Search results for "bacteri"

1,2-DICHLOROETHANE CONTAMINATED AQUIFER: MICROBIAL COMMUNITY RESPONSE TO BIOSTIMULATION IN MICROCOSM

2022

Failure to differentiate Cryptosporidium parvum from C. meleagridis based on PCR amplification of eight DNA sequences.

1998

ABSTRACT In order to determine the specificities of PCR-based assays used for detecting Cryptosporidium parvum DNA, eight pairs of previously described PCR primers targeting six distinct regions of the Cryptosporidium genome were evaluated for the detection of C. parvum , the agent of human cryptosporidiosis, and C. muris , C. baileyi , and C. meleagridis , three Cryptosporidium species that infect birds or mammals but are not considered to be human pathogens. The four Cryptosporidium species were divided into two groups: C. parvum and C. meleagridis , which gave the same-sized fragments with all the reactions, and C. muris and C. baileyi , which gave positive results with primer pairs targ…

Extracellular Vesicles and Tumor-Immune Escape: Biological Functions and Clinical Perspectives

2020

The modulation of the immune system is one of the hallmarks of cancer. It is now widely described that cancer cells are able to evade the immune response and thus establish immune tolerance. The exploration of the mechanisms underlying this ability of cancer cells has always attracted the scientific community and is the basis for the development of new promising cancer therapies. Recent evidence has highlighted how extracellular vesicles (EVs) represent a mechanism by which cancer cells promote immune escape by inducing phenotypic changes on different immune cell populations. In this review, we will discuss the recent findings on the role of tumor-derived extracellular vesicles (TEVs) in re…

Molecular mechanisms of primary and secondary mucosal immunity using avian infectious bronchitis virus as a model system

2007

Although mucosal immune responses are critical for protection of hosts from clinical illness and even mortality caused by mucosal pathogens, the molecular mechanism of mucosal immunity, which is independent of systemic immunity, remains elusive. To explore the mechanistic basis of mucosal protective immunity, gene transcriptional profiling in mucosal tissues was evaluated after the primary and secondary immunization of animals with an attenuated avian infectious bronchitis virus (IBV), a prototype of Coronavirus and a well-characterized mucosal pathogen. Results showed that a number of innate immune factors including toll-like receptors (TLRs), retinoic-acid-inducible gene-1 (RIG-1), type I…

Immune cell score, PD-L1 expression and prognosis in esophageal cancer

2021

Immune cell score, PD-L1 expression and prognosis in esophageal cancer

Photodegradation of lincomycin in aqueous solution

2006

Aqueous solutions of lincomycin were irradiated with UV light in homogeneous and heterogeneous systems. Lincomycin disappeared in both systems but the presence ofTiO2noticeably accelerated the degradation of the antibiotic in comparison with direct photolysis. The rate of decomposition was dependent on the concentration of lincomycin and followed a pseudo-first-order kinetics. Photolysis involved only the oxidation of lincomycin without mineralization. Differently, the treatment withTiO2and UV light resulted in a complete mineralization of the antibiotic. The degradation pathways involved S- and N-demethylation and propyldealkylation. The mineralization of the molecule led to the formation …

Increase in midgut microbiota load induces an apparent immune priming and increases tolerance to Bacillus thuringiensis

2010

Summary The insect immune system is comprised of both humoral and cellular components that are mobilized in response to parasitic or pathogenic infections. Activation of the immune response implies a consid- erable expenditure of energy and that is why insects rely on inducible pathways that are activated after coming into contact with the pathogenic agent. Known as immune priming, insects can prolong the activation of the immune response and transmit their immune status to the next generation. Starting from a laboratory colony of the lepidopteran Spodoptera exigua and using the lytic zone assay as a measure of the immune status, we selected for a sub-colony with high levels of immune activ…

Biofilm Related to Animal Health, Zoonosis and Food Transmitted Diseases: Alternative Targets for Antimicrobial Strategy?

2012

The biofilm is a complex community of microbial cells that are associated with a surface and enclosed in a self-produced biopolymer matrix. Such structured community is a response of bacteria to a signal system named quorum sensing (QS) constituted by inter-cell communication through the production of small molecules called autoinducers (AIs) that trigger a cascade of events in gene expression. When the concentration of the AIs molecules reach a certain threshold, the bacterial population acts as a single organism, collectively expressing virulence or biofilm forming genes. Gram-positive bacteria use modified oligopeptides as QS effectors molecules.

Okadaic Acid, an Apoptogenic Toxin for Symbiotic/Parasitic Annelids in the Demosponge Suberites domuncula

2006

ABSTRACT The role of okadaic acid (OA) in the defense system of the marine demosponge Suberites domuncula against symbiotic/parasitic annelids was examined. Bacteria within the mesohyl produced okadaic acid at concentrations between 32 ng/g and 58 ng/g of tissue (wet weight). By immunocytochemical methods and by use of antibodies against OA, we showed that the toxin was intracellularly stored in vesicles. Western blotting experiments demonstrated that OA also existed bound to a protein with a molecular weight of 35,000 which was tentatively identified as a galectin (by application of antigalectin antibodies). Annelids that are found in S. domuncula undergo apoptotic cell death. OA is one ca…

Bioaccessibility Study of Aflatoxin B1 and Ochratoxin A in Bread Enriched with Fermented Milk Whey and/or Pumpkin

2021

The presence of mycotoxins in cereals and cereal products remains a significant issue. The use of natural ingredients such as pumpkin and whey, which contain bioactive compounds, could be a strategy to reduce the use of conventional chemical preservatives. The aim of the present work was to study the bioaccessibility of aflatoxin B1 (AFB1) and ochratoxin (OTA) in bread, as well as to evaluate the effect of milk whey (with and without lactic acid bacteria fermentation) and pumpkin on reducing mycotoxins bioaccessibility. Different bread typologies were prepared and subjected to an in vitro digestion model. Gastric and intestinal extracts were analyzed by HPLC–MS/qTOF and mycotoxins bio…