DOCSLIB.ORG

Mechanisms of Interaction Between Haemophilus Parainfluenzae and Streptococcus Mitis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Mechanisms of Interaction Between Haemophilus Parainfluenzae and Streptococcus Mitis University of Rhode Island DigitalCommons@URI Open Access Dissertations 2021 MECHANISMS OF INTERACTION BETWEEN HAEMOPHILUS PARAINFLUENZAE AND STREPTOCOCCUS MITIS Dasith Perera Follow this and additional works at: https://digitalcommons.uri.edu/oa_diss MECHANISMS OF INTERACTION BETWEEN HAEMOPHILUS PARAINFLUENZAE AND STREPTOCOCCUS MITIS BY DASITH PERERA A DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN CELL & MOLECULAR BIOLOGY UNIVERSITY OF RHODE ISLAND 2021 DOCTOR OF PHILOSOPHY DISSERTATION OF DASITH PERERA APPROVED: Thesis Committee: Matthew Ramsey, Major professor David Nelson David Rowley Brenton DeBoef DEAN OF THE GRADUATE SCHOOL UNIVERSITY OF RHODE ISLAND 2021 ABSTRACT The human oral cavity is a complex polymicrobial environment, home to an array of microbes that play roles in health and disease. Oral bacteria have been shown to cause an array of systemic diseases and are particularly concerning to type II diabetics (T2D) with numerous predispositions that exacerbate bacterial infection. In this dissertation, we investigated the serum of healthy subjects and T2D subjects to determine whether we see greater translocation of oral bacteria into the bloodstream of T2D indiviDuals. We didn’t observe any significant enrichment of oral taxa, however we detected the presence of an emerging pathogen, Acinetobacter baumannii that is also associated with impaired inflammation in T2D. While some are associated with disease, many oral taxa are important in the pre- vention of disease. In this dissertation we investigated the interactions between two abundant health-associated commensal microbes, Haemophilus parainfluenzae and Streptococcus mitis. We demonstrated that H. parainfluenzae typically exists adjacent to Mitis group streptococci in vivo in healthy subjects. We revealed that this co-occur- rence is density dependent and further influenced by H2O2 production. Additionally, Mitis group streptococci are likely the in vivo source of NAD for H. parainfluenzae further facilitating this co-occurrence. We also investigated H. parainfluenzae’s re- sponse to H2O2, which is composed of a redundant OxyR-controlled system. Further- more, we showed that H2O2 likely elicits the SOS response in H. parainfluenzae which may be a mechanism of generating genetic diversity within this species. These findings reveal mechanisms behind why these two highly abundant taxa coexist in healthy indi- viduals. ACKNOWLEDGMENTS I would like to thank Matthew Ramsey for the years of mentoring, advice, stimu- lating discussions, help and support. I would also like to thank my parents, brother and sister for the many decades of support and more things that could be written. I thank my wife, Phone who I know has made many sacrifices over the past few years and without whom I probably would not have finished this. I thank my in-laws for their help over the last few years and being there for Phone and me. I thank lab members Eric, Thais and Alex for being great lab members and the very interesting Friday talks. I thank Zach for the coffee runs to Dunkin and stimulating science discussions. I would also like to thank other grads students at URI that have helped maintain a great work environment, especially Eric, Thais, Alex, Zach, Kathleen, Tomali, Chris and Katie. iii PREFACE This dissertation has been written in manuscript format iv TABLE OF CONTENTS ABSTRACT .................................................................................................................. ii ACKNOWLEDGMENTS ............................................................................................ iii PREFACE ...................................................................................................................... iv TABLE OF CONTENTS ............................................................................................... v LIST OF TABLES ...................................................................................................... viii LIST OF FIGURES ........................................................................................................ x CHAPTER 1: Introduction ............................................................................................. 1 CHAPTER 2: Impaired host response and the presence of Acinetobacter baumannii in the serum microbiome of type-II diabetic patients. .................................................. 8 Summary .............................................................................................................................. 10 Introduction ......................................................................................................................... 10 Results .................................................................................................................................. 15 Patient demographics ...................................................................................................... 15 Microbiome analysis controls for low template sequencing ............................................ 20 V1-V3 16S microbiome diversity analyses reveal minor but significant differences between diabetic and nondiabetic groups ........................................................................ 21 MED and DADA2 analysis reveal the presence of Acinetobacter baumanii ................... 25 Validating the presence of A. baumanii in T2D subjects ................................................. 29 Host cytokine responses to T2D and T2DP vs Health ...................................................... 