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

Gli esperimenti sugli animali sono stati approvati dal Comitato di cura degli animali e istituzionali biosicurezza Comitati della University of Illinois a Chicago. NOTA: Tutte le procedure che coinvolgono Pseudomonas devono essere eseguite con il livello di biosicurezza 2 (BSL2) pratiche, che includono ma non sono limitate a: maschera, occhiali di protezione, abito o tuta, e due paia di guanti. Lavorare in sicurezza biologica certificata Gabinetto. Trattare gli strumenti in contatto con i batteri con candeggina o biossido di cloro disinfettante a base. Utilizzare una scatola sigillata per i campioni di trasporto. 1. P. aeruginosa cultura e di crescita <ol><li> Negozio P. aeruginosa PA103 come uno stock batterica in un tappo a vite esageratamente a -80 ° C. </li><li> Posizionare la fiala in un rack in una scatola con etanolo al 70% bagnato asciugamani di carta e prendere al laboratorio livello di biosicurezza 2 (BSL2). </li><li> Streak i batteri su piastre di agar sangue di pecora e crescono a 37 ° C per ~ 15 ore in un incubatore. </li&gt; <li> In una cappa BSL2, graffiare i batteri dalla piastra con batteri loop e risospendere in 5 ml di PBS. </li><li> Conservare il titolo a 4 ° C per un massimo di 3 mesi. Tuttavia, determinare il titolo ogni 2 settimane. </li><li> Serialmente diluire i batteri in PBS (di solito da 1:10 a 1:10 4 7) e piastra fuori la diluizione noto su piastre di agar sangue di pecora. </li><li> Incubare le piastre per ~ 15 ore. Contare le colonie e calcolare Colony Forming Unit (CFU) per determinare la concentrazione di batteri. </li><li> Risospendere le concentrazioni appropriate (~ 5 x 10 3 UFC / ml) in 0,5 ml di PBS in 1,5 ml sterili cryovials con tappo a vite. Sigillare i cryovials e metterli in un rack esageratamente sul disinfettante salviette di carta a pieno carico in una scatola coperchio a scatto. </li><li> Trasportare la casella di stabulario BSL2. Una volta lì, aprire la scatola nell&#39;armadio BSL2. </li></ol> 2. P. aeruginosa instillazione <ol><li> Eseguire un intervento chirurgico di sopravvivenza in condizioni asettiche (guanti sterili, strumenti sterili, ed impiegare tecniche asettiche). Utilizzare un telino sterile per fornire un piano di lavoro per la (autoclave) gli strumenti chirurgici sterili. Sterilizzare gli strumenti utilizzando uno sterilizzatore tallone caldo tra ogni instillazione tracheale procedura. </li><li> Pesare i topi prima di anestesia. Anestetizzare topi con ketamina (100 mg / kg), xilazina (5 mg / kg), in 0,1 - 0,2 ml di PBS per via intraperitoneale (ip). Determinare l&#39;efficacia dell&#39;anestetico dalla non rispondenza alle pinch punta. Usare una pomata veterinario sugli occhi per prevenire la secchezza sotto anestesia. </li><li> Trattenere mouse su una scheda chirurgico in armadietto BSL2. </li><li> Identificare l&#39;area per il taglio verso il basso. Radere questo settore e preparare la pelle con alternanza di alcol e tamponi povidone iodio 3 volte. </li><li> Trattare l&#39;area di incisione con anestetico locale (lidocaina) poiché l&#39;anestesia è sufficiente per un intervento chirurgico minore come un incisione cutanea per accedere alla trachea. </li><li> Fai una piccola incisione (circa 5 mm) sulla linea mediana del collo, e l&#39;uso schietto forceps per spostare delicatamente il muscolo per l&#39;accesso alla trachea. Esporre la trachea da dissezione chirurgica. </li><li> Disegna la soluzione di batteri in un 1 ml siringa monouso con ago 27 G. Per ogni mouse, somministrare 20-30 ml di batteri alla concentrazione adeguata (fino a 10 5 CFU ogni mouse). </li><li> Inserire l&#39;ago nella trachea. Iniettare la soluzione lentamente nel tracheale. </li><li> Assicurarsi che i rantoli di animali, che di solito indica che la soluzione ha raggiunto nei polmoni. </li><li> Chiudere la ferita con punti di sutura sterili (6-0 monofilamento) in condizioni asettiche. </li><li> Utilizzare 0,1 mg / kg di buprenorfina per via sottocutanea come post-operatoria analgesia per controllare il dolore postoperatorio. </li><li> Assicurarsi che il tempo richiesto dalla induzione di anestesia prima di incisione di chiusura è inferiore a 15 min. </li><li> Dopo l&#39;iniezione, gettare siringhe e aghi in un apposito contenitore per rischio biologico taglienti. </li><li> Trattare gli strumenti chirurgici con disi a base di biossido di cloronfectant per 15 minuti, risciacquare e tornare al laboratorio per la sterilizzazione e il riutilizzo, se necessario. </li><li> La casa dei topi singolarmente in gabbie pulite in ambiente caldo. </li><li> Controllare sull&#39;animale ogni 30 minuti fino a quando non riprende conoscenza e comincia a muoversi; e in seguito a intervalli di 12 h per i primi 3 giorni dopo l&#39;intervento chirurgico. </li><li> Tenere i topi nella struttura BSL2 animali tutto l&#39;esperimento. Assicurarsi che solo il tessuto contenute in scatola sigillata lasciano l&#39;impianto BSL2 animali. Se i topi esprimono uno dei comportamenti moribondi (definito come distress respiratorio, letargia, incapacità di deambulare in risposta alla stimolazione dolce) in qualsiasi punto dello studio, i topi eutanasia da CO 2 inalazione da una fonte in bottiglia seguita da dislocazione cervicale. </li><li> Euthanize il soggetto sperimentale per dissanguamento in anestesia. <ol><li> Raccogliere tessuto polmonare di topi eutanasia. Eseguire queste procedure in un cappuccio BSL2. Se necessario, trasferire il campione utilizzando tubi sigillati posti in una rack su disinfettanti carta assorbente pieno carico in una scatola coperchio a scatto per un ulteriore processo. </li></ol></li></ol>

