Growth and Extended Survival of Escherichia coli O157:H7 in Soil Organic Matter

Enterohaemorrhagic Escherichia coli, such as serotype O157:H7, are a leading cause of food-associated outbreaks. While the primary reservoir is associated with cattle, plant foods have been associated as sources of human infection. E. coli is able to grow in the tissue of food plants such as spinach. While fecal contamination is the primary suspect, soil has been underestimated as a potential reservoir. Persistence of bacterial populations in open systems is the product of growth, death, predation, and competition. Here we report that E. coli O157:H7 can grow using the soluble compounds in soil, and characterize the effect of soil growth on the stationary phase proteome. E. coli 933D (stxII−) was cultured in Soil Extracted Soluble Organic Matter (SESOM) and the culturable count determined for 24d. The proteomes of exponential and stationary phase populations were characterized by 2D gel electrophoresis and protein spots were identified by MALDI-TOF mass spectrometry. While LB controls displayed a death phase, SESOM grown population remained culturable for 24d, indicating an altered physiological state with superior longevity. This was not due to decreased cell density on entry to stationary phase as 24 h SESOM populations concentrated 10-fold retained their longevity. Principal component analysis showed that stationary phase proteomes from SESOM and LB were different. Differences included proteins involved in stress response, motility, membrane and wall composition, nutrient uptake, translation and protein turnover, and anabolic and catabolic pathways, indicating an altered physiological state of soil-grown cells entering stationary phase. The results suggest that E. coli may be a soil commensal that, in absence of predation and competition, maintains stable populations in soil

An acoustic study of speech production by French children wearing cochlear implants

International audienceThe aim of this paper is to present an acoustic analysis of the speech produced by deaf children wearing cochlear implants (CI). Most studies describing speech production by CI children show that progression after implantation is rapid and that intelligibility and fluency reach typical norms after few months (Sanchez et al. 2006, Ertmer, 2003, Warner-Czyz, 2010), yet some studies show residual difficulties in speech production affecting some consonant and vowel contrasts, though often with conflicting results. The goal of the present study is to carry out an acoustic analysis of the production of several segmental features by 5 French prelingually deaf CI children aged 5 to 10 years (mean age of implantation: 3;3 years), who are compared to a group of 7 NH children aged 6 to 8 year

An acoustic study of speech production by French children wearing cochlear implants

International audienceThe aim of this paper is to present an acoustic analysis of the speech produced by deaf children wearing cochlear implants (CI). Most studies describing speech production by CI children show that progression after implantation is rapid and that intelligibility and fluency reach typical norms after few months (Sanchez et al. 2006, Ertmer, 2003, Warner-Czyz, 2010), yet some studies show residual difficulties in speech production affecting some consonant and vowel contrasts, though often with conflicting results. The goal of the present study is to carry out an acoustic analysis of the production of several segmental features by 5 French prelingually deaf CI children aged 5 to 10 years (mean age of implantation: 3;3 years), who are compared to a group of 7 NH children aged 6 to 8 year

Vowel spaces in French children wearing cochlear implants

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An acoustic study of speech production by French children wearing cochlear implants

International audienceThe aim of this paper is to present an acoustic analysis of the speech produced by deaf children wearing cochlear implants (CI). Most studies describing speech production by CI children show that progression after implantation is rapid and that intelligibility and fluency reach typical norms after few months (Sanchez et al. 2006, Ertmer, 2003, Warner-Czyz, 2010), yet some studies show residual difficulties in speech production affecting some consonant and vowel contrasts, though often with conflicting results. The goal of the present study is to carry out an acoustic analysis of the production of several segmental features by 5 French prelingually deaf CI children aged 5 to 10 years (mean age of implantation: 3;3 years), who are compared to a group of 7 NH children aged 6 to 8 year

Wikipedia: a tool to monitor seasonal diseases trends?

ObjectiveTo explore the interest of Wikipedia as a data source to monitorseasonal diseases trends in metropolitan France.IntroductionToday, Internet, especially Wikipedia, is an important part ofeveryday life. People can notably use this popular free onlineencyclopedia to search health-related information. Recent studiesshowed that Wikipedia data can be used to monitor and to forecastinfluenza-like illnesses in near real time in the United States [1,2].We carried out a study to explore whether French Wikipedia dataallow to monitor the trends of five seasonal diseases in metropolitanFrance: influenza-like illness, gastroenteritis, bronchiolitis,chickenpox and asthma.MethodsTo collect Wikipedia data, we used two free web applications(https://stats.grok.se and https://tools.wmflabs.org/pageviews), whichaggregate daily views for each French entry of the encyclopedia.As some articles have several entries (redirects), we collectedview statistics for all the article entries and added them to make timeseries from January 1st, 2009 to June 30, 2016 (Figure 1). Then, wecompared these data to those of OSCOUR®network, which is a robustnational surveillance system based on the emergency departments.For each disease, we modelized daily variations in Wikipedia viewsaccording to daily visits in ED using Poisson regression modelsallowing for overdispersion. The following adjustment variables wereincluded in the model: long-term trend, seasonality, day of the week.We tested several lags (day-7 to day+7) in order to explore whetherone of the two indicators (Wikipedia view or ED visits) varied earlierthan the other.ResultsThe mean number of daily views was 764 [16-8271] for influenza-like illness, 202 [6-1660] for bronchiolitis, 1228 [59-10030] forgastroenteritis, 475 [21-2729] for asthma and 879 [25-4081] forchickenpox. Times series analyses showed a positive associationbetween page views and ED visits for each seasonal disease (Figure 2).For each increase in 100 Wikipedia views, the number of ED visitsthe same day increased by 2.9% (95% CI=[2.5-3.3]) for influenza,1.8 (95% CI=[1.4-2.2]) for bronchiolitis, 2.4% (95% CI=[2.2-2.7])for gastroenteritis, 1.4% (95% CI=[1.0-1.7]) for asthma and 2.9%(95% CI=[1.7-4.1]) for chickenpox. Globally, the highest relativerisks were observed for lag-1 (day-1) to lag0.ConclusionsThis study allowed to show that French Wikipedia data canbe useful to monitor the trends of seasonal diseases. Indeed, theywere significantly associated with data from a robust surveillancesystem, with a maximum lag of one day. Wikipedia can thereforebe considered as an interesting complementary data source, notablywhen traditional surveillance systems are not available in real time.Further works will be necessary to elaborate forecasting models forthese seasonal diseases.Figure1. Daily number of page views and ED visits for seasonal dieases,January 1st, 2009 to June 30, 2016Figure2. Relative risk between Wikipedia page views and ED visits forseasonal diseases by several lag

