RESUMO
The pollution of aquatic environments by drugs is a problem for which scarce research has been conducted in regards of their removal. Amycolatopsis sp. Poz 14 presents the ability to biotransformation naphthalene at high efficiency, therefore, in this work this bacterium was proposed as an assimilator of naproxen and carbamazepine. Growth curves at different concentrations of naproxen and carbamazepine showed that Amycolatopsis sp. Poz 14 is able to utilize these drugs at a concentration of 50 mg L-1 as a source of carbon and energy. At higher concentrations, the bacterial growth was inhibited. The transformation kinetics of naproxen showed the total elimination of the compound in 18 days, but carbamazepine was only eliminated in 19.9%. The supplementation with cometabolites such as yeast extract and naphthalene (structure similar to naproxen) at 50 mg L-1, showed that the yeast extract shortened the naproxen elimination to 6 days and reached a higher global consumption rate compared to the naphthalene cometabolite. The biotransformation of carbamazepine was not improved by the addition of cometabolites. The partial sequencing of the genome of Amycolatopsis sp. Poz 14 detected genes encoding putative enzymes for the degradation of cyclic aromatic compounds and the activities of aromatic monooxygenase, catechol 1,2-dioxygenase and gentisate 1,2-dioxygenase exhibited their involving in the naproxen biodegradation. The HPLC-MS analysis detected the 5-methoxysalicylic acid at the end of the biotransformation kinetics. This work demonstrates that Amycolatopsis sp. Poz 14 utilizes naproxen and transforms it to 5-methoxysalicylic acid which is the initial compound for the catechol and gentisic acid metabolic pathway.
Assuntos
Actinomycetales/enzimologia , Actinomycetales/metabolismo , Redes e Vias Metabólicas , Naproxeno/metabolismo , Actinomycetales/efeitos dos fármacos , Actinomycetales/crescimento & desenvolvimento , Biodegradação Ambiental , Biotransformação , Carbamazepina/metabolismo , Carbamazepina/farmacologia , Carbono/metabolismo , Catecol 1,2-Dioxigenase , Catecóis , Dioxigenases , Poluição Ambiental , Gentisatos , Éteres de Hidroxibenzoatos/metabolismo , Cinética , Oxigenases de Função Mista , Naftalenos/metabolismo , Naproxeno/farmacologia , Salicilatos/metabolismoRESUMO
One of the significant obstacles to the growth of sugarcane production is the infection by phytopathogens, mainly by the bacterium Leifsonia xyli subsp. xyli (Lxx) causal agent of Ratoon stunting disease. Thus, this research aimed to evaluate the effects of kasugamycin on the in vitro growth of sugarcane, as well as its effect on the bacterium Lxx. Explants of strain SP791011 from sugarcane were inoculated in MS culture medium supplemented with the antimicrobial kasugamycin at concentrations of 0.00; 0.87; 1.08; 1.74 and 3.48 mL.L-1, where they remained for 30 days. After this period, the survival rate, shoot number per explant, height of the explants, phytomass, dry phytomass and phytosanitary were evaluated based on the presence of genomic DNA of Lxx. It was verified that the culture in kasugamycin influenced the morphological variables negatively; nevertheless, the antimicrobial did not demonstrate phytotoxicity to the plants. All treatments tested in this experiment were diagnosed as positive, with DNA amplification for Lxx, despite it was observed a reduction in bacterial load, suggesting that kasugamycin at higher doses can be evaluated as an attempt to eliminate the bacterium in the in vitro cultivation of sugarcane.(AU)
Um dos maiores entraves para o crescimento da produção de cana-de-açúcar é a infecção por fitopatógenos, principalmente pela bactéria Leifsonia xyli subsp. xyli (Lxx), agente causal do raquitismo-da-soqueira, doença que mais causa perdas a cultura. Assim, este trabalho teve como objetivo, avaliar os efeitos do antimicrobiano casugamicina sobre o crescimento in vitro, bem como seu efeito sobre a infecção endógena por Lxx em cana-de-açúcar. Explantes da variedade SP791011 de cana-de-açúcar foram inoculados em meio de cultura MS suplementados com o antimicrobiano nas concentrações de 0,00; 0,87; 1,08; 1,74 e 3,48 mL.L-1, em que permaneceram por 30 dias. Após este período, foi avaliada a taxa de sobrevivência, número de brotações por explante, altura dos explantes, fitomassa, fitomassa seca e fitossanidade em relação à presença de DNA genômico de Lxx. Foi verificado que o cultivo em casugamicina influenciou de forma negativa nas variáveis morfológicas, apesar disso, o antimicrobiano não mostrou fitotoxidade às plantas. Todos os tratamentos testados neste experimento foram diagnosticados como positivos, com amplificação de DNA para Lxx, apesar de ter sido observada uma redução na carga bacteriana, sugerindo que a casugamicina em doses superiores pode ser avaliada como alternativa na tentativa de eliminar completamente a bactéria no cultivo in vitro de cana-de-açúcar.(AU)
Assuntos
