Riconosciamo Chi-Chung Chen dal dipartimento di ricerca medica, Chi Mei Medical Center (Tainan, Taiwan) per l'aiuto nel topo di infezione e il supporto dal centro laboratorio animale della National Cheng Kung University. Questo lavoro è sostenuto dal Ministro della scienza e tecnologia (MOST) concede (più 104-2321-B-006-019, 105-2321-B-006-011,-005 and106-2321-B-006) a CC.

Attenzione: EHEC O157: H7 è un livello di biosicurezza 2 (BSL-2) agente patogeno secondo i Centers for Disease Control and Prevention (CDC) istruzioni di sicurezza biologica (https://www.cdc.gov/). Di conseguenza, tutte le procedure sperimentali che coinvolgono EHEC devono essere effettuate in una struttura di BSL-2. Indossare guanti e camici da laboratorio quando si effettua l'esperimento. Lavorare in una certificato di biosicurezza (BSC). Disinfettare il banco sperimentale prima e dopo la procedura sperimentale con etanolo al 70%. Tutti gli strumenti o attrezzature che EHEC contatto (o potenzialmente contatto) deve essere disinfettata con etanolo al 70% o candeggina. Rifiuti contaminati (o potenzialmente contaminati) dovrebbero essere accuratamente sigillati e sterilizzati in autoclave. Indossare una maschera, occhiali protettivi, guanti doppio o una tuta, se necessario. I topi femminili C57BL/6 di 6-settimana-vecchio sono stati acquistati e mantenuti presso il laboratorio animale Center del National Cheng Kung University (NCKU). Esperimenti sugli animali sono stati approvati dal istituzionale Animal Care e uso Comitato di NCKU (numero di omologazione 104-039).
1. generazione di batteri EHEC Bioluciferase-etichettato
<ol><li>Mix 50 ng dell'acido deossiribonucleico (DNA), 1 μL ogni 10 μm avanti e indietro primer, 2 μL 2,5 mM deossinucleotidi (dNTP), 2 μL 10 x buffer, 0,2 μL DNA polimerasi e acqua bidistillata sterile (ddH2O) ad un volume finale di 20 μL per amplificare il Cassetta anti-kanamicina, nptII gene24. Il modello di DNA è da pBSL18024, che è stato acquistato da progetto nazionale di BioResource (NBRP). Le condizioni PCR sono elencate nella tabella 1 e sequenza del primer è disponibile nella tabella 2.</li>
	<li>Legare i prodotti di PCR in un vettore di clonazione commerciale seguendo il kit protocollo (Vedi Tabella materiali).</li>
	<li>Asportare il frammento del gene nptII dal vettore di clonazione da NsiI e SmaI e clonare in pBBR1MCS4, che viene digerito dal NsiI e ScaI da pAKlux29 per creare il plasmide resistente kanamicina, pWF27813.</li>
	<li>Asportare l'operone luxCDABE , dalla luciferasi esprimendo plasmide9, pAKlux2, di SpeI-HF e ScaI e clone SpeI-HF e SmaI digerito pWF278 per generare kanamicina resistente e luciferasi esprimendo plasmide, pWF27913. Nota: Per le estrazioni di plasmide e le purificazioni di frammento asportato, utilizzare l'estrazione commerciale plasmide e il kit di estrazione del gel, rispettivamente. Per digestione degli enzimi, mescolare 100 ng DNA, 1 μL 10 x buffer, 1 μL di ogni selezionato degli enzimi di limitazione e sterile ddH2O ad un volume totale di 10 μL e incubare a 37 ° C per 2,5-3 ore.</li>
	<li>Trasformare il plasmide pWF279 in cellule competenti di Escherichia coli O157: H7 EDL933 mediante elettroporazione con 2.500 V per 4 ms.</li>
	<li>Incubare le cellule di batteri trasformati in 1 mL di terreno di Luria-Bertani (LB) a 37 ° C per 1 h.</li>
	<li>Piastra i batteri su una piastra di agar LB completati con 50 µ g/mL di kanamicina a 37 ° C per 16-18 h.</li>
	<li>Controllare il segnale bioluminescente della piastra da uno in vivo imaging macchina il giorno successivo. Scegli una singola Colonia dalla piastra e cultura esso in 3 mL di LB completati con 50 kanamicina µ g/mL a 37 ° C per 16-18 h.</li>
	<li>Preparare il supporto di stock batterico diluendo 100% glicerolo sterile ddH2O per rendere la soluzione di glicerolo di 30%.</li>
	<li>La kanamicina resistente al gelo e. coli O157: H7 EDL933 batteri che harboring il plasmide luciferasi come azione batterica in un tappo a vite cryovial come un rapporto di 1:1 di soluzione di glicerolo cultura e 30% di batteri a-80 ° C. La concentrazione finale del glicerolo è del 15%.</li>
</ol>2. preparazione di batteri EHEC bioluminescenti per inoculazione orale
Nota: Il diagramma di flusso di timeline delle procedure sperimentali per la preparazione di EHEC e sonda gastrica orale del mouse è presentato nella Figura 1 per aiutare nella preparazione sperimentale.
<ol><li>Striscia e. coli O157: H7 EDL933 batteri che harboring plasmide luciferasi su una piastra di agar LB con 50 kanamicina µ g/mL a magazzino di-80 ° C. Crescere i batteri per 16-18 h a 37 ° C.</li>
	<li>Scegliere una singola Colonia dalla piastra durante la notte e la cultura in 3 mL LB medium con 50 kanamicina µ g/mL per 16-18 h in un incubatore a 37 ° C a 220 giri/min.</li>
	<li>Sottocultura i batteri (diluizione 1: 100) in kanamicina (50 µ g/mL) contenenti brodo LB per 2.5-3 h in un incubatore a 37 ° C a 200 giri/min. (Per esempio, aggiungere 2 mL coltivato durante la notte i batteri per mL 200 LB supplementato con kanamicina (50 µ g/mL)).</li>
	<li>Incubare i batteri per 2.5-3 h e misurare il valore di densità ottica a 600 nm (OD600) fino a quando il valore è compreso tra 0,9 a 1. Il numero di cellule batteriche è una densità di8 di circa 10 con unità formanti colonie (CFU) / mL.</li>
	<li>Centrifugare i batteri ri-colti a 8.000 x g per 30 min, 4 ° C.</li>
	<li>Scartare il supernatante senza agitare il pellet di batteri e lavare la pallina con 100 mL 0,9% normale soluzione salina sterile di movimentazione delicata.</li>
	<li>Ripetere i passaggi da 2.5 e 2.6 una volta.</li>
