我们要感谢脑膜炎信托基金和MRC为这项工作提供资金。

1. 通过SOE-PCR23 生成突变扩增子和扩增壮观霉素盒
<ol><li>首先进行PCR以扩增菌株519/43中层基因侧翼区域的同源臂（分别为ply 5'（488 bp）和ply3'（715 bp））。Use primers plyFw1_NOTI （TTT GCGGCCGCCAGTAAATGACTTTATACTAGCTATG）， ply5'R1_BamHI （CGAAATATAGACCAAAGGACGC GGATCC AGAACCAAACTTGACCTTGA）， ply3'F1_BamHI （TCAAGGTCAAGTTTGGTTCTGGATCC GCGTCCTTTGGTTTCG） 和plyRv2_NotI （TTTGCGGCCGCCATTTTCTACCTTATCCTCTACC）.</li>
	<li>对ply5'使用以下PCR条件:在94°C下变性60秒，步骤2:在94°C下变性30秒，步骤3:在58°C下退火30秒，步骤4:在72°C下延伸30秒，步骤5:返回步骤2并重复35个循环，步骤6:在72°C下最终延伸30秒。<ol><li>对 ply3' 使用相同的 PCR 条件，但步骤 4 和步骤 6 的延长时间应为 60 秒。</li>
	</ol></li>
	<li>通过凝胶电泳分析PCR产物并从凝胶中切除扩增子。</li>
	<li>按照制造商说明（材料表）中描述的方案纯化PCR扩增子。</li>
	<li>在SOE-PCR中使用等摩尔量的两个同源臂作为模板。使用引物plyFw1_NOTI （TTT GCGGCCGCCAGTAAATGACTTTATACTAGCTATG）和plyRv2_NotI（TTTGCGGCCGCCATTTTCTACCTTATCCTCTACC）的引物融合两个扩增子。</li>
	<li>使用以下SOE-PCR条件（步骤1:在94°C变性2分钟，步骤2:在94°C变性30秒，步骤3:退火58°C退火30秒，步骤4:在68°C下延伸60秒，步骤5:返回步骤2并重复25个循环，步骤6:最终在68°C下延伸90秒）。</li>
	<li>通过凝胶电泳分析SOE-PCR产物。使用凝胶提取试剂盒将其从凝胶中切除，并按照提供的说明进行操作。</li>
	<li>使用以下PCR条件扩增质粒pR412中的大观霉素盒:步骤1:在94°C变性60秒，步骤2:在94°C变性30秒，步骤3:在55°C下退火30秒，步骤4:在68°C下延伸60秒，步骤5:返回步骤2并重复25个循环， 步骤6:在68°C下最终延伸60秒。<ol><li>使用引物BamHI_SP2F2（GGATCC CTA GAA CTA GTG GAT CCC CC）和BamHI_SP2R2（GGATCC AAT TCT GCA GAT TTT AC ATG ATC）。质粒pR412购自Marc PrudHomme博士（法国国家科学研究中心保罗·萨巴蒂埃图卢兹大学）。</li>
	</ol></li>
	<li>通过凝胶电泳分析PCR扩增子。如上所述切除和纯化所得的PCR扩增子。</li>
</ol>2. 质粒pSD1的生成和 大肠杆菌 Dh5α的化学转化
<ol><li>按照pGEMT简易系统I制造商说明（材料表）进行连接。在微量离心管中，加入 5 μL 2x 连接缓冲液、1 μL pGEMTeasy、2 μL ply_SOE产物、1 μL T4 DNA 连接酶和水，总体积为 20 μL。在4°C孵育过夜。 生成质粒pSD1。</li>
	<li>用pSD1转化化学含量 的大肠杆菌 Dh5α。首先将 50 μL 化学含量大 肠杆菌 Dh5α 与 3 μL pSD1 连接反应在冰上孵育 15 分钟。然后继续将细胞暴露于热冲击（42°C，30秒）。将细胞放在冰上2分钟。</li>
	<li>从冰上取出细胞并加入 350 μL S.O.C 培养基。将培养物在37°C，120rpm下孵育2小时。</li>
	<li>将转化接种在补充有 0.4 mM IPTG、0.24 mg/mL X-Gal 用于蓝/白选择和 100 μg/mL 氨苄青霉素的 Luria Bertani 琼脂 （LBA） 上，以确保平板中生长的所有菌落都具有质粒骨架。白色菌落含有pSD1。</li>
	<li>挑选三个白色菌落，在 10 mL LB 中建立过夜生长，并补充有 100 μg/mL 氨苄青霉素。将培养物在37°C振荡孵育过夜。</li>
	<li>第二天以3，082× g 离心培养物，并使用沉淀进行质粒提取。</li>
</ol>3. 质粒DNA提取、pSD1和壮观霉素基因的限制性酶切及pSD2组装
<ol><li>按照商业试剂盒随附的说明提取质粒DNA（材料表）。</li>
	<li>为先前扩增和纯化的pSD1质粒和大观霉素盒设置BamHI限制性酶切。使用以下条件和数量如 表1所示。</li>
	<li>将限制性酶切反应和对照在37°C孵育3小时。</li>
	<li>通过电泳分析限制性内切物，切除条带并按照商业试剂盒提供的说明进行纯化（材料表）。</li>
	<li>接下来，按照制造商说明（材料表）使用BamHI-消化的pSD1和大观霉素（来自步骤3.2）制备连接反应。在微量离心管中，加入以下反应组分:5 μL 2x 连接缓冲液、2 μL pSD1、2 μL 大观霉素盒、1 μL T4 DNA 连接酶，并在 4 °C 下孵育过夜。 生成质粒pSD2。</li>
	<li>如步骤2.2中所述，将质粒pSD2转化为化学感受态大 肠杆菌 Dh5α。</li>
	<li>根据携带质粒pSD2的转化体在补充有100μg/mL大观霉素和氨苄青霉素的LBA中生长的能力来选择转化体。</li>
	<li>按照上述说明并按照制造商的说明（μL）进行质粒DNA提取（pSD2）。</li>
</ol>4. 肺炎链球菌 菌株的转化 519/43
<ol><li>在BHI中制备肺炎链球菌519/43的过夜培养物，并使其在37°C，5%CO2下静态生长。</li>
	<li>第二天，将培养物在 10 mL 新鲜 BHI 肉汤中以 1:50 和 1:100 稀释。在37°C下静态孵育培养物，直到OD595nm 在0.05和0.1之间（最佳DNA采集接近0.1 OD）。</li>
	<li>一旦OD达到0.1，取860μL并转移到微量离心管中。在同一微量离心管中，添加:100 μL 100 mM NaOH、10 μL 20% （w/v） BSA、10 μL 100 mM CaCl 2、2 μL 50 ng/mL CSP124 和 500 ng pSD2。</li>
	<li>将反应在37°C下静态孵育3小时。</li>
	<li>将 330 μL 板铺在补充有 100 μg/mL 壮观霉素的 5% 血琼脂平板 （BA） 上，在 3 个孵育小时内每小时一次。</li>
	<li>将板在37°C，5%CO2下孵育过夜。将大观霉素耐药菌落贴在补充有 100 μg/mL 大观霉素的另一块 BA 平板上以及补充有 100 μg/mL 氨苄西林的 BA 平板上。在上述条件下孵育两组板过夜。氨苄西林板用于测试质粒骨架的存在。</li>
	<li>使用NOTI plyFw1_（TTT GCGGCCGCCAGTAAATGACTTTATACTAGCTATGG） 和SPEC_REV（TAATTCCTCTAAGTCATAATTTCCG）的引物通过PCR确认大观霉素盒的存在。使用附着在突变区域外的引物plySCN1（CCAATGGAAATCGCTAGGCAAGAGATAA）和plySCN2（ATTACTTAGTCCAACCACGGCTGAT）通过PCR确认突变。</li>
	<li>通过使用引物plySCN1（CCAATGGAAATCGCTAGGCAAGAGATAA），plySCN2（ATTACTTAGTCCAACCACGGCTGAT）以及引物及其在大观霉素盒sqr1（CCTGATCCAACATGTAGTAGTACC）sqf2（CGTAGTTATCTTGGAGAGAATA）spec_sqf1（GGTACTTACATGTGTGGATCAGG）和spec_sqr2 TATTCTCTCCAAGATAACTACG中的引物测序，确认基因组正确位置的整合。</li>
</ol>