30 Host cytokine responses to specific microbiota ................................................................ 33 Discussion ............................................................................................................................ 36 References ........................................................................................................................... 42 Appendix .............................................................................................................................. 54 CHAPTER 3: Mechanisms underlying proximity between oral commensal bacteria . 82 Abstract ................................................................................................................................ 84 Introduction ......................................................................................................................... 85 v Results .................................................................................................................................. 87 H. parainfluenzae co-occurs with S. mitis and related streptococci in human supragingival plaque ........................................................................................................ 87 Species-specific FISH demonstrates frequent H. parainfluenzae - S. mitis co-proximity 88 S. mitis eliminates H. parainfluenzae via production of H2O2 ......................................... 89 Individual H2O2 sensitive genes do not affect the fitness of H. parainfluenzae in coculture with S. mitis ...................................................................................................................... 91 S. mitis and other Streptococcus sp. support H. parainfluenzae growth .......................... 93 In vivo transcriptional responses of H. parainfluenzae vs in vitro ................................... 96 Discussion ............................................................................................................................ 97 Materials and Methods ...................................................................................................... 101 Strains and Media .......................................................................................................... 102 Genomic and plasmid DNA isolation ............................................................................. 102 Genetic manipulation of H. parainfluenzae ................................................................... 102 Read abundance data ..................................................................................................... 103 Plaque Collection, Fixation, and Storage ...................................................................... 103 DNA FISH and Mounting ............................................................................................... 104 Imaging .......................................................................................................................... 104 Image Analysis ............................................................................................................... 105 Mono and Coculture Assays ........................................................................................... 105 Disk diffusion assays ...................................................................................................... 106 Coculture transcriptome sample preparation ................................................................ 106 Transcriptome analyses ................................................................................................. 107 Complementing Nicotinamide Adenine Dinucleotide (NAD) auxotrophy of H. parainfluenzae ................................................................................................................ 107 FiGures ................................................................................................................................ 108 References ........................................................................................................................
Load more

Recommended publications
  • Articles Catalytic Cycling in Β-Phosphoglucomutase: a Kinetic
    9404 Biochemistry 2005, 44, 9404-9416 Articles Catalytic Cycling in â-Phosphoglucomutase: A Kinetic and Structural Analysis†,‡ Guofeng Zhang, Jianying Dai, Liangbing Wang, and Debra Dunaway-Mariano* Department of Chemistry, UniVersity of New Mexico, Albuquerque, New Mexico 87131-0001 Lee W. Tremblay and Karen N. Allen* Department of Physiology and Biophysics, Boston UniVersity School of Medicine, Boston, Massachusetts 02118-2394 ReceiVed March 26, 2005; ReVised Manuscript ReceiVed May 18, 2005 ABSTRACT: Lactococcus lactis â-phosphoglucomutase (â-PGM) catalyzes the interconversion of â-D-glucose 1-phosphate (â-G1P) and â-D-glucose 6-phosphate (G6P), forming â-D-glucose 1,6-(bis)phosphate (â- G16P) as an intermediate. â-PGM conserves the core domain catalytic scaffold of the phosphatase branch of the HAD (haloalkanoic acid dehalogenase) enzyme superfamily, yet it has evolved to function as a mutase rather than as a phosphatase. This work was carried out to identify the structural basis underlying this diversification of function. In this paper, we examine â-PGM activation by the Mg2+ cofactor, â-PGM activation by Asp8 phosphorylation, and the role of cap domain closure in substrate discrimination. First, the 1.90 Å resolution X-ray crystal structure of the Mg2+-â-PGM complex is examined in the context of + + previously reported structures of the Mg2 -R-D-galactose-1-phosphate-â-PGM, Mg2 -phospho-â-PGM, and Mg2+-â-glucose-6-phosphate-1-phosphorane-â-PGM complexes to identify conformational changes that occur during catalytic turnover. The essential role of Asp8 in nucleophilic catalysis was confirmed by demonstrating that the D8A and D8E mutants are devoid of catalytic activity.
