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171.
In contemporary Aotearoa/New Zealand, Maori indigenous claims to fisheries have resulted in an uneasy compromise in which private property in fisheries coexists with an important element of common ownership. Individual Transferable Quotas and the bundle of rights encoded in Customary Fisheries Regulations are the expression of this compromise. At the legal level, these reflect the major property paradigms of private and communal. In practice, neither has accommodated Maori concrete relations of owning, and social practices of exchanging, fish.  相似文献   
172.
The hypolithic microbial community associated with quartz pavement at a high-altitude tundra location in central Tibet is described. A small-scale ecological survey indicated that 36% of quartz rocks were colonized. Community profiling using terminal restriction fragment length polymorphism revealed no significant difference in community structure among a number of colonized rocks. Real-time quantitative PCR and phylogenetic analysis of environmental phylotypes obtained from clone libraries were used to elucidate community structure across all domains. The hypolithon was dominated by cyanobacterial phylotypes (73%) with relatively low frequencies of other bacterial phylotypes, largely represented by the chloroflexi, actinobacteria, and bacteriodetes. Unidentified crenarchaeal phylotypes accounted for 4% of recoverable phylotypes, while algae, fungi, and mosses were indicated by a small fraction of recoverable phylotypes.  相似文献   
173.
Soils are typically considered to be suboptimal environments for enteric organisms, but there is increasing evidence that Escherichia coli populations can become resident in soil under favorable conditions. Previous work reported the growth of autochthonous E. coli in a maritime temperate Luvic Stagnosol soil, and this study aimed to characterize, by molecular and physiological means, the genetic diversity and physiology of environmentally persistent E. coli isolates leached from the soil. Molecular analysis (16S rRNA sequencing, enterobacterial repetitive intergenic consensus PCR, pulsed-field gel electrophoresis, and a multiplex PCR method) established the genetic diversity of the isolates (n = 7), while physiological methods determined the metabolic capability and environmental fitness of the isolates, relative to those of laboratory strains, under the conditions tested. Genotypic analysis indicated that the leached isolates do not form a single genetic grouping but that multiple genotypic groups are capable of surviving and proliferating in this environment. In physiological studies, environmental isolates grew well across a broad range of temperatures and media, in comparison with the growth of laboratory strains. These findings suggest that certain E. coli strains may have the ability to colonize and adapt to soil conditions. The resulting lack of fecal specificity has implications for the use of E. coli as an indicator of fecal pollution in the environment.Escherichia coli is a well-established indicator of fecal contamination in the environment. The organism''s validity as an indicator of water pollution is dependent, among other factors, on its fecal specificity and its inability to multiply outside the primary host, the gastrointestinal tracts of humans and warm-blooded animals (9). While many pathogens and indicator organisms are considered to be poorly adapted for long-term survival, or proliferation, outside their primary hosts (24), there is increasing evidence that this view needs to be reconsidered with respect to E. coli (17, 38). In particular, questions remain about its fate and survival capacity in environmental matrices, such as soil. While the habitat within the primary host is characterized by constant warm temperature conditions and a ready availability of nutrients and carbon, that of soil is often characterized by oligotrophic and highly dynamic conditions, temperature and pH variation, predatory populations, and competition with environmentally adapted indigenous microflora (39). Soils are thus typically considered to be suboptimal environments for enteric organisms, and growth is thought to be negligible, with die-off of organisms at rates reported to be a function of the interaction of numerous factors, including the type and physiological state of the microorganism, the physical, chemical, and biological properties of the soil, atmospheric conditions (including sunlight, moisture, and temperature), and organism application method (10).In recent years, the growth of E. coli in soils, sediments, and water in tropical and subtropical regions has been widely documented, and the organism is considered to be an established part of the soil biota within these regions (4, 5, 7, 12, 14, 19, 25, 32). The integration of E. coli as a component of the indigenous microflora in soils of tropical and subtropical regions may be attributable to the nutrient-rich nature and warm temperatures of these habitats (21, 39), combined with the metabolic versatility of the organism and its simple nutritional requirements (21). In addition to tropical and subtropical regions, the presence of autochthonous E. coli populations in the cooler soils of temperate and northern temperate regions has also been reported (6, 20, 22, 37), with one report on an alpine soil (34) and, most recently, a report on a maritime temperate grassland soil (3). The growth of E. coli within soils can act as a reservoir for the further contamination of bodies of water (20, 31, 32), compromising the indicator status of E. coli within these regions. As such, an understanding of the ecological characteristics of E. coli in soil is critical to its validation as an indicator organism. With respect to the input of pathogenic E. coli into the environment, this knowledge becomes essential for assessing the potential health risk to human and animal hosts from agricultural activities such as landspreading of manures and slurries (24).It has been suggested that E. coli can sustain autochthonous populations within soils in temperate regions, wherever favorable conditions exist (21). The phenotypic traits of the organism (including its metabolic diversity and its ability to grow both aerobically and anaerobically in a broad temperature range) may assist the persistence, colonization, and growth of E. coli when