Agradecemos sinceramente a los miembros del laboratorio Pal para asistencia en la preparación de esta manifestación. Este estudio fue apoyado por subvenciones PHS AI076684 y AI080615 de los NIH / NIAID.

1. Microinyección de ninfas garrapatas Ixodes scapularis 1. Preparación de las agujas <ol><li> Fabricar varias agujas de microinyección de calefacción y tirar de un tubo de vidrio capilar mm (Instrumentos del Mundo de precisión) en un dispositivo de cristal micropipeta extractor (Narishige). Retire con cuidado los tubos capilares frágiles. </li><li> Tienda sacó agujas (con la punta hacia arriba) en la cinta adhesiva en una placa de Petri. </li></ol> 2. La preparación de B. burgdorferi <ol><li> Crecer B. burgdorferi en medios de cultivo BSK 7 hasta una concentración de alrededor de 10 7 células por ml. Las espiroquetas son contados bajo un microscopio de campo oscuro por el uso de una cámara de recuento de Petroff-Hausser (Hausser científica). </li><li> Pellet B. burgdorferi por centrifugación a 3.000 xg durante 10 minutos a temperatura ambiente. </li><li> Quitar el sobrenadante y resuspender el precipitado completamente en los medios de comunicación BSK suavemente pasando por una de 200 l micropunta estéril a una concentración final de 10 9 células por ml. Dado que las células se resuspenden en alta densidad celular, y podría agruparse, la suspensión celular se debe utilizar para la microinyección de inmediato. </li></ol> 3. Preparación de las garrapatas <ol><li> Lugar claro, cinta de doble cara adhesiva sobre un portaobjetos de vidrio. </li><li> Trabajo sobre una estera pegajosa, retire con cuidado las garrapatas ninfas del envase con un cepillo pequeño. </li><li> Introducir el número de garrapatas que se inyecta en la cinta adhesiva, lado ventral hacia arriba, en la misma dirección. </li></ol> 4. Garrapatas inyección <ol><li> Carga de 5 l de la B. burgdorferi la cultura en la aguja sacó capilar mediante un 20 l microloader punta de la pipeta (Eppendorf). Inspeccione la aguja de burbujas de aire atrapadas y volver a cargar la aguja con el cultivo de bacterias, si es necesario. </li><li> Ver la garrapata en el microscopio binocular de disección y se centran en el área de la garrapata apertura anal. Toque suavemente la punta de la aguja capilar con el fin de romper el tubo, cuando el diámetro es ligeramente más pequeño que el de la apertura anal de la garrapata, que forman la aguja de microinyección. Este paso es fundamental ya que cualquier intento de inyectar las garrapatas con una punta de la aguja no apropiado causas de mortalidad por lesiones y posibles de la garrapata inyecta. </li><li> Coloque la garrapata inmovilizado bajo el microscopio binocular de disección y se centran en la apertura anal, que está cubierto por dos placas móviles anal. Con unas pinzas finas, toque suavemente y aplicar una presión muy leve a una zona cerca de la abertura anal. Esto permitirá la separación de las placas anales y la apertura del poro anal que se conecta al intestino. Con cuidado, inserte la punta de la aguja ligeramente en la apertura anal a través de la apertura forzada de las placas anales. Inserción de la aguja debe mantenerse al mínimo, ya que la punta de vidrio podría dañar el intestino grueso semitransparente que se conecta con el recto. El uso de un microinyector equipado con pedal automático (Eppendorf), inyectar B. burgdorferi solución utilizando los siguientes parámetros: 1,000 hectopascales (hPa) la presión de inyección, tiempo de inyección de 0,2 segundos y 8 de compensación de presión hPa. Cada marca recibe una sola inyección. </li><li> Después de la microinyección, la garrapata debe comportarse similar al estado de pre-inyección. Por ejemplo, la garrapata debe arrastrarse en respuesta a estímulos. </li><li> Por lo general, permiten a las garrapatas a recuperarse durante 48 horas en una cámara fijada en 24 ° C con 16 horas / 8 horas de luz / oscuridad régimen de fotoperíodo y el 95% de humedad. Si una cámara no está disponible, las garrapatas inyectadas podrían ser almacenados a temperatura ambiente en condiciones de humedad dentro de un envase hermético, como una cámara de desecador regular. Si es necesario, el tiempo de recuperación de las garrapatas también pueden reducirse a unas pocas horas antes de utilizarse para la alimentación de los ratones. </li></ol> 2. B. burgdorferi de localización por microscopía de inmunofluorescencia confocal 1. Las garrapatas de disección <ol><li> Coloque una gota de tampón fosfato salino (PBS) en un portaobjetos de vidrio limpio para la disección y la otra en un portaobjetos recubiertos con poli-L-lisina (Sigma) para la microscopía. Se prepara otro portaobjetos de vidrio con cinta adhesiva de doble cara. </li><li> Quite la marca del envase y el lugar en la cinta