This study examines academic burnout syndrome and its relation to personal and academic variables among university students in nursing and early childhood education programs in Spain. A total of 606 ...university students (primary education: 49.7%; nursing: 49.7%) of both sexes (71.5% female) with an average age of 20.68 years (SD = 1.65) participated. An ex post facto retrospective single-group design was planned. The instruments used were the Maslach Burnout Inventory-Student Survey (MBI-SS) and the NEO Five-Factor Inventory (NEO-FFI). Nursing students, who reported more study hours, less sleep, and lower grades, had higher academic burnout scores. Linear regression models were proposed to analyze the relationship between academic burnout, personality, and sociodemographic variables. Nursing students scored higher in emotional exhaustion and lower in cynicism, and they scored higher in neuroticism and openness. Furthermore, 16.1% of the variance in academic burnout was explained by personality variables as well as the degree studied, course year, and study hours. These findings suggest the importance of considering both academic and personality variables in understanding academic burnout in university students.
The increasing trend in sea surface temperature promotes the spread of Vibrio species, which are known to cause diseases in a wide range of marine organisms. Among these pathogens, Vibrio ...mediterranei has emerged as a significant threat, leading to bleaching in the coral species Oculina patagonica. Bacteriophages, or phages, are viruses that infect bacteria, thereby regulating microbial communities and playing a crucial role in the coral's defense against pathogens. However, our understanding of phages that infect V. mediterranei is limited. In this study, we identified two phage species capable of infecting V. mediterranei by utilizing a combination of cultivation and metagenomic approaches. These phages are low-abundance specialists within the coral mucus layer that exhibit rapid proliferation in the presence of their hosts, suggesting a potential role in coral defense. Additionally, one of these phages possesses a conserved domain of a leucine-rich repeat protein, similar to those harbored in the coral genome, that plays a key role in pathogen recognition, hinting at potential coral-phage coevolution. Furthermore, our research suggests that lytic Vibrio infections could trigger prophage induction, which may disseminate genetic elements, including virulence factors, in the coral mucus layer. Overall, our findings underscore the importance of historical coral-phage interactions as a form of coral immunity against invasive Vibrio pathogens.
Five brightly red-pigmented, motile, rod-shaped, extremely halophilic bacteria were isolated from saltern crystallizer ponds in Alicante (two strains) and Mallorca (three strains), Spain. They grew ...optimally at salt concentrations between 20 and 30% and did not grow below 15% salts. Thus, these isolates are among the most halophilic organisms known within the domain Bacteria. The temperature optimum was 37-47 degrees C. A single, yet to be identified pigment was present, with an absorption maximum at 482 nm and a shoulder at 506-510 nm. The G+C content of the DNA was 66.3-67.7 mol% and, together, they formed a homogeneous genomic group with DNA-DNA similarities above 70%. The 16S rRNA gene sequences were almost identical to sequences recovered earlier from the saltern biomass by amplification of bacterial small-subunit rRNA genes from DNA extracted from the environment. This phylotype, earlier described as 'Candidatus Salinibacter', was shown by fluorescence in situ hybridization to contribute between 5 and 25% of the prokaryote community of the saltern crystallizers. We have therefore succeeded in isolating a bacterium from the natural environment that, although being a major component of the community, was previously known by its phylotype only. Isolation of the organism now allows formal description of a novel genus and species, for which we propose the name Salinibacter ruber gen. nov., sp. nov. The type strain is strain M31T (= DSM 13855T = CECT 5946T).
Marine heat waves (MHWs) are periods of extremely high seawater temperature that affect marine ecosystems in several ways. Anthozoans (corals and gorgonians) and Porifera (sponges) are usually among ...the taxa most affected by MHWs. Both are holobiont entities that form complex interactions with a wide range of microbes, which are an essential part of these organisms and play key roles in their health status. Here, we determine microbial community changes suffered in two corals (
Cladocora caespitosa
and
Oculina patagonica
), one gorgonian (
Leptogorgia sarmentosa
) and one sponge (
Sarcotragus fasciculatus
) during the 2015 MHW. The microbial communities were different among hosts and displayed shifts related to host health status, with a higher abundance in necrosed tissues of
Ruegeria
species or of potential pathogens like
Vibrio
. We also carry out a meta-analysis using 93 publicly accessible 16S rRNA gene libraries from
O. patagonica
,
C. caespitosa
and
L. sarmentosa
to establish a Mediterranean core microbiome in these species. We have identified one
Ruegeria
OTU that maintained a stable and consistent association with these species, which was also related to tissue necrosis in their hosts. Therefore,
Ruegeria
sp. could play an important and still underexplored role in the health status of its hosts.
