This project was supported by Midwestern University, IL Office of Research and Sponsored Programs (ORSP) and Midwestern University College of Dental Medicine-Illinois (CDMI).

1. HSV-Stämme und Handhabung Hinweis: Recombinant kein Ausbreiten HSV-1 (KOS) gL86 und HSV-2 (KOS) 333gJ - mit beta-Galactosidase - Reporteraktivität verwendet wurden von V. Twiari 36,37 zur Verfügung gestellt. <ol><li> Verwenden Sie Virus aus einem Los und bei -80 ° C bei einer 1: 1-Verhältnis von Dulbecco modifiziertem Eagle-Medium (DMEM) mit 20% fötalem Rinderserum (FBS) und Magermilch bis zur Verwendung. Vor viral Menge Lagerung, Viruskonzentration von o - Nitrophenyl-β-D-galactopyranosid (ONPG) und 5-Brom-4-chlor-3-indolyl-β-D-galactopyranosid (X-Gal) Assay bestimmen. </li><li> Bestimmen die Lebensfähigkeit des Virus und Multiplizität der Infektion (MOI) von X-Gal - Färbung für jeden experimentellen Testlauf unter Verwendung von Reporter - Virus Eintrag Assay, wie vorstehend beschrieben (Figur 1) 14. </li><li> Verdünnte-Virus (Opt-MEM), um die gewünschten MOI. Fix Monolayern (Paraformaldehyd, 0,5 ml / Vertiefung) vor der Färbung. Platzieren Sie die Lebensfähigkeit des Virus Kontrollen in einem separaten microtiter Platte parallel zu polymikrobiellen Testplatten. </li></ol> 2. HeLa 299 Cell Handling <ol><li> Wachsen bei 37 ° C, 5% CO 2 in DMEM mit 4,5 g / L Glucose, 10% hitzeinaktiviertes fötales Rinderserum (FBS), Gentamicin (50 ug / ml) und L-Glutamin. Passage-Zellen bei 80% Konfluenz mit Trypsin-Lösung (Ethylendiamintetraessigsäure, 0,53 M EDTA; 0,05% Trypsin; 5 ml / Kolben). </li></ol> 3. C. albicans Handhabung Hinweis: C. albicans aus einem klinischen Labor Quelle erhalten wird bei -80 ° C in Remmel Magermilch 2x Medium gespeichert. <ol><li> Kultur gefroren Lager auf Sabouraud-Dextrose-Medium (37 ° C). Nach 24 Stunden Subkultur der C. albicans auf Fungisel Medium (37 ° C; 48 h) zur Verwendung. </li><li> Generieren Keimschlauch (GT) Formen (Pick repräsentative Kolonien; 3 ml FBS; 3 h; 37 ° C; Abs 600, 0,3). Nach der Inkubation waschen GT (HBSS; 2x; 4000 · g). In gewaschen GT erwärmt HBSS (37 &amp;# 176; C; 0,32 Abs 600). GT Formulare sollten 99% der Zellen beobachtet, wie er durch Haemocytometerzählung bestimmt. </li><li> Machen Sie Hefeform (YF) Stoffsuspensionen durch Picken Vertreter Fungisel Kolonien (HBSS, 3 ml; 0,32 Abs 600). Zählen Sie die Anzahl von YF Formen / ml unter Verwendung von mikroskopisch einer Zählkammer. YF Formulare sollten 99% der Zellen beobachtet, wie er durch Haemocytometerzählung bestimmt. </li><li> Machen Sie arbeiten Pilz-Lager (250 ul GT oder YF Lager in 25 ml HBSS; 37 ° C; 10 5 KBE / ml) </li></ol> 4. S. aureus Handhabung <ol><li> Shop S. aureus ATCC 25923 (-80 ° C; Remmel Milch 2x abschöpfen). Kultur auf Schafblut-Agar (5%; 37 ° C; 24 h). Wählen repräsentative Kolonien und übertragen Salze Mannit Medium innerhalb von 2 Tagen für Lager (37 ° C; 18 h). </li><li> Machen Sie S. aureus Stoffsuspension (3 ml HBSS; 1.32 Abs 600; 10 8 KBE / ml) <ol><li> Machen Sie S. Arbeits aureus Lager (100 &amp; mgr; lder Lager in 25 ml HBSS; 10 5 CFU / ml). </li></ol></li></ol> 5. Candida und S. aureus Suspensions <ol><li> Machen Sie Misch C. albicans und S. aureus - Suspension (250 ul YF oder GT Lager und 100 &amp; mgr; l S. aureus Lager in 25 ml HBSS). </li></ol> 6. polymikrobiellen Biofilm-Assay <ol><li> Seed Platten mit 96 Vertiefungen mit 200 ul 2 x 10 5 HeLa - Zellen / ml (85% Konfluenz Ebene). Gesteinsplatten (30 - 45 min; 37 ° C) vor der Inkubation (37 ° C; 5% CO 2 -Inkubator; 18 h). Wash Monolayern (1x; Opt-MEM) dann Samen mit HSV (HSV-1 (KOS) gL86 oder HSV-2 (KOS) 33 gJ - in 100 ul Opt-MEM; MOI 50 und 10). Inkubieren Platten (3 h; 37 ° C; 5% CO 2). Verwenden Sie nur einen Virusstamm pro Tag. </li><li> Waschen infizierten