UV-LIGHT AND ITS APPLICATION IN WATER DISINFECTION AND QUALITY CONTROL

    Directory of Open Access Journals (Sweden)

    M. K. Sharifi-Yazdi H. Darghahi

    2006-09-01

    Full Text Available The lethality of pulsed ultra-violet (UV rich light for the inactivation of pathogenic bacteria has been investigated. A low pressure xenon filled flash lamps that produced UV intensities have been used. The pulsed operation of the system enable the release of electrical energy stored in the capacitor into the flash lamp within a short time and produces the high current and high peak power required for emitting the intense UV flash. The flash frequency was adjusted to one pulse per second. Several types of bacteria were investigated for their susceptibility to pulsed UV illumination. The treated bacterial populations were reduced and determined by direct viable counts. Among the tested bacteria Pseudomonas aeruginosa was the most susceptible to the pulsed UV- light with a 8 log10 cfu/ml reduction after 11 pulses, while the spores of Bacillus megaterium was the most resistant and only 4 log10 cfu/ml reduction achieved after 50 pulses of illumination. The results of this study demonstrated that pulsed UV- light technology could be used as an effective method for the inactivation, of pathogenic bacteria in different environments such as drinking water.

  9. Composition of growth factors and cytokines in lysates obtained from fresh versus stored pathogen-inactivated platelet units.

    Science.gov (United States)

    Sellberg, Felix; Berglund, Erik; Ronaghi, Martin; Strandberg, Gabriel; Löf, Helena; Sommar, Pehr; Lubenow, Norbert; Knutson, Folke; Berglund, David

    2016-12-01

    Platelet lysate is a readily available source of growth factors, and other mediators, which has been used in a variety of clinical applications. However, the product remains poorly standardized and the present investigation evaluates the composition of platelet lysate obtained from either fresh or stored pathogen-inactivated platelet units. Platelet pooled units (n = 10) were obtained from healthy blood donors and tested according to standard procedures. All units were pathogen inactivated using amotosalen hydrochloride and UVA exposure. Platelet lysate was subsequently produced at two separate time-points, either from fresh platelet units or after 5 days of storage, by repeated freeze-thaw cycles. The following mediators were determined at each time-point: EGF, FGF-2, VEGF, IGF-1, PDGF-AB/BB, BMP-2, PF4, TGF-β isoform 1, IL-1β, IL-2, IL-6, IL-10, IL-12p70, 1L-17A, TNF-α, and IFN-γ. The concentration of growth factors and cytokines was affected by time in storage. Notably, TGF-β, PDGF-AB/BB, and PF4 showed an increase of 27.2% (p product, which potentially may influence the clinical effects. Copyright © 2016. Published by Elsevier Ltd.

  10. Non-thermal plasma-activated water inactivation of food-borne pathogen on fresh produce

    International Nuclear Information System (INIS)

    Ma, Ruonan; Wang, Guomin; Tian, Ying; Wang, Kaile; Zhang, Jue; Fang, Jing

    2015-01-01

    Highlights: • We propose a new approach to treat S. aureus inoculated on strawberries by PAW. • PAW could inactivate S. aureus on strawberries via the Log Reduction results, further confirmed by CLSM and SEM. • The short-lived ROS in PAW are considered the most important agents in inactivation process. • No significant change was found in color, firmness and pH of the PAW treated strawberries. - Abstract: Non-thermal plasma has been widely considered to be an effective method for decontamination of foods. Recently, numerous studies report that plasma-activated water (PAW) also has outstanding antibacterial ability. This study presents the first report on the potential of PAW for the inactivation of Staphylococcus aureus (S. aureus) inoculated on strawberries. PAW treatments achieved a reduction of S. aureus ranging from 1.6 to 2.3 log at day-0 storage, while 1.7 to 3.4 log at day-4 storage. The inactivation efficiency depended on the plasma-activated time for PAW generation and PAW-treated time of strawberries inoculated with S. aureus. LIVE/DEAD staining and scanning electron microscopy results confirm that PAW could damage the bacterial cell wall. Moreover, optical emission spectra and oxidation reduction potential results demonstrate the inactivation is mainly attributed to oxidative stress induced by reactive oxygen species in PAW. In addition, no significant change was found in color, firmness and pH of the PAW treated strawberries. Thus, PAW can be a promising alternative to traditional sanitizers applied in the fresh produce industry.

  11. Non-thermal plasma-activated water inactivation of food-borne pathogen on fresh produce

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ruonan; Wang, Guomin; Tian, Ying; Wang, Kaile [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang, Jue, E-mail: zhangjue@pku.edu.cn [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China); Fang, Jing [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China)

    2015-12-30

    Highlights: • We propose a new approach to treat S. aureus inoculated on strawberries by PAW. • PAW could inactivate S. aureus on strawberries via the Log Reduction results, further confirmed by CLSM and SEM. • The short-lived ROS in PAW are considered the most important agents in inactivation process. • No significant change was found in color, firmness and pH of the PAW treated strawberries. - Abstract: Non-thermal plasma has been widely considered to be an effective method for decontamination of foods. Recently, numerous studies report that plasma-activated water (PAW) also has outstanding antibacterial ability. This study presents the first report on the potential of PAW for the inactivation of Staphylococcus aureus (S. aureus) inoculated on strawberries. PAW treatments achieved a reduction of S. aureus ranging from 1.6 to 2.3 log at day-0 storage, while 1.7 to 3.4 log at day-4 storage. The inactivation efficiency depended on the plasma-activated time for PAW generation and PAW-treated time of strawberries inoculated with S. aureus. LIVE/DEAD staining and scanning electron microscopy results confirm that PAW could damage the bacterial cell wall. Moreover, optical emission spectra and oxidation reduction potential results demonstrate the inactivation is mainly attributed to oxidative stress induced by reactive oxygen species in PAW. In addition, no significant change was found in color, firmness and pH of the PAW treated strawberries. Thus, PAW can be a promising alternative to traditional sanitizers applied in the fresh produce industry.

  12. Study on Efficacy of Gamma Radiation on the Inactivation of Highly Pathogenic Avian Influenza Virus H5N1 (Thai isolate) in Chicken Meat and Chicken Feces

    International Nuclear Information System (INIS)

    Pinyochon, Wasana; Piadang, Nattayana; Mulika, Ladda; Parchariyanon, Sujira; Vitittheeranon, Arag; Damrongwatapokin, Sudarat

    2006-09-01

    A study on the efficacy of gamma radiation on the inactivation of a highly pathogenic avian influenza virus H5N1 subtype, Thai isolate was carried out. The virus was in the form frozen infected allantoic fluid frozen chicken meat and frozen chicken feces. The result indicated that 9 kilo grey of gamma radiation could completely inactivated 106.0 EID50/ml of AIV infected allantoic fluid and 22 kiel grey and 15 kilo grey of gamma radiation completely inactivate 106.0 EID50/10/ grams of chicken meat and 106.0 EID50/5 grams of chicken feces respectively.

  13. Application of low frequency pulsed ohmic heating for inactivation of foodborne pathogens and MS-2 phage in buffered peptone water and tomato juice.

    Science.gov (United States)

    Kim, Sang-Soon; Choi, Won; Kang, Dong-Hyun

    2017-05-01

    The purpose of this study was to inactivate foodborne pathogens effectively by ohmic heating in buffered peptone water and tomato juice without causing electrode corrosion and quality degradation. Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes were used as representative foodborne pathogens and MS-2 phage was used as a norovirus surrogate. Buffered peptone water and tomato juice inoculated with pathogens were treated with pulsed ohmic heating at different frequencies (0.06-1 kHz). Propidium iodide uptake values of bacterial pathogens were significantly (p heating is applicable to inactivate foodborne pathogens effectively without causing electrode corrosion and quality degradation in tomato juice. Copyright © 2016. Published by Elsevier Ltd.

  14. Cold plasma inactivation of human pathogens on foods and regulatory status update

    Science.gov (United States)

    Contamination of foods with human pathogens such as Salmonella, Listeria monocytogenes, Escherichia coli O157:H7, norovirus, and other pathogens is an ongoing challenge for growers and processors. In recent years, cold plasma has emerged as a promising antimicrobial treatment for fresh and fresh-cut...

  15. Gamma irradiation inactivates honey bee fungal, microsporidian, and viral pathogens and parasites

    Science.gov (United States)

    Managed honey bee (Apis mellifera) populations are currently facing unsustainable losses due to a variety of factors. Colonies are challenged with brood pathogens, such as the fungal agent of chalkbrood disease, the microsporidian gut parasite Nosema sp., and several viruses. These pathogens may be ...

  16. Synthetic protocells interact with viral nanomachinery and inactivate pathogenic human virus.

    Directory of Open Access Journals (Sweden)

    Matteo Porotto

    Full Text Available We present a new antiviral strategy and research tool that could be applied to a wide range of enveloped viruses that infect human beings via membrane fusion. We test this strategy on two emerging zoonotic henipaviruses that cause fatal encephalitis in humans, Nipah (NiV and Hendra (HeV viruses. In the new approach, artificial cell-like particles (protocells presenting membrane receptors in a biomimetic manner were developed and found to attract and inactivate henipavirus envelope glycoprotein pseudovirus particles, preventing infection. The protocells do not accumulate virus during the inactivation process. The use of protocells that interact with, but do not accumulate, viruses may provide significant advantages over current antiviral drugs, and this general approach may have wide potential for antiviral development.

  17. Inactivated Recombinant Rabies Viruses Displaying Canine Distemper Virus Glycoproteins Induce Protective Immunity against Both Pathogens

    OpenAIRE

    da Fontoura Budaszewski, Renata; Hudacek, Andrew; Sawatsky, Bevan; Krämer, Beate; Yin, Xiangping; Schnell, Matthias J.; von Messling, Veronika

    2017-01-01

    The development of multivalent vaccines is an attractive methodology for the simultaneous prevention of several infectious diseases in vulnerable populations. Both canine distemper virus (CDV) and rabies virus (RABV) cause lethal disease in wild and domestic carnivores. While RABV vaccines are inactivated, the live-attenuated CDV vaccines retain residual virulence for highly susceptible wildlife species. In this study, we developed recombinant bivalent vaccine candidates based on recombinant ...

  18. The Plant Ribosome-Inactivating Proteins Play Important Roles in Defense against Pathogens and Insect Pest Attacks

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    Feng Zhu

    2018-02-01

    Full Text Available Ribosome-inactivating proteins (RIPs are toxic N-glycosidases that depurinate eukaryotic and prokaryotic rRNAs, thereby arresting protein synthesis during translation. RIPs are widely found in various plant species and within different tissues. It is demonstrated in vitro and in transgenic plants that RIPs have been connected to defense by antifungal, antibacterial, antiviral, and insecticidal activities. However, the mechanism of these effects is still not completely clear. There are a number of reviews of RIPs. However, there are no reviews on the biological functions of RIPs in defense against pathogens and insect pests. Therefore, in this report, we focused on the effect of RIPs from plants in defense against pathogens and insect pest attacks. First, we summarize the three different types of RIPs based on their physical properties. RIPs are generally distributed in plants. Then, we discuss the distribution of RIPs that are found in various plant species and in fungi, bacteria, algae, and animals. Various RIPs have shown unique bioactive properties including antibacterial, antifungal, antiviral, and insecticidal activity. Finally, we divided the discussion into the biological roles of RIPs in defense against bacteria, fungi, viruses, and insects. This review is focused on the role of plant RIPs in defense against bacteria, fungi, viruses, and insect attacks. The role of plant RIPs in defense against pathogens and insects is being comprehended currently. Future study utilizing transgenic technology approaches to study the mechanisms of RIPs will undoubtedly generate a better comprehending of the role of plant RIPs in defense against pathogens and insects. Discovering additional crosstalk mechanisms between RIPs and phytohormones or reactive oxygen species (ROS against pathogen and insect infections will be a significant subject in the field of biotic stress study. These studies are helpful in revealing significance of genetic control that can

  19. Thermal treatment for pathogen inactivation as a risk mitigation strategy for safe recycling of organic waste in agriculture.

    Science.gov (United States)

    Elving, Josefine; Vinnerås, Björn; Albihn, Ann; Ottoson, Jakob R

    2014-01-01

    Thermal treatment at temperatures between 46.0°C and 55.0°C was evaluated as a method for sanitization of organic waste, a temperature interval less commonly investigated but important in connection with biological treatment processes. Samples of dairy cow feces inoculated with Salmonella Senftenberg W775, Enterococcus faecalis, bacteriophage ϕX174, and porcine parvovirus (PPV) were thermally treated using block thermostats at set temperatures in order to determine time-temperature regimes to achieve sufficient bacterial and viral reduction, and to model the inactivation rate. Pasteurization at 70°C in saline solution was used as a comparison in terms of bacterial and viral reduction and was proven to be effective in rapidly reducing all organisms with the exception of PPV (decimal reduction time of 1.2 h). The results presented here can be used to construct time-temperature regimes in terms of bacterial inactivation, with D-values ranging from 0.37 h at 55°C to 22.5 h at 46.0°C and 0.45 h at 55.0°C to 14.5 h at 47.5°C for Salmonella Senftenberg W775 and Enterococcus faecalis, respectively and for relevant enteric viruses based on the ϕX174 phage with decimal reduction times ranging from 1.5 h at 55°C to 16.5 h at 46°C. Hence, the study implies that considerably lower treatment temperatures than 70°C can be used to reach a sufficient inactivation of bacterial pathogens and potential process indicator organisms such as the ϕX174 phage and raises the question whether PPV is a valuable process indicator organism considering its extreme thermotolerance.

  20. Antimicrobial blue light: a drug-free approach for inactivating pathogenic microbes

    Science.gov (United States)

    Wang, Ying; Dai, Tianhong

    2018-02-01

    Due to the growing global threat of antibiotic resistance, there is a critical need for the development of alternative therapeutics for infectious diseases. Antimicrobial blue light (aBL), as an innovative non-antibiotic approach, has attracted increasing attention. This paper discussed the basic concepts of aBL and recent findings in the studies of aBL. It is commonly hypothesized that the antimicrobial property of aBL is attributed to the presence of endogenous photosensitizing chromophores in microbial cells, which produce cytotoxic reactive oxygen species upon light irradiation. A wide range of important microbes are found to be susceptible to aBL inactivation. Studies have also shown there exist therapeutic windows where microbes are selectively inactivated by aBL while host cells are preserved. The combination of aBL with some other agents result in synergistically improved antimicrobial efficacy. Future efforts should be exerted on the standardization of study design for evaluating aBL efficacy, further elucidation of the mechanism of action, optimization of the technical parameters, and translation of this technique to clinic.

  1. Plant extracts, spices, and essential oils inactivate E. coli O157:H7 pathogens and reduce formation of potentially carcinogenic heterocyclic amines in grilled beef patties

    Science.gov (United States)

    Meats need to be sufficiently heated to inactivate foodborne pathogens such as Escherichia coli O157:H7. High-temperature heat treatment used to prepare well-done meats could, however, increase the formation of potentially carcinogenic heterocyclic amines (HCAs). The objective of this study was to ...

  2. A COMPARISON OF THREE ASSAY PROCEDURES FOR DETERMINING CHLORINE INACTIVATION OF WATERBORNE PATHOGENIC BACTERIA

    Science.gov (United States)

    One criterion on which chlorine treatment of water may be based is the concentration (C) in mg/l multiplied by the time (t) in min of exposure or Ct values. We compared different Ct values on waterborne pathogenic bacteria by cultural assay for viability and 2 assays that mea...

  3. PHOTODYNAMIC INACTIVATION OF PATHOGENIC BACTERIA IN BIOFILMS USING NEW SYNTHETIC BACTERIOCHLORIN DERIVATIVES

    Directory of Open Access Journals (Sweden)

    I. G. Tiganova

    2017-01-01

    Full Text Available Bacteriochlorins as the antimicrobial photosensitizers have a promising future in the face of the unrelenting increase in antimicrobial resistance. The goal of this study was to investigate the infl uence of lipophilicity and number of positively charged  substituents in these molecules on the photodynamic inactivation  (PDI of biofi lm bacteria in vitro. Testing how bacteriochlorin  derivatives with different properties affect microbes will allow to  determine the optimal ratio of these parameters within a single  molecule. We have investigated 4 bacteriochlorin derivatives, all of  which were synthesized in Organic Intermediates and Dyes Institute. These were: hydrophobic neutral meso-tetra(3-pyridyl  bacteriochlorin (ВС1, amphyphilic tetracationic meso-tetra(1- undecyl-3-pyridylbacteriochlorin tetrabromide (ВС2, hydrophilic  tetracationic meso-tetra[1-(4'-bromobutyl-3-pyridyl]bacteriochlorin  tetrabromide (ВС3 and octacationic meso-tetra[1-(4'-pyridiniobutyl -3-pyridyl]bacteriochlorin octabromide (ВС4 . The water-soluble  cationic bacteriochlorin derivatives showed the most effective PDI of  bacteria in biofi lms. While tetracationic BC3 caused total inactivation of S. aureus 15, octacationic BC4 was bactericidal for P. aeruginosa  32 to the same degree (>99.999%. Interestingly, increasing the  number of cationic substituents from 4 to 8 in bacteriochlorin  molecules enhances bactericidal action against gram-negative  bacteria in biofi lms. The lack of charge-carrying groups and high  degree of lipophilicity of PS have negative impact on PDI of biofi lm  bacteria. Bacterial membrane damage as a result of PDI can be one of the causes of cell death.

  4. Effectiveness of inactivation of foodborne pathogens during simulated home pan frying of steak, hamburger or meat strips.

    Science.gov (United States)

    Lahou, Evy; Wang, Xiang; De Boeck, Elien; Verguldt, Elien; Geeraerd, Annemie; Devlieghere, Frank; Uyttendaele, Mieke

    2015-08-03

    In order to evaluate the effect of simulated home pan frying of raw meat and meat preparations of different animal species on the thermal inactivation of pathogens, the heat resistance (D-value) of three strains of Campylobacter jejuni, Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and two strains of generic E. coli was validated in BHI and adjusted BHI (i.e. pH5.6 and 1.5% NaCl) at 60°C. The D-values were obtained of the linear phase of the survivor curves created in GInaFiT, a freeware tool to fit models to experimental data. The obtained D-values corresponded to those previously published in literature and confirmed L. monocytogenes to be the most heat resistant pathogen among them. Heat treatment in adjusted BHI significantly increased heat-resistance of E. coli O157:H7 and generic E. coli. Subsequently, the thermal inactivation of L. monocytogenes, Salmonella spp., C. jejuni and E. coli O157:H7 was evaluated using a standardized procedure simulating commonly used home pan frying of various types of meat including steaks or filets, hamburgers and meat strips from various animal species such as pork, beef, chicken, lamb and some turkey, horse, kangaroo and crocodile meat. Corresponding F70-values were calculated based upon measured core time/temperature profiles. It was noted that a core temperature of 70 °C was not always achieved and, moreover, a heat treatment equivalent to 2 min at 70 °C was also not always obtained. This was in particular noted in hamburgers although the meat was visually judged well done. On several occasions, residual survivors of the initial inoculated (4 logCFU/g) food borne pathogens could be recovered either by enumeration (limit of detection 1 logCFU/g) or by the presence/absence testing per 25 g. Pan frying of hamburgers yielded the highest number of surviving pathogenic bacteria (46%), followed by well-done filets and steaks (13%) and meat strips (12%). Taking only steaks (beef, horse, kangaroo, crocodile and

  5. Efficacy of Combined Sous Vide-Microwave Cooking for Foodborne Pathogen Inactivation in Ready-to-Eat Chicory Stems.

    Science.gov (United States)

    Renna, Massimiliano; Gonnella, Maria; de Candia, Silvia; Serio, Francesco; Baruzzi, Federico

    2017-07-01

    There is a variety of different food processing methods, which can be used to prepare ready-to-eat foods. However, the need to preserve the freshness and nutritional qualities leads to the application of mild technologies which may be insufficient to inactivate microbial pathogens. In this work, fresh chicory stems were packed under a vacuum in films, which were transparent to microwaves. These were then exposed to microwaves for different periods of time. The application of sous vide microwave cooking (SV-MW, 900 W, 2450 MHz), controlled naturally occurring mesophilic aerobic bacteria, yeasts and molds for up to 30 d when vacuum-packed vegetables were stored at 4 °C. In addition, the process lethality of the SV-MW 90 s cooking was experimentally validated. This treatment led to 6.07 ± 0.7 and 4.92 ± 0.65 log cfu/g reduction of Escherichia coli and Listeria monocytogenes inoculated over the chicory stems (100 g), respectively. With an initial load of 9 log cfu/g for both pathogens, less than 10 cfu/g of surviving cells were found after 90 s cooking. This shows that short-time microwave cooking can be used to effectively pasteurize vacuum-packed chicory stems, achieving >5 log cfu/g reduction of E. coli and L. monocytogenes. © 2017 Institute of Food Technologists®.

  6. Methods for thermal inactivation of pathogens in mozzarella: a comparison between stretching and pasteurization

    Directory of Open Access Journals (Sweden)

    D.C. Raimundo

    2013-04-01

    Full Text Available This study aimed to evaluate the efficiency of stretching in the reduction of pathogens when compared to milk pasteurization, the official method to ensure safe cheese production. Whole buffalo milk was contaminated with Mycobacterium fortuitum, Listeria monocytogenes, Salmonella typhimurium, and Staphylococcus aureus. Part of the milk was used in mozzarella production and the other part was submitted to holder pasteurization. Pathogens were quantified before and after thermal processing (mozzarella stretching and milk pasteurization. Pasteurization and stretching led to the following reductions in log cycles, respectively: 4.0 and 6.3 for Mycobacterium sp.; 6.0 and 8.4 for Listeria sp.; >6.8 and 4.5 for Staphylococcus sp.; and >8.2 and 7.5 for Salmonella sp.

  7. New Approach to Inactivation of Harmful and Pathogenic Microorganisms by Photosensitization

    Directory of Open Access Journals (Sweden)

    Živile Lukšiene

    2005-01-01

    Full Text Available Photosensitization is a treatment involving the administration of a photoactive compound that selectively accumulates in the target cells or microorganisms and is followed by irradiation with visible light. The combination of the two absolutely nontoxic elements, drug and light, in the presence of oxygen results in the selective destruction of target microorganism. It is important to note that truly major advances have been made in photosensitized antimicrobial chemotherapy, in particular disinfection of the blood and blood products, or treating local infections. By no means, prevention of any disease by microbial control of environment, including food manufacturing, is of greatest importance. Thus, development of new antimicrobial methods is necessary. In this context, photosensitization has been shown to be really effective: different microorganisms such as drug-resistant bacteria, yeasts, viruses and parasites can be inactivated by this method. So far, a photosensitization phenomenon can open new and interesting avenues for the development of novel, effective and ecologically friendly antimicrobial treatment, which might be applied to increase food safety.

  8. The location of splenic NKT cells favours their rapid activation by blood-borne antigen.

    Science.gov (United States)

    Barral, Patricia; Sánchez-Niño, María Dolores; van Rooijen, Nico; Cerundolo, Vincenzo; Batista, Facundo D

    2012-05-16

    Natural killer T (NKT) cells play an important role in mounting protective responses to blood-borne infections. However, though the spleen is the largest blood filter in the body, the distribution and dynamics of NKT cells within this organ are not well characterized. Here we show that the majority of NKT cells patrol around the marginal zone (MZ) and red pulp (RP) of the spleen. In response to lipid antigen, these NKT cells become arrested and rapidly produce cytokines, while the small proportion of NKT cells located in the white pulp (WP) exhibit limited activation. Importantly, disruption of the splenic MZ by chemical or genetic approaches results in a severe reduction in NKT cell activation indicating the need of cooperation between both MZ macrophages and dendritic cells for efficient NKT cell responses. Thus, the location of splenic NKT cells in the MZ and RP facilitates their access to blood-borne antigen and enables the rapid initiation of protective immune responses.

  9. A multicentre molecular analysis of hepatitis B and blood-borne virus coinfections in Viet Nam.

    Science.gov (United States)

    Dunford, Linda; Carr, Michael J; Dean, Jonathan; Nguyen, Linh Thuy; Ta Thi, Thu Hong; Nguyen, Binh Thanh; Connell, Jeff; Coughlan, Suzie; Nguyen, Hien Tran; Hall, William W; Thi, Lan Anh Nguyen

    2012-01-01

    Hepatitis B (HBV) infection is endemic in Viet Nam, with up to 8.4 million individuals estimated to be chronically infected. We describe results of a large, multicentre seroepidemiological and molecular study of the prevalence of HBV infection and blood-borne viral coinfections in Viet Nam. Individuals with varying risk factors for infection (n = 8654) were recruited from five centres; Ha Noi, Hai Phong, Da Nang, Khanh Hoa and Can Tho. A mean prevalence rate of 10.7% was observed and levels of HBsAg were significantly higher in injecting drug users (IDUs) (17.4%, n = 174/1000) and dialysis patients (14.3%, n = 82/575) than in lower-risk groups (9.4%; pViet Nam and also highlights the significant levels of blood-borne virus coinfections, which have important implications for hepatitis-related morbidity and development of effective management strategies.

  10. Pathogen inactivation efficacy of Mirasol PRT System and Intercept Blood System for non-leucoreduced platelet-rich plasma-derived platelets suspended in plasma.

    Science.gov (United States)

    Kwon, S Y; Kim, I S; Bae, J E; Kang, J W; Cho, Y J; Cho, N S; Lee, S W

    2014-10-01

    This study was conducted to evaluate the efficacy of pathogen inactivation (PI) in non-leucoreduced platelet-rich plasma-derived platelets suspended in plasma using the Mirasol PRT System and the Intercept Blood System. Platelets were pooled using the Acrodose PL system and separated into two aliquots for Mirasol and Intercept treatment. Four replicates of each viral strain were used for the evaluation. For bacteria, both low-titre (45-152 CFU/unit) inoculation and high-titre (7·34-10·18 log CFU/unit) inoculation with two replicates for each bacterial strain were used. Platelets with non-detectable bacterial growth and platelets inoculated with a low titre were stored for 5 days, and culture was performed with the BacT/ALERT system. The inactivation efficacy expressed as log reduction for Mirasol and Intercept systems for viruses was as follows: human immunodeficiency virus 1, ≥4·19 vs. ≥4·23; bovine viral diarrhoea virus, 1·83 vs. ≥6·03; pseudorabies virus, 2·73 vs. ≥5·20; hepatitis A virus, 0·62 vs. 0·76; and porcine parvovirus, 0·28 vs. 0·38. The inactivation efficacy for bacteria was as follows: Escherichia coli, 5·45 vs. ≥9·22; Staphylococcus aureus, 4·26 vs. ≥10·11; and Bacillus subtilis, 5·09 vs. ≥7·74. Postinactivation bacterial growth in platelets inoculated with a low titre of S. aureus or B. subtilis was detected only with Mirasol. Pathogen inactivation efficacy of Intercept for enveloped viruses was found to be satisfactory. Mirasol showed satisfactory inactivation efficacy for HIV-1 only. The two selected non-enveloped viruses were not inactivated by both systems. Inactivation efficacy of Intercept was more robust for all bacteria tested at high or low titres. © 2014 International Society of Blood Transfusion.

  11. The hybrid methylene blue-zeolite system: a higher efficient photo catalyst for photo inactivation of pathogenic microorganisms

    International Nuclear Information System (INIS)

    Smolinska, M.; Cik, G.; Sersen, F.; Caplovicova, M.; Takacova, A.; Kopani, M.

    2015-01-01

    The composite system can be prepared by incorporation of methylene blue into the channels of zeolite and by adsorption on the surface of the crystals. The composite photo sensitizer effectively absorbs the red light (kmax = 648 nm) and upon illumination with light-emitting diode at a fluence rate of 1.02 mW cm-2 generates effectively reactive singlet oxygen in aqueous solution, which was proved by EPR spectroscopy. To test efficiency for inactivation of pathogenic microorganisms, we measured photo killing of bacteria Escherichia coli and Staphylococcus aureus and yeasts Candida albicans. We found out that after the microorganisms have been adsorbed at the surface of such modified zeolite, the photo generated singlet oxygen quickly penetrates their cell walls, bringing about their effective photo inactivation. The growth inhibition reached almost 50 % at 200 and 400 mg modified zeolite in 1 ml of medium in E. coli and C. albicans, respectively. On the other hand, the growth inhibition of S. aureus reached 50 % at far smaller amount of photo catalyst (30 lg per 1 ml of medium). These results demonstrate differences in sensitivities of bacteria and yeast growth. The comparison revealed that concentration required for IC50 was in case of C. albicans several orders of magnitude lower for a zeolite-immobilized dye than it was for a freely dissolved dye. In S. aureus, this concentration was even lower by four orders of magnitude. Thus, our work suggested a new possibility to exploitation of zeolite and methylene blue in the protection of biologically contaminated environment, and in photodynamic therapy.

  12. Inactivation of pathogenic bacteria inoculated onto a Bacto™ agar model surface using TiO2-UVC photocatalysis, UVC and chlorine treatments.

    Science.gov (United States)

    Yoo, S; Ghafoor, K; Kim, S; Sun, Y W; Kim, J U; Yang, K; Lee, D-U; Shahbaz, H M; Park, J

    2015-09-01

    The aim of this study was to study inactivation of different pathogenic bacteria on agar model surface using TiO2-UV photocatalysis (TUVP). A unified food surface model was simulated using Bacto(™) agar, a routinely used microbial medium. The foodborne pathogenic bacteria Escherichia coli K12 (as a surrogate for E. coli O157:H7), Salmonella Typhimurium, Staphylococcus aureus and Listeria monocytogenes were inoculated onto the agar surface, followed by investigation of TUVP-assisted inactivation and morphological changes in bacterial cells. The TUVP process showed higher bacterial inactivation, particularly for Gram-negative bacteria, than UVC alone and a control (dark reaction). A TUVP treatment of 17·2 mW cm(-2) (30% lower than the UVC light intensity) reduced the microbial load on the agar surface by 4·5-6·0 log CFU cm(-2). UVC treatment of 23·7 mW cm(-2) caused 3·0-5·3 log CFU cm(-2) reduction. The use of agar model surface is effective for investigation of bacterial disinfection and TUVP is a promising nonthermal technique. The results showing effects of photocatalysis and other treatments for inactivation of bacterial pathogens on model surface can be useful for applying such processes for disinfection of fruit, vegetables and other similar surfaces. © 2015 The Society for Applied Microbiology.

  13. Pulsed electric field processing of different fruit juices: impact of pH and temperature on inactivation of spoilage and pathogenic micro-organisms.

    Science.gov (United States)

    Timmermans, R A H; Nierop Groot, M N; Nederhoff, A L; van Boekel, M A J S; Matser, A M; Mastwijk, H C

    2014-03-03

    Pulsed electrical field (PEF) technology can be used for the inactivation of micro-organisms and therefore for preservation of food products. It is a mild technology compared to thermal pasteurization because a lower temperature is used during processing, leading to a better retention of the quality. In this study, pathogenic and spoilage micro-organisms relevant in refrigerated fruit juices were studied to determine the impact of process parameters and juice composition on the effectiveness of the PEF process to inactivate the micro-organisms. Experiments were performed using a continuous-flow PEF system at an electrical field strength of 20 kV/cm with variable frequencies to evaluate the inactivation of Salmonella Panama, Escherichia coli, Listeria monocytogenes and Saccharomyces cerevisiae in apple, orange and watermelon juices. Kinetic data showed that under the same conditions, S. cerevisiae was the most sensitive micro-organism, followed by S. Panama and E. coli, which displayed comparable inactivation kinetics. L. monocytogenes was the most resistant micro-organism towards the treatment conditions tested. A synergistic effect between temperature and electric pulses was observed at inlet temperatures above 35 °C, hence less energy for inactivation was required at higher temperatures. Different juice matrices resulted in a different degree of inactivation, predominantly determined by pH. The survival curves were nonlinear and could satisfactorily be modeled with the Weibull model. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Quantification of pathogen inactivation efficacy by free chlorine disinfection of drinking water for QMRA.

    Science.gov (United States)

    Petterson, S R; Stenström, T A

    2015-09-01

    To support the implementation of quantitative microbial risk assessment (QMRA) for managing infectious risks associated with drinking water systems, a simple modeling approach for quantifying Log10 reduction across a free chlorine disinfection contactor was developed. The study was undertaken in three stages: firstly, review of the laboratory studies published in the literature; secondly, development of a conceptual approach to apply the laboratory studies to full-scale conditions; and finally implementation of the calculations for a hypothetical case study system. The developed model explicitly accounted for variability in residence time and pathogen specific chlorine sensitivity. Survival functions were constructed for a range of pathogens relying on the upper bound of the reported data transformed to a common metric. The application of the model within a hypothetical case study demonstrated the importance of accounting for variable residence time in QMRA. While the overall Log10 reduction may appear high, small parcels of water with short residence time can compromise the overall performance of the barrier. While theoretically simple, the approach presented is of great value for undertaking an initial assessment of a full-scale disinfection contactor based on limited site-specific information.

  15. Peracetic Acid (PAA Disinfection: Inactivation of Microbial Indicators and Pathogenic Bacteria in a Municipal Wastewater Plant

    Directory of Open Access Journals (Sweden)

    Silvia Bonetta

    2017-06-01

    Full Text Available Several studies have noted that treated and untreated wastewaters are primary contributors of a variety of pathogenic microorganisms to the aquatic ecosystem. Conventional wastewater treatment may not be sufficient to achieve microbiologically safe effluent to be discharged into natural waters or reused, thus requiring wastewater effluents to be disinfected. In recent years, peracetic acid (PAA has been adopted as a disinfectant for wastewater effluents. The aim of this study was to evaluate the disinfection efficiency of PAA at low doses (range 0.99–2.10 mg/L against microbial indicators and pathogenic bacteria in a municipal wastewater plant. Samples of untreated sewage and effluents before and after PAA treatment were collected seasonally for 1 year and were analysed for pathogenic Campylobacter, Salmonella spp., E. coli O157:H7 and E. coli virulence genes using molecular methods; moreover, the detection of specific microbial indicators (E. coli, faecal coliforms, enterococci, C. perfringens and Salmonella spp. were carried out using culturing methods. Salmonella spp. DNA was found in all untreated sewage and effluent before PAA treatment, whereas it was recovered in 50% of the samples collected after PAA treatment. Although E. coli O157:H7 was never identified, the occurrence of Shiga-like toxin I amplicons was identified in 75% of the untreated sewage samples, in 50% of the effluents assayed before PAA treatment, and in 25% of the effluents assayed after PAA treatment, whereas the stx2 gene was never found. Campylobacter coli was only detected in one effluent sample before PAA treatment. In the effluents after PAA treatment, a lower load of indicator bacteria was observed compared to the effluents before treatment. The results of this study highlight that the use of low doses of PAA seems to lead to an improvement of the microbiological quality of the effluent, although it is not sufficient to guarantee its suitability for irrigation

  16. Combination treatment of chlorine dioxide gas and aerosolized sanitizer for inactivating foodborne pathogens on spinach leaves and tomatoes.

    Science.gov (United States)

    Park, Sang-Hyun; Kang, Dong-Hyun

    2015-08-17

    The objective of this study was to evaluate the antimicrobial effect of chlorine dioxide (ClO2) gas and aerosolized sanitizer, when applied alone or in combination, on the survival of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes inoculated onto spinach leaves and tomato surfaces. Spinach leaves and tomatoes were inoculated with a cocktail of three strains each of the three foodborne pathogens. ClO2 gas (5 or 10 ppmv) and aerosolized peracetic acid (PAA) (80 ppm) were applied alone or in combination for 20 min. Exposure to 10 ppmv of ClO2 gas for 20 min resulted in 3.4, 3.3, and 3.4 log reductions of E. coli O157:H7, S. Typhimurium, and L. monocytogenes on spinach leaves, respectively. Treatment with 80 ppm of aerosolized PAA for 20 min caused 2.3, 1.9, and 0.8 log reductions of E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively. Combined treatment of ClO2 gas (10 ppmv) and aerosolized PAA (80 ppm) for 20 min caused 5.4, 5.1, and 4.1 log reductions of E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively. E. coli O157:H7, S. Typhimurium, and L. monocytogenes on tomatoes experienced similar reduction patterns to those on spinach leaves. As treatment time increased, most combinations of ClO2 gas and aerosolized PAA showed additive effects in the inactivation of the three pathogens. Combined treatment of ClO2 gas and aerosolized PAA produced injured cells of three pathogens on spinach leaves while generally did not produce injured cells of these pathogens on tomatoes. Combined treatment of ClO2 gas (10 ppmv) and aerosolized PAA (80 ppm) did not significantly (p>0.05) affect the color and texture of samples during 7 days of storage. Copyright © 2015. Published by Elsevier B.V.

  17. Blood-Borne Markers of Fatigue in Competitive Athletes - Results from Simulated Training Camps.

    Directory of Open Access Journals (Sweden)

    Anne Hecksteden

    Full Text Available Assessing current fatigue of athletes to fine-tune training prescriptions is a critical task in competitive sports. Blood-borne surrogate markers are widely used despite the scarcity of validation trials with representative subjects and interventions. Moreover, differences between training modes and disciplines (e.g. due to differences in eccentric force production or calorie turnover have rarely been studied within a consistent design. Therefore, we investigated blood-borne fatigue markers during and after discipline-specific simulated training camps. A comprehensive panel of blood-born indicators was measured in 73 competitive athletes (28 cyclists, 22 team sports, 23 strength at 3 time-points: after a run-in resting phase (d 1, after a 6-day induction of fatigue (d 8 and following a subsequent 2-day recovery period (d 11. Venous blood samples were collected between 8 and 10 a.m. Courses of blood-borne indicators are considered as fatigue dependent if a significant deviation from baseline is present at day 8 (Δfatigue which significantly regresses towards baseline until day 11 (Δrecovery. With cycling, a fatigue dependent course was observed for creatine kinase (CK; Δfatigue 54±84 U/l; Δrecovery -60±83 U/l, urea (Δfatigue 11±9 mg/dl; Δrecovery -10±10 mg/dl, free testosterone (Δfatigue -1.3±2.1 pg/ml; Δrecovery 0.8±1.5 pg/ml and insulin linke growth factor 1 (IGF-1; Δfatigue -56±28 ng/ml; Δrecovery 53±29 ng/ml. For urea and IGF-1 95% confidence intervals for days 1 and 11 did not overlap with day 8. With strength and high-intensity interval training, respectively, fatigue-dependent courses and separated 95% confidence intervals were present for CK (strength: Δfatigue 582±649 U/l; Δrecovery -618±419 U/l; HIIT: Δfatigue 863±952 U/l; Δrecovery -741±842 U/l only. These results indicate that, within a comprehensive panel of blood-borne markers, changes in fatigue are most accurately reflected by urea and IGF-1 for cycling

  18. Blood-Borne Markers of Fatigue in Competitive Athletes – Results from Simulated Training Camps

    Science.gov (United States)

    Hecksteden, Anne; Skorski, Sabrina; Schwindling, Sascha; Hammes, Daniel; Pfeiffer, Mark; Kellmann, Michael; Ferrauti, Alexander; Meyer, Tim

    2016-01-01

    Assessing current fatigue of athletes to fine-tune training prescriptions is a critical task in competitive sports. Blood-borne surrogate markers are widely used despite the scarcity of validation trials with representative subjects and interventions. Moreover, differences between training modes and disciplines (e.g. due to differences in eccentric force production or calorie turnover) have rarely been studied within a consistent design. Therefore, we investigated blood-borne fatigue markers during and after discipline-specific simulated training camps. A comprehensive panel of blood-born indicators was measured in 73 competitive athletes (28 cyclists, 22 team sports, 23 strength) at 3 time-points: after a run-in resting phase (d 1), after a 6-day induction of fatigue (d 8) and following a subsequent 2-day recovery period (d 11). Venous blood samples were collected between 8 and 10 a.m. Courses of blood-borne indicators are considered as fatigue dependent if a significant deviation from baseline is present at day 8 (Δfatigue) which significantly regresses towards baseline until day 11 (Δrecovery). With cycling, a fatigue dependent course was observed for creatine kinase (CK; Δfatigue 54±84 U/l; Δrecovery -60±83 U/l), urea (Δfatigue 11±9 mg/dl; Δrecovery -10±10 mg/dl), free testosterone (Δfatigue -1.3±2.1 pg/ml; Δrecovery 0.8±1.5 pg/ml) and insulin linke growth factor 1 (IGF-1; Δfatigue -56±28 ng/ml; Δrecovery 53±29 ng/ml). For urea and IGF-1 95% confidence intervals for days 1 and 11 did not overlap with day 8. With strength and high-intensity interval training, respectively, fatigue-dependent courses and separated 95% confidence intervals were present for CK (strength: Δfatigue 582±649 U/l; Δrecovery -618±419 U/l; HIIT: Δfatigue 863±952 U/l; Δrecovery -741±842 U/l) only. These results indicate that, within a comprehensive panel of blood-borne markers, changes in fatigue are most accurately reflected by urea and IGF-1 for cycling and by CK

  19. Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

    Science.gov (United States)

    Fallah, Aziz A.; Siavash Saei-Dehkordi, S.; Rahnama, Mohammad

    2010-10-01

    Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 °C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D10 values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

  20. Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

    International Nuclear Information System (INIS)

    Fallah, Aziz A.; Siavash Saei-Dehkordi, S.; Rahnama, Mohammad

    2010-01-01

    Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 o C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D 10 values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

  1. Pathogen inactivation by riboflavin and ultraviolet light illumination accelerates the red blood cell storage lesion and promotes eryptosis.

    Science.gov (United States)

    Qadri, Syed M; Chen, Deborah; Schubert, Peter; Perruzza, Darian L; Bhakta, Varsha; Devine, Dana V; Sheffield, William P

    2017-03-01

    Pathogen reduction treatment using riboflavin and ultraviolet light illumination (Mirasol) effectively reduces the risk of transfusion-transmitted infections. This treatment is currently licensed for only platelets and plasma products, while its application to whole blood (WB) to generate pathogen-inactivated red blood cells (RBCs) is under development. RBC storage lesion, constituting numerous morphologic and biochemical changes, influences RBC quality and limits shelf life. Stored RBCs further show enhanced susceptibility to RBC programmed cell death (eryptosis) characterized by increased cytosolic Ca 2+ -provoked membrane phosphatidylserine (PS) externalization. Using a "pool-and-split" approach, we examined multiple variables of RBC storage lesion and eryptosis in RBC units, derived from Mirasol-treated or untreated WB, after 4 to 42 days of storage, under blood bank conditions. In comparison to untreated RBC units, Mirasol treatment significantly altered membrane microvesiculation, supernatant hemoglobin, osmotic fragility, and intracellular adenosine triphosphate levels but did not influence membrane CD47 expression and 2,3-diphosphoglycerate levels. Mirasol-treated RBCs showed significantly higher PS exposure after 42, but not after not more than 21, days of storage, which was accompanied by enhanced cytosolic Ca 2+ activity, ceramide abundance, and oxidative stress, but not p38 kinase activation. Mirasol treatment significantly augmented PS exposure, Ca 2+ entry, and protein kinase C activation after energy depletion, a pathophysiologic cell stressor. Mirasol-treated RBCs were, however, more resistant to cell shrinkage. Prolonged storage of Mirasol-treated RBCs significantly increases the proportion of eryptotic RBCs, while even short-term storage enhances the susceptibility of RBCs to stress-induced eryptosis, which could reduce posttransfusion RBC recovery in patients. © 2016 AABB.

  2. Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

    Energy Technology Data Exchange (ETDEWEB)

    Fallah, Aziz A., E-mail: a_a_falah@yahoo.co [Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Research Institute of Zoonotic Diseases, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Siavash Saei-Dehkordi, S. [Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Research Institute of Zoonotic Diseases, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Rahnama, Mohammad [Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Zabol, Zabol 98615 (Iran, Islamic Republic of)

    2010-10-15

    Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 {sup o}C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D{sub 10} values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

  3. Effect of low temperature thermal pre-treatment on the solubilization of organic matter, pathogen inactivation and mesophilic anaerobic digestion of poultry sludge.

    Science.gov (United States)

    Ruiz-Espinoza, Juan E; Méndez-Contreras, Juan M; Alvarado-Lassman, Alejandro; Martínez-Delgadillo, Sergio A

    2012-01-01

    Treatment of poultry industry effluents produces wastewater sludge with high levels of organic compounds and pathogenic microorganisms. In this research, the thermal pre-treatment of poultry slaughterhouse sludge (PSS) was evaluated for low temperatures in combination with different exposure times as a pre-hydrolysis strategy to improve the anaerobic digestion process. Organic compounds solubilization and inactivation of pathogenic microorganisms were evaluated after treatment at 70, 80 or 90°C for 30, 60 or 90 min. The results showed that 90°C and 90 min were the most efficient conditions for solubilization of the organic compounds (10%). In addition, the bacteria populations and the more resistant structures, such as helminth eggs (HE), were completely inactivated. Finally, the thermal pre-treatment applied to the sludge increased methane yield by 52% and reduced hydraulic retention time (HRT) by 52%.

  4. Pathogen inactivation in fresh frozen plasma using riboflavin and ultraviolet light: Effects on plasma proteins and coagulation factor VIII

    Directory of Open Access Journals (Sweden)

    Stanojković Zoran

    2011-01-01

    Full Text Available Background/Aim. Riboflavin (vitamin B2 activated by ultraviolet (UV light, produces active oxygen which damages cell membrane and prevents replication of the carrier of diseases (viruses, bacteria, protozoa in all blood products. The aim of this study was to establish the influence of the process of photo inactivation in pathogens using riboflavin and UV rays on the concentration of coagulation factor VIII:C (FVIII:C and proteins in plasma that were treated before freezing. Methods. The examination included 20 units of plasma, separated from whole blood donated by voluntary blood donors around 6 hours from the moment of collection. The units were pooled and separated in to two groups: one consisted of 10 control units and the other of 10 experimental units. Experimental units of the plasma were treated by riboflavin (35 mL and UV rays (6.24 J/mL, 265-370 nm on Mirasol aparature (Caridian BCT Biotechnologies, USA in approximate duration of 6 minutes. Furthermore, 35 mL of saline solution was added to the control plasma. One sample for examining was taken from the control plasma (KG and two residual were taken from experimental plasma after the addition of riboflavin either before (EG1 or post illumination (EG2. Results. Comparing the mean values of FVIII:C (% we noticed statistically significantly higher level in the EG1 group than in the EG2 group (65.00 ± 4.52 vs 63.20 ± 4.73; t = 4.323, p = 0.002, while between the KG and experimental groups (EG1 and EG2 there was no statistically significant difference in the concentration of FVIII:C. There was a statistically significant decrease of albumin concentration (g/L in the EG2 group comparing to the KG (33.35 ± 0.94 vs 31.94 ± 0.84; t = 3.534, p = 0.002, but there was no mentioned difference in albumin concentration between the KG and the EG1, so as between the EG1 and the EG2. Conclusion. Plasma inactivated by riboflavin and UV rays (Mirasol PRT sistem, Caridian BCT, USA keeps all the

  5. Blood-borne biomarkers of mortality risk: systematic review of cohort studies.

    Directory of Open Access Journals (Sweden)

    Evelyn Barron

    Full Text Available Lifespan and the proportion of older people in the population are increasing, with far reaching consequences for the social, political and economic landscape. Unless accompanied by an increase in health span, increases in age-related diseases will increase the burden on health care resources. Intervention studies to enhance healthy ageing need appropriate outcome measures, such as blood-borne biomarkers, which are easily obtainable, cost-effective, and widely accepted. To date there have been no systematic reviews of blood-borne biomarkers of mortality.To conduct a systematic review to identify available blood-borne biomarkers of mortality that can be used to predict healthy ageing post-retirement.Four databases (Medline, Embase, Scopus, Web of Science were searched. We included prospective cohort studies with a minimum of two years follow up and data available for participants with a mean age of 50 to 75 years at baseline.From a total of 11,555 studies identified in initial searches, 23 fulfilled the inclusion criteria. Fifty-one blood borne biomarkers potentially predictive of mortality risk were identified. In total, 20 biomarkers were associated with mortality risk. Meta-analyses of mortality risk showed significant associations with C-reactive protein (Hazard ratios for all-cause mortality 1.42, p<0.001; Cancer-mortality 1.62, p<0.009; CVD-mortality 1.31, p = 0.033, N Terminal-pro brain natriuretic peptide (Hazard ratios for all-cause mortality 1.43, p<0.001; CHD-mortality 1.58, p<0.001; CVD-mortality 1.67, p<0.001 and white blood cell count (Hazard ratios for all-cause mortality 1.36, p = 0.001. There was also evidence that brain natriuretic peptide, cholesterol fractions, erythrocyte sedimentation rate, fibrinogen, granulocytes, homocysteine, intercellular adhesion molecule-1, neutrophils, osteoprotegerin, procollagen type III aminoterminal peptide, serum uric acid, soluble urokinase plasminogen activator receptor, tissue inhibitor of

  6. Iatrogenic blood-borne viral infections in refugee children from war and transition zones.

    Science.gov (United States)

    Goldwater, Paul N

    2013-06-01

    Pediatric infectious disease clinicians in industrialized countries may encounter iatrogenically transmitted HIV, hepatitis B virus, and hepatitis C virus infections in refugee children from Central Asia, Southeast Asia, and sub-Saharan Africa. The consequences of political collapse and/or civil war-work migration, prostitution, intravenous drug use, defective public health resources, and poor access to good medical care-all contribute to the spread of blood-borne viruses. Inadequate infection control practices by medical establishments can lead to iatrogenic infection of children. Summaries of 4 cases in refugee children in Australia are a salient reminder of this problem.

  7. The location of splenic NKT cells favours their rapid activation by blood-borne antigen

    Science.gov (United States)

    Barral, Patricia; Sánchez-Niño, María Dolores; van Rooijen, Nico; Cerundolo, Vincenzo; Batista, Facundo D

    2012-01-01

    Natural killer T (NKT) cells play an important role in mounting protective responses to blood-borne infections. However, though the spleen is the largest blood filter in the body, the distribution and dynamics of NKT cells within this organ are not well characterized. Here we show that the majority of NKT cells patrol around the marginal zone (MZ) and red pulp (RP) of the spleen. In response to lipid antigen, these NKT cells become arrested and rapidly produce cytokines, while the small proportion of NKT cells located in the white pulp (WP) exhibit limited activation. Importantly, disruption of the splenic MZ by chemical or genetic approaches results in a severe reduction in NKT cell activation indicating the need of cooperation between both MZ macrophages and dendritic cells for efficient NKT cell responses. Thus, the location of splenic NKT cells in the MZ and RP facilitates their access to blood-borne antigen and enables the rapid initiation of protective immune responses. PMID:22505026

  8. Heparin induced alterations in clearance and distribution of blood-borne microparticles following operative trauma.

    Science.gov (United States)

    Saba, T M; Antikatzides, T G

    1979-04-01

    The influence of systemic heparin administration on the vascular clearance and tissue distribution of blood-borne microparticles was evaluated in normal rats and rats after operation (laparotomy plus intestinal manipulation) utilizing an (131)I- colloid which is phagocytized by the reticuloendothelial system (RES). Intravenous heparin administration (100 USP/100g body weight) into normal animals three minutes prior to colloid injection (50 mg/lOOg) induced a significant increase in pulmonary localization of the microparticles as compared to nonheparinized control rats, while hepatic and splenic uptake were decreased. Surgical trauma decreased hepatic RE uptake and increased pulmonary localization of the microparticles when injected systemically at 60 minutes postsurgery. Heparin administration 60 minutes after surgery and three minutes prior to colloid injection, magnified the increased pulmonary localization response with an associated further depression of the RES. The ability of heparin to alter both RE clearance function and lung localization of microparticles was dose dependent and a function of the interval between heparin administration and systemic particulate infusion. Thus, low dose heparin administration was capable of stimulating RE activity while heparin in doses of excess of 50 USP units/lOOg body weight decreased RE function. These findings suggest that the functional state of the hepatic RE system can be greatly affected in a dose-dependent manner by systemic heparin administration which may influence distribution of blood-borne microparticles.

  9. Outcome of Accidental Exposure Prone to Blood Borne Viral Infections in an Educational Hospital

    Directory of Open Access Journals (Sweden)

    Shahnaz Sali

    2016-04-01

    Full Text Available Background: The risk for transmission of blood-borne viruses (BBVs such as Human immunodeficiency virus (HIV, hepatitis B virus (HBV and hepatitis C virus (HCV due to occupational exposure is a major concern in the health care setting.Materials and Methods: This study among 337 health care workers (HCWs accidentally exposed to BBVs was carried out from January 2009 to March 2015. The data were reviewed in labbafinejhad hospital, Tehran, Iran.Results: 4 HCWs had exposure to HBS Ag positive, which HBS antibody titer of them was higher than 10 mlu/ml, 6 HCWs were exposed to HCV seropositive patients underwent laboratory investigations for  HCV-antibody on 4,12, 24 weeks that results were negative. 3 cases had exposure to HIV seropositive patients which received standard antiretroviral post exposure prophylaxis.Conclusion: Timely performance for PEP (Post Exposure Prophylaxis reducing BBVs transmission among HCWs.prophylaxis. Conclusions: Timely performance for  PEP(Post Exposure Prophylaxis reducing BBVs transmission among HCWs.Key words: Outcome; Accidental Exposure; Blood Borne Viral Infections

  10. Pasteurization of milk: the heat inactivation kinetics of milk-borne dairy pathogens under commercial-type conditions of turbulent flow.

    Science.gov (United States)

    Pearce, L E; Smythe, B W; Crawford, R A; Oakley, E; Hathaway, S C; Shepherd, J M

    2012-01-01

    This is the first study to report kinetic data on the survival of a range of significant milk-borne pathogens under commercial-type pasteurization conditions. The most heat-resistant strain of each of the milk-borne pathogens Staphylococcus aureus, Yersinia enterocolitica, pathogenic Escherichia coli, Cronobacter sakazakii (formerly known as Enterobacter sakazakii), Listeria monocytogenes, and Salmonella was selected to obtain the worst-case scenario in heat inactivation trials using a pilot-plant-scale pasteurizer. Initially, approximately 30 of each species were screened using a submerged coil unit. Then, UHT milk was inoculated with the most heat-resistant pathogens at ~10(7)/mL and heat treated in a pilot-plant-scale pasteurizer under commercial-type conditions of turbulent flow for 15s over a temperature range from 56 to 66°C and at 72°C. Survivors were enumerated on nonselective media chosen for the highest efficiency of plating of heat-damaged bacteria of each of the chosen strains. The mean log(10) reductions and temperatures of inactivation of the 6 pathogens during a 15-s treatment were Staph. aureus >6.7 at 66.5°C, Y. enterocolitica >6.8 at 62.5°C, pathogenic E. coli >6.8 at 65°C, C. sakazakii >6.7 at 67.5°C, L. monocytogenes >6.9 at 65.5°C, and Salmonella ser. Typhimurium >6.9 at 61.5°C. The kinetic data from these experiments will be used by the New Zealand Ministry of Agriculture and Forestry to populate the quantitative risk assessment model being developed to investigate the risks to New Zealand consumers from pasteurized, compared with nonpasteurized, milk and milk products. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Comparison of the disinfection efficacy of chlorine-based products for inactivation of viral indicators and pathogenic bacteria in produce wash water.

    Science.gov (United States)

    Chaidez, Cristobal; Moreno, Maria; Rubio, Werner; Angulo, Miguel; Valdez, Benigno

    2003-09-01

    Outbreaks of pathogenic bacteria infections associated with the consumption of fresh produce has occurred with increased frequency in recent years. This study was undertaken to determine the efficacy of three commonly used disinfectants in packing-houses of Culiacan, Mexico (sodium hypochlorite [NaOCl], trichlor-s-triazinetrione [TST] and thrichlormelamine [TCM]) for inactivation of viral indicators and pathogenic bacteria inoculated onto produce wash water. Each microbial challenge consisted of 2 L of water containing approximately 8 log10 bacterial CFU ml(-1), and 8 log10 viral PFU ml(-1) treated with 100 and 300 mg l(-1) of total chlorine with modified turbidity. Water samples were taken after 2 min of contact with chlorine-based products and assayed for the particular microorganisms. TST and NaOCl were found to effectively reduce for bacterial pathogens and viral indicators 8 log10 and 7 log10, respectively (alpha=0.05). The highest inactivation rate was observed when the turbidity was low and the disinfectant was applied at 300 mg l(-1). TCM did not show effective results when compared with the TST and NaOCl (Pturbidity created by the organic and inorganic material present in the water tanks carried by the fresh produce may affect the efficacy of the chlorine-based products.

  12. Investigation of critical inter-related factors affecting the efficacy of pulsed light for inactivating clinically relevant bacterial pathogens.

    Science.gov (United States)

    Farrell, H P; Garvey, M; Cormican, M; Laffey, J G; Rowan, N J

    2010-05-01

    To investigate critical electrical and biological factors governing the efficacy of pulsed light (PL) for the in vitro inactivation of bacteria isolated from the clinical environment. Development of this alternative PL decontamination approach is timely, as the incidence of health care-related infections remains unacceptably high. Predetermined cell numbers of clinically relevant Gram-positive and Gram-negative bacteria were inoculated separately on agar plates and were flashed with lamp discharge energy (range 3.2-20 J per pulse), the amount of pulsing applied (range 0-60 pulses) and the distance between light source and treatment surface (range 8-20 cm) used. Greater decontamination levels were achieved using a combination of higher lamp discharge energies, increased number of pulses and shorter distances between treatment surface and the xenon light source. Levels of microbial sensitivity also varied depending on the population type, size and age of cultures treated. Production of pigment pyocynanin and alginate slime in mucoid strains of Pseudomonas aeruginosa afforded some protection against lethal action of PL; however, this was evident only by using a combination of reduced amount of pulsing at the lower lamp discharge energies tested. A clear pattern was observed where Gram-positive bacterial pathogens were more resistant to cidal effects of PL compared to Gram negatives. While negligible photoreactivation of PL-treated bacterial strains occurred after full pulsing regimes at the different lamp discharge energies tested, some repair was evident when using a combination of reduced pulsing at the lower lamp discharge energies. Strains harbouring genes for multiple resistances to antibiotics were not significantly more resistant to PL treatments. Slight temperature rises (lamp discharge energies. Presence of organic matter on treatment surface did not significantly affect PL decontamination efficacy, nor did growth of PL-treated bacteria on selective agar

  13. Syringe access for the prevention of blood borne infections among injection drug users

    Directory of Open Access Journals (Sweden)

    Rich Josiah D

    2003-11-01

    Full Text Available Abstract Background Approximately one-third of acquired immunodeficiency syndrome cases in the United States are associated with the practice of sharing of injection equipment and are preventable through the once-only use of syringes, needles and other injection equipment. Discussion Sterile syringes may be obtained legally by 4 methods depending on the state. They may be purchased over the counter, prescribed, obtained at syringe exchange programs or furnished by authorized agencies. Each of these avenues has advantages and disadvantages; therefore, legal access through all means is the most likely way to promote the use of sterile syringes. Summary By assisting illicit drug injectors to obtain sterile syringes the primary care provider is able to reduce the incidence of blood borne infections, and educate patients about safe syringe disposal. The provider is also able to initiate discussion about drug use in a nonjudgmental manner and to offer care to patients who are not yet ready to consider drug treatment.

  14. Psychometric properties of the Blood-borne Virus Transmission Risk Assessment Questionnaire (BBV-TRAQ).

    Science.gov (United States)

    Fry, Craig L; Lintzeris, Nick

    2003-02-01

    To develop a standard measure of blood-borne virus transmission risk behaviour, and examine the underlying psychometric properties. The Blood-borne Virus Transmission Risk Assessment Questionnaire (BBV-TRAQ) was developed over three consecutive phases of the original BBV-TRAQ study in adherence to classical scale development procedures, culminating in the recruitment of a development sample of current injecting drug users via convenience and snowball sampling. Needle and syringe programmes (NSPs), medical clinics, alcohol/drug agencies, peer-based and outreach organizations across inner and outer metropolitan Melbourne. Two hundred and nine current injecting drug users. The mean age was 27 years, 68% were male, 65% unemployed, 36% with prison history and 25% in methadone maintenance. BBV-TRAQ items cover specific injecting, sexual and skin penetration risk practices. BBV-TRAQ characteristics were assessed via measures of internal and test-retest reliability; collateral validation; and principal components analyses. The BBV-TRAQ has satisfactory psychometric properties. Internal (a=0.87), test-retest (r=0.84) and inter-observer reliability results were high, suggesting that the instrument provides a reliable measure of BBV risk behaviour and is reliable over time and across interviewers. A principal components analysis with varimax rotation produced a parsimonious factor solution despite modest communality, and indicated that three factors (injecting, sex and skin penetration/hygiene risks) are required to describe BBV risk behaviour. The BBV-TRAQ is reliable and represents the first risk assessment tool to incorporate sufficient coverage of injecting, sex and other skin penetration risk practices to be considered truly content valid. The questionnaire is indicated for use in addictions research, clinical, peer education and BBV risk behaviour surveillance settings.

  15. Thermal inactivation of H5N2 high-pathogenicity avian influenza virus in dried egg white with 7.5% moisture.

    Science.gov (United States)

    Thomas, Colleen; Swayne, David E

    2009-09-01

    High-pathogenicity avian influenza viruses (HPAIV) cause severe systemic disease with high mortality in chickens. Isolation of HPAIV from the internal contents of chicken eggs has been reported, and this is cause for concern because HPAIV can be spread by movement of poultry products during marketing and trade activity. This study presents thermal inactivation data for the HPAIV strain A/chicken/PA/1370/83 (H5N2) (PA/83) in dried egg white with a moisture content (7.5%) similar to that found in commercially available spray-dried egg white products. The 95% upper confidence limits for D-values calculated from linear regression of the survival curves at 54.4, 60.0, 65.5, and 71.1 degrees C were 475.4, 192.2, 141.0, and 50.1 min, respectively. The line equation y = [0.05494 x degrees C] + 5.5693 (root mean square error = 0.0711) was obtained by linear regression of experimental D-values versus temperature. Conservative predictions based on the thermal inactivation data suggest that standard industry pasteurization protocols would be very effective for HPAIV inactivation in dried egg white. For example, these calculations predict that a 7-log reduction would take only 2.6 days at 54.4 degrees C.

  16. Standardization of an inactivated H17N1 avian influenza vaccine and efficacy against A/Chicken/Italy/13474/99 high-pathogenicity virus infection.

    Science.gov (United States)

    Di Trani, L; Cordioli, P; Falcone, E; Lombardi, G; Moreno, A; Sala, G; Tollis, M

    2003-01-01

    The minimum requirements for assessing the immunogenicity of an experimental avian influenza (AI) vaccine prepared from inactivated A/Turkey/Italy/2676/99 (H7N1) low-pathogenicity (LP) AI (LPAI) virus were determined in chickens of different ages. A correlation between the amount of hemagglutinin (HA) per dose of vaccine and the protection against clinical signs of disease and infection by A/Chicken/Italy/13474/99 highly pathogenic (HP) AI (HPAI) virus was established. Depending on the vaccination schedule, one or two administrations of 0.5 microg of hemagglutinin protected chickens against clinical signs and death and completely prevented virus shedding from birds challenged at different times after vaccination.

  17. Transfusion of pooled buffy coat platelet components prepared with photochemical pathogen inactivation treatment: the euroSPRITE trial

    NARCIS (Netherlands)

    D.J. van Rhenen (Dirk Jan); S. Marblie (Stephane); M. Laforet (Michel); K. Davis (Kathryn); M. Conlan (Maureen); B. Lioure (Bruno); H. Gulliksson (Hans); J.P. Cazenave; P. Metzel (Peyton); D. Pamphilon (Derwood); L. Corash (Laurence); J. Flament (Jocelyne); P. Ljungman (Per); H. Kluter; H. Vermeij (Hans); V. Mayaudon (Veronique); L. Lin (Lily); M.C. Kappers-Klunne (Mies); D. Buchholz (Don); G.E. de Greef (Georgine)

    2003-01-01

    textabstractA nucleic acid-targeted photochemical treatment (PCT) using amotosalen HCl (S-59) and ultraviolet A (UVA) light was developed to inactivate viruses, bacteria, protozoa, and leukocytes in platelet components. We conducted a controlled, randomized, double-blinded trial in thrombocytopenic

  18. Inactivation of bacterial pathogenic load in compost against vermicompost of organic solid waste aiming to achieve sanitation goals: A review.