<ol>
	<li>Bentley, S. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+Analysis+of+the+Capsular+Biosynthetic+Locus+from+All+90+Pneumococcal+Serotypes.">Genetic Analysis of the Capsular Biosynthetic Locus from All 90 Pneumococcal Serotypes.</a> PLoS Genetics. 2 (3), 31 (2006).</li><li>Calix, J. J., Nahm, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+pneumococcal+serotype,+11E,+has+a+variably+inactivated+wcjE+gene.">A new pneumococcal serotype, 11E, has a variably inactivated wcjE gene.</a> The Journal of Infectious Diseases. 202 (1), 29-38 (2010).</li><li>Park, I. H., Pritchard, D. G., Cartee, R., Brandao, A., Brandileone, M. C. C., Nahm, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Discovery+of+a+New+Capsular+Serotype+(6C)+within+Serogroup+6+of+Streptococcus+pneumoniae.">Discovery of a New Capsular Serotype (6C) within Serogroup 6 of Streptococcus pneumoniae.</a> Journal of Clinical Microbiology. 45 (4), 1225-1233 (2007).</li><li>Jin, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=First+Report+of+Putative+Streptococcus+pneumoniae+Serotype+6D+among+Nasopharyngeal+Isolates+from+Fijian+Children.">First Report of Putative Streptococcus pneumoniae Serotype 6D among Nasopharyngeal Isolates from Fijian Children.</a> The Journal of Infectious Diseases. 200 (9), 1375-1380 (2009).</li><li>Oliver, M. B., vander Linden, M. P. G., K&#252;ntzel, S. A., Saad, J. S., Nahm, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Discovery+of+Streptococcus+pneumoniae+Serotype+6+Variants+with+Glycosyltransferases+Synthesizing+Two+Differing+Repeating+Units.">Discovery of Streptococcus pneumoniae Serotype 6 Variants with Glycosyltransferases Synthesizing Two Differing Repeating Units.</a> Journal of Biological Chemistry. 288 (36), 25976-25985 (2013).</li><li>Calix, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serological+Characterization+of+Two+Capsule+Subtypes+among+Streptococcus+pneumoniae+Serotype+20+Strains.">Serological Characterization of Two Capsule Subtypes among Streptococcus pneumoniae Serotype 20 Strains.</a> Journal of Biological Chemistry. 287 (33), 27885-27894 (2012).</li><li>Park, I. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=and+Serological+Characterization+of+a+New+Pneumococcal+Serotype,+6H,+and+Generation+of+a+Pneumococcal+Strain+Producing+Three+Different+Capsular+Repeat+Units.">and Serological Characterization of a New Pneumococcal Serotype, 6H, and Generation of a Pneumococcal Strain Producing Three Different Capsular Repeat Units.</a> Clinical and Vaccine Immunology. 22 (3), 313-318 (2015).</li><li>O'Brien, K. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Burden+of+disease+caused+by+Streptococcus+pneumoniae+in+children+younger+than+5+years:+global+estimates.">Burden of disease caused by Streptococcus pneumoniae in children younger than 5 years: global estimates.</a> The Lancet. 374 (9693), 893-902 (2009).</li><li>Henriques-Normark, B., Tuomanen, E. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Pneumococcus:+Epidemiology,+Microbiology,+and+Pathogenesis.">The Pneumococcus: Epidemiology, Microbiology, and Pathogenesis.</a> Cold Spring Harbor Perspectives in Medicine. 3 (7), 010215 (2013).</li><li>Leimkugel, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Outbreak+of+Serotype+1+Streptococcus+pneumoniae+Meningitis+in+Northern+Ghana+with+Features+That+Are+Characteristic+of+Neisseria+meningitidis+Meningitis+Epidemics.">An Outbreak of Serotype 1 Streptococcus pneumoniae Meningitis in Northern Ghana with Features That Are Characteristic of Neisseria meningitidis Meningitis Epidemics.</a> The Journal of Infectious Diseases. 192 (2), 192-199 (2005).</li><li>Yaro, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiological+and+Molecular+Characteristics+of+a+Highly+Lethal+Pneumococcal+Meningitis+Epidemic+in+Burkina+Faso.">Epidemiological and Molecular Characteristics of a Highly Lethal Pneumococcal Meningitis Epidemic in Burkina Faso.</a> Clinical Infectious Diseases. 43 (6), 693-700 (2006).</li><li>Antonio, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+epidemiology+of+pneumococci+obtained+from+Gambian+children+aged+2-29+months+with+invasive+pneumococcal+disease+during+a+trial+of+a+9-valent+pneumococcal+conjugate+vaccine.">Molecular epidemiology of pneumococci obtained from Gambian children aged 2-29 months with invasive pneumococcal disease during a trial of a 9-valent pneumococcal conjugate vaccine.</a> BMC Infectious Diseases. 8 (1), 81 (2008).</li><li>Kwambana-Adams, B. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+outbreak+of+pneumococcal+meningitis+among+older+children+(&#8805;5+years)+and+adults+after+the+implementation+of+an+infant+vaccination+programme+with+the+13-valent+pneumococcal+conjugate+vaccine+in+Ghana.">An outbreak of pneumococcal meningitis among older children (&#8805;5 years) and adults after the implementation of an infant vaccination programme with the 13-valent pneumococcal conjugate vaccine in Ghana.</a> BMC Infectious Diseases. 16 (1), 575 (2016).</li><li>Antonio, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seasonality+and+outbreak+of+a+predominant+Streptococcus+pneumoniae+serotype+1+clone+from+The+Gambia:+Expansion+of+ST217+hypervirulent+clonal+complex+in+West+Africa.">Seasonality and outbreak of a predominant Streptococcus pneumoniae serotype 1 clone from The Gambia: Expansion of ST217 hypervirulent clonal complex in West Africa.</a> BMC Microbiology. 8 (1), 198 (2008).</li><li>Staples, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+characterization+of+an+Australian+serotype+1+Streptococcus+pneumoniae+outbreak.">Molecular characterization of an Australian serotype 1 Streptococcus pneumoniae outbreak.