This work was supported by National Institutes of Health grants HL105947-01 (YL), HL07829-16 (AM), HL090152 (AM).

Los experimentos con animales fueron aprobados por el Comité de Protección de los Animales y de los Comités Institucionales de Bioseguridad de la Universidad de Illinois en Chicago. NOTA: Todos los procedimientos que involucran pseudomonas deben realizarse con nivel de bioseguridad 2 (BSL2) prácticas, que incluyen pero no se limitan a: la máscara, protección para los ojos, bata o mono, y guantes dobles. Trabajar en la certificación de Bioseguridad gabinete. Tratar a los instrumentos en contacto con las bacterias con desinfectante a base de lejía o cloro dióxido. Use una caja sellada para muestras de transporte. 1. P. aeruginosa cultura y Crecimiento <ol><li> Tienda P. aeruginosa PA103 como una acción bacteriana en un tapón de rosca criovial a -80 ° C. </li><li> Coloque el vial en un estante en una caja con un 70% de etanol mojado toallas de papel y llevarlo al laboratorio de Bioseguridad Nivel 2 (BSL2). </li><li> Racha de las bacterias sobre placas de agar sangre de oveja y crecen a 37 ° C durante ~ 15 horas en una incubadora. </li&gt; <li> En una campana BSL2, rayar las bacterias de la placa con el lazo bacterias y volver a suspender en 5 ml de PBS. </li><li> Guarde el archivo a 4 ° C durante un máximo de 3 meses. Sin embargo, determinar el título cada 2 semanas. </li><li> En serie diluir las bacterias en PBS (por lo general de 1:10 a 1:10 4 7) y la placa de la dilución conocida en placas de agar sangre de oveja. </li><li> Incubar las placas durante ~ 15 h. Recuento de las colonias y calcular formadoras de colonias Unidad (CFU) para determinar la concentración de bacterias. </li><li> Resuspender las concentraciones apropiadas (~ 5 x 10 3 UFC / l) en 0,5 ml de PBS en 1,5 ml crioviales estériles con tapón de rosca. Selle los crioviales y colocarlos en un estante criovial en desinfectantes toallas de papel cargado en una caja de tapa a presión. </li><li> Transporte el cuadro de instalación para animales BSL2. Una vez allí, abrir la caja en el armario BSL2. </li></ol> 2. P. aeruginosa instilación <ol><li> Lleve a cabo la cirugía aséptica supervivencia (guantes estériles, instrumentos estérilesy técnicas asépticas). Utilice un paño estéril para proporcionar una superficie de trabajo para (autoclave) los instrumentos quirúrgicos estériles. Esterilizar los instrumentos utilizando un esterilizador de cuentas caliente entre cada procedimiento de instilación traqueal. </li><li> Pesar los ratones antes de la anestesia. Anestesiar a los ratones con ketamina (100 mg / kg), xilazina (5 mg / kg), en 0,1-0,2 ml de PBS por vía intraperitoneal (ip). Determinar la eficacia de la anestesia por la falta de respuesta al pellizco del dedo del pie. Use un ungüento veterinario en los ojos para evitar la sequedad bajo anestesia. </li><li> Restringir los ratones en un tablero quirúrgico en el gabinete BSL2. </li><li> Identificar el área para el corte hacia abajo. Afeitado esta área y preparar la piel con 3 veces alternando con el alcohol y povidona hisopos de yodo. </li><li> Tratar el área de la incisión con anestesia local (lidocaína), ya que la anestesia es suficiente para una cirugía menor, tales como una incisión en la piel para acceder a la tráquea. </li><li> Haga una pequeña incisión (aproximadamente 5 mm) en la línea media del cuello, y el uso de f romaorceps para mover suavemente el músculo para el acceso a la tráquea. Exponer la tráquea por la disección quirúrgica. </li><li> Dibuje solución de bacterias en una jeringa desechable de 1 ml con aguja 27 G. Para cada ratón, administrar 20-30 l de bacterias a la concentración apropiada (hasta 10 5 CFU cada ratón). </li><li> Insertar la aguja en la tráquea. Inyectar la solución lentamente en el traqueal. </li><li> Asegúrese de que los jadeos de los animales, que por lo general indica que la solución ha alcanzado en el pulmón. </li><li> Cierre la herida con suturas estériles (6-0 monofilamento) en condiciones asépticas. </li><li> Utilice 0,1 mg / kg de buprenorfina por inyección subcutánea como post-op analgesia para controlar el dolor post-quirúrgico. </li><li> Asegúrese de que el tiempo requerido desde la inducción anestésica inicial a la incisión de cierre es inferior a 15 min. </li><li> Después de la inyección, desechar las jeringas y agujas en un recipiente previsto apropiado. </li><li> Tratar a los instrumentos quirúrgicos con DISI basado dióxido de cloronfectant durante 15 minutos, enjuagar y volver al laboratorio para su esterilización y reutilizar cuando sea necesario. </li><li> La casa de los ratones individualmente en jaulas limpias en ambiente cálido. </li><li> Compruebe en el animal cada 30 minutos hasta que se recupera la conciencia y empieza a moverse; y posteriormente a intervalos de 12 h durante los primeros 3 días después de la cirugía. </li><li> Mantener los ratones en las instalaciones de BSL2 animales durante todo el experimento. Asegúrese de que sólo el tejido contenido en la caja sellada salgan de la instalación BSL2 animal. Si los ratones expresan cualquiera de los comportamientos moribundas (definido como dificultad respiratoria, letargo, falta de deambular en respuesta a la estimulación suave) en cualquier punto en el estudio, la eutanasia a los ratones mediante inhalación de CO2 de una fuente embotellada seguido por dislocación cervical. </li><li> La eutanasia el sujeto experimental por desangrado bajo anestesia. <ol><li> Recoger el tejido pulmonar de los ratones sacrificados. Llevar a cabo estos procedimientos en una capucha BSL2. Si es necesario, transferir la muestra utilizando tubos sellados colocados en un rack en desinfectantes toallas de papel cargado en una caja de tapa a presión para su posterior proceso. </li></ol></li></ol>

