Exposure variability of fosfomycin administered to pigs in food or water: Impact of social rank

The objective of this study was to document the effect of social ranking on the internal exposure of pigs to an antibiotic (fosfomycin) administered either in food or in drinking water. Signs of aggression were recorded at the feeder and drinker. The interindividual variability explained by the social rank was even greater when the test antibiotic was given in food despite the fact that the water consumption was less variable than the food intake. The range of plasma concentrations after administration of fosfomycin either in food or drinking water leads to a number of pigs in the treated group being exposed to rather low and highly variable concentrations of fosfomycin and not able to maintain adequate plasma concentrations above the typical minimum inhibitory concentration (MIC). Social rank clearly influences the level of exposure of pigs to fosfomycin both in food and drinking. However, its administration in drinking water is likely to be the best option to optimize antibiotic efficacy.     

Identification of Apoptotic Bodies in Equine Semen

Apoptosis in the testis is required to ensure an efficient spermatogenesis. However, sometimes, defective germ cells that are marked for elimination during this process escape elimination in the testes, giving rise to ejaculates with increased percentages of abnormal and apoptotic spermatozoa and a high percentage of apoptotic bodies. Apoptosis markers in the ejaculate have been associated with low fertility, either in animals or humans. Therefore, the goal of this study was to investigate whether fresh equine semen contains apoptotic bodies [initially named Merocyanine 540 (M540) bodies] and to study the relationship between the quantity of these bodies and cell concentration, the volume of ejaculate, viability and motility. Moreover, we also studied whether the presence apoptotic bodies in fresh semen was related to the resistance of the stallion spermatozoa to being incubated at 37°C or being frozen and thawed. Fresh equine semen was stained with fluorescent dyes such as M540 and Annexin‐V. Active Caspase 3 was studied in fresh semen through Western blotting and immunofluorescence with a specific antibody. Sperm kinematics was assessed in fresh, incubated and thawed samples using computer‐assisted semen analysis, and viability was evaluated with the LIVE/DEAD Sperm Viability Kit. Overall, our results demonstrate for the first time the presence of apoptotic bodies in equine semen. The quantity of apoptotic bodies was highly variable among stallions and was positively correlated with Caspase 3 activity in fresh samples and negatively correlated with the viability and motility of stallion spermatozoa after the cryopreservation process.     

Anti‐Mullerian Hormone Concentration and Antral Ovarian Follicle Population in Murrah Heifers Compared to Holstein and Gyr Kept Under the Same Management

This study was performed to evaluate plasma concentrations of anti‐Mullerian hormone (AMH) and the ovarian antral follicle population (AFP) in different genetic groups. Cyclic heifers (13 Bubalus bubalis [Murrah]; 15 Bos taurus [Holstein] and 10 Bos indicus [Gyr]) were maintained under the same management and were synchronized with two doses of 150 μg IM d‐cloprostenol administered 14 days apart. After the second d‐cloprostenol treatment, heifers had their ovaries scanned daily by ultrasound to define the day of ovulation. On the same day, the AFP was determined and a plasma sample was collected to measure AMH. Murrah heifers had less AFP (25.6 ± 2.1 follicles; p = 0.01) and plasma AMH concentration (0.18 ± 0.03 ng/ml; p < 0.001) than Gyr (60.0 ± 12.2 follicles and 0.60 ± 0.12 ng/ml of AMH); however, data were similar when compared to Holstein (35.9 ± 6.8 follicles and 0.24 ± 0.06 ng/ml of AMH) heifers. Regardless of genetic background, there was a positive relationship between the AFP and plasmatic AMH concentration (Murrah [r = 0.62; p < 0.01], Holstein [r = 0.66; p < 0.001] and Gyr [r = 0.88; p < 0.001]). Also, when heifers were classified according to high‐ or low‐AMH concentration based on the average within each genetic group, high‐AMH heifers had greater (p < 0.0001) AFP than low‐AMH heifers. In conclusion, both Murrah and Holstein heifers presented lower plasma AMH concentration and AFP when compared to Gyr.     

Reconstruction of Current Flow and Imaging of Current-Limiting Defects in Polycrystalline Superconducting Films

Magneto-optical imaging was used to visualize the inhomogeneous penetration of magnetic flux into polycrystalline TlBa2Ca2Cu3Ox films with high critical current densities, to reconstruct the local two-dimensional supercurrent flow patterns and to correlate inhomogeneities in this flow with the local crystallographic misorientation. The films have almost perfect c-axis alignment and considerable local a- and b-axis texture because the grains tend to form colonies with only slightly misaligned a and b axes. Current flows freely over these low-angle grain boundaries but is strongly reduced at intermittent colony boundaries of high misorientation. The local (<10-micrometer scale) critical current density Jc varies widely, being up to 10 times as great as the transport Jc (scale of approximately 1 millimeter), which itself varies by a factor of about 5 in different sections of the film. The combined experiments show that the magnitude of the transport Jc is largely determined by a few high-angle boundaries.     

