The authors would like to thank Trevor Lawley at the Wellcome Trust Sanger Institute for C. difficile R20291 spores and James S. Guy at the North Carolina State University College of Veterinary Medicine for Vero cells, both utilized in this manuscript. Animal histopathology was performed in the LCCC Animal Histopathology Core Facility at the University of North Carolina at Chapel Hill, with special assistance from Traci Raley and Amanda Brown. The LCCC Animal Histopathology Core is supported in part by an NCI Center Core Support Grant (2P30CA016086-40) to the UNC Lineberger Comprehensive Cancer Center. We would also like to thank Vincent Young, Anna Seekatz, Jhansi Leslie, and Cassie Schumacher for helpful discussions on the Vero cell cytotoxicity assay protocol. JAW is funded by the Ruth L. Kirschstein National Research Service Award Research Training grant T32OD011130 by NIH. CMT is funded by the career development award in metabolomics grant K01GM109236 by the NIGMS of the NIH.

<ol>
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The authors have nothing to disclose at this time.

This protocol characterizes the clinical course, including weight loss, bacterial colonization, toxin cytotoxicity, and histopathological changes in the gastrointestinal tract, of antibiotic-treated mice challenged with C. difficile R20291 spores. There are several critical steps within the protocol where attention to detail is essential. Accurate calculation of the C. difficile spore inoculum is critical. This calculation is based on the original C. difficile spore stock enumeration, which sho...

艰难梭菌是一种厌氧，革兰氏阳性，形成孢子的杆菌引起危及生命的腹泻1。 艰难梭菌感染（CDI）与日益增多的人类发病率和死亡率，并导致每年1-4医疗费用相关的超过480十亿$。在2013年，美国疾病控制和预防归类难辨作为一项紧迫抗生素耐药性的风险，这表明它对公众健康的1紧迫的威胁。目前，万古霉素抗生素治疗和甲硝唑被认为是照顾的CDI 5标准。不幸的是，CDI复发成功治疗后用抗生素为高，在20发生-的患者2,5-7 30％。因此，新的治疗剂的发现对这种肠道病原体是必要的。为了评估对难辨梭状芽孢杆菌 ，动物模型近似交流人类疾病治疗需要linically相关的应变。 最初，柯赫氏法则是在1977年用克林霉素治疗的叙利亚仓鼠模型建立8 艰难梭菌 。这种模式是今天仍然利用探讨发病9,10的难辨梭状芽孢杆菌毒素的作用。然而，CDI在仓鼠模型导致高死亡率和不近似慢性阴险疾病表现可与CDI 10,11人看到。根据在研究鼠平台的辅助和试剂可用性，CDI的小鼠模型是相关的。 在2008年，CDI的健壮小鼠模型，通过用在饮用水3天之后克林霉素12腹膜内注射抗生素混合物（卡那霉素，庆大霉素，粘菌素，甲硝唑，万古霉素）治疗的小鼠建立的。这种小鼠呈现易受CDI和严重的结肠炎。依靠ING上施用接种的剂量，可以使用该模型被观察到的范围内的临床症状和杀伤力。因为这个时候，各个抗生素疗法已调查了改变的鼠肠道菌群，降低到艰难梭菌可以定植在胃肠道的点定植抗力（在最佳等人审查。和罗礼＆Young的）13,14。 最近，一种广谱头孢菌素，头孢哌酮，饮用水中的给定的5天或10天重复地呈现小鼠易感CDI 15。由于第三代头孢菌素的管理都与人类的CDI的风险增加，使用头孢哌酮模型更准确地反映自然发生的疾病16。头孢哌酮治疗小鼠容易艰难梭菌受到挑战既艰难梭菌芽孢和范围在临床多种菌株的营养细胞相关性和毒力17。尽管出现了一些利用难辨营养细胞的感染形式的原始研究， 艰难梭菌芽孢被认为是传动装置18的主要方式。 在过去十年中， 艰难梭菌 R20291，一个NAP1 / BI / 027株，已经出现，造成CDI 19,20流行。我们试图确定疾病的临床过程时头孢哌酮处理的小鼠用临床相关和基因-易于处理艰难梭菌菌株，R20291挑战。该协议细节的临床过程，包括体重减轻，细菌定植，毒素的细胞毒性，并与艰难梭菌 R20291孢子攻击的小鼠的胃肠道组织病理学变化。总体而言，这种小鼠模型被证明是CDI近似人类疾病的宝贵的实验平台。此其特征小鼠模型因此可用于评估的影响对临床疾病的改善和关于对艰难梭菌定植抗力的恢复新颖治疗剂。

