Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 76
Filtrar
1.
Pharmaceuticals (Basel) ; 17(3)2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38543106

RESUMEN

This study aimed to co-encapsulate ceftazidime and tobramycin in zein nanoparticles coated with chitosan and to characterize and evaluate the antibacterial and antibiofilm activity against antibiotic-resistant Pseudomonas aeruginosa and Klebsiella pneumoniae. Zein nanoparticles, synthesized using the nanoprecipitation method, were characterized by their particle size (Ø), polydispersity index (PDI), zeta potential (ζ), pH, and encapsulation efficiency (%EE). The chitosan coating provided stability, and physicochemical analyses revealed chemical interactions, efficient drug encapsulation, and thermal stability. The release kinetics demonstrated controlled release in simulated gastric and intestinal pH. The antibacterial activity, assessed by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), indicated effectiveness against both pathogens. Antibiofilm assays, conducted using the crystal violet method, demonstrated the inhibition and eradication of biofilms. The chitosan-coated zein nanoparticles with CAZ and/or TOB exhibited Ø (315-335 nm), PDI (<0.2), ζ (+40 to +50 mV), pH (5), and %EE (>55%). Notably, the co-encapsulation formulation (CAZ-TOB-ZNP-CH) showed enhanced antibacterial and antibiofilm activities compared to the individual formulations. These findings suggest that the developed nanoparticles present a promising alternative for treating respiratory and intestinal infections caused by antibiotic-resistant and biofilm-producing P. aeruginosa and K. pneumoniae.

2.
J Appl Microbiol ; 135(4)2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38520165

RESUMEN

AIMS: Investigated and compared the occurrence of virulence genes fimH, mrkD, irp2, entB, cps, rmpA, and wabG, resistance genes blaKPC and blaNDM, and the genetic variability and clonal relationship of 29 Klebsiella pneumoniae clinical isolates of patients with and without COVID-19, from a hospital in Brazil. METHODS AND RESULTS: All isolates were resistant to beta-lactams. The genes were investigated by PCR, and for molecular typing, enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and MLST were used. The detection of blaNDM was greater (n = 23) when compared to that of blaKPC (n = 14). The virulence genes that most occurred were fimH, entB, cps, and wabG, which are responsible for adhesins, siderophore enterobactin, capsule, and lipopolysaccharides, respectively. Among the isolates, 21 distinct genetic profiles were found by ERIC-PCR, with multiclonal dissemination. Four isolates belonged to the ST11 clone. CONCLUSIONS: The occurrence of the ST11 is worrying as it is a high-risk clone involved in the dissemination of virulent strains throughout the world.


Asunto(s)
COVID-19 , Infecciones por Klebsiella , Klebsiella pneumoniae , SARS-CoV-2 , beta-Lactamasas , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Klebsiella pneumoniae/patogenicidad , Brasil , Humanos , Infecciones por Klebsiella/microbiología , COVID-19/microbiología , beta-Lactamasas/genética , SARS-CoV-2/genética , Virulencia/genética , Antibacterianos/farmacología , Tipificación de Secuencias Multilocus , Pruebas de Sensibilidad Microbiana , Factores de Virulencia/genética
3.
Appl Microbiol Biotechnol ; 108(1): 241, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38413482

