Usefulness of cefovecin disk‐diffusion test for predicting mecA gene‐containing strains of Staphylococcus pseudintermedius and clinical efficacy of cefovecin in dogs with superficial pyoderma

Background –  Cefovecin has been widely used to treat skin infections in dogs. The relationship of the cefovecin disk‐diffusion test results to the presence of the mecA gene and the clinical efficacy of cefovecin have not been fully evaluated. Hypothesis/Objectives –  To determine the usefulness of an in vitro cefovecin disk‐diffusion test in predicting the presence of the mecA gene in Staphylococcus pseudintermedius, as well as the in vivo efficacy of cefovecin therapy in dogs with superficial pyoderma. Methods –  Twenty‐six S. pseudintermedius strains isolated from 22 dogs with pyoderma were used. In vitro disk‐diffusion test results of cefovecin were compared with agar‐dilution test results, the presence of the mecA gene, and the improvement in clinical scores of dogs with superficial pyoderma at 14 days post treatment. Results –  There was a significant linear correlation (r = ?0.83) between the diameter of the obvious zone of inhibition by disk diffusion and the minimal inhibitory concentration for cefovecin (P < 0.0001). Receiver operating characteristic analysis revealed that zone diameters between 25 and 27 mm exhibited better sensitivity (92.9%) and specificity (100.0%) for detection of strains carrying the mecA gene. The mean improvement in clinical scores in dogs carrying cefovecin‐resistant strains was significantly lower than in dogs carrying cefovecin‐susceptible strains (P < 0.01). Conclusions and clinical importance –  The cefovecin disk‐diffusion test with a cut‐off value estimated in this study was valuable for predicting mecA gene carriage in S. pseudintermedius, as well as the in vivo efficacy of cefovecin therapy in dogs with superficial pyoderma caused by S. pseudintermedius.     

Determination of true absorption and fecal endogenous loss of zinc in goats

We determined the true absorption and endogenous fecal loss of zinc (Zn) in goats using its stable isotope. Three goats were fed with the diet containing 50 mg/kg Zn twice a day for 17 days. In the morning of day 11, the goats were given a meal labeled by ⁶⁷Zn as the tracer with dysprosium as the unabsorbed marker. Then the goats were given unlabeled diet as the rest of the morning feed. We measured dietary and fecal Zn concentration, ⁶⁷Zn abundance and dysprosium concentration in feces. The excretion pattern of the tracer Zn into feces differed from that of dysprosium. Therefore, we directly calculated the true absorption of Zn from Zn concentration and ⁶⁷Zn abundance in fecal samples collected after the labeled diet was given. The apparent absorption of Zn was –0.009 ± 0.016 mg/kg bodyweight (fractional absorption, ?1.07 ± 1.85%). The true absorption of Zn was 0.162 ± 0.018 mg/kg bodyweight (fractional absorption, 18.25 ± 2.01%). The endogenous fecal loss of Zn was 0.172 ± 0.004 mg/kg bodyweight and the intestinal secretion of Zn was 0.210 ± 0.009 mg/kg bodyweight. The present experiment indicates that stable isotopic Zn is a powerful tool for examining Zn metabolism in ruminants.     

Molecular characterization and expression analysis of two Na+/H+ antiporter genes in the marine red alga Porphyra yezoensis

Na⁺/H⁺ antiporters are known to play a crucial role in pH and Na⁺ homeostasis. In the present study, we characterized the molecular structures and expression patterns of two Na⁺/H⁺ antiporters from the marine red alga Porphyra yezoensis (designated PySOS1 and PyNhaD). The full-length cDNAs of PySOS1 and PyNhaD were 5122 and 1804?bp, and contained open reading frames (ORFs) of 4773 and 1275?bp, respectively. The deduced amino acid sequences showed high similarity to SOS1 and NhaD from the higher plant Arabidopsis thaliana. PySOS1 and PyNhaD contained conserved sequences found in the cation?Cproton antiporter. Quantitative real-time PCR analysis revealed that both antiporter genes were expressed in both the gametophyte and sporophyte of P. yezoensis. In addition, mRNA expression of PySOS1 and PyNhaD was simultaneously upregulated by light irradiation, suggesting that coordinated activity between the two is important in pH and Na⁺ homeostasis under light conditions. Moreover, the expression levels of both genes were partially reduced by the photosynthetic inhibitors DCMU and DBMIB, suggesting that upregulation is linked to photosynthesis-related metabolism. These findings provide an initial step towards understanding Na⁺/H⁺ antiporters in marine red algae.     

Effect of temperature,hypoxia and disinfection with ozonated seawater during somitogenesis on muscular development of the trunk in larval seven‐band grouper,Epinephelus septemfasciatus (Thunberg)

The cause of abnormal musculature on both sides of the same myotome in artificially cultured seven‐band grouper Epinephelus septemfasciatus (Thunberg) larvae remains unclear. We evaluated the effect of three factors: changes in temperature (between 22 and 24°C), disinfection with ozonated seawater (0.3 mg TROs L^?1, 1 min), and hypoxia (22 or 14% saturation) during the early (20 h post‐fertilization, hpf) and mid‐ (24 hpf) somite stages on trunk muscular development in larval seven‐band grouper. The thermal regimes and disinfection with ozonated seawater had no effect on muscle development (P > 0.05, G‐test). In contrast, exposure to hypoxia during both the early and mid‐somite stages increased the incidence of abnormal musculature in the trunk (P < 0.01, G‐test). These larvae had abnormal musculature on both sides of the trunk. In addition, the number of abnormal myotomes differed among these larvae. Exposure in the early and mid‐somite stages resulted in the highest frequency of abnormalities in the 11th and 13th myotome respectively. Our results suggest that hypoxia during somitogenesis can lead to abnormal muscle development in the trunk of artificially cultured seven‐band grouper larva.     