<table border="0" cellpadding="0" cellspacing="0" width="1037">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:292px;">#62 Perisept Sporidicial Disinfectant Cleaner&#160;</td>
			<td style="width:143px;">SSS Navigator</td>
			<td style="width:119px;">48027</td>
			<td style="width:483px;">This product will require dilution as recommended by the manufacturer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">0.22 &#956;m filter</td>
			<td>Fisherbrand</td>
			<td>09-720-3</td>
			<td>Alternative to filter plate for indivdiual samples tested in the Vero Cell Assay</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">0.25% Trypsin-EDTA</td>
			<td>Gibco</td>
			<td>25200-056</td>
			<td>Needs to be heated in water bath at 37C prior to use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">0.4% Trypan Blue</td>
			<td>Gibco</td>
			<td>15250-061</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1% Peniciilin/Streptomycin</td>
			<td>Gibco</td>
			<td>15070-063</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">10% heat inactivated FBS</td>
			<td>Gibco</td>
			<td>16140-071</td>
			<td>Needs to be heated in water bath at 37C prior to use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1ml plastic syringe&#160;</td>
			<td>BD Medical Supplies</td>
			<td>309628</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1X PBS</td>
			<td>Gibco</td>
			<td>10010-023</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">2 ml Micro Centrifuge Screw Cap</td>
			<td>Corning</td>
			<td>430917</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">96 well cell culture flat bottom plate</td>
			<td>Costar Corning</td>
			<td>CL3595</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">96 well filter plate</td>
			<td>Millipore</td>
			<td>MSGVS2210</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Adhesive Seal</td>
			<td>ThermoScientific</td>
			<td>AB-0558</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:292px;">Bacto Agar</td>
			<td style="width:143px;">Becton Dickinson</td>
			<td style="width:119px;">214010</td>
			<td>Part of TCCFA plates (see below)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:292px;">Bacto Proteose Peptone</td>
			<td style="width:143px;">Becton Dickinson</td>
			<td style="width:119px;">211684</td>
			<td>Part of TCCFA plates (see below)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cefoperazone</td>
			<td>MP Bioworks</td>
			<td>199695</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cefoxitine</td>
			<td>Sigma</td>
			<td>C47856</td>
			<td>Part of TCCFA plates (see below)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Clostridium difficile Antitoxin Kit</td>
			<td>Tech Labs</td>
			<td>T5000</td>
			<td>Used as control for Vero Cell Assay</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Clostridium difficile Toxin A</td>
			<td>List Biological Labs</td>
			<td>152C</td>
			<td>Positive control for Vero Cell Assay</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">D-cycloserine</td>
			<td>Sigma</td>
			<td>C6880</td>
			<td>Part of TCCFA plates (see below)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Distilled Water</td>
			<td>Gibco</td>
			<td>15230</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DMEM 1X Media</td>
			<td>Gibco</td>
			<td>11965-092</td>
			<td>Needs to be heated in water bath at 37C prior to use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fructose</td>
			<td>Fisher</td>
			<td>L95500</td>
			<td>Part of TCCFA plates (see below)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hemocytometer</td>
			<td>Bright-Line, Sigma</td>
			<td>Z359629</td>
			<td></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:292px;">KH2PO4</td>
			<td style="width:143px;">Fisher</td>
			<td style="width:119px;">P285-500</td>
			<td>Part of TCCFA plates (see below)</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:292px;">MgSO4 (anhydrous)</td>
			<td style="width:143px;">Sigma</td>
			<td style="width:119px;">M2643</td>
			<td>Part of TCCFA plates (see below)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:292px;">Millex-GS 0.22 &#956;m filter</td>
			<td style="width:143px;">Millex-GS</td>
			<td style="width:119px;">SLGS033SS</td>
			<td style="width:483px;">Filter for TCCFA plates&#160;</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:292px;">Na2HPO4</td>
			<td style="width:143px;">Sigma</td>
			<td style="width:119px;">S-0876</td>
			<td>Part of TCCFA plates (see below)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NaCl</td>
			<td style="width:143px;">Fisher</td>
			<td style="width:119px;">S640-3</td>
			<td>Part of TCCFA plates (see below)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Number 10 disposable scalpel blade</td>
			<td>Miltex, Inc</td>
			<td>4-410</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PCR Plates</td>
			<td>Fisherbrand</td>
			<td>14230244</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Plastic petri dish</td>
			<td>Kord-Valmark Brand</td>
			<td>2900</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sterile plastic L-shaped cell spreader</td>
			<td>Fisherbrand</td>
			<td>14-665-230</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Syringe Stepper</td>
			<td>Dymax Corporation</td>
			<td>T15469</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Taurocholate</td>
			<td>Sigma</td>
			<td>T4009</td>
			<td>Part of TCCFA plates (see below)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ultrapure distilled water</td>
			<td>Invitrogen</td>
			<td>10977-015</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:292px;">C57BL/6J Mice</td>
			<td style="width:143px;">The Jackson Laboratory</td>
			<td align="right" style="width:119px;">664</td>
			<td style="width:483px;">Mice should be 5-8 weeks of age</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Olympus BX43F light microscope</td>
			<td style="width:143px;">Olympus Life Science</td>
			<td style="width:119px;"></td>
			<td style="width:483px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">DP27 camera</td>
			<td style="width:143px;">Olympus Life Science</td>
			<td style="width:119px;"></td>
			<td style="width:483px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">cellSens Dimension software&#160;</td>
			<td style="width:143px;">Olympus Life Science</td>
			<td style="width:119px;"></td>
			<td style="width:483px;"></td>
		</tr>
	</tbody>
</table>