conditions permit. The challenging nature of the soil environment and the disparity of conditions between the primary host and the secondary habitat raises the question of how these E. coli populations survive and compete for niche space among the highly competitive and diverse coexisting populations of the indigenous microflora (15, 21). There is some evidence that naturalized E. coli may form genetically distinct populations in the environment (17, 20, 34, 36). This suggests that autochthonous E. coli populations in soil may have increased environmental fitness, facilitating their residence in soil (20, 34, 38). Little is known, however, of the physiology of these organisms, and their capacity for survival in soil remains poorly understood (21).Previous work (3) recorded continuous low-level leaching of viable E. coli from lysimeters of a poorly drained Luvic Stagnosol soil type, more than 9 years after the last application of fecal material. This finding was indicative of the growth of E. coli within the soil and suggested the presence of autochthonous E. coli populations within the soil that could be leached subsequently. To our knowledge, prior to this report, naturalized autochthonous E. coli populations persisting under the relatively oligotrophic, low-temperature conditions of maritime temperate soil environments had not been described previously. Growth within this soil was attributed chiefly to favorable characteristics of the soil, which include high clay and moisture contents, nutrient retention, and the presence of anaerobic zones. The objective of this work was to characterize, by molecular and physiological means, the genetic diversity and physiology of environmentally persistent E. coli isolates leached. In particular, we were interested in determining if the isolates possessed phenotypic characteristics that may enhance their capacity to survive and occupy niche space within the soil. This study tested the hypothesis that E. coli clones persisting in lysimeters of this soil form a genetically distinct grouping and possess a physiology tailored to the soil environment.  相似文献   
174.
Clostridium difficile is a major cause of antibiotic-associated diarrheal disease in many parts of the world. In recent years, distinct genetic variants of C. difficile that cause severe disease and persist within health care settings have emerged. Highly resistant and infectious C. difficile spores are proposed to be the main vectors of environmental persistence and host transmission, so methods to accurately monitor spores and their inactivation are urgently needed. Here we describe simple quantitative methods, based on purified C. difficile spores and a murine transmission model, for evaluating health care disinfection regimens. We demonstrate that disinfectants that contain strong oxidizing active ingredients, such as hydrogen peroxide, are very effective in inactivating pure spores and blocking spore-mediated transmission. Complete inactivation of 106 pure C. difficile spores on indicator strips, a six-log reduction, and a standard measure of stringent disinfection regimens require at least 5 min of exposure to hydrogen peroxide vapor (HPV; 400 ppm). In contrast, a 1-min treatment with HPV was required to disinfect an environment that was heavily contaminated with C. difficile spores (17 to 29 spores/cm2) and block host transmission. Thus, pure C. difficile spores facilitate practical methods for evaluating the efficacy of C. difficile spore disinfection regimens and bringing scientific acumen to C. difficile infection control.Clostridium difficile is a Gram-positive, spore-forming, anaerobic bacterium that is a major cause of health care-acquired infections and antibiotic-associated diarrhea (2). In recent years, several genetic variants of C. difficile have emerged as important health care pathogens (6). Perhaps most notable is the “hypervirulent” variant, commonly referred to as PCR ribotype 027/restriction endonuclease analysis (REA) group BI, that produces elevated levels of toxins TcdA and TcdB (17, 19). Other virulent ribotypes that display extensive heterogeneity among their toxin protein sequences (26) and gene activities (8) have emerged. Using whole-genome sequencing, we demonstrated that there are broad genetic differences between the entire genomes of several common variants, including ribotype/REA group variants 012/R, 017/CF, and 027/BI used in this study (12, 27, 31). In contrast, phylogeographic analysis of 027/BI isolates from Europe and the United States demonstrates that this clade is extremely clonal and implies recent transcontinental spread of hypervirulent C. difficile (12).C. difficile is distinct from many other health care pathogens because it produces highly infectious spores that are shed into the environment (25, 28). C. difficile spores can resist disinfection regimens that normally inactivate other health care pathogens, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, therefore challenging current infection control measures (2). A multifaceted approach is normally used to control C. difficile in health care facilities (32). Interventions include antimicrobial stewardship, increased clinical awareness, patient isolation (11), and enhanced environmental disinfection regimens based on hydrogen peroxide (H2O2) vapor (HPV) (4). While attempts to break the spore-mediated infection cycle and interrupt these efficient routes of transmission are important for infection control measures, there is little quantitative evidence indicating which interventions are most effective (7). Here we describe the exploitation of pure C. difficile spores (16) and a murine transmission model (15) in simple, practical methods to quantitatively monitor the impact of health care disinfection regimens on C. difficile viability. These methods can be used to optimize disinfection regimens targeted at C. difficile.  相似文献   
175.
