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1.
Microb Pathog ; 193: 106778, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38972366

RESUMO

Antimicrobial resistance and biofilm formation by microbial pathogens pose a significant challenge to poultry production systems due to the persistent risk of dissemination and compromise of bird health and productivity. In this context, the study aimed to investigate the occurrence of different multiresistance phenotypes and the biofilm-forming ability of Enterobacteriaceae isolated from broiler chicken excreta in poultry production units in Ceará, Brazil. Samples were collected from three distinct broiler breeding facilities and subjected to isolation, identification, antibiotic susceptibility testing, phenotypic screening for ß-lactamases enzymes, and biofilm formation evaluation. Seventy-one strains were identified, being Escherichia coli (37 %) and Proteus mirabilis (32 %), followed by Klebsiella pneumoniae (11 %), Providencia stuartii (9 %), Klebsiella aerogenes (6 %), Alcaligenes faecalis (4 %), and Salmonella sp. (1 %). A significant proportion (87 %) of multiresistant strains were detected. For the phenotypic evaluation of ß-lactamases production, strains with resistance to second and third-generation cephalosporins and carbapenems were tested. About 4 of 6 and 10 of 26 were positive for inducible chromosomal AmpC ß-lactamase and extended-spectrum ß-lactamase (ESBL), respectively. Regarding biofilm formation, it was observed that all MDR strains were capable of forming biofilm. In this sense the potential of these MDR bacteria to develop biofilms becomes a significant concern, representing a real threat to both human and animal health, as biofilms offer stability, antimicrobial protection, and facilitate genetic transfer.


Assuntos
Antibacterianos , Biofilmes , Galinhas , Farmacorresistência Bacteriana Múltipla , Enterobacteriaceae , Fazendas , Fezes , Testes de Sensibilidade Microbiana , beta-Lactamases , Animais , Biofilmes/crescimento & desenvolvimento , Biofilmes/efeitos dos fármacos , Brasil , beta-Lactamases/genética , beta-Lactamases/metabolismo , Fezes/microbiologia , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Enterobacteriaceae/genética , Antibacterianos/farmacologia , Galinhas/microbiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Aves Domésticas/microbiologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/veterinária
2.
Amino Acids ; 55(8): 1003-1012, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37442853

RESUMO

Candida albicans is considered one of the most important opportunistic fungi due to the large arsenal of virulence factors that help throughout the progress of the infection. In this sense, antimicrobial peptides (AMPs) appear as an alternative, with great antifungal action. Among these, aurein 1.2 has been widely explored, becoming the basis for the discovery of new AMPs, such as K-aurein (K-au). Thus, this study evaluated the anti-C. albicans potential of K-au against virulence factors, planktonic growth, and biofilm formation of clinical isolates. Firstly, K-au antifungal activity was determined by the microdilution method and time-kill curve. The inhibition of hydrolytic enzyme secretion (proteinase, phospholipase, and hemolysin) and germ tube formation was tested. Then, the antibiofilm potential of K-au was verified through biomass quantification and scanning electron microscopy (SEM). All tests were compared with the classical antifungal drug, amphotericin B (AmB). The outcomes showed fungicidal action of K-au at 62.50 µg mL-1 for all isolates, with a time of action around 150-180 min, determined by the time-kill curve. K-au-treated cells decreased by around 40% of the germinative tube compared to the control. Additionally, K-au inhibited the biofilm formation by more than 90% compared to AmB and the control group. SEM images show apparent cellular disaggregation without the formation of filamentous structures. Therefore, the findings suggest a promising anti-C. albicans effect of K-au due to its fungicidal activity against planktonic cells, or its ability to inhibit important virulence factors like germ tube and biofilm formation. Thus, this peptide could be explored as a useful compound against C. albicans-related infection.