	<li>Dopo il lavaggio, centrifugare la coltura batterica a 8.000 x g per 30 min, 4 ° C e scartare il surnatante delicatamente.</li>
	<li>Condensa il pellet a 100 volte con soluzione salina sterile 0,9%. Per esempio, se sono centrifugati batteri 200 mL, aggiungere 2 mL di normale soluzione salina per sospendere il pellet.</li>
	<li>Confermare i batteri CFU (dovrebbe essere circa 109 CFU/100 μL dopo condensazione in salino normale) i batteri concentrati attraverso una diluizione seriale 10 volte25di placcatura.</li>
</ol>3. Mouse Gavage orale di EHEC
<ol><li>Trattare 6-settimana-vecchi topi C57BL/6 femminili con acqua di streptomicina (5 g/L) per 24 h.</li>
	<li>Dopo 24 h, passare alla normale acqua potabile per un altro 24 h prima sonda gastrica. Dopo il trattamento con acqua normale per 24 h, i topi sono pronti per sonda gastrica orale di EHEC.</li>
	<li>Riempire la siringa con 100 batteri EHEC di μL tirando indietro lo stantuffo. Assicurarsi che non siano bolle d'aria nella siringa. Rimuovere le bolle schioccando la siringa con le dita.</li>
	<li>Sollevare delicatamente l'animale e posizionarlo sulla parte superiore gabbia con cura.</li>
	<li>Afferrare il mouse per la coda con attenzione, e l'animale verrà presa nella parte superiore della gabbia e tentare di allontanare.</li>
	<li>Frenare dolcemente il mouse afferrando la pelle flaccida del collo e sul retro l'animale con pollice e indice per impedire che la testa del mouse in movimento.</li>
	<li>Tenere premuto il mouse in posizione verticale per inserire l'ago sonda gastrica e garantire che la testa del mouse è immobilizzato e verticale.</li>
	<li>Inserire l'ago sonda gastrica in bocca del mouse seguendo il tetto della bocca e spostare verso il basso nell'esofago e verso lo stomaco.</li>
	<li>Quando l'ago inserito è metà o due terzi lunghezza nel topo, iniettare 100 batteri EHEC μL, che contengono circa 10 celle di9 CFU.</li>
</ol>4. visualizzazione
<ol><li>Dopo l'alimentazione mediante sonda gastrica orale, rilevare i segnali bioluminescenti nei giorni 1 e 2.</li>
	<li>Prima di esaminare i segnali bioluminescenti di animali, li anestetizzare inserendole in una camera di 2,5% isoflurane con 1,5 L/min di ossigeno.</li>
	<li>Attendere 2-5 min fino a quando tutti i topi diventano inconscio e si fermano. Gli animali sono pronti per la rilevazione in vivo della bioluminescenza.</li>
	<li>Rilevare e immagine bioluminescenti segnali di animali da uno in vivo imaging system. Vedi sezione 5 "Acquisizione dati" per il funzionamento del software. Durante il processo di imaging, tutti gli animali sono sotto una fornitura continua di 2,5% isoflurane con 1,5 L/min di ossigeno.<ol>
<li>Fare clic su file > dal vivo e manualmente si concentrerà sul mouse.</li>
		<li>Selezionare l'intensità di laser e tempo di esposizione.</li>
		<li>Fare clic su acquisire > catturare.</li>
	</ol>
</li>
	<li>Per l'ex vivo imaging, eutanasia i topi di dislocazione cervicale e rimuovere l'intero intestino dei topi infettati. Posizionare l'intestino in una capsula di Petri e immagine a 9 cm dal in vivo imaging sistema. L'impostazione è la stessa come l'in vivo imaging tranne il campo di vista è impostato come A/B. Per dettagli, vedere sezione 5 "Acquisizione dati". Nota: Il metodo per dislocazione cervicale: frenare i topi sulla parte superiore gabbia afferrando la coda con una mano in modo che gli animali afferrare la gabbia. Posizionare un pennarello o il pollice e l'indice di altra mano contro la parte posteriore del collo alla base del cranio. Spingere in avanti con la mano o un oggetto mentre tratteneva la testa e tirare all'indietro con la mano che tiene la coda rapidamente. Controllare molto attentamente per confermare l'arresto respiratorio e nessun battito cardiaco.</li>
</ol>5. acquisizione dati
Nota: Il software utilizzato per l'acquisizione dati è elencato nella Tabella materiali.
<ol><li>Per acquisizione di immagini, aprire il pannello di controllo di acquisizione del software (Figura 2).</li>
	<li>Selezionare "Luminescente", "fotografare" e "Overlay".</li>
	<li>Impostare il tempo di esposizione come "Auto". Impostare Binning come "Medio".</li>
	<li>Impostare ƒ/stop come 1 per luminescenti e 8 per fotografia. Ƒ/stop controlli la quantità di luce ricevuta dal sensore CCD.</li>
	<li>Impostare il campo visivo basato sul campo delle immagini che sono di interesse per l'acquisizione. Opzione "D" può montare cinque 6-settimana-vecchi topi e loro immagine tutto in un momento. "C" potete immagine tre 6-settimana-vecchi topi in un campo.</li>
	<li>Una volta che i topi/campioni sono pronti per l'imaging, fare clic su "Acquire" per acquisizione di immagini.</li>
	<li>Aprire i dati di immagine che è stati acquistati.</li>
	<li>Aprire il pannello tavolozza degli strumenti (Figura 3).</li>
	<li>Selezionare strumenti di ROI. Si consiglia il cerchio (quello più a sinistra) alla gamma della zona bioluminescente sulle immagini (Figura 4).</li>
	<li>Fare clic su "Misura ROIs" (icona di matita) per misurare l'intensità bioluminescente superficie (Figura 3). Il pannello di ROI misurazioni e i valori di quantificazione appaiono (Figura 5).</li>
	<li>Utilizzare la misurazione configurare nell'angolo sinistro del pannello misure ROI per selezionare i valori/informazioni necessarie (Figura 6), in caso contrario fare clic su "Esporta" per esportare questa tabella di dati e salvare come file CSV (Figura 5).</li>
	<li>Utilizzare i valori della colonna "Flusso totale (p/s)" come la quantificazione bioluminescenti intensità nel file CSV.</li>
</ol>

