scholarly journals Evaporation-induced hydrodynamics promote conjugation-mediated plasmid transfer in microbial populations

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Chujin Ruan ◽  
Josep Ramoneda ◽  
Guowei Chen ◽  
David R. Johnson ◽  
Gang Wang
Keyword(s):  
Antibiotic Resistance ◽  
Microbial Communities ◽  
Driving Forces ◽  
Negative Relationship ◽  
Water Evaporation ◽  
Small Scale ◽  
Surface Deposition ◽  
Water Flows ◽  
Hydrodynamic Processes ◽  
Plasmid Conjugation

AbstractConjugative plasmids bestow important traits to microbial communities, such as virulence, antibiotic resistance, pollutant biotransformation, and biotechnology-relevant functions. While the biological mechanisms and determinants of plasmid conjugation are well established, the underlying physical and ecological driving forces remain unclear. Microbial communities often inhabit unsaturated environments, such as soils and host surfaces (e.g., skin, teeth, leaves, roots), where water evaporation and associated small-scale hydrodynamic processes frequently occur at numerous air-water and solid-water interfaces. Here, we hypothesized that evaporation can induce water flows with profound effects on the spatial distribution and surface deposition of cells, and consequently on the extent of plasmid conjugation. Using droplet experiments with an antibiotic resistance-encoding plasmid, we show that evaporation-induced water flows reduce cell-cell distances and significantly increase the extent of plasmid conjugation. Counterintuitively, we found that evaporation results in lower expression levels of conjugation-related genes. This negative relationship between the extent of plasmid conjugation and the expression of conjugation-related genes could be attributed to increased conjugation efficiency during evaporation. This study provides new insights into the physical and ecological determinants of plasmid conjugation, with important implications for understanding the spread and proliferation of plasmid-encoded traits.

scholarly journals The Socio-Economics Factors in Family Farms with Different Economic Sustainability Levels from Central and Eastern Europe

2021 ◽  
Vol 13 (15) ◽  
pp. 8262
Author(s):  
Katarzyna Smędzik-Ambroży ◽  
Marta Guth ◽  
Adam Majchrzak ◽  
Andreea Cipriana Muntean ◽  
Silvia Stefania Maican
Keyword(s):  
Eastern Europe ◽  
Central And Eastern Europe ◽  
Agricultural Sector ◽  
Negative Relationship ◽  
Policy Instruments ◽  
Small Scale ◽  
Economic Sustainability ◽  
Family Farms ◽  
Small Family ◽  
Generational Changes

Economic sustainability plays an important role in shaping conditions for economic growth and social development. The importance of answering the question about the level of sustainability of family farms results from the fact that the countries of Central and Eastern Europe, apart from exceptions (e.g. the Czech Republic and Slovakia), are characterized by a fragmented agrarian structure. Hence, the main goal of this article was to answer two questions: 1) whether the countries of Central and Eastern Europe differ in the level of economic sustainability of small family farms; and 2) whether the same socioeconomic factors impact similarly on the level of economic sustainability of small family farms from countries of Central and Eastern Europe. The study was based on surveys conducted in small family farms: in 2018 from Poland (672 farms) and in 2019 in four other countries (Lithuania; 999 farms, Romania; 834 farms, Serbia; 523 farms, Moldova; 530 farms). The publication includes a critical analysis of the literature, structure analysis and correlation analysis. The results show the occurrence of large differences between the economic sustainability of small family farms from the countries of Central and Eastern Europe. The research indicates that the larger the area of a small-scale family farm, the greater its economic sustainability. The productivity of these farms increases with their economic sustainability. The results also prove a negative relationship between the age of the farmer and the economic sustainability of their farm in all analysed countries. These trends were found in all analysed countries of Central and Eastern Europe. The results of the analyses support the conclusion that agricultural policy instruments aimed at increasing the economic sustainability of small family farms should lead to: land consolidation, a decrease in the age of farm owners through generational changes, and a decrease in employment in agriculture, which would lead to a reduction in labour input in the agricultural sector.

