Search results for "pathogenic"
showing 10 items of 203 documents
Nanostructuring Biopolymers for Improved Food Quality and Safety
2018
Abstract Food-grade biopolymers, apart from their inherent nutritional properties, can be tailored designed for improving food quality and safety, either serving as delivery vehicles for bioactive molecules, or as novel packaging components, not only improving the transport properties of biobased packaging structures, but also imparting active antibacterial and antiviral properties. In this chapter, the potential of different food-grade biopolymers (mainly proteins and carbohydrates but also some biopolyesters) to serve as encapsulating matrices for the protection of sensitive bioactives or as nanostructured packaging layers to improve transport properties and control the growth of pathogen…
Cladosporinone, a new viriditoxin derivative from the hypersaline lake derived fungus Cladosporium cladosporioides
2015
A new cytotoxic viriditoxin derivative, cladosporinone (1), along with the known viriditoxin (2) and two viriditoxin derivatives (3 and 4) were obtained from the fungus C ladosporium cladosporioides isolated from the sediment of a hypersaline lake in Egypt. The structure of the new compound (1) was determined by 1D and 2D NMR measurements as well as by high-resolution ESIMS and electronic circular dichroism spectroscopy. All isolated compounds were studied for their cytotoxicity against the murine lymphoma cell line L5187Y and for their antibiotic activity against several pathogenic bacteria. Viriditoxin (2) was the most active compound in both bioassays. Compound 1 also exhibited strong cy…
Seasonal variations of antimicrobial activity and chemical composition of essential oils extracted from three Citrus limon L. Burm. cultivars
2014
In order to investigate the seasonal variations of antimicrobial properties and chemical composition of essential oils (EOs), three different cultivars of Citrus limon L. Burm. spp. (Femminello Santa Teresa, Monachello and Femminello Continella) were collected at 6-week intervals, from December 2012 to April 2013, for a total of four harvests. The EOs were extracted from lemon peel by hydro-distillation. The antimicrobial activity, tested by paper disc diffusion method, was evaluated against common food-related pathogenic bacteria (Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica and Enterobacter spp.). EOs were more effective against Gram-positive than Gram-negative bacte…
Virulence-Associated Mobile Elements in Bacilli and Clostridia
2014
This chapter focuses on (i) species that induce human diseases, (ii) species that are able to produce toxins, and (iii) the association of appropriate virulence factors with possible mobile elements. With reference to bacilli, the chapter discusses mainly Bacillus anthracis and B. cereus. A section on clostridia focuses on Clostridium perfringens, neurotoxin-producing clostridia, and species capable of producing large clostridial cytotoxins (LCTs). The chapter talks about the contribution of the genetic mobility of virulence genes to the evolution of pathogenic bacilli and clostridia. B. anthracis strains produce a tripartite protein toxin, comprising PA (protective antigen), EF (edema fact…
Behavior of four main dairy pathogenic bacteria during manufacturing and ripening of pecorino siciliano cheese
2020
Background: Consumption of raw cheese may be associated with different diseases. This study aimed to evaluate behavior of four pathogenic bacteria during manufacture and ripening of Protected Designation of Origin (PDO) Pecorino Siciliano cheese.
 Methods: The experimental cheese groups were inoculated with pathogenic bacteria, including Escherichia coli O157, Listeria monocytogenes, Salmonella Enteritidis, and Staphylococcus aureus. The cheese making processes were monitored from milk curdling until 3 months ripened cheeses and the levels of Lactic Acid Bacteria (LAB) and the four dairy pathogens were evaluated by plate counts. Randomly Amplified Polymorphic DNA (RAPD)-Polymerase Chai…
Presence of pathogenic bacteria in ice cubes and evaluation of their survival in different systems
2017
In this study, 60 samples of ice cubes produced at different levels (domestic, restaurant and industrial facilities), within a restricted geographical area, were investigated for their general microbiological characteristics through the analysis of populations other than enteric bacteria. Total mesophilic bacteria were in the range 1.01 Ã 102â9.55 Ã 103, 3.12 Ã 102â6.31 Ã 103and 1.30 Ã 102â3.99 Ã 103CFU/100Â mL of thawed ice from domestic freezer (DF), stock boxes (SB) for self-production performed with ice machines in bars and pubs, and from sales packages (SP) of industrial productions, respectively. Some DF and SP samples were negative for the presence of total psychrotrophic…
pilF polymorphism-based PCR to distinguish Vibrio vulnificus strains potentially dangerous to public health
2010
ABSTRACT Vibrio vulnificus is a heterogeneous species that comprises strains virulent and avirulent for humans and fish, and it is grouped into three biotypes. In this report, we describe a PCR-based methodology that allows both the species identification and discrimination of those isolates that could be considered dangerous to public health. Discrimination is based on the amplification of a variable region located within the gene pilF , which seems to be associated with potential human pathogenicity, regardless of the biotype of the strain.
The long-term cytoskeletal rearrangement induced by rabbit enteropathogenic Escherichia coli is Esp dependent but intimin independent.
1999
Attaching and effacing rabbit enteropathogenic Escherichia coli (REPEC) of the O103 serogroup adhere diffusely on HeLa cells and trigger a slow progressive cytopathic effect (CPE) characterized by the recruitment of vinculin and the assembly of actin stress fibres. In contrast to REPEC O103, the reference human EPEC strain E2348/69 is unable to trigger the CPE. In this study, we have shown first that the fimbrial adhesin AF/R2, which mediates the diffuse adhesion of REPEC O103, was not sufficient to induce the CPE capability upon E2348/69. Non-polar mutants of REPEC O103 for espA, espB, espD and eae were then constructed. The four mutants were unable to induce attaching and effacing lesions…
Population structure and recombination in environmental isolates of Legionella pneumophila
2007
Legionella pneumophila is a water-borne bacteria responsible for most cases of legionellosis, an emerging disease with an increasing incidence in industrialized countries. Although early analysis based on multilocus enzyme electrophoresis (MLEE) described the population structure of this species as clonal, more recent reports have suggested that recombination also contributes to shaping variation across its genome. We report here the results of analysing the nucleotide sequences of 19 loci in 31 environmental samples of L. pneumophila from a small Spanish region (near Alcoi, province of Alicante) where legionellosis has become almost endemic. We analysed the six loci currently incorporated …
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.