El trabajo se llevó a cabo con el apoyo financiero del Instituto Nacional de Salud y Asociación Americana del Pulmón.

1. Biopelículas de crecimiento de M. la tuberculosis en una botella de 250 ml con tapa rosca <ol><li> Preparación de medios de comunicación: Disolver 0,5 g de KH 2 PO 4, 0,5 g de MgSO 4, 4 g de L-asparagina, 2 g de ácido cítrico, 0,05 g de citrato férrico amónico, 60 ml de glicerol en 900 ml de agua. Ajustar el pH a 7,0 con NaOH. Autoclave, enfriar y justo antes de iniciar el experimento, añadir estéril ZnSO 4 a una concentración final de 0,1% w / v Desde 7000 mc 2 es un auxótrofo pantotenato de esta cepa también requiere que el ácido pantoténico en 10μg/mL de la concentración final. </li></ol> Nota: Esta es una composición estándar de los medios de comunicación Sauton utilizados para M. tuberculosis. Sin embargo, si se requiere otros medios especializados también se puede utilizar para otras especies de micobacterias. <ol start="2"><li> Preparación de inóculo: Crecer M. la tuberculosis en 7H9OADC con 0,05% de Tween-80 durante una semana, o 600 OD de 0,7 a 1,0. La culture puede ser utilizado directamente como inóculo a una dilución 1:100. </li><li> Dispense 25 ml de medios de Sauton a una botella de 250 ml tapado de rosca de poliestireno (Corning). Añadir 250μl del inóculo en el medio, la tapa de la botella muy bien y colocarla sin problemas en un humidificado incubadora a 37 ° C durante 3 semanas. Observar la botella una vez cada día para asegurar que no hay contaminación. </li><li> Al final de la tercera semana, aflojar el tapón de la botella para permitir un mayor crecimiento de M. la tuberculosis en la interfaz. Si el tapón no se afloja en esta etapa a continuación, la concentración de oxígeno insuficiente en el contenedor retardar el crecimiento adicional de las bacterias. </li></ol> 2. Crecimiento de M. biopelículas de tuberculosis en placas de 12 pocillos <ol><li> Preparar los medios de comunicación y el inóculo de 7.000 mc 2, como se describe en las secciones A1 y ​​A2. </li><li> Mezclar 60 ml de medios de comunicación con 600μl de inóculo. Dispense 4,5 millonesL de la mezcla en cada pocillo de la placa. Cubrir la placa con la tapa. Envuelva la placa varias veces con Parafilm. Se incuba la placa sin perturbaciones en incubador humidificado a 37 ° C durante 5 semanas. </li></ol> 3. Determinar la frecuencia de las drogas persisters tolerantes en M. la tuberculosis biopelículas <ol><li> Crecer M. biopelículas de tuberculosis en un formato de 12, así como se describe en la sección B. Esto tomará un total de alrededor de 5 semanas. </li><li> Una vez que las biopelículas son madurados (después de 5 semanas de incubación) debe inyectar la elección del antibiótico a la concentración deseada en los medios de comunicación por debajo de las biopelículas utilizando un micropunta en una pipeta. </li></ol> Nota: El volumen de los medios de debajo de las unas películas reduce a aproximadamente 3,0 ml. Así que los investigadores en consecuencia debe calcular la cantidad de droga. <ol start="3"><li> Agitar la placa suavemente de modo que el antibiótico se difunde a fondo en el medio. Para obtener resultados estadísticamente significativos, se inyectan antibióticos de laótico en cuatro pocillos. En paralelo, inyectar el mismo volumen de disolvente en el que se disolvió el antibiótico en otros cuatro pocillos, y dejar los últimos cuatro pocillos de la placa sin tocar. Cubrir la placa con la tapa y poner nuevas capas de parafina alrededor de la placa. Coloque de nuevo en la incubadora por un período de tiempo deseado. </li><li> Al final de la incubación, abrir la placa y añadir Tween-80 a la concentración final de 0,1% (volumen / volumen) en cada uno de los pocillos. Agitar la placa suavemente durante toda la dispersión uniforme del detergente. Se incuba la placa a temperatura ambiente durante 15 minutos. Mezclar el contenido de cada pocillo con pipeta varias veces para que el contenido entero puede ser uniformemente transferidos a un tubo cónico de 15 ml. </li><li> Centrifugar el contenido del tubo en 4000rpm durante 10 minutos a temperatura ambiente. Resuspender el sedimento en 5 ml de tampón de lavado fresco (PBS con 10% de glicerol y 0,05% de Tween-80). Repetir las lavado tres veces. Resuspender el precipitado en 5 ml de tampón de lavado. Manténgalo en el eje de balancín para la overnight a 4 ° C. </li></ol> Nota: A pesar de la baja temperatura se desarrolló originalmente para M. smegmatis (para minimizar su crecimiento durante la dispersión) y se utiliza