scholarly journals A New Pneumococcal Capsule Type, 10D, is the 100th Serotype and Has a Large cps Fragment from an Oral Streptococcus

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Feroze Ganaie ◽  
Jamil S. Saad ◽  
Lesley McGee ◽  
Andries J. van Tonder ◽  
Stephen D. Bentley ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Capsular Polysaccharides ◽  
Oral Streptococci ◽  
Genetic Studies ◽  
Content Type ◽  
Capsule Type ◽  
Oral Streptococcus ◽  
Interspecies Recombination ◽  
Large Repertoire ◽  
Unique Chemical

ABSTRACT Streptococcus pneumoniae (pneumococcus) is a major human pathogen producing structurally diverse capsular polysaccharides. Widespread use of highly successful pneumococcal conjugate vaccines (PCVs) targeting pneumococcal capsules has greatly reduced infections by the vaccine types but increased infections by nonvaccine serotypes. Herein, we report a new and the 100th capsule type, named serotype 10D, by determining its unique chemical structure and biosynthetic roles of all capsule synthesis locus (cps) genes. The name 10D reflects its serologic cross-reaction with serotype 10A and appearance of cross-opsonic antibodies in response to immunization with 10A polysaccharide in a 23-valent pneumococcal vaccine. Genetic analysis showed that 10D cps has three large regions syntenic to and highly homologous with cps loci from serotype 6C, serotype 39, and an oral streptococcus strain (S. mitis SK145). The 10D cps region syntenic to SK145 is about 6 kb and has a short gene fragment of wciNα at the 5′ end. The presence of this nonfunctional wciNα fragment provides compelling evidence for a recent interspecies genetic transfer from oral streptococcus to pneumococcus. Since oral streptococci have a large repertoire of cps loci, widespread PCV usage could facilitate the appearance of novel serotypes through interspecies recombination. IMPORTANCE The polysaccharide capsule is essential for the pathogenicity of pneumococcus, which is responsible for millions of deaths worldwide each year. Currently available pneumococcal vaccines are designed to elicit antibodies to the capsule polysaccharides of the pneumococcal isolates commonly causing diseases, and the antibodies provide protection only against the pneumococcus expressing the vaccine-targeted capsules. Since pneumococci can produce different capsule polysaccharides and therefore reduce vaccine effectiveness, it is important to track the appearance of novel pneumococcal capsule types and how these new capsules are created. Herein, we describe a new and the 100th pneumococcal capsule type with unique chemical and serological properties. The capsule type was named 10D for its serologic similarity to 10A. Genetic studies provide strong evidence that pneumococcus created 10D capsule polysaccharide by capturing a large genetic fragment from an oral streptococcus. Such interspecies genetic exchanges could greatly increase diversity of pneumococcal capsules and complicate serotype shifts.

scholarly journals Targeting the HUβ Protein PreventsPorphyromonas gingivalisfrom Entering into Preexisting Biofilms

2018 ◽  
Vol 200 (11) ◽  
pp. e00790-17 ◽  
Author(s):  
Christopher J. Rocco ◽  
Lauren O. Bakaletz ◽  
Steven D. Goodman
Keyword(s):  
Oral Cavity ◽  
Periodontal Disease ◽  
Porphyromonas Gingivalis ◽  
The United States ◽  
Extracellular Dna ◽  
Bacterial Biofilms ◽  
Oral Streptococci ◽  
Content Type ◽  
Oral Streptococcus ◽  
Streptococcal Species

