这项研究是由美国公共卫生服务补助AI69233和AI073843从国家过敏和传染病研究所的支持。 EPS是一个巴勒斯惠康研究员，传染病的发病机制。 KPH是由细胞与分子微生物学培训补助计划5 T32 A107611-10。

1。从新鲜血液中的血红蛋白纯化<ol><li>收购辅以抗凝剂的人新鲜血液。血液在冰上或4℃下保持整个纯化过程。 </li><li> 20分钟，于1500×g离心血液。的红血细胞（红细胞）将在试管底部。小心地吸出上清液，并轻轻将沉淀重悬于冰冷的0.9％（重量/体积）NaCl溶液。重复离心和洗涤3次。 </li><li>在1倍体积的冰冷却的10mM Tris-HCl（pH值8.0）中重悬沉淀。这将诱导的红细胞由于渗透压的裂解。添加甲苯〜20％的最终体积。 </li><li>在烤肉在4°C孵育过夜。 </li><li>离心裂解液以20,000 xg离心1小时。收集的中间溶血离开甲苯（浮在上面）和颗粒不变的部分。用长脖子吸管收集中间馏分。 </li><li>通过0.44微米针头式过滤器。如果溶液含有颗粒物质和不能可以通过过滤器，重复步骤1.5。 </li><li>纯化血红蛋白（Hb）与一个高性能的液相色谱法（HPLC）的阴离子交换柱（Varian，PL-SAX 1,000埃8μm的，150毫米×4.6毫米）。流动相A为10 mM Tris-盐酸（pH8.0）和流动相B是10 mM Tris-盐酸（pH值8.0）+ 0.5 M氯化钠。 A 0％-100％的溶剂B的梯度运行在2.0毫升/分钟的流量超过2分钟。监测洗脱基于吸收（λ:410 nm和280 nm）。仅收集部分，特点是明亮的红色和显着的吸收峰（ 图1）。 </li><li>透析洗脱对磷酸盐缓冲盐水（PBS）过夜，然后再次在几个小时。通过0.22μm的注射器过滤器灭菌。 </li><li>为了测量血红蛋白浓度，准备的标准血红蛋白解决方案的已知浓度的PBS。确定样品中的血红蛋白浓度的混合标准溶液（请参阅下表我们与试剂编辑）或的样品溶液与2倍德拉布坎的试剂（从粉末制备）按1:1的比例。例如，与100μl的2×德拉布坎的试剂在96孔板中混合100μl的血红蛋白溶液。孵育15分钟，并测量在540nm处的吸光度。绘制标准曲线，确定试样中的Hb浓度。五至15毫克/毫升的产量是典型的。 </li><li>运行15〜20μg纯化血红蛋白在15％SDS-PAGE，一式两份。染色凝胶之一;从另一个凝胶中的蛋白质转移到硝酸纤维素膜和免疫印迹血红蛋白（ 图2）。 </li><li>冻结和储存在液氮中的血红蛋白的1ml等分。 </li></ol> 2。铁消耗培养基<ol><li>准备罗斯威尔公园Memorial研究所（RPMI）肉汤通过溶解的RPMI粉末在水中，由生产商和1％cassamino酸（CA）（重量/体积）的建议，添加碳酸氢钠。通过0.2μm的过滤器和存储冷柜灭菌纳入样本内。 </li><li>准备金属贫的RPMI（NRPMI）的通过添加7％（w / v的）Chelex 100上的搅拌板和混合过夜。通过0.2μm的过滤器和存储冷藏删除Chelex 100。与基本的非铁金属:25μM的ZnCl 2，25μM的MnCl 2，100mM的CaCl 2和1mM MgCl 2预先准备的作为无菌1,000×溶液补编媒体。使用一次性的塑料容器中，此步骤可重复使用的用品，以避免铁污染。 </li></ol> 3， 金黄色葡萄球菌生长血红蛋白作为唯一的铁源<ol><li>数S.金黄色葡萄球菌隔离胰蛋白酶大豆琼脂（TSA）从冻结的股票。在37°C培养20〜24小时。 </li><li>重悬的乙二胺-N，N&#39;-双（2 - 羟基苯基乙酸）（EDDHA）在无水乙醇至100mM。 EDDHA不进入的解决方案，但乙醇灭菌。 </li><li>加入EDDHA的RPMI至终浓度为0.5mM。让EDDHA溶解至少30分钟，然后再进行下一个步骤。由于批与批之间的变化，最终的EDDHA浓度可能需要降低至0.25 mM的允许细菌生长。 </li><li> ，接种单菌落S.分为5毫升的RPMI含有EDDHA带螺旋帽的在15毫升锥形管中的金黄色葡萄球菌 。在37℃下孵育16-20小时，在180转每分钟（rpm）振荡。 </li><li> 7500 XG 5分钟离心过夜培养和悬浮颗粒在NRPMI含有0.5mM EDDHA。规格化OD 600〜3。 </li><li>准备NRPMI含2.5微克每毫升HB和0.1-1.0毫米EDDHA。由于各批次之间的变化，的EDDHA浓度螯合铁在NRPMI的可能会有所不同。 </li><li>继代培养10微升的步骤3.51毫升NRPMI + EDDHA + Hb在15毫升螺旋盖的锥形管的菌悬液。 </li><li>孵育在37℃下培养至48小时，在180 rpm或轧制鼓上摇动。 </li><l&gt;每6-12小时采取的OD 600读数通过去除培养的50微升，在96 -孔板中，用150μl的PBS混合。 </li></ol>

