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1.
Microbiol Resour Announc ; : e0034224, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38860812

ABSTRACT

We purified a lytic bacteriophage from soil collected in Guasave, Sinaloa: phiExGM16. This bacteriophage was isolated using the host, Exigoubacterium acetilycum. Its 17.6 kb genome contains 33 putative genes and shows a cover of 64% with 76.37% of nucleotide identity to Microbacterium phage Noelani.

2.
Sensors (Basel) ; 24(9)2024 May 03.
Article in English | MEDLINE | ID: mdl-38733026

ABSTRACT

In this paper, a six-degree-of-freedom analog tactile probe with a new, simple, and robust mechanical design is presented. Its design is based on the use of one elastomeric ring that supports the stylus carrier and allows its movement inside a cubic measuring range of ±3 mm. The position of the probe tip is determined by three low-cost, noncontact, 2D PSD (position-sensitive detector) sensors, facilitating a wider application of this probe to different measuring systems compared to commercial ones. However, several software corrections, regarding the size and orientation of the three LED light beams, must be carried out when using these 2D sensors for this application due to the lack of additional focusing or collimating lenses and the very wide measuring range. The development process, simulation results, correction models, experimental tests, and calibration of this probe are presented. The results demonstrate high repeatability along the X-, Y-, and Z-axes (2.0 µm, 2.0 µm, and 2.1 µm, respectively) and overall accuracies of 6.7 µm, 7.0 µm, and 8.0 µm, respectively, which could be minimized by more complex correction models.

3.
Microorganisms ; 12(5)2024 May 03.
Article in English | MEDLINE | ID: mdl-38792761

ABSTRACT

The competitive colonization of bacteria on similar ecological niches has a significant impact during their establishment. The synthesis speeds of different chemical classes of molecules during early competitive colonization can reduce the number of competitors through metabolic effects. In this work, we demonstrate for the first time that Kosakonia cowanii Cp1 previously isolated from the seeds of Capsicum pubescens R. P. produced volatile organic compounds (VOCs) during competitive colonization against Pectobacterium aroidearum SM2, affecting soft rot symptoms in serrano chili (Capsicum annuum L.). The pathogen P. aroidearum SM2 was isolated from the fruits of C. annuum var. Serrano with soft rot symptoms. The genome of the SM2 strain carries a 5,037,920 bp chromosome with 51.46% G + C content and 4925 predicted protein-coding genes. It presents 12 genes encoding plant-cell-wall-degrading enzymes (PCDEWs), 139 genes involved in five types of secretion systems, and 16 genes related to invasion motility. Pathogenic essays showed soft rot symptoms in the fruits of C. annuum L., Solanum lycopersicum, and Physalis philadelphica and the tubers of Solanum tuberosum. During the growth phases of K. cowanii Cp1, a mix of VOCs was identified by means of HS-SPME-GC-MS. Of these compounds, 2,5-dimethyl-pyrazine showed bactericidal effects and synergy with acetoin during the competitive colonization of K. cowanii Cp1 to completely reduce soft rot symptoms. This work provides novel evidence grounding a better understanding of bacterial interactions during competitive colonization on plant tissue, where VOC synthesis is essential and has a high potential capacity to control pathogenic microorganisms in agricultural systems.

4.
Microbiol Resour Announc ; 13(6): e0030224, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38700345

ABSTRACT

We characterized the complete genome sequence of phiMiGM15, a lytic bacteriophage with siphovirus morphology that infects Microbacterium enclense. Its 48.6 kb genome contains 81 putative genes and shows coverage of 28% with 82.26% of nucleotide identity to Microbacterium phage Caron accession number OQ190481.1.