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Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+green+fluorescence.">Improved green fluorescence.</a> Nature. 373 (6516), 663-664 (1995).</li><li>Weissleder, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+clearer+vision+for+in+vivo+imaging.">A clearer vision for in vivo imaging.</a> Nat Biotechnol. 19 (4), 316-317 (2001).</li><li>Frangioni, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+near-infrared+fluorescence+imaging.">In vivo near-infrared fluorescence imaging.</a> Current Opinion in Chemical Biology. 7 (5), 626-634 (2003).</li><li>Collins, J. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Citrobacter+rodentium:+infection,+inflammation+and+the+microbiota.">Citrobacter rodentium: infection, inflammation and the microbiota.</a> Nat Rev Microbiol. 12 (9), 612-623 (2014).</li><li>Mallick, E. 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+novel+murine+infection+model+for+Shiga+toxin-producing+Escherichia+coli.">A novel murine infection model for Shiga toxin-producing Escherichia coli.</a> J Clin Invest. 122 (11), 4012-4024 (2012).</li><li>Petty, N. 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=The+Citrobacter+rodentium+genome+sequence+reveals+convergent+evolution+with+human+pathogenic+Escherichia+coli.">The Citrobacter rodentium genome sequence reveals convergent evolution with human pathogenic Escherichia coli.</a> J Bacteriol. 192 (2), 525-538 (2010).</li><li>Kovach, M. E., Elzer, P. H., Hill, D. S., Robertson , G. T., Farris, M. A., Roop, R. M., Peterson, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Four+new+derivatives+of+the+broad-host-range+cloning+vector+pBBR1MCS,+carrying+different+antibiotic-resistance+cassettes.">Four new derivatives of the broad-host-range cloning vector pBBR1MCS, carrying different antibiotic-resistance cassettes.</a> Gene. 166 (1), 175-176 (1995).</li><li>Galen, J. E., Nair, J., Wang , J. Y., Wasserman, S. S., Tanner, M. K., Sztein , M. B., Levine, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+Plasmid+Maintenance+in+the+Attenuated+Live+Vector+Vaccine+Strain+Salmonella+typhiCVD+908-htrA.">Optimization of Plasmid Maintenance in the Attenuated Live Vector Vaccine Strain Salmonella typhiCVD 908-htrA.</a> Infect Immun. 67 (12), 6424-6433 (1999).</li><li>Francis, K. P., 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=Visualizing+pneumococcal+infections+in+the+lungs+of+live+mice+using+bioluminescent+Streptococcus+pneumoniae+transformed+with+a+novel+gram-positive+lux+transposon.">Visualizing pneumococcal infections in the lungs of live mice using bioluminescent Streptococcus pneumoniae transformed with a novel gram-positive lux transposon.</a> Infect Immun. 69 (5), 3350-3358 (2001).</li><li>Goldwater, P. N., Bettelheim, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+of+enterohemorrhagic+Escherichia+coli+(EHEC)+infection+and+hemolytic+uremic+syndrome+(HUS).">Treatment of enterohemorrhagic Escherichia coli (EHEC) infection and hemolytic uremic syndrome (HUS).</a> BMC Med. 10, (2012).</li></ol>

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È stato segnalato che EHEC trasformati con il plasmide luciferasi è stato utilizzato per esaminare la localizzazione nel host o espressione genica in vivo8,11,12. Il modello murino dimostrato qui è stato segnalato anche per rilevare i tempi di EHEC colonizzato e localizzazione in host murino8. Tuttavia, forniamo il protocollo di dettaglio di come amministrare l'inoculazione di EHEC ai topi int...

EHEC O157: H7 è un patogeno che causa diarrea1, HS2, HUS3e anche insufficienza renale4 attraverso cibo o acqua contaminato. EHEC è un patogeno enterobacterium e colonizza il tratto gastrointestinale di esseri umani1. Quando EHEC prima aderire all'epitelio intestinale host, iniettano i fattori di colonizzazione nelle cellule ospiti attraverso il sistema di secrezione di III tipo (T3SS) che funziona come una siringa molecolare che induce un fissaggio e cancellando (A/E) lesione successivamente per imporre adesione (colonizzazione)5. Questi geni coinvolti nella formazione della lesione A/E codificati per il locus dell'enterocita (LEE) il effacement patogenicità isola5.
Bioluminescenza è una reazione chimica produzione di luce, in cui luciferasi catalizza la luciferina di substrato per generare luce visibile6. Questo processo enzimatico richiede spesso la presenza di ossigeno o l'adenosina trifosfato (ATP)6. Bioluminescenza imaging (BLI) permette ai ricercatori la visualizzazione e la quantizzazione delle interazioni ospite-patogeno in animali vivi7. BLI possono caratterizzare il ciclo di infezione batterica in animali vivi seguendo i batteri bioluminescenti come migrare e invadere i tessuti differenti7; Questo rivela una progressione dinamica dell'infezione. Inoltre, la carica batterica negli animali è relativo al segnale bioluminescenti8; così, è un comodo indicatore per stimare le condizioni patologiche degli animali da esperimento in modo semplice e diretto.
Il plasmide usato qui contenute l'operone luciferasi, luxCDABE, che è il batterio Photorhabdus luminescens che codifica la propria luciferasi substrato7,9. Trasformando questo plasmide esprimendo la luciferasi in batteri, i processi di colonizzazione e l'infezione possono essere monitorati osservando questi batteri bioluminescenti animali vivi. Nel complesso, BLI e bioluminescenza-identificati batteri permettono ai ricercatori di monitorare i numeri batterici e la posizione, la vitalità batterica con antibiotici/terapia trattamento ed espressione genica batterica infezione/colonizzazione6, 7. sono stati segnalati numerosi batteri patogeni che esprimono l'operone luxCDABE per esaminare la loro espressione di ciclo e/o gene di infezione nell'infezione. Questi batteri, tra cui uropathogenic Escherichia coli10, EHEC8,11,12,13, enteropatogeni e. coli (EPEC)8, Citrobacter Rodentium14,15, Salmonella typhimurium16, Listeria monocytogenes17, Yersinia enterocolitica18,19, e Vibrio cholerae20, sono stati documentati.
Parecchi modelli sperimentali sono stati sviluppati per facilitare lo studio di EHEC colonizzazione in vitro e in vivo21,22,23. Tuttavia, c'è una mancanza di adeguati modelli animali per studiare l'EHEC colonizzazione in vivoe quindi una conseguente scarsità di dettagli. Per facilitare lo studio di EHEC colonizzazione meccanismo in vivo, è prezioso per costruire modelli animali per osservare e quantificare la colonizzazione di EHEC animali vivi in un metodo non-invasivo.
Questo manoscritto descrive un modello di colonizzazione del mouse-EHEC che utilizza un sistema di espressione bioluminescente per monitorare la colonizzazione di EHEC nel tempo in soggiorno ospiti. Topi intragastrically vengono inoculati con bioluminescenza-labeled EHEC e viene rilevato il segnale bioluminescente in topi con un non-invasiva in vivo imaging sistema13. I topi infettati con bioluminescenza-labeled EHEC hanno mostrato significativi segnali bioluminescenti in loro intestino dopo 2 giorni dopo l'infezione, che ha suggerito che tali batteri colonizzarono nell'intestino ospite dopo 2 giorni dopo l'infezione. Ex vivo immagine dati hanno mostrato che questa colonizzazione è specificamente nell'intestino cieco e del colon dei topi. Utilizzando questo modello di mouse-EHEC, la colonizzazione di EHEC bioluminescente può essere rilevata nell'ospite vivente da uno in vivo imaging system, per studiare i meccanismi dettagliati della colonizzazione di batteri enterici, che possono promuovere ulteriore comprensione in Cambiamenti fisiologici e patologici indotti da EHEC.

