Name: conjunctival commensal isolation and identification in mice
Uploaded: 2021-05-01T13:00:00
Description: Watch this Scientific Journal Video about Conjunctival Commensal Isolation and Identification in Mice at JoVE.com

El financiamiento de P30 DK034854 apoyó VY, LB y estudios en el Massachusetts Host-Microbiome Center y el financiamiento de NIH / NEI R01 EY022054 apoyó MG.

Todos los procedimientos que involucran ratones siguen las pautas del Comité Institucional de Cuidado y Uso de Animales. Siga las pautas de seguridad del laboratorio (según las indicaciones de su departamento institucional de salud y seguridad ambiental) cuando trabaje con microorganismos y materiales potencialmente contaminados. Utilice recipientes de desecho apropiados y procedimientos de descontaminación antes de la eliminación de materiales contaminados potencialmente peligrosos.
1. Prep...

<ol>
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E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ocular+pathogen+or+commensal:+a+PCR+based+study+of+surface+bacterial+flora+in+normal+and+dry+eyes.">Ocular pathogen or commensal: a PCR based study of surface bacterial flora in normal and dry eyes.</a> Investigative Ophthalmology and Visual Science. 48 (12), 5616-5623 (2007).</li><li>Wang, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sj&#246;gren-Like+Lacrimal+Keratoconjunctivitis+in+Germ-Free+Mice.">Sj&#246;gren-Like Lacrimal Keratoconjunctivitis in Germ-Free Mice.</a> International Journal of Molecular Sciences. 19 (2), 565-584 (2018).</li><li>Ham, B., Hwang, H. B., Jung, S. H., Chang, S., Kang, K. D., Kwon, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distribution+and+diversity+of+ocular+microbial+communities+in+diabetic+patients+compared+with+healthy+subjects.">Distribution and diversity of ocular microbial communities in diabetic patients compared with healthy subjects.</a> Current Eye Research. 43 (3), 314-324 (2018).</li><li>Doan, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Paucibacterial+microbiome+and+resident+DNA+virome+of+the+healthy+conjunctiva.">Paucibacterial microbiome and resident DNA virome of the healthy conjunctiva.</a> Investigative Ophthalmology and Visual Science. 57 (13), 5116-5126 (2016).</li><li>Kugadas, A., Gadjeva, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+microbiome+on+ocular+health.">Impact of microbiome on ocular health.</a> Ocular Surface. 14 (3), 342-349 (2016).</li><li>Dong, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diversity+of+bacteria+at+healthy+human+conjunctiva.">Diversity of bacteria at healthy human conjunctiva.</a> Investigative Ophthalmology and Visual Science. 53 (8), 5408-5413 (2011).</li><li>Zegans, M. 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M., Efron, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microbial+flora+in+eyes+of+current+and+former+contact+lens+wearers.">Microbial flora in eyes of current and former contact lens wearers.</a> Journal of Clinical Microbiology. 30 (5), 1156-1161 (1992).</li><li>Lu, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neutrophil+L-Plastin+Controls+Ocular+Paucibacteriality+and+Susceptibility+to+Keratitis.">Neutrophil L-Plastin Controls Ocular Paucibacteriality and Susceptibility to Keratitis.</a> Frontiers in Immunology. 11, 547 (2020).</li><li>Johnson, T. R., Case, C. 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J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=IL-1R+and+MyD88+contribute+to+the+absence+of+a+bacterial+microbiome+on+the+healthy+murine+cornea.">IL-1R and MyD88 contribute to the absence of a bacterial microbiome on the healthy murine cornea.</a> Frontiers in Microbiology. 9, 1117 (2018).</li><li>Ozkan, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal+Stability+and+Composition+of+the+Ocular+Surface+Microbiome.">Temporal Stability and Composition of the Ocular Surface Microbiome.</a> Scientific Reports. 7 (1), 9880 (2017).</li><li>Oliver, J. 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B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxic+effect+of+calcium+alginate+swabs+on+Neisseria+gonorrhoeae.">Toxic effect of calcium alginate swabs on Neisseria gonorrhoeae.</a> Journal of Clinical Microbiology. 26 (1), 54-56 (1988).</li><li>Dubois, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Performances+of+the+Vitek+MS+matrix-assisted+laser+desorption+ionization-time+of+flight+mass+spectrometry+system+for+rapid+identification+of+bacteria+in+routine+clinical+microbiology.">Performances of the Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry system for rapid identification of bacteria in routine clinical microbiology.</a> Journal of Clinical Microbiology. 50 (8), 2568-2576 (2012).</li><li>Kawakita, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=double-blind+study+of+the+safety+and+Efficacy+of+1%D-3-Hydroxybutyrate+eye+drops+for+Dry+Eye+Disease.">double-blind study of the safety and Efficacy of 1%D-3-Hydroxybutyrate eye drops for Dry Eye Disease.</a> Scientific Reports. 6, 20855 (2016).</li><li>Lee, H. 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S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inflammatory+response+to+lipopolysaccharide+on+the+ocular+surface+in+a+murine+dry+eye+model.">Inflammatory response to lipopolysaccharide on the ocular surface in a murine dry eye model.</a> Investigative Ophthalmology and Visual Science. 57 (6), 2444-2450 (2016).</li><li>Miller, D., Ioviano, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+microbial+flora+on+the+ocular+surface.">The role of microbial flora on the ocular surface.</a> Current Opinion in Allergy and Immunology. 9 (5), 466-470 (2009).</li><li>Nayyar, A., Gindina, S., Barron, A., Hu, Y., Danias, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Do+epigenetic+changes+caused+by+commensal+microbiota+contribute+to+development+of+ocular+disease?+A+review+of+evidence.">Do epigenetic changes caused by commensal microbiota contribute to development of ocular disease? A review of evidence.</a> Human Genomics. 14 (1), 11 (2020).</li><li>Stevenson, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dry+eye+disease:+an+immune-mediated+ocular+surface+disorder.">Dry eye disease: an immune-mediated ocular surface disorder.</a> Archives of Ophthalmology. 130 (1), 90-100 (2012).</li></ol>