ABSTRACTThe oral cavity is home to a wide variety of bacterial species, both commensal, such as various streptococcal species, and pathogenic, such asPorphyromonas gingivalis, one of the main etiological agents of periodontal disease. Our understanding of how these bacteria ultimately cause disease is highly dependent upon understanding how they coexist and interact with one another in biofilm communities and the mechanisms by which biofilms are formed. Our research has demonstrated that the DNABII family of DNA-binding proteins are important components of the extracellular DNA (eDNA)-dependent matrix of bacterial biofilms and that sequestering these proteins via protein-specific antibodies results in the collapse of the biofilm structure and release of the resident bacteria. While the high degree of similarity among the DNABII family of proteins has allowed antibodies derived against specific DNABII proteins to disrupt biofilms formed by a wide range of bacterial pathogens, the DNABII proteins ofP. gingivalishave proven to be antigenically distinct, allowing us to determine if we can use anti-P. gingivalisHUβ antibodies to specifically target this species for removal from a mixed-species biofilm. Importantly, despite forming homotypic biofilmsin vitro,P. gingivalismust enter preexisting biofilmsin vivoin order to persist within the oral cavity. The data presented here indicate that antibodies derived against theP. gingivalisDNABII protein, HUβ, reduce by half the amount ofP. gingivalisorganisms entering into preexisting biofilm formed by four oral streptococcal species. These results support our efforts to develop methods for preventing and treating periodontal disease.IMPORTANCEPeriodontitis is one of the most prevalent chronic infections, affecting 40 to 50% of the population of the United States. The root cause of periodontitis is the presence of bacterial biofilms within the gingival space, withPorphyromonas gingivalisbeing strongly associated with the development of the disease. Periodontitis also increases the risk of secondary conditions and infections such as atherosclerosis and infective endocarditis caused by oral streptococci. To induce periodontitis,P. gingivalisneeds to incorporate into preformed biofilms, with oral streptococci being important binding partners. Our research demonstrates that targeting DNABII proteins with an antibody disperses oral streptococcus biofilm and preventsP. gingivalisentry into oral streptococcus biofilm. These results suggest potential therapeutic treatments for endocarditis caused by streptococci as well as periodontitis.

scholarly journals PerR-Regulated Manganese Ion Uptake Contributes to Oxidative Stress Defense in an Oral Streptococcus

2014 ◽  
Vol 80 (8) ◽  
pp. 2351-2359 ◽  
Author(s):  
Xinhui Wang ◽  
Huichun Tong ◽  
Xiuzhu Dong
Keyword(s):  
Iron Homeostasis ◽  
Critical Role ◽  
Brain Heart Infusion ◽  
Oral Streptococci ◽  
Content Type ◽  
Manganese Ion ◽  
Gram Positive Bacteria ◽  
Wild Type Phenotype ◽  
Oral Streptococcus ◽  
Antioxidative Stress

ABSTRACTMetal homeostasis plays a critical role in antioxidative stress.Streptococcus oligofermentans, an oral commensal facultative anaerobe lacking catalase activity, produces and tolerates abundant H2O2, whereas Dpr (an Fe2+-chelating protein)-dependent H2O2protection does not confer such high tolerance. Here, we report that inactivation ofperR, a peroxide-responsive repressor that regulates zinc and iron homeostasis in Gram-positive bacteria, increased the survival of H2O2-pulsedS. oligofermentans32-fold and elevated cellular manganese 4.5-fold.perRcomplementation recovered the wild-type phenotype. When grown in 0.1 to 0.25 mM MnCl2,S. oligofermentansincreased survival after H2O2stress 2.5- to 23-fold, and even greater survival was found for theperRmutant, indicating that PerR is involved in Mn2+-mediated H2O2resistance inS. oligofermentans. Mutation ofmntAcould not be obtained in brain heart infusion (BHI) broth (containing ∼0.4 μM Mn2+) unless it was supplemented with ≥2.5 μM MnCl2and caused 82 to 95% reduction of the cellular Mn2+level, whilemntABCoverexpression increased cellular Mn2+2.1- to 4.5-fold. Thus, MntABC was identified as a high-affinity Mn2+transporter inS. oligofermentans. mntAmutation reduced the survival of H2O2-pulsedS. oligofermentans5.7-fold, whilemntABCoverexpression enhanced H2O2-challenged survival 12-fold, indicating that MntABC-mediated Mn2+uptake is pivotal to antioxidative stress inS. oligofermentans. perRmutation or H2O2pulsing upregulatedmntABC, while H2O2-induced upregulation diminished in theperRmutant. This suggests thatperRrepressesmntABCexpression but H2O2can release the suppression. In conclusion, this work demonstrates that PerR regulates manganese homeostasis inS. oligofermentans, which is critical to H2O2stress defenses and may be distributed across all oral streptococci lacking catalase.

