Search results for "pathogenic"
showing 10 items of 203 documents
Spanish multicentre study on morbidity and pathogenicity of tracheal bronchus in children.
2019
Tracheal bronchus (TRB) has been generally considered an anatomical variant of the tracheobronchial tree without a precise pathological effect. Its prevalence is estimated to be between 0.2% to 3% of all children undergoing bronchoscopy and scientific information has been limited to case reports or small case series. Our working hypothesis was that TRB could trigger by itself recurrent or persistent respiratory symptoms. The objective of this retrospective and multicentre study of children with a diagnosis of TRB, coming from the main paediatric pulmonology units of Spain, was to determine the anatomical and clinical characteristics, including comorbidities, of TRB in childhood and their im…
Competitive inhibition of three novel bacteria isolated from faeces of breast milk-fed infants against selected enteropathogens.
2013
Numerousin vitroandin vivostudies conducted using different probiotic micro-organisms have demonstrated their ability to interfere with the growth and virulence of a variety of enteropathogens. The reported beneficial effects of the use of probiotics to complement antibiotic therapy or prevent diarrhoea or gastrointestinal infection in infants have increased in recent years. In the present study, we demonstrated the capacity of supernatants obtained from three novel probiotics (Lactobacillus paracaseiCNCM I-4034,Bifidobacterium breveCNCM I-4035 andLactobacillus rhamnosusCNCM I-4036) isolated from the faeces of breastfed infants to inhibit the growth of enterotoxigenic and enteropathogenic (…
Antibacterial effects of enniatins J1 and J3 on pathogenic and lactic acid bacteria
2011
Abstract Enniatins (ENs) are N -methylated cyclohexadepsipeptides, secondary metabolites produced by various species of the genus Fusarium . They are known to act as antifungal, antiyeast and antibacterial and to possess antiinsecticidal and phytotoxic properties. In this study we evaluated for the first time the antibiotic effect of pure fractions of EN J 1 and J 3 on several pathogenic strains and lactic acid bacteria. The ENs J 1 and J 3 were purified from the fermentation extract of Fusarium solani growth on solid medium of wheat kamut, using the technique of the low pressure liquid chromatography (LPLC) followed by a semipreparative liquid chromatography (LC). The purity and the struct…
Salmonella bongori Provides Insights into the Evolution of the Salmonellae
2011
The genus Salmonella contains two species, S. bongori and S. enterica. Compared to the well-studied S. enterica there is a marked lack of information regarding the genetic makeup and diversity of S. bongori. S. bongori has been found predominantly associated with cold-blooded animals, but it can infect humans. To define the phylogeny of this species, and compare it to S. enterica, we have sequenced 28 isolates representing most of the known diversity of S. bongori. This cross-species analysis allowed us to confidently differentiate ancestral functions from those acquired following speciation, which include both metabolic and virulence-associated capacities. We show that, although S. bongori…
A single method for recovery and concentration of enteric viruses and bacteria from fresh-cut vegetables
2011
Fresh-cut vegetables are prone to be contaminated with foodborne pathogens during growth, harvest, transport and further processing and handling. As most of these products are generally eaten raw or mildly treated, there is an increase in the number of outbreaks caused by viruses and bacteria associated with fresh vegetables. Foodborne pathogens are usually present at very low levels and have to be concentrated (i.e. viruses) or enriched (i.e. bacteria) to enhance their detection. With this aim, a rapid concentration method has been developed for the simultaneous recovery of hepatitis A virus (HAV), norovirus (NV), murine norovirus (MNV) as a surrogate for NV, Escherichia coli O157:H7, List…
Mining virulence genes using metagenomics.
2011
When a bacterial genome is compared to the metagenome of an environment it inhabits, most genes recruit at high sequence identity. In free-living bacteria (for instance marine bacteria compared against the ocean metagenome) certain genomic regions are totally absent in recruitment plots, representing therefore genes unique to individual bacterial isolates. We show that these Metagenomic Islands (MIs) are also visible in bacteria living in human hosts when their genomes are compared to sequences from the human microbiome, despite the compartmentalized structure of human-related environments such as the gut. From an applied point of view, MIs of human pathogens (e.g. those identified in enter…
Pristionchus sp. (Rhabditida: Diplogastridae) from Italian populations of Anoplophora chinensis Forster (Coleoptera: Cerambycidae).
2009
Priostonchus sp. n. (Rhabditida: Diplogastridae) is described from a population of Citrus Longhorn Beetles. Alive adults of this Cerambycid were collected from Acer saccharinum trees at Assago and Parabiago (Villastanza), two localities near Milan (Italy). The natural occurrence of the entomogenous nematode in the beetle was not frequent and widespread in the study area. Preliminary laboratory infectivity tests highlight the potential parasitic nature of the nematode. However, it was not successfully maintained in storage and culture. The diplogasterid Pristionchus sp. has rather complicate systematic thus a biomolecular analysis based on DNA is necessary for more specific identification an…
Pathogenicity bioassays of isolates of Beauveria bassiana on Rhynchophorus ferrugineus
2012
BACKGROUND:The control ofRhynchophorusferrugineus (Olivier), themainpalmpest in theMediterraneanBasin, is problematic because of its biology and the current restrictions inmany European countries on the use of chemical insecticides in urban areas. Entomopathogenic fungi have been studied as potential biological control agents, but information on their natural incidence is limited. Strains of Beauveria bassiana (Balsamo) Vuillemin were isolated from symptomatic insects collected on dead palms, and their pathogenicity against different instars of R. ferrugineus was evaluated in the laboratory. RESULTS: The overall percentage of infected insects found in Canary palms was 7%. In laboratory bioa…
In vivo modulation of Hsp70 in Rhynchophorus ferrugineus hemocytes after Bacillus thuringiensis treatment
2010
Heat shock proteins (Hsps) are rapidly synthesized within stressed cells after exposure to an environmental stressor. A variety of environmental stresses, including heat, cold, trace-metal exposure, xenobiotics have been reported to modulate Hsps expression in various organisms. Hsps are grouped into several families based on their protein size. Most organisms have several genes encoding members of this Hsp family. In particularly Hsp70 can be induced quickly under stressful conditions, but return to a normal expression level under non-stressful conditions. Few studies have been done to detect the Hsp70 expression in phytophagous insects towards pathogens. Since a preliminary research discl…
Fungi related to larvae of red palm weevil Rhynchophorous ferrugineus (Coleoptera: Curculionidae)
2010
As a first step to developing effective biocontrol strategies, we analyzed the pathogens and mainly the entomopathogenic fungal species, present into dead larvae of Rhynchophorous ferrugineus; a quarantine pest recently introduced and acclimated in Sicily (Italy). From 2008 to 2010, we estimated the natural larval mortality (> second instar) of R. ferrugineus collected from infested palm Phoenix canariensis; that was variable from 10 to 35%, according to the different seasons Among the different pathogens recorded the fungi seems have an important role, than in order to distinguish saprophytic or opportunistic species from potential pathogens (including the non cultivable ones) we applied d…