Search results for "Microbio"
showing 10 items of 8741 documents
Paratransgenic manipulation of tsetsemiR275alters the physiological homeostasis of the fly’s midgut environment
2021
AbstractTsetse flies are vectors of parasitic African trypanosomes (Trypanosomaspp.). Current disease control methods include fly-repelling pesticides, trapping flies, and chemotherapeutic treatment of infected people. Inhibiting tsetse’s ability to transmit trypanosomes by strengthening the fly’s natural barriers can serve as an alternative approach to reduce disease. The peritrophic matrix (PM) is a chitinous and proteinaceous barrier that lines tsetse’s midgut. It protects the epithelial cells from the gut lumen content such as food and invading trypanosomes, which have to overcome this physical barrier to establish an infection. Bloodstream form trypanosomes shed variant surface glycopr…
Lag time for germination of Penicillium chrysogenum conidia is induced by temperature shifts.
2013
In the environment, fungal conidia are subject to transient conditions. In particular, temperature is varying according to day/night periods. All predictive models for germination assume that fungal spores can adapt instantaneously to changes of temperature. The only study that supports this assumption (Gougouli and Koutsoumanis, 2012, Modelling germination of fungal spores at constant and fluctuating temperature conditions. International Journal of Food Microbiology, 152: 153-161) was carried out on Penicillium expansum and Aspergillus niger conidia that, in most cases, already produced germ tubes. In contrast, the present study focuses on temperature shifts applied during the first stages…
Probiotic properties of Brevibacillus brevis and its influence on sea bass (Dicentrarchus labrax) larval rearing
2012
Efficacy of Brevibacillus brevis strain and its influence on larval rearing of sea bass (Dicentrarchus labrax) were investigated in the present work. Biochemical analyses permit to identify this strain as B. brevis. This bacterium has an inhibitory effect against fish pathogenic bacteria, especially the genus of Vibrio. Enzymatic characterization revealed that B. brevis was lipase positive, amylase, lecithinase and caseinase negative. Adherence assays to abiotic surfaces and challenge test with Artemia larvae demonstrate that B. brevis was fairly adherent and play an important role in the enhancement of the protection of Artemia culture against pathogens. Treatment of sea bass larvae with B…
Neutralizing antibodies against rotavirus produced in transgenically labelled purple tomatoes
2011
Edible fruits are inexpensive biofactories for human health-promoting molecules that can be ingested as crude extracts or partially purified formulations. We show here the production of a model human antibody for passive protection against the enteric pathogen rotavirus in transgenically labelled tomato fruits. Transgenic tomato plants expressing a recombinant human immunoglobulin A (hIgA_2A1) selected against the VP8* peptide of rotavirus SA11 strain were obtained. The amount of hIgA_2A1 protein reached 3.6 ± 0.8% of the total soluble protein in the fruit of the transformed plants. Minimally processed fruit-derived products suitable for oral intake showed anti-VP8* binding activity and str…
Association with the Syndrome "Basses Richesses" of Sugar Beet of a Phytoplasma and a Bacterium-Like Organism Transmitted by a Pentastiridius sp.
2002
The syndrome “basses richesses” of sugar beet (SBR) was first observed in 1991 in Burgundy, France. A cixiid planthopper, Pentastiridius beieri, has been proved to be involved in the transmission to sugar beet of a stolbur phytoplasma, which could be detected in some affected plants. In 2000, periwinkle and sugar beet exposed to field-collected cixiids developed symptoms similar to SBR on sugar beet. Use of 4′-6-diamidino-2-phenylindole (DAPI) staining and transmission electron microscopy confirmed the presence of phytoplasma in some of the plants, which were also positive for this pathogen in a polymerase chain reaction (PCR) analysis. A phloem-restricted gram-negative bacteria was seen i…
Interaction of dietary polyphenols and gut microbiota: Microbial metabolism of polyphenols, influence on the gut microbiota, and implications on host…
2020
Abstract The human gastrointestinal tract is inhabited by a vast number of microorganisms that are called as the microbiota. Each individual harbors a unique gut microbial composition, this composition evolves throughout the host's lifetime and it is easily affected by internal or external changes. It has been shown that gut microbiota plays a crucial role in host's health and as this complex community has the ability to interact with each other and with the host's immune system, the presence or absence of some major species can affect the homeostasis. Diet can be considered as one of the pivotal factors in modulating the functionality, integrity, and composition of the gut microbiota as th…
Dominant Lactic Acid Bacteria in Naturally Fermented Milks from Messinese Goat’s Breed
2019
Background: Lactic Acid Bacteria (LAB) are an important group of microorganisms responsible for the fermentation dairy products. This study was done to identify the dominant lactic acid bacteria in naturally fermented milks from Messinese goat’s breed. Methods: Eighteen individual raw milk samples collected from Messinese goat’s breed were acidified at pH 5.20 and left to spontaneously ferment at 37 °C for 4 days. All samples were analyzed for rod- and coccus-shaped LAB. Also, all presumptive LAB were isolated and differentiated according to their phenotypic properties and genetic polymorphisms and then identified by sequencing the 16S rRNA gene. Data were statistically analyzed using SAS 9…
GTPases of the Rho Subfamily Are Required for Brucella abortus Internalization in Nonprofessional Phagocytes
2001
Members of the genus Brucella are intracellular -Proteobacteria responsible for brucellosis, a chronic disease of humans and animals. Little is known about Brucella virulence mechanisms, but the abilities of these bacteria to invade and to survive within cells are decisive factors for causing disease. Transmission electron and fluorescence microscopy of infected nonprofessional phagocytic HeLa cells revealed minor membrane changes accompanied by discrete recruitment of F-actin at the site of Brucella abortus entry. Cell uptake of B. abortus was negatively affected to various degrees by actin, actin-myosin, and microtubule chemical inhibitors. Modulators of MAPKs and protein-tyrosine kinases…
Modulation of immune responses ofRhynchophorus ferrugineus(Insecta: Coleoptera) induced by the entomopathogenic nematodeSteinernema carpocapsae(Nemat…
2014
Aim of this study was to investigate relationships between the red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier) and the entomopathogenic nematode Steinernema carpocapsae (EPN); particularly, the work was focused on the immune response of the insect host in naive larvae and after infection with the EPN. Two main immunological processes have been addressed: the activity and modulation of host prophenoloxidase-phenoloxidase (proPO) system, involved in melanization of not-self and hemocytes recognition processes responsible for not-self encapsulation. Moreover, immune depressive and immune evasive strategies of the parasite have been investigated. Our results suggest that RPW possess a…
Soluble liver antigen (SLA) antibody detection by ELISA and multiplexing technologies
2002
Abstract Objective: Develop and evaluate assays for the detection of antibodies to soluble liver antigen (SLA). SLA, also known as liver/pancreas antibody, was found to be 100% specific for autoimmune hepatitis (AIH) in a recent study of 2000 sera collected from individuals with various disease conditions and healthy individuals (Wies et al., Lancet 2000; 355:1510). Although SLA antibodies occur in only about 30% of patients with autoimmune hepatitis, they are found in some individuals with AIH who are negative for other autoantibodies. Methods: Specimens from patients with autoimmune hepatitis, non-autoimmune liver disease, various autoimmune conditions, as well as specimens from healthy i…