O trabalho foi realizado com apoio financeiro do Instituto Nacional de Saúde e American Lung Association.

1. Biofilmes de crescimento de M. tuberculose em uma garrafa de 250 ml com tampa de rosca <ol><li> Preparação Media: Dissolver 0,5 g de KH 2 PO 4, 0,5 g de MgSO4, 4g de L-asparagina, 2g de ácido cítrico, 0,05 g de citrato de amónio férrico, 60mL de glicerol em 900ml de água. Ajustar o pH a 7,0 com NaOH. Autoclave, arrefecer e imediatamente antes de se iniciar a experiência, adicionar ZnSO estéril 4 a uma concentração final de 0,1% w / v Desde mc 2 7000 é um auxotrofo pantotenato esta estirpe também requer ácido pantotênico em 10μg/mL de concentração final. </li></ol> Nota: Esta é uma composição padrão de mídia Sauton de usados ​​para M. tuberculosis. No entanto, se for necessário outros meios especializados pode também ser utilizado para outras espécies micobacterianas. <ol start="2"><li> Inóculo preparação: Crescer M. tuberculosis em 7H9OADC com 0,05% de Tween-80 durante uma semana, ou OD 600 de 0,7 a 1,0. O CuLTURE pode ser directamente utilizado como inoculo a uma diluição de 1:100. </li><li> Pipetar 25 ml de meios de comunicação para um Sauton 250mL garrafa de poliestireno parafuso capped (Corning). Adicionar 250μl do inoculo para o meio, a tampa da garrafa muito firmemente e colocá-la intacta numa humidificada a 37 ° C incubadora durante 3 semanas. Observar a garrafa uma vez em cada dia para assegurar que não há qualquer contaminação. </li><li> No final da terceira semana, soltar a tampa da garrafa, para permitir um maior crescimento de M. tuberculosis na interface. Se a tampa não está solto, nesta fase, em seguida, a concentração de oxigénio insuficiente no recipiente irá retardar o crescimento adicional de bactérias. </li></ol> 2. Crescimento de M. biofilmes de tuberculose em 12 poços <ol><li> Prepare a mídia e inóculo de mc 2 7000, conforme descrito nas seções A1 e A2. </li><li> Misture 60ml de mídia com 600μl do inóculo. Dispensar 4.5mL da mistura em cada poço da placa. Cobrir a placa com tampa. Enrole a placa várias vezes com parafilme. Incubar a placa não perturbada no incubador humidificado a 37 ° C durante 5 semanas. </li></ol> 3. Determinar a freqüência de persistentes drogas tolerantes em M. tuberculose biofilmes <ol><li> Crescer M. biofilmes de tuberculose em um formato de 12 bem como descritos na secção B. Isso vai demorar um total de cerca de 5 semanas. </li><li> Uma vez que os biofilmes são maturados (após 5 semanas de incubação) injectar a escolha do antibiótico na concentração desejada para o meio sob as biofilmes utilizando um microtip de uma pipeta. </li></ol> Nota: O volume dos meios de comunicação sob as películas reduz a cerca de 3,0 mL. Assim, os investigadores devem, por conseguinte calcular a quantidade de droga. <ol start="3"><li> Agite ligeiramente a placa de modo a que o antibiótico é completamente difundido no meio. Para obter resultados estatisticamente significativos, injetar a antibióticosótica em quatro poços. Em paralelo, injectar o mesmo volume de solvente em que o antibiótico foi dissolvido em outros quatro poços, e deixar os últimos quatro cavidades da placa intacto. Cobrir a placa com a tampa e colocar novas camadas de parafilme em torno do prato. Coloque-o de volta na incubadora por um período de tempo desejado. </li><li> No final da incubação, a placa de abrir e adicionar Tween-80 para a concentração final de 0,1% (volume / volume) em cada um dos poços. Redemoinho toda a placa suavemente para a dispersão uniforme do detergente. Incubar a placa à temperatura ambiente durante 15 minutos. Misturar o conteúdo de cada poço com uma pipeta várias vezes de modo que todo o conteúdo pode ser uniformemente transferidos para um tubo de 15 mL cónico. </li><li> Girar para baixo o conteúdo do tubo a 4000rpm durante 10 minutos à temperatura ambiente. Ressuspender o sedimento em 5 mL de tampão de lavagem fresca (PBS com 10% de glicerol e 0,05% de Tween-80). Repita as lavar três vezes. Ressuspender o sedimento em 5 mL de tampão de lavagem. Mantenha-o na cadeira de balanço para overnight a 4 ° C. </li></ol> Nota: Embora a baixa temperatura foi originalmente desenvolvida para o M. smegmatis (para minimizar o seu crescimento durante a dispersão) e utilizado para o M. tuberculosis, bem como, as espécies de crescimento lento pode provavelmente ser embalado à temperatura ambiente sem qualquer impacto no resultado. Balançando a temperatura ambiente pode ser necessário se trabalhar em BSL-3 instalações. <ol start="6"><li> Prepara-se uma seringa estéril equipado com microponta (2-200μl) cortando a sua extremidade larga para o tamanho apropriado, encaixando-lo para a seringa e envolvê-lo com parafilme. Passe todo o conteúdo do tubo através da seringa ponta-equipada e recolher em um tubo fresco 15ml. Repita este passo 5 a 6 vezes até que você observar uma suspensão bastante homogênea. </li><li> Preparar diluições em série da suspensão e da placa as diluições em placa 7H11OADC para determinar o número de colónias viáveis ​​em cada poço. Incubar as placas durante três semanas, em 37 ° C incubadora. Determinar a frecy de persistentes na população de biofilme pelo cálculo da razão entre o número de colónias obtidas em antibiótico tratados com os obtidos em solventes placas tratadas. </li></ol> 4. Os resultados representativos Quando em cultura em um frasco de crescimento, de M. tuberculosis pode ser visto na base da garrafa, até ao final da primeira semana. Ao final da segunda semana, o crescimento de bactérias irregular na interface ar-media pode ser visto, embora o crescimento na interface ar-media é consistentemente visível no final da terceira semana (Fig. 1A). Nesta altura, a fixação das bactérias à parede do recipiente é também observada. A partir deste ponto, o crescimento da cultura ocorre principalmente na interface ar-media. O líquido sob a superfície de crescimento é clara. Tipicamente, a estrutura amadurece até ao final da quinta semana (Fig. 1B). Se a incubação é prolongada, as estruturas começará a afundar-se para o fundo do recipiente. Curiosamente,aperto da tampa até que o fim da terceira semana é um passo importante no processo, e por razões desconhecidas uma garrafa solta-capped significativamente retarda o início do crescimento na interface 9. No formato de 12 poços, um biofilme robusta na interface ar-media é visto em cada um dos poços no final de cinco semanas (Fig. 2A). Se as placas não são completamente envolto em seguida, o crescimento do biofilme diferencial é observada. No pior dos casos, a evaporação meios significativo pode parar o crescimento das bactérias (Fig. 2B). Assim, o acondicionamento da placa é necessário tanto para prevenir a evaporação, bem como para fornecer um ambiente para a formação de biofilme (ver parágrafo anterior). O número de bacilos viáveis ​​em biofilmes determinados com esta técnica é bastante reprodutível. Resposta de M. tuberculose biofilmes varia com a natureza dos antibióticos. Para um antibiótico bactericida, tais como rifampicina, perda de viabilidade segue um bipha<html> sic tendência 9. Um rápido declínio na viabilidade durante os primeiros três a quatro dias, seguido por uma fase de persistente em que uma pequena percentagem da população permanecem completamente recalcitrante aos antibióticos, independentemente da concentração do antibiótico ou o tempo de exposição. A Figura 3 mostra o número de bacilos viáveis ​​em biofilmes maduros após uma exposição de 7 dias para 50μg/mL (50 vezes mais elevada do que a MIC) de rifampicina. <img alt="A Figura 1A." src="/files/ftp_upload/3820/3820fig1A.jpg" /> Figura 1A aparência. Precoce do M. bacilos da tuberculose na interface ar-media de bactérias após 3 semanas de incubação. <img alt="Figura 1B." src="/files/ftp_upload/3820/3820fig1B.jpg" /> Figura 1B. Maturados biofilmes de M. tuberculosis na interface ar-media após cinco semanas de incubação. 820/3820fig2A.jpg &quot;/&gt; Figura 2A. Com 5 semanas de idade biofilmes de M. tuberculose cultivadas em 12-formato bem. <img alt="Figura 2B." src="/files/ftp_upload/3820/3820fig2B.jpg" /> Figura 2B. Uma tentativa fracassada de crescer biofilmes de M. tuberculosis em 12-bem a chapa sem parafilme. <img alt="Figura 3." src="/files/ftp_upload/3820/3820fig3.jpg" /> Figura 3. Enredo Um representante com a frequência da persistentes drogas tolerantes em M. tuberculose biofilmes cultivadas em 12-formato bem e expostos a 50μg/mL de rifampicina, durante sete dias.