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我们什么都没有透露。

铁是人体必需的营养物质，生物王国的寿命15。在脊椎动物中，铁被隔离，以避免造成此元素的毒性。封存也掩盖铁入侵的微生物的过程被称为营养免疫16。对此，病原体已经发展策略，规避营养的免疫力。一种这样的机制依赖于血红蛋白，这是最丰富的铁源内的主机17。血红蛋白被包含在红血细胞。血红蛋白受损的红血细胞释放的约束的主机结合珠蛋白，这标志着快速去?...

<table border="1"><tbody><tr><td> 的试剂/材料名称 </td><td> 公司 </td><td> 目录编号 </td><td> 评论 </td></tr><tr><td>高效液相色谱法的阴离子交换柱</td><td>瓦里安</td><td> PL1551-3802 </td><td></td></tr><tr><td>德拉布坎试剂</td><td>西格玛</td><td> D5941-6VL </td><td></td></tr><tr><td>血红蛋白标准</td><td>足尖科学</td><td> H7506-STD </td><td></td></tr><tr><td> RPMI </td><td>胎牛血清</td><td> SH30011.02 </td><td></td></tr><tr><td> Chelex 100钠型</td><td>西格玛</td><td> C7901 </td><td></td></tr><tr><td> EDDHA </td><td> LGC标准公司</td><td> ANC 001 </td><td></td></tr><tr><td>血红蛋白A抗体</td><td>圣克鲁斯生物技术公司</td><td> SC-21005 </td><td> &lt;/ TD&gt; </tr><tr><td>胰蛋白酶大豆琼脂</td><td> BD </td><td> 236920 </td><td></td></tr></tbody></table>

staphylococcus aureus growth using human hemoglobin as an iron source

金黄色葡萄球菌是一种致病细菌，需要铁来进行重要的代谢功能，导致疾病的。储层人类宿主内的铁是最丰富的血红素，这是血红蛋白的辅因子。为了获得铁血红蛋白，S.金黄色葡萄球菌利用一个复杂的系统，被称为铁规管表面的行列式（ISD）系统1。 ISD系统首次绑定主机血红蛋白的组成部分，然后提取并导入血红素，和，终于解放血红素铁在细菌胞浆2,3。通过这条途径已解剖众多的体外研究4-9。此外，ISD系统感染的贡献已被反复证明在小鼠模型中8,10-14。建立血红蛋白衍生的铁收购和增长的贡献ISD系统已被证明是更具挑战性的。生长测定血红蛋白作为唯一的铁源是复杂的by是不稳定市售血红蛋白，在生长培养基中的游离铁污染，并与铁螯合剂毒性。在这里，我们提出了一种方法，该方法克服了这些限制。从新鲜血液中制备高品质的血红蛋白，并储存于液氮中。纯化血红蛋白补充铁消耗介质模仿铁所遇到的脊椎动物宿主病原体内的恶劣环境。饥饿S.黄色葡萄球菌的最小操纵形式的血红蛋白诱导生长的方式，结合血红蛋白，提取血红素，通过血红素通过细菌的细胞壁，并降低在细胞质中的血红素的能力完全依赖于铁和补充。此法将有助于研究人员寻找阐明机制的hemoglobin-/heme-derived铁收购S.金黄色葡萄球菌和其他可能的细菌病原体。

我们人体血红蛋白溶血纯化与HPLC（协议1.7步）。 图1显示了记录洗脱液在280和410 nm波长的吸光度。收集的级分5，以及其它馏分被丢弃。五到十五毫克每毫升洗脱液血红蛋白，产量的影响通常是获得。纯化血红蛋白，一式两份，并通过SDS-PAGE分析，凝胶或蛋白质的染色，或转移到硝酸纤维素和免疫印迹（议定书步骤1.10， 图2）。 我们已评估纯化的人血?...