</a> Epidemiology and Infection. 143 (2), 325-333 (2015).</li><li>Gessner, B. D., Mueller, J. E., Yaro, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=African+meningitis+belt+pneumococcal+disease+epidemiology+indicates+a+need+for+an+effective+serotype+1+containing+vaccine,+including+for+older+children+and+adults.">African meningitis belt pneumococcal disease epidemiology indicates a need for an effective serotype 1 containing vaccine, including for older children and adults.</a> BMC Infectious Diseases. 10 (1), 22 (2010).</li><li>Hill, P. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nasopharyngeal+carriage+of+Streptococcus+pneumoniae+in+Gambian+infants:+a+longitudinal+study.">Nasopharyngeal carriage of Streptococcus pneumoniae in Gambian infants: a longitudinal study.</a> Clinical Infectious Diseases. 46 (6), 807-814 (2008).</li><li>Ebruke, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal+changes+in+nasopharyngeal+carriage+of+Streptococcus+pneumoniae+serotype+1+genotypes+in+healthy+Gambians+before+and+after+the+7-valent+pneumococcal+conjugate+vaccine.">Temporal changes in nasopharyngeal carriage of Streptococcus pneumoniae serotype 1 genotypes in healthy Gambians before and after the 7-valent pneumococcal conjugate vaccine.</a> PeerJ. 3, 90 (2015).</li><li>Adegbola, R. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serotype+and+antimicrobial+susceptibility+patterns+of+isolates+of+Streptococcus+pneumoniae+causing+invasive+disease+in+The+Gambia+1996-2003.">Serotype and antimicrobial susceptibility patterns of isolates of Streptococcus pneumoniae causing invasive disease in The Gambia 1996-2003.</a> Tropical Medicine and International Health. 11 (7), 1128-1135 (2006).</li><li>Marks, L. R., Reddinger, R. M., Hakansson, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+Levels+of+Genetic+Recombination+during+Nasopharyngeal+Carriage+and+Biofilm+Formation+in+Streptococcus+pneumoniae.">High Levels of Genetic Recombination during Nasopharyngeal Carriage and Biofilm Formation in Streptococcus pneumoniae.</a> mBio. 3 (5), (2012).</li><li>Ritchie, N. D., Mitchell, T. J., Evans, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+is+different+about+serotype+1+pneumococci.">What is different about serotype 1 pneumococci.</a> Future Microbiology. 7 (1), 33-46 (2012).</li><li>Harvey, R. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+variable+region+of+pneumococcal+pathogenicity+island+1+is+responsible+for+unusually+high+virulence+of+a+serotype+1+isolate.">The variable region of pneumococcal pathogenicity island 1 is responsible for unusually high virulence of a serotype 1 isolate.</a> Infection and Immunity. 84 (3), 822-832 (2016).</li><li>Horton, R. M., Cai, Z. L., Ho, S. N., Pease, L. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+splicing+by+overlap+extension:+tailor-made+genes+using+the+polymerase+chain+reaction.">Gene splicing by overlap extension: tailor-made genes using the polymerase chain reaction.</a> BioTechniques. 8 (5), 528-535 (1990).</li><li>Alioing, G., Granadel, C., Morrison, D. A., Claverys, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Competence+pheromone,+oligopeptide+permease,+and+induction+of+competence+in+Streptococcus+pneumoniae.">Competence pheromone, oligopeptide permease, and induction of competence in Streptococcus pneumoniae.</a> Molecular Microbiology. 21 (3), 471-478 (1996).</li><li>Lund, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Enumeration and description of the strains belonging to the State Serum Institute, Copenhagen Denmark. , (1951).</li><li>Barany, F., Tomasz, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+transformation+of+Streptococcus+pneumoniae+by+heterologous+plasmid+deoxyribonucleic+acid.">Genetic transformation of Streptococcus pneumoniae by heterologous plasmid deoxyribonucleic acid.</a> Journal of Bacteriology. 144 (2), 698-709 (1980).</li><li>Terra, V. S., Homer, K. A., Rao, S. G., Andrew, P. W., Yesilkaya, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+novel+&#946;-galactosidase+activity+that+contributes+to+glycoprotein+degradation+and+virulence+in+Streptococcus+pneumoniae.">Characterization of novel &#946;-galactosidase activity that contributes to glycoprotein degradation and virulence in Streptococcus pneumoniae.</a> Infection and Immunity. 78 (1), (2010).</li><li>Terra, V. S., Zhi, X., Kahya, H. F., Andrew, P. W., Yesilkaya, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pneumococcal+6-phospho-&#946;-glucosidase+(BglA3)+is+involved+in+virulence+and+nutrient+metabolism.">Pneumococcal 6-phospho-&#946;-glucosidase (BglA3) is involved in virulence and nutrient metabolism.</a> Infection and Immunity. 84 (1), (2015).</li><li>Harvey, R. M., Ogunniyi, A. D., Chen, A. Y., Paton, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pneumolysin+with+Low+Hemolytic+Activity+Confers+an+Early+Growth+Advantage+to+Streptococcus+pneumoniae+in+the+Blood.">Pneumolysin with Low Hemolytic Activity Confers an Early Growth Advantage to Streptococcus pneumoniae in the Blood.</a> Infection and Immunity. 79 (10), 4122 (2011).</li><li>Terra, V. S., Plumptre, C. D., Wall, E. C., Brown, J. S., Wren, B. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Construction+of+a+pneumolysin+deficient+mutant+in+Streptococcus+pneumoniae+serotype+1+strain+519/43+and+phenotypic+characterisation.">Construction of a pneumolysin deficient mutant in Streptococcus pneumoniae serotype 1 strain 519/43 and phenotypic characterisation.</a> Microbial Pathogenesis. 141, 103999 (2020).</li></ol>

