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Sample records for rank enteric pathogens

  1. Enteric pathogens through life stages

    PubMed Central

    Kolling, Glynis; Wu, Martin; Guerrant, Richard L.

    2012-01-01

    Enteric infections and diarrheal diseases constitute pervasive health burdens throughout the world, with rates being highest at the two ends of life. During the first 2–3 years of life, much of the disease burden may be attributed to infection with enteric pathogens including Salmonella, rotavirus, and many other bacterial, viral, and protozoan organisms; however, infections due to Clostridium difficile exhibit steady increases with age. Still others, like Campylobacter infections in industrialized settings are high in early life (<2 years old) and increase again in early adulthood (called the “second weaning” by some). The reasons for these differences undoubtedly reside in part in pathogen differences; however, host factors including the commensal intestinal microbial communities, immune responses (innate and acquired), and age-dependant shifts likely play important roles. Interplay of these factors is illustrated by studies examining changes in human gut microbiota with inflammatory bowel disease and irritable bowel syndrome. Recent gut microbial surveys have indicated dramatic shifts in gut microbial population structure from infants to young adults to the elders. An understanding of the evolution of these factors and their interactions (e.g., how does gut microbiota modulate the “inflamm-aging” process or vice versa) through the human life “cycle” will be important in better addressing and controlling these enteric infections and their consequences for both quality and quantity of life (often assessed as disability adjusted life-years or “DALYs”). PMID:22937528

  2. Detection of enteric pathogens by the nodosome.

    PubMed

    Keestra, A Marijke; Bäumler, Andreas J

    2014-03-01

    Nucleotide-binding oligomerization domain protein (NOD)1 and NOD2 participate in signaling pathways that detect pathogen-induced processes, such as the presence of peptidoglycan fragments in the host cell cytosol, as danger signals. Recent work suggests that peptidoglycan fragments activate NOD1 indirectly, through activation of the small Rho GTPase Ras-related C3 botulinum toxin substrate 1 (RAC1). Excessive activation of small Rho GTPases by virulence factors of enteric pathogens also triggers the NOD1 signaling pathway. Many enteric pathogens use virulence factors that alter the activation state of small Rho GTPases, thereby manipulating the host cell cytoskeleton of intestinal epithelial cells to promote bacterial attachment or entry. These data suggest that the NOD1 signaling pathway in intestinal epithelial cells provides an important sentinel function for detecting 'breaking and entering' by enteric pathogens. PMID:24268520

  3. Detection of enteric pathogens by the nodosome

    PubMed Central

    Keestra, A. Marijke; Bäumler, Andreas J.

    2014-01-01

    Nucleotide-binding oligomerization domain protein (NOD)1 and NOD2 participate in signaling pathways that detect pathogen-induced processes, such as the presence of peptidoglycan fragments in the host cell cytosol, as danger signals. Recent work suggests that peptidoglycan fragments activate NOD1 indirectly, through activation of the small Rho GTPase Ras-related C3 botulinum toxin substrate 1 (RAC1). Excessive activation of small Rho GTPases by virulence factors of enteric pathogens also triggers the NOD1 signaling pathway. Many enteric pathogens use virulence factors that alter the activation state of small Rho GTPases, thereby manipulating the host cell cytoskeleton of intestinal epithelial cells to promote bacterial attachment or entry. These data suggest that the NOD1 signaling pathway in intestinal epithelial cells provides an important sentinel function for detecting ‘breaking and entering’ by enteric pathogens. PMID:24268520

  4. Infection strategies of enteric pathogenic Escherichia coli

    PubMed Central

    Clements, Abigail; Young, Joanna C.; Constantinou, Nicholas; Frankel, Gad

    2012-01-01

    Enteric Escherichia coli (E. coli) are both natural flora of humans and important pathogens causing significant morbidity and mortality worldwide. Traditionally enteric E. coli have been divided into 6 pathotypes, with further pathotypes often proposed. In this review we suggest expansion of the enteric E. coli into 8 pathotypes to include the emerging pathotypes of adherent invasive E. coli (AIEC) and Shiga-toxin producing enteroaggregative E. coli (STEAEC). The molecular mechanisms that allow enteric E. coli to colonize and cause disease in the human host are examined and for two of the pathotypes that express a type 3 secretion system (T3SS) we discuss the complex interplay between translocated effectors and manipulation of host cell signaling pathways that occurs during infection. PMID:22555463

  5. The Interaction of Human Enteric Pathogens with Plants

    PubMed Central

    Lim, Jeong-A; Lee, Dong Hwan; Heu, Sunggi

    2014-01-01

    There are an increasing number of outbreaks of human pathogens related to fresh produce. Thus, the growth of human pathogens on plants should be explored. Human pathogens can survive under the harsh environments in plants, and can adhere and actively invade plants. Plant-associated microbiota or insects contribute to the survival and transmission of enteric pathogens in plants. Human enteric pathogens also trigger plant innate immunity, but some pathogens–such as Salmonella–can overcome this defense mechanism. PMID:25288993

  6. IMMUNOGENOMIC APPROACHES TO STUDY HOST IMMUNITY TO ENTERIC PATHOGENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With increasing consumer’s demands for safe poultry products, effective control of disease-causing pathogens is becoming a major challenge to the poultry industry. Many chicken pathogens enter the host through the gastrointestinal tract, and over the past few decades in-feed antibiotics and active ...

  7. Structure of an Enteric Pathogen, Bovine Parvovirus

    PubMed Central

    Kailasan, Shweta; Halder, Sujata; Gurda, Brittney; Bladek, Heather; Chipman, Paul R.; McKenna, Robert; Brown, Kevin

    2014-01-01

    ABSTRACT Bovine parvovirus (BPV), the causative agent of respiratory and gastrointestinal disease in cows, is the type member of the Bocaparvovirus genus of the Parvoviridae family. Toward efforts to obtain a template for the development of vaccines and small-molecule inhibitors for this pathogen, the structure of the BPV capsid, assembled from the major capsid viral protein 2 (VP2), was determined using X-ray crystallography as well as cryo-electron microscopy and three-dimensional image reconstruction (cryo-reconstruction) to 3.2- and 8.8-Å resolutions, respectively. The VP2 region ordered in the crystal structure, from residues 39 to 536, conserves the parvoviral eight-stranded jellyroll motif and an αA helix. The BPV capsid displays common parvovirus features: a channel at and depressions surrounding the 5-fold axes and protrusions surrounding the 3-fold axes. However, rather than a depression centered at the 2-fold axes, a raised surface loop divides this feature in BPV. Additional observed density in the capsid interior in the cryo-reconstructed map, compared to the crystal structure, is interpreted as 10 additional N-terminal residues, residues 29 to 38, that radially extend the channel under the 5-fold axis, as observed for human bocavirus 1 (HBoV1). Surface loops of various lengths and conformations extend from the core jellyroll motif of VP2. These loops confer the unique surface topology of the BPV capsid, making it strikingly different from HBoV1 as well as the type members of other Parvovirinae genera for which structures have been determined. For the type members, regions structurally analogous to those decorating the BPV capsid surface serve as determinants of receptor recognition, tissue and host tropism, pathogenicity, and antigenicity. IMPORTANCE Bovine parvovirus (BPV), identified in the 1960s in diarrheic calves, is the type member of the Bocaparvovirus genus of the nonenveloped, single-stranded DNA (ssDNA) Parvoviridae family. The recent

  8. The Impact of Oxygen on Bacterial Enteric Pathogens.

    PubMed

    Wallace, N; Zani, A; Abrams, E; Sun, Y

    2016-01-01

    Bacterial enteric pathogens are responsible for a tremendous amount of foodborne illnesses every year through the consumption of contaminated food products. During their transit from contaminated food sources to the host gastrointestinal tract, these pathogens are exposed and must adapt to fluctuating oxygen levels to successfully colonize the host and cause diseases. However, the majority of enteric infection research has been conducted under aerobic conditions. To raise awareness of the importance in understanding the impact of oxygen, or lack of oxygen, on enteric pathogenesis, we describe in this review the metabolic and physiological responses of nine bacterial enteric pathogens exposed to environments with different oxygen levels. We further discuss the effects of oxygen levels on virulence regulation to establish potential connections between metabolic adaptations and bacterial pathogenesis. While not providing an exhaustive list of all bacterial pathogens, we highlight key differences and similarities among nine facultative anaerobic and microaerobic pathogens in this review to argue for a more in-depth understanding of the diverse impact oxygen levels have on enteric pathogenesis. PMID:27261784

  9. Enteric Pathogens Associated with Childhood Diarrhea in Tripoli-Libya

    PubMed Central

    Rahouma, Amal; Klena, John D.; Krema, Zaineb; Abobker, Abdalwahed A.; Treesh, Khalid; Franka, Ezzedin; Abusnena, Omar; Shaheen, Hind I.; El Mohammady, Hanan; Abudher, Abdulhafid; Ghenghesh, Khalifa Sifaw

    2011-01-01

    Stool samples from children < 5 years of age with diarrhea (N = 239) were examined for enteric pathogens using a combination of culture, enzyme-immunoassay, and polymerase chain reaction methods. Pathogens were detected in 122 (51%) stool samples; single pathogens were detected in 37.2% and co-pathogens in 13.8% of samples. Norovirus, rotavirus, and diarrheagenic Escherichia coli (DEC) were the most frequently detected pathogens (15.5%, 13.4%, and 11.2%, respectively); Salmonella, adenovirus, and Aeromonas were detected less frequently (7.9%, 7.1%, and 4.2%). The most commonly detected DEC was enteroaggregative E. coli (5.4%). Resistance to ≥ 3 antimicrobials was observed in 60% (18/30) of the bacterial pathogens. Salmonella resistance to ciprofloxacin (63.1%) has become a concern. Enteric viral pathogens were the most significant causative agents of childhood diarrhea in Tripoli. Bacterial pathogens were also important contributors to pediatric diarrhea. The emergence of ciprofloxacin-resistant Salmonella represents a serious health problem that must be addressed by Libyan health authorities PMID:21633024

  10. Detection of enteric pathogens in Turkey flocks affected with severe enteritis, in Brazil.

    PubMed

    Moura-Alvarez, Joelma; Nuñez, Luis F N; Astolfi-Ferreira, Claudete S; Knöbl, Terezinha; Chacón, Jorge L; Moreno, Andrea M; Jones, Richard C; Ferreira, Antonio J Piantino

    2014-08-01

    Twenty-two flocks of turkeys affected by enteric problems, with ages between 10 and 104 days and located in the Southern region of Brazil, were surveyed for turkey by PCR for turkey astrovirus type 2 (TAstV-2), turkey coronavirus (TCoV), hemorrhagic enteritis virus (HEV), rotavirus, reovirus, Salmonella spp., and Lawsonia intracellularis (Li) infections. Eleven profiles of pathogen combination were observed. The most frequently encountered pathogen combinations were TCoV-Li, followed by TCoV-TAstV-2-Li, TCoV-TastV-2. Only TCoV was detected as the sole pathogen in three flocks. Eight and 19 flocks of the 22 were positive for TAstV-2 and TCoV, respectively. Six were positive for Salmonella spp. and L. intracellularis was detected in 12 turkey flocks. Reovirus and HEV were not detected in this survey. These results throw new light on the multiple etiology of enteritis in turkeys. The implications of these findings and their correlation with the clinical signs are comprehensively discussed, illustrating the complexity of the enteric diseases. PMID:24817479

  11. Enteric pathogenic protozoa in homosexual men from San Francisco.

    PubMed

    Ortega, H B; Borchardt, K A; Hamilton, R; Ortega, P; Mahood, J

    1984-01-01

    The prevalence of enteric protozoa was studied in a survey conducted among 150 male homosexual patients in San Francisco. All patients were from a private practice in internal medicine. Each was asked to complete a questionnaire and to submit multiple stool specimens for examination. Of this group, 47% were positive for one or more potentially pathogenic intestinal protozoa; Entamoeba histolytica was found in 36%, Entamoeba hartmanni in 35%, Giardia lamblia in 5%, and Dientamoeba fragilis in 1.3%. Symptoms were unreliable as a diagnostic index of intestinal protozoan infection. Colonization rates could not be correlated with any specific sexual technique. The large number of homosexuals at risk, combined with the potential for difficulties in diagnosis and contact-tracing, indicate the possibility that enteric pathogenic protozoa will cause future health problems in this population. PMID:6087479

  12. The Role of Carbohydrates in Infection Strategies of Enteric Pathogens

    PubMed Central

    Kato, Kentaro; Ishiwa, Akiko

    2015-01-01

    Enteric pathogens cause considerable public health concerns worldwide including tropical regions. Here, we review the roles of carbohydrates in the infection strategies of various enteric pathogens including viruses, bacteria and protozoa, which infect the epithelial lining of the human and animal intestine. At host cell entry, enteric viruses, including norovirus, recognize mainly histo-blood group antigens. At the initial step of bacterial infections, carbohydrates also function as receptors for attachment. Here, we describe the function of carbohydrates in infection by Salmonella enterica and several bacterial species that produce a variety of fimbrial adhesions. During invasion by enteropathogenic protozoa, apicomplexan parasites utilize sialic acids or sulfated glycans. Carbohydrates serve as receptors for infection by these microbes; however, their usage of carbohydrates varies depending on the microbe. On the surface of the mucosal tissues of the gastrointestinal tract, various carbohydrate moieties are present and play a crucial role in infection, representing the site of infection or route of access for most microbes. During the infection and/or invasion process of the microbes, carbohydrates function as receptors for various microbes, but they can also function as a barrier to infection. One approach to develop effective prophylactic and therapeutic antimicrobial agents is to modify the drug structure. Another approach is to modify the mode of inhibition of infection depending on the individual pathogen by using and mimicking the interactions with carbohydrates. In addition, similarities in mode of infection may also be utilized. Our findings will be useful in the development of new drugs for the treatment of enteric pathogens. PMID:25859152

  13. Tracing enteric pathogen contamination in sub-Saharan African groundwater.

    PubMed

    Sorensen, J P R; Lapworth, D J; Read, D S; Nkhuwa, D C W; Bell, R A; Chibesa, M; Chirwa, M; Kabika, J; Liemisa, M; Pedley, S

    2015-12-15

    Quantitative PCR (qPCR) can rapidly screen for an array of faecally-derived bacteria, which can be employed as tracers to understand groundwater vulnerability to faecal contamination. A microbial DNA qPCR array was used to examine 45 bacterial targets, potentially relating to enteric pathogens, in 22 groundwater supplies beneath the city of Kabwe, Zambia in both the dry and subsequent wet season. Thermotolerant (faecal) coliforms, sanitary risks, and tryptophan-like fluorescence, an emerging real-time reagentless faecal indicator, were also concurrently investigated. There was evidence for the presence of enteric bacterial contamination, through the detection of species and group specific 16S rRNA gene fragments, in 72% of supplies where sufficient DNA was available for qPCR analysis. DNA from the opportunistic pathogen Citrobacter freundii was most prevalent (69% analysed samples), with Vibrio cholerae also perennially persistent in groundwater (41% analysed samples). DNA from other species such as Bifidobacterium longum and Arcobacter butzleri was more seasonally transient. Bacterial DNA markers were most common in shallow hand-dug wells in laterite/saprolite implicating rapid subsurface pathways and vulnerability to pollution at the surface. Boreholes into the underlying dolomites were also contaminated beneath the city highlighting that a laterite/saprolite overburden, as occurs across much of sub-Saharan aquifer, does not adequately protect underlying bedrock groundwater resources. Nevertheless, peri-urban boreholes all tested negative establishing there is limited subsurface lateral transport of enteric bacteria outside the city limits. Thermotolerant coliforms were present in 97% of sites contaminated with enteric bacterial DNA markers. Furthermore, tryptophan-like fluorescence was also demonstrated as an effective indicator and was in excess of 1.4μg/L in all contaminated sites. PMID:26363144

  14. A Review Approaches to Identify Enteric Bacterial Pathogens

    PubMed Central

    Amani, Jafar; Mirhosseini, Seyed Ali; Imani Fooladi, Abbas Ali

    2014-01-01

    Context: Diarrhea is a common disease across the world. According to WHO, every year about two billion cases of diarrhea are reported in the world. It occurs mainly in the tropical regions and is a main cause of morbidity and mortality, particularly in young children and adults. Evidence Acquisition: One of the major causes of diarrheal diseases is bacteria; detection of pathogenic bacteria is a global key to the prevention and identification of food-borne diseases and enteric infections (like diarrhea). Conclusions: Therefore, development of rapid diagnostic methods with suitable sensitivity and specificity is very important about this infectious disease. In this review, we will discuss some of the important diagnostic methods. PMID:25793091

  15. Pathogenic simian immunodeficiency virus infection is associated with expansion of the enteric virome

    PubMed Central

    Handley, Scott; Thackray, Larissa B.; Zhao, Guoyan; Presti, Rachel; Miller, Andrew; Droit, Lindsay; Abbink, Peter; Maxfield, Lori F.; Kambal, Amal; Duan, Erning; Stanley, Kelly; Kramer, Joshua; Macri, Sheila C.; Permar, Sallie R.; Schmitz, Joern E.; Mansfield, Keith; Brenchley, Jason M.; Veazey, Ronald S.; Stappenbeck, Thaddeus S.; Wang, David; Barouch, Dan H.; Virgin, Herbert W.

    2012-01-01

    SUMMARY Pathogenic simian immunodeficiency virus (SIV) infection is associated with enteropathy which likely contributes to AIDS progression. To identify candidate etiologies for AIDS enteropathy, we used next generation sequencing to define the enteric virome during SIV infection in nonhuman primates. Pathogenic, but not non-pathogenic, SIV infection was associated with significant expansion of the enteric virome. We identified at least 32 previously undescribed enteric viruses during pathogenic SIV infection and confirmed their presence using viral culture and PCR testing. We detected unsuspected mucosal adenovirus infection associated with enteritis as well as parvovirus viremia in animals with advanced AIDS, indicating the pathogenic potential of SIV-associated expansion of the enteric virome. No association between pathogenic SIV infection and the family-level taxonomy of enteric bacteria was detected. Thus, enteric viral infections may contribute to AIDS enteropathy and disease progression. These findings underline the importance of metagenomic analysis of the virome for understanding AIDS pathogenesis. PMID:23063120

  16. INACTIVATION OF ENTERIC PATHOGENS DURING AEROBIC DIGESTION OF WASTEWATER SLUDGE

    EPA Science Inventory

    The effects of aerobic and anaerobic digestion on enteric viruses, enteric bacteria, total aerobic bacteria, and intestinal parasites were studied under laboratory and field conditions. Under laboratory conditions, the temperature of the sludge digestion was the major factor infl...

  17. Enteric pathogens and gut function: role of cytokines and STATs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The gut harbors the largest immune system in the body. The mucosa is considered to be the initial site of interaction with commensal and pathogenic organisms; therefore, it is the first line of defense against pathogens. In response to the invasion of various pathogens, naïve CD4+ cells differenti...

  18. Recent Advances in Understanding Enteric Pathogenic Escherichia coli

    PubMed Central

    Croxen, Matthew A.; Law, Robyn J.; Scholz, Roland; Keeney, Kristie M.; Wlodarska, Marta

    2013-01-01

    SUMMARY Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli. PMID:24092857

  19. Enteric infection meets intestinal function: how bacterial pathogens cause diarrhoea

    PubMed Central

    Viswanathan, V. K.; Hodges, Kim; Hecht, Gail

    2012-01-01

    Infectious diarrhoea is a significant contributor to morbidity and mortality worldwide. In bacterium-induced diarrhoea, rapid loss of fluids and electrolytes results from inhibition of the normal absorptive function of the intestine as well as the activation of secretory processes. Advances in the past 10 years in the fields of gastrointestinal physiology, innate immunity and enteric bacterial virulence mechanisms highlight the multifactorial nature of infectious diarrhoea. This Review explores the various mechanisms that contribute to loss of fluids and electrolytes following bacterial infections, and attempts to link these events to specific virulence factors and toxins. PMID:19116615

  20. Human-derived probiotic Lactobacillus reuteri demonstrate antimicrobial activities targeting diverse enteric bacterial pathogens.

    PubMed

    Spinler, Jennifer K; Taweechotipatr, Malai; Rognerud, Cheryl L; Ou, Ching N; Tumwasorn, Somying; Versalovic, James

    2008-06-01

    Lactobacillus reuteri is a commensal-derived anaerobic probiotic that resides in the human gastrointestinal tract. L. reuteri converts glycerol into a potent broad-spectrum antimicrobial compound, reuterin, which inhibits the growth of gram-positive and gram-negative bacteria. In this study, we compared four human-derived L. reuteri isolates (ATCC 55730, ATCC PTA 6475, ATCC PTA 4659 and ATCC PTA 5289) in their ability to produce reuterin and to inhibit the growth of different enteric pathogens in vitro. Reuterin was produced by each of the four L. reuteri strains and assessed for biological activity. The minimum inhibitory concentration (MIC) of reuterin derived from each strain was determined for the following enteric pathogens: enterohemorrhagic Escherichia coli, enterotoxigenic E. coli, Salmonella enterica, Shigella sonnei and Vibrio cholerae. We also analyzed the relative abilities of L. reuteri to inhibit enteric pathogens in a pathogen overlay assay. The magnitude of reuterin production did not directly correlate with the relative ability of L. reuteri to suppress the proliferation of enteric pathogens. Additional antimicrobial factors may be produced by L. reuteri, and multiple factors may act synergistically with reuterin to inhibit enteric pathogens. PMID:18396068

  1. The Enteric Two-Step: nutritional strategies of bacterial pathogens within the gut

    PubMed Central

    Ferreyra, Jessica A.; Ng, Katharine M.; Sonnenburg, Justin L.

    2016-01-01

    Summary The gut microbiota is a dense and diverse microbial community governed by dynamic microbe–microbe and microbe–host interactions, the status of which influences whether enteric pathogens can cause disease. Here we review recent insights into the key roles that nutrients play in bacterial pathogen exploitation of the gut microbial ecosystem. We synthesize recent findings to support a five-stage model describing the transition between a healthy microbiota and one dominated by a pathogen and disease. Within this five-stage model, two stages are critical to the pathogen: (i) an initial expansion phase that must occur in the absence of pathogen-induced inflammation, followed by (ii) pathogen-promoting physiological changes such as inflammation and diarrhoea. We discuss how this emerging paradigm of pathogen life within the lumen of the gut is giving rise to novel therapeutic strategies. PMID:24720567

  2. Human enteric pathogens in produce: un-answered ecological questions with direct implications for food safety.

    PubMed

    Teplitski, Max; Barak, Jeri D; Schneider, Keith R

    2009-04-01

    Recent outbreaks of gastroenteritis linked to the consumption of fresh produce raise questions about the mechanisms by which human pathogens colonize plants and persist within marketable produce. Neither Salmonella nor Escherichia coli appear to produce enzymes that degrade plant cell walls, therefore it is not yet certain how these bacteria enter plant tissues and spread within them. Similar to plant-associated bacteria, enterics use cellulose and aggregative fimbriae for their attachment to plant surfaces. Salmonella can be an effective plant endophyte, even though it is capable of triggering plant defenses. Plant-associated microbiota contributes to the fitness and translocation of these human pathogens within plant hosts, although interactions and mechanisms of communication between plant-associated microbiota and enteric pathogens are not yet characterized. PMID:19349159

  3. The spore differentiation pathway in the enteric pathogen Clostridium difficile.

    PubMed

    Pereira, Fátima C; Saujet, Laure; Tomé, Ana R; Serrano, Mónica; Monot, Marc; Couture-Tosi, Evelyne; Martin-Verstraete, Isabelle; Dupuy, Bruno; Henriques, Adriano O

    2013-01-01

    Endosporulation is an ancient bacterial developmental program that culminates with the differentiation of a highly resistant endospore. In the model organism Bacillus subtilis, gene expression in the forespore and in the mother cell, the two cells that participate in endospore development, is governed by cell type-specific RNA polymerase sigma subunits. σ(F) in the forespore, and σ(E) in the mother cell control early stages of development and are replaced, at later stages, by σ(G) and σ(K), respectively. Starting with σ(F), the activation of the sigma factors is sequential, requires the preceding factor, and involves cell-cell signaling pathways that operate at key morphological stages. Here, we have studied the function and regulation of the sporulation sigma factors in the intestinal pathogen Clostridium difficile, an obligate anaerobe in which the endospores are central to the infectious cycle. The morphological characterization of mutants for the sporulation sigma factors, in parallel with use of a fluorescence reporter for single cell analysis of gene expression, unraveled important deviations from the B. subtilis paradigm. While the main periods of activity of the sigma factors are conserved, we show that the activity of σ(E) is partially independent of σ(F), that σ(G) activity is not dependent on σ(E), and that the activity of σ(K) does not require σ(G). We also show that σ(K) is not strictly required for heat resistant spore formation. In all, our results indicate reduced temporal segregation between the activities of the early and late sigma factors, and reduced requirement for the σ(F)-to-σ(E), σ(E)-to-σ(G), and σ(G)-to-σ(K) cell-cell signaling pathways. Nevertheless, our results support the view that the top level of the endosporulation network is conserved in evolution, with the sigma factors acting as the key regulators of the pathway, established some 2.5 billion years ago upon its emergence at the base of the Firmicutes Phylum. PMID

  4. The Spore Differentiation Pathway in the Enteric Pathogen Clostridium difficile

    PubMed Central

    Pereira, Fátima C.; Saujet, Laure; Tomé, Ana R.; Serrano, Mónica; Monot, Marc; Couture-Tosi, Evelyne; Martin-Verstraete, Isabelle; Dupuy, Bruno; Henriques, Adriano O.

    2013-01-01

    Endosporulation is an ancient bacterial developmental program that culminates with the differentiation of a highly resistant endospore. In the model organism Bacillus subtilis, gene expression in the forespore and in the mother cell, the two cells that participate in endospore development, is governed by cell type-specific RNA polymerase sigma subunits. σF in the forespore, and σE in the mother cell control early stages of development and are replaced, at later stages, by σG and σK, respectively. Starting with σF, the activation of the sigma factors is sequential, requires the preceding factor, and involves cell-cell signaling pathways that operate at key morphological stages. Here, we have studied the function and regulation of the sporulation sigma factors in the intestinal pathogen Clostridium difficile, an obligate anaerobe in which the endospores are central to the infectious cycle. The morphological characterization of mutants for the sporulation sigma factors, in parallel with use of a fluorescence reporter for single cell analysis of gene expression, unraveled important deviations from the B. subtilis paradigm. While the main periods of activity of the sigma factors are conserved, we show that the activity of σE is partially independent of σF, that σG activity is not dependent on σE, and that the activity of σK does not require σG. We also show that σK is not strictly required for heat resistant spore formation. In all, our results indicate reduced temporal segregation between the activities of the early and late sigma factors, and reduced requirement for the σF-to-σE, σE-to-σG, and σG-to-σK cell-cell signaling pathways. Nevertheless, our results support the view that the top level of the endosporulation network is conserved in evolution, with the sigma factors acting as the key regulators of the pathway, established some 2.5 billion years ago upon its emergence at the base of the Firmicutes Phylum. PMID:24098139

  5. Effect of citrus pulp on the viability of Saccharomyces boulardii in the presence of enteric pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Saccharomyces cerevisiae subtype boulardii is frequently used as a dietary supplement to promote intestinal health and reduce the impact of growth of enteric pathogens in livestock, including cattle and swine. Citrus by-products are also fed as dietary supplements that have the additional benefit o...

  6. Pilot study using wheat bran to mitigate malnutrition and enteric pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2015, 4.9 million children under the age of five died from infectious, neonatal, or nutritional conditions. Malnourished children have an increased susceptibility to enteric pathogens and diarrhea, which flush commensal bacteria from the intestines. Commensal bacteria in the intestines regulate n...

  7. Enteritis

    MedlinePlus

    ... with suspected enteric infection. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 24th ed. Philadelphia, PA: ... with diarrhea and malabsorption. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 24th ed. Philadelphia, PA: ...

  8. The production and detoxification of a potent cytotoxin, nitric oxide, by pathogenic enteric bacteria.

    PubMed

    Arkenberg, Anke; Runkel, Sebastian; Richardson, David J; Rowley, Gary

    2011-12-01

    The nitrogen cycle is based on several redox reactions that are mainly accomplished by prokaryotic organisms, some archaea and a few eukaryotes, which use these reactions for assimilatory, dissimilatory or respiratory purposes. One group is the Enterobacteriaceae family of Gammaproteobacteria, which have their natural habitats in soil, marine environments or the intestines of humans and other warm-blooded animals. Some of the genera are pathogenic and usually associated with intestinal infections. Our body possesses several physical and chemical defence mechanisms to prevent pathogenic enteric bacteria from invading the gastrointestinal tract. One response of the innate immune system is to activate macrophages, which produce the potent cytotoxin nitric oxide (NO). However, some pathogens have evolved the ability to detoxify NO to less toxic compounds, such as the neuropharmacological agent and greenhouse gas nitrous oxide (N₂O), which enables them to overcome the host's attack. The same mechanisms may be used by bacteria producing NO endogenously as a by-product of anaerobic nitrate respiration. In the present review, we provide a brief introduction into the NO detoxification mechanisms of two members of the Enterobacteriaceae family: Escherichia coli and Salmonella enterica serovar Typhimurium. These are discussed as comparative non-pathogenic and pathogenic model systems in order to investigate the importance of detoxifying NO and producing N₂O for the pathogenicity of enteric bacteria. PMID:22103543

  9. Flies as a source of enteric pathogens in a rural village in Thailand.

    PubMed Central

    Echeverria, P; Harrison, B A; Tirapat, C; McFarland, A

    1983-01-01

    The village of Ban Pong in northeastern Thailand was studied from January through December 1981 to determine the importance of flies as a source of enteric pathogens. The number of flies (predominantly Musca domestica) increased in kitchens and animal pens in the hot dry spring, when the incidence of diarrhea was highest in the village. Enterotoxigenic Escherichia coli, Shigella spp., non-O1 Vibrio cholerae, and Vibrio fluvalis were isolated from fly pools in yards (69%), animal pens (38%), bathrooms (35%), and kitchens (8%). Enterotoxigenic E. coli was isolated from one fly pool in May and from another in June, when the incidence of such infections was highest in the village. Flies often carry and presumably disseminate enteric pathogens in rural Thailand. PMID:6351748

  10. Enteric pathogen survival varies substantially in irrigation water from Belgian lettuce producers.

    PubMed

    Van Der Linden, Inge; Cottyn, Bart; Uyttendaele, Mieke; Berkvens, Nick; Vlaemynck, Geertrui; Heyndrickx, Marc; Maes, Martine

    2014-01-01

    It is accepted that irrigation water is a potential carrier of enteric pathogens, such as Salmonella and E. coli O157:H7 and, therefore, a source for contamination of fresh produce. We tested this by comparing irrigation water samples taken from five different greenhouses in Belgium. The water samples were inoculated with four zoonotic strains, two Salmonella and two E. coli O157:H7 strains, and pathogen survival and growth in the water were monitored up till 14 days. The influence of water temperature and chemical water quality was evaluated, and the survival tests were also performed in water samples from which the resident aquatic microbiota had previously been eliminated by filter sterilization. The pathogen's survival differed greatly in the different irrigation waters. Three water samples contained nutrients to support important growth of the pathogens, and another enabled weaker growth. However, for all, growth was only observed in the samples that did not contain the resident aquatic microbiota. In the original waters with their specific water biota, pathogen levels declined. The same survival tendencies existed in water of 4 °C and 20 °C, although always more expressed at 20 °C. Low water temperatures resulted in longer pathogen survival. Remarkably, the survival capacity of two E. coli 0157:H7 strains differed, while Salmonella Thompson and Salmonella Typhimurium behaved similarly. The pathogens were also transferred to detached lettuce leaves, while suspended in two of the water samples or in a buffer. The effect of the water sample on the pathogen's fitness was also reproduced on the leaves when stored at 100% relative humidity. Inoculation of the suspension in buffer or in one of the water samples enabled epiphytic growth and survival, while the pathogen level in the other water sample decreased once loaded on the leaves. Our results show that irrigation waters from different origin may have a different capacity to transmit enteric pathogens and an

  11. Ranking freshwater fish farms for the risk of pathogen introduction and spread.

    PubMed

    Oidtmann, B C; Crane, C N; Thrush, M A; Hill, B J; Peeler, E J

    2011-12-15

    A semi-quantitative model is presented to rank freshwater rainbow trout farms within a country or region with regards to the risk of becoming infected and spreading a specified pathogen. The model was developed to support a risk-based surveillance scheme for notifiable salmonid pathogens. Routes of pathogen introduction and spread were identified through a process of expert consultation in a series of workshops. The routes were combined into themes (e.g. exposure via water, mechanical transmission). Themes were weighted based on expert opinion. Risk factors for each route were scored and combined into a theme score which was adjusted by the weight. The number of sources and consignments were used to assess introduction via live fish movements onto the farm. Biosecurity measures were scored to assess introduction on fomites. Upstream farms, wild fish and processing plants were included in assessing the likelihood of introduction by water. The scores for each theme were combined to give separate risk scores for introduction and spread. A matrix was used to combine these to give an overall risk score. A case study for viral haemorrhagic septicaemia is presented. Nine farms that represent a range of farming practices of rainbow trout farms in England and Wales are used as worked examples of the model. The model is suited to risk rank freshwater salmonid farms which are declared free of the pathogen(s) under consideration. The score allocated to a farm does not equate to a quantitative probability estimate of the farm to become infected or spread infection. Nevertheless, the method provides a transparent approach to ranking farms with regards to pathogen transmission risks. The output of the model at a regional or national level allows the allocation of surveillance effort to be risk based. It also provides fish farms with information on how they can reduce their risk score by improving biosecurity. The framework of the model can be applied to different production

  12. Diet and Environment Shape Fecal Bacterial Microbiota Composition and Enteric Pathogen Load of Grizzly Bears

    PubMed Central

    Schwab, Clarissa; Cristescu, Bogdan; Northrup, Joseph M.; Stenhouse, Gordon B.; Gänzle, Michael

    2011-01-01

    Background Diet and environment impact the composition of mammalian intestinal microbiota; dietary or health disturbances trigger alterations in intestinal microbiota composition and render the host susceptible to enteric pathogens. To date no long term monitoring data exist on the fecal microbiota and pathogen load of carnivores either in natural environments or in captivity. This study investigates fecal microbiota composition and the presence of pathogenic Escherichia coli and toxigenic clostridia in wild and captive grizzly bears (Ursus arctos) and relates these to food resources consumed by bears. Methodology/Principal Findings Feces were obtained from animals of two wild populations and from two captive animals during an active bear season. Wild animals consumed a diverse diet composed of plant material, animal prey and insects. Captive animals were fed a regular granulated diet with a supplement of fruits and vegetables. Bacterial populations were analyzed using quantitative PCR. Fecal microbiota composition fluctuated in wild and in captive animals. The abundance of Clostridium clusters I and XI, and of C. perfringens correlated to regular diet protein intake. Enteroaggregative E. coli were consistently present in all populations. The C. sordellii phospholipase C was identified in three samples of wild animals and for the first time in Ursids. Conclusion This is the first longitudinal study monitoring the fecal microbiota of wild carnivores and comparing it to that of captive individuals of the same species. Location and diet affected fecal bacterial populations as well as the presence of enteric pathogens. PMID:22194798

  13. Fully integrated multiplexed lab-on-a-card assay for enteric pathogens

    NASA Astrophysics Data System (ADS)

    Weigl, B. H.; Gerdes, J.; Tarr, P.; Yager, P.; Dillman, L.; Peck, R.; Ramachandran, S.; Lemba, M.; Kokoris, M.; Nabavi, M.; Battrell, F.; Hoekstra, D.; Klein, E. J.; Denno, D. M.