<ol>
	<li>Saltini, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemotherapy+and+diagnosis+of+tuberculosis.">Chemotherapy and diagnosis of tuberculosis.</a> Respir. Med. 100, 2085-2097 (2006).</li><li>Hall-Stoodley, L., Stoodley, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biofilm+formation+and+dispersal+and+the+transmission+of+human+pathogens.">Biofilm formation and dispersal and the transmission of human pathogens.</a> Trends Microbiol. 13, 7-10 (2005).</li><li>Costerton, J. W., Stewart, P. S., Greenberg, E. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bacterial+biofilms:+a+common+cause+of+persistent+infections.">Bacterial biofilms: a common cause of persistent infections.</a> Science. 284, 1318-1322 (1999).</li><li>Blankenship, J. R., Mitchell, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+build+a+biofilm:+a+fungal+perspective.">How to build a biofilm: a fungal perspective.</a> Curr Opin Microbiol. 9, 588-594 (2006).</li><li>Henke, J. M., Bassler, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bacterial+social+engagements.">Bacterial social engagements.</a> Trends Cell Biol. 14, 648-656 (2004).</li><li>Kolter, R., Losick, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One+for+all+and+all+for+one.">One for all and all for one.</a> Science. 280, 226-227 (1998).</li><li>Branda, S. S., Vik, S., Friedman, L., Kolter, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biofilms:+the+matrix+revisited.">Biofilms: the matrix revisited.</a> Trends Microbiol. 13, 20-26 (2005).</li><li>Ojha, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GroEL1:+a+dedicated+chaperone+involved+in+mycolic+acid+biosynthesis+during+biofilm+formation+in+mycobacteria.">GroEL1: a dedicated chaperone involved in mycolic acid biosynthesis during biofilm formation in mycobacteria.</a> Cell. 123, 861-873 (2005).</li><li>Ojha, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+of+Mycobacterium+tuberculosis+biofilms+containing+free+mycolic+acids+and+harbouring+drug-tolerant+bacteria.">Growth of Mycobacterium tuberculosis biofilms containing free mycolic acids and harbouring drug-tolerant bacteria.</a> Mol. Microbiol. 69, 164-174 (2008).</li><li>Ojha, A. K., Trivelli, X., Guerardel, Y., Kremer, L., Hatfull, G. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enzymatic+hydrolysis+of+trehalose+dimycolate+releases+free+mycolic+acids+during+mycobacterial+growth+in+biofilms.">Enzymatic hydrolysis of trehalose dimycolate releases free mycolic acids during mycobacterial growth in biofilms.</a> J. Biol. Chem. 285, 17380-17389 (2010).</li><li>Dye, C., Lonnroth, K., Jaramillo, E., Williams, B. G., Raviglione, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trends+in+tuberculosis+incidence+and+their+determinants+in+134+countries.">Trends in tuberculosis incidence and their determinants in 134 countries.</a> Bull World Health Organ. 87, 683-691 (2009).</li><li>Jindani, A., Dore, C. J., Mitchison, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bactericidal+and+sterilizing+activities+of+antituberculosis+drugs+during+the+first+14+days.">Bactericidal and sterilizing activities of antituberculosis drugs during the first 14 days.</a> Am. J. Respir. Crit. Care Med. 167, 1348-1354 (2003).</li><li>Carter, G., Wu, M., Drummond, D. C., Bermudez, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+biofilm+formation+by+clinical+isolates+of+Mycobacterium+avium.">Characterization of biofilm formation by clinical isolates of Mycobacterium avium.</a> J. Med. Microbiol. 52, 747-752 (2003).</li><li>Hall-Stoodley, L., Lappin-Scott, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biofilm+formation+by+the+rapidly+growing+mycobacterial+species+Mycobacterium+fortuitum.">Biofilm formation by the rapidly growing mycobacterial species Mycobacterium fortuitum.</a> FEMS Microbiol. Lett. 168, 77-84 (1998).</li><li>Alibaud, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature-dependent+regulation+of+mycolic+acid+cyclopropanation+in+saprophytic+mycobacteria:+role+of+the+Mycobacterium+smegmatis+1351+gene+(MSMEG_1351)+in+CIS-cyclopropanation+of+alpha-mycolates.">Temperature-dependent regulation of mycolic acid cyclopropanation in saprophytic mycobacteria: role of the Mycobacterium smegmatis 1351 gene (MSMEG_1351) in CIS-cyclopropanation of alpha-mycolates.</a> J. Biol. Chem. 285, 21698-21707 (2010).</li></ol>