para M. tuberculosis, así, las especies de crecimiento lento puede ser más probable es que sacudió a temperatura ambiente sin ningún tipo de impacto en el resultado. Mecedora a temperatura ambiente, puede ser necesario si se trabaja en las instalaciones BSL-3. <ol start="6"><li> Preparar una jeringa estéril equipado con micropunta (2-200μl) mediante la reducción de su extremo más ancho al tamaño adecuado, ajustándolo a la jeringa y envolviéndolo con parafilm. Pasar todo el contenido del tubo a través de la jeringa con punta equipada y recoger en tubos de 15 ml unos frescos. Repita este paso de 5 a 6 veces hasta que se observa una suspensión bastante homogénea. </li><li> Preparar diluciones seriadas de la suspensión y la placa de las diluciones en la placa 7H11OADC para determinar el número de colonias viables en cada pocillo. Las placas se incuban durante tres semanas a 37 ° C incubadora. Determinar la frecuenciascy de persisters en la población biopelícula mediante el cálculo de la relación del número de colonias obtenidas en tratado con antibióticos a los obtenidos en disolventes placas tratadas. </li></ol> 4. Los resultados representativos Cuando se cultiva en una botella, el crecimiento de M. la tuberculosis se puede ver en la base de la botella por el final de la primera semana. Al final de la segunda semana, el crecimiento irregular de bacterias en la interfase aire-medio puede verse, aunque el crecimiento en la interfase aire-medio es constantemente visible al final de la tercera semana (fig. 1A). En este momento la fijación de las bacterias a la pared del recipiente también se observa. A partir de este punto, el crecimiento del cultivo se produce principalmente en la interfase aire-medio. El líquido debajo de la superficie de crecimiento es clara. Típicamente, la estructura madura para el final de la quinta semana (Fig. 1B). Si incubación es prolongado, las estructuras comenzará a hundirse hasta el fondo del recipiente. Curiosamente,apriete de la tapa hasta el final de la tercera semana es un paso importante en el proceso, y por razones desconocidas una botella con tapón suelto significativamente retarda la iniciación del crecimiento en la interfaz 9. En el formato de 12-así, una biopelícula robusta en la interfase aire-medio se ve en cada uno de los pocillos al final de cinco semanas (Fig. 2A). Si las placas no están protegidos por completo entonces, el crecimiento diferencial de la biopelícula que se observa. En el peor de los casos, la evaporación significativa de los medios pueden detener el crecimiento de las bacterias (Fig. 2B). Así, la envoltura de la placa es necesario tanto para evitar la evaporación, así como para proporcionar el medio ambiente para la formación de biopelículas (véase el párrafo anterior). El número de bacilos viables en las biopelículas determinados con esta técnica es muy reproducible. Respuesta de M. tuberculosis biopelículas varía con la naturaleza de los antibióticos. Para un antibiótico bactericida como la rifampicina, la pérdida de viabilidad sigue una bipha<html> sic tendencia 9. Una rápida disminución de la viabilidad durante las primeras tres a cuatro días, seguido de una fase persistente en el que un pequeño porcentaje de la población permanecen completamente recalcitrante a los antibióticos, independientemente de la concentración del antibiótico o el tiempo de exposición. La Figura 3 muestra el número de bacilos viables en las biopelículas maduras después de una exposición 7-días a 50μg/mL (50 veces más alta que la CIM) de rifampicina. <img alt="Figura 1A." src="/files/ftp_upload/3820/3820fig1A.jpg" /> Figura 1. Aparición temprana de M. bacilos de la tuberculosis de la interfase aire-los medios de comunicación de las bacterias después de 3 semanas de incubación. <img alt="Figura 1B." src="/files/ftp_upload/3820/3820fig1B.jpg" /> Figura 1B. Madurado biopelículas de M. tuberculosis en la interfase aire-medio después de cinco semanas de incubación. 820/3820fig2A.jpg &quot;/&gt; Figura 2A. De 5 semanas de edad las biopelículas de M. la tuberculosis crece en 12 y en formato. <img alt="Figura 2B." src="/files/ftp_upload/3820/3820fig2B.jpg" /> Figura 2B. Un intento fallido para crecer M. tuberculosis en las biopelículas de 12 pocillos, sin parafina. <img alt="Figura 3." src="/files/ftp_upload/3820/3820fig3.jpg" /> Figura 3. Un gráfico representativo que muestra la frecuencia de persisters drogas tolerantes en M. tuberculosis biopelículas crecido en 12-así formato y expuestos a 50μg/mL de rifampicina durante siete días.

