RESUMO
Mycobacterium abscessus subsp. massiliense, a rapidly growing mycobacteria (RGM) that is becoming increasingly important among human infectious diseases, is virulent and pathogenic and presents intrinsic resistance to several antimicrobial drugs that might hamper their elimination. Therefore, the identification of new drugs to improve the current treatment or lower the risk of inducing resistance is urgently needed. Wasp venom primarily comprises peptides that are responsible for most of the biological activities in this poison. Here, a novel peptide Polydim-I, from Polybia dimorpha Neotropical wasp, was explored as an antimycobacterial agent. Polydim-I provoked cell wall disruption and exhibited non-cytotoxicity towards mammalian cells. Polydim-I treatment of macrophages infected with different M. abscessus subsp. massiliense strains reduced 40 to 50% of the bacterial load. Additionally, the Polydim-I treatment of highly susceptible mice intravenously infected with M. abscessus subsp. massiliense induced 0.8 to 1 log reduction of the bacterial load in the lungs, spleen, and liver. In conclusion, this is the first study to show the therapeutic potential of a peptide derived from wasp venom in treating mycobacteria infections. Polydim-I acts on the M. abscessus subsp. massiliense cell wall and reduce 40-90% of the bacterial load both in vitro and in vivo. The presented results encourage further studies on the use of Polydim-I as one of the components for M. abscessus subsp. massiliense treatment.
Assuntos
Antibacterianos/farmacologia , Infecções por Mycobacterium/tratamento farmacológico , Mycobacterium/efeitos dos fármacos , Peptídeos/farmacologia , Vespas/metabolismo , Sequência de Aminoácidos , Animais , Antibacterianos/química , Linhagem Celular , Células Cultivadas , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Proteínas de Insetos/química , Proteínas de Insetos/farmacologia , Interferon gama/deficiência , Interferon gama/genética , Macrófagos/efeitos dos fármacos , Macrófagos/microbiologia , Camundongos Endogâmicos BALB C , Camundongos Knockout , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Mycobacterium/fisiologia , Mycobacterium/ultraestrutura , Infecções por Mycobacterium/genética , Infecções por Mycobacterium/microbiologia , Peptídeos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Venenos de Vespas/metabolismoRESUMO
The associated use of the modified Middlebrook 7H11 agar thin layer technique and the Polymerase Chain Reaction (PCR) assay enabled to perform the early identification of microcolonies of Mycobacterium bovis from 12th to 25th day of culture. In order to reduce the time for performing the Mycobacterium bovis identification, the combined use of these two techniques was evaluated by analyzing the microcolonies of mycobacteria at the 8th day after culturing. Until the last day of analysis, all of the PCR-positive samples already showed the microcolonies. Therefore, the early diagnosis of bovine tuberculosis is feasible, without an apparent macroscopic colonies growth.(AU)
A associação da técnica de cultivo em camada delgada no meio de ágar Middlebrook 7H11 modificado com a Reação de Polimerase em Cadeia (PCR) possibilitou a identificação precoce de Mycobacterium bovis em colônias macroscópicas entre o 12º e o 25º dia de crescimento. Com o objetivo de diminuir o tempo necessário para efetuar a identificação de Mycobacterium bovis, avaliou-se o uso combinadodessas duas técnicas, em microcolônias de micobactérias, no oitavo dia pós-semeadura. Até o último dia de observação, todas as amostras com positividade no ensaio da PCR já apresentavam crescimento microscópico, possibilitando-se a realização de diagnóstico precoce da tuberculose bovina mesmo sem aparente crescimento macroscópico das colônias.(AU)
Assuntos
Humanos , Animais , Mycobacterium/ultraestrutura , Tuberculose , Diagnóstico PrecoceRESUMO
Tuberculosis, caused by Mycobacterium tuberculosis, and leprosy, caused by M. leprae, are diseases known since antiquity. In developing countries, tuberculosis is still the leading cause of mortality due to an infectious disease. Taxonomically, mycobacteria belong to the genus Mycobacterium, which is the single genus within the family of Mycobacteriaceae, in the order Actinomycetales. Actinomycetales include diverse micro-organisms, but mycobacteria and allied taxa are easily distinguished on the basis of the ability to synthesise mycolic acids. Mycobacterial species are traditionally differentiated on the basis of phenotypic characteristics, and the authors provide an updated list of the biochemical tests currently employed and the culture properties that help to discriminate among various species of mycobacteria. However, as the phenotypic characteristics do not allow precise identification of all species, recent molecular taxonomical approaches for mycobacterial classification and phylogeny are also described. Mycobacteria are also a leading cause of infection in various domesticated animals and wildlife. The authors briefly describe the mycobacteria involved in animal infections, the wildlife reservoirs and strategies to control bovine tuberculosis, and the use of molecular tools for diagnostics and epidemiology of mycobacterial infections in animals. The characteristic of intracellular parasitism is discussed, in addition to the fate of pathogenic mycobacteria that have the ability to grow inside phagosomes and phagolysosomes of infected host macrophages. The mycobacterial cell envelope, which is a complex tripartite structure containing a high proportion of lipids (approximately 30% to 40% of the total weight) could play a crucial role in the adaptation of mycobacteria to intracellular growth and survival, immune modulation and drug resistance.
