Aims Plants affect each other by modifying soils conditions in plant-soil feedbacks, where associated microbes have an integral role. Since epichloid endophytes and arbuscular mycorrhizal fungi (AMF) ...are highly widespread grass symbionts, here we explore the role of AMF and endophyte in plant-soil feedback within the same grass population. Methods Through a manipulative experiment, we evaluated the performance of endophyte-free and endo phyte-associated Lolium multiflorum plants grown in soils previously conditioned by endophyte-free and endophyte-associated plants and inoculated or not with three AMF species. Results The biomass of endophyte-free and endophyte-associated plants was increased by AMF inoculation, when growing in soils conditioned by equal endophytic status plants (i.e. home soils). When growing in soils conditioned by plants with different endophytic status, plant biomass was higher than in home soil only in absence of AMF. The content of P and the arbuscular colonization also increased in plants growing in home soils. Conclusion We demonstrated that AMF shift the intraspecific feedback effects between E+ and E− conspecific plants from negative to positive. Furthermore, we found that the outcome of simultaneous occurrence of foliar and root symbionts on grass performance depends on the matching with the endophytic status of the previous plant.
Plant litter is a key component of plant–soil feedback (PSF), given its strong potential impacts on plant establishment and growth, through chemical and physical pathways. Although PSF of the layer ...of dead plant material on the soil surface (above‐ground litter) has been widely studied, little is known about the role of dead roots (below‐ground litter) and the impact of plant symbionts on host litter legacy.
Here, we examined whether the fungal endophyte Epichloë occultans changed the effects of above‐ and below‐ground litter of Lolium multiflorum plants on the establishment of Trifolium repens. We hypothesized that both types of litter deposited by the grass‐endophyte symbiosis reduce the establishment of the legume due to the release of allelopathic compounds during the decomposition and leaching processes.
To test this, we performed two experiments with different quantities of litter produced by plants of the same grass population, with high and low levels of endophyte infection (E+ and E−). Seeds of T. repens were exposed to the above‐ground litter with or without the addition of below‐ground litter, or to their leachates, to separate the physical and chemical pathways.
We found that the treatments with the combination of the above‐ and below‐ground litter produced by E+ plants increased the germination speed and seedling emergence of T. repens by 56% compared with both types of litter produced by E− plants. A similar effect was also observed with only the above‐ground litter. However, the below‐ground litter of E+ plants reduced the germination speed, seedling emergence by 76% and establishment of T. repens by 73% compared with the below‐ground litter of E− plants. Besides, the below‐ground litter had positive effects on the root colonization by arbuscular mycorrhizal fungi and reduced the root nodulation of T. repens. The quantity of litter did not affect any of these responses.
Our results suggest that these litter legacy effects could be due to the release of endophyte‐induced secondary metabolites, such as phenolic and flavonoid compounds. Changes in host plant litter inputs may have consequences for the prevalence of legume plants in grasslands and pastures, affecting their quality and dynamics.
A free Plain Language Summary can be found within the Supporting Information of this article.
Resumen
El material muerto depositado por las plantas (broza) es clave en la retroalimentación planta‐suelo (PSF), ya que impacta sobre el establecimiento y el crecimiento de plantas por vías físicas y químicas. Aunque los efectos de PSF sobre la broza aérea (tallos y hojas muertas) ha sido muy estudiado, poco se sabe del papel de la broza subterránea (raíces muertas) y de los cambios que los simbiontes de plantas inducen en el legado de su hospedante.
Examinamos si el hongo endófito Epichloë occultans cambia los efectos de la broza aérea y subterránea de Lolium multiflorum sobre el establecimiento de Trifolium repens. Hipotetizamos que los endófitos modifican el legado del hospedante a través de la liberación de compuestos alelopáticos presentes en ambos tipos de broza durante la descomposición y lixiviación, reduciendo el establecimiento de la leguminosa.
Realizamos dos experimentos con diferentes cantidades de broza producida por plantas de la misma población de una gramínea, con niveles altos y bajos de infección endofítica (E+ y E−). Para separar las vías físicas y químicas, expusimos las semillas de T. repens a la broza aérea con o sin la subterránea, o a los lixiviados de los distintos tipos broza.
La combinación de broza aérea y subterránea de plantas E+ aumentó un 56% la velocidad de germinación y la emergencia de plántulas de T. repens, comparado con la de plantas E−. Observamos un efecto similar en las macetas que contenían sólo broza aérea. Sin embargo, en comparación con la broza subterránea de plantas E−, la broza subterránea de plantas E+ redujo en más del 70% la velocidad de germinación, la emergencia y el establecimiento final de T. repens. Además, la broza subterránea redujo la nodulación y aumentó la micorrización de T. repens. La cantidad de broza no modificó las respuestas observadas.
Los efectos hallados podrían deberse a la liberación de metabolitos secundarios (fenólicos y flavonoides) inducidos por los endófitos. Los cambios en el legado de las plantas hospedantes tendrían consecuencias para el establecimiento de las leguminosas en pastizales y pasturas, lo que afectaría la estructura y el funcionamiento de la comunidad.