Enteropathogen contamination of groundwater, including potable water sources, is a global concern. The spreading on land of animal slurries and manures, which can contain a broad range of pathogenic microorganisms, is considered a major contributor to this contamination. Some of the pathogenic microorganisms applied to soil have been observed to leach through the soil into groundwater, which poses a risk to public health. There is a critical need, therefore, for characterization of pathogen movement through the vadose zone for assessment of the risk to groundwater quality due to agricultural activities. A lysimeter experiment was performed to investigate the effect of soil type and condition on the fate and transport of potential bacterial pathogens, using Escherichia coli as a marker, in four Irish soils (n = 9). Cattle slurry (34 tonnes per ha) was spread on intact soil monoliths (depth, 1 m; diameter, 0.6 m) in the spring and summer. No effect of treatment or the initial soil moisture on the E. coli that leached from the soil was observed. Leaching of E. coli was observed predominantly from one soil type (average, 1.11 ± 0.77 CFU ml−1), a poorly drained Luvic Stagnosol, under natural rainfall conditions, and preferential flow was an important transport mechanism. E. coli was found to have persisted in control soils for more than 9 years, indicating that autochthonous E. coli populations are capable of becoming naturalized in the low-temperature environments of temperate maritime soils and that they can move through soil. This may compromise the use of E. coli as an indicator of fecal pollution of waters in these regions.The contamination of groundwater, including potable water supplies, with microbial pathogens continues to be a global concern (52, 59). Of particular importance in developed countries are the high levels of contamination associated with small-scale and very-small-scale drinking water supplies (5, 19, 57), often groundwater, which serve an estimated 10% of the total population in the European Union (13). The high numbers of these water supplies found to be contaminated with fecal bacteria and thus considered to be unfit for human consumption are worrying because the water from them is often untreated or inadequately treated prior to consumption. Microbial pathogens are known to survive for considerable periods of time in groundwater (29), which increases the health risk due to utilization of contaminated supplies. There are various sources of contamination, but evidence suggests that contamination from the spreading of animal slurries and manures on land can be a significant contributor (3, 33, 53). Spreading of agricultural slurries and manures on land is used by the agricultural sector as a means of nutrient recycling. The health risks associated with the spreading of animal and human wastes containing enteric pathogens have been recognized for a long time (10, 18). Animal manure and wastewaters may contain a broad range of pathogenic microorganisms, including Escherichia coli O157:H7, Campylobacter, Cryptosporidium, Salmonella spp., and pathogenic viruses, which are released into the environment during spreading (15, 22, 55). The levels and incidence of pathogens present in animal manures and slurries are influenced by a number of factors, including herd health, age demographics, stress factors, diet, season, and manure management and storage (37, 39).Soils (and subsoils) often act as a zone for mitigating microbial contamination of groundwater associated with the spreading of animal slurries and manures on land. Some of the pathogenic microorganisms applied to agricultural soils have, however, been observed to leach through the soil into groundwater, which can affect drinking water quality and pose a risk to public health (16, 26, 28, 42, 50), confirming that soil is not always a sufficient obstruction for protection of groundwater (16, 53). Consequently, characterization of the movement of pathogens through the unsaturated soil and subsoil zone (vadose zone) has become critical for assessment of the risk to groundwater posed by agricultural activities (8, 14, 42). The soil and subsoil type is believed to be a major factor influencing the potential transfer of pathogens through soil to groundwater (3, 34, 41, 50). The preapplication moisture status of a soil, which may be influenced by the season, also impacts pathogen survival, fate, and transport (2, 11, 43, 54).E. coli is widely used as an indicator of fecal contamination of water, and certain strains are known to be pathogenic (12). Thus, characterizing this organism''s transport through soil is important because of the health risk posed by the organism itself and with regard to its validity as an indicator of the fate of enteropathogens in the environment. E. coli strains have diverse properties and capabilities that affect their survival and transport in soils (9, 36, 56, 60). Consequently, data obtained by using total E. coli rather than individual surrogate strains can be more representative of the fate and transport of E. coli present in animal slurries. E. coli O157 die-off in soils has been reported to be the same as or quicker than total E. coli die-off, suggesting that data for total E. coli provide a conservative estimate of the survival potential (38, 56). Although many field and laboratory studies have investigated E. coli transport through soil columns (4, 6, 16, 43, 46, 47, 50, 51), most studies have investigated transport through soil to a depth of less than 30 cm. For assessment of the risk of transport to groundwater, such studies may not take into account the variation in soil physical and chemical characteristics with depth (e.g., the frequency and continuity of macropores, organic matter, and moisture contents) that affect bacterial transport. Furthermore, rainfall was often simulated in previous studies, which allows experimental conditions to be controlled but may not be representative of the risk due to variable natural rainfall events over time. In this study, we used intact soil monoliths that were 1 m deep to assess the risk of leaching of total E. coli in four representative Irish soil types under natural rainfall and environmental conditions.The objective of this study was to quantitatively investigate the impact of soil type and season (soil moisture content) on the fate and transport of E. coli spread on four different temperate maritime soil types under natural rainfall conditions. We hypothesized that there would be a greater microbial risk to underlying groundwater with better-drained soil types than with relatively poorly drained soil types following the application of animal slurry. In addition, we hypothesized that E. coli cells spread on wetter spring soils would be transported in greater numbers than E. coli cells spread on drier soils in the summer.  相似文献   
176.
177.
178.