<table><tbody><tr><td>Shaker incubator</td><td>YIH DER</td><td>LM-570R</td><td>bacteria incubation&amp;nbsp;</td></tr><tr><td>Orbital shaking incubator</td><td>FIRSTEK</td><td>S300</td><td>bacteria incubation&amp;nbsp;</td></tr><tr><td>pBSL180</td><td></td><td></td><td>source of nptII gene</td></tr><tr><td>pAKlux2</td><td></td><td></td><td>source of luxCDABE operon</td></tr><tr><td>T&amp;amp;A Cloning Kit</td><td>Yeastern Biotech</td><td>FYC001-20P</td><td>use for TA cloning&amp;nbsp;</td></tr><tr><td>&lt;em&gt;Nsi&lt;/em&gt; I</td><td>NEB</td><td>R0127S</td><td>use for plasmid cloning&amp;nbsp;</td></tr><tr><td>&lt;em&gt;Sca&lt;/em&gt; I</td><td>NEB</td><td>R0122S</td><td>use for plasmid cloning&amp;nbsp;</td></tr><tr><td>&lt;em&gt;Spe&lt;/em&gt; I-HF</td><td>NEB</td><td>R0133S</td><td>use for plasmid cloning&amp;nbsp;</td></tr><tr><td>&lt;em&gt;Sma&lt;/em&gt; I&amp;nbsp;</td><td>NEB</td><td>R0141S</td><td>use for plasmid cloning&amp;nbsp;</td></tr><tr><td>T4 ligase</td><td>NEB</td><td>M0202S</td><td>use for plasmid cloning&amp;nbsp;</td></tr><tr><td>Ex Taq</td><td>TaKaRa</td><td>RR001A</td><td>use for PCR amplification</td></tr><tr><td>10X Ex Taq Buffer</td><td>TaKaRa</td><td>RR001A</td><td>use for PCR amplification</td></tr><tr><td>dNTP Mixture&amp;nbsp;</td><td>TaKaRa</td><td>RR001A</td><td>use for PCR amplification</td></tr><tr><td>PCR machine</td><td>applied Biosystem&amp;nbsp;</td><td>2720 thermal cycler&amp;nbsp;</td><td>&amp;nbsp;for PCR amplification</td></tr><tr><td>Glycerol</td><td>SIGMA</td><td>G5516-1L</td><td>use for bacteria stocking solution</td></tr><tr><td>NaCl</td><td>Sigma</td><td>31434-5KG-R</td><td>chemical for making LB medium, 10 g/L</td></tr><tr><td>Tryptone</td><td>CONDA pronadisa</td><td>Cat 1612.00</td><td>chemical for making LB medium, 10 g/L</td></tr><tr><td>Yeast Extract powder</td><td>Affymetrix</td><td>23547-1 KG</td><td>chemical for making LB medium, 5 g/L</td></tr><tr><td>Agar</td><td>CONDA pronadisa</td><td>Cat 1802.00</td><td>chemical for making LB agar</td></tr><tr><td>kanamycin&amp;nbsp;</td><td>Sigma</td><td>K4000-5G</td><td>antibiotics, use for seleciton</td></tr><tr><td>streptomycin&amp;nbsp;</td><td>Sigma</td><td>S6501-100G</td><td>antibiotics, eliminate the microbiota in mice</td></tr><tr><td>EDL933 competent cell</td><td>Homemade</td><td></td><td>method is on supplemental document&amp;nbsp;</td></tr><tr><td>Electroporator</td><td>MicroPulser</td><td></td><td>for electroporation</td></tr><tr><td>Electroporation Cuvettes</td><td>Gene Pulser/MicroPulser</td><td>1652086</td><td>for electroporation</td></tr><tr><td>High-speed centrifuge</td><td>Beckman Coulter</td><td>Avanti, J-26S XP</td><td>use for centrifuging bacteria&amp;nbsp;</td></tr><tr><td>Fixed-Angle Rotor</td><td>Beckman Coulter</td><td>JA25.5</td><td>use for centrifuging bacteria&amp;nbsp;</td></tr><tr><td>Fixed-Angle Rotor</td><td>Beckman Coulter</td><td>JLA10.5</td><td>use for centrifuging bacteria&amp;nbsp;</td></tr><tr><td>centrifuge bottles</td><td>Beckman Coulter</td><td>REF357003</td><td>use for centrifuging bacteria&amp;nbsp;</td></tr><tr><td>centrifuge bottles</td><td>Thermo Fisher scientific</td><td>3141-0500</td><td>use for centrifuging bacteria&amp;nbsp;</td></tr><tr><td>eppendorf biophotometer plus&amp;nbsp;</td><td>eppendorf</td><td>AG 22331 hamburg</td><td>for measuring the OD600 value of bacteria</td></tr><tr><td>C57BL/6 mice&amp;nbsp;</td><td>Laboratory Animal Center of NCKU</td><td></td><td></td></tr><tr><td>lab coat, gloves</td><td></td><td></td><td>for personnel protection&amp;nbsp;</td></tr><tr><td>isoflurane&amp;nbsp;</td><td>Panion &amp;amp; BF Biotech Inc.</td><td>G-8669</td><td>for mice anesthesia, pharmaceutical grade</td></tr><tr><td>1ml syringe&amp;nbsp;</td><td></td><td></td><td>use for oral gavage of mice</td></tr><tr><td>Reusable 22 G ball-tipped feeding needle</td><td></td><td>&amp;phi;0.9 mm X L 50 mm</td><td>use for oral gavage of mice</td></tr><tr><td>surgical&amp;nbsp; scissors&amp;nbsp;</td><td></td><td></td><td>use for mice experiment</td></tr><tr><td>Xenogen IVIS 200 imaging system</td><td>Perkin Elmer</td><td>IVIS spectrum</td><td>use for bioluminescent image capture&amp;nbsp;</td></tr><tr><td>Living Image Software</td><td>Perkin Elmer</td><td>version 4.1</td><td>use for quantifying the image data</td></tr></tbody></table>

detection of enterohemorrhagic escherichia coli colonization in murine host by non-invasive in vivo bioluminescence system

