Name: detecting cortex fragments during bacterial spore germination
Uploaded: 2016-06-25T13:00:00
Description: Watch this Scientific Journal Video about Detecting Cortex Fragments During Bacterial Spore Germination at JoVE.com

O Projeto descrito é suportado pelo Prêmio Número 5R01AI116895 do Instituto Nacional de Alergia e Doenças Infecciosas. O conteúdo é da exclusiva responsabilidade dos autores e não representam necessariamente as opiniões oficiais do Instituto Nacional de Alergia e Doenças Infecciosas ou o National Institutes of Health.

1. As amostras de Geração <ol><li> Calor ativar C. difficile esporos a 65 ° C durante 30 min e armazenar em gelo. Nota: C. esporos difficile pode ser produzida e purificada tal como descrito anteriormente 7,9,10. </li><li> Preparar a solução de germinação a X + 1 ml onde X é o número de amostras a serem tomadas durante o ensaio. Nota: A solução de germinação é específico para as espécies de bactérias esporos sendo estudado. Para ensaiar C. diffic...

<ol>
	<li>Al-Hinai, M. A., Jones, S. W., Papoutsakis, E. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Clostridium+sporulation+programs:+diversity+and+preservation+of+endospore+differentiation.">The Clostridium sporulation programs: diversity and preservation of endospore differentiation.</a> Microbiol Mol Biol Rev. 79, 19-37 (2015).</li><li>Setlow, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Germination+of+spores+of+Bacillus+species:+what+we+know+and+do+not+know.">Germination of spores of Bacillus species: what we know and do not know.</a> J Bacteriol. 196, 1297-1305 (2014).</li><li>Tan, I. S., Ramamurthi, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spore+formation+in+Bacillus+subtilis.">Spore formation in Bacillus subtilis.</a> Environ Microbiol Rep. 6, 212-225 (2014).</li><li>Fimlaid, K. A., Shen, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diverse+mechanisms+regulate+sporulation+sigma+factor+activity+in+the+Firmicutes.">Diverse mechanisms regulate sporulation sigma factor activity in the Firmicutes.</a> Curr Opin Microbiol. 24, 88-95 (2015).</li><li>Popham, D. L., Helin, J., Costello, C. E., Setlow, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+the+peptidoglycan+structure+of+Bacillus+subtilis+endospores.">Analysis of the peptidoglycan structure of Bacillus subtilis endospores.</a> J Bacteriol. 178, 6451-6458 (1996).</li><li>Atrih, A., Zollner, P., Allmaier, G., Foster, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+analysis+of+Bacillus+subtilis+168+endospore+peptidoglycan+and+its+role+during+differentiation.">Structural analysis of Bacillus subtilis 168 endospore peptidoglycan and its role during differentiation.</a> J Bacteriol. 178, 6173-6183 (1996).</li><li>Sorg, J. A., Sonenshein, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bile+salts+and+glycine+as+cogerminants+for+Clostridium+difficile+spores.">Bile salts and glycine as cogerminants for Clostridium difficile spores.</a> J. Bacteriol. 190, 2505-2512 (2008).</li><li>Paredes-Sabja, D., Shen, A., Sorg, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clostridium+difficile+spore+biology:+sporulation,+germination,+and+spore+structural+proteins.">Clostridium difficile spore biology: sporulation, germination, and spore structural proteins.</a> Trends Microbiol. 22 (7), (2014).</li><li>Francis, M. B., Allen, C. A., Sorg, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spore+cortex+hydrolysis+precedes+DPA+release+during+Clostridium+difficile+spore+germination.">Spore cortex hydrolysis precedes DPA release during Clostridium difficile spore germination.</a> J Bacteriol. 197 (14), (2015).</li><li>Francis, M. B., Allen, C. A., Shrestha, R., Sorg, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bile+acid+recognition+by+the+Clostridium+difficile+Germinant+Receptor,+CspC,+is+important+for+establishing+infection.">Bile acid recognition by the Clostridium difficile Germinant Receptor, CspC, is important for establishing infection.</a> PLoS Pathog. 9, e1003356 (2013).</li><li>Moir, A., Smith, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Genetics+of+bacterial+spore+germination.">The Genetics of bacterial spore germination.</a> Annu. Rev. Microbiol. 44, 531-553 (1990).</li><li>Zhang, P., Kong, L., Wang, G., Setlow, P., Li, Y. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combination+of+Raman+tweezers+and+quantitative+differential+interference+contrast+microscopy+for+measurement+of+dynamics+and+heterogeneity+during+the+germination+of+individual+bacterial+spores.">Combination of Raman tweezers and quantitative differential interference contrast microscopy for measurement of dynamics and heterogeneity during the germination of individual bacterial spores.</a> Journal of biomedical optics. 15, 056010 (2010).