Toxoplasma gondii is a worldwide protozoan parasite which causes severe disease in congenitally infected children and in immunocompromised patients. Besides the well-defined cytoplasmic and membrane antigens of tachyzoites, we felt that excreted/secreted antigens could play a major role in the immune response. We first report the development of a well-controlled procedure for obtaining tachyzoite excreted/secreted antigens (E/SA) in cell-free incubation media. The E/SA immunogenic in human, rat and mouse toxoplasmosis were then characterized. The major E/SA recognized by human sera from the chronic phase of toxoplasmosis had molecular weights of 108, 97, 86, 69, 60, 57, 42, 39, 28.5, 27 and 26 kD. When injected into +/+ Fischer rats, E/SA elicited high antibody titres. In addition, passive transfer of these sera to highly susceptible nu/nu littermates induced a significant degree of protection towards the virulent RH strain of T. gondii. This work, which demonstrates the key role played by E/SA in the protective immune response, suggests that these antigens should be of value both for diagnostic purposes and for the development of new strategies for immunization against toxoplasmosis.
The first detection of Aethina tumida Murray (the small hive beetle) in Italy occurred on 5 September 2014. Three nuclei containing honey bees (Apis mellifera) and located in a clementine (citrus) orchard near an important international harbour in the Calabria region (southern Italy) were heavily infested with adult and larval A. tumida. A. tumida infestation is a notifiable disease of honey bees in the European Union as well as an OIE listed disease. To prevent any A. tumida introduction, the importation of honey bees is regulated strictly in the European Union (Commission Regulation (EU) No. 206/2010). Early reaction measures adopted in Italy require that beekeepers must notify A. tumida discovery to the local veterinary services and cannot move their colonies. Furthermore, a protection area (20 km radius) and surveillance (100 km radius) zone should be established. The surveillance zone now includes the entire territory of Calabria region. Compulsory visits to all apiaries in the protection zone with the collection of the spatial information by means of a georeferentiation process (georeferentiation can be defined as the process to describe a location relative to the earth, in this context the process consists on the collection of the spatial coordinate of a point that represents the spatial location of the apiaries by means of a GPS device) and colony inspection according to 5% expected prevalence (95% CI) are applied. Destruction of infested apiaries is compulsory and the soil under the infested colonies must be ploughed and treated with pyrethroids. If apiaries in the protection zone are found to be negative, traps are placed. In the surveillance zone, veterinarians visit apiaries that are selected according to a risk analysis (migration in infested areas, honey bee or materials exchange) or randomly and colonies are inspected according to 2% expected prevalence (95% CI). Furthermore, in Italy as well in the rest of Europe, investigations are in progress by competent authorities to make an inventory of all bees and colonies moved from Calabria during 2014.Subsequent controls on colonies should be implemented. People from the honey bee network (beekeepers, veterinarians, beekeeping material producers and distributors) should be aware and informed of the hazard posed by A. tumida to honey bees. Detección de Aethina tumida Murray (Coleoptera: Nitidulidae) en Italia: los brotes y las medidas de reacción tempranaResumen La primera detección de Aethina tumida Murray (el pequeño escarabajo de la colmena) en Italia se produjo el 5 de septiembre de 2014. Tres núcleos ubicados en un huerto de clementinas cerca de un importante puerto internacional en la región de Calabria (sur de Italia) aparecieron muy infectados con la presencia de coleópteros adultos y de larvas. La infestación por A. tumida es una enfermedad de las abejas de Downloaded by [UQ Library] at 09:34 16 June 2015 570 Mutinelli et al.
Cell-mediated immunity is thought to play a decisive role in protecting cats against feline infectious peritonitis (FIP), a progressive and lethal coronavirus disease. In view of the potential of DNA vaccines to induce cell-mediated responses, their efficacy to induce protective immunity in cats was evaluated. The membrane (M) and nucleocapsid (N) proteins were chosen as antigens, because antibodies to the spike (S) protein of FIP virus (FIPV) are known to precipitate pathogenesis. However, vaccination by repeated injections of plasmids encoding these proteins did not protect kittens against challenge infection with FIPV. Also, a prime-boost protocol failed to afford protection, with priming using plasmid DNA and boosting using recombinant vaccinia viruses expressing the same coronavirus proteins. Because of the role of IL-12 in initiating cell-mediated immunity, the effects of co-delivery of plasmids encoding the feline cytokine were studied. Again, IL-12 did not meet expectations -on the contrary, it enhanced susceptibility to FIPV challenge. This study shows that DNA vaccination failed to protect cats against FIP and that IL-12 may yield adverse effects when used as a cytokine adjuvant.