Enteroemorragica e. coli (enteroemorragico EHEC) O157: H7, che è un agente patogeno portato dagli alimenti che causesdiarrhea, colite emorragica (HS), e la sindrome uremica emolitica (HUS), colonizzare il tratto intestinale degli esseri umani. Per studiare il meccanismo dettagliato della EHEC colonizzazione in vivo, è essenziale disporre di modelli animali per monitorare e quantificare la colonizzazione di EHEC. Dimostriamo qui un modello di colonizzazione del mouse-EHEC trasformando il plasmide di espressione bioluminescente per EHEC per monitorare e quantificare la colonizzazione di EHEC in soggiorno ospiti. Animali inoculati con bioluminescenza-labeled EHEC mostrano segnali bioluminescenti intensi in topi tramite rilevazione con un non-invasiva in vivo imaging sistema. Dopo 1 e 2 giorni dopo l'infezione, bioluminescenti segnali potrebbero essere ancora presente in animali infettati, che suggerisce che EHEC colonizzare in padroni di casa per almeno 2 giorni. Inoltre dimostriamo che questi EHEC bioluminescenti individuare all'intestino del mouse, specificamente nell'intestino cieco e del colon, da immagini di ex vivo . Questo modello di colonizzazione del mouse-EHEC può servire come strumento per far progredire la conoscenza corrente del meccanismo di colonizzazione di EHEC.

Abbiamo amministrato la bioluminescenza-labeled EHEC (~ 109 cellule batteriche) ai topi C57BL/6 femminili 6 - settimana-vecchi mediante sonda gastrica orale. Dopo la somministrazione orale di EHEC ai topi all'interno di 1h, gli animali sono stati esaminati per segnale bioluminescenti secondo il sistema di imaging in vivo come mostrato nella Figura 7. I risultati hanno mostrato un forte segnale bioluminescente in topi di sonda gastrica con ...

Watch this Scientific Journal Video about Detection of Enterohemorrhagic Escherichia Coli Colonization in Murine Host by Non-invasive In Vivo Bioluminescence System at JoVE.com

Detection of Enterohemorrhagic Escherichia Coli Colonization in Murine Host by Non-invasive In Vivo Bioluminescence System

Un protocollo dettagliato di un modello murino per enteroemorragica e. coli (enteroemorragico EHEC) colonizzazione tramite bioluminescenza-identificati batteri è presentato. La rilevazione di questi batteri bioluminescenti di un non-invasiva in vivo imaging sistema animali vivi può avanzare la nostra comprensione corrente della colonizzazione di EHEC.

Rilevamento della colonizzazione di Escherichia Coli enteroemorragica in murino Host di sistema Non invasivo In Vivo bioluminescenza

Enterohemorrhagic E. coli (EHEC) O157:H7, which is a foodborne pathogen that causesdiarrhea, hemorrhagic colitis (HS), and hemolytic uremic syndrome ...

detection-enterohemorrhagic-escherichia-coli-colonization-murine-host

Universidad de Cartagena UDEC

Research

JoVE Journal

Immunology and Infection

Detection of Enterohemorrhagic Escherichia Coli Colonization in Murine Host by Non-invasive In Vivo Bioluminescence System

9.4K Views.  National Cheng Kung University. Un protocollo dettagliato di un modello murino per enteroemorragica e. coli (enteroemorragico EHEC) colonizzazione tramite bioluminescenza-identificati batteri è presentato. La rilevazione di questi batteri bioluminescenti di un non-invasiva in vivo imaging sistema animali vivi può avanzare la nostra comprensione corrente della colonizzazione di EHEC.

Video: Detection of Enterohemorrhagic Escherichia Coli Colonization in Murine Host by Non-invasive In Vivo Bioluminescence System

Using Luciferase to Image Bacterial Infections in Mice

Imaging is a valuable technique that can be used to monitor biological processes. In particular, the presence of cancer cells, stem cells, specific immune cell types, viral pathogens, parasites and bacteria can be followed in real-time within living animals 1-2. Application of bioluminescence imaging to the study of pathogens has advantages as compared to conventional strategies for analysis of infections in animal models3-4. Infections can be visualized within individual animals over time, without requiring euthanasia to determine the location and quantity of the pathogen. Optical imaging allows comprehensive examination of all tissues and organs, rather than sampling of sites previously known to be infected. In addition, the accuracy of inoculation into specific tissues can be directly determined prior to carrying forward animals that were unsuccessfully inoculated throughout the entire experiment. Variability between animals can be controlled for, since imaging allows each animal to be followed individually. Imaging has the potential to greatly reduce animal numbers needed because of the ability to obtain data from numerous time points without having to sample tissues to determine pathogen load3-4.
This protocol describes methods to visualize infections in live animals using bioluminescence imaging for recombinant strains of bacteria expressing luciferase. The click beetle (CBRLuc) and firefly luciferases (FFluc) utilize luciferin as a substrate5-6. The light produced by both CBRluc and FFluc has a broad wavelength from 500 nm to 700 nm, making these luciferases excellent reporters for the optical imaging in living animal models7-9. This is primarily because wavelengths of light greater than 600 nm are required to avoid absorption by hemoglobin and, thus, travel through mammalian tissue efficiently. Luciferase is genetically introduced into the bacteria to produce light signal10. Mice are pulmonary inoculated with bioluminescent bacteria intratracheally to allow monitoring of infections in real time. After luciferin injection, images are acquired using the IVIS Imaging System. During imaging, mice are anesthetized with isoflurane using an XGI-8 Gas Anethesia System. Images can be analyzed to localize and quantify the signal source, which represents the bacterial infection site(s) and number, respectively. After imaging, CFU determination is carried out on homogenized tissue to confirm the presence of bacteria. Several doses of bacteria are used to correlate bacterial numbers with luminescence. Imaging can be applied to study of pathogenesis and evaluation of the efficacy of antibacterial compounds and vaccines.

