bacteriocin
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Tailocins are nano-scale phage tail-like protein complexes that can mediate antagonistic interactions between closely related bacterial species. While the capacity to produce R-type tailocin was found widely across Gammaproteobacteria, the production of F-type tailocins seems comparatively rare. In this study, we examined the freshwater isolate, Pragia fontium 24613, which can produce both R- and F-type tailocins. We investigated their inhibition spectrum, focusing on clinically relevant enterobacteria, and identified the associated tailocin gene cluster. Transmission electron microscopy confirmed that inactivation of the tape measure protein within the tailocin cluster disrupted R-tailocin production. Comparative analysis of Budviciaceae gene clusters showed high conservation of R-type tailocin genes, whereas F-type tailocin genes were found in only a few species, with little conservation. Our findings indicate a high prevalence of bacteriocin production among underexplored Enterobacteriales species. Detected tailocins showed potential as antimicrobials targeting clinically significant pathogens.
A novel Gram-stain-negative, strictly aerobic, rod-shaped, light-yellow-pigmented, and chemo-organoheterotrophic bacterium, designated DF-77T, was isolated from dense mats of filamentous algae collected in March 2004 at Okinawa in Japan. The microorganism grew at 0-2.0% NaCl concentrations (w/v), pH 6.0-9.0, and 20-30 °C. The 16S rRNA gene sequence-based phylogenetic tree demonstrated that the strain DF-77T is a novel member of the family Flavobacteriaceae and was greatly related to Flagellimonas nanhaiensis SM1704T with sequence similarity of 95.5%. The main fatty acids were iso-C15:1 G, iso-C15:0, and iso-C17:0 3-OH, and the only isoprenoid quinone was menaquinone-6. The dominant polar lipids were phosphatidylethanolamine, two unidentified aminolipids, an unidentified phosphoaminolipid, and four unidentified lipids. The genome size of strain DF-77T was 3.60 Mbp with a DNA G + C content of 47.5%. The average nucleotide identity (ANI) value between the genomes of strain DF-77T and its closely related species was 69.8-70.7%. The digital DNA - DNA hybridization (dDDH) value of strain DF-77T with the strain of F. nanhaiensis SM1704T was 16.8%. The genome of the strain DF-77T revealed that it encoded several genes involved in bio-macromolecule degradation, indicating a high potential for producing industrially useful enzymes. Consequently, the strain is described as a new species in the genus Flagellimonas, for which the name Flagellimonas algarum sp. nov., is proposed with the type strain DF-77T (= KCTC 72791T = NBRC 114251T).
- MeSH
- DNA bakterií genetika chemie MeSH
- Flavobacteriaceae * klasifikace izolace a purifikace genetika MeSH
- fosfolipidy analýza MeSH
- fylogeneze MeSH
- genom bakteriální MeSH
- hybridizace nukleových kyselin MeSH
- mastné kyseliny analýza MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- techniky typizace bakterií MeSH
- vitamin K 2 analýza analogy a deriváty MeSH
- zastoupení bazí MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Japonsko MeSH
Článek se zaměřuje na rutinně nekultivovatelné treponemové infekce, které i nadále představují celosvětový problém. Pojednává o současných poznatcích v oblasti molekulární genetiky a zdůrazňuje důležitost implementace aktuálních výzkumů do dermatovenerologie. Soustředí se na využití metody PCR v diagnostice a propojení klinické medicínské praxe s vědeckými poznatky v oblasti molekulární genetiky u treponemových infekcí.
The article deals with routinely uncultivable treponemal infections that continue to be a global problem. The current knowledge in the field of molecular genetics is presented and the importance of implementing current research into dermatovenerology is emphasized. The article focuses on the use of the PCR method in diagnosis as well as on linking clinical medical practice with scientific knowledge in the field of molecular genetics in treponemal infections.