RESUMEN

The present work aimed to develop, characterize, and evaluate the antibacterial and antibiofilm activity of two nanoemulsions (NEs) containing 500 µg/mL of curcumin from Curcuma longa (CUR). These NEs, produced with heating, contain olive oil (5%) and the surfactants tween 80 (5%) and span 80 (2.5%), water q.s. 100 mL, and were stable for 120 days. NE-2-CUR presented Ø of 165.40 ± 2.56 nm, PDI of 0.254, ζ of - 33.20 ± 1.35 mV, pH of 6.49, and Entrapment Drug Efficiency (EE) of 99%. The NE-4-CUR showed a Ø of 105.70 ± 4.13 nm, PDI of 0.459, ζ of - 32.10 ± 1.45 mV, pH of 6.40 and EE of 99.29%. Structural characterization was performed using DRX and FTIR, thermal characterization using DSC and TG, and morphological characterization using SEM, suggesting that there is no significant change in the CUR present in the NEs and that they remain stable. The MIC was performed by the broth microdilution method for nine gram-positive and gram-negative bacteria, as well as Klebsiella pneumoniae clinical isolates resistant to antibiotics and biofilm and efflux pump producers. The NEs mostly showed a bacteriostatic profile. The MIC varied between 125 and 250 µg/mL. The most sensitive bacteria were Staphylococcus aureus and Enterococcus faecalis, for which NE-2-CUR showed a MIC of 125 µg/mL. The NEs and ceftazidime (CAZ) interaction was also evaluated against the K. pneumoniae resistant clinical isolates using the Checkerboard method. NE-2-CUR and NE-4-CUR showed a synergistic or additive profile; there was a reduction in CAZ MICs between 256 times (K26-A2) and 2 times (K29-A2). Furthermore, the NEs inhibited these isolates biofilms formation. The NEs showed a MBIC ranging from 15.625 to 250 µg/mL. Thus, the NEs showed physicochemical characteristics suitable for future clinical trials, enhancing the CAZ antibacterial and antibiofilm activity, thus becoming a promising strategy for the treatment of bacterial infections caused by multidrug-resistant K. pneumoniae. KEY POINTS: • The NEs showed physicochemical characteristics suitable for future clinical trials. • The NEs showed a synergistic/additive profile, when associated with ceftazidime. • The NEs inhibited biofilm formation of clinical isolates.


Asunto(s)
Antiinfecciosos , Curcumina , Antibacterianos/farmacología , Ceftazidima/farmacología , Curcumina/farmacología , Curcumina/química , Aceite de Oliva/farmacología , Bacterias Grampositivas , Bacterias Gramnegativas , Antiinfecciosos/farmacología , Klebsiella pneumoniae , Pruebas de Sensibilidad Microbiana
4.
J Appl Microbiol ; 134(11)2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37880999

RESUMEN

AIMS: Determine which sequence type (ST) clones were carrying the blaKPC, blaNDM, blaVIM, blaIMP, and blaGES genes and their variants in clinical isolates of multidrug-resistant Klebsiella pneumoniae. METHODS AND RESULTS: Ten K. pneumoniae isolates were obtained from the colonized and infected patients in a public hospital in the city of Recife-PE, in northeastern Brazil, and were further analyzed. The detection of carbapenem resistance genes and the seven housekeeping genes [for multilocus sequence typing (MLST) detection] were done with PCR and sequencing. The blaKPC and blaNDM genes were detected concomitantly in all isolates, with variants being detected blaNDM-1, blaNDM-5, blaNDM-7, and blaKPC-2. The blaKPC-2 and blaNDM-1 combination being the most frequent. Molecular typing by MLST detected three types of high-risk ST clones, associated with the clonal complex 258, ST11/CC258 in eight isolates, and ST855/CC258 and ST340/CC258 in the other two isolates. CONCLUSIONS: These findings are worrying, as they have a negative impact on the scenario of antimicrobial resistance, and show the high genetic variability of K. pneumoniae and its ability to mutate resistance genes and risk of dissemination via different ST clones.


Asunto(s)
Klebsiella pneumoniae , beta-Lactamasas , Humanos , Klebsiella pneumoniae/genética , Tipificación de Secuencias Multilocus , beta-Lactamasas/genética , Brasil/epidemiología , Células Clonales , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología
5.
J Ethnopharmacol ; 317: 116858, 2023 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-37400005