作者没有什么可透露的。

肺炎链球菌，特别是血清1型，仍然是引起侵袭性肺炎球菌疾病和脑膜炎的全球威胁。尽管在非洲引入了各种疫苗，可以预防血清型1，但这种血清型仍然能够引起导致高发病率和死亡率的暴发13。由于其临床相关性，遗传操纵这种血清型的能力至关重要。本研究中描述的方法允许对该血清型中的代表性菌株进行遗传操作。侵袭性菌株 519/43 （ST5316），一种来自丹麦脑膜炎患?...

肺炎链球菌（肺炎链球菌，肺炎球菌）是全球发病和死亡的主要原因之一。直到最近，已经发现了近100种肺炎链球菌血清型1，2，3，4，5，6，7。侵袭性肺炎球菌病（IPD）每年造成约70万人死亡，其中5岁以下儿童8。肺炎链球菌是全球细菌性肺炎、中耳炎、脑膜炎和败血症的主要原因9。
在非洲脑膜炎地带，血清型1是脑膜炎暴发的原因，其中序列型（ST）ST217是一种毒性极强的序列类型，占主导地位10，11，12，13，14，15。它在脑膜炎病理学中的重要性被比作非洲脑膜炎带脑膜炎奈瑟菌的重要性16。血清 1 型通常是 IPD 的主要原因;然而，它在运输中很少发现。事实上，在冈比亚，这种血清型占所有侵袭性疾病的20%，但仅在0.5%的健康携带者中发现14，17，18，19。感受态肺炎球菌的遗传交换和重组通常发生在携带中，而不是在侵袭性疾病中发生20。此外，血清型 1 已被证明是肺炎球菌中描述的最短携带率之一（仅 9 天）。因此，有人提出这种血清型的重组率可能比其他血清型低得多21。
有必要进行深入研究，以了解血清型1菌株携带率低的原因及其在撒哈拉以南非洲侵袭性疾病中的重要性。
在这里，我们报告了一种协议，该协议允许特定血清型1菌株的全基因组诱变，519/43。这种菌株可以很容易地获得新的DNA并将其重组到其基因组中。这种方法还不是菌株间，但在519/43背景下完成时非常有效（其他靶标已经突变，手稿正在准备中）。通过简单地使用519/43菌株，并利用其自然能力，以及替代提供外源DNA的方式，我们能够突变该血清型1菌株中的肺溶血素基因（ply）。该方法代表了Harvey等人提出的方法的改进22 ，因为它是一步完成的，无需通过不同的血清型传代DNA。然而，由于菌株间变异性，没有一种方法适用于所有菌株。突变特定基因并观察其影响的能力将使人们深入了解血清型 1型肺炎链球菌 菌株，并将为这些菌株在撒哈拉以南非洲脑膜炎中的作用提供答案。

