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1.
Int J Food Microbiol ; 335: 108883, 2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-32956955

RESUMO

Kpkt is a yeast killer toxin, naturally produced by Tetrapisispora phaffii, with possible applications in winemaking due to its antimicrobial activity on wine-related yeasts including Kloeckera/Hanseniaspora, Saccharomycodes and Zygosaccharomyces. Here, Kpkt coding gene was expressed in Komagataella phaffii (formerly Pichia pastoris) and the bioreactor production of the recombinant toxin (rKpkt) was obtained. Moreover, to produce a ready-to-use preparation of rKpkt, the cell-free supernatant of the K. phaffii recombinant killer clone was 80-fold concentrated and lyophilized. The resulting preparation could be easily solubilized in sterile distilled water and maintained its killer activity for up to six months at 4 °C. When applied to grape must, it exerted an extensive killer activity on wild wine-related yeasts while proving compatible with the fermentative activity of actively growing Saccharomyces cerevisiae starter strains. Moreover, it displayed a strong microbicidal effect on a variety of bacterial species including lactic acid bacteria and food-borne pathogens. On the contrary it showed no lethal effect on filamentous fungi and on Ceratitis capitata and Musca domestica, two insect species that may serve as non-mammalian model for biomedical research. Based on these results, bioreactor production and lyophilization represent an interesting option for the exploitation of this killer toxin that, due to its spectrum of action, may find application in the control of microbial contaminations in the wine and food industries.


Assuntos
Fatores Matadores de Levedura/farmacologia , Vinho/microbiologia , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Reatores Biológicos/microbiologia , Fermentação , Indústria Alimentícia , Microbiologia de Alimentos , Liofilização , Fatores Matadores de Levedura/biossíntese , Viabilidade Microbiana , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/farmacologia , Leveduras/efeitos dos fármacos
2.
PLoS One ; 15(7): e0234964, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614844

RESUMO

In this study, a facile, ecological and economical green method is described for the fabrication of iron (Fe), copper (Cu) and silver (Ag) nanoparticles (NPs) from the extract of Syzygium cumini leaves. The obtained metal NPs were categorized using UV/Vis, SEM, TEM, FTIR and EDX-ray spectroscopy techniques. The Fe-, Cu- and Ag-NPs were crystalline, spherical and size ranged from 40-52, 28-35 and 11-19 nm, respectively. The Ag-NPs showed excellent antimicrobial activities against methicillin- and vancomycin-resistance Staphylococcus aureus bacterial strains and Aspergillus flavus and A. parasiticus fungal species. Furthermore, the aflatoxins (AFs) production was also significantly inhibited when compared with the Fe- and Cu-NPs. In contrast, the adsorption results of NPs with aflatoxin B1 (AFB1) were observed as following order Fe->Cu->Ag-NPs. The Langmuir isotherm model well described the equilibrium data by the sorption capacity of Fe-NPs (105.3 ng mg-1), Cu-NPs (88.5 ng mg-1) and Ag-NPs (81.7 ng mg-1). The adsorption was found feasible, endothermic and follow the pseudo-second order kinetic model as revealed by the thermodynamic and kinetic studies. The present findings suggests that the green synthesis of metal NPs is a simple, sustainable, non-toxic, economical and energy-effective as compared to the others conventional approaches. In addition, synthesized metal NPs might be a promising AFs adsorbent for the detoxification of AFB1 in human and animal food/feed.


Assuntos
Aflatoxina B1/isolamento & purificação , Anti-Infecciosos/metabolismo , Biotecnologia/métodos , Cobre , Química Verde/métodos , Ferro , Nanopartículas Metálicas , Extratos Vegetais/metabolismo , Folhas de Planta/metabolismo , Prata , Desintoxicação por Sorção , Syzygium/metabolismo , Adsorção , Anti-Infecciosos/farmacologia , Aspergillus/efeitos dos fármacos , Aspergillus flavus/efeitos dos fármacos , Técnicas de Química Analítica , Cobre/administração & dosagem , Cobre/farmacologia , Resistência Microbiana a Medicamentos , Ferro/administração & dosagem , Ferro/farmacologia , Cinética , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Oxirredução , Prata/administração & dosagem , Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Termodinâmica , Vancomicina/farmacologia
3.
Emerg Top Life Sci ; 4(1): 59-76, 2020 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-32558901

RESUMO

Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management.