    Science.gov (United States)

    Soobhany, Nuhaa; Mohee, Romeela; Garg, Vinod Kumar

    2017-06-01

    Waste management strategies for organic residues, such as composting and vermicomposting, have been implemented in some developed and developing countries to solve the problem of organic solid waste (OSW). Yet, these biological treatment technologies do not always result in good quality compost or vermicompost with regards to sanitation capacity owing to the presence of bacterial pathogenic substances in objectionable concentrations. The presence of pathogens in soil conditioners poses a potential health hazard and their occurrence is of particular significance in composts and/or vermicomposts produced from organic materials. Past and present researches demonstrated a high-degree of agreement that various pathogens survive after the composting of certain OSW but whether similar changes in bacterial pathogenic loads arise during vermitechnology has not been thoroughly elucidated. This review garners information regarding the status of various pathogenic bacteria which survived or diffused after the composting process compared to the status of these pathogens after the vermicomposting of OSW with the aim of achieving sanitation goals. This work is also indispensable for the specification of compost quality guidelines concerning pathogen loads which would be specific to treatment technology. It was hypothesized that vermicomposting process for OSW can be efficacious in sustaining the existence of pathogenic organisms most specifically; human pathogens under safety levels. In summary, earthworms can be regarded as a way of obliterating pathogenic bacteria from OSW in a manner equivalent to earthworm gut transit mechanism which classifies vermicomposting as a promising sanitation technique in comparison to composting processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Individual Patterns in Blood-Borne Indicators of Fatigue-Trait or Chance.

    Science.gov (United States)

    Julian, Ross; Meyer, Tim; Fullagar, Hugh H K; Skorski, Sabrina; Pfeiffer, Mark; Kellmann, Michael; Ferrauti, Alexander; Hecksteden, Anne

    2017-03-01

    Julian, R, Meyer, T, Fullagar, HHK, Skorski, S, Pfeiffer, M, Kellmann, M, Ferrauti, A, and Hecksteden, A. Individual patterns in blood-borne indicators of fatigue-trait or chance. J Strength Cond Res 31(3): 608-619, 2017-Blood-borne markers of fatigue such as creatine kinase (CK) and urea (U) are widely used to fine-tune training recommendations. However, predictive accuracy is low. A possible explanation for this dissatisfactory characteristic is the propensity of athletes to react to different patterns of fatigue indicators (e.g., predominantly muscular [CK] or metabolic [U]). The aim of the present trial was to explore this hypothesis by using repetitive fatigue-recovery cycles. A total of 22 elite junior swimmers and triathletes (18 ± 3 years) were monitored for 9 weeks throughout 2 training phases (low-intensity, high-volume [LIHV] and high-intensity, low-volume [HILV] phases). Blood samples were collected each Monday (recovered) and Friday (fatigued) morning. From measured values of CK, U, free-testosterone (FT), and cortisol (C) as determined in the rested and fatigued state, respectively, Monday-Friday differences (Δ) were calculated and classified by magnitude before calculation of ratios (ΔCK/ΔU and ΔFT/ΔC). Coefficient of variation (CV) was calculated as group-based estimates of reproducibility. Linear mixed modeling was used to differentiate inter- and intraindividual variability. Consistency of patterns was analyzed by comparing with threshold values (1.1 for all weeks). Reproducibility was very low for fatigue-induced changes (CV ≥ 100%) with interindividual variation accounting for 45-60% of overall variability. Case-wise analysis indicated consistent ΔCK/ΔU patterns for 7 individuals in LIHV and 7 in HILV; 5 responded consistently throughout. For ΔFT/ΔC the number of consistent patterns was 2 in LIHV and 3 in HILV. These findings highlight the potential value of an individualized and multivariate approach in the assessment of fatigue.

  20. A multicentre molecular analysis of hepatitis B and blood-borne virus coinfections in Viet Nam.

    Directory of Open Access Journals (Sweden)

    Linda Dunford

    Full Text Available Hepatitis B (HBV infection is endemic in Viet Nam, with up to 8.4 million individuals estimated to be chronically infected. We describe results of a large, multicentre seroepidemiological and molecular study of the prevalence of HBV infection and blood-borne viral coinfections in Viet Nam. Individuals with varying risk factors for infection (n = 8654 were recruited from five centres; Ha Noi, Hai Phong, Da Nang, Khanh Hoa and Can Tho. A mean prevalence rate of 10.7% was observed and levels of HBsAg were significantly higher in injecting drug users (IDUs (17.4%, n = 174/1000 and dialysis patients (14.3%, n = 82/575 than in lower-risk groups (9.4%; p<0.001. Coinfection with HIV was seen in 28% of HBV-infected IDUs (n = 49/174 and 15.2% of commercial sex workers (CSWs; n = 15/99. HCV infection was present in 89.8% of the HBV-HIV coinfected IDUs (n = 44/49 and 40% of HBV-HIV coinfected CSWs (n = 16/40. Anti-HDV was detected in 10.7% (n = 34/318 of HBsAg positive individuals. Phylogenetic analysis of HBV S gene (n = 187 showed a predominance of genotype B4 (82.6%; genotypes C1 (14.6%, B2 (2.7% and C5 (0.5% were also identified. The precore mutation G1896A was identified in 35% of all specimens, and was more frequently observed in genotype B (41% than genotype C (3%; p<0.0001. In the immunodominant 'a' region of the surface gene, point mutations were identified in 31% (n = 58/187 of sequences, and 2.2% (n = 4/187 and 5.3% (n = 10/187 specimens contained the major vaccine escape mutations G145A/R and P120L/Q/S/T, respectively. 368 HBsAg positive individuals were genotyped for the IL28B SNP rs12979860 and no significant association between the IL28B SNP and clearance of HBsAg, HBV viral load or HBeAg was observed. This study confirms the high prevalence of HBV infection in Viet Nam and also highlights the significant levels of blood-borne virus coinfections, which have important implications for hepatitis-related morbidity and development of effective

  1. United Kingdom newsprint media reporting on sexual health and blood-borne viruses in 2010.

    Science.gov (United States)

    Martin, Susan; Hilton, Shona; McDaid, Lisa M

    2013-12-01

    Improving sexual health and blood-borne virus (BBV) outcomes continue to be of high priority within the United Kingdom (UK) and it is evident that the media can and do impact the public health agenda. This paper presents the first large-scale exploration of UK national newsprint media representations of sexual health and BBVs. Using keyword searches in electronic databases, 677 articles published during 2010 were identified from 12 national (UK-wide and Scottish) newspapers. Content analysis was used to identify manifest content and to examine the tone of articles. Although there was a mixed picture overall in terms of tone, negatively toned articles, which focussed on failures or blame, were common, particularly within HIV/AIDS, hepatitis B and C, and other sexually transmissible infection coverage (41% were assessed as containing negative content; 46% had negative headlines). Differences were found by newspaper genre, with 'serious' newspaper articles appearing more positive and informative than 'midmarket' newspapers or 'tabloids'. Across the sample, particular individuals, behaviours and risk groups were focussed on, not always accurately, and there was little mention of deprivation and inequalities (9%). A gender imbalance was evident, particularly within reproductive health articles (71% focussed on women; 23% on men), raising questions concerning gender stereotyping. There is a need to challenge the role that media messages have in the reinforcement of a negative culture around sexual health in the UK and for a strong collective advocacy voice to ensure that future media coverage is positively portrayed.

  2. Imaging tumor hypoxia: Blood-borne delivery of imaging agents is fundamentally different in hypoxia subtypes

    Directory of Open Access Journals (Sweden)

    Peter Vaupel

    2014-03-01

    Full Text Available Hypoxic tissue subvolumes are a hallmark feature of solid malignant tumors, relevant for cancer therapy and patient outcome because they increase both the intrinsic aggressiveness of tumor cells and their resistance to several commonly used anticancer strategies. Pathogenetic mechanisms leading to hypoxia are diverse, may coexist within the same tumor and are commonly grouped according to the duration of their effects. Chronic hypoxia is mainly caused by diffusion limitations resulting from enlarged intercapillary distances and adverse diffusion geometries and — to a lesser extent — by hypoxemia, compromised perfusion or long-lasting microregional flow stops. Conversely, acute hypoxia preferentially results from transient disruptions in perfusion. While each of these features of the tumor microenvironment can contribute to a critical reduction of oxygen availability, the delivery of imaging agents (as well as nutrients and anticancer agents may be compromised or remain unaffected. Thus, a critical appraisal of the effects of the various mechanisms leading to hypoxia with regard to the blood-borne delivery of imaging agents is necessary to judge their ability to correctly represent the hypoxic phenotype of solid malignancies.

  3. Inactivation of Caliciviruses

    Directory of Open Access Journals (Sweden)

    Raymond Nims

    2013-03-01

    Full Text Available The Caliciviridae family of viruses contains clinically important human and animal pathogens, as well as vesivirus 2117, a known contaminant of biopharmaceutical manufacturing processes employing Chinese hamster cells. An extensive literature exists for inactivation of various animal caliciviruses, especially feline calicivirus and murine norovirus. The caliciviruses are susceptible to wet heat inactivation at temperatures in excess of 60 °C with contact times of 30 min or greater, to UV-C inactivation at fluence ≥30 mJ/cm2, to high pressure processing >200 MPa for >5 min at 4 °C, and to certain photodynamic inactivation approaches. The enteric caliciviruses (e.g.; noroviruses display resistance to inactivation by low pH, while the non-enteric species (e.g.; feline calicivirus are much more susceptible. The caliciviruses are inactivated by a variety of chemicals, including alcohols, oxidizing agents, aldehydes, and β-propiolactone. As with inactivation of viruses in general, inactivation of caliciviruses by the various approaches may be matrix-, temperature-, and/or contact time-dependent. The susceptibilities of the caliciviruses to the various physical and chemical inactivation approaches are generally similar to those displayed by other small, non-enveloped viruses, with the exception that the parvoviruses and circoviruses may require higher temperatures for inactivation, while these families appear to be more susceptible to UV-C inactivation than are the caliciviruses.

  4. Efficacy of UV-C irradiation for inactivation of food-borne pathogens on sliced cheese packaged with different types and thicknesses of plastic films.

    Science.gov (United States)

    Ha, Jae-Won; Back, Kyeong-Hwan; Kim, Yoon-Hee; Kang, Dong-Hyun

    2016-08-01

    In this study, the efficacy of using UV-C light to inactivate sliced cheese inoculated with Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes and, packaged with 0.07 mm films of polyethylene terephthalate (PET), polyvinylchloride (PVC), polypropylene (PP), and polyethylene (PE) was investigated. The results show that compared with PET and PVC, PP and PE films showed significantly reduced levels of the three pathogens compared to inoculated but non-treated controls. Therefore, PP and PE films of different thicknesses (0.07 mm, 0.10 mm, and 0.13 mm) were then evaluated for pathogen reduction of inoculated sliced cheese samples. Compared with 0.10 and 0.13 mm, 0.07 mm thick PP and PE films did not show statistically significant reductions compared to non-packaged treated samples. Moreover, there were no statistically significant differences between the efficacy of PP and PE films. These results suggest that adjusted PP or PE film packaging in conjunction with UV-C radiation can be applied to control foodborne pathogens in the dairy industry. Copyright © 2016. Published by Elsevier Ltd.

  5. Using UVC Light-Emitting Diodes at Wavelengths of 266 to 279 Nanometers To Inactivate Foodborne Pathogens and Pasteurize Sliced Cheese

    Science.gov (United States)

    Kim, Soo-Ji; Kim, Do-Kyun

    2015-01-01

    UVC light is a widely used sterilization technology. However, UV lamps have several limitations, including low activity at refrigeration temperatures, a long warm-up time, and risk of mercury exposure. UV-type lamps only emit light at 254 nm, so as an alternative, UV light-emitting diodes (UV-LEDs) which can produce the desired wavelengths have been developed. In this study, we validated the inactivation efficacy of UV-LEDs by wavelength and compared the results to those of conventional UV lamps. Selective media inoculated with Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes were irradiated using UV-LEDs at 266, 270, 275, and 279 nm in the UVC spectrum at 0.1, 0.2, 0.5, and 0.7 mJ/cm2, respectively. The radiation intensity of the UV-LEDs was about 4 μW/cm2, and UV lamps were covered with polypropylene films to adjust the light intensity similar to those of UV-LEDs. In addition, we applied UV-LED to sliced cheese at doses of 1, 2, and 3 mJ/cm2. Our results showed that inactivation rates after UV-LED treatment were significantly different (P UV lamps at a similar intensity. On microbiological media, UV-LED treatments at 266 and 270 nm showed significantly different (P < 0.05) inactivation effects than other wavelength modules. For sliced cheeses, 4- to 5-log reductions occurred after treatment at 3 mJ/cm2 for all three pathogens, with negligible generation of injured cells. PMID:26386061

  6. Using UVC Light-Emitting Diodes at Wavelengths of 266 to 279 Nanometers To Inactivate Foodborne Pathogens and Pasteurize Sliced Cheese.

    Science.gov (United States)

    Kim, Soo-Ji; Kim, Do-Kyun; Kang, Dong-Hyun

    2016-01-01

    UVC light is a widely used sterilization technology. However, UV lamps have several limitations, including low activity at refrigeration temperatures, a long warm-up time, and risk of mercury exposure. UV-type lamps only emit light at 254 nm, so as an alternative, UV light-emitting diodes (UV-LEDs) which can produce the desired wavelengths have been developed. In this study, we validated the inactivation efficacy of UV-LEDs by wavelength and compared the results to those of conventional UV lamps. Selective media inoculated with Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes were irradiated using UV-LEDs at 266, 270, 275, and 279 nm in the UVC spectrum at 0.1, 0.2, 0.5, and 0.7 mJ/cm(2), respectively. The radiation intensity of the UV-LEDs was about 4 μW/cm(2), and UV lamps were covered with polypropylene films to adjust the light intensity similar to those of UV-LEDs. In addition, we applied UV-LED to sliced cheese at doses of 1, 2, and 3 mJ/cm(2). Our results showed that inactivation rates after UV-LED treatment were significantly different (P < 0.05) from those of UV lamps at a similar intensity. On microbiological media, UV-LED treatments at 266 and 270 nm showed significantly different (P < 0.05) inactivation effects than other wavelength modules. For sliced cheeses, 4- to 5-log reductions occurred after treatment at 3 mJ/cm(2) for all three pathogens, with negligible generation of injured cells. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Inactivation of the Major Hemolysin Gene Influences Expression of the Nonribosomal Peptide Synthetase Gene swrA in the Insect Pathogen Serratia sp. Strain SCBI.

    Science.gov (United States)

    Petersen, Lauren M; LaCourse, Kaitlyn; Schöner, Tim A; Bode, Helge; Tisa, Louis S

    2017-11-01

    Hemolysins are important virulence factors for many bacterial pathogens, including Serratia marcescens The role of the major hemolysin gene in the insect pathogen Serratia sp. strain SCBI was investigated using both forward and reverse-genetics approaches. Introduction of the major hemolysin gene into Escherichia coli resulted in a gain of both virulence and hemolytic activity. Inactivation of this hemolysin in Serratia sp. SCBI resulted in a loss of hemolysis but did not attenuate insecticidal activity. Unexpectedly, inactivation of the hemolysin gene in Serratia sp. SCBI resulted in significantly increased motility and increased antimicrobial activity. Reverse transcription-quantitative PCR (qRT-PCR) analysis of mutants with a disrupted hemolysin gene showed a dramatic increase in mRNA levels of a nonribosomal peptide synthetase gene, swrA , which produces the surfactant serrawettin W2. Mutation of the swrA gene in Serratia sp. SCBI resulted in highly varied antibiotic activity, motility, virulence, and hemolysis phenotypes that were dependent on the site of disruption within this 17.75-kb gene. When introduced into E. coli , swrA increases rates of motility and confers antimicrobial activity. While it is unclear how inactivation of the major hemolysin gene influences the expression of swrA , these results suggest that swrA plays an important role in motility and antimicrobial activity in Serratia sp. SCBI. IMPORTANCE The opportunistic Gram-negative bacteria of the genus Serratia are widespread in the environment and can cause human illness. A comparative genomics analysis between Serratia marcescens and a new Serratia species from South Africa, termed Serratia sp. strain SCBI, shows that these two organisms are closely related but differ in pathogenesis. S. marcescens kills Caenorhabditis nematodes, while Serratia sp. SCBI is not harmful and forms a beneficial association with them. This distinction presented the opportunity to investigate potential differences

  8. Evaluation of the U.S. Department of Agriculture's egg pasteurization processes on the inactivation of high pathogenicity avian influenza virus and velogenic Newcastle disease virus in processed egg products

    Science.gov (United States)

    High pathogenicity avian influenza virus (HPAIV) A/chicken/Pennsylvania/1370/1983 (H5N2), and velogenic Newcastle disease virus (vNDV) AMPV-1/California/212676/2002 were inoculated into various egg products then heat treated at various temperatures for 0 to 30 min to determine thermal inactivation p...

  9. Optimization of inactivated H5N9 highly pathogenic avian influenza vaccine and inactivated Salmonella enterica serovar Typhimurium vaccine with antigen dose and prime-boost regimen in domestic ducks.

    Science.gov (United States)

    Yuk, Seong-Su; To, Eredene-Ochir; Kwon, Jung-Hoon; Noh, Jin-Yong; Hong, Woo-Tack; Jeong, Jei-Hyun; Gwon, Gyeong-Bin; Song, Chang-Seon

    2017-09-01

    Owing to the increase in the number of diseases affecting ducks and the demand for food safety by consumers, vaccination has become one of the factors that influence duck meat productivity. The highly pathogenic avian influenza (HPAI) virus is one of the most prevalent and causes one of the most lethal diseases in domestic ducks, and Salmonella enterica serovar Typhimurium is a food-borne pathogen persistent in the domestic duck population. To better understand the optimal usage of HPAI and S. enterica serovar Typhimurium vaccines, we aimed to determine antigen dose, oil and gel adjuvant usage with prime-boost regimen, and vaccination age, inducing the best immune response in ducks, without an effect on body weight gain. In the case of the inactivated H5N9 vaccine, a single dose of vaccine was inadequate to induce proper antibody titer when administered to day-old ducks, which necessitates boost vaccination. Administration of the oil-adjuvanted H5N9 vaccine administration in day-old and 2-week-old ducks resulted in a lower body weight at the time of slaughtering, compared to that of gel-adjuvanted H5N9 vaccine. However, gel-adjuvanted H5N9 vaccine failed to induce proper immune response to an extent recommend by OIE-World Organization for Animal Health. In the case of the Salmonella enterica serovar Typhimurium vaccine, a moderate or low dose of vaccine was appropriate for day-old ducks receiving the gel prime-oil boost vaccination. Single vaccination with oil adjuvants affects the mean body weight of 7-week-old ducks, suggesting that the gel adjuvant is more suitable for meat production. We expect that the use of adjuvants in a prime-boost regimen and at antigen doses set in this study will be helpful to maximize body weight in the case of domestic duck production at the actual farm site. © 2017 Poultry Science Association Inc.

  10. Inactivation dynamics of 222 nm krypton-chlorine excilamp irradiation on Gram-positive and Gram-negative foodborne pathogenic bacteria.

    Science.gov (United States)

    Kang, Jun-Won; Kim, Sang-Soon; Kang, Dong-Hyun

    2018-07-01

    The object of this study was to elucidate the bactericidal mechanism of a 222 nm Krypton Chlorine (KrCl) excilamp compared with that of a 254 nm Low Pressure mercury (LP Hg) lamp. The KrCl excilamp had higher bactericidal capacity against Gram-positive pathogenic bacteria (Staphylococcus aureus and L. monocytogenes) and Gram-negative pathogenic bacteria (S. Typhimurium and E. coli O157:H7) than did the LP Hg lamp when cell suspensions in PBS were irradiated with each type of UV lamp. It was found out that the KrCl excilamp induced cell membrane damage as a form of depolarization. From the study of respiratory chain dehydrogenase activity and the lipid peroxidation assay, it was revealed that cell membrane damage was attributed to inactivation of enzymes related to generation of membrane potential and occurrence of lipid peroxidation. Direct absorption of UV radiation which led to photoreaction through formation of an excited state was one of the causes inducing cell damage. Additionally, generation of ROS and thus occurrence of secondary damage can be another cause. The LP Hg lamp only induced damage to DNA but not to other components such as lipids or proteins. This difference was derived from differences of UV radiation absorption by cellular materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Efficacy of two H5N9-inactivated vaccines against challenge with a recent H5N1 highly pathogenic avian influenza isolate from a chicken in Thailand.

    Science.gov (United States)

    Bublot, Michel; Le Gros, François-Xavier; Nieddu, Daniela; Pritchard, Nikki; Mickle, Thomas R; Swayne, David E

    2007-03-01

    The objective of this study was to compare the efficacy of two avian influenza (AI) H5-inactivated vaccines containing either an American (A/turkey/Wisconsin/68 H5N9; H5N9-WI) or a Eurasian isolate (A/chicken/Italy/22A/98 H5N9; H5N9-It). Three-week-old specific pathogen-free chickens were vaccinated once and challenged 3 wk later with a H5N1 highly pathogenic AI (HPAI) virus isolated from a chicken in Thailand in 2004. All unvaccinated challenged birds died within 2 days, whereas 90% and 100% of chickens vaccinated with H5N9-WI and H5N9-It, respectively, were protected against morbidity and mortality. Both vaccines prevented cloacal shedding and significantly reduced oral shedding of the challenge HPAI virus. Additional chickens (vaccinated or unvaccinated) were placed in contact with the directly challenged birds 18 hr after challenge. All unvaccinated chickens in contact with unvaccinated challenged birds died within 3 days after contact, whereas unvaccinated chickens in contact with vaccinated challenged birds either showed a significantly delayed mortality or did not become infected. All vaccinated contacts were protected against clinical signs, and most chickens did not shed detectable amount of HPAI virus. Altogether, these data indicate that both vaccines protected very well against morbidity and mortality and reduced or prevented shedding induced by direct or contact exposure to Asian H5N1 HPAI virus.

  12. Inactivation of the Haemophilus ducreyi luxS gene affects the virulence of this pathogen in human subjects.

    Science.gov (United States)

    Labandeira-Rey, Maria; Janowicz, Diane M; Blick, Robert J; Fortney, Kate R; Zwickl, Beth; Katz, Barry P; Spinola, Stanley M; Hansen, Eric J

    2009-08-01

    Haemophilus ducreyi 35000HP contains a homologue of the luxS gene, which encodes an enzyme that synthesizes autoinducer 2 (AI-2) in other gram-negative bacteria. H. ducreyi 35000HP produced AI-2 that functioned in a Vibrio harveyi-based reporter system. A H. ducreyi luxS mutant was constructed by insertional inactivation of the luxS gene and lost the ability to produce AI-2. Provision of the H. ducreyi luxS gene in trans partially restored AI-2 production by the mutant. The luxS mutant was compared with its parent for virulence in the human challenge model of experimental chancroid. The pustule-formation rate in 5 volunteers was 93.3% (95% confidence interval, 81.7%-99.9%) at 15 parent sites and 60.0% (95% confidence interval, 48.3%-71.7%) at 15 mutant sites (1-tailed P < .001). Thus, the luxS mutant was partially attenuated for virulence. This is the first report of AI-2 production contributing to the pathogenesis of a genital ulcer disease.

  13. Survival and High-Hydrostatic Pressure Inactivation of Foodborne Pathogens in Salmorejo, a Traditional Ready-to-Eat Food.

    Science.gov (United States)

    Toledo Del Árbol, Julia; Pérez Pulido, Rubén; Grande, Ma José; Gálvez, Antonio; Lucas, Rosario

    2015-11-01

    Salmorejo is a traditional tomato-based creamy product. Because salmorejo is not heat-processed, there is a risk of contamination with foodborne pathogens from raw materials. Even though bacterial growth in salmorejo is strongly inhibited because of its acidic pH (close to 3.9), the growth and survival of 3 foodborne pathogens in this food has not been studied before. In this study, 3 cocktails consisting of Escherichia coli O157, Salmonella enterica serovar Enteritidis, and Listeria monocytogenes strains were inoculated in freshly prepared salmorejo. The food was treated by high hydrostatic pressure (HHP) at 400, 500, or 600 MPa for 8 min, or left untreated, and stored at 4 °C for 30 d. Viable cell counts were determined on selective media and also by the triple-layer agar method in order to detect sublethally injured cells. In control samples, L. monocytogenes viable cells decreased by 2.4 log cycles at day 7 and were undetectable by day 15. S. enterica cells decreased by 0.5 or 2.4 log cycles at days 7 and 15 respectively, but still were detectable at day 30. E. coli O157 cells survived much better in salmorejo, decreasing only by 1.5 log cycles at day 30. Treatments at pressures of 400 MPa or higher reduced viable counts of L. monocytogenes and S. enterica to undetectable levels. HHP treatments significantly (P food, usually produced on a small scale. HHP treatment at 600 MPa for 8 min can be an efficient nonthermal method for industrial-scale preparation of preservative-free salmorejo with improved safety against transmission of foodborne pathogens L. monocytogenes serotyes 4a and 4b, S. enterica serovar Enteritidis, and E. coli O157. © 2015 Institute of Food Technologists®

  14. Treatment of blood with a pathogen reduction technology using UV light and riboflavin inactivates Ebola virus in vitro

    Science.gov (United States)

    Cap, Andrew P.; Pidcoke, Heather F.; Keil, Shawn D.; Staples, Hilary M.; Anantpadma, Manu; Carrion, Ricardo; Davey, Robert A.; Frazer-Abel, Ashley; Taylor, Audra L.; Gonzales, Richard; Patterson, Jean L.; Goodrich, Raymond P.

    2018-01-01

    BACKGROUND Transfusion of plasma from recovered patients after Ebolavirus (EBOV) infection, typically called ‘convalescent plasma,’ is an effective treatment for active disease available in endemic areas, but carries the risk of introducing other pathogens, including other strains of EBOV. A pathogen reduction technology using ultraviolet light and riboflavin (UV + RB) is effective against multiple enveloped, negative-sense, single-stranded RNA viruses that are similar in structure to EBOV. We hypothesized that UV + RB is effective against EBOV in blood products without activating complement or reducing protective immunoglobulin titers that are important for the treatment of ebolavirus disease (EVD). STUDY DESIGN AND METHODS Four in vitro experiments were conducted to evaluate effects of UV + RB on green fluorescent protein EBOV (EBOV-GFP), wild-type EBOV in serum and whole blood, respectively, and on immunoglobulins and complement in plasma. Initial titers for Experiments 1–3 were: 4.21 log10 GFP units/mL, 4.96 log10 infectious units per mL, and 4.23 log10 plaque forming units per mL (PFU/mL). Conditions tested in the first three experiments included: 1. EBOV-GFP + UV + RB; 2. EBOV-GFP + RB only; 3 EBOV-GFP + UV only; 4. EBOV-GFP without RB or UV; 5. Virus-free control + UV only; and 6. Virus-free control without RB or UV. RESULTS UV + RB reduced EBOV titers to non-detectable levels in both non-human primate serum (≥ 2.8 to 3.2 log reduction) and human whole blood (≥ 3.0 log reduction) without decreasing protective antibody titers in human plasma. CONCLUSION Our in vitro results demonstrate that the UV + RB treatment efficiently reduces EBOV titers to below limits of detection in both serum and whole blood. In vivo testing to determine whether UV + RB can improve convalescent blood product safety is indicated. PMID:27001363

  15. Treatment of blood with a pathogen reduction technology using ultraviolet light and riboflavin inactivates Ebola virus in vitro.

    Science.gov (United States)

    Cap, Andrew P; Pidcoke, Heather F; Keil, Shawn D; Staples, Hilary M; Anantpadma, Manu; Carrion, Ricardo; Davey, Robert A; Frazer-Abel, Ashley; Taylor, Audra L; Gonzales, Richard; Patterson, Jean L; Goodrich, Raymond P

    2016-03-01

    Transfusion of plasma from recovered patients after Ebolavirus (EBOV) infection, typically called "convalescent plasma," is an effective treatment for active disease available in endemic areas, but carries the risk of introducing other pathogens, including other strains of EBOV. A pathogen reduction technology using ultraviolet light and riboflavin (UV+RB) is effective against multiple enveloped, negative-sense, single-stranded RNA viruses that are similar in structure to EBOV. We hypothesized that UV+RB is effective against EBOV in blood products without activating complement or reducing protective immunoglobulin titers that are important for the treatment of Ebola virus disease (EVD). Four in vitro experiments were conducted to evaluate effects of UV+RB on green fluorescent protein EBOV (EBOV-GFP), wild-type EBOV in serum, and whole blood, respectively, and on immunoglobulins and complement in plasma. Initial titers for Experiments 1 to 3 were 4.21 log GFP units/mL, 4.96 log infectious units/mL, and 4.23 log plaque-forming units/mL. Conditions tested in the first three experiments included the following: 1-EBOV-GFP plus UV+RB; 2-EBOV-GFP plus RB only; 3-EBOV-GFP plus UV only; 4-EBOV-GFP without RB or UV; 5-virus-free control plus UV only; and 6-virus-free control without RB or UV. UV+RB reduced EBOV titers to nondetectable levels in both nonhuman primate serum (≥2.8- to 3.2-log reduction) and human whole blood (≥3.0-log reduction) without decreasing protective antibody titers in human plasma. Our in vitro results demonstrate that the UV+RB treatment efficiently reduces EBOV titers to below limits of detection in both serum and whole blood. In vivo testing to determine whether UV+RB can improve convalescent blood product safety is indicated. © 2016 AABB.

  16. Blood-borne virus transmission in healthcare settings in Ireland: review of patient notification exercises 1997-2011.

    LENUS (Irish Health Repository)

    Donohue, S

    2012-01-21

    A review of patient notification exercises (PNEs) carried out in Ireland between 1997 and 2011 to investigate potential exposure to blood-borne viruses (BBVs) in healthcare settings was undertaken to inform future policy and practice. A questionnaire was sent to key informants in the health services to identify all relevant PNEs. Structured interviews were conducted with key investigators, and available documentation was examined. Ten BBV-related PNEs were identified. Despite testing over 2000 patients, only one case of transmission was found. However, in-depth local investigations before undertaking the PNEs identified six cases of healthcare-associated transmission.

  17. Al(III), Pd(II), and Zn(II) phthalocyanines for inactivation of dental pathogen Aggregatibacter actinomycetemcomitans as planktonic and biofilm-cultures

    Science.gov (United States)

    Kussovski, V.; Mantareva, V.; Angelov, I.; Avramov, L.; Popova, E.; Dimitrov, S.

    2012-06-01

    The Gram-negative, oral bacterium Aggregatibacter actinomycetemcomitans has been implicated as the causative agent of several forms of periodontal disease in humans. The new periodontal disease treatments are emergence in order to prevent infection progression. Antimicrobial photodynamic therapy (a-PDT) can be a useful tool for this purpose. It involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent in the presence of oxygen for eradication of target cells, and appears effective in photoinactivation of microorganisms. The phthalocyanine metal complexes of Pd(II)- (PdPcC) and Al(III)- (AlPc1) were evaluated as photodynamic sensitizers towards a dental pathogen A. actinomycetemcomitans in comparison to the known methylpyridyloxy-substituted Zn(II) phthalocyanine (ZnPcMe). The planktonic and biofilm-cultivated species of A. actinomycetemcomitans were treated. The photophysical results showed intensive and far-red absorbance with high tendency of aggregation for Pd(II)-phthalocyanine. The dark toxicities of both photosensitizers were negligible at concentrations used (bacteria was full photoinactivation after a-PDT with ZnPcMe. In case of the newly studied complexes, the effect was lower for PdPcC (4 log) as well as for AlPc1 (1.5-2 log). As it is known the bacterial biofilms were more resistant to a-PDT, which was confirmed for A. actinomycetemcomitans biofilms with 3 log reductions of viable cells after treatment with ZnPcMe and approximately 1 log reduction of biofilms after PdPcC and AlPc1. The initial results suggest that a-PDT can be useful for effective inactivation of dental pathogen A. actinomycetemcomitans.

  18. Association of ABO and Rh Blood Groups to Blood-Borne Infections among Blood Donors in Tehran-Iran.

    Science.gov (United States)

    Mohammadali, Fatemeh; Pourfathollah, Aliakbar

    2014-07-01

    The aim of this study was to investigate the prevalence of hepatitis B, hepatitis C, HIV and syphilis infections in blood donors referred to Tehran Blood Transfusion Center (TBTC), and determine any association between blood groups and blood- borne infections between the years of 2005 and 2011. This was a retrospective study conducted at TBTC. All of the donor serum samples were screened for HBV, HCV, HIV and syphilis by using third generation ELISA kits and RPR test. Initial reactive samples were tested in duplicate. Confirmatory tests were performed on all repeatedly reactive donations. Blood group was determined by forward and reverse blood grouping. The results were subjected to chi square analysis for determination of statistical difference between the values among different categories according to SPSS program. Overall, 2031451 donor serum samples were collected in 2005-2011. Totally, 10451 were positive test for HBV, HCV, HIV and syphilis. The overall seroprevalence of HBV, HCV, HIV, and syphilis was 0.39%, 0.11%, 0.005%, and 0.010%, respectively. Hepatitis B and HIV infections were significantly associated with blood group of donors (P blood group "A" and percentage of HBs Ag was lower in donors who had blood group O. There was no significant association between Hepatitis C and syphilis infections with ABO and Rh blood groups (P>0.05). Compared with neighboring countries and the international standards, prevalence of blood-borne infections is relatively low.

  19. Inactivation of Zika virus by solvent/detergent treatment of human plasma and other plasma-derived products and pasteurization of human serum albumin.

    Science.gov (United States)

    Kühnel, Denis; Müller, Sebastian; Pichotta, Alexander; Radomski, Kai Uwe; Volk, Andreas; Schmidt, Torben

    2017-03-01

    In 2016 the World Health Organization declared the mosquito-borne Zika virus (ZIKV) a "public health emergency of international concern." ZIKV is a blood-borne pathogen, which therefore causes concerns regarding the safety of human plasma-derived products due to potential contamination of the blood supply. This study investigated the effectiveness of viral inactivation steps used during the routine manufacturing of various plasma-derived products to reduce ZIKV infectivity. Human plasma and intermediates from the production of various plasma-derived products were spiked with ZIKV and subjected to virus inactivation using the identical techniques (either solvent/detergent [S/D] treatment or pasteurization) and conditions used for the actual production of the respective products. Samples were taken and the viral loads measured before and after inactivation. After S/D treatment of spiked intermediates of the plasma-derived products Octaplas(LG), Octagam, and Octanate, the viral loads were below the limit of detection in all cases. The mean log reduction factor (LRF) was at least 6.78 log for Octaplas(LG), at least 7.00 log for Octagam, and at least 6.18 log for Octanate after 60, 240, and 480 minutes of S/D treatment, respectively. For 25% human serum albumin (HSA), the mean LRF for ZIKV was at least 7.48 log after pasteurization at 60°C for 120 minutes. These results demonstrate that the commonly used virus inactivation processes utilized during the production of human plasma and plasma-derived products, namely, S/D treatment or pasteurization, are effective for inactivation of ZIKV. © 2016 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  20. Efficacy of single dose of a bivalent vaccine containing inactivated Newcastle disease virus and reassortant highly pathogenic avian influenza H5N1 virus against lethal HPAI and NDV infection in chickens.

    Directory of Open Access Journals (Sweden)

    Dong-Hun Lee

    Full Text Available Highly pathogenic avian influenza (HPAI and Newcastle disease (ND are 2 devastating diseases of poultry, which cause great economic losses to the poultry industry. In the present study, we developed a bivalent vaccine containing antigens of inactivated ND and reassortant HPAI H5N1 viruses as a candidate poultry vaccine, and we evaluated its immunogenicity and protective efficacy in specific pathogen-free chickens. The 6:2 reassortant H5N1 vaccine strain containing the surface genes of the A/Chicken/Korea/ES/2003(H5N1 virus was successfully generated by reverse genetics. A polybasic cleavage site of the hemagglutinin segment was replaced by a monobasic cleavage site. We characterized the reverse genetics-derived reassortant HPAI H5N1 clade 2.5 vaccine strain by evaluating its growth kinetics in eggs, minimum effective dose in chickens, and cross-clade immunogenicity against HPAI clade 1 and 2. The bivalent vaccine was prepared by emulsifying inactivated ND (La Sota strain and reassortant HPAI viruses with Montanide ISA 70 adjuvant. A single immunization with this vaccine induced high levels of hemagglutination-inhibiting antibody titers and protected chickens against a lethal challenge with the wild-type HPAI and ND viruses. Our results demonstrate that the bivalent, inactivated vaccine developed in this study is a promising approach for the control of both HPAI H5N1 and ND viral infections.

  1. Gene inactivation in the plant pathogen Glomerella cingulata: three strategies for the disruption of the pectin lyase gene pnlA.

    Science.gov (United States)

    Bowen, J K; Templeton, M D; Sharrock, K R; Crowhurst, R N; Rikkerink, E H

    1995-01-20

    The feasibility of performing routine transformation-mediated mutagenesis in Glomerella cingulata was analysed by adopting three one-step gene disruption strategies targeted at the pectin lyase gene pnlA. The efficiencies of disruption following transformation with gene replacement- or gene truncation-disruption vectors were compared. To effect replacement-disruption, G. cingulata was transformed with a vector carrying DNA from the pnlA locus in which the majority of the coding sequence had been replaced by the gene for hygromycin B resistance. Two of the five transformants investigated contained an inactivated pnlA gene (pnlA-); both also contained ectopically integrated vector sequences. The efficacy of gene disruption by transformation with two gene truncation-disruption vectors was also assessed. Both vectors carried at 5' and 3' truncated copy of the pnlA coding sequence, adjacent to the gene for hygromycin B resistance. The promoter sequences controlling the selectable marker differed in the two vectors. In one vector the homologous G. cingulata gpdA promoter controlled hygromycin B phosphotransferase expression (homologous truncation vector), whereas in the second vector promoter elements were from the Aspergillus nidulans gpdA gene (heterologous truncation vector). Following transformation with the homologous truncation vector, nine transformants were analysed by Southern hybridisation; no transformants contained a disrupted pnlA gene. Of nineteen heterologous truncation vector transformants, three contained a disrupted pnlA gene; Southern analysis revealed single integrations of vector sequence at pnlA in two of these transformants. pnlA mRNA was not detected by Northern hybridisation in pnlA- transformants. pnlA- transformants failed to produce a PNLA protein with a pI identical to one normally detected in wild-type isolates by silver and activity staining of isoelectric focussing gels. Pathogenesis on Capsicum and apple was unaffected by disruption of

  2. No evidence for involvement of plasma proteins or blood-borne cells in amyloid plaque formation in scrapie-affected mice. An immunohistoperoxidase study

    NARCIS (Netherlands)

    Eikelenboom, P.; Scott, J. R.; McBride, P. A.; Rozemuller, J. M.; Bruce, M. E.; Fraser, H.

    1987-01-01

    The present study was designed to investigate blood-brain permeability and the possible involvement of plasma proteins and blood-borne cells in amyloid plaque formation in scrapie-affected mice. No abnormal extravasation of intravenously injected horseradish peroxidase (HRP) was found and with

  3. HIV and selected blood-borne and sexually transmitted infections in a predominantly Roma (Gypsy) neighbourhood in Budapest, Hungary

    Science.gov (United States)

    Gyarmathy, V. Anna; Ujhelyi, Eszter; Neaigus, Alan

    2008-01-01

    We assessed the prevalence of HIV and selected blood-borne and sexually transmitted infections among a convenience sample of 64 residents of Dzsumbuj, a predominantly Roma (Gypsy) neighbourhood in Budapest, Hungary. No cases of HIV were detected, while the prevalence of Hepatitis B infection (anti-HBc) was 27% and syphilis prevalence was 2%. Romas (n=50) were significantly more likely than non-Romas (n=14) to have HAV antibodies (80% vs. 43%) and less likely to be HBV immunized (anti-HBs only; 6% vs. 29%). Current drug injectors (n=13) were more likely than non-injectors (n=51) to have antibodies against HAV (85% vs. 69%) and HCV (85% vs. 8%). While HIV has not been introduced in this population, risk conditions for a potentially explosive HIV epidemic are present. Health care policies should focus on expanding coverage for HAV and HBV immunizations, and access to HIV preventive services needs to be extended to marginalized, mostly minority populations, such as the Roma in Europe. PMID:18935777

  4. Blood borne viral infections among Danish Health Care Workers - frequent blood exposure but low prevalence of infection

    International Nuclear Information System (INIS)

    Fisker, Niels; Mygind, Lone H.; Krarup, Henrik B.; Licht, Dorthe; Georgsen, Jorgen; Christensen, Peer B.

    2004-01-01

    Denmark is a country with low prevalence and incidence of blood borne viral infections. Among health care workers (HCWs) vaccination for hepatitis B is only offered to high-risk groups. The aims of this cross sectional survey were to determine the prevalence of hepatitis B, -C, and human immunodeficiency virus (HIV) among the staff at a Danish University hospital and to correlate this with risk factors for transmission. Additionally, we wanted to examine the current frequency of blood exposure, reporting habits and hepatitis B vaccination status in the staff. Of 1439 eligible hospital staffs included, 960 (67%) were HCWs. The overall human immunodeficiency virus (HIV)-, hepatitis C Virus (HCV)- and hepatitis B Virus (HBV)-prevalence was 0% (0/1439), 0.14% (2/1439) and 1.6% (23/1439), respectively. Twenty-three percent of HCWs were vaccinated against HBV. Age, blood transfusion and stay in endemic areas were associated independently to HBV infection as opposed to job-category, duration of employment, HBV vaccination status and blood exposure. Based on a 4-week recall period, the incidence of percutaneous blood exposure was 1.5/person-year. In conclusion the HIV and hepatitis prevalence was low despite frequent blood exposure and the principal risk factors were unrelated to work. Danish HCWs do not seem to be at increased risk of hepatitis B even though universal HBV vaccination has not been implemented

  5. Families Living with Blood-Borne Viruses: The Case for Extending the Concept of “Serodiscordance”

    Directory of Open Access Journals (Sweden)

    Asha Persson

    2017-01-01

    Full Text Available The concept of “serodiscordance” (mixed infection status is primarily associated with epidemiological concerns about HIV transmission risk in couples. We make the case for extending this concept to include families with mixed HIV and viral hepatitis status. Social research on couples with mixed HIV and hepatitis C status has laid an important foundation for illuminating how experiences of serodiscordance within intimate partnerships are much broader than concerns about risk. This body of work attests to serodiscordance holding promise as a valuable concept for understanding viral infections as socially situated and intensely relational phenomena. However, serodiscordance is still limited as a concept because of its near universal focus on couples. It is rarely applied to wider relationships, including family networks beyond the couple. Despite evidence in the literature that families are affected by blood-borne viruses in multiple social, emotional, financial, and generational ways, the concept of serodiscordance does not capture these broader dynamics. Making serodiscordance more inclusive is an important step in recognising the diverse ways families’ everyday lives, relationships, and futures can be entangled with HIV, hepatitis C, and hepatitis B, and for understanding how today’s era of effective treatment options might shape the “family life” of viral infections.

  6. A physiological model of the interaction between tissue bubbles and the formation of blood-borne bubbles under decompression

    International Nuclear Information System (INIS)

    Chappell, M A; Payne, S J

    2006-01-01

    Under decompression, bubbles can form in the human body, and these can be found both within the body tissues and the bloodstream. Mathematical models for the growth of both types of bubbles have previously been presented, but they have not been coupled together. This work thus explores the interaction between the growth of tissue and blood-borne bubbles under decompression, specifically looking at the extent to which they compete for the common resource of inert gas held in solution in the tissues. The influence of tissue bubbles is found to be significant for densities as low as 10 ml -1 for tissues which are poorly perfused. However, the effects of formation of bubbles in the blood are not found until the density of bubble production sites reaches 10 6 ml -1 . From comparison of the model predictions with experimental evidence for bubbles produced in animals and man under decompression, it is concluded that the density of tissue bubbles is likely to have a significant effect on the number of bubbles produced in the blood. However, the density of nucleation sites in the blood is unlikely to be sufficiently high in humans for the formation of bubbles in the blood to have a significant impact on the growth of the bubbles in the tissue

  7. Pulsed electric field processing of different fruit juices: impac of pH and temperature on inactivation of spoilage and pathogenic micro-organisms

    NARCIS (Netherlands)

    Timmermans, R.A.H.; Nierop Groot, M.N.; Nederhoff, A.L.; Boekel, van M.A.J.S.; Matser, A.M.; Mastwijk, H.C.

    2014-01-01

    Pulsed electrical field (PEF) technology can be used for the inactivation of micro-organisms and therefore for preservation of food products. It is a mild technology compared to thermal pasteurization because a lower temperature is used during processing, leading to a better retention of the

  8. Prevalence of Sexually Transmitted Diseases and Blood-Borne Transmitted Infections among Male Patients with Antisocial Personality Disorder

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    Hamza Yıldız

    2015-03-01

    Full Text Available Objective: The aim of this study was to compare the patients who have antisocial personality disorder (ASPD and the healthy individuals in terms of sexually transmitted diseases (STDs and Blood-Borne Transmitted Infections (BTIs prevalences. Methods: This study is a prospective, single-center, open-label, non-randomized controlled clinical study. There were two groups in the study. The patient group consistsed of 100 males who were diagnosed as ASPD with a clinical interview form. The control group consisted of 98 healthy males who did not have any psychiatric disorder. Dermatologic examination was performed, and clinical findings were recorded. Results: The mean age of the patient group was 21.96±2.40 (range 20-37 years. The mean age of the control group was 24.20±2.88 (21-36 years. The most common disease was gonorrhea (25% followed by genital wart (11%, molluskum contagiosum (5%, HBsAg (4%, and HSV-2 seropositivity (4% in the patients group. In the control group, HSV-2 seropositivity (4.08%, genital wart (3.06%, molluskum contagiosum (3.06%, and gonorrhe (1.02% were commonly seen in the control group. STDs and/or BVTIs were found more common in the patients group (82% than that in the control group (45.91% (X2=30.62, p=0.000. Conclusions: The patients with ASPD are at greater risk than normal population to catch a STDs or BTIs because of their lower educational levels and riskier behaviors. This condition entertains a risk in the general population and the patients themselves.

  9. Allspice, garlic and oregano plant essential oils in tomato films inactivate the foodborne pathogens, Escherichia coli O157:h7, Salmonella enterica and Listeria monocytogenes

    Science.gov (United States)

    Edible films containing plant essential oils arc gaining importance as potential antibacterial formulations to extend product shelf life and reduce risk of pathogen growth on food surfaces. An evaluation of both antimicrobial and physicochemical properties of edible films is important for applicatio...

  10. Pulmonary immunization of chickens using non-adjuvanted spray-freeze dried whole inactivated virus vaccine completely protects against highly pathogenic H5N1 avian influenza virus

    NARCIS (Netherlands)

    Peeters, Ben; Tonnis, Wouter F.; Murugappan, Senthil; Rottier, Peter; Koch, Guus; Frijlink, Henderik W.; Huckriede, Anke; Hinrichs, Wouter L. J.

    2014-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 virus is a major threat to public health as well as to the global poultry industry. Most fatal human infections are caused by contact with infected poultry. Therefore, preventing the virus from entering the poultry population is a priority. This is,

  11. Contemporary formulation and distribution practices for cold-filled acid products: Australian industry survey and modeling of published pathogen inactivation data.

    Science.gov (United States)

    Chapman, B; Scurrah, K J; Ross, T

    2010-05-01

    A survey of 12 Australian manufacturers indicated that mild-tasting acids and preservatives are used to partially replace acetic acid in cold-filled acid dressings and sauces. In contrast to traditional ambient temperature distribution practices, some manufacturers indicated that they supply the food service sector with cold-filled acid products prechilled for incorporation into ready-to-eat foods. The Comité des Industries des Mayonnaises et Sauces Condimentaires de la Communauté Economique Européenne (CIMSCEE) Code, a formulation guideline used by the industry to predict the safety of cold-filled acid formulations with respect to Salmonella enterica and Escherichia coli, does not extend to the use of acids and preservatives other than acetic acid nor does it consider the effects of chill distribution. We found insufficient data in the published literature to comprehensively model the response of S. enterica and E. coli to all of the predictor variables (i.e., pH, acetic acid, NaCl, sugars, other acids, preservatives, and storage temperature) of relevance for contemporary cold-filled acid products in Australia. In particular, we noted a lack of inactivation data for S. enterica at aqueous-phase NaCl concentrations of >3% (wt/wt). However, our simple models clearly identified pH and 1/absolute temperature of storage as the most important variables generally determining inactivation. To develop robust models to predict the effect of contemporary formulation and storage variables on product safety, additional empirical data are required. Until such models are available, our results support challenge testing of cold-filled acid products to ascertain their safety, as suggested by the CIMSCEE, but suggest consideration of challenging with both E. coli and S. enterica at incubation temperatures relevant to intended product distribution temperatures.

  12. Blood borne hormones in a cross-talk between peripheral and brain mechanisms regulating blood pressure, the role of circumventricular organs.

    Science.gov (United States)

    Ufnal, Marcin; Skrzypecki, Janusz

    2014-04-01

    Accumulating evidence suggests that blood borne hormones modulate brain mechanisms regulating blood pressure. This appears to be mediated by the circumventricular organs which are located in the walls of the brain ventricular system and lack the blood-brain barrier. Recent evidence shows that neurons of the circumventricular organs express receptors for the majority of cardiovascular hormones. Intracerebroventricular infusions of hormones and their antagonists is one approach to evaluate the influence of blood borne hormones on the neural mechanisms regulating arterial blood pressure. Interestingly, there is no clear correlation between peripheral and central effects of cardiovascular hormones. For example, angiotensin II increases blood pressure acting peripherally and centrally, whereas peripherally acting pressor catecholamines decrease blood pressure when infused intracerebroventricularly. The physiological role of such dual hemodynamic responses has not yet been clarified. In the paper we review studies on hemodynamic effects of catecholamines, neuropeptide Y, angiotensin II, aldosterone, natriuretic peptides, endothelins, histamine and bradykinin in the context of their role in a cross-talk between peripheral and brain mechanisms involved in the regulation of arterial blood pressure. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Prevalence of Blood-Borne Viruses in Health Care Workers of a Northern District in Pakistan: Risk Factors and Preventive Behaviors

    Directory of Open Access Journals (Sweden)

    Muhammad Zuhaib Khan

    2016-01-01

    Full Text Available Background. Blood-borne viral infections like viral hepatitis are highly prevalent in Pakistan. There is also a potential threat of human immunodeficiency virus (HIV spread in the country. Health care workers (HCWs are a high risk population for acquiring such viral infections and potential spread to the patients. This study aimed to determine the frequency of three blood-borne viruses: HCV, HBV, and HIV in HCWs of district Malakand in northern Khyber Pakhtunkhwa (KPK province of Pakistan. Moreover, risk factors and preventive behaviors among HCWs were investigated in detail. Materials and Methods. Prevalence was investigated using serological assays followed by real time polymerase chain reaction (RT-PCR based characterization. A total of 626 health care workers working at 17 different health care units, belonging to 6 different job categories, were included in this study. Results. HIV was not detected in the HCWs while rate of prevalence of HCV and HBV was far less (0.8 % and 0.64 %, resp. as compared to general population (4.7%–38%. The majority of HCWs were aware of the mode of spread of these viruses and associated risk factors. Needle stick injury was found to be the most important risk factor for possible acquisition of these infections.

  14. Nurse-led educational campaign on blood borne pathogens and proper sharps disposal at an urban tertiary hospital in Dar Es Salaam, Tanzania

    Directory of Open Access Journals (Sweden)

    A. Otieno

    2013-12-01

    Conclusion: The results of this study suggest that even with very high levels of immediate and delayed retention of educational content as measured by exam, the impact of an educational intervention on behavioural change may be much more short-lived. This has implications regarding the need for continuous education to support for workplace safety campaigns.

  15. Protection against H5N1 Highly Pathogenic Avian and Pandemic (H1N1) 2009 Influenza Virus Infection in Cynomolgus Monkeys by an Inactivated H5N1 Whole Particle Vaccine

    Science.gov (United States)

    Nakayama, Misako; Shichinohe, Shintaro; Itoh, Yasushi; Ishigaki, Hirohito; Kitano, Mitsutaka; Arikata, Masahiko; Pham, Van Loi; Ishida, Hideaki; Kitagawa, Naoko; Okamatsu, Masatoshi; Sakoda, Yoshihiro; Ichikawa, Takaya; Tsuchiya, Hideaki; Nakamura, Shinichiro; Le, Quynh Mai; Ito, Mutsumi; Kawaoka, Yoshihiro; Kida, Hiroshi; Ogasawara, Kazumasa

    2013-01-01

    H5N1 highly pathogenic avian influenza virus (HPAIV) infection has been reported in poultry and humans with expanding clade designations. Therefore, a vaccine that induces immunity against a broad spectrum of H5N1 viruses is preferable for pandemic preparedness. We established a second H5N1 vaccine candidate, A/duck/Hokkaido/Vac-3/2007 (Vac-3), in our virus library and examined the efficacy of inactivated whole particles of this strain against two clades of H5N1 HPAIV strains that caused severe morbidity in cynomolgus macaques. Virus propagation in vaccinated macaques infected with either of the H5N1 HPAIV strains was prevented compared with that in unvaccinated macaques. This vaccine also prevented propagation of a pandemic (H1N1) 2009 virus in macaques. In the vaccinated macaques, neutralization activity, which was mainly shown by anti-hemagglutinin antibody, against H5N1 HPAIVs in plasma was detected, but that against H1N1 virus was not detected. However, neuraminidase inhibition activity in plasma and T-lymphocyte responses in lymph nodes against H1N1 virus were detected. Therefore, cross-clade and heterosubtypic protective immunity in macaques consisted of humoral and cellular immunity induced by vaccination with Vac-3. PMID:24376571

  16. Protection against H5N1 highly pathogenic avian and pandemic (H1N1 2009 influenza virus infection in cynomolgus monkeys by an inactivated H5N1 whole particle vaccine.

    Directory of Open Access Journals (Sweden)

    Misako Nakayama

    Full Text Available H5N1 highly pathogenic avian influenza virus (HPAIV infection has been reported in poultry and humans with expanding clade designations. Therefore, a vaccine that induces immunity against a broad spectrum of H5N1 viruses is preferable for pandemic preparedness. We established a second H5N1 vaccine candidate, A/duck/Hokkaido/Vac-3/2007 (Vac-3, in our virus library and examined the efficacy of inactivated whole particles of this strain against two clades of H5N1 HPAIV strains that caused severe morbidity in cynomolgus macaques. Virus propagation in vaccinated macaques infected with either of the H5N1 HPAIV strains was prevented compared with that in unvaccinated macaques. This vaccine also prevented propagation of a pandemic (H1N1 2009 virus in macaques. In the vaccinated macaques, neutralization activity, which was mainly shown by anti-hemagglutinin antibody, against H5N1 HPAIVs in plasma was detected, but that against H1N1 virus was not detected. However, neuraminidase inhibition activity in plasma and T-lymphocyte responses in lymph nodes against H1N1 virus were detected. Therefore, cross-clade and heterosubtypic protective immunity in macaques consisted of humoral and cellular immunity induced by vaccination with Vac-3.

  17. [Public health, damage containment and the prevention of blood-borne and sexually transmitted infections: a review of the core concepts and their implementation in Brazil].

    Science.gov (United States)

    Elias, Lucília de Almeida; Bastos, Francisco Inacio

    2011-12-01

    This article assesses the historical context and the conceptual frame of setting up damage containment programs in the field of public health, with special emphasis on the Brazilian experience. The survey seeks to assess the relevance of such programs in the ongoing efforts to curb the spread of blood-borne and sexually transmitted infections, especially AIDS and hepatitis C. Findings from both the Brazilian and the international literature demonstrate that practical damage containment initiatives tend to be more effective when integrated with other public health measures based on common goals. Damage containment initiatives, aligned with the basic principles of public health do not limit themselves to a priori models or health care per se. They encompass a variety of pragmatic measures based on public policies and should be in line with the demands of the communities since the moment of their inception and implemented in the context of full partnership with such communities.

  18. Physical inactivation and stabilization of sludges

    International Nuclear Information System (INIS)

    Alexandre, D.

    1979-07-01

    High temperature conditioning of sludge is a stabilization process that insures sterilization. Both thermal pasteurization and irradiation are inactivation processes. Viruses and parasites are inactivated at 70-80 0 C. Total bacterial destruction requires higher temperatures and/or detention time. Radio sensitivity of pathogens and pertinent treatment parameters are examined. If sludge is to be land disposed, disinfection requires irradiation doses ranging 500 Krad; if cattle feeding is considered, the required dose is 1 Mrad

  19. Enhanced inactivation of food-borne pathogens in ready-to-eat sliced ham by near-infrared heating combined with UV-C irradiation and mechanism of the synergistic bactericidal action.

    Science.gov (United States)

    Ha, Jae-Won; Kang, Dong-Hyun

    2015-01-01

    The objective of the study described in this article was, first, to investigate the effect of the simultaneous application of near-infrared (NIR) heating and UV irradiation on inactivation of Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes in ready-to-eat (RTE) sliced ham and as well as its effect on product quality and, second, to elucidate the underlying mechanisms of the synergistic bactericidal action of NIR heating and UV irradiation. With the inoculation amounts used, simultaneous NIR-UV combined treatment for 70 s achieved 3.62, 4.17, and 3.43 log CFU reductions of E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively. For all three pathogens, the simultaneous application of both technologies resulted in an additional log unit reduction as a result of their synergism compared to the sum of the reductions obtained after the individual treatments. To investigate the mechanisms of NIR-UV synergistic injury for a particular microorganism in a food base, we evaluated the effect of four types of metabolic inhibitors using the overlay method and confirmed that damage to cellular membranes and the inability of cells to repair these structures due to ribosomal damage were the primary factors related to the synergistic lethal effect. Additionally, NIR-UV combined treatment for a maximum of 70 s did not alter the color values or texture parameters of ham slices significantly (P > 0.05). These results suggest that a NIR-UV combined process could be an innovative antimicrobial intervention for RTE meat products. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  20. Efficient uptake of blood-borne BK and JC polyomavirus-like particles in endothelial cells of liver sinusoids and renal vasa recta.

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    Jaione Simon-Santamaria

    Full Text Available Liver sinusoidal endothelial cells (LSECs are specialized scavenger cells that mediate high-capacity clearance of soluble waste macromolecules and colloid material, including blood-borne adenovirus. To explore if LSECs function as a sink for other viruses in blood, we studied the fate of virus-like particles (VLPs of two ubiquitous human DNA viruses, BK and JC polyomavirus, in mice. Like complete virions, VLPs specifically bind to receptors and enter cells, but unlike complete virions, they cannot replicate. 125I-labeled VLPs were used to assess blood decay, organ-, and hepatocellular distribution of ligand, and non-labeled VLPs to examine cellular uptake by immunohisto- and -cytochemistry. BK- and JC-VLPs rapidly distributed to liver, with lesser uptake in kidney and spleen. Liver uptake was predominantly in LSECs. Blood half-life (∼1 min, and tissue distribution of JC-VLPs and two JC-VLP-mutants (L55F and S269F that lack sialic acid binding affinity, were similar, indicating involvement of non-sialic acid receptors in cellular uptake. Liver uptake was not mediated by scavenger receptors. In spleen, the VLPs localized to the red pulp marginal zone reticuloendothelium, and in kidney to the endothelial lining of vasa recta segments, and the transitional epithelium of renal pelvis. Most VLP-positive vessels in renal medulla did not express PV-1/Meca 32, suggesting location to the non-fenestrated part of vasa recta. The endothelial cells of these vessels also efficiently endocytosed a scavenger receptor ligand, formaldehyde-denatured albumin, suggesting high endocytic activity compared to other renal endothelia. We conclude that LSECs very effectively cleared a large fraction of blood-borne BK- and JC-VLPs, indicating a central role of these cells in early removal of polyomavirus from the circulation. In addition, we report the novel finding that a subpopulation of endothelial cells in kidney, the main organ of polyomavirus persistence, showed

  1. HIV, Other Blood-Borne Viruses and Sexually Transmitted Infections amongst Expatriates and Travellers to Low- and Middle-Income Countries: A Systematic Review

    Science.gov (United States)

    Crawford, Gemma; Lobo, Roanna; Brown, Graham; Macri, Chloe; Smith, Hannah; Maycock, Bruce

    2016-01-01

    In some high-income countries, a proportion of human immunodeficiency virus (HIV), other blood-borne virus (BBV) or sexually transmitted infection (STI) diagnoses have been reported as acquired overseas in low- and middle-income countries. A review was conducted to explore HIV, other BBV or STI related knowledge, risk behavior and acquisition amongst expatriates and travelers, particularly males, travelling from high to low- and middle-income countries. Seven academic databases were searched for 26 peer reviewed articles that met inclusion criteria. Significant variability in the studies was noted, in age, travel duration and frequency and outcomes/risk factors measured and reported on. Risk factors described included longer duration of stay; being single; travel for romance or sex; alcohol and other drug use; lack of travel advice; being male; higher number of sexual partners; and inconsistent condom use. Vaccination, pre-travel health advice, and having fewer sexual partners were described as protective. Studies are needed focusing on the social context in which risk-taking occurs. Better collaboration is essential to deliver comprehensive health promotion interventions alongside more consistent pre- and post- travel testing and advice. Policy measures are crucial, including consistent evaluation indicators to assess impacts of HIV, other BBVs or STIs in the context of mobility. Risks and responses for these epidemics are shared globally. PMID:27999275

  2. Deceased Organ Donors With a History of Increased Risk Behavior for the Transmission of Blood-Borne Viral Infection: The UK Experience.

    Science.gov (United States)

    Trotter, Patrick B; Summers, Dominic M; Robb, Matthew; Hulme, William; Ushiro-Lumb, Ines; Watson, Christopher J E; Neuberger, James; Bradley, J Andrew

    2017-07-01

    Deceased organ donors are routinely screened for behaviors that increase the risk of transmissible blood-borne viral (BBV) infection, but the impact of this information on organ donation and transplant outcome is not well documented. Our aim was to establish the impact of such behavior on organ donation and utilization, as well transplant recipient outcomes. We identified all UK deceased organ donors from 2003 to 2015 with a disclosed history of increased risk behavior (IRB) including intravenous drug use (IVDU), imprisonment and increased risk sexual behavior. Of 17 262 potential donors, 659 (3.8%) had IRB for BBV and 285 (1.7%) were seropositive for BBV, of whom half had a history of IRB (mostly IVDU [78.5%]). Of actual donors with IRB, 393 were seronegative for viral markers at time of donation. A history of recent IVDU was associated with fewer potential donors proceeding to become actual organ donors (64% vs 75%, P = 0.007). Donors with IRB provided 1091 organs for transplantation (624 kidneys and 467 other organs). Transplant outcome was similar in recipients of organs from donors with and without IRB. There were 3 cases of unexpected hepatitis C virus transmission, all from an active IVDU donor who was hepatitis C virus seronegative at time of donation, but was found to be viremic on retrospective testing. Donors with a history of IRB provide a valuable source of organs for transplantation with good transplant outcomes and there is scope for increasing the use of organs from such donors.

  3. The best practice for preparation of samples from FTA®cards for diagnosis of blood borne infections using African trypanosomes as a model system

    Directory of Open Access Journals (Sweden)

    Welburn Susan C

    2011-05-01

    Full Text Available Abstract Background Diagnosis of blood borne infectious diseases relies primarily on the detection of the causative agent in the blood sample. Molecular techniques offer sensitive and specific tools for this although considerable difficulties exist when using these approaches in the field environment. In large scale epidemiological studies, FTA®cards are becoming increasingly popular for the rapid collection and archiving of a large number of samples. However, there are some difficulties in the downstream processing of these cards which is essential for the accurate diagnosis of infection. Here we describe recommendations for the best practice approach for sample processing from FTA®cards for the molecular diagnosis of trypanosomiasis using PCR. Results A comparison of five techniques was made. Detection from directly applied whole blood was less sensitive (35.6% than whole blood which was subsequently eluted from the cards using Chelex®100 (56.4%. Better apparent sensitivity was achieved when blood was lysed prior to application on the FTA cards (73.3% although this was not significant. This did not improve with subsequent elution using Chelex®100 (73.3% and was not significantly different from direct DNA extraction from blood in the field (68.3%. Conclusions Based on these results, the degree of effort required for each of these techniques and the difficulty of DNA extraction under field conditions, we recommend that blood is transferred onto FTA cards whole followed by elution in Chelex®100 as the best approach.