scholarly journals Metagenomics Analysis Reveals the Microbial Communities, Antimicrobial Resistance Gene Diversity and Potential Pathogen Transmission Risk of Two Different Landfills in China

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 230
Author(s):  
Shan Wan ◽  
Min Xia ◽  
Jie Tao ◽  
Yanjun Pang ◽  
Fugen Yu ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Microbial Communities ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Gene Diversity ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Pathogen Transmission ◽  
Transmission Risk ◽  
Antimicrobial Resistance Gene

In this study, we used a metagenomic approach to analyze microbial communities, antibiotic resistance gene diversity, and human pathogenic bacterium composition in two typical landfills in China. Results showed that the phyla Proteobacteria, Bacteroidetes, and Actinobacteria were predominant in the two landfills, and archaea and fungi were also detected. The genera Methanoculleus, Lysobacter, and Pseudomonas were predominantly present in all samples. sul2, sul1, tetX, and adeF were the four most abundant antibiotic resistance genes. Sixty-nine bacterial pathogens were identified from the two landfills, with Klebsiella pneumoniae, Bordetella pertussis, Pseudomonas aeruginosa, and Bacillus cereus as the major pathogenic microorganisms, indicating the existence of potential environmental risk in landfills. In addition, KEGG pathway analysis indicated the presence of antibiotic resistance genes typically associated with human antibiotic resistance bacterial strains. These results provide insights into the risk of pathogens in landfills, which is important for controlling the potential secondary transmission of pathogens and reducing workers’ health risk during landfill excavation.

scholarly journals Combined effects of composting and antibiotic administration on cattle manure–borne antibiotic resistance genes

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Ishi Keenum ◽  
Robert K. Williams ◽  
Partha Ray ◽  
Emily D. Garner ◽  
Katharine F. Knowlton ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Land Application ◽  
Multidimensional Analysis ◽  
Small Scale ◽  
Antibiotic Administration ◽  
Metagenomic Sequencing ◽  
Combined Effects ◽  
Bacterial Microbiota

Abstract Background Research is needed to delineate the relative and combined effects of different antibiotic administration and manure management practices in either amplifying or attenuating the potential for antibiotic resistance to spread. Here, we carried out a comprehensive parallel examination of the effects of small-scale (> 55 °C × 3 days) static and turned composting of manures from dairy and beef cattle collected during standard antibiotic administration (cephapirin/pirlimycin or sulfamethazine/chlortetracycline/tylosin, respectively), versus from untreated cattle, on “resistomes” (total antibiotic resistance genes (ARGs) determined via shotgun metagenomic sequencing), bacterial microbiota, and indicator ARGs enumerated via quantitative polymerase chain reaction. To gain insight into the role of the thermophilic phase, compost was also externally heated to > 55 °C × 15 days. Results Progression of composting with time and succession of the corresponding bacterial microbiota was the overarching driver of the resistome composition (ANOSIM; R = 0.424, p = 0.001, respectively) in all composts at the small-scale. Reduction in relative abundance (16S rRNA gene normalized) of total ARGs in finished compost (day 42) versus day 0 was noted across all conditions (ANOSIM; R = 0.728, p = 0.001), except when externally heated. Sul1, intI1, beta-lactam ARGs, and plasmid-associated genes increased in all finished composts as compared with the initial condition. External heating more effectively reduced certain clinically relevant ARGs (blaOXA, blaCARB), fecal coliforms, and resistome risk scores, which take into account putative pathogen annotations. When manure was collected during antibiotic administration, taxonomic composition of the compost was distinct according to nonmetric multidimensional analysis and tet(W) decayed faster in the dairy manure with antibiotic condition and slower in the beef manure with antibiotic condition. Conclusions This comprehensive, integrated study revealed that composting had a dominant effect on corresponding resistome composition, while little difference was noted as a function of collecting manure during antibiotic administration. Reduction in total ARGs, tet(W), and resistome risk suggested that composting reduced some potential for antibiotic resistance to spread, but the increase and persistence of other indicators of antibiotic resistance were concerning. Results indicate that composting guidelines intended for pathogen reduction do not necessarily provide a comprehensive barrier to ARGs or their mobility prior to land application and additional mitigation measures should be considered.

