Specific adhesion and invasion of Salmonella Enteritidis in the vagina of laying hens

Salmonella Enteritidis is the predominant serovar associated with egg-borne salmonellosis in humans. The colonization of S. Enteritidis in the vagina may play a role in the production of S. Enteritidis-contaminated eggs. In the first experiment, the in vitro adhesion of S. Enteritidis in vaginal and follicular explants was compared with that of S. Typhimurium by bacteriological isolation methods. The mean number of S. Enteritidis associated with vaginal explants was significantly (P < 0.05) higher than S. Typhimurium associated with vaginal explants and both serovars associated with follicular explants. In the second experiment, the in vitro adhesion and invasion of S. Enteritidis strains in the vaginal epithelium was compared with that of several strains of S. Agona, S. Infantis, S. Hadar, S. Heidelberg, S. Montevideo and S. Typhimurium, by immunohistochemical methods. The mean number of Salmonella in the vaginal epithelium depended on their lipopolysaccharide (LPS) type, with the rank order as follows: LPS type O9 (S. Enteritidis) > LPS type O4 (S. Agona, S. Typhimurium and S. Heidelberg) > LPS type O7 (S. Montevideo and S. Infantis) and LPS type O8 (S. Hadar). This rank order of Salmonella invasiveness is in accordance with the frequency of Salmonella outbreaks involving contaminated eggs. These findings suggest that S. Enteritidis has a higher ability to colonize the vaginal epithelium than other serovars, and the Salmonella LPS type may play an essential role in tropism of the reproductive tract.     

Infestivity of Demodex canis to hamster skin engrafted onto SCID mice

We demonstrated that Demodex canis was transferred to skin xenografts of a dog and a hamster onto severe combined immunodeficiency mice. After the transfer of mites, the number of eggs, larvae, nymphs and adult mites per gram of canine and hamster xenografts increased, whereas no live mites were detected on murine allograft. These results indicate that D. canis proliferates in hair follicles of dog and hamster skins but not in murine allograft. Therefore, D. canis may have host preference but not strict host-specificity.     

Acid Dissolution of Olivines, Feldspars and Dunite

We have treated feldspars (orthoclase, albite, anorthite), JF-1 (a mixture of orthoclase and albite), olivines (fayalite, forsterite) and JP-1 (dunite: an olivine-rich rock) with HNO₃ solution at pH 2 for 10 – 1200 min. The resultant changes in surface composition were assessed by X-ray photoelectron spectroscopy (XPS). The XPS data for fayalite, notably shifts in the Si 2s and O 1s binding energies, indicate preferential dissolution of Fe and formation of a Si-rich surface layer composed of amorphous silica. A Si-rich layer also forms on the surface of the other minerals as the result of acid treatment but the changes in binding energies are relatively small. Forsterite and anorthite dissolved almost congruently in acid solutions, and the Si-rich surface layer is poorly developed. Unlike forsterite, JP-1 shows preferential leaching of Mg relative to Si. Although forsterite is the major constituent of JP-1, this rock also contains some talc and orthopyroxene. These minor mineral constituents appear to influence the behavior of JP-1 in acid solutions. On the other hand, the dissolution and resultant surface alteration of JF-1 were comparable to those of its constituent minerals. The extent of Si-rich surface layer formation followed the order of albite = orthoclase > anorthite for the feldspars, and fayalite > forsterite for the olivines.     

Characterization of Newcastle disease virus isolated from northern pintail (Anas acuta) in Japan

A field isolate of Newcastle disease virus (NDV) isolated from northern pintail (Anas acuta) in Tohoku district, northeast Japan, was characterized. Phylogenetic analysis of the fusion protein indicated that the isolate belonged to genotype I and was closely related to isolates from the Far East corresponded to the migration route for this bird species. The isolate had the typical avirulent cleavage site of the fusion protein (112)GKQGR*L(117). In addition, pathogenicity tests indicated the isolate to have avirulent characteristics. However, the isolate has been shown to cause fusion cytopathic effects and form plaques on chicken embryo fibroblasts (CEF) in the absence of trypsin. The present results suggest that the CEF-adapted NDV, which is avirulent, is circulating among waterfowl populations.     

Isolation of endophytic Frankia from root nodules of Casuarina equisetifolia and infectivity of the isolate to host plants

Abstract

A method which uses the pressure head to predict unsaturated hydraulic conductivity is presented to calculate the soil water flux in a field. Hydraulic conductivities in the primary drying and wetting processes were measured with core samples in the laboratory and the hysteresis between the hydraulic conductivity and pressure head was taken into account. Hydraulic gradients were measured every hour with tensiometers installed in the field. This method was applied to analyze the water movement at 94-cm depth in Hydric Hapludands. Downward or upward flow of water by summing soil water fluxes was examined using the water balance method. Amounts of downward flow determined by our method after heavy rain in a wet soil were slightly larger in the soybean plot but smaller in the bare plot than those obtained by the water balance method due to non-uniform infiltration. Water balance equation which used values of upward flow across a 94-cm depth estimated reasonably well the evapotranspiration from the soybean plot and the evaporation from the bare plot during a dry period. Effect of initial soil water conditions on downward flux by rainfall was well monitored by our method.     

