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1.
J Appl Microbiol ; 135(5)2024 May 01.
Article in English | MEDLINE | ID: mdl-38710582

ABSTRACT

AIMS: This study aimed to evaluate the efficiency of two phages [VB_VaC_TDDLMA (phage TDD) and VB_VaC_SRILMA (phage SRI)] alone and in a cocktail to control Vibrio alginolyticus in brine shrimp before their administration in larviculture. METHODS AND RESULTS: Phages were isolated from seawater samples and characterized by host spectrum, growth parameters, adsorption rate, genomic analysis, and inactivation efficiency. Both phages belong to the Caudoviricetes class and lack known virulence or antibiotic-resistance genes. They exhibit specificity, infecting only their host, V. alginolyticus CECT 521. Preliminary experiments in a culture medium showed that phage TDD (reduction of 5.8 log CFU ml-1 after 10 h) outperformed phage SRI (reduction of 4.6 log CFU ml-1 after 6 h) and the cocktail TDD/SRI (reduction of 5.2 log CFU ml-1 after 8 h). In artificial marine water experiments with Artemia franciscana, both single phage suspensions and the phage cocktail, effectively inactivated V. alginolyticus in culture water (reduction of 4.3, 2.1, and 1.9 log CFU ml-1 for phages TDD, SRI, and the phage cocktail, respectively, after 12 h) and in A. franciscana (reduction of 51.6%, 87.3%, and 85.3% for phages TDD, SRI, and the phage cocktail, respectively, after 24 h). The two phages and the phage cocktail did not affect A. franciscana natural microbiota or other Vibrio species in the brine shrimp. CONCLUSIONS: The results suggest that phages can safely and effectively control V. alginolyticus in A. franciscana prior to its administration in larviculture.


Subject(s)
Aquaculture , Artemia , Bacteriophages , Vibrio alginolyticus , Vibrio alginolyticus/virology , Animals , Artemia/microbiology , Artemia/virology , Animal Feed , Seawater/microbiology , Larva/microbiology
2.
FEMS Microbiol Ecol ; 100(3)2024 Feb 14.
Article in English | MEDLINE | ID: mdl-38366951

ABSTRACT

Sponges are abundant components of coral reefs known for their filtration capabilities and intricate interactions with microbes. They play a crucial role in maintaining the ecological balance of coral reefs. Humic substances (HS) affect bacterial communities across terrestrial, freshwater, and marine ecosystems. However, the specific effects of HS on sponge-associated microbial symbionts have largely been neglected. Here, we used a randomized-controlled microcosm setup to investigate the independent and interactive effects of HS, elevated temperature, and UVB radiation on bacterial communities associated with the sponge Chondrilla sp. Our results indicated the presence of a core bacterial community consisting of relatively abundant members, apparently resilient to the tested environmental perturbations, alongside a variable bacterial community. Elevated temperature positively affected the relative abundances of ASVs related to Planctomycetales and members of the families Pseudohongiellaceae and Hyphomonadaceae. HS increased the relative abundances of several ASVs potentially involved in recalcitrant organic matter degradation (e.g., the BD2-11 terrestrial group, Saccharimonadales, and SAR202 clade). There was no significant independent effect of UVB and there were no significant interactive effects of HS, heat, and UVB on bacterial diversity and composition. The significant, independent impact of HS on the composition of sponge bacterial communities suggests that alterations to HS inputs may have cascading effects on adjacent marine ecosystems.


Subject(s)
Asteraceae , Isoquinolines , Porifera , Sulfonamides , Humans , Animals , Humic Substances , Ecosystem , Temperature
3.
Antibiotics (Basel) ; 13(2)2024 Feb 19.
Article in English | MEDLINE | ID: mdl-38391581