Assuntos
Antifúngicos , Candida albicans , Antifúngicos/farmacologia , Antifúngicos/química , Biomassa , Testes de Sensibilidade Microbiana , Anfotericina B/farmacologia , Fatores de Virulência/farmacologia , Biofilmes
3.
Biofouling ; : 1-10, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36597191

RESUMO

This work investigates the ability of two Croton spp. essential oils (EO) to enhance chlorhexidine (CHX) activity against oral streptococci. EO's chemical composition of Croton argyrophyllus and C. pluriglandulosus was determined by GC-MS/FID. The microbial growth kinetics and minimum inhibitory concentration (MIC) of EOs and CHX were determined, followed by their synergism against S. mutans UA159 and ATCC 25175, S. salivarius ATCC 7073 and S. sp. ATCC 15300. The microplate-based method was used to determine the EO/CHX activity against 24-h-old biofilms. The major compounds were α-pinene (54.74%) and bicyclogermacrene (16.08%) for EOAr and 1,8-cineole (17.41%), methyleugenol (16.06%) and elemicin (15.99%) for EOPg. Both EO had MIC around 16,000 µg/mL. EOs/CHX presented a synergistic effect against most strains (FICi from 0.133 to 0.375), and OE/CHX-treated biofilms showed a reduction in biomass and cell viability compared to CHX, only (p < 0.01). Thus, the EOs works as natural adjuvants for CHX.

4.
Lett Appl Microbiol ; 76(1)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36688748

RESUMO

The aim of this work was to evaluate the anti-Escherichia coli effect of cell-free supernatant (CFS) of Lactobacillus spp. against planktonic and biofilm forms of foodborne isolates. Escherichiacoli strains (P12, P25, P35 and P36), previously isolated from fresh filets of fish, were subjected to antimicrobial susceptibility determination by the disc-diffusion agar method. Subsequently, the antagonistic effect between probiotic and pathogenic strains was determined by spot overlay assay. Finally, the CFS activity against pre-established (12 h) biofilms was demonstrated through biomass quantification by crystal violet staining and scanning electron microscopy (SEM). All isolates presented some pattern of resistance, primarily to ampicillin and tetracycline. Probiotic strains presented high antagonistic effects against all E. coli strains, presenting inhibition zones (R) ranging from 15.60 to 20.67 mm. Additionally, the residual biomass of pre-established (12 h) biofilm was drastically reduced about 50% after CFS treatment (P < 0.01). What can be noted by SEM images, which show less surface-attached cells of CFS-treated biofilms of E. coli (P12). Thus, cell-free preparations produced from Lactobacillus spp. may represent a tool in the battle against planktonic cells and biofilm forms of antibiotic-resistant E. coli.


Assuntos
Escherichia coli , Animais , Lactobacillus , Biofilmes , Antibacterianos/farmacologia
5.
Microb Pathog ; 156: 104934, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33962005

RESUMO

The aim of this work was to evaluate the chemical composition and antibacterial activity of Croton tetradenius Baill. (CTEO) and C. pulegiodorus Baill. (CPEO) essential oils against Staphylococcus aureus, and their synergism with antibiotics. The essential oils (EOs) were extracted by hydrodistillation and chemically characterized by gas chromatography-mass spectrometry (CG-MS) and gas chromatography with flame ionization detection (CG-FID). The antimicrobial action of the EOs was tested against two standard strains and four clinical isolates of S. aureus using the disk-diffusion agar method and the microdilution assay. The bacterial kinetic growth was also determined. The synergistic effect between EOs and antimicrobials was analyzed by the checkerboard test. CTEO and CPEO yielded 0.47 and 0.37% w/w and the most common components were p-cymene (28.24%), camphor (17.76%) and α-phellandrene (8.98%), and trans-chrysanthenyl acetate (27.05%), α-terpinene (19.21%) and p-cymene (12.27%), respectively. The disk-diffusion test showed that the bacteria are sensitive to the agents tested. The MIC in the presence of the CTEO it was 4000 µg/mL, while for the CPEO it was 8000 µg/mL, except for clinical isolate 4B. The MBC for strains treated with CTEO were 8000 µg/mL, with the exception of isolates 8B and 0 A 4000 µg/mL. For the CPEO, all strains showed a concentration above 8000 µg/mL. The growth curve showed that CTEO and CPEO altered growth kinetics, delaying the lag phase and reducing the log phase. In combination with antibiotics, both essential oils showed synergisms effect with oxacillin and ampicillin, and additive effect with benzylpenicillin. CTEO and CPEO showed antibacterial action against S. aureus strains, showing as a promise natural alternative in clinical therapy.