The ApxIVA protein belongs to a distinct class of a "clip and link" activity of Repeat-in-ToXin (RTX) exoproteins. Along with the three other pore-forming RTX toxins (ApxI, ApxII and ApxIII), ApxIVA serves as a major virulence factor of Actinobacillus pleuropneumoniae, the causative agent of porcine pneumonia. The gene encoding ApxIVA is located on a bicistronic operon downstream of the orf1 gene and is expressed exclusively under in vivo conditions. Both ApxIVA and ORF1 are essential for full virulence of A. pleuropneumoniae, but the molecular mechanisms by which they contribute to the pathogenicity are not yet understood. Here, we provide a comprehensive structural and functional analysis of ApxIVA and ORF1 proteins. Our findings reveal that the N-terminal segment of ApxIVA shares structural similarity with colicin M (ColM)-like bacteriocins and exhibits an antimicrobial activity. The ORF1 protein resembles the colicin M immunity protein (Cmi) and, like Cmi, is exported to the periplasm through its N-terminal signal peptide. Additionally, ORF1 can protect bacterial cells from the antimicrobial activity of ApxIVA, suggesting that ORF1 and ApxIVA function as an antibacterial toxin-immunity pair. Moreover, we demonstrate that fetal bovine serum could elicit ApxIVA and ORF1 production under in vitro conditions. These findings highlight the coordinated action of various RTX determinants, where the fine-tuned spatiotemporal production of ApxIVA may enhance the fitness of A. pleuropneumoniae, facilitating its invasion to a resident microbial community on the surface of airway mucosa.
- MeSH
- Actinobacillus pleuropneumoniae * genetika imunologie MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální proteiny * genetika metabolismus imunologie MeSH
- bakteriální toxiny genetika metabolismus imunologie MeSH
- faktory virulence genetika MeSH
- infekce bakteriemi rodu Actinobacillus mikrobiologie veterinární MeSH
- koliciny genetika metabolismus MeSH
- operon * MeSH
- prasata MeSH
- regulace genové exprese u bakterií MeSH
- virulence MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Three closely related, aerobic, Gram-stain-negative, motile, rod-shaped bacterial strains (PS-2T, PS-17, and PS-19) were isolated from the skin of freshwater pufferfish (Tetraodon cutcutia). Colonies are pinkish-colored. The optimum growth occurred at 28-30 °C, and the pH was 6.5-7. The major cellular fatty acids were C16:1 ω7c, iso-C15.0, C17:1 ω8c, C18:1 ω7c, and C16:0. The predominant polar lipids were phosphatidylglycerol, phosphatidylethanolamine, and amino lipids. The genome size of strain PS-2T is 4.8 Mbp, and the G + C content was 46.0%. The major fraction of genes were associated with biological processes (45.64%), followed by molecular function (29.86%) and cellular components (24.49%). The unique genes identified in strain PS-2T secreted cyanophycinase, UDP-N-acetylglucosamine 2-epimerase, methyltransferase, kynureninase, ADA regulatory protein, biphenyl degradation, thermostable carboxypeptidase 1, tetrathionate respiration, etc. In addition, alanine and glutamate racemases were present. The 16S rRNA gene sequences shared 98.83-99.24% similarity with the closely related type strains of Shewanella. The ANI and AAI of strain PS-2T with reference type strains of the genus Shewanella were below 95-96%, and the corresponding dDDH values were below 70%. A phylogenetic tree based on 16S rRNA gene sequences and genome-wide core genes revealed that strain PS-2T clustered with Shewanella oneidensis LMG 19005T in both phylogenetic trees. Based on the polyphasic analysis, the new isolates (PS-2T, PS-17, and PS-19) represent a novel species of Shewanella, for which Shewanella cutis sp. nov. is proposed. The type strain is PS-2T (= TBRC 15838T = NBRC 115342T).