Monoschichten (1x; phosphatgepufferte Salzlösung (PBS) mit Mg +2 und Ca +2; 100 &amp; mgr; l). Ersetzen PBS mit warmem HBSS verlassen 25 &amp; #181; l in jeder Vertiefung. <ol><li> In YF, GT und / oder S. aureus Arbeits Suspensionen (100 &amp; mgr; l, Ziel zu Zellenverhältnis = 5: 1; n = 16) dar . Wie in Tabelle 1 angegeben inkubieren Platten (static; 30 min; 37 ° C; 5% CO 2). </li></ol></li><li> Nach der Inkubation aspirate eine Spalte zu einer Zeit sofort mit 300 &amp; mgr; l PBS mit Mg +2 und Ca +2 Nachfüllen. Wiederholen Sie diesen Schritt zweimal fügen Sie dann Radio-Immunopräzipitation Lysepuffer (RIPA; Filter sterilisiert; 200 ul einer Verdünnung von 1:50). </li><li> Verreiben schnell die HeLa Zelllysat anschießend auf 50 &amp; mgr; l Mannit Salze (MS) und / oder Fungisel (F) Medien (Abbildung 2). Verbreiten Sie das Lysat mit einem Glasstab gebogen in einem 90 ° Winkel mit. Inkubiere die Platten (18 h bei 37 ° C). zählen manuell die Anzahl der Kolonien pro Platte. Kontrollen bestehen aus S. aureus und / oder C. albicans Einhaltung der HSV-nicht infizierten HeLa - Zellen. </li></ol> 7. Imaging Studies &lt;/ P&gt; <ol><li> Waschen Sie jede Runde Deckglas (12 mm; 50 ml Aceton in 100-ml-Becher). Trockene und sterilisieren Deck (Kimwipes; Petrischalen aus Glas). Legen Sie trockene sterile Deckgläschen in die Vertiefungen von sterilen 24-Well-Platten mit Alkohol Flamme sterilisierten Pinzette. </li><li> Hinzufügen HeLa-Zellen (1 ml; 5x Volumen für 96-Well-Platten verwendet werden) in die Vertiefungen von 24-Well-Platten die gewaschenen sterilen Rundglasplättchen enthält. Fügen Sie die Viren, Bakterien und Pilze nach der Vorlage (Tabelle 2) bei 5x das Volumen der 96 - Well - Platten verwendet, dann brüten und Verfahren , wie 6.2.1 bis 6.4 oben in den Schritten beschrieben. </li><li> Nach dem letzten Waschen, Fixieren der Zellen für die Mikroskopie durch die Folie mit Methanol überschwemmen und ermöglicht es zu verdampfen. Lagern Sie die Platten bei RT bis zur Färbung. </li><li> Für Hellfeldmikroskopie (1,000x letzte Originalvergrößerung) füllen die Vertiefungen mit Methanol fixierten Deck mit entsalztem Wasser enthält. Ab sofort absaugen Wasser. Cover jede Deckglas mit Grams Kristallviolett. Wash Deckgläser frei von nicht gebundenen Fleck (VE-Wasser). Dry Deck in situ haften sie dann mit harten Satz Eindeckmediums zu einem markierten Schieber (Abbildung 3). </li><li> Für Fluoreszenzmikroskopie (100x Objektiv; 1,000x letzte Originalvergrößerung) waschen Deckgläser frei im wesentlichen aus Methanol, wie in Schritt 7.4 beschrieben. Trocknen Sie die Deckgläser in den Vertiefungen. <ol><li> die Deckgläser Nach dem Trocknen entfernen und sie auf markierten Folien. Dann fügen Sie eine ausreichende Menge an 1:20 Verdünnung von Fluorescein (FITC) -konjugierte Herpes Simplex Virus Typ 1 + 2 gD-Antikörper das Deckglas zu bedecken (1 - 5 ul). </li><li> Inkubieren der Objektträger in einer feuchten Kammer bei 37 ° C für 30 min. Nach der Inkubation waschen Sie die Deckgläser in vier Änderungen von PBS. </li><li> Nach dem letzten Waschen, bringen Sie das Deckglas an die markierte Folie. Fleck mit 4 &#39;, 6-Diamidino-2-phenylindol (DAPI; Feuchtigkeitskammer; 37 ° C für 30 min). Nach der Inkubation waschen Sie die Deckgläser in 4 changes von PBS, dann zu dem markierten Schlitten mit harten Satz Eindeckmediums befestigen. </li><li> Ermöglichen die Befestigungsmittel für 24 h bei RT im Dunkeln zu heilen. Untersuchen Sie die Deckgläser unter Öl-Objektiv entweder auf einem Hellfeld-Mikroskop oder Fluoreszenzmikroskop mit FITC und DAPI Cutoff-Filter. Untersuchen Sie Bilder von mindestens 50 Felder (100 Zellen pro Organismus Minimum) für die Co-Lokalisierung (Abbildung 4). </li></ol></li></ol>

The authors have nothing to disclose.

