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Sample records for infecciones por streptococcus

  1. Prevalencia y factores de riesgo para infecciones del tracto urinario de inicio en la comunidad causadas por Escherichia coli productor de betalactamasas de espectro extendido en Colombia

    PubMed Central

    Blanco, Victor M.; Maya, Juan J.; Correa, Adriana; Perenguez, Marcela; Muñoz, Juan S.; Motoa, Gabriel; Pallares, Christian J.; Rosso, Fernando; Matta, Lorena; Celis, Yamile; Garzon, Martha; Villegas, y María V.

    2016-01-01

    RESUMEN Introducción Las infecciones del tracto urinario (ITU) son frecuentes en la comunidad. Sin embargo, la información de aislamientos resistentes en este contexto es limitada en Latinoamérica. Este estudio tiene como objetivo determinar la prevalencia y los factores de riesgo asociados con ITU de inicio en la comunidad (ITU-IC) causadas por Escherichia coli productor de betalactamasas de espectro extendido (BLEE) en Colombia. Materiales y métodos Entre agosto y diciembre de 2011 se realizó un estudio de casos y controles en 3 instituciones de salud de tercer nivel en Colombia. Se invitó a participar a todos los pacientes admitidos a urgencias con diagnóstico probable de ITU-IC, y se les pidió una muestra de orina. En los aislamien-tos de E. coli se realizaron pruebas confirmatorias para BLEE, susceptibilidad antibiótica, caracterización molecular (PCR en tiempo real para genes bla, repetitive element palindromic PCR [rep-PCR], multilocus sequence typing [MLST] y factores de virulencia por PCR). Se obtuvo información clínica y epidemiológica, y posteriormente se realizó el análisis estadístico. Resultados De los 2.124 pacientes seleccionados, 629 tuvieron un urocultivo positivo, en 431 de estos se aisló E. coli, 54 fueron positivos para BLEE y 29 correspondieron a CTX-M-15. La mayoría de los aislamientos de E. coli productor de BLEE fueron sensibles a ertapenem, fosfomicina y amikacina. La ITU complicada se asoció fuertemente con infecciones por E. coli productor de BLEE (OR = 3,89; IC 95%: 1,10–13,89; p = 0,03). E. coli productor de CTX-M-15 mostró 10 electroferotipos diferentes; de estos, el 65% correspondieron al ST131. La mayoría de estos aislamientos tuvieron 8 de los 9 factores de virulencia analizados. Discusión E. coli portador del gen blaCTX-M-15 asociado al ST131 sigue siendo frecuente en Colombia. La presencia de ITU-IC complicada aumenta el riesgo de tener E. coli productor de BLEE, lo cual debe tenerse en cuenta para ofrecer

  2. Streptococcus iniae and Streptococcus agalactiae

    USDA-ARS?s Scientific Manuscript database

    Streptococcus iniae and S. agalactiae are economically important Gram positive bacterial pathogens of cultured and wild fish with a worldwide distribution. Both bacteria are potential zoonotic pathogens and have been associated most often with infections in immunocompromised people. Streptococcus in...

  3. Streptococcus anginosus ("Streptococcus milleri"): the unrecognized pathogen.

    PubMed Central

    Ruoff, K L

    1988-01-01

    "Streptococcus milleri" is an unofficial name that has been applied to a group of streptococci which, although basically similar, show various hemolytic, serological, and physiological characteristics. The species name Streptococcus anginosus has recently been recognized as the approved name for these organisms. Streptococci known as "S. milleri" have been implicated as etiologic agents in a variety of serious purulent infections, but because of their heterogeneous characteristics, these organisms may be unrecognized or misidentified by clinical laboratorians. This review describes the bacteriological aspects of organisms known as "S. milleri," their clinical significance, and the problems encountered with their identification in the clinical laboratory. PMID:3060239

  4. Group B Streptococcus and Pregnancy

    MedlinePlus

    f AQ FREQUENTLY ASKED QUESTIONS FAQ105 PREGNANCY Group B Strep and Pregnancy • What is group B streptococcus (GBS)? • What does it mean to be ... a planned cesarean birth? •Glossary What is group B streptococcus (GBS)? Group B streptococcus is one of ...

  5. Prophage-Cured Derivatives of Streptococcus lactis and Streptococcus cremoris

    PubMed Central

    Gasson, Michael J.; Davies, F. Lyndon

    1980-01-01

    Prophage curing was achieved in Streptococcus lactis and Streptococcus cremoris, and the cured derivatives were shown to be indicators for their temperate bacteriophages. Relysogenization of these cured derivatives completed the first formal demonstration of the lysogenic state in lactic streptococci. Images PMID:16345661

  6. Streptococcus pneumoniae, le transformiste.

    PubMed

    Johnston, Calum; Campo, Nathalie; Bergé, Matthieu J; Polard, Patrice; Claverys, Jean-Pierre

    2014-03-01

    Streptococcus pneumoniae (the pneumococcus) is an important human pathogen. Natural genetic transformation, which was discovered in this species, involves internalization of exogenous single-stranded DNA and its incorporation into the chromosome. It allows acquisition of pathogenicity islands and antibiotic resistance and promotes vaccine escape via capsule switching. This opinion article discusses how recent advances regarding several facets of pneumococcal transformation support the view that the process has evolved to maximize plasticity potential in this species, making the pneumococcus le transformiste of the bacterial kingdom and providing an advantage in the constant struggle between this pathogen and its host.

  7. Multiplex PCR-based identification of Streptococcus canis, Streptococcus zooepidemicus and Streptococcus dysgalactiae subspecies from dogs.

    PubMed

    Moriconi, M; Acke, E; Petrelli, D; Preziuso, S

    2017-02-01

    Streptococcus canis (S. canis), Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) and Streptococcus dysgalactiae subspecies (S. dysgalactiae subspecies) are β-haemolytic Gram positive bacteria infecting animals and humans. S. canis and S. zooepidemicus are considered as two of the major zoonotic species of Streptococcus, while more research is needed on S. dysgalactiae subspecies bacteria. In this work, a multiplex-PCR protocol was tested on strains and clinical samples to detect S. canis, S. dysgalactiae subspecies and S. equi subspecies bacteria in dogs. All strains were correctly identified as S. canis, S. equi subspecies or S. dysgalactiae subspecies by the multiplex-PCR. The main Streptococcus species isolated from symptomatic dogs were confirmed S. canis. The multiplex-PCR protocol described is a rapid, accurate and efficient method for identifying S. canis, S. equi subspecies and S. dysgalactiae subspecies in dogs and could be used for diagnostic purposes and for epidemiological studies.

  8. Genetic Manipulation of Streptococcus pyogenes (The Group A Streptococcus, GAS)

    PubMed Central

    Le Breton, Yoann; McIver, Kevin S.

    2013-01-01

    Streptococcus pyogenes (the group A streptococcus, GAS) is a Gram-positive bacterium responsible for a wide spectrum of diseases ranging from mild superficial infections (pharyngitis, impetigo) to severe often life-threatening invasive diseases (necrotizing fasciitis, streptococcal toxic shock syndrome) in humans. This unit describes molecular techniques for the genetic manipulation of S. pyogenes with detailed protocols for transformation, gene disruption, allelic exchange, transposon mutagenesis, and genetic complementation. PMID:24510894

  9. Genetic manipulation of Streptococcus pyogenes (the Group A Streptococcus, GAS).

    PubMed

    Le Breton, Yoann; McIver, Kevin S

    2013-10-02

    Streptococcus pyogenes (the Group A Streptococcus, GAS) is a Gram-positive bacterium responsible for a wide spectrum of diseases ranging from mild superficial infections (pharyngitis, impetigo) to severe, often life-threatening invasive diseases (necrotizing fasciitis, streptococcal toxic shock syndrome) in humans. This unit describes molecular techniques for the genetic manipulation of S. pyogenes with detailed protocols for transformation, gene disruption, allelic exchange, transposon mutagenesis, and genetic complementation.

  10. Identification of Streptococcus bovis and Streptococcus salivarius in clinical laboratories.

    PubMed

    Ruoff, K L; Ferraro, M J; Holden, J; Kunz, L J

    1984-08-01

    Streptococci identified as Streptococcus bovis, S. bovis variant, and Streptococcus salivarius were examined with respect to physiological and serological characteristics and cellular fatty acid content. Similarities in physiological reactions and problems encountered in serological analysis were noted, suggesting that an expanded battery of physiological tests is needed to definitively identify these streptococci. Cellular fatty acid analysis provided an accurate method for distinguishing S. salivarius from S. bovis and S. bovis variant.

  11. Mutacins of Streptococcus mutans

    PubMed Central

    Kamiya, Regianne Umeko; Taiete, Tiago; Gonçalves, Reginaldo Bruno

    2011-01-01

    The colonization and accumulation of Streptococcus mutans are influenced by various factors in the oral cavity, such as nutrition and hygiene conditions of the host, salivary components, cleaning power and salivary flow and characteristics related with microbial virulence factors. Among these virulence factors, the ability to synthesize glucan of adhesion, glucan-binding proteins, lactic acid and bacteriocins could modify the infection process and pathogenesis of this species in the dental biofilm. This review will describe the role of mutacins in transmission, colonization, and/or establishment of S. mutans, the major etiological agent of human dental caries. In addition, we will describe the method for detecting the production of these inhibitory substances in vitro (mutacin typing), classification and diversity of mutacins and the regulatory mechanisms related to its synthesis. PMID:24031748

  12. [Streptococcus pyogenes pathogenic factors].

    PubMed

    Bidet, Ph; Bonacorsi, S

    2014-11-01

    The pathogenicity of ß-hemolytic group A streptococcus (GAS) is particularly diverse, ranging from mild infections, such as pharyngitis or impetigo, to potentially debilitating poststreptococcal diseases, and up to severe invasive infections such as necrotizing fasciitis or the dreaded streptococcal toxic shock syndrome. This variety of clinical expressions, often radically different in individuals infected with the same strain, results from a complex interaction between the bacterial virulence factors, the mode of infection and the immune system of the host. Advances in comparative genomics have led to a better understanding of how, following this confrontation, GAS adapts to the immune system's pressure, either peacefully by reducing the expression of certain virulence factors to achieve an asymptomatic carriage, or on the contrary, by overexpressing them disproportionately, resulting in the most severe forms of invasive infection.

  13. Streptococcus suis infection

    PubMed Central

    Feng, Youjun; Zhang, Huimin; Wu, Zuowei; Wang, Shihua; Cao, Min; Hu, Dan; Wang, Changjun

    2014-01-01

    Streptococcus suis (S. suis) is a family of pathogenic gram-positive bacterial strains that represents a primary health problem in the swine industry worldwide. S. suis is also an emerging zoonotic pathogen that causes severe human infections clinically featuring with varied diseases/syndromes (such as meningitis, septicemia, and arthritis). Over the past few decades, continued efforts have made significant progress toward better understanding this zoonotic infectious entity, contributing in part to the elucidation of the molecular mechanism underlying its high pathogenicity. This review is aimed at presenting an updated overview of this pathogen from the perspective of molecular epidemiology, clinical diagnosis and typing, virulence mechanism, and protective antigens contributing to its zoonosis. PMID:24667807

  14. Streptococcus zooepidemicus and Streptococcus equi evolution: the role of CRISPRs.

    PubMed

    Waller, Andrew S; Robinson, Carl

    2013-12-01

    The host-restricted bacterium Streptococcus equi is the causative agent of equine strangles, the most frequently diagnosed infectious disease of horses worldwide. The disease is characterized by abscessation of the lymph nodes of the head and neck, leading to significant welfare and economic cost. S. equi is believed to have evolved from an ancestral strain of Streptococcus zooepidemicus, an opportunistic pathogen of horses and other animals. Comparison of the genome of S. equi strain 4047 with those of S. zooepidemicus identified examples of gene loss due to mutation and deletion, and gene gain through the acquisition of mobile genetic elements that have probably shaped the pathogenic specialization of S. equi. In particular, deletion of the CRISPR (clustered regularly interspaced short palindromic repeats) locus in the ancestor of S. equi may have predisposed the bacterium to acquire and incorporate new genetic material into its genome. These include four prophages and a novel integrative conjugative element. The virulence cargo carried by these mobile genetic elements is believed to have shaped the ability of S. equi to cause strangles. Further sequencing of S. zooepidemicus has highlighted the diversity of this opportunistic pathogen. Again, CRISPRs are postulated to influence evolution, balancing the need for gene gain over genome stability. Analysis of spacer sequences suggest that these pathogens may be susceptible to a limited range of phages and provide further evidence of cross-species exchange of genetic material among Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus dysgalactiae.

  15. A Highly Arginolytic Streptococcus Species That Potently Antagonizes Streptococcus mutans

    PubMed Central

    Huang, Xuelian; Palmer, Sara R.; Ahn, Sang-Joon; Richards, Vincent P.; Williams, Matthew L.; Nascimento, Marcelle M.

    2016-01-01

    The ability of certain oral biofilm bacteria to moderate pH through arginine metabolism by the arginine deiminase system (ADS) is a deterrent to the development of dental caries. Here, we characterize a novel Streptococcus strain, designated strain A12, isolated from supragingival dental plaque of a caries-free individual. A12 not only expressed the ADS pathway at high levels under a variety of conditions but also effectively inhibited growth and two intercellular signaling pathways of the dental caries pathogen Streptococcus mutans. A12 produced copious amounts of H2O2 via the pyruvate oxidase enzyme that were sufficient to arrest the growth of S. mutans. A12 also produced a protease similar to challisin (Sgc) of Streptococcus gordonii that was able to block the competence-stimulating peptide (CSP)–ComDE signaling system, which is essential for bacteriocin production by S. mutans. Wild-type A12, but not an sgc mutant derivative, could protect the sensitive indicator strain Streptococcus sanguinis SK150 from killing by the bacteriocins of S. mutans. A12, but not S. gordonii, could also block the XIP (comX-inducing peptide) signaling pathway, which is the proximal regulator of genetic competence in S. mutans, but Sgc was not required for this activity. The complete genome sequence of A12 was determined, and phylogenomic analyses compared A12 to streptococcal reference genomes. A12 was most similar to Streptococcus australis and Streptococcus parasanguinis but sufficiently different that it may represent a new species. A12-like organisms may play crucial roles in the promotion of stable, health-associated oral biofilm communities by moderating plaque pH and interfering with the growth and virulence of caries pathogens. PMID:26826230

  16. A Highly Arginolytic Streptococcus Species That Potently Antagonizes Streptococcus mutans.

    PubMed

    Huang, Xuelian; Palmer, Sara R; Ahn, Sang-Joon; Richards, Vincent P; Williams, Matthew L; Nascimento, Marcelle M; Burne, Robert A

    2016-01-29

    The ability of certain oral biofilm bacteria to moderate pH through arginine metabolism by the arginine deiminase system (ADS) is a deterrent to the development of dental caries. Here, we characterize a novel Streptococcus strain, designated strain A12, isolated from supragingival dental plaque of a caries-free individual. A12 not only expressed the ADS pathway at high levels under a variety of conditions but also effectively inhibited growth and two intercellular signaling pathways of the dental caries pathogen Streptococcus mutans. A12 produced copious amounts of H2O2 via the pyruvate oxidase enzyme that were sufficient to arrest the growth of S. mutans. A12 also produced a protease similar to challisin (Sgc) of Streptococcus gordonii that was able to block the competence-stimulating peptide (CSP)-ComDE signaling system, which is essential for bacteriocin production by S. mutans. Wild-type A12, but not an sgc mutant derivative, could protect the sensitive indicator strain Streptococcus sanguinis SK150 from killing by the bacteriocins of S. mutans. A12, but not S. gordonii, could also block the XIP (comX-inducing peptide) signaling pathway, which is the proximal regulator of genetic competence in S. mutans, but Sgc was not required for this activity. The complete genome sequence of A12 was determined, and phylogenomic analyses compared A12 to streptococcal reference genomes. A12 was most similar to Streptococcus australis and Streptococcus parasanguinis but sufficiently different that it may represent a new species. A12-like organisms may play crucial roles in the promotion of stable, health-associated oral biofilm communities by moderating plaque pH and interfering with the growth and virulence of caries pathogens.

  17. Molecular pathogenicity of Streptococcus anginosus.

    PubMed

    Asam, D; Spellerberg, B

    2014-08-01

    Streptococcus anginosus and the closely related species Streptococcus constellatus and Streptococcus intermedius, are primarily commensals of the mucosa. The true pathogenic potential of this group has been under-recognized for a long time because of difficulties in correct species identification as well as the commensal nature of these species. In recent years, streptococci of the S. anginosus group have been increasingly found as relevant microbial pathogens in abscesses and blood cultures and they play a pathogenic role in cystic fibrosis. Several international studies have shown a surprisingly high frequency of infections caused by the S. anginosus group. Recent studies and a genome-wide comparative analysis suggested the presence of multiple putative virulence factors that are well-known from other streptococcal species. However, very little is known about the molecular basis of pathogenicity in these bacteria. This review summarizes our current knowledge of pathogenicity factors and their regulation in S. anginosus.

  18. Streptococcus Adherence and Colonization

    PubMed Central

    Nobbs, Angela H.; Lamont, Richard J.; Jenkinson, Howard F.

    2009-01-01

    Summary: Streptococci readily colonize mucosal tissues in the nasopharynx; the respiratory, gastrointestinal, and genitourinary tracts; and the skin. Each ecological niche presents a series of challenges to successful colonization with which streptococci have to contend. Some species exist in equilibrium with their host, neither stimulating nor submitting to immune defenses mounted against them. Most are either opportunistic or true pathogens responsible for diseases such as pharyngitis, tooth decay, necrotizing fasciitis, infective endocarditis, and meningitis. Part of the success of streptococci as colonizers is attributable to the spectrum of proteins expressed on their surfaces. Adhesins enable interactions with salivary, serum, and extracellular matrix components; host cells; and other microbes. This is the essential first step to colonization, the development of complex communities, and possible invasion of host tissues. The majority of streptococcal adhesins are anchored to the cell wall via a C-terminal LPxTz motif. Other proteins may be surface anchored through N-terminal lipid modifications, while the mechanism of cell wall associations for others remains unclear. Collectively, these surface-bound proteins provide Streptococcus species with a “coat of many colors,” enabling multiple intimate contacts and interplays between the bacterial cell and the host. In vitro and in vivo studies have demonstrated direct roles for many streptococcal adhesins as colonization or virulence factors, making them attractive targets for therapeutic and preventive strategies against streptococcal infections. There is, therefore, much focus on applying increasingly advanced molecular techniques to determine the precise structures and functions of these proteins, and their regulatory pathways, so that more targeted approaches can be developed. PMID:19721085

  19. Development of primer sets for loop-mediated isothermal amplification that enables rapid and specific detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae

    USDA-ARS?s Scientific Manuscript database

    Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three ...

  20. Population structure of Streptococcus oralis

    PubMed Central

    Do, Thuy; Jolley, Keith A.; Maiden, Martin C. J.; Gilbert, Steven C.; Clark, Douglas; Wade, William G.; Beighton, David

    2009-01-01

    Streptococcus oralis is a member of the normal human oral microbiota, capable of opportunistic pathogenicity; like related oral streptococci, it exhibits appreciable phenotypic and genetic variation. A multilocus sequence typing (MLST) scheme for S. oralis was developed and the resultant data analysed to examine the population structure of the species. Analysis of 113 isolates, confirmed as belonging to the S. oralis/mitis group by 16S rRNA gene sequencing, characterized the population as highly diverse and undergoing inter- and intra-species recombination with a probable clonal complex structure. ClonalFrame analysis of these S. oralis isolates along with examples of Streptococcus pneumoniae, Streptococcus mitis and Streptococcus pseudopneumoniae grouped the named species into distinct, coherent populations and did not support the clustering of S. pseudopneumoniae with S. mitis as reported previously using distance-based methods. Analysis of the individual loci suggested that this discrepancy was due to the possible hybrid nature of S. pseudopneumoniae. The data are available on the public MLST website (http://pubmlst.org/soralis/). PMID:19423627

  1. Recombination-deficient Streptococcus sanguis

    SciTech Connect

    Daneo-Moore, L.; Volpe, A.

    1985-05-01

    A UV-sensitive derivative was obtained from Streptococcus sanguis Challis. The organism could be transformed with a number of small streptococcal plasmids at frequencies equal to, or 1 logarithm below, the transformation frequencies for the parent organism. However, transformation with chromosomal DNA was greatly impaired in the UV-sensitive derivative.

  2. Gene Repertoire Evolution of Streptococcus pyogenes Inferred from Phylogenomic Analysis with Streptococcus canis and Streptococcus dysgalactiae

    PubMed Central

    Lefébure, Tristan; Richards, Vince P.; Lang, Ping; Pavinski-Bitar, Paulina; Stanhope, Michael J.

    2012-01-01

    Streptococcus pyogenes, is an important human pathogen classified within the pyogenic group of streptococci, exclusively adapted to the human host. Our goal was to employ a comparative evolutionary approach to better understand the genomic events concomitant with S. pyogenes human adaptation. As part of ascertaining these events, we sequenced the genome of one of the potential sister species, the agricultural pathogen S. canis, and combined it in a comparative genomics reconciliation analysis with two other closely related species, Streptococcus dysgalactiae and Streptococcus equi, to determine the genes that were gained and lost during S. pyogenes evolution. Genome wide phylogenetic analyses involving 15 Streptococcus species provided convincing support for a clade of S. equi, S. pyogenes, S. dysgalactiae, and S. canis and suggested that the most likely S. pyogenes sister species was S. dysgalactiae. The reconciliation analysis identified 113 genes that were gained on the lineage leading to S. pyogenes. Almost half (46%) of these gained genes were phage associated and 14 showed significant matches to experimentally verified bacteria virulence factors. Subsequent to the origin of S. pyogenes, over half of the phage associated genes were involved in 90 different LGT events, mostly involving different strains of S. pyogenes, but with a high proportion involving the horse specific pathogen S. equi subsp. equi, with the directionality almost exclusively (86%) in the S. pyogenes to S. equi direction. Streptococcus agalactiae appears to have played an important role in the evolution of S. pyogenes with a high proportion of LGTs originating from this species. Overall the analysis suggests that S. pyogenes adaptation to the human host was achieved in part by (i) the integration of new virulence factors (e.g. speB, and the sal locus) and (ii) the construction of new regulation networks (e.g. rgg, and to some extent speB). PMID:22666370

  3. Linkage Analyses of Extracellular Glucans from Streptococcus sanguis and Streptococcus mitior

    PubMed Central

    Freedman, M.; Birkhed, D.; Coykendall, A.; Rizzo, D.

    1979-01-01

    Similar α-(1→6) linkage-rich, soluble, extracellular glucans have been isolated from six strains of two genetically distinct groups of Streptococcus sanguis and three strains of Streptococcus mitior. PMID:457265

  4. First Isolation of Streptococcus halichoeri and Streptococcus phocae from a Steller Sea Lion (Eumetopias jubatus) in South Korea.

    PubMed

    Lee, Kichan; Kim, Ji-Yeon; Jung, Suk Chan; Lee, Hee-Soo; Her, Moon; Chae, Chanhee

    2016-01-01

    Streptococcus species are emerging potential pathogens in marine mammals. We report the isolation and identification of Streptococcus halichoeri and Streptococcus phocae in a Steller sea lion (Eumetopias jubatus) in South Korea.

  5. GLYOXYLATE FERMENTATION BY STREPTOCOCCUS ALLANTOICUS

    PubMed Central

    Valentine, R. C.; Drucker, H.; Wolfe, R. S.

    1964-01-01

    Valentine, R. C. (University of Illinois, Urbana), H. Drucker, and R. S. Wolfe. Glyoxylate fermentation by Streptococcus allantoicus. J. Bacteriol. 87:241–246. 1964.—Extracts of Streptococcus allantoicus were found to degrade glyoxylate, yielding tartronic semialdehyde and CO2. Tartronic semialdehyde was prepared chemically, and its properties were compared with the enzymatic product: reduction by sodium borohydride yielded glycerate; heating at 100 C yielded glycolaldehyde and CO2; autoxidation yielded mesoxalic semialdehyde; periodate oxidation yielded glyoxylate and a compound presumed to be formate. Tartronic semialdehyde reductase was present in extracts of S. allantoicus and in a species of Pseudomonas grown on allantoin. A scheme for the synthesis of acetate from glyoxylate by S. allantoicus is discussed. PMID:14151040

  6. Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus ("Streptococcus milleri group") are of different clinical importance and are not equally associated with abscess.

    PubMed

    Claridge, J E; Attorri, S; Musher, D M; Hebert, J; Dunbar, S

    2001-05-15

    Difficulties in distinguishing organisms of the "Streptococcus milleri group" (SMG; Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus), have caused ambiguity in determining their pathogenic potential. We reviewed 118 cases in which SMG isolates had been identified using 16S rDNA sequence. S. constellatus and S. anginosus were isolated far more frequently than was S. intermedius. Nearly all isolates of S. intermedius and most isolates of S. constellatus, but only 19% of those of S. anginosus, were associated with abscess. Our findings suggest that speciation of the SMG may guide diagnostic evaluation, give insight into the possible role of coinfecting organisms, and help assess the need to search for occult abscess.

  7. Streptococcus tangierensis sp. nov. and Streptococcus cameli sp. nov., two novel Streptococcus species isolated from raw camel milk in Morocco.

    PubMed

    Kadri, Zaina; Vandamme, Peter; Ouadghiri, Mouna; Cnockaert, Margo; Aerts, Maarten; Elfahime, El Mostafa; Farricha, Omar El; Swings, Jean; Amar, Mohamed

    2015-02-01

    Biochemical and molecular genetic studies were performed on two unidentified Gram-stain positive, catalase and oxidase negative, non-hemolytic Streptococcus-like organisms recovered from raw camel milk in Morocco. Phenotypic characterization and comparative 16S rRNA gene sequencing demonstrated that the two strains were highly different from each other and that they did not correspond to any recognized species of the genus Streptococcus. Phylogenetic analysis based on 16S rRNA gene sequences showed the unidentified organisms each formed a hitherto unknown sub-line within the genus Streptococcus, displaying a close affinity with Streptococcus moroccensis, Streptococcus minor and Streptococcus ovis. DNA G+C content determination, MALDI-TOF mass spectrometry and biochemical tests demonstrated the bacterial isolates represent two novel species. Based on the phenotypic distinctiveness of the new bacteria and molecular genetic evidence, it is proposed to classify the two strains as Streptococcus tangierensis sp. nov., with CCMM B832(T) (=LMG 27683(T)) as the type strain, and Streptococcus cameli sp. nov., with CCMM B834(T) (=LMG 27685(T)) as the type strain.

  8. Streptococcus salivarius K12 Limits Group B Streptococcus Vaginal Colonization

    PubMed Central

    Patras, Kathryn A.; Wescombe, Philip A.; Rösler, Berenice; Hale, John D.; Tagg, John R.

    2015-01-01

    Streptococcus agalactiae (group B streptococcus [GBS]) colonizes the rectovaginal tract in 20% to 30% of women and during pregnancy can be transmitted to the newborn, causing severe invasive disease. Current routine screening and antibiotic prophylaxis have fallen short of complete prevention of GBS transmission, and GBS remains a leading cause of neonatal infection. We have investigated the ability of Streptococcus salivarius, a predominant member of the native human oral microbiota, to control GBS colonization. Comparison of the antibacterial activities of multiple S. salivarius strains by use of a deferred-antagonism test showed that S. salivarius strain K12 exhibited the broadest spectrum of activity against GBS. K12 effectively inhibited all GBS strains tested, including disease-implicated isolates from newborns and colonizing isolates from the vaginal tract of pregnant women. Inhibition was dependent on the presence of megaplasmid pSsal-K12, which encodes the bacteriocins salivaricin A and salivaricin B; however, in coculture experiments, GBS growth was impeded by K12 independently of the megaplasmid. We also demonstrated that K12 adheres to and invades human vaginal epithelial cells at levels comparable to GBS. Inhibitory activity of K12 was examined in vivo using a mouse model of GBS vaginal colonization. Mice colonized with GBS were treated vaginally with K12. K12 administration significantly reduced GBS vaginal colonization in comparison to nontreated controls, and this effect was partially dependent on the K12 megaplasmid. Our results suggest that K12 may have potential as a preventative therapy to control GBS vaginal colonization and thereby prevent its transmission to the neonate during pregnancy. PMID:26077762

  9. Streptococcus salivarius K12 Limits Group B Streptococcus Vaginal Colonization.

    PubMed

    Patras, Kathryn A; Wescombe, Philip A; Rösler, Berenice; Hale, John D; Tagg, John R; Doran, Kelly S

    2015-09-01

    Streptococcus agalactiae (group B streptococcus [GBS]) colonizes the rectovaginal tract in 20% to 30% of women and during pregnancy can be transmitted to the newborn, causing severe invasive disease. Current routine screening and antibiotic prophylaxis have fallen short of complete prevention of GBS transmission, and GBS remains a leading cause of neonatal infection. We have investigated the ability of Streptococcus salivarius, a predominant member of the native human oral microbiota, to control GBS colonization. Comparison of the antibacterial activities of multiple S. salivarius strains by use of a deferred-antagonism test showed that S. salivarius strain K12 exhibited the broadest spectrum of activity against GBS. K12 effectively inhibited all GBS strains tested, including disease-implicated isolates from newborns and colonizing isolates from the vaginal tract of pregnant women. Inhibition was dependent on the presence of megaplasmid pSsal-K12, which encodes the bacteriocins salivaricin A and salivaricin B; however, in coculture experiments, GBS growth was impeded by K12 independently of the megaplasmid. We also demonstrated that K12 adheres to and invades human vaginal epithelial cells at levels comparable to GBS. Inhibitory activity of K12 was examined in vivo using a mouse model of GBS vaginal colonization. Mice colonized with GBS were treated vaginally with K12. K12 administration significantly reduced GBS vaginal colonization in comparison to nontreated controls, and this effect was partially dependent on the K12 megaplasmid. Our results suggest that K12 may have potential as a preventative therapy to control GBS vaginal colonization and thereby prevent its transmission to the neonate during pregnancy. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  10. Group A Streptococcus vulvovaginitis in breastfeeding women.