Assuntos
Anti-Infecciosos/metabolismo , Abelhas/imunologia , Abelhas/fisiologia , Parasitos/microbiologia , Viroses/imunologia , Animais , Comportamento Animal , Biodiversidade , Dieta , Ecossistema , Interações Hospedeiro-Parasita , Imunidade , Microbiota , Praguicidas/metabolismo
4.
Int J Oral Sci ; 12(1): 13, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32350241

RESUMO

Efforts to control inflammation and achieve better tissue repair in the treatment of periodontitis have been ongoing for years. Human ß-defensin 3, a broad-spectrum antimicrobial peptide has been proven to have a variety of biological functions in periodontitis; however, relatively few reports have addressed the effects of human periodontal ligament cells (hPDLCs) on osteogenic differentiation. In this study, we evaluated the osteogenic effects of hPDLCs with an adenoviral vector encoding human ß-defensin 3 in an inflammatory microenvironment. Then human ß-defensin 3 gene-modified rat periodontal ligament cells were transplanted into rats with experimental periodontitis to observe their effects on periodontal bone repair. We found that the human ß-defensin 3 gene-modified hPDLCs presented with high levels of osteogenesis-related gene expression and calcium deposition. Furthermore, the p38 MAPK pathway was activated in this process. In vivo, human ß-defensin 3 gene-transfected rat PDLCs promoted bone repair in SD rats with periodontitis, and the p38 mitogen-activated protein kinase (MAPK) pathway might also have been involved. These findings demonstrate that human ß-defensin 3 accelerates osteogenesis and that human ß-defensin 3 gene modification may offer a potential approach to promote bone repair in patients with periodontitis.


Assuntos
Anti-Infecciosos/farmacologia , Osteogênese/efeitos dos fármacos , Ligamento Periodontal/metabolismo , Periodontite/tratamento farmacológico , beta-Defensinas/farmacologia , Animais , Anti-Infecciosos/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Ligamento Periodontal/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , beta-Defensinas/metabolismo
5.
Proc Natl Acad Sci U S A ; 117(22): 12444-12451, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32393619

RESUMO

Antibiotic resistance and viral diseases are rising around the world and are becoming major threats to global health, food security, and development. One measure that has been suggested to mitigate this crisis is the development of new antibiotics. Here, we provide a comprehensive evaluation of the phylogenetic and biogeographic patterns of antiinfective compounds from seed plants in one of the most species-rich regions on Earth and identify clades with naturally occurring substances potentially suitable for the development of new pharmaceutical compounds. Specifically, we combine taxonomic and phylogenetic data for >7,500 seed plant species from the flora of Java with >16,500 secondary metabolites and 6,255 georeferenced occurrence records to 1) identify clades in the phylogeny that are characterized by either an overrepresentation ("hot clades") or an underrepresentation ("cold clades") of antiinfective compounds and 2) assess the spatial patterns of plants with antiinfective compounds relative to total plant diversity across the region. Across the flora of Java, we identify 26 "hot clades" with plant species providing a high probability of finding antibiotic constituents. In addition, 24 "cold clades" constitute lineages with low numbers of reported activities but which have the potential to yield novel compounds. Spatial patterns of plant species and metabolite diversity are strongly correlated across Java, indicating that regions of highest species diversity afford the highest potential to discover novel natural products. Our results indicate that the combination of phylogenetic, spatial, and phytochemical information is a useful tool to guide the selection of taxa for efforts aimed at lead compound discovery.


Assuntos
Anti-Infecciosos/análise , Chumbo/análise , Filogenia , Plantas/química , Plantas/genética , Anti-Infecciosos/metabolismo , Biodiversidade , Chumbo/metabolismo , Plantas/classificação , Plantas/metabolismo
7.
Poult Sci ; 99(4): 1875-1887, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241467

