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1.
Gastroenterol Rep (Oxf) ; 12: goad077, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38264764

RESUMO

Background: Since the introduction of direct-acting antivirals, thousands of chronic hepatitis C patients have been successfully treated. However, vulnerable populations have a higher prevalence of hepatitis C virus (HCV) infection and face barriers that impede their access to antivirals. We carried out an HCV microelimination program focused on vulnerable population groups in Malaga. Methods: People in drug addiction treatment centers and homeless shelters in Malaga who participated in the program between October 2020 and October 2021 were included. After providing participants with educational information on HCV, a dry drop test (DDT) was used to collect blood for subsequent screening for HCV infection. The participants who were diagnosed with HCV infection were scheduled for comprehensive healthcare assessments, including blood tests, ultrasonography, elastography, and the prescription of antivirals, all conducted in a single hospital visit. Sustained viral response (SVR) was analysed 12 weeks after end of treatment. Results: Of the 417 persons invited to participate, 271 (65%) agreed to participate in the program. These participants were screened for HCV infection and 28 of them were diagnosed with HCV infection (10%). These hepatitis C-infected patients had a mean age of 53 ± 9 years; 86% were males and 93% were or had been drug users. Among 23 patients with HCV infection, HCV genotype 1a predominated (74%). Medical exams showed that 19% (4/21) had advanced fibrosis (F3-4), and 5% (1/21) had portal hypertension. Finally, 23 infected patients received treatment with glecaprevir/pibrentasvir or sofosbuvir/velpatasvir and SVR was confirmed in 22 patients (96%). Conclusions: Drug users and homeless people have a higher prevalence of HCV infection than the general population. The microelimination program with educational activity and screening tools achieved a high participation rate, easy healthcare access, and a high rate of SVR despite the SARS-CoV-2 pandemic.

2.
Nutrients ; 14(19)2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36235746

RESUMO

The present study characterizes the oral pharmacokinetics of D-Pinitol, a natural insulin mimetic inositol, in human healthy volunteers (14 males and 11 females). D-Pinitol absorption was studied in (a) subjects receiving a single oral dose of 15 mg/kg (n = 10), or (b) 5 mg/kg pure D-Pinitol (n = 6), and (c) subjects receiving D-Pinitol as part of carbohydrate-containing carob pods-derived syrup with a 3.2% D-Pinitol (Dose of 1600 mg/subject, n = 9). The volunteers received a randomly assigned single dose of either D-Pinitol or carob pod-derived syrup. Blood samples were collected at 0, 15, 30, 45, 60, 90, 120, 180, 240, 360 and 1440 min after intake. Plasma concentration of D-Pinitol was measured and pharmacokinetic parameters obtained. The data indicate that when given alone, the oral absorption of D-Pinitol is dose-dependent and of extended duration, with a Tmax reached after almost 4 h, and a half-life greater than 5 h. When the source of D-Pinitol was a carob pods-derived syrup, Cmax was reduced to 40% of the expected based on the data of D-Pinitol alone, suggesting a reduced absorption probably because of competition with monosaccharide transport. In this group, Tmax was reached before that of D-Pinitol alone, but the estimated half-life remained the same. In the D-Pinitol groups, plasma concentrations of glucose, insulin, glucagon, ghrelin, free fatty acids, and pituitary hormones were additionally measured. A dose of 15 mg/kg of D-Pinitol did not affect glucose levels in healthy volunteers, but reduced insulin and increased glucagon and ghrelin concentrations. D-Pinitol did not increase other hormones known to enhance plasma glucose, such as cortisol or GH, which were surprisingly reduced after the ingestion of this inositol. Other pituitary hormones (gonadotropins, prolactin, and thyroid-stimulating hormone) were not affected after D-Pinitol ingestion. In a conclusion, D-Pinitol is absorbed through the oral route, having an extended half-life and displaying the pharmacological profile of an endocrine pancreas protector, a pharmacological activity of potential interest for the treatment or prevention of insulin resistance-associated conditions.