Assuntos
Infecções por Mycobacterium/veterinária , Mycobacterium/classificação , Mycobacterium/patogenicidade , Terminologia como Assunto , Animais , Bovinos , Classificação/métodos , Impressões Digitais de DNA/veterinária , DNA Bacteriano/genética , Genótipo , Humanos , Mycobacterium/genética , Mycobacterium/ultraestrutura , Infecções por Mycobacterium/microbiologia , Infecções por Mycobacterium/prevenção & controle , Ácidos Micólicos/metabolismo , Fenótipo , Filogenia , Polimorfismo de Fragmento de Restrição , Tuberculose Bovina/microbiologia , Tuberculose Bovina/prevenção & controleRESUMO
Cellular aggregation, which occurs in both prokaryotes and eukaryotes, is controlled by the hydrophobicity as well as the electrokinetic potential of the cell surface and substratum. It is known that the Mycobacterium genus form aggregates, but the influence of sugar on the cellular aggregation has not been reported for this genus. The mutant strain Mycobacterium sp. MB-3683 that transforms sterol to androstenedione (AD), a steroidal precursor used by the pharmaceutical industries, was employed in this study. This strain was cultivated in a synthetic medium on three sugars (glycerol, glucose and fructose) at different concentrations, and at 144 h microbial growth, cellular aggregation, hydrophobicity, lipid content, fatty acid composition, and width of cellular walls were measured. It was observed that at different sugar concentrations, similar growth and pH were obtained. However, in fructose, the aggregation level was significantly high, followed by glycerol and glucose (fructose < glycerol < glucose). These results were confirmed using electron microscopy and the aggregate area quantified by image analysis. Hydrophobicity was the highest in fructose and the lowest in glucose. The total lipids, in contrast to cellular hydrophobicity, were higher in glucose than glycerol. Although, the hydrophilic-lipophilic balance (HLB) of principal fatty acids isolated was similar regardless of sugar used. In glycerol and fructose, the paraffins were observed, which are responsible for the high cellular hydrophobicity detected above. The width of cell wall of the organisms grown on glucose and fructose was similar, but in glycerol the walls were very thin. There is a correspondence between cell wall width and lipid content.
Assuntos
Mycobacterium/crescimento & desenvolvimento , Mycobacterium/ultraestrutura , Técnicas Bacteriológicas , Carbono/farmacologia , Parede Celular/química , Parede Celular/efeitos dos fármacos , Parede Celular/fisiologia , Ácidos Graxos/análise , Floculação , Frutose/farmacologia , Glucose/farmacologia , Glicerol/farmacologia , Microscopia Eletrônica , Microscopia de Vídeo , Mycobacterium/químicaRESUMO
Different immunomodulators have been previously tested in our laboratory as enhancers of the specific immune response to FMDV vaccines in a murine model [2-4]. Here, we present results of two of these immunomodulators, a water-soluble fraction of the cell wall of Mycobacterium sp. (WSF) and a synthetic lipoamide, Avridine (AV), which were tested in bovines included in FMDV oil vaccines. Two different concentrations of inactivated viral antigen were employed and the effect of different concentrations of the adjuvants were studied when added to the lower viral dose. It is shown that the inclusion of these adjuvants in the higher concentration in vaccines formulated with low antigen concentration induced the same antibody levels as those induced by vaccines containing twice the concentration of virus, and no adjuvants, and as a commercial formulation which performed with 100% of protection in the potency test. The IgG isotypes profiles induced in these experimental vaccines differed from those elicited by the commercial and control vaccines. Both IgG1 and IgG2 were augmented by the experimental formulations. These adjuvants, specially the WSF, also enhanced the cellular immune response against the FMDV in antigen driven proliferation assays, thus acting on a broad range of immune mechanisms.