Saccharum/microbiologia , Anti-Infecciosos/uso terapêutico , Anti-Infecciosos/toxicidade , Actinomycetales/efeitos dos fármacos , Saccharum/efeitos dos fármacos , Saccharum/crescimento & desenvolvimentoRESUMO
The oxidative stress response of the highly resistant actinomycete Dietzia cinnamea P4 after treatment with hydrogen peroxide (H2O2) was assessed in order to depict the possible mechanisms underlying its intrinsic high resistance to DNA damaging agents. We used transcriptional profiling to monitor the magnitude and kinetics of changes in the mRNA levels after exposure to different concentrations of H2O2 at 10 min and 1 h following the addition of the stressor. Catalase and superoxide dismutase genes were induced in different ways, according to the condition applied. Moreover, alkyl hydroperoxide reductase ahpCF, thiol peroxidase, thioredoxin and glutathione genes were upregulated in the presence of H2O2. Expression of peroxidase genes was not detected during the experiment. Overall results point to an actinomycete strain endowed with a set of enzymatic defenses against oxidative stress and with the main genes belonging to a functional SOS system (lexA, recA, uvrD), including suppression of lexA repressor, concomitantly to recA and uvrD gene upregulation upon H2O2 challenge.
Assuntos
Actinomycetales/efeitos dos fármacos , Actinomycetales/metabolismo , Peróxido de Hidrogênio/efeitos adversos , Estresse Oxidativo , Resposta SOS em Genética/fisiologia , Actinomycetales/enzimologia , Actinomycetales/genética , Proteínas de Bactérias/genética , Catalase/classificação , Catalase/genética , Dano ao DNA/efeitos dos fármacos , DNA Helicases/genética , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Genes Bacterianos , Glutationa/genética , Cinética , Peroxidases/genética , Peroxirredoxinas/genética , Filogenia , RNA Mensageiro/metabolismo , Recombinases Rec A/genética , Resposta SOS em Genética/genética , Análise de Sequência , Serina Endopeptidases/genética , Superóxido Dismutase/genética , Tiorredoxinas/genética , Fatores de Tempo , Regulação para Cima/efeitos dos fármacosRESUMO
After chloroform fumigating an arable soil, the relative abundance of phylotypes belonging to only two phyla (Actinobacteria and Firmicutes) and two orders [Actinomycetales and Bacillales (mostly Bacillus)] increased in a subsequent aerobic incubation, while it decreased for a wide range of bacterial groups. It remained to be seen if similar bacterial groups were affected when an extreme alkaline saline soil was fumigated. Soil with electrolytic conductivity between 139 and 157 dS m(-1), and pH 10.0 and 10.3 was fumigated and the bacterial community structure determined after 0, 1, 5 and 10 days by analysis of the 16S rRNA gene, while an unfumigated soil served as control. The relative abundance of the Firmicutes increased in the fumigated soil (52.8%) compared to the unfumigated soil (34.2%), while that of the Bacteroidetes decreased from 16.2% in the unfumigated soil to 8.8% in the fumigated soil. Fumigation increased the relative abundance of the genus Bacillus from 14.7% in the unfumigated soil to 25.7%. It was found that phylotypes belonging to the Firmicutes, mostly of the genus Bacillus, were dominant in colonizing the fumigated alkaline saline as found in the arable soil, while the relative abundance of a wide range of bacterial groups decreased.
Assuntos
Actinomycetales/isolamento & purificação , Bacillus/isolamento & purificação , Fumigação , Microbiota , Microbiologia do Solo , Actinomycetales/efeitos dos fármacos , Actinomycetales/genética , Álcalis/farmacologia , Bacillus/efeitos dos fármacos , Bacillus/genética , Clorofórmio/farmacologia , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
The Salta Province - in the northwest of Argentina - is the main worldwide producer of hydroboracite and leads in exports of boron mineral and its derivatives in Latin America. In addition to the natural presence of boron compounds in the soils, there are others contaminated due to the boron mining industry. Although some bacteria are known to require boron for their growth or to be capable of storing boron, no studies have been published about Streptomyces or Lentzea genera's capacity to tolerate high boron concentrations, or about their metabolic capacities in boron contaminated environments. The results of this research show the isolation and molecular characterization of eight strains belonging to the actinobacteria phylum collected from different soils contaminated with high boron concentration in Salta state. The boron tolerance assays, which show that three of the strains were able to tolerate up 60-80 mM boron, demonstrate the potential capability of this group of bacteria to grow and maybe to remove boron from the environment. They appear to be promising, considering that these microorganisms are infrequent pathogens, are metabolically versatile and many Streptomyces can synthesize boron containing metabolites.