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Amburana cearensis (Allemão) A.C. Smith is a medicinal plant with wide distribution in South America, popularly known in Brazil as "cumaru" or "amburana de cheiro". In folk medicine, in the semi-arid region of Northeastern Brazil, infusions, teas and decoctions of leaves of Amburana cearensis have their practical use for treating fever, gastrointestinal disorders, inflammation, and inflammation pain. However, none of the ethnopharmacological properties has been scientifically evaluated using volatile compounds obtained from its leaves (essential oil). AIM OF THE STUDY: This study investigated the chemical composition, acute oral toxicity, and antinociceptive and anti-inflammatory activities of the essential oil from the leaves of A. cearensis. MATERIAL AND METHODS: The acute toxicity of the essential oil was investigated in mice. The antinociceptive effect was evaluated using the formalin test and, abdominal writhing induced by acetic acid, being investigated the possible mechanisms of action involved in antinociception. The acute anti-inflammatory effect was investigated through models of carrageenan-induced peritonitis, yeast-induced pyrexia, and carrageenan- and histamine-induced paw inflammation. RESULTS: No acute toxicity was observed at doses up to 2000 mg/kg; p.o. The antinociceptive effect was statistically equal to morphine. In the formalin assay, the oil showed analgesic activity in the neurogenic and inflammatory phases, having as mechanisms the cholinergic, adenosinergic system, and ATP-sensitive potassium channels (K-ATP). In peritonitis, a reduction in TNF-α and IL-1ß levels and leukocyte migration were observed. The antipyretic effect was statistically superior to dipyrone. The reduction in paw edema was statistically superior to the standard in both models. CONCLUSION: The results obtained not only support the traditional use of the species in inflammatory conditions and pain in folk medicine but also demonstrate that this is a rich source of phytocomponents such as germacrone, which can be used as a natural and sustainable therapeutic agent with industrial applications.


Asunto(s)
Fabaceae , Aceites Volátiles , Peritonitis , Ratones , Animales , Aceites Volátiles/uso terapéutico , Aceites Volátiles/toxicidad , Carragenina , Brasil , Antiinflamatorios/uso terapéutico , Antiinflamatorios/toxicidad , Analgésicos/uso terapéutico , Analgésicos/toxicidad , Dolor/tratamiento farmacológico , Dolor/inducido químicamente , Extractos Vegetales/uso terapéutico , Extractos Vegetales/toxicidad , Inflamación/tratamiento farmacológico , Peritonitis/tratamiento farmacológico , Hojas de la Planta/química , Edema/inducido químicamente , Edema/tratamiento farmacológico
6.
Viruses ; 15(2)2023 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-36851565

RESUMEN

The COVID-19 pandemic has engendered significant scientific efforts in the understanding of its infectious agent SARS-CoV-2 and of its associated symptoms. A peculiar characteristic of this virus lies in its ability to challenge our senses, as its infection can lead to anosmia and ageusia. While ocular symptoms, such as conjunctivitis, optic neuritis or dry eyes, are also reported after viral infection, they have lower frequencies and severities, and their functional development is still elusive. Here, using combined technical approaches based on histological and gene profiling methods, we characterized the expression of SARS-CoV-2 binding sites (Ace2/Tmprss2) in the mouse eye. We found that ACE2 was ectopically expressed in subtissular ocular regions, such as in the optic nerve and in the Harderian/intraorbital lacrimal glands. Moreover, we observed an important variation of Ace2/Tmprss2 expression that is not only dependent on the age and sex of the animal, but also highly heterogenous between individuals. Our results thus give new insight into the expression of SARS-CoV-2 binding sites in the mouse eye and propose an interpretation of the human ocular-associated symptoms linked to SARS-CoV-2.


Asunto(s)
COVID-19 , Aparato Lagrimal , Humanos , Animales , Ratones , SARS-CoV-2 , Enzima Convertidora de Angiotensina 2/genética , Pandemias , Sitios de Unión
7.
Front Nutr ; 9: 1026373, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36438763