Watch this Scientific Journal Video about Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source at JoVE.com

Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source

在这里，我们描述一个生长实验<em&gt;金黄色葡萄球菌</em使用血红蛋白作为有效养分铁的唯一来源。此法规定参与血红蛋白衍生的铁收购的细菌因素的作用。

金黄色葡萄球菌生长使用人血红蛋白作为铁源

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

staphylococcus-aureus-growth-using-human-hemoglobin-as-an-iron-source

Research

JoVE Journal

Immunology and Infection

Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source

16.5K 次观看.  Vanderbilt University Medical School. 在这里，我们描述一个生长实验金黄色葡萄球菌

视频: Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source

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

Most microbes in nature are thought to exist as surface-associated communities in biofilms.1 Bacterial biofilms are encased within a matrix and attached to a surface.2 Biofilm formation and development are commonly studied in the laboratory using batch systems such as microtiter plates or flow systems, such as flow-cells. These methodologies are useful for screening mutant and chemical libraries (microtiter plates)3 or growing biofilms for visualization (flow cells)4. Here we present detailed protocols for growing Staphylococcus aureus in two additional types of flow system biofilms: the drip flow biofilm reactor and the rotating disk biofilm reactor.
Drip flow biofilm reactors are designed for the study of biofilms grown under low shear conditions.5 The drip flow reactor consists of four parallel test channels, each capable of holding one standard glass microscope slide sized coupon, or a length of catheter or stint. The drip flow reactor is ideal for microsensor monitoring, general biofilm studies, biofilm cryosectioning samples, high biomass production, medical material evaluations, and indwelling medical device testing.6,7,8,9
The rotating disk reactor consists of a teflon disk containing recesses for removable coupons.10 The removable coupons can by made from any machinable material. The bottom of the rotating disk contains a bar magnet to allow disk rotation to create liquid surface shear across surface-flush coupons. The entire disk containing 18 coupons is placed in a 1000 mL glass side-arm reactor vessel. A liquid growth media is circulated through the vessel while the disk is rotated by a magnetic stirrer. The coupons are removed from the reactor vessel and then scraped to collect the biofilm sample for further study or microscopy imaging. Rotating disc reactors are designed for laboratory evaluations of biocide efficacy, biofilm removal, and performance of anti-fouling materials.9,11,12,13

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

Protocols for utilizing open system flow biofilms with drip flow reactors and rotating disk reactors are presented in detail.

滴流和旋转盘反应器使用金黄色葡萄球菌生物膜分析

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

科研

免疫与感染

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.

皮下感染耐甲氧西林金黄色葡萄球菌（MRSA）的

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 ...

Cost-effective Method for Microbial Source Tracking Using Specific Human and Animal Viruses

Microbial contamination of the environment represents a significant health risk. Classical bacterial fecal indicators have shown to have significant limitations, viruses are more resistant to many inactivation processes and standard fecal indicators do not inform on the source of contamination. The development of cost-effective methods for the concentration of viruses from water and molecular assays facilitates the applicability of viruses as indicators of fecal contamination and as microbial source tracking (MST) tools. Adenoviruses and polyomaviruses are DNA viruses infecting specific vertebrate species including humans and are persistently excreted in feces and/or urine in all geographical areas studied. In previous studies, we suggested the quantification of human adenoviruses (HAdV) and JC polyomaviruses (JCPyV) by quantitative PCR (qPCR) as an index of human fecal contamination. Recently, we have developed qPCR assays for the specific quantification of porcine adenoviruses (PAdV) and bovine polyomaviruses (BPyV) as animal fecal markers of contamination with sensitivities of 1-10 genome copies per test tube. In this study, we present the procedure to be followed to identify the source of contamination in water samples using these tools. As example of representative results, analysis of viruses in ground water presenting high levels of nitrates is shown.
Detection of viruses in low or moderately polluted waters requires the concentration of the viruses from at least several liters of water into a much smaller volume, a procedure that usually includes two concentration steps in series. This somewhat cumbersome procedure and the variability observed in viral recoveries significantly hamper the simultaneous processing of a large number of water samples.
In order to eliminate the bottleneck caused by the two-step procedures we have applied a one-step protocol developed in previous studies and applicable to a diversity of water matrices. The procedure includes: acidification of ten-liter water samples, flocculation by skimmed milk, gravity sedimentation of the flocculated materials, collection of the precipitate and centrifugation, resuspension of the precipitate in 10 ml phosphate buffer. The viral concentrate is used for the extraction of viral nucleic acids and the specific adenoviruses and polyomaviruses of interest are quantified by qPCR. High number of samples may be simultaneously analyzed using this low-cost concentration method.
The procedure has been applied to the analysis of bathing waters, seawater and river water and in this study, we present results analyzing groundwater samples. This high-throughput quantitative method is reliable, straightforward, and cost-effective.