RESUMO

The present study was undertaken to investigate the effect of aqueous Withania somnifera root (WSR) extract in broiler chicks experimentally infected with Escherichia coli O78 @ 107 CFU/0.5 ml intraperitoneally. Clinical signs and mortality due to colibacillosis observed in infected chicks were mild and lasted for short duration in WSR extract supplemented group as compared with the nonsupplemented group. A significant increase in serum alanine transaminase, aspartate transaminase, lactate dehydrogenase, and creatine phosphokinase activities and a decrease in total protein and albumin concentrations were observed in the infected groups, though these changes were of lower magnitude in WSR extract supplemented group. A significantly higher activity of oxidative blood parameters such as superoxide dismutase, catalase, glutathione reductase, and glutathione-S-transferase enzymes were noticed in WSR extract supplemented group. The WSR extract supplemented group revealed significantly higher E. coli-specific antibody titer and enhanced lymphocyte proliferation response as compared with the nonsupplemented group. The gross and histopathological lesions of colibacillosis were mild in the WSR extract-supplemented infected group as compared with the nonsupplemented infected group. Withania somnifera root extract supplementation produced 31.48 and 34.38% protection in the gross and histopathological lesions in E. coli infected chicks, respectively. It is concluded that supplementation of 20% WSR extract @ 20 ml/L of water caused a reduction in the severity, mortality, and recovery period of E. coli infection and enhanced the humoral and cellular immune responses suggesting its protective effect on limiting the pathology of E. coli infection in broiler chickens.


Assuntos
Anti-Infecciosos/metabolismo , Galinhas , Infecções por Escherichia coli/veterinária , Escherichia coli/fisiologia , Extratos Vegetais/metabolismo , Doenças das Aves Domésticas/tratamento farmacológico , Withania/química , Ração Animal/análise , Animais , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/química , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Raízes de Plantas/química , Doenças das Aves Domésticas/microbiologia , Distribuição Aleatória
8.
Biomed Res Int ; 2020: 8650957, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32190683

RESUMO

Paenibacillus polymyxa is a plant growth-promoting rhizobacterium that has immense potential to be used as an environmentally friendly replacement of chemical fertilizers and pesticides. In the present study, Paenibacillus polymyxa SK1 was isolated from bulbs of Lilium lancifolium. The isolated endophytic strain showed antifungal activities against important plant pathogens like Botryosphaeria dothidea, Fusarium oxysporum, Botrytis cinerea, and Fusarium fujikuroi. The highest percentage of growth inhibition, i.e., 66.67 ± 2.23%, was observed for SK1 against Botryosphaeria dothidea followed by 61.19 ± 3.12%, 60.71 ± 3.53%, and 55.54 ± 2.89% against Botrytis cinerea, Fusarium fujikuroi, and Fusarium oxysporum, respectively. The metabolite profiling of ethyl acetate fraction was assessed through the UHPLC-LTQ-IT-MS/MS analysis, and putative identification was done with the aid of the GNPS molecular networking workflow. A total of 29 compounds were putatively identified which included dipeptides, tripeptides, cyclopeptides (cyclo-(Leu-Leu), cyclo(Pro-Phe)), 2-heptyl-3-hydroxy 4-quinolone, 6-oxocativic acid, anhydrobrazilic acid, 1-(5-methoxy-1H-indol-3-yl)-2-piperidin-1-ylethane-1,2-dione, octadecenoic acid, pyochelin, 15-hydroxy-5Z,8Z,11Z, 13E-eicosatetraenoic acid, (Z)-7-[(2R,3S)-3-[(2Z,5E)-Undeca-2,5-dienyl]oxiran-2-yl]hept-5-enoic acid, arginylasparagine, cholic acid, sphinganine, elaidic acid, gossypin, L-carnosine, tetrodotoxin, and ursodiol. The high antifungal activity of SK1 might be attributed to the presence of these bioactive compounds. The isolated strain SK1 showed plant growth-promoting traits such as the production of organic acids, ACC deaminase, indole-3-acetic acid (IAA), siderophores, nitrogen fixation, and phosphate solubilization. IAA production was strongly correlated with the application of exogenous tryptophan concentrations in the medium. Furthermore, inoculation of SK1 enhanced plant growth of two Lilium varieties, Tresor and White Heaven, under greenhouse condition. In the light of these findings, the P. polymyxa SK1 may be utilized as a source of plant growth promotion and disease control in sustainable agriculture.


Assuntos
Ascomicetos/fisiologia , Fusarium/fisiologia , Lilium/microbiologia , Paenibacillus polymyxa/fisiologia , Doenças das Plantas/prevenção & controle , Anti-Infecciosos/metabolismo , Carbono-Carbono Liases/metabolismo , Ácidos Carboxílicos/metabolismo , Endófitos , Ácidos Indolacéticos/metabolismo , Lilium/crescimento & desenvolvimento , Fixação de Nitrogênio , Paenibacillus polymyxa/química , Paenibacillus polymyxa/classificação , Paenibacillus polymyxa/genética , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Sideróforos/metabolismo , Espectrometria de Massas em Tandem
9.
J Leukoc Biol ; 108(1): 377-396, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32202340