Não temos nada a divulgar.

A tuberculose (TB), causada pela infecção do Mycobacterium tuberculosis, continua a ser uma grande ameaça à saúde pública global. Quase um terço da população mundial é estimada para ser assintomática infectada pelo patógeno, cerca de 9 milhões de novos casos aparecem na clínica todos os anos com sintomas de tuberculose ativa e cerca de 1,7 milhões morrem da infecção a cada ano 11. O enorme fardo da doença é essencialmente contribuído por falta de uma vacina e uma quimioterapia mui...

<table border="1">
	<tbody>
		<tr>
			<td>Equipment and supplies</td>
			<td>SUPPLIER</td>
			<td>CATALOG NUMBER</td>
		</tr>
		<tr>
			<td>Incubator</td>
			<td>VWR</td>
			<td>Model # 1923/25</td>
		</tr>
		<tr>
			<td>Polystyrene culture bottles</td>
			<td>Fisher Scientific</td>
			<td>03-374-300</td>
		</tr>
		<tr>
			<td>12-well tissue culture plate</td>
			<td>VWR</td>
			<td>62406-165</td>
		</tr>
		<tr>
			<td>50-mL conical tubes</td>
			<td>VWR</td>
			<td>89039-660</td>
		</tr>
		<tr>
			<td>Rocker</td>
			<td>Thermo Scientific</td>
			<td>57019-662</td>
		</tr>
		<tr>
			<td>Chromatographic refrigerator</td>
			<td>VWR</td>
			<td>55702-520</td>
		</tr>
		<tr>
			<td>petri dish</td>
			<td>VWR</td>
			<td>25384-342</td>
		</tr>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>REAGENT</td>
			<td>SUPPLIER</td>
			<td>CATALOG NUMBER</td>
		</tr>
		<tr>
			<td>KH2PO4 (monobasic)</td>
			<td>EMD</td>
			<td>PX1565-1</td>
		</tr>
		<tr>
			<td>MgSO4</td>
			<td>Fisher</td>
			<td>M65-500</td>
		</tr>
		<tr>
			<td>L-asparagine</td>
			<td>Sigma</td>
			<td>A4284-100G</td>
		</tr>
		<tr>
			<td>citric acid</td>
			<td>Sigma</td>
			<td>C1857-100G</td>
		</tr>
		<tr>
			<td>ferric ammonium citrate</td>
			<td>Sigma</td>
			<td>F5879-100G</td>
		</tr>
		<tr>
			<td>glycerol</td>
			<td>EMD</td>
			<td>GX0185-5</td>
		</tr>
		<tr>
			<td>NaOH</td>
			<td>Sigma</td>
			<td>S8045-500G</td>
		</tr>
		<tr>
			<td>ZnSO4</td>
			<td>Sigma</td>
			<td>Z4750-500G</td>
		</tr>
		<tr>
			<td>D-pantothenic acid</td>
			<td>Sigma</td>
			<td>P2250-25G</td>
		</tr>
		<tr>
			<td>Difco Middlebrook 7H9 Broth</td>
			<td>Becton Dickinson</td>
			<td>271310</td>
		</tr>
		<tr>
			<td>Middlebrook OADC Enrichment</td>
			<td>BBL</td>
			<td>212351</td>
		</tr>
		<tr>
			<td>Tween-80</td>
			<td>Fisher</td>
			<td>T164-500</td>
		</tr>
		<tr>
			<td>250mL storage bottle</td>
			<td>Corning</td>
			<td>430281</td>
		</tr>
		<tr>
			<td>12 well plates</td>
			<td>Falcon (BD)</td>
			<td>353043</td>
		</tr>
		<tr>
			<td>rifampicin</td>
			<td>Sigma</td>
			<td>R3501-1G</td>
		</tr>
		<tr>
			<td>methanol</td>
			<td>J.T. Baker</td>
			<td>9070-05</td>
		</tr>
		<tr>
			<td>10mlLsyringe</td>
			<td>Becton Dickinson</td>
			<td>301604</td>
		</tr>
		<tr>
			<td>1-200&mu;L pipet tips</td>
			<td>VWR</td>
			<td>89079-458</td>
		</tr>
		<tr>
			<td>parafilm M</td>
			<td>VWR</td>
			<td>PM-996</td>
		</tr>
		<tr>
			<td>15mL centrifuge tube</td>
			<td>Greiner Bio-One</td>
			<td>188-285</td>
		</tr>
		<tr>
			<td>Difco Mycobacteria 7H11 Agar</td>
			<td>Becton Dickinson</td>
			<td>283810</td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Fisher</td>
			<td>BP358-1</td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>Sigma</td>
			<td>P9333-500G</td>
		</tr>
		<tr>
			<td>Na2HPO4 (dibasic)</td>
			<td>Sigma</td>
			<td>S0876-500G</td>
		</tr>
	</tbody>
</table>