ABSTRACT

Urinary tract infections (UTIs) caused by resistant Klebsiella pneumoniae can lead to severe clinical complications and even death. An alternative treatment option for infected patients is using bacteriophages. In the present study, we isolated phage VB_KPM_KP1LMA (KP1LMA) from sewage water using a K. pneumoniae strain as a host. Whole-genome analysis indicated that the genome was a double-stranded linear 176,096-bp long DNA molecule with 41.8% GC content and did not contain virulence or antibiotic resistance genes. The inactivation potential of phage KP1LMA was assessed in broth at an MOI of 1 and 10, and a maximum inactivation of 4.9 and 5.4 log CFU/mL, respectively, was observed after 9 h. The efficacy at an MOI of 10 was also assessed in urine to evaluate the phage's performance in an acidic environment. A maximum inactivation of 3.8 log CFU/mL was observed after 9 h. The results suggest that phage KP1LMA could potentially control a UTI caused by this strain of K. pneumoniae, indicating that the same procedure can be used to control UTIs caused by other strains if new specific phages are isolated. Although phage KP1LMA has a narrow host range, in the future, efforts can be made to expand its spectrum of activity and also to combine this phage with others, potentially enabling its use against other K. pneumoniae strains involved in UTIs.

4.
J Appl Microbiol ; 134(8)2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37587019

ABSTRACT

AIMS: We aim at understanding the effect of domestication on the endophytic microbiome and metabolome of Salicornia europaea and collecting evidence on the potential role of microbial populations and metabolites in the adaptation of plants to different ecological contexts (wild vs crops). METHODS AND RESULTS: Samples were collected from a natural salt marsh (wild) and an intensive crop field (crop). High-throughput sequencing of the 16S rRNA gene, gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) were used to analyze the endophytic bacterial communities and the metabolite profiles of S. europaea roots, respectively. The elemental analysis of the plant shoots was performed by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS).Overall, significant differences were found between the microbiome of wild and cultivated plants. The later showed a higher relative abundance of the genera Erythrobacter, Rhodomicrobium, and Ilumatobacter than wild plants. The microbiome of wild plants was enriched in Marinobacter, Marixanthomonas, and Thalassospira. The metabolite profile of crop plants revealed higher amounts of saturated and non-saturated fatty acids and acylglycerols. In contrast, wild plants contained comparatively more carbohydrates and most macroelements (i.e. Na, K, Mg, and Ca). CONCLUSIONS: There is a strong correlation between plant metabolites and the endosphere microbiome of S. europaea. In wild populations, plants were enriched in carbohydrates and the associated bacterial community was enriched in genes related to primary metabolic pathways such as nitrogen metabolism and carbon fixation. The endosphere microbiome of crop plants was predicted to have higher gene counts related to pathogenesis. Crop plants also exhibited higher amounts of azelaic acid, an indicator of exposure to phytopathogens.


Subject(s)
Chenopodiaceae , Domestication , Chromatography, Liquid , RNA, Ribosomal, 16S/genetics , Tandem Mass Spectrometry , Metabolome
5.
Curr Microbiol ; 80(9): 294, 2023 Jul 22.
Article in English | MEDLINE | ID: mdl-37481620

ABSTRACT

In the present study, we compared mucus and gut-associated prokaryotic communities from seven nudibranch species with sediment and seawater from Thai coral reefs using high-throughput 16S rRNA gene sequencing. The nudibranch species were identified as Doriprismatica atromarginata (family Chromodorididae), Jorunna funebris (family Discodorididae), Phyllidiella nigra, Phyllidiella pustulosa, Phyllidia carlsonhoffi, Phyllidia elegans, and Phyllidia picta (all family Phyllidiidae). The most abundant bacterial phyla in the dataset were Proteobacteria, Tenericutes, Chloroflexi, Thaumarchaeota, and Cyanobacteria. Mucus and gut-associated communities differed from one another and from sediment and seawater communities. Host phylogeny was, furthermore, a significant predictor of differences in mucus and gut-associated prokaryotic community composition. With respect to higher taxon abundance, the order Rhizobiales (Proteobacteria) was more abundant in Phyllidia species (mucus and gut), whereas the order Mycoplasmatales (Tenericutes) was more abundant in D. atromarginata and J. funebris. Mucus samples were, furthermore, associated with greater abundances of certain phyla including Chloroflexi, Poribacteria, and Gemmatimonadetes, taxa considered to be indicators for high microbial abundance (HMA) sponge species. Overall, our results indicated that nudibranch microbiomes consisted of a number of abundant prokaryotic members with high sequence similarities to organisms previously detected in sponges.