  4. The best practice for preparation of samples from FTA®cards for diagnosis of blood borne infections using African trypanosomes as a model system.

    Science.gov (United States)

    Ahmed, Heba A; MacLeod, Ewan T; Hide, Geoff; Welburn, Susan C; Picozzi, Kim

    2011-05-07

    Diagnosis of blood borne infectious diseases relies primarily on the detection of the causative agent in the blood sample. Molecular techniques offer sensitive and specific tools for this although considerable difficulties exist when using these approaches in the field environment. In large scale epidemiological studies, FTA®cards are becoming increasingly popular for the rapid collection and archiving of a large number of samples. However, there are some difficulties in the downstream processing of these cards which is essential for the accurate diagnosis of infection. Here we describe recommendations for the best practice approach for sample processing from FTA®cards for the molecular diagnosis of trypanosomiasis using PCR. A comparison of five techniques was made. Detection from directly applied whole blood was less sensitive (35.6%) than whole blood which was subsequently eluted from the cards using Chelex®100 (56.4%). Better apparent sensitivity was achieved when blood was lysed prior to application on the FTA cards (73.3%) although this was not significant. This did not improve with subsequent elution using Chelex®100 (73.3%) and was not significantly different from direct DNA extraction from blood in the field (68.3%). Based on these results, the degree of effort required for each of these techniques and the difficulty of DNA extraction under field conditions, we recommend that blood is transferred onto FTA cards whole followed by elution in Chelex®100 as the best approach.

  5. The best practice for preparation of samples from FTA®cards for diagnosis of blood borne infections using African trypanosomes as a model system

    Science.gov (United States)

    2011-01-01

    Background Diagnosis of blood borne infectious diseases relies primarily on the detection of the causative agent in the blood sample. Molecular techniques offer sensitive and specific tools for this although considerable difficulties exist when using these approaches in the field environment. In large scale epidemiological studies, FTA®cards are becoming increasingly popular for the rapid collection and archiving of a large number of samples. However, there are some difficulties in the downstream processing of these cards which is essential for the accurate diagnosis of infection. Here we describe recommendations for the best practice approach for sample processing from FTA®cards for the molecular diagnosis of trypanosomiasis using PCR. Results A comparison of five techniques was made. Detection from directly applied whole blood was less sensitive (35.6%) than whole blood which was subsequently eluted from the cards using Chelex®100 (56.4%). Better apparent sensitivity was achieved when blood was lysed prior to application on the FTA cards (73.3%) although this was not significant. This did not improve with subsequent elution using Chelex®100 (73.3%) and was not significantly different from direct DNA extraction from blood in the field (68.3%). Conclusions Based on these results, the degree of effort required for each of these techniques and the difficulty of DNA extraction under field conditions, we recommend that blood is transferred onto FTA cards whole followed by elution in Chelex®100 as the best approach. PMID:21548975

  6. Inactivation Data.xlsx

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data set is a spreadsheet that contains results of inactivation experiments that were conducted to to determine the effectiveness of chlorine in inactivating B....

  7. Modelling and application of the inactivation of microorganism

    International Nuclear Information System (INIS)

    Oğuzhan, P.; Yangılar, F.

    2013-01-01

    Prevention of consuming contaminated food with toxic microorganisms causing infections and consideration of food protection and new microbial inactivation methods are obligatory situations. Food microbiology is mainly related with unwanted microorganisms spoiling foods during processing and transporting stages and causing diseases. Determination of pathogen microorganisms is important for human health to define and prevent dangers and elongate shelf life. Inactivation of pathogen microorganisms can provide food security and reduce nutrient losses. Microbial inactivation which is using methods of food protection such as food safety and fresh. With this aim, various methods are used such as classical thermal processes (pasteurisation, sterilisation), pressured electrical field (PEF), ionised radiation, high pressure, ultrasonic waves and plasma sterilisation. Microbial inactivation modelling is a secure and effective method in food production. A new microbiological application can give useful results for risk assessment in food, inactivation of microorganisms and improvement of shelf life. Application and control methods should be developed and supported by scientific research and industrial applications

  8. The Prison Economy of Needles and Syringes: What Opportunities Exist for Blood Borne Virus Risk Reduction When Prices Are so High?

    Directory of Open Access Journals (Sweden)

    Carla Treloar

    Full Text Available A formal Needle and Syringe Program (NSP is not provided in Australian prisons. Injecting equipment circulates in prisons as part of an informal and illegal economy. This paper examined how this economy generates blood-borne virus (BBV risk and risk mitigation opportunities for inmates.The HITS-p cohort recruited New South Wales inmates who had reported ever injecting drugs and who had a negative HCV serological test within 12 months prior to enrolment. For this study, qualitative interviews were conducted with 30 participants enrolled in HITS-p. Participants included 10 women and were incarcerated in 12 prisons.A needle/syringe was nominated as being typically priced in the 'inside' prison economy at $100-$150, with a range of $50-$350. Purchase or hire of equipment was paid for in cash (including transactions that occurred outside prison and in exchange for drugs and other commodities. A range of other resources was required to enable successful needle/syringe economies, especially relationships with visitors and other prisoners, and violence to ensure payment of debts. Strategies to mitigate BBV risk included retaining one needle/syringe for personal use while hiring out others, keeping drug use (and ownership of equipment "quiet", stealing used equipment from the prison health clinic, and manufacture of syringes from other items available in the prison.The provision of prison NSP would disrupt the inside economies built around contraband needles/syringes, as well as minimise BBV risk. However, any model of prison NSP should be interrogated for any unanticipated markets that could be generated as a result of its regulatory practices.

  9. Evaluation of an e-learning package to improve understanding of blood-borne viruses amongst prison staff in Wales, UK.

    Science.gov (United States)

    Ellen Perrett, Stephanie; Erricker, Mark; Lyons, Marion

    2014-01-01

    The purpose of this paper is to provide education on blood-borne viruses (BBVs) to prison staff to help reduce stigma within the prisons, improve the care prisoners receive and reduce the risk of occupational transmission. An e-module was used to improve staff understanding of hepatitis B (HBV), hepatitis C (HCV) and HIV at a prison in Wales, UK. An assessment was used to gather data on prison staff understanding of BBVs prior to undertaking the e-module. In total, 530/697 (76 per cent) prison staff completed the BBV e-module. Average pre- and post-course assessment scores were 8.6/11 and 10.85/11, respectively. Most staff understood the modes of hepatitis transmission, however, gaps in understanding were highlighted. In total, 22 per cent of staff believed HBV and HCV were airborne, 9 per cent believed transmission occurred through sharing cutlery. In total, 31 per cent of staff believed prisoners with hepatitis should declare their status to the prison. Practical implications: The e-module significantly improved staff understanding of BBVs and should be incorporated into future prison training packages. Future education should include how BBVs are not transmitted with an emphasis on casual contact. Medical confidentiality in prisons should also be addressed. Improving understanding will help reduce the stigma of BBVs within prison and improve the multidisciplinary care the prisoner receives. To the authors knowledge this is the first published evaluation of a BBV learning package for custodial staff. Evaluation of this educational package demonstrates a unique and valuable insight into the general understanding of BBVs by prison staff in Wales, UK.

  10. Blood-borne interleukin-1β acts on the subfornical organ to upregulate the sympathoexcitatory milieu of the hypothalamic paraventricular nucleus.

    Science.gov (United States)

    Wei, Shun-Guang; Yu, Yang; Felder, Robert B

    2018-03-01

    We previously reported that microinjection of the proinflammatory cytokine interleukin-1β (IL-1β) into the subfornical organ (SFO) elicits a pressor response accompanied by increases in inflammation and renin-angiotensin system (RAS) activity in the SFO and hypothalamic paraventricular nucleus (PVN). The present study sought to determine whether blood-borne IL-1β induces similar neurochemical changes in the SFO and PVN and, if so, whether increased inflammation and RAS activity at the SFO level orchestrate the sympathoexcitatory response to circulating IL-1β. In urethane-anesthetized male Sprague-Dawley rats, intravenous injection of IL-1β (500 ng) increased blood pressure, heart rate, renal sympathetic nerve activity, and mRNA for angiotensin-converting enzyme, angiotensin II type 1a receptor, cyclooxygenase-2, tumor necrosis factor-α, and IL-1β, as well as the tumor necrosis factor-α p55 receptor and the IL-1 receptor, in the SFO and PVN. Pretreatment with SFO microinjections of the angiotensin II type 1a receptor blocker losartan (1 µg), the angiotensin-converting enzyme inhibitor captopril (1 µg), or the cyclooxygenase-2 inhibitor NS-398 (2 µg) attenuated expression of these excitatory mediators in the SFO and downstream in the PVN and the IL-1β-induced pressor responses. An SFO lesion minimized the IL-1β-induced expression of inflammatory and RAS components as well as c-Fos, an indicator of neuronal excitation, in the PVN. These studies demonstrate that circulating IL-1β, which increases in cardiovascular disorders such as hypertension and heart failure, acts on the SFO to increase inflammation and RAS activity in the SFO and PVN and that intervening in these neurochemical processes in the SFO can significantly reduce the sympathetic response.

  11. The Prison Economy of Needles and Syringes: What Opportunities Exist for Blood Borne Virus Risk Reduction When Prices Are so High?

    Science.gov (United States)

    Treloar, Carla; McCredie, Luke; Lloyd, Andrew R

    2016-01-01

    A formal Needle and Syringe Program (NSP) is not provided in Australian prisons. Injecting equipment circulates in prisons as part of an informal and illegal economy. This paper examined how this economy generates blood-borne virus (BBV) risk and risk mitigation opportunities for inmates. The HITS-p cohort recruited New South Wales inmates who had reported ever injecting drugs and who had a negative HCV serological test within 12 months prior to enrolment. For this study, qualitative interviews were conducted with 30 participants enrolled in HITS-p. Participants included 10 women and were incarcerated in 12 prisons. A needle/syringe was nominated as being typically priced in the 'inside' prison economy at $100-$150, with a range of $50-$350. Purchase or hire of equipment was paid for in cash (including transactions that occurred outside prison) and in exchange for drugs and other commodities. A range of other resources was required to enable successful needle/syringe economies, especially relationships with visitors and other prisoners, and violence to ensure payment of debts. Strategies to mitigate BBV risk included retaining one needle/syringe for personal use while hiring out others, keeping drug use (and ownership of equipment) "quiet", stealing used equipment from the prison health clinic, and manufacture of syringes from other items available in the prison. The provision of prison NSP would disrupt the inside economies built around contraband needles/syringes, as well as minimise BBV risk. However, any model of prison NSP should be interrogated for any unanticipated markets that could be generated as a result of its regulatory practices.

  12. Mycobacteria inactivation using Engineered Water Nanostructures (EWNS).

    Science.gov (United States)

    Pyrgiotakis, Georgios; McDevitt, James; Gao, Ya; Branco, Alan; Eleftheriadou, Mary; Lemos, Bernardo; Nardell, Edward; Demokritou, Philip

    2014-08-01

    Airborne transmitted pathogens such as Mycobacterium tuberculosis (Mtb) cause serious, often fatal infectious disease with enormous global health implications. Due to their unique cell wall and slow growth, mycobacteria are among the most resilient microbial forms. Herein we evaluate the ability of an emerging, chemical-free, nanotechnology-based method to inactivate M. parafortuitum (Mtb surrogate). This method is based on the transformation of atmospheric water vapor into engineered water nano-structures (EWNS) via electrospray. We demonstrate that the EWNS can interact with and inactivate airborne mycobacteria, reducing their concentration levels significantly. Additionally, EWNS can inactivate M. parafortuitum on surfaces eight times faster than the control. The mechanism of mycobacteria inactivation was also investigated in this study. It was demonstrated that the EWNS effectively deliver the reactive oxygen species, encapsulated during the electrospray process, to the bacteria oxidizing their cell membrane resulting into inactivation. Overall, this is a method with the potential to become an effective intervention technology in the battle against airborne infections. This study demonstrates the feasibility of mycobacterium inactivation in airborne form or on contact surfaces using electrospray activated water nano-structures. Given that the method is free of toxic chemicals, this might become an important tool in the prevention of mycobacterial infections, which are notoriously hard to treat. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Inactivated human platelet lysate with psoralen: a new perspective for mesenchymal stromal cell production in Good Manufacturing Practice conditions.

    Science.gov (United States)

    Castiglia, Sara; Mareschi, Katia; Labanca, Luciana; Lucania, Graziella; Leone, Marco; Sanavio, Fiorella; Castello, Laura; Rustichelli, Deborah; Signorino, Elena; Gunetti, Monica; Bergallo, Massimiliano; Bordiga, Anna Maria; Ferrero, Ivana; Fagioli, Franca

    2014-06-01

    Mesenchymal stromal cells (MSC) are ideal candidates for regenerative and immunomodulatory therapies. The use of xenogeneic protein-free Good Manufacturing Practice-compliant growth media is a prerequisite for clinical MSC isolation and expansion. Human platelet lysate (HPL) has been efficiently implemented into MSC clinical manufacturing as a substitute for fetal bovine serum (FBS). Because the use of human-derived blood materials alleviates immunologic risks but not the transmission of blood-borne viruses, the aim of our study was to test an even safer alternative than HPL to FBS: HPL subjected to pathogen inactivation by psoralen (iHPL). Bone marrow samples were plated and expanded in α-minimum essential medium with 10% of three culture supplements: HPL, iHPL and FBS, at the same time. MSC morphology, growth and immunophenotype were analyzed at each passage. Karyotype, tumorigenicity and sterility were analyzed at the third passage. Statistical analyses were performed. The MSCs cultivated in the three different culture conditions showed no significant differences in terms of fibroblast colony-forming unit number, immunophenotype or in their multipotent capacity. Conversely, the HPL/iHPL-MSCs were smaller, more numerous, had a higher proliferative potential and showed a higher Oct-3/4 and NANOG protein expression than did FBS-MSCs. Although HPL/iHPL-MSCs exhibit characteristics that may be attributable to a higher primitive stemness than FBS-MSCs, no tumorigenic mutations or karyotype modifications were observed. We demonstrated that iHPL is safer than HPL and represents a good, Good Manufacturing Practice-compliant alternative to FBS for MSC clinical production that is even more advantageous in terms of cellular growth and stemness. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  14. Towards Clinical Applications of Blood-Borne miRNA Signatures: The Influence of the Anticoagulant EDTA on miRNA Abundance.

    Directory of Open Access Journals (Sweden)

    Petra Leidinger

    Full Text Available Circulating microRNAs (miRNAs from blood are increasingly recognized as biomarker candidates for human diseases. Clinical routine settings frequently include blood sampling in tubes with EDTA as anticoagulant without considering the influence of phlebotomy on the overall miRNA expression pattern. We collected blood samples from six healthy individuals each in an EDTA blood collection tube. Subsequently, the blood was transferred into PAXgeneTM tubes at three different time points, i.e. directly (0 min, 10 min, and 2 h after phlebotomy. As control blood was also directly collected in PAXgeneTM blood RNA tubes that contain a reagent to directly lyse blood cells and stabilize their content. For all six blood donors at the four conditions (24 samples we analyzed the abundance of 1,205 miRNAs by human Agilent miRNA V16 microarrays.While we found generally a homogenous pattern of the miRNA abundance in all 24 samples, the duration of the EDTA treatment appears to influence the miRNA abundance of specific miRNAs. The most significant changes are observed after longer EDTA exposition. Overall, the impact of the different blood sample conditions on the miRNA pattern was substantially lower than intra-individual variations. While samples belonging to one of the six individuals mostly cluster together, there was no comparable clustering for any of the four tested blood sampling conditions. The most affected miRNA was miR-769-3p that was not detected in any of the six PAXgene blood samples, but in all EDTA 2h samples. Accordingly, hsa-miR-769-3p was also the only miRNA that showed a significantly different abundance between the 4 blood sample conditions by an ANOVA analysis (Benjamini-Hochberg adjusted p-value of 0.003. Validation by qRT-PCR confirmed this finding.The pattern of blood-borne miRNA abundance is rather homogenous between the four tested blood sample conditions of six blood donors. There was a clustering between the miRNA profiles that belong

  15. Processes for managing pathogens.

    Science.gov (United States)

    Godfree, Alan; Farrell, Joseph

    2005-01-01

    Wastewater contains human, animal, and plant pathogens capable of causing viral, bacterial, or parasitic infections. There are several routes whereby sewage pathogens may affect human health, including direct contact, contamination of food crops, zoonoses, and vectors. The range and numbers of pathogens in municipal wastewater vary with the level of endemic disease in the community, discharges from commercial activities, and seasonal factors. Regulations to control pathogen risk in the United States and Europe arising from land application of biosolids are based on the concept of multiple barriers to the prevention of transmission. The barriers are (i) treatment to reduce pathogen content and vector attraction, (ii) restrictions on crops grown on land to which biosolids have been applied, and (iii) minimum intervals following application and grazing or harvesting. Wastewater treatment reduces number of pathogens in the wastewater by concentrating them with the solids in the sludge. Although some treatment processes are designed specifically to inactivate pathogens, many are not, and the actual mechanisms of microbial inactivation are not fully understood for all processes. Vector attraction is reduced by stabilization (reduction of readily biodegradable material) and/or incorporation immediately following application. Concerns about health risks have renewed interest in the effects of treatment (on pathogens) and advanced treatment methods, and work performed in the United States suggests that Class A pathogen reduction can be achieved less expensively than previously thought. Effective pathogen risk management requires control to the complete chain of sludge treatment, biosolids handling and application, and post-application activities. This may be achieved by adherence to quality management systems based on hazard analysis critical control point (HACCP) principles.

  16. Pathogen reduction in sludges by irradiation

    International Nuclear Information System (INIS)

    Brandon, J.R.

    1978-01-01

    This paper presents results of pathogen inactivation programs being conducted in Belgium, Czechoslovakia, France, East Germany, West Germany, Hungary, Italy, The Netherlands, Poland, Spain, Sweden, Switzerland, the United Kingdom, and the United States

  17. Fullerene C60 and graphene photosensibiles for photodynamic virus inactivation

    Science.gov (United States)

    Belousova, I.; Hvorostovsky, A.; Kiselev, V.; Zarubaev, V.; Kiselev, O.; Piotrovsky, L.; Anfimov, P.; Krisko, T.; Muraviova, T.; Rylkov, V.; Starodubzev, A.; Sirotkin, A.; Grishkanich, A.; Kudashev, I.; Kancer, A.; Kustikova, M.; Bykovskaya, E.; Mayurova, A.; Stupnikov, A.; Ruzankina, J.; Afanasyev, M.; Lukyanov, N.; Redka, D.; Paklinov, N.

    2018-02-01

    A solid-phase photosensitizer based on aggregated C60 fullerene and graphene oxide for photodynamic inactivation of pathogens in biological fluids was studied. The most promising technologies of inactivation include the photodynamic effect, which consists in the inactivation of infectious agents by active oxygen forms (including singlet oxygen), formed when light is activated by the photosensitizer introduced into the plasma. Research shows features of solid-phase systems based on graphene and fullerene C60 oxide, which is a combination of an effective inactivating pathogens (for example, influenza viruses) reactive oxygen species formed upon irradiation of the photosensitizer in aqueous and biological fluids, a high photostability fullerene coatings and the possibility of full recovery photosensitizer from the biological environment after the photodynamic action.

  18. Chlorophyll mediated photodynamic inactivation of blue laser on Streptococcus mutans

    Science.gov (United States)

    Astuti, Suryani Dyah; Zaidan, A.; Setiawati, Ernie Maduratna; Suhariningsih

    2016-03-01

    Photodynamic inactivation is an inactivation method in microbial pathogens that utilize light and photosensitizer. This study was conducted to investigate photodynamic inactivation effects of low intensity laser exposure with various dose energy on Streptococcus mutans bacteria. The photodynamic inactivation was achieved with the addition of chlorophyll as photosensitizers. To determine the survival percentage of Streptococcus mutans bacteria after laser exposure, the total plate count method was used. For this study, the wavelength of the laser is 405 nm and variables of energy doses are 1.44, 2.87, 4.31, 5.74, 7.18, and 8.61 in J/cm2. The results show that exposure to laser with energy dose of 7.18 J/cm2 has the best photodynamic inactivation with a decrease of 78% in Streptococcus

  19. Effectiveness of irradiation in killing pathogens

    International Nuclear Information System (INIS)

    Yeager, J.G.; Ward, R.L.

    1980-01-01

    United States Environmental Protection Agency regulations include gamma ray irradiation of sludge as an approved Process to Further Reduce Pathogens (PFRP) prior to land application. Research at Sandia National Laboratories on pathogen inactivation in sludge by gamma irradiation has demonstrated that the 1 Mrad PFRP dose is capable, by itself, of eliminating bacterial, fungal, and parasitic pathogens from sludge. Gamma irradiation of sludge in conjunction with the required Processes to Significantly Reduce Pathogens (PSRP) should also eliminate the viral hazard from wastewater sludges

  20. Microbial electrolytic disinfection process for highly efficient Escherichia coli inactivation

    DEFF Research Database (Denmark)

    Zhou, Shaofeng; Huang, Shaobin; Li, Xiaohu

    2018-01-01

    extensively studied for recalcitrant organics removal, its application potential towards water disinfection (e.g., inactivation of pathogens) is still unknown. This study investigated the inactivation of Escherichia coli in a microbial electrolysis cell based bio-electro-Fenton system (renamed as microbial......Water quality deterioration caused by a wide variety of recalcitrant organics and pathogenic microorganisms has become a serious concern worldwide. Bio-electro-Fenton systems have been considered as cost-effective and highly efficient water treatment platform technology. While it has been......]OH was identified as one potential mechanism for disinfection. This study successfully demonstrated the feasibility of bio-electro-Fenton process for pathogens inactivation, which offers insight for the future development of sustainable, efficient, and cost-effective biological water treatment technology....

  1. Inactivation of bacteria in sewage sludge by ionizing radiation, heat, and thermoradiation

    International Nuclear Information System (INIS)

    Brandon, J.R.; Langley, S.L.

    1976-01-01

    For purposes of animal feeding or fertilizer usage on edible crops, sewage sludge must be free of pathogenic organisms. Bacterial inactivation by a combination of heat and irradiation is shown to be effective. These results must be viewed in conjunction with those from studies of parasite egg inactivation, virus inactivation, and physical-chemical benefits in order to make a fair assessment of the value of the thermoradiation treatment compared to other possible sludge treatment processes

  2. Inactivation of enteropathogenic E. coli by solar disinfection (SODIS) under simulated sunlight conditions

    CSIR Research Space (South Africa)

    Ubomba-Jaswa, Eunice

    2008-12-01

    Full Text Available of limitations. An important limitation is the lack of SODIS inactivation studies on some waterborne pathogens in the developing world. SODIS inactivation of enteropathogenic E. coli (EPEC), a major cause of infantile diarrhoea is reported for the first time...

  3. Ultraviolet inactivation of papain

    International Nuclear Information System (INIS)

    Baugher, J.F.; Grossweiner, L.I.

    1975-01-01

    Flash photolysis transient spectra (lambda > 250 nm) of aqueous papain showed that the initial products are the neutral tryptophan radical Trp (lambdasub(max) 510 nm), the tryptophan triplet state 3 Trp (lambdasub(max) 460 nm), the disulfide bridge electron adduct -SS - - (lambdasub(max) 420 nm) and the hydrated electron esub(aq) - . The -SS - - yield was not altered by nitrous oxide or air, indicating that the formation of this product does not involve electrons in the external medium. The original papain preparation was activated by irradiating under nitrogen. The action spectrum supports previous work attributing the low initial activity to blocking of cysteinyl site 25 with a mixed disulfide. Flask lamp irradiation in nitrogen led to activation at low starting activities and inactivation at higher starting activities, while only inactivation at the same quantum yield was observed with air saturation. The results are consistent with photoionization of an essential tryptophyl residue as the key inactivating step. (author)

  4. Protective Efficacy of Recombinant Turkey Herpes Virus (rHVT-H5) and Inactivated H5N1 Vaccines in Commercial Mulard Ducks against the Highly Pathogenic Avian Influenza (HPAI) H5N1 Clade 2.2.1 Virus.

    Science.gov (United States)

    Kilany, Walid H; Safwat, Marwa; Mohammed, Samy M; Salim, Abdullah; Fasina, Folorunso Oludayo; Fasanmi, Olubunmi G; Shalaby, Azhar G; Dauphin, Gwenaelle; Hassan, Mohammed K; Lubroth, Juan; Jobre, Yilma M

    2016-01-01

    In Egypt, ducks kept for commercial purposes constitute the second highest poultry population, at 150 million ducks/year. Hence, ducks play an important role in the introduction and transmission of avian influenza (AI) in the Egyptian poultry population. Attempts to control outbreaks include the use of vaccines, which have varying levels of efficacy and failure. To date, the effects of vaccine efficacy has rarely been determined in ducks. In this study, we evaluated the protective efficacy of a live recombinant vector vaccine based on a turkey Herpes Virus (HVT) expressing the H5 gene from a clade 2.2 H5N1 HPAIV strain (A/Swan/Hungary/499/2006) (rHVT-H5) and a bivalent inactivated H5N1 vaccine prepared from clade 2.2.1 and 2.2.1.1 H5N1 seeds in Mulard ducks. A 0.3ml/dose subcutaneous injection of rHVT-H5 vaccine was administered to one-day-old ducklings (D1) and another 0.5ml/dose subcutaneous injection of the inactivated MEFLUVAC was administered at 7 days (D7). Four separate challenge experiments were conducted at Days 21, 28, 35 and 42, in which all the vaccinated ducks were challenged with 106EID50/duck of H5N1 HPAI virus (A/chicken/Egypt/128s/2012(H5N1) (clade 2.2.1) via intranasal inoculation. Maternal-derived antibody regression and post-vaccination antibody immune responses were monitored weekly. Ducks vaccinated at 21, 28, 35 and 42 days with the rHVT-H5 and MEFLUVAC vaccines were protected against mortality (80%, 80%, 90% and 90%) and (50%, 70%, 80% and 90%) respectively, against challenges with the H5N1 HPAI virus. The amount of viral shedding and shedding rates were lower in the rHVT-H5 vaccine groups than in the MEFLUVAC groups only in the first two challenge experiments. However, the non-vaccinated groups shed significantly more of the virus than the vaccinated groups. Both rHVT-H5 and MEFLUVAC provide early protection, and rHVT-H5 vaccine in particular provides protection against HPAI challenge.

  5. Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation

    International Nuclear Information System (INIS)

    Elliott, L.H.; McCormick, J.B.; Johnson, K.M.

    1982-01-01

    Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with 60 CO gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log 50% tissue culture infective dose per rad of 60 CO radiation, as compared with 6.8 X 10(-6) log 50% tissue culture infective dose per rad for Ebola virus and 8.4 X 10(-6) log 50% tissue culture infective dose per rad for Marburg virus. Experimental inactivation curves, as well as curves giving the total radiation needed to inactivate a given concentration of any of the three viruses, are presented. The authors found this method of inactivation to be superior to UV light or beta-propiolactone inactivation and now routinely use it for preparation of material for protein-chemistry studies or for preparation of immunological reagents

  6. Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation

    International Nuclear Information System (INIS)

    Elliott, L.H.; McCormick, J.B.; Johnson, K.M.

    1982-01-01

    Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with 60 Co gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log 50% tissue culture infective dose per rad of 60 Co radiation, as compared with 6.8 X 10(-6) log 50% tissue culture infective dose per rad for Ebola virus and 8.4 X 10(-6) log 50% tissue culture infective dose per rad for Marburg virus. Experimental inactivation curves, as well as curves giving the total radiation needed to inactivate a given concentration of any of the three viruses, are presented. We found this method of inactivation to be superior to UV light or beta-propiolactone inactivation and now routinely use it for preparation of material for protein-chemistry studies or for preparation of immunological reagents

  7. Inactivation of RNA Viruses by Gamma Irradiation: A Study on Mitigating Factors

    Directory of Open Access Journals (Sweden)

    Adam J. Hume

    2016-07-01

    Full Text Available Effective inactivation of biosafety level 4 (BSL-4 pathogens is vital in order to study these agents safely. Gamma irradiation is a commonly used method for the inactivation of BSL-4 viruses, which among other advantages, facilitates the study of inactivated yet morphologically intact virions. The reported values for susceptibility of viruses to inactivation by gamma irradiation are sometimes inconsistent, likely due to differences in experimental protocols. We analyzed the effects of common sample attributes on the inactivation of a recombinant vesicular stomatitis virus expressing the Zaire ebolavirus glycoprotein and green fluorescent protein. Using this surrogate virus, we found that sample volume and protein content of the sample modulated viral inactivation by gamma irradiation but that air volume within the sample container and the addition of external disinfectant surrounding the sample did not. These data identify several factors which alter viral susceptibility to inactivation and highlight the usefulness of lower biosafety level surrogate viruses for such studies. Our results underscore the need to validate inactivation protocols of BSL-4 pathogens using “worst-case scenario” procedures to ensure complete sample inactivation.

  8. Opportunities for optimization: fate of manure-borne pathogens during anaerobic digestion and solids separation

    Science.gov (United States)

    Anaerobic digestion can inactivate zoonotic pathogens present in cattle manure, which reduces transmission of these pathogens from farms to humans through the environment. However, the variability in extent of inactivation across farms and over time is unknown because most studies have examined pat...

  9. Photoinactivation of major bacterial pathogens in aquaculture

    Directory of Open Access Journals (Sweden)

    Heyong Jin Roh

    2016-08-01

    Full Text Available Abstract Background Significant increases in the bacterial resistance to various antibiotics have been found in fish farms. Non-antibiotic therapies for infectious diseases in aquaculture are needed. In recent years, light-emitting diode technology has been applied to the inactivation of pathogens, especially those affecting humans. The purpose of this study was to assess the effect of blue light (wavelengths 405 and 465 nm on seven major bacterial pathogens that affect fish and shellfish important in aquaculture. Results We successfully demonstrate inactivation activity of a 405/465-nm LED on selected bacterial pathogens. Although some bacteria were not fully inactivated by the 465-nm light, the 405-nm light had a bactericidal effect against all seven pathogens, indicating that blue light can be effective without the addition of a photosensitizer. Photobacterium damselae, Vibrio anguillarum, and Edwardsiella tarda were the most susceptible to the 405-nm light (36.1, 41.2, and 68.4 J cm−2, respectively, produced one log reduction in the bacterial populations, whereas Streptococcus parauberis was the least susceptible (153.8 J cm−2 per one log reduction. In general, optical density (OD values indicated that higher bacterial densities were associated with lower inactivating efficacy, with the exception of P. damselae and Vibrio harveyi. In conclusion, growth of the bacterial fish and shellfish pathogens evaluated in this study was inactivated by exposure to either the 405- or 465-nm light. In addition, inactivation was dependent on exposure time. Conclusions This study presents that blue LED has potentially alternative therapy for treating fish and shellfish bacterial pathogens. It has great advantages in aspect of eco-friendly treating methods differed from antimicrobial methods.

  10. Immune response in domestic ducks following intradermal delivery of inactivated vaccine against H5N1 highly pathogenic avian influenza virus adjuvanted with oligodeoxynucleotides containing CpG motifs.

    Science.gov (United States)

    Yuk, Seong-Su; Lee, Dong-Hun; Park, Jae-Keun; To, Eredene-Ochir; Kwon, Jung-Hoon; Noh, Jin-Yong; Gomis, Susantha; Song, Chang-Seon

    2015-08-01

    Ducks are a natural reservoir for H5N1 highly pathogenic avian influenza (HPAI) viruses, which produces a range of clinical outcomes from asymptomatic infections to severe disease with mortality. Vaccination against HPAI is one of the few methods available for controlling avian influenza virus (AIV) infection in domestic ducks; therefore, it is necessary to improve vaccine efficacy against HPAI in domestic ducks. However, few studies have focused on enhancing the immune response by testing alternative administration routes and adjuvants. While attempting to maximize the efficacy of a vaccine, it is important to select an appropriate vaccine delivery route and adjuvant to elicit an enhanced immune response. Although several studies have indicated that the vaccination of ducks against HPAI viruses has offered protection against lethal virus challenge, the immunogenicity of the vaccine still requires improvement. In this study, we characterized the immune response following a novel vaccination strategy against H5N1 HPAI virus in domestic ducks. Our novel intradermal delivery system and the application of the cytosine-phosphodiester-guanine (CpG) oligodeoxynucleotide (ODN) adjuvant allowed us to obtain information regarding the sustained vaccine immunity. Compared with the intramuscular route of vaccination, the intradermal route resulted in higher antibody titer as well as lower antibody deviation following secondary vaccination. In addition, the use of a CpG-ODN adjuvant had a dose-sparing effect on antibody titer. Furthermore, when a high dose of antigen was used, the CpG-ODN-adjuvanted vaccine maintained a high mean antibody titer. This data demonstrates that intradermal immunization combined with administration of CpG-ODN as an adjuvant may be a promising strategy for improving vaccine efficacy in domestic ducks. © 2015 Poultry Science Association Inc.

  11. Inactivation of Listeria monocytogenes in milk by pulsed electric field.

    Science.gov (United States)

    Reina, L D; Jin, Z T; Zhang, Q H; Yousef, A E

    1998-09-01

    Pasteurized whole, 2%, and skim milk were inoculated with Listeria monocytogenes Scott A and treated with high-voltage pulsed electric field (PEF). The effects of milk composition (fat content) and PEF parameters (electric field strength, treatment time, and treatment temperature) on the inactivation of the bacterium were studied. No significant differences were observed in the inactivation of L. monocytogenes Scott A in three types of milk by PEF treatment. With treatment at 25 degrees C, 1- to 3-log reductions of L. monocytogenes were observed. PEF lethal effect was a function of field strength and treatment time. Higher field strength or longer treatment time resulted in a greater reduction of viable cells. A 4-log reduction of the bacterium was obtained by increasing the treatment temperature to 50 degrees C. Results indicate that the use of a high-voltage PEF is a promising technology for inactivation of foodborne pathogens.

  12. Evaluation of Filtration and UV Disinfection for Inactivation of Viruses in Non-Community Water Systems in Minnesota

    Science.gov (United States)

    This study evaluated filtration and disinfection processes for removal and inactivation of pathogens in non-community water systems (NCWS) in two surface water supplies. Pretreatment systems included 1) pressure sand filtration, and 2) granular activated carbon adsorption, and 3...

  13. Free radical inactivation of trypsin

    International Nuclear Information System (INIS)

    Cudina, Ivana; Jovanovic, S.V.

    1988-01-01

    Reactivities of free radical oxidants, radical OH, Br2-anion radical and Cl 3 COO radical and a reductant, CO2-anion radical, with trypsin and reactive protein components were determined by pulse radiolysis of aqueous solutions at pH 7, 20 0 C. Highly reactive free radicals, radical OH, Br2-anion radical and CO2-anion radical, react with trypsin at diffusion controlled rates. Moderately reactive trichloroperoxy radical, k(Cl 3 COO radical + trypsin) preferentially oxidizes histidine residues. The efficiency of inactivation of trypsin by free radicals is inversely proportional to their reactivity. The yields of inactivation of trypsin by radical OH, Br2-anion radical and CO2-anion radical are low, G(inactivation) = 0.6-0.8, which corresponds to ∼ 10% of the initially produced radicals. In contrast, Cl 3 COO radical inactivates trypsin with ∼ 50% efficiency, i.e. G(inactivation) = 3.2. (author)

  14. Sunlight inactivation of Escherichia coli in waste stabilization microcosms in a sahelian region (Ouagadougou, Burkina Faso).

    Science.gov (United States)

    Maïga, Ynoussa; Denyigba, Kokou; Wethe, Joseph; Ouattara, Aboubakar Sidiki

    2009-02-09

    Experiments on sunlight inactivation of Escherichia coli were conducted from November 2006 to June 2007 in eight outdoors microcosms with different depths filled with maturation pond wastewater in order to determine pond depth influence on sunlight inactivation of E. coli. The long-term aim was to maximize sunlight inactivation of waterborne pathogens in waste stabilization ponds (WSPs) in sahelian regions where number of sunny days enable longer exposure of wastewater to sunlight. The inactivation was followed during daylight from 8.00 h to 17.00 h and during the night. Sunlight inactivation rates (K(S)), as a function of cumulative global solar radiation (insolation), were 16 and 24 times higher than the corresponding dark inactivation (K(D)) rates, respectively in cold and warm season. In warm season, E. coli was inactivated far more rapidly. Inactivation of E. coli follows the evolution of radiation during the day. In shallow depth microcosms, E. coli was inactivated far more rapidly than in high depth microcosms. The physical chemical parameters [pH, dissolved oxygen (DO)] of microcosms water were higher in shallow depth microcosms than in high depth microcosms suggesting a synergistic effect of sunlight and these parameters to damage E. coli. To increase the efficiency of the elimination of waterborne bacteria, the use of maturation ponds with intermediate depths (0.4m) would be advisable in view of the high temperatures and thus evaporation recorded in sahelian regions.

  15. Inactivation of Microorganisms

    Science.gov (United States)

    Alzamora, Stella Maris; Guerrero, Sandra N.; Schenk, Marcela; Raffellini, Silvia; López-Malo, Aurelio

    Minimal processing techniques for food preservation allow better retention of product flavor, texture, color, and nutrient content than comparable conventional treatments. A wide range of novel alternative physical factors have been intensely investigated in the last two decades. These physical factors can cause inactivation of microorganisms at ambient or sublethal temperatures (e.g., high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed light, and ultraviolet light). These technologies have been reported to reduce microorganism population in foods while avoiding the deleterious effects of severe heating on quality. Among technologies, high-energy ultrasound (i.e., intensities higher than 1 W/cm2, frequencies between 18 and 100 kHz) has attracted considerable interest for food preservation applications (Mason et al., 1996; Povey and Mason, 1998).

  16. Mean inactivation dose (D)

    International Nuclear Information System (INIS)

    Vijayakumar, S.; Ng, T.C.; Raudkivi, U.; Meaney, T.J.

    1990-01-01

    By predicting treatment outcome to radiotherapy from in vitro radiobiological parameters, not only individual patient treatments can be tailored, but also new promising treatment protocols can be tried in patients in whom unfavorable outcome is predicted. In this respect, choosing the right parameter can be very important. Unlike D 0 and N which provide information of the distal part of the survival curve, mean inactivation dose (D) estimates overall radiosensitivity. However, the parameters reflecting the response at the clinically relevant low-dose region are neglected in the literature. In a literature survey of 98 papers in which survival curves or D 0 /N were used, only in 2 D was used. In 21 papers the D 0 /n values were important in drawing conclusions. By calculating D in 3 of these 21 papers, we show that the conclusion drawn may be altered with the use of D. The importance of ''low-dose-region-parameters'' is reviewed. (orig.)

  17. Thermal Inactivation of avian influenza virus in poultry litter as a method to decontaminate poultry houses.

    Science.gov (United States)

    Stephens, Christopher B; Spackman, Erica

    2017-09-15

    Removal of contaminated material from a poultry house during recovery from an avian influenza virus (AIV) outbreak is costly and labor intensive. Because AIV is not environmentally stable, heating poultry houses may provide an alternative disinfection method. The objective was to determine the time necessary to inactivate AIV in poultry litter at temperatures achievable in a poultry house. Low pathogenic (LP) AIV inactivation was evaluated between 10.0°-48.9°C, at ∼5.5°C intervals and highly pathogenic (HP) AIV inactivation was evaluated between 10.0°-43.3°C, at ∼11°C intervals. Samples were collected at numerous time points for each temperature. Virus isolation in embryonating chicken eggs was conducted to determine if viable virus was present. Each sample was also tested by real-time RT-PCR. Low pathogenicity AIV was inactivated at 1day at 26.7°C or above. At 10.0, 15.6 and 21.1°C, inactivation times increased to 2-5days. Highly pathogenic AIV followed a similar trend; the virus was inactivated after 1day at 43.3°C and 32.2°C, and required 2 and 5days for inactivation at 21.1°C and 10.0°C respectively. While low pathogenicity AIV appeared to be inactivated at a lower temperature than high pathogenicity AIV, this was not due to any difference in the strains, but due to fewer temperature points being evaluated for high pathogenicity. Endpoints for detection by real-time RT-PCR were not found even weeks after the virus was inactivated. This provides a guideline for the time required, at specific temperatures to inactivate AIV in poultry litter and likely on surfaces within the house. Heat treatment will provide an added level of safety to personnel and against further spread by eliminating infectious virus prior to cleaning a house. Published by Elsevier B.V.

  18. Inactivation of Giardia muris cysts by free chlorine.

    OpenAIRE

    Leahy, J G; Rubin, A J; Sproul, O J

    1987-01-01

    The chlorine resistance of cysts of the flagellate protozoan Giardia muris was examined. This organism, which is pathogenic to mice, is being considered as a model for the inactivation of the human pathogen Giardia lamblia. Excystation was used as the criterion for cyst viability. Experiments were performed at pH 5, 7, and 9 at 25 degrees C and pH 7 at 5 degrees C. Survival curves were "stepladder"-shaped, but concentration-time data generally conformed to Watson's Law. Chlorine was most effe...

  19. Physiological functions and pathogenic potential of uric acid: A review.

    Science.gov (United States)

    El Ridi, Rashika; Tallima, Hatem

    2017-09-01

    Uric acid is synthesized mainly in the liver, intestines and the vascular endothelium as the end product of an exogenous pool of purines, and endogenously from damaged, dying and dead cells, whereby nucleic acids, adenine and guanine, are degraded into uric acid. Mentioning uric acid generates dread because it is the established etiological agent of the severe, acute and chronic inflammatory arthritis, gout and is implicated in the initiation and progress of the metabolic syndrome. Yet, uric acid is the predominant anti-oxidant molecule in plasma and is necessary and sufficient for induction of type 2 immune responses. These properties may explain its protective potential in neurological and infectious diseases, mainly schistosomiasis. The pivotal protective potential of uric acid against blood-borne pathogens and neurological and autoimmune diseases is yet to be established.

  20. Damage mechanisms of pathogenic bacteria in drinking water ...

    African Journals Online (AJOL)

    This study aimed at elucidating the inactivation mechanisms of pathogenic bacteria in drinking water during chlorine and solar disinfection using a simple plating method. The well-known bacterial model Escherichia coli was used as pathogenic bacteria for the experiments. The damage mechanisms of E. coli were ...

  1. Online interventions to address HIV and other sexually transmitted and blood-borne infections among young gay, bisexual and other men who have sex with men: a systematic review.

    Science.gov (United States)

    Knight, Rod; Karamouzian, Mohammad; Salway, Travis; Gilbert, Mark; Shoveller, Jean

    2017-11-01

    Globally, young gay, bisexual and other men who have sex with men (gbMSM) continue to experience disproportionately high rates of HIV and other sexually transmitted and blood-borne infections (STBBIs). As such, there are strong public health imperatives to evaluate innovative prevention, treatment and care interventions, including online interventions. This study reviewed and assessed the status of published research (e.g. effectiveness; acceptability; differential effects across subgroups) involving online interventions that address HIV/STBBIs among young gbMSM. We searched Medline, Embase, PsycINFO, CINAHL, and Google Scholar to identify relevant English-language publications from inception to November 2016. Studies that assessed an online intervention regarding the prevention, care, or treatment of HIV/STBBIs were included. Studies with gay and bisexual men; four studies did not assess sexual identity. Two studies reported including both HIV+ and HIV- participants, and all but one study included one or more measure of socio-economic status. Few studies reported on the differential intervention effects by socio-economic status, sexual identity, race or serostatus. While online interventions show promise at addressing HIV/STBBI among young gbMSM, to date, little emphasis has been placed on assessing: (i) potential differential effects of interventions across subgroups of young gbMSM; (ii) effectiveness studies of interventions in the dissemination phase; and (iii) on some "key" populations of young gbMSM (e.g. those who are: transgender, from low-income settings and/or HIV positive). Future research that unpacks the potentially distinctive experiences of particular subgroups with "real world" interventions is needed. © 2017 The Authors. Journal of the International AIDS Society published by John Wiley & sons Ltd on behalf of the International AIDS Society.

  2. Rapid and preferential distribution of blood-borne αCD3εAb to the liver is followed by local stimulation of T cells and natural killer T cells

    Science.gov (United States)

    Wingender, Gerhard; Schumak, Beatrix; Schurich, Anna; Gessner, J Engelbert; Endl, Elmar; Limmer, Andreas; Knolle, Percy A

    2006-01-01

    Dissemination of soluble molecules or antigens via the blood stream is considered to lead to a uniform distribution in the various organs of the body, but organ-specific microarchitecture and vascularization may influence this. Following intravenous injection of αCD3ε antibody (αCD3εAb) we observed clear differences in antibody binding to Fcγ receptor (FcγR)+ antigen-presenting cells (APCs) or T lymphocytes in different organs. Significant binding of blood-borne αCD3εAb was only detected in the spleen and liver and not in the thymus or lymph node. In the spleen, only 10% of dendritic cells/macrophages and 40% of T-cell receptor (TCR)-β+ cells were positive for αCD3εAb, and, dependent on FcγR-mediated cross-linking of αCD3εAb, a similar percentage of splenic TCR-β+ cells were stimulated and became CD69+. Stimulation of TCR-β+ cells in the liver was at least as efficient as in the spleen, but almost all T cells and all scavenger liver sinusoidal endothelial cells bound αCD3εAb. In contrast to CD69 up-regulation, only CD4+ natural killer T (NKT) cells and CD11ahigh CD8+ T cells were activated by αCD3εAb and expressed interferon (IFN)-γ. Again, IFN-γ release from NKT/T cells was at least as efficient in the liver as in the spleen. Taken together, our results support the notion that the combination of extensive hepatic vascularization and very high scavenger activity allows the liver to fulfill its metabolic tasks and to promote stimulation of the large but widely distributed hepatic population of NKT/T cells. PMID:16423047

  3. Inactivation kinetics and efficiencies of UV-LEDs against Pseudomonas aeruginosa, Legionella pneumophila, and surrogate microorganisms.

    Science.gov (United States)

    Rattanakul, Surapong; Oguma, Kumiko

    2018-03-01

    To demonstrate the effectiveness of UV light-emitting diodes (UV-LEDs) to disinfect water, UV-LEDs at peak emission wavelengths of 265, 280, and 300 nm were adopted to inactivate pathogenic species, including Pseudomonas aeruginosa and Legionella pneumophila, and surrogate species, including Escherichia coli, Bacillus subtilis spores, and bacteriophage Qβ in water, compared to conventional low-pressure UV lamp emitting at 254 nm. The inactivation profiles of each species showed either a linear or sigmoidal survival curve, which both fit well with the Geeraerd's model. Based on the inactivation rate constant, the 265-nm UV-LED showed most effective fluence, except for with E. coli which showed similar inactivation rates at 265 and 254 nm. Electrical energy consumption required for 3-log 10 inactivation (E E,3 ) was lowest for the 280-nm UV-LED for all microbial species tested. Taken together, the findings of this study determined the inactivation profiles and kinetics of both pathogenic bacteria and surrogate species under UV-LED exposure at different wavelengths. We also demonstrated that not only inactivation rate constants, but also energy efficiency should be considered when selecting an emission wavelength for UV-LEDs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Evaluation of an antimicrobial surgical glove to inactivate live human immunodeficiency virus following simulated glove puncture.

    Science.gov (United States)

    Edmiston, Charles E; Zhou, S Steve; Hoerner, Pierre; Krikorian, Raffi; Krepel, Candace J; Lewis, Brian D; Brown, Kellie R; Rossi, Peter J; Graham, Mary Beth; Seabrook, Gary R

    2013-02-01

    Percutaneous injuries associated with cutting instruments, needles, and other sharps (eg, metallic meshes, bone fragments, etc) occur commonly during surgical procedures, exposing members of surgical teams to the risk for contamination by blood-borne pathogens. This study evaluated the efficacy of an innovative integrated antimicrobial glove to reduce transmission of the human immunodeficiency virus (HIV) following a simulated surgical-glove puncture injury. A pneumatically activated puncturing apparatus was used in a surgical-glove perforation model to evaluate the passage of live HIV-1 virus transferred via a contaminated blood-laden needle, using a reference (standard double-layer glove) and an antimicrobial benzalkonium chloride (BKC) surgical glove. The study used 2 experimental designs. In method A, 10 replicates were used in 2 cycles to compare the mean viral load following passage through standard and antimicrobial gloves. In method B, 10 replicates were pooled into 3 aliquots and were used to assess viral passage though standard and antimicrobial test gloves. In both methods, viral viability was assessed by observing the cytopathic effects in human lymphocytic C8166 T-cell tissue culture. Concurrent viral and cell culture viability controls were run in parallel with the experiment's studies. All controls involving tissue culture and viral viability were performed according to study design. Mean HIV viral loads (log(10)TCID(50)) were significantly reduced (P reduction (log reduction and percent viral reduction) of the HIV virus ranged from 1.96 to 2.4 and from 98.9% to 99.6%, respectively, following simulated surgical-glove perforation. Sharps injuries in the operating room pose a significant occupational risk for surgical practitioners. The findings of this study suggest that an innovative antimicrobial glove was effective at significantly (P < .01) reducing the risk for blood-borne virus transfer in a model of simulated glove perforation. Copyright

  5. Inactivation of human pathogenic dermatophytes by non-thermal plasma

    Czech Academy of Sciences Publication Activity Database

    Scholtz, V.; Soušková, H.; Hubka, Vít; Švarcová, M.; Julák, J.

    2015-01-01

    Roč. 119, DEC 2015 (2015), s. 53-58 ISSN 0167-7012 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 Keywords : Corona discharge * Cometary discharge * Decontamination of surfaces Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.857, year: 2015

  6. Infectious Causes of Cholesteatoma and Treatment of Infected Ossicles prior to Reimplantation by Hydrostatic High-Pressure Inactivation

    Science.gov (United States)

    Hinz, Rebecca

    2015-01-01

    Chronic inflammation, which is caused by recurrent infections, is one of the factors contributing to the pathogenesis of cholesteatoma. If reimplantation of autologous ossicles after a surgical intervention is intended, inactivation of planktonic bacteria and biofilms is desirable. High hydrostatic pressure treatment is a procedure, which has been used to inactivate cholesteatoma cells on ossicles. Here we discuss the potential inactivating effect of high hydrostatic pressure on microbial pathogens including biofilms. Recent experimental data suggest an incomplete inactivation at a pressure level, which is tolerable for the bone substance of ossicles and results at least in a considerable reduction of pathogen load. Further studies are necessary to access how far this quantitative reduction of pathogens is sufficient to prevent ongoing chronic infections, for example, due to forming of biofilms. PMID:25705686

  7. Development of inactivated-local isolate vaccine for infectious bronchitis

    Directory of Open Access Journals (Sweden)

    Darminto

    1999-06-01

    Full Text Available Infectious bronchitis (IB is an acute highly contagious viral respiratory disease of poultry caused by coronavirus. The disease causes high mortality in young chicks, reduce body weight gain in broilers and remarkable drop in egg production. IB can only be controlled by vaccination, but due to the antigenic variation among serotypes of IB viruses, the effective IB vaccine should be prepared from local isolates. The aim of this research is to develop inactivated IB vaccine derived from local IB isolates. Local isolates of IB viruses designated as I-37, I-269 and PTS-III were propagated respectively in specific pathogen free (SPF chicken eggs, the viruses then were inactivated by formaline at final concentration of 1:1,000. Subsequently, the inactivated viruses were mixed and emulsified in oil emulsion adjuvant with sorbitant mono-oleic as an emulsifier. The vaccine then was tested for its safety, potency and efficacy in broiler chickens. Birds inoculated twice with a two-week interval by inactivated vaccine did not show any adverse reaction, either systemic or local reaction. The inoculated birds developed antibody responses with high titre, while antibody of the control birds remain negative. In addition, efficacy test which was conducted in broilers demonstrated that birds vaccinated by live-commercial vaccine and boosted three weeks later by Balitvet inactivated vaccine showed high level of antibody production which provided high level of protection against challenged virus (76% against I-37, 92% against I-269 and 68% against PTS-III challenge viruses. From this study, it can be concluded that inactivated local IB vaccine is considered to be safe, potent and efficacious. The vaccine stimulates high titre of antibody responses, which provide high level of protection against challenged viruses.

  8. In vitro photoinactivation of bovine mastitis related pathogens.

    Science.gov (United States)

    Sellera, Fábio Parra; Sabino, Caetano Padial; Ribeiro, Martha Simões; Gargano, Ronaldo Gomes; Benites, Nilson Roberti; Melville, Priscilla Anne; Pogliani, Fabio Celidonio

    2016-03-01

    Bovine mastitis is considered the most important disease of worldwide dairy industry. Treatment of this disease is based on the application intramammary antibiotic, which favors an increase in the number of resistant bacteria in the last decade. Photodynamic inactivation (PDI) has been investigated in different areas of Health Sciences, and has shown great potential for inactivating different pathogens, without any selection of resistant microorganisms. The objective of this study was to investigate the efficacy of PDI in the inactivation of pathogens associated with bovine mastitis. We tested the effectiveness of PDI against antibiotic resistant strains, isolated from bovine mastitis, from the following species: Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Corynebacterium bovis, and the alga Prototheca zopfii. Nine experimental groups were evaluated: control, no treatment; light only, irradiation of a red light-emitting diode (λ=662 (20) nm) for 180 s; exposure to 50 μM methylene blue alone for 5 min; and PDI for 5, 10, 30, 60, 120 and 180 s. S. dysgalactiae, S. aureus, and C. bovis were inactivated after 30s of irradiation, whereas S. agalactiae was inactivated after 120 s and P. zopfii at 180 s of irradiation. These results show that PDI can be an interesting tool for inactivating pathogens for bovine mastitis. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Inactivation of microorganisms for high pressures in the wine industry

    International Nuclear Information System (INIS)

    Montana B, Jaime Nelson; Ortegon T, Sandra Patricia

    2000-01-01

    In order to evaluate experimentally the capacity of N 2 and CO 2 under pressure to inactivate wild yeasts, which remain in the Puntalarga vineyard grape, musts were exposed to hyperbaric treatment with these gases. At the end of the pascalization (after 2 hours), CO 2 at 15 degrades Celsius under pressures from 1 to 5 MPa, reached high inactivation percentages of yeast cells (> 90%). Contrary to CO 2 treatment the use of N 2 at 15 degrades Celsius at 4 and 10 MPa failed to exert microbicide effect in a same treatment time. While CO 2 gas with high solubility in water has the potential to reduce microbial loads in musts, N 2 gas with low solubility in water have not effect on the survival of the pathogenic microorganisms in these juices

  10. Viral inactivation in hemotherapy: systematic review on inactivators with action on nucleic acids

    Directory of Open Access Journals (Sweden)

    Patricia Marial Sobral

    2012-01-01

    Full Text Available The aim of this study was to conduct a systematic review on the photoinactivators used in hemotherapy, with action on viral genomes. The SciELO, Science Direct, PubMed and Lilacs databases were searched for articles. The inclusion criterion was that these should be articles on inactivators with action on genetic material that had been published between 2000 and 2010. The key words used in identifying such articles were "hemovigilance", "viral inactivation", "photodynamics", "chemoprevention" and "transfusion safety". Twenty-four articles on viral photoinactivation were found with the main photoinactivators covered being: methylene blue, amotosalen HCl, S-303 frangible anchor linker effector (FRALE, riboflavin and inactin. The results showed that methylene blue has currently been studied least, because it diminishes coagulation factors and fibrinogen. Riboflavin has been studied most because it is a photoinactivator of endogenous origin and has few collateral effects. Amotosalen HCl is effective for platelets and is also used on plasma, but may cause changes both to plasma and to platelets, although these are not significant for hemostasis. S-303 FRALE may lead to neoantigens in erythrocytes and is less indicated for red-cell treatment; in such cases, PEN 110 is recommended. Thus, none of the methods for pathogen reduction is effective for all classes of agents and for all blood components, but despite the high cost, these photoinactivators may diminish the risk of blood-transmitted diseases.

  11. Capsid protein oxidation in feline calicivirus using an electrochemical inactivation treatment

    Energy Technology Data Exchange (ETDEWEB)

    Shionoiri, Nozomi; Nogariya, Osamu; Tanaka, Masayoshi; Matsunaga, Tadashi; Tanaka, Tsuyoshi, E-mail: tsuyo@cc.tuat.ac.jp

    2015-02-11

    Highlights: • Feline calicivirus was inactivated electrochemically by a factor of >5 log. • The electrochemical treatment was performed at 0.9 V (vs. Ag/AgCl) for 15 min. • Electrochemical treatment caused oxidation of viral proteins. • Oxidation of viral proteins can lead to loss of viral structural integrity. - Abstract: Pathogenic viral infections are an international public health concern, and viral disinfection has received increasing attention. Electrochemical treatment has been used for treatment of water contaminated by bacteria for several decades, and although in recent years several reports have investigated viral inactivation kinetics, the mode of action of viral inactivation by electrochemical treatment remains unclear. Here, we demonstrated the inactivation of feline calicivirus (FCV), a surrogate for human noroviruses, by electrochemical treatment in a developed flow-cell equipped with a screen-printed electrode. The viral infectivity titer was reduced by over 5 orders of magnitude after 15 min of treatment at 0.9 V vs. Ag/AgCl. Proteomic study of electrochemically inactivated virus revealed oxidation of peptides located in the viral particles; oxidation was not observed in the non-treated sample. Furthermore, transmission electron microscopy revealed that viral particles in the treated sample had irregular structures. These results suggest that electrochemical treatment inactivates FCV via oxidation of peptides in the structural region, causing structural deformation of virus particles. This first report of viral protein damage through electrochemical treatment will contribute to broadening the understanding of viral inactivation mechanisms.

  12. Pathogen Decontamination of Food Crop Soil: A Review.

    Science.gov (United States)

    Gurtler, Joshua B

    2017-09-01

    The purpose of this review is to delineate means of decontaminating soil. This information might be used to mitigate soil-associated risks of foodborne pathogens. The majority of the research in the published literature involves inactivation of plant pathogens in soil, i.e., those pathogens harmful to fruit and vegetable production and ornamental plants. Very little has been published regarding the inactivation of foodborne human pathogens in crop soil. Nevertheless, because decontamination techniques for plant pathogens might also be useful methods for eliminating foodborne pathogens, this review also includes inactivation of plant pathogens, with appropriate discussion and comparisons, in the hopes that these methods may one day be validated against foodborne pathogens. Some of the major soil decontamination methods that have been investigated and are covered include chemical decontamination (chemigation), solarization, steaming, biofumigation, bacterial competitive exclusion, torch flaming, microwave treatment, and amendment with biochar. Other innovative means of inactivating foodborne pathogens in soils may be discovered and explored in the future, provided that these techniques are economically feasible in terms of chemicals, equipment, and labor. Food microbiology and food safety researchers should reach out to soil scientists and plant pathologists to create links where they do not currently exist and strengthen relationships where they do exist to take advantage of multidisciplinary skills. In time, agricultural output and the demand for fresh produce will increase. With advances in the sensitivity of pathogen testing and epidemiological tracebacks, the need to mitigate preharvest bacterial contamination of fresh produce will become paramount. Hence, soil decontamination technologies may become more economically feasible and practical in light of increasing the microbial safety of fresh produce.

  13. Inactivation of E.coli 0157:H7 and Salmonella enterica on strawberries by sanitizing solutions

    Science.gov (United States)

    A recent foodborne outbreak of E. coli O157:H7 in Oregon associated with the consumption of fresh strawberries highlights the need for effective sanitizing washes, suitable for the inactivation of pathogens on fresh produce. Sanitizing solutions were screened for decontaminating E. coli O157:H7 (E...

  14. Inactivation of Escherichia coli on blueberries using cold plasma with chemical augmentation inside a partial vacuum

    Science.gov (United States)

    Justification: The mechanism by which cold plasma inactivates pathogens is through the production of free reactive chemical species. Unfortunately, the most reactive chemical species have the shortest half-life. In a vacuum their half-life is believed to be prolonged. Additionally, these reactive sp...

  15. Solar Radiation Disinfection of Drinking Water at Temperate Latitudes: Inactivation rates for an optimized reactor configuration

    Science.gov (United States)

    Solar radiation-driven inactivation of bacteria, virus and protozoan pathogen models was quantified in simulated drinking water at a temperate latitude (34°S). The water was seeded with Enterococcus faecalis, Clostridium sporogenes spores, and P22 bacteriophage, each at ca 1 x 10...

  16. Hot water surface pasteurization for inactivating Salmonella on surfaces of mature green tomatoes

    Science.gov (United States)

    Outbreaks of salmonellosis have been associated with the consumption of tomatoes contaminated with Salmonella. Commercial washing processes for tomatoes are limited in their ability to inactivate and/or remove this human pathogen. Our objective was to develop a hot water surface pasteurization pro...

  17. Pathogen intelligence

    Directory of Open Access Journals (Sweden)

    Michael eSteinert

    2014-01-01

    Full Text Available Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behaviour, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behaviour, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies.

  18. Inactivation of bacteria by electric current in the presence of carbon nanotubes embedded within a polymeric membrane.

    Science.gov (United States)

    Zhu, Anna; Liu, Harris K; Long, Feng; Su, Erzheng; Klibanov, Alexander M

    2015-01-01

    Uniform conductive composite membranes were prepared using a phase inversion method by blending carboxyl-functionalized multi-walled carbon nanotubes (CNTs) with a polysulfone polymer. At 6 % of the embedded CNTs, the membrane pore size measured by transmission electron microscopy (TEM) was approximately 50 nm. Electric current in the presence of the composite membranes markedly inactivated the model pathogenic bacteria Escherichia coli and Staphylococcus aureus, with the extent of bacterial inactivation rising when the current was increased. Over 99.999 % inactivation of both bacteria was observed in deionized water after 40 min at 5 mA direct current (DC); importantly, no appreciable inactivation occurred in the absence of either the electric field or the CNTs within the membranes under otherwise the same conditions. A much lower, although still pronounced, inactivation was seen with alternating current (AC) in a 25 mM NaCl aqueous solution.

  19. Modeling of pathogen survival during simulated gastric digestion.

    Science.gov (United States)

    Koseki, Shige; Mizuno, Yasuko; Sotome, Itaru

    2011-02-01

    The objective of the present study was to develop a mathematical model of pathogenic bacterial inactivation kinetics in a gastric environment in order to further understand a part of the infectious dose-response mechanism. The major bacterial pathogens Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella spp. were examined by using simulated gastric fluid adjusted to various pH values. To correspond to the various pHs in a stomach during digestion, a modified logistic differential equation model and the Weibull differential equation model were examined. The specific inactivation rate for each pathogen was successfully described by a square-root model as a function of pH. The square-root models were combined with the modified logistic differential equation to obtain a complete inactivation curve. Both the modified logistic and Weibull models provided a highly accurate fitting of the static pH conditions for every pathogen. However, while the residuals plots of the modified logistic model indicated no systematic bias and/or regional prediction problems, the residuals plots of the Weibull model showed a systematic bias. The modified logistic model appropriately predicted the pathogen behavior in the simulated gastric digestion process with actual food, including cut lettuce, minced tuna, hamburger, and scrambled egg. Although the developed model enabled us to predict pathogen inactivation during gastric digestion, its results also suggested that the ingested bacteria in the stomach would barely be inactivated in the real digestion process. The results of this study will provide important information on a part of the dose-response mechanism of bacterial pathogens.