cefoperazone-treated mouse model of clinically-relevant clostridium difficile strain r20291

Clostridium difficile is an anaerobic, gram-positive, spore-forming enteric pathogen that is associated with increasing morbidity and mortality and consequently poses an urgent threat to public health. Recurrence of a C. difficile infection (CDI) after successful treatment with antibiotics is high, occurring in 20-30% of patients, thus necessitating the discovery of novel therapeutics against this pathogen. Current animal models of CDI result in high mortality rates and thus do not approximate the chronic, insidious disease manifestations seen in humans with CDI. To evaluate therapeutics against C. difficile, a mouse model approximating human disease utilizing a clinically-relevant strain is needed. This protocol outlines the cefoperazone mouse model of CDI using a clinically-relevant and genetically-tractable strain, R20291. Techniques for clinical disease monitoring, C. difficile bacterial enumeration, toxin cytotoxicity, and histopathological changes throughout CDI in a mouse model are detailed in the protocol. Compared to other mouse models of CDI, this model is not uniformly lethal at the dose administered, allowing for the observation of a prolonged clinical course of infection concordant with the human disease. Therefore, this cefoperazone mouse model of CDI proves a valuable experimental platform to assess the effects of novel therapeutics on the amelioration of clinical disease and on the restoration of colonization resistance against C. difficile.

期间的代表性研究中，5周龄的C57BL / 6野生型小鼠用头孢哌酮在其饮用水中（0.5毫克/毫升）预处理5天，并允许一个2天的洗出与普通的饮用水。小鼠用经由在第0天（ 图1A）口服强饲法10 5孢子梭状 R20291的挑战。小鼠14天的CDI体重减轻和临床症状（嗜睡，食欲不振，腹泻，和驼背姿势）进行了监测。 C57BL / 6 WT小鼠艰难梭菌 R20291孢子的挑战导?...