Assuntos
Fabaceae , Jejum , Glicemia , Ácidos Graxos não Esterificados , Feminino , Grelina , Glucagon , Glucose , Voluntários Saudáveis , Humanos , Hidrocortisona , Inositol/análogos & derivados , Insulina , Masculino , Prolactina , Tireotropina
3.
Sensors (Basel) ; 21(23)2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34883989

RESUMO

Investigating the coil-magnet structure plays a significant role in the design process of the electromagnetic energy harvester due to the effect on the harvester's performance. In this paper, the performance of four different electromagnetic vibration energy harvesters with cylindrical shapes constrained in the same volume were under investigation. The utilized structures are (i) two opposite polarized magnets spaced by a mild steel; (ii) a Halbach array with three magnets and one coil; (iii) a Halbach array with five magnets and one coil; and (iv) a Halbach array with five magnets and three coils. We utilized a completely automatic optimization procedure with the help of an optimization algorithm implemented in Python, supported by simulations in ANSYS Maxwell and MATLAB Simulink to obtain the maximum output power for each configuration. The simulation results show that the Halbach array with three magnets and one coil is the best for configurations with the Halbach array. Additionally, among all configurations, the harvester with two opposing magnets provides the highest output power and volume power density, while the Halbach array with three magnets and one coil provides the highest mass power density. The paper also demonstrates limitations of using the electromagnetic coupling coefficient as a metric for harvester optimization, if the ultimate goal is maximization of output power.

4.
Virulence ; 12(1): 2201-2213, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34515614

RESUMO

Acinetobacter baumannii is a pathogen of increasing clinical importance worldwide, especially given its ability to readily acquire resistance determinants. Motile strains of this bacterium can move by either or both of two types of motility: (i) twitching, driven by type IV pili, and (ii) surface-associated motility, an appendage-independent form of movement. A. baumannii strain MAR002 possesses both twitching and surface-associated motility. In this study, we isolated spontaneous rifampin-resistant mutants of strain MAR002 in which point mutations in the rpoB gene were identified that resulted in an altered motility pattern. Transcriptomic analysis of mutants lacking twitching, surface-associated motility, or both led to the identification of deregulated genes within each motility phenotype, based on their level of expression and their biological function. Investigations of the corresponding knockout mutants revealed several genes involved in the motility of A. baumannii strain MAR002, including two involved in twitching (encoding a minor pilin subunit and an RND [resistance nodulation division] component), one in surface-associated motility (encoding an amino acid permease), and eight in both (encoding RND and ABC components, the energy transducer TonB, the porin OprD, the T6SS component TagF, an IclR transcriptional regulator, a PQQ-dependent sugar dehydrogenase, and a putative pectate lyase). Virulence assays showed the reduced pathogenicity of mutants with impairments in both types of motility or in surface-associated motility alone. By contrast, the virulence of twitching-affected mutants was not affected. These results shed light on the key role of surface-associated motility and the limited role of twitching in the pathogenicity of A. baumannii.


Assuntos
Acinetobacter baumannii , Virulência , Acinetobacter baumannii/genética , Acinetobacter baumannii/patogenicidade , Proteínas de Bactérias/genética , Proteínas de Fímbrias/genética , Fímbrias Bacterianas/genética , Locomoção
5.
Sci Rep ; 11(1): 15583, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34341419

RESUMO

Cognitive reserve (CR) is the capability of an individual to cope with a brain pathology through compensatory mechanisms developed through cognitive stimulation by mental and physical activity. Recently, it has been suggested that CR has a protective role against the initiation of substance use, substance consumption patterns and cognitive decline and can improve responses to treatment. However, CR has never been linked to cognitive function and neurotrophic factors in the context of alcohol consumption. The present cross-sectional study aims to evaluate the association between CR (evaluated by educational level), cognitive impairment (assessed using a frontal and memory loss assessment battery) and circulating levels of brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) in patients with alcohol use disorder (AUD). Our results indicated that lower educational levels were accompanied by earlier onset of alcohol consumption and earlier development of alcohol dependence, as well as impaired frontal cognitive function. They also suggest that CR, NT-3 and BDNF may act as compensatory mechanisms for cognitive decline in the early stages of AUD, but not in later phases. These parameters allow the identification of patients with AUD who are at risk of cognitive deterioration and the implementation of personalized interventions to preserve cognitive function.


Assuntos
Alcoolismo/sangue , Fator Neurotrófico Derivado do Encéfalo/sangue , Disfunção Cognitiva/sangue , Escolaridade , Neurotrofina 3/sangue , Abstinência de Álcool/psicologia , Consumo de Bebidas Alcoólicas/sangue , Alcoolismo/psicologia , Disfunção Cognitiva/psicologia , Reserva Cognitiva , Comorbidade , Feminino , Humanos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Componente Principal , Curva ROC
6.
Int J Mol Sci ; 22(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208173