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	<li>Ware, L. B., Matthay, M. 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+acute+respiratory+distress+syndrome.">The acute respiratory distress syndrome.</a> N Engl J Med. 342, 1334-1349 (2000).</li><li>Matthay, M. A., Ware, L. B., Zimmerman, G. 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+acute+respiratory+distress+syndrome.">The acute respiratory distress syndrome.</a> J Clin Invest. 122, 2731-2740 (2012).</li><li>Shimabukuro, D. W., Sawa, T., Gropper, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Injury+and+repair+in+lung+and+airways.">Injury and repair in lung and airways.</a> Crit Care Med. 31 (8), 524-531 (2003).</li><li>Wansleeben, C., Barkauskas, C. E., Rock, J. R., Hogan, B. 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The authors have nothing to disclose.

El modelo de lesión pulmonar por Pseudomonas ratón que describimos aquí imita todo el proceso de la inflamación, lesión pulmonar, la reparación, y la resolución que se producen después de una lesión pulmonar aguda o neumonía. Tiene ventajas únicas en comparación con varios otros modelos de lesión, ya que es clínicamente relevante y relativamente seguro y fácil de manejar. El paso crítico en el procedimiento es que la inyección de solución de bacterias tiene que ser muy lent...

Los pulmones están expuestos a los patógenos ambientales y son susceptibles a la inflamación y lesión de 1-3. Durante condiciones patológicas tales como la neumonía o síndrome de distrés respiratorio del adulto (SDRA), patógenos, así como los factores inflamatorios liberados por los leucocitos inducen lesiones y la muerte de las células alveolares 1-3. Es importante desarrollar modelos animales de lesión pulmonar aguda para facilitar el estudio de la patología de la lesión, así como mecanismo de reparación. En la actualidad, la mayoría de las personas utilizan modelos de lesión pulmonar hyperoxia y bleomicina ratón inducida 4. Sin embargo, los mecanismos de hiperoxia causaron daño no son los mismos que la mayoría de las lesiones pulmonares comunes que se producen durante la neumonía o el SDRA 5. La bleomicina lesión aguda inducida es raro en un contexto clínico 4. Aquí mostramos un modelo de lesión pulmonar de ratón utilizando la inyección intra-traqueal de P. aeruginosa 6,7. Este modelo es clínicamente relevante, e imita el procesos que suceden después de la neumonía 8. Como un patógeno oportunista, nosocomial de individuos inmunocomprometidos, P. aeruginosa típicamente infecta el tracto pulmonar, tracto urinario, quemaduras, heridas, y también causa otras infecciones de sangre 6. Las bacterias liberan factor de virulencia exotoxina A, se multiplican y desencadenan respuestas inmunes 6. Administración intra-de la tráquea de P. aeruginosa refleja la situación en la exposición humana a las bacterias que causan la neumonía y la patología es probable que sea diferente del modelo de lesión informado recientemente de virus de la gripe H1N1 pulmonar inducida 9. Desde P. aeruginosa es un patógeno oportunista, es relativamente seguro de manejar en comparación con algunos de los patógenos más virulentas. Aquí hemos utilizado la inyección intra-traqueal para administrar las bacterias porque se observó que este método introduce más bacterias en la región distal alvéolos del pulmón en comparación conalgunos otros procedimientos, tales como el uso de un catéter a través de la boca. En comparación con otros modelos de lesión pulmonar aguda, la P. aeruginosa modelo aquí descrito es adecuado para el estudio de la lesión pulmonar inducida por bacterias y por la inflamación excesiva. A diferencia de otros modelos animales que utilizan P. aeruginosa para inducir la sepsis 10,11, aquí utilizamos la inyección intra-traqueal de estas bacterias para inducir la lesión pulmonar aguda localizada.