Subject(s)
Chloroflexi , Gastropoda , Microbiota , Animals , RNA, Ribosomal, 16S/genetics , Prokaryotic Cells , Proteobacteria , Mucus , Microbiota/genetics , Seawater
6.
Microorganisms ; 11(2)2023 Feb 17.
Article in English | MEDLINE | ID: mdl-36838485

ABSTRACT

Live feed enrichments are often used in fish larvicultures as an optimized source of essential nutrients to improve larval growth and survival. In addition to this, they may also play an important role in structuring larval-associated microbial communities and may help improve their resistance to diseases. However, there is limited information available on how larval microbial communities and larviculture water are influenced by different live feed enrichments. In the present study, we investigated the effects of two commercial rotifer enrichments (ER) on turbot (Scophthalmus maximus) larval and post-larval gut-associated bacterial communities during larviculture production. We evaluated their effects on bacterial populations related to known pathogens and beneficial bacteria and their potential influence on the composition of bacterioplankton communities during larval rearing. High-throughput 16S rRNA gene sequencing was used to assess the effects of different rotifer enrichments (ER1 and ER2) on the structural diversity of bacterial communities of the whole turbot larvae 10 days after hatching (DAH), the post-larval gut 30 DAH, and the larviculture water. Our results showed that different rotifer feed enrichments were associated with significant differences in bacterial composition of turbot larvae 10 DAH, but not with the composition of larval gut communities 30 DAH or bacterioplankton communities 10 and 30 DAH. However, a more in-depth taxonomic analysis showed that there were significant differences in the abundance of Vibrionales in both 10 DAH larvae and in the 30 DAH post-larval gut fed different RE diets. Interestingly, the ER1 diet had a higher relative abundance of specific amplicon sequence variants (ASVs) related to potential Vibrio-antagonists belonging to the Roseobacter clade (e.g., Phaeobacter and Ruegeria at 10 DAH and Sulfitobacter at 30 DAH). In line with this, the diet was also associated with a lower relative abundance of Vibrio and a lower mortality. These results suggest that rotifer diets can affect colonization by Vibrio members in the guts of post-larval turbot. Overall, this study indicates that live feed enrichments can have modulatory effects on fish bacterial communities during the early stages of development, which includes the relative abundances of pathogenic and antagonist taxa in larviculture systems.

7.
Forensic Toxicol ; 41(2): 187-212, 2023 07.
Article in English | MEDLINE | ID: mdl-36604359

ABSTRACT

PURPOSE: New psychoactive substances (NPS) are not controlled under the Single Convention on Narcotic Drugs of 1961 or the 1971 Convention, but they may pose a public health threat. Knowledge of the main properties and toxicological effects of these substances is lacking. According to the current Drugs Law (Law n. 11.343/2006), the Brazilian Surveillance Agency issues directives for forbidden substances in Brazil, and structural classes of synthetic cannabinoids, cathinones, and phenylethylamines are considered illicit drugs. Considering that data on these controlled substances are scattered, the main objective of this work was to collect and organize data to generate relevant information on the toxicological properties of NPS. METHODS: We carried out a literature review collecting information on the acute, chronic, and post-mortem toxicity of these classes of NSP. We searched info in five scientific databases considering works from 2017 to 2021 and performed a statistical evaluation of the data. RESULTS: Results have shown a general lack of studies in this field given that many NPS have not had their toxicity evaluated. We observed a significant difference in the volume of data concerning acute and chronic/post-mortem toxicity. Moreover, studies on the adverse effects of polydrug use are scarce. CONCLUSIONS: More in-depth information about the main threats involving NPS use are needed.