    PubMed

    Rahangdale, Lisa; Lacy, Judith; Hillard, Paula A

    2008-08-01

    Group A beta-hemolytic streptococcus-associated vulvovaginitis is uncommon in adult women. Clinicians should include group A beta-hemolytic streptococcus as a possible cause of vulvovaginal symptoms in breastfeeding women. Along with appropriate antibiotic therapy, vaginal estrogen therapy may be considered to diminish susceptibility to recurrent infection in women with vaginal atrophy.

  11. Group G Streptococcus bacteremia in recurrent cellulitis.

    PubMed

    di Meo, Nicola; Stinco, Giuseppe; Gubertini, Nicoletta; Patriarca, Maria Martina; Trevisan, Giusto

    2014-01-01

    In recent years, group G Streptococcus has been reported with increasing frequency as the cause of a variety of human infections. Underlying host factors such as immunosuppression, malignancy, diabetes mellitus, and rheumatoid arthritis may be predisposing conditions leading to infection. Toxic involvement and post-streptococcal sequalae, once believed to be exclusive to infections caused by group A Streptococcus, are now known to occur following acute group G Streptococcus and group C Streptococcus infections. We report on a case of group G Streptococcus bacteremia and recurrent cellulitis with toxic involvement. Patient blood cultures were always negative for β-hemolytic Streptococci in all the recurrences, except during the last one. Antibiotic therapy based on antibiogram quickly resolved the infection. A regimen of intramuscular injection of 1.2 million units of benzathine penicillin every 15 days for one year prevented recurrences of cellulitis.

  12. Streptococcus milleri in the appendix.

    PubMed Central

    Poole, P M; Wilson, G

    1977-01-01

    The appendix was investigated as a possible habitat of Streptococcus milleri. Both normal and inflamed appendices were examined and the isolation rates compared. S. milleri was present in a quarter of the normal appendices and more than half of those associated with apendicitis--a difference that was statistically highly significant. The isolation rates throughout were indepencent of age. There was a pronounced connection between the presence of S. milleri in the appendix and the purulent manifestations of appendicitis. S. milleri was isolated from other abdominal sites associated with appendicitis. The frequency of isolation was increased by culture in an enrichment broth containing nalidixic acid and sulphadimidine. PMID:591633

  13. Streptococcus milleri in the appendix.

    PubMed

    Poole, P M; Wilson, G

    1977-10-01

    The appendix was investigated as a possible habitat of Streptococcus milleri. Both normal and inflamed appendices were examined and the isolation rates compared. S. milleri was present in a quarter of the normal appendices and more than half of those associated with apendicitis--a difference that was statistically highly significant. The isolation rates throughout were indepencent of age. There was a pronounced connection between the presence of S. milleri in the appendix and the purulent manifestations of appendicitis. S. milleri was isolated from other abdominal sites associated with appendicitis. The frequency of isolation was increased by culture in an enrichment broth containing nalidixic acid and sulphadimidine.

  14. Polyarteritis nodosa associated with streptococcus.

    PubMed Central

    David, J; Ansell, B M; Woo, P

    1993-01-01

    Twelve children are described with an essentially benign vasculitic illness in association with streptococcal infection. They demonstrated characteristic clinical features of nodular cutaneous polyarteritis with fever. Laboratory findings showed an acute phase response associated with raised antistreptolysin and antihyaluronidase titres in all patients and a positive throat culture for beta haemolytic streptococcus in three patients. Ten required corticosteroids. Two patients had systemic involvement with abnormal arteriography; both had appreciably raised white cell counts (> 40 x 10(9)/l). They may represent a subset of poststreptococcal vasculitis, requiring cytotoxic treatment for effective disease control. Images PMID:7904442

  15. STARCH HYDROLYSIS BY STREPTOCOCCUS EQUINUS

    PubMed Central

    Dunican, Lawrence K.; Seeley, Harry W.

    1962-01-01

    Dunican, Lawrence K. (Cornell University, Ithaca, N. Y.) and Harry W. Seeley. Starch hydrolysis by Streptococcus equinus. J. Bacteriol. 82:264–269. 1962.—In a study of starch hydrolysis by strains of Streptococcus equinus, 52 isolates were obtained and their amylolytic abilities determined. It was found that all the strains could hydrolyze starch to some extent when grown in the presence of an easily fermentable carbohydrate, viz., glucose. Without this carbohydrate the organisms did not hydrolyze starch. The hydrolysis of starch was inhibited when the organisms were grown in an atmosphere of 5% CO2 and 95% N2, even if grown in the presence of a fermentable monosaccharide. S. bovis, which was used as a reference organism, readily hydrolyzed starch in the absence of monosaccharides and in atmospheres containing CO2. In no instance did S. equinus hydrolyze the starch to the level of reducing sugars. Negligible amounts of reducing sugars were recovered when the cell-free filtrates of S. equinus were incubated with starch. With S. bovis, the yield of reducing sugars under such conditions was almost quantitative. These facts extend further the differences between these related organisms. The ability to synthesize an internal starchlike polysaccharide was noted in most of the strains of S. equinus. Synthesis was found when the organisms were grown on maltose or on a starch medium containing a small amount of fermentable monosaccharide. PMID:13888473

  16. Streptococcus pyogenes adhesion and colonization.

    PubMed

    Brouwer, Stephan; Barnett, Timothy C; Rivera-Hernandez, Tania; Rohde, Manfred; Walker, Mark J

    2016-11-01

    Streptococcus pyogenes (group A Streptococcus, GAS) is a human-adapted pathogen responsible for a wide spectrum of disease. GAS can cause relatively mild illnesses, such as strep throat or impetigo, and less frequent but severe life-threatening diseases such as necrotizing fasciitis and streptococcal toxic shock syndrome. GAS is an important public health problem causing significant morbidity and mortality worldwide. The main route of GAS transmission between humans is through close or direct physical contact, and particularly via respiratory droplets. The upper respiratory tract and skin are major reservoirs for GAS infections. The ability of GAS to establish an infection in the new host at these anatomical sites primarily results from two distinct physiological processes, namely bacterial adhesion and colonization. These fundamental aspects of pathogenesis rely upon a variety of GAS virulence factors, which are usually under strict transcriptional regulation. Considerable progress has been made in better understanding these initial infection steps. This review summarizes our current knowledge of the molecular mechanisms of GAS adhesion and colonization. © 2016 Federation of European Biochemical Societies.

  17. Streptococcus agalactiae mastitis: a review.

    PubMed Central

    Keefe, G P

    1997-01-01

    Streptococcus agalactiae continues to be a major cause of subclinical mastitis in dairy cattle and a source of economic loss for the industry. Veterinarians are often asked to provide information on herd level control and eradication of S. agalactiae mastitis. This review collects and collates relevant publications on the subject. The literature search was conducted in 1993 on the Agricola database. Articles related to S. agalactiae epidemiology, pathogen identification techniques, milk quality consequences, and control, prevention, and therapy were included. Streptococcus agalactiae is an oblique parasite of the bovine mammary gland and is susceptible to treatment with a variety of antibiotics. Despite this fact, where state or provincial census data are available, herd prevalence levels range from 11% (Alberta, 1991) to 47% (Vermont, 1985). Infection with S. agalactiae is associated with elevated somatic cell count and total bacteria count and a decrease in the quantity and quality of milk products produced. Bulk tank milk culture has, using traditional milk culture techniques, had a low sensitivity for identifying S. agalactiae at the herd level. New culture methods, using selective media and large inocula, have substantially improved the sensitivity of bulk tank culture. Efficacy of therapy on individual cows remains high. Protocols for therapy of all infected animals in a herd are generally successful in eradicating the pathogen from the herd, especially if they are followed up with good udder hygiene techniques. PMID:9220132

  18. Streptococcus agalactiae Toxic Shock-Like Syndrome

    PubMed Central

    Al Akhrass, Fadi; Abdallah, Lina; Berger, Steven; Hanna, Rami; Reynolds, Nina; Thompson, Shellie; Hallit, Rabih; Schlievert, Patrick M.

    2013-01-01

    Abstract We present 2 patients with Streptococcus agalactiae toxic shock-like syndrome and review another 11 well-reported cases from the literature. Streptococcal toxic shock-like syndrome is a devastating illness with a high mortality rate, therefore we stress the importance of early supportive management, antimicrobial therapy, and surgical intervention. Toxic shock-like syndrome is likely to be underestimated in patients with invasive Streptococcus agalactiae infection who present with shock. Early diagnosis requires high suspicion of the illness, along with a thorough mucocutaneous examination. Streptococcus agalactiae produces uncharacterized pyrogenic toxins, which explains the ability of the organism to cause toxic shock-like syndrome. PMID:23263717

  19. Streptococcus pyogenes in Human Plasma

    PubMed Central

    Malmström, Johan; Karlsson, Christofer; Nordenfelt, Pontus; Ossola, Reto; Weisser, Hendrik; Quandt, Andreas; Hansson, Karin; Aebersold, Ruedi; Malmström, Lars; Björck, Lars

    2012-01-01

    Streptococcus pyogenes is a major bacterial pathogen and a potent inducer of inflammation causing plasma leakage at the site of infection. A combination of label-free quantitative mass spectrometry-based proteomics strategies were used to measure how the intracellular proteome homeostasis of S. pyogenes is influenced by the presence of human plasma, identifying and quantifying 842 proteins. In plasma the bacterium modifies its production of 213 proteins, and the most pronounced change was the complete down-regulation of proteins required for fatty acid biosynthesis. Fatty acids are transported by albumin (HSA) in plasma. S. pyogenes expresses HSA-binding surface proteins, and HSA carrying fatty acids reduced the amount of fatty acid biosynthesis proteins to the same extent as plasma. The results clarify the function of HSA-binding proteins in S. pyogenes and underline the power of the quantitative mass spectrometry strategy used here to investigate bacterial adaptation to a given environment. PMID:22117078

  20. Towards Control of Streptococcus iniae

    PubMed Central

    Barnes, Andrew C.

    2009-01-01

    Streptococcus iniae is an emerging zoonotic pathogen; such infections generally occur through injuries associated with preparing whole fresh fish for cooking. Those infected to date have been of Asian descent, are usually elderly (average age 68 years), and have had >1 underlying conditions that may predispose them to infection. Studies of the foundations of growth characteristics of S. iniae and its interactions with piscine host cells have recently been complemented by molecular studies. Advances in molecular biology have allowed research groups to identify numerous virulence factors and to explore their roles in the progression of S. iniae infection. Many of these virulence factors are homologous to those found in the major human pathogen S. pyogenes. An increased understanding of the properties of these factors and their effect on the success of infection is leading to novel approaches to control S. iniae infection; in particular, vaccination programs at fish farms have reduced the reservoir of infection for additional clinical cases. PMID:19961667

  1. Pneumonia and Streptococcus pneumoniae vaccine.

    PubMed

    Kim, Gyu-Lee; Seon, Seung-Han; Rhee, Dong-Kwon

    2017-07-22

    Pneumonia is an inflammatory disease of the lung, responsible for high morbidity and mortality worldwide. It is caused by bacteria, viruses, fungi, or other microorganisms. Streptococcus pneumoniae, a gram-positive bacterium with over 90 serotypes, is the most common causative agent. Moreover, comorbid factors including heart failure, renal disease, and pulmonary disease could increase the risk of pneumococcal pneumonia. Since the advent of the pneumococcal vaccine in the 1980s, the incidence of pneumonia has decreased significantly. However, current vaccines confer only limited protection against serotypes included in the vaccine. Thus, to overcome this limitation, new types of pneumococcal vaccines have been sought and under clinical trials. In this review, we discuss pneumonia and summarize the various types of pneumococcal vaccines in progress.

  2. Infections Associated with Streptococcus intermedius in Children.

    PubMed

    Faden, Howard S

    2016-09-01

    Streptococcus intermedius is a viridans Streptococcus belonging to the Anginosus group. In the past 7 years, it has been associated with abscesses in 48 children, 40% of whom had complicated and/or life-threatening illness. It was the sole pathogen in 35 cases. Seventy-five percent of the infections occurred in winter and spring. None occurred in infants younger than 1 year.

  3. The effect of mango and neem extract on four organisms causing dental caries: Streptococcus mutans, Streptococcus salivavius, Streptococcus mitis, and Streptococcus sanguis: an in vitro study.

    PubMed

    Prashant, G M; Chandu, G N; Murulikrishna, K S; Shafiulla, M D

    2007-01-01

    Chewing twigs of the mango or neem tree is a common way of cleaning the teeth in the rural and semi-urban population. These twigs are also believed to possess medicinal properties. The present study was conducted to evaluate the antimicrobial effects of these chewing sticks on the microorganisms Streptococcus mutans , Streptococcus salivarius , Streptococcus mitis , and Streptococcus sanguis which are involved in the development of dental caries. An additional objective was to identify an inexpensive, simple, and effective method of preventing and controlling dental caries. The sticks were sun dried, ground into a coarse powder, and weighed into 5 gm, 10 gm, and 50 gm amounts. These were added to 100 ml of deionized distilled water. After soaking for 48 h at 4 degrees C, the water was filtered. The filtrate was inoculated onto blood agar plates containing individual species of microorganisms and incubated at 37 degrees C for 48 h. Mango extract, at 50% concentration, showed maximum zone of inhibition on Streptococcus mitis . Neem extract produced the maximum zone of inhibition on Streptococcus mutans at 50% concentration. Even at 5% concentration neem extract showed some inhibition of growth for all the four species of organisms. A combination of neem and mango chewing sticks may provide the maximum benefit. We recommend the use of both the chewing sticks.

  4. Isolation of Streptococcus tigurinus - a novel member of Streptococcus mitis group from a case of periodontitis.

    PubMed

    Dhotre, Shree V; Mehetre, Gajanan T; Dharne, Mahesh S; Suryawanshi, Namdev M; Nagoba, Basavraj S

    2014-08-01

    Streptococcus tigurinus is a new member of the Streptococcus viridians group and is closely related to Streptococcus mitis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae, Streptococcus oralis, and Streptococcus infantis. The type strain AZ_3a(T) of S. tigurinus was originally isolated from a patient with infective endocarditis. Accurate identification of S. tigurinus is facilitated only by newer molecular methods like 16S rRNA gene analysis. During the course of study on bacteraemia and infective endocarditis with reference to periodontitis and viridians group of streptococci, a strain of S. tigurinus isolated from subgingival plaque of a patient with periodontitis identified by 16S rRNA gene analysis, which was originally identified as Streptococcus pluranimalium by Vitek 2. Confirmation by 16S rRNA gene analysis showed 99.39% similarity (1476/1485 bp) with S. tigurinus AZ_3a(T) (AORU01000002). To the best of our knowledge, this is the first report of isolation of S. tigurinus from the oral cavity of a periodontitis patient.

  5. Penetration of Streptococcus sobrinus and Streptococcus sanguinis into dental enamel.

    PubMed

    Kneist, Susanne; Nietzsche, Sandor; Küpper, Harald; Raser, Gerhard; Willershausen, Brita; Callaway, Angelika

    2015-10-01

    The aim of this pilot study was to assess the difference in virulence of acidogenic and aciduric oral streptococci in an in vitro caries model using their penetration depths into dental enamel. 30 caries-free extracted molars from 11- to 16-year-olds were cleaned ultrasonically for 1 min with de-ionized water and, after air-drying, embedded in epoxy resin. After 8-h of setting at room temperature, the specimens were ground on the buccal side with SiC-paper 1200 (particle size 13-16 μm). Enamel was removed in circular areas sized 3 mm in diameter; the mean depth of removed enamel was 230 ± 60 μm. 15 specimens each were incubated anaerobically under standardized conditions with 24 h-cultures of Streptococcus sanguinis 9S or Streptococcus sobrinus OMZ 176 in Balmelli broth at 37 ± 2 °C; the pH-values of the broths were measured at the beginning and end of each incubation cycle. After 2, 4, 6, 8, and 10 weeks 3 teeth each were fixed in 2.5% glutaraldehyde in cacodylate buffer for 24 h, washed 3× and dehydrated 30-60min by sequential washes through a series of 30-100% graded ethanol. The teeth were cut in half longitudinally; afterward, two slits were made to obtain fracture surfaces in the infected area. After critical-point-drying the fragments were gold-sputtered and viewed in a scanning electron microscope at magnifications of ×20-20,000. After 10 weeks of incubation, penetration of S. sanguinis of 11.13 ± 24.04 μm below the break edges into the enamel was observed. The invasion of S. sobrinus reached depths of 87.53 ± 76.34 μm. The difference was statistically significant (paired t test: p = 0.033). The experimental penetration depths emphasize the importance of S. sanguinis versus S. sobrinus in the context of the extended ecological plaque hypothesis.

  6. 21 CFR 866.3740 - Streptococcus spp. serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3740 Streptococcus spp. serological reagents. (a) Identification. Streptococcus spp. serological reagents are devices... streptococci are associated with infections, such as sore throat, impetigo (an infection characterized by...

  7. Aerobic Metabolism of Streptococcus agalactiae

    PubMed Central

    Mickelson, M. N.

    1967-01-01

    Streptococcus agalactiae cultures possess an aerobic pathway for glucose oxidation that is strongly inhibited by cyanide. The products of glucose oxidation by aerobically grown cells of S. agalactiae 50 are lactic and acetic acids, acetylmethylcarbinol, and carbon dioxide. Glucose degradation products by aerobically grown cells, as percentage of glucose carbon, were 52 to 61% lactic acid, 20 to 23% acetic acid, 5.5 to 6.5% acetylmethylcarbinol, and 14 to 16% carbon dioxide. There was no evidence for a pentose cycle or a tricarboxylic acid cycle. Crude cell-free extracts of S. agalactiae 50 possessed a strong reduced nicotinamide adenine dinucleotide (NADH2) oxidase that is also cyanide-sensitive. Dialysis or ultrafiltration of the crude, cell-free extract resulted in loss of NADH2 oxidase activity. Oxidase activity was restored to the inactive extract by addition of the ultrafiltrate or by addition of menadione or K3Fe(CN)6. Noncytochrome iron-containing pigments were present in cell-free extracts of S. agalactiae. The possible participation of these pigments in the respiration of S. agalactiae is presently being studied. PMID:4291090

  8. Bacteriocin (Hemolysin) of Streptococcus zymogenes

    PubMed Central

    Basinger, Scott F.; Jackson, Robert W.

    1968-01-01

    The sensitivity of Streptococcus faecalis (ATTC 8043) to S. zymogenes X-14 bacteriocin depends greatly on its physiological age. Sensitivity decreases from the mid-log phase on and is completely lost in the stationary phase. The sensitivity of erythrocytes to the hemolytic capacity of the bacteriocin showed considerable species variation. The order of increasing sensitivity was goose < sheep < dog < horse < human < rabbit. However, when red cell stromata were used as inhibitors of hemolysis in a standard system employing rabbit erythrocytes the order of increasing effectiveness was sheep < rabbit < human < horse < goose. When rabbit cells were used in varying concentrations with a constant hemolysin concentration, there was a lag of about 30 min, which for a given hemolysin preparation was constant for all red cell concentrations. Furthermore, the rate of hemolysis increased with increasing red cell concentration. If red cells are held constant and lysin varied, the time to reach half-maximal lysis varies directly with lysin but is not strictly proportional. Bacterial membranes were one to three orders of magnitude more effective than red cell stromata as inhibitors. The order of increasing effectiveness seems to be Escherichia coli < Bacillus megaterium < S. faecalis < Micrococcus lysodeikticus. In addition to membranes, a d-alanine containing glycerol teichoic acid, trypsin in high concentration, and deoxyribonuclease also inhibited hemolysis. Ribonuclease, d-alanine, l-alanine, dl-alanyl-dl-alanine, N-acetyl-d-alanine, N-acetyl-l-alanine did not inhibit hemolysis. PMID:4972910

  9. Macrolide Resistance in Streptococcus pneumoniae

    PubMed Central

    Schroeder, Max R.; Stephens, David S.

    2016-01-01

    Streptococcus pneumoniae is a common commensal and an opportunistic pathogen. Suspected pneumococcal upper respiratory infections and pneumonia are often treated with macrolide antibiotics. Macrolides are bacteriostatic antibiotics and inhibit protein synthesis by binding to the 50S ribosomal subunit. The widespread use of macrolides is associated with increased macrolide resistance in S. pneumoniae, and the treatment of pneumococcal infections with macrolides may be associated with clinical failures. In S. pneumoniae, macrolide resistance is due to ribosomal dimethylation by an enzyme encoded by erm(B), efflux by a two-component efflux pump encoded by mef (E)/mel(msr(D)) and, less commonly, mutations of the ribosomal target site of macrolides. A wide array of genetic elements have emerged that facilitate macrolide resistance in S. pneumoniae; for example erm(B) is found on Tn917, while the mef (E)/mel operon is carried on the 5.4- or 5.5-kb Mega element. The macrolide resistance determinants, erm(B) and mef (E)/mel, are also found on large composite Tn916-like elements most notably Tn6002, Tn2009, and Tn2010. Introductions of 7-valent and 13-valent pneumococcal conjugate vaccines (PCV-7 and PCV-13) have decreased the incidence of macrolide-resistant invasive pneumococcal disease, but serotype replacement and emergence of macrolide resistance remain an important concern. PMID:27709102

  10. Biofilm formation in Streptococcus pneumoniae.

    PubMed

    Domenech, Mirian; García, Ernesto; Moscoso, Miriam

    2012-07-01

    Biofilm-grown bacteria are refractory to antimicrobial agents and show an increased capacity to evade the host immune system. In recent years, studies have begun on biofilm formation by Streptococcus pneumoniae, an important human pathogen, using a variety of in vitro model systems. The bacterial cells in these biofilms are held together by an extracellular matrix composed of DNA, proteins and, possibly, polysaccharide(s). Although neither the precise nature of these proteins nor the composition of the putative polysaccharide(s) is clear, it is known that choline-binding proteins are required for successful biofilm formation. Further, many genes appear to be involved, although the role of each appears to vary when biofilms are produced in batch or continuous culture. Prophylactic and therapeutic measures need to be developed to fight S. pneumoniae biofilm formation. However, much care needs to be taken when choosing strains for such studies because different S. pneumoniae isolates can show remarkable genomic differences. Multispecies and in vivo biofilm models must also be developed to provide a more complete understanding of biofilm formation and maintenance. © 2011 The Authors. Microbial Biotechnology © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  11. Biofilm formation in Streptococcus pneumoniae

    PubMed Central

    Domenech, Mirian; García, Ernesto; Moscoso, Miriam

    2012-01-01

    Summary Biofilm‐grown bacteria are refractory to antimicrobial agents and show an increased capacity to evade the host immune system. In recent years, studies have begun on biofilm formation by Streptococcus pneumoniae, an important human pathogen, using a variety of in vitro model systems. The bacterial cells in these biofilms are held together by an extracellular matrix composed of DNA, proteins and, possibly, polysaccharide(s). Although neither the precise nature of these proteins nor the composition of the putative polysaccharide(s) is clear, it is known that choline‐binding proteins are required for successful biofilm formation. Further, many genes appear to be involved, although the role of each appears to vary when biofilms are produced in batch or continuous culture. Prophylactic and therapeutic measures need to be developed to fight S. pneumoniae biofilm formation. However, much care needs to be taken when choosing strains for such studies because different S. pneumoniae isolates can show remarkable genomic differences. Multispecies and in vivo biofilm models must also be developed to provide a more complete understanding of biofilm formation and maintenance. PMID:21906265

  12. Galactokinase activity in Streptococcus thermophilus

    SciTech Connect

    Hutkins, R.; Morris, H.A.; McKay, L.L.

    1985-10-01

    ATP-dependent phosphorylation of (/sup 14/C)galactose by 11 strains of streptococcus thermophilus indicated that these organisms possessed the Leloir enzyme, galactokinase (galK). Activities were 10 times higher in fully induced, galactose-fermenting (Gal/sup +/) strains than in galactose-nonfermenting (Gal/sup -/) strains. Lactose-grown, Gal/sup -/ cells released free galactose into the medium and were unable to utilize residual galactose or to induce galK above basal levels. Gal/sup +/ S. thermophilus 19258 also released galactose into the medium, but when lactose was depleted, growth on galactose commenced, and galK increased from 0.025 to 0.22 ..mu..mol of galactose phosphorylated per min per mg of protein. When lactose was added to galactose-grown cells of S. thermophilus 19258, galK activity rapidly decreased. These results suggest that galK in Gal/sup +/ S. thermophilus is subject to an induction-repression mechanism, but that galK cannot be induced in Gal/sup -/ strains.

  13. The efficacy of neem extract on four microorganisms responsible for causing dental caries viz Streptococcus mutans, Streptococcus salivarius, Streptococcus mitis and Streptococcus sanguis: an in vitro study.

    PubMed

    Chava, Venkateswara Rao; Manjunath, S M; Rajanikanth, A V; Sridevi, N

    2012-11-01

    HISTORY AND OBJECTIVES: From the ancient time, neem used to be the traditional medicine for many diseases and was mainly used for cleaning the oral cavity. The incidence of dental caries was less a few decades ago but now the incidence of caries is very aggressive. This might be due to change in dietary habits, life style and more tendency toward processed food. The objective of this study is to find out the truth that if the neem is really efficacious against caries-inducing microorganisms, mainly Streptococcus mutans, Streptococcus salivarius, Streptococcus mitis and Streptococcus sanguis. The dried neem sticks ground into a coarse powder and weighed into 5, 10 and 50 gm were added to 100 ml of deionized double distilled water. After soaking for 2 days, the water was filtered at 4 °C and the fine filtrate was inoculated onto blood agar plates contains individual species of microorganisms and incubated at 37 °C for 2 days. At maximum concentrations, neem extract has shown the maximum zone of inhibition on Streptococcus mutans. At less concentration, the efficacy of neem has shown some inhibition of growth for all the four species of microorganisms. Neem chewing provides the maximum benefits. Hence, the use of chewing sticks of neem can be recommended.

  14. Distribution of Streptococcus troglodytae and Streptococcus dentirousetti in chimpanzee oral cavities.

    PubMed

    Miyanohara, Mayu; Imai, Susumu; Okamoto, Masaaki; Saito, Wataru; Nomura, Yoshiaki; Momoi, Yasuko; Tomonaga, Masaki; Hanada, Nobuhiro

    2013-05-01

    The aim of this study was to analyze the distribution and phenotypic properties of the indigenous streptococci in chimpanzee (Pan troglodytes) oral cavities. Eleven chimpanzees (aged from 9 to 44 years, mean ± SD, 26.9 ± 12.6 years) in the Primate Research Institute of Kyoto University were enrolled in this research and brushing bacterial samples collected from them. Streptococci were isolated from the oral cavities of all chimpanzees. The isolates (n = 46) were identified as thirteen species by 16S rRNA genes analysis. The predominant species was Streptococcus sanguinis of mitis streptococci from five chimpanzees (45%). Mutans streptococci were isolated from six chimpanzees (55%). The predominant species in the mutans streptococci were Streptococcus troglodytae from four chimpanzees (36%), this species having been proposed as a novel species by us, and Streptococcus dentirousetti from three chimpanzees (27%). Streptococcus mutans was isolated from one chimpanzee (9%). However, Streptococcus sobrinus, Streptococcus macacae and Streptococcus downei, which are indigenous to human and monkey (Macaca fasciclaris) oral habitats, were not isolated. Of the mutans streptococci, S. troglodytae, S. dentirousetti, and S. mutans possessed strong adherence activity to glass surface.

  15. Streptococcus orisasini sp. nov. and Streptococcus dentasini sp. nov., isolated from the oral cavity of donkeys.

    PubMed

    Takada, Kazuko; Saito, Masanori; Tsudukibashi, Osamu; Hiroi, Takachika; Hirasawa, Masatomo

    2013-08-01

    Four Gram-positive, catalase-negative, coccoid isolates that were obtained from donkey oral cavities formed two distinct clonal groups when characterized by phenotypic and phylogenetic studies. From the results of biochemical tests, the organisms were tentatively identified as a streptococcal species. Comparative 16S rRNA gene sequencing studies confirmed the organisms to be members of the genus Streptococcus. Two of the isolates were related most closely to Streptococcus ursoris with 95.6 % similarity based on the 16S rRNA gene and to Streptococcus ratti with 92.0 % similarity based on the 60 kDa heat-shock protein gene (groEL). The other two isolates, however, were related to Streptococcus criceti with 95.0 and 89.0 % similarities based on the 16S rRNA and groEL genes, respectively. From both phylogenetic and phenotypic evidence, the four isolates formed two distinct clonal groups and are suggested to represent novel species of the genus Streptococcus. The names proposed for these organisms are Streptococcus orisasini sp. nov. (type strain NUM 1801(T) = JCM 17942(T) = DSM 25193(T)) and Streptococcus dentasini sp. nov. (type strain NUM 1808(T) = JCM 17943(T) = DSM 25137(T)).

  16. ATP-driven calcium transport in membrane vesicles of Streptococcus sanguis. [Streptococcus sanguis; Streptococcus faecalis; Escherichia coli

    SciTech Connect

    Houng, H.; Lynn, A.R.; Rosen, B.P.