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			<td height="26" style="height:27px;width:215px;">Name</td>
			<td style="width:145px;">Company</td>
			<td style="width:145px;">Catalog number&#160;</td>
			<td style="width:145px;">Comments</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:215px;">Anesthetic: Ketamin, xylazine, lidocaine, buprenorphine</td>
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			<td style="width:145px;">pharmaceutical grade</td>
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			<td height="26" style="height:27px;width:215px;">27g needle</td>
			<td style="width:145px;">Fisher</td>
			<td style="width:145px;">1482648</td>
			<td style="width:145px;"></td>
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		<tr height="26">
			<td height="26" style="height:27px;width:215px;">syringe</td>
			<td style="width:145px;">Fisher</td>
			<td style="width:145px;">14823434</td>
			<td style="width:145px;">1 ml</td>
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		<tr height="26">
			<td height="26" style="height:27px;width:215px;">scissors</td>
			<td style="width:145px;">Fine Science tools</td>
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			<td style="width:145px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:215px;">forceps</td>
			<td style="width:145px;">Fine Science tools</td>
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			<td style="width:145px;"></td>
		</tr>
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			<td height="26" style="height:27px;width:215px;">suture&#160;</td>
			<td style="width:145px;">Fisher</td>
			<td style="width:145px;">NC0147607</td>
			<td style="width:145px;"></td>
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		<tr height="26">
			<td height="26" style="height:27px;">Eye gauge, glove, gown</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;">Biosafety Cabinet</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;">chlorine dioxide based sterilant&#160;</td>
			<td></td>
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			<td>Clidox</td>
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			<td height="26" style="height:27px;">sheep blood agar plates&#160;</td>
			<td>Medex supply</td>
			<td>HL-1160</td>
			<td></td>
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pseudomonas aeruginosa induced lung injury model

Con el fin de estudiar la lesión pulmonar aguda humana y la neumonía, es importante desarrollar modelos animales para imitar varias características patológicas de esta enfermedad. Aquí hemos desarrollado un modelo de lesión de pulmón de ratón mediante inyección intra-traqueal de bacterias Pseudomonas aeruginosa (P. aeruginosa o PA). Utilizando este modelo, hemos sido capaces de mostrar la inflamación pulmonar en la fase temprana de la lesión. Además, la barrera epitelial alveolar leakiness se observó mediante el análisis de lavado broncoalveolar (BAL); y la muerte celular alveolar se observó mediante el ensayo Tunel utilizando tejido preparado a partir de pulmones lesionados. En una fase posterior después de una lesión, se observó la proliferación de células requerido para el proceso de reparación. La lesión se resolvió 7 días desde el inicio de P. inyección aeruginosa. Este modelo imita el curso secuencial de la inflamación pulmonar, daño y reparación durante la neumonía. Este modelo animal clínicamente relevante es adecuado para el estudio de la patología, el mecanismo de reparación, fespués de la lesión pulmonar aguda, y también puede ser utilizado para probar agentes terapéuticos potenciales para esta enfermedad.

A partir de 24 a 72 h después de P. inyección aeruginosa, aumento de la celularidad se observó en secciones de pulmón (Figura 1A-D). El pulmón comenzó a recuperarse a partir de 96 horas después de la lesión (Figura 1E). A los 7 días después de la P. aeruginosa, la morfología normal de los alvéolos fue restaurada en gran medida (Figura 1F). Tinción Túnel secciones usando pulmonares prepararon a 24 h después de P. aeruginosa</...