Methods for bioluminescence imaging of bacterial infections in living animals are decribed. Pathogens are modified to express luciferase allowing optical whole body imaging of infections in live animals. Animal models can be infected with luciferase expressing pathogens and the resulting course of disease visualized in real-time by bioluminescence imaging.

Utilizzando luciferasi di infezioni batteriche immagine in topi

Imaging is a valuable technique that can be used to monitor biological processes.  In particular, the presence of cancer cells, stem cells, specific ...

Ricerca

Immunologia e infezioni

In vitro and in vivo Bioluminescence Reporter Gene Imaging of Human Embryonic Stem Cells

The discovery of human embryonic stem cells (hESCs) has dramatically increased the tools available to medical scientists interested in regenerative medicine. However, direct injection of hESCs, and cells differentiated from hESCs, into living organisms has thus far been hampered by significant cell death, teratoma formation, and host immune rejection. Understanding the in vivo hESC behavior after transplantation requires novel imaging techniques to longitudinally monitor hESC localization, proliferation, and viability. Molecular imaging has given investigators a high-throughput, inexpensive, and sensitive means for tracking in vivo cell proliferation over days, weeks, and even months. This advancement has significantly increased the understanding of the spatio-temporal kinetics of hESC engraftment, proliferation, and teratoma-formation in living subjects.

A major advance in molecular imaging has been the extension of noninvasive reporter gene assays from molecular and cellular biology into in vivo multi-modality imaging platforms. These reporter genes, under control of engineered promoters and enhancers that take advantage of the host cell s transcriptional machinery, are introduced into cells using a variety of vector and non-vector methods. Once in the cell, reporter genes can be transcribed either constitutively or only under specific biological or cellular conditions, depending on the type of promoter used. Transcription and translation of reporter genes into bioactive proteins is then detected with sensitive, noninvasive instrumentation (e.g., CCD cameras) using signal-generating probes such as D-luciferin.

To avoid the need for excitatory light to track stem cells in vivo as is required for fluorescence imaging, bioluminescence reporter gene imaging systems require only an exogenously administered probe to induce light emission. Firefly luciferase, derived from the firefly Photinus pyralis, encodes an enzyme that catalyzes D-luciferin to the optically active metabolite, oxyluciferin. Optical activity can then be monitored with an external CCD camera. Stably transduced cells that carry the reporter construct within their chromosomal DNA will pass the reporter construct DNA to daughter cells, allowing for longitudinal monitoring of hESC survival and proliferation in vivo. Furthermore, because expression of the reporter gene product is required for signal generation, only viable parent and daughter cells will create bioluminescence signal; apoptotic or dead cells will not. 

In this video, the specific materials and methods needed for tracking stem cell proliferation and teratoma formation with bioluminescence imaging will be described.

With the growing interest in stem cell therapies, molecular imaging techniques are ideal for monitoring stem cell behavior after transplantation. Luciferase reporter genes have enabled non-invasive, repetitive assessment of cell survival, location, and proliferation in vivo. This video will demonstrate how to track hESC proliferation in a living mouse.

In vitro e in Imaging bioluminescenza gene reporter in vivo di cellule staminali embrionali umane

The discovery of human embryonic stem cells (hESCs) has dramatically increased the tools available to medical scientists interested in regenerative ...

Biologia

In Situ Measurement and Correlation of Cell Density and Light Emission of Bioluminescent Bacteria

There is a considerable number of bacterial species capable of emitting light. All of them share the same gene cluster, namely the lux operon. Despite this similarity, these bacteria show extreme variations in characteristics like growth behavior, intensity of light emission or regulation of bioluminescence. The method presented here is a newly developed assay that combines recording of cell growth and bioluminescent light emission intensity over time utilizing a plate reader. The resulting growth and light emission characteristics can be linked to important features of the respective bacterial strain, such as quorum sensing regulation. The cultivation of a range of bioluminescent bacteria requires a specific medium (e.g., artificial sea water medium) and defined temperatures. The easy to handle, non-bioluminescent standard-research bacterium Escherichia coli (E. coli), on the other hand, can be cultivated inexpensively in high quantities in laboratory scale. Exploiting E. coli by introducing a plasmid containing the whole lux operon can simplify experimental conditions and additionally opens up many possibilities for future applications. The expression of all lux genes utilizing an E. coli expression strain was achieved by construction of an expression plasmid via Gibson cloning and insertion of four fragments containing seven lux genes and three rib genes of the lux-rib operon into a pET28a vector. E. coli based lux gene expression can be induced and controlled via Isopropyl-&#946;-D-thiogalactopyranosid (IPTG) addition resulting in bioluminescent E. coli cells. The advantages of this system are to avoid quorum sensing regulation restrictions and complex medium compositions along with non-standard growth conditions, such as defined temperatures. This system enables analysis of lux genes and their interplay, by the exclusion of the respective gene from the lux operon, or even addition of novel genes, exchanging the luxAB genes from one bacterial strain by another, or analyzing protein complexes, such as luxCDE.

In Situ Measurement and Correlation of Cell Density and Light Emission of Bioluminescent Bacteria

Bioluminescent bacteria regulate light production through a variety of mechanisms, such as quorum sensing. This novel method allows the in situ investigation of bioluminescence and the correlation of light emission to cell density. An artificial bioluminescent Escherichia coli system allows the characterization of lux operons, Lux proteins, and their interplay.

In Situ Misurazione e la correlazione di densità delle cellule ed emissione di luce di batteri bioluminescenti

There is a considerable number of bacterial species capable of emitting light. All of them share the same gene cluster, namely the lux operon. Despite ...

Biochimica

Bioluminescent Bacterial Imaging In Vivo

This video describes the use of whole body bioluminesce imaging (BLI) for the study of bacterial trafficking in live mice, with an emphasis on the use of bacteria in gene and cell therapy for cancer. Bacteria present an attractive class of vector for cancer therapy, possessing a natural ability to grow preferentially within tumors following systemic administration. Bacteria engineered to express the lux gene cassette permit BLI detection of the bacteria and concurrently tumor sites. The location and levels of bacteria within tumors over time can be readily examined, visualized in two or three dimensions. The method is applicable to a wide range of bacterial species and tumor xenograft types. This article describes the protocol for analysis of bioluminescent bacteria within subcutaneous tumor bearing mice. Visualization of commensal bacteria in the Gastrointestinal tract (GIT) by BLI is also described. This powerful, and cheap, real-time imaging strategy represents an ideal method for the study of bacteria in vivo in the context of cancer research, in particular gene therapy, and infectious disease. This video outlines the procedure for studying lux-tagged E. coli in live mice, demonstrating the spatial and temporal readout achievable utilizing BLI with the IVIS system.