Homologous recombination (HR) enables the exchange of genetic material between and within species. Recent studies suggest that this process plays a major role in the microevolution of microbial ...genomes, contributing to core genome homogenization and to the maintenance of cohesive population structures. However, we still have a very poor understanding of the possible adaptive roles of intraspecific HR and of the factors that determine its differential impact across clades and lifestyles. Here we used a unified methodological framework to assess HR in 338 complete genomes from 54 phylogenetically diverse and representative prokaryotic species, encompassing different lifestyles and a broad phylogenetic distribution. Our results indicate that lifestyle and presence of restriction-modification (RM) machineries are among the main factors shaping HR patterns, with symbionts and intracellular pathogens having the lowest HR levels. Similarly, the size of exchanged genomic fragments correlated with the presence of RM and competence machineries. Finally, genes exchanged by HR showed functional enrichments which could be related to adaptations to different environments and ecological strategies. Taken together, our results clarify the factors underlying HR impact and suggest important adaptive roles of genes exchanged through this mechanism. Our results also revealed that the extent of genetic exchange correlated with lifestyle and some genomic features. Moreover, the genes in exchanged regions were enriched for functions that reflected specific adaptations, supporting identification of HR as one of the main evolutionary mechanisms shaping prokaryotic core genomes.
Microbial populations exchange genetic material through a process called homologous recombination. Although this process has been studied in particular organisms, we lack an understanding of its differential impact over the genome and across microbes with different life-styles. We used a common analytical framework to assess this process in a representative set of microorganisms. Our results uncovered important trends. First, microbes with different lifestyles are differentially impacted, with endosymbionts and obligate pathogens being those less prone to undergo this process. Second, certain genetic elements such as restriction-modification systems seem to be associated with higher rates of recombination. Most importantly, recombined genomes show the footprints of natural selection in which recombined regions preferentially contain genes that can be related to specific ecological adaptations. Taken together, our results clarify the relative contributions of factors modulating homologous recombination and show evidence for a clear a role of this process in shaping microbial genomes and driving ecological adaptations.
Changes in bacterial assemblages along an environmental gradient determined by the distance to aquaculture installations were analysed, using denaturing gradient gel electrophoresis to assess the ...influence of fish farming on marine sediments. Our findings show that changes in the structure of the bacterial community are a useful indicator for determining the environmental impact of aquaculture farms, due to the rapid response to changes in nutrient load, and could be an alternative strategy for monitoring programmes. Delta and Epsilonproteobacteria linked to the sulphur cycle were detected in the sediments beneath the cages. Since these groups were not found in the sediments at control stations, they serve as indicators for assessing the impact of the organic load from fish farming on marine sediments.
•Changes in bacterial communities from sediments beneath aquaculture installations were detected using denaturing gradient gel electrophoresis.•Changes in bacterial community stuctures, due to their rapid response to changes in nutrient load, are a useful indicator for determining the environmental impact of aquaculture farms.•Delta and Epsilonproteobacteria linked to sulphur cycle are a useful indicator for assessing the impact of fish farming over the marine sediment.•Sediments beneath fish farms could be an important reservoir for Vibrio fish pathogens, potentially disseminating the pathogens across large geographic areas, in addition to being infection vectors.
