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1. O gotejamento Reactor Biofilm Fluxo <ol><li> O reator de biofilme fluxo de gotejamento (disponível a partir Technologies Biosurface ou personalizado versões projetadas geralmente pode ser feita por oficinas de mecânica da universidade, ver Figura 1) é montado e autoclavada. Assembléia envolve cupons aposição em câmaras e as tampas de câmara de segurança. A câmara, juntamente com o meio biofilme (caldo tripticase soja 2 gramas / L e glicose de 2 gramas / L), e tubos de nutrientes influentes são esterilizados em autoclave. </li><li> Inoculação do reator de fluxo de gotejamento é pré-formado, colocando o reator em uma superfície plana, de fixação das linhas de tubulação de efluentes, preenchendo cada uma das câmaras com 10 mL de caldo de soja tríptica e adicionando 10 mL de um S. cultura aureus cresceu durante a noite em caldo tripticase soja. O reator é inoculado em seguida, coloque em uma incubadora de 37 ° C por 18 horas. </li><li> Após 18 horas de incubação, o tubo efluente é despinçada eo reator é colocado em um bloco de madeira cortada a um ângulo de 10 °. </li><li> Assepticamente conectar a tubulação influentes de nutrientes para o frasco contendo o caldo nutriente fluxo contínuo. Alimentar a linha de tubos através da bomba e os tubos principais, executando a bomba a uma velocidade máxima (irá variar dependendo do modelo da bomba). </li><li> Uma vez que a tubulação afluente está preparado parar a bomba e anexar agulhas connect (calibre 22, 1 polegada) ao final de cada tubo. Limpe a tampa de entrada de câmara com uma limpeza e assepsia do etanol inserir as agulhas através da rolha de entrada. </li><li> Ligue a bomba e deixe que a mídia lentamente por gotejamento (taxa de fluxo de ~ 125 mL / minuto) ao longo dos cupons. A mídia deveria fluxo descendente ao longo do vale do porto rolha de entrada para o porto de efluentes. Operar o reator em fluxo contínuo por 2-5 dias (dependendo da aplicação), ocasionalmente verificar o reator para a drenagem adequada. </li><li> Para colher o gotejamento biofilmes reator de fluxo, parar a bomba e remova cuidadosamente as agulhas do reator. O reator pode ser colocado sobre uma superfície plana e os cupons podem ser assepticamente removidos com pinças estéreis. Se microscopia é desejado, os cupons podem ser processados ​​em conformidade (Figura 2B é uma micrografia eletrônica de varredura de um biofilme de S. aureus cresceu em um reator de biofilme por gotejamento). Se a quantificação da biomassa do biofilme ou estudos de fisiologia são o objetivo do estudo, o biofilme pode ser removida do cupom usando um raspador de celular. Enquanto mantém os cupons com uma pinça, raspe o biofilme off o cupom em um tubo cônico contendo tampão fosfato salino com uma espátula celular. Nota: para quantificar a unidades formadoras de colônias nos biofilmes, é necessário homogeneizar os biofilmes colhida com um lenço de papel homogeneizador para desagregar aglomerados e formar uma suspensão homogênea. Vários modelos de homogeneizadores de tecidos são adequados para esta aplicação. Nós utilizamos um Fisher Scientific Tissuemiser Homogeneizador (produto # 15-338-420) em velocidade máxima durante 1 minuto para homogeneizar as amostras de biofilme. Falta de homogeneizar o biofilme irá resultar em uma subestimação da unidades formadoras de colônias presentes na amostra. </li></ol> 2. O Reactor Biofilm Rotating Disk <ol><li> O reator de biofilme rotação do disco (disponível disponível a partir Technologies Biosurface ou podem ser feitos, veja a Figura 3) é montado e autoclavada. Montar o reator por primeiro lugar a fiação cupons disco nas ranhuras do disco de