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1.
J Environ Pathol Toxicol Oncol ; 38(3): 205-216, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31679308

RESUMO

Artemisia vulgaris is a traditional Chinese herb believed to have a wide range of healing properties; it is traditionally used to treat numerous health ailments. The plant is commonly called mugwort or riverside wormwood. The plant is edible, and in addition to its medicinal properties, it is also used as a culinary herb in Asian cooking in the form of a vegetable or in soup. The plant has garnered the attention of researchers in the past few decades, and several research studies have investigated its biological effects, including antioxidant, anti-inflammatory, anticancer, hypolipidemic, and antimicrobial properties. In this review, various studies on these biological effects are discussed along with the tests conducted, compounds involved, and proposed mechanisms of action. This review will be of interest to the researchers working in the field of herbal medicine, pharmacology, medical sciences, and immunology.


Assuntos
Artemisia/química , Fitoterapia , Extratos Vegetais/farmacologia , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Hipolipemiantes/farmacologia , Plantas Medicinais/química
2.
J Agric Food Chem ; 67(42): 11684-11693, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31564105

RESUMO

Enzymatic acylation is commonly used to increase the lipophilicity of flavonoids. However, the absence of primary hydroxyl groups makes it challenging to acylate baicalin using traditional acylation methods. In this study, an enzymatic esterification strategy was developed to introduce fatty-acid chains into baicalin at its carboxyl group, hence successfully synthesizing a new series of baicalin ester derivatives in nonaqueous media. Under the optimal reaction conditions, up to 95% conversion of baicalin was achieved. Antimicrobial evaluation of the baicalin ester derivatives indicated a corresponding increase to that of C log P values, with a cutoff effect at C log P = 5.2. Baicalin ester derivatives with C log P values of 4.9-5.2 exhibited the most potent antimicrobial activity. Interestingly, the introduction of medium-length fatty alcohol chains not only increased lipophilicity but also endowed them with membrane-disrupting properties. This study, therefore, provides an understanding of the esterification of flavonoid glycosides and a prospective application of the ester derivatives.


Assuntos
Anti-Infecciosos/química , Flavonoides/química , Lipase/química , Acilação , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Biocatálise , Esterificação , Ácidos Graxos/química , Flavonoides/farmacologia , Leveduras/efeitos dos fármacos
3.
Artigo em Inglês | MEDLINE | ID: mdl-31522664

RESUMO

From 1 January to 31 December 2017, 36 institutions around Australia participated in the Australian Enterococcal Sepsis Outcome Programme (AESOP). The aim of AESOP 2017 was to determine the proportion of enterococcal bacteraemia isolates in Australia that were antimicrobial resistant, and to characterise the molecular epidemiology of the E. faecium isolates. Of the 1,137 unique episodes of bacteraemia investigated, 95.2% were caused by either E. faecalis (52.9%) or E. faecium (42.3%). Ampicillin resistance was not detected in E. faecalis but in 89.6% of E. faecium. Vancomycin non-susceptibility was reported in 0.3% and 47.0% of E. faecalis and E. faecium respectively. Overall 50.9% of E. faecium harboured vanA or vanB genes. For the vanA/B positive E. faecium isolates, 49.6% harboured vanB genes and 49.2% vanA genes; 1.2% harboured vanA and vanB genes. The percentage of E. faecium bacteraemia isolates resistant to vancomycin in Australia is significantly higher than that seen in most European countries. E. faecium consisted of 76 multilocus sequence types (STs) of which 77% of isolates were classified into nine major STs containing ten or more isolates. All major STs belong to clonal cluster (CC) 17, a major hospital-adapted polyclonal E. faecium cluster. Seven of the nine predominant STs (ST80, ST1421, ST17, ST296, ST555, ST203 and ST18) were found across most regions of Australia. The most predominant clone was ST17 which was identified in all regions except the Australian Capital Territory, the Northern Territory and Tasmania. Overall 60.7% of isolates belonging to the nine predominant STs harboured vanA or vanB genes. The AESOP 2017 has shown enterococcal bacteraemias in Australia are frequently caused by polyclonal ampicillin-resistant high-level gentamicin resistant vanA or vanB E. faecium which have limited treatment options.