RESUMEN

Food preference is conserved from the most primitive organisms to social animals including humans. A continuous integration of olfactory cues present both in food and in the different environmental and physiological contexts favors the intake of a given source of food or its avoidance. Remarkably, in mice, food preference can also be acquired by olfactory communication in-between conspecifics, a behavior known as the social transmission of food preference (STFP). STFP occurs when a mouse sniffs the breath of a conspecific who has previously eaten a novel food emitting specific odorants and will then develop a preference for this never encountered food. The efficient discrimination of odorants is performed by olfactory sensory neurons (OSNs). It is essential and supports many of the decision-making processes. Here, we found that the olfactory marker protein (OMP), an enigmatic protein ubiquitously expressed in all mature olfactory neurons, is involved in the fine regulation of OSNs basal activity that directly impacts the odorant discrimination ability. Using a previously described Omp null mouse model, we noticed that although odorants and their hedonic-associated values were still perceived by these mice, compensatory behaviors such as a higher number of sniffing events were displayed both in the discrimination of complex odorant signatures and in social-related contexts. As a consequence, we found that the ability to differentiate the olfactory messages carried by individuals such as those implicated in the social transmission of food preference were significantly compromised in Omp null mice. Thus, our results not only give new insights into the role of OMP in the fine discrimination of odorants but also reinforce the fundamental implication of a functional olfactory system for food decision-making.

8.
Int J Biol Macromol ; 219: 374-383, 2022 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-35914555

RESUMEN

Soft materials are attracting much attention for the development of biostructures able to mimic the movement of natural systems by remote actuation. Multi-sensitive hydrogels are among the best materials for obtaining dynamic and biocompatible soft structures for soft actuators and related biomedical devices. Nevertheless, bioinks based on naturally occurring and stimuli responsive hydrogels able to be 3D printed continues being a challenge for advanced applications. In this work 3D printable electrically and magnetically responsive, non-cytotoxic, hybrid hydrogels based on alginate and zero monovalent iron nanoparticles (NPs) are presented. The effect of NPs addition on the physico-chemical properties of the hydrogels is addressed, together with its effect on the functional electroactive and magnetoactive response. NPs concentration up to 10 % do not affect the mechanical stability of the gels, while promoting an increase actuation response.


Asunto(s)
Hidrogeles , Nanopartículas , Alginatos/química , Hidrogeles/química , Hierro
9.
Arch Microbiol ; 204(8): 459, 2022 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-35788427

RESUMEN

To characterize phenotypically and genotypically an isolate of multidrug-resistant (MDR) K. pneumoniae from a patient with septicemia in a hospital in Recife-PE, Brazil, resistance and virulence genes were investigated using PCR and sequencing the amplicons, and the plasmid DNA was also sequenced. The K74-A3 isolate was resistant to all ß-lactams, including carbapenems, as well as to aminoglycosides and quinolones. By conducting a PCR analysis and sequencing, the variants blaNDM-7 associated with blaKPC-2 and the cps, wabG, fim-H, mrkD and entB virulence genes were identified. The analysis of plasmid revealed the presence of blaCTX-M15, aac(3)-IVa, aph(3')-Ia, aph(4)-Ia, aac(6')ib-cr, mph(A) and catB3, and also the plasmids IncX3, IncFIB, IncQ1, ColRNAI and ColpVC. To our knowledge, this is the first report of the blaNDM-7 gene in Recife-PE and we suggest that this variant is located in IncX3. These results alert us to the risk of spreading an isolate with a vast genetic arsenal of resistance, in addition to which several plasmids are present that favor the horizontal transfer of these genes.


Asunto(s)
Infecciones por Klebsiella , Klebsiella pneumoniae , Brasil , Farmacorresistencia Bacteriana Múltiple/genética , Galanina/análogos & derivados , Humanos , Klebsiella pneumoniae/genética , Plásmidos/genética , Análisis de Secuencia de ADN , Sustancia P/análogos & derivados , Virulencia/genética , beta-Lactamasas/genética
10.
ACS Sens ; 7(5): 1248-1268, 2022 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-35452212

RESUMEN

Magnetoelastic resonators are gaining attention as an incredibly versatile and sensitive transduction platform for the detection of varied physical, chemical, and biological parameters. These sensors, based on the coupling effect between mechanical and magnetic properties of ME platforms, stand out in comparison to alternative technologies due to their low cost and wireless detection capability. Several parameters have been optimized over the years to improve their performance, such as their composition, surface functionalization, or shape geometry. In this review, the working principles, recent advances, and future perspectives of magnetoelastic resonance transducers are introduced, highlighting their potentials as a versatile platform for sensing applications. First, the fundamental principles governing the magnetoelastic resonators performance are introduced as well as the most common magnetoelastic materials and their main fabrication methods are described. Second, the versatility and technical feasibility of magnetoelastic resonators for biological, chemical, and physical sensing are highlighted and the most recent results and functionalization processes are summarized. Finally, the forefront advances to further improve the performance of magnetoelastic resonators for sensing applications have been identified.