    1986-11-01

    Calcium transport was investigated in membrane vesicles prepared from the oral bacterium Streptococcus sanguis. Procedures were devised for the preparation of membrane vesicles capable of accumulation /sup 45/Ca/sup 2 +/. Uptake was ATP dependent and did not require a proton motive force. Calcium transport in these vesicles was compared with /sup 45/Ca/sup 2 +/ accumulation in membrane vesicles from Streptococcus faecalis and Escherichia coli. The data support the existence of an ATP-driven calcium pump in S. sanguis similar to that in S. faecalis. This pump, which catalyzes uptake into membrane vesicles, would be responsible for extrusion of calcium from intact cells.

  17. MALDI-TOF mass spectrometry for differentiation between Streptococcus pneumoniae and Streptococcus pseudopneumoniae.

    PubMed

    van Prehn, Joffrey; van Veen, Suzanne Q; Schelfaut, Jacqueline J G; Wessels, Els

    2016-05-01

    We compared the Vitek MS and Microflex MALDI-TOF mass spectrometry platform for species differentiation within the Streptococcus mitis group with PCR assays targeted at lytA, Spn9802, and recA as reference standard. The Vitek MS correctly identified 10/11 Streptococcus pneumoniae, 13/13 Streptococcus pseudopneumoniae, and 12/13 S. mitis/oralis. The Microflex correctly identified 9/11 S. pneumoniae, 0/13 S. pseudopneumoniae, and 13/13 S. mitis/oralis. MALDI-TOF is a powerful tool for species determination within the mitis group. Diagnostic accuracy varies depending on platform and database used.

  18. Monoclonal Idiotope Vaccine against Streptococcus pneumoniae Infection

    NASA Astrophysics Data System (ADS)

    McNamara, Mary K.; Ward, Ronald E.; Kohler, Heinz

    1984-12-01

    A monoclonal anti-idiotope antibody coupled to a carrier protein was used to immunize BALB/c mice against a lethal Streptococcus pneumoniae infection. Vaccinated mice developed a high titer of antibody to phosphorylcholine, which is known to protect against infection with Streptococcus pneumoniae. Measurement of the median lethal dose of the bacteria indicated that anti-idiotope immunization significantly increased the resistance of BALB/c mice to the bacterial challenge. Antibody to an idiotope can thus be used as an antigen substitute for the induction of protective immunity.

  19. Differentiation of Listeria and Streptococcus strains.

    PubMed

    Herendi, A; Ralovich, B

    1989-01-01

    Colonial morphology of non-beta haemolytic Listeria strains is frequently similar to that of non-haemolytic streptococci. Biochemical characteristics, motility, haemolysis on ox blood agar, growth on Clauberg, selective streptococcus (Si) and Mitis-Salivarius agar medium, CAMP test, serological behaviour of 16 Listeria strains were studied and the results were compared with the properties of Streptococcus strains. Microscopic morphology, motility and catalase activity are useful for distinguishing these strains. To avoid a false diagnosis, latex-agglutination should be supplemented with the above tests.

  20. Streptococcus anginosus Group Bacterial Infections.

    PubMed

    Fazili, Tasaduq; Riddell, Scott; Kiska, Deanna; Endy, Tim; Giurgea, Luca; Sharngoe, Calden; Javaid, Waleed

    2017-09-01

    The Streptococcus anginosus group (SAG) causes a variety of infections in adults. To better understand the burden of SAG infections and their associated morbidity and mortality, we conducted a retrospective analysis of these infections in adults at a tertiary care center. A retrospective review of all cultures positive for SAG in adults and a corresponding review of the patients' medical records were conducted at a tertiary care facility in central New York. Patients with these cultures during the period of January 2007-December 2011 were included. Demographic data, area of residence, clinical features and underlying illnesses, site of infection, length of hospital stay, antibiotic susceptibility and antibiotic therapy were recorded and analyzed. There were 332 SAG cases; most patients were males (59%), mean age of 47 years and 84% lived in urban areas. Overall mortality was 3% with underlying conditions common such as diabetes (25%), hypertension (31%) and immunodeficiency (22%). Most of the infections were related to skin and soft tissue (72%) and polymicrobial (70%) with gram-negative anaerobes and Enterobacteriaceae commonly isolated with SAG. We present the largest study, thus far, reviewing the clinical presentation, management and outcome of infections due to the SAG of organisms. Notable findings from our study are the low mortality associated with SAG infection, and the propensity to present as a skin and tissue and polymicrobial infection. Our findings will assist clinicians in managing patients with SAG infections and recognizing that S anginosus may be one of several organisms responsible for infection. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  1. Iron acquisition and regulation systems in Streptococcus species.

    PubMed

    Ge, Ruiguang; Sun, Xuesong

    2014-05-01

    Gram-positive Streptococcus species are responsible for millions of cases of meningitis, bacterial pneumonia, endocarditis, erysipelas and necrotizing fasciitis. Iron is essential for the growth and survival of Streptococcus in the host environment. Streptococcus species have developed various mechanisms to uptake iron from an environment with limited available iron. Streptococcus can directly extract iron from host iron-containing proteins such as ferritin, transferrin, lactoferrin and hemoproteins, or indirectly by relying on the employment of specialized secreted hemophores (heme chelators) and small siderophore molecules (high affinity ferric chelators). This review presents the most recent discoveries in the iron acquisition system of Streptococcus species - the transporters as well as the regulators.

  2. Genetic Basis of Antibiotic Resistance in Clinical Isolates of Streptococcus gallolyticus (Streptococcus bovis)

    PubMed Central

    Leclercq, Roland; Huet, Corinne; Picherot, Mélanie; Trieu-Cuot, Patrick; Poyart, Claire

    2005-01-01

    Among 128 Streptococcus gallolyticus (Streptococcus bovis) isolates, 77.7% were resistant to tetracyclines and contained tet(M) and/or tet(L) and/or tet(O). A total of 59.4% had macrolide resistance and contained erm(B) and, rarely, mef(A). Among the one-third of isolates highly resistant to kanamycin and streptomycin, most harbored aphA3 and aad-6 genes. PMID:15793162

  3. Streptococcus tigurinus, a Novel Member of the Streptococcus mitis Group, Causes Invasive Infections

    PubMed Central

    Mueller, Nicolas J.; Tarr, Philip E.; Eich, Gerhard; Schulthess, Bettina; Bahlmann, Anna S.; Keller, Peter M.; Bloemberg, Guido V.

    2012-01-01

    We recently described the novel species Streptococcus tigurinus sp. nov. belonging to the Streptococcus mitis group. The type strain AZ_3aT of S. tigurinus was originally isolated from a patient with infective endocarditis. According to its phenotypic and molecular characteristics, S. tigurinus is most closely related to Streptococcus mitis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae, Streptococcus oralis, and Streptococcus infantis. Accurate identification of S. tigurinus is facilitated by 16S rRNA gene analysis. We retrospectively analyzed our 16S rRNA gene molecular database, which contains sequences of all clinical samples obtained in our institute since 2003. We detected 17 16S rRNA gene sequences which were assigned to S. tigurinus, including sequences from the 3 S. tigurinus strains described previously. S. tigurinus originated from normally sterile body sites, such as blood, cerebrospinal fluid, or heart valves, of 14 patients and was initially detected by culture or broad-range 16S rRNA gene PCR, followed by sequencing. The 14 patients had serious invasive infections, i.e., infective endocarditis (n = 6), spondylodiscitis (n = 3), bacteremia (n = 2), meningitis (n = 1), prosthetic joint infection (n = 1), and thoracic empyema (n = 1). To evaluate the presence of Streptococcus tigurinus in the endogenous oral microbial flora, we screened saliva specimens of 31 volunteers. After selective growth, alpha-hemolytic growing colonies were analyzed by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and subsequent molecular methods. S. tigurinus was not identified among 608 strains analyzed. These data indicate that S. tigurinus is not widely distributed in the oral cavity. In conclusion, S. tigurinus is a novel agent of invasive infections, particularly infective endocarditis. PMID:22760039

  4. Streptococcus moroccensis sp. nov. and Streptococcus rifensis sp. nov., isolated from raw camel milk.

    PubMed

    Kadri, Zaina; Amar, Mohamed; Ouadghiri, Mouna; Cnockaert, Margo; Aerts, Maarten; El Farricha, Omar; Vandamme, Peter

    2014-07-01

    Two catalase- and oxidase-negative Streptococcus-like strains, LMG 27682(T) and LMG 27684(T), were isolated from raw camel milk in Morocco. Comparative 16S rRNA gene sequencing assigned these bacteria to the genus Streptococcus with Streptococcus rupicaprae 2777-2-07(T) as their closest phylogenetic neighbour (95.9% and 95.7% similarity, respectively). 16S rRNA gene sequence similarity between the two strains was 96.7%. Although strains LMG 27682(T) and LMG 27684(T) shared a DNA-DNA hybridization value that corresponded to the threshold level for species delineation (68%), the two strains could be distinguished by multiple biochemical tests, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes and by their MALDI-TOF MS profiles. On the basis of these considerable phenotypic and genotypic differences, we propose to classify both strains as novel species of the genus Streptococcus, for which the names Streptococcus moroccensis sp. nov. (type strain, LMG 27682(T)  = CCMM B831(T)) and Streptococcus rifensis sp. nov. (type strain, LMG 27684(T)  = CCMM B833(T)) are proposed.

  5. Streptococcus loxodontisalivarius sp. nov. and Streptococcus saliviloxodontae sp. nov., isolated from oral cavities of elephants.

    PubMed

    Saito, Masanori; Shinozaki-Kuwahara, Noriko; Hirasawa, Masatomo; Takada, Kazuko

    2014-09-01

    Four Gram-stain-positive, catalase-negative, coccoid-shaped organisms were isolated from elephant oral cavities. The isolates were tentatively identified as streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequencing studies confirmed the organisms to be members of the genus Streptococcus. Two isolates (NUM 6304(T) and NUM 6312) were related most closely to Streptococcus salivarius with 96.8 % and 93.1 % similarity based on the 16S rRNA gene and the RNA polymerase β subunit encoding gene (rpoB), respectively, and to Streptococcus vestibularis with 83.7 % similarity based on the 60 kDa heat-shock protein gene (groEL). The other two isolates (NUM 6306(T) and NUM 6318) were related most closely to S. vestibularis with 97.0 % and 82.9 % similarity based on the 16S rRNA and groEL genes, respectively, and to S. salivarius with 93.5 % similarity based on the rpoB gene. Based on phylogenetic and phenotypic evidence, these isolates are suggested to represent novel species of the genus Streptococcus, for which the names Streptococcus loxodontisalivarius sp. nov. (type strain NUM 6304(T) = JCM 19287(T) = DSM 27382(T)) and Streptococcus saliviloxodontae sp. nov. (type strain NUM 6306(T) = JCM 19288(T) = DSM 27513(T)) are proposed.

  6. 9230 FECAL ENTEROCOCCUS/STREPTOCOCCUS GROUPS

    EPA Science Inventory

    In 1903 the genus name Enterococcus was proposed for gram-positive, catalase-negative, coccoid-shaped bacterial of intestinal origin. Several years later, it was suggested that the genus name be changed to Streptococcus because of the organisms' ability to form chains of coccoid...

  7. A lingual abscess caused by Streptococcus intermedius.

    PubMed

    Harrington, Amanda T; Hsia, Jennifer C; Mendez, Eduardo; Clarridge, Jill E

    2012-04-01

    Lingual abscesses are rare. We describe a case in a healthy female with no recent history of trauma. The organism recovered by culture of drainage material collected prior to antibiotic treatment was Streptococcus intermedius, an organism recognized as flora of the oropharynx and associated with abscess formation. The isolate was resistant to clindamycin, which was the antibiotic therapy that the patient received.

  8. 9230 FECAL ENTEROCOCCUS/STREPTOCOCCUS GROUPS

    EPA Science Inventory

    In 1903 the genus name Enterococcus was proposed for gram-positive, catalase-negative, coccoid-shaped bacterial of intestinal origin. Several years later, it was suggested that the genus name be changed to Streptococcus because of the organisms' ability to form chains of coccoid...

  9. Nontypeable Streptococcus pneumoniae as an Otopathogen

    PubMed Central

    Xu, Qingfu; Kaur, Ravinder; Casey, Janet R.; Sabharwal, Vishakha; Pelton, Stephen; Pichichero, Michael E.

    2014-01-01

    Among 34 Spn sequential isolates from middle ear fluid we found a case of a nontypeable Streptococcus pneumoniae (NT-Spn) in a child with AOM. The strain was pneumolysin PCR positive and capsule gene PCR negative. Virulence of the NT-Spn was confirmed in a chinchilla model of AOM. PMID:21251566

  10. Streptococcus-Zebrafish Model of Bacterial Pathogenesis

    PubMed Central

    Neely, Melody N.; Pfeifer, John D.; Caparon, Michael

    2002-01-01

    Due to its small size, rapid generation time, powerful genetic systems, and genomic resources, the zebrafish has emerged as an important model of vertebrate development and human disease. Its well-developed adaptive and innate cellular immune systems make the zebrafish an ideal model for the study of infectious diseases. With a natural and important pathogen of fish, Streptococcus iniae, we have established a streptococcus- zebrafish model of bacterial pathogenesis. Following injection into the dorsal muscle, zebrafish developed a lethal infection, with a 50% lethal dose of 103 CFU, and died within 2 to 3 days. The pathogenesis of infection resembled that of S. iniae in farmed fish populations and that of several important human streptococcal diseases and was characterized by an initial focal necrotic lesion that rapidly progressed to invasion of the pathogen into all major organ systems, including the brain. Zebrafish were also susceptible to infection by the human pathogen Streptococcus pyogenes. However, disease was characterized by a marked absence of inflammation, large numbers of extracellular streptococci in the dorsal muscle, and extensive myonecrosis that occurred far in advance of any systemic invasion. The genetic systems available for streptococci, including a novel method of mutagenesis which targets genes whose products are exported, were used to identify several mutants attenuated for virulence in zebrafish. This combination of a genetically amenable pathogen with a well-defined vertebrate host makes the streptococcus-zebrafish model of bacterial pathogenesis a powerful model for analysis of infectious disease. PMID:12065534

  11. Streptococcus equi subsp. zooepidemicus meningitis in Peru.

    PubMed

    Mori, Nicanor; Guevara, Jose M; Tilley, Drake H; Briceno, Jesus A; Zunt, Joseph R; Montano, Silvia M

    2013-02-01

    A 59-year-old man with a history of fever, unsteadiness, hemiparesis, motor aphasia and consciousness disturbance was hospitalized for Streptococcus equi subsp. zooepidemicus meningitis. He denied contact with farm animals, but had a practice of consuming unpasteurized goats' cheese from an uncertain source.

  12. Streptococcus equi subsp. zooepidemicus meningitis in Peru

    PubMed Central

    Guevara, Jose M.; Tilley, Drake H.; Briceno, Jesus A.; Zunt, Joseph R.; Montano, Silvia M.

    2013-01-01

    A 59-year-old man with a history of fever, unsteadiness, hemiparesis, motor aphasia and consciousness disturbance was hospitalized for Streptococcus equi subsp. zooepidemicus meningitis. He denied contact with farm animals, but had a practice of consuming unpasteurized goats’ cheese from an uncertain source. PMID:23105024

  13. Revisitingmolecular serotyping of Streptococcus pneumoniae

    PubMed Central

    2015-01-01

    Background Ninety-two Streptococcus pneumoniae serotypes have been described so far, but the pneumococcal conjugate vaccine introduced in the Brazilian basic vaccination schedule in 2010 covers only the ten most prevalent in the country. Pneumococcal serotype-shifting after massive immunization is a major concern and monitoring this phenomenon requires efficient and accessible serotyping methods. Pneumococcal serotyping based on antisera produced in animals is laborious and restricted to a few reference laboratories. Alternatively, molecular serotyping methods assess polymorphisms in the cps gene cluster, which encodes key enzymes for capsular polysaccharides synthesis in pneumococci. In one such approach, cps-RFLP, the PCR amplified cps loci are digested with an endonuclease, generating serotype-specific fingerprints on agarose gel electrophoresis. Methods In this work, in silico and in vitro approaches were combined to demonstrate that XhoII is the most discriminating endonuclease for cps-RFLP, and to build a database of serotype-specific fingerprints that accommodates the genetic diversity within the cps locus of 92 known pneumococci serotypes. Results The expected specificity of cps-RFLP using XhoII was 76% for serotyping and 100% for serogrouping. The database of cps-RFLP fingerprints was integrated to Molecular Serotyping Tool (MST), a previously published web-based software for molecular serotyping. In addition, 43 isolates representing 29 serotypes prevalent in the state of Minas Gerais, Brazil, from 2007 to 2013, were examined in vitro; 11 serotypes (nine serogroups) matched the respective in silico patterns calculated for reference strains. The remaining experimental patterns, despite their resemblance to their expected in silico patterns, did not reach the threshold of similarity score to be considered a match and were then added to the database. Conclusion The cps-RFLP method with XhoII outperformed the antisera-based and other molecular serotyping

  14. Molecular and antimicrobial susceptibility profiling of atypical Streptococcus species from porcine clinical specimens.

    PubMed

    Moreno, Luisa Z; Matajira, Carlos E C; Gomes, Vasco T M; Silva, Ana Paula S; Mesquita, Renan E; Christ, Ana Paula G; Sato, Maria Inês Z; Moreno, Andrea M

    2016-10-01

    The Streptococcus species present broad phenotypic variation, making identification difficult using only traditional microbiological methods. Even though Streptococcus suis is the most important species for the worldwide swine industry, other Streptococcus species appear to be able to cause disease in swine and could represent a higher underestimated risk for porcine health. The aim of this study was to identify Streptococcus-like isolates by MALDI-TOF MS and 16S rRNA sequencing and further molecular and antibiotic susceptibility characterization of the atypical Streptococcus species capable of causing disease in swine. Fifty presumptive Streptococcus isolates from diseased pigs isolated from different Brazilian States between 2002 and 2014 were evaluated. Among the studied isolates, 26% were identified as Streptococcus hyovaginalis, 24% as Streptococcus plurianimalium, 12% as Streptococcus alactolyticus, 10% as Streptococcus hyointestinalis, and the remaining isolates belonged to Streptococcus henryi (6%), Streptococcus thoraltensis (6%), Streptococcus gallolyticus (6%), Streptococcus gallinaceus (4%), Streptococcus sanguinis (4%), and Streptococcus mitis (2%). The Streptococcus isolates were successfully identified by spectral cluster analysis and 16S rRNA sequencing with 96% of concordance between the techniques. The SE-AFLP analysis also supported Streptococcus species distinction and enabled further observation of higher genetic heterogeneity intra-species. The identified Streptococcus species presented variable MIC values to β-lactams, enrofloxacin and florfenicol, and high resistance rates to tetracyclines and macrolides, which appear to be directly related to the industry's antimicrobial usage and resistance selection. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Description of Streptococcus pneumoniae Infections in Burn Patients

    DTIC Science & Technology

    2010-01-01

    Description of Streptococcus pneumoniae infections in burn patients§ Jessie S. Glasser a, Michael L. Landruma,b,c, Kevin K. Chung a,d, Duane R...history: Accepted 10 July 2009 Keywords: Burn Streptococcus pneumoniae Pneumococcus Pneumococcal a b s t r a c t Background: Longer survival in burn...Staphylococcus aureus. Although Streptococcus pneumoniae infections are common in the community and can cause nosocomial infections, the incidence and

  16. Developing oral probiotics from Streptococcus salivarius.

    PubMed

    Wescombe, Philip A; Hale, John D F; Heng, Nicholas C K; Tagg, John R

    2012-12-01

    Considerable human illness can be linked to the development of oral microbiota disequilibria. The predominant oral cavity commensal, Streptococcus salivarius has emerged as an important source of safe and efficacious probiotics, capable of fostering more balanced, health-associated oral microbiota. Strain K12, the prototype S. salivarius probiotic, originally introduced to counter Streptococcus pyogenes infections, now has an expanded repertoire of health-promoting applications. K12 and several more recently proposed S. salivarius probiotics are now being applied to control diverse bacterial consortia infections including otitis media, halitosis and dental caries. Other potential applications include upregulation of immunological defenses against respiratory viral infections and treatment of oral candidosis. An overview of the key steps required for probiotic development is also presented.

  17. PYRUVATE FERMENTATION BY STREPTOCOCCUS FAECALIS1

    PubMed Central

    Deibel, R. H.; Niven, C. F.

    1964-01-01

    Deibel, R. H. (American Meat Institute Foundation, Chicago, Ill.), and C. F. Niven, Jr. Pyruvate fermentation by Streptococcus faecalis. J. Bacteriol. 88:4–10. 1964.—Streptococcus faecalis, as opposed to S. faecium, utilizes pyruvate as an energy source for growth. The fermentation is adaptive, as demonstrated by growth experiments in a casein-hydrolysate medium and the fermentation of pyruvate by cell suspensions. The principal products of pyruvate catabolism were acetoin, CO2, and lactic, acetic, and formic acids, although carbon recoveries were low due to the formation of slime. End-product analyses suggested that both the phosphoroclastic and dismutation systems were active in pyruvate breakdown. Studies with cell-free extracts indicated a thiamine diphosphate requirement for active pyruvate catabolism. The involvement of lipoic acid in the phosphoroclastic system was investigated, and, although inconclusive results were obtained, no association of this cofactor with phosphoroclastic activity could be made. PMID:14197905

  18. [Thousand faces of Streptococcus pneumonia (pneumococcus) infections].

    PubMed

    Szabó, Bálint Gergely; Lénárt, Katalin Szidónia; Kádár, Béla; Gombos, Andrea; Dezsényi, Balázs; Szanka, Judit; Bobek, Ilona; Prinz, Gyula

    2015-11-01

    Incidence and mortality rates of infections caused by Streptococcus pneumoniae (pneumococcus) are high worldwide and in Hungary among paediatric as well as adult populations. Pneumococci account for 35-40% of community acquired adult pneumonias requiring hospitalization, while 25-30% of Streptococcus pneumoniae pneumonias are accompanied by bacteraemia. 5-7% of all infections are fatal but this rate is exponentially higher in high risk patients and elderly people. Mortality could reach 20% among patients with severe invasive pneumococcal infections. Complications may develop despite administration of adequate antibiotics. The authors summarize the epidemiology of pneumococcal infections, pathogenesis of non-invasive and invasive disease and present basic clinical aspects through demonstration of four cases. Early risk stratification, sampling of hemocultures, administration of antibiotics and wider application of active immunization could reduce the mortality of invasive disease. Anti-pneumococcal vaccination is advisable for adults of ≥50 years and high risk patients of ≥18 years who are susceptible to pneumococcal disease.

  19. Dual Functions of Streptococcus salivarius Urease

    PubMed Central

    Chen, Yi-Ywan M.; Weaver, Cheryl A.; Burne, Robert A.

    2000-01-01

    A urease-deficient derivative of Streptococcus salivarius 57.I was constructed by allelic exchange at the ureC locus. The wild-type strain was protected against acid killing through hydrolysis of physiologically relevant concentrations of urea, whereas the mutant was not. Also, S. salivarius could use urea as a source of nitrogen for growth exclusively through a urease-dependent pathway. PMID:10913107

  20. Genomics, evolution, and molecular epidemiology of the Streptococcus bovis/Streptococcus equinus complex (SBSEC).

    PubMed

    Jans, Christoph; Meile, Leo; Lacroix, Christophe; Stevens, Marc J A

    2015-07-01

    The Streptococcus bovis/Streptococcus equinus complex (SBSEC) is a group of human and animal derived streptococci that are commensals (rumen and gastrointestinal tract), opportunistic pathogens or food fermentation associates. The classification of SBSEC has undergone massive changes and currently comprises 7 (sub)species grouped into four branches based on sequences identities: the Streptococcus gallolyticus, the Streptococcus equinus, the Streptococcus infantarius and the Streptococcus alactolyticus branch. In animals, SBSEC are causative agents for ruminal acidosis, potentially laminitis and infective endocarditis (IE). In humans, a strong association was established between bacteraemia, IE and colorectal cancer. Especially the SBSEC-species S. gallolyticus subsp. gallolyticus is an emerging pathogen for IE and prosthetic joint infections. S. gallolyticus subsp. pasteurianus and the S. infantarius branch are further associated with biliary and urinary tract infections. Knowledge on pathogenic mechanisms is so far limited to colonization factors such as pili and biofilm formation. Certain strain variants of S. gallolyticus subsp. macedonicus and S. infantarius subsp. infantarius are associated with traditional dairy and plant-based food fermentations and display traits suggesting safety. However, due to their close relationship to virulent strains, their use in food fermentation has to be critically assessed. Additionally, implementing accurate and up-to-date taxonomy is critical to enable appropriate treatment of patients and risk assessment of species and strains via recently developed multilocus sequence typing schemes to enable comparative global epidemiology. Comparative genomics revealed that SBSEC strains harbour genomics islands (GI) that seem acquired from other streptococci by horizontal gene transfer. In case of virulent strains these GI frequently encode putative virulence factors, in strains from food fermentation the GI encode functions that are

  1. Cloning and expression of hyaluronate lyase genes of Streptococcus intermedius and Streptococcus constellatus subsp. constellatus(1).

    PubMed

    Takao, Ayuko

    2003-02-14

    Hyaluronate lyase (HAase) genes of Streptococcus intermedius and Streptococcus constellatus subsp. constellatus were isolated. In S. constellatus subsp. constellatus, the deduced amino acid sequence of HAase was most similar to that of S. intermedius (68%), whereas the enzyme of S. intermedius was most similar to that of S. pneumoniae (72%). Upstream of the HAase gene on the opposite strands, an open reading frame of a putative glutathione peroxidase started in S. intermedius, and this arrangement was similar to that in S. pneumoniae but unlike that in S. constellatus subsp. constellatus. Cell lysates of Escherichia coli carrying each streptococcal gene showed HAase activity, demonstrating that each cloned gene actually coded for HAase.

  2. Recombination between Streptococcus suis ICESsu32457 and Streptococcus agalactiae ICESa2603 yields a hybrid ICE transferable to Streptococcus pyogenes.

    PubMed

    Marini, Emanuela; Palmieri, Claudio; Magi, Gloria; Facinelli, Bruna

    2015-07-09

    Integrative conjugative elements (ICEs) are mobile genetic elements that reside in the chromosome but retain the ability to undergo excision and to transfer by conjugation. Genes involved in drug resistance, virulence, or niche adaptation are often found among backbone genes as cargo DNA. We recently characterized in Streptococcus suis an ICE (ICESsu32457) carrying resistance genes [tet(O/W/32/O), tet(40), erm(B), aphA, and aadE] in the 15K unstable genetic element, which is flanked by two ∼1.3kb direct repeats. Remarkably, ∼1.3-kb sequences are conserved in ICESa2603 of Streptococcus agalactiae 2603V/R, which carry heavy metal resistance genes cadC/cadA and mer. In matings between S. suis 32457 (donor) and S. agalactiae 2603V/R (recipient), transconjugants were obtained. PCR experiments, PFGE, and sequence analysis of transconjugants demonstrated a tandem array between ICESsu32457 and ICESa2603. Matings between tandem array-containing S. agalactiae 2603V/R (donor) and Streptococcus pyogenes RF12 (recipient) yielded a single transconjugant containing a hybrid ICE, here named ICESa2603/ICESsu32457. The hybrid formed by recombination of the left ∼1.3-kb sequence of ICESsu32457 and the ∼1.3-kb sequence of ICESa2603. Interestingly, the hybrid ICE was transferable between S. pyogenes strains, thus demonstrating that it behaves as a conventional ICE. These findings suggest that both tandem arrays and hybrid ICEs may contribute to the evolution of antibiotic resistance in streptococci, creating novel mobile elements capable of disseminating new combinations of antibiotic resistance genes.

  3. Human Streptococcus agalactiae isolate in Nile tilapia (Oreochromis niloticus)

    USDA-ARS?s Scientific Manuscript database

    Streptococcus agalactiae, the Lancefield group B Streptococcus (GBS), long recognized as a mammalian pathogen, is an emerging pathogen to fish. We show that a GBS serotype Ia, multilocus sequence type ST-7 isolate from a human neonatal meningitis clinical case causes disease signs and mortality in N...

  4. Diversity of human small intestinal Streptococcus and Veillonella populations.

    PubMed

    van den Bogert, Bartholomeus; Erkus, Oylum; Boekhorst, Jos; de Goffau, Marcus; Smid, Eddy J; Zoetendal, Erwin G; Kleerebezem, Michiel

    2013-08-01

    Molecular and cultivation approaches were employed to study the phylogenetic richness and temporal dynamics of Streptococcus and Veillonella populations in the small intestine. Microbial profiling of human small intestinal samples collected from four ileostomy subjects at four time points displayed abundant populations of Streptococcus spp. most affiliated with S. salivarius, S. thermophilus, and S. parasanguinis, as well as Veillonella spp. affiliated with V. atypica, V. parvula, V. dispar, and V. rogosae. Relative abundances varied per subject and time of sampling. Streptococcus and Veillonella isolates were cultured using selective media from ileostoma effluent samples collected at two time points from a single subject. The richness of the Streptococcus and Veillonella isolates was assessed at species and strain level by 16S rRNA gene sequencing and genetic fingerprinting, respectively. A total of 160 Streptococcus and 37 Veillonella isolates were obtained. Genetic fingerprinting differentiated seven Streptococcus lineages from ileostoma effluent, illustrating the strain richness within this ecosystem. The Veillonella isolates were represented by a single phylotype. Our study demonstrated that the small intestinal Streptococcus populations displayed considerable changes over time at the genetic lineage level because only representative strains of a single Streptococcus lineage could be cultivated from ileostoma effluent at both time points.