Assuntos
Anti-Infecciosos/farmacologia , Bacteriemia/epidemiologia , Farmacorresistência Bacteriana Múltipla , Enterococcus/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Bacteriemia/microbiologia , Criança , Pré-Escolar , Enterococcus/classificação , Enterococcus/genética , Enterococcus faecalis/classificação , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/genética , Enterococcus faecium/classificação , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/genética , Feminino , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Adulto Jovem
4.
Artigo em Inglês | MEDLINE | ID: mdl-31522665

RESUMO

From 1 January to 31 December 2017, 36 institutions around Australia participated in the Australian Staphylococcus aureus Sepsis Outcome Programme (ASSOP). The aim of ASSOP 2017 was to determine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that are antimicrobial resistant, with particular emphasis on susceptibility to methicillin and to characterise the molecular epidemiology of the methicillin-resistant isolates. A total of 2,515 S. aureus bacteraemia episodes were reported, of which 77% were community-onset. Approximately one in five S. aureus (19.0%) were methicillin resistant. The 30-day all-cause mortality associated with methicillin-resistant SAB was 18.7% which was significantly higher than the 14.0% mortality associated with methicillin-susceptible SAB. With the exception of the ß-lactams and erythromycin, antimicrobial resistance in methicillin-susceptible S. aureus was rare. However in addition to the ß-lactams approximately 42% of methicillin-resistant S. aureus (MRSA) were resistant to erythromycin and ciprofloxacin and approximately 14% resistant to co-trimoxazole, tetracycline and gentamicin. When applying the EUCAST breakpoints teicoplanin resistance was detected in five S. aureus isolates. Resistance was not detected for vancomycin and linezolid. Resistance to non-beta-lactam antimicrobials was largely attributable to two healthcare-associated MRSA clones: ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA). ST22-IV [2B] (EMRSA-15) is the predominant healthcare-associated clone in Australia. Seventy-five percent of methicillin-resistant SAB were due to community-associated clones. Although polyclonal approximately 74% of community-associated clones were characterised as ST93-IV [2B] (Queensland CA-MRSA), ST5-IV [2B], ST45-VT [5C2&5] and ST1-IV [2B]. CA-MRSA, in particular the ST45-VT [5C2&5] clone has acquired multiple antimicrobial resistance determinants including ciprofloxacin, erythromycin, clindamycin, gentamicin and tetracycline. ST45-VT [5C2&5] accounted for 12.8% of CA-MRSA. As CA-MRSA is well established in the Australian community it is important antimicrobial resistance patterns in community- and healthcare-associated SAB is monitored as this information will guide therapeutic practices in treating S. aureus sepsis.


Assuntos
Anti-Infecciosos/farmacologia , Bacteriemia/epidemiologia , Farmacorresistência Bacteriana Múltipla , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/efeitos dos fármacos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Bacteriemia/microbiologia , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Pessoa de Meia-Idade , Epidemiologia Molecular , Infecções Estafilocócicas/microbiologia , Adulto Jovem
5.
J Agric Food Chem ; 67(41): 11288-11306, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31557009

RESUMO

Delphinidin (Del) and its glycosides are water-soluble pigments, belonging to a subgroup of flavonoids. They are health-promoting candidates for pharmaceutical and nutraceutical uses, as indicated by exhibiting antioxidation, anti-inflammation, antimicroorganism, antidiabetes, antiobesity, cardiovascular protection, neuroprotection, and anticancer properties. Glycosylation modification of Del is associated with increased stability and reduced biological activity. Del and its glycosides can be the alternative inhibitors of CBRs, ERα/ß, EGFR, BCRP, and SGLT-1, and virtual docking indicates that the sugar moiety may not effectively interact with the active sites of the targets. Structure-based characteristics confer the multifunctional properties of Del and its glycosides. Because of their health-promoting effects, Del and its glycosides are promising and have been developed as potential pharmaceuticals. However, more investigation on the underlying mechanisms of Del and its glycosides in mediating cellular processes with high specificity are still needed. The research progression of Del and its glycosides over the last 10 years is comprehensively reviewed in this article.


Assuntos
Antocianinas/farmacologia , Glicosídeos/farmacologia , Animais , Antocianinas/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Glicosídeos/química , Humanos , Estrutura Molecular
6.
APMIS ; 127(12): 764-778, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31512767

RESUMO

Pathogen resistance to conventional antibiotics has become a serious clinical and public health problem, making the development of an alternative mean a very urgent issue. Recently, biosynthesis of silver nanoparticles (AgNPs) was successfully accomplished in the presence of Eucalyptus citriodora leaf extract as a reducing agent. In this study, the antimicrobial mechanisms of AgNPs against important hospital-acquired pathogens, including Gram-positive, Gram-negative bacteria, and fungi were further assessed. The results indicated that AgNPs could enhance a broad antimicrobial spectrum against drug-resistant organisms, with a range of minimum inhibitory concentration from 0.02 to 0.36 µg/mL. Time-kill assay showed that AgNPs produced bactericidal effects on the microorganisms. AgNPs could significantly reduce biofilm production in pathogens without affecting growth of the pathogens (p < 0.05). AgNPs inhibited cell viability and biofilm formation in a dose-dependent manner. Cell membrane damage in microorganisms resulting from effects of AgNPs was observed. A significant increase in per cent uptake of crystal violet was observed in all isolates treated with AgNPs when compared with the control (p < 0.05). Upon treatment with AgNPs, the surface charge of the reference strains and clinical isolates of pathogens moved towards neutral. The alteration of surface potential after exposure to AgNPs could contribute to membrane disruption and cell viability. Scanning electron microscopy further confirmed morphological cell changes and disrupted the cell membrane. Increasing resistance to AgNPs was not induced by stepwise isolation of the bacteria after 45 passages on Luria-Bertani agar supplemented with AgNPs. Furthermore, AgNPs was not toxic to red blood cells.