<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>

No tenemos nada que revelar.

La tuberculosis (TB), causada por la infección de Mycobacterium tuberculosis, sigue siendo una gran amenaza para la salud pública mundial. Casi un tercio de la población mundial se estima que se forma asintomática infectada por el patógeno, cerca de 9 millones de nuevos casos aparecen en la clínica todos los años con síntomas de tuberculosis activa y alrededor de 1,7 millones de personas mueren de la infección todos los años 11. El enorme peso de la enfermedad es principalmente aportados po...

<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, el agente etiológico de la tuberculosis humana, tiene una extraordinaria capacidad para sobrevivir a las tensiones ambientales, incluidos los antibióticos. A pesar de la tolerancia al estrés de M. la tuberculosis es uno de los probables contribuyentes a la quimioterapia de largo de 6 meses de la tuberculosis 1, los mecanismos moleculares que subyacen a este fenotipo característico del patógeno siguen sin estar claros. Muchas de las especies microbianas han evolucionado para sobrevivir en ambientes estresantes auto-montaje en el altamente organizado, de superficie unida, y las estructuras matriciales encapsulados denominadas biofilms 2-4. El crecimiento de las comunidades parece ser una estrategia de supervivencia preferente de los microbios, y se logra a través de los componentes genéticos que regulan la fijación de superficie, la comunicación intercelular, y la síntesis de sustancias poliméricas extracelulares (EPS) 5,6. La tolerancia al estrés ambiental es probablemente facilitado por EPS, y tal vez por el physiolola adaptación lógica de bacilos individuo a microambientes heterogéneos dentro de la compleja arquitectura de las biopelículas 7. En una serie de trabajos recientes se estableció que el señor la tuberculosis y Mycobacterium smegmatis tienen una fuerte tendencia a crecer en estructuras multicelulares organizados, llamados biofilms, que pueden tolerar más de 50 veces la concentración mínima inhibitoria de los medicamentos antituberculosos isoniazida y la rifampicina 10.08. M. la tuberculosis, sin embargo, curiosamente requiere condiciones específicas para formar biofilms maduros, en particular, relación 9:1 de espacio de cabeza: los medios de comunicación, así como el escaso intercambio de aire con la atmósfera 9. Requisitos de las condiciones ambientales especializados, posiblemente, podría estar relacionado con el hecho de que M. la tuberculosis es un patógeno humano obliga y por lo tanto se ha adaptado a los ambientes del tejido. En esta publicación se demuestra métodos para el cultivo de M. tuberculosisbiopelículas en una botella y un formato de placa de 12 pocillos, que es conveniente para los estudios bacteriológicos, así como genéticos. Hemos descrito el protocolo para una cepa atenuada de M. la tuberculosis, el mc 2 7000, con la supresión de los dos loci, PANCD y la RD1, que son fundamentales para el crecimiento in vivo del patógeno 9. Esta cepa puede ser utilizado con seguridad en una contención BSL-2 para la comprensión de la biología básica del patógeno de la tuberculosis evitando así la exigencia de una costosa instalación de BSL-3. El método puede ser extendido, con las modificaciones apropiadas en los medios de comunicación, para crecer biofilm de otras especies de micobacterias cultivables. En general, un protocolo uniforme de las biopelículas de cultivo de micobacterias ayudará a los investigadores interesados ​​en estudiar las características básicas de las micobacterias resistentes. Además, un método claro y conciso de las biopelículas de crecimiento de micobacterias también ayudará a la inv clínica y farmacéuticaestigators para probar la eficacia de un fármaco potencial.

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

Growth of Mycobacterium tuberculosis Biofilms

Mycobacterium tuberculosis forma biofilms de drogas tolerantes cuando se cultivan en ciertas condiciones. Aquí se describen los métodos para el cultivo de M. biopelículas la tuberculosis y la determinación de la frecuencia de las drogas persisters tolerantes. Estos protocolos serán útiles para futuros estudios sobre los mecanismos de tolerancia a las drogas en M. la tuberculosis.

Crecimiento de Mycobacterium tuberculosis Las biopelículas

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 vistas.  University of Pittsburgh. Mycobacterium tuberculosis forma biofilms de drogas tolerantes cuando se cultivan en ciertas condiciones. Aquí se describen los métodos para el cultivo de M. biopelículas la tuberculosis y la determinación de la frecuencia de las drogas persisters tolerantes. Estos protocolos serán útiles para futuros estudios sobre los mecanismos de tolerancia a las drogas en M. la tuberculosis.

Video: 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.

Pruebas de susceptibilidad antimicrobiana de Mycobacterium tuberculosis complex para drogas de primera línea y la segunda por dilución en caldo en un formato de placa de microtitulación

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

Investigación

Inmunología e Infección

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.

Preparación de la muestra de<em&gt; Mycobacterium tuberculosis</em&gt; Extractos de Estudios de Resonancia Magnética Nuclear metabolómica

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.

Un modelo experimental para estudiar la tuberculosis-Malaria Coinfección sobre Transmisión Natural de Mycobacterium tuberculosis Y 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.

Demostración de un resistente a múltiples fármacos<em&gt; Mycobacterium tuberculosis</em&gt; Microarray Amplificación

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.

Un nuevo enfoque para la recuperación Microdissection<em&gt; Mycobacterium tuberculosis</em&gt; Las transcripciones específicas de formalina parafina fijo Embedded pulmón 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.

Un modelo de tejido 3D Pulmón humano de Estudios funcionales en<em&gt; Mycobacterium tuberculosis</em&gt; Infección

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.

Imaging radiométrica de pH extracelular en los biofilms dentales

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 para la eficacia y la citotoxicidad de detección de inhibidores de focalización 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.

Un ensayo compatible de alto rendimiento para evaluar la eficacia del fármaco contra los macrófagos a pases<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.

Análisis de 18FDG PET/CT la proyección de imagen como una herramienta para estudiar la tuberculosis del Mycobacterium infección y tratamiento en Primates no humanos

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