RESUMO

Neutrophils are the most abundant leukocytes in blood. From the circulation, they are quickly mobilized to sites of inflammation and/or infection. At the affected tissues, neutrophils display an impressive array of antimicrobial functions, including degranulation, production of reactive oxygen species (ROS), phagocytosis, and formation of neutrophil extracellular traps (NET). Because neutrophils are the first type of leukocytes to arrive at affected tissues and display potent microbicidal functions, they have been classically viewed as the first line of defense. In this view, neutrophils only destroy invading pathogens and then quietly die at the site of infection. However, in the last decade it has become increasingly evident that neutrophils are much more complex cells having not only effector functions in the innate immune response, but also the capacity of modulating the adaptive immune response, via direct interaction with, or by producing cytokines that affect dendritic cells and lymphocytes. In addition, neutrophil heterogeneity with clear different functional phenotypes has been recently described particularly in cancer and inflammation. This review provides an overview on the life of a neutrophil describing its beginnings, lifespan, and their principal functions in innate and adaptive immunity. Also, neutrophil heterogeneity and our current understanding of neutrophil contributions to health and disease are discussed.


Assuntos
Imunidade Adaptativa , Imunidade Inata/imunologia , Neutrófilos , Animais , Anti-Infecciosos/metabolismo , Adesão Celular , Homeostase , Humanos , Neutrófilos/imunologia
10.
PLoS One ; 15(3): e0230021, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32160226

RESUMO

Supplementing chicken feed with antibiotics can improve survival and prevent disease outbreaks. However, overuse of antibiotics may promote the development of antibiotic-resistant bacteria. Recently, antimicrobial peptides have been proposed as alternatives to antibiotics in animal husbandry. Here, we evaluate the effects of antimicrobial peptide, Epinephelus lanceolatus piscidin (EP), in Gallus gallus domesticus. The gene encoding EP was isolated, sequenced, codon-optimized and cloned into a Pichia pastoris recombinant protein expression system. The expressed recombinant EP (rEP) was then used as a dietary supplement for G. g. domesticus; overall health, growth performance and immunity were assessed. Supernatant from rEP-expressing yeast showed in vitro antimicrobial activity against Gram-positive and Gram-negative bacteria, according to an inhibition-zone diameter (mm) assay. Moreover, the antimicrobial peptide function of rEP was temperature independent. The fermentation broth yielded a spray-dried powder formulation containing 262.9 µg EP/g powder, and LC-MS/MS (tandem MS) analysis confirmed that rEP had a molecular weight of 4279 Da, as expected for the 34-amino acid peptide; the DNA sequence of the expression vector was also validated. We then evaluated rEP as a feed additive for G. g. domesticus. Treatment groups included control, basal diet and rEP at different doses (0.75, 1.5, 3.0, 6.0 and 12%). Compared to control, rEP supplementation increased G. g. domesticus weight gain, feed efficiency, IL-10 and IFN-γ production. Our results suggest that crude rEP could provide an alternative to traditional antibiotic feed additives for G. g. domesticus, serving to enhance growth and health of the animals.


Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Galinhas/imunologia , Sistema Imunitário/metabolismo , Perciformes/metabolismo , Sequência de Aminoácidos , Animais , Anti-Infecciosos/análise , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/análise , Peptídeos Catiônicos Antimicrobianos/classificação , Peptídeos Catiônicos Antimicrobianos/genética , Galinhas/crescimento & desenvolvimento , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Suplementos Nutricionais , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Sistema Imunitário/efeitos dos fármacos , Interferon gama/metabolismo , Interleucina-10/metabolismo , Filogenia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Alinhamento de Sequência , Espectrometria de Massas em Tandem , Temperatura
11.
Can J Microbiol ; 66(6): 401-412, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32160477

RESUMO

Fusarium wilt is a devastating soil-borne disease mainly caused by highly host-specific formae speciales of Fusarium spp. Antagonistic microorganisms play a very important role in Fusarium wilt control. Isolation of potential biocontrol strains has become increasingly important. Bacterial strain SEM-2 was isolated from the high-temperature stage of silkworm excrement composting. SEM-2 exhibited a considerable antagonistic effect against Fusarium graminearum mycelial growth and spore germination. The results of pot experiments suggested that SEM-2 has a better inhibitory effect on the early stage of disease occurrence. The green fluorescent protein labelled SEM-2 coated on the surface of tomato seeds colonised the roots of tomato plants in 15 days. Genome sequencing identified SEM-2 as a new strain of Bacillus subtilis, and genome annotation and analysis determined gene clusters related to the biosynthesis of antimicrobials, such as bacillaene, fengycin, bacillibactin, subtilosin A, surfactin, and bacilysin. Interestingly, liquid chromatography - quadrupole time-of-flight mass spectrometry revealed that metabolites in pathways associated with the synthesis of secondary metabolites and antibiotics were highly differentially expressed. These findings may help to explain the mode of action of B. subtilis SEM-2 against Fusarium spp.