Watch this Scientific Journal Video about Pseudomonas aeruginosa Induced Lung Injury Model at JoVE.com

Pseudomonas aeruginosa Induced Lung Injury Model

We have developed a mouse lung injury model by intra-tracheal injection of bacteria Pseudomonas aeruginosa. This model mimics lung injury during pneumonia and is clinically relevant.

Pseudomonas aeruginosa inducida por la lesión pulmonar Modelo

In order to study human acute lung injury and pneumonia, it is important to develop animal models to mimic various pathological features of this disease. ...

pseudomonas-aeruginosa-induced-lung-injury-model

Research

JoVE Journal

Immunology and Infection

Pseudomonas aeruginosa Induced Lung Injury Model

18.4K vistas.  University of Illinois at Chicago. We have developed a mouse lung injury model by intra-tracheal injection of bacteria Pseudomonas aeruginosa. This model mimics lung injury during pneumonia and is clinically relevant. 

Video: Pseudomonas aeruginosa Induced Lung Injury Model

Co-culture Models of Pseudomonas aeruginosa Biofilms Grown on Live Human Airway Cells

Bacterial biofilms have been associated with a number of different human diseases, but biofilm development has generally been studied on non-living surfaces. In this paper, we describe protocols for forming Pseudomonas aeruginosa biofilms on human airway epithelial cells (CFBE cells) grown in culture. In the first method (termed the Static Co-culture Biofilm Model), P. aeruginosa is incubated with CFBE cells grown as confluent monolayers on standard tissue culture plates. Although the bacterium is quite toxic to epithelial cells, the addition of arginine delays the destruction of the monolayer long enough for biofilms to form on the CFBE cells. The second method (termed the Flow Cell Co-culture Biofilm Model), involves adaptation of a biofilm flow cell apparatus, which is often used in biofilm research, to accommodate a glass coverslip supporting a confluent monolayer of CFBE cells. This monolayer is inoculated with P. aeruginosa and a peristaltic pump then flows fresh medium across the cells. In both systems, bacterial biofilms form within 6-8 hours after inoculation. Visualization of the biofilm is enhanced by the use of P. aeruginosa strains constitutively expressing green fluorescent protein (GFP). The Static and Flow Cell Co-culture Biofilm assays are model systems for early P. aeruginosa infection of the Cystic Fibrosis (CF) lung, and these techniques allow different aspects of P. aeruginosa biofilm formation and virulence to be studied, including biofilm cytotoxicity, measurement of biofilm CFU, and staining and visualizing the biofilm.

Co-culture Models of Pseudomonas aeruginosa Biofilms Grown on Live Human Airway Cells

This paper describes different methods of growing Pseudomonas aeruginosa biofilms on cultured human airway epithelial cells. These protocols can be adapted to study different aspects of biofilm formation, including visualization of the biofilm, staining of the biofilm, measuring the colony forming units (CFU) of the biofilm, and studying biofilm cytotoxicity.

Los modelos de co-cultivo de Pseudomonas aeruginosa Biofilms Cultivado en las células vivas las vías respiratorias humanas

Bacterial biofilms have been associated with a number of different human diseases, but biofilm development has generally been studied on non-living ...

Investigación

Inmunología e Infección

Pseudomonas aeruginosa and Saccharomyces cerevisiae Biofilm in Flow Cells

Many microbial cells have the ability to form sessile microbial communities defined as biofilms that have altered physiological and pathological properties compared to free living microorganisms. Biofilms in nature are often difficult to investigate and reside under poorly defined conditions1. Using a transparent substratum it is possible to device a system where simple biofilms can be examined in a non-destructive way in real-time: here we demonstrate the assembly and operation of a flow cell model system, for in vitro 3D studies of microbial biofilms generating high reproducibility under well-defined conditions2,3.
The system consists of a flow cell that serves as growth chamber for the biofilm. The flow cell is supplied with nutrients and oxygen from a medium flask via a peristaltic pump and spent medium is collected in a waste container. This construction of the flow system allows a continuous supply of nutrients and administration of e.g. antibiotics with minimal disturbance of the cells grown in the flow chamber. Moreover, the flow conditions within the flow cell allow studies of biofilm exposed to shear stress. A bubble trapping device confines air bubbles from the tubing which otherwise could disrupt the biofilm structure in the flow cell.
The flow cell system is compatible with Confocal Laser Scanning Microscopy (CLSM) and can thereby provide highly detailed 3D information about developing microbial biofilms. Cells in the biofilm can be labeled with fluorescent probes or proteins compatible with CLSM analysis. This enables online visualization and allows investigation of niches in the developing biofilm. Microbial interrelationship, investigation of antimicrobial agents or the expression of specific genes, are of the many experimental setups that can be investigated in the flow cell system.