- MeSH
- DNA bakterií * genetika MeSH
- fosfolipidy analýza MeSH
- fylogeneze * MeSH
- genom bakteriální * MeSH
- genomika MeSH
- kůže mikrobiologie MeSH
- mastné kyseliny * analýza MeSH
- RNA ribozomální 16S * genetika MeSH
- sekvenční analýza DNA MeSH
- Shewanella * genetika izolace a purifikace klasifikace MeSH
- sladká voda mikrobiologie MeSH
- techniky typizace bakterií MeSH
- Tetraodontiformes * mikrobiologie MeSH
- zastoupení bazí * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The taxonomic position of three actinobacterial strains, BCCO 10_0061T, BCCO 10_0798T, and BCCO 10_0856T, recovered from bare soil in the Sokolov Coal Basin, Czech Republic, was established using a polyphasic approach. The multilocus sequence analysis based on 100 single-copy genes positioned BCCO 10_0061T in the same cluster as Lentzea waywayandensis, strain BCCO 10_0798T in the same cluster as Lentzea flaviverrucosa, Lentzea californiensis, Lentzea violacea, and Lentzea albidocapillata, and strain BCCO 10_0856T clustered together with Lentzea kentuckyensis and Lentzea alba. Morphological and chemotaxonomic characteristics of these strains support their assignment to the genus Lentzea. In all three strains, MK-9(H4) accounted for more than 80 % of the isoprenoid quinone. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The whole-cell sugars were rhamnose, ribose, mannose, glucose, and galactose. The major fatty acids (>10 %) were iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0, and C16 : 0. The polar lipids were diphosphatidylglycerol, methyl-phosphatidylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylinositol. The genomic DNA G+C content of strains (mol%) was 68.8 for BCCO 10_0061T, 69.2 for BCCO 10_0798T, and 68.5 for BCCO 10_0856T. The combination of digital DNA-DNA hybridization results, average nucleotide identity values and phenotypic characteristics of BCCO 10_0061T, BCCO 10_0798T, and BCCO 10_0856T distinguishes them from their closely related strains. Bioinformatic analysis of the genome sequences of the strains revealed several biosynthetic gene clusters (BGCs) with identities >50 % to already known clusters, including BGCs for geosmin, coelichelin, ε-poly-l-lysine, and erythromycin-like BGCs. Most of the identified BGCs showed low similarity to known BGCs (<50 %) suggesting their genetic potential for the biosynthesis of novel secondary metabolites. Based on the above results, each strain represents a novel species of the genus Lentzea, for which we propose the name Lentzea sokolovensis sp. nov. for BCCO 10_0061T (=DSM 116175T), Lentzea kristufekii sp. nov. for BCCO 10_0798T (=DSM 116176T), and Lentzea miocenica sp. nov. for BCCO 10_0856T (=DSM 116177T).
- MeSH
- Actinobacteria * MeSH
- Actinomycetales * MeSH
- Bacteria MeSH
- DNA bakterií genetika MeSH
- fosfatidylethanolaminy MeSH
- fylogeneze MeSH
- mastné kyseliny chemie MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- techniky typizace bakterií MeSH
- uhlí MeSH
- zastoupení bazí MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Streptococcus pneumoniae (pneumokok) je grampozitivní kok vyvolávající jak neinvazivní, tak invazivní infekční onemocnění. Onemocnění vyvolaná pneumokokem mohou být preventabilní očkováním. Invazivní pneumokoková onemocnění (IPO) musí splňovat mezinárodní definici případu, jsou hlášena na národní i mezinárodní úrovni a v řadě zemí, včetně České republiky, jsou sledována v programu surveillance. Důležitou součástí surveillance IPO je sledování vyskytujících se sérotypů, hodnocení četnosti jednotlivých sérotypů v čase a v relaci k probíhajícím vakcinačním programům. Ve světe i v České republice je u pneumokoků stále častěji prováděna metoda celogenomové sekvenace (whole genome sequencing, WGS), která umožňuje určování sérotypu pneumokoků ze sekvenačních dat, dále přesnou analýzu jejich genetických vztahů a studium genů obsažených v jejich genomu. Celogenomová sekvenace umožňuje získávat spolehlivá a mezinárodně srovnatelná sekvenační data, která lze snadno sdílet. Sekvenační data jsou analyzována pomocí bioinformatických nástrojů, které vyžadují znalosti z oblasti přírodních věd s důrazem na genetiku a znalosti z oblasti bioinformatiky. V publikaci jsou představeny některé možnosti analýzy pneumokoka, kterými jsou sérotypizace, multilokusová sekvenační typizace (MLST), ribozomální MLST (rMLST), core genome MLST (cgMLST), whole genome MLST (wgMLST), single nucleotide polymorphism (SNP) analýza, určení Global Pneumococcal Sequence Cluster (GPSC), stanovení genů virulence a genů antibiotické rezistence. U metody WGS je prezentována strategie její aplikace v Evropě a realizace v praxi. Analýza pneumokoků metodou WGS představuje zlepšení v provádění surveillance IPO, kdy je sérotyp určován molekulárně geneticky, jsou prováděny další podrobnější typizace, získaná data lze snadno mezinárodně porovnávat a lze lépe hodnotit účinnost vakcinačních programů.