Debido al estado paucibacteriano de la superficie ocular, muchos laboratorios han tenido dificultades para aislar los comensales oculares7,20,resultando en un bajo número de muestras con crecimiento, baja abundancia y baja diversidad8. Este método mejora significativamente las prácticas de cultivo estándar4,21 mediante la adición de un paso de enriquecimiento, así como un his...

El objetivo de este protocolo es aumentar el aislamiento específico de microbios anaeróbicos aeróbicos y facultativos viables y raros de la conjuntiva ocular para caracterizar el microbioma ocular. Amplios estudios han perfilado comunidades de la mucosa conmensal en la piel, intestino, vías respiratorias y genitales y muestran que estas comunidades influyen en el desarrollo del sistema inmune y la respuesta1,2,3. Se ha demostrado que las comunidades comensales oculares cambian durante ciertas patologías de la enfermedad, como la enfermedad del ojo seco4,el síndrome de Sjogren5 y la diabetes6. Sin embargo, la capacidad de definir una comunidad comensal de superficie ocular típica se ve obstaculizada por su abundancia relativamente baja en comparación con los otros sitios de la mucosa6,7,8. Esto provoca una controversia sobre si existe un microbioma ocular residente y si existe, si difiere del microbioma de la piel y, en consecuencia, su efecto local sobre el desarrollo y la respuesta del sistema inmune innato. Este protocolo puede ayudar a resolver esta pregunta.
En general, los enfoques para definir el nicho comensal ocular se basan en técnicas de secuenciación y cultivo4,7,9. La secuenciación del ADNr 16 S y el análisis BRISK7 muestran una diversidad más amplia que las técnicas basadas en la cultura, pero son incapaces de diferenciar entre microbios vivos y muertos. Dado que la superficie ocular es hostil a muchos microbios debido a las propiedades antimicrobianas de la película lagrimal4 que generan una gran variedad de fragmentos de ADN, los enfoques basados en adn detectarán estos artefactos que pueden sesgar los datos hacia la identificación de bacterias muertas como comensales residentes en lugar de contaminantes. Esto resulta en una aberrante identificación comensal y caracterización del espacio ocular como mayor en abundancia y diversidad de microbios10. Esto hace que sea difícil definir el microbioma ocular residente a través de métodos basados en el ADN. Mientras que, las técnicas estándar basadas en el cultivo no pueden detectar los contraensales porque la carga es demasiado baja11. Nuestro método mejora las prácticas estándar mediante el uso de un hisopo delgado que puede dirigirse a la conjuntiva, evitando así la contaminación de la piel vecina, así como el concepto de que los organismos viables pueden enriquecerse mediante un breve cultivo en medios densos en nutrientes con el objetivo de resucitar viables pero no cultivables, así como, enriquecer para microbios viables raros.
Los resultados, abundancia relativa de comensales oculares por hisopo ocular, caracterizan el microbioma residente de la conjuntiva y son importantes para fines comparativos. Nuestros datos muestran que hay una diferencia entre la piel y la microbiota conjuntival, así como una mayor diversidad con el aumento de la edad y una diferencia específica del sexo en la abundancia. Además, este enfoque ha encontrado de forma reproducible diferencias cómicas en ratones knock-out12. Este protocolo se puede aplicar para describir el microbioma ocular que puede variar debido a las prácticas de enjaulado, la geografía o el estado de la enfermedad, así como los efectos locales de los metabolitos y productos consal sobre el desarrollo y la respuesta del sistema inmunológico.