Assuntos
Anti-Infecciosos , Croton , Óleos Voláteis , Antibacterianos/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Staphylococcus aureus
6.
Sensors (Basel) ; 20(13)2020 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-32635443

RESUMO

The relative simplicity of IoT networks extends service vulnerabilities and possibilities to different network failures exhibiting system weaknesses. Therefore, having a dataset with a sufficient number of samples, labeled and with a systematic analysis, is essential in order to understand how these networks behave and detect traffic anomalies. This work presents DAD: a complete and labeled IoT dataset containing a reproduction of certain real-world behaviors as seen from the network. To approximate the dataset to a real environment, the data were obtained from a physical data center, with temperature sensors based on NFC smart passive sensor technology. Having carried out different approaches, performing mathematical modeling using time series was finally chosen. The virtual infrastructure necessary for the creation of the dataset is formed by five virtual machines, a MQTT broker and four client nodes, each of them with four sensors of the refrigeration units connected to the internal IoT network. DAD presents a seven day network activity with three types of anomalies: duplication, interception and modification on the MQTT message, spread over 5 days. Finally, a feature description is performed, so it can be used for the application of the various techniques of prediction or automatic classification.

7.
J Med Internet Res ; 21(6): e12554, 2019 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-31199323

RESUMO

BACKGROUND: Major depressive disorder (MDD) or depression is among the most prevalent psychiatric disorders, affecting more than 300 million people globally. Early detection is critical for rapid intervention, which can potentially reduce the escalation of the disorder. OBJECTIVE: This study used data from social media networks to explore various methods of early detection of MDDs based on machine learning. We performed a thorough analysis of the dataset to characterize the subjects' behavior based on different aspects of their writings: textual spreading, time gap, and time span. METHODS: We proposed 2 different approaches based on machine learning singleton and dual. The former uses 1 random forest (RF) classifier with 2 threshold functions, whereas the latter uses 2 independent RF classifiers, one to detect depressed subjects and another to identify nondepressed individuals. In both cases, features are defined from textual, semantic, and writing similarities. RESULTS: The evaluation follows a time-aware approach that rewards early detections and penalizes late detections. The results show how a dual model performs significantly better than the singleton model and is able to improve current state-of-the-art detection models by more than 10%. CONCLUSIONS: Given the results, we consider that this study can help in the development of new solutions to deal with the early detection of depression on social networks.


Assuntos
Inteligência Artificial/normas , Depressão/psicologia , Aprendizado de Máquina/normas , Tecnologia de Sensoriamento Remoto/métodos , Rede Social , Feminino , Humanos , Masculino
8.
Molecules ; 24(21)2019 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-31717766

