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Sample records for inactivate food-borne pathogens

  1. Nonthermal Plasma Inactivation of Food-Borne Pathogens

    OpenAIRE

    Misra, N.; Tiwari, B.; Rahavarao, K.; Cullen, Patrick

    2011-01-01

    Non-thermal plasma (NTP) is electrically energized matter, composed of highly reactive species including gas molecules, charged particles in the form of positive ions, negative ions, free radicals, electrons and quanta of electromagnetic radiation (photons) at near-room temperature. NTP is an emerging nonthermal technology with potential applications for decontamination in the food industries. An upsurge in the research activities for plasma based inactivation of food borne pathogens is evide...

  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. 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)

  4. 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.

  5. Inactivation of food-borne spoilage and pathogenic micro-organisms on the surface of a photoactive polymer.

    Science.gov (United States)

    Zerdin, Katherine; Scully, Andrew D

    2010-01-01

    The photodynamic action of a novel photoactive polymer comprising covalently bound anthraquinone (AQ) moieties was evaluated after developing a methodology to reliably immobilize viable micro-organisms onto polymer film surfaces. The survival of Escherichia coli, Bacillus cereus (vegetative cells and spores), Fusarium oxysporum and Saccharomyces cerevisiae microbes inoculated on the surface of inert polymeric substrates was assessed to determine the effect of inoculum composition, drying rate and exposure to ultraviolet (UV-A) radiation. Their survival was highly dependent on microbial genus, with E. coli consistently displaying markedly shorter survival times than the other microbes, and B. cereus spores being the most resistant. Inoculation of the microbes onto the surface of the photoactive polymer films, followed by exposure to UV-A radiation, dramatically accelerated the inactivation of all microbial types studied compared with their survival on the surface of inert polymer substrates. Simultaneous exposure to both oxygen and UV-A radiation is required to affect cell survival, which is consistent with this effect most likely originating from the photoinduced production of singlet oxygen by the photoactive polymer. These results provide further compelling evidence that singlet oxygen produced exogenously by this photoactive polymeric substrate can successfully inactivate a broad spectrum of microbes on the substrate's surface. © 2010 The Authors. Journal Compilation. The American Society of Photobiology.

  6. Bacterial food-borne pathogens in Indian food

    International Nuclear Information System (INIS)

    Bandekar, J.R.

    2015-01-01

    Food technology and food processing techniques have made tremendous advances in preservation of food and ensuring safety of food by killing food-borne pathogens. In addition to old techniques such as pasteurization, canning, dehydration, fermentation and salting, a number of new techniques such as radiation processing, high pressure technology and pulsed electric field technology are being applied for preservation of food and to ensure food safety. Total Quality Management (TQM) concepts have been developed to take care of food safety from farm to table. Hazard Analysis at Critical Control Points (HACCP) is being applied for mass scale production of food to make food free from pathogens. Despite these advances, food-borne diseases have become one of the most widespread public health problems in the world. About two thirds of all the outbreaks are traced to microbial contaminated food. According to World Health Organization (WHO) estimates, food-borne and waterborne diarrhoeal diseases kill an estimated 2 million people annually, including many children. Food safety is a major concern not only for developing countries but also for the developed countries. A number of factors such as emergence of new food-borne pathogens, development of drug resistance in pathogens, changing life style, globalization of the food supply etc. are responsible for the continuous persistence of food-borne diseases. The food-borne disease outbreaks due to E. coli O157:H7, Listeria monocytogenes, Salmonella and Campylobacter, are responsible for recall of many foods resulting in heavy losses to food industry. Due to consumer demand, a number of Ready-To-Eat (RTE) minimally processed foods are increasingly marketed; however, there is increased risk of foodborne diseases with these products. Food Technology Division of Bhabha Atomic Research Centre, Mumbai, has been working on food-borne bacterial pathogens particularly Salmonella, Campylobacter, Listeria monocytogenes, Vibrio and Aeromonasf

  7. Microbial Flora and Food Borne Pathogens on Minced Meat and ...

    African Journals Online (AJOL)

    BACKGROUND: Food-borne pathogens are the leading cause of illness and death in developing countries. Changes in eating habits, mass catering, unsafe food storage conditions and poor hygiene practices are major contributing factors to food associated illnesses. In Ethiopia, the widespread habit of raw beef ...

  8. Synergetic effect of combined fumaric acid and slightly acidic electrolysed water on the inactivation of food-borne pathogens and extending the shelf life of fresh beef.

    Science.gov (United States)

    Tango, C-N; Mansur, A-R; Kim, G-H; Oh, D-H

    2014-12-01

    To evaluate synergetic effect of slight acidic electrolysed water (SAEW) and fumaric acid (FA) on inactivation of total viable count (TVC) and Staphylococcus aureus, Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella Typhimurium in fresh beef and to study shelf life and sensory quality of beef. Inoculated samples was dipped for 1, 3 and 5 min and immersed at 25, 40 and 60°C in SAEW, strong acidic electrolysed water (StAEW) and SAWE + FA. Treated meat was air-packaged and stored at 4 or 10°C. During storage, sampling was performed at 2-day intervals for microbiological and sensory changes. TVC was decontaminated at 40°C for 3 min by more than 3·70 log CFU g(-1) , and examined pathogens were reduced by more than 2·60 log CFU g(-1) with SAEW + FA treatment. This treatment prolonged shelf life of beef meat up to 9 and 7 days when stored at 4 and 10°C, respectively. The combined treatment of SAEW + FA showed greater bactericidal effect and prolonged shelf life compared with individual treatments. Combined treatment of SAEW and FA can be a suitable hurdle technology reducing bacteria in fresh beef, substantially enhancing their microbial safety and decreasing pathogens growth during storage. © 2014 The Society for Applied Microbiology.

  9. DNA microarray technique for detecting food-borne pathogens

    Directory of Open Access Journals (Sweden)

    Xing GAO

    2012-08-01

    Full Text Available Objective To study the application of DNA microarray technique for screening and identifying multiple food-borne pathogens. Methods The oligonucleotide probes were designed by Clustal X and Oligo 6.0 at the conserved regions of specific genes of multiple food-borne pathogens, and then were validated by bioinformatic analyses. The 5' end of each probe was modified by amino-group and 10 Poly-T, and the optimized probes were synthesized and spotted on aldehyde-coated slides. The bacteria DNA template incubated with Klenow enzyme was amplified by arbitrarily primed PCR, and PCR products incorporated into Aminoallyl-dUTP were coupled with fluorescent dye. After hybridization of the purified PCR products with DNA microarray, the hybridization image and fluorescence intensity analysis was acquired by ScanArray and GenePix Pro 5.1 software. A series of detection conditions such as arbitrarily primed PCR and microarray hybridization were optimized. The specificity of this approach was evaluated by 16 different bacteria DNA, and the sensitivity and reproducibility were verified by 4 food-borne pathogens DNA. The samples of multiple bacteria DNA and simulated water samples of Shigella dysenteriae were detected. Results Nine different food-borne bacteria were successfully discriminated under the same condition. The sensitivity of genomic DNA was 102 -103pg/ μl, and the coefficient of variation (CV of the reproducibility of assay was less than 15%. The corresponding specific hybridization maps of the multiple bacteria DNA samples were obtained, and the detection limit of simulated water sample of Shigella dysenteriae was 3.54×105cfu/ml. Conclusions The DNA microarray detection system based on arbitrarily primed PCR can be employed for effective detection of multiple food-borne pathogens, and this assay may offer a new method for high-throughput platform for detecting bacteria.

  10. Antimicrobial Impacts of Essential Oils on Food Borne-Pathogens.

    Science.gov (United States)

    Ozogul, Yesim; Kuley, Esmeray; Ucar, Yilmaz; Ozogul, Fatih

    2015-01-01

    The antimicrobial activity of twelve essential oil (pine oil, eucalyptus, thyme, sage tea, lavender, orange, laurel, lemon, myrtle, lemon, rosemary and juniper) was tested by a disc diffusion method against food borne pathogens (Escherichia coli, Salmonella paratyphi A, Klebsiella pneumoniae, Yersinia enterocolitica, Pseudomonas aeruginosa, Aeromonas hydrophila, Campylobacter jejuni, Enterococcus faecalis, Staphylococcus aureus). The major components in essential oils were monoterpenes hydrocarbons, α-pinene, limonene; monoterpene phenol, carvacrol and oxygenated monoterpenes, camphor, 1,8-cineole, eucalyptol, linalool and linalyl acetate. Although the antimicrobial effect of essential oils varied depending on the chemical composition of the essential oils and specific microorganism tested, majority of the oils exhibited antibacterial activity against one or more strains. The essential oil with the lowest inhibition zones was juniper with the values varied from 1.5 to 6 mm. However, the components of essential oil of thyme and pine oil are highly active against food borne pathogen, generating the largest inhibition zones for both gram negative and positive bacteria (5.25-28.25 mm vs. 12.5-30 mm inhibition zones). These results indicate the possible use of the essential oils on food system as antimicrobial agents against food-borne pathogen. The article also offers some promising patents on applications of essential oils on food industry as antimicrobial agent.

  11. Enteroaggregative Escherichia coli: An Emerging Enteric Food Borne Pathogen

    Directory of Open Access Journals (Sweden)

    P. Kaur

    2010-01-01

    Full Text Available Enteroaggregative Escherichia coli (EAEC are quite heterogeneous category of an emerging enteric pathogen associated with cases of acute or persistent diarrhea worldwide in children and adults, and over the past decade has received increasing attention as a cause of watery diarrhea, which is often persistent. EAEC infection is an important cause of diarrhea in outbreak and non-outbreak settings in developing and developed countries. Recently, EAEC has been implicated in the development of irritable bowel syndrome, but this remains to be confirmed. EAEC is defined as a diarrheal pathogen based on its characteristic aggregative adherence (AA to HEp-2 cells in culture and its biofilm formation on the intestinal mucosa with a “stacked-brick” adherence phenotype, which is related to the presence of a 60 MDa plasmid (pAA. At the molecular level, strains demonstrating the aggregative phenotype are quite heterogeneous; several virulence factors are detected by polymerase chain reaction; however, none exhibited 100% specificity. Although several studies have identified specific virulence factor(s unique to EAEC, the mechanism by which EAEC exerts its pathogenesis is, thus, far unknown. The present review updates the current knowledge on the epidemiology, chronic complications, detection, virulence factors, and treatment of EAEC, an emerging enteric food borne pathogen.

  12. ANTIBACTERIAL ACTIVITY OF GINGER OIL AGAINST FOOD BORN PATHOGENS

    International Nuclear Information System (INIS)

    TAHA, S.M.A.

    2008-01-01

    This study was carried out to investigate the antibacterial activity of ginger oil against Food Born pathogens and the effect of heating, microwave heating and gamma irradiation on microbiological quality and antibacterial activity of ginger oil. Growth and survival of A. hydrophila and L. monocytogenes in broth media and carrot juice with different concentrations of ginger oil was also studied. Gram-negative bacteria were more resistant than gram-positive bacteria. Heating at 80 0 C for 10 min did not change the antibacterial activity of ginger oil, whereas heating at 100 0 C for 5 min and autoclaving at 121 0 C for 15 min caused slight reduction in antibacterial activity in most microorganisms tested. Heating by microwave of ginger oil destroyed its antibacterial activity against B. cereus although it still works against other microorganisms tested. The dose 6 kGy caused slight reduction in antibacterial activity of ginger oil, whereas the dose 10 kGy caused markedly reduction in antibacterial activity of ginger oil against most microorganisms tested. Ginger oil was more effective on L. monocytogenes as compared with its effect on A. hydrophila in tryptone soya broth at 4 0 C or 25 0 C. Supplementation of ginger oil with carrot juice was more effective on A. hydrophila and L. monocytogenes than in tryptone soya broth and this effect was increased with increasing the time of incubation and the concentration of ginger oil. These results support the notion that plant essential oils may have an important role as pharmaceuticals and food preservatives

  13. Biocontrol and Rapid Detection of Food-Borne Pathogens Using Bacteriophages and Endolysins

    Science.gov (United States)

    Bai, Jaewoo; Kim, You-Tae; Ryu, Sangryeol; Lee, Ju-Hoon

    2016-01-01

    Bacteriophages have been suggested as natural food preservatives as well as rapid detection materials for food-borne pathogens in various foods. Since Listeria monocytogenes-targeting phage cocktail (ListShield) was approved for applications in foods, numerous phages have been screened and experimentally characterized for phage applications in foods. A single phage and phage cocktail treatments to various foods contaminated with food-borne pathogens including E. coli O157:H7, Salmonella enterica, Campylobacter jejuni, Listeria monocytogenes, Staphylococcus aureus, Cronobacter sakazakii, and Vibrio spp. revealed that they have great potential to control various food-borne pathogens and may be alternative for conventional food preservatives. In addition, phage-derived endolysins with high host specificity and host lysis activities may be preferred to food applications rather than phages. For rapid detection of food-borne pathogens, cell-wall binding domains (CBDs) from endolysins have been suggested due to their high host-specific binding. Fluorescence-tagged CBDs have been successfully evaluated and suggested to be alternative materials of expensive antibodies for various detection applications. Most recently, reporter phage systems have been developed and tested to confirm their usability and accuracy for specific detection. These systems revealed some advantages like rapid detection of only viable pathogenic cells without interference by food components in a very short reaction time, suggesting that these systems may be suitable for monitoring of pathogens in foods. Consequently, phage is the next-generation biocontrol agent as well as rapid detection tool to confirm and even identify the food-borne pathogens present in various foods. PMID:27092128

  14. Biocontrol and Rapid Detection of Food-borne Pathogens Using Bacteriophages and Endolysins

    Directory of Open Access Journals (Sweden)

    Jaewoo eBai

    2016-04-01

    Full Text Available Bacteriophages have been suggested as natural food preservatives as well as rapid detection materials for food-borne pathogens in various foods. Since Listeria monocytogenes-targeting phage cocktail (ListShield was approved for applications in foods, numerous phages have been screened and experimentally characterized for phage applications in foods. A single phage and phage cocktail treatments to various foods contaminated with food-borne pathogens including E. coli O157:H7, Salmonella enterica, Campylobacter jejuni, Listeria monocytogenes, Staphylococcus aureus, Cronobacter sakazakii, and Vibrio spp. revealed that they have great potential to control various food-borne pathogens and may be alternative for conventional food preservatives. In addition, phage-derived endolysins with high host specificity and host lysis activities may be preferred to food applications rather than phages. For rapid detection of food-borne pathogens, cell-wall binding domains (CBDs from endolysins have been suggested due to their high host-specific binding. Fluorescence-tagged CBDs have been successfully evaluated and suggested to be alternative materials of expensive antibodies for various detection applications. Most recently, reporter phage systems have been developed and tested to confirm their usability and accuracy for specific detection. These systems revealed some advantages like rapid detection of only viable pathogenic cells without interference by food components in a very short reaction time, suggesting that these systems may be suitable for monitoring of pathogens in foods. Consequently, phage is the next-generation biocontrol agent as well as rapid detection tool to confirm and even identify the food-borne pathogens present in various foods.

  15. Advanced molecular diagnostic techniques for detection of food-borne pathogens: Current applications and future challenges.

    Science.gov (United States)

    Umesha, S; Manukumar, H M

    2018-01-02

    The elimination of disease-causing microbes from the food supply is a primary goal and this review deals with the overall techniques available for detection of food-borne pathogens. Now-a-days conventional methods are replaced by advanced methods like Biosensors, Nucleic Acid-based Tests (NAT), and different PCR-based techniques used in molecular biology to identify specific pathogens. Bacillus cereus, Staphylococcus aureus, Proteus vulgaris, Escherichia coli, Campylobacter, Listeria monocytogenes, Salmonella spp., Aspergillus spp., Fusarium spp., Penicillium spp., and pathogens are detected in contaminated food items that cause always diseases in human in any one or the other way. Identification of food-borne pathogens in a short period of time is still a challenge to the scientific field in general and food technology in particular. The low level of food contamination by major pathogens requires specific sensitive detection platforms and the present area of hot research looking forward to new nanomolecular techniques for nanomaterials, make them suitable for the development of assays with high sensitivity, response time, and portability. With the sound of these, we attempt to highlight a comprehensive overview about food-borne pathogen detection by rapid, sensitive, accurate, and cost affordable in situ analytical methods from conventional methods to recent molecular approaches for advanced food and microbiology research.

  16. Interaction between Food-borne Pathogens (Campylobacter jejuni, Salmonella Typhimurium and Listeria monocytogenes) and a Common Soil Flagellate (Cercomonas sp.)

    DEFF Research Database (Denmark)

    Bui, Thanh Xuan; Wolff, Anders; Madsen, Mogens

    2012-01-01

    Free-living protozoa may harbor, protect, and disperse bacteria, including those ingested and passed in viable form in feces. The flagellates are very important predators on bacteria in soil, but their role in the survival of food-borne pathogens associated with fruits and vegetables is not well....... The results of this study suggest that Cercomonas sp. and perhaps other soil flagellates may play a role for the survival of food-borne pathogens on plant surfaces and in soil....

  17. Aerosolization as novel sanitizer delivery system to reduce food-borne pathogens.

    Science.gov (United States)

    Oh, S-W; Gray, P M; Dougherty, R H; Kang, D-H

    2005-01-01

    As a preliminary experiment on new sanitizer delivery tools, the efficacy of aerosolized sanitizer on food-borne pathogens was investigated in larger model chamber system. Peroxyacetic acid and hydrogen peroxide were aerosolized in a model system against artificially inoculated target micro-organisms on laboratory media. Cultures of four different food-borne pathogens were inoculated and affixed onto three different heights (bottom, wall and ceiling), and three different orientations (face-down, vertical and face-down) inside a commercial semi-trailer cabinet (14.6 x 2.6 x 2.8 m). Sanitizer was aerosolized into 2 microm droplet size fog and treated for 1 h at ambient temperature. Populations of Bacillus cereus, Listeria innocua, Staphylococcus aureus, and Salmonella typhimurium were reduced by an average of 3.09, 7.69, 6.93 and 8.18 log units per plate respectively. Interestingly, L. innocua, Staph. aureus, and Salm. typhimurium showed statistically not different (P >/= 0.05) reduction patterns relative to height and orientation that were never expected in a spraying system. Aerosolized sanitizers diffuse like gaseous sanitizers. Aerosolization has great potential for use in commercial applications.

  18. Silver Nanoparticles Synthesized Using Wild Mushroom Show Potential Antimicrobial Activities against Food Borne Pathogens

    Directory of Open Access Journals (Sweden)

    Yugal Kishore Mohanta

    2018-03-01

    Full Text Available The present study demonstrates an economical and eco-friendly method for the synthesis of silver nanoparticles (AgNPs using the wild mushroom Ganoderma sessiliforme. The synthesis of AgNPs was confirmed and the products characterized by UV-visible spectroscopy, dynamic light scattering spectroscopy and X-ray diffraction analysis. Furthermore, Fourier transform infrared spectroscopy (ATR-FTIR analysis was performed to identify the viable biomolecules involved in the capping and active stabilization of AgNPs. Moreover, the average sizes and morphologies of AgNPs were analyzed by field emission scanning electron microscopy (FE-SEM. The potential impacts of AgNPs on food safety and control were evaluated by the antimicrobial activity of the synthesized AgNPs against common food-borne bacteria, namely, Escherichia coli, Bacillus subtilis, Streptococcus faecalis, Listeria innocua and Micrococcus luteus. The results of this study revealed that the synthesized AgNPs can be used to control the growth of food-borne pathogens and have potential application in the food packaging industry. Moreover, the AgNPs were evaluated for antioxidant activity (DPPH, for biocompatibility (L-929, normal fibroblast cells, and for cytotoxic effects on human breast adenosarcoma cells (MCF-7 & MDA-MB231 to highlight their potential for use in a variety of bio-applications.

  19. Methicillin-resistant Staphylococcus aureus: a controversial food-borne pathogen.

    Science.gov (United States)

    Sergelidis, D; Angelidis, A S

    2017-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of severe healthcare-associated (HA) infections. Although during the last decade the incidence of HA invasive infections has dropped, the incidence of community-associated MRSA (CA-MRSA) infections has risen among the general population. Moreover, CA-MRSA, livestock-associated MRSA (LA-MRSA) and HA-MRSA (HA-MRSA) can be found in foods intended for human consumption. Several studies from different geographical areas have reported the presence of enterotoxin genes in several MRSA food isolates. Molecular typing studies have revealed genetic relatedness of these enterotoxigenic isolates with isolates incriminated in human infections. The contamination sources for foods, especially animal-origin foods, may be livestock as well as humans involved in animal husbandry and food-processing. Under favourable environmental conditions for growth and enterotoxin production, enterotoxigenic S. aureus isolates present in foods can cause staphylococcal food poisoning (SFP), irrespective of the contamination origin. Owing to the typically moderate clinical manifestations of SFP, the S. aureus strains responsible for SFP (cases or outbreaks) are frequently either not identified or not further characterized. Antimicrobial susceptibility testing is rarely performed, because administration of antimicrobial therapy is not required in the vast majority of cases. Staphylococcal food poisoning is the result of consumption of foods with preformed enterotoxins. Hence, similar to methicillin-sensitive enterotoxigenic S. aureus, enterotoxigenic MRSA can also act as food-borne pathogens upon favourable conditions for growth and enterotoxin production. The severity of the intoxication is not related to the antimicrobial resistance profile of the causative S. aureus strain and therefore MRSA food-borne outbreaks are not expected to be more severe. This review evaluates the potential of methicillin-resistant Staphylococcus

  20. Comparison of Three Different DNA Extraction Methods for Linguatula serrata as a Food Born Pathogen

    Directory of Open Access Journals (Sweden)

    Gilda ESLAMI

    2017-06-01

    Full Text Available Background: One of the most important items in molecular characterization of food-borne pathogens is high quality genomic DNA. In this study, we investigated three protocols and compared their simplicity, duration and costs for extracting genomic DNA from Linguatula serrata.Methods: The larvae were collected from the sheep’s visceral organs from the Yazd Slaughterhouse during May 2013. DNA extraction was done in three different methods, including commercial DNA extraction kit, Phenol Chloroform Isoamylalcohol (PCI, and salting out. Extracted DNA in each method was assessed for quantity and quality using spectrophotometery and agarose gel electrophoresis, respectively.Results: The less duration was regarding to commercial DNA extraction kit and then salting out protocol. The cost benefit one was salting out and then PCI method. The best quantity was regarding to PCI with 72.20±29.20 ng/μl, and purity of OD260/OD280 in 1.76±0.947. Agarose gel electrophoresis for assessing the quality found all the same.Conclusion: Salting out is introduced as the best method for DNA extraction from L. seratta as a food-borne pathogen with the least costand appropriate purity. Although, the best purity was regarding to PCI but PCI is not safe as salting out. In addition, the duration of salting out was less than PCI. The least duration was seen in commercial DNA extraction kit, but it is expensive and therefore is not recommended for developing countries where consumption of offal is common.

  1. Acanthamoeba polyphaga, a potential environmental vector for the transmission of food-borne and opportunistic pathogens.

    Science.gov (United States)

    Anacarso, Immacolata; de Niederhäusern, Simona; Messi, Patrizia; Guerrieri, Elisa; Iseppi, Ramona; Sabia, Carla; Bondi, Moreno

    2012-06-01

    The endosymbiotic relationship could represent for many bacteria an important condition favouring their spread in the environment and in foods. For this purpose we studied the behaviour of some food-borne and opportunistic pathogens (Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Salmonella enterica serovar Enteritidis, Aeromonas hydrophila, Yersinia enterocolitica) when internalized in Acanthamoeba polyphaga. Our results confirm the capability of the bacteria tested to grow within amoebal hosts. We can observe two types of interactions of the bacteria internalized in A. polyphaga. The first type, showed by Y. enterocolitica and A. hydrophila, was characterized by an early replication, probably followed by the killing and digestion of the bacteria. The second type, showed by E. faecalis and S. aureus was characterized by the persistence and grow inside the host without lysis. Lastly, when amoebae were co-cultured with L. monocytogenes and S. Enteritidis, an eclipse phase followed by an active intracellular growth was observed, suggesting a third type of predator-prey trend. The extracellular count in presence of A. polyphaga, as a result of an intracellular multiplication and subsequent release, was characterized by an increase of E. faecalis, S. aureus, L. monocytogenes and S. Enteritidis, and by a low or absent cell count for Y. enterocolitica and A. hydrophila. Our study suggests that the investigated food-borne and opportunistic pathogens are, in most cases, able to interact with A. polyphaga, to intracellularly replicate and, lastly, to be potentially spread in the environment, underlining the possible role of this protozoan in food contamination. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Extending the Bacillus cereus group genomics to putative food-borne pathogens of different toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Goltsman, Eugene [U.S. Department of Energy, Joint Genome Institute; Auger, Sandrine [Genetique Microbienne; Galleron, Nathalie [Genetique Microbienne; Segurens, Beatrice [Center National Sequencage, F-91057 Evry, France; Simon, Jorg [Johann Wolfgang Goethe University, Frankfurt am Main, Germany; Dossat, Carole [Genoscope/Centre National de la Recherche Scientifique-Unite Mixte de Recherche; Land, Miriam L [ORNL; Broussolle, Veronique [Securite et Qualite des Produits d' Origine Vegetale; Brillard, Julien [Securite et Qualite des Produits d' Origine Vegetale; Guinebretiere, Marie-Helene [Securite et Qualite des Produits d' Origine Vegetale; Sanchis, Vincent [Genetique Microbienne; Nguen-the, Christophe [Securite et Qualite des Produits d' Origine Vegetale; Lereclus, Didier [Genetique Microbienne; Richardson, P M [U.S. Department of Energy, Joint Genome Institute; Wincker, Patrick [Genoscope/Centre National de la Recherche Scientifique-Unite Mixte de Recherche; Weissenbach, Jean [Genoscope/Centre National de la Recherche Scientifique-Unite Mixte de Recherche; Ehrlich, Dusko [Genetique Microbienne; Sorokin, Alexei [Genetique Microbienne

    2008-01-01

    The Bacillus cereus group represents sporulating soil bacteria containing pathogenic strains which may cause diarrheic or emetic food poisoning outbreaks. Multiple locus sequence typing revealed a presence in natural samples of these bacteria of about 30 clonal complexes. Application of genomic methods to this group was however biased due to the major interest for representatives closely related to Bacillus anthracis. Albeit the most important food-borne pathogens were not yet defined, existing data indicate that they are scattered all over the phylogenetic tree. The preliminary analysis of the sequences of three genomes discussed in this paper narrows down the gaps in our knowledge of the B. cereus group. The strain NVH391-98 is a rare but particularly severe food-borne pathogen. Sequencing revealed that the strain should be a representative of a novel bacterial species, for which the name Bacillus cytotoxis or Bacillus cytotoxicus is proposed. This strain has a reduced genome size compared to other B. cereus group strains. Genome analysis revealed absence of sigma B factor and the presence of genes encoding diarrheic Nhe toxin, not detected earlier. The strain B. cereus F837/76 represents a clonal complex close to that of B. anthracis. Including F837/76, three such B. cereus strains had been sequenced. Alignment of genomes suggests that B. anthracis is their common ancestor. Since such strains often emerge from clinical cases, they merit a special attention. The third strain, KBAB4, is a typical facultative psychrophile generally found in soil. Phylogenic studies show that in nature it is the most active group in terms of gene exchange. Genomic sequence revealed high presence of extra-chromosomal genetic material (about 530 kb) that may account for this phenomenon. Genes coding Nhe-like toxin were found on a big plasmid in this strain. This may indicate a potential mechanism of toxicity spread from the psychrophile strain community. The results of this genomic

  3. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella typhimurium on Chicken Breast Fillet during Cooking

    DEFF Research Database (Denmark)

    de Jong, Aarieke E I; van Asselt, Esther D; Zwietering, Marcel H

    2012-01-01

    cooking enlarged the heat resistance of the food borne pathogens. Additionally, a high challenge temperature or fast heating rate contributed to the level of heat resistance. The data were used to assess the probability of illness (campylobacteriosis) due to consumption of chicken fillet as a function...

  4. Antimicrobial properties of plant essential oils and essences against five important food-borne pathogens.

    Science.gov (United States)

    Smith-Palmer, A; Stewart, J; Fyfe, L

    1998-02-01

    The antimicrobial properties of 21 plant essential oils and two essences were investigated against five important food-borne pathogens, Campylobacter jejuni, Salmonella enteritidis, Escherichia coli, Staphylococcus aureus and Listeria monocytogenes. The oils of bay, cinnamon, clove and thyme were the most inhibitory, each having a bacteriostatic concentration of 0.075% or less against all five pathogens. In general, Gram-positive bacteria were more sensitive to inhibition by plant essential oils than the Gram-negative bacteria. Campylobacter jejuni was the most resistant of the bacteria investigated to plant essential oils, with only the oils of bay and thyme having a bacteriocidal concentration of less than 1%. At 35 degrees C, L. monocytogenes was extremely sensitive to the oil of nutmeg. A concentration of less than 0.01% was bacteriostatic and 0.05% was bacteriocidal, but when the temperature was reduced to 4 degrees, the bacteriostatic concentration was increased to 0.5% and the bacteriocidal concentration to greater than 1%.

  5. Synergy among thymol, eugenol, berberine, cinnamaldehyde and streptomycin against planktonic and biofilm-associated food-borne pathogens.

    Science.gov (United States)

    Liu, Q; Niu, H; Zhang, W; Mu, H; Sun, C; Duan, J

    2015-05-01

    Essential oils have been found to exert antibacterial, antifungal, spasmolytic, and antiplasmodial activity and therapeutic effect in cancer treatment. In this study, the antibacterial activities of four main essential oils' components (thymol (Thy), eugenol (Eug), berberine (Ber), and cinnamaldehyde (Cin)) were evaluated against two food-borne pathogens, Listeria monocytogenes and Salmonella Typhimurium, either alone or in combination with streptomycin. Checkerboard assay demonstrated that Thy and Cin elicited a synergistic effect with streptomycin against L. monocytogenes, while a synergy existed between Cin or Eug and streptomycin against Salm. Typhimurium. Further experiments showed that this synergy was sufficient to eradicate biofilms formed by these two bacteria. Thus, our data highlighted that the combinations of specific components from essential oils and streptomycin were useful for the treatment of food-borne pathogens, which might help prevent the spread of antibiotic resistance through improving antibiotic effectiveness. This study has shown the synergistic effect of four components of essential oil (thymol, eugenol, berberine and cinnamaldehyde) combined with streptomycin on planktonic and biofilm-associated food-borne pathogens Listeria monocytogenes and Salmonella Typhimurium. These findings indicate that combination of specific components of essential oils with streptomycin may provide alternative methods to overcome the problem of food-borne bacteria both in suspension and in biofilm. © 2015 The Society for Applied Microbiology.

  6. Lactobacillus plantarum strains as a bio-control strategy against food-borne pathogenic microorganisms

    Directory of Open Access Journals (Sweden)

    Mattia Pia Arena

    2016-04-01

    their antimicrobial effect. This study emphasizes the tempting use of the tested L. plantarum strains and/or their CFS as antimicrobial agents against food-borne pathogens.

  7. Sugar fatty acid esters inhibit biofilm formation by food-borne pathogenic bacteria

    Science.gov (United States)

    Furukawa, Soichi; Akiyoshi, Yuko; O’Toole, George A.; Ogihara, Hirokazu; Morinaga, Yasushi

    2010-01-01

    Effects of food additives on biofilm formation by food-borne pathogenic bacteria were investigated. Thirty-three potential food additives and 3 related compounds were added to the culture medium at concentrations from 0.001 to 0.1% (w/w), followed by inoculation and cultivation of five biofilm-forming bacterial strains for the evaluation of biofilm formation. Among the tested food additives, 21 showed inhibitory effects of biofilm formation by Staphylococcus aureus and Escherichia coli, and in particular, sugar fatty acid esters showed significant anti-biofilm activity. Sugar fatty acid esters with long chain fatty acid residues (C14-16) exerted their inhibitory effect at the concentration of 0.001%(w/w), but bacterial growth was not affected at this low concentration. Activities of the sugar fatty acid esters positively correlated with the increase of the chain length of the fatty acid residues. Sugar fatty acid esters inhibited the initial attachment of the Staphylococcus aureus cells to the abiotic surface. Sugar fatty acid esters with long chain fatty acid residues (C14-16) also inhibited biofilm formation by Streptococcus mutans and Listeria monocytogenes at 0.01%(w/w), while the inhibition of biofilm formation by Pseudomonas aeruginosa required the addition of a far higher concentration (0.1%(w/w)) of the sugar fatty acid esters. PMID:20089325

  8. Emergence and stability of high-pressure resistance in different food-borne pathogens.

    Science.gov (United States)

    Vanlint, Dietrich; Rutten, Nele; Michiels, Chris W; Aertsen, Abram

    2012-05-01

    High hydrostatic pressure (HHP) processing is becoming a valuable nonthermal food pasteurization technique, although there is reasonable concern that bacterial HHP resistance could compromise the safety and stability of HHP-processed foods. While the degree of natural HHP resistance has already been shown to vary greatly among and within bacterial species, a still unresolved question remains as to what extent different food-borne pathogens can actually develop HHP resistance. In this study, we therefore examined and compared the intrinsic potentials for HHP resistance development among strains of Escherichia coli, Shigella flexneri, Salmonella enterica serovars Typhimurium and Enteritidis, Yersinia enterocolitica, Aeromonas hydrophila, Pseudomonas aeruginosa, and Listeria innocua using a selective enrichment approach. Interestingly, of all strains examined, the acquisition of extreme HHP resistance could be detected in only some of the E. coli strains, indicating that a specific genetic predisposition might be required for resistance development. Furthermore, once acquired, HHP resistance proved to be a very stable trait that was maintained for >80 generations in the absence of HHP exposure. Finally, at the mechanistic level, HHP resistance was not necessarily linked to derepression of the heat shock genes and was not related to the phenomenon of persistence.

  9. Effect of small chain N acyl homoserine lactone quorum sensing signals on biofilms of food-borne pathogens.

    Science.gov (United States)

    A, Jamuna Bai; V, Ravishankar Rai

    2016-09-01

    Quorum sensing or cell to cell communication which includes inter- and intra-cellular communication has been implicated in the production of virulence factor and formation of biofilm in food-borne pathogens. In the present study, the effect of quorum sensing signals on the biofilms of food-borne pathogens has been elucidated. N-butryl homoserine lactone and N-hexanoyl homoserine lactone belonging to acyl homoserine lactone (AHL) family of signaling molecules were investigated for their effect on the biofilm formation (attachment and exopolymeric substance production) in the food-borne pathogens Escherichia coli , Salmonella enterica serovar Typhimurium and Vibrio parahemolyticus . The signaling molecules at a concentration of 1 µM were capable of increasing biofilm formation in all the tested pathogens. There was an increase in the attachment of the bacterial cells and biomass as observed by microtiter plate assay and exopolymeric substances production in the biofilms in presence of the AHLs. Further, it needs to be elucidated if the effect of AHLS on the biofilms of E. coli and S. enterica serovar Typhimurium is SdiA dependent.

  10. Comparison of antibacterial effect of seven 1-monoglycerides on food-borne pathogens or spoilage bacteria

    Directory of Open Access Journals (Sweden)

    Leona Buňková

    2011-01-01

    Full Text Available The aim of this study was to compare under the same conditions in vitro the inhibitory effects of seven 1-monoglycerides (MAG containing fatty acids with a medium chain on ten strains of food-borne pathogens or spoilage gram-positive and gram-negative bacteria (Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Micrococcus luteus, Staphylococcus aureus, Citrobacter freundii, Escherichia coli, Proteus mirabilis, Salmonella enterica ser. Enteritidis and Pseudomonas aeruginosa and on their growth indicatos. The inhibitory effect of MAGs (monocaprylin, monocaprin, monolaurin, monomyristin, monopalmitin, MAG of undecanoic and 10-undecenoic acids at a concentration of 25 – 1500 mg·l-1 was observed. Growth of bacteria in the presence of MAG was studied by means of optical density of bacteria for 24 h. The data were modelled through a Gompertz equation and the lag-time, the maximum specific growth rate and the maximal value reached were calculated. MAGs inhibited mainly the growth of gram-positive bacteria, which was shown by the extended lag-time, decrease in specific growth rate and decrease in cell density. Inhibitory effects of tested MAGs could be ranked from point of view of the minimum inhibitory concentration: MAG-C12:0 > MAG-C11:0 > MAG-C10:0 > MAG-C14:0 > MAG-C11:1 > MAG-C8:0 > MAG-C16:0. In vitro, no significant inhibitory effects of 1-monoglycerides, with the exception of the highest concentrations applied, on the growth of gram-negative bacteria were detected. The main contribution of this study is to compare the effects of several MAG containing fatty acids with a medium chain under the same conditions on the growth indicators of bacteria.

  11. Antibacterial Potential of Jatropha curcas Synthesized Silver Nanoparticles against Food Borne Pathogens

    Science.gov (United States)

    Chauhan, Nitin; Tyagi, Amit K.; Kumar, Pushpendar; Malik, Anushree

    2016-01-01

    The aqueous leaf extract of Jatropha curcas was used for the synthesis of silver nanoparticles (Jc-AgNps) which were further evaluated for its antibacterial potential against food borne pathogens. J. curcas leaf extract could synthesize stable silver nanoparticles (Zeta potential: -23.4 mV) with absorption band at 430 nm. Fourier transform infrared spectroscopy indicated various biological compounds responsible for capping and stabilizing Jc-AgNps in suspension, while the presence of silver was authenticated by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray. Jc-AgNps were confirmed to be uniform in shape, size and behavior through dynamic light scattering, transmission electron microscopy (TEM), X-ray diffraction, SEM, and atomic force microscopy (AFM) analysis. To investigate the antibacterial activity, disk diffusion and microplate dilution assays were performed and zone of inhibition (ZOI) as well as minimum inhibitory/bactericidal concentrations (MIC/MBCs) were evaluated against selected bacterial strains. Overall results showed that Escherichia coli (ZOI: 23 mm, MBC: 0.010 mg/ml) was the most sensitive organism, whereas Staphylococcus aureus (ZOI: 14.66 mm, MBC: 0.041 mg/ml) and Salmonella enterica (ZOI: 16.66 mm, MBC: 0.041 mg/ml) were the least sensitive against Jc-AgNps. The detailed microscopic investigations using SEM, TEM, and AFM were performed to understand the antibacterial impacts of Jc-AgNps against Listeria monocytogenes. SEM and TEM analysis showed the clear deformation and disintegration of treated L. monocytogenes cells, whereas AFM established a decrease in the height and cell surface roughness (root mean square value) in the treated L. monocytogenes. PMID:27877160

  12. Screening food-borne and zoonotic pathogens associated with livestock practices in the Sumapaz region, Cundinamarca, Colombia.

    Science.gov (United States)

    Arenas, Nelson E; Abril, Diego A; Valencia, Paola; Khandige, Surabhi; Soto, Carlos Yesid; Moreno-Melo, Vilma

    2017-04-01

    Hazardous practices regarding antibiotics misuse, unsanitary milking procedures, and the commercial sales of raw milk and unpasteurized dairy products are currently being practiced by livestock farmers in the Sumapaz region (Colombia). The purpose of this study was to screen for food-borne and zoonotic pathogens associated with local livestock practices. We evaluated 1098 cows from 46 livestock farms in the Sumapaz region that were selected by random. Of the total population of cattle, 962 animals (88%) were tested for bovine TB using a caudal-fold tuberculin test and 546 (50%) for brucellosis by a competitive ELISA. In the population tested, 23 cows were positive for Brucella sp. representing a 4.2% seroprevalence and no cases of bovine tuberculosis were found. In addition, food-borne contamination with Escherichia coli and Staphylococcus aureus was assessed together with antibiotic susceptibility for ten different antibiotics in milk samples from 16 livestock farms. We found that 12 of the farms (75%) were contaminated with these food-borne pathogens. Noteworthy, all of the isolated pathogenic strains were resistant to multiple antibiotics, primarily to oxytetracycline and erythromycin. Our findings suggest that livestock products could be a source of exposure to Brucella and multidrug-resistant E. coli and S. aureus strains as a result of unhygienic livestock practices in the Sumapaz region. Training in good farming practices is the key to improving safety in food production.

  13. Antibacterial Effects of (Mentha X Piperita L. Hydroalcoholic Extract on the Six Food-Borne Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    H Zandi

    2016-11-01

    Full Text Available Abstract Introduction: Iran is the richest country in terms of distribution of medicinal plants. The antimicrobial effect of plant extracts and essential oils is well known and they are used as a good substitute in food industry to control food-borne pathogens. Due to the antibacterial activity of plant extracts and their efficacy against microorganisms, the aim of this study was to investigate the antibacterial activity of peppermint extract in order to control pathogenic bacteria. Methods: Piperita L., which is one of the species of mint; was used in this invitro-experimental study. The extraction was performed by percolation method. Well - agar method was used for antibacterial effects of extracts. The minimum inhibitory concentration (MIC and minimal bactericidal concentration (MBC were done for six standard bacteria using microdilution method. The test was performed 3 times for each bacterium. Data were analyzed by using SPSS version 16 and t-test. Results: The lowest MIC of peppermint extract on examined microorganisms were observed for Staphylococcus aureus and Enterococcus faecalis (3.25 mg/ ml. Also the maximum diameter of inhibition zone, was related to Staphylococcus aureus (32 mm. Conclusion: Results of this study indicated that peppermint extract has a favorable control effect on the growth of food borne pathogens, which can be used as a perfect preservative for keeping food.

  14. Campylobacter spp. as emerging food-borne pathogen - incidence, detection and resistance

    Directory of Open Access Journals (Sweden)

    S. Smole Možina

    2005-02-01

    Full Text Available Campylobacter jejuni and Campylobacter. coli are the leading cause of bacterial food-borne enteric infection with still increasing incidence in the most developed countries. Consuming and/or handling poultry meat is the most consistent risk factor, linked to the high prevalence of campylobacters in retail poultry meat. Recent data about the incidence of human campylobacteriosis and prevalence of C.jejuni and C. coli in poultry meat are presented. Important aspects of Campylobacter transmission along the food chain are discussed – physiological specificities possibly enabling adaptation and survival in the food production environment as well as the emerging resistance to antimicrobial agents used in veterinary and human medicine. Recent advances in detection and identification methods of Campylobacter spp. are mentioned as a basis for preventive strategies to bring these food-borne pat hogens under control. Recent risk assessments show that mitigation strategies could be applied at different points from food-animals production to the finalconsumptionoffoods.Educating the consumers is important,sincecritical control point remains the hygiene in the final food preparation.

  15. Analysis of a food-borne fungal pathogen outbreak: virulence and genome of a Mucor circinelloides isolate from yogurt.

    Science.gov (United States)

    Lee, Soo Chan; Billmyre, R Blake; Li, Alicia; Carson, Sandra; Sykes, Sean M; Huh, Eun Young; Mieczkowski, Piotr; Ko, Dennis C; Cuomo, Christina A; Heitman, Joseph

    2014-07-08

    Food-borne pathogens are ongoing problems, and new pathogens are emerging. The impact of fungi, however, is largely underestimated. Recently, commercial yogurts contaminated with Mucor circinelloides were sold, and >200 consumers became ill with nausea, vomiting, and diarrhea. Mucoralean fungi cause the fatal fungal infection mucormycosis, whose incidence has been continuously increasing. In this study, we isolated an M. circinelloides strain from a yogurt container, and multilocus sequence typing identified the strain as Mucor circinelloides f. circinelloides. M. circinelloides f. circinelloides is the most virulent M. circinelloides subspecies and is commonly associated with human infections, whereas M. circinelloides f. lusitanicus and M. circinelloides f. griseocyanus are less common causes of infection. Whole-genome analysis of the yogurt isolate confirmed it as being close to the M. circinelloides f. circinelloides subgroup, with a higher percentage of divergence with the M. circinelloides f. lusitanicus subgroup. In mating assays, the yogurt isolate formed sexual zygospores with the (-) M. circinelloides f. circinelloides tester strain, which is congruent with its sex locus encoding SexP, the (+) mating type sex determinant. The yogurt isolate was virulent in murine and wax moth larva host systems. In a murine gastromucormycosis model, Mucor was recovered from fecal samples of infected mice for up to 10 days, indicating that Mucor can survive transit through the GI tract. In interactions with human immune cells, M. circinelloides f. lusitanicus induced proinflammatory cytokines but M. circinelloides f. circinelloides did not, which may explain the different levels of virulence in mammalian hosts. This study demonstrates that M. circinelloides can spoil food products and cause gastrointestinal illness in consumers and may pose a particular risk to immunocompromised patients. Importance: The U.S. FDA reported that yogurt products were contaminated with M

  16. High-throughput detection of food-borne pathogenic bacteria using oligonucleotide microarray with quantum dots as fluorescent labels.

    Science.gov (United States)

    Huang, Aihua; Qiu, Zhigang; Jin, Min; Shen, Zhiqiang; Chen, Zhaoli; Wang, Xinwei; Li, Jun-Wen

    2014-08-18

    Bacterial pathogens are mostly responsible for food-borne diseases, and there is still substantial room for improvement in the effective detection of these organisms. In the present study, we explored a new method to detect target pathogens easily and rapidly with high sensitivity and specificity. This method uses an oligonucleotide microarray combined with quantum dots as fluorescent labels. Oligonucleotide probes targeting the 16SrRNA gene were synthesized to create an oligonucleotide microarray. The PCR products labeled with biotin were subsequently hybridized using an oligonucleotide microarray. Following incubation with CdSe/ZnS quantum dots coated with streptavidin, fluorescent signals were detected with a PerkinElmer Gx Microarray Scanner. The results clearly showed specific hybridization profiles corresponding to the bacterial species assessed. Two hundred and sixteen strains of food-borne bacterial pathogens, including standard strains and isolated strains from food samples, were used to test the specificity, stability, and sensitivity of the microarray system. We found that the oligonucleotide microarray combined with quantum dots used as fluorescent labels can successfully discriminate the bacterial organisms at the genera or species level, with high specificity and stability as well as a sensitivity of 10 colony forming units (CFU)/mL of pure culture. We further tested 105 mock-contaminated food samples and achieved consistent results as those obtained from traditional biochemical methods. Together, these results indicate that the quantum dot-based oligonucleotide microarray has the potential to be a powerful tool in the detection and identification of pathogenic bacteria in foods. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. [Investigation of pathogenic phenotypes and virulence determinants of food-borne Salmonella enterica strains in Caenorhabditis elegans animal model].

    Science.gov (United States)

    Aksoy, Deniz; Şen, Ece

    2015-10-01

    Salmonellosis, caused by non-typhoidal Salmonella enterica serovars with the consumption of contaminated food, is one of the leading food-borne disease that makes microbial food safety an important public health issue. This study was performed in order to determine the antibiotic resistance, serotyping, plasmid profiles and pathogenicity potentials of food-borne Salmonella isolates in Caenorhabditis elegans animal model system in Edirne province, located at Thrace region of Turkey. In this study, 32 Salmonella isolates, of which 26 belonged to Infantis, four to Enteritidis, one to Telaviv and one to Kentucky serovars, isolated from chicken carcasses were used. Antibiotic resistance profiles were determined by disc diffusion and broth microdilution methods. A new C.elegans nematode animal model system was used to determine the pathogenicity potential of the isolates. The antibiotic resistance profiles revealed that one (3.1%) isolate was resistant to gentamicin, two (6.2%) to ciprofloxacin, three (9.4%) to ampicillin, 18 (56.3%) to kanamycin, 19 (60.8%) to neomycin, 25 (78.1%) to tetracycline, 25 (78.1%) to trimethoprim, 26 (81.25%) to nalidixic acid, 27 (84.4%) to streptomycin and 32 (100%) to sulfonamide. All of the 32 strains were susceptible to chloramphenicol and ampicillin/sulbactam. High levels of resistance to streptomycin, nalidixic acid, tetracycline, trimethoprim, sulfonamide, kanamycin and neomycin was determined. According to the plasmid analysis, six isolates (18.75%) harboured 1-3 plasmids with sizes between 1.2 and 42.4 kb. In C.elegans nematode animal model system, the time (in days) required to kill 50% (TD50) of nematodes was calculated for each experimental group. TD50 values of the nematode group fed with S.Typhimurium ATCC 14028 that was used as the positive control and another group fed with E.coli OP50 as the negative control were 4.2 ± 0.5 days and 8.0 ± 0.02 days, respectively. TD50 of the groups fed with Salmonella isolates ranged

  18. The antibiotic activity and mechanisms of sugarcane (Saccharum officinarum L.) bagasse extract against food-borne pathogens.

    Science.gov (United States)

    Zhao, Yi; Chen, Mingshun; Zhao, Zhengang; Yu, Shujuan

    2015-10-15

    Sugarcane bagasse contains natural compositions that can significantly inhibit food-borne pathogens growth. In the present study, the phenolic content in sugarcane bagasse was detected as higher than 4 mg/g dry bagasse, with 470 mg quercetin/g polyphenol. The sugarcane bagasse extract showed bacteriostatic activity against the growth of Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Salomonella typhimurium. Additionally, the sugarcane bagasse extract can increase the electric conductivity of bacterial cell suspensions causing cellular leaking of electrolytes. Results of sodium dodecyl sulfate polyacrylamide gel electrophoresis suggested the antibacterial mechanism was probably due to the damaged cellular proteins by sugarcane bagasse extract. The results of scanning electron microscopy and transmission electron microscopy showed that the sugarcane bagasse extract might change cell morphology and internal structure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella typhimurium on Chicken Breast Fillet during Cooking

    Directory of Open Access Journals (Sweden)

    Aarieke E.I. de Jong

    2012-01-01

    The surface temperature reached 70∘C within 30 sec and 85∘C within one minute. Extremely high decimal reduction times of 1.90, 1.97, and 2.20 min were obtained for C. jejuni, E. coli, and S. typhimurium, respectively. Chicken meat and refrigerated storage before cooking enlarged the heat resistance of the food borne pathogens. Additionally, a high challenge temperature or fast heating rate contributed to the level of heat resistance. The data were used to assess the probability of illness (campylobacteriosis due to consumption of chicken fillet as a function of cooking time. The data revealed that cooking time may be far more critical than previously assumed.

  20. Antimicrobial Activity of the Essential Oil from the Leaves and Seeds ofCoriandrum sativumtoward Food-borne Pathogens.

    Science.gov (United States)

    Rezaei, M; Karimi, F; Shariatifar, N; Mohammadpourfard, I; Shiri Malekabad, E

    2015-06-03

    The increasing incidence of drug-resistant pathogens and toxicity of existing antibacterial compounds has drawn attention toward the antimicrobial activity of natural products. The purpose of this study is to evaluate the antimicrobial activity of the essential oil of the leaves and seeds of Coriandrum sativum . The five strains of bacteria comprising Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica, Salmonella enterica and Vibrio cholerae were used for the antibacterial tests. In this study, antimicrobial effects of the essential oil from the leaves and seeds of Coriandrum sativum are evaluated by determining the minimum inhibitory concentration (MIC), the inhibition zone and minimum bactericidal concentration (MBC). The essential oil from Coriandrum sativum was extracted by steam distillation. The results indicate that the antimicrobial activities against the five pathogens were in the range of 2.5- 320 µg/mL. Increase in essential oil concentration caused significant increase in inhibitory feature. The essential oil of the leaves and seeds of Coriandrum sativum showed antimicrobial activity against the food-borne pathogenic bacteria. Thus, its oil can be used as an alternative to synthetic food preservative without toxic effects. Also, it can be used in biotechnological fields as ingredients in antibiotics and the pharmaceutical industry. These results suggest that the essential oil of C sativum leaves and seeds may have potential use in pharmaceutical and food industries for preservatives or antimicrobial agents.

  1. Development of a novel approach for the production of dried genomic DNA for use as standards for qualitative PCR testing of food-borne pathogens

    DEFF Research Database (Denmark)

    Trapmann, S.; Catalani, P.; Hoorfar, Jeffrey

    2004-01-01

    , Campylobacter jejuni and Yersinia enterocolitica were used to produce genomic DNA (gDNA). These preparations gave support to method development for qualitative polymerase chain reaction (PCR) detection methods for food-borne pathogens. Purified gDNA was transformed into stable and dry gDNA by using...

  2. MALDI-TOF MS identification and tracking of food spoilers and food-borne pathogens

    NARCIS (Netherlands)

    de Koster, C.G.; Brul, S.

    2016-01-01

    Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) is an established tool for identification of clinical relevant pathogens. MALDI-TOF MS is increasingly accepted as a molecular characterization tool and method for identification of genera, species and

  3. Gut physiology mediates a trade-off between adaptation to malnutrition and susceptibility to food-borne pathogens.

    Science.gov (United States)

    Vijendravarma, Roshan K; Narasimha, Sunitha; Chakrabarti, Sveta; Babin, Aurelie; Kolly, Sylvain; Lemaitre, Bruno; Kawecki, Tadeusz J

    2015-10-01

    The animal gut plays a central role in tackling two common ecological challenges, nutrient shortage and food-borne parasites, the former by efficient digestion and nutrient absorption, the latter by acting as an immune organ and a barrier. It remains unknown whether these functions can be independently optimised by evolution, or whether they interfere with each other. We report that Drosophila melanogaster populations adapted during 160 generations of experimental evolution to chronic larval malnutrition became more susceptible to intestinal infection with the opportunistic bacterial pathogen Pseudomonas entomophila. However, they do not show suppressed immune response or higher bacterial loads. Rather, their increased susceptibility to P. entomophila is largely mediated by an elevated predisposition to loss of intestinal barrier integrity upon infection. These results may reflect a trade-off between the efficiency of nutrient extraction from poor food and the protective function of the gut, in particular its tolerance to pathogen-induced damage. © 2015 The Authors Ecology Letters published by John Wiley & Sons Ltd and CNRS.