<table>
	<tbody>
		<tr>
			<td>0.1 to 10 &#181;l pipet tip</td>
			<td>USA Scientific</td>
			<td>1110-300</td>
			<td>autoclave before use</td>
		</tr>
		<tr>
			<td>0.5 to 10 &#181;l Eppendorf pipet</td>
			<td>Fisher Scientific</td>
			<td>13-690-026</td>
			<td></td>
		</tr>
		<tr>
			<td>1 ml syringe</td>
			<td>Fisher Scientific</td>
			<td>BD309623</td>
			<td>1 syringe for each eye swab group</td>
		</tr>
		<tr>
			<td>1.5 ml Eppendorf tubes</td>
			<td>USA Scientific</td>
			<td>1615-5500</td>
			<td>autoclave before use</td>
		</tr>
		<tr>
			<td>1000 &#181; ml pipet tip</td>
			<td>USA Scientific</td>
			<td>1111-2021</td>
			<td>autoclave before use</td>
		</tr>
		<tr>
			<td>200 to 1000&#181;l Gilson pipetman (P1000)</td>
			<td>Fisher Scientific</td>
			<td>F123602G</td>
			<td></td>
		</tr>
		<tr>
			<td>25 G needle</td>
			<td>Fisher Scientific</td>
			<td>14-826AA</td>
			<td>1 needle per eye swab group</td>
		</tr>
		<tr>
			<td>3 % Hydrogen Peroxide</td>
			<td>Fisher Scientific</td>
			<td>S25359</td>
			<td></td>
		</tr>
		<tr>
			<td>37 &#176; C Incubator</td>
			<td>Lab equipment</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>70 % Isopropanol</td>
			<td>Fisher Scientific</td>
			<td>PX1840-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Ana-Sed Injection (Xylazine 100 mg/ml)</td>
			<td>Santa Cruz Animal Health</td>
			<td>SC-362949Rx</td>
			<td></td>
		</tr>
		<tr>
			<td>BD BBL Gram Stain kit</td>
			<td>Fisher Scientific</td>
			<td>B12539</td>
			<td></td>
		</tr>
		<tr>
			<td>Bunsen Burner</td>
			<td>Lab equipment</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Clean paper towels</td>
			<td>Lab equipment</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cotton Batting/Sterile rolled cotton</td>
			<td>CVS</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable 1 ml Pipets</td>
			<td>Fisher Scientific</td>
			<td>13-711-9AM</td>
			<td>for Gram stain and catalase tests</td>
		</tr>
		<tr>
			<td>E.coli</td>
			<td>ATTC</td>
			<td>ATCC 8739</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass slides</td>
			<td>Fisher Scientific</td>
			<td>12-550-A3</td>
			<td>for Gram stain and catalase tests</td>
		</tr>
		<tr>
			<td>Ketamine (100mg/ml)</td>
			<td>Henry Schein</td>
			<td>9950001</td>
			<td></td>
		</tr>
		<tr>
			<td>Mac Conkey Agar Plates</td>
			<td>Fisher Scientific</td>
			<td>4321270</td>
			<td>store at 4 &#176;C until ready to use</td>
		</tr>
		<tr>
			<td>Mannitol Salt Agar</td>
			<td>Carolina Biological Supply</td>
			<td>784641</td>
			<td>Prepare plates according to mfr&#39;s instructions, store at 4 &#176;C for 1 week</td>
		</tr>
		<tr>
			<td>Mice</td>
			<td>Jackson Labs</td>
			<td>C57/BL6J</td>
			<td></td>
		</tr>
		<tr>
			<td>Petri Dishes</td>
			<td>Fisher Scientific</td>
			<td>08-757-12</td>
			<td>for Mannitol Salt agar plates</td>
		</tr>
		<tr>
			<td>RPI Brain Heart Infusion Media</td>
			<td>Fisher Scientific</td>
			<td>50-488525</td>
			<td>prepare according to directions and autoclave</td>
		</tr>
		<tr>
			<td>SteriFlip (0.22 &#181;m pore size polyester sulfone)</td>
			<td>EMD/Millipore, Fisher Scientifc</td>
			<td>SCGP00525</td>
			<td>to sterilize anesthesia</td>
		</tr>
		<tr>
			<td>Sterile Corning Centrifuge Tube</td>
			<td>Fisher Scientific</td>
			<td>430829</td>
			<td>anesthesia preparation</td>
		</tr>
		<tr>
			<td>Sterile mouse cage</td>
			<td>Lab equipment</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tooth picks (round bamboo)</td>
			<td>Kitchen Essentials</td>
			<td></td>
			<td>autoclave before use and swab preparation</td>
		</tr>
		<tr>
			<td>Trypticase Soy Agar II with 5% Sheep&#39;s Blood Plates</td>
			<td>Fisher Scientific</td>
			<td>4321261</td>
			<td>store at 4 &#176;C until ready to use</td>
		</tr>
		<tr>
			<td>Vitek target slide</td>
			<td>BioMerieux Inc. Durham,NC</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vitek-MS</td>
			<td>BioMerieux Inc. Durham,NC</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vitek-MS CHCA matrix solution</td>
			<td>BioMerieux Inc. Durham, NC</td>
			<td>411071</td>
			<td></td>
		</tr>
		<tr>
			<td>Single use eye drops</td>
			<td>CVS Pharmacy</td>
			<td></td>
			<td>Bausch and Lomb Soothe Lubricant Eye Drops, 28 vials, 0.02 fl oz. each</td>
		</tr>
	</tbody>
</table>

conjunctival commensal isolation and identification in mice

La superficie ocular era considerada una vez inmune privilegiada y abiótica, pero aparece recientemente que hay una presencia commensal pequeña, pero persistente. La identificación y la supervisión de las especies bacterianas en la mucosa ocular han sido desafiadoras debido a su abundancia baja y a la disponibilidad limitada de la metodología apropiada para el crecimiento y la identificación comensales. Hay dos enfoques estándar: métodos basados en el cultivo o métodos de secuenciación de ADN. El primer método es problemático debido a las bacterias recuperables limitadas y el segundo acercamiento identifica las bacterias vivas y muertas que llevan a una representación aberrante del espacio ocular. Desarrollamos un método robusto y sensible para el aislamiento bacteriano mediante el desarrollo de técnicas de cultivo microbiológico estándar. Esta es una técnica basada en hisopos, utilizando un hisopo delgado hecho "en el laboratorio" que se dirige a la conjuntiva inferior, seguido de un paso de amplificación para los géneros anaeróbicos aeróbicos y facultativos. Este protocolo nos ha permitido aislar e identificar especies conjuntivales como Corynebacterium spp., Coagulase Negative Staphylococcus spp., Streptococcus spp.,etc. El enfoque es adecuado para definir la diversidad commensal en ratones bajo diferentes condiciones de enfermedad.

