Sekvenování genů 16S, 18S a ITS regionů se stalo jedním z nejdůležitějších nástrojů v molekulární diagnostice, zejména v oblasti mikrobiologie, patologie a soudního lékařství. Výše zmíněné geny, obsahující konzervované i variabilní oblasti, jsou hojně využívány pro taxonomické zařazení bakterií a eukaryot. Sekvenování 16S rDNA umožňuje detekci bakteriálních infekcí, zatímco sekvenace ITS regionů a 18S rDNA je využívána při identifikaci mykotických, případně parazitárních infekcí, a to především v případech, kdy tradiční metody selhávají. Tento článek se zaměřuje na rozšířené možnosti těchto metod, jejich uplatnění v klinické diagnostice a výzkumu, zkoumá výhody a nevýhody, a diskutuje potenciální budoucí vývoj v oblasti technologie sekvenování nové generace (NGS).
Gene sequencing of 16S, 18S, and ITS regions is a crucial tool in molecular diagnostics, especially in microbiology, pathology and forensic medicine. These genes contain conserved and variable regions and are widely used for the taxonomic classification of bacteria and eukaryotes. Sequencing of 16S rDNA helps detect bacterial infections, while sequencing of ITS regions and 18S rDNA is used to identify fungal or parasitic infections, especially when traditional methods are ineffective. This article focuses on the expanded possibilities of these methods, their application in clinical diagnostics and research, their advantages and disadvantages, and discusses potential future developments in the field of next-generation sequencing (NGS) technology.
- Keywords
- Internal Transcribed Spacers, 16S rDNA, 18S rDNA,
- MeSH
- Molecular Diagnostic Techniques classification methods MeSH
- DNA, Bacterial analysis genetics classification MeSH
- DNA analysis genetics classification ultrastructure MeSH
- Communicable Diseases * diagnosis genetics MeSH
- Humans MeSH
- High-Throughput Nucleotide Sequencing * classification methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
BACKGROUND: Distribution and evolutionary history of resistance genes in environmental actinobacteria provide information on intensity of antibiosis and evolution of specific secondary metabolic pathways at a given site. To this day, actinobacteria producing biologically active compounds were isolated mostly from soil but only a limited range of soil environments were commonly sampled. Consequently, soil remains an unexplored environment in search for novel producers and related evolutionary questions. RESULTS: Ninety actinobacteria strains isolated at contrasting soil sites were characterized phylogenetically by 16S rRNA gene, for presence of erm and ABC transporter resistance genes and antibiotic production. An analogous analysis was performed in silico with 246 and 31 strains from Integrated Microbial Genomes (JGI_IMG) database selected by the presence of ABC transporter genes and erm genes, respectively. In the isolates, distances of erm gene sequences were significantly correlated to phylogenetic distances based on 16S rRNA genes, while ABC transporter gene distances were not. The phylogenetic distance of isolates was significantly correlated to soil pH and organic matter content of isolation sites. In the analysis of JGI_IMG datasets the correlation between phylogeny of resistance genes and the strain phylogeny based on 16S rRNA genes or five housekeeping genes was observed for both the erm genes and ABC transporter genes in both actinobacteria and streptomycetes. However, in the analysis of sequences from genomes where both resistance genes occurred together the correlation was observed for both ABC transporter and erm genes in actinobacteria but in streptomycetes only in the erm gene. CONCLUSIONS: The type of erm resistance gene sequences was influenced by linkage to 16S rRNA gene sequences and site characteristics. The phylogeny of ABC transporter gene was correlated to 16S rRNA genes mainly above the genus level. The results support the concept of new specific secondary metabolite scaffolds occurring more likely in taxonomically distant producers but suggest that the antibiotic selection of gene pools is also influenced by site conditions.
- MeSH
- ATP-Binding Cassette Transporters genetics MeSH
- Actinobacteria classification drug effects genetics isolation & purification MeSH
- Anti-Bacterial Agents biosynthesis MeSH
- Drug Resistance, Bacterial * MeSH
- Phylogeny * MeSH
- Genes, rRNA MeSH
- Methyltransferases genetics MeSH
- Molecular Sequence Data MeSH
- Soil Microbiology MeSH
- DNA, Ribosomal chemistry genetics MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Sequence Analysis, DNA MeSH
- Cluster Analysis MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The genes of ribosomal RNA are the most popular and frequently used markers for bacterial phylogeny and reconstruction of insect-symbiont coevolution. In primary symbionts, such as Buchnera and Wigglesworthia, genome economization leads to the establishment of a single copy of these sequences. In phylogenetic studies, they provide sufficient information and yield phylogenetic trees congruent with host evolution. In contrast, other symbiotic lineages (e.g., the genus Arsenophonus) carry a higher number of rRNA copies in their genomes, which may have serious consequences for phylogenetic inference. In this study, we show that in Arsenophonus triatominarum the degree of heterogeneity can affect reconstruction of phylogenetic relationships and mask possible coevolution between the symbiont and its host. Phylogenetic arrangement of individual rRNA copies was used, together with a calculation of their divergence time, to demonstrate that the incongruent 16S rDNA trees and low nucleotide diversity in the secondary symbiont could be reconciled with the coevolutionary scenario.