<table><tbody><tr><td>AccuPrime &lt;em&gt;Pfx&lt;/em&gt; DNA polymerase</td><td>Invitrogen</td><td>12344024</td><td>Used for amplification of the fragments</td></tr><tr><td>Ampicillin sodium salt</td><td>Sigma Aldrich</td><td>A9518</td><td>Used for bacterial selection on stage 1(pSD1)</td></tr><tr><td>Blood Agar Base</td><td>Oxoid</td><td>CM0055</td><td>Used to plate &lt;em&gt;S. pneumoniae&lt;/em&gt; transformants</td></tr><tr><td>Bovine Serum Albumine</td><td>sigma</td><td>55470</td><td>used for &lt;em&gt;S. pneumoniae&lt;/em&gt; Transformation</td></tr><tr><td>Brain Heart Infusion</td><td>Oxoid</td><td>CM1135</td><td>used to grow &lt;em&gt;S. pneumoniae&lt;/em&gt; cells</td></tr><tr><td>Calcium Chloride Cacl&lt;sub&gt;2&lt;/sub&gt;</td><td>Sigma</td><td>449709</td><td>used for &lt;em&gt;S. pneumoniae&lt;/em&gt; Transformation</td></tr><tr><td>Competence stimulating peptide 1</td><td>AnaSpec</td><td>AS-63779</td><td>used for &lt;em&gt;S. pneumoniae&lt;/em&gt; Transformation</td></tr><tr><td>Luria Broth Agar</td><td>Gibco</td><td>22700025</td><td>used for plating and selection of pSD1 and pSD2</td></tr><tr><td>Luria Broth Base (Miller&#039;s formulation)</td><td>Gibco</td><td>12795027</td><td>used for plating and selection of pSD1 and pSD2</td></tr><tr><td>Monarch Gel Extraction Kit</td><td>NEB</td><td>T1020S</td><td>Used to extract the bands from the DNA gel</td></tr><tr><td>Monarch Plasmid Miniprep Kit</td><td>NEB</td><td>T1010S</td><td>Used to extract plasmid from the cells</td></tr><tr><td>pGEM T-easy</td><td>Promega</td><td>A1360</td><td>used as suicide plasmid</td></tr><tr><td>S.O.C.</td><td>Invitrogen</td><td>15544034</td><td>used for recovery of cells after transformation</td></tr><tr><td>Sodium Hydroxide (NaOH)</td><td>Sigma</td><td>S0899</td><td>used for &lt;em&gt;S.pneumoniae&lt;/em&gt; Transformation</td></tr><tr><td>Spectinomycin Hydrochloride</td><td>SigmaAldrich</td><td>PHR1426</td><td>Used for bacterial selection</td></tr><tr><td>Subcloning Efficiency DH5&amp;alpha; Competent Cells</td><td>Invitrogen</td><td>18265017</td><td>used for the creation of pSD1 and pSD2</td></tr></tbody></table>

constructing mutants in serotype 1 streptococcus pneumoniae strain 519/43

肺炎链球菌血清1型仍然是低收入和中等收入国家的一个大问题，特别是在撒哈拉以南非洲。尽管它很重要，但由于缺乏遗传工具来修饰它，这种血清型的研究受到了阻碍。在这项研究中，我们描述了一种对血清型1临床分离株（菌株519/43）进行基因修饰的方法。有趣的是，这是通过利用肺炎球菌自然获取DNA的能力来实现的。然而，与大多数肺炎球菌不同，线性DNA的使用并不成功;为了突变这种重要的菌株，必须使用自杀质粒。这种方法为更深入地了解这种难以捉摸的血清型提供了手段，无论是在生物学上还是在致病性方面。为了验证该方法，已知的主要肺炎球菌毒素肺溶血素发生了突变，因为它具有众所周知且易于遵循的表型。我们表明，正如预期的那样，突变体失去了裂解红细胞的能力。通过能够突变感兴趣的血清型中的重要基因，我们能够观察到腹膜内和鼻内感染时功能丧失突变体的不同表型与其他血清型观察到的表型不同。综上所述，本研究证明菌株519/43（血清型1）可以进行基因改造。

这里描述的方案首先使用PCR扩增左右同源臂，同时从 层 基因的中间区域删除191 bp。在进行PCR时，在左同源臂的3'和右同源臂的5'端引入BamHI位点（图1A）。接下来是PCR-SOE，其中左和右同源臂融合成一个扩增子（图1B）。然后将该SOE-PCR扩增子克隆到pGEMTeasy中使用TA克隆以生成质粒pSD1（图1C）。成功转化将产生对氨苄青霉素耐药...