</li><li>Ghuysen, J. -. M., Tipper, D. J., Strominger, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enzymes+that+degrade+bacterial+cell+walls.">Enzymes that degrade bacterial cell walls.</a> Methods Enzymol. 8, 685-699 (1966).</li><li>Park, J. T., Johnson, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+submicrodetermination+of+glucose.">A submicrodetermination of glucose.</a> J Biol Chem. 181, 149-151 (1949).</li><li>Thompson, J. S., Shockman, G. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+modification+of+the+Park+and+Johnson+reducing+sugar+determination+suitable+for+the+assay+of+insoluble+materials:+its+application+to+bacterial+cell+walls.">A modification of the Park and Johnson reducing sugar determination suitable for the assay of insoluble materials: its application to bacterial cell walls.</a> Anal Biochem. 22, 260-268 (1968).</li><li>Paredes-Sabja, D., Setlow, P., Sarker, 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=SleC+is+essential+for+cortex+peptidoglycan+hydrolysis+during+germination+of+spores+of+the+pathogenic+bacterium+Clostridium+perfringens.">SleC is essential for cortex peptidoglycan hydrolysis during germination of spores of the pathogenic bacterium Clostridium perfringens.</a> J Bacteriol. 191, 2711-2720 (2009).</li><li>Paredes-Sabja, D., Sarker, 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=Effect+of+the+cortex-lytic+enzyme+SleC+from+non-food-borne+Clostridium+perfringens+on+the+germination+properties+of+SleC-lacking+spores+of+a+food+poisoning+isolate.">Effect of the cortex-lytic enzyme SleC from non-food-borne Clostridium perfringens on the germination properties of SleC-lacking spores of a food poisoning isolate.</a> Can J Microbiol. 56, 952-958 (2010).</li><li>Hindle, A. A., Hall, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dipicolinic+acid+(DPA)+assay+revisited+and+appraised+for+spore+detection.">Dipicolinic acid (DPA) assay revisited and appraised for spore detection.</a> The Analyst. 124, 1599-1604 (1999).</li><li>Kort, R., 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=Assessment+of+heat+resistance+of+bacterial+spores+from+food+product+isolates+by+fluorescence+monitoring+of+dipicolinic+acid+release.">Assessment of heat resistance of bacterial spores from food product isolates by fluorescence monitoring of dipicolinic acid release.</a> Appl Environ Microbiol. 71, 3556-3564 (2005).</li><li>Elson, L. A., Morgan, W. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+colorimetric+method+for+the+determination+of+glucosamine+and+chondrosamine.">A colorimetric method for the determination of glucosamine and chondrosamine.</a> The Biochemical journal. 27, 1824-1828 (1933).</li><li>Ramirez, N., Abel-Santos, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Requirements+for+germination+of+Clostridium+sordellii+spores+in+vitro.">Requirements for germination of Clostridium sordellii spores in vitro.</a> J. Bacteriol. 192, 418-425 (2010).</li><li>Akoachere, 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=Indentification+of+an+in+vivo+inhibitor+of+Bacillus+anthracis+spore+germination.">Indentification of an in vivo inhibitor of Bacillus anthracis spore germination.</a> J. Biol. Chem. 282, 12112-12118 (2007).</li><li>Duncan, C. L., Strong, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+medium+for+sporulation+of+Clostridium+perfringens.">Improved medium for sporulation of Clostridium perfringens.</a> Appl Microbiol. 16, 82-89 (1968).</li><li>Heffron, J. D., Lambert, E. A., Sherry, N., Popham, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contributions+of+four+cortex+lytic+enzymes+to+germination+of+Bacillus+anthracis+spores.">Contributions of four cortex lytic enzymes to germination of Bacillus anthracis spores.</a> J Bacteriol. 192, 763-770 (2010).</li><li>Meador-Parton, J., Popham, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+analysis+of+Bacillus+subtilis+spore+peptidoglycan+during+sporulation.">Structural analysis of Bacillus subtilis spore peptidoglycan during sporulation.</a> J Bacteriol. 182, 4491-4499 (2000).</li><li>Lambert, E. A., Popham, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Bacillus+anthracis+SleL+(YaaH)+protein+is+an+N-acetylglucosaminidase+involved+in+spore+cortex+depolymerization.">The Bacillus anthracis SleL (YaaH) protein is an N-acetylglucosaminidase involved in spore cortex depolymerization.</a> J Bacteriol. 190, 7601-7607 (2008).</li><li>Wang, S., Shen, A., Setlow, P., Li, Y. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+the+Dynamic+Germination+of+Individual+Clostridium+difficile+Spores+Using+Raman+Spectroscopy+and+Differential+Interference+Contrast+Microscopy.">Characterization of the Dynamic Germination of Individual Clostridium difficile Spores Using Raman Spectroscopy and Differential Interference Contrast Microscopy.</a> J Bacteriol. 197, 2361-2373 (2015).</li></ol>

