The paper is aimed to identify SNP in Sarcandra glabra and Chloranthus spicatus, and authenticate S. glabra from Ch. spicatus and the mixture by using PCR amplification of specific alleles. SNPs in the ITS sequences of S. glabra and Ch. spicatus were found by ClustulX 2. 1 program and Bioedit software. Primers for authentic S. glabra and Ch. spicatus was designed according to the SNP site, and ITS sequence universal primers plus to the authentic primer to construct a multi-PCR reaction system, and then optimized the PCR reaction system. Five hundred and eighty band special for S. glabra and 470 bp band special for Ch. spicatus were found by using multi-PCR reaction. The multi-PCR reaction system could be applied to identify S. glabra and Ch. spicatus's leaves.
DNA, Plant ; analysis ; genetics ; DNA, Ribosomal ; genetics ; DNA, Ribosomal Spacer ; analysis ; genetics ; Magnoliopsida ; classification ; genetics ; Plant Leaves ; genetics ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; RNA, Ribosomal ; genetics ; RNA, Ribosomal, 18S ; genetics ; RNA, Ribosomal, 5.8S ; genetics ; Species Specificity

OBJECTIVETo type and group the Yersinia pestis strains isolated in China to clarify the geographical distribution of ribotypes of Yersinia pestis.

METHODSGenomic DNA of Yersinia pestis were digested with EcoR I, then hybridized with 16s-23s-5s rRNA gene probe.

RESULTSThese tested strains were divided into 3 ribotypes, the profiles obtained were relatively homogeneous, with most of them differed only by the presence or the absence of 1 - 2 restriction fragments. Ribotype A and B were the most common types, which distributed in a large area in China while ribotype C was the least, only limited to a small area. There was certain correlation between the ribotypes and the plague foci, usually only one ribotype was found in one plague foci.

CONCLUSIONThe ribotypes were stable in the plague foci. Correlation between the ribotypes of Yersinia pestis strains and their geographical origins was noticed. All 3 ribotypes had different origins, however ribotype A and ribotype C seemed to be closer related.

China ; DNA, Bacterial ; genetics ; Geography ; RNA, Ribosomal, 16S ; genetics ; RNA, Ribosomal, 23S ; genetics ; RNA, Ribosomal, 5S ; genetics ; Ribotyping ; Yersinia pestis ; classification ; genetics

Microorganisms are the dominant players driving the degradation and transformation of chloramphenicol (CAP) in the environment. However, little bacterial strains are able to efficiently degrade and mineralize CAP, and the CAP degrading pathways mediated by oxidative reactions remain unclear. In this study, a highly efficient CAP-degrading microbial consortium, which mainly consists of Rhodococcus (relative abundance >70%), was obtained through an enrichment process using CAP-contaminated activated sludge as the inoculum. A bacterial strain CAP-2 capable of efficiently degrading CAP was isolated from the consortium and identified as Rhodococcus sp. by 16S rRNA gene analysis. Strain CAP-2 can efficiently degrade CAP under different nutrient conditions. Based on the biotransformation characteristics of the detected metabolite p-nitrobenzoic acid and the reported metabolites p-nitrobenzaldehyde and protocatechuate by strain CAP-2, a new oxidative pathway for the degradation of CAP was proposed. The side chain of CAP was oxidized and broken to generate p-nitrobenzaldehyde, which was further oxidized to p-nitrobenzoic acid. Strain CAP-2 can be used to further study the molecular mechanism of CAP catabolism, and has the potential to be used in in situ bioremediation of CAP-contaminated environment.
Biodegradation, Environmental ; Chloramphenicol ; RNA, Ribosomal, 16S/genetics* ; Rhodococcus/genetics* ; Sewage

Objective To describe the microbiological characteristics of ()CGMCC 12426 and determine and analyze its complete genome sequences.Methods strain CGMCC 12426 genomic DNA sequencing was performed on a single molecule real-time sequencing(SMRT)platform and the annotation was completed in the NCBI Prokaryotic Genomic Annotation Pipeline(pGAP).Results The complete genomic sequences of the released CGMCC 12426 consisted of a 4 138 265-bp circular chromosome and a 74 165-bp plasmid,which resulted in the prediction of 4581 genes including 4222 coding sequences,87 tRNAs,and 30 rRNAs(which included 5S rRNA,16S rRNA,and 23S rRNA).Conclusion The genome sequencing provided a basis for further investigations on the genetic background of and on the metabolic and regulatory mechanisms.
Bacillus subtilis ; genetics ; Genome, Bacterial ; Plasmids ; RNA, Ribosomal, 16S ; genetics ; RNA, Ribosomal, 23S ; genetics ; RNA, Ribosomal, 5S ; genetics ; Sequence Analysis, DNA

Objective To detect the diatom population diversity in Dianchi by constructing a 18S rDNA clone library. Methods DNA from diatoms in 6 water samples of Dianchi was amplified with diatom 18S rDNA specific primer.The 18S rDNA clone library was constructed, and clones were randomly selected for sequence. Sequence alignment was performed by BLAST. The diatom population distribution in Dianchi was analyzed and the phylogenetic tree of diatom 18S rDNA in Dianchi waters was established with the MEGA v7.0.14 software. Results Two hundred and forty clones were sequenced, with 167 diatom sequences obtained, including 11 diatom species such as Stephanodiscus, Diatoma, and Melosira. There were certain differences in diatom population distribution among the 6 samples. Conclusion The population distribution of diatom species in Dianchi shows unique features and the sequence analysis of diatom 18S rDNA has a certain reference value to the inference of forensic drowning sites.
China ; DNA, Ribosomal/genetics* ; Diatoms/classification* ; Drowning ; Forensic Sciences ; Humans ; Phylogeny ; RNA, Ribosomal, 18S/genetics*

OBJECTIVETo investigated the genetic polymorphism of the isolated strains using ribotyping method.