Derzeit liegen keine Informationen über komplexe Wechselwirkungen zwischen permanent zu semi-permanenten Mitglieder des Host microbiome , die mehrere taxonomische Domänen kreuzen, dh prokaryotischen, eukaryotischen und viral. Deshalb entwickelten wir ein neuartiges in System - vitro - Modell Biofilm Einleitung von S. zu studieren aureus und C. albicans auf HSV-1 oder HSV-2 infizierten HeLa 229 (HeLa - Zellen) 38. Die HeLa-Zellen Modellsystem stellt einen...

<html> Der menschliche microbiome umfasst unterschiedliche Organismen aus verschiedenen taxonomischen Königreiche, die im Körper geografischen Regionen teilen. Die Einhaltung der Zelloberflächen ist ein wichtiger erster Schritt in die Biofilmbildung, die Teil des microbiome Kolonisierung ist. Eingeschlossen in die microbiome können Viren sein, die chronische und persistente Infektionen verursachen. Die chronische Zellinfektion durch diese Viren kann eine Veränderung in mutmaßlichen Rezeptor Verfügbarkeit führen. 1,2 Zusätzlich Zelleintritt durch intrazelluläre Erreger auch Wirts Membranfluidität / Hydrophobizität, die wiederum verändern können Anbringung weiterer microbiome Mitglieder, einschließlich Bakterien und Pilzen beeinflussen könnten . Um die Wechselwirkungen zu verstehen, die zwischen diesen mehrere Krankheitserreger, die Co-Lokalisierung in den gleichen Regionen des menschlichen Wirts auftreten können, müssen wir die Wechselwirkung von Krankheitserregern zu studieren können, die das Spektrum von taxonomischen Königreiche, die an der Schleimhautoberfläche darstellen. t &quot;&gt; Die Herpesviridae sind eine Familie von Mikroben in 100% der Menschen als ständige Mitglieder des microbiome 3,4. Darüber hinaus können sie auch beide beharrlich vergossen werden in Gegenwart und in Abwesenheit von Symptomen. Insbesondere Herpes - simplex - Virus-1 und Herpes-simplex-Virus-2 (HSV-1 und HSV-2, jeweils) sind permanent Mitglieder der microbiome im oronasopharynx und Genitaltrakt. in immunkompetenten Individuen sowohl HSV-1 und HSV-2 verursachen Gingivostomatitis, sowie Genital - Herpes 5-8. an diesen Stellen verursacht HSV eine latente durch chronische persistente asymptomatischen Virus gekennzeichnet Infektion zu vergießen 9. Eintritt von HSV in Zellen führt zu Veränderungen in der Oberflächenexpression von nectins, Heparansulfat, Lipid Rafts und Herpes - Virus Eintrag Mediator / Tumor - Nekrose Faktor - Rezeptor (HVEM / TNFr) 25.10. Diese potenziell gemeinsamen Rezeptoren für einige Bakterien und Pilze darstellen, zB S. aureus und C. albicans, die während opportunistische Erreger,können auch als Mitglieder der Schleimhaut microbiome des oronasopharynx 26,27 befinden. Innerhalb des oronasopharynx S. aureus und C. albicans belegen zwei verschiedene Stellen der Besiedlung. In Hosts mit natürlichen Zähnen wird die Mundschleimhaut durch HSV-1 geteilt und C. albicans, während die vorderen Nasen nares werden von S. besetzt aureus 28. Doch trotz in - vitro - Ergebnisse , dass S. aureus hält sich an den Mund Epithelzellen, 29,30 S. aureus ist selten von oralen Proben isoliert , wenn die normale Gewebe vorhanden 29,30 ist. Es ist wenig bekannt , Genitaltrakt über Co-Kolonisation Nischen jenseits der klinischen Befunde , dass S. aureus ist mit aerober Vaginitis verbunden sind , gekennzeichnet durch Genital - Entzündung, Entladung und Dyspareunie, während C. albicans erzeugt Schleimhautläsionen ähnlich der in der Mundhöhle beobachtet 31-35. Obwohl also diese Mitglieder der Mund- und Genital microbiome Quer taxonomischen Reiche wenig bekannt ist , ihre Interaktion , wie sie Auswirkungen ihrer Fähigkeit , die Bildung von Biofilmen durch die Einhaltung der Wirtszelloberfläche 5 über einzuleiten. Dieses Protokoll wurde effektiv die funktionellen Folgen der Co-Kolonisation / Infektion zu bestimmen, angewandt.