Assuntos
Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Eucalyptus/química , Fungos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Prata/farmacologia , Anti-Infecciosos/química , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Permeabilidade da Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Folhas de Planta/química , Prata/química
7.
Shanghai Kou Qiang Yi Xue ; 28(3): 246-250, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31489410

RESUMO

PURPOSE: To compare the antimicrobial effect of different irrigations on Enterococcus faecalis biofilms in extracted teeth and evaluate the antimicrobial activity of irrigating solutions residual against E. faecalis biofilms formation, in order to provide a better strategy for clinician. METHODS: Extracted human premolar teeth with single root canal were clearly autoclaved. These teeth were contaminated with E. faecalis(ATCC33186) and incubated for 60 days. The samples were randomly assigned to 4 experimental groups. During biomechanical instrumentation, the root canal was irrigated with different irrigating agents. The bacteria samples were collected with sterile paper points before and after instrumentation to F2. Then, samples that had been instrumented and autoclaved again were randomly divided into 2 groups treated with normal saline and 1%NaOCl for 30 min. E. faecalis was used to contaminate these root canals. The bacteria samples were collected with sterile paper points after 2, 6, 24, 48 h. SPSS19.0 software package was used for statistical analysis. RESULTS: Group using 1% NaOCI with ultrasound devices was significantly more effective than NS alone groups. 1% NaOCI groups showed a better residual activity than NS group. CONCLUSIONS: NaOCl is still the most important irrigating solutions, and it could be a better choice after biomechanical instrumentation, because of its long time substantivity achieves residual antimicrobial activity. Ultrasound devices is recommended to coordinate with irrigation.


Assuntos
Anti-Infecciosos , Cavidade Pulpar , Enterococcus faecalis , Irrigantes do Canal Radicular , Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Enterococcus faecalis/efeitos dos fármacos , Humanos , Irrigantes do Canal Radicular/farmacologia , Hipoclorito de Sódio
8.
J Agric Food Chem ; 67(39): 10880-10890, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31508956

RESUMO

A sustainable biomass-based nanocomposite hydrogel was formulated, characterized, and applied for curcumin delivery. Phytosynthesized zinc oxide nanoparticles (ZnO NPs) employing musk melon (Cucumis melo) seed extract was embedded in the hydrogel matrices and cross-linked using Dialdehyde cellulose prepared from sugarcane (Saccharum officinarum) bagasse (SCB). Nanoparticle incorporation enhanced the hydrogel's swelling degree to 4048% at pH 4.0. Also, an improved tensile strength of 14.1 ± 0.32 MPa was exhibited by the nanocomposite hydrogel compared to 9.79 ± 0.76 MPa for the pure chitosan cellulose hydrogel. A curcumin loading efficiency of 89.68% with around 30% increased loading was exhibited for the nanocomposite hydrogel. A Fickian diffusion-controlled curcumin release mechanism with maximum release at pH 7.4 was obtained. The synergistic effect on the antimicrobial activity was exhibited against Staphylococcus aureus and Trichophyton rubrum. The in vitro cytotoxicity studies employing L929 cells and A431 cells demonstrated good biocompatibility and enhanced anticancer activity of the curcumin-loaded green nanocomposite hydrogel compared to pure curcumin.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Curcumina/química , Curcumina/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Celulose/química , Quitosana/química , Cucumis melo/química , Portadores de Fármacos/química , Hidrogéis/química , Nanocompostos/química , Nanopartículas/química , Sementes/química , Staphylococcus aureus/efeitos dos fármacos , Trichophyton/efeitos dos fármacos , Trichophyton/crescimento & desenvolvimento , Óxido de Zinco/química
9.
Pestic Biochem Physiol ; 158: 185-200, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31378356