Pseudomonas aeruginosa and Saccharomyces cerevisiae Biofilm in Flow Cells

Protocol describing the application of a flow cell system for growing and analyzing microbial biofilms for Confocal Laser Scanning Microscopy (CLSM).

Pseudomonas aeruginosa y Biofilm Saccharomyces cerevisiae en las celdas de flujo

Many microbial cells have the ability to form sessile microbial communities defined as biofilms that have altered physiological and pathological ...

RNA Isolation of Pseudomonas aeruginosa Colonizing the Murine Gastrointestinal Tract

Pseudomonas aeruginosa (PA) infections result in significant morbidity and mortality in hosts with compromised immune systems, such as patients with leukemia, severe burn wounds, or organ transplants1. In patients at high-risk for developing PA bloodstream infections, the gastrointestinal (GI) tract is the main reservoir for colonization2, but the mechanisms by which PA transitions from an asymptomatic colonizing microbe to an invasive, and often deadly, pathogen are unclear. Previously, we performed in vivo transcription profiling experiments by recovering PA mRNA from bacterial cells residing in the cecums of colonized mice 3 in order to identify changes in bacterial gene expression during alterations to the host&#x2019;s immune status.
As with any transcription profiling experiment, the rate-limiting step is in the isolation of sufficient amounts of high quality mRNA. Given the abundance of enzymes, debris, food residues, and particulate matter in the GI tract, the challenge of RNA isolation is daunting. Here, we present a method for reliable and reproducible isolation of bacterial RNA recovered from the murine GI tract. This method utilizes a well-established murine model of PA GI colonization and neutropenia-induced dissemination4. Once GI colonization with PA is confirmed, mice are euthanized and cecal contents are recovered and flash frozen. RNA is then extracted using a combination of mechanical disruption, boiling, phenol/chloroform extractions, DNase treatment, and affinity chromatography. Quantity and purity are confirmed by spectrophotometry (Nanodrop Technologies) and bioanalyzer (Agilent Technologies) (Fig 1). This method of GI microbial RNA isolation can easily be adapted to other bacteria and fungi as well.

RNA Isolation of Pseudomonas aeruginosa Colonizing the Murine Gastrointestinal Tract

A reliable method for the RNA isolation of Pseudomonas aeruginosa recovered from murine cecums is described. The RNA recovered is of sufficient quantity and quality for subsequent qPCR, transcription profiling, and RNA Seq experiments. This technique can be adapted for RNA isolation of other intestinal microbes.

El aislamiento de ARN Pseudomonas aeruginosa Que colonizan el tracto gastrointestinal murino

Pseudomonas aeruginosa (PA) infections result in significant morbidity and mortality in hosts with compromised immune systems, such as patients with ...

Use of Artificial Sputum Medium to Test Antibiotic Efficacy Against Pseudomonas aeruginosa in Conditions More Relevant to the Cystic Fibrosis Lung