- MeSH
- DNA, Bacterial genetics chemistry MeSH
- Enterobacteriaceae genetics isolation & purification classification MeSH
- Financing, Organized MeSH
- Phylogeny MeSH
- DNA, Ribosomal Spacer genetics chemistry MeSH
- Evolution, Molecular MeSH
- Molecular Sequence Data MeSH
- Polymorphism, Genetic MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Base Sequence MeSH
- Sequence Analysis, DNA MeSH
- Sequence Alignment MeSH
- Triatoma microbiology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
A total of 151 bacterial isolates were recovered from different developmental stages (larvae, nymphs and adults) of field-collected ticks (67 strains from Ixodes ricinus, 38 from Dermacentor reticulatus, 46 from Haemaphysalis concinna). Microorganisms were identified by means of 16S rRNA gene sequencing. Almost 87 % of the strains belonged to G(+) bacteria with predominantly occurring genera Bacillus and Paenibacillus. Other G(+) strains included Arthrobacter, Corynebacterium, Frigoribacterium, Kocuria, Microbacterium, Micrococcus, Plantibacter, Rhodococcus, Rothia, and Staphylococcus. G(-) strains occurred less frequently, comprising genera Advenella, Pseudomonas, Rahnella, Stenotrophomonas, and Xanthomonas. Several strains of medical importance were found, namely Advenella incenata, Corynebacterium aurimucosum, Microbacterium oxydans, M. schleiferi, Staphylococcus spp., and Stenotrophomonas maltophilia. Data on cultivable microbial diversity in Eurasian tick species D. reticulatus and H. concinna are given, along with the extension of present knowledge concerning bacterial flora of I. ricinus.
- MeSH
- Arachnid Vectors microbiology parasitology growth & development MeSH
- Bacteria genetics isolation & purification classification MeSH
- DNA, Bacterial genetics MeSH
- Financing, Organized MeSH
- Phylogeny MeSH
- Tick Infestations parasitology MeSH
- Ixodidae microbiology parasitology growth & development MeSH
- Molecular Sequence Data MeSH
- Vertebrates parasitology MeSH
- DNA, Ribosomal genetics MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Bacterial Typing Techniques MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
PCR-primers were designed for identification of strictly anaerobic bacteria of the genus Zymophilus based on genus-specific sequences of the 16S-23S rDNA internal transcribed spacer region. The specificity of the primers was tested against 37 brewery-related non-target microorganisms that could potentially occur in the same brewery specimens. None DNA was amplified from any of the non-Zymophilus strains tested including genera from the same family (Pectinatus, Megasphaera, Selenomonas), showing thus 100% specificity. PCR assay developed in this study allows an extension of the spectra of detected beer spoilage microorganisms in brewery laboratories.
- MeSH
- Anaerobiosis MeSH
- Bacteria, Anaerobic classification genetics metabolism MeSH
- DNA, Intergenic chemistry genetics MeSH
- Molecular Sequence Data MeSH
- Polymerase Chain Reaction MeSH
- RNA, Ribosomal chemistry genetics MeSH
- Base Sequence MeSH
- Sequence Alignment MeSH
- Sensitivity and Specificity MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Lactobacillus pobuzihii is a novel species which has been previously found in pobuzihi (fermented cummingcordia), a traditional fermented food in Taiwan. However, the lactic acid bacteria (LAB) microflora in pobuzihi has not been studied in detail. In this study, LAB from pobuzihi were isolated, identified, and characterized. A total of 196 LAB were isolated; 79 cultures were isolated from the sample collected from a manufacturing factory, 38 from pobuzihi samples collected from 4 different markets, and 79 from 2 fresh cummingcordia samples. These isolates were characterized phenotypically and then divided into eight groups (A to H) by restriction fragment length polymorphism analysis and sequencing of 16S ribosomal DNA. Lactobacillus plantarum was the most abundant LAB found in most samples during the fermentation of pobuzihi. On the other hand, Enterococcus casseliflavus and Weissella cibaria were, respectively, the major species found in the two fresh cummingcordia samples. A potential novel species or subspecies of lactococcal strain was found. In addition, seven L. plantarum and five W. cibaria strains showed inhibitory activity against the indicator strain Lactobacillus sakei JCM 1157(T). This is the first report describing the distribution and varieties of LAB existing in the pobuzihi during its fermentation process and the final product on the market.