  20. Modeling of Pathogen Survival during Simulated Gastric Digestion ▿

    Science.gov (United States)

    Koseki, Shige; Mizuno, Yasuko; Sotome, Itaru

    2011-01-01

    The objective of the present study was to develop a mathematical model of pathogenic bacterial inactivation kinetics in a gastric environment in order to further understand a part of the infectious dose-response mechanism. The major bacterial pathogens Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella spp. were examined by using simulated gastric fluid adjusted to various pH values. To correspond to the various pHs in a stomach during digestion, a modified logistic differential equation model and the Weibull differential equation model were examined. The specific inactivation rate for each pathogen was successfully described by a square-root model as a function of pH. The square-root models were combined with the modified logistic differential equation to obtain a complete inactivation curve. Both the modified logistic and Weibull models provided a highly accurate fitting of the static pH conditions for every pathogen. However, while the residuals plots of the modified logistic model indicated no systematic bias and/or regional prediction problems, the residuals plots of the Weibull model showed a systematic bias. The modified logistic model appropriately predicted the pathogen behavior in the simulated gastric digestion process with actual food, including cut lettuce, minced tuna, hamburger, and scrambled egg. Although the developed model enabled us to predict pathogen inactivation during gastric digestion, its results also suggested that the ingested bacteria in the stomach would barely be inactivated in the real digestion process. The results of this study will provide important information on a part of the dose-response mechanism of bacterial pathogens. PMID:21131530

  1. Thermal inactivation of Phytophthora capsici oospores.

    Science.gov (United States)

    Etxeberria, Aitzol; Mendarte, Sorkunde; Larregla, Santiago

    2011-01-01

    Phytophthora capsici is a major fungal plant pathogen that causes root and crown rot of pepper crops and its oospores are the most resistant propagules. To evaluate the effect of different temperature regimes and exposure times on the survival of P. capsici oospores. Thermal inactivation treatments simulated field conditions, through the use of different constant and cycling temperature regimes, in moistened sterilized soil (15-53 °C) and sterilized water (45-53 °C). The plasmolysis method evaluated oospore viability. Relationships between oospores viability and exposure time were statistically determined by linear regression. Interpolation was used to calculate the estimated times required to kill a determined percentage of the population. The required time to reduce P. capsici oospores viability decreased with increasing temperatures. Times required to kill 100% of oospores were 199-22-6.6-4.7-1.0 hours at 40-45-47.5-50-53°C respectively in moistened soil and 31-1.0-0.2 hours at 45-50-53 °C in water. Oospores were scarcely affected at temperatures ≤ 35 °C. With 1,680 hours at 15-35 °C, oospores survival in soil ranged from 88 to 36%. The 4 hours-40 °C regime killed 100% of oospores after 28days, while the 5 hours-35°C regime after 70 days killed only 75%. Time required to achieve total oospores death was remarkably shortened in water when compared with moistened soil. The developed models can be used to predict survival values at any exposure time with constant temperatures ranging from 40 to 53 °C in moistened soil and from 45 to 53 °C in water. The weakening of P. capsici oospores under sublethal heating, is a useful observation that can be applied for pathogen control with solarization. Copyright © 2010 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  2. Influenza Vaccination Strategies: Comparing Inactivated and Live Attenuated Influenza Vaccines

    Directory of Open Access Journals (Sweden)

    Saranya Sridhar

    2015-04-01

    Full Text Available Influenza is a major respiratory pathogen causing annual outbreaks and occasional pandemics. Influenza vaccination is the major method of prophylaxis. Currently annual influenza vaccination is recommended for groups at high risk of complications from influenza infection such as pregnant women, young children, people with underlying disease and the elderly, along with occupational groups such a healthcare workers and farm workers. There are two main types of vaccines available: the parenteral inactivated influenza vaccine and the intranasal live attenuated influenza vaccine. The inactivated vaccines are licensed from 6 months of age and have been used for more than 50 years with a good safety profile. Inactivated vaccines are standardized according to the presence of the viral major surface glycoprotein hemagglutinin and protection is mediated by the induction of vaccine strain specific antibody responses. In contrast, the live attenuated vaccines are licensed in Europe for children from 2–17 years of age and provide a multifaceted immune response with local and systemic antibody and T cell responses but with no clear correlate of protection. Here we discuss the immunological immune responses elicited by the two vaccines and discuss future work to better define correlates of protection.

  3. Extended Storage of Pathogen-Reduced Platelet Concentrates (PRECON)

    Science.gov (United States)

    2017-12-01

    transfusion. Our project proposes to determine the efficacy of using a pathogen inactivation technique (Mirasol) coupled with a platelet additive solution (PAS...technology, platelet additive solution, platelet recovery and survival, platelet storage, platelet storage solution, platelets, thrombocytopenia, transfusion...Platelets Report to 2017 Military Health System Research Symposium ……………………………………………………………….. 29 Extended Storage of Pathogen-Reduced Platelet Concentrates

  4. Foodborne pathogens

    Directory of Open Access Journals (Sweden)

    Thomas Bintsis

    2017-06-01

    Full Text Available Foodborne pathogens are causing a great number of diseases with significant effects on human health and economy. The characteristics of the most common pathogenic bacteria (Bacillus cereus, Campylobacter jejuni, Clostridium botulinum, Clostridium perfringens, Cronobacter sakazakii, Esherichia coli, Listeria monocytogenes, Salmonella spp., Shigella spp., Staphylococccus aureus, Vibrio spp. and Yersinia enterocolitica, viruses (Hepatitis A and Noroviruses and parasites (Cyclospora cayetanensis, Toxoplasma gondii and Trichinella spiralis, together with some important outbreaks, are reviewed. Food safety management systems based on to classical hazard-based approach has been proved to be inefficient, and risk-based food safety approach is now suggested from leading researchers and organizations. In this context, a food safety management system should be designed in a way to estimate the risks to human health from food consumption and to identify, select and implement mitigation strategies in order to control and reduce these risks. In addition, the application of suitable food safety education programs for all involved people in the production and consumption of foods is suggested.

  5. Inhibition of Retinoblastoma Protein Inactivation

    Science.gov (United States)

    2017-11-01

    CONTRACT NUMBER Inhibition of Retinoblastoma Protein Inactivation 5b. GRANT NUMBER W81XWH-14-1-0329 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Seth M...confirmed 108 compounds as giving a dose-response curve with at least 30% inhibition at 10 µM. The flowchart of hit progression is shown on the...Cancer Research Program under Award No. W81XWH-14-1-0329 to S.M.R. Opinions, interpretations, conclusions, and recommendations are those of the author

  6. Radiobiological inactivation of Epstein-Barr virus

    International Nuclear Information System (INIS)

    Henderson, E.; Heston, L.; Grogan, E.; Miller, G.

    1978-01-01

    Lymphocyte transforming properties of B95-8 strain Epstein-Barr virus (EBV) are very sensitive to inactivation by either uv or x irradiation. No dose of irradiation increases the transforming capacity of EBV. The x-ray dose needed for inactivation of EBV transformation (dose that results in 37% survival, 60,000 rads) is similar to the dose required for inactivation of plaque formation by herpes simplex virus type 1 (Fischer strain). Although herpes simplex virus is more sensitive than EBV to uv irradiation, this difference is most likely due to differences in the kinetics or mechanisms of repair of uv damage to the two viruses. The results lead to the hypothesis that a large part, or perhaps all, of the EBV genome is in some way needed to initiate transformation. The abilities of EBV to stimulate host cell DNA synthesis, to induce nuclear antigen, and to immortalize are inactivated in parallel. All clones of marmoset cells transformed by irradiated virus produce extracellular transforming virus. These findings suggest that the abilities of the virus to transform and to replicate complete progeny are inactivated together. The amounts of uv and x irradiation that inactivate transformation by B95-8 virus are less than the dose needed to inactivate early antigen induction by the nontransforming P 3 HR-1 strain of EBV. Based on radiobiological inactivation, 10 to 50% of the genome is needed for early antigen induction

  7. Photodynamic Inactivation of Mammalian Viruses and Bacteriophages

    Directory of Open Access Journals (Sweden)

    Liliana Costa

    2012-06-01

    Full Text Available Photodynamic inactivation (PDI has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process.

  8. Inactivation of E.coli O157:H7 and Salmonella on fresh strawberries by antimicrobial washing and coating

    Science.gov (United States)

    Antimicrobial washing, antimicrobial coating, and a combination of both treatments were evaluated for their ability to inactivate artificially inoculated foodborne pathogens and native microflora on strawberries stored at 4 degrees C. Strawberries were inoculated with a six-strain composite of E. co...

  9. Inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree by high hydrostatic pressure with/without added ascorbic acid

    Science.gov (United States)

    The objective of this research was to evaluate and develop a method for inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree (CP) by high hydrostatic pressure (HHP). Cantaloupe being the most netted varieties of melons presents a greater risk of pathogen transmission. ...

  10. Peracetic Acid Treatment Generates Potent Inactivated Oral Vaccines from a Broad Range of Culturable Bacterial Species

    Science.gov (United States)

    Moor, Kathrin; Wotzka, Sandra Y.; Toska, Albulena; Diard, Médéric; Hapfelmeier, Siegfried; Slack, Emma

    2016-01-01

    Our mucosal surfaces are the main sites of non-vector-borne pathogen entry, as well as the main interface with our commensal microbiota. We are still only beginning to understand how mucosal adaptive immunity interacts with commensal and pathogenic microbes to influence factors such as infectivity, phenotypic diversity, and within-host evolution. This is in part due to difficulties in generating specific mucosal adaptive immune responses without disrupting the mucosal microbial ecosystem itself. Here, we present a very simple tool to generate inactivated mucosal vaccines from a broad range of culturable bacteria. Oral gavage of 1010 peracetic acid-inactivated bacteria induces high-titer-specific intestinal IgA in the absence of any measurable inflammation or species invasion. As a proof of principle, we demonstrate that this technique is sufficient to provide fully protective immunity in the murine model of invasive non-typhoidal Salmonellosis, even in the face of severe innate immune deficiency. PMID:26904024

  11. Fate and transport of pathogens in lakes and reservoirs.

    Science.gov (United States)

    Brookes, Justin D; Antenucci, Jason; Hipsey, Matthew; Burch, Michael D; Ashbolt, Nicholas J; Ferguson, Christobel

    2004-07-01

    Outbreaks of water-borne disease via public water supplies continue to be reported in developed countries even though there is increased awareness of, and treatment for, pathogen contamination. Pathogen episodes in lakes and reservoirs are often associated with rain events, and the riverine inflow is considered to be major source of pathogens. Consequently, the behaviour of these inflows is of particular importance in determining pathogen transport and distribution. Inflows are controlled by their density relative to that of the lake, such that warm inflows will flow over the surface of the lake as a buoyant surface flow and cold, dense inflows will sink beneath the lake water where they will flow along the bathymetry towards the deepest point. The fate of pathogens is determined by loss processes including settling and inactivation by temperature, UV and grazing. The general trend is for the insertion timescale to be shortest, followed by sedimentation losses and temperature inactivity. The fate of Cryptosporidium due to UV light inactivation can occur at opposite ends of the scale, depending on the location of the oocysts in the water column and the extinction coefficient for UV light. For this reason, the extinction coefficient for UV light appears to be a vitally important parameter for determining the risk of Cryptosporidium contamination. For risk assessment of pathogens in supply reservoirs, it is important to understand the role of hydrodynamics in determining the timescale of transport to the off-take relative to the timescale of inactivation. The characteristics of the riverine intrusion must also be considered when designing a sampling program for pathogens. A risk management framework is presented that accounts for pathogen fate and transport for reservoirs.

  12. Inactivation of Escherichia coli in soil by solarization

    International Nuclear Information System (INIS)

    Wu, S.; Nishihara, M.; Kawasaki, Y.; Yokoyama, A.; Matsuura, K.; Koga, T.; Ueno, D.; Inoue, K.; Someya, T.

    2009-01-01

    Contamination of agricultural soil by fecal pathogenic bacteria poses a potential risk of infection to humans. For the biosafety control of field soil, soil solarization in an upland field was examined to determine the efficiency of solarization on the inactivation of Escherichia coli inoculated into soil as a model microorganism for human pathogenic bacteria. Soil solarization, carried out by sprinkling water and covering the soil surface with thin plastic sheets, greatly increased the soil temperature. The daily average temperature of the solarized soil was 4–10°C higher than that of the non-solarized soil and fluctuated between 31 and 38°C. The daily highest temperature reached more than 40°C for 8 days in total in the solarized soil during the second and third weeks of the experiment. Escherichia coli in the solarized soil became undetectable (< 0.08 c.f.u. g −1 dry soil) within 4 weeks as a result, whereas E. coli survived for more than 6 weeks in the non-solarized soil. Soil solarization, however, had little influence on the total direct count and total viable count of bacteria in the soil. These results indicate that soil solarization would be useful for the biosafety control of soil contaminated by human pathogens via immature compost or animal feces. (author)

  13. Inactivation of DNA mismatch repair by variants of uncertain significance in the PMS2 gene.

    Science.gov (United States)

    Drost, Mark; Koppejan, Hester; de Wind, Niels

    2013-11-01

    Lynch syndrome (LS) is a common cancer predisposition caused by an inactivating mutation in one of four DNA mismatch repair (MMR) genes. Frequently a variant of uncertain significance (VUS), rather than an obviously pathogenic mutation, is identified in one of these genes. The inability to define pathogenicity of such variants precludes targeted healthcare. Here, we have modified a cell-free assay to test VUS in the MMR gene PMS2 for functional activity. We have analyzed nearly all VUS in PMS2 found thus far and describe loss of MMR activity for five, suggesting the applicability of the assay for diagnosis of LS. © 2013 WILEY PERIODICALS, INC.

  14. Skewed X-inactivation in cloned mice

    International Nuclear Information System (INIS)

    Senda, Sho; Wakayama, Teruhiko; Yamazaki, Yukiko; Ohgane, Jun; Hattori, Naka; Tanaka, Satoshi; Yanagimachi, Ryuzo; Shiota, Kunio

    2004-01-01

    In female mammals, dosage compensation for X-linked genes is accomplished by inactivation of one of two X chromosomes. The X-inactivation ratio (a percentage of the cells with inactivated maternal X chromosomes in the whole cells) is skewed as a consequence of various genetic mutations, and has been observed in a number of X-linked disorders. We previously reported that phenotypically normal full-term cloned mouse fetuses had loci with inappropriate DNA methylation. Thus, cloned mice are excellent models to study abnormal epigenetic events in mammalian development. In the present study, we analyzed X-inactivation ratios in adult female cloned mice (B6C3F1). Kidneys of eight naturally produced controls and 11 cloned mice were analyzed. Although variations in X-inactivation ratio among the mice were observed in both groups, the distributions were significantly different (Ansary-Bradley test, P < 0.01). In particular, 2 of 11 cloned mice showed skewed X-inactivation ratios (19.2% and 86.8%). Similarly, in intestine, 1 of 10 cloned mice had a skewed ratio (75.7%). Skewed X-inactivation was observed to various degrees in different tissues of different individuals, suggesting that skewed X-inactivation in cloned mice is the result of secondary cell selection in combination with stochastic distortion of primary choice. The present study is the first demonstration that skewed X-inactivation occurs in cloned animals. This finding is important for understanding both nuclear transfer technology and etiology of X-linked disorders

  15. Pathogen reduction of blood components.

    Science.gov (United States)

    Solheim, Bjarte G

    2008-08-01

    Thanks to many blood safety interventions introduced in developed countries the risk of transfusion transmitted infections has become exceedingly small in these countries. However, emerging pathogens still represent a serious challenge, as demonstrated by West Nile virus in the US and more recently by Chikungunya virus in the Indian Ocean. In addition bacterial contamination, particularly in platelets, and protozoa transmitted by blood components still represent sizeable risks in developed countries. In developing countries the risk of all transfusion transmitted infections is still high due to insufficient funding and organisation of the health service. Pathogen reduction of pooled plasma products has virtually eliminated the risk of transfusion transmitted infections, without compromising the quality of the products significantly. Pathogen reduction of blood components has been much more challenging. Solvent detergent treatment which has been so successfully applied for plasma products dissolves cell membranes, and can, therefore, only be applied for plasma and not for cellular blood components. Targeting of nucleic acids has been another method for pathogen inactivation of plasma and the only approach possible for cellular blood products. As documented in more than 15 year's track record, solvent detergent treatment of pooled plasma can yield high quality plasma. The increased risk for contamination by unknown viruses due to pooling is out weighed by elimination of TRALI, significant reduction in allergic reactions and standardisation of the product. Recently, a promising method for solvent detergent treatment of single donor plasma units has been published. Methylene blue light treatment of single donor plasma units has a similar long track record as pooled solvent detergent treated plasma; but the method is less well documented and affects coagulation factor activity more. Psoralen light treated plasma has only recently been introduced (CE marked in Europe

  16. Efficacy of Inactivation of Human Enteroviruses by Multiple ...

    Science.gov (United States)

    Ultraviolet (UV) light has been successfully used for treating a broad suite of pathogens without the concomitant formation of carcinogenic disinfection by-products (DBPs). However, conventional mercury UV lamps have some practical limitations in water treatment applications, such as the inefficiency of energy consumption and more importantly potential mercury contamination upon disposal of the lamps. The recent invention of a novel light-emitting-diodes (LED) device generating germicidal UV wavelengths could eliminate the aforementioned limitations. In this study, we investigated the efficacy of multiple-wavelength UV LEDs for inactivating USEPA contaminant candidate list (CCL) RNA enteroviruses. Of 12 enterovirus species, serotype representatives of the four human enteric species (enterovirus A-D) such as coxsackievirus A10 (CVA10), echovirus 30 (Echo30), poliovirus 1 (PV1), and enterovirus 70 (EV70) respectively were selected as testing RNA viruses. Bench-scale performance evaluation was conducted using a collimated beam (CB) apparatus with LEDs emitting at 260 nm, 280 nm, and the combination of 260|280 nm together, as well as a monochromatic low-pressure (LP) UV lamp at 254 nm for comparison. The CB tests were performed with mixed stocks of four viruses. Infectious virus concentrations were determined using an integrated cell culture reverse transcriptase quantitative PCR (ICC-RTqPCR). The 260 nm LED was most effective at inactivating all enteroviruses teste

  17. Doc toxin is a kinase that inactivates elongation factor Tu.

    Science.gov (United States)

    Cruz, Jonathan W; Rothenbacher, Francesca P; Maehigashi, Tatsuya; Lane, William S; Dunham, Christine M; Woychik, Nancy A

    2014-03-14

    The Doc toxin from bacteriophage P1 (of the phd-doc toxin-antitoxin system) has served as a model for the family of Doc toxins, many of which are harbored in the genomes of pathogens. We have shown previously that the mode of action of this toxin is distinct from the majority derived from toxin-antitoxin systems: it does not cleave RNA; in fact P1 Doc expression leads to mRNA stabilization. However, the molecular triggers that lead to translation arrest are not understood. The presence of a Fic domain, albeit slightly altered in length and at the catalytic site, provided a clue to the mechanism of P1 Doc action, as most proteins with this conserved domain inactivate GTPases through addition of an adenylyl group (also referred to as AMPylation). We demonstrated that P1 Doc added a single phosphate group to the essential translation elongation factor and GTPase, elongation factor (EF)-Tu. The phosphorylation site was at a highly conserved threonine, Thr-382, which was blocked when EF-Tu was treated with the antibiotic kirromycin. Therefore, we have established that Fic domain proteins can function as kinases. This distinct enzymatic activity exhibited by P1 Doc also solves the mystery of the degenerate Fic motif unique to the Doc family of toxins. Moreover, we have established that all characterized Fic domain proteins, even those that phosphorylate, target pivotal GTPases for inactivation through a post-translational modification at a single functionally critical acceptor site.

  18. Doc Toxin Is a Kinase That Inactivates Elongation Factor Tu*

    Science.gov (United States)

    Cruz, Jonathan W.; Rothenbacher, Francesca P.; Maehigashi, Tatsuya; Lane, William S.; Dunham, Christine M.; Woychik, Nancy A.

    2014-01-01

    The Doc toxin from bacteriophage P1 (of the phd-doc toxin-antitoxin system) has served as a model for the family of Doc toxins, many of which are harbored in the genomes of pathogens. We have shown previously that the mode of action of this toxin is distinct from the majority derived from toxin-antitoxin systems: it does not cleave RNA; in fact P1 Doc expression leads to mRNA stabilization. However, the molecular triggers that lead to translation arrest are not understood. The presence of a Fic domain, albeit slightly altered in length and at the catalytic site, provided a clue to the mechanism of P1 Doc action, as most proteins with this conserved domain inactivate GTPases through addition of an adenylyl group (also referred to as AMPylation). We demonstrated that P1 Doc added a single phosphate group to the essential translation elongation factor and GTPase, elongation factor (EF)-Tu. The phosphorylation site was at a highly conserved threonine, Thr-382, which was blocked when EF-Tu was treated with the antibiotic kirromycin. Therefore, we have established that Fic domain proteins can function as kinases. This distinct enzymatic activity exhibited by P1 Doc also solves the mystery of the degenerate Fic motif unique to the Doc family of toxins. Moreover, we have established that all characterized Fic domain proteins, even those that phosphorylate, target pivotal GTPases for inactivation through a post-translational modification at a single functionally critical acceptor site. PMID:24448800

  19. Mirasol PRT system inactivation efficacy evaluated in platelet concentrates by bacteria-contamination model

    Directory of Open Access Journals (Sweden)

    Jocić Miodrag

    2011-01-01

    Full Text Available Background/Aim. Bacterial contamination of blood components, primarily platelet concentrates (PCs, has been identified as one of the most frequent infectious complications in transfusion practice. PC units have a high risk for bacterial growth/multiplication due to their storage at ambient temperature (20 ± 2°C. Consequences of blood contamination could be effectively prevented or reduced by pathogen inactivation systems. The aim of this study was to determine the Mirasol pathogen reduction technology (PRT system efficacy in PCs using an artificial bacteria-contamination model. Methods. According to the ABO blood groups, PC units (n = 216 were pooled into 54 pools (PC-Ps. PC-Ps were divided into three equal groups, with 18 units in each, designed for an artificial bacteria-contamination. Briefly, PC-Ps were contaminated by Staphylococcus epidermidis, Staphylococcus aureus or Escherichia coli in concentrations 102 to 107 colony forming units (CFU per unit. Afterward, PC-Ps were underwent to inactivation by Mirasol PRT system, using UV (l = 265-370 nm activated riboflavin (RB. All PC-Ps were assayed by BacT/Alert Microbial Detection System for CFU quantification before and after the Mirasol treatment. Samples from non-inactivated PC-P units were tested after preparation and immediately following bacterial contamination. Samples from Mirasol treated units were quantified for CFUs one hour, 3 days and 5 days after inactivation. Results. A complete inactivation of all bacteria species was obtained at CFU concentrations of 102 and 103 per PC-P unit through storage/ investigation period. The most effective inactivation (105 CFU per PC-P unit was obtained in Escherichia coli setting. Contrary, inactivation of all the three tested bacteria species was unworkable in concentrations of ≥ 106 CFU per PC-P unit. Conclusion. Efficient inactivation of investigated bacteria types with a significant CFU depletion in PC-P units was obtained - 3 Log for all

  20. Inactivation of urease by catechol: Kinetics and structure.

    Science.gov (United States)

    Mazzei, Luca; Cianci, Michele; Musiani, Francesco; Lente, Gábor; Palombo, Marta; Ciurli, Stefano

    2017-01-01

    Urease is a Ni(II)-containing enzyme that catalyzes the hydrolysis of urea to yield ammonia and carbamate at a rate 10 15 times higher than the uncatalyzed reaction. Urease is a virulence factor of several human pathogens, in addition to decreasing the efficiency of soil organic nitrogen fertilization. Therefore, efficient urease inhibitors are actively sought. In this study, we describe a molecular characterization of the interaction between urease from Sporosarcina pasteurii (SPU) and Canavalia ensiformis (jack bean, JBU) with catechol, a model polyphenol. In particular, catechol irreversibly inactivates both SPU and JBU with a complex radical-based autocatalytic multistep mechanism. The crystal structure of the SPU-catechol complex, determined at 1.50Å resolution, reveals the structural details of the enzyme inhibition. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Emerging Pathogens Initiative (EPI)

    Data.gov (United States)

    Department of Veterans Affairs — The Emerging Pathogens Initiative (EPI) database contains emerging pathogens information from the local Veterans Affairs Medical Centers (VAMCs). The EPI software...

  2. Factors controlling pathogen destruction during anaerobic digestion of biowastes

    International Nuclear Information System (INIS)

    Smith, S.R.; Lang, N.L.; Cheung, K.H.M.; Spanoudaki, K.

    2005-01-01

    Anaerobic digestion is the principal method of stabilising biosolids from urban wastewater treatment in the UK, and it also has application for the treatment of other types of biowaste. Increasing awareness of the potential risks to human and animal health from environmental sources of pathogens has focused attention on the efficacy of waste treatment processes at destroying pathogenic microorganisms in biowastes recycled to agricultural land. The degree of disinfection achieved by a particular anaerobic digester is influenced by a variety of interacting operational variables and conditions, which can often deviate from the ideal. Experimental investigations demonstrate that Escherichia coli and Salmonella spp. are not damaged by mesophilic temperatures, whereas rapid inactivation occurs by thermophilic digestion. A hydraulic, biokinetic and thermodynamic model of pathogen inactivation during anaerobic digestion showed that a 2 log 10 reduction in E. coli (the minimum removal required for agricultural use of conventionally treated biosolids) is likely to challenge most conventional mesophilic digesters, unless strict maintenance and management practices are adopted to minimise dead zones and by-pass flow. Efficient mixing and organic matter stabilisation are the main factors controlling the rate of inactivation under mesophilic conditions and not a direct effect of temperature per se on pathogenic organisms

  3. Susceptibility of pathogenic and nonpathogenic Naegleria ssp

    International Nuclear Information System (INIS)

    Whiteman, L.Y.

    1988-01-01

    The susceptibility of four species of Naegleria amoebae to complement-mediated lysis was determined. The amoebicidal activity of normal human serum (NHS) and normal guinea pig serum (NGPS) for Naegleria amoebae was measured by an in vitro cytotoxicity assay. Release of radioactivity from amoebae labeled with 3 H-uridine and visual observation with a compound microscope were used as indices of lysis. Susceptibility or resistance to complement-mediated lysis in vitro correlated with the in vivo pathogenic potential. Nonpathogenic Naegleria amoebae were lysed at a faster rate and at higher cell concentrations than were pathogenic amoebae. Electrophoretic analysis of NHS incubated with pathogenic or nonpathogenic Naegleria spp. demonstrated that amoebae activate the complement cascade resulting in the production of C3 and C5 complement cleavage products. Treatment with papain or trypsin for 1 h, but not with sialidase, increase the susceptibility of highly pathogenic, mouse-passaged N. fowleri to lysis. Treatment with actinomycin D, cycloheximide or various protease inhibitors for 4 h did not increase susceptibility to lysis. Neither a repair process involving de novo protein synthesis nor a complement-inactivating protease appear to account for the increase resistance of N. fowleri amoebae to complement-mediated lysis. A binding study with 125 I radiolabeled C9 indicated that the terminal complement component does not remain stably bound to the membrane of pathogenic amoebae

  4. Regulatory Proteolysis in Arabidopsis-Pathogen Interactions.

    Science.gov (United States)

    Pogány, Miklós; Dankó, Tamás; Kámán-Tóth, Evelin; Schwarczinger, Ildikó; Bozsó, Zoltán

    2015-09-24

    Approximately two and a half percent of protein coding genes in Arabidopsis encode enzymes with known or putative proteolytic activity. Proteases possess not only common housekeeping functions by recycling nonfunctional proteins. By irreversibly cleaving other proteins, they regulate crucial developmental processes and control responses to environmental changes. Regulatory proteolysis is also indispensable in interactions between plants and their microbial pathogens. Proteolytic cleavage is simultaneously used both by plant cells, to recognize and inactivate invading pathogens, and by microbes, to overcome the immune system of the plant and successfully colonize host cells. In this review, we present available results on the group of proteases in the model plant Arabidopsis thaliana whose functions in microbial pathogenesis were confirmed. Pathogen-derived proteolytic factors are also discussed when they are involved in the cleavage of host metabolites. Considering the wealth of review papers available in the field of the ubiquitin-26S proteasome system results on the ubiquitin cascade are not presented. Arabidopsis and its pathogens are conferred with abundant sets of proteases. This review compiles a list of those that are apparently involved in an interaction between the plant and its pathogens, also presenting their molecular partners when available.

  5. Microbial Inactivation by Ultrasound Assisted Supercritical Fluids

    Science.gov (United States)

    Benedito, Jose; Ortuño, Carmen; Castillo-Zamudio, Rosa Isela; Mulet, Antonio

    A method combining supercritical carbon dioxide (SC-CO2) and high power ultrasound (HPU) has been developed and tested for microbial/enzyme inactivation purposes, at different process conditions for both liquid and solid matrices. In culture media, using only SC-CO2, the inactivation rate of E. coli and S. cerevisiae increased with pressure and temperature; and the total inactivation (7-8 log-cycles) was attained after 25 and 140 min of SC-CO2 (350 bar, 36 °C) treatment, respectively. Using SC-CO2+HPU, the time for the total inactivation of both microorganisms was reduced to only 1-2 min, at any condition selected. The SC-CO2+HPU inactivation of both microorganisms was slower in juices (avg. 4.9 min) than in culture media (avg. 1.5 min). In solid samples (chicken, turkey ham and dry-cured pork cured ham) treated with SC-CO2 and SC-CO2+HPU, the inactivation rate of E. coli increased with temperature. The application of HPU to the SC-CO2 treatments accelerated the inactivation rate of E. coli and that effect was more pronounced in treatments with isotonic solution surrounding the solid food samples. The application of HPU enhanced the SC-CO2 inactivation mechanisms of microorganisms, generating a vigorous agitation that facilitated the CO2 solubilization and the mass transfer process. The cavitation generated by HPU could damage the cell walls accelerating the extraction of vital constituents and the microbial death. Thus, using the combined technique, reasonable industrial processing times and mild process conditions could be used which could result into a cost reduction and lead to the minimization in the food nutritional and organoleptic changes.

  6. Plasma temperature during methylene blue/light treatment influences virus inactivation capacity and product quality.

    Science.gov (United States)

    Gravemann, U; Handke, W; Sumian, C; Alvarez, I; Reichenberg, S; Müller, T H; Seltsam, A

    2018-02-27

    Photodynamic treatment using methylene blue (MB) and visible light is in routine use for pathogen inactivation of human plasma in different countries. Ambient and product temperature conditions for human plasma during production may vary between production sites. The influence of different temperature conditions on virus inactivation capacity and plasma quality of the THERAFLEX MB-Plasma procedure was investigated in this study. Plasma units equilibrated to 5 ± 2°C, room temperature (22 ± 2°C) or 30 ± 2°C were treated with MB/light and comparatively assessed for the inactivation capacity for three different viruses, concentrations of MB and its photoproducts, activity of various plasma coagulation factors and clotting time. Reduced solubility of the MB pill was observed at 5 ± 2°C. Photocatalytic degradation of MB increased with increasing temperature, and the greatest formation of photoproducts (mainly azure B) occurred at 30 ± 2°C. Inactivation of suid herpesvirus, bovine viral diarrhoea virus and vesicular stomatitis virus was significantly lower at 5 ± 2°C than at higher temperatures. MB/light treatment affected clotting times and the activity of almost all investigated plasma proteins. Factor VIII (-17·7 ± 8·3%, 22 ± 2°C) and fibrinogen (-14·4 ± 16·4%, 22 ± 2°C) showed the highest decreases in activity. Increasing plasma temperatures resulted in greater changes in clotting time and higher losses of plasma coagulation factor activity. Temperature conditions for THERAFLEX MB-Plasma treatment must be carefully controlled to assure uniform quality of pathogen-reduced plasma in routine production. Inactivation of cooled plasma is not recommended. © 2018 International Society of Blood Transfusion.

  7. Comparative flight activities and pathogen load of two stocks of honey bees reared in gamma-irradiated combs

    Science.gov (United States)

    Gamma irradiation is known to inactivate various pathogens that negatively affect honey bee health. Bee pathogens such as Deformed wing virus (DWV) and Nosema spp. have deleterious impact on foraging activities and bee survival, and have been detected in combs. In this study, we assessed the effects...

  8. Cell inactivation by heavy charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Blakely, E A [Lawrence Berkeley Lab., CA (United States). Cell and Molecular Biology Div.

    1992-06-01

    The inactivation of cells resulting in lethal or aberrant effects by charged particles is of growing interest. Charged particles at extremely high LET are capable of completely eliminating cell-type and cell-line differences in repair capacity. It is still not clear however whether the repair systems are inactivated, or merely that heavy-ion lesions are less repairable. Studies correlating the particle inactivation dose of radioresistant cells with intact DNA analyzed with pulse field gel electrophoresis and other techniques may be useful, but more experiments are also needed to assess the fidelity of repair. For particle irradiations between 40-100 keV/{mu}m there is however evidence for particle-induced activation of specific genes in mammalian cells, and certain repair processes in bacteria. New data are available on the inactivation of developmental processes in several systems including seeds, and cells of the nematode C. elegans. Future experimental and theoretical modeling research emphasis should focus on exploring particle-induced inactivation of endpoints assessing functionality and not just lethality, and on analyzing molecular damage and genetic effects arising in damage but non-inactivated survivors. The discrete nature of selective types of particle damage as a function of radiation quality indicates the value of accelerated ions as probes of normal and aberrant biological processes. Information obtained from molecular analyses of damage and repair must however be integrated into the context of cellular and tissue functions of the organism. (orig.).

  9. Inactivation of Prions and Amyloid Seeds with Hypochlorous Acid.

    Directory of Open Access Journals (Sweden)

    Andrew G Hughson

    2016-09-01

    Full Text Available Hypochlorous acid (HOCl is produced naturally by neutrophils and other cells to kill conventional microbes in vivo. Synthetic preparations containing HOCl can also be effective as microbial disinfectants. Here we have tested whether HOCl can also inactivate prions and other self-propagating protein amyloid seeds. Prions are deadly pathogens that are notoriously difficult to inactivate, and standard microbial disinfection protocols are often inadequate. Recommended treatments for prion decontamination include strongly basic (pH ≥~12 sodium hypochlorite bleach, ≥1 N sodium hydroxide, and/or prolonged autoclaving. These treatments are damaging and/or unsuitable for many clinical, agricultural and environmental applications. We have tested the anti-prion activity of a weakly acidic aqueous formulation of HOCl (BrioHOCl that poses no apparent hazard to either users or many surfaces. For example, BrioHOCl can be applied directly to skin and mucous membranes and has been aerosolized to treat entire rooms without apparent deleterious effects. Here, we demonstrate that immersion in BrioHOCl can inactivate not only a range of target microbes, including spores of Bacillus subtilis, but also prions in tissue suspensions and on stainless steel. Real-time quaking-induced conversion (RT-QuIC assays showed that BrioHOCl treatments eliminated all detectable prion seeding activity of human Creutzfeldt-Jakob disease, bovine spongiform encephalopathy, cervine chronic wasting disease, sheep scrapie and hamster scrapie; these findings indicated reductions of ≥103- to 106-fold. Transgenic mouse bioassays showed that all detectable hamster-adapted scrapie infectivity in brain homogenates or on steel wires was eliminated, representing reductions of ≥~105.75-fold and >104-fold, respectively. Inactivation of RT-QuIC seeding activity correlated with free chlorine concentration and higher order aggregation or destruction of proteins generally, including prion

  10. Complement Evasion by Pathogenic Leptospira.

    Science.gov (United States)

    Fraga, Tatiana Rodrigues; Isaac, Lourdes; Barbosa, Angela Silva

    2016-01-01

    Leptospirosis is a neglected infectious disease caused by spirochetes from the genus Leptospira . Pathogenic microorganisms, notably those which reach the blood circulation such as Leptospira , have evolved multiple strategies to escape the host complement system, which is important for innate and acquired immunity. Leptospira avoid complement-mediated killing through: (i) recruitment of host complement regulators; (ii) acquisition of host proteases that cleave complement proteins on the bacterial surface; and, (iii) secretion of proteases that inactivate complement proteins in the Leptospira surroundings. The recruitment of host soluble complement regulatory proteins includes the acquisition of Factor H (FH) and FH-like-1 (alternative pathway), C4b-binding protein (C4BP) (classical and lectin pathways), and vitronectin (Vn) (terminal pathway). Once bound to the leptospiral surface, FH and C4BP retain cofactor activity of Factor I in the cleavage of C3b and C4b, respectively. Vn acquisition by leptospires may result in terminal pathway inhibition by blocking C9 polymerization. The second evasion mechanism lies in plasminogen (PLG) binding to the leptospiral surface. In the presence of host activators, PLG is converted to enzymatically active plasmin, which is able to degrade C3b, C4b, and C5 at the surface of the pathogen. A third strategy used by leptospires to escape from complement system is the active secretion of proteases. Pathogenic, but not saprophytic leptospires, are able to secrete metalloproteases that cleave C3 (central complement molecule), Factor B (alternative pathway), and C4 and C2 (classical and lectin pathways). The purpose of this review is to fully explore these complement evasion mechanisms, which act together to favor Leptospira survival and multiplication in the host.

  11. Review: Efficiency of physical and chemical treatments on the inactivation of dairy bacteriophages

    Directory of Open Access Journals (Sweden)

    Daniela Marta Guglielmotti

    2012-01-01

    Full Text Available Bacteriophages can cause great economic losses due to fermentation failure in dairy plants. Hence, physical and chemical treatments of raw material and/or equipment are mandatory to maintain phage levels as low as possible. Regarding thermal treatments used to kill pathogenic bacteria or achieve longer shelf-life of dairy products, neither low temperature long time (LTLT nor high temperature short time (HTST pasteurization were able to inactivate most lactic acid bacteria (LAB phages. Even though most phages did not survive 90ºC for 2 min, there were some that resisted 90ºC for more than 15 min (conditions suggested by the International Dairy Federation, IDF, for complete phage destruction. Among biocides tested, ethanol showed variable effectiveness in phage inactivation, since only phages infecting dairy cocci and Lactobacillus helveticus were reasonably inactivated by this alcohol, whereas isopropanol was in all cases highly ineffective. In turn, peracetic acid has consistently proved to be very fast and efficient to inactivate dairy phages, whereas efficiency of sodium hypochlorite was variable, even among different phages infecting the same LAB species. Both alkaline chloride foam and ethoxylated nonylphenol with phosphoric acid were remarkably efficient, trait probably related to their highly alkaline or acidic pH values in solution, respectively. Photocatalysis using UV light and TiO2 has been recently reported as a feasible option to industrially inactivate phages infecting diverse LAB species. Processes involving high pressure were barely used for phage inactivation, but until now most studied phages revealed high resistance to these treatments. To conclude, and given the great phage diversity found on dairies, it is always advisable to combine different anti-phage treatments (biocides, heat, high pressure, photocatalysis, rather than using them separately at extreme conditions.

  12. Pathogenic psychrotolerant sporeformers: an emerging challenge for low-temperature storage of minimally processed foods.

    Science.gov (United States)

    Markland, Sarah M; Farkas, Daniel F; Kniel, Kalmia E; Hoover, Dallas G

    2013-05-01

    Sporeforming bacteria are a significant problem in the food industry as they are ubiquitous in nature and capable of resisting inactivation by heat and chemical treatments designed to inactivate them. Beyond spoilage issues, psychrotolerant sporeformers are becoming increasingly recognized as a potential hazard given the ever-expanding demand for refrigerated processed foods with extended shelf-life. In these products, the sporeforming pathogens of concern are Bacillus cereus, Bacillus weihenstephanensis, and Clostridium botulinum type E. This review article examines the foods, conditions, and organisms responsible for the food safety issue caused by the germination and outgrowth of psychrotolerant sporeforming pathogens in minimally processed refrigerated foods.

  13. Pathogen reduction of whole blood: utility and feasibility.

    Science.gov (United States)

    Allain, J-P; Goodrich, R

    2017-10-01

    To collect information on pathogen reduction applied to whole blood. Pathogen reduction (PR) of blood components has been developed over the past two decades, and pathogen-reduced fresh-frozen plasma and platelet concentrates are currently in clinical use. High cost and incomplete coverage of components make PR out of reach for low- and middle-income countries (LMIC). However, should PR become applicable to whole blood (WB), the main product transfused in sub-Saharan Africa, and be compatible with the preparation of clinically suitable components, cost would be minimised, and a range of safety measures in place at high cost in developed areas would become redundant. All articles called with "pathogen reduction", "pathogen inactivation" and "whole blood" were retrieved from Medline. References in articles were utilised. One such PR technology (PRT) applied to WB has been developed and has shown efficacious against viruses, bacteria and parasites in vitro; and has been able to inactivate nucleated blood cells whilst retaining the ability to prepare components with acceptable characteristics. The efficacy of this WB PRT has been demonstrated in vivo using the inactivation of Plasmodium falciparum as a model and showing a high degree of correlation between in vitro and in vivo data. Obtaining further evidence of efficacy on other suitable targets is warranted. Shortening of the process, which is currently around 50 min, or increasing the number of units simultaneously processed would be necessary to make PRT WB conducive to LMIC blood services' needs. Even if not 100% effective against agents that are present in high pathogen load titres, WB PRT could massively impact blood safety in LMIC by providing safer products at an affordable cost. © 2017 British Blood Transfusion Society.

  14. White spot syndrome virus inactivation study by using gamma irradiation

    Science.gov (United States)

    Heidareh, Marzieh; Sedeh, Farahnaz Motamedi; Soltani, Mehdi; Rajabifar, Saeed; Afsharnasab, Mohammad; Dashtiannasab, Aghil

    2014-09-01

    The present study was conducted to investigate the effect of gamma irradiation on white spot syndrome virus (WSSV). White spot syndrome virus is a pathogen of major economic importance in cultured penaeid shrimp industries. White spot disease can cause mortalities reaching 100% within 3-10 days of gross signs appearing. During the period of culture, immunostimulant agents and vaccines may provide potential methods to protect shrimps from opportunistic and pathogenic microrganisms. In this study, firstly, WSSV was isolated from infected shrimp and then multiplied in crayfish. WSSV was purified from the infected crayfish haemolymph by sucrose gradient and confirmed by transmission electron microscopy. In vivo virus titration was performed in shrimp, Penaeus semisulcatus. The LD50 of live virus stock was calculated 10 5.4/mL. Shrimp post-larvae (1-2 g) were treated with gamma-irradiated (different doses) WSSV (100 to 10-4 dilutions) for a period of 10 days. The dose/survival curve for irradiated and un-irradiated WSSV was drawn; the optimum dose range for inactivation of WSSV and unaltered antigenicity was obtained 14-15 kGy. This preliminary information suggests that shrimp appear to benefit from treatment with gammairradiated WSSV especially at 14-15 KGy.

  15. Advances in antimicrobial photodynamic inactivation at the nanoscale

    Science.gov (United States)

    Kashef, Nasim; Huang, Ying-Ying; Hamblin, Michael R.

    2017-08-01

    The alarming worldwide increase in antibiotic resistance amongst microbial pathogens necessitates a search for new antimicrobial techniques, which will not be affected by, or indeed cause resistance themselves. Light-mediated photoinactivation is one such technique that takes advantage of the whole spectrum of light to destroy a broad spectrum of pathogens. Many of these photoinactivation techniques rely on the participation of a diverse range of nanoparticles and nanostructures that have dimensions very similar to the wavelength of light. Photodynamic inactivation relies on the photochemical production of singlet oxygen from photosensitizing dyes (type II pathway) that can benefit remarkably from formulation in nanoparticle-based drug delivery vehicles. Fullerenes are a closed-cage carbon allotrope nanoparticle with a high absorption coefficient and triplet yield. Their photochemistry is highly dependent on microenvironment, and can be type II in organic solvents and type I (hydroxyl radicals) in a biological milieu. Titanium dioxide nanoparticles act as a large band-gap semiconductor that can carry out photo-induced electron transfer under ultraviolet A light and can also produce reactive oxygen species that kill microbial cells. We discuss some recent studies in which quite remarkable potentiation of microbial killing (up to six logs) can be obtained by the addition of simple inorganic salts such as the non-toxic sodium/potassium iodide, bromide, nitrite, and even the toxic sodium azide. Interesting mechanistic insights were obtained to explain this increased killing.

  16. Effective Thermal Inactivation of the Spores of Bacillus cereus Biofilms Using Microwave.

    Science.gov (United States)

    Park, Hyong Seok; Yang, Jungwoo; Choi, Hee Jung; Kim, Kyoung Heon

    2017-07-28

    Microwave sterilization was performed to inactivate the spores of biofilms of Bacillus cereus involved in foodborne illness. The sterilization conditions, such as the amount of water and the operating temperature and treatment time, were optimized using statistical analysis based on 15 runs of experimental results designed by the Box-Behnken method. Statistical analysis showed that the optimal conditions for the inactivation of B. cereus biofilms were 14 ml of water, 108°C of temperature, and 15 min of treatment time. Interestingly, response surface plots showed that the amount of water is the most important factor for microwave sterilization under the present conditions. Complete inactivation by microwaves was achieved in 5 min, and the inactivation efficiency by microwave was obviously higher than that by conventional steam autoclave. Finally, confocal laser scanning microscopy images showed that the principal effect of microwave treatment was cell membrane disruption. Thus, this study can contribute to the development of a process to control food-associated pathogens.

  17. Inactivation of enteroviruses in sewage with ozone

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, O.E.; Bogdanov, M.V.; Kazantseva, V.A.; Gabrilevskaia, L.N.; Kodkind, G.K.H.

    The study of ozone inactivation of enteroviruses in sewage showed the presence in sewage of suspensions of organic origin and bacterial flora to influence the rate of inactivation. The inactivation rate of poliomyelitis virus in sewage free from organic suspension and bacterial flora was significantly higher than that in sewage containing such suspension and bacterial flora. The inactivation rate of enteroviruses was found not to depend upon the protein and salt composition and pH of sewage or strain appurtenance of viruses. The inactivation rate of enteroviruses directly depended upon the dose of ozone and time of contact with it. Differences in the resistance of different types of poliomyelitis virus, ECHO and Coxsackie viruses to the effect of ozone are likely exist. These differences are manifested within the range of relatively small doses of ozone. E. coli is more resistant to ozone than entero-viruses. The results of laboratory studies were used to choose the regimen of sanitation of urban sewage to be used in technological cycles of industrial enterprises.

  18. Inactivation of Mycobacterium avium with free chlorine.

    Science.gov (United States)

    Luh, Jeanne; Mariñas, Benito J

    2007-07-15

    The inactivation kinetics of Mycobacterium avium with free chlorine was characterized by two stages: an initial phase at a relatively fast rate followed by a slower second stage of pseudo first-order kinetics. The inactivation rate of each stage was approximately the same for all experiments performed at a certain condition of pH and temperature; however, variability was observed for the disinfectant exposure at which the transition between the two stages occurred. This variability was not a function of the initial disinfectant concentration, the initial bacterial density, or the bacterial stock. However, the transition to the second stage varied more significantly at high temperatures (30 degrees C), while lower variability was observed at lower temperatures (5 and 20 degrees C). Experiments conducted at pH values in the range of 6-9 revealed that the inactivation of M. avium was primarily due to hypochlorous acid, with little contribution from hypochlorite ion within this pH range. The inactivation kinetics was represented with a two-population model. The activation energies for the resulting pseudo first-order rate constants for the populations with fast and slow kinetics were 100.3 and 96.5 kJ/mol, respectively. The magnitude of these values suggested that for waters of relatively high pH and low temperatures, little inactivation of M. avium would be achieved within treatment plants, providing a seeding source for distribution systems.

  19. Pathogenic adaptations to host-derived antibacterial copper

    Science.gov (United States)

    Chaturvedi, Kaveri S.; Henderson, Jeffrey P.

    2014-01-01

    Recent findings suggest that both host and pathogen manipulate copper content in infected host niches during infections. In this review, we summarize recent developments that implicate copper resistance as an important determinant of bacterial fitness at the host-pathogen interface. An essential mammalian nutrient, copper cycles between copper (I) (Cu+) in its reduced form and copper (II) (Cu2+) in its oxidized form under physiologic conditions. Cu+ is significantly more bactericidal than Cu2+ due to its ability to freely penetrate bacterial membranes and inactivate intracellular iron-sulfur clusters. Copper ions can also catalyze reactive oxygen species (ROS) generation, which may further contribute to their toxicity. Transporters, chaperones, redox proteins, receptors and transcription factors and even siderophores affect copper accumulation and distribution in both pathogenic microbes and their human hosts. This review will briefly cover evidence for copper as a mammalian antibacterial effector, the possible reasons for this toxicity, and pathogenic resistance mechanisms directed against it. PMID:24551598

  20. Microbial inactivation and cytotoxicity evaluation of UV irradiated coconut water in a novel continuous flow spiral reactor.

    Science.gov (United States)

    Bhullar, Manreet Singh; Patras, Ankit; Kilanzo-Nthenge, Agnes; Pokharel, Bharat; Yannam, Sudheer Kumar; Rakariyatham, Kanyasiri; Pan, Che; Xiao, Hang; Sasges, Michael

    2018-01-01

    A continuous-flow UV reactor operating at 254nm wave-length was used to investigate inactivation of microorganisms including bacteriophage in coconut water, a highly opaque liquid food. UV-C inactivation kinetics of two surrogate viruses (MS2, T1UV) and three bacteria (E. coli ATCC 25922, Salmonella Typhimurium ATCC 13311, Listeria monocytogenes ATCC 19115) in buffer and coconut water were investigated (D 10 values ranging from 2.82 to 4.54mJ·cm -2 ). A series of known UV-C doses were delivered to the samples. Inactivation levels of all organisms were linearly proportional to UV-C dose (r 2 >0.97). At the highest dose of 30mJ·cm -2 , the three pathogenic organisms were inactivated by >5 log 10 (pUV-C irradiation effectively inactivated bacteriophage and pathogenic microbes in coconut water. The inactivation kinetics of microorganisms were best described by log linear model with a low root mean square error (RMSE) and high coefficient of determination (r 2 >0.97). Models for predicting log reduction as a function of UV-C irradiation dose were found to be significant (pUV-C treatment did not generate cytotoxic compounds in the coconut water. This study clearly demonstrated that high levels of inactivation of pathogens can be achieved in coconut water, and suggested potential method for UV-C treatment of other liquid foods. This research paper provides scientific evidence of the potential benefits of UV-C irradiation in inactivating bacterial and viral surrogates at commercially relevant doses of 0-120mJ·cm -2 . The irradiated coconut water showed no cytotoxic effects on normal intestinal and healthy mice liver cells. UV-C irradiation is an attractive food preservation technology and offers opportunities for horticultural and food processing industries to meet the growing demand from consumers for healthier and safe food products. This study would provide technical support for commercialization of UV-C treatment of beverages. Copyright © 2017 Elsevier Ltd. All

  1. The inactivation of hepatitis A virus and other model viruses by UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Battigelli, D A; Sobsey, M D; Lobe, D C [North Carolina Univ., Chapel Hill, NC (United States). Dept. of Environmental Sciences

    1993-01-01

    Ultraviolet light is an attractive alternative to chemical disinfection of water, but little is known about its ability to inactivate important waterborne pathogens such as hepatitis A virus. Therefore, the sensitivity of HAV strain HM-175, coxsackievirus type B-5, rotavirus strain SA-11, and bacteriophages MS2 and [phi]X174 to ultraviolet radiation of 254 nm wavelength in phosphate buffered water was determined. Purified stocks of the viruses were combined and exposed to collimated UV radiation in a stirred reactor for a total dose of up to 40 mW sec/cm[sup 2]. Virus survival kinetics were determined from samples removed at dose intervals. The results of these experiments indicate that UV radiation can effectively inactivate viruses of public health concern in drinking water. (author).

  2. Study of sequential disinfection for the inactivation of protozoa and indicator microorganisms in wastewater

    Directory of Open Access Journals (Sweden)

    Raphael Corrêa Medeiros

    2015-05-01

    Full Text Available Sewage disinfection has the primary objective of inactivating pathogenic organisms to prevent the dissemination of waterborne diseases. This study analyzed individual disinfection, with chlorine and ultraviolet radiation, and sequential disinfection (chlorine-UV radiation. The tests were conducted with anaerobic effluent in batch, in laboratory scale, with two dosages of chlorine (10 and 20 mg L-1 and UV (2.5 and 6.1 Wh m-3. In addition, to guarantee the presence of cysts in the tests, 104 cysts per liter of Giardia spp. were inoculated. The resistance order was as follows: E. coli = Total Coliforms < Clostridium perfringens < Giardia spp.. Furthermore, synergistic effects reached 0.06 to 1.42 log of inactivation in sequential disinfection for both the most resistant microorganisms.

  3. The inactivation of hepatitis A virus and other model viruses by UV irradiation

    International Nuclear Information System (INIS)

    Battigelli, D.A.; Sobsey, M.D.; Lobe, D.C.

    1993-01-01

    Ultraviolet light is an attractive alternative to chemical disinfection of water, but little is known about its ability to inactivate important waterborne pathogens such as hepatitis A virus. Therefore, the sensitivity of HAV strain HM-175, coxsackievirus type B-5, rotavirus strain SA-11, and bacteriophages MS2 and φX174 to ultraviolet radiation of 254 nm wavelength in phosphate buffered water was determined. Purified stocks of the viruses were combined and exposed to collimated UV radiation in a stirred reactor for a total dose of up to 40 mW sec/cm 2 . Virus survival kinetics were determined from samples removed at dose intervals. The results of these experiments indicate that UV radiation can effectively inactivate viruses of public health concern in drinking water. (author)

  4. AMPK in Pathogens

    OpenAIRE

    Mesquita, Inês Morais; Moreira, Diana; Marques, Belém Sampaio; Laforge, Mireille; Cordeiro-da-Silva, Anabela; Ludovico, Paula; Estaquier, Jérôme; Silvestre, Ricardo Jorge Leal

    2016-01-01

    During host–pathogen interactions, a complex web of events is crucial for the outcome of infection. Pathogen recognition triggers powerful cellular signaling events that is translated into the induction and maintenance of innate and adaptive host immunity against infection. In opposition, pathogens employ active mechanisms to manipulate host cell regulatory pathways toward their proliferation and survival. Among these, subversion of host cell energy metabolism by pathogens is currently recogn...

  5. Porinas as an adyuvant of inactivated Newcastle vaccine in broilers

    Directory of Open Access Journals (Sweden)

    Francisco Bustos M.

    2005-05-01

    Full Text Available Three groups of 25 broilers were vaccinated on two opportunities by aerosol using inactivated NC (Newcastle virus and different helper concentrations of porinas (20 ìg, 50 ìg, 125 ìg. A fourth group was injected with live B1 virus (12 and 28 days of age nasally. The NC inactivated virus (La Sota strain was concentrated 10 times with PEG with a final titer of 1:2.056. Twenty serums for each group were taken in order to evaluate NC antibodies using the HI and double immuno-difusion tests for IgA detection at 1, 12, 28 and 42 days of age. During the study the chickens were on a restricted diet in order to control ascites (2.640 mosl. On day 42, two broilers of the fourth group (live virus presented ascites and 1 broiler of group 1 presented lung edema (20 ìg. The geometric mean for NC antibodies titers at 42 days of age was 2 in the groups 1,2,3 and 5.7 in the group 4 (Log 2. For IgA, 180 mg/dl, 135 mg/dl, 120 mg/dl and 176 mg/dl respectively. Three broilers of each group were challenged with a pathogenic strain of NC, at 42 day of age, without signs of disease after 72 hours when the positive control group was dead. Gross and microscopic lesions were not detected in the bursa of Fabricius or thymo. [thymo sounds like short hand for something that should be properly named.] Very good animal weight, conversion and efficiency results were observed in all the groups. New studies using a fixed dose of porinas, larger numbers of broilers and the establishment of protective levels of IgA against NC challenge are recommended.

  6. High pressure inactivation of human norovirus virus-like particles: evidence that the capsid of human norovirus is highly pressure resistant

    Science.gov (United States)

    Human norovirus (NoV) is the leading cause of non-bacterial acute gastroenteritis epidemics worldwide. High pressure processing (HPP) has been considered a promising non-thermal processing technology to inactivate food- and water-borne viral pathogens. Due to the lack of an effective cell culture fo...

  7. High Pressure Inactivation of HAV within Mussels

    Science.gov (United States)

    The potential of hepatitis A virus (HAV) to be inactivated within Mediterranean mussels (Mytilus galloprovincialis) and blue mussels (Mytilus edulis) by high pressure processing was evaluated. HAV was bioaccumulated within mussels to approximately 6-log10 PFU by exposure of mussels to HAV-contamina...

  8. Inactivation of prion infectivity by ionizing rays

    Energy Technology Data Exchange (ETDEWEB)

    Gominet, M. [Ionisos, ZI les Chatinieres, F01120 Dagneux (France); Vadrot, C.; Austruy, G. [Paris V University, Central Pharmacy of Hospitals, 4 avenue de l' Observatoire, F-75006, Paris (France); Darbord, J.C. [Paris V University, Central Pharmacy of Hospitals, 4 avenue de l' Observatoire, F-75006, Paris (France)], E-mail: darbord@pharmacie.univ-paris5.fr

    2007-11-15

    Inactivation of prion deposits on medical devices or prion contamination in pharmaceutical raw materials is considered as impossible by using gamma irradiation. Early, the guideline WHO/CDS/CSR/APH/2000 has described irradiation as an ineffective process. But, in 2003, S. Miekka et al. noted radiation inactivation of prions in a particular application to purify human albumin, shown by the physical denaturation of the infectious protein (PrP). The aim of our study was to determine the inactivation of prions with a scrapie model (strain C506M3) by irradiating standardised preparations. Results: Gamma irradiation was partially effective, showing a 4-5 log reduction on exposure to 50 kGy. A characteristic effect-dose curve was not observed (25, 50 and 100 kGy), only an increase in the incubation period of the murine disease (229 days with 25 kGy to 290 days with 100 kGy) compared with 170 days without irradiation. Since the inactivation was not a total one, the observed effect is significant. It is proposed that further work be undertaken with the model to investigate the application of gamma radiation known levels of prion contamination.

  9. Inactivation of prion infectivity by ionizing rays

    International Nuclear Information System (INIS)

    Gominet, M.; Vadrot, C.; Austruy, G.; Darbord, J.C.

    2007-01-01

    Inactivation of prion deposits on medical devices or prion contamination in pharmaceutical raw materials is considered as impossible by using gamma irradiation. Early, the guideline WHO/CDS/CSR/APH/2000 has described irradiation as an ineffective process. But, in 2003, S. Miekka et al. noted radiation inactivation of prions in a particular application to purify human albumin, shown by the physical denaturation of the infectious protein (PrP). The aim of our study was to determine the inactivation of prions with a scrapie model (strain C506M3) by irradiating standardised preparations. Results: Gamma irradiation was partially effective, showing a 4-5 log reduction on exposure to 50 kGy. A characteristic effect-dose curve was not observed (25, 50 and 100 kGy), only an increase in the incubation period of the murine disease (229 days with 25 kGy to 290 days with 100 kGy) compared with 170 days without irradiation. Since the inactivation was not a total one, the observed effect is significant. It is proposed that further work be undertaken with the model to investigate the application of gamma radiation known levels of prion contamination

  10. Pulsed electric field inactivation in a microreactor

    NARCIS (Netherlands)

    Fox, M.B.

    2006-01-01

    Pulsed electric fields (PEF) is a novel, non-thermal pasteurization method which uses short, high electric field pulses to inactivate microorganisms. The advantage of a pasteurization method like PEF compared to regular heat pasteurization is that the taste, flavour, texture and nutritional value

  11. Epigenetic inactivation of CHFR in human tumors.

    Science.gov (United States)

    Toyota, Minoru; Sasaki, Yasushi; Satoh, Ayumi; Ogi, Kazuhiro; Kikuchi, Takefumi; Suzuki, Hiromu; Mita, Hiroaki; Tanaka, Nobuyuki; Itoh, Fumio; Issa, Jean-Pierre J; Jair, Kam-Wing; Schuebel, Kornel E; Imai, Kohzoh; Tokino, Takashi

    2003-06-24

    Cell-cycle checkpoints controlling the orderly progression through mitosis are frequently disrupted in human cancers. One such checkpoint, entry into metaphase, is regulated by the CHFR gene encoding a protein possessing forkhead-associated and RING finger domains as well as ubiquitin-ligase activity. Although defects in this checkpoint have been described, the molecular basis and prevalence of CHFR inactivation in human tumors are still not fully understood. To address this question, we analyzed the pattern of CHFR expression in a number of human cancer cell lines and primary tumors. We found CpG methylation-dependent silencing of CHFR expression in 45% of cancer cell lines, 40% of primary colorectal cancers, 53% of colorectal adenomas, and 30% of primary head and neck cancers. Expression of CHFR was precisely correlated with both CpG methylation and deacetylation of histones H3 and H4 in the CpG-rich regulatory region. Moreover, CpG methylation and thus silencing of CHFR depended on the activities of two DNA methyltransferases, DNMT1 and DNMT3b, as their genetic inactivation restored CHFR expression. Finally, cells with CHFR methylation had an intrinsically high mitotic index when treated with microtubule inhibitor. This means that cells in which CHFR was epigenetically inactivated constitute loss-of-function alleles for mitotic checkpoint control. Taken together, these findings shed light on a pathway by which mitotic checkpoint is bypassed in cancer cells and suggest that inactivation of checkpoint genes is much more widespread than previously suspected.

  12. Genomic screening for blood-borne viruses in transfusion settings.

    Science.gov (United States)

    Allain, J P

    2000-02-01

    The residual risk of post-transfusion human immunodeficiency virus (HIV) infection is low but slightly higher for hepatitis B virus (HBV) and hepatitis C virus (HCV), the main reason being viraemia during the window period preceding antibody or antigen detection by enzyme immunoassays. Immunosilent-infected individuals and carriers of distant viral variants also play an unquantifiable role. Multiple techniques, e.g. reverse transcription-polymerase chain reaction (RT-PCR), PCR, ligase-chain reaction, nucleic acid sequence-based amplification (NASBA) and transcription-mediated amplification (TMA) have been developed to amplify and detect viral genomes as single or multiplex assays. Equipment providing various degrees of automation has been adapted to these techniques. Applying nucleic acid amplification techniques (NAT) to blood screening, two main approaches have been advocated: plasma pool and single-donation testing. Pool testing presents the advantage of lower cost and readily available equipment although it is prone to false negative and positive reactions. The time required to identify infected donations is incompatible with blood component release, and may lead to product waste. Single-unit testing, although appealing, is not yet fully automated and potentially very costly unless a systematic multiplex approach is taken. Although technically feasible, NAT applied to the blood supply needs to be clinically evaluated and its cost efficiency assessed in the general public health context. However, pool NAT is currently implemented in continental Europe and the USA.

  13. Inactivation of dengue, chikungunya, and Ross River viruses in platelet concentrates after treatment with ultraviolet C light.

    Science.gov (United States)

    Faddy, Helen M; Fryk, Jesse J; Prow, Natalie A; Watterson, Daniel; Young, Paul R; Hall, Roy A; Tolksdorf, Frank; Sumian, Chryslain; Gravemann, Ute; Seltsam, Axel; Marks, Denese C

    2016-06-01

    Arboviruses, including dengue (DENV 1-4), chikungunya (CHIKV), and Ross River (RRV), are emerging viruses that are a risk for transfusion safety globally. An approach for managing this risk is pathogen inactivation, such as the THERAFLEX UV-Platelets system. We investigated the ability of this system to inactivate the above mentioned arboviruses. DENV 1-4, CHIKV, or RRV were spiked into buffy coat (BC)-derived platelet (PLT) concentrates in additive solution and treated with the THERAFLEX UV-Platelets system at the following doses: 0.05, 0.1, 0.15, and 0.2 J/cm(2) (standard dose). Pre- and posttreatment samples were taken for each dose, and the level of viral infectivity was determined. At the standard ultraviolet C (UVC) dose (0.2 J/cm(2) ), viral inactivation of at least 4.43, 6.34, and 5.13 log or more, was observed for DENV 1-4, CHIKV, and RRV, respectively. A dose dependency in viral inactivation was observed with increasing UVC doses. Our study has shown that DENV, CHIKV, and RRV, spiked into BC-derived PLT concentrates, were inactivated by the THERAFLEX UV-Platelets system to the limit of detection of our assay, suggesting that this system could contribute to the safety of PLT concentrates with respect to these emerging arboviruses. © 2016 AABB.

