We thank T. Ito, K. Hiramatsu, R. Daum, H. de Lencastre, and D. Coleman for the kind gift of some reference strains used in this study. This work was in part supported financially by the Centre for Antimicrobial Resistance (CAR), Alberta Health Services-Calgary/Calgary Laboratory Services/University of Calgary.

??????????????2????????????????????????,???,?????? 1?????<ol><li>??????????MRSA??????PCR?????????,???????MRSA????????????(TSA)?,??????????????????????????????????,?37

<ol>
	<li>IWG-SCC. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Classification+of+staphylococcal+cassette+chromosome+mec+(SCCmec):+guidelines+for+reporting+novel+SCCmec+elements.">Classification of staphylococcal cassette chromosome mec (SCCmec): guidelines for reporting novel SCCmec elements.</a> Antimicrobial Agents and Chemotherapy. 53 (12), 4961-4967 (2009).</li><li>Ito, T., Hiramatsu, K., Tomasz, A., de Lencastre, H., Perreten, V., Holden, 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=Guidelines+for+Reporting+Novel+mecA+Gene+Homologues.">Guidelines for Reporting Novel mecA Gene Homologues.</a> Antimicrobial Agents and Chemotherapy. 56 (10), 4997-4999 (2012).</li><li>Okuma, K., Iwakawa, K., Turnidge, J. D., Grubb, W. B., Bell, J. M., O'Brien, F. G., 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=Dissemination+of+new+methicillin-resistant+Staphylococcus+aureus+clones+in+the+community.">Dissemination of new methicillin-resistant Staphylococcus aureus clones in the community.</a> Journal of Clinical Microbiology. 40 (11), 4289-4294 (2002).</li><li>Kondo, Y., Ito, T., Ma, X. X., Watanabe, S., Kreiswirth, B. N., Etienne, 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=Combination+of+multiplex+PCRs+for+staphylococcal+cassette+chromosome+mec+type+assignment:+rapid+identification+system+for+mec,+ccr,+and+major+differences+in+junkyard+regions.">Combination of multiplex PCRs for staphylococcal cassette chromosome mec type assignment: rapid identification system for mec, ccr, and major differences in junkyard regions.</a> Antimicrobial Agents and Chemotherapy. 51 (1), 264-274 (2007).</li><li>Oliveira, D. C., de Lencastre, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiplex+PCR+strategy+for+rapid+identification+of+structural+types+and+variants+of+the+mec+element+in+methicillin-resistant+Staphylococcus+aureus.">Multiplex PCR strategy for rapid identification of structural types and variants of the mec element in methicillin-resistant Staphylococcus aureus.</a> Antimicrobial Agents and Chemotherapy. 46 (7), 2155-2161 (2002).</li><li>Milheirico, C., Oliveira, D. C., de Lencastre, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Update+to+the+multiplex+PCR+strategy+for+assignment+of+mec+element+types+in+Staphylococcus+aureus.">Update to the multiplex PCR strategy for assignment of mec element types in Staphylococcus aureus.</a> Antimicrobial Agents and Chemotherapy. 51 (9), 3374-3377 (2007).</li><li>Milheirico, C., Oliveira, D. C., de Lencastre, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiplex+PCR+strategy+for+subtyping+the+staphylococcal+cassette+chromosome+mec+type+IV+in+methicillin-resistant+Staphylococcus+aureus:+'SCCmec+IV+multiplex'.">Multiplex PCR strategy for subtyping the staphylococcal cassette chromosome mec type IV in methicillin-resistant Staphylococcus aureus: 'SCCmec IV multiplex'.</a> Journal of Antimicrobial Chemotherapy. 60 (1), 42-48 (2007).</li><li>Zhang, K., McClure, J. A., Elsayed, S., Louie, T., Conly, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+multiplex+PCR+assay+for+characterization+and+concomitant+subtyping+of+staphylococcal+cassette+chromosome+mec+types+I+to+V+in+methicillin-resistant+Staphylococcus+aureus.">Novel multiplex PCR assay for characterization and concomitant subtyping of staphylococcal cassette chromosome mec types I to V in methicillin-resistant Staphylococcus aureus.</a> Journal of Clinical Microbiology. 43 (10), 5026-5033 (2005).</li><li>Zhang, K., McClure, J. A., Conly, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+multiplex+PCR+assay+for+typing+of+staphylococcal+cassette+chromosome+mec+types+I+to+V+in+methicillin-resistant+Staphylococcus+aureus.">Enhanced multiplex PCR assay for typing of staphylococcal cassette chromosome mec types I to V in methicillin-resistant Staphylococcus aureus.</a> Molecular and Cellular Probes. 26 (5), 218-221 (2012).</li><li>de Lamballerie, X., Zandotti, C., Vignoli, C., Bollet, C., de Micco, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+one-step+microbial+DNA+extraction+method+using+"Chelex+100"+suitable+for+gene+amplification.">A one-step microbial DNA extraction method using "Chelex 100" suitable for gene amplification.</a> Research in Microbiology. 143 (8), 785-790 (1992).</li><li>Lee, P. Y., Costumbrado, J., Hsu, C. Y., Kim, Y. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Agarose+gel+electrophoresis+for+the+separation+of+DNA+fragments.">Agarose gel electrophoresis for the separation of DNA fragments.</a> J. Vis. Exp. (62), e3923 (2012).</li><li>McClure, J. A., Conly, J. M., Elsayed, S., Zhang, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiplex+PCR+assay+to+facilitate+identification+of+the+recently+described+Staphylococcal+cassette+chromosome+mec+type+VIII.">Multiplex PCR assay to facilitate identification of the recently described Staphylococcal cassette chromosome mec type VIII.</a> Molecular and Cellular Probes. 24 (4), 229-232 (2010).</li><li>Zhang, K., McClure, J. A., Elsayed, S., Conly, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+staphylococcal+cassette+chromosome+mec+type,+tentatively+designated+type+VIII,+harboring+class+A+mec+and+type+4+ccr+gene+complexes+in+a+Canadian+epidemic+strain+of+methicillin-resistant+Staphylococcus+aureus.">Novel staphylococcal cassette chromosome mec type, tentatively designated type VIII, harboring class A mec and type 4 ccr gene complexes in a Canadian epidemic strain of methicillin-resistant Staphylococcus aureus.</a> Antimicrobial Agents and Chemotherapy. 53 (2), 531-540 (2009).</li></ol>