adhesiva de doble cara con un cepillo pequeño. </li><li> Vista y el enfoque de la garrapata en el microscopio de disección. Coloque una hoja de afeitar aguda en la marca entre el primer y segundo par de patas. Presione con firmeza el corte de la señal en dos piezas permite el acceso al abdomen. Inmediatamente, se sumergen en el abdomen en una gota de PBS. </li><li> Con unas pinzas muy finas, coge el exoesqueleto dorsal y ventral de todo el sitio del corte. Saque con cuidado el escudo dorsal hacia arriba y lejos de la garrapata marrón exponer los divertículos intestinales de color. Tenga cuidado de mantener las garrapatas de disección en la PBS en todo momento. </li><li> El bollo semi-transparente la glándula salivaljas se encuentran a ambos lados de la región anterior del intestino, y se puede quitar en este momento, si así lo desea. Sosteniendo el exoesqueleto que permanecen en el lugar con unas pinzas, extraiga cuidadosamente el intestino fuera del abdomen. </li><li> Limpie cuidadosamente el intestino, eliminando los tejidos atrapados (por ejemplo, la tráquea). </li><li> Con la punta de unas pinzas finas, de forma rápida transferencia de los intestinos de garrapatas en una gota de PBS en un portaobjetos de vidrio con poli-L-lisina. Separar el intestino en pedazos más pequeños con hojas finas o presionando suavemente con la punta de unas pinzas finas. Con cuidado aspirar el exceso de PBS en todo el tejido intestinal. </li><li> Permitir que los tejidos intestinales de aire seco a temperatura ambiente. </li><li> Fijar el intestino de garrapatas al sumergir en acetona durante 10 minutos. Deje secar al aire a temperatura ambiente. Las diapositivas se pueden almacenar en este paso por varios meses a -20 ° C en un recipiente hermético. </li></ol> 2. Tinción <ol><li> Utilizando un pañuelo de papel, retire el exceso de humedad en todo el tejido y dibujar un círculo alrededor de la barriga de garrapatas secas por un pap-pluma o cualquier otro dispositivo revestimiento barrera hidrofóbica. Esto ayudará a mantener las soluciones de tinción durante las etapas de incubación posterior. </li><li> Cubren el intestino marque con una o unas pocas gotas de tampón de bloqueo (0,05% Tween-20, 5% de suero de cabra en PBS) durante 30 minutos a temperatura ambiente. El suero utilizado para bloquear depende de la fuente del animal huésped para el anticuerpo. No permita que se seque la diapositiva a partir de ahora. </li><li> Poco a poco aspirar el tampón de bloqueo. Incubar el intestino con primaria adecuada y / o soluciones de secundaria de anticuerpos. Usamos isotiocianato de fluoresceína (FITC) - anticuerpo anti-B. burgdorferi de anticuerpos (Kirkegaard &amp; Perry Laboratories) a una dilución 1:100 en tampón de bloqueo durante 1 hora a temperatura ambiente. Cubra el recipiente con papel de aluminio para limitar la exposición a la luz. </li><li> Retire la solución de anticuerpos por aspiración suave. Incubar el intestino con un colorante fluorescente a los tejidos marque la etiqueta, tal como 4 &#39;,6-diamidino-2-phenylindole (DAPI) o yoduro de propidio. Normalmente se usan 20 mg / ml de yoduro de propidio (Sigma) en PBS durante 5 min. a temperatura ambiente. </li><li> Lavar 3 veces con 0,05% de Tween-20 en PBS. </li><li> Monte la diapositiva en glicerina tamponada que contiene un reactivo Antifade como Slowfade (Invitrogen) y con cuidado cubrir con un cubreobjetos. Las diapositivas se pueden almacenar en este paso por unos meses a 4 ° C en un recipiente hermético. La imagen y localizar B. burgdorferi bajo un microscopio confocal. </li></ol> 3. Resultados representante Posición de una marca de ninfa para la microinyección y una imagen que representa B. localización burgdorferi en el intestino de garrapatas se presenta en la Figura 1. <img src="/files/ftp_upload/2544/2544fig1.jpg" alt="Figura 1" /> Figura 1. Microinyección y la localización de la B. burgdorferi en el intestino de garrapatas. (A) Vista ventral de una ninfa I. garrapata scapularis posicionado para la microinyección. Culo de apertura (cabeza de flecha), con aguja insertada microinyección (flecha) se muestra con una lupa en el recuadro. Una pinza fina se utiliza para aplicar una presión suave para el cuerpo, lo que permitió la separación de las placas anales y la apertura del poro anal para la microinyección. La aguja se llena con una solución de azul brillante de Coomassie para mejorar la visibilidad. (B) Los resultados representativos de la imagen confocal de inmunofluorescencia B. burgdorferi en intestino de garrapatas. Región anterior de un divertículo del intestino se muestra. Núcleos intestinal y espiroquetas (flecha) se marcan con yoduro de propidio (color rojo) o FITC-conjugado anti-B. burgdorferi (color verde), respectivamente. Bar = 20 micras.