  5. Complete Genome Sequence of Streptococcus sp. Strain NPS 308

    PubMed Central

    Ogura, Yoshitoshi; Sato, Keiko; Imamura, Keigo; Hoshino, Tomonori; Nishiguchi, Miyuki; Hasuwa, Tomoyuki; Moriuchi, Hiroyuki; Hayashi, Tetsuya; Fujiwara, Taku

    2016-01-01

    Streptococcus sp. strain NPS 308, isolated from an 8-year-old girl diagnosed with infective endocarditis, likely presents a novel species of Streptococcus. Here, we present a complete genome sequence of this species, which will contribute to better understanding of the pathogenesis of infective endocarditis. PMID:28007849

  6. 21 CFR 866.3740 - Streptococcus spp. serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Streptococcus spp. serological reagents. 866.3740 Section 866.3740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3740 Streptococcus...

  7. 21 CFR 866.3740 - Streptococcus spp. serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Streptococcus spp. serological reagents. 866.3740 Section 866.3740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3740 Streptococcus...

  8. 21 CFR 866.3740 - Streptococcus spp. serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Streptococcus spp. serological reagents. 866.3740 Section 866.3740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3740 Streptococcus...

  9. Human Streptococcus agalactiae isolate in Nile tilapia (Oreochromis niloticus).

    PubMed

    Evans, Joyce J; Klesius, Phillip H; Pasnik, David J; Bohnsack, John F

    2009-05-01

    Streptococcus agalactiae, the Lancefield group B streptococcus (GBS) long recognized as a mammalian pathogen, is an emerging concern with regard to fish. We show that a GBS serotype Ia multilocus sequence type ST-7 isolate from a clinical case of human neonatal meningitis caused disease and death in Nile tilapia (Oreochromis niloticus).

  10. Endocarditis caused by Streptococcus canis: an emerging zoonosis?

    PubMed

    Lacave, Guillaume; Coutard, Aymeric; Troché, Gilles; Augusto, Sandrine; Pons, Stéphanie; Zuber, Benjamin; Laurent, Virginie; Amara, Marlène; Couzon, Brigitte; Bédos, Jean-Pierre; Pangon, Béatrice; Grimaldi, David

    2016-02-01

    We report a human case of infective endocarditis caused by Streptococcus canis. Identification was carried out from positive blood culture using mass spectrometry and SodA gene sequencing. S. canis related zoonotic invasive infections may have been previously underdiagnosed due to inadequate identification of group G Streptococcus species.

  11. Complete genome sequence of Streptococcus thermophilus strain ND03.

    PubMed

    Sun, Zhihong; Chen, Xia; Wang, Jicheng; Zhao, Wenjing; Shao, Yuyu; Wu, Lan; Zhou, Zhemin; Sun, Tiansong; Wang, Lei; Meng, He; Zhang, Heping; Chen, Wei

    2011-02-01

    Streptococcus thermophilus strain ND03 is a Chinese commercial dairy starter used for the manufacture of yogurt. It was isolated from naturally fermented yak milk in Qinghai, China. We present here the complete genome sequence of ND03 and compare it to three other published genomes of Streptococcus thermophilus strains.

  12. 21 CFR 866.3740 - Streptococcus spp. serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Streptococcus spp. serological reagents. 866.3740 Section 866.3740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3740 Streptococcus...

  13. Influence of pH on inhibition of Streptococcus mutans by Streptococcus oligofermentans.

    PubMed

    Liu, Ying; Chu, Lei; Wu, Fei; Guo, Lili; Li, Mengci; Wang, Yinghui; Wu, Ligeng

    2014-02-01

    Streptococcus oligofermentans is a novel strain of oral streptococcus that can specifically inhibit the growth of Streptococcus mutans. The aims of this study were to assess the growth of S. oligofermentans and the ability of S. oligofermentans to inhibit growth of Streptococcus mutans at different pH values. Growth inhibition was investigated in vitro using an interspecies competition assay. The 4-aminoantipyine method was used to measure the initial production rate and the total yield of hydrogen peroxide in S. oligofermentans. S. oligofermentans grew best at pH 7.0 and showed the most pronounced inhibitory effect when it was inoculated earlier than S. mutans. In terms of the total yield and the initial production rate of hydrogen peroxide by S. oligofermentans, the effects of the different culture pH values were as follows: pH 7.0 > 6.5 > 6.0 > 7.5 > 5.5 = 8.0 (i.e. there was no significant difference between pH 5.5 and pH 8.0). Environmental pH and the sequence of inoculation significantly affected the ability of S. oligofermentans to inhibit the growth of S. mutans. The degree of inhibition may be attributed to the amount of hydrogen peroxide produced.

  14. Spring forward with improved Nile tilapia Oreochromis niloticus resistant to Streptococcus iniae and Streptococcus agalactiae IB

    USDA-ARS?s Scientific Manuscript database

    Tilapia aquaculture worldwide is valued around US $ 7 billion. Tilapia are an important source of protein for domestic (top 5 most consumed seafoods) and global food security. Two gram postitive bacteria, Streptococcus iniae and S. agalactiae, are responsible for billion dollar losses annually. Gen...

  15. Delineation of Streptococcus dysgalactiae, Its Subspecies, and Its Clinical and Phylogenetic Relationship to Streptococcus pyogenes

    PubMed Central

    Jensen, Anders

    2012-01-01

    The taxonomic status and structure of Streptococcus dysgalactiae have been the object of much confusion. Bacteria belonging to this species are usually referred to as Lancefield group C or group G streptococci in clinical settings in spite of the fact that these terms lack precision and prevent recognition of the exact clinical relevance of these bacteria. The purpose of this study was to develop an improved basis for delineation and identification of the individual species of the pyogenic group of streptococci in the clinical microbiology laboratory, with a special focus on S. dysgalactiae. We critically reexamined the genetic relationships of the species S. dysgalactiae, Streptococcus pyogenes, Streptococcus canis, and Streptococcus equi, which may share Lancefield group antigens, by phylogenetic reconstruction based on multilocus sequence analysis (MLSA) and 16S rRNA gene sequences and by emm typing combined with phenotypic characterization. Analysis of concatenated sequences of seven genes previously used for examination of viridans streptococci distinguished robust and coherent clusters. S. dysgalactiae consists of two separate clusters consistent with the two recognized subspecies dysgalactiae and equisimilis. Both taxa share alleles with S. pyogenes in several housekeeping genes, which invalidates identification based on single-locus sequencing. S. dysgalactiae, S. canis, and S. pyogenes constitute a closely related branch within the genus Streptococcus indicative of recent descent from a common ancestor, while S. equi is highly divergent from other species of the pyogenic group streptococci. The results provide an improved basis for identification of clinically important pyogenic group streptococci and explain the overlapping spectrum of infections caused by the species associated with humans. PMID:22075580

  16. Group B Streptococcus Induces Trophoblast Death

    PubMed Central

    Kaplan, Amber; Chung, Kathy; Kocak, Hande; Bertolotto, Cristina; Uh, Andy; Hobel, Calvin J; Simmons, Charles F; Doran, Kelly; Liu, George; Equils, Ozlem

    2008-01-01

    Group B streptococcus (GBS) is one of the leading causes of neonatal infection; however the molecular mechanisms involved are not clearly known. Here we used high and low hemolytic GBS isolates and mutant GBS that lacks β-hemolysin expression and showed that GBS infection or exposure to GBS-hemolysin extract induces primary human trophoblast, placental fibroblast and JEG3 trophoblast cell line death, and that GBS-induced trophoblast death was β-hemolysin dependent. The fibroblasts and trophoblasts provide an innate immune barrier between fetal and maternal circulation in the placenta. These data suggest that GBS may disrupt this barrier to invade fetal circulation. PMID:18599257

  17. Lactational mastitis caused by Streptococcus lactarius.

    PubMed

    Tena, Daniel; Fernández, Cristina; López-Garrido, Beatriz; Pérez-Balsalobre, Mercedes; Losa, Cristina; Medina-Pascual, María José; Sáez-Nieto, Juan Antonio

    2016-08-01

    Human infections caused by Streptococcus lactarius have not been previously reported. In the present report, we describe a lactational mastitis caused by this organism. The infection occurred in a 28-year-old breast-feeding female, with a 10-days history of moderate pain on the right breast. The patient was cured after antibiotic treatment with levofloxacin for 21 days. Our case shows that S. lactarius should be considered as a cause of lactational mastitis. The introduction of molecular microbiology techniques can be extremely useful for knowing the implication of streptococci in lactational mastitis.

  18. Update on Streptococcus equi subsp equi infections.

    PubMed

    Mallicote, Martha

    2015-04-01

    There are few diseases that ignite as much fervor among horse owners as strangles. Streptococcus equi subsp equi (strangles) infections frequently require the treating veterinarian to manage not only the clinical cases but also the biosecurity and provision of information to all involved parties. Although the disease is typically characterized by low mortality and high morbidity, restrictions of horse movement that result from appropriate quarantine procedures often frustrate the involved parties. The aims of this article are to provide clinically relevant information for diagnosis, treatment, and biosecurity management of strangles infection.

  19. Primary ventriculitis caused by Streptococcus intermedius.

    PubMed

    Vajramani, G V; Akrawi, H; Jones, G; Sparrow, O C E

    2007-06-01

    Streptococcus intermedius is increasingly being recognised as an aetiological agent in central nervous system infections. Primary ventriculitis caused by this organism has not been reported so far. We present a case of primary ventriculitis, which resulted in adhesions and multiloculated hydrocephalus, necessitating numerous surgical procedures to control it. No predisposing factor(s) could be identified. Although the organism could not be cultured from CSF, as he was already on antibiotic treatment, it could, however, be identified by 16S rDNA polymerase chain reaction on the CSF sample. It appears important to recognise this condition and to treat it aggressively to prevent complications such as adhesions and multiloculated hydrocephalus.

  20. Streptococcus mutans, Caries and Simulation Models

    PubMed Central

    Forssten, Sofia D.; Björklund, Marika; Ouwehand, Arthur C.

    2010-01-01

    Dental caries and dental plaque are among the most common diseases worldwide, and are caused by a mixture of microorganisms and food debris. Specific types of acid-producing bacteria, especially Streptococcus mutans, colonize the dental surface and cause damage to the hard tooth structure in the presence of fermentable carbohydrates e.g., sucrose and fructose. This paper reviews the link between S. mutans and caries, as well as different simulation models that are available for studying caries. These models offer a valuable approach to study cariogenicity of different substrates as well as colonization of S. mutans. PMID:22254021

  1. [The effect of fluoride on adhesion of Streptococcus mutans and Streptococcus sanguis on the dental pure titanium surface].

    PubMed

    Wang, Jue; Qiao, Guang-yan; Shen, Qing-ping; Gu, Kai-kai

    2015-04-01

    This study was to investigate the effect of fluoride on adhesion of Streptococcus mutans and Streptococcus sanguis on the dental pure titanium surface. The adhesion of Streptococcus mutans and Streptococcus sanguis on the dental pure titanium surface were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after soaked in artificial saliva containing different concentrations of sodium fluoride for 24 h. Then the surface roughness and surface morphology of the pure titanium were analyzed by atomic force microscope after bacterial adhesion experiments. The data was statistically analyzed by analysis of variance(ANOVA) with SPSS11.0 software package. After soaked in artificial saliva containing different concentrations of sodium fluoride for 24 h, the sequence of OD values showed the adhesion of Streptococcus mutans and Streptococcus sanguis on dental pure titanium surface was 0 g/L < 0.5 g/L < 1.0g/L < 2.0 g/L (P<0.05). In addition, the sequence of Ra values showed the surface roughness of pure titanium after bacterial adhesion experiments was 0 g/L < 0.5 g/L < 1.0g/L < 2.0 g/L (P<0.05). And the surface morphology of pure titanium was consistent with the changes of OD value and Ra value. The results of adhesion of Streptococcus mutans and Streptococcus sanguis, surface roughness and surface morphology reveal that fluoride aggravates the corrosion of pure titanium, increases the surface roughness, and thus promots the adhesion of Streptococcus mutans and Streptococcus sanguis on the titanium surface.

  2. Diverse virulent pneumophages infect Streptococcus mitis.

    PubMed

    Ouennane, Siham; Leprohon, Philippe; Moineau, Sylvain

    2015-01-01

    Streptococcus mitis has emerged as one of the leading causes of bacterial endocarditis and is related to Streptococcus pneumoniae. Antibiotic resistance has also increased among strains of S. mitis and S. pneumoniae. Phages are being reinvestigated as alternatives to antibiotics for managing infections. In this study, the two virulent phages Cp-1 (Podoviridae) and Dp-1 (Siphoviridae), previously isolated from S. pneumoniae, were found to also infect S. mitis. Microbiological assays showed that both pneumophages could not only replicate in S. mitis but also produced more visible plaques on this host. However, the burst size and phage adsorption data were lower in S. mitis as compared to S. pneumoniae. A comparison of the genomes of each phage grown on both hosts produced identical nucleotide sequences, confirming that the same phages infect both bacterial species. We also discovered that the genomic sequence of podophage Cp-1 of the Félix d'Hérelle collection is different than the previously reported sequence and thus renamed SOCP.

  3. Streptococcus mutans-induced nephritis in rabbits.

    PubMed Central

    Albini, B.; Nisengard, R. J.; Glurich, I.; Neiders, M. E.; Stinson, M. W.

    1985-01-01

    Intravenous administration of disrupted Streptococcus mutans into rabbits over 23-76 weeks led to severe nephritis involving glomeruli, tubules, and interstitium. Light-microscopic observation of glomeruli documented diffuse endocapillary proliferative glomerulonephritis accompanied often (65%) by epithelial crescents. Electron-microscopic observation revealed humps in glomeruli of 70% of kidney specimens. In the glomeruli of some rabbits, extensive fibrin deposits and sclerosis were evident. Immunofluorescence showed linear, granular, often ribbonlike or patchy immune deposits encompassing, in order of decreasing frequency, C3, IgG, streptococcal antigen, IgA, and IgM. The histopathologic and immunohistologic features of the nephritis seen in rabbits given S mutans thus shows many features of Streptococcus-associated nephritides in man, in particular, the diffuse glomerular nephritis encountered in subacute bacterial endocarditis. Further, analysis of nephritis induced by administration of S mutans may have implications for the evaluation and purification of dental caries vaccines. Images Figure 8 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 9 Figure 10 Figure 11 Figure 12 PMID:3976844

  4. Group B Streptococcus and the Vaginal Microbiota.

    PubMed

    Rosen, Geoffrey H; Randis, Tara M; Desai, Purnahamsi V; Sapra, Katherine J; Ma, Bing; Gajer, Pawel; Humphrys, Michael S; Ravel, Jacques; Gelber, Shari E; Ratner, Adam J

    2017-09-15

    Streptococcus agalactiae (group B Streptococcus [GBS]) is an important neonatal pathogen and emerging cause of disease in adults. The major risk factor for neonatal disease is maternal vaginal colonization. However, little is known about the relationship between GBS and vaginal microbiota. Vaginal lavage samples from nonpregnant women were tested for GBS, and amplicon-based sequencing targeting the 16S ribosomal RNA V3-V4 region was performed. Four hundred twenty-eight of 432 samples met the high-quality read threshold. There was no relationship between GBS carriage and demographic characteristics, α-diversity, or overall vaginal microbiota community state type (CST). Within the non-Lactobacillus-dominant CST IV, GBS positive status was significantly more prevalent in CST IV-A than CST IV-B. Significant clustering by GBS status was noted on principal coordinates analysis, and 18 individual taxa were found to be significantly associated with GBS carriage by linear discriminant analysis. After adjusting for race/ethnicity, 4 taxa were positively associated with GBS, and 6 were negatively associated. Vaginal microbiota CST and α-diversity are not related to GBS status. However, specific microbial taxa are associated with colonization of this important human pathogen, highlighting a potential role for the microbiota in promotion or inhibition of GBS colonization.

  5. Immunologically reactive proteins of Streptococcus equi.

    PubMed Central

    Timoney, J F; Trachman, J

    1985-01-01

    Immunologically reactive proteins in acid extracts and culture supernatants of Streptococcus equi were recognized through a combination of chromatographic and immunologic procedures. Both high- and low-molecular-weight components of each of these protein preparations were protective for mice and were, therefore, presumed to contain a variety of hydrolytic products or fragments of the M protein of S. equi. Convalescent horse sera that exhibited strong bactericidal activity for S. equi always reacted with polypeptides in the molecular weight range of 24,000 to 29,000, whereas preinfection sera did not. Rabbit antisera to affinity-purified S. equi protein also reacted with these polypeptides, as well as with a polypeptide of about 36,000 to 37,000 molecular weight. M protein in acid extract and culture supernatant did not cross-react in immunodiffusion, but rabbit antiserum to affinity-purified M protein from an acid extract of S. equi reacted strongly with culture supernatant proteins of approximate molecular weights of 67,000, 58,000, and 43,000. We suggest, therefore, that the M protein in culture supernatant is masked by other sequences that are removed by hot acid during preparation of acid extracts. Polypeptides common to acid extracts of S. equi and Streptococcus zooepidemicus were also identified. These polypeptides had molecular weights of about 55,000 and 31,000. Images PMID:3980091

  6. STABILIZATION OF STREPTOCOCCUS FAECALIS PROTOPLASTS BY SPERMINE

    PubMed Central

    Harold, F. M.

    1964-01-01

    Harold, F. M. (National Jewish Hospital, Denver, Colo.). Stabilization of Streptococcus faecalis protoplasts by spermine. J. Bacteriol. 88:1416–1420. 1964.—Lysis of protoplasts of Streptococcus faecalis subjected to osmotic shock was prevented by the presence of 10−3m spermine and other divalent cations. Protein and nucleic acids were largely retained, but compounds of low molecular weight were discharged into the medium and the capacity for glycolysis was lost. Under these conditions, spermine was bound to the protoplasts. It could not be removed by washing with water or nonelectrolytes, but was displaced by salts, polyanions, and polycations. Removal of the spermine restored the osmotic fragility of the protoplasts, which could once again be protected from lysis by impermeant solutes. Protoplasts were also stabilized, in the absence of osmotic shock, by prolonged incubation with cations in 0.5 m sucrose. By either procedure, the protoplasts became resistant not only to osmotic lysis but also to sonic oscillation. It is concluded that the stabilization of protoplasts resulted from ionic binding of the cation to acidic sites on the external surface of the plasma membrane. This conferred upon the membrane additional mechanical strength, perhaps by the cross-linking of subunits, but did not alter its permeability to extracellular solutes. PMID:14234801

  7. Streptococcus pneumoniae necrotizing fasciitis in systemic lupus erythematosus.

    PubMed

    Sánchez, A; Robaina, R; Pérez, G; Cairoli, E

    2016-04-01

    Necrotizing fasciitis is a rapidly progressive destructive soft tissue infection with high mortality. Streptococcus pneumoniae as etiologic agent of necrotizing fasciitis is extremely unusual. The increased susceptibility to Streptococcus pneumoniae infection in patients with systemic lupus erythematosus is probably a multifactorial phenomenon. We report a case of a patient, a 36-year-old Caucasian female with 8-year history of systemic lupus erythematosus who presented a fatal Streptococcus pneumoniae necrotizing fasciitis. The role of computed tomography and the high performance of blood cultures for isolation of the causative microorganism are emphasized. Once diagnosis is suspected, empiric antibiotic treatment must be prescribed and prompt surgical exploration is mandatory.

  8. [Clustered cases of intrafamily invasive Streptococcus pyogenes infection (or group A streptococcus)].

    PubMed

    Caillet-Gossot, S; Rousset-Rouviere, C; Arlaud, K; Dubus, J-C; Bosdure, E

    2011-12-01

    Streptococcus pyogenes or group A streptococcus (GAS) is responsible for serious invasive infections with a risk of secondary infection in patients with more contact than in the general population. Regardless of clustering, few intrafamilial invasive infections have been reported despite a recent increase in the incidence of invasive GAS disease. We report the cases of two brothers, one a boy of 8.5 years with toxic shock syndrome with no bacteria identified and the second, 1 week later, his 14.5-year-old brother in hospital for sepsis due to GAS. The occurrence of a confirmed case of invasive GAS and a probable case within such a short period met the definition of clustered cases. Both brothers showed no risk factors for invasive disease and no gateway including skin was found. Antibiotic therapy was initiated in the family as recommended by the French Higher Council of Public Hygiene. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  9. Antimicrobial susceptibility of 1042 strains of Streptococcus mutans and Streptococcus sobrinus: comparison from 1985 to 1989.

    PubMed

    Liebana, J; Castillo, A; Peis, J; Baca, P; Piedrola, G

    1991-06-01

    A total of 1042 strains of Streptococcus mutans and Streptococcus sobrinus isolated between 1985 and 1989 were tested to study the evolution of their sensitivity to penicillin, amoxycillin, amoxycillin/clavulanic acid, cefuroxime, tetracycline, erythromycin, spiramycin, acetyl spiramycin, lincomycin and clindamycin. The strains were taken from stock cultures and isolated from human saliva and dental plaque. The minimal inhibitory concentration (MIC) was determined by an agar dilution method. Except for spiramycin and acetyl spiramycin, all the antibiotics inhibited 100% of the strains with concentrations less than or equal to 2 micrograms/ml. Microorganisms from both species underwent a slow progressive loss of sensitivity to all the antibiotics over a 5-year period of study, showing statistically significant results in most cases.

  10. Streptococcus henryi sp. nov. and Streptococcus caballi sp. nov., isolated from the hindgut of horses with oligofructose-induced laminitis.

    PubMed

    Milinovich, Gabriel J; Burrell, Paul C; Pollitt, Christopher C; Bouvet, Anne; Trott, Darren J

    2008-01-01

    Four Gram-positive, catalase-negative, coccoid-shaped isolates were obtained from the caecum and rectum of horses with oligofructose-induced equine laminitis. Phenotypic and phylogenetic studies were performed on these isolates. Initial biochemical profiling assigned two of the isolates to Streptococcus bovis. The other two isolates, however, could not be assigned conclusively on the basis of their biochemical profiles. Gene sequence analysis demonstrated that the four new isolates were related most closely to Streptococcus suis based on the 16S rRNA gene and to Streptococcus orisratti based on the manganese-dependent superoxide dismutase gene (sodA). Sequence divergence values from recognized Streptococcus species based on these two genes were >3 and >13%, respectively, for all four isolates. Phylogenetic and phenotypic analyses demonstrated that the four isolates formed two distinct clonal groups that are suggested to represent two novel species of the genus Streptococcus. The names proposed for these organisms are Streptococcus henryi sp. nov. (type strain 126(T) =ATCC BAA-1484(T) =DSM 19005(T)) and Streptococcus caballi sp. nov. (type strain 151(T) =ATCC BAA-1485(T) =DSM 19004(T)).

  11. [Streptococcus pyogenes infection in paediatrics: from pharyngotonsillitis to invasive infections].

    PubMed

    Espadas Maciá, David; Flor Macián, Eva María; Borrás, Rafael; Poujois Gisbert, Sandrine; Muñoz Bonet, Juan Ignacio

    2017-03-31

    Streptococcus pyogenes or Group A Streptococci (GAS) cause many infections in infancy. Changes in its epidemiology have been described in recent years, including an increase in invasive infections (iGAS). A retrospective-descriptive study was conducted on children less than 15 years old, with GAS infections, in particular iGAS, and their complications from February 2004-April 2014. A total of 2,192 positive cultures were obtained of which 92.7% were pharyngeal cultures. Twenty-nine patients were admitted to hospital: 4 with suppurative complications, 7 post-infective, 14 iGAS, and 4 probable iGAS cases. There were no differences in the frequency of GAS isolations/year. Non-invasive isolates were more frequent in winter and spring (P<.001), and 68.3% were in patients younger than 5 years. The incidence of iGAS was 2.1/100,000 children/year. There was no seasonality, and it was more frequent in younger children (P=.039). The most common diagnosis was pneumonia (6/14). Eight patients required intensive care. They were treated empirically with second or third-generation cephalosporin or with intravenous penicillin, and pneumonia required longer treatment times (P=.016). All GAS isolates were sensitive to penicillin, and 10.6% were resistant to erythromycin. The time spent in hospital was longer for iGAS than other cases (P=.028). No patients died. Pharyngotonsillitis caused by GAS is common in childhood, and its incidence is increasing in children younger than 5 years. At the moment, post-infectious complications are rare. Invasive infections are the most severe forms of presentation, and are more common in younger children. Copyright © 2017. Publicado por Elsevier España, S.L.U.

  12. Reappraisal of the taxonomy of Streptococcus suis serotypes 20, 22 and 26: Streptococcus parasuis sp. nov.

    PubMed

    Nomoto, R; Maruyama, F; Ishida, S; Tohya, M; Sekizaki, T; Osawa, Ro

    2015-02-01

    In order to clarify the taxonomic position of serotypes 20, 22 and 26 of Streptococcus suis, biochemical and molecular genetic studies were performed on isolates (SUT-7, SUT-286(T), SUT-319, SUT-328 and SUT-380) reacted with specific antisera of serotypes 20, 22 or 26 from the saliva of healthy pigs as well as reference strains of serotypes 20, 22 and 26. Comparative recN gene sequencing showed high genetic relatedness among our isolates, but marked differences from the type strain S. suis NCTC 10234(T), i.e. 74.8-75.7 % sequence similarity. The genomic relatedness between the isolates and other strains of species of the genus Streptococcus, including S. suis, was calculated using the average nucleotide identity values of whole genome sequences, which indicated that serotypes 20, 22 and 26 should be removed taxonomically from S. suis and treated as a novel genomic species. Comparative sequence analysis revealed 99.0-100 % sequence similarities for the 16S rRNA genes between the reference strains of serotypes 20, 22 and 26, and our isolates. Isolate STU-286(T) had relatively high 16S rRNA gene sequence similarity with S. suis NCTC 10234(T) (98.8 %). SUT-286(T) could be distinguished from S. suis and other closely related species of the genus Streptococcus using biochemical tests. Due to its phylogenetic and phenotypic similarities to S. suis we propose naming the novel species Streptococcus parasuis sp. nov., with SUT-286(T) ( = JCM 30273(T) = DSM 29126(T)) as the type strain.

  13. Laboratory Growth and Maintenance of Streptococcus pyogenes (The Group A Streptococcus, GAS)

    PubMed Central

    Gera, Kanika; McIver, Kevin S.

    2013-01-01

    Streptococcus pyogenes is a Gram-positive bacterium that strictly infects humans. It is the causative agent of a broad spectrum of diseases accounting for millions of infections and at least 517, 000 deaths each year worldwide (Carapetis et al., 2005). It is a nutritionally fastidious organism that ferments sugars to produce lactic acid and has strict requirements for growth. To aid in the study of this organism, this unit describes the growth and maintenance of S. pyogenes. PMID:24510893

  14. Quantification of bovine oxylipids during intramammary Streptococcus uberis infection

    USDA-ARS?s Scientific Manuscript database

    Streptococcus uberis mastitis results in severe mammary tissue damage in dairy cows due to uncontrolled inflammation. Oxylipids are potent lipid mediators that orchestrate pathogen-induced inflammatory responses, however, changes in oxylipid biosynthesis during S. uberis mastitis are unknown. Thus, ...

  15. Are Tilapia Infected with Gyrodactylus More Susceptible to Streptococcus?

    USDA-ARS?s Scientific Manuscript database

    Streptococcus iniae and Gyrodactylus niloticus are two common pathogens of cultured Nile tilapia, Oreochromis niloticus. We studied concurrent infection of tilapia by G. niloticus and S. iniae and evaluated whether parasitism in tilapia with Gyrodactylus increased susceptibility and mortality follo...

  16. Neonatal Streptococcus pneumoniae septicemia and meningitis. A case report.

    PubMed

    Di Nello, C H; Chaisilwattana, P; Fagnant, R J; Monif, G R

    1990-03-01

    Neonatal septicemia/meningitis from Streptococcus pneumoniae occurred in a 36-hour-old infant. The mother had no overt evidence of infection. This case illustrates the pathogenic potential of this common bacterium in the neonate.

  17. Comparative genomics of the dairy isolate Streptococcus macedonicus ACA-DC 198 against related members of the Streptococcus bovis/Streptococcus equinus complex.

