Early adaptation to oxygen is key to the industrially important traits of Lactococcus lactis ssp. cremoris during milk fermentation

Background: Lactococcus lactis is the most used species in the dairy industry. Its ability to adapt to technological stresses, such as oxidative stress encountered during stirring in the first stages of the cheese-making process, is a key factor to measure its technological performance. This study aimed to understand the response to oxidative stress of Lactococcus lactis subsp. cremoris MG1363 at the transcriptional and metabolic levels in relation to acidification kinetics and growth conditions, especially at an early stage of growth. For those purposes, conditions of hyper-oxygenation were initially fixed for the fermentation. Results: Kinetics of growth and acidification were not affected by the presence of oxygen, indicating a high resistance to oxygen of the L. lactis MG1363 strain. Its resistance was explained by an efficient consumption of oxygen within the first 4 hours of culture, leading to a drop of the redox potential. The efficient consumption of oxygen by the L. lactis MG1363 strain was supported by a coherent and early adaptation to oxygen after 1 hour of culture at both gene expression and metabolic levels. In oxygen metabolism, the over-expression of all the genes of the nrd (ribonucleotide reductases) operon or fhu (ferrichrome ABC transports) genes was particularly significant. In carbon metabolism, the presence of oxygen led to an early shift at the gene level in the pyruvate pathway towards the acetate/2,3-butanediol pathway confirmed by the kinetics of metabolite production. Finally, the MG1363 strain was no longer able to consume oxygen in the stationary growth phase, leading to a drastic loss of culturability as a consequence of cumulative stresses and the absence of gene adaptation at this stage. Conclusions: Combining metabolic and transcriptomic profiling, together with oxygen consumption kinetics, yielded new insights into the whole genome adaptation of L. lactis to initial oxidative stress. An early and transitional adaptation to oxidative stress was revealed for L. lactis subsp. cremoris MG1363 in the presence of initially high levels of oxygen. This enables the cells to maintain key traits that are of great importance for industry, such as rapid acidification and reduction of the redox potential of the growth media

Arsonium-Containing Lipophosphoramides, Poly-Functional Nano-Carriers for Simultaneous Antibacterial Action and Eukaryotic Cell Transfection.

International audienceGene therapy of diseases like cystic fibrosis (CF) would consist of delivering a gene medicine towards the lungs via the respiratory tract into the target epithelial cells. Accordingly, poly-functional nano-carriers are required in order to overcome the various successive barriers of such a complex environment, such as airway colonization with bacterial strains. In this work, the antibacterial effectiveness of a series of cationic lipids is investigated before evaluating its compatibility with gene transfer into human bronchial epithelial cells. Among the various compounds considered, some bearing a trimethyl-arsonium headgroup demonstrate very potent biocide effects towards clinically relevant bacterial strains. In contrast to cationic lipids exhibiting no or insufficient antibacterial potency, arsonium-containing lipophosphoramides can simultaneously inhibit bacteria while delivering DNA into eukaryotic cells, as efficiently and safely as in absence of bacteria. Moreover, such vectors can demonstrate antibacterial activity in vitro while retaining high gene transfection efficiency to the nasal epithelium as well as to the lungs in mice in vivo. Arsonium-containing amphiphiles are the first synthetic compounds shown to achieve efficient gene delivery in the presence of bacteria, a property particularly suitable for gene therapy strategies under infected conditions such as within the airways of CF patients

Proposal of a quantitative PCR-based protocol for an optimal Pseudomonas aeruginosa detection in patients with cystic fibrosis

BACKGROUND: The lung of patients with cystic fibrosis (CF) is particularly sensitive to Pseudomonas aeruginosa. This bacterium plays an important role in the poor outcome of CF patients. During the disease progress, first acquisition of P. aeruginosa is the key-step in the management of CF patients. Quantitative PCR (qPCR) offers an opportunity to detect earlier the first acquisition of P. aeruginosa by CF patients. Given the lack of a validated protocol, our goal was to find an optimal molecular protocol for detection of P. aeruginosa in CF patients. METHODS: We compared two formerly described qPCR formats in early detection of P. aeruginosa in CF sputum samples: a qPCR targeting oprL gene, and a multiplex PCR targeting gyrB and ecfX genes. RESULTS: Tested in vitro on a large panel of P. aeruginosa isolates and others gram-negative bacilli, oprL qPCR exhibited a better sensitivity (threshold of 10 CFU/mL versus 730 CFU/mL), whereas the gyrB/ecfX qPCR exhibited a better specificity (90% versus 73%). These results were validated ex vivo on 46 CF sputum samples positive for P. aeruginosa in culture. Ex vivo assays revealed that qPCR detected 100 times more bacterial cells than culture-based method did. CONCLUSION: Based on these results, we proposed a reference molecular protocol combining the two qPCRs, which offers a sensitivity of 100% with a threshold of 10 CFU/mL and a specificity of 100%. This combined qPCR-based protocol can be adapted and used for other future prospective studies

Retrospective studies on rabbit haemorrhagic disease outbreaks caused by RHDV GI.2 virus on farms in France from 2013 to 2018

[EN] Rabbit haemorrhagic disease (RHD) is a critical health threat to the rabbit industry in Europe. In 2018, the French rabbit industry adopted a voluntary control plan against this disease. In this context, two epidemiological studies were conducted on RHD outbreaks that occurred between 2013 and 2018 in France. The objectives were to describe the spread of RHD due to the new genotype RHDV GI.2 (rabbit haemorrhagic disease virus GI.2) and to identify rearing factors influencing the occurrence of the disease in order to guide the prevention measures recommended in the control plan. An analysis of cases on 295 farms between 2013 and 2017 showed that 32% of farms were affected at least once; the incidence of the disease increased in 2016-2017 compared to 2013-2015. Farms already affected in 2013-2015 had a higher risk of being infected in 2016-2017 than those that remained unaffected until 2015 (Relative Risk and 95% Confident Interval 1.7 [1.1-2.7]). A case-control study carried out between 2016 and 2018 on 37 outbreaks and 32 control farms revealed variability in biosecurity and decontamination practices between farms. The risk of being infected tends to be linked to these practices, but certain structural factors (e.g. the manure disposal system, transfer of rabbits at weaning) could also influence the risk of virus introduction into farms. In the context of a limited vaccination coverage of the farms (only females are vaccinated), these hypotheses will be studied further, using information from the RHD outbreak monitoring system implemented at the same time as the control plan in 2018.This study was founded by the French Ministry of Agriculture (2017-430 / 170274).Huneau-Salaün, A.; Boucher, S.; Fontaine, J.; Le Normand, B.; Lopez, S.; Maurice, T.; Nouvel, L.... (2021). Retrospective studies on rabbit haemorrhagic disease outbreaks caused by RHDV GI.2 virus on farms in France from 2013 to 2018. World Rabbit Science. 29(2):87-98. https://doi.org/10.4995/wrs.2021.12800OJS8798292Abrantes J., Van der Loo W., Le Pendu J., Esteves P.J. 2012. Rabbit haemorrhagic disease (RHD) and rabbit haemorrhagic disease virus (RHDV): a review. Vet. Res., 43: 12.https://doi.org/10.1186/1297-9716-43-12Capucci L., Cavadini P., Schiavitto M., Lombardi G., Lavazza A. 2017. Increased pathogenicity in rabbit haemorrhagic disease virus type 2 (RHDV2). Vet. Record., 180: 426. https://doi.org/10.1136/vr.104132Carvalho C.L., Leclerc Duarte E., Monteiro J.M., Afonso C., Pacheco J., Carvalho P., Mendonça P., Botelho A., Albuquerque T., Themudo P., Fevereiro M., Henriques A.M., Santos Barros S., Dias Duarte M. 2017. Progression of rabbit haemorrhagic disease virus 2 upon vaccination in anindustrial rabbitry: a laboratorial approach. World Rabbit Sci., 25: 73-85. https://doi.org/10.4995/wrs.2017.5708Cooke B.D., Fenner F. 2002. Rabbit haemorrhagic disease and the biological control of wild rabbits, Oryctolagus Cuniculus, in Australia and New Zealand. Wildlife Res., 29: 689-706. https://doi.org/10.1071/WR02010Dalton K.P., Balseiro A., Juste R.A., Podadera A., Nicieza I., del Llano D., González R., Martin Alonso J.M., Prieto J.M., Parra F., Casais R. 2018. Clinical course and pathogenicity of variant rabbit haemorrhagic disease virus in experimentally infected adult and kit rabbits: Significance towards control and spread. Vet. Microbiol., 220: 24-32. https://doi.org/10.1016/j.vetmic.2018.04.033Dohoo I., Martin W., Stryhn H. 2003. Measures of disease frequency. In: Veterinary Epidemiologic Research, First Edition, AVC Inc., Charlottetown, Canada, 65-84.Hall R.N., Huang N., Roberts J., Strive T. 2019. Carrion flies as sentinels for monitoring lagovirus activity in Australia. Transboundary Emerg. Dis., 66: 2025-2032. https://doi.org/10.1111/tbed.13250Henning J., Meers J., Davies R., Morris R.S. 2005. Survival of rabbit haemorrhagic disease virus (RHDV) in the environment. Epidemiol. Infect., 133: 719-730. https://doi.org/10.1017/S0950268805003766Hurand J. 2016. L'élevage de lapins de chair en France, résultats technico-économiques 2015. Tema, 40.ITAVI. 2019. Situation de la filière cunicole. Novembre 2019. 6 p. Available athttps://www.itavi.asso.fr/content/note-deconjoncture-lapins-7Accessed December 2019.Le Gall-Reculé G., Zwingelstein F., Boucher S., Le Normand B., Plassiart G., Portejoie Y., Decors A., Bertagnoli S., Guérin J.L., Marchandeau S. 2011. Detection of a new variant of rabbit haemorrhagic disease virus in France. Vet. Rec., 168: 137- 138. https://doi.org/10.1136/vr.d697Le Gall-Reculé G., Lavazza A., Marchandeau S., Bertagnoli S., Zwingelstein F., Cavadini P., Martinelli N., Lombardi G., Guérin J.L., Lemaitre E., Decors A., Boucher S., Le Normand B., Capucci L. 2013. Emergence of a new lagovirus related to Rabbit haemorrhagic disease virus. Vet. Res., 44:81. https://doi.org/10.1186/1297-9716-44-81Le Gall-Reculé G., Boucher S. 2017. Connaissances et actualités sur la maladie hémorragique du lapin. In Proc.: 17èmes Journées de la Recherche Cunicole, 21-22 November, 2017. Le Mans, France. 97-109.Le Minor O., Joudou L., Le Moullec T., Beilvert F. 2017. Innocuité et efficacité de la vaccination à 2 et 3 semaines d'âge contre le virus RHDV2 de la maladie hémorragique virale du lapin (VHD). In Proc.:17èmes Journées de la Recherche Cunicole, 21-22 November, 2017. Le Mans, France. 127-130.Le Minor O., Boucher S., Joudou L., Mellet R., Sourice M., Le Moullec T., Nicoler A., Beilvert F., Sigognault-Flochlay A. 2019. Rabbit haemorrhagic disease: experimental study of a recent highly pathogenic GI.2/RJDV2/b strain and evaluation of vaccine efficacy. World Rabbit Sci., 27: 143-156.https://doi.org/10.4995/wrs.2019.11082Le Pendu J., Abrantes J., Bertagnoli S., Guitton J.S., Le Gall-Reculé G., Lopes A.M., Marchandeau S., Alda F., Almeida T., Célio A. C., Barcena J., Burmakina G., Blanco E., Calvete C., Cavadini P., Cooke B., Dalton K., Mateos M.D., Deptula W., Eden J.S., Wang F., Ferreira C.C., Ferreira P., Foronda P., Gonçalves D., Gavier-Widén D., Hall R., Hukowska-Szematowicz B., Kerr P., Kovaliski J., Lavazza A., Mahar J., Malogolovkin A., Marques R.M., Marques S., Martin-Alonso A., Monterroso P., MorenoS., Mutze G., Naimanis A., Niedzwiedzka-Rystwej P., Peacock D., Parra F., Rocchi M., Rouco C., Ruvoën-Clouet N., Silva E., Silvério D., Strive T., Thompson G., Tokarz-Deptula B., Esteves P. 2017. Proposal for a unified classification system and nomenclature of lagoviruses. J. Gen. Virol., 98: 1658-1666. https://doi.org/10.1099/jgv.0.000840Matthaei M., Kerr P.J., Read A.J., Hick P., Haboury S., Wright J.D., Strive T. 2014. Comparative quantitative monitoring of rabbit haemorrhagic disease viruses in rabbit kittens. Virol. J., 11: 109. https://doi.org/10.1186/1743-422X-11-109Mc Coll K.A., Merchant J.C., Hardy J., Cooke B.D., Robinson A., Westbury H.A. 2002. Evidence for insect transmission of rabbit haemorrhagic disease virus. Epidemiol. Infect., 129: 655-663. https://doi.org/10.1017/S0950268802007756Neimanis A.S., Larsson Pettersson U., Huang N., Gavier-Widen D., Strive T. 2018. Elucidation of the pathology and tissue distribution of Lagovirus europaeus GI.2/RHDV2 (rabbit haemorrhagic disease virus 2) in young and adult rabbits (Oryctolagus cuniculus). Vet. Res., 49:46. https://doi.org/10.1186/s13567-018-0540-zRosell J.M., de la Fuente L.F., Parra F., Dalton K.P., Badiola Sáiz J.I., Pérez de Rozas A., Badiola Díez J.J., Fernández de Luco D., Casal J., Majó N., Casas J., Garriga R., Fernández Magariños X.M. 2019. Myxomatosis and Rabbit Haemorrhagic Disease: A 30-Year Study of the Occurrence on Commercial Farms in Spain. Animals, 9: 780. https://doi.org/10.3390/ani9100780Rouco C., Aguayo-Adán J.A., Santoro S., Abrantes J., Delibes-Mateos M. 2019. Worldwide rapid spread of the novel rabbit haemorrhagic disease virus (GI.2/RHDV2/b). Transboundary Emerg. Dis., 66: 1762-1764.https://doi.org/10.1111/tbed.1318

The WISDOM Radar: Unveiling the Subsurface Beneath the ExoMars Rover and Identifying the Best Locations for Drilling

The search for evidence of past or present life on Mars is the principal objective of the 2020 ESA-Roscosmos ExoMars Rover mission. If such evidence is to be found anywhere, it will most likely be in the subsurface, where organic molecules are shielded from the destructive effects of ionizing radiation and atmospheric oxidants. For this reason, the ExoMars Rover mission has been optimized to investigate the subsurface to identify, understand, and sample those locations where conditions for the preservation of evidence of past life are most likely to be found. The Water Ice Subsurface Deposit Observation on Mars (WISDOM) ground-penetrating radar has been designed to provide information about the nature of the shallow subsurface over depth ranging from 3 to 10 m (with a vertical resolution of up to 3 cm), depending on the dielectric properties of the regolith. This depth range is critical to understanding the geologic evolution stratigraphy and distribution and state of subsurface H2O, which provide important clues in the search for life and the identification of optimal drilling sites for investigation and sampling by the Rover's 2-m drill. WISDOM will help ensure the safety and success of drilling operations by identification of potential hazards that might interfere with retrieval of subsurface samples

Adjuvant Effect of Orally Applied Preparations Containing Non-Digestible Polysaccharides on Influenza Vaccination in Healthy Seniors: A Double-Blind, Randomised, Controlled Pilot Trial.

Senior individuals can suffer from immunosenescence and novel strategies to bolster the immune response could contribute to healthy ageing. In this double-blind, randomised, controlled pilot trial, we investigated the ability of non-digestible polysaccharide (NPS) preparations to enhance the immune response in a human vaccination model. In total, 239 subjects (aged 50-79 years) were randomised to consume one of five different NPS (yeast β-glucan (YBG), shiitake β-glucan (SBG), oat β-glucan (OBG), arabinoxylan (AX), bacterial exopolysaccharide (EPS)) or control (CTRL) product daily for five weeks. After two weeks of intervention, subjects were vaccinated with seasonal influenza vaccine. The post-vaccination increases in haemagglutination inhibition antibody titres and seroprotection rate against the influenza strains were non-significantly enhanced in the NPS intervention groups compared to CTRL. Specifically, a trend towards a higher mean log2 fold increase was observed in the AX group (uncorrected p = 0.074) combined with a trend for an increased seroprotection rate, AX group (48.7%) compared to CTRL (25.6%) (uncorrected p = 0.057), for the influenza A H1N1 strain. Subjects consuming AX also had a reduced incidence of common colds compared to CTRL (1 vs. 8; p = 0.029 in Fisher exact test). No adverse effects of NPS consumption were reported. The findings of this pilot study warrant further research to study AX as an oral adjuvant to support vaccine efficacy

Monoacylglycerol lipase reprograms hepatocytes and macrophages to promote liver regeneration

Background & Aims: Liver regeneration is a repair process in which metabolic reprogramming of parenchymal and inflammatory cells plays a major role. Monoacylglycerol lipase (MAGL) is an ubiquitous enzyme at the crossroad between lipid metabolism and inflammation. It converts monoacylglycerols into free fatty acids and metabolises 2-arachidonoylglycerol into arachidonic acid, being thus the major source of pro-inflammatory prostaglandins in the liver. In this study, we investigated the role of MAGL in liver regeneration. Methods: Hepatocyte proliferation was studied in vitro in hepatoma cell lines and ex vivo in precision-cut human liver slices. Liver regeneration was investigated in mice treated with a pharmacological MAGL inhibitor, MJN110, as well as in animals globally invalidated for MAGL (MAGL-/-) and specifically invalidated in hepatocytes (MAGLHep-/-) or myeloid cells (MAGLMye-/-). Two models of liver regeneration were used: acute toxic carbon tetrachloride injection and two-thirds partial hepatectomy. MAGLMye-/- liver macrophages profiling was analysed by RNA sequencing. A rescue experiment was performed by in vivo administration of interferon receptor antibody in MAGLMye-/- mice. Results: Precision-cut human liver slices from patients with chronic liver disease and human hepatocyte cell lines exposed to MJN110 showed reduced hepatocyte proliferation. Mice with global invalidation or mice treated with MJN110 showed blunted liver regeneration. Moreover, mice with specific deletion of MAGL in either hepatocytes or myeloid cells displayed delayed liver regeneration. Mechanistically, MAGLHep-/- mice showed reduced liver eicosanoid production, in particular prostaglandin E2 that negatively impacts on hepatocyte proliferation. MAGL inhibition in macrophages resulted in the induction of the type I interferon pathway. Importantly, neutralising the type I interferon pathway restored liver regeneration of MAGLMye-/- mice. Conclusions: Our data demonstrate that MAGL promotes liver regeneration by hepatocyte and macrophage reprogramming. Impact and Implications: By using human liver samples and mouse models of global or specific cell type invalidation, we show that the monoacylglycerol pathway plays an essential role in liver regeneration. We unveil the mechanisms by which MAGL expressed in both hepatocytes and macrophages impacts the liver regeneration process, via eicosanoid production by hepatocytes and the modulation of the macrophage interferon pathway profile that restrains hepatocyte proliferation.The authors thank V. Fauveau, Institut Cochin, for help in surgery experiments; Olivier Thibaudeau of the Plateau de Morphologie Facility (INSERM UMR 1152, France) and Nicolas Sorhaindo of the Plateforme de Biochimie (CRI, INSERM UMR1149) for their help in the histology and liver function tests; and K. Bailly from the cytometry platform of Cochin Institute and H. Fohrer-Ting from the Centre de Recherche des Cordeliers, Paris University, for cell sorting analyses.Scopu