    2006-01-01

    Under this NIH-funded project, we are developing a lab-on-a-card platform to identify enteric bacterial pathogens in patients presenting with acute diarrhea, with special reference to infections that might be encountered in developing countries. Component functions that are integrated on this platform include on-chip immunocapture of live or whole pathogens, multiplexed nucleic acid amplification and on-chip detection, sample processing to support direct use of clinical specimens, and dry reagent storage and handling. All microfluidic functions are contained on the lab card. This new diagnostic test will be able to rapidly identify and differentiate Shigella dysenteriae serotype 1, Shigella toxin-producing Escherichia coli, E. coli 0157, Campylobacter jejuni, and Salmonella and Shigella species. This presentation will report on progress to date on sample and bacteria processing methodologies, identification and validation of capture antibodies and strategy for organism immunocapture, identification and validation of specific polymerase chain reaction (PCR) primer sequences for over 200 clinical isolates of enteric pathogens, and implementation of on-chip nucleic acid extraction for a subset of those pathogens.

  14. Biofilm formation by enteric pathogens and its role in plant colonization and persistence

    PubMed Central

    Yaron, Sima; Römling, Ute

    2014-01-01

    The significant increase in foodborne outbreaks caused by contaminated fresh produce, such as alfalfa sprouts, lettuce, melons, tomatoes and spinach, during the last 30 years stimulated investigation of the mechanisms of persistence of human pathogens on plants. Emerging evidence suggests that Salmonella enterica and Escherichia coli, which cause the vast majority of fresh produce outbreaks, are able to adhere to and to form biofilms on plants leading to persistence and resistance to disinfection treatments, which subsequently can cause human infections and major outbreaks. In this review, we present the current knowledge about host, bacterial and environmental factors that affect the attachment to plant tissue and the process of biofilm formation by S. enterica and E. coli, and discuss how biofilm formation assists in persistence of pathogens on the plants. Mechanisms used by S. enterica and E. coli to adhere and persist on abiotic surfaces and mammalian cells are partially similar and also used by plant pathogens and symbionts. For example, amyloid curli fimbriae, part of the extracellular matrix of biofilms, frequently contribute to adherence and are upregulated upon adherence and colonization of plant material. Also the major exopolysaccharide of the biofilm matrix, cellulose, is an adherence factor not only of S. enterica and E. coli, but also of plant symbionts and pathogens. Plants, on the other hand, respond to colonization by enteric pathogens with a variety of defence mechanisms, some of which can effectively inhibit biofilm formation. Consequently, plant compounds might be investigated for promising novel antibiofilm strategies. PMID:25351039

  15. Enteric pathogen exploitation of the microbiota-generated nutrient environment of the gut.

    PubMed

    Keeney, Kristie M; Finlay, B Brett

    2011-02-01

    Residing within the intestine is a large community of commensal organisms collectively termed the microbiota. This community generates a complex nutrient environment by breaking down indigestible food products into metabolites that are used by both the host and the microbiota. Both the invading intestinal pathogen and the microbiota compete for these metabolites, which can shape both the composition of the flora, as well as susceptibility to infection. After infection is established, pathogen mediated inflammation alters the composition of the microbiota, which further shifts the makeup of metabolites in the gastrointestinal tract. A greater understanding of the interplay between the microbiota, the metabolites they generate, and susceptibility to enteric disease will enable the discovery of novel therapies against infectious disease. PMID:21215681

  16. Comparative metagenomic analysis of the enteric viromes from specific-pathogen free (SPF) chickens placed on broiler farms with enteric disease signs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metagenomics approaches have identified novel viruses in the poultry gastrointestinal tract, but these viruses and viral communities and their roles in general gut health have not been fully characterized. This study investigates the colonization of specific pathogen free (SPF) chickens by enteric v...

  17. The occurrence of enteric pathogens and Aeromonas species in organic vegetables.

    PubMed

    McMahon, M A; Wilson, I G

    2001-10-22

    A range of commercially available organic vegetables (n = 86) was examined for the presence of Salmonella, Campylobacter, Escherichia coli, E. coli O 157. Listeria and Aeromonas spp., to provide information on the occurrence of such organisms in organic vegetables in Northern Ireland. The study was not designed to quantify such organisms or to compare occurrence with conventionally farmed vegetables. Standard enrichment techniques were used to isolate and identify enteric pathogens and Aeromonas species. No Salmonella, Campylobacter, E. coli. E. coli O 157, Listeria were found in any of the samples examined. Aeromonas species were isolated from 34% of the total number of organic vegetables examined. Many (64%) of the organic vegetables examined were "ready-to-eat" after minimal processing, i.e., washing. Aeromonas spp. was isolated from 41% of these vegetables. Aeromonas spp. was not recovered from certain vegetable types. The most commonly isolated species of Aeromonas was Aeromonas schubertii with 21.0% of all samples contaminated with this species; 5.8% of samples contained A. hydrophila, 5.8% A. trota, 3.5% A. caviae and 2.3% contained A. veronii biovar veronii. Although Aeromonas species are frequently detected in organic vegetables, the absence of accepted enteric pathogens was encouraging, and does not support the allegation of organic foods being of high risk due to the farming methods used. PMID:11759753

  18. Biofilm formation by enteric pathogens and its role in plant colonization and persistence.

    PubMed

    Yaron, Sima; Römling, Ute

    2014-11-01

    The significant increase in foodborne outbreaks caused by contaminated fresh produce, such as alfalfa sprouts, lettuce, melons, tomatoes and spinach, during the last 30 years stimulated investigation of the mechanisms of persistence of human pathogens on plants. Emerging evidence suggests that Salmonella enterica and Escherichia coli, which cause the vast majority of fresh produce outbreaks, are able to adhere to and to form biofilms on plants leading to persistence and resistance to disinfection treatments, which subsequently can cause human infections and major outbreaks. In this review, we present the current knowledge about host, bacterial and environmental factors that affect the attachment to plant tissue and the process of biofilm formation by S. enterica and E. coli, and discuss how biofilm formation assists in persistence of pathogens on the plants. Mechanisms used by S. enterica and E. coli to adhere and persist on abiotic surfaces and mammalian cells are partially similar and also used by plant pathogens and symbionts. For example, amyloid curli fimbriae, part of the extracellular matrix of biofilms, frequently contribute to adherence and are upregulated upon adherence and colonization of plant material. Also the major exopolysaccharide of the biofilm matrix, cellulose, is an adherence factor not only of S. enterica and E. coli, but also of plant symbionts and pathogens. Plants, on the other hand, respond to colonization by enteric pathogens with a variety of defence mechanisms, some of which can effectively inhibit biofilm formation. Consequently, plant compounds might be investigated for promising novel antibiofilm strategies. PMID:25351039

  19. Bacterial Adrenergic Sensors Regulate Virulence of Enteric Pathogens in the Gut

    PubMed Central

    Moreira, Cristiano G.; Russell, Regan; Mishra, Animesh Anand; Narayanan, Sanjeev; Ritchie, Jennifer M.; Waldor, Matthew K.; Curtis, Meredith M.; Weinshenker, David

    2016-01-01

    ABSTRACT Enteric pathogens such as enterohemorrhagic Escherichia coli (EHEC) and Citrobacter rodentium, which is largely used as a surrogate EHEC model for murine infections, are exposed to several host neurotransmitters in the gut. An important chemical exchange within the gut involves the neurotransmitters epinephrine and/or norepinephrine, extensively reported to increase virulence gene expression in EHEC, acting through two bacterial adrenergic sensors: QseC and QseE. However, EHEC is unable to establish itself and cause its hallmark lesions, attaching and effacing (AE) lesions, on murine enterocytes. To address the role of these neurotransmitters during enteric infection, we employed C. rodentium. Both EHEC and C. rodentium harbor the locus of enterocyte effacement (LEE) that is necessary for AE lesion formation. Here we show that expression of the LEE, as well as that of other virulence genes in C. rodentium, is also activated by epinephrine and/or norepinephrine. Both QseC and QseE are required for LEE gene activation in C. rodentium, and the qseC and qseE mutants are attenuated for murine infection. C. rodentium has a decreased ability to colonize dopamine β-hydroxylase knockout (Dbh−/−) mice, which do not produce epinephrine and norepinephrine. Both adrenergic sensors are required for C. rodentium to sense these neurotransmitters and activate the LEE genes during infection. These data indicate that epinephrine and norepinephrine are sensed by bacterial adrenergic receptors during enteric infection to promote activation of their virulence repertoire. This is the first report of the role of these neurotransmitters during mammalian gastrointestinal (GI) infection by a noninvasive pathogen. PMID:27273829

  20. Pathogenic Enteric Viruses and Microbial Indicators during Secondary Treatment of Municipal Wastewater

    PubMed Central

    Montazeri, Naim; Goettert, Dorothee; Achberger, Eric C.; Johnson, Crystal N.; Prinyawiwatkul, Witoon

    2015-01-01

    Pathogenic enteric viruses are responsible for a wide range of infections in humans, with diverse symptoms. Raw and partially treated wastewaters are major sources of environmental contamination with enteric viruses. We monitored a municipal secondary wastewater treatment plant (New Orleans, LA) on a monthly basis for norovirus (NoV) GI and GII and enterovirus serotypes using multiplex reverse transcription-quantitative PCR (RT-qPCR) and microbial indicators of fecal contamination using standard plating methods. Densities of indicator bacteria (enterococci, fecal coliforms, and Escherichia coli) did not show monthly or seasonal patterns. Norovirus GII was more abundant than GI and, along with enterovirus serotypes, increased in influent during fall and spring. The highest NoV GI density in influent was in the fall, reaching an average of 4.0 log10 genomic copies/100 ml. Norovirus GI removal (0.95 log10) was lower than that for GII, enterovirus serotypes, and male-specific coliphages (1.48 log10) or for indicator bacteria (4.36 log10), suggesting higher resistance of viruses to treatment. Male-specific coliphages correlated with NoV GII densities in influent and effluent (r = 0.48 and 0.76, respectively) and monthly removal, indicating that male-specific coliphages can be more reliable than indicator bacteria to monitor norovirus GII load and microbial removal. Dominant norovirus genotypes were classified into three GI genotypes (GI.1, GI.3, and GI.4) and four GII genotypes (GII.3, GII.4, GII.13, and GII.21), dominated by GI.1 and GII.4 strains. Some of the seasonal and temporal patterns we observed in the pathogenic enteric viruses were different from those of epidemiological observations. PMID:26162869

  1. The Roles of Inflammation, Nutrient Availability and the Commensal Microbiota in Enteric Pathogen Infection.

    PubMed

    Stecher, Bärbel

    2015-06-01

    The healthy human intestine is colonized by as many as 1014 bacteria belonging to more than 500 different species forming a microbial ecosystem of unsurpassed diversity, termed the microbiota. The microbiota's various bacterial members engage in a physiological network of cooperation and competition within several layers of complexity. Within the last 10 years, technological progress in the field of next-generation sequencing technologies has tremendously advanced our understanding of the wide variety of physiological and pathological processes that are influenced by the commensal microbiota (1, 2). An increasing number of human disease conditions, such as inflammatory bowel diseases (IBD), type 2 diabetes, obesity, allergies and colorectal cancer are linked with altered microbiota composition (3). Moreover, a clearer picture is emerging of the composition of the human microbiota in healthy individuals, its variability over time and between different persons and how the microbiota is shaped by environmental factors (i.e., diet) and the host's genetic background (4). A general feature of a normal, healthy gut microbiota can generate conditions in the gut that disfavor colonization of enteric pathogens. This is termed colonization-resistance (CR). Upon disturbance of the microbiota, CR can be transiently disrupted, and pathogens can gain the opportunity to grow to high levels. This disruption can be caused by exposure to antibiotics (5, 6), changes in diet (7, 8), application of probiotics and drugs (9), and a variety of diseases (3). Breakdown of CR can boost colonization by intrinsic pathogens or increase susceptibility to infections (10). One consequence of pathogen expansion is the triggering of inflammatory host responses and pathogen-mediated disease. Interestingly, human enteric pathogens are part of a small group of bacterial families that belong to the Proteobacteria: the Enterobacteriaceae (E. coli, Yersinia spp., Salmonella spp., Shigella spp.), the

  2. Toward a Systems Approach to Enteric Pathogen Transmission: From Individual Independence to Community Interdependence

    PubMed Central

    Eisenberg, Joseph N.S.; Trostle, James; Sorensen, Reed J.D.; Shields, Katherine F.

    2012-01-01

    Diarrheal disease is still a major cause of mortality and morbidity worldwide; thus a large body of research has been produced describing its risks. We review more than four decades of literature on diarrheal disease epidemiology. These studies detail a progression in the conceptual understanding of transmission of enteric pathogens and demonstrate that diarrheal disease is caused by many interdependent pathways. However, arguments by diarrheal disease researchers in favor of attending to interaction and interdependencies have only recently yielded more formal systems-level approaches. Therefore, interdependence has not yet been highlighted in significant new research initiatives or policy decisions. We argue for a systems-level framework that will contextualize transmission and inform prevention and control efforts so that they can integrate transmission pathways. These systems approaches should be employed to account for community effects (i.e., interactions among individuals and/or households). PMID:22224881

  3. Distribution and antimicrobial resistance of enteric pathogens in Chinese paediatric diarrhoea: a multicentre retrospective study, 2008-2013.

    PubMed

    Zhang, H; Pan, F; Zhao, X; Wang, G; Tu, Y; Fu, S; Wang, J; Pan, J; Song, J; Wang, W; Jin, Z; Xu, H; Ren, Y; Li, Y; Zhong, N

    2015-09-01

    The enteric pathogens causing diarrhoea impair children's health severely. This study retrospectively analysed 1577 pathogens isolated from inpatients and outpatients in six hospitals located in Northern (Inner Mongolia), Northeastern (Hebei), Eastern (Shanghai and Jiangsu), Southern (Hainan) and Central (Hubei) China between 2008 and 2013. Of the 1577 enteric pathogens, Salmonella presented with the highest frequency (36·0%), followed by diarrhoeagenic Escherichia coli (23·7%), Staphylococcus aureus (15·0%), Shigella (13·1%), and Aeromonas (4·6%). The predominant pathogens varied in different regions of China, with Salmonella most prevalent in Shanghai and Hainan, diarrhoeagenic E. coli most prevalent in Inner Mongolia, Jiangsu and Hubei, and Shigella most prevalent in Hebei. Enteric pathogens were more frequently isolated in males (56·9%) than in females (43·1%). The highest proportion of all enteric pathogens was found in infants (67·6%) with a peak in summer and autumn (68·5%). Antimicrobial susceptibility assay demonstrated that Shigella was more resistant to ampicillin, ceftriaxone and sulfamethoxazole than Salmonella. Of the top two serotypes in Salmonella, Typhimurium was more resistant to ciprofloxacin, sulfamethoxazole and chloramphenicol than Enteritidis (P < 0·001). Meanwhile, the resistance rates of Shigella flexneri against ampicillin/sulbactam, ciprofloxacin, and chloramphenicol were significantly higher than those of Shigella sonnei (P < 0·001). Multidrug resistance was apparent in 58·2% of Shigella and 45·9% of Salmonella, and this phenomenon was more pronounced in S. flexneri. PMID:25586929

  4. Enteric Pathogen-Plant Interactions: Molecular Connections Leading to Colonization and Growth and Implications for Food Safety

    PubMed Central

    Martínez-Vaz, Betsy M.; Fink, Ryan C.; Diez-Gonzalez, Francisco; Sadowsky, Michael J.

    2014-01-01

    Leafy green vegetables have been identified as a source of foodborne illnesses worldwide over the past decade. Human enteric pathogens, such as Escherichia coli O157:H7 and Salmonella, have been implicated in numerous food poisoning outbreaks associated with the consumption of fresh produce. An understanding of the mechanisms responsible for the establishment of pathogenic bacteria in or on vegetable plants is critical for understanding and ameliorating this problem as well as ensuring the safety of our food supply. While previous studies have described the growth and survival of enteric pathogens in the environment and also the risk factors associated with the contamination of vegetables, the molecular events involved in the colonization of fresh produce by enteric pathogens are just beginning to be elucidated. This review summarizes recent findings on the interactions of several bacterial pathogens with leafy green vegetables. Changes in gene expression linked to the bacterial attachment and colonization of plant structures are discussed in light of their relevance to plant-microbe interactions. We propose a mechanism for the establishment and association of enteric pathogens with plants and discuss potential strategies to address the problem of foodborne illness linked to the consumption of leafy green vegetables. PMID:24859308

  5. Enteric pathogens deploy cell cycle inhibiting factors to block the bactericidal activity of Perforin-2

    PubMed Central

    McCormack, Ryan M; Lyapichev, Kirill; Olsson, Melissa L; Podack, Eckhard R; Munson, George P

    2015-01-01

    Perforin-2 (MPEG1) is an effector of the innate immune system that limits the proliferation and spread of medically relevant Gram-negative, -positive, and acid fast bacteria. We show here that a cullin-RING E3 ubiquitin ligase (CRL) complex containing cullin-1 and βTrCP monoubiquitylates Perforin-2 in response to pathogen associated molecular patterns such as LPS. Ubiquitylation triggers a rapid redistribution of Perforin-2 and is essential for its bactericidal activity. Enteric pathogens such as Yersinia pseudotuberculosis and enteropathogenic Escherichia coli disarm host cells by injecting cell cycle inhibiting factors (Cifs) into mammalian cells to deamidate the ubiquitin-like protein NEDD8. Because CRL activity is dependent upon NEDD8, Cif blocks ubiquitin dependent trafficking of Perforin-2 and thus, its bactericidal activity. Collectively, these studies further underscore the biological significance of Perforin-2 and elucidate critical molecular events that culminate in Perforin-2-dependent killing of both intracellular and extracellular, cell-adherent bacteria. DOI: http://dx.doi.org/10.7554/eLife.06505.001 PMID:26418746

  6. Identification of Novel Pathogenicity Loci in Clostridium perfringens Strains That Cause Avian Necrotic Enteritis

    PubMed Central

    Parreira, Valeria R.; Marri, Pradeep R.; Rosey, Everett L.; Gong, Joshua; Songer, J. Glenn; Vedantam, Gayatri; Prescott, John F.

    2010-01-01

    Type A Clostridium perfringens causes poultry necrotic enteritis (NE), an enteric disease of considerable economic importance, yet can also exist as a member of the normal intestinal microbiota. A recently discovered pore-forming toxin, NetB, is associated with pathogenesis in most, but not all, NE isolates. This finding suggested that NE-causing strains may possess other virulence gene(s) not present in commensal type A isolates. We used high-throughput sequencing (HTS) technologies to generate draft genome sequences of seven unrelated C. perfringens poultry NE isolates and one isolate from a healthy bird, and identified additional novel NE-associated genes by comparison with nine publicly available reference genomes. Thirty-one open reading frames (ORFs) were unique to all NE strains and formed the basis for three highly conserved NE-associated loci that we designated NELoc-1 (42 kb), NELoc-2 (11.2 kb) and NELoc-3 (5.6 kb). The largest locus, NELoc-1, consisted of netB and 36 additional genes, including those predicted to encode two leukocidins, an internalin-like protein and a ricin-domain protein. Pulsed-field gel electrophoresis (PFGE) and Southern blotting revealed that the NE strains each carried 2 to 5 large plasmids, and that NELoc-1 and -3 were localized on distinct plasmids of sizes ∼85 and ∼70 kb, respectively. Sequencing of the regions flanking these loci revealed similarity to previously characterized conjugative plasmids of C. perfringens. These results provide significant insight into the pathogenetic basis of poultry NE and are the first to demonstrate that netB resides in a large, plasmid-encoded locus. Our findings strongly suggest that poultry NE is caused by several novel virulence factors, whose genes are clustered on discrete pathogenicity loci, some of which are plasmid-borne. PMID:20532244

  7. Identification of novel pathogenicity loci in Clostridium perfringens strains that cause avian necrotic enteritis.

    PubMed

    Lepp, Dion; Roxas, Bryan; Parreira, Valeria R; Marri, Pradeep R; Rosey, Everett L; Gong, Joshua; Songer, J Glenn; Vedantam, Gayatri; Prescott, John F

    2010-01-01

    Type A Clostridium perfringens causes poultry necrotic enteritis (NE), an enteric disease of considerable economic importance, yet can also exist as a member of the normal intestinal microbiota. A recently discovered pore-forming toxin, NetB, is associated with pathogenesis in most, but not all, NE isolates. This finding suggested that NE-causing strains may possess other virulence gene(s) not present in commensal type A isolates. We used high-throughput sequencing (HTS) technologies to generate draft genome sequences of seven unrelated C. perfringens poultry NE isolates and one isolate from a healthy bird, and identified additional novel NE-associated genes by comparison with nine publicly available reference genomes. Thirty-one open reading frames (ORFs) were unique to all NE strains and formed the basis for three highly conserved NE-associated loci that we designated NELoc-1 (42 kb), NELoc-2 (11.2 kb) and NELoc-3 (5.6 kb). The largest locus, NELoc-1, consisted of netB and 36 additional genes, including those predicted to encode two leukocidins, an internalin-like protein and a ricin-domain protein. Pulsed-field gel electrophoresis (PFGE) and Southern blotting revealed that the NE strains each carried 2 to 5 large plasmids, and that NELoc-1 and -3 were localized on distinct plasmids of sizes approximately 85 and approximately 70 kb, respectively. Sequencing of the regions flanking these loci revealed similarity to previously characterized conjugative plasmids of C. perfringens. These results provide significant insight into the pathogenetic basis of poultry NE and are the first to demonstrate that netB resides in a large, plasmid-encoded locus. Our findings strongly suggest that poultry NE is caused by several novel virulence factors, whose genes are clustered on discrete pathogenicity loci, some of which are plasmid-borne. PMID:20532244

  8. Guanylate cyclase C limits systemic dissemination of a murine enteric pathogen

    PubMed Central

    2013-01-01

    Background Guanylate Cyclase C (GC-C) is an apically-oriented transmembrane receptor that is expressed on epithelial cells of the intestine. Activation of GC-C by the endogenous ligands guanylin or uroguanylin elevates intracellular cGMP and is implicated in intestinal ion secretion, cell proliferation, apoptosis, intestinal barrier function, as well as the susceptibility of the intestine to inflammation. Our aim was to determine if GC-C is required for host defense during infection by the murine enteric pathogen Citrobacter rodentium of the family Enterobacteriacea. Methods GC-C+/+ control mice or those having GC-C genetically ablated (GC-C−/−) were administered C. rodentium by orogastric gavage and analyzed at multiple time points up to post-infection day 20. Commensal bacteria were characterized in uninfected GC-C+/+ and GC-C−/− mice using 16S rRNA PCR analysis. Results GC-C−/− mice had an increase in C. rodentium bacterial load in stool relative to GC-C+/+. C. rodentium infection strongly decreased guanylin expression in GC-C+/+ mice and, to an even greater degree, in GC-C−/− animals. Fluorescent tracer studies indicated that mice lacking GC-C, unlike GC-C+/+ animals, had a substantial loss of intestinal barrier function early in the course of infection. Epithelial cell apoptosis was significantly increased in GC-C−/− mice following 10 days of infection and this was associated with increased frequency and numbers of C. rodentium translocation out of the intestine. Infection led to significant liver histopathology in GC-C−/− mice as well as lymphocyte infiltration and elevated cytokine and chemokine expression. Relative to naïve GC-C+/+ mice, the commensal microflora load in uninfected GC-C−/− mice was decreased and bacterial composition was imbalanced and included outgrowth of the Enterobacteriacea family. Conclusions This work demonstrates the novel finding that GC-C signaling is an essential component of host defense during

  9. Prevalence and Characteristics of Enteric Pathogens Detected in Diarrhoeic and Non-Diarrhoeic Foals in Trinidad

    PubMed Central

    Harris, Robin; Sankar, Kerri; Small, Julie-Anne; Suepaul, Rod; Stewart-Johnson, Alva; Adesiyun, Abiodun

    2012-01-01

    The study determined the relative importance of Escherichia coli, E. coli O157, Salmonella spp., Clostridium spp., rotavirus, Cryptosporidium spp., and Strongyloides westeri in foal (diarrhoeic and non-diarrhoeic) available for sampling during the foaling season of 2010 and determined their sensitivity to antimicrobial agents. A cross-sectional study was conducted on 164 foals (9 diarrhoeic and 155 non-diarrhoeic) from 15 farms in Trinidad. Isolation and detection of enteric pathogens followed standard methods, and the antibiograms of E. coli and Salmonella spp. were determined using the disc diffusion method. All organisms investigated were detected except E. coli O157. A high prevalence of E. coli (85.0%), Cryptosporidium spp. (64.8%), Strongyloides westeri (35.7%) was seen, but the prevalence was comparatively low for Clostridium spp. (12.9%), Salmonella spp. (4.4%) and rotavirus (2.1%). Only Salmonella spp. was isolated at a statistically significantly (P < 0.05; χ2) higher frequency from diarrhoeic (25.0%) than non-diarrhoeic (4.0%) foals. Amongst E. coli isolates, the frequency of resistance was higher in isolates from diarrhoeic compared with non-diarrhoeic foals but the difference was only statistically significant (P < 0.05; χ2) for tetracycline. All isolates of Salmonella spp. were sensitive to streptomycin and sulphamethoxazole/trimethoprim, a finding that may have therapeutic significance. PMID:22792513

  10. 2013 European Guideline on the management of proctitis, proctocolitis and enteritis caused by sexually transmissible pathogens.

    PubMed

    de Vries, Henry J C; Zingoni, Adele; White, John A; Ross, Jonathan D C; Kreuter, Alexander

    2014-06-01

    Proctitis is defined as an inflammatory syndrome of the distal 10-12 cm of the anal canal, also called the rectum. Infectious proctitis can be sexually transmitted via genital-anal mucosal contact, but some also via mutual masturbation.N. gonorrhoeae,C. trachomatis(including lymphogranuloma venereum), Herpes Simplex Virus andT. pallidumare the most common sexually transmitted anorectal pathogens. Shigellosis can be transferred via oral-anal contact and may lead to proctocolitis or enteritis. Although most studies on these infections have concentrated on men who have sex with men (MSM), a significant proportion of women have anal intercourse and therefore may also be at risk. A presumptive clinical diagnosis of proctitis can be made when there are symptoms and signs, and a definitive diagnosis when the results of laboratory tests are available. The symptoms of proctitis include anorectal itching, pain, cramps (tenesmus) and discharge in and around the anal canal. Asymptomatic proctitis occurs frequently and can only be detected by laboratory tests. The majority of rectal chlamydia and gonococcal infections are asymptomatic. Therefore when there is a history of receptive anal contact, exclusion of anorectal infections is generally indicated as part of standard screening for sexually transmitted infections (STIs). Condom use does not guarantee protection from bacterial and protozoan STIs, which are often spread without penile penetration. PMID:24352129

  11. Non-canonical inflammasome activation of caspase-4/caspase-11 mediates epithelial defenses against enteric bacterial pathogens

    PubMed Central

    Knodler, Leigh A.; Crowley, Shauna M.; Sham, Ho Pan; Yang, Hyungjun; Wrande, Marie; Ma, Caixia; Ernst, Robert K.; Steele-Mortimer, Olivia; Celli, Jean; Vallance, Bruce A.

    2014-01-01

    Summary Inflammasome-mediated host defenses have been extensively studied in innate immune cells. Whether inflammasomes function for innate defense in intestinal epithelial cells, which represent the first line of defense against enteric pathogens, remains unknown. We observed enhanced Salmonella enterica serovar Typhimurium colonization in the intestinal epithelium of caspase-11 deficient mice, but not at systemic sites. In polarized epithelial monolayers, siRNA-mediated depletion of caspase-4, a human orthologue of caspase-11, also led to increased bacterial colonization. Decreased rates of pyroptotic cell death, a host defense mechanism that extrudes S. Typhimurium infected cells from the polarized epithelium, accounted for increased pathogen burdens. The caspase-4 inflammasome also governs activation of the proinflammatory cytokine, interleukin (IL)-18, in response to intracellular (S. Typhimurium) and extracellular (enteropathogenic Escherichia coli) enteric pathogens, via intracellular LPS sensing. Therefore an epithelial cell intrinsic non-canonical inflammasome plays a critical role in antimicrobial defense at the intestinal mucosal surface. PMID:25121752

  12. Prevalence of Campylobacter spp. relative to other enteric pathogens in grow-finish pigs with diarrhea.

    PubMed

    Burrough, Eric; Terhorst, Samantha; Sahin, Orhan; Zhang, Qijing

    2013-08-01

    Salmonella spp., Lawsonia intracellularis, and Brachyspira spp. are pathogens commonly associated with diarrhea in growing and finishing pigs. Brachyspira spp. infection has recently reemerged as a significant concern due to an increase in the incidence of swine dysentery; however, the mechanisms underlying this increase in dysentery remain largely unknown. Pigs are also well-recognized as potential carriers of Campylobacter spp., particularly Campylobacter coli, yet enteric disease in swine associated with infection by these bacteria is considered uncommon and diagnosis has historically been based upon exclusion of other causes. Accordingly, Campylobacter culture is often excluded in routine diagnostic testing of cases of porcine enterocolitis and the incidence of infection is therefore largely unknown. In this study, feces from 155 cases of clinical diarrhea in grow-finish pigs submitted to the Iowa State University Veterinary Diagnostic Laboratory were cultured for Campylobacter spp. in addition to other testing as indicated for routine diagnostic investigation. Campylobacter culture was positive from 82.6% (128/155) of samples with C. coli accounting for 75% of isolates and Campylobacter jejuni for the remaining 25%. In 14.8% (23/155) of cases a Campylobacter spp. was the sole infectious agent detected; however, there was no association with any particular Campylobacter spp. Interestingly, for those cases with a laboratory diagnosis of Brachyspira-associated disease, 100% (15/15) were also culture positive for Campylobacter spp. suggesting a possible interrelationship between these bacteria in the pig gut. No association was noted between Campylobacter culture results and infection with either Salmonella spp. or L. intracellularis. PMID:23792232

  13. RAPID METHODS FOR DETECTION OF NON-ENTERIC PATHOGENS IN RECREATIONAL WATERS

    EPA Science Inventory

    Current microbial indicators of pathogen occurrence in various water media that EPA either regulates or provides health criteria for have been demonstrated to have deficiencies in providing an accurate assessment of pathogen occurrence. One reason is that current indicators are ...

  14. Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff.

