저자는 이 원고에 대한 편집 적 도움을 리 장, 시안 지 리, 아론 힌츠, 클레이튼 홀에게 감사드립니다. 이 분석은 처음에 조지 O'Toole의 실험실에서 개발되었다, 다트머스에서 의학의 가이젤 학교. Mah 박사의 실험실에 있는 연구는 캐나다와 낭포성 섬유증 캐나다의 자연 과학 및 공학 연구 위원회의 보조금에 의해 지원됩니다.

1. MBC-B
<ol><li>
생물막 을 성장 (O'Toole9에서적응).
	<ol>
<li>37°C에서 풍부한 배지에서 16시간 동안 관심 및 돌연변이 균주의 야생형 균주의 배양을 성장시다.</li>
		<li>포화 하룻밤 문화를 1:100을 항생제 내성 분석용 신선한 배지로 희석시. P. aeruginosa에 대 한 표준 매체는 M63 최소 매체 마그네슘 황 산 과 아르기닌으로 보충 (표 1참조). 이 매체는 보다 견고한 바이오필름의 형성을 자극합니다.</li>
		<li>96웰 마이크로티터 접시에 잘 당 희석 100 μl을 추가합니다(표 1참조). 이러한 애술은 일반적으로 각 변형에 대해 삼중에서 수행되기 때문에 각 변형의 24 개의 우물이 있어야합니다.</li>
		<li>37°C에서 24시간 동안 마이크로티터 플레이트를 배양한다.</li>
	</ol>
</li>
	<li>
항생제의 농도 그라데이션에 미리 형성된 생물막을 노출
	<ol>
<li>7 개의 우물에 대한 항생제의 10 배 희석 시리즈를 준비합니다. 예: 항생제 토브라마이신의 경우, 우물의 최종 농도는 0.4, 0.2, 0.1, 0.05, 0.025, 0.0125 및 0.006 mg/ml 5-8이다. 25 mg/ml의 육수에서 4, 2, 1, 0.5, 0.25, 0.125 및 0.06 mg/ml의 10배 희석을 준비하십시오. 얼음 위에 두십시오.</li>
		<li>멀티채널 파이펫을 사용하여 소비된 상체(판자 세포 포함)를 제거합니다(표 1참조).</li>
		<li>모든 우물에 90 μl M63(Mg/Arg)를 추가합니다.</li>
		<li>원하는 최종 농도를 달성하기 위해 각 10x 항생제 농도의 10 μl을 추가합니다. 각 복제 및 변형에 대해 최종 우물에 10 μl 물 (항생제 통제 없음)을 추가하십시오.</li>
		<li>37°C에서 24시간 동안 마이크로티터 플레이트를 배양한다.</li>
	</ol>
</li>
	<li>
미디어를 새로 고침하고 살아있는 세포의 분리를 허용합니다.
	<ol>
<li>멀티채널 파이펫을 사용하여 소비된 상체(판자 세포 포함)를 제거합니다.</li>
		<li>모든 우물에 115 μl M63(Mg/Arg)를 추가합니다.</li>
		<li>37°C에서 24시간 동안 마이크로티터 플레이트를 배양한다.</li>
	</ol>
</li>
	<li>
라이브 셀에 대한 분석.
	<ol>
<li>96웰 마이크로티터 플레이트당 LB 한천 플레이트 2개를 라벨로 지정합니다.</li>
		<li>100% 에탄올에 갈구를 찍어 분젠 버너의 불꽃에 걸쳐 갈구를 전달하여 다중 prong 장치 (표 1참조)를 살균합니다. 반복하다. 갈매기를 약간 식힙니다. 다중prong 장치를 사용하여, 마이크로티터 플레이트의 각 웰에서 LB 천판의 표면으로 판자 배양의 ~3 μl (일반적으로 갈래의 끝에 유지되는 양)을 전송합니다.</li>
		<li>37°C에서 16시간 동안 LB 한천 플레이트를 배양합니다.</li>
		<li>항생제의 최소한의 살균 농도를 식별하여, 눈으로, 세균 성장을 위한 컷오프(도1)를결정한다.</li>
	</ol>
</li>
</ol>2. MBC-P
<ol><li>
세균균 제고
	<ol>
<li>37°C에서 풍부한 배지에서 16시간 동안 관심 및 돌연변이 균주의 야생형 균주의 배양을 성장시다.</li>
		<li>포화 하룻밤 문화를 1:100을 항생제 내성 분석용 신선한 배지로 희석시. P. aeruginosa에 대 한 표준 매체는 M63 최소 매체 마그네슘 황 산 과 아르기닌으로 보충 (표 1참조).</li>
		<li>96웰 마이크로티터 접시에 잘 당 희석 90 μl을 추가합니다(표 1참조). 이러한 애술은 일반적으로 각 변형에 대해 삼중에서 수행되기 때문에 각 변형의 24 개의 우물이 있어야합니다.</li>
	</ol>
</li>
	<li>
항생제의 농도 그라데이션에 판자 세포를 노출
	<ol>
<li>7 개의 우물에 대한 항생제의 10 배 희석 시리즈를 준비합니다. 예: 항생제 토브라마이신의 경우, 우물의 최종 농도는 0.032, 0.016, 0.008, 0.004, 0.002, 0.001 및 0.0005 mg/ml이다. 25 mg/ml의 주식에서 0.32, 0.16, 0.08, 0.04, 0.02, 0.01 및 0.005 mg/ml의 희석을 준비하십시오. 얼음 위에 두십시오.</li>
		<li>원하는 최종 농도를 달성하기 위해 각 10x 항생제 농도의 10 μl을 추가합니다. 각 복제 및 변형에 대해 최종 우물에 10 μl 물 (항생제 통제 없음)을 추가하십시오.</li>
		<li>37°C에서 24시간 동안 마이크로티터 플레이트를 배양한다.</li>
	</ol>
</li>
	<li>
라이브 셀에 대한 분석.
	<ol>
<li>96웰 마이크로티터 플레이트당 LB 한천 플레이트 2개를 라벨로 지정합니다.</li>
		<li>100% 에탄올에 갈구를 찍어 분젠 버너의 불꽃에 걸쳐 갈구를 전달하여 다중 prong 장치 (표 1참조)를 살균합니다. 반복하다. 갈매기를 약간 식힙니다. 다중prong 장치를 사용하여, 마이크로티터 플레이트의 각 웰에서 LB 천판의 표면으로 판자 배양의 ~3 μl (일반적으로 갈래의 끝에 유지되는 양)을 전송합니다.</li>
		<li>37°C에서 16시간 동안 LB 한천 플레이트를 배양합니다.</li>
		<li>항생제의 최소한의 살균 농도를 식별하여, 눈으로, 세균 성장을 위한차단(도 2)을결정한다.</li>
	</ol>
</li>
</ol>