No conflicts of interest declared.

The multiplex PCR assay described here provides a simple, reliable method for classifying types and major subtypes of SCCmec I-V in Staphylococci, with simultaneous discrimination of MRSA from MSSA. The assay is robust, conveniently done in a single PCR reaction and results are easy to interpret. The assay does have limitations in that it targets individual loci within each SCCmec type, but does not offer comprehensive ccr and mec complex typing, and therefore cannot be considered a go...

An erratum was issued for: <a href="https://jove.unicartagenaproxy.elogim.com/video/50779/multiplex-pcr-assay-for-typing-staphylococcal-cassette-chromosome-mec">Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus</a>.&#160; There was a&#160;typo&#160;in Table 1.
In Table 1, the Oligonucleotide sequence for Type III-F5 was updated from:
TTCTCATTGATGCTGAAGCC
To:
GAAACTAGTTATTTCCAACGG

An erratum was issued for: <a href="https://jove.unicartagenaproxy.elogim.com/video/50779/multiplex-pcr-assay-for-typing-staphylococcal-cassette-chromosome-mec">Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus</a>.&#160; There was a&#160;typo&#160;in Table 1.

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

???????????? (MRSA)?????????????21-67-KB??????,??????????????MEC(SCC MEC)??????????(MECA)??????????1 ? SCC MEC?????????,???????????(mec??????ccr??????),?J?(?1)????,???????431mec,mecA?? ,???????????,mecR1 MECI mec???????,?CCR????????????(CCR / ccrAB? )????SCC MEC??????1?????? MEC??????????(MECB </EM&gt;?MECC)?????,??????????mecA??2? SCC MEC?????????????????MEC?ccr????,????????????J?(J1,J2?J3)? MEC??????(?A,B,C,D?E)????CCR???(?1-8)?????????????????????SCC MEC???? SCC MEC???SCC MEC???????????????????????????(IWG-SCC)?????,?? ?????MEC?CCR????????,???????????,?????J??DNA 1? MRSA????????(??/???)??????,????????(ST)?/??????????A??( ?? )??( ? ST8???SCC MEC??????-T008-MRSA-IVA)???,SCC MEC??????????????,?????MRSA?????????,??????????MRSA(CA-MRSA)??????????? ??PCR??????SCC MEC??????????MEC?ccr????????,???????(20?30),?????????PCR?????? ,??,??21??????????PCR????SCC MEC?IVB 3? Kondo ????quently??ccr?MEC,??J??????????????????????,?????????????PCR??4?????SCC MEC??,??PCR(M-PCR)?????????PCR???????????Lencastre????????M-PCR????SCC MEC I-IV,?????SCC MEC IV,????????SCC?MEC???5,6,7 M-PCR???,?????????????,??2???,????SCC MEC IV??,??????????????????SCC MEC??,???????????????PCR????????SCC MEC?????????,??V 8,???????????????became 9????????????SCC MEC??,????????,?????,????????(337 SCOPUS,???2013?1?30?)???????,????????????????????????MRSA SCC MEC????????????????????????????,??????,??????????????????MRSA SCC ?????????,????????????M-PCR?SCC MEC??,???????????????????????????