Asunto(s)
Técnicas Biosensibles , Técnicas Biosensibles/métodos , Magnetismo , Transductores
11.
Animals (Basel) ; 12(3)2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-35158677

RESUMEN

In the wild, mice have developed survival strategies to detect volatile cues that warn them of potential danger. Specific olfactory neurons found in the Grueneberg ganglion olfactory subsystem can detect alarm pheromones emitted by stressed conspecifics, as well as kairomones involuntarily released by their predators. These volatile chemical cues allow intra- and interspecies communication of danger, respectively. Alarm pheromones, kairomones and bitter taste ligands share a common chemical motif containing sulfur or nitrogen. Interestingly, three specific bitter taste receptors (TAS2Rs) have been found in the Grueneberg ganglion neurons that are implicated in danger signalling pathways. We have recently developed a TAS2R-expressing heterologous system that mimics the Grueneberg ganglion neuron responses after kairomone stimulation. Here, we demonstrated by in vitro, ex vivo and in vivo experiments that the biological secretions from the raccoon (Procyon lotor) and the skunk (Mephitis mephitis) were acting as potent sources of kairomones. They activated the Grueneberg ganglion neurons and induced fear-related behaviours in mice. Identification of new sources of semiochemicals is a first step towards an understanding of the interspecies danger communication that takes place in the Grueneberg ganglion.

12.
J Infect Chemother ; 28(3): 363-372, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34815168

RESUMEN

INTRODUCTION: Proteus mirabilis is one of the main pathogens that cause urinary tract infections. Therefore, the aim of this study was to analyze and compare the genetic profile of 36 clinical isolates of P. mirabilis that carry and do not carry the blaKPC and blaNDM gene with respect to virulence factors (mrpG, pmfA, ucaA, nrpG and pbtA) and antimicrobial resistance (blaVIM,blaIMP, blaSPM, blaGES,blaOXA-23-like, blaOXA-48-like, blaOXA-58-like and blaOXA-10-like). METHODS: The virulence and resistance genes were investigated by using PCR and sequencing. RESULTS: ERIC-PCR typing showed that the isolates showed multiclonal dissemination and high genetic variability. The gene that was most found blaOXA-10-like (n = 18), followed by blaKPC (n = 10) and blaNDM (n = 8). To our knowledge, this is the first report of blaOXA-10 in P. mirabilis in Brazil, as well as the first report of the occurrence of P. mirabilis co-carrying blaOXA-10/blaKPC and blaOXA-10/blaNDM. The blaNDM or blaKPC carrier isolates showed important virulence genes, such as ucaA (n = 8/44.4%), pbtA (n = 10/55.5%) and nrpG (n = 2/11.1%). However, in general, the non-carrier isolates of blaKPC and blaNDM showed a greater number of virulence genes when compared to the carrier group. CONCLUSION: Clinical isolates of P. mirabilis, in addition to being multi-drug resistant, presented efficient virulence factors that can establish infection outside the gastrointestinal tract.