Watch this Scientific Journal Video about Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291 at JoVE.com

Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291

该协议概述了使用临床相关和转听话应变，R20291 艰难梭菌感染（CDI）的头孢哌酮小鼠模型。临床疾病的监测， 艰难梭菌细菌枚举，毒素的细胞毒作用，并在小鼠模型中在整个CDI病理学改变强调在协议中详述。

头孢哌酮治疗小鼠模型的临床相关的<em&gt;艰难梭菌</em&gt;应变R20291

Clostridium difficile is an anaerobic, gram-positive, spore-forming enteric pathogen that is associated with increasing morbidity and mortality and ...

cefoperazone-treated-mouse-model-clinically-relevant-clostridium

Research

JoVE Journal

Immunology and Infection

Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291

12.2K 次观看.  North Carolina State University College of Veterinary Medicine. 该协议概述了使用临床相关和转听话应变，R20291 艰难梭菌感染（CDI）的头孢哌酮小鼠模型。临床疾病的监测， 艰难梭菌细菌枚举，毒素的细胞毒作用，并在小鼠模型中在整个CDI病理学改变强调在协议中详述。 

视频: Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291

Culturing and Maintaining Clostridium difficile in an Anaerobic Environment

Clostridium difficile is a Gram-positive, anaerobic, sporogenic bacterium that is primarily responsible for antibiotic associated diarrhea (AAD) and is a significant nosocomial pathogen. C. difficile is notoriously difficult to isolate and cultivate and is extremely sensitive to even low levels of oxygen in the environment. Here, methods for isolating C. difficile from fecal samples and subsequently culturing C. difficile for preparation of glycerol stocks for long-term storage are presented. Techniques for preparing and enumerating spore stocks in the laboratory for a variety of downstream applications including microscopy and animal studies are also described. These techniques necessitate an anaerobic chamber, which maintains a consistent anaerobic environment to ensure proper conditions for optimal C. difficile growth. We provide protocols for transferring materials in and out of the chamber without causing significant oxygen contamination along with suggestions for regular maintenance required to sustain the appropriate anaerobic environment for efficient and consistent C. difficile cultivation.

Culturing and Maintaining Clostridium difficile in an Anaerobic Environment

Clostridium difficile is a pathogenic bacterium that is a strict anaerobe and causes antibiotic associated diarrhea (AAD). Here, methods for isolating, culturing and maintaining C. difficile vegetative cells and spores are described. These techniques necessitate an anaerobic chamber, which requires regular maintenance to ensure proper conditions for optimal C. difficile cultivation.

培养和维护<em&gt;难辨梭状芽孢杆菌</em&gt;在厌氧环境

Clostridium  difficile is a Gram-positive, anaerobic, sporogenic bacterium  that is primarily responsible for antibiotic associated diarrhea (AAD) and is ...

科研

免疫与感染

Prevention of Heat Stress Adverse Effects in Rats by Bacillus subtilis Strain

This study was designed to evaluate the protective effect of the Bacillus subtilis strain against complications related to heat stress. Thirty-two Sprague-Dawley rats were used in this study. Animals were orally treated twice a day for two days with B. subtilis BSB3 strain or PBS. The next day after the last treatment, each group was divided and two experimental groups (one treated with PBS and one treated with B. subtilis) were placed at 45 oC for 25 min. Two control groups stayed for 25 min at room temperature. All rats were euthanized and different parameters were analyzed in all groups. Adverse effects of heat stress are registered by the decrease of villi height and total mucosal thickness in the intestinal epithelium; translocation of bacteria from the lumen; increased vesiculation of erythrocytes and elevation of the lipopolysaccharides (LPS) level in the blood. The protective efficacy of treatment is evaluated by prevention of these side effects. The protocol was set up for the oral treatment of rats with bacteria for prevention of heat stress complications, but this protocol can be modified and used for other routes of administration and for analysis of different compounds.

Prevention of Heat Stress Adverse Effects in Rats by Bacillus subtilis Strain

We described a protocol for prevention of heat stress effects in rats by oral pre-treatment with beneficial bacteria. This protocol can be modified and used for various routes of administration and for analysis of different compounds.