Introduction  

Type 4 phosphodiesterases (PDE4) play an important role in immune cells through the hydrolysis of the second messenger, cAMP. Inhibition of PDE4 has previously been shown to suppress immune and inflammatory responses, demonstrating PDE4 to be a valid therapeutic target for immune-mediated pathologies. We assessed the anti-inflammatory effects of a novel PDE4 inhibitor, apremilast, in human synovial cells from rheumatoid arthritis (RA) patients, as well as two murine models of arthritis.  相似文献   
179.

Introduction

Rheumatoid arthritis (RA) is a systemic disease manifested by chronic inflammation in multiple articular joints, including the knees and small joints of the hands and feet. We have developed a unique modification to a clinically accepted method for delivering therapies directly to the synovium. Our therapy is based on our previous discovery of an analog peptide (A9) with amino acid substitutions made at positions 260 (I to A), 261 (A to B), and 263 (F to N) that could profoundly suppress immunity to type II collagen (CII) and arthritis in the collagen-induced arthritis model (CIA).

Methods

We engineered an adenoviral vector to contain the CB11 portion of recombinant type II collagen and used PCR to introduce point mutations at three sites within (CII124-402, 260A, 261B, 263D), (rCB11-A9) so that the resulting molecule contained the A9 sequence at the exact site of the wild-type sequence.

Results

We used this construct to target intra-articular tissues of mice and utilized the collagen-induced arthritis model to show that this treatment strategy provided a sustained, local therapy for individual arthritic joints, effective whether given to prevent arthritis or as a treatment. We also developed a novel system for in vivo bioimaging, using the firefly luciferase reporter gene to allow serial bioluminescence imaging to show that luciferase can be detected as late as 18 days post injection into the joint.

Conclusions

Our therapy is unique in that we target synovial cells to ultimately shut down T cell-mediated inflammation. Its effectiveness is based on its ability to transform potential inflammatory T cells and/or bystander T cells into therapeutic (regulatory-like) T cells which secrete interleukin (IL)-4. We believe this approach has potential to effectively suppress RA with minimal side effects.  相似文献   
180.
Bid, a caspase-activated proapoptotic BH3-only protein, is essential for Fas-induced hepatocyte destruction. Recent studies published in Cell produced conflicting results, indicating that loss of Bid either protects or enhances apoptosis induced by DNA damage or replicative stress. To resolve this controversy, we generated novel Bid-deficient mice on an inbred C57BL/6 background and removed the drug-selection cassette from the targeted locus. Nine distinct cell types from these Bid-deficient mice underwent cell-cycle arrest and apoptosis in a manner indistinguishable from control WT cells in response to DNA damage or replicative stress. Moreover, we found that even cells from the original Bid-deficient mice responded normally to these stimuli, indicating that differences in genetic background or the presence of a strong promoter within the targeted locus are unlikely to explain the differences between our results and those reported previously. We conclude that Bid has no role in DNA damage- or replicative stress-induced apoptosis or cell-cycle arrest.  相似文献   
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