Após estimulação, os esporos submetidos ao processo de germinação perder as suas propriedades de resistência, sem a necessidade de síntese macromolecular. Quando a germinação de esporos é acionado, o núcleo de esporos libera DPA em troca de água 2. Devido ao elevado teor de DPA do esporo dormente, o núcleo é de esporos sob intensa pressão osmótica e o peptidoglicano especializado, córtex, ajuda a impedir que o núcleo de inchaço, agindo, presumivelmente, como uma barreira para a expansão <s...

Endospores são metabolicamente formas latentes de bactérias que permitem que as bactérias para persistir em ambientes desfavoráveis. Em muitas bactérias formadoras de esporos, a formação de esporos é induzida pela privação de nutrientes, mas este processo pode ser controlada por alterações de pH, exposição ao oxigénio ou outros stresses 1. Embora em sua forma de esporos metabolicamente dormente, as bactérias resistir à radiação UV, a dessecação, temperaturas mais elevadas e que congela 2. A maior parte do conhecimento sobre o processo de esporulação vem de estudos no organismo modelo, Bacillus subtilis. O processo de esporulação começa com a replicação do ADN e a formação de um filamento de 3,4 axial. Um septo assimétrica, em seguida, divide a célula em dois compartimentos de tamanho desigual. O compartimento maior, a célula mãe, engolfa o compartimento mais pequeno, o forespore. Tanto a célula mãe e forespore coordenar a expressão do gene para amadurecer o esporo e a célula mãe, eventualmente, lisa, liberando o Dormant de esporos para o ambiente circundante um. A estrutura e a composição de esporos é conservada entre várias espécies bacterianas. O núcleo de esporos tem um teor de água inferior a célula vegetativa e é rica em ácido dipicolínico (DPA) 1,2. Durante a formação de esporos, DPA é bombeado para dentro do núcleo de esporos em troca de água. Em torno do núcleo é uma membrana de esporos interior, onde, na maioria das bactérias formadoras de esporos, os receptores que reconhecem as pequenas moléculas que estimulam a germinação (germinants) estão localizados a 2. Localizado no exterior membrana interna do esporo é uma camada de peptidoglicano da parede celular. Uma camada de peptidoglicano especializado (córtex) rodeia o peptidoglicano da parede celular e é composta de muitos dos mesmos componentes como peptidoglicano da parede celular [alternando N-acetilglucosamina (NAG) e ácido N-acetilmurâmico (NAM)]. No entanto, aproximadamente 50% dos resíduos de NAM no córtex foram convertidos para murâmico-δ-lactama 5,6 </s-se&gt;. Durante a germinação de esporos, estes resíduos murâmico-δ-lactâmicos são reconhecidos pelos esporos do córtex enzimas líticas (SCLEs), permitindo assim que o córtex para ser degradada (um processo essencial para completar a germinação) mas não a parede celular. Rodeando o córtex é uma membrana exterior e várias camadas de proteínas de revestimento 2. Controlando o processo de germinação é criticamente importante para as bactérias formadoras de esporos. A germinação é iniciada quando os receptores germinativa interagir com seus respectivos germinants 2. Em muitas bactérias formadoras de esporos, estes são germinants amino ácidos, açúcares, nucleótidos, iões, ou combinações destes dois. C. difficile germinação de esporos é iniciada por meio de combinações de certos ácidos biliares, [por exemplo, ácido taurocólico (TA)] e aminoácidos (por exemplo, glicina) 7-10. Embora existam diferenças entre o C. via de germinação difficile e as vias estudadas em outra forma de esporobactérias, tais como B. subtilis, comum a todos é a exigência absoluta para degradar o córtex esporos para permitir que uma célula vegetativa a crescer a partir do esporos germinados 2,8. Córtex degradação pode ser conseguida pela SCLEs CwlJ / SleB (como encontrado em B. subtilis) ou SLEC (como encontrado em muitos Clostridia). hidrólise córtex reduz a