Subject(s)
Cannabinoids , Illicit Drugs , Substance-Related Disorders , Humans , Psychotropic Drugs/adverse effects , Substance-Related Disorders/epidemiology , Illicit Drugs/toxicity , Cannabinoids/toxicity , Controlled Substances
8.
Environ Microbiome ; 17(1): 57, 2022 Nov 18.
Article in English | MEDLINE | ID: mdl-36401317

ABSTRACT

BACKGROUND: Metagenomics is an expanding field within microbial ecology, microbiology, and related disciplines. The number of metagenomes deposited in major public repositories such as Sequence Read Archive (SRA) and Metagenomic Rapid Annotations using Subsystems Technology (MG-RAST) is rising exponentially. However, data mining and interpretation can be challenging due to mis-annotated and misleading metadata entries. In this study, we describe the Marine Metagenome Metadata Database (MarineMetagenomeDB) to help researchers identify marine metagenomes of interest for re-analysis and meta-analysis. To this end, we have manually curated the associated metadata of several thousands of microbial metagenomes currently deposited at SRA and MG-RAST. RESULTS: In total, 125 terms were curated according to 17 different classes (e.g., biome, material, oceanic zone, geographic feature and oceanographic phenomena). Other standardized features include sample attributes (e.g., salinity, depth), sample location (e.g., latitude, longitude), and sequencing features (e.g., sequencing platform, sequence count). MarineMetagenomeDB version 1.0 contains 11,449 marine metagenomes from SRA and MG-RAST distributed across all oceans and several seas. Most samples were sequenced using Illumina sequencing technology (84.33%). More than 55% of the samples were collected from the Pacific and the Atlantic Oceans. About 40% of the samples had their biomes assigned as 'ocean'. The 'Quick Search' and 'Advanced Search' tabs allow users to use different filters to select samples of interest dynamically in the web app. The interactive map allows the visualization of samples based on their location on the world map. The web app is also equipped with a novel download tool (on both Windows and Linux operating systems), that allows easy download of raw sequence data of selected samples from their respective repositories. As a use case, we demonstrated how to use the MarineMetagenomeDB web app to select estuarine metagenomes for potential large-scale microbial biogeography studies. CONCLUSION: The MarineMetagenomeDB is a powerful resource for non-bioinformaticians to find marine metagenome samples with curated metadata and stimulate meta-studies involving marine microbiomes. Our user-friendly web app is publicly available at https://webapp.ufz.de/marmdb/ .

9.
Microbiol Res ; 265: 127183, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36108440

ABSTRACT

Plasmid-mediated transfer of genes can have direct consequences in several biological processes within sponge microbial communities. However, very few studies have attempted genomic and functional characterization of plasmids from marine host-associated microbial communities in general and those of sponges in particular. In the present study, we used an endogenous plasmid isolation method to obtain plasmids from bacterial symbionts of the marine sponges Stylissa carteri and Paratetilla sp. and investigated the genomic composition, putative ecological relevance and biotechnological potential of these plasmids. In total, we isolated and characterized three complete plasmids, three plasmid prophages and one incomplete plasmid. Our results highlight the importance of plasmids to transfer relevant genetic traits putatively involved in microbial symbiont adaptation and host-microbe and microbe-microbe interactions. For example, putative genes involved in bacterial response to chemical stress, competition, metabolic versatility and mediation of bacterial colonization and pathogenicity were detected. Genes coding for enzymes and toxins of biotechnological potential were also detected. Most plasmid prophage coding sequences were, however, hypothetical proteins with unknown functions. Overall, this study highlights the ecological relevance of plasmids in the marine sponge microbiome and provides evidence that plasmids of sponge bacterial symbionts may represent an untapped resource of genes of biotechnological interest.