scholarly journals Macrophage Polarization Alters Postphagocytosis Survivability of the CommensalStreptococcus gordonii

2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Andrew J. Croft ◽  
Sarah Metcalfe ◽  
Kiyonobu Honma ◽  
Jason G. Kay
Keyword(s):  
Macrophage Polarization ◽  
Oral Bacteria ◽  
Ros Production ◽  
Systemic Diseases ◽  
Oxygen Species ◽  
Oral Streptococci ◽  
Phagocytic Cells ◽  
Content Type ◽  
Systemic Inflammatory Disease ◽  
Oral Streptococcus

ABSTRACTOral streptococci are generally considered commensal organisms; however, they are becoming recognized as important associate pathogens during the development of periodontal disease as well as being associated with several systemic diseases, including as a causative agent of infective endocarditis. An important virulence determinant of these bacteria is an ability to evade destruction by phagocytic cells, yet how this subversion occurs is mostly unknown. UsingStreptococcus gordoniias a model commensal oral streptococcus that is also associated with disease, we find that resistance to reactive oxygen species (ROS) with an active ability to damage phagosomes allows the bacterium to avoid destruction within macrophages. This ability to survive relies not only on the ROS resistance capabilities of the bacterium but also on ROS production by macrophages, with both being required for maximal survival of internalized bacteria. Importantly, we also show that this dependence on ROS production by macrophages for resistance has functional significance:S. gordoniiintracellular survival increases when macrophages are polarized toward an activated (M1) profile, which is known to result in prolonged phagosomal ROS production compared to that of alternatively (M2) polarized macrophages. We additionally find evidence of the bacterium being capable of both delaying the maturation of and damaging phagosomes. Taken together, these results provide essential insights regarding the mechanisms through which normally commensal oral bacteria can contribute to both local and systemic inflammatory disease.

scholarly journals Establishment of a Tractable Genetic Transformation System in Veillonella spp.

2012 ◽  
Vol 78 (9) ◽  
pp. 3488-3491 ◽  
Author(s):  
Jinman Liu ◽  
Zhoujie Xie ◽  
Justin Merritt ◽  
Fengxia Qi
Keyword(s):  
Escherichia Coli ◽  
Genetic Transformation ◽  
Shuttle Vector ◽  
Transformation System ◽  
Genetic Studies ◽  
Content Type ◽  
Genetic Transformation System

ABSTRACTWe have constructed the firstEscherichia coli-Veillonellashuttle vector based on an endogenous plasmid (pVJL1) isolated from a clinicalVeillonellastrain. A highly transformableVeillonellastrain was also identified. Both the shuttle vector and the transformable strain should be valuable tools for futureVeillonellagenetic studies.

Zwitterions: Promising Interfacial / Doping Materials for Organic / Perovskite Solar Cells

2021 ◽  
Author(s):  
Qiaoyun Chen ◽  
Xudong Yang ◽  
Yi Zhou ◽  
Bo Song
Keyword(s):  
Solar Cells ◽  
Chemical Structure ◽  
Perovskite Solar Cells ◽  
Unique Chemical

Zwitterions, due to the unique chemical structure and electrical charges, has caught continuous attention in organic / perovskite solar cells (OSCs / PSCs). It is widely used as interfacial materials...

Enhancement of Thermo-Oxidative Stability of Vegetable Oil Based Lubricant via Chemical Modification Techniques

2015 ◽  
Vol 813-814 ◽  
pp. 695-699
Author(s):  
S. Arumugam ◽  
G. Sriram ◽  
A. Hemanth Sai Kumar Chowdary ◽  
Janga Subramanya Sai
Keyword(s):  
Chemical Modification ◽  
Oxidative Stability ◽  
Vegetable Oils ◽  
Rapeseed Oil ◽  
Chemical Structure ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Transesterification Method ◽  
Unique Chemical