Streptococcus pneumoniae (pneumococcus) is a Gram-positive coccus causing both non-invasive and invasive infectious diseases. Pneumococcal diseases are vaccine preventable. Invasive pneumococcal diseases (IPD) meeting the international case definition are reported nationally and internationally and are subject to surveillance programmes in many countries, including the Czech Republic. An important part of IPD surveillance is the monitoring of causative serotypes and their frequency over time and in relation to ongoing vaccination programmes. In the world and in the Czech Republic, whole genome sequencing (WGS) is increasingly used for pneumococci, which allows for serotyping from sequencing data, precise analysis of their genetic relationships, and the study of genes present in their genome. Whole-genome sequencing enables the generation of reliable and internationally comparable data that can be easily shared. Sequencing data are analysed using bioinformatics tools that require knowledge in the field of natural sciences with an emphasis on genetics and expertise in bioinformatics. This publication presents some options for pneumococcal analysis, i.e., serotyping, multilocus sequence typing (MLST), ribosomal MLST (rMLST), core genome MLST (cgMLST), whole genome MLST (wgMLST), single nucleotide polymorphism (SNP) analysis, assignment to Global Pneumococcal Sequence Cluster (GPSC), and identification of virulence genes and antibiotic resistance genes. The WGS strategies and applications for Europe and WGS implementation in practice are presented. WGS analysis of pneumococci allows for improved IPD surveillance, thanks to molecular serotyping, more detailed typing, generation of internationally comparable data, and improved evaluation of the effectiveness of vaccination programmes.
- MeSH
- molekulární biologie metody MeSH
- multilokusová sekvenční typizace klasifikace metody MeSH
- pneumokokové infekce mikrobiologie MeSH
- sekvenování celého genomu * metody normy MeSH
- séroskupina MeSH
- sérotypizace klasifikace metody MeSH
- Streptococcus pneumoniae * genetika izolace a purifikace MeSH
- techniky typizace bakterií klasifikace MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Fonticins are phage tail-like bacteriocins produced by the Gram-negative bacterium Pragia fontium from the family Budviciaceae. This bacterium produces contractile-type particles that adsorb on the surface of sensitive bacteria and penetrate the cell wall, probably during contraction, in a way similar to the type VI secretion system. We characterized the pore-forming activity of fonticins using both living cells and in vitro model membranes. Using a potassium leakage assay, we show that fonticins are able to permeabilize sensitive cells. On black lipid membranes, single-pore conductance is about 0.78 nS in 1 M NaCl and appears to be linearly dependent on the increasing molar strength of NaCl solution, which is a property of considerably large pores. In agreement with these findings, fonticins are not ion selective for Na+, K+, and Cl-. Polyethylene glycol 3350 (PEG 3350) molecules of about 3.5 nm in diameter can enter the fonticin pore lumen, whereas the larger molecules cannot pass the pore. The size of fonticin pores was confirmed by transmission electron microscopy. The terminal membrane-piercing complex of the fonticin tube probably creates a selective barrier restricting passage of macromolecules. IMPORTANCE Phage tail-like bacteriocins are now the subject of research as potent antibacterial agents due to their narrow host specificity and single-hit mode of action. In this work, we focused on the structure and mode of action of fonticins. According to some theories, related particles were initially adapted for passage of double-stranded DNA (dsDNA) molecules, but fonticins changed their function during the evolution; they are able to form large pores through the bacterial envelope of Gram-negative bacteria. As various pore-forming proteins are extensively used for nanopore sequencing and stochastic sensing, we decided to investigate the pore-forming properties of fonticin protein complexes on artificial lipid membranes. Our research revealed remarkable structural properties of these particles that may have a potential application as a nanodevice.