growth of mycobacterium tuberculosis biofilms

Mycobacterium tuberculosis, agente etiológico da tuberculose humana, tem uma capacidade extraordinária para sobreviver contra estresses ambientais, incluindo antibióticos. Embora a tolerância ao estresse de M. tuberculose é um dos provavelmente contribui para a quimioterapia 6-mês longo da tuberculose 1, os mecanismos moleculares subjacentes ao fenótipo característica do agente patogénico permanecem incertos. Muitas espécies microbianas evoluíram para sobreviver em ambientes estressantes por auto-montagem em superfície altamente organizada, em anexo, e estruturas matriciais encapsulados chamados biofilmes 2-4. Crescimento em comunidades parece ser uma estratégia de sobrevivência preferida de micróbios, e é conseguida por meio de componentes genéticos que regulam fixação superfície, as comunicações intercelulares, e síntese de substâncias poliméricas extracelulares (EPS) 5,6. A tolerância ao estresse ambiental é provavelmente facilitada pela EPS, e talvez pelo fisiolóadaptação tecnológico de bacilos indivíduo a microambientes heterogêneos dentro da complexa arquitetura de biofilmes 7. Em uma série de trabalhos recentes, estabeleceu que M. tuberculosis e Mycobacterium smegmatis têm uma forte propensão para crescer em organizados estruturas multicelulares, chamado biofilmes, que pode tolerar mais de 50 vezes as concentrações inibitórias mínimas das drogas anti-tuberculose isoniazida e rifampicina 8-10. M. tuberculose, no entanto, intrigantemente requer condições específicas para formar biofilmes maduros, em proporção de 9:1 particular de headspace: meios bem como a troca limitada de ar com a atmosfera 9. Requisitos de especializados condições ambientais poderia possivelmente ser ligada ao facto de que a M. tuberculosis é um patógeno humano obrigatório e, portanto, se adaptou aos ambientes de tecido. Nesta publicação, demonstrar os métodos para cultura de M. tuberculosebiofilme em uma garrafa e um formato de placa de 12 poços, que é conveniente para estudos bacteriológicos, bem como genéticos. Nós descrevemos o protocolo para uma estirpe atenuada de M. tuberculose, mc dois 7000, com supressão nos dois loci, panCD e RD1, que são críticas para crescimento in vivo do agente patogénico 9. Esta variedade pode ser usado com segurança em uma contenção BSL-2 para a compreensão da biologia básica do patógeno tuberculose, evitando assim a exigência de uma instalação de BSL-3 caro. O método pode ser estendida, com modificação adequada em meios de comunicação, a crescer biofilme de outras espécies de micobactérias cultiváveis. Em geral, um protocolo uniforme de biofilmes cultura de micobactérias vai ajudar os pesquisadores interessados ​​em estudar as características básicas resistentes de micobactérias. Além disso, um método claro e conciso do crescimento de biofilmes de micobactérias também irá ajudar o inv clínica e farmacêuticaestigators para testar a eficácia de um fármaco potencial.

Watch this Scientific Journal Video about Growth of Mycobacterium tuberculosis Biofilms at JoVE.com

Growth of Mycobacterium tuberculosis Biofilms

Mycobacterium tuberculosis forma biofilmes de drogas tolerantes quando cultivadas em certas condições. Aqui descrevemos métodos para cultura de M. biofilmes de tuberculose e que determinam a freqüência de persistentes drogas tolerantes. Estes protocolos serão úteis para estudos posteriores sobre os mecanismos de tolerância à droga em M. tuberculose.