<ol>
	<li>Hoiby, N., Bjarnsholt, T., Givskov, M., Molin, S., Ciofu, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antibiotic+resistance+of+bacterial+biofilms.">Antibiotic resistance of bacterial biofilms.</a> Int. J. Antimicrob. Agents. 35 (4), 322-332 (2010).</li><li>Mah, T. F., O'Toole, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+biofilm+resistance+to+antimicrobial+agents.">Mechanisms of biofilm resistance to antimicrobial agents.</a> Trends Microbiol. 9 (1), 34-39 (2001).</li><li>Mah, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biofilm-specific+antibiotic+resistance.">Biofilm-specific antibiotic resistance.</a> Future Microbiol. 7 (9), 1061-1072 (2012).</li><li>Mah, T. F., Pitts, B., Pellock, B., Walker, G. C., Stewart, P. S., O'Toole, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+genetic+basis+for+Pseudomonas+aeruginosa+biofilm+antibiotic+resistance.">A genetic basis for Pseudomonas aeruginosa biofilm antibiotic resistance.</a> Nature. 426 (6964), 306-310 (2003).</li><li>Zhang, L., Mah, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Involvement+of+a+Novel+Efflux+System+in+Biofilm-Specific+Resistance+to+Antibiotics.">The Involvement of a Novel Efflux System in Biofilm-Specific Resistance to Antibiotics.</a> J. Bacteriol. 190 (13), 4447-4452 (2008).</li><li>Zhang, L., Hinz, A. J., Nadeau, J. P., Mah, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pseudomonas+aeruginosa+tssC1+Links+Type+VI+Secretion+and+Biofilm-specific+Antibiotic+Resistance.">Pseudomonas aeruginosa tssC1 Links Type VI Secretion and Biofilm-specific Antibiotic Resistance.</a> J. Bacteriol. 193 (19), 5510-5513 (2011).</li><li>Beaudoin, T., Zhang, L., Hinz, A. J., Parr, C. J., Mah, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Biofilm-Specific+Antibiotic+Resistance+Gene,+ndvB,+is+Important+for+Expression+of+Ethanol+Oxidation+Genes+in+Pseudomonas+aeruginosa+Biofilms.">The Biofilm-Specific Antibiotic Resistance Gene, ndvB, is Important for Expression of Ethanol Oxidation Genes in Pseudomonas aeruginosa Biofilms.</a> J. Bacteriol. 194 (12), 3128-3136 (2012).</li><li>O'Toole, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microtiter+Dish+Biofilm+Formation+Assay.">Microtiter Dish Biofilm Formation Assay.</a> J. Vis. Exp. (47), e2437 (2011).</li><li>Lewis, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multidrug+tolerance+of+biofilms+and+persister+cells.">Multidrug tolerance of biofilms and persister cells.</a> Curr. Top. Microbiol. Immunol. 322, 107-131 (2008).</li><li>Merritt, J. H., Kadouri, D. E., O'Toole, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growing+and+Analyzing+Static+Biofilms.">Growing and Analyzing Static Biofilms.</a> Curr. Protoc. Microbiol. 1, 1B.1.1-1B.1.17 (2005).</li><li>Ramey, B. E., Parsek, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+1.+Growing+and+analyzing+biofilms+in+fermenters.">Chapter 1. Growing and analyzing biofilms in fermenters.</a> Curr. Protoc. Microbiol. 1, 1B.3.1-1B.3.14 (2005).</li></ol>