Wikipedia: a tool to monitor seasonal diseases trends?

ObjectiveTo explore the interest of Wikipedia as a data source to monitorseasonal diseases trends in metropolitan France.IntroductionToday, Internet, especially Wikipedia, is an important part ofeveryday life. People can notably use this popular free onlineencyclopedia to search health-related information. Recent studiesshowed that Wikipedia data can be used to monitor and to forecastinfluenza-like illnesses in near real time in the United States [1,2].We carried out a study to explore whether French Wikipedia dataallow to monitor the trends of five seasonal diseases in metropolitanFrance: influenza-like illness, gastroenteritis, bronchiolitis,chickenpox and asthma.MethodsTo collect Wikipedia data, we used two free web applications(https://stats.grok.se and https://tools.wmflabs.org/pageviews), whichaggregate daily views for each French entry of the encyclopedia.As some articles have several entries (redirects), we collectedview statistics for all the article entries and added them to make timeseries from January 1st, 2009 to June 30, 2016 (Figure 1). Then, wecompared these data to those of OSCOUR®network, which is a robustnational surveillance system based on the emergency departments.For each disease, we modelized daily variations in Wikipedia viewsaccording to daily visits in ED using Poisson regression modelsallowing for overdispersion. The following adjustment variables wereincluded in the model: long-term trend, seasonality, day of the week.We tested several lags (day-7 to day+7) in order to explore whetherone of the two indicators (Wikipedia view or ED visits) varied earlierthan the other.ResultsThe mean number of daily views was 764 [16-8271] for influenza-like illness, 202 [6-1660] for bronchiolitis, 1228 [59-10030] forgastroenteritis, 475 [21-2729] for asthma and 879 [25-4081] forchickenpox. Times series analyses showed a positive associationbetween page views and ED visits for each seasonal disease (Figure 2).For each increase in 100 Wikipedia views, the number of ED visitsthe same day increased by 2.9% (95% CI=[2.5-3.3]) for influenza,1.8 (95% CI=[1.4-2.2]) for bronchiolitis, 2.4% (95% CI=[2.2-2.7])for gastroenteritis, 1.4% (95% CI=[1.0-1.7]) for asthma and 2.9%(95% CI=[1.7-4.1]) for chickenpox. Globally, the highest relativerisks were observed for lag-1 (day-1) to lag0.ConclusionsThis study allowed to show that French Wikipedia data canbe useful to monitor the trends of seasonal diseases. Indeed, theywere significantly associated with data from a robust surveillancesystem, with a maximum lag of one day. Wikipedia can thereforebe considered as an interesting complementary data source, notablywhen traditional surveillance systems are not available in real time.Further works will be necessary to elaborate forecasting models forthese seasonal diseases.Figure1. Daily number of page views and ED visits for seasonal dieases,January 1st, 2009 to June 30, 2016Figure2. Relative risk between Wikipedia page views and ED visits forseasonal diseases by several lag

DNA as an Adhesin: Bacillus cereus Requires Extracellular DNA To Form Biofilms▿ †

The soil saprophyte Bacillus cereus forms biofilms at solid-liquid interfaces. The composition of the extracellular polymeric matrix is not known, but biofilms of other bacteria are encased in polysaccharides, protein, and also extracellular DNA (eDNA). A Tn917 screen for strains impaired in biofilm formation at a solid-liquid interface yielded several mutants. Three mutants deficient in the purine biosynthesis genes purA, purC, and purL were biofilm impaired, but they grew planktonically like the wild type in Luria-Bertani broth. Biofilm populations had higher purA, purC, and purL transcript ratios than planktonic cultures, as measured by real-time PCR. Laser scanning confocal microscopy (LSCM) of BacLight-stained samples indicated that there were nucleic acids in the cell-associated matrix. This eDNA could be mobilized off the biofilm into an agarose gel matrix through electrophoresis, and it was a substrate for DNase. Glass surfaces exposed to exponentially growing populations acquired a DNA-containing conditioning film, as indicated by LSCM. Planktonic exponential-phase cells released DNA into an agarose gel matrix through electrophoresis, while stationary-phase populations did not do this. DNase treatment of planktonic exponential-phase populations rendered cells more susceptible than control populations to the DNA-interacting antibiotic actinomycin D. Exponential-phase purA cells did not contain detectable eDNA, nor did they convey a DNA-containing conditioning film to the glass surface. These results indicate that exponential-phase cells of B. cereus ATCC 14579 are decorated with eDNA and that biofilm formation requires DNA as part of the extracellular polymeric matrix

Advanced Micro Polymer Tip for SNOM applications

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