The rising demand for environmentally acceptable lubricant has led researchers to look to vegetable oils as an alternative to petroleum based lubricants. Vegetable oils have radically distinctive properties owing to their unique chemical structure which have greater ability to lubricate and have higher biodegradability. In spite of advantages, they are limited to inadequate thermo-oxidative stability and poor low-temperature properties which hinder their utilization. In the present study in order to produce a bio lubricant with good thermo-oxidative stability, rapeseed oil was subjected to two different chemical modification techniques viz., epoxidation method and successive transesterification method. The thermo-oxidative stability of formulated oil was analysed using Thermo Gravimetric Analysis (TGA). TGA analysis divulges that the thermo-oxidative stability of rapeseed oil was greatly improved with the epoxidation method in comparison with the successive transesterification method.

scholarly journals Synergistic Interaction between Candida albicans and Commensal Oral Streptococci in a NovelIn VitroMucosal Model

2011 ◽  
Vol 80 (2) ◽  
pp. 620-632 ◽  
Author(s):  
Patricia I. Diaz ◽  
Zhihong Xie ◽  
Takanori Sobue ◽  
Angela Thompson ◽  
Basak Biyikoglu ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Gastrointestinal Tract ◽  
Oral Mucosa ◽  
Biofilm Formation ◽  
Salivary Flow ◽  
Flow Cell ◽  
Synergistic Interaction ◽  
Esophageal Mucosa ◽  
Oral Streptococci ◽  
Content Type

ABSTRACTCandida albicansis a commensal colonizer of the gastrointestinal tract of humans, where it coexists with highly diverse bacterial communities. It is not clear whether this interaction limits or promotes the potential ofC. albicansto become an opportunistic pathogen. Here we investigate the interaction betweenC. albicansand three species of streptococci from the viridans group, which are ubiquitous and abundant oral commensal bacteria. The ability ofC. albicansto form biofilms withStreptococcus oralis,Streptococcus sanguinis, orStreptococcus gordoniiwas investigated using flow cell devices that allow abiotic biofilm formation under salivary flow. In addition, we designed a novel flow cell system that allows mucosal biofilm formation under conditions that mimic the environment in the oral and esophageal mucosae. It was observed thatC. albicansand streptococci formed a synergistic partnership whereC. albicanspromoted the ability of streptococci to form biofilms on abiotic surfaces or on the surface of an oral mucosa analogue. The increased ability of streptococci to form biofilms in the presence ofC. albicanscould not be explained by a growth-stimulatory effect since the streptococci were unaffected in their growth in planktonic coculture withC. albicans. Conversely, the presence of streptococci increased the ability ofC. albicansto invade organotypic models of the oral and esophageal mucosae under conditions of salivary flow. Moreover, characterization of mucosal invasion by the biofilm microorganisms suggested that the esophageal mucosa is more permissive to invasion than the oral mucosa. In summary,C. albicansand commensal oral streptococci display a synergistic interaction with implications for the pathogenic potential ofC. albicansin the upper gastrointestinal tract.

Use of Opuntia ficus extract as a corrosion inhibitor for carbon steel in acidic media

2014 ◽  
Vol 61 (4) ◽  
pp. 224-231 ◽  
Author(s):  
Ruben Suarez-Hernandez ◽  
Jose G. Gonzalez-Rodriguez ◽  
Gloria F. Dominguez-Patiño ◽  
Alberto Martinez-Villafañe
Keyword(s):  
Carbon Steel ◽  
Chemical Structure ◽  
Electrochemical Impedance ◽  
Green Inhibitor ◽  
Opuntia Ficus Indica ◽  
Content Type ◽  
Acid Cleaning ◽  
Static Conditions ◽  
The Cost ◽  
Practical Implications

Purpose – The purpose of this investigation is to study the corrosion inhibition of carbon steel (CS) using a “green” inhibitor, Opuntia ficus-indica, in an aerated, 0.5 M H2SO4 solution at different concentrations and temperatures. Design/methodology/approach – Weight loss determinations, surface studies, electrochemical impedance spectroscopy and potentiodynamic polarization were applied during the investigation. Findings – It was observed that Opuntia ficus-indica extract can decrease the corrosion rate of CS, and its efficiency increases with increasing concentration up to 1,000 ppm and with time, but decreases with increasing the temperature from 25 to 600C. The inhibitory activity is due to the presence of phenolic compounds in its chemical structure. Research limitations/implications – The work was done under static conditions, whereas in acid cleaning conditions, there is a dynamic system. However, the findings may apply to both the systems. Practical implications – CS is used in acidic environments in the acid cleaning industry. Social implications – Results of this work show that it is possible to reduce the cost of repair of equipment and the environmental impact of corrosion. Originality/value – There are very few investigations on the study of Opuntia ficus-indica leaf extract as a green inhibitor in an acidic environment.