Watch this Scientific Journal Video about Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43 at JoVE.com

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

在这里，我们描述了一种 肺炎链球菌 血清型1菌株519/43，该菌株可以通过利用其自然获取DNA和自杀质粒的能力进行基因改造。作为原理证明，在肺溶血素（ply）基因中制造了同基因突变体。

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, ...

constructing-mutants-serotype-1-streptococcus-pneumoniae-strain

Universidad de Cartagena UDEC

Research

JoVE Journal

Immunology and Infection

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

1.6K 次观看.  London School of Hygiene and Tropical Medicine. 在这里，我们描述了一种 肺炎链球菌 血清型1菌株519/43，该菌株可以通过利用其自然获取DNA和自杀质粒的能力进行基因改造。作为原理证明，在肺溶血素（ply）基因中制造了同基因突变体。

视频: Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

Generation of a Gene-disrupted Streptococcus mutans Strain Without Gene Cloning

Typical methods for the elucidation of the function of a particular gene involve comparative phenotypic analyses of the wild-type strain and a strain in which the gene of interest has been disrupted. A gene-disruption DNA construct containing a suitable antibiotic resistance marker gene is useful for the generation of gene-disrupted strains in bacteria. However, conventional construction methods, which require gene cloning steps, involve complex and time-consuming protocols. Here, a relatively facile, rapid, and cost-effective method for targeted gene disruption in Streptococcus mutans is described. The method utilizes a 2-step fusion polymerase chain reaction (PCR) to generate the disruption construct and electroporation for genetic transformation. This method does not require an enzymatic reaction, other than PCR, and additionally offers greater flexibility in terms of the design of the disruption construct. Employment of electroporation facilitates the preparation of competent cells and improves the transformation efficiency. The present method may be adapted for the generation of gene-disrupted strains of various species.

Generation of a Gene-disrupted Streptococcus mutans Strain Without Gene Cloning

We describe a facile, rapid, and relatively inexpensive method for the generation of gene-disrupted Streptococcus mutans strains; this technique may be adapted for the generation of gene-disrupted strains of various species.

无基因克隆的基因破坏的变形链球菌菌株的生成

Typical methods for the elucidation of the function of a particular gene involve comparative phenotypic analyses of the wild-type strain and a strain in ...

科研

遗传学

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae

Nasopharyngeal colonization by Streptococcus pneumoniae is a prerequisite to invasion to the lungs or bloodstream1. This organism is capable of colonizing the mucosal surface of the nasopharynx, where it can reside, multiply and eventually overcome host defences to invade to other tissues of the host. Establishment of an infection in the normally lower respiratory tract results in pneumonia. Alternatively, the bacteria can disseminate into the bloodstream causing bacteraemia, which is associated with high mortality rates2, or else lead directly to the development of pneumococcal meningitis. Understanding the kinetics of, and immune responses to, nasopharyngeal colonization is an important aspect of S. pneumoniae infection models.
Our mouse model of intranasal colonization is adapted from human models3 and has been used by multiple research groups in the study of host-pathogen responses in the nasopharynx4-7. In the first part of the model, we use a clinical isolate of S. pneumoniae to establish a self-limiting bacterial colonization that is similar to carriage events in human adults. The procedure detailed herein involves preparation of a bacterial inoculum, followed by the establishment of a colonization event through delivery of the inoculum via an intranasal route of administration. Resident macrophages are the predominant cell type in the nasopharynx during the steady state. Typically, there are few lymphocytes present in uninfected mice8, however mucosal colonization will lead to low- to high-grade inflammation (depending on the virulence of the bacterial species and strain) that will result in an immune response and the subsequent recruitment of host immune cells. These cells can be isolated by a lavage of the tracheal contents through the nares, and correlated to the density of colonization bacteria to better understand the kinetics of the infection.

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae

Colonization of the murine nasopharynx with Streptococcus pneumoniae and the subsequent extraction of adherent or recruited cells is described. This technique involves flushing the nasopharynx and collection of the fluid through the nares and is adaptable for various readouts, including differential cell quantification and analysis of mRNA expression in situ.

肺炎链球菌在鼻内殖民期间炎症反应的特征

Nasopharyngeal colonization by Streptococcus pneumoniae is a prerequisite to invasion to the lungs or bloodstream1. This organism is capable of colonizing ...

免疫与感染

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Pneumonia is one of the major health care problems in developing and industrialized countries and is associated with considerable morbidity and mortality. Despite advances in knowledge of this illness, the availability of intensive care units (ICU), and the use of potent antimicrobial agents and effective vaccines, the mortality rates remain high1. Streptococcus pneumoniae is the leading pathogen of community-acquired pneumonia (CAP) and one of the most common causes of bacteremia in humans. This pathogen is equipped with an armamentarium of surface-exposed adhesins and virulence factors contributing to pneumonia and invasive pneumococcal disease (IPD). The assessment of the in vivo role of bacterial fitness or virulence factors is of utmost importance to unravel S. pneumoniae pathogenicity mechanisms. Murine models of pneumonia, bacteremia, and meningitis are being used to determine the impact of pneumococcal factors at different stages of the infection. Here we describe a protocol to monitor in real-time pneumococcal dissemination in mice after intranasal or intraperitoneal infections with bioluminescent bacteria. The results show the multiplication and dissemination of pneumococci in the lower respiratory tract and blood, which can be visualized and evaluated using an imaging system and the accompanying analysis software.

Streptococcus pneumoniae is the leading pathogen causing severe community-acquired pneumonia and responsible for over 2&#160;million deaths worldwide. The impact of bacterial factors implicated in fitness or virulence can be monitored in real-time in an acute mouse pneumonia or bacteremia model using bioluminescent bacteria.

在实时以下的肺炎球菌毒力因子在小鼠急性肺炎模型的影响采用发光细菌

Pneumonia is one of the major health care problems in developing and industrialized countries and is associated with considerable morbidity and mortality. ...