    PubMed

    Miller, Melissa A; Byrne, Barbara A; Jang, Spencer S; Dodd, Erin M; Dorfmeier, Elene; Harris, Michael D; Ames, Jack; Paradies, David; Worcester, Karen; Jessup, David A; Miller, Woutrina A

    2010-01-01

    Although protected for nearly a century, California's sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored. Using selective media, we examined feces from live and dead sea otters from California for specific enteric bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C. difficile and Escherichia coli O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae, V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in otter feces and demographic or environmental risk factors for otter exposure, and found that dead otters were more likely to test positive for C. perfringens, Campylobacter and V. parahaemolyticus than were live otters. Otters from more urbanized coastlines and areas with high freshwater runoff (near outflows of rivers or streams) were more likely to test positive for one or more of these bacterial pathogens. Other risk factors for bacterial detection in otters included male gender and fecal samples collected during the rainy season when surface runoff is maximal. Similar risk factors were reported in prior studies of pathogen exposure for California otters and their invertebrate prey, suggesting that land-sea transfer and/or facilitation of pathogen survival in degraded coastal marine habitat may be impacting sea otter recovery. Because otters and humans share many of the same foods, our findings may also have implications for human health. PMID:19720009

  15. Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff

    PubMed Central

    Miller, Melissa A.; Byrne, Barbara A.; Jang, Spencer S.; Dodd, Erin M.; Dorfmeier, Elene; Harris, Michael D.; Ames, Jack; Paradies, David; Worcester, Karen; Jessup, David A.; Miller, Woutrina A.

    2009-01-01

    Although protected for nearly a century, California’s sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored. Using selective media, we examined feces from live and dead sea otters from California for specific enteric bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C. difficile and Escherichia coli O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae, V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in otter feces and demographic or environmental risk factors for otter exposure, and found that dead otters were more likely to test positive for C. perfringens, Campylobacter and V. parahaemolyticus than were live otters. Otters from more urbanized coastlines and areas with high freshwater runoff (near outflows of rivers or streams) were more likely to test positive for one or more of these bacterial pathogens. Other risk factors for bacterial detection in otters included male gender and fecal samples collected during the rainy season when surface runoff is maximal. Similar risk factors were reported in prior studies of pathogen exposure for California otters and their invertebrate prey, suggesting that land-sea transfer and/or facilitation of pathogen survival in degraded coastal marine habitat may be impacting sea otter recovery. Because otters and humans share many of the same foods, our findings may also have implications for human health. PMID:19720009

  16. High-Risk Enteric Pathogens Associated with HIV-Infection and HIV-Exposure in Kenyan Children with Acute Diarrhea

    PubMed Central

    PAVLINAC, PB; JOHN-STEWART, GC; NAULIKHA, JM; ONCHIRI, FM; DENNO, DM; ODUNDO, EA; SINGA, BO; RICHARDSON, BA; WALSON, JL

    2015-01-01

    Objective HIV-infection is an established risk for diarrheal severity, less is known about specific enteric pathogens associated with HIV status. We determined associations of selected enteric pathogens with HIV-infection and HIV-exposure among Kenyan children. Design Cross-sectional study among 6 months to 15 year olds presenting to two Western Kenya District hospitals with acute diarrhea between 2011–2013. Methods Stool was tested using standard bacterial culture and microscopy for ova and parasites. HIV testing was obtained on children and mothers. Enteric pathogen prevalence was compared between HIV-infected and HIV-uninfected children and between HIV-exposed uninfected (HEU) and HIV-unexposed. Unadjusted and adjusted prevalence ratios (PR) for selected pathogens by HIV-status were estimated using relative risk (RR) regression and P-values. Age, site, income, household crowding, water source/treatment, anthropometrics, cotrimoxazole use, and breastfeeding history were accounted for in multivariable models. Results Among 1,076 children, median age was 22 months (interquartile range: 11–42), 56 (5.2%) were HIV-infected, and 10.3%(105/1020) of HIV-uninfected children were HIV-exposed. The following organisms were most frequently isolated from stool: enteroaggregative Escherichia coli (13.3%), Giardia spp. (11.1%) Campylobacter (6.3%), enteropathogenic Escherichia coli (EPEC) (6.1%) and Cryptosporidium spp. (3.7%). Accounting for age, HIV-infection was associated with EPEC infection (PR: 3.70, P=0.002) while HIV-exposure was associated with Cryptosporidium among HIV-uninfected children (PR: 2.81, P=0.005). Conclusion EPEC and Cryptosporidium infections were more common in HIV-infected and HIV-exposed children, respectively. This could explain the increased mortality attributed to these pathogens in other studies. Interventions targeting EPEC and Cryptosporidium may reduce morbidity and mortality in high HIV-prevalence settings. PMID:25028987

  17. Administrative Process and Criteria Ranking for Drug Entering Health Insurance List in Iran-TOPSIS-Based Consensus Model

    PubMed Central

    Viyanchi, Amir; Rajabzadeh Ghatari, Ali; Rasekh, Hamid Reza; SafiKhani, HamidReza

    2016-01-01

    The purposes of our study were to identify a drug entry process, collect, and prioritize criteria for selecting drugs for the list of basic health insurance commitments to prepare an “evidence based reimbursement eligibility plan” in Iran. The 128 noticeable criteria were found when studying the health insurance systems of developed countries. Four parts (involving criteria) formed the first questionnaire: evaluation of evidences quality, clinical evaluation, economic evaluation, and managerial appraisal. The 85 experts (purposed sampling) were asked to mark the importance of each criterion from 1 to 100 as 1 representing the least and 100 the most important criterion and 45 out of them replied completely. Then, in the next questionnaire, we evaluated the 48 remainder criteria by the same45 participants under four sub-criteria (Cost calculation simplicity, Interpretability, Precision, and Updating capability of a criterion). After collecting the replies, the remainder criteria were ranked by TOPSIS method. Softwares “SPSS” 17 and Excel 2007 were used. The ranks of the five most important criteria which were found for drug approval based on TOPSIS are as follows: 1-domestic production (0.556), 2-duration of using (0.399), 3-independence of the assessment group (0.363) 4-impact budgeting (0.362) 5-decisions of other countries about the same drug (0.358). The numbers in parenthesis are relative closeness alternatives in relation to the ideal solution. This model gave a scientific model for judging fairly on the acceptance of novelty medicines. PMID:27610178

  18. Administrative Process and Criteria Ranking for Drug Entering Health Insurance List in Iran-TOPSIS-Based Consensus Model.

    PubMed

    Viyanchi, Amir; Rajabzadeh Ghatari, Ali; Rasekh, Hamid Reza; SafiKhani, HamidReza

    2016-01-01

    The purposes of our study were to identify a drug entry process, collect, and prioritize criteria for selecting drugs for the list of basic health insurance commitments to prepare an "evidence based reimbursement eligibility plan" in Iran. The 128 noticeable criteria were found when studying the health insurance systems of developed countries. Four parts (involving criteria) formed the first questionnaire: evaluation of evidences quality, clinical evaluation, economic evaluation, and managerial appraisal. The 85 experts (purposed sampling) were asked to mark the importance of each criterion from 1 to 100 as 1 representing the least and 100 the most important criterion and 45 out of them replied completely. Then, in the next questionnaire, we evaluated the 48 remainder criteria by the same45 participants under four sub-criteria (Cost calculation simplicity, Interpretability, Precision, and Updating capability of a criterion). After collecting the replies, the remainder criteria were ranked by TOPSIS method. Softwares "SPSS" 17 and Excel 2007 were used. The ranks of the five most important criteria which were found for drug approval based on TOPSIS are as follows: 1-domestic production (0.556), 2-duration of using (0.399), 3-independence of the assessment group (0.363) 4-impact budgeting (0.362) 5-decisions of other countries about the same drug (0.358). The numbers in parenthesis are relative closeness alternatives in relation to the ideal solution. This model gave a scientific model for judging fairly on the acceptance of novelty medicines. PMID:27610178

  19. Genomic paradigms for food-borne enteric pathogen analysis at the USFDA: case studies highlighting method utility, integration and resolution.

    PubMed

    Elkins, C A; Kotewicz, M L; Jackson, S A; Lacher, D W; Abu-Ali, G S; Patel, I R

    2013-01-01

    Modern risk control and food safety practices involving food-borne bacterial pathogens are benefiting from new genomic technologies for rapid, yet highly specific, strain characterisations. Within the United States Food and Drug Administration (USFDA) Center for Food Safety and Applied Nutrition (CFSAN), optical genome mapping and DNA microarray genotyping have been used for several years to quickly assess genomic architecture and gene content, respectively, for outbreak strain subtyping and to enhance retrospective trace-back analyses. The application and relative utility of each method varies with outbreak scenario and the suspect pathogen, with comparative analytical power enhanced by database scale and depth. Integration of these two technologies allows high-resolution scrutiny of the genomic landscapes of enteric food-borne pathogens with notable examples including Shiga toxin-producing Escherichia coli (STEC) and Salmonella enterica serovars from a variety of food commodities. Moreover, the recent application of whole genome sequencing technologies to food-borne pathogen outbreaks and surveillance has enhanced resolution to the single nucleotide scale. This new wealth of sequence data will support more refined next-generation custom microarray designs, targeted re-sequencing and "genomic signature recognition" approaches involving a combination of genes and single nucleotide polymorphism detection to distil strain-specific fingerprinting to a minimised scale. This paper examines the utility of microarrays and optical mapping in analysing outbreaks, reviews best practices and the limits of these technologies for pathogen differentiation, and it considers future integration with whole genome sequencing efforts. PMID:23199033

  20. Incidence of enteric bacterial pathogens in water found at the bottom of commercial freezers in calabar, southeastern Nigeria.

    PubMed

    Eja, Matthew Egbobor; Etok, Comfort A; Asikong, Bassey E; Mboto, Clement I; Arikpo, Giddings E

    2006-03-01

    Bacteriological analysis of water that accumulates at the bottom of freezers in restaurants when the power was cut in Calabar, southeastern Nigeria, was carried out using standard procedures. Mean heterotrophic bacterial counts and Escherichia coli counts ranged from 3.1 +/- 0.02 to 7.1 +/- 0.30 x 10(4) cfu/ml and 0.2 +/- 0.10 to 0.6 +/- 0.50 x 10(4) cfu/ml, respectively, indicating heavy bacterial contamination whose source was mostly fecal. There was no significant difference (p > 0.05, 0.01) in bacterial counts between freezers. Some biochemically identified enteric bacterial pathogens were Salmonella typhi, Shigella sp, enteropathogenic E. coli, Yersinia sp, Klebsiella pneumoniae, Vibrio cholerae O1 and Vibrio parahaemolyticus. This reveals that the hygienic quality of the food items stored in the freezers and the hygienic status of the restaurants are in doubt. Infection could be going on unnoticed and thus endemicity maintained in the area. The pathogens showed alarming antibiotic resistance. The water in the freezers was a "soup" in which different species of the enteric pathogens were close to each other and could transfer drug resistance among themselves. Public health education of restaurant operators in southeastern Nigeria is recommended. PMID:17125005

  1. Development of probiotic candidate in combination with essential oils from medicinal plant and their effect on enteric pathogens: a review.

    PubMed

    Shipradeep; Karmakar, Sourish; Sahay Khare, Rashmi; Ojha, Sumedha; Kundu, Kanika; Kundu, Subir

    2012-01-01

    Medicinal plants and probiotics both have very high potential in terms of their antimicrobial activity against antibiotic-resistant enteric pathogens. The probiotics being enteric microorganism do not have any parasitic effect on human beings. They have been an integral part of daily food for centuries. They have been shown to have health beneficiary properties. The probiotics retard the growth of the microorganisms, while essential oil kills them. Combining the effect of medicinal plant extract and probiotics may be a new approach due to their complementary antimicrobial effects and practically no side effects. The synergistic effect of the essential oil and probiotics will be necessarily higher than using them alone as health product. PMID:22811700

  2. Development of Probiotic Candidate in Combination with Essential Oils from Medicinal Plant and Their Effect on Enteric Pathogens: A Review

    PubMed Central

    Shipradeep; Karmakar, Sourish; Sahay Khare, Rashmi; Ojha, Sumedha; Kundu, Kanika; Kundu, Subir

    2012-01-01

    Medicinal plants and probiotics both have very high potential in terms of their antimicrobial activity against antibiotic-resistant enteric pathogens. The probiotics being enteric microorganism do not have any parasitic effect on human beings. They have been an integral part of daily food for centuries. They have been shown to have health beneficiary properties. The probiotics retard the growth of the microorganisms, while essential oil kills them. Combining the effect of medicinal plant extract and probiotics may be a new approach due to their complementary antimicrobial effects and practically no side effects. The synergistic effect of the essential oil and probiotics will be necessarily higher than using them alone as health product. PMID:22811700

  3. Probiotics as Natural Solutions to Enteric Pathogens with Organic Production Implications in Poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic poultry production has unique challenges; the lack of consistently effective treatments for enteric diseases can adversely influence bird health and the wholesomeness of poultry products. Drugs are not permitted in organic poultry production and mortality is often higher than conventional p...

  4. Inhibition of enteric pathogens using integrated high intensity 405 nm LED on the surface of almonds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The disinfecting properties of 405 nm light were investigated against Escherichia coli O157:H7, Salmonella, and their non-pathogenic surrogates inoculated onto the surface of almonds. High intensity monochromatic light was generated from an array of narrow-band 405 nm light emitting diodes (LED). Al...

  5. Strain competition restricts colonization of an enteric pathogen and prevents colitis.

    PubMed

    Hecht, Aaron L; Casterline, Benjamin W; Earley, Zachary M; Goo, Young Ah; Goodlett, David R; Bubeck Wardenburg, Juliane

    2016-09-01

    The microbiota is a major source of protection against intestinal pathogens; however, the specific bacteria and underlying mechanisms involved are not well understood. As a model of this interaction, we sought to determine whether colonization of the murine host with symbiotic non-toxigenic Bacteroides fragilis could limit acquisition of pathogenic enterotoxigenic B. fragilis We observed strain-specific competition with toxigenic B. fragilis, dependent upon type VI secretion, identifying an effector-immunity pair that confers pathogen exclusion. Resistance against host acquisition of a second non-toxigenic strain was also uncovered, revealing a broader function of type VI secretion systems in determining microbiota composition. The competitive exclusion of enterotoxigenic B. fragilis by a non-toxigenic strain limited toxin exposure and protected the host against intestinal inflammatory disease. Our studies demonstrate a novel role of type VI secretion systems in colonization resistance against a pathogen. This understanding of bacterial competition may be utilized to define a molecularly targeted probiotic strategy. PMID:27432285

  6. Canine Enteric Coronaviruses: Emerging Viral Pathogens with Distinct Recombinant Spike Proteins

    PubMed Central

    Licitra, Beth N.; Duhamel, Gerald E.; Whittaker, Gary R.

    2014-01-01

    Canine enteric coronavirus (CCoV) is an alphacoronavirus infecting dogs that is closely related to enteric coronaviruses of cats and pigs. While CCoV has traditionally caused mild gastro-intestinal clinical signs, there are increasing reports of lethal CCoV infections in dogs, with evidence of both gastrointestinal and systemic viral dissemination. Consequently, CCoV is now considered to be an emerging infectious disease of dogs. In addition to the two known serotypes of CCoV, novel recombinant variants of CCoV have been found containing spike protein N-terminal domains (NTDs) that are closely related to those of feline and porcine strains. The increase in disease severity in dogs and the emergence of novel CCoVs can be attributed to the high level of recombination within the spike gene that can occur during infection by more than one CCoV type in the same host. PMID:25153347

  7. Real-time PCR analysis of enteric pathogens from fecal samples of irritable bowel syndrome subjects

    PubMed Central

    2011-01-01

    Background Growing amount of scientific evidence suggests that microbes are involved in the pathophysiology of irritable bowel syndrome (IBS). The predominant fecal microbiota composition of IBS subjects has been widely studied with DNA-based techniques but less research has been focused on the intestinal pathogens in this disorder. Here, we optimized a highly sensitive panel of 12 quantitative real-time PCR (qPCR) assays to shed light on the putative presence of intestinal pathogens in IBS sufferers. The panel was used to screen fecal samples from 96 IBS subjects and 23 healthy controls. Results Fifteen IBS samples (17%) tested positive for Staphylococcus aureus with a thermonuclease (nuc) gene-targeting qPCR assay, whereas none of the healthy controls were positive for S. aureus (p <0.05). The S. aureus -positive IBS samples were confirmed by sequencing of the PCR amplicons. Clostridium perfringens was detected from IBS and control groups with a similar frequency (13% and 17%, respectively) with α-toxin (plc) gene -targeting qPCR assay while none of the samples tested positive for the Cl. perfringens enterotoxin-encoding gene (cpe). Conclusions The qPCR panel consisting of 12 assays for an extensive set of pathogenic microorganisms provides an efficient alternative to the conventional detection of gastrointestinal pathogens and could accelerate the initiation of targeted antibiotic therapy reducing the risk of post-infectious IBS (PI-IBS). S. aureus has not been previously reported to be associated with the onset of IBS. Although we discovered significant differences in the prevalence of S. aureus between the study groups, its importance in giving rise to IBS symptoms requires further studies. PMID:21518462

  8. Three-Dimensional Structure of a Protozoal Double-Stranded RNA Virus That Infects the Enteric Pathogen Giardia lamblia

    PubMed Central

    Janssen, Mandy E. W.; Takagi, Yuko; Parent, Kristin N.; Cardone, Giovanni

    2014-01-01

    ABSTRACT Giardia lamblia virus (GLV) is a small, nonenveloped, nonsegmented double-stranded RNA (dsRNA) virus infecting Giardia lamblia, the most common protozoan pathogen of the human intestine and a major agent of waterborne diarrheal disease worldwide. GLV (genus Giardiavirus) is a member of family Totiviridae, along with several other groups of protozoal or fungal viruses, including Leishmania RNA viruses and Trichomonas vaginalis viruses. Interestingly, GLV is more closely related than other Totiviridae members to a group of recently discovered metazoan viruses that includes penaeid shrimp infectious myonecrosis virus (IMNV). Moreover, GLV is the only known protozoal dsRNA virus that can transmit efficiently by extracellular means, also like IMNV. In this study, we used transmission electron cryomicroscopy and icosahedral image reconstruction to examine the GLV virion at an estimated resolution of 6.0 Å. Its outermost diameter is 485 Å, making it the largest totivirus capsid analyzed to date. Structural comparisons of GLV and other totiviruses highlighted a related “T=2” capsid organization and a conserved helix-rich fold in the capsid subunits. In agreement with its unique capacity as a protozoal dsRNA virus to survive and transmit through extracellular environments, GLV was found to be more thermoresistant than Trichomonas vaginalis virus 1, but no specific protein machinery to mediate cell entry, such as the fiber complexes in IMNV, could be localized. These and other structural and biochemical findings provide a basis for future work to dissect the cell entry mechanism of GLV into a “primitive” (early-branching) eukaryotic host and an important enteric pathogen of humans. IMPORTANCE Numerous pathogenic bacteria, including Corynebacterium diphtheriae, Salmonella enterica, and Vibrio cholerae, are infected with lysogenic bacteriophages that contribute significantly to bacterial virulence. In line with this phenomenon, several pathogenic protozoa

  9. Pathogenic and pathological characteristic of new type gosling viral enteritis first observed in China

    PubMed Central

    Cheng, An-Chun; Wang, Ming-Shu; Chen, Xiao-Yue; Guo, Yu-Fei; Liu, Zhao-Yu; Fang, Peng-Fei

    2001-01-01

    AIM: To study the purifying method and characteristics of new gosling viral enteritis virus (NGVEV), the etiological agent of new gosling viral enteritis (NGVE) which was first recognized in China, as well as the pathomorphological development in goslings infected artificially with NGVEV. METHODS: ① NGVEV virions were purified by the procedure of treatment with chloroform and ammonium sulfate precipitation, dialysis to remove the sulfate radical and ammonium ion and separation by gel filtration chromatography, and SDS-PAGE. ② Forty 2-day-old White Sichuan goslings were orally administered with NGVEV and 24 h later 2 birds were randomly selected and killed at 24 h intervals until death occurred. Specimens (duodenum, ileum, liver, heart, kidney, spleen, lung, proventriculus, pancreas, esophagus, and the intestinal embolus) were taken until all birds in this group died and were sectioned and stained with hemotoxylin and eosin and studied by light microscope. RESULTS: NGVEV shared the typical characteristics of Adenovirus and which structural proteins consisted of 15 polypeptides. Necrosis and sloughing of the epithelial cells covering the villus tips of the duodenum were first observed in goslings 2 d postinfection artificially with NGVEV. With the progress of infection, this lesion rapidly occurred in the epithelium at the base of the villus and with infiltration of the inflammatory cells, the jejunum tended to be involved. With the intensification of mucosa necrosis and inflammatory exudation of the small intestine, fibrinonecrotic enteritis was further developed and embolus composed of either intestinal contents wrapped by pseudomembrane or of the mixture of fibrous exudate and necrotic intestinal mucosa were observed in the middle-lower part of the small intestine. This structure occluded the intestinal tract and made the intestine dilated in appearance. The intestinal glandular cells underwent degeneration, necrosis and might be found sloughed into the lumen

  10. Phylogenetic Diversity of the Enteric Pathogen Salmonella enterica subsp. enterica Inferred from Genome-Wide Reference-Free SNP Characters

    PubMed Central

    Timme, Ruth E.; Pettengill, James B.; Allard, Marc W.; Strain, Errol; Barrangou, Rodolphe; Wehnes, Chris; Van Kessel, JoAnn S.; Karns, Jeffrey S.; Musser, Steven M.; Brown, Eric W.

    2013-01-01

    The enteric pathogen Salmonella enterica is one of the leading causes of foodborne illness in the world. The species is extremely diverse, containing more than 2,500 named serovars that are designated for their unique antigen characters and pathogenicity profiles—some are known to be virulent pathogens, while others are not. Questions regarding the evolution of pathogenicity, significance of antigen characters, diversity of clustered regularly interspaced short palindromic repeat (CRISPR) loci, among others, will remain elusive until a strong evolutionary framework is established. We present the first large-scale S. enterica subsp. enterica phylogeny inferred from a new reference-free k-mer approach of gathering single nucleotide polymorphisms (SNPs) from whole genomes. The phylogeny of 156 isolates representing 78 serovars (102 were newly sequenced) reveals two major lineages, each with many strongly supported sublineages. One of these lineages is the S. Typhi group; well nested within the phylogeny. Lineage-through-time analyses suggest there have been two instances of accelerated rates of diversification within the subspecies. We also found that antigen characters and CRISPR loci reveal different evolutionary patterns than that of the phylogeny, suggesting that a horizontal gene transfer or possibly a shared environmental acquisition might have influenced the present character distribution. Our study also shows the ability to extract reference-free SNPs from a large set of genomes and then to use these SNPs for phylogenetic reconstruction. This automated, annotation-free approach is an important step forward for bacterial disease tracking and in efficiently elucidating the evolutionary history of highly clonal organisms. PMID:24158624

  11. Subboiling Moist Heat Favors the Selection of Enteric Pathogen Clostridium difficile PCR Ribotype 078 Spores in Food

    PubMed Central

    Rodriguez-Palacios, Alexander; Ilic, Sanja; LeJeune, Jeffrey T.

    2016-01-01

    Emerging enteric pathogens could have not only more antibiotic resistance or virulence traits; they could also have increased resistance to heat. We quantified the effects of minimum recommended cooking and higher temperatures, individually on a collection of C. difficile isolates and on the survival probability of a mixture of emerging C. difficile strains. While minimum recommended cooking time/temperature combinations (63–71°C) allowed concurrently tested strains to survive, higher subboiling temperatures reproducibly favored the selection of newly emerging C. difficile PCR ribotype 078. Survival ratios for “ribotypes 078” :  “other ribotypes” (n = 49 : 45 isolates) from the mid-2000s increased from 1 : 1 and 0.7 : 1 at 85°C (for 5 and 10 minutes, resp.) to 2.3 : 1 and 3 : 1 with heating at 96°C (for 5 and 10 minutes, resp.) indicating an interaction effect between the heating temperature and survival of C. difficile genotypes. In multistrain heating experiments, with PCR ribotypes 027 and 078 from 2004 and reference type strain ATCC 9689 banked in the 1970s, multinomial logistic regression (P < 0.01) revealed PCR ribotype 078 was the most resistant to increasing lethal heat treatments. Thermal processes (during cooking or disinfection) may contribute to the selection of emergent specific virulent strains of C. difficile. Despite growing understanding of the role of cooking on human evolution, little is known about the role of cooking temperatures on the selection and evolution of enteric pathogens, especially spore-forming bacteria. PMID:27375748

  12. Subboiling Moist Heat Favors the Selection of Enteric Pathogen Clostridium difficile PCR Ribotype 078 Spores in Food.

    PubMed

    Rodriguez-Palacios, Alexander; Ilic, Sanja; LeJeune, Jeffrey T

    2016-01-01

    Emerging enteric pathogens could have not only more antibiotic resistance or virulence traits; they could also have increased resistance to heat. We quantified the effects of minimum recommended cooking and higher temperatures, individually on a collection of C. difficile isolates and on the survival probability of a mixture of emerging C. difficile strains. While minimum recommended cooking time/temperature combinations (63-71°C) allowed concurrently tested strains to survive, higher subboiling temperatures reproducibly favored the selection of newly emerging C. difficile PCR ribotype 078. Survival ratios for "ribotypes 078" :  "other ribotypes" (n = 49 : 45 isolates) from the mid-2000s increased from 1 : 1 and 0.7 : 1 at 85°C (for 5 and 10 minutes, resp.) to 2.3 : 1 and 3 : 1 with heating at 96°C (for 5 and 10 minutes, resp.) indicating an interaction effect between the heating temperature and survival of C. difficile genotypes. In multistrain heating experiments, with PCR ribotypes 027 and 078 from 2004 and reference type strain ATCC 9689 banked in the 1970s, multinomial logistic regression (P < 0.01) revealed PCR ribotype 078 was the most resistant to increasing lethal heat treatments. Thermal processes (during cooking or disinfection) may contribute to the selection of emergent specific virulent strains of C. difficile. Despite growing understanding of the role of cooking on human evolution, little is known about the role of cooking temperatures on the selection and evolution of enteric pathogens, especially spore-forming bacteria. PMID:27375748

  13. Role of enteric pathogens in the aetiology of neonatal diarrhoea in lambs and goat kids in Spain.

    PubMed Central

    Muñoz, M.; Alvarez, M.; Lanza, I.; Cármenes, P.

    1996-01-01

    Faeces samples from diarrhoeic and non-diarrhoeic lambs and goat kids aged 1-45 days were examined for enteric pathogens. Cryptosporidium parvum was detected in both diarrhoeic lambs (45%) and goat kids (42%) but not in non-diarrhoeic animals. F5+ (K99+) and/or F41+ Escherichia coli strains were isolated from 26% and 22% of the diarrhoeic lambs and goat kids, respectively, although these strains, which did not produce enterotoxins ST I or LT I, were found with similar frequencies in non-diarrhoeic animals. A F5-F41-ST I+ E. coli strain was isolated from a diarrhoeic lamb (0.6%). Verotoxigenic E. coli was isolated from both diarrhoeic and non-diarrhoeic lambs (4.1% and 8.2%, respectively) and there was no association between infection and diarrhoea. The prevalence of group A rotavirus infection in diarrhoeic lambs was very low (2.1%). Groups A and B rotaviruses were detected in three (8.1%) and five (13.5%) diarrhoeic goat kids from two single outbreaks. Group C rotaviruses were detected in four non-diarrhoeic goat kids. An association of diarrhoea and infection was demonstrated only for group B rotavirus. Clostridium perfringens was isolated from 10.8% of the diarrhoeic goat kids but not from non-diarrhoeic goat kids or lambs. Salmonella arizonae was isolated from a diarrhoeic goat kid (2.7%) and the clinical characteristics of the outbreaks where these two latter enteropathogens were found different from the rest. Picobirnaviruses were detected in a diarrhoeic lamb. No coronaviruses were detected using a bovine coronavirus ELISA. No evidence was found of synergistic effect between the agents studied. Enteric pathogens were not found in four (8.7%) and three (20%) outbreaks of diarrhoea in lambs and goat kids, respectively. PMID:8760970

  14. Multicopy single-stranded DNA directs intestinal colonization of enteric pathogens

    SciTech Connect

    Elfenbein, Johanna R.; Knodler, Leigh A.; Nakayasu, Ernesto S.; Ansong, Charles; Brewer, Heather M.; Bogomolnaya, Lydia; Adams, L. Garry; McClelland, Michael; Adkins, Joshua N.; Andrews-Polymenis, Helene L.; Fang, Ferric C.

    2015-09-14

    Multicopy single-stranded DNAs (msDNAs) are hybrid RNA-DNA molecules encoded on retroelements called retrons and produced by the action of retron reverse transcriptases. Retrons are widespread in bacteria but the natural function of msDNA has remained elusive despite 30 years of study. The major roadblock to elucidation of the function of these unique molecules has been the lack of any identifiable phenotypes for mutants unable to make msDNA. We report that msDNA of the zoonotic pathogen Salmonella Typhimurium is necessary for colonization of the intestine. Similarly, we observed a defect in intestinal persistence in an enteropathogenic E. coli mutant lacking its retron reverse transcriptase. Under anaerobic conditions in the absence of msDNA, proteins of central anaerobic metabolism needed for Salmonella colonization of the intestine are dysregulated. We show that the msDNA-deficient mutant can utilize nitrate, but not other alternate electron acceptors in anaerobic conditions. Consistent with the availability of nitrate in the inflamed gut, a neutrophilic inflammatory response partially rescued the ability of a mutant lacking msDNA to colonize the intestine. These findings together indicate that the mechanistic basis of msDNA function during Salmonella colonization of the intestine is proper production of proteins needed for anaerobic metabolism. We further conclude that a natural function of msDNA is to regulate protein abundance, the first attributable function for any msDNA. Our data provide novel insight into the function of this mysterious molecule that likely represents a new class of regulatory molecules.

  15. Multicopy single-stranded DNA directs intestinal colonization of enteric pathogens

    DOE PAGESBeta

    Elfenbein, Johanna R.; Knodler, Leigh A.; Nakayasu, Ernesto S.; Ansong, Charles; Brewer, Heather M.; Bogomolnaya, Lydia; Adams, L. Garry; McClelland, Michael; Adkins, Joshua N.; Andrews-Polymenis, Helene L.; et al

    2015-09-14

    Multicopy single-stranded DNAs (msDNAs) are hybrid RNA-DNA molecules encoded on retroelements called retrons and produced by the action of retron reverse transcriptases. Retrons are widespread in bacteria but the natural function of msDNA has remained elusive despite 30 years of study. The major roadblock to elucidation of the function of these unique molecules has been the lack of any identifiable phenotypes for mutants unable to make msDNA. We report that msDNA of the zoonotic pathogen Salmonella Typhimurium is necessary for colonization of the intestine. Similarly, we observed a defect in intestinal persistence in an enteropathogenic E. coli mutant lacking itsmore » retron reverse transcriptase. Under anaerobic conditions in the absence of msDNA, proteins of central anaerobic metabolism needed for Salmonella colonization of the intestine are dysregulated. We show that the msDNA-deficient mutant can utilize nitrate, but not other alternate electron acceptors in anaerobic conditions. Consistent with the availability of nitrate in the inflamed gut, a neutrophilic inflammatory response partially rescued the ability of a mutant lacking msDNA to colonize the intestine. These findings together indicate that the mechanistic basis of msDNA function during Salmonella colonization of the intestine is proper production of proteins needed for anaerobic metabolism. We further conclude that a natural function of msDNA is to regulate protein abundance, the first attributable function for any msDNA. Our data provide novel insight into the function of this mysterious molecule that likely represents a new class of regulatory molecules.« less

  16. Multicopy Single-Stranded DNA Directs Intestinal Colonization of Enteric Pathogens

    PubMed Central

    Elfenbein, Johanna R.; Knodler, Leigh A.; Nakayasu, Ernesto S.; Ansong, Charles; Brewer, Heather M.; Bogomolnaya, Lydia; Adams, L. Garry; McClelland, Michael; Adkins, Joshua N.; Andrews-Polymenis, Helene L.

    2015-01-01

    Multicopy single-stranded DNAs (msDNAs) are hybrid RNA-DNA molecules encoded on retroelements called retrons and produced by the action of retron reverse transcriptases. Retrons are widespread in bacteria but the natural function of msDNA has remained elusive despite 30 years of study. The major roadblock to elucidation of the function of these unique molecules has been the lack of any identifiable phenotypes for mutants unable to make msDNA. We report that msDNA of the zoonotic pathogen Salmonella Typhimurium is necessary for colonization of the intestine. Similarly, we observed a defect in intestinal persistence in an enteropathogenic E. coli mutant lacking its retron reverse transcriptase. Under anaerobic conditions in the absence of msDNA, proteins of central anaerobic metabolism needed for Salmonella colonization of the intestine are dysregulated. We show that the msDNA-deficient mutant can utilize nitrate, but not other alternate electron acceptors in anaerobic conditions. Consistent with the availability of nitrate in the inflamed gut, a neutrophilic inflammatory response partially rescued the ability of a mutant lacking msDNA to colonize the intestine. These findings together indicate that the mechanistic basis of msDNA function during Salmonella colonization of the intestine is proper production of proteins needed for anaerobic metabolism. We further conclude that a natural function of msDNA is to regulate protein abundance, the first attributable function for any msDNA. Our data provide novel insight into the function of this mysterious molecule that likely represents a new class of regulatory molecules. PMID:26367458

  17. Multicopy single-stranded DNA directs intestinal colonization of enteric pathogens

    SciTech Connect

    Elfenbein, Johanna R.; Knodler, Leigh A.; Nakayasu, Ernesto S.; Ansong, Charles; Brewer, Heather M.; Bogomolnaya, Lydia; Adams, L. G.; McClelland, Michael; Adkins, Joshua N.; Andrews-Polymenis, Helene L.