fiação e colocá-lo em uma proveta de vidro de 1 litro com uma porta de overflow. A número 15 de borracha rolha com furos nele para permitir o fluxo de mídia e aeração é usado como a tampa do reator. O reator, biofilme media (caldo tripticase soja 2 g / L e glicose 2 g / L), e tubulação de entrada são, então, esterilizados em autoclave. </li><li> O reator de biofilme rotação do disco é inoculada, colocando 250 mL de meio estéril para o reator, e adicionando 0,5 mL de uma noite de S. cultura aureus cultivadas em caldo tripticase soja. O reator é então colocado em uma placa de agitação ajustado para 250 rpm e incubados durante a noite na temperatura desejada. </li><li> Após 16 horas de incubação conectar a tubulação de entrada para a porta no reservatório de médio e conectá-lo à bomba peristáltica. A bomba é, então, ligar e fluxo definido como ~ 0,25 mL / min (fluxo pode ser alterada dependendo da taxa de crescimento desejado). </li><li> Depois de 24 horas parada do reator e assepticamente remover o disco, sem tocar os cupons biofilme. Remove os cupons usando uma pinça estéril e mergulhe cada um em tampão fosfato salina para remover qualquer bactéria fracamente ligados. </li><li> Para os testes de compostos antimicrobianos, os chips podem ser colocados em poços individuais de uma placa de 96 poços contendo compostos de interesse. Após a incubação, os chips são transferidos para tubos de 1,5 mL de microcentrífuga contendo 1 mL de tampão fosfato salina e homogeneizado com um lenço de papel homogeneizador para dispersar o biofilme intacta. </li><li> Células são então diluídas em série e semeados em ágar nutriente para determinar viável colônia formiunidades ng. </li><li> Nota: muitas variações podem ser feitas no protocolo acima. Por exemplo, disco giratório cupons podem ser revestidos com ou feito de potenciais compostos anti-biofilme para testar a eficácia. Dispersantes biofilme pode ser avaliada também estar a incubar cupons em compostos dispersantes e bactérias quantificar anexado contra destacados. </li></ol> 3. Resultados representante Um exemplo de um conjunto de reator de fluxo de gotejamento é mostrado se a Figura 1. Após três dias de fluxo de grandes quantidades de biofilme se acumulam na superfície do cupom, Figura 2A. A biomassa total irá variar de acordo com cepas bacterianas e condições de crescimento precisa. A micrografia eletrônica de varredura de um S. biofilme aureus cresceu no reator de fluxo de gotejamento é mostrado na Figura 2B. Um reator de disco rotativo é mostrado na figura 3A. O protocolo descrito podem ser adaptados às necessidades específicas de qualquer microorganismo geralmente capaz de formar um biofilme. Figura 3B mostra o disco giratório com 18 discos de plástico aposta. Estes biofilmes disco-grown são particularmente bem adaptado para testes antimicrobianos e produzir resultados altamente reprodutíveis 11. <img src="/files/ftp_upload/2470/2470fig1.jpg" alt="Figura 1" /> Figura 1. Gotejamento configuração do reator de fluxo. Componentes importantes são rotulados. <img src="/files/ftp_upload/2470/2470fig2.jpg" alt="Figura 2" /> Figura 2. Exemplo de um fluxo de gotejamento S. biofilme aureus. A) O biofilme foi cultivado por três dias após o protocolo descrito. Tampas das duas primeiras câmaras do reator são removidos para mostrar a S. amarela biomassa biofilme aureus. B) Sacnning micrografia eletrônica de um S. biofilme aureus cresceu no reator de fluxo de gotejamento. <img src="/files/ftp_upload/2470/2470fig3.jpg" alt="Figura 3" /> Figura 3. O reator disco rotativo. A) Exemplo de um reator de disco executando spinning. Componente-chave são rotulados. B) Feche acima da vista de um disco giratório.