<table><tbody><tr><td>Tryptic Soy Agar</td><td>Fisher (BD)</td><td>CA90002-700 (236920)</td><td></td></tr><tr><td>Sterile distilled water</td><td>Life Technologies</td><td>10977-015</td><td></td></tr><tr><td>Platinum Taq: including 10x PCR buffer and 50 mM MgCl&lt;sub&gt;2&lt;/sub&gt;</td><td>Life Technologies</td><td>10966-034</td><td></td></tr><tr><td>100 mM dNTP</td><td>Life Technologies</td><td>10297-018</td><td></td></tr><tr><td>Tris base</td><td>Sigma-Aldrich</td><td>T6066</td><td></td></tr><tr><td>Boric acid</td><td>Sigma-Aldrich</td><td>B7901</td><td></td></tr><tr><td>EDTA</td><td>Life Technologies</td><td>15576-028</td><td></td></tr><tr><td>Agarose</td><td>Life Technologies</td><td>16500-500</td><td></td></tr><tr><td>Glycerol</td><td>Life Technologies</td><td>15514-011</td><td></td></tr><tr><td>Bromophenol blue</td><td>Sigma-Aldrich</td><td>B8026</td><td></td></tr><tr><td>1Kb+ DNA ladder</td><td>Life Technologies</td><td>10787-026</td><td></td></tr><tr><td>Ethidium bromide</td><td>Sigma-Aldrich</td><td>E7637</td><td></td></tr><tr><td>1.5ml Microcentrifuge tubes </td><td>VWR (Axygen Scientific)</td><td>10011-700</td><td></td></tr><tr><td>Culture sticks</td><td>VWR</td><td>CA10805-018</td><td></td></tr><tr><td>PCR tubes</td><td>Diamed</td><td>AD0210-FCN (new #: DIATEC420-1250)</td><td></td></tr><tr><td>Centrifuge</td><td>Eppendorf</td><td>5417c</td><td></td></tr><tr><td>Heat block</td><td>VWR</td><td>13259-030 / 13259-286</td><td></td></tr><tr><td>Thermalcycler</td><td>Applied Biosystems (2720)</td><td>4359659</td><td></td></tr><tr><td>Horizontal, submersible gel electrophoresis chamber with gel mold</td><td>BioRad</td><td>170-4469</td><td></td></tr><tr><td>Power supply</td><td>BioRad</td><td>164-5050</td><td></td></tr><tr><td>Rocker shaker</td><td>VWR</td><td>40000-300</td><td></td></tr><tr><td>Molecular Imager Gel Doc System</td><td>BioRad</td><td>1708170</td><td></td></tr></tbody></table>

multiplex pcr assay for typing of staphylococcal cassette chromosome mec types i to v in methicillin-resistant staphylococcus aureus

????????????MEC(SCC MEC) ??????????????,??????????????? (MRSA)????????????,??????????MRSA(CA-MRSA)?????????????PCR??????SCC MEC??????????MEC?ccr????????,???????????????PCR??????????????????PCR????SCC MEC????????I?V,????????????????????????????SCC MEC??,????????,?????,?????????????,?????NATURE????????????,??????,???????????????????MRSA SCC ?????????,???,??????????????PCR??,??????,?????????????????????

