Search results for "pathogens"
showing 10 items of 214 documents
Primary Cytomegalovirus Infection in Seronegative Kidney Transplant Patients Is Associated with Protracted Cold Ischemic Time of Seropositive Donor O…
2017
Human Cytomegalovirus (CMV) can lead to primary infection or reactivation in CMV-seronegative or -seropositive kidney transplant recipients, respectively. Complications comprise severe end-organ diseases and acute or chronic transplant rejection. Risk for CMV manifestation is stratified according to the CMV-IgG-serostatus, with donor+/recipient- (D+/R-) patients carrying the highest risk for CMV-replication. However, risk factors predisposing for primary infection in CMV-seronegative recipients are still not fully elucidated. Therefore, we monitored D+/R- high-risk patients undergoing kidney transplantation in combination with antiviral prophylaxis for the incidence of CMV-viremia for a med…
Virulence and Molecular Typing of Vibrio harveyi Strains Isolated from Cultured Dentex, Gilthead Sea Bream and European Sea Bass
2003
Vibrio harveyi was isolated from internal organs or ulcers of diseased and apparently healthy gilthead sea bream (Sparus aurata) and European sea bass (Dicentrarchus labrax) cultured in several fish farms located on the Spanish Mediterranean coast. The prevalence of the bacterium was significantly higher in European sea bass than in gilthead sea bream, and was closely related to the season in both fish species, occurring almost exclusively on warm months (June to November). After phenotypic characterization, a selection of forty five isolates from gilthead sea bream, sea bass, and several isolates previously obtained from common dentex (Dentex dentex) of the same area, were molecularly type…
Bacteria and free-living amoeba in the Lascaux Cave.
2008
3 pages, 1 table, 18 references. The collaboration of the Lascaux restoration team is highly appreciated. We thank Marisa Chelius for valuable comments on the manuscript.
The rise and the fall of a Pseudomonas aeruginosa endemic lineage in a hospital
2021
The biological features that allow a pathogen to survive in the hospital environment are mostly unknown. The extinction of bacterial epidemics in hospitals is mostly attributed to changes in medical practice, including infection control, but the role of bacterial adaptation has never been documented. We analysed a collection of Pseudomonas aeruginosa isolates belonging to the Besançon Epidemic Strain (BES), responsible for a 12year nosocomial outbreak, using a genotype-to-phenotype approach. Bayesian analysis estimated the emergence of the clone in the hospital 5 years before its opening, during the creation of its water distribution network made of copper. BES survived better than the refe…
High temperature and bacteriophages can indirectly select for bacterial pathogenicity in environmental reservoirs
2010
The coincidental evolution hypothesis predicts that traits connected to bacterial pathogenicity could be indirectly selected outside the host as a correlated response to abiotic environmental conditions or different biotic species interactions. To investigate this, an opportunistic bacterial pathogen, Serratia marcescens, was cultured in the absence and presence of the lytic bacteriophage PPV (Podoviridae) at 25°C and 37°C for four weeks (N = 5). At the end, we measured changes in bacterial phage-resistance and potential virulence traits, and determined the pathogenicity of all bacterial selection lines in the Parasemia plantaginis insect model in vivo. Selection at 37°C increased bacterial…
Genetic Characterization of Legionella pneumophila Isolated from a Common Watershed in Comunidad Valenciana, Spain
2013
Legionella pneumophila infects humans to produce legionellosis and Pontiac fever only from environmental sources. In order to establish control measures and study the sources of outbreaks it is essential to know extent and distribution of strain variants of this bacterium in the environment. Sporadic and outbreak-related cases of legionellosis have been historically frequent in the Comunidad Valenciana region (CV, Spain), with a high prevalence in its Southeastern-most part (BV). Environmental investigations for the detection of Legionella pneumophila are performed in this area routinely. We present a population genetics study of 87 L. pneumophila strains isolated in 13 different localities…
Life History Trade-Offs and Relaxed Selection Can Decrease Bacterial Virulence in Environmental Reservoirs
2012
Pathogen virulence is usually thought to evolve in reciprocal selection with the host. While this might be true for obligate pathogens, the life histories of opportunistic pathogens typically alternate between within-host and outside-host environments during the infection-transmission cycle. As a result, opportunistic pathogens are likely to experience conflicting selection pressures across different environments, and this could affect their virulence through life-history trait correlations. We studied these correlations experimentally by exposing an opportunistic bacterial pathogen Serratia marcescens to its natural protist predator Tetrahymena thermophila for 13 weeks, after which we meas…
Assessment of the microbiological quality of fresh produce on sale in Sicily, Italy: preliminary results
2015
Background Fresh produce occupies an increasingly important place in the human food supply because of its health-promoting nutritional properties. Most fresh produce is eaten raw or after minimal processing and, consequently, pathogen contamination can represent a serious health risk. There has been an increase in foodborne outbreaks and cases associated with fresh produce, but literature data about the prevalence of pathogen contamination are inconsistent. This study was undertaken to assess the hygienic quality and the prevalence of the most common bacterial pathogens in fresh produce sold in retail markets in Sicily. A total of 125 samples of different types of vegetables were examined b…
DISEASES DIVERSITY FOR FLAX GENETIC RESOURCES IN LATVIA
2017
Flax ( Linum usitatissimum L) yield of stem and seeds and them quality is influenced by a number of harmful diseases but investigation about pathogens in recent years have not been done in Latvia. Each stage of development of disease is important in the pathogen life cycle and requires certain condition. Goal of this study have identify possibilities of the pathogens and were assess disease severity depending on the genotypes on flax in variable environmental conditions. The resistance to the diseases for 24 flax genotypes and standard variety ‘Vega 2’ were evaluated. The field trials have been carried out over the period from 2015 to 2016 at the Research Centre of Priekuli, part of Vilani…
On the use of carrageenan matrices for the development of antiviral edible coatings of interest in berries
2019
Different film-forming dispersions (FFD) based on κ−, ι− and λ− carrageenans and green tea extract (GTE) have been developed as an innovative strategy to guarantee the food safety of blueberries and raspberries. First, the FFD were characterized (surface tension and viscosity) and the physicochemical properties (water vapour permeability-WVP-, water sorption, contact angle, mechanical properties) of the stand-alone films were evaluated. Then, the FFD were applied to refrigerated-stored raspberries and blueberries, and the antiviral activity against murine norovirus (MNV), a cultivable norovirus surrogate, and hepatitis A virus (HAV) of coated fruits was determined at refrigerated (10 °C) an…