<ol>
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K., Stewart, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+growing+a+biofilm+under+low+shear+at+the+air-liquid+interface+using+the+drip+flow+biofilm+reactor.">A method for growing a biofilm under low shear at the air-liquid interface using the drip flow biofilm reactor.</a> Nature Protocols. 4, 783-788 (2009).</li><li>Fu, W., Forster, T., Mayer, O., Curtin, J. J., Lehman, S. M., Donlan, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bacteriophage+cocktail+for+the+prevention+of+biofilm+formation+by+Pseudomonas+aeruginosa+on+catheters+in+an+in+vitro+model+system.">Bacteriophage cocktail for the prevention of biofilm formation by Pseudomonas aeruginosa on catheters in an in vitro model system.</a> Antimicrob Agents Chemother. 54, 397-404 (2010).</li><li>Xu, K. D., McFeters, G. 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Não há conflitos de interesse declarados.

Biofilmes cultivados em reatores diferentes, muitas vezes, têm características diferentes e cada reator tem aplicações diferentes. Neste trabalho, descrevemos a utilização de dois reatores de biofilme: um reator de biofilme por gotejamento e um reator de fluxo de disco rotativo. Reatores de fluxo de gotejamento são úteis para o crescimento de biofilmes baixo cisalhamento de uma interface ar-líquido e são adaptáveis ​​a uma variedade de condições. Encontramo-las extremamente conveniente para estudos, ond...

Erratum: The Use of Drip Flow and Rotating Disk Reactors for Staphylococcus aureus Biofilm Analysis

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<td>Drip Flow Reactors</td>
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<td>BioSurface Technologies Corporation</td>
<td>DFR 110</td>
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<td>Rotating Disk Reactors</td>
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<td>BioSurface Technologies Corporation</td>
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the use of drip flow and rotating disk reactors for staphylococcus aureus biofilm analysis

A maioria dos micróbios na natureza são pensados ​​para existir como superfície associados comunidades em biofilmes. Um biofilme bacteriano são encerradas dentro de uma matriz e anexado a uma superfície de formação de biofilmes. 2 e desenvolvimento são comumente estudados em laboratório, utilizando sistemas de lote, tais como placas de microtitulação ou fluxo sistemas, tais como o fluxo de células. Estas metodologias são úteis para triagem bibliotecas mutante e química (placas de microtitulação) 3 ou crescente biofilmes para visualização (células de fluxo) 4. Aqui apresentamos protocolos detalhados para Staphylococcus aureus crescendo em dois tipos adicionais de biofilmes sistema de fluxo: o gotejamento reator biofilme fluxo e reator de biofilme rotação do disco. Reatores de gotejamento biofilme de fluxo são projetados para o estudo de biofilmes cultivados sob condições de cisalhamento baixa. 5 O reator de fluxo de gotejamento consiste em quatro canais de teste em paralelo, cada um capaz de manter um padrão de vidro cupom lâmina de microscópio de tamanho, ou um comprimento de cateter ou stint. O reator de fluxo de gotejamento é ideal para monitoramento microsensor, estudos gerais biofilme, as amostras de biofilme cryosectioning, alta produção de biomassa, as avaliações material médico e teste de dispositivo de habitação médica. 6,7,8,9 O reator de disco giratório consiste em um disco de teflon contêm recessos para cupons removível. 10 Os cupons podem removível pelo feito de qualquer material usinável. A parte inferior do disco rotativo contém um ímã de barra para permitir a rotação de disco de corte para criar superfície do líquido sobre a superfície de descarga cupons. Todo o disco contendo 18 cupons é colocado em um copo mL mil vaso do reator lado-braço. Um meio de crescimento líquido é circulado através do navio enquanto o disco é girado por um agitador magnético. Os cupons são removidos do reator e, em seguida, raspado para coletar a amostra de biofilme para estudos adicionais ou imagens de microscopia. Reatores disco rotativo são projetados para avaliações laboratoriais de eficácia biocida, a remoção do biofilme eo desempenho do anti-incrustantes materiais. 9,11,12,13

Watch this Scientific Journal Video about The Use of Drip Flow and Rotating Disk Reactors for Staphylococcus aureus Biofilm Analysis at JoVE.com

The Use of Drip Flow and Rotating Disk Reactors for Staphylococcus aureus Biofilm Analysis

Protocolos para a utilização de biofilmes fluxo de abrir o sistema com reatores de fluxo de gotejamento e girando reatores disco são apresentadas em detalhe.

O uso do fluxo de gotejamento e Reatores de disco rotativo para Staphylococcus aureus Análise de biofilme

Most microbes in nature are thought to exist as surface-associated communities in biofilms.1  Bacterial biofilms are encased within a matrix and attached ...

the-use-drip-flow-rotating-disk-reactors-for-staphylococcus-aureus

Research

JoVE Journal

Immunology and Infection

The Use of Drip Flow and Rotating Disk Reactors for Staphylococcus aureus Biofilm Analysis

17.0K visualizações.  University of Michigan. Protocolos para a utilização de biofilmes fluxo de abrir o sistema com reatores de fluxo de gotejamento e girando reatores disco são apresentadas em detalhe.