    [Show full text]
  • Enhanced Phosphorylation of High-Mobility-Group Proteins In
    Proc. Nati. Acad. Sci. USA Vol. 78, No. 4, pp. 2189-2193, April 1981 Biochemistry Enhanced phosphorylation of high-mobility-group proteins in nuclease-sensitive mononucleosomes from butyrate-treated HeLa cells (hyperphosphorylation/transcriptionally active chromatin/sodium butyrate) BEATRIZ LEVY-WILSON Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92717 Communicated by James F. Bonner, December 29, 1980 ABSTRACT The protein composition of nucleosome fractions MATERIALS AND METHODS differing in their sensitivity to micrococcal nuclease and derived from butyrate-treated or untreated HeLa cells has been com- Cell Cultures. HeLa cells, line S3, were grown in monolay- pared. Most of the high-mobility-group-14 (HMG-14) and HMG- ers, either in T-150 culture flasks or in roller bottles, at 370C 17 content of HeLa cell chromatin is associated with those nu- in minimal essential medium (Flow Laboratories, Rockville, cleosomes that are preferentially sensitive to micrococcal nu- MD) supplemented with 7% bovine calfserum (KC Biologicals) clease. Furthermore, electrophoresis of these two HMG proteins and penicillin (100 units/ml) and streptomycin (100 Ag/ml) from the transcriptionally active chromatin fraction MN, of bu- (Sigma). In experiments involving sodium butyrate, this com- tyrate-treated cells resolves them into a series ofbands. The mul- pound was added to the cultures at a final concentration of5 mM tiple band pattern of HMG-14 and -17 from butyrate-treated cells about 20 hr prior to harvesting of the cells. results from hyperphosphorylation rather than hyperacetylation. Preparation of Nuclei. HeLa cell nuclei were prepared as Phosphorylation of these two small nonhistone proteins may play described by Milcarek et al.
    [Show full text]
  • Annotation of Glycolysis and Gluconeogenesis Pathways
    A metabolic insight into the Asian citrus psyllid: Annotation of glycolysis and gluconeogenesis pathways Blessy Tamayo, Kyle Kercher, Tom D’Elia, Helen Wiersma-Koch, Surya Saha, Teresa Shippy, Susan J. Brown, and Prashant Hosmani Introduction Glycolysis, as in other animals, is the major metabolic pathway that insects use to extract energy from carbohydrates [1]. This process consists of ten reactions that convert one molecule of glucose into two molecules of pyruvate within the cytosol, generating a net gain of two molecules of ATP. Simple carbohydrates are acquired through the insect diet and processed through glycolysis and the central carbohydrate metabolic steps. Comparative genomic analysis of Apis mellifera, Drosophila melanogaster, and Anopheles gambiae has revealed the presence of genes for metabolic pathways that support dietary habits dependent on sugar-rich substrates ([2]; [3]; [4]; [5]). In addition to processing sugars for energy, glycolysis also serves as a central pathway that serves as both a source of important precursors and destination for key intermediates from many metabolic pathways. Gluconeogenesis is the process through which glucose is synthesized from non- carbohydrate substrates, and is closely associated with glycolysis. Eleven enzymatic reactions occur during gluconeogenesis. Eight of the enzymes involved in the steps also catalyze the reverse reactions in glycolysis and the three remaining enzymes are specific to gluconeogenesis. 1 Gluconeogenesis generated carbohydrates are required as substrate for anaerobic glycolysis, synthesis of chitin, glycoproteins, polyols and glycoside detoxication products [1]. Gluconeogenesis is essential in insects to maintain sugar homeostasis and serves as the initial process towards the generation of glucose disaccharide trehalose, which is the main circulating sugar in the insect hemolymph ([6]; [7]).