    PubMed

    Papadimitriou, Konstantinos; Anastasiou, Rania; Mavrogonatou, Eleni; Blom, Jochen; Papandreou, Nikos C; Hamodrakas, Stavros J; Ferreira, Stéphanie; Renault, Pierre; Supply, Philip; Pot, Bruno; Tsakalidou, Effie

    2014-04-08

    Within the genus Streptococcus, only Streptococcus thermophilus is used as a starter culture in food fermentations. Streptococcus macedonicus though, which belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC), is also frequently isolated from fermented foods mainly of dairy origin. Members of the SBSEC have been implicated in human endocarditis and colon cancer. Here we compare the genome sequence of the dairy isolate S. macedonicus ACA-DC 198 to the other SBSEC genomes in order to assess in silico its potential adaptation to milk and its pathogenicity status. Despite the fact that the SBSEC species were found tightly related based on whole genome phylogeny of streptococci, two distinct patterns of evolution were identified among them. Streptococcus macedonicus, Streptococcus infantarius CJ18 and Streptococcus pasteurianus ATCC 43144 seem to have undergone reductive evolution resulting in significantly diminished genome sizes and increased percentages of potential pseudogenes when compared to Streptococcus gallolyticus subsp. gallolyticus. In addition, the three species seem to have lost genes for catabolizing complex plant carbohydrates and for detoxifying toxic substances previously linked to the ability of S. gallolyticus to survive in the rumen. Analysis of the S. macedonicus genome revealed features that could support adaptation to milk, including an extra gene cluster for lactose and galactose metabolism, a proteolytic system for casein hydrolysis, auxotrophy for several vitamins, an increased ability to resist bacteriophages and horizontal gene transfer events with the dairy Lactococcus lactis and S. thermophilus as potential donors. In addition, S. macedonicus lacks several pathogenicity-related genes found in S. gallolyticus. For example, S. macedonicus has retained only one (i.e. the pil3) of the three pilus gene clusters which may mediate the binding of S. gallolyticus to the extracellular matrix. Unexpectedly, similar findings were

  18. Comparative genomics of the dairy isolate Streptococcus macedonicus ACA-DC 198 against related members of the Streptococcus bovis/Streptococcus equinus complex

    PubMed Central

    2014-01-01

    Background Within the genus Streptococcus, only Streptococcus thermophilus is used as a starter culture in food fermentations. Streptococcus macedonicus though, which belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC), is also frequently isolated from fermented foods mainly of dairy origin. Members of the SBSEC have been implicated in human endocarditis and colon cancer. Here we compare the genome sequence of the dairy isolate S. macedonicus ACA-DC 198 to the other SBSEC genomes in order to assess in silico its potential adaptation to milk and its pathogenicity status. Results Despite the fact that the SBSEC species were found tightly related based on whole genome phylogeny of streptococci, two distinct patterns of evolution were identified among them. Streptococcus macedonicus, Streptococcus infantarius CJ18 and Streptococcus pasteurianus ATCC 43144 seem to have undergone reductive evolution resulting in significantly diminished genome sizes and increased percentages of potential pseudogenes when compared to Streptococcus gallolyticus subsp. gallolyticus. In addition, the three species seem to have lost genes for catabolizing complex plant carbohydrates and for detoxifying toxic substances previously linked to the ability of S. gallolyticus to survive in the rumen. Analysis of the S. macedonicus genome revealed features that could support adaptation to milk, including an extra gene cluster for lactose and galactose metabolism, a proteolytic system for casein hydrolysis, auxotrophy for several vitamins, an increased ability to resist bacteriophages and horizontal gene transfer events with the dairy Lactococcus lactis and S. thermophilus as potential donors. In addition, S. macedonicus lacks several pathogenicity-related genes found in S. gallolyticus. For example, S. macedonicus has retained only one (i.e. the pil3) of the three pilus gene clusters which may mediate the binding of S. gallolyticus to the extracellular matrix. Unexpectedly

  19. Acriflavine-Resistant Mutant of Streptococcus cremoris†

    PubMed Central

    Sinha, R.P.

    1977-01-01

    Selection for resistance to acriflavine in Streptococcus cremoris resulted in cross-resistance to the drugs neomycin, streptomycin, ethidium bromide, mitomycin C, and proflavine. Furthermore, the mutants showed resistance to lytic bacteriophages to which the parental strain was sensitive, and, unlike the parent, the mutants grew well at higher temperatures (40°C). Revertants selected independently either for temperature sensitivity or for acriflavine sensitivity lost resistance to all the drugs and dyes but retained the bacteriophage resistance phenotype. The acriflavine-resistant mutation resulted in an increase in resistance by the bacterial cells to sodium dodecyl sulfate, a potent solvent of lipopolysaccharide and lipoprotein. It is suggested that the acriflavine resistance mutation determines the synthesis of a membrane substance resistant to higher temperatures. PMID:907329

  20. Murine models of Streptococcus pyogenes infection.

    PubMed

    Roberts, Samantha; Scott, June R; Husmann, Linda K; Zurawski, Christine A

    2006-09-01

    This unit describes procedures for testing virulence of Streptococcus pyogenes in mice. S. pyogenes is an important human pathogen and causes one of the most common childhood diseases. The syndromes that result from S. pyogenes infection are diverse, ranging from mild, superficial throat or skin infection to severe, invasive disea/se that is often lethal. Thus, a greater understanding of the virulence factors of this bacterium and development of modalities to prevent or relieve the infections it causes are important. Since S. pyogenes is a strictly human pathogen (with the exception of a single strain), the value of all animal models is limited. This unit describes a model for long-term throat colonization following the natural route of infection (inhalation), one for pneumonia and systemic dissemination following intratracheal inoculation, and one for systemic dissemination following the more natural route of skin infection. In addition, methods are presented for culturing S. pyogenes from tissues of the infected animal.

  1. Development of Streptococcus agalactiae vaccines for tilapia.

    PubMed

    Liu, Guangjin; Zhu, Jielian; Chen, Kangming; Gao, Tingting; Yao, Huochun; Liu, Yongjie; Zhang, Wei; Lu, Chengping

    2016-12-21

    Vaccination is a widely accepted and effective method to prevent most pathogenic diseases in aquaculture. Various species of tilapia, especially Nile tilapia Oreochromis niloticus, are farmed worldwide because of their high consumer demand. Recently, the tilapia-breeding industry has been hampered by outbreaks of Streptococcus agalactiae infection, which cause high mortality and huge economic losses. Many researchers have attempted to develop effective S. agalactiae vaccines for tilapia. This review provides a summary of the different kinds of S. agalactiae vaccines for tilapia that have been developed recently. Among the various vaccine types, inactivated S. agalactiae vaccines showed superior protection efficiency when compared with live attenuated, recombinant and DNA vaccines. With respect to vaccination method, injecting the vaccine into tilapia provided the most effective immunoprotection. Freund's incomplete adjuvant appeared to be suitable for tilapia vaccines. Other factors, such as immunization duration and number, fish size and challenge dose, also influenced the vaccine efficacy.

  2. Mechanisms of genome evolution of Streptococcus.

    PubMed

    Andam, Cheryl P; Hanage, William P

    2015-07-01

    The genus Streptococcus contains 104 recognized species, many of which are associated with human or animal hosts. A globally prevalent human pathogen in this group is Streptococcus pneumoniae (the pneumococcus). While being a common resident of the upper respiratory tract, it is also a major cause of otitis media, pneumonia, bacteremia and meningitis, accounting for a high burden of morbidity and mortality worldwide. Recent findings demonstrate the importance of recombination and selection in driving the population dynamics and evolution of different pneumococcal lineages, allowing them to successfully evade the impacts of selective pressures such as vaccination and antibiotic treatment. We highlight the ability of pneumococci to respond to these pressures through processes including serotype replacement, capsular switching and horizontal gene transfer (HGT) of antibiotic resistance genes. The challenge in controlling this pathogen also lies in the exceptional genetic and phenotypic variation among different pneumococcal lineages, particularly in terms of their pathogenicity and resistance to current therapeutic strategies. The widespread use of pneumococcal conjugate vaccines, which target only a small subset of the more than 90 pneumococcal serotypes, provides us with a unique opportunity to elucidate how the processes of selection and recombination interact to generate a remarkable level of plasticity and heterogeneity in the pneumococcal genome. These processes also play an important role in the emergence and spread of multi-resistant strains, which continues to pose a challenge in disease control and/or eradication. The application of population of genomic approaches at different spatial and temporal scales will help improve strategies to control this global pathogen, and potentially other pathogenic streptococci.

  3. Contralateral compartment syndrome inoculated by invasive group A streptococcus

    PubMed Central

    Chen, Huiwen; Mcphillips, Sean Thomas; Chundi, Vishnu

    2016-01-01

    Compartment syndrome is a rare but a well-documented complication in patients with trauma-induced group A streptococcus infection. Here, we present a case of a male who developed compartment syndrome on the left lower extremity after an injury inoculated by group A streptococcus on the right lower extremity. The patient was resuscitated with antibiotics, urgent fasciotomy, and immunoglobulin. The patient was eventually transferred to a burn center for further care. PMID:27802865

  4. Streptococcus rubneri sp. nov., isolated from the human throat.

    PubMed

    Huch, Melanie; De Bruyne, Katrien; Cleenwerck, Ilse; Bub, Achim; Cho, Gyu-Sung; Watzl, Bernhard; Snauwaert, Isabel; Franz, Charles M A P; Vandamme, Peter

    2013-11-01

    The novel, Gram-stain-positive, ovoid, lactic acid bacterial isolates LMG 27205, LMG 27206, LMG 27207(T) and MRI-F 18 were obtained from throat samples of healthy humans. 16S rRNA gene sequence analyses indicated that these isolates belong to the genus Streptococcus, specifically the Streptococcus mitis group, with Streptococcus australis and Streptococcus mitis as the nearest neighbours (99.45 and 98.56 % 16S rRNA gene sequence similarity to the respective type strains). Genotypic fingerprinting by fluorescent amplified fragment length polymorphism (FAFLP) and pulsed-field gel electrophoresis (PFGE), DNA-DNA hybridizations, comparative sequence analysis of pheS, rpoA and atpA and physiological and biochemical tests revealed that these bacteria formed a taxon well separated from its nearest neighbours and other species of the genus Streptococcus with validly published names and, therefore, represent a novel species, for which the name Streptococcus rubneri sp. nov. is proposed, with LMG 27207(T) ( = DSM 26920(T)) as the type strain.

  5. [Presence of Streptococcus bovis in urine samples from patients experiencing symptoms of urinary tract].

    PubMed

    Gómez-Camarasa, Cristina; Gutiérrez Soto, Blanca; Jiménez-Guerra, Gemma; Sorlózano Puerto, Antonio; Navarro-Marí, José María; Gutiérrez-Fernández, José

    Given the relevance of proper clinical validation of Streptococcus bovis, we here consider revising its presence in urine samples in order to determine its relative frequency and the pattern of antibiotic susceptibility. The susceptibility to antibiotics of 91 isolates of S. bovis from urine samples was retrospectively reviewed over a period of 4 years (2012-2015). The mean age of patients was 55 years, 81% of whom were women and 37.4% were hospitalized patients suffering from urological diseases (61%). Susceptibility to penicillin, vancomycin and teicoplanin was 97.8%. Due to the fact that S. bovis can be infrequent in urine isolates and given its presence in patients suffering from urological diseases, further pathogenic studies, showing the true ability of this group of bacteria to produce disease, are required. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae

    PubMed Central

    Wang, Deguo; Liu, Yanhong

    2015-01-01

    Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactiae, S. uberis and S. agalactiae. The detection limit of all four LAMP primer sets were 0.1 pg DNA template per reaction, the LAMP method with 16S rRNA gene and 16S-23S rRNA intergenic spacers as the targets can differentiate the three pathogens, which is potentially useful in epidemiological studies. PMID:26016433

  7. Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae.

    PubMed

    Wang, Deguo; Liu, Yanhong

    2015-05-26

    Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactiae, S. uberis and S. agalactiae. The detection limit of all four LAMP primer sets were 0.1 pg DNA template per reaction, the LAMP method with 16S rRNA gene and 16S-23S rRNA intergenic spacers as the targets can differentiate the three pathogens, which is potentially useful in epidemiological studies.

  8. Prophage lysin Ply30 protects mice from Streptococcus suis and Streptococcus equi subsp. zooepidemicus infections.

    PubMed

    Tang, Fang; Li, Dezhi; Wang, Haojin; Ma, Zhe; Lu, Chengping; Dai, Jianjun

    2015-11-01

    Streptococcus suis and Streptococcus equi subsp. zooepidemicus are capable of infecting humans and various animals, causing significant problems for the worldwide swine industry. As antibiotic resistance has increased, lysosomal enzymes encoded by phages have shown potential for use against pathogenic bacteria. In this study, a novel bacteriophage lysin, Ply30, encoded by the S. suis prophage phi30c, was recombinantly expressed and purified. Ply30 showed high bacteriolysis activity on S. suis and S. equi subsp. zooepidemicus in vitro. The ratio of the optical density at 600 nm (OD600) with treatment versus the OD600 with no treatment for most tested S. suis and S. equi subsp. zooepidemicus strains decreased from 1 to <0.3 and <0.5, respectively, within 1 h. The results of plate viability assays showed that treated bacteria suffered a 1- to 2-log decrease in CFU within 1 h. The optimal concentration of Ply30 was 50 μg/ml, and the optimal pH was 7. Moreover, Ply30 maintained high activity over a wide pH range (pH 6 to 10). The MICs of Ply30 against Streptococcus strains ranged from 16 to 512 μg/ml. In vivo, a 2-mg dose of Ply30 protected 90% (9/10 mice) of mice from infection with S. equi subsp. zooepidemicus and 80% (8/10 mice) of mice from infection with S. suis. Seven days after lysin Ply30 treatment, bacterial loads were significantly decreased in all tested organs and blood compared with those at 1 h postinfection without Ply30 treatment. Ply30 showed in vitro and in vivo antimicrobial efficiency and protected mice against two kinds of bacterial infections, indicating that Ply30 may be an effective therapeutic against streptococci. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Transfection of Streptococcus sanguis by phage deoxyribonucleic acid isolated from Streptococcus mutans.

    PubMed

    Higuchi, M; Rhee, G H; Araya, S; Higuchi, M

    1977-03-01

    Streptococcus sanguis ATCC 10556 cells were infected with free phage DNA of S, mutans strain PK 1. Two transformants were isolated which made colonies with large mucoid forms on mitis-salivarius agar. Both transformants had an increased ability to synthesize insoluble glucan and showed an adhesive nature on glass surfaces. These characteristics of the transformants bear a resemblance to S. mutans. These transformants had many physiological characteristics by which they could be recognized as S. sanguis. However, they resembled S. salivarius in forming a large amount of soluble fructan. Furthermore, the transformant cells did not produce ammonia from arginine, whereas their parent cells did.

  10. Antibiotic Selection Pressure and Resistance in Streptococcus pneumoniae and Streptococcus pyogenes

    PubMed Central

    Albrich, Werner C.; Monnet, Dominique L.

    2004-01-01

    We correlated outpatient antibiotic use with prevalence of penicillin-nonsusceptible Streptococcus pneumoniae (PNSP), macrolide-resistant S. pneumoniae (MRSP), and macrolide-resistant S. pyogenes (MRGAS) in 20 countries. Total antibiotic use was correlated with PNSP (r = 0.75; p < 0.001), as was macrolide use with MRSP (r = 0.88; p < 0.001) and MRGAS (r = 0.71; p = 0.004). Streptococcal resistance is directly associated with antibiotic selection pressure on a national level. PMID:15109426

  11. Capsular typing of Streptococcus agalactiae (Lancefield group B streptococci) from fish using multiplex PCR and serotyping

    USDA-ARS?s Scientific Manuscript database

    Streptococcus spp. including Streptococcus agalactiae (Lancefield group B streptococci) are considered emerging pathogens responsible for approximately $1 billion USD in annual losses to the global tilapia (Oreochromis sp.) aquaculture industry. This study evaluated a published multiplex PCR capsul...

  12. [Necrotizing fasciitis, myositis, arthritis, and streptococcal toxic shock syndrome caused by group G Streptococcus. Report of one case].

    PubMed

    Ayala-Gaytán, Juan Jacobo; Martínez-Vela, Ángel; Náñez-Terreros, Homero; Guajardo-Lara, Claudia Elena; Valdovinos-Chávez, Salvador Bruno

    2014-01-01

    Introducción: ocasionalmente concurren la fascitis necrotizante (FN), con miositis, y síndrome de choque tóxico post-estreptocócico (SSTE) asociados con infección por estreptococo ß-hemolítico del grupo G (EGG). Caso clínico: presentamos un caso de infección en el que concurren simultáneamente FN, miositis, artritis y SSTE en una mujer de 83 años con secuelas de enfermedad cerebrovascular, hospitalizada tras dos días de fiebre y dolor, así como hinchazón del pie izquierdo. Se encontraba hipotensa y el pie mostraba coloración púrpura con flictenas que se extendían hacia el tercio inferior de la pierna; no había crepitación a la presión digital. Se empleó hidratación parenteral, vasopresores, tigeciclina y clindamicina. Tanto el tejido desbridado como el líquido aspirado de la articulación de la rodilla revelaron cocos gram positivos. Al quinto día la paciente desarrolló falla renal y respiratoria que requirieron de apoyo. La paciente fue sometida a amputación supracondílea de la pierna izquierda; después de eso, su condición mejoró. Un mes después fue dada de alta. Conclusiones: el EGG puede causar infecciones potencialmente mortales, como FN, miositis, y/o SSTE. El EGG por lo general afecta a pacientes ancianos con estados comórbidos y ocasionalmente a sujetos sanos.

  13. Exogenous Streptococcus pneumoniae Endophthalmitis in Diabetic Rabbits

    PubMed Central

    Benton, Angela H.; Fulton, Linda K.; Marquart, Mary E.

    2017-01-01

    Diabetics are at increased risk for eye infections including bacterial endophthalmitis. It is unclear whether the severity of endophthalmitis is greater in these patients due to confounding factors such as pre-existing ocular diseases in some but not others. Therefore, we tested the hypothesis that disease severity and/or bacterial loads would be significantly higher in a Type I diabetic rabbit model of Streptococcus pneumoniae endophthalmitis. Rabbits were treated with alloxan to destroy pancreatic islet cells, or mock-treated with vehicle, and maintained for 10 days before intravitreal infection with S. pneumoniae E353. Clinical scoring of the eyes was performed 24 and 48 hours after infection, followed by euthanasia and vitreous harvest to quantitate bacterial loads. There were no significant differences in clinical scores (P ≥ 0.440) or bacterial loads (P = 0.736), however, 4/12 (33%) of the diabetic rabbits became bacteremic. This finding not only indicates a breakdown in the blood-ocular barrier, but also prompts further investigation into the exploitation of the diabetic eye by the streptococci. PMID:28387365

  14. Export Requirements of Pneumolysin in Streptococcus pneumoniae

    PubMed Central

    Price, Katherine E.; Greene, Neil G.

    2012-01-01

    Streptococcus pneumoniae is a major causative agent of otitis media, pneumonia, bacteremia, and meningitis. Pneumolysin (Ply), a member of the cholesterol-dependent cytolysins (CDCs), is produced by virtually all clinical isolates of S. pneumoniae, and ply mutant strains are severely attenuated in mouse models of colonization and infection. In contrast to all other known members of the CDC family, Ply lacks a signal peptide for export outside the cell. Instead, Ply has been hypothesized to be released upon autolysis or, alternatively, via a nonautolytic mechanism that remains undefined. We show that an exogenously added signal sequence is not sufficient for Sec-dependent Ply secretion in S. pneumoniae but is sufficient in the surrogate host Bacillus subtilis. Previously, we showed that Ply is localized primarily to the cell wall compartment in the absence of detectable cell lysis. Here we show that Ply released by autolysis cannot reassociate with intact cells, suggesting that there is a Ply export mechanism that is coupled to cell wall localization of the protein. This putative export mechanism is capable of secreting a related CDC without its signal sequence. We show that B. subtilis can export Ply, suggesting that the export pathway is conserved. Finally, through truncation and domain swapping analyses, we show that export is dependent on domain 2 of Ply. PMID:22563048

  15. Sodium-stimulated ATPase in Streptococcus faecalis.

    PubMed Central

    Kinoshita, N; Unemoto, T; Kobayashi, H

    1984-01-01

    We measured Na+-stimulated ATPase activity in a mutant of Streptococcus faecalis defective in the generation of proton motive force. The activity in membrane vesicles was 62.1 +/- 5.9 nmol of phosphate produced per min per mg of protein when cells were grown on medium containing 0.12 M Na+. Activity decreased as the concentration of Na+ in the growth medium decreased. The decrease in enzyme activity corresponded to the decrease in transport activity for Na+ in both whole cells and membrane vesicles. The effects of pH on both activities were identical. Thus, it is suggested that Na+ movement is mediated by this enzyme. Sodium extrusion and ATPase activity in the wild-type strain were markedly lower than those observed in the mutant strain. Elevated activities of both Na+ extrusion and Na+-stimulated ATPase could be detected in the wild-type strain when cells were grown in the absence of proton motive force. Thus, we propose that the level of ATPase is increased by dissipation of the proton motive force. PMID:6144668

  16. Role of hyaluronidase in Streptococcus intermedius biofilm.

    PubMed

    Pecharki, D; Petersen, F C; Scheie, A Aa

    2008-03-01

    Streptococcus intermedius is found in biofilms on teeth and as a commensal member of the gastrointestinal and urinary floras, but may also be associated with deep-seated purulent infections and infective endocarditis. S. intermedius produces hyaluronidase, an enzyme that breaks down hyaluronan (HA), a major component of the extracellular matrix of connective tissue. We investigated the involvement of hyaluronidase in S. intermedius biofilm formation and dispersal as well as adhesion to human cells. The hyaluronidase activity and expression of the hyl gene were higher in growth media supplemented with HA. Inactivation of the S. intermedius hyaluronidase resulted in a mutant that formed up to 31 % more biofilm in media supplemented with HA. Hyaluronidase added to the medium caused dispersal of S. intermedius biofilm. Adhesion to epithelial cells was similar in the wild-type and the hyaluronidase mutant. We concluded that hyaluronidase may be important for S. intermedius detachment from biofilms but not for adhesion to epithelial cells. The ability of S. intermedius to detach from the surface and to spread may be crucial in the pathogenicity of this micro-organism.

  17. Thermal Injury and Recovery of Streptococcus faecalis

    PubMed Central

    Clark, Carol W.; Witter, Lloyd D.; Ordal, Z. John

    1968-01-01

    Exposure of Streptococcus faecalis R57 to sublethal heating produced a temporary change in the salt tolerance and growth of the organism. After sublethal heat treatment at 60 C for 15 min, greater than 99.0% of the viable population was unable to reproduce on media containing 6% NaCl. In addition, the heated cells displayed a sensitivity to incubation temperature, pH, and 0.01% methylene blue. When the injured cells were placed in a synthetic medium, recovery occurred at a much slower rate than in a complex medium. However, both media supported comparable growth of the uninjured organism. Various media used for the enrichment of streptococci also provided a suitable environment for the recovery of the injured cells. Generally, as more selective agents were present in the medium, the rates of recovery decreased. Metabolic inhibitor studies with chloramphenicol, penicillin, and actinomycin D substantiated the fact that the process involved was recovery and not growth, and that this recovery was linked to ribonucleic acid synthesis. PMID:4973066

  18. Fumarate Reductase Activity of Streptococcus faecalis

    PubMed Central

    Aue, B. J.; Diebel, R. H.

    1967-01-01

    Some characteristics of a fumarate reductase from Streptococcus faecalis are described. The enzyme had a pH optimum of 7.4; optimal activity was observed when the ionic strength of the phosphate buffer was adjusted to 0.088. The Km value of the enzyme for reduced flavin mononucleotide was 2 × 10−4 m as determined with a 26-fold preparation. In addition to fumarate, the enzyme reduced maleate and mesaconate. No succinate dehydrogenase activity was detected, but succinate did act as an inhibitor of the fumarate reductase activity. Other inhibitors were malonate, citraconate, and trans-, trans-muconate. Metal-chelating agents did not inhibit the enzyme. A limited inhibition by sulfhydryl-binding agents was observed, and the preparations were sensitive to air oxidation and storage. Glycine, alanine, histidine, and possibly lysine stimulated fumarate reductase activity in the cell-free extracts. However, growth in media supplemented with glycine did not enhance fumarate reductase activity. The enzymatic activity appears to be constitutive. PMID:4960892

  19. Quorum sensing in group A Streptococcus

    PubMed Central

    Jimenez, Juan Cristobal; Federle, Michael J.

    2014-01-01

    Quorum sensing (QS) is a widespread phenomenon in the microbial world that has important implications in the coordination of population-wide responses in several bacterial pathogens. In Group A Streptococcus (GAS), many questions surrounding QS systems remain to be solved pertaining to their function and their contribution to the GAS lifestyle in the host. The QS systems of GAS described to date can be categorized into four groups: regulator gene of glucosyltransferase (Rgg), Sil, lantibiotic systems, and LuxS/AI-2. The Rgg family of proteins, a conserved group of transcription factors that modify their activity in response to signaling peptides, has been shown to regulate genes involved in virulence, biofilm formation and competence. The sil locus, whose expression is regulated by the activity of signaling peptides and a putative two-component system (TCS), has been implicated on regulating genes involved with invasive disease in GAS isolates. Lantibiotic regulatory systems are involved in the production of bacteriocins and their autoregulation, and some of these genes have been shown to target both bacterial organisms as well as processes of survival inside the infected host. Finally AI-2 (dihydroxy pentanedione, DPD), synthesized by the LuxS enzyme in several bacteria including GAS, has been proposed to be a universal bacterial communication molecule. In this review we discuss the mechanisms of these four systems, the putative functions of their targets, and pose critical questions for future studies. PMID:25309879

  20. Streptococcus equi meningoencephalomyelitis in a foal.

    PubMed

    Finno, Carrie; Pusterla, Nicola; Aleman, Monica; Mohr, F Charles; Price, Teena; George, Jeanne; Holmberg, Tara

    2006-09-01

    A 4-month-old American Paint Horse colt was evaluated because of acute onset of ataxia, left-sided head tilt, and fever and a recently noticed heart murmur. Upper respiratory tract infection caused by Streptococcus equi subsp equi had been diagnosed at 3 months of age. Hematologic abnormalities included leukocytosis, mature neutrophilia, monocytosis, and mild anemia. Analysis of a CSF sample revealed high total protein concentration and total nucleated cell count; nucleated cells consisted mainly of degenerate neutrophils. Results of a real-time PCR assay were positive for S equi subsp equi, and a diagnosis of S equi subsp equi meningoencephalomyelitis was made. Treatment included administration of potassium penicillin and fluids, but the foal developed uroperitoneum and was subsequently euthanized. Postmortem examination revealed meningoencephalomyelitis, and S equi subsp equi was cultured from a brain aspirate. Additional findings included suppurative cystitis with rupture and neutrophilic myocarditis. Findings suggest that S equi subsp equi meningoencephalomyelitis should be considered in the differential diagnosis for foals with neurologic signs that have a history of strangles or exposure to affected horses.

  1. Ornithine transport and exchange in Streptococcus lactis

    SciTech Connect

    Thompson, J.

    1987-09-01

    Resting cells of Streptococcus lactis 133 appeared to accumulate (/sup 14/C)ornithine to a high concentration in the absence of an exogenous energy source. However, analysis of intracellular amino acid pool constituents and results of transport experiments revealed that the accumulation of ornithine represented a homoexchange between extracellular (/sup 14/C)ornithine and unlabeled ornithine in the cell. The energy-independent exchange of ornithine was not inhibited by proton-conducting uncouplers or by metabolic inhibitors. Intracellular (/sup 14/C)ornithine was retained by resting cells after suspension in a buffered medium. However, addition of unlabeled ornithine to the suspension elicited rapid exit of labeled amino acid. The initial rate of exist of (/sup 14/C)ornithine was dependent on the concentration of unlabeled ornithine in the medium, but this accelerative exchange diffusion process caused no net loss of amino acid. By contrast, the presence of a fermentable energy source caused a rapid expulsion of and new decrease in the concentration of intracellular ornithine. Kinetic analyses of amino acid transport demonstrated competitive inhibition between lysine and ornithine, and data obtained by two-dimensional thin-layer chromatography established the heteroexchange of these basic amino acids. The effects of amino acids and of ornithine analogs on both entry and exit of (/sup 14/C)ornithine have been examined. The data suggest that common carrier mediates the entry and exchange of lysine, arginine, and ornithine in cells of S. lactis.

  2. Horizontal transmission of streptococcus mutans in schoolchildren

    PubMed Central

    Castillo, Ana M.; Liébana, Maria J.; Castillo, Francisca; Martín-Platero, Antonio; Liébana, José

    2012-01-01

    Objetive: The aim of this study was to analyze possible horizontal transmission patterns of S. mutans among 6-7-yr-old schoolchildren from the same class, identifying genotypes and their diversity and relationship with caries disease status. Study Design: Caries indexes and saliva mutans streptococci and lactobacilli counts were recorded in 42 schoolchildren. Mutans streptococci colonies were identified by means of biochemical tests and all S. mutans strains were genotyped by arbitrarily primed polymerase chain reaction. A child was considered free of S. mutans when it could not be isolated in 3 samples at 1-week intervals. Results: S. mutans was isolated in 30 schoolchildren: 20 having one genotype and 10 two genotypes. Higher mutans streptococci and caries index values were found in those with two genotypes. Five genotypes were isolated in more than 1 schoolchild and one of these was isolated in 3 schoolchildren. Our results suggest that horizontal transmission may take place. Conclusion: Schoolchildren aged 6-7 yrs may be the source of mutual transmission of S. mutans. Key words:Streptococcus mutans, Horizontal transmission, AP-PCR, genotyping PMID:22143733

  3. Quorum sensing in group A Streptococcus.

    PubMed

    Jimenez, Juan Cristobal; Federle, Michael J

    2014-01-01

    Quorum sensing (QS) is a widespread phenomenon in the microbial world that has important implications in the coordination of population-wide responses in several bacterial pathogens. In Group A Streptococcus (GAS), many questions surrounding QS systems remain to be solved pertaining to their function and their contribution to the GAS lifestyle in the host. The QS systems of GAS described to date can be categorized into four groups: regulator gene of glucosyltransferase (Rgg), Sil, lantibiotic systems, and LuxS/AI-2. The Rgg family of proteins, a conserved group of transcription factors that modify their activity in response to signaling peptides, has been shown to regulate genes involved in virulence, biofilm formation and competence. The sil locus, whose expression is regulated by the activity of signaling peptides and a putative two-component system (TCS), has been implicated on regulating genes involved with invasive disease in GAS isolates. Lantibiotic regulatory systems are involved in the production of bacteriocins and their autoregulation, and some of these genes have been shown to target both bacterial organisms as well as processes of survival inside the infected host. Finally AI-2 (dihydroxy pentanedione, DPD), synthesized by the LuxS enzyme in several bacteria including GAS, has been proposed to be a universal bacterial communication molecule. In this review we discuss the mechanisms of these four systems, the putative functions of their targets, and pose critical questions for future studies.