  4. Detection of food-borne pathogens by nanoparticle technology coupled to a low-cost cell reader

    Science.gov (United States)

    Noiseux, Isabelle; Bouchard, Jean-Pierre; Gallant, Pascal; Bourqui, Pascal; Cao, Honghe; Vernon, Marci; Johnson, Roger; Chen, Shu; Mermut, Ozzy

    2010-02-01

    The detection, identification and quantification of pathogenic microorganisms at low cost are of great interest to the agro-food industry. We have developed a simple, rapid, sensitive, and specific method for detection of food-borne pathogens based on use of nanoparticles alongside a low cost fluorescence cell reader for the bioassay. The nanoparticles are coupled with antibodies that allow specific recognition of the targeted Listeria in either a liquid or food matrix. The bioconjugated nanoparticles (FNP) contain thousands of dye molecules enabling significant amplification of the fluorescent signal emitted from each bacterium. The developed fluorescence Cell Reader is an LED-based reader coupled with suitable optics and a camera that acquires high resolution images. The dedicated algorithm allowed the counting of each individual nanoparticles-fluorescent bacterial cells thus enabling highly sensitive reading. The system allows, within 1 hour, the recovery and counting of 104 to 108 cfu/mL of Listeria in pure culture. However, neither the Cell Reader nor the algorithm can differentiate between the FNPs specifically-bound to the target and the residual unbound FNPs limiting sensitivity of the system. Since FNPs are too small to be washed in the bioassay, a dual tagging approach was implemented to allow online optical separation of the fluorescent background caused by free FNPs.

  5. Next generation sequencing-based multigene panel for high throughput detection of food-borne pathogens.

    Science.gov (United States)

    Ferrario, Chiara; Lugli, Gabriele Andrea; Ossiprandi, Maria Cristina; Turroni, Francesca; Milani, Christian; Duranti, Sabrina; Mancabelli, Leonardo; Mangifesta, Marta; Alessandri, Giulia; van Sinderen, Douwe; Ventura, Marco

    2017-09-01

    Contamination of food by chemicals or pathogenic bacteria may cause particular illnesses that are linked to food consumption, commonly referred to as foodborne diseases. Bacteria are present in/on various foods products, such as fruits, vegetables and ready-to-eat products. Bacteria that cause foodborne diseases are known as foodborne pathogens (FBPs). Accurate detection methods that are able to reveal the presence of FBPs in food matrices are in constant demand, in order to ensure safe foods with a minimal risk of causing foodborne diseases. Here, a multiplex PCR-based Illumina sequencing method for FBP detection in food matrices was developed. Starting from 25 bacterial targets and 49 selected PCR primer pairs, a primer collection called foodborne pathogen - panel (FPP) consisting of 12 oligonucleotide pairs was developed. The FPP allows a more rapid and reliable identification of FBPs compared to classical cultivation methods. Furthermore, FPP permits sensitive and specific FBP detection in about two days from food sample acquisition to bioinformatics-based identification. The FPP is able to simultaneously identify eight different bacterial pathogens, i.e. Listeria monocytogenes, Campylobacter jejuni, Campylobacter coli, Salmonella enterica subsp. enterica serovar enteritidis, Escherichia coli, Shigella sonnei, Staphylococcus aureus and Yersinia enterocolitica, in a given food matrix at a threshold contamination level of 10 1 cell/g. Moreover, this novel detection method may represent an alternative and/or a complementary approach to PCR-based techniques, which are routinely used for FBP detection, and could be implemented in (parts of) the food chain as a quality check. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Proteomic profiling of Cronobacter turicensis 3032, a food-borne opportunistic pathogen.

    Science.gov (United States)

    Carranza, Paula; Hartmann, Isabel; Lehner, Angelika; Stephan, Roger; Gehrig, Peter; Grossmann, Jonas; Barkow-Oesterreicher, Simon; Roschitzki, Bernd; Eberl, Leo; Riedel, Kathrin

    2009-07-01

    Members of the genus Cronobacter are opportunistic pathogens for neonates and are often associated with contaminated milk powder formulas. At present little is known about the virulence mechanisms or the natural reservoir of these organisms. The proteome of Cronobacter turicensis 3032, which has recently caused two deaths, was mapped aiming at a better understanding of physiology and putative pathogenic traits of this clinical isolate. Our analyses of extracellular, surface-associated and whole-cell proteins by two complementary proteomics approaches, 1D-SDS-PAGE combined with LC-ESI-MS/MS and 2D-LC-MALDI-TOF/TOF MS, lead to the identification of 832 proteins corresponding to a remarkable 19% of the theoretically expressed protein complement of C. turicensis. The majority of the identified proteins are involved in central metabolic pathways, translation, protein folding and stability. Several putative virulence factors, whose expressions were confirmed by phenotypic assays, could be identified: a macrophage infectivity potentiator involved in C. turicensis persistence in host cells, a superoxide dismutase protecting the pathogen against reactive oxygen species and an enterobactin-receptor protein for the uptake of siderophore-bound iron. Most interestingly, a chitinase and a metalloprotease that might act against insects and fungi but no casein hydrolysing enzymes were found, suggesting that there is an environmental natural habitat of C. turicensis 3032.

  7. Piecewise linear approximations to model the dynamics of adaptation to osmotic stress by food-borne pathogens.

    Science.gov (United States)

    Métris, Aline; George, Susie M; Ropers, Delphine

    2017-01-02

    Addition of salt to food is one of the most ancient and most common methods of food preservation. However, little is known of how bacterial cells adapt to such conditions. We propose to use piecewise linear approximations to model the regulatory adaptation of Escherichiacoli to osmotic stress. We apply the method to eight selected genes representing the functions known to be at play during osmotic adaptation. The network is centred on the general stress response factor, sigma S, and also includes a module representing the catabolic repressor CRP-cAMP. Glutamate, potassium and supercoiling are combined to represent the intracellular regulatory signal during osmotic stress induced by salt. The output is a module where growth is represented by the concentration of stable RNAs and the transcription of the osmotic gene osmY. The time course of gene expression of transport of osmoprotectant represented by the symporter proP and of the osmY is successfully reproduced by the network. The behaviour of the rpoS mutant predicted by the model is in agreement with experimental data. We discuss the application of the model to food-borne pathogens such as Salmonella; although the genes considered have orthologs, it seems that supercoiling is not regulated in the same way. The model is limited to a few selected genes, but the regulatory interactions are numerous and span different time scales. In addition, they seem to be condition specific: the links that are important during the transition from exponential to stationary phase are not all needed during osmotic stress. This model is one of the first steps towards modelling adaptation to stress in food safety and has scope to be extended to other genes and pathways, other stresses relevant to the food industry, and food-borne pathogens. The method offers a good compromise between systems of ordinary differential equations, which would be unmanageable because of the size of the system and for which insufficient data are available

  8. Inhibition Effect of Lactic Acid Bacteria against Food Born Pathogen, Listeria monocytogenes

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    Rouha Kasra-Kermanshahi

    2015-09-01

    Full Text Available Disease caused by consuming microbial contaminated food has increased significantly in recent years due to changes in the livelihoods and eating habits of the human populations. Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella enterica are three of the most important foodborne bacterial pathogens and can lead to foodborne diseases. Increased use of antibiotics, has led to development of bacterial resistance to antibiotics. Therefore, there is growing interest in the development of new types of effective and nontoxic antimicrobial compounds. Nowadays, the most extensive research and commercial practices are based on probiotic bacteria. Probiotics, specifically lactic acid bacteria are widely used in the food industry for fermentation but have gained attention from health professionals because of their potential beneficial effects. Now probiotic therapy is thought to be an effective way to improve the gut health and an alternative to antibiotic treatments. They contribute to food safety by their ability to inhibit the growth of several other bacteria. LAB can be used as protective cultures to compete with potential pathogens and other undesired organisms, thereby increasing the safety of the food product.

  9. Nanostructured Electrochemical Biosensors for Label-Free Detection of Water- and Food-Borne Pathogens.

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    Reta, Nekane; Saint, Christopher P; Michelmore, Andrew; Prieto-Simon, Beatriz; Voelcker, Nicolas H

    2018-02-21

    The emergence of nanostructured materials has opened new horizons in the development of next generation biosensors. Being able to control the design of the electrode interface at the nanoscale combined with the intrinsic characteristics of the nanomaterials engenders novel biosensing platforms with improved capabilities. The purpose of this review is to provide a comprehensive and critical overview of the latest trends in emerging nanostructured electrochemical biosensors. A detailed description and discussion of recent approaches to construct label-free electrochemical nanostructured electrodes is given with special focus on pathogen detection for environmental monitoring and food safety. This includes the use of nanoscale materials such as nanotubes, nanowires, nanoparticles, and nanosheets as well as porous nanostructured materials including nanoporous anodic alumina, mesoporous silica, porous silicon, and polystyrene nanochannels. These platforms may pave the way toward the development of point-of-care portable electronic devices for applications ranging from environmental analysis to biomedical diagnostics.

  10. Antimicrobial activities of commercial essential oils and their components against food-borne pathogens and food spoilage bacteria

    Science.gov (United States)

    Mith, Hasika; Duré, Rémi; Delcenserie, Véronique; Zhiri, Abdesselam; Daube, Georges; Clinquart, Antoine

    2014-01-01

    This study was undertaken to determine the in vitro antimicrobial activities of 15 commercial essential oils and their main components in order to pre-select candidates for potential application in highly perishable food preservation. The antibacterial effects against food-borne pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and enterohemorrhagic Escherichia coli O157:H7) and food spoilage bacteria (Brochothrix thermosphacta and Pseudomonas fluorescens) were tested using paper disk diffusion method, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Most of the tested essential oils exhibited antimicrobial activity against all tested bacteria, except galangal oil. The essential oils of cinnamon, oregano, and thyme showed strong antimicrobial activities with MIC ≥ 0.125 μL/mL and MBC ≥ 0.25 μL/mL. Among tested bacteria, P. fluorescens was the most resistant to selected essential oils with MICs and MBCs of 1 μL/mL. The results suggest that the activity of the essential oils of cinnamon, oregano, thyme, and clove can be attributed to the existence mostly of cinnamaldehyde, carvacrol, thymol, and eugenol, which appear to possess similar activities against all the tested bacteria. These materials could be served as an important natural alternative to prevent bacterial growth in food products. PMID:25473498

  11. Antimicrobial activities of commercial essential oils and their components against food-borne pathogens and food spoilage bacteria.

    Science.gov (United States)

    Mith, Hasika; Duré, Rémi; Delcenserie, Véronique; Zhiri, Abdesselam; Daube, Georges; Clinquart, Antoine

    2014-07-01

    This study was undertaken to determine the in vitro antimicrobial activities of 15 commercial essential oils and their main components in order to pre-select candidates for potential application in highly perishable food preservation. The antibacterial effects against food-borne pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and enterohemorrhagic Escherichia coli O157:H7) and food spoilage bacteria (Brochothrix thermosphacta and Pseudomonas fluorescens) were tested using paper disk diffusion method, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Most of the tested essential oils exhibited antimicrobial activity against all tested bacteria, except galangal oil. The essential oils of cinnamon, oregano, and thyme showed strong antimicrobial activities with MIC ≥ 0.125 μL/mL and MBC ≥ 0.25 μL/mL. Among tested bacteria, P. fluorescens was the most resistant to selected essential oils with MICs and MBCs of 1 μL/mL. The results suggest that the activity of the essential oils of cinnamon, oregano, thyme, and clove can be attributed to the existence mostly of cinnamaldehyde, carvacrol, thymol, and eugenol, which appear to possess similar activities against all the tested bacteria. These materials could be served as an important natural alternative to prevent bacterial growth in food products.

  12. Chemical Composition and In Vitro Antibacterial Activity of Mentha spicata Essential Oil against Common Food-Borne Pathogenic Bacteria.

    Science.gov (United States)

    Shahbazi, Yasser

    2015-01-01

    The aim of the present study was to investigate chemical composition and antibacterial activity of essential oil from the leaf of Mentha spicata plant against common food-borne pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium, and Escherichia coli O157:H7). Chemical composition of the essential oil was identified by gas chromatography coupled with mass spectrometer detector (GC-MS). The antibacterial activity of the essential oil was evaluated by broth microdilution method and agar disk diffusion assay. According to the result of GC-MS analysis, 18 components were identified, accounting for 99.89% of the whole essential oil. The main components were carvone (78.76%), limonene (11.50%), β-bourbonene (11.23%), cis-dihydrocarveol (1.43%), trans-caryophyllene (1.04%), menthone (1.01%), menthol (1%), and terpinen-4-ol (0.99). The essential oil exhibited moderate level of antibacterial activity against all test microorganisms. In general, Gram-positive bacteria were more susceptible to M. spicata essential oil than Gram-negative bacteria. L. monocytogenes was the most sensitive of the microorganisms to the antibacterial activity of M. spicata essential oil (inhibition zone = 22 mm and MIC and MBC = 2.5 µL/mL). Based on our results, the essential oil of M. spicata plant collected from Kermanshah province, west of Iran, has a potential to be applied as antibacterial agent.

  13. Chemical Composition and In Vitro Antibacterial Activity of Mentha spicata Essential Oil against Common Food-Borne Pathogenic Bacteria

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    Yasser Shahbazi

    2015-01-01

    Full Text Available The aim of the present study was to investigate chemical composition and antibacterial activity of essential oil from the leaf of Mentha spicata plant against common food-borne pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium, and Escherichia coli O157:H7. Chemical composition of the essential oil was identified by gas chromatography coupled with mass spectrometer detector (GC-MS. The antibacterial activity of the essential oil was evaluated by broth microdilution method and agar disk diffusion assay. According to the result of GC-MS analysis, 18 components were identified, accounting for 99.89% of the whole essential oil. The main components were carvone (78.76%, limonene (11.50%, β-bourbonene (11.23%, cis-dihydrocarveol (1.43%, trans-caryophyllene (1.04%, menthone (1.01%, menthol (1%, and terpinen-4-ol (0.99. The essential oil exhibited moderate level of antibacterial activity against all test microorganisms. In general, Gram-positive bacteria were more susceptible to M. spicata essential oil than Gram-negative bacteria. L. monocytogenes was the most sensitive of the microorganisms to the antibacterial activity of M. spicata essential oil (inhibition zone = 22 mm and MIC and MBC = 2.5 µL/mL. Based on our results, the essential oil of M. spicata plant collected from Kermanshah province, west of Iran, has a potential to be applied as antibacterial agent.

  14. Evaluation of different extraction methods on antimicrobial potency of Adenium obesum stem against food borne pathogenic bacterial strains in Oman

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    Mohammad Amzad Hossain

    2014-09-01

    Full Text Available Objective: To determine and compare the effect on antimicrobial potency of crude stems extract of Adenium obesum (A. obesum by Soxhlet and maceration extraction methods. Methods: The crude extracts were prepared from the coarse samples of stems with methanol by using Soxhlet and maceration extraction methods. Both the crude extracts from two extraction methods were dissolved in water and successively extracted by different polarities solvents with increasing polarities. In vitro antimicrobial potency of different polarities crude extracts obtained from Soxhlet and maceration methods was determined by agar gel diffusion method against different food borne pathogenic bacterial strains. Results: The results for antimicrobial potency of different crude extracts were almost similar by Soxhlet and maceration and methods. The average range of inhibition potency of different polarities crude extracts was 0%-17% by Soxhlet method and inhibition potency 0%-24% by maceration method. Conclusions: These results obtained from in vitro approach give promising basic information about this plant as well as some potential crude extracts can be used for the treatment of infectious diseases.

  15. Antibacterial Activity of Fructus forsythia Essential Oil and the Application of EO-Loaded Nanoparticles to Food-Borne Pathogens

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    Na Guo

    2016-10-01

    Full Text Available Fructus forsythia essential oil (FEO with excellent antibacterial activity was rarely reported. The objective of the present study was to investigate the antibacterial activity and the antibacterial mechanism of FEO against two food-borne pathogenic bacteria, Escherichia coli (E. coli and Staphylococcus aureus (S. aureus in vitro. When treated FEO, the zones of inhibition (ZOI of E. coli (20.5 ± 0.25 mm and S. aureus (24.3 ± 0.21 mm were much larger than control (p < 0.05. The minimum inhibitory concentrations (MICs of FEO were 3.13 mg/mL and 1.56 mg/mL for E. coli and S. aureus, respectively. The antibacterial mechanism of FEO against E. coil was due to the changes in permeability and integrity of cell membrane leading to the leakage of nucleic acids and proteins. With the superior antibacterial activity of FEO, the nano-encapsulation method has been applied in FEO. When compared to FEO and blank chitosan nanoparticles, FEO-loaded nanoparticles (chitosan to FEO of 1:1 can effectively inhibit the growth of E. coil above 90% at room temperature. It is necessary to consider that FEO and FEO-loaded nanoparticles will become promising antibacterial additives for food preservative, cosmetic, and pharmaceutical applications.

  16. Isolation, taxonomic identification and hydrogen peroxide production by Lactobacillus delbrueckii subsp. lactis T31, isolated from Mongolian yoghurt: inhibitory activity on food-borne pathogens.

    Science.gov (United States)

    Batdorj, B; Trinetta, V; Dalgalarrondo, M; Prévost, H; Dousset, X; Ivanova, I; Haertlé, T; Chobert, J-M

    2007-09-01

    The aim of this work was to isolate lactic acid bacteria (LAB) strains from Mongolian tarag (a traditionally homemade yoghurt) displaying antimicrobial activities against food-borne pathogens, identify inhibitory substances and study the kinetics of their production. Inhibitory substance-producing bacterial strains were isolated from tarag. From 300 bacterial clones, 31 were able to inhibit the growth of the indicator strain Lactobacillus bulgaricus 340. One of the most active strains was identified as Lactobacillus delbrueckii subsp. lactis strain T31 by using cluster analysis of amplified fragment length polymorphism (AFLP) DNA fingerprints. The antimicrobial substance was inactivated by catalase, demonstrating the production of hydrogen peroxide (H(2)O(2)). Production of H(2)O(2) was studied under aerated and nonaerated culture conditions. The amount of H(2)O(2) in the culture supernatant increased during bacterial growth and reached a maximum (5.12 mmol l(-1)) at the early stationary phase under aerated conditions (agitated cultures). H(2)O(2) was not detected in the culture performed without agitation. In mixed cultures performed in milk with either Lact. delbrueckii subsp. lactis T31 in the presence of Escherichia coli, or Lact. delbrueckii subsp. lactis T31 in the presence of Listeria innocua under aerated and nonaerated conditions, a significant decrease in pathogen count was observed in aerated cultures. The significant decrease in Listeria viability observed in aerated mixed cultures of Lact. delbrueckii subsp. lactis T31 is mainly because of H(2)O(2) production. Lactobacillus delbrueckii subsp. lactis T31 could be used as a protective culture in food industries or as a probiotic to prevent intestinal and urogenital infections.

  17. A gel-free quantitative proteomics approach to investigate temperature adaptation of the food-borne pathogen Cronobacter turicensis 3032.

    Science.gov (United States)

    Carranza, Paula; Grunau, Alexander; Schneider, Thomas; Hartmann, Isabel; Lehner, Angelika; Stephan, Roger; Gehrig, Peter; Grossmann, Jonas; Groebel, Katrin; Hoelzle, Ludwig E; Eberl, Leo; Riedel, Kathrin

    2010-09-01

    The opportunistic food-borne pathogen Cronobacter sp. causes rare but significant illness in neonates and is capable to grow at a remarkably wide range of temperatures from 5.5 to 47 degrees C. A gel-free quantitative proteomics approach was employed to investigate the molecular basis of the Cronobacter sp. adaptation to heat and cold-stress. To this end the model strain Cronobacter turicensis 3032 was grown at 25, 37, 44, and 47 degrees C, and whole-cell and secreted proteins were iTRAQ-labelled and identified/quantified by 2-D-LC-MALDI-TOF/TOF-MS. While 44 degrees C caused only minor changes in C. turicensis growth rate and protein profile, 47 degrees C affected the expression of about 20% of all 891 identified proteins and resulted in a reduced growth rate and rendered the strain non-motile and filamentous. Among the heat-induced proteins were heat shock factors, transcriptional and translational proteins, whereas proteins affecting cellular morphology, proteins involved in motility, central metabolism and energy production were down-regulated. Notably, numerous potential virulence factors were found to be up-regulated at higher temperatures, suggesting an elevated pathogenic potential of Cronobacter sp. under these growth conditions. Significant alterations in the protein expression profile and growth rate of C. turicensis exposed to 25 degrees C indicate that at this temperature the organism is cold-stressed. Up-regulated gene products comprised cold-shock, DNA-binding and ribosomal proteins, factors that support protein folding and proteins opposing cold-induced decrease in membrane fluidity, whereas down-regulated proteins were mainly involved in central metabolism.

  18. Characterization of aerobic and anaerobic vegetative growth of the food-borne pathogen Bacillus cereus F4430/73 strain.

    Science.gov (United States)

    Rosenfeld, Eric; Duport, Catherine; Zigha, Assia; Schmitt, Philippe

    2005-02-01

    The Gram-positive bacterium Bacillus cereus is a facultative anaerobe that is still poorly characterized metabolically. In this study, the aerobic vegetative growth and anaerobic vegetative growth of the food-borne pathogen B. cereus F4430/73 strain were compared with those of the genome-sequenced ATCC14579 strain using glucose and glycerol as fermentative and nonfermentative carbon sources, respectively. Uncontrolled batch cultures on several defined media showed that B. cereus strains had high amino acid or pyruvate requirements for anaerobic fermentative growth. In addition, growth performance was considerably improved by maintaining the pH of the culture medium near neutrality. Spectra of fermentation by-products were typically (per mole of glucose) 0.2-0.4 acetate, 1.1-1.4 L-lactate, 0.3-0.4 formate, and 0.05-0.2 ethanol with only traces of succinate, pyruvate, and 2,3-butanediol. These spectra were drastically changed in the presence of 20 mmol nitrate x L(-1), which stimulated anaerobic growth. During anaerobic and aerobic respiration, the persistent production of acetate and other by-products indicated overflow metabolisms. This was especially true in glucose-grown cells for which respiratory complex III made only a minor contribution to growth. Surprisingly, oxygen uptake rates linked to the cytochrome c and quinol branches of the respiratory chain were maintained at high levels in anaerobic, respiring, or fermenting cells. Growth and metabolic features of B. cereus F4430/73 are discussed using biochemical and genomic data.

  19. In Vitro Evaluation of the Antibiogramic Activities of the Seeds of Myristica fragrans on Food Borne Pathogens

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    Emefo, O. T.

    2012-01-01

    Full Text Available Aims: Foodborne diseases have been shown to have direct impact on the health and welfare of a large number of the world population. The in vitro antibiogramic properties of natural spices (Myristica fragrans on common food borne pathogen became necessary both in improving food safety and development of new drugs. Methodology and Results: Test isolates (Staphylococcus aureus, S. epidermidis, Klebsiella pneumoniae, Bacillus cereus, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa were collected from the culture collection unit of the department of Microbiology, Benson Idahosa University, Nigeria. Seeds of M. fragrans were extracted by soxhlet extractor using ethanol and water, while the oil was obtained by steam distillation. The extracts and oil were tested against the bacterial isolates using agar well diffusion method at varying concentration (12.5, 25, 50 and 100 mg/mL. The oil of M. fragrans was found to have the highest antibiogramic activity on the selected isolates, followed by its ethanolic extract with zones of inhibition ranging from 0-24 mm and 0-16 mm respectively. The aqueous extract of M. fragrans was found to be effective against E. coli, P. aeruginosa and S. epidermidis only at 100 mg/mL. The MIC was also higher in oil extract of M. fragrans compared to its ethanolic and aqueous extracts. Conclusion, Significance and Impact of study: The oil and aqueous extract of M. fragrans showed antibiogramic properties against the bacterial isolates used at different concentrations. Thus, its oil can be used as an alternative to synthetic food preservative found to harbor toxic effects and could also serve as sources for development of new antibiotics.

  20. Novel Drug Targets for Food-Borne Pathogen Campylobacter jejuni: An Integrated Subtractive Genomics and Comparative Metabolic Pathway Study.

    Science.gov (United States)

    Mehla, Kusum; Ramana, Jayashree

    2015-07-01

    Campylobacters are a major global health burden and a cause of food-borne diarrheal illness and economic loss worldwide. In developing countries, Campylobacter infections are frequent in children under age two and may be associated with mortality. In developed countries, they are a common cause of bacterial diarrhea in early adulthood. In the United States, antibiotic resistance against Campylobacter is notably increased from 13% in 1997 to nearly 25% in 2011. Novel drug targets are urgently needed but remain a daunting task to accomplish. We suggest that omics-guided drug discovery is timely and worth considering in this context. The present study employed an integrated subtractive genomics and comparative metabolic pathway analysis approach. We identified 16 unique pathways from Campylobacter when compared against H. sapiens with 326 non-redundant proteins; 115 of these were found to be essential in the Database of Essential Genes. Sixty-six proteins among these were non-homologous to the human proteome. Six membrane proteins, of which four are transporters, have been proposed as potential vaccine candidates. Screening of 66 essential non-homologous proteins against DrugBank resulted in identification of 34 proteins with drug-ability potential, many of which play critical roles in bacterial growth and survival. Out of these, eight proteins had approved drug targets available in DrugBank, the majority serving crucial roles in cell wall synthesis and energy metabolism and therefore having the potential to be utilized as drug targets. We conclude by underscoring that screening against these proteins with inhibitors may aid in future discovery of novel therapeutics against campylobacteriosis in ways that will be pathogen specific, and thus have minimal toxic effect on host. Omics-guided drug discovery and bioinformatics analyses offer the broad potential for veritable advances in global health relevant novel therapeutics.

  1. Antimicrobial activity of Piper nigrum L. and Cassia didymobotyra L. leaf extract on selected food borne pathogens

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    Mohd. Sayeed Akthar

    2014-09-01

    Full Text Available Objective: To investigate the antimicrobial activity of leaf extract of Piper nigrum (P. nigrum and Cassia didymobotyra (C. didymobotyra (aqueous, methanol, ethanol and petroleum ether against the food borne pathogenic bacteria [Staphylococcus aureus (S. aureus, Escherichia coli (E. coli, Salmonella typhimurium and Pseudomonas aeruginosa] and fungi [Aspergillus spp. and Candida albicans (C. albicans] and also to investigate the presence of various phytochemicals in the leaf extracts of tested plants. Methods: The antimicrobial activity was determined by disc diffusion method. Minimum inhibitory concentration (MIC, minimum bactericidal and fungicidal concentration were determined by serial dilution method. Results: Methanol leaf extract of test plants exhibited greater antimicrobial activity against the selected bacterial and fungal strains. The MIC results showed that ethanol, methanol and petroleum ether leaf extract of P. nigrum inhibited the growth of S. aureus and E. coli at concentration of 12.5 mg/mL. While, ethanol and methanol leaf extracts of C. didymobotyra inhibited the growth of S. aureus at concentration of 6.25 mg/mL. The MIC values for ethanol, methanol and petroleum ether leaf extract of P. nigrum inhibited the growth of C. albicans at concentration of 25.0 mg/mL. While, it was reported that at concentration of 12.5 mg/mL methanol leaf extract of P. nigrum was against the Aspergillus spp. The MIC values of methanol leaf extract of C. didymobotyra inhibited the growth of C. albicans and Aspergillus spp. at concentration of 12.5 mg/mL and 6.25 mg/mL, respectively. The minimum bactericidal concentration of ethanol, methanol leaf extract of P. nigrum for E. coli and ethanol, methanol leaf extract of C. didymobotyra for S. aureus was recorded at concentration 12.5 mg/mL. The minimum fungicidal concentration of ethanol and methanol leaf extract of P. nigrum and C. didymobotyra on C. albicans was recorded at concentration of 25.0 mg

  2. Design and Elementary Evaluation of a Highly-Automated Fluorescence-Based Instrument System for On-Site Detection of Food-Borne Pathogens

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    Zhan Lu

    2017-02-01

    Full Text Available A simple, highly-automated instrument system used for on-site detection of foodborne pathogens based on fluorescence was designed, fabricated, and preliminarily tested in this paper. A corresponding method has been proved effective in our previous studies. This system utilizes a light-emitting diode (LED to excite fluorescent labels and a spectrometer to record the fluorescence signal from samples. A rotation stage for positioning and switching samples was innovatively designed for high-throughput detection, ten at most in one single run. We also developed software based on LabVIEW for data receiving, processing, and the control of the whole system. In the test of using a pure quantum dot (QD solution as a standard sample, detection results from this home-made system were highly-relevant with that from a well-commercialized product and even slightly better reproducibility was found. And in the test of three typical kinds of food-borne pathogens, fluorescence signals recorded by this system are highly proportional to the variation of the sample concentration, with a satisfied limit of detection (LOD (nearly 102–103 CFU·mL−1 in food samples. Additionally, this instrument system is low-cost and easy-to-use, showing a promising potential for on-site rapid detection of food-borne pathogens.

  3. Arcobacter: an emerging food-borne zoonotic pathogen, its public health concerns and advances in diagnosis and control - a comprehensive review.

    Science.gov (United States)

    Ramees, Thadiyam Puram; Dhama, Kuldeep; Karthik, Kumaragurubaran; Rathore, Ramswaroop Singh; Kumar, Ashok; Saminathan, Mani; Tiwari, Ruchi; Malik, Yashpal Singh; Singh, Raj Kumar

    2017-12-01

    Arcobacter has emerged as an important food-borne zoonotic pathogen, causing sometimes serious infections in humans and animals. Newer species of Arcobacter are being incessantly emerging (presently 25 species have been identified) with novel information on the evolutionary mechanisms and genetic diversity among different Arcobacter species. These have been reported from chickens, domestic animals (cattle, pigs, sheep, horses, dogs), reptiles (lizards, snakes and chelonians), meat (poultry, pork, goat, lamb, beef, rabbit), vegetables and from humans in different countries. Arcobacters are implicated as causative agents of diarrhea, mastitis and abortion in animals, while causing bacteremia, endocarditis, peritonitis, gastroenteritis and diarrhea in humans. Three species including A. butzleri, A. cryaerophilus and A. skirrowii are predominantly associated with clinical conditions. Arcobacters are primarily transmitted through contaminated food and water sources. Identification of Arcobacter by biochemical tests is difficult and isolation remains the gold standard method. Current diagnostic advances have provided various molecular methods for efficient detection and differentiation of the Arcobacters at genus and species level. To overcome the emerging antibiotic resistance problem there is an essential need to explore the potential of novel and alternative therapies. Strengthening of the diagnostic aspects is also suggested as in most cases Arcobacters goes unnoticed and hence the exact epidemiological status remains uncertain. This review updates the current knowledge and many aspects of this important food-borne pathogen, namely etiology, evolution and emergence, genetic diversity, epidemiology, the disease in animals and humans, public health concerns, and advances in its diagnosis, prevention and control.

  4. Detection and identification of food-borne pathogens of the genera Campylobacter, Arcobacter and Helicobacter by multiplex PCR in poultry and poultry products.

    Science.gov (United States)

    Neubauer, C; Hess, M

    2006-10-01

    The objective of this study was to develop a multiplex polymerase chain reaction (PCR) to detect and differentiate food-borne pathogens of the three genera Campylobacter, Arcobacter and Helicobacter in a single step procedure. One common reverse primer and three genus-specific forward primers were designed by hybridizing to the 16S rRNA of selected reference strains. Besides the species with significance as food-borne pathogens isolated from poultry meat--Campylobacter jejuni, Campylobacter coli, Arcobacter butzleri and Helicobacter pullorum--several other members of these genera were tested to determine the specificity of the designed multiplex PCR. In total, 20 ATCC and NCTC reference strains of Campyobacter, Arcobacter and Helicobacter were used to evaluate the PCR. Specific amplificates were obtained from all thermophilic species of Campylobacter as well as from species of Arcobacter and Helicobacter. No amplification product was obtained from the non-thermophilic Campylobacter, C. hyointestinalis and C. fetus. Furthermore, a total of 43 field strains of the three genera isolated from poultry, pigs, cattle and humans were investigated using this PCR. To confirm the classification of 10 H. pullorum strains the 16S rRNAs were sequenced. The developed PCR is a helpful diagnostic tool to detect and differentiate Campylobacter, Arcobacter and Helicobacter isolated from poultry and poultry products.

  5. In vitro assessment of the antimicrobial potentials of Lactobacillus helveticus strains isolated from traditional cheese in Sinkiang China against food-borne pathogens.

    Science.gov (United States)

    Bian, Xin; Evivie, Smith Etareri; Muhammad, Zafarullah; Luo, Guang-Wen; Liang, Hong-Zhang; Wang, Na-Na; Huo, Gui-Cheng

    2016-02-01

    Lactobacillus helveticus, an obligatory hetero-fermentative LAB, is Generally Recognized as Safe (GRAS) and is gaining popularity for application in dairy products. Lactic acid bacteria (LAB) play a remarkable role in inhibiting the growth of pathogenic bacteria in food products, without disturbing the sensory attributes of the food. In this study, the screening of the antimicrobial potential of Lactobacillus helveticus KLDS 1.8701 against four food-borne pathogens including Listeria monocytogenes ATCC 19115, Salmonella typhimurium ATCC 14028, Staphylococcus aureus ATCC 25923, and Escherichia coli O157:H7 ATCC 43889 in vitro was inspected using the Oxford cup method and mixed culture inhibition assays. The organic acid production and antimicrobial potential of the cell-free supernatants (CFS) have been evaluated via different treatments and analysis using high performance liquid chromatography (HPLC). The analysis results revealed that KLDS 1.8701 exhibited the highest antimicrobial potential compared to other antimicrobial strains. The antimicrobial activity of KLDS 1.8701 resulted from the organic acids in the culture and CFS. From the study, it was found that carbon sources, as well as organic acid production, accelerate the antimicrobial activity of KLDS 1.8701 and the fructooligosaccharides (FOS) were considered the best for improving the proliferation of KLDS 1.8701 and supporting its antimicrobial action. Results of the mixed culture inhibition assays showed that part of the antimicrobial activity resulted from the inhibitory action of the bacteria itself in culture, and this action required cellular contact between the food-borne pathogens and KLDS 1.8701. Conversely, the results of the antimicrobial spectrum assay revealed that some Lactobacilli remained unaffected by KLDS 1.8701. KLDS 1.8701 might also be favorable for use as a supplementary starter in fermented dairy productions. Furthermore, KLDS 1.8701 could survive well under GI tract conditions

  6. Bactericidal activity of the food color additive Phloxine B against Staphylococcus aureus and other food borne microbial pathogens

    Science.gov (United States)

    The spread of antibiotic resistance among Staphylococcus aureus strains requires the development of new anti S. aureus agents. The objective of this study was evaluating the antimicrobial activity of the food color additive Phloxine B against S. aureus and other food microbial pathogens. Our result ...

  7. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella Typhimurium on Chicken Breast Fillet during Cooking

    NARCIS (Netherlands)

    Jong, de A.E.I.; Asselt, van E.D.; Zwietering, M.H.; Nauta, M.J.; Jonge, de R.

    2012-01-01

    The aim of this research was to determine the decimal reduction times of bacteria present on chicken fillet in boiling water. The experiments were conducted with Campylobacter jejuni, Salmonella, and Escherichia coli. Whole chicken breast fillets were inoculated with the pathogens, stored overnight

  8. Antibacterial activity of selenium-enriched lactic acid bacteria against common food-borne pathogens in vitro.

    Science.gov (United States)

    Yang, Jingpeng; Wang, Jing; Yang, Kun; Liu, Miaomiao; Qi, Yiman; Zhang, Tingjing; Fan, Mingtao; Wei, Xinyuan

    2018-03-01

    Selenium (Se) is an essential trace element for human health and animal nutrition. The aim of this study was to evaluate the inhibitory activities of Se-enriched lactic acid bacteria (LAB), Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus, against pathogenic Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes in vitro. The results indicated that the accumulation amount of Se by Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus reached 12.05 ± 0.43 µg/mL and 11.56 ± 0.25 µg/mL, respectively, accompanied by the relative maximum living cells when sodium selenite was 80 µg/mL. Oxford cup double plate assay showed that bacterial culture solution and cell-free culture supernatant (CFCS) from Se-enriched LAB exerted stronger antibacterial activity than those from the non-Se strains. The growth of pathogenic bacterial culture with CFCS at any growth stages was worse than that without CFCS; moreover, the inhibiting effect of CFCS of Se-enriched LAB was more significant than that of non-Se strains. Results from a scanning electron microscope equipped with energy dispersion X-ray spectrometry showed that elemental Se nanoparticles, which characteristically energy peak around 1.42 keV, were deposited on the cell surfaces of Lactobacillus delbrueckii ssp. bulgaricus. In addition, CFCS of Se-enriched LAB induced more serious cell structure damage of pathogenic bacteria than did non-Se LAB. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. TrpA1 Regulates Defecation of Food-Borne Pathogens under the Control of the Duox Pathway.

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    Eun Jo Du

    2016-01-01

    Full Text Available Pathogen expulsion from the gut is an important defense strategy against infection, but little is known about how interaction between the intestinal microbiome and host immunity modulates defecation. In Drosophila melanogaster, dual oxidase (Duox kills pathogenic microbes by generating the microbicidal reactive oxygen species (ROS, hypochlorous acid (HOCl in response to bacterially excreted uracil. The physiological function of enzymatically generated HOCl in the gut is, however, unknown aside from its anti-microbial activity. Drosophila TRPA1 is an evolutionarily conserved receptor for reactive chemicals like HOCl, but a role for this molecule in mediating responses to gut microbial content has not been described. Here we identify a molecular mechanism through which bacteria-produced uracil facilitates pathogen-clearing defecation. Ingestion of uracil increases defecation frequency, requiring the Duox pathway and TrpA1. The TrpA1(A transcript spliced with exon10b (TrpA1(A10b that is present in a subset of midgut enteroendocrine cells (EECs is critical for uracil-dependent defecation. TRPA1(A10b heterologously expressed in Xenopus oocytes is an excellent HOCl receptor characterized with elevated sensitivity and fast activation kinetics of macroscopic HOCl-evoked currents compared to those of the alternative TRPA1(A10a isoform. Consistent with TrpA1's role in defecation, uracil-excreting Erwinia carotovora showed higher persistence in TrpA1-deficient guts. Taken together, our results propose that the uracil/Duox pathway promotes bacteria expulsion from the gut through the HOCl-sensitive receptor, TRPA1(A10b, thereby minimizing the chances that bacteria adapt to survive host defense systems.

  10. Screening food-borne and zoonotic pathogens associated with livestock practices in the Sumapaz region, Cundinamarca, Colombia

    DEFF Research Database (Denmark)

    Arenas, Nelson E.; Abril, Diego A.; Valencia, Paola

    2017-01-01

    -borne and zoonotic pathogens associated with local livestock practices. We evaluated 1098 cows from 46 livestock farms in the Sumapaz region that were selected by random. Of the total population of cattle, 962 animals (88%) were tested for bovine TB using a caudal-fold tuberculin test and 546 (50%) for brucellosis...... findings suggest that livestock products could be a source of exposure to Brucella and multidrug-resistant E. coli and S. aureus strains as a result of unhygienic livestock practices in the Sumapaz region. Training in good farming practices is the key to improving safety in food production.......Hazardous practices regarding antibiotics misuse, unsanitary milking procedures, and the commercial sales of raw milk and unpasteurized dairy products are currently being practiced by livestock farmers in the Sumapaz region (Colombia). The purpose of this study was to screen for food...

  11. Genome Sequence ofBacillus cereusFORC_021, a Food-Borne Pathogen Isolated from a Knife at a Sashimi Restaurant.

    Science.gov (United States)

    Chung, Han Young; Lee, Kyu-Ho; Ryu, Sangryeol; Yoon, Hyunjin; Lee, Ju-Hoon; Kim, Hyeun Bum; Kim, Heebal; Jeong, Hee Gon; Choi, Sang Ho; Kim, Bong-Soo

    2016-12-28

    Bacillus cereus causes food-borne illness through contaminated foods; therefore, its pathogenicity and genome sequences have been analyzed in several studies. We sequenced and analyzed B. cereus strain FORC_021 isolated from a sashimi restaurant. The genome sequence consists of 5,373,294 bp with 35.36% GC contents, 5,350 predicted CDSs, 42 rRNA genes, and 107 tRNA genes. Based on in silico DNA-DNA hybridization values, B. cereus ATCC 14579 T was closest to FORC_021 among the complete genome-sequenced strains. Three major enterotoxins were detected in FORC_021. Comparative genomic analysis of FORC_021 with ATCC 14579 T revealed that FORC_021 harbored an additional genomic region encoding virulence factors, such as putative ADP-ribosylating toxin, spore germination protein, internalin, and sortase. Furthermore, in vitro cytotoxicity testing showed that FORC_021 exhibited a high level of cytotoxicity toward INT-407 human epithelial cells. This genomic information of FORC_021 will help us to understand its pathogenesis and assist in managing food contamination.

  12. Study on the Chemical Constituents and Antibacterial Activity of Kelussia odoratissima and Teucrium polium Essential Oils against Some Food Borne Pathogens

    Directory of Open Access Journals (Sweden)

    mansour Mashreghi

    2015-05-01

    Full Text Available In this research the essential oils (EOs of Kelussia odoratissima and Teucrium polium were extracted by hydrodistillation. Extracted essential oils constituents were analyzed by gas chromatograph (GC and GC/mass spectrometry and the essential oils constituents identified according to retention time and mass spectrum. Then minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of the essential oils against Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes، Escherichia coli O157H7, Salmonella enterica, and Pseudomonas aureogenosa were determined by microdilution technique using ELISA reader. The results showed that there are differences between the essential oils constituents as the main constituents in Kelussia odoratissima were (Z-ligustilide, (Z-3-butylidene-phthalide, limonene+-phellandren B. The main constituents of Teucrium polium essential oils were β-caryophylene, Germacrene D, γ-cadinene, (Z- nerolidol, camphor, β-pinene, α- camphene, linalool, α-humulene. The MIC of Kelussia odoratissima EO was between 0.31 mg/ml (for S. aureus to 2.5 mg/ml (for Salmonella enterica but MIC of the Teucrium polium EO was between 0.16 mg/ml (for S. aureus and 1.25 mg/ml (for Salmonella enterica. In conclusion, indigenous medicinal plants could be used for effective control of food borne pathogens as a complementary method that has less unfavorable effect on organoleptic attitudes of each products

  13. Antibacterial Activities of Kelussia odoratissima and Teucrium polium Essential Oils in Combination of Synthetic Silver Nanoparticles against Food- borne Pathogens

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    Majid azizi

    2017-02-01

    Full Text Available To study the interaction of silver nanoparticles with antibacterial effects of Kelussia odoratissima and Teucrium polium essential oils consolidated trial based on calculation of MIC and FIC index or differential inhibitory concentration and simple method checkboard designed and implemented. Essential oil of the plants extracted by hydro-distillation using clevenger apparatus. In this study, common food contaminant bacteria such as Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Escherichia coli O157: H7, Salmonella enterica and Ps. aureogenosa were used. The results showed that the antibacterial properties of the essential oil of Teucrium is stronger (MIC between 0.16 to 1.25 mg/ ml than of the oil of Kelussia (MIC between 0.3 to 2.5 mg/ml. Antibacterial properties of silver nanoparticles (MIC between 0.006 to 0.025 mg were stronger significantly. Calculate the differential inhibitory concentration index (FICi implies the existence of synergistic and additive effect between silver nanoparticles and oil of both plant which will depend on the type of pathogen. This means that the combined use of silver nanoparticles and essential oil of the plant especially Teucrium essential oils strong inhibitory effect with lower concentrations of the essential oils was observed. Antagonistic interaction between silver nanoparticles and oil treatments in any of these two plants were observed.

  14. Multiplex detection of nine food-borne pathogens by mPCR and capillary electrophoresis after using a universal pre-enrichment medium

    Science.gov (United States)

    Villamizar-Rodríguez, Germán; Fernández, Javier; Marín, Laura; Muñiz, Juan; González, Isabel; Lombó, Felipe

    2015-01-01

    Routine microbiological quality analyses in food samples require, in some cases, an initial incubation in pre-enrichment medium. This is necessary in order to ensure that small amounts of pathogenic strains are going to be detected. In this work, a universal pre-enrichment medium has been developed for the simultaneous growth of Bacillus cereus, Campylobacter jejuni, Clostridium perfringens, Cronobacter sakazakii, Escherichia coli, Enterobacteriaceae family (38 species, 27 genera), Listeria monocytogenes, Staphylococcus aureus, Salmonella spp. (two species, 13 strains). Growth confirmation for all these species was achieved in all cases, with excellent enrichments. This was confirmed by plating on the corresponding selective agar media for each bacterium. This GVUM universal pre-enrichment medium could be useful in food microbiological analyses, where different pathogenic bacteria must be detected after a pre-enrichment step. Following, a mPCR reaction for detection of all these pathogens was developed, after designing a set of nine oligonucleotide pairs from specific genetic targets on gDNA from each of these bacteria, covering all available strains already sequenced in GenBank for each pathogen type. The detection limits have been 1 Genome Equivalent (GE), with the exception of the Fam. Enterobacteriaceae (5 GEs). We obtained amplification for all targets (from 70 to 251 bp, depending on the bacteria type), showing the capability of this method to detect the most important industrial and sanitary food-borne pathogens from a universal pre-enrichment medium. This method includes an initial pre-enrichment step (18 h), followed by a mPCR (2 h) and a capillary electrophoresis (30 min); avoiding the tedious and long lasting growing on solid media required in traditional analysis (1–4 days, depending on the specific pathogen and verification procedure). An external testing of this method was conducted in order to compare classical and mPCR methods. This evaluation was

  15. Multiplex detection of nine food-borne pathogens by mPCR and capillary electrophoresis after using a universal pre-enrichment medium

    Directory of Open Access Journals (Sweden)

    Germán eVillamizar-Rodríguez

    2015-11-01

    Full Text Available Routine microbiological quality analyses in food samples require, in some cases, an initial incubation in pre-enrichment medium. This is necessary in order to assure that small amounts of pathogenic strains are going to be detected. In this work, a universal pre-enrichment medium has been developed for simultaneous growth of Bacillus cereus, Campylobacter jejuni, Clostridium perfringens, Cronobacter sakazakii, Escherichia coli, Enterobacteriaceae family (thirty eight species, twenty seven genera, Listeria monocytogenes, Staphylococcus aureus, Salmonella spp. (two species, thirteen strains. Growth confirmation for all these species was achieved in all cases, with excellent enrichments. This was confirmed by plating on the corresponding selective agar media for each bacterium. This GVUM universal pre-enrichment medium could be useful in food microbiological analyses, where different pathogenic bacteria must be detected after a pre-enrichment step. Following, a mPCR reaction for detection of all these pathogens was developed, after designing a set of nine oligonucleotide pairs from specific genetic targets on gDNA from each of these bacteria, covering all available strains already sequenced in GenBank for them. The detection limits have been 1 Genome Equivalent, with the exception of Fam. Enterobacteriaceae (5 GEs. We obtained amplification for all targets (from 70 to 251 bp, depending on the bacteria type, showing the capability of this method to detect the most important industrial and sanitary food-borne pathogens from a universal pre-enrichment medium. This method includes an initial pre-enrichment step (18 h, followed by a mPCR (2 h and a capillary electrophoresis (30 min; avoiding the tedious and long lasting growing on solid media required in traditional analysis (1 to 4 days, depending on the specific pathogen and verification procedure. An external testing of this method was conducted in order to compare classical and mPCR methods. This

  16. The influence of the cell free solution of lactic acid bacteria on tyramine production by food borne-pathogens in tyrosine decarboxylase broth.

    Science.gov (United States)

    Toy, Nurten; Özogul, Fatih; Özogul, Yesim

    2015-04-15

    The function of cell-free solutions (CFSs) of lactic acid bacteria (LAB) on tyramine and other biogenic amine production by different food borne-pathogens (FBPs) was investigated in tyrosine decarboxylase broth (TDB) using HPLC. Cell free solutions were prepared from four LAB strains. Two different concentrations which were 50% (5 ml CFS+5 ml medium/1:1) and 25% (2.5 ml CFS+7.5 ml medium/1:3) CFS and the control without CFS were prepared. Both concentration of CFS of Streptococcus thermophilus and 50% CFS of Pediococcus acidophilus inhibited tyramine production up to 98% by Salmonella paratyphi A. Tyramine production by Escherichia coli was also inhibited by 50% CFS of Lactococcus lactis subsp. lactis and 25% CFS of Leuconostoc lactis. subsp. cremoris. The inhibitor effect of 50% CFS of P. acidophilus was the highest on tyramine production (55%) by Listeria monocytogenes, following Lc. lactis subsp. lactis and Leuconostoc mesenteroides subsp. cremoris (20%) whilst 25% CFS of Leu. mes. subsp. cremoris and Lc. lactis subsp. lactis showed stimulator effects (160%). The stimulation effects of 50% CFS of S. thermophilus and Lc. lactis subsp. lactis were more than 70% by Staphylococcus aureus comparing to the control. CFS of LAB strains showed statistically inhibitor effect since lactic acid inhibited microbial growth, decreased pH quickly and reduced the formation of AMN and BAs. Consequently, in order to avoid the formation of high concentrations of biogenic amines in fermented food by bacteria, it is advisable to use CFS for food and food products. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Evaluation of antibacterial effect of Rosmarinus officinalis L. essential oil on three food-borne pathogens in vegetables by propidium monoazide quantitative PCR

    Directory of Open Access Journals (Sweden)

    M Azizkhani

    2015-08-01

    Full Text Available Essential oils (EOs have long been applied as flavoring agents in foods. Nowadays, due to the antimicrobial properties of EOs, they have been used as natural food preservatives. In this study, initial experiments were performed in order to elucidate the minimum bactericidal concentration of Rosmarinus officinalis L.EO on Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes. Thereafter, PMA-qPCR was applied in order to selectively quantify living cells within a bacterial population treated with rosemary EO. Inactivation was obtained at EO concentrations of 1%, 0.45%, 0.9% for L. monocytogenes, E. coli O157:H7 and S. enterica, respectively. L. monocytogenes were totally killed within 45 min while it took 90 min for E. coli O157:H7and S. enterica. It was concluded that rosemary EO has the potential to be used as a natural food additive or bio-preservative since it was able to irreversibly inactivate the three tested pathogens at lower concentrations and short exposition times in comparison with the other EOs. In addition, PMA-qPCR approach proved quantitatively precise and specific to selectively detect live pathogenic bacteria in vegetables following inactivation with rosemary EO.

  18. Antibacterial Activity of Clove ( Syzigium aromaticum L .) Essential Oil and Gamma Irradiation against Some Food-Borne Pathogens in Minced Chicken Meat

    International Nuclear Information System (INIS)

    Gibriel, A.Y.; ALI, H.G.M.; Abdeldaiem, M.H.

    2017-01-01

    Antibacterial activity of clove essential oil ( Syzigium aromaticum L.) against five strains of pathogenic bacteria namely, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli and Bacillus cereus was investigated in vitro. The essential oil of clove exhibited antibacterial activity against tested microorganisms. Comparatively, 25, 50 and 100 ml/l concentrations of clove essential oil were of less inhibitory effect than 200, 300 and 500 ml/l concentrations. However, S. aureus showed less sensitivity towards clove essential oil inhibition; however Salmonella typhimurium was strongly inhibited by clove essential oil. Then, the effect of clove essential oil at two concentrations (3 and 5% v/w) and combined treatments between gamma irradiation at doses of 1, 2, 3, 4, 5 and 6 kGy and clove essential oil at concentrations as formerly on inactivation of Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhimurium , Escherichia coli and Bacillus cereus inoculated into chicken minced meat was investigated. Addition of clove essential oil to samples of chicken minced meat inoculated with three pathogens reduced the counts of these pathogens, proportionally with increasing concentration. The irradiated samples at doses of 3, 4, 5 and 6 kGy and that irradiated at doses 2, 3, 4, 5 and 6 kGy of chicken minced and containing 3 and 5% completely inactivation of inoculated pathogens and not detected during cold storage at 4±1°C for 7 days. Accordingly, clove essential oil can be used as natural antimicrobial additive or in combination treatments with gamma irradiation for incorporation in various food products. Also, there is a possibility of using low doses gamma irradiation and low concentrations clove essential oil for treatment of meat products in order to this to reduce the economic cost of products and improving hygienic quality and extend its shelf-life. Therefore clove essential oil could be used as preservative ingredients in

  19. [Antibacterial actin of vinegar against food-borne pathogenic bacteria including Escherichia coli O157:H7 (Part 2). Effect of sodium chloride and temperature on bactericidal activity].