<table border="0" cellpadding="0" cellspacing="0" width="1185">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">C.albicans</td>
			<td style="width:195px;"></td>
			<td style="width:119px;"></td>
			<td style="width:481px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">BBL Sabouraud Dextrose</td>
			<td style="width:195px;">BD</td>
			<td style="width:119px;">211584</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Fungisel Agar</td>
			<td style="width:195px;">Dot Scientific</td>
			<td style="width:119px;">7205A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">S.aureus</td>
			<td style="width:195px;"></td>
			<td style="width:119px;"></td>
			<td style="width:481px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Mannitol Salt Agar</td>
			<td style="width:195px;">Troy Biologicals</td>
			<td style="width:119px;">7143B</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Sheep blood agar</td>
			<td style="width:195px;">Troy Biologicals</td>
			<td style="width:119px;">221239</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Hela cells</td>
			<td style="width:195px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:391px;">1xDMEM (Dubelcco&#39;s Modified Eagle Medium, with 4.5 g/L glucose and L-glutamine, without sodium pyruvate</td>
			<td style="width:195px;">Corning</td>
			<td style="width:119px;">10-017-CM</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Gentamicin 50mg/ml</td>
			<td style="width:195px;">Sigma</td>
			<td style="width:119px;">1397</td>
			<td>50&#181;g/ml final concentration in the complete DMEM</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:391px;">Trypsin EDTA (0.05% Trypsin, 0.53M EDTA)Solution 1X</td>
			<td style="width:195px;">Corning</td>
			<td>25-052-CI</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Fetal Bovine Serum</td>
			<td style="width:195px;">Atlanta Biologicals</td>
			<td style="width:119px;">S11150</td>
			<td>10% final concentration in the complete DMEM</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Other medium and reagents</td>
			<td style="width:195px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">ONPG</td>
			<td style="width:195px;">Thermo Scientific</td>
			<td style="width:119px;">34055</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Ultra-Pure X gal</td>
			<td style="width:195px;">Invitrogen</td>
			<td style="width:119px;">15520-018</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">1x HBSS (Hanks&#39; Balanced Salt Solution)</td>
			<td style="width:195px;">Corning</td>
			<td style="width:119px;">20-021-CV</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">1XPBS</td>
			<td style="width:195px;">Dot Scientific</td>
			<td style="width:119px;">30042-500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">RIPA Lysis</td>
			<td style="width:195px;">Life Technologies</td>
			<td style="width:119px;">89901</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Staining</td>
			<td style="width:195px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Methanol</td>
			<td style="width:195px;">Fisher Scientific</td>
			<td style="width:119px;">A433P-4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">HSV 1&#38;2, specific for gD</td>
			<td style="width:195px;">ViroStat</td>
			<td style="width:119px;">196</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">DAPI</td>
			<td style="width:195px;">SIGMA</td>
			<td style="width:119px;">D8417-5MG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Gram Crystal Violet</td>
			<td style="width:195px;">Troy Biologicals</td>
			<td style="width:119px;">212527</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Supplies</td>
			<td style="width:195px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="29">
			<td height="29" style="height:29px;width:391px;">Petri dish 100X15</td>
			<td style="width:195px;">Dot Scientific</td>
			<td style="width:119px;">229693&#160;</td>
			<td></td>
		</tr>
		<tr height="29">
			<td height="29" style="height:29px;width:391px;">Petri dish 150X15</td>
			<td style="width:195px;">Kord Valmark</td>
			<td style="width:119px;">2902</td>
			<td></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:391px;">96-Well plates</td>
			<td style="width:195px;">Evergreen Scientific</td>
			<td style="width:119px;">222-8030-01F</td>
			<td></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:391px;">24-well plates</td>
			<td style="width:195px;">Evergreen Scientific</td>
			<td style="width:119px;">222-8044-01F</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Culture tubes 100x13</td>
			<td style="width:195px;">Thomas Scientific</td>
			<td style="width:119px;">9187L61</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">Cover slip circles, 12mm</td>
			<td style="width:195px;">Deckglaser</td>
			<td style="width:119px;">CB00120RA1</td>
			<td></td>
		</tr>
	</tbody>
</table>

determination of biofilm initiation on virus-infected cells by bacteria and fungi

Die Studie von polymikrobiellen Interaktionen über die taxonomische Königreiche, die Pilze, Bakterien und Viren sind nicht zuvor in Bezug auf, wie virale Mitglieder des microbiome beeinflussen nachfolgende Mikroben-Interaktionen mit diesen Virus infizierten Wirtszellen untersucht worden. Das Zusammenleben von Virus mit Bakterien und Pilzen besteht hauptsächlich darin, die auf den Schleimhäuten der Mundhöhle und des Genitaltrakts. Mucosal Zellen, insbesondere solche mit persistenten chronischen oder persistenten latenten Virusinfektionen, könnte einen erheblichen Einfluss auf die Mitglieder des microbiome durch Virus Veränderung in der Anzahl und Art der Rezeptoren zum Ausdruck gebracht haben. Änderung in Wirtszellmembran Architektur in veränderter Fähigkeit der nachfolgenden Mitglieder der normalen Flora und opportunistischen Erregern würde den ersten Schritt in die Biofilmbildung, das heißt, die Einhaltung zu initiieren. Diese Studie beschreibt ein Verfahren zur Quantifizierung und visuelle Untersuchung des HSV Wirkung auf die Einleitung BIOFILm - Bildung (Adhärenz) von S. aureus und C. albicans.