A free Plain Language Summary can be found within the Supporting Information of this article.
•PCR assays to detect key mutations of SARS-CoV-2 spike protein are described•Discrimination of Variants of Concern (VOCs) and other variants is achieved•The assays detected key mutations of ...20I/501Y.V1 and 20 J/501Y.V3 in sewage in Italy•The method allows rapid and cost-effective detection of VOCs in sewage for WBE•The described approach can be used for rapid screening in clinical samples
New SARS-CoV-2 mutations are constantly emerging, raising concerns of increased transmissibility, virulence or escape from host immune response.
We describe a nested RT-PCR assay (~1500 bps) to detect multiple nucleotide changes resulting in key spike protein mutations distinctive of the major known circulating SARS-CoV-2 variants, including the three Variants of Concern (VOCs) 20I/501Y.V1 (United Kingdom), 20H/501Y.V2 (South Africa), and 20 J/501Y.V3 (Brazil), as well as the 20E.EU1 variant (Spain), the CAL.20C recently identified in California, and the mink-associated variant (GR, lineage B.1.1.298). Prior to application to field samples, the discriminatory potential of this PCR assay was explored using GISAID and Nextclade. To extend variant detection to challenging matrices such as sewage, where the amplification of long fragments is problematic, two short nested RT-PCR assays (~300 bps) were also designed, targeting portions of the region spanned by the long nested assay.
The three newly-designed assays were then tested on field samples, including 31 clinical samples (7 fully-sequenced swab samples, and 24 uncharacterized ones) and 34 urban wastewater samples, some of which collected in areas where circulation of VOCs had been reported.
The long assay successfully amplified 29 of the 31 swabs (93%), allowing the correct identification of variants 20I/501Y.V1 and 20E.EU1 present in the panel of previously characterized samples. The Spanish variant was detected in 14/24 of the uncharacterized samples as well. The sequences obtained using the short assays were consistent with those obtained with the long assay. Mutations characteristic of VOCs (UK and Brazilian variant) and of other variant (Spanish) were detected in sewage samples. To our knowledge, this is the first evidence of the presence of sequences harboring key mutations of 20I/501Y.V1 and 20 J/501Y.V3 in urban wastewaters, highlighting the potential contribution of wastewater surveillance to explore SARS-CoV-2 diversity.
The developed nested RT-PCR assays can be used as an initial rapid screening test to select clinical samples containing mutations of interest. This can speed up diagnosis and optimize resources since it allows full genome sequencing to be done only on clinically relevant specimens. The assays can be also employed for a rapid and cost-effective detection of VOCs or other variants in sewage for the purposes of wastewater-based epidemiology. The approach proposed here can be used to better understand SARS-CoV-2 variant diversity, geographic distribution and impact worldwide.
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In August 2021, only 47.6% of all eligible residents in South Carolina (SC) had received at least one dose of the COVID-19 vaccine, with only 41% having completed their vaccination series. ...Additionally, only 27% of all Hispanics in SC had completed their vaccination series compared to 34.1% of non-Hispanics. Vaccine hesitancy is a complex phenomenon that is context and vaccine-specific. Focusing on unvaccinated Hispanics living in rural areas of SC, this study aimed to identify barriers to vaccination and provide an educational intervention designed to address vaccine hesitancy.
A complex mixed-methods evaluation design was used to conduct this study. First, in-person vaccine educational sessions were implemented, along with a pre-post-test survey, to assess changes in knowledge, attitudes, motivations, barriers, and intentions to receive COVID-19 vaccination. Second, in-person follow-up focus groups were held with the same participants to gather in-depth insight about participants' knowledge and attitudes about the COVID-19 vaccination. Third, an online follow-up survey was conducted to assess the effect of the training and discussion session on COVID-19 vaccination. Study outcomes were assessed among the 17 individuals who participated in the educational sessions and focus group discussions.
Findings revealed that for unvaccinated Hispanics living in South Carolina; vaccine hesitancy was primarily driven by: 1) misinformation and information coming from unverified sources and 2) negative perceptions of the safety and effectiveness of the COVID-19 vaccines. Specifically, participants were fearful that the vaccine development was rushed and that the vaccines might contain questionable ingredients that could cause strong side effects or even death. Participants were also concerned that vaccination might cause them to get sick and be hospitalized, which would have financial implications since they could not afford healthcare or take time off work.