    Science.gov (United States)

    Entani, E; Asai, M; Tsujihata, S; Tsukamoto, Y; Ohta, M

    1997-05-01

    Bactericidal effects of various kinds of AWASEZU (processed vinegar, 2.5% acidity) on food-borne pathogenic bacteria including Escherichia coli O157:H7 and other bacteria were examined. the order of bactericidal activities was NIHAIZU (3.5% NaCl was added) > SANBA-IZU (3.5% NaCl and 10% sucrose were added) > plain vinegar (spirit vinegar) > AMAZU (10% sucrose was added). This indicates that their activities were enhanced by the addition of sodium chloride and suppressed by the addition of sugar. On the other hand, when soy sauce was used instead of sodium chloride, the order of bactericidal activities was plain vinegar > AMAZU > NIHAIZU > SANBAIZU. This is mainly because their activities were suppressed by the increase in the pH value. The effect of sodium chloride (0.01-15%) and temperature (10-50 degrees C) on bactericidal activities against E. coli O157:H7 in spirit vinegar (0.5-2.5% acidity) was further examined. When vinegar was used in combination with sodium chloride, predominant synergism on the bactericidal activity was observed. Their activities were markedly enhanced by the addition of sodium chloride in proportion to the concentration. In addition to this, at higher temperatures spirit vinegar killed bacteria much more rapidly. It should be noted that the bactericidal activity of spirit vinegar was extremely enhanced by the combined use of the addition of sodium chloride and the rise of temperature. For example, in 2.5% acidity vinegar, the time required for 3 log decrease in viable cell numbers at 20 degrees C was shortened to 1/140-fold by the addition of 5% sodium chloride, shortened to 1/51-fold by the rise of the reaction temperature at 40 degrees C, and shortened to 1/830-fold; 0.89 minutes by both the addition of 5% sodium chloride and the rise of temperature at 40 degrees C. In order to propose the methods to prevent food poisoning by bacterial infection, bactericidal activities of vinegar solution containing sodium chloride on cooking tools and

  20. Future perspectives, applications and challenges of genomic epidemiology studies for food-borne pathogens: A case study of Enterohemorrhagic Escherichia coli (EHEC) of the O157:H7 serotype.

    Science.gov (United States)

    Eppinger, Mark; Cebula, Thomas A

    2015-01-01

    The shiga-toxin (Stx)-producing human pathogen Escherichia coli serotype O157:H7 is a highly pathogenic subgroup of Stx-producing E. coli (STEC) with food-borne etiology and bovine reservoir. Each year in the U. S., approximately 100,000 patients are infected with enterohemorrhagic E. coli (EHEC) of the O157:H7 serotype. This food-borne pathogen is a global public health threat responsible for widespread outbreaks of human disease. Since its initial discovery in 1982, O157:H7 has rapidly become the dominant EHEC serotype in North America. Hospitalization rates among patients as high as 50% have been reported for severe outbreaks of human disease. Symptoms of disease can rapidly deteriorate and progress to life-threatening complications such as Hemolytic Uremic Syndrome (HUS), the leading cause of kidney failure in children, or Hemorrhagic Colitis. In depth understanding of the genomic diversity that exists among currently circulating EHEC populations has broad applications for improved molecular-guided biosurveillance, outbreak preparedness, diagnostic risk assessment, and development of alternative toxin-suppressing therapeutics.

  1. Mycobacterium avium subspecies paratuberculosis - an important food borne pathogen of high public health significance with special reference to India: an update.

    Science.gov (United States)

    Chaubey, Kundan Kumar; Singh, Shoor Vir; Gupta, Saurabh; Singh, Manju; Sohal, Jagdip Singh; Kumar, Naveen; Singh, Manoj Kumar; Bhatia, Ashok Kumar; Dhama, Kuldeep

    2017-12-01

    This review underlines the public health significance of 'Indian Bison Type' of Mycobacterium avium subspecies paratuberculosis (MAP) and also its potential as 'zoonotic infection'. In the absence of control programs, bio-load of MAP is increasing and if we take total population of animals (500 million plus) and human beings (1.23 billion plus) into account, the number of infected animals and human beings will run into millions in India. Our research on screening of over 26,000 domestic livestock for MAP infection using 4 different diagnostic tests (microscopy, culture, ELISA and PCR), during last 31 years has shown that the average bio-load of MAP in the livestock population of India is very high (cattle 43%, buffaloes 36%, goats 23% and sheep 41%). 'Mass screening' of 28,291 human samples between 2008-2016 revealed also high bio-load of MAP. It has been proved that MAP is not in-activated during pasteurization and therefore live bacilli are continuously reaching human population by consumption of even pasteurized milk and other milk products. Live bacilli have also been recovered from meat products and the environment thus illustrating the potential of MAP as pathogen of public health concern. However, at present, there is inadequate scientific evidence to confirm a conclusive link between MAP infection and Johne's disease in ruminants and some cases of Crohn's disease in human beings.

  2. 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...

  3. 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.

  4. Enterococcus faecalis and pathogenic streptococci inactivate daptomycin by releasing phospholipids.

    Science.gov (United States)

    Ledger, Elizabeth V K; Pader, Vera; Edwards, Andrew M

    2017-10-01

    Daptomycin is a lipopeptide antibiotic with activity against Gram-positive bacteria. We showed previously that Staphylococcus aureus can survive daptomycin exposure by releasing membrane phospholipids that inactivate the antibiotic. To determine whether other pathogens possess this defence mechanism, phospholipid release and daptomycin activity were measured after incubation of Staphylococcus epidermidis, group A or B streptococci, Streptococcus gordonii or Enterococcus faecalis with the antibiotic. All bacteria released phospholipids in response to daptomycin, which resulted in at least partial inactivation of the antibiotic. However, E. faecalis showed the highest levels of lipid release and daptomycin inactivation. As shown previously for S. aureus, phospholipid release by E. faecalis was inhibited by the lipid biosynthesis inhibitor platensimycin. In conclusion, several pathogenic Gram-positive bacteria, including E. faecalis, inactivate daptomycin by releasing phospholipids, which may contribute to the failure of daptomycin to resolve infections caused by these pathogens.

  5. Invitro Evaluation Of Antibacterial Activity Of Lactic Acid Bacteria Isolated From Ergo And Qotchqotcha Ethiopian Traditional Fermented Foods Against Some Selected Food Borne Pathogens

    Directory of Open Access Journals (Sweden)

    Lamenew Fenta

    2017-09-01

    Full Text Available The prevention of pathogenic bacteria by lactic acid bacteria LAB isolated directly from foods is an innovative approach. With the aim of determining the anti-bacterial activity of Lactic acid bacteria isolated from ergo and qotchqotcha Ethiopian fermented food 12 samples of each were taken from the 4 different kebeles of Assosa town. Isolation of LAB from the selected samples were carried out using MRS media. The different set of isolates were characterized using primary biochemical tests. Isolates which were gram positive catalase negative and KOH negative were considered to be presumptive LAB and further characterized by using different biochemical tests for further identification. 16 isolates from ergo samples were isolated. Based on Bergeys manual of determinative bacteriology the 16 isolates belonged to four 4 LAB species namely Lactobacillus acidophilus 18.75 Lactobacillus casei 31.25 Streptococcus thermophiles 25 and Lactobacillus bulgaricus 25. Likewise 5 isolates were isolated from Qotchqotcha and the five isolates were found to be Lactobacillus acidophilus 80 and Pediococcus acidilactici 20. Cell free solution from MRS broth culture of theses LAB was prepared and tested against Escherichia coli O157H7 and Staphylococcus aureus using agar-well diffusion method. Of the 16 isolates isolated from ergo 9 of them show antimicrobial activity against E. coli O157H7 with a largest inhibition zone measured about 7.331.20mm by EK0101 and 12 of them show antimicrobial activity against S. aureus with a largest inhibition zone measured about 11.66 0.88mm by EK0201. On the basis of morphological and biochemical test done EK0101 was found to be presumptive Lactobacillus acidophilus and EK0201 to be Streptococcus thermophiles. All of the isolates isolated from Qotchqotcha showed antimicrobial activity against the tested organisms though there was a significant difference in their activity P0.05. The isolate QK0201 showed an inhibition zone of about 6

  6. Growth and membrane fluidity of food-borne pathogen Listeria monocytogenes in the presence of weak acid preservatives and hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Ioannis eDiakogiannis

    2013-06-01

    Full Text Available This study addresses a major issue in microbial food safety, the elucidation of correlations between acid stress and changes in membrane fluidity of the pathogen Listeria monocytogenes. In order to assess the possible role that membrane fluidity changes play in L. monocytogenes tolerance to antimicrobial acids (acetic, lactic, hydrochloric acid at low pH or benzoic acid at neutral pH, the growth of the bacterium and the gel-to-liquid crystalline transition temperature point (Tm of cellular lipids of each adapted culture was measured and compared with unexposed cells. The Tm of extracted lipids was measured by Differential Scanning Calorimetry (DSC. A trend of increasing Tm values but not of equal extent was observed upon acid tolerance for all samples and this increase is not directly proportional to each acid antibacterial action. The smallest increase in Tm value was observed in the presence of lactic acid, which presented the highest antibacterial action. In the presence of acids with high antibacterial action such as acetic, hydrochloric acid or low antibacterial action such as benzoic acid, increased Tm values were measured. The Tm changes of lipids were also correlated with our previous data about fatty acid changes to acid adaptation. The results imply that the fatty acid changes are not the sole adaptation mechanism for decreased membrane fluidity (increased Tm. Therefore, this study indicates the importance of conducting an in-depth structural study on how acids commonly used in food systems affect the composition of individual cellular membrane lipid molecules.

  7. Essential oils as antibacterial agents against food-borne pathogens: Are they really as useful as they are claimed to be?

    Science.gov (United States)

    Santos, M I S; Martins, S R; Veríssimo, C S C; Nunes, M J C; Lima, A I G; Ferreira, R M S B; Pedroso, L; Sousa, I; Ferreira, M A S S

    2017-12-01

    Most studies evaluating the use of essential oils (EO) as antibacterial agents focus mainly on minimal inhibitory concentrations (MIC) rather than minimal bactericidal concentrations (MBC). In this work, we compared MICs and MBCs of EO from condiment plants commonly used in Mediterranean Europe, namely Origanum vulgare , Salvia lavandulaefolia , Salvia officinalis , Salvia sclarea and Rosmarinus officinalis , aiming to evaluate their application as disinfecting agents in minimally processed produce. Outbreaks-related pathogens such as Listeria monocytogenes , Pseudomonas aeruginosa and Yarrowia lipolytica were used. Results showed that all EO were able to reduce bacterial growth in all bacterial strains tested, particularly O. vulgare . However, fewer EO exhibited bactericidal activities, and were only effective against one or two bacterial strains, hence eliminating the possibility to use them as broad range disinfectants. Furthermore, the necessary concentrations were too high for food application. Hence, our work suggests the need to evaluate MBC rather than MIC and questions EO usefulness in controlling undesired microorganisms. Overall, and despite the large volume of data published on EO, results obtained were not very encouraging for a realistic application on produce and question the viability of EOs as disinfecting agents in food.

  8. Growth and membrane fluidity of food-borne pathogen Listeria monocytogenes in the presence of weak acid preservatives and hydrochloric acid.

    Science.gov (United States)

    Diakogiannis, Ioannis; Berberi, Anita; Siapi, Eleni; Arkoudi-Vafea, Angeliki; Giannopoulou, Lydia; Mastronicolis, Sofia K

    2013-01-01

    This study addresses a major issue in microbial food safety, the elucidation of correlations between acid stress and changes in membrane fluidity of the pathogen Listeria monocytogenes. In order to assess the possible role that membrane fluidity changes play in L. monocytogenes tolerance to antimicrobial acids (acetic, lactic, hydrochloric acid at low pH or benzoic acid at neutral pH), the growth of the bacterium and the gel-to-liquid crystalline transition temperature point (T m) of cellular lipids of each adapted culture was measured and compared with unexposed cells. The T m of extracted lipids was measured by differential scanning calorimetry. A trend of increasing T m values but not of equal extent was observed upon acid tolerance for all samples and this increase is not directly proportional to each acid antibacterial action. The smallest increase in T m value was observed in the presence of lactic acid, which presented the highest antibacterial action. In the presence of acids with high antibacterial action such as acetic, hydrochloric acid or low antibacterial action such as benzoic acid, increased T m values were measured. The T m changes of lipids were also correlated with our previous data about fatty acid changes to acid adaptation. The results imply that the fatty acid changes are not the sole adaptation mechanism for decreased membrane fluidity (increased T m). Therefore, this study indicates the importance of conducting an in-depth structural study on how acids commonly used in food systems affect the composition of individual cellular membrane lipid molecules.

  9. Chemical composition and in vitro antibacterial activity of essential oil and methanol extract of Echinophora platyloba D.C against some of food-borne pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Mohammad Hashemi

    2013-06-01

    Full Text Available Echinophora Platyloba D.C as a medicinal plant is used for preservation of foods and treatment of many diseases in different regions of Iran. The present study was undertaken to determine the chemical composition and investigation of the antibacterial effects of essential oil as well as methanol extract from aerial part of Echinophora Platyloba D.C against S. aureus, L. monocytogenes, S. Thyphimurium and E. coli. Chemical analysis using gas chromatography and mass spectrophotometry (GC/MS showed that ocimene (26.51%, 2,3-Dimethyl-cyclohexa- 1,3-diene (9.87%, alpha-pinene (7.69% and gamma-dodecanolactone (5.66% were dominant components of essential oil and the main constituents of methanol extract were o- Cymene (28.66%, methanol (8.50%, alpha-pinene (7.42% and gamma-decalactone (5.20%. The essential oil showed strong antimicrobial activity against tested bacteria, whereas the methanol extract almost remained inactive against gram-negative bacteria. The most sensitive bacteria to essential oil and extract of Echinophora Platyloba D.C were L. mono- cytogenes and S. aureus. Minimum inhibitory concentration (MIC values of essential oil against L. monocytogenes and S. aureus were 6250 and 12500 ppm, respectively. MIC of methanol extract against S. aureus and L. monocytogenes was 25000 ppm. Therefore, purifying and evaluation of antibacterial effects of the active substances of the essential oil and methanol extract of this plant for future application as antibacterial agents and food preservatives to combat pathogenic and toxigenic microorganisms is recommended.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. Food-borne diseases - the challenges of 20 years ago still persist while new ones continue to emerge.

    NARCIS (Netherlands)

    Newell, D.G.; Koopmans, M.; Verhoef, L.; Duizer, E.; Aidara-Kane, A.; Sprong, H.|info:eu-repo/dai/nl/222364815; Opsteegh, M.|info:eu-repo/dai/nl/31149305X; Langelaar, M.; Threfall, J.; Scheutz, F.; van der Giessen, J.; Kruse, H.

    2010-01-01

    The burden of diseases caused by food-borne pathogens remains largely unknown. Importantly data indicating trends in food-borne infectious intestinal disease is limited to a few industrialised countries, and even fewer pathogens. It has been predicted that the importance of diarrhoeal disease,

  16. 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.

  17. 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.

  18. 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.

  19. Difficulties in Diagnosing Food-Borne Botulism

    Directory of Open Access Journals (Sweden)

    Nina Forss

    2012-06-01

    Full Text Available Botulism is a muscle-paralyzing disease caused by neurotoxins (types A–G produced by the bacteria Clostridium botulinum. Symptoms of food-borne botulism most commonly appear 12–36 h after eating contaminated food, but the earliest neurological symptoms may in some cases start abruptly. Here, we report the cases of two patients with food-borne botulism who were admitted to the neurological emergency room as candidates for intravenous thrombolysis for acute stroke.

  20. 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.

  1. From ontology selection and semantic web to the integrated information system of food-borne diseases and food safety

    Science.gov (United States)

    Over the last three decades, the rapid explosion of information and resources on human food-borne diseases and food safety has provided the ability to rapidly determine and interpret the mechanisms of survival and pathogenesis of food-borne pathogens. However, several factors have hindered effective...

  2. Food-borne bacteremic illnesses in febrile neutropenic children

    Directory of Open Access Journals (Sweden)

    Anselm Chi-wai Lee

    2011-08-01

    Full Text Available Bacteremia following febrile neutropenia is a serious complication in children with malignancies. Preventive measures are currently targeted at antimicrobial prophylaxis, amelioration of drug-induced neutropenia, and nosocomial spread of pathogens, with little attention to community-acquired infections. A retrospective study was conducted at a pediatric oncology center during a 3-year period to identify probable cases of food-borne infections with bacteremia. Twenty-one bacteremic illnesses affecting 15 children receiving chemotherapy or hematopoietic stem cell transplantation were reviewed. Three (14% episodes were highly suspected of a food-borne origin: a 17-year-old boy with osteosarcoma contracted Sphingomonas paucimobilis septicemia after consuming nasi lemak bought from a street hawker; a 2-year-old boy with acute lymphoblastic leukemia developed Chryseobacterium meningosepticum septicemia after a sushi dinner; a 2-year-old girl was diagnosed with acute lymphoblastic leukemia and Lactobacillus bacteremia suspected to be of probiotic origin. All of them were neutropenic at the time of the infections and the bacteremias were cleared with antibiotic treatment. Food-borne sepsis may be an important, but readily preventable, cause of bloodstream infections in pediatric oncology patients, especially in tropical countries with an abundance of culinary outlets.

  3. 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

  4. 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 (PL. rhamnosus yoba grew from 5.5 ± 0.1 log cfu/mL to 9.1 ± 0.4 log cfu/mL in the presence of pathogens. The pH of yoba mutandabota dropped from 4.2 ± 0.1 to 3.3 ± 0.1 after 24h of fermentation, 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

  5. Potential and limitation of UVC irradiation for the inactivation of pathogens in platelet concentrates

    NARCIS (Netherlands)

    Terpstra, Fokke G.; van 't Wout, Angélique B.; Schuitemaker, Hanneke; van Engelenburg, Frank A. C.; Dekkers, David W. C.; Verhaar, Robin; de Korte, Dirk; Verhoeven, Arthur J.

    2008-01-01

    BACKGROUND: Pathogen contamination, causing transfusion-transmitted diseases, is an ongoing concern in transfusion of cellular blood products. In this explorative study, the pathogen-inactivating capacity of UVC irradiation in platelet (PLT) concentrates was investigated. The dose dependencies of

  6. Immobilization with Metal Hydroxides as a Means To Concentrate Food-Borne Bacteria for Detection by Cultural and Molecular Methods†

    OpenAIRE

    Lucore, Lisa A.; Cullison, Mark A.; Jaykus, Lee-Ann

    2000-01-01

    The application of nucleic acid amplification methods to the detection of food-borne pathogens could be facilitated by concentrating the organisms from the food matrix before detection. This study evaluated the utility of metal hydroxide immobilization for the concentration of bacterial cells from dairy foods prior to detection by cultural and molecular methods. Using reconstituted nonfat dry milk (NFDM) as a model, two food-borne pathogens (Listeria monocytogenes and Salmonella enterica sero...

  7. Effect of Activated Plastic Films on Inactivation of Foodborne Pathogens

    Directory of Open Access Journals (Sweden)

    Belén Soriano Cuadrado

    2016-07-01

    Full Text Available In the present study, low density polyethylene films were activated by co-extrusion with zinc oxide, zinc acetate or potassium sorbate. Films were also surface-activated with tyrosol singly or in combination with lactic acid or p-hydroxybenzoic acid. Activated films were tested on Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Salmonella enterica and Pseudomonas fluorescens. The combinations showing greatest inhibition zones and broadest inhibitory spectrum were the films activated with tyrosol plus p-hydroxybenzoic acid. A small delay in growth of Listeria innocua was observed on seabream packed in ZnO-activated films during refrigerated storage for 7 days. When films activated with 2.5% tyrosol or with 1.5% tyrosol plus 0.5 p-hydroxybenzoic acid were used for vacuum packaging of smoked salmon and smoked tuna challenged with cocktails of S. enterica and L. monocytogenes strains, the combination of tyrosol and p-hydroxybenzoic acid improved inactivation of both pathogens during chill storage compared to films singly activated with tyrosol. The best results were obtained in smoked salmon, since no viable pathogens were detected after 7 days of chill storage for the activated film. Results from the study highlight the potential of plastic films surface-activated with tyrosol and p-hydroxybenzoic acid in the control of foodborne pathogens in smoked seafood.

  8. Human sparganosis, a neglected food borne zoonosis.

    Science.gov (United States)

    Liu, Quan; Li, Ming-Wei; Wang, Ze-Dong; Zhao, Guang-Hui; Zhu, Xing-Quan

    2015-10-01

    Human sparganosis is a food borne zoonosis caused by the plerocercoid larvae (spargana) of various diphyllobothroid tapeworms of the genus Spirometra. Human infections are acquired by ingesting the raw or undercooked meat of snakes or frogs, drinking untreated water, or using raw flesh in traditional poultices. More than 1600 cases of sparganosis have been documented worldwide, mostly in east and southeast Asia. Sporadic cases have been reported in South America, Europe, and Africa, and several cases have been described in travellers returning from endemic regions. Epidemiological data suggest that the increased effect of sparganosis on human health is because of greater consumption of raw meat of freshwater frogs and snakes. This Review provides information about the Spirometra parasites and their lifecycles, summarises clinical features, diagnosis, and treatment of human sparganosis, and describes geographical distribution and infection characteristics of Spirometra parasites in host animals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Detection and Identification of Common Food-Borne Viruses with a Tiling Microarray

    OpenAIRE

    Chen, Haifeng; Mammel, Mark; Kulka, Mike; Patel, Isha; Jackson, Scott; Goswami, Biswendu B.

    2011-01-01

    Microarray hybridization based identification of viral genotypes is increasingly assuming importance due to outbreaks of multiple pathogenic viruses affecting humans causing wide-spread morbidity and mortality. Surprisingly, microarray based identification of food-borne viruses, one of the largest groups of pathogenic viruses, causing more than 1.5 billion infections world-wide every year, has lagged behind. Cell-culture techniques are either unavailable or time consuming for routine applicat...

  10. 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

  11. Quercetin Influences Quorum Sensing in Food Borne Bacteria: In-Vitro and In-Silico Evidence.

    Directory of Open Access Journals (Sweden)

    Venkadesaperumal Gopu

    Full Text Available Quorum sensing (QS plays a vital role in regulating the virulence factor of many food borne pathogens, which causes severe public health risk. Therefore, interrupting the QS signaling pathway may be an attractive strategy to combat microbial infections. In the current study QS inhibitory activity of quercetin and its anti-biofilm property was assessed against food-borne pathogens using a bio-sensor strain. In addition in-silico techniques like molecular docking and molecular dynamics simulation studies were applied to screen the quercetin's potentiality as QS inhibitor. Quercetin (80 μg/ml showed the significant reduction in QS-dependent phenotypes like violacein production, biofilm formation, exopolysaccharide (EPS production, motility and alginate production in a concentration-dependent manner. Synergistic activity of conventional antibiotics with quercetin enhanced the susceptibility of all tested pathogens. Furthermore, Molecular docking analysis revealed that quercetin binds more rigidly with LasR receptor protein than the signaling compound with docking score of -9.17 Kcal/mol. Molecular dynamics simulation predicted that QS inhibitory activity of quercetin occurs through the conformational changes between the receptor and quercetin complex. Above findings suggest that quercetin can act as a competitive inhibitor for signaling compound towards LasR receptor pathway and can serve as a novel QS-based antibacterial/anti-biofilm drug to manage food-borne pathogens.

  12. The impact of food manufacturing practices on food borne diseases

    Directory of Open Access Journals (Sweden)

    Cristina Paiva de Sousa

    2008-08-01

    Full Text Available Food-borne illness is a major international problem and an important cause of reduced economic growth. The contamination of the food supply with the pathogens and its persistence, growth, multiplication and/or toxin production has emerged as an important public health concern. Most of these problems could be controlled with the efforts on the part of the food handlers, whether in a processing plant, a restaurant, and others. In contrast with most chemical hazardous compounds, the concentration of food pathogens changes during the processing, storage, and meal preparation, making it difficult to estimate the number of the microorganisms or the concentration of their toxins at the time of ingestion by the consumer. This review shows main microorganisms related to the manipulation practices such as Staphylococcus spp., Escherichia coli and Salmonella spp. and describes the factors regarding the food-borne illness highlighting the impact of good manipulation practices on the food safety and food quality.Doenças veiculadas por alimentos são um dos maiores problemas de Saúde Pública no mundo, sendo responsáveis por reduções no crescimento econômico global. A contaminação de alimentos com patógenos e sua persistência, crescimento, multiplicação e/ou produção de toxinas é de interesse da Saúde Pública. Estes problemas podem ser controlados com esforços e treinamento constante de manipuladores de alimentos. Em contraste com perigos químicos e físicos, a concentração de patógenos em alimentos é modificada durante etapas de processamento, acondicionamento e preparação, tornando difícil estimar e quantificar o número de microrganismos ou a concentração de suas toxinas no momento da ingestão do alimento. Esta revisão comenta sobre os principais microrganismos bacterianos relacionados à práticas de manipulação como Staphylococcus spp., Escherichia coli e Salmonella spp. ressaltando o consumo de alimentos em ruas, o

  13. Food-borne disease outbreaks due to bacteria in Taiwan, 1986 to 1995.

    OpenAIRE

    Pan, T M; Wang, T K; Lee, C L; Chien, S W; Horng, C B

    1997-01-01

    Between 1986 and 1995, 852 outbreaks of food-borne disease involving 26,173 cases and 20 deaths were reported in Taiwan. About 80% of the outbreaks occurred in the warmer months, i.e., between April and October. Of the 852 reported outbreaks, 555 (65%) were caused by bacterial pathogens. The three most common bacteria involved were Vibrio parahaemolyticus (35%, 197 of 555 outbreaks), Staphylococcus aureus (30%, 169 of 555 outbreaks), and Bacillus cereus (18%, 104 of 555 outbreaks).

  14. 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.

  15. 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.

  16. 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 ...

  17. 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 eva...

  18. Knowledge of Brucella as a food-borne pathogen

    Science.gov (United States)

    Although Brucella spp. are known for causing reproductive losses in domestic livestock, they are also capable of infecting humans and causing clinical disease. Human infection with Brucella is almost exclusively a result of direct contact with infected animals or consumption of products made from un...

  19. Raising the Level of Analysis of Food-Borne Outbreaks

    Science.gov (United States)

    Trostle, James A.; Hubbard, Alan; Scott, James; Cevallos, William; Bates, Sarah J.; Eisenberg, Joseph N. S.

    2009-01-01

    Objectives Consuming contaminated food is a well-documented individual-level risk factor for diarrheal disease. The sharing of food also influences the distribution of diarrheal disease risk through a community and region. Understanding this social process at a population level is therefore an important dimension of risk not captured by standard individual-level analyses. We examined social networks related to food-sharing in rural villages at 2 scales: within a village, examining whether connections within these networks clustered or were uniformly spread; and among villages, looking at whether food-sharing networks differed according to the village’s remoteness from a population center. Methods We surveyed 2129 individuals aged 13 years and older in 2003–2004, within a representative (block-randomized) sample of 21 rural villages in Esmeraldas province, northern coastal Ecuador. We calculated degree (number of social contacts) for a social network defined by sharing food. Results Networks of households sharing food differ according to remoteness from a metropolitan center. On average, residents living in “far villages” had 2 more social contacts than those in “close villages,” and 12 more years of residence in their village. Estimates of transmissibility (a measure of outbreak potential) based on network structure varied as much as 2-fold across these villages. Conclusions Food-sharing practices link particular households in rural villages and have implications for the spread of food-borne pathogens. The food-sharing networks in remote rural villages are heterogeneous and clustered, consistent with contemporary theories about disease transmitters. Network-based measures may offer tools for predicting patterns of disease outbreaks, as well as guidance for interventions. PMID:18379421

  20. Atmospheric plasma inactivation of foodborne pathogens on fresh produce surfaces.

    Science.gov (United States)

    Critzer, Faith J; Kelly-Wintenberg, Kimberly; South, Suzanne L; Golden, David A

    2007-10-01

    A study was conducted to determine the effect of one atmosphere uniform glow discharge plasma (OAUGDP) on inactivation of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes on apples, cantaloupe, and lettuce, respectively. A five-strain mixture of cultured test organisms was washed, suspended in phosphate buffer, and spot inoculated onto produce (7 log CFU per sample). Samples were exposed inside a chamber affixed to the OAUGDP blower unit operated at a power of 9 kV and frequency of 6 kHz. This configuration allows the sample to be placed outside of the plasma generation unit while allowing airflow to carry the antimicrobial active species, including ozone and nitric oxide, onto the food sample. Cantaloupe and lettuce samples were exposed for 1, 3, and 5 min, while apple samples were exposed for 30 s, 1 min, and 2 min. After exposure, samples were pummeled in 0.1% peptone water-2% Tween 80, diluted, and plated in duplicate onto selective media and tryptic soy agar and incubated as follows: E. coli O157:H7 (modified eosin methylene blue) and Salmonella (xylose lysine tergitol-4) for 48 h at 37 degrees C, and L. monocytogenes (modified Oxford medium) at 48 h for 32 degrees C. E. coli O157:H7 populations were reduced by >1 log after 30-s and 1-min exposures and >2 log after a 2-min exposure. Salmonella populations were reduced by >2 log after 1 min. Three- and 5-min exposure times resulted in >3-log reduction. L. monocytogenes populations were reduced by 1 log after 1 min of exposure. Three- and 5-min exposure times resulted in >3- and >5-log reductions, respectively. This process has the capability of serving as a novel, nonthermal processing technology to be used for reducing microbial populations on produce surfaces.

  1. Inactivation of Acanthamoeba spp. and Other Ocular Pathogens by Application of Cold Atmospheric Gas Plasma

    Science.gov (United States)

    Shama, Gilbert; Andrew, Peter W.

    2016-01-01

    Currently there are estimated to be approximately 3.7 million contact lens wearers in the United Kingdom and 39.2 million in North America. Contact lens wear is a major risk factor for developing an infection of the cornea known as keratitis due to poor lens hygiene practices. While there is an international standard for testing disinfection methods against bacteria and fungi (ISO 14729), no such guidelines exist for the protozoan Acanthamoeba, which causes a potentially blinding keratitis most commonly seen in contact lens wearers, and as a result, many commercially available disinfecting solutions show incomplete disinfection after 6 and 24 h of exposure. Challenge test assays based on international standard ISO 14729 were used to determine the antimicrobial activity of cold atmospheric gas plasma (CAP) against Pseudomonas aeruginosa, Candida albicans, and trophozoites and cysts of Acanthamoeba polyphaga and Acanthamoeba castellanii. P. aeruginosa and C. albicans were completely inactivated in 0.5 min and 2 min, respectively, and trophozoites of A. polyphaga and A. castellanii were completely inactivated in 1 min and 2 min, respectively. Furthermore, for the highly resistant cyst stage of both species, complete inactivation was achieved after 4 min of exposure to CAP. This study demonstrates that the CAP technology is highly effective against bacterial, fungal, and protozoan pathogens. The further development of this technology has enormous potential, as this approach is able to deliver the complete inactivation of ocular pathogens in minutes, in contrast to commercial multipurpose disinfecting solutions that require a minimum of 6 h. PMID:26994079

  2. Assessment of awareness on food borne zoonosis and its relation ...

    African Journals Online (AJOL)

    A survey qualitative survey was conducted to assess the awareness on food borne zoonosis and its relation with Veterinary Public Health Services in Addis Ababa and its surrounding districts from November 2008 to May 2009. Structured questionnaire was used in the study. Questionnaires were distributed to 384 ...

  3. Assessment of awareness on food borne zoonosis and its relation ...

    African Journals Online (AJOL)

    A survey qualitative survey was conducted to assess the awareness on food borne zoonosis and its relation with Veterinary ... health institutions don't see the need of having veterinarians in the public health. In conclusion this study demonstrated that the ..... Seroprevalence of Toxoplasma gondii in Nazareth town, Ethiopia.

  4. Applicability of photodynamic antimicrobial chemotherapy as an alternative to inactivate fish pathogenic bacteria in aquaculture systems.

    Science.gov (United States)

    Arrojado, Cátia; Pereira, Carla; Tomé, João P C; Faustino, Maria A F; Neves, Maria G P M S; Tomé, Augusto C; Cavaleiro, José A S; Cunha, Angela; Calado, Ricardo; Gomes, Newton C M; Almeida, Adelaide

    2011-10-01

    Aquaculture activities are increasing worldwide, stimulated by the progressive reduction of natural fish stocks in the oceans. However, these activities also suffer heavy production and financial losses resulting from fish infections caused by microbial pathogens, including multidrug resistant bacteria. Therefore, strategies to control fish infections are urgently needed, in order to make aquaculture industry more sustainable. Antimicrobial photodynamic therapy (aPDT) has emerged as an alternative to treat diseases and prevent the development of antibiotic resistance by pathogenic bacteria. The aim of this work was to evaluate the applicability of aPDT to inactivate pathogenic fish bacteria. To reach this objective a cationic porphyrin Tri-Py(+)-Me-PF was tested against nine pathogenic bacteria isolated from a semi-intensive aquaculture system and against the cultivable bacteria of the aquaculture system. The ecological impact of aPDT in the aquatic environment was also tested on the natural bacterial community, using the overall bacterial community structure and the cultivable bacteria as indicators. Photodynamic inactivation of bacterial isolates and of cultivable bacteria was assessed counting the number of colonies. The impact of aPDT in the overall bacterial community structure of the aquaculture water was evaluated by denaturing gel gradient electrophoresis (DGGE). The results showed that, in the presence of Tri-Py(+)-Me-PF, the growth of bacterial isolates was inhibited, resulting in a decrease of ≈7-8 log after 60-270 min of irradiation. Cultivable bacteria were also considerably affected, showing decreases up to the detection limit (≈2 log decrease on cell survival), but the inactivation rate varied significantly with the sampling period. The DGGE fingerprint analyses revealed changes in the bacterial community structure caused by the combination of aPDT and light. The results indicate that aPDT can be regarded as a new approach to control fish

  5. Evaluation of different inactivation methods for high and low pathogenic avian influenza viruses in egg-fluids for antigen preparation.

    Science.gov (United States)

    Pawar, Shailesh D; Murtadak, Vinay B; Kale, Sandeep D; Shinde, Prashant V; Parkhi, Saurabh S

    2015-09-15

    In view of the emerging avian influenza (AI) viruses, it is important to study the susceptibility of AI viruses to inactivating agents for preparation of antigens and inactivated vaccines. The available information on susceptibility of both the high and low pathogenic AI viruses to different inactivating agents is inadequate and ambiguous. It has been shown that different subtypes of influenza viruses require different physical and chemical conditions for inactivation of infectivity. The present study was undertaken to evaluate the use of beta-propiolactone (BPL), formalin and ether for inactivation and its impact on antigenicity of AI viruses. A total of nine high and low pathogenic AI viruses belonging to four influenza A subtypes were included in the study. The H5N1 viruses were from the clades 2.2, 2.3.2.1 and 2.3.4. The H9N2 virus included in the study was of the G1 genotype, while the H11N1 and H4N6 viruses were from the Eurasian lineage. The viruses were treated with BPL, formalin and with ether. The confirmation of virus inactivation was performed by two serial passages of inactivated viruses in embryonated chicken eggs. The infectivity of all tested AI viruses was eliminated using 0.1% BPL and 0.1% formalin. Ether eliminated infectivity of all tested low pathogenic AI viruses; however, ether with 0.2% or 0.5% Tween-20 was required for inactivation of the highly pathogenic AI H5N1 viruses. Treatment with BPL, ether and formalin retained virus hemagglutination (HA) titers. Interestingly ether treatment resulted in significant rise in HA titers (Pviruses. This data demonstrated the utility of BPL, formalin and ether for the inactivation of infectivity of AI viruses used in the study for the preparation of inactivated virus antigens for research and diagnosis of AI. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Possibility of fighting food borne bacteria by egyptian folk medicinal herbs and spices extracts.

    Science.gov (United States)

    Tayel, Ahmed A; El-Tras, Wael F

    2009-01-01

    Phytotherapy (herbal medicine) have a long-standing history in Egypt. Current study investigated the antimicrobial potentialities of twenty five herbs and spices which are widely used in folk medicine by Egyptian housewives to treat gastrointestinal disorders against seven bacterial strains, mostly food borne including pathogens. They were tested by using paper disc diffusion technique as qualitative assay and agar dilution method for determining the minimum inhibitory concentration (MIC) of herbs extracts. Among screened plants, basil, cardamom, cinnamon, clove, lemon grass, mustard, oregano, rosemary, sage and thyme extracts exhibited notable antimicrobial activities against most of the tested strains. Cinnamon extract was the most inhibitor followed by clove, whereas extracts of chamomile, rose of Jericho, safflower and turmeric showed weak antibacterial activities against most of the tested strains. The most sensitive strain to plant extracts was B. subtilis and the most resistant strain was Ps. fluorescens. herbs and spices extracts -used in Egyptian folk medicine for treating many gastrointestinal disorders - could be successfully applied as natural antimicrobials for elimination of food borne bacteria and pathogens growth.

  7. Toward an International Standard for PCR-Based Detection of Food-Borne Thermotolerant Campylobacters: Assay Development and Analytical Validation

    OpenAIRE

    Lübeck, P. S.; Wolffs, P.; On, S. L. W.; Ahrens, P.; Rådström, P.; Hoorfar, J.

    2003-01-01

    As part of a European research project (FOOD-PCR), we developed a standardized and robust PCR detection assay specific for the three most frequently reported food-borne pathogenic Campylobacter species, C. jejuni, C. coli, and C. lari. Fifteen published and unpublished PCR primers targeting the 16S rRNA gene were tested in all possible pairwise combinations, as well as two published primers targeting the 23S rRNA gene. A panel of 150 strains including target an...

  8. 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.

  9. 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.

  10. Echinostomiasis: a common but forgotten food-borne disease.

    Science.gov (United States)

    Graczyk, T K; Fried, B

    1998-04-01

    Human echinostomiasis, endemic to southeast Asia and the Far East, is a food-borne, intestinal, zoonotic parasitosis attributed to at least 16 species of digenean trematodes transmitted by snails. Two separate life cycles of echinostomes, human and sylvatic, efficiently operate in endemic areas. Clinical symptoms of echinostomiasis include abdominal pain, violent watery diarrhea, and anorexia. The disease occurs focally and transmission is linked to fresh or brackish water habitats. Infections are associated with common sociocultural practices of eating raw or insufficiently cooked mollusks, fish, crustaceans, and amphibians, promiscuous defecation, and the use of night soil (human excrement collected from latrines) for fertilization of fish ponds. The prevalence of infection ranges from 44% in the Philippines to 5% in mainland China, and from 50% in northern Thailand to 9% in Korea. Although the patterns of other food-borne trematodiases have changed in Asia following changes in habits, cultural practices, health education, industrialization, and environmental alteration, human echinostomiasis remains a health problem. The disease is most prevalent in remote rural places among low-wage earners and in women of child bearing age. Echinostomiasis is aggravated by socioeconomic factors such as poverty, malnutrition, an explosively growing free-food market, a lack of supervised food inspection, poor or insufficient sanitation, other helminthiases, and declining economic conditions. Furthermore, World Health Organization control programs implemented for other food-borne helminthiases and sustained in endemic areas are not fully successful for echinostomiasis because these parasites display extremely broad specificity for the second intermediate host and are capable of completing the life cycle without involvement of the human host.

  11. Toward an international standard for PCR-based detection of food-borne thermotolerant Campylobacters: Assay development and analytical validation

    DEFF Research Database (Denmark)

    Lübeck, Peter Stephensen; Wolffs, P.; On, Stephen L.W.

    2003-01-01

    As part of a European research project (FOOD-PCR), we developed a standardized and robust PCR detection assay specific for the three most frequently reported food-borne pathogenic Campylobacter species, C. jejuni, C. coli, and C. lari. Fifteen published and unpublished PCR primers targeting the 16S...... carcass rinse, unlike both Taq DNA polymerase and DyNAzyme. Based on these results, Tth was selected as the most suitable enzyme for the assay. The standardized PCR test described shows potential for use in large-scale screening programs for food-borne Campylobacter species under the assay conditions....... The inclusivity and exclusivity were 100 and 97%, respectively. In an attempt to find a thermostable DNA polymerase more resistant than Taq to PCR inhibitors present in chicken samples, three DNA polymerases were evaluated. The DNA polymerase Tth was not inhibited at a concentration of 2% (vol/vol) chicken...

  12. Inactivation of pathogens during aerobic composting of fresh and aged dairy manure and different carbon amendments.

    Science.gov (United States)

    Erickson, Marilyn C; Liao, Jean; Jiang, Xiuping; Doyle, Michael P

    2014-11-01

    Two separate studies were conducted to address the condition and the type of feedstocks used during composting of dairy manure. In each study, physical (temperature), chemical (ammonia, volatile acids, and pH), and biological (Salmonella, Listeria monocytogenes, and Escherichia coli O157:H7) parameters were monitored during composting in bioreactors to assess the degree to which they were affected by the experimental variables and, ultimately, the ability of the chemical and physical parameters to predict the fate of pathogens during composting. Compost mixtures that contained either aged dairy manure or pine needles had reduced heat generation; therefore, pathogen reduction took longer than if fresh manure or carbon amendments of wheat straw or peanut hulls were used. Based on regression models derived from these results, ammonia concentration, in addition to heat, were the primary factors affecting the degree of pathogen inactivation in compost mixtures formulated to an initial carbon-nitrogen (C:N) ratio of 40:1, whereas, the pH of the compost mixture along with the amount of heat exposure were most influential in compost mixtures formulated to an initial C:N ratio of 30:1. Further studies are needed to validate these models so that additional criteria in addition to time and temperature can be used to evaluate the microbiological safety of composted manures.

  13. Antimicrobial blue light inactivation of pathogenic microbes: State of the art.

    Science.gov (United States)

    Wang, Yucheng; Wang, Ying; Wang, Yuguang; Murray, Clinton K; Hamblin, Michael R; Hooper, David C; Dai, Tianhong

    2017-11-01

    As an innovative non-antibiotic approach, antimicrobial blue light in the spectrum of 400-470nm has demonstrated its intrinsic antimicrobial properties resulting from the presence of endogenous photosensitizing chromophores in pathogenic microbes and, subsequently, its promise as a counteracter of antibiotic resistance. Since we published our last review of antimicrobial blue light in 2012, there have been a substantial number of new studies reported in this area. Here we provide an updated overview of the findings from the new studies over the past 5 years, including the efficacy of antimicrobial blue light inactivation of different microbes, its mechanism of action, synergism of antimicrobial blue light with other angents, its effect on host cells and tissues, the potential development of resistance to antimicrobial blue light by microbes, and a novel interstitial delivery approach of antimicrobial blue light. The potential new applications of antimicrobial blue light are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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.

  19. From ontology selection and semantic web to an integrated information system for food-borne diseases and food safety.

    Science.gov (United States)

    Yan, Xianghe; Peng, Yun; Meng, Jianghong; Ruzante, Juliana; Fratamico, Pina M; Huang, Lihan; Juneja, Vijay; Needleman, David S

    2011-01-01

    Several factors have hindered effective use of information and resources related to food safety due to inconsistency among semantically heterogeneous data resources, lack of knowledge on profiling of food-borne pathogens, and knowledge gaps among research communities, government risk assessors/managers, and end-users of the information. This paper discusses technical aspects in the establishment of a comprehensive food safety information system consisting of the following steps: (a) computational collection and compiling publicly available information, including published pathogen genomic, proteomic, and metabolomic data; (b) development of ontology libraries on food-borne pathogens and design automatic algorithms with formal inference and fuzzy and probabilistic reasoning to address the consistency and accuracy of distributed information resources (e.g., PulseNet, FoodNet, OutbreakNet, PubMed, NCBI, EMBL, and other online genetic databases and information); (c) integration of collected pathogen profiling data, Foodrisk.org ( http://www.foodrisk.org ), PMP, Combase, and other relevant information into a user-friendly, searchable, "homogeneous" information system available to scientists in academia, the food industry, and government agencies; and (d) development of a computational model in semantic web for greater adaptability and robustness.

  20. 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.

  1. Towards an international standard for PCR-based detection of food-borne thermotolerant Campylobacters: assay development and analytical validation.

    OpenAIRE

    Lübeck, P S; Wolffs, Petra; On, S L; Ahrens, P; Rådström, Peter; Hoorfar, J

    2003-01-01

    As part of a European research project (FOOD-PCR), we developed a standardized and robust PCR detection assay specific for the three most frequently reported food-borne pathogenic Campylobacter species, C. jejuni, C. coli, and C. lari. Fifteen published and unpublished PCR primers targeting the 16S rRNA gene were tested in all possible pairwise combinations, as well as two published primers targeting the 23S rRNA gene. A panel of 150 strains including target and nontarget strains was used in ...

  2. 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.

  3. The use of visible light and metal oxide nano particles for pathogen inactivation

    Science.gov (United States)

    Lubart, R.; Lipovski, A.; Gedanken, A.

    2012-09-01

    Since the effectiveness of antibiotic treatment is decreasing due to the development of resistant strains, alternative approaches for destroying microorganisms are needed. In this review we summarize new technologies that might be effective for pathogen inactivation. In the past we found that intense blue light could be used for bacterial eradication. The phototoxic effect correlated with the amount of reactive oxygen species (ROS) generated by the bacteria due to illumination. Recently it has been shown that the effect of light can be enhanced by introducing metal oxide nanoparticles (nps) to the bacteria prior to irradiation. This led us to suggest combining nanoparticles with visible light irradiation for pathogen eradication. We have shown that combination of illumination with the nanoparticles (ZnO or TiO2) resulted in a marked increase in the reduction of bacterial viability to a mean reduction of 80-90% for both nanoaprticles. As a matter of fact metal oxide nps alone can be used for bacteria destruction. The advantage of our approach is the use of lower concentrations of nps, combined with reduced light intensity that is less toxic to the host tissue. To further avoid the toxicity of metal oxides nps on healthy tissue it is possible to coat their surfaces with various substrates including ceramics and polymers. Recently Zinc oxide nanoparticles have been synthesized and deposited on the surface of cotton fabrics using ultrasound irradiation. Thus in the future we will try to treat infected wounds with transparent bandages coated with ZnO that will be applied to the wounds prior to irradiation.

  4. Food-borne tonsillopharyngitis outbreak in a hospital cafeteria.

    Science.gov (United States)

    Ertugrul, B M; Erol, N; Emek, M; Ozturk, B; Saylak, O M; Cetin, K; Sakarya, S

    2012-02-01

    A food-borne tonsillopharyngitis outbreak was reported between 9th and 13th of February, 2008, in Söke State Hospital, Aydın, Turkey. This descriptive cohort study was carried out immediately after the outbreak. In order to determine the probable origin, a questionnaire involving demographical features, clinical features, and possible risk factors was distributed to 403 persons. The participants of the questionnaire (n = 403) were divided into two groups: the study group (n = 252); those with any two of the following three complaints; sore throat, fever, and dizziness, and the control group (n = 151); those without these complaints. This investigation revealed that 252 people were affected by this outbreak. Group A β-hemolytic streptococci were isolated from the throat cultures of 63 affected individuals (25%) and an employee working in the patisserie that made desserts served for lunch. Since the number of people who ate the milky dessert was statistically higher compared to the non-eaters, the milky dessert was thought to be the origin of the outbreak. We suggest that throat infections among employees working in food production may cause outbreaks of upper respiratory tract infections.

  5. Source attribution of food-borne zoonoses in New Zealand: a modified Hald model.

    Science.gov (United States)

    Mullner, Petra; Jones, Geoff; Noble, Alasdair; Spencer, Simon E F; Hathaway, Steve; French, Nigel Peter

    2009-07-01

    A Bayesian approach was developed by Hald et al.((1)) to estimate the contribution of different food sources to the burden of human salmonellosis in Denmark. This article describes the development of several modifications that can be used to adapt the model to different countries and pathogens. Our modified Hald model has several advantages over the original approach, which include the introduction of uncertainty in the estimates of source prevalence and an improved strategy for identifiability. We have applied our modified model to the two major food-borne zoonoses in New Zealand, namely, campylobacteriosis and salmonellosis. Major challenges were the data quality for salmonellosis and the inclusion of environmental sources of campylobacteriosis. We conclude that by modifying the Hald model we have improved its identifiability, made it more applicable to countries with less intensive surveillance, and feasible for other pathogens, in particular with respect to the inclusion of nonfood sources. The wider application and better understanding of this approach is of particular importance due to the value of the model for decision making and risk management.

  6. 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

  7. Bacteriophages with potential for inactivation of fish pathogenic bacteria: survival, host specificity and effect on bacterial community structure.

    Science.gov (United States)

    Pereira, Carla; Silva, Yolanda J; Santos, Ana L; Cunha, Angela; Gomes, Newton C M; Almeida, Adelaide

    2011-01-01

    Phage therapy may represent a viable alternative to antibiotics to inactivate fish pathogenic bacteria. Its use, however, requires the awareness of novel kinetics phenomena not applied to conventional drug treatments. The main objective of this work was to isolate bacteriophages with potential to inactivate fish pathogenic bacteria, without major effects on the structure of natural bacterial communities of aquaculture waters. The survival was determined in marine water, through quantification by the soft agar overlay technique. The host specificity was evaluated by cross infection. The ecological impact of phage addition on the structure of the bacterial community was evaluated by DGGE of PCR amplified 16S rRNA gene fragments. The survival period varied between 12 and 91 days, with a higher viability for Aeromonas salmonicida phages. The phages of Vibrio parahaemolyticus and of A. salmonicida infected bacteria of different families with a high efficacy of plating. The specific phages of pathogenic bacteria had no detectable impact on the structure of the bacterial community. In conclusion, V. parahaemolyticus and A. salmonicida phages show good survival time in marine water, have only a moderated impact on the overall bacterial community structure and the desired specificity for host pathogenic bacteria, being potential candidates for therapy of fish infectious diseases in marine aquaculture systems.

  8. Bacteriophages with Potential for Inactivation of Fish Pathogenic Bacteria: Survival, Host Specificity and Effect on Bacterial Community Structure

    Directory of Open Access Journals (Sweden)

    Yolanda J. Silva

    2011-11-01

    Full Text Available Phage therapy may represent a viable alternative to antibiotics to inactivate fish pathogenic bacteria. Its use, however, requires the awareness of novel kinetics phenomena not applied to conventional drug treatments. The main objective of this work was to isolate bacteriophages with potential to inactivate fish pathogenic bacteria, without major effects on the structure of natural bacterial communities of aquaculture waters. The survival was determined in marine water, through quantification by the soft agar overlay technique. The host specificity was evaluated by cross infection. The ecological impact of phage addition on the structure of the bacterial community was evaluated by DGGE of PCR amplified 16S rRNA gene fragments. The survival period varied between 12 and 91 days, with a higher viability for Aeromonas salmonicida phages. The phages of Vibrio parahaemolyticus and of A. salmonicida infected bacteria of different families with a high efficacy of plating. The specific phages of pathogenic bacteria had no detectable impact on the structure of the bacterial community. In conclusion, V. parahaemolyticus and A. salmonicida phages show good survival time in marine water, have only a moderated impact on the overall bacterial community structure and the desired specificity for host pathogenic bacteria, being potential candidates for therapy of fish infectious diseases in marine aquaculture systems.

  9. Chemical Composition and Antimicrobial Activities of Essential Oils from Nepeta cataria L. against Common Causes of Food-Borne Infections.

    Science.gov (United States)

    Zomorodian, Kamiar; Saharkhiz, Mohammad Jamal; Shariati, Samaneh; Pakshir, Keyvan; Rahimi, Mohammad Javad; Khashei, Reza

    2012-01-01

    Nepeta cataria L. is traditionally consumed as a food additive. The effects of three different harvest stages of N. cataria essential oils (EOs) against most common causes of food-borne infections were evaluated by broth microdilution method as recommended by the Clinical and Laboratory Standards Institute (CLSI). The chemical composition of the EOs from N. cataria has been analyzed by gas chromatography/mass spectrometry (GC/MS). The analysis of the EOs indicated that 4a-α,7-α,7a-β-nepetalactone (55-58%) and 4a-α,7-β,7a-α-nepetalactone (30-31.2%) were the major compounds of the EOs at all developmental stages. The results showed that the tested EOs exhibited antimicrobial activities against the food-borne pathogens at concentrations of 0.125-2 μL/mL. Based on these results, the EO of N. cataria can possibly be used in food products as a natural preservative agent.

  10. 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.

  11. 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

  12. PREVALENCE AND ANTIBIOTIC RESISTANCE OF FOOD BORNE BACTERIAL CONTAMINATION IN SOME EGYPTIAN FOOD food

    Directory of Open Access Journals (Sweden)

    Samy Selim

    2015-09-01

    Full Text Available This study was undertaken to investigate the prevalence and antibiotic resistance of food borne bacterial contamination in some Egyptian food. Total viable bacteria and total coliform bacteriawere isolated from different sources of food; carbohydrates (bread, flour and basbousa, vegetables (outer and inner tissues of potato and outer and inner tissues of cucumber and proteins (mincedmeat, cheese and milk. The study resulted in maximum value of total viable bacteria found in outer tissue of potato 68X104±1.0, while the minimum value found in inner tissues of potato andcucumber. The study resulted in total coliform was maximum value in minced meat 6.4X103±0.3. Basbousa and inner tissue of potato and cucumber were free from coliforms. The ability of isolatesto producing proteolytic enzymes was tested, we found that 326 isolate (63.92% from all isolates had this ability, thus we selected most 2 potent proteolytic isolates. The two isolates were identifiedas Bacillus cereus and Escherichia coli. The identification confirmed by microlog 34.20 system and 16SrRNA for two isolates and the same result was founded. Sensitivity tested for the most potentproteolytic species to 12 of the most commonly used antibiotics in the Egyptian pharmacy. The results showed that all species were sensitive to most of antibiotics, except B. cereus which was strongly susceptible to azteronam and ceftazidim. The data showed that raw meat, cooked food products, and raw milk were most commonly contaminated with foodborne pathogens and many pathogens were resistant to different antibiotics. The study provided useful information for assessment of the possible risk posed to consumers, which has significant public health impact.