Subject(s)
Porifera , Animals , Bacteria/genetics , Genomics , Phylogeny , Plasmids/genetics , Porifera/microbiology
10.
Mol Ecol ; 31(19): 4932-4948, 2022 10.
Article in English | MEDLINE | ID: mdl-35881675

ABSTRACT

Understanding the maintenance and origin of beta diversity is a central topic in ecology. However, the factors that drive diversity patterns and underlying processes remain unclear, particularly for host-prokaryotic associations. Here, beta diversity patterns were studied in five prokaryotic biotopes, namely, two high microbial abundance (HMA) sponge taxa (Xestospongia spp. and Hyrtios erectus), one low microbial abundance (LMA) sponge taxon (Stylissa carteri), sediment and seawater sampled across thousands of kilometres. Using multiple regression on distance matrices (MRM), spatial (geographic distance) and environmental (sea surface temperature and chlorophyll α concentrations) variables proved significant predictors of beta diversity in all five biotopes and together explained from 54% to 82% of variation in dissimilarity of both HMA species, 27% to 43% of variation in sediment and seawater, but only 20% of variation of the LMA S. carteri. Variance partitioning was subsequently used to partition the variation into purely spatial, purely environmental and spatially-structured environmental components. The amount of variation in dissimilarity explained by the purely spatial component was lowest for S. carteri at 11% and highest for H. erectus at 55%. The purely environmental component, in turn, only explained from 0.15% to 2.83% of variation in all biotopes. In addition to spatial and environmental variables, a matrix of genetic differences between pairs of sponge individuals also proved a significant predictor of variation in prokaryotic dissimilarity of the Xestospongia species complex. We discuss the implications of these results for the HMA-LMA dichotomy and compare the MRM results with results obtained using constrained ordination and zeta diversity.


Subject(s)
Biodiversity , Porifera , Animals , Bacteria/genetics , Chlorophyll , Humans , Phylogeny , Porifera/genetics , RNA, Ribosomal, 16S/genetics , Seawater
11.
Microbiol Resour Announc ; 11(6): e0015522, 2022 Jun 16.
Article in English | MEDLINE | ID: mdl-35587780

ABSTRACT

Here, we report on the draft genome sequence of Vibrio mediterranei strain CyArs1, isolated from the marine sponge Cinachyrella sp. Genome annotation revealed multiple genomic features, including eukaryotic-like repeat protein- and multidrug resistance-encoding genes, potentially involved in symbiotic relationships with the sponge host.

12.
Mar Drugs ; 21(1)2022 Dec 30.
Article in English | MEDLINE | ID: mdl-36662207

ABSTRACT

Marine microbiomes are prolific sources of bioactive natural products of potential pharmaceutical value. This study inspected two culture collections comprising 919 host-associated marine bacteria belonging to 55 genera and several thus-far unclassified lineages to identify isolates with potentially rich secondary metabolism and antimicrobial activities. Seventy representative isolates had their genomes mined for secondary metabolite biosynthetic gene clusters (SM-BGCs) and were screened for antimicrobial activities against four pathogenic bacteria and five pathogenic Candida strains. In total, 466 SM-BGCs were identified, with antimicrobial peptide- and polyketide synthase-related SM-BGCs being frequently detected. Only 38 SM-BGCs had similarities greater than 70% to SM-BGCs encoding known compounds, highlighting the potential biosynthetic novelty encoded by these genomes. Cross-streak assays showed that 33 of the 70 genome-sequenced isolates were active against at least one Candida species, while 44 isolates showed activity against at least one bacterial pathogen. Taxon-specific differences in antimicrobial activity among isolates suggested distinct molecules involved in antagonism against bacterial versus Candida pathogens. The here reported culture collections and genome-sequenced isolates constitute a valuable resource of understudied marine bacteria displaying antimicrobial activities and potential for the biosynthesis of novel secondary metabolites, holding promise for a future sustainable production of marine drug leads.


Subject(s)
Anthozoa , Anti-Infective Agents , Porifera , Animals , Humans , Secondary Metabolism/genetics , Bacteria/metabolism , Porifera/genetics , Multigene Family , Candida , Anti-Infective Agents/pharmacology , Anti-Infective Agents/metabolism , Anthozoa/genetics , Phylogeny
13.
An Acad Bras Cienc ; 93(suppl 3): e20210134, 2021.
Article in English | MEDLINE | ID: mdl-34787172