5.
Curr Microbiol ; 81(7): 200, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38822158

ABSTRACT

Grapevine production is economically indispensable for the global wine industry. Currently, Mexico cultivates grapevines across approximately 28 500 hectares, ranking as the 26th largest producer worldwide. Given its significance, early detection of plant diseases' causal agents is crucial for preventing outbreaks. Consequently, our study aimed to identify fungal strains in grapevines exhibiting trunk disease symptoms and assess their enzymatic capabilities as indicators of their phytopathogenic potential. We collected plant cultivars, including Malbec, Shiraz, and Tempranillo, from Querétaro, Mexico. In the laboratory, we superficially removed the plant bark to prevent external contamination. Subsequently, the sample was superficially disinfected, and sawdust was generated from the symptomatic tissue. Cultivable fungal strains were isolated using aseptic techniques from the recovered sawdust. Colonies were grown on PDA and identified through a combination of microscopy and DNA-sequencing of the ITS and LSU nrDNA regions, coupled with a BLASTn search in the GenBank database. We evaluated the strains' qualitative ability to degrade cellulose, starch, and lignin using specific media and stains. Using culture morphology and DNA-sequencing, 13 species in seven genera were determined: Acremonium, Aspergillus, Cladosporium, Dydimella, Fusarium, Sarocladium, and Quambalaria. Some isolated strains were able to degrade cellulose or lignin, or starch. These results constitute the first report of these species community in the Americas. Using culture-dependent and DNA-sequencing tools allows the detection of fungal strains to continue monitoring for early prevention of the GTD.


Subject(s)
DNA, Fungal , Fungi , Plant Diseases , Vitis , Vitis/microbiology , Mexico , Plant Diseases/microbiology , DNA, Fungal/genetics , Fungi/genetics , Fungi/isolation & purification , Fungi/classification , Fungi/enzymology , Phylogeny , Sequence Analysis, DNA , Cellulose/metabolism , Lignin/metabolism
6.
J Physiol ; 602(7): 1405-1426, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38457332

ABSTRACT

Ocular Surface (OS) somatosensory innervation detects external stimuli producing perceptions, such as pain or dryness, the most relevant symptoms in many OS pathologies. Nevertheless, little is known about the central nervous system circuits involved in these perceptions, and how they integrate multimodal inputs in general. Here, we aim to describe the thalamic and cortical activity in response to OS stimulation of different modalities. Electrophysiological extracellular recordings in anaesthetized rats were used to record neural activity, while saline drops at different temperatures were applied to stimulate the OS. Neurons were recorded in the ophthalmic branch of the trigeminal ganglion (TG, 49 units), the thalamic VPM-POm nuclei representing the face (Th, 69 units) and the primary somatosensory cortex (S1, 101 units). The precise locations for Th and S1 neurons receiving OS information are reported here for the first time. Interestingly, all recorded nuclei encode modality both at the single neuron and population levels, with noxious stimulation producing a qualitatively different activity profile from other modalities. Moreover, neurons responding to new combinations of stimulus modalities not present in the peripheral TG subsequently appear in Th and S1, being organized in space through the formation of clusters. Besides, neurons that present higher multimodality display higher spontaneous activity. These results constitute the first anatomical and functional characterization of the thalamocortical representation of the OS. Furthermore, they provide insight into how information from different modalities gets integrated from the peripheral nervous system into the complex cortical networks of the brain. KEY POINTS: Anatomical location of thalamic and cortical ocular surface representation. Thalamic and cortical neuronal responses to multimodal stimulation of the ocular surface. Increasing functional complexity along trigeminal neuroaxis. Proposal of a new perspective on how peripheral activity shapes central nervous system function.


Subject(s)
Thalamic Nuclei , Thalamus , Rats , Animals , Thalamus/physiology , Thalamic Nuclei/physiology , Neurons/physiology , Pain , Face , Somatosensory Cortex/physiology
7.
STAR Protoc ; 5(2): 102972, 2024 Mar 18.
Article in English | MEDLINE | ID: mdl-38502685

ABSTRACT

Studies on sensory information processing typically focus on whisker-related tactile information, overlooking the question of how sensory inputs from other body areas are processed at cortical levels. Here, we present a protocol for stimulating specific rodent limb receptive fields while recording in vivo somatosensory-evoked activity. We describe steps for localizing cortical-hindlimb coordinates using acute peripheral stimulation, electrode placement, and the application of electrical stimulation. This protocol overcomes the challenge of inducing a reproducible and consistent stimulation of specific limbs. For complete details on the use and execution of this protocol, please refer to Miguel-Quesada et al.1.