RESUMO

Maternal malnutrition in critical periods of development increases the risk of developing short- and long-term diseases in the offspring. The alterations induced by this nutritional programming in the hypothalamus of the offspring are of special relevance due to its role in energy homeostasis, especially in the endocannabinoid system (ECS), which is involved in metabolic functions. Since astrocytes are essential for neuronal energy efficiency and are implicated in brain endocannabinoid signaling, here we have used a rat model to investigate whether a moderate caloric restriction (R) spanning from two weeks prior to the start of gestation to its end induced changes in offspring hypothalamic (a) ECS, (b) lipid metabolism (LM) and/or (c) hypothalamic astrocytes. Monitorization was performed by analyzing both the gene and protein expression of proteins involved in LM and ECS signaling. Offspring born from caloric-restricted mothers presented hypothalamic alterations in both the main enzymes involved in LM and endocannabinoids synthesis/degradation. Furthermore, most of these changes were similar to those observed in hypothalamic offspring astrocytes in culture. In conclusion, a maternal low caloric intake altered LM and ECS in both the hypothalamus and its astrocytes, pointing to these glial cells as responsible for a large part of the alterations seen in the total hypothalamus and suggesting a high degree of involvement of astrocytes in nutritional programming.


Assuntos
Astrócitos/metabolismo , Restrição Calórica , Endocanabinoides/metabolismo , Hipotálamo/metabolismo , Metabolismo dos Lipídeos , Transdução de Sinais , Animais , Animais Recém-Nascidos , Peso Corporal , Encéfalo/patologia , Feminino , Regulação da Expressão Gênica , Gliose/genética , Gliose/patologia , Inflamação/genética , Inflamação/patologia , Metabolismo dos Lipídeos/genética , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Transdução de Sinais/genética
7.
Brain Struct Funct ; 226(7): 2243-2264, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34236532

RESUMO

Preclinical studies on the effects of abrupt cessation of selective serotonin reuptake inhibitors (SSRIs), a medication often prescribed in alcohol use disorder (AUD) patients with depression, results in alcohol consumption escalation after resuming drinking. However, a potential neuroinflammatory component on this escalation remains unexplored despite the immunomodulatory role of serotonin. Here, we utilized a rat model of 14-daily administration of the SSRI fluoxetine (10 mg/kg/day) along alcohol self-administration deprivation to study the effects of fluoxetine cessation on neuroinflammation after resuming alcohol drinking. Microglial morphology and inflammatory gene expression were analyzed in prelimbic cortex, striatum, basolateral amygdala and dorsal hippocampus. Results indicated that alcohol drinking reinstatement increased microglial IBA1 immunoreactivity and altered morphometric features of activated microglia (fractal dimension, lacunarity, density, roughness, and cell area, perimeter and circularity). Despite alcohol reinstatement, fluoxetine cessation modified microglial morphology in a brain region-specific manner, resulting in hyper-ramified (spatial complexity of branching), reactive (lower heterogeneity and circularity)-like microglia. We also found that microglial cell area correlated with changes in mRNA expression of chemokines (Cx3cl1/fractalkine, Cxcl12/SDF1α, Ccl2/MCP1), cytokines (IL1ß, IL6, IL10) and the innate immune toll-like receptor 4 (TLR4) in dorsal hippocampus. Specifically, TLR4 correlated with microglial spatial complexity assessed by fractal dimension in striatum, suggesting a role in process branching. These findings suggest that alcohol drinking reinstatement after fluoxetine treatment cessation disturbs microglial morphology and reactive phenotype associated with a TLR4/inflammatory response to alcohol in a brain region-specific manner, facts that might contribute to alcohol-induced damage through the promotion of escalation of alcohol drinking behavior.


Assuntos
Microglia , Consumo de Bebidas Alcoólicas , Animais , Encéfalo/metabolismo , Etanol , Fluoxetina , Humanos , Microglia/metabolismo , Doenças Neuroinflamatórias , Ratos , Inibidores Seletivos de Recaptação de Serotonina , Receptor 4 Toll-Like/metabolismo
8.
Sensors (Basel) ; 21(4)2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33672194

RESUMO

Condition monitoring devices in hydraulic systems that use batteries or require wired infrastructure have drawbacks that affect their installation, maintenance costs, and deployment flexibility. Energy harvesting technologies can serve as an alternative power supply for system loads, eliminating batteries and wiring requirements. Despite the interest in pressure fluctuation energy harvesters, few studies consider end-to-end implementations, especially for cases with low-amplitude pressure fluctuations. This generates a research gap regarding the practical amount of energy available to the load under these conditions, as well as interface circuit requirements and techniques for efficient energy conversion. In this paper, we present a self-powered sensor that integrates an energy harvester and a wireless sensing system. The energy harvester converts pressure fluctuations in hydraulic systems into electrical energy using an acoustic resonator, a piezoelectric stack, and an interface circuit. The prototype wireless sensor consists of an industrial pressure sensor and a low-power Bluetooth System-on-chip that samples and wirelessly transmits pressure data. We present a subsystem analysis and a full system implementation that considers hydraulic systems with pressure fluctuation amplitudes of less than 1 bar and frequencies of less than 300 Hz. The study examines the frequency response of the energy harvester, the performance of the interface circuit, and the advantages of using an active power improvement unit adapted for piezoelectric stacks. We show that the interface circuit used improves the performance of the energy harvester compared to previous similar studies, showing more power generation compared to the standard interface. Experimental measurements show that the self-powered sensor system can start up by harvesting energy from pressure fluctuations with amplitudes starting at 0.2 bar at 200 Hz. It can also sample and transmit sensor data at a rate of 100 Hz at 0.7 bar at 200 Hz. The system is implemented with off-the-shelf circuits.