Bioluminescent Bacterial Imaging In Vivo

This article describes the administration of lux-tagged bacteria to mice and subsequent in vivo analysis using IVIS bioluminescence imaging.

Bioluminescent Imaging batterica<em&gt; In Vivo</em

This video describes the use of whole body bioluminesce imaging (BLI) for the study of bacterial trafficking in live mice, with an emphasis on the use of ...

In Vivo Imaging Systems (IVIS) Detection of a Neuro-Invasive Encephalitic Virus

Modern advancements in imaging technology encourage further development and refinement in the way viral research is accomplished. Initially proposed by Russel and Burch in Hume's 3Rs (replacement, reduction, refinement), the utilization of animal models in scientific research is under constant pressure to identify new methodologies to reduce animal usage while improving scientific accuracy and speed. A major challenge to Hume's principals however, is how to ensure the studies are statistically accurate while reducing animal disease morbidity and overall numbers. Vaccine efficacy studies currently require a large number of animals in order to be considered statistically significant and often result in high morbidity and mortality endpoints for identification of immune protection. We utilized in vivo imaging systems (IVIS) in conjunction with a firefly bioluminescent enzyme to progressively track the invasion of the central nervous system (CNS) by an encephalitic virus in a murine model. Typically, the disease progresses relatively slowly, however virus replication is rapid, especially within the CNS, and can lead to an often, lethal outcome. Following intranasal infection of the mice with TC83-Luc, an attenuated Venezuelan equine encephalitis virus strain modified to expresses a luciferase gene; we are able to visualize virus replication within the brain at least three days before the development of clinical disease symptoms. Utilizing CNS invasion as a key encephalitic disease development endpoint we are able to quickly identify therapeutic and vaccine protection against TC83-Luc infection before clinical symptoms develop. With IVIS technology we are able to demonstrate the rapid and accurate testing of drug therapeutics and vaccines while reducing animal numbers and morbidity.

In Vivo Imaging Systems IVIS Detection of a Neuro-Invasive Encephalitic Virus

Utilizing luciferase and in vivo imaging systems (IVIS) as a novel means to identify disease endpoints before clinical developments occur. IVIS has allowed us to visualize in real time the invasion of encephalitic viruses over multiple days, providing a more accurate disease model for future study. It has also allowed us to identify the potential protective features of antivirals and vaccines faster than currently utilized animal models. The capability to utilize individual animals over multiple time points ensures reduced animal requirements, costs, and overall morbidity to the animals utilized ensuring a more humane and more scientific means of disease study.

In Vivo Imaging Systems (IVIS) il rilevamento di un neuro-invasiva Virus encephalitic

Modern advancements in imaging technology encourage further development and refinement in the way viral research is accomplished. Initially proposed by ...

4D Multimodality Imaging of Citrobacter rodentium Infections in Mice

This protocol outlines the steps required to longitudinally monitor a bioluminescent bacterial infection using composite 3D diffuse light imaging tomography with integrated &mu;CT (DLIT-&mu;CT) and the subsequent use of this data to generate a four dimensional (4D) movie of the infection cycle. To develop the 4D infection movies and to validate the DLIT-&mu;CT imaging for bacterial infection studies using an IVIS Spectrum CT, we used infection with bioluminescent C. rodentium, which causes self-limiting colitis in mice. In this protocol, we outline the infection of mice with bioluminescent C. rodentium and non-invasive monitoring of colonization by daily DLIT-&mu;CT imaging and bacterial enumeration from feces for 8 days.
The use of the IVIS Spectrum CT facilitates seamless co-registration of optical and &mu;CT scans using a single imaging platform. The low dose &mu;CT modality enables the imaging of mice at multiple time points during infection, providing detailed anatomical localization of bioluminescent bacterial foci in 3D without causing artifacts from the cumulative radiation. Importantly, the 4D movies of infected mice provide a powerful analytical tool to monitor bacterial colonization dynamics in vivo.

4D Multimodality Imaging of Citrobacter rodentium Infections in Mice

Multi-modality imaging is a valuable approach for studying bacterial colonization in small animal models. This protocol outlines infection of mice with bioluminescent Citrobacter rodentium and the longitudinal monitoring of bacterial colonization using composite 3D diffuse light imaging tomography with &mu;CT imaging to create a 4D movie of C. rodentium infection.

4D imaging multimodale di<em&gt; Citrobacter rodentium</em&gt; Infezioni in topi

This protocol outlines the steps required to  longitudinally monitor a bioluminescent bacterial infection using composite 3D diffuse light imaging ...

Monitoring Breast Cancer Growth and Metastatic Colony Formation in Mice using Bioluminescence

Breast cancer is a frequent heterogeneous malignancy and the second leading cause of mortality in women, mainly due to distant organ metastasis. Several animal models have been generated, including the widely used orthotopic mouse models, where cancer cells are injected into the mammary fat pad. However, these models cannot help monitor tumor growth kinetics and metastatic colonization. Cutting-edge tools to monitor cancer cells in real time in mice will significantly advance the understanding of tumor biology. 
Here, breast cancer cell lines stably expressing luciferase and green fluorescent protein (GFP) were established. Specifically, this technique contains two sequential steps initiated by measuring the luciferase activity in vitro and followed by the implantation of the cancer cells into mammary fat pads of nonobese diabetic-severe combined immunodeficiency (NOD-SCID) mice. After the injection, both the tumor growth and metastatic colonization are monitored in real time by the noninvasive bioluminescence imaging system. Then, the quantification of GFP-expressing metastases in the lungs will be examined by fluorescence microscopy to validate the observed bioluminescence results. This sophisticated system combining luciferase and fluorescence-based detection tools evaluates cancer metastasis in vivo, which has great potential for use in breast cancer therapeutics and disease management.

Here, we describe a noninvasive monitoring method involving luciferase and green fluorescent protein expression in various breast cancer cell lines. This protocol provides a technique to monitor tumor formation and metastatic colonization in real time in mice.

Monitoraggio della crescita del cancro al seno e della formazione di colonie metastatiche nei topi utilizzando la bioluminescenza

Breast cancer is a frequent heterogeneous malignancy and the second leading cause of mortality in women, mainly due to distant organ metastasis. Several ...