RESUMO

The present work describes the antimicrobial action of 25 monoterpenes (six hydrocarbons, five ketones, two aldehydes, six alcohols and six acetate analogues) against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus and antifungal activity against Aspergillus flavus. The antibacterial activity was evaluated by broth microdilution technique as a minimum inhibitory concentration (MIC) and the antifungal activity was performed by mycelia radial growth technique as the effective concentration causing 50% inhibition of the mycelial growth (EC50). The results showed that thymol and α-terpineol were the most potent against E. coli (MIC = 45 and 55 mg/L, respectively) and S. aureus (MIC = 135 and 225 mg/L, respectively). The results also showed that thymol displayed the maximum antifungal action against A. flavus with EC50 20 mg/L. Furthermore, the antioxidant activity was determined using N,N-dimethyl-1,4-phenylenediamine (DMPD) and the results showed that geraniol were the most potent compound (IC50 = 19 mg/L). Molecular docking studies indicated that the compounds displayed different binding interactions with the amino acid residues at the catalytic sites of N5-carboxyaminoimidazole synthetase and oxysterol binding protein Osh4 enzymes. Non-covalent interactions including van der Waals, hydrogen bonding as well as hydrophobic were observed between the compounds and the enzymes. A significant relationship was found between the docking score and the biological activity of the tested monoterpenes compared to the ceftriaxone and carbendazim as standard bactericide and fungicide, respectively. In silico ADMET properties were also performed and displayed potential for the development of promising antimicrobial agents. For these reasons, these compounds may be considered as potential ecofriendly alternatives in food preservation to delay or prevent the microbial infection and prolong the shelf life of food products.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Monoterpenos/metabolismo , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Infecciosos/química , Cicloexenos/química , Cicloexenos/farmacologia , Escherichia coli/efeitos dos fármacos , Hidrocarbonetos/química , Hidrocarbonetos/farmacologia , Testes de Sensibilidade Microbiana , Monoterpenos/química , Monoterpenos/farmacologia , Staphylococcus aureus/efeitos dos fármacos
10.
Mikrobiyol Bul ; 53(3): 254-261, 2019 Jul.
Artigo em Turco | MEDLINE | ID: mdl-31414627

RESUMO

Infections with multidrug resistant gram-negative bacteria is a growing problem especially in health care settings. Colistin is one of the last resort antibiotics for such infections in which treatment options are limited. Increasing resistance to colistin is a global problem. Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) study groups have recommended the ISO-standard broth microdilution method (20776-1) as the reference method for the determination of colistin susceptibility. Since the broth microdilution method is not a practical method, it is rarely used in routine clinical microbiology laboratories, yet simple and accurate phenotypic detection methods for the determination of colistin resistance in routine microbiology laboratories are not precisely defined. The aim of this study was to evaluate BD Phoenix100 (Becton Dickinson, USA) system and colistin broth disk elution method for the detection of in vitro activity of colistin against gram-negative bacteria. A total of 419 gram-negative bacteria, including 199 Klebsiella pneumoniae, 163 Acinetobacter baumannii, 34 Escherichia coli, 20 Enterobacter spp., and three Citrobacter spp. isolates which were isolated from various clinical samples in our hospital between 2016-2018 were tested. The broth microdilution method was used as the reference method applying ISO-standard broth microdilution methods (20776-1) and CLSI/EUCAST recommendations. For colistin broth disk elution method, final concentrations of 0 (growth control), 1, 2 and 4 µg/ml were obtained by adding 10 µg colistin disks to four tubes containing 10 ml cation-adjusted Mueller Hinton broth per isolate. After incubation at room temperature for 30 minutes, 50 µl of standardized inoculum suspensions were added to the tubes. Colistin minimum inhibitor concentration (MIC) values were read visually after 16-20 hours of incubation at 35°C in ambient air. Manufacturer's recommendations were followed for BD Phoenix100 system. The categorical agreement between the reference broth microdilution method and the colistin broth disk elution method was 99.3%, very major error and major error rates were 0.2% and 0.5%, respectively. For BD Phoenix100 system, the categorical agreement was 95%, with a very major error rate of 5%. Our results showed that colistin broth disc elution method worked well compared to the reference broth microdilution method. The BD Phoenix100 system, with a high very major error rate, does not reliably distinguish colistin-resistant and colistin-susceptible strains.


Assuntos
Anti-Infecciosos , Colistina , Bactérias Gram-Negativas , Testes de Sensibilidade Microbiana , Anti-Infecciosos/farmacologia , Colistina/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Testes de Sensibilidade Microbiana/instrumentação , Testes de Sensibilidade Microbiana/métodos
11.
Int J Nanomedicine ; 14: 5051-5060, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371946