<ol>
	<li>Steere, A. C., Coburn, J., Glickstein, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+emergence+of+Lyme+disease.">The emergence of Lyme disease.</a> J Clin Invest. 113, 1093-1101 (2004).</li><li>Barthold, S. W., Diego, C., Philipp, M. T., Samuels, D. S., Radolf, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Borrelia, Molecular Biology, Host Interaction and Pathogenesis. , 353-405 (2010).</li><li>Pal, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=OspC+facilitates+Borrelia+burgdorferi+invasion+of+Ixodes+scapularis+salivary+glands.">OspC facilitates Borrelia burgdorferi invasion of Ixodes scapularis salivary glands.</a> J Clin Invest. 113, 220-230 (2004).</li><li>Yang, X. F., Pal, U., Alani, S. M., Fikrig, E., Norgard, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Essential+role+for+OspA/B+in+the+life+cycle+of+the+Lyme+disease+spirochete.">Essential role for OspA/B in the life cycle of the Lyme disease spirochete.</a> J Exp Med. 199, 641-648 (2004).</li><li>Zhang, X., Yang, X., Kumar, M., Pal, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=BB0323+function+is+essential+for+Borrelia+burgdorferi+virulence+and+persistence+through+tick-rodent+transmission+cycle.">BB0323 function is essential for Borrelia burgdorferi virulence and persistence through tick-rodent transmission cycle.</a> J Infect Dis. 200, 1318-1330 (2009).</li><li>Pal, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TROSPA,+an+Ixodes+scapularis+receptor+for+Borrelia+burgdorferi.">TROSPA, an Ixodes scapularis receptor for Borrelia burgdorferi.</a> Cell. 119, 457-468 (2004).</li><li>Barbour, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+cultivation+of+Lyme+disease+spirochetes.">Isolation and cultivation of Lyme disease spirochetes.</a> Yale J Biol Med. 57, 521-525 (1984).</li><li>Narasimhan, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disruption+of+Ixodes+scapularis+anticoagulation+by+using+RNA+interference.">Disruption of Ixodes scapularis anticoagulation by using RNA interference.</a> Proc Natl Acad Sci U S A. 101, 1141-1146 (2004).</li><li>Narasimhan, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+tick+antioxidant+facilitates+the+Lyme+disease+agent's+successful+migration+from+the+mammalian+host+to+the+arthropod+vector.">A tick antioxidant facilitates the Lyme disease agent's successful migration from the mammalian host to the arthropod vector.</a> Cell Host Microbe. 2, 7-18 (2007).</li><li>Broadwater, A. H., Sonenshine, D. E., Hynes, W. L., Ceraul, S., DeSilva, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glass+capillary+tube+feeding:+a+method+for+infecting+nymphal+Ixodes+scapularis+(Acari:+Ixodidae)+with+the+Lyme+disease+spirochete+Borrelia+burgdorferi.">Glass capillary tube feeding: a method for infecting nymphal Ixodes scapularis (Acari: Ixodidae) with the Lyme disease spirochete Borrelia burgdorferi.</a> J Med Entomol. 39, 285-292 (2002).</li><li>Policastro, P. F., Schwan, T. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+infection+of+Ixodes+scapularis+larvae+(Acari:+Ixodidae)+by+immersion+in+low+passage+cultures+of+Borrelia+burgdorferi.">Experimental infection of Ixodes scapularis larvae (Acari: Ixodidae) by immersion in low passage cultures of Borrelia burgdorferi.</a> J Med Entomol. 40, 364-370 (2003).</li><li>Fuente, d. e. l. a., Kocan, J., M, K., Almazan, C., Blouin, E. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNA+interference+for+the+study+and+genetic+manipulation+of+ticks.">RNA interference for the study and genetic manipulation of ticks.</a> Trends Parasitol. 23, 427-433 (2007).</li></ol>

Aquí se demuestra un procedimiento basado en la microinyección de infección rápida y eficiente de las garrapatas Ixodes ninfa con el patógeno bacteriano B. burgdorferi. También describe un procedimiento confocal de inmunofluorescencia para la detección de B. burgdorferi en el intestino de garrapatas en el lugar. A pesar de nuestra demostración consiste en tripa de ninfa, procedimientos similares se aplican también a otras etapas de desarrollo de las garrapatas, tales como larvas o adu...