8.
Antibiotics (Basel) ; 13(2)2024 Feb 13.
Article in English | MEDLINE | ID: mdl-38391568

ABSTRACT

Chili powder is an important condiment around the world. However, according to various reports, the presence of pathogenic microorganisms could present a public health risk factor during its consumption. Therefore, microbiological quality assessment is required to understand key microbial functional traits, such as antibiotic resistance genes (ARGs). In this study, metagenomic next-generation sequencing (mNGS) and bioinformatics analysis were used to characterize the comprehensive profiles of the bacterial community and antibiotic resistance genes (ARGs) in 15 chili powder samples from different regions of Mexico. The initial bacterial load showed aerobic mesophilic bacteria (AMB) ranging between 6 × 103 and 7 × 108 CFU/g, sporulated mesophilic bacteria (SMB) from 4.3 × 103 to 2 × 109 CFU/g, and enterobacteria (En) from <100 to 2.3 × 106 CFU/g. The most representative families in the samples were Bacillaceae and Enterobacteriaceae, in which 18 potential pathogen-associated species were detected. In total, the resistome profile in the chili powder contained 68 unique genes, which conferred antibiotic resistance distributed in 13 different classes. Among the main classes of antibiotic resistance genes with a high abundance in almost all the samples were those related to multidrug, tetracycline, beta-lactam, aminoglycoside, and phenicol resistance. Our findings reveal the utility of mNGS in elucidating microbiological quality in chili powder to reduce the public health risks and the spread of potential pathogens with antibiotic resistance mechanisms.

9.
Children (Basel) ; 10(12)2023 Nov 21.
Article in English | MEDLINE | ID: mdl-38136033

ABSTRACT

The municipality of Salvador, situated in Brazil, distinguished itself as the epicenter of the emergence of microcephaly related to congenital manifestations of Zika syndrome. Despite the anticipated significant developmental setbacks in these children, research has indicated a varied range of outcomes, with certain instances even reflecting minimal developmental delay. Our objective was to pinpoint determinants that could forecast developmental anomalies in children diagnosed with microcephaly associated with congenital Zika syndrome (CZS). METHODOLOGY: A forward-looking clinical and neurodevelopmental examination was conducted focusing on neonates diagnosed with microcephaly with CZS, birthed between September 2015 and April 2016 at the Hospital Geral Roberto Santos, in Salvador city. That infants were monitored up to their third year by a multiprofessional team. Child development was assessed using the composite Bayley III score. Undertaken by two blinded experts, cranial CT scan analysis was performed during the neonate period for the detection of brain abnormalities and to quantify ventricle enlargement, measured by Evans' index (EI). RESULTS: Fifty newborns were evaluated with a median head circumference of 28 cm (interquartile range 27-31 cm). EI was associated with neurodevelopmental delay at three years and remained significant after adjustment for head circumference. A 0.1-point increase in EI was associated with a delay of 3.2 months in the receptive language (p = 0.016), 3.4 months in the expressive language (p = 0.016), 3.4 months in the cognitive (p = 0.016), 2.37 months in the gross motor (p = 0.026), and 3.1 months in the fine motor (p = 0.021) domains. CONCLUSIONS: EI predicted neurodevelopmental delay in all Bayley domains in children with microcephaly associated with CZS.