热火预防应激在大鼠不利影响<em&gt;枯草芽孢杆菌</em&gt;应变

This study was designed to evaluate the protective effect of the Bacillus subtilis strain against complications related to heat stress. Thirty-two ...

A Protocol to Characterize the Morphological Changes of Clostridium difficile in Response to Antibiotic Treatment

Assessment of antibiotic action with new drug development directed towards anaerobic bacteria is difficult and technically demanding. To gain insight into possible MOA, morphologic changes associated with antibiotic exposure can be visualized using scanning electron microscopy (SEM). Integrating SEM imaging with traditional kill curves may improve our insight into drug action and advance the drug development process. To test this premise, kill curves and SEM studies were conducted using drugs with known but different MOA (vancomycin and metronidazole). C. difficile cells (R20291) were grown with or without the presence of antibiotic for up to 48 h. Throughout the 48 h interval, cells were collected at multiple time points to determine antibiotic efficacy and for imaging on the SEM. Consistent with previous reports, vancomycin and metronidazole had significant bactericidal activity following 24 h of treatment as measured by colony-forming unit (CFU) counting. Using SEM imaging we determined that metronidazole had significant effects on cell length (&#62; 50% reduction in cell length for each antibiotic; P&#60; 0.05) compared to controls and vancomycin. While the phenotypic response to drug treatment has not been documented previously in this manner, they are consistent with the drug&#39;s MOA demonstrating the versatility and reliability of the imaging and measurements and the application of this technique for other experimental compounds.

A Protocol to Characterize the Morphological Changes of Clostridium difficile in Response to Antibiotic Treatment

Antibiotic efficacy is most commonly determined by conducting killing kinetic studies and measuring colony forming units (CFUs). By integrating scanning electron microscopy (SEM) with these standard methods, we can distinguish the pharmacological effects of treatment between different antibiotics.

表征形态变化的议定书<em&gt;艰难梭菌</em&gt;应对抗生素治疗

Assessment of antibiotic action with new drug development directed towards anaerobic bacteria is difficult and technically demanding. To gain insight into ...

Influenza A Virus Studies in a Mouse Model of Infection

Influenza viruses cause over 500,000 deaths worldwide1 and are associated with an annual cost of 12 - 14 billion USD in the United States alone considering direct medical and hospitalization expenses and work absenteeism2. Animal models are crucial in Influenza A virus (IAV) studies to evaluate viral pathogenesis, host-pathogen interactions, immune responses, and the efficacy of current and/or novel vaccine approaches as well as antivirals. Mice are an advantageous small animal model because their immune system is evolutionarily similar to that found in humans, they are available from commercial vendors as genetically identical subjects, there are multiple strains that can be exploited to evaluate the genetic basis of infections, and they are relatively inexpensive and easy to manipulate. To recapitulate IAV infection in humans via the airways, mice are first anesthetized prior to intranasal inoculation with infectious IAVs under proper biosafety containment. After infection, the pathogenesis of IAVs is determined by monitoring daily the morbidity (body weight loss) and mortality (survival) rate. In addition, viral pathogenesis can also be evaluated by assessing virus replication in the upper (nasal mucosa) or lower (lungs) respiratory tract of infected mice. Humoral responses upon IAV infection can be rapidly evaluated by non-invasive bleeding and secondary antibody detection assays aimed at detecting the presence of total or neutralizing antibodies. Here, we describe the common methods used to infect mice intranasally (i.n) with IAV and evaluate pathogenesis, humoral immune responses and protection efficacy.

Influenza A viruses (IAVs) are important human respiratory pathogens. To understand the pathogenicity of IAVs and to perform preclinical testing of novel vaccine approaches, animal models mimicking human physiology are required. Here, we describe techniques to evaluate IAV pathogenesis, humoral responses and vaccine efficacy using a mouse model of infection.

流感病毒在小鼠感染模型中的研究

Influenza viruses cause over 500,000 deaths worldwide1 and are associated with an annual cost of 12 - 14 billion USD in the United States alone ...