저자는 그녀가 경쟁 재정적 이익이 없다고 선언합니다.

판자 세포내 항생 저항성은 세포의 영구적인변화(예를 들어 돌연변이)로 인한 항생제의 최소 억제 농도(MIC)의 증가로 정의된다. 현재까지 확인된 생물막 특이적 저항 또는 내성의 메커니즘은 생물막 내의 야생 형 유전자의 발현의 결과입니다. 따라서, 저항의 고전적인 정의는 생물막에 적용되지 않습니다. 그러나, 정의의 또 다른 세트가 제시되었습니다: 저항 기계장치는 항생제가 그것의 ?...

항생 저항 분석은 처음에 박테리아의 판자 (자유 수영) 문화의 저항을 분석하기 위하여 개발되었습니다. 많은 세균성 감염은 생물막 (표면 부착 된 세포)를 포함하기 때문에, 우리는 생물막 특정 항생제 내성을 분석하는 방법을 개발하는 데 관심이 있었다. 그러나, 대부분의 항생 저항 분석은 생물막의 저항을 측정하기 위해 제대로 적합합니다. 예를 들어, 최소한의 억제 농도(MIC)를 결정하는 것은 판자 세균 배양1의항생제 내성을 결정하기 위한 금본위제이다. 이 분석은 희석 된 판자 문화를 항생제의 희석 시리즈와 혼합하는 것을 수반합니다.  판자 세포의 눈에 보이는 성장을 억제하는 항생제의 농도는 MIC입니다. 이 분석법은 성장 억제에 의존하기 때문에, 정의에 의해, 그것은 미리 자란 생물막에서 세포의 항생제 감도를 검사해야 하는 생물막 배양과 함께 작동할 수 없습니다. 여기에 설명된 MBC-B 분석법은 성장 억제를 측정하는 대신 생물막에 이미 존재하는 세포를 죽이는 항생제의 농도를 결정합니다. 따라서, 이러한 분석법은 확립된 생물막 감염의 항생제 치료를 모방하고 생체 내에서세균성 항생제 내성의 보다 관련성이 있는 관점을 제공하는 것을 목표로 한다.
생물막은 일반적으로 판자 배양보다 항생제 내성이 2-4이기 때문에, 생물막의 항생제 내성을 직접 적으로 플랑크토닉 배양의 항생제 내성을 포함하는 방법을 고안할 필요가 있었다. 따라서 이 방법의 또 다른 목표는 판자 세포와 생물막 세포 사이의 항생 저항 수준을 직접 비교할 수 있다는 것입니다. 여기에 설명된 MBC-P와 MBC-B 의 소는 세포가 비슷한 조건에서 배양되기 때문에 이를 가능하게 합니다. 우리는 생물막 특이적 항생제 저항 5-8에 중요한 몇몇 유전자를 연구하기 위하여 이 방법을 이용했습니다.