Der Grad der Zuverlässigkeit der Daten , die aus System in diesem Bericht beschrieben wird , in Abbildung 2 af 38 gezeigt. Durch die Verwendung dieses Systems die Modulation von Staphylokokken und Pilz Wechselwirkung mit viral infizierte Zellen und deren Wirkung auf jedes Anhaften des anderen können abgegrenzt werden. Diese Arten von Studien erfordern mikroskopische Untersuchung der Wechselwirkung , wie in den 3 und 4 gezeig...

Watch this Scientific Journal Video about Determination of Biofilm Initiation on Virus-infected Cells by Bacteria and Fungi at JoVE.com

Determination of Biofilm Initiation on Virus-infected Cells by Bacteria and Fungi

A method is described herein for the determination of inter-Kingdom association and competition (bacterial and fungal) for adherence to virus-infected HeLa cell monolayers. This protocol can be extended to multiple combinations of prokaryotes, eukaryotes, and viruses.

Bestimmung von Biofilm Initiation auf Virus-infizierte Zellen durch Bakterien und Fungi

The study of polymicrobial interactions across the taxonomic kingdoms that include fungi, bacteria and virus have not been previously examined with ...

determination-biofilm-initiation-on-virus-infected-cells-bacteria

Research

JoVE Journal

Immunology and Infection

9.6K Aufrufe.  Midwestern University. A method is described herein for the determination of inter-Kingdom association and competition (bacterial and fungal) for adherence to virus-infected HeLa cell monolayers. This protocol can be extended to multiple combinations of prokaryotes, eukaryotes, and viruses.

Serie: Determination of Biofilm Initiation on Virus-infected Cells by Bacteria and Fungi

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 und Saccharomyces cerevisiae Biofilm im Flow Cells

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

Forschung

Immunologie und Infektion

Microtiter Dish Biofilm Formation Assay

Biofilms are communities of microbes attached to surfaces, which can be found in medical, industrial and natural settings. In fact, life in a biofilm probably represents the predominate mode of growth for microbes in most environments. Mature biofilms have a few distinct characteristics. Biofilm microbes are typically surrounded by an extracellular matrix that provides structure and protection to the community. Microbes growing in a biofilm also have a characteristic architecture generally comprised of macrocolonies (containing thousands of cells) surrounded by fluid-filled channels. Biofilm-grown microbes are also notorious for their resistance to a range of antimicrobial agents including clinically relevant antibiotics.
The microtiter dish assay is an important tool for the study of the early stages in biofilm formation, and has been applied primarily for the study of bacterial biofilms, although this assay has also been used to study fungal biofilm formation. Because this assay uses static, batch-growth conditions, it does not allow for the formation of the mature biofilms typically associated with flow cell systems. However, the assay has been effective at identifying many factors required for initiation of biofilm formation (i.e, flagella, pili, adhesins, enzymes involved in cyclic-di-GMP binding and metabolism) and well as genes involved in extracellular polysaccharide production. Furthermore, published work indicates that biofilms grown in microtiter dishes do develop some properties of mature biofilms, such a antibiotic tolerance and resistance to immune system effectors.
This simple microtiter dish assay allows for the formation of a biofilm on the wall and/or bottom of a microtiter dish. The high throughput nature of the assay makes it useful for genetic screens, as well as testing biofilm formation by multiple strains under various growth conditions. Variants of this assay have been used to assess early biofilm formation for a wide variety of microbes, including but not limited to, pseudomonads, Vibrio cholerae, Escherichia coli, staphylocci, enterococci, mycobacteria and fungi.
In the protocol described here, we will focus on the use of this assay to study biofilm formation by the model organism Pseudomonas aeruginosa. In this assay, the extent of biofilm formation is measured using the dye crystal violet (CV). However, a number of other colorimetric and metabolic stains have been reported for the quantification of biofilm formation using the microtiter plate assay. The ease, low cost and flexibility of the microtiter plate assay has made it a critical tool for the study of biofilms.

The assay describes a rapid means to measure early biofilm formation in bacteria and fungi. This method uses a microtiter plate as the substratum for microbial biofilm formation, and the biofilm is visualized using crystal violet strain. The assay provides either a qualitative or quantitative assay for early biofilm formation.

Mikrotiterschale Biofilmbildung Assay

Biofilms are communities of microbes attached to surfaces, which can be found in medical, industrial and natural settings.  In fact, life in a biofilm ...