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<td>Glass capillary tubes</td>
<td>&nbsp;</td>
<td>World Precision Instruments</td>
<td>TW100F-4</td>
<td>&nbsp;</td>
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<td>Vertical glass puller</td>
<td>&nbsp;</td>
<td>Narishige</td>
<td>PC-10</td>
<td>&nbsp;</td>
<tr>
<td>Petroff-Hausser counting chamber</td>
<td>&nbsp;</td>
<td>Hausser scientific</td>
<td>3900</td>
<td>&nbsp;</td>
<tr>
<td>Microloader pipette tips</td>
<td>&nbsp;</td>
<td>Eppendorf</td>
<td>930001007</td>
<td>&nbsp;</td>
<tr>
<td>Femtojet microinjector</td>
<td>&nbsp;</td>
<td>Eppendorf</td>
<td>920010504</td>
<td>&nbsp;</td>
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<td>Foot control FemtJet</td>
<td>&nbsp;</td>
<td>Eppendorf</td>
<td>920005098</td>
<td>&nbsp;</td>
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<td>Phosphate buffered saline</td>
<td>&nbsp;</td>
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methods for rapid transfer and localization of lyme disease pathogens within the tick gut

La enfermedad de Lyme es una infección producida por la espiroqueta Borrelia burgdorferi patógeno, que se mantiene en la naturaleza por un ciclo de infección por garrapatas de roedores 1. Un modelo murino transmitida por garrapatas 2 ha sido desarrollado para estudiar la enfermedad de Lyme en el laboratorio. Mientras que las garrapatas ingenuo puede estar infectada con B. burgdorferi por la alimentación de los ratones infectados, el proceso de muda lleva varias semanas o meses en completarse. Por lo tanto, el desarrollo de las técnicas de infección más rápida y eficiente de garrapatas, tales como un procedimiento basado en la microinyección, es una herramienta importante para el estudio de la enfermedad de Lyme 3,4. El procedimiento requiere sólo unas horas para generar garrapatas infectadas y permite el control sobre la entrega de cantidades iguales de las espiroquetas en una cohorte de garrapatas. Esto es particularmente importante en la generación de B. garrapatas burgdorferi infectados por el proceso natural de alimentación con ratones no garantiza 100% la tasa de infección y, posiblemente, resultados en la variación de la carga de patógenos entre las garrapatas alimentadas. Por otra parte, la microinyección se puede utilizar para infectar a las garrapatas con B. burgdorferi aislados en los casos en que una cepa atenuada es incapaz de establecer la infección en ratones y por lo tanto no puede ser adquirida de forma natural por las garrapatas 5. Esta técnica también se puede utilizar para ofrecer una variedad de otros materiales biológicos en las garrapatas, por ejemplo, anticuerpos específicos o de ARN de doble cadena 6. En este artículo, vamos a demostrar la microinyección de garrapatas ninfas con in vitro cultivados en B. burgdorferi. También se describe un método para la localización de la enfermedad de Lyme patógenos en el intestino de garrapatas mediante microscopía confocal de inmunofluorescencia.

Watch this Scientific Journal Video about Methods for Rapid Transfer and Localization of Lyme Disease Pathogens Within the Tick Gut at JoVE.com

Methods for Rapid Transfer and Localization of Lyme Disease Pathogens Within the Tick Gut

Lyme estudios de investigación de la enfermedad a menudo requieren la generación de garrapatas infectadas con el patógeno Borrelia burgdorferi, un proceso que suele tardar varias semanas. Aquí se demuestra un procedimiento tick microinyección basado en una infección que se puede lograr en cuestión de horas. También demostramos un método de inmunofluorescencia para la localización in situ de B. burgdorferi en garrapatas.

Métodos para la transferencia rápida y localización de la enfermedad de Lyme patógenos en el intestino garrapatas

Lyme disease is caused by infection with the spirochete pathogen Borrelia burgdorferi, which is maintained in nature by a tick-rodent infection cycle 1.  ...

methods-for-rapid-transfer-localization-lyme-disease-pathogens-within

Research

JoVE Journal

Immunology and Infection

11.5K vistas.  University of Maryland. Lyme estudios de investigación de la enfermedad a menudo requieren la generación de garrapatas infectadas con el patógeno Borrelia burgdorferi, un proceso que suele tardar varias semanas. Aquí se demuestra un procedimiento tick microinyección basado en una infección que se puede lograr en cuestión de horas. También demostramos un método de inmunofluorescencia para la localización in situ de B. burgdorferi en garrapatas.

