-
Microbiology Spectrum Mar 2019Bacteria use a variety of mechanisms to translocate proteins from the cytoplasm, where they are synthesized, to the cell surface or extracellular environment or directly... (Review)
Review
Bacteria use a variety of mechanisms to translocate proteins from the cytoplasm, where they are synthesized, to the cell surface or extracellular environment or directly into other cells, where they perform their ultimate functions. Type V secretion systems (T5SS) use β-barrel transporter domains to export passenger domains across the outer membranes of Gram-negative bacteria. Distinct among T5SS are type Vb or two-partner secretion (TPS) systems in which the transporter and passenger are separate proteins, necessitating a mechanism for passenger-translocator recognition in the periplasm and providing the potential for reuse of the translocator. This review describes current knowledge of the TPS translocation mechanism, using filamentous hemagglutinin (FHA) and its transporter FhaC as a model. We present the hypothesis that the TPS pathway may be a general mechanism for contact-dependent delivery of toxins to target cells.
Topics: Adhesins, Bacterial; Bacterial Outer Membrane Proteins; Bordetella; Bordetella pertussis; Gram-Negative Bacteria; Hemagglutinins; Membrane Transport Proteins; Models, Molecular; Secretory Pathway; Type V Secretion Systems; Virulence; Virulence Factors, Bordetella; Whooping Cough
PubMed: 30927348
DOI: 10.1128/microbiolspec.PSIB-0024-2018 -
Journal of Clinical Microbiology Dec 2020Detection of and using molecular methods is sensitive and specific with a short turnaround time compared to other diagnostic methods. In this multicenter study, we...
Detection of and using molecular methods is sensitive and specific with a short turnaround time compared to other diagnostic methods. In this multicenter study, we compared the performance of the Simplexa Bordetella Direct kit to those of other molecular assays in detecting and differentiating and in nasopharyngeal swab specimens. The limits of detection (LODs) were 150 CFU/ml or 3 fg/μl of DNA for and 1,500 CFU/ml or 10 fg/μl of DNA for A total of 1,103 fresh and residual frozen specimens from eight clinical sites were tested. Combining the data from individual clinical sites using different comparative assays, the overall positive percent agreement (PPA) and negative percent agreement (NPA) for were 98.7% and 97.3%, respectively. The overall PPA and NPA for were 96.7% and 100%, respectively. For prospective fresh specimens, the overall PPA and NPA for both targets were 97.7% and 99.3%, respectively. For retrospective frozen specimens, the overall PPA and NPA for both targets were 92.6% and 93.2%, respectively. The percentage of invalid results was 1.0%. A cross-reactivity study using 74 non- bacterial species and five yeast species revealed that the Simplexa Bordetella Direct kit was 100% specific. The hands-on time and assay run time of the Simplexa Bordetella Direct kit are favorable compared to those of other commercial and laboratory-developed tests. In summary, the Simplexa Bordetella Direct kit has a performance comparable to those of other molecular assays for the detection of and .
Topics: Bordetella; Bordetella Infections; Bordetella parapertussis; Bordetella pertussis; Humans; Nasopharynx; Prospective Studies; Retrospective Studies; Whooping Cough
PubMed: 33055187
DOI: 10.1128/JCM.01041-20 -
International Journal of Systematic and... May 2024A Gram-stain-negative bacterium, designated LG-2, was isolated from sludge collected at a pesticide-manufacturing factory in Jiangsu Province, PR China. Cells of strain...