Asunto(s)
Proteus mirabilis , Factores de Virulencia , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Brasil , Humanos , Pruebas de Sensibilidad Microbiana , Proteus mirabilis/genética , Factores de Virulencia/genética , beta-Lactamasas/genética
13.
Commun Biol ; 4(1): 880, 2021 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-34267318

RESUMEN

COVID-19 pandemic has given rise to a collective scientific effort to study its viral causing agent SARS-CoV-2. Research is focusing in particular on its infection mechanisms and on the associated-disease symptoms. Interestingly, this environmental pathogen directly affects the human chemosensory systems leading to anosmia and ageusia. Evidence for the presence of the cellular entry sites of the virus, the ACE2/TMPRSS2 proteins, has been reported in non-chemosensory cells in the rodent's nose and mouth, missing a direct correlation between the symptoms reported in patients and the observed direct viral infection in human sensory cells. Here, mapping the gene and protein expression of ACE2/TMPRSS2 in the mouse olfactory and gustatory cells, we precisely identify the virus target cells to be of basal and sensory origin and reveal the age-dependent appearance of viral entry-sites. Our results propose an alternative interpretation of the human viral-induced sensory symptoms and give investigative perspectives on animal models.


Asunto(s)
Ageusia/fisiopatología , Anosmia/fisiopatología , COVID-19/fisiopatología , SARS-CoV-2/fisiología , Factores de Edad , Ageusia/virología , Animales , Anosmia/virología , COVID-19/virología , Femenino , Masculino , Ratones , Percepción Olfatoria , Percepción del Gusto
14.
Rev Soc Bras Med Trop ; 54: e0864-2020, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33759932

RESUMEN

Proteus mirabilis is one of the main pathogens causing urinary tract infections and sepsis. To our knowledge, this is the first report of a P. mirabilis hosting bla GES. The presence of these genes was determined using PCR and sequencing. We identified the presence of bla GES-1 in all three isolates. In addition, we identified the bla KPC-2 and bla NDM-1 genes in the two strains. These data emphasize the importance of monitoring and surveillance of all enterobacteria. The circulation of P. mirabilis strains carrying bla GES-1 constitutes a new scenario of resistance in this species and should be an epidemiological alert for global health.


Asunto(s)
Proteus mirabilis , beta-Lactamasas , Antibacterianos , Enterobacteriaceae , Pruebas de Sensibilidad Microbiana , Proteus mirabilis/genética , beta-Lactamasas/genética
15.
J Ethnopharmacol ; 265: 113248, 2021 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-32805356

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Verbesina macrophylla (Cass.) S.F.Blake is a medicinal plant from South America, popularly known as "asa de peixe", "asa de peixe branco", "cambará branco" or "cambará guaçu", being used by traditional communities for its healing powers in the form of teas, infusions, liqueurs and extracts, for the treatment of bacterial and fungal infections of the urinary and respiratory tracts, such as kidney problems, bronchitis, inflammation and fever. However, none of the ethnopharmacological properties has been scientifically evaluated. AIM OF THE STUDY: Based on the ethnopharmacological use of the species, this study investigated the chemical composition, and for the first time acute toxicity, hemolytic, antimicrobial, anti-inflammatory and antipyretic activities of the essential oil from leaves of V. macrophylla. MATERIAL AND METHODS: The essential oil was obtained from the leaves by hydrodistillation (HD), being characterized by gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography coupled to flame ionization detection (GC-FID). The antimicrobial activity was evaluated by the broth microdilution technique in bacteria and fungi that cause infections of the respiratory and urinary tract, and toxicological safety regarding hemolytic activity on human red blood cells (hRBCs), and acute toxicity in mice. The anti-inflammatory activity was evaluated by the model carrageenan-induced peritonitis with quantification of the levels of TNF-α and IL-1ß in the intraperitoneal fluid, and ear edema induced by croton oil. The antipyretic activity evaluated in mice with pyrexia induced by yeast. RESULTS: The extraction of essential oil by hydrodistillation (HD) showed a yield of 0.33 ±â€¯0.04%, with its composition constituted mainly by sesquiterpenes of hydrocarbons (94.00%). The essential oil demonstrated antibacterial and antifungal activity, with a low rate of hemolysis in human red blood cells (hRBCs) and no clinical signs of toxicity were observed in animals after acute treatment, which suggested that the LD50 is greater than 5000 mg/kg; p.o. The essential oil demonstrated anti-inflammatory activity reducing levels of pro-inflammatory cytokines TNF-α (38.83%, 72.42% and 73.52%) and IL-1ß (37.70%, 75.92% and 87.71%), and ear edema by 49.53%, 85.04% and 94.39% at concentrations of 4, 40 and 400 mg/kg, respectively. The antipyretic activity presented by the essential oil is statistically similar to dipyrone. CONCLUSION: The set of results obtained, validates the main activities attributed to the traditional use of Verbesina macrophylla (Cass.) S.F.Blake. These data add industrial value to the species, considering that the antimicrobial, anti-inflammatory and antipyretic activities present results similar to the drugs already used also presenting safety. The results suggest that essential oil from V. macrophylla may be used by industry for the development of drugs with natural antimicrobial, anti-inflammatory and antipyretic effect.