RESUMO

The study investigated the antimicrobial activity of the essential oil extract of Ocimum gratissimum L. (EOOG) against multiresistant microorganisms in planktonic and biofilm form. Hydrodistillation was used to obtain the EOOG, and the analysis of chemical composition was done by gas chromatography coupled with mass spectrometry (GC/MS) and flame ionization detection (GC/FID). EOOG biological activity was verified against isolates of Staphylococcus aureus and Escherichia coli, using four strains for each species. The antibacterial action of EOOG was determined by disk diffusion, microdilution (MIC/MBC), growth curve under sub-MIC exposure, and the combinatorial activity with ciprofloxacin (CIP) and oxacillin (OXA) were determined by checkerboard assay. The EOOG antibiofilm action was performed against the established biofilm and analyzed by crystal violet, colony-forming unit count, and SEM analyses. EOOG yielded 1.66% w/w, with eugenol as the major component (74.83%). The MIC was 1000 µg/mL for the most tested strains. The growth curve showed a lag phase delay for both species, mainly S. aureus, and reduced the growth level of E. coli by half. The combination of EOOG with OXA and CIP led to an additive action for S. aureus. A significant reduction in biofilm biomass and cell viability was verified for S. aureus and E. coli. In conclusion, EOOG has relevant potential as a natural alternative to treat infections caused by multiresistant strains.


Assuntos
Escherichia coli/efeitos dos fármacos , Ocimum/química , Óleos Voláteis/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Ciprofloxacina/farmacologia , Oxacilina/farmacologia
9.
Proc Natl Acad Sci U S A ; 111(47): 16937-42, 2014 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-25385614

RESUMO

Chronic pain resulting from inflammatory and neuropathic disorders causes considerable economic and social burden. Pharmacological therapies currently available for certain types of pain are only partially effective and may cause severe adverse side effects. The C5a anaphylatoxin acting on its cognate G protein-coupled receptor (GPCR), C5aR, is a potent pronociceptive mediator in several models of inflammatory and neuropathic pain. Although there has long been interest in the identification of C5aR inhibitors, their development has been complicated, as for many peptidomimetic drugs, mostly by poor drug-like properties. Herein, we report the de novo design of a potent and selective C5aR noncompetitive allosteric inhibitor, DF2593A, guided by the hypothesis that an allosteric site, the "minor pocket," previously characterized in CXC chemokine receptors-1 and -2, is functionally conserved in the GPCR class. In vitro, DF2593A potently inhibited C5a-induced migration of human and rodent neutrophils. In vivo, oral administration of DF2593A effectively reduced mechanical hyperalgesia in several models of acute and chronic inflammatory and neuropathic pain, without any apparent side effects. Mechanical hyperalgesia after spared nerve injury was also reduced in C5aR(-/-) mice compared with WT mice. Furthermore, treatment of C5aR(-/-) mice with DF2593A did not produce any further antinociceptive effect compared with C5aR(-/-) mice treated with vehicle. The successful medicinal chemistry strategy confirms that a conserved minor pocket is amenable for the rational design of selective inhibitors and the pharmacological results support that the allosteric blockade of the C5aR represents a highly promising therapeutic approach to control chronic inflammatory and neuropathic pain.


Assuntos
Analgésicos/uso terapêutico , Inflamação/tratamento farmacológico , Neuralgia/tratamento farmacológico , Receptor da Anafilatoxina C5a/efeitos dos fármacos , Administração Oral , Regulação Alostérica , Analgésicos/química , Animais , Modelos Animais de Doenças , Desenho de Fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Ratos
10.
Res Vet Sci ; 170: 105182, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38377791

RESUMO

The increasing prevalence of antimicrobial resistance among bacterial pathogens necessitates novel treatment strategies, particularly in veterinary medicine where otitis in dogs is very common in small animals' clinical routines. Considering this challenge, this study explores the efficacy of aromatic plant compounds (APC), including eugenol (EUG), trans-cinnamaldehyde (TC), and geraniol (GER), and their synergistic potential when combined with the antiseptic agent chlorhexidine (CLX), offering insight into alternative therapeutic approaches. The disk diffusion assay revealed differential sensitivity of Staphylococcus spp. strains to the tested compounds, with EUG and GER showing moderate inhibition zones and TC displaying considerably larger inhibition zones. Further analysis through MIC and MBC determinations suggested that EUG required the highest concentrations to inhibit and kill the bacteria, whereas TC and GER were effective at lower concentrations. Combined with CLX, all three plant-derived compounds demonstrated a significant enhancement of antibacterial activity, indicated by reduced MIC values and a predominantly synergistic interaction across the strains tested. GER was the most potent in combination with CLX, presenting the lowest mean FICi values and the highest fold reductions in MIC. This study emphasizes the APC's potential as an adjunct to conventional antimicrobial agents like CLX. The marked synergy observed, especially with GER, suggests that such combinations could be promising alternatives in managing bacterial otitis in dogs, potentially mitigating the impact of antibiotic resistance.