Vídeo: The Use of Drip Flow and Rotating Disk Reactors for Staphylococcus aureus Biofilm Analysis

Pseudomonas aeruginosa and Saccharomyces cerevisiae Biofilm in Flow Cells

Many microbial cells have the ability to form sessile microbial communities defined as biofilms that have altered physiological and pathological properties compared to free living microorganisms. Biofilms in nature are often difficult to investigate and reside under poorly defined conditions1. Using a transparent substratum it is possible to device a system where simple biofilms can be examined in a non-destructive way in real-time: here we demonstrate the assembly and operation of a flow cell model system, for in vitro 3D studies of microbial biofilms generating high reproducibility under well-defined conditions2,3.
The system consists of a flow cell that serves as growth chamber for the biofilm. The flow cell is supplied with nutrients and oxygen from a medium flask via a peristaltic pump and spent medium is collected in a waste container. This construction of the flow system allows a continuous supply of nutrients and administration of e.g. antibiotics with minimal disturbance of the cells grown in the flow chamber. Moreover, the flow conditions within the flow cell allow studies of biofilm exposed to shear stress. A bubble trapping device confines air bubbles from the tubing which otherwise could disrupt the biofilm structure in the flow cell.
The flow cell system is compatible with Confocal Laser Scanning Microscopy (CLSM) and can thereby provide highly detailed 3D information about developing microbial biofilms. Cells in the biofilm can be labeled with fluorescent probes or proteins compatible with CLSM analysis. This enables online visualization and allows investigation of niches in the developing biofilm. Microbial interrelationship, investigation of antimicrobial agents or the expression of specific genes, are of the many experimental setups that can be investigated in the flow cell system.

Pseudomonas aeruginosa and Saccharomyces cerevisiae Biofilm in Flow Cells

Protocol describing the application of a flow cell system for growing and analyzing microbial biofilms for Confocal Laser Scanning Microscopy (CLSM).

Pseudomonas aeruginosa e Saccharomyces cerevisiae Biofilme em Células de Fluxo

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

Imunologia e Infecção

Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus (MRSA)

MRSA is a worldwide threat to public health, and MRSA skin and soft-tissue infections now account for more than half of all soft-tissue infections in the United States. Among soft-tissue infections, myositis, pyomyositis, and necrotizing fasciitis have been increasingly reported in association with MRSA arising from the community. To understand the interplay between MRSA and host immunity leading to more severe infection, the availability of animal models is critical, permitting the study of host and bacterial factors. Several infection models have been introduced to assess the pathogenesis of S. aureus during superficial skin infection. Here, we describe a subcutaneous infection model that examines the skin, subcutaneous, and muscle pathologies.

Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus MRSA

Murine skin and soft tissue infection model is utilized for assessing the virulence function of methicillin resistant Staphylococcus aureus (MRSA) and the host immunological responses. Here, we presented a subcutaneous infection model for skin and soft tissue infection.

Infecção subcutânea de Staphylococcus aureus resistente (MRSA)

MRSA is a worldwide threat to public health, and MRSA skin and soft-tissue infections now account for more than half of all soft-tissue infections in the ...

Experimental Endocarditis Model of Methicillin Resistant Staphylococcus aureus (MRSA) in Rat

Endovascular infections, including endocarditis, are life-threatening infectious syndromes1-3. Staphylococcus aureus is the most common world-wide cause of such syndromes with unacceptably high morbidity and mortality even with appropriate antimicrobial agent treatments4-6. The increase in infections due to methicillin-resistant S. aureus (MRSA), the high rates of vancomycin clinical treatment failures and growing problems of linezolid and daptomycin resistance have all further complicated the management of patients with such infections, and led to high healthcare costs7, 8. In addition, it should be emphasized that most recent studies with antibiotic treatment outcomes have been based in clinical settings, and thus might well be influenced by host factors varying from patient-to-patient. Therefore, a relevant animal model of endovascular infection in which host factors are similar from animal-to-animal is more crucial to investigate microbial pathogenesis, as well as the efficacy of novel antimicrobial agents. Endocarditis in rat is a well-established experimental animal model that closely approximates human native valve endocarditis. This model has been used to examine the role of particular staphylococcal virulence factors and the efficacy of antibiotic treatment regimens for staphylococcal endocarditis. In this report, we describe the experimental endocarditis model due to MRSA that could be used to investigate bacterial pathogenesis and response to antibiotic treatment.