<table border="1" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td style="width:160px;">
			1x&#160;M63
			</td>
			<td style="width:160px;">
			
			</td>
			<td style="width:160px;">
			
			</td>
			<td style="width:160px;">
			Prepare as a 5x&#160;M63 stock by dissolving 15g KH2PO4, 35g K2HPO4 and 10g (NH4)2SO4 in 1 L of water. This stock does not need to be autoclaved and can be stored at room temperature.&#160; Dilute 5x&#160;stock 1:5, autoclave, cool, then add the desired components.
			</td>
		</tr>
		<tr>
			<td style="width:160px;">
			KH2PO4
			</td>
			<td style="width:160px;">
			Fisher
			</td>
			<td style="width:160px;">
			P285-500
			</td>
			<td style="width:160px;">
			
			</td>
		</tr>
		<tr>
			<td style="width:160px;">
			K2HPO4
			</td>
			<td style="width:160px;">
			Fisher
			</td>
			<td style="width:160px;">
			P288-500
			</td>
			<td style="width:160px;">
			
			</td>
		</tr>
		<tr>
			<td style="width:160px;">
			(NH4)2SO4
			</td>
			<td style="width:160px;">
			Sigma
			</td>
			<td style="width:160px;">
			A5132
			</td>
			<td style="width:160px;">
			
			</td>
		</tr>
		<tr>
			<td style="width:160px;">
			Magnesium sulfate
			</td>
			<td style="width:160px;">
			Fisher
			</td>
			<td style="width:160px;">
			M63-500
			</td>
			<td style="width:160px;">
			Add to 1 mM final concentration.&#160; Prepare as a 1 M stock in water and autoclave.
			</td>
		</tr>
		<tr>
			<td style="width:160px;">
			Tobramycin
			</td>
			<td style="width:160px;">
			Sigma
			</td>
			<td style="width:160px;">
			
			</td>
			<td style="width:160px;">
			Prepare 50 mg/m&#160;stock. Aliquot and store at -20&#176;C.
			</td>
		</tr>
		<tr>
			<td style="width:160px;">
			Arginine
			</td>
			<td style="width:160px;">
			Sigma
			</td>
			<td style="width:160px;">
			A5131
			</td>
			<td style="width:160px;">
			Add to 0.4% final concentration.&#160; Prepare as a 20% stock in water and filter sterilize.&#160; This alternative carbon/energy source can replace glucose and casamino acids
			</td>
		</tr>
		<tr>
			<td style="width:160px;">
			96-well microtiter plates
			</td>
			<td style="width:160px;">
			Corning
			</td>
			<td style="width:160px;">
			3595
			</td>
			<td style="width:160px;">
			Sterile, flat-bottom, low evaporation
			</td>
		</tr>
		<tr>
			<td style="width:160px;">
			Tranferpette (multichannel pipette)
			</td>
			<td style="width:160px;">
			BrandTech
			</td>
			<td style="width:160px;">
			2703610
			</td>
			<td style="width:160px;">
			8-channel, 20-200 &#956;l
			</td>
		</tr>
		<tr>
			<td style="width:160px;">
			Multiprong device
			</td>
			<td style="width:160px;">
			Dan-Kar
			</td>
			<td style="width:160px;">
			MC48
			</td>
			<td style="width:160px;">
			48 prongs fit into &#189; of a 96-well microtiter plate
			</td>
		</tr>
	</tbody>
</table>

establishing the minimal bactericidal concentration of an antimicrobial agent for planktonic cells (mbc-p) and biofilm cells (mbc-b)