STUDY OF MICROBIAL COMMUNITIES IN MEAT PROCESSING ENTERPRISES

2021 ◽  
Author(s):  
Anastasia Arturovna Semenova ◽  
◽  
Yulia Konstantinovna Yushina ◽  
Maria Alexandrovna Grudistova ◽  
Elena Viktorovna Zaiko ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Microbial Diversity ◽  
Microbial Communities ◽  
Biofilm Formation ◽  
Pathogenic Microorganisms ◽  
Meat Processing ◽  
Production Environment

The article discusses the results of a study of the microbial diversity of objects in the production environment of two meat processing enterprises, including antibiotic resistance, isolated strains of pathogenic microorganisms and their ability to biofilm formation.

High Prevalence of Antibiotic Resistance in Pathogenic Escherichia coli from Large- and Small-Scale Poultry Farms in Bangladesh

2011 ◽  
Vol 55 (4) ◽  
pp. 689-692 ◽  
Author(s):  
Badrul Hasan ◽  
Rayhan Faruque ◽  
Mirva Drobni ◽  
Jonas Waldenström ◽  
Abdus Sadique ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Small Scale ◽  
Pathogenic Escherichia Coli ◽  
High Prevalence ◽  
Poultry Farms

scholarly journals Integration Efforts in Agriculture

2018 ◽  
Vol 12 (1-2) ◽  
pp. 91-96
Author(s):  
Judit Beke Lisányi
Keyword(s):  
Rural Areas ◽  
Agricultural Sector ◽  
Driving Forces ◽  
Jel Classification ◽  
Small Scale ◽  
Consumer Prices ◽  
Downward Pressure ◽  
Negative Impacts ◽  
Capital Intensive

The economic and political transition brought many challenges for the Hungarian agricultural sector. The break-up of large agricultural holdings had serious negative impacts on food production and on the export of agricultural products. Capital intensive profit-seeking intermediaries dominate the trading of agricultural goods that has injurious effects in terms of downward pressure on production prices and an increase in consumer prices. Cooperatives have a key role in effectively tackling the common challenges that small-scale producers have to face. More vertical integration along the food chain could contribute to providing rural employment and to an increase in living standards in rural areas. This study reviews the development, the specific features and the driving forces of modern cooperatives in Central Europe in general, and in Hungary in particular. The focus is on the integrator role of cooperatives and their future role in our globalised world. JEL Classification: Q10, Q13

Spatial Perspectives on Coworking Spaces and Related Practices in Beijing

2020 ◽  
Vol 46 (1) ◽  
pp. 40-54
Author(s):  
He Huang ◽  
Yangfanqi Liu ◽  
Yuebing Liang ◽  
David Vargas ◽  
Lu Zhang
Keyword(s):  
Large Scale ◽  
Driving Forces ◽  
Empirical Studies ◽  
Analytical Framework ◽  
Sharing Economy ◽  
Small Scale ◽  
The Sustainable Development ◽  
Knowledge Economies ◽  
Coworking Spaces ◽  
The City

Coworking space is a recent manifestation of the emerging sharing economy. This is largely due to two core driving forces: a new working style in the creative and knowledge economies, and the sharing economy, which promotes resource usage efficiency. This paper develops an analytical framework for the spatial perspectives on coworking spaces according to the core driving forces at both the urban and architectural levels, followed by empirical studies on practices related to coworking space in Beijing. The results indicate that at the city scale, coworking spaces tend to aggregate in clusters of large-scale creative and knowledge enterprises in mixed-use and high-density areas, and underutilized spaces become the key pillar. In the architectural dimension, coworking spaces tend to coexist with conventional office spaces or coliving apartments. Empirical studies in Beijing also show that coworking spaces have promoted the sustainable development of the city by renewing existing low-profit urban spaces and utilizing architectural spaces more efficiently. However, the unstable lease market of small-scale businesses, as well as marginal financial models, which pro fit from rental differences, challenge the survival of coworking spaces. In pursuit of capital, coworking spaces have tended to overexpand.

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