Following Cell-fate in E. coli After Infection by Phage Lambda

The system comprising bacteriophage (phage) lambda and the bacterium E. coli has long served as a paradigm for cell-fate determination1,2. Following the simultaneous infection of the cell by a number of phages, one of two pathways is chosen: lytic (virulent) or lysogenic (dormant)3,4. We recently developed a method for fluorescently labeling individual phages, and were able to examine the post-infection decision in real-time under the microscope, at the level of individual phages and cells5. Here, we describe the full procedure for performing the infection experiments described in our earlier work5. This includes the creation of fluorescent phages, infection of the cells, imaging under the microscope and data analysis. The fluorescent phage is a "hybrid", co-expressing wild- type and YFP-fusion versions of the capsid gpD protein. A crude phage lysate is first obtained by inducing a lysogen of the gpD-EYFP (Enhanced Yellow Fluorescent Protein) phage, harboring a plasmid expressing wild type gpD. A series of purification steps are then performed, followed by DAPI-labeling and imaging under the microscope. This is done in order to verify the uniformity, DNA packaging efficiency, fluorescence signal and structural stability of the phage stock. The initial adsorption of phages to bacteria is performed on ice, then followed by a short incubation at 35&deg;C to trigger viral DNA injection6. The phage/bacteria mixture is then moved to the surface of a thin nutrient agar slab, covered with a coverslip and imaged under an epifluorescence microscope. The post-infection process is followed for 4 hr, at 10 min interval. Multiple stage positions are tracked such that ~100 cell infections can be traced in a single experiment. At each position and time point, images are acquired in the phase-contrast and red and green fluorescent channels. The phase-contrast image is used later for automated cell recognition while the fluorescent channels are used to characterize the infection outcome: production of new fluorescent phages (green) followed by cell lysis, or expression of lysogeny factors (red) followed by resumed cell growth and division. The acquired time-lapse movies are processed using a combination of manual and automated methods. Data analysis results in the identification of infection parameters for each infection event (e.g. number and positions of infecting phages) as well as infection outcome (lysis/lysogeny). Additional parameters can be extracted if desired.

Following Cell-fate in E. coli After Infection by Phage Lambda

This article describes the procedure for preparing a fluorescently-labeled version of bacteriophage lambda, infection of E. coli bacteria, following the infection outcome under the microscope, and analysis of infection results.

Nach Cell-Schicksal<em&gt; E. coli</em&gt; Nach Infektion mit Phagen

The system comprising bacteriophage (phage) lambda and the bacterium E. coli has long served as a paradigm for cell-fate determination1,2. Following the ...

Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction

Lipopolysaccharide (LPS) is a major component of Gram-negative bacterial outer membranes. It is a tripartite molecule consisting of lipid A, which is embedded in the outer membrane, a core oligosaccharide and repeating O-antigen units that extend outward from the surface of the cell1, 2. LPS is an immunodominant molecule that is important for the virulence and pathogenesis of many bacterial species, including Pseudomonas aeruginosa, Salmonella species, and Escherichia coli3-5, and differences in LPS O-antigen composition form the basis for serotyping of strains. LPS is involved in attachment to host cells at the initiation of infection and provides protection from complement-mediated killing; strains that lack LPS can be attenuated for virulence6-8. For these reasons, it is important to visualize LPS, particularly from clinical isolates. Visualizing LPS banding patterns and recognition by specific antibodies can be useful tools to identify strain lineages and to characterize various mutants. 
In this report, we describe a hot aqueous-phenol method for the isolation and purification of LPS from Gram-negative bacterial cells. This protocol allows for the extraction of LPS away from nucleic acids and proteins that can interfere with visualization of LPS that occurs with shorter, less intensive extraction methods9. LPS prepared this way can be separated by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) and directly stained using carbohydrate/glycoprotein stains or standard silver staining methods. Many anti-sera to LPS contain antibodies that cross-react with outer membrane proteins or other antigenic targets that can hinder reactivity observed following Western immunoblot of SDS-PAGE-separated crude cell lysates. Protease treatment of crude cell lysates alone is not always an effective way of removing this background using this or other visualization methods. Further, extensive protease treatment in an attempt to remove this background can lead to poor quality LPS that is not well resolved by any of the aforementioned methods. For these reasons, we believe that the following protocol, adapted from Westpahl and Jann10, is ideal for LPS extraction.

We describe a modified hot aqueous-phenol extraction method for purifying lipopolysaccharide (LPS) from Gram-negative bacteria. Once extracted, the LPS can be subsequently analyzed by SDS-PAGE and visualized by direct staining or Western immunoblot.

Reinigung und Visualisierung von Lipopolysaccharid aus Gram-negativen Bakterien durch heiße wäßrige-Phenol-Extraktion

Lipopolysaccharide (LPS)  is a major component of Gram-negative bacterial outer membranes. It is a tripartite molecule consisting of  lipid A, which is ...