9.
J Comp Neurol ; 529(8): 1724-1742, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33047300

RESUMO

Adult neurogenesis in rodents is modulated by dopaminergic signaling and inhibited by cocaine. However, the sex-specific role of dopamine D1 and D2 receptors (D1R, D2R) in the deleterious effect of cocaine on adult neurogenesis has not been described yet. Here, we explored sex differences in (a) cell proliferation (5'-bromo-2'-deoxyuridine [BrdU]), (b) neural precursor (nestin), (c) neuronal phenotype (BrdU/ß3-tubulin), and (d) neuronal maturity (NeuN) in the subventricular zone (SVZ) of the lateral ventricles and striatum of mice with genetic deletion (D1-/- , D2-/- ) or pharmacological blockage (SCH23390: 0.1 mg/kg/day/5 days; Raclopride: 0.3 mg/kg/day/5 days) of D1R and D2R, and treated (10 mg/kg/day/5 days) and then challenged (5 mg/kg, 48 hr later) with cocaine. Results indicated that hyperactivity responses to cocaine were absent in D1-/- mice and reduced in SCH23390-treated mice. Activity responses to cocaine were reduced in D2-/- males, but absent in D2-/- females and increased in Raclopride-treated females. D1R deletion blocked the deleterious effect of cocaine on SVZ cell proliferation in males. Cocaine-exposed D1-/- males also had reduced neuronal phenotype of SVZ newborn cells and increased striatal neuronal maturity. D2-/- mice had lower proliferative and neural precursor responses. Cocaine in D2-/- females or coadministered with Raclopride in wild-type females improved SVZ cell proliferation, an effect that positively correlated with plasma brain-derived neurotrophic factor (BDNF) concentrations. In conclusion, the sex-specific D1R and D2R signaling on SVZ cell proliferation, neural progenitor and neuronal maturity is differentially perturbed by cocaine, and BDNF may be required to link D2R to neuroplasticity in cocaine addiction in females.


Assuntos
Cocaína/farmacologia , Inibidores da Captação de Dopamina/farmacologia , Neurogênese/efeitos dos fármacos , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismo , Animais , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Feminino , Ventrículos Laterais/efeitos dos fármacos , Ventrículos Laterais/metabolismo , Masculino , Camundongos , Camundongos Knockout , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Caracteres Sexuais
10.
Virulence ; 11(1): 315-326, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32255384

RESUMO

Acinetobacter baumannii is a nosocomial pathogen that causes multi-drug resistant infections mainly in immunocompromised patients. Although this gram-negative species lacks flagella, it is able to move over wet surfaces through a not well characterized type of movement known as surface-associated motility. In this study we demonstrate through the inactivation of the A1S_2813 gene (coding a CheW-like protein) and recA (coding a DNA damage repair and recombination protein) that both genes are involved in the surface-associated motility and chemotaxis of A. baumannii ATCC 17978 strain. In addition, we also point out that the lack of either RecA or CheW-like proteins reduces its virulence in the Caenorhabditis elegans and the Galleria mellonella animal models. Furthermore, we show through co-immunoprecipitation assays that the CheW-like protein and RecA interact and that this interaction is abolished by the introduction of the mutation S97A in one of the domains of CheW-like protein that is structurally conserved in Salmonella enterica and necessary for the RecA-CheW interaction in this bacterial species. Finally, we show that the replacement of the wild-type CheW-like protein by that presenting the S97A mutation impairs surface-associated motility, chemotaxis and virulence of A. baumannii strain ATCC 17978.