Los resultados representativos de una placa de hisopo ocular que demuestran diferentes métodos para el revestimiento se muestran en la Figura 3A que muestra aislados morfológicamente diversos del ratón C57BL/6. Para cada aislante distinto, las colonias fueron contadas en la tira y la abundancia relativa, unidades formantes únicas de la colonia (CFUs) por la hisopo del ojo, calculadas y trazadas para los propósitos de la comparación. Para la caracterización microbiológica, las bacteri...

Watch this Scientific Journal Video about Conjunctival Commensal Isolation and Identification in Mice at JoVE.com

Conjunctival Commensal Isolation and Identification in Mice

Aquí se presenta un protocolo para el aislamiento y la amplificación de las bacterias conjuntivales anaerobias aeróbicas y facultativas del ratón usando una hisopo ocular única y un paso de enriquecimiento basado en la cultura con la identificación posterior por métodos basados microbiológicos y espectrometría de masas MALDI-TOF.

Aislamiento e identificación comensal conjuntival en ratones

The ocular surface was once considered immune privileged and abiotic, but recently it appears that there is a small, but persistent commensal presence. ...

Este método identifica los microorganismos conjuntivales oculares viables, que es desafiando debido al ambiente hostil de los ojos. Puede ayudar a responder si existe un microbioma ocular y cómo cambia la presencia bacteriana en la enfermedad ocular. En contraste con la secuenciación de ADN, que identifica microorganismos viables e inviables, este método identifica solo microorganismos viables, lo que resulta en una comprensión más clara de la comunidad comensal ocular.Los estudios sugieren que las enfermedades oculares difíciles de diagnosticar tales como ojo seco no autoinmune y autoinmune tengan presencia bacteriana ocular única. Este método se podía utilizar para diagnosticar enfermedades de ojo con las firmas microbianas distintivas. Comience por autoclave de la cantidad adecuada de bateo de algodón y palillos de dientes para el número de ratones a ser hisopados, a continuación, pellizcar 1/2 un centímetro de largo pedazo de algodón de bateo y burlarse tirando de los bordes para formar una sola capa porosa plana que se detiene justo antes de que el bateo se deshace.Gire el bateo alrededor de uno de los extremos afilados del palillo de dientes sosteniendo ligeramente la pieza estirada en la punta del palillo de dientes a medida que se tuerce. El hisopo de ojo terminado tendrá una capa muy delgada de algodón estirada sobre la punta que se extiende aproximadamente 1/2 a un centímetro de distancia de la punta. Inserte los hisopos en un pequeño casto, haga un hisopo lateral hacia abajo y luego cúbralos y autoclave.Limpie el área de trabajo con un desinfectante para minimizar la contaminación y alícuota 0.5 mililitros de infusión estéril de corazón cerebral, o medios BHI en tubos de microcentrifugación estériles etiquetados de 1.5 mililitros. Tapar los tubos en un rack y poner el rack en hielo. Configure el flujo de trabajo de izquierda a derecha comenzando con la estación de anestesia del ratón, que contiene la jaula con los ratones experimentales, la jaula estéril vacía, la anestesia a temperatura ambiente, la aguja calibre 25 y una jeringa de un mililitro.A continuación, prepare una estación de hisopado ocular que contenga el IMC alícuota en el hielo, hisopos oculares esterilizados, gotas lubricantes para los ojos, recipientes de riesgo biológico, toallas de papel limpias y aerosol de isopropanol al 70%. Finalmente, configure la estación de chapado con placas de agar sangre a temperatura ambiente, una pipeta de 10 microlitr, 10 puntas desechables estériles de microlitro y un contenedor de residuos de riesgo biológico. Asegúrese de que el ratón está correctamente anestesiado apretando una almohadilla del pie trasero.Sólo proceder si no hay movimiento. Asigne una mano para manejar ratones anestesiados y las otras manos para manejar el hisopo del ojo y la cultura. Retire el ratón de la jaula y colóelo encima de la superficie de trabajo colocada de lado con el ojo izquierdo expuesto.Rocíe las manos enguantadas con isopropanol y séquelas con una toalla de papel. Descapspeje el tubo de micro centrífuga BHI etiquetado con la mano de manejo de medios dedicada y coloque los dos de nuevo en el rack. Sumerja la punta recubierta de algodón del hisopo ocular en el IMC, luego retire el hisopo del tubo mientras arremolina la punta dos veces contra el tubo interno para eliminar el exceso de líquido y eliminarlo.Con la mano de manejo del ratón, sostenga suavemente el ratón por el desaliño del cuello. Con la otra mano, coloque la punta del hisopo ocular contra la región conjuntival medial del ojo izquierdo. Deprima ligeramente el globo ocular y mueva el hisopo en un movimiento de lavado de ventanas entre el párpado inferior y el ojo 10 veces, manteniendo una presión constante.Sin tocar el pelaje, retire suavemente la punta del hisopo perpendicular a donde se insertó. Coloque el lado de algodón hisopo hacia abajo, directamente en un tubo de micro centrífuga etiquetado con medios BHI. Aplique una gota para los ojos en el ojo hisopado.Si lo desea, adquiera hisopos de piel o piel para muestras de control, esterilizando los guantes adecuadamente entre cada hisopo. Cuando haya terminado, devuelva el ratón a la jaula. Deje reposar el hisopo durante 10 a 15 minutos sobre hielo, luego esterilice las manos enguantadas y retire el hisopo mientras mezcla la punta en el medio durante 10 rotaciones.Retire el hisopo arremolinando la punta contra la pared interna del tubo durante cinco rotaciones y deséchelo en un recipiente de riesgo biológico. Repita el proceso para cada ratón. Enriquezca la muestra incubando el tubo estáticamente durante una hora a 37 grados Centígrados.Durante la incubación, etiquete una placa de TSA a temperatura ambiente por hisopo de ojo de ratón o controle el hisopo y divídalo por la mitad. Retire las muestras enriquecidas de la incubadora y colóquelas en hielo. Brevemente vórtice las muestras a mezclar, luego alícuota 10 microlitros de la muestra en la placa TSA e incline la placa para formar una tira.Repita esto dos veces. En el otro lado de la línea divisoria de placas, cree 10 puntos con 10 microlitros de muestra cada uno. Incubar las placas a 37 grados centígrados durante 18 horas, dos días y cuatro días en una cámara limpia que evite que las placas de agar se sequen.Cuente las colonias en las tiras. Tenga en cuenta la morfología y calcule las unidades formantes de colonias por hisopo para aislados morfológicamente similares. Mira los puntos donde los organismos únicos no son capturados en las tiras.Para facilitar la visualización, plateamos las bacterias densamente en las placas central y derecha. Típicamente, observamos muchas menos bacterias en las placas de hisopos oculares. Tenga en cuenta que en ocasiones, los hisopos oculares pueden no producir bacterias recuperables.Una placa representativa de la hisopo del ojo con aislantes morfológicamente diversos de un ratón negro C57 seis se muestra aquí. Para cada aislante distinto, las colonias fueron contadas en la tira y la abundancia relativa fue calculada y trazada. Para la caracterización microbiológica, las bacterias se seleccionaron de placas individuales de hisopo de ojo de ratón para producir una placa maestra de TSA.Cuando apareció el crecimiento, se realizaron pruebas adicionales para caracterizar o identificar los microbios. La placa maestra fue utilizada para proporcionar bastante inóculo para ampliar los aislantes respectivos. Para identificar aislantes, una placa de TSA fue rayada e incubada durante la noche, y el ms de MALDI-TOF fue realizado.Los ejemplos de aislantes mostrados aquí fueron identificados como estreptococo acidominimus y viridans de Aerococcus. Niveles perceptiblemente diversos de organismos commensales fueron recuperados de los ratones negros masculinos y femeninos C57 seis. Streptococcus acidominimus, Aerococcus viridans coagula estafilococos negativos y E.coli se aislaron de C57 negro seis ratones N.Al intentar este protocolo, tenga en cuenta que el mejor resultado se logrará recubriendo el hisopo finamente y tomando tiempo durante el paso del hisopo ocular. Si el acceso a MALDI-TOF MS es limitado, entonces los aislados pueden ser identificados por pruebas microbiológicas y bioquímicas.