10.
Injury ; 54 Suppl 6: 110720, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38143143

ABSTRACT

INTRODUCTION: Open tibial plateau fractures are complex injuries that require specialized management to prevent complications. The objective of this study was to compare the infection risk and functional outcomes between open and closed tibial plateau fractures. MATERIALS AND METHODS: In this multicenter cohort study the propensity score matching was used to pair participants according to age, sex, and Schatzker classification. 190 patients were followed for 1 year postoperatively. The Fracture-Related Infection (FRI) Consensus Group criteria was used to diagnose infection. Knee functionality was measured using the Oxford Knee Score scale (OKS). RESULTS: The proportion of open fractures was 5.1%, and the overall incidence rate of FRI was 8% with 14% of them represented by open fractures and 4% for closed fractures (p = 0.014). Open fractures were found to be a risk factor associated with FRI, with a 5.48 times higher probability of FRI than closed fractures (odds ratio 5.41, 95% confidence interval [CI] 1.55-18.85). Among the study population, 50% had satisfactory functional outcomes of the knee (median OKS 45, IQR = 3). The median OKS was 44 (IQR = 11) in open fractures and 46 (IQR = 7) in closed ones (p = 0.03). Multivariate analysis showed that the OKS was 3 points lower for open fractures (95% CI -5.530--0.478) than closed ones, and the score was 9.7 points lower for FRI. CONCLUSION: Open TPF is a risk factor that increases the probability of fracture related infections. Functional outcomes were excellent for both open and closed TPF, with a slight difference numerical that was under the minimal clinical difference (MCID). The presence of FRI significantly decreases the functional outcome.


Subject(s)
Fractures, Closed , Fractures, Open , Tibial Fractures , Tibial Plateau Fractures , Humans , Fractures, Open/surgery , Cohort Studies , Fracture Fixation, Internal , Tibial Fractures/surgery , Retrospective Studies , Treatment Outcome
11.
Biomedicines ; 11(11)2023 Nov 20.
Article in English | MEDLINE | ID: mdl-38002094

ABSTRACT

The transition metal characteristics of iron allow it to play a fundamental role in several essential aspects of human life such as the transport of oxygen through hemoglobin or the transport of electrons in the mitochondrial respiratory chain coupled to the synthesis of ATP. However, an excess or deficiency of iron is related to certain pathologies. The maintenance of iron homeostasis is essential to avoid certain pathologies related to iron excess or deficiency. The existence of iron deposits in postmortem tissues of Parkinson's patients has been interpreted as evidence that iron plays a fundamental role in the degenerative process of the nigrostriatal system in this disease. The use of iron chelators has been successful in the treatment of diseases such as transfusion-dependent thalassemia and pantothenate kinase-associated neurodegeneration. However, a clinical study with the iron chelator deferiprone in patients with Parkinson's disease has not shown positive effects but rather worsened clinical symptoms. This suggests that iron may not play a role in the degenerative process of Parkinson's disease.

12.
Biomed Pharmacother ; 168: 115712, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37871556

ABSTRACT

BACKGROUND: In both clinical and experimental trials, pirfenidone (PFD) showed anti-inflammatory and antifibrogenic effects. Considering the wide variation in hepatic functional reserve in patients with cirrhosis, we decided to learn more about the pharmacokinetics of a new formulation of prolonged release PFD in this population (PR-PFD), focusing on assessing changes on AUC0-∞, AUC0-t, and Cmax. METHODS: In this study, 24 subjects with cirrhosis were included: eight subjects with mild liver impairment (Child-Pugh A) and eight with moderate liver impairment (Child-Pugh B), and a third group of eight age-matched subjects without fibrosis. All participants were under fasting conditions before receiving orally two 600-mg tablets of a prolonged-release formulation of pirfenidone (PR-PFD) and remained in the clinical unit for 36 h after PR-PFD administration. Serial blood samples were collected after dosing (0.5-36 h). A validated high-performance liquid chromatography-mass spectrometry method was used to determine PFD plasma concentrations. RESULTS: The exposure to PR-PFD was 3.6- and 4.4-fold greater in subjects with Child-Pugh A and Child-Pugh B than in subjects without cirrhosis, and Cmax was 1.6- and 1.8-fold greater in subjects with Child-Pugh B and Child-Pugh-A than in patients without cirrhosis, without significant differences between the two cirrhotic groups. PFD was well tolerated. CONCLUSION: The pharmacokinetic parameters of PR-PFD are significantly modified in patients with cirrhosis compared with those in controls, indicating that liver impairment should be considered in clinical practice.