Assuntos
Antibiose , Bacillus subtilis/fisiologia , Bombyx/microbiologia , Fusarium/crescimento & desenvolvimento , Genoma Bacteriano/genética , Lycopersicon esculentum/microbiologia , Doenças das Plantas/prevenção & controle , Animais , Anti-Infecciosos/metabolismo , Bacillus subtilis/química , Bacillus subtilis/genética , Bacillus subtilis/isolamento & purificação , Agentes de Controle Biológico , Cromatografia Líquida , Fezes/microbiologia , Espectrometria de Massas , Família Multigênica/genética , Doenças das Plantas/microbiologia , Sementes/microbiologia
12.
Life Sci ; 253: 117581, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32209424

RESUMO

AIMS: Cisplatin (CDDP) is an effective antineoplastic agent, however, its serious nephrotoxicity limits therapeutic use. Human growth hormone (hGH) has proved antioxidant and anti-inflammatory activities. The present study aimed to investigate the nephroprotective effects of hGH against CDDP-induced nephrotoxicity and the mechanisms underlying this nephroprotection. MAIN METHODS: Male albino rats injected with CDDP (7 mg/kg) and nephrotoxicity indices, oxidative stress and inflammatory biomarkers (high mobility group box protein-1 (HMGB-1), soluble epoxide hydrolase (sEH), and nuclear factor-kappa B (NF-κB)) were assessed. Also, insulin-like growth factor-1 (IGF-1) and Nuclear factor-erythroid-2 (Nrf2)/heme oxygenase-1 (HO-1) pathway were assessed. KEY FINDINGS: hGH (1 mg/kg) improved kidney function and antioxidant systems and showed intact renal tubular epithelium. Cisplatin upregulated the HMGB-1/NF-κB and downregulated Nrf2/HO-1 pathways which were reversed by hGH and aligned with increased renal IGF-1 expression. Also, IGF-1/sEH crosstalk might be involved in hGH nephroprotection. Moreover, hGH downregulated HSP70 and caspase-3 expressions. SIGNIFICANCE: these results concluded that hGH can attenuate the inflammation and oxidative stress attained by CDDP probably through inhibition of Nrf2/HO-1 pathway. We also suggested that Keap1/Nrf2-mediated upregulation of the antioxidant HO-1 might inhibit HMGB-1/NF-κB signaling and thus provide the principal protection mechanism offered by hGH against CDDP-induced kidney injury.


Assuntos
Lesão Renal Aguda/prevenção & controle , Cisplatino/efeitos adversos , Hormônio do Crescimento/metabolismo , Heme Oxigenase-1/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Lesão Renal Aguda/induzido quimicamente , Lesão Renal Aguda/patologia , Animais , Anti-Infecciosos/efeitos adversos , Anti-Infecciosos/metabolismo , Antineoplásicos/efeitos adversos , Antineoplásicos/metabolismo , Antioxidantes/efeitos adversos , Antioxidantes/farmacologia , Caspase 3/metabolismo , Cisplatino/metabolismo , Modelos Animais de Doenças , Epóxido Hidrolases/metabolismo , Hormônio do Crescimento/farmacologia , Proteínas HMGB/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Hormônio do Crescimento Humano , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Masculino , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Transdução de Sinais
13.
Sci Rep ; 10(1): 4104, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139731