This updated M-PCR is able to determine (classify) SCCmec types I-V, as well major subtypes of SCCmec IV. The assay targets unique and specific loci of SCCmec I, II, III, IVa, IVb, IVc, IVd, IVE and V, with concomitant mecA gene detection. Tentative identification of SCCmec VI and VIII is also possible, but would require further testing to confirm. Figure 3 illustrates representative SCCmec I-VI and VIII and the locations of each target within the ele...

Watch this Scientific Journal Video about Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus at JoVE.com

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.

??PCR?????????????????????MEC??????V<em&gt;???????</em

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

multiplex-pcr-assay-for-typing-staphylococcal-cassette-chromosome-mec

Universidad de Cartagena UDEC

Research

JoVE Journal

Immunology and Infection

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

11.8K 次观看.  Alberta Health Services / Calgary Laboratory Services / University of Calgary. 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.

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

Screening Foodstuffs for Class 1 Integrons and Gene Cassettes

Antibiotic resistance is one of the greatest threats to health in the 21st century. Acquisition of resistance genes via lateral gene transfer is a major factor in the spread of diverse resistance mechanisms. Amongst the DNA elements facilitating lateral transfer, the class 1 integrons have largely been responsible for spreading antibiotic resistance determinants amongst Gram negative pathogens. In total, these integrons have acquired and disseminated over 130 different antibiotic resistance genes. With continued antibiotic use, class 1 integrons have become ubiquitous in commensals and pathogens of humans and their domesticated animals. As a consequence, they can now be found in all human waste streams, where they continue to acquire new genes, and have the potential to cycle back into humans via the food chain. This protocol details a streamlined approach for detecting class 1 integrons and their associated resistance gene cassettes in foodstuffs, using culturing and PCR. Using this protocol, researchers should be able to: collect and prepare samples to make enriched cultures and screen for class 1 integrons; isolate single bacterial colonies to identify integron-positive isolates; identify bacterial species that contain class 1 integrons; and characterize these integrons and their associated gene cassettes.

This protocol describes the detection of class 1 integrons and their associated gene cassettes in foodstuffs.

食品筛查为1类整合和基因盒

Antibiotic resistance is one of the greatest threats to health in the 21st century. Acquisition of resistance genes via lateral gene transfer is a major ...

科研

环境科学

One-day Workflow Scheme for Bacterial Pathogen Detection and Antimicrobial Resistance Testing from Blood Cultures

Bloodstream infections are associated with high mortality rates because of the probable manifestation of sepsis, severe sepsis and septic shock1. Therefore, rapid administration of adequate antibiotic therapy is of foremost importance in the treatment of bloodstream infections. The critical element in this process is timing, heavily dependent on the results of bacterial identification and antibiotic susceptibility testing. Both of these parameters are routinely obtained by culture-based testing, which is time-consuming and takes on average 24-48 hours2, 4. The aim of the study was to develop DNA-based assays for rapid identification of bloodstream infections, as well as rapid antimicrobial susceptibility testing. The first assay is a eubacterial 16S rDNA-based real-time PCR assay complemented with species- or genus-specific probes5. Using these probes, Gram-negative bacteria including Pseudomonas spp., Pseudomonas aeruginosa and Escherichia coli as well as Gram-positive bacteria including Staphylococcus spp., Staphylococcus aureus, Enterococcus spp., Streptococcus spp., and Streptococcus pneumoniae could be distinguished. Using this multiprobe assay, a first identification of the causative micro-organism was given after 2 h.
Secondly, we developed a semi-molecular assay for antibiotic susceptibility testing of S. aureus, Enterococcus spp. and (facultative) aerobe Gram-negative rods6. This assay was based on a study in which PCR was used to measure the growth of bacteria7. Bacteria harvested directly from blood cultures are incubated for 6 h with a selection of antibiotics, and following a Sybr Green-based real-time PCR assay determines inhibition of growth. The combination of these two methods could direct the choice of a suitable antibiotic therapy on the same day (Figure 1). In conclusion, molecular analysis of both identification and antibiotic susceptibility offers a faster alternative for pathogen detection and could improve the diagnosis of bloodstream infections.

The design of a straightforward one-day workflow scheme for bacterial pathogen diagnostics enables the rapid recognition of bloodstream infections. The inclusion of eight clinically relevant bacterial targets and their antibiotic resistance profiles offers the clinician an initial insight on the same day, which can lead to more adequate therapy.