Asunto(s)
Aceites Volátiles/farmacología , Extractos Vegetales/farmacología , Verbesina/química , Animales , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Antiinflamatorios/aislamiento & purificación , Antiinflamatorios/farmacología , Antipiréticos/aislamiento & purificación , Antipiréticos/farmacología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Eritrocitos/efectos de los fármacos , Femenino , Fiebre/tratamiento farmacológico , Hemólisis/efectos de los fármacos , Humanos , Inflamación/tratamiento farmacológico , Masculino , Ratones , Aceites Volátiles/aislamiento & purificación , Aceites Volátiles/toxicidad , Extractos Vegetales/toxicidad , Hojas de la Planta , Pruebas de Toxicidad Aguda
16.
Rev. Soc. Bras. Med. Trop ; 54: e0864-2020, 2021. tab
Artículo en Inglés | LILACS | ID: biblio-1155547

RESUMEN

Abstract Proteus mirabilis is one of the main pathogens causing urinary tract infections and sepsis. To our knowledge, this is the first report of a P. mirabilis hosting bla GES. The presence of these genes was determined using PCR and sequencing. We identified the presence of bla GES-1 in all three isolates. In addition, we identified the bla KPC-2 and bla NDM-1 genes in the two strains. These data emphasize the importance of monitoring and surveillance of all enterobacteria. The circulation of P. mirabilis strains carrying bla GES-1 constitutes a new scenario of resistance in this species and should be an epidemiological alert for global health.


Asunto(s)
Proteus mirabilis/genética , beta-Lactamasas/genética , Pruebas de Sensibilidad Microbiana , Enterobacteriaceae , Antibacterianos
17.
Rev Soc Bras Med Trop ; 53: e20200397, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33111914

RESUMEN

INTRODUCTION: Antibiotic resistance in carbapenemase-producing Klebsiella pneumoniae is acquired and disseminated mainly by plasmids. Therefore, we aimed to investigate the occurrence of carbapenemase genes, analyze the genetic diversity by ERIC-PCR, and examine the most common plasmid incompatibility groups (Incs) in clinical isolates of K. pneumoniae from colonization and infection in patients from a hospital in Brazil. METHODS: Twenty-seven isolates of carbapenem-resistant K. pneumoniae were selected and screened for the presence of carbapenemase genes and Incs by PCR, followed by amplicon sequencing. RESULTS: The bla KPC and bla NDM genes were detected in 24 (88.8 %) and 16 (59.2 %) of the isolates, respectively. Thirteen isolates (48.1 %) were positive for both genes. The IncFIB (92.6 %) and IncQ (88.8 %) were the most frequent plasmids, followed by IncA/C, IncHI1B, and IncL/M, indicating that plasmid variability existed in these isolates. To our knowledge, this is the first report of IncHI1B in Brazil. We found eight isolates with clonal relationship distributed in different sectors of the hospital. CONCLUSIONS: The accumulation of resistance determinants, the variability of plasmid Incs, and the clonal dissemination detected in K. pneumoniae isolates demonstrate their potential for infection, colonization, and the dissemination of different resistance genes and plasmids.