scholarly journals Comparative Study of Immunogenic Properties of Purified Capsular Polysaccharides from Streptococcus suis Serotypes 3, 7, 8, and 9: the Serotype 3 Polysaccharide Induces an Opsonizing IgG Response

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
Guillaume Goyette-Desjardins ◽  
Jean-Philippe Auger ◽  
Dominic Dolbec ◽  
Evgeny Vinogradov ◽  
Masatoshi Okura ◽  
...  
Keyword(s):  
Immune System ◽  
Secondary Infection ◽  
Streptococcus Suis ◽  
Biochemical Properties ◽  
Divergent Evolution ◽  
Effective Vaccine ◽  
Capsular Polysaccharides ◽  
Content Type ◽  
Chemokine Ligand ◽  
Encapsulated Bacteria

ABSTRACT Streptococcus suis is an encapsulated bacterium and one of the most important swine pathogens and a zoonotic agent for which no effective vaccine exists. Bacterial capsular polysaccharides (CPSs) are poorly immunogenic, but anti-CPS antibodies are essential to the host defense against encapsulated bacteria. In addition to the previously known serotypes 2 and 14, which are nonimmunogenic, we have recently purified and described the CPS structures for serotypes 1, 1/2, 3, 7, 8, and 9. Here, we aimed to elucidate how these new structurally diverse CPSs interact with the immune system to generate anti-CPS antibody responses. CPS-stimulated dendritic cells produced significant levels of C–C motif chemokine ligand 3 (CCL3), partially via Toll-like receptor 2 (TLR2)- and myeloid differentiation factor 88-dependent pathways, and CCL2, via TLR-independent mechanisms. Mice immunized with purified serotype 3 CPS adjuvanted with TiterMax Gold produced an opsonizing IgG response, whereas other CPSs or adjuvants were negative. Mice hyperimmunized with heat-killed S. suis serotypes 3 and 9 both produced anti-CPS type 1 IgGs, whereas serotypes 7 and 8 remained negative. Also, mice infected with sublethal doses of S. suis serotype 3 produced primary anti-CPS IgM and IgG responses, of which only IgM were boosted after a secondary infection. In contrast, mice sublethally infected with S. suis serotype 9 produced weak anti-CPS IgM and IgG responses following a secondary infection. This study provides important information on the divergent evolution of CPS serotypes with highly different structural and/or biochemical properties within S. suis and their interaction with the immune system.

scholarly journals Molecular Characterization ofblaNDM-1in a Sequence Type 235 Pseudomonas aeruginosa Isolate from France

2013 ◽  
Vol 57 (7) ◽  
pp. 3408-3411 ◽  
Author(s):  
Frédéric Janvier ◽  
Katy Jeannot ◽  
Sophie Tessé ◽  
Marjorie Robert-Nicoud ◽  
Hervé Delacour ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Insertion Sequence ◽  
Variable Region ◽  
Sequence Type ◽  
Common Region ◽  
Class 1 Integron ◽  
Genetic Studies ◽  
Content Type ◽  
Class 1 ◽  
Previous Hospitalization

ABSTRACTAn NDM-1 carbapenemase-producingPseudomonas aeruginosaisolate was recovered from a patient hospitalized in France after a previous hospitalization in Serbia. Genetic studies revealed that theblaNDM-1gene was surrounded by insertion sequence ISAba125and a truncated bleomycin resistance gene. ThisblaNDM-1region was a part of the variable region of a new complex class 1 integron bearing IS common region 1 (ISCR1). The presence of ISPa7upstream of this integron suggests insertion in a chromosomally located Tn402-like structure.

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