이 프로토콜은 시험관 내에서생물막을 형성할 수 있는 세균균에 대한 플랑크토닉과 생물막 저항을 직접 비교할 수 있게 한다. 박테리아는 96 웰 마이크로티터 플레이트의 우물에 접종됩니다. 판자 분석의 경우, 선택의 항균제의 직렬 희석이 세균 현탁액에 첨가된다. 생물막 분석에서, 한 번 접종, 박테리아는 시간의 설정 된 기간 동안 생물 막을 형성하기 위해 남아있다. 부착되지 않은 세포는 우물에서 제거되고, 미디어는 보충되고 선택의 항균제의 직렬 희석이 첨가된다. 항균제에 노출된 후, 판자 세포는 성장을 위해 분석된다. 생물막 분석의 경우, 매체는 항균제가 결여된 신선한 매체로 리프레시되고 생물막 세포는 회복상태로 남겨집니다. 생물막 세포 생존가능성은 회복 기간 이후에 분석된다. 항균제에 대한 MBC-P는 판자 배양에서 세포를 죽이는 약물의 가장 낮은 농도로 정의된다.  반면, MBC-B는 24시간 동안 항균제의 농도를 높이기 위해 미리 형성된 생물막을 노출시킴으로써 결정된다. MBC-B는 생물막내세포를 죽이는 항균제의 가장 낮은 농도로 정의된다.

MBC-P와 MBC-B 는 PA14 와일드 타입의 감성을 PA14 ∆ndvB와비교하며 진행되었다. 토브라마이신은 항생제로 사용되었다. 단계 1.4.4(도 1)및 단계 2.3.4(도 2)에해당하는 결과가 제시된다. MBC-P와 MBC-B 의 한 미수구는 '∆'에 접종을 했다. MBC-B 프로토콜의 1.0-1.4 단계와 MBC-P 프로토콜의 2.0-2.3 단계를 완료한 후 실행 가능한 세포는 LB 한천판에 도금되었습니다. 토브라마이신...

Watch this Scientific Journal Video about Establishing the Minimal Bactericidal Concentration of an Antimicrobial Agent for Planktonic Cells MBC-P and Biofilm Cells MBC-B at JoVE.com

Establishing the Minimal Bactericidal Concentration of an Antimicrobial Agent for Planktonic Cells MBC-P and Biofilm Cells MBC-B

이 프로토콜은 96웰 마이크로티터 플레이트를 사용하여 체외에서 생물막을 형성할 수 있는 세균균에 대한 플랑크토닉 과 생물막 내성을 직접 비교할 수 있게 한다. 플랑크토닉 또는 생물막 박테리아는 선택의 항균제의 직렬 희석에 노출된다. 생존력은 한천 판의 성장에 의해 분석됩니다.

플랑크토닉 세포(MBC-P) 및 생물막세포(MBC-B)의 항균제 의 최소 박혈 농도 확립

This protocol allows for a direct comparison between planktonic and biofilm resistance for a bacterial strain that can form a biofilm in vitro. Bacteria ...

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JoVE Journal

Immunology and Infection

Establishing the Minimal Bactericidal Concentration of an Antimicrobial Agent for Planktonic Cells (MBC-P) and Biofilm Cells (MBC-B)

19.8K 조회수.  University of Ottawa. 이 프로토콜은 96웰 마이크로티터 플레이트를 사용하여 체외에서 생물막을 형성할 수 있는 세균균에 대한 플랑크토닉 과 생물막 내성을 직접 비교할 수 있게 한다. 플랑크토닉 또는 생물막 박테리아는 선택의 항균제의 직렬 희석에 노출된다. 생존력은 한천 판의 성장에 의해 분석됩니다.

비디오: Establishing the Minimal Bactericidal Concentration of an Antimicrobial Agent for Planktonic Cells MBC-P and Biofilm Cells MBC-B

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).

흐름 세포 녹농균 및 Saccharomyces cerevisiae의의 Biofilm

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

연구

면역학 및 감염병학

In vitro Biofilm Formation in an 8-well Chamber Slide

The chronic nature of many diseases is attributed to the formation of bacterial biofilms which are recalcitrant to traditional antibiotic therapy. Biofilms are community-associated bacteria attached to a surface and encased in a matrix. The role of the extracellular matrix is multifaceted, including facilitating nutrient acquisition, and offers significant protection against environmental stresses (e.g. host immune responses). In an effort to acquire a better understanding as to how the bacteria within a biofilm respond to environmental stresses we have used a protocol wherein we visualize bacterial biofilms which have formed in an 8-well chamber slide. The biofilms were stained with the BacLight Live/Dead stain and examined using a confocal microscope to characterize the relative biofilm size, and structure under varying incubation conditions. Z-stack images were collected via confocal microscopy and analyzed by COMSTAT. This protocol can be used to help elucidate the mechanism and kinetics by which biofilms form, as well as identify components that are important to biofilm structure and stability.