Assuntos
Acinetobacter baumannii/patogenicidade , Proteínas de Bactérias/metabolismo , Quimiotaxia , Proteínas de Ligação a DNA/metabolismo , Recombinases Rec A/metabolismo , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/genética , Acinetobacter baumannii/metabolismo , Animais , Proteínas de Bactérias/genética , Caenorhabditis elegans/microbiologia , Proteínas de Ligação a DNA/genética , Mariposas/microbiologia , Recombinases Rec A/genética , Virulência/genética
11.
mSphere ; 5(2)2020 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-32132161

RESUMO

Ralstonia solanacearum is a bacterial plant pathogen causing important economic losses worldwide. In addition to the polar flagella responsible for swimming motility, this pathogen produces type IV pili (TFP) that govern twitching motility, a flagellum-independent movement on solid surfaces. The implication of chemotaxis in plant colonization, through the control flagellar rotation by the proteins CheW and CheA, has been previously reported in R. solanacearum In this work, we have identified in this bacterium homologues of the Pseudomonas aeruginosapilI and chpA genes, suggested to play roles in TFP-associated motility analogous to those played by the cheW and cheA genes, respectively. We demonstrate that R. solanacearum strains with a deletion of the pilI or the chpA coding region show normal swimming and chemotaxis but altered biofilm formation and reduced twitching motility, transformation efficiency, and root attachment. Furthermore, these mutants displayed wild-type growth in planta and impaired virulence on tomato plants after soil-drench inoculations but not when directly applied to the xylem. Comparison with deletion mutants for pilA and fliC-encoding the major pilin and flagellin subunits, respectively-showed that both twitching and swimming are required for plant colonization and full virulence. This work proves for the first time the functionality of a pilus-mediated pathway encoded by pil-chp genes in R. solanacearum, demonstrating that pilI and chpA genes are bona fide motility regulators controlling twitching motility and its three related phenotypes: virulence, natural transformation, and biofilm formation.IMPORTANCE Twitching and swimming are two bacterial movements governed by pili and flagella. The present work identifies for the first time in the Gram-negative plant pathogen Ralstonia solanacearum a pilus-mediated chemotaxis pathway analogous to that governing flagellum-mediated chemotaxis. We show that regulatory genes in this pathway control all of the phenotypes related to pili, including twitching motility, natural transformation, and biofilm formation, and are also directly implicated in virulence, mainly during the first steps of the plant infection. Our results show that pili have a higher impact than flagella on the interaction of R. solanacearum with tomato plants and reveal new types of cross-talk between the swimming and twitching motility phenotypes: enhanced swimming in bacteria lacking pili and a role for the flagellum in root attachment.


Assuntos
Proteínas de Bactérias/genética , Fímbrias Bacterianas/genética , Ralstonia solanacearum/genética , Ralstonia solanacearum/patogenicidade , Biofilmes , Quimiotaxia/genética , Fímbrias Bacterianas/fisiologia , Regulação Bacteriana da Expressão Gênica , Solanum lycopersicum/microbiologia , Movimento , Doenças das Plantas/microbiologia , Pseudomonas aeruginosa/genética , Ralstonia solanacearum/fisiologia
12.
Artigo em Inglês | MEDLINE | ID: mdl-30642939

RESUMO

Although the relationship between Acinetobacter baumannii efflux pumps and antimicrobial resistance is well documented, less is known about the involvement of these proteins in the pathogenicity of this nosocomial pathogen. In previous work, we identified the AbaQ major facilitator superfamily (MFS) efflux pump and demonstrated its participation in the motility and virulence of A. baumannii In the present study, we examined the role in these processes of A. baumannii transporters belonging to different superfamilies of efflux pumps. Genes encoding known or putative permeases belonging to efflux pump superfamilies other than the MFS were selected, and the corresponding knockouts were constructed. The antimicrobial susceptibilities of these mutants were consistent with previously reported data. In mutants of A. baumannii strain ATCC 17978 carrying inactivated genes encoding the efflux pumps A1S_2736 (resistance nodulation division [RND]), A1S_3371 (multidrug and toxic compound extrusion [MATE]), and A1S_0710 (small multidrug resistance [SMR]), as well as the newly described ATP-binding cassette (ABC) permeases A1S_1242 and A1S_2622, both surface-associated motility and virulence were reduced compared to the parental strain. However, inactivation of the genes encoding the known ABC permeases A1S_0536 and A1S_1535, the newly identified putative ABC permeases A1S_0027 and A1S_1057, or the proteobacterial antimicrobial compound efflux (PACE) transporters A1S_1503 and A1S_2063 had no effects on bacterial motility or virulence. Our results demonstrate the involvement of antimicrobial transporters belonging at least to five of the six known efflux pump superfamilies in both surface-associated motility and virulence in A. baumannii ATCC 17978.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/patogenicidade , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Proteínas de Membrana Transportadoras/metabolismo , Acinetobacter baumannii/genética , Animais , Transporte Biológico/genética , Infecção Hospitalar/microbiologia , Regulação Bacteriana da Expressão Gênica , Humanos , Proteínas de Membrana Transportadoras/genética , Testes de Sensibilidade Microbiana , Mariposas/microbiologia
13.
Front Microbiol ; 10: 3075, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32010115