conjunctival-commensal-isolation-and-identification-in-mice

Research

JoVE Journal

Immunology and Infection

Isolation and Analysis of Brain-sequestered Leukocytes from Plasmodium berghei ANKA-infected Mice

We describe a method for isolation and characterization of adherent inflammatory cells from brain blood vessels of P. berghei ANKA-infected mice. Infection of susceptible mouse-strains with this parasite strain results in the induction of experimental cerebral malaria, a neurologic syndrome that recapitulates certain important aspects of Plasmodium falciparum-mediated severe malaria in humans 1,2 . Mature forms of blood-stage malaria express parasitic proteins on the surface of the infected erythrocyte, which allows them to bind to vascular endothelial cells. This process induces obstructions in blood flow, resulting in hypoxia and haemorrhages 3 and also stimulates the recruitment of inflammatory leukocytes to the site of parasite sequestration.
Unlike other infections, i.e neutrotopic viruses4-6, both malaria-parasitized red blood cells (pRBC) as well as associated inflammatory leukocytes remain sequestered within blood vessels rather than infiltrating the brain parenchyma. Thus to avoid contamination of sequestered leukocytes with non-inflammatory circulating cells, extensive intracardial perfusion of infected-mice prior to organ extraction and tissue processing is required in this procedure to remove the blood compartment. After perfusion, brains are harvested and dissected in small pieces. The tissue structure is further disrupted by enzymatic treatment with Collagenase D and DNAse I. The resulting brain homogenate is then centrifuged on a Percoll gradient that allows separation of brain-sequestered leukocytes (BSL) from myelin and other tissue debris. Isolated cells are then washed, counted using a hemocytometer and stained with fluorescent antibodies for subsequent analysis by flow cytometry.
This procedure allows comprehensive phenotypic characterization of inflammatory leukocytes migrating to the brain in response to various stimuli, including stroke as well as viral or parasitic infections. The method also provides a useful tool for assessment of novel anti-inflammatory treatments in pre-clinical animal models.

