A high prevalence of antimicrobial resistant Escherichia coli isolated from pigs and a low prevalence of antimicrobial resistant E. coli from cattle and sheep in Great Britain at slaughter

The incidence of antimicrobial resistance and expressed and unexpressed resistance genes among commensal Escherichia coli isolated from healthy farm animals at slaughter in Great Britain was investigated. The prevalence of antimicrobial resistance among the isolates varied according to the animal species; of 836 isolates from cattle tested only 5.7% were resistant to one or more antimicrobials, while only 3.0% of 836 isolates from sheep were resistant to one or more agents. However, 92.1% of 2480 isolates from pigs were resistant to at least one antimicrobial. Among isolates from pigs, resistance to some antimicrobials such as tetracycline (78.7%), sulphonamide (66.9%) and streptomycin (37.5%) was found to be common, but relatively rare to other agents such as amikacin (0.1%), ceftazidime (0.1%) and coamoxiclav (0.2%). The isolates had a diverse range of resistance gene profiles, with tet(B), sul2 and strAB identified most frequently. Seven out of 615 isolates investigated carried unexpressed resistance genes. One trimethoprim-susceptible isolate carried a complete dfrA17 gene but lacked a promoter for it. However, in the remaining six streptomycin-susceptible isolates, one of which carried strAB while the others carried aadA, no mutations or deletions in gene or promoter sequences were identified to account for susceptibility. The data indicate that antimicrobial resistance in E. coli of animal origin is due to a broad range of acquired genes.     

Florivores decrease pollinator visitation in a self-incompatible plant

Different biotic interactions may influence one another to produce complex patterns of direct and indirect effects, which together influence plant reproductive success. However, so far most studies on plant-animal interactions have focused on single interactions in isolation. In this study, we studied the effect of florivory by the weevil Cionus nigritarsis on pollinator visitation rate in the self-incompatible perennial herb Verbascum nigrum by combining observations of florivory and pollination in natural populations with records of pollinator visitation to plants with different levels of experimentally inflicted damage.Increasing levels of damage through either natural or simulated florivory resulted in fewer pollinator visits per plant and per flower. As expected, the magnitude of the indirect effect of florivory on pollinator visitation was proportional to the intensity of florivory. Our results indicate that biotic non-pollinating agents, such as florivores, may induce substantial changes in pollinator availability. Therefore, studies addressing different plant-animal interactions in parallel are necessary to better comprehend the factors influencing the reproductive performance and demography of flowering plants.     

Second cancers following the diagnosis of Merkel cell carcinoma: A nationwide cohort study

Merkel cell carcinoma (MCC) is a rare neuroendocrine carcinoma of the skin. MCCs and some other skin cancers, such as basal cell carcinomas, frequently harbour Merkel cell polyomavirus DNA. The purpose of the study was to investigate the frequency of second cancers following the diagnosis of MCC. We studied the incidence of second primary cancers after the diagnosis of MCC from the files of the Finnish Cancer Registry in 1979–2006. Among the 172 MCC patients identified a total of 34 second primary cancers were detected in 30 individuals after the diagnosis of MCC. Female MCC patients were diagnosed with 25 subsequent cancers (SIR, 2.35; 95% CI, 1.52–3.47; p < 0.001) and male patients with 9 cancers (SIR, 2.32, 95% CI, 1.06–4.40; p < 0.05). The MCC patients had an increased risk for a subsequent cancer (any site) compared to age-, gender- and calendar period-matched general population (standardized incidence ratio [SIR] 2.34; 95% confidence interval [CI], 1.62–3.27). The risks for basal cell carcinoma of the skin (O = 11), SIR, 3.48; 95% CI, 1.74–6.22 and chronic lymphocytic leukemia (O = 2), SIR, 17.9; 95% CI, 2.16–64.6 were significantly elevated. The SIRs for an overall second primary cancer risk did not change markedly with time since the diagnosis of MCC. We conclude that patients diagnosed with MCC have an increased risk for a second cancer. This risk may in part result from shared etiological factors between MCC and other tumour types, such as immunosuppression or possibly Merkel cell polyomavirus infection.     