METHODSOne hundred twenty-two strains of V. cholerae O139 isolated from different areas of China from 1993 to 1999 were selected and characterized with ribotyping, including 16s rDNA and 23s rDNA probes.

RESULTSOne hundred twenty-two strains were differentiated into 10 different ribotypes (RT1-RT10) on the basis of rRNA gene probes hybridization (with Bgl I digestion), which consisted of 7 - 9 bands between 12 and 1.5 kb in size. RT1 and RT3, as two predominant ribotypes, comprised most number of the strains which spread to the extensive range. Nine strains, which are negative to ctxAB, zot and RS individually, belong to 4 special ribotypes. The dendrogram revealing genetic relationship among different clones of V. cholerae O139 showed that the clones belonging to RT1 and RT2 had genetic similarity on high degree, although they were isolated from different regions. The two predominant ribotypes (RT1 and RT3) were distant in genetic relationship.

CONCLUSIONResults showed the clonal diversity and the wide area distribution of V. cholerae O139 strains in China, suggesting the multiple origins of O139 epidemics.

Phylogeny ; Polymorphism, Genetic ; RNA, Ribosomal, 16S ; genetics ; RNA, Ribosomal, 23S ; genetics ; Ribotyping ; Species Specificity ; Vibrio cholerae O139 ; classification ; genetics

The 16S rRNA gene is the most commonly used molecular marker for identifying microorganisms. It is used in sequencing technology, including the first-generation, the second-generation, and the third-generation sequencing technology. A large number of studies on the 16S rRNA gene have contributed to a deeper understanding of oral microbial diversity. In the healthy oral cavity, there is microbial diversity in time and space. With the occurrence or development of oral diseases such as caries, periodontal disease, or halitosis, the microbial diversity will be changed.
High-Throughput Nucleotide Sequencing ; Mouth ; RNA, Ribosomal, 16S ; genetics

We report an important but long-overlooked manifestation of low-resolution power of 16S rRNA sequence analysis at the species level, namely, in 16S rRNA-based phylogenetic trees polyphyletic placements of closely-related species are abundant compared to those in genome-based phylogeny. This phenomenon makes the demarcation of genera within many families ambiguous in the 16S rRNA-based taxonomy. In this study, we reconstructed phylogenetic relationship for more than ten thousand prokaryote genomes using the CVTree method, which is based on whole-genome information. And many such genera, which are polyphyletic in 16S rRNA-based trees, are well resolved as monophyletic clusters by CVTree. We believe that with genome sequencing of prokaryotes becoming a commonplace, genome-based phylogeny is doomed to play a definitive role in the construction of a natural and objective taxonomy.
Genome ; Genomics ; Phylogeny ; RNA, Ribosomal, 16S ; genetics ; Sequence Analysis, DNA

Microbiome is associated with a wide range of diseases. The gut microbiome is also a dynamic reflection of health status, which can be modified, thus representing great potential to exploit the mechanisms that influence human physiology. Recent years have seen a dramatic rise in gut microbiome studies, which has been enabled by the rapidly evolving high-throughput sequencing methods (i.e. 16S rRNA sequencing and shotgun sequencing). As the emerging technologies for microbiome research continue to evolve (i.e. metatranscriptomics, metabolomics, culturomics, synthetic biology), microbiome research has moved beyond phylogenetic descriptions and towards mechanistic analyses. In this review, we highlight different approaches to study the microbiome, in particular, the current limitations and future promise of these techniques. This review aims to provide clinicians with a framework for studying the microbiome, as well as to accelerate the adoption of these techniques in clinical practice.
Humans ; Gastrointestinal Microbiome ; Phylogeny ; RNA, Ribosomal, 16S/genetics* ; Health Status

The taxonomy of Acanthamoeba spp., an amphizoic amoeba which causes granulomatous amoebic encephalitis and chronic amoebic keratitis, has been revised many times. The taxonomic validity of some species has yet to be assessed. In this paper, we analyzed the morphological characteristics, nuclear 18s rDNA and mitochondrial 16s rDNA sequences and the Mt DNA RFLP of the type strains of four Acanthamoeba species, which had been previously designated as A. divionensis, A. parasidionensis, A. mauritaniensis, and A. rhysodes. The four isolates revealed characteristic group II morphology. They exhibited 18S rDNA sequence differences of 0.2-1.1% with each other, but more than 2% difference from the other compared reference strains. Four isolates formed a different clade from that of A. castellanii Castellani and the other strains in morphological group II on the phylogenetic tree. In light of these results, A. paradivionensis, A. divionensis, and A. mauritaniensis should be regarded as synonyms for A. rhysodes.
Acanthamoeba/*classification/*genetics ; Animals ; DNA, Mitochondrial/genetics ; DNA, Ribosomal/genetics ; Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 18S/genetics