There is growing concern about the relevance of in vitro antimicrobial susceptibility tests when applied to isolates of P. aeruginosa from cystic fibrosis (CF) patients. Existing methods rely on single or a few isolates grown aerobically and planktonically. Predetermined cut-offs are used to define whether the bacteria are sensitive or resistant to any given antibiotic1. However, during chronic lung infections in CF, P. aeruginosa populations exist in biofilms and there is evidence that the environment is largely microaerophilic2. The stark difference in conditions between bacteria in the lung and those during diagnostic testing has called into question the reliability and even relevance of these tests3.
 Artificial sputum medium (ASM) is a culture medium containing the components of CF patient sputum, including amino acids, mucin and free DNA. P. aeruginosa growth in ASM mimics growth during CF infections, with the formation of self-aggregating biofilm structures and population divergence4,5,6. The aim of this study was to develop a microtitre-plate assay to study antimicrobial susceptibility of P. aeruginosa based on growth in ASM, which is applicable to both microaerophilic and aerobic conditions.
 An ASM assay was developed in a microtitre plate format. P. aeruginosa biofilms were allowed to develop for 3 days prior to incubation with antimicrobial agents at different concentrations for 24 hours. After biofilm disruption, cell viability was measured by staining with resazurin. This assay was used to ascertain the sessile cell minimum inhibitory concentration (SMIC) of tobramycin for 15 different P. aeruginosa isolates under aerobic and microaerophilic conditions and SMIC values were compared to those obtained with standard broth growth. Whilst there was some evidence for increased MIC values for isolates grown in ASM when compared to their planktonic counterparts, the biggest differences were found with bacteria tested in microaerophilic conditions, which showed a much increased resistance up to a &gt;128 fold, towards tobramycin in the ASM system when compared to assays carried out in aerobic conditions.
 The lack of association between current susceptibility testing methods and clinical outcome has questioned the validity of current methods3. Several in vitro models have been used previously to study P. aeruginosa biofilms7, 8. However, these methods rely on surface attached biofilms, whereas the ASM biofilms resemble those observed in the CF lung9 . In addition, reduced oxygen concentration in the mucus has been shown to alter the behavior of P. aeruginosa2 and affect antibiotic susceptibility10. Therefore using ASM under microaerophilic conditions may provide a more realistic environment in which to study antimicrobial susceptibility.

Use of Artificial Sputum Medium to Test Antibiotic Efficacy Against Pseudomonas aeruginosa in Conditions More Relevant to the Cystic Fibrosis Lung

Current diagnostic antimicrobial susceptibility testing relies on the planktonic growth of isolates in nutrient rich, aerobic conditions. Here, we employ an alternative artificial sputum medium to study antimicrobial susceptibility of Pseudomonas aeruginosa biofilms under both aerobic and microaerophilic conditions more representative of the cystic fibrosis lung.

Uso de un medio artificial de esputo para probar la eficacia de antibióticos contra la<em&gt; Pseudomonas aeruginosa</em&gt; En condiciones más pertinentes a la fibrosis quística pulmonar

There  is growing concern about the relevance of in vitro antimicrobial  susceptibility tests when applied to isolates of P. aeruginosa from  cystic ...

Long Term Chronic Pseudomonas aeruginosa Airway Infection in Mice

A mouse model of chronic airway infection is a key asset in cystic fibrosis (CF) research, although there are a number of concerns regarding the model itself. Early phases of inflammation and infection have been widely studied by using the Pseudomonas aeruginosa agar-beads mouse model, while only few reports have focused on the long-term chronic infection in vivo. The main challenge for long term chronic infection remains the low bacterial burden by P. aeruginosa and the low percentage of infected mice weeks after challenge, indicating that bacterial cells are progressively cleared by the host.
This paper presents a method for obtaining efficient long-term chronic infection in mice. This method is based on the embedding of the P. aeruginosa clinical strains in the agar-beads in vitro, followed by intratracheal instillation in C57Bl/6NCrl mice. Bilateral lung infection is associated with several measurable read-outs including weight loss, mortality, chronic infection, and inflammatory response. The P. aeruginosa RP73 clinical strain was preferred over the PAO1 reference laboratory strain since it resulted in a comparatively lower mortality, more severe lesions, and higher chronic infection. P. aeruginosa colonization may persist in the lung for over three months. Murine lung pathology resembles that of CF patients with advanced chronic pulmonary disease.
This murine model most closely mimics the course of the human disease and can be used both for studies on the pathogenesis and for the evaluation of novel therapies.

Long Term Chronic Pseudomonas aeruginosa Airway Infection in Mice

We describe the agar-beads method to establish persistent long-term chronic Pseudomonas aeruginosa airway infection in the mouse model.

Crónica a largo plazo<em&gt; Pseudomonas aeruginosa</em&gt; Infección de las vías respiratorias en los ratones

A mouse model of chronic airway infection is a key asset in cystic fibrosis (CF) research, although there are a number of concerns regarding the model ...