    2015-09-14

    Multicopy single-stranded DNAs (msDNAs) are hybrid RNA-DNA molecules encoded on retroelements called retrons and produced by the action of retron reverse transcriptases. Retrons are widespread in bacteria but the natural function of msDNA has remained elusive despite 30 years of study. The major roadblock to elucidation of the function of these unique molecules has been the lack of any identifiable phenotypes for mutants unable to make msDNA. We report that msDNA of the zoonotic pathogen Salmonella Typhimurium is necessary for colonization of the intestine. Similarly, we observed a defect in intestinal persistence in an enteropathogenic E. coli mutant lacking its retron reverse transcriptase. Under anaerobic conditions in the absence of msDNA, proteins of central anaerobic metabolism needed for Salmonella colonization of the intestine are dysregulated. We show that the msDNA-deficient mutant can utilize nitrate but not other alternate electron acceptors in anaerobic conditions. Consistent with the availability of nitrate in the inflamed gut, a neutrophilic inflammatory response partially rescued the ability of a mutant lacking msDNA to colonize the intestine. These findings together indicate that the mechanistic basis of msDNA function during Salmonella colonization of the intestine is proper production of proteins needed for anaerobic metabolism. We further conclude that a natural function of msDNA is to regulate protein abundance, the first attributable function for any msDNA. Our data provide novel insight into the function of this mysterious molecule that likely represents a new class of regulatory molecules.

  18. Low dietary iron intake restrains the intestinal inflammatory response and pathology of enteric infection by food-borne bacterial pathogens.

    PubMed

    Kortman, Guus A M; Mulder, Michelle L M; Richters, Thijs J W; Shanmugam, Nanda K N; Trebicka, Estela; Boekhorst, Jos; Timmerman, Harro M; Roelofs, Rian; Wiegerinck, Erwin T; Laarakkers, Coby M; Swinkels, Dorine W; Bolhuis, Albert; Cherayil, Bobby J; Tjalsma, Harold

    2015-09-01

    Orally administrated iron is suspected to increase susceptibility to enteric infections among children in infection endemic regions. Here we investigated the effect of dietary iron on the pathology and local immune responses in intestinal infection models. Mice were held on iron-deficient, normal iron, or high iron diets and after 2 weeks they were orally challenged with the pathogen Citrobacter rodentium. Microbiome analysis by pyrosequencing revealed profound iron- and infection-induced shifts in microbiota composition. Fecal levels of the innate defensive molecules and markers of inflammation lipocalin-2 and calprotectin were not influenced by dietary iron intervention alone, but were markedly lower in mice on the iron-deficient diet after infection. Next, mice on the iron-deficient diet tended to gain more weight and to have a lower grade of colon pathology. Furthermore, survival of the nematode Caenorhabditis elegans infected with Salmonella enterica serovar Typhimurium was prolonged after iron deprivation. Together, these data show that iron limitation restricts disease pathology upon bacterial infection. However, our data also showed decreased intestinal inflammatory responses of mice fed on high iron diets. Thus additionally, our study indicates that the effects of iron on processes at the intestinal host-pathogen interface may highly depend on host iron status, immune status, and gut microbiota composition. PMID:26046550

  19. Survival of two bacterial fish pathogens (Aeromonas salmonicida and the Enteric Redmouth Bacterium) in ozonated, chlorinated, and untreated waters

    USGS Publications Warehouse

    Wedemeyer, Gary A.; Nelson, Nancy C.

    1977-01-01

    Ozone and chlorine inactivation curves were determined in three water types at 20 °C for the destruction of the fish pathogens Aeromonas salmonicida, the etiologic agent of furunculosis, and the enteric redmouth bacterium (ERM). In phosphate-buffered distilled water, 0.01 mg/ℓ ozone inactivated 103 cells/ml of ERM and A. salmonicida in 1/2 and 10 min, respectively. Chlorine at this concentration had little effect on either pathogen and a residual of at least 0.05 mg/ℓ was needed to achieve a complete kill within a 10-min contact time. In soft lake water (30 mg/ℓ as CaCO3) a chlorine residual of 0.1 mg/ℓ rapidly  inactivated A. salmonicida and ERM but in hard water (120 mg/ℓ) A. salmonicida was more resistant and 0.2 mg/ℓ chlorine was required. Ozonation of the two lake waters at 90 mg O3∙h−1∙ℓ−1 (equivalent to a 0.01 mg/ℓ residual in ozone demand-free water) was required to destroy both pathogens within 10 min.In untreated soft lake water 103 cells/ml of A. salmonicida survived only 2 days, while the ERM bacterium (103 cells/ml) survived even after 20 day s in soft and hard untreated lake waters.

  20. First molecular characterization of enteric protozoa and the human pathogenic microsporidian, Enterocytozoon bieneusi, in captive snakes in China.

    PubMed

    Karim, Md Robiul; Yu, Fuchang; Li, Jian; Li, Junqiang; Zhang, Longxian; Wang, Rongjun; Rume, Farzana Islam; Jian, Fuchun; Zhang, Sumei; Ning, Changshen

    2014-08-01

    Enteric protozoa are frequently found in snakes. Nevertheless, few studies regarding genetic characterization of these parasites have been carried out. We describe here the first molecular survey of protozoan pathogens from snakes in China and the first report on Enterocytozoon bieneusi genotyping in snakes in the world. Here, 240 fecal specimens were collected from two species of captive snakes, Naja naja (Indian cobra) and Ptyas mucosus (Oriental rat snake), in Guangxi Province, China, and examined by PCR amplification of the small subunit-ribosomal RNA of enteric protozoa and the internal transcribed spacer of ribosomal RNA of E. bieneusi. Cryptosporidium serpentis was identified in three specimens (2.1%) of Oriental rat snakes. Caryospora was found in 5.4% specimens, including eight from cobras (8.1%) and five from rat snakes (3.6%), and represented six new species-Caryospora sp. SKC-2014a to Caryospora sp. SKC-2014 f. Three new Eimeria species, Eimeria sp. SKE-2014a to Eimeria sp. SKE-2014c, were detected in three specimens (2.1%) from rat snakes. Additionally, Sarcocystis sp. SKS-2014 was detected in one specimen from a cobra. The infection rates of E. bieneusi were 3.0% in cobras and 5.7% in rat snakes. Sequence analysis of 11 PCR products revealed the presence of six E. bieneusi genotypes-two known genotypes (type IV and Henan V) and four new genotypes (CRep-1 to CRep-4). All six E. bieneusi genotypes belonged to the zoonotic group (group 1). This result raised the possibility that E. bieneusi could be present in animals consumed by snakes. This should be taken into consideration to better understand the diversity of the parasite, its transmission through the predator-prey relationship, and public health implications. PMID:24906991

  1. Antagonistic activities of some Bifidobacterium sp. strains isolated from resident infant gastrointestinal microbiota on Gram-negative enteric pathogens.

    PubMed

    Delcaru, Cristina; Alexandru, Ionela; Podgoreanu, Paulina; Cristea, Violeta Corina; Bleotu, Coralia; Chifiriuc, Mariana Carmen; Bezirtzoglou, Eugenia; Lazar, Veronica

    2016-06-01

    The gastrointestinal microbiota contributes to the consolidation of the anti-infectious barrier against enteric pathogens. The purpose of this study was to investigate the influence of Bifidobacterium sp. strains, recently isolated from infant gastrointestinal microbiota on the in vitro growth and virulence features expression of enteropathogenic bacterial strains. The antibacterial activity of twelve Bifidobacterium sp. strains isolated from human feces was examined in vitro against a wide range of Gram negative pathogenic strains isolated from 30 infant patients (3 days to 5 years old) with diarrhea. Both potential probiotic strains (Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bifidobacterium catenulatum, Bifidobacterium breve, Bifidobacterium ruminantium) and enteropathogenic strains (EPEC, EIEC, Klebsiella pneumoniae, Salmonella sp., Yersinia enterocolitica, Pseudomonas aeruginosa) were identified by MALDI-TOF and confirmed serologically when needed. The bactericidal activity, growth curve, adherence to the cellular HEp-2 substratum and production of soluble virulence factors have been assessed in the presence of different Bifidobacterium sp. cultures and fractions (whole culture and free-cell supernatants). Among the twelve Bifidobacterium sp. strains, the largest spectrum of antimicrobial activity against 9 of the 18 enteropathogenic strains was revealed for a B. breve strain recently isolated from infant intestinal feces. The whole culture and free-cell supernatant of B. breve culture decreased the multiplication rate, shortened the log phase and the total duration of the growth curve, with an earlier entrance in the decline phase and inhibited the adherence capacity to a cellular substratum and the swimming/swarming motility too. These results indicate the significant probiotic potential of the B. breve strain. PMID:26921694

  2. Transcriptional Analysis of Host-Pathogen Interaction in Genetically Disparate Chicken Lines Showing Different Levels of Disease Susceptibility to Necrotic Enteritis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Necrotic enteritis (NE) has reemerged as a significant problem as a result of the growing concern over antibiotic resistance in human pathogens and restrictions on the use of antibiotics. It is difficult to reproduce NE by C. perfringens alone, therefore, a well established co-infection model using ...

  3. Presence of pathogenic enteric viruses in illegally imported meat and meat products to EU by international air travelers.

    PubMed

    Rodríguez-Lázaro, David; Diez-Valcarce, Marta; Montes-Briones, Rebeca; Gallego, David; Hernández, Marta; Rovira, Jordi

    2015-09-16

    One hundred twenty two meat samples confiscated from passengers on flights from non-European countries at the International Airport of Bilbao (Spain) were tested for the presence of the main foodborne viral pathogens (human noroviruses genogroups I and II, hepatitis A and E viruses) during 2012 and 2013. A sample process control virus, murine norovirus, was used to evaluate the correct performance of the method. Overall, 67 samples were positive for at least one enteric viruses, 65 being positive for hepatitis E virus (53.3%), 3 for human norovirus genogroup I (2.5%) and 1 for human norovirus genogroup II (0.8%), whereas hepatitis A virus was not detected in any sample. The type of positive meat samples was diverse, but mainly was pork meat products (64.2%). The geographical origin of the positive samples was wide and diverse; samples from 15 out 19 countries tested were positive for at least one virus. However, the estimated virus load was low, ranging from 55 to 9.0 × 10(4) PDU per gram of product. The results obtained showed the potential introduction of viral agents in travelers' luggage, which constitute a neglected route of introduction and transmission. PMID:25951793

  4. Ranking the disease burden of 14 pathogens in food sources in the United States using attribution data from outbreak investigations and expert elicitation.

    PubMed

    Batz, Michael B; Hoffmann, Sandra; Morris, J Glenn

    2012-07-01

    Understanding the relative public health impact of major microbiological hazards across the food supply is critical for a risk-based national food safety system. This study was conducted to estimate the U.S. health burden of 14 major pathogens in 12 broad categories of food and to then rank the resulting 168 pathogen-food combinations. These pathogens examined were Campylobacter, Clostridium perfringens, Escherichia coli O157:H7, Listeria monocytogenes, norovirus, Salmonella enterica, Toxoplasma gondii, and all other FoodNet pathogens. The health burden associated with each pathogen was measured using new estimates of the cost of illness and loss of quality-adjusted life years (QALYs) from acute and chronic illness and mortality. A new method for attributing illness to foods was developed that relies on both outbreak data and expert elicitation. This method assumes that empirical data are generally preferable to expert judgment; thus, outbreak data were used for attribution except where evidence suggests that these data are considered not representative of food attribution. Based on evaluation of outbreak data, expert elicitation, and published scientific literature, outbreak-based attribution estimates for Campylobacter, Toxoplasma, Cryptosporidium, and Yersinia were determined not representative; therefore, expert-based attribution were included for these four pathogens. Sensitivity analyses were conducted to assess the effect of attribution data assumptions on rankings. Disease burden was concentrated among a relatively small number of pathogen-food combinations. The top 10 pairs were responsible for losses of over $8 billion and 36,000 QALYs, or more than 50 % of the total across all pairs. Across all 14 pathogens, poultry, pork, produce, and complex foods were responsible for nearly 60 % of the total cost of illness and loss of QALYs. PMID:22980012

  5. A hydrodynamics-based approach to evaluating the risk of waterborne pathogens entering drinking water intakes in a large, stratified lake.

    PubMed

    Hoyer, Andrea B; Schladow, S Geoffrey; Rueda, Francisco J

    2015-10-15

    Pathogen contamination of drinking water lakes and reservoirs is a severe threat to human health worldwide. A major source of pathogens in surface sources of drinking waters is from body-contact recreation in the water body. However, dispersion pathways of human waterborne pathogens from recreational beaches, where body-contact recreation is known to occur to drinking water intakes, and the associated risk of pathogens entering the drinking water supply remain largely undocumented. A high spatial resolution, three-dimensional hydrodynamic and particle tracking modeling approach has been developed to analyze the risk and mechanisms presented by pathogen dispersion. The pathogen model represents the processes of particle release, transport and survival. Here survival is a function of both water temperature and cumulative exposure to ultraviolet (UV) radiation. Pathogen transport is simulated using a novel and computationally efficient technique of tracking particle trajectories backwards, from a drinking water intake toward their source areas. The model has been applied to a large, alpine lake - Lake Tahoe, CA-NV (USA). The dispersion model results reveal that for this particular lake (1) the risk of human waterborne pathogens to enter drinking water intakes is low, but significant; (2) this risk is strongly related to the depth of the thermocline in relation to the depth of the intake; (3) the risk increases with the seasonal deepening of the surface mixed layer; and (4) the risk increases at night when the surface mixed layer deepens through convective mixing and inactivation by UV radiation is eliminated. While these risk factors will quantitatively vary in different lakes, these same mechanisms will govern the process of transport of pathogens. PMID:26162312

  6. The reliability of the examination of foods, processed for safety, for enteric pathogens and Enterobacteriaceae: a mathematical and ecological study

    PubMed Central

    Drion, E. F.; Mossel, D. A. A.

    1977-01-01

    Because of the paucity of quantitative data on numbers of other enteric pathogens in food, the reliability of the examination of processed foods for Enterobacteriaceae was estimated taking Salmonella as a model. For this purpose an assessment was carried out of the risk of accepting Salmonella contaminated consignments of foods, despite a negative outcome of (i) examination of 1·5 kg samples for Salmonella; (ii) examination of one or two 1 g samples for Enterobacteriaceae; (iii) simultaneous application of both tests. The computations were based on the results of the examination of 6830 samples of dried foods, processed for safety, out of a total of 18170 samples. Only 69 samples permitted the exact calculation of the ε-factor, defined as c.f.u./g of Enterobacteriaceae/c.f.u./g of Salmonella; 4642 were positive for the former group but `free' from Salmonella, and the rest were negative in both tests. Numbers of c.f.u./g for both groups, and hence the ε-factors, varied widely between commodities and also between different consignments of the same food product. The average for ε amounted to 5·8 × 103, far from the base-line value of 0·75 × 103 assessed earlier. In only 0·1% of samples did the Enterobacteriaceae test fail to achieve the required consumer protection. This investigation therefore substantiates that testing foods processed for safety by examining accurately chosen quantities for ecologically well selected and taxonomically thoroughly defined index organisms is a most effective procedure in terms both of consumer protection and simplicity of examination without compelling the food industry to achieve hardly attainable microbiological quality standards. PMID:325125

  7. SIGIRR, a Negative Regulator of TLR/IL-1R Signalling Promotes Microbiota Dependent Resistance to Colonization by Enteric Bacterial Pathogens

    PubMed Central

    Sham, Ho Pan; Yu, Emily Yi Shan; Gulen, Muhammet F.; Bhinder, Ganive; Stahl, Martin; Chan, Justin M.; Brewster, Lara; Morampudi, Vijay; Gibson, Deanna L.; Hughes, Michael R.; McNagny, Kelly M.; Li, Xiaoxia; Vallance, Bruce A.

    2013-01-01

    Enteric bacterial pathogens such as enterohemorrhagic E. coli (EHEC) and Salmonella Typhimurium target the intestinal epithelial cells (IEC) lining the mammalian gastrointestinal tract. Despite expressing innate Toll-like receptors (TLRs), IEC are innately hypo-responsive to most bacterial products. This is thought to prevent maladaptive inflammatory responses against commensal bacteria, but it also limits antimicrobial responses by IEC to invading bacterial pathogens, potentially increasing host susceptibility to infection. One reason for the innate hypo-responsiveness of IEC is their expression of Single Ig IL-1 Related Receptor (SIGIRR), a negative regulator of interleukin (IL)-1 and TLR signaling. To address whether SIGIRR expression and the innate hypo-responsiveness of IEC impacts on enteric host defense, Sigirr deficient (−/−) mice were infected with the EHEC related pathogen Citrobacter rodentium. Sigirr −/− mice responded with accelerated IEC proliferation and strong pro-inflammatory and antimicrobial responses but surprisingly, Sigirr −/− mice proved dramatically more susceptible to infection than wildtype mice. Through haematopoietic transplantation studies, it was determined that SIGIRR expression by non-haematopoietic cells (putative IEC) regulated these responses. Moreover, the exaggerated responses were found to be primarily dependent on IL-1R signaling. Whilst exploring the basis for their susceptibility, Sigirr −/− mice were found to be unusually susceptible to intestinal Salmonella Typhimurium colonization, developing enterocolitis without the typical requirement for antibiotic based removal of competing commensal microbes. Strikingly, the exaggerated antimicrobial responses seen in Sigirr −/− mice were found to cause a rapid and dramatic loss of commensal microbes from the infected intestine. This depletion appears to reduce the ability of the microbiota to compete for space and nutrients (colonization resistance) with the

  8. SIGIRR, a negative regulator of TLR/IL-1R signalling promotes Microbiota dependent resistance to colonization by enteric bacterial pathogens.

    PubMed

    Sham, Ho Pan; Yu, Emily Yi Shan; Gulen, Muhammet F; Bhinder, Ganive; Stahl, Martin; Chan, Justin M; Brewster, Lara; Morampudi, Vijay; Gibson, Deanna L; Hughes, Michael R; McNagny, Kelly M; Li, Xiaoxia; Vallance, Bruce A

    2013-01-01

    Enteric bacterial pathogens such as enterohemorrhagic E. coli (EHEC) and Salmonella Typhimurium target the intestinal epithelial cells (IEC) lining the mammalian gastrointestinal tract. Despite expressing innate Toll-like receptors (TLRs), IEC are innately hypo-responsive to most bacterial products. This is thought to prevent maladaptive inflammatory responses against commensal bacteria, but it also limits antimicrobial responses by IEC to invading bacterial pathogens, potentially increasing host susceptibility to infection. One reason for the innate hypo-responsiveness of IEC is their expression of Single Ig IL-1 Related Receptor (SIGIRR), a negative regulator of interleukin (IL)-1 and TLR signaling. To address whether SIGIRR expression and the innate hypo-responsiveness of IEC impacts on enteric host defense, Sigirr deficient (-/-) mice were infected with the EHEC related pathogen Citrobacter rodentium. Sigirr -/- mice responded with accelerated IEC proliferation and strong pro-inflammatory and antimicrobial responses but surprisingly, Sigirr -/- mice proved dramatically more susceptible to infection than wildtype mice. Through haematopoietic transplantation studies, it was determined that SIGIRR expression by non-haematopoietic cells (putative IEC) regulated these responses. Moreover, the exaggerated responses were found to be primarily dependent on IL-1R signaling. Whilst exploring the basis for their susceptibility, Sigirr -/- mice were found to be unusually susceptible to intestinal Salmonella Typhimurium colonization, developing enterocolitis without the typical requirement for antibiotic based removal of competing commensal microbes. Strikingly, the exaggerated antimicrobial responses seen in Sigirr -/- mice were found to cause a rapid and dramatic loss of commensal microbes from the infected intestine. This depletion appears to reduce the ability of the microbiota to compete for space and nutrients (colonization resistance) with the invading pathogens

  9. Expert elicitation as a means to attribute 28 enteric pathogens to foodborne, waterborne, animal contact, and person-to-person transmission routes in Canada.

    PubMed

    Butler, Ainslie J; Thomas, M Kate; Pintar, Katarina D M

    2015-04-01

    Enteric illness contributes to a significant burden of illness in Canada and globally. Understanding its sources is a critical step in identifying and preventing health risks. Expert elicitation is a powerful tool, used previously, to obtain information about enteric illness source attribution where information is difficult or expensive to obtain. Thirty-one experts estimated transmission of 28 pathogens via major transmission routes (foodborne, waterborne, animal contact, person-to-person, and other) at the point of consumption. The elicitation consisted of a (snowball) recruitment phase; administration of a pre-survey to collect background information, an introductory webinar, an elicitation survey, a 1-day discussion, survey readministration, and a feedback exercise, and surveys were administered online. Experts were prompted to quantify changes in contamination at the point of entry into the kitchen versus point of consumption. Estimates were combined via triangular probability distributions, and medians and 90% credible-interval estimates were produced. Transmission was attributed primarily to food for Bacillus cereus, Clostridium perfringens, Cyclospora cayetanensis, Trichinella spp., all three Vibrio spp. categories explored, and Yersinia enterocolitica. Multisource pathogens (e.g., transmitted commonly through both water and food) such as Campylobacter spp., four Escherichia coli categories, Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus were also estimated as mostly foodborne. Water was the primary pathway for Giardia spp. and Cryptosporidium spp., and person-to-person transmission dominated for six enteric viruses and Shigella spp. Consideration of the point of attribution highlighted the importance of food handling and cross-contamination in the transmission pathway. This study provides source attribution estimates of enteric illness for Canada, considering all possible transmission routes. Further research is necessary to improve our

  10. Analysis of occurrence of bacteraemia with pathogens from gastrointestinal tract in patients fed parenterally and enterally in the intensive care unit

    PubMed Central

    Różowicz, Aleksandra; Spychalska, Katarzyna; Nakonowska, Beata; Kupczyk, Kinga; Kusza, Krzysztof

    2016-01-01

    Introduction Bacterial translocation is a migration of microorganisms and their toxins from the intestinal lumen to the mesenteric lymph nodes, blood, and abdominal organs. It can lead to local inflammatory response and a potential increase in intestinal permeability leading to systemic infections and multiple organ failure. Enteral nutrition stimulates gastrointestinal motility, increases blood flow, and improves the integration of the intestinal barrier. Aim The impact of enteral (EN) and parenteral (PN) nutrition on occurrence of bacteraemia caused by pathogens from the gastrointestinal tract. Material and methods It was a retrospective analysis of medical documentation of 254 patients. Microbiological tests were analysed, assessing the presence of bacteraemia or sepsis pathogens from the gastrointestinal tract. In 52 patients gastrointestinal pathogens in blood were found: 29 patients were fed enterally (I group – EN and EN + PN) and 23 only parenterally (II group – PN). Results The mean length of stay in hospital until the occurrence of bacteraemia in group I was 14, and in group II it was 13 days. Mean time without EN was 4 days (first group) and 12 days (second group). Time of stay in ICU and mortality in the group of patients fed parenterally was observed: group I – 25 days, mortality 34%; group II – 37 days, mortality 56%. In the analysed group the EN and the length of the absence of this kind of feeding did not affect the occurrence of bacteraemia by gastrointestinal pathogens. Conclusions However, patients fed only parenterally who had bacteraemia required a longer stay in the ICU and had a higher rate of mortality than the patients with EN. PMID:27350841

  11. Prevalence of human pathogenic enteric viruses in bivalve molluscan shellfish and cultured shrimp in south west coast of India.

    PubMed

    Umesha, Kanasinakatte R; Bhavani, Naniah C; Venugopal, Moleyur N; Karunasagar, Indrani; Krohne, Georg; Karunasagar, Iddya

    2008-03-20

    The prevalence of human enteric viruses in bivalve molluscan shellfish and shrimp collected off the south west coast of India was studied to assess the extent of fecal pollution of coastal environment. Out of 194 samples analyzed, 37% of oyster, 46% of clam and 15% of shrimp samples were positive for enteroviruses (EV). Adenoviruses (ADV) were detected in 17% of oyster and 27% of clam samples. However, other enteric viruses such as noroviruses (NoV) and hepatitis A virus (HAV) were not detected in any of the samples. High prevalence of EV and ADV was noticed between May to December. Thirty four percent of oyster and 49% of clam samples showed fecal coliform values higher than the limit. MS-2 phage was detected in 57% of oyster and 73% of clam samples. The presence of MS-2 phage and human enteric viruses showed association while fecal coliforms and enteric viruses showed no association. However, 17 samples, which were positive for enteric viruses (EV and ADV), were negative for MS-2 phage. PMID:18279989

  12. Pattern of co-infection by enteric pathogenic parasites among HIV sero-positive individuals in a Tertiary Care Hospital, Mumbai, India

    PubMed Central

    Ahmed, Nishat Hussain; Chowdhary, Abhay

    2015-01-01

    Introduction: One of the major medical concerns in people living with HIV/AIDS (PLHA) is management of diarrhea that can lead to severe morbidity and mortality. Such clinical scenario warrants an analysis of intestinal parasites, which are important opportunistic pathogens in PLHA. Owing to the scarcity of recent pattern of intestinal opportunistic infections from this region, the study was designed to determine the opportunistic parasites causing diarrhea in PLHA; and to find out whether there is any significant difference in the enteric parasitic pathogens in patients with different immunological status and in those on highly active anti retro-viral therapy (HAART). Materials and Methods: Analysis of the spectrum of intestinal parasites was carried out with 192 subjects in two groups (142 HIV sero-positive patients having diarrhea and 50 HIV sero-negative patients having diarrhea). The routine light microscopic examination was carried out to determine the infection and CD4+ T-Lymphocyte count was estimated using flow cytometry. Results: Enteric parasites were detected in 35.9% of HIV sero-positive patients having diarrhea and 18% of HIV sero-negative patients having diarrhea. Most common opportunistic enteric parasite was Isospora belli (11.5%); others were Entamoeba histolytica (4.7%), Cryptosporidium sp. (3.6%), Strongyloides stercoralis (3.1%), Giardia intestinalis (3.1%) and Cyclospora cayatanenesis (1.6%). Opportunistic enteric parasites were detected in significantly low numbers in patients with CD4+ T-Lymphocyte counts >500 cells/ml; and in those taking HAART. PMID:26392653

  13. Contamination of Groundwater Systems in the US and Canada by Enteric Pathogens, 1990–2013: A Review and Pooled-Analysis

    PubMed Central

    Hynds, Paul Dylan; Thomas, M. Kate; Pintar, Katarina Dorothy Milena

    2014-01-01

    Background Up to 150 million North Americans currently use a groundwater system as their principal drinking water source. These systems are a potential source of exposure to enteric pathogens, contributing to the burden of waterborne disease. Waterborne disease outbreaks have been associated with US and Canadian groundwater systems over the past two decades. However, to date, this literature has not been reviewed in a comprehensive manner. Methods and Principal Findings A combined review and pooled-analysis approach was used to investigate groundwater contamination in Canada and the US from 1990 to 2013; fifty-five studies met eligibility criteria. Four study types were identified. It was found that study location affects study design, sample rate and studied pathogen category. Approximately 15% (316/2210) of samples from Canadian and US groundwater sources were positive for enteric pathogens, with no difference observed based on system type. Knowledge gaps exist, particularly in exposure assessment for attributing disease to groundwater supplies. Furthermore, there is a lack of consistency in risk factor reporting (local hydrogeology, well type, well use, etc). The widespread use of fecal indicator organisms in reported studies does not inform the assessment of human health risks associated with groundwater supplies. Conclusions This review illustrates how groundwater study design and location are critical for subsequent data interpretation and use. Knowledge gaps exist related to data on bacterial, viral and protozoan pathogen prevalence in Canadian and US groundwater systems, as well as a need for standardized approaches for reporting study design and results. Fecal indicators are examined as a surrogate for health risk assessments; caution is advised in their widespread use. Study findings may be useful during suspected waterborne outbreaks linked with a groundwater supply to identify the likely etiological agent and potential transport pathway. PMID:24806545

  14. Inhibition of enteric pathogens and surrogates using integrated, high intensity 405nm led light on the surface of almonds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The disinfecting properties of 405 nm light were investigated against Escherichia coli O157:H7, Salmonella, and their non-pathogenic surrogate bacteria on the surface of almonds. High intensity monochromatic blue light (MBL) was generated from an array of narrow-band 405 nm light-emitting diodes (LE...

  15. The pathogenicity of an enteric Citrobacter rodentium infection is enhanced by deficiencies in the antioxidants selenium and vitamin E

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrobacter rodentium is a mouse pathogen that shares many characteristics with human enteropathogenic (EPEC) and enterohemorrhagic (EHEC) Escherichia coli, the causative agents for human disease, and serves as a useful model to study immunity to these organisms. In this study, the effect of a doub...

  16. Vaccines for viral and bacterial pathogens causing acute gastroenteritis: Part I: Overview, vaccines for enteric viruses and Vibrio cholerae

    PubMed Central

    O’Ryan, Miguel; Vidal, Roberto; del Canto, Felipe; Salazar, Juan Carlos; Montero, David

    2015-01-01

    Efforts to develop vaccines for prevention of acute diarrhea have been going on for more than 40 y with partial success. The myriad of pathogens, more than 20, that have been identified as a cause of acute diarrhea throughout the years pose a significant challenge for selecting and further developing the most relevant vaccine candidates. Based on pathogen distribution as identified in epidemiological studies performed mostly in low-resource countries, rotavirus, Cryptosporidium, Shigella, diarrheogenic E. coli and V. cholerae are predominant, and thus the main targets for vaccine development and implementation. Vaccination against norovirus is most relevant in middle/high-income countries and possibly in resource-deprived countries, pending a more precise characterization of disease impact. Only a few licensed vaccines are currently available, of which rotavirus vaccines have been the most outstanding in demonstrating a significant impact in a short time period. This is a comprehensive review, divided into 2 articles, of nearly 50 vaccine candidates against the most relevant viral and bacterial pathogens that cause acute gastroenteritis. In order to facilitate reading, sections for each pathogen are organized as follows: i) a discussion of the main epidemiological and pathogenic features; and ii) a discussion of vaccines based on their stage of development, moving from current licensed vaccines to vaccines in advanced stage of development (in phase IIb or III trials) to vaccines in early stages of clinical development (in phase I/II) or preclinical development in animal models. In this first article we discuss rotavirus, norovirus and Vibrio cholerae. In the following article we will discuss Shigella, Salmonella (non-typhoidal), diarrheogenic E. coli (enterotoxigenic and enterohemorragic), and Campylobacter jejuni. PMID:25715048

  17. Investigation of the Enteric Pathogenic Potential of Oral Campylobacter concisus Strains Isolated from Patients with Inflammatory Bowel Disease

    PubMed Central

    Octavia, Sophie; Day, Andrew S.; Riordan, Stephen M.; Grimm, Michael C.; Lan, Ruiting; Lemberg, Daniel; Tran, Thi Anh Tuyet; Zhang, Li

    2012-01-01

    Background Campylobacter concisus, a bacterium colonizing the human oral cavity, has been shown to be associated with inflammatory bowel disease (IBD). This study investigated if patients with IBD are colonized with specific oral C. concisus strains that have potential to cause enteric diseases. Methodology Seventy oral and enteric C. concisus isolates obtained from eight patients with IBD and six controls were examined for housekeeping genes by multilocus sequence typing (MLST), Caco2 cell invasion by gentamicin-protection-assay, protein analysis by mass spectrometry and SDS-PAGE, and morphology by scanning electron microscopy. The whole genome sequenced C. concisus strain 13826 which was isolated from an individual with bloody diarrhea was included in MLST analysis. Principal Findings MLST analysis showed that 87.5% of individuals whose C. concisus belonged to Cluster I had inflammatory enteric diseases (six IBD and one with bloody diarrhea), which was significantly higher than that in the remaining individuals (28.6%) (P<0.05). Enteric invasive C. concisus (EICC) oral strain was detected in 50% of patients with IBD and none of the controls. All EICC strains were in Cluster 1. The C. concisus strain colonizing intestinal tissues of patient No. 1 was closely related to the oral C. concisus strain from patient No. 6 and had gene recombination with the patient’s own oral C. concisus. The oral and intestinal C. concisus strains of patient No. 3 were the same strain. Some individuals were colonized with multiple oral C. concisus strains that have undergone natural recombination. Conclusions This study provides the first evidence that patients with IBD are colonized with specific oral C. concisus strains, with some being EICC strains. C. concisus colonizing intestinal tissues of patients with IBD at least in some instances results from an endogenous colonization of the patient’s oral C. concisus and that C. concisus strains undergo natural recombination. PMID

  18. Enteric pathogens and antimicrobial resistance in turkey vultures (Cathartes aura) feeding at the wildlife-livestock interface.