In vitro Biofilm Formation in an 8-well Chamber Slide

This article describes the procedure for the formation and visualization of a bacterial biofilm grown within an 8-well chamber slide

8 잘 회의소 슬라이드에서 체외의 Biofilm 형성에

The chronic nature of many diseases is attributed to the formation of bacterial biofilms which are recalcitrant to traditional antibiotic therapy. ...

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.

에 셀 운명을 따라<em&gt; E. 대장균</em&gt; 파지 람다에 의해 감염 후

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

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

The study of polymicrobial interactions across the taxonomic kingdoms that include fungi, bacteria and virus have not been previously examined with respect to how viral members of the microbiome affect subsequent microbe interactions with these virus-infected host cells. The co-habitation of virus with bacteria and fungi is principally present on the mucosal surfaces of the oral cavity and genital tract. Mucosal cells, particularly those with persistent chronic or persistent latent viral infections, could have a significant impact on members of the microbiome through virus alteration in number and type of receptors expressed. Modification in host cell membrane architecture would result in altered ability of subsequent members of the normal flora and opportunistic pathogens to initiate the first step in biofilm formation, i.e., adherence. This study describes a method for quantitation and visual examination of HSV&#39;s effect on the initiation of biofilm formation (adherence) of S. aureus and C. albicans.

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.

박테리아와 균류에 의해 바이러스에 감염된 세포에 바이오 필름 개시의 결정

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

Development and Validation of an Ultrasensitive Single Molecule Array Digital Enzyme-linked Immunosorbent Assay for Human Interferon-&#945;

The main aim of this protocol is to describe the development and validation of an interferon (IFN)-&#945; single molecule array digital Enzyme-Linked ImmunoSorbent Assay (ELISA) assay. This system enables the quantification of human IFN-&#945; protein with unprecedented sensitivity, and with no cross-reactivity for other species of IFN.
The first key step of the protocol is the choice of the antibody pair, followed by the conjugation of the capture antibody to paramagnetic beads, and biotinylation of the detection antibody. Following this step, different parameters such as assay configuration, detector antibody concentration, and buffer composition can be modified until optimum sensitivity is achieved. Finally, specificity and reproducibility of the method are assessed to ensure confidence in the results. Here, we developed an IFN-&#945; single molecule array assay with a limit of detection of 0.69 fg/mL using high-affinity autoantibodies isolated from patients with biallelic mutations in the autoimmune regulator (AIRE) protein causing autoimmune polyendocrinopathy syndrome type 1/autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APS1/APECED). Importantly, these antibodies enabled detection of all 13 IFN-&#945; subtypes.
This new methodology allows the detection and quantification of IFN-&#945; protein in human biological samples at attomolar concentrations for the first time. Such a tool will be highly useful in monitoring the levels of this cytokine in human health and disease states, most particularly infection, autoimmunity, and autoinflammation.

Development and Validation of an Ultrasensitive Single Molecule Array Digital Enzyme-linked Immunosorbent Assay for Human Interferon-&amp;#945;

Here we present a protocol to describe the development and validation of a single molecule array digital ELISA assay, which enables the ultra-sensitive detection of all IFN-&#945; subtypes in human samples.

개발 및 검증 磁 단일 분자의 배열 디지털 효소 연결 된 Immunosorbent 분석 결과 인간 인터페론-α에 대 한

The main aim of this protocol is to describe the development and validation of an interferon (IFN)-&#945; single molecule array digital Enzyme-Linked ...

Multicolor Flow Cytometry-based Quantification of Mitochondria and Lysosomes in T Cells

T cells utilize different metabolic programs to match their functional needs during differentiation and proliferation. Mitochondria are crucial cellular components responsible for supplying cell energy; however, excess mitochondria also produce reactive oxygen species (ROS) that could cause cell death. Therefore, the number of mitochondria must constantly be adjusted to fit the needs of the cells. This dynamic regulation is achieved in part through the function of lysosomes that remove surplus/damaged organelles and macromolecules. Hence, cellular mitochondrial and lysosomal contents are key indicators to evaluate the metabolic adjustment of cells. With the development of probes for organelles, well-characterized lysosome or mitochondria-specific dyes have become available in various formats to label cellular lysosomes and mitochondria. Multicolor flow cytometry is a common tool to profile cell phenotypes, and has the capability to be integrated with other assays. Here, we present a detailed protocol of how to combine organelle-specific dyes with surface markers staining to measure the amount of lysosomes and mitochondria in different T cell populations on a flow cytometer.