RESUMO

Multidrug-Resistant (MDR) and Extensively Drug Resistant (XDR) Acinetobacter baumannii (Ab) represent a serious cause of healthcare-associated infections worldwide. Currently, the available treatment options are very restricted and colistin-based therapies are last-line treatments of these infections, even though colistin resistant (COLR) Ab have rarely been isolated yet. In bacteria, small non-coding RNAs (sRNAs) have been implicated in regulatory pathways of different biological functions, however, no knowledge exists about the sRNA role on the biological adaptation in COLR Ab. Our study investigated two Italian XDR isogenic colistin-susceptible/resistant (COLS/R) Ab strain-pairs to discover new sRNA signatures. Comparative sRNA transcriptome (sRNAome) analyses were carried out by Illumina RNA-seq using both a Tru-Seq and a Short Insert library, whilst Ab ATCC 17978 and ACICU Reference Genome assembly, mapping, annotation and statistically significant differential expression (q-value ≤ 0.01) of the raw reads were performed by the Rockhopper tool. A computational filtering, sorting only similarly statistically significant differentially expressed (DE) sRNAs mapping on the same gene in both COLR Ab isolates was conducted. COLR vs. COLS sRNAome, analyzed integrating the DE sRNAs obtained from the two different libraries, revealed some statistically significant DE sRNAs in COLR Ab. In detail, we found: (i) two different under-expressed cis-acting sRNAs (AbsRNA1 and AbsRNA2) mapping in antisense orientation the 16S rRNA gene A1S_r01, (ii) one under-expressed cis-acting sRNA (AbsRNA3) targeting the A1S_2505 gene (hypothetical protein), (iii) one under-expressed microRNA-size small RNA fragment (AbsRNA4) and its pre-microAbsRNA4 targeting the A1S_0501 gene (hypothetical protein), (iv) as well as an over-expressed microRNA-size small RNA fragment (AbsRNA5) and its pre-microAbsRNA5 targeting the A1S_3097 gene (signal peptide). Custom TaqMan® probe-based real-time qPCRs validated the expression pattern of the selected sRNA candidates shown by RNA-seq. Furthermore, analysis on sRNA ΔA1S_r01, ΔA1S_2505 as well as the over-expressed A1S_3097 mutants revealed no effects on colistin resistance. Our study, for the first time, found the sRNAome signatures of clinical COLR Ab with a computational prediction of their targets related to protein synthesis, host-microbe interaction and other different biological functions, including biofilm production, cell-cycle control, virulence, and antibiotic-resistance.

14.
Artigo em Inglês | MEDLINE | ID: mdl-29941648

RESUMO

Acinetobacter baumannii has emerged as an important multidrug-resistant nosocomial pathogen. In previous work, we identified a putative MFS transporter, AU097_RS17040, involved in the pathogenicity of A. baumannii (M. Pérez-Varela, J. Corral, J. A. Vallejo, S. Rumbo-Feal, G. Bou, J. Aranda, and J. Barbé, Infect Immun 85:e00327-17, 2017, https://doi.org/10.1128/IAI.00327-17). In this study, we analyzed the susceptibility to diverse antimicrobial agents of A. baumannii cells defective in this transporter, referred to as AbaQ. Our results showed that AbaQ is mainly involved in the extrusion of quinolone-type drugs in A. baumannii.


Assuntos
Infecções por Acinetobacter/tratamento farmacológico , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana Múltipla/fisiologia , Quinolonas/farmacologia , Infecções por Acinetobacter/metabolismo , Humanos , Proteínas de Membrana Transportadoras/metabolismo , Testes de Sensibilidade Microbiana/métodos
15.
Artigo em Inglês | MEDLINE | ID: mdl-29712662