  13. 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

  14. 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

  15. 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

  16. 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.

  17. Assessment of survival of food-borne microorganisms in the food chain by fluorescence ratio imaging microscopy

    DEFF Research Database (Denmark)

    Siegumfeldt, Henrik; Arneborg, Nils

    2011-01-01

    Traditionally, many data on food–borne microorganisms are obtained as an average of a whole population, under the assumption that the individual cells are clonal and therefore identical. However, it is now acknowledged that there may be a large heterogeneity within an isogenic population, and con......Traditionally, many data on food–borne microorganisms are obtained as an average of a whole population, under the assumption that the individual cells are clonal and therefore identical. However, it is now acknowledged that there may be a large heterogeneity within an isogenic population......, and consequently new methods focus on the individual cells. This mini-review will give an overview of the response of food-borne microorganisms; i.e. pathogenic bacteria, lactic acid bacteria, and yeasts, at a single-cell level to various food-related stress conditions, comprising acid-, disinfection-, salt...

  18. Transfer of foodborne pathogens during mechanical slicing and their inactivation by levulinic acid-based sanitizer on slicers.

    Science.gov (United States)

    Chen, Dong; Zhao, Tong; Doyle, Michael P

    2014-04-01

    This study investigated the degree of cross-contamination between deli foods and slicers by Listeria monocytogenes, Salmonella, and Escherichia coli O157:H7, and their inactivation by levulinic acid (LA) plus sodium dodecyl sulfate (SDS) on slicers. The transfer rate of pathogens at 5 locations on the contaminated slicers (scenario I) and on food slices (scenario II) was determined. The antimicrobial efficacy of the LA + SDS sanitizers applied either as a liquid or as foam at three concentrations (0.5% LA + 0.05% SDS, 1% LA + 0.1% SDS, and 2% LA + 0.5% SDS) was determined for decontamination of the pathogens on the slicers at 21 °C. After slicing 10 slices, the pathogens recovered from slicer blades were significantly (P  0.9, scenario II). Contaminated slicer surfaces sprayed with 1% LA plus 0.1% SDS as a foam (45-55 psi) reduced within 1 min 6.0 to 8.0 log CFU/blade of the pathogens. Results revealed that cross-contamination can occur between deli foods and slicers. Also, LA-based sanitizer applied as foam can be a useful treatment to remove microbial contamination on the slicers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. 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.

  20. 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.

  1. 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...

  2. 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 ...

  3. Food-borne botulism in Japan in March 2012.

    Science.gov (United States)

    Momose, Yoshika; Asakura, Hiroshi; Kitamura, Masaru; Okada, Yumiko; Ueda, Yutaka; Hanabara, Yutaro; Sakamoto, Tomohiro; Matsumura, Tsuyoshi; Iwaki, Masaaki; Kato, Haru; Shibayama, Keigo; Igimi, Shizunobu

    2014-07-01

    In March 2012, two patients were transported urgently to the hospital in Tottori Prefecture, Japan, because of symptoms suggestive of botulism. Botulinum neurotoxin type A was detected in the clinical specimens and the food consumed by the two patients (vacuum packed adzuki-batto, a sweet adzuki bean soup containing noodles). We were able to make a prompt diagnosis of food botulism associated with the consumption of adzuki-batto, from which the causative pathogen Clostridium botulinum Ab was cultured. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    Zhu, Feng; Zhou, Yang-Kai; Ji, Zhao-Lin; Chen, Xiao-Ren

    2018-01-01

    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 be beneficial to

  6. Effect of sanitizer combined with steam heating on the inactivation of foodborne pathogens in a biofilm on stainless steel.

    Science.gov (United States)

    Ban, Ga-Hee; Kang, Dong-Hyun

    2016-05-01

    The combined effect of chemical sanitizers including sodium hypochlorite, hydrogen peroxide, iodophor, and benzalkonium chloride with steam heating on the inactivation of biofilms formed by Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on stainless steel was investigated. Six day old biofilms, comprised of a mixture of three strains each of three foodborne pathogens, were produced on stainless steel coupons at 25 °C and treated with each sanitizer alone (for 5, 15, and 30 s), steam alone (for 5, 10, and 20 s), and the combination. There was a synergistic effect of sanitizer and steam on the viability of biofilm cells of the three pathogens as evidenced by plating counts and imaging. The combination treatment achieved an additional 0.01 to 2.78 log reduction compared to the sum of each individual treatment. The most effective combination for reducing levels of biofilm cells was the combination of steam and iodophor; steam for 20 s and merely 20 ppm iodophor for 30 s reduced cell numbers to below the detection limit (sanitizer with steam can be applied to control foodborne pathogens biofilm cells in food processing facilities as a potential intervention. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Physical Inactivation of Monodon Baculovirus (Mbv, a Pathogenic Virus of Tiger Prawn (Penaeus Monodon Fab.

    Directory of Open Access Journals (Sweden)

    M. Alifuddin

    2007-05-01

    Full Text Available ABSTRACTA study of physical inactivation of MBV was carried out by conducting monitoring observation of reared shrimp test under laboratory condition.  Experimental shrimp were reared at PSIK (Pusat Studi Ilmu Kelautan, Jakarta and examined histologically for MBV infection at Lab. of Fish Health, Department of Aquaculture Faculty of Fisherise IPB.  This study was conducted by transmission trial and physical inactivation of virus MBV.  Preparation of inoculum followed Momoyama and Sano (1988; shrimp test were infected by water borne infection.  Presence of infection indicated by histological observation of hipertropied hepatopancreas cell containing inclusion bodies of virus.  Inactivation of MBV was done by heating at 40, 45, 50 and 55 'C for 30 minute and uv radiation for 5, 10, 15 and 20 minute with the distance 30 cm from the uv lamp 15 watt as radiation sources.  Transmission trial showed that infection occured 6 hours post inoculation and inclusion bodies were detected at day 5th; showed the virus lost their infectivities or virulent since no inclusion t Ddies as indicator for MBV infection were detected on hepatopancreas of shrimp test. Key words :  Tiger prawn (Penaeus monodon Fab., viral diseases, physical inactivation.ABSTRAKSuatu penelitian mengenai inaktifasi fisik terhadap Monodon baculovirus (MBV, suatu virus patogen yang menyerang udang windu (Penaeus monodon Fab., telah dilaksanankan sejak bulan Juli 1994 sampai bulan Maret 1995.  Penelitian ini dilakukan di Laboratorium Kesehatan Ikan, Jurusan Budidaya Perairan, Fakultas Perikanan IPB dan Pusat Studi limu Kelautan (PSIK Institut Pertanian Bogor, Jakarta.  Percobaan yang dilakukan meliputi percobaan penularan virus dan percobaan inaktifasi fisik virus.  Inaktifasi fisik terhadap virus MBV dilakukan dengan pemanasan pada 4 tingkat suhu yang berbeda (40, 45, 50 dan 55 'C selama 30 menit dan radiasi ultraviolet pada 4 tingkat waktu penyinaran (5, 10, 15 dan 20 menit dengan

  8. Identifying the source of food-borne disease outbreaks: An application of Bayesian variable selection.

    NARCIS (Netherlands)

    Jacobs, Rianne; Lesaffre, Emmanuel; Teunis, Peter Fm; Höhle, Michael; van de Kassteele, Jan

    2017-01-01

    Early identification of contaminated food products is crucial in reducing health burdens of food-borne disease outbreaks. Analytic case-control studies are primarily used in this identification stage by comparing exposures in cases and controls using logistic regression. Standard epidemiological

  9. Allspice, cinnamon, and clove bud plant essential oils in edible apple films inactivate the foodborne pathogens Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes

    Science.gov (United States)

    Plant essential oils (EOs) are rich sources of volatile terpenoids and phenolic compounds. Such compounds have the potential to inactivate pathogenic bacteria in the vapor phase. Edible films made from fruits or vegetables containing EOs can be used commercially to protect food against contaminati...

  10. Allspice, cinnamon and clove bud plant essential oils in edible apple films inactivate the foodbrone pathogens Escherichia coli Ol57:h7, Salmonella enterica and Listeria monocytogenes

    Science.gov (United States)

    Plant essential oils (EOs) are rich sources of volatile terpenoids and phenolic compounds. Such compounds have the potential to inactivate pathogenic bacteria in the vapor phase. Edible films made from fruits or vegetables containing EOs can be used commercially to protect food against contamination...

  11. Reduction of high pathogenicity avian influenza virus in eggs from chickens once or twice vaccinated with an oil-emulsified inactivated H5 avian influenza vaccine

    Science.gov (United States)

    The negative impact of high pathogenicity avian influenza virus (HPAIV) infection on egg production and deposition of virus in eggs, as well as any protective effect of vaccination, is unknown. Individually housed non-vaccinated, sham-vaccinated and inactivated H5N9 vaccinated once or twice adult Wh...

  12. In vitro inactivation of endodontic pathogens with Nd:YAG and Er:YAG lasers.

    Science.gov (United States)

    Meire, Maarten A; Coenye, Tom; Nelis, Hans J; De Moor, Roeland J G

    2012-07-01

    Both Nd:YAG and Er:YAG lasers have been suggested as root canal disinfection aids. The aim of this in vitro study is to compare both wavelengths in terms of irradiation dose required for microbial inactivation, to quantify these irradiation doses and to investigate the influence of certain (laser) parameters on the antimicrobial efficacy. Agar plates containing a uniform layer of Enterococcus faecalis, Candida albicans or Propionibacterium acnes were mounted perpendicularly underneath the laser handpieces (5 mm spot). The Er:YAG laser was operated in single-pulse mode. Pulse energies of 40-400 mJ and pulse lengths of 100, 300, 600, and 1,000 μs were tested. After incubation at 37°C for 48 h, growth on the plates was scored. The pulse energy yielding complete absence of growth over the entire spot area was taken as the total inhibition threshold (TIT). TITs were determined for every species and pulse length. The Nd:YAG laser was operated with pulse trains because single pulses were ineffective. Output power was 15 W and frequency was 100 Hz. Spots were irradiated for 5-120 s. After incubation, the diameters of the inhibition zones were measured. For the Er:YAG laser, TITs varied between 100 and 210 mJ, and differed significantly between species and pulse lengths. Using Nd:YAG irradiation, TITs were around 5,300 J/cm(2) for C. albicans and 7,100 J/cm(2) for P. acnes. No inhibition was observed for E. faecalis. Er:YAG irradiation was superior to Nd:YAG in inactivating microorganisms on agar surfaces.

  13. 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

    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...

  14. 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.

  15. Inactivation of selected bacterial pathogens in dairy cattle manure by mesophilic anaerobic digestion (balloon type digester).

    Science.gov (United States)

    Manyi-Loh, Christy E; Mamphweli, Sampson N; Meyer, Edson L; Okoh, Anthony I; Makaka, Golden; Simon, Michael

    2014-07-14

    Anaerobic digestion of animal manure in biogas digesters has shown promise as a technology in reducing the microbial load to safe and recommended levels. We sought to treat dairy manure obtained from the Fort Hare Dairy Farm by investigating the survival rates of bacterial pathogens, through a total viable plate count method, before, during and after mesophilic anaerobic digestion. Different microbiological media were inoculated with different serial dilutions of manure samples that were withdrawn from the biogas digester at 3, 7 and 14 day intervals to determine the viable cells. Data obtained indicated that the pathogens of public health importance were 90%-99% reduced in the order: Campylobacter sp. (18 days) anaerobic digestion process. In addition, the highest p-value i.e., 0.957 for E. coli showed the statistical significance of its model and the strongest correlation between its reductions with days of digestion. In conclusion, the results demonstrated that the specific bacterial pathogens in manure can be considerably reduced through anaerobic digestion after 133 days.

  16. Effectiveness of low concentration electrolyzed water to inactivate foodborne pathogens under different environmental conditions.

    Science.gov (United States)

    Rahman, S M E; Ding, Tian; Oh, Deog-Hwan

    2010-05-15

    Strong acid electrolyzed water (SAEW) has a very limited application due to its low pH value (4.0, 5.0, 6.0 and 9.0) and temperatures (4, 15, 23, 35 and 50 degrees C) were determined. Reductions of bacterial populations of 1.7 to 6.6 log(10) CFU/mL in various treated conditions in cell suspensions were observed after treatment with LcEW and SAEW, compared to the untreated control. Dip washing (1 min at 35 degrees C) of lettuce leaves in both electrolyzed water resulted in 2.5 to 4.0 log(10) CFU/g compared to the unwashed control. Strong inactivation effects were observed in LcEW, and no significant difference (p>0.05) was observed between LcEW and SAEW. The effective form of chlorine compounds in LcEW was almost exclusively hypochlorous acid (HOCl), which has strong antimicrobial activity and leaves no residuals due to the low concentration of residual chlorine. Thus, LcEW could be widely applied as a new sanitizer in the food industry. 2010 Elsevier B.V. All rights reserved.

  17. 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.

  18. 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.

  19. 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.

  20. Overview of the ability of different treatment methods for liquid and solid manure to inactivate pathogens.

    Science.gov (United States)

    Martens, W; Böhm, R

    2009-11-01

    The use of manure as a fertilizer in agriculture includes the risk of spreading pathogenic infectious agents to the environment, to animals and humans. The treatment of manure can help avoid or reduce these risks. Even if the treatment is dominated by economic considerations such as biogas production, ammonia stripping or phosphorous precipitation, the hygienic aspect should be kept in mind. Otherwise, new infection chains may be established by the use of insufficiently treated manure by-products such as fertilizers still containing infective pathogens. Treatment plants should use a concept according to HACCP principles that includes hazard analysis, risk assessment, the determination of process relevant CCPs and the validation of the process by determining the hygienizing efficiency using representative test organisms as well as microbial end product supervision. Treatment methods can be divided into physical, chemical and microbiological treatment, sometimes used in combination. For economical reasons, only composting or anaerobic treatment (biogas) or, to a minor extent, aerobic thermophilic stabilization (ATS) are used as routine preventive measures on a farm level. In cases of outbreaks of notifiable diseases both physical and chemical treatment of manure can lead to reliable disinfected/pasteurised end products which can be used in agriculture without long-lasting risks for soil fertility or the environment.

  1. Home-style beef jerky: effect of four preparation methods on consumer acceptability and pathogen inactivation.

    Science.gov (United States)

    Harrison, J A; Harrison, M A; Rose-Morrow, R A; Shewfelt, R L

    2001-08-01

    The safety of homemade jerky continues to be questioned. Producing a safe product that retains acceptable quality attributes is important. Lethality of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes as well as consumer acceptability and sensory attributes of jerky prepared by four methods were examined. Preparation methods were drying marinated strips at 60 degrees C (representing a traditional method), boiling strips in marinade or heating in an oven to 71 degrees C prior to drying, and heating strips in an oven after drying to 71 degrees C. A 60-member consumer panel rated overall acceptability. A 10-member descriptive panel evaluated quality attributes. Samples heated after drying and samples boiled in marinade prior to drying had slightly higher acceptability scores but were not statistically different from traditional samples. Although the four treatments were significantly different in color (P = 0.0001), saltiness (P = 0.0001), and texture (P = 0.0324), only texture appeared to influence overall consumer acceptability. Microbial challenge studies subjecting the pathogens to the four treatments showed a 5.8-, 3.9-, and 4.6-log reduction of E. coli O157:H7, L. monocytogenes, and Salmonella, respectively, even with traditional drying. Oven treatment of strips after drying was shown to have the potential to reduce pathogen populations further by approximately 2 logs. In conclusion, a safer, yet acceptable home-dried beef jerky product can be produced by oven-heating jerky strips after drying.

  2. Chemical Composition and Antibacterial Effect of Medicinal Plants against Some Food-Borne Pathogen

    Directory of Open Access Journals (Sweden)

    Hassan Habibi

    2017-05-01

    Conclusion: Antibacterial efficacy shown by these plants provides a scientific basis and thus validates their use as medicinal remedies. Isolation and purification of different phytochemicals may further yield significant antibacterial agents.

  3. Food-borne human parasitic pathogens associated with household cockroaches and houseflies in Nigeria

    OpenAIRE

    Oyeyemi, Oyetunde T.; Agbaje, Mariam O.; Okelue, Uchechi B.

    2016-01-01

    Cockroaches and houseflies pose significant public health threat owning to their ability to mechanically transmit human intestinal parasites and other disease-causing microorganisms. This study aims at assessing the vectoral capacity of cockroaches and houseflies in the transmission of human intestinal parasites. Intestinal parasite external surface contamination of 130 cockroaches and 150 houseflies caught within dwelling places in Ilishan-Remo town, Ogun State, Nigeria was determined. Cockr...

  4. Food-borne human parasitic pathogens associated with household cockroaches and houseflies in Nigeria

    Directory of Open Access Journals (Sweden)

    Oyetunde T. Oyeyemi

    2016-03-01

    Full Text Available Cockroaches and houseflies pose significant public health threat owning to their ability to mechanically transmit human intestinal parasites and other disease-causing microorganisms. This study aims at assessing the vectoral capacity of cockroaches and houseflies in the transmission of human intestinal parasites. Intestinal parasite external surface contamination of 130 cockroaches and 150 houseflies caught within dwelling places in Ilishan-Remo town, Ogun State, Nigeria was determined. Cockroaches (six parasite species were more contaminated than houseflies (four parasite species. The most prevalent parasites were Trichuris trichiura (74.0% and hookworm (63.0% in houseflies and cockroaches respectively. There were significant differences in the prevalence of hookworm, T. trichiura and Taenia spp. isolated from cockroaches and houseflies (P < 0.05. There is high contamination of human intestinal parasites in cockroaches and houseflies in human dwelling places in the study area, thus they have the ability to transmit these parasites to unkempt food materials.

  5. Effect of alcoholic extract of garlic (Allium sativum on some food born pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    M. Ghiami Rad

    2017-02-01

    Full Text Available According to consumers' desire to consume foods without preservatives or containing a natural preservative, the use of plant extracts as a food preservative instead of chemicals has increased. This study was conducted to determine the antibacterial effect of different concentration of alcoholic extract of garlic (Allium sativum on standard strains of Salmonella enteritidis, Bacillus subtilis, Listeria monocytogenes and Yersinia entrocolitica. For this purpose, the agar well diffusion method was used. Minimum Inhibitory Concentration (MIC and Minimum Bactericidal Concentration (MBC were measured with microtiter plate method using the rezazurin reagent. The results showed that garlic alcoholic extract had an inhibitory effect on any four tested bacteria. The highest inhibitory effect was observed on B. subtilis;meanwhile,the slightest effect was found on S. enteritidis. The minimum inhibitory concentration of 0.39 mg/ml was observed for B. subtilis, however the highest amount was estimated at 12.5 mg/ml for S. enteritidis. According to the results of recent research it was concluded that alcoholic extract of garlic had appropriate antibacterial impact against bacteria and therefore could be used as a natural preservative in various foods.

  6. Co-infection dynamics of a major food-borne zoonotic pathogen in chicken

    DEFF Research Database (Denmark)

    Skanseng, Beate; Trosvik, Pal; Zimonja, Monika

    2007-01-01

    , with an important reservoir in the gastrointestinal (GI) tract of chickens, was used as a model. We investigated the co-colonisation dynamics of seven C. jejuni strains in a chicken GI infection trial. The seven strains were isolated from an epidemiological study showing multiple strain infections at the farm level....... We analysed time-series data, following the Campylobacter colonisation, as well as the dominant background flora of chickens. Data were collected from the infection at day 16 until the last sampling point at day 36. Chickens with two different background floras were studied, mature ( treated...... with Broilact, which is a product consisting of bacteria from the intestinal flora of healthy hens) and spontaneous. The two treatments resulted in completely different background floras, yet similar Campylobacter colonisation patterns were detected in both groups. This suggests that it is the chicken host...

  7. Real-time PCR Detection of Food-borne Pathogenic Salmonella spp

    DEFF Research Database (Denmark)

    Malorny, B.; Mäde, D.; Löfström, Charlotta

    2013-01-01

    Infections by Salmonella enterica are a significant public health concern worldwide. Salmonellae form a complex group of bacteria consisting of two species, six subspecies and more than 2500 serovars (serotypes). Mainly through ingestion of contaminated food or feed, they cause self-limiting gast...... for the detection of Salmonella and give a state-of-the-art summary what targets are used and how valid the assays are to apply as diagnostic tool. Furthermore, recommendations for selection of an appropriate real-time PCR method are presented......., effective sample preparation prior to the analytical real-time PCR assay avoids inhibitory substances disturbing the PCR and contributes to a high sensitivity. We discuss appropriate sample preparation methods including enrichment procedures for various food items and analytical real-time PCR assays...

  8. Real-time PCR Detection of Food-borne Pathogenic Salmonella spp

    DEFF Research Database (Denmark)

    Malorny, B.; Mäde, D.; Löfström, Charlotta

    2013-01-01

    -limiting gastrointestinal disease in a wide range of mammalian hosts. Within the last decade, numerous real-time PCR assays have been developed for rapid detection of salmonellae in potentially contaminated food or feed. Some of them were extensively validated and are useful for diagnostic laboratories. Furthermore......, effective sample preparation prior to the analytical real-time PCR assay avoids inhibitory substances disturbing the PCR and contributes to a high sensitivity. We discuss appropriate sample preparation methods including enrichment procedures for various food items and analytical real-time PCR assays...... for the detection of Salmonella and give a state-of-the-art summary what targets are used and how valid the assays are to apply as diagnostic tool. Furthermore, recommendations for selection of an appropriate real-time PCR method are presented....

  9. Structural and functional properties of a truncated hemoglobin from a food-borne pathogen Campylobacter jejuni.

    Science.gov (United States)

    Lu, Changyuan; Egawa, Tsuyoshi; Wainwright, Laura M; Poole, Robert K; Yeh, Syun-Ru

    2007-05-04

    Campylobacter jejuni contains two hemoglobins, Cgb and Ctb. Cgb has been suggested to perform an NO detoxification reaction to protect the bacterium against NO attack. On the other hand, the physiological function of Ctb, a class III truncated hemoglobin, remains unclear. By using CO as a structural probe, resonance Raman data show that the distal heme pocket of Ctb exhibits a positive electrostatic potential. In addition, two ligand-related vibrational modes, nu(Fe-O(2)) and nu(O-O), were identified in the oxy derivative, with frequencies at 542 and 1132 cm(-1), respectively, suggesting the presence of an intertwined H-bonding network surrounding the heme-bound ligand, which accounts for its unusually high oxygen affinity (222 microm(-1)). Mutagenesis studies of various distal mutants suggest that the heme-bound dioxygen is stabilized by H-bonds donated from the Tyr(B10) and Trp(G8) residues, which are highly conserved in the class III truncated hemoglobins; furthermore, an additional H-bond donated from the His(E7) to the Tyr(B10) further regulates these H-bonding interactions by restricting the conformational freedom of the phenolic side chain of the Tyr(B10). Taken together, the data suggest that it is the intricate balance of the H-bonding interactions that determines the unique ligand binding properties of Ctb. The extremely high oxygen affinity of Ctb makes it unlikely to function as an oxygen transporter; on the other hand, the distal heme environment of Ctb is surprisingly similar to that of cytochrome c peroxidase, suggesting a role of Ctb in performing a peroxidase or P450-type of oxygen chemistry.

  10. Adaptation of the food-borne pathogen Bacillus cereus to carvacrol

    NARCIS (Netherlands)

    Ultee, A.; Kets, E.P.W.; Alberda, M.; Hoekstra, F.A.; Smid, E.J.

    2000-01-01

    Carvacrol, a natural antimicrobial compound present in the essential oil fraction of oregano and thyme, is bactericidal towards Bacillus cereus. A decrease of the sensitivity of B. cereus towards carvacrol was observed after growth in the presence of non-lethal carvacrol concentrations. A decrease

  11. 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

  12. Studies on inactivation of pathogenic microorganisms in culture media and in bovine semen by photosensitive agents.

    Science.gov (United States)

    Eaglesome, M D; Bielanski, A; Hare, W C; Ruhnke, H L

    1994-01-01

    The application of three photosensitive agents for disinfection of bovine semen was investigated. Bovine microbial pathogens suspended in tissue culture medium and/or PBS and also added to bovine semen were exposed to the photosensitive agents followed by irradiation. Hematoporphyrin, hematoporphyrin derivative and thiopyronine were effective against bovine herpes virus-1, bovine viral diarrhoea virus, Mycoplasma bovigenitalium, Mycoplasma canadense, and Ureaplasma diversum in culture media. In addition, thiopyronine was effective against Leptospira pomona. Similar treatments were not effective against Leptospira hardjo, Mycoplasma bovis, or Campylobacter fetus subsp. venerealis. When microorganisms were added to bovine semen, only bovine herpes virus-1 was controlled by the photosensitive agents used at concentrations which did not appear harmful to sperm cells.

  13. An outbreak of food-borne gastroenteritis due to sapovirus among junior high school students.

    Science.gov (United States)

    Usuku, Shuzo; Kumazaki, Makoto; Kitamura, Katsuhiko; Tochikubo, Osamu; Noguchi, Yuzo

    2008-11-01

    The human sapovirus (SaV) causes acute gastroenteritis mainly in infants and young children. A food-borne outbreak of gastroenteritis associated with SaV occurred among junior high school students in Yokohama, Japan, during and after a study trip. The nucleotide sequences of the partial capsid gene derived from the students exhibited 98% homology to a SaV genogroup IV strain, Hu/Angelholm/SW278/2004/SE, which was isolated from an adult with gastroenteritis in Solna, Sweden. An identical nucleotide sequence was detected from a food handler at the hotel restaurant, suggesting that the causative agent of the outbreak was transmitted from the food handler. This is the first description of a food-borne outbreak associated with the SaV genogroup IV strain in Japan.

  14. Salt induces biosynthesis of hemolytically active compounds in the xerotolerant food-borne fungus Wallemia sebi.

    Science.gov (United States)

    Botić, Tanja; Kunčič, Marjetka K; Sepčić, Kristina; Knez, Zeljko; Gunde-Cimerman, Nina

    2012-01-01

    Wallemia sebi is a xerotolerant, ubiquitous, food-borne, mycotoxigenic fungus. An ethanol extract of its mycelium demonstrated a strong hemolytic activity, which was further enhanced at high salt concentrations in the growth medium. Characterization of the extract using gas chromatography-mass spectrometry revealed a mixture of sterols and unsaturated fatty acids, indicating the latter as responsible for the hemolytic activity. The lytic activity of the extract is here studied using red blood cells and artificial small lipid vesicles with various lipid compositions. This shows concentration-dependent hemolysis and preferential activity toward lipid membranes with greater fluidity. The W. sebi lytic activity on mammalian erythrocytes shows its potential involvement in the formation of lesions in subcutaneous infections, in farmer's lung disease, and in consumption of food and feed that are contaminated with food-borne W. sebi. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  15. 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.

  16. Inactivation of foodborne pathogenic and spoilage micro-organisms using ultraviolet-A light in combination with ferulic acid.

    Science.gov (United States)

    Shirai, A; Watanabe, T; Matsuki, H

    2017-02-01

    The low energy of UV-A (315-400 nm) is insufficient for disinfection. To improve UV-A disinfection technology, we evaluated the effect of ferulic acid (FA) addition on disinfection by UV-A light-emitting diode (LED) (350-385 nm) against various food spoilers and pathogens (seven bacteria and four fungi species). Photoantimicrobial assays were performed at FA concentrations below the MIC. The MIC of the isomerized FA, consisting of 93% cis-form and 7% trans-form, was very similar to that of the commercially available FA (trans-form). Irradiation with UV-A (1·0 J cm -2 ) in the presence of 100 mg l -1 FA resulted in enhanced reducing of all of the tested bacterial strains. A combination of UV-A (10 J cm -2 ) and 1000 mg l -1 FA resulted in enhanced reducing of Saccharomyces cerevisiae and one of the tested filamentous fungi. These results demonstrated that the combination of a short-term application of UV-A and FA at a low concentration yielded synergistic enhancement of antimicrobial activity, especially against bacteria. Microbial contamination is one of the most serious problems for foods, fruit and sugar thick juices. UV light is suitable for the nonthermal decontamination of food products by inactivating the contaminating micro-organisms. However, UV-A exposure is insufficient for disinfection. This study demonstrates that the combination of UV-A LED light (350-385 nm), which is not hazardous to human eyes and skin, and ferulic acid (FA), a known phytochemical and food additive, provides synergistic antimicrobial activity against foodborne pathogenic and spoilage micro-organisms. Therefore, FA addition to UV-A light treatment may be useful for improvement of UV-A disinfection technology to prevent food deterioration. © 2016 The Society for Applied Microbiology.

  17. 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.

  18. Use of irradiation to control infectivity of food-borne parasites

    International Nuclear Information System (INIS)

    1993-01-01

    Food-borne parasitic diseases are common throughout the world, pose significant health problems and cause economic losses in terms of agricultural commodities and human productivity. The diseases usually occur through consumption of raw or partially cooked foods with are infected by various parasites (e.g. tapeworms, roundworms, flukes, parasitic protozoa, etc.). The problem is significant in developing countries where the population has the habit of consuming raw food of animal origin. Available data, with the exception of data on Trichinella spiralis, a parasitic nematode, were insufficient for the use of irradiation technology to control food-borne parasites. Therefore, a Co-ordinated Research Programme (CRP) on the Use of Irradiation to Control Infectivity of Food-Borne Parasites was implemented by the FAO/IAEA in 1986. The results of the work carried out over five years (1986-1991) by twelve researchers participating in the programme, have established conclusively the potential for application of food irradiation in the control of liver flukes, tapeworms, roundworms, trichinosis, toxoplasmosis, etc. This report includes the conclusions and recommendations of the participants concerning the results obtained and need for further research. Refs, figs and tabs

  19. New Irradiation Method with Indocyanine Green-Loaded Nanospheres for Inactivating Periodontal Pathogens.

    Science.gov (United States)

    Sasaki, Yasuyuki; Hayashi, Jun-Ichiro; Fujimura, Takeki; Iwamura, Yuki; Yamamoto, Genta; Nishida, Eisaku; Ohno, Tasuku; Okada, Kosuke; Yamamoto, Hiromitsu; Kikuchi, Takeshi; Mitani, Akio; Fukuda, Mitsuo

    2017-01-13

    Antimicrobial photodynamic therapy (aPDT) has been proposed as an adjunctive strategy for periodontitis treatments. However, use of aPDT for periodontal treatment is complicated by the difficulty in accessing morphologically complex lesions such as furcation involvement, which the irradiation beam (which is targeted parallel to the tooth axis into the periodontal pocket) cannot access directly. The aim of this study was to validate a modified aPDT method that photosensitizes indocyanine green-loaded nanospheres through the gingivae from outside the pocket using a diode laser. To establish this trans-gingival irradiation method, we built an in vitro aPDT model using a substitution for gingivae. Irradiation conditions and the cooling method were optimized before the bactericidal effects on Porphyromonas gingivalis were investigated. The permeable energy through the gingival model at irradiation conditions of 2 W output power in a 50% duty cycle was comparable with the transmitted energy of conventional irradiation. Intermittent irradiation with air cooling limited the temperature increase in the gingival model to 2.75 °C. The aPDT group showed significant bactericidal effects, with reductions in colony-forming units of 99.99% after 5 min of irradiation. This effect of aPDT against a periodontal pathogen demonstrates the validity of trans-gingival irradiation for periodontal treatment.

  20. New Irradiation Method with Indocyanine Green-Loaded Nanospheres for Inactivating Periodontal Pathogens

    Directory of Open Access Journals (Sweden)

    Yasuyuki Sasaki

    2017-01-01

    Full Text Available Antimicrobial photodynamic therapy (aPDT has been proposed as an adjunctive strategy for periodontitis treatments. However, use of aPDT for periodontal treatment is complicated by the difficulty in accessing morphologically complex lesions such as furcation involvement, which the irradiation beam (which is targeted parallel to the tooth axis into the periodontal pocket cannot access directly. The aim of this study was to validate a modified aPDT method that photosensitizes indocyanine green-loaded nanospheres through the gingivae from outside the pocket using a diode laser. To establish this trans-gingival irradiation method, we built an in vitro aPDT model using a substitution for gingivae. Irradiation conditions and the cooling method were optimized before the bactericidal effects on Porphyromonas gingivalis were investigated. The permeable energy through the gingival model at irradiation conditions of 2 W output power in a 50% duty cycle was comparable with the transmitted energy of conventional irradiation. Intermittent irradiation with air cooling limited the temperature increase in the gingival model to 2.75 °C. The aPDT group showed significant bactericidal effects, with reductions in colony-forming units of 99.99% after 5 min of irradiation. This effect of aPDT against a periodontal pathogen demonstrates the validity of trans-gingival irradiation for periodontal treatment.

  1. 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

  2. [Pathogen inactivation in fresh frozen plasma using riboflavin and ultraviolet light: effects on plasma proteins and coagulation factor VII].

    Science.gov (United States)

    Stanojković, Zoran; Antić, Ana

    2011-01-01

    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. 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. Plasma inactivated by riboflavin and UV rays (Mirasol PRT system, Caridian BCT, U.S.A.) keeps all the characteristics of conventional plasma

  3. Photodynamic treatment with mono-phenyl-tri-(N-methyl-4-pyridyl)-porphyrin for pathogen inactivation in cord blood stem cell products.

    Science.gov (United States)

    Trannoy, Laurence L; van Hensbergen, Yvette; Lagerberg, Johan W M; Brand, Anneke

    2008-12-01

    Hematopoietic stem cell transplants and culture of hematopoietic progenitor cells require pathogen-free conditions. The application of a method of pathogen inactivation in red blood cells using photodynamic treatment (PDT) was investigated for the decontamination of cord blood stem cell (CBSC) products. CBSC products, spiked with Gram-positive and Gram-negative bacteria, were treated with PDT using mono-phenyl-tri-(N-methyl-4-pyridyl)-porphyrin (Tri-P(4)) and red light. After PDT, in vitro and in vivo evaluation of the CBSC functions were performed. PDT of CBSC products resulted in the inactivation of the bacteria, with Staphylococcus aureus being the most resistant. Complete decontamination was achieved when CBSC products were contaminated with low titers of bacteria. PDT had no effect on white blood cell viability, the ex vivo expansion potential of the progenitor cells, and their capacity to differentiate to various hematopoietic cell lineages. However, PDT reduced the engraftment of human CBSCs in NOD/SCID mice, particularly affecting the B-cell lineage engraftment. Pathogen inactivation of CBSC with Tri-P(4)-mediated PDT is feasible at contamination level up to 10 to 20 colony-forming units per mL and can be considered when ex vivo expansion culture is anticipated. However, this treatment is not recommended for transplantation purposes at this time. Further investigations may elucidate why engraftment is diminished.

  4. Antibacterial activity of sphagnum acid and other phenolic compounds found in Sphagnum papillosum against food-borne bacteria.

    Science.gov (United States)

    Mellegård, H; Stalheim, T; Hormazabal, V; Granum, P E; Hardy, S P

    2009-07-01

    To identify the phenolic compounds in the leaves of Sphagnum papillosum and examine their antibacterial activity at pH appropriate for the undissociated forms. Bacterial counts of overnight cultures showed that whilst growth of Staphylococcus aureus 50084 was impaired in the presence of milled leaves, the phenol-free fraction of holocellulose of S. papillosum had no bacteriostatic effect. Liquid chromatography-mass spectrometry analysis of an acetone-methanol extract of the leaves detected eight phenolic compounds. Antibacterial activity of the four dominating phenols specific to Sphagnum leaves, when assessed in vitro as minimal inhibitory concentrations (MICs), were generally >2.5 mg ml(-1). MIC values of the Sphagnum-specific compound 'sphagnum acid' [p-hydroxy-beta-(carboxymethyl)-cinnamic acid] were >5 mg ml(-1). No synergistic or antagonistic effects of the four dominating phenols were detected in plate assays. Sphagnum-derived phenolics exhibit antibacterial activity in vitro only at concentrations far in excess of those found in the leaves. We have both identified the phenolic compounds in S. papillosum and assessed their antibacterial activity. Our data indicate that phenolic compounds in isolation are not potent antibacterial agents and we question their potency against food-borne pathogens.

  5. Granulin Secreted by the Food-Borne Liver Fluke Opisthorchis viverrini Promotes Angiogenesis in Human Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Brandon Haugen

    2018-02-01

    Full Text Available The liver fluke Opisthorchis viverrini is a food-borne, zoonotic pathogen endemic to Thailand and adjacent countries in Southeast Asia. The adult developmental stage of the O. viverrini parasite excretes and secretes numerous proteins within the biliary tract including the gall bladder. Lesions caused by the feeding activities of the liver fluke represent wounds that undergo protracted cycles of healing and re-injury during chronic infection, which can last for decades. Components of the excretory/secretory (ES complement released by the worms capably drive proliferation of bile duct epithelial cells and are implicated in establishing the oncogenic milieu that leads to bile duct cancer, cholangiocarcinoma. An ES protein, the secreted granulin-like growth factor termed Ov-GRN-1, accelerates wound resolution in mice and in vitro. To investigate angiogenesis (blood vessel development that may contribute to wound healing promoted by liver fluke granulin and, by implication, to carcinogenesis during chronic opisthorchiasis, we employed an in vitro tubule formation assay (TFA where human umbilical vein endothelial cells were grown on gelled basement matrix. Ten and 40 nM Ov-GRN-1 significantly stimulated angiogenesis as monitored by cellular proliferation and by TFA in real time. This demonstration of potent angiogenic property of Ov-GRN-1 bolsters earlier reports on the therapeutic potential for chronic non-healing wounds of diabetics, tobacco users, and the elderly and, in addition, showcases another of the hallmark of cancer characteristic of this carcinogenic liver fluke.

  6. Genetic diversity among food-borne and waterborne norovirus strains causing outbreaks in Sweden.

    Science.gov (United States)

    Lysén, Maria; Thorhagen, Margareta; Brytting, Maria; Hjertqvist, Marika; Andersson, Yvonne; Hedlund, Kjell-Olof

    2009-08-01

    A total of 101 food-borne and waterborne outbreaks that were caused by norovirus and that resulted in more than 4,100 cases of illness were reported to the Swedish Institute for Infectious Disease Control from January 2002 to December 2006. Sequence and epidemiological data for isolates from 73 outbreaks were analyzed. In contrast to health care-related outbreaks, no clear seasonality could be observed. Sequence analysis showed a high degree of genetic variation among the noroviruses detected. Genogroup II (GII) viruses were detected in 70% of the outbreaks, and of those strains, strains of GII.4 were the most prevalent and were detected in 25% of all outbreaks. The GII.4 variants detected in global outbreaks in health care settings during 2002, 2004, and 2006 were also found in the food-borne outbreaks. GI strains totally dominated as the cause of water-related (drinking and recreational water) outbreaks and were found in 12 of 13 outbreaks. In 14 outbreaks, there were discrepancies among the polymerase and capsid genotype results. In four outbreaks, the polymerase of the recombinant GII.b virus occurred together with the GII.1 or GII.3 capsids, while the GII.7 polymerase occurred together with the GII.6 and GII.7 capsids. Mixed infections were observed in six outbreaks; four of these were due to contaminated water, and two were due to imported frozen berries. Contaminated food and water serve as important reservoirs for noroviruses. The high degree of genetic diversity found among norovirus strains causing food-borne and waterborne infections stresses the importance of the use of broad reaction detection methods when such outbreaks are investigated.

  7. 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.

  8. Inactivation and potential reactivation of pathogenic Escherichia coli O157:H7 in apple juice following ultraviolet light exposure at three monochromatic wavelengths.

    Science.gov (United States)

    Yin, Fugui; Zhu, Yan; Koutchma, Tatiana; Gong, Joshua

    2015-04-01

    Ultraviolet (UV) light irradiation at 254 nm is considered as a novel non-thermal method for decontamination of foodborne pathogenic bacteria. However, lower penetration depth of UV light at 254 nm in apple juice resulted in higher UV dose consumption during apple juice decontamination. In addition, no studies are available on the reactivation of pathogens following exposure to UV light in drinks and beverages. Two novel monochromatic UV light sources (λ = 222 and 282 nm) have been developed for bacterial disinfection. However, the inactivation of pathogenic Escherichia coli O157:H7 following exposure to these UV wavelengths is still unclear. Therefore, the present study was conducted to determine the inactivation and reactivation potential of pathogenic E. coli O157:H7 in apple juice following exposure to UV light at three monochromatic wavelengths: Far UV (λ = 222 nm), Far UV+ (λ = 282 nm) and UVC light (λ = 254 nm). The results showed that E. coli O157:H7 is acid-resistant, and up to 99.50% of cells survived in apple juice when incubated at 20 °C for 24 h. Inactivation of E. coli O157:H7 following exposure to Far UV light (2.81 Log reduction) was higher (P light (1.95 Log reduction) and Far UV+ light (1.83 Log reduction) at the similar levels of UV fluence of 75 mJ/cm(2). No any reactivation potential was observed for E. coli O157:H7 in dark incubation phases after exposure to UV light as determined by the regular plating method. In addition, the exposure to Far UV light at 222 nm followed by incubating at 37 °C significantly decreased (P light. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Food-borne disease and climate change in the United Kingdom.

    Science.gov (United States)

    Lake, Iain R

    2017-12-05

    This review examined the likely impact of climate change upon food-borne disease in the UK using Campylobacter and Salmonella as example organisms. Campylobacter is an important food-borne disease and an increasing public health threat. There is a reasonable evidence base that the environment and weather play a role in its transmission to humans. However, uncertainty as to the precise mechanisms through which weather affects disease, make it difficult to assess the likely impact of climate change. There are strong positive associations between Salmonella cases and ambient temperature, and a clear understanding of the mechanisms behind this. However, because the incidence of Salmonella disease is declining in the UK, any climate change increases are likely to be small. For both Salmonella and Campylobacter the disease incidence is greatest in older adults and young children. There are many pathways through which climate change may affect food but only a few of these have been rigorously examined. This provides a high degree of uncertainty as to what the impacts of climate change will be. Food is highly controlled at the National and EU level. This provides the UK with resilience to climate change as well as potential to adapt to its consequences but it is unknown whether these are sufficient in the context of a changing climate.

  10. Campylobacter jejuni : A brief overview on pathogenicity-associated factors and disease-mediating mechanisms

    NARCIS (Netherlands)

    Dasti, Javid I.; Tareen, A. Malik; Lugert, Raimond; Zautner, Andreas E.; Gross, Uwe

    Campylobacter jejuni has long been recognized as a cause of bacterial food-borne illness, and surprisingly, it remains the most prevalent bacterial food-borne pathogen in the industrial world to date. Natural reservoirs for this Gram-negative, spiral-shaped bacterium are wild birds, whose intestines

  11. Bioprotective properties of seaweeds: In vitro evaluation of antioxidant activity and antimicrobial activity against food borne bacteria in relation to polyphenolic content

    Directory of Open Access Journals (Sweden)

    Kesika Periyanaina

    2008-07-01

    Full Text Available Abstract Background For many years chemical preservatives have been used in food, to act as either antimicrobials or antioxidants or both. In general, consumers regard additive-free foods as safer since preservatives can cause health hazards like asthma and cancer and are suspected to be mutagenic and neurotoxic. The present study was carried out to evaluate the antimicrobial and antioxidant activity of methanolic extracts of seaweeds, with a view to developing safer food preservatives. Methods Ten edible seaweeds, which have wide pharmaceutical application, were collected from Central Marine Fisheries Research Institute, Tamil Nadu, India and evaluated for antioxidant and antimicrobial activity against food borne pathogens. Results The results indicate that Gelidiella acerosa has the highest antioxidant activity while Haligra sps exhibited antibacterial activity against Staphylococcus aureus (MTCC 96. Conclusion Quantitative analysis of the total phenolic content of the seaweeds indicated that Gelidella acerosa and Haligra sps have high phenolic contents, which correlated to their respective antioxidant and antimicrobial activity

  12. 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.

  13. Determination of histamine in milkfish stick implicated in food-borne poisoning.

    Science.gov (United States)

    Lee, Yi-Chen; Kung, Hsien-Feng; Wu, Chien-Hui; Hsu, Hui-Mei; Chen, Hwi-Chang; Huang, Tzou-Chi; Tsai, Yung-Hsiang

    2016-01-01

    An incident of food-borne poisoning causing illness in 37 victims due to ingestion of fried fish sticks occurred in September 2014, in Tainan city, southern Taiwan. Leftovers of the victims' fried fish sticks and 16 other raw fish stick samples from retail stores were collected and tested to determine the occurrence of histamine and histamine-forming bacteria. Two suspected fried fish samples contained 86.6 mg/100 g and 235.0 mg/100 g histamine; levels that are greater than the potential hazard action level (50 mg/100 g) in most illness cases. Given the allergy-like symptoms of the victims and the high histamine content in the suspected fried fish samples, this food-borne poisoning was strongly suspected to be caused by histamine intoxication. Moreover, the fish species of suspected samples was identified as milkfish (Chanos chanos), using polymerase chain reaction direct sequence analysis. In addition, four of the 16 commercial raw milkfish stick samples (25%) had histamine levels greater than the US Food & Drug Administration guideline of 5.0 mg/100 g for scombroid fish and/or products. Ten histamine-producing bacterial strains, capable of producing 373-1261 ppm of histamine in trypticase soy broth supplemented with 1.0% L-histidine, were identified as Enterobacter aerogenes (4 strains), Enterobacter cloacae (1 strain), Morganella morganii (2 strains), Serratia marcescens (1 strain), Hafnia alvei (1 strain), and Raoultella orithinolytica (1 strain), by 16S ribosomal DNA sequencing with polymerase chain reaction amplification. Copyright © 2015. Published by Elsevier B.V.

  14. Determination of histamine in milkfish stick implicated in food-borne poisoning

    Directory of Open Access Journals (Sweden)

    Yi-Chen Lee

    2016-01-01

    Full Text Available An incident of food-borne poisoning causing illness in 37 victims due to ingestion of fried fish sticks occurred in September 2014, in Tainan city, southern Taiwan. Leftovers of the victims' fried fish sticks and 16 other raw fish stick samples from retail stores were collected and tested to determine the occurrence of histamine and histamine-forming bacteria. Two suspected fried fish samples contained 86.6 mg/100 g and 235.0 mg/100 g histamine; levels that are greater than the potential hazard action level (50 mg/100 g in most illness cases. Given the allergy-like symptoms of the victims and the high histamine content in the suspected fried fish samples, this food-borne poisoning was strongly suspected to be caused by histamine intoxication. Moreover, the fish species of suspected samples was identified as milkfish (Chanos chanos, using polymerase chain reaction direct sequence analysis. In addition, four of the 16 commercial raw milkfish stick samples (25% had histamine levels greater than the US Food & Drug Administration guideline of 5.0 mg/100 g for scombroid fish and/or products. Ten histamine-producing bacterial strains, capable of producing 373–1261 ppm of histamine in trypticase soy broth supplemented with 1.0% L-histidine, were identified as Enterobacter aerogenes (4 strains, Enterobacter cloacae (1 strain, Morganella morganii (2 strains, Serratia marcescens (1 strain, Hafnia alvei (1 strain, and Raoultella orithinolytica (1 strain, by 16S ribosomal DNA sequencing with polymerase chain reaction amplification.

  15. 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

  16. 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.

  17. Effect of Ozone Treatment on Inactivation of Escherichia coli and Listeria sp. on Spinach

    Directory of Open Access Journals (Sweden)

    Shreya Wani

    2015-03-01

    Full Text Available The efficacy of “gaseous” ozone in reducing numbers and re-growth of food-borne pathogens, (Escherichia coli and Listeria spp., on leafy salads was investigated using spinach. A preliminary in vivo study showed 1-log reduction in six strains of E. coli and two species of Listeria spp. on spinach exposed to 1 ppm ozone for 10 min. A range of ozone treatments were explored to deliver optimal bacterial inactivation while maintaining the visual appearance (color of produce. Exposure to a higher ozone concentration for a shorter duration (10 ppm for 2 min significantly reduced E. coli and Listeria spp. viable counts by 1-log and the pathogens did not re-grow following treatment (over a nine-day storage period. Impacts of 1 and 10 ppm ozone treatments were not significantly different. Approximately 10% of the pathogen population was resistant to ozone treatment. We hypothesized that cell age may be one of several factors responsible for variation in ozone resistance. E. coli cells from older colonies demonstrated higher ozone resistance in subsequent experiments. Overall, we speculate that gaseous ozone treatment constitutes the basis for an alternative customer-friendly method to reduce food pathogen contamination of leafy produce and is worth exploring on a pilot-scale in an industrial setting.

  18. PulseNet International: Vision for the implementation of whole genome sequencing (WGS) for global food-borne disease surveillance.

    NARCIS (Netherlands)

    Nadon, Celine; Van Walle, Ivo; Gerner-Smidt, Peter; Campos, Josefina; Chinen, Isabel; Concepcion-Acevedo, Jeniffer; Gilpin, Brent; Smith, Anthony M; Man Kam, Kai; Perez, Enrique; Trees, Eija; Kubota, Kristy; Takkinen, Johanna; Nielsen, Eva Møller; Carleton, Heather

    2017-01-01

    PulseNet International is a global network dedicated to laboratory-based surveillance for food-borne diseases. The network comprises the national and regional laboratory networks of Africa, Asia Pacific, Canada, Europe, Latin America and the Caribbean, the Middle East, and the United States. The

  19. Validation of a PCR-based method for detection of food-borne thermotolerant Campylobacters in a multicenter collaborative trial

    DEFF Research Database (Denmark)

    Josefsen, Mathilde Hartmann; Cook, N.; D'Agostino, M.

    2004-01-01

    A PCR-based method for rapid detection of food-borne thermotolerant campylobacters was evaluated through a collaborative trial with 12 laboratories testing spiked carcass rinse samples. The method showed an interlaboratory diagnostic sensitivity of 96.7% and a diagnostic specificity of 100...

  20. 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.

  1. Control of food-borne molds by combination of heat and radiation

    International Nuclear Information System (INIS)

    Padwal-Desai, S.R.; Bongirwar, D.R.

    1979-01-01

    After enumerating the fungi responsible for food spoilage, work done on the factors influencing growth of fungi in stored foods is reviewed and the methods using heat, radiation or chemicals for control of food-borne molds are briefly surveyed. Work on combination process employing heat treatment and radiation treatment is reviewed in detail. The review covers the following aspects: (1) theory and engineering aspects of combination process of heat and radiation including modes of heat transfer, radiation physics, radiation sources, heat radiation effect and calculation of energy balance of the process, (2) biological effects of heat, radiation and heat-radiation combination treatments on mold growth with special reference to DNA and (3) application of the process for mold control in cereal products, nuts and raisins and fruits. Heat treatment and radiation treatment have been found to complement each other and when given in proper sequence show synergism. Design requirements of radiation sources and heat transfer equipment are also surveyed. (M.G.B.)

  2. Protective efficacy of recombinant and inactivated H5 avian influenza vaccines against challenge from the 2014 intercontinental H5 highly pathogenic avian influenza viruses (H5N8 and H5N2)

    Science.gov (United States)

    Protective immunity against highly pathogenic avian influenza (HPAI) largely depends on the development of an antibody response against a specific subtype of challenge virus. Historically, the use of antigenically closely matched isolates has proven efficacious when used as inactivated vaccines. M...

  3. Updated recommendations for heat inactivation of high pathogenicity avian influenza virus in dried egg white for import/export purposes

    Science.gov (United States)

    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 marketi...

  4. Outbreak of food borne Salmonella among guests of a wedding ceremony: The role of cultural factors

    Directory of Open Access Journals (Sweden)

    Abdullah S Aljoudi

    2010-01-01

    Full Text Available Objective: In response to a large number of cases of gastroenteritis reporting to Sulyyel hospital, an outbreak investigation was conducted to identify its source, to assess its extent and to make recommendations on the prevention of such outbreaks in the future. Material and Methods: A case was defined as any individual who developed diarrhea with any of the following symptoms: Abdominal pain, fever or vomiting within three days of eating at the wedding ceremony. A retrospective cohort study was conducted to identify food items and circumstances responsible for this outbreak. Results: A total of 283 individuals were interviewed, 88 of whom developed gastroenteritis, most commonly manifested by diarrhea (100%, abdominal pain (94.3% and fever (86.4%. The majority of persons interviewed were Saudis (89.1% and 21.6% were males. The median incubation period was 20.6 ΁ 2.77 hours and the epidemic curve suggested a common point source outbreak. Out of 9 food items and drinks served at the wedding ceremony, 3 food items were significantly associated with illness: meat ranked first (RR=16.7, 95% CI=2.37-115.8, followed by rice (RR=13.6 95% CI=1.95-93.61, and restaurant made sweets (RR=1.9, 95% CI=1.35-2.58. Out of 62 stool samples collected from cases, 40 (64.5 % grew Salmonella group C non-typhoid. Conclusion: Salmonella was considered the causative agent of this food-borne outbreak. Meat and rice served at the wedding party were the food items incriminated. Time, temperature misuse, inadequate heat treatment, and unhygienic handling were the most important factors causing this outbreak.