ABSTRACT

Campomanesia xanthocarpa (Mart.) O. Berg is a South American fruit tree species with important ecological and medicinal properties, which remnants are currently found mainly in isolated forest fragments. In this study, SSR markers from three different genomic origins (gene-linked, nuclear neutral, and organellar) were used to evaluate the patterns of genetic diversity, fine-scale spatial genetic structure and historical gene flow in fragmented forest formations of C. xanthocarpa from the Atlantic Forest in southern Brazil. Our results show that the forest fragments present moderate to high levels of genetic diversity in comparison to species presenting similar life traits, although a trend opposite to expected was observed concerning gene-linked and neutral SSR markers. The fine-scale spatial genetic structure revealed different patterns in short and large distance classes, with a distinct influence of gene-linked and neutral markers in driving the genetic structure in each distance class. The presence of an isolation-by-adaptation pattern implies the need for maintenance of the current remnants to assure the conservation of the private alleles. Finally, as the genetic diversity is found predominantly within forest fragments, programs of seed collection and/or genetic rescue should prioritize a larger number of individuals within each fragment, to increase the sampled diversity.


Subject(s)
Gene Flow , Genetic Variation , Alleles , Gene Flow/genetics , Genetic Variation/genetics , Genomics , Humans , Trees/genetics
14.
Epilepsy Behav Rep ; 16: 100487, 2021.
Article in English | MEDLINE | ID: mdl-34697604

ABSTRACT

The COVID-19 pandemic has created an immense pressure on healthcare providers, resulting in a shift to remote consultations and the redeployment of healthcare workers (HCWs). We present survey data from the United Kingdom (UK) HCWs to outline how changes in healthcare provision impact clinicians' wellbeing and ability to provide adequate care. We designed an online survey to gather the experiences of HCWs providing care to people with epilepsy. We received seventy-nine responses from UK-based HCWs, of whom 43% reported an impact on their mental health. Changes to service delivery have resulted in 71% of clinicians performing > 75% of their consultations remotely. Diagnosing and treating epilepsy has changed, with a fifth of respondents being significantly less confident in diagnosing epilepsy. Ultimately, these results show that COVID-19 has had an overall negative impact on HCWs and their ability to provide epilepsy care. These results must be considered when reorganizing health services to ensure optimal outcomes for people with epilepsy.

15.
Mol Ecol Resour ; 21(1): 110-121, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32866335

ABSTRACT

Plasmid transfers among bacterial populations can directly influence the ecological adaptation of these populations and their interactions with host species and environment. In this study, we developed a selective multiply-primed rolling circle amplification (smRCA) approach to enrich and characterize circular plasmid DNA from sponge microbial symbionts via high-throughput sequencing (HTS). DNA (plasmid and total community DNA) obtained from sponge (Cinachyrella sp.) samples and a bacterial symbiont (Vibrio sp. CyArs1) isolated from the same sponge species (carrying unknown plasmids) were used to develop and validate our methodology. The smRCA was performed during 16 hr with 141 plasmid-specific primers covering all known circular plasmid groups. The amplified products were purified and subjected to a reamplification with random hexamer primers (2 hr) and then sequenced using Illumina MiSeq. The developed method resulted in the successful amplification and characterization of the sponge plasmidome and allowed us to detect plasmids associated with the bacterial symbiont Vibrio sp. CyArs1 in the sponge host. In addition to this, a large number of small (<2 kbp) and cryptic plasmids were also amplified in sponge samples. Functional analysis identified proteins involved in the control of plasmid partitioning, maintenance and replication. However, most plasmids contained unknown genes, which could potentially serve as a resource of unknown genetic information and novel replication systems. Overall, our results indicate that the smRCA-HTS approach developed here was able to selectively enrich and characterize plasmids from bacterial isolates and sponge host microbial communities, including plasmids larger than 20 kbp.