Assuntos
Adjuvantes Imunológicos/farmacologia , Aphthovirus/imunologia , Doenças dos Bovinos/prevenção & controle , Diaminas/farmacologia , Febre Aftosa/prevenção & controle , Vacinas Virais , Animais , Anticorpos Monoclonais , Anticorpos Antivirais/biossíntese , Bovinos , Divisão Celular/imunologia , Parede Celular/imunologia , Imunoglobulina G/imunologia , Mycobacterium/imunologia , Mycobacterium/ultraestrutura , Solubilidade , Água/químicaRESUMO
Se efectuó un estudio de la acción del Agua del Volcán Copahue (AVC), Neuquén, Argentina, sobre 15 cepas de microbacterias Mycobacterium tuberculosis: M. bovis y los mycobacterum no tuberculosos ("Atipicos"), poniendo especial interés en los que forman "cuerdas". Se utilizó AVC con su pH l,3 y se la llevó a pH 6,5. En los bacilos que resistieron la acción del agua hasta el momento de la coloración, se advirtieron elementos más o menos alterados. Al aumentar el tiempo de contacto se llegó a la destrucción total, observándose en algunos casos muy pocos bacilos aislados, material deteriorado y formas granulares. Estas alteraciones fueron mucho más marcadas en las suspensiones que en el líquido del sedimento con el AVC; en las primeras directamente no se llegó a reparar la formación de cuerdas en ningun momento aun en bacilos que deberían formarla. Su acción no estaría asociada a una reacción bioquímica responsable en la síntesis de la pared celular, como la transpeptidación. El AVC actuaría sobre la síntesis del ácido micólico y se trataría de un agente bacteriolítico. Además se realizaron estudios en el "Laboratorio de tratamiento de imágenes", INEUCI (Instituto de Neurociencia), CONICET
Assuntos
Mycobacterium bovis/citologia , Mycobacterium tuberculosis/citologia , Micobactérias não Tuberculosas/citologia , Água/química , Ácidos Micólicos/síntese química , Aderência Bacteriana/efeitos dos fármacos , beta-Lactamases , Formas Bacterianas Atípicas , Mycobacterium/química , Mycobacterium/enzimologia , Mycobacterium/ultraestrutura , Virulência/efeitos dos fármacosRESUMO
Se efectuó un estudio de la acción del Agua del Volcán Copahue (AVC), Neuquén, Argentina, sobre 15 cepas de microbacterias Mycobacterium tuberculosis: M. bovis y los mycobacterum no tuberculosos ("Atipicos"), poniendo especial interés en los que forman "cuerdas". Se utilizó AVC con su pH l,3 y se la llevó a pH 6,5. En los bacilos que resistieron la acción del agua hasta el momento de la coloración, se advirtieron elementos más o menos alterados. Al aumentar el tiempo de contacto se llegó a la destrucción total, observándose en algunos casos muy pocos bacilos aislados, material deteriorado y formas granulares. Estas alteraciones fueron mucho más marcadas en las suspensiones que en el líquido del sedimento con el AVC; en las primeras directamente no se llegó a reparar la formación de cuerdas en ningun momento aun en bacilos que deberían formarla. Su acción no estaría asociada a una reacción bioquímica responsable en la síntesis de la pared celular, como la transpeptidación. El AVC actuaría sobre la síntesis del ácido micólico y se trataría de un agente bacteriolítico. Además se realizaron estudios en el "Laboratorio de tratamiento de imágenes", INEUCI (Instituto de Neurociencia), CONICET
Assuntos
Mycobacterium tuberculosis/citologia , Mycobacterium bovis/citologia , Micobactérias não Tuberculosas/citologia , Água/química , Virulência/efeitos dos fármacos , Mycobacterium/enzimologia , Mycobacterium/química , Mycobacterium/ultraestrutura , Ácidos Micólicos/síntese química , Aderência Bacteriana/efeitos dos fármacos , Formas Bacterianas Atípicas/efeitos dos fármacos , beta-LactamasesRESUMO
The international working group on mycobacterial taxonomy has undertaken a series of cooperative studies to standardize and establish reproducibility of tests that are useful for classifying and identifiing mycobateria. To date 25 techniques have been examined and 5 of these met our rigours criteria for reproducibilith and defferentiasl power. The properties determined by these tests are urease activity pigment production tolerence to 5 por cento NaCI hydrolsis of tween 80 and B-galactosidade activity.