    PubMed

    Sulzner, Kate; Kelly, Terra; Smith, Woutrina; Johnson, Christine K

    2014-12-01

    Free-flying turkey vultures (Cathartes aura) were sampled in California to investigate the fecal shedding prevalence and antimicrobial susceptibility of Salmonella enterica, Campylobacter spp., and Escherichia coli. Nine different serotypes of Salmonella enterica were detected in cloacal swabs from turkey vultures, and 6% of vultures were shedding Campylobacter spp.. Turkey vultures sampled at a location with range sheep were more likely to shed tetracycline-resistant E. coli, suggesting that proximity to livestock facilities could facilitate acquisition of drug-resistant bacteria in avian scavengers. These findings illustrate the importance of assessing drug-resistant pathogen transfer at the livestock-wildlife interface. PMID:25632686

  19. Molecular testing for viral and bacterial enteric pathogens: gold standard for viruses, but don't let culture go just yet?

    PubMed

    Bloomfield, Maxim G; Balm, Michelle N D; Blackmore, Timothy K

    2015-04-01

    Contemporary diagnostic microbiology is increasingly adopting molecular methods as front line tests for a variety of samples. This trend holds true for detection of enteric pathogens (EP), where nucleic acid amplification tests (NAAT) for viruses are well established as the gold standard, and an increasing number of commercial multi-target assays are now available for bacteria and parasites. NAAT have significant sensitivity and turnaround time advantages over traditional methods, potentially returning same-day results. Multiplex panels offer an attractive 'one-stop shop' that may provide workflow and cost advantages to laboratories processing large sample volumes. However, there are a number of issues which need consideration. Reflex culture is required for antibiotic susceptibility testing and strain typing when needed for food safety and other epidemiological investigations. Surveillance systems will need to allow for differences in disease incidence due to the enhanced sensitivity of NAAT. Laboratories should be mindful of local epidemiology when selecting which pathogens to include in multiplex panels, and be thoughtful regarding which pathogens will not be detected. Multiplex panels may not be appropriate in certain situations, such as hospital-onset diarrhoea, where Clostridium difficile testing might be all that is required, and laboratories may wish to retain the flexibility to run single tests in such situations. The clinical impact of rapid results is also likely to be relatively minor, as infective diarrhoea is a self-limiting illness in the majority of cases. Laboratories will require strategies to assist users in the interpretation of the results produced by NAAT, particularly where pathogens are detected at low levels with uncertain clinical significance. These caveats aside, faecal NAAT are increasingly being used and introduce a new era of diagnosis of gastrointestinal infection. PMID:25719855

  20. Lactobacillus fermentum isolated from human colonic mucosal biopsy inhibits the growth and adhesion of enteric and foodborne pathogens.

    PubMed

    Varma, Parvathi; Dinesh, Kavitha R; Menon, Krishna K; Biswas, Raja

    2010-01-01

    A number of Lactobacillus species are used as probiotic strains in order to benefit health. We have isolated L. fermentum from human colonic mucosal biopsy samples that possess antimicrobial activities against entroinvasive and foodborne pathogens such as Escherichia coli, Salmonella paratyphi A, Shigella sonnei, Staphylococcus aureus, Enterococcus faecalis, Proteus mirabilis, Pseudomonas aeruginosa, and Vibrio sp. In addition to lactic acid, L. fermentum secretes antimicrobial proteinacious compound(s) that was found to be active even at neutral pH (pH 7.0). The compound was sensitive to heat treatment and trypsin digestion. Lactobacillus fermentum inhibited the adhesion of enteropathogens to intestinal epithelial cells in vitro. Isolated cell surface associated proteins (SAPs) from L. fermentum were sufficient for the adhesion exclusions of enteropathogenic E. coli. Our results indicate that L. fermentum produces antimicrobial compounds and SAPs to inhibit the growth and adhesion of enteropathogens, respectively. PMID:21535608

  1. [Diagnostic value of a novel nutrient medium for isolation and cultivation of pathogens causing enteric yersiniosis and pseudotuberculosis].

    PubMed

    Saiapina, L V; Anisimova, T I; Sergeeva, G M; Kasina, I V; Shvedun, G P; Khramov, M V

    2000-01-01

    A new nutrient medium for isolation and cultivation of the causative agents of enteric yersiniosis and pseudotuberculosis was found to have advantages over Endo medium in its differentiating and inhibiting properties. This medium permitted the easy differentiation of Yersinia pseudotuberculosis from Y. enterocolitica, as well as from Escherichia coli, Shigella flexneri, Klebsiella pneumoniae, K. rhinoscleromatis, Hafnia, Enterobacter and Citrobacter by color; from Proteus inconstans by swarming. In addition, weakly swarming of P. vulgaris differed by their light bluish color and Pseudomonas aeruginosa, by the brilliance and size of colonies. Endo medium could be used only for differentiation of E. coli from lactose-negative Yersinia colonies, Klebsiella (by mucous growth) and, to a certain extent, all Proteus species (by swarming). The medium under test and the control medium inhibited the growth of Staphylococcus aureus. In contrast to Endo medium, the medium under test partially inhibited the growth of K. rhinoscleromatis and the swarming of P. inconstans. The new medium is now introduced into practice. PMID:11210625

  2. SITE RANK

    EPA Science Inventory

    Site rank is formulated for ranking the relative hazard of contamination sources and vulnerability of drinking water wells. Site rank can be used with a variety of groundwater flow and transport models.

  3. In vitro probiotic characterization of Lactobacillus strains from fermented radish and their anti-adherence activity against enteric pathogens.

    PubMed

    Damodharan, Karthiyaini; Palaniyandi, Sasikumar Arunachalam; Yang, Seung Hwan; Suh, Joo-Won

    2015-11-01

    In this study, we evaluated the probiotic properties of Lactobacillus plantarum, Lactobacillus pentosus, and Lactobacillus fermentum strains isolated from fermented radish. All the strains survived the simulated oro-gastrointestinal transit condition and showed significantly higher adherence to Caco-2 cells compared with the probiotic strain Lactobacillus rhamnosus GG. The strains showed broad-spectrum antimicrobial activity, autoaggregation, and coaggregation capacity with pathogens. Furthermore, the Lactobacillus strains inhibited the adherence of Yersinia enterocolitica subsp. enterocolitica, Shigella boydii, and Salmonella choleraesuis to the Caco-2 cell line. The strains possessed bile salt hydrolase activity and their cholesterol-lowering activity in vitro was above 50% in the presence of bile. Strains of L. plantarum and L. pentosus possessed the plantaricin-encoding plnEF gene. In addition, the Lactobacillus strains maintained about 80% cell viability after freeze-drying in the presence of a combination of 5% skim milk and 5% maltodextrin as cryoprotectant, and 70% recovery of cell viability was observed in the absence of any cryoprotectant. PMID:26382558

  4. Low Enteric Colonization with Multidrug-Resistant Pathogens in Soldiers Returning from Deployments- Experience from the Years 2007-2015.

    PubMed

    Frickmann, Hagen; Wiemer, Dorothea; Frey, Claudia; Hagen, Ralf Matthias; Hinz, Rebecca; Podbielski, Andreas; Köller, Thomas; Warnke, Philipp

    2016-01-01

    This assessment describes the enteric colonization of German soldiers 8-12 weeks after returning from mostly but not exclusively subtropical or tropical deployment sites with third-generation cephalosporin-resistant Enterobacteriaceae, vancomycin-resistant enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA). Between 2007 and 2015, 828 stool samples from returning soldiers were enriched in nonselective broth and incubated on selective agars for Enterobacteriaceae expressing extended-spectrum beta-lactamases (ESBL), VRE and MRSA. Identification and resistance testing of suspicious colonies was performed using MALDI-TOF-MS, VITEK-II and agar diffusion gradient testing (bioMérieux, Marcy-l'Étoile, France). Isolates with suspicion of ESBL were characterized by ESBL/ampC disc-(ABCD)-testing and molecular approaches (PCR, Sanger sequencing). Among the returnees, E. coli with resistance against third-generation cephalosporins (37 ESBL, 1 ESBL + ampC, 1 uncertain mechanism) were found in 39 instances (4.7%). Associated quinolone resistance was found in 46.2% of these isolates. Beta-lactamases of the blaCTX-M group 1 predominated among the ESBL mechanisms, followed by the blaCTX-M group 9, and blaSHV. VRE of vanA-type was isolated from one returnee (0.12%). MRSA was not isolated at all. There was no clear trend regarding the distribution of resistant isolates during the assessment period. Compared with colonization with resistant bacteria described in civilians returning from the tropics, the colonization in returned soldiers is surprisingly low and stable. This finding, together with high colonization rates found in previous screenings on deployment, suggests a loss of colonization during the 8- to 12-week period between returning from the deployments and assessment. PMID:27598775

  5. Efficacy of avilamycin for the prevention of necrotic enteritis caused by a pathogenic strain of Clostridium perfringens in broiler chickens.

    PubMed

    Paradis, Marie Anne; McMillan, Ewen; Bagg, Randal; Vessie, Gord; Zocche, Alexandre; Thompson, Michelle

    2016-06-01

    The efficacy of avilamycin for the prevention of necrotic enteritis (NE) was investigated in a 35-day floor pen study of 2200 broiler cockerels using a Clostridium perfringens (Cp) feed inoculum challenge model. Treatments consisted of (1) nonmedicated, nonchallenged; (2) nonmedicated, challenged; (3) avilamycin at 15 ppm, challenged; (4) avilamycin at 30 ppm, challenged. Avilamycin was administered in the feed from day 7 to day 30 of the study. Challenge inoculum was administered on day 14 and delivered approximately 10(9) CFU Cp/bird. NE mortality rates from day 14-35 were significantly (P < 0.0001) lower in birds treated with avilamycin at 15 and 30 ppm when compared to nonmedicated, challenged birds. Treatment with avilamycin also resulted in a significant reduction in ileal Cp count on day 21 (P < 0.0001) and NE lesion scores on day 17 (P < 0.006) when compared to nonmedicated, challenged birds. The performance of birds treated with avilamycin was also improved when compared to nonmedicated, challenged birds. Cockerels that received either 15 or 30 ppm avilamycin had a significantly (P < 0.0001) increased body weight on day 35 and average daily gain from days 0-35 than nonmedicated, challenged birds. Furthermore, birds treated with avilamycin had an improved feed conversion rate from days 0-35 compared to both nonmedicated, nonchallenged birds and nonmedicated, challenged birds. This study confirms that avilamycin is effective at controlling mortality related to NE in growing broiler chickens. PMID:26981841

  6. Commensal bacteria can enter colonic epithelial cells and induce proinflammatory cytokine secretion: a possible pathogenic mechanism of ulcerative colitis.

    PubMed

    Ohkusa, Toshifumi; Yoshida, Tsutomu; Sato, Nobuhiro; Watanabe, Sumio; Tajiri, Hisao; Okayasu, Isao

    2009-05-01

    Interleukin 2 (IL-2)- and IL-10-knockout mice develop spontaneous colitis under conventional but not germ-free conditions, suggesting that commensal bacteria play an important role in the pathogenesis of colitis. However, interactions between commensal bacteria and colonic epithelial cells have not been fully investigated. We therefore assessed the ability of various commensal bacteria and probiotics to adhere to and invade colonic epithelial cells. Effects of the bacteria on production of proinflammatory cytokines were also measured. Commensal bacteria, including mucosal organisms isolated from ulcerative colitis (UC) patients, such as Fusobacterium varium, reported as a possible pathogen in UC, Bacteroides vulgatus, Escherichia coli and Clostridium clostridioforme, as well as their type strains and probiotics, were assessed for their ability to adhere to and invade colonic epithelial cells using two cell lines, SW-480 and HT-29. Our experiments employed co-incubation, a combination of scanning and transmission electron microscopy and recovery of bacteria from infected-cell lysates. F. varium and several other commensal bacteria, but not probiotics, adhered to colonic epithelial cells and invaded their cytoplasm. ELISA and real-time PCR revealed that the host cells, particularly those invaded by F. varium, showed significant increases in IL-8 and TNF-alpha concentrations in supernatants, with elevation of IL-8, TNF-alpha, MCP-1 and IL-6 mRNAs. Furthermore, IL-8 and TNF-alpha expression and nuclear phosphorylated NF-kappaB p65 expression could be immunohistochemically confirmed in inflamed epithelium with cryptitis or crypt abscess in UC patients. Certain commensal bacteria can invade colonic epithelial cells, activating early intracellular signalling systems to trigger host inflammatory reactions. PMID:19369513

  7. Risk ranking of pathogens in ready-to-eat unprocessed foods of non-animal origin (FoNAO) in the EU: initial evaluation using outbreak data (2007-2011).

    PubMed

    Da Silva Felício, M T; Hald, T; Liebana, E; Allende, A; Hugas, M; Nguyen-The, C; Johannessen, G Skoien; Niskanen, T; Uyttendaele, M; McLauchlin, J

    2015-02-16

    Foods of non-animal origin (FoNAO) are consumed in a variety of forms, being a major component of almost all meals. These food types have the potential to be associated with large outbreaks as seen in 2011 associated with VTEC O104. In order to identify and rank specific food/pathogen combinations most often linked to human cases originating from FoNAO in the EU, a semi-quantitative model was developed using seven criteria: strength of associations between food and pathogen based on the foodborne outbreak data from EU Zoonoses Monitoring (2007-2011), incidence of illness, burden of disease, dose-response relationship, consumption, prevalence of contamination and pathogen growth potential during shelf life. The top ranking food/pathogen combination was Salmonella spp. and leafy greens eaten raw followed by (in equal rank) Salmonella spp. and bulb and stem vegetables, Salmonella spp. and tomatoes, Salmonella spp. and melons, and pathogenic Escherichia coli and fresh pods, legumes or grains. Despite the inherent assumptions and limitations, this risk model is considered a tool for risk managers, as it allows ranking of food/pathogen combinations most often linked to foodborne human cases originating from FoNAO in the EU. Efforts to collect additional data even in the absence of reported outbreaks as well as to enhance the quality of the EU-specific data, which was used as input for all the model criteria, will allow the improvement of the model outputs. Furthermore, it is recommended that harmonised terminology be applied to the categorisation of foods collected for different reasons, e.g. monitoring, surveillance, outbreak investigation and consumption. In addition, to assist future microbiological risk assessments, consideration should be given to the collection of additional information on how food has been processed, stored and prepared as part of the above data collection exercises. PMID:25500275

  8. Evaluation of the NanoCHIP® Gastrointestinal Panel (GIP) Test for Simultaneous Detection of Parasitic and Bacterial Enteric Pathogens in Fecal Specimens

    PubMed Central

    Ken Dror, Shifra; Pavlotzky, Elsa; Barak, Mira

    2016-01-01

    Infectious gastroenteritis is a global health problem associated with high morbidity and mortality rates. Rapid and accurate diagnosis is crucial to allow appropriate and timely treatment. Current laboratory stool testing has a long turnaround time (TAT) and demands highly qualified personnel and multiple techniques. The need for high throughput and the number of possible enteric pathogens compels the implementation of a molecular approach which uses multiplex technology, without compromising performance requirements. In this work we evaluated the feasibility of the NanoCHIP® Gastrointestinal Panel (GIP) (Savyon Diagnostics, Ashdod, IL), a molecular microarray-based screening test, to be used in the routine workflow of our laboratory, a big outpatient microbiology laboratory. The NanoCHIP® GIP test provides simultaneous detection of nine major enteric bacteria and parasites: Campylobacter spp., Salmonella spp., Shigella spp., Giardia sp., Cryptosporidium spp., Entamoeba histolytica, Entamoeba dispar, Dientamoeba fragilis, and Blastocystis spp. The required high-throughput was obtained by the NanoCHIP® detection system together with the MagNA Pure 96 DNA purification system (Roche Diagnostics Ltd., Switzerland). This combined system has demonstrated a higher sensitivity and detection yield compared to the conventional methods in both, retrospective and prospective samples. The identification of multiple parasites and bacteria in a single test also enabled increased efficiency of detecting mixed infections, as well as reduced hands-on time and work load. In conclusion, the combination of these two automated systems is a proper response to the laboratory needs in terms of improving laboratory workflow, turn-around-time, minimizing human errors and can be efficiently integrated in the routine work of the laboratory. PMID:27447173

  9. Evaluation of the NanoCHIP® Gastrointestinal Panel (GIP) Test for Simultaneous Detection of Parasitic and Bacterial Enteric Pathogens in Fecal Specimens.

    PubMed

    Ken Dror, Shifra; Pavlotzky, Elsa; Barak, Mira

    2016-01-01

    Infectious gastroenteritis is a global health problem associated with high morbidity and mortality rates. Rapid and accurate diagnosis is crucial to allow appropriate and timely treatment. Current laboratory stool testing has a long turnaround time (TAT) and demands highly qualified personnel and multiple techniques. The need for high throughput and the number of possible enteric pathogens compels the implementation of a molecular approach which uses multiplex technology, without compromising performance requirements. In this work we evaluated the feasibility of the NanoCHIP® Gastrointestinal Panel (GIP) (Savyon Diagnostics, Ashdod, IL), a molecular microarray-based screening test, to be used in the routine workflow of our laboratory, a big outpatient microbiology laboratory. The NanoCHIP® GIP test provides simultaneous detection of nine major enteric bacteria and parasites: Campylobacter spp., Salmonella spp., Shigella spp., Giardia sp., Cryptosporidium spp., Entamoeba histolytica, Entamoeba dispar, Dientamoeba fragilis, and Blastocystis spp. The required high-throughput was obtained by the NanoCHIP® detection system together with the MagNA Pure 96 DNA purification system (Roche Diagnostics Ltd., Switzerland). This combined system has demonstrated a higher sensitivity and detection yield compared to the conventional methods in both, retrospective and prospective samples. The identification of multiple parasites and bacteria in a single test also enabled increased efficiency of detecting mixed infections, as well as reduced hands-on time and work load. In conclusion, the combination of these two automated systems is a proper response to the laboratory needs in terms of improving laboratory workflow, turn-around-time, minimizing human errors and can be efficiently integrated in the routine work of the laboratory. PMID:27447173

  10. Emerging trends in the etiology of enteric pathogens as evidenced from an active surveillance of hospitalized diarrhoeal patients in Kolkata, India

    PubMed Central

    2010-01-01

    Background This study was conducted to determine the etiology of diarrhoea in a hospital setting in Kolkata. Active surveillance was conducted for 2 years on two random days per week by enrolling every fifth diarrhoeal patient admitted to the Infectious Diseases and Beliaghata General Hospital in Kolkata. Results Most of the patients (76.1%) had acute watery diarrhoea in association with vomiting (77.7%) and some dehydration (92%). Vibrio cholerae O1, Rotavirus and Giardia lamblia were the important causes of diarrhoea. Among Shigella spp, S. flexneri 2a and 3a serotypes were most predominantly isolated. Enteric viruses, EPEC and EAEC were common in children <5 year age group. Atypical EPEC was comparatively higher than the typical EPEC. Multidrug resistance was common among V. cholerae O1 and Shigella spp including tetracycline and ciprofloxacin. Polymicrobial infections were common in all age groups and 27.9% of the diarrhoea patients had no potential pathogen. Conclusions Increase in V. cholerae O1 infection among <2 years age group, resistance of V. cholerae O1 to tetracycline, rise of untypable S. flexnerii, higher proportion of atypical EPEC and G. lamblia and polymicrobial etiology are some of the emerging trends observed in this diarrhoeal disease surveillance. PMID:20525383

  11. Bacterial cell surface hydrophobicity properties in the mediation of in vitro adhesion by the rabbit enteric pathogen Escherichia coli strain RDEC-1.

    PubMed Central

    Drumm, B; Neumann, A W; Policova, Z; Sherman, P M

    1989-01-01

    The role of hydrophobicity in the attachment of enteropathogens to gastrointestinal mucosa is controversial. In vitro binding of Escherichia coli RDEC-1 to rabbit intestine is dependent on the expression of pili. We examined in vitro adherence of piliated RDEC-1 after altering either the hydrophobicity of the organisms, the hydrophobicity of the substrate for attachment, or the surface tension of the suspending liquid. Hydrophobicity of RDEC-1 was determined using four complementary methods. In each assay piliated RDEC-1 demonstrated relatively more hydrophobic properties compared with both organisms grown to suppress pilus expression and a mutant that cannot express mannose-resistant pili. When piliated RDEC-1 were pretreated with tetramethyl urea to disrupt hydrophobic bonds surface hydrophobicity decreased. Concurrently, bacterial adherence to rabbit ileal microvillus membranes, mucus and mucin was reduced. Binding of piliated organisms to hydrophobic surfaces was significantly higher compared to both nonpiliated bacteria and the adherence of piliated RDEC-1 to relatively hydrophilic surfaces. Addition of propanol reduced the surface tension of the suspending liquid, and decreased adhesion of piliated RDEC-1 to polystyrene by 80%. Conversely, adherence of piliated organisms to a hydrophilic surface increased 12-fold after lowering the surface tension of the suspending liquid. We conclude that hydrophobic properties have a role in mediating in vitro adherence of this E. coli enteric pathogen. Images PMID:2572606

  12. Evaluation of a Multiplex Real-Time PCR Assay for Detecting Major Bacterial Enteric Pathogens in Fecal Specimens: Intestinal Inflammation and Bacterial Load Are Correlated in Campylobacter Infections.

    PubMed

    Wohlwend, Nadia; Tiermann, Sacha; Risch, Lorenz; Risch, Martin; Bodmer, Thomas

    2016-09-01

    A total of 1,056 native or Cary-Blair-preserved stool specimens were simultaneously tested by conventional stool culturing and by enteric bacterial panel (EBP) multiplex real-time PCR for Campylobacter jejuni, Campylobacter coli, Salmonella spp., and shigellosis disease-causing agents (Shigella spp. and enteroinvasive Escherichia coli [EIEC]). Overall, 143 (13.5%) specimens tested positive by PCR for the targets named above; 3 coinfections and 109 (10.4%) Campylobacter spp., 17 (1.6%) Salmonella spp., and 20 (1.9%) Shigella spp./EIEC infections were detected. The respective positive stool culture rates were 75 (7.1%), 14 (1.3%), and 7 (0.7%). The median threshold cycle (CT) values of culture-positive specimens were significantly lower than those of culture-negative ones (CT values, 24.3 versus 28.7; P < 0.001), indicating that the relative bacterial load per fecal specimen was significantly associated with the culture results. In Campylobacter infections, the respective median fecal calprotectin concentrations in PCR-negative/culture-negative (n = 40), PCR-positive/culture-negative (n = 14), and PCR-positive/culture-positive (n = 15) specimens were 134 mg/kg (interquartile range [IQR], 30 to 1,374 mg/kg), 1,913 mg/kg (IQR, 165 to 3,813 mg/kg), and 5,327 mg/kg (IQR, 1,836 to 18,213 mg/kg). Significant differences were observed among the three groups (P < 0.001), and a significant linear trend was identified (P < 0.001). Furthermore, the fecal calprotectin concentrations and CT values were found to be correlated (r = -0.658). Our results demonstrate that molecular screening of Campylobacter spp., Salmonella spp., and Shigella spp./EIEC using the BD Max EBP assay will result in timely diagnosis and improved sensitivity. The determination of inflammatory markers, such as calprotectin, in fecal specimens may aid in the interpretation of PCR results, particularly for enteric pathogens associated with mucosal damage and colonic inflammation. PMID:27307458

  13. Rank Dynamics

    NASA Astrophysics Data System (ADS)

    Gershenson, Carlos

    Studies of rank distributions have been popular for decades, especially since the work of Zipf. For example, if we rank words of a given language by use frequency (most used word in English is 'the', rank 1; second most common word is 'of', rank 2), the distribution can be approximated roughly with a power law. The same applies for cities (most populated city in a country ranks first), earthquakes, metabolism, the Internet, and dozens of other phenomena. We recently proposed ``rank diversity'' to measure how ranks change in time, using the Google Books Ngram dataset. Studying six languages between 1800 and 2009, we found that the rank diversity curves of languages are universal, adjusted with a sigmoid on log-normal scale. We are studying several other datasets (sports, economies, social systems, urban systems, earthquakes, artificial life). Rank diversity seems to be universal, independently of the shape of the rank distribution. I will present our work in progress towards a general description of the features of rank change in time, along with simple models which reproduce it

  14. Entering Research

    ERIC Educational Resources Information Center

    Lawless, Ann; Sedorkin, Barbara

    2007-01-01

    This article presents a short story of the authors, who show how they have "entered research", that is, entered the earliest conception of research and the early formation of research collaboration. As the authors worked together, they realised they had common concerns and life experiences. Each proudly identifies as working class Australian, each…

  15. Viral enteric infections of poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enteric diseases cause great economic losses to the poultry industry mostly from depressed weight gains, impaired feed efficiency, and decreased flock uniformity. Enteric syndromes have been described in both young turkeys and chickens and likely result from infection by a mixture of pathogenic age...

  16. “Candidatus Hepatobacter penaei,” an Intracellular Pathogenic Enteric Bacterium in the Hepatopancreas of the Marine Shrimp Penaeus vannamei (Crustacea: Decapoda)

    PubMed Central

    Pantoja, Carlos R.; Gomez-Jimenez, Silvia; Lightner, Donald V.

    2013-01-01

    The bacteria that cause necrotizing hepatopancreatitis in Penaeus vannamei adversely affect penaeid shrimp cultured in the western hemisphere. 16S rRNA and gyrase B gene analyses determined the taxonomic position of these bacteria. The name “Candidatus Hepatobacter penaei” is proposed for these pathogenic bacteria, which are members of the Rickettsiales order. PMID:23241970

  17. Low-rank coal oil agglomeration

    DOEpatents

    Knudson, Curtis L.; Timpe, Ronald C.

    1991-01-01

    A low-rank coal oil agglomeration process. High mineral content, a high ash content subbituminous coals are effectively agglomerated with a bridging oil which is partially water soluble and capable of entering the pore structure, and usually coal derived.

  18. Lactobacillus paracasei CBA L74 metabolic products and fermented milk for infant formula have anti-inflammatory activity on dendritic cells in vitro and protective effects against colitis and an enteric pathogen in vivo.

    PubMed

    Zagato, Elena; Mileti, Erika; Massimiliano, Lucia; Fasano, Francesca; Budelli, Andrea; Penna, Giuseppe; Rescigno, Maria

    2014-01-01

    The rapid expansion of commercially available fermented food products raises important safety issues particularly when infant food is concerned. In many cases, the activity of the microorganisms used for fermentation as well as what will be the immunological outcome of fermented food intake is not known. In this manuscript we used complex in vitro, ex-vivo and in vivo systems to study the immunomodulatory properties of probiotic-fermented products (culture supernatant and fermented milk without live bacteria to be used in infant formula). We found in vitro and ex-vivo that fermented products of Lactobacillus paracasei CBA L74 act via the inhibition of proinflammatory cytokine release leaving anti-inflammatory cytokines either unaffected or even increased in response to Salmonella typhimurium. These activities are not dependent on the inactivated bacteria but to metabolic products released during the fermentation process. We also show that our in vitro systems are predictive of an in vivo efficacy by the fermented products. Indeed CBA L74 fermented products (both culture medium and fermented milk) could protect against colitis and against an enteric pathogen infection (Salmonella typhimurium). Hence we found that fermented products can act via the inhibition of immune cell inflammation and can protect the host from pathobionts and enteric pathogens. These results open new perspectives in infant nutrition and suggest that L. paracasei CBA L74 fermented formula can provide immune benefits to formula-fed infants, without carrying live bacteria that may be potentially dangerous to an immature infant immune system. PMID:24520333

  19. Tuberculous Enteritis

    PubMed Central

    Hill, George S.; Tabrisky, Joseph; Peter, Michael E.

    1976-01-01

    Tuberculous enteritis occurs in about 2 percent of patients with pulmonary tuberculosis. Although it is uncommon in the United States, tuberculous enteritis should be considered in any patient with active pulmonary tuberculosis and abdominal complaints. Eight cases of T. enteritis have been treated at Harbor General Hospital in the last 25 years. Associated pulmonary disease was shown radiologically to be present in seven of eight patients. Findings on contrast studies of the gastrointestinal tract showed disease in six of six patients examined. In five patients, surgical operation was required for diagnosis or complications. Resection of diseased bowel with primary anastomosis was done in five patients. Although medical therapy is the mainstay in the treatment of both pulmonary and intestinal tuberculosis, one staged resection of diseased bowel with primary anastomosis is the procedure of choice for complications such as obstruction, hemorrhage or perforation. ImagesFigure 1.Figure 2. PMID:936600

  20. Radiation enteritis

    SciTech Connect

    O'Brien, P.H.; Jenrette, J.M. III; Garvin, A.J.

    1987-09-01

    As the population receiving radiation therapy grows, so does the incidence of chronic radiation enteritis. A review of the pathology of chronic radiation enteritis reveals fibrosis, endarteritis, edema, fragility, perforation, and partial obstruction. Conservative management of patients with this disease is common. Because the obstruction is only partial, decompression is easily achieved with nasogastric suction and parenteral support. The patient is then often discharged on a liquid-to-soft diet. This therapeutic strategy does nothing for the underlying pathology. The problem, sooner or later, will return with the patient further depleted by the chronic radiation enteritis. We think surgical intervention is appropriate when the diagnosis of chronic radiation enteritis is assumed. The surgery in relation to this disease is high risk with a 30% mortality and 100% expensive morbidity. Early intervention seems to decrease these figures. All anastomoses, if possible, should be outside the irradiated area. Trapped pelvic loops of intestine should be left in place and a bypass procedure with decompressing enterostomies accomplished. The surgery should be performed by a surgeon with extensive experience with all kinds of bowel obstruction as well as experience in performing surgery in radiated tissue.

  1. Enteric viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Characteristic clinical signs associated with viral enteritis in young poultry include diarrhea, anorexia, litter eating, ruffled feathers, and poor growth. Intestines may have lesions; intestines are typically dilated and are filled with fluid and gaseous contents. The sequela to clinical disease...

  2. Influence of the Plant Defense Response to Escherichia coli O157:H7 Cell Surface Structures on Survival of That Enteric Pathogen on Plant Surfaces

    PubMed Central

    Seo, Suengwook

    2012-01-01

    Consumption of fresh and fresh-cut fruits and vegetables contaminated with Escherichia coli O157:H7 has resulted in hundreds of cases of illness and, in some instances, death. In this study, the influence of cell surface structures of E. coli O157:H7, such as flagella, curli fimbriae, lipopolysaccharides, or exopolysaccharides, on plant defense responses and on survival or colonization on the plant was investigated. The population of the E. coli O157:H7 ATCC 43895 wild-type strain was significantly lower on wild-type Arabidopsis plants than that of the 43895 flagellum-deficient mutant. The population of the E. coli O157:H7 43895 flagellum mutant was greater on both wild-type and npr1-1 mutant (nonexpressor of pathogenesis-related [PR] genes) plants and resulted in less PR gene induction, estimated based on a weak β-glucuronidase (GUS) signal, than did the 43895 wild-type strain. These results suggest that the flagella, among the other pathogen-associated molecular patterns (PAMPs), made a substantial contribution to the induction of plant defense response and contributed to the decreased numbers of the E. coli O157:H7 ATCC 43895 wild-type strain on the wild-type Arabidopsis plant. A curli-deficient E. coli O157:H7 86-24 strain survived better on wild-type Arabidopsis plants than the curli-producing wild-type 86-24 strain did. The curli-deficient E. coli O157:H7 86-24 strain exhibited a GUS signal at a level substantially lower than that of the curli-producing wild-type strain. Curli were recognized by plant defense systems, consequently affecting bacterial survival. The cell surface structures of E. coli O157:H7 have a significant impact on the induction of differential plant defense responses, thereby impacting persistence or survival of the pathogen on plants. PMID:22706044

  3. Transcriptional Profiles of Host-Pathogen Responses to Necrotic Enteritis and Differential Regulation of Immune Genes in Two Inbreed Chicken Lines Showing Disparate Disease Susceptibility

    PubMed Central

    Kim, Duk Kyung; Lillehoj, Hyun S.; Jang, Seung I.; Lee, Sung Hyen; Hong, Yeong Ho; Cheng, Hans H.