Replication of the Ordered, Nonredundant Library of Pseudomonas aeruginosa strain PA14 Transposon Insertion Mutants

Pseudomonas aeruginosa is a phenotypically and genotypically diverse and adaptable Gram-negative bacterium ubiquitous in human environments. P. aeruginosa is able to form biofilms, develop antibiotic resistance, produce virulence factors, and rapidly evolve in the course of a chronic infection. Thus P. aeruginosa can cause both acute and chronic, difficult to treat infections, resulting in significant morbidity in certain patient populations. P. aeruginosa strain PA14 is a human clinical isolate with a conserved genome structure that infects a variety of mammalian and nonvertebrate hosts making PA14 an attractive strain for studying this pathogen. In 2006, a nonredundant transposon insertion mutant library containing 5,459 mutants corresponding to 4,596 predicted PA14 genes was generated. Since then, distribution of the PA14 library has allowed the research community to better understand the function of individual genes and complex pathways of P. aeruginosa. Maintenance of library integrity through the replication process requires proper handling and precise techniques. To that end, this manuscript presents protocols that describe in detail the steps involved in library replication, library quality control and proper storage of individual mutants.

Replication of the Ordered, Nonredundant Library of Pseudomonas aeruginosa strain PA14 Transposon Insertion Mutants

Pseudomonas aeruginosa infection causes significant morbidity in vulnerable hosts. The nonredundant transposon insertion mutant library of P. aeruginosa strain PA14, designated as PA14NR Set, facilitates analysis of gene functionality in numerous processes. Presented here is a protocol to generate high-quality copies of the PA14NR Set mutant library.

复制的有序, 非冗余图书馆的铜绿假单胞菌应变 PA14 座子插入突变体

Pseudomonas aeruginosa is a phenotypically and genotypically diverse and adaptable Gram-negative bacterium ubiquitous in human environments. P. aeruginosa ...

A Protein Microarray Assay for Serological Determination of Antigen-specific Antibody Responses Following Clostridium difficile Infection

We provide a detailed overview of a novel high-throughput protein microarray assay for the determination of anti-Clostridium difficile antibody levels in human sera and in separate preparations of polyclonal intravenous immunoglobulin (IVIg). The protocol describes the methodological steps involved in sample preparation, printing of arrays, assay procedure, and data analysis. In addition, this protocol could be further developed to incorporate diverse clinical samples including plasma and cell culture supernatants. We show how protein microarray can be used to determine a combination of isotype (IgG, IgA, IgM), subclass (IgG1, IgG2, IgG3, IgG4, IgA1, IgA2), and strain-specific antibodies to highly purified whole C. difficile toxins A and B (toxinotype 0, strain VPI 10463, ribotype 087), toxin B from a C. difficile toxin-B-only expressing strain (CCUG 20309), a precursor form of a B fragment of binary toxin, pCDTb, ribotype-specific whole surface layer proteins (SLPs; 001, 002, 027), and control proteins (tetanus toxoid and Candida albicans). During the experiment, microarrays are probed with sera from individuals with C. difficile infection (CDI), individuals with cystic fibrosis (CF) without diarrhea, healthy controls (HC), and from individuals pre- and post-IVIg therapy for the treatment of CDI, combined immunodeficiency disorder, and chronic inflammatory demyelinating polyradiculopathy. We encounter significant differences in toxin neutralization efficacies and multi-isotype specific antibody levels between patient groups, commercial preparations of IVIg, and sera before and following IVIg administration. Also, there is a significant correlation between microarray and enzyme-linked immunosorbent assay (ELISA) for antitoxin IgG levels in serum samples. These results suggest that microarray could become a promising tool for profiling antibody responses to C.difficile antigens in vaccinated or infected humans. With further refinement of antigen panels and a reduction in production costs, we anticipate that microarray technology may help optimize and select the most clinically useful immunotherapies for C. difficile infection in a patient-specific manner.

A Protein Microarray Assay for Serological Determination of Antigen-specific Antibody Responses Following Clostridium difficile Infection

This article describes a simple protein microarray method for profiling humoral immune responses to a 7-plex panel of highly purified Clostridium difficile antigens in human sera. The protocol can be extended for the determination of specific antibody responses in preparations of polyclonal intravenous immunoglobulin.