Ricerca sul cancro

Combined In vivo Optical and &#181;CT Imaging to Monitor Infection, Inflammation, and Bone Anatomy in an Orthopaedic Implant Infection in Mice

Multimodality imaging has emerged as a common technological approach used in both preclinical and clinical research. Advanced techniques that combine in vivo optical and &#956;CT imaging allow the visualization of biological phenomena in an anatomical context. These imaging modalities may be especially useful to study conditions that impact bone. In particular, orthopaedic implant infections are an important problem in clinical orthopaedic surgery. These infections are difficult to treat because bacterial biofilms form on the foreign surgically implanted materials, leading to persistent inflammation, osteomyelitis and eventual osteolysis of the bone surrounding the implant, which ultimately results in implant loosening and failure. Here, a mouse model of an infected orthopaedic prosthetic implant was used that involved the surgical placement of a Kirschner-wire implant into an intramedullary canal in the femur in such a way that the end of the implant extended into the knee joint. In this model, LysEGFP mice, a mouse strain that has EGFP-fluorescent neutrophils, were employed in conjunction with a bioluminescent Staphylococcus aureus strain, which naturally emits light. The bacteria were inoculated into the knee joints of the mice prior to closing the surgical site. In vivo bioluminescent and fluorescent imaging was used to quantify the bacterial burden and neutrophil inflammatory response, respectively. In addition, &#956;CT imaging was performed on the same mice so that the 3D location of the bioluminescent and fluorescent optical signals could be co-registered with the anatomical &#956;CT images. To quantify the changes in the bone over time, the outer bone volume of the distal femurs were measured at specific time points using a semi-automated contour based segmentation process. Taken together, the combination of in vivo bioluminescent/fluorescent imaging with &#956;CT imaging may be especially useful for the noninvasive monitoring of the infection, inflammatory response and anatomical changes in bone over time.

Combined In vivo Optical and  &#181;CT Imaging to Monitor Infection, Inflammation, and Bone Anatomy in an Orthopaedic Implant Infection in Mice

Combined optical and &#956;CT imaging in a mouse model of orthopaedic implant infection, utilizing a bioluminescent engineered strain of Staphylococcus aureus, provided the capability to noninvasively and longitudinally monitor the dynamics of the bacterial infection, as well as the corresponding inflammatory response and anatomical changes in the bone.

Combinato<em&gt; In vivo</em&gt; Optical e μCT Imaging Monitor per infezione, infiammazione, e Bone Anatomy in una infezione ortopedica impianto in topi

Multimodality imaging has emerged as a common technological approach used in both preclinical and clinical research. Advanced techniques that combine in ...

Medicina

Using Enhanced Green Fluorescence Protein-expressing Escherichia Coli to Assess Mouse Peritoneal Macrophage Phagocytosis

This manuscript describes a simple and reproducible method to perform a phagocytosis assay. The first part of this method involves building a pET-SUMO-EGFP vector (SUMO = small ubiquitin-like modifier) and expressing enhanced green fluorescence protein (EGFP) in Escherichia coli (BL21DE). EGFP-expressing E. coli is coincubated with macrophages for 1 h at 37 &#176;C; the negative control group is incubated on ice for the same amount of time. Then, the macrophages are ready for assessment. The advantages of this technique include its simple and straightforward steps, and phagocytosis can be measured by both flow cytometer and fluorescence microscope. The EGFP-expressing E. coli are stable and display a strong fluorescence signal even after the macrophages are fixed with paraformaldehyde. This method is not only suitable for the assessment of macrophage cell lines or primary macrophages in vitro but also suitable for the evaluation of granulocyte and monocyte phagocytosis in peripheral blood mononuclear cells. The results show that the phagocytic capability of peritoneal macrophages from young (eight-week-old) mice is higher than that of macrophages from aged (16-month-old) mice. In summary, this method measures macrophage phagocytosis and is suitable for studying the innate immune system function.

Using Enhanced Green Fluorescence Protein-expressing Escherichia Coli to Assess Mouse Peritoneal Macrophage Phagocytosis

Here, we present a protocol to assess mouse peritoneal macrophage phagocytosis using enhanced green fluorescence protein-expressing Escherichia coli.

Utilizzando Enhanced fluorescenza verde che esprimono proteine Escherichia Coli per valutare la fagocitosi dei macrofagi peritoneali del Mouse

This manuscript describes a simple and reproducible method to perform a phagocytosis assay. The first part of this method involves building a ...

Longitudinal Follow-Up of Urinary Tract Infections and Their Treatment in Mice using Bioluminescence Imaging

Urinary tract infections (UTI) rank among the most common bacterial infections in humans and are routinely treated with empirical antibiotics. However, due to increasing microbial resistance, the efficacy of the most used antibiotics has declined. To find alternative treatment options, there is a great need for a better understanding of the UTI pathogenesis and the mechanisms that determine UTI susceptibility. In order to investigate this in an animal model, a reproducible, non-invasive assay to study the course of UTI is indispensable.
For years, the gold standard for the enumeration of bacterial load has been the determination of Colony Forming Units (CFU) for a particular sample volume. This technique requires post-mortem organ homogenates and serial dilutions, limiting data output and reproducibility. As an alternative, bioluminescence imaging (BLI) is gaining popularity to determine the bacterial load. Labeling pathogens with a lux operon allow for the sensitive detection and quantification in a non-invasive manner, thereby enabling longitudinal follow-up. So far, the adoption of BLI in UTI research remains limited.
This manuscript describes the practical implementation of BLI in a mouse urinary tract infection model. Here, a step-by-step guide for culturing bacteria, intravesical instillation and imaging is provided. The in vivo correlation with CFU is examined and a proof-of-concept is provided by comparing the bacterial load of untreated infected animals with antibiotic-treated animals. Furthermore, the advantages, limitations, and considerations specific to the implementation of BLI in an in vivo UTI model are discussed. The implementation of BLI in the UTI research field will greatly facilitate research on the pathogenesis of UTI and the discovery of new ways to prevent and treat UTI.

This manuscript describes the intravesical administration of uropathogenic bacteria with a lux operon to induce a urinary tract infection in mice and subsequent longitudinal in vivo analysis of the bacterial load using bioluminescence imaging.

Follow-up longitudinale delle infezioni del tratto urinario e loro trattamento nei topi utilizzando l'imaging a bioluminescenza

Urinary tract infections (UTI) rank among the most common bacterial infections in humans and are routinely treated with empirical antibiotics. However, ...

Rilevamento della colonizzazione di Escherichia Coli enteroemorragica in murino Host di sistema Non invasivo In Vivo bioluminescenza

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