RESUMO

Colistin is a crucial last-line drug used for the treatment of life-threatening infections caused by multidrug-resistant strains of the Gram-negative bacterium Acinetobacter baumannii However, colistin-resistant A. baumannii isolates can still be isolated following failed colistin therapy. Resistance is most often mediated by the addition of phosphoethanolamine (pEtN) to lipid A by PmrC, following missense mutations in the pmrCAB operon encoding PmrC and the two-component signal transduction system PmrA/PmrB. We recovered a pair of A. baumannii isolates from a single patient before (6009-1) and after (6009-2) failed colistin treatment. These strains displayed low and very high levels of colistin resistance (MICs, 8 to 16 µg/ml and 128 µg/ml), respectively. To understand how increased colistin resistance arose, we sequenced the genome of each isolate, which revealed that 6009-2 had an extra copy of the insertion sequence element ISAba125 within a gene encoding an H-NS family transcriptional regulator. To confirm the role of H-NS in colistin resistance, we generated an hns deletion mutant in 6009-1 and showed that colistin resistance increased upon the deletion of hns We also provided 6009-2 with an intact copy of hns and showed that the strain was no longer resistant to high concentrations of colistin. Transcriptomic analysis of the clinical isolates identified more than 150 genes as being differentially expressed in the colistin-resistant hns mutant 6009-2. Importantly, the expression of eptA, encoding a second lipid A-specific pEtN transferase but not pmrC, was increased in the hns mutant. This is the first time an H-NS family transcriptional regulator has been associated with a pEtN transferase and colistin resistance.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/metabolismo , Antibacterianos/farmacologia , Colistina/farmacologia , Acinetobacter baumannii/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana/genética , Etanolaminofosfotransferase/genética , Etanolaminofosfotransferase/metabolismo , Perfilação da Expressão Gênica , Testes de Sensibilidade Microbiana , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Infect Immun ; 85(8)2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28507065

RESUMO

Acinetobacter baumannii is a major cause of antibiotic-resistant nosocomial infections worldwide. In this study, several rifampin-resistant spontaneous mutants obtained from the A. baumannii ATCC 17978 strain that differed in their point mutations in the rpoB gene, encoding the ß-subunit of the RNA polymerase, were isolated. All the mutants harboring amino acid substitutions in position 522 or 540 of the RpoB protein were impaired in surface-associated motility and had attenuated virulence in the fertility model of Caenorhabditis elegans The transcriptional profile of these mutants included six downregulated genes encoding proteins homologous to transporters and metabolic enzymes widespread among A. baumannii clinical isolates. The construction of knockout mutants in each of the six downregulated genes revealed a significant reduction in the surface-associated motility and virulence of four of them in the A. baumannii ATCC 17978 strain, as well as in the virulent clinical isolate MAR002. Taken together, our results provide strong evidence of the connection between motility and virulence in this multiresistant nosocomial pathogen.


Assuntos
Acinetobacter baumannii/genética , Acinetobacter baumannii/patogenicidade , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Mutação Puntual , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/enzimologia , Acinetobacter baumannii/fisiologia , Substituição de Aminoácidos , Animais , Proteínas de Bactérias/genética , Caenorhabditis elegans/microbiologia , Infecção Hospitalar/microbiologia , RNA Polimerases Dirigidas por DNA/química , Regulação para Baixo , Farmacorresistência Bacteriana Múltipla , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Humanos , Proteínas de Membrana Transportadoras/genética , Virulência/genética
17.
Front Microbiol ; 7: 1560, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27766091

RESUMO

In addition to its role in DNA damage repair and recombination, the RecA protein, through its interaction with CheW, is involved in swarming motility, a form of flagella-dependent movement across surfaces. In order to better understand how SOS response modulates swarming, in this work the location of RecA and CheW proteins within the swarming cells has been studied by using super-resolution microscopy. Further, and after in silico docking studies, the specific RecA and CheW regions associated with the RecA-CheW interaction have also been confirmed by site-directed mutagenesis and immunoprecipitation techniques. Our results point out that the CheW distribution changes, from the cell poles to foci distributed in a helical pattern along the cell axis when SOS response is activated or RecA protein is overexpressed. In this situation, the CheW presents the same subcellular location as that of RecA, pointing out that the previously described RecA storage structures may be modulators of swarming motility. Data reported herein not only confirmed that the RecA-CheW pair is essential for swarming motility but it is directly involved in the CheW distribution change associated to SOS response activation. A model explaining not only the mechanism by which DNA damage modulates swarming but also how both the lack and the excess of RecA protein impair this motility is proposed.

18.
Antimicrob Agents Chemother ; 60(1): 637-9, 2016 01.
Artigo em Inglês | MEDLINE | ID: mdl-26503651

RESUMO

Acinetobacter baumannii, a worldwide emerging nosocomial pathogen, acquires antimicrobial resistances in response to DNA-damaging agents, which increase the expression of multiple error-prone DNA polymerase components. Here we show that the aminocoumarin novobiocin, which inhibits the DNA damage response in Gram-positive bacteria, also inhibits the expression of error-prone DNA polymerases in this Gram-negative multidrug-resistant pathogen and, consequently, its potential acquisition of antimicrobial resistance through DNA damage-induced mutagenesis.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Reparo do DNA/efeitos dos fármacos , DNA Polimerase Dirigida por DNA/genética , Farmacorresistência Bacteriana/genética , Novobiocina/farmacologia , Acinetobacter baumannii/genética , Acinetobacter baumannii/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Dano ao DNA , DNA Bacteriano/genética , DNA Polimerase Dirigida por DNA/metabolismo , Regulação Bacteriana da Expressão Gênica , Testes de Sensibilidade Microbiana , Mutagênese
19.
Salud Publica Mex ; 57(4): 304-11, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26395795