The binding specificity of the marker antibodies Tra-1-60 and Tra-1-81 reveals a novel pluripotency-associated type 1 lactosamine epitope

The expression of the epitopes recognized by the monoclonal antibodies Tra-1-60 and Tra-1-81 is routinely used to assess the pluripotency status of human embryonic stem cells (hESCs) and induced pluripotent stem (iPS) cells. Although it is known that the epitopes recognized by Tra-1-60 and Tra-1-81 are carbohydrates, the exact molecular identity of these epitopes has been unclear. Glycan array analysis with more than 500 oligosaccharide structures revealed specific binding of Tra-1-60 and Tra-1-81 to two molecules containing terminal type 1 lactosamine: Galβ1-3GlcNAcβ1-3Galβ1-4GlcNAc and Galβ1-3GlcNAcβ1-3Galβ1-4GlcNAcβ1-6(Galβ1-3GlcNAcβ1-3)Galβ1-4Glc. The type 1 disaccharide in itself was not sufficient for binding, indicating that the complete epitope requires an extended tetrasaccharide structure where the type 1 disaccharide is β1,3-linked to type 2 lactosamine. Our mass spectrometric analysis complemented with glycosidase digestions of hESC O-glycans indicated the presence of the extended tetrasaccharide epitope on an O-glycan with the likely structure Galβ1-3GlcNAcβ1-3Galβ1-4GlcNAcβ1-6(Galβ1-3)GalNAc. Thus, the present data indicate that the pluripotency marker antibodies Tra-1-60 and Tra-1-81 recognize the minimal epitope Galβ1-3GlcNAcβ1-3Galβ1-4GlcNAc, which is present in hESCs as a part of a mucin-type O-glycan structure. The exact molecular identity of Tra-1-60 and Tra-1-81 is important for the development of improved tools to characterize the pluripotent phenotype.     

Antibiotic resistance in bacteria from magpies (Pica pica) and rabbits (Oryctolagus cuniculus) from west Wales

The prevalence of antibiotic-resistant bacteria in wild animal and bird populations is largely unknown, with little consistency among the few published reports. We therefore examined intestinal bacteria from magpies ( Pica pica ) and rabbits ( Oryctolagus cuniculus ) collected in rural west Wales. Escherichia coli isolates resistant to multiple antibiotics were grown from eight of 20 magpies trapped in spring, 1999 and one of 17 in spring, 2000; the most prevalent resistance trait among these isolates was to tetracycline, but resistances to ampicillin, chloramphenicol, kanamycin, sulphonamide, tetracycline and trimethoprim were also found. Tetracycline-resistant Enterococcus spp. were found in one of 20 magpies in 1999 and three of 17 in 2000. Only one resistant E. coli isolate was detected among gut bacteria from 13 rabbits, and this strain was resistant only to tetracycline. Differences in the prevalence of resistance between bacteria from rabbits and magpies may reflect differences in diet: rabbits graze field edges, whereas magpies are omnivorous and opportunistic. The resistance genes found in E. coli isolates from magpies mostly corresponded to those common among human isolates, but those conferring tetracycline resistance were unique.     

