Impact of latent infections with Chlamydophila species in young cattle

To assess long-term effects of naturally occurring infection with Chlamydophila spp. on animal health, 25 calves were grouped according to their chlamydial carrier status and checked for health parameters from 2 to 7 months of age. Monthly PCR testing revealed persistent or frequently recurring infections with Chlamydophila pecorum and Chlamydophila abortus in Group 2 (Chl+, n=13), but not in Group 1 (Chl-, n=12). Despite the absence of any clinical illness, calves in Group 2 showed significantly higher body temperatures (subfebrile), lower bodyweights, reduced serum iron concentrations, lower total haemoglobin and haematocrit values. Counting and flow cytometric differentiation of peripheral white blood cells revealed a general decrease in leukocytes in Group 2. At necropsy, follicular bronchiolitis was found in 10/13 calves in Group 2 but in none of Group 1, and the weight of pharyngeal tonsils was significantly higher in Group 2. In conclusion, naturally occurring infections with Chlamydophila species in calves were found to be associated with chronic effects on animal health at a subclinical level.     

Gene expression profiling of porcine mammary epithelial cells after challenge with Escherichia coli and Staphylococcus aureus in vitro

Postpartum Dysgalactia Syndrome (PDS) represents a considerable health problem of postpartum sows, primarily indicated by mastitis and lactation failure. The poorly understood etiology of this multifactorial disease necessitates the use of the porcine mammary epithelial cell (PMEC) model to identify how and to what extent molecular pathogen defense mechanisms prevent bacterial infections at the first cellular barrier of the gland. PMEC were isolated from three lactating sows and challenged with heat-inactivated potential mastitis-causing pathogens Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) for 3 h and 24 h, in vitro. We focused on differential gene expression patterns of PMEC after pathogen challenge in comparison with the untreated control by performing microarray analysis. Our results show that a core innate immune response of PMEC is partly shared by E. coli and S. aureus. But E. coli infection induces much faster and stronger inflammatory response than S. aureus infection. An immediate and strong up-regulation of genes encoding cytokines (IL1A and IL8), chemokines (CCL2, CXCL1, CXCL2, CXCL3, and CXCL6) and cell adhesion molecules (VCAM1, ICAM1, and ITGB3) was explicitly obvious post-challenge with E. coli inducing a rapid recruitment and activation of cells of host defense mediated by IL1B and TNF signaling. In contrast, S. aureus infection rather induces the expression of genes encoding monooxygenases (CYP1A1, CYP3A4, and CYP1B1) initiating processes of detoxification and pathogen elimination. The results indicate that the course of PDS depends on the host recognition of different structural and pathogenic profiles first, which critically determines the extent and effectiveness of cellular immune defense after infection.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-015-0178-z) contains supplementary material, which is available to authorized users.     

Granular convection observed by magnetic resonance imaging

Vibrations in a granular material can spontaneously produce convection rolls reminiscent of those seen in fluids. Magnetic resonance imaging provides a sensitive and noninvasive probe for the detection of these convection currents, which have otherwise been difficult to observe. A magnetic resonance imaging study of convection in a column of poppy seeds yielded data about the detailed shape of the convection rolls and the depth dependence of the convection velocity. The velocity was found to decrease exponentially with depth; a simple model for this behavior is presented here.     

Galileo at Io: results from high-resolution imaging

During late 1999/early 2000, the solid state imaging experiment on the Galileo spacecraft returned more than 100 high-resolution (5 to 500 meters per pixel) images of volcanically active Io. We observed an active lava lake, an active curtain of lava, active lava flows, calderas, mountains, plateaus, and plains. Several of the sulfur dioxide-rich plumes are erupting from distal flows, rather than from the source of silicate lava (caldera or fissure, often with red pyroclastic deposits). Most of the active flows in equatorial regions are being emplaced slowly beneath insulated crust, but rapidly emplaced channelized flows are also found at all latitudes. There is no evidence for high-viscosity lava, but some bright flows may consist of sulfur rather than mafic silicates. The mountains, plateaus, and calderas are strongly influenced by tectonics and gravitational collapse. Sapping channels and scarps suggest that many portions of the upper approximately 1 kilometer are rich in volatiles.     