restrição na parede da célula e esporo. Isto permite uma re-hidratação completa do núcleo, um passo necessário para a reactivação muitas das proteínas necessárias para o metabolismo celular 2. Quando esporos germinam, as mudanças de esporos a partir de um estado dormente de fase brilhante para um estado de fase-escuro e este processo pode ser medido por uma alteração na densidade óptica (DO) a 600 nm 11. Um relatório anterior sugere que grande parte dessa mudança de OD é devido à liberação da DPA do esporo 12. Durante a nossa recente estudo, buscou-se comparar o tempo de C. difficile germinação de esporos e acompanhou olançamento do DPA e córtex fragmentos 9. Para este estudo foi fundamental para monitorar o lançamento de fragmentos de córtex, quando começaram a ser lançado pela germinação de esporos. O ensaio colorimétrico aqui utilizado baseou-se num método para a detecção de açúcares com extremidades redutoras desenvolvido Ghuysen et ai. 13. Porque os outros têm descrito protocolos para a detecção de açúcares redutores 14 ou modificou os protocolos 15, a literatura sobre este assunto pode ser confuso. Aqui, nós detalhe um método passo-a-passo para a detecção colorimétrica de açúcares redutores libertados de germinação C. esporos difficile. Embora este estudo utiliza C. esporos difficile, os açúcares redutores libertados durante a germinação de esporos a partir de outras bactérias formadoras de esporos são capazes de serem detectadas com este protocolo 9,16,17.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>2.0 mL screw cap tube</td>
			<td>USA scientific</td>
			<td>1420-3700</td>
			<td></td>
		</tr>
		<tr>
			<td>p1000 eppendorf pippet</td>
			<td>Eppendorf</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>p200 eppendorf pippet</td>
			<td>Eppendorf</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>p20 eppendorf pippet</td>
			<td>Eppendorf</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>100-1250uL pipet tips</td>
			<td>VWR</td>
			<td>89079-486</td>
			<td></td>
		</tr>
		<tr>
			<td>1-200uL pipet tips</td>
			<td>VWR</td>
			<td>89079-458</td>
			<td></td>
		</tr>
		<tr>
			<td>N-acetyl-D-glucosamine</td>
			<td>Sigma</td>
			<td>A3286-25G</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochloric Acid - 10N</td>
			<td>BDH-Aristar</td>
			<td>BDH3032-3.8LP</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetic Anhydride</td>
			<td>Alfa Aesar</td>
			<td>L04295</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Bicarbonate</td>
			<td>BDH</td>
			<td>BDH0280-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium Tetraborate tetrahydrate</td>
			<td>Alfa Aesar</td>
			<td>39435</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Hydroxide</td>
			<td>BDH</td>
			<td>BDH8019-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>4-(Dimethylamino)benzaldehyde</td>
			<td>Sigma</td>
			<td>156477-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Saturated Phenol</td>
			<td>Fisher</td>
			<td>BP1750-400</td>
			<td></td>
		</tr>
		<tr>
			<td>2-Mercaptoethanol</td>
			<td>Aldrich</td>
			<td>M6250-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>SpectraMax M3</td>
			<td colspan="2">Molecular Devices</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetic Acid, Glacial</td>
			<td>BDH</td>
			<td>BDH3098-3.8LP</td>
			<td></td>
		</tr>
		<tr>
			<td>Heated, Circulating Water Bath</td>
			<td>VWR Scientific</td>
			<td>Model 1136</td>
			<td></td>
		</tr>
		<tr>
			<td>Microtest 96</td>
			<td>Falcon</td>
			<td>353072</td>
			<td>96 well clear tissue culture plates</td>
		</tr>
		<tr>
			<td>Culture tubes</td>
			<td>VWR</td>
			<td>89000-506</td>
			<td></td>
		</tr>
		<tr>
			<td>Lyophilizer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Heat Blocks</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vortex Machine</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