检测梭菌感染后抗原特异性抗体应答的蛋白微阵列测定方法

We provide a detailed overview of a novel high-throughput protein microarray assay for the determination of anti-Clostridium difficile antibody levels in ...

A Purification and In Vitro Activity Assay for a (p)ppGpp Synthetase from Clostridium difficile

Kinase and pyrophosphokinase enzymes transfer the gamma phosphate or the beta-gamma pyrophosphate moiety from nucleotide triphosphate precursors to substrates to create phosphorylated products. The use of &#947;-32-P labeled NTP precursors allows simultaneous monitoring of substrate utilization and product formation by radiography. Thin layer chromatography (TLC) on cellulose plates allows rapid separation and sensitive quantification of substrate and product. We present a method for utilizing the thin-layer chromatography to assay the pyrophosphokinase activity of a purified (p)ppGpp synthetase. This method has previously been used to characterize the activity of cyclic nucleotide and dinucleotide synthetases and is broadly suitable for characterizing the activity of any enzyme that hydrolyzes a nucleotide triphosphate bond or transfers a terminal phosphate from a phosphate donor to another molecule.

A Purification and In Vitro Activity Assay for a pppGpp Synthetase from Clostridium difficile

Here, we describe a method for purifying histidine-tagged pyrophosphokinase enzymes and utilizing thin layer chromatography of radiolabelled substrates and products to assay for the enzymatic activity in vitro. The enzyme activity assay is broadly applicable to any kinase, nucleotide cyclase, or phosphor-transfer reaction whose mechanism includes nucleotide triphosphate hydrolysis.

艰难梭菌(p) pppp 合成酶的纯化及体外活性测定

Kinase and pyrophosphokinase enzymes transfer the gamma phosphate or the beta-gamma pyrophosphate moiety from nucleotide triphosphate precursors to ...

A Controlled Mouse Model for Neonatal Polymicrobial Sepsis

Neonatal sepsis remains a global burden. A preclinical model to screen effective prophylactic or therapeutic interventions is needed. Neonatal mouse polymicrobial sepsis can be induced by injecting cecal slurry intraperitoneally into day of life 7 mice and monitoring them for the following week. Presented here are the detailed steps necessary for the implementation of this neonatal sepsis model. This includes making a homogeneous cecal slurry stock, diluting it to a weight- and litter-adjusted dose, an outline of the monitoring schedule, and a definition of observed health categories used to define humane endpoints. The generation of a homogeneous cecal slurry stock from pooled donors allows for the administration into many litters over time, reducing the variation between donors, and preventing the use of potentially toxic glycerol. The monitoring strategy used allows for the anticipation of survival outcome and the identification of mice that would later progress to death, allowing for an earlier identification of the humane endpoint. Two main behavioral features are used to define the health scores, namely, the ability of the neonatal mice to right themselves when placed on their back and their level of mobility. These criteria could potentially be applied to address humane endpoints in other studies of neonatal disease in mice, as long as a pilot study is performed to confirm accuracy. In conclusion, this approach provides a standardized method to model newborn sepsis in mice, while providing resources to assess animal welfare used to define early humane endpoints for challenged animals.

This protocol provides the necessary steps to establish and evaluate neonatal sepsis in 7-day-old mice.

新生儿多药脓毒症的对照小鼠模型

Neonatal sepsis remains a global burden. A preclinical model to screen effective prophylactic or therapeutic interventions is needed. Neonatal mouse ...