RESUMO

OBJECTIVE: In 2009, 4 749 rapid HIV tests were run in Morelos, Mexico, despite lacking evidence on their results. This article seeks to analyze how public health organization relates to utility of rapid HIV test among healthcare users. MATERIALS AND METHODS: Joint study: comparison of differences in applied test and positive results for each group with the Bonferroni statistical tool, observational study in 34 health subsystems, and 11 interviews with public healthcare users. RESULTS: Each subsystem processes influenced the use and usefulness of screening; for instance, primary care centers test only pregnant women and exclude men who have sex with men (MSM). That group shows significant differences (p<0.007) in the HIV-positive test with respect to other groups. CONCLUSIONS: Despite the availability of rapid detection tests and epidemiological evidence, the way public health services are organized impedes an efficient diagnosis in the group with higher risk, namely MSM. The distribution of rapid HIV tests was guided by stigmatization.


Assuntos
Sorodiagnóstico da AIDS/métodos , Infecções por HIV/diagnóstico , Acessibilidade aos Serviços de Saúde , Disparidades em Assistência à Saúde , Programas de Rastreamento/métodos , Atenção Primária à Saúde/estatística & dados numéricos , Prática de Saúde Pública/estatística & dados numéricos , Populações Vulneráveis , Sorodiagnóstico da AIDS/estatística & dados numéricos , Diagnóstico Precoce , Feminino , Infecções por HIV/epidemiologia , Soropositividade para HIV , Humanos , Masculino , México/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/epidemiologia , Preconceito , Prisioneiros , Comportamento Sexual , Estigma Social , Fatores de Tempo
20.
Salud pública Méx ; 57(4): 304-311, jul.-ago. 2015. ilus, tab
Artigo em Inglês | LILACS | ID: lil-760507

RESUMO

Objective. In 2009, 4 749 rapid HIV tests were run in Morelos, Mexico, despite lacking evidence on their results. This article seeks to analyze how public health organization relates to utility of rapid HIV test among healthcare users. Materials and methods. Joint study: comparison of differences in applied test and positive results for each group with the Bonferroni statistical tool, observational study in 34 health subsystems, and 11 interviews with public healthcare users. Results. Each subsystem processes influenced the use and usefulness of screening; for instance, primary care centers test only pregnant women and exclude men who have sex with men (MSM). That group shows significant differences (p<0.007) in the HIV-positive test with respect to other groups. Conclusions. Despite the availability of rapid detection tests and epidemiological evidence, the way public health services are organized impedes an efficient diagnosis in the group with higher risk, namely MSM. The distribution of rapid HIV tests was guided by stigmatization.


Objetivo. En 2009, 4 749 pruebas rápidas de detección de VIH fueron aplicadas en Morelos, México, sin evidencias de resultados. Se hace necesario analizar la distribución de estas pruebas y las consecuencias que la organización de los servicios de salud tuvo para el diagnóstico del VIH en las poblaciones clave. Material y métodos. Estudio mixto: comparación de diferencias en pruebas aplicadas y casos diagnosticados en grupos mediante la técnica de Bonferroni, observaciones en 34 subsistemas de salud y 11 entrevistas a usuarios. Resultados. Los procesos de cada subsistema incidieron en la utilización y utilidad del tamizaje: se focalizó en mujeres embarazadas y se excluyó a grupos en mayor riesgo (p<0.007) en hombres que tienen sexo con otros hombres (HSH). Conclusiones. A pesar de la disponibilidad de las pruebas y de información epidemiológica, la organización de los servicios impidió una mayor captación de HSH. La estigmatización influyó en las formas de distribuirlas.


Assuntos
Humanos , Masculino , Feminino , Gravidez , Atenção Primária à Saúde/estatística & dados numéricos , Sorodiagnóstico da AIDS/métodos , Infecções por HIV/diagnóstico , Prática de Saúde Pública/estatística & dados numéricos , Programas de Rastreamento/métodos , Populações Vulneráveis , Disparidades em Assistência à Saúde , Acessibilidade aos Serviços de Saúde , Complicações Infecciosas na Gravidez/diagnóstico , Preconceito , Prisioneiros , Comportamento Sexual , Fatores de Tempo , Sorodiagnóstico da AIDS/estatística & dados numéricos , Infecções por HIV/epidemiologia , Soropositividade para HIV , Diagnóstico Precoce , Estigma Social , México/epidemiologia
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