Characterization of stage-specific and cross-reactive antigens from Eimeria acervulina by chicken monoclonal antibodies

The characterization of five chicken monoclonal antibodies (mAbs) that were developed against apical complex antigens of Eimeria acervulina sporozoites is realized and the mAbs reactivity to merozoites belonging to this species is tested. Using immuno-fluorescence assay (IFA), one mAb (HE-4) that recognized apical antigens common to sporozoites of E. acervulina and E. brunetti bound antigens localized on the apical tip of merozoites from all stages of development examined. The mAb 8E-1, reactive with antigens found on the apical tip of all chicken Eimeria sporozoites, also showed binding to antigens common to merozoites from all generations. Another mAb, 8C-3, which identified an antigen shared by sporozoites apical tip and sporocysts wall of E. acervulina reacted very weak and inconstantly with the merozoites from all generations whereas the mAbs 5D-11 and 8D-2 that recognized antigens shared by the sporozoites of E. acervulina and E. maxima (mAb 5D-11) and E. acervulina and E. brunetti (mAb 8D-2) did not react with the merozoites from any generation. Collectively, these results showed that the invasive stages of chicken Eimeria share cross reactive apical complex antigens which are inter-species and inter-generation-specific that might be components of a potential recombinant vaccine.     

Fluconazole decreases cyclosporine dosage in renal transplanted dogs

The effect of fluconazole (Fcz) on the cyclosporine (CsA) dosage was investigated in renal transplanted dogs receiving CsA-based immunosuppressive therapy. Initially, CsA was administered orally twice daily to raise the blood trough level between 400 and 600 ng/ml. After the addition of Fcz, the CsA dosage was adjusted to maintain its therapeutic blood concentration. Fcz significantly decreased CsA dosage in both normal and renal transplanted dogs, but a higher dosage of CsA was needed in renal transplanted dogs. In conclusion, Fcz decreases required CsA dosage and thereby reduces the cost of immunosuppressive therapy in canine renal transplantation.     

Inhibition of hepatitis C virus replication and viral helicase by ethyl acetate extract of the marine feather star Alloeocomatella polycladia

Hepatitis C virus (HCV) is a causative agent of acute and chronic hepatitis, leading to the development of hepatic cirrhosis and hepatocellular carcinoma. We prepared extracts from 61 marine organisms and screened them by an in vitro fluorescence assay targeting the viral helicase (NS3), which plays an important role in HCV replication, to identify effective candidates for anti-HCV agents. An ethyl acetate-soluble fraction of the feather star Alloeocomatella polycladia exhibited the strongest inhibition of NS3 helicase activity, with an IC(50) of 11.7 μg/mL. The extract of A. polycladia inhibited interaction between NS3 and RNA but not ATPase of NS3. Furthermore, the replication of the replicons derived from three HCV strains of genotype 1b in cultured cells was suppressed by the extract with an EC(50) value of 23 to 44 μg/mL, which is similar to the IC(50) value of the NS3 helicase assay. The extract did not induce interferon or inhibit cell growth. These results suggest that the unknown compound(s) included in A. polycladia can inhibit HCV replication by suppressing the helicase activity of HCV NS3. This study may present a new approach toward the development of a novel therapy for chronic hepatitis C.     

Fruiting behavior of dipterocarps in two consecutive episodes of general flowering in a Malaysian lowland rain forest

We examined fruiting behaviors of 24 dipterocarp species in a lowland rain forest of Peninsular Malaysia during two consecutive episodes of general flowering (GF). The first GF episode (GF2001) occurred from August 2001 to February 2002, and the second GF episode (GF2002) followed immediately, from March to September 2002. The magnitude of GF2002 was greater than that of GF2001 at the community level. Significant positive size dependence of fruiting behavior at the community level was found in both GF2001 and GF2002, but there was no significant association between the fruiting behaviors in GF2001 and GF2002 except for one species. These results imply that tree size was one of the explanatory factors for fruiting behavior of dipterocarp species, but there was no evidence that adjacent reproduction caused the absence of reproduction and decreased fecundity in the subsequent fruiting event. In contrast, strong spatial aggregation of fruiting trees was found in GF2001, suggesting that external factors may affect fruiting behavior of dipterocarps in a minor GF episode. Among the 12 study species, there were large variations in fruiting behavior, but growth type (e.g., fast-growing or slow-growing) did not simply explain the inter-specific pattern of fruiting behavior. Thus, tree size may account for fruiting behavior of dipterocarps during the consecutive GF episodes through species-specific differences in phonological responses to internal and external conditions.     

Leaf gas exchanges and photosystem efficiency of the holm oak in urban green areas of Florence,Italy

In urban environments, trees are often faced with limiting physical factors at above- and below-ground levels. These factors include poor air quality, and water and soil pollution that may differ substantially from the natural environment. While numerous studies on urban climate and floristic analyses have been published, studies on the physiological performance and growth of trees in urban sites are rather scarce. They are often in contradiction with the general opinion of the growth's constraint. Generally, it is recognized that urban soils are made of poor landfill materials hampering soil water retention. Often, the soil is sealed by asphalted surfaces that prevent rain infiltration. Nevertheless, there is a gap of information to support the hypothesis by which such conditions determine plant water stress. This study will analyze the water relations and the performance of photosynthesis of Quercus ilex exemplars growing in three different conditions of urban green areas (urban park, outskirt/countryside and urban road) in the city of Florence (Italy) conducted in the year 2002. Results have evidenced a decline in photosynthetic rate in all three sites but a certain capacity of Q. ilex to acclimate to the harsh conditions of urban roads in terms of water relations, tissue elasticity and in photosystem efficiency that was higher at the beginning of summer.