  4. Peptide pheromone signaling in Streptococcus and Enterococcus.

    PubMed

    Cook, Laura C; Federle, Michael J

    2014-05-01

    Intercellular chemical signaling in bacteria, commonly referred to as quorum sensing (QS), relies on the production and detection of compounds known as pheromones to elicit coordinated responses among members of a community. Pheromones produced by Gram-positive bacteria are comprised of small peptides. Based on both peptide structure and sensory system architectures, Gram-positive bacterial signaling pathways may be classified into one of four groups with a defining hallmark: cyclical peptides of the Agr type, peptides that contain Gly-Gly processing motifs, sensory systems of the RNPP family, or the recently characterized Rgg-like regulatory family. The recent discovery that Rgg family members respond to peptide pheromones increases substantially the number of species in which QS is likely a key regulatory component. These pathways control a variety of fundamental behaviors including conjugation, natural competence for transformation, biofilm development, and virulence factor regulation. Overlapping QS pathways found in multiple species and pathways that utilize conserved peptide pheromones provide opportunities for interspecies communication. Here we review pheromone signaling identified in the genera Enterococcus and Streptococcus, providing examples of all four types of pathways. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  5. Ecology and pathogenicity of gastrointestinal Streptococcus bovis.

    PubMed

    Herrera, Paul; Kwon, Young Min; Ricke, Steven C

    2009-01-01

    Streptococcus bovis is an indigenous resident in the gastrointestinal tracts of both humans and animals. S. bovis is one of the major causes of bacterial endocarditis and has been implicated in the incidence of human colon cancer, possibly due to chronic inflammatory response at the site of intestinal colonization. Certain feeding regimens in ruminants can lead to overgrowth of S. bovis in the rumen, resulting in the over-production of lactate and capsular polysaccharide causing acute ruminal acidosis and bloat, respectively. There are multiple strategies in controlling acute lactic acidosis and bloat. The incidence of the two diseases may be controlled by strict dietary management. Gradual introduction of grain-based diets and the feeding of coarsely chopped roughage decrease the incidence of the two disease entities. Ionophores, which have been used to enhance feed conversion and growth rate in cattle, have been shown to inhibit the growth of lactic acid bacteria in the rumen. Other methods of controlling lactic acid bacteria in the ruminal environment (dietary supplementation of long-chain fatty acids, induction of passive and active immune responses to the bacteria, and the use of lytic bacteriophages) have also been investigated. It is anticipated that through continued in-depth ecological analysis of S. bovis the characteristics responsible for human and animal pathogenesis would be sufficiently identified to a point where more effective control strategies for the control of this bacteria can be developed.

  6. Parallel Evolution in Streptococcus pneumoniae Biofilms

    PubMed Central

    Churton, Nicholas W. V.; Misra, Raju V.; Howlin, Robert P.; Allan, Raymond N.; Jefferies, Johanna; Faust, Saul N.; Gharbia, Saheer E.; Edwards, Richard J.; Clarke, Stuart C.; Webb, Jeremy S.

    2016-01-01

    Streptococcus pneumoniae is a commensal human pathogen and the causative agent of various invasive and noninvasive diseases. Carriage of the pneumococcus in the nasopharynx is thought to be mediated by biofilm formation, an environment where isogenic populations frequently give rise to morphological colony variants, including small colony variant (SCV) phenotypes. We employed metabolic characterization and whole-genome sequencing of biofilm-derived S. pneumoniae serotype 22F pneumococcal SCVs to investigate diversification during biofilm formation. Phenotypic profiling revealed that SCVs exhibit reduced growth rates, reduced capsule expression, altered metabolic profiles, and increased biofilm formation compared to the ancestral strain. Whole-genome sequencing of 12 SCVs from independent biofilm experiments revealed that all SCVs studied had mutations within the DNA-directed RNA polymerase delta subunit (RpoE). Mutations included four large-scale deletions ranging from 51 to 264 bp, one insertion resulting in a coding frameshift, and seven nonsense single-nucleotide substitutions that result in a truncated gene product. This work links mutations in the rpoE gene to SCV formation and enhanced biofilm development in S. pneumoniae and therefore may have important implications for colonization, carriage, and persistence of the organism. Furthermore, recurrent mutation of the pneumococcal rpoE gene presents an unprecedented level of parallel evolution in pneumococcal biofilm development. PMID:27190203

  7. Parallel Evolution in Streptococcus pneumoniae Biofilms.

    PubMed

    Churton, Nicholas W V; Misra, Raju V; Howlin, Robert P; Allan, Raymond N; Jefferies, Johanna; Faust, Saul N; Gharbia, Saheer E; Edwards, Richard J; Clarke, Stuart C; Webb, Jeremy S

    2016-05-09

    Streptococcus pneumoniae is a commensal human pathogen and the causative agent of various invasive and noninvasive diseases. Carriage of the pneumococcus in the nasopharynx is thought to be mediated by biofilm formation, an environment where isogenic populations frequently give rise to morphological colony variants, including small colony variant (SCV) phenotypes. We employed metabolic characterization and whole-genome sequencing of biofilm-derived S. pneumoniae serotype 22F pneumococcal SCVs to investigate diversification during biofilm formation. Phenotypic profiling revealed that SCVs exhibit reduced growth rates, reduced capsule expression, altered metabolic profiles, and increased biofilm formation compared to the ancestral strain. Whole-genome sequencing of 12 SCVs from independent biofilm experiments revealed that all SCVs studied had mutations within the DNA-directed RNA polymerase delta subunit (RpoE). Mutations included four large-scale deletions ranging from 51 to 264 bp, one insertion resulting in a coding frameshift, and seven nonsense single-nucleotide substitutions that result in a truncated gene product. This work links mutations in the rpoE gene to SCV formation and enhanced biofilm development in S. pneumoniae and therefore may have important implications for colonization, carriage, and persistence of the organism. Furthermore, recurrent mutation of the pneumococcal rpoE gene presents an unprecedented level of parallel evolution in pneumococcal biofilm development. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  8. Peptide pheromone signaling in Streptococcus and Enterococcus

    PubMed Central

    Cook, Laura C.; Federle, Michael J.

    2014-01-01

    Intercellular chemical signaling in bacteria, commonly referred to as quorum sensing (QS), relies on the production and detection of compounds known as pheromones to elicit coordinated responses among members of a community. Pheromones produced by Gram-positive bacteria are comprised of small peptides. Based on both peptide structure and sensory system architectures, Gram-positive bacterial signaling pathways may be classified into one of four groups with a defining hallmark: cyclical peptides of the Agr type, peptides that contain Gly-Gly processing motifs, sensory systems of the RNPP family, or the recently characterized Rgg-like regulatory family. The recent discovery that Rgg family members respond to peptide pheromones increases substantially the number of species in which QS is likely a key regulatory component. These pathways control a variety of fundamental behaviors including conjugation, natural competence for transformation, biofilm development, and virulence factor regulation. Overlapping QS pathways found in multiple species and pathways that utilize conserved peptide pheromones provide opportunities for interspecies communication. Here we review pheromone signaling identified in the genera Enterococcus and Streptococcus, providing examples of all four types of pathways. PMID:24118108

  9. Conjugal mobilization of the mega element carrying mef(E) from Streptococcus salivarius to Streptococcus pneumoniae.

    PubMed

    Santagati, Maria; Lupo, Agnese; Scillato, Marina; Di Martino, Andrea; Stefani, Stefania

    2009-01-01

    We report the isolation and characterization of an unusual strain of Streptococcus salivarius, 3C30, displaying both the macrolide-lincosamide-streptogramin B and the tetracycline resistance phenotypes. It harbours the mef(E), erm(B), and tet(M) genes carried by different genetic elements. The genetic element carrying mef(E), named mega, was investigated by long PCR and sequencing, while the presence of the Tn3872-like element, carrying tet(M) and erm(B), was demonstrated by sequencing of both the int-xis-Tn and the fragment between the two resistance genes. In strain 3C30 the mega element is 5388 bp in size and its nucleotide sequence is identical to that of the element described previously in S. salivarius, with the exception of a 912 bp deletion at the left end. The composite Tn3872-like element appeared to be nonconjugative while the mega element was transferred by conjugation to Streptococcus pneumoniae. It was, however, impossible to transfer it again from these transconjugants to other strains. In addition, only in the 3C30 strain did mega form circular structures, as identified by real-time PCR. In conclusion, we found a clinical strain of S. salivarius carrying both mega and Tn3872-like genetic elements. Mega is transferable by conjugation to S. pneumoniae but it is not transferable again from the transconjugants, suggesting a possible mobilization by recombinases of the coresident Tn3872-like transposon.

  10. Caries experience and quantification of Streptococcus mutans and Streptococcus sobrinus in saliva of Sudanese schoolchildren.

    PubMed

    Nurelhuda, Nazik M; Al-Haroni, M; Trovik, T A; Bakken, V

    2010-01-01

    Streptococcus mutans and Streptococcus sobrinus are among the most commonly isolated bacterial species implicated as etiological agents of dental caries. Details of the composition of the oral microflora related to dental caries should aid in assessing the prevalence and risk of disease at an individual level. The aim of the present study was to determine the presence and relative amounts of S. mutans and S. sobrinus in the saliva samples obtained from schoolchildren in Khartoum State, the Sudan, and to study the association of the amounts of S. mutans and S. sobrinus with caries experience, socioeconomic status and sugar-sweetened snacks in this population. 140 samples, 30 of which were from individuals with caries experience, were examined using quantitative real-time polymerase chain reaction (qRT-PCR) with specific oligonucleotide primers. The mean ratio of fold differences of S. mutans to S. sobrinus was 0.77 (SD 5.4) and 2.29 (SD 6.0) for samples obtained from caries-free and caries-active individuals, respectively. This suggested that the proportion of S. sobrinus was higher than S.mutans in the caries-active group when compared to the caries-free group. An association was found between children with caries-active lesions and the frequent consumption of sticky desserts and higher socioeconomic status. S. sobrinus seems to be associated with caries experience in the studied population. A proposal of caries screening programs designed to test for S. sobrinus in this population may be developed.

  11. Functional variation of the antigen I/II surface protein in Streptococcus mutans and Streptococcus intermedius.

    PubMed

    Petersen, F C; Assev, S; van der Mei, H C; Busscher, H J; Scheie, A A

    2002-01-01

    Although Streptococcus intermedius and Streptococcus mutans are regarded as members of the commensal microflora of the body, S. intermedius is often associated with deep-seated purulent infections, whereas S. mutans is frequently associated with dental caries. In this study, we investigated the roles of the S. mutans and S. intermedius antigen I/II proteins in adhesion and modulation of cell surface characteristics. By using isogenic mutants, we show that the antigen I/II in S. mutans, but not in S. intermedius, was involved in adhesion to a salivary film under flowing conditions, as well as in binding to rat collagen type I. Binding to human fibronectin was a common function associated with the S. mutans and S. intermedius antigen I/II. Adhesion of S. mutans or S. intermedius to human collagen types I or IV was negligible. Hydrophobicity, as measured by water contact angles, and zeta potentials were unaltered in the S. intermedius mutant. The S. mutans isogenic mutants, on the other hand, exhibited more positive zeta potentials at physiological pH values than did the wild type. The results indicate common and species-specific roles for the antigen I/II in mediating the attachment of S. mutans and S. intermedius to host components and in determining cell surface properties.

  12. Inhibitory effects of antiseptic mouthrinses on Streptococcus mutans, Streptococcus sanguinis and Lactobacillus acidophilus.

    PubMed

    Evans, A; Leishman, S J; Walsh, L J; Seow, W K

    2015-06-01

    Oral antiseptics are valuable in controlling oral infections caused by cariogenic bacteria. The aim of this study was to investigate the effects of mouthrinses and pure antiseptic compounds on Streptococcus mutans and non-mutans bacteria (Streptococcus sanguinis and Lactobacillus acidophilus). The agar diffusion assay was employed to determine bacterial growth inhibition. Commercial mouthrinses containing chlorhexidine gluconate (0.2%), cetylpyridinium chloride (0.05%) and sodium fluoride (0.05%) produced statistically similar growth inhibition of S. mutans, S. sanguinis and L. acidophilus (with zones of inhibition ranging from 7.56 ± 0.52 mm to 7.39 ± 0.53 mm, 17.44 ± 0.94 mm to 18.31 ± 0.62 mm and 8.61 ± 1.43 to 8.67 ± 1.43 mm respectively, p > 0.05). The chlorhexidine mouthwash produced the greatest mean growth inhibition of S. sanguinis and S. mutans compared to all other mouthrinses tested (p < 0.01). The minimum concentrations at which inhibition against S. mutans could be detected were chlorhexidine gluconate at 0.005% (wt/vol), cetylpyridinium chloride 0.01% (wt/ vol), povidone iodine 10% (wt/vol) and sodium hypochlorite 0.5% (vol/vol). Chlorhexidine (0.01%), cetylpyridinium chloride (0.01%), povidone iodine (10%) and sodium hypochlorite (0.5%) are effective at inhibiting the growth of S. mutans, S. sanguinis and L. acidophilus. © 2015 Australian Dental Association.

  13. Comparative effect of photodynamic therapy on separated or mixed cultures of Streptococcus mutans and Streptococcus sanguinis.

    PubMed

    Pérez-Laguna, Vanesa; Pérez-Artiaga, Luna; Lampaya-Pérez, Verónica; López, Santiago Camacho; García-Luque, Isabel; Revillo, María José; Nonell, Santi; Gilaberte, Yolanda; Rezusta, Antonio

    2017-09-01

    Antimicrobial photodynamic therapy (aPDT) has shown to exert a bactericidal effect against Streptococcus sanguinis and Streptococcus mutans. However, this efficacy has been reported for either type of bacteria separately. Bacterial suspensions of both strains, separately or together, were treated with concentrations of methylene blue (MB) and rose bengal (RB). Suspensions were irradiated with a light-emitting diode lamp (λ center at 625nm for MB and λ center at 515nm for RB) using a fluence of 18J/cm(2). RB-aPDT at concentrations of 0.16-0.62 and 0.16-0.31μg/mL, and MB-aPDT at concentrations of 0.62-1.25 and 0.31-1.25μg/mL inhibited the growth of S. mutans and S. sanguinis respectively by 6 log10. In suspensions of both strains together, the same 6 log10 reduction in bacterial growth was achieved using the same concentrations of each photosensiziser. In conclusion, RB-aPDT and MB-aPDT appear to exert the same bactericidal effect against suspensions of S. sanguinis and S. mutans either for single strain treatment or for samples constituted by both bacteria mixed together. RB shows to be slightly more efficient than MB. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. In Vitro Effect of Zingiber officinale Extract on Growth of Streptococcus mutans and Streptococcus sanguinis.

    PubMed

    Azizi, Arash; Aghayan, Shabnam; Zaker, Saeed; Shakeri, Mahdieh; Entezari, Navid; Lawaf, Shirin

    2015-01-01

    Background and Objectives. Tooth decay is an infectious disease of microbial origin. Considering the increasing prevalence of antibiotic resistance due to their overuse and also their side effects, medicinal plants are now considered for use against bacterial infections. This study aimed to assess the effects of different concentrations of Zingiber officinale extract on proliferation of Streptococcus mutans and Streptococcus sanguinis in vitro. Materials and Methods. In this experimental study, serial dilutions of the extract were prepared in two sets of 10 test tubes for each bacterium (total of 20). Standard amounts of bacterial suspension were added; 100ƛ of each tube was cultured on prepared solid agar plates and incubated at 37°C for 24 hours. Serial dilutions of the extract were prepared in another 20 tubes and 100ƛ of each tube was added to blood agar culture medium while being prepared. The mixture was transferred to the plates. The bacteria were inoculated on plates and incubated as described. Results. The minimum inhibitory concentration (MIC) was 0.02 mg/mL for S. mutans and 0.3 mg/mL for S. sanguinis. The minimum bactericidal concentration (MBC) was 0.04 mg for S. mutans and 0.6 mg for S. sanguinis. Conclusion. Zingiber officinale extract has significant antibacterial activity against S. mutans and S. sanguinis cariogenic microorganisms.

  15. Parallel Evolution of Streptococcus pneumoniae and Streptococcus mitis to Pathogenic and Mutualistic Lifestyles

    PubMed Central

    Riley, David R.; Jensen, Anders; Brüggemann, Holger; Tettelin, Hervé

    2014-01-01

    ABSTRACT The bacterium Streptococcus pneumoniae is one of the leading causes of fatal infections affecting humans. Intriguingly, phylogenetic analysis shows that the species constitutes one evolutionary lineage in a cluster of the otherwise commensal Streptococcus mitis strains, with which humans live in harmony. In a comparative analysis of 35 genomes, including phylogenetic analyses of all predicted genes, we have shown that the pathogenic pneumococcus has evolved into a master of genomic flexibility while lineages that evolved into the nonpathogenic S. mitis secured harmonious coexistence with their host by stabilizing an approximately 15%-reduced genome devoid of many virulence genes. Our data further provide evidence that interspecies gene transfer between S. pneumoniae and S. mitis occurs in a unidirectional manner, i.e., from S. mitis to S. pneumoniae. Import of genes from S. mitis and other mitis, anginosus, and salivarius group streptococci ensured allelic replacements and antigenic diversification and has been driving the evolution of the remarkable structural diversity of capsular polysaccharides of S. pneumoniae. Our study explains how the unique structural diversity of the pneumococcal capsule emerged and conceivably will continue to increase and reveals a striking example of the fragile border between the commensal and pathogenic lifestyles. While genomic plasticity enabling quick adaptation to environmental stress is a necessity for the pathogenic streptococci, the commensal lifestyle benefits from stability. PMID:25053789

  16. In Vitro Effect of Zingiber officinale Extract on Growth of Streptococcus mutans and Streptococcus sanguinis

    PubMed Central

    Azizi, Arash; Aghayan, Shabnam; Zaker, Saeed; Shakeri, Mahdieh; Entezari, Navid; Lawaf, Shirin

    2015-01-01

    Background and Objectives. Tooth decay is an infectious disease of microbial origin. Considering the increasing prevalence of antibiotic resistance due to their overuse and also their side effects, medicinal plants are now considered for use against bacterial infections. This study aimed to assess the effects of different concentrations of Zingiber officinale extract on proliferation of Streptococcus mutans and Streptococcus sanguinis in vitro. Materials and Methods. In this experimental study, serial dilutions of the extract were prepared in two sets of 10 test tubes for each bacterium (total of 20). Standard amounts of bacterial suspension were added; 100ƛ of each tube was cultured on prepared solid agar plates and incubated at 37°C for 24 hours. Serial dilutions of the extract were prepared in another 20 tubes and 100ƛ of each tube was added to blood agar culture medium while being prepared. The mixture was transferred to the plates. The bacteria were inoculated on plates and incubated as described. Results. The minimum inhibitory concentration (MIC) was 0.02 mg/mL for S. mutans and 0.3 mg/mL for S. sanguinis. The minimum bactericidal concentration (MBC) was 0.04 mg for S. mutans and 0.6 mg for S. sanguinis. Conclusion. Zingiber officinale extract has significant antibacterial activity against S. mutans and S. sanguinis cariogenic microorganisms. PMID:26347778

  17. The Importance of TLR2 and Macrophages in Modulating a Humoral Response after Encountering Streptococcus pneumoniae

    DTIC Science & Technology

    2008-03-26

    receptor in recognizing important moieties on gram -positive bacteria including peptidoglycan , lipoproteins and lipoteichoic acid (67-71). Originally TLR2...Pathogen associated molecular patterns PerM-Peritoneal macrophage PC-phosphorylcholine PGN- Peptidoglycan Pn-Streptococcus pneumoniae Pn14-Streptococcus...pathogenesis Streptococcus pneumoniae (Pn), also referred to as pneumococcus, is a gram - positive anaerobic bacterium and an important cause of many

  18. Streptococcal Toxic Shock Syndrome Caused by Group G Streptococcus, United Kingdom

    PubMed Central

    Morgan, Marina

    2017-01-01

    We describe successful management of 3 patients with streptococcal toxic shock syndrome (STSS) attributable to group G Streptococcus infection. This small series supports recognition of group G Streptococcus in the etiology of STSS. We propose intravenous immunoglobulin be used in treatment as it is for STSS caused by group A Streptococcus. PMID:27983491

  19. 77 FR 26014 - Prospective Grant of Exclusive License: P4 Peptide From Streptococcus Pneumoniae

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-02

    ... Prospective Grant of Exclusive License: P4 Peptide From Streptococcus Pneumoniae AGENCY: Technology Transfer... ``Functional Epitopes of Streptococcus Pneumoniae PsaA Antigen and Uses Thereof,'' filed 7/ 18/2008, claiming... Streptococcus pneumoniae. This technology also includes an antibody that can bind to the epitopes of the...

  20. A Fishy Tale: a Man with Empyema Caused by Streptococcus halichoeri

    PubMed Central

    Chan, Douglas

    2014-01-01

    In 2004, veterinary laboratories in the United Kingdom reported a novel Lancefield group B streptococcus, Streptococcus halichoeri, in seals. We report a case of Streptococcus halichoeri causing postoperative empyema in a patient. A search of the literature revealed that this is the first case of S. halichoeri ever reported in humans. PMID:24478513

  1. The streptococcal inhibitor of complement (SIC) protects Streptococcus pyogenes from bacteriocin-like inhibitory substance (BLIS) from Streptococcus salivarius.

    PubMed

    Minami, Masaaki; Ohmori, Daisuke; Tatsuno, Ichiro; Isaka, Masanori; Kawamura, Yoshiaki; Ohta, Michio; Hasegawa, Tadao

    2009-09-01

    Streptococcus salivarius inhibits the growth of Streptococcus pyogenes in vitro. Streptococcus pyogenes has various virulence factors, including the streptococcus inhibitor of complement (SIC). Although SIC inhibits the activity of the peptides LL-37 and NAP1, the relationship between SIC and the bacteriocin-like inhibitory substance (BLIS) has not been elucidated. Here, we evaluated whether S. salivarius BLIS affects S. pyogenes SIC. We created three deltasic mutant strains from three S. pyogenes strains and performed deferred antagonism assays. The test strains were BLIS-positive S. salivarius JCM5707 and BLIS-negative S. salivarius NCU12. Deferred antagonism assays with JCM5707 showed that the inhibitory zones in the three deltasic mutant strains were wider than those in the three wild-type strains. Streptococcus pyogenes was cultured in BLIS-containing broth and the change in SIC in the supernatant was assessed by two-dimensional gel electrophoresis (2-DE). The 2-DE analysis of S. pyogenes exoproteins with the JCM5707 supernatant showed reduced SIC compared with those without the JCM5707 supernatant. Changes in sic mRNA levels affected by S. salivarius BLIS were evaluated by a reverse transcriptase-PCR. The sic mRNA level was affected more by the BLIS-positive S. salivarius than by the BLIS-negative strain. Our result indicates that SIC plays a role in the inhibition of S. salivarius BLIS.

  2. Group B streptococcus endocarditis associated with multiple pulmonary septic emboli.

    PubMed

    Teran, Carlos G; Antezana, Ariel O; Salvani, Jerome; Abaitey, Deborah

    2011-03-29

    Endocarditis is a rare presentation of group B streptococcal infection. Its association with pulmonary septic embolism was only barely studied and limited data is available up to date. Multiple septic emboli is a common complication of bacterial endocarditis, but only a few cases have been documented in relation to group B streptococcus. We present the case of an 87 year old female patient with multiple underlying conditions that predisposed the development of bacterial endocarditis secondary to group B streptococcus and subsequently multiple pulmonary septic emboli. The patient was treated with ceftriaxone and azythromycin with good response and complete recovery without any further complications. In the event of a diagnosed case of group B streptococcus endocarditis, there should be a low threshold for the suspicion of septic pulmonary emboli especially in cases with right valves involvement.

  3. Streptococcus agalactiae Native Valve Endocarditis: Uncommon Presentation of Multiple Myeloma.

    PubMed

    Pinho Oliveira, Ana; Delgado, Anne; Martins, Cláudia; Gama, Pedro

    2016-08-01

    Adults with chronic immunosuppressive conditions are at an increased risk for Streptococcus agalactiae endocarditis, which is typically characterized by acute onset, presence of large vegetations, rapid valvular destruction and frequent complications. We report a rare case of a 74 years old man presenting with fever, renal infarction, ischemic stroke and uveitis. Infective endocarditis was diagnosed and Streptococcus agalactiae was isolated in blood cultures. A multiple myeloma Ig G-K was also diagnosed. The infective endocarditis was successfully treated with a course of benzylpenicillin and gentamicin. The authors highlight the severity of vascular embolic disease present in this case and the diagnostic challenge. They also intend to remind about the association between Streptococcus agalactiae endocarditis and chronic diseases, despite its low reported prevalence.

  4. Chlorophyll mediated photodynamic inactivation of blue laser on Streptococcus mutans

    NASA Astrophysics Data System (ADS)

    Astuti, Suryani Dyah; Zaidan, A.; Setiawati, Ernie Maduratna; Suhariningsih

    2016-03-01

    Photodynamic inactivation is an inactivation method in microbial pathogens that utilize light and photosensitizer. This study was conducted to investigate photodynamic inactivation effects of low intensity laser exposure with various dose energy on Streptococcus mutans bacteria. The photodynamic inactivation was achieved with the addition of chlorophyll as photosensitizers. To determine the survival percentage of Streptococcus mutans bacteria after laser exposure, the total plate count method was used. For this study, the wavelength of the laser is 405 nm and variables of energy doses are 1.44, 2.87, 4.31, 5.74, 7.18, and 8.61 in J/cm2. The results show that exposure to laser with energy dose of 7.18 J/cm2 has the best photodynamic inactivation with a decrease of 78% in Streptococcus

  5. Thalamic abscess caused by a rare pathogen: streptococcus constellatus

    PubMed Central

    Şenol, Özgür; Süslü, Hikmet Turan; Tatarlı, Necati; Tiryaki, Mehmet; Güçlü, Bülent

    2016-01-01

    Streptococcus constellatus is a microorganism that lives commensally in the oropharyngeal region, urogenital region, and intestinal tract. However, it can cause infection in patients with certain predisposing factors. Rarely, this microorganism can cause a brain abscess. Thalamic localization of brain abscesses is much rarer than abscesses in other locations of the brain. Brain abscess caused by streptococcus constellatus are very rarely been reported in the literature. We present a rare case of a left-sided thalamic abscess caused by streptococcus constellatus in a 25-year-old male patient who was injured by shrapnel pieces in the head and who was malnourished. The patient was successfully treated by stereotactic aspiration and antibiotherapy. PMID:27800109

  6. [Streptococcus intermedius: a rare cause of brain abscess in children].

    PubMed

    Jouhadi, Z; Sadiki, H; Hafid, I; Najib, J

    2013-03-01

    Streptococcus intermedius is a member of the Streptococcus anginosus group, also known as the Streptococcus milleri group. Although this is a commensal agent of the mouth and upper airways, it has been recognized as an important pathogen in the formation of abscesses. However, it has rarely been involved in the formation of brain abscess in children. We report 4 pediatric cases of brain abscess caused by S. intermedius. Three boys and 1 girl, all aged over 2 years, were admitted for a febrile meningeal syndrome and seizures, caused by a S. intermedius brain abscess. Diagnosis was obtained by brain imaging combined with culture of cerebrospinal fluid. The outcome was favorable after antibiotic therapy and abscess puncture. S. intermedius should be considered a potential pathogen involved in the development of brain abscess in children.

  7. Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

    SciTech Connect

    Nelson, O.D.

    1997-09-04

    This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage.

  8. Fluoroquinolone Resistance among Clonal Complex 1 Group B Streptococcus Strains

    PubMed Central

    Teatero, Sarah; Patel, Samir N.

    2016-01-01

    Fluoroquinolone resistance in group B Streptococcus is increasingly being reported worldwide. Here, we correlated fluoroquinolone resistance with mutations in gyrA, gyrB, parC, and parE genes, identified by mining whole-genome sequencing (WGS) data of 190 clonal complex 1 group B Streptococcus strains recovered from patients with invasive diseases in North America. We report a high prevalence of fluoroquinolone resistance (12%) among GBS strains in our collection. Our approach is the first step towards accurate prediction of fluoroquinolone resistance from WGS data in this opportunistic pathogen. PMID:27559344

  9. Genome sequence of Streptococcus mutans bacteriophage M102.

    PubMed

    van der Ploeg, Jan R

    2007-10-01

    Bacteriophage M102 is a lytic phage specific for serotype c strains of Streptococcus mutans, a causative agent of dental caries. In this study, the complete genome sequence of M102 was determined. The genome is 31,147 bp in size and contains 41 ORFs. Most of the ORFs encoding putative phage structural proteins show similarity to those from bacteriophages from Streptococcus thermophilus. Bioinformatic analysis indicated that the M102 genome contains an unusual lysis cassette, which encodes a holin and two lytic enzymes.