Subject(s)
Bacteria/classification , DNA, Circular , Nucleic Acid Amplification Techniques , Plasmids/genetics , Porifera/microbiology , Animals , Base Sequence , DNA Primers , DNA, Bacterial/genetics , DNA, Circular/genetics
16.
Annu Rev Anim Biosci ; 9: 423-452, 2021 02 16.
Article in English | MEDLINE | ID: mdl-33256435

ABSTRACT

Aquaculture is the fastest-growing sector in food production worldwide. For decades, research on animal physiology, nutrition, and behavior established the foundations of best practices in land-based fish rearing and disease control. Current DNA sequencing, bioinformatics, and data science technologies now allow deep investigations of host-associated microbiomes in a tractable fashion. Adequate use of these technologies can illuminate microbiome dynamics and aid the engineering of microbiome-based solutions to disease prevention in an unprecedented manner. This review examines molecular studies of bacterial diversity, function, and host immunitymodulation at early stages of fish development, where microbial infections cause important economic losses. We uncover host colonization and virulence factors within a synthetic assemblage of fish pathogens using high-end comparative genomics and address the use of probiotics and paraprobiotics as applicable disease-prevention strategies in fish larval and juvenile rearing. We finally propose guidelines for future microbiome research of presumed relevance to fish larviculture.


Subject(s)
Aquaculture/methods , Fish Diseases/microbiology , Probiotics , Animals , Bacteria/pathogenicity , Bacterial Physiological Phenomena , Fish Diseases/immunology , Fish Diseases/prevention & control , Fishes/growth & development , Fishes/microbiology , Larva/microbiology , Microbiota
17.
Phys Rev Lett ; 125(23): 233601, 2020 Dec 04.
Article in English | MEDLINE | ID: mdl-33337227

ABSTRACT

Despite the several novel features arising from the dissipative optomechanical coupling, such effect remains vastly unexplored due to the lack of a simple formalism that captures non-Hermiticity in the engineering of optomechanical systems. In this Letter, we show that quasinormal-mode-based perturbation theory is capable of correctly predicting both dispersive and dissipative optomechanical couplings. We validate our model through simulations and also by comparison with experimental results reported in the literature. Finally, we apply this formalism to plasmonic systems, used for molecular optomechanics, where strong dissipative coupling signatures in the amplification of vibrational modes could be observed.

18.
Article in English | MEDLINE | ID: mdl-32156011

ABSTRACT

Hydrocarbon bioremediation in anoxic sediment layers is still challenging not only because it involves metabolic pathways with lower energy yields but also because the production of biosurfactants that contribute to the dispersion of the pollutant is limited by oxygen availability. This work aims at screening populations of culturable hydrocarbonoclastic and biosurfactant (BSF) producing bacteria from deep sub-seafloor sediments (mud volcanos from Gulf of Cadiz) and estuarine sub-surface sediments (Ria de Aveiro) for strains with potential to operate in sub-oxic conditions. Isolates were retrieved from anaerobic selective cultures in which crude oil was provided as sole carbon source and different supplements were provided as electron acceptors. Twelve representative isolates were obtained from selective cultures with deep-sea and estuary sediments, six from each. These were identified by sequencing of 16S rRNA gene fragments belonging to Pseudomonas, Bacillus, Ochrobactrum, Brevundimonas, Psychrobacter, Staphylococcus, Marinobacter and Curtobacterium genera. BSF production by the isolates was tested by atomized oil assay, surface tension measurement and determination of the emulsification index. All isolates were able to produce BSFs under aerobic and anaerobic conditions, except for isolate DS27 which only produced BSF under aerobic conditions. These isolates presented potential to be applied in bioremediation or microbial enhanced oil recovery strategies under conditions of oxygen limitation. For the first time, members of Ochrobactrum, Brevundimonas, Psychrobacter, Staphylococcus, Marinobacter and Curtobacterium genera are described as anaerobic producers of BSFs.


Subject(s)
Hydrocarbons , Petroleum , Surface-Active Agents , Water Pollutants, Chemical , Bacteria , Biodegradation, Environmental , Geologic Sediments , RNA, Ribosomal, 16S
19.
Compr Psychiatry ; 96: 152128, 2020 01.
Article in English | MEDLINE | ID: mdl-31715335