Experimental Endocarditis Model of Methicillin Resistant Staphylococcus aureus MRSA in Rat

Experimental rat endocarditis model due to methicillin-resistant S. aureus.

Modelo Experimental de Endocardite resistente à meticilina<em&gt; Staphylococcus aureus</em&gt; (MRSA) em Rato

Endovascular infections, including endocarditis, are life-threatening infectious syndromes1-3. Staphylococcus aureus is the most common world-wide cause ...

Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source

S. aureus is a pathogenic bacterium that requires iron to carry out vital metabolic functions and cause disease. The most abundant reservoir of iron inside the human host is heme, which is the cofactor of hemoglobin. To acquire iron from hemoglobin, S. aureus utilizes an elaborate system known as the iron-regulated surface determinant (Isd) system1. Components of the Isd system first bind host hemoglobin, then extract and import heme, and finally liberate iron from heme in the bacterial cytoplasm2,3. This pathway has been dissected through numerous in vitro studies4-9. Further, the contribution of the Isd system to infection has been repeatedly demonstrated in mouse models8,10-14. Establishing the contribution of the Isd system to hemoglobin-derived iron acquisition and growth has proven to be more challenging. Growth assays using hemoglobin as a sole iron source are complicated by the instability of commercially available hemoglobin, contaminating free iron in the growth medium, and toxicity associated with iron chelators. Here we present a method that overcomes these limitations. High quality hemoglobin is prepared from fresh blood and is stored in liquid nitrogen. Purified hemoglobin is supplemented into iron-deplete medium mimicking the iron-poor environment encountered by pathogens inside the vertebrate host. By starving S. aureus of free iron and supplementing with a minimally manipulated form of hemoglobin we induce growth in a manner that is entirely dependent on the ability to bind hemoglobin, extract heme, pass heme through the bacterial cell envelope and degrade heme in the cytoplasm. This assay will be useful for researchers seeking to elucidate the mechanisms of hemoglobin-/heme-derived iron acquisition in S. aureus and possibly other bacterial pathogens.

Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source

Here we describe a growth assay for Staphylococcus aureus using hemoglobin as the sole source of available nutrient iron. This assay establishes the role of bacterial factors involved in hemoglobin-derived iron acquisition.

Staphylococcus aureus usando hemoglobina humana como uma fonte de ferro

S. aureus is a pathogenic bacterium that requires iron to  carry out vital metabolic functions and cause disease. The most abundant  reservoir of iron ...

Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus

Staphylococcal Cassette Chromosome mec (SCCmec) typing is a very important molecular tool for understanding the epidemiology and clonal strain relatedness of methicillin-resistant Staphylococcus aureus (MRSA), particularly with the emerging outbreaks of community-associated MRSA (CA-MRSA) occurring on a worldwide basis. Traditional PCR typing schemes classify SCCmec by targeting and identifying the individual mec and ccr gene complex types, but require the use of many primer sets and multiple individual PCR experiments. We designed and published a simple multiplex PCR assay for quick-screening of major SCCmec types and subtypes I to V, and later updated it as new sequence information became available. This simple assay targets individual SCCmec types in a single reaction, is easy to interpret and has been extensively used worldwide. However, due to the sophisticated nature of the assay and the large number of primers present in the reaction, there is the potential for difficulties while adapting this assay to individual laboratories. To facilitate the process of establishing a MRSA SCCmec assay, here we demonstrate how to set up our multiplex PCR assay, and discuss some of the vital steps and procedural nuances that make it successful.

Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus

We demonstrate a simple multiplex PCR assay for quick-screening and typing of Staphylococcal Cassette Chromosome mec (SCCmec) types I-V for methicillin-resistant Staphylococcus aureus, and provide some of the vital steps and procedural nuances that make it successful for adapting this assay to individual laboratories.