    2014-01-01

    Necrotic enteritis (NE) is an important intestinal infectious disease of commercial poultry flocks caused by Clostridium perfringens. Using an experimental model of NE involving co-infection with C. perfringens and Eimeria maxima, transcriptome profiling and functional genomics approaches were applied to identify the genetic mechanisms that might regulate the host response to this disease. Microarray hybridization identified 1,049 transcripts whose levels were altered (601 increased, 448 decreased) in intestinal lymphocytes from C. perfringens/E. maxima co-infected Ross chickens compared with uninfected controls. Five biological functions, all related to host immunity and inflammation, and 11 pathways were identified from this dataset. To further elucidate the role of host genetics in NE susceptibility, two inbred chicken lines, ADOL line 6 and line 7 which share an identical B2 major histocompatibility complex haplotype but differ in their susceptibility to virus infection, were compared for clinical symptoms and the expression levels of a panel of immune-related genes during experimental NE. Line 6 chickens were more susceptible to development of experimental NE compared with line 7, as revealed by decreased body weight gain and increased E. maxima oocyst shedding. Of 21 immune-related genes examined, 15 were increased in C. perfringens/E. maxima co-infected line 6 vs. line 7 chickens. These results suggest that immune pathways are activated in response to experimental NE infection and that genetic determinants outside of the chicken B complex influence resistance to this disease. PMID:25504150

  4. When Does Rank(ABC)= Rank(AB) + Rank(BC) - Rank(B) Hold?

    ERIC Educational Resources Information Center

    Tian, Yongge; Styan, George P. H.

    2002-01-01

    The well-known Frobenius rank inequality established by Frobenius in 1911 states that the rank of the product ABC of three matrices satisfies the inequality rank(ABC) [greater than or equal]rank(AB) + rank(BC) - rank(B) A new necessary and sufficient condition for equality to hold is presented and then some interesting consequences and…

  5. Arabidopsis PEN3/PDR8, an ATP Binding Cassette Transporter, Contributes to Nonhost Resistance to Inappropriate Pathogens That Enter by Direct Penetration[W][OA

    PubMed Central

    Stein, Mónica; Dittgen, Jan; Sánchez-Rodríguez, Clara; Hou, Bi-Huei; Molina, Antonio; Schulze-Lefert, Paul; Lipka, Volker; Somerville, Shauna

    2006-01-01

    Arabidopsis thaliana is a host to the powdery mildew Erysiphe cichoracearum and nonhost to Blumeria graminis f. sp hordei, the powdery mildew pathogenic on barley (Hordeum vulgare). Screening for Arabidopsis mutants deficient in resistance to barley powdery mildew identified PENETRATION3 (PEN3). pen3 plants permitted both increased invasion into epidermal cells and initiation of hyphae by B. g. hordei, suggesting that PEN3 contributes to defenses at the cell wall and intracellularly. pen3 mutants were compromised in resistance to the necrotroph Plectosphaerella cucumerina and to two additional inappropriate biotrophs, pea powdery mildew (Erysiphe pisi) and potato late blight (Phytophthora infestans). Unexpectedly, pen3 mutants were resistant to E. cichoracearum. This resistance was salicylic acid–dependent and correlated with chlorotic patches. Consistent with this observation, salicylic acid pathway genes were hyperinduced in pen3 relative to the wild type. The phenotypes conferred by pen3 result from the loss of function of PLEIOTROPIC DRUG RESISTANCE8 (PDR8), a highly expressed putative ATP binding cassette transporter. PEN3/PDR8 tagged with green fluorescent protein localized to the plasma membrane in uninfected cells. In infected leaves, the protein concentrated at infection sites. PEN3/PDR8 may be involved in exporting toxic materials to attempted invasion sites, and intracellular accumulation of these toxins in pen3 may secondarily activate the salicylic acid pathway. PMID:16473969

  6. Analysis of the Contribution of Salmonella Pathogenicity Islands 1 and 2 to Enteric Disease Progression Using a Novel Bovine Ileal Loop Model and a Murine Model of Infectious Enterocolitis

    PubMed Central

    Coombes, Brian K.; Coburn, Bryan A.; Potter, Andrew A.; Gomis, Susantha; Mirakhur, Kuldip; Li, Yuling; Finlay, B. Brett

    2005-01-01

    We have developed a novel ileal loop model for use in calves to analyze the contribution of Salmonella enterica serovar Typhimurium type III secretion systems to disease processes in vivo. Our model involves constructing ileal loops with end-to-end anastamoses to restore the patency of the small intestine, thereby allowing experimental animals to convalesce following surgery for the desired number of days. This model overcomes the time constraint imposed by ligated ileal loop models that have precluded investigation of Salmonella virulence factors during later stages of the infection process. Here, we have used this model to examine the enteric disease process at 24 h and 5 days following infection with wild-type Salmonella and mutants lacking the virulence-associated Salmonella pathogenicity island 1 (SPI-1) or SPI-2 type III secretion systems. We show that SPI-2 mutants are dramatically attenuated at 5 days following infection and report a new phenotype for SPI-1 mutants, which induce intestinal pathology in calves similar to wild-type Salmonella in the 5-day ileal loop model. Both of these temporal phenotypes for SPI-1 and SPI-2 mutants were corroborated in a second animal model of enteric disease using streptomycin-pretreated mice. These data delineate novel phenotypes for SPI-1 and SPI-2 mutants in the intestinal phase of bovine and murine salmonellosis and provide working models to further investigate the effector contribution to these pathologies. PMID:16239510

  7. WATERBORNE PATHOGENS IN URBAN WATERSHEDS

    EPA Science Inventory

    Pathogens are microorganisms that can cause sickness or even death. A serious concern for managers of water resources, pathogens in the urban environment easily enter waters through a number of pathways, including discharge of inadequately treated sewage, stormwater runoff, combi...

  8. Low-rank coal oil agglomeration

    DOEpatents

    Knudson, C.L.; Timpe, R.C.

    1991-07-16

    A low-rank coal oil agglomeration process is described. High mineral content, a high ash content subbituminous coals are effectively agglomerated with a bridging oil which is partially water soluble and capable of entering the pore structure, and is usually coal-derived.

  9. Playing the Rankings Game.

    ERIC Educational Resources Information Center

    Machung, Anne

    1998-01-01

    The "U.S. News and World Report" rankings of colleges do not affect institutions equally; the schools impacted most are those that have the most to lose because they benefit from, even rely on, the rankings for prestige and visibility. The magazine relies on the rankings for substantial sales revenues, and has garnered considerable power within…

  10. Order-Theoretical Ranking.

    ERIC Educational Resources Information Center

    Carpineto, Claudio; Romano, Giovanni

    2000-01-01

    Presents an approach to document ranking that explicitly addresses the word mismatch problem between a query and a document by exploiting interdocument similarity information, based on the theory of concept lattices. Compares information retrieval using concept lattice-based ranking (CLR) to BMR (best-match ranking) and HCR (hierarchical…

  11. Quantum anonymous ranking

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Wen, Qiao-Yan; Liu, Bin; Su, Qi; Qin, Su-Juan; Gao, Fei

    2014-03-01

    Anonymous ranking is a kind of privacy-preserving ranking whereby each of the involved participants can correctly and anonymously get the rankings of his data. It can be utilized to solve many practical problems, such as anonymously ranking the students' exam scores. We investigate the issue of how quantum mechanics can be of use in maintaining the anonymity of the participants in multiparty ranking and present a series of quantum anonymous multiparty, multidata ranking protocols. In each of these protocols, a participant can get the correct rankings of his data and nobody else can match the identity to his data. Furthermore, the security of these protocols with respect to different kinds of attacks is proved.

  12. Necrotic enteritis in young calves.

    PubMed

    Morris, Winston E; Venzano, Agustín J; Elizondo, Ana; Vilte, Daniel A; Mercado, Elsa C; Fernandez-Miyakawa, Mariano E

    2011-03-01

    Non-enterotoxin (CPE)-producing Clostridium perfringens type A has been associated with enteritis in calves. Recent evidence has suggested that a novel toxin, named beta2 (CPB2), is implicated in the pathogenesis of this disease, although there is little evidence supporting this. In the current study, the role of C. perfringens type A in an outbreak of enteritis in calves was studied. Two 20-day-old dairy calves exhibiting apathy and reluctance to eat, with paresis of the anterior limbs, were euthanized for postmortem examination. Gross and histological changes compatible with acute enteritis, rumenitis, meningitis, and pneumonia were seen in both calves. Clostridium perfringens type A non-CPE, non-CPB2 was isolated from the abomasum and the small intestine. Escherichia coli ONTH8 (with cdtBIII and f17 virulence genes detected by polymerase chain reaction) was also isolated from the brain, abomasum, and intestine from both calves. All the samples were negative for Salmonella spp. When the C. perfringens strain was inoculated into bovine ligated small and large intestinal loops, cell detachment, erosion, and hemorrhage of the lamina propria were observed, predominantly in the small intestine. The results suggest that non-CPE, non-CPB2 C. perfringens type A is able to induce pathologic changes in the intestine of calves, probably enhanced by other pathogens, such as some pathogenic E. coli strains. PMID:21398444

  13. How to Rank Journals

    PubMed Central

    Bradshaw, Corey J. A.; Brook, Barry W.

    2016-01-01

    There are now many methods available to assess the relative citation performance of peer-reviewed journals. Regardless of their individual faults and advantages, citation-based metrics are used by researchers to maximize the citation potential of their articles, and by employers to rank academic track records. The absolute value of any particular index is arguably meaningless unless compared to other journals, and different metrics result in divergent rankings. To provide a simple yet more objective way to rank journals within and among disciplines, we developed a κ-resampled composite journal rank incorporating five popular citation indices: Impact Factor, Immediacy Index, Source-Normalized Impact Per Paper, SCImago Journal Rank and Google 5-year h-index; this approach provides an index of relative rank uncertainty. We applied the approach to six sample sets of scientific journals from Ecology (n = 100 journals), Medicine (n = 100), Multidisciplinary (n = 50); Ecology + Multidisciplinary (n = 25), Obstetrics & Gynaecology (n = 25) and Marine Biology & Fisheries (n = 25). We then cross-compared the κ-resampled ranking for the Ecology + Multidisciplinary journal set to the results of a survey of 188 publishing ecologists who were asked to rank the same journals, and found a 0.68–0.84 Spearman’s ρ correlation between the two rankings datasets. Our composite index approach therefore approximates relative journal reputation, at least for that discipline. Agglomerative and divisive clustering and multi-dimensional scaling techniques applied to the Ecology + Multidisciplinary journal set identified specific clusters of similarly ranked journals, with only Nature & Science separating out from the others. When comparing a selection of journals within or among disciplines, we recommend collecting multiple citation-based metrics for a sample of relevant and realistic journals to calculate the composite rankings and their relative uncertainty windows. PMID:26930052

  14. How to Rank Journals.

    PubMed

    Bradshaw, Corey J A; Brook, Barry W

    2016-01-01

    There are now many methods available to assess the relative citation performance of peer-reviewed journals. Regardless of their individual faults and advantages, citation-based metrics are used by researchers to maximize the citation potential of their articles, and by employers to rank academic track records. The absolute value of any particular index is arguably meaningless unless compared to other journals, and different metrics result in divergent rankings. To provide a simple yet more objective way to rank journals within and among disciplines, we developed a κ-resampled composite journal rank incorporating five popular citation indices: Impact Factor, Immediacy Index, Source-Normalized Impact Per Paper, SCImago Journal Rank and Google 5-year h-index; this approach provides an index of relative rank uncertainty. We applied the approach to six sample sets of scientific journals from Ecology (n = 100 journals), Medicine (n = 100), Multidisciplinary (n = 50); Ecology + Multidisciplinary (n = 25), Obstetrics & Gynaecology (n = 25) and Marine Biology & Fisheries (n = 25). We then cross-compared the κ-resampled ranking for the Ecology + Multidisciplinary journal set to the results of a survey of 188 publishing ecologists who were asked to rank the same journals, and found a 0.68-0.84 Spearman's ρ correlation between the two rankings datasets. Our composite index approach therefore approximates relative journal reputation, at least for that discipline. Agglomerative and divisive clustering and multi-dimensional scaling techniques applied to the Ecology + Multidisciplinary journal set identified specific clusters of similarly ranked journals, with only Nature & Science separating out from the others. When comparing a selection of journals within or among disciplines, we recommend collecting multiple citation-based metrics for a sample of relevant and realistic journals to calculate the composite rankings and their relative uncertainty windows. PMID:26930052

  15. Low-rank coal research: Volume 3, Combustion research: Final report. [Great Plains

    SciTech Connect

    Mann, M. D.; Hajicek, D. R.; Zobeck, B. J.; Kalmanovitch, D. P.; Potas, T. A.; Maas, D. J.; Malterer, T. J.; DeWall, R. A.; Miller, B. G.; Johnson, M. D.

    1987-04-01

    Volume III, Combustion Research, contains articles on fluidized bed combustion, advanced processes for low-rank coal slurry production, low-rank coal slurry combustion, heat engine utilization of low-rank coals, and Great Plains Gasification Plant. These articles have been entered individually into EDB and ERA. (LTN)

  16. Memory Efficient Ranking.

    ERIC Educational Resources Information Center

    Moffat, Alistair; And Others

    1994-01-01

    Describes an approximate document ranking process that uses a compact array of in-memory, low-precision approximations for document length. Combined with another rule for reducing the memory required by partial similarity accumulators, the approximation heuristic allows the ranking of large document collections using less than one byte of memory…

  17. On Rank and Nullity

    ERIC Educational Resources Information Center

    Dobbs, David E.

    2012-01-01

    This note explains how Emil Artin's proof that row rank equals column rank for a matrix with entries in a field leads naturally to the formula for the nullity of a matrix and also to an algorithm for solving any system of linear equations in any number of variables. This material could be used in any course on matrix theory or linear algebra.

  18. Hitting the Rankings Jackpot

    ERIC Educational Resources Information Center

    Chapman, David W.

    2008-01-01

    Recently, Samford University was ranked 27th in the nation in a report released by "Forbes" magazine. In this article, the author relates how the people working at Samford University were surprised at its ranking. Although Samford is the largest privately institution in Alabama, its distinguished academic achievements aren't even well-recognized…

  19. Tool for Ranking Research Options

    NASA Technical Reports Server (NTRS)

    Ortiz, James N.; Scott, Kelly; Smith, Harold

    2005-01-01

    Tool for Research Enhancement Decision Support (TREDS) is a computer program developed to assist managers in ranking options for research aboard the International Space Station (ISS). It could likely also be adapted to perform similar decision-support functions in industrial and academic settings. TREDS provides a ranking of the options, based on a quantifiable assessment of all the relevant programmatic decision factors of benefit, cost, and risk. The computation of the benefit for each option is based on a figure of merit (FOM) for ISS research capacity that incorporates both quantitative and qualitative inputs. Qualitative inputs are gathered and partly quantified by use of the time-tested analytical hierarchical process and used to set weighting factors in the FOM corresponding to priorities determined by the cognizant decision maker(s). Then by use of algorithms developed specifically for this application, TREDS adjusts the projected benefit for each option on the basis of levels of technical implementation, cost, and schedule risk. Based partly on Excel spreadsheets, TREDS provides screens for entering cost, benefit, and risk information. Drop-down boxes are provided for entry of qualitative information. TREDS produces graphical output in multiple formats that can be tailored by users.

  20. Recurrent fuzzy ranking methods

    NASA Astrophysics Data System (ADS)

    Hajjari, Tayebeh

    2012-11-01

    With the increasing development of fuzzy set theory in various scientific fields and the need to compare fuzzy numbers in different areas. Therefore, Ranking of fuzzy numbers plays a very important role in linguistic decision-making, engineering, business and some other fuzzy application systems. Several strategies have been proposed for ranking of fuzzy numbers. Each of these techniques has been shown to produce non-intuitive results in certain case. In this paper, we reviewed some recent ranking methods, which will be useful for the researchers who are interested in this area.

  1. Enteric virus and vibrio contamination of shellfish: intervention strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    INTRODUCTION. Molluscan shellfish include oysters, clams, mussels, and cockles, which can cause illnesses from a variety of human pathogens. Enteric viruses, like norovirus and hepatitis A virus, are generally transmitted to shellfish through fecal contamination of shellfish harvesting areas, alth...

  2. Multiplex PageRank.

    PubMed

    Halu, Arda; Mondragón, Raúl J; Panzarasa, Pietro; Bianconi, Ginestra

    2013-01-01

    Many complex systems can be described as multiplex networks in which the same nodes can interact with one another in different layers, thus forming a set of interacting and co-evolving networks. Examples of such multiplex systems are social networks where people are involved in different types of relationships and interact through various forms of communication media. The ranking of nodes in multiplex networks is one of the most pressing and challenging tasks that research on complex networks is currently facing. When pairs of nodes can be connected through multiple links and in multiple layers, the ranking of nodes should necessarily reflect the importance of nodes in one layer as well as their importance in other interdependent layers. In this paper, we draw on the idea of biased random walks to define the Multiplex PageRank centrality measure in which the effects of the interplay between networks on the centrality of nodes are directly taken into account. In particular, depending on the intensity of the interaction between layers, we define the Additive, Multiplicative, Combined, and Neutral versions of Multiplex PageRank, and show how each version reflects the extent to which the importance of a node in one layer affects the importance the node can gain in another layer. We discuss these measures and apply them to an online multiplex social network. Findings indicate that taking the multiplex nature of the network into account helps uncover the emergence of rankings of nodes that differ from the rankings obtained from one single layer. Results provide support in favor of the salience of multiplex centrality measures, like Multiplex PageRank, for assessing the prominence of nodes embedded in multiple interacting networks, and for shedding a new light on structural properties that would otherwise remain undetected if each of the interacting networks were analyzed in isolation. PMID:24205186

  3. Enteric viruses of poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the economic importance of the poultry gut, very little is known about the complex gut microbial community. Enteric disease syndromes such as Runting-Stunting Syndrome (RSS) in broiler chickens and Poult Enteritis Complex (PEC) in young turkeys are difficult to characterize and reproduce in ...

  4. A cross-sectional study examining Campylobacter and other zoonotic enteric pathogens in dogs that frequent dog parks in three cities in south-western Ontario and risk factors for shedding of Campylobacter spp.

    PubMed

    Procter, T D; Pearl, D L; Finley, R L; Leonard, E K; Janecko, N; Reid-Smith, R J; Weese, J S; Peregrine, A S; Sargeant, J M

    2014-05-01

    An estimated 6 million pet dogs live in Canadian households with the potential to transmit zoonotic pathogens to humans. Dogs have been identified as carriers of Salmonella, Giardia and Campylobacter spp., particularly Campylobacter upsaliensis, but little is known about the prevalence and risk factors for these pathogens in pet dogs that visit dog parks. This study examined the prevalence of these organisms in the faeces of dogs visiting dog parks in three cities in south-western Ontario, as well as risk factors for shedding Campylobacter spp. and C. upsaliensis. From May to August 2009, canine faecal samples were collected at ten dog parks in the cities of Guelph and Kitchener-Waterloo, Ontario, Canada. Owners were asked to complete a questionnaire related to pet characteristics and management factors including age, diet and activities in which the dog participates. Faecal samples were collected from 251 dogs, and 189 questionnaires were completed. Salmonella, Giardia and Campylobacter spp. were present in 1.2%, 6.4% and 43.0% of faecal samples, respectively. Of the Campylobacter spp. detected, 86.1% were C. upsaliensis, 13% were C. jejuni and 0.9% were C. coli. Statistically significant sparing factors associated with the shedding of Campylobacter spp. included the feeding of a commercial dry diet and the dog's exposure to compost. Age of dog had a quadratic effect, with young dogs and senior dogs having an increased probability of shedding Campylobacter spp. compared with adult dogs. The only statistically significant risk factor for shedding C. upsaliensis was outdoor water access including lakes and ditches, while dogs >1 year old were at a lower risk than young dogs. Understanding the pet-related risk factors for Campylobacter spp. and C. upsaliensis shedding in dogs may help in the development of awareness and management strategies to potentially reduce the risk of transmitting this pathogen from dogs to humans. PMID:23802765

  5. Mecillinam in enteric fever.

    PubMed Central

    Mandal, B K; Ironside, A G; Brennand, J

    1979-01-01

    Twelve consecutive patients with enteric fever entered a trial of 14 days' treatment with mecillinam. Only three patients became afebrile within three days; four continued unimproved with fever and toxaemia for seven to nine days, when treatment was changed to chloramphenicol with good results. In one case the fever did not settle until the 13th day, and five days later the patient had a clinical relapse. Although all organisms recovered were fully sensitive to mecillinam, this drug is not an effective or consistent treatment for enteric fever. PMID:218670

  6. Outflanking the Rankings Industry

    ERIC Educational Resources Information Center

    McGuire, Patricia

    2007-01-01

    In this article, the author argues that American higher education is allowing itself to be held hostage by the rankings industry, which can lead institutions to consider actions harmful to the public interest and encourage the public's infatuation with celebrity at the expense of substance. Instead of sitting quietly by during the upcoming ratings…

  7. RANKING INDOOR AIR TOXICS

    EPA Science Inventory

    The basis of the ranking is 10 monitoring studies chosen to represent "typical" concentrations of the pollutants found indoors. The studies were conducted in the United States during the last 15 years, and mainly focused on concentrations of pollutants in homes, schools, and off...

  8. Responses to the Rankings.

    ERIC Educational Resources Information Center

    Change, 1992

    1992-01-01

    Ten higher education professionals and one college senior comment on the "U.S. News and World Report" rankings of doctoral programs in six liberal arts disciplines. The authors' response to one set of comments and the comments of an executive editor from the magazine are also included. (MSE)

  9. Diversifying customer review rankings.

    PubMed

    Krestel, Ralf; Dokoohaki, Nima

    2015-06-01

    E-commerce Web sites owe much of their popularity to consumer reviews accompanying product descriptions. On-line customers spend hours and hours going through heaps of textual reviews to decide which products to buy. At the same time, each popular product has thousands of user-generated reviews, making it impossible for a buyer to read everything. Current approaches to display reviews to users or recommend an individual review for a product are based on the recency or helpfulness of each review. In this paper, we present a framework to rank product reviews by optimizing the coverage of the ranking with respect to sentiment or aspects, or by summarizing all reviews with the top-K reviews in the ranking. To accomplish this, we make use of the assigned star rating for a product as an indicator for a review's sentiment polarity and compare bag-of-words (language model) with topic models (latent Dirichlet allocation) as a mean to represent aspects. Our evaluation on manually annotated review data from a commercial review Web site demonstrates the effectiveness of our approach, outperforming plain recency ranking by 30% and obtaining best results by combining language and topic model representations. PMID:25795511

  10. College Rankings. ERIC Digest.

    ERIC Educational Resources Information Center

    Holub, Tamara

    The popularity of college ranking surveys published by "U.S. News and World Report" and other magazines is indisputable, but the methodologies used to measure the quality of higher education institutions have come under fire by scholars and college officials. Criticisms have focused on methodological flaws, such as failure to consider differences…

  11. [Cyclic enteral nutrition].

    PubMed

    Hébuterne, X; Rampal, P

    1996-02-10

    Cyclic enteral nutrition consists in continuous infusion of nutrients with a pump over a 12 to 14 hour period at night. Different reports have demonstrated that cyclic enteral nutrition is well tolerated in malnourished ambulatory patients. The incidence of pneumonia by inhalation in this type of patients is less than 2%. Excepting patients with major amputation of the small intestine and important functional consequences, the increased infusion rate required by cyclic enteral nutrition does not diminish digestive tract absorption making the technique as effective as continuous 24-hour infusion. The main advantages of the cyclic infusion are the preservation of physiological balance between fasting and feeding, improved physical activity during the day with its beneficial effect on protein-energy metabolism, compatibility with oral nutrition during the day in nutrition reeducation programs, and the psychological impact in patients who are free to move about, further improving tolerance. Finally, cyclic enteral nutrition is adapted to enteral nutrition programs conducted in the patient's homes. PMID:8729381

  12. Top 10 plant pathogenic bacteria in molecular plant pathology.

    PubMed

    Mansfield, John; Genin, Stephane; Magori, Shimpei; Citovsky, Vitaly; Sriariyanum, Malinee; Ronald, Pamela; Dow, Max; Verdier, Valérie; Beer, Steven V; Machado, Marcos A; Toth, Ian; Salmond, George; Foster, Gary D

    2012-08-01

    Many plant bacteriologists, if not all, feel that their particular microbe should appear in any list of the most important bacterial plant pathogens. However, to our knowledge, no such list exists. The aim of this review was to survey all bacterial pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate the bacterial pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 458 votes from the international community, and allowed the construction of a Top 10 bacterial plant pathogen list. The list includes, in rank order: (1) Pseudomonas syringae pathovars; (2) Ralstonia solanacearum; (3) Agrobacterium tumefaciens; (4) Xanthomonas oryzae pv. oryzae; (5) Xanthomonas campestris pathovars; (6) Xanthomonas axonopodis pathovars; (7) Erwinia amylovora; (8) Xylella fastidiosa; (9) Dickeya (dadantii and solani); (10) Pectobacterium carotovorum (and Pectobacterium atrosepticum). Bacteria garnering honourable mentions for just missing out on the Top 10 include Clavibacter michiganensis (michiganensis and sepedonicus), Pseudomonas savastanoi and Candidatus Liberibacter asiaticus. This review article presents a short section on each bacterium in the Top 10 list and its importance, with the intention of initiating discussion and debate amongst the plant bacteriology community, as well as laying down a benchmark. It will be interesting to see, in future years, how perceptions change and which bacterial pathogens enter and leave the Top 10. PMID:22672649

  13. Ranking of refrigerants.

    PubMed

    Restrepo, Guillermo; Weckert, Monika; Brüggemann, Rainer; Gerstmann, Silke; Frank, Hartmut

    2008-04-15

    Environmental ranking of refrigerants is of need in many instances. The aim is to assess the relative environmental hazard posed by 40 refrigerants, including those used in the past, those presently used, and some proposed substitutes. Ranking is based upon ozone depletion potential, global warming potential, and atmospheric lifetime and is achieved by applying the Hasse diagram technique, a mathematical method that allows us to assess order relationships of chemicals. The refrigerants are divided into 13 classes, of which the chlorofluorocarbons, hydrofluorocarbons, hydrochlorofluorocarbons, hydrofluoroethers, and hydrocarbons contain the largest number of single substances. The dominance degree, a method for measuring order relationships among classes, is discussed and applied to the 13 refrigerant classes. The results show that some hydrofluoroethers are as problematic as the hydrofluorocarbons. Hydrocarbons and ammonia are the least problematic refrigerants with respect to the three environmental properties. PMID:18497145

  14. Communication Characteristics of Students Entering MSSD 1977-78.

    ERIC Educational Resources Information Center

    Cowan, Nancy S.; And Others

    A communication profile of each student entering the Model Secondary School for the Deaf (MSSD) is composed of rankings in five areas: expressive manual communication including signing, fingerspelling, and synchronization; speech intelligibility; articulation; speech reading, including words and sentences; and audiometric test performance…

  15. University Rankings and Social Science

    ERIC Educational Resources Information Center

    Marginson, Simon

    2014-01-01

    University rankings widely affect the behaviours of prospective students and their families, university executive leaders, academic faculty, governments and investors in higher education. Yet the social science foundations of global rankings receive little scrutiny. Rankings that simply recycle reputation without any necessary connection to real…

  16. Enteric Redmouth Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yersinia ruckeri, the causative agent of Enteric Redmouth Disease (ERM), is a disease of salmonid fish species that is endemic in areas of the world where salmonids are intensively cultured. The disease causes a chronic to acute hemorrhagic septicemia which can lead to high rates of mortality partic...

  17. Enteral approaches in malabsorption.

    PubMed

    Avitzur, Yaron; Courtney-Martin, Glenda

    2016-04-01

    Enteral autonomy and freedom from parenteral nutrition dependency is the ultimate therapeutic goal in children with intestinal failure. This can be achieved following attainment of bowel adaptation in conditions such as short bowel syndrome. Enteral nutrition is a major therapeutic cornerstone in the management of children with intestinal failure. It promotes physiological development, bowel adaptation and enhances weaning from parenteral nutrition. The optimal method of delivery, type of nutrients, timing of initiation, promotion of feeds and transition to solid food in children with short bowel syndrome are debated. Lack of high quality human data hampers evidence based conclusions and impacts daily practices in the field. Clinical approaches and therapeutic decisions are regularly influenced by expert opinion and center practices. This review summarizes the physiological principles, medical evidence and practice recommendations on enteral nutrition approaches in short bowel syndrome and provides a practical framework for daily treatment of this unique group of patients. Oral and tube feeding, bolus and continuous feeding, type of nutrients, formulas, trace elements and solid food options are reviewed. Future collaborative multicenter, high quality clinical trials are needed to support enteral nutrition approaches in intestinal failure. PMID:27086892

  18. Teaching Gateways and Bridges To Rank Broadcast Messages for Educational Networks.

    ERIC Educational Resources Information Center

    Losee, Robert M., Jr.

    Messages entering an educational information distribution network may be ranked for an ordered introduction into the network to maximize the timeliness of message arrivals over the set of users. Electronic mail, EDI documents, and broadcast news may be ranked by the users who choose to examine those messages of interest or benefit to themselves.…

  19. Low-rank coal research: Volume 1, Control technology, liquefaction, and gasification: Final report

    SciTech Connect

    Weber, G.F.; Collings, M.E.; Schelkoph, G.L.; Steadman, E.N.; Moretti, C.J.; Henke, K.R.; Rindt, J.R.; Hetland, M.D.; Knudson, C.L.; Willson, W.G.

    1987-04-01

    Volume I contains articles on SO/sub x//NO/sub x/ control, waste management, low-rank direct liquefaction, hydrogen production from low-rank coals, and advanced wastewater treatment. These articles have been entered individually into EDB and ERA. (LTN)

  20. Ranking and Sequencing Model

    Energy Science and Technology Software Center (ESTSC)

    2009-08-13

    This database application (commonly called the Supermodel) provides a repository for managing critical facility/project information, allows the user to subjectively an objectively assess key criteria , quantify project risks, develop ROM cost estimates, determine facility/project end states, ultimately performing risk-based modeling to rank facilities/project based on risk, sequencing project schedules and provides an optimized recommended sequencing/scheduling of these projects which maximize the S&M cost savings to perform closure projects which benefit all stakeholders.

  1. The Privileges of Rank

    PubMed Central

    MacLean, Alair

    2010-01-01

    This article examines the effects of peacetime cold war military service on the life course according to four potentially overlapping theories that state that military service (1) was a disruption, (2) was a positive turning point, (3) allowed veterans to accumulate advantage, and (4) was an agent of social reproduction. The article argues that the extent to which the effect of military service on veterans' lives corresponds with one or another of the preceding theories depends on historical shifts in three dimensions: conscription, conflict, and benefits. Military service during the peacetime draft era of the late 1950s had a neutral effect on the socioeconomic attainment of enlisted veterans. However, it had a positive effect on veterans who served as officers, which partly stemmed from status reproduction and selection. Yet net of pre-service and educational differences by rank, officers in this peacetime draft era were still able to accumulate advantage. PMID:20842210

  2. Risk ranking by perception

    SciTech Connect

    Osei, E.K.; Amoh, G.E.A.; Schandorf, C.

    1997-02-01

    The study of people`s perception and acceptability of risk is important in understanding the public reaction to technology and its environmental and health impact. The perception of risk depends on several factors, including early experiences, education, controllability of the risk, the type of consequence, and the type of person(s) who makes the judgment. This paper reviews some of the main factors influencing people`s perception and acceptability of risk. Knowledge about which factors influence the perception of risk may enhance the understanding of different points of view brought into risk controversies, improve risk communication, and facilitate policy making. Results from a risk ranking by perception survey Conducted in Ghana are also presented. 18 refs., 8 figs., 1 tab.

  3. Low-rank coal research

    SciTech Connect

    Weber, G. F.; Laudal, D. L.

    1989-01-01

    This work is a compilation of reports on ongoing research at the University of North Dakota. Topics include: Control Technology and Coal Preparation Research (SO{sub x}/NO{sub x} control, waste management), Advanced Research and Technology Development (turbine combustion phenomena, combustion inorganic transformation, coal/char reactivity, liquefaction reactivity of low-rank coals, gasification ash and slag characterization, fine particulate emissions), Combustion Research (fluidized bed combustion, beneficiation of low-rank coals, combustion characterization of low-rank coal fuels, diesel utilization of low-rank coals), Liquefaction Research (low-rank coal direct liquefaction), and Gasification Research (hydrogen production from low-rank coals, advanced wastewater treatment, mild gasification, color and residual COD removal from Synfuel wastewaters, Great Plains Gasification Plant, gasifier optimization).

  4. Wikipedia ranking of world universities

    NASA Astrophysics Data System (ADS)

    Lages, José; Patt, Antoine; Shepelyansky, Dima L.

    2016-03-01

    We use the directed networks between articles of 24 Wikipedia language editions for producing the wikipedia ranking of world Universities (WRWU) using PageRank, 2DRank and CheiRank algorithms. This approach allows to incorporate various cultural views on world universities using the mathematical statistical analysis independent of cultural preferences. The Wikipedia ranking of top 100 universities provides about 60% overlap with the Shanghai university ranking demonstrating the reliable features of this approach. At the same time WRWU incorporates all knowledge accumulated at 24 Wikipedia editions giving stronger highlights for historically important universities leading to a different estimation of efficiency of world countries in university education. The historical development of university ranking is analyzed during ten centuries of their history.