In the present work, we characterized in detail strain CM-3-T8T, which was isolated from the rhizosphere soil of strawberries in Beijing, China, in order to elucidate its taxonomic position. Cells of strain CM-3-T8T were Gram-negative, non-spore-forming, aerobic, short rod. Growth occurred at 25-37 °C, pH 5.0-10.0, and in the presence of 0-8% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CM-3-T8T formed a stable clade with Lysobacter soli DCY21T and Lysobacter panacisoli CJ29T, with the 16S rRNA gene sequence similarities of 98.91% and 98.50%. The average nucleotide identity and digital DNA-DNA hybridization values between strain SG-8 T and the two reference type strains listed above were 76.3%, 79.6%, and 34.3%, 27%, respectively. The DNA G + C content was 68.4% (mol/mol). The major cellular fatty acids were comprised of C15:0 iso (36.15%), C17:0 iso (8.40%), and C11:0 iso 3OH (8.28%). The major quinone system was ubiquinone Q-8. The major polar lipids were phosphatidylethanolamine (PE), phosphatidylethanolamine (PME), diphosphatidylglycerol (DPG), and aminophospholipid (APL). On the basis of phenotypic, genotypic, and phylogenetic evidence, strain CM-3-T8T (= ACCC 61714 T = JCM 34576 T) represents a new species within the genus Lysobacter, for which the name Lysobacter changpingensis sp. nov. is proposed.
- MeSH
- DNA bakterií genetika chemie MeSH
- fosfatidylethanolaminy MeSH
- fosfolipidy chemie MeSH
- fylogeneze MeSH
- jahodník * genetika MeSH
- Lysobacter * genetika MeSH
- mastné kyseliny analýza MeSH
- půda MeSH
- rhizosféra MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- techniky typizace bakterií MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Čína MeSH
Lactobacillus plantarum NMD-17 separated from koumiss could produce a bacteriocin named plantaricin MX against Gram-positive bacteria and Gram-negative bacteria. The bacteriocin synthesis of L. plantarum NMD-17 was remarkably induced in co-cultivation with Lactobacillus reuteri NMD-86 as the increase of cell numbers and AI-2 activity, and the expressions of luxS encoding signal AI-2 synthetase, plnB encoding histidine protein kinase, plnD encoding response regulator, and plnE and plnF encoding structural genes of bacteriocin were significantly upregulated in co-cultivation, showing that the bacteriocin synthesis of L. plantarum NMD-17 in co-cultivation may be regulated by LuxS/AI-2-mediated quorum sensing system. In order to further demonstrate the role of LuxS/AI-2-mediated quorum sensing system in the bacteriocin synthesis of L. plantarum NMD-17, plasmids pUC18 and pMD18-T simple were used as the skeleton to construct the suicide plasmids pUC18-UF-tet-DF and pMD18-T simple-plnB-tet-plnD for luxS and plnB-plnD gene deletion, respectively. luxS and plnB-plnD gene knockout mutants were successfully obtained by homologous recombination. luxS gene knockout mutant lost its AI-2 synthesis ability, suggesting that LuxS protein encoded by luxS gene is key enzyme for AI-2 synthesis. plnB-plnD gene knockout mutant lost the ability to synthesize bacteriocin against Salmonella typhimurium ATCC14028, indicating that plnB-plnD gene was a necessary gene for bacteriocin synthesis of L. plantarum NMD-17. Bacteriocin synthesis, cell numbers, and AI-2 activity of luxS or plnB-plnD gene knockout mutants in co-cultivation with L. reuteri NMD-86 were obviously lower than those of wild-type strain in co-cultivation at 6-9 h (P < 0.01). The results showed that LuxS/AI-2-mediated quorum sensing system played an important role in the bacteriocin synthesis of L. plantarum NMD-17 in co-cultivation.