Assuntos
Clorexidina/análogos & derivados , Doenças do Cão , Otite , Cães , Animais , Clorexidina/farmacologia , Clorexidina/uso terapêutico , Staphylococcus , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Otite/veterinária , Eugenol , Testes de Sensibilidade Microbiana/veterinária , Sinergismo Farmacológico , Doenças do Cão/tratamento farmacológico , Doenças do Cão/microbiologia
11.
Braz J Microbiol ; 55(2): 1647-1654, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38374323

RESUMO

The Enterobacteriaceae family is recognized as a primary group of Gram-negative pathogens responsible for foodborne illnesses and is frequently associated with antibiotic resistance. The present study explores the natural-based compound trans-cinnamaldehyde (TC) against drug-resistant Enterobacteriaceae and its synergism with gentamicin (GEN) to address this issue. The research employs three strains of Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae, previously isolated from shrimp. The antibacterial activity was evaluated by the disk diffusion method, microdilution test, kinetics of growth, and time-kill curve. In addition, the synergistic effect between TC/GEN was investigated by checkerboard assay. All strains showed sensitivity to TC with an inhibition zone diameter > 35 mm. The TC showed inhibitory and bactericidal action in the most tested bacteria around 625 µg/mL. Sub-inhibitory amounts (1/2 and 1/4 MIC) of TC interfered with the growth kinetics by lag phase extension and decreased the log phase. Time-kill curves show a reduction of viable cells after the first hour of TC treatment at bactericidal concentrations. The synergistic effect between TC/GEN was observed for E. coli and E. cloacae strains with FICi ranging from 0.15 to 0.50. These findings, therefore, suggest TC as a promising alternative in the fight against drug-resistant Enterobacteriaceae that can cause foodborne illnesses.


Assuntos
Acroleína , Antibacterianos , Sinergismo Farmacológico , Enterobacteriaceae , Gentamicinas , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Gentamicinas/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/crescimento & desenvolvimento , Acroleína/análogos & derivados , Acroleína/farmacologia , Animais , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle
12.
Molecules ; 18(5): 5792-803, 2013 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-23685936

RESUMO

Rhizobium tropici is a Gram-negative bacterium that induces nodules and fixed atmospheric nitrogen in symbiotic association with Phaseolus vulgaris (common bean) and some other leguminous species. Lectins are proteins that specifically bind to carbohydrates and, consequently, modulate different biological functions. In this study, the d-glucose/ d-mannose-binding lectins (from seeds of Dioclea megacarpa, D. rostrata and D. violacea) and D-galactose-binding lectins (from seeds of Bauhinia variegata, Erythina velutina and Vatairea macrocarpa) were purified using chromatographic techniques and evaluated for their effect on the growth of R. tropici CIAT899. All lectins were assayed with a satisfactory degree of purity according to SDS-PAGE analysis, and stimulated bacterial growth; in particular, the Dioclea rostrata lectin was the most active among all tested proteins. As confirmed in the present study, both d-galactose- and d-glucose/d-mannose-binding lectins purified from the seeds of leguminous plants may be powerful biotechnological tools to stimulate the growth of R. tropici CIAT99, thus improving symbiotic interaction between rhizobia and common bean and, hence, the production of this field crop.