A Gram-stain-negative bacterium, designated LG-2, was isolated from sludge collected at a pesticide-manufacturing factory in Jiangsu Province, PR China. Cells of strain LG-2 were strictly aerobic, non-motile and spherical. Growth was observed at 15-42 °C (optimum, 30 °C), pH 6.0-9.0 (optimum, pH 7.0) and 0-3.0 % (w/v) NaCl (optimum, 1.0 %). LG-2 showed 95.5-96.9 % 16S rRNA sequence similarity to type strains in the genera , , , and of the family . The phylogenomic tree indicated that strain LG-2 was clustered in the family and formed a clade with IMT-305, while the phylogenetic trees based on 16S rRNA gene sequences indicated that strain LG-2 formed a distinct clade within the family . The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between LG-2 and its closely related type strains in the genera , , , and were 70.8-75.3, 18.9-23.7 and 59.6 %-69.3 %, respectively. The major cellular fatty acids were C, C cyclo, summed feature 3 (C ω7 and/or C ω6), summed feature 8 (C ω7 and/or C ω6) and summed feature 2 (C aldehyde and/or unknown 10.928). The predominant menaquinone was Q-8. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, two aminophospholipids, three aminolipids and nine unknown polar lipids. The genome size of strain LG-2 was 3.2 Mb and the DNA G+C content was 63.4 mol%. On the basis of the phenotypic, phylogenetic and genomic results from this study, strain LG-2 represents a novel species of a new genus in the family , for which the name gen. nov., sp. nov. is proposed, with strain LG-2 (=KCTC 8084= CCTCC AB 2023123) as the type strain.
Topics: Phylogeny; RNA, Ribosomal, 16S; Fatty Acids; DNA, Bacterial; Base Composition; Bacterial Typing Techniques; China; Nucleic Acid Hybridization; Sequence Analysis, DNA; Sewage; Alcaligenaceae; Pesticides; Vitamin K 2
PubMed: 38767617
DOI: 10.1099/ijsem.0.006394 -
International Journal of Systematic and... Apr 2022Strain NGK35 is a motile, Gram-stain-negative, rod-shaped (1.0-2.1 µm long and 0.6-0.8 µm wide), aerobic bacterium that was isolated from plastic-polluted landfill...
Strain NGK35 is a motile, Gram-stain-negative, rod-shaped (1.0-2.1 µm long and 0.6-0.8 µm wide), aerobic bacterium that was isolated from plastic-polluted landfill soil. The strain grew at temperatures between 6 and 37 °C (optimum, 28 °C), in 0-10 % NaCl (optimum, 1 %) and at pH 6.0-9.5 (optimum, pH 7.5-8.5). It was positive for cytochrome c oxidase, catalase as well as HS production, and hydrolysed casein and urea. It used a variety of different carbon sources including citrate, lactate and pyruvate. The predominant membrane fatty acids were C cis9 and C, followed by C cyclo and C cis11. The major polar lipids were phosphatidylglycerol and phosphatidylethanolamine, followed by diphosphatidyglycerol. The only quinone was ubiquinone Q-8. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NGK35 belongs to the genus (family ), appearing most closely related to CCUG 53761A (96.90 %) and ABC02-12 (96.94 %). The genomic DNA G+C content of strain NGK35 was 52.1 mol %. Genome-based calculations (genome-to-genome distance, average nucleotide identity and DNA G+C content) clearly indicated that the isolate represents a novel species within the genus . Based on phenotypic and molecular characterization, strain NGK35 can clearly be differentiated from its phylogenetic neighbours establishing a novel species, for which the name sp. nov. is proposed. The type strain is NGK35 (=DSM 113270=NCCB 100854).
Topics: Alcaligenaceae; Bacterial Typing Techniques; Base Composition; DNA, Bacterial; Fatty Acids; Phylogeny; Plastics; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Ubiquinone
PubMed: 35467502
DOI: 10.1099/ijsem.0.005333 -
Bioprocess and Biosystems Engineering Jun 2023Fluorescence spectroscopy is a non-invasive and highly sensitive method for bioprocess monitoring. The use of fluorescence spectroscopy is not very well established in...
Fluorescence spectroscopy is a non-invasive and highly sensitive method for bioprocess monitoring. The use of fluorescence spectroscopy is not very well established in the industry for in-line monitoring. In the present work, a 2-D fluorometer with two excitation lights (365 and 405 nm) and emission spectra in the range of 350-850 nm were used for in-line monitoring of two strains of Bordetella pertussis cultivation operated in batch and fed batch. A Partial Least Squares (PLS) based regression model was used for the estimation of cell biomass, amino acids (glutamate and proline) and antigen (Pertactin) produced. It was observed that accurate predictions were achieved when models were calibrated separately for each cell strain and nutrient media formulation. Also, prediction accuracy was improved when dissolved oxygen, agitation and culture volume are added as additional features in the regression model. The proposed approach of combining in-line fluorescence and other online measurements is shown to have good potential for in-line monitoring of bioprocesses.