Subject(s)
Liver Cirrhosis , Liver Diseases , Humans , Liver Cirrhosis/drug therapy , Liver Diseases/drug therapy , Pyridones/therapeutic use , Area Under Curve
13.
Chem Sci ; 14(41): 11389-11401, 2023 Oct 25.
Article in English | MEDLINE | ID: mdl-37886106

ABSTRACT

Pathway complexity results in unique materials from the same components according to the assembly conditions. Here a chiral acyl-semicarbazide gelator forms three different gels of contrasting fibre morphology (termed 'gelmorphs') as well as lyotropic liquid crystalline droplets depending on the assembly pathway. The gels have morphologies that are either hyperhelical (HH-Gel), tape-fibre (TF-Gel) or thin fibril derived from the liquid crystalline phase (LC-Gels) and exhibit very different rheological properties. The gelator exists as three slowly interconverting conformers in solution. All three gels are comprised of an unsymmetrical, intramolecular hydrogen bonded conformer. The kinetics show that formation of the remarkable HH-Gel is cooperative and is postulated to involve association of the growing fibril with a non-gelling conformer. This single molecule dynamic conformational library shows how very different materials with different morphology and hence very contrasting materials properties can arise from pathway complexity as a result of emergent interactions during the assembly process.

15.
Chem Commun (Camb) ; 59(79): 11753-11766, 2023 Oct 04.
Article in English | MEDLINE | ID: mdl-37703047

ABSTRACT

The recent development and implementation of copper-based metal-organic frameworks in biological applications are reviewed. The advantages of the presence of copper in MOFs for relevant applications such as drug delivery, cancer treatment, sensing, and antimicrobial are highlighted. Advanced composites such as MOF-polymers are playing critical roles in developing materials for specific applications.

16.
Rev. colomb. gastroenterol ; 38(3)sept. 2023.
Article in English | LILACS-Express | LILACS | ID: biblio-1535921

ABSTRACT

Aim: To establish the relationship between consuming foods considered risk factors for gastric cancer and trophic changes in gastric mucosa. Materials and methods: Cross-sectional study. We included patients older than 18 admitted for upper GI endoscopy with biopsies who adequately answered a survey of personal history and eating habits. Those with a history of gastric cancer or gastric surgical resection for any reason were excluded. The association between feeding variables and trophic changes in the gastric mucosa was estimated. Results: In a population of 1,096 patients, the average age was 51 years (standard deviation [SD]: 15.5), and 59% were women. Trophic changes in the gastric mucosa were identified in 173 patients (15.8%). No statistical association was found between the independent variables of eating habits, obesity, and positive Helicobacter pylori versus the variable "trophic changes," unlike the variable "family history of gastric cancer" (odds ratio [OR]: 1.49 95% confidence interval [CI]: 1.03-2.17, p = 0.036). One case of high-grade dysplasia was detected in the study population (0.91 cases in 1,000 patients). Conclusions: No association was established between eating habits and trophic changes in the gastric mucosa in the studied population. A family history of gastric cancer is a statistically significant risk factor for developing atrophy, metaplasia, or dysplasia changes.