Assuntos
Fabaceae/química , Lectinas de Plantas , Rhizobium tropici/crescimento & desenvolvimento , Sementes/química , Lectinas de Plantas/química , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/farmacologia
13.
Protein Pept Lett ; 30(8): 690-698, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37488753

RESUMO

BACKGROUND: Antimicrobial resistance is an emerging global health challenge that has led researchers to study alternatives to conventional antibiotics. A promising alternative is antimicrobial peptides (AMPs), produced as the first line of defense by almost all living organisms. To improve its biological activity, the conjugation of AMPs is a promising approach. OBJECTIVE: In this study, we evaluated the N-terminal conjugation of p-Bt (a peptide derived from Bothrops Jararacuçu`s venom) with ferrocene (Fc) and gallic acid (GA). Acetylated and linear versions of p-Bt were also synthesized to evaluate the importance of N-terminal charge and dimeric structure. METHODS: The compounds were obtained using solid-phase peptide synthesis. Circular dichroism, vesicle permeabilization, antimicrobial activity, and cytotoxicity studies were conducted. RESULTS: No increase in antibacterial activity against Escherichia coli was observed by adding either Fc or GA to p-Bt. However, Fc-p-Bt and GA-p-Bt exhibited improved activity against Staphylococcus aureus. No cytotoxicity upon fibroblast was observed for GA-p-Bt. On the other hand, conjugation with Fc increased cytotoxicity. This toxicity may be related to the membrane permeabilization capacity of this bioconjugate, which showed the highest carboxyfluorescein leakage in vesicle permeabilization experiments. CONCLUSION: Considering these observations, our findings highlight the importance of adding bioactive organic compounds in the N-terminal position as a tool to modulate the activity of AMPs.


Assuntos
Peptídeos Catiônicos Antimicrobianos , Ácido Gálico , Antibacterianos/farmacologia , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Escherichia coli , Ácido Gálico/farmacologia , Metalocenos/farmacologia , Testes de Sensibilidade Microbiana , Peptídeos/química , Peptídeos/farmacologia , Lisina/química , Lisina/farmacologia
14.
Mar Drugs ; 10(9): 1936-1954, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23118713

RESUMO

Lectins are a structurally heterogeneous group of proteins that have specific binding sites for carbohydrates and glycoconjugates. Because of their biotechnological potential, lectins are widely used in biomedical research. The present study aimed to evaluate the healing potential of the lectin isolated from the marine red alga Bryothamnion seaforthii (BSL). The lectin was purified using ion exchange chromatography with DEAE cellulose and characterized using tandem mass spectrometry. For healing tests, skin wounds were induced in the dorsal thoracic region of mice. These animals were randomly divided into three groups and subjected to topical treatment for 12 days with BSL, bovine serum albumin and 150 mM NaCl. To evaluate the potential of each treatment, the animals were anesthetized and sacrificed on days 2, 7 and 12, respectively. The parameters evaluated included the wound area, the proportion of wound closure and the histological diagnosis. The wound closure was more effective with BSL (Postoperative Day 7 and 12) than controls. The luminal epithelium was completely restructured; the presence of collagen in the dermis and the strongly active presence of young skin annexes demonstrate the potential of treatment with BSL compared with controls. Our findings suggest that BSL has pro-healing properties and can be a potential medical process in the treatment of acute wounds.


Assuntos
Lectinas/química , Lectinas/farmacologia , Rodófitas/química , Cicatrização/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Derme/efeitos dos fármacos , Masculino , Camundongos , Dados de Sequência Molecular , Isoformas de Proteínas , Análise de Sequência de Proteína
15.
Molecules ; 17(5): 5244-54, 2012 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-22565477

RESUMO

To study the interactions between a Rhizobium tropici strain and lectins isolated from the seeds of Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr), a lectin fluorescence assay was performed. In addition, an experiment was designed to evaluate the effect of the two lectins on bacterial growth. Both lectins were found to bind to R. tropici cells, but the interactions were inhibited by D-mannose. Interestingly, only ConBr stimulated bacterial growth in proportion to the concentrations used (15.6-500 µg/mL), and the bacterial growth stimulation was inhibited by D-mannose as well. Structure/Function analyses by bioinformatics were carried out to evaluate the volume and carbohydrate recognition domain (CRD) configuration of ConA and ConBr. The difference of spatial arrangement and volume of CRD may indicate the variation between biological activities of both lectins. The results suggest that ConBr could be a promising tool for studies focusing on the interactions between rhizobia and host plants.