In Antarctic coastal waters where nutrient limitations are low, viruses are expected to play a major role in the regulation of bloom events. Despite this, research in viral identification and ...dynamics is scarce, with limited information available for the Southern Ocean (SO). This study presents an integrative-omics approach, comparing variation in the viral and microbial active communities on two contrasting sample conditions from a diatom-dominated phytoplankton bloom occurring in Chile Bay in the West Antarctic Peninsula (WAP) in the summer of 2014. The known viral community, initially dominated by Myoviridae family (∼82% of the total assigned reads), changed to become dominated by Phycodnaviridae (∼90%), while viral activity was predominantly driven by dsDNA members of the Phycodnaviridae (∼50%) and diatom infecting ssRNA viruses (∼38%), becoming more significant as chlorophyll
increased. A genomic and phylogenetic characterization allowed the identification of a new viral lineage within the Myoviridae family. This new lineage of viruses infects
and was dominant in the phage community. In addition, a new Phycodnavirus (PaV) was described, which is predicted to infect
, the main blooming haptophyte in the SO. This work was able to identify the changes in the main viral players during a bloom development and suggests that the changes observed in the virioplankton could be used as a model to understand the development and decay of blooms that occur throughout the WAP.
The phylum
comprises mainly uncultured microorganisms that inhabit different environments such as soils, freshwater lakes, marine sediments, sponges, or corals. Based on 16S rRNA gene studies, the ...group PAUC43f is one of the most frequently retrieved
in marine samples. However, its physiology and ecological roles are completely unknown since, to date, not a single PAUC43f isolate or metagenome-assembled genome (MAG) has been characterized. Here, we carried out a broad study of the distribution, abundance, ecotaxonomy, and metabolism of PAUC43f, for which we propose the name of
. This group was detected in 4,965 16S rRNA gene amplicon datasets, mainly from marine sediments, sponges, corals, soils, and lakes, reaching up to 34.3% relative abundance, which highlights its cosmopolitan character, mainly salt-related. The potential metabolic capabilities inferred from 52
MAGs recovered from marine sediments, sponges, and saline soils suggested a facultative aerobic and chemoorganotrophic metabolism, although some members may also oxidize hydrogen. Some
species might also play an environmental role as N
O consumers as well as suppliers of serine and thiamine. When compared to the rest of the
phylum, the biosynthesis of thiamine was one of the key features of the
. Finally, we show that polysaccharide utilization loci (PUL) are widely distributed within the
so that they are not restricted to
, as previously thought. Our results expand the knowledge about this cryptic phylum and provide new insights into the ecological roles of the
in the environment. IMPORTANCE Despite advances in molecular and sequencing techniques, there is still a plethora of unknown microorganisms with a relevant ecological role. In the last years, the mostly uncultured
phylum is attracting scientific interest because of its widespread distribution and abundance, but very little is known about its ecological role in the marine ecosystem. Here we analyze the global distribution and potential metabolism of the marine
group PAUC43f, for which we propose the name of
order. This group presents a saline-related character and a chemoorganoheterotrophic and facultatively aerobic metabolism, although some species might oxidize H
. Given that
is potentially able to synthesize thiamine, whose auxotrophy is the second most common in the marine environment, we propose
as a key thiamine supplier to the marine communities. This finding suggests that
could have a more relevant role in the marine environment than previously thought.
Microbial communities thriving in hypersaline brines of solar salterns are highly resistant and resilient to environmental changes, and salinity is a major factor that deterministically influences ...community structure. Here, we demonstrate that this resilience occurs even after rapid osmotic shocks caused by a threefold change in salinity (a reduction from 34 to 12% salts) leading to massive amounts of archaeal cell lysis. Specifically, our temporal metagenomic datasets identified two co-occurring ecotypes within the most dominant archaeal population of the brines Haloquadratum walsbyi that exhibited different salt concentration preferences. The dominant ecotype was generally more abundant and occurred in high-salt conditions (34%); the low abundance ecotype always co-occurred but was enriched at salinities around 20% or lower and carried unique gene content related to solute transport and gene regulation. Despite their apparent distinct ecological preferences, the ecotypes did not outcompete each other presumably due to weak functional differentiation between them. Further, the osmotic shock selected for a temporal increase in taxonomic and functional diversity at both the Hqr. walsbyi population and whole-community levels supporting the specialization-disturbance hypothesis, that is, the expectation that disturbance favors generalists. Altogether, our results provide new insights into how intraspecies diversity is maintained in light of substantial gene-content differences and major environmental perturbations.
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