Survival of enterococcal and streptococcal species in natural waters

Survival capabilities of indicators of fecal pollution, such as enterococci, in the natural aquatic environment are of particular importance in proper management of a watershed. The Las Vegas Wash (LVW) is a naturally occurring and engineered tributary to Lake Mead; The ability of the Las Vegas Wash to sustain microbial viability over time was assessed utilizing ATCC cultures and environmentally isolated species. Wash water samples were autoclaved and seeded with known concentrations of enterococci. Microcosms were incubated at 25°C, and decline was measured by heterotrophic plate counts at specific time intervals. Results of survival studies using ATCC derived species showed that the Wash could sustain microbial viability over extended periods of time, with the longest-lived species, E. faecium, surviving 74 days. Some isolates, however, were not able to persist in the oligotrophic environment of the wash and were not able to sustain viable cell counts past three weeks. (Abstract shortened by UMI.)

Assessment of the Perceived Role and Function of a Community Advisory Board in a NIH Center of Excellence: Lessons Learned

Background: The Community Advisory Board (CAB) was a vital component of the Center for Equal Health. The center addressed health disparities through community-based research and educational outreach initiatives. Objectives: To evaluate the perceived relationship of the CAB and Center, explore members’ perceptions of the CAB’s role, and elicit feedback on how to enhance the relationship between the Center and the CAB. Methods: Ten in-depth, semi-structured interviews were conducted. All interviews were transcribed verbatim and analyzed with a focus on predetermined codes. Results: Main themes focused on perception of CAB roles and need for utilization of board members; overall center challenges; and board member knowledge and communication within the center. Conclusions: Lessons learned mainly focused on clarification of CAB roles as necessary for more effective and efficient communication. Based on feedback, communication channels between the board and center were developed, orientation packets clarifying center roles were provided, and annual retreats were completed. Additional lessons learned for conducting community-academic partnerships are provided

Detrital Nutrient Content and Leaf Species Differenitally Affect Growth and Nutritional Regulation of Detritivores

© 2018 The Authors Resource nutrient content and identity are common bottom–up controls on organismal growth and nutritional regulation. One framework to study these factors, ecological stoichiometry theory, predicts that elevated resource nitrogen (N) and phosphorus (P) contents enhance organism growth by alleviating constraints on N and P acquisition. However, the regulatory mechanisms underlying this response – including whether responses depend on resource identity – remain poorly understood. In this study, we tested roles of detrital N and P contents and identity (leaf species) in constraining growth of aquatic invertebrate detritivores. We synthesized results from seven detritivore species fed wide nutrient gradients of oak and maple detritus in the laboratory. Across detritivore taxa, we used a meta-analytic approach quantifying effects of detrital leaf species and N and P contents on growth, consumption, and N- and P-specific assimilation and growth efficiencies. Detritivore growth rates increased on higher-N and P detritus and on oak compared to maple detritus. Notably, the mechanisms of improved growth differed between the responses to detrital nutrients versus leaf species, with the former driven by greater consumption rates despite lower assimilation efficiencies on higher-nutrient detritus, and the latter driven by improved N and P assimilation and N growth efficiencies on oak detritus. These findings suggest animal nutrient acquisition changes flexibly in response to resource changes, altering the fate of detrital N and P throughout regulation. We affirm resource identity and nutrients as important bottom–up controls, but suggest these factors act through separate pathways to affect organism growth and thereby change detrital ecosystems under anthropogenic forest compositional change and nutrient enrichment

Should the poultry red mite Dermanyssus gallinae be of wider concern for veterinary and medical science?

The poultry red mite Dermanyssus gallinae is best known as a threat to the laying-hen industry; adversely affecting production and hen health and welfare throughout the globe, both directly and through its role as a disease vector. Nevertheless, D. gallinae is being increasingly implemented in dermatological complaints in non-avian hosts, suggesting that its significance may extend beyond poultry. The main objective of the current work was to review the potential of D. gallinae as a wider veterinary and medical threat. Results demonstrated that, as an avian mite, D. gallinae is unsurprisingly an occasional pest of pet birds. However, research also supports that these mites will feed from a range of other animals including: cats, dogs, rodents, rabbits, horses and man. We conclude that although reported cases of D. gallinae infesting mammals are relatively rare, when coupled with the reported genetic plasticity of this species and evidence of permanent infestations on non-avian hosts, potential for host-expansion may exist. The impact of, and mechanisms and risk factors for such expansion are discussed, and suggestions for further work made. Given the potential severity of any level of host-expansion in D. gallinae, we conclude that further research should be urgently conducted to confirm the full extent of the threat posed by D. gallinae to (non-avian) veterinary and medical sectors

Global patterns and drivers of ecosystem functioning in rivers and riparian zones

River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth's biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented "next-generation biomonitoring" by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.peerReviewe