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction

There are over 90 different capsular serotypes of Streptococcus pneumoniae (the pneumococcus). As well as being a tool for understanding pneumococcal epidemiology, capsular serotyping can provide useful information for vaccine efficacy and impact studies.&#160;The Quellung reaction is the gold standard method for pneumococcal capsular serotyping. The method involves testing a pneumococcal cell suspension with pooled and specific antisera directed against the capsular polysaccharide. The antigen-antibody reactions are observed microscopically. The protocol has three main steps: 1) preparation of a bacterial cell suspension, 2) mixing of cells and antisera on a glass slide, and 3) reading the Quellung reaction using a microscope. The Quellung reaction is reasonably simple to perform and can be applied wherever a suitable microscope and antisera are available.

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction

The Quellung reaction is the gold standard technique for serotyping Streptococcus pneumoniae. This technique utilizes a microscope and specific pneumococcal antisera and is commonly used in reference and research laboratories worldwide.

荚膜血清型<em&gt;肺炎链球菌</em&gt;使用荚膜肿胀反应

There are over 90 different capsular serotypes of Streptococcus pneumoniae (the pneumococcus). As well as being a tool for understanding pneumococcal ...

Visualization of Streptococcus pneumoniae within Cardiac Microlesions and Subsequent Cardiac Remodeling

During bacteremia Streptococcus pneumoniae can translocate across the vascular endothelium into the myocardium and form discrete bacteria-filled microscopic lesions (microlesions) that are remarkable due to the absence of infiltrating immune cells. Due to their release of cardiotoxic products, S. pneumoniae within microlesions are thought to contribute to the heart failure that is frequently observed during fulminate invasive pneumococcal disease in adults. Herein is demonstrated a protocol for experimental mouse infection that leads to reproducible cardiac microlesion formation within 30 hr. Instruction is provided on microlesion identification in hematoxylin &#38; eosin stained heart sections and the morphological distinctions between early and late microlesions are highlighted. Instruction is provided on a protocol for verification of S. pneumoniae within microlesions using antibodies against pneumococcal capsular polysaccharide and immunofluorescent microscopy. Last, a protocol for antibiotic intervention that rescues infected mice and for the detection and assessment of scar formation in the hearts of convalescent mice is provided. Together, these protocols will facilitate the investigation of the molecular mechanisms underlying pneumococcal cardiac invasion, cardiomyocyte death, cardiac remodeling as a result of exposure to S. pneumoniae, and the immune response to the pneumococci in the heart.

Visualization of Streptococcus pneumoniae within Cardiac Microlesions and Subsequent Cardiac Remodeling

Streptococcus pneumoniae forms discrete non-purulent microscopic lesions in the heart. Outlined is the protocol for a murine model of cardiac microlesion formation. Instruction is provided on microlesion visualization using microscopy, discrimination between early and late microlesions, and methods to detect cardiac remodeling in hearts of convalescent animals.

可视化<em&gt;肺炎链球菌</em&gt;在心脏Microlesions和随后的心脏重构

During bacteremia Streptococcus pneumoniae can translocate across the vascular endothelium into the myocardium and form discrete bacteria-filled ...

医学

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 ...

Homogeneous Glycoconjugate Produced by Combined Unnatural Amino Acid Incorporation and Click-Chemistry for Vaccine Purposes

Genetic code expansion is a powerful tool to introduce unnatural amino acids (UAAs) into proteins to modify their characteristics, to study or create new protein functions or to have access to protein conjugates. Stop codon suppression, in particular amber codon suppression, has emerged as the most popular method to genetically introduce UAAs at defined positions. This methodology is herein applied to the preparation of a carrier protein containing an UAA harboring a bioorthogonal functional group. This reactive handle can next be used to specifically and efficiently graft a synthetic oligosaccharide hapten to provide a homogeneous glycoconjugate vaccine. The protocol is limited to the synthesis of glycoconjugates in a 1:1 carbohydrate hapten/carrier protein ratio but amenable to numerous pairs of biorthogonal functional groups. Glycococonjugate vaccine homogeneity is an important criterion to ensure complete physico-chemical characterization, thereby, satisfying more and more demanding drug regulatory agency recommendations, a criterion which is unmet by classical conjugation strategies. Moreover, this protocol makes it possible to finely tune the structure of the actual conjugate vaccine, giving rise to tools to address structure-immunogenicity relationships.

Genetic code expansion is applied for the introduction of an unnatural amino acid bearing a biorthogonal functional group on a carrier protein at a defined site. The biorthogonal function is further used for the site-selective coupling of a carbohydrate antigen to provide a homogeneous glycoconjugate vaccine.

联合非自然氨基酸合并和点击化学为疫苗目的生产的同质糖共酶

Genetic code expansion is a powerful tool to introduce unnatural amino acids (UAAs) into proteins to modify their characteristics, to study or create new ...

生物工程

Purification of a High Molecular Mass Protein in Streptococcus mutans

Elucidation of a gene&#39;s function typically involves comparison of phenotypic traits of wild-type strains and strains in which the gene of interest has been disrupted. Loss of function following gene disruption is subsequently restored by exogenous addition of the product of the disrupted gene. This helps to determine the function of the gene. A method previously described involves generating a gtfC gene-disrupted Streptococcus mutans strain. Here, an undemanding method is described for purifying the gtfC gene product from the newly generated S. mutans strain following the gene disruption. It involves the addition of a polyhistidine-coding sequence at the 3&#8242; end of the gene of interest, which allows simple purification of the gene product using immobilized metal affinity chromatography. No enzymatic reactions other than PCR are required for the genetic modification in this method. The restoration of the gene product by exogenous addition after gene disruption is an efficient method for determining gene function, which may also be adapted to different species.

Purification of a High Molecular Mass Protein in Streptococcus mutans

Described here is a simple method for the purification of a gene product in Streptococcus mutans. This technique may be advantageous in the purification of proteins, especially membrane proteins and high molecular mass proteins, and can be used with various other bacterial species.