Use of Image Cytometry for Quantification of Pathogenic Fungi in Association with Host Cells

Studies of the cellular pathogenesis mechanisms of pathogenic yeasts such as Candida albicans, Histoplasma capsulatum, and Cryptococcus neoformans commonly employ infection of mammalian hosts or host cells (i.e. macrophages) followed by yeast quantification using colony forming unit analysis or flow cytometry. While colony forming unit enumeration has been the most commonly used method in the field, this technique has disadvantages and limitations, including slow growth of some fungal species on solid media and low and/or variable plating efficiencies, which is of particular concern when comparing growth of wild-type and mutant strains. Flow cytometry can provide rapid quantitative information regarding yeast viability, however, adoption of flow cytometric detection for pathogenic yeasts has been limited for a number of practical reasons including its high cost and biosafety considerations. Here, we demonstrate an image-based cytometric methodology using the Cellometer Vision (Nexcelom Bioscience, LLC) for the quantification of viable pathogenic yeasts in co-culture with macrophages. Our studies focus on detection of two human fungal pathogens: Histoplasma capsulatum and Candida albicans. H. capsulatum colonizes alveolar macrophages by replicating within the macrophage phagosome, and here, we quantitatively assess the growth of H. capsulatum yeasts in RAW 264.7 macrophages using acridine orange/propidium iodide staining in combination with image cytometry. Our method faithfully recapitulates growth trends as measured by traditional colony forming unit enumeration, but with significantly increased sensitivity. Additionally, we directly assess infection of live macrophages with a GFP-expressing strain of C. albicans. Our methodology offers a rapid, accurate, and economical means for detection and quantification of important human fungal pathogens in association with host cells.

Here, we demonstrate how image cytometry can be used for quantification of pathogenic fungi in association with host cells in culture. This technique can be used as an alternative to CFU enumeration.

Verwendung Bildzytometrie zur Quantifizierung von pathogenen Pilzen in Verbindung mit Wirtszellen

Studies of the cellular pathogenesis mechanisms of pathogenic yeasts such as Candida albicans, Histoplasma capsulatum, and Cryptococcus neoformans ...

Application of Fluorescent Nanoparticles to Study Remodeling of the Endo-lysosomal System by Intracellular Bacteria

Fluorescent nanoparticles (NPs) with desirable chemical, optical and mechanical properties are promising tools to label intracellular organelles. Here, we introduce a method using gold-BSA-rhodamine NPs to label the endo-lysosomal system of eukaryotic cells and monitor manipulations of host cellular pathways by the intracellular pathogen Salmonella enterica. The NPs were readily internalized by HeLa cells and localized in late endosomes/lysosomes. Salmonella infection induced rearrangement of the vesicles and accumulation of NPs in Salmonella-induced membrane structures. We deployed the Imaris software package for quantitative analyses of confocal microscopy images. The number of objects and their size distribution in non-infected cells were distinct from the ones in Salmonella-infected cells, indicating extremely remodeling of the endo-lysosomal system by WT Salmonella.

This article describes methods for the synthesis and fluorescent labeling of nanoparticles (NPs). The NPs were applied in pulse-chase experiments to label the endo-lysosomal system of eukaryotic cells. Manipulation of the endo-lysosomal system by activities of the intracellular pathogen Salmonella enterica were followed by live cell imaging and quantified.

Die Anwendung der Fluoreszenz-Nanopartikel zur Umgestaltung des Endo-lysosomalen System-Studie durch intrazelluläre Bakterien

Fluorescent nanoparticles (NPs) with desirable chemical, optical and mechanical properties are promising tools to label intracellular organelles. Here, we ...

T Cells Capture Bacteria by Transinfection from Dendritic Cells

Recently, we have shown, contrary to what is described, that CD4+ T cells, the paradigm of adaptive immune cells, capture bacteria from infected dendritic cells (DCs) by a process called transinfection. Here, we describe the analysis of the transinfection process, which occurs during the course of antigen presentation. This process was unveiled by using CD4+ T cells from transgenic OTII mice, which bear a T cell receptor (TCR) specific for a peptide of ovoalbumin (OVAp), which therefore can form stable immune complexes with infected dendritic cells loaded with this specific OVAp. The dynamics of green fluorescent protein (GFP)-expressing bacteria during DC-T cell transmission can be monitored by live-cell imaging and the quantification of bacterial transinfection can be performed by flow cytometry. In addition, transinfection can be quantified by a more sensitive method based in the use of gentamicin, a non-permeable aminoglycoside antibiotic killing extracellular bacteria but not intracellular ones. This classical method has been used previously in microbiology to study the efficiency of bacterial infections. We hereby explain the protocol of the complete process, from the isolation of the primary cells to the quantification of transinfection.

Here a protocol is presented to measure bacterial capture by CD4+ T cells which occurs during antigen presentation via transinfection from pre-infected dendritic cells (DC). We show how to perform the necessary steps: isolation of primary cells, infection of DC, DC/T cell conjugate formation, and measurement of bacterial T cell transfection.

T-Zellen erfassen Bakterien durch Transinfection von dendritischen Zellen

Recently, we have shown, contrary to what is described, that CD4+ T cells, the paradigm of adaptive immune cells, capture bacteria from infected dendritic ...