The study describes a cost-effective method for the identification of the source of fecal/urine contamination or contamination by nitrates in water using qPCR for the specific quantification of human/porcine/bovine DNA viruses, adenoviruses and polyomaviruses, proposed as MST tools.

微生物源使用特定的人类和动物病毒的追踪成本效益的方法

Microbial contamination of the environment represents a significant health risk. Classical bacterial fecal indicators have shown to have significant ...

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.

耐甲氧西林实验性心内膜炎模型<em&gt;金黄色葡萄球菌</em&gt;（MRSA）的大鼠

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

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.

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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.

相互作用的研究<em&gt;金黄色葡萄球菌</em与中性粒细胞通过流式细胞仪和时间推移显微镜

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.

针对相关生物膜<em&gt;金黄色葡萄球菌</em&gt;使用基于刃天青药物敏感性测定

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.

基因分型<em&gt;金黄色葡萄球菌</em&gt;由核糖体垫片的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.

方法基因水平转移的研究<em&gt;金黄色葡萄球菌</em

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

A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection

Staphylococcus aureus (S. aureus)&#160;infections, including methicillin resistant stains, are an enormous burden on the healthcare system. With incidence rates of S. aureus infection climbing annually, there is a demand for additional research in its&#160;pathogenicity. Animal models of infectious disease advance our understanding of the host-pathogen response and lead to the development of effective therapeutics. Neutrophils play a primary role in the innate immune response that controls S. aureus infections by forming an abscess to wall off the infection and facilitate bacterial clearance; the number of neutrophils that infiltrate an S. aureus skin infection often correlates with disease outcome. LysM-EGFP mice, which possess the enhanced green fluorescent protein (EGFP) inserted in the Lysozyme M (LysM) promoter region (expressed primarily by neutrophils), when used in conjunction with in vivo whole animal fluorescence imaging (FLI) provide&#160;a means of quantifying neutrophil emigration noninvasively and longitudinally into wounded skin. When combined with a bioluminescent S. aureus strain and sequential in vivo whole animal bioluminescent imaging (BLI), it is possible to longitudinally monitor both the neutrophil recruitment dynamics and in vivo bacterial burden at the site of infection in anesthetized mice from onset of infection to resolution or death. Mice are more resistant to a number of virulence factors produced by S. aureus that facilitate effective colonization and infection in humans. Immunodeficient mice provide a more sensitive animal model to examine persistent S. aureus infections and the ability of therapeutics to boost innate immune responses. Herein, we characterize responses in LysM-EGFP mice that have been bred to MyD88-deficient mice (LysM-EGFP&#215;MyD88-/- mice) along with wild-type LysM-EGFP mice to investigate S. aureus skin wound infection. Multispectral simultaneous detection enabled study of neutrophil recruitment dynamics by using in vivo FLI, bacterial burden by using in vivo BLI, and wound healing longitudinally and noninvasively over time.

A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection

An approach is described for real-time detection of the innate immune response to cutaneous wounding and Staphylococcus aureus infection of mice. By comparing LysM-EGFP mice (which possess fluorescent neutrophils) with a LysM-EGFP crossbred immunodeficient mouse strain, we advance our understanding of infection and the development of approaches to combat infection.

一种评价金黄色葡萄球菌感染先天免疫反应的小鼠模型

Staphylococcus aureus (S. aureus)&#160;infections, including methicillin resistant stains, are an enormous burden on the healthcare system. With incidence ...