<ol>
	<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. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+cells+of+the+adult+lung:+Their+development+and+role+in+homeostasis,+regeneration,+and+disease.">Stem cells of the adult lung: Their development and role in homeostasis, regeneration, and disease.</a> Wiley Interdiscip Rev Dev Biol. 2, 131-148 (2013).</li><li>Singleton, P. A., 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=Dynamin+2+and+c-abl+are+novel+regulators+of+hyperoxia-mediated+nadph+oxidase+activation+and+reactive+oxygen+species+production+in+caveolin-enriched+microdomains+of+the+endothelium.">Dynamin 2 and c-abl are novel regulators of hyperoxia-mediated nadph oxidase activation and reactive oxygen species production in caveolin-enriched microdomains of the endothelium.</a> J Biol Chem. 284, 34964-34975 (2009).</li><li>Sadikot, R. T., Blackwell, T. S., Christman, J. W., Prince, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathogen-host+interactions+in+pseudomonas+aeruginosa+pneumonia.">Pathogen-host interactions in pseudomonas aeruginosa pneumonia.</a> Am J Respir Crit Care Med. 171, 1209-1223 (2005).</li><li>Liu, Y., 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=Foxm1+mediates+the+progenitor+function+of+type+ii+epithelial+cells+in+repairing+alveolar+injury+induced+by+pseudomonas+aeruginosa.">Foxm1 mediates the progenitor function of type ii epithelial cells in repairing alveolar injury induced by pseudomonas aeruginosa.</a> J Exp Med. 208, 1473-1484 (2011).</li><li>Kurahashi, K., 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=Pathogenesis+of+septic+shock+in+pseudomonas+aeruginosa+pneumonia.">Pathogenesis of septic shock in pseudomonas aeruginosa pneumonia.</a> J Clin Invest. 104, 743-750 (1999).</li><li>Kumar, P. A., 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=Distal+airway+stem+cells+yield+alveoli+in+vitro+and+during+lung+regeneration+following+h1n1+influenza+infection.">Distal airway stem cells yield alveoli in vitro and during lung regeneration following h1n1 influenza infection.</a> Cell. 147, 525-538 (2011).</li><li>Delano, M. 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=Sepsis+induces+early+alterations+in+innate+immunity+that+impact+mortality+to+secondary+infection.">Sepsis induces early alterations in innate immunity that impact mortality to secondary infection.</a> J Immunology. 186, 195-202 (2011).</li><li>Lange, M., 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=A+murine+model+of+sepsis+following+smoke+inhalation+injury.">A murine model of sepsis following smoke inhalation injury.</a> Biochem Biophys Res Commun. 391 (3), 1555-1560 (2010).</li><li>Kobayashi, Y. <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+chemokines+in+neutrophil+biology.">The role of chemokines in neutrophil biology.</a> Front Biosci. 13, 2400-2407 (2008).</li><li>Matute-Bello, G., 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=Animal+models+of+acute+lung+injury.">Animal models of acute lung injury.</a> Am J Physiol Lung Cell Mol Physiol. 295, L379-L399 (2008).</li><li>Sadikot, R. 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=Targeted+immunomodulation+of+the+nf-kappab+pathway+in+airway+epithelium+impacts+host+defense+against+pseudomonas+aeruginosa.">Targeted immunomodulation of the nf-kappab pathway in airway epithelium impacts host defense against pseudomonas aeruginosa.</a> J Immunol. 176, 4923-4930 (2006).</li><li>Pinto, I. L., 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=Development+of+an+experimental+model+of+neutrophilic+pulmonary+response+induction+in+mice.">Development of an experimental model of neutrophilic pulmonary response induction in mice.</a> J Pneumologia. 29, 213-214 (2003).</li></ol>