ABSTRACT

BACKGROUND: Antenatal maternal psychological distress is common in low and middle-income countries (LMIC), but there is a dearth of research on its effect on birth and developmental outcomes in these settings, particularly in Sub-Saharan Africa. This study set out to identify risk factors for antenatal maternal psychological distress and determine whether antenatal maternal psychological distress was associated with infant birth and developmental outcomes, using data from the Drakenstein Child Health Study (DCHS), a birth cohort study in South Africa. METHODS: Pregnant women were enrolled in the DCHS from primary care antenatal clinics. Antenatal maternal psychological distress was measured using the Self-Reporting Questionnaire 20-item (SRQ-20). A range of psychosocial measures, including maternal childhood trauma, depression, and posttraumatic stress disorder (PTSD) were administered. Birth outcomes, including premature birth, weight-for-age z-score and head circumference-for-age z-score, were measured using revised Fenton growth charts. The Bayley III Scales of Infant and Toddler Development was administered at 6 months of age to assess infant development outcomes, including cognitive, language, and motor domains in a subset of n=231. Associations of maternal antenatal psychological distress with psychosocial measures, and with infant birth and developmental outcomes were examined using linear regression models. RESULTS: 961 women were included in this analysis, with 197 (21%) reporting scores indicating the presence of psychological distress. Antenatal psychological distress was associated with maternal childhood trauma, antenatal depression, and PTSD, and inversely associated with partner support. No association was observed between antenatal maternal psychological distress and preterm birth or early developmental outcomes, but antenatal maternal psychological distress was associated with a smaller head circumference at birth (coefficient=-0.30, 95% CI: -0.49; -0.10). CONCLUSION: Antenatal maternal psychological distress is common in LMIC settings and was found to be associated with key psychosocial measures during pregnancy, as well as with adverse birth outcomes, in our study population. These associations highlight the potential value of screening for antenatal maternal psychological distress as well as of developing targeted interventions.


Subject(s)
Child Development/physiology , Pregnancy Complications/psychology , Prenatal Exposure Delayed Effects/psychology , Psychological Distress , Adult , Cohort Studies , Family , Female , Humans , Infant , Infant, Newborn , Pregnancy , Pregnancy Complications/diagnosis , Risk Factors , South Africa , Stress Disorders, Post-Traumatic/diagnosis , Stress Disorders, Post-Traumatic/psychology , Surveys and Questionnaires , Young Adult
20.
Resuscitation ; 144: 131-136, 2019 11.
Article in English | MEDLINE | ID: mdl-31580910

ABSTRACT

AIM: Each minute is crucial in the treatment of out-of-hospital cardiac arrest (CA). Immediate chest compressions and early defibrillation are keys to good outcomes. We hypothesized that a coordinated effort of alerting trained local neighborhood volunteers (vols) simultaneously with 911 activation of professional EMS providers would result in substantial decreases in call-to-arrival times, leading to earlier CPR and defibrillation. METHODS: We developed a program of simultaneously alerting CPR- and AED-trained neighborhood vols and the local EMS system for CA events in a retirement residential neighborhood in Southern Arizona, encompassing approximately 440 homes. The closest EMS station is 3.3 miles from this neighborhood. Within this neighborhood, 15 vols and the closest EMS station were involved in multiple days of mock CA notifications and responses. RESULTS: The two groups differed significantly in distance to the mock CA event and in response times. The volunteers averaged 0.3 ±â€¯0.2 miles from the mock CA incidences while the closest EMS station averaged 3.4 ±â€¯0.1 miles away (p < 0.0001). Response times (time from call to arrival) also differed. Two volunteers, one bringing an AED, averaged 1 min 38 s ±â€¯53 s in Phase 1, while it took the EMS service an average of 7 min 20 s ±â€¯1 min 13 s to arrive on scene; p < 0.0001. CONCLUSION: Local neighborhood volunteers were geographically closer and arrived significantly sooner at the mock CA scene than did the EMS service. The approximate time savings from call to arrival with the volunteers was 4-6 min.


Subject(s)
Out-of-Hospital Cardiac Arrest/therapy , Residence Characteristics , Time-to-Treatment , Volunteers , Aged , Aged, 80 and over , Arizona , Cardiopulmonary Resuscitation/education , Emergency Medical Services/organization & administration , Female , Humans , Male , Prospective Studies , Simulation Training/methods
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