    [Show full text]
  • Common Commensals
    Common Commensals Actinobacterium meyeri Aerococcus urinaeequi Arthrobacter nicotinovorans Actinomyces Aerococcus urinaehominis Arthrobacter nitroguajacolicus Actinomyces bernardiae Aerococcus viridans Arthrobacter oryzae Actinomyces bovis Alpha‐hemolytic Streptococcus, not S pneumoniae Arthrobacter oxydans Actinomyces cardiffensis Arachnia propionica Arthrobacter pascens Actinomyces dentalis Arcanobacterium Arthrobacter polychromogenes Actinomyces dentocariosus Arcanobacterium bernardiae Arthrobacter protophormiae Actinomyces DO8 Arcanobacterium haemolyticum Arthrobacter psychrolactophilus Actinomyces europaeus Arcanobacterium pluranimalium Arthrobacter psychrophenolicus Actinomyces funkei Arcanobacterium pyogenes Arthrobacter ramosus Actinomyces georgiae Arthrobacter Arthrobacter rhombi Actinomyces gerencseriae Arthrobacter agilis Arthrobacter roseus Actinomyces gerenseriae Arthrobacter albus Arthrobacter russicus Actinomyces graevenitzii Arthrobacter arilaitensis Arthrobacter scleromae Actinomyces hongkongensis Arthrobacter astrocyaneus Arthrobacter sulfonivorans Actinomyces israelii Arthrobacter atrocyaneus Arthrobacter sulfureus Actinomyces israelii serotype II Arthrobacter aurescens Arthrobacter uratoxydans Actinomyces meyeri Arthrobacter bergerei Arthrobacter ureafaciens Actinomyces naeslundii Arthrobacter chlorophenolicus Arthrobacter variabilis Actinomyces nasicola Arthrobacter citreus Arthrobacter viscosus Actinomyces neuii Arthrobacter creatinolyticus Arthrobacter woluwensis Actinomyces odontolyticus Arthrobacter crystallopoietes
    [Show full text]
  • Expression of a Phosphoglucomutase Gene in Rainbow Trout (Polymorphism/Developmental Rate/Glycolysis/Salmo Gairdneri) FRED W
    Proc. Natt Acad. Sci. USA Vol. 80, pp. 1397-1400, March 1983 Genetics Adaptive significance of differences in the tissue-specific expression of a phosphoglucomutase gene in rainbow trout (polymorphism/developmental rate/glycolysis/Salmo gairdneri) FRED W. ALLENDORF, KATHY L. KNUDSEN, AND ROBB F. LEARY Department of Zoology,, University of Montana, Missoula, Montana 59812 Communicated by G. Ledyard Stebbins, November 17, 1982 ABSTRACT We have investigated the phenotypic effects of fold increase in the expression of a phosphoglucomutase (PGM; a mutant allele that results in the expression of a phosphogluco- a-D-glucose-1,6-bisphosphate:a-D-glucose-l-phosphate phos- mutase locus (Pgml) in the liver of rainbow trout. Embryos with photransferase EC 2.7.5. 1) locus, Pgml, in liver tissue (14, 15). liver Pgml expression hatch earlier than embryos without liver The results of inheritance experiments are consistent with a sin- Pgml expression. These differences apparently result from in- gle regulatory gene, Pgml-t, with additive inheritance being re- creased flux through glycolysis in embryos with liver PGM1 ac- sponsible for the differences in the expression of this locus (15). tivity while they are dependent on the yolk for energy. Fish with We report here that the presence or absence of PGM1 in the liver PGM1 activity are also more developmentally buffered, as liver rise to indicated by less fluctuating asymmetry of five bilateral meristic gives important differences in several phenotypic traits. The more rapidly developing individuals begin exogenous characteristics of adaptive significance (developmental rate, de- feeding earlier and achieve a size advantage that is maintained velopmental stability, body size, and age at first maturity).