Multiplex PCR Ensaio para a digita

Staphylococcal Cassette Chromosome mec (SCCmec) typing  is a very important molecular tool for understanding the epidemiology and  clonal strain ...

Studying Interactions of Staphylococcus aureus with Neutrophils by Flow Cytometry and Time Lapse Microscopy

We present methods to study the effect of phenol soluble modulins (PSMs) and other toxins produced and secreted by Staphylococcus aureus on neutrophils. To study the effects of the PSMs on neutrophils we isolate fresh neutrophils using density gradient centrifugation. These neutrophils are loaded with a dye that fluoresces upon calcium mobilization. The activation of neutrophils by PSMs initiates a rapid and transient increase in the free intracellular calcium concentration. In a flow cytometry experiment this rapid mobilization can be measured by monitoring the fluorescence of a pre-loaded dye that reacts to the increased concentration of free Ca2+. Using this method we can determine the PSM concentration necessary to activate the neutrophil, and measure the effects of specific and general inhibitors of the neutrophil activation.	
	To investigate the expression of the PSMs in the intracellular space, we have constructed reporter fusions of the promoter of the PSM&alpha; operon to GFP. When these reporter strains of S. aureus are phagocytosed by neutrophils, the induction of expression can be observed using fluorescence microscopy.

Studying Interactions of Staphylococcus aureus with Neutrophils by Flow Cytometry and Time Lapse Microscopy

We present methods to study the effect of PSMs and other toxins secreted by Staphylococcus aureus on neutrophils using flow cytometry and fluorescence microscopy.

Estudo das interacções de<em&gt; Staphylococcus aureus</em&gt; Com neutrófilos por citometria de fluxo e Time Lapse Microscopy

We present methods to study the effect of phenol soluble modulins (PSMs)  and other toxins produced and secreted by Staphylococcus  aureus on neutrophils. ...

Targeting Biofilm Associated Staphylococcus aureus Using Resazurin Based Drug-susceptibility Assay

Most pathogenic bacteria are able to form biofilms during infection, but due to the difficulty of manipulating and assessing biofilms, the vast majority of laboratory work is conducted with planktonic cells. Here, we describe a peg plate biofilm assay as performed with Staphylococcus aureus. Bacterial biofilms are grown on pegs attached to a 96-well microtiter plate lid, washed through gentle submersion in buffer, and placed in a drug challenge plate. After subsequent incubation they are again washed and moved to a final recovery plate, in which the fluorescent dye resazurin serves as a viability indicator. This assay offers greatly increased ease-of-use, reliability, and reproducibility, as well as a wealth of data when conducted as a kinetic read. Moreover, this assay can be adapted to a medium-throughput drug screening approach by which an endpoint fluorescent readout is taken instead, offering a path for drug discovery efforts.

Targeting Biofilm Associated Staphylococcus aureus Using Resazurin Based Drug-susceptibility Assay

Most bacterial infections produce a biofilm. By virtue of their environment, biofilm associated bacteria are often phenotypically drug resistant. Novel antibacterial molecules that kill bacteria in biofilms are thus a high priority. We establish an assay to quickly screen for antimicrobial compounds that are effective at eradicating biofilms.

Segmentação de biofilme Associated<em&gt; Staphylococcus aureus</em&gt; Usando resazurina Baseado Ensaio Drogas susceptibilidade

Most pathogenic bacteria are able to form biofilms during infection, but due to the difficulty of manipulating and assessing biofilms, the vast majority ...

Genotyping of Staphylococcus aureus by Ribosomal Spacer PCR (RS-PCR)