detecting cortex fragments during bacterial spore germination

The process of endospore germination in Clostridium difficile, and other Clostridia, increasingly is being found to differ from the model spore-forming bacterium, Bacillus subtilis. Germination is triggered by small molecule germinants and occurs without the need for macromolecular synthesis. Though differences exist between the mechanisms of spore germination in species of Bacillus and Clostridium, a common requirement is the hydrolysis of the peptidoglycan-like cortex which allows the spore core to swell and rehydrate. After rehydration, metabolism can begin and this, eventually, leads to outgrowth of a vegetative cell. The detection of hydrolyzed cortex fragments during spore germination can be difficult and the modifications to the previously described assays can be confusing or difficult to reproduce. Thus, based on our recent report using this assay, we detail a step-by-step protocol for the colorimetric detection of cortex fragments during bacterial spore germination.

A Tabela 1 mostra os resultados típicos usando padrões de NAG. Os dados são utilizados para gerar uma curva padrão. A Tabela 2 mostra os resultados típicos de um ensaio de germinação de germinação em tampão suplementado com 100 mM de glicina e TA 10 mM (condições de promoção da germinação) ou de glicina 100 mM apenas (condições não-germinação). Na ausência de TA, C. difficile esporos germinam e não há pouca alteração na...

Watch this Scientific Journal Video about Detecting Cortex Fragments During Bacterial Spore Germination at JoVE.com

Detecting Cortex Fragments During Bacterial Spore Germination

Herein, we describe a colorimetric assay to detect the presence of reducing sugars during bacterial spore germination.

Detecção de Cortex Fragmentos Durante bacteriana germinação de esporos

The process of endospore germination in Clostridium difficile, and other Clostridia, increasingly is being found to differ from the model spore-forming ...