RESUMO

Background: Chronic cutaneous wounds represent a major issue in medical care and are often prone to infections. Purpose: The aim of this study was the design of a clay mineral-drug nanocomposite based on montmorillonite and norfloxacin (NF, antimicrobial drug) as a powder for cutaneous application, to enhance wound healing in infected skin lesions. Methods: The nanocomposite has been prepared by means of an intercalation solution procedure. Adsorption isotherm, solid-state characterization of the nanocomposite, drug loading capacity and its release have been performed. Moreover, cytocompatibility, in vitro fibroblast proliferation and antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus were assessed. Results: The clay drug adsorption isotherm demonstrates that the mechanism of NF intercalation into montmorillonite galleries is the adsorption as one single process, due to the charge-charge interaction between protonated NF and negatively charged montmorillonite edges in the interlayer space. Nanocomposite is biocompatible and it is characterized by antimicrobial activity greater than the free drug: this is due to its nanostructure and controlled drug release properties. Conclusion: Considering the results obtained, NF-montmorillonite nanocomposite seems a promising tool to treat infected skin lesions or skin wounds prone to infection, as chronic ulcers (diabetic foot, venous leg ulcers) and burns.


Assuntos
Bentonita/química , Nanocompostos/química , Norfloxacino/farmacologia , Norfloxacino/uso terapêutico , Cicatrização/efeitos dos fármacos , Infecção dos Ferimentos/tratamento farmacológico , Adsorção , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Disponibilidade Biológica , Liberação Controlada de Fármacos , Humanos , Masculino , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Pseudomonas aeruginosa/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Temperatura Ambiente , Infecção dos Ferimentos/microbiologia , Difração de Raios X
12.
Microbiol Res ; 228: 126301, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31422232

RESUMO

The in vitro inhibition of quorum sensing signal, xanthan gum secretion, biofilm formation in different Xanthomonas pathovars and biological control of bacterial blight of rice by the two bioactive extrolites produced by Pseudomonas aeruginosa strain CGK-KS-1 were explored. These extrolites were extracted from Diaion HP-20 resin with methanol and purified by preparative-thin layer chromatography. Further, spectroscopic structural elucidation revealed the tentative identity of these extrolites to be (R,3E,5E,9Z,11E)-13-((3S,5R)-5-acetyl-2,6-dimethylheptan-3-yl)-10-hydroxy-4-methyl-1,8-diazabicyclo[9.3.1]pentadeca-3,5,9,11(15),13-pentaen-2-one and (R,3E,5E,8E,11E)-13-((3S,5R)-5-acetyl-2,6-dimethylheptan-3-yl)-4-methyl-1,8-diazabicyclo[9.3.1]pentadeca-3,5,8,11(15),13-pentaene-2,10-dione, named as Chumacin-1 and Chumacin-2, respectively. Antimicrobial assay showed Chumacin-1 and Chumacin-2 exhibited a strong in vitro growth inhibition against various Xanthomonas pathovars. Quorum sensing overlay assay using a reporter strain Chromobacterium violaceum strain CV026 showed that Chumacin-1 and Chumacin-2 inhibited quorum sensing signaling. The mechanistic studies revealed that these extrolites inhibited the production of quorum sensing signaling factor, cis-11-methyl-2-dodecenoic acid; suppressed the xanthan gum secretion and also inhibited the biofilms formed by various Xanthomonas pathovars. Both Chumacin-1 and Chumacin-2 showed ROS generation in the test Xanthomonas strains, resulting in in vitro cell membrane damage was revealed through CSLM and FE-SEM micrographs. Further, greenhouse experiments using Samba Mashuri (BPT-5204) revealed that seed treatment with Chumacin-1 and Chumacin-2 along with foliar spray groups showed up to ˜80% reduction in bacterial blight disease in rice. To the best of our knowledge, this is the first report on new quorum sensing inhibitors, Chumacin-1 and Chumacin-2 produced by Pseudomonas aeruginosa strain CGK-KS-1 exhibiting DSF inhibition activity in Xanthomonas oryzae pv. oryzae.


Assuntos
Agentes de Controle Biológico/isolamento & purificação , Agentes de Controle Biológico/farmacologia , Oryza/microbiologia , Doenças das Plantas/prevenção & controle , Pseudomonas aeruginosa/metabolismo , Percepção de Quorum/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Xanthomonas/efeitos dos fármacos , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Agentes de Controle Biológico/química , Chromobacterium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Doenças das Plantas/microbiologia , Polissacarídeos Bacterianos/metabolismo , Poliestirenos , Xanthomonas/metabolismo
13.
Epidemiol Mikrobiol Imunol ; 68(2): 65-70, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31398978