Video: Methods for Rapid Transfer and Localization of Lyme Disease Pathogens Within the Tick Gut

Saliva, Salivary Gland, and Hemolymph Collection from Ixodes scapularis Ticks

Ticks are found worldwide and afflict humans with many tick-borne illnesses. Ticks are vectors for pathogens that cause Lyme disease and tick-borne relapsing fever (Borrelia spp.), Rocky Mountain Spotted fever (Rickettsia rickettsii), ehrlichiosis (Ehrlichia chaffeensis and E. equi), anaplasmosis (Anaplasma phagocytophilum), encephalitis (tick-borne encephalitis virus), babesiosis (Babesia spp.), Colorado tick fever (Coltivirus), and tularemia (Francisella tularensis) 1-8. To be properly transmitted into the host these infectious agents differentially regulate gene expression, interact with tick proteins, and migrate through the tick 3,9-13. For example, the Lyme disease agent, Borrelia burgdorferi, adapts through differential gene expression to the feast and famine stages of the tick's enzootic cycle 14,15. Furthermore, as an Ixodes tick consumes a bloodmeal Borrelia replicate and migrate from the midgut into the hemocoel, where they travel to the salivary glands and are transmitted into the host with the expelled saliva 9,16-19.
As a tick feeds the host typically responds with a strong hemostatic and innate immune response 11,13,20-22. Despite these host responses, I. scapularis can feed for several days because tick saliva contains proteins that are immunomodulatory, lytic agents, anticoagulants, and fibrinolysins to aid the tick feeding 3,11,20,21,23. The immunomodulatory activities possessed by tick saliva or salivary gland extract (SGE) facilitate transmission, proliferation, and dissemination of numerous tick-borne pathogens 3,20,24-27. To further understand how tick-borne infectious agents cause disease it is essential to dissect actively feeding ticks and collect tick saliva. This video protocol demonstrates dissection techniques for the collection of hemolymph and the removal of salivary glands from actively feeding I. scapularis nymphs after 48 and 72 hours post mouse placement. We also demonstrate saliva collection from an adult female I. scapularis tick.

Saliva, Salivary Gland, and Hemolymph Collection from Ixodes scapularis Ticks

The collection of infected tick hemolymph, salivary glands, and saliva is important to study how tick-borne pathogens cause disease. In this protocol we demonstrate how to collect hemolymph and salivary glands from feeding Ixodes scapularis nymphs. We also demonstrate saliva collection from female I. scapularis adults.

La saliva, la glándula salival, y la Colección hemolinfa de las garrapatas Ixodes scapularis

Ticks are found worldwide and afflict humans with many tick-borne illnesses. Ticks are vectors for pathogens that cause Lyme disease and tick-borne ...

Investigación

Inmunología e Infección

Establishing a Liquid-covered Culture of Polarized Human Airway Epithelial Calu-3 Cells to Study Host Cell Response to Respiratory Pathogens In vitro

The apical and basolateral surfaces of airway epithelial cells demonstrate directional responses to pathogen exposure in vivo. Thus, ideal in vitro models for examining cellular responses to respiratory pathogens polarize, forming apical and basolateral surfaces. One such model is differentiated normal human bronchial epithelial cells (NHBE). However, this system requires lung tissue samples, expertise isolating and culturing epithelial cells from tissue, and time to generate an air-liquid interface culture.
Calu-3 cells, derived from a human bronchial adenocarcinoma, are an alternative model for examining the response of proximal airway epithelial cells to respiratory insult1, pharmacological compounds2-6, and bacterial7-9 and viral pathogens, including influenza virus, rhinovirus and severe acute respiratory syndrome - associated coronavirus10-14. Recently, we demonstrated that Calu-3 cells are susceptible to respiratory syncytial virus (RSV) infection in a manner consistent with NHBE15,16 . Here, we detail the establishment of a polarized, liquid-covered culture (LCC) of Calu-3 cells, focusing on the technical details of growing and culturing Calu-3 cells, maintaining cells that have been cultured into LCC, and we present the method for performing respiratory virus infection of polarized Calu-3 cells.
To consistently obtain polarized Calu-3 LCC, Calu-3 cells must be carefully subcultured before culturing in Transwell inserts. Calu-3 monolayer cultures should remain below 90% confluence, should be subcultured fewer than 10 times from frozen stock, and should regularly be supplied with fresh medium. Once cultured in Transwells, Calu-3 LCC must be handled with care. Irregular media changes and mechanical or physical disruption of the cell layers or plates negatively impact polarization for several hours or days. Polarization is monitored by evaluating trans-epithelial electrical resistance (TEER) and is verified by evaluating the passive equilibration of sodium fluorescein between the apical and basolateral compartments17,18 . Once TEER plateaus at or above 1,000 &Omega;&times;cm2, Calu-3 LCC are ready to use to examine cellular responses to respiratory pathogens.

Establishing a Liquid-covered Culture of Polarized Human Airway Epithelial Calu-3 Cells to Study Host Cell Response to Respiratory Pathogens In vitro

The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.