Crescimento de Mycobacterium tuberculosis Biofilmes

Mycobacterium tuberculosis, the etiologic agent of human tuberculosis, has an extraordinary ability to survive against environmental stresses including ...

growth-of-mycobacterium-tuberculosis-biofilms

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Immunology and Infection

Growth of Mycobacterium tuberculosis Biofilms

23.6K visualizações.  University of Pittsburgh. Mycobacterium tuberculosis forma biofilmes de drogas tolerantes quando cultivadas em certas condições. Aqui descrevemos métodos para cultura de M. biofilmes de tuberculose e que determinam a freqüência de persistentes drogas tolerantes. Estes protocolos serão úteis para estudos posteriores sobre os mecanismos de tolerância à droga em M. tuberculose.

Vídeo: Growth of Mycobacterium tuberculosis Biofilms

Antimicrobial Susceptibility Testing of Mycobacterium Tuberculosis Complex for First and Second Line Drugs by Broth Dilution in a Microtiter Plate Format

The rapid detection of antimicrobial resistance is important in the effort to control the increase in resistant Mycobacterium 
tuberculosis (Mtb). Antimicrobial susceptibility testing (AST) of Mtb has traditionally been performed by the agar method of proportion or by 
macrobroth testing on an instrument such as the BACTEC (Becton Dickinson, Sparks, MD), VersaTREK (TREK Diagnostics, Cleveland, OH) or BacT/ALERT (bioM&eacute;rieux, Hazelwood, MO). The agar proportion method, while considered the &#x201C;gold&#x201D; standard of AST, is labor intensive and requires calculation of resistance by performing colony counts on drug-containing agar as compared to drug-free agar. If there is &ge;1% growth on the drug-containing medium as compared to drug-free medium, the organism is considered resistant to that drug. The macrobroth methods require instrumentation and test break point ("critical") drug concentrations for the first line drugs (isoniazid, ethambutol, rifampin, and pyrazinamide). The method described here is commercially available in a 96 well microtiter plate format [MYCOTB (TREK Diagnostics)] and contains increasing concentrations of 12 antimicrobials used for treatment of tuberculosis including both first (isoniazid, rifampin, ethambutol) and second line drugs (amikacin, cycloserine, ethionamide, kanamycin, moxifloxacin, ofloxacin, para-aminosalicylic acid, rifabutin, and streptomycin). Pyrazinamide, a first line drug, is not included in the microtiter plate due to its need for acidic test conditions. Advantages of the microtiter system include both ease of set up and faster turn around time (14 days) compared with traditional agar proportion (21 days). In addition, the plate can be set up from inoculum prepared using either broth or solid medium. Since the microtiter plate format is new and since Mtb presents unique safety challenges in the laboratory, this protocol will describe how to safely setup, incubate and read the microtiter plate.

Antimicrobial susceptibility testing of Mycobacterium tuberculosis is challenging but critical for patient care. This microtiter plate format offers testing of 12 antimycobacterial drugs and provides minimum inhibitory concentration (MIC) values, which will aid in appropriate treatment.

Teste de susceptibilidade antimicrobiana do complexo Mycobacterium tuberculosis da Droga primeira e segunda linha de diluição em caldo em um formato de placa de microtitulação

The rapid detection of antimicrobial resistance is important in the effort to control the increase in resistant Mycobacterium 
tuberculosis (Mtb). ...

Imunologia e Infecção

Sample Preparation of Mycobacterium tuberculosis Extracts for Nuclear Magnetic Resonance Metabolomic Studies

Mycobacterium tuberculosis is a major cause of mortality in human beings on a global scale. The emergence of both multi- (MDR) and extensively-(XDR) drug-resistant strains threatens to derail current disease control efforts. Thus, there is an urgent need to develop drugs and vaccines that are more effective than those currently available. The genome of M. tuberculosis has been known for more than 10 years, yet there are important gaps in our knowledge of gene function and essentiality. Many studies have since used gene expression analysis at both the transcriptomic and proteomic levels to determine the effects of drugs, oxidants, and growth conditions on the global patterns of gene expression. Ultimately, the final response of these changes is reflected in the metabolic composition of the bacterium including a few thousand small molecular weight chemicals. Comparing the metabolic profiles of wild type and mutant strains, either untreated or treated with a particular drug, can effectively allow target identification and may lead to the development of novel inhibitors with anti-tubercular activity. Likewise, the effects of two or more conditions on the metabolome can also be assessed. Nuclear magnetic resonance (NMR) is a powerful technology that is used to identify and quantify metabolic intermediates. In this protocol, procedures for the preparation of M. tuberculosis cell extracts for NMR metabolomic analysis are described. Cell cultures are grown under appropriate conditions and required Biosafety Level 3 containment,1 harvested, and subjected to mechanical lysis while maintaining cold temperatures to maximize preservation of metabolites. Cell lysates are recovered, filtered sterilized, and stored at ultra-low temperatures. Aliquots from these cell extracts are plated on Middlebrook 7H9 agar for colony-forming units to verify absence of viable cells. Upon two months of incubation at 37 &deg;C, if no viable colonies are observed, samples are removed from the containment facility for downstream processing. Extracts are lyophilized, resuspended in deuterated buffer and injected in the NMR instrument, capturing spectroscopic data that is then subjected to statistical analysis. The procedures described can be applied for both one-dimensional (1D) 1H NMR and two-dimensional (2D) 1H-13C NMR analyses. This methodology provides more reliable small molecular weight metabolite identification and more reliable and sensitive quantitative analyses of cell extract metabolic compositions than chromatographic methods. Variations of the procedure described following the cell lysis step can also be adapted for parallel proteomic analysis.