Phenotypic and Functional Analysis of Activated Regulatory T Cells Isolated from Chronic Lymphocytic Choriomeningitis Virus-infected Mice

Regulatory T (Treg) cells, which express Foxp3 as a transcription factor, are subsets of CD4+ T cells. Treg cells play crucial roles in immune tolerance and homeostasis maintenance by regulating the immune response. The primary role of Treg cells is to suppress the proliferation of effector T (Teff) cells and the production of cytokines such as IFN-&#947;, TNF-&#945;, and IL-2. It has been demonstrated that Treg cells&#39; ability to inhibit the function of Teff cells is enhanced during persistent pathogen infection and cancer development. To clarify the function of Treg cells under resting or inflamed conditions, a variety of in vitro suppression assays using mouse or human Treg cells have been devised. The main aim of this study is to develop a method to compare the differences in phenotype and suppressive function between resting and activated Treg cells. To isolate activated Treg cells, mice were infected with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13), a chronic strain of LCMV. Treg cells isolated from the spleen of LCMV CL13-infected mice exhibited both the activated phenotype and enhanced suppressive activity compared with resting Treg cells isolated from na&#239;ve mice. Here, we describe the basic protocol for ex vivo phenotype analysis to distinguish activated Treg cells from resting Treg cells. Furthermore, we describe a protocol for the measurement of the suppressive activity of fully activated Treg cells.

Here, we describe a protocol to analyze the phenotype of regulatory T (Treg) cells isolated from na&#239;ve and chronic lymphocytic choriomeningitis virus-infected mice. In addition, we provide a process to evaluate the suppressive activity of the Treg cells.

Die phänotypische und funktionale Analyse von aktivierten regulatorischen T-Zellen isoliert von chronischer lymphatischer Choriomeningitisvirus-infizierte Mäuse

Regulatory T (Treg) cells, which express Foxp3 as a transcription factor, are subsets of CD4+ T cells. Treg cells play crucial roles in immune tolerance ...

Visualizing the Effects of Sputum on Biofilm Development Using a Chambered Coverglass Model

Biofilms consist of groups of bacteria encased in a self-secreted matrix. They play an important role in industrial contamination as well as in the development and persistence of many health related infections. One of the most well described and studied biofilms in human disease occurs in chronic pulmonary infection of cystic fibrosis patients. When studying biofilms in the context of the host, many factors can impact biofilm formation and development. In order to identify how host factors may affect biofilm formation and development, we used a static chambered coverglass method to grow biofilms in the presence of host-derived factors in the form of sputum supernatants. Bacteria are seeded into chambers and exposed to sputum filtrates. Following 48 hr of growth, biofilms are stained with a commercial biofilm viability kit prior to confocal microscopy and analysis. Following image acquisition, biofilm properties can be assessed using different software platforms. This method allows us to visualize key properties of biofilm growth in presence of different substances including antibiotics.

This protocol describes the visualization of biofilm development following exposure to host-factors using a slide chamber model. This model allows for direct visualization of biofilm development as well as analysis of biofilm parameters using computer software programs.

Visualisierung der Auswirkungen von Sputum auf Biofilm-Entwicklung eines Modells mit Kammerdeckgläser

Biofilms consist of groups of bacteria encased in a self-secreted matrix. They play an important role in industrial contamination as well as in the ...

Optical Screening of Novel Bacteria-specific Probes on Ex Vivo Human Lung Tissue by Confocal Laser Endomicroscopy

Improving the speed and accuracy of bacterial detection is important for patient stratification and to ensure the appropriate use of antimicrobials. To achieve this goal, the development of diagnostic techniques to recognize bacterial presence in real-time at the point-of-care is required. Optical imaging for direct identification of bacteria within the host is an attractive approach. Several attempts at chemical probe design and validation have been investigated, however none have yet been successfully translated into the clinic. Here we describe a method for ex vivo validation of bacteria-specific probes for identification of bacteria within the distal lung, imaged by fibered confocal fluorescence microscopy (FCFM). Our model used ex vivo human lung tissue and a clinically approved confocal laser endomicroscopy (CLE) platform to screen novel bacteria-specific imaging compounds, closely mimicking imaging conditions expected to be encountered with patients. Therefore, screening compounds by this technique provides confidence of potential clinical tractability.

Optical Screening of Novel Bacteria-specific Probes on Ex Vivo Human Lung Tissue by Confocal Laser Endomicroscopy

This technique describes an efficient screening process for evaluating bacteria-specific optical imaging agents within ex vivo human lung tissue, by fibered confocal fluorescence microscopy for the rapid identification of small molecule chemical probe-candidates with translatable potential.

Optische Überprüfung der neuartige Bakterien-spezifischen Sonden auf Ex Vivo menschlichen Lungengewebe durch konfokale Laser Endomikroskopie

Improving the speed and accuracy of bacterial detection is important for patient stratification and to ensure the appropriate use of antimicrobials. To ...