Isolation and Analysis of Brain-sequestered Leukocytes from Plasmodium berghei ANKA-infected Mice

A method for isolation of adherent inflammatory leukocytes from brain blood vessels of Plasmodium berghei ANKA-infected mice is described. The method allows quantification as well as phenotypic characterization of isolated leukocytes after staining with fluorescent antibodies and subsequent analysis by flow cytometry.

Aislamiento y análisis de Brain-secuestrados Los leucocitos de<em&gt; Plasmodium berghei</em&gt; ANKA de ratones infectados

We describe a method for isolation and  characterization of adherent inflammatory cells from brain blood vessels of P. berghei ANKA-infected mice. ...

Investigación

Inmunología e Infección

Rapid Identification of Gram Negative Bacteria from Blood Culture Broth Using MALDI-TOF Mass Spectrometry

An important role of the clinical microbiology laboratory is to provide rapid identification of bacteria causing bloodstream infection. Traditional identification requires the sub-culture of signaled blood culture broth with identification available only after colonies on solid agar have matured. MALDI-TOF MS is a reliable, rapid method for identification of the majority of clinically relevant bacteria when applied to colonies on solid media. The application of MALDI-TOF MS directly to blood culture broth is an attractive approach as it has potential to accelerate species identification of bacteria and improve clinical management. However, an important problem to overcome is the pre-analysis removal of interfering resins, proteins and hemoglobin&#160;contained in blood culture specimens which, if not removed, interfere with the MS spectra and can result in insufficient or low discrimination identification scores. In addition it is necessary to concentrate bacteria to develop spectra of sufficient quality. The presented method describes the concentration, purification, and extraction of Gram negative bacteria allowing for the early identification of bacteria from a signaled blood culture broth.

The application of matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) directly to blood culture broth expedites the identification of bacteria. The presented method is a rapid and reliable method for identification of Gram negative bacteria directly from blood culture broth.

La identificación rápida de bacterias gram negativas de Cultura sangre caldo de cultivo utilizando MALDI-TOF espectrometría de masas

An important role of the clinical microbiology laboratory is to provide rapid identification of bacteria causing bloodstream infection. Traditional ...

Isolation, Identification, and Purification of Murine Thymic Epithelial Cells

The thymus is a vital organ for T lymphocyte development. Of thymic stromal cells, thymic epithelial cells (TECs) are particularly crucial at multiple stages of T cell development: T cell commitment, positive selection and negative selection. However, the function of TECs in the thymus remains incompletely understood. In the article, we provide a method to isolate TEC subsets from fresh mouse thymus using a combination of mechanical disruption and enzymatic digestion. The method allows thymic stromal cells and thymocytes to be efficiently released from cell-cell and cell-extracellular matrix connections and to form a single-cell suspension. Using the isolated cells, multiparameter flow cytometry can be applied to identification and characterization of TECs and dendritic cells. Because TECs are a rare cell population in the thymus, we also describe an effective way to enrich and purify TECs by depleting thymocytes, the most abundant cell type in the thymus. Following the enrichment, cell sorting time can be decreased so that loss of cell viability can be minimized during purification of TECs. Purified cells are suitable for various downstream analyses like Real Time-PCR, Western blot and gene expression profiling. The protocol will promote research of TEC function and as well as the development of in vitro T cell reconstitution.

Here we describe an efficient method for isolation, identification, and purification of mouse thymic epithelial cells (TECs). The protocol can be utilized for studies of thymus function for normal T cell development, thymus dysfunction, and T cell reconstitution.

El aislamiento, la identificación y purificación de células epiteliales del timo murino

The thymus is a vital organ for T lymphocyte development. Of thymic stromal cells, thymic epithelial cells (TECs) are particularly crucial at multiple ...

Neutrophil Isolation and Analysis to Determine their Role in Lymphoma Cell Sensitivity to Therapeutic Agents

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of inflammation. They are key players in the innate immune system and play major roles in cancer biology. Neutrophils have been proposed as key mediators of malignant transformation, tumor progression, angiogenesis and in the modulation of the antitumor immunity; through their release of soluble factors or their interaction with tumor cells. To characterize the specific functions of neutrophils, a fast and reliable method is coveted for in vitro isolation of neutrophils from human blood. Here, a density gradient separation method is demonstrated to isolate neutrophils as well as mononuclear cells from the blood. The procedure consists of layering the density gradient solution such as Ficoll carefully above the diluted blood obtained from patients diagnosed with chronic lymphocytic leukemia (CLL), followed by centrifugation, isolation of mononuclear layer, separation of neutrophils from RBCsby dextran then lysis of residual erythrocytes. This method has been shown to isolate neutrophils &#8805; 90 % pure. To mimic the tumor microenvironment, 3-dimensional (3D) experiments were performed using basement membrane matrix such as Matrigel. Given the short half-life of neutrophils in vitro, 3D experiments with fresh human neutrophils cannot be performed. For this reason promyelocytic HL60 cells are differentiated along the granulocytic pathway using the differentiation inducers dimethyl sulfoxide (DMSO) and retinoic acid (RA). The aim of our experiments is to study the role of neutrophils on the sensitivity of lymphoma cells to anti-lymphoma agents. However these methods can be generalized to study the interactions of neutrophils or neutrophil-like cells with a large range of cell types in different situations.