Effects of deep percolation on dissolved inorganic nitrogen exports from forested headwater catchments

We examined the effects of deep percolation on dissolved inorganic nitrogen (DIN) exports from two adjacent weathered granite headwater catchments with different deep percolations of water in the Kiryu Experimental Watershed (KEW), Japan. The DIN output in streamflow was estimated from a regression equation between stream discharge and the DIN load, determined from both monthly sampling data and event-based sampling data. The range of deep percolation of DIN was estimated by multiplying observed DIN concentrations in bedrock groundwater by the deep percolation of water estimated from an annual water budget analysis. We found that the deep percolation of DIN corresponded to 34–76 % and ?18 to 8 % of the total DIN output in catchments where the deep percolation of water was 37–45 % and ?6 to 3 % of annual precipitation, respectively. This means that the deep percolation of DIN is not negligible when estimating the total output of DIN in the former catchment. Moreover, the fact that deep percolating water from upper catchments discharged into a lower catchment in KEW suggests that deep percolation of DIN affects downstream N budgets. Therefore, it is important to account for the deep percolation of DIN when evaluating N budgets in forested headwater catchments as well as downstream catchments.     

Effects of salt and low light intensity during the vegetative stage on susceptibility of rice to male sterility induced by chilling stress during the reproductive stage

We tested whether exposing rice plants to abiotic stress (salt or shade) during vegetative growth affects the chilling tolerance of reproductive organs, which is one of the most important traits for rice growing in a cool climate; we used two rice cultivars with different tolerance in two growing seasons. We divided the vegetative growth into three phases to clarify the most sensitive period: 7–22 days after transplanting (DAT), 23–38 DAT and 39–54 DAT. Chilling tolerance of the pre-stressed plants was based on the male sterility induced by low temperatures. Shade and salt stress during all three vegetative growth phases significantly reduced stomatal conductance. Shade decreased the specific leaf weight and the leaf sugar and starch contents, but salt had no significant effect, despite causing leaf damage. Low temperatures during the reproductive stage induced spikelet sterility in all plants, but the magnitude was greater in the salt- and shade-stressed plants of both cultivars, especially those stressed late during vegetative growth. The increased spikelet sterility caused by chilling was closely related to the reduction of the total spikelet number per panicle. This is the first study to show that salt and low light stress during vegetative growth increased the susceptibility of rice plants to chilling damage during panicle development.     

Nutrition During the Early Rearing Period Affects the Incidence of Wooden Breasts in Broilers

This study aimed to evaluate the relationship between early nutrition and the incidence of wooden breasts (WB) in broilers. Sixteen male and twenty female neonatal ROSS 308 broiler chicks were divided equally into four flocks. From 0–12 days of age, starter diet H, composed of 22.4% crude protein (CP), 6.6% crude fat (CF), 1.25% lysine, 0.48% methionine, and ≥3,070 kcal/kg metabolizable energy (ME), was fed to two flocks, and starter diet L, composed of 19.9% CP, 2.5% CF, 1.04% lysine, 0.38% methionine, and ≥2,930 kcal/kg ME, was fed to the remaining two flocks. All the flocks were fed the same commercial finisher diet, composed of 20.3% CP, 7.5% CF, 1.18% lysine, 0.44% methionine, and ≥3,300 kcal/kg ME, from 12–47 days of age. The birds were weighed every 2–5 days, subjected to a wing-lift test, and histology was conducted on the pectoralis major muscle tissue samples from all the birds necropsied at 47 days of age. Significant differences in the mean body weight between groups H and L were observed during 6–16 days and 24–26 days of age in males and during 6–26 days of age in females. Regarding the score evaluation of the individual lesions reflecting wooden breast, the birds in which back-to-back wing contact was not possible had higher lesion scores than those in which back-to-back wing contact was possible. The absence of back-to-back wing contact appeared more frequently in flocks fed the starter diet L, particularly in males. These results indicate that inappropriate nutrition levels in the starter diet increase the incidence of WB. Therefore, avoiding early nutrition deficits is a cost-effective feeding strategy.     

Two allelopathic substances from Paspalum commersonii Lam.

Paspalum commersonii (Poaceae) is a herbaceous perennial weed distributed in the tropics and subtropics regions and grows mainly in the moist, or even flooded soil. It often appears in the rice field as a competitive weed and difficult to manage. Its strong competitive nature indicates possible allelopathic potential of P. commersonii. However, no studies have been found yet on the allelopathic activity of P. commersonii. Thus, we investigated the allelopathic potential of this weed and determined its allelopathic substances. Aqueous methanol extracts of P. commersonii showed concentration-dependent inhibitory activity on the seedling growth of cress, alfalfa, rapeseed, lettuce, barnyard grass, foxtail fescue, Italian ryegrass, and timothy. Two substances were isolated through bioassay-guided fractionation and their structures were determined through spectral data as dehydrovomifoliol and loliolide. Dehydrovomifoliol and loliolide started inhibiting the shoot and root growth of cress at concentrations greater than 3 and 0.03?mM, respectively. The concentrations required for 50% inhibition (I₅₀) of cress shoot and root growth were 3.34 and >3.50?mM for dehydrovomifoliol and 0.04 and 0.05?mM for loliolide, respectively. These results indicate that both substances may affect the inhibitory activity of P. commersonii.