RESUMO

BACKGROUNDS: Snails (Gastropoda) have a mechanism for the production of a significant amount of slime and substances contained therein they use to protect themselves against bacterial or fungal pathogens. These active substances are involved in both humoral and cellular immune responses of the gastropods. The antibacterial or antifungal effect of the humoral immune component of slime lies in cytotoxic and haemagglutination activity against potential microbial pathogens. The activity of antibacterial agents present in Achatina reticulata slime against bacterial strains of Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa was tested. MATERIAL AND METHODS: A total of five samples of slime from laboratory reared Achatina reticulata were tested. To eliminate potential microbial contamination, slime samples were sterilized by UV radiation. To screen slime samples for antibacterial activity, the simple diffusion method on Mueller-Hinton agar was used. Samples diluted in guaiacol glycerol ether were used in the testing. RESULTS: The results show that the biologically active substances present in Achatina reticulata slime have an antimicrobial activity which is almost commensurate with that of the conventional antibiotics used to treat bacterial infections. The results of the determination of the antimicrobial effects of Achatina reticulata slime also highlighted viridation (partial hemolysis of erythrocytes after 24 hours of slime cultivation exposed to UV light for 60 minutes on Columbia blood agar. CONCLUSIONS: The results of the antimicrobial activity testing of selected Achatina reticulata slime samples show that the gastropod slime contains biologically active substances with a relatively significant antimicrobial activity.


Assuntos
Anti-Infecciosos , Bactérias , Gastrópodes , Animais , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Gastrópodes/microbiologia , Testes de Sensibilidade Microbiana , Muco/microbiologia
14.
Food Chem ; 298: 125098, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31276942

RESUMO

This work aimed to optimize an aqueous extract rich in phenolic compounds and potential functional properties made of Ilex paraguariensis, Melissa officinalis, and Cymbopogon citratus. The lyophilized extract was used for the development of an ice cream. Total phenolics, FRAP, DPPH, Folin-Ciocalteu's reducing capacity, and total reducing capacity of different combinations of herbal extracts were tested and modeled using response surface methodology. Simultaneous optimisation was employed to maximize the bioactive compounds in the extract and the lyophilized optimum combination was added to ice cream. The lyophilized extract contained quercetin-3-rutinoside, hesperidin, isoquercetin, caffeic acid, and 5,7-dihydroxyflavone. The optimised extract, which showed antihypertensive, antidiabetic, and antioxidant activity using in vitro protocols, increased total phenolics and antioxidant activity in comparison to the control ice cream. The ice cream presented a sensory acceptance index of 83%. After 72 days of storage (-18 °C), total phenolics and antioxidant activity significantly decreased.


Assuntos
Indústria de Processamento de Alimentos/métodos , Sorvetes , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Adolescente , Adulto , Anti-Infecciosos/farmacologia , Anti-Hipertensivos/química , Anti-Hipertensivos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Linhagem Celular , Cymbopogon/química , Feminino , Flavonoides/análise , Flavonoides/química , Armazenamento de Alimentos , Humanos , Sorvetes/análise , Ilex paraguariensis/química , Masculino , Melissa/química , Pessoa de Meia-Idade , Oligossacarídeos/química , Fenóis/química , Paladar
15.
Int J Nanomedicine ; 14: 4613-4624, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31308651

RESUMO

Background: Bacterial infection is a common and serious complication in orthopedic implants following traumatic injury, which is often associated with extensive soft tissue damage and contaminated wounds. Multidrug-resistant bacteria have been found in these infected wounds, especially in patients who have multi trauma and prolonged stay in intensive care units.Purpose: The objective of this study was to develop a coating on orthopedic implants that is effective against drug-resistant bacteria. Methods and results: We applied nanoparticles (30-70nm) of the trace element selenium (Se) as a coating through surface-induced nucleation-deposition on titanium implants and investigated the antimicrobial activity against drug resistant bacteria including Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-resistant Staphylococcus epidermidis (MRSE) in vitro and in an infected femur model in rats.The nanoparticles were shown in vitro to have antimicrobial activity at concentrations as low as 0.5ppm. The nanoparticle coatings strongly inhibited biofilm formation on the implants and reduced the number of viable bacteria in the surrounding tissue following inoculation of implants with biofilm forming doses of bacteria. Conclusion: This study shows a proof of concept for a selenium nanoparticle coatings as a potential anti-infective barrier for orthopedic medical devices in the setting of contamination with multi-resistant bacteria. It also represents one of the few (if only) in vivo assessment of selenium nanoparticle coatings on reducing antibiotic-resistant orthopedic implant infections.