  5. Network tuned multiple rank aggregation and applications to gene ranking

    PubMed Central

    2015-01-01

    With the development of various high throughput technologies and analysis methods, researchers can study different aspects of a biological phenomenon simultaneously or one aspect repeatedly with different experimental techniques and analysis methods. The output from each study is a rank list of components of interest. Aggregation of the rank lists of components, such as proteins, genes and single nucleotide variants (SNV), produced by these experiments has been proven to be helpful in both filtering the noise and bringing forth a more complete understanding of the biological problems. Current available rank aggregation methods do not consider the network information that has been observed to provide vital contributions in many data integration studies. We developed network tuned rank aggregation methods incorporating network information and demonstrated its superior performance over aggregation methods without network information. The methods are tested on predicting the Gene Ontology function of yeast proteins. We validate the methods using combinations of three gene expression data sets and three protein interaction networks as well as an integrated network by combining the three networks. Results show that the aggregated rank lists are more meaningful if protein interaction network is incorporated. Among the methods compared, CGI_RRA and CGI_Endeavour, which integrate rank lists with networks using CGI [1] followed by rank aggregation using either robust rank aggregation (RRA) [2] or Endeavour [3] perform the best. Finally, we use the methods to locate target genes of transcription factors. PMID:25708095

  6. Beyond Low Rank + Sparse: Multiscale Low Rank Matrix Decomposition

    NASA Astrophysics Data System (ADS)

    Ong, Frank; Lustig, Michael

    2016-06-01

    Low rank methods allow us to capture globally correlated components within matrices. The recent low rank + sparse decomposition further enables us to extract sparse entries along with the globally correlated components. In this paper, we present a natural generalization and consider the decomposition of matrices into components of multiple scales. Such decomposition is well motivated in practice as data matrices often exhibit local correlations in multiple scales. Concretely, we propose a multi-scale low rank modeling that represents a data matrix as a sum of block-wise low rank matrices with increasing scales of block sizes. We then consider the inverse problem of decomposing the data matrix into its multi-scale low rank components and approach the problem via a convex formulation. Theoretically, we show that under an incoherence condition, the convex program recovers the multi-scale low rank components exactly. Practically, we provide guidance on selecting the regularization parameters and incorporate cycle spinning to reduce blocking artifacts. Experimentally, we show that the multi-scale low rank decomposition provides a more intuitive decomposition than conventional low rank methods and demonstrate its effectiveness in four applications, including illumination normalization for face images, motion separation for surveillance videos, multi-scale modeling of the dynamic contrast enhanced magnetic resonance imaging and collaborative filtering exploiting age information.

  7. Ranking nodes in growing networks: When PageRank fails

    NASA Astrophysics Data System (ADS)

    Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng

    2015-11-01

    PageRank is arguably the most popular ranking algorithm which is being applied in real systems ranging from information to biological and infrastructure networks. Despite its outstanding popularity and broad use in different areas of science, the relation between the algorithm’s efficacy and properties of the network on which it acts has not yet been fully understood. We study here PageRank’s performance on a network model supported by real data, and show that realistic temporal effects make PageRank fail in individuating the most valuable nodes for a broad range of model parameters. Results on real data are in qualitative agreement with our model-based findings. This failure of PageRank reveals that the static approach to information filtering is inappropriate for a broad class of growing systems, and suggest that time-dependent algorithms that are based on the temporal linking patterns of these systems are needed to better rank the nodes.

  8. Enteral nutrition - child - managing problems

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000164.htm Enteral nutrition - child - managing problems To use the sharing features ... trouble breathing, call 911. References Mcclave SA. Enteral nutrition. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  9. John Glenn Entering Friendship 7

    NASA Technical Reports Server (NTRS)

    1962-01-01

    Overall view of astronaut John Glenn, Jr., as he enters into the spacecraft Friendship 7 prior to MA-6 launch operations at Launch Complex 14. Astronaut Glenn is entering his spacecraft to begin the first American manned Earth orbital mission.

  10. Bloodborne pathogens

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000453.htm Bloodborne pathogens To use the sharing features on this page, please enable JavaScript. A pathogen is something that causes disease. Germs that can ...

  11. Obsession with Rankings Goes Global

    ERIC Educational Resources Information Center

    Labi, Aisha

    2008-01-01

    A Chinese list of the world's top universities would seem an unlikely concern for French politicians. But this year, France's legislature took aim at the annual rankings produced by Shanghai Jiao Tong University, which claims to list the 500 best universities in the world. The highest-ranked French entry, Universite Pierre et Marie Curie, comes in…

  12. University Rankings in Critical Perspective

    ERIC Educational Resources Information Center

    Pusser, Brian; Marginson, Simon

    2013-01-01

    This article addresses global postsecondary ranking systems by using critical-theoretical perspectives on power. This research suggests rankings are at once a useful lens for studying power in higher education and an important instrument for the exercise of power in service of dominant norms in global higher education. (Contains 1 table and 1…

  13. Technical Pitfalls in University Rankings

    ERIC Educational Resources Information Center

    Bougnol, Marie-Laure; Dulá, Jose H.

    2015-01-01

    Academicians, experts, and other stakeholders have contributed extensively to the literature on university rankings also known as "league tables". Often the tone is critical usually focused on the subjective aspects of the process; e.g., the list of the universities' attributes used in the rankings, their respective weights, and the size…

  14. University Ranking as Social Exclusion

    ERIC Educational Resources Information Center

    Amsler, Sarah S.; Bolsmann, Chris

    2012-01-01

    In this article we explore the dual role of global university rankings in the creation of a new, knowledge-identified, transnational capitalist class and in facilitating new forms of social exclusion. We examine how and why the practice of ranking universities has become widely defined by national and international organisations as an important…

  15. Entering the Anthropocene

    NASA Astrophysics Data System (ADS)

    Vince, Gaia

    2016-04-01

    There is growing evidence that we are now entering a new geological age defined by human influence on the planet, the Anthropocene. Millions of years from now, a stripe in the accumulated layers of rock on Earth's surface will reveal our human fingerprint just as we can see evidence of dinosaurs in rocks of the Jurassic, or the explosion of life that marks the Cambrian. There is now no part of the planet untouched by human influence. The realisation that we wield such planetary power requires a quite extraordinary shift in perception, fundamentally toppling the scientific, cultural and religious philosophies that define our place in the world. This session explores these issues and examines our new relationship with nature now that we so strongly influence the biosphere. And this session will look at what the impacts of our planetary changes mean for us, and how we might deal with the consequences of the Anthropocene we have created.

  16. Novel method to identify probiotic isolates against enteric foodborne pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter is the leading cause of foodborne illness worldwide, primarily caused by consumption of contaminated poultry products. One potential strategy to reduce Campylobacter colonization in poultry is by the use of oral probiotics, but this produces variable results, possibly due to destructio...

  17. Universal scaling in sports ranking

    NASA Astrophysics Data System (ADS)

    Deng, Weibing; Li, Wei; Cai, Xu; Bulou, Alain; Wang, Qiuping A.

    2012-09-01

    Ranking is a ubiquitous phenomenon in human society. On the web pages of Forbes, one may find all kinds of rankings, such as the world's most powerful people, the world's richest people, the highest-earning tennis players, and so on and so forth. Herewith, we study a specific kind—sports ranking systems in which players' scores and/or prize money are accrued based on their performances in different matches. By investigating 40 data samples which span 12 different sports, we find that the distributions of scores and/or prize money follow universal power laws, with exponents nearly identical for most sports. In order to understand the origin of this universal scaling we focus on the tennis ranking systems. By checking the data we find that, for any pair of players, the probability that the higher-ranked player tops the lower-ranked opponent is proportional to the rank difference between the pair. Such a dependence can be well fitted to a sigmoidal function. By using this feature, we propose a simple toy model which can simulate the competition of players in different matches. The simulations yield results consistent with the empirical findings. Extensive simulation studies indicate that the model is quite robust with respect to the modifications of some parameters.

  18. Yokenella regensburgei infection in India mimicking enteric fever.

    PubMed

    Jain, Sarika; Gaind, Rajni; Gupta, Kunj Bihari; Dawar, Reetika; Kumar, Deepak; Paul, Premila; Sardana, Raman; Deb, Manorama

    2013-06-01

    Yokenella regensburgei is an opportunistic human pathogen of the Enterobacteriaceae family rarely reported to cause human infections. Here, we present a case report of Y. regensburgei bacteraemia from India clinically resembling enteric fever in an apparently immunocompetent paediatric patient. PMID:23518660

  19. TripleRank: Ranking Semantic Web Data by Tensor Decomposition

    NASA Astrophysics Data System (ADS)

    Franz, Thomas; Schultz, Antje; Sizov, Sergej; Staab, Steffen

    The Semantic Web fosters novel applications targeting a more efficient and satisfying exploitation of the data available on the web, e.g. faceted browsing of linked open data. Large amounts and high diversity of knowledge in the Semantic Web pose the challenging question of appropriate relevance ranking for producing fine-grained and rich descriptions of the available data, e.g. to guide the user along most promising knowledge aspects. Existing methods for graph-based authority ranking lack support for fine-grained latent coherence between resources and predicates (i.e. support for link semantics in the linked data model). In this paper, we present TripleRank, a novel approach for faceted authority ranking in the context of RDF knowledge bases. TripleRank captures the additional latent semantics of Semantic Web data by means of statistical methods in order to produce richer descriptions of the available data. We model the Semantic Web by a 3-dimensional tensor that enables the seamless representation of arbitrary semantic links. For the analysis of that model, we apply the PARAFAC decomposition, which can be seen as a multi-modal counterpart to Web authority ranking with HITS. The result are groupings of resources and predicates that characterize their authority and navigational (hub) properties with respect to identified topics. We have applied TripleRank to multiple data sets from the linked open data community and gathered encouraging feedback in a user evaluation where TripleRank results have been exploited in a faceted browsing scenario.

  20. Microscopic enteritis: Bucharest consensus.

    PubMed

    Rostami, Kamran; Aldulaimi, David; Holmes, Geoffrey; Johnson, Matt W; Robert, Marie; Srivastava, Amitabh; Fléjou, Jean-François; Sanders, David S; Volta, Umberto; Derakhshan, Mohammad H; Going, James J; Becheanu, Gabriel; Catassi, Carlo; Danciu, Mihai; Materacki, Luke; Ghafarzadegan, Kamran; Ishaq, Sauid; Rostami-Nejad, Mohammad; Peña, A Salvador; Bassotti, Gabrio; Marsh, Michael N; Villanacci, Vincenzo

    2015-03-01

    Microscopic enteritis (ME) is an inflammatory condition of the small bowel that leads to gastrointestinal symptoms, nutrient and micronutrient deficiency. It is characterised by microscopic or sub-microscopic abnormalities such as microvillus changes and enterocytic alterations in the absence of definite macroscopic changes using standard modern endoscopy. This work recognises a need to characterize disorders with microscopic and submicroscopic features, currently regarded as functional or non-specific entities, to obtain further understanding of their clinical relevance. The consensus working party reviewed statements about the aetiology, diagnosis and symptoms associated with ME and proposes an algorithm for its investigation and treatment. Following the 5(th) International Course in Digestive Pathology in Bucharest in November 2012, an international group of 21 interested pathologists and gastroenterologists formed a working party with a view to formulating a consensus statement on ME. A five-step agreement scale (from strong agreement to strong disagreement) was used to score 21 statements, independently. There was strong agreement on all statements about ME histology (95%-100%). Statements concerning diagnosis achieved 85% to 100% agreement. A statement on the management of ME elicited agreement from the lowest rate (60%) up to 100%. The remaining two categories showed general agreement between experts on clinical presentation (75%-95%) and pathogenesis (80%-90%) of ME. There was strong agreement on the histological definition of ME. Weaker agreement on management indicates a need for further investigations, better definitions and clinical trials to produce quality guidelines for management. This ME consensus is a step toward greater recognition of a significant entity affecting symptomatic patients previously labelled as non-specific or functional enteropathy. PMID:25759526

  1. Microscopic enteritis: Bucharest consensus

    PubMed Central

    Rostami, Kamran; Aldulaimi, David; Holmes, Geoffrey; Johnson, Matt W; Robert, Marie; Srivastava, Amitabh; Fléjou, Jean-François; Sanders, David S; Volta, Umberto; Derakhshan, Mohammad H; Going, James J; Becheanu, Gabriel; Catassi, Carlo; Danciu, Mihai; Materacki, Luke; Ghafarzadegan, Kamran; Ishaq, Sauid; Rostami-Nejad, Mohammad; Peña, A Salvador; Bassotti, Gabrio; Marsh, Michael N; Villanacci, Vincenzo

    2015-01-01

    Microscopic enteritis (ME) is an inflammatory condition of the small bowel that leads to gastrointestinal symptoms, nutrient and micronutrient deficiency. It is characterised by microscopic or sub-microscopic abnormalities such as microvillus changes and enterocytic alterations in the absence of definite macroscopic changes using standard modern endoscopy. This work recognises a need to characterize disorders with microscopic and submicroscopic features, currently regarded as functional or non-specific entities, to obtain further understanding of their clinical relevance. The consensus working party reviewed statements about the aetiology, diagnosis and symptoms associated with ME and proposes an algorithm for its investigation and treatment. Following the 5th International Course in Digestive Pathology in Bucharest in November 2012, an international group of 21 interested pathologists and gastroenterologists formed a working party with a view to formulating a consensus statement on ME. A five-step agreement scale (from strong agreement to strong disagreement) was used to score 21 statements, independently. There was strong agreement on all statements about ME histology (95%-100%). Statements concerning diagnosis achieved 85% to 100% agreement. A statement on the management of ME elicited agreement from the lowest rate (60%) up to 100%. The remaining two categories showed general agreement between experts on clinical presentation (75%-95%) and pathogenesis (80%-90%) of ME. There was strong agreement on the histological definition of ME. Weaker agreement on management indicates a need for further investigations, better definitions and clinical trials to produce quality guidelines for management. This ME consensus is a step toward greater recognition of a significant entity affecting symptomatic patients previously labelled as non-specific or functional enteropathy. PMID:25759526

  2. Influence Analysis of Ranking Data.

    ERIC Educational Resources Information Center

    Poon, Wai-Yin; Chan, Wai

    2002-01-01

    Developed diagnostic measures to identify observations in Thurstonian models for ranking data that unduly influence parameter estimates obtained by the partition maximum likelihood approach of W. Chan and P. Bender (1998). (SLD)

  3. RANK and RANK ligand expression in primary human osteosarcoma.

    PubMed

    Branstetter, Daniel; Rohrbach, Kathy; Huang, Li-Ya; Soriano, Rosalia; Tometsko, Mark; Blake, Michelle; Jacob, Allison P; Dougall, William C

    2015-09-01

    Receptor activator of nuclear factor kappa-B ligand (RANKL) is an essential mediator of osteoclast formation, function and survival. In patients with solid tumor metastasis to the bone, targeting the bone microenvironment by inhibition of RANKL using denosumab, a fully human monoclonal antibody (mAb) specific to RANKL, has been demonstrated to prevent tumor-induced osteolysis and subsequent skeletal complications. Recently, a prominent functional role for the RANKL pathway has emerged in the primary bone tumor giant cell tumor of bone (GCTB). Expression of both RANKL and RANK is extremely high in GCTB tumors and denosumab treatment was associated with tumor regression and reduced tumor-associated bone lysis in GCTB patients. In order to address the potential role of the RANKL pathway in another primary bone tumor, this study assessed human RANKL and RANK expression in human primary osteosarcoma (OS) using specific mAbs, validated and optimized for immunohistochemistry (IHC) or flow cytometry. Our results demonstrate RANKL expression was observed in the tumor element in 68% of human OS using IHC. However, the staining intensity was relatively low and only 37% (29/79) of samples exhibited≥10% RANKL positive tumor cells. RANK expression was not observed in OS tumor cells. In contrast, RANK expression was clearly observed in other cells within OS samples, including the myeloid osteoclast precursor compartment, osteoclasts and in giant osteoclast cells. The intensity and frequency of RANKL and RANK staining in OS samples were substantially less than that observed in GCTB samples. The observation that RANKL is expressed in OS cells themselves suggests that these tumors may mediate an osteoclastic response, and anti-RANKL therapy may potentially be protective against bone pathologies in OS. However, the absence of RANK expression in primary human OS cells suggests that any autocrine RANKL/RANK signaling in human OS tumor cells is not operative, and anti-RANKL therapy

  4. TRANSMISSION OF ENTERIC DISEASE ASSOCIATED WITH WASTEWATER IRRIGATION: A PROSPECTIVE EPIDEMIOLOGICAL STUDY

    EPA Science Inventory

    We conducted a prospective epidemiological study of possible enteric disease transmission by aerosolized pathogens from sprinkler irrigation of partially treated wastewater in 20 kibbutzim (colllective agricultural settlements) in Isreal between March 1981 and February 1982. Medi...

  5. Ranking nodes in growing networks: When PageRank fails

    PubMed Central

    Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng

    2015-01-01

    PageRank is arguably the most popular ranking algorithm which is being applied in real systems ranging from information to biological and infrastructure networks. Despite its outstanding popularity and broad use in different areas of science, the relation between the algorithm’s efficacy and properties of the network on which it acts has not yet been fully understood. We study here PageRank’s performance on a network model supported by real data, and show that realistic temporal effects make PageRank fail in individuating the most valuable nodes for a broad range of model parameters. Results on real data are in qualitative agreement with our model-based findings. This failure of PageRank reveals that the static approach to information filtering is inappropriate for a broad class of growing systems, and suggest that time-dependent algorithms that are based on the temporal linking patterns of these systems are needed to better rank the nodes. PMID:26553630

  6. Ranking structures and rank-rank correlations of countries: The FIFA and UEFA cases

    NASA Astrophysics Data System (ADS)

    Ausloos, Marcel; Cloots, Rudi; Gadomski, Adam; Vitanov, Nikolay K.

    2014-04-01

    Ranking of agents competing with each other in complex systems may lead to paradoxes according to the pre-chosen different measures. A discussion is presented on such rank-rank, similar or not, correlations based on the case of European countries ranked by UEFA and FIFA from different soccer competitions. The first question to be answered is whether an empirical and simple law is obtained for such (self-) organizations of complex sociological systems with such different measuring schemes. It is found that the power law form is not the best description contrary to many modern expectations. The stretched exponential is much more adequate. Moreover, it is found that the measuring rules lead to some inner structures in both cases.

  7. [Basic and clinical studies of fleroxacin on infectious enteritis. Research Group of AM-833 on infectious enteritis].

    PubMed

    Sagara, H; Tomizawa, I; Takizawa, Y; Nitta, Y; Tsunoda, T; Yamaguchi, T; Masuda, G; Negishi, M; Ajisawa, A; Murata, M

    1994-11-01

    A clinical study was conducted on fleroxacin (FLRX) in 143 patients and carriers with infectious enteritis (shigellosis, Salmonella enteritis, Campylobacter enteritis, pathogenic Escherichia coli enteritis, Vibrio parahaemolyticus enteritis, cholera, multiple bacterial infections, pathogen-negative enteritis). Furthermore, its antibacterial activity against clinical isolates, fecal concentration and effect on fecal microflora were conducted. FLRX was administered orally in doses of 200 mg once a day (200 mg group) or 300 mg once a day (300 mg group) for 3 days to cholera, for 7 days to Salmonella enteritis and for 5 days to the other infectious enteritis. The clinical efficacy rates were 100% in both the 200 mg and 300 mg groups. The bacteriological efficacy rates were 100% against Shigella spp., Salmonella spp., pathogenic E. coli, V. parahaemolyticus and V. cholerae O1, and 63.6% against Campylobacter spp. in the 200 mg group. The rates of the 300 mg group were 93.3% against Shigella spp., and 100% against Campylobacter spp. and pathogenic E. coli. As adverse effects, skin rash was observed in 1 case each in both groups (1.1%, 2.1%). Abnormal laboratory findings consisted of 1 case of increased eosinophils and 1 case of elevated GOT and GPT levels in the 200 mg group (2.8%), and 1 case of elevated GPT in the 300 mg group (2.9%). The clinical usefulness rates were 92.9% and 93.3% in the 200 mg and 300 mg groups, respectively. Antibacterial activity was somewhat inferior to that fo ciprofloxacin and equal to or better than that of norfloxacin, demonstrating MIC90 values against Shigella spp., Salmonella spp., pathogenic E. coli, V. parahaemolyticus and Campylobacter spp. of 0.1, 0.2, 0.1, 0.2 and 0.78 micrograms/ml, respectively. Peak fecal concentrations of the drug were 49.0 micrograms/g and 274.4 micrograms/g in the 200 mg group, and 43.3 micrograms/g and below the detection limit (5.0 micrograms/g) in the 300 mg group. With respect to fecal microflora (4 cases

  8. Common themes in microbial pathogenicity.

    PubMed Central

    Finlay, B B; Falkow, S

    1989-01-01

    A bacterial pathogen is a highly adapted microorganism which has the capacity to cause disease. The mechanisms used by pathogenic bacteria to cause infection and disease usually include an interactive group of virulence determinants, sometimes coregulated, which are suited for the interaction of a particular microorganism with a specific host. Because pathogens must overcome similar host barriers, common themes in microbial pathogenesis have evolved. However, these mechanisms are diverse between species and not necessarily conserved; instead, convergent evolution has developed several different mechanisms to overcome host barriers. The success of a bacterial pathogen can be measured by the degree with which it replicates after entering the host and reaching its specific niche. Successful microbial infection reflects persistence within a host and avoidance or neutralization of the specific and nonspecific defense mechanisms of the host. The degree of success of a pathogen is dependent upon the status of the host. As pathogens pass through a host, they are exposed to new environments. Highly adapted pathogenic organisms have developed biochemical sensors exquisitely designed to measure and respond to such environmental stimuli and accordingly to regulate a cascade of virulence determinants essential for life within the host. The pathogenic state is the product of dynamic selective pressures on microbial populations. PMID:2569162

  9. Ranking species in mutualistic networks.

    PubMed

    Domínguez-García, Virginia; Muñoz, Miguel A

    2015-01-01

    Understanding the architectural subtleties of ecological networks, believed to confer them enhanced stability and robustness, is a subject of outmost relevance. Mutualistic interactions have been profusely studied and their corresponding bipartite networks, such as plant-pollinator networks, have been reported to exhibit a characteristic "nested" structure. Assessing the importance of any given species in mutualistic networks is a key task when evaluating extinction risks and possible cascade effects. Inspired in a recently introduced algorithm--similar in spirit to Google's PageRank but with a built-in non-linearity--here we propose a method which--by exploiting their nested architecture--allows us to derive a sound ranking of species importance in mutualistic networks. This method clearly outperforms other existing ranking schemes and can become very useful for ecosystem management and biodiversity preservation, where decisions on what aspects of ecosystems to explicitly protect need to be made. PMID:25640575

  10. Ranking species in mutualistic networks

    PubMed Central

    Domínguez-García, Virginia; Muñoz, Miguel A.

    2015-01-01

    Understanding the architectural subtleties of ecological networks, believed to confer them enhanced stability and robustness, is a subject of outmost relevance. Mutualistic interactions have been profusely studied and their corresponding bipartite networks, such as plant-pollinator networks, have been reported to exhibit a characteristic “nested” structure. Assessing the importance of any given species in mutualistic networks is a key task when evaluating extinction risks and possible cascade effects. Inspired in a recently introduced algorithm –similar in spirit to Google's PageRank but with a built-in non-linearity– here we propose a method which –by exploiting their nested architecture– allows us to derive a sound ranking of species importance in mutualistic networks. This method clearly outperforms other existing ranking schemes and can become very useful for ecosystem management and biodiversity preservation, where decisions on what aspects of ecosystems to explicitly protect need to be made. PMID:25640575

  11. Ranking species in mutualistic networks

    NASA Astrophysics Data System (ADS)

    Domínguez-García, Virginia; Muñoz, Miguel A.

    2015-02-01

    Understanding the architectural subtleties of ecological networks, believed to confer them enhanced stability and robustness, is a subject of outmost relevance. Mutualistic interactions have been profusely studied and their corresponding bipartite networks, such as plant-pollinator networks, have been reported to exhibit a characteristic ``nested'' structure. Assessing the importance of any given species in mutualistic networks is a key task when evaluating extinction risks and possible cascade effects. Inspired in a recently introduced algorithm -similar in spirit to Google's PageRank but with a built-in non-linearity- here we propose a method which -by exploiting their nested architecture- allows us to derive a sound ranking of species importance in mutualistic networks. This method clearly outperforms other existing ranking schemes and can become very useful for ecosystem management and biodiversity preservation, where decisions on what aspects of ecosystems to explicitly protect need to be made.

  12. Retention of Enteric Viruses by the Hemocytes of the Eastern Oyster (Crassostrea virginica)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shellfish are an important vector for transmission of enteric pathogens. Interventions, such as depuration, do not adequately clear enteric viruses, while fecal bacteria levels are significantly reduced. Why viruses are retained in the bivalve flesh is not well understood. We hypothesize that phagoc...

  13. Rank in Class and College Admission

    ERIC Educational Resources Information Center

    Walker, Karen

    2010-01-01

    Traditionally class rankings have been used by high schools to determine valedictorians and salutatorians. These rankings have also been used by colleges to make admission decisions and for awarding scholarships. While there is no direct link between college rank and college admission, there is evidence that not using class rank can reduce stress…

  14. The Globalization of College and University Rankings

    ERIC Educational Resources Information Center

    Altbach, Philip G.

    2012-01-01

    In the era of globalization, accountability, and benchmarking, university rankings have achieved a kind of iconic status. The major ones--the Academic Ranking of World Universities (ARWU, or the "Shanghai rankings"), the QS (Quacquarelli Symonds Limited) World University Rankings, and the "Times Higher Education" World University Rankings…

  15. Time evolution of Wikipedia network ranking

    NASA Astrophysics Data System (ADS)

    Eom, Young-Ho; Frahm, Klaus M.; Benczúr, András; Shepelyansky, Dima L.

    2013-12-01

    We study the time evolution of ranking and spectral properties of the Google matrix of English Wikipedia hyperlink network during years 2003-2011. The statistical properties of ranking of Wikipedia articles via PageRank and CheiRank probabilities, as well as the matrix spectrum, are shown to be stabilized for 2007-2011. A special emphasis is done on ranking of Wikipedia personalities and universities. We show that PageRank selection is dominated by politicians while 2DRank, which combines PageRank and CheiRank, gives more accent on personalities of arts. The Wikipedia PageRank of universities recovers 80% of top universities of Shanghai ranking during the considered time period.

  16. Pathogenic agents in freshwater resources

    NASA Astrophysics Data System (ADS)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  17. Development of methodology to prioritise wildlife pathogens for surveillance.

    PubMed

    McKenzie, Joanna; Simpson, Helen; Langstaff, Ian

    2007-09-14

    We developed and evaluated a methodology to prioritise pathogens for a wildlife disease surveillance strategy in New Zealand. The methodology, termed 'rapid risk analysis' was based on the import risk analysis framework recommended by the Office Internationale des Epizooties (OIE), and involved: hazard identification, risk estimation, and ranking of 48 exotic and 34 endemic wildlife pathogens. The risk assessment was more rapid than a full quantitative assessment through the use of a semi-quantitative approach to score pathogens for probability of entry to NZ (release assessment), likelihood of spread (exposure assessment) and consequences in free-living wildlife, captive wildlife, humans, livestock and companion animals. Risk was estimated by multiplying the scores for the probability of entry to New Zealand by the likelihood of spread by the consequences for free-living wildlife, humans and livestock. The rapid risk analysis methodology produced scores that were sufficiently differentiated between pathogens to be useful for ranking them on the basis of risk. Ranking pathogens on the basis of the risk estimate for each population sector provided an opportunity to identify the priorities within each sector alone thus avoiding value-laden comparisons between sectors. Ranking pathogens across all three population sectors by summing the risk estimate for each sector provided a comparison of total risk which may be useful for resource allocation decisions at national level. Ranking pathogens within each wildlife taxonomic group using the total risk estimate was most useful for developing specific surveillance strategies for each group. PMID:17482697

  18. Genetically disparate Fayoumi chicken lines show different response to avian Necrotic Enteritis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Necrotic enteritis (NE) has reemerged as a significant problem as a result of growing restrictions of antibiotics in agricultural animal production and increasing concerns over antibiotic resistance in human pathogens. To enhance our understanding of host-pathogen immunobiology in NE, transcriptomi...

  19. Querying and Ranking XML Documents.

    ERIC Educational Resources Information Center

    Schlieder, Torsten; Meuss, Holger

    2002-01-01

    Discussion of XML, information retrieval, precision, and recall focuses on a retrieval technique that adopts the similarity measure of the vector space model, incorporates the document structure, and supports structured queries. Topics include a query model based on tree matching; structured queries and term-based ranking; and term frequency and…

  20. Low-Rank Preserving Projections.

    PubMed

    Lu, Yuwu; Lai, Zhihui; Xu, Yong; Li, Xuelong; Zhang, David; Yuan, Chun

    2016-08-01

    As one of the most popular dimensionality reduction techniques, locality preserving projections (LPP) has been widely used in computer vision and pattern recognition. However, in practical applications, data is always corrupted by noises. For the corrupted data, samples from the same class may not be distributed in the nearest area, thus LPP may lose its effectiveness. In this paper, it is assumed that data is grossly corrupted and the noise matrix is sparse. Based on these assumptions, we propose a novel dimensionality reduction method, named low-rank preserving projections (LRPP) for image classification. LRPP learns a low-rank weight matrix by projecting the data on a low-dimensional subspace. We use the L21 norm as a sparse constraint on the noise matrix and the nuclear norm as a low-rank constraint on the weight matrix. LRPP keeps the global structure of the data during the dimensionality reduction procedure and the learned low rank weight matrix can reduce the disturbance of noises in the data. LRPP can learn a robust subspace from the corrupted data. To verify the performance of LRPP in image dimensionality reduction and classification, we compare LRPP with the state-of-the-art dimensionality reduction methods. The experimental results show the effectiveness and the feasibility of the proposed method with encouraging results. PMID:26277014

  1. Let Us Rank Journalism Programs

    ERIC Educational Resources Information Center

    Weber, Joseph

    2014-01-01

    Unlike law, business, and medical schools, as well as universities in general, journalism schools and journalism programs have rarely been ranked. Publishers such as "U.S. News & World Report," "Forbes," "Bloomberg Businessweek," and "Washington Monthly" do not pay them much mind. What is the best…

  2. On Rank Driven Dynamical Systems

    NASA Astrophysics Data System (ADS)

    Veerman, J. J. P.; Prieto, F. J.

    2014-08-01

    We investigate a class of models related to the Bak-Sneppen (BS) model, initially proposed to study evolution. The BS model is extremely simple and yet captures some forms of "complex behavior" such as self-organized criticality that is often observed in physical and biological systems. In this model, random fitnesses in are associated to agents located at the vertices of a graph . Their fitnesses are ranked from worst (0) to best (1). At every time-step the agent with the worst fitness and some others with a priori given rank probabilities are replaced by new agents with random fitnesses. We consider two cases: The exogenous case where the new fitnesses are taken from an a priori fixed distribution, and the endogenous case where the new fitnesses are taken from the current distribution as it evolves. We approximate the dynamics by making a simplifying independence assumption. We use Order Statistics and Dynamical Systems to define a rank-driven dynamical system that approximates the evolution of the distribution of the fitnesses in these rank-driven models, as well as in the BS model. For this simplified model we can find the limiting marginal distribution as a function of the initial conditions. Agreement with experimental results of the BS model is excellent.

  3. RELATIVE POTENCY RANKING FOR CHLOROPHENOLS

    EPA Science Inventory

    Recently the National Center for Environmental Assessment-Cincinnati completed a feasibility study for developing a toxicity related relative potency ranking scheme for chlorophenols. In this study it was concluded that a large data base exists pertaining to the relative toxicity...

