Occurrence of antibodies against Chlamydophila abortus in sheep and goats in the Slovak Republic

Chlamydophila abortus is one of the most important causative agents of enzootic abortion and other chlamydial infections of sheep and goats. The presence of specifi c serum antibodies to Chlamydophila abortus was studied in sheep and goats breeding in the Slovak Republic by the complement fi xation test. 22,040 sheep and goats were examined during 5 years. Specifi c anti-Ch. abortus antibodies were found in 2,360 out of 20,878 sheep sera examined (11.7%), and in 85 out of 1,162 examined goats (7.7%). The occurrence of antichlamydial antibodies indicates the importance of performing screening examinations in commercial breeding with the aim of reducing the spread of this disease between animals, and also interrupting the spread and transmission from animals to human

Radiosensitization of resistant (Head and Neck) tumor cells by metal nanoparticles

International audienceSelective targeting of radiation effects to tumors represents a challenge in radiotherapy. Metal nanoparticles (gadolinium, gold, platinum) are preferentially internalized bytumor cells and have been recognized to locally amplify the radiation dose upon irradiation. Nanoparticles delivered in tumor cells might increase tumor­specificity andefficiency of radiotherapy. The physical mechanisms related to the radiation dose amplification by nanoparticles have been already well described; however, cellularstructures targeted by nanoparticles remain unknown. The DNA molecule is the most sensitive and critical cell structure in the cell concerning the effects of ionizingradiation. A question remains open of whether a damage to the nucleus is necessary for the radiosensitization exerted by gadolinium and other nanoparticles.We studied the effect of 3 nm gadolinium based nanoparticles (GdBNs) on the induction and repair of DNA double­strand breaks (DSBs) in the nuclear DNA of U87tumor cells irradiated with g­rays. We used sensitive method of DSB detection based on confocal fluorescence microscopy coupled with immunodetection of twoindependent DSB markers, gH2AX and 53BP1. Our experiments brought surprising results. In the conditions where GdBNs amplify the radiation effects, they remain localized in the cytoplasm and their influence onDSB induction and repair is only insignificant. This suggests that the radiosensitization mediated by GdBNs and potentially other nanoparticles is a cytoplasmic event thatis independent of the nuclear DNA breakage (a phenomenon commonly accepted as the explanation of biological radiation effects). Based on recognized intracellularlocalization of nanoparticles studied, we hypothesize about possible non­DNA targets for (some) nanoparticles

Variable exposure and immunological response to Lyme disease Borrelia among North Atlantic seabird species

Colonial seabirds often breed in large aggregations. These individuals can be exposed to parasitism by the tick Ixodes uriae, but little is known about the circulation of pathogens carried by this ectoparasite, including Lyme disease Borrelia. Here we investigated the prevalence of antibodies (Ab) against Borrelia burgdorferi sensu lato in seabird species sampled at eight locations across the North Atlantic. Using enzyme-linked immunosorbent assay tests, we found that the prevalence of anti-Borrelia Ab in adult seabirds was 39.6% on average (over 444 individuals), but that it varied among colonies and species. Common guillemots showed higher seroprevalence (77.1%±5.9) than black-legged kittiwakes (18.6%±6.7) and Atlantic puffins (22.6%±6.3). Immunoblot-banding patterns of positive individuals, reflecting the variability of Borrelia antigens against which Ab were produced, also differed among locations and species, and did not tightly match the prevalence of Borrelia phylogroups previously identified in ticks collected from the same host individuals. These results represent the first report of the widespread prevalence of Ab against Borrelia within an assemblage of seabird species and demonstrate that Borrelia is an integrated aspect in the interaction between seabirds and ticks. More detailed studies on the dynamics of Borrelia within and among seabird species at different spatial scales will now be required to better understand the implications of this interaction for seabird ecology and the epidemiology of Lyme disease