Objetivo: establecer la relación entre el consumo de alimentos considerados como factores de riesgo para cáncer gástrico y la presencia de cambios tróficos de la mucosa gástrica. Materiales y métodos: estudio de corte transversal. Se incluyeron los pacientes mayores de 18 años admitidos para realización de endoscopia digestiva superior con toma de biopsias que respondieron adecuadamente una encuesta de antecedentes personales y hábitos de alimentación. Se excluyeron aquellos con antecedente de cáncer gástrico o resección quirúrgica gástrica por cualquier motivo. Se estimó la asociación entre las variables de alimentación y la presencia de cambios tróficos de la mucosa gástrica. Resultados: en una población de 1096 pacientes, el promedio de la edad fue 51 años (desviación estándar [DE]: 15,5), y correspondió en un 59% a mujeres. Se identificaron cambios tróficos de la mucosa gástrica en 173 pacientes (15,8%). No se obtuvo asociación estadística entre las variables independientes de hábitos de alimentación, obesidad y Helicobacter pylori positivo frente a la variable "cambios tróficos", a diferencia de la variable "antecedente familiar de cáncer gástrico" (odds ratio [OR]: 1,49; intervalo de confianza [IC] 95%: 1,03-2,17; p = 0,036). Se obtuvo 1 caso de displasia de alto grado en la población estudiada (0,91 casos en 1000 pacientes). Conclusiones: no se estableció una asociación entre los hábitos de alimentación y la presencia de cambios tróficos de la mucosa gástrica en la población estudiada. El antecedente familiar de cáncer gástrico se muestra como un factor de riesgo estadísticamente significativo para el desarrollo de cambios de atrofia, metaplasia o displasia.

17.
Exp Neurol ; 369: 114504, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37591355

ABSTRACT

The complete or partial damage of ascending somatosensory pathways produced by a spinal cord injury triggers changes in the somatosensory cortex consisting in a functional expansion of activity from intact cortical regions towards deafferented ones, a process known as cortical reorganization. However, it is still unclear whether cortical reorganization depends on the severity of the spinal cord damage or if a spinal cord injury always leads to a similar cortical reorganization process in the somatosensory cortex. To answer these open questions in the field, we obtained longitudinal somatosensory evoked responses from bilateral hindlimb and forelimb cortex from animals with chronic full-transection or contusive spinal cord injury at thoracic level (T9-T10) to induce sensory deprivation of hindlimb cortex while preserving intact the forelimb cortex. Electrophysiological recordings from the four locations were obtained before lesion and weekly for up to 4 weeks. Our results show that cortical reorganization depends on the type of spinal cord injury, which tends to be more bilateral in full transection while is more unilateral in the model of contusive spinal cord injury. Moreover, in full transection of spinal cord, the deafferented and intact cortex exhibited similar increments of somatosensory evoked responses in both models of spinal cord injury - a feature observed in about 80% of subjects. The other 20% were unaffected by the injury indicating that cortical reorganization does not undergo in all subjects. In addition, we demonstrated an increased probability of triggered up-states in animals with spinal cord injury. This data indicates increased cortical excitability that could be proposed as a new feature of cortical reorganization. Finally, decreased levels of GABA marker GAD67 across cortical layers were only found in those animals with increased somatosensory evoked responses, but not in the unaffected population. In conclusion, cortical reorganization depends on the types of spinal cord injuries, and suggest that the phenomenon is strongly determined by cortical circuits. Moreover, changes in GABAergic transmission at the deprived cortex may be considered one of the mechanisms underlying the process of cortical reorganization and increased excitability.

18.
Cell Rep ; 42(8): 112950, 2023 08 29.
Article in English | MEDLINE | ID: mdl-37543946

ABSTRACT

Cortical neuron-astrocyte communication in response to peripheral sensory stimulation occurs in a topographic-, frequency-, and intensity-dependent manner. However, the contribution of this functional interaction to the processing of sensory inputs and consequent behavior remains unclear. We investigate the role of astrocytes in sensory information processing at circuit and behavioral levels by monitoring and manipulating astrocytic activity in vivo. We show that astrocytes control the dynamic range of the cortical network activity, optimizing its responsiveness to incoming sensory inputs. The astrocytic modulation of sensory processing contributes to setting the detection threshold for tactile and thermal behavior responses. The mechanism of such astrocytic control is mediated through modulation of inhibitory transmission to adjust the gain and sensitivity of responding networks. These results uncover a role for astrocytes in maintaining the cortical network activity in an optimal range to control behavior associated with specific sensory modalities.