Assuntos
Actinomycetales/efeitos dos fármacos , Actinomycetales/isolamento & purificação , Compostos de Boro/metabolismo , Tolerância a Medicamentos , Microbiologia do Solo , Solo/química , Actinomycetales/genética , Actinomycetales/fisiologia , Argentina , Metabolismo dos Carboidratos , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio/metabolismoRESUMO
Actinomycetoma is a chronic subcutaneous infection caused by aerobic branching actinomycetes. Its clinical features are firm tumefaction of the affected site and the presence of abscesses, nodules, and sinuses that drain a seropurulent exudate containing filamenting granules. The disease is caused by inoculation of the infectious agent through minor trauma in susceptible individuals. Nocardia brasiliensis, Actinomadura madurae, and Streptomyces somaliensis are among the most frequent agents in the Americas. Cellular and humoral immunity have been studied in animal models. Standard therapy for uncomplicated cases is sulfamethoxazole-trimethoprim given for many months. Bone involvement, disseminated cases, and special locations require combined treatment with amikacin and sulfamethoxazole-trimethoprim. Isolated reports include the addition of other antibiotics such as rifampicin, imipenem, or meropenem. When needed, other aminoglycosides can be used. Amoxicillin-clavulanic acid is indicated in specific cases as alternative treatment. Oxazolidinone antibiotics, such as linezolid and other similar compounds (DA-7218 and DA-7157), have been studied in experimental infections in animal models as well as in vitro and ex vivo, with encouraging results.
Assuntos
Actinomycetales/efeitos dos fármacos , Antibacterianos/uso terapêutico , Micetoma/tratamento farmacológico , Nocardia/efeitos dos fármacos , Streptomyces/efeitos dos fármacos , Amicacina/uso terapêutico , Combinação Amoxicilina e Clavulanato de Potássio/uso terapêutico , Animais , Anti-Infecciosos/uso terapêutico , Diagnóstico Diferencial , Quimioterapia Combinada , Humanos , Modelos Animais , Micetoma/patologia , Oxazolidinonas/uso terapêutico , Fatores de Tempo , Combinação Trimetoprima e Sulfametoxazol/uso terapêuticoRESUMO
Heavy metal pollution is widespread causing serious ecological problems in many parts of the world; especially in developing countries where a budget for remediation technology is not affordable. Therefore, screening for microbes with high accumulation capacities and studying their stable resistance characteristics is advisable to define cost-effective any remediation strategies. Herein, the copper-resistome of the novel copper-resistant strain Amycolatopsis tucumanensis was studied using several approaches. Two dimensional gel electrophoresis revealed that proteins of the central metabolism, energy production, transcriptional regulators, two-component system, antioxidants and protective metabolites increased their abundance upon copper-stress conditions. Transcriptome analysis revealed that in presence of copper, superoxide dismutase, alkyl hydroperoxide reductase and mycothiol reductase genes were markedly induced in expression. The oxidative damage of protein and lipid from A. tucumanensis was negligible compared with that observed in the copper-sensitive strain Amycolatopsis eurytherma. Thus, we provide evidence that A. tucumamensis shows a high adaptation towards copper, the sum of which is proposed as the copper-resistome. This adaptation allows the strain to accumulate copper and survive this stress; besides, it constitutes the first report in which the copper-resistome of a strain of the genus Amycolatopsis with bioremediation potential has been evaluated.