Replication of the Ordered, Nonredundant Library of Pseudomonas aeruginosa strain PA14 Transposon Insertion Mutants

Pseudomonas aeruginosa is a phenotypically and genotypically diverse and adaptable Gram-negative bacterium ubiquitous in human environments. P. aeruginosa is able to form biofilms, develop antibiotic resistance, produce virulence factors, and rapidly evolve in the course of a chronic infection. Thus P. aeruginosa can cause both acute and chronic, difficult to treat infections, resulting in significant morbidity in certain patient populations. P. aeruginosa strain PA14 is a human clinical isolate with a conserved genome structure that infects a variety of mammalian and nonvertebrate hosts making PA14 an attractive strain for studying this pathogen. In 2006, a nonredundant transposon insertion mutant library containing 5,459 mutants corresponding to 4,596 predicted PA14 genes was generated. Since then, distribution of the PA14 library has allowed the research community to better understand the function of individual genes and complex pathways of P. aeruginosa. Maintenance of library integrity through the replication process requires proper handling and precise techniques. To that end, this manuscript presents protocols that describe in detail the steps involved in library replication, library quality control and proper storage of individual mutants.

Replication of the Ordered, Nonredundant Library of Pseudomonas aeruginosa strain PA14 Transposon Insertion Mutants

Pseudomonas aeruginosa infection causes significant morbidity in vulnerable hosts. The nonredundant transposon insertion mutant library of P. aeruginosa strain PA14, designated as PA14NR Set, facilitates analysis of gene functionality in numerous processes. Presented here is a protocol to generate high-quality copies of the PA14NR Set mutant library.

Replicación de la ordena, no redundante biblioteca de Pseudomonas aeruginosa cepa PA14 mutantes de inserción de transposones

Pseudomonas aeruginosa is a phenotypically and genotypically diverse and adaptable Gram-negative bacterium ubiquitous in human environments. P. aeruginosa ...

Methods for Detecting Cytotoxic Amyloids Following Infection of Pulmonary Endothelial Cells by Pseudomonas aeruginosa

Patients who survive pneumonia have elevated death rates in the months following hospital discharge. It has been hypothesized that infection of pulmonary tissue during pneumonia results in the production of long-lived cytotoxins that can lead to subsequent end organ failure. We have developed in vitro assays to test the hypothesis that cytotoxins are produced during pulmonary infection. Isolated rat pulmonary endothelial cells and the bacterium Pseudomonas aeruginosa are used as model systems, and the production of cytoxins following infection of the endothelial cells by the bacteria is demonstrated using cell culture followed by direct quantitation using lactate dehydrogenase assays and a novel microscopic method utilizing ImageJ technology. The amyloid nature of these cytotoxins was demonstrated by thioflavin T binding assays and by immunoblotting and immunodepletion using A11 anti-amyloid antibody. Further analyses using immunoblotting demonstrated that oligomeric tau and A&#946; were produced and released by endothelial cells following infection by P. aeruginosa. These methods should be readily adaptable to analyses of human clinical samples.

Methods for Detecting Cytotoxic Amyloids Following Infection of Pulmonary Endothelial Cells by Pseudomonas aeruginosa

Simple methods are described for demonstrating the production of cytotoxic amyloids following infection of pulmonary endothelium by Pseudomonas aeruginosa.

Métodos para la detección de amiloides siguiente infección de pulmonar endotelial células citotóxicas por Pseudomonas aeruginosa

Patients who survive pneumonia have elevated death rates in the months following hospital discharge. It has been hypothesized that infection of pulmonary ...

Generation of In-Frame Gene Deletion Mutants in Pseudomonas aeruginosa and Testing for Virulence Attenuation in a Simple Mouse Model of Infection

Microorganisms are genetically versatile and diverse and have become a major source of many commercial products and biopharmaceuticals. Though some of these products are naturally produced by the organisms, other products require genetic engineering of the organism to increase the yields of production. Avirulent strains of Escherichia coli have traditionally been the preferred bacterial species for producing biopharmaceuticals; however, some products are difficult for E. coli to produce. Thus, avirulent strains of other bacterial species could provide useful alternatives for production of some commercial products. Pseudomonas aeruginosa is a common and well-studied Gram-negative bacterium that could provide a suitable alternative to E. coli. However, P. aeruginosa is an opportunistic human pathogen. Here, we detail a procedure that can be used to generate nonpathogenic strains of P. aeruginosa through sequential genomic deletions using the pEX100T-NotI plasmid. The main advantage of this method is to produce a marker-free strain. This method may be used to generate highly attenuated P. aeruginosa strains for the production of commercial products, or to design strains for other specific uses. We also describe a simple and reproducible mouse model of bacterial systemic infection via intraperitoneal injection of validated test strains to test the attenuation of the genetically engineered strain in comparison to the FDA-approved BL21 strain of E. coli.