Assuntos
Anti-Infecciosos/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Nanopartículas/química , Ortopedia , Próteses e Implantes , Selênio/farmacologia , Staphylococcus epidermidis/efeitos dos fármacos , Animais , Biofilmes/efeitos dos fármacos , Placas Ósseas , Parafusos Ósseos , Células Cultivadas , Contagem de Colônia Microbiana , Humanos , Masculino , Nanopartículas/ultraestrutura , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Ratos Sprague-Dawley , Titânio/farmacologia
16.
Food Chem ; 298: 125079, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260959

RESUMO

Citral-in-water emulsions were prepared with two different essential oil concentrations of 2.5 and 5.0% (w/w), then spray-dried in the presence of the same amount of maltodextrins (20%). The microcapsules were prepared with two different emulsifier compositions: monolayer microcapsules (ML) stabilized by sodium caseinate alone and layer-by-layer microcapsules (LBL) stabilized by sodium caseinate and pectin. The encapsulation efficiency was higher for LBL microcapsules (e.g. 99.6 ±â€¯0.4% for 2.5% citral) than that for ML ones (e.g. 78.6 ±â€¯0.6% for 2.5% citral) which confirm that the additional pectin layer was able to protect citral during the spray-drying process whatever citral concentration. Furthermore, our results showed that the antibacterial activity of the obtained microcapsules significantly depends on both citral concentration and interfacial membrane composition. The presence of two layers surrounding the citral droplets may result in a progressive and controlled release of the encapsulated citral.


Assuntos
Emulsões/química , Monoterpenos/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Cápsulas/química , Caseínas/química , Dessecação , Listeria/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Tamanho da Partícula , Pectinas/química , Polissacarídeos/química , Staphylococcus aureus/efeitos dos fármacos
17.
J Microbiol Biotechnol ; 29(7): 1144-1154, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31288301

RESUMO

There have been several studies regarding lichen-associated bacteria obtained from diverse environments. Our screening process identified 49 bacterial species in two lichens from the Himalayas: 17 species of Actinobacteria, 19 species of Firmicutes, and 13 species of Proteobacteria. We discovered five types of strong antimicrobial agent-producing bacteria. Although some strains exhibited weak antimicrobial activity, NP088, NP131, NP132, NP134, and NP160 exhibited strong antimicrobial activity against all multidrug-resistant strains. Polyketide synthase (PKS) fingerprinting revealed results for 69 of 148 strains; these had similar genes, such as fatty acid-related PKS, adenylation domain genes, PfaA, and PksD. Although the association between antimicrobial activity and the PKS fingerprinting results is poorly resolved, NP160 had six types of PKS fingerprinting genes, as well as strong antimicrobial activity. Therefore, we sequenced the draft genome of strain NP160, and predicted its secondary metabolism using antiSMASH version 4.2. NP160 had 46 clusters and was predicted to produce similar secondary metabolites with similarities of 5-100%. Although NP160 had 100% similarity with the alkylresorcinol biosynthetic gene cluster, our results showed low similarity with existing members of this biosynthetic gene cluster, and most have not yet been revealed. In conclusion, we expect that lichen-associated bacteria from the Himalayas can produce new secondary metabolites, and we found several secondary metabolite-related biosynthetic gene clusters to support this hypothesis.


Assuntos
Anti-Infecciosos/metabolismo , Genoma Bacteriano/genética , Líquens/microbiologia , Streptomyces/genética , Streptomyces/metabolismo , Anti-Infecciosos/farmacologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Sequência de Bases , Impressões Digitais de DNA , DNA Bacteriano/genética , Testes de Sensibilidade Microbiana , Família Multigênica , Filogenia , Policetídeo Sintases/genética , RNA Ribossômico 16S/genética , Metabolismo Secundário/genética , Análise de Sequência de DNA
18.
J Microbiol Biotechnol ; 29(7): 1009-1013, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31288302

RESUMO

Polymeric nanoparticles are widely used for drug delivery due to their biodegradability property. Among the wide array of polymers, chitosan has received growing interest among researchers. It was widely used as a vehicle in polymeric nanoparticles for drug targeting. This review explored the current research on the antimicrobial activity of chitosan nanoparticles (ChNP) and the impact on the clinical applications. The antimicrobial activities of ChNP were widely reported against bacteria, fungi, yeasts and algae, in both in vivo and in vitro studies. For pharmaceutical applications, ChNP were used as antimicrobial coating for promoting wound healing, preventing infections and combating the rise of infectious disease. Besides, ChNP also exhibited significant inhibitory on foodborne microorganisms, particularly on fruits and vegetables. It is noteworthy that ChNP can be also applied to deliver antimicrobial drugs, which further enhance the efficiency and stability of the antimicrobial agent. The present review addresses the potential antimicrobial applications of ChNP from these few aspects.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Quitosana/química , Portadores de Fármacos/química , Fungos/efeitos dos fármacos , Nanopartículas/química , Materiais Biocompatíveis , Sistemas de Liberação de Medicamentos , Humanos , Nanotecnologia , Polímeros/química
19.
BMC Infect Dis ; 19(1): 603, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291896