Assuntos
Canavalia/química , Lectinas de Plantas/farmacologia , Rhizobium tropici/efeitos dos fármacos , Sementes/química , Bioensaio , Relação Dose-Resposta a Droga , Fluoresceína-5-Isotiocianato , Corantes Fluorescentes , Manose/farmacologia , Modelos Moleculares , Fixação de Nitrogênio/fisiologia , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/metabolismo , Ligação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Rhizobium tropici/fisiologia , Espectrometria de Fluorescência , Relação Estrutura-Atividade
16.
Molecules ; 16(5): 3530-43, 2011 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-21525793

RESUMO

Surface colonization is an essential step in biofilm development. The ability of oral pathogens to adhere to tooth surfaces is directly linked with the presence of specific molecules at the bacterial surface that can interact with enamel acquired pellicle ligands. In light of this, the aim of this study was to verify inhibitory and antibiofilm action of lectins from the Diocleinaesubtribe against Streptococcus mutans and Streptococcus oralis. The inhibitory action against planctonic cells was assessed using lectins from Canavaliaensi formis (ConA), Canavalia brasiliensis (ConBr), Canavalia maritima (ConM), Canavalia gladiata (CGL) and Canavalia boliviana (ConBol). ConBol, ConBr and ConM showed inhibitory activity on S. mutans growth. All lectins, except ConA, stimulated significantly the growth of S. oralis. To evaluate the effect on biofilm formation, clarified saliva was added to 96-well, flat-bottomed polystyrene plates, followed by the addition of solutions containing 100 or 200 µg/mL of the selected lectins. ConBol, ConM and ConA inhibited the S. mutans biofilms. No effects were found on S. oralis biofilms. Structure/function analysis were carried out using bioinformatics tools. The aperture and deepness of the CRD (Carbohydrate Recognition Domain) permit us to distinguish the two groups of Canavalia lectins in accordance to their actions against S. mutans and S. oralis. The results found provide a basis for encouraging the use of plant lectins as biotechnological tools in ecological control and prevention of caries disease.


Assuntos
Biofilmes/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Streptococcus/efeitos dos fármacos , Streptococcus/crescimento & desenvolvimento , Concanavalina A/farmacologia , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus oralis/efeitos dos fármacos , Streptococcus oralis/crescimento & desenvolvimento
17.
Molecules ; 16(11): 9298-315, 2011 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-22064270

RESUMO

Lectins are a structurally heterogeneous group of highly specific carbohydrate-binding proteins. Due to their great biotechnological potential, lectins are widely used in biomedical research. The purpose of the present study was to evaluate the healing potential of the lectin of Bauhinia variegata (nBVL) and its recombinant isoform (rBVL-1). Following surgical creation of dorsal skin wounds, seven groups of mice were submitted to topical treatment for 12 days with lectin, D-galactose, BSA and saline. The animals were anesthetized and euthanized on POD 2, 7 and 12 in order to evaluate the healing potential of each treatment. The parameters considered included wound size, contraction rate, epithelialization rate and histopathological findings. Wound closure was fastest in animals treated with rBVL-1 (POD 7). nBVL was more effective than the controls. All skin layers were reconstructed and keratin deposition increased. Our findings indicate that the lectin of Bauhinia variegata possesses pro-healing properties and may be employed in the treatment of acute skin wounds.