为期一天的血培养的细菌病原体检测和耐药性检测的工作流程计划

Bloodstream infections are associated with high mortality rates because of the probable manifestation of sepsis, severe sepsis and septic shock1. ...

免疫与感染

Multiplex Detection of Bacteria in Complex Clinical and Environmental Samples using Oligonucleotide-coupled Fluorescent Microspheres

Bacterial vaginosis (BV) is a recurring polymicrobial syndrome that is characterized by a change in the "normal" microbiota from Lactobacillus-dominated to a microbiota dominated by a number of bacterial species, including Gardnerella vaginalis, Atopobium vaginae, and others1-3. This condition is associated with a range of negative health outcomes, including HIV acquisition4, and it can be difficult to manage clinically5. Furthermore, diagnosis of BV has relied on the use of Gram stains of vaginal swab smears that are scored on various numerical criteria6,7. While this diagnostic is simple, inexpensive, and well suited to resource-limited settings, it can suffer from problems related to subjective interpretations and it does not give a detailed profile of the composition of the vaginal microbiota8. Recent deep sequencing efforts have revealed a rich, diverse vaginal microbiota with clear differences between samples taken from individuals that are diagnosed with BV compared to those individuals that are considered normal9,10, which has resulted in the identification of a number of potential targets for molecular diagnosis of BV11,12. These studies have provided a wealth of useful information, but deep sequencing is not yet practical as a diagnostic method in a clinical setting. We have recently described a method for rapidly profiling the vaginal microbiota in a multiplex format using oligonucleotide-coupled fluorescent beads with detection on a Luminex platform13. This method, like current Gram stain-based methods, is rapid and simple but adds the additional advantage of exploiting molecular knowledge arising from sequencing studies in probe design. This method therefore provides a way to profile the major microorganisms that are present in a vaginal swab that can be used to diagnose BV with high specificity and sensitivity compared to Gram stain while providing additional information on species presence and abundance in a semi-quantitative and rapid manner. This multiplex method is expandable well beyond the range of current quantitative PCR assays for particular organisms, which is currently limited to 5 or 6 different assays in a single sample14. Importantly, the method is not limited to the detection of bacteria in vaginal swabs and can be easily adapted to rapidly profile nearly any microbial community of interest. For example, we have recently begun to apply this methodology to the development of diagnostic tools for use in wastewater treatment plants.

We describe a multiplex method for the detection of microorganisms within a sample using oligonucleotide-coupled fluorescent beads. Amplicon from all organisms within a sample is hybridized to a panel of probe-coupled beads. A Luminex or Bio-Plex instrument is used to query each bead for bead type and hybridization signal.

在复杂的临床和环境样本使用寡核苷酸加上荧光微多元检测细菌

Bacterial vaginosis (BV) is a recurring polymicrobial syndrome that is characterized by a change in the "normal" microbiota from Lactobacillus-dominated ...

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

A structurally transformed lytic bacteriophage having a broad host range of Staphylococcus aureus strains and a penicillin-binding protein (PBP 2a) antibody conjugated latex beads have been utilized to create a biosensor designed for discrimination of methicillin resistant (MRSA) and sensitive (MSSA) S. aureus species 1,2. The lytic phages have been converted into phage spheroids by contact with water-chloroform interface. Phage spheroid monolayers have been moved onto a biosensor surface by Langmuir-Blodgett (LB) technique 3. The created biosensors have been examined by a quartz crystal microbalance with dissipation tracking (QCM-D) to evaluate bacteria-phage interactions. Bacteria-spheroid interactions led to reduced resonance frequency and a rise in dissipation energy for both MRSA and MSSA strains. After the bacterial binding, these sensors have been further exposed to the penicillin-binding protein antibody latex beads. Sensors analyzed with MRSA responded to PBP 2a antibody beads; although sensors inspected with MSSA gave no response. This experimental distinction determines an unambiguous discrimination between methicillin resistant and sensitive S. aureus strains. Equally bound and unbound bacteriophages suppress bacterial growth on surfaces and in water suspensions. Once lytic phages are changed into spheroids, they retain their strong lytic activity and show high bacterial capture capability. The phage and phage spheroids can be utilized for testing and sterilization of antibiotic resistant microorganisms. Other applications may include use in bacteriophage therapy and antimicrobial surfaces.

