Variation in hemolytic activity of Brachyspira hyodysenteriae strains from pigs

Brachyspira hyodysenteriae is the primary cause of swine dysentery, which is responsible for major economic losses to the pig industry worldwide. The hemolytic activity of 10 B. hyodysenteriae strains isolated from stools of pigs with mild to mucohemorrhagic diarrhea was compared and seven hemolysis associated genes were sequenced. Hemolysis induced by these strains varied from strong to near absent. One weakly hemolytic B. hyodysenteriae strain showed sequence changes in five hemolysis associated genes (tlyA, tlyB, hemolysin III, hemolysin activation protein and hemolysin III channel protein) resulting in amino acid substitutions. The occurrence of weakly hemolytic strains identifiable as B. hyodysenteriae should be taken into account in swine dysentery diagnostics. The presence of these strains may affect herd dysentery status, with great impact on a farms trading opportunities

In vitro sensitivity of poultry Brachyspira isolates to essential oil components and in vivo reduction of Brachyspira intermedia in rearing pullets with cinnamaldehyde feed supplementation

Cecal enteritis due to Brachyspira infections tends to be chronic in laying hens. Limited availability of antimicrobial drugs for use in laying hens emphasizes the need for alternative control measures. A broth microdilution method was used to determine the antimicrobial susceptibility of 20 Brachyspira intermedia field isolates from laying hen flocks to components of essential oils (EO). Minimal inhibitory concentration (MIC) distributions, obtained for eight EO components, were all monomodal. Cinnamaldehyde had the lowest MIC values (40-80 mg/l), followed by nerolidol, capsaicin, carvacrol and thymol (80-320 mg/l), eugenol (160-640 mg/l) and linalool (320-1280 mg/l). The MIC ranges of piperine were mostly above the test-range of 1280 mg/l. In an in vivo experiment, coated cinnamaldehyde was supplemented to the feed of rearing pullets. A completely randomized experimental design with 4 treatments and 3 replicates each (replicate = group of 7 one-day-old birds) was applied. The negative and positive control birds received a conventional feed during the whole trial. The positive control group was orally inoculated on 3 consecutive days (day 22, 23 and 24) with 1 ml 1.0 x 108 cfu/ml of a B. intermedia field isolate. Two treatment groups (preventive and curative), identically inoculated, were fed the coated cinnamaldehyde supplemented feed (final cinnamaldehyde concentration in the feed of 500 ppm), the preventive group from day 1 and the curative from day 25. On day 32, ceca were collected for bacteriologic B. intermedia enumeration. The number of Brachyspirapositive birds and the mean enumeration of Brachyspira cells was decreased (P < 0.05) in the curative treated group versus the positive control group. The in vitro results of the present study demonstrate the potential of EO components as antimicrobials against poultry Brachyspira isolates, including isolates with acquired resistance for classic antimicrobial drugs. Reduction of Brachyspira colonization in young pullets was obtained, on a curative way, in an in vivo study using feed supplemented with coated cinnamaldehyde. Further studies are necessary to investigate the mode of action of the coated cinnamaldehyde in reducing Brachyspira colonization of the ceca

How education can be leveraged to foster adolescents’ nature connection

Scientific research on the relationship between nature and health/wellbeing has increased dramatically in recent years. Contact with nature during childhood, both within formal and informal learning contexts, has diverse demonstrated positive effects on young people. In this chapter, we present the results of an interdisciplinary systematic literature review that brings together key insights on the relevance of outdoor leaning from the health and education sciences perspectives. Research highlights the outdoors as an important context for learning with great potential for increased motivation in students. Empirical evidence also supports that contact with nature positively effects students’ performance and school well-being. Moreover, literature also clearly demonstrates that learning in and about nature holds great potential for stimulating nature connection among young people. By extension, it can contribute to long-term and intrinsic motivation among citizens to take up a commitment to protect and conserve (local) nature. Nature connection is a known predictor of sustainable environmental behavior inside and outside of school, as well as later in life. Studies also report on positive health effects of nature contact. Many studies point toward mental health, stress reduction, and ability to concentrate in particular. There is growing evidence that exposure to nature during childhood can positively influence cognitive development and mental health, ranging from emotional and behavioral effects to reduced risk of mental health problems later in life. Because of the health and educational benefits, residential green space is receiving more and more attention, also when it comes to health inequality: unequal access to or proximity of green space in the residential or learning environment can contribute to health inequality. This means that attention in education to nature contact can make an important contribution to counteracting health inequalities among young people. Natural environments provide children with unique opportunities to develop themselves and feel better mentally, with positive effects on school performance, endorsing the potential importance of green playgrounds for students’ mental well-being. Finally, we will show that the promotion of nature connection during childhood, e.g., through school interventions, can thus contribute to health and well-being at the individual level, but also to a more sustainable society

The levels of Brachyspira hyodysenteriae binding to porcine colonic mucins differ between individuals, and binding is increased to mucins from infected pigs with de novo MUC5AC synthesis

Brachyspira hyodysenteriae colonizes the pig colon, resulting in mucohemorrhagic diarrhea and growth retardation. Fecal mucus is a characteristic feature of swine dysentery; therefore, we investigated how the mucin environment changes in the colon during infection with B. hyodysenteriae and how these changes affect this bacterium's interaction with mucins. We isolated and characterized mucins, the main component of mucus, from the colon of experimentally inoculated and control pigs and investigated B. hyodysenteriae binding to these mucins. Fluorescence microscopy revealed a massive mucus induction and disorganized mucus structure in the colon of pigs with swine dysentery. Quantitative PCR (qPCR) and antibody detection demonstrated that the mucus composition of pigs with swine dysentery was characterized by de novo expression of MUC5AC and increased expression of MUC2 in the colon. Mucins from the colon of inoculated and control pigs were isolated by two steps of isopycnic density gradient centrifugation. The mucin densities of control and inoculated pigs were similar, whereas the mucin quantity was 5-fold higher during infection. The level of B. hyodysenteriae binding to mucins differed between pigs, and there was increased binding to soluble mucins isolated from pigs with swine dysentery. The ability of B. hyodysenteriae to bind, measured in relation to the total mucin contents of mucus in sick versus healthy pigs, increased 7-fold during infection. Together, the results indicate that B. hyodysenteriae binds to carbohydrate structures on the mucins as these differ between individuals. Furthermore, B. hyodysenteriae infection induces changes to the mucus niche which substantially increase the amount of B. hyodysenteriae binding sites in the mucus