Chicken Anti-Campylobacter Vaccine – Comparison of Various Carriers and Routes of Immunization

Campylobacter spp, especially the species Campylobacter jejuni, are important human enteropathogens responsible for millions of cases of gastro-intestinal disease worldwide every year. C. jejuni is a zoonotic pathogen, and poultry meat that has been contaminated by microorganisms is recognized as a key source of human infections. Although numerous strategies have been developed and experimentally checked to generate chicken vaccines, the results have so far had limited success. In this study, we explored the potential use of non-live carriers of Campylobacter antigen to combat Campylobacter in poultry. First, we assessed the effectiveness of immunization with orally or subcutaneously delivered GEM (Gram-positive Enhancer Matrix) particles carrying two Campylobacter antigens: CjaA and CjaD. These two immunization routes using GEMs as the vector did not protect against Campylobacter colonization. Thus, we next assessed the efficacy of in ovo immunization using various delivery systems: GEM particles and liposomes. The hybrid protein CjaAD, which is CjaA presenting CjaD epitopes on its surface, was employed as a model antigen. We found that CjaAD administered in ovo at embryonic development day 18 by both delivery systems resulted in significant levels of protection after challenge with a heterologous Campylobacter jejuni strain. In practice, in ovo chicken vaccination is used by the poultry industry to protect birds against several viral diseases. Our work showed that this means of delivery is also efficacious with respect to commensal bacteria such as Campylobacter. In this study, we evaluated the protection after one dose of vaccine given in ovo. We speculate that the level of protection may be increased by a post-hatch booster of orally delivered antigens

Preliminary computational and experimental design studies of the ISHTAR thermostatic rig for the high-temperature reactors materials irradiation

The Ir radiation System for High-Temperature Reactors (ISHTAR) thermostatic rig will be used to irradiate advanced core material samples in conditions corresponding to those prevailing in the high-temperature reactors (HTRs): these conditions include a stable temperature extending up to 1000°C in the helium atmosphere. Computational and experimental studies concerning the design have been conducted, proving the possibility of these conditions’ fulfi llment inside the rig while maintaining the safety limits for MARIA research reactor. The outcome is the thermostatic rig design that will be implemented in the MARIA reactor. Appropriate irradiation temperature will be achieved by a combination of electric heating with the control system, gamma heating, and a helium insulation gap with precisely designed thickness. The ISHTAR rig will be placed inside the vertical irradiation channel, which is located in the reactor pool. The device is being developed from scratch at the Nuclear Facilities Operation Department of the National Centre for Nuclear Research as a part of the GOSPOSTRATEG programm

Experimental study of ISHTAR thermostatic irradiation device for the MARIA research reactor

Materials and core components for the next generation power reactors technologies require testing that can be performed in existing research reactors. Such experiments employ devices dedicated to reflect the relevant thermal and neutron parameters simulating conditions present in, for example, but not limited to, HTGR reactors. A novel thermostatic irradiation device named ISHTAR (Irradiation System for High-Temperature Reactors) has been designed and constructed in the MARIA research reactor. Its mission is to enable irradiation of samples in controlled, homogeneous temperature field reaching 1000°C and inert gas atmosphere. The high temperature is achieved by a combination of electric and gamma heating, together with carefully designed thermal insulation. Additionally, samples holder made of graphite with high thermal conductivity enables the temperature homogenization in all directions. Device will be placed inside the Beryllium matrix of MARIA core and cooled with forced circulation of water from the reactor pool loop. This paper presents the outcome of experiments conducted with the rig prototype in external hydraulic mock-up of the MARIA reactor irradiation channel. The results have proved that the desired conditions for irradiation of the samples were achieved and their comparison against computational data has shown the adequacy of the design process. Finally, the loss of flow scenario was tested in protected and unprotected conditions (meaning with and without the safety system based on temperature feedback), proving the operational safety of the ISHTAR design. Experimental results will be used in the future to validate the numerical models (two and three dimensional) of the irradiation rig, providing an improved understanding of free convection and radiation phenomena modeling

Lactic acid bacteria as a surface display platform for Campylobacter jejuni antigens.

BACKGROUND Food poisoning and diarrheal diseases continue to pose serious health care and socioeconomic problems worldwide. Campylobacter spp. is a very widespread cause of gastroenteritis. Over the past decade there has been increasing interest in the use of lactic acid bacteria (LAB) as mucosal delivery vehicles. They represent an attractive opportunity for vaccination in addition to vaccination with attenuated bacterial pathogens. METHODS We examined the binding ability of hybrid proteins to nontreated or trichloroacetic acid (TCA)-pretreated LAB cells by immunofluorescence and Western blot analysis. RESULTS In this study we evaluated the possibility of using GEM (Gram-positive enhancer matrix) particles of Lactobacillus salivarius as a binding platform for 2 conserved, immunodominant, extracytoplasmic Campylobacter jejuni proteins: CjaA and CjaD. We analyzed the binding ability of recombinant proteins that contain C. jejuni antigens (CjaA or CjaD) fused with the protein anchor (PA) of the L. lactis peptidoglycan hydrolase AcmA, which comprises 3 LysM motifs and determines noncovalent binding to the cell wall peptidoglycan. Both fused proteins, i.e. 6HisxCjaAx3LysM and 6HisxCjaDx3LysM, were able to bind to nontreated or TCA-pretreated L. salivarius cells. CONCLUSION Our results documented that the LysM-mediated binding system allows us to construct GEM particles that present 2 C. jejuni antigens

Lifting of biogenic compounds by a riverbed from a municipal drainage basin on a day scale

Urban river is the object of very dynamic hydrochemical changes. It was decided to trace the variability of physicochemical elements within 24-hour. One of the rivers in ŁÓdŹ – Olechówka – was selected for research, where, having knowledge from previous research, two measurement-control points were established: first located in the middle course of the river (on its quasi-natural fragment), second at its mouth to the recipient. Between these points, the Olechówka River catchment gains significantly on urbanization. A measurement series during 24-hour was carried out at each of the points, during which in situ measurements Q, T, pH, SEC and O2 were taken every 1 hour and water samples were taken for the analytical determinations NO3-, PO43-, NH4+, TN, TP and Susp. With relatively stable hydrological conditions, a twenty-four hour cycle of changes in nutrient concentrations was observed, whose maxima occur during the night hours

MARIA Reactor Irradiation Technology Capabilities towards Advanced Applications

The MARIA research reactor is designed and operated as a multipurpose nuclear installation, combining material testing, neutron beam experiments, and medical and industrial radionuclide production, including molybdenum-99 (99Mo). Recently, after fuel conversion to LEU and rejuvenation of the staff while maintaining their experience, MARIA has been used to respond to the increased interest of the scientific community in advanced nuclear power studies, both fission and fusion. In this work, we would like to introduce MARIA’ s capabilities in the irradiation technology field and how it can serve future nuclear research worldwide