El establecimiento de un cultivo líquido cubierto de las vías respiratorias humanas epiteliales polarizadas Calu-3 células para estudiar la respuesta del huésped celular a patógenos respiratorios<em&gt; In vitro</em

The  apical and basolateral surfaces of airway epithelial cells demonstrate  directional responses to pathogen exposure in  vivo. Thus, ideal in vitro ...

Feeding of Ticks on Animals for Transmission and Xenodiagnosis in Lyme Disease Research

Transmission of the etiologic agent of Lyme disease, Borrelia burgdorferi, occurs by the attachment and blood feeding of Ixodes species ticks on mammalian hosts. In nature, this zoonotic bacterial pathogen may use a variety of reservoir hosts, but the white-footed mouse (Peromyscus leucopus) is the primary reservoir for larval and nymphal ticks in North America. Humans are incidental hosts most frequently infected with B. burgdorferi by the bite of ticks in the nymphal stage. B. burgdorferi adapts to its hosts throughout the enzootic cycle, so the ability to explore the functions of these spirochetes and their effects on mammalian hosts requires the use of tick feeding. In addition, the technique of xenodiagnosis (using the natural vector for detection and recovery of an infectious agent) has been useful in studies of cryptic infection. In order to obtain nymphal ticks that harbor B. burgdorferi, ticks are fed live spirochetes in culture through capillary tubes. Two animal models, mice and nonhuman primates, are most commonly used for Lyme disease studies involving tick feeding. We demonstrate the methods by which these ticks can be fed upon, and recovered from animals for either infection or xenodiagnosis.

Lyme disease is the most commonly-reported vector-borne disease in North America. The causative agent, Borrelia burgdorferi is a spirochete bacterium transmitted by Ixodid ticks. Transmission and detection of infection in animal models is optimized by the use of tick feeding, which we describe here.

La alimentación de las garrapatas de los animales para Transmisión y xenodiagnóstico en Lyme Investigación de Enfermedades

Transmission of the etiologic agent of Lyme disease, Borrelia burgdorferi, occurs by the  attachment and blood feeding of Ixodes species ticks on ...

Rescue of Recombinant Newcastle Disease Virus from cDNA

Newcastle disease virus (NDV), the prototype member of the Avulavirus genus of the family Paramyxoviridae1, is a non-segmented, negative-sense, single-stranded, enveloped RNA virus (Figure 1) with potential applications as a vector for vaccination and treatment of human diseases. In-depth exploration of these applications has only become possible after the establishment of reverse genetics techniques to rescue recombinant viruses from plasmids encoding their complete genomes as cDNA2-5. Viral cDNA can be conveniently modified in vitro by using standard cloning procedures to alter the genotype of the virus and/or to include new transcriptional units. Rescue of such genetically modified viruses provides a valuable tool to understand factors affecting multiple stages of infection, as well as allows for the development and improvement of vectors for the expression and delivery of antigens for vaccination and therapy. Here we describe a protocol for the rescue of recombinant NDVs.

Newcastle disease virus (NDV) has been extensively studied in the last few years in order to develop new vectors for vaccination and therapy, among others. These studies have been possible due to techniques to rescue recombinant virus from cDNA, such as those we describe here.

Rescate del virus de la enfermedad de Newcastle recombinante a partir de cDNA

Newcastle disease virus (NDV), the prototype member of  the Avulavirus genus of the family Paramyxoviridae1, is a non-segmented,  negative-sense, ...

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus

One important feature of the major opportunistic human pathogen Staphylococcus aureus is its extraordinary ability to rapidly acquire resistance to antibiotics. Genomic studies reveal that S. aureus carries many virulence and resistance genes located in mobile genetic elements, suggesting that horizontal gene transfer (HGT) plays a critical role in S. aureus evolution. However, a full and detailed description of the methodology used to study HGT in S. aureus is still lacking, especially regarding natural transformation, which has been recently reported in this bacterium. This work describes three protocols that are useful for the in vitro investigation of HGT in S. aureus: conjugation, phage transduction, and natural transformation. To this aim, the cfr gene (chloramphenicol/florfenicol resistance), which confers the Phenicols, Lincosamides, Oxazolidinones, Pleuromutilins, and Streptogramin A (PhLOPSA)-resistance phenotype, was used. Understanding the mechanisms through which S. aureus transfers genetic materials to other strains is essential to comprehending the rapid acquisition of resistance and helps to clarify the modes of dissemination reported in surveillance programs or to further predict the spreading mode in the future.

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus

We describe here three different protocols for the in vitro investigation of conjugation, transduction, and natural transformation in Staphylococcus aureus.

Metodología para el Estudio de la transferencia horizontal de genes en<em&gt; Staphylococcus aureus</em

One important feature of the major opportunistic human pathogen Staphylococcus aureus is its extraordinary ability to rapidly acquire resistance to ...