  14. Monitoring ultraviolet (UV) radiation inactivation of Cronobacter sakazakii in dry infant formula using Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Liu, Qian; Lu, Xiaonan; Swanson, Barry G; Rasco, Barbara A; Kang, Dong-Hyun

    2012-01-01

    Cronobacter sakazakii is an opportunistic pathogen associated with dry infant formula presenting a high risk to low birth weight neonates. The inactivation of C. sakazakii in dry infant formula by ultraviolet (UV) radiation alone and combined with hot water treatment at temperatures of 55, 60, and 65 °C were applied in this study. UV radiation with doses in a range from 12.1 ± 0.30 kJ/m² to 72.8 ± 1.83 kJ/m² at room temperature demonstrated significant inactivation of C. sakazakii in dry infant formula (P radiation combining 60 °C hot water treatment increased inactivation of C. sakazakii cells significantly (P radiation on C. sakazakii inactivation kinetics (D value) were not observed in infant formula reconstituted in 55 and 65 °C water (P > 0.05). The inactivation mechanism was investigated using vibrational spectroscopy. Infrared spectroscopy detected significant stretching mode changes of macromolecules on the basis of spectral features, such as DNA, proteins, and lipids. Minor changes on cell membrane composition of C. sakazakii under UV radiation could be accurately and correctly monitored by infrared spectroscopy coupled with 2nd derivative transformation and principal component analysis. © 2011 Institute of Food Technologists®

  15. Electron beam inactivation of Tulane virus on fresh produce, and mechanism of inactivation of human norovirus surrogates by electron beam irradiation.

    Science.gov (United States)

    Predmore, Ashley; Sanglay, Gabriel C; DiCaprio, Erin; Li, Jianrong; Uribe, R M; Lee, Ken

    2015-04-02

    Ionizing radiation, whether by electron beams or gamma rays, is a non-thermal processing technique used to improve the microbial safety and shelf-life of many different food products. This technology is highly effective against bacterial pathogens, but data on its effect against foodborne viruses is limited. A mechanism of viral inactivation has been proposed with gamma irradiation, but no published study discloses a mechanism for electron beam (e-beam). This study had three distinct goals: 1) evaluate the sensitivity of a human norovirus surrogate, Tulane virus (TV), to e-beam irradiation in foods, 2) compare the difference in sensitivity of TV and murine norovirus (MNV-1) to e-beam irradiation, and 3) determine the mechanism of inactivation of these two viruses by e-beam irradiation. TV was reduced from 7 log10 units to undetectable levels at target doses of 16 kGy or higher in two food matrices (strawberries and lettuce). MNV-1 was more resistant to e-beam treatment than TV. At target doses of 4 kGy, e-beam provided a 1.6 and 1.2 log reduction of MNV-1 in phosphate buffered saline (PBS) and Dulbecco's Modified Eagle Medium (DMEM), compared to a 1.5 and 1.8 log reduction of TV in PBS and Opti-MEM, respectively. Transmission electron microscopy revealed that increased e-beam doses negatively affected the structure of both viruses. Analysis of viral proteins by SDS-PAGE found that irradiation also degraded viral proteins. Using RT-PCR, irradiation was shown to degrade viral genomic RNA. This suggests that the mechanism of inactivation of e-beam was likely the same as gamma irradiation as the damage to viral constituents led to inactivation. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Silent spread of highly pathogenic Avian Influenza H5N1 virus amongst vaccinated commercial layers

    NARCIS (Netherlands)

    Poetri, O.N.; Boven, M.; Claassen, I.J.T.M.; Koch, G.; Wibawan, I.W.; Stegeman, A.; Broek, van den J.; Bouma, A.

    2014-01-01

    The aim of this study was to determine whether a single vaccination of commercial layer type chickens with an inactivated vaccine containing highly pathogenic avian influenza virus strain H5N1 A/chicken/Legok/2003, carried out on the farm, was sufficient to protect against infection with the

  17. Function of VtPGIP in pathogenic fungus resistance of Vitis thunbergii

    African Journals Online (AJOL)

    In plants, polygalacturonase inhibitor proteins (PGIPs) are very important to inactivate polygalacturonases secreted by pathogens. Vitis thunbergii Sieb. et Zucc. polygalacturonase inhibitor proteins (VtPGIP) was first isolated from the wild grape Vitis thunbergii Sieb. et Zucc., which exhibits high resistance to disease. VtPGIP ...

  18. Cortical inactivation by cooling in small animals

    Directory of Open Access Journals (Sweden)

    Ben eCoomber

    2011-06-01

    Full Text Available Reversible inactivation of the cortex by surface cooling is a powerful method for studying the function of a particular area. Implanted cooling cryoloops have been used to study the role of individual cortical areas in auditory processing of awake-behaving cats. Cryoloops have also been used in rodents for reversible inactivation of the cortex, but recently there has been a concern that the cryoloop may also cool non-cortical structures either directly or via the perfusion of blood, cooled as it passed close to the cooling loop. In this study we have confirmed that the loop can inactivate most of the auditory cortex without causing a significant reduction in temperature of the auditory thalamus or other sub-cortical structures. We placed a cryoloop on the surface of the guinea pig cortex, cooled it to 2°C and measured thermal gradients across the neocortical surface. We found that the temperature dropped to 20-24°C among cells within a radius of about 2.5mm away from the loop. This temperature drop was sufficient to reduce activity of most cortical cells and led to the inactivation of almost the entire auditory region. When the temperature of thalamus, midbrain, and middle ear were measured directly during cortical cooling, there was a small drop in temperature (about 4°C but this was not sufficient to directly reduce neural activity. In an effort to visualise the extent of neural inactivation we measured the uptake of thallium ions following an intravenous injection. This confirmed that there was a large reduction of activity across much of the ipsilateral cortex and only a small reduction in subcortical structures.

  19. Variations in the radiation sensitivity of foodborne pathogens associated with complex ready-to-eat food products

    International Nuclear Information System (INIS)

    Sommers, Christopher H.; Boyd, Glenn

    2006-01-01

    Foodborne illness outbreaks and product recalls are occasionally associated with ready-to-eat (RTE) sandwiches and other 'heat and eat' multi-component RTE products. Ionizing radiation can inactivate foodborne pathogens on meat and poultry, fruits and vegetables, seafood, and RTE meat products. However, less data are available on the ability of low-dose ionizing radiation, doses under 5 kGy typically used for pasteurization purposes, to inactivate pathogenic bacteria on complex multi-component food products. In this study, the efficacy of ionizing radiation to inactivate Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, and Yersinia enterocolitica on RTE foods including a 'frankfurter on a roll', a 'beef cheeseburger on a bun' and a 'vegetarian cheeseburger on a bun' was investigated. The average D-10 values, the radiation dose needed to inactivate 1 log 1 of pathogen, by bacterium species, were 0.61, 0.54, 0.47, 0.36 and 0.15 kGy for Salmonella spp., S. aureus, L. monocytogenes, E. coli O157:H7, and Y. enterocolitica, respectively when inoculated onto the three product types. These results indicate that irradiation may be an effective means for inactivating common foodborne pathogens including Salmonella spp, S. aureus, L. monocytogenes, E. coli O157:H7 and Y. enterocolitica in complex RTE food products such as 'heat and eat' sandwich products

  20. Variations in the radiation sensitivity of foodborne pathogens associated with complex ready-to-eat food products

    Science.gov (United States)

    Sommers, Christopher H.; Boyd, Glenn

    2006-07-01

    Foodborne illness outbreaks and product recalls are occasionally associated with ready-to-eat (RTE) sandwiches and other "heat and eat" multi-component RTE products. Ionizing radiation can inactivate foodborne pathogens on meat and poultry, fruits and vegetables, seafood, and RTE meat products. However, less data are available on the ability of low-dose ionizing radiation, doses under 5 kGy typically used for pasteurization purposes, to inactivate pathogenic bacteria on complex multi-component food products. In this study, the efficacy of ionizing radiation to inactivate Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, and Yersinia enterocolitica on RTE foods including a "frankfurter on a roll", a "beef cheeseburger on a bun" and a "vegetarian cheeseburger on a bun" was investigated. The average D-10 values, the radiation dose needed to inactivate 1 log 10 of pathogen, by bacterium species, were 0.61, 0.54, 0.47, 0.36 and 0.15 kGy for Salmonella spp., S. aureus, L. monocytogenes, E. coli O157:H7, and Y. enterocolitica, respectively when inoculated onto the three product types. These results indicate that irradiation may be an effective means for inactivating common foodborne pathogens including Salmonella spp, S. aureus, L. monocytogenes, E. coli O157:H7 and Y. enterocolitica in complex RTE food products such as 'heat and eat" sandwich products.

  1. Unraveling plant responses to bacterial pathogens through proteomics

    KAUST Repository

    Zimaro, Tamara

    2011-11-03

    Plant pathogenic bacteria cause diseases in important crops and seriously and negatively impact agricultural production. Therefore, an understanding of the mechanisms by which plants resist bacterial infection at the stage of the basal immune response or mount a successful specific R-dependent defense response is crucial since a better understanding of the biochemical and cellular mechanisms underlying these interactions will enable molecular and transgenic approaches to crops with increased biotic resistance. In recent years, proteomics has been used to gain in-depth understanding of many aspects of the host defense against pathogens and has allowed monitoring differences in abundance of proteins as well as posttranscriptional and posttranslational processes, protein activation/inactivation, and turnover. Proteomics also offers a window to study protein trafficking and routes of communication between organelles. Here, we summarize and discuss current progress in proteomics of the basal and specific host defense responses elicited by bacterial pathogens. Copyright 2011 Tamara Zimaro et al.

  2. Unraveling plant responses to bacterial pathogens through proteomics

    KAUST Repository

    Zimaro, Tamara; Gottig, Natalia; Garavaglia, Betiana S.; Gehring, Christoph A; Ottado, Jorgelina

    2011-01-01

    Plant pathogenic bacteria cause diseases in important crops and seriously and negatively impact agricultural production. Therefore, an understanding of the mechanisms by which plants resist bacterial infection at the stage of the basal immune response or mount a successful specific R-dependent defense response is crucial since a better understanding of the biochemical and cellular mechanisms underlying these interactions will enable molecular and transgenic approaches to crops with increased biotic resistance. In recent years, proteomics has been used to gain in-depth understanding of many aspects of the host defense against pathogens and has allowed monitoring differences in abundance of proteins as well as posttranscriptional and posttranslational processes, protein activation/inactivation, and turnover. Proteomics also offers a window to study protein trafficking and routes of communication between organelles. Here, we summarize and discuss current progress in proteomics of the basal and specific host defense responses elicited by bacterial pathogens. Copyright 2011 Tamara Zimaro et al.

  3. Some factors affecting urokinase inactivation. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, Hiroo; Iketa, Yoshito

    1985-10-01

    The enzymatic activity of urokinase adsorbed on various polymer surfaces was measured to study the interaction between protein and polymers. The polymer films on which urokinase was adsorbed were exposed to either a high temperature or ..gamma..-radiation. The thermal inactivation rates were higher on hydrophobic polymers such as poly(ethylene terephthalate), nylon 6, and poly(vinylidene fluoride) than hydrophilic polymers like cellulose and ethylene-vinyl alcohol copolymer, indicating their substantial dependence on the interfacial free energy between the polymer and water. A similar dependence was also seen for the ..gamma..-radiation inactivation. Urokinase adsorbed on the hydrophobic polymers lost more easily its enzymatic activity by exposure to ..gamma..-radiation. The interfacial free energy seems to be one of the driving forces to denaturate proteins on polymers.

  4. Inactivation of biological substances by local heating

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Masahiro [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1982-09-01

    Mechanism of inactivation of biological substances caused by local heating was investigated. The effect of hot-zone formation by local heating on reaction of radicals was previously evaluated. The thermal increase in a hot zone due to low energy LET x-rays had little effect on reactibility of the radicals, but, in a hot zone caused by high energy LET x-rays, formed radicals seemed immediately react to active biological molecules to inactivate them. Direct thermal effect on biological molecules was analysed. Thermal increase in a hot zone may induce degenaration of biological molecules which seems to occur in a short time judged from the extension of a hot zone and the duration of high temperature.

  5. Immunogenicity of UV-inactivated measles virus

    International Nuclear Information System (INIS)

    Zahorska, R.; Mazur, N.; Korbecki, M.

    1978-01-01

    By means of the antigen extinction limit test it was shown that a triple dose vaccination of guinea pigs with UV-inactivated measles virus gave better results, than a single dose vaccination which was proved by the very low immunogenicity index. For both vaccination schemes (single and triple) the immune response was only sligthly influenced by a change of dose from 10 5 to 10 6 HadU 50 /ml or by the addition of aluminum adjuvant. In the antigen extinction limit test the antibody levels were determined by two methods (HIT and NT) the results of which were statistically equivalent. The UV-inactivated measles virus was also found to induce hemolysis-inhibiting antibodies. (orig.) [de

  6. Inactivation of Smad4 in gastric carcinomas.

    Science.gov (United States)

    Powell, S M; Harper, J C; Hamilton, S R; Robinson, C R; Cummings, O W

    1997-10-01

    Allelic loss of chromosome 18q has been noted in intestinal type gastric adenocarcinomas. Smad4 is a gene located at 18q that was recently cloned in humans and found to be significantly altered in pancreatic cancers. We sought to determine whether Smad4 genetic alterations played a significant role in gastric tumorigenesis by studying 35 gastric adenocarcinomas of all histopathological types and pathological stages. Microdissected specimens were used for mutational analysis of Smad4 at the nucleotide level, including the entire coding region and intron/exon boundaries. Allelic imbalance was also analyzed at the Smad4 locus using two nearby microsatellite markers. One case of apparent biallelic inactivation of Smad4 was found in our study of 35 gastric carcinomas. A nonsense point mutation at codon 334 was demonstrated, which, similar to other Smad4 mutations, is predicted to truncate the conserved COOH-terminal domain of this protein. This Smad4 C to T transition mutation was proven to be somatically acquired. Allelic loss was also noted on chromosome 18q at a marker near Smad4 in this mutated gastric cancer, apparently producing complete inactivation of Smad4 in this tumor. Significant 18q allelic loss (56% of 34 informative cases) was noted in our gastric carcinomas using microsatellite markers near the Smad4 locus, regardless of histological subtype or pathological stage. Additionally, three cases of microsatellite instability were observed. Thus, Smad4 inactivation was noted in our gastric carcinomas; however, this event was rare. The frequent loss of chromosomal arm 18q observed in gastric cancers suggests the presence of other tumor suppressor genes in this region that are involved in gastric tumorigenesis. Further studies are needed to identify these other targets of inactivation during gastric cancer development.

  7. Female meiotic sex chromosome inactivation in chicken.

    Directory of Open Access Journals (Sweden)

    Sam Schoenmakers

    2009-05-01

    Full Text Available During meiotic prophase in male mammals, the heterologous X and Y chromosomes remain largely unsynapsed, and meiotic sex chromosome inactivation (MSCI leads to formation of the transcriptionally silenced XY body. In birds, the heterogametic sex is female, carrying Z and W chromosomes (ZW, whereas males have the homogametic ZZ constitution. During chicken oogenesis, the heterologous ZW pair reaches a state of complete heterologous synapsis, and this might enable maintenance of transcription of Z- and W chromosomal genes during meiotic prophase. Herein, we show that the ZW pair is transiently silenced, from early pachytene to early diplotene using immunocytochemistry and gene expression analyses. We propose that ZW inactivation is most likely achieved via spreading of heterochromatin from the W on the Z chromosome. Also, persistent meiotic DNA double-strand breaks (DSBs may contribute to silencing of Z. Surprisingly, gammaH2AX, a marker of DSBs, and also the earliest histone modification that is associated with XY body formation in mammalian and marsupial spermatocytes, does not cover the ZW during the synapsed stage. However, when the ZW pair starts to desynapse, a second wave of gammaH2AX accumulates on the unsynapsed regions of Z, which also show a reappearance of the DSB repair protein RAD51. This indicates that repair of meiotic DSBs on the heterologous part of Z is postponed until late pachytene/diplotene, possibly to avoid recombination with regions on the heterologously synapsed W chromosome. Two days after entering diplotene, the Z looses gammaH2AX and shows reactivation. This is the first report of meiotic sex chromosome inactivation in a species with female heterogamety, providing evidence that this mechanism is not specific to spermatogenesis. It also indicates the presence of an evolutionary force that drives meiotic sex chromosome inactivation independent of the final achievement of synapsis.

  8. Inactivation of Anandamide Signaling: A Continuing Debate

    Directory of Open Access Journals (Sweden)

    Wael E. Houssen

    2010-10-01

    Full Text Available Since the first endocannabinoid anandamide was identified in 1992, extensive research has been conducted to characterize the elements of the tightly controlled endocannabinoid signaling system. While it was established that the activity of endocannabinoids are terminated by a two-step process that includes cellular uptake and degradation, there is still a continuing debate about the mechanistic role of these processes in inactivating anandamide signals.

  9. Epigenetic inactivation of CHFR in human tumors

    OpenAIRE

    Toyota, Minoru; Sasaki, Yasushi; Satoh, Ayumi; Ogi, Kazuhiro; Kikuchi, Takefumi; Suzuki, Hiromu; Mita, Hiroaki; Tanaka, Nobuyuki; Itoh, Fumio; Issa, Jean-Pierre J.; Jair, Kam-Wing; Schuebel, Kornel E.; Imai, Kohzoh; Tokino, Takashi

    2003-01-01

    Cell-cycle checkpoints controlling the orderly progression through mitosis are frequently disrupted in human cancers. One such checkpoint, entry into metaphase, is regulated by the CHFR gene encoding a protein possessing forkhead-associated and RING finger domains as well as ubiquitin–ligase activity. Although defects in this checkpoint have been described, the molecular basis and prevalence of CHFR inactivation in human tumors are still not fully understood. To address this question, w...

  10. Inactivation of human norovirus using chemical sanitizers.

    Science.gov (United States)

    Kingsley, David H; Vincent, Emily M; Meade, Gloria K; Watson, Clytrice L; Fan, Xuetong

    2014-02-03

    The porcine gastric mucin binding magnetic bead (PGM-MB) assay was used to evaluate the ability of chlorine, chlorine dioxide, peroxyacetic acid, hydrogen peroxide, and trisodium phosphate to inactivate human norovirus within 10% stool filtrate. One-minute free chlorine treatments at concentrations of 33 and 189 ppm reduced virus binding in the PGM-MB assay by 1.48 and 4.14 log₁₀, respectively, suggesting that chlorine is an efficient sanitizer for inactivation of human norovirus (HuNoV). Five minute treatments with 5% trisodium phosphate (pH~12) reduced HuNoV binding by 1.6 log₁₀, suggesting that TSP, or some other high pH buffer, could be used to treat food and food contact surfaces to reduce HuNoV. One minute treatments with 350 ppm chlorine dioxide dissolved in water did not reduce PGM-MB binding, suggesting that the sanitizer may not be suitable for HuNoV inactivation in liquid form. However a 60-min treatment with 350 ppm chlorine dioxide did reduce human norovirus by 2.8 log₁₀, indicating that chlorine dioxide had some, albeit limited, activity against HuNoV. Results also suggest that peroxyacetic acid has limited effectiveness against human norovirus, since 1-min treatments with up to 195 ppm reduced human norovirus binding by chlorine (sodium hypochlorite) as a HuNoV disinfectant wherever possible. Copyright © 2013. Published by Elsevier B.V.

  11. Radical inactivation of a biological sulphydryl molecule

    International Nuclear Information System (INIS)

    Lin, W.S.; Lal, M.; Gaucher, G.M.; Armstrong, D.A.

    1977-01-01

    Reactive species produced from the free radical-induced chain oxidation of low molecular weight sulphydryl-containing molecules in aerated solutions deactivate the sulphydryl-containing enzyme papain, forming both reparable mixed disulphides and non-reparable products. This inactivation is highly efficient for penicillamine and glutathione, but almost negligible with cysteine, which is a protector of papain for [cysteine] / [papain] >= 5 under all conditions used. In the case of glutathione, superoxide dismutase caused only a small reduction in the inactivation and peroxide yields were small, implying that the deactivating species are not .O 2 - but RSOO. radicals or products from them. For penicillamine, however, dimutase was highly effective and the peroxide yields were relatively large, demonstrating that .O 2 - or a radical with similar capabilities for forming H 2 O 2 and being deactivated by dismutase was involved. Although in the presence of dismutase penicillamine is a better protector of non-reparable papain inactivation than glutathione, it suffers from a deficiency in that the papain-penicillamine mixed disulphide, which is always formed, cannot be repaired by spontaneous reaction with RSH molecules. (author)

  12. Sequential and Simultaneous Applications of UV and Chlorine for Adenovirus Inactivation.

    Science.gov (United States)

    Rattanakul, Surapong; Oguma, Kumiko; Takizawa, Satoshi

    2015-09-01

    Adenoviruses are water-borne human pathogens with high resistance to UV disinfection. Combination of UV treatment and chlorination could be an effective approach to deal with adenoviruses. In this study, human adenovirus 5 (HAdV-5) was challenged in a bench-scale experiment by separate applications of UV or chlorine and by combined applications of UV and chlorine in either a sequential or simultaneous manner. The treated samples were then propagated in human lung carcinoma epithelial cells to quantify the log inactivation of HAdV-5. When the processes were separate, a fluence of 100 mJ/cm(2) and a CT value of 0.02 mg min/L were required to achieve 2 log inactivation of HAdV-5 by UV disinfection and chlorination, respectively. Interestingly, synergistic effects on the HAdV-5 inactivation rates were found in the sequential process of chlorine followed by UV (Cl2-UV) (p simultaneous application of UV/Cl2. This implies that a pretreatment with chlorine may increase the sensitivity of the virus to the subsequent UV disinfection. In conclusion, this study suggests that the combined application of UV and chlorine could be an effective measure against adenoviruses as a multi-barrier approach in water disinfection.

  13. Immunogenicity of an electron beam inactivated Rhodococcus equi vaccine in neonatal foals.

    Directory of Open Access Journals (Sweden)

    Angela I Bordin

    Full Text Available Rhodococcus equi is an important pathogen of foals that causes severe pneumonia. To date, there is no licensed vaccine effective against R. equi pneumonia of foals. The objectives of our study were to develop an electron beam (eBeam inactivated vaccine against R. equi and evaluate its immunogenicity. A dose of eBeam irradiation that inactivated replication of R. equi while maintaining outer cell wall integrity was identified. Enteral administration of eBeam inactivated R. equi increased interferon-γ production by peripheral blood mononuclear cells in response to stimulation with virulent R. equi and generated naso-pharyngeal R. equi-specific IgA in newborn foals. Our results indicate that eBeam irradiated R. equi administered enterally produce cell-mediated and upper respiratory mucosal immune responses, in the face of passively transferred maternal antibodies, similar to those produced in response to enteral administration of live organisms (a strategy which previously has been documented to protect foals against intrabronchial infection with virulent R. equi. No evidence of adverse effects was noted among vaccinated foals.

  14. Influence of controlled atmosphere on thermal inactivation of Escherichia coli ATCC 25922 in almond powder.

    Science.gov (United States)

    Cheng, Teng; Li, Rui; Kou, Xiaoxi; Wang, Shaojin

    2017-06-01

    Heat controlled atmosphere (CA) treatments hold potential to pasteurize Salmonella enteritidis PT 30 in almonds. Nonpathogenic Escherichia coli ATCC 25922 was used as a surrogate species of pathogenic Salmonella for validation of thermal pasteurization to meet critical safety requirements. A controlled atmosphere/heating block system (CA-HBS) was used to rapidly determine thermal inactivation of E. coli ATCC 25922. D- and z-values of E. coli ATCC 25922 inoculated in almond powder were determined at four temperatures between 65 °C and 80 °C under different gas concentrations and heating rates. The results showed that D- and z-values of E. coli under CA treatment were significantly (P < 0.05) lower than those under regular atmosphere (RA) treatment at 4 given temperatures. Relatively higher CO 2 concentrations (20%) and lower O 2 concentrations (2%) were more effective to reduce thermal inactivation time. There were no significant differences in D-values of E. coli when heating rates were above 1 °C/min both in RA and CA treatments. But D-values significantly (P < 0.05) increased under RA treatment and decreased under CA treatment at lower heating rates. Combination of rapid heat and CA treatments could be a promising method for thermal inactivation of S. enteritidis PT 30 in almond powder. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Distinct Mutations Led to Inactivation of Type 1 Fimbriae Expression in Shigella spp.

    Science.gov (United States)

    Bravo, Verónica; Puhar, Andrea; Sansonetti, Philippe; Parsot, Claude; Toro, Cecilia S.

    2015-01-01

    Shigella spp. are responsible for bacillary dysentery in humans. The acquisition or the modification of the virulence plasmid encoding factors promoting entry of bacteria into and dissemination within epithelial cells was a critical step in the evolution of these bacteria from their Escherichia coli ancestor(s). Incorporation of genomic islands (GI) and gene inactivation also shaped interactions between these pathogens and their human host. Sequence analysis of the GI inserted next to the leuX tRNA gene in S. boydii, S. dysenteriae, S. flexneri, S. sonnei and enteroinvasive E. coli (EIEC) suggests that this region initially carried the fec, yjhATS and fim gene clusters. The fim cluster encoding type I fimbriae is systematically inactivated in both reference strains and clinical isolates and distinct mutations are responsible for this inactivation in at least three phylogenetic groups. To investigate consequences of the presence of fimbriae on the outcome of the interaction of Shigella with host cells, we used a S. flexneri strain harboring a plasmid encoding the E. coli fim operon. Production of fimbriae by this recombinant strain increased the ability of bacteria to adhere to and enter into epithelial cells and had no effect on their ability to disseminate from cell to cell. The observations that production of type I fimbriae increases invasion of epithelial cells and that independent mutations abolish fimbriae production in Shigella suggest that these mutations correspond to pathoadaptive events. PMID:25811616

  16. Distinct mutations led to inactivation of type 1 fimbriae expression in Shigella spp.

    Directory of Open Access Journals (Sweden)

    Verónica Bravo

    Full Text Available Shigella spp. are responsible for bacillary dysentery in humans. The acquisition or the modification of the virulence plasmid encoding factors promoting entry of bacteria into and dissemination within epithelial cells was a critical step in the evolution of these bacteria from their Escherichia coli ancestor(s. Incorporation of genomic islands (GI and gene inactivation also shaped interactions between these pathogens and their human host. Sequence analysis of the GI inserted next to the leuX tRNA gene in S. boydii, S. dysenteriae, S. flexneri, S. sonnei and enteroinvasive E. coli (EIEC suggests that this region initially carried the fec, yjhATS and fim gene clusters. The fim cluster encoding type I fimbriae is systematically inactivated in both reference strains and clinical isolates and distinct mutations are responsible for this inactivation in at least three phylogenetic groups. To investigate consequences of the presence of fimbriae on the outcome of the interaction of Shigella with host cells, we used a S. flexneri strain harboring a plasmid encoding the E. coli fim operon. Production of fimbriae by this recombinant strain increased the ability of bacteria to adhere to and enter into epithelial cells and had no effect on their ability to disseminate from cell to cell. The observations that production of type I fimbriae increases invasion of epithelial cells and that independent mutations abolish fimbriae production in Shigella suggest that these mutations correspond to pathoadaptive events.

  17. Advanced Analysis to Distinguish between Physical Decrease and Inactivation of Viable Phages in Aerosol by Quantitating Phage-Specific Particles.

    Science.gov (United States)

    Shimasaki, Noriko; Nojima, Yasuhiro; Sakakibara, Masaya; Kikuno, Ritsuko; Iizuka, Chiori; Okaue, Akira; Okuda, Shunji; Shinohara, Katsuaki

    2018-01-01

     Recent studies have investigated the efficacy of air-cleaning products against pathogens in the air. A standard method to evaluate the reduction in airborne viruses caused by an air cleaner has been established using a safe bacteriophage instead of pathogenic viruses; the reduction in airborne viruses is determined by counting the number of viable airborne phages by culture, after operating the air cleaner. The reduction in the number of viable airborne phages could be because of "physical decrease" or "inactivation". Therefore, to understand the mechanism of reduction correctly, an analysis is required to distinguish between physical decrease and inactivation. The purpose of this study was to design an analysis to distinguish between the physical decrease and inactivation of viable phi-X174 phages in aerosols. We established a suitable polymerase chain reaction (PCR) system by selecting an appropriate primer-probe set for PCR and validating the sensitivity, linearity, and specificity of the primer-probe set to robustly quantify phi-X174-specific airborne particles. Using this quantitative PCR system and culture assay, we performed a behavior analysis of the phage aerosol in a small chamber (1 m 3 ) at different levels of humidity, as humidity is known to affect the number of viable airborne phages. The results revealed that the reduction in the number of viable airborne phages was caused not only by physical decrease but also by inactivation under particular levels of humidity. Our study could provide an advanced analysis to differentiate between the physical decrease and inactivation of viable airborne phages.

  18. Difunctional bacteriophage conjugated with photosensitizers for Candida albicans-targeting photodynamic inactivation.

    Science.gov (United States)

    Dong, Shuai; Shi, Hongxi; Zhang, Xintong; Chen, Xi; Cao, Donghui; Mao, Chuanbin; Gao, Xiang; Wang, Li

    2018-01-01

    Candida albicans is the most prevalent fungal pathogen of the human microbiota, causing infections ranging from superficial infections of the skin to life-threatening systemic infections. Due to the increasing occurrence of antibiotic-resistant C. albicans strains, new approaches to control this pathogen are needed. Photodynamic inactivation is an emerging alternative to treat infections based on the interactions between visible light and photosensitisers, in which pheophorbide a (PPA) is a chlorophyll-based photosensitizer that could induce cell death after light irradiation. Due to PPA's phototoxicity and low efficiency, the main challenge is to implement photosensitizer cell targeting and attacking. In this study, PPA was conjugated with JM-phage by EDC/NHS crosslinking. UV-Vis spectra was used to determine the optimum conjugation percentages of PPA and JM-phage complex for photodynamic inactivation. After photodynamic inactivation, the efficacy of PPA-JM-phage was assessed by performing in vitro experiments, such as MTS assay, scanning electron microscopy, measurement of dysfunctional mitochondria, ROS accumulation, S cell arrest and apoptotic pathway. A single-chain variable-fragment phage (JM) with high affinity to MP65 was screened from human single-fold single-chain variable-fragment libraries and designed as a binding target for C. albicans cells. Subsequently, PPa was integrated into JM phage to generate a combined nanoscale material, which was called PPA-JM-phage. After photodynamic inactivation, the growth of C. albicans was inhibited by PPA-JM-phage and apoptosis was observed. Scanning electron microscopy analysis revealed shrinking and rupturing of C. albicans . We also found that depolarization of mitochondrial membrane potential was decreased and intracellular reactive oxygen species levels were elevated significantly in C. albicans inhibited by PPA-JM-phage. Additionally, PPA-JM-phage also lead to S-phase arrest, and metacaspase activation

  19. Difunctional bacteriophage conjugated with photosensitizers for Candida albicans-targeting photodynamic inactivation

    Directory of Open Access Journals (Sweden)

    Dong S

    2018-04-01

    Full Text Available Shuai Dong,1,2 Hongxi Shi,1 Xintong Zhang,1,2 Xi Chen,1 Donghui Cao,2 Chuanbin Mao,3,4 Xiang Gao,1 Li Wang1 1Key Laboratory of Molecular Epigenetics of Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, 2First Hospital of Jilin University, Changchun, Jilin, 3School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China; 4Department of Chemistry and Biochemistry, Stephenson Life Science Research Center, University of Oklahoma, Norman, OK, USA Background: Candida albicans is the most prevalent fungal pathogen of the human microbiota, causing infections ranging from superficial infections of the skin to life-threatening systemic infections. Due to the increasing occurrence of antibiotic-resistant C. albicans strains, new approaches to control this pathogen are needed. Photodynamic inactivation is an emerging alternative to treat infections based on the interactions between visible light and photosensitisers, in which pheophorbide a (PPA is a chlorophyll-based photosensitizer that could induce cell death after light irradiation. Due to PPA’s phototoxicity and low efficiency, the main challenge is to implement photosensitizer cell targeting and attacking. Methods: In this study, PPA was conjugated with JM-phage by EDC/NHS crosslinking. UV-Vis spectra was used to determine the optimum conjugation percentages of PPA and JM-phage complex for photodynamic inactivation. After photodynamic inactivation, the efficacy of PPA-JM-phage was assessed by performing in vitro experiments, such as MTS assay, scanning electron microscopy, measurement of dysfunctional mitochondria, ROS accumulation, S cell arrest and apoptotic pathway.Results: A single-chain variable-fragment phage (JM with high affinity to MP65 was screened from human single-fold single-chain variable-fragment libraries and designed as a binding target for C. albicans cells. Subsequently, PPa was integrated into JM phage to generate

  20. AMPK in Pathogens.

    Science.gov (United States)

    Mesquita, Inês; Moreira, Diana; Sampaio-Marques, Belém; Laforge, Mireille; Cordeiro-da-Silva, Anabela; Ludovico, Paula; Estaquier, Jérôme; Silvestre, Ricardo

    2016-01-01

    During host-pathogen interactions, a complex web of events is crucial for the outcome of infection. Pathogen recognition triggers powerful cellular signaling events that is translated into the induction and maintenance of innate and adaptive host immunity against infection. In opposition, pathogens employ active mechanisms to manipulate host cell regulatory pathways toward their proliferation and survival. Among these, subversion of host cell energy metabolism by pathogens is currently recognized to play an important role in microbial growth and persistence. Extensive studies have documented the role of AMP-activated protein kinase (AMPK) signaling, a central cellular hub involved in the regulation of energy homeostasis, in host-pathogen interactions. Here, we highlight the most recent advances detailing how pathogens hijack cellular metabolism by suppressing or increasing the activity of the host energy sensor AMPK. We also address the role of lower eukaryote AMPK orthologues in the adaptive process to the host microenvironment and their contribution for pathogen survival, differentiation, and growth. Finally, we review the effects of pharmacological or genetic AMPK modulation on pathogen growth and persistence.

  1. Potatoes, pathogens and pests

    NARCIS (Netherlands)

    Lazebnik, Jenny

    2017-01-01

    Currently, fungicides are necessary to protect potato crops against late blight, Phytophthora infestans, one of the world’s most damaging crop pathogens. The introgression of plant resistance genes from wild potato species targeted specifically to the late blight pathogen into

  2. Food-borne pathogens

    International Nuclear Information System (INIS)

    Niemand, J.G.

    1985-01-01

    The Salmonella scare reinforced the importance of never taking chances when it comes to controlling pathogens. The issue has been resolved by radurisation. The article deals with the various pathogens that can effect food and argues the case for radurisation in dealing with them. It also looks at some of the other food products that can be treated using this process

  3. Optimizing supercritical carbon dioxide in the inactivation of bacteria in clinical solid waste by using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Md. Sohrab [Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Nik Ab Rahman, Nik Norulaini [School of Distance Education, Universiti Sains Malaysia, 11800 Penang (Malaysia); Balakrishnan, Venugopal [Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800 Penang (Malaysia); Alkarkhi, Abbas F.M. [Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Ahmad Rajion, Zainul [School of Dental Science, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Ab Kadir, Mohd Omar, E-mail: akmomar@usm.my [Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2015-04-15

    Highlights: • Supercritical carbon dioxide sterilization of clinical solid waste. • Inactivation of bacteria in clinical solid waste using supercritical carbon dioxide. • Reduction of the hazardous exposure of clinical solid waste. • Optimization of the supercritical carbon dioxide experimental conditions. - Abstract: Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO{sub 2}) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and gram-negative Escherichia coli in CSW. The effects of SC-CO{sub 2} sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20 MPa, 60 °C, and 60 min. The SC-CO{sub 2}-treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO{sub 2} exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials.

  4. Far-UVC light applications: sterilization of MRSA on a surface and inactivation of aerosolized influenza virus

    Science.gov (United States)

    Welch, David; Buonanno, Manuela; Shuryak, Igor; Randers-Pehrson, Gerhard; Spotnitz, Henry M.; Brenner, David J.

    2018-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) and influenza A virus are two of the major targets for new antimicrobial technologies. In contrast to conventional germicidal lamps emitting primarily at 254 nm, which are both carcinogenic and cataractogenic, recent work has shown the potential of far-UVC technology, mainly between 207 and 222 nm, to be an effective means of sterilization of pathogens without apparent harm to mammalian cells. This is because, due to its strong absorbance in biological materials, far-UVC light cannot penetrate even the outer (non living) layers of human skin or eye; however, because bacteria and viruses are of micrometer or smaller dimensions, far-UVC can penetrate and inactivate them. With this report, we present progress on in vitro tests to inactivate MRSA on a surface using far-UVC light from a laser delivered using an optical diffuser. Qualitative and quantitative results show that this means of far-UVC exposure is adequate to inactivate MRSA with a dose comparable to that which would be required using a conventional germicidal lamp. Also included is a report on progress on inactivation of aerosolized influenza A virus. A custom benchtop aerosol exposure chamber was constructed and used to determine the effectiveness of far- UVC. Results indicate that far-UVC efficiently inactivates airborne aerosolized viruses, with a very low dose of 2 mJ/cm2 of 222-nm light inactivating >95% of aerosolized H1N1 influenza virus. Together these studies help to further establish far-UVC technology as a promising, safe and inexpensive tool for sterilization in many environments.

  5. Optimizing supercritical carbon dioxide in the inactivation of bacteria in clinical solid waste by using response surface methodology

    International Nuclear Information System (INIS)

    Hossain, Md. Sohrab; Nik Ab Rahman, Nik Norulaini; Balakrishnan, Venugopal; Alkarkhi, Abbas F.M.; Ahmad Rajion, Zainul; Ab Kadir, Mohd Omar

    2015-01-01

    Highlights: • Supercritical carbon dioxide sterilization of clinical solid waste. • Inactivation of bacteria in clinical solid waste using supercritical carbon dioxide. • Reduction of the hazardous exposure of clinical solid waste. • Optimization of the supercritical carbon dioxide experimental conditions. - Abstract: Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO 2 ) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and gram-negative Escherichia coli in CSW. The effects of SC-CO 2 sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20 MPa, 60 °C, and 60 min. The SC-CO 2 -treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO 2 exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials

  6. Protection against avian metapneumovirus subtype C in turkeys immunized via the respiratory tract with inactivated virus.

    Science.gov (United States)

    Cha, Ra Mi; Khatri, Mahesh; Sharma, Jagdev M

    2011-01-10

    Avian metapneumovirus subtype C (aMPV/C) causes a severe upper respiratory tract (URT) infection in turkeys. Turkeys were inoculated oculonasally with inactivated aMPV/C adjuvanted with synthetic double-stranded RNA polyriboinosinic polyribocytidylic acid (Poly IC). Immunized turkeys had elevated numbers of mucosal IgA+ cells in the URT and increased levels of virus-specific IgG and IgA in the lachrymal fluid and IgG in the serum. After 7 or 21 days post immunization, turkeys were challenged oculonasally with pathogenic aMPV/C. Immunized groups were protected against respiratory lesions induced by the challenge virus. Further, the viral copy number of the challenge virus in the URT were significantly lower in the immunized turkeys than in the unimmunized turkeys (P<0.05). These results showed that inactivated aMPV/C administered by the respiratory route induced protective immunity against pathogenic virus challenge. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Mechanism of bacterial inactivation by (+-limonene and its potential use in food preservation combined processes.

    Directory of Open Access Journals (Sweden)

    Laura Espina

    Full Text Available This work explores the bactericidal effect of (+-limonene, the major constituent of citrus fruits' essential oils, against E. coli. The degree of E. coli BJ4 inactivation achieved by (+-limonene was influenced by the pH of the treatment medium, being more bactericidal at pH 4.0 than at pH 7.0. Deletion of rpoS and exposure to a sub-lethal heat or an acid shock did not modify E. coli BJ4 resistance to (+-limonene. However, exposure to a sub-lethal cold shock decreased its resistance to (+-limonene. Although no sub-lethal injury was detected in the cell envelopes after exposure to (+-limonene by the selective-plating technique, the uptake of propidium iodide by inactivated E. coli BJ4 cells pointed out these structures as important targets in the mechanism of action. Attenuated Total Reflectance Infrared Microspectroscopy (ATR-IRMS allowed identification of altered E. coli BJ4 structures after (+-limonene treatments as a function of the treatment pH: β-sheet proteins at pH 4.0 and phosphodiester bonds at pH 7.0. The increased sensitivity to (+-limonene observed at pH 4.0 in an E. coli MC4100 lptD4213 mutant with an increased outer membrane permeability along with the identification of altered β-sheet proteins by ATR-IRMS indicated the importance of this structure in the mechanism of action of (+-limonene. The study of mechanism of inactivation by (+-limonene led to the design of a synergistic combined process with heat for the inactivation of the pathogen E. coli O157:H7 in fruit juices. These results show the potential of (+-limonene in food preservation, either acting alone or in combination with lethal heat treatments.

  8. Mechanism of Bacterial Inactivation by (+)-Limonene and Its Potential Use in Food Preservation Combined Processes

    Science.gov (United States)

    Espina, Laura; Gelaw, Tilahun K.; de Lamo-Castellví, Sílvia; Pagán, Rafael; García-Gonzalo, Diego

    2013-01-01

    This work explores the bactericidal effect of (+)-limonene, the major constituent of citrus fruits' essential oils, against E. coli. The degree of E. coli BJ4 inactivation achieved by (+)-limonene was influenced by the pH of the treatment medium, being more bactericidal at pH 4.0 than at pH 7.0. Deletion of rpoS and exposure to a sub-lethal heat or an acid shock did not modify E. coli BJ4 resistance to (+)-limonene. However, exposure to a sub-lethal cold shock decreased its resistance to (+)-limonene. Although no sub-lethal injury was detected in the cell envelopes after exposure to (+)-limonene by the selective-plating technique, the uptake of propidium iodide by inactivated E. coli BJ4 cells pointed out these structures as important targets in the mechanism of action. Attenuated Total Reflectance Infrared Microspectroscopy (ATR-IRMS) allowed identification of altered E. coli BJ4 structures after (+)-limonene treatments as a function of the treatment pH: β-sheet proteins at pH 4.0 and phosphodiester bonds at pH 7.0. The increased sensitivity to (+)-limonene observed at pH 4.0 in an E. coli MC4100 lptD4213 mutant with an increased outer membrane permeability along with the identification of altered β-sheet proteins by ATR-IRMS indicated the importance of this structure in the mechanism of action of (+)-limonene. The study of mechanism of inactivation by (+)-limonene led to the design of a synergistic combined process with heat for the inactivation of the pathogen E. coli O157:H7 in fruit juices. These results show the potential of (+)-limonene in food preservation, either acting alone or in combination with lethal heat treatments. PMID:23424676

  9. Inactivation of Template-Directed Misfolding of Infectious Prion Protein by Ozone

    Science.gov (United States)

    Ding, Ning; Price, Luke M.; Braithwaite, Shannon L.; Balachandran, Aru; Belosevic, Miodrag

    2012-01-01

    Misfolded prions (PrPSc) are well known for their resistance to conventional decontamination processes. The potential risk of contamination of the water environment, as a result of disposal of specified risk materials (SRM), has raised public concerns. Ozone is commonly utilized in the water industry for inactivation of microbial contaminants and was tested in this study for its ability to inactivate prions (263K hamster scrapie = PrPSc). Treatment variables included initial ozone dose (7.6 to 25.7 mg/liter), contact time (5 s and 5 min), temperature (4°C and 20°C), and pH (pH 4.4, 6.0, and 8.0). Exposure of dilute suspensions of the infected 263K hamster brain homogenates (IBH) (0.01%) to ozone resulted in the in vitro destruction of the templating properties of PrPSc, as measured by the protein misfolding cyclic amplification (PMCA) assay. The highest levels of prion inactivation (≥4 log10) were observed with ozone doses of 13.0 mg/liter, at pH 4.4 and 20°C, resulting in a CT (the product of residual ozone concentration and contact time) value as low as 0.59 mg · liter−1 min. A comparison of ozone CT requirements among various pathogens suggests that prions are more susceptible to ozone degradation than some model bacteria and protozoa and that ozone treatment may be an effective solution for inactivating prions in water and wastewater. PMID:22138993

  10. Heat inactivation of Salmonella spp. in fresh poultry compost by simulating early phase of composting process.

    Science.gov (United States)

    Singh, R; Kim, J; Jiang, X

    2012-05-01

    The purpose of this study was to determine the effect of moisture on thermal inactivation of Salmonella spp. in poultry litter under optimal composting conditions. Thermal inactivation of Salmonella was studied in fresh poultry compost by simulating early phase of composting process. A mixture of three Salmonella serotypes grown in Tryptic soy broth with rifampin (TSB-R) was inoculated in fresh compost with 40 or 50% moisture at a final concentration of c. 7 log CFU g(-1). The inoculated compost was kept in an environmental chamber which was programmed to rise from room temperature to target composting temperatures in 2 days. In poultry compost with optimal moisture content (50%), Salmonella spp. survived for 96, 72 and 24 h at 50, 55 and 60°C, respectively, as compared with 264, 144 and 72 h at 50, 55 and 60°C, respectively, in compost with suboptimal moisture (40%). Pathogen decline was faster during the come-up time owing to higher ammonia volatilization. Our results demonstrated that Salmonella spp. survived longer in fresh poultry compost with suboptimal moisture of 40% than in compost with optimal moisture of 50% during thermophilic composting. High nitrogen content of the poultry compost is an additional factor contributing to Salmonella inactivation through ammonia volatilization during thermal exposure. This research validated the effectiveness of the current composting guidelines on Salmonella inactivation in fresh poultry compost. Both initial moisture level and ammonia volatilization are important factors affecting microbiological safety and quality of compost product. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  11. Chlorine inactivation of Tubifex tubifex in drinking water and the synergistic effect of sequential inactivation with UV irradiation and chlorine.

    Science.gov (United States)

    Nie, Xiao-Bao; Li, Zhi-Hong; Long, Yuan-Nan; He, Pan-Pan; Xu, Chao

    2017-06-01

    The inactivation of Tubifex tubifex is important to prevent contamination of drinking water. Chlorine is a widely-used disinfectant and the key factor in the inactivation of T. tubifex. This study investigated the inactivation kinetics of chlorine on T. tubifex and the synergistic effect of the sequential use of chlorine and UV irradiation. The experimental results indicated that the Ct (concentration × time reaction ) concept could be used to evaluate the inactivation kinetics of T. tubifex with chlorine, thus allowing for the use of a simpler Ct approach for the assessment of T. tubifex chlorine inactivation requirements. The inactivation kinetics of T. tubifex by chlorine was found to be well-fitted to a delayed pseudo first-order Chick-Watson expression. Sequential experiments revealed that UV irradiation and chlorine worked synergistically to effectively inactivate T. tubifex as a result of the decreased activation energy, E a , induced by primary UV irradiation. Furthermore, the inactivation effectiveness of T. tubifex by chlorine was found to be affected by several drinking water quality parameters including pH, turbidity, and chemical oxygen demand with potassium permanganate (COD Mn ) concentration. High pH exhibited pronounced inactivation effectiveness and the decrease in turbidity and COD Mn concentrations contributed to the inactivation of T. tubifex. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Inactivation of Bacillus cereus by Na-chlorophyllin-based photosensitization on the surface of packaging.

    Science.gov (United States)

    Luksiene, Z; Buchovec, I; Paskeviciute, E

    2010-11-01

    This study was focused on the possibility to inactivate food-borne pathogen Bacillus cereus by Na-chlorophyllin (Na-Chl)-based photosensitization in vitro and after attachment to the surface of packaging material. Bacillus cereus in vitro or attached to the packaging was incubated with Na-Chl (7·5×10(-8) to 7·5×10(-5) mol l(-1) ) for 2-60min in phosphate buffer saline. Photosensitization was performed by illuminating cells under a light with a λ of 400nm and an energy density of 20mW cm(-2) . The illumination time varied 0-5min and subsequently the total energy dose was 0-6J cm(-2) . The results show that B. cereus vegetative cells in vitro or attached to the surface of packaging after incubation with 7·5×10(-7) mol l(-1) Na-Chl and following illumination were inactivated by 7log. The photoinactivation of B. cereus spores in vitro by 4log required higher (7·5×10(-6) mol l(-1) ) Na-Chl concentration. Decontamination of packaging material from attached spores by photosensitization reached 5log at 7·5×10(-5) mol l(-1) Na-Chl concentration. Comparative analysis of different packaging decontamination treatments indicates that washing with water can diminish pathogen population on the surface by packaging material. Spores are more resistant than vegetative cells to photosensitization-based inactivation. Comparison of different surface decontamination treatments indicates that Na-Chl-based photosensitization is much more effective antibacterial tool than washing with water or 200ppm Na-hypochlorite. Our data support the idea that Na-Chl-based photosensitization has great potential for future application as an environment-friendly, nonthermal surface decontamination technique. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  13. Foodborne Pread of Hepatitis A: Recent Studies on Virus Survival, Transfer and Inactivation

    Directory of Open Access Journals (Sweden)

    Syed A Sattar

    2000-01-01

    Full Text Available Hepatitis A virus (HAV is responsible for considerable morbidity and economic losses worldwide, and is the only reportable, foodborne viral pathogen in Canada. Outbreaks caused by it occur more frequently in settings such as hospitals, daycare centres, schools, and in association with foods and food service establishments. In recent years, the incidence of hepatitis A has increased in Canada. Many factors, including changing lifestyles and demographics, faster and more frequent travel, and enhanced importation of foods from hepatitis A-endemic regions, may be behind this increase. Despite its increasing significance as a human pathogen, not much was known until recently about the survival and inactivation of HAV, and even less was understood about the effectiveness of measures to prevent and control its foodborne spread. Studies conducted in the past decade have shown that HAV can survive for several hours on human hands and for several days on environmental surfaces indoors. The virus can also retain its infectivity for several days on fruits and vegetables which are often consumed raw, and such imported items have already been incriminated in disease outbreaks. Casual contact between contaminated hands and clean food items can readily lead to a transfer of as much as 10% of the infectious virus. HAV is also relatively resistant to inactivation by heat, gamma irradiation and chemical germicides. In view of these findings, better approaches to prevent the contamination of foods with HAV and more effective methods for its inactivation in foods, on environmental surfaces and on the hands of food handlers are needed.

  14. Inactivation of Mycobacterium bovis ssp. caprae in high-temperature, short-term pasteurized pilot-plant milk.

    Science.gov (United States)

    Hammer, P; Richter, E; Rüsch-Gerdes, S; Walte, H-G C; Matzen, S; Kiesner, C

    2015-03-01

    Experiments to determine the efficacy of high temperature, short time (HTST) pasteurization of milk in terms of inactivation of pathogenic microorganisms were mainly performed between 1930 and 1960. Among the target organisms were Mycobacterium bovis and Mycobacterium tuberculosis. As a result, the Codex Alimentarius prescribes that HTST treatment of milk should lead to a significant reduction of pathogenic microorganisms during milk pasteurization. Due to the development of improved methods for the detection of survivors and of more advanced heating technology, verification of this requirement seemed to be necessary. To address recent outbreaks of tuberculosis in cattle caused by M. bovis ssp. caprae (M. caprae) in the southern regions of Germany, this organism was tested and compared with M. bovis ssp. bovis (M. bovis). Experiments were performed in a pilot plant for HTST pasteurization of milk with 3 strains of M. caprae and 1 strain of M. bovis. In preliminary trials at a fixed holding time of 25 s, the temperature at which significant inactivation occurred was 62.5°C for all strains. To determine D-values (decimal reduction times) for the inactivation kinetics, the strains were tested at 65, 62.5, and 60°C at holding times of 16.5, 25, and 35 s. At 65°C, the D-values of all strains ranged from 6.8 to 7.8 s, and at 62.5°C, D-values ranged from 14.5 to 18.1 s. Low inactivation was observed at 60°C. When the low slope of the inactivation curve allowed calculation of a D-value, these ranged from 40.8 to 129.9 s. In terms of log10 reductions, the highest values for all strains were 4.1 to 4.9 log at 65°C, with a holding time of 35 s. The tested strains of M. caprae and M. bovis showed similar low resistance to heat. Standard HTST treatment should result in a high reduction of these organisms and thus the requirements of the Codex Alimentarius for inactivation of pathogens by this process are far exceeded. Copyright © 2015 American Dairy Science Association

  15. Role of dopant concentration, crystal phase and particle size on microbial inactivation of Cu-doped TiO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Manoranjan; Wu Bing; Zhu Liying; Jacobson, Craig; Wang Weining; Jones, Kristen; Goyal, Yogesh; Tang, Yinjie J; Biswas, Pratim, E-mail: pbiswas@wustl.edu [Department of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, MO 63130 (United States)

    2011-10-14

    The properties of Cu-doped TiO{sub 2} nanoparticles (NPs) were independently controlled in a flame aerosol reactor by varying the molar feed ratios of the precursors, and by optimizing temperature and time history in the flame. The effect of the physico-chemical properties (dopant concentration, crystal phase and particle size) of Cu-doped TiO{sub 2} nanoparticles on inactivation of Mycobacterium smegmatis (a model pathogenic bacterium) was investigated under three light conditions (complete dark, fluorescent light and UV light). The survival rate of M. smegmatis (in a minimal salt medium for 2 h) exposed to the NPs varied depending on the light irradiation conditions as well as the dopant concentrations. In dark conditions, pristine TiO{sub 2} showed insignificant microbial inactivation, but inactivation increased with increasing dopant concentration. Under fluorescent light illumination, no significant effect was observed for TiO{sub 2}. However, when TiO{sub 2} was doped with copper, inactivation increased with dopant concentration, reaching more than 90% (>3 wt% dopant). Enhanced microbial inactivation by TiO{sub 2} NPs was observed only under UV light. When TiO{sub 2} NPs were doped with copper, their inactivation potential was promoted and the UV-resistant cells were reduced by over 99%. In addition, the microbial inactivation potential of NPs was also crystal-phase-and size-dependent under all three light conditions. A lower ratio of anatase phase and smaller sizes of Cu-doped TiO{sub 2} NPs resulted in decreased bacterial survival. The increased inactivation potential of doped TiO{sub 2} NPs is possibly due to both enhanced photocatalytic reactions and leached copper ions.

  16. X Inactivation and Progenitor Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ruben Agrelo

    2011-04-01

    Full Text Available In mammals, silencing of one of the two X chromosomes is necessary to achieve dosage compensation. The 17 kb non-coding RNA called Xist triggers X inactivation. Gene silencing by Xist can only be achieved in certain contexts such as in cells of the early embryo and in certain hematopoietic progenitors where silencing factors are present. Moreover, these epigenetic contexts are maintained in cancer progenitors in which SATB1 has been identified as a factor related to Xist-mediated chromosome silencing.

  17. Extracts against Various Pathogens

    Directory of Open Access Journals (Sweden)

    Ritika Chauhan

    2013-07-01

    The present study shows that tested lichen Parmotrema sp. extracts demonstrated a strong antimicrobial effect. That suggests the active components from methanol extracts of the investigated lichen Parmotrema sp. can be used as natural antimicrobial agent against pathogens.

  18. Evolution of microbial pathogens

    National Research Council Canada - National Science Library

    DiRita, Victor J; Seifert, H. Steven

    2006-01-01

    ... A. Hogan vvi ■ CONTENTS 8. Evolution of Pathogens in Soil Rachel Muir and Man-Wah Tan / 131 9. Experimental Models of Symbiotic Host-Microbial Relationships: Understanding the Underpinnings of ...

  19. Indicators for waterborne pathogens

    National Research Council Canada - National Science Library

    Committee on Indicators for Waterborne Pathogens, National Research Council

    2004-01-01

    ... not practical or feasible to monitor for the complete spectrum of microorganisms that may occur in water, and many known pathogens are difficult to detect directly and reliably in water samples.Â...

  20. Host–Pathogen Interactions

    NARCIS (Netherlands)

    Smits, M.A.; Schokker, D.J.

    2011-01-01

    The outcome of an infection is determined by numerous interactions between hosts and pathogens occurring at many different biological levels, ranging from molecule to population. To develop new control strategies for infectious diseases in livestock species, appropriate methodologies are needed

  1. Inactivation of soil-borne plant pathogens during small-scale composting of crop residues.

    NARCIS (Netherlands)

    Bollen, G.J.; Volker, D.; Wijnen, A.P.

    1989-01-01

    Monsters van hevig aangetaste gewasresten werden aangebracht in composthopen van het Indore-type. De temperatuur liep op tot 50-70 graden Celsius binnen 6 dagen na het opzetten van de hopen, afhankelijk van de aard van de gewasresten en de plaats in de hoop. De warmtefase duurde 2-3 weken en werd

  2. Processes to Preserve Spice and Herb Quality and Sensory Integrity During Pathogen Inactivation.

    Science.gov (United States)

    Duncan, Susan E; Moberg, Kayla; Amin, Kemia N; Wright, Melissa; Newkirk, Jordan J; Ponder, Monica A; Acuff, Gary R; Dickson, James S

    2017-05-01

    Selected processing methods, demonstrated to be effective at reducing Salmonella, were assessed to determine if spice and herb quality was affected. Black peppercorn, cumin seed, oregano, and onion powder were irradiated to a target dose of 8 kGy. Two additional processes were examined for whole black peppercorns and cumin seeds: ethylene oxide (EtO) fumigation and vacuum assisted-steam (82.22 °C, 7.5 psia). Treated and untreated spices/herbs were compared (visual, odor) using sensory similarity testing protocols (α = 0.20; β = 0.05; proportion of discriminators: 20%) to determine if processing altered sensory quality. Analytical assessment of quality (color, water activity, and volatile chemistry) was completed. Irradiation did not alter visual or odor sensory quality of black peppercorn, cumin seed, or oregano but created differences in onion powder, which was lighter (higher L * ) and more red (higher a * ) in color, and resulted in nearly complete loss of measured volatile compounds. EtO processing did not create detectable odor or appearance differences in black peppercorn; however visual and odor sensory quality differences, supported by changes in color (higher b * ; lower L * ) and increased concentrations of most volatiles, were detected for cumin seeds. Steam processing of black peppercorn resulted in perceptible odor differences, supported by increased concentration of monoterpene volatiles and loss of all sesquiterpenes; only visual differences were noted for cumin seed. An important step in process validation is the verification that no effect is detectable from a sensory perspective. © 2017 The Authors. Journal of Food Science published by Wiley Periodicals, Inc. on behalf of Institute of Food Technologists.

  3. Pulsed-plasma gas-discharge inactivation of microbial pathogens in chilled poultry wash water.

    Science.gov (United States)

    Rowan, N J; Espie, S; Harrower, J; Anderson, J G; Marsili, L; MacGregor, S J

    2007-12-01

    A pulsed-plasma gas-discharge (PPGD) system was developed for the novel decontamination of chilled poultry wash water. Treatment of poultry wash water in the plasma generation chamber for up to 24 s at 4 degrees C reduced Escherichia coli NCTC 9001, Campylobacter jejuni ATCC 33560, Campylobacter coli ATCC 33559, Listeria monocytogenes NCTC 9863, Salmonella enterica serovar Enteritidis ATCC 4931, and S. enterica serovar Typhimurium ATCC 14028 populations to non-detectable levels ( or = 3 log CFU/ml) in recalcitrant B. cereus NCTC 11145 endospore numbers within 30 s, the level of endospore reduction was dependent on the nature of the sparged gas used in the plasma treatments. Scanning electron microscopy revealed that significant damage occurred at the cellular level in PPGD-treated test organisms. This electrotechnology delivers energy in intense ultrashort bursts, generating products such as ozone, UV light, acoustic and shock waves, and pulsed electric fields that have multiple bactericidal properties. This technology offers an exciting complementary or alternative approach for treating raw poultry wash water and for preventing cross-contamination in processing environments.

  4. Inactivation of high concentration of pathogens in land-applied food ...

    African Journals Online (AJOL)

    2008-10-16

    Oct 16, 2008 ... In Mexico, as in other developing countries, the most important pollution and management problems of food-processing sludge are the high levels .... or ammonia is reduced due to its dilution in the water contained in sludge.

  5. Radiation inactivation of T7 phage

    International Nuclear Information System (INIS)

    Becker, D.; Redpath, J.L.; Grossweiner, L.I.

    1978-01-01

    The radiation inactivation of T7 phage by 25-MeV electron pulses has been measured in various media containing a wide concentration range of radical scavenging solutes and in the presence of protective and sensitizing agents. The dependence of sensitivity on pulse dose, from 1 mrad to 3.6 krad, is attributed to radical depletion via bimolecular processes. The survival data are analyzed by extending target theory to include diffusive reactions of primary and secondary radicals generated in the medium. It is concluded that OH radicals are the principal primary inactivating species and that secondary radicals from Br - , CNS - , uracil, glucose, ribose, sucrose, tyrosine, and histidine are lethal to some extent. In nutrient broth or 100 mM histidine, psoralen derivatives, Actinomycin D, and Mitomycin C are anoxic sensitizers. It is proposed that the psoralens promote the formation of non-strand break lesions as the sensitization mechanism. The target theory based on diffusional kinetics is applicable to other systems including single cells

  6. Instrument for Study of Microbial Thermal Inactivation

    Science.gov (United States)

    Dickerson, R. W.; Read, R. B.

    1968-01-01

    An instrument was designed for the study of thermal inactivation of microorganisms using heating times of less than 1 sec. The instrument operates on the principle of rapid automatic displacement of the microorganism to and from a saturated steam atmosphere, and the operating temperature range is 50 to 90 C. At a temperature of 70 C, thermometric lag (time required to respond to 63.2% of a step change) of the fluid sample containing microorganisms was 0.12 sec. Heating time required to heat the sample to within 0.1 C of the exposure temperature was less than 1 sec, permitting exposure periods as brief as 1 sec, provided the proper corrections are made for the lethal effect of heating. The instrument is most useful for heat exposure periods of less than 5 min, and, typically, more than 500 samples can be processed for microbial inactivation determinations within an 8-hr period. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 7 Fig. 8 PMID:4874466

  7. Influvac, a trivalent inactivated subunit influenza vaccine.

    Science.gov (United States)

    Zuccotti, Gian Vincenzo; Fabiano, Valentina

    2011-01-01

    Influenza represents a major sanitary and socio-economic burden and vaccination is universally considered the most effective strategy for preventing the disease and its complications. Traditional influenza vaccines have been on the market since the late 1940s, with million of doses administered annually worldwide, and demonstrated a substantial efficacy and safety. The trivalent inactivated subunit vaccine has been available for more than 25 years and has been studied in healthy children, adults and the elderly and in people affected by underlying chronic medical conditions. We describe vaccine technology focusing on subunit vaccine production procedures and mode of action and provide updated information on efficacy and safety available data. A review of efficacy and safety data in healthy subjects and in high risk populations from major sponsor- and investigator-driven studies. The vaccine showed a good immunogenicity and a favorable safety profile in all target groups. In the panorama of actually available influenza vaccines, trivalent inactivated subunit vaccine represents a well-established tool for preventing flu and the associated complications.

  8. IL26 gene inactivation in Equidae.

    Science.gov (United States)

    Shakhsi-Niaei, M; Drögemüller, M; Jagannathan, V; Gerber, V; Leeb, T

    2013-12-01

    Interleukin-26 (IL26) is a member of the IL10 cytokine family. The IL26 gene is located between two other well-known cytokines genes of this family encoding interferon-gamma (IFNG) and IL22 in an evolutionary conserved gene cluster. In contrast to humans and most other mammals, mice lack a functional Il26 gene. We analyzed the genome sequences of other vertebrates for the presence or absence of functional IL26 orthologs and found that the IL26 gene has also become inactivated in several equid species. We detected a one-base pair frameshift deletion in exon 2 of the IL26 gene in the domestic horse (Equus caballus), Przewalski horse (Equus przewalskii) and donkey (Equus asinus). The remnant IL26 gene in the horse is still transcribed and gives rise to at least five alternative transcripts. None of these transcripts share a conserved open reading frame with the human IL26 gene. A comparative analysis across diverse vertebrates revealed that the IL26 gene has also independently been inactivated in a few other mammals, including the African elephant and the European hedgehog. The IL26 gene thus appears to be highly variable, and the conserved open reading frame has been lost several times during mammalian evolution. © 2013 The Authors, Animal Genetics © 2013 Stichting International Foundation for Animal Genetics.