Lytic phage biosensors and antibody beads are able to discriminate between methicillin resistant (MRSA) and sensitive staphylococcus bacteria. The phages were immobilized by a Langmuir-Blodgett method onto a surface of a quartz crystal microbalance sensor and worked as broad range staphylococcus probes. Antibody beads recognize MRSA.

生物传感器检测抗生素耐药金黄色葡萄球菌细菌

A structurally transformed lytic bacteriophage having a broad host range of Staphylococcus aureus strains and a penicillin-binding protein (PBP 2a) ...

生物工程

Multi-locus Variable-number Tandem-repeat Analysis of the Fish-pathogenic Bacterium Yersinia ruckeri by Multiplex PCR and Capillary Electrophoresis

Yersinia ruckeri is an important pathogen of farmed salmonids worldwide, but simple tools suitable for epizootiological investigations (infection tracing, etc.) of this bacterium have been lacking. A Multi-Locus Variable-number tandem-repeat Analysis (MLVA) assay was therefore developed as an easily accessible and unambiguous tool for high-resolution genotyping of recovered isolates. For the MLVA assay presented here, DNA is extracted from cultured Y. ruckeri samples by boiling bacterial cells in water, followed by use of supernatant as template for PCR. Primer-pairs targeting ten Variable-number tandem-repeat (VNTR) loci, interspersed throughout the Y. ruckeri genome, are distributed equally amongst two five-plex PCR reactions running under identical cycling conditions. Forward primers are labelled with either of three fluorescent dyes. Following amplicon confirmation by gel electrophoresis, PCR products are diluted and subjected to capillary electrophoresis. From the resulting electropherogram profiles, peaks representing each of the VNTR loci are size-called and employed for calculating VNTR repeat counts in silico. Resulting ten-digit MLVA profiles are then&#160;used to generate Minimum spanning trees enabling epizootiological evaluation by cluster analysis. The highly portable output data, in the form of numerical MLVA profiles, can rapidly be compared across labs and placed in a spatiotemporal context. The entire procedure from cultured colony to epizootiological evaluation may be completed for up to 48 Y. ruckeri isolates within a single working day.

Multi-locus Variable-number Tandem-repeat Analysis of the Fish-pathogenic Bacterium Yersinia ruckeri by Multiplex PCR and Capillary Electrophoresis

The Multi-Locus Variable-number tandem-repeat Analysis (MLVA) assay presented here enables inexpensive, robust and portable high-resolution genotyping of the fish-pathogenic bacterium Yersinia ruckeri. Starting from pure cultures, the assay employs multiplex PCR and capillary electrophoresis to produce ten-loci MLVA profiles for downstream applications.

多点PCR和毛细血管电泳对鱼类致病菌的多点变量数串联重复分析

Yersinia ruckeri is an important pathogen of farmed salmonids worldwide, but simple tools suitable for epizootiological investigations (infection tracing, ...

遗传学

Demonstrating a Multi-drug Resistant Mycobacterium tuberculosis Amplification Microarray

Simplifying microarray workflow is a necessary first step for creating MDR-TB microarray-based diagnostics that can be routinely used in lower-resource environments. An amplification microarray combines asymmetric PCR amplification, target size selection, target labeling, and microarray hybridization within a single solution and into a single microfluidic chamber. A batch processing method is demonstrated with a 9-plex asymmetric master mix and low-density gel element microarray for genotyping multi-drug resistant Mycobacterium tuberculosis (MDR-TB). The protocol described here can be completed in 6 hr and provide correct genotyping with at least 1,000 cell equivalents of genomic DNA. Incorporating on-chip wash steps is feasible, which will result in an entirely closed amplicon method and system. The extent of multiplexing with an amplification microarray is ultimately constrained by the number of primer pairs that can be combined into a single master mix and still achieve desired sensitivity and specificity performance metrics, rather than the number of probes that are immobilized on the array. Likewise, the total analysis time can be shortened or lengthened depending on the specific intended use, research question, and desired limits of detection. Nevertheless, the general approach significantly streamlines microarray workflow for the end user by reducing the number of manually intensive and time-consuming processing steps, and provides a simplified biochemical and microfluidic path for translating microarray-based diagnostics into routine clinical practice.

