Detection of Listeria pathogens by gradient/constant denaturing gel electrophoresis

Listeriosis is a serious, but preventable disease, and the virulence factor of this disease is produced only by the two pathogenic species L. monocytogenes and L. ivanovii in humans and/or animals. In this study, we used both denaturing gradient gel electrophoresis (DGGE) and constant denaturing gel electrophoresis (CDGE) as molecular methods combined with Polymerase Chain Reaction (PCR) for the detection and identification of Listeria pathogens on 543 samples of raw milk collected from all Syrian provinces. The two methods are based on the PCR amplification of a fragment of the InlC gene (virulence gene) from the studied Listeria species and on the analysis of the PCR products ob-tained by DGGE/CDGE. Based on the differences present in the sequences amplified, it was possible to obtain species-specific DGGE/CDGE migration that allowed fast and easy identification of the virulence and pathogenicity of L. monocytogenes and L. ivanovii in humans and/or animals, in order to reduce the incidence of Listeria bacteria in the environment and foods and to prevent the occur-rence of listeriosis in animal and human hosts

An Oral Vaccine Based on U-Omp19 Induces Protection against B. abortus Mucosal Challenge by Inducing an Adaptive IL-17 Immune Response in Mice

As Brucella infections occur mainly through mucosal surfaces, the development of mucosal administered vaccines could be radical for the control of brucellosis. In this work we evaluated the potential of Brucella abortus 19 kDa outer membrane protein (U-Omp19) as an edible subunit vaccine against brucellosis. We investigated the protective immune response elicited against oral B. abortus infection after vaccination of mice with leaves from transgenic plants expressing U-Omp19; or with plant-made or E. coli-made purified U-Omp19. All tested U-Omp19 formulations induced protection against Brucella when orally administered without the need of adjuvants. U-Omp19 also induced protection against a systemic challenge when parenterally administered. This built-in adjuvant ability of U-Omp19 was independent of TLR4 and could be explained at least in part by its capability to activate dendritic cells in vivo. While unadjuvanted U-Omp19 intraperitoneally administered induced a specific Th1 response, following U-Omp19 oral delivery a mixed specific Th1-Th17 response was induced. Depletion of CD4+ T cells in mice orally vaccinated with U-Omp19 resulted in a loss of the elicited protection, indicating that this cell type mediates immune protection. The role of IL-17 against Brucella infection has never been explored. In this study, we determined that if IL-17A was neutralized in vivo during the challenge period, the mucosal U-Omp19 vaccine did not confer mucosal protection. On the contrary, IL-17A neutralization during the infection did not influence at all the subsistence and growth of this bacterium in PBS-immunized mice. All together, our results indicate that an oral unadjuvanted vaccine based on U-Omp19 induces protection against a mucosal challenge with Brucella abortus by inducing an adaptive IL-17 immune response. They also indicate different and important new aspects i) IL-17 does not contribute to reduce the bacterial burden in non vaccinated mice and ii) IL-17 plays a central role in vaccine mediated anti-Brucella mucosal immunity

The role of flavor and fragrance chemicals in TRPA1 (transient receptor potential cation channel, member A1) activity associated with allergies

TRPA1 has been proposed to be associated with diverse sensory allergic reactions, including thermal (cold) nociception, hearing and allergic inflammatory conditions. Some naturally occurring compounds are known to activate TRPA1 by forming a Michael addition product with a cysteine residue of TRPA1 through covalent protein modification and, in consequence, to cause allergic reactions. The anti-allergic property of TRPA1 agonists may be due to the activation and subsequent desensitization of TRPA1 expressed in sensory neurons. In this review, naturally occurring TRPA1 antagonists, such as camphor, 1,8-cineole, menthol, borneol, fenchyl alcohol and 2-methylisoborneol, and TRPA1 agonists, including thymol, carvacrol, 1’S-1’- acetoxychavicol acetate, cinnamaldehyde, α-n-hexyl cinnamic aldehyde and thymoquinone as well as isothiocyanates and sulfides are discussed

Ultraviolet C lethal effect on Brucella melitensis

The gram-negative bacteria Brucella melitensis was investigated to evaluate its susceptibility to UVC radiation at 254 nm. At an intensity of 18.7 mW/cm 2 of UVC, the time required for inactivation of B. melitensis was 240 seconds in both dark and light, whereas it was 120 seconds and 240 seconds in dark and light respectively at an intensity of 19.5 mW/cm 2 . The results indicate that vaccinal strain of B. melitensis (Rev.1) is more sensitive to UVC than wild B. melitensis strain

Nanoparticles Vaccines Now and Future!

While the advanced use of effective vaccines has had an extraordinary impact on global health, there remain many diseases for which vaccines are not available. The concept of therapeutic infection vaccines is based on the activation of the immune system against infection after the presentation of microbes’ antigens to provide long-term protection against an infection. Nanoparticles (The term “nanoparticle” refers to a crystallite or primary particle measuring less than 100 nm in size.) have shown great potential as delivery systems for infection vaccines as they potentiate the co-</p