The overall goal of this step-by-step protocol is to quantify the abundance of cortex fragments or reducing sugars during bacterial spore germination. This method will detail the steps required to detect the presence of cortex fragments or reducing sugars during spore germination. The main advantage of this technique is most laboratories have the reagents and equipment necessary to successfully complete the protocol.Begin this procedure by placing a tube of Clostridium difficile spores in a heating block and incubating it 65 degrees Celsius for 30 minutes. After the incubation, place the tube on ice. The germination solution is specific to the species of bacterial spore being studied.For assaying C.difficile spore germination, we use a solution of 10 millimolar Tris at pH 7.5 with 150 millimolar of sodium chloride, 100 millimolar glycine, and 10 millimolar taurocholic acid in deionized water. Prepare one milliliter of germination solution per sample plus an additional one milliliter. Before beginning the assay, transfer one milliliter of the germination solution to a microcentrifuge tube and set it aside.This will serve as a blank for cortex fragment detection. Next, to the germination solution, add spores to an OD600 of about 3.0 and briefly vortex. This amount of spores works well for moderating cortex fragment release during C.difficile spore germination.Immediately after adding the spores, remove a 1.2 milliliter sample to a new microcentrifuge tube and put it into the centrifuge. Then centrifuge at room temperature for one minute at 14, 000 times G.This is the zero time point. After the spin, transfer one milliliter of the supernatant to a fresh two-milliliter screw-cap tube and freeze it at negative 80 degrees Celsius.Repeat the process of taking aliquots, spinning down, and freezing at regular intervals until the sample has been collected for each time point. Because of time required for centrifugation and sampling, time points of less than two minutes are not possible during this procedure, so these samples are taken once every two minutes for 14 minutes. While preparing the cortex samples, should dipicolinic acid need to be monitored, remove a separate 100 microliter sample and dispense in a microcentrifuge tube on ice.Also prepare samples for generating a standard curve with the following amounts of N-acetylglucosamine. Zero, 12.5, 25, 50, 100, 250, 500, and 5, 000 nanomoles in germination solution. After a sample has been collected for each time point, remove the samples from the freezer and lyophilize them along with the blank and the standard curve samples.Then store all of the samples at negative 80 degrees Celsius until use. On the day of the assay, resuspend the lyophilized samples, including the controls and standard curve samples, in 120 microliters of hydrochloric acid with phenol and beta-mercaptoethanol. Next, transfer all of the resuspended samples to fresh two-milliliter screw cap tubes.Then incubate them in a recirculating water bath at 95 degrees Celsius for four hours. After the incubation, place the samples on ice until they are cool. Then add 120 microliters of three molar sodium hydroxide to neutralize them.Next, add 80 microliters of a saturated sodium bicarbonate solution and 80 microliters of a 5%acetic anhydride solution to each sample and vortex it. Then incubate the samples at room temperature for 10 minutes. Following the incubation, transfer the samples back to the 95 degree Celsius water bath for exactly three minutes.Note that this step is time sensitive and longer times can affect downstream signal development. Remove the samples from the water bath and cool them on ice. Add 400 microliters of 6.54%potassium tetraborate tetrahydrate to each tube and vortex.Incubate the samples in a recirculating water bath at 95 degrees Celsius for exactly seven minutes. This step is also time sensitive. Remove the samples and place them on ice for five minutes.While the samples are on ice, prepare the color reagent. Dissolve 0.320 grams of DMAB in 1.9 milliliters of glacial acetic acid. Note that this reagent is time, temperature, and light sensitive and should not be made in advance.After the DMAB completely dissolves, add 100 microliters of 10 normal hydrochloric acid and vortex the sample. Then add five milliliters of glacial acetic acid and vortex again. For the colorimetric reaction, transfer 100 microliters of each cooled cortex or control sample to a new 1.5 milliliter microcentrifuge tube.Add 700 microliters of the freshly prepared color solution to each sample. Immediately transfer the samples to a 37 degree Celsius water bath and incubate the samples for exactly 20 minutes. After the incubation, transfer 200 microliters of each sample to a clear 96-well plate.The samples should be yellow in color to begin with but will shift to purple if reducing sugar, which indicates the presence of cortex, is present. Here, many of the samples do not show a visible purple color. However, the 250, 500, and 5, 000 nanomole samples appear visually different from the negative control zero nanomole.Using a plate reader, determine the absorbance at 585 nanometers. When measured in an OD of 585 nanometers, the signal generated from the standard samples best fits a linear regression. This table shows typical results using N-acetylglucosamine standards.These data were then used to generate the standard curve shown here. A germination assay was performed under germination promoting conditions with germination buffer supplemented with 100 millimolar glycine and 10 millimolar taurocholic acid. In non-germinating conditions, 100 millimolar glycine only.In the absence of taurocholic acid, C.Difficile spores do not germinate, and there is little change in the presence of cortex fragments in the solution. However, in the presence of both taurocholic acid and glycine, C.difficile spores germinate and release cortex fragments into the solution. This is absorbed as an increase in the OD585 over time of the reacted samples.The quantity of cortex fragments released during this assay was calculated using a standard curve. As can be seen here in this assay, most of the cortex was hydrolyzed or released by 15 minutes post-germinant exposure. This suggests that most of the spores have germinated in this time frame.After watching this video, you should have a good understanding of how to detect cortex fragments or reducing sugars in a germination solution during bacterial spore germination. While attempting this procedure, it is important to pay close attention to reaction times so that the assay will develop correctly.