RESUMO

BACKGROUND: This study aims to investigate the pathogen distribution and drug resistance in patients with acute cerebral infarction complicated with diabetes mellitus and nosocomial pulmonary infection. METHODS: From August 2015 to December 2017, 172 pathogenic bacterial strains from patients with acute cerebral infarction complicated with diabetes mellitus and nosocomial pulmonary infection in our hospital were identified, and the drug sensitivity was analyzed. RESULTS: Among these 172 strains of pathogenic bacteria, gram negative bacteria was the main cause of pulmonary infection in hospitalized patients with acute cerebral infarction, accounting for 75.6% of all pathogens. Furthermore, 80% of diabetic patients with cerebral infarction had lung infection induced by gram negative bacteria, which was significantly higher than that in non-diabetic patients (72.2%). Moreover, the drug resistance rate in the diabetic group (68.3%) was significantly higher than that in the non-diabetic group (54.3%). Gram positive bacteria accounted for 19.1% of all pathogenic bacteria. The infection rate of gram-positive bacteria in diabetic patients with cerebral infarction was 14.7%, which was lower than that in the non-diabetic group (22.6%). The drug-resistance rate was higher in the diabetic group (45.5%) than in the non-diabetic group (28.2%). Furthermore, the fungal infection rate in patients with lung infection in these two groups was 5.3 and 5.2%, respectively, and fungi presented with high sensitivity to commonly used antifungal agents. CONCLUSION: In patients with acute cerebral infarction complicated with diabetes mellitus and nosocomial pulmonary infection, the majority of pathogens are multidrug-resistant gram negative bacilli. Pathogen culture should be conducted as soon as possible before using antibiotics, and antimicrobial agents should be reasonably used according to drug sensitivity test results.


Assuntos
Infarto Cerebral/complicações , Infecção Hospitalar/microbiologia , Complicações do Diabetes/microbiologia , Resistência Microbiana a Medicamentos , Pneumonia/microbiologia , Doença Aguda , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Infarto Cerebral/tratamento farmacológico , Infarto Cerebral/microbiologia , Infecção Hospitalar/tratamento farmacológico , Complicações do Diabetes/tratamento farmacológico , Feminino , Fungos/classificação , Fungos/efeitos dos fármacos , Fungos/isolamento & purificação , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pneumonia/tratamento farmacológico
20.
J Food Sci ; 84(8): 2190-2198, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31313308

RESUMO

A new microbial decontamination system combining washing with a natural antimicrobial solution and coating with a carnauba wax (CW)-based antimicrobial coating was developed and its effects on mandarin storability were investigated. Mandarins were washed with an antimicrobial solution and/or coated with grapefruit seed extract-CW (GSE/CW). Values for the disease incidence of Penicillium digitatum in untreated mandarins; mandarins coated with GSE/CW without washing; and mandarins coated with GSE/CW after washing with a fumaric acid (FA) solution of slightly acidic electrolyzed water, a highly activated calcium oxide (CaO) aqueous solution, or CaO solution followed by FA solution were 96.0, 70.0, 78.8, 50.0, and 72.2%, respectively. GSE/CW coating after CaO washing was most effective in inhibiting P. digitatum growth during storage at 25 °C. Compared to untreated samples, GSE/CW coating alone or after CaO washing retained CO2 generation, firmness, and total polyphenol content of mandarins at 25 °C. Such treatments also effectively maintained mandarin pH, ascorbic acid concentration, and antioxidant capacity at both 4 and 25 °C. Moreover, GSE/CW coating after CaO washing more effectively inhibited P. digitatum growth at 25 °C and maintained ascorbic acid concentration and antioxidant capacity at 4 and 25 °C than GSE/CW coating alone. The microbial decontamination system integrating CaO washing and GSE/CW coating demonstrates potential for improving mandarin storability by inhibiting P. digitatum growth and improving the preservation of quality properties and sensory characteristics. PRACTICAL APPLICATION: This is the first study to develop a microbial decontamination system involving both washing with a natural antimicrobial solution and carnauba wax coating containing grapefruit seed extract to improve the storability of fruits. This system demonstrated a primary effect of inhibiting fungi that cause mandarin surface decay at 25 °C via the highly activated calcium oxide wash and secondary effects of delaying quality degradation and inhibiting fungal growth by the action of the antimicrobial coating. These effects led to improvements in mandarin storability, along with enhanced visual appeal while not affecting taste, flavor, or texture.


Assuntos
Anti-Infecciosos/farmacologia , Compostos de Cálcio/farmacologia , Citrus/microbiologia , Descontaminação/métodos , Conservação de Alimentos/métodos , Frutas/microbiologia , Óxidos/farmacologia , Citrus/química , Frutas/química , Penicillium/efeitos dos fármacos , Penicillium/crescimento & desenvolvimento , Água/análise , Ceras/análise
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