-Aethina tumida (small hive beetle, SHB) was first detected in September 2014 in Calabria region, southern Italy, and in a single apiary in Sicily in November 2014. In September 2015, SHB was again recorded in Calabria, and in 2016, only sentinel honey bee nucleus colonies were found to be infested. Its phylogenetic relationship and possible origin were investigated comparing the cox1 sequences with the corresponding region available in the GenBank database. The neighbour-joining method revealed that the first Italian specimen belonged to a group also containing an African specimen from Cameroon. The Italian specimens differ from the SHBs spread worldwide and are split into two different groups: group B1 includes the AfricCam3 sequence and the first SHB identified in Calabria; group B2 includes specimens from Calabria and the only one from Sicily which share identical cox1 sequences. SHB in Italy appears to have been introduced from Africa and includes independent or contemporary incursions in the two concerned regions. The most likely scenario is that SHB was introduced into Calabria followed by man-mediated migration to Sicily.Aethina tumida / Apis mellifera / cox1 gene / exotic bee infestation / southern Italy
ABSTRACT:Border disease virus (BDV) causes high mortality in Pyrenean chamois (Rupicapra pyrenaica) on the French and Spanish sides of the Pyrenees Mountains. We investigated the pathology induced by BDV in pregnant chamois via experimental infection. Three females were inoculated during the second third of pregnancy with a BDV-4 subgroup strain isolated from a wild Pyrenean chamois during an acute epizootic. A fourth pregnant chamois and one nonpregnant ewe were kept as negative controls. Animals were monitored to assess clinical signs, hematology, viremia, and serology. Postmortem examinations included necropsy, histopathology, and quantification of viral RNA in organs. Pregnancy was unsuccessful in all inoculated animals. One died 24 days postinoculation (dpi) without showing any precursory clinical signs. The second animal had profuse diarrhea from 13 dpi to its death at 51 dpi. The third aborted at 46 dpi and was euthanized at 51 dpi. All animals were viremic from 4 dpi until death. Neutralizing antibodies against BDV-4 were detected from 12 dpi. Necropsies showed generalized lymphadenomegaly, associated in one case with disseminated petechial hemorrhages in the digestive tract. Seventyeight of 79 organs from inoculated adults and their fetuses had detectable viral RNA. The main histologic lesions in adults were mild lymphohistiocytic encephalitis associated with moderate or moderately severe lymphoid depletion. Control animals remained negative for virus (in blood and organs), antibody, and lesions upon postmortem examination. BDV infection during pregnancy in Pyrenean chamois causes severe disease leading to abortion, then death. Despite 100% fetal death following inoculation, viral RNA was recovered from all organs of infected fetuses, suggesting that persistently infected offspring could be born. Our results may help explain the reported decrease in chamois populations in several areas and suggest that great care must be taken when interpreting infection status for wildlife.
In the present work we demonstrate the implication of excreted-secreted antigens in eliciting the protective cell-mediated immunity developed by rats toward Toxoplasma gondii. We first showed that 104 specific T cells from T. gondii-infected rats conferred to nude rats the ability to resist an infection by the highly virulent RH strain of T. gondii. In a second series of experiments, the role of excreted-secreted antigens in this protection was demonstrated. After the adoptive transfer to nude rats of various doses (103, 104, 105) of excreted-secreted antigen-specific helper T cells (propagated in vitro during one month), significant protection toward T. gondii was induced. Moreover, these cells were responsible for a specific antibody response in nude rats, which are normally unable to develop any specific humoral response. The specificity of these antibodies was directed toward different molecules with molecular masses of 104, 97, 57, 39, 30, 21, and 18 kilodaltons; some of these have been previously characterized as major excreted-secreted antigens.
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