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91.
92.
Suzanne Humphrey Lizeth Lacharme-Lora Gemma Chaloner Kirsty Gibbs Tom Humphrey Nicola Williams Paul Wigley 《PloS one》2015,10(10)
Although Campylobacter is the leading cause of bacterial foodborne gastroenteritis in the world and the importance of poultry as a source of infection is well understood we know relatively little about its infection biology in the broiler chicken. Much of what we know about the biology of Campylobacter jejuni is based on infection of inbred or SPF laboratory lines of chickens with a small number of isolates used in most laboratory studies. Recently we have shown that both the host response and microbial ecology of C. jejuni in the broiler chicken varies with both the host-type and significantly between C. jejuni isolates. Here we describe heterogeneity in infection within a panel of C. jejuni isolates in two broiler chicken breeds, human intestinal epithelial cells and the Galleria insect model of virulence. All C. jejuni isolates colonised the chicken caeca, though colonisation of other parts of the gastrointestinal tract varied between isolates. Extra-intestinal spread to the liver varied between isolates and bird breed but a poultry isolate 13126 (sequence type 21) showed the greatest levels of extra-intestinal spread to the liver in both broiler breeds with over 70% of birds of the fast growing breed and 50% of the slower growing breed having C. jejuni in their livers. Crucially 13126 is significantly more invasive than other isolates in human intestinal epithelial cells and gave the highest mortality in the Galleria infection model. Taken together our findings suggest that not only is there considerable heterogeneity in the infection biology of C. jejuni in avian, mammalian and alternative models, but that some isolates have an invasive and virulent phenotype. Isolates with an invasive phenotype would pose a significant risk and increased difficulty in control in chicken production and coupled with the virulent phenotype seen in 13126 could be an increased risk to public health. 相似文献
93.
Continuous removal of endocrine disruptors by versatile peroxidase using a two‐stage system
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Roberto Taboada‐Puig Thelmo A. Lu‐Chau Gemma Eibes Gumersindo Feijoo Maria T. Moreira Juan M. Lema 《Biotechnology progress》2015,31(4):908-916
The oxidant Mn3+‐malonate, generated by the ligninolytic enzyme versatile peroxidase in a two‐stage system, was used for the continuous removal of endocrine disrupting compounds (EDCs) from synthetic and real wastewaters. One plasticizer (bisphenol‐A), one bactericide (triclosan) and three estrogenic compounds (estrone, 17β‐estradiol, and 17α‐ethinylestradiol) were removed from wastewater at degradation rates in the range of 28–58 µg/L·min, with low enzyme inactivation. First, the optimization of three main parameters affecting the generation of Mn3+‐malonate (hydraulic retention time as well as Na‐malonate and H2O2 feeding rates) was conducted following a response surface methodology (RSM). Under optimal conditions, the degradation of the EDCs was proven at high (1.3–8.8 mg/L) and environmental (1.2–6.1 µg/L) concentrations. Finally, when the two‐stage system was compared with a conventional enzymatic membrane reactor (EMR) using the same enzyme, a 14‐fold increase of the removal efficiency was observed. At the same time, operational problems found during EDCs removal in the EMR system (e.g., clogging of the membrane and enzyme inactivation) were avoided by physically separating the stages of complex formation and pollutant oxidation, allowing the system to be operated for a longer period (~8 h). This study demonstrates the feasibility of the two‐stage enzymatic system for removing EDCs both at high and environmental concentrations. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:908–916, 2015 相似文献
94.
Wheat is the most important cereal grown in the European Union and Spain is its fifth largest wheat producer. There is little information about Fusarium species associated with wheat in Spain. Phylogenetic diversity of 51 strains belonging to Fusarium incarnatum-equiseti species complex (FIESC) isolated from Spanish wheat was investigated using partial sequences of the translation elongation factor gene (EF-1α). Maximum-parsimony and Bayesian analysis of aligned DNA sequences resolved 18 haplotypes and 7 phylogenetic species. Strains morphologically identified as F. equiseti belonged to two different phylogenetic species, FIESC-5 and FIESC-14. Some correlation between phylogenetic species and geographical region was found. The present results highlight the potential contribution of FIESC to the mycotoxin contamination of Spanish wheat. 相似文献
95.
96.
Ming Tang Gemma Comellas Leonard J. Mueller Chad M. Rienstra 《Journal of biomolecular NMR》2010,48(2):103-111
High resolution 13C-detected solid-state NMR spectra of the deuterated beta-1 immunoglobulin binding domain of the protein G (GB1) have been
collected to show that all 15N, 13C′, 13Cα and 13Cβ sites are resolved in 13C–13C and 15N–13C spectra, with significant improvement in T
2 relaxation times and resolution at high magnetic field (750 MHz). The comparison of echo T
2 values between deuterated and protonated GB1 at various spinning rates and under different decoupling schemes indicates that
13Cα T
2′ times increase by almost a factor of two upon deuteration at all spinning rates and under moderate decoupling strength,
and thus the deuteration enables application of scalar-based correlation experiments that are challenging from the standpoint
of transverse relaxation, with moderate proton decoupling. Additionally, deuteration in large proteins is a useful strategy
to selectively detect polar residues that are often important for protein function and protein–protein interactions. 相似文献
97.
The identification of a series of novel, soluble non-peptidic neuropeptide Y Y2 receptor antagonists
Lunniss GE Barnes AA Barton N Biagetti M Bianchi F Blowers SM Caberlotto LL Emmons A Holmes IP Montanari D Norris R Puckey GV Walters DJ Watson SP Willis J 《Bioorganic & medicinal chemistry letters》2010,20(24):7341-7344
The identification and subsequent optimisation of a selective non-peptidic NPY Y2 antagonist series is described. This led to the development of amine 2, a selective, soluble NPY Y2 receptor antagonist with enhanced CNS exposure. 相似文献
98.
99.
The flowers of several families of seed plants warm themselves when they bloom. In some species, thermogenesis is regulated,
increasing the rate of respiration at lower ambient temperature (T
a) to maintain a somewhat stable floral temperature (T
f). The precision of this regulation is usually measured by plotting T
f over T
a. However, such measurements are influenced by environmental conditions, including wind speed, humidity, radiation, etc. This
study eliminates environmental effects by experimentally ‘clamping’ T
f at constant, selected levels and then measuring stabilized respiration rate. Regulating flowers show decreasing respiration
with rising T
f (Q
10 < 1). Q
10 therefore becomes a measure of the biochemical ‘precision’ of temperature regulation: lower Q
10 values indicate greater sensitivity of respiration to T
f and a narrower range of regulated temperatures. At the lower end of the regulated range, respiration is maximal, and further
decreases in floral temperature cause heat production to diminish. Below a certain tissue temperature (‘switching temperature’),
heat loss always exceeds heat production, so thermoregulation becomes impossible. This study compared three species of thermoregulatory
flowers with distinct values of precision and switching temperature. Precision was highest in Nelumbo nucifera (Q
10 = 0.16) moderate in Symplocarpus renifolius (Q
10 = 0.48) and low in Dracunculus vulgaris (Q
10 = 0.74). Switching temperatures were approximately 30, 15 and 20°C, respectively. There were no relationships between precision,
switching temperature or maximum respiration rate. High precision reveals a powerful inhibitory mechanism that overwhelms
the tendency of temperature to increase respiration. Variability in the shape and position of the respiration–temperature
curves must be accounted for in any explanation of the control of respiration in thermoregulatory flowers. 相似文献
100.