Measurement of Pulse Propagation Velocity, Distensibility and Strain in an Abdominal Aortic Aneurysm Mouse Model

An abdominal aortic aneurysm (AAA) is defined as a localized dilation of the abdominal aorta that exceeds the maximal intraluminal diameter (MILD) by 1.5 times of its original size. Clinical and experimental studies have shown that small aneurysms may rupture, while a subpopulation of large aneurysms may remain stable. Thus, in addition to the measurement of intraluminal diameter of the aorta, knowledge of structural traits of the vessel wall may provide important information to assess the stability of the AAA. Aortic stiffening has recently emerged as a reliable tool to determine early changes in the vascular wall. Pulse propagation velocity (PPV) along with the distensibility and radial strain are highly useful ultrasound-based methods relevant for assessing aortic stiffness. The primary purpose of this protocol is to provide a comprehensive technique for the use of ultrasound imaging system to acquire images and analyze the structural and functional properties of the aorta as determined by MILD, PPV, distensibility and radial strain.

This manuscript describes a detailed protocol for using high frequency ultrasound imaging to measure luminal diameter, pulse propagation velocity, distensibility and radial strain on a mouse model of abdominal aortic aneurysm.

腹部主动脉瘤小鼠模型中脉冲传播速度、失散性和应变的测量

An abdominal aortic aneurysm (AAA) is defined as a localized dilation of the abdominal aorta that exceeds the maximal intraluminal diameter (MILD) by 1.5 ...

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

Streptococcus pneumoniae serotype 1 remains a huge problem in low-and-middle income countries, particularly in sub-Saharan Africa. Despite its importance, studies in this serotype have been hindered by the lack of genetic tools to modify it. In this study, we describe a method to genetically modify a serotype 1 clinical isolate (strain 519/43). Interestingly, this was achieved by exploiting the Pneumococcus&#8217; ability to naturally acquire DNA. However, unlike most pneumococci, the use of linear DNA was not successful; to mutate this important strain, a suicide plasmid had to be used. This methodology has provided the means for a deeper understanding of this elusive serotype, both in terms of its biology and pathogenicity. To validate the method, the major known pneumococcal toxin, pneumolysin, was mutated because it has a well-known and easy to follow phenotype. We showed that the mutant, as expected, lost its ability to lyse red blood cells. By being able to mutate an important gene in the serotype of interest, we were able to observe different phenotypes for loss of function mutants upon intraperitoneal and intranasal infections from the ones observed for other serotypes. In summary, this study proves that strain 519/43 (serotype 1) can be genetically modified.

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

Here, we describe a S. pneumoniae serotype 1 strain 519/43 that can be genetically modified by using its ability to naturally acquire DNA and a suicide-plasmid. As proof of principle, an isogenic mutant in the pneumolysin (ply) gene was made.

在血清型 1 型肺炎链球菌 菌株 519/43 中构建突变体

Streptococcus pneumoniae serotype 1 remains a huge problem in low-and-middle income countries, particularly in sub-Saharan Africa. Despite its importance, ...

头孢哌酮治疗小鼠模型的临床相关的

摘要

探索更多视频

此视频中的章节

培养和维护

热火预防应激在大鼠不利影响

表征形态变化的议定书

流感病毒在小鼠感染模型中的研究

复制的有序, 非冗余图书馆的铜绿假单胞菌应变 PA14 座子插入突变体

检测梭菌感染后抗原特异性抗体应答的蛋白微阵列测定方法

艰难梭菌(p) pppp 合成酶的纯化及体外活性测定

新生儿多药脓毒症的对照小鼠模型

腹部主动脉瘤小鼠模型中脉冲传播速度、失散性和应变的测量

在血清型 1 型肺炎链球菌菌株 519/43 中构建突变体

头孢哌酮治疗小鼠模型的临床相关的

摘要

探索更多视频

此视频中的章节

培养和维护

热火预防应激在大鼠不利影响

表征形态变化的议定书

流感病毒在小鼠感染模型中的研究

复制的有序, 非冗余图书馆的铜绿假单胞菌应变 PA14 座子插入突变体

检测梭菌感染后抗原特异性抗体应答的蛋白微阵列测定方法

艰难梭菌(p) pppp 合成酶的纯化及体外活性测定

新生儿多药脓毒症的对照小鼠模型

腹部主动脉瘤小鼠模型中脉冲传播速度、失散性和应变的测量

在血清型 1 型肺炎链球菌 菌株 519/43 中构建突变体

在血清型 1 型肺炎链球菌菌株 519/43 中构建突变体