This article illustrates a powerful method to quantify mitochondria or lysosomes in living cells. The combination of lysosome- or mitochondria-specific dyes with fluorescently conjugated antibodies against surface markers allows the quantification of these organelles in mixed cell populations, like primary cells harvested from tissue samples, by using multicolor flow cytometry.

미토 콘 드리 아와 T 세포에서는 리소좀의 다 색 흐름 Cytometry 기반 정량화

T cells utilize different metabolic programs to match their functional needs during differentiation and proliferation. Mitochondria are crucial cellular ...

A High-throughput Shigella-specific Bactericidal Assay

Serum bactericidal assays (SBAs) measure the functional activity of antibodies and have been used for many decades. SBAs directly measure antibody killing activity by assessing the ability of antibodies in serum to bind to bacteria and activate complement. This complement activation results in the lysis and killing of the target bacteria. These assays are valuable because they go beyond quantifying antibody production to elucidate the biological functions that these antibodies have, allowing researchers to study the role that antibodies may play in preventing infection. SBAs have been used to study immune responses for many human pathogens, but there is no widely accepted methodology for Shigella at present. Historically, SBAs have been very labor-intensive, requiring many time-consuming steps to accurately quantify surviving bacteria. This protocol describes a simple, robust, and high-throughput assay that measures functional antibodies specific for Shigella in serum in vitro. The method described here offers many advantages over traditional SBAs, including the use of frozen bacterial stocks, 96 well assay plates, a micro-culture system, and automated colony-counting. All of these modifications make this assay less labor-intensive and more high-throughput. This protocol is simpler and faster to perform than traditional SBAs while still using simple technologies and readily available reagents. The protocol has been successfully applied in multiple independent laboratories and the assay is robust and reproducible. The assay can be used to assess immune responses in pre-clinical as well as clinical studies. Quantifying shigellacidal antibody titers both before and after antigen exposure (either by immunization or infection) allows for a broader understanding of how functional antibody responses are generated and their contribution to protective immunity. The development of this standardized, well-characterized assay may greatly facilitate Shigella vaccine design.

A High-throughput Shigella-specific Bactericidal Assay

Here we present a protocol to measure Shigellacidal activity of antibodies in serum. Serum is mixed with bacteria and exogenous complement, incubated, and the reaction mixture is plated on agar plates. Viable bacteria form colonies which are counted, using an automated colony enumerator, and used to determine the bactericidal titer.

높은 처리량 Shigella-특정 살 균 시험

Serum bactericidal assays (SBAs) measure the functional activity of antibodies and have been used for many decades. SBAs directly measure antibody killing ...

Production and Characterization of Human Macrophages from Pluripotent Stem Cells

Macrophages are present in most vertebrate tissues and comprise widely dispersed and heterogeneous cell populations with different functions. They are key players in health and disease, acting as phagocytes during immune defense and mediating trophic, maintenance, and repair functions. Although it has been possible to study some of the molecular processes involved in human macrophage function, it has proved difficult to apply genetic engineering techniques to primary human macrophages. This has significantly hampered our ability to interrogate the complex genetic pathways involved in macrophage biology and to generate models for specific disease states. An off-the-shelf source of human macrophages that is amenable to the vast arsenal of genetic manipulation techniques would, therefore, provide a valuable tool in this field. We present an optimized protocol that allows for the generation of macrophages from human induced pluripotent stem cells (iPSCs) in vitro. These iPSC-derived macrophages (iPSC-DMs) express human macrophage cell surface markers, including CD45, 25F9, CD163, and CD169, and our live-cell imaging functional assay demonstrates that they exhibit robust phagocytic activity. Cultured iPSC-DMs can be activated to different&#160;macrophage states that display altered gene expression and phagocytic activity by the addition of LPS and IFNg, IL4, or IL10. Thus, this system provides a platform to generate human macrophages carrying genetic alterations that model specific human disease and a source of cells for drug screening or cell therapy to treat these diseases.