RESUMO

Actinobacteria is a goldmine for the discovery of abundant secondary metabolites with diverse biological activities. This study explores antimicrobial biosynthetic potential and diversity of actinobacteria from Pobitora Wildlife Sanctuary and Kaziranga National Park of Assam, India, lying in the Indo-Burma mega-biodiversity hotspot. A total of 107 actinobacteria were isolated, of which 77 exhibited significant antagonistic activity. 24 isolates tested positive for at least one of the polyketide synthase type I, polyketide synthase type II or non-ribosomal peptide synthase genes within their genome. Their secondary metabolite pathway products were predicted to be involved in the production of ansamycin, benzoisochromanequinone, streptogramin using DoBISCUIT database. Molecular identification indicated that these actinobacteria predominantly belonged to genus Streptomyces, followed by Nocardia and Kribbella. 4 strains, viz. Streptomyces sp. PB-79 (GenBank accession no. KU901725; 1313 bp), Streptomyces sp. Kz-28 (GenBank accession no. KY000534; 1378 bp), Streptomyces sp. Kz-32 (GenBank accession no. KY000536; 1377 bp) and Streptomyces sp. Kz-67 (GenBank accession no. KY000540; 1383 bp) showed ~89.5% similarity to the nearest type strain in EzTaxon database and may be considered novel. Streptomyces sp. Kz-24 (GenBank accession no. KY000533; 1367 bp) showed only 96.2% sequence similarity to S. malaysiensis and exhibited minimum inhibitory concentration of 0.024 µg/mL against methicilin resistant Staphylococcus aureus ATCC 43300 and Candida albicans MTCC 227. This study establishes that actinobacteria isolated from the poorly explored Indo-Burma mega-biodiversity hotspot may be an extremely rich reservoir for production of biologically active compounds for human welfare.


Assuntos
Actinobacteria/metabolismo , Anti-Infecciosos/metabolismo , Florestas , Microbiologia do Solo , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Anti-Infecciosos/farmacologia , Biodiversidade , Índia , Testes de Sensibilidade Microbiana , Peptídeo Sintases/genética
14.
J Med Microbiol ; 69(3): 361-371, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32043956

RESUMO

Pseudomonas chlororaphis isolates have been studied intensively for their beneficial traits. P. chlororaphis species function as probiotics in plants and fish, offering plants protection against microbes, nematodes and insects. In this review, we discuss the classification of P. chlororaphis isolates within four subspecies; the shared traits include the production of coloured antimicrobial phenazines, high sequence identity between housekeeping genes and similar cellular fatty acid composition. The direct antimicrobial, insecticidal and nematocidal effects of P. chlororaphis isolates are correlated with known metabolites. Other metabolites prime the plants for stress tolerance and participate in microbial cell signalling events and biofilm formation among other things. Formulations of P. chlororaphis isolates and their metabolites are currently being commercialized for agricultural use.


Assuntos
Anti-Infecciosos/metabolismo , Biofilmes/crescimento & desenvolvimento , Fenazinas/metabolismo , Plantas/microbiologia , Probióticos , Pseudomonas chlororaphis/classificação , Acil-Butirolactonas/metabolismo , Agricultura , Antinematódeos/metabolismo , Cianeto de Hidrogênio/metabolismo , Inseticidas/metabolismo , Fenótipo , Plantas/imunologia , Pseudomonas chlororaphis/química , Pseudomonas chlororaphis/crescimento & desenvolvimento , Pseudomonas chlororaphis/fisiologia , Pirrolnitrina/metabolismo , Resorcinóis/metabolismo , Sideróforos/metabolismo , Compostos Orgânicos Voláteis/metabolismo
15.
Genes (Basel) ; 11(2)2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32024145

RESUMO

Antimicrobial peptides (AMPs) are evolutionarily ancient molecules that play an essential role in innate immunity across taxa from invertebrates to vertebrates. The evolution system of AMP system has not been well explained in the literature. In this study, we cloned and sequenced AMP transcriptomes of three frog species, namely Rana dybowskii, Rana amurensis, and Pelophylax nigromaculatus, which are partially sympatric in northeast Asia, but show different habitat preferences. We found that each species contained 7 to 14 families of AMPs and the diversity was higher in species with a large geographic range and greater habitat variation. All AMPs are phylogenetically related but not associated with the speciation process. Most AMP genes were under negative selection. We propose that the diversification and addition of novel functions and improvement of antimicrobial efficiency are facilitated by the expansion of family members and numbers. We also documented significant negative correlation of net charges and numbers of amino acid residues between the propiece and mature peptide segments. This supports the Net Charge Balance Hypothesis. We propose the Cut Point Sliding Hypothesis as a novel diversification mechanism to explain the correlation in lengths of the two segments.