Program implementation and mass communication campaigns should focus on COVID-19 vaccine safety and effectiveness, including side effects, what to expect after being vaccinated, and how to look for information from reputable sources. The educational session implemented proved to be effective and helped reduce vaccine hesitancy since most participants (80%) self-reported receiving a COVID-19 vaccine after program participation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Background Access to mental and physical healthcare in rural areas is challenging for Veterans and their families but essential for good health. Even though recent research has revealed some ...of the challenges rural Veterans face accessing healthcare, a complete understanding of the gap in access is still unclear. Methods This qualitative study aimed to explore participants’ perceptions of healthcare access. Structured interviews were conducted with 124 Veterans and spouses of Veterans from rural qualifying counties in South Carolina and Florida. Results The study’s results revealed five main dimensions of access: geographic proximity, transportation, communication, cultural competence, and resources. Distance to service needed can negatively impact access for Veterans and their families in general, especially for those whose health is declining or who cannot drive because of their age. Lack of transportation, problems with transportation services, and lack of public transportation can lead to delays in care. Additionally, the lack of communication with the Veterans Affairs (VA) Health System and with the healthcare team, as well as inefficient communication among the healthcare team, lack of coordination of care between the VA health system and community providers, and the lack of cultural competence of healthcare providers and contracted personnel made access to services even more challenging. Conclusions Improving communication can help to develop a sense of trust between Veterans and the VA, and between Veterans and spouses with the healthcare team. It can also lead to increased patient satisfaction. Ensuring healthcare providers and contracted personnel are culturally competent to talk and treat Veterans can improve patient trust and adherence to treatment. Lastly, resource-related challenges included financial problems, lack of prompt access to appointments, lack of providers, limited access to local clinics and hospitals, limited local programs available, and reimbursement issues.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Four-years of annual glyphosate applications impaired beneficial soil microorganisms.•This field experiment detected different glyphosate sensitivities among microorganisms.•AMF arbuscules and DSE ...root colonization were reduced at recommended field dose.•AMF spores and free-living diazotrophs were reduced at lower than recommended dose.•Repeated-glyphosate effects on soil biota benefits might affect grasslands community.
Due to the worldwide use of the herbicide glyphosate, there is a growing interest in understanding its impact on beneficial soilmicroorganisms. However, most studies have been focused on evaluating the effects on these microorganisms of a single application in agricultural crops, despite the fact that repeated applications is a common scenario in different production systems. We evaluated the impact of four annual glyphosate applications on arbuscular mycorrhizal fungi (AMF), dark septate endophytes (DSE) and free-living diazotrophs in a temperate grassland. Sub-lethal (0.8lha−1) and recommended field doses (3lha−1) were analyzed. AMF viable spores and free-living diazotrophs densities were reduced by 56% and 82% respectively, after the fourth application even at sublethal dose. While total AMF root colonization in Lolium arundinaceum was not affected among treatments, arbuscules percentage was reduced in plants grown in plots treated with 3lha−1. A similar response was detected in DSE root colonization. Considering the role they have in structuring plant communities, these deleterious effects on beneficial soil microorganisms might negatively impact on grassland productivity and diversity. It is necessary to investigate the resilience of the microbial community in order to develop a long-term strategic management of glyphosate applications that would achieve the desired objectives without irreversibly affecting soil biota.
Corrosion of metallic oilfield pipelines by microorganisms is a costly but poorly understood phenomenon, with standard treatment methods targeting mesophilic sulfate-reducing bacteria. In assessing ...biocorrosion potential at an Alaskan North Slope oil field, we identified thermophilic hydrogen-using methanogens, syntrophic bacteria, peptide- and amino acid-fermenting bacteria, iron reducers, sulfur/thiosulfate-reducing bacteria, and sulfate-reducing archaea. These microbes can stimulate metal corrosion through production of organic acids, CO2, sulfur species, and via hydrogen oxidation and iron reduction, implicating many more types of organisms than are currently targeted. Micromolar quantities of putative anaerobic metabolites of C1−C4 n-alkanes in pipeline fluids were detected, implying that these low molecular weight hydrocarbons, routinely reinjected into reservoirs for oil recovery purposes, are biodegraded and can provide biocorrosive microbial communities with an important source of nutrients.
This paper assesses the prevalence of MRSA in bulk tank milk (BTM) samples from southern Italy, and the relationship between the Coagulase Positive Staphylococci count (CPS) and MRSA prevalence. Of ...486 BTM samples tested, 12 samples (2.5%) resulted positive for the presence of MRSA. Great genetic diversity was found among the isolates: ST1/t127 and t174/IVa, ST5/t688/V, ST8/t unknown/IVa/V, ST45/t015/IVa, ST71/t524/V, ST88/t786/Iva, ST398/t011 and t899/IVa/V and ST2781/t1730/V. All isolates were pvl-negative and icaA positive. The majority of strains (58%) carried the ses (sec, seh, seg, seo, sem and sen) genes. All tested strains resulted susceptible to amikacin, cephalotin, cloramphenicol, gentamycin, trimethoprim – sulfamethoxazole, tobramycin and vancomycin, and variably resistant to ampicillin, oxacillin and tetracycline. No statistical association between the CPS count and MRSA detection was found in the MRSA-positive samples. Although some of the spa-types and STs detected in our survey are known to cause human infections, raw milk from Italian herds in the considered area is not a common source of MRSA. Nonetheless, it is necessary to assess the risk of foodborne infection and the risk related to the handling of milk.
•Our study shows genetic diversity of MRSA in bulk tank milk.•The foodborne risk linked to the consumption of the raw milk meat appears limited.•The professional risk linked to the food handlers appears limited.•This is the first international report on the prevalence of MRSA in bulk tank milk from Italy.
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