Long-term elevation of atmospheric CO(2) concentration and the carbon exchange rates of saplings of Pinus taeda L. and Liquidambar styraciflua L

The relationship between carbon exchange rate (CER) and internal CO(2) concentration was measured in leaves of saplings of Liquidambar styraciflua L. (sweetgum) and Pinus taeda L. (loblolly pine) grown from seed for more than 14 months at atmospheric CO(2) concentrations of either 350 or 500 microl l(-1). An elevated concentration of CO(2) during growth reduced CER at any given internal CO(2) concentration in sweetgum, but not in loblolly pine. Stomatal limitation of CER showed little response to concentration of CO(2) during measurement, but was higher in both species when grown at 500 than at 350 microl l(-1) CO(2). The net effect of a long-term increase in CO(2) concentration from 350 to 500 microl l(-1) was an increase in CER of loblolly pine, but a slight decrease in CER of sweetgum. It is suggested that the depression of CER in sweetgum resulted from a reduction in the activity of ribulose-1,5-bisphosphate carboxylase-oxygenase.     

Acetochlor sorption and degradation in limestone subsurface and aquifers

BACKGROUND: Acetochlor, introduced on the market in 1994, is used extensively worldwide, but sorption and degradation studies, including subsurface, are scarce, and there appear to be no such studies with aquifer sediment according to the present mini‐review. Sorption, degradation and mineralisation of acetochlor were investigated in heterogeneous limestone down to 43 m below surface (mbs) in four European aquifers (1.7–59 mbs), both aerobic and anaerobic. RESULTS: Sorption revealed K_d values of 3.39–4.96 L kg^?1 in topsoil, < 0.01–2.02 L kg^?1 in heterogeneous limestone, 0.06–0.72 L kg^?1 in aerobic aquifers and 1.03–4.60 L kg^?1 in microaerobic or anaerobic aquifers. The mineralisation half‐lives in the samples from 0.0–0.6 mbs were 0.8–2.1 years and 4.7–95 years in the unsaturated limestone samples from 1–43 mbs. Out of 22 samples from four different European aquifers, acetochlor was mineralised in five samples (half‐lives of 9–19 years), all from the same aquifer and core section (19.25–19.53 mbs). CONCLUSION: Sorption was weak in limestone and aerobic sandy aquifers, and strong in topsoils and in reduced sandy aquifers. Redox conditions controlled the extent of acetochlor sorption in aquifers, as reduced conditions induced increased sorption. Acetochlor was mineralised in deep subsurface, though slowly, and, as mineralisation is the only true removal mechanism in natural attenuation, even slow mineralisation in aquifers with long residence times can have a significant impact. Copyright © 2010 Society of Chemical Industry     

Evaluation of lung function in pigs either experimentally or naturally infected with Chlamydiaceae

This study evaluated the influence of chlamydial infections on lung function in conventionally raised pigs. Eight pigs aged 39-44 days were included in an aerogeneous challenge model (4 were exposed to Chlamydia suis; 4 served as controls). Nineteen pigs aged 5-27 weeks without clinical symptoms (but partly PCR-positive for chlamydial species) were examined over 6 months. For lung function testing, impulse oscillometry was used. In total, all 27 pigs underwent 465 lung function tests. Variables of ventilation (respiratory rate, tidal volume, minute volume), respiratory impedance (expressed as resistance and reactance within the frequency range 3-15 Hz), and model derived resistance of proximal and distal airways were measured. Experimental exposure to C. suis significantly affected lung function. Early distal airway obstruction (3-5 days after infection) was followed by an obstruction of proximal airways (7 days after infection). The breathing pattern was significantly changed (decreased tidal volume; increased respiratory rate). In symptom-free pigs having a naturally acquired presence of different chlamydial species in the respiratory system, no deterioration in lung function could be determined up to the age of 6 months. In conclusion, the consequences of respiratory chlamydial infections appear to vary from clinical inapparence to severe respiratory distress.     

Evaluation of lung function in pigs either experimentally or naturally infected with Chlamydiaceae

This study evaluated the influence of chlamydial infections on lung function in conventionally raised pigs. Eight pigs aged 39–44 days were included in an aerogeneous challenge model (4 were exposed to Chlamydia suis; 4 served as controls). Nineteen pigs aged 5–27 weeks without clinical symptoms (but partly PCR-positive for chlamydial species) were examined over 6 months. For lung function testing, impulse oscillometry was used. In total, all 27 pigs underwent 465 lung function tests. Variables of ventilation (respiratory rate, tidal volume, minute volume), respiratory impedance (expressed as resistance and reactance within the frequency range 3–15 Hz), and model derived resistance of proximal and distal airways were measured. Experimental exposure to C. suis significantly affected lung function. Early distal airway obstruction (3–5 days after infection) was followed by an obstruction of proximal airways (7 days after infection). The breathing pattern was significantly changed (decreased tidal volume; increased respiratory rate). In symptom-free pigs having a naturally acquired presence of different chlamydial species in the respiratory system, no deterioration in lung function could be determined up to the age of 6 months. In conclusion, the consequences of respiratory chlamydial infections appear to vary from clinical inapparence to severe respiratory distress.