Research

JoVE Journal

Immunology and Infection

Saliva, Salivary Gland, and Hemolymph Collection from Ixodes scapularis Ticks

Saliva, Salivary Gland, and Hemolymph Collection from Ixodes scapularis Ticks

A saliva, glândula salivar, e Coleta de hemolinfa de carrapatos Ixodes scapularis

Ticks are found worldwide and afflict humans with many tick-borne illnesses. Ticks are vectors for pathogens that cause Lyme disease and tick-borne ...

Imunologia e Infecção

Bioluminescent Bacterial Imaging In Vivo

Bioluminescent Bacterial Imaging In Vivo

Imagem bacteriana Bioluminescent<em&gt; Em 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 ...

Detecting Glycogen in Peripheral Blood Mononuclear Cells with Periodic Acid Schiff Staining

Detecção de glicogênio no sangue periférico células mononucleares com Periodic Acid Schiff Coloração

Periodic acid Schiff (PAS) staining is an immunohistochemical technique used on muscle biopsies and as a diagnostic tool for blood samples. ...

Electroporation of Functional Bacterial Effectors into Mammalian Cells

A electroporação de efectores bacterianos funcionais em células de mamíferos

The study of protein interactions in the context of living cells can generate critical information about localization, dynamics, and interacting partners. ...

Generation and Multi-phenotypic High-content Screening of Coxiella burnetii Transposon Mutants

Generation and Multi-phenotypic High-content Screening of Coxiella burnetii Transposon Mutants

Geração e Multi-fenotípica rastreio de alto teor de<em&gt; Coxiella burnetii</em&gt; mutantes por transposões

Invasion and colonization of host cells by bacterial pathogens depend on the activity of a large number of prokaryotic proteins, defined as virulence ...

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

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

Métodos para detecção de citotóxicos amiloides seguir infecção de pulmonar células endoteliais por Pseudomonas aeruginosa

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

Spore Adsorption as a Nonrecombinant Display System for Enzymes and Antigens

Adsorção de esporos, como um sistema de exibição Nonrecombinant por enzimas e antígenos

The bacterial spore is a metabolically quiescent cell, formed by a series of protective layers surrounding a dehydrated cytoplasm. This peculiar structure ...

A High-throughput Shigella-specific Bactericidal Assay

A High-throughput Shigella-specific Bactericidal Assay

Um do elevado-throughput Shigella-ensaio bactericida específico

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

Visualization of Bacterial Resistance using Fluorescent Antibiotic Probes

Visualização da resistência bacteriana usando sondas de antibióticos fluorescentes

Fluorescent antibiotics are multipurpose research tools that are readily used for the study of antimicrobial resistance, due to their significant ...

A Neonatal Imaging Model of Gram-Negative Bacterial Sepsis

Um modelo de imagem neonatal de sepse bacteriana gram-negativa

Neonates are at an increased risk of bacterial sepsis due to the unique immune profile they display in the first months of life. We have established a ...