Assuntos
Bauhinia/química , Lectinas de Plantas/farmacologia , Isoformas de Proteínas/farmacologia , Proteínas Recombinantes/farmacologia , Pele , Cicatrização/efeitos dos fármacos , Animais , Procedimentos Cirúrgicos Dermatológicos , Masculino , Camundongos , Lectinas de Plantas/genética , Isoformas de Proteínas/genética , Distribuição Aleatória , Proteínas Recombinantes/genética , Pele/efeitos dos fármacos , Pele/patologia
18.
Antibiotics (Basel) ; 11(1)2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-35052881

RESUMO

The aim of this study was to evaluate the phytochemical profile of Cinnamomum zeylanicum essential oil (CZEO) and their antimicrobial and antibiofilm activity against Staphylococcus strains isolated from canine otitis. First, the CZEO chemical composition was determined by gas chromatography-mass spectrometry (CG-MS). External otitis samples collected from dogs were submitted to staphylococcal isolation, followed by MALDI-TOF mass spectrometry identification. The antimicrobial action was tested against the isolates using the disk-diffusion and microdilution methods. The antibiofilm activity was evaluated by CZEO-based concentrations, subMIC for biofilm formation and supraMIC against preformed biofilm, quantified by crystal violet (CV) staining and CFU counting. The chemical analysis revealed that (E)-cinnamaldehyde, eugenol and (E)-cinnamyl acetate were the main compounds in the CZEO, representing 77.42, 8.17 and 4.50%, respectively. Two strains of three different species, S. saprophyticus, S. schleiferi and S. pseudintermedius, were identified. The disk-diffusion test showed an inhibitory zone diameter, ranging from 34.0 to 49.5 mm, while the MIC and MBC values were around 500 and 1000 µg/mL. SubMIC demonstrated an inhibition on biofilm formation against 4 out the 6 strains tested. On mature biofilm, the CZEO-based supraMIC groups had slightly change on biomass, however, the biofilm cell viability decreased the CFU in 3 magnitude orders.

19.
Molecules ; 16(1): 190-201, 2010 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-21193844

RESUMO

Croton nepetaefolius is a native plant from northeastern Brazil that belongs to the Euphorbiaceae family. The biological action of this plant has been extensively explored, being the secondary metabolites responsible for its properties alkaloids, diterpenes, and triterpenes. This study aimed to evaluate the ability of casbane diterpene (CD), isolated from the ethanolic extract of C. nepetaefolius, to inhibit microbial growth and biofilm formation of several clinical relevant species (bacteria and yeasts). It was found that CD possessed biocidal and biostatic activity against the majority of the species screened, with minimal active concentrations ranging between 125 and 500 µg/mL. In addition, it was observed that biofilm formation was inhibited even when the planktonic growth was not significantly affected. In conclusion, CD showed potential to be a natural tool for the treatment of diseases caused by different infectious microorganisms.


Assuntos
Anti-Infecciosos/farmacologia , Biofilmes , Diterpenos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/prevenção & controle , Croton/química , Fungos/efeitos dos fármacos , Micoses/prevenção & controle , Extratos Vegetais/farmacologia
20.
J Surg Case Rep ; 2020(3): rjaa006, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32269750

RESUMO

Testicular germ cell tumours (TGCTs) are relatively rare overall and are mainly encountered in young adults and teenagers. The 'burned-out' phenomenon refers to the spontaneous regression of the primary testicular lesion, generally with the presence of a metastatic germ cell tumour. Regressed tumours with retroperitoneal metastasis, as the first manifestation, represent difficult cases prone to misdiagnosis. Burned-out TGCT is a rare but well-recognized entity, with defined clinical features and diagnostic criteria; however, its etiopathogenesis is still not well defined.We present a case of 37-year-old man with a retroperitoneal mass adjacent to the duodenum identified on CT scan. After surgical excision, histopathologic findings evidenced metastatic non-seminomatous GCT. Testicular examination was normal, but a right testis suspicious lesion was found on ultrasound study. Radical right orchidectomy was performed, and histological examination showed complete regression of TGCT. He underwent first-line chemotherapy with complete response and no evidence of recurrence.

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