    [Show full text]
  • The Microbiota-Produced N-Formyl Peptide Fmlf Promotes Obesity-Induced Glucose
    Page 1 of 230 Diabetes Title: The microbiota-produced N-formyl peptide fMLF promotes obesity-induced glucose intolerance Joshua Wollam1, Matthew Riopel1, Yong-Jiang Xu1,2, Andrew M. F. Johnson1, Jachelle M. Ofrecio1, Wei Ying1, Dalila El Ouarrat1, Luisa S. Chan3, Andrew W. Han3, Nadir A. Mahmood3, Caitlin N. Ryan3, Yun Sok Lee1, Jeramie D. Watrous1,2, Mahendra D. Chordia4, Dongfeng Pan4, Mohit Jain1,2, Jerrold M. Olefsky1 * Affiliations: 1 Division of Endocrinology & Metabolism, Department of Medicine, University of California, San Diego, La Jolla, California, USA. 2 Department of Pharmacology, University of California, San Diego, La Jolla, California, USA. 3 Second Genome, Inc., South San Francisco, California, USA. 4 Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA. * Correspondence to: 858-534-2230, [email protected] Word Count: 4749 Figures: 6 Supplemental Figures: 11 Supplemental Tables: 5 1 Diabetes Publish Ahead of Print, published online April 22, 2019 Diabetes Page 2 of 230 ABSTRACT The composition of the gastrointestinal (GI) microbiota and associated metabolites changes dramatically with diet and the development of obesity. Although many correlations have been described, specific mechanistic links between these changes and glucose homeostasis remain to be defined. Here we show that blood and intestinal levels of the microbiota-produced N-formyl peptide, formyl-methionyl-leucyl-phenylalanine (fMLF), are elevated in high fat diet (HFD)- induced obese mice. Genetic or pharmacological inhibition of the N-formyl peptide receptor Fpr1 leads to increased insulin levels and improved glucose tolerance, dependent upon glucagon- like peptide-1 (GLP-1). Obese Fpr1-knockout (Fpr1-KO) mice also display an altered microbiome, exemplifying the dynamic relationship between host metabolism and microbiota.
    [Show full text]
  • Phosphoglycerate Mutase Deficiency
    Phosphoglycerate mutase deficiency Description Phosphoglycerate mutase deficiency is a disorder that primarily affects muscles used for movement (skeletal muscles). Beginning in childhood or adolescence, affected individuals experience muscle aches or cramping following strenuous physical activity. Some people with this condition also have recurrent episodes of myoglobinuria. Myoglobinuria occurs when muscle tissue breaks down abnormally and releases a protein called myoglobin, which is processed by the kidneys and released in the urine. If untreated, myoglobinuria can lead to kidney failure. In some cases of phosphoglycerate mutase deficiency, microscopic tube-shaped structures called tubular aggregates are seen in muscle fibers. It is unclear how tubular aggregates are associated with the signs and symptoms of the disorder. Frequency Phosphoglycerate mutase deficiency is a rare condition; about 15 affected people have been reported in the medical literature. Most affected individuals have been African American. Causes Phosphoglycerate mutase deficiency is caused by mutations in the PGAM2 gene. This gene provides instructions for making an enzyme called phosphoglycerate mutase, which is involved in a critical energy-producing process in cells known as glycolysis. During glycolysis, the simple sugar glucose is broken down to produce energy. The version of phosphoglycerate mutase produced from the PGAM2 gene is found primarily in skeletal muscle cells. Mutations in the PGAM2 gene greatly reduce the activity of phosphoglycerate mutase, which disrupts energy production in these cells. This defect underlies the muscle cramping and myoglobinuria that occur after strenuous exercise in affected individuals. Learn more about the gene associated with Phosphoglycerate mutase deficiency • PGAM2 Reprinted from MedlinePlus Genetics (https://medlineplus.gov/genetics/) 1 I nheritance This condition is inherited in an autosomal recessive pattern, which means both copies of the PGAM2 gene in each cell have mutations.