Assuntos
Anti-Infecciosos/classificação , Peptídeos Catiônicos Antimicrobianos/classificação , Peptídeos Catiônicos Antimicrobianos/genética , Anuros/classificação , Evolução Molecular , Mutação , Sequência de Aminoácidos , Animais , Anti-Infecciosos/química , Anti-Infecciosos/metabolismo , Peptídeos Catiônicos Antimicrobianos/química , Anuros/genética , Ásia , Filogenia , Homologia de Sequência , Simpatria/genética , Transcriptoma
16.
Food Chem ; 317: 126389, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32097822

RESUMO

Glyceollins are a class of antimicrobial prenylated pterocarpans produced in soybean seedlings upon fungus elicitation. Priming with reactive oxygen species (ROS) prior to elicitation with Rhizopus oligosporus/oryzae (R) was investigated for its potential to enhance glyceollin production. ROS-priming prior to R-elicitation (ROS + R) increased glyceollin production (8.6 ± 0.9 µmol/g dry weight (DW)) more than 4-fold compared to elicitation without priming (1.9 ± 0.4 µmol/g DW). Furthermore, ROS-priming was superior to two physical primers which were used as benchmark primers, namely slicing (5.0 ± 0.6 µmol glyceollins/g DW) and sonication (4.8 ± 1.0 µmol glyceollins/g DW). Subsequently, the robustness of ROS + R was assessed by applying it to another soybean cultivar, where it also resulted in a significantly higher glyceollin content than R-elicitation without priming. ROS-priming prior to elicitation provides opportunities for improving the yield in large-scale production of natural antimicrobials due to the ease of application and the robustness of the effect across cultivars.


Assuntos
Anti-Infecciosos/metabolismo , Doenças das Plantas/imunologia , Pterocarpanos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Rhizopus/fisiologia , Soja/metabolismo , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Doenças das Plantas/microbiologia , Pterocarpanos/química , Pterocarpanos/farmacologia , Plântula/química , Plântula/metabolismo , Plântula/microbiologia , Soja/química , Soja/microbiologia
17.
Int J Mol Sci ; 21(2)2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31941098

RESUMO

Lysozymes are key antimicrobial peptides in the host innate immune system that protect against pathogen infection. In this study, the full-length cDNAs of two c-type lysozymes (gfLyz-C1 and gfLyz-C2) were cloned from goldfish (Carassius auratus). The structural domains, three-dimensional structures, and amino acid sequences of gfLyz-C1 and gfLyz-C2 were highly comparable, as the two proteins shared 89.7% sequence identity. The gfLyz-C1 and gfLyz-C2 recombinant proteins were generated in the insoluble fractions of an Escherichia coli system. Based on the results of lysoplate and turbidimetric assays, gfLyz-C1 and gfLyz-C2 showed broad-spectrum antimicrobial properties with high levels of activity against Micrococcus lysodeikticus, Vibrio parahemolyticus, and Edwardsiella tarda, and relatively low activity against E. coli. Both gfLyz-C1 and gfLyz-C2 mRNAs were mainly expressed in the trunk kidney and head kidney, and gfLyz-C1 was expressed at much higher levels than gfLyz-C2 in the corresponding tissues. The expression of the gfLyz-C1 and gfLyz-C2 transcripts in the trunk kidney and head kidney was induced in these tissues by challenge with heat-inactivated E. coli and lipopolysaccharides (LPS), and the transcriptional responses of gfLyz-C1 were more intense. In goldfish primary trunk kidney cells, the levels of the gfLyz-C1 and gfLyz-C2 transcripts were upregulated by heat-inactivated E. coli, V. parahemolyticus, and E. tarda, as well as LPS, and downregulated by treatment with dexamethasone and leptins. Overall, this study may provide new insights that will improve our understanding of the roles of c-type lysozymes in the innate immunity of cyprinid fish, including the structural and phylogenetic characteristics, antimicrobial effects, and regulatory mechanism.


Assuntos
Anti-Infecciosos , Bactérias/metabolismo , Dexametasona/farmacologia , Proteínas de Peixes , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Carpa Dourada , Leptina/farmacologia , Lipopolissacarídeos/toxicidade , Muramidase , Transcrição Genética/efeitos dos fármacos , Animais , Anti-Infecciosos/química , Anti-Infecciosos/metabolismo , Proteínas de Peixes/biossíntese , Proteínas de Peixes/química , Proteínas de Peixes/genética , Carpa Dourada/genética , Carpa Dourada/metabolismo , Muramidase/biossíntese , Muramidase/química , Muramidase/genética
18.
J Photochem Photobiol B ; 203: 111776, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31931388