Endozoochory varies with ecological scale and context

Several studies on endozoochory have established large herbivores as important for seed dispersal, yet no studies have evaluated how endozoochory is dependent on ecological scale and context. Here we address effects of reindeer density on endozoochory in a hierarchical, multi-scale study, encompassing several ecological contexts.
We found reindeer density effects on endozoochory to vary with spatial scale. Higher reindeer densities at the level of landscape areas, as indexed through faeces abundance, were related to both less species and lower abundance of emerging plants from faeces. In contrast, there was no effect of higher reindeer densities at the level of herding districts (i.e. large scale assemblages of landscapes). Lack of consistency between scales reflects ecological hierarchy, indicating that reindeer density effects on endozoochory best matches at the scale of landscapes.
Pasture seed plant composition was only partly an important ecological factor. That is, ericoid species, the dominating plants in the pastures, were also the most abundant seed plants found to emerge from the faeces. However, most herbaceous seed plant species in the pastures were not emerging from the faeces and the few that emerged were positively related to the site fertility and altitude of the pasture.
Studies addressing endozoochory of ruminants are typically concerned with seed plants, whereas in this study we also found indications of that diaspores of ferns are viable after passing the digestive tract of large herbivores. Vascular spore plants were even more abundant in the faeces than were vascular seed plants.
Results from this study demonstrate that reindeer may counteract a potentially negative impact on seed limitation from their grazing by returning viable seeds in their faeces. However, in Finnmark, northern Norway, this effect is only marginal, relates only to a very few species and individuals and shows ecological scale and context dependence.     

Stimulation of autophagy by rapamycin protects neurons from remote degeneration after acute focal brain damage

Autophagy is the evolutionarily conserved degradation and recycling of cellular constituents. In mammals, autophagy is implicated in the pathogenesis of many neurodegenerative diseases. However, its involvement in acute brain damage is unknown. This study addresses the function of autophagy in neurodegeneration that has been induced by acute focal cerebellar lesions. We provide morphological, ultrastructural, and biochemical evidence that lesions in a cerebellar hemisphere activate autophagy in axotomized precerebellar neurons. Through time course analyses of the apoptotic cascade, we determined mitochondrial dysfunction to be the early trigger of degeneration. Further, the stimulation of autophagy by rapamycin and the employment of mice with impaired autophagic responses allowed us to demonstrate that autophagy protects from damage promoting functional recovery. These findings have therapeutic significance, demonstrating the potential of pro-autophagy treatments for acute brain pathologies, such as stroke and brain trauma.     

Improved cider fermentation performance and quality with newly generated <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> × <Emphasis Type="Italic">Saccharomyces eubayanus</Emphasis> hybrids

Yeast cryotolerance may be advantageous for cider making, where low temperatures are usually employed. Here, we crossed the cryotolerant S. eubayanus with a S. cerevisiae wine strain and assessed the suitability of the hybrids for low-temperature cider fermentation. All strains fermented the juice to 5% ABV, but at different rates; hybrid strains outperformed S. cerevisiae, which was sensitive to low temperatures. The best hybrid fermented similarly to S. eubayanus. S. eubayanus produced sulphurous off flavours which masked a high concentration of fruity ester notes. This phenotype was absent in the hybrid strains, resulting in distinctly fruitier ciders. Aroma was assessed by an independent consumer panel, which rated the hybrid ciders as identical to the wine strain cider. Both were significantly more pleasant than the S. eubayanus cider. Interspecific hybridization can apparently be used effectively to improve low-temperature fermentation performance without compromising product quality.     

Seed number and environmental conditions do not explain seed size variability for the invasive herb Lupinus polyphyllus

Intraspecific variation in seed size may result from life-history constraints or environmental conditions experienced. This variation in seed size is likely to affect the early stage of invasion as seed size may contribute to the success or failure of population establishment. However, only a few studies have examined seed size variability and its causes and consequences for invaders so far. Using the invasive herb Lupinus polyphyllus, we estimated seed mass variation within and among 39 populations from two different geographic regions in a part of the invaded range. We empirically and experimentally evaluated the effect of seed number and environmental conditions (e.g. geographic region, habitat type, intraspecific competition) on seed mass, emergence and seedling performance. Seed mass varied threefold, being largest among individual plants within populations and smallest among populations. Variation in seed mass was neither related to seed number nor the environmental conditions examined, but led to differences in offspring performance, with emergence and seedling size increasing with seed mass. Larger L. polyphyllus seeds were better establishers than smaller seeds regardless of environmental conditions, indicating that the success of L. polyphyllus invasions is likely to depend positively on seed mass. Our results suggest that some plant species such as the invasive L. polyphyllus may not show an adaptive response in seed mass to resources or environmental conditions, which may partly explain their ability to colonise a range of different habitats.