Rapid, Safe, and Simple Manual Bedside Nucleic Acid Extraction for the Detection of Virus in Whole Blood Samples

The rapid diagnosis of an infection is essential for the outbreak management, risk containment, and patient care. We have previously shown a method for the rapid bedside inactivation of the Ebola virus during blood sampling for safe nucleic acid (NA) tests by adding a commercial lysis/binding buffer directly into the vacuum blood collection tubes. Using this bedside inactivation approach, we have developed a safe, rapid, and simplified bedside NA extraction method for the subsequent detection of a virus in lysis/binding buffer-inactivated whole blood. The NA extraction is directly performed in the blood collection tubes and requires no equipment or electricity. 
After the blood is collected into the lysis/binding buffer, the contents are mixed by flipping the tube by hand, and the mixture is incubated for 20 min at room temperature. Magnetic glass particles (MGPs) are added to the tube, and the contents are mixed by flipping the collection tube by hand. The MGPs are then collected on the side of the blood collection tube using a magnetic holder or a magnet and a rubber band. The MGPs are washed three times, and after the addition of elution buffer directly into the collection tube, the NAs are ready for NA tests, such as qPCR or isothermal loop amplification (LAMP), without the removal of the MGPs from the reaction. The NA extraction method is not dependent on any laboratory facilities and can easily be used anywhere (e.g., in field hospitals and hospital isolation wards). When this NA extraction method is combined with LAMP and a portable instrument, a diagnosis can be obtained within 40 min of the blood collection.

Here, we present a protocol for the rapid virus nucleic acid extraction from the virus-inactivated whole blood. The extraction is performed directly in the blood collection tubes and requires no equipment or electricity. The method is not dependent on laboratory facilities and can be used anywhere (e.g., in field hospitals).

Extracción rápido, seguro y sencillo Manual cabecera de ácido nucleico para la detección del Virus en muestras de sangre entera

The rapid diagnosis of an infection is essential for the outbreak management, risk containment, and patient care. We have previously shown a method for ...

Immunohistochemistry Test for the Lyssavirus Antigen Detection from Formalin-Fixed Tissues

One of the primary diagnostic modalities for rabies is the detection of viral ribonucleoprotein (RNP) complex (antigen) in the infected tissue samples. While the direct fluorescent antibody (DFA) test or the direct rapid immunohistochemical test (DRIT) are most commonly utilized for the antigen detection, both tests require fresh and/or frozen tissues for impressions on slides prior to the antigen detection using antibodies. If samples are collected and fixed in formalin, neither test is optimal for the antigen detection, however, testing can be performed by conventional immunohistochemistry (IHC) after embedding in paraffin blocks and sectioning. With this IHC method, tissues are stained with anti-rabies antibodies, sections are deparaffinized, antigen retrieved by partial proteolysis or other methods, and incubated with primary and secondary antibodies. Antigens are stained using horseradish peroxidase / amino ethyl carbazole and counterstained with hematoxylin for the visualization using a light microscope. In addition to the specific antigen detection, formalin fixation offers other advantages like the determination of histological changes, relaxed conditions for specimen storage and transport (under ambient temperatures), ability to test retrospective cases and improved biological safety through the inactivation of infectious agents.

Here, we present an immunohistochemistry test protocol for the detection of rabies virus antigen as an alternative diagnostic test for formalin-fixed tissues.

Prueba de inmunohistoquímica para la detección de antígenos de lisavirus en tejidos fijos de formalina

One of the primary diagnostic modalities for rabies is the detection of viral ribonucleoprotein (RNP) complex (antigen) in the infected tissue samples. ...

Visualization of Pseudomonas aeruginosa within the Sputum of Cystic Fibrosis Patients

Early detection and eradication of Pseudomonas aeruginosa within the lungs of cystic fibrosis patients can reduce the chance of developing chronic infection. The development of chronic P. aeruginosa infections is associated with a decline in lung function and increased morbidity. Therefore, there is a great interest in elucidating the reasons for the failure to eradicate P. aeruginosa with antibiotic therapy which occurs in approximately 10-40% of pediatric patients. One of many factors that can affect host clearance of P. aeruginosa and antibiotic susceptibility is variations in spatial organization (such as aggregation or biofilm formation) and polysaccharide production. Therefore, we were interested in visualizing the in situ characteristics of P. aeruginosa within the sputum of CF patients. A tissue clearing technique was applied to sputum samples after embedding the samples into a hydrogel matrix to retain the 3D structures relative to host cells. After tissue clearing, fluorescent labels and dyes were added to allow visualization. Fluorescence in situ hybridization was performed for the visualization of bacterial cells, binding of fluorescently labeled anti-Psl-antibodies for the visualization of the exopolysaccharide and DAPI staining to stain host cells to obtain structural insight. These methods allowed for the high-resolution imaging of P. aeruginosa within the sputum of CF patients via confocal laser scanning microscopy.