The ribosomal spacer PCR (RS-PCR) is a highly resolving and robust genotyping method for S. aureus that allows a high throughput at moderate costs and is, therefore, suitable to be used for routine purposes. For best resolution, data evaluation and data management, a miniaturized electrophoresis system is required. Together with such an electrophoresis system and the in-house developed software (freely available here) assignment of the pattern of bands to a genotype is standardized and straight forward. DNA extraction is simple (boiling prep), setting-up of the reactions is easy and they can be run on any standard PCR machine. PCR cycling is common except prolonged ramping and elongation times. Compared to spa typing and Multi Locus Sequence Typing (MLST), RS-PCR does not require DNA sequencing what simplifies the analysis considerably and allows a high throughput. Furthermore, the resolution for bovine strains of S. aureus is at least as good as spa typing and better than MLST or pulsed-field gel electrophoresis (PFGE). The RS-PCR data base includes presently a total of 141 genotypes and variants. The method is highly associated with the virulence gene pattern, contagiosity and pathogenicity of S. aureus strains involved in bovine mastitis. S. aureus genotype B (GTB) is contagious and causes herds problems causing large costs in the Switzerland and other European countries. All the other genotypes observed in Switzerland infect individual cows and quarters. Genotyping by RS-PCR allows the reliable prediction of the epidemiological and the pathogenic potential of S. aureus involved in bovine intramammary infection (IMI), two key factors for clinical veterinary medicine. Because of these beneficial properties together with moderate costs and a high sample throughput the goal of this publication is to give a detailed, step-by-step protocol for easily establishing and running RS-PCR for genotyping S. aureus in other laboratories.

Genotyping of Staphylococcus aureus by Ribosomal Spacer PCR RS-PCR

Here, ribosomal spacer PCR (RS-PCR) is used together with a miniaturized electrophoresis system as a fast and high resolution method for genotyping S. aureus at moderate costs allowing a high throughput.

genotipagem de<em&gt; Staphylococcus aureus</em&gt; por Ribossômico Spacer PCR (RS-PCR)

The ribosomal spacer PCR (RS-PCR) is a highly resolving and robust genotyping method for S. aureus that allows a high throughput at moderate costs and is, ...

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus

One important feature of the major opportunistic human pathogen Staphylococcus aureus is its extraordinary ability to rapidly acquire resistance to antibiotics. Genomic studies reveal that S. aureus carries many virulence and resistance genes located in mobile genetic elements, suggesting that horizontal gene transfer (HGT) plays a critical role in S. aureus evolution. However, a full and detailed description of the methodology used to study HGT in S. aureus is still lacking, especially regarding natural transformation, which has been recently reported in this bacterium. This work describes three protocols that are useful for the in vitro investigation of HGT in S. aureus: conjugation, phage transduction, and natural transformation. To this aim, the cfr gene (chloramphenicol/florfenicol resistance), which confers the Phenicols, Lincosamides, Oxazolidinones, Pleuromutilins, and Streptogramin A (PhLOPSA)-resistance phenotype, was used. Understanding the mechanisms through which S. aureus transfers genetic materials to other strains is essential to comprehending the rapid acquisition of resistance and helps to clarify the modes of dissemination reported in surveillance programs or to further predict the spreading mode in the future.

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus

We describe here three different protocols for the in vitro investigation of conjugation, transduction, and natural transformation in Staphylococcus aureus.

Metodologia para o Estudo da transferência horizontal de genes em<em&gt; Staphylococcus aureus</em

One important feature of the major opportunistic human pathogen Staphylococcus aureus is its extraordinary ability to rapidly acquire resistance to ...

Characterization of Human Monocyte Subsets by Whole Blood Flow Cytometry Analysis

Monocytes are key contributors in various inflammatory disorders and alterations to these cells, including their subset proportions and functions, can have pathological significance. An ideal method for examining alterations to monocytes is whole blood flow cytometry as the minimal handling of samples by this method limits artifactual cell activation. However, many different approaches are taken to gate the monocyte subsets leading to inconsistent identification of the subsets between studies. Here we demonstrate a method using whole blood flow cytometry to identify and characterize human monocyte subsets (classical, intermediate, and non-classical). We outline how to prepare the blood samples for flow cytometry, gate the subsets (ensure contaminating cells have been removed), and determine monocyte subset expression of surface markers &#8212; in this example M1 and M2 markers. This protocol can be extended to other studies that require a standard gating method for assessing monocyte subset proportions and monocyte subset expression of other functional markers.

Here we present a protocol for characterizing monocyte subsets by whole blood flow cytometry. This includes outlining how to gate the subsets and assess their expression of surface markers and giving an example of the assessment of the expression of M1 (inflammatory) and M2 markers (anti-inflammatory).

Caracterização de subconjuntos de monócitos humanos por sangue total Flow Cytometry Analysis

Monocytes are key contributors in various inflammatory disorders and alterations to these cells, including their subset proportions and functions, can ...