Topics: Bordetella pertussis; Spectrometry, Fluorescence; Least-Squares Analysis; Amino Acids; Biomass
PubMed: 36971837
DOI: 10.1007/s00449-023-02857-6 -
The Journal of Infection Dec 2022
Topics: Humans; Bordetella; Bordetella Infections; Sepsis; Catheters; Catheter-Related Infections; Bacteremia
PubMed: 36220501
DOI: 10.1016/j.jinf.2022.10.008 -
International Journal of Systematic and... May 2020Two Gram-stain-negative, short rod-shaped and non-flagellated strains, designated 17-4A and L52-1-41, were isolated from the surface seawater of the Indian Ocean and...
Two Gram-stain-negative, short rod-shaped and non-flagellated strains, designated 17-4A and L52-1-41, were isolated from the surface seawater of the Indian Ocean and South China Sea, respectively. The 16S rRNA genes of the two strains shared sequence similarity of 99.45 %. Strain 17-4A shared the highest 16S rRNA gene similarity of 98.02 % with EBR-8-1, followed by BN9 (97.47 %), MJ07 (96.93 %), Ch07 (96.68 %), DCY25 (96.65 %), PB3-7B (96.63 %), 24 (96.34 %), 54Pin (96.28 %) and B201 (96.05 %). L52-1-41 shared the highest 16S rRNA gene similarity of 97.74 % with EBR-8-1, followed by BN9 (97.47 %), MJ07 (96.65 %), Ch07 (96.41 %), DCY25 (96.37 %), PB3-7B (96.35 %), B201 (96.28 %), and 24 (96.06 %). The results of phylogenetic analyses indicated that 17-4A and L52-1-41 formed a stable, distinct and highly supported lineage affiliated to the genus . The results of the digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses indicated that they represented a single species. They featured similar genomic DNA G+C contents of 53.2-53.4 mol%. Activities of catalase and oxidase were negative for both strains. The fatty acids patterns of 17-4A and L52-1-41 were most similar, mostly comprised of C, Ccyclo, C, Cω9 and summed feature 8 (Cω7 and/or C ω6). The major polar lipids of the two strains were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and unidentified aminolipids. The respiratory quinone of the two strains was Q-8. Hence, on the basis of the phenotypic, chemotaxonomic and genotypic data presented in this study, we proposed the classification of both strains as representatives of a novel species named sp. nov., with the type strain 17-4A (=MCCC 1A12670=KCTC 62121=NBRC 113794), and another strain L52-1-41 (=MCCC 1A05046=KCTC 52313).
Topics: Alcaligenaceae; Bacterial Typing Techniques; Base Composition; China; DNA, Bacterial; Fatty Acids; Indian Ocean; Nucleic Acid Hybridization; Phospholipids; Phylogeny; RNA, Ribosomal, 16S; Seawater; Sequence Analysis, DNA; Ubiquinone
PubMed: 32369004
DOI: 10.1099/ijsem.0.004202 -
Infection, Genetics and Evolution :... Jun 2016Whooping cough, or pertussis, is resurgent in many countries world-wide. This is linked to switching from the use of whole cell vaccines to acellular vaccines in... (Review)
Review
Whooping cough, or pertussis, is resurgent in many countries world-wide. This is linked to switching from the use of whole cell vaccines to acellular vaccines in developed countries. Current evidence suggests that this has resulted in the earlier waning of vaccine-induced immunity, an increase in asymptomatic infection with concomitant increases in transmission and increased selection pressure for Bordetellapertussis variants that are better able to evade vaccine-mediated immunity than older isolates. This review discusses recent findings in B. pertussis epidemiology and evolution in the light of pertussis resurgence, and highlights the important role for genomics-based studies in monitoring B. pertussis adaptation.
