Susceptibility of pandemic influenza virus A 2009 H1N1 and highly pathogenic avian influenza virus A H5N1 to antiinfluenza agents in cell culture

The data on cytotoxicity and antiviral activity of commercial antivirals, such as Remantadine, Oseltamivir, Arbidol and Ribavirin in the MDCK cell culture infected with highly pathogenic (H5N1) and pandemic 2009 (H1N1) influenza A viruses are presented. The study of the antiviral activity of antivirals in the MDCK cells culture demonstrated that Arbidol, Rimantadine and Ribavirin efficiently inhibited reproduction of the highly pathogenic H5N1 influenza viruses isolated from sick birds. Arbidol and Oseltamivir carboxylate selectively inhibited reproduction of the pandemic 2009 H1N1 influenza A viruses with changed specificity to the cell receptors, causing severe influenza in men, while remantadine had no effect on their reproduction.     

Molecular genetic characteristics of the Newcastle Sterna/Astrakhan/Z275/2001 virus isolated in Russia

The genome of the NDV strain Sterna/Astrakhan/2755/2001 isolated from a wild bird of the Volga River delta in 2001 was completely sequenced. The phylogenetic analysis of the strain investigated and other NDV strains clearly demonstrated that Sterna/Astrakhan/2755/ 2001 belonged to the lineage 5b. Comparative analysis of molecular genetic markers of pathogenicity of strain Sterna/Astrakhan/2755/ 2001 allows its velogenic character to be suggested.     

Proteome of the phytopathogen <Emphasis Type="Italic">Xanthomonas citri</Emphasis> subsp. <Emphasis Type="Italic">citri</Emphasis>: a global expression profile

Background  

Citrus canker is a disease caused by Xantomonas citri subsp.citri (Xac), and has emerged as one of the major threats to the worldwide citrus crop because it affects all commercial citrus varieties, decreases the production and quality of the fruits and can spread rapidly in citrus growing areas. In this work, the first proteome of Xac was analyzed using two methodologies, two-dimensional liquid chromatography (2D LC) and tandem mass spectrometry (MS/MS).     

Effects of deer,mice and dwarf bamboo on the emergence,survival and growth of <Emphasis Type="Italic">Abies homolepis</Emphasis> (Piceaceae) seedlings

In the subalpine mixed forest of Mt. Ôdaigahara, mid-western Japan, the understory is dominated by dwarf bamboo (Sasa nipponica), which is the major forage of overly populous sika deer (Cervus nippon). In the present study, we monitored the survival and growth of Abies homolepis seedlings over 5years to determine how they responded to the experimental removal of dwarf bamboo and to the exclusion of sika deer and mice (Apodemus argenteus and A.speciosus). Deer and dwarf bamboo reduced the survival of seedlings but had different effects on growth. The stems of seedlings were shorter in the presence of deer, indicating that taller seedlings were apt to be browsed by deer, whereas the diameters of seedlings were smaller in the presence of dwarf bamboo, mainly owing to its shading effect. The presence of mice decreased the number of seedlings germinating in a particular site, but had no effect on seedling survival after germination. There was no significant indirect effect whereby the survival of seedlings was predicted to be facilitated by the decreased biomass of bamboo because of grazing by deer. We supposed that this might be because the direct negative effect of deer was so large as to conceal the positive indirect effect.     

New genes of Xanthomonas citri subsp. citri involved in pathogenesis and adaptation revealed by a transposon-based mutant library

Background  

Citrus canker is a disease caused by the phytopathogens Xanthomonas citri subsp. citri, Xanthomonas fuscans subsp. aurantifolli and Xanthomonas alfalfae subsp. citrumelonis. The first of the three species, which causes citrus bacterial canker type A, is the most widely spread and severe, attacking all citrus species. In Brazil, this species is the most important, being found in practically all areas where citrus canker has been detected. Like most phytobacterioses, there is no efficient way to control citrus canker. Considering the importance of the disease worldwide, investigation is needed to accurately detect which genes are related to the pathogen-host adaptation process and which are associated with pathogenesis.     

Escape flights of yellowhammers and greenfinches: more than just physics

Wintering birds increase their fat reserves throughout the day, and impaired escape performance is often considered to be an important cost of fat reserves. Since lifting a larger mass requires more energy, if birds escape at maximum power output, an increase in mass will impair the escape flight. In this study we did not find support for mass-dependent escape performance for yellowhammers, Emberiza citrinella, and greenfinches, Carduelis chloris, with natural daily mass increases of 7-8%. This suggests either that the birds were not performing at maximum output at dawn, when light, or that maximum power output was higher at dusk, when heavy. Either way, the birds seemed to be able to put more effort into their escape flight when heavier. In both species, when alarmed, birds took off significantly faster and at a steeper angle than when not alarmed. Yellowhammers escaped at a higher speed and angle than greenfinches, and reacted faster to the predator model. This suggests that predator escape is more than just Newtonian physics, and may be influenced by behavioural, as well as morphological, adjustments. Different species may have evolved different responses to predation risk. Our results seem to be in disagreement with recent ideas about mass-dependent predation risk. However, to build up reserves, birds have to increase exposure time, which increases predation risk. This cost may be more important than impaired escape performance when relatively small, daily, changes in body mass are considered. Copyright 2000 The Association for the Study of Animal Behaviour.