Demonstrating a Multi-drug Resistant Mycobacterium tuberculosis Amplification Microarray

An amplification microarray combines asymmetric PCR amplification and microarray hybridization into a single chamber, which significantly streamlines microarray workflow for the end user. Simplifying microarray workflow is a necessary first step for creating microarray-based diagnostics that can be routinely used in lower-resource environments.

展现着多药耐药<em&gt;结核分枝杆菌</em&gt;扩增基因芯片

Simplifying microarray workflow is a necessary first step for creating MDR-TB microarray-based diagnostics that can be routinely used in lower-resource ...

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 ...

Multiplex PCR and Reverse Line Blot Hybridization Assay (mPCR/RLB)

Multiplex PCR/Reverse Line Blot Hybridization assay allows the detection of up to 43 molecular targets in 43 samples using one multiplex PCR reaction followed by probe hybridization on a nylon membrane, which is re-usable. Probes are 5' amine modified to allow fixation to the membrane. Primers are 5' biotin modified which allows detection of hybridized PCR products using streptavidin-peroxidase and a chemiluminescent substrate via photosensitive film. With low setup and consumable costs, this technique is inexpensive (approximately US$2 per sample), high throughput (multiple membranes can be processed simultaneously) and has a short turnaround time (approximately 10 hours). 
The technique can be utilized in a number of ways. Multiple probes can be designed to detect sequence variation within a single amplified product, or multiple products can be amplified
simultaneously, with one (or more) probes used for subsequent detection. A combination of both approaches can also be used within a single assay. The ability to include multiple probes for a single target sequence makes the assay highly specific.
Published applications of mPCR/RLB include detection of antibiotic resistance genes1,2, typing of methicillin-resistant Staphylococcus aureus3-5 and Salmonella sp6, molecular serotyping of Streptococcus pneumoniae7,8, Streptococcus agalactiae9 and enteroviruses10,11, identification of Mycobacterium sp12, detection of genital13-15 and respiratory tract16 and other17 pathogens and detection and identification of mollicutes18. However, the versatility of the technique means the applications are virtually limitless and not restricted to molecular analysis of micro-organisms.
The five steps in mPCR/RLB are a) Primer and Probe design, b) DNA extraction and PCR amplification c) Preparation of the membrane, d) Hybridization and detection, and e) Regeneration of the Membrane.

Multiplex PCR and Reverse Line Blot Hybridization Assay mPCR/RLB

An inexpensive, high throughput method for simultaneous detection of up to 43 molecular targets is described. Applications of mPCR/RLB include microbial typing and detection of multiple pathogens from clinical samples.

多重PCR和反向线杂交检测（MPCR / RLB）

Multiplex PCR/Reverse Line Blot Hybridization assay allows the detection of up to 43 molecular targets in 43 samples using one multiplex PCR reaction ...

生物学

Rapid and Specific Detection of Acinetobacter baumannii Infections Using a Recombinase Polymerase Amplification/Cas12a-based System

Acinetobacter baumannii, a gram-negative bacterium, is notorious for causing severe infections with high mortality rates. Rapid and accurate detection of A. baumannii is crucial for prompt treatment, effective infection control, and curbing antibiotic resistance. However, there is no suitable method for rapid and easy on-site detection of A. baumannii. The DNA Endonuclease Targeted CRISPR Trans Reporter (DETECTR) system offers a rapid, precise, and sensitive approach to A. baumannii detection by integrating the target-specific recognition capabilities of Cas12a with the isothermal amplification efficiency of Recombinase Polymerase Amplification (RPA). This protocol details the detection of A. baumannii using RPA combined with LbaCas12a endonuclease. The following steps are described in this article: extraction of DNA, selection of a specific DNA sequence, design of primer and CRISPR RNA (crRNA), construction of positive recombinant plasmid, setup of Cas12a-RPA assay, optimization of the RPA amplification system, visualization of the RPA-CRISPR/Cas12a assay using a fluorescence detection tool such as a real-time PCR instrument, and evaluation of sensitivity and specificity evaluation.

To facilitate the rapid and precise detection of Acinetobacter baumannii, we present a protocol that employs Recombinase Polymerase Amplification (RPA) in conjunction with LbaCas12a endonuclease for identifying A. baumannii infections.

Acinetobacter baumannii, a gram-negative bacterium, is notorious for causing severe infections with high mortality rates. Rapid and accurate detection of ...

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