    [Show full text]
  • Termin Translat Trna Utr Mutat Protein Signal
    Drugs & Chemicals 1: Tumor Suppressor Protein p53 2: Heterogeneous-Nuclear Ribonucleo- (1029) proteins (14) activ apoptosi arf cell express function inactiv induc altern assai associ bind mdm2 mutat p53 p73 pathwai protein regul complex detect exon famili genom respons suppress suppressor tumor wild-typ interact intron isoform nuclear protein sensit site specif splice suggest variant 3: RNA, Transfer (110) 4: DNA Primers (1987) codon contain differ eukaryot gene initi amplifi analysi chain clone detect dna express mrna protein region ribosom rna fragment gene genotyp mutat pcr sequenc site speci suggest synthesi polymorph popul primer reaction region restrict sequenc speci termin translat trna utr 5: Saccharomyces cerevisiae Proteins 6: Apoptosis Regulatory Proteins (291) (733) activ apoptosi apoptosis-induc albican bud candida cerevisia complex encod apoptot bcl-2 caspas caspase-8 cell eukaryot fission function growth interact involv death fasl induc induct ligand methyl necrosi pathwai program sensit surviv trail mutant pomb protein requir saccharomyc strain suggest yeast 7: Plant Proteins (414) 8: Membrane Proteins (1608) access arabidopsi cultivar flower hybrid leaf leav apoptosi cell conserv domain express function gene human identifi inhibitor line maiz plant pollen rice root seed mammalian membran mice mous mutant seedl speci thaliana tomato transgen wheat mutat protein signal suggest transport 1 9: Tumor Suppressor Proteins (815) 10: 1-Phosphatidylinositol 3-Kinase activ arrest cell cycl cyclin damag delet dna (441) 3-kinas activ
    [Show full text]
  • TABLE S3 Clusters of Gene Ontology Groups and Their Associated Genes
    TABLE S3 Clusters of gene ontology groups and their associated genes found altered with Colchicine resistance (KB-8-5 vs KB-3-1) Annereau J-P, Szakacs G, Tucker CJ, Arciello A, Cardarelli C, Collins J, Grissom S, Zeeberg B, Reinhold W, Weinstein J, Pommier Y, Paules RS, and Gottesman MM (2004) Analysis of ABC transporter expression in drug-selected cell lines by a microarray dedicated to multidrug resistance. Mol Pharmacol doi:10.1124/mol.104.005009. a Gene Ontology subgroups and references HUGO HUGO gene description Antigen presentation GO:0030333 antigen_processing HLA-E + major histocompatibility complex, class i, e GO:0030106 MHC_class_I_receptor_activity HLA-C + major histocompatibility complex, class i, c GO:0019885 antigen_processing,_endogenous_antigen_via_MHC_class_I HLA-B + major histocompatibility complex, class i, b GO:0019883 antigen_presentation,_endogenous_antigen HLA-A + major histocompatibility complex, class i, a GO:0019882 antigen_presentation B2M + beta-2-microglobulin Metabolism of carbonhydrate ALDOA - fructose-bisphosphate aldolase a GO:0019320 tricarboxylic_acid_cycle ATP5J - atp synthase, h+ transporting, mitochondrial GO:0006007 monosaccharide_metabolism COX6C - cytochrome c oxidase, subunit vic GO:0046365 monosaccharide_catabolism DLD - dihydrolipoamide dehydrogenase, phe3 GO:0046164 main_pathways_of_carbohydrate_metabolism G6PD - glucose-6-phosphate dehydrogenase GO:0019320 hexose_metabolism GAPD - glyceraldehyde-3-phosphate dehydrogenase GO:0019318 hexose_catabolism HDLBP - high density lipoprotein binding
    [Show full text]
  • Bacterial Diversity and Functional Analysis of Severe Early Childhood
    www.nature.com/scientificreports OPEN Bacterial diversity and functional analysis of severe early childhood caries and recurrence in India Balakrishnan Kalpana1,3, Puniethaa Prabhu3, Ashaq Hussain Bhat3, Arunsaikiran Senthilkumar3, Raj Pranap Arun1, Sharath Asokan4, Sachin S. Gunthe2 & Rama S. Verma1,5* Dental caries is the most prevalent oral disease afecting nearly 70% of children in India and elsewhere. Micro-ecological niche based acidifcation due to dysbiosis in oral microbiome are crucial for caries onset and progression. Here we report the tooth bacteriome diversity compared in Indian children with caries free (CF), severe early childhood caries (SC) and recurrent caries (RC). High quality V3–V4 amplicon sequencing revealed that SC exhibited high bacterial diversity with unique combination and interrelationship. Gracillibacteria_GN02 and TM7 were unique in CF and SC respectively, while Bacteroidetes, Fusobacteria were signifcantly high in RC. Interestingly, we found Streptococcus oralis subsp. tigurinus clade 071 in all groups with signifcant abundance in SC and RC. Positive correlation between low and high abundant bacteria as well as with TCS, PTS and ABC transporters were seen from co-occurrence network analysis. This could lead to persistence of SC niche resulting in RC. Comparative in vitro assessment of bioflm formation showed that the standard culture of S. oralis and its phylogenetically similar clinical isolates showed profound bioflm formation and augmented the growth and enhanced bioflm formation in S. mutans in both dual and multispecies cultures. Interaction among more than 700 species of microbiota under diferent micro-ecological niches of the human oral cavity1,2 acts as a primary defense against various pathogens. Tis has been observed to play a signifcant role in child’s oral and general health.