This protocol describes the robust generation of macrophages from human induced pluripotent stem cells, and methods for their subsequent characterization. Cell surface marker expression, gene expression, and functional assays are used to assess the phenotype and function of these iPSC-derived macrophages.

다능성 줄기 세포에서 인간 대식세포의 생산 및 특성화

Macrophages are present in most vertebrate tissues and comprise widely dispersed and heterogeneous cell populations with different functions. They are key ...

Establishing a Porcine Ex Vivo Cornea Model for Studying Drug Treatments against Bacterial Keratitis

When developing novel antimicrobials, the success of animal trials is dependent on accurate extrapolation of antimicrobial efficacy from in vitro tests to animal infections in vivo. The existing in vitro tests typically overestimate antimicrobial efficacy as the presence of host tissue as a diffusion barrier is not accounted for. To overcome this bottleneck, we have developed an ex vivo porcine corneal model of bacterial keratitis using Pseudomonas aeruginosa as a prototypic organism. This article describes the preparation of the porcine cornea and protocol for establishment of the infection. Bespoke glass molds enable straightforward setup of the cornea for infection studies. The model mimics in vivo infection as bacterial proliferation is dependent on the ability of the bacterium to damage corneal tissue. Establishment of infection is verified as an increase in the number of colony forming units assessed via viable plate counts. The results demonstrate that infection can be established in a highly reproducible fashion in the ex vivo corneas using the method described here. The model can be extended in the future to mimic keratitis caused by microorganisms other than P. aeruginosa. The ultimate aim of the model is to investigate the effect of antimicrobial chemotherapy on the progress of bacterial infection in a scenario more representative of in vivo infections. In so doing, the model described here will reduce the use of animals for testing, improve success rates in clinical trials and ultimately enable rapid translation of novel antimicrobials to the clinic.

This article describes a step-by-step protocol to set up an ex vivo porcine model of bacterial keratitis. Pseudomonas aeruginosa is used as a prototypic organism. This innovative model mimics in vivo infection as bacterial proliferation is dependent on the ability of the bacterium to damage corneal tissue.

세균성 각막염에 대하여 약 처리를 공부하기 위한 돼지 Ex Vivo Cornea 모형 을 설치합니다

When developing novel antimicrobials, the success of animal trials is dependent on accurate extrapolation of antimicrobial efficacy from in vitro tests to ...

Quantifying the Effects of Antimicrobials on In vitro Biofilm Architecture using COMSTAT Software

Biofilms are aggregates of microorganisms that rely on a self-produced matrix of extracellular polymeric substance for protection and structural integrity. The nosocomial pathogen, Pseudomonas aeruginosa, is known to adopt a biofilm mode of growth, causing chronic pulmonary infection in patients with cystic fibrosis (CF). The computer program, COMSTAT, is a useful tool for quantifying antimicrobial-induced changes in P. aeruginosa biofilm architecture by extracting data from three-dimensional confocal images. However, standardized operation of the software is less commonly addressed, which is important for optimal reporting of biofilm behavior and cross-center comparison. Thus, the aim of this protocol is to provide a simple and reproducible framework for quantifying in vitro biofilm structures under varying antimicrobial conditions via COMSTAT. The technique is modeled using a CF P. aeruginosa isolate, grown in the form of biofilm replicates, and exposed to tobramycin and the anti-Psl monoclonal antibody, Psl0096. The step-by-step approach aims to reduce user ambiguity and minimize the chance of overlooking crucial image-processing steps. Specifically, the protocol emphasizes the elimination of subjective variations associated with the manual operation of COMSTAT, including image segmentation and the selection of appropriate quantitative analysis functions. Although this method requires users to spend additional time processing confocal images prior to running COMSTAT, it helps minimize misrepresented biofilm heterogenicity in automated outputs.

Quantifying the Effects of Antimicrobials on In vitro Biofilm Architecture using COMSTAT Software

Antimicrobial-induced changes to Pseudomonas aeruginosa biofilm architecture differ among clinical isolates cultured from patients with cystic fibrosis and chronic pulmonary infection. Following confocal microscopy, COMSTAT software can be utilized to quantify variations in biofilm architecture (e.g., surface area, thickness, biomass) for individual isolates to assess the efficacy of anti-infective agents.