  10. Molecular Epidemiology and Genomics of Group A Streptococcus

    PubMed Central

    Bessen, Debra E.; McShan, W. Michael; Nguyen, Scott V.; Shetty, Amol; Agrawal, Sonia; Tettelin, Hervé

    2014-01-01

    Streptococcus pyogenes (group A streptococcus; GAS) is a strict human pathogen with a very high prevalence worldwide. This review highlights the genetic organization of the species and the important ecological considerations that impact its evolution. Recent advances are presented on the topics of molecular epidemiology, population biology, molecular basis for genetic change, genome structure and genetic flux, phylogenomics and closely related streptococcal species, and the long- and short-term evolution of GAS. The application of whole genome sequence data to addressing key biological questions is discussed. PMID:25460818

  11. Horizontal gene transfer and recombination in Streptococcus dysgalactiae subsp. equisimilis

    PubMed Central

    McNeilly, Celia L.; McMillan, David J.

    2014-01-01

    Streptococcus dysgalactiae subsp. equisimilis (SDSE) is a human pathogen that colonizes the skin or throat, and causes a range of diseases from relatively benign pharyngitis to potentially fatal invasive diseases. While not as virulent as the close relative Streptococcus pyogenes the two share a number of virulence factors and are known to coexist in a human host. Both pre- and post-genomic studies have revealed that horizontal gene transfer (HGT) and recombination occurs between these two organisms and plays a major role in shaping the population structure of SDSE. This review summarizes our current knowledge of HGT and recombination in the evolution of SDSE. PMID:25566202

  12. Thermoregulation of Capsule Production by Streptococcus pyogenes

    PubMed Central

    Kang, Song Ok; Wright, Jordan O.; Tesorero, Rafael A.; Lee, Hyunwoo; Beall, Bernard; Cho, Kyu Hong

    2012-01-01

    The capsule of Streptococcus pyogenes serves as an adhesin as well as an anti-phagocytic factor by binding to CD44 on keratinocytes of the pharyngeal mucosa and the skin, the main entry sites of the pathogen. We discovered that S. pyogenes HSC5 and MGAS315 strains are further thermoregulated for capsule production at a post-transcriptional level in addition to the transcriptional regulation by the CovRS two-component regulatory system. When the transcription of the hasABC capsular biosynthetic locus was de-repressed through mutation of the covRS system, the two strains, which have been used for pathogenesis studies in the laboratory, exhibited markedly increased capsule production at sub-body temperature. Employing transposon mutagenesis, we found that CvfA, a previously identified membrane-associated endoribonuclease, is required for the thermoregulation of capsule synthesis. The mutation of the cvfA gene conferred increased capsule production regardless of temperature. However, the amount of the capsule transcript was not changed by the mutation, indicating that a post-transcriptional regulator mediates between CvfA and thermoregulated capsule production. When we tested naturally occurring invasive mucoid strains, a high percentage (11/53, 21%) of the strains exhibited thermoregulated capsule production. As expected, the mucoid phenotype of these strains at sub-body temperature was due to mutations within the chromosomal covRS genes. Capsule thermoregulation that exhibits high capsule production at lower temperatures that occur on the skin or mucosal surface potentially confers better capability of adhesion and invasion when S. pyogenes penetrates the epithelial surface. PMID:22615992

  13. Functional amyloid formation by Streptococcus mutans

    PubMed Central

    Oli, M. W.; Otoo, H. N.; Crowley, P. J.; Heim, K. P.; Nascimento, M. M.; Ramsook, C. B.; Lipke, P. N.

    2012-01-01

    Dental caries is a common infectious disease associated with acidogenic and aciduric bacteria, including Streptococcus mutans. Organisms that cause cavities form recalcitrant biofilms, generate acids from dietary sugars and tolerate acid end products. It has recently been recognized that micro-organisms can produce functional amyloids that are integral to biofilm development. We now show that the S. mutans cell-surface-localized adhesin P1 (antigen I/II, PAc) is an amyloid-forming protein. This conclusion is based on the defining properties of amyloids, including binding by the amyloidophilic dyes Congo red (CR) and Thioflavin T (ThT), visualization of amyloid fibres by transmission electron microscopy and the green birefringent properties of CR-stained protein aggregates when viewed under cross-polarized light. We provide evidence that amyloid is present in human dental plaque and is produced by both laboratory strains and clinical isolates of S. mutans. We provide further evidence that amyloid formation is not limited to P1, since bacterial colonies without this adhesin demonstrate residual green birefringence. However, S. mutans lacking sortase, the transpeptidase enzyme that mediates the covalent linkage of its substrates to the cell-wall peptidoglycan, including P1 and five other proteins, is not birefringent when stained with CR and does not form biofilms. Biofilm formation is inhibited when S. mutans is cultured in the presence of known inhibitors of amyloid fibrillization, including CR, Thioflavin S and epigallocatechin-3-gallate, which also inhibited ThT uptake by S. mutans extracellular proteins. Taken together, these results indicate that S. mutans is an amyloid-forming organism and suggest that amyloidogenesis contributes to biofilm formation by this oral microbe. PMID:23082034

  14. Heteroresistance to penicillin in Streptococcus pneumoniae.

    PubMed

    Morand, Brigitte; Mühlemann, Kathrin

    2007-08-28

    Heteroresistance to beta-lactam antibiotics has been mainly described for staphylococci, for which it complicates diagnostic procedures and therapeutic success. This study investigated whether heteroresistance to penicillin exists in Streptococcus pneumoniae. Population analysis profile (PAP) showed the presence of subpopulations with higher penicillin resistance in four of nine clinical pneumococcal strains obtained from a local surveillance program (representing the multiresistant clones ST179, ST276, and ST344) and in seven of 16 reference strains (representing the international clones Spain(23F)-1, Spain(9V)-3, Spain(14)-5, Hungary(19A)-6, South Africa(19A)-13, Taiwan(23F)-15, and Finland(6B)-12). Heteroresistant strains had penicillin minimal inhibitory concentrations (MICs) (for the majority of cells) in the intermediate- to high-level range (0.19-2.0 mug/ml). PAP curves suggested the presence of subpopulations also for the highly penicillin-resistant strains Taiwan(19F)-14, Poland(23F)-16, CSR(19A)-11, and CSR(14)-10. PAP of bacterial subpopulations with higher penicillin resistance showed a shift toward higher penicillin-resistance levels, which reverted upon multiple passages on antibiotic-free media. Convergence to a homotypic resistance phenotype did not occur. Comparison of two strains of clone ST179 showed a correlation between the heteroresistant phenotype and a higher-penicillin MIC and a greater number of altered penicillin-binding proteins (PBP1a, -2b, and -2x), respectively. Therefore, heteroresistance to penicillin occurs in international multiresistant clones of S. pneumoniae. Pneumococci may use heteroresistance to penicillin as a tool during their evolution to high penicillin resistance, because it gives the bacteria an opportunity to explore growth in the presence of antibiotics before acquisition of resistance genes.

  15. Thermoregulation of capsule production by Streptococcus pyogenes.

    PubMed

    Kang, Song Ok; Wright, Jordan O; Tesorero, Rafael A; Lee, Hyunwoo; Beall, Bernard; Cho, Kyu Hong

    2012-01-01

    The capsule of Streptococcus pyogenes serves as an adhesin as well as an anti-phagocytic factor by binding to CD44 on keratinocytes of the pharyngeal mucosa and the skin, the main entry sites of the pathogen. We discovered that S. pyogenes HSC5 and MGAS315 strains are further thermoregulated for capsule production at a post-transcriptional level in addition to the transcriptional regulation by the CovRS two-component regulatory system. When the transcription of the hasABC capsular biosynthetic locus was de-repressed through mutation of the covRS system, the two strains, which have been used for pathogenesis studies in the laboratory, exhibited markedly increased capsule production at sub-body temperature. Employing transposon mutagenesis, we found that CvfA, a previously identified membrane-associated endoribonuclease, is required for the thermoregulation of capsule synthesis. The mutation of the cvfA gene conferred increased capsule production regardless of temperature. However, the amount of the capsule transcript was not changed by the mutation, indicating that a post-transcriptional regulator mediates between CvfA and thermoregulated capsule production. When we tested naturally occurring invasive mucoid strains, a high percentage (11/53, 21%) of the strains exhibited thermoregulated capsule production. As expected, the mucoid phenotype of these strains at sub-body temperature was due to mutations within the chromosomal covRS genes. Capsule thermoregulation that exhibits high capsule production at lower temperatures that occur on the skin or mucosal surface potentially confers better capability of adhesion and invasion when S. pyogenes penetrates the epithelial surface.

  16. Nonencapsulated Streptococcus pneumoniae: Emergence and Pathogenesis

    PubMed Central

    Keller, Lance E.; Robinson, D. Ashley

    2016-01-01

    ABSTRACT While significant protection from pneumococcal disease has been achieved by the use of polysaccharide and polysaccharide-protein conjugate vaccines, capsule-independent protection has been limited by serotype replacement along with disease caused by nonencapsulated Streptococcus pneumoniae (NESp). NESp strains compose approximately 3% to 19% of asymptomatic carriage isolates and harbor multiple antibiotic resistance genes. Surface proteins unique to NESp enhance colonization and virulence despite the lack of a capsule even though the capsule has been thought to be required for pneumococcal pathogenesis. Genes for pneumococcal surface proteins replace the capsular polysaccharide (cps) locus in some NESp isolates, and these proteins aid in pneumococcal colonization and otitis media (OM). NESp strains have been isolated from patients with invasive and noninvasive pneumococcal disease, but noninvasive diseases, specifically, conjunctivitis (85%) and OM (8%), are of higher prevalence. Conjunctival strains are commonly of the so-called classical NESp lineages defined by multilocus sequence types (STs) ST344 and ST448, while sporadic NESp lineages such as ST1106 are more commonly isolated from patients with other diseases. Interestingly, sporadic lineages have significantly higher rates of recombination than classical lineages. Higher rates of recombination can lead to increased acquisition of antibiotic resistance and virulence factors, increasing the risk of disease and hindering treatment. NESp strains are a significant proportion of the pneumococcal population, can cause disease, and may be increasing in prevalence in the population due to effects on the pneumococcal niche caused by pneumococcal vaccines. Current vaccines are ineffective against NESp, and further research is necessary to develop vaccines effective against both encapsulated and nonencapsulated pneumococci. PMID:27006456

  17. Capsular Polysaccharide Expression in Commensal Streptococcus Species: Genetic and Antigenic Similarities to Streptococcus pneumoniae.

    PubMed

    Skov Sørensen, Uffe B; Yao, Kaihu; Yang, Yonghong; Tettelin, Hervé; Kilian, Mogens

    2016-11-15

    Expression of a capsular polysaccharide is considered a hallmark of most invasive species of bacteria, including Streptococcus pneumoniae, in which the capsule is among the principal virulence factors and is the basis for successful vaccines. Consequently, it was previously assumed that capsule production distinguishes S. pneumoniae from closely related commensals of the mitis group streptococci. Based on antigenic and genetic analyses of 187 mitis group streptococci, including 90 recognized serotypes of S. pneumoniae, we demonstrated capsule production by the Wzy/Wzx pathway in 74% of 66 S. mitis strains and in virtually all tested strains of S. oralis (subspecies oralis, dentisani, and tigurinus) and S. infantis Additional analyses of genomes of S. cristatus, S. parasanguinis, S. australis, S. sanguinis, S. gordonii, S. anginosus, S. intermedius, and S. constellatus revealed complete capsular biosynthesis (cps) loci in all strains tested. Truncated cps loci were detected in three strains of S. pseudopneumoniae, in 26% of S. mitis strains, and in a single S. oralis strain. The level of sequence identities of cps locus genes confirmed that the structural polymorphism of capsular polysaccharides in S. pneumoniae evolved by import of cps fragments from commensal Streptococcus species, resulting in a mosaic of genes of different origins. The demonstrated antigenic identity of at least eight of the numerous capsular polysaccharide structures expressed by commensal streptococci with recognized serotypes of S. pneumoniae raises concerns about potential misidentifications in addition to important questions concerning the consequences for vaccination and host-parasite relationships both for the commensals and for the pathogen. Expression of a capsular polysaccharide is among the principal virulence factors of Streptococcus pneumoniae and is the basis for successful vaccines against infections caused by this important pathogen. Contrasting with previous

  18. The novel species Streptococcus tigurinus and its association with oral infection.

    PubMed

    Zbinden, Andrea; Bostanci, Nagihan; Belibasakis, Georgios N

    2015-01-01

    Streptococcus tigurinus is a novel species of viridans streptococci, shown to cause severe invasive infections such as infective endocarditis, spondylodiscitis and meningitis. S. tigurinus belongs to the Streptococcus mitis group and is most closely related to Streptococcus mitis, Streptococcus oralis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae and Streptococcus infantis. The presence of S. tigurinus in the human oral cavity has been documented, including in patients with periodontal disease. This review addresses the available scientific knowledge on S. tigurinus and its association with closely related streptococci, and discusses its putative involvement in common oral infections. While there is as yet no strong evidence on the involvement of S. tigurinus with oral infections, its presence in the oral cavity and its association with endocarditis warrants special attention for a link between oral and systemic infection.

  19. The novel species Streptococcus tigurinus and its association with oral infection

    PubMed Central

    Zbinden, Andrea; Bostanci, Nagihan; Belibasakis, Georgios N

    2015-01-01

    Streptococcus tigurinus is a novel species of viridans streptococci, shown to cause severe invasive infections such as infective endocarditis, spondylodiscitis and meningitis. S. tigurinus belongs to the Streptococcus mitis group and is most closely related to Streptococcus mitis, Streptococcus oralis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae and Streptococcus infantis. The presence of S. tigurinus in the human oral cavity has been documented, including in patients with periodontal disease. This review addresses the available scientific knowledge on S. tigurinus and its association with closely related streptococci, and discusses its putative involvement in common oral infections. While there is as yet no strong evidence on the involvement of S. tigurinus with oral infections, its presence in the oral cavity and its association with endocarditis warrants special attention for a link between oral and systemic infection. PMID:25483862

  20. Molecular characterization of invasive Streptococcus dysgalactiae subsp. equisimilis. Multicenter study: Argentina 2011-2012.

    PubMed

    Traverso, Fernando; Blanco, Alejandra; Villalón, Pilar; Beratz, Noelia; Sáez Nieto, Juan Antonio; Lopardo, Horacio

    Streptococcus dysgalactiae subsp. equisimilis (SDSE) has virulence factors similar to those of Streptococcus pyogenes. Therefore, it causes pharyngitis and severe infections indistinguishable from those caused by the classic pathogen. The objectives of this study were: to know the prevalence of SDSE invasive infections in Argentina, to study the genetic diversity, to determine the presence of virulence genes, to study antibiotic susceptibility and to detect antibiotic resistance genes. Conventional methods of identification were used. Antibiotic susceptibility was determined by the disk diffusion and the agar dilution methods and the E-test. Twenty eight centers from 16 Argentinean cities participated in the study. Twenty three isolates (16 group G and 7 group C) were obtained between July 1 2011 and June 30 2012. Two adult patients died (8.7%). Most of the isolates were recovered from blood (60.9%). All isolates carried speJ and ssa genes. stG62647, stG653 and stG840 were the most frequent emm types. Nineteen different PFGE patterns were detected. All isolates were susceptible to penicillin and levofloxacin, 6 (26.1%) showed resistance or reduced susceptibility to erythromycin [1 mef(A), 3 erm(TR), 1 mef(A)+erm(TR) and 1 erm(TR)+erm(B)] and 7 (30.4%) were resistant or exhibited reduced susceptibility to tetracycline [2 tet(M), 5 tet(M)+tet(O)]. The prevalence in Argentina was of at least 23 invasive infections by SDSE. A wide genetic diversity was observed. All isolates carried speJ and ssa genes. Similarly to other studies, macrolide resistance (26.1%) was mainly associated to the MLSB phenotype. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Inhibition of Streptococcus mutans biofilm formation by Streptococcus salivarius FruA.

    PubMed

    Ogawa, Ayako; Furukawa, Soichi; Fujita, Shuhei; Mitobe, Jiro; Kawarai, Taketo; Narisawa, Naoki; Sekizuka, Tsuyoshi; Kuroda, Makoto; Ochiai, Kuniyasu; Ogihara, Hirokazu; Kosono, Saori; Yoneda, Saori; Watanabe, Haruo; Morinaga, Yasushi; Uematsu, Hiroshi; Senpuku, Hidenobu

    2011-03-01

    The oral microbial flora consists of many beneficial species of bacteria that are associated with a healthy condition and control the progression of oral disease. Cooperative interactions between oral streptococci and the pathogens play important roles in the development of dental biofilms in the oral cavity. To determine the roles of oral streptococci in multispecies biofilm development and the effects of the streptococci in biofilm formation, the active substances inhibiting Streptococcus mutans biofilm formation were purified from Streptococcus salivarius ATCC 9759 and HT9R culture supernatants using ion exchange and gel filtration chromatography. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry analysis was performed, and the results were compared to databases. The S. salivarius HT9R genome sequence was determined and used to indentify candidate proteins for inhibition. The candidates inhibiting biofilms were identified as S. salivarius fructosyltransferase (FTF) and exo-beta-d-fructosidase (FruA). The activity of the inhibitors was elevated in the presence of sucrose, and the inhibitory effects were dependent on the sucrose concentration in the biofilm formation assay medium. Purified and commercial FruA from Aspergillus niger (31.6% identity and 59.6% similarity to the amino acid sequence of FruA from S. salivarius HT9R) completely inhibited S. mutans GS-5 biofilm formation on saliva-coated polystyrene and hydroxyapatite surfaces. Inhibition was induced by decreasing polysaccharide production, which is dependent on sucrose digestion rather than fructan digestion. The data indicate that S. salivarius produces large quantities of FruA and that FruA alone may play an important role in multispecies microbial interactions for sucrose-dependent biofilm formation in the oral cavity.

  2. Inhibition of Streptococcus mutans Biofilm Formation by Streptococcus salivarius FruA▿

    PubMed Central

    Ogawa, Ayako; Furukawa, Soichi; Fujita, Shuhei; Mitobe, Jiro; Kawarai, Taketo; Narisawa, Naoki; Sekizuka, Tsuyoshi; Kuroda, Makoto; Ochiai, Kuniyasu; Ogihara, Hirokazu; Kosono, Saori; Yoneda, Saori; Watanabe, Haruo; Morinaga, Yasushi; Uematsu, Hiroshi; Senpuku, Hidenobu

    2011-01-01

    The oral microbial flora consists of many beneficial species of bacteria that are associated with a healthy condition and control the progression of oral disease. Cooperative interactions between oral streptococci and the pathogens play important roles in the development of dental biofilms in the oral cavity. To determine the roles of oral streptococci in multispecies biofilm development and the effects of the streptococci in biofilm formation, the active substances inhibiting Streptococcus mutans biofilm formation were purified from Streptococcus salivarius ATCC 9759 and HT9R culture supernatants using ion exchange and gel filtration chromatography. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry analysis was performed, and the results were compared to databases. The S. salivarius HT9R genome sequence was determined and used to indentify candidate proteins for inhibition. The candidates inhibiting biofilms were identified as S. salivarius fructosyltransferase (FTF) and exo-beta-d-fructosidase (FruA). The activity of the inhibitors was elevated in the presence of sucrose, and the inhibitory effects were dependent on the sucrose concentration in the biofilm formation assay medium. Purified and commercial FruA from Aspergillus niger (31.6% identity and 59.6% similarity to the amino acid sequence of FruA from S. salivarius HT9R) completely inhibited S. mutans GS-5 biofilm formation on saliva-coated polystyrene and hydroxyapatite surfaces. Inhibition was induced by decreasing polysaccharide production, which is dependent on sucrose digestion rather than fructan digestion. The data indicate that S. salivarius produces large quantities of FruA and that FruA alone may play an important role in multispecies microbial interactions for sucrose-dependent biofilm formation in the oral cavity. PMID:21239559

  3. Isolation and characterization of unsaturated fatty acid auxotrophs of Streptococcus pneumoniae and Streptococcus mutans.

    PubMed

    Altabe, Silvia; Lopez, Paloma; de Mendoza, Diego

    2007-11-01

    Unsaturated fatty acid (UFA) biosynthesis is essential for the maintenance of membrane structure and function in many groups of anaerobic bacteria. Like Escherichia coli, the human pathogen Streptococcus pneumoniae produces straight-chain saturated fatty acids (SFA) and monounsaturated fatty acids. In E. coli UFA synthesis requires the action of two gene products, the essential isomerase/dehydratase encoded by fabA and an elongation condensing enzyme encoded by fabB. S. pneumoniae lacks both genes and instead employs a single enzyme with only an isomerase function encoded by the fabM gene. In this paper we report the construction and characterization of an S. pneumoniae 708 fabM mutant. This mutant failed to grow in complex medium, and the defect was overcome by addition of UFAs to the growth medium. S. pneumoniae fabM mutants did not produce detectable levels of monounsaturated fatty acids as determined by gas chromatography-mass spectrometry and thin-layer chromatography analysis of the radiolabeled phospholipids. We also demonstrate that a fabM null mutant of the cariogenic organism Streptococcus mutants is a UFA auxotroph, indicating that FabM is the only enzyme involved in the control of membrane fluidity in streptococci. Finally we report that the fabN gene of Enterococcus faecalis, coding for a dehydratase/isomerase, complements the growth of S. pneumoniae fabM mutants. Taken together, these results suggest that FabM is a potential target for chemotherapeutic agents against streptococci and that S. pneumoniae UFA auxotrophs could help identify novel genes encoding enzymes involved in UFA biosynthesis.

  4. Capsular Polysaccharide Expression in Commensal Streptococcus Species: Genetic and Antigenic Similarities to Streptococcus pneumoniae

    PubMed Central

    Skov Sørensen, Uffe B.; Yao, Kaihu; Yang, Yonghong; Tettelin, Hervé

    2016-01-01

    ABSTRACT Expression of a capsular polysaccharide is considered a hallmark of most invasive species of bacteria, including Streptococcus pneumoniae, in which the capsule is among the principal virulence factors and is the basis for successful vaccines. Consequently, it was previously assumed that capsule production distinguishes S. pneumoniae from closely related commensals of the mitis group streptococci. Based on antigenic and genetic analyses of 187 mitis group streptococci, including 90 recognized serotypes of S. pneumoniae, we demonstrated capsule production by the Wzy/Wzx pathway in 74% of 66 S. mitis strains and in virtually all tested strains of S. oralis (subspecies oralis, dentisani, and tigurinus) and S. infantis. Additional analyses of genomes of S. cristatus, S. parasanguinis, S. australis, S. sanguinis, S. gordonii, S. anginosus, S. intermedius, and S. constellatus revealed complete capsular biosynthesis (cps) loci in all strains tested. Truncated cps loci were detected in three strains of S. pseudopneumoniae, in 26% of S. mitis strains, and in a single S. oralis strain. The level of sequence identities of cps locus genes confirmed that the structural polymorphism of capsular polysaccharides in S. pneumoniae evolved by import of cps fragments from commensal Streptococcus species, resulting in a mosaic of genes of different origins. The demonstrated antigenic identity of at least eight of the numerous capsular polysaccharide structures expressed by commensal streptococci with recognized serotypes of S. pneumoniae raises concerns about potential misidentifications in addition to important questions concerning the consequences for vaccination and host-parasite relationships both for the commensals and for the pathogen. PMID:27935839

  5. Streptococcus oligofermentans Inhibits Streptococcus mutans in Biofilms at Both Neutral pH and Cariogenic Conditions

    PubMed Central

    Bao, Xudong; de Soet, Johannes Jacob; Tong, Huichun; Gao, Xuejun; He, Libang; van Loveren, Cor; Deng, Dong Mei

    2015-01-01

    Homeostasis of oral microbiota can be maintained through microbial interactions. Previous studies showed that Streptococcus oligofermentans, a non-mutans streptococci frequently isolated from caries-free subjects, inhibited the cariogenic Streptococcus mutans by the production of hydrogen peroxide (HP). Since pH is a critical factor in caries formation, we aimed to study the influence of pH on the competition between S. oligofermentans and S. mutans in biofilms. To this end, S. mutans and S. oligofermentans were inoculated alone or mixed at 1:1 ratio in buffered biofilm medium in a 96-well active attachment model. The single- and dual-species biofilms were grown under either constantly neutral pH or pH-cycling conditions. The latter includes two cycles of 8 h neutral pH and 16 h pH 5.5, used to mimic cariogenic condition. The 48 h biofilms were analysed for the viable cell counts, lactate and HP production. The last two measurements were carried out after incubating the 48 h biofilms in buffers supplemented with 1% glucose (pH 7.0) for 4 h. The results showed that S. oligofermentans inhibited the growth of S. mutans in dual-species biofilms under both tested pH conditions. The lactic acid production of dual-species biofilms was significantly lower than that of single-species S. mutans biofilms. Moreover, dual-species and single-species S. oligofermentans biofilms grown under pH-cycling conditions (with a 16 h low pH period) produced a significantly higher amount of HP than those grown under constantly neutral pH. In conclusion, S. oligofermentans inhibited S. mutans in biofilms not only under neutral pH, but also under pH-cycling conditions, likely through HP production. S. oligofermentans may be a compelling probiotic candidate against caries. PMID:26114758

  6. Antibiotic susceptibility of periodontal Streptococcus constellatus and Streptococcus intermedius clinical isolates.

    PubMed

    Rams, Thomas E; Feik, Diane; Mortensen, Joel E; Degener, John E; van Winkelhoff, Arie J

    2014-12-01

    Streptococcus constellatus and Streptococcus intermedius in subgingival dental plaque biofilms may contribute to forms of periodontitis that resist treatment with conventional mechanical root debridement/surgical procedures and may additionally participate in some extraoral infections. Because systemic antibiotics are often used in these clinical situations, and little is known of the antibiotic susceptibility of subgingival isolates of these two bacterial species, this study determined the in vitro susceptibility to six antibiotics of fresh S. constellatus and S. intermedius clinical isolates from human periodontitis lesions. A total of 33 S. constellatus and 17 S. intermedius subgingival strains, each recovered from separate patients with severe chronic periodontitis (n = 50) before treatment, were subjected to antibiotic gradient strip susceptibility testing with amoxicillin, azithromycin, clindamycin, ciprofloxacin, and doxycycline on blood-supplemented Mueller-Hinton agar and to the inhibitory effects of metronidazole at 16 mg/L in an enriched Brucella blood agar dilution assay. Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing interpretative standards were used to assess the results. Clindamycin was the most active antibiotic against S. constellatus (minimum inhibitory concentration at 90% [MIC90] 0.25 mg/L), and amoxicillin was most active against S. intermedius (MIC90 0.125 mg/L). A total of 30% of the S. constellatus and S. intermedius clinical isolates were resistant in vitro to doxycycline, 98% were only intermediate in susceptibility to ciprofloxacin, and 90% were resistant to metronidazole at 16 mg/L. Subgingival S. constellatus and S. intermedius exhibited variable antibiotic susceptibility profiles, potentially complicating empirical selection of periodontitis antibiotic therapy in patients who are species positive.

  7. Isolation and Characterization of Unsaturated Fatty Acid Auxotrophs of Streptococcus pneumoniae and Streptococcus mutans▿

    PubMed Central

    Altabe, Silvia; Lopez, Paloma; de Mendoza, Diego

    2007-01-01

    Unsaturated fatty acid (UFA) biosynthesis is essential for the maintenance of membrane structure and function in many groups of anaerobic bacteria. Like Escherichia coli, the human pathogen Streptococcus pneumoniae produces straight-chain saturated fatty acids (SFA) and monounsaturated fatty acids. In E. coli UFA synthesis requires the action of two gene products, the essential isomerase/dehydratase encoded by fabA and an elongation condensing enzyme encoded by fabB. S. pneumoniae lacks both genes and instead employs a single enzyme with only an isomerase function encoded by the fabM gene. In this paper we report the construction and characterization of an S. pneumoniae 708 fabM mutant. This mutant failed to grow in complex medium, and the defect was overcome by addition of UFAs to the growth medium. S. pneumoniae fabM mutants did not produce detectable levels of monounsaturated fatty acids as determined by gas chromatography-mass spectrometry and thin-layer chromatography analysis of the radiolabeled phospholipids. We also demonstrate that a fabM null mutant of the cariogenic organism Streptococcus mutants is a UFA auxotroph, indicating that FabM is the only enzyme involved in the control of membrane fluidity in streptococci. Finally we report that the fabN gene of Enterococcus faecalis, coding for a dehydratase/isomerase, complements the growth of S. pneumoniae fabM mutants. Taken together, these results suggest that FabM is a potential target for chemotherapeutic agents against streptococci and that S. pneumoniae UFA auxotrophs could help identify novel genes encoding enzymes involved in UFA biosynthesis. PMID:17827283

  8. Genome Sequence of the Oral Probiotic Streptococcus salivarius JF.

    PubMed

    Jia, Fang

    2016-09-22

    Streptococcus salivarius is a nonpathogenic Gram-positive bacterium and the predominant colonizer of the oral microbiota. It finds a wide application in the prevention of upper respiratory tract infections, also reducing the frequency of other main pathogens. Here, we present the complete genome sequence of the oral probiotic S. salivarius JF. Copyright © 2016 Jia.

  9. Pigment Production by Streptococcus agalactiae in Quasi-Defined Media

    PubMed Central

    Rosa-Fraile, Manuel; Sampedro, Antonio; Rodríguez-Granger, Javier; García-Peña, Maria Luisa; Ruiz-Bravo, Alfonso; Haïdour, Ali

    2001-01-01

    A quasi-defined medium that supports the growth of Streptococcus agalactiae as pigmented colonies has been developed. The medium contains starch, a peptic digest of albumin, amino acids, nucleosides, vitamins, and salts. The presence of free cysteine, which could be replaced with other sulphur-containing compounds and to a lesser degree by reducing agents, was required for pigment formation. PMID:11133484

  10. Streptococcus parasanguinis: new pathogen associated with asymptomatic mastitis in sheep.

    PubMed Central

    Fernández-Garayzábal, J. F.; Fernández, E.; Las Heras, A.; Pascual, C.; Collins, M. D.; Domínguez, L.