链球菌中高分子质量蛋白的纯化

Elucidation of a gene&#39;s function typically involves comparison of phenotypic traits of wild-type strains and strains in which the gene of interest has ...

Inducing Meningococcal Meningitis Serogroup C in Mice via Intracisternal Delivery

Neisseria meningitidis (meningococcus) is a narrow-host-range microorganism, globally recognized as the leading cause of bacterial meningitis. Meningococcus is a transient colonizer of human nasopharynx of approximately 10% of healthy subject. In particular circumstances, it acquires an invasive ability to penetrate the mucosal barrier and invades the bloodstream causing septicaemia. In the latest case, fulminating sepsis could arise even without the consequent development of meningitis. Conversely, bacteria could poorly multiply in the bloodstream, cross the blood brain barrier, reach the central nervous system, leading to fulminant meningitis. The murine models of bacterial meningitis represent a useful tool to investigate the host-pathogen interactions and to analyze the pathogenetic mechanisms responsible for this lethal disease. Although, several experimental model systems have been evaluated over the last decades, none of these were able to reproduce the characteristic pathological events of meningococcal disease. In this experimental protocol, we describe a detailed procedure for the induction of meningococcal meningitis in a mouse model based on the intracisternal inoculation of bacteria. The peculiar signs of human meningitis were recorded in the murine host through the assessment of clinical parameters (e.g., temperature, body weight), evaluation of survival rate, microbiological analysis and histological examination of brain injury. When using intracisternal (i.cist.) inoculum, meningococci complete delivery directly into cisterna magna, leading to a very efficient meningococcal replication in the brain tissue. A 1,000-fold increase of viable count of bacteria is observed in about 18 h. Moreover, meningococci are also found in the spleen, and liver of infected mice, suggesting that the liver may represent a target organ for meningococcal replication.

Here, we describe a method to induce meningococcal meningitis through an intracisternal route of infection in adult mice. We present a step by step protocol of meningococcal infection from the preparation of inoculum to the intracisternal infection; then record the animal survival and evaluate the bacterial loads in murine tissues.

通过细胞内分娩诱导小鼠脑膜炎球菌性脑膜炎血清群C

Neisseria meningitidis (meningococcus) is a narrow-host-range microorganism, globally recognized as the leading cause of bacterial meningitis. ...

Generation of In-Frame Gene Deletion Mutants in Pseudomonas aeruginosa and Testing for Virulence Attenuation in a Simple Mouse Model of Infection

Microorganisms are genetically versatile and diverse and have become a major source of many commercial products and biopharmaceuticals. Though some of these products are naturally produced by the organisms, other products require genetic engineering of the organism to increase the yields of production. Avirulent strains of Escherichia coli have traditionally been the preferred bacterial species for producing biopharmaceuticals; however, some products are difficult for E. coli to produce. Thus, avirulent strains of other bacterial species could provide useful alternatives for production of some commercial products. Pseudomonas aeruginosa is a common and well-studied Gram-negative bacterium that could provide a suitable alternative to E. coli. However, P. aeruginosa is an opportunistic human pathogen. Here, we detail a procedure that can be used to generate nonpathogenic strains of P. aeruginosa through sequential genomic deletions using the pEX100T-NotI plasmid. The main advantage of this method is to produce a marker-free strain. This method may be used to generate highly attenuated P. aeruginosa strains for the production of commercial products, or to design strains for other specific uses. We also describe a simple and reproducible mouse model of bacterial systemic infection via intraperitoneal injection of validated test strains to test the attenuation of the genetically engineered strain in comparison to the FDA-approved BL21 strain of E. coli.

Generation of In-Frame Gene Deletion Mutants in Pseudomonas aeruginosa and Testing for Virulence Attenuation in a Simple Mouse Model of Infection

Here, we describe a simple and reproducible protocol of mouse model of infection to evaluate the attenuation of the genetically modified strains of Pseudomonas aeruginosa in comparison to the United States Food and Drug Administration (FDA)-approved Escherichia coli for commercial applications.

在伪单体中生成帧内基因删除突变体，并在简单小鼠感染模型中测试病毒衰减

Microorganisms are genetically versatile and diverse and have become a major source of many commercial products and biopharmaceuticals. Though some of ...

在血清型 1 型肺炎链球菌菌株 519/43 中构建突变体

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此视频中的章节

无基因克隆的基因破坏的变形链球菌菌株的生成

肺炎链球菌在鼻内殖民期间炎症反应的特征

在实时以下的肺炎球菌毒力因子在小鼠急性肺炎模型的影响采用发光细菌

荚膜血清型

可视化

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

联合非自然氨基酸合并和点击化学为疫苗目的生产的同质糖共酶

链球菌中高分子质量蛋白的纯化

通过细胞内分娩诱导小鼠脑膜炎球菌性脑膜炎血清群C

在伪单体中生成帧内基因删除突变体，并在简单小鼠感染模型中测试病毒衰减

在血清型 1 型肺炎链球菌 菌株 519/43 中构建突变体

摘要

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此视频中的章节

无基因克隆的基因破坏的变形链球菌菌株的生成

肺炎链球菌在鼻内殖民期间炎症反应的特征

在实时以下的肺炎球菌毒力因子在小鼠急性肺炎模型的影响采用发光细菌

荚膜血清型

可视化

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

联合非自然氨基酸合并和点击化学为疫苗目的生产的同质糖共酶

链球菌中高分子质量蛋白的纯化

通过细胞内分娩诱导小鼠脑膜炎球菌性脑膜炎血清群C

在伪单体中生成帧内基因删除突变体，并在简单小鼠感染模型中测试病毒衰减

在血清型 1 型肺炎链球菌菌株 519/43 中构建突变体