Protective adaptive immunity to Chlamydophila abortus infection and control of ovine enzootic abortion (OEA)

Ovine enzootic abortion (OEA) remains a major problem in sheep-rearing countries despite the availability of protective vaccines. The causative agent, Chlamydophila abortus, is a Gram-negative bacterium that can induce a persistent, subclinical infection in non-pregnant sheep. The development of a new safe, effective and practical vaccine requires a detailed understanding of host-pathogen interactions and the identification of clear correlates of protection. Since disease (abortion) is only observed during pregnancy, the nature of host immunity to C. abortus and the specialised immunological features that permit maternal acceptance of the semi-allogeneic fetus are central to the pathogenesis of OEA. We review the current literature on persistence of C. abortus, host immunity to infection and mechanisms of abortion. We identify the key outstanding questions surrounding OEA and discuss the current knowledge gaps with a view to developing improved control strategies.     

High rate of transplacental infection and transmission of Neospora caninum following experimental challenge of cattle at day 210 of gestation

In order to investigate the pathogenesis of neosporosis following a primary infection in late pregnancy, cattle were subcutaneously challenged with 5 × 10⁸Neospora caninum (NC1 isolate) tachyzoites at day 210 of gestation and serial necropsies were then carried out at 14, 28, 42 and 56 days post-infection (dpi). No abortions occurred and all the foetuses were viable at the time of euthanasia. There was a high rate of vertical transmission, as parasites were detected by immunohistochemical labelling and PCR in all the foetuses from 28 dpi. Focal necrotic lesions were observed in the placentomes of the placenta from 28 dpi and showed resolution during later time points, denoted by infiltration of inflammatory cells at 42 dpi and fibrosis at 56 dpi. Foetuses at 28 and 42 dpi showed scarce and isolated lesions which are unlikely to represent a threat to foetal viability. No lesions were observed in the foetuses at 14 or 56 dpi suggesting control of the infection and resolution of the lesions by maternal and foetal immune responses. Once infection was established, it could not be cleared from the host and vertical transmission of the parasite occurred in all infected hosts. Parasite was detected in the placenta at 28 dpi, while in previous experimental infections of cattle at day 70 and 140 of gestation using the same challenge model, it was already present at day 14 post infection. This suggests that a change in the maternal immune response plays a crucial role in limiting the initial infection during the last term of pregnancy.     

Induction of inflammatory host immune responses by organisms belonging to the genera Chlamydia/Chlamydophila

Chlamydia/Chlamydophila are a family of intracellular gram-negative bacteria that infect their hosts primarily via mucosal epithelia. Chronic disease associated with bacterial persistence, inflammation and tissue damage are common sequelae of infection with these organisms. Human epithelial cell lines respond to infection by releasing pro-inflammatory cytokines and chemokines such as interleukin (IL)-6 and IL-8, and upregulating the expression of mRNA encoding Iκ-Bα, the endogenous inhibitor of NF-κB. However, Iκ-Bα is not upregulated in response to bacterial lipopolysaccharide (LPS). The failure of epithelial cells to respond to LPS is associated with the absence of surface expression of CD14. Identification of the components of Chlamydia/Chlamydophila that can induce pro-inflammatory mediators coupled with the mechanisms by which epithelial cells detect infection and respond accordingly will advance the development of preventative strategies.     

Microbial metabolism of fenoxaprop-ethyl

Fenoxaprop-ethyl was found to be metabolized by a mixed microbial population isolated from a leachate from a landfill. Fenoxaprop acid and 6-chloro-2(3H)-benzoxazolone were detected as metabolic products in the culture broths. It was shown that the microbial population could utilize fenoxapropethyl as a source of carbon and nitrogen, but the presence of an additional source of carbon increased the metabolism rate.     

Characterisation of gluten-free pasta through conventional and innovative methods: Evaluation of the uncooked products

Formation of a gluten protein network is fundamental for the texture and the overall quality of pasta. Replacement of the gluten network in gluten-free pasta is a major technological challenge, and the conventional technological processes have to be adapted to non-gluten formulations. The wide variety of raw materials and technologies used in the production of commercial gluten-free pasta stems from the – still on-going – search for solutions to these problems. The aim of this study was to evaluate the characteristics of different commercial gluten-free spaghetti currently available on the market, focusing on starch and protein organisation. Taking into account the chemical and biochemical properties of the samples, and their relationships to the physical characteristics of these products we looked at how some molecular properties relate to the final structure and quality of gluten-free pasta. Phenomena related to starch retrogradation were found to play a central role for the final texture of the products. At the same time, the origin of proteins included in the formulation was found to govern the protein–protein interactions, especially in those samples including proteins from different vegetable sources.     

Antigenotoxic Effects of Piquiá (Caryocar villosum) in Multiple Rat Organs

This study investigated the in vivo genotoxicity of piquiá pulp (Caryocar villosum) and its potential antigenotoxicity on doxorubicin (DXR)-induced DNA damage by comet assay and micronucleus test. In addition, the phytochemicals present in piquiá pulp were determined. Piquiá fruit pulp (75, 150 or 300?mg/kg b.w.) was administered by gavage to Wistar rats for 14?days, and the animals received an injection of saline or DXR (15?mg/kg b.w., i.p.) 24 h before they were euthanized. The phytochemical analysis revealed the presence of carotenoids; phenolic compounds, including flavonoids; tannins and α-tocopherol in piquiá pulp. No statistically significant differences were observed in the evaluated parameters, demonstrating the absence of cytotoxic and genotoxic effects of piquiá pulp at all tested doses. In liver, kidney, cardiac and bone marrow cells, piquiá significantly reduced the DNA damage induced by DXR. Our results showed that the lowest piquiá dose caused the largest decrease in DNA damage and the highest dose caused the smallest decrease, demonstrating an inverse dose-response of piquiá pulp. Furthermore, we observed a difference in the potential antigenotoxic effects in several tissues. In conclusion, our results demonstrated that piquiá pulp was not genotoxic and inhibited the genotoxicity induced by DXR, but some of the protective effects that were observed depended on the doses and experimental conditions. Therefore, further investigations are needed to clarify how piquiá pulp positively affects human health.