Sample Preparation of Mycobacterium tuberculosis Extracts for Nuclear Magnetic Resonance Metabolomic Studies

The metabolomic profile of Mycobacterium tuberculosis is determined after growth in broth cultures. Conditions can be varied to test the effects of nutritional supplements, oxidants, and anti-tuberculosis agents on the metabolic profile of this microorganism. Procedure for extract preparation is applicable for both 1D 1H and 2D 1H-13C NMR analyses.

Preparação de amostras de<em&gt; Mycobacterium tuberculosis</em&gt; Extractos para Estudos Nucleares metabolômica Ressonância Magnética

Mycobacterium tuberculosis is a major cause of mortality in human beings on a global scale. The emergence of both multi- (MDR) and extensively-(XDR) ...

An Experimental Model to Study Tuberculosis-Malaria Coinfection upon Natural Transmission of Mycobacterium tuberculosis and Plasmodium berghei

Coinfections naturally occur due to the geographic overlap of distinct types of pathogenic organisms. Concurrent infections most likely modulate the respective immune response to each single pathogen and may thereby affect pathogenesis and disease outcome. Coinfected patients may also respond differentially to anti-infective interventions. Coinfection between tuberculosis as caused by mycobacteria and the malaria parasite Plasmodium, both of which are coendemic in many parts of sub-Saharan Africa, has not been studied in detail. In order to approach the challenging but scientifically and clinically highly relevant question how malaria-tuberculosis coinfection modulate host immunity and the course of each disease, we established an experimental mouse model that allows us to dissect the elicited immune responses to both pathogens in the coinfected host. Of note, in order to most precisely mimic naturally acquired human infections, we perform experimental infections of mice with both pathogens by their natural routes of infection, i.e. aerosol and mosquito bite, respectively.

An Experimental Model to Study Tuberculosis-Malaria Coinfection upon Natural Transmission of Mycobacterium tuberculosis and Plasmodium berghei

Tuberculosis and malaria are two of the most prevalent infections in humans and major causes of morbidity and mortality in impoverished populations in the tropics. We established an experimental model system to study outcome of malaria-tuberculosis coinfection in mice after challenge with both pathogens via their natural route of infection.

Um modelo experimental para estudar a Tuberculose-Malária Coinfection sobre Transmissão Natural de Mycobacterium tuberculosis E Plasmodium berghei</i

Coinfections naturally occur due to the geographic overlap of distinct types of pathogenic organisms. Concurrent infections most likely modulate the ...

Demonstrating a Multi-drug Resistant Mycobacterium tuberculosis Amplification Microarray

Simplifying microarray workflow is a necessary first step for creating MDR-TB microarray-based diagnostics that can be routinely used in lower-resource environments. An amplification microarray combines asymmetric PCR amplification, target size selection, target labeling, and microarray hybridization within a single solution and into a single microfluidic chamber. A batch processing method is demonstrated with a 9-plex asymmetric master mix and low-density gel element microarray for genotyping multi-drug resistant Mycobacterium tuberculosis (MDR-TB). The protocol described here can be completed in 6 hr and provide correct genotyping with at least 1,000 cell equivalents of genomic DNA. Incorporating on-chip wash steps is feasible, which will result in an entirely closed amplicon method and system. The extent of multiplexing with an amplification microarray is ultimately constrained by the number of primer pairs that can be combined into a single master mix and still achieve desired sensitivity and specificity performance metrics, rather than the number of probes that are immobilized on the array. Likewise, the total analysis time can be shortened or lengthened depending on the specific intended use, research question, and desired limits of detection. Nevertheless, the general approach significantly streamlines microarray workflow for the end user by reducing the number of manually intensive and time-consuming processing steps, and provides a simplified biochemical and microfluidic path for translating microarray-based diagnostics into routine clinical practice.

Demonstrating a Multi-drug Resistant Mycobacterium tuberculosis Amplification Microarray

An amplification microarray combines asymmetric PCR amplification and microarray hybridization into a single chamber, which significantly streamlines microarray workflow for the end user. Simplifying microarray workflow is a necessary first step for creating microarray-based diagnostics that can be routinely used in lower-resource environments.

Demonstrando um multi-resistente<em&gt; Mycobacterium tuberculosis</em&gt; Ampliação Microarray

Simplifying microarray workflow is a necessary first step for creating MDR-TB microarray-based diagnostics that can be routinely used in lower-resource ...

A Novel Microdissection Approach to Recovering Mycobacterium tuberculosis Specific Transcripts from Formalin Fixed Paraffin Embedded Lung Granulomas

Microdissection has been used for the examination of tissues at DNA, RNA, and protein levels for over a decade. Laser capture microscopy (LCM) is the most common microdissection technique used today. In this technique, a laser is used to focally melt a thermoplastic membrane that overlies a dehydrated tissue section1. The tissue section composite is then lifted and separated from the membrane. Although this technique can be used successfully for tissue examination, it is time consuming and expensive. Furthermore, the successful completion of procedures using this technique requires the use of a laser, thus limiting its use. A new more affordable and practical microdissection approach called mesodissection is a possible solution to the pitfalls of LCM. This technique employs the MESO-1/MeSectr system to mill the desired tissue from a slide mounted tissue sample while concurrently dispensing and aspirating fluid to recover the desired tissue sample into a consumable mill bit. Before the dissection process begins, the user aligns the formalin fixed paraffin embedded (FFPE) slide with a hematoxylin and eosin stained (H&#38;E) reference slide. Thereafter, the operator annotates the desired dissection area and proceeds to dissect the appropriate segment. The program generates an archived image of the dissection. The main advantage of mesodissection is the short duration needed to dissect a slide, taking an average of ten minutes from set up to sample generation in this experiment. Additionally, the system is significantly more cost effective and user friendly. A slight disadvantage is that it is not as precise as laser capture microscopy. In this article we demonstrate how mesodissection can be used to extract RNA from slides from FFPE granulomas caused by Mycobacterium tuberculosis (Mtb).