Assuntos
Actinomycetales/efeitos dos fármacos , Actinomycetales/genética , Cobre/toxicidade , Poluentes Ambientais/toxicidade , Actinomycetales/isolamento & purificação , Actinomycetales/metabolismo , Antioxidantes/metabolismo , Argentina , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Cobre/farmacocinética , Farmacorresistência Bacteriana/genética , Poluentes Ambientais/farmacocinética , Genoma Bacteriano , Peroxidação de Lipídeos/efeitos dos fármacos , Oxirredução , TranscriptomaRESUMO
Copper is a redox-active metal, which acts as a catalyst in the formation of Reactive Oxygen Species (ROS) encouraging oxidative stress. Protection against oxidants is intrinsic to every living cell; however, in stress conditions, cells are forced to increase and expand their antioxidative network. In this work, the novel copper-resistant strain Amycolatopsis tucumanensis and the copper-sensitive Amycolatopsis eurytherma were grown under copper increasing concentrations in order to elucidate the dissimilar effects of the metal on the strains viability, mainly on morphology and antioxidant capacity. Although biosorbed copper encouraged ROS production in a dose-dependent manner in both strains, the increase in ROS production from the basal level to the stress conditions in A. tucumanensis is lesser than in the copper-sensitive strain; likewise, in presence of copper A. eurytherma suffered inexorable morphological alteration while A. tucumanensis was not affected. The levels of antioxidant enzymes and metallothioneins (MT) were all greater in A. tucumanensis than in A. eurytherma; in addition MT levels as well as superoxide dismutase and thioredoxin reductase activities in A. tucumanensis, were higher as higher the concentration of copper in the culture medium. This work has given evidence that an efficient antioxidant defense system might aid microorganisms to survive in copper-stress conditions; besides it constitutes the first report of oxidative stress study in the genus Amycolatopsis and contributes to enlarge the knowledge on the copper-resistance mechanisms of A. tucumanensis.
Assuntos
Actinomycetales/efeitos dos fármacos , Antioxidantes/metabolismo , Cobre/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Actinomycetales/enzimologia , Actinomycetales/crescimento & desenvolvimento , Actinomycetales/ultraestrutura , Catalase/metabolismo , Metalotioneína/metabolismo , Viabilidade Microbiana , Microscopia Eletrônica de Varredura , Oxirredução , Superóxido Dismutase/metabolismo , Tiorredoxina Dissulfeto Redutase/metabolismoRESUMO
A novel actinomycete strain, ABO(T), isolated from copper-polluted sediments showed remarkable copper resistance as well as high bioaccumulation abilities. Classical taxonomic methods, including chemotaxonomy and molecular techniques, were used to characterize the isolate. Strain ABO(T) developed a honey-yellow substrate mycelium on all ISP media tested. Abundant, white, aerial mycelium was only formed on ISP 2, 5 and 7 and MM agar. Both types of hyphae fragmented into squarish rod-shaped elements. The aerial mycelium displayed spore-like structures with smooth surfaces in long, straight to flexuous chains. The organism has a type-IV cell wall lacking mycolic acids and type-A whole-cell sugar pattern (meso-diaminopimelic acid, arabinose and galactose) in addition to a phospholipid type-II profile. 16S rRNA gene sequence studies indicated that this organism is a member of the family Pseudonocardiaceae and that it forms a monophyletic clade with Amycolatopsis eurytherma NT202(T). The DNA-DNA relatedness of strain ABO(T) to A. eurytherma DSM 44348(T) was 39.5 %. It is evident from these genotypic and phenotypic data that strain ABO(T) represents a novel species in the genus Amycolatopsis, for which the name proposed is Amycolatopsis tucumanensis sp. nov. The type strain is ABO(T) (=DSM 45259(T) =LMG 24814(T)).
Assuntos
Actinomycetales/classificação , Cobre/farmacologia , Microbiologia da Água , Poluição Química da Água , Actinomycetales/efeitos dos fármacos , Actinomycetales/genética , Sequência de Bases , Farmacorresistência Bacteriana , Dados de Sequência Molecular , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Homologia de Sequência do Ácido NucleicoRESUMO
Envenoming by Crotalus durissus subspecies leads to coagulation disorders, myotoxicity, neurotoxicity and acute renal failure. The most serious systemic alteration and primary cause of death after snakebite is acute renal failure. In this work, we isolated crotapotin, an acid component (Crtp) of crotoxin from Crotalus durissus cascavella venom and we investigated its bactericidal and pro-inflammatory activities as well as its renal effects in rat isolated perfused kidneys. Crtp was bactericidal to the Gram-negative species Xanthomonas axonopodis pv. passiflorae, but was less effective against the Gram-positive Claribacteri ssp, probably because of differences in the cell wall composition. Crtp showed a high amino acid sequence homology with other Crtps described in the literature (around of 90%) and its A and B chains had high conserved regions corresponding to the calcium-binding loop, catalytic site and helix 3 of PLA2. The Crtp showed moderate pro-inflammatory activity and increased significantly the inflammation evoked by PLA2 when co-injected or co-incubated with PLA2. The renal parameters evaluated included the perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR) and percent of sodium tubular transport (%TNa+). Crotapotin (5 microg/ml) significantly increased the PP and RVR, whereas the GFR, UF and %TNa+ were unaffected. These results suggest that crotoxin is the main venom component responsible for nephrotoxicity and crotapotin contributes little to this phenomenom. The biological and bactericidal actions of Crtp also suggest that this protein may have functions other than simply acting as a chaperone for PLA2.