  9. Scale down of the inactivated polio vaccine production process

    NARCIS (Netherlands)

    Thomassen, Y.E.; Oever, van 't R.; Vinke, C.M.; Spiekstra, A.; Wijffels, R.H.; Pol, van der L.A.; Bakker, W.A.M.

    2013-01-01

    The anticipated increase in the demand for inactivated polio vaccines resulting from the success in the polio eradication program requires an increase in production capacity and cost price reduction of the current inactivated polio vaccine production processes. Improvement of existing production

  10. Thermal inactivation kinetics of β-galactosidase during bread baking

    NARCIS (Netherlands)

    Zhang, L.; Chen, Xiao Dong; Boom, R.M.; Schutyser, M.A.I.

    2017-01-01

    In this study, β-galactosidase was utilized as a model enzyme to investigate the mechanism of enzyme inactivation during bread baking. Thermal inactivation of β-galactosidase was investigated in a wheat flour/water system at varying temperature-moisture content combinations, and in bread during

  11. Quantum chromodynamics as the sequential fragmenting with inactivation

    International Nuclear Information System (INIS)

    Botet, R.

    1996-01-01

    We investigate the relation between the modified leading log approximation of the perturbative QCD and the sequential binary fragmentation process. We will show that in the absence of inactivation, this process is equivalent to the QCD gluodynamics. The inactivation term yields a precise prescription of how to include the hadronization in the QCD equations. (authors)

  12. Quantum chromodynamics as the sequential fragmenting with inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Botet, R. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique des Solides; Ploszajczak, M. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France)

    1996-12-31

    We investigate the relation between the modified leading log approximation of the perturbative QCD and the sequential binary fragmentation process. We will show that in the absence of inactivation, this process is equivalent to the QCD gluodynamics. The inactivation term yields a precise prescription of how to include the hadronization in the QCD equations. (authors). 15 refs.

  13. Mutual inactivation of Notch receptors and ligands facilitates developmental patterning.

    Directory of Open Access Journals (Sweden)

    David Sprinzak

    2011-06-01

    Full Text Available Developmental patterning requires juxtacrine signaling in order to tightly coordinate the fates of neighboring cells. Recent work has shown that Notch and Delta, the canonical metazoan juxtacrine signaling receptor and ligand, mutually inactivate each other in the same cell. This cis-interaction generates mutually exclusive sending and receiving states in individual cells. It generally remains unclear, however, how this mutual inactivation and the resulting switching behavior can impact developmental patterning circuits. Here we address this question using mathematical modeling in the context of two canonical pattern formation processes: boundary formation and lateral inhibition. For boundary formation, in a model motivated by Drosophila wing vein patterning, we find that mutual inactivation allows sharp boundary formation across a broader range of parameters than models lacking mutual inactivation. This model with mutual inactivation also exhibits robustness to correlated gene expression perturbations. For lateral inhibition, we find that mutual inactivation speeds up patterning dynamics, relieves the need for cooperative regulatory interactions, and expands the range of parameter values that permit pattern formation, compared to canonical models. Furthermore, mutual inactivation enables a simple lateral inhibition circuit architecture which requires only a single downstream regulatory step. Both model systems show how mutual inactivation can facilitate robust fine-grained patterning processes that would be difficult to implement without it, by encoding a difference-promoting feedback within the signaling system itself. Together, these results provide a framework for analysis of more complex Notch-dependent developmental systems.

  14. The pulsed light inactivation of veterinary relevant microbial biofilms ...

    African Journals Online (AJOL)

    Results show that both Cryptosporidium and Giardia attach to biofilms in large numbers (100-1000 oo/cysts) in as little as 72 hours. Pulsed light successfully inactivated all test species (Listeria, Salmonella, Bacillus, Escherichia) in planktonic and biofilm form with an increase in inactivation for every increase in UV dose.

  15. Ebola Virus Inactivation by Detergents Is Annulled in Serum

    NARCIS (Netherlands)

    van Kampen, Jeroen J. A.; Tintu, Andrei; Russcher, Henk; Fraaij, Pieter L. A.; Reusken, Chantal B. E. M.; Rijken, Mikel; van Hellemond, Jaap J.; van Genderen, Perry J. J.; Koelewijn, Rob; de Jong, Menno D.; Haddock, Elaine; Fischer, Robert J.; Munster, Vincent J.; Koopmans, Marion P. G.

    2017-01-01

    Treatment of blood samples from hemorrhagic fever virus (HFV)-infected patients with 0.1% detergents has been recommended for virus inactivation and subsequent safe laboratory testing. However, data on virus inactivation by this procedure are lacking. Here we show the effect of this procedure on

  16. Method of inactivating reproducible forms of mycoplasma in biological preparations

    International Nuclear Information System (INIS)

    Veber, P.; Jurmanova, K.; Lesko, J.; Hana, L.; Veber, V.

    1978-01-01

    Inactivation of mycoplasms in biological materials was achieved using gamma radiation with a dose rate of 1x10 4 to 5x10 6 rads/h for 1 to 250 hours. The technique is advantageous for allowing the inactivation of the final form of products (tablets, vaccines, etc.). (J.P.)

  17. Intervention strategies for control of foodborne pathogens

    Science.gov (United States)

    Juneja, Vijay K.

    2004-03-01

    The increasing numbers of illnesses associated with foodborne pathogens such as Listeria monocytogenes and Escherichia coli O157:H7, has renewed concerns about food safety because of consumer preferences for minimally processed foods that offer convenience in availability and preparation. Accordingly, the need for better control of foodborne pathogens has been paramount in recent years. Mechanical removal of microorganisms from food can be accomplished by centrifugation, filtration, trimming and washing. Cleaning and sanitation strategies can be used for minimizing the access of microorganisms in foods from various sources. Other strategies for control of foodborne pathogens include established physical microbiocidal treatments such as ionizing radiation and heating. Research has continued to demonstrate that food irradiation is a suitable process to control and possibly eliminate foodborne pathogens, for example Listeria monocytogenes and Escherichia coli O157:H7, from a number of raw and cooked meat and poultry products. Heat treatment is the most common method in use today for the inactivation of microorganisms. Microorganisms can also be destroyed by nonthermal treatments, such as application of high hydrostatic pressure, pulsed electric fields, oscillating magnetic fields or a combination of physical processes such as heat-irradiation, or heat-high hydrostatic pressure, etc. Each of the non-thermal technologies has specific applications in terms of the types of food that can be processed. Both conventional and newly developed physical treatments can be used in combination for controlling foodborne pathogens and enhancing the safety and shelf life of foods. Recent research has focused on combining traditional preservation factors with emerging intervention technologies. However, many key issues still need to be addressed for combination preservation factors or technologies to be useful in the food industry to meet public demands for foods with enhanced safety

  18. Thin-film fixed-bed reactor for solar photocatalytic inactivation of Aeromonas hydrophila: influence of water quality

    Directory of Open Access Journals (Sweden)

    Khan Sadia J

    2012-11-01

    Full Text Available Abstract Background Controlling fish disease is one of the major concerns in contemporary aquaculture. The use of antibiotics or chemical disinfection cannot provide a healthy aquaculture system without residual effects. Water quality is also important in determining the success or failure of fish production. Several solar photocatalytic reactors have been used to treat drinking water or waste water without leaving chemical residues. This study has investigated the impact of several key aspects of water quality on the inactivation of the pathogenic bacterium Aeromonas hydrophila using a pilot-scale thin-film fixed-bed reactor (TFFBR system. Results The level of inactivation of Aeromonas hydrophila ATCC 35654 was determined using a TFFBR with a photocatalytic area of 0.47 m2 under the influence of various water quality variables (pH, conductivity, turbidity and colour under high solar irradiance conditions (980–1100 W m-2, at a flow rate of 4.8 L h-1 through the reactor. Bacterial enumeration were obtained through conventional plate count using trypticase soy agar media, cultured in conventional aerobic conditions to detect healthy cells and under ROS-neutralised conditions to detect both healthy and sub-lethally injured (oxygen-sensitive cells. The results showed that turbidity has a major influence on solar photocatalytic inactivation of A. hydrophila. Humic acids appear to decrease TiO2 effectiveness under full sunlight and reduce microbial inactivation. pH in the range 7–9 and salinity both have no major effect on the extent of photoinactivation or sub-lethal injury. Conclusions This study demonstrates the effectiveness of the TFFBR in the inactivation of Aeromonas hydrophila under the influence of several water quality variables at high solar irradiance, providing an opportunity for the application of solar photocatalysis in aquaculture systems, as long as turbidity remains low.

  19. Viral pathogen discovery

    Science.gov (United States)

    Chiu, Charles Y

    2015-01-01

    Viral pathogen discovery is of critical importance to clinical microbiology, infectious diseases, and public health. Genomic approaches for pathogen discovery, including consensus polymerase chain reaction (PCR), microarrays, and unbiased next-generation sequencing (NGS), have the capacity to comprehensively identify novel microbes present in clinical samples. Although numerous challenges remain to be addressed, including the bioinformatics analysis and interpretation of large datasets, these technologies have been successful in rapidly identifying emerging outbreak threats, screening vaccines and other biological products for microbial contamination, and discovering novel viruses associated with both acute and chronic illnesses. Downstream studies such as genome assembly, epidemiologic screening, and a culture system or animal model of infection are necessary to establish an association of a candidate pathogen with disease. PMID:23725672

  20. Inactivation of Coxiella burnetti by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, G.H.; McCaul, T.F.; Williams, J.C.

    1989-01-01

    The gamma radiation inactivation kinetics for Coxiella burnetii at - 79 C were exponential. The radiation dose needed to reduce the number of infective C. burnetii by 90% varied from 0-64 to 1.2 kGy depending on the phase of hte micro-organism, purity of the culture and composition of suspending menstruum. The viability of preparations containing C. burnetti was completely abolished by 10 kGy without diminishing antigenicity or ability to elicit a protective immune response in vaccinated mice. Immunocytochemical examinations using monoclonal antibodies and electron microscopy demonstrated that radiation doses of 20 kGy did not alter cell-wall morphology or cell-surface antigenic epitopes.

  1. Inactivation of Coxiella burnetii by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, G.H.; McCaul, T.F. (Army Medical Research Inst. of Infectious Diseases, Fort Detrick, Frederick, MD (USA)); Williams, J.C. (National Inst. of Allergy and Infectious Diseases, Bethesda, MD (USA))

    1989-12-01

    The gamma radiation inactivation kinetics for Coxiella burnetii at - 79{sup 0}C were exponential. The radiation dose needed to reduce the number of infective C. burnetii by 90% varied from 0.64 to 1.2 kGy depending on the phase of the micro-organism, purity of the culture and composition of suspending menstruum. The viability of preparations containing 10{sup 11} C. burnetii ml{sup -1} was completely abolished by 10 kGy without diminishing antigenicity or ability to elicit a protective immune response in vaccinated mice. Immunocytochemical examinations using monoclonal antibodies and electron microscopy demonstrated that radiation doses of 20 kGy did not alter cell-wall morphology or cell-surface antigenic epitopes. (author).

  2. Inactivation of mitochondrial ATPase by ultraviolet light

    International Nuclear Information System (INIS)

    Chavez, E.; Cuellar, A.

    1984-01-01

    The present work describes experiments that show that far-ultraviolet irradiation induce the inhibition of ATPase activity in both membrane-bound and soluble F1. It was also found that ultraviolet light promotes the release of tightly bound adenine nucleotides from F1-ATPase. Experiments carried out with submitochondrial particles indicate that succinate partially protects against these effects of ultraviolet light. Titration of sulfhydryl groups in both irradiated submitochondrial particles and soluble F1-ATPase indicates that a conformational change induced by photochemical modifications of amino acid residues appears involved in the inactivation of the enzyme. Finally, experiments are described which show that the tyrosine residue located in the active site of F1-ATPase is modified by ultraviolet irradiation

  3. Inactivation of Coxiella burnetii by gamma irradiation

    International Nuclear Information System (INIS)

    Scott, G.H.; McCaul, T.F.; Williams, J.C.

    1989-01-01

    The gamma radiation inactivation kinetics for Coxiella burnetii at - 79 0 C were exponential. The radiation dose needed to reduce the number of infective C. burnetii by 90% varied from 0.64 to 1.2 kGy depending on the phase of the micro-organism, purity of the culture and composition of suspending menstruum. The viability of preparations containing 10 11 C. burnetii ml -1 was completely abolished by 10 kGy without diminishing antigenicity or ability to elicit a protective immune response in vaccinated mice. Immunocytochemical examinations using monoclonal antibodies and electron microscopy demonstrated that radiation doses of 20 kGy did not alter cell-wall morphology or cell-surface antigenic epitopes. (author)

  4. Esterase resistant to inactivation by heavy metals

    KAUST Repository

    El, Dorry Hamza

    2014-09-25

    EstATII is an esterase that a halotolerant, thermophilic and resistant to a spectrum of heavy metals including toxic concentration of metals. It was isolated from the lowest convective layer of the Atlantis II Red Sea brine pool. The Atlantis II brine pool is an extreme environment that possesses multiple harsh conditions such as; high temperature, salinity, pH and high concentration of metals, including toxic heavy metals. A fosmid metagenomic library using DNA isolated from the lowest convective layer this pool was used to identify EstATII. Polynucleotides encoding EstATII and similar esterases are disclosed and can be used to make EstATII. EstATII or compositions or apparatuses that contain it may be used in various processes employing lipases/esterases especially when these processes are performed under harsh conditions that inactivate other kinds of lipases or esterases.

  5. Polyphenol Oxidase Enzyme and Inactivation Methods

    Directory of Open Access Journals (Sweden)

    Leman Yılmaz

    2018-03-01

    Full Text Available Polyphenol oxidase enzyme is found in vegetables and fruits, as well as in some animal organs and microorganisms. Polyphenol oxidase enzyme responsible for enzymatic browning is a group of copper proteins that catalyses the oxidation of phenolic compounds to quinones, which produce brown pigments, commonly found in fruits and vegetables. During the industrial preparation of fruits and vegetables, results of catalytic effect of polyphenol oxidase causes enzymatic browning. Enzymatic browning impairs the appearance of products containing phenolic compounds along with undesirable colour, odor and taste formation and significant loss of nutritional value of the products. This affects the acceptability of the products by the consumers and causes economic losses. In this review, some characteristics of polyphenol oxidase enzyme in different fruits and vegetables have been reviewed and information about chemical antibrowning agents, thermal applications, irradiation applications and alternative methods such as high pressure processing, pulse electric field, supercritical carbon dioxide and ultrasound applications to inactivate this enzyme has been presented.

  6. Highly pathogenic avian influenza.

    Science.gov (United States)

    Swayne, D E; Suarez, D L

    2000-08-01

    Highly pathogenic (HP) avian influenza (AI) (HPAI) is an extremely contagious, multi-organ systemic disease of poultry leading to high mortality, and caused by some H5 and H7 subtypes of type A influenza virus, family Orthomyxoviridae. However, most AI virus strains are mildly pathogenic (MP) and produce either subclinical infections or respiratory and/or reproductive diseases in a variety of domestic and wild bird species. Highly pathogenic avian influenza is a List A disease of the Office International des Epizooties, while MPAI is neither a List A nor List B disease. Eighteen outbreaks of HPAI have been documented since the identification of AI virus as the cause of fowl plague in 1955. Mildly pathogenic avian influenza viruses are maintained in wild aquatic bird reservoirs, occasionally crossing over to domestic poultry and causing outbreaks of mild disease. Highly pathogenic avian influenza viruses do not have a recognised wild bird reservoir, but can occasionally be isolated from wild birds during outbreaks in domestic poultry. Highly pathogenic avian influenza viruses have been documented to arise from MPAI viruses through mutations in the haemagglutinin surface protein. Prevention of exposure to the virus and eradication are the accepted methods for dealing with HPAI. Control programmes, which imply allowing a low incidence of infection, are not an acceptable method for managing HPAI, but have been used during some outbreaks of MPAI. The components of a strategy to deal with MPAI or HPAI include surveillance and diagnosis, biosecurity, education, quarantine and depopulation. Vaccination has been used in some control and eradication programmes for AI.

  7. Effectiveness of standard UV depuration at inactivating Cryptosporidium parvum recovered from spiked Pacific oysters (Crassostrea gigas).

    Science.gov (United States)

    Sunnotel, O; Snelling, W J; McDonough, N; Browne, L; Moore, J E; Dooley, J S G; Lowery, C J

    2007-08-01

    When filter-feeding shellfish are consumed raw, because of their ability to concentrate and store waterborne pathogens, they are being increasingly associated with human gastroenteritis and have become recognized as important pathogen vectors. In the shellfish industry, UV depuration procedures are mandatory to reduce pathogen levels prior to human consumption. However, these guidelines are based around more susceptible fecal coliforms and Salmonella spp. and do not consider Cryptosporidium spp., which have significant resistance to environmental stresses. Thus, there is an urgent need to evaluate the efficiency of standard UV depuration against the survival of Cryptosporidium recovered from shellfish. Our study found that in industrial-scale shellfish depuration treatment tanks, standard UV treatment resulted in a 13-fold inactivation of recovered, viable C. parvum oocysts from spiked (1 x 10(6) oocysts liter (-1)) Pacific oysters. Depuration at half power also significantly reduced (P oysters. While UV treatment resulted in significant reductions of recovered viable oocysts, low numbers of viable oocysts were still recovered from oysters after depuration, making their consumption when raw a public health risk. Our study highlights the need for increased periodic monitoring programs for shellfish harvesting sites, improved depuration procedures, and revised microbial quality control parameters, including Cryptosporidium assessment, to minimize the risk of cryptosporidiosis.

  8. Inactivation of microorganisms in treated municipal wastewater and biosolids by gamma irradiation

    International Nuclear Information System (INIS)

    2009-01-01

    Increasing growth of the world's population, waste minimization policies and agricultural needs make the recycling of domestic wastewater quite a desirable practice. Factors like environmental and public health risks must be taken into account when considering treated wastewater for field irrigation and biosolids for land application. Pathogens present in wastewater and biosolids may remain active after treatment and there is always a great risk of transmission of infections via consuming crop and vegetables. Therefore it is very important to treat domestic wastewater properly before using it as an irrigation water and as a fertilizer. The work reported herein represents an evaluation of the variations in the population densities of below indicated pathogens monitored during a one year study in Ankara Central Municipal Wastewater Treatment Plant, and the efficiency of gamma irradiation for the inactivation of these important waterborne pathogens. Parasitological investigation Treated wastewater and biosolids - Cryptosporidium sp. - Giardia lamblia - Entamoeba histolytica - Cyclospora cayetanensis - Helminth ova Bacteriological investigation Treated wastewater - Total coliforms - Salmonella sp. - Fecal streptococci - Enterococcus sp. Biosolids - Fecal coliforms - Salmonella sp. (Includes 12 tables, 16 figures)

  9. Human pathogen avoidance adaptations

    NARCIS (Netherlands)

    Tybur, J.M.; Lieberman, D.

    2016-01-01

    Over the past few decades, researchers have become increasingly interested in the adaptations guiding the avoidance of disease-causing organisms. Here we discuss the latest developments in this area, including a recently developed information-processing model of the adaptations underlying pathogen

  10. Cationic antimicrobial peptides inactivate Shiga toxin-encoding bacteriophages

    Science.gov (United States)

    Del Cogliano, Manuel E.; Hollmann, Axel; Martinez, Melina; Semorile, Liliana; Ghiringhelli, Pablo D.; Maffía, Paulo C.; Bentancor, Leticia V.

    2017-12-01

    Shiga toxin (Stx) is the principal virulence factor during Shiga toxin-producing Escherichia coli (STEC) infections. We have previously reported the inactivation of bacteriophage encoding Stx after treatment with chitosan, a linear polysaccharide polymer with cationic properties. Cationic antimicrobial peptides (cAMPs) are short linear aminoacidic sequences, with a positive net charge, which display bactericidal or bacteriostatic activity against a wide range of bacterial species. They are promising novel antibiotics since they have shown bactericidal effects against multiresistant bacteria. To evaluate whether cationic properties are responsible for bacteriophage inactivation, we tested seven cationic peptides with proven antimicrobial activity as anti-bacteriophage agents, and one random sequence cationic peptide with no antimicrobial activity as a control. We observed bacteriophage inactivation after incubation with five cAMPs, but no inactivating activity was observed with the random sequence cationic peptide or with the non alpha helical cAMP Omiganan. Finally, to confirm peptide-bacteriophage interaction, zeta potential was analyzed by following changes on bacteriophage surface charges after peptide incubation. According to our results we could propose that: 1) direct interaction of peptides with phage is a necessary step for bacteriophage inactivation, 2) cationic properties are necessary but not sufficient for bacteriophage inactivation, and 3) inactivation by cationic peptides could be sequence (or structure) specific. Overall our data suggest that these peptides could be considered a new family of molecules potentially useful to decrease bacteriophage replication and Stx expression.

  11. Cationic Antimicrobial Peptides Inactivate Shiga Toxin-Encoding Bacteriophages

    Directory of Open Access Journals (Sweden)

    Manuel E. Del Cogliano

    2017-12-01

    Full Text Available Shiga toxin (Stx is the principal virulence factor during Shiga toxin-producing Escherichia coli (STEC infections. We have previously reported the inactivation of bacteriophage encoding Stx after treatment with chitosan, a linear polysaccharide polymer with cationic properties. Cationic antimicrobial peptides (cAMPs are short linear aminoacidic sequences, with a positive net charge, which display bactericidal or bacteriostatic activity against a wide range of bacterial species. They are promising novel antibiotics since they have shown bactericidal effects against multiresistant bacteria. To evaluate whether cationic properties are responsible for bacteriophage inactivation, we tested seven cationic peptides with proven antimicrobial activity as anti-bacteriophage agents, and one random sequence cationic peptide with no antimicrobial activity as a control. We observed bacteriophage inactivation after incubation with five cAMPs, but no inactivating activity was observed with the random sequence cationic peptide or with the non-alpha helical cAMP Omiganan. Finally, to confirm peptide-bacteriophage interaction, zeta potential was analyzed by following changes on bacteriophage surface charges after peptide incubation. According to our results we could propose that: (1 direct interaction of peptides with phage is a necessary step for bacteriophage inactivation, (2 cationic properties are necessary but not sufficient for bacteriophage inactivation, and (3 inactivation by cationic peptides could be sequence (or structure specific. Overall our data suggest that these peptides could be considered a new family of molecules potentially useful to decrease bacteriophage replication and Stx expression.

  12. Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium in powdered weaning food by electron-beam irradiation

    Science.gov (United States)

    Hong, Yun-Hee; Park, Ji-Yong; Park, Jong-Hyun; Chung, Myong-Soo; Kwon, Ki-Sung; Chung, Kyungsook; Won, Misun; Song, Kyung-Bin

    2008-09-01

    Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium were evaluated in powdered weaning food using electron-beam irradiation. E. sakazakii, B. cereus, and S. typhimurium were eliminated by irradiation at 16, 8, and 8 kGy, respectively. The D10-vlaues of E. sakazakii, B. cereus, and S. typhimurium inoculated on powdered weaning food were 4.83, 1.22, and 0.98 kGy, respectively. The results suggest that electron-beam irradiation should inhibit the growth of pathogenic bacteria on baby food without impairing qualities.

  13. Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium in powdered weaning food by electron-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Yun-Hee [Department of Food Science and Technology, College of Agriculture and Life Science, Chungnam National University, Yuseong-Gu, Daejeon 305-764 (Korea, Republic of); Park, Ji-Yong [Department of Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Park, Jong-Hyun [Department of Food Science and Biotechnology, Kyungwon University, Sungnam 461-701 (Korea, Republic of); Chung, Myong-Soo [Department of Food Science, Ehwa Women' s University, Seoul 120-750 (Korea, Republic of); Kwon, Ki-Sung [Center for Food safety Evaluation, Korea Food and Drug Administration, Seoul 122-704 (Korea, Republic of); Chung, Kyungsook; Won, Misun [Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333 (Korea, Republic of); Song, Kyung-Bin [Department of Food Science and Technology, College of Agriculture and Life Science, Chungnam National University, Yuseong-Gu, Daejeon 305-764 (Korea, Republic of)], E-mail: kbsong@cnu.ac.kr

    2008-09-15

    Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium were evaluated in powdered weaning food using electron-beam irradiation. E. sakazakii, B. cereus, and S. typhimurium were eliminated by irradiation at 16, 8, and 8 kGy, respectively. The D{sub 10}-vlaues of E. sakazakii, B. cereus, and S. typhimurium inoculated on powdered weaning food were 4.83, 1.22, and 0.98 kGy, respectively. The results suggest that electron-beam irradiation should inhibit the growth of pathogenic bacteria on baby food without impairing qualities.

  14. Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium in powdered weaning food by electron-beam irradiation

    International Nuclear Information System (INIS)

    Hong, Yun-Hee; Park, Ji-Yong; Park, Jong-Hyun; Chung, Myong-Soo; Kwon, Ki-Sung; Chung, Kyungsook; Won, Misun; Song, Kyung-Bin

    2008-01-01

    Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium were evaluated in powdered weaning food using electron-beam irradiation. E. sakazakii, B. cereus, and S. typhimurium were eliminated by irradiation at 16, 8, and 8 kGy, respectively. The D 10 -vlaues of E. sakazakii, B. cereus, and S. typhimurium inoculated on powdered weaning food were 4.83, 1.22, and 0.98 kGy, respectively. The results suggest that electron-beam irradiation should inhibit the growth of pathogenic bacteria on baby food without impairing qualities

  15. Inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree by high hydrostatic pressure with/without added ascorbic acid.

    Science.gov (United States)

    Mukhopadhyay, Sudarsan; Sokorai, Kimberly; Ukuku, Dike; Fan, Xuetong; Juneja, Vijay; Sites, Joseph; Cassidy, Jennifer

    2016-10-17

    The objective of this research was to evaluate and develop a method for inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree (CP) by high hydrostatic pressure (HHP). Cantaloupe being the most netted varieties of melons presents a greater risk of pathogen transmission. Freshly prepared CP with or without 0.1% ascorbic acid (AA) was inoculated with a bacterial cocktail composed of a three serotype mixture of S. enterica (S. Poona, S. Newport H1275 and S. Stanley H0558) and a mixture of three strains of L. monocytogenes (Scott A, 43256 and 51742) to a population of ca. 10(8)CFU/g. Double sealed and double bagged inoculated CP (ca. 5g) were pressure treated at 300, 400 and 500MPa at 8°C and 15°C for 5min. Data indicated increased inactivation of both Salmonella and Listeria spp. with higher pressure. Log reduction for CP at 300MPa, 8°C for 5min was 2.4±0.2 and 1.6±0.5logCFU/g for Salmonella and Listeria, respectively. Survivability of the pathogens was significantly compromised at 400MPa and 8°C, inactivating 4.5±0.3logCFU/g of Salmonella and 3.0±0.4logCFU/g of Listeria spp. Complete inactivation of the pathogens in the puree (log reduction >6.7logCFU/g), with or without AA, was achieved when the pressure was further increased to 500MPa, except that for Listeria containing no AA at 8°C. Listeria presented higher resistance to pressure treatment compared to Salmonella spp. Initial temperatures (8 and 15°C) had no significant influence on Salmonella log reductions. Log reduction of pathogens increased but not significantly with increase of temperature. AA did not show any significant antimicrobial activity. Viable counts were about 0.2-0.4logCFU/g less in presence of 0.1% AA. These data validate that HHP can be used as an effective method for decontamination of cantaloupe puree. Published by Elsevier B.V.

  16. Modified Carbapenem Inactivation Method for Phenotypic Detection of Carbapenemase Production among Enterobacteriaceae.

    Science.gov (United States)

    Pierce, Virginia M; Simner, Patricia J; Lonsway, David R; Roe-Carpenter, Darcie E; Johnson, J Kristie; Brasso, William B; Bobenchik, April M; Lockett, Zabrina C; Charnot-Katsikas, Angella; Ferraro, Mary Jane; Thomson, Richard B; Jenkins, Stephen G; Limbago, Brandi M; Das, Sanchita

    2017-08-01

    The ability of clinical microbiology laboratories to reliably detect carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) is an important element of the effort to prevent and contain the spread of these pathogens and an integral part of antimicrobial stewardship. All existing methods have limitations. A new, straightforward, inexpensive, and specific phenotypic method for the detection of carbapenemase production, the carbapenem inactivation method (CIM), was recently described. Here we describe a two-stage evaluation of a modified carbapenem inactivation method (mCIM), in which tryptic soy broth was substituted for water during the inactivation step and the length of this incubation was extended. A validation study was performed in a single clinical laboratory to determine the accuracy of the mCIM, followed by a nine-laboratory study to verify the reproducibility of these results and define the zone size cutoff that best discriminated between CP-CRE and members of the family Enterobacteriaceae that do not produce carbapenemases. Bacterial isolates previously characterized through whole-genome sequencing or targeted PCR as to the presence or absence of carbapenemase genes were tested for carbapenemase production using the mCIM; isolates with Ambler class A, B, and D carbapenemases, non-CP-CRE isolates, and carbapenem-susceptible isolates were included. The sensitivity of the mCIM observed in the validation study was 99% (95% confidence interval [95% CI], 93% to 100%), and the specificity was 100% (95% CI, 82% to 100%). In the second stage of the study, the range of sensitivities observed across nine laboratories was 93% to 100%, with a mean of 97%; the range of specificities was 97% to 100%, with a mean of 99%. The mCIM was easy to perform and interpret for Enterobacteriaceae , with results in less than 24 h and excellent reproducibility across laboratories. Copyright © 2017 American Society for Microbiology.

  17. Influence of virus strain and antigen mass on efficacy of H5 avian influenza inactivated vaccines.

    Science.gov (United States)

    Swayne, D E; Beck, J R; Garcia, M; Stone, H D

    1999-06-01

    The influence of vaccine strain and antigen mass on the ability of inactivated avian influenza (AI) viruses to protect chicks from a lethal, highly pathogenic (HP) AI virus challenge was studied. Groups of 4-week-old chickens were immunized with inactivated vaccines containing one of 10 haemagglutinin subtype H5 AI viruses, one heterologous H7 AI virus or normal allantoic fluid (sham), and challenged 3 weeks later by intra-nasal inoculation with a HP H5 chicken-origin AI virus. All 10 H5 vaccines provided good protection from clinical signs and death, and produced positive serological reactions on agar gel immunodiffusion and haemagglutination inhibition tests. In experiment 1, challenge virus was recovered from the oropharynx of 80% of chickens in the H5 vaccine group. In five H5 vaccine groups, challenge virus was not recovered from the cloaca of chickens. In the other five H5 vaccine groups, the number of chickens with detection of challenge virus from the cloaca was lower than in the sham group (P turkey/Wisconsin/68 (H5N9) was the best vaccine candidate of the H5 strains tested (PD50= 0.006 μg AI antigen). These data demonstrate that chickens vaccinated with inactivated H5 whole virus AI vaccines were protected from clinical signs and death, but usage of vaccine generally did not prevent infection by the challenge virus, as indicated by recovery of virus from the oropharynx. Vaccine use reduced cloacal detection rates, and quantity of virus shed from the cloaca and oropharynx in some vaccine groups, which would potentially reduce environmental contamination and disease transmission in the field.

  18. Lactobacilli inactivate Chlamydia trachomatis through lactic acid but not H2O2.

    Directory of Open Access Journals (Sweden)

    Zheng Gong

    Full Text Available Lactobacillus species dominate the microbiome in the lower genital tract of most reproductive-age women. Producing lactic acid and H2O2, lactobacilli are believed to play an important role in prevention of colonization by and growth of pathogens. However, to date, there have been no reported studies characterizing how lactobacilli interact with Chlamydia trachomatis, a leading sexually transmitted bacterium. In this report, we demonstrate inactivation of C. trachomatis infectivity by culture media conditioned by Lactobacillus crispatus, L. gasseri and L. jensenii, known to be dominating organisms in the human vaginal microbiome. Lactobacillus still cultures produced lactic acid, leading to time- and concentration-dependent killing of C. trachomatis. Neutralization of the acidic media completely reversed chlamydia killing. Addition of lactic acid into Lactobacillus-unconditioned growth medium recapitulated the chlamydiacidal activity of conditioned media. The H2O2 concentrations in the still cultures were found to be comparable to those reported for the cervicovaginal fluid, but insufficient to inactivate chlamydiae. Aeration of Lactobacillus cultures by shaking markedly induced H2O2 production, but strongly inhibited Lactobacillus growth and lactic acid production, and thus severely affected acidification, leading to significantly reduced chlamydiacidal efficiency. These observations indicate lactobacilli inactivate chlamydiae primarily through maintaining acidity in a relatively hypoxic environment in the vaginal lumen with limited H2O2, which is consistent with the notion that women with higher vaginal pH are more prone to sexually transmitted C. trachomatis infection. In addition to lactic acid, formic acid and acetic acid also exhibited potent chlamydiacidal activities. Taken together, our findings imply that lowering the vaginal pH through engineering of the vaginal microbiome and other means will make women less susceptible to C

  19. Luciferase inactivation in the luminous marine bacterium Vibrio harveyi.

    Science.gov (United States)

    Reeve, C A; Baldwin, T O

    1981-06-01

    Luciferase was rapidly inactivated in stationary-phase cultures of the wild type of the luminous marine bacterium Vibrio harveyi, but was stable in stationary-phase cultures of mutants of V. harveyi that are nonluminous without exogenous aldehyde, termed the aldehyde-deficient mutants. The inactivation in the wild type was halted by cell lysis and was slowed or stopped by O2 deprivation or by addition of KCN and NaF or of chloramphenicol. If KCN and NaF or chloramphenicol were added to a culture before the onset of luciferase inactivation, then luciferase inactivation did not occur. However, if these inhibitors were added after the onset of luciferase inactivation, then luciferase inactivation continued for about 2 to 3 h before the inactivation process stopped. The onset of luciferase inactivation in early stationary-phase cultures of wild-type cell coincided with a slight drop in the intracellular adenosine 5'-triphosphate (ATP) level from a relatively constant log-phase value of 20 pmol of ATP per microgram of soluble cell protein. Addition of KCN and NaF to a culture shortly after this drop in ATP caused a rapid decrease in the ATP level to about 4 pmol of ATP per microgram whereas chloramphenicol added at this same time caused a transient increase in ATP level to about 25 pmol/microgram. The aldehyde-deficient mutant (M17) showed a relatively constant log-phase ATP level identical with that of the wild-type cells, but rather than decreasing in early stationary phase, the ATP level increased to a value twice that in log-phase cells. We suggest that the inactivation of luciferase is dependent on the synthesis of some factor which is produced during stationary phase and is itself unstable, and whose synthesis is blocked by chloramphenicol or cyanide plus fluoride.

  20. Inactivation of viruses in municipal effluent by chlorine.

    OpenAIRE

    Hajenian, H. G.; Butler, M.

    1980-01-01

    The influence of pH and temperature on the efficiency of chlorine inactivation of two unrelated picornaviruses in a typical urban wastewater effluent was examined. Temperature, unlike pH, had relatively little effect on the rate of inactivation. The pH effect was complex and the two viruses differed. The f2 coliphage was more sensitive to chlorine at low pH, but at all values there was a threshold above which additional chlorine resulted in very rapid inactivation. The amount of chlorine requ...

  1. Inactivation of human and simian rotaviruses by ozone

    Energy Technology Data Exchange (ETDEWEB)

    Vaughn, J.M.; Chen, Y.S.; Lindburg, K.; Morales, D.

    1987-09-01

    The inactivation of simian rotavirus Sa-11 and human rotavirus type 2 (Wa) by ozone was compared at 4/sup 0/C by using single-particle virus stocks. Although the human strain was clearly more sensitive, both virus types were rapidly inactivated by ozone concentrations of 0.25 mg/liter or greater at all pH levels tested. Comparison of the virucidal activity of ozone with that of chlorine in identical experiments indicated little significant difference in rotavirus-inactivating efficiencies when the disinfectants were used at concentrations of 0.25 mg/liter or greater.

  2. Inactivation of rifampin by Nocardia brasiliensis.

    OpenAIRE

    Yazawa, K; Mikami, Y; Maeda, A; Akao, M; Morisaki, N; Iwasaki, S

    1993-01-01

    Rifampin was glycosylated by a pathogenic species of Nocardia, i.e., Nocardia brasiliensis. The structures of two glycosylated compounds (RIP-1 and RIP-2) isolated from the culture broth of the bacterium were determined to be 3-formyl-23-(O-[beta-D-glucopyranosyl])rifamycin SV and 23-(O-[beta-D-glucopyranosyl])rifampin, respectively. Both compounds lacked antimicrobial activity against other gram-positive bacteria as well as the Nocardia species.

  3. Method of inhibiting plant virus pathogen infections by crispr/cas9-mediated interference

    KAUST Repository

    Mahfouz, Magdy Mahmoud

    2016-11-24

    A genetically modified tobacco plant or tomato plant resistant to at least one pathogenic geminiviridae virus species is provided. The plant comprises a heterologous CRISPR/Cas9 system and at least one heterologous nucleotide sequence that is capable of hybridizing to a nucleotide sequence of the pathogenic virus and that directs inactivation of the pathogenic virus species or plurality of viral species by the CRISPR/Cas9 system. The heterologous nucleotide sequence can be complementary to, but not limited to an Intergenic Region (IR) of the Tomato Yellow Leaf Curl Virus (TYLCV), Further provided are methods of generating a genetically modified plant that is resistant to a virus pathogen by a heterologous CRISPR/Cas9 system and expression of a gRNA specifically targeting the virus.

  4. Settling and survival profile of enteric pathogens in the swine effluent for water reuse purpose.

    Science.gov (United States)

    Fongaro, G; Kunz, A; Magri, M E; Schissi, C D; Viancelli, A; Philippi, L S; Barardi, C R M

    2016-11-01

    The present study evaluated the pathogens persistence and settling profile in swine effluent. We determined the enteric pathogens settling characteristics, their survival and inactivation profile in swine effluent (for water reuse purpose) and in sludge (generated after aerobic treatment - during secondary settling process). The study was performed in laboratorial-scale and in full-scale (manure treatment plant). Enteric viruses and enteric bacteria were used as biomarkers. Results showed that these enteric pathogens were significantly reduced from swine effluent during secondary settling process, and enteric viruses removal was correlated with the suspended solids decantation. The design of secondary settlers can be adapted to improve pathogens removal, by diminishing the solids loading rate per area and time, ending in higher hydraulic retention times. Copyright © 2016 Elsevier GmbH. All rights reserved.

  5. Autophagy in plant pathogenic fungi.

    Science.gov (United States)

    Liu, Xiao-Hong; Xu, Fei; Snyder, John Hugh; Shi, Huan-Bin; Lu, Jian-Ping; Lin, Fu-Cheng

    2016-09-01

    Autophagy is a conserved cellular process that degrades cytoplasmic constituents in vacuoles. Plant pathogenic fungi develop special infection structures and/or secrete a range of enzymes to invade their plant hosts. It has been demonstrated that monitoring autophagy processes can be extremely useful in visualizing the sequence of events leading to pathogenicity of plant pathogenic fungi. In this review, we introduce the molecular mechanisms involved in autophagy. In addition, we explore the relationship between autophagy and pathogenicity in plant pathogenic fungi. Finally, we discuss the various experimental strategies available for use in the study of autophagy in plant pathogenic fungi. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Effects of pulsed electric fields on pathogenic microorganisms of major concern in fluid foods: a review.

    Science.gov (United States)

    Mosqueda-Melgar, Jonathan; Elez-Martínez, Pedro; Raybaudi-Massilia, Rosa M; Martín-Belloso, Olga

    2008-09-01

    Pathogenic microorganisms such as Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Yersinia enterocolitica, and Campylobacter jejuni have been implicated in foodborne diseases and outbreaks worldwide. These bacteria have been associated with the consumption of fresh fruit juices, milk, and dairy products, which are foodstuff, highly demanded by consumers in retails and supermarkets. Nowadays, consumers require high quality, fresh-like, and safe foods. Pulsed electric field (PEF) is a non-thermal preservation method, able to inactivate pathogenic microorganisms without significant loss of the organoleptic and nutritional properties of food. The PEF treatment effectiveness to destroy bacteria such as Listeria innocua, E. coli, Salmonella Typhimurium, E. coli O157:H7 and E. coli 8739 at pasteurization levels (> or = 5.0 log(10) cycles) in some fluid foods was reported. However, data on the inactivation of some microorganisms such as Bacillus cereus, Staphylococcus aureus, Yersinia enterocolitica, and Campylobacter jejuni in fluid foods by PEF processing is very limited. Therefore, future works should be focused toward the inactivation of these pathogenic bacteria in real foods.

  7. Application of slightly acidic electrolyzed water for inactivating microbes in a layer breeding house.

    Science.gov (United States)

    Hao, X X; Li, B M; Wang, C Y; Zhang, Q; Cao, W

    2013-10-01

    Lots of microorganisms exist in layer houses can cause bird diseases and worker health concerns. Spraying chemical disinfectants is an effective way to decontaminate pathogenic microorganisms in the air and on surfaces in poultry houses. Slightly acidic electrolyzed water (SAEW, pH 5.0-6.5) is an ideal, environmentally friendly broad-spectrum disinfectant to prevent and control bacterial or viral infection in layer farms. The purpose of this work was to investigate the cleaning effectiveness of SAEW for inactivating the microbes in layer houses. The effect of SAEW was evaluated by solid materials and surface disinfection in a hen house. Results indicate that SAEW with an available chlorine concentration of 250 mg/L, pH value of 6.19, and oxygen reduction potential of 974 mV inactivated 100% of bacteria and fungi in solid materials (dusts, feces, feather, and feed), which is more efficient than common chemical disinfectant such as benzalkonium chloride solution (1:1,000 vol/vol) and povidone-iodine solution (1:1,000 vol/vol). Also, it significantly reduced the microbes on the equipment or facility surfaces (P < 0.05), including floor, wall, feed trough, and water pipe surfaces. Moreover, SAEW effectively decreased the survival rates of Salmonella and Escherichia coli by 21 and 16 percentage points. In addition, spraying the target with tap water before disinfection plays an important role in spray disinfection.

  8. Combined Antimicrobial Activity of Photodynamic Inactivation and Antimicrobials–State of the Art

    Directory of Open Access Journals (Sweden)

    Agata Wozniak

    2018-05-01

    Full Text Available Antimicrobial photodynamic inactivation (aPDI is a promising tool for the eradication of life-threatening pathogens with different profiles of resistance. This study presents the state-of-the-art published studies that have been dedicated to analyzing the bactericidal effects of combining aPDI and routinely applied antibiotics in in vitro (using biofilm and planktonic cultures and in vivo experiments. Furthermore, the current paper reviews the methodology used to obtain the published data that describes the synergy between these antimicrobial approaches. The authors are convinced that even though the combined efficacy of aPDI and antimicrobials could be investigated with the wide range of methods, the use of a unified experimental methodology that is in agreement with antimicrobial susceptibility testing (AST is required to investigate possible synergistic cooperation between aPDI and antimicrobials. Conclusions concerning the possible synergistic activity between the two treatments can be drawn only when appropriate assays are employed. It must be noticed that some of the described papers were just aimed at determination if combined treatments exert enhanced antibacterial outcome, without following the standard methodology to evaluate the synergistic effect, but in most of them (18 out of 27 authors indicated the existence of synergy between described antibacterial approaches. In general, the increase in bacterial inactivation was observed when both therapies were used in combination.

  9. Batch solar disinfection inactivates oocysts of Cryptosporidium parvum and cysts of Giardia muris in drinking water.

    Science.gov (United States)

    McGuigan, K G; Méndez-Hermida, F; Castro-Hermida, J A; Ares-Mazás, E; Kehoe, S C; Boyle, M; Sichel, C; Fernández-Ibáñez, P; Meyer, B P; Ramalingham, S; Meyer, E A

    2006-08-01

    To determine whether batch solar disinfection (SODIS) can be used to inactivate oocysts of Cryptosporidium parvum and cysts of Giardia muris in experimentally contaminated water. Suspensions of oocysts and cysts were exposed to simulated global solar irradiation of 830 W m(-2) for different exposure times at a constant temperature of 40 degrees C. Infectivity tests were carried out using CD-1 suckling mice in the Cryptosporidium experiments and newly weaned CD-1 mice in the Giardia experiments. Exposure times of > or =10 h (total optical dose c. 30 kJ) rendered C. parvum oocysts noninfective. Giardia muris cysts were rendered completely noninfective within 4 h (total optical dose >12 kJ). Scanning electron microscopy and viability (4',6-diamidino-2-phenylindole/propidium iodide fluorogenic dyes and excystation) studies on oocysts of C. parvum suggest that inactivation is caused by damage to the oocyst wall. Results show that cysts of G. muris and oocysts of C. parvum are rendered completely noninfective after batch SODIS exposures of 4 and 10 h (respectively) and is also likely to be effective against waterborne cysts of Giardia lamblia. These results demonstrate that SODIS is an appropriate household water treatment technology for use as an emergency intervention in aftermath of natural or man-made disasters against not only bacterial but also protozoan pathogens.

  10. Inactivation kinetics of Escherichia coli O157:H7, Salmonella enterica Serovar Typhimurium, and Listeria monocytogenes in ready-to-eat sliced ham by near-infrared heating at different radiation intensities.

    Science.gov (United States)

    Ha, Jae-Won; Kang, Dong-Hyun

    2014-07-01

    The aim of this study was to investigate the inactivation kinetics of Salmonella enterica serovar Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes on ready-to-eat sliced ham by near-infrared (NIR) heating as a function of the processing parameter, radiation intensity. Precooked ham slices inoculated with the three pathogens were treated at different NIR intensities (ca. 100, 150, and 200 μW/cm(2)/nm). An increase in the applied radiation intensity resulted in a gradual increase of inactivation of all pathogens. The survival curves of the three pathogens exhibited both shoulder and tailing behavior at all light intensities. Among nonlinear models, the Weibull distribution and log-logistic model were used to describe the experimental data, and the statistical results (mean square error and R(2) values) indicated the suitability of the model for prediction. The log-logistic model more accurately described survival curves of the three pathogens than did the Weibull distribution at all radiation intensities. The output of this study and the proposed kinetics model would be beneficial to the deli meat industry for selecting the optimum processing conditions of NIR heating to meet the target pathogen inactivation on ready-to-eat sliced ham.

  11. Variations in the radiation sensitivity of foodborne pathogens associated with complex ready-to-eat food products

    Energy Technology Data Exchange (ETDEWEB)

    Sommers, Christopher H. [Food Safety Intervention Technologies Research Unit, Eastern Regional Research Center, Agricultural Research Service, US Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038 (United States)]. E-mail: csommers@errc.ars.usda.gov; Boyd, Glenn [Food Safety Intervention Technologies Research Unit, Eastern Regional Research Center, Agricultural Research Service, US Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038 (United States)

    2006-07-15

    Foodborne illness outbreaks and product recalls are occasionally associated with ready-to-eat (RTE) sandwiches and other 'heat and eat' multi-component RTE products. Ionizing radiation can inactivate foodborne pathogens on meat and poultry, fruits and vegetables, seafood, and RTE meat products. However, less data are available on the ability of low-dose ionizing radiation, doses under 5 kGy typically used for pasteurization purposes, to inactivate pathogenic bacteria on complex multi-component food products. In this study, the efficacy of ionizing radiation to inactivate Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, and Yersinia enterocolitica on RTE foods including a 'frankfurter on a roll', a 'beef cheeseburger on a bun' and a 'vegetarian cheeseburger on a bun' was investigated. The average D-10 values, the radiation dose needed to inactivate 1 log{sub 1} of pathogen, by bacterium species, were 0.61, 0.54, 0.47, 0.36 and 0.15 kGy for Salmonella spp., S. aureus, L. monocytogenes, E. coli O157:H7, and Y. enterocolitica, respectively when inoculated onto the three product types. These results indicate that irradiation may be an effective means for inactivating common foodborne pathogens including Salmonella spp, S. aureus, L. monocytogenes, E. coli O157:H7 and Y. enterocolitica in complex RTE food products such as 'heat and eat' sandwich products.

  12. Assessment of pathogen survival potential during managed aquifer recharge with diffusion chambers.

    Science.gov (United States)

    Sidhu, J P S; Toze, S

    2012-09-01

    To evaluate the efficacy of using in situ diffusion chambers for pathogen decay studies in the aquifer. A comparative microbial inactivation study was carried out in groundwater by seeding selected pathogens and indicators in laboratory microcosms and Teflon diffusion chambers (in situ) fitted with 0.010- and 0.025-μm pore-size membranes. The results have shown that there is a difference in the decay rates obtained from the laboratory microcosms and in situ diffusion chambers for several pathogens. The results suggest that the use of laboratory microcosms to determine pathogen decay during the Managed Aquifer Recharge (MAR) may lead to underestimation of decay of adenovirus and Cryptosporidium and subsequent inaccurate assessment of the required residence time in the aquifer for pathogens to be removed from the recharged water. The decay rate of two indicator bacteria, Salmonella enterica and adenovirus, was found to be significantly slower (t-test, P aquifers. Reliable assessment of potential public health risks from the presence of pathogens in groundwater is essential for proper management of the MAR schemes. The results of this study suggest that in situ assessment of pathogen survival potential in diffusion chambers provided more reliable data for pathogen risk assessment and subsequent risk mitigation plans for MAR schemes. © 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  13. Comparison of two different methods for inactivation of viruses in serum

    DEFF Research Database (Denmark)

    Preuss, T.; Kamstrup, Søren; Kyvsgaard, N.C.

    1997-01-01

    enterovirus (PEV) was inactivated within 3 h, The inactivation with electron-beam irradiation resulted in almost linear curves in a semilogarithmic plot of virus titer versus irradiation dose, reflecting a first-order inactivation, The rate of inactivation was almost twice as fast in the liquid samples...

  14. CHLORINE INACTIVATION OF CATEGORY "A" BIO-TERRORISM AGENTS

    Science.gov (United States)

    This poster presents information on the inactivation of select bioterrorist agents. Information will be presented on chlorine disinfection of vegetative cells of Brucella suis, Brucella melitensis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis and endos...

  15. Inactivation of rabies diagnostic reagents by gamma radiation

    International Nuclear Information System (INIS)

    Gamble, W.C.; Chappell, W.A.; George, E.H.

    1980-01-01

    Treatment of CVS-11 rabies adsorbing suspensions and street rabies infected mouse brains with gamma radiation resulted in inactivated reagents that are safer to distribute and use. These irradiated reagents were as sensitive and reactive as the nonirradiated control reagents

  16. Use of genetic algorithms for high hydrostatic pressure inactivation ...

    African Journals Online (AJOL)

    ) for high hydrostatic pressure (HHP) inactivation of Bacillus cereus spores, Bacillus subtilis spores and cells, Staphylococcus aureus and Listeria monocytogenes, all in milk buffer, were used to demonstrate the utility of genetic algorithms ...

  17. Inactivation of bacterial cells by cyclotron beams

    Energy Technology Data Exchange (ETDEWEB)

    Yatagai, F [Waseda Univ., Tokyo (Japan). School of Science and Engineering; Takahashi, T; Matsuyama, A

    1975-06-01

    B. subtilis spores, E. coli Bsub(s-1) and E. coli B/r were bombarded with ..cap alpha..-particles and heavy ions of carbon, nitrogen and oxygen accelerated in the IPCR Cyclotron. The RBE versus LETsub(infinity) curve for B. subtilis spores showed a maximum peak at 120 keV/..mu..m, while those for E. coli Bsub(s-1) and E. coli B/r declined without any maximum as LETsub(infinity) values increased. In the region of ..cap alpha..-particles, the effective inactivation cross section (Ssub(eff)) for these three strains increased with increasing LETsub(infinity), and the rates of increase in Ssub(eff) in the LET region from --30 to --150 keV/..mu..m were 15.0, 1.5 and 2.5 times for B. subtilis spores, E. coli Bsub(s-1) and E. coli B/r, respectively. In the case of B. subtilis spores, Ssub(eff) values for heavy ions were almost independent of their energies, but the other two strains showed a considerable dependence upon beam energy. The characteristic LET dependence of Ssub(eff) observed in this study was fairly well explained by the target theory based on microdose concept.

  18. Inactivation of RNA viruses by gamma irradiation

    International Nuclear Information System (INIS)

    Nonomiya, Takashi; Morimoto, Akinori; Iwatsuki, Kazuo; Tsutsumi, Takamasa; Ito, Hitoshi; Yamashiro, Tomio; Ishigaki, Isao.

    1992-01-01

    Four kinds of RNA viruses, Bluetongue virus (BT), Bovine Virus Diarrhea-Mucosal Disease virus (BVD·MD), Bovine Respiratory Syncytial virus (RS), Vesicular Stmatitis virus (VS), were subjected to various doses of gamma irradiation to determine the lethal doses. The D 10 values, which are the dose necessary to decimally reduce infectivity, ranged from 1.5 to 3.4 kGy under frozen condition at dry-ice temperature, and they increased to 2.6 to 5.0 kGy under frozen condition at dry-ice temperature. Serum neutralzing antibody titer of Infectious Bovine Rhinotracheitis (IBR) was not adversely changed by the exposure to 36 kGy of gamma-rays under frozen condition. Analysis of electrophoresis patterns of the bovine serum also reveales that the serum proteins were not remarkably affected, even when exposed to 36 kGy of gamma radiation under frozen condition. The results suggested that gamma irradiation under frozen condition is an effective means for inactivating both DNA and RNA viruses without adversely affecting serum proteins and neutralizing antibody titer. (author)

  19. Inactivation of RNA viruses by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nonomiya, Takashi; Morimoto, Akinori; Iwatsuki, Kazuo; Tsutsumi, Takamasa (Ministry of Agriculture, Forestry and fisheries, Yokohama, Kanagawa (Japan). Animal Quarantine Service); Ito, Hitoshi; Yamashiro, Tomio; Ishigaki, Isao

    1992-09-01

    Four kinds of RNA viruses, Bluetongue virus (BT), Bovine Virus Diarrhea-Mucosal Disease virus (BVD[center dot]MD), Bovine Respiratory Syncytial virus (RS), Vesicular Stmatitis virus (VS), were subjected to various doses of gamma irradiation to determine the lethal doses. The D[sub 10] values, which are the dose necessary to decimally reduce infectivity, ranged from 1.5 to 3.4 kGy under frozen condition at dry-ice temperature, and they increased to 2.6 to 5.0 kGy under frozen condition at dry-ice temperature. Serum neutralzing antibody titer of Infectious Bovine Rhinotracheitis (IBR) was not adversely changed by the exposure to 36 kGy of gamma-rays under frozen condition. Analysis of electrophoresis patterns of the bovine serum also reveales that the serum proteins were not remarkably affected, even when exposed to 36 kGy of gamma radiation under frozen condition. The results suggested that gamma irradiation under frozen condition is an effective means for inactivating both DNA and RNA viruses without adversely affecting serum proteins and neutralizing antibody titer. (author).

  20. Inactivation of bacterial cells by cyclotron beams

    International Nuclear Information System (INIS)

    Yatagai, Fumio; Takahashi, Tadashi; Matsuyama, Akira.

    1975-01-01

    B. subtilis spores, E. coli Bsub(s-1) and E. coli B/r were bombarded with α-particles and heavy ions of carbon, nitrogen and oxygen accelerated in the IPCR Cyclotron. The RBE versus LETsub(infinity) curve for B. subtilis spores showed a maximum peak at 120 keV/μm, while those for E. coli Bsub(s-1) and E. coli B/r declined without any maximum as LETsub(infinity) values increased. In the region of α-particles, the effective inactivation cross section (Ssub(eff)) for these three strains increased with increasing LETsub(infinity), and the rates of increase in Ssub(eff) in the LET region from --30 to --150 keV/μm were 15.0, 1.5 and 2.5 times for B. subtilis spores, E. coli Bsub(s-1) and E. coli B/r, respectively. In the case of B. subtilis spores, Ssub(eff) values for heavy ions were almost independent of their energies, but the other two strains showed a considerable dependence upon beam energy. The characteristic LET dependence of Ssub(eff) observed in this study was fairly well explained by the target theory based on microdose concept. (auth.)

  1. Dry-heat inactivation of "Mycobacterium canettii".

    Science.gov (United States)

    Aboubaker Osman, Djaltou; Garnotel, Eric; Drancourt, Michel

    2017-06-09

    "Mycobacterium canettii" is responsible for non-transmissible lymph node and pulmonary tuberculosis in persons exposed in the Horn of Africa. In the absence of direct human transmission, contaminated water and foodstuffs could be sources of contamination. We investigated the dry-heat inactivation of "M. canettii" alone and mixed into mock-infected foodstuffs by inoculating agar cylinders and milk with 10 4 colony-forming units of "M. canettii" CIPT140010059 and two "M. canettii" clinical strains with Mycobacterium tuberculosis H37Rv as a control. Exposed to 35 °C, M. tuberculosis H37Rv, "M canettii" CIPT140010059 and "M. canettii" 157 exhibited a survival rate of 108, 95 and 81%, which is significantly higher than that of "M. canettii" 173. However, all tested mycobacteria tolerated a 90-min exposure at 45 °C. In the foodstuff models set at 70 °C, no growing mycobacteria were visualized. This study supports the premise that "M. canettii" may survive up to 45 °C; and suggests that contaminated raw drinks and foodstuffs but not cooked ones may be sources of infection for populations.

  2. Evolution of microbial pathogens.

    OpenAIRE

    Morschhäuser, J; Köhler, G; Ziebuhr, W; Blum-Oehler, G; Dobrindt, U; Hacker, J

    2000-01-01

    Various genetic mechanisms including point mutations, genetic rearrangements and lateral gene transfer processes contribute to the evolution of microbes. Long-term processes leading to the development of new species or subspecies are termed macroevolution, and short-term developments, which occur during days or weeks, are considered as microevolution. Both processes, macro- and microevolution need horizontal gene transfer, which is particularly important for the development of pathogenic micr...

  3. Lactobacillus acidophilus ameliorates H. pylori-induced gastric inflammation by inactivating the Smad7 and NFκB pathways

    Directory of Open Access Journals (Sweden)

    Yang Yao-Jong

    2012-03-01

    Full Text Available Abstract Background H. pylori infection may trigger Smad7 and NFκB expression in the stomach, whereas probiotics promote gastrointestinal health and improve intestinal inflammation caused by pathogens. This study examines if probiotics can improve H. pylori-induced gastric inflammation by inactivating the Smad7 and NFκB pathways. Results Challenge with H. pylori increased IL-8 and TNF-α expressions but not TGF-β1 in MKN45 cells. The RNA levels of Smad7 in AGS cells increased after H. pylori infection in a dose-dependent manner. A higher dose (MOI 100 of L. acidophilus pre-treatment attenuated the H. pylori-induced IL-8 expressions, but not TGF-β1. Such anti-inflammatory effect was mediated via increased cytoplasmic IκBα and depletion of nuclear NFκB. L. acidophilus also inhibited H. pylori-induced Smad7 transcription by inactivating the Jak1 and Stat1 pathways, which might activate the TGF-β1/Smad pathway. L. acidophilus pre-treatment ameliorated IFN-γ-induced Smad7 translation level and subsequently reduced nuclear NF-κB production, as detected by western blotting. Conclusions H. pylori infection induces Smad7, NFκB, IL-8, and TNF-α production in vitro. Higher doses of L. acidophilus pre-treatment reduce H. pylori-induced inflammation through the inactivation of the Smad7 and NFκB pathways.

  4. High pressure inactivation of Brettanomyces bruxellensis in red wine.

    Science.gov (United States)

    van Wyk, Sanelle; Silva, Filipa V M

    2017-05-01

    Brettanomyces bruxellensis ("Brett") is a major spoilage concern for the wine industry worldwide, leading to undesirable sensory properties. Sulphur dioxide, is currently the preferred method for wine preservation. However, due to its negative effects on consumers, the use of new alternative non-thermal technologies are increasingly being investigated. The aim of this study was to determine and model the effect of high pressure processing (HPP) conditions and yeast strain on the inactivation of "Brett" in Cabernet Sauvignon wine. Processing at 200 MPa for 3 min resulted in 5.8 log reductions. However higher pressure is recommended to achieve high throughput in the wine industry, for example >6.0 log reductions were achieved after 400 MPa for 5 s. The inactivation of B. bruxellensis is pressure and time dependent, with increased treatment time and pressure leading to increased yeast inactivation. It was also found that yeast strain had a significant effect on HPP inactivation, with AWRI 1499 being the most resistant strain. The Weibull model successfully described the HPP "Brett" inactivation. HPP is a viable alternative for the inactivation of B. bruxellensis in wine, with the potential to reduce the industry's reliance on sulphur dioxide. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Thermal inactivation kinetics of β-galactosidase during bread baking.

    Science.gov (United States)

    Zhang, Lu; Chen, Xiao Dong; Boom, Remko M; Schutyser, Maarten A I

    2017-06-15

    In this study, β-galactosidase was utilized as a model enzyme to investigate the mechanism of enzyme inactivation during bread baking. Thermal inactivation of β-galactosidase was investigated in a wheat flour/water system at varying temperature-moisture content combinations, and in bread during baking at 175 or 205°C. In the wheat flour/water system, the thermostability of β-galactosidase increased with decreased moisture content, and a kinetic model was accurately fitted to the corresponding inactivation data (R 2 =0.99). Interestingly, the residual enzyme activity in the bread crust (about 30%) was hundredfold higher than that in the crumb (about 0.3%) after baking, despite the higher temperature in the crust throughout baking. This result suggested that the reduced moisture content in the crust increased the thermostability of the enzyme. Subsequently, the kinetic model reasonably predicted the enzyme inactivation in the crumb using the same parameters derived from the wheat flour/water system. However, the model predicted a lower residual enzyme activity in the crust compared with the experimental result, which indicated that the structure of the crust may influence the enzyme inactivation mechanism during baking. The results reported can provide a quantitative understanding of the thermal inactivation kinetics of enzyme during baking, which is essential to better retain enzymatic activity in bakery products supplemented with heat-sensitive enzymes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Photodynamic inactivation of foodborne bacteria by eosin Y.

    Science.gov (United States)

    Bonin, E; Dos Santos, A R; Fiori da Silva, A; Ribeiro, L H; Favero, M E; Campanerut-Sá, P A Z; de Freitas, C F; Caetano, W; Hioka, N; Mikcha, J M G

    2018-03-25

    The aim of this study was evaluate the effect of photodynamic inactivation mediated by eosin Y in Salmonella enterica serotype Typhimurium ATCC 14028, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Bacillus cereus ATCC 11778. Bacteria (10 7 CFU per ml) were incubated with eosin Y at concentrations ranging from 0·1 to 10 μmol l -1 , irradiated by green LED (λ max 490-570 nm) for 5, 10 and 15 min and the cellular viability was determined. Pseudomonas aeruginosa was completely inactivated when treated with 10 μmol l -1 eosin Y for 10 min. Treatments reduced B. cereus and Salm. Typhimurium counts to 2·7 log CFU per ml and 1·7 log CFU per ml, respectively. Escherichia coli counts were slightly reduced. Staphylococcus aureus presented the highest sensitivity, being completely inactivated by eosin Y at 5 μmol l -1 and 5 min of illumination. The reduction of cellular viability of photoinactivated Staph. aureus was also demonstrated by flow cytometry and morphological changes were observed by scanning electron microscopy. Eosin Y in combination with LED produced bacterial inactivation, being a potential candidate for photodynamic inactivation. This study evidenced the efficacy of photodynamic inactivation as a novel and promising alternative to bacterial control. © 2018 The Society for Applied Microbiology.

  7. Differential Expression Analysis by RNA-Seq Reveals Perturbations in the Platelet mRNA Transcriptome Triggered by Pathogen Reduction Systems

    OpenAIRE

    Osman, Abdimajid; Hitzler, Walter E.; Ameur, Adam; Provost, Patrick

    2015-01-01

    Platelet concentrates (PCs) are prepared at blood banks for transfusion to patients in certain clinical conditions associated with a low platelet count. To prevent transfusion-transmitted infections via PCs, different pathogen reduction (PR) systems have been developed that inactivate the nucleic acids of contaminating pathogens by chemical cross-linking, a mechanism that may also affect platelets' nucleic acids. We previously reported that treatment of stored platelets with the PR system Int...