A Novel Microdissection Approach to Recovering Mycobacterium tuberculosis Specific Transcripts from Formalin Fixed Paraffin Embedded Lung Granulomas

Microdissection has been extensively employed for the examination of DNA, RNA, and protein within tissue. Laser capture microscopy (LCM) is the most commonly used method, but a new milling technique, mesodissection, is recently available. We demonstrate RNA extraction from mesodissected formalin fixed paraffin embedded tissue slides of Mycobacterium tuberculosis granulomas.

Uma nova abordagem para Microdissecção Recuperando<em&gt; Mycobacterium tuberculosis</em&gt; transcritos específicos de formalina fixo Parafina incorporado Lung granulomas

Microdissection has been used for the examination of tissues at DNA, RNA, and protein levels for over a decade. Laser capture microscopy (LCM) is the most ...

A 3D Human Lung Tissue Model for Functional Studies on Mycobacterium tuberculosis Infection

Tuberculosis (TB) still holds a major threat to the health of people worldwide, and there is a need for cost-efficient but reliable models to help us understand the disease mechanisms and advance the discoveries of new treatment options. In vitro cell cultures of monolayers or co-cultures lack the three-dimensional (3D) environment and tissue responses. Herein, we describe an innovative in vitro model of a human lung tissue, which holds promise to be an effective tool for studying the complex events that occur during infection with Mycobacterium tuberculosis (M. tuberculosis). The 3D tissue model consists of tissue-specific epithelial cells and fibroblasts, which are cultured in a matrix of collagen on top of a porous membrane. Upon air exposure, the epithelial cells stratify and secrete mucus at the apical side. By introducing human primary macrophages infected with M. tuberculosis to the tissue model, we have shown that immune cells migrate into the infected-tissue and form early stages of TB granuloma. These structures recapitulate the distinct feature of human TB, the granuloma, which is fundamentally different or not commonly observed in widely used experimental animal models. This organotypic culture method enables the 3D visualization and robust quantitative analysis that provides pivotal information on spatial and temporal features of host cell-pathogen interactions. Taken together, the lung tissue model provides a physiologically relevant tissue micro-environment for studies on TB. Thus, the lung tissue model has potential implications for both basic mechanistic and applied studies. Importantly, the model allows addition or manipulation of individual cell types, which thereby widens its use for modelling a variety of infectious diseases that affect the lungs.

A 3D Human Lung Tissue Model for Functional Studies on Mycobacterium tuberculosis Infection

Human tuberculosis infection is a complex process, which is difficult to model in vitro. Here we describe a novel 3D human lung tissue model that recapitulates the dynamics that occur during infection, including the migration of immune cells and early granuloma formation in a physiological environment.

Um modelo de tecido Pulmão humano 3D para estudos funcionais em<em&gt; Mycobacterium tuberculosis</em&gt; Infecção

Tuberculosis (TB) still holds a major threat to the health of people worldwide, and there is a need for cost-efficient but reliable models to help us ...

Ratiometric Imaging of Extracellular pH in Dental Biofilms

The pH in bacterial biofilms on teeth is of central importance for dental caries, a disease with a high worldwide prevalence. Nutrients and metabolites are not distributed evenly in dental biofilms. A complex interplay of sorption to and reaction with organic matter in the biofilm reduces the diffusion paths of solutes and creates steep gradients of reactive molecules, including organic acids, across the biofilm. Quantitative fluorescent microscopic methods, such as fluorescence life time imaging or pH ratiometry, can be employed to visualize pH in different microenvironments of dental biofilms. pH ratiometry exploits a pH-dependent shift in the fluorescent emission of pH-sensitive dyes. Calculation of the emission ratio at two different wavelengths allows determining local pH in microscopic images, irrespective of the concentration of the dye. Contrary to microelectrodes the technique allows monitoring both vertical and horizontal pH gradients in real-time without mechanically disturbing the biofilm. However, care must be taken to differentiate accurately between extra- and intracellular compartments of the biofilm. Here, the ratiometric dye, seminaphthorhodafluor-4F 5-(and-6) carboxylic acid (C-SNARF-4) is employed to monitor extracellular pH in in vivo grown dental biofilms of unknown species composition. Upon exposure to glucose the dye is up-concentrated inside all bacterial cells in the biofilms; it is thus used both as a universal bacterial stain and as a marker of extracellular pH. After confocal microscopic image acquisition, the bacterial biomass is removed from all pictures using digital image analysis software, which permits to exclusively calculate extracellular pH. pH ratiometry with the ratiometric dye is well-suited to study extracellular pH in thin biofilms of up to 75 &#181;m thickness, but is limited to the pH range between 4.5 and 7.0.

A pH-sensitive ratiometric dye is used in combination with confocal laser scanning microscopy and digital image analysis to monitor extracellular pH in dental biofilms in real-time.