Generation of In-Frame Gene Deletion Mutants in Pseudomonas aeruginosa and Testing for Virulence Attenuation in a Simple Mouse Model of Infection

Here, we describe a simple and reproducible protocol of mouse model of infection to evaluate the attenuation of the genetically modified strains of Pseudomonas aeruginosa in comparison to the United States Food and Drug Administration (FDA)-approved Escherichia coli for commercial applications.

Generación de mutantes de eliminación de genes en el marco en Pseudomonas aeruginosa y pruebas para la atenuación de la virulencia en un modelo simple de infección de ratón

Microorganisms are genetically versatile and diverse and have become a major source of many commercial products and biopharmaceuticals. Though some of ...

Culture of Small Colony Variant of Pseudomonas aeruginosa and Quantitation of its Alginate

Pseudomonas aeruginosa, an opportunistic Gram-negative bacterial pathogen, can overproduce an exopolysaccharide alginate resulting in a unique phenotype called mucoidy. Alginate is linked to chronic lung infections resulting in poor prognosis in patients with cystic fibrosis (CF). Understanding the pathways that regulate the production of alginate can aid in the development of novel therapeutic strategies targeting the alginate formation. Another disease-related phenotype is the small colony variant (SCV). SCV is due to the slow growth of bacteria and often associated with increased resistance to antimicrobials. In this paper, we first show a method of culturing a genetically defined form of P. aeruginosa SCV due to pyrimidine biosynthesis mutations. Supplementation of nitrogenous bases, uracil or cytosine, returns the normal growth to these mutants, demonstrating the presence of a salvage pathway that scavenges free bases from the environment. Next, we discuss two methods for the measurement of bacterial alginate. The first method relies on the hydrolysis of the polysaccharide to its uronic acid monomer followed by derivatization with a chromogenic reagent, carbazole, while the second method uses an ELISA based on a commercially available, alginate-specific mAb. Both methods require a standard curve for quantitation. We also show that the immunological method is specific for alginate quantification and may be used for the measurement of alginate in the clinical specimens.

Culture of Small Colony Variant of Pseudomonas aeruginosa and Quantitation of its Alginate

Here, we describe a growth condition to culture the small colony variant of Pseudomonas aeruginosa. We also describe two separate methods for the detection and quantitation of the exopolysaccharide alginate produced by P. aeruginosa using a traditional uronic acid carbazole assay and an alginate-specific monoclonal antibody (mAb) based ELISA.

Cultivo de la Pequeña Colonia Variante de Pseudomonas aeruginosa y Cantidad de su Alginato

Pseudomonas aeruginosa, an opportunistic Gram-negative bacterial pathogen, can overproduce an exopolysaccharide alginate resulting in a unique phenotype ...

A Delayed Inoculation Model of Chronic Pseudomonas aeruginosa Wound Infection

Pseudomonas aeruginosa (P. aeruginosa) is a major nosocomial pathogen of increasing relevance to human health and disease, particularly in the setting of chronic wound infections in diabetic and hospitalized patients. There is an urgent need for chronic infection models to aid in the investigation of wound pathogenesis and the development of new therapies against this pathogen. Here, we describe a protocol that uses delayed inoculation 24 hours after full-thickness excisional wounding. The infection of the provisional wound matrix present at this time forestalls either rapid clearance or dissemination of infection and instead establishes chronic infection lasting 7&#8211;10 days without the need for implantation of foreign materials or immune suppression. This protocol mimics a typical temporal course of post-operative infection in humans. The use of a luminescent P. aeruginosa strain (PAO1:lux) allows for quantitative daily assessment of bacterial burden for P. aeruginosa wound infections. This novel model may be a useful tool in the investigation of bacterial pathogenesis and the development of new therapies for chronic P. aeruginosa wound infections.

A Delayed Inoculation Model of Chronic Pseudomonas aeruginosa Wound Infection

We describe a delayed inoculation protocol for generating chronic wound infections in immunocompetent mice.

Un modelo de inoculación tardía de la infección crónica por la herida de Pseudomonas aeruginosa

Pseudomonas aeruginosa (P. aeruginosa) is a major nosocomial pathogen of increasing relevance to human health and disease, particularly in the setting of ...