  5. Outbreak of food borne Salmonella among guests of a wedding ceremony: The role of cultural factors.

    Science.gov (United States)

    Aljoudi, Abdullah S; Al-Mazam, Abdulaziz; Choudhry, Abdul J

    2010-01-01

    In response to a large number of cases of gastroenteritis reporting to Sulyyel hospital, an outbreak investigation was conducted to identify its source, to assess its extent and to make recommendations on the prevention of such outbreaks in the future. A CASE WAS DEFINED AS ANY INDIVIDUAL WHO DEVELOPED DIARRHEA WITH ANY OF THE FOLLOWING SYMPTOMS: Abdominal pain, fever or vomiting within three days of eating at the wedding ceremony. A retrospective cohort study was conducted to identify food items and circumstances responsible for this outbreak. A total of 283 individuals were interviewed, 88 of whom developed gastroenteritis, most commonly manifested by diarrhea (100%), abdominal pain (94.3%) and fever (86.4%). The majority of persons interviewed were Saudis (89.1%) and 21.6% were males. The median incubation period was 20.6 ± 2.77 hours and the epidemic curve suggested a common point source outbreak. Out of 9 food items and drinks served at the wedding ceremony, 3 food items were significantly associated with illness: meat ranked first (RR=16.7, 95% CI=2.37-115.8), followed by rice (RR=13.6 95% CI=1.95-93.61), and restaurant made sweets (RR=1.9, 95% CI=1.35-2.58). Out of 62 stool samples collected from cases, 40 (64.5 %) grew Salmonella group C non-typhoid. Salmonella was considered the causative agent of this food-borne outbreak. Meat and rice served at the wedding party were the food items incriminated. Time, temperature misuse, inadequate heat treatment, and unhygienic handling were the most important factors causing this outbreak.

  6. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards) , 2013 . Scientific Opinion on the evaluation of molecular typing methods for major food-borne microbiological hazards and their use for attribution modelling, outbreak investigation and scanning surveillance: Part 1 (evaluation of methods

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    An evaluation of molecular typing methods that can be applied to the food-borne pathogens Salmonella, Campylobacter, Shiga toxin-producing Escherichia coli and Listeria monocytogenes is presented. This evaluation is divided in two parts. Firstly, commonly used molecular typing methods are assessed...... against a set of predefined criteria relating to discriminatory capacity, reproducibility, repeatability and current or potential suitability for international harmonisation. Secondly, the methods are evaluated for their appropriateness for use in different public health-related applications...... and potential for use of molecular characterisation methods, including whole genome sequencing technologies, in microbial food safety. Recommendations are also made in order to encourage a holistic and structured approach to the use of molecular characterisation methods for food-borne pathogens; in particular...

  7. Methods for detecting pathogens in the beef food chain: detecting particular pathogens

    Science.gov (United States)

    The main food-borne pathogens of concern in the beef food chain are Shiga toxin-producing Escherichia coli (STEC) and Salmonella spp.; however, the presence of other pathogens, including Listeria monocytogenes, Campylobacter spp., Clostridium spp., Bacillus cereus, and Mycobacterium avium subsp. par...

  8. 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.

  9. 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.

  10. 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.

  11. Evaluation of different extraction methods on antimicrobial potency of Adenium obesum stem against food borne pathogenic bacterial strains in Oman

    OpenAIRE

    Mohammad Amzad Hossain; Tahiya Hilal Ali Al-Abri; Amira Hamood Salim Al-Musalami; Md. Sohail Akhtar; Sadri Said

    2014-01-01

    Objective: To determine and compare the effect on antimicrobial potency of crude stems extract of Adenium obesum (A. obesum) by Soxhlet and maceration extraction methods. Methods: The crude extracts were prepared from the coarse samples of stems with methanol by using Soxhlet and maceration extraction methods. Both the crude extracts from two extraction methods were dissolved in water and successively extracted by different polarities solvents with increasing polarities. In vit...

  12. Association between the Hygiene Index Values of Live Fresh Aquatic Products and Food-Borne Diarrhea in the Population of the Ningbo Area in China.

    Science.gov (United States)

    Zhang, Lijun; Lu, Lu; Shu, Liye; Chen, Jianjun; Zou, Baobo; Zhou, Qi; Gu, Yuanliang; Zhao, Jinshun; Lin, Xialu

    2015-08-06

    To investigate the association of the hygiene index values of live fresh aquatic products and food-borne diarrhea in the population of the Ningbo area in China. Volatile basic nitrogen (VBN), histamine (HIS), indole, tetrodotoxin (TTX), and paralytic, neurotoxic, amnesic and diarrhetic shellfish poisons (PSP, NSP, ASP, and DSP, respectively) in the samples of live fresh aquatic products and food-borne diarrhea cases in six studied districts were analyzed. Results indicate that the incidence rate of food-borne diarrhea is related to the hygiene index values. Aside from VBN, the main risk factors related to food-borne diarrhea in edible aquatic products include DSP (in marine fish, shrimp, and other shellfishes), NSP, and ASP (in marine shrimp and crab). Hygiene index values among different species were significantly different. No significant difference in the monitoring index values was found among the six different studied districts. The reported cases of food-borne diarrhea were positively associated with VBN and DSP in aquatic products in Haishu, Jiangbei, Zhenhai, and Beilun, as well as VBN and NSP in aquatic products in Jiangdong and Yinzhou. In conclusion, VBN, DSP, NSP, and ASP are important risk factors for the occurring of food-borne diarrhea in the population of the Ningbo area in China.

  13. Food-borne zoonoses, the EU zoonosis legislation and the prospects for food safety and consumer protection during primary animal production.

    Science.gov (United States)

    Smulders, Frans J M; Vågsholm, Ivar; Korkeala, Hannu

    2008-01-01

    Zoonoses are diseases that are transmitted naturally between animals and humans. The control of food-borne zoonoses within the European Union is a prerequisite for assuring a functional internal market and consequently represents an important item on the political agenda. Unfortunately, until recently, gaining a clear view of the current incidence of food-borne zoonoses and the prevalence of its causative agents has been frustrated by the absence of reliable monitoring and reporting systems. Similarly, it has become clear that, Europe wide, one has witnessed only limited success with regard to the control of important food-borne agents such as Salmonella spp. The European Union has adopted legislation to remedy this situation and to control food-borne zoonoses in primary production. This contribution discusses the incentives for introducing EU Directive 2003/99/EC and EU Regulation No. 2160/2003, summarises their essentials and discusses major ramifications of both pieces of legislation for the prevention of food-borne zoonoses. It is concluded that there is reason for cautious optimism concerning human salmonellosis, while for other food-borne zoonoses there should be a call for action.

  14. 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 (< 0.5 log decrease of viable cells). The photodynamic response for planktonic cultured 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.

  15. In vitro function of platelets treated with ultraviolet C light for pathogen inactivation: a comparative study with nonirradiated and gamma-irradiated platelets.

    Science.gov (United States)

    Tynngård, Nahreen; Trinks, Marie; Berlin, Gösta

    2015-06-01

    During storage of platelet concentrates (PCs) replication of contaminating pathogens might occur, which can be prevented by various pathogen inactivation (PI) methods using photoactive substances in combination with ultraviolet (UV) light. A new method uses only UVC light for PI without photoactive substances. This study evaluates the in vitro function, including hemostatic properties (clot formation and elasticity), of platelets (PLTs) treated with UVC light. A PC with 35% plasma and 65% PLT additive solution (SSP+) was prepared from five buffy coats. Three PCs were pooled and divided into 3 units. One unit was used as a nonirradiated control, the second was a gamma-irradiated control, and the third unit was treated with UVC light. In vitro variables including analysis of coagulation by free oscillation rheometry were analyzed on Days 1, 5, and 7 of storage. Ten units in each group were investigated. Swirling was well preserved, and the pH level was higher than the reference limit (6.4) during storage of PLTs in all groups. Glycolysis and PLT activation were higher for UVC-treated PLTs but the clot-forming capacity was unaffected. However, immediately after UVC treatment, the clot elastic properties were slightly affected. Hypotonic shock response decreased immediately after UVC treatment but recovered partly during the storage period. UVC treatment affected the in vitro properties, but PLT quality and storage stability were well preserved for up to 7 days, and the in vitro hemostatic capacity of UVC-treated PLTs was only minimally altered. The clinical relevance of these changes needs to be evaluated in controlled trials. © 2014 AABB.

  16. Modeling the Inactivation of Intestinal Pathogenic Escherichia coli O157:H7 and Uropathogenic E. coli in Ground Chicken by High Pressure Processing and Thymol.

    Science.gov (United States)

    Chien, Shih-Yung; Sheen, Shiowshuh; Sommers, Christopher H; Sheen, Lee-Yan

    2016-01-01

    Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compared the resistance of iPEC (O157:H7) to UPEC in chicken meat using High Pressure Processing (HPP) in with (the hurdle concept) and without thymol essential oil as a sensitizer. UPEC was found slightly more resistant than E. coli O157:H7 (iPEC O157:H7) at 450 and 500 MPa. A central composite experimental design was used to evaluate the effect of pressure (300-400 MPa), thymol concentration (100-200 ppm), and pressure-holding time (10-20 min) on the inactivation of iPEC O157:H7 and UPEC in ground chicken. The hurdle approach reduced the high pressure levels and thymol doses imposed on the food matrices and potentially decreased food quality damaged after treatment. The quadratic equations were developed to predict the impact (lethality) on iPEC O157:H7 (R (2) = 0.94) and UPEC (R (2) = 0.98), as well as dimensionless non-linear models [Pr > F (UPEC in regard to how they may survive HPP in the presence or absence of thymol. The models may further assist regulatory agencies and food industry to assess the potential risk of iPEC O157:H7 and UPEC in ground chicken.

  17. Chemical Composition and Antimicrobial Activities of Essential Oils from Nepeta cataria L. against Common Causes of Food-Borne Infections

    OpenAIRE

    Zomorodian, Kamiar; Saharkhiz, Mohammad Jamal; Shariati, Samaneh; Pakshir, Keyvan; Rahimi, Mohammad Javad; Khashei, Reza

    2012-01-01

    Nepeta cataria L. is traditionally consumed as a food additive. The effects of three different harvest stages of N. cataria essential oils (EOs) against most common causes of food-borne infections were evaluated by broth microdilution method as recommended by the Clinical and Laboratory Standards Institute (CLSI). The chemical composition of the EOs from N. cataria has been analyzed by gas chromatography/mass spectrometry (GC/MS). The analysis of the EOs indicated that 4a- α ,7- α ,7a- β -nep...

  18. A European network for food-borne parasites (Euro-FBP: meeting report on ‘Analytical methods for food-borne parasites in human and veterinary diagnostics and in food matrices’

    Directory of Open Access Journals (Sweden)

    Christian Klotz

    2017-11-01

    Full Text Available Abstract Food-borne parasites (FBPs are a neglected topic in food safety, partly due to a lack of awareness of their importance for public health, especially as symptoms tend not to develop immediately after exposure. In addition, methodological difficulties with both diagnosis in infected patients and detection in food matrices result in under-detection and therefore the potential for underestimation of their burden on our societies. This, in consequence, leads to lower prioritization for basic research, e.g. for development new and more advanced detection methods for different food matrices and diagnostic samples, and thus a vicious circle of neglect and lack of progress is propagated. The COST Action FA1408, A European Network for Foodborne Parasites (Euro-FBP aims to combat the impact of FBP on public health by facilitating the multidisciplinary cooperation and partnership between groups of researchers and between researchers and stakeholders. The COST Action TD1302, the European Network for cysticercosis/taeniosis, CYSTINET, has a specific focus on Taenia solium and T. saginata, two neglected FBPs, and aims to advance knowledge and understanding of these zoonotic disease complexes via collaborations in a multidisciplinary scientific network. This report summarizes the results of a meeting within the Euro-FBP consortium entitled ‘Analytical methods for food-borne parasites in human and veterinary diagnostics and in food matrices’ and of the joined Euro-FBP and CYSTINET meeting.

  19. Quantitative risk assessment from farm to fork and beyond: a global Bayesian approach concerning food-borne diseases.

    Science.gov (United States)

    Albert, Isabelle; Grenier, Emmanuel; Denis, Jean-Baptiste; Rousseau, Judith

    2008-04-01

    A novel approach to the quantitative assessment of food-borne risks is proposed. The basic idea is to use Bayesian techniques in two distinct steps: first by constructing a stochastic core model via a Bayesian network based on expert knowledge, and second, using the data available to improve this knowledge. Unlike the Monte Carlo simulation approach as commonly used in quantitative assessment of food-borne risks where data sets are used independently in each module, our consistent procedure incorporates information conveyed by data throughout the chain. It allows "back-calculation" in the food chain model, together with the use of data obtained "downstream" in the food chain. Moreover, the expert knowledge is introduced more simply and consistently than with classical statistical methods. Other advantages of this approach include the clear framework of an iterative learning process, considerable flexibility enabling the use of heterogeneous data, and a justified method to explore the effects of variability and uncertainty. As an illustration, we present an estimation of the probability of contracting a campylobacteriosis as a result of broiler contamination, from the standpoint of quantitative risk assessment. Although the model thus constructed is oversimplified, it clarifies the principles and properties of the method proposed, which demonstrates its ability to deal with quite complex situations and provides a useful basis for further discussions with different experts in the food chain.

  20. Application of bacteriophages in post-harvest control of human pathogenic and food spoiling bacteria.

    Science.gov (United States)

    Pérez Pulido, Rubén; Grande Burgos, Maria José; Gálvez, Antonio; Lucas López, Rosario

    2016-10-01

    Bacteriophages have attracted great attention for application in food biopreservation. Lytic bacteriophages specific for human pathogenic bacteria can be isolated from natural sources such as animal feces or industrial wastes where the target bacteria inhabit. Lytic bacteriophages have been tested in different food systems for inactivation of main food-borne pathogens including Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, Salmonella enterica, Shigella spp., Campylobacter jejuni and Cronobacter sakazkii, and also for control of spoilage bacteria. Application of lytic bacteriophages could selectively control host populations of concern without interfering with the remaining food microbiota. Bacteriophages could also be applied for inactivation of bacteria attached to food contact surfaces or grown as biofilms. Bacteriophages may receive a generally recognized as safe status based on their lack of toxicity and other detrimental effects to human health. Phage preparations specific for L. monocytogenes, E. coli O157:H7 and S. enterica serotypes have been commercialized and approved for application in foods or as part of surface decontamination protocols. Phage endolysins have a broader host specificity compared to lytic bacteriophages. Cloned endolysins could be used as natural preservatives, singly or in combination with other antimicrobials such as bacteriocins.

  1. Detection of human food-borne and zoonotic viruses on irrigated, field-grown strawberries.

    Science.gov (United States)

    Brassard, Julie; Gagné, Marie-Josée; Généreux, Mylène; Côté, Caroline

    2012-05-01

    This study evaluated the presence of pathogenic human and zoonotic viruses on irrigated, field-grown strawberries. Norovirus genogroup I, rotavirus, and swine hepatitis E virus genogroup 3 were detected on strawberries, and irrigation water is suspected as the contamination origin.

  2. Detection of Human Food-Borne and Zoonotic Viruses on Irrigated, Field-Grown Strawberries

    OpenAIRE

    Brassard, Julie; Gagné, Marie-Josée; Généreux, Mylène; Côté, Caroline

    2012-01-01

    This study evaluated the presence of pathogenic human and zoonotic viruses on irrigated, field-grown strawberries. Norovirus genogroup I, rotavirus, and swine hepatitis E virus genogroup 3 were detected on strawberries, and irrigation water is suspected as the contamination origin.

  3. One Health and Food-Borne Disease: Salmonella Transmission between Humans, Animals, and Plants.

    Science.gov (United States)

    Silva, Claudia; Calva, Edmundo; Maloy, Stanley

    2014-02-01

    There are >2,600 recognized serovars of Salmonella enterica. Many of these Salmonella serovars have a broad host range and can infect a wide variety of animals, including mammals, birds, reptiles, amphibians, fish, and insects. In addition, Salmonella can grow in plants and can survive in protozoa, soil, and water. Hence, broad-host-range Salmonella can be transmitted via feces from wild animals, farm animals, and pets or by consumption of a wide variety of common foods: poultry, beef, pork, eggs, milk, fruit, vegetables, spices, and nuts. Broad-host-range Salmonella pathogens typically cause gastroenteritis in humans. Some Salmonella serovars have a more restricted host range that is associated with changes in the virulence plasmid pSV, accumulation of pseudogenes, and chromosome rearrangements. These changes in host-restricted Salmonella alter pathogen-host interactions such that host-restricted Salmonella organisms commonly cause systemic infections and are transmitted between host populations by asymptomatic carriers. The secondary consequences of efforts to eliminate host-restricted Salmonella serovars demonstrate that basic ecological principles govern the environmental niches occupied by these pathogens, making it impossible to thwart Salmonella infections without a clear understanding of the human, animal, and environmental reservoirs of these pathogens. Thus, transmission of S. enterica provides a compelling example of the One Health paradigm because reducing human infections will require the reduction of Salmonella in animals and limitation of transmission from the environment.

  4. 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.

  5. Comparison of three Listeria monocytogenes strains in a guinea-pig model simulating food-borne exposure

    DEFF Research Database (Denmark)

    Roldgaard, Bent; Andersen, Jens Bo; Hansen, Tina Beck

    2009-01-01

    in selected organs were considerably lower for LO28 than for the other two strains. Additionally, the animal study revealed a difference in prevalence in faeces as well as in internal organs between the clinical isolate and the food isolate, which was not reproduced in vitro. Dosage with monocultures......Three different Listeria monocytogenes strains, LO28 (a laboratory strain with truncated InlA), 4446 (a clinical isolate) and 7291 (a food isolate), were compared in a guinea-pig model designed to mimic food-borne exposure. The objectives were (1) to verify the applicability of the animal model...... for distinguishing between Listeria with different virulence properties and (2) to explore whether it was possible to reduce the required number of animals by dosing with mixed cultures instead of monocultures. Consistent with in vitro observations of infectivity in Caco-2 cells, faecal densities and presence...

  6. 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

  7. Inactivation of pathogenic microorganisms in freshwater using HSO5-/UV-A LED and HSO5-/Mn+/UV-A LED oxidation processes.

    Science.gov (United States)

    Rodríguez-Chueca, Jorge; Silva, Tatiana; Fernandes, José R; Lucas, Marco S; Puma, Gianluca Li; Peres, José A; Sampaio, Ana

    2017-10-15

    Freshwater disinfection using photolytic and catalytic activation of peroxymonosulphate (PMS) through PMS/UV-A LED and PMS/M n+ /UV-A LED [M n+  = Fe 2+ or Co 2+ ] processes was evaluated through the inactivation of three different bacteria: Escherichia coli (Gram-negative), Bacillus mycoides (sporulated Gram-positive), Staphylococcus aureus (non-sporulated Gram-positive), and the fungus Candida albicans. Photolytic and catalytic activation of PMS were effective in the total inactivation of the bacteria using 0.1 mM of PMS and M n+ at neutral pH (6.5), with E. coli reaching the highest and the fastest inactivation yield, followed by S. aureus and B. mycoides. With B. mycoides, the oxidative stress generated through the complexity of PMS/M n+ /UV-A LED combined treatments triggered the formation of endospores. The treatment processes were also effective in the total inactivation of C. albicans, although, due to the ultrastructure, biochemistry and physiology of this yeast, higher dosages of reagents (5 mM of PMS and 2.5 mM of M n+ ) were required. The rate of microbial inactivation markedly increased through catalytic activation of PMS particularly during the first 60 s of treatment. Co 2+ was more effective than Fe 2+ to catalyse PMS decomposition to sulphate radicals for the inactivation of S. aureus and C. albicans. The inactivation of the four microorganisms was well represented by the Hom model. The Biphasic and the Double Weibull models, which are based on the existence of two microbial sub-populations exhibiting different resistance to the treatments, also fitted the experimental results of photolytic activation of PMS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Effect of frequency and waveform on inactivation of Escherichia coli O157:H7 and Salmonella enterica Serovar Typhimurium in salsa by ohmic heating.

    Science.gov (United States)

    Lee, Su-Yeon; Ryu, Sangryeol; Kang, Dong-Hyun

    2013-01-01

    The effect of frequency of alternating current during ohmic heating on electrode corrosion, heating rate, inactivation of food-borne pathogens, and quality of salsa was investigated. The impact of waveform on heating rate was also investigated. Salsa was treated with various frequencies (60 Hz to 20 kHz) and waveforms (sine, square, and sawtooth) at a constant electric field strength of 12.5 V/cm. Electrode corrosion did not occur when the frequency exceeded 1 kHz. The heating rate of the sample was dependent on frequency up to 500 Hz, but there was no significant difference (P > 0.05) in the heating rate when the frequency was increased above 1 kHz. The electrical conductivity of the sample increased with a rise in the frequency. At a frequency of 60 Hz, the square wave produced a lower heating rate than that of sine and sawtooth waves. The heating rate between waveforms was not significantly (P > 0.05) different when the frequency was >500 Hz. As the frequency increased, the treatment time required to reduce Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium to below the detection limit (1 log CFU/g) decreased without affecting product quality. These results suggest that ohmic heating can be effectively used to pasteurize salsa and that the effect of inactivation is dependent on frequency and electrical conductivity rather than waveform.

  9. Toward an international standard for PCR-based detection of food-borne thermotolerant campylobacters: Validation in a multicenter collaborative trial

    DEFF Research Database (Denmark)

    Lübeck, Peter Stephensen; Cook, N.; Wagner, M.

    2003-01-01

    As part of a European research project, the performance of a PCR assay to detect food-borne thermotolerant campylobacters (Campylobacter jejuni, C. coli, and C. lari) was evaluated through an international collaborative trial involving 12 participating laboratories. DNA from 10 target and 8...

  10. Evolution of class 1 integrons: Mobilization and dispersal via food-borne bacteria.

    Directory of Open Access Journals (Sweden)

    Timothy M Ghaly

    Full Text Available Class 1 integrons have played a major role in the global dissemination of antibiotic resistance. Reconstructing the history of class 1 integrons might help us control further spread of antibiotic resistance by understanding how human activities influence microbial evolution. Here we describe a class 1 integron that represents an intermediate stage in the evolutionary history of clinical integrons. It was embedded in a series of nested transposons, carried on an IncP plasmid resident in Enterobacter, isolated from the surface of baby spinach leaves. Based on the structure of this integron, we present a modified hypothesis for integron assembly, where the ancestral clinical class 1 integron was captured from a betaproteobacterial chromosome to form a Tn402-like transposon. This transposon then inserted into a plasmid-borne Tn21-like ancestor while in an environmental setting, possibly a bacterium resident in the phyllosphere. We suggest that the qacE gene cassette, conferring resistance to biocides, together with the mercury resistance operon carried by Tn21, provided a selective advantage when this bacterium made its way into the human commensal flora via food. The integron characterized here was located in Tn6007, which along with Tn6008, forms part of the larger Tn6006 transposon, itself inserted into another transposable element to form the Tn21-like transposon, Tn6005. This element has previously been described from the human microbiota, but with a promoter mutation that upregulates integron cassette expression. This element we describe here is from an environmental bacterium, and supports the hypothesis that the ancestral class 1 integron migrated into anthropogenic settings via foodstuffs. Selection pressures brought about by early antimicrobial agents, including mercury, arsenic and disinfectants, promoted its initial fixation, the acquisition of promoter mutations, and subsequent dissemination into various species and pathogens.

  11. Human pathogens in plant biofilms: Formation, physiology, and detection

    Science.gov (United States)

    Fresh produce, viewed as an essential part of a healthy life style is usually consumed in the form of raw or minimally processed fruits and vegetables, and is a potentially important source of food-borne human pathogenic bacteria and viruses. These are passed on to the consumer since the bacteria ca...

  12. Pathogenic potential of Listeria monocytogenes isolated from cattle ...

    African Journals Online (AJOL)

    Listeria monocytogenes is an opportunistic food-borne pathogen causing listeriosis especially among immune-compromised persons. Its high rate of morbidity and mortality has classed the organism among the top watch list in foods. It is known to produce several virulence factors which aid its survival in harsh conditions ...

  13. Methods for detecting pathogens in the beef food chain: an overview

    Science.gov (United States)

    The main food-borne pathogens of concern in the beef chain are Shiga toxin-producing Escherichia coli (STEC) and Salmonella. Other pathogens, including Listeria monocytogenes and Campylobacter spp. may also be present and pose contamination concerns in both the cattle production environment and bee...

  14. Food-Borne Outbreak Investigation and Molecular Typing: High Diversity of Staphylococcus aureus Strains and Importance of Toxin Detection

    Science.gov (United States)

    Denayer, Sarah; Nia, Yacine; Botteldoorn, Nadine

    2017-01-01

    Staphylococcus aureus is an important aetiological agent of food intoxications in the European Union as it can cause gastro-enteritis through the production of various staphylococcal enterotoxins (SEs) in foods. Reported enterotoxin dose levels causing food-borne illness are scarce and varying. Three food poisoning outbreaks due to enterotoxin-producing S. aureus strains which occurred in 2013 in Belgium are described. The outbreaks occurred in an elderly home, at a barbecue event and in a kindergarten and involved 28, 18, and six cases, respectively. Various food leftovers contained coagulase positive staphylococci (CPS). Low levels of staphylococcal enterotoxins ranging between 0.015 ng/g and 0.019 ng/g for enterotoxin A (SEA), and corresponding to 0.132 ng/g for SEC were quantified in the food leftovers for two of the reported outbreaks. Molecular typing of human and food isolates using pulsed-field gel electrophoresis (PFGE) and enterotoxin gene typing, confirmed the link between patients and the suspected foodstuffs. This also demonstrated the high diversity of CPS isolates both in the cases and in healthy persons carrying enterotoxin genes encoding emetic SEs for which no detection methods currently exist. For one outbreak, the investigation pointed out to the food handler who transmitted the outbreak strain to the food. Tools to improve staphylococcal food poisoning (SFP) investigations are presented. PMID:29261162

  15. In vitro screening of probiotic properties of Saccharomyces cerevisiae var. boulardii and food-borne Saccharomyces cerevisiae strains

    DEFF Research Database (Denmark)

    van der Aa Kuhle, Alis; Skovgaard, Kerstin; Jespersen, Lene

    2005-01-01

    The probiotic potential of IS Saccharomyces cerevisiae strains used for production of foods or bevel-ages or isolated from such, and eight strains of Saccharomyces cerevisiae var. boulardii, was investigated. All strains included were able to withstand pH 2.5 and 0.3% Ox-all. Adhesion to the nont......The probiotic potential of IS Saccharomyces cerevisiae strains used for production of foods or bevel-ages or isolated from such, and eight strains of Saccharomyces cerevisiae var. boulardii, was investigated. All strains included were able to withstand pH 2.5 and 0.3% Ox-all. Adhesion...... strain when the cells were pre- and coincubated with S. cerevisiae var. boulardii even though this yeast strain was low adhesive (5.4%), suggesting that adhesion is not a mandatory prerequisite for such a probiotic effect. A strain of S. cerevisiae isolated from West African sorghum beer exerted similar...... effects hence indicating that food-borne strains of S. cerevisiae may possess probiotic properties in spite of low adhesiveness. © 2004 Elsevier B.V. All rights reserved....

  16. An outbreak of food-borne salmonellosis linked to a bread takeaway shop in Ben Tre City, Vietnam.

    Science.gov (United States)

    Vo, Thuan Huu; Le, Ninh Hoang; Cao, Thuy Thanh Diem; Nuorti, J Pekka; Minh, Nguyen Nhu Tran

    2014-09-01

    To identify the vehicle, source, and causative agent of a community-wide food-borne outbreak of gastroenteritis. We conducted a case-control study. Cases were city residents diagnosed with gastroenteritis and hospitalized in Ben Tre City from 22 to 25 May 2013; 41 cases were selected randomly from a list of hospitalized patients. Controls were age- and gender-matched healthy neighbours of cases. Participants were interviewed using a standard questionnaire. Samples from patients and food were tested at reference laboratories. We used conditional logistic regression to calculate matched odds ratios (mORs) for the association of gastroenteritis with food items consumed. Of the 41 cases enrolled in the study, 61% were males and the median age was 33 years; cases resided in 12 wards of the City. Of 13 food items consumed by the cases, only stuffed bread was significantly associated with gastroenteritis (mOR 21.3, 95% confidence interval 6.3-71.8). Among the 29 cases who ate stuffed bread, the median time to illness onset was 9h. Patient stool samples and bread samples were positive for Salmonella species. Stuffed bread was the likely vehicle of the outbreak. The laboratory testing capacity for serotypes of Salmonella should be strengthened in Vietnam. Food-handler training in basic food safety measures should be improved. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Flies, fingers, fomites, and food. Campylobacteriosis in New Zealand--food-associated rather than food-borne.

    Science.gov (United States)

    Nelson, Warrick; Harris, Ben

    2006-08-18

    New Zealand has a very high rate of seasonal, sporadic campylobacteriosis compared to other OECD countries. Can the seasonality of New Zealand cases fit with an explanation of food-borne transmission (especially by chicken meat), and where does the fly-transmission hypothesis fit? Analysis of seasonal campylobacteriosis reports at the District Health Board level compared to regional ambient temperatures, and chicken consumption data. Literature review particularly of food-associated disease risks and transmission routes. Campylobacteriosis rates in New Zealand show a national annual increase at a rate similar to chicken consumption. A drastic reduction in chicken consumption was associated with significantly reduced campylobacteriosis cases in two European countries, further strengthening the link between disease risk and chicken consumption. However, serotype analysis of the Campylobacter isolates is ambiguous regarding chicken meat itself as the major source of infection. The seasonal colonisation pattern in live chickens follows the seasonal increase in human cases. Flies are a plausible vector, associated with increasing overwintered fly foraging activity, rather than a summer increase in fly numbers. The typically sporadic rather than outbreak nature of campylobacteriosis, the disjoint between seasonal patterns of human and chicken infection, the seasonal pattern itself, and inconclusive serotype evidence indicates against chicken meat itself as the major source of infection. However, chicken consumption is a significant risk factor.

  18. Food-Borne Outbreak Investigation and Molecular Typing: High Diversity of Staphylococcus aureus Strains and Importance of Toxin Detection.

    Science.gov (United States)

    Denayer, Sarah; Delbrassinne, Laurence; Nia, Yacine; Botteldoorn, Nadine

    2017-12-20

    Staphylococcus aureus is an important aetiological agent of food intoxications in the European Union as it can cause gastro-enteritis through the production of various staphylococcal enterotoxins (SEs) in foods. Reported enterotoxin dose levels causing food-borne illness are scarce and varying. Three food poisoning outbreaks due to enterotoxin-producing S. aureus strains which occurred in 2013 in Belgium are described. The outbreaks occurred in an elderly home, at a barbecue event and in a kindergarten and involved 28, 18, and six cases, respectively. Various food leftovers contained coagulase positive staphylococci (CPS). Low levels of staphylococcal enterotoxins ranging between 0.015 ng/g and 0.019 ng/g for enterotoxin A (SEA), and corresponding to 0.132 ng/g for SEC were quantified in the food leftovers for two of the reported outbreaks. Molecular typing of human and food isolates using pulsed-field gel electrophoresis (PFGE) and enterotoxin gene typing, confirmed the link between patients and the suspected foodstuffs. This also demonstrated the high diversity of CPS isolates both in the cases and in healthy persons carrying enterotoxin genes encoding emetic SEs for which no detection methods currently exist. For one outbreak, the investigation pointed out to the food handler who transmitted the outbreak strain to the food. Tools to improve staphylococcal food poisoning (SFP) investigations are presented.

  19. Food-Borne Outbreak Investigation and Molecular Typing: High Diversity of Staphylococcus aureus Strains and Importance of Toxin Detection

    Directory of Open Access Journals (Sweden)

    Sarah Denayer

    2017-12-01

    Full Text Available Staphylococcus aureus is an important aetiological agent of food intoxications in the European Union as it can cause gastro-enteritis through the production of various staphylococcal enterotoxins (SEs in foods. Reported enterotoxin dose levels causing food-borne illness are scarce and varying. Three food poisoning outbreaks due to enterotoxin-producing S. aureus strains which occurred in 2013 in Belgium are described. The outbreaks occurred in an elderly home, at a barbecue event and in a kindergarten and involved 28, 18, and six cases, respectively. Various food leftovers contained coagulase positive staphylococci (CPS. Low levels of staphylococcal enterotoxins ranging between 0.015 ng/g and 0.019 ng/g for enterotoxin A (SEA, and corresponding to 0.132 ng/g for SEC were quantified in the food leftovers for two of the reported outbreaks. Molecular typing of human and food isolates using pulsed-field gel electrophoresis (PFGE and enterotoxin gene typing, confirmed the link between patients and the suspected foodstuffs. This also demonstrated the high diversity of CPS isolates both in the cases and in healthy persons carrying enterotoxin genes encoding emetic SEs for which no detection methods currently exist. For one outbreak, the investigation pointed out to the food handler who transmitted the outbreak strain to the food. Tools to improve staphylococcal food poisoning (SFP investigations are presented.

  20. Analysis of acid-stressed Bacillus cereus reveals a major oxidative response and inactivation-associated radical formation

    NARCIS (Netherlands)

    Mols, J.M.; Kranenburg, van R.; Melis, van C.C.J.; Moezelaar, R.; Abee, T.

    2010-01-01

    Acid stress resistance of the food-borne human pathogen Bacillus cereus may contribute to its survival in acidic environments, such as encountered in soil, food and the human gastrointestinal tract. The acid stress responses of B. cereus strains ATCC 14579 and ATCC 10987 were analysed in aerobically

  1. A protein microarray for the rapid screening of patients suspected of infection with various food-borne helminthiases.

    Directory of Open Access Journals (Sweden)

    Jia-Xu Chen

    Full Text Available BACKGROUND: Food-borne helminthiases (FBHs have become increasingly important due to frequent occurrence and worldwide distribution. There is increasing demand for developing more sensitive, high-throughput techniques for the simultaneous detection of multiple parasitic diseases due to limitations in differential clinical diagnosis of FBHs with similar symptoms. These infections are difficult to diagnose correctly by conventional diagnostic approaches including serological approaches. METHODOLOGY/PRINCIPAL FINDINGS: In this study, antigens obtained from 5 parasite species, namely Cysticercus cellulosae, Angiostrongylus cantonensis, Paragonimus westermani, Trichinella spiralis and Spirometra sp., were semi-purified after immunoblotting. Sera from 365 human cases of helminthiasis and 80 healthy individuals were assayed with semi-purified antigens by both a protein microarray and the enzyme-linked immunosorbent assay (ELISA. The sensitivity, specificity and simplicity of each test for the end-user were evaluated. The specificity of the tests ranged from 97.0% (95% confidence interval (CI: 95.3-98.7% to 100.0% (95% CI: 100.0% in the protein microarray and from 97.7% (95% CI: 96.2-99.2% to 100.0% (95% CI: 100.0% in ELISA. The sensitivity varied from 85.7% (95% CI: 75.1-96.3% to 92.1% (95% CI: 83.5-100.0% in the protein microarray, while the corresponding values for ELISA were 82.0% (95% CI: 71.4-92.6% to 92.1% (95% CI: 83.5-100.0%. Furthermore, the Youden index spanned from 0.83 to 0.92 in the protein microarray and from 0.80 to 0.92 in ELISA. For each parasite, the Youden index from the protein microarray was often slightly higher than the one from ELISA even though the same antigen was used. CONCLUSIONS/SIGNIFICANCE: The protein microarray platform is a convenient, versatile, high-throughput method that can easily be adapted to massive FBH screening.

  2. Listeria monocytogenes infection in poultry and its public health importance with special reference to food borne zoonoses.

    Science.gov (United States)

    Dhama, Kuldeep; Verma, Amit Kumar; Rajagunalan, S; Kumar, Amit; Tiwari, Ruchi; Chakraborty, Sandip; Kumar, Rajesh

    2013-04-01

    Listeriosis is a disease that causes septicemia or encephalitis in humans, animals and birds. Although, the disease is rare and sporadic in poultry but if occurs then causes septicemia or sometimes localized encephalitis. Occasionally, the disease is seen in young chicks and the causative agent, like in humans and animals, is Listeria monocytogenes. The organism is capable to infect almost all animals and poultry; however, outbreaks of listeriosis are infrequent in birds. It is widely distributed among avian species and chickens, turkeys, waterfowl (geese, ducks), game birds, pigeons, parrots, wood grouse, snowy owl, eagle, canaries, which appear to be the most commonly affected. Chickens are thought to be the carriers of Listeria and also the prime reservoirs for the infection and thus contaminate the litter and environment of the poultry production units. Listeriosis is often noticed along with other poultry diseases such as coccidiosis, infectious coryza, salmonellosis, campylobacteriosis and parasitic infections, signifying the opportunistic nature of the organism. Intestinal colonization of poultry and the presence of L. monocytogenes in feces represent a potential source of the organism for listeriosis in ruminants. Man gets infection from raw broiler meat due to Listeria contamination and unhygienic conditions of the processing area, rather than acquiring direct infection from birds. With the changing food habits of the people, the health consciousness is also increasing and since listeriosis has now been recognized as an emerging food borne zoonoses. Therefore, this review has been compiled to make aware the poultry producers and the consumers of poultry meat/products regarding the importance of the disease and its public health significance.

  3. Surveillance of acute infectious gastroenteritis (1992-2009) and food-borne disease outbreaks (1996-2009) in Italy, with a focus on the Piedmont and Lombardy regions.

    Science.gov (United States)

    Mughini-Gras, L; Graziani, C; Biorci, F; Pavan, A; Magliola, R; Ricci, A; Gilli, G; Carraro, E; Busani, L

    2012-02-23

    We describe trends in the occurrence of acute infectious gastroenteritis (1992 to 2009) and food-borne disease outbreaks (1996 to 2009) in Italy. In 2002, the Piedmont region implemented a surveillance system for early detection and control of food-borne disease outbreaks; in 2004, the Lombardy region implemented a system for surveillance of all notifiable human infectious diseases. Both systems are internet based. We compared the regional figures with the national mean using official notification data provided by the National Infectious Diseases Notification System (SIMI) and the National Institute of Statistics (ISTAT), in order to provide additional information about the epidemiology of these diseases in Italy. When compared with the national mean, data from the two regional systems showed a significant increase in notification rates of non-typhoid salmonellosis and infectious diarrhea other than non-typhoid salmonellosis, but for foodborne disease outbreaks, the increase was not statistically significant. Although the two regional systems have different objectives and structures, they showed improved sensitivity regarding notification of cases of acute infectious gastroenteritis and, to a lesser extent, food-borne disease outbreaks, and thus provide a more complete picture of the epidemiology of these diseases in Italy.

  4. Thrombin generation, ProC(®)Global, prothrombin time and activated partial thromboplastin time in thawed plasma stored for seven days and after methylene blue/light pathogen inactivation.

    Science.gov (United States)

    Thiele, Thomas; Hron, Gregor; Kellner, Sarah; Wasner, Christina; Westphal, Antje; Warkentin, Theodore E; Greinacher, Andreas; Selleng, Kathleen

    2016-01-01

    Methylene blue pathogen inactivation and storage of thawed plasma both lead to changes in the activity of several clotting factors. We investigated how this translates into a global loss of thrombin generation potential and alterations in the protein C pathway. Fifty apheresis plasma samples were thawed and each divided into three subunits. One subunit was stored for 7 days at 4 °C, one was stored for 7 days at 22 °C and one was stored at 4 °C after methylene blue/light treatment. Thrombin generation parameters, ProC(®)Global-NR, prothrombin time and activated partial thromboplastin time were assessed on days 0 and 7. The velocity of thrombin generation increased significantly after methylene blue treatment (increased thrombin generation rate; time to peak decreased) and decreased after storage (decreased thrombin generation rate and peak thrombin; increased lag time and time to peak). The endogenous thrombin generation potential remained stable after methylene blue treatment and storage at 4 °C. Methylene blue treatment and 7 days of storage at 4 °C activated the protein C pathway, whereas storage at room temperature and storage after methylene blue treatment decreased the functional capacity of the protein C pathway. Prothrombin time and activated partial thromboplastin time showed only modest alterations. The global clotting capacity of thawed plasma is maintained at 4 °C for 7 days and directly after methylene blue treatment of thawed plasma. Thrombin generation and ProC(®)Global are useful tools for investigating the impact of pathogen inactivation and storage on the clotting capacity of therapeutic plasma preparations.

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

    Science.gov (United States)

    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 marketi...

  6. 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...

  7. Efficacy of inactivated influenza vaccines for protection of poultry against the H7N9 low pathogenic avian influenza virus isolated in China during 2013

    Science.gov (United States)

    The recent outbreak in China of avian influenza (AI) H7N9 in birds and humans underscores the interspecies movement of these viruses. Interestingly, the genetic composition of these H7N9 viruses appears to be solely of avian origin and of low pathogenicity in birds. Although few isolations of these ...

  8. Protection against H7N3 high pathogenicity avian influenza in chickens immunized with a recombinant fowlpox and an inactivated avian influenza vaccines

    Science.gov (United States)

    Beginning on June 2012, an H7N3 highly pathogenic avian influenza (HPAI) epizootic was reported in the State of Jalisco (Mexico), with some 22.4 million chickens that died, were slaughtered on affected farms or were preemptively culled on neighboring farms. In the current study, layer chickens were ...

  9. Protection of poultry against the 2012 Mexican H7N3 highly pathogenic avian influenza virus with inactivated H7 avian influenza vaccines

    Science.gov (United States)

    In June of 2012, an outbreak of highly pathogenic avian influenza (HPAI) H7N3 was reported poultry in Jalisco, Mexico. Since that time the virus has spread to the surrounding States of Guanajuato and Aguascalientes and new outbreaks continue to be reported. To date more than 25 million birds have di...

  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, B.P.H.; Tonnis, W.F.; Murugappan, S.; Rottier, P.; Koch, G.; Frijlink, H.W.; Huckriede, A.; Hinrichs, W.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. Description of Clean and Healthy Behavior of Food Borne Disease Among by School Children Age in Babat Jerawat I Elementary School, District Pakal Surabaya

    Directory of Open Access Journals (Sweden)

    Hidayat Heny Sholikhah

    2014-08-01

    Full Text Available Background: Incidence of food borne disease, such as diarrhea, typhoid and hookworm infection in school childrenwere still sufficient susceptible. Lack of clean and healthy behavior became primary cause, so that the agent can easilyenter to the body through the food consumed. The purpose of this study was to descript the clean and healthy behaviors by school children age at Babat Jerawat I Elementary School, District Pakal Surabaya. Methods: This study was a crosssectional study. The sample of this study were 112 of fifth grade students at Babat Jerawat I Elementary school, District Pakal Surabaya, selected by purposive sampling of 121 students who met the inclusion criteria. Data of clean and healthy behavior were collected by observation and interviews focused on a group of school children using questionnaires, checklists and interview guides. Data analysis was done by using descriptive analysis. Results: The results showed that the clean and healthy behaviors about food borne disease, the majority of school children in Elementary school Babat Jerawat I District Pakal Surabaya included in good criteria (51.8% and small portion of these included less category (48.2%. Conclusion:Clean and Healthy Behavior of food borne disease in school children age had good criteria, but still need attention formany factors that influence it, such as the availability of facilities, affordability snacks outside of school and examples ofunhealthy behaviors in family environment. Recommendation: Improve the cooperation between the school and localhealth officials to tighten rules on the management of snack vending around schools, and do continuous education both within the school and the child’s school community.

  12. Flexible thin-layer dielectric barrier discharge plasma treatment of pork butt and beef loin: effects on pathogen inactivation and meat-quality attributes.

    Science.gov (United States)

    Jayasena, Dinesh D; Kim, Hyun Joo; Yong, Hae In; Park, Sanghoo; Kim, Kijung; Choe, Wonho; Jo, Cheorun

    2015-04-01

    The effects of a flexible thin-layer dielectric barrier discharge (DBD) plasma system using a sealed package on microbial inactivation and quality attributes of fresh pork and beef were tested. Following a 10-min treatment, the microbial-load reductions of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium were 2.04, 2.54, and 2.68 Log CFU/g in pork-butt samples and 1.90, 2.57, and 2.58 Log CFU/g in beef-loin samples, respectively. Colorimetric analysis showed that DBD-plasma treatment did not significantly affect L* values (lightness) of pork and beef samples, but lowered a* values (redness) significantly after 5- and 7.5-min exposures. The plasma treatment significantly influenced lipid oxidation only after a 10-min exposure. The texture of both types of meat was unaffected by plasma treatment. All sensory parameters of treated and non-treated samples were comparable except for taste, which was negatively influenced by the plasma treatment (P quality might be prevented by the use of hurdle technology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Prospects of eliminating pathogens by the process of food irradiation

    International Nuclear Information System (INIS)

    Kampelmacher, E.H.

    1981-01-01

    Food-borne diseases are an increasing health hazard throughout the world. Some of these diseases, such as salmonellosis, staphylo-entero-toxicosis, botulism, vibriosis and parasitic infections have always played an important role, whereas some other food-borne pathogens, such as Campylobacter, Vibrio parahaemolyticus and toxin-producing fungi have only been recognised in recent decades. Changing food-production methods, food processing and especially food habits, together with the enormous trade in foods and feeds from one part of the world to the other, are responsible for the increase of these diseases. To meet this situation, prevention and control of food-borne diseases, which involve large groups of persons and play a major socio-economic role in many parts of the world, are of utmost importance. In prevention and control programmes food irradiation can be applied successfully and may solve some of the food and feed contamination problems. The author summarizes to-day's most important food-borne diseases, the type of foods which are responsible for infections in man and animals, and the commodities in which low-dose food irradiation may be of great value in preventing these diseases. The advantages of irradiation versus the use of chemical additives and pesticides and with respect to the prevention of cross-contamination (which plays a very important role in initiating food-borne diseases) by pre-packaging, are emphasized. The required irradiaton doses to eliminate or reduce the number of pathogenic organisms which may be present in foods, the problem of radioresistance and the acceptability of irradiated food are discussed. Finally to-day's situation of irradiated foods with regard to legislation, consumers' information and economic feasibility is summarized. (author)

  14. 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

  15. 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.

  16. Lactase persistence and augmented salivary alpha-amylase gene copy numbers might have been selected by the combined toxic effects of gluten and (food born) pathogens

    NARCIS (Netherlands)

    Pruimboom, Leo; Fox, Tom; Muskiet, Frits A. J.

    Various positively selected adaptations to new nutrients have been identified. Lactase persistence is among the best known, conferring the ability for drinking milk at post weaning age. An augmented number of amylase gene (AMY1) copies, giving rise to higher salivary amylase activity, has been

  17. An Engineered R-Type Pyocin Is a Highly Specific and Sensitive Bactericidal Agent for the Food-Borne Pathogen Escherichia coli O157:H7

    Science.gov (United States)

    Some strains of Pseudomonas aeruginosa produce R-type pyocins, which are high molecular weight phage tail-like protein complexes that have bactericidal activity against other Pseudomonas strains. These particles recognize and bind to bacterial surface structures via tail fibers; their primary spectr...

  18. Development of a novel approach for the production of dried genomic DNA for use as standards for qualitative PCR testing of food-borne pathogens

    DEFF Research Database (Denmark)

    Trapmann, S.; Catalani, P.; Hoorfar, Jeffrey

    2004-01-01

    As part of a multi-centre European project, FOOD-PCR, the feasibility of a novel approach for production of dried bacterial DNA that could be used as certified reference materials (CRM) was assessed. Selected strains of Salmonella typhimurium, Listeria monocytogenes, Escherichia coli O157...

  19. Chemical composition and antioxidative activity of Echinophora platyloba DC. essential oil, and its interaction with natural antimicrobials against food-borne pathogens and spoilage organisms.

    Science.gov (United States)

    Saei-Dehkordi, S Siavash; Fallah, Aziz A; Saei-Dehkordi, S Saeid; Kousha, Sanaz

    2012-11-01

    This study was undertaken to determine the chemical composition and antioxidative capacity of Echinophora platyloba DC. essential oil, and its antimicrobial potency against Listeria monocytogenes, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli O157:H7, Pseudomonas aeruginosa, Candida albicans, Candida tropicalis, Rhodotorula rubra, and Rhodotorula mucilaginosa. The essential oil was analyzed by GC and GC-MS; and evaluated for its antioxidative and antimicrobial (singly or in combination with chitosan, nisin, monolaurin, or amphotericin B) activity. Thirty-three components were characterized representing 95.69% of the total oil composition in which thymol, trans-ocimene, carvacrol, and (E)-sesqui-lavandulol were the major constituents. The oil exhibited high scavenging (IC(50): 49.7 ± 2.3 μg/mL) and relative antioxidative activity (RAA%: 85.21 ± 0.4) in 1,1-diphenyl-2-picrylhydrazyl radicals and β-carotene/linoleic acid bleaching assays, respectively. The oil showed antimicrobial activity against L. monocytogenes, B. cereus, B. subtilis, S. aureus, S. typhimurium, E. coli O157:H7, P. aeruginosa, C. albicans, C. tropicalis, R. Rubra, and R. mucilaginosa. Moreover, R. mucilaginosa and P. aeruginosa were the most susceptible and most resistant organisms, respectively. Regarding the checkerboard data, 47 fractional inhibitory concentration index (FICIs) (≤ 0.5) indicated synergistic, whereas 7 FICIs (>0.5 to 1) indicated additive effect. Consequently, E. platyloba DC. essential oil could be used as a recommended natural antioxidant and antimicrobial substance for food preservation. © 2012 Institute of Food Technologists®

  20. In vitro study on the composition and antibacterial effects of aqueous and methanol extracts of on some of food-borne pathogens

    Directory of Open Access Journals (Sweden)

    A. Barati

    2016-08-01

    Full Text Available Scrophularia khorassanica belongs to the Scrophulariaceae family that geographically grows wild only in Iran-Khorasan. There is insufficient information about its composition and antibacterial activity. Due to the application of S. khorassanica and related species in traditional medicine, the aim of this study was to determine antimicrobial effect of S. khorassanica aqueous and methanolic extracts on the growth of Escherichia coli and Staphylococcus aureus and also to determine the composition of the essential oil in-vitro. Extracts and the essential oil were prepared respectively by maceration and hydro-distillation methods. The composition of the essential oil examined by GC/MS and the minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC determined by broth micro-dilution assay. Composition analysis identified a total of 28 various components in which the main components were 1,3-Bis (trimethylsilyl, benzene (34.93%, р-Cymene (12.55%, Palmitic acid (6.79, Thymol (6.22%, Linalool (4.59%, 2-undecanone(4.35%, Sorbitol(1.87%, Carvacrol (1.74%, γ-Terpinene (1.06%, β -Elemene (1.03% and α-Pinene (0.3%. The MIC for methanolic extract against E. coli and S. aureus was 12.5 and 25 mg/ml, respectively. In the case of aqueous extract, it was estimated at 6.25 and 12.5 mg/ml, respectively. Based on these results, the aqueous extract had the strongest antibacterial effect. It was concluded that Scrophularia khorassanica extract can be used as an natural preservative.

  1. Inactivation of pathogenic viruses by plant-derived tannins: strong effects of extracts from persimmon (Diospyros kaki on a broad range of viruses.

    Directory of Open Access Journals (Sweden)

    Kyoko Ueda

    Full Text Available Tannins, plant-derived polyphenols and other related compounds, have been utilized for a long time in many fields such as the food industry and manufacturing. In this study, we investigated the anti-viral effects of tannins on 12 different viruses including both enveloped viruses (influenza virus H3N2, H5N3, herpes simplex virus-1, vesicular stomatitis virus, Sendai virus and Newcastle disease virus and non-enveloped viruses (poliovirus, coxsachievirus, adenovirus, rotavirus, feline calicivirus and mouse norovirus. We found that extracts from persimmon (Diospyros kaki, which contains ca. 22% of persimmon tannin, reduced viral infectivity in more than 4-log scale against all of the viruses tested, showing strong anti-viral effects against a broad range of viruses. Other tannins derived from green tea, acacia and gallnuts were effective for some of the viruses, while the coffee extracts were not effective for any of the virus. We then investigated the mechanism of the anti-viral effects of persimmon extracts by using mainly influenza virus. Persimmon extracts were effective within 30 seconds at a concentration of 0.25% and inhibited attachment of the virus to cells. Pretreatment of cells with the persimmon extracts before virus infection or post-treatment after virus infection did not inhibit virus replication. Protein aggregation seems to be a fundamental mechanism underlying the anti-viral effect of persimmon tannin, since viral proteins formed aggregates when purified virions were treated with the persimmon extracts and since the anti-viral effect was competitively inhibited by a non-specific protein, bovine serum albumin. Considering that persimmon tannin is a food supplement, it has a potential to be utilized as a safe and highly effective anti-viral reagent against pathogenic viruses.

  2. 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

  3. Risk-analysis of human pathogen spread in the vegetable industry: a comparison between organic and conventional production chains

    NARCIS (Netherlands)

    Franz, E.; Bruggen, van A.H.C.; Semenov, A.M.

    2004-01-01

    An overview is given of recent problems with food-borne enteric human pathogens originating from contaminated agricultural animals. The need for risk analysis is indicated, and the generally accepted procedure for risk assessment is outlined. Two main approaches to probability and risk calculations,

  4. Differences in pathogen colonization and mortality of genetically selected Japanese quail lines subjected to heat stress and Escherichia coli challenge

    Science.gov (United States)

    Japanese quail selected for divergent corticosterone response to restraint stress were evaluated for their resistance to heat stress and aerosol challenge with avian pathogenic Escherichia coli (APEC) to determine the impact of stress response on APEC pathogenesis and colonization with food-borne pa...

  5. Stress responses in pathogenic Yersinia enterocolitica with reference to the stability of the virulence plasmid in food

    Science.gov (United States)

    Yersinia enterocolitica has been associated with food-borne illness, most often due the ingestion of pork products. The pathogenic effects induced by a Y. enterocolitica infection are caused by the interplay of chromosomal genes and a virulence plasmid, pYV. Generally, the plasmid is lost during g...