- MeSH
- Biodiversity * MeSH
- DNA, Bacterial chemistry genetics MeSH
- Fermentation MeSH
- Lactobacillales classification genetics isolation & purification MeSH
- Molecular Sequence Data MeSH
- Polymorphism, Restriction Fragment Length MeSH
- Food Microbiology * MeSH
- DNA, Ribosomal chemistry genetics MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Sequence Analysis, DNA MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Taiwan MeSH
Based on 16S rDNA analyses, the primary symbionts of sucking lice were found to form a polyphyletic assemblage of several distant lineages that have arisen several times within Enterobacteriaceae and at least once within Legionellaceae. Another independent lineage of endosymbiotic enterobacteria inhabits a sister group of the sucking lice, Rhynchophthirina. The inspection of 16S rDNA supports the symbiotic nature of the investigated bacteria; they display a typical trait of degenerative processes, an increased AT content (Adenine-Thymine content) in comparison with free-living bacteria. The calculation of divergence time between the closest anopluran and rhynchophthirine symbionts further support their independent origin. The results shown here, together with evidence from other groups, indicate that the significance of primary symbionts for blood-feeding insects should be reconsidered.
- MeSH
- Bacteria genetics classification MeSH
- Financing, Organized MeSH
- Bacterial Physiological Phenomena MeSH
- DNA, Mitochondrial MeSH
- Phthiraptera physiology genetics microbiology MeSH
- DNA, Ribosomal genetics MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Base Sequence MeSH
- Symbiosis MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
The class Eustigmatophyceae includes mostly coccoid, freshwater algae, although some genera are common in terrestrial habitats and two are primarily marine. The formal classification of the class, developed decades ago, does not fit the diversity and phylogeny of the group as presently known and is in urgent need of revision. This study concerns a clade informally known as the Pseudellipsoidion group of the order Eustigmatales, which was initially known to comprise seven strains with oval to ellipsoidal cells, some bearing a stipe. We examined those strains as well as 10 new ones and obtained 18S rDNA and rbcL gene sequences. The results from phylogenetic analyses of the sequence data were integrated with morphological data of vegetative and motile cells. Monophyly of the Pseudellipsoidion group is supported in both 18S rDNA and rbcL trees. The group is formalized as the new family Neomonodaceae comprising, in addition to Pseudellipsoidion, three newly erected genera. By establishing Neomonodus gen. nov. (with type species Neomonodus ovalis comb. nov.), we finally resolve the intricate taxonomic history of a species originally described as Monodus ovalis and later moved to the genera Characiopsis and Pseudocharaciopsis. Characiopsiella gen. nov. (with the type species Characiopsiella minima comb. nov.) and Munda gen. nov. (with the type species Munda aquilonaris) are established to accommodate additional representatives of the polyphyletic genus Characiopsis. A morphological feature common to all examined Neomonodaceae is the absence of a pyrenoid in the chloroplasts, which discriminates them from other morphologically similar yet unrelated eustigmatophytes (including other Characiopsis-like species).
This study describes the taxonomic diversity of pigmented, agar-degrading bacteria isolated from the surface of macroalgae collected in King George Island, Antarctica. A total of 30 pigmented, agarolytic bacteria were isolated from the surface of the Antarctic macroalgae Adenocystis utricularis, Monostroma hariotii, Iridaea cordata, and Pantoneura plocamioides. Based on the 16S rRNA data, the agarolytic isolates were affiliated to the genera Algibacter, Arthrobacter, Brachybacterium, Cellulophaga, Citricoccus, Labedella, Microbacterium, Micrococcus, Salinibacterium, Sanguibacter, and Zobellia. Isolates phylogenetically related to Cellulophaga algicola showed the highest agarase activity in culture supernatants when tested at 4 and 37 °C. This is the first investigation of pigmented agar-degrading bacteria, members of microbial communities associated with Antarctic macroalgae, and the results suggest that they represent a potential source of cold-adapted agarases of possible biotechnological interest.
- MeSH
- Agar metabolism MeSH
- Bacteria classification genetics isolation & purification metabolism MeSH
- Pigments, Biological analysis MeSH
- DNA, Bacterial chemistry genetics MeSH
- Seaweed microbiology MeSH
- DNA, Ribosomal chemistry genetics MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Sequence Analysis, DNA MeSH
- Temperature MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Antarctic Regions MeSH