Neutrophils are the most abundant type of white blood cells. The isolation of neutrophils from human blood by density gradient separation method and the differentiation of human promyelocytic (HL60) cells along the granulocytic pathway are described here; to test their role on sensitivity of lymphoma cells to anti-lymphoma agents.

Aislamiento de neutrófilos y análisis para determinar su papel en el linfoma de células sensibles a los agentes terapéuticos

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of ...

Identification of Plasmodesmal Localization Sequences in Proteins In Planta

Plasmodesmata (Pd) are cell-to-cell connections that function as gateways through which small and large molecules are transported between plant cells. Whereas Pd transport of small molecules, such as ions and water, is presumed to occur passively, cell-to-cell transport of biological macromolecules, such proteins, most likely occurs via an active mechanism that involves specific targeting signals on the transported molecule. The scarcity of identified plasmodesmata (Pd) localization signals (PLSs) has severely restricted the understanding of protein-sorting pathways involved in plant cell-to-cell macromolecular transport and communication. From a wealth of plant endogenous and viral proteins known to traffic through Pd, only three PLSs have been reported to date, all of them from endogenous plant proteins. Thus, it is important to develop a reliable and systematic experimental strategy to identify a functional PLS sequence, that is both necessary and sufficient for Pd targeting, directly in the living plant cells. Here, we describe one such strategy using as a paradigm the cell-to-cell movement protein (MP) of the Tobacco mosaic virus (TMV). These experiments, that identified and characterized the first plant viral PLS, can be adapted for discovery of PLS sequences in most Pd-targeted proteins.

Identification of Plasmodesmal Localization Sequences in Proteins In Planta

Plant intercellular connections, the plasmodesmata (Pd), play central roles in plant physiology and plant-virus interactions. Critical to Pd transport are sorting signals that direct proteins to Pd. However, our knowledge about these sequences is still in its infancy. We describe a strategy to identify Pd localization signals in Pd-targeted proteins.

Identificación de secuencias de localización Plasmodesmal en proteínas en Planta

Plasmodesmata (Pd) are cell-to-cell connections that function as gateways through which small and large molecules are transported between plant cells. ...

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages

Salmonella typhimurium is a facultative intracellular bacterium that causes gastroenteritis in humans. After invasion of the lamina propria, S. typhimurium bacteria are quickly detected and phagocytized by macrophages, and contained in vesicles known as phagosomes in order to be degraded. Isolation of S. typhimurium-containing phagosomes have been widely used to study how S. typhimurium infection alters the process of phagosome maturation to prevent bacterial degradation. Classically, the isolation of bacteria-containing phagosomes has been performed by sucrose gradient centrifugation. However, this process is time-consuming, and requires specialized equipment and a certain degree of dexterity. Described here is a simple and quick method for the isolation of S. typhimurium-containing phagosomes from macrophages by coating the bacteria with biotin-streptavidin-conjugated magnetic beads. Phagosomes obtained by this method can be suspended in any buffer of choice, allowing the utilization of isolated phagosomes for a broad range of assays, such as protein, metabolite, and lipid analysis. In summary, this method for the isolation of S. typhimurium-containing phagosomes is specific, efficient, rapid, requires minimum equipment, and is more versatile than the classical method of isolation by sucrose gradient-ultracentrifugation.

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages

We describe here a simple and quick method for the isolation of Salmonella typhimurium-containing phagosomes from macrophages by coating the bacteria with biotin and streptavidin.

Aislamiento de Salmonella typhimurium-que contienen fagosomas de los macrófagos

Salmonella typhimurium is a facultative intracellular bacterium that causes gastroenteritis in humans. After invasion of the lamina propria, S. ...

Identification and Isolation of Oligopotent and Lineage-committed Myeloid Progenitors from Mouse Bone Marrow

Myeloid progenitors that yield neutrophils, monocytes and dendritic cells (DCs) can be identified in and isolated from the bone marrow of mice for hematological and immunological analyses. For example, studies of the cellular and molecular properties of myeloid progenitor populations can reveal mechanisms underlying leukemic transformation, or demonstrate how the immune system responds to pathogen exposure. Previously described flow cytometry strategies for myeloid progenitor identification have enabled significant advances in many fields, but the fractions they identify are very heterogeneous. The most commonly used gating strategies define bone marrow fractions that are enriched for the desired populations, but also contain large numbers of &#34;contaminating&#34; progenitors. Our recent studies have resolved much of this heterogeneity, and the protocol we present here permits the isolation of 6 subpopulations of oligopotent and lineage-committed myeloid progenitors from 2 previously described bone marrow fractions. The protocol describes 3 stages: 1) isolation of bone marrow cells, 2) enrichment for hematopoietic progenitors by magnetic-activated cell sorting (lineage depletion by MACS), and 3) identification of myeloid progenitor subsets by flow cytometry (including fluorescence-activated cell sorting, FACS, if desired). This approach permits progenitor quantification and isolation for a variety of in vitro and in vivo applications, and has already yielded novel insight into pathways and mechanisms of neutrophil, monocyte, and DC differentiation.

We demonstrate how to identify and isolate 6 subsets of myeloid progenitors from murine bone marrow using a combination of magnetic and fluorescence sorting (MACS and FACS). This protocol can be used for in vitro culture assays (methylcellulose or liquid cultures), in vivo adoptive transfer experiments, and RNA/protein analyses.