    [Show full text]
  • Nucleosome Phasing and Micrococcal Nuclease Cleavage of African Green Monkey Component a DNA (Nucleosomes and Chromatdn/Primate Dnas/DNA Sequence) PHILLIP R
    Proc. Natl Acad. Sci. USA Vol. 79, pp. 118-122, January 1982 Cell Biology Nucleosome phasing and micrococcal nuclease cleavage of African green monkey component a DNA (nucleosomes and chromatdn/primate DNAs/DNA sequence) PHILLIP R. MUSICH*, FRED L. BROWN, AND JOSEPH J. MAIO Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 Communicated by Harry Eagle, September 14, 1981 ABSTRACT The micrococcal nuclease cleavage of intact nu- gestion was made that these results simply reflect a DNA se- clear chromatin from African green monkey cells and ofthe com- quence specificity of the micrococcal nuclease. Nucleosome pletely deproteinized sequences was studied by using high-reso- phasing would not have to be invoked. Although phase rela- lution analytical and DNA sequencing gels and secondary restric- tionships have been observed for other repetitive and 5S DNA tion enzyme analysis. When deproteinized component a DNAwas (5, 10), some tRNA coding regions (11), gene domains (12), and used as substrate, not all phosphodiester bonds in the 172-base- regions of the simian virus 40 genome (13, 14), these results pair repeat units were cleaved with equal frequency by the nu- would also now be in doubt if micrococcal nuclease shows site clease. A distinct preference for the cleavage of A-T rather than specificity with deproteinized DNA that could give rise to spu- G-C bonds was observed: however, A+T-richness in itselfdid not rious phase relationships in chromatin. confer susceptibility to cleavage by micrococcal nuclease. The re- We performed detailed sequence analysis ofthe micrococcal sults suggested that, in deproteinized DNA, nuclease cleavage at a particular dinucleotides may be influenced more by the effect of nuclease products of completely deproteinized component adjacent sequences than by the composition of the dinucleotide.
    [Show full text]
  • Frequent Detection of Streptococcus Tigurinus in the Human Oral
    Zbinden et al. BMC Microbiology 2014, 14:231 http://www.biomedcentral.com/1471-2180/14/231 RESEARCH ARTICLE Open Access Frequent detection of Streptococcus tigurinus in the human oral microbial flora by a specific 16S rRNA gene real-time TaqMan PCR Andrea Zbinden1,4*,FatmaAras2, Reinhard Zbinden1, Forouhar Mouttet1, Patrick R Schmidlin2, Guido V Bloemberg1† and Nagihan Bostanci3† Abstract Background: Many bacteria causing systemic invasive infections originate from the oral cavity by entering the bloodstream. Recently, a novel pathogenic bacterium, Streptococcus tigurinus, was identified as causative agent of infective endocarditis, spondylodiscitis and meningitis. In this study, we sought to determine the prevalence of S. tigurinus in the human oral microbial flora and analyzed its association with periodontal disease or health. Results: We developed a diagnostic highly sensitive and specific real-time TaqMan PCR assay for detection of S. tigurinus in clinical samples, based on the 16S rRNA gene. We analyzed saliva samples and subgingival plaque samples of a periodontally healthy control group (n = 26) and a periodontitis group (n = 25). Overall, S. tigurinus was detected in 27 (53%) out of 51 patients. There is no significant difference of the frequency of S. tigurinus detection by RT-PCR in the saliva and dental plaque samples in the two groups: in the control group, 14 (54%) out of 26 individuals had S. tigurinus either in the saliva samples and/or in the plaque samples; and in the periodontitis group, 13 (52%) out of 25 patients had S. tigurinus in the mouth samples, respectively (P = 0.895). The consumption of nicotine was no determining factor.
    [Show full text]