AccuGENX-ST® 是一种微生物表征过程，利用基于单基因和多基因座序列分型（S / MLST）的成熟、高准确度测序方法将密切相关的微生物在菌株层面加以区分。我们对微生物鉴定标准区域之外的标靶（16S、D2 或 ITS2）进行 DNA 测序，为您提供分辨菌株水平差异和/或相似性的数据。通过确定菌株水平，您可以明确地跟踪污染源，或者只是验证已知的生产菌株。
- 该基础以 DNA 测序结果为基础。
- SLST/MLST 数据是在全局范围内跟踪和记录细菌遗传关系的主要资源。
如果发生灭菌失败，客户可以向我们发送样品，我们可以协助确定根本原因。我们将首先通过 16S rDNA 测序鉴定分离物。如果 16S 序列不同，您可以确定分离物是不同的菌株。对于具有相同 16S 序列并且可以使用 SLST 或 MLST 完成的分离物，需要进一步表征。该技术旨在提供信息量最大的数据，并能从物种内的所有菌株中获得明确的结果。
使用 rRNA 区域进行微生物鉴定是一项可靠的技术。然而，有时需要额外的信息，并且必须能够区分物种层面以下的生物。通过测序、分析和比较生物体基因组中高度可变的基因座（区域），可以提高菌株水平的区分度。MLST 和 SLST 分析核心蛋白质编码基因或管家基因，这些基因对细菌正常细胞功能所必需的蛋白质进行编码，所有这些在其序列中包含更多的可变性。
从样品中提取可能存活或不存活的 DNA 后，该过程的第一步是获得物种水平的准确鉴定。这必须在开始 MLST 或 SLST 之前进行，以确定合适的靶标和引物组，因为对于每个被表征的物种，靶基因不相同。使用基因特异性引物对靶基因进行 PCR 扩增，并进行比较 DNA 序列分析。将来自每个基因靶的所有序列调整并与其他生物的序列数据进行比较，然后计算生物之间的趋异或保持水平，并用系统发育树显示。我们将为您解释数据，并说明特定基因靶标的测序是否无法区分分离物，或者分离物是否是不同的序列类型。
Why Outsource Sequence Typing Services Using Accugenix®
- The foundation is built upon DNA sequencing results.
- SLST and MLST data serve as primary resources for tracking and documenting the genetic relationship of bacteria at a global scale.
- SLST and MLST sequence-based stain typing results are easily cataloged and referenced for future comparisons.
- SLST and MLST techniques are highly reproducible, unambiguous, and scalable.
- Gain access to relevant organism library and bioinformatics experts
- Short turnaround times
In order to achieve a higher degree of resolution, each species is researched by our R&D team to determine the gene targets outside of the region used for identification that will most definitively resolve them at the subspecies or strain level. The number and identity of these loci vary for each species, due to the level of relatedness and rate of evolution within each group.
Would You Like E. coli with That?
Read about how AccuGENX-ST® was used to facilitate a contamination investigation at a dietary supplement and beverage manufacturing company.
Tracking Sources of Contamination
If a sterility failure occurs, customers can send samples to us, and we can assist in determining the root cause. We will first identify the isolates by 16S rDNA sequencing. If the 16S sequence is different, you can be sure that the isolates are different strains. Further characterization is necessary for those isolates that have identical 16S sequences and can be done using SLST or MLST (single and multilocus sequence typing). This strain typing technology is designed to deliver the most informative data and have the ability to obtain an unambiguous result from all strains within a species.
Our SLST and MLST sequence-based strain typing can help you map your microbial environment. We can create a library database of sequences from the microorganisms found in your manufacturing environment. When a contaminant is encountered, you can quickly pinpoint where you have seen that particular strain before. This greatly reduces the time and cost associated with identifying the source of contamination.
Methods for Sequence-based Strain Typing
Microbial identification using the rRNA regions is a robust technology. There are times, however, when additional information is needed and it is essential to be able to differentiate organisms below the species level. Increased discrimination at the strain level can be achieved by sequencing, analyzing and comparing highly variable loci (regions) in the organism's genome. MLST and SLST (single and multilocus sequence typing) analyze essential protein coding genes, or housekeeping genes, that encode for proteins necessary for the normal cellular functions of the bacterium all of which contain more variability in their sequences.
After extracting DNA from the sample, which can be viable or non-viable, the first step in this process is an accurate ID to the species level. This must be performed before starting MLST or SLST to determine appropriate targets and primer sets as the target genes will not be the same for each species being characterized.
The target genes are PCR amplified using the gene-specific primers and subjected to comparative DNA sequence analysis. All the sequences from each gene target are aligned and compared to the other organisms' sequence data and the level of divergence or conservation between the organisms is calculated and displayed with a phylogenetic tree. We will interpret the data for you and state whether the isolates are indistinguishable by the sequencing of the particular gene targets or whether the isolates are different sequence types.
Turnaround Time (TAT) Test Code 5 days AccuGENX-ST-5 5 days AccuGENX-XGST-5
Frequently Asked Questions (FAQs) About SLST and MLST
What is the difference between microbial identification and strain typing?
Genotypic microbial identification is performed by DNA sequencing of the conserved 16S rRNA in bacteria and IT2 region in fungi. The identification is made based on phylogenetic analysis and can only resolve down to the species level. Because members of the same species can still have genetic diversity, strain typing can be achieved by sequencing other highly variable genetic loci. The resulting data will convey whether isolates are different from each other or indistinguishable.
What is the difference between AccuGENX-ST® and AccuGENX-XGST®?
While both tests are used for strain typing, AccuGENX-XGST® can be used for specific organisms that have a published MLST scheme with defined alleles. The comparison report will include the allelic number for each gene sequenced and the strain type of the sample (if previously defined).
What are strain typing methods such as SLST and MLST used for?
Strain typing is a microbial characterization process that is used to distinguish members of the same species at the strain level. This technique is often used in contamination investigations to help find the root cause or source of a sterility failure or product contamination. Strain typing can also be used to confirm microbial production strain identities and to differentiate them from environmental contaminants.