Visualization of Pseudomonas aeruginosa within the Sputum of Cystic Fibrosis Patients

This protocol provides methods for visualization of bacterial cells and polysaccharide synthesis locus (Psl) polysaccharide within the sputum of cystic fibrosis patients.

Visualización de Pseudomonas aeruginosa en el esputo de pacientes con fibrosis quística

Early detection and eradication of Pseudomonas aeruginosa within the lungs of cystic fibrosis patients can reduce the chance of developing chronic ...

Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi

Introducing foreign DNA into the spirochete Borrelia burgdorferi has been almost exclusively accomplished by transformation using electroporation. This process has notably lower efficiencies in the Lyme disease spirochete relative to other, better-characterized Gram-negative bacteria. The rate of success of transformation is highly dependent upon having concentrated amounts of high-quality DNA from specific backgrounds and is subject to significant strain-to-strain variability. Alternative means for introducing foreign DNA (i.e., shuttle vectors, fluorescent reporters, and antibiotic-resistance markers) into B. burgdorferi could be an important addition to the armamentarium of useful tools for the genetic manipulation of the Lyme disease spirochete. Bacteriophage have been well-recognized as natural mechanisms for the movement of DNA among bacteria in a process called transduction. In this study, a method has been developed for using the ubiquitous borrelial phage &#966;BB-1 to transduce DNA between B. burgdorferi cells of both the same and different genetic backgrounds. The transduced DNA includes both borrelial DNA and heterologous DNA in the form of small shuttle vectors. This demonstration suggests a potential use of phage-mediated transduction as a complement to electroporation for the genetic manipulation of the Lyme disease spirochete. This report describes methods for the induction and purification of phage &#966;BB-1 from B. burgdorferi, the use of this phage in transduction assays, and the selection and screening of potential transductants.

Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi

The ability of bacteriophage to move DNA between bacterial cells makes them effective tools for the genetic manipulation of their bacterial hosts. Presented here is a methodology for inducing, recovering, and using &#966;BB-1, a bacteriophage of Borrelia burgdorferi, to transduce heterologous DNA between different strains of the Lyme disease spirochete.

Manipulación genética mediada por fagos de la enfermedad de Lyme Espiroqueta Borrelia burgdorferi

Introducing foreign DNA into the spirochete Borrelia burgdorferi has been almost exclusively accomplished by transformation using electroporation. This ...

Cuantificación de anticuerpos neutralizantes inducidos por vacunas en variantes del SARS-CoV-2

Application of Ha-CoV-2 Pseudovirus for Rapid Quantification of SARS-CoV-2 Variants and Neutralizing Antibodies

The coronavirus disease 2019 pandemic (COVID-19) has highlighted the need for rapid assays to accurately measure the infectivity of emerging SARS-CoV-2 variants and the effectiveness of vaccine-induced neutralizing antibodies against viral variants. These assays are essential for pandemic surveillance and validating vaccines and variant-specific boosters. This manuscript demonstrates the application of a novel hybrid alphavirus-SARS-CoV-2 pseudovirus (Ha-CoV-2) for quick quantification of SARS-CoV-2 variant infectivity and vaccine-induced neutralizing antibodies to viral variants. Ha-CoV-2 is a SARS-CoV-2 virus-like particle consisting of viral structural proteins (S, M, N, and E) and a fast-expressing RNA genome derived from an alphavirus, Semliki Forest Virus (SFV). Ha-CoV-2 also contains both green fluorescent protein (GFP) and luciferase reporter genes that allow for quick quantification of viral infectivity. As an example, the infectivity of the SARS-CoV-2 Delta (B.1.617.2) and the Omicron (B.1.1.529) variants are quantified, and their sensitivities to a neutralizing antibody (27VB) are also measured. These examples demonstrate the great potential of Ha-CoV-2 as a robust platform for rapid quantification of SARS-CoV-2 variants and their susceptibility to neutralizing antibodies.

Autor destacado: Un sistema de virus de pseudotipo para evaluar las subvariantes de ómicron y neutralizar los anticuerpos en la investigación del SARS-CoV-2

This protocol describes the application of a novel hybrid alphavirus-SARS-CoV-2 pseudovirus (Ha-CoV-2) as a platform for rapid quantification of infectivity of SARS-CoV-2 variants and their sensitivity to neutralizing antibodies.

Aplicación del pseudovirus Ha-CoV-2 para la cuantificación rápida de variantes del SARS-CoV-2 y anticuerpos neutralizantes

The coronavirus disease 2019 pandemic (COVID-19) has highlighted the need for rapid assays to accurately measure the infectivity of emerging SARS-CoV-2 ...