  4. Detection of Human Enteric Viruses in Freshwater from European Countries.

    PubMed

    D'Ugo, Emilio; Marcheggiani, Stefania; Fioramonti, Ilaria; Giuseppetti, Roberto; Spurio, Roberto; Helmi, Karim; Guillebault, Delphine; Medlin, Linda K; Simeonovski, Ivan; Boots, Bas; Breitenbach, Ulrich; Koker, Latife; Albay, Meric; Mancini, Laura

    2016-09-01

    The transmission of water-borne pathogens typically occurs by a faecal-oral route, through inhalation of aerosols, or by direct or indirect contact with contaminated water. Previous molecular-based studies have identified viral particles of zoonotic and human nature in surface waters. Contaminated water can lead to human health issues, and the development of rapid methods for the detection of pathogenic microorganisms is a valuable tool for the prevention of their spread. The aims of this work were to determine the presence and identity of representative human pathogenic enteric viruses in water samples from six European countries by quantitative polymerase chain reaction (q-PCR) and to develop two quantitative PCR methods for Adenovirus 41 and Mammalian Orthoreoviruses. A 2-year survey showed that Norovirus, Mammalian Orthoreovirus and Adenoviruses were the most frequently identified enteric viruses in the sampled surface waters. Although it was not possible to establish viability and infectivity of the viruses considered, the detectable presence of pathogenic viruses may represent a potential risk for human health. The methodology developed may aid in rapid detection of these pathogens for monitoring quality of surface waters. PMID:27117764

  5. Necrotic enteritis predisposing factors in broiler chickens.

    PubMed

    Moore, Robert J

    2016-06-01

    Necrotic enteritis in chickens develops as a result of infection with pathogenic strains of Clostridium perfringens and the presence of predisposing factors. Predisposing factors include elements that directly change the physical properties of the gut, either damaging the epithelial surface, inducing mucus production, or changing gut transit times; factors that disrupt the gut microbiota; and factors that alter the immune status of birds. In the past research into necrotic enteritis predisposing factors was directed by the simple hypothesis that low-level colonization of C. perfringens commonly occurred within the gut of healthy chickens and the predisposing factors lead to a proliferation of those bacteria to produce disease. More recently, with an increasing understanding of the major virulence factors of C. perfringens and the application of molecular techniques to define different clades of C. perfringens strains, it has become clear that the C. perfringens isolates commonly found in healthy chickens are generally not strains that have the potential to cause disease. Therefore, we need to re-evaluate hypotheses regarding the development of disease, the origin of disease causing isolates of C. perfringens, and the importance of interactions with other C. perfringens strains and with predisposing factors. Many predisposing factors that affect the physical and immunological characteristics of the gastrointestinal tract may also change the resident microbiota. Research directed towards defining the relative importance of each of these different actions of predisposing factors will improve the understanding of disease pathogenesis and may allow refinement of experiment disease models. PMID:26926926

  6. Turkey industry strategies for control of respiratory and enteric diseases.

    PubMed

    Poss, P E

    1998-08-01

    Current strategies to control respiratory and enteric diseases of turkeys involve sanitation and biosecurity practices to prevent the introduction of infectious agents. In addition, proper husbandry and management practice reduce stress and help maintain a competent immune system. Industry-wide monitoring programs are used in conjunction with isolation, depopulation, and orderly marketing to eliminate pathogens that cause serious economic loss. Vaccines are available and utilized against some pathogens. Effective drug treatment is available and used for some diseases but is most commonly used to control secondary disease losses when treatment is not available for the primary disease. PMID:9706086

  7. Concerns of Entering Dental Students.

    ERIC Educational Resources Information Center

    Sachs, Robert H.; And Others

    1981-01-01

    First-year dental students from three schools were surveyed to assess their concern about psychosocial, academic, time, isolation, and money issues. Similarity in ranking of concerns, and differences in intensity of concern are examined for implications for research in stress management. (MSE)

  8. The enter-educate approach.

    PubMed

    Piotrow, P T; Coleman, P L

    1992-03-01

    This article describes how the Population Communication Services (PCS) has seized on the "enter-educate" approach, the blending of popular entertainment with social messages, to change reproductive health behavior. The enter-educate approach spreads its message through songs, soap operas, variety shows, and other types of popular entertainment mediums. Because they entertain, enter-educate projects can capture the attention of an audience -- such as young people -- who would otherwise scorn social messages. And the use of population mediums makes it possible to reach a variety of audiences. Funded by USAID, PCS began its first enter-educate project in response to the increasing number of teenage pregnancies in Latin America. PCS developed 2 songs and videos, which featured popular teenage singers to serve as role models, to urge abstinence. The songs became instant hits. Since then, PCS has mounted more then 80 major projects in some 40 countries. Highlights of programs range from a successful multi-media family planning campaign in Turkey to humorous television ads in Brazil promoting vasectomy. Recently, PCS initiated projects to teach AIDS awareness. At the core of the enter-educate approach is the social learning theory which holds that much behavior is learned through the observation of role-models. Health professionals work alongside entertainers to produce works that have audience appeal and factual social messages. The enter-educate approach works because it is popular, pervasive, personal, persuasive, and profitable. PCS has found that enter-educate programs pay for themselves through cost sharing and cost recovery. PMID:12284960

  9. The top 10 oomycete pathogens in molecular plant pathology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oomycetes form a deep lineage of eukaryotic organisms that includes a large number of plant pathogens that threaten natural and managed ecosystems. We undertook a survey to query the community for their ranking of plant pathogenic oomycete taxa based on scientific and economic importance. In total, ...

  10. Field survey of enteric viruses in solid waste landfill leachates.

    PubMed Central

    Sobsey, M D

    1978-01-01

    Because municipal solid waste may contain fecal material from a variety of sources, there is concern that the leachate discharged from some solid waste landfills may contain enteric pathogens, including enteric viruses. In this study, 22 leachate samples from 21 different landfills in the United States and Canada were examined for enteric viruses. The sites represented a broad range of conditions for solid waste landfills and the leachate samples ranged from 10.3 to 18 liters in volume. Enteric viruses were found in only one of the 22 leachate samples examined. Two viruses, identified as poliovirus types 1 and 3, were found in an 11.8 liter sample obtained from a site where solid waste landfill practice was deficient. The low levels of enteric viruses detected in field samples of raw leachate and the opportunities for further reductions in the virus concentration of leachates by such processes as thermal inactivation, removal by soil and dilution in ground and surface waters, suggest that leachates from properly operated solid waste landfills do not constitute an environmental or public health hazard due to enteric viruses. PMID:28677

  11. Enteric viruses of chickens and turkeys

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although enteric disease in commercial poultry operations is common, and often unofficially reported and discussed by field veterinarians as “non-specific enteric disease”, three recognized enteric syndromes do exist in poultry: poult enteritis complex (PEC) and poult enteritis mortality syndrome (P...

  12. Comparative genomic analysis of bacteriophages specific to the channel catfish pathogen Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: The bacterial pathogen Edwardsiella ictaluri is a primary cause of mortality in channel catfish raised commercially in aquaculture farms. Additional treatment and diagnostic regimes are needed for this enteric pathogen, motivating the discovery and characterization of bacteriophages spe...

  13. SibRank: Signed bipartite network analysis for neighbor-based collaborative ranking

    NASA Astrophysics Data System (ADS)

    Shams, Bita; Haratizadeh, Saman

    2016-09-01

    Collaborative ranking is an emerging field of recommender systems that utilizes users' preference data rather than rating values. Unfortunately, neighbor-based collaborative ranking has gained little attention despite its more flexibility and justifiability. This paper proposes a novel framework, called SibRank that seeks to improve the state of the art neighbor-based collaborative ranking methods. SibRank represents users' preferences as a signed bipartite network, and finds similar users, through a novel personalized ranking algorithm in signed networks.

  14. Pathogen intelligence

    PubMed Central

    Steinert, Michael

    2014-01-01

    Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behavior, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behavior, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies. PMID:24551600

  15. Low-rank coal research: Volume 2, Advanced research and technology development: Final report

    SciTech Connect

    Mann, M.D.; Swanson, M.L.; Benson, S.A.; Radonovich, L.; Steadman, E.N.; Sweeny, P.G.; McCollor, D.P.; Kleesattel, D.; Grow, D.; Falcone, S.K.

    1987-04-01

    Volume II contains articles on advanced combustion phenomena, combustion inorganic transformation; coal/char reactivity; liquefaction reactivity of low-rank coals, gasification ash and slag characterization, and fine particulate emissions. These articles have been entered individually into EDB and ERA. (LTN)

  16. Enteritis

    MedlinePlus

    ... be caused by: An autoimmune condition such as Crohn's disease Certain drugs, including ibuprofen, naproxen sodium, and cocaine ... may need to take antibiotics. People who have Crohn's disease will often need to take anti-inflammatory medicines. ...

  17. Bioengineered probiotics, a strategic approach to control enteric infections

    PubMed Central

    Amalaradjou, Mary Anne Roshni; Bhunia, Arun K

    2013-01-01

    Enteric infections account for high morbidity and mortality and are considered to be the fifth leading cause of death at all ages worldwide. Seventy percent of all enteric infections are foodborne. Thus significant efforts have been directed toward the detection, control and prevention of foodborne diseases. Many antimicrobials including antibiotics have been used for their control and prevention. However, probiotics offer a potential alternative intervention strategy owing to their general health beneficial properties and inhibitory effects against foodborne pathogens. Often, antimicrobial probiotic action is non-specific and non-discriminatory or may be ineffective. In such cases, bioengineered probiotics expressing foreign gene products to achieve specific function is highly desirable. In this review we summarize the strategic development of recombinant bioengineered probiotics to control enteric infections, and to examine how scientific advancements in the human microbiome and their immunomodulatory effects help develop such novel and safe bioengineered probiotics. PMID:23327986

  18. Twisted Yangians of small rank

    NASA Astrophysics Data System (ADS)

    Guay, Nicolas; Regelskis, Vidas; Wendlandt, Curtis

    2016-04-01

    We study quantized enveloping algebras called twisted Yangians associated with the symmetric pairs of types CI, BDI, and DIII (in Cartan's classification) when the rank is small. We establish isomorphisms between these twisted Yangians and the well known Olshanskii's twisted Yangians of types AI and AII, and also with the Molev-Ragoucy reflection algebras associated with symmetric pairs of type AIII. We also construct isomorphisms with twisted Yangians in Drinfeld's original presentation.

  19. What Prevents Nurses from Entering Faculty Positions Early in Their Professional Career: A Qualitative Study

    ERIC Educational Resources Information Center

    Moreland, Jack E.

    2011-01-01

    There is a nursing faculty shortage in the United States today and projections are that over the next decade nurses will retire at a rate faster than they are being replaced. The projected shortage at a time when the largest part of the population will begin to retire and enter the ranks of the elderly could potentially cause serious problems…

  20. The Academic Ranking of World Universities

    ERIC Educational Resources Information Center

    Liu, Nian Cai; Cheng, Ying

    2005-01-01

    Shanghai Jiao Tong University has published on the Internet an Academic Ranking of World Universities that has attracted worldwide attention. Institutions are ranked according to academic or research performance and ranking indicators include major international awards, highly cited researchers in important fields, articles published in selected…

  1. 14 CFR 1214.1105 - Final ranking.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Final ranking. 1214.1105 Section 1214.1105 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1105 Final ranking. Final rankings will be based on a combination...

  2. 14 CFR 1214.1105 - Final ranking.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Final ranking. 1214.1105 Section 1214.1105 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1105 Final ranking. Final rankings will be based on a combination...

  3. 14 CFR 1214.1105 - Final ranking.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Final ranking. 1214.1105 Section 1214.1105 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1105 Final ranking. Final rankings will be based on a combination...

  4. 14 CFR 1214.1105 - Final ranking.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Final ranking. 1214.1105 Section 1214.1105 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1105 Final ranking. Final rankings will be based on a combination...

  5. Class Rank Weighs Down True Learning

    ERIC Educational Resources Information Center

    Guskey, Thomas R.

    2014-01-01

    The process of determining class rank does not help students achieve more or reach higher levels of proficiency. Evidence indicates ranking students may diminish students' motivation. High school educators argue that they are compelled to rank-order graduating students because selective colleges and universities require information about…

  6. The Privilege of Ranking: Google Plays Ball.

    ERIC Educational Resources Information Center

    Wiggins, Richard

    2003-01-01

    Discussion of ranking systems used in various settings, including college football and academic admissions, focuses on the Google search engine. Explains the PageRank mathematical formula that scores Web pages by connecting the number of links; limitations, including authenticity and accuracy of ranked Web pages; relevancy; adjusting algorithms;…

  7. A Comprehensive Analysis of Marketing Journal Rankings

    ERIC Educational Resources Information Center

    Steward, Michelle D.; Lewis, Bruce R.

    2010-01-01

    The purpose of this study is to offer a comprehensive assessment of journal standings in Marketing from two perspectives. The discipline perspective of rankings is obtained from a collection of published journal ranking studies during the past 15 years. The studies in the published ranking stream are assessed for reliability by examining internal…

  8. Colleges Enter the Information Society.

    ERIC Educational Resources Information Center

    Current Issues in Higher Education, 1983

    1983-01-01

    The implications for higher education of the U.S. transformation from an industrial to an information society are discussed in six papers. Russell Edgerton provides an overview in "Entering the Information Society: An Introduction." In "The Computer: An Enabling Instrument," Louis Robinson considers the current era of the personalization of the…

  9. Computer Literacy of Entering Freshmen.

    ERIC Educational Resources Information Center

    Tellep, Andrew

    In an effort to improve college program planning using data on the computer skills of entering freshmen, a survey was conducted to obtain information about computer science programs in Pennsylvania's public schools. The study investigated the material being taught, the background of computer science teachers, program plans, tendencies in the…

  10. Enteral Tube Feeding and Pneumonia

    ERIC Educational Resources Information Center

    Gray, David Sheridan; Kimmel, David

    2006-01-01

    To determine the effects of enteral tube feeding on the incidence of pneumonia, we performed a retrospective review of all clients at our institution who had gastrostomy or jejunostomy tubes placed over a 10-year period. Ninety-three subjects had a history of pneumonia before feeding tube insertion. Eighty had gastrostomy and 13, jejunostomy…

  11. [Enteral nutrition: past and future].

    PubMed

    Bengmark, S; Ortiz de Urbina, J J

    2004-01-01

    Perioperative nutrition has during the last century been transformed from a tool to provide calorie and nitrogen support to a tool to boost the immune system and increase resistance to complications. Despite all progress in medicine and surgery has perioperative morbidity, rate of infections, thrombosis and development of serosal adhesions remained the same as long as can be judged or at least during the last eighty years. Most prone to develop complications are persons above the age of 65 and persons with depressed immunity. About eighty percent of the immune system is localised in the gastrointestinal tract, which offers great opportunities for modulation through enterar nutrition. As the stomach has a tendency to develop postoperative paralysis, tube feeding is often necessary. Andresen demonstrated already in 1918 the advantages of enteral nutrition, which starts already on the table. Mulholland et al and Rhoads and co-workers demonstrated during the 1940s certain advantages of enteral tube feeding. Also works by Alexander, Fischer, Ryan and their co-workers supported the value of early enteral feeding, and suggested enteral feeding as an effective tool to boost the immune system. It was, however, works published in the early nineties by Moore et al and by Kudsk et al, which made surgeons more aware of the advantages of early enteral nutrition. Major surgery is known to have a high rate of complications. Uninterrupted perioperative nutrition, eg nutrition during the night before, during surgery and immediately after offers a strong tool to prevent complications. It is essential that the nutrition provides food also for the colon, e.g. fibres and healthy bacteria (probiotics) to ferment the fibre and boost the immune system. PMID:15049413

  12. Rank-Driven Markov Processes

    NASA Astrophysics Data System (ADS)

    Grinfeld, Michael; Knight, Philip A.; Wade, Andrew R.

    2012-01-01

    We study a class of Markovian systems of N elements taking values in [0,1] that evolve in discrete time t via randomized replacement rules based on the ranks of the elements. These rank-driven processes are inspired by variants of the Bak-Sneppen model of evolution, in which the system represents an evolutionary `fitness landscape' and which is famous as a simple model displaying self-organized criticality. Our main results are concerned with long-time large- N asymptotics for the general model in which, at each time step, K randomly chosen elements are discarded and replaced by independent U[0,1] variables, where the ranks of the elements to be replaced are chosen, independently at each time step, according to a distribution κ N on {1,2,…, N} K . Our main results are that, under appropriate conditions on κ N , the system exhibits threshold behavior at s ∗∈[0,1], where s ∗ is a function of κ N , and the marginal distribution of a randomly selected element converges to U[ s ∗,1] as t→∞ and N→∞. Of this class of models, results in the literature have previously been given for special cases only, namely the `mean-field' or `random neighbor' Bak-Sneppen model. Our proofs avoid the heuristic arguments of some of the previous work and use Foster-Lyapunov ideas. Our results extend existing results and establish their natural, more general context. We derive some more specialized results for the particular case where K=2. One of our technical tools is a result on convergence of stationary distributions for families of uniformly ergodic Markov chains on increasing state-spaces, which may be of independent interest.

  13. Impact of Doximity Residency Rankings on Emergency Medicine Applicant Rank Lists

    PubMed Central

    Peterson, William J.; Hopson, Laura R.; Khandelwal, Sorabh; White, Melissa; Gallahue, Fiona E.; Burkhardt, John; Rolston, Aimee M.; Santen, Sally A.

    2016-01-01

    Introduction This study investigates the impact of the Doximity rankings on the rank list choices made by residency applicants in emergency medicine (EM). Methods We sent an 11-item survey by email to all students who applied to EM residency programs at four different institutions representing diverse geographical regions. Students were asked questions about their perception of Doximity rankings and how it may have impacted their rank list decisions. Results Response rate was 58% of 1,372 opened electronic surveys. This study found that a majority of medical students applying to residency in EM were aware of the Doximity rankings prior to submitting rank lists (67%). One-quarter of these applicants changed the number of programs and ranks of those programs when completing their rank list based on the Doximity rankings (26%). Though the absolute number of programs changed on the rank lists was small, the results demonstrate that the EM Doximity rankings impact applicant decision-making in ranking residency programs. Conclusion While applicants do not find the Doximity rankings to be important compared to other factors in the application process, the Doximity rankings result in a small change in residency applicant ranking behavior. This unvalidated ranking, based principally on reputational data rather than objective outcome criteria, thus has the potential to be detrimental to students, programs, and the public. We feel it important for specialties to develop consensus around measurable training outcomes and provide freely accessible metrics for candidate education. PMID:27330670

  14. Seasonality in Human Zoonotic Enteric Diseases: A Systematic Review

    PubMed Central

    Lal, Aparna; Hales, Simon; French, Nigel; Baker, Michael G.

    2012-01-01

    Background Although seasonality is a defining characteristic of many infectious diseases, few studies have described and compared seasonal patterns across diseases globally, impeding our understanding of putative mechanisms. Here, we review seasonal patterns across five enteric zoonotic diseases: campylobacteriosis, salmonellosis, vero-cytotoxigenic Escherichia coli (VTEC), cryptosporidiosis and giardiasis in the context of two primary drivers of seasonality: (i) environmental effects on pathogen occurrence and pathogen-host associations and (ii) population characteristics/behaviour. Methodology/Principal Findings We systematically reviewed published literature from 1960–2010, resulting in the review of 86 studies across the five diseases. The Gini coefficient compared temporal variations in incidence across diseases and the monthly seasonality index characterised timing of seasonal peaks. Consistent seasonal patterns across transnational boundaries, albeit with regional variations was observed. The bacterial diseases all had a distinct summer peak, with identical Gini values for campylobacteriosis and salmonellosis (0.22) and a higher index for VTEC (Gini = 0.36). Cryptosporidiosis displayed a bi-modal peak with spring and summer highs and the most marked temporal variation (Gini = 0.39). Giardiasis showed a relatively small summer increase and was the least variable (Gini = 0.18). Conclusions/Significance Seasonal variation in enteric zoonotic diseases is ubiquitous, with regional variations highlighting complex environment-pathogen-host interactions. Results suggest that proximal environmental influences and host population dynamics, together with distal, longer-term climatic variability could have important direct and indirect consequences for future enteric disease risk. Additional understanding of the concerted influence of these factors on disease patterns may improve assessment and prediction of enteric disease burden in temperate, developed

  15. Large-scale linear rankSVM.

    PubMed

    Lee, Ching-Pei; Lin, Chih-Jen

    2014-04-01

    Linear rankSVM is one of the widely used methods for learning to rank. Although its performance may be inferior to nonlinear methods such as kernel rankSVM and gradient boosting decision trees, linear rankSVM is useful to quickly produce a baseline model. Furthermore, following its recent development for classification, linear rankSVM may give competitive performance for large and sparse data. A great deal of works have studied linear rankSVM. The focus is on the computational efficiency when the number of preference pairs is large. In this letter, we systematically study existing works, discuss their advantages and disadvantages, and propose an efficient algorithm. We discuss different implementation issues and extensions with detailed experiments. Finally, we develop a robust linear rankSVM tool for public use. PMID:24479776

  16. Two-dimensional ranking of Wikipedia articles

    NASA Astrophysics Data System (ADS)

    Zhirov, A. O.; Zhirov, O. V.; Shepelyansky, D. L.

    2010-10-01

    The Library of Babel, described by Jorge Luis Borges, stores an enormous amount of information. The Library exists ab aeterno. Wikipedia, a free online encyclopaedia, becomes a modern analogue of such a Library. Information retrieval and ranking of Wikipedia articles become the challenge of modern society. While PageRank highlights very well known nodes with many ingoing links, CheiRank highlights very communicative nodes with many outgoing links. In this way the ranking becomes two-dimensional. Using CheiRank and PageRank we analyze the properties of two-dimensional ranking of all Wikipedia English articles and show that it gives their reliable classification with rich and nontrivial features. Detailed studies are done for countries, universities, personalities, physicists, chess players, Dow-Jones companies and other categories.

  17. In vitro selection of enteric microflora for potential use as a competitive exclusion culture against Campylobacter in poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The administration of nonpathogenic microflora in neonatal poultry has been employed to reduce or eliminate the colonization of enteric pathogens. This concept, also called competitive exclusion (CE), although effective against Salmonella, has not consistently worked against Campylobacter. Most CE...

  18. Research update on the poultry enteric viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poultry enteric disease is an ongoing economic problem for the poultry industry in the United States and abroad. The etiologies of the recognized enteric disease syndromes—Poult Enteritis Complex (PEC) and Poult Enteritis Mortality Syndrome (PEMS) in young turkeys, and Runting-Stunting Syndrome (RSS...

  19. Enteral Nutrition in Critical Care

    PubMed Central

    Seron-Arbeloa, Carlos; Zamora-Elson, Monica; Labarta-Monzon, Lorenzo; Mallor-Bonet, Tomas

    2013-01-01

    There is a consensus that nutritional support, which must be provided to patients in intensive care, influences their clinical outcome. Malnutrition is associated in critically ill patients with impaired immune function and impaired ventilator drive, leading to prolonged ventilator dependence and increased infectious morbidity and mortality. Enteral nutrition is an active therapy that attenuates the metabolic response of the organism to stress and favorably modulates the immune system. It is less expensive than parenteral nutrition and is preferred in most cases because of less severe complications and better patient outcomes, including infections, and hospital cost and length of stay. The aim of this work was to perform a review of the use of enteral nutrition in critically ill patients. PMID:23390469

  20. Radiation enteritis and radiation scoliosis

    SciTech Connect

    Shah, M.; Eng, K.; Engler, G.L.

    1980-09-01

    Any patient with radiation scoliosis should be suspected of having a visceral lesion as well. Chronic radiation enteritis may be manifested by intestinal obstruction, fistulas, perforation, and hemorrhage. Intestinal obstruction is the most common complication, and must be differentiated from postoperative cast or from spinal-traction syndrome. Obstruction that does not respond promptly to conservative measures must be treated surgically. Irradiated bowel is ischemic, and necrosis with spontaneous perforation can only be avoided with early diagnosis and surgical intervention.

  1. Novel Receptor Specificity of Avian Gammacoronaviruses That Cause Enteritis

    PubMed Central

    Ambepitiya Wickramasinghe, I. N.; de Vries, R. P.; Weerts, E. A. W. S.; van Beurden, S. J.; Peng, W.; McBride, R.; Ducatez, M.; Guy, J.; Brown, P.; Eterradossi, N.; Gröne, A.; Paulson, J. C.

    2015-01-01

    ABSTRACT Viruses exploit molecules on the target membrane as receptors for attachment and entry into host cells. Thus, receptor expression patterns can define viral tissue tropism and might to some extent predict the susceptibility of a host to a particular virus. Previously, others and we have shown that respiratory pathogens of the genus Gammacoronavirus, including chicken infectious bronchitis virus (IBV), require specific α2,3-linked sialylated glycans for attachment and entry. Here, we studied determinants of binding of enterotropic avian gammacoronaviruses, including turkey coronavirus (TCoV), guineafowl coronavirus (GfCoV), and quail coronavirus (QCoV), which are evolutionarily distant from respiratory avian coronaviruses based on the viral attachment protein spike (S1). We profiled the binding of recombinantly expressed S1 proteins of TCoV, GfCoV, and QCoV to tissues of their respective hosts. Protein histochemistry showed that the tissue binding specificity of S1 proteins of turkey, quail, and guineafowl CoVs was limited to intestinal tissues of each particular host, in accordance with the reported pathogenicity of these viruses in vivo. Glycan array analyses revealed that, in contrast to the S1 protein of IBV, S1 proteins of enteric gammacoronaviruses recognize a unique set of nonsialylated type 2 poly-N-acetyl-lactosamines. Lectin histochemistry as well as tissue binding patterns of TCoV S1 further indicated that these complex N-glycans are prominently expressed on the intestinal tract of various avian species. In conclusion, our data demonstrate not only that enteric gammacoronaviruses recognize a novel glycan receptor but also that enterotropism may be correlated with the high specificity of spike proteins for such glycans expressed in the intestines of the avian host. IMPORTANCE Avian coronaviruses are economically important viruses for the poultry industry. While infectious bronchitis virus (IBV), a respiratory pathogen of chickens, is rather well

  2. Delivery strategies to enhance oral vaccination against enteric infections.

    PubMed

    Davitt, Christopher J H; Lavelle, Ed C

    2015-08-30

    While the majority of human pathogens infect the body through mucosal sites, most licensed vaccines are injectable. In fact the only mucosal vaccine that has been widely used globally for infant and childhood vaccination programs is the oral polio vaccine (OPV) developed by Albert Sabin in the 1950s. While oral vaccines against Cholera, rotavirus and Salmonella typhi have also been licensed, the development of additional non-living oral vaccines against these and other enteric pathogens has been slow and challenging. Mucosal vaccines can elicit protective immunity at the gut mucosa, in part via antigen-specific secretory immunoglobulin A (SIgA). However, despite their advantages over the injectable route, oral vaccines face many hurdles. A key challenge lies in design of delivery strategies that can protect antigens from degradation in the stomach and intestine, incorporate appropriate immune-stimulatory adjuvants and control release at the appropriate gastrointestinal site. A number of systems including micro and nanoparticles, lipid-based strategies and enteric capsules have significant potential either alone or in advanced combined formulations to enhance intestinal immune responses. In this review we will outline the opportunities, challenges and potential delivery solutions to facilitate the development of improved oral vaccines for infectious enteric diseases. PMID:25817337

  3. The enteritis complex in domestic rabbits: A field study

    PubMed Central

    Percy, Dean H.; Muckle, C. Anne; Hampson, Robert J.; Brash, Marina L.

    1993-01-01

    A study of the causative agents of enteritis in domestic rabbits from 44 different accessions is described. In descending order of frequency, the organisms most commonly demonstrated were intestinal and hepatic coccidia (Eimeria species), Escherichia coli, Clostridium spp., Salmonella, Bacillus piliformis, and rotavirus. The species of Eimeria identified included those moderately pathogenic and coccidia of low pathogenicity. Using seven antisera against known enterpathogenic strains of E. coli, only one strain, O15, was identified in three cases. Clostridium perfringens or C. spiroforme was demonstrated in the intestinal contents in 11 cases, and lesions compatible with clostridial enteropathy were identified on gross and histopathology. In a serological survey, over 50% of 200 fryer rabbits submitted to Ontario abattoirs and of animals from commercial rabbitries had detectable antibody to rotavirus, indicating the widespread distribution of rotaviral infections in this species. In the cases of enteritis studied, two or more potentially pathogenic organisms were frequently identified, emphasizing that several different organisms may be acting in concert to produce clinical disease. ImagesFigure 1. PMID:17424177

  4. Decision Tree Modeling for Ranking Data

    NASA Astrophysics Data System (ADS)

    Yu, Philip L. H.; Wan, Wai Ming; Lee, Paul H.

    Ranking/preference data arises from many applications in marketing, psychology, and politics. We establish a new decision tree model for the analysis of ranking data by adopting the concept of classification and regression tree. The existing splitting criteria are modified in a way that allows them to precisely measure the impurity of a set of ranking data. Two types of impurity measures for ranking data are introduced, namelyg-wise and top-k measures. Theoretical results show that the new measures exhibit properties of impurity functions. In model assessment, the area under the ROC curve (AUC) is applied to evaluate the tree performance. Experiments are carried out to investigate the predictive performance of the tree model for complete and partially ranked data and promising results are obtained. Finally, a real-world application of the proposed methodology to analyze a set of political rankings data is presented.

  5. Error analysis of stochastic gradient descent ranking.

    PubMed

    Chen, Hong; Tang, Yi; Li, Luoqing; Yuan, Yuan; Li, Xuelong; Tang, Yuanyan

    2013-06-01

    Ranking is always an important task in machine learning and information retrieval, e.g., collaborative filtering, recommender systems, drug discovery, etc. A kernel-based stochastic gradient descent algorithm with the least squares loss is proposed for ranking in this paper. The implementation of this algorithm is simple, and an expression of the solution is derived via a sampling operator and an integral operator. An explicit convergence rate for leaning a ranking function is given in terms of the suitable choices of the step size and the regularization parameter. The analysis technique used here is capacity independent and is novel in error analysis of ranking learning. Experimental results on real-world data have shown the effectiveness of the proposed algorithm in ranking tasks, which verifies the theoretical analysis in ranking error. PMID:24083315

  6. Glenn Enters his Mercury Capsule

    NASA Technical Reports Server (NTRS)

    1962-01-01

    Astronaut John H. Glenn Jr. enters his Mercury capsule, 'Friendship 7' as he prepares for launch of the Mercury-Atlas rocket. On February 20, 1962 Glenn lifted off into space aboard his Mercury Atlas 6 (MA-6) rocket and became the first American to orbit the Earth. After orbiting the Earth 3 times, Friendship 7 landed in the Atlantic Ocean 4 hours, 55 minutes and 23 seconds later, just East of Grand Turk Island in the Bahamas. Glenn and his capsule were recovered by the Navy Destroyer Noa, 21 minutes after splashdown.

  7. Bayesian nonparametric models for ranked set sampling.

    PubMed

    Gemayel, Nader; Stasny, Elizabeth A; Wolfe, Douglas A

    2015-04-01

    Ranked set sampling (RSS) is a data collection technique that combines measurement with judgment ranking for statistical inference. This paper lays out a formal and natural Bayesian framework for RSS that is analogous to its frequentist justification, and that does not require the assumption of perfect ranking or use of any imperfect ranking models. Prior beliefs about the judgment order statistic distributions and their interdependence are embodied by a nonparametric prior distribution. Posterior inference is carried out by means of Markov chain Monte Carlo techniques, and yields estimators of the judgment order statistic distributions (and of functionals of those distributions). PMID:25326663

  8. Email user ranking based on email networks

    NASA Astrophysics Data System (ADS)

    Tran, Quang Anh; Vu, Minh Tuan; Frater, Michael; Jiang, Frank

    2012-09-01

    In this paper, four spam-filtering approaches based on the mail networks: Clustering, Extended Clustering Coefficient, PageRank Algorithm and Weighted PageRank Algorithm are analyzed. We also propose a couple of fully worked-out datasets against which the experimental comparisons with the respect to the accuracy of email user ranking and spam filtering are conducted. The results indicate that PageRank algorithm and Extended Clustering Coefficient approaches are better than others. The rate of true detection is over 99.5% while the failed alarm remains below 0.5%.

  9. Ranking chemicals based on chronic toxicity data.

    PubMed

    De Rosa, C T; Stara, J F; Durkin, P R

    1985-12-01

    During the past 3 years, EPA's ECAO/Cincinnati has developed a method to rank chemicals based on chronic toxicity data. This ranking system reflects two primary attributes of every chemical: the minimum effective dose and the type of effect elicited at that dose. The purpose for developing this chronic toxicity ranking system was to provide the EPA with the technical background required to adjust the RQs of hazardous substances designated in Section 101(14) of CERCLA or "Superfund." This approach may have applications to other areas of interest to the EPA and other regulatory agencies where ranking of chemicals based on chronic toxicity is desired. PMID:3843499

  10. Regional Enteritis of the Duodenum

    PubMed Central

    Edwards, A. M.; Michalyshyn, B.; Sherbaniuk, R. W.; Costopoulos, L. B.

    1965-01-01

    Forty-three cases of regional enteritis of the duodenum were found in the world literature. Regional duodenitis is relatively uncommon; in one large series of 600 cases of regional enteritis only three involved the duodenum. At the University of Alberta Hospital, in a three-year period (1962 to 1965), the authors encountered five patients with regional duodenitis, demonstrating a spectrum of clinical, radiologic and pathologic characteristics of this disease. The description of these patients brings the world's total to 48 reported cases. Two of these patients had symptoms of severe duodenal obstruction and were relieved by bypass procedures and vagotomy; one required surgery because of co-existent obstructive ileal disease: and two patients have improved on corticoids and salicylazosulfapyridine without surgery. In our experience treatment with corticoids and salicylazosulfapyridine is beneficial. Four of the five patients remain in a state of mild to moderate nutritional impairment and have evidence of intestinal malabsorption. In the fifth case the period of followup is too short to permit assessment. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Figs. 6 (X 50) and 7 (X 450)Fig. 8Fig. 9Fig. 10Fig. 11Fig. 12Figs. 13 and 14 (both X 100)Fig. 15Fig. 16Fig. 17Fig. 18Fig. 19Fig. 20Fig. 21 PMID:5843869