  8. Inactivation of an enterovirus by airborne disinfectants

    Science.gov (United States)

    2013-01-01

    Background The activity of airborne disinfectants on bacteria, fungi and spores has been reported. However, the issue of the virucidal effect of disinfectants spread by fogging has not been studied thoroughly. Methods A procedure has been developed to determine the virucidal activity of peracetic acid-based airborne disinfectants on a resistant non-enveloped virus poliovirus type 1. This virus was laid on a stainless carrier. The products were spread into the room by hot fogging at 55°C for 30 minutes at a concentration of 7.5 mL.m-3. Poliovirus inoculum, supplemented with 5%, heat inactivated non fat dry organic milk, were applied into the middle of the stainless steel disc and were dried under the air flow of a class II biological safety cabinet at room temperature. The Viral preparations were recovered by using flocked swabs and were titered on Vero cells using the classical Spearman-Kärber CPE reading method, the results were expressed as TCID50.ml-1. Results The infectious titer of dried poliovirus inocula was kept at 105 TCID50.mL-1 up to 150 minutes at room temperature. Dried inocula exposed to airborne peracetic acid containing disinfectants were recovered at 60 and 120 minutes post-exposition and suspended in culture medium again. The cytotoxicity of disinfectant containing medium was eliminated through gel filtration columns. A 4 log reduction of infectious titer of dried poliovirus inocula exposed to peracetic-based airborne disinfectant was obtained. Conclusion This study demonstrates that the virucidal activity of airborne disinfectants can be tested on dried poliovirus. PMID:23587047

  9. Antimicrobial blue light inactivation of Neisseria gonorrhoeae

    Science.gov (United States)

    Wang, Ying; Gu, Ying; Dai, Tianhong

    2018-02-01

    Neisseria gonorrhoeae is a human-adapted, gram-negative diplococcus that infects human reproductive tracts and causes gonorrhea, a sexually transmitted disease, resulting in discharge and inflammation at the urethra, cervix, pharynx, or rectum. Over the years, N. gonorrhoeae has developed resistance to nearly every drug ever used to treat it, including sulfonamides, penicillin, tetracycline, and fluoroquinolones. Drug-resistant N. gonorrhoeae is now considered by the Centers for Disease Control and Prevention (CDC) as an urgent threat. The present study aimed to evaluate the efficacy of antimicrobial blue light (aBL) at 405 and 470 nm for inactivating N. gonorrhoeae and reveal the mechanism of action. Our results showed that an exposure of 45 J/cm2 aBL at 405 nm reduced the bacterial CFU by 7.16-log10. When the aBL exposure was increased to 54 J/cm2, eradication of bacterial CFU was achieved. When the bacteria were exposed to aBL at 470 nm, 3-log10 reduction of CFU was observed at an aBL exposure of higher than 126 J/cm2. Absorption and fluorescence spectroscopic analyses revealed the presence of endogenous porphyrins and flavins in N. gonorrhoeae cells. The present study indicated that aBL is a potential strategy to control N. gonorrhoeae infections. Endogenous porphyrins play a vital role in the killing effects of aBL. In vivo experiments are ongoing in our laboratory to treat genital tract infections in mice using aBL and explore the potential clinical applications.

  10. Inactivation of Bacteria S. aureus ATCC 25923 and S. Thyphimurium ATCC 14 028 Influence of UV-HPEF

    Science.gov (United States)

    Bakri, A.; Hariono, B.; Utami, M. M. D.; Sutrisno

    2018-01-01

    The research was objected to study the performance of the UV unit - HPEF in inactivating bacteria population of Gram-positive (S aureus ATCC 25923) and Gram-negative (S Thyphimurium ATCC 14028) inoculated in sterilized goat’s milk. UV pasteurization instrument employed three reactors constructed in series UV-C system at 10 W, 253.7 nm wavelength made in Kada (USA) Inc. with 1.8 J/cm2 dose per reactor. HPEF instrument used high pulsed electric field at 31.67 kV/cm, 15 Hz and goat’s milk rate at 4:32 ± 0.71 cc/second. Pathogenic bacteria was observed According to Indonesian National Standard 01-2782-1998. Inactivation rate of pathogenic bacteria ie S Thyphimurium ATCC 14028 and S. aureus ATCC 25923 was 0.28 and 0.19 log cycle or 6.35 and 4.34 log cfu/ml/hour, respectively; D value was 0.16 and 0.23 hour with k value was 14.62 and 10 hour-1 respectively.

  11. Effects of irradiation and fumaric acid treatment on the inactivation of Listeria monocytogenes and Salmonella typhimurium inoculated on sliced ham

    International Nuclear Information System (INIS)

    Song, Hyeon-Jeong; Lee, Ji-Hye; Song, Kyung Bin

    2011-01-01

    To examine the effects of fumaric acid and electron beam irradiation on the inactivation of foodborne pathogens in ready-to-eat meat products, sliced ham was inoculated with Listeria monocytogenes and Salmonella typhimurium. The inoculated ham slices were treated with 0.5% fumaric acid or electron beam irradiation at 2 kGy. Fumaric acid treatment reduced the populations of L. monocytogenes and S. typhimurium by approximately 1 log CFU/g compared to control populations. In contrast, electron beam irradiation decreased the populations of S. typhimurium and L. monocytogenes by 3.78 and 2.42 log CFU/g, respectively. These results suggest that electron beam irradiation is a better and appropriate technique for improving the microbial safety of sliced ham. - Highlights: → We compare irradiation and fumaric acid treatment on the inactivation of pathogens. → We examine changes in the populations of L. monocytogenes and S. typhimurium. → Irradiation at 2 kGy is more effective in sliced ham than fumaric acid treatment. → Low-dose irradiation can improve the microbial safety of sliced ham during storage.

  12. Effects of irradiation and fumaric acid treatment on the inactivation of Listeria monocytogenes and Salmonella typhimurium inoculated on sliced ham

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hyeon-Jeong; Lee, Ji-Hye [Department of Food Science and Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Song, Kyung Bin, E-mail: kbsong@cnu.ac.kr [Department of Food Science and Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2011-11-15

    To examine the effects of fumaric acid and electron beam irradiation on the inactivation of foodborne pathogens in ready-to-eat meat products, sliced ham was inoculated with Listeria monocytogenes and Salmonella typhimurium. The inoculated ham slices were treated with 0.5% fumaric acid or electron beam irradiation at 2 kGy. Fumaric acid treatment reduced the populations of L. monocytogenes and S. typhimurium by approximately 1 log CFU/g compared to control populations. In contrast, electron beam irradiation decreased the populations of S. typhimurium and L. monocytogenes by 3.78 and 2.42 log CFU/g, respectively. These results suggest that electron beam irradiation is a better and appropriate technique for improving the microbial safety of sliced ham. - Highlights: > We compare irradiation and fumaric acid treatment on the inactivation of pathogens. > We examine changes in the populations of L. monocytogenes and S. typhimurium. > Irradiation at 2 kGy is more effective in sliced ham than fumaric acid treatment. > Low-dose irradiation can improve the microbial safety of sliced ham during storage.

  13. Arabidopsis wat1 (walls are thin1)-mediated resistance to the bacterial vascular pathogen, Ralstonia solanacearum, is accompanied by cross-regulation of salicylic acid and tryptophan metabolism

    NARCIS (Netherlands)

    Denancé, N.; Ranocha, P.; Oria, N.; Barlet, X.; Rivière, M.P.; Yadeta, K.A.; Hoffmann, L.; Perreau, F.; Clément, G.; Maia-Grondard, A.; Berg, van den G.C.M.; Savelli, B.; Fournier, S.; Aubert, Y.; Pelletier, S.; Thomma, B.P.H.J.; Molina, A.; Jouanin, L.; Marco, Y.; Goffner, D.

    2013-01-01

    Inactivation of Arabidopsis WAT1 (Walls Are Thin1), a gene required for secondary cell-wall deposition, conferred broad-spectrum resistance to vascular pathogens, including the bacteria Ralstonia solanacearum and Xanthomonas campestris pv. campestris, and the fungi Verticillium dahliae and

  14. Characterization of Immune Responses to an Inactivated Avian Influenza Virus Vaccine Adjuvanted with Nanoparticles Containing CpG ODN.

    Science.gov (United States)

    Singh, Shirene M; Alkie, Tamiru N; Abdelaziz, Khaled Taha; Hodgins, Douglas C; Novy, Anastasia; Nagy, Éva; Sharif, Shayan

    2016-06-01

    Avian influenza virus (AIV), a mucosal pathogen, gains entry into host chickens through respiratory and gastrointestinal routes. Most commercial AIV vaccines for poultry consist of inactivated, whole virus with adjuvant, delivered by parenteral administration. Recent advances in vaccine development have led to the application of nanoparticle emulsion delivery systems, such as poly (d,l-lactic-co-glycolic acid) (PLGA) nanoparticles to enhance antigen-specific immune responses. In chickens, the Toll-like receptor 21 ligand, CpG oligodeoxynucleotides (ODNs), have been demonstrated to be immunostimulatory. The objective of this study was to compare the adjuvant potential of CpG ODN 2007 encapsulated in PLGA nanoparticles with nonencapsulated CpG ODN 2007 when combined with a formalin-inactivated H9N2 virus, through intramuscular and aerosol delivery routes. Chickens were vaccinated at days 7 and 21 posthatch for the intramuscular route and at days 7, 21, and 35 for the aerosol route. Antibody-mediated responses were evaluated weekly in sera and lacrimal secretions in specific pathogen-free chickens. The results indicate that nonencapsulated CpG ODN 2007 in inactivated AIV vaccines administered by the intramuscular route generated higher antibody responses compared to the encapsulated CpG ODN 2007 formulation by the same route. Additionally, encapsulated CpG ODN 2007 in AIV vaccines administered by the aerosol route elicited higher mucosal responses compared to nonencapsulated CpG ODN 2007. Future studies may be aimed at evaluating protective immune responses induced with PLGA encapsulation of AIV and adjuvants.

  15. Effect of post-treatment conditions on the inactivation of helminth eggs (Ascaris suum) after the composting process.

    Science.gov (United States)

    Darimani, Hamidatu S; Ito, Ryusei; Maiga, Ynoussa; Sou, Mariam; Funamizu, Naoyuki; Maiga, Amadou H

    2016-01-01

    Safe and appropriate disposal of human waste is a basic requirement for sanitation and protection of public health. For proper sanitation and nutrient recovery, it is necessary to ensure effective treatment methods to complete pathogen destruction in excreta prior to reuse. Composting toilets convert faeces to a reusable resource such as fertilizer or humus for organic agriculture. A composting toilet for rural Burkina Faso was created by modifying a commercial model available in Japan to improve hygiene and increase food production. The toilet has shown to result in a degraded final product, but its effectiveness for pathogen destruction was unclear due to low temperatures generated from the toilet. This study aimed to sanitize compost withdrawn from the composting toilet for food production by setting post-treatment conditions. The inactivation kinetics of Ascaris suum eggs, selected as an indicator for helminth eggs, was determined during post-treatment at different temperatures (30°C, 40°C, 50°C and 60°C) with varying moisture contents (MC) (50%, 60% and 70%). The treatment of compost in a possible additional post-treatment after the composting process was tried in the laboratory test. Inactivation of A. suum eggs was fast with greater than two log reductions achieved within 2 h for temperature 50°C and 50% MC and greater than three log reductions for temperature 60°C and 50% MC within 3 h. Statistical analysis showed the significant impact of temperature and moisture on the inactivation rates of A. suum eggs. The post-treatment can efficiently increase helminth eggs destruction prior to reuse.

  16. Modelling Yersinia enterocolitica inactivation in coculture experiments with Lactobacillus sakei as based on pH and lactic acid profiles.

    Science.gov (United States)

    Janssen, M; Geeraerd, A H; Logist, F; De Visscher, Y; Vereecken, K M; Debevere, J; Devlieghere, F; Van Impe, J F

    2006-08-15

    In food processing and preservation technology, models describing microbial proliferation in food products are a helpful tool to predict the microbial food safety and shelf life. In general, the available models consider microorganisms in pure culture. Thus, microbial interactions are ignored, which may lead to a discrepancy between model predictions and the actual microbial evolution, particularly for fermented and minimally processed food products in which a background flora is often present. In this study, the lactic acid mediated negative microbial interaction between the lactic acid bacterium Lactobacillus sakei and the psychrotrophic food pathogen Yersinia enterocolitica was examined. A model describing the lactic acid induced inhibition (i.e., early induction of the stationary phase) of the pathogen [Vereecken, K.M., Devlieghere, F., Bockstaele, A., Debevere, J., Van Impe, J.F., 2003. A model for lactic acid induced inhibition of Yersinia enterocolitica in mono- and coculture with Lactobacillus sakei. Food Microbiology 20, 701-713.] was extended to describe the subsequent inactivation (i.e., decrease of the cell concentration to values below the detection limit). In the development of a suitable model structure to describe the inactivation process, critical points in the variation of the specific evolution rate mu [1/h] with the dynamic (time-varying) pH and undissociated lactic acid profiles were taken into account. Thus, biological knowledge, namely, both pH and undissociated lactic acid have an influence on the microbial evolution, was incorporated. The extended model was carefully validated on new data. As a result, the newly developed model is able to accurately predict the growth, inhibition and subsequent inactivation of Y. enterocolitica in coculture as based on the dynamic pH and lactic acid profiles of the medium.

  17. Comparison of glycerolisation with cryopreservation methods on HIV-1 inactivation

    International Nuclear Information System (INIS)

    Van Baare, J.; Pagnon, J.; Cameron, P.; Vardaxis, N.; Middlekoop, E.; Crowe, S.

    1999-01-01

    Cryopreservation and glycerolisation are two successful long-term preservation methods for human cadaveric donor skin, which is used in the treatment of bum patients. High concentrations of glycerol has been shown to be antibacterial and virucidal. Because fear of possible transmission of HIV-1 following allograft transplantation, this study was undertaken to investigate whether HIV can be effectively eliminated from skin explants. HIV-1 Ba-L, which has been shown to infect monocytes in skin explants and also dendritic cells, was. For the experiments we used cell-free virus, exogenously HIV infected peripheral blood mononuclear cells (PBMCs) and exogenously HIV infected cadaver split skin. Different concentrations of glycerol at various temperatures and the glycerolisation procedure as used by the Euro Skin Bank were used to determine the effects on HIV-1 Ba-L infectivity. For the cryopreservation technique we used 10% DMSO and a controlled rate freezer. HIV-1 Ba-L transfer was determined by adding uninfected PBMCs to the infected material and reverse transcriptase was measured. Cell-free HIV-1 Ba-L was not inactivated by 50% glycerol but was effectively inactivated within 30 minutes by 70% and 85% glycerol at 4 degree C, room temperature and 37 degree C. In contrast, cell-free HIV-1 Ba-L was not inactivated by cryopreservation. Most importantly, we have shown that HIV-1 Ba-L present in split skin is inactivated by incubating skin in 70% glycerol for three hours at 37-C. HIV in exogenously infected skin was not inactivated by cryopreservation. High concentrations of glycerol effectively inactivates free HIV-1 Ba-L and intracellular HIV-1 Ba-L. Also the current glycerolisation procedure carried out by the Euro Skin Bank effectively inactivates infectious virus. However, the cryopreservation technique did not show any reduction in HIV-1 Ba-L infectivity

  18. Inactivation of a putative efflux pump (LmrB) in Streptococcus mutans results in altered biofilm structure and increased exopolysaccharide synthesis: implications for biofilm resistance.

    Science.gov (United States)

    Liu, Jia; Zhang, Jianying; Guo, Lihong; Zhao, Wei; Hu, Xiaoli; Wei, Xi

    2017-07-01

    Efflux pumps are a mechanism associated with biofilm formation and resistance. There is limited information regarding efflux pumps in Streptococcus mutans, a major pathogen in dental caries. The aim of this study was to investigate potential roles of a putative efflux pump (LmrB) in S. mutans biofilm formation and susceptibility. Upon lmrB inactivation and antimicrobial exposure, the biofilm structure and expression of other efflux pumps were examined using confocal laser scanning microscopy (CLSM) and qRT-PCR. lmrB inactivation resulted in biofilm structural changes, increased EPS formation and EPS-related gene transcription (p < 0.05), but no improvement in susceptibility was observed. The expression of most efflux pump genes increased upon lmrB inactivation when exposed to antimicrobials (p < 0.05), suggesting a feedback mechanism that activated the transcription of other efflux pumps to compensate for the loss of lmrB. These observations imply that sole inactivation of lmrB is not an effective solution to control biofilms.

  19. [Kinetics of catalase inactivation induced by ultrasonic cavitation].

    Science.gov (United States)

    Potapovich, M V; Eremin, A N; Metelitsa, D I

    2003-01-01

    Kinetic patterns of sonication-induced inactivation of bovine liver catalase (CAT) were studied in buffer solutions (pH 4-11) within the temperature range from 36 to 55 degrees C. Solutions of CAT were exposed to low-frequency (20.8 kHz) ultrasound (specific power, 48-62 W/cm2). The kinetics of CAT inactivation was characterized by effective first-order rate constants (s-1) of total inactivation (kin), thermal inactivation (*kin), and ultrasonic inactivation (kin(us)). In all cases, the following inequality was valid: kin > *kin. The value of kin(us) increased with the ultrasound power (range, 48-62 W/cm2) and exhibited a strong dependence on pH of the medium. On increasing the initial concentration of CAT (0.4-4.0 nM), kin(us) decreased. The three rate constants were minimum within the range of pH 6.5-8; their values increased considerably at pH 9. At 36-55 degrees C, temperature dependence of kin(us) was characterized by an activation energy (Eact) of 19.7 kcal/mol, whereas the value of Eact for CAT thermoinactivation was equal to 44.2 kcal/mol. Bovine serum and human serum albumins (BSA and HSA, respectively) inhibited sonication-induced CAT inactivation; complete prevention was observed at concentrations above 2.5 micrograms/ml. Dimethyl formamide (DMFA), a scavenger of hydroxyl radicals (HO.), prevented sonication-induced CAT inactivation at 10% (kin and *kin increased with the content of DMFA at concentrations in excess of 3%). The results obtained indicate that free radicals generated in the field of ultrasonic cavitation play a decisive role in the inactivation of CAT, which takes place when its solutions are exposed to low-frequency ultrasound. However, the efficiency of CAT inactivation by the radicals is determined by (1) the degree of association between the enzyme molecules in the reaction medium and (2) the composition thereof.

  20. ERADIKASI POLIO DAN IPV (INACTIVATED POLIO VACCINE

    Directory of Open Access Journals (Sweden)

    Gendrowahyuhono Gendrowahyuhono

    2012-09-01

    Full Text Available In the year 1988, World Health Organization (WHO claims that polio viruses should be eradicated after year 2000. However, until year 2010 the world have not been free from polio viruses circulation. So many effort had been achieved and it is estimated that the world will be free from polio virus after the year 2013. Control of poliomyelitis in Indonesia has been commenced since 1982 with routine immunization of polio program and the National Immunization Days (NID has been commenced since 1995,1996,2005 and 2006. When the world is free from polio virus, WHO suggests several alternative effort to maintain the world free from polio viruses : I stop the OPV (Oral Polio Vaccine and no polio immunization, 2 stop OPV and stock pile mOPV (monovalent OPV, 3 use OPV and IPV (Inactivated Polio Vaccine in a certain times, 4 use IPV only in a certain times. IPV has been used routinely in develop countries but has not been used in the developing countries. Several studies in development countries has been conducted, but had not been done in the developing countries. Indonesia collaboration with WHO has conducted the study of IPV in Yogyakarta Province since year 2002 until year 2010. The overall aim of the study is to compile the necessary data that will inform global and national decision-making regarding future polio immunization policies for the OPV cessation era. The data generated from the study will be particularly important to make decisions regarding optimal IPV use in developing tropical countries. It is unlikely that this data can be assembled through other means than through this study. The tentative result of the study shows that OPV immunization coverage in the year 2004 is 99% in four district and 93 % in the Yogyakarta city. Environment surveillance shows that there are 65.7% polio virus detected from 137 sewage samples pre IPV swich, and 4.8% polio virus detected from 83 sewage samples post IPV swich. Survey polio antibody serologis shows

  1. Structure of suicide-inactivated β-hydroxydecanoyl-thioester dehydrase

    International Nuclear Information System (INIS)

    Schwab, J.M.; Ho, C.K.; Li, W.B.; Townsend, C.A.; Salituro, G.M.

    1986-01-01

    β-Hydroxydecanoylthioester dehydrase, the key enzyme in biosynthesis of unsaturated fatty acids under anaerobic conditions, equilibrates thioesters of (R)-3-hydroxydecanoic acid, E-2-decenoic acid, and Z-3-decenoic acid. Dehydrase is irreversibly inactivated by the N-acetylcysteamine thioester of 3-decynoic acid (3-decynoyl-NAC), via dehydrase-catalyzed isomerization to 2,3-decadienoyl-NAC. To probe the relationship between normal catalysis and suicide inactivation, the structure of the inactivated enzyme has been studied. 3-[2- 13 C]Decynoyl-NAC was synthesized and incubated with dehydrase. 13 C NMR showed that attack of 2,3-decadienoyl-NAC by the active site histidine gives 3-histidinyl-3-decenoyl-NAC, which slowly rearranges to the more stable Δ 2 isomer. Model histidine-allene adducts have been made and characterized. Analysis of NMR data show that the C=C configuration of the decenoyl moiety of enzyme-bound inactivator is E. The suggestion that the mechanism of dehydrase inactivation parallels its normal mechanism of action is supported these findings

  2. Efficiency of superoxide anions in the inactivation of selected dehydrogenases

    International Nuclear Information System (INIS)

    Rodacka, Aleksandra; Serafin, Eligiusz; Puchala, Mieczyslaw

    2010-01-01

    The most ubiquitous of the primary reactive oxygen species, formed in all aerobes, is the superoxide free radical. It is believed that the superoxide anion radical shows low reactivity and in oxidative stress it is regarded mainly as an initiator of more reactive species such as · OH and ONOO - . In this paper, the effectiveness of inactivation of selected enzymes by radiation-generated superoxide radicals in comparison with the effectiveness of the other products of water radiolysis is examined. We investigate three enzymes: glyceraldehyde-3-phosphate dehydrogenase (GAPDH), alcohol dehydrogenase (ADH) and lactate dehydrogenase (LDH). We show that the direct contribution of the superoxide anion radical to GAPDH and ADH inactivation is significant. The effectiveness of the superoxide anion in the inactivation of GAPDH and ADG was only 2.4 and 2.8 times smaller, respectively, in comparison with hydroxyl radical. LDH was practically not inactivated by the superoxide anion. Despite the fact that the studied dehydrogenases belong to the same class of enzymes (oxidoreductases), all have a similar molecular weight and are tetramers, their susceptibility to free-radical damage varies. The differences in the radiosensitivity of the enzymes are not determined by the basic structural parameters analyzed. A significant role in inactivation susceptibility is played by the type of amino acid residues and their localization within enzyme molecules.

  3. Efficiency of superoxide anions in the inactivation of selected dehydrogenases

    Energy Technology Data Exchange (ETDEWEB)

    Rodacka, Aleksandra, E-mail: olakow@biol.uni.lodz.p [Department of Molecular Biophysics, University of Lodz, Banacha 12/16, 90-237 Lodz (Poland); Serafin, Eligiusz, E-mail: serafin@biol.uni.lodz.p [Laboratory of Computer and Analytical Techniques, University of Lodz, Banacha 12/16, 90-237 Lodz (Poland); Puchala, Mieczyslaw, E-mail: puchala@biol.uni.lodz.p [Department of Molecular Biophysics, University of Lodz, Banacha 12/16, 90-237 Lodz (Poland)

    2010-09-15

    The most ubiquitous of the primary reactive oxygen species, formed in all aerobes, is the superoxide free radical. It is believed that the superoxide anion radical shows low reactivity and in oxidative stress it is regarded mainly as an initiator of more reactive species such as {sup {center_dot}}OH and ONOO{sup -}. In this paper, the effectiveness of inactivation of selected enzymes by radiation-generated superoxide radicals in comparison with the effectiveness of the other products of water radiolysis is examined. We investigate three enzymes: glyceraldehyde-3-phosphate dehydrogenase (GAPDH), alcohol dehydrogenase (ADH) and lactate dehydrogenase (LDH). We show that the direct contribution of the superoxide anion radical to GAPDH and ADH inactivation is significant. The effectiveness of the superoxide anion in the inactivation of GAPDH and ADG was only 2.4 and 2.8 times smaller, respectively, in comparison with hydroxyl radical. LDH was practically not inactivated by the superoxide anion. Despite the fact that the studied dehydrogenases belong to the same class of enzymes (oxidoreductases), all have a similar molecular weight and are tetramers, their susceptibility to free-radical damage varies. The differences in the radiosensitivity of the enzymes are not determined by the basic structural parameters analyzed. A significant role in inactivation susceptibility is played by the type of amino acid residues and their localization within enzyme molecules.

  4. Inactivation of complement by Loxosceles reclusa spider venom.

    Science.gov (United States)

    Gebel, H M; Finke, J H; Elgert, K D; Cambell, B J; Barrett, J T

    1979-07-01

    Zymosan depletion of serum complement in guinea pigs rendered them highly resistant to lesion by Loxosceles reclusa spider venom. Guinea pigs deficient in C4 of the complement system are as sensitive to the venom as normal guinea pigs. The injection of 35 micrograms of whole recluse venom intradermally into guinea pigs lowered their complement level by 35.7%. Brown recluse spider venom in concentrations as slight as 0.02 micrograms protein/ml can totally inactivate one CH50 of guinea pig complement in vitro. Bee, scorpion, and other spider venoms had no influence on the hemolytic titer of complement. Fractionation of recluse spider venom by Sephadex G-200 filtration separated the complement-inactivating property of the venom into three major regions which could be distinguished on the basis of heat stability as well as size. None was neutralized by antivenom. Polyacrylamide gel electrophoresis of venom resolved the complement inactivators into five fractions. Complement inactivated by whole venom or the Sephadex fractions could be restored to hemolytic activity by supplements of fresh serum but not by heat-inactivated serum, pure C3, pure C5, or C3 and C5 in combination.

  5. Inactivation of viruses in labile blood derivatives. II. Physical methods

    International Nuclear Information System (INIS)

    Horowitz, B.; Wiebe, M.E.; Lippin, A.; Vandersande, J.; Stryker, M.H.

    1985-01-01

    The thermal inactivation of viruses in labile blood derivatives was evaluated by addition of marker viruses (VSV, Sindbis, Sendai, EMC) to anti-hemophilic factor (AHF) concentrates. The rate of virus inactivation at 60 degrees C was decreased by at least 100- to 700-fold by inclusion of 2.75 M glycine and 50 percent sucrose, or 3.0 M potassium citrate, additives which contribute to retention of protein biologic activity. Nonetheless, at least 10(4) infectious units of each virus was inactivated within 10 hours. Increasing the temperature from 60 to 70 or 80 degrees C caused a 90 percent or greater loss in AHF activity. An even greater decline in the rate of virus inactivation was observed on heating AHF in the lyophilized state, although no loss in AHF activity was observed after 72 hours of heating at 60 degrees C. Several of the proteins present in lyophilized AHF concentrates displayed an altered electrophoretic mobility as a result of exposure to 60 degrees C for 24 hours. Exposure of lyophilized AHF to irradiation from a cobalt 60 source resulted in an acceptable yield of AHF at 1.0, but not at 2.0, megarads. At 1 megarad, greater than or equal to 6.0 logs of VSV and 3.3 logs of Sindbis virus were inactivated

  6. Pulsed dielectric barrier discharge for Bacillus subtilis inactivation in water

    Science.gov (United States)

    Hernández-Arias, A. N.; Rodríguez-Méndez, B. G.; López-Callejas, R.; Valencia-Alvarado, R.; Mercado-Cabrera, A.; Peña-Eguiluz, R.; Barocio, S. R.; Muñoz-Castro, A. E.; de la Piedad Beneitez, A.

    2012-06-01

    The inactivation of Bacillus subtilis bacteria in water has been experimentally studied by means of a pulsed dielectric barrier discharge (PDBD) in a coaxial reactor endowed with an alumina dielectric. The plasma source is capable of operating at atmospheric pressure with gas, water or hybrid gas-liquid media at adjustable 25 kV pulses, 30 μs long and at a 500 Hz frequency. In order to evaluate the inactivation efficiency of the system, a set of experiments were designed on the basis of oxygen flow control. The initial data have showed a significant bacterial rate reduction of 103-107 CFU/mL. Additional results proved that applying an oxygen flow for a few seconds during the PDBD treatment inactivates the Bacillus subtilis population with 99.99% effectiveness. As a reference, without gas flow but with the same exposure times, this percentage is reduced to ~90%. The analysis of the relationship between inactivation rate and chemical species in the discharge has been carried out using optical emission spectroscopy as to identifying the main reactive species. Reactive oxygen species such as atomic oxygen and ozone tuned out to be the dominant germicidal species. Some proposed inactivation mechanisms of this technique are discussed.

  7. Removal of detergents from SDS-inactivated dextransucrase

    International Nuclear Information System (INIS)

    Husman, D.W.; Mayer, R.M.

    1986-01-01

    Dextransucrase, which is rapidly inactivated by SDS, can be reactivated upon the addition of Triton X-100. Purification of the enzyme, in good yield and homogeneity, has been achieved by chromatography in the presence of SDS. The purified enzyme can be reactivated with Triton, but has large amounts of detergents. It was important to develop procedures for their removal. Density gradient centrifugation of SDS-inactivated or Triton-reactivated enzyme, treatment with Extracti-Gel D (Pierce) or chromatography on hydroxyl apatite (HA), have been examined for their effectiveness in providing detergent-free enzyme in good yield. Ultracentrifugation of SDS-inactivated protein provided limited recovery of active enzyme, but suggested that reactivation could be achieved by the simple removal of the detergent. While similar behavior was observed when the enzyme was eluted from Extracti-Gel, it was also shown that the limited recovery was a result of irreversible inactivation of the enzyme. Recovery could be improved if the enzyme was collected in solutions containing Triton, which has been reported to be a stabilizer. Chromatography of SDS-inactivated enzyme on HA also yielded active enzyme. Good recovery was obtained when Triton-reactivated enzyme was employed in these studies. The degree of detergent removal was determined by utilizing radiolabelled SDS and Triton X-100

  8. Thermal and high pressure inactivation kinetics of blueberry peroxidase.

    Science.gov (United States)

    Terefe, Netsanet Shiferaw; Delon, Antoine; Versteeg, Cornelis

    2017-10-01

    This study for the first time investigated the stability and inactivation kinetics of blueberry peroxidase in model systems (McIlvaine buffer, pH=3.6, the typical pH of blueberry juice) during thermal (40-80°C) and combined high pressure-thermal processing (0.1-690MPa, 30-90°C). At 70-80°C, the thermal inactivation kinetics was best described by a biphasic model with ∼61% labile and ∼39% stable fractions at temperature between 70 and 75°C. High pressure inhibited the inactivation of the enzyme with no inactivation at pressures as high as 690MPa and temperatures less than 50°C. The inactivation kinetics of the enzyme at 60-70°C, and pressures higher than 500MPa was best described by a first order biphasic model with ∼25% labile fraction and 75% stable fraction. The activation energy values at atmospheric pressure were 548.6kJ/mol and 324.5kJ/mol respectively for the stable and the labile fractions. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  9. Pulsed dielectric barrier discharge for Bacillus subtilis inactivation in water

    International Nuclear Information System (INIS)

    Hernández-Arias, A N; López-Callejas, R; De la Piedad Beneitez, A; Rodríguez-Méndez, B G; Valencia-Alvarado, R; Mercado-Cabrera, A; Peña-Eguiluz, R; Barocio, S R; Muñoz-Castro, A E

    2012-01-01

    The inactivation of Bacillus subtilis bacteria in water has been experimentally studied by means of a pulsed dielectric barrier discharge (PDBD) in a coaxial reactor endowed with an alumina dielectric. The plasma source is capable of operating at atmospheric pressure with gas, water or hybrid gas-liquid media at adjustable 25 kV pulses, 30 μs long and at a 500 Hz frequency. In order to evaluate the inactivation efficiency of the system, a set of experiments were designed on the basis of oxygen flow control. The initial data have showed a significant bacterial rate reduction of 10 3 -10 7 CFU/mL. Additional results proved that applying an oxygen flow for a few seconds during the PDBD treatment inactivates the Bacillus subtilis population with 99.99% effectiveness. As a reference, without gas flow but with the same exposure times, this percentage is reduced to ∼90%. The analysis of the relationship between inactivation rate and chemical species in the discharge has been carried out using optical emission spectroscopy as to identifying the main reactive species. Reactive oxygen species such as atomic oxygen and ozone tuned out to be the dominant germicidal species. Some proposed inactivation mechanisms of this technique are discussed.

  10. Whole-genome analyses of speciation events in pathogenic Brucellae

    Energy Technology Data Exchange (ETDEWEB)

    Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Comerci, Diego J. [Universidad Nacional de General San Martin; Tolmasky, Marcelo E. [California State University; Larimer, Frank W [ORNL; Malfatti, Stephanie [Lawrence Livermore National Laboratory (LLNL); Vergez, Lisa [Lawrence Livermore National Laboratory (LLNL); Aguero, Fernan [Universidad Nacional de General San Martin; Land, Miriam L [ORNL; Ugalde, Rodolfo A. [Universidad Nacional de General San Martin; Garcia, Emilio [Lawrence Livermore National Laboratory (LLNL)

    2005-12-01

    Despite their high DNA identity and a proposal to group classical Brucella species as biovars of Brucella melitensis, the commonly recognized Brucella species can be distinguished by distinct biochemical and fatty acid characters, as well as by a marked host range (e.g., Brucella suis for swine, B. melitensis for sheep and goats, and Brucella abortus for cattle). Here we present the genome of B. abortus 2308, the virulent prototype biovar 1 strain, and its comparison to the two other human pathogenic Brucella species and to B. abortus field isolate 9-941. The global distribution of pseudogenes, deletions, and insertions supports previous indications that B. abortus and B. melitensis share a common ancestor that diverged from B. suis. With the exception of a dozen genes, the genetic complements of both B. abortus strains are identical, whereas the three species differ in gene content and pseudogenes. The pattern of species-specific gene inactivations affecting transcriptional regulators and outer membrane proteins suggests that these inactivations may play an important role in the establishment of host specificity and may have been a primary driver of speciation in the genus Brucella. Despite being nonmotile, the brucellae contain flagellum gene clusters and display species-specific flagellar gene inactivations, which lead to the putative generation of different versions of flagellum-derived structures and may contribute to differences in host specificity and virulence. Metabolic changes such as the lack of complete metabolic pathways for the synthesis of numerous compounds (e.g., glycogen, biotin, NAD, and choline) are consistent with adaptation of brucellae to an intracellular life-style.

  11. Pathogenic mycoflora on carrot seeds

    Directory of Open Access Journals (Sweden)

    Bogdan Nowicki

    2013-12-01

    Full Text Available Altogether 300 seed samples were collected during 9 years in 8 regions of Poland and the fungi Were isolated and their pathogenicity to carrot seedlings was examined. Alternaria rudicina provcd to be the most important pathogen although. A. alternata was more common. The other important pathogens were Fusarium spp., Phoma spp. and Botrytis cinerea. The infection of carrot seeds by A. radicina should be used as an important criterium in seed quality evaluation.

  12. Inactivation of Heterosigma akashiwo in ballast water by circular orifice plate-generated hydrodynamic cavitation.

    Science.gov (United States)

    Feng, Daolun; Zhao, Jie; Liu, Tian

    2016-01-01

    The discharge of alien ballast water is a well-known, major reason for marine species invasion. Here, circular orifice plate-generated hydrodynamic cavitation was used to inactivate Heterosigma akashiwo in ballast water. In comparison with single- and multihole orifice plates, the conical-hole orifice plate yielded the highest inactivation percentage, 51.12%, and consumed only 6.84% energy (based on a 50% inactivation percentage). Repeating treatment, either using double series-connection or circling inactivation, elevated the inactivation percentage, yet consumed much more energy. The results indicate that conical-hole-generated hydrodynamic cavitation shows great potential as a pre-inactivation method for ballast water treatment.

  13. Development of pathogen risk assessment models for the evaluation of sludge management alternatives

    International Nuclear Information System (INIS)

    Yeager, J.G.; Sheridan, R.E.; Ward, R.L.

    1979-01-01

    The constraints imposed on sewage treatment and disposal by clean air and water legislation make it clear that, in the near future, there will be increasing amounts of sewage sludge and fewer alternatives for its disposal. Additionally, this legislation has encouraged the use of waste management procedures which emphasize the recycling of waste materials. Decisions regarding optimal methods of sludge handling will primarily be controlled by economic considerations including the intrinsic value of the sludge, the cost of transporting sludge and sludge products, and the degree of treatment necessary to make the sludge suitable for particular applications. One principal reason to treat sludge is to inactivate pathogens. However, the actual health risks posed by pathogenic species that result from different methods of sludge utilization and how these risks are affected by different treatment processes are poorly understood. Therefore, computerized models are being developed to describe pathogen transport through environmental pathways and to help predict the risk of certain sludge utilization practices

  14. Genetic screens to identify pathogenic gene variants in the common cancer predisposition Lynch syndrome

    DEFF Research Database (Denmark)

    Drost, Mark; Lützen, Anne; van Hees, Sandrine

    2013-01-01

    In many individuals suspected of the common cancer predisposition Lynch syndrome, variants of unclear significance (VUS), rather than an obviously pathogenic mutations, are identified in one of the DNA mismatch repair (MMR) genes. The uncertainty of whether such VUS inactivate MMR, and therefore...... function. When a residue identified as mutated in an individual suspected of Lynch syndrome is listed as critical in such a reverse diagnosis catalog, there is a high probability that the corresponding human VUS is pathogenic. To investigate the applicability of this approach, we have generated....... Nearly half of these critical residues match with VUS previously identified in individuals suspected of Lynch syndrome. This aids in the assignment of pathogenicity to these human VUS and validates the approach described here as a diagnostic tool. In a wider perspective, this work provides a model...

  15. Innate scavenger receptor-A regulates adaptive T helper cell responses to pathogen infection

    Science.gov (United States)

    Xu, Zhipeng; Xu, Lei; Li, Wei; Jin, Xin; Song, Xian; Chen, Xiaojun; Zhu, Jifeng; Zhou, Sha; Li, Yong; Zhang, Weiwei; Dong, Xiaoxiao; Yang, Xiaowei; Liu, Feng; Bai, Hui; Chen, Qi; Su, Chuan

    2017-01-01

    The pattern recognition receptor (PRR) scavenger receptor class A (SR-A) has an important function in the pathogenesis of non-infectious diseases and in innate immune responses to pathogen infections. However, little is known about the role of SR-A in the host adaptive immune responses to pathogen infection. Here we show with mouse models of helminth Schistosoma japonicum infection and heat-inactivated Mycobacterium tuberculosis stimulation that SR-A is regulated by pathogens and suppresses IRF5 nuclear translocation by direct interaction. Reduced abundance of nuclear IRF5 shifts macrophage polarization from M1 towards M2, which subsequently switches T-helper responses from type 1 to type 2. Our study identifies a role for SR-A as an innate PRR in regulating adaptive immune responses. PMID:28695899

  16. Chlorine inactivation of fungal spores on cereal grains.

    Science.gov (United States)

    Andrews, S; Pardoel, D; Harun, A; Treloar, T

    1997-04-01

    Although 0.4% chlorine for 2 min has been recommended for surface disinfection of food samples before direct plating for fungal enumeration, this procedure may not be adequate for highly contaminated products. The effectiveness of a range of chlorine solutions was investigated using barley samples artificially contaminated with four different concentrations of Aspergillus flavus. A. niger, A. ochraceus, Eurotium repens, Penicillium brevicompactum P. chrysogenum and Cladosporium cladosporioides. At initial contamination levels greater than 10(4)/g, 0.4% chlorine did not inactivate sufficient spores to produce less than 20% contamination. Of the test fungi, ascospores of E. repens were the most resistant to chlorine inactivation, whereas the conidia of C. cladosporioides were the most sensitive. Rinsing the samples with 70% ethanol improved the effectiveness of the recommended surface disinfection procedure. However, some ethanol appears to permeate into the grains and may inactivate sensitive internal fungi, although a minimal effect only was observed on wheat infected with Alternaria.

  17. Lipase inactivation in wheat germ by gamma irradiation

    International Nuclear Information System (INIS)

    Jha, Pankaj Kumar; Kudachikar, V.B.; Kumar, Sourav

    2013-01-01

    An attempt was made to improve the shelf life of wheat germ by optimizing processing conditions involving γ-irradiation. Studies were carried out to investigate the effect of γ-irradiation (0–30 kGy doses) on the chemical composition of wheat germ with respect to variation in moisture, total ash, crude fat, free fatty acid, protein and lipase activity. The results demonstrate that shelf stability of wheat germ was achieved by inactivation of lipase at doses of γ-irradiation greater than 12 kGy. - Highlights: Ø γ-irradiation was found to inactivate Lipase present in Wheat Germ. Ø The treatment did not result in significant changes in Total Ash, Moisture and Protein Content of Wheat Germ. Ø The irradiation at 30 kGy resulted in 31.2 % inactivation of Lipase in Wheat Germ

  18. Evaluation of genetically inactivated alpha toxin for protection in multiple mouse models of Staphylococcus aureus infection.

    Directory of Open Access Journals (Sweden)

    Rebecca A Brady

    Full Text Available Staphylococcus aureus is a major human pathogen and a leading cause of nosocomial and community-acquired infections. Development of a vaccine against this pathogen is an important goal. While S. aureus protective antigens have been identified in the literature, the majority have only been tested in a single animal model of disease. We wished to evaluate the ability of one S. aureus vaccine antigen to protect in multiple mouse models, thus assessing whether protection in one model translates to protection in other models encompassing the full breadth of infections the pathogen can cause. We chose to focus on genetically inactivated alpha toxin mutant HlaH35L. We evaluated the protection afforded by this antigen in three models of infection using the same vaccine dose, regimen, route of immunization, adjuvant, and challenge strain. When mice were immunized with HlaH35L and challenged via a skin and soft tissue infection model, HlaH35L immunization led to a less severe infection and decreased S. aureus levels at the challenge site when compared to controls. Challenge of HlaH35L-immunized mice using a systemic infection model resulted in a limited, but statistically significant decrease in bacterial colonization as compared to that observed with control mice. In contrast, in a prosthetic implant model of chronic biofilm infection, there was no significant difference in bacterial levels when compared to controls. These results demonstrate that vaccines may confer protection against one form of S. aureus disease without conferring protection against other disease presentations and thus underscore a significant challenge in S. aureus vaccine development.

  19. Inactivation of VHSV by infiltration and salt under experimental conditions

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Jørgensen, Claus; Olesen, Niels Jørgen

    2014-01-01

    At the moment the only legal method in Denmark to sanitize wastewater from fish cutting plants is by infiltration. To evaluate the inactivation effect of infiltration on VHSV an experimental examination was initiated. A column packed with gravel as top- and bottom layer (total of 22 cm) and a mid...... be a valuable method to sanitize VHSV infected water. Changes in temperature, pH, earth types in the area used for infiltration etc. may change the virus reduction, though. As some of the fish cutting plants are also smoking rainbow trout fillets, the question arose whether a brine solution will inactivate VHSV...

  20. Inactivated H9N2 avian influenza virus vaccine with gel-primed and mineral oil-boosted regimen could produce improved immune response in broiler breeders.

    Science.gov (United States)

    Lee, D-H; Kwon, J-S; Lee, H-J; Lee, Y-N; Hur, W; Hong, Y-H; Lee, J-B; Park, S-Y; Choi, I-S; Song, C-S

    2011-05-01

    The frequent economic losses incurred with H9N2 low pathogenic avian influenza viruses (LPAI) infection have raised serious concerns for the poultry industry. A 1-dose regimen with inactivated H9N2 LPAI vaccine could not prevent vaccinated poultry from becoming infected and from shedding wild viruses. A study was conducted to determine whether a 2-dose regimen of inactivated H9N2 LPAI vaccine could enhance the immunologic response in chickens. Such gel-primed and mineral oil-boosted regimen has produced encouraging results associated with improved immune responses to an H9N2 LPAI. This strategy could be cost effective and helpful for preventing avian influenza virus in the poultry industry.

  1. Pathogenic agents in freshwater resources

    Science.gov (United States)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  2. Comparative proteomic analysis of pathogenic and non-pathogenic strains from the swine pathogen Mycoplasma hyopneumoniae

    Directory of Open Access Journals (Sweden)

    Klein Cátia S

    2009-12-01

    Full Text Available Abstract Background Mycoplasma hyopneumoniae is a highly infectious swine pathogen and is the causative agent of enzootic pneumonia (EP. Following the previous report of a proteomic survey of the pathogenic 7448 strain of swine pathogen, Mycoplasma hyopneumoniae, we performed comparative protein profiling of three M. hyopneumoniae strains, namely the non-pathogenic J strain and the two pathogenic strains 7448 and 7422. Results In 2DE comparisons, we were able to identify differences in expression levels for 67 proteins, including the overexpression of some cytoadherence-related proteins only in the pathogenic strains. 2DE immunoblot analyses allowed the identification of differential proteolytic cleavage patterns of the P97 adhesin in the three strains. For more comprehensive protein profiling, an LC-MS/MS strategy was used. Overall, 35% of the M. hyopneumoniae genome coding capacity was covered. Partially overlapping profiles of identified proteins were observed in the strains with 81 proteins identified only in one strain and 54 proteins identified in two strains. Abundance analysis of proteins detected in more than one strain demonstrates the relative overexpression of 64 proteins, including the P97 adhesin in the pathogenic strains. Conclusions Our results indicate the physiological differences between the non-pathogenic strain, with its non-infective proliferate lifestyle, and the pathogenic strains, with its constitutive expression of adhesins, which would render the bacterium competent for adhesion and infection prior to host contact.

  3. Selective removal and inactivation of bacteria by nanoparticle composites prepared by surface modification of montmorillonite with quaternary ammonium compounds.

    Science.gov (United States)

    Khalil, Rowaida K S

    2013-10-01

    The purpose of the present study was to prepare new nanocomposites with antibacterial activities by surface modification of montmorillonite using quaternary ammonium compounds that are widely applied as disinfectants and antiseptics in food-processing environments. The intercalation of four quaternary ammonium compounds namely benzalkonium chloride, cetylpyridinium chloride monohydrate, hexadecyltrimethylammonium bromide, tetraethylammonium chloride hydrate into montmorillonite layers was confirmed by X-ray diffraction. The antibacterial influences of the modified clay variants against important foodborne pathogens differed based on modifiers quantities, microbial cell densities, and length of contact. Elution experiments through 0.1 g of the studied montmorillonite variants indicated that Staphylococcus aureus, Pseudomonas aeroginosa, and Listeria monocytogenes were the most sensitive strains. 1 g of hexadecyltrimethylammonium bromide intercalated montmorillonites demonstrated maximum inactivation of L. monocytogenes populations, with 4.5 log c.f.u./ml units of reduction. In adsorption experiments, 0.1 g of tetraethylammonium chloride hydrate montmorillonite variants significantly reduced the growth of Escherichia coli O157:H7, L. monocytogenes, and S. aureus populations by 5.77, 6.33, and 7.38 log units respectively. Growth of wide variety of microorganisms was strongly inhibited to undetectable levels (benzalkonium chloride montmorillonite variants. This investigation highlights that reduction in counts of microbial populations adsorbed to the new nanocomposites was substantially different from that in elution experiments, where interactions of nanocomposites with bacteria were specific and more complex than simple ability to inactivate. Treatment columns packed with modified variants maintained their inactivation capacity to the growth of Salmonella Tennessee and S. aureus populations after 48 h of incubation at room temperature with maximum reductions

  4. Inactivation of Bacillus cereus vegetative cells by gastric acid and bile during in vitro gastrointestinal transit

    Directory of Open Access Journals (Sweden)

    Ceuppens Siele

    2012-10-01

    Full Text Available Abstract Background The foodborne pathogen Bacillus cereus can cause diarrhoeal food poisoning by production of enterotoxins in the small intestine. The prerequisite for diarrhoeal disease is thus survival during gastrointestinal passage. Methods Vegetative cells of 3 different B. cereus strains were cultivated in a real composite food matrix, lasagne verde, and their survival during subsequent simulation of gastrointestinal passage was assessed using in vitro experiments simulating transit through the human upper gastrointestinal tract (from mouth to small intestine. Results No survival of vegetative cells was observed, despite the high inoculum levels of 7.0 to 8.0 log CFU/g and the presence of various potentially protective food components. Significant fractions (approx. 10% of the consumed inoculum of B. cereus vegetative cells survived gastric passage, but they were subsequently inactivated by bile exposure in weakly acidic intestinal medium (pH 5.0. In contrast, the low numbers of spores present (up to 4.0 log spores/g showed excellent survival and remained viable spores throughout the gastrointestinal passage simulation. Conclusion Vegetative cells are inactivated by gastric acid and bile during gastrointestinal passage, while spores are resistant and survive. Therefore, the physiological form (vegetative cells or spores of the B. cereus consumed determines the subsequent gastrointestinal survival and thus the infective dose, which is expected to be much lower for spores than vegetative cells. No significant differences in gastrointestinal survival ability was found among the different strains. However, considerable strain variability was observed in sporulation tendency during growth in laboratory medium and food, which has important implications for the gastrointestinal survival potential of the different B. cereus strains.

  5. Efficient in vitro photodynamic inactivation of Candida albicans by repetitive light doses

    Science.gov (United States)

    Torres-Hurtado, S. A.; Ramírez Ramírez, J.; Ramos-García, R.; Ramírez-San-Juan, J. C.; Spezzia-Mazzocco, T.

    2018-02-01

    The aim of this study was to compare the effectiveness of Rose Bengal (RB) and Methylene Blue (MB) as photosensitizers (PS) in Photodynamic Inactivation (PDI) on planktonic cultures of Candida albicans, a well-known opportunistic pathogen. RB and MB at concentrations ranging from 0.5 to 60 μM and fluences of 10, 30, 45 and 60 J/cm2 were tested. The light sources consist of an array of 12 led diodes with 30 mW of optical power each; 490-540 nm (green light) to activate RB and 600 -650 nm (red light) to activate MB. We first optimize the in vitro PDI technique using a single light dose and the optimum PS concentration. The novelty of our approach consist in reducing further the PS concentration than the optimum obtained with a single light exposure and using smaller light fluence doses by using repetitive light exposures (two to three times). MB and RB were tested for repetitive exposures at concentrations ranging from 0.1 to 10 μM, with fluences of 3 to 20 J/cm2, doses well below than those reported previously. All experiments were done in triplicate with the corresponding controls; cells without treatment, light control and dark toxicity control. RB-PDI and MB-PDI significantly reduced the number of CFU/mL when compared to the control groups. The results showed that RB was more effective than MB for C. albicans inactivation. Thus, we show that is possible to reduce significantly the amount of PS and light fluence requirements using repetitive light doses of PDI in vitro.

  6. Rotavirus Virus-Like Particles as Surrogates in Environmental Persistence and Inactivation Studies

    Science.gov (United States)

    Caballero, Santiago; Abad, F. Xavier; Loisy, Fabienne; Le Guyader, Françoise S.; Cohen, Jean; Pintó, Rosa M.; Bosch, Albert

    2004-01-01

    Virus-like particles (VLPs) with the full-length VP2 and VP6 rotavirus capsid proteins, produced in the baculovirus expression system, have been evaluated as surrogates of human rotavirus in different environmental scenarios. Green fluorescent protein-labeled VLPs (GFP-VLPs) and particles enclosing a heterologous RNA (pseudoviruses), whose stability may be monitored by flow cytometry and antigen capture reverse transcription-PCR, respectively, were used. After 1 month in seawater at 20°C, no significant differences were observed between the behaviors of GFP-VLPs and of infectious rotavirus, whereas pseudovirus particles showed a higher decay rate. In the presence of 1 mg of free chlorine (FC)/liter both tracers persisted longer in freshwater at 20°C than infectious viruses, whereas in the presence of 0.2 mg of FC/liter no differences were observed between tracers and infectious rotavirus at short contact times. However, from 30 min of contact with FC onward, the decay of infectious rotavirus was higher than that of recombinant particles. The predicted Ct value for a 90% reduction of GFP-VLPs or pseudoviruses induces a 99.99% inactivation of infectious rotavirus. Both tracers were more resistant to UV light irradiation than infectious rotavirus in fresh and marine water. The effect of UV exposure was more pronounced on pseudovirus than in GFP-VLPs. In all types of water, the UV dose to induce a 90% reduction of pseudovirus ensures a 99.99% inactivation of infectious rotavirus. Recombinant virus surrogates open new possibilities for the systematic validation of virus removal practices in actual field situations where pathogenic agents cannot be introduced. PMID:15240262

  7. Growth and inactivation of Salmonella enterica and Listeria monocytogenes in broth and validation in ground pork meat during simulated home storage abusive temperature and home pan-frying

    Directory of Open Access Journals (Sweden)

    Xiang eWang

    2015-10-01

    Full Text Available Ground pork meat with natural microbiota and inoculated with low initial densities (1-10 or 10-100 CFU/g of Salmonella enterica or Listeria monocytogenes was stored under abusive temperature at 10°C and thermally treated by a simulated home pan-frying procedure. The growth and inactivation characteristics were also evaluated in broth. In ground pork meat, the population of S. enterica increased by less than one log after 12-days of storage at 10°C, whereas L. monocytogenes increased by 2.3 to 2.8 log units. No unusual intrinsic heat resistance of the pathogens was noted when tested in broth at 60°C although shoulders were observed on the inactivation curves of L. monocytogenes. After growth of S. enterica and L. monocytogenes at 10°C for 5 days to levels of 1.95 log CFU/g and 3.10 log CFU/g, respectively, in ground pork meat, their inactivation in the burger subjected to a simulated home pan-frying was studied. After thermal treatment S. enterica was undetectable but L. monocytogenes was recovered in three out of six of the 25 g burger samples. Overall, the present study shows that data on growth and inactivation of broths are indicative but may underestimate as well as overestimate behavior of pathogens and thus need confirmation in food matrix conditions to assess food safety in reasonably foreseen abusive conditions of storage and usual home pan-frying of of meat burgers in Belgium.

  8. Influenza (flu) vaccine (Inactivated or Recombinant): What you need to know

    Science.gov (United States)

    ... taken in its entirety from the CDC Inactivated Influenza Vaccine Information Statement (VIS) www.cdc.gov/vaccines/hcp/vis/vis-statements/flu.html CDC review information for Inactivated Influenza VIS: ...

  9. Use of In Situ-Generated Dimethyldioxirane for Inactivation of Biological Agents

    National Research Council Canada - National Science Library

    Wallace, William H; Bushway, Karen E; Miller, Susan D; Delcomyn, Carrie A; Renard, Jean J; Henley, Michael V

    2005-01-01

    ...) at neutral pH, was investigated for inactivation of biological warfare agent simulants. The DMDO solution inactivated bacterial spores, fungal spores, vegetative bacterial cells, viruses, and protein by 7 orders of magnitude in less than 10 min...

  10. High pressure processing's potential to inactivate norovirus and other fooodborne viruses

    Science.gov (United States)

    High pressure processing (HPP) can inactivate human norovirus. However, all viruses are not equally susceptible to HPP. Pressure treatment parameters such as required pressure levels, initial pressurization temperatures, and pressurization times substantially affect inactivation. How food matrix ...

  11. Citrobacter rodentium is an unstable pathogen showing evidence of significant genomic flux.

    Directory of Open Access Journals (Sweden)

    Nicola K Petty

    2011-04-01

    Full Text Available Citrobacter rodentium is a natural mouse pathogen that causes attaching and effacing (A/E lesions. It shares a common virulence strategy with the clinically significant human A/E pathogens enteropathogenic E. coli (EPEC and enterohaemorrhagic E. coli (EHEC and is widely used to model this route of pathogenesis. We previously reported the complete genome sequence of C. rodentium ICC168, where we found that the genome displayed many characteristics of a newly evolved pathogen. In this study, through PFGE, sequencing of isolates showing variation, whole genome transcriptome analysis and examination of the mobile genetic elements, we found that, consistent with our previous hypothesis, the genome of C. rodentium is unstable as a result of repeat-mediated, large-scale genome recombination and because of active transposition of mobile genetic elements such as the prophages. We sequenced an additional C. rodentium strain, EX-33, to reveal that the reference strain ICC168 is representative of the species and that most of the inactivating mutations were common to both isolates and likely to have occurred early on in the evolution of this pathogen. We draw parallels with the evolution of other bacterial pathogens and conclude that C. rodentium is a recently evolved pathogen that may have emerged alongside the development of inbred mice as a model for human disease.

  12. An inactivated vaccine made from a U.S. field isolate of porcine epidemic disease virus is immunogenic in pigs as demonstrated by a dose-titration.

    Science.gov (United States)

    Collin, Emily A; Anbalagan, Srivishnupriya; Okda, Faten; Batman, Ron; Nelson, Eric; Hause, Ben M

    2015-03-15

    Porcine epidemic diarrhea virus (PEDV), a highly pathogenic and transmissible virus in swine, was first detected in the U.S. in May, 2013, and has caused tremendous losses to the swine industry. Due to the difficulty in isolating and growing this virus in cell culture, few vaccine studies using cell culture propagated PEDV have been performed on U.S. strains in pigs. Therefore, the objective of this study was to evaluate the humoral immune response to the selected inactivated PEDV vaccine candidate in a dose-titration manner. PEDV was isolated from a pig with diarrhea and complete genome sequencing found >99% nucleotide identity to other U.S. PEDV. Inactivated adjuvanted monovalent vaccines were administered intramuscularly to five week old pigs in a dose titration experimental design, ranging from 6.0-8.0 log10 tissue culture infective dose (TCID50/mL), to evaluate immunogenicity using a fluorescent foci neutralization assay (FFN), fluorescent microsphere immunoassay (FMIA), and enzyme-linked immunosorbent assay (ELISA) on sera. Pigs vaccinated with 8.0 log10 TCID50/mL inactivated virus showed significantly higher FFN titers as well as FMIA and ELISA values than 6.0 log10 TCID50/mL vaccinates and the negative controls. These results demonstrate the immunogenicity of a PEDV inactivated viral vaccine with a U.S. strain via dose-titration. A future vaccination-challenge study would illustrate the efficacy of an inactivated vaccine and help evaluate protective FFN titers and ELISA and FMIA responses.

  13. Effectiveness of superheated steam for inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Enteritidis phage type 30, and Listeria monocytogenes on almonds and pistachios.

    Science.gov (United States)

    Ban, Ga-Hee; Kang, Dong-Hyun

    2016-03-02

    This study was undertaken to evaluate the effectiveness of superheated steam (SHS) on the inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Enteritidis phage type (PT) 30 and Listeria monocytogenes on almonds and in-shell pistachios and to determine the effect of superheated steam heating on quality by measuring color and texture changes. Almonds and in-shell pistachios inoculated with four foodborne pathogens were treated with saturated steam (SS) at 100 °C and SHS at 125, 150, 175, and 200 °C for various times. Exposure of almonds and pistachios to SHS for 15 or 30s at 200 °C achieved >5l og reductions among all tested pathogens without causing significant changes in color values or texture parameters (P>0.05). For both almonds and pistachios, acid and peroxide values (PV) following SS and SHS treatment for up to 15s and 30s, respectively, were within the acceptable range (PV<1.0 meq/kg). These results show that thermal application of 200 °C SHS treatment for 15s and 30s did not affect the quality of almonds and pistachios, respectively. Therefore, SHS treatment is a very promising alternative technology for the tree nuts industry by improving inactivation of foodborne pathogens on almonds and pistachios while simultaneously reducing processing time. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Infectious pancreatic necrosis virus in fish by-products is inactivated with inorganic acid (pH 1) and base (pH 12).

    Science.gov (United States)

    Myrmel, M; Modahl, I; Nygaard, H; Lie, K M

    2014-04-01

    The aquaculture industry needs a simple, inexpensive and safe method for the treatment of fish waste without heat. Microbial inactivation by inorganic acid (HCl) or base (KOH) was determined using infectious pancreatic necrosis virus (IPNV) as a model organism for fish pathogens. Salmonella and spores of Clostridium perfringens were general hygiene indicators in supplementary examinations. IPNV, which is considered to be among the most chemical- and heat-resistant fish pathogens, was reduced by more than 3 log in 4 h at pH 1.0 and pH 12.0. Salmonella was rapidly inactivated by the same treatment, whereas spores of C. perfringens were hardly affected. The results indicate that low and high pH treatment could be particularly suitable for fish waste destined for biogas production. pH treatment at aquaculture production sites could reduce the spread of fish pathogens during storage and transportation without disturbing the anaerobic digestion process. The treatment could also be an alternative to the current energy-intensive steam pressure sterilization of fish waste to be used by the bioenergy, fertilizer and soil improver industries. © 2013 John Wiley & Sons Ltd.

  15. Inactivation of proteinaceous protease inhibitors of soybeans by isolated fungi

    NARCIS (Netherlands)

    Meijer, M.M.T.; Spekking, W.T.J.; Sijtsma, L.; Bont, de J.A.M.

    1995-01-01

    Proteinaceous protease inhibitors, Kunitz Soybean Trypsin Inhibitor (KSTI) and Bowman Birk Inhibitor (BBI), in legume seeds reduce the digestibility of proteins in feed of monogastric animals. Enzymatic inactivation of these inhibitors will increase the nutritional value of the feed. The aim of this

  16. Efficient Bacteria Inactivation by Ultrasound in Municipal Wastewater

    Directory of Open Access Journals (Sweden)

    Leonel Ernesto Amabilis-Sosa

    2018-04-01

    Full Text Available The reuse of treated wastewaters could contribute to reducing water stress. In this research, ultrasound application on bacterial inactivation in municipal wastewater (MWW was evaluated. Total and fecal coliforms were used as standard fecal indicators; volatile suspended solids (VSS were analyzed too. Samples were taken from the effluent of secondary clarifiers. In addition, inactivation tests were carried out on pure cultures of E. coli (EC and B. subtilis (BS. Sonication was performed at 20 kHz, 35% amplitude and 600 W/L for 15, 30 and 45 min. After 15 min of sonication, bacterial density was reduced by 1.85 Log10 MPN/100 mL for EC and 3.16 Log10 CFU/mL for BS. After 30 min, no CFU/mL of BS were observed in MWW and, after 45 min, the reduction of total and fecal coliforms was practically 6.45 Log10 MPN/100mL. Inactivation mechanism was made by cavitation, which causes irreversible damage to the cell wall. Although high bacterial densities were employed, percentages of inactivation >99% were reached at 45 min. This research contributes to the implementation of ultrasound as a disinfection technique with high potential due to its high efficiency without producing byproducts. In fact, the water meets the guidelines for reuse in direct human contact services.

  17. Light-driven photosensitizer uptake increases Candida albicans photodynamic inactivation.

    Science.gov (United States)

    Romano, Renan A; Pratavieira, Sebastião; Silva, Ana P da; Kurachi, Cristina; Guimarães, Francisco E G

    2017-11-01

    Photodynamic Inactivation (PDI) is based on the use of a photosensitizer (PS) and light that results mainly in the production of reactive oxygen species, aiming to produce microorganism cell death. PS incubation time and light dose are key protocol parameters that influence PDI response; the correct choice of them can increase the efficiency of inactivation. The results of this study show that a minor change in the PDI protocol, namely light-driven incubation leads to a higher photosensitizer and more uniform cell uptake inside the irradiated zone. Furthermore, as the uptake increases, the damage caused by PDI also increases. The proposed light-driven incubation prior to the inactivation illumination dose has advantages when compared to the traditional PDI treatments since it can be more selective and effective. Using a violet light as pre-illumination (light-driven incubation) source and a red-light system as PDI source, it was possible to demonstrate that when compared to the traditional protocol of dark incubation, the pre-illuminated cell culture showed an inactivation increase of 7 log units. These in vitro results performed in Candida albicans cells may result in the introduction of a new protocol for PDI. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. High pressure processing inactivates human norovirus within oysters

    Science.gov (United States)

    Consumption of raw bivalve mollusks can result in norovirus infection. One potential intervention for virus-contaminated shellfish is high pressure processing (HPP). Currently HPP is known to inactivate Vibrio bacteria, hepatitis A virus, and murine norovirus within oysters. To evaluate the potentia...