  6. Investigation of a food-borne outbreak of gastroenteritis in a school canteen revealed a variant of sapovirus genogroup V not detected by standard PCR, Sollentuna, Sweden, 2016.

    Science.gov (United States)

    Hergens, Maria-Pia; Nederby Öhd, Joanna; Alm, Erik; Askling, Helena H; Helgesson, Sofia; Insulander, Mona; Lagerqvist, Nina; Svenungsson, Bo; Tihane, Malin; Tolfvenstam, Thomas; Follin, Per

    2017-06-01

    A food-borne outbreak of gastroenteritis with more than 650 suspected cases occurred in April 2016 in Sollentuna, Sweden. It originated in a school kitchen serving a total of 2,700 meals daily. Initial microbiological testing (for Campylobacter, Salmonella, Shigella, Yersinia, Giardia, Cryptosporidium, Entamoeba histolytica, adeno-, astro-, noro-, rota- and sapovirus) of stool samples from 15 symptomatic cases was negative, despite a clinical presentation suggestive of calicivirus. Analyses of the findings from both the Sollentuna municipality environmental team and a web-based questionnaire suggested that the source of the outbreak was the salad buffet served on 20 April, although no specific food item could be identified. Subsequent electron microscopic examination of stool samples followed by whole genome sequencing revealed a variant of sapovirus genogroup V. The virus was not detected using standard PCR screening. This paper describes the epidemiological outbreak investigation and findings leading to the discovery. This article is copyright of The Authors, 2017.

  7. Ecophysiological characterization of common food-borne fungi in relation to pH and water activity under various atmospheric compositions

    DEFF Research Database (Denmark)

    Haasum, Iben; Nielsen, Per Væggemose

    1998-01-01

    The combined effect of pH, water activity (aw), oxygen (O2) and carbon dioxide (CO2) levels on growth and sporulation of 10 common food-borne fungi were studied. The use of a multivariate statistical method (PLS) for the analysis of data showed, that the fungi could be grouped according...... to their physiological response to changes in the four tested factors. CO2, aw and pH were found to be the most significant factors describing differences and similarities among the fungi. Maximal inhibitory effect of elevated levels of CO2 (5-25%) and decreased aw (0.99-0.95) varied among the 10 species from 6 to 77...

  8. Investigation of a food-borne outbreak of gastroenteritis in a school canteen revealed a variant of sapovirus genogroup V not detected by standard PCR, Sollentuna, Sweden, 2016

    Science.gov (United States)

    Hergens, Maria-Pia; Nederby Öhd, Joanna; Alm, Erik; Askling, Helena H; Helgesson, Sofia; Insulander, Mona; Lagerqvist, Nina; Svenungsson, Bo; Tihane, Malin; Tolfvenstam, Thomas; Follin, Per

    2017-01-01

    A food-borne outbreak of gastroenteritis with more than 650 suspected cases occurred in April 2016 in Sollentuna, Sweden. It originated in a school kitchen serving a total of 2,700 meals daily. Initial microbiological testing (for Campylobacter, Salmonella, Shigella, Yersinia, Giardia, Cryptosporidium, Entamoeba histolytica, adeno-, astro-, noro-, rota- and sapovirus) of stool samples from 15 symptomatic cases was negative, despite a clinical presentation suggestive of calicivirus. Analyses of the findings from both the Sollentuna municipality environmental team and a web-based questionnaire suggested that the source of the outbreak was the salad buffet served on 20 April, although no specific food item could be identified. Subsequent electron microscopic examination of stool samples followed by whole genome sequencing revealed a variant of sapovirus genogroup V. The virus was not detected using standard PCR screening. This paper describes the epidemiological outbreak investigation and findings leading to the discovery. PMID:28602163

  9. Enrichment followed by quantitative PCR both for rapid detection and as a tool for quantitative risk assessment of food-borne thermotolerant campylobacters

    DEFF Research Database (Denmark)

    Josefsen, Mathilde Hartmann; Jacobsen, N. R.; Hoorfar, Jeffrey

    2004-01-01

    As part of a large international project for standardization of PCR (Food-PCR; www.pcr.dk), a multiplex, multiplatform, ready-to-go enrichment followed by a real-time PCR method, including an internal amplification control, was developed for detection of food-borne thermotolerant campylobacters...... Organization (ISO)-based culture method by testing low, medium, and high levels of 12 spiked and 66 unspiked, presumably naturally contaminated, chicken rinse samples. In the RotorGene, a positive PCR response was detected in 40 samples of the 66. This was in complete agreement with the enriched ISO culture...... naturally contaminated chicken samples, which indicates PCR's additional potential as a tool for quantitative risk assessment. Signal from the internal amplification control was detected in all culture-negative samples (VIC Ct: 23.1 to 28.1). The method will be taken further and validated...

  10. 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....

  11. Development of simple multiplex real-time PCR assays for foodborne pathogens detection and identification on LightCycler

    Directory of Open Access Journals (Sweden)

    Avo Karus1

    2017-03-01

    Full Text Available Most acute intestinal diseases are caused by food-borne pathogens. A fast and simple real-time PCR-based procedure for simultaneous detection of food contamination by any of the five food-borne pathogens: Campylobacter jejuni, Mycobacterium bovis, Enterobacter sakazaki, Shigella boydii, Clostridium perfrigens using multiplex EvaGreen real-time PCR for LightCycler was developed and evaluated. Real-time qPCR showed excellent sensitivity. Tm calling and Melting Curve Genotyping (MCG were used for analysis of PCR product melting curves. The Melting Curve Genotyping option showed good performance for discrimination of positive samples containing DNA of single pathogen or pathogen mixtures from negative samples.

  12. Increased cytotoxicity of food-borne mycotoxins toward human cell lines in vitro via enhanced cytochrome p450 expression using the MTT bioassay.

    Science.gov (United States)

    Lewis, C W; Smith, J E; Anderson, J G; Freshney, R I

    1999-11-01

    Eight food-borne mycotoxins epidemiologically implicated in human disease were tested for their cytotoxic effects on human cells previously immortalised and transfected to introduce human cytochrome p450 (CYP 450) genes. Such cells retain many characteristics of normal cell growth and differentiation while simultaneously having the potential of either increasing or decreasing the metabolic activity (cytotoxicity) of the challenging mycotoxins. The MTT assay provided an indication of cytotoxicity. Of the nine CYP450s introduced CYP1A2 was most effective, rendering the cells 540 times more sensitive than the control cells to aflatoxin B1, 28 times more sensitive to aflatoxin G1 and 8-fold more sensitive to ochratoxin A. CYP3A4 resulted in the cells being 211 times more toxic to aflatoxin B1 and 8-fold more toxic to aflatoxin G1 while CYP 2A6, CYP 3A5 and CYP 2E1 also produced observable effects. No increase in metabolic activity was found using cyclopiazonic acid, deoxynivalenol, fumonisin B1, patulin or T-2 toxin. CD5Os were calculated for the mycotoxins against the non-CYP-introduced control cells. There was almost a five order of magnitude difference between the most toxic, T-2 toxin (CD50 0.0057 microgram/ml) and the least toxic, fumonisin B1 (CD50 476.2 micrograms/ml). In vitro biological assays thus provide an excellent system for quantifying the often low CD50s expressed by mycotoxins in foods.

  13. FoodChain-Lab: A Trace-Back and Trace-Forward Tool Developed and Applied during Food-Borne Disease Outbreak Investigations in Germany and Europe.

    Science.gov (United States)

    Weiser, Armin A; Thöns, Christian; Filter, Matthias; Falenski, Alexander; Appel, Bernd; Käsbohrer, Annemarie

    2016-01-01

    FoodChain-Lab is modular open-source software for trace-back and trace-forward analysis in food-borne disease outbreak investigations. Development of FoodChain-Lab has been driven by a need for appropriate software in several food-related outbreaks in Germany since 2011. The software allows integrated data management, data linkage, enrichment and visualization as well as interactive supply chain analyses. Identification of possible outbreak sources or vehicles is facilitated by calculation of tracing scores for food-handling stations (companies or persons) and food products under investigation. The software also supports consideration of station-specific cross-contamination, analysis of geographical relationships, and topological clustering of the tracing network structure. FoodChain-Lab has been applied successfully in previous outbreak investigations, for example during the 2011 EHEC outbreak and the 2013/14 European hepatitis A outbreak. The software is most useful in complex, multi-area outbreak investigations where epidemiological evidence may be insufficient to discriminate between multiple implicated food products. The automated analysis and visualization components would be of greater value if trading information on food ingredients and compound products was more easily available.

  14. FoodChain-Lab: A Trace-Back and Trace-Forward Tool Developed and Applied during Food-Borne Disease Outbreak Investigations in Germany and Europe.

    Directory of Open Access Journals (Sweden)

    Armin A Weiser

    Full Text Available FoodChain-Lab is modular open-source software for trace-back and trace-forward analysis in food-borne disease outbreak investigations. Development of FoodChain-Lab has been driven by a need for appropriate software in several food-related outbreaks in Germany since 2011. The software allows integrated data management, data linkage, enrichment and visualization as well as interactive supply chain analyses. Identification of possible outbreak sources or vehicles is facilitated by calculation of tracing scores for food-handling stations (companies or persons and food products under investigation. The software also supports consideration of station-specific cross-contamination, analysis of geographical relationships, and topological clustering of the tracing network structure. FoodChain-Lab has been applied successfully in previous outbreak investigations, for example during the 2011 EHEC outbreak and the 2013/14 European hepatitis A outbreak. The software is most useful in complex, multi-area outbreak investigations where epidemiological evidence may be insufficient to discriminate between multiple implicated food products. The automated analysis and visualization components would be of greater value if trading information on food ingredients and compound products was more easily available.

  15. Dynamic sporulation gene co-expression networks for Bacillus subtilis 168 and the food-borne isolate Bacillus amyloliquefaciens: a transcriptomic model.

    Science.gov (United States)

    Omony, Jimmy; de Jong, Anne; Krawczyk, Antonina O; Eijlander, Robyn T; Kuipers, Oscar P

    2018-02-09

    Sporulation is a survival strategy, adapted by bacterial cells in response to harsh environmental adversities. The adaptation potential differs between strains and the variations may arise from differences in gene regulation. Gene networks are a valuable way of studying such regulation processes and establishing associations between genes. We reconstructed and compared sporulation gene co-expression networks (GCNs) of the model laboratory strain Bacillus subtilis 168 and the food-borne industrial isolate Bacillus amyloliquefaciens. Transcriptome data obtained from samples of six stages during the sporulation process were used for network inference. Subsequently, a gene set enrichment analysis was performed to compare the reconstructed GCNs of B. subtilis 168 and B. amyloliquefaciens with respect to biological functions, which showed the enriched modules with coherent functional groups associated with sporulation. On basis of the GCNs and time-evolution of differentially expressed genes, we could identify novel candidate genes strongly associated with sporulation in B. subtilis 168 and B. amyloliquefaciens. The GCNs offer a framework for exploring transcription factors, their targets, and co-expressed genes during sporulation. Furthermore, the methodology described here can conveniently be applied to other species or biological processes.

  16. 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

  17. Combining Lactic Acid Spray with Near-Infrared Radiation Heating To Inactivate Salmonella enterica Serovar Enteritidis on Almond and Pine Nut Kernels.

    Science.gov (United States)

    Ha, Jae-Won; Kang, Dong-Hyun

    2015-07-01

    The aim of this study was to investigate the efficacy of near-infrared radiation (NIR) heating combined with lactic acid (LA) sprays for inactivating Salmonella enterica serovar Enteritidis on almond and pine nut kernels and to elucidate the mechanisms of the lethal effect of the NIR-LA combined treatment. Also, the effect of the combination treatment on product quality was determined. Separately prepared S. Enteritidis phage type (PT) 30 and non-PT 30 S. Enteritidis cocktails were inoculated onto almond and pine nut kernels, respectively, followed by treatments with NIR or 2% LA spray alone, NIR with distilled water spray (NIR-DW), and NIR with 2% LA spray (NIR-LA). Although surface temperatures of nuts treated with NIR were higher than those subjected to NIR-DW or NIR-LA treatment, more S. Enteritidis survived after NIR treatment alone. The effectiveness of NIR-DW and NIR-LA was similar, but significantly more sublethally injured cells were recovered from NIR-DW-treated samples. We confirmed that the enhanced bactericidal effect of the NIR-LA combination may not be attributable to cell membrane damage per se. NIR heat treatment might allow S. Enteritidis cells to become permeable to applied LA solution. The NIR-LA treatment (5 min) did not significantly (P > 0.05) cause changes in the lipid peroxidation parameters, total phenolic contents, color values, moisture contents, and sensory attributes of nut kernels. Given the results of the present study, NIR-LA treatment may be a potential intervention for controlling food-borne pathogens on nut kernel products. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  18. An integrated QSAR-PBK/D modelling approach for predicting detoxification and DNA adduct formation of 18 acyclic food-borne α,β-unsaturated aldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Kiwamoto, R., E-mail: reiko.kiwamoto@wur.nl; Spenkelink, A.; Rietjens, I.M.C.M.; Punt, A.

    2015-01-01

    Acyclic α,β-unsaturated aldehydes present in food raise a concern because the α,β-unsaturated aldehyde moiety is considered a structural alert for genotoxicity. However, controversy remains on whether in vivo at realistic dietary exposure DNA adduct formation is significant. The aim of the present study was to develop physiologically based kinetic/dynamic (PBK/D) models to examine dose-dependent detoxification and DNA adduct formation of a group of 18 food-borne acyclic α,β-unsaturated aldehydes without 2- or 3-alkylation, and with no more than one conjugated double bond. Parameters for the PBK/D models were obtained using quantitative structure–activity relationships (QSARs) defined with a training set of six selected aldehydes. Using the QSARs, PBK/D models for the other 12 aldehydes were defined. Results revealed that DNA adduct formation in the liver increases with decreasing bulkiness of the molecule especially due to less efficient detoxification. 2-Propenal (acrolein) was identified to induce the highest DNA adduct levels. At realistic dietary intake, the predicted DNA adduct levels for all aldehydes were two orders of magnitude lower than endogenous background levels observed in disease free human liver, suggesting that for all 18 aldehydes DNA adduct formation is negligible at the relevant levels of dietary intake. The present study provides a proof of principle for the use of QSAR-based PBK/D modelling to facilitate group evaluations and read-across in risk assessment. - Highlights: • Physiologically based in silico models were made for 18 α,β-unsaturated aldehydes. • Kinetic parameters were determined by in vitro incubations and a QSAR approach. • DNA adduct formation was negligible at levels relevant for dietary intake. • The use of QSAR-based PBK/D modelling facilitates group evaluations and read-across.

  19. Food-borne outbreaks, distributions, virulence, and antibiotic resistance profiles of Vibrio parahaemolyticus in Korea from 2003 to 2016: a review

    Directory of Open Access Journals (Sweden)

    Kunbawui Park

    2018-02-01

    Full Text Available Abstract Background Vibrio parahaemolyticus is one of the most common causes of seafood-borne illnesses in Korea, either directly or indirectly, by consuming infected seafood. Many studies have demonstrated the antibiotic susceptibility profile of V. parahaemolyticus. This strain has developed multiple antibiotic resistance, which has raised serious public health and economic concerns. This article reviews the food-borne outbreaks, distributions, virulence, and antibiotic resistance profiles of V. parahaemolyticus in Korea during 2003–2016. Main body V. parahaemolyticus infections appeared to be seasonally dependent, because 69.7% of patient infections occurred in both August and September during 2003–2016. In addition, the occurrence of V. parahaemolyticus in marine environments varies seasonally but is particularly high in July, August, and September. V. parahaemolyticus isolated from aquaculture sources on the Korean coast varied in association with virulence genes, some did not possess either the tdh (thermostable direct hemolysin or trh (tdh-related hemolysin genes, and a few were positive for only the trh gene or both genes. The high percentage of ampicillin resistance against V. parahaemolyticus in the aquatic environment suggests that ampicillin cannot be used to effectively treat infections caused by this organism. Short conclusion This study shows that the observed high percentage of multiple antibiotic resistance to V. parahaemolyticus is due to conventionally used antibiotics. Therefore, monitoring the antimicrobial resistance patterns at a national level and other solutions are needed to control aquaculture infections, ensure seafood safety, and avoid threats to public health caused by massive misuse of antibiotics.

  20. Egg white versus Salmonella Enteritidis! A harsh medium meets a resilient pathogen

    OpenAIRE

    Baron, Florence; Nau, Françoise; Guérin-Dubiard, Catherine; Bonnassie, Sylvie; Gautier, Michel; Andrews, Simon C.; Jan, Sophie

    2016-01-01

    Salmonella enterica serovar Enteritidis is the prevalent egg-product-related food-borne pathogen. The egg-contamination capacity of S. Enteritidis includes its exceptional survival capability within the harsh conditions provided by egg white. Egg white proteins, such as lysozyme and ovotransferrin, are well known to play important roles in defence against bacterial invaders. Indeed, several additional minor proteins and peptides have recently been found to play known or potential roles in pro...

  1. Inactivation Strategies for Clostridium perfringens Spores and Vegetative Cells.

    Science.gov (United States)

    Talukdar, Prabhat K; Udompijitkul, Pathima; Hossain, Ashfaque; Sarker, Mahfuzur R

    2017-01-01

    Clostridium perfringens is an important pathogen to human and animals and causes a wide array of diseases, including histotoxic and gastrointestinal illnesses. C. perfringens spores are crucial in terms of the pathogenicity of this bacterium because they can survive in a dormant state in the environment and return to being live bacteria when they come in contact with nutrients in food or the human body. Although the strategies to inactivate C. perfringens vegetative cells are effective, the inactivation of C. perfringens spores is still a great challenge. A number of studies have been conducted in the past decade or so toward developing efficient inactivation strategies for C. perfringens spores and vegetative cells, which include physical approaches and the use of chemical preservatives and naturally derived antimicrobial agents. In this review, different inactivation strategies applied to control C. perfringens cells and spores are summarized, and the potential limitations and challenges of these strategies are discussed. Copyright © 2016 American Society for Microbiology.

  2. 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

  3. 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

  4. 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.

  5. 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...... electrolytic-Fenton cell) with the aim to broad the application of microbial electrochemistry. Results showed that a 4-log reduction of Escherichia coli (107 to hundreds CFU/mL) was achieved with an external applied voltage of 0.2 V, 0.3 mM Fe2+ and cathodic pH of 3.0. However, non-notable inactivation...

  6. Interrelationships of food safety and plant pathology: the life cycle of human pathogens on plants.

    Science.gov (United States)

    Barak, Jeri D; Schroeder, Brenda K

    2012-01-01

    Bacterial food-borne pathogens use plants as vectors between animal hosts, all the while following the life cycle script of plant-associated bacteria. Similar to phytobacteria, Salmonella, pathogenic Escherichia coli, and cross-domain pathogens have a foothold in agricultural production areas. The commonality of environmental contamination translates to contact with plants. Because of the chronic absence of kill steps against human pathogens for fresh produce, arrival on plants leads to persistence and the risk of human illness. Significant research progress is revealing mechanisms used by human pathogens to colonize plants and important biological interactions between and among bacteria in planta. These findings articulate the difficulty of eliminating or reducing the pathogen from plants. The plant itself may be an untapped key to clean produce. This review highlights the life of human pathogens outside an animal host, focusing on the role of plants, and illustrates areas that are ripe for future investigation.

  7. Poly(HEMA) brushes emerging as a new platform for direct detection of food pathogen in milk samples

    Czech Academy of Sciences Publication Activity Database

    Rodriguez-Emmenegger, Cesar Adolfo; Avramenko, Oxana; Brynda, Eduard; Škvor, J.; Bologna Alles, A.

    2011-01-01

    Roč. 26, č. 11 (2011), s. 4545-4551 ISSN 0956-5663 R&D Projects: GA AV ČR KAN200670701; GA ČR GAP503/10/0664 Institutional research plan: CEZ:AV0Z40500505 Keywords : surface plasmon resonance * food-borne pathogens * polymer brushes Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 5.602, year: 2011

  8. 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

  9. Comparative transcriptomics of pathogenic and non-pathogenic Listeria species

    Science.gov (United States)

    Wurtzel, Omri; Sesto, Nina; Mellin, J R; Karunker, Iris; Edelheit, Sarit; Bécavin, Christophe; Archambaud, Cristel; Cossart, Pascale; Sorek, Rotem

    2012-01-01

    Listeria monocytogenes is a human, food-borne pathogen. Genomic comparisons between L. monocytogenes and Listeria innocua, a closely related non-pathogenic species, were pivotal in the identification of protein-coding genes essential for virulence. However, no comprehensive comparison has focused on the non-coding genome. We used strand-specific cDNA sequencing to produce genome-wide transcription start site maps for both organisms, and developed a publicly available integrative browser to visualize and analyze both transcriptomes in different growth conditions and genetic backgrounds. Our data revealed conservation across most transcripts, but significant divergence between the species in a subset of non-coding RNAs. In L. monocytogenes, we identified 113 small RNAs (33 novel) and 70 antisense RNAs (53 novel), significantly increasing the repertoire of ncRNAs in this species. Remarkably, we identified a class of long antisense transcripts (lasRNAs) that overlap one gene while also serving as the 5′ UTR of the adjacent divergent gene. Experimental evidence suggests that lasRNAs transcription inhibits expression of one operon while activating the expression of another. Such a lasRNA/operon structure, that we named ‘excludon', might represent a novel form of regulation in bacteria. PMID:22617957

  10. 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

  11. 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

  12. Thermal Inactivation of Viruses

    Science.gov (United States)

    1977-10-01

    production. Proc. Soc. Exptl. Biol. Med. 116:174-177. Mayer, V. 1965. Study of the virulence of tick-borne encephalitis virus. IV. Thermosensitivity...inactivation of rabies and other rhabrtoviruses: stabilization of the chelating agent Ethylenediaminetetraacetic acid at physiological temperatures. Infec

  13. Toxicity of Food-Grade TiO2 to Commensal Intestinal and Transient Food-Borne Bacteria: New Insights Using Nano-SIMS and Synchrotron UV Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Joanna M. Radziwill-Bienkowska

    2018-04-01

    Full Text Available Titanium dioxide (TiO2 is commonly used as a food additive (E171 in the EU for its whitening and opacifying properties. However, a risk of intestinal barrier disruption, including dysbiosis of the gut microbiota, is increasingly suspected because of the presence of a nano-sized fraction in this additive. We hypothesized that food-grade E171 and Aeroxyde P25 (identical to the NM-105 OECD reference nanomaterial in the European Union Joint Research Centre interact with both commensal intestinal bacteria and transient food-borne bacteria under non-UV-irradiated conditions. Based on differences in their physicochemical properties, we expect a difference in their respective effects. To test these hypotheses, we chose a panel of eight Gram-positive/Gram-negative bacterial strains, isolated from different biotopes and belonging to the species Escherichia coli, Lactobacillus rhamnosus, Lactococcus lactis (subsp. lactis and cremoris, Streptococcus thermophilus, and Lactobacillus sakei. Bacterial cells were exposed to food-grade E171 vs. P25 in vitro and the interactions were explored with innovative (nanoimaging methods. The ability of bacteria to trap TiO2 was demonstrated using synchrotron UV fluorescence imaging with single cell resolution. Subsequent alterations in the growth profiles were shown, notably for the transient food-borne L. lactis and the commensal intestinal E. coli in contact with food-grade TiO2. However, for both species, the reduction in cell cultivability remained moderate, and the morphological and ultrastructural damages, observed with electron microscopy, were restricted to a small number of cells. E. coli exposed to food-grade TiO2 showed some internalization of TiO2 (7% of cells, observed with high-resolution nano-secondary ion mass spectrometry (Nano-SIMS chemical imaging. Taken together, these data show that E171 may be trapped by commensal and transient food-borne bacteria within the gut. In return, it may induce some

  14. Comparative study on the high pressure inactivation behavior of the Shiga toxin-producing Escherichia coli O104:H4 and O157:H7 outbreak strains and a non-pathogenic surrogate.

    Science.gov (United States)

    Reineke, Kai; Sevenich, Robert; Hertwig, Christian; Janßen, Traute; Fröhling, Antje; Knorr, Dietrich; Wieler, Lothar H; Schlüter, Oliver

    2015-04-01

    Enterohemorrhagic Escherichia coli strains cause each year thousands of illnesses, which are sometimes accompanied by the hemolytic uremic syndrome, like in the 2011 outbreak in Germany. For preservation thermal pasteurization is commonly used, which can cause unwanted quality changes. To prevent this high pressure treatment is a potential alternative. Within this study, the 2011 outbreak strain O104:H4, an O157:H7 and a non-pathogenic strain (DSM1116) were tested. The cells were treated in buffer (pH 7 and pH 5) and carrot juice (pH 5.1) in a pressure temperature range of 0.1-500 MPa and 20-70 °C. Flow cytometry was used to investigate the pressure impact on cell structures of the strain DSM1116. Both pathogenic strains had a much higher resistance in buffer and carrot juice than the non-pathogenic surrogate. Further, strains cultivated and treated at a lower pH-value showed higher pressure stability, presumably due to variations in the membrane composition. This was confirmed for the strain DSM1116 by flow cytometry. Cells cultivated and treated at pH 5 had a stronger ability to retain their membrane potential but showed higher rates of membrane permeabilization at pressures <200 MPa compared to cells cultivated and treated at pH 7. These cells had the lowest membrane permeabilization rate at around 125 MPa, possibly denoting that variations in the fatty acid composition and membrane fluidity contribute to this stabilization phenomenon. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. New trends in emerging pathogens.

    Science.gov (United States)

    Skovgaard, Niels

    2007-12-15

    The emergence of pathogens is the result of a number of impact in all parts of the food chain. The emerging technologies in food production explain how new pathogens can establish themselves in the food chain and compromise food safety. The impact of the food technology is analysed for several bacteria, such as Yersinia, Campylobacter, Arcobacter, Helicobacter pullorum, Enterobacter sakazakii, Mycobacterium avium spp. paratuberculosis, prions related to vCJD and others. The importance of the ability of many microbes to form VBNC forms is elaborated on. Research on culture independent methods may address this outstanding issue to the better understanding of emerging pathogens. The "demerging" of pathogens also occur, and examples of this are explained. The reaction of bacteria to stresses and sublethal treatments, and how exposure to one stress factor can confer resistance to other stresses, literally speaking causing contagious resistance, are explained. The implication of this e.g. in modern approaches of food preservation, such as Minimally processed Foods, is considerable. Intestinal colonization of EHEC may be regulated by Quorum sensing, and this ability of microbes plays an important role in the colonization of microbes in food and on food processing equipment, an important factor in the emergence of pathogens. The emergence of Saccharomyces cerevisiae, as an opportunistic human pathogen, used for centuries for food and production of alcoholic beverages, calls for research in molecular tools to distinguish between probiotic and clinical strains. Cyclospora cayetanensis and Norovirus outbreaks can no longer be designated as emerging pathogens, they share however one characteristic in the epidemiology of emerging nature, the importance of the hygiene in the primary production stage, including supply of potable water, and the application of GMP and the HACCP principles in the beginning of the food chain. Hepatitis E virus is a potential emerging food borne

  16. Selective inactivation of human immunodeficiency virus with subpicosecond near-infrared laser pulses

    International Nuclear Information System (INIS)

    Tsen, K T; Tsen, S-W D; Hung, C-F; Wu, T-C; Kiang, Juliann G

    2008-01-01

    We demonstrate for the first time that human immunodeficiency virus (HIV) can be inactivated by irradiation with subpicosecond near-infrared laser pulses at a moderate laser power density. By comparing the threshold laser power density for the inactivation of HIV with those of human red blood cells and mouse dendritic cells, we conclude that it is plausible to use the ultrashort pulsed laser to selectively inactivate blood-borne pathogens such as HIV while leaving sensitive materials like human red blood cells unharmed. This finding has important implications in the development of a new laser technology for disinfection of viral pathogens in blood products and in the clinic. (fast track communication)

  17. Inactivation of virus in solution by cold atmospheric pressure plasma: identification of chemical inactivation pathways

    Science.gov (United States)

    Aboubakr, Hamada A.; Gangal, Urvashi; Youssef, Mohammed M.; Goyal, Sagar M.; Bruggeman, Peter J.

    2016-05-01

    Cold atmospheric pressure plasma (CAP) inactivates bacteria and virus through in situ production of reactive oxygen and nitrogen species (RONS). While the bactericidal and virucidal efficiency of plasmas is well established, there is limited knowledge about the chemistry leading to the pathogen inactivation. This article describes a chemical analysis of the CAP reactive chemistry involved in the inactivation of feline calicivirus. We used a remote radio frequency CAP produced in varying gas mixtures leading to different plasma-induced chemistries. A study of the effects of selected scavengers complemented with positive control measurements of relevant RONS reveal two distinctive pathways based on singlet oxygen and peroxynitrous acid. The first mechanism is favored in the presence of oxygen and the second in the presence of air when a significant pH reduction is induced in the solution by the plasma. Additionally, smaller effects of the H2O2, O3 and \\text{NO}2- produced were also found. Identification of singlet oxygen-mediated 2-imidazolone/2-oxo-His (His  +14 Da)—an oxidative modification of His 262 comprising the capsid protein of feline calicivirus links the plasma induced singlet oxygen chemistry to viral inactivation.

  18. Thermal Inactivation of Feline Calicivirus in Pet Food Processing.

    Science.gov (United States)

    Haines, J; Patel, M; Knight, A I; Corley, D; Gibson, G; Schaaf, J; Moulin, J; Zuber, S

    2015-12-01

    Extrusion is the most common manufacturing process used to produce heat-treated dry dog and cat food (pet food) for domestic use and international trade. Due to reoccurring outbreaks of notifiable terrestrial animal diseases and their impact on international trade, experiments were undertaken to demonstrate the effectiveness of heat-treated extruded pet food on virus inactivation. The impact of extrusion processing in a pet food matrix on virus inactivation has not been previously reported and very few inactivation studies have examined the thermal inactivation of viruses in complex food matrices. The feline calicivirus vaccine strain FCV F-9 was used as a surrogate model RNA virus pathogen. Small-scale heat inactivation experiments using animal-derived pet food raw materials showed that a > 4 log10 reduction (log10 R) in infectivity occurred at 70 °C prior to reaching the minimum extrusion manufacturing operating temperature of 100 °C. As anticipated, small-scale pressure studies at extrusion pressure (1.6 MPa) showed no apparent effect on FCV F-9 inactivation. Additionally, FCV F-9 was shown not to survive the acidic conditions used to produce pet food palatants of animal origin that are typically used as a coating after the extrusion process.

  19. Swine manure post-treatment technologies for pathogenic organism inactivation Tecnologias de pós-tratamento de dejetos suínos para inativar organismos patogênicos

    Directory of Open Access Journals (Sweden)

    Patrícia Bilotta

    2013-04-01

    Full Text Available Swine manure agricultural use is a common practice in Brazil. Their physic-chemical characteristics favor its use as biofertilizer, but the presence of pathogens may become a risk to human health. This research presents a qualitative study of the main alternatives of pig manure disinfection, analyzing efficiency, advantages and limitations of each procedure. The disinfection studies reported in literature are based on the following treatments: alkaline, thermal, biological, chemical, and physical. The greater efficiencies are in thermal treatment (> 4 log: 60 °C, chemical treatment (3 to 4 log: 30mg Cl- L-1; 3 to 4 log: 40 mg O3 L-1 and physical treatment (3 a 4 log: 220 mJ UV radiation cm-2. The biological treatment (anaerobiosis also promotes the pathogen reduction of swine manure, however with lower efficiency (1 to 2 log. The selection of the treatment should consider: implementation and operation cost, necessity of preliminary treatment, efficiency obtained and destination of the treated manure (agricultural use, water reuse. Brazilian regulation does not have specific guidelines for the microbiological quality of animal production effluents that is very important to be considered due to confined animal feeding operation transformation in the last years in the country.O uso agrícola de dejetos suínos é uma prática comum no Brasil. Suas características físico-químicas favorecem seu aproveitamento como biofertilizante, porém a presença de patógenos pode representar um risco à saúde humana. Este trabalho apresenta um estudo qualitativo das principais alternativas de desinfecção de dejetos suínos, analisando eficiência, vantagens e limitações de cada procedimento. Os estudos de desinfecção reportados na literatura são baseados nos seguintes tratamentos: alcalino, térmico, biológico, químico e físico. As maiores eficiências de redução de patógenos estão no tratamento térmico (>4 log: 60 °C, tratamento químico (3

  20. 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...

  1. 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.

  2. Study on the overview on food borne bacteria in foodstuffs with animal origin in Iran; Part two: meat and meat products

    Directory of Open Access Journals (Sweden)

    S.S Shekarforoush

    2012-11-01

    Full Text Available The present study was aimed to review the contamination of meat and meat products with pathogenic bacteria in Iran. Little information is available about the contamination of meat and meat products with Bacillus cereus, because of the low contamination rate with the microorganism. The situation is about the same with Brucella, as the microorganism can hardly be seen in the muscles. However, not too many information is available on the contamination with Campylobacter jejuni, even though, the contamination of chicken meat with the campylobacter was addressed. Clostridium butolinum was the main discriminated bacterium to contaminate fish and its products and canned meats. Studies revealed that the big portions of meat were less likely contaminated with E. coli compared to the minced meat. Our study showed that the cross contamination of sausage is often occurred after the production chain. The situation was possibly attributed to the improvement of hygienic conditions of slaughter-houses and meat industries. Limited information was found on the contamination with Listeria monocytogenes and available data indicate that the microorganism can be present in meat and meat products. The most important factor for prevention of contamination is restricted inspection of slaughtered animals before slaughter and omission of diseased animals. Much information was accessible on the cross contamination with Salmonella in Iran and elsewhere. Salmonellosis is not common in the slaughtered animals despite its epidemiological and public health issues. The problem was also associated with the restricted inspection. Study about the staphylococcal contamination of meat was proportionately numerous. The contamination was mostly occurred in the minced Kebab in the warm seasons of the year. Generally, a low percentage of such contaminations were found in the meat products and sausage, in the surveys.

  3. 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.

  4. 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...

  5. 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.

  6. Radiation resistances and decontamination of common pathogenic bacteria contaminated in white scar oyster (Crassostrea belcheri) in Thailand

    International Nuclear Information System (INIS)

    Thupila, Nunticha; Ratana-arporn, Pattama; Wilaipun, Pongtep

    2011-01-01

    In Thailand, white scar oyster (Crassostrea belcheri) was ranked for premium quality, being most expensive and of high demand. This oyster is often eaten raw, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. As limited alternative methods are available to sterilize the oyster while preserving the raw characteristic, irradiation may be considered as an effective method for decontamination. In this study, the radiation resistance of pathogenic bacteria commonly contaminating the oyster and the optimum irradiation doses for sterilization of the most radiation resistant bacteria were investigated. The radiation decimal reduction doses (D 10 ) of Salmonella Weltevreden DMST 33380, Vibrio parahaemolyticus ATCC 17802 and Vibrio vulnificus DMST 5852 were determined in broth culture and inoculated oyster homogenate. The D 10 values of S. Weltevreden, V. parahaemolyticus and V. vulnificus in broth culture were 0.154, 0.132 and 0.059 kGy, while those of inoculated oyster homogenate were 0.330, 0.159 and 0.140 kGy, respectively. It was found that among the pathogens tested, S. Weltevreden was proved to be the most resistant species. An irradiation dose of 1.5 kGy reduced the counts of 10 5 CFU/g S. Weltevreden inoculated in oyster meat to an undetectable level. The present study indicated that a low-dose irradiation can improve the microbial quality of oyster and further reduce the risks from the food-borne pathogens without adversely affecting the sensory attributes.

  7. Radiation resistances and decontamination of common pathogenic bacteria contaminated in white scar oyster ( Crassostrea belcheri) in Thailand

    Science.gov (United States)

    Thupila, Nunticha; Ratana-arporn, Pattama; Wilaipun, Pongtep

    2011-07-01

    In Thailand, white scar oyster ( Crassostrea belcheri) was ranked for premium quality, being most expensive and of high demand. This oyster is often eaten raw, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. As limited alternative methods are available to sterilize the oyster while preserving the raw characteristic, irradiation may be considered as an effective method for decontamination. In this study, the radiation resistance of pathogenic bacteria commonly contaminating the oyster and the optimum irradiation doses for sterilization of the most radiation resistant bacteria were investigated. The radiation decimal reduction doses ( D10) of Salmonella Weltevreden DMST 33380, Vibrio parahaemolyticus ATCC 17802 and Vibrio vulnificus DMST 5852 were determined in broth culture and inoculated oyster homogenate. The D10 values of S. Weltevreden, V. parahaemolyticus and V. vulnificus in broth culture were 0.154, 0.132 and 0.059 kGy, while those of inoculated oyster homogenate were 0.330, 0.159 and 0.140 kGy, respectively. It was found that among the pathogens tested, S. Weltevreden was proved to be the most resistant species. An irradiation dose of 1.5 kGy reduced the counts of 10 5 CFU/g S. Weltevreden inoculated in oyster meat to an undetectable level. The present study indicated that a low-dose irradiation can improve the microbial quality of oyster and further reduce the risks from the food-borne pathogens without adversely affecting the sensory attributes.

  8. Some Pathogenic Bacteria of Livestock Origin as a Cause of Foodborne Diseases

    Directory of Open Access Journals (Sweden)

    Anni Kusumaningsih

    2010-09-01

    Full Text Available Food are essentialy required for cell metabolism in human physiologyc. Food should be free from biological, chemical, and physical contamination and also hazardous substances. All of them are able to disrupt physiological homeostatis resulting disorder or diseases. Diseases resulted by those contaminant are called food borne disease. One of the important contaminants is biological contaminant especially pathogenic bacterias. Some pathogenic bacteria such as Salmonella spp., Escherichia coli, Bacillus anthracis, Clostridium spp., Listeria monocytogenes, Campylobacter spp., Vibrio cholerae, Enterobacter sakazakii, Shigella, are able to cause symptomatic diseases. Overall, the general symptoms of the diseases due to pathogenic bacterial infection are gastric pain, nausea, vomit, headache, loss of appetite, fever, and also dehydration.

  9. 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.

  10. Exploration and conservation of bacterial genetic resources as bacteriocin producing inhibitory microorganisms to pathogen bacteria in livestock

    Directory of Open Access Journals (Sweden)

    Chotiah S

    2013-06-01

    Full Text Available Exploration and conservation of microorganisms producing bacteriocin was done as the primary study towards the collection of potential bacteria and its application in improving livestock health condition and inhibit food borne pathogens. Diferent kinds of samples such as beef cattle rectal swab, rumen fluids, cow’s milk, chicken gut content, goat’s milk were collected at Bogor cattle slaughter houses, poultry slaughter houses, dairy cattle and goat farms. A total of 452 bacterial isolates consisted of 73 Gram negative bacteria and 379 Gram positive bacteria were isolated from samples collected and screened for bacteriocin activity. Determination of bacteriocin activity with bioassay using agar spot tests were carried out on liquid and semisolid medium assessing 8 kins of indicators of pathogenic bacteria and food borne pathogens. A total of 51 bacteriocin producing strains were collected and some of the strains had high inhibitory zone such as Lactobacillus casei SS14C (26 mm, Enterobacter cloacae SRUT (24mm, Enterococcus faecalis SK39 (21mm and Bifidobacterium dentium SS14T (20mm respectively, to Salmonella typhimurium BCC B0046/ATCC 13311, E. coli O157 hemolytic BCC B2717, Listeria monocytogenes BCC B2767/ATCC 7764 and Escherichia coli VTEC O157 BCC B2687. Evaluation after conservation ex situ to all bacterocin producing strain at 5oC for 1 year in freeze drying ampoules in vacuum and dry condition revealed the decreasing viability starting from log 0.8 CFU/ml for Lactococcus and Leuconostoc to log 2.2. CFU/ml for Streptococcus. Result of the study showed that the bacteriocin producing strains obtained were offered a potential resource for preventing disease of livestock and food borne diseases.

  11. 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

    Derby, Salmonella Infantis, Yersinia enterocolitica, and a nonpathogenic Escherichia coli was studied on inoculated samples that were treated for 0.5 to 2.0 s. With one exception, no significant differences in reduction were observed among the bacterial types. After treatment for 0.5 s, the 0.9-to 1.......5-log reductions of E. coli were significantly higher than the 0.4- to 1.1-log reductions for Salmonella and Y. enterocolitica. Overall, reductions increased by increasing treatment time; reductions were 0.4 to 1.5 log CFU/cm(2) after treatment for 0.5 s and 2.0 to 3.6 log CFU/cm(2) after treatment...

  12. 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

  13. Emerging Preservation Techniques for Controlling Spoilage and Pathogenic Microorganisms in Fruit Juices

    Directory of Open Access Journals (Sweden)

    Kamal Rai Aneja

    2014-01-01

    Full Text Available Fruit juices are important commodities in the global market providing vast possibilities for new value added products to meet consumer demand for convenience, nutrition, and health. Fruit juices are spoiled primarily due to proliferation of acid tolerant and osmophilic microflora. There is also risk of food borne microbial infections which is associated with the consumption of fruit juices. In order to reduce the incidence of outbreaks, fruit juices are preserved by various techniques. Thermal pasteurization is used commercially by fruit juice industries for the preservation of fruit juices but results in losses of essential nutrients and changes in physicochemical and organoleptic properties. Nonthermal pasteurization methods such as high hydrostatic pressure, pulsed electric field, and ultrasound and irradiations have also been employed in fruit juices to overcome the negative effects of thermal pasteurization. Some of these techniques have already been commercialized. Some are still in research or pilot scale. Apart from these emerging techniques, preservatives from natural sources have also shown considerable promise for use in some food products. In this review article, spoilage, pathogenic microflora, and food borne outbreaks associated with fruit juices of last two decades are given in one section. In other sections various prevention methods to control the growth of spoilage and pathogenic microflora to increase the shelf life of fruit juices are discussed.

  14. Evaluation of molecular typing of foodborne pathogens in European reference laboratories from 2012 to 2013.

    Science.gov (United States)

    Schjørring, Susanne; Niskanen, Taina; Torpdahl, Mia; Björkman, Jonas T; Nielsen, Eva Møller

    2016-12-15

    In 2012, the European Centre for Disease Prevention and Control (ECDC) initiated external quality assessment (EQA) schemes for molecular typing including the National Public Health Reference Laboratories in Europe. The overall aim for these EQA schemes was to enhance the European surveillance of food-borne pathogens by evaluating and improving the quality and comparability of molecular typing. The EQAs were organised by Statens Serum Institut (SSI) and included Salmonella enterica subsp. enterica, verocytotoxin-producing Escherichia coli (VTEC) and Listeria monocytogenes. Inter-laboratory comparable pulsed-field gel electrophoresis (PFGE) images were obtained from 10 of 17 of the participating laboratories for Listeria, 15 of 25 for Salmonella, but only nine of 20 for VTEC. Most problems were related to PFGE running conditions and/or incorrect use of image acquisition. Analysis of the gels was done in good accordance with the provided guidelines. Furthermore, we assessed the multilocus variable-number tandem repeat analysis (MLVA) scheme for S. Typhimurium. Of 15 laboratories, nine submitted correct results for all analysed strains, and four had difficulties with one strain only. In conclusion, both PFGE and MLVA are prone to variation in quality, and there is therefore a continuous need for standardisation and validation of laboratory performance for molecular typing methods of food-borne pathogens in the human public health sector. This article is copyright of The Authors, 2016.

  15. Lack of correlation between virus barosensitivity and the presence of a viral envelope during inactivation of human rotavirus, vesicular stomatitis virus, and avian metapneumovirus by high-pressure processing.

    Science.gov (United States)

    Lou, Fangfei; Neetoo, Hudaa; Li, Junan; Chen, Haiqiang; Li, Jianrong

    2011-12-01

    High-pressure processing (HPP) is a nonthermal technology that has been shown to effectively inactivate a wide range of microorganisms. However, the effectiveness of HPP on inactivation of viruses is relatively less well understood. We systematically investigated the effects of intrinsic (pH) and processing (pressure, time, and temperature) parameters on the pressure inactivation of a nonenveloped virus (human rotavirus [HRV]) and two enveloped viruses (vesicular stomatitis virus [VSV] and avian metapneumovirus [aMPV]). We demonstrated that HPP can efficiently inactivate all tested viruses under optimal conditions, although the pressure susceptibilities and the roles of temperature and pH substantially varied among these viruses regardless of the presence of a viral envelope. We found that VSV was much more stable than most food-borne viruses, whereas aMPV was highly susceptible to HPP. When viruses were held for 2 min under 350 MPa at 4°C, 1.1-log, 3.9-log, and 5.0-log virus reductions were achieved for VSV, HRV, and aMPV, respectively. Both VSV and aMPV were more susceptible to HPP at higher temperature and lower pH. In contrast, HRV was more easily inactivated at higher pH, although temperature did not have a significant impact on inactivation. Furthermore, we demonstrated that the damage of virion structure by disruption of the viral envelope and/or capsid is the primary mechanism underlying HPP-induced viral inactivation. In addition, VSV glycoprotein remained antigenic although VSV was completely inactivated. Taken together, our findings suggest that HPP is a promising technology to eliminate viral contaminants in high-risk foods, water, and other fomites.

  16. 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 ...

  17. Toxoplasmosis as a food-borne infection

    Science.gov (United States)

    Đurković-Đaković, O.

    2017-09-01

    Toxoplasma gondii is a globally distributed parasite that infects all mammals, including one third of the world population. Long known to cause disease in the developing foetus and in immunosuppressed individuals, a body of data that has emerged in the past decades suggests its role in human pathology may be even more important. The WHO and FAO have recently established toxoplasmosis as a foodborne infection of global concern, with a disease burden the greatest of all parasitic infections. Transmission of toxoplasmosis occurs by ingesting tissue cysts from undercooked meat and meat products, and oocysts from the environment with contaminated fresh produce or water. This review provides an update on the current understanding of toxoplasmosis, focusing on the risk of infection from food of animal origin, with particular reference to the risk in Serbia and the region of South-East Europe.

  18. Tyrosinase inactivation in organic solvents.

    Science.gov (United States)

    Warrington, J C; Saville, B A

    1999-11-05

    The inactivation of the catecholase activity of mushroom tyrosinase was investigated under nonaqueous conditions. The enzyme was immobilized on glass beads, and assays were conducted in chloroform, toluene, amyl acetate, isopropyl ether, and butanol. The reaction components were pre-equilibrated for 2 weeks with a saturated salt solution at a water activity of 0.90. The initial reaction velocity varied between 1.3 x 10(3) mol product/((mol enzyme)(min)) in toluene and 8.7 x 10(3) mol product/((mol enzyme)(min)) in amyl acetate. The turnover number varied between 8.1 x 10(3) mol product/mol enzyme in toluene and 7.2 x 10(4) mol product/mol enzyme in amyl acetate. In each solvent, the tyrosinase reaction inactivation parameters were represented by a probabilistic model. Changes in the probability of inactivation were followed throughout the course of the reaction using a second model which relates the reaction velocity to the amount of product formed. These models reveal that the inactivation rate of tyrosinase decreases as the reaction progresses, and that the inactivation kinetics are independent of the quinone concentration in toluene, chloroform, butanol, and amyl acetate. Significant effects of quinone concentration were, however, observed in isopropyl ether. The likelihood of inactivation of the enzyme was found to be greatest toward the beginning of the reaction. In the latter phase of the reaction, inactivation probability was less and tended to remain constant until the completion of the reaction. Copyright 1999 John Wiley & Sons, Inc.

  19. Ammonia Inactivation of Ascaris Ova in Ecological Compost by Using Urine and Ash

    Science.gov (United States)

    Parzen, Rebecca E.; Mercado Guzmán, Álvaro

    2012-01-01

    Viable ova of Ascaris lumbricoides, an indicator organism for pathogens, are frequently found in feces-derived compost produced from ecological toilets, demonstrating that threshold levels of time, temperature, pH, and moisture content for pathogen inactivation are not routinely met. Previous studies have determined that NH3 has ovicidal properties for pathogens, including Ascaris ova. This research attempted to achieve Ascaris inactivation via NH3 under environmental conditions commonly found in ecological toilets and using materials universally available in an ecological sanitation setting, including compost (feces and sawdust), urine, and ash. Compost mixed with stored urine and ash produced the most rapid inactivation, with significant inactivation observed after 2 weeks and with a time to 99% ovum inactivation (T99) of 8 weeks. Compost mixed with fresh urine and ash achieved a T99 of 15 weeks, after a 4-week lag phase. Both matrices had relatively high total-ammonia concentrations and pH values of >9.24 (pKa of ammonia). In compost mixed with ash only, and in compost mixed with fresh urine only, inactivation was observed after an 11-week lag phase. These matrices contained NH3 concentrations of 164 to 173 and 102 to 277 mg/liter, respectively, when inactivation occurred, which was below the previously hypothesized threshold for inactivation (280 mg/liter), suggesting that a lower threshold NH3 concentration may be possible with a longer contact time. Other significant results include the hydrolysis of urea to ammonia between pH values of 10.4 and 11.6, above the literature threshold pH of 10. PMID:22582051

  20. Ammonia inactivation of Ascaris ova in ecological compost by using urine and ash.

    Science.gov (United States)

    McKinley, James W; Parzen, Rebecca E; Mercado Guzmán, Álvaro

    2012-08-01

    Viable ova of Ascaris lumbricoides, an indicator organism for pathogens, are frequently found in feces-derived compost produced from ecological toilets, demonstrating that threshold levels of time, temperature, pH, and moisture content for pathogen inactivation are not routinely met. Previous studies have determined that NH(3) has ovicidal properties for pathogens, including Ascaris ova. This research attempted to achieve Ascaris inactivation via NH(3) under environmental conditions commonly found in ecological toilets and using materials universally available in an ecological sanitation setting, including compost (feces and sawdust), urine, and ash. Compost mixed with stored urine and ash produced the most rapid inactivation, with significant inactivation observed after 2 weeks and with a time to 99% ovum inactivation (T(99)) of 8 weeks. Compost mixed with fresh urine and ash achieved a T(99) of 15 weeks, after a 4-week lag phase. Both matrices had relatively high total-ammonia concentrations and pH values of >9.24 (pK(a) of ammonia). In compost mixed with ash only, and in compost mixed with fresh urine only, inactivation was observed after an 11-week lag phase. These matrices contained NH(3) concentrations of 164 to 173 and 102 to 277 mg/liter, respectively, when inactivation occurred, which was below the previously hypothesized threshold for inactivation (280 mg/liter), suggesting that a lower threshold NH(3) concentration may be possible with a longer contact time. Other significant results include the hydrolysis of urea to ammonia between pH values of 10.4 and 11.6, above the literature threshold pH of 10.

  1. Effects of gamma and electron beam irradiation on the survival of pathogens inoculated into sliced and pizza cheeses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Joo [Department of Food Science and Technology, Chung-Ang University, Ansung, Gyunggi-do 456-756 (Korea, Republic of); Ham, Jun-Sang [Animal Products Processing Division, National Livestock Research Institute, RDA, Suwon 441-706 (Korea, Republic of); Lee, Ju-Woon [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Kim, Keehyuk [Department of Culinary Nutrition, Woosong University, Daejeon 300-718 (Korea, Republic of); Ha, Sang-Do [Department of Food Science and Technology, Chung-Ang University, Ansung, Gyunggi-do 456-756 (Korea, Republic of); Jo, Cheorun, E-mail: cheorun@cnu.ac.k [Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2010-06-15

    The objective of this study was to identify the efficacy of gamma and electron beam irradiation of the food-borne pathogens (Listeria monocytogenes and Staphylococcus aureus) in sliced and pizza cheeses commercially available in the Korean market. Total aerobic bacteria and yeast/mold in the cheeses ranged from 10{sup 2} to 10{sup 3} Log CFU/g. Irradiation of 1 kGy for sliced cheese and 3 kGy for pizza cheese were sufficient to lower the total aerobic bacteria to undetectable levels (10{sup 1} CFU/g). Pathogen inoculation test revealed that gamma irradiation was more effective than electron beam irradiation at the same absorbed dose, and the ranges of the D{sub 10} values were from 0.84 to 0.93 kGy for L. monocytogenes and from 0.60 to 0.63 kGy for S. aureus. Results suggest that a low dose irradiation can improve significantly the microbial quality and reduce the risk of contamination of sliced and pizza cheeses by the food-borne pathogens which can potentially occur during processing.

  2. Effects of gamma and electron beam irradiation on the survival of pathogens inoculated into sliced and pizza cheeses

    Science.gov (United States)

    Kim, Hyun-Joo; Ham, Jun-Sang; Lee, Ju-Woon; Kim, Keehyuk; Ha, Sang-Do; Jo, Cheorun

    2010-06-01

    The objective of this study was to identify the efficacy of gamma and electron beam irradiation of the food-borne pathogens ( Listeria monocytogenes and Staphylococcus aureus) in sliced and pizza cheeses commercially available in the Korean market. Total aerobic bacteria and yeast/mold in the cheeses ranged from 10 2 to 10 3 Log CFU/g. Irradiation of 1 kGy for sliced cheese and 3 kGy for pizza cheese were sufficient to lower the total aerobic bacteria to undetectable levels (10 1 CFU/g). Pathogen inoculation test revealed that gamma irradiation was more effective than electron beam irradiation at the same absorbed dose, and the ranges of the D 10 values were from 0.84 to 0.93 kGy for L. monocytogenes and from 0.60 to 0.63 kGy for S. aureus. Results suggest that a low dose irradiation can improve significantly the microbial quality and reduce the risk of contamination of sliced and pizza cheeses by the food-borne pathogens which can potentially occur during processing.