Antifungal chalcones and new caffeic acid esters from Zuccagnia punctata acting against soybean infecting fungi

The crude methanolic extract of Zuccagnia punctata was active toward the fungal pathogens of soybean Phomopsis longicolla and Colletotrichum truncatum. Assay guided fractionation led to the isolation of two chalcones, one flavanone and a new caffeoyl ester derivative as the compounds responsible for the antifungal activity. Another new caffeoyl ester derivative was isolated from the antifungal chloroform extract but proved to be inactive against the soybean infecting fungi up to 50 microg/mL     

Coastal geomorphology and oceanographic features shape subtidal benthic communities in management areas of central Chile

1. The spatial variation in community structure among 30 areas for the management and exploitation of benthic resources (AMEBRs) in central Chile was assessed from surveys conducted during the same spring–summer season. One hundred taxa identified in the subtidal surveys were grouped into 10 functional groups.
2. The influence and relative importance of external factors over benthic associations were assessed through nonmetric multidimensional scaling (NMDS) and path analysis. Three main categories of external factors were considered: ‘terrain traits’ (e.g. coastline exposure), ‘surface-ocean conditions’ (e.g. sea surface temperature, SST), and ‘fishery-related variables’ (e.g. cumulative landings).
3. The NMDS revealed a strong association between benthic community structure and both terrain and surface-ocean conditions (42% of variance explained by permutational multivariate analysis of variance), but not with fishery-related variables. Assemblages typical of rocky substrates were associated with larger seasonal fluctuations in SST and surface chlorophyll a. The presence of soft-bottom functional groups was associated with higher levels of surface fluorescence and larger seasonal fluctuations in a satellite-derived proxy for river-plume influence (nLw645).
4. A path analysis model for hard-bottom communities reached a 49% goodness of fit (GOF), with the presence of epifaunal filter-feeders, grazers, predators, and scavengers being significantly correlated with leathery and corticated foliose algae, which in turn depend on the fraction of rocky substrate in the AMEBR; the fraction of rocky substrate is positively correlated with coastline exposure.
5. The model for soft-bottom communities reached a 52% GOF with the presence of infaunal filter-feeders and epifaunal detritivores depending directly on SST and surface chlorophyll a. The fishery-related variables considered in the model had no apparent effect on the structure of either type of subtidal community.
6. These results provide a hierarchy of physical–biological associations determining the functional composition of subtidal benthic communities in management areas along central Chile. This knowledge may improve future assessments of ecosystem response to changes in environmental conditions and management strategies.

     

Plasma concentrations resulting from florfenicol preparations given to pigs in their drinking water

Florfenicol administered through the drinking water has been recommended as a metaphylactic antibacterial drug to control outbreaks of respiratory diseases in pigs caused by strains of Actinobacillus pleuropneumoniae and Pasteurella multocida, yet it is difficult to pinpoint in practice when the drug is given metaphylactically or therapeutically. Further, pigs are likely to reject florfenicol-medicated water, and plasma concentrations of the drug are likely to be marginal for diseases caused by Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus. The reported minimal inhibitory concentration (MIC) values for these organisms show a breakpoint of 2 to 3 μg/mL. An experiment was conducted during September and October 2009. One hundred twenty healthy crossbred pigs (Landrace-Yorkshire), weighing 23 ± 6.2 kg, were used in this trial. They were randomly assigned to 5 groups, with 3 replicates of 8 animals/group. Two commercial preparations of florfenicol were administered through the drinking water at 2 concentrations (0.01 and 0.015%). Water intake was measured before and after medication, and plasma concentrations of florfenicol were determined by HPLC. Considerable rejection of florfenicol-medicated water was observed. However, plasma florfenicol concentrations were of a range sufficient for a methaphylaxis approach to preventing disease by bacteria, with MIC breakpoints of ≤ 0.25 μg/mL. Decreased efficacy as a metaphylactic medication should be expected for bacteria with MIC >0.25 μg/mL, considering the reported existence of bacteria resistant to florfenicol and the natural resistance of Streptococcus suis or E. coli to this drug.     

Effect of Different Extenders and Seminal Plasma on the Susceptibility of Equine Spermatozoa to Lipid Peroxidation After Single-Layer Centrifugation, Through Androcoll-E

This study was conducted in an attempt to see whether single-layer centrifugation (SLC) increases the susceptibility of stallion spermatozoa to lipid peroxidation (LPO), in different extenders after removing all seminal plasma (SP). The susceptibility of stallion spermatozoa to LPO was studied before and after SLC. Each ejaculate was split, and aliquots extended with one of the three different extenders: INRA 96, Kenney's, or Equipro, and stored for 24 hours at 5°C (i). From the extended samples, an aliquot was kept as a control and the other was subjected to SLC through Androcoll-E. The selected spermatozoa were re-suspended in the appropriate extenders, without (ii) or with (iii) addition of 50% (v/v) pooled homologous SP for 24 hours at 5°C. Using ferrous sulfate as pro-oxidant, the susceptibility for LPO was flow-cytometrically assessed using the probe Bodipy^581/591-C₁₁. Sperm motility, monitored with a Qualisperm motility analyzer, increased after SLC treatment (P < .001). No significant correlations were found between motility and induced LPO with ferrous sulfate. The SP and extenders, per se, did not have a significant protective effect against LPO, but the interaction between SP and Kenney increased the susceptibility to LPO. However, the selected spermatozoa through Androcoll-E and the subsequent dilution in INRA had a significant protective effect against LPO (P < .05), especially when the oxidative insults were higher (80 μM).