  19. Method of inactivation of viral and bacterial blood contaminants

    International Nuclear Information System (INIS)

    Hackett, R.; Goodrich, R.P.; Van Borssum Waalkes, M.; Wong, V.A.

    1992-01-01

    A method is provided for inactivating viral and/or bacterial contamination in blood cellular matter, such as erythrocytes and platelets, or protein fractions. The cells or protein fractions are mixed with chemical sensitizers and irradiated with, for example, gamma or X-ray radiation

  20. Efficiency of inactivation of trypsin inhibitory activity in some selected ...

    African Journals Online (AJOL)

    Trypsin inhibitor (TI) levels in the crop seeds varied between 0.0 in Adansonia digitata and 40.8 TIU/mg in Pterocarpus osun. Efficiency of inactivation of TI by autoclaving ranged from 58.1% in Millettia thonningii to 100% in Sesbania pachycarpa and Lonchocarpus. sericeus. It is concluded that the effect of heat treatment on ...

  1. Drying of liquid food droplets : enzyme inactivation and multicomponent diffusion

    NARCIS (Netherlands)

    Meerdink, G.

    1993-01-01

    In this thesis the drying of liquid food droplets is studied from three different points of view: drying kinetics, enzyme inactivation and multicomponent diffusion. Mathematical models are developed and validated experimentally.

    Drying experiments are performed with suspended

  2. Role of polyols in thermal inactivation of shark ornithine transcarbamoylase

    Czech Academy of Sciences Publication Activity Database

    Bellocco, E.; Lagana, G.; Barreca, D.; Ficarra, S.; Tellone, E.; Magazu, S.; Branca, C.; Kotyk, Arnošt; Galtieri, A.; Leuzzi, U.

    2005-01-01

    Roč. 54, č. 4 (2005), s. 395-402 ISSN 0862-8408 Institutional research plan: CEZ:AV0Z5011922 Keywords : ornithine transcarbamoylase * thermal inactivation * shark enzyme Subject RIV: CE - Biochemistry Impact factor: 1.806, year: 2005

  3. Cellular inactivation of nitric oxide induces p53-dependent ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research August 2016; 15 (8): 1595-1603 ... Cellular inactivation of nitric oxide induces p53-dependent apoptosis in ... apoptosis induced by a selective iNOS inhibitor, N-[(3-aminomethyl) benzyl] acetamidine (1400W), .... and nitrate. ... Nitrite production was measured in culture media.

  4. LOW PRESSURE ULTRAVIOLET STUDIES FOR INACTIVATION OF GIARDIA MURIS CYSTS

    Science.gov (United States)

    This research was initiated to confirm and expand the current database for the inactivation of Giardia spp. using ultraviolet (UV) radiation. Initially, previous research that used in vitro excystation as the indicator for UV effectiveness was confirmed. Later, the in vitro excys...

  5. LOW PRESSURE ULTRAVEIOLET STUDIES FOR INACTIVATION OF GIARDIA MURIS CYSTS

    Science.gov (United States)

    Cysts of Giardia muris were inactivated using a low pressure ultravolet (UV) light source. Cyst viability was detemined by both in vitro excystation and animal infectivity. Cyst doeses were counted using a flow cytometer for the animal infectivity experiments. Using in vitro excy...

  6. Inactivation of bacteria in sewage sludge by gamma radiation

    International Nuclear Information System (INIS)

    Pandya, G.A.; Kapila, Smita; Kelkar, V.B.; Negi, Shobha; Modi, V.V.

    1987-01-01

    The survival of certain bacterial cultures suspended in sewage sludge and exposed to gamma-radiation was studied. The inactivation patterns of most of the organisms were significantly different when irradiation was performed using sewage samples collected in the summer and monsoon seasons. The summer sample collected from the anaerobic digester afforded significant protection to both Gram negative and Gram positive organisms. This was evident by the increase in dose required to bring about a 6 log cycle reduction in viable count of the bacterial cultures, when suspended in sewage samples instead of phosphate buffer. The observations made using monsoon digester samples were quite different. This sewage sludge greatly enhanced inactivation by gamma-radiation in most cases. The effects of certain chemicals on the inactivation patterns of two organisms - Salmonella typhi and Shigella flexneri - were examined. Arsenate, mercury and lead salts sensitised S. typhi, while barium acetate and sodium sulphide protected this culture against gamma-radiation. In the case of Sh. flexneri, barium acetate and iodacetamide proved to be radioprotectors. The effects of some chemicals on the inactivation pattern of Sh. flexneri cells irradiated in sludge are also discussed. (author)

  7. The radiation inactivation of glutamate and isocitrate dehydrogenases

    International Nuclear Information System (INIS)

    El Failat, R.R.A.

    1980-12-01

    The reaction of free radicals produced by ionizing radiation with the enzymes glutamate dehydrogenase (GDH) and NADP + -specific isocitrate dehydrogenase (ICDH) have been studied by steady-state and pulse radiolysis techniques. In de-aerated GDH solutions, hydroxyl radicals have been found to be the most efficient of the primary radicals generated from water in causing inactivation. The effect of reaction with the enzyme of selective free radicals (SCN) 2 - , (Br) 2 - and (I) 2 - on its activity has also been studied. In neutral solutions, the order of inactivating effectiveness is (I) 2 - > (Br) 2 - > (SCN) 2 - . In the case of the thiocyanate radical anion (SCN) 2 - , the inactivation efficiency is found to depend on KSCN concentration. The radiation inactivation of GDH at both neutral and alkaline pH is accompanied by the loss of sulphydryl groups. Pulse radiolysis was also used to determine the rate constants and the transient absorption spectra following the reaction of the free radicals with GDH. 60 Co-γ-radiolysis and pulse radiolysis were also used to study the effect of ionizing radiation on the activity of ICDH. The results obtained were similar to those of GDH. (author)

  8. Inactivation of carbenicillin by some radioresistant mutant strains

    International Nuclear Information System (INIS)

    Zahiera, T.S.; Mahmoud, M.I.; Bashandy, A.A.

    1990-01-01

    Sensitivity test of five bacterial species to carbenicillin was performed microbiologically. The bacterial species were previously isolated from high level radiation environment. All the studied species could either highly decrease the antibiotic activity or even inactivate it completely. Detailed study of the inactivation of carbenicillin by the radioresistant mutant strains B. Laterosporus, B. firmus and M. roseus was performed, in the present study. Using high performace liquid chromatography technique. The gram-positive m. roseus mutant strain seemed to be the most active mutant in degrading the antibiotic. The left over of the antibiotic attained a value of 9% of the original amount after 14 day incubation of the antibiotic with this mutant strain, while the value of the left over reached 36% and 32% after the same period of incubation with the mutants B. laterosporus and B. firmus respectively. In the case of bacillus species, the degradation of the antibiotic started at the same moment when it was added to the bacterial cultures. This fact may indicate that the inactivation of the studied antibiotic by these bacillus species was due to extracellular enzymes extracted rapidly in the surrounding medium. In the case of M. roseus the inactivation process started later. after the addition of the antibiotic to the mutant culture

  9. Indicators for suicide substrate inactivation: A kinetic investigation

    Indian Academy of Sciences (India)

    Sharmistha Dhatt

    2017-11-20

    Nov 20, 2017 ... practical ones, that can decisively conclude enzyme inactivation are considered. Steady-state approximation ... nase 1 and 2 enzymes), Exemesteme - a drug used in the treatment of breast cancer (inhibitor of aromatase enzyme), AZT and .... for a next indicator that can serve as a diagnostic tool for enzyme ...

  10. Inactivation of VHSV by Percolation and Salt Under Experimental Conditions

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Olesen, Niels Jørgen; Jørgensen, Claus

    2012-01-01

    At the moment the only legal method in Denmark to sanitize wastewater from fish cutting plants is by percolation. To evaluate the inactivation effect of percolation on VHSV an experimental examination was initiated. A column packed with gravel as top- and bottom layer (total of 22 cm) and a mid l...

  11. Inactivation of human and simian rotaviruses by chlorine dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu-Shiaw (Brookhaven National Lab., Upton, NY (USA)); Vaughn, J.M. (Univ. of New England College of Medicine, Biddeford, ME (USA))

    1990-05-01

    The inactivation of single-particle stocks of human (type 2, Wa) and simian (SA-11) rotaviruses by chlorine dioxide was investigated. Experiments were conducted at 4{degree}C in a standard phosphate-carbonate buffer. Both virus types were rapidly inactivated, within 20 s under alkaline conditions, when chlorine dioxide concentrations ranging from 0.05 to 0.2 mg/liter were used. Similar reductions of 10{sup 5}-fold in infectivity required additional exposure time of 120 s at 0.2 mg/liter for Wa and at 0.5 mg/liter for SA-11, respectively, at pH 6.0. The inactivation of both virus types was moderate a neutral pH, and the sensitivities to chlorine dioxide were similar. The observed enhancement of virucidal efficiency with increasing pH was contrary to earlier findings with chlorine- and ozone-treated rotavirus particles, where efficiencies decreased with increasing alkalinity. Comparison of 99.9% virus inactivation times revealed ozone to be the most effective virucidal agent among these three disinfectants.

  12. The inactivation of papain by high LET radiations

    International Nuclear Information System (INIS)

    Bisby, R.H.; Cundall, R.B.; Sims, H.E.; Burns, W.G.

    1984-01-01

    The effect of varying LET over a wide range (0.2-1570 eV/nm) on the radiation-induced inactivation of the enzyme papain in dilute aqueous solution has been investigated. Measurements of total, reparable and non-reparable inactivation G values in oxygen, nitrous oxide and argon saturated solutions have allowed the contributions to inactivation from radicals and hydrogen peroxide to be evaluated. At high LET the results demonstrate an increasing component due to reaction of the superoxide radical, formed from oxygen produced in the track as a primary radiolysis product. This effect was not observed in our previous study with ribonuclease due to the insensitivity of ribonuclease to inactivation by superoxide and hydrogen peroxide. The results obtained with papain clearly demonstrate a maximum in G(H 2 O 2 ) at an LET of equivalent to 140 eV/nm. Generation of O 2 within the track as a primary radiolysis product at high LET now appears to be confirmed as an important mechanism leading to reduction in the oxygen enhancement ratio for cellular systems exposed to high LET radiations (Baverstock and Burns 1981). (author)

  13. Studies on disappearance and inactivation of viruses in sewage, 2

    International Nuclear Information System (INIS)

    Yano, Kazuyoshi; Yabuuchi, Kiyoshi; Taguchi, Fumiaki.

    1985-01-01

    Methods of inactivating viruses in wastewater were studied. Polio visuses were added to the distilled water until the number of viruses reached 10sup(6.8) TCID 50 /ml, and liquid layer was 2 mm. The inactivation rate of viruses was determined at each time of ultraviolet (U.V.) irradiation (from 0.425 x 10 4 μw/cm 2 to 10.0 x 10 4 μw/cm 2 ). A linear correlation was seen between the inactivation rate of viruses and the time of U.V. irradiation obtained from logarithmic transformation. The irradiation time required for inactivation of 99.9% viruses was 15 sec when U.V. intensity was 10.0 x 10 4 μw/cm 2 and 9.6 min when it was 0.423 x 10 4 μw/cm 2 . When the U.V. intensity was 0.425 x 10 4 μw/cm 2 , the time required for inactivation was dependent on the number of viruses (120 sec in cases of 10sup(3.8) TCID 50 /ml of viruses and 720 sec in cases of 10sup(7.8) TCID 50 /ml of viruses). When viruses were added to the distilled water until the number reached 10sup(5.8) TCID 50 /ml, and the depth of water was designated as 2 mm, 10 cm, and 15 cm, the U.V. permeability was more than 89% at any depth of water, and a sixteen-min U.V. irradiation inactivated more than 99.99% of viruses. When polio viruses were added to triple step-treated water until the number reached 10sup(5.3) TCID 50 /ml, the irradiation time required for inactivation of more than 99.99% was one min when the U.V. intensity was 10.0 x 10 4 μw/cm 2 and 20 min when it was 0.425 x 10 4 μw/cm 2 . (Namekawa, K.)

  14. Strategy to inactivate Clostridium perfringens spores in meat products.

    Science.gov (United States)

    Akhtar, Saeed; Paredes-Sabja, Daniel; Torres, J Antonio; Sarker, Mahfuzur R

    2009-05-01

    The current study aimed to develop an inactivation strategy for Clostridium perfringens spores in meat through a combination of spore activation at low pressure (100-200 MPa, 7 min) and elevated temperature (80 degrees C, 10 min); spore germination at high temperatures (55, 60 or 65 degrees C); and inactivation of germinated spores with elevated temperatures (80 and 90 degrees C, 10 and 20 min) and high pressure (586 MPa, at 23 and 73 degrees C, 10 min). Low pressures (100-200 MPa) were insufficient to efficiently activate C. perfringens spores for germination. However, C. perfringens spores were efficiently activated with elevated temperature (80 degrees C, 10 min), and germinated at temperatures lethal for vegetative cells (>or= 55 degrees C) when incubated for 60 min with a mixture of L-asparagine and KCl (AK) in phosphate buffer (pH 7) and in poultry meat. Inactivation of spores (approximately 4 decimal reduction) in meat by elevated temperatures (80-90 degrees C for 20 min) required a long germination period (55 degrees C for 60 min). However, similar inactivation level was reached with shorter germination period (55 degrees C for 15 min) when spore contaminated-meat was treated with pressure-assisted thermal processing (568 MPa, 73 degrees C, 10 min). Therefore, the most efficient strategy to inactivate C. perfringens spores in poultry meat containing 50 mM AK consisted: (i) a primary heat treatment (80 degrees C, 10 min) to pasteurize and denature the meat proteins and to activate C. perfringens spores for germination; (ii) cooling of the product to 55 degrees C in about 20 min and further incubation at 55 degrees C for about 15 min for spore germination; and (iii) inactivation of germinated spores by pressure-assisted thermal processing (586 MPa at 73 degrees C for 10 min). Collectively, this study demonstrates the feasibility of an alternative and novel strategy to inactivate C. perfringens spores in meat products formulated with germinants specific for C

  15. Anti-leucine rich glioma inactivated 1 protein and anti-N-methyl-D-aspartate receptor encephalitis show distinct patterns of brain glucose metabolism in 18F-fluoro-2-deoxy-d-glucose positron emission tomography.

    Science.gov (United States)

    Wegner, Florian; Wilke, Florian; Raab, Peter; Tayeb, Said Ben; Boeck, Anna-Lena; Haense, Cathleen; Trebst, Corinna; Voss, Elke; Schrader, Christoph; Logemann, Frank; Ahrens, Jörg; Leffler, Andreas; Rodriguez-Raecke, Rea; Dengler, Reinhard; Geworski, Lilli; Bengel, Frank M; Berding, Georg; Stangel, Martin; Nabavi, Elham

    2014-06-20

    Pathogenic autoantibodies targeting the recently identified leucine rich glioma inactivated 1 protein and the subunit 1 of the N-methyl-D-aspartate receptor induce autoimmune encephalitis. A comparison of brain metabolic patterns in 18F-fluoro-2-deoxy-d-glucose positron emission tomography of anti-leucine rich glioma inactivated 1 protein and anti-N-methyl-D-aspartate receptor encephalitis patients has not been performed yet and shall be helpful in differentiating these two most common forms of autoimmune encephalitis. The brain 18F-fluoro-2-deoxy-d-glucose uptake from whole-body positron emission tomography of six anti-N-methyl-D-aspartate receptor encephalitis patients and four patients with anti-leucine rich glioma inactivated 1 protein encephalitis admitted to Hannover Medical School between 2008 and 2012 was retrospectively analyzed and compared to matched controls. Group analysis of anti-N-methyl-D-aspartate encephalitis patients demonstrated regionally limited hypermetabolism in frontotemporal areas contrasting an extensive hypometabolism in parietal lobes, whereas the anti-leucine rich glioma inactivated 1 protein syndrome was characterized by hypermetabolism in cerebellar, basal ganglia, occipital and precentral areas and minor frontomesial hypometabolism. This retrospective 18F-fluoro-2-deoxy-d-glucose positron emission tomography study provides novel evidence for distinct brain metabolic patterns in patients with anti-leucine rich glioma inactivated 1 protein and anti-N-methyl-D-aspartate receptor encephalitis.

  16. Inactivation of Escherichia coli O157:H7, salmonellae, and Campylobacter jejuni in raw ground beef by gamma irradiation

    International Nuclear Information System (INIS)

    Clavero, M.R.S.; Monk, J.D.; Beuchat, L.R.; Doyle, M.P.; Brackett, R.E.

    1994-01-01

    Raw ground beef patties inoculated with stationary-phase cells of Escherichia coli O157:H7, salmonellae, or Campylobacter jejuni were subjected to gamma irradiation (60Co) treatment, with doses ranging from 0 to 2.52 kGy. The influence of two levels of fat (8 to 14% [low fat] and 27 to 28% [high fat]) and temperature (frozen [-17 to -15 degrees C] and refrigerated [3 to 5 degrees C]) on the inactivation of each pathogen by irradiation was investigated. In ascending order of irradiation resistance, the D10 values ranged from 0.175 to 0.235 kGy (C. jejuni), from 0.241 to 0.307 kGy (E. coli O157:H7), and from 0.618 to 0.800 kGy (salmonellae). Statistical analysis revealed that E. coli O157:H7 had a significantly (P 0.05) higher D10 value when irradiated at -17 to -15 degrees C than when irradiated at 3 to 5 degrees C. Regardless of the temperature during irradiation, the level of fat did not have a significant effect on the D10 value. Salmonellae behaved like E. coli O157:H7 in low-fat beef, but temperature did not have a significant effect when the pathogen was irradiated in high-fat ground beef. Significantly higher D10 values were calculated for C. jejuni irradiated in frozen than in refrigerated low-fat beef. C. jejuni was more resistant to irradiation in low-fat beef than in high-fat beef when treatment was at -17 to -15 degrees C. Regardless of the fat level and temperature during inactivation, these pathogens were highly sensitive to gamma irradiation. An applied dose of 2.5 kGy would be sufficient to kill 10(8.1) E. coli O157:H7, 10(3.1) salmonellae, and 10(10.6) C. jejuni, resulting in a high probability of complete inactivation of populations much higher than those occasionally present in ground beef patties

  17. Inactivation as a new regulatory mechanism for neuronal Kv7 channels

    DEFF Research Database (Denmark)

    Jensen, Henrik Sindal; Grunnet, Morten; Olesen, Søren-Peter

    2007-01-01

    neuronal channels and are important for controlling excitability. Kv7.1 channels have been considered the only Kv7 channels to undergo inactivation upon depolarization. However, here we demonstrate that inactivation is also an intrinsic property of Kv7.4 and Kv7.5 channels, which inactivate to a larger...

  18. Influence of pH, Salt and Temperature on Pressure Inactivation of Hepatitis A virus

    Science.gov (United States)

    The effects of pH (3-7), NaCl (0-6%), and temperature on pressure inactivation of hepatitis A virus (HAV) were determined. The HAV samples were treated at 400 MPa for 1 min at 5, 20, and 50C. Decreasing solution pH enhanced pressure inactivation of HAV. This enhanced inactivation effect was most e...

  19. Studies on the inactivation of human parvovirus 4.

    Science.gov (United States)

    Baylis, Sally A; Tuke, Philip W; Miyagawa, Eiji; Blümel, Johannes

    2013-10-01

    Human parvovirus 4 (PARV4) is a novel parvovirus, which like parvovirus B19 (B19V) can be a contaminant of plasma pools used to prepare plasma-derived medicinal products. Inactivation studies of B19V have shown that it is more sensitive to virus inactivation strategies than animal parvoviruses. However, inactivation of PARV4 has not yet been specifically addressed. Treatment of parvoviruses by heat or low-pH conditions causes externalization of the virus genome. Using nuclease treatment combined with real-time polymerase chain reaction, the extent of virus DNA externalization was used as an indirect measure of the inactivation of PARV4, B19V, and minute virus of mice (MVM) by pasteurization of albumin and by low-pH treatment. Infectivity studies were performed in parallel for B19V and MVM. PARV4 showed greater resistance to pasteurization and low-pH treatment than B19V, although PARV4 was not as resistant as MVM. There was a 2- to 3-log reduction of encapsidated PARV4 DNA after pasteurization and low-pH treatment. In contrast, B19V was effectively inactivated while MVM was stable under these conditions. Divalent cations were found to have a stabilizing effect on PARV4 capsids. In the absence of divalent cations, even at neutral pH, there was a reduction of PARV4 titer, an effect not observed for B19V or MVM. In the case of heat treatment and incubation at low pH, PARV4 shows intermediate resistance when compared to B19V and MVM. Divalent cations seem important for stabilizing PARV4 virus particles. © 2013 American Association of Blood Banks.

  20. Inactivation of 1-aminocyclopropane-1-carboxylate oxidase involves oxidative modifications.

    Science.gov (United States)

    Barlow, J N; Zhang, Z; John, P; Baldwin, J E; Schofield, C J

    1997-03-25

    1-Aminocyclopropane-1-carboxylate (ACC) oxidase catalyzes the final step in the biosynthesis of the plant signaling molecule ethylene. It is a member of the ferrous iron dependent family of oxidases and dioxygenases and is unusual in that it displays a very short half-life under catalytic conditions, typically less than 20 min, and a requirement for CO2 as an activator. The rates of inactivation of purified, recombinant ACC oxidase from tomato under various combinations of substrates and cofactors were measured. Inactivation was relatively slow in the presence of buffer alone (t1/2 > 1 h), but fast in the presence of ferrous iron and ascorbate (t1/2 approximately 10 min). The rate of iron/ascorbate-mediated inactivation was increased by the addition of ACC, unaffected by the addition of CO2 at saturation (supplied as bicarbonate) but decreased by the addition of catalase or ACC + CO2 at saturation (supplied as bicarbonate). Iron/ascorbate-mediated inactivation was accompanied by partial proteolysis as observed by SDS-PAGE analysis. The fragmentation pattern was altered when ACC was also included, suggesting that ACC can bind to ACC oxidase in the absence of bicarbonate. N-terminal sequencing of fragments resulted in identification of an internal cleavage site which we propose is proximate to active-site bound iron. Thus, ACC oxidase inactivates via relatively slow partial unfolding of the catalytically active conformation, oxidative damage mediated via hydrogen peroxide which is catalase protectable and oxidative damage to the active site which results in partial proteolysis and is not catalase protectable.

  1. Nucleus incertus inactivation impairs spatial learning and memory in rats.

    Science.gov (United States)

    Nategh, Mohsen; Nikseresht, Sara; Khodagholi, Fariba; Motamedi, Fereshteh

    2015-02-01

    Nucleus incertus (NI) is a pontine nucleus which releases mainly GABA and relaxin-3 in rats. Its suggested functions include response to stress, arousal, and modulation of hippocampal theta rhythm. Since the role of NI in learning and memory has not been well characterized, therefore the involvement of this nucleus in spatial learning and memory and the aftermath hippocampal levels of c-fos and pCREB were evaluated. NI was targeted by implanting cannula in male rats. For reference memory, NI was inactivated by lidocaine (0.4 μl, 4%) at three stages of acquisition, consolidation and retrieval in Morris water maze paradigm. For working memory, NI was inactivated in acquisition and retrieval phases. Injection of lidocaine prior to the first training session of reference memory significantly increased the distance moved, suggesting that inactivation of NI delays acquisition in this spatial task. Inactivation also interfered with the retrieval phase of spatial reference memory, as the time in target quadrant for lidocaine group was less, and the escape latency was higher compared to the control group. However, no difference was observed in the consolidation phase. In the working memory task, with inter-trial intervals of 75 min, the escape latency was higher when NI was inactivated in the retrieval phase. In addition, c-fos and pCREB/CREB levels decreased in NI-inhibited rats. This study suggests that nucleus incertus might participate in acquisition of spatial reference, and retrieval of both spatial reference and working memory. Further studies should investigate possible roles of NI in the hippocampal plasticity. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Inactivation Effect of Antibiotic-Resistant Gene Using Chlorine Disinfection

    Directory of Open Access Journals (Sweden)

    Takashi Furukawa

    2017-07-01

    Full Text Available The aim of this study was to elucidate the inactivation effects on the antibiotic-resistance gene (vanA of vancomycin-resistant enterococci (VRE using chlorination, a disinfection method widely used in various water treatment facilities. Suspensions of VRE were prepared by adding VRE to phosphate-buffered saline, or the sterilized secondary effluent of a wastewater treatment plant. The inactivation experiments were carried out at several chlorine concentrations and stirring time. Enterococci concentration and presence of vanA were determined. The enterococci concentration decreased as chlorine concentrations and stirring times increased, with more than 7.0 log reduction occurring under the following conditions: 40 min stirring at 0.5 mg Cl2/L, 20 min stirring at 1.0 mg Cl2/L, and 3 min stirring at 3.0 mg Cl2/L. In the inactivation experiment using VRE suspended in secondary effluent, the culturable enterococci required much higher chlorine concentration and longer treatment time for complete disinfection than the cases of suspension of VRE. However, vanA was detected in all chlorinated suspensions of VRE, even in samples where no enterococcal colonies were present on the medium agar plate. The chlorine disinfection was not able to destroy antibiotic-resistance genes, though it can inactivate and decrease bacterial counts of antibiotic-resistant bacteria (ARB. Therefore, it was suggested that remaining ARB and/or antibiotic-resistance gene in inactivated bacterial cells after chlorine disinfection tank could be discharged into water environments.

  3. Transient virulence of emerging pathogens.

    Science.gov (United States)

    Bolker, Benjamin M; Nanda, Arjun; Shah, Dharmini

    2010-05-06

    Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution.

  4. Effect of milk fat content on the performance of ohmic heating for inactivation of Escherichia coli O157:H7, Salmonella enterica Serovar Typhimurium and Listeria monocytogenes.

    Science.gov (United States)

    Kim, S-S; Kang, D-H

    2015-08-01

    The effect of milk fat content on ohmic heating compared to conventional heating for inactivation of food-borne pathogens was investigated. Sterile cream was mixed with sterile buffered peptone water and adjusted to 0, 3, 7, 10% (w/v) milk fat content. These samples with varying fat content were subjected to ohmic and conventional heating. The effect of milk fat on temperature increase and electrical conductivity were investigated. Also, the protective effect of milk fat on the inactivation of foodborne pathogens was studied. For conventional heating, temperatures of samples increased with time and were not significantly (P > 0.05) different regardless of fat content. Although the inactivation rate of Escherichia coli O157:H7, Salmonella Typhimurium and L. monocytogens decreased in samples of 10% fat content, a protective effect was not observed for conventional heating. In contrast with conventional heating, ohmic heating was significantly affected by milk fat content. Temperature increased more rapidly with lower fat content for ohmic heating due to higher electrical conductivity. Nonuniform heat generation of nonhomogeneous fat-containing samples was verified using a thermal infrared camera. Also, the protective effect of milk fat on E. coli O157:H7 and Listeria monocytogenes was observed in samples subjected to ohmic heating. These results indicate that food-borne pathogens can survive in nonhomogeneous fat-containing foods subjected to ohmic heating. Therefore, more attention is needed regarding ohmic heating than conventional heating for pasteurizing fat-containing foods. The importance of adequate pasteurization for high milk fat containing foods was identified. © 2015 The Society for Applied Microbiology.

  5. Solar photocatalytic disinfection of agricultural pathogenic fungi (Curvularia sp.) in real urban wastewater.

    Science.gov (United States)

    Aguas, Yelitza; Hincapie, Margarita; Fernández-Ibáñez, Pilar; Polo-López, María Inmaculada

    2017-12-31

    The interest in developing alternative water disinfection methods that increase the access to irrigation water free of pathogens for agricultural purposes is increasing in the last decades. Advanced Oxidation Processes (AOPs) have been demonstrated to be very efficient for the abatement of several kind of pathogens in contaminated water. The purpose of the current study was to evaluate and compare the capability of several solar AOPs for the inactivation of resistant spores of agricultural fungi. Solar photoassisted H 2 O 2 , solar photo-Fenton at acid and near-neutral pH, and solar heterogeneous photocatalysis using TiO 2, with and without H 2 O 2 , have been studied for the inactivation of spores of Curvularia sp., a phytopathogenic fungi worldwide found in soils and crops. Different concentrations of reagents and catalysts were evaluated at bench scale (solar vessel reactors, 200mL) and at pilot plant scale (solar Compound Parabolic Collector-CPC reactor, 20L) under natural solar radiation using distilled water (DW) and real secondary effluents (SE) from a municipal wastewater treatment plant. Inactivation order of Curvularia sp. in distilled water was determined, i.e. TiO 2 /H 2 O 2 /sunlight (100/50mgL -1 )>H 2 O 2 /sunlight (40mgL -1 )>TiO 2 /sunlight (100mgL -1 )>photo-Fenton with 5/10mgL -1 of Fe 2+ /H 2 O 2 at pH3 and near-neutral pH. For the case of SE, at near neutral pH, the most efficient solar process was H 2 O 2 /Solar (60mgL -1 ); nevertheless, the best Curvularia sp. inactivation rate was obtained with photo-Fenton (10/20mgL -1 of Fe 2+ /H 2 O 2 ) requiring a previous water adicification to pH3, within 300 and 210min of solar treatment, respectively. These results show the efficiency of solar AOPs as a feasible option for the inactivation of resistant pathogens in water for crops irrigation, even in the presence of organic matter (average Dissolved Organic Carbon (DOC): 24mgL -1 ), and open a window for future wastewater reclamation and irrigation

  6. Inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in ready-to-bake cookie dough by gamma and electron beam irradiation.

    Science.gov (United States)

    Jeong, Seul-Gi; Kang, Dong-Hyun

    2017-06-01

    This study was conducted to investigate the efficacy of gamma and electron beam irradiation to inactivate foodborne pathogens in ready-to-bake cookie dough and to determine the effect on quality by measuring color and texture changes. Cookie dough inoculated with Escherichia coli O157:H7, Salmonella Typhimurium, or Listeria monocytogenes was subjected to gamma and electron beam irradiation, with doses ranging from 0 to 3 kGy. As the radiation dose increased, the inactivation effect increased among all tested pathogens. After 3.0 kGy of gamma and electron beam irradiation, numbers of inoculated pathogens were reduced to below the detection limit (1 log CFU/g). The D 10 -values of E. coli O157:H7, S. Typhimurium, and L. monocytogenes in cookie dough treated with gamma rays were 0.53, 0.51, and 0.71 kGy, respectively, which were similar to those treated by electron beam with the same dose. Based on the D 10 -value of pathogens in cookie dough, L. monocytogenes showed more resistance to both treatments than did E. coli O157:H7 and S. Typhimurium. Color values and textural characteristics of irradiated cookie dough were not significantly (P > 0.05) different from the control. These results suggest that irradiation can be applied to control pathogens in ready-to-bake cookie dough products without affecting quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Agricultural pathogen decontamination technology-reducing the threat of infectious agent spread.

    Energy Technology Data Exchange (ETDEWEB)

    Betty, Rita G.; Bieker, Jill Marie; Tucker, Mark David

    2005-10-01

    Outbreaks of infectious agricultural diseases, whether natural occurring or introduced intentionally, could have catastrophic impacts on the U.S. economy. Examples of such agricultural pathogens include foot and mouth disease (FMD), avian influenza (AI), citrus canker, wheat and soy rust, etc. Current approaches to mitigate the spread of agricultural pathogens include quarantine, development of vaccines for animal diseases, and development of pathogen resistant crop strains in the case of plant diseases. None of these approaches is rapid, and none address the potential persistence of the pathogen in the environment, which could lead to further spread of the agent and damage after quarantine is lifted. Pathogen spread in agricultural environments commonly occurs via transfer on agricultural equipment (transportation trailers, tractors, trucks, combines, etc.), having components made from a broad range of materials (galvanized and painted steel, rubber tires, glass and Plexiglas shields, etc), and under conditions of heavy organic load (mud, soil, feces, litter, etc). A key element of stemming the spread of an outbreak is to ensure complete inactivation of the pathogens in the agricultural environment and on the equipment used in those environments. Through the combination of enhanced agricultural pathogen decontamination chemistry and a validated inactivation verification methodology, important technologies for incorporation as components of a robust response capability will be enabled. Because of the potentially devastating economic impact that could result from the spread of infectious agricultural diseases, the proposed capability components will promote critical infrastructure protection and greater border and food supply security. We investigated and developed agricultural pathogen decontamination technologies to reduce the threat of infectious-agent spread, and thus enhance agricultural biosecurity. Specifically, enhanced detergency versions of the patented

  8. Ecological niche of plant pathogens

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-06-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread. 

  9. Ecological niche of plant pathogens

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-02-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important for the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread.

  10. Effectiveness of Standard UV Depuration at Inactivating Cryptosporidium parvum Recovered from Spiked Pacific Oysters (Crassostrea gigas)▿

    Science.gov (United States)

    Sunnotel, O.; Snelling, W. J.; McDonough, N.; Browne, L.; Moore, J. E.; Dooley, J. S. G.; Lowery, C. J.

    2007-01-01

    When filter-feeding shellfish are consumed raw, because of their ability to concentrate and store waterborne pathogens, they are being increasingly associated with human gastroenteritis and have become recognized as important pathogen vectors. In the shellfish industry, UV depuration procedures are mandatory to reduce pathogen levels prior to human consumption. However, these guidelines are based around more susceptible fecal coliforms and Salmonella spp. and do not consider Cryptosporidium spp., which have significant resistance to environmental stresses. Thus, there is an urgent need to evaluate the efficiency of standard UV depuration against the survival of Cryptosporidium recovered from shellfish. Our study found that in industrial-scale shellfish depuration treatment tanks, standard UV treatment resulted in a 13-fold inactivation of recovered, viable C. parvum oocysts from spiked (1 × 106 oocysts liter −1) Pacific oysters. Depuration at half power also significantly reduced (P oysters. While UV treatment resulted in significant reductions of recovered viable oocysts, low numbers of viable oocysts were still recovered from oysters after depuration, making their consumption when raw a public health risk. Our study highlights the need for increased periodic monitoring programs for shellfish harvesting sites, improved depuration procedures, and revised microbial quality control parameters, including Cryptosporidium assessment, to minimize the risk of cryptosporidiosis. PMID:17574996

  11. Antibiotic-resistant bacteria: prevalence in food and inactivation by food-compatible compounds and plant extracts.

    Science.gov (United States)

    Friedman, Mendel

    2015-04-22

    Foodborne antibiotic-resistant pathogenic bacteria such as Campylobacter jejuni, Bacillus cereus, Clostridium perfringens, Escherichia coli, Salmonella enterica, Staphylococcus aureus, Vibrio cholerae, and Vibrio parahemolyticus can adversely affect animal and human health, but a better understanding of the factors involved in their pathogenesis is needed. To help meet this need, this overview surveys and interprets much of our current knowledge of antibiotic (multidrug)-resistant bacteria in the food chain and the implications for microbial food safety and animal and human health. Topics covered include the origin and prevalence of resistant bacteria in the food chain (dairy, meat, poultry, seafood, and herbal products, produce, and eggs), their inactivation by different classes of compounds and plant extracts and by the use of chlorine and physicochemical methods (heat, UV light, pulsed electric fields, and high pressure), the synergistic antimicrobial effects of combinations of natural antimicrobials with medicinal antibiotics, and mechanisms of antimicrobial activities and resistant effects. Possible areas for future research are suggested. Plant-derived and other safe natural antimicrobial compounds have the potential to control the prevalence of both susceptible and resistant pathogens in various environments. The collated information and suggested research will hopefully contribute to a better understanding of approaches that could be used to minimize the presence of resistant pathogens in animal feed and human food, thus reducing adverse effects, improving microbial food safety, and helping to prevent or treat animal and human infections.

  12. The assessment of efficacy of porcine reproductive respiratory syndrome virus inactivated vaccine based on the viral quantity and inactivation methods

    Directory of Open Access Journals (Sweden)

    Lee Byeongchun

    2011-06-01

    Full Text Available Abstract Background There have been many efforts to develop efficient vaccines for the control of porcine reproductive and respiratory syndrome virus (PRRSV. Although inactivated PRRSV vaccines are preferred for their safety, they are weak at inducing humoral immune responses and controlling field PRRSV infection, especially when heterologous viruses are involved. Results In all groups, the sample to positive (S/P ratio of IDEXX ELISA and the virus neutralization (VN titer remained negative until challenge. While viremia did not reduce in the vaccinated groups, the IDEXX-ELISA-specific immunoglobulin G increased more rapidly and to significantly greater levels 7 days after the challenge in all the vaccinated groups compared to the non-vaccinated groups (p 6 PFU/mL PRRSV vaccine-inoculated and binary ethylenimine (BEI-inactivated groups 22 days after challenge (p Conclusions The inactivated vaccine failed to show the humoral immunity, but it showed different immune response after the challenge compared to mock group. Although the 106 PFU/mL-vaccinated and BEI-inactivated groups showed significantly greater VN titers 22 days after challenge, all the groups were already negative for viremia.

  13. Cytolytic T lymphocyte responses to metabolically inactivated stimulator cells. I. Metabolic inactivation impairs both CD and LD antigen signals

    International Nuclear Information System (INIS)

    Kelso, A.; Boyle, W.

    1982-01-01

    The effects of metabolic inactivation of spleen cells on antigen presentation to precursors of alloreactive cytolytic T lymphocytes (T/sub c/) were examined. By serological methods, populations inactivated by ultraviolet irradiation, glutaraldehyde fixation or plasma membrane isolation were found to retain normal levels of H-2K/D and Ia antigens. However, comparison of the antigen doses required to stimulate secondary T/sub c/ responses in mixed leukocyte culture showed that the inactivated preparations were approximately 10-fold less immunogenic than X-irradiated spleen cells. Their total inability to stimulate primary cytolytic responses pointed to at least a 100-fold impairment of immunogenicity for unprimed T/sub c/ precursors in the case of uv-irradiated and glutaraldehyde-treated stimulator cells, and at least a 10-fold impairment for membrane fragments. Experiments showing that the capacity of cell monolayers to absorb precursor T/sub c/ from unprimed spleen populations was reduced following uv-irradiation or glutaraldehyde treatment provided direct evidence that this loss of immunogenicity was due in part to suboptimal antigen presentation to precursor T/sub c/. It is concluded that, in addition to the traditional view that these treatments damage the ''LD'' signal to helper T lymphocytes, metabolic inactivation also impairs recognition of ''CD'' determinants by precursor T/sub c/

  14. Host pathogen relations: exploring animal models for fungal pathogens.

    Science.gov (United States)

    Harwood, Catherine G; Rao, Reeta P

    2014-06-30

    Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

  15. Host Pathogen Relations: Exploring Animal Models for Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    Catherine G. Harwood

    2014-06-01

    Full Text Available Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

  16. Antibacterial effects of hydrogen peroxide and silver composition on selected pathogenic enterobacteriaceae

    Directory of Open Access Journals (Sweden)

    Mojtaba Davoudi

    2012-01-01

    Full Text Available Aims: Antibacterial effects of hydrogen peroxide and silver composition on selected pathogenic enterobacteriaceae was investigated in this study. Materials and Methods: The efficacy of 30 ppb silver in 0.3% hydrogen peroxide solution for inactivation of selected Enterobacteriaceae, including Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae was assessed for 72 hours in a designated nutrient broth medium and steel surface. The bactericidal growth ability was determined for each bacterium genus by the conventional colony count method and turbidimetry via an optical density (OD assay at 450 nm in a time interval of 24 hours. Results: Suspensions of K.pneumoniae, and P.mirabilis showed a significant OD reduction at three 24-hour intervals (CI = 0.95; P < 0.05, for both, along with blocked growth in a designated broth medium during 24 to 48 hours of exposure. The disinfectant was also significantly efficient for inactivating of the mentioned bacteria on steel surfaces after a 15-minute time exposure (CI = 0.95; P < 0.05. For E.coli, the OD decreased slightly during the initial exposure time, but increased after 24 hours. Viable E.coli cells were proved by colonies grown on the plate. A qualitative surface decontamination test showed that three pathogenic bacteria were inactivated significantly after disinfectant exposure (CI = 0.95, P < 0.05. Conclusions: In conclusion, a combination of hydrogen peroxide and silver ions was proposed as a strong disinfecting agent both in suspensions and on the surfaces against these three important human pathogens.

  17. Microbial inactivation and shelf life extension of Korean traditional prepared meals by irradiation

    International Nuclear Information System (INIS)

    Jo, C.

    2009-01-01

    The effects of gamma irradiation on microbial inactivation and shelf life extension of Korean traditional prepared meals, including bulgogi and its sauce, marinated beef rib and Kimbab, were investigated. Raw vegetables, fruits and soy sauce used for making bulgogi sauce were highly contaminated and most of them with Bacillus spp. and coliform bacteria at the initial stage. Irradiation at 10 kGy eliminated coliforms in the bulgogi sauce and no growth was found during the 4 weeks of storage at 20 deg. C. The sensory evaluation of bulgogi and its sauce showed that the colour of irradiated samples was better than that of non-irradiated controls or heat treated samples. The total bacteria count and coliform of marinated beef ribs were 5.68 and 3.68 in CFU/g, respectively. The effect of irradiation on the growth of the four test microorganisms inoculated (about 106-107 CFU/g) into the marinated beef ribs were dose dependent (a higher dose produced a greater reduction). All the four pathogens inoculated on marinated beef ribs were eliminated at 4 kGy. The D 10 values of Bacillus cereus, Staphylococcus aureus, Salmonella typhimurium and Escherichia coli on inoculated marinated beef ribs were 0.66 ± 0.01, 0.59 ± 0.05, 0.64 ± 0.02 and 0.54 ± 0.01 kGy, respectively. Of these, E. coli was the most radiation sensitive in the raw marinated beef ribs. The number of the four pathogens inoculated into Kimbab decreased by 2-3 ln CFU/g for every 1 kGy increment and were not detected after 3 kGy. The D 10 values of pathogens inoculated into the Kimbab were in the range 0.31-0.44 kGy. This study indicated that irradiation is effective in ensuring the safety of Korean traditional prepared meals, including bulgogi sauce, bulgogi, marinated beef ribs and Kimbab with acceptable sensory quality. For Kimchijumeokbab, viable cells of the four pathogens inoculated increased slightly after abusive storage condition (20 deg. C), although under commercial condition (4 deg. C), and after 2

  18. Inactivation kinetics of Vibrio vulnificus in phosphate-buffered saline at different freezing and storage temperatures and times.

    Science.gov (United States)

    Seminario, Diana M; Balaban, Murat O; Rodrick, Gary

    2011-03-01

    Vibrio vulnificus (Vv) is a pathogen that can be found in raw oysters. Freezing can reduce Vv and increase the shelf life of oysters. The objective of this study was to develop predictive inactivation kinetic models for pure cultures of Vv at different frozen storage temperatures and times. Vv was diluted in phosphate-buffered saline (PBS) to obtain about 10(7) CFU/mL. Samples were frozen at -10, -35, and -80 °C (different freezing rates), and stored at different temperatures. Survival of Vv was followed after freezing and storage at -10 °C (0, 3, 6, and 9 d) and at -35 and -80 °C (every week for 6 wk). For every treatment, time-temperature data was obtained using thermocouples in blank vials. Predictive models were developed using first-order, Weibull and Peleg inactivation kinetics. Different freezing temperatures did not significantly (α = 0.05) affect survival of Vv immediately after freezing. The combined effect of freezing and 1 wk frozen storage resulted in 1.5, 2.6, and 4.9 log10 reductions for samples stored at -80, -35, and -10 °C, respectively. Storage temperature was the critical parameter in survival of Vv. A modified Weibull model successfully predicted Vv survival during frozen storage: log10 Nt = log 10No - 1.22 - ([t/10{-1.163-0.0466T}][0.00025T(2) + 0.049325]). N(o) and N(t) are initial and time t (d) survival counts, T is frozen storage temperature, Celsius degree. Vibrio vulnificus can be inactivated by freezing. Models to predict survival of V. vulnificus at different freezing temperatures and times were developed. This is the first step towards the prediction of V. vulnificus related safety of frozen oysters.

  19. Inactivation of Escherichia coli O157:H7 on stainless steel upon exposure to Paenibacillus polymyxa biofilms.

    Science.gov (United States)

    Kim, Seonhwa; Bang, Jihyun; Kim, Hoikyung; Beuchat, Larry R; Ryu, Jee-Hoon

    2013-11-01

    We investigated the potential use of biofilm formed by a competitive-exclusion (CE) microorganism to inactivate Escherichia coli O157:H7 on a stainless steel surface. Five microorganisms showing inhibitory activities against E. coli O157:H7 were isolated from vegetable seeds and sprouts. The microorganism with the greatest antimicrobial activity was identified as Paenibacillus polymyxa (strain T5). In tryptic soy broth (TSB), strain T5 reached a higher population at 25 °C than at 12 or 37 °C without losing inhibitory activity against E. coli O157:H7. When P. polymyxa (6 log CFU/mL) was co-cultured with E. coli O157:H7 (2, 3, 4, or 5 log CFU/mL) in TSB at 25 °C, the number of E. coli O157:H7 decreased significantly within 24h. P. polymyxa formed a biofilm on stainless steel coupons (SSCs) in TSB at 25 °C within 24h, and cells in biofilms, compared to attached cells without biofilm formation, showed significantly increased resistance to a dry environment (43% relative humidity [RH]). With the exception of an inoculum of 4 log CFU/coupon at 100% RH, upon exposure to biofilm formed by P. polymyxa on SSCs, populations of E. coli O157:H7 (2, 4, or 6 log CFU/coupon) were significantly reduced within 48 h. Most notably, when E. coli O157:H7 at 2 log CFU/coupon was applied to SSCs on which P. polymyxa biofilm had formed, it was inactivated within 1h, regardless of RH. These results will be useful when developing strategies using biofilms produced by competitive exclusion microorganisms to inactivate foodborne pathogens in food processing environments. © 2013.

  20. Theoretical Analysis of the Influence of Process Parameters on Pathogen Transport and Fate in a Recreational Beach

    Science.gov (United States)

    Liu, L.; Fu, X.

    2010-12-01

    The US has very long shorelines (95,471 miles) contributing remarkable yearly revenue to the country by providing numerous recreational beaches. The beaches of both inland lakes and marine regions must be closed when the level of waterborne pathogens indicated by fecal indicator bacteria (FIB) including total coliform (TC), fecal coli form (FC, or Escherichia coli, E. coli) and Enterococcus exceed microbial water quality standards. Beach closures are of mounting concern to beach managers and the public due to the increasing risk to human health from waterborne pathogens. Monitoring FIB with laboratory analysis usually takes at least 18 hours during which beach goers may have been unintentionally exposed to the contaminated water. Therefore a water quality model to quickly and precisely forecast FIB has been a very effective tool for beach management to help beach managers in making decisions if beaches are safe enough to open to the public. The fate and transport of pathogens in the surf-zone of a beach area is a complex process involving various factors of hydrodynamics, hydrology, chemistry, microbiology. These factors including dispersion coefficient, wind velocity, particle settling velocity, fraction of bacteria attached, solar insolation, discharges to the beach, geometry of the beach, etc, are the essential components for a mechanistic model to describe the inactivation of FIB. To better understand the importance of these factors and their roles in impacting inactivation, transport and removal of FIB is extremely important to enhance the effectiveness and preciseness of a predictive model. The aim of this paper is to report the sensitivity analysis results of these factors in the surf zone of a creational beach using a verified water quality model system. The relative importance of these parameters is being ranked. For instance, the current sensitivity analysis shows that sunlight insolation has greater impact on pathogen inactivation than water temperature

  1. THE ANTIGENIC POTENCY OF EPIDEMIC INFLUENZA VIRUS FOLLOWING INACTIVATION BY ULTRAVIOLET RADIATION

    Science.gov (United States)

    Salk, Jonas E.; Lavin, G. I.; Francis, Thomas

    1940-01-01

    A study of the antigenic potency of influenza virus inactivated by ultraviolet radiation has been made. Virus so inactivated is still capable of functioning as an immunizing agent when given to mice by the intraperitoneal route. In high concentrations inactivated virus appears to be nearly as effective as active virus but when quantitative comparisons of the immunity induced by different dilutions are made, it is seen that a hundredfold loss in immunizing capacity occurs during inactivation. Virus in suspensions prepared from the lungs of infected mice is inactivated more rapidly than virus in tissue culture medium. A standard for the comparison of vaccines of epidemic influenza virus is proposed. PMID:19871057

  2. Removal of Foodborne Pathogen Biofilms by Acidic Electrolyzed Water

    Directory of Open Access Journals (Sweden)

    Qiao Han

    2017-06-01

    Full Text Available Biofilms, which are complex microbial communities embedded in the protective extracellular polymeric substances (EPS, are difficult to remove in food production facilities. In this study, the use of acidic electrolyzed water (AEW to remove foodborne pathogen biofilms was evaluated. We used a green fluorescent protein-tagged Escherichia coli for monitoring the efficiency of AEW for removing biofilms, where under the optimal treatment conditions, the fluorescent signal of cells in the biofilm disappeared rapidly and the population of biofilm cells was reduced by more than 67%. Additionally, AEW triggered EPS disruption, as indicated by the deformation of the carbohydrate C-O-C bond and deformation of the aromatic rings in the amino acids tyrosine and phenylalanine. These deformations were identified by EPS chemical analysis and Raman spectroscopic analysis. Scanning electron microscopy (SEM images confirmed that the breakup and detachment of biofilm were enhanced after AEW treatment. Further, AEW also eradicated biofilms formed by both Gram-negative bacteria (Vibrio parahaemolyticus and Gram-positive bacteria (Listeria monocytogenes and was observed to inactivate the detached cells which are a potential source of secondary pollution. This study demonstrates that AEW could be a reliable foodborne pathogen biofilm disrupter and an eco-friendly alternative to sanitizers traditionally used in the food industry.

  3. Tropism and pathogenicity of rickettsiae

    Directory of Open Access Journals (Sweden)

    Tsuneo eUchiyama

    2012-06-01

    Full Text Available Rickettsiae are obligate intracellular parasitic bacteria that cause febrile exanthematous illnesses such as Rocky Mountain spotted fever, Mediterranean spotted fever, epidemic and murine typhus, etc. Although the vector ranges of each Rickettsia species are rather restricted; i.e., ticks belonging to Arachnida and lice and fleas belonging to Insecta usually act as vectors for spotted fever group and typhus group rickettsiae, respectively, it would be interesting to elucidate the mechanisms controlling the vector tropism of rickettsiae. This review discusses the factors determining the vector tropism of rickettsiae. In brief, the vector tropism of rickettsiae species is basically consistent with their tropism towards cultured tick and insect cells. The mechanisms responsible for rickettsiae pathogenicity are also described. Recently, genomic analyses of rickettsiae have revealed that they possess several genes that are homologous to those affecting the pathogenicity of other bacteria. Analyses comparing the genomes of pathogenic and nonpathogenic strains of rickettsiae have detected many factors that are related to rickettsial pathogenicity. It is also known that a reduction in the rickettsial genome has occurred during the course of its evolution. Interestingly, Rickettsia species with small genomes, such as Rickettsia prowazekii, are more pathogenic to humans than those with larger genomes. This review also examines the growth kinetics of pathogenic and nonpathogenic species of spotted fever group rickettsiae in mammalian cells. The growth of nonpathogenic species is restricted in these cells, which is mediated, at least in part, by autophagy. The superinfection of nonpathogenic rickettsiae-infected cells with pathogenic rickettsiae results in an elevated yield of the nonpathogenic rickettsiae and the growth of the pathogenic rickettsiae. Autophagy is restricted in these cells. These results are discussed in this review.

  4. Pathogen avoidance by insect predators

    OpenAIRE

    Meyling, Nicolai V.; Ormond, Emma; Roy, Helen E.; Pell, Judith K.

    2008-01-01

    Insects can detect cues related to the risk of attack by their natural enemies. Pathogens are among the natural enemies of insects and entomopathogenic fungi attack a wide array of host species. Evidence documents that social insects in particular have adapted behavioural mechanisms to avoid infection by fungal pathogens. These mechanisms are referred to as 'behavioural resistance'. However, there is little evidence for similar adaptations in non-social insects. We have conducted experime...

  5. Antibiotic Resistance in Foodborne Pathogens

    OpenAIRE

    Walsh, Ciara; Duffy, Geraldine

    2013-01-01

    Wide-spread antibiotic resistance among bacterial pathogens is now a serious public health issue and multi-antibiotic resistance has been reported in many foodborne pathogens including Salmonella and E. coli. A study to determine antibiotic resistance profiles of a range of Salmonella and Verocytotoxigenic E.coli (VTEC) isolated from Irish foods revealed significant levels of antibiotic resistance in the strains. S. typhimurium DT104 were multiantibiotic resistant with 97% resistant to 7 anti...

  6. Molecular detection of human bacterial pathogens

    National Research Council Canada - National Science Library

    Liu, Dongyou

    2011-01-01

    .... Molecular Detection of Human Bacterial Pathogens addresses this issue, with international scientists in respective bacterial pathogen research and diagnosis providing expert summaries on current...

  7. Modeling of human factor Va inactivation by activated protein C

    Directory of Open Access Journals (Sweden)

    Bravo Maria

    2012-05-01

    Full Text Available Abstract Background Because understanding of the inventory, connectivity and dynamics of the components characterizing the process of coagulation is relatively mature, it has become an attractive target for physiochemical modeling. Such models can potentially improve the design of therapeutics. The prothrombinase complex (composed of the protease factor (FXa and its cofactor FVa plays a central role in this network as the main producer of thrombin, which catalyses both the activation of platelets and the conversion of fibrinogen to fibrin, the main substances of a clot. A key negative feedback loop that prevents clot propagation beyond the site of injury is the thrombin-dependent generation of activated protein C (APC, an enzyme that inactivates FVa, thus neutralizing the prothrombinase complex. APC inactivation of FVa is complex, involving the production of partially active intermediates and “protection” of FVa from APC by both FXa and prothrombin. An empirically validated mathematical model of this process would be useful in advancing the predictive capacity of comprehensive models of coagulation. Results A model of human APC inactivation of prothrombinase was constructed in a stepwise fashion by analyzing time courses of FVa inactivation in empirical reaction systems with increasing number of interacting components and generating corresponding model constructs of each reaction system. Reaction mechanisms, rate constants and equilibrium constants informing these model constructs were initially derived from various research groups reporting on APC inactivation of FVa in isolation, or in the presence of FXa or prothrombin. Model predictions were assessed against empirical data measuring the appearance and disappearance of multiple FVa degradation intermediates as well as prothrombinase activity changes, with plasma proteins derived from multiple preparations. Our work integrates previously published findings and through the cooperative

  8. N-chlorotaurine, a long-lived oxidant produced by human leukocytes, inactivates Shiga toxin of enterohemorrhagic Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Christian Eitzinger

    Full Text Available N-chlorotaurine (NCT, the main representative of long-lived oxidants produced by granulocytes and monocytes, is known to exert broad-spectrum microbicidal activity. Here we show that NCT directly inactivates Shiga toxin 2 (Stx2, used as a model toxin secreted by enterohemorrhagic Escherichia coli (EHEC. Bacterial growth and Stx2 production were both inhibited by 2 mM NCT. The cytotoxic effect of Stx2 on Vero cells was removed by ≥5.5 mM NCT. Confocal microscopy and FACS analyses showed that the binding of Stx2 to human kidney glomerular endothelial cells was inhibited, and no NCT-treated Stx2 entered the cytosol. Mass spectrometry displayed oxidation of thio groups and aromatic amino acids of Stx2 by NCT. Therefore, long-lived oxidants may act as powerful tools of innate immunity against soluble virulence factors of pathogens. Moreover, inactivation of virulence factors may contribute to therapeutic success of NCT and novel analogs, which are in development as topical antiinfectives.

  9. Preparation of mucosal nanoparticles and polymer-based inactivated vaccine for Newcastle disease and H9N2 AI viruses

    Directory of Open Access Journals (Sweden)

    Heba M. El Naggar

    2017-02-01

    Full Text Available Aim: To develop a mucosal inactivated vaccines for Newcastle disease (ND and H9N2 viruses to protect against these viruses at sites of infections through mucosal immunity. Materials and Methods: In this study, we prepared two new formulations for mucosal bivalent inactivated vaccine formulations for Newcastle and Avian Influenza (H9N2 based on the use of nanoparticles and polymer adjuvants. The prepared vaccines were delivered via intranasal and spray routes of administration in specific pathogen-free chickens. Cell-mediated and humoral immune response was measured as well as challenge trial was carried out. In addition, ISA71 water in oil was also evaluated. Results: Our results showed that the use of spray route as vaccination delivery method of polymer and nanoparticles MontanideTM adjuvants revealed that it enhanced the cell mediated immune response as indicated by phagocytic activity, gamma interferon and interleukin 6 responses and induced protection against challenge with Newcastle and Avian Influenza (H9N2 viruses. Conclusion: The results of this study demonstrate the potentiality of polymer compared to nanoparticles adjuvantes when used via spray route. Mass application of such vaccines will add value to improve the vaccination strategies against ND virus and Avian influenza viruses.

  10. The Efficiency of UVC Radiation in the Inactivation of Listeria monocytogenes on Beef-Agar Food Models

    Directory of Open Access Journals (Sweden)

    Christian James

    2015-01-01

    Full Text Available The aim of this study is to evaluate the eff ect of meat content and surface smoothness on the deactivation of Listeria monocytogenes in beef-agar food models achieved by shortwave ultraviolet (UVC light. Food models with various meat contents were made using chopped beef slices and agar solution. Prepared models together with a Listeria selective agar (LSA plate and a slice of cooked beef were inoculated with L. monocytogenes and then exposed to UVC light. Population of Listeria reduced to below the level of detection on the LSA plates. As the content of beef in the beef-agar models increased, more L. monocytogenes cells survived. Survival was greatest on the treated cooked slice of beef. To bett er understand the effect of surface irregularities, a white light interferometer was used to analyse the surface smoothness of beef-agar media and LSA plates. No correlation was observed between the surface roughness of seven out of nine types of produced beef-agar media and the degree of inactivation resulting from UVC radiation at the given dose, whereas, less bacterial cells were killed as beef content of the food models increased. The findings of the current study show that the chemical composition of the treated sample also plays an important role in pathogen resistance and survival, meaning that two samples with similar surface irregularities but diff erent chemical composition might produce very diff erent inactivation results when exposed to UVC light.

  11. Preserved immunogenicity of an inactivated vaccine based on foot-and-mouth disease virus particles with improved stability.

    Science.gov (United States)

    Caridi, Flavia; Vázquez-Calvo, Ángela; Borrego, Belén; McCullough, Kenneth; Summerfield, Artur; Sobrino, Francisco; Martín-Acebes, Miguel A

    2017-05-01

    Foot-and-mouth disease virus (FMDV) is the etiological agent of a highly contagious disease that affects important livestock species. Vaccines based on inactivated FMDV virions provide a useful tool for the control of this pathogen. However, long term storage at 4°C (the temperature for vaccine storage) or ruptures of the cold chain, provoke the dissociation of virions, reducing the immunogenicity of the vaccine. An FMDV mutant carrying amino acid replacements VP1 N17D and VP2 H145Y isolated previously rendered virions with increased resistance to dissociation at 4°C. We have evaluated the immunogenicity in swine (a natural FMDV host) of a chemically inactivated vaccine based on this mutant. The presence of these amino acid substitutions did not compromise the immunological potential, including its ability to elicit neutralizing antibodies. These results support the feasibility of this kind of mutants with increased capsid stability as suitable viruses for producing improved FMDV vaccines. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Effects of irradiation and fumaric acid treatment on the inactivation of Listeria monocytogenes and Salmonella typhimurium inoculated on sliced ham

    Science.gov (United States)

    Song, Hyeon-Jeong; Lee, Ji-Hye; Song, Kyung Bin

    2011-11-01

    To examine the effects of fumaric acid and electron beam irradiation on the inactivation of foodborne pathogens in ready-to-eat meat products, sliced ham was inoculated with Listeria monocytogenes and Salmonella typhimurium. The inoculated ham slices were treated with 0.5% fumaric acid or electron beam irradiation at 2 kGy. Fumaric acid treatment reduced the populations of L. monocytogenes and S. typhimurium by approximately 1 log CFU/g compared to control populations. In contrast, electron beam irradiation decreased the populations of S. typhimurium and L. monocytogenes by 3.78 and 2.42 log CFU/g, respectively. These results suggest that electron beam irradiation is a better and appropriate technique for improving the microbial safety of sliced ham.

  13. Germination and Inactivation of Alicyclobacillus acidoterrestris Spores Induced by Moderate Hydrostatic Pressure.

    Science.gov (United States)

    Sokołowska, Barbara; Skapska, Sylwia; Fonberg-Broczek, Monika; Niezgoda, Jolanta; Porebska, Izabela; Dekowska, Agnieszka; Rzoska, Sylwester J

    2015-01-01

    Given the importance of spoilage caused by Alicyclobacillus acidoterrestris for the fruit juice industry, the objective of this work was to study the germination and inactivation of A. acidoterrestris spores induced by moderate hydrostatic pressure. Hydrostatic pressure treatment can induce the germination and inactivation of A. acidoterrestris spores. At low pH, spore germination of up to 3.59-3.75 log and inactivation of 1.85-2.04 log was observed in a low pressure window (200-300 MPa) applied at 50 degrees C for 20 min. Neutral pH suppressed inactivation, the number of spores inactivated at pH 7.0 was only 0.24-1.06 log. The pressurization temperature significantly affected spore germination and inactivation. The degree of germination in apple juice after pressurization for 30 min with 200 MPa at 20 degrees C was 2.04 log, with only 0.61 log of spores being inactivated, while at 70 degrees C spore germination was 5.94 log and inactivation 4.72 log. This temperature strongly stimulated germination and inactivation under higher (500 MPa) than lower (200 MPa) pressure. When the oscillatory mode was used, the degree of germination and inactivation was slightly higher than at continuous mode. The degree of germination and inactivation was inversely proportional to the soluble solids content and was lowest in concentrated apple juice.

  14. Photodynamic inactivation of conidia of the fungus Colletotrichum abscissum on Citrus sinensis plants with methylene blue under solar radiation.

    Science.gov (United States)

    Gonzales, Júlia C; Brancini, Guilherme T P; Rodrigues, Gabriela B; Silva-Junior, Geraldo José; Bachmann, Luciano; Wainwright, Mark; Braga, Gilberto Ú L

    2017-11-01

    Antimicrobial photodynamic treatment (APDT) is a promising light based approach to control diseases caused by plant-pathogenic fungi. In the present study, we evaluated the effects of APDT with the phenothiazinium photosensitizer methylene blue (MB) under solar radiation on the germination and viability of conidia of the pathogenic fungus Colletotricum abscissum (former Colletotrichum acutatum sensu lato). Experiments were performed both on petals and leaves of sweet orange (Citrus sinensis) in different seasons and weather conditions. Conidial suspensions were deposited on the leaves and petals surface, treated with the PS (25 or 50μM) and exposed to solar radiation for only 30min. The effects of APDT on conidia were evaluated by counting the colony forming units recovered from leaves and petals and by direct evaluating conidial germination on the surface of these plant organs after the treatment. To better understand the mechanistic of conidial photodynamic inactivation, the effect of APDT on the permeability of the conidial plasma membrane was assessed using the fluorescent probe propidium iodide (PI) together with flow cytometry and fluorescence microscopy. APDT with MB and solar exposure killed C. abscissum conidia and prevented their germination on both leaves and petals of citrus. Reduction of conidial viability was up to three orders of magnitude and a complete photodynamic inactivation was achieved in some of the treatments. APDT damaged the conidial plasma membrane and increased its permeability to PI. No damage to sweet orange flowers or leaves was observed after APDT. The demonstration of the efficacy of APDT on the plant host represents a further step towards the use o