RESUMO

Due to the emergence of antibiotic resistance, antimicrobial photodynamic therapy (aPDT) has recently been demonstrated as a promising alternative to antibiotics to treat wound infections caused by multidrug-resistant (MDR) pathogens. This study aimed to evaluate the bacterial killing efficiency of aPDT mediated by methylene blue (MB) loaded thermosensitive hydrogels against methicillin-resistant Staphylococcus aureus (MRSA). Box-Behnken Design method was employed to investigate the impacts of the polymer compositions, Poloxamer 407, Poloxamer 188 and Carbopol 934P, on the gelation temperature (Tsol-gel) and release rate of MB. The viscosity and in vitro bacterial killing efficiency of three selected formulations with Tsol-gel ranged 25-34 °C and MB release in 2 h (the incubation time used for aPDT experiment) ≥ 70%, were assessed. The viscosity was found to increase with increasing P407 content and increasing total gel concentration. In the in vitro aPDT experiment, all tested MB-hydrogels demonstrated >2.5 log10 colony forming unit (CFU) reduction against three clinical relevant MRSA strains. Interestingly, the bacterial reduction increased with decreasing amount of gel added (reduced MB concentration). This was possibly attributed to the increased viscosity at higher gel concentration reducing the diffusion rate of released MB towards bacterial cells leading to reduced aPDT efficiency. In summary, aPDT with the thermosensitive MB hydrogel formulations is a promising treatment strategy for wound infections.


Assuntos
Anti-Infecciosos/química , Hidrogéis/química , Azul de Metileno/química , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Luz , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Azul de Metileno/metabolismo , Azul de Metileno/farmacologia , Reologia , Temperatura , Viscosidade
19.
Mol Microbiol ; 113(3): 580-587, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31975454

RESUMO

The Introduction of antibiotics into the clinical use in the middle of the 20th century had a profound impact on modern medicine and human wellbeing. The contribution of these wonder molecules to public health and science is hard to overestimate. Much research has informed our understanding of antibiotic mechanisms of action and resistance at inhibitory concentrations in the lab and in the clinic. Antibiotics, however, are not a human invention as most of them are either natural products produced by soil microorganisms or semisynthetic derivatives of natural products. Because we use antibiotics to inhibit the bacterial growth, it is generally assumed that growth inhibition is also their primary ecological function in the environment. Nevertheless, multiple studies point to diverse nonlethal effects that are exhibited at lower levels of antibiotics. Here we review accumulating evidence of antibiosis and of alternative functions of antibiotics exhibited at subinhibitory concentrations. We also speculate on how these effects might alter phenotypes, fitness, and community composition of microbes in the context of the environment and suggest directions for future research.


Assuntos
Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Fenômenos Ecológicos e Ambientais/efeitos dos fármacos , Antibacterianos/farmacologia , Antibiose/genética , Antibiose/fisiologia , Humanos , Microbiologia do Solo
20.
Fish Shellfish Immunol ; 98: 414-419, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31962148

RESUMO

Anti-lipopolysaccharide factors (ALFs), as main host-defense molecules of crustaceans, form a unique family of antimicrobial peptides (AMPs). MnALF4 is one isoform of ALFs isolated from the freshwater prawn Macrobrachium nipponense. In the present study, MnALF4 gene was successfully expressed in the yeast Pichia pastoris and the recombinant MnALF4 protein exhibited efficient and broad-spectrum antimicrobial activities against both Gram-positive bacteria and Gram-negative bacteria in vitro. When prawns were injected with rMnALF4 before bacterial challenge with E. coli, the recombinant protein effectively promote the elimination of bacteria by the host. It manifested that rMnALF4 could effectively kill the invading bacteria in vivo. Treatment with rMnALF4 led to remarkable changes in bacterial morphology, such as spheroidization, oversized bacteria, and cell lysis. In addition, rMnALF4 showed weak hemolysis activity to the rabbit red blood cells. Our work suggests that MnALF4 plays an important role in Macrobrachium immunity and is worthy of further investigation as a potential antibacterial agent with high efficacy against bacterial infection and low toxicity to host cells.


Assuntos
Proteínas de Artrópodes/metabolismo , Lipopolissacarídeos/imunologia , Palaemonidae/metabolismo , Pichia/metabolismo , Proteínas Recombinantes/metabolismo , Animais , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Proteínas de Artrópodes/química , Proteínas de Artrópodes/genética , Bactérias/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Regulação da Expressão Gênica , Hemólise/efeitos dos fármacos , Pichia/genética , Coelhos , Proteínas Recombinantes/genética
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