The authors have nothing to disclose.

Il mouse polmone modello di lesioni Pseudomonas che descriviamo qui imita l&#39;intero processo di infiammazione, danno polmonare, la riparazione e la risoluzione che si verificano a seguito di lesione polmonare acuta o polmonite. Ha vantaggi unici a confronto con diversi altri modelli di pregiudizio, in quanto è clinicamente rilevante e relativamente sicuro e facile da maneggiare. La fase critica nella procedura è che l&#39;iniezione della soluzione di batteri deve essere molto lenta. Se ...

I polmoni sono esposti agli agenti patogeni ambientali e sono suscettibili di infiammazione e lesioni 1-3. In condizioni patologiche come la polmonite o sindrome da sofferenza respiratoria dell&#39;adulto (ARDS), agenti patogeni e fattori infiammatori rilasciati dai leucociti inducono lesioni e la morte delle cellule alveolari 1-3. E &#39;importante sviluppare modelli animali di danno polmonare acuto per facilitare lo studio della patologia del pregiudizio, nonché il meccanismo di riparazione. Attualmente, la maggior parte delle persone usano iperossia e bleomicina topo indotto modelli danno polmonare 4. Tuttavia, i meccanismi di iperossia causato lesioni non sono gli stessi come maggior parte delle lesioni polmonari comuni che si verificano durante polmonite o ARDS 5. Bleomicina indotta lesione acuta è rara in un contesto clinico 4. Qui riportiamo un polmone modello di lesione del mouse usando iniezione intra-tracheale di P. aeruginosa 6,7. Questo modello è clinicamente rilevante, e imita il processes che accadono dopo la polmonite 8. Come un opportunista, agente patogeno nosocomiale di individui immunocompromessi, P. aeruginosa infetta in genere il tratto polmonare, delle vie urinarie, ustioni, ferite, e causa anche altre infezioni del sangue 6. Il batterio rilascia virulenza fattore esotossina A, si moltiplicano e si scatenano risposte immunitarie 6. Somministrazione intra-trachael di P. aeruginosa riflette la situazione di esposizione umana ai batteri che causano la polmonite e la patologia è probabile che sia diverso dal virus H1N1 dell&#39;influenza polmonare indotta modello di lesione recentemente riportato 9. Dal momento che P. aeruginosa è un patogeno opportunista, è relativamente sicuro da maneggiare rispetto ad alcuni dei patogeni più virulenti. Qui abbiamo usato iniezione intra-tracheale per amministrare i batteri, perché abbiamo osservato che questo metodo ha introdotto più batteri nella regione distale alveoli del polmone rispetto aalcune altre procedure come l&#39;utilizzo di un catetere attraverso la bocca. Rispetto ad altri modelli di danno polmonare acuto, il P. aeruginosa modello qui descritto è adatto per studiare danno polmonare indotta da batteri e infiammazione eccessiva. A differenza di altri modelli animali che utilizzano P. aeruginosa per indurre la sepsi 10,11, qui si usa l&#39;iniezione intra-tracheale di questi batteri di indurre localizzata danno polmonare acuto.

<table border="0" cellpadding="0" cellspacing="0" width="650">
	<tbody>
		<tr height="26">
			<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>
			<td style="width:145px;"></td>
			<td style="width:145px;"></td>
			<td style="width:145px;">pharmaceutical grade</td>
		</tr>
		<tr height="26">
			<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>
		</tr>
		<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>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:215px;">scissors</td>
			<td style="width:145px;">Fine Science tools</td>
			<td style="width:145px;"></td>
			<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>
			<td style="width:145px;"></td>
			<td style="width:145px;"></td>
		</tr>
		<tr height="26">
			<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>
		</tr>
		<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>
			<td></td>
			<td>Clidox</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;">sheep blood agar plates&#160;</td>
			<td>Medex supply</td>
			<td>HL-1160</td>
			<td></td>
		</tr>
	</tbody>
</table>