Topics: Adaptation, Physiological; Bordetella pertussis; Humans; Pertussis Vaccine; Selection, Genetic; Whooping Cough
PubMed: 26932577
DOI: 10.1016/j.meegid.2016.02.032 -
International Immunopharmacology Sep 2023The outer membrane vesicle (OMV) of bacteria is a bilayer membrane vesicle with a diameter of about 10-300 nm that is secreted during the growth of Gram-negative...
The outer membrane vesicle (OMV) of bacteria is a bilayer membrane vesicle with a diameter of about 10-300 nm that is secreted during the growth of Gram-negative bacteria. OMV is considered as a high-quality vaccine candidate antigen because of its natural immunogenicity and non-replicability. Although the excellent antigenicity of OMV has been widely confirmed, its instability and heterogeneity greatly affect its immune effect. Many studies have demonstrated that in combination with nanoparticles can enhance the stability of OMV. In this study, OMVs were used to coat chitosan nanoparticles (CNPs) and obtain a stable OMV vaccine. The characteristics, including morphology, hydrodynamic size, and zeta potential were evaluated. The immune protection of CNP-OMV and anti-infection efficacy were examined and compared in vivo and in vitro. The results showed that the CNP-OMV were homogenous with a size of 139 nm and a stable core-shell structure. And CNP-OMV could significantly increase the cell proliferation, phagocytosis and TNF-α, IL-6 and IL-10 secretion of RAW264.7 in vitro. In vivo, CNP-OMV could significantly increase the levels of anti-Bb and OMV IgG antibodies. Levels of blood lymphocyte, and Th1 (IFN-γ, IL-12), Th2 (IL-4, IL-5), and Th17 (IL-17, TNF-α) type cytokines in the serum were all significantly increased. At the same time, CNP-OMV could significantly reduce the bacterial invading the lungs of challenged rabbits. And CNP-OMV could largely protect the lungs from injury. The above results showed that CNP-OMV had a good immune efficacy and could resist the infection of Bordetella bronchiseptica. This study provided a scientific basis for the development of novel effective and safe vaccine against Bordetella bronchiseptica, and also provided a new idea for the development of new bacterial vaccine.
Topics: Animals; Rabbits; Bordetella bronchiseptica; Chitosan; Tumor Necrosis Factor-alpha; Bacterial Vaccines; Nanoparticles
PubMed: 37451023
DOI: 10.1016/j.intimp.2023.110612 -
The Science of the Total Environment Aug 2022Comprehensive knowledge on the biotransformation of tetracycline (TC) is critical for the improvement of TC removal in the bioremediation process. This work isolated a...
Comprehensive knowledge on the biotransformation of tetracycline (TC) is critical for the improvement of TC removal in the bioremediation process. This work isolated a novel TC-degrading bacterial strain Alcaligenes sp. T17 and explored its degradation ability under different conditions. Temperature and pH could affect the degradation efficiency, and higher temperature as well as neutral and weakly acidic conditions were conducive to the biotransformation. Response surface methodology predicted the maximum degradation rate of TC (94.35%) under the condition of 25.15 mg/L TC, pH 7.23, and inoculation dosage 1.17% at 40 °C. According to the result of disk diffusion tests, the biodegradation products had lower antimicrobial potency than the parent compound. Five potential biodegradation products were identified, and a possible degradation pathway (degrouping, oxidation and ring-opening) was proposed. The draft genome of strain T17 was also determined. Genomic analysis indicated that strain T17 harbored multiple genes that participated in the metabolism of aromatic compounds as well as genes encoding oxygenases. These functional genes may be relevant to TC biotransformation. This study could provide new insights towards the biotransformation of TC mediated by bacteria.
Topics: Alcaligenes; Anti-Bacterial Agents; Biodegradation, Environmental; Biotransformation; Tetracycline
PubMed: 35405229
DOI: 10.1016/j.scitotenv.2022.155130