  3. Effects of gamma and electron beam irradiation on the survival of pathogens inoculated into sliced and pizza cheeses

    International Nuclear Information System (INIS)

    Kim, Hyun-Joo; Ham, Jun-Sang; Lee, Ju-Woon; Kim, Keehyuk; Ha, Sang-Do; Jo, Cheorun

    2010-01-01

    The objective of this study was to identify the efficacy of gamma and electron beam irradiation of the food-borne pathogens (Listeria monocytogenes and Staphylococcus aureus) in sliced and pizza cheeses commercially available in the Korean market. Total aerobic bacteria and yeast/mold in the cheeses ranged from 10 2 to 10 3 Log CFU/g. Irradiation of 1 kGy for sliced cheese and 3 kGy for pizza cheese were sufficient to lower the total aerobic bacteria to undetectable levels (10 1 CFU/g). Pathogen inoculation test revealed that gamma irradiation was more effective than electron beam irradiation at the same absorbed dose, and the ranges of the D 10 values were from 0.84 to 0.93 kGy for L. monocytogenes and from 0.60 to 0.63 kGy for S. aureus. Results suggest that a low dose irradiation can improve significantly the microbial quality and reduce the risk of contamination of sliced and pizza cheeses by the food-borne pathogens which can potentially occur during processing.

  4. Campylobacter jejuni: a brief overview on pathogenicity-associated factors and disease-mediating mechanisms.

    Science.gov (United States)

    Dasti, Javid I; Tareen, A Malik; Lugert, Raimond; Zautner, Andreas E; Gross, Uwe

    2010-04-01

    Campylobacter jejuni has long been recognized as a cause of bacterial food-borne illness, and surprisingly, it remains the most prevalent bacterial food-borne pathogen in the industrial world to date. Natural reservoirs for this Gram-negative, spiral-shaped bacterium are wild birds, whose intestines offer a suitable biological niche for the survival and dissemination of C. jejuni Chickens become colonized shortly after birth and are the most important source for human infection. In the last decade, effective intervention strategies to limit infections caused by this elusive pathogen were hindered mainly because of a paucity in understanding the virulence mechanisms of C. jejuni and in part, unavailability of an adequate animal model for the disease. However, recent developments in deciphering molecular mechanisms of virulence of C. jejuni made it clear that C. jejuni is a unique pathogen, being able to execute N-linked glycosylation of more than 30 proteins related to colonization, adherence, and invasion. Moreover, the flagellum is not only depicted to facilitate motility but as well secretion of Campylobacter invasive antigens (Cia). The only toxin of C. jejuni, the so-called cytolethal distending toxin (CdtA,B,C), seems to be important for cell cycle control and induction of host cell apoptosis and has been recognized as a major pathogenicity-associated factor. In contrast to other diarrhoea-causing bacteria, no other classical virulence factors have yet been identified in C. jejuni. Instead, host factors seem to play a major role for pathogenesis of campylobacteriosis of man. Indeed, several lines of evidence suggest exploitation of different adaptation strategies by this pathogen depending on its requirement, whether to establish itself in the natural avian reservoir or during the course of human infection. (c) 2009 Elsevier GmbH. All rights reserved.

  5. Comparative Inactivation of Murine Norovirus, Human Adenovirus, and Human JC Polyomavirus by Chlorine in Seawater

    Science.gov (United States)

    de Abreu Corrêa, Adriana; Carratala, Anna; Barardi, Celia Regina Monte; Calvo, Miquel; Bofill-Mas, Sílvia

    2012-01-01

    Viruses excreted by humans affect the commercial and recreational use of coastal water. Shellfish produced in contaminated waters have been linked to many episodes and outbreaks of viral gastroenteritis, as well as other food-borne diseases worldwide. The risk can be reduced by appropriate treatment following harvesting and by depuration. The kinetics of inactivation of murine norovirus 1 and human adenovirus 2 in natural and artificial seawater by free available chlorine was studied by quantifying genomic copies (GC) using quantitative PCR and infectious viral particles (PFU). Human JC polyomavirus Mad4 kinetics were evaluated by quantitative PCR. DNase or RNase were used to eliminate free genomes and assess potential viral infectivity when molecular detection was performed. At 30 min of assay, human adenovirus 2 showed 2.6- and 2.7-log10 GC reductions and a 2.3- and 2.4-log10 PFU reductions in natural and artificial seawater, respectively, and infectious viral particles were still observed at the end of the assay. When DNase was used prior to the nucleic acid extraction the kinetic of inactivation obtained by quantitative PCR was statistically equivalent to the one observed by infectivity assays. For murine norovirus 1, 2.5, and 3.5-log10 GC reductions were observed in natural and artificial seawater, respectively, while no viruses remained infectious after 30 min of contact with chlorine. Regarding JC polyomavirus Mad4, 1.5- and 1.1-log10 GC reductions were observed after 30 min of contact time. No infectivity assays were conducted for this virus. The results obtained provide data that might be applicable to seawater used in shellfish depuration. PMID:22773637

  6. Nosocomial pathogens

    African Journals Online (AJOL)

    remains an important problem in intensive care units. Hospital wards had been shown to act as reservoirs of pathogenic microorganisms associated with infection. To assess the prevalence of pathogenic organisms in the environment of the neonatal unit, 92 swabs were randomly collected from cots, incubators and various ...

  7. Human PIEZO1: removing inactivation.

    Science.gov (United States)

    Bae, Chilman; Gottlieb, Philip A; Sachs, Frederick

    2013-08-20

    PIEZO1 is an inactivating eukaryotic cation-selective mechanosensitive ion channel. Two sites have been located in the channel that when individually mutated lead to xerocytotic anemia by slowing inactivation. By introducing mutations at two sites, one associated with xerocytosis and the other artificial, we were able to remove inactivation. The double mutant (DhPIEZO1) has a substitution of arginine for methionine (M2225R) and lysine for arginine (R2456K). The loss of inactivation was accompanied by ∼30-mmHg shift of the activation curve to lower pressures and slower rates of deactivation. The slope sensitivity of gating was the same for wild-type and mutants, indicating that the dimensional changes between the closed and open state are unaffected by the mutations. The unitary channel conductance was unchanged by mutations, so these sites are not associated with pore. DhPIEZO1 was reversibly inhibited by the peptide GsMTx4 that acted as a gating modifier. The channel kinetics were solved using complex stimulus waveforms and the data fit to a three-state loop in detailed balance. The reaction had two pressure-dependent rates, closed to open and inactivated to closed. Pressure sensitivity of the opening rate with no sensitivity of the closing rate means that the energy barrier between them is located near the open state. Mutant cycle analysis of inactivation showed that the two sites interacted strongly, even though they are postulated to be on opposite sides of the membrane. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  8. Seasonal Inactivated Influenza Virus Vaccines

    OpenAIRE

    Couch, Robert B.

    2008-01-01

    Inactivated influenza virus vaccines are the primary modality used for prevention of influenza. A system of annual identification of new strains causing illnesses, selections for vaccines, chick embryo growth, inactivation, processing, packaging, distribution and usage has been in place for decades. Current vaccines contain 15 µg of the HA of an A/H1N1, A/H3N2 and B strain and are given parenterally to induce serum anti-HA antibody for prevention of subsequent infection and illness from natur...

  9. Pathogen Reduction and Hazard Analysis and Critical Control Point (HACCP) systems for meat and poultry. USDA.

    Science.gov (United States)

    Hogue, A T; White, P L; Heminover, J A

    1998-03-01

    The United States Department of Agriculture (USDA) Food Safety Inspection Service (FSIS) adopted Hazard Analysis and Critical Control Point Systems and established finished product standards for Salmonella in slaughter plants to improve food safety for meat and poultry. In order to make significant improvements in food safety, measures must be taken at all points in the farm-to-table chain including production, transportation, slaughter, processing, storage, retail, and food preparation. Since pathogens can be introduced or multiplied anywhere along the continuum, success depends on consideration and comparison of intervention measures throughout the continuum. Food animal and public health veterinarians can create the necessary preventative environment that mitigates risks for food borne pathogen contamination.

  10. 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

  11. 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.

  12. Inactivation of norovirus on dry copper alloy surfaces.

    Directory of Open Access Journals (Sweden)

    Sarah L Warnes

    Full Text Available Noroviruses (family Caliciviridae are the primary cause of viral gastroenteritis worldwide. The virus is highly infectious and touching contaminated surfaces can contribute to infection spread. Although the virus was identified over 40 years ago the lack of methods to assess infectivity has hampered the study of the human pathogen. Recently the murine virus, MNV-1, has successfully been used as a close surrogate. Copper alloys have previously been shown to be effective antimicrobial surfaces against a range of bacteria and fungi. We now report rapid inactivation of murine norovirus on alloys, containing over 60% copper, at room temperature but no reduction of infectivity on stainless steel dry surfaces in simulated wet fomite and dry touch contamination. The rate of inactivation was initially very rapid and proportional to copper content of alloy tested. Viral inactivation was not as rapid on brass as previously observed for bacteria but copper-nickel alloy was very effective. The use of chelators and quenchers of reactive oxygen species (ROS determined that Cu(II and especially Cu(I ions are still the primary effectors of toxicity but quenching superoxide and hydroxyl radicals did not confer protection. This suggests Fenton generation of ROS is not important for the inactivation mechanism. One of the targets of copper toxicity was the viral genome and a reduced copy number of the gene for a viral encoded protein, VPg (viral-protein-genome-linked, which is essential for infectivity, was observed following contact with copper and brass dry surfaces. The use of antimicrobial surfaces containing copper in high risk closed environments such as cruise ships and care facilities could help to reduce the spread of this highly infectious and costly pathogen.

  13. Inactivation of Norovirus on Dry Copper Alloy Surfaces

    Science.gov (United States)

    Warnes, Sarah L.; Keevil, C. William

    2013-01-01

    Noroviruses (family Caliciviridae) are the primary cause of viral gastroenteritis worldwide. The virus is highly infectious and touching contaminated surfaces can contribute to infection spread. Although the virus was identified over 40 years ago the lack of methods to assess infectivity has hampered the study of the human pathogen. Recently the murine virus, MNV-1, has successfully been used as a close surrogate. Copper alloys have previously been shown to be effective antimicrobial surfaces against a range of bacteria and fungi. We now report rapid inactivation of murine norovirus on alloys, containing over 60% copper, at room temperature but no reduction of infectivity on stainless steel dry surfaces in simulated wet fomite and dry touch contamination. The rate of inactivation was initially very rapid and proportional to copper content of alloy tested. Viral inactivation was not as rapid on brass as previously observed for bacteria but copper-nickel alloy was very effective. The use of chelators and quenchers of reactive oxygen species (ROS) determined that Cu(II) and especially Cu(I) ions are still the primary effectors of toxicity but quenching superoxide and hydroxyl radicals did not confer protection. This suggests Fenton generation of ROS is not important for the inactivation mechanism. One of the targets of copper toxicity was the viral genome and a reduced copy number of the gene for a viral encoded protein, VPg (viral-protein-genome-linked), which is essential for infectivity, was observed following contact with copper and brass dry surfaces. The use of antimicrobial surfaces containing copper in high risk closed environments such as cruise ships and care facilities could help to reduce the spread of this highly infectious and costly pathogen. PMID:24040380

  14. 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.

  15. 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.

  16. 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...

  17. 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...

  18. Sample preparation and assay refinements for pathogen detection platforms

    Science.gov (United States)

    Lim, Daniel V.; Kearns, Elizabeth A.; Leskinen, Stephaney D.; Magaña, Sonia; Stroot, Joyce M.; Hunter, Dawn M.; Schlemmer, Sarah M.

    2009-02-01

    Food-borne and waterborne microbial pathogens are a potential problem in biowarfare and public health. Such pathogens can affect the health, combat readiness, and effectiveness of the warfighter in a battlefield environment and present potential threats to the civilian population through intentional or natural contamination of food and water. Conventional procedures to detect and identify microbial pathogens in food, water, and other materials can take days to perform and may provide inconclusive information. Research at the University of South Florida's Advanced Biosensors Laboratory (ABL) focuses on development of sample processing procedures and biosensor-based assays for rapid detection of biothreat agents. Rapid processing methods, including use of an automated concentrator of microorganisms in water, have been developed for complex matrix samples including ground beef, apple juice, produce, potable water and recreational water, enabling such samples to be directly tested by biosensor assays for target analytes. Bacillus atrophaeus spores and other bacteria can be concentrated from potable and recreational water at low levels with a dead-end hollow-fiber ultrafiltration concentration system. Target bacteria recovered by these processing procedures can be identified by evanescent wave, fiber optic biosensors or other detection platforms. Fiber optic biosensor assays have been improved to include subsequent PCR analysis and viability determination of captured target bacteria using broth enrichment and/or ATP luminescence.

  19. UV light inactivation of hepatitis A virus, Aichi virus, and feline calicivirus on strawberries, green onions, and lettuce.

    Science.gov (United States)

    Fino, Viviana R; Kniel, Kalmia E

    2008-05-01

    A majority of illnesses caused by foodborne viruses are associated with fresh produce. Fruits and vegetables may be considered high-risk foods, as they are often consumed raw without a specific inactivation step. Therefore, there is a need to evaluate nonthermal treatments for the inactivation of foodborne pathogens. This study investigates the UV inactivation of three viruses: feline calicivirus (a surrogate for norovirus), and two picornaviruses, hepatitis A virus and Aichi virus. Three produce types were selected for their different surface topographies and association with outbreaks. Green onions, lettuce, and strawberries were individually spot inoculated with 10(7) to 10(9) 50% tissue culture infective doses (TCID50) of each virus per ml and exposed to UV light at various doses (culture and compared with untreated recovered virus. UV light applied to contaminated lettuce resulted in inactivation of 4.5 to 4.6 log TCID50/ml; for contaminated green onions, inactivation ranged from 2.5 to 5.6 log TCID50/ml; and for contaminated strawberries, inactivation ranged from 1.9 to 2.6 log TCID50/ml for the three viruses tested. UV light inactivation on the surface of lettuce is more effective than inactivation on the other two produce items. Consistently, the lowest results were observed in the inactivation of viruses on strawberries. No significant differences (P > 0.05) for virus inactivation were observed among the three doses applied (40, 120, and 240 mW s/cm2) on the produce, with the exception of hepatitis A virus and Aichi virus inactivation on green onions, where inactivation continued at 120 mW s/cm2 (P < 0.05).

  20. 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.

  1. Inactivation of porcine epidemic diarrhea virus using heated water

    Directory of Open Access Journals (Sweden)

    Michele M. Zentkovich

    2016-12-01

    Full Text Available Porcine epidemic diarrhea virus (PEDV is a very contagious swine pathogen that spreads easily via the fecal-oral route, notably from contaminated fomites. The present study investigated heated water as a method for rapid thermal inactivation of PEDV. Cell-culture adapted PEDV was treated with water at varying temperatures and viral titers were measured at multiple time points post-treatment. Viable PEDV was not recovered after a ten second or longer treatment with water heated to ≥76 °C; however, PEDV nucleic acid was detected in all samples regardless of treatment. Hot water decontamination could be considered in settings where chemical disinfection is impractical.

  2. 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.

  3. Inactivation of allergens and toxins.

    Science.gov (United States)

    Morandini, Piero

    2010-11-30

    Plants are replete with thousands of proteins and small molecules, many of which are species-specific, poisonous or dangerous. Over time humans have learned to avoid dangerous plants or inactivate many toxic components in food plants, but there is still room for ameliorating food crops (and plants in general) in terms of their allergens and toxins content, especially in their edible parts. Inactivation at the genetic rather than physical or chemical level has many advantages and classical genetic approaches have resulted in significant reduction of toxin content. The capacity, offered by genetic engineering, of turning off (inactivating) specific genes has opened up the possibility of altering the plant content in a far more precise manner than previously available. Different levels of intervention (genes coding for toxins/allergens or for enzymes, transporters or regulators involved in their metabolism) are possible and there are several tools for inactivating genes, both direct (using chemical and physical mutagens, insertion of transposons and other genetic elements) and indirect (antisense RNA, RNA interference, microRNA, eventually leading to gene silencing). Each level/strategy has specific advantages and disadvantages (speed, costs, selectivity, stability, reversibility, frequency of desired genotype and regulatory regime). Paradigmatic examples from classical and transgenic approaches are discussed to emphasize the need to revise the present regulatory process. Reducing the content of natural toxins is a trade-off process: the lesser the content of natural toxins, the higher the susceptibility of a plant to pests and therefore the stronger the need to protect plants. As a consequence, more specific pesticides like Bt are needed to substitute for general pesticides. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on a review on the European Union Summary reports on trends and sources zoonoses, zoonotic agents and food-borne outbreaks in 2009 and 2010 – specifically for the data on Salmonella, Campylobacter, verotoxigenic Escherichia coli, , Listeria monocytogenes and foodborne outbreaks

    DEFF Research Database (Denmark)

    Hald, Tine

    The European Union (EU) Summary Reports on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2009 and 2010 – specifically for the data on Salmonella, Campylobacter, verotoxigenic Escherichia coli, Listeria monocytogenes and foodborne outbreaks was reviewed. The main......-specific trends, the impact of sample sizes, weight of samples and methodologies should be considered, as these variables could otherwise lead to misinterpretation of the data. Incidence data alone do not provide a full picture of the public health burden of zoonotic diseases. Fatalities provide another important...

  5. Escherichia coli O157:H7 - An Emerging Pathogen in foods of Animal Origin

    Directory of Open Access Journals (Sweden)

    Ch. Bindu Kiranmayi

    Full Text Available Escherichia coli O157:H7 is an emerging public health concern in most countries of the world. E. coli O157:H7 was known to be a human pathogen for nearly 24 years. EHEC O157 infection is estimated to be the fourth most costly food borne disease in Canada and USA, not counting the cost of possible litigation. E. coli O157:H7 and Salmonella are the leading causes of produce related outbreaks, accounting for 20 and 30% respectively. The authority of the Federal Meat Inspection Act, FSIS (Food Safety and Inspection Service declared Escherichia coli O157:H7, an adulterant in raw ground beef and enforced “zero tolerance” (USDA-FSIS, 17 December 1998. Because of the severity of these illnesses and the apparent low infective dose (less than 10 cells, Escherichia coli O157:H7 is considered one of the most serious of known food borne pathogens. Escherichia coli O157:H7 is mainly pathogenic to human but in cattle and other animals, it did not induce any clinical disease except diarrhea. So, these animals act as carriers to Escherichia coli O157:H7. The majority transmission is through eating of undercooked contaminated ground meat and consumption of raw milk, raw vegetables, fruits contaminated by water, cheese, curd and also through consumption of sprouts, lettuce and juice. The conventional isolation procedure includes growth in enrichment broth like modified EC (E. coli broth or modified tryptic soy broth (mTSB Since the infection primarily occurs via faeco-oral route, the preventive measures include food hygiene measures like proper cooking of meat, consumption of pasteurized milk, washing fruits and vegetables especially those to be eaten raw and drinking chlorine treated water and personnel hygiene measures like washing hands after toilet visits. [Veterinary World 2010; 3(8.000: 382-389

  6. A highly sensitive and flexible magnetic nanoprobe labeled immunochromatographic assay platform for pathogen Vibrio parahaemolyticus.

    Science.gov (United States)

    Liu, Yingying; Zhang, Zhaohuan; Wang, Yilong; Zhao, Yong; Lu, Ying; Xu, Xiaowei; Yan, Jun; Pan, Yingjie

    2015-10-15

    A magnetic nanoprobe labeled immunochromatographic test strip (MNP/ICTS) was developed to detect food-borne pathogen Vibrio parahaemolyticus. Specific antibody against V. parahaemolyticus was used as test line by coating onto the nitrocellulose membrane. Magnetic nanoprobe was prepared by immobilizing the specific antibody onto the surface of superparamagnetic nanoparticles. Specificity and sensitivity of the MNP/ICTS system were verified by artificially contaminated shrimp homogenate samples. Reliability and application feasibility of the MNP/ICTS system were demonstrated by using seafood samples (n=36). Comparing with polymerase chain reaction (PCR) and traditional culture methods, the MNP/ICTS system is found to be not only a rapid qualitative analysis (~10 min), but also an accurately quantitative detection platform. Through its rapid magnetic separation property, the MNP/ICTS system is capable to flexibly combine with a sample enrichment and pre-incubation process. This combination makes the qualitative sensitivity for the food samples surged more than 100-fold. A naked-eye observation of 1.58×10(2) CFU/g V. parahaemolyticus was realized. This sensitivity could meet the V. parahaemolyticus test threshold value in many countries. Also, the total sample pre-treatment plus MNP/ICTS assay only needs about 4.5h. Namely, we can get test results in a day. Hence, the developed MNP/ICTS assay platform is simple, rapid and highly sensitive. It is a flexible test platform for pathogen detection. The favorable comparison with PCR and culture methods further proves that the developed MNP/ICTS is applicable into food-borne pathogen or other areas where a simple, rapid, sensitive and point-of-care analysis is desirable. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. The Food Production Environment and the Development of Antimicrobial Resistance in Human Pathogens of Animal Origin

    Directory of Open Access Journals (Sweden)

    Manjusha Lekshmi

    2017-03-01

    Full Text Available Food-borne pathogens are a serious human health concern worldwide, and the emergence of antibiotic-resistant food pathogens has further confounded this problem. Once-highly-efficacious antibiotics are gradually becoming ineffective against many important pathogens, resulting in severe treatment crises. Among several reasons for the development and spread of antimicrobial resistance, their overuse in animal food production systems for purposes other than treatment of infections is prominent. Many pathogens of animals are zoonotic, and therefore any development of resistance in pathogens associated with food animals can spread to humans through the food chain. Human infections by antibiotic-resistant pathogens such as Campylobacter spp., Salmonella spp., Escherichia coli and Staphylococcus aureus are increasing. Considering the human health risk due to emerging antibiotic resistance in food animal–associated bacteria, many countries have banned the use of antibiotic growth promoters and the application in animals of antibiotics critically important in human medicine. Concerted global efforts are necessary to minimize the use of antimicrobials in food animals in order to control the development of antibiotic resistance in these systems and their spread to humans via food and water.

  8. 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

  9. 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.

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

    Science.gov (United States)

    Sridhar, Saranya; Brokstad, Karl A.; Cox, Rebecca J.

    2015-01-01

    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. PMID:26343192

  11. Ozone inactivation of norovirus surrogates on fresh produce.

    Science.gov (United States)

    Hirneisen, K A; Markland, S M; Kniel, K E

    2011-05-01

    Preharvest contamination of produce by foodborne viruses can occur through a variety of agents, including animal feces/manures, soil, irrigation water, animals, and human handling. Problems of contamination are magnified by potential countrywide distribution. Postharvest processing of produce can involve spraying, washing, or immersion into water with disinfectants; however, disinfectants, including chlorine, have varying effects on viruses and harmful by-products pose a concern. The use of ozone as a disinfectant in produce washes has shown great promise for bacterial pathogens, but limited research exists on its efficacy on viruses. This study compares ozone inactivation of human norovirus surrogates (feline calicivirus [FCV] and murine norovirus [MNV]) on produce (green onions and lettuce) and in sterile water. Green onions and lettuce inoculated with FCV or MNV were treated with ozone (6.25 ppm) for 0.5- to 10-min time intervals. Infectivity was determined by 50% tissue culture infectious dose (TCID(50)) and plaque assay for FCV and MNV, respectively. After 5 min of ozone treatment, >6 log TCID(50)/ml of FCV was inactivated in water and ∼2-log TCID(50)/ml on lettuce and green onions. MNV inoculated onto green onions and lettuce showed a >2-log reduction after 1 min of ozone treatment. The food matrix played the largest role in protection against ozone inactivation. These results indicate that ozone is an alternative method to reduce viral contamination on the surface of fresh produce.

  12. Viruses - from pathogens to vaccine carriers.

    Science.gov (United States)

    Small, Juliana C; Ertl, Hildegund C J

    2011-10-01

    Vaccination is mankind's greatest public health success story. By now vaccines to many of the viruses that once caused fatal childhood diseases are routinely used throughout the world. Traditional methods of vaccine development through inactivation or attenuation of viruses have failed for some of the most deadly human pathogens, necessitating new approaches. Genetic modification of viruses not only allows for their attenuation but also for incorporation of sequences from other viruses, turning one pathogen into a vaccine carrier for another. Recombinant viruses have pros and cons as vaccine carriers, as discussed below using vectors based on adenovirus, herpesvirus, flavivirus, and rhabdovirus as examples.

  13. Inactivation of internalized and surface contaminated enteric viruses in green onions.

    Science.gov (United States)

    Hirneisen, Kirsten A; Kniel, Kalmia E

    2013-09-02

    With increasing outbreaks of gastroenteritis associated with produce, it is important to assess interventions to reduce the risk of illness. UV, ozone and high pressure are non-thermal processing technologies that have potential to inactivate human pathogens on produce and allow the retention of fresh-like organoleptic properties. The objective of this study was to determine if UV, ozone, and high pressure are effective technologies compared to traditional chlorine spray on green onions to reduce enteric viral pathogens and to determine the effect of location of the virus (surface or internalized) on the efficacy of these processes. Mature green onion plants were inoculated with murine norovirus (MNV), hepatitis A virus (HAV) and human adenovirus type 41 (Ad41) either on the surface through spot inoculation or through inoculating contaminated hydroponic solution allowing for uptake of the virus into the internal tissues. Inoculated green onions were treated with UV (240 mJ s/cm(2)), ozone (6.25 ppm for 10 min), pressure (500 MPa, for 5 min at 20°C), or sprayed with calcium hypochlorite (150 ppm, 4°C). Viral inactivation was determined by comparing treated and untreated inoculated plants using cell culture infectivity assays. Processing treatments were observed to greatly affect viral inactivation. Viral inactivation for all three viruses was greatest after pressure treatment and the lowest inactivation was observed after chlorine and UV treatment. Both surface inoculated viruses and viruses internalized in green onions were inactivated to some extent by these post-harvest processing treatments. These results suggest that ozone and high pressure processes aimed to reduce the level of microbial contamination of produce have the ability to inactivate viruses if they become localized in the interior portions of produce. © 2013.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ubomba-Jaswa, E; Boyle, M A R; McGuigan, K G [Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2 (Ireland)], E-mail: kmcguigan@rcsi.ie

    2008-02-01

    Solar Disinfection (SODIS) is a low cost water treatment method currently used in communities that do not have year round access to safe water. However, there is still reluctance in widespread adoption of this treatment method due to a number 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 under simulated sunlight conditions and following a natural temperature profile. EPEC was exposed to simulated sunlight (885Wm{sup -2}) for periods up to a cumulative time of 4 hours. Inactivation was determined by a log reduction in growth of the organisms. The temperature (deg. C) of the water was taken at every time point. After 4 hours exposure EPEC was completely inactivated (7 log reduction) by SODIS. Imposing a realistic water temperature profile (min-max) concomitant with irradiation produces a greater kill of EPEC. Maintaining simulated sunlight experiments at a high fixed temperature may result in over-estimation of inactivation. Following a natural water temperature profile will result in more reliable inactivation comparable with those that might be obtained under natural sunlight conditions.

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

    Science.gov (United States)

    Ubomba-Jaswa, E.; Boyle, M. A. R.; McGuigan, K. G.

    2008-02-01

    Solar Disinfection (SODIS) is a low cost water treatment method currently used in communities that do not have year round access to safe water. However, there is still reluctance in widespread adoption of this treatment method due to a number 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 under simulated sunlight conditions and following a natural temperature profile. EPEC was exposed to simulated sunlight (885Wm-2) for periods up to a cumulative time of 4 hours. Inactivation was determined by a log reduction in growth of the organisms. The temperature (°C) of the water was taken at every time point. After 4 hours exposure EPEC was completely inactivated (7 log reduction) by SODIS. Imposing a realistic water temperature profile (min-max) concomitant with irradiation produces a greater kill of EPEC. Maintaining simulated sunlight experiments at a high fixed temperature may result in over --estimation of inactivation. Following a natural water temperature profile will result in more reliable inactivation comparable with those that might be obtained under natural sunlight conditions.

  16. A review on the beneficial aspects of food processing.

    NARCIS (Netherlands)

    Boekel, van M.A.J.S.; Fogliano, V.; Pellegrini, N.; Stanton, C.; Scholz, G.; Lalljie, S.P.D.; Somoza, V.; Knorr, D.; Rao Jasti, P.; Eisenbrand, G.

    2010-01-01

    The manuscript reviews beneficial aspects of food processing with main focus on cooking/heat treatment, including other food-processing techniques (e.g. fermentation). Benefits of thermal processing include inactivation of food-borne pathogens, natural toxins or other detrimental constituents,

  17. Volatile sulfur compounds in foods as a result of ionizing radiation

    Science.gov (United States)

    Ionizing radiation improves food safety and extends shelf life by inactivating food-borne pathogens and spoilage microorganisms. However, irradiation may induce the development of an off-odor, particularly at high doses. The off-odor has been called “irradiation odor”. Substantial evidence suggests ...

  18. Sensitivity of Pseudomonas fluorescens to gamma irradiation following surface inoculations on romaine lettuce and baby spinach

    Science.gov (United States)

    Irradiation of fresh fruits and vegetables is a post-harvest intervention measure often used to inactivate pathogenic food-borne microbes. We evaluated the sensitivity of Pseudomonas fluorescens strains (2-79, Q8R1, Q287) to gamma irradiation following surface inoculations on romaine lettuce and spi...

  19. The application of loop-mediated isothermal amplification (LAMP) in food testing for bacterial pathogens and fungal contaminants.

    Science.gov (United States)

    Niessen, Ludwig; Luo, Jie; Denschlag, Carla; Vogel, Rudi F

    2013-12-01

    Bacterial pathogens and toxicants, parasites as well as mycotoxin producing fungi are the major biotic factors influencing the safety of food. Moreover, viral infections and prions may be present as quasi biotic challenging factors. A vast array of culture dependent analytical methods and protocols for food safety testing has been developed during the past decades. Presently, protocols involving molecular biological techniques such as PCR-based nucleic acid amplification and hybridization have become available for many of the known pathogens with their major advantages being rapidness, high sensitivity and specificity. However, this type of assays is still quite labor- and cost intensive and mostly cannot be operated directly in the field. Recently, loop-mediated isothermal amplification (LAMP) of DNA has emerged as an alternative to the use of PCR-based methods not only in food safety testing but also in a wide array of application. Its advantages over PCR-based techniques are even shorter reaction time, no need for specific equipment, high sensitivity and specificity as well as comparably low susceptibility to inhibitors present in sample materials which enables detection of the pathogens in sample materials even without time consuming sample preparation. The present article presents a critical review of the application of LAMP-based methods and their usefulness in detecting and identifying food borne bacterial pathogens and toxicants as well as mycotoxin producing food borne fungi as compared to other methods. Moreover does it elaborate on new developments in the design and automation of LAMP-based assays and their implications for the future developments of food testing. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Pathogens Contamination Level Reduction on Beef Using Organic Acids Decontamination Methods

    Directory of Open Access Journals (Sweden)

    Sorin Daniel DAN

    2017-11-01

    Full Text Available In this study we aimed to assess the efficiency of organic acids in different concentrations regarding pathogens as Salmonella, Listeria and Escherichia on beef, which can cause food borne illness in humans. The samples were sterilized using UV radiation for 30 minutes, afterwards being contaminated with 1 ml of microbial suspension (0.5 MacFarland. We used reference bacterial strains for Salmonella Enteritidis, Escherichia coli and Listeria monocytogenes. The samples were subjected to decontamination procedure by introducing 25mL of solution of lactic, acetic or citric acid in concentration of 1%, 2% and 3%. The results showed a reduction of initial pathogen load, ranging from 0.32 to 7.78 log CFU/g, depending on the type of acid, concentration and pathogen sensitivity. After decontamination, standardized methods have been used for the isolation of pathogenic germs. Based on statistical analysis we conclude that pathogens have a different sensitivity to the action of acid solutions, their sensitivity in ascending order being: Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli. Among the organic acids, the most efficient was lactic acid, followed by acetic acid and less efficient citric acid. The greatest reduction of germs was determined by the concentration of 3%.

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

    Science.gov (United States)

    2016-10-01

    proposes to determine the efficacy of using a pathogen inactivation technique (Mirasol) coupled with a platelet additive solution (PAS) to extend the life...participation. • Subjects must have good veins for apheresis platelet collection and drawing blood samples. • Subjects of child-bearing potential (either male or

  2. Irradiation of ready-to-eat meats for pathogen control

    Science.gov (United States)

    Ionizing (gamma) radiation is a safe and effective technology that can be used to inactivate foodborne pathogens in a variety of food types, including ready-to-eat (RTE) meats. The U.S. Food and Drug Administration is currently evaluating a petition to allow irradiation of RTE meats in the U.S. In t...

  3. X-chromosome inactivation and escape

    Indian Academy of Sciences (India)

    2015-11-06

    Nov 6, 2015 ... Abstract. X-chromosome inactivation, which was discovered by Mary Lyon in 1961 results in random silencing of one X chromosome in female mammals. This review is dedicated to Mary Lyon, who passed away last year. She predicted many of the features of X inactivation, for e.g., the existence of an X ...

  4. Bacteria, mould and yeast spore inactivation studies by scanning electron microscope observations.

    Science.gov (United States)

    Rozali, Siti N M; Milani, Elham A; Deed, Rebecca C; Silva, Filipa V M

    2017-12-18

    Spores are the most resistant form of microbial cells, thus difficult to inactivate. The pathogenic or food spoilage effects of certain spore-forming microorganisms have been the primary basis of sterilization and pasteurization processes. Thermal sterilization is the most common method to inactivate spores present on medical equipment and foods. High pressure processing (HPP) is an emerging and commercial non-thermal food pasteurization technique. Although previous studies demonstrated the effectiveness of thermal and non-thermal spore inactivation, the in-depth mechanisms of spore inactivation are as yet unclear. Live and dead forms of two food spoilage bacteria, a mould and a yeast were examined using scanning electron microscopy before and after the inactivation treatment. Alicyclobacillus acidoterrestris and Geobacillus stearothermophilus bacteria are indicators of acidic foods pasteurization and sterilization processes, respectively. Neosartorya fischeri is a phyto-pathogenic mould attacking fruits. Saccharomyces cerevisiae is a yeast with various applications for winemaking, brewing, baking and the production of biofuel from crops (e.g. sugar cane). Spores of the four microbial species were thermally inactivated. Spores of S. cerevisiae were observed in the ascus and free form after thermal and HPP treatments. Different forms of damage and cell destruction were observed for each microbial spore. Thermal treatment inactivated bacterial spores of A. acidoterrestris and G. stearothermophilus by attacking the inner core of the spore. The heat first altered the membrane permeability allowing the release of intracellular components. Subsequently, hydration of spores, physicochemical modifications of proteins, flattening and formation of indentations occurred, with subsequent spore death. Regarding N. fischeri, thermal inactivation caused cell destruction and leakage of intracellular components. Both thermal and HPP treatments of S. cerevisiae free spores attacked

  5. Photodynamic inactivation of mammalian viruses and bacteriophages.

    Science.gov (United States)

    Costa, Liliana; Faustino, Maria Amparo F; Neves, Maria Graça P M S; Cunha, Angela; Almeida, Adelaide

    2012-07-01

    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.

  6. Photodynamic Inactivation of Mammalian Viruses and Bacteriophages

    Science.gov (United States)

    Costa, Liliana; Faustino, Maria Amparo F.; Neves, Maria Graça P. M. S.; Cunha, Ângela; Almeida, Adelaide

    2012-01-01

    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. PMID:22852040

  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. 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.

  9. Solar radiation disinfection of drinking water at temperate latitudes: inactivation rates for an optimised reactor configuration.

    Science.gov (United States)

    Davies, C M; Roser, D J; Feitz, A J; Ashbolt, N J

    2009-02-01

    Solar radiation-driven inactivation of bacteria, virus and protozoan pathogen models was quantified in simulated drinking water at a temperate latitude (34 degrees S). The water was seeded with Enterococcus faecalis, Clostridium sporogenes spores, and P22 bacteriophage, each at ca 1x10(5) mL(-1), and exposed to natural sunlight in 30-L reaction vessels. Water temperature ranged from 17 to 39 degrees C during the experiments lasting up to 6h. Dark controls showed little inactivation and so it was concluded that the inactivation observed was primarily driven by non-thermal processes. The optimised reactor design achieved S90 values (cumulative exposure required for 90% reduction) for the test microorganisms in the range 0.63-1.82 MJ m(-2) of Global Solar Exposure (GSX) without the need for TiO2 as a catalyst. High turbidity (840-920 NTU) only reduced the S(90) value by 0.05). However, inactivation was significantly reduced for E. faecalis and P22 when the transmittance of UV wavelengths was attenuated by water with high colour (140 PtCo units) or a suboptimally transparent reactor lid (prob.SODIS type pasteurization were not produced, non-thermal inactivation alone appeared to offer a viable means for reliably disinfecting low colour source waters by greater than 4 orders of magnitude on sunny days at 34 degrees S latitude.

  10. Modeling the inactivation of ascaris eggs as a function of ammonia concentration and temperature.

    Science.gov (United States)

    Fidjeland, J; Nordin, A; Pecson, B M; Nelson, K L; Vinnerås, B

    2015-10-15

    Ammonia sanitization is a promising technology for sanitizing human excreta intended for use as a fertilizer in agriculture. Ascaris eggs are the most persistent pathogens regarding ammonia inactivation and are commonly present in fecal sludge in low- and middle-income countries. In this study, a model for predicting ammonia inactivation of ascaris eggs was developed. Data from four previous studies were compiled and analyzed statistically, and a mathematical model for the treatment time required for inactivation was created. The inactivation rate increased with NH3 activity to the power of 0.7. The required treatment time was found to decrease 10-fold for each 16 °C temperature increase. Dry matter (DM) content and pH had no direct effect on inactivation, but had an indirect effect due to their impact on NH3 activity, which was estimated using the Pitzer approach. An additional model giving an approximation of Pitzer NH3 activity but based on the Emerson approach, DM content and total ammonia (NHTot) was also developed. The treatment time required for different log10 reductions of ascaris egg viability can thus easily be estimated by the model as a function of NH3 activity and temperature. The impact on treatment time by different treatment options can then be theoretically evaluated, promoting improvements of the treatment e.g. by adding urea or alkaline agents, or increasing the temperature by solar heating. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. An alternative approach for evaluating the phenotypic virulence factors of pathogenic Escherichia coli

    Directory of Open Access Journals (Sweden)

    Kamelia M. Osman

    2018-02-01

    Full Text Available Escherichia coli is a recognized zoonotic food-borne pathogen; however, the use of polymerase chain reaction (PCR in the underdeveloped countries to differentiate pathogenic from non-pathogenic E. coli is a problematic issue. Our grail was to assess the phenotypic virulence markers motility, hemolysin, congo red agar, embryo lethality assay and serum resistance for pathogenic E. coli (PEC correlated to PCR tests which is currently used world-wide to evaluate the PEC. The 448 strains of Escherichia coli that were isolated from different sources, were characterized for phenotypic virulence factors such as motility, hemolysin, Congo red binding, Embryo Lethality assay (ELA and serum resistance, as well as antibiotic susceptibility using disc diffusion method to 23 antibiotics. Results exhibited 100% motility and Congo red binding, 97.1% for hemolysin production and 90.2% in the ELA. As a result, we were able to hypothetically conclude that the aforementioned virulence markers are plain, straightforward, economical, rapid, more dynamic, uncomplicated methodology, duplicatable and cost next to nothing when compared to the molecular PCR. Their implementation in a diagnostic microbiology laboratory for vetting is a rewarding task in the underdeveloped countries. It augments endeavors to minimize the use of PCR in our investigations especially during epidemiological and outbreak investigations of PEC.

  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. Human pathogens in plant biofilms: Formation, physiology, and detection.

    Science.gov (United States)

    Ximenes, Eduardo; Hoagland, Lori; Ku, Seockmo; Li, Xuan; Ladisch, Michael

    2017-07-01

    Fresh produce, viewed as an essential part of a healthy life style is usually consumed in the form of raw or minimally processed fruits and vegetables, and is a potentially important source of food-borne human pathogenic bacteria and viruses. These are passed on to the consumer since the bacteria can form biofilms or otherwise populate plant tissues, thereby using plants as vectors to infect animal hosts. The life cycle of the bacteria in plants differs from those in animals or humans and results in altered physiochemical and biological properties (e.g., physiology, immunity, native microflora, physical barriers, mobility, and temperature). Mechanisms by which healthy plants may become contaminated by microorganisms, develop biofilms, and then pass on their pathogenic burden to people are explored in the context of hollow fiber microfiltration by which plant-derived microorganisms may be recovered and rapidly concentrated to facilitate study of their properties. Enzymes, when added to macerated plant tissues, hydrolyze or alter macromolecules that would otherwise foul hollow-fiber microfiltration membranes. Hence, microfiltration may be used to quickly increase the concentration of microorganisms to detectable levels. This review discusses microbial colonization of vegetables, formation and properties of biofilms, and how hollow fiber microfiltration may be used to concentrate microbial targets to detectable levels. The use of added enzymes helps to disintegrate biofilms and minimize hollow fiber membrane fouling, thereby providing a new tool for more time effectively elucidating mechanisms by which biofilms develop and plant tissue becomes contaminated with human pathogens. Biotechnol. Bioeng. 2017;114: 1403-1418. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. N'-formylkynurenine-photosensitized inactivation of bacteriophage

    International Nuclear Information System (INIS)

    Walrant, P.; Santus, R.; Redpath, J.L.; Pileni, M.P.

    1976-01-01

    Measurements have been made of the sensitizing properties of N'-formylkynurenine (FK) on bacteriophages, as part of a wider study of FK photosensitization of systems which have both protein and DNA components. Suspensions of bacteriophages T 6 and T 7 were near-U.V. (lambda > 320 nm) irradiated in solutions saturated with either O 2 or He in the presence of 5 x 10 -4 M FK. The survival curves obtained demonstrated that FK can act as a photosensitizer for biological inactivation. The involvement of singlet oxygen as one factor in this FK sensitized inactivation was clearly demonstrated by the increased rate of inactivation when the phage were suspended in O 2 -saturated D 2 O, in place of water, during irradiation. The complex mechanism of phage inactivation must involve direct interaction between excited FK and substrate, as well as singlet oxygen. FK is therefore a new natural photosensitizer of significance in cell photochemistry induced by sunlight. (U.K.)

  20. 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.

  1. 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.

  2. 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

  3. In vitro and in vivo examination of anticolonization of pathogens by Lactobacillus paracasei FJ861111.1.

    Science.gov (United States)

    Deng, Kan; Chen, Tingtao; Wu, Qinglong; Xin, Hongbo; Wei, Qiang; Hu, Ping; Wang, Xiaolei; Wang, Xin; Wei, Hua; Shah, Nagendra P

    2015-10-01

    Very limited information exists on the exclusion of pathogens by probiotics in the gut of the host challenged with pathogens. In this study, we tested probiotic characteristics in vitro and anticolonization ability of Lactobacillus paracasei FJ861111.1 in mice infected with selected pathogenic microorganisms. The in vitro results indicated that L. paracasei FJ861111.1 had a high survival in acidic conditions at pH 2.5 and bile salt concentration at 0.3%, and strong inhibition ability against common pathogens including Shigella dysenteriae, Staphylococcus aureus, Cronobacter sakazakii, Escherichia coli, and Candida albicans. The cell adhesion assays showed that L. paracasei FJ861111.1 exhibited strong adherence to HT-29 cells and excluded the adhesion of selected food-borne pathogens to HT-29 cells. The in vivo results showed that fermented milk with L. paracasei and viili (a Nordic yogurt product) significantly improved the population of total bacteria and of Lactobacillus in the feces of mice, and significantly inhibited the colonization of C. albicans to the intestines of mice post-C. albicans infection. Thus, it appears that this strain could be used as a probiotic organism for manufacturing functional fermented milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. 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

  5. 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.

  6. Methods for the Control of Foodborne Pathogens in Low-Moisture Foods.

    Science.gov (United States)

    Sánchez-Maldonado, Alma Fernanda; Lee, Alvin; Farber, Jeffrey M

    2018-03-25

    Low-moisture foods (LMFs) have been defined as those food products with a water activity (a w ) less than 0.85 and are generally considered less susceptible to microbial spoilage and the growth of foodborne pathogens. However, in recent years, outbreaks linked to LMFs have increased, with Salmonella spp., Bacillus cereus, Cronobacter sakazakii, Clostridium spp., Escherichia coli O157:H7, non-O157 E. coli, and Staphylococcus aureus being the principal pathogens involved. Because of the new concerns raised as a result of recent outbreaks, new approaches need to be developed to control foodborne pathogens in LMFs. This review summarizes the recent research on novel inactivation methods suitable for use on LMFs. Among the methods discussed are the nonthermal inactivation methods as well as other novel methods such as radio-frequency and microwave heating. Additional research is needed to evaluate older technologies and develop new technologies, either alone or in combination, to understand the mechanisms of inactivation.

  7. 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...

  8. Survival of pathogenic and lactobacilli species of fermented olives during simulated human digestion

    Directory of Open Access Journals (Sweden)

    Francisco Noé eArroyo López

    2014-10-01

    Full Text Available The present survey uses a dynamic gastric and small intestinal model to assess the survival of one pathogenic (Escherichia coli O157:H7 EDL 933 and three lactobacilli bacteria with probiotic potential (Lactobacillus rhamnosus GG, Lactobacillus pentosus TOMC-LAB2 and Lactobacillus pentosus TOMC-LAB4 during their passage through the human gastrointestinal tract using fermented olives as the food matrix. The data showed that the survival of the E. coli strain in the stomach and duodenum was very low, while its transit through the distal parts (jejunum and ileum resulted in an increase in the pathogen population. The production of Shiga toxins by this enterohemorrhagic microorganism in the ileal effluents of the in vitro system was too low to be detected by ELISA assays. On the contrary, the three lactobacilli species assayed showed a considerable resistance to the gastric digestion, but not to the intestinal one, which affected their survival, and was especially evident in the case of both L. pentosus strains. In spite of this, high population levels for all assayed microorganisms were recovered at the end of the gastrointestinal passage. The results obtained in the present study show the potential use of table olives as a vehicle of beneficial microorganisms to the human body, as well as the need for good hygienic practices on the part of olive manufacturers in order to avoid the possibility of contamination by food-borne pathogens.

  9. Survival of pathogenic and lactobacilli species of fermented olives during simulated human digestion.

    Science.gov (United States)

    Arroyo-López, Francisco N; Blanquet-Diot, Stéphanie; Denis, Sylvain; Thévenot, Jonathan; Chalancon, Sandrine; Alric, Monique; Rodríguez-Gómez, Francisco; Romero-Gil, Verónica; Jiménez-Díaz, Rufino; Garrido-Fernández, Antonio

    2014-01-01

    The present survey uses a dynamic gastric and small intestinal model to assess the survival of one pathogenic (Escherichia coli O157:H7 EDL 933) and three lactobacilli bacteria with probiotic potential (Lactobacillus rhamnosus GG, L. pentosus TOMC-LAB2, and L. pentosus TOMC-LAB4) during their passage through the human gastrointestinal tract using fermented olives as the food matrix. The data showed that the survival of the E. coli strain in the stomach and duodenum was very low, while its transit through the distal parts (jejunum and ileum) resulted in an increase in the pathogen population. The production of Shiga toxins by this enterohemorrhagic microorganism in the ileal effluents of the in vitro system was too low to be detected by ELISA assays. On the contrary, the three lactobacilli species assayed showed a considerable resistance to the gastric digestion, but not to the intestinal one, which affected their survival, and was especially evident in the case of both L. pentosus strains. In spite of this, high population levels for all assayed microorganisms were recovered at the end of the gastrointestinal passage. The results obtained in the present study show the potential use of table olives as a vehicle of beneficial microorganisms to the human body, as well as the need for good hygienic practices on the part of olive manufacturers in order to avoid the possibility of contamination by food-borne pathogens.

  10. Analysis of acid-stressed Bacillus cereus reveals a major oxidative response and inactivation-associated radical formation.

    Science.gov (United States)

    Mols, Maarten; van Kranenburg, Richard; van Melis, Clint C J; Moezelaar, Roy; Abee, Tjakko

    2010-04-01

    Acid stress resistance of the food-borne human pathogen Bacillus cereus may contribute to its survival in acidic environments, such as encountered in soil, food and the human gastrointestinal tract. The acid stress responses of B. cereus strains ATCC 14579 and ATCC 10987 were analysed in aerobically grown cultures acidified to pH values ranging from pH 5.4 to pH 4.4 with HCl. Comparative phenotype and transcriptome analyses revealed three acid stress-induced responses in this pH range: growth rate reduction, growth arrest and loss of viability. These physiological responses showed to be associated with metabolic shifts and the induction of general stress response mechanisms with a major oxidative component, including upregulation of catalases and superoxide dismutases. Flow cytometry analysis in combination with the hydroxyl (OH.) and peroxynitrite (ONOO(-))-specific fluorescent probe 3'-(p-hydroxyphenyl) fluorescein (HPF) showed excessive radicals to be formed in both B. cereus strains in bactericidal conditions only. Our study shows that radicals can indicate acid-induced malfunctioning of cellular processes that lead to cell death.

  11. Susceptibility of pathogenic and nonpathogenic Naegleria ssp

    Energy Technology Data Exchange (ETDEWEB)

    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 {sup 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 {sup 125}I radiolabeled C9 indicated that the terminal complement component does not remain stably bound to the membrane of pathogenic amoebae.

  12. 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.

  13. Immunologic evaluation of 10 different adjuvants for use in vaccines for chickens against highly pathogenic avian influenza virus

    Science.gov (United States)

    Avian influenza viruses (AIV) are a threat to poultry production worldwide. Vaccination is utilized as a component of control programs for both high pathogenicity (HP) and low pathogenicity (LP) AIV. Over 95% of all AIV vaccine used in poultry are inactivated, adjuvanted products. To identify the be...

  14. 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...

  15. Campylobacter jejuni : An emerging pathogen

    Directory of Open Access Journals (Sweden)

    Nathanon Trachoo

    2003-01-01

    Full Text Available Campylobacter jejuni is a major cause of food-borne diarrhea in many countries. However, in some countries, a number of cases were undetected because of the inappropriate detection method and ignorance. Although C. jejuni usually does not cause death in health adults, it can be deadly for immunocompromised persons (Pigrau, et al., 1997. Although thought to be very susceptible in several conditions, C. jejuni in fact is quite prevalent in nature. It can easily cause sporadic cases and outbreaks resulting in economic loss. This review covers three major parts: clinical aspects of Campylobacteriosis, C. jejuni reservoirs and transmission, and methods for detection.

  16. Photodynamic biofilm inactivation by SAPYR--an exclusive singlet oxygen photosensitizer.

    Science.gov (United States)

    Cieplik, Fabian; Späth, Andreas; Regensburger, Johannes; Gollmer, Anita; Tabenski, Laura; Hiller, Karl-Anton; Bäumler, Wolfgang; Maisch, Tim; Schmalz, Gottfried

    2013-12-01

    Prevention and control of biofilm-growing microorganisms are serious problems in public health due to increasing resistances of some pathogens against antimicrobial drugs and the potential of these microorganisms to cause severe infections in patients. Therefore, alternative approaches that are capable of killing pathogens are needed to supplement standard treatment modalities. One alternative is the photodynamic inactivation of bacteria (PIB). The lethal effect of PIB is based on the principle that visible light activates a photosensitizer, leading to the formation of reactive oxygen species, e.g., singlet oxygen, which induces phototoxicity immediately during illumination. SAPYR is a new generation of photosensitizers. Based on a 7-perinaphthenone structure, it shows a singlet oxygen quantum yield ΦΔ of 99% and is water soluble and photostable. Moreover, it contains a positive charge for good adherence to cell walls of pathogens. In this study, the PIB properties of SAPYR were investigated against monospecies and polyspecies biofilms formed in vitro by oral key pathogens. SAPYR showed a dual mechanism of action against biofilms: (I) it disrupts the structure of the biofilm even without illumination; (II) when irradiated, it inactivates bacteria in a polymicrobial biofilm after one single treatment with an efficacy of ≥ 99.99%. These results encourage further investigation on the potential of PIB using SAPYR for the treatment of localized infectious diseases. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  17. 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.

  18. Advances in antimicrobial photodynamic inactivation at the nanoscale

    Directory of Open Access Journals (Sweden)

    Kashef Nasim

    2017-08-01

    Full Text Available 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.

  19. 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.