Imagem raciométrica de pH extracelular no biofilme dentário

The pH in bacterial biofilms on teeth is of central importance for dental caries, a disease with a high worldwide prevalence. Nutrients and metabolites ...

System for Efficacy and Cytotoxicity Screening of Inhibitors Targeting Intracellular Mycobacterium tuberculosis

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is a leading cause of morbidity and mortality worldwide. With the increased spread of multi drug-resistant TB (MDR-TB), there is a real urgency to develop new therapeutic strategies against M. tuberculosis infections. Traditionally, compounds are evaluated based on their antibacterial activity under in vitro growth conditions in broth; however, results are often misleading for intracellular pathogens like M. tuberculosis since in-broth phenotypic screening conditions are significantly different from the actual disease conditions within the human body. Screening for inhibitors that work inside macrophages has been traditionally difficult due to the complexity, variability in infection, and slow replication rate of M. tuberculosis. In this study, we report a new approach to rapidly assess the effectiveness of compounds on the viability of M. tuberculosis in a macrophage infection model. Using a combination of a cytotoxicity assay and an in-broth M. tuberculosis viability assay, we were able to create a screening system that generates a comprehensive analysis of compounds of interest. This system is capable of producing quantitative data at a low cost that is within reach of most labs and yet is highly scalable to fit large industrial settings.

System for Efficacy and Cytotoxicity Screening of Inhibitors Targeting Intracellular Mycobacterium tuberculosis

We have developed a modular high-throughput screening system for discovering novel compounds against Mycobacterium tuberculosis, targeting intracellular and in-broth growing bacteria as well as cytotoxicity against the mammalian host cell.

Sistema de Eficácia e citotoxicidade Rastreio de inibidores Segmentação intracelular<em&gt; Mycobacterium tuberculosis</em

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is a leading cause of morbidity and mortality worldwide. With the increased spread ...

A High-throughput Compatible Assay to Evaluate Drug Efficacy against Macrophage Passaged Mycobacterium tuberculosis

The early drug development process for anti-tuberculosis drugs is hindered by the inefficient translation of compounds with in vitro activity to effectiveness in the clinical setting. This is likely due to a lack of consideration for the physiologically relevant cellular penetration barriers that exist in the infected host. We recently established an alternative infection model that generates large macrophage aggregate structures containing densely packed M. tuberculosis (Mtb) at its core, which was suitable for drug susceptibility testing. This infection model is inexpensive, rapid, and most importantly BSL-2 compatible. Here, we describe the experimental procedures to generate Mtb/macrophage aggregate structures that would produce macrophage-passaged Mtb for drug susceptibility testing. In particular, we demonstrate how this infection system could be directly adapted to the 96-well plate format showing throughput capability for the screening of compound libraries against Mtb. Overall, this assay is a valuable addition to the currently available Mtb drug discovery toolbox due to its simplicity, cost effectiveness, and scalability.

A High-throughput Compatible Assay to Evaluate Drug Efficacy against Macrophage Passaged Mycobacterium tuberculosis

New models and assays that would improve the early drug development process for next-generation anti-tuberculosis drugs are highly desirable. Here, we describe a quick, inexpensive, and BSL-2 compatible assay to evaluate drug efficacy against Mycobacterium tuberculosis that can be easily adapted for high-throughput screening.

Um ensaio Compatível de alta capacidade para avaliar droga Eficácia contra macrófagos passadas<em&gt; Mycobacterium tuberculosis</em

The early drug development process for anti-tuberculosis drugs is hindered by the inefficient translation of compounds with in vitro activity to ...

Analysis of 18FDG PET/CT Imaging as a Tool for Studying Mycobacterium tuberculosis Infection and Treatment in Non-human Primates

Mycobacterium tuberculosis remains the number one infectious agent in the world today. With the emergence of antibiotic resistant strains, new clinically relevant methods are needed that evaluate the disease process and screen for potential antibiotic and vaccine treatments. Positron Emission Tomography/Computed Tomography (PET/CT) has been established as a valuable tool for studying a number of afflictions such as cancer, Alzheimer&#39;s disease, and inflammation/infection. Outlined here are a number of strategies that have been employed to evaluate PET/CT images in cynomolgus macaques that are infected intrabronchially with low doses of M. tuberculosis. Through evaluation of lesion size on CT and uptake of 18F-fluorodeoxyglucose (FDG) in lesions and lymph nodes in PET images, these described methods show that PET/CT imaging can predict future development of active versus latent disease and the propensity for reactivation from a latent state of infection. Additionally, by analyzing the overall level of lung inflammation, these methods determine antibiotic efficacy of drugs against M. tuberculosis in the most clinically relevant existing animal model. These image analysis methods are some of the most powerful tools in the arsenal against this disease as not only can they evaluate a number of characteristics of infection and drug treatment, but they are also directly translatable to a clinical setting for use in human studies.

Analysis of 18FDG PET/CT Imaging as a Tool for Studying Mycobacterium tuberculosis Infection and Treatment in Non-human Primates

Here, we present a protocol to describe the analysis of 18F-FDG PET/CT imaging in non-human primates that have been infected with M. tuberculosis to study disease process, drug treatment, and disease reactivation.

Análise de 18FDG PET-CT Imaging como uma ferramenta para estudar infecção por Mycobacterium tuberculosis e tratamento em primatas não-humanos

Mycobacterium tuberculosis remains the number one infectious agent in the world today. With the emergence of antibiotic resistant strains, new clinically ...