    1998-01-01

    We describe two unusual cases in sheep of subclinical mastitis caused by Streptococcus parasanguinis. This bacterium has been associated with the development of experimental endocarditis; its presence at relatively high concentrations in apparently healthy sheep milk may pose a health risk in persons with predisposing heart lesions. PMID:9866743

  11. Bacteremic pneumonia caused by extensively drug-resistant Streptococcus pneumoniae.

    PubMed

    Kang, Cheol-In; Baek, Jin Yang; Jeon, Kyeongman; Kim, So Hyun; Chung, Doo Ryeon; Peck, Kyong Ran; Lee, Nam Yong; Song, Jae-Hoon

    2012-12-01

    The emergence of antimicrobial resistance threatens the successful treatment of pneumococcal infections. Here we report a case of bacteremic pneumonia caused by an extremely drug-resistant strain of Streptococcus pneumoniae, nonsusceptible to at least one agent in all classes but vancomycin and linezolid, posing an important new public health threat in our region.

  12. Antimicrobial Drug Use and Macrolide-Resistant Streptococcus pyogenes, Belgium

    PubMed Central

    Van Heirstraeten, Liesbet; Coenen, Samuel; Lammens, Christine; Hens, Niel; Goossens, Herman

    2012-01-01

    In Belgium, decreasing macrolide, lincosamide, streptogramins B, and tetracycline use during 1997–2007 correlated significantly with decreasing macrolide-resistant Streptococcus pyogenes during 1999–2009. Maintaining drug use below a critical threshold corresponded with low-level macrolide-resistant S. pyogenes and an increased number of erm(A)-harboring emm77 S. pyogenes with low fitness costs. PMID:22932671

  13. Streptococcus intermedius liver abscesses and colon cancer: a case report.

    PubMed

    Millichap, J J; McKendrick, A I; Drelichman, V S

    2005-10-01

    Certain species of bacteria are known to be associated with colorectal cancer. We report a case of adenocarcinoma of the colon with bacteraemia and liver abscesses due to Streptococcus intermedius. The isolation of this organism should prompt investigation for colorectal neoplasm, which may be present but asymptomatic, without metastases, and therefore at a curative stage.

  14. Plasmid transfer via transduction from Streptococcus thermophilus to Lactococcus lactis.

    PubMed

    Ammann, Andreas; Neve, Horst; Geis, Arnold; Heller, Knut J

    2008-04-01

    Using Streptococcus thermophilus phages, plasmid transduction in Lactococcus lactis was demonstrated. The transduction frequencies were 4 orders of magnitude lower in L. lactis than in S. thermophilus. These results are the first evidence that there is phage-mediated direct transfer of DNA from S. thermophilus to L. lactis. The implications of these results for phage evolution are discussed.

  15. Streptococcus dysgalactiae subsp. equisimilis Bacteremia, Finland, 1995–2004

    PubMed Central

    Vähäkuopus, Susanna; Vuopio-Varkila, Jaana; Vuento, Risto; Syrjänen, Jaana

    2010-01-01

    We conducted a retrospective population-based study of 140 episodes of Streptococcus dysgalactiae subsp. equisimilis bacteremia occurring in Finland during 1995–2004. Rare emm types were associated with more severe disease and increased mortality rates. Skin and soft tissue infections were more frequent clinical signs among cases caused by common emm types. PMID:20409380

  16. Streptococcus dysgalactiae subsp. equisimilis Bacteremia, Finland, 1995-2004.

    PubMed

    Rantala, Sari; Vahakuopus, Susanna; Vuopio-Varkila, Jaana; Vuento, Risto; Syrjanen, Jaana

    2010-05-01

    We conducted a retrospective population-based study of 140 episodes of Streptococcus dysgalactiae subsp. equisimilis bacteremia occurring in Finland during 1995-2004. Rare emm types were associated with more severe disease and increased mortality rates. Skin and soft tissue infections were more frequent clinical signs among cases caused by common emm types.

  17. Anticariogenic activity of some tropical medicinal plants against Streptococcus mutans.

    PubMed

    Hwang, Jae-Kwan; Shim, Jae-Seok; Chung, Jae-Youn

    2004-09-01

    The methanol extracts of five tropical plants, Baeckea frutescens, Glycyrrhiza glabra, Kaempferia pandurata, Physalis angulata and Quercus infectoria, exhibited potent antibacterial activity against the cariogenic bacterium Streptococcus mutans. In particular, G. glabra, K. pandurata and P. angulata conferred fast killing bactericidal effect against S. mutans in 2 min at 50 microg/ml of extract concentration.

  18. Clinical and microbiological features of bacteremia with Streptococcus equi.

    PubMed

    Trell, Kristina; Nilson, Bo; Petersson, Ann-Cathrine; Rasmussen, Magnus

    2017-02-01

    Streptococcus equi (SE) rarely causes human infections. We identified 18 SE isolates from blood cultures. The focus of infection was unknown (n = 5), arthritis (n = 3), catheter-related (n = 2), pneumonia (n = 2), or other (n = 6). There were no fatalities. Several patients had animal contacts but there were no indications of clonal outbreaks.

  19. Following the equator: division site selection in Streptococcus pneumoniae.

    PubMed

    Bramkamp, Marc

    2015-03-01

    The mechanisms that spatially regulate cytokinesis are more diverse than initially thought. In two recent publications a positive regulator of FtsZ positioning has been identified in Streptococcus pneumoniae. MapZ (LocZ) connects the division machinery with cell wall elongation, providing a simple mechanism to ensure correct division site selection.

  20. Streptococcus equi subsp. zooepidemicus Infections Associated with Guinea Pigs

    PubMed Central

    Young, Andrea; Levine, Seth J.; Garvin, Joseph P.; Brown, Susan; Turner, Lauren; Fritzinger, Angela; Gertz, Robert E.; Murphy, Julia M.; Vogt, Marshall; Beall, Bernard

    2015-01-01

    Streptococcus equi subsp. zooepidemicus is a known zoonotic pathogen. In this public health investigation conducted in Virginia, USA, in 2013, we identified a probable family cluster of S. zooepidemicus cases linked epidemiologically and genetically to infected guinea pigs. S. zooepidemicus infections should be considered in patients who have severe clinical illness and report guinea pig exposure. PMID:25531424

  1. Streptococcus bovis as a Silage Inoculant, a Second Chance

    USDA-ARS?s Scientific Manuscript database

    Previous research indicated that Streptococcus bovis, a lactate producing ruminal bacterium, was similar or better than commercial silage inoculants. This study assessed the potential of two S. bovis strains, JB1 (a bacteriocin negative strain) and HC5 (a bacteriocin producing strain). Four treatmen...

  2. Emerging resistant serotypes of invasive Streptococcus pneumoniae

    PubMed Central

    Elshafie, Sittana; Taj-Aldeen, Saad J

    2016-01-01

    Background Streptococcus pneumoniae is the leading cause of meningitis and sepsis. The aim of the study was to analyze the distribution, vaccine serotype coverage, and antibiotic resistance of S. pneumoniae serotypes isolated from patients with invasive diseases, after the introduction of pneumococcal 7-valent conjugated vaccine (PCV-7). Methods A total of 134 isolates were collected from blood and cerebrospinal fluid specimens at Hamad Hospital during the period from 2005 to 2009. Isolate serotyping was done using the Quellung reaction. The prevaccination period was considered before 2005. Results The most common serotypes for all age groups were 3 (12.70%), 14 (11.90%), 1 (11.90%), 19A (9.00%), 9V (5.20%), 23F (5.20%), and 19F (4.50%). Coverage rates for infant <2 years for PCV-7, the 10-valent conjugated vaccine (PCV-10), and the 13-valent conjugated vaccine (PCV-13) were 34.78%, 52.17%, and 78.26%, respectively. Coverage rates of these vaccines were 50%, 67.86%, and 75% for the 2–5 years age group; 27.12%, 40.68%, and 64.41% for the age group 6–64 years; and 25%, 33.33%, and 66.67% for the ≥65 years age group, respectively. The percentage of nonsusceptible isolates to penicillin, cefotaxime, and erythromycin were 43.86%, 16.66%, and 22.81%, respectively. Thirty-seven isolates (32.46%) were multidrug resistant (MDR) and belonged to serotypes 14, 19A, 19F, 23F, 1, 9V, 12F, 4, 6B, 3, and 15A. Compared to previous results before the introduction of PCV-7, there was a significant reduction in penicillin-nonsusceptable S. pneumoniae from 66.67% to 43.86%, and a slight insignificant reduction in erythromycin nonsusceptible strains from 27.60% to 22.8%, while there was a significant increase in cefotaxime nonsusceptible strains from 3.55% to 16.66%. Conclusion Invasive pneumococcal strains and the emergence of MDR serotypes is a global burden that must be addressed through multiple strategies, including vaccination, antibiotic stewardship, and continuous

  3. Next generation protein based Streptococcus pneumoniae vaccines

    PubMed Central

    Pichichero, Michael E; Khan, M Nadeem; Xu, Qingfu

    2016-01-01

    All currently available Streptococcus pneumoniae (Spn) vaccines have limitations due to their capsular serotype composition. Both the 23-valent Spn polysaccharide vaccine (PPV) and 7, 10, or 13-valent Spn conjugate vaccines (PCV-7, 10, -13) are serotype-based vaccines and therefore they elicit only serotype-specific immunity. Emergence of replacement Spn strains expressing other serotypes has consistently occurred following introduction of capsular serotype based Spn vaccines. Furthermore, capsular polysaccharide vaccines are less effective in protection against non-bacteremic pneumonia and acute otitis media (AOM) than against invasive pneumococcal disease (IPD). These shortcomings of capsular polysaccharide-based Spn vaccines have created high interest in development of non-serotype specific protein-based vaccines that could be effective in preventing both IPD and non-IPD infections. This review discusses the progress to date on development of Spn protein vaccine candidates that are highly conserved by all Spn strains, are highly conserved, exhibit maximal antigenicity and minimal reactogenicity to replace or complement the current capsule-based vaccines. Key to development of a protein based Spn vaccine is an understanding of Spn pathogenesis. Based on pathogenesis, a protein-based Spn vaccine should include one or more ingredients that reduce NP colonization below a pathogenic inoculum. Elimination of all Spn colonization may not be achievable or even advisable. The level of expression of a target protein antigen during pathogenesis is another key to the success of protein based vaccines.. As with virtually all currently licensed vaccines, production of a serum antibody response in response to protein based vaccines is anticipated to provide protection from Spn infections. A significant advantage that protein vaccine formulations can offer over capsule based vaccination is their potential benefits associated with natural priming and boosting to all strains of

  4. Next generation protein based Streptococcus pneumoniae vaccines.

    PubMed

    Pichichero, Michael E; Khan, M Nadeem; Xu, Qingfu

    2016-01-01

    All currently available Streptococcus pneumoniae (Spn) vaccines have limitations due to their capsular serotype composition. Both the 23-valent Spn polysaccharide vaccine (PPV) and 7, 10, or 13-valent Spn conjugate vaccines (PCV-7, 10, -13) are serotype-based vaccines and therefore they elicit only serotype-specific immunity. Emergence of replacement Spn strains expressing other serotypes has consistently occurred following introduction of capsular serotype based Spn vaccines. Furthermore, capsular polysaccharide vaccines are less effective in protection against non-bacteremic pneumonia and acute otitis media (AOM) than against invasive pneumococcal disease (IPD). These shortcomings of capsular polysaccharide-based Spn vaccines have created high interest in development of non-serotype specific protein-based vaccines that could be effective in preventing both IPD and non-IPD infections. This review discusses the progress to date on development of Spn protein vaccine candidates that are highly conserved by all Spn strains, are highly conserved, exhibit maximal antigenicity and minimal reactogenicity to replace or complement the current capsule-based vaccines. Key to development of a protein based Spn vaccine is an understanding of Spn pathogenesis. Based on pathogenesis, a protein-based Spn vaccine should include one or more ingredients that reduce NP colonization below a pathogenic inoculum. Elimination of all Spn colonization may not be achievable or even advisable. The level of expression of a target protein antigen during pathogenesis is another key to the success of protein based vaccines.. As with virtually all currently licensed vaccines, production of a serum antibody response in response to protein based vaccines is anticipated to provide protection from Spn infections. A significant advantage that protein vaccine formulations can offer over capsule based vaccination is their potential benefits associated with natural priming and boosting to all strains of

  5. Epidemiology of Streptococcus agalactiae colonization in Germany.

    PubMed

    Brimil, Nadia; Barthell, Elisabeth; Heindrichs, Uwe; Kuhn, Melanie; Lütticken, Rudolf; Spellerberg, Barbara

    2006-02-01

    Streptococcus agalactiae can cause severe pneumonia, sepsis and meningitis in neonates and remains one of the most prevalent causes of invasive neonatal infections. Maternal transmission of S. agalactiae during delivery can be prevented by prenatal screening and peripartal antibiotic prophylaxis. Implementation of CDC guidelines for group B streptococci (GBS) disease prevention resulted in a significant decline of invasive neonatal S. agalactiae infections in the USA. Similar national guidelines were issued in 2000 for Germany. However, the epidemiology of S. agalactiae colonization in Germany has not been investigated for more than 15 years and the impact these guidelines will have is therefore unknown. To assess colonization rates in Germany, we cultured vaginal and rectal swabs for S. agalactiae from pregnant and non-pregnant adult patients in the region of Aachen and Munich. Swabs were cultivated in selective broth medium for 24h and subsequently plated on blood agar plates according to the CDC recommendations. Colonies negative for catalase and pyrrolidonyl aminopeptidase were further differentiated by the CAMP test and a DNA probe specific for S. agalactiae. Rectal or vaginal colonization of S. agalactiae was found in 34 (16%) of 210 pregnant patients and in 41 (16%) of 250 non-pregnant women. S. agalactiae was found only in rectal swabs in 4% of pregnant and non-pregnant patients. For further characterization of the strains capsular serotypes and major surface protein antigens were determined by Ouchterlony immunodiffusion and PCR. Among the 75 different patient isolates serotype III was the most prevalent with 21 (28%) isolates, followed by 16 (21%) isolates of serotype II, 13 (17%) isolates of serotype Ia, 12 (16%) of serotype V, 11 (15%) of serotype Ib and only 2 (3%) isolates of serotype IV. The vast majority of all strains harbored genes for the major surface protein antigens, the alpha-C-protein or alpha-C-protein like antigens like Alp2-4, epsilon and

  6. [Sensitivity profile of Staphylococcus spp. and Streptococcus spp. isolated from toys used in a teaching hospital playroom].

    PubMed

    Boretti, Vanessa Stolf; Corrêa, Renata Nunes; dos Santos, Silvana Soléo Ferreira; Leão, Mariella Vieira Pereira; Gonçalves e Silva, Célia Regina

    2014-09-01

    To evaluate the presence of microorganisms of the genus Staphylococcus and Streptococcus on toys in the playroom of a teaching hospital, as well to as analyze the antimicrobial from the isolated strains. Samples were collected from 60 toys, using wet swabs, soon after being used by the children. The samples were inoculated in enriched and selective agar for isolation and later identification of the microorganisms. Antibiogram testing was performed by agar diffusion technique. The genus Staphylococcus was present in 87.0% (52/60) of the toys. Seventythree strains were isolated, with 29.0% (21/73) coagulase-positive and 71.0% (52/73) coagulase-negative. Among the coagulase-negative strains, 90.4% were resistant to penicillin, 65.4% to oxacillin, 28.8% to clarithromycin, 61.5% to clindamycin, and none to vancomycin. Among the coagulase-positive strains, 76.2% were resistant to penicillin, 23.8% to oxacillin, 23.8% to clarithromycin, 47.6% to clindamycin, and none to vancomycin. The genus Streptococcus was not detected in any of the evaluated toys. Toys can be contaminated with potentially pathogenic bacteria with antimicrobial resistance, representing a possible source of nosocomial infection for patients who are already debilitated. Copyright © 2014 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  7. Comparison of transmission dynamics between Streptococcus uberis and Streptococcus agalactiae intramammary infections.

    PubMed

    Leelahapongsathon, Kansuda; Schukken, Ynte Hein; Pinyopummintr, Tanu; Suriyasathaporn, Witaya

    2016-02-01

    The objectives of study were to determine the transmission parameters (β), durations of infection, and basic reproductive numbers (R0) of both Streptococcus agalactiae and Streptococcus uberis as pathogens causing mastitis outbreaks in dairy herds. A 10-mo longitudinal study was performed using 2 smallholder dairy herds with mastitis outbreaks caused by Strep. agalactiae and Strep. uberis, respectively. Both herds had poor mastitis control management and did not change their milking management during the entire study period. Quarter milk samples were collected at monthly intervals from all lactating animals in each herd for bacteriological identification. The durations of infection for Strep. uberis intramammary infection (IMI) and Strep. agalactiae IMI were examined using Kaplan-Meier survival curves, and the Kaplan-Meier survival functions for Strep. uberis IMI and Strep. agalactiae IMI were compared using log rank survival-test. The spread of Strep. uberis and Strep. agalactiae through the population was determined by transmission parameter, β, the probability per unit of time that one infectious quarter will infect another quarter, assuming that all other quarters are susceptible. For the Strep. uberis outbreak herd (31 cows), 56 new infections and 28 quarters with spontaneous cure were observed. For the Strep. agalactiae outbreak herd (19 cows), 26 new infections and 9 quarters with spontaneous cure were observed. The duration of infection for Strep. agalactiae (mean=270.84 d) was significantly longer than the duration of infection for Strep. uberis (mean=187.88 d). The transmission parameters (β) estimated (including 95% confidence interval) for Strep. uberis IMI and Strep. agalactiae IMI were 0.0155 (0.0035-0.0693) and 0.0068 (0.0008-0.0606), respectively. The R0 (including 95% confidence interval) during the study were 2.91 (0.63-13.47) and 1.86 (0.21-16.61) for Strep. uberis IMI and Strep. agalactiae IMI, respectively. In conclusion, the transmission

  8. Streptococcus mutans and Streptococcus intermedius adhesion to fibronectin films are oppositely influenced by ionic strength.

    PubMed

    Busscher, Henk J; van de Belt-Gritter, Betsy; Dijkstra, Rene J B; Norde, Willem; van der Mei, Henny C

    2008-10-07

    Bacterial adhesion to protein-coated surfaces is mediated by an interplay of specific and nonspecific interactions. Although nonspecific interactions are ubiquitously present, little is known about the physicochemical mechanisms of specific interactions. The aim of this paper is to determine the influence of ionic strength on the adhesion of two streptococcal strains to fibronectin films. Streptococcus mutans LT11 and Streptococcus intermedius NCTC11324 both possess antigen I/II with the ability to bind fibronectin from solution, but S. intermedius binds approximately 20x less fibronectin than does the S. mutans strain under identical conditions. Both strains as well as fibronectin films are negatively charged in low ionic strength phosphate buffered saline (PBS, 10x diluted), but bacteria appear uncharged in high ionic strength PBS. Physicochemical modeling on the basis of overall cell surface properties (cell surface hydrophobicity and zeta potentials) demonstrates that both strains should favor adhesion to fibronectin films in a high ionic strength environment as compared to in a low ionic strength environment, where electrostatic repulsion between equally charged surfaces is dominant. Adhesion of S. intermedius to fibronectin films in a parallel plate flow chamber was completely in line with this modeling, while in addition atomic force microscopy (AFM) indicated stronger adhesion forces upon retraction between fibronectin-coated tips and the cell surfaces in high ionic strength PBS than in low ionic strength PBS. Thus, the dependence of the interaction on ionic strength is dominated by the overall negative charge on the interacting surfaces. Adhesion of S. mutans to fibronectin films, however, was completely at odds with theoretical modeling, and the strain adhered best in low ionic strength PBS. Moreover, AFM indicated weaker repulsive forces upon approach between fibronectin-coated tips and the cell surfaces in low ionic strength PBS than in high ionic

  9. Necrotizing fasciitis due to Streptococcus mitis caused by accidental human bite.

    PubMed

    Bastug, Aliye; Kislak, Sumeyye; Mutlu, Nevzat Mehmet; Akcaboy, Zeynep Nur; Koksal, Asude; Sertcelik, Ahmet; Ünlü, Ramazan Erkin; Akinci, Esragul; Bodur, Hurrem

    2016-01-31

    Human bite wounds are more prone to infection than animal bites, which may cause necrotizing soft tissue infections such as myositis, fasciitis. Both aerobic and anaerobic microorganisms may be responsible, including Streptococcus spp., Staphylococcus aureus, Peptostreptococcus spp. Necrotizing fasciitis is characterized by serious tissue destruction and systemic toxicity with high morbidity and mortality. We report a patient with Streptococcus mitis associated necrotizing fasciitis on the upper extremity resulting from an accidental human bite, which caused nearly fatal infection. Prophylactic antibiotic treatment should be given after a human bite to prevent infection. If the infection signs and symptoms develop, rapid diagnosis, appropriate antibiotic and surgical therapy should be administered immediately. Streptococcus mitis is a viridans streptococcus, usually known as a relatively benign oral streptococcus. To our knowledge, this is the first necrotizing fasciitis case due to Streptococcus mitis after human bite.

  10. Growth inhibition of Streptococcus mutans by cellular extracts of human intestinal lactic acid bacteria.

    PubMed Central

    Ishihara, K; Miyakawa, H; Hasegawa, A; Takazoe, I; Kawai, Y

    1985-01-01

    The in vitro growth of Streptococcus mutans was completely inhibited by water-soluble extracts from cells of various intestinal lactic acid bacteria identified as Streptococcus faecium, Streptococcus equinus, Lactobacillus fermentum, and Lactobacillus salivarius. The growth inhibition was dependent on the concentrations of the extracts. In contrast, the extracts did not inhibit the growth of the major indigenous intestinal lactic acid bacteria isolated from humans. These lactic acid bacteria were not acutely toxic in mice. PMID:4030098

  11. Draft Genome Sequences for Seven Streptococcus parauberis Isolates from Wild Fish in the Chesapeake Bay.

    PubMed

    Haines, Ashley; Nebergall, Emily; Besong, Elvira; Council, Kimaya; Lambert, Onaysha; Gauthier, David

    2016-08-18

    Streptococcus parauberis is a pathogen of cattle and fish, closely related Streptococcus uberis and Streptococcus iniae We report the genomes of seven S. parauberis strains recovered from striped bass (Morone saxatilis) in the Chesapeake Bay. The availability of these genomes will allow comparative genomic analysis of Chesapeake Bay S. parauberis strains versus S. parauberis cultured from other animal hosts and geographic regions. Copyright © 2016 Haines et al.

  12. Streptococcus intermedius: an unusual cause of a primary empyema.

    PubMed

    Iskandar, Said B; Al Hasan, Muhanad A; Roy, Thomas M; Byrd, Ryland P

    2006-02-01

    Despite the evolution of modern antibiotics, pleural space infection remains a common illness with significant morbidity and mortality. Every year up to 60 percent of the 1.2 million patients in the United States who present with community-acquired pneumonia develop parapneumonic pleural effusions. Few of these parapneumonic effusions progress to an empyema. Interestingly, in about 10 percent of the cases of empyema, no underlying pulmonary infection can be identified. These pleural space infections are called primary empyemas. We present a patient with a primary empyema caused by Streptococcus intermedius. Relatively few studies have investigated primary empyema caused Streptococcus intermedius. This case presentation serves as a reminder to the clinician about primary empyema caused by this micro-organism.

  13. Colorectal Cancer Associated with Streptococcus anginosus Bacteremia and Liver Abscesses

    PubMed Central

    Masood, Umair; Sharma, Anuj; Lowe, Dhruv; Khan, Rashad; Manocha, Divey

    2016-01-01

    Streptococcus anginosus is part of the normal flora of the human gastrointestinal tract. Their ability to cause abscesses is very unique and sets them apart from the rest of the streptococci groups. While an association of group D streptococcus bacteremia and endocarditis with colorectal carcinoma is well established, S. anginosus infections are rarely implicated with colonic malignancy. We present a case of a 62-year-old male who presented to the hospital with fatigue and generalized abdominal pain. Computed tomography of the abdomen revealed multiple liver abscesses and rectal thickening. Blood cultures were found to grow S. anginosus bacteria. Colonoscopy revealed a rectal mass which was later confirmed to be rectal adenocarcinoma. This case presents an association between S. anginosus bacteremia and presence of colorectal cancer which has been highlighted in only a few case reports in literature. This should prompt clinicians to screen for colorectal cancer in patients with S. anginosus bacteremia. PMID:28100999

  14. Periorbital Necrotizing Fasciitis Secondary to Candida parapsilosis and Streptococcus pyogenes.

    PubMed

    Zhang, Matthew; Chelnis, James; Mawn, Louise A

    Necrotizing fasciitis is most often caused by either polymicrobial bacterial infections or by Gram-positive organisms, such as Streptococcus or Staphylococcus; however, rare cases of fungal necrotizing fasciitis have been reported. Candida parapsilosis is an emerging fungal pathogen. This fungus grows in either a yeast or pseudohyphal form. C. parapsilosis has been reported to cause keratitis, intraocular infection, and seeding of frontalis slings. C. parapsilosis is a commensal of human skin and can be acquired by nosocomial spread. Necrotizing fasciitis due to Candida has rarely been reported, but to date C. parapsilosis has not been identified as the causative organism in necrotizing fasciitis. This is the first documented case of human periocular soft tissue infection by C. parapsilosis, and also the first report providing evidence of mycotic infection in a necrotizing fasciitis concurrently infected by Streptococcus pyogenes.

  15. Clinical implications and treatment of multiresistant Streptococcus pneumoniae pneumonia.

    PubMed

    File, T M

    2006-05-01

    Streptococcus pneumoniae is the leading bacterial cause of community-acquired respiratory tract infections. Prior to the 1970s this pathogen was uniformly susceptible to penicillin and most other antimicrobials. However, since the 1990s there has been a significant increase in drug-resistant Streptococcus pneumoniae (DRSP) due, in large part, to increased use of antimicrobials. The clinical significance of this resistance is not definitely established, but appears to be most relevant to specific MICs for specific antimicrobials. Certain beta-lactams (amoxicillin, cefotaxime, ceftriaxone), the respiratory fluoroquinolones, and telithromycin are among several agents that remain effective against DRSP. Continued surveillance studies, appropriate antimicrobial usage campaigns, stratification of patients based on known risk factors for resistance, and vaccination programmes are needed to appropriately manage DRSP and limit its spread.

  16. ANTIMICROBIAL SUSCEPTIBILITY OF Streptococcus agalactiae ISOLATED FROM PREGNANT WOMEN

    PubMed Central

    de MELO, Simone Cristina Castanho Sabaini; SANTOS, Nathally Claudiane de Souza; de OLIVEIRA, Marcia; SCODRO, Regiane Bertin de Lima; CARDOSO, Rosilene Fressatti; PÁDUA, Rúbia Andreia Falleiros; SILVA, Flavia Teixeira Ribeiro; COSTA, Aline Balandis; CARVALHO, Maria Dalva de Barros; PELLOSO, Sandra Marisa

    2016-01-01

    SUMMARY Introduction: Group B streptococcus (GBS) or Streptococcus agalactiae can colonize the gastrointestinal and genitourinary tracts and has been considered one of the most important risk factors for the development of neonatal disease. The present study evaluated the antimicrobial susceptibility of GBS isolates from pregnant women who were attended at a public health service in Northern Paraná, Brazil. Methods: A descriptive analytical cross-sectional study was performed with 544 pregnant women, at ≥ 35 weeks of gestation. One hundred and thirty-six GBS isolates from pregnant women were tested for antimicrobial susceptibility. Results: All of the GBS isolates showed susceptibility to the drug that is most frequently used for intrapartum prophylaxis: penicillin. Resistance to clindamycin and erythromycin was detected, thus decreasing the options of prophylaxis in women who are allergic to penicillin. Conclusions: Additional studies should be conducted to increase the knowledge of GBS sensitivity profile to antimicrobials in other health centers. PMID:27828624

  17. Splenic abscess and multiple brain abscesses caused by Streptococcus intermedius in a young healthy man.

    PubMed

    Maliyil, Jepsin; Caire, William; Nair, Rajasree; Bridges, Debbie

    2011-07-01

    We report a case of splenic abscess with multiple brain abscesses caused by Streptococcus intermedius in a healthy young man without any identifiable risk factors, which resolved with percutaneous drainage and antibiotics. Streptococcus intermedius, a member of the Streptococcus anginosus group, is a common commensal organism of the oral cavity and gastrointestinal tract, and it is a known cause of deep-seated infections. Suppurative infections caused by Streptococcus anginosus group are sometimes associated with bacteremia, but hematogenous spread of infection from an occult source leading to concurrent splenic abscess and multiple brain abscesses has never been previously reported in a healthy young individual.

  18. [Partial gene clone and nif gene homologous sequence analysis of Streptococcus sanguis].

    PubMed

    Pan, Y; Wang, H; Jin, C; Sun, K

    1999-02-01

    To analyze the sequence of Streptococcus sanguis chromosome which contains one DNA fragment of 800 base pairs (bp) and discuss Streptococcus sanguis biological features of heredity. Streptococcus DNA of 800-bp genetic fragment was cloned and analyzed by using eukaryotic expression vector. By Genbank database, it showed that the 800-bp genetic sequence was highly homologous with other bacterial nifS and nifU gene, and the highