Growth and metabolic characteristics of fastidious meat-derived Lactobacillus algidus strains

Lactobacillus algidus is a meat spoilage bacterium often dominating the bacterial communities on chilled, packaged meat. Yet, L. algidus strains are rarely recovered from meat, and only few studies have focused on this species. The main reason limiting detailed studies on L. algidus is related to its poor growth on the media routinely used for culturing food spoilage bacteria. Thus, our study sought to develop reliable culture media for L. algidus to enable its recovery from meat, and to allow subculturing and phenotypic analyses of the strains. We assessed the growth of meat-derived L. algidus strains on common culture media and their modifications, and explored the suitability of potential media for the recovery of L. algidus from meat. Moreover, we determined whether 12 meat-derived L. algidus strains selected from our culture collection produce biogenic amines that may compromise safety or quality of meat, and finally, sequenced de novo and annotated the genomes of two meat-derived L. algidus strains to uncover genes and metabolic pathways relevant for phenotypic traits observed. MRS agar supplemented with complex substances (peptone, meat and yeast extract, liver digest) supported the growth of L. algidus, and allowed the recovery of new L. algidus isolates from meat. However, most strains grew poorly on standard MRS agar and on general-purpose media. In MRS broth, most strains grew well but a subset of strains required supplementation of MRS broth with additional cysteine. Supplementation of MRS broth with catalase allowed growth in aerated cultures suggesting that the strains produced hydrogen peroxide when grown aerobically. The strains tested (n = 12) produced ornithine from arginine and putrescine from agmatine, and two strains produced tyramine from tyrosine. Our findings reveal that L. algidus populations are underestimated if routine culture protocols are applied, and prompt concerns that L. algidus may generate tyramine or putrescine in meat or fermented meat products.Peer reviewe

trained immunity confers broad spectrum protection against bacterial infections

Abstract Background The innate immune system recalls a challenge to adapt to a secondary challenge, a phenomenon called trained immunity. Training involves cellular metabolic, epigenetic and functional reprogramming, but how broadly trained immunity protects from infections is unknown. For the first time, we addressed whether trained immunity provides protection in a large panel of preclinical models of infections. Methods Mice were trained and subjected to systemic infections, peritonitis, enteritis, and pneumonia induced by Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Citrobacter rodentium, and Pseudomonas aeruginosa. Bacteria, cytokines, leukocytes, and hematopoietic precursors were quantified in blood, bone marrow, and organs. The role of monocytes/macrophages, granulocytes, and interleukin 1 signaling was investigated using depletion or blocking approaches. Results Induction of trained immunity protected mice in all preclinical models, including when training and infection were initiated in distant organs. Trained immunity increased bone marrow hematopoietic progenitors, blood Ly6Chigh inflammatory monocytes and granulocytes, and sustained blood antimicrobial responses. Monocytes/macrophages and interleukin 1 signaling were required to protect trained mice from listeriosis. Trained mice were efficiently protected from peritonitis and listeriosis for up to 5 weeks. Conclusions Trained immunity confers broad-spectrum protection against lethal bacterial infections. These observations support the development of trained immunity-based strategies to improve host defenses

Short-term exercise affects cardiac function ex vivo partially via changes in calcium channel levels, without influencing hypoxia sensitivity

Exercise is known to improve cardiac recovery following coronary occlusion. However, whether short-term exercise can improve cardiac function and hypoxia tolerance ex vivo independent of reperfusion injury and the possible role of calcium channels in improved hypoxia tolerance remains unknown. Therefore, in the current study, heart function was measured ex vivo using the Langendorff method at different oxygen levels after a 4-week voluntary wheel-running regimen in trained and untrained male mice (C57Bl/6NCrl). The levels of cardiac Ca2+-channels: L-type Ca2+-channel (CACNA1C), ryanodine receptor (RyR-2), sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA2), and sodium-calcium exchanger were measured using western blot. Trained mice displayed lower cardiac afterload pressure generation capacity (rate and amplitude), but unaltered hypoxia tolerance when compared to untrained mice with similar heart rates. The level of CACNA1C positively correlated with the pressure generation rate and amplitude. Furthermore, the CACNA1C-RYR-2 ratio also positively correlated with the pressure generation rate. While the 4-week training period was not enough to alter the intrinsic cardiac hypoxia tolerance, interestingly it decreased pressure generation capacity and slowed pressure decreasing capacity in the mouse hearts ex vivo. This reduction in pressure generation rate could be linked to the level of channel proteins in sarcolemmal Ca2+-cycling in trained mice. However, the Ca(2+-)channel levels did not differ significantly between the groups, and thus, the level of calcium channels cannot fully explain all the functional alterations, despite the detected correlations. Therefore, additional studies are warranted to reveal further mechanisms that contribute to the reduced intrinsic capacity for pressure production in trained mouse hearts

Associations Between IFI44L Gene Variants and Rates of Respiratory Tract Infections During Early Childhood

Background. Genetic heterogeneity in type I interferon (IFN)-related gene IFI44L may account for variable susceptibility to respiratory tract infections (RTIs) in children. Methods. In 2 prospective, population-based birth cohorts, the STEPS Study and the FinnBrain Birth Cohort Study, IFI44L genotypes for rs273259 and rs1333969 were determined in relation to the development of RTIs until 1 or 2 years of age, respectively. At age 3 months, whole-blood transcriptional profiles were analyzed and nasal samples were tested for respiratory viruses in a subset of children. Results. In the STEPS Study (n=1135), IFI44L minor/minor gene variants were associated with lower rates of acute otitis media episodes (adjusted incidence rate ratio, 0.77 [95% confidence interval, .61-.96] for rs273259 and 0.74 [.55-.99] for rs1333969) and courses of antibiotics for RTIs (0.76 [.62-.95] and 0.73 [.56-.97], respectively. In the FinnBrain cohort (n=971), IFI44L variants were associated with lower rates of RTIs and courses of antibiotics for RTIs. In respiratory virus-positive 3-month-old children, IFI44L gene variants were associated with decreased expression levels of IFI44L and several other IFN-related genes. Conclusions. Variant forms of IFI44L gene were protective against early-childhood RTIs or acute otitis media, and they attenuated IFN pathway activation by respiratory viruses.Peer reviewe

Kehon kokonaisvaltaisen tutkimisen käsikirjan suomentaminen : The Comprehensive Body Examination (CBE)

Suomensimme opinnäytetyönä The Comprehensive Body Examination (CBE) käsikirjan. Käsikirja on tarkoitettu psykofyysiseen fysioterapiaan perehtyneiden fysioterapeuttien käyttöön. Työ on hyödynnettävissä myös Metropolia Ammattikorkeakoulun psykofyysisen fysioterapian opetuskäytössä. CBE on Berit Heir Bunkanin kehittämä tutkittuun tietoon perustuva kehon tutkimismenetelmä, jonka avulla arvioidaan yksilön voimavaroja. Suomennettu käsikirja sisältää ohjeistuksen CBE-menetelmän käyttöön, termistön ja mittauskaavakkeen. Ohjeistusosuudessa on tekstin lisäksi valokuvia mittausasennoista ja otteista sekä lihaskartat, joista näkyy palpoitavien lihasten sijainti. Mittarikaavakkeeseen sisältyy potilaan taustatietolomake ja tulosten kirjaamiskaavakkeet. Suomenkielisen materiaalin tarkoituksena on helpottaa psykofyysiseen fysioterapiaan tutustumista ja CBE-mittarin käyttöönottoa fysioterapiassa. Termistö voi olla apuna psykofyysisen fysioterapian käsitteiden yhtenäistämisessä ja yhteisen kielen rakentamisessa. Opinnäytetyön tavoitteena on tehdä psykofyysistä fysioterapiaa näkyvämmäksi. Työelämän yhteistyökumppani on Hus Jorvin sairaalan aikuispsykiatrian osasto, jossa käsikirjan aiotaan ottaa käyttöön. Opinnäytetyön osana selvitimme ROBE- tai CBE-menetelmien käyttöä Suomessa. Peijaksen, Jorvin ja Auroran sairaaloiden psykofyysiseen fysioterapiaan perehtynet fysioterapeutit kommentoivat käännöstyötä neljässä tapaamisessa. CBE -menetelmä on standardoitu väline yksilön voimavarojen tutkimiseen ja seurantaan. Jorvin sairaalan aikuispsykiatrisella osastolla on käytössä useita mittareita, jotka eivät ole standardoituja Suomentamamme mittari voisi olla yksi vaihtoehto voimavarojen mittaamisen yhtenäistämisessä.The purpose of our final project was to translate The Comprehensive Body Examination CBE Manual into Finnish. CBE method is an instrument for evaluating and monitoring a person's resources. The manual is intended for physiotherapists who are specialized in psychiatric and psychosomatic physiotherapy. The manual includes instructions to use the method, terminology and examination forms. The manual also includes photographs of examination positions and grips and drawings of the muscles to be palpated. The examination forms include forms for sociological data and for examination result registration. The manual was made to ease the use and introduction of the CBE-method for psychiatric and psychosomatic physiotherapy. The terms can be useful for the future development and standardizing of the language within the area. The partner in cooperation was Hospital Distric of Helsinki and Uusimaa (HUS) Jorvi hospital where we performed our physiotherapy practise in the psychiatric ward. The manual was made in collaboration with the physiotherapists in Jorvi, Peijas and Aurora hospitals

MODULATION OF INNATE IMMUNE RESPONSES AND HOST DEFENSES AGAINST INFECTIONS BY PROPIONATE, SIRTUINS (SIRT 2, 3 AND 5) AND TRAINING

The innate immune system is the first line of defense against invading pathogens. Innate immune cells are classified into subpopulations that show high plasticity to modulate their functions in response to external stimuli. Recently, the reprogramming of innate immune cells has been described to afford protection against infections, a process named “training”. Histone deacetylases (HDACs) form a family of enzymes comprising classical HDACs (HDAC1-11) and sirtuins (SIRT1-7). HDACs regulate metabolic and immunologic pathways. Inhibition of HDACs has a context-dependent effect with reports showing either pro-inflammatory or anti-inflammatory effects. While HDACs share common location and targets, their crosstalk is poorly understood. In this project, we combined different approaches using propionate as an inhibitor of HDACs (HDACi), sirtuin knockout mice and a model of trained immunity to study the modulation of innate immune responses and host defenses. Propionate is a short-chain fatty acid with anti-inflammatory properties produced by the gut microbiota during fiber fermentation. Since inflammatory responses are required to fight pathogens, we tested whether food supplementation with propionate increases susceptibility to infection. Propionate reduced the production of inflammatory cytokines by innate and adaptive immune cells. However, propionate had no effect on the survival of mice in a panel of preclinical models of infections and toxic shock. These observations support the safety of using propionate-based therapies in the treatment of inflammatory diseases without increasing the risk of infections. In the second part, we characterized the innate immune status of mouse lines deficient in SIRT2, SIRT3, SIRT5, SIRT2/3 and SIRT3/5. We show that SIRT2 deficiency increased phagocytosis by macrophages and protected from staphylococcal infection, while SIRT3 and SIRT5 deficiencies had no effect on host susceptibility to infections. SIRT2/3 and SIRT3/5 deficiencies increased cytokine production. SIRT2/3 deficiency reduced glycolysis and protected mice from endotoxemia. SIRT3/5 deficiency increased the production of reactive oxygen species (ROS) and modulated immune cell frequencies in mice with little effect on host responses to infections. Altogether, our results suggest a crosstalk between sirtuins affecting innate immune responses. In the last part, we analyzed the breadth of protection and the cellular mechanisms underlying the protection conferred by trained immunity. We show that training with a fungal cell wall preparation rich in ß-glucan protected from systemic, peritoneal, gastrointestinal and pulmonary infections. Training increased the number of bone marrow and splenic hematopoietic progenitors as well as blood monocytes and neutrophils. In vitro, training increased macrophage effector functions. Thus, training afforded a broad protection by increasing the number and the reactivity of innate immune cells. Overall, our study uncovers crosstalk between sirtuins affecting innate immune responses that should be considered during the development of therapeutic drugs. Moreover, they support the development of drugs to target cells and cellular pathways involved in trained immunity to fight against infectious and inflammatory diseases. -- Le système immunitaire inné représente la première ligne de défense contre l’invasion de pathogènes. Les cellules immunitaires innées expriment des récepteurs leur permettant de reconnaître un grand nombre de structures microbiennes et sont capables de moduler leur fonctionnalité en réponse à des stimuli externes. Des études récentes montrent que la reprogrammation des cellules immunitaires innées, un processus appelé « training », protège des infections. Les déacétylases d’histones (HDACs) forment une famille d’enzymes composée de 18 membres: HDAC1-11 et SIRT1-7. Les HDACs régulent des voies métaboliques et immunologiques. L’inhibition des HDACs induit une réponse pro- inflammatoire ou anti-inflammatoire selon le type de cellule, d’organe et de maladie étudié. Alors que la localisation et les cibles des HDACs se chevauchent, l’interaction entre HDACs est méconnue. Dans ce projet, nous avons étudié l’impact du propionate comme inhibiteur d’HDAC1-11, de déficiences en sirtuines (SIRT) et du training sur la réponse immunitaire innée et les défenses de l’hôte. Le propionate, un acide gras à chaîne courte avec des propriétés anti-inflammatoires, est produit par les bactéries intestinales durant la fermentation de fibres. La réponse inflammatoire étant nécessaire à l’élimination de pathogènes, le propionate pourrait augmenter la susceptibilité aux infections. Dans nos expériences, le propionate inhibait la production de cytokines inflammatoires par les cellules immunitaires innées et adaptatives. Cependant, le propionate n’influençait pas la survie des souris dans des modèles d’infection et de choc toxique. Ces observations suggèrent que des thérapies utilisant du propionate dans le traitement de maladies inflammatoires n’augmentent pas le risque infectieux. Dans la deuxième partie de ce travail, nous avons caractérisé des lignées de souris déficientes en SIRT2, SIRT3, SIRT5, SIRT2/3 et SIRT3/5 en terme de réponse immunitaire innée. Nous avons montré que la déficience en SIRT2 augmentait la phagocytose et protégeait les souris dans un modèle d’infection chronique à Staphylococcus aureus, alors que les déficiences en SIRT3 et SIRT5 n’avaient aucun effet sur la réponse anti-infectieuse. Les déficiences en SIRT2/3 et SIRT3/5 augmentaient la production de cytokines. La déficience en SIRT2/3 réduisait la glycolyse et protégeait de l’endotoxémie. La déficience en SIRT3/5 augmentait la production d’espèces réactives d’oxygène par les mitochondries et modulait les proportions de cellules immunitaires sans influencer la survie dans des modèles d’infection. En résumé, nos résultats montrent une interaction entre sirtuines affectant la réponse immunitaire innée. Dans la dernière partie de cette thèse, nous avons analysé l’ampleur et les mécanismes cellulaires de la protection médiée par le training. Nous avons montré que le training induit par un composé fongique riche en ß-glucan protégeait d’infections systémiques, péritonéale, gastro-intestinale et pulmonaires. Le training augmentait le nombre de progéniteurs hématopoïétiques dans la moelle osseuse et la rate ainsi que de monocytes et neutrophiles dans le sang. In vitro, le training augmentait les fonctions effectrices des macrophages. Par conséquent, la protection induite par le training résulte de l’augmentation du nombre et de la réactivité des cellules immunitaires innées. Dans l’ensemble, nos études révèlent des interactions entre sirtuines influençant la réponse immunitaire innée qu’il est important de considérer lors du développement de médicaments. De plus, nos résultats montrent que les cellules et les voies de signalisation impliquées dans le training sont des cibles intéressantes pour le traitement de maladies infectieuses et inflammatoires

Keskuslaskimokatetrin hoito-opas terveyskeskuksen vuodeosaston hoitohenkilökunnalle

Opinnäytetyön tarkoituksena oli tuottaa vuodeosaston hoitohenkilökunnalle selkeä hoito-opas, jotta hoitohenkilökunta voisi tilanteen vaatiessa kerrata keskuslaskimokatetroidun potilaan hoito-ohjeet ja lisätä osaamistaan keskuslaskimokatetroidun potilaan hoidosta.  Keskuslaskimokatetrin eli cv-katetrin tai sentraalisen laskimokatetrin laitto potilaalle on hyvin yleinen toimenpide. Keskuslaskimokatetri voidaan laittaa päivystyspoliklinikalla tai toimenpideyksikössä. Syitä keskuslaskimon kanyloinnille on useita. Perusterveydenhuollossa keskuslaskimokatetreja ei lähtökohtaisesti aseteta potilaille, mutta keskuslaskimokatetroitujen potilaiden hoitoon tulee kuitenkin olla edellytykset ja osaaminen myös erikoissairaanhoidon ulkopuolella

Bacterial surface properties influence the activity of the TAT-RasGAP317-326 antimicrobial peptide

Antibiotic resistance is an increasing threat for public health, underscoring the need for new antibacterial agents. Antimicrobial peptides (AMPs) represent an alternative to classical antibiotics. TAT-RasGAP317-326 is a recently described AMP effective against a broad range of bacteria, but little is known about the conditions that may influence its activity. Using RNA-sequencing and screening of mutant libraries, we show that Escherichia coli and Pseudomonas aeruginosa respond to TAT-RasGAP317-326 by regulating metabolic and stress response pathways, possibly implicating two-component systems. Our results also indicate that bacterial surface properties, in particular integrity of the lipopolysaccharide layer, influence peptide binding and entry. Finally, we found differences between bacterial species with respect to their rate of resistance emergence against this peptide. Our findings provide the basis for future investigation on the mode of action of TAT-RasGAP317-326, which may help developing antimicrobial treatments based on this peptide

Sirtuin 3 deficiency does not alter host defenses against bacterial and fungal infections

Sirtuin 3 (SIRT3) is the main mitochondrial deacetylase. SIRT3 regulates cell metabolism and redox homeostasis, and protects from aging and age-associated pathologies. SIRT3 may drive both oncogenic and tumor-suppressive effects. SIRT3 deficiency has been reported to promote chronic inflammation-related disorders, but whether SIRT3 impacts on innate immune responses and host defenses against infections remains essentially unknown. This aspect is of primary importance considering the great interest in developing SIRT3-targeted therapies. Using SIRT3 knockout mice, we show that SIRT3 deficiency does not affect immune cell development and microbial ligand-induced proliferation and cytokine production by splenocytes, macrophages and dendritic cells. Going well along with these observations, SIRT3 deficiency has no major impact on cytokine production, bacterial burden and survival of mice subjected to endotoxemia, Escherichia coli peritonitis, Klebsiella pneumoniae pneumonia, listeriosis and candidiasis of diverse severity. These data suggest that SIRT3 is not critical to fight infections and support the safety of SIRT3-directed therapies based on SIRT3 activators or inhibitors for treating metabolic, oncologic and neurodegenerative diseases without putting patients at risk of infection