Subject(s)
Astrocytes , Somatosensory Cortex , Astrocytes/physiology , Neural Pathways , Calcium/metabolism , Neurons/physiology , Electrophysiology , Animals , Mice , Somatosensory Cortex/cytology , Somatosensory Cortex/physiology , Olfactory Perception , Touch Perception
19.
Microorganisms ; 11(7)2023 Jul 05.
Article in English | MEDLINE | ID: mdl-37512930

ABSTRACT

Kosakonia cowanii strain Ch1 was isolated from Mexican chili powder, and the genome was sequenced. The genome was 4,765,544 bp in length, with an average G + C content of 56.22%, and a plasmid (pCh1) of 128,063 bp with an average G + C content of 52.50%. A phylogenetic analysis revealed a close relation with pathogenic strains; nevertheless, some virulence-related genes were absent, and this genetic characteristic may explain the fact that K. cowanii Ch1 behaved as a non-pathogenic strain when infection assays were performed on the leaves and fruits of Capsicum annuum L. Surprisingly, we observed that this bacterial strain had the ability to spread throughout serrano pepper seeds. Furthermore, K. cowanii Ch1 was evaluated for the production of volatile organic compounds (VOCs) against fungal pathogens, and the results showed that Alternaria alternata and Sclerotium rolfsii were inhibited in a radial mycelial growth assay by a mean rate of 70% and 64%, while Fusarium oxysporum was inhibited by only approximately 10%. Based on the headspace solid-phase microextraction combined with the gas chromatography mass spectrometry (HS-SPME-GC-MS), 67 potential VOCs were identified during the fermentation of K. cowanii Ch1 in TSA medium. From these VOCs, nine main compounds were identified based on relative peak area: dodecanoic acid; 3-hydroxy ethanol; 1-butanol-3-methyl; acetaldehyde; butanoic acid, butyl ester; cyclodecane; 2-butanone, 3-hydroxy; disulfide, dimethyl and pyrazine-2,5-dimethyl. Our findings show the potential of K. cowanii Ch1 for the biocontrol of fungal pathogens through VOCs production and reveal additional abilities and metabolic features as beneficial bacterial specie.

20.
bioRxiv ; 2023 Jul 19.
Article in English | MEDLINE | ID: mdl-37503130

ABSTRACT

Astrocytes are active cells involved in brain function through the bidirectional communication with neurons, in which the astrocyte calcium signal plays a crucial role. Synaptically-evoked calcium increases can be localized to independent subcellular domains or expand to the entire cell, i.e., calcium surge. In turn, astrocytes may regulate individual synapses by calcium-dependent release of gliotransmitters. Because a single astrocyte may contact ~100,000 synapses, the control of the intracellular calcium signal propagation may have relevant consequences on brain function by regulating the spatial range of astrocyte neuromodulation of synapses. Yet, the properties governing the spatial dynamics of the astrocyte calcium signal remains poorly defined. Imaging subcellular responses of cortical astrocytes to sensory stimulation in mice, we show that sensory-evoked astrocyte calcium responses originated and remained localized in domains of the astrocytic arborization, but eventually propagated to the entire cell if a spatial threshold of >23% of the arborization being activated was surpassed. Using transgenic IP3R2-/- mice, we found that type-2 IP3 receptors were necessary for the generation of the astrocyte calcium surge. We finally show using in situ electrophysiological recordings that the spatial threshold of the astrocyte calcium signal consequently determined the gliotransmitter release. Present results reveal a fundamental property of astrocyte calcium physiology, i.e., a spatial threshold for the astrocyte intracellular calcium signal propagation, which depends on astrocyte intrinsic properties and governs the astrocyte integration of local synaptic activity and the subsequent neuromodulation.

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