Asunto(s)
Infecciones por Klebsiella , Klebsiella pneumoniae , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Brasil , Hospitales Públicos , Humanos , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad Microbiana , Plásmidos/genética , beta-Lactamasas/genética
18.
J Assist Reprod Genet ; 37(10): 2581-2603, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32767207

RESUMEN

BACKGROUND: Strong evidence has suggested an important role of telomeres in meiosis, fertilization, and embryo development. PURPOSE: To determine if sperm telomere length (STL) in sperm purified by differential gradient centrifugation followed by swim-up (selected STL) is correlated with sperm quality and clinical outcomes. METHODS: Relative selected STL was assessed by quantitative polymerase chain reaction (Q-PCR) in 78 consecutive assisted reproductive technology (ART) treatments during 2017. Statistical analyses were performed in the totality of patients, and in normozoospermic and non-normozoospermic patients. These included correlations between selected STL and sperm quality parameters, embryological parameters (multivariable linear regression), and clinical parameters (multivariable logistic regression). RESULTS: No significant correlations were found between selected STL and sperm quality in the total population. However, selected STL was significantly correlated with total sperm count (r = 0.361; P = 0.039) and sperm DNA fragmentation-post-acrosomal region pattern (r = - 0.464; P = 0.030) in normozoospermic patients. No relation was observed between selected STL and clinical outcomes in any clinical group. CONCLUSIONS: As the correlations observed in normozoospermic patients were not representative of the whole heterogeneous population, differences in the sperm characteristics of the study population may lead to discrepant results when evaluating the association of STL with sperm quality. Since the total population selected STL was not related with sperm quality and with clinical outcomes, results do not support the use of selected STL measurement to evaluate the reproductive potential of the male patient or to predict the success rates of ART treatments.


Asunto(s)
Técnicas Reproductivas Asistidas , Espermatozoides/citología , Homeostasis del Telómero/genética , Telómero/genética , Adulto , Centrifugación por Gradiente de Densidad , Humanos , Masculino , Persona de Mediana Edad , Recuento de Espermatozoides , Motilidad Espermática/genética , Espermatozoides/crecimiento & desarrollo
19.
Rev Soc Bras Med Trop ; 53: e20190526, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32578705

RESUMEN

INTRODUCTION: This study investigated the genetic environment of bla KPC-2 in Klebsiella pnemoniae multi-drug resistant clinical isolates. METHODS: Four carbapenemase gene isolates resistant to carbapenems, collected from infected patients from two hospitals in Brazil, were investigated using polymerase chain reaction and plasmid DNA sequencing. RESULTS: The bla KPC-2 gene was located between ISKpn6 and a resolvase tnpR in the non-Tn4401 element (NTEKPC-IId). It was detected on a plasmid belonging to the IncQ1 group. CONCLUSIONS: To our knowledge, this is the first report of the presence of the bla KPC-2 gene in the NTEKPC-IId element carried by plasmid IncQ1 from infections in Brazil.


Asunto(s)
Antibacterianos/farmacología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/genética , beta-Lactamasas/genética , ADN Bacteriano/genética , Farmacorresistencia Bacteriana Múltiple , Humanos , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Plásmidos/genética , Reacción en Cadena de la Polimerasa
20.
Chemistry ; 26(61): 13861-13872, 2020 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-32557884

RESUMEN

Acute CrVI water pollution due to anthropogenic activities is an increasing worldwide concern. The high toxicity and mobility of CrVI makes it necessary to develop dual adsorbent/ion-reductive materials that are able to capture CrVI and transform it efficiently into the less hazardous CrIII . An accurate description of chromium speciation at the adsorbent/ion-reductive matrix is key to assessing whether CrVI is completely reduced to CrIII , or if its incomplete transformation has led to the stabilization of highly reactive, transient CrV species within the material. With this goal in mind, a dual ultraviolet-visible and electron paramagnetic spectroscopy approach has been applied to determine the chromium speciation within zirconium-based metal-organic frameworks (MOFs). Our findings point out that the generation of defects at Zr-MOFs boosts CrVI adsorption, whilst the presence of reductive groups on the organic linkers play a key role in stabilizing it as isolated and/or clustered CrIII ions.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...