  20. Ammonia as an In Situ Sanitizer: Influence of Virus Genome Type on Inactivation.

    Science.gov (United States)

    Decrey, Loïc; Kazama, Shinobu; Kohn, Tamar

    2016-08-15

    Treatment of human excreta and animal manure (HEAM) is key in controlling the spread of persistent enteric pathogens, such as viruses. The extent of virus inactivation during HEAM storage and treatment appears to vary with virus genome type, although the reasons for this variability are not clear. Here, we investigated the inactivation of viruses of different genome types under conditions representative of HEAM storage or mesophilic digestion. The goals were to characterize the influence of HEAM solution conditions on inactivation and to determine the potential mechanisms involved. Specifically, eight viruses representing the four viral genome types (single-stranded RNA [ssRNA], double-stranded RNA [dsRNA], single-stranded DNA [ssDNA], and double-stranded DNA [dsDNA]) were exposed to synthetic solutions with well-controlled temperature (20 to 35°C), pH (8 to 9), and ammonia (NH3) concentrations (0 to 40 mmol liter(-1)). DNA and dsRNA viruses were considerably more resistant than ssRNA viruses, resulting in up to 1,000-fold-longer treatment times to reach a 4-log inactivation. The apparently slower inactivation of DNA viruses was rationalized by the higher stability of DNA than that of ssRNA in HEAM. Pushing the system toward harsher pH (>9) and temperature (>35°C) conditions, such as those encountered in thermophilic digestion and alkaline treatments, led to more consistent inactivation kinetics among ssRNA and other viruses. This suggests that the dependence of inactivation on genome type disappeared in favor of protein-mediated inactivation mechanisms common to all viruses. Finally, we recommend the use of MS2 as a conservative indicator to assess the inactivation of ssRNA viruses and the stable ΦX174 or dsDNA phages as indicators for persistent viruses. Viruses are among the most environmentally persistent pathogens. They can be present in high concentrations in human excreta and animal manure (HEAM). Therefore, appropriate treatment of HEAM is important

  1. Effectiveness of ultrasound, UV-C, and photocatalysis on inactivation kinetics of Aeromonas hydrophila.

    Science.gov (United States)

    Kaur, Jasjeet; Karthikeyan, Raghupathy; Pillai, Suresh D

    2015-01-01

    In this study, bactericidal effects of 24 kHz ultrasound, ultraviolet (UV-C) irradiation, and titanium dioxide (TiO2) photocatalyst were studied on inactivation of Aeromonas hydrophila, an emerging pathogen listed on the US Environmental Protection Agency's (US EPA) candidate contaminant list. Metabolic activity (using the AlamarBlue dye) assays were performed to assess the residual activity of the microbial cells after the disinfection treatments along with culture-based methods. A faster inactivation rate of 1.52 log min(-1) and inactivation of 7.62 log10 was observed within 5 min of ultrasound exposure. Ultrasound treated cells repaired by 1.4 log10 in contrast to 5.3 log10 repair for UV-C treated cells. Ultrasound treatment significantly lowered the reactivation of Aeromonas hydrophila in comparison to UV-C- and UV-C-induced photocatalysis. Ultrasound appeared to be an effective means of inactivating Aeromonas hydrophila and could be used as a potential disinfection method for water and wastewater reuse.

  2. 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.

  3. Vitamin K5 is an efficient photosensitizer for ultraviolet A light inactivation of bacteria.

    Science.gov (United States)

    Xu, Fei; Li, Ying; Ahmad, Justen; Wang, Yonggang; Scott, Dorothy E; Vostal, Jaroslav G

    2018-02-01

    Photodynamic treatment combining light and a photosensitizer molecule can be an effective method to inactivate pathogenic bacteria. This study identified vitamin K5 as an efficient photosensitizer for ultraviolet light A (UVA)-induced bacterial inactivation. Six bacterial species, Bacillus cereus (vegetative form), Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, and two species of antibiotic-resistant bacteria, Pseudomonas aeruginosa* and Staphylococcus aureus*, were suspended in aqueous solutions with or without vitamin K5 and exposed to UVA irradiation. UVA irradiation (5.8 J cm-2) with vitamin K5 (1600 μmol l-1) reduced the colony forming units (CFU) of these bacteria by three to seven logs. Antibiotic resistant bacteria were also susceptible to the bactericidal effects of UVA and vitamin K5 combination treatment. Inactivation of bacteria in human plasma required higher doses of UVA light and vitamin K5. UVA irradiation (30 J cm-2) with vitamin K5 (2000 μmol l-1) reduced E. coli and S. aureus spiked into human plasma by seven logs CFU/ml. Reactive oxygen species, such as superoxide anion radicals and hydroxyl radicals, were found to be generated in vitamin K5 aqueous solution after UVA irradiation, suggesting these oxygen species may mediate the inactivation of the bacteria. Published by Oxford University Press on behalf of FEMS 2018.

  4. Preliminary molecular characterization of the human pathogen Angiostrongylus cantonensis

    Directory of Open Access Journals (Sweden)

    He Ai

    2009-10-01

    Full Text Available Abstract Background Human angiostrongyliasis is an emerging food-borne public health problem, with the number of cases increasing worldwide, especially in mainland China. Angiostrongylus cantonensis is the causative agent of this severe disease. However, little is known about the genetics and basic biology of A. cantonensis. Results A cDNA library of A. cantonensis fourth-stage larvae was constructed, and ~1,200 clones were sequenced. Bioinformatic analyses revealed 378 cDNA clusters, 54.2% of which matched known genes at a cutoff expectation value of 10-20. Of these 378 unique cDNAs, 168 contained open reading frames encoding proteins containing an average of 238 amino acids. Characterization of the functions of these encoded proteins by Gene Ontology analysis showed enrichment in proteins with binding and catalytic activity. The observed pattern of enzymes involved in protein metabolism, lipid metabolism and glycolysis may reflect the central nervous system habitat of this pathogen. Four proteins were tested for their immunogenicity using enzyme-linked immunosorbent assays and histopathological examinations. The specificity of each of the four proteins was superior to that of crude somatic and excretory/secretory antigens of larvae, although their sensitivity was relatively low. We further showed that mice immunized with recombinant cystatin, a product of one of the four cDNA candidate genes, were partially protected from A. cantonensis infection. Conclusion The data presented here substantially expand the available genetic information about the human pathogen A. cantonensis, and should be a significant resource for angiostrongyliasis researchers. As such, this work serves as a starting point for molecular approaches for diagnosing and controlling human angiostrongyliasis.

  5. Inactivation of Escherichia coli O157:H7 and Salmonella during washing of contaminated gloves in levulinic acid and sodium dodecyl sulfate solutions.

    Science.gov (United States)

    Erickson, Marilyn C; Liao, Jye-Yin; Habteselassie, Mussie Y; Cannon, Jennifer L

    2018-08-01

    Field workers often wear gloves harvesting ready-to-eat produce; however, fields are not sterile environments and gloves may become contaminated numerous times during a working shift. This study explored the potential for inactivation of Escherichia coli O157:H7 and Salmonella when contaminated gloves were washed in levulinic acid (LV) and sodium dodecyl sulfate (SDS) solutions. Washing nitrile gloves with increasing concentrations of LV above 1.0% led to a decreased prevalence of glove contamination by Salmonella (P = 0.0000). A higher level of prevalence occurred for solid agar-cultured pathogens than liquid broth-cultured pathogens after nitrile gloves were washed in LV/SDS (P = 0.0000). Pathogens residing on latex gloves were more likely to be completely inactivated by washing in 0.5% LV/0.1% SDS solutions than nitrile or Canners gloves that exhibited inconsistent responses dependent on the pathogen strain. However, drying after washing nitrile gloves in 0.5% LV/0.1% SDS led to additional pathogen inactivation (P = 0.0394). Pathogen transfer from gloves to produce was implied as the pathogen prevalence on cantaloupe rind handled by LV/SDS-washed gloves was not statistically different from the prevalence on gloves (P = 0.7141). Hence, the risk of produce contamination may still exist but would be reduced by washing gloves in LV/SDS. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Effect of virulence factors on the photodynamic inactivation of Cryptococcus neoformans.

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    Renato A Prates

    Full Text Available Opportunistic fungal pathogens may cause an array of superficial infections or serious invasive infections, especially in immunocompromised patients. Cryptococcus neoformans is a pathogen causing cryptococcosis in HIV/AIDS patients, but treatment is limited due to the relative lack of potent antifungal agents. Photodynamic inactivation (PDI uses the combination of non-toxic dyes called photosensitizers and harmless visible light, which produces singlet oxygen and other reactive oxygen species that produce cell inactivation and death. We report the use of five structurally unrelated photosensitizers (methylene blue, Rose Bengal, selenium derivative of a Nile blue dye, a cationic fullerene and a conjugate between poly-L-lysine and chlorin(e6 combined with appropriate wavelengths of light to inactivate C. neoformans. Mutants lacking capsule and laccase, and culture conditions that favoured melanin production were used to probe the mechanisms of PDI and the effect of virulence factors. The presence of cell wall, laccase and melanin tended to protect against PDI, but the choice of the appropriate photosensitizers and dosimetry was able to overcome this resistance.

  7. Inactivation of bacterial and viral biothreat agents on metallic copper surfaces.

    Science.gov (United States)

    Bleichert, Pauline; Espírito Santo, Christophe; Hanczaruk, Matthias; Meyer, Hermann; Grass, Gregor

    2014-12-01

    In recent years several studies in laboratory settings and in hospital environments have demonstrated that surfaces of massive metallic copper have intrinsic antibacterial and antiviral properties. Microbes are rapidly inactivated by a quick, sharp shock known as contact killing. The underlying mechanism is not yet fully understood; however, in this process the cytoplasmic membrane is severely damaged. Pathogenic bacterial and viral high-consequence species able to evade the host immune system are among the most serious lethal microbial challenges to human health. Here, we investigated contact-killing mediated by copper surfaces of Gram-negative bacteria (Brucella melitensis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis tularensis and Yersinia pestis) and of Gram-positive endospore-forming Bacillus anthracis. Additionally, we also tested inactivation of monkeypox virus and vaccinia virus on copper. This group of pathogens comprises biothreat species (or their close relatives) classified by the Center for Disease and Control and Prevention (CDC) as microbial select agents posing severe threats to public health and having the potential to be deliberately released. All agents were rapidly inactivated on copper between 30 s and 5 min with the exception of B. anthracis endospores. For vegetative bacterial cells prolonged contact to metallic copper resulted in the destruction of cell structure.

  8. Methods for thermal inactivation of pathogens in mozzarella: a comparison between stretching and pasteurization Métodos para inativação térmica de patógenos em mozarela: comparação entre filagem e pasteurização

    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.Este estudo teve como objetivo avaliar a eficácia da filagem na redução de patógenos,em comparação coma pasteurizaçãodo leite, que é o método oficialpara garantir aprodução de queijos seguros. Leite de búfala integral foi contaminado com Mycobacterium fortuitum, Listeria monocytogenes, Salmonella typhimurium e Staphylococcus aureus. Parte desse leite foi empregada na fabricação da mozarela e outra parte foi submetida à pasteurização lenta. Os patógenosforam quantificadosantes e após os processos térmicos (filagem da mozarela e pasteurização do leite. As reduções, em ciclos logarítmicos, causadas pela pasteurização e pela filagem, respectivamente, foram: 4,0 e 6,3 de Mycobacterium sp., 6,0 e 8,4 de Listeria sp., >6,8 e 4,5 de Staphylococcus sp. e >8,2 e 7,5 de Salmonella sp.

  9. 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

  10. Two-Dimensional Microdischarge Jet Array in Air: Characterization and Inactivation of Virus

    Science.gov (United States)

    Nayak, Gaurav

    Cold atmospheric pressure plasmas (CAPs) have proven to be quite effective for surface disinfection, wound healing and even cancer treatment in recent years. One of the major societal challenges faced today is related to illness caused by food-borne bacteria and viruses, particularly in minimally processed, fresh or ready-to-eat foods. Gastroenteritis outbreaks, caused, for example, by the human Norovirus (NV) is a growing concern. Current used technologies seem not to be fully effective. In this work we focus on a possible solution based on CAP technology for surface disinfection. Many discharge sources have been studied for disinfection and the two major challenges faced are the use of expensive noble gases (Ar/He) by many plasma sources and the difficulty to scale up the plasma devices. The efficacies of these devices also vary for different plasma sources, making it difficult to compare results from different research groups. Also, the interaction of plasma with the biological matter is not understood well, particularly for virus. In this work, a two-dimensional array of micro dielectric barrier discharge is used to treat Feline Calicivirus (FCV), which is a surrogate for human Norovirus. The plasma source can be operated with an air flow rate (up to 94 standard liters per minute or slm). The use of such discharge source also raises important scientific questions which are addressed in this work. These questions include the effect of gas flow rate on discharge properties and the production of reactive species responsible for virus inactivation and the underlying inactivation mechanism. The plasma source is characterized via several diagnostic techniques such as current voltage measurements for electrical characterization and power measurements, optical emission spectroscopy (OES) to determine the gas temperature, cross-correlation spectroscopy (CCS) for microdischarge evolution and timescales, UV absorption spectroscopy to measure the O3 density, absolute IR

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

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    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.

  12. 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).

  13. Inactivation of viruses and bacteria in sewage sludge by gamma radiation

    International Nuclear Information System (INIS)

    Stettmund von Brodorotti, H.; Mahnel, H.

    1980-01-01

    The kinetics of inactivation and the resistance to gamma radiation of microorganisms usually to be found in raw sludge were examined with five viruses, three bacteria and a fungus serving as prototypes in comparative studies. All these infectious agents could reliably be inactivated by gamma rays in raw sewage sludge but they were dearly more resistant to gamma rays compared to irradiation in a liquid suspension. The reduction of the virus content required a much higher radiation dose compared to bacteria and the fungus used, excluding Streptococcus faecalis which was exceptionally resistant. Considering the content of pathogenic viruses and other agents in raw sewage sludge, the required radiation dose necessary to comply with average to strict demands for the hygienisation of sewage sludge is discussed. The radiation dose of 500 to 1,000 krad seems therefore to be sufficient. (orig.) [de

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

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    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.

  15. 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.

  16. Bioinactivation: Software for modelling dynamic microbial inactivation.

    Science.gov (United States)

    Garre, Alberto; Fernández, Pablo S; Lindqvist, Roland; Egea, Jose A

    2017-03-01

    This contribution presents the bioinactivation software, which implements functions for the modelling of isothermal and non-isothermal microbial inactivation. This software offers features such as user-friendliness, modelling of dynamic conditions, possibility to choose the fitting algorithm and generation of prediction intervals. The software is offered in two different formats: Bioinactivation core and Bioinactivation SE. Bioinactivation core is a package for the R programming language, which includes features for the generation of predictions and for the fitting of models to inactivation experiments using non-linear regression or a Markov Chain Monte Carlo algorithm (MCMC). The calculations are based on inactivation models common in academia and industry (Bigelow, Peleg, Mafart and Geeraerd). Bioinactivation SE supplies a user-friendly interface to selected functions of Bioinactivation core, namely the model fitting of non-isothermal experiments and the generation of prediction intervals. The capabilities of bioinactivation are presented in this paper through a case study, modelling the non-isothermal inactivation of Bacillus sporothermodurans. This study has provided a full characterization of the response of the bacteria to dynamic temperature conditions, including confidence intervals for the model parameters and a prediction interval of the survivor curve. We conclude that the MCMC algorithm produces a better characterization of the biological uncertainty and variability than non-linear regression. The bioinactivation software can be relevant to the food and pharmaceutical industry, as well as to regulatory agencies, as part of a (quantitative) microbial risk assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. 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

  18. 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...

  19. Inactivation of Bacillus atrophaeus by OH radicals

    Science.gov (United States)

    Ono, Ryo; Yonetamari, Kenta; Tokumitsu, Yusuke; Yonemori, Seiya; Yasuda, Hachiro; Mizuno, Akira

    2016-08-01

    The inactivation of Bacillus atrophaeus by OH radicals is measured. This study aims to evaluate the bactericidal effects of OH radicals produced by atmospheric-pressure nonthermal plasma widely used for plasma medicine; however, in this study, OH radicals are produced by vacuum ultraviolet (VUV) photolysis of water vapor instead of plasma to allow the production of OH radicals with almost no other reactive species. A 172 nm VUV light from a Xe2 excimer lamp irradiates a He-H2O mixture flowing in a quartz tube to photodissociate H2O to produce OH, H, O, HO2, H2O2, and O3. The produced reactive oxygen species (ROS) flow out of the quartz tube nozzle to the bacteria on an agar plate and cause inactivation. The inactivation by OH radicals among the six ROS is observed by properly setting the experimental conditions with the help of simulations calculating the ROS densities. A 30 s treatment with approximately 0.1 ppm OH radicals causes visible inactivation.

  20. 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.

  1. Inactivation of Bacillus Anthracis Spores Using Carbon Nanotubes

    Science.gov (United States)

    2014-10-30

    effect of SWNTs in combination with antimicrobial chemicals on inactivation of B. anthracis spores; 4) the effect of CNTs coated surfaces on the...2010 31-May-2014 Approved for Public Release; Distribution Unlimited Final Report: (Life Science Division/ Biochemistry ) Inactivation of Bacillus... Biochemistry ) Inactivation of Bacillus Anthracis Spores Using Carbon Nanotubes Report Title The Specific Aims of the project were to investigate: 1) the

  2. 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.

  3. Inactivation of Escherichia coli and Listeria innocua in apple and carrot juices using high pressure homogenization and nisin.

    Science.gov (United States)

    Pathanibul, Panchalee; Taylor, T Matthew; Davidson, P Michael; Harte, Federico

    2009-02-28

    High pressure homogenization has been of growing interest as a nonthermal technology for the inactivation of microorganisms in fruit and vegetable juices. Cells of Escherichia coli and Listeria innocua, used as surrogates for foodborne pathogens, were inoculated into apple or carrot juice (approximately 7 log(10) CFU/ml) containing 0 or 10 IU/ml nisin and subjected to 350 to 0 MPa high pressure homogenization. At 50 MPa homogenization pressure intervals, juice samples were collected, immediately cooled to 5 log reduction of cells was achieved following exposure to pressures in excess >250 MPa. In contrast, little inactivation was observed for L. innocua with pressure innocua. Results indicate that high pressure homogenization processing is a promising technology to achieve pathogen decontamination in fruit and vegetable juices.

  4. 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.

  5. Antimicrobial activity of Lactobacillus acidophilus against pathogenic and food spoilage microorganisms: A review

    Directory of Open Access Journals (Sweden)

    T. Dinev

    2017-03-01

    Full Text Available Abstract. The purpose of this review is to summarize the information regarding the antimicrobial activity of Lactobacillus acidophilus, an important species of lactic acid bacteria. Lactic acid bacteria are constituents of many beneficent for the consumer's health food products. They are considered potentially promising in the strategy to combat infections and prevent the growth of spoilage microorganisms, and also have antimutagenic, anticarcinogenic, hypolipidemic and hypocholesterolemic properties, improve the lactose metabolism, stimulate the immune system, etc. In the resent years Lactobacillus acidophilus is considered the main probiotic species in the intestinal tract of healthy humans and is widely used in functional dairy foods. It produces a variety of metabolic products with antimicrobial properties, including organic acids and bacteriocins, such as lactacins B and F, acidophilin, acidocin, acidophilucin, acidophilicin, which are active against many pathogenic and spoilage microorganisms - Escherichia coli (including Escherichi coli 0157:H7, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, Vibrio parahaemolyticus, Vibrio cholerae, Helicobacter pylori, Klebsiella, Salmonella, Shigella, Bacillus, Clostridium, Mucor, Aspergillus, Fusarium, Trichoderma and Candida spp., etc. Because of the above mentioned reasons Lactobacillus acidophilus could be used as an alternative therapeutic agent against infections caused by susceptible microorganisms. On the other hand Lactobacillus acidophilus based antimicrobial products (mainly bacteriocins and pure cultures could also be applied to food products to prevent the growth of spoilage microorganisms and food-borne pathogens. To better understand the mode of action and the spectrum of antifungal activity more clinical and laboratory studies of different Lactobacillus acidophilus strains are required.

  6. Potent Antagonistic Activity of Egyptian Lactobacillus plantarum against multiresistant and Virulent Food-associated Pathogens

    Directory of Open Access Journals (Sweden)

    Lamiaa eAl-Madboly

    2015-05-01

    Full Text Available Recent years have showed a growing interest to replace the administration of antibiotics with the application of probiotics. The aim of our investigation was to screen for promising strains with broad antimicrobial activity and also more resistant to the challenges met in the gastrointestinal tract. In our study, only 32 out of the 50 (64% probiotic isolates showed antagonistic activity against certain major extensively and pandrug-resistant Gram-positive and -negative food-borne pathogens. Fifteen L. plantarum isolates had a broad antibacterial spectrum. Among these isolates, only five presented potent antibacterial activity relative to previous studies. The recorded inhibition zone diameter ranged from 25 to 44 mm. Pronounced cell-free supernatant activities (6400-25600 AU/ml were commonly detected at the end of the logarithmic phase at 37°C. A marked increase in the range of activity (12800-51200 AU/ml was recorded after the addition of 0.9% NaCl to the media. Moreover, subjecting these isolates to different stressors, including high temperature, low pH, and different concentrations of bile and NaCl, revealed different responses, and only two out of the five L. plantarum isolates showed marked resistance to all of the stress factors. This study highlights the intense and broad antagonistic activity induced by L. plantarum against various food associated pathogens, and their ability to resist different stressors suggests that they can be used in the food and pharmaceutical industry.

  7. Obacunone Represses Salmonella Pathogenicity Islands 1 and 2 in an envZ-Dependent Fashion

    Science.gov (United States)

    Vikram, Amit; Jayaprakasha, Guddadarangavvanahally K.; Jesudhasan, Palmy R.

    2012-01-01

    Obacunone belongs to a class of unique triterpenoids called limonoids, present in Citrus species. Previous studies from our laboratory suggested that obacunone possesses antivirulence activity and demonstrates inhibition of cell-cell signaling in Vibrio harveyi and Escherichia coli O157:H7. The present work sought to determine the effect of obacunone on the food-borne pathogen Salmonella enterica serovar Typhimurium LT2 by using a cDNA microarray. Transcriptomic studies indicated that obacunone represses Salmonella pathogenicity island 1 (SPI1), the maltose transporter, and the hydrogenase operon. Furthermore, phenotypic data for the Caco-2 infection assay and maltose utilization were in agreement with microarray data suggesting repression of SPI1 and maltose transport. Further studies demonstrated that repression of SPI1 was plausibly mediated through hilA. Additionally, obacunone seems to repress SPI2 under SPI2-inducing conditions as well as in Caco-2 infection models. Furthermore, obacunone seems to repress hilA in an EnvZ-dependent fashion. Altogether, the results of the study seems to suggest that obacunone exerts an antivirulence effect on S. Typhimurium and may serve as a lead compound for development of antivirulence strategies for S. Typhimurium. PMID:22843534

  8. An antifungal role of hydrogen sulfide on the postharvest pathogens Aspergillus niger and Penicillium italicum.

    Directory of Open Access Journals (Sweden)

    Liu-Hui Fu

    Full Text Available In this research, the antifungal role of hydrogen sulfide (H2S on the postharvest pathogens Aspergillus niger and Penicillium italicum growing on fruits and under culture conditions on defined media was investigated. Our results show that H2S, released by sodium hydrosulfide (NaHS effectively reduced the postharvest decay of fruits induced by A. niger and P. italicum. Furthermore, H2S inhibited spore germination, germ tube elongation, mycelial growth, and produced abnormal mycelial contractions when the fungi were grown on defined media in Petri plates. Further studies showed that H2S could cause an increase in intracellular reactive oxygen species (ROS in A. niger. In accordance with this observation we show that enzyme activities and the expression of superoxide dismutase (SOD and catalase (CAT genes in A. niger treated with H2S were lower than those in control. Moreover, H2S also significantly inhibited the growth of Saccharomyces cerevisiae, Rhizopus oryzae, the human pathogen Candida albicans, and several food-borne bacteria. We also found that short time exposure of H2S showed a microbicidal role rather than just inhibiting the growth of microbes. Taken together, this study suggests the potential value of H2S in reducing postharvest loss and food spoilage caused by microbe propagation.

  9. Inactivation and sub-lethal injury of salmonella typhi, salmonella typhimurium and vibrio cholerae in copper water storage vessels

    Directory of Open Access Journals (Sweden)

    Reed Robert H

    2011-07-01

    Full Text Available Abstract Background This study provides information on the antibacterial effect of copper against the water-borne pathogens Salmonella Typhi, Salmonella Typhimurium and Vibrio cholerae. Methods Suspensions of each pathogen were kept in water within a traditional copper vessel at 30°C for 24 h. Samples were withdrawn, diluted and plated onto suitable growth media. Conventional enumeration of healthy (uninjured bacteria was carried out using standard aerobic incubation conditions. Additionally, reactive oxygen species-neutralised (ROS-n conditions were achieved by adding the peroxide scavenger sodium pyruvate to the medium with anaerobic incubation, to enumerate uninjured (ROS-insensitive and injured (ROS-sensitive bacteria. Differences between log-transformed means of conventional (aerobic and ROS-n counts were statistically evaluated using t tests. Results Overall, all three pathogens were inactivated by storage in copper vessels for 24 h. However, for shorter-term incubation (4-12 h, higher counts were observed under ROS-n conditions than under aerobic conditions, which demonstrate the presence of substantial numbers of sub-lethally injured cells prior to their complete inactivation. Conclusions The present study has for the first time confirmed that these bacterial pathogens are inactivated by storage in a copper vessel within 24 h. However, it has also demonstrated that it is necessary to account for short-term sub-lethal injury, manifest as ROS-sensitivity, in order to more fully understand the process. This has important practical implications in terms of the time required to store water within a copper vessel to completely inactivate these bacteria and thereby remove the risk of water-borne disease transmission by this route.

  10. Tracking Human Adenovirus Inactivation by Gamma Radiation under Different Environmental Conditions

    Science.gov (United States)

    Pimenta, Andreia I.; Guerreiro, Duarte; Madureira, Joana; Margaça, Fernanda M. A.

    2016-01-01

    this study are to provide new insights on the inactivation of enteric virus by gamma irradiation and to introduce new concepts and reinforce the benefits and utility of radiation technologies as disinfection processes. This may be an effective tool to guarantee the reduction of viral pathogens and to contribute to public health and sustainable water supplies. PMID:27316961

  11. Kinetics of Inactivation of Bacillus subtilis subsp. niger Spores and Staphylococcus albus on Paper by Chlorine Dioxide Gas in an Enclosed Space.

    Science.gov (United States)

    Wang, Tao; Wu, Jinhui; Qi, Jiancheng; Hao, Limei; Yi, Ying; Zhang, Zongxing

    2016-05-15

    Bacillus subtilis subsp. niger spore and Staphylococcus albus are typical biological indicators for the inactivation of airborne pathogens. The present study characterized and compared the behaviors of B. subtilis subsp. niger spores and S. albus in regard to inactivation by chlorine dioxide (ClO2) gas under different gas concentrations and relative humidity (RH) conditions. The inactivation kinetics under different ClO2 gas concentrations (1 to 5 mg/liter) were determined by first-order and Weibull models. A new model (the Weibull-H model) was established to reveal the inactivation tendency and kinetics for ClO2 gas under different RH conditions (30 to 90%). The results showed that both the gas concentration and RH were significantly (P 70%). Compared with the first-order model, the Weibull and Weibull-H models demonstrated a better fit for the experimental data, indicating nonlinear inactivation behaviors of the vegetative bacteria and spores following exposure to ClO2 gas. The times to achieve a six-log reduction of B. subtilis subsp. niger spore and S. albus were calculated based on the established models. Clarifying the kinetics of inactivation of B. subtilis subsp. niger spores and S. albus by ClO2 gas will allow the development of ClO2 gas treatments that provide an effective disinfection method. Chlorine dioxide (ClO2) gas is a novel and effective fumigation agent with strong oxidization ability and a broad biocidal spectrum. The antimicrobial efficacy of ClO2 gas has been evaluated in many previous studies. However, there are presently no published models that can be used to describe the kinetics of inactivation of airborne pathogens by ClO2 gas under different gas concentrations and RH conditions. The first-order and Weibull (Weibull-H) models established in this study can characterize and compare the behaviors of Bacillus subtilis subsp. niger spores and Staphylococcus albus in regard to inactivation by ClO2 gas, determine the kinetics of inactivation of

  12. Pathogen-Reduced, Extended Platelet Storage in Platelet Additive Solution (PAS)

    Science.gov (United States)

    2016-10-01

    transfusion. Our project proposes to determine the efficacy of using a pathogen inactivation technique (Mirasol) coupled with a platelet additive solution...apheresis platelet collection and drawing blood samples. • Subjects of child-bearing potential (either male or female) must agree to use an effective

  13. Structural and functional characterization of an arylamine N-acetyltransferase from the pathogen Mycobacterium abscessus

    DEFF Research Database (Denmark)

    Cocaign, Angélique; Kubiak, Xavier Jean Philippe; Xu, Ximing

    2014-01-01

    Mycobacterium abscessus is the most pathogenic rapid-growing mycobacterium and is one of the most resistant organisms to chemotherapeutic agents. However, structural and functional studies of M. abscessus proteins that could modify/inactivate antibiotics remain nonexistent. Here, the structural...

  14. 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

  15. 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 ...

  16. Optical Imaging of Paramagnetic Bead-DNA Aggregation Inhibition Allows for Low Copy Number Detection of Infectious Pathogens.

    Directory of Open Access Journals (Sweden)

    Jacquelyn A DuVall

    Full Text Available DNA-paramagnetic silica bead aggregation in a rotating magnetic field facilitates the quantification of DNA with femtogram sensitivity, but yields no sequence-specific information. Here we provide an original description of aggregation inhibition for the detection of DNA and RNA in a sequence-specific manner following loop-mediated isothermal amplification (LAMP. The fragments generated via LAMP fail to induce chaotrope-mediated bead aggregation; however, due to their ability to passivate the bead surface, they effectively inhibit bead aggregation by longer 'trigger' DNA. We demonstrate the utility of aggregation inhibition as a method for the detection of bacterial and viral pathogens with sensitivity that approaches single copies of the target. We successfully use this methodology for the detection of notable food-borne pathogens Escherichia coli O157:H7 and Salmonella enterica, as well as Rift Valley fever virus, a weaponizable virus of national security concern. We also show the concentration dependence of aggregation inhibition, suggesting the potential for quantification of target nucleic acid in clinical and environmental samples. Lastly, we demonstrate the ability to rapidly detect infectious pathogens by utilizing a cell phone and custom-written application (App, making this novel detection modality fully portable for point-of-care use.

  17. Pathogen detection, testing, and control in fresh broccoli sprouts

    Directory of Open Access Journals (Sweden)

    Fahey Jed W

    2006-04-01

    Full Text Available Abstract Background The recent increased interest in consuming green vegetable sprouts has been tempered by the fact that fresh sprouts can in some cases be vehicles for food-borne illnesses. They must be grown according to proper conditions of sanitation and handled as a food product rather than as an agricultural commodity. When sprouts are grown in accordance with the criteria proposed from within the sprout industry, developed by regulatory agencies, and adhered to by many sprouters, green sprouts can be produced with very low risk. Contamination may occur when these guidelines are not followed. Methods A one year program of microbial hold-and-release testing, conducted in concert with strict seed and facility cleaning procedures by 13 U.S. broccoli sprout growers was evaluated. Microbial contamination tests were performed on 6839 drums of sprouts, equivalent to about 5 million consumer packages of fresh green sprouts. Results Only 24 (0.75% of the 3191 sprout samples gave an initial positive test for Escherichia coli O157:H7 or Salmonella spp., and when re-tested, 3 drums again tested positive. Composite testing (e.g., pooling up to 7 drums for pathogen testing was equally sensitive to single drum testing. Conclusion By using a "test-and-re-test" protocol, growers were able to minimize crop destruction. By pooling drums for testing, they were also able to reduce testing costs which now represent a substantial portion of the costs associated with sprout growing. The test-and-hold scheme described herein allowed those few batches of contaminated sprouts to be found prior to packaging and shipping. These events were isolated, and only safe sprouts entered the food supply.

  18. Ingestion without inactivation of bacteriophages by Tetrahymena.

    Science.gov (United States)

    Akunyili, Agnes A; Alfatlawi, Miaad; Upadhyaya, Bandana; Rhoads, Laura S; Eichelberger, Henry; Van Bell, Craig T

    2008-01-01

    Tetrahymena has been shown to ingest and inactivate bacteriophages, such as T4, in co-incubation experiments. In this study, Tetrahymena thermophila failed to inactivate phages PhiX174 and MS2 in co-incubations, although PhiX174 were ingested by T. thermophila, as demonstrated by: (1) recovery at defecation in a pulse-chase experiment, (2) recovery from Tetrahymena by detergent lysis, and (3) transmission electron microscopy. We conclude, therefore, that the phages must be digestion-resistant. Internalized PhiX174 were further shown to be partially protected from lethal damage by ultraviolet (UV) C and UVB irradiation. Finally, ingested PhiX174 were shown to be rapidly transported through buffer in a horizontal swimming, race tube-like assay. The transport and protection of phages may confer evolutionary advantages that explain the acquisition of digestion-resistance by some phages.

  19. 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

  20. Selected food-borne parasites associated with cockroaches and ...

    African Journals Online (AJOL)

    Of these, 20 (62.5%) were protozoa and 12 (37.5%) were helminthes from the houseflies while 19 (54.3%) were protozoa and 16 (45.7%) were helminthes from the cockroaches. The protozoa that were identified include; cysts of Balantidium coli, cysts of Entamoeba coli, Entamoeba Histolytica and Endolimax nana. Also ...

  1. Molecular mechanisms of toxicity of important food-borne phytotoxins

    NARCIS (Netherlands)

    Rietjens, I.M.C.M.; Martena, M.J.; Boersma, M.G.; Spiegelenberg, W.; Alink, G.M.

    2005-01-01

    At present, there is an increasing interest for plant ingredients and their use in drugs, for teas, or in food supplements. The present review describes the nature and mechanism of action of the phytochemicals presently receiving increased attention in the field of food toxicology. This relates to

  2. 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.

  3. 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...

  4. Evaluation of Antibacterial Activities of Citrus limon, Citrus reticulata, and Citrus grandis Against Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Sholeh Saeb

    2016-11-01

    Full Text Available Background: Microorganisms resistant to most antibiotics are rapidly spreading, and there is an urgent and continuous need for novel antimicrobial compounds. The genus Citrus belongs to the family Rutaceae has many biologically active secondary metabolites. Objectives: The purpose of this study was to evaluate antimicrobial activity of essential oil and extract of Lemon (Citrus limon, Mandarin (Citrus reticulata and Pummelo (Citrus grandis against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Salmonella typhi. Materials and Methods: The fresh Citrus leaves were shade-dried and powdered. Antimicrobial metabolites were extracted from them by 80% methanol for extract and using a Clevenger-type apparatus for essential oil. Eight different concentrations of the each leaf extract and essential oil were prepared. The antimicrobial susceptibility assay of Citrus leaves metabolites were subjected against four bacterial strains by agar disc diffusion and E-test method. Results: In this study, minimum inhibitory concentrations (MIC of different Citrus leaf extracts were determined against all four food-borne pathogens. The C. grandis leaf essential oil had potent antimicrobial activity against all four pathogens, and the C. limon leaf essential oil was effective on Gram-positive bacteria. S. typhi was resistant against two leaves essential oils. Conclusions: The results showed that there was no antimicrobial activity effect in all extracts on tested bacteria. In this study, the antibacterial effect of essential oil of Citrus leaves on four strains of pathogenic microorganisms was confirmed. The C. grandis leaf essential oil had the most powerful antimicrobial properties, suggesting its potential application as natural preservative in foods or an effective medicine against different pathogenic microbes. Key words: Antibacterial activity, E-test, Citr

  5. 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

  6. 76 FR 71079 - Records Schedules; Availability and Request for Comments

    Science.gov (United States)

    2011-11-16

    ..., collects, and analyzes data about pesticide residues and food-borne pathogens in agricultural commodities... electronic information systems containing data on pesticide residues and food-borne pathogens on selected... relating to planning, funding, design, and construction. [[Page 71080

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Implicit dosimetry of microorganism photodynamic inactivation

    Science.gov (United States)

    Tamošiūnas, Mindaugas; Kuliešienė, Neringa; Daugelavičius, Rimantas

    2017-12-01

    Photosensitization based antibacterial treatment is efficient against a broad range of pathogens but it utilizes suboptimal dosimetry with an explicit (and very broad range) determination of sensitizer concentration, light dose and fluence rates. In this study we verified the implicit dosimetry approach for pathogen photodynamic treatment, employing protoporphyrin IX (ppIX) photobleaching to assess the killing efficacy against Staphylococcus aureus and Candida albicans cells. The results show that there was an increased kill of S. aureus and C. albicans at higher degree of ppIX fluorescence decay. Therefore ppIX photobleaching can be incorporated into the PDI dose metric offering to predict the pathogen killing efficacy during photodynamic treatment.

  12. Mechanisms of Inactivation of Dry Escherichia coli by High-Pressure Carbon Dioxide.

    Science.gov (United States)

    Chen, Yuan Yao; Temelli, Feral; Gänzle, Michael G

    2017-05-15

    High-pressure carbon dioxide processing is a promising technology for nonthermal food preservation. However, few studies have determined the lethality of high-pressure CO 2 on dry bacterial cells, and the mechanism of inactivation remains unknown. This study explored the mechanisms of inactivation by using Escherichia coli AW1.7 and mutant strains differing in heat and acid resistance, in membrane composition based on disruption of the locus of heat resistance, and in genes coding for glutamate decarboxylases and cyclopropane fatty acid synthase. The levels of lethality of treatments with liquid, gaseous, and supercritical CO 2 were compared. The cell counts of E. coli AW1.7 and mutants with a water activity (a W ) of 1.0 were reduced by more than 3 log 10 (CFU/ml) after supercritical CO 2 treatment at 35°C for 15 min; increasing the pressure generally enhanced inactivation, except for E. coli AW1.7 Δ gadAB E. coli AW1.7 Δ cfa was more susceptible than E. coli AW1.7 after treatment at 10 and 40 MPa; other mutations did not affect survival. Dry cells of E. coli were resistant to treatments with supercritical and liquid CO 2 at any temperature. Treatments with gaseous CO 2 at 65°C were more bactericidal than those with supercritical CO 2 or treatments at 65°C only. Remarkably, E. coli AW1.7 was more susceptible than E. coli AW1.7 Δ cfa when subjected to the gaseous CO 2 treatment. This study identified CO 2 -induced membrane fluidization and permeabilization as causes of supercritical mediated microbial inactivation, and diffusivity was a dominant factor for gaseous CO 2 IMPORTANCE The safety of dry foods is of increasing concern for public health. Desiccated microorganisms, including pathogens, remain viable over long periods of storage and generally tolerate environmental insults that are lethal to the same organisms at high water activity. This study explored the use of high-pressure carbon dioxide to determine its lethality for dried Escherichia coli and to

  13. 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.

  14. It is safe from O-157 and salmonellae. Food hygiene and food irradiation

    International Nuclear Information System (INIS)

    Ito, Hitoshi

    1998-01-01

    Despite the improvement of the systems of food hygiene and food distribution on the markets compared with old times, food-borne diseases are increasing and spreading in the world. Food-borne diseases by pathogenic Escherichia coli O-157:H7 are also increasing seriously. Japan has been importing the large amount of foodstuffs which sometimes contaminating with pathogens or parasites. Many types of food-borne diseases have been caused by non-spore forming bacteria such as salmonellae, V. parahaemolyticus, pathogenic E. coli, Campylobacter and Staphylococcus aureus, and these bacteria can inactivate at dose in the range of 1 - 3 kGy in chilled meat. These pathogenic bacteria can also inactivate in the range of 2 - 5 kGy in frozen condition of meat. For the inactivation of Bacillus cereus or Clostridium botulinum, necessary doses should be more than 10 kGy, however, a dose of 3 kGy is also effective to control the growth at storage below 10degC. Food-borne diseases have been caused also by mycotoxins of fungi in Japan. Aflatoxins and sterigmatocystin are carcinogens and are stable to radiation. However, many fungi for responsible to produce mycotoxins are radiation sensitive and should be easily inactivated in the range of 3 - 5 kGy. If moisture content is controlled below 15%, low dose irradiation is also effective in the range of 0.2 - 0.5 kGy to control the growth of fungi and pests in grain or other dried foods. (author)

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. Role of the sseK1 gene in the pathogenicity of Salmonella enterica serovar enteritidis in vitro and in vivo.

    Science.gov (United States)

    Yang, Yadong; Yu, Chuan; Ding, Ke; Zhang, Chunjie; Liao, Chengshui; Jia, Yanyan; Li, Jing; Cheng, Xiangchao

    2018-04-01

    Salmonella enteritidis is a common food-borne pathogen associated with consumption of contaminated poultry meat and eggs, which frequently causes gastroenteritis in humans. Salmonella secreted effector K1 (SseK1), as a translocated and secreted protein has been identified to be essential for the virulence of Salmonella typhimurium in host cells. However, the role of the sseK1 gene in the pathogenicity of S. enteritidis remain unclear. In this study, a sseK1 deletion mutant of S. enteritidis was constructed and its biological characteristics were examined. It was found that the sseK1 deletion mutant did not affect the growth, adherence and invasion of Salmonella enteritidis when compared to the wild-type S. enteritidis. However, the mutant showed decreased formation of biofilm and significantly reduced intracellular survival of bacteria in activated mouse peritoneal macrophages, as well as showed reduced pathogenicity to a murine model by increasing the lethal dose 50% (LD 50 ) value and decreasing the proliferation ratio of bacteria in vivo. Taken together, this study determined an important role for SseK1 in the pathogenicity of S. enteritidis in vitro and in vivo. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. An estimate of the cost of acute health effects from food- and water-borne marine pathogens and toxins in the USA.

    Science.gov (United States)

    Ralston, Erin P; Kite-Powell, Hauke; Beet, Andrew

    2011-12-01

    Large and growing segments of the United States population consume seafood or engage in marine recreation. These activities provide significant benefits but also bring risk of exposure to marine-borne illness. To manage these risks, it is important to understand the incidence and cost of marine-borne disease. We review the literature and surveillance/monitoring data to determine the annual incidence of disease and health consequences due to marine-borne pathogens from seafood consumption and beach recreation in the USA. Using this data, we employ a cost-of-illness model to estimate economic impacts. Our results suggest that health consequences due to marine-borne pathogens in the USA have annual costs on the order of US$900 million. This includes US$350 million due to pathogens and marine toxins specifically identified as causing food-borne disease, an estimated US$300 million due to seafood-borne disease with unknown etiology, US$30 million from direct exposure to the Vibrio species, and US$300 million due to gastrointestinal illness from beach recreation. Although there is considerable uncertainty about the degree of underreporting of certain pathogen-specific acute marine-related illnesses, the conservative assumptions we have used in constructing our estimate suggest that it should be considered a lower bound on true costs.

  1. 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.

  2. 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...... are pathogenic, precludes targeted healthcare for both carriers and their relatives. To facilitate the identification of pathogenic VUS, we have developed an in cellulo genetic screen-based procedure for the large-scale mutagenization, identification, and cataloging of residues of MMR genes critical for MMR gene...

  3. Modeling Radiation Effectiveness for Inactivation of Bacillus Spores

    Science.gov (United States)

    2015-09-17

    MODELING RADIATION EFFECTIVENESS FOR INACTIVATION OF BACILLUS SPORES DISSERTATION Emily A. Knight, Major, USAF AFIT-ENC-DS-15-S-001 DEPARTMENT OF THE...not subject to copyright protection in the United States. AFIT-ENC-DS-15-S-001 MODELING RADIATION EFFECTIVENESS FOR INACTIVATION OF BACILLUS SPORES...EFFECTIVENESS FOR INACTIVATION OF BACILLUS SPORES Emily A. Knight, B.A., M.S. Major, USAF Committee Membership: Dr. William P. Baker Chair Dr. Larry W

  4. Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in black pepper and red pepper by gamma irradiation.

    Science.gov (United States)

    Song, Won-Jae; Sung, Hye-Jung; Kim, Sung-Youn; Kim, Kwang-Pyo; Ryu, Sangryeol; Kang, Dong-Hyun

    2014-02-17

    This study evaluated the efficacy of gamma irradiation to inactivate foodborne pathogens in black pepper (Piper nigrum) and red pepper (dried Capsicum annuum). Black pepper and red pepper inoculated with Escherichia coli O157:H7 and Salmonella Typhimurium were subjected to gamma irradiation in the range of 0, 1, 2, 3 and 5 kGy, and color change was evaluated after treatment. Pathogen populations decreased with increasing treatment doses. A gamma irradiation dose of 5 kGy decreased E. coli O157:H7 and S. Typhimurium populations >4.4 to >5.2 log CFU/g in black pepper without causing color change. Similarly, 5 kGy of gamma irradiation yielded reduction of 3.8 to >5.2 log CFU/g for E. coli O157:H7 and S. Typhimurium in red pepper. During gamma irradiation treatment, L*, a* and b* values of red pepper were not significantly changed except for 297 μm to 420 μm size red pepper treated with 5 kGy of gamma irradiation. Based on the D-value of pathogens in black pepper and red pepper, S. Typhimurium showed more resistant to gamma irradiation than did E. coli O157:H7. These results show that gamma irradiation has potential as a non-thermal process for inactivating foodborne pathogens in spices with minimal color changes. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Radiation inactivation analysis of kidney microvillar peptidases

    International Nuclear Information System (INIS)

    Fulcher, I.S.; Ingram, J.; Kenny, A.J.

    1986-01-01

    Five membrane peptidases were studied by radiation inactivation analysis of pig kidney microvillar membranes. One heterodimeric enzyme, γ-glutamyl transferase, presented a target size corresponding to the dimeric M r . The other enzymes are known to be homodimers. Three of these, aminopeptidase A, aminopeptidase N and dipeptidyl peptidase 4, gave results clearly indicating the monomer to be the target and, hence, in this group the association of the subunits was not essential for activity. The target size for endopeptidase-24.11 was intermediate between those for monomer and dimer and its functional state was not resolved by the experiments. (Auth.)

  6. Gamma ray inactivation of some animal viruses.

    Science.gov (United States)

    Thomas, F C; Davies, A G; Dulac, G C; Willis, N G; Papp-Vid, G; Girard, A

    1981-10-01

    Twenty samples of animal viruses comprising 14 different viruses in 12 families were subjected to varying doses of gamma irradiation from a 60Co source in a Gamma Cell 220 (Atomic Energy of Canada Limited) to determine lethal dose levels. The dose responses appeared linear throughout inactivation. The D10 values, that is the dose necessary to reduce infectivity by one log10, ranged from less than 0.20 Megarads to approximately 0.55 Megarads. There was not a complete inverse correlation between the target size (virion core) and the D10 value.

  7. Gamma ray inactivation of some animal viruses.

    OpenAIRE

    Thomas, F C; Davies, A G; Dulac, G C; Willis, N G; Papp-Vid, G; Girard, A

    1981-01-01

    Twenty samples of animal viruses comprising 14 different viruses in 12 families were subjected to varying doses of gamma irradiation from a 60Co source in a Gamma Cell 220 (Atomic Energy of Canada Limited) to determine lethal dose levels. The dose responses appeared linear throughout inactivation. The D10 values, that is the dose necessary to reduce infectivity by one log10, ranged from less than 0.20 Megarads to approximately 0.55 Megarads. There was not a complete inverse correlation betwee...

  8. 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.

  9. Plant pathogen resistance

    Science.gov (United States)

    Greenberg, Jean T; Jung, Ho Won; Tschaplinski, Timothy

    2012-11-27

    Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

  10. 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

  11. Structurally Distinct Bacterial TBC-like GAPs Link Arf GTPase to Rab1 Inactivation to Counteract Host Defenses

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Na; Zhu, Yongqun; Lu, Qiuhe; Hu, Liyan; Zheng, Yuqing; Shao, Feng (NIBS-China); (Zhejiang)

    2012-10-10

    Rab GTPases are frequent targets of vacuole-living bacterial pathogens for appropriate trafficking of the vacuole. Here we discover that bacterial effectors including VirA from nonvacuole Shigella flexneri and EspG from extracellular Enteropathogenic Escherichia coli (EPEC) harbor TBC-like dual-finger motifs and exhibits potent RabGAP activities. Specific inactivation of Rab1 by VirA/EspG disrupts ER-to-Golgi trafficking. S. flexneri intracellular persistence requires VirA TBC-like GAP activity that mediates bacterial escape from autophagy-mediated host defense. Rab1 inactivation by EspG severely blocks host secretory pathway, resulting in inhibited interleukin-8 secretion from infected cells. Crystal structures of VirA/EspG-Rab1-GDP-aluminum fluoride complexes highlight TBC-like catalytic role for the arginine and glutamine finger residues and reveal a 3D architecture distinct from that of the TBC domain. Structure of Arf6-EspG-Rab1 ternary complex illustrates a pathogenic signaling complex that rewires host Arf signaling to Rab1 inactivation. Structural distinctions of VirA/EspG further predict a possible extensive presence of TBC-like RabGAP effectors in counteracting various host defenses.

  12. Egg white versus Salmonella Enteritidis! A harsh medium meets a resilient pathogen.

    Science.gov (United States)

    Baron, Florence; Nau, Françoise; Guérin-Dubiard, Catherine; Bonnassie, Sylvie; Gautier, Michel; Andrews, Simon C; Jan, Sophie

    2016-02-01

    Salmonella enterica serovar Enteritidis is the prevalent egg-product-related food-borne pathogen. The egg-contamination capacity of S. Enteritidis includes its exceptional survival capability within the harsh conditions provided by egg white. Egg white proteins, such as lysozyme and ovotransferrin, are well known to play important roles in defence against bacterial invaders. Indeed, several additional minor proteins and peptides have recently been found to play known or potential roles in protection against bacterial contamination. However, although such antibacterial proteins are well studied, little is known about their efficacy under the environmental conditions prevalent in egg white. Thus, the influence of factors such as temperature, alkalinity, nutrient restriction, viscosity and cooperative interactions on the activities of antibacterial proteins in egg white remains unclear. This review critically assesses the available evidence on the antimicrobial components of egg white. In addition, mechanisms employed by S. Enteritidis to resist egg white exposure are also considered along with various genetic studies that have shed light upon egg white resistance systems. We also consider how multiple, antibacterial proteins operate in association with specific environmental factors within egg white to generate a lethal protective cocktail that preserves sterility. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Antimicrobial Activity of Kefir against Various Food Pathogens and Spoilage Bacteria.

    Science.gov (United States)

    Kim, Dong-Hyeon; Jeong, Dana; Kim, Hyunsook; Kang, Il-Byeong; Chon, Jung-Whan; Song, Kwang-Young; Seo, Kun-Ho

    2016-01-01

    Kefir is a unique fermented dairy product produced by a mixture of lactic acid bacteria, acetic acid bacteria, and yeast. Here, we compared the antimicrobial spectra of four types of kefirs (A, L, M, and S) fermented for 24, 36, 48, or 72 h against eight food-borne pathogens. Bacillus cereus , Staphylococcus aureus , Listeria monocytogenes , Enterococcus faecalis , Escherichia coli , Salmonella Enteritidis , Pseudomonas aeruginosa , and Cronobacter sakazakii were used as test strains, and antibacterial activity was investigated by the spot on lawn method. The spectra, potencies, and onsets of activity varied according to the type of kefir and the fermentation time. The broadest and strongest antimicrobial spectrum was obtained after at least 36-48 h of fermentation for all kefirs, although the traditional fermentation method of kefir is for 18-24 h at 25℃. For kefir A, B. cereus , E. coli , S . Enteritidis, P. aeruginosa , and C. sakazakii were inhibited, while B. cereus , S. aureus , E. coli , S . Enteritidis, P. aeruginosa , and C. sakazakii were inhibited to different extents by kefirs L, M, and S. Remarkably, S. aureus , S . Enteritidis, and C. sakazakii were only inhibited by kefirs L, M, and S, and L. monocytogenes by kefir M after fermentation for specific times, suggesting that the antimicrobial activity is attributable not only to a low pH but also to antimicrobial substances secreted during the fermentation.

  14. Monitoring chicken flock behaviour provides early warning of infection by human pathogen Campylobacter.

    Science.gov (United States)

    Colles, Frances M; Cain, Russell J; Nickson, Thomas; Smith, Adrian L; Roberts, Stephen J; Maiden, Martin C J; Lunn, Daniel; Dawkins, Marian Stamp

    2016-01-13

    Campylobacter is the commonest bacterial cause of gastrointestinal infection in humans, and chicken meat is the major source of infection throughout the world. Strict and expensive on-farm biosecurity measures have been largely unsuccessful in controlling infection and are hampered by the time needed to analyse faecal samples, with the result that Campylobacter status is often known only after a flock has been processed. Our data demonstrate an alternative approach that monitors the behaviour of live chickens with cameras and analyses the 'optical flow' patterns made by flock movements. Campylobacter-free chicken flocks have higher mean and lower kurtosis of optical flow than those testing positive for Campylobacter by microbiological methods. We show that by monitoring behaviour in this way, flocks likely to become positive can be identified within the first 7-10 days of life, much earlier than conventional on-farm microbiological methods. This early warning has the potential to lead to a more targeted approach to Campylobacter control and also provides new insights into possible sources of infection that could transform the control of this globally important food-borne pathogen. © 2016 The Authors.

  15. Stress response and pathogenic potential of Campylobacter jejuni cells exposed to starvation.

    Science.gov (United States)

    Klancnik, Anja; Guzej, Bernarda; Jamnik, Polona; Vucković, Darinka; Abram, Maja; Mozina, Sonja Smole

    2009-06-01

    Campylobacter jejuni is a Gram-negative, fragile, spiral bacterium, known worldwide to be a major cause of acute human enteritis. Like many other food-borne bacteria, campylobacters must be able to survive under diverse conditions both inside the host and in the environment. Understanding stress response mechanisms provides information necessary for improving food processing and strategies that enhance food safety as well as clarifying the p