pseudomonas aeruginosa induced lung injury model

Per studiare danno polmonare acuto umana e la polmonite, è importante sviluppare modelli animali per simulare varie caratteristiche patologiche di questa malattia. Qui abbiamo sviluppato un modello di topo polmone lesioni da iniezione intra-tracheale di batteri Pseudomonas aeruginosa (P. aeruginosa o PA). Utilizzando questo modello, siamo stati in grado di mostrare l&#39;infiammazione polmonare in fase precoce di lesioni. Inoltre, alveolare leakiness barriera epiteliale è stato osservato analizzando lavaggio broncoalveolare (BAL); e la morte delle cellule alveolari è stato osservato da Tunel test utilizzando il tessuto ottenuto da polmoni feriti. In una fase successiva dopo un trauma, abbiamo osservato proliferazione cellulare richiesto per il processo di riparazione. L&#39;infortunio è stato risolto 7 giorni dalla apertura di P. aeruginosa iniezione. Questo modello riproduce il corso sequenziale di infiammazione polmonare, lesioni e di riparazione durante la polmonite. Questo modello animale clinicamente rilevante è adatto per studiare la patologia, il meccanismo di riparazione, fopo danno polmonare acuto, e può anche essere usato per testare potenziali agenti terapeutici per questa malattia.

Partendo 24-72 ore dopo P. iniezione aeruginosa, aumentata cellularità è stata osservata in sezioni polmonari (Figura 1A-D). Il polmone ha iniziato a recuperare da infortuni 96 ore dopo (Figura 1E). A 7 giorni dopo il P. aeruginosa, normale morfologia alveoli è stato in gran parte restaurato (Figura 1F). Tunnel di colorazione sezioni grazie polmonari preparati in 24 ore di post P. aeruginosa ha mostrato la morte cellulare nelle cel...

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 Induced Lung Injury Modello

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 Views.  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.

Co-coltura Modelli di Pseudomonas aeruginosa Biofilm Cresciuto in diretta cellule delle vie aeree umane

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

Ricerca

Immunologia e infezioni

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 e biofilm Saccharomyces cerevisiae in celle di flusso

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.

Isolamento del RNA Pseudomonas aeruginosa Colonizzare la Murine tratto gastrointestinale

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 di un terreno dell&#39;espettorato artificiale per testare l&#39;efficacia degli antibiotici contro<em&gt; Pseudomonas aeruginosa</em&gt; In condizioni più rilevanti al polmone Fibrosi Cistica

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.

Long Term cronica<em&gt; Pseudomonas aeruginosa</em&gt; Infezione delle vie aeree nei topi

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.

Replica di ordinato, Nonredundant biblioteca del ceppo di Pseudomonas aeruginosa PA14 trasposone inserimento mutanti

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.

Metodi per rilevare amiloidi seguente infezione di polmonare endoteliali cellule citotossiche da Pseudomonas aeruginosa

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

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.

Cultura della piccola colonia Variante di Pseudomonas aeruginosa e Quantitazione del suo 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 modello di inoculazione ritardata dell'infezione cronica di Pseudomonas aeruginosa Wound

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

Studying Effects of Cigarette Smoke on Pseudomonas Infection in Lung Epithelial Cells

Cigarette smoking is the major etiological cause for lung emphysema and chronic obstructive pulmonary disease (COPD). Cigarette smoking also promotes susceptibility to bacterial infections in the respiratory system. However, the effects of cigarette smoking on bacterial infections in human lung epithelial cells have yet to be thoroughly studied. Described here is a detailed protocol for the preparation of cigarette smoking extracts (CSE), treatment of human lung epithelial cells with CSE, and bacterial infection and infection determination. CSE was prepared with a conventional method. Lung epithelial cells were treated with 4% CSE for 3 h. CSE-treated cells were, then, infected with Pseudomonas at a multiplicity of infection (MOI) of 10. Bacterial loads of the cells were determined by three different methods. The results showed that CSE increased Pseudomonas load in lung epithelial cells. This protocol, therefore, provides a simple and reproducible approach to study the effect of cigarette smoke on bacterial infections in lung epithelial cells.

Studying Effects of Cigarette Smoke on Pseudomonas Infection in Lung Epithelial Cells

Described here is a protocol to study how cigarette smoke extract affects bacterial colonization in lung epithelial cells.

Studiare gli effetti del fumo di sigaretta sull'infezione da pseudomona nelle cellule epiteliali polmonari

Cigarette smoking is the major etiological cause for lung emphysema and chronic obstructive pulmonary disease (COPD). Cigarette smoking also promotes ...