Identificación y aislamiento de Oligopotent y linaje comprometido progenitores mieloides de la médula ósea de ratón

Myeloid progenitors that yield neutrophils, monocytes and dendritic cells (DCs) can be identified in and isolated from the bone marrow of mice for ...

Isolation and Identification of Extravascular Immune Cells of the Heart

The immune system is an essential component of a healthy heart. The myocardium is home to a rich population of different immune cell subsets with functional compartmentalization both during steady state and during different forms of inflammation. Until recently, the study of immune cells in the heart required the use of microscopy or poorly developed digestion protocols, which provided enough sensitivity during severe inflammation but were unable to confidently identify small &#8212; but key &#8212; populations of cells during steady state. Here, we discuss a simple method combining enzymatic (collagenase, hyaluronidase and DNAse) and mechanical digestion of murine hearts preceded by intravascular administration of fluorescently-labelled antibodies to differentiate small but unavoidable intravascular cell contaminants. This method generates a suspension of isolated viable cells that can be analyzed by flow cytometry for identification, phenotyping and quantification, or further purified with fluorescence-activated cell sorting or magnetic bead separation for transcriptional analysis or in vitro studies. We include an example of a step-by-step flow cytometric analysis to differentiate the key macrophage and dendritic cell populations of the heart. For a medium sized experiment (10 hearts) the completion of the procedure requires 2&#8211;3 h.

This protocol presents a simple and efficient method to isolate, identify and quantify immune cells residing in the myocardium of mice during steady state or inflammation. The protocol combines enzymatic and mechanical digestion for the generation of a single cell suspension that can be further analyzed by flow cytometry.

Aislamiento e identificación de las células inmunes Extravascular del corazón

The immune system is an essential component of a healthy heart. The myocardium is home to a rich population of different immune cell subsets with ...

A Galleria mellonella Oral Administration Model to Study Commensal-Induced Innate Immune Responses

The investigation of the immunogenic potential of commensal bacteria on the host immune system is one essential component when studying intestinal host-microbe interactions. It is well established that different commensals exhibit a different potential to stimulate the host intestinal immune system. Such investigations involve vertebrate animals, especially rodents. Since increasing ethical concerns are linked with experiments involving vertebrates, there is a high demand for invertebrate replacements models. 
Here, we provide a Galleria mellonella oral administration model using commensal non-pathogenic bacteria and the possible assessment of the immunogenic potential of commensals on the G. mellonella immune system. We demonstrate that G. mellonella is a useful alternative invertebrate replacement model that allows the analysis of commensals with different immunogenic potential such as Bacteroides vulgatus and Escherichia coli. Interestingly, the bacteria exhibited no killing effect on the larvae, which is similar to mammals. The immune responses of G. mellonella were comparable with vertebrate innate immune responses and involve recognition of the bacteria and production of antimicrobial molecules. We propose that G. mellonella was able to restore previous microbiota balance, which is well known from healthy mammalian individuals. Although providing comparable innate immune responses in both G. mellonella and vertebrates, G. mellonella does not harbor an adaptive immune system. Since the investigated components of the innate immune system are evolutionary conserved, the model allows a prescreening and first analysis of bacterial immunogenic properties.

A Galleria mellonella Oral Administration Model to Study Commensal-Induced Innate Immune Responses

Here, we provide a detailed protocol for an oral administration model using Galleria mellonella larvae and how to characterize induced innate immune responses. Using this protocol, researchers without practical experience will be able to use the G. mellonella force-feeding method.

Un modelo de administración Oral de Galleria mellonella para la respuesta inmune innata Study Commensal-Induced

The investigation of the immunogenic potential of commensal bacteria on the host immune system is one essential component when studying intestinal ...

Quantifying Human Norovirus Virus-like Particles Binding to Commensal Bacteria Using Flow Cytometry

Commensal bacteria are well established to impact infection of eukaryotic viruses. Direct binding between the pathogen and the host microbiome is responsible for altering infection for many of these viruses. Thus, characterizing the nature of virus-bacteria binding is a foundational step needed for elucidating the mechanism(s) by which bacteria alter viral infection. For human norovirus, commensal bacteria enhance B cell infection. The virus directly binds to these bacteria, indicating that this direct interaction is involved in the mechanism of infection enhancement. A variety of techniques can be used to quantify interactions between bacteria and viruses including scintillation counting of radiolabeled viruses and polymerase chain reaction (PCR). Both methods require the use of live virus, which may need to be generated in the laboratory. Currently, none of the established in vitro culture systems available for human norovirus are robust enough to allow for generation of highly concentrated viral stocks. In lieu of live virus, virus-like particles (VLPs) have been used to characterize the interactions between norovirus and bacteria. Herein a flow cytometry method is described with uses virus specific antibodies to quantify VLP binding to gram-negative and gram-positive bacteria. Inclusion of both bacteria only and isotype controls allowed for optimization of the assay to reduce background antibody binding and accurate quantification of VLP attachment to the bacteria tested. High VLP:bacterium ratios result in VLPs binding to large percentages of the bacterial population. However, when VLP quantities are decreased, the percent of bacteria bound also decreases. Ultimately, this method can be employed in future experiments elucidating the specific conditions and structural components that regulate norovirus:bacterial interactions.

The goal of this protocol is to quantify binding of the eukaryotic pathogen human norovirus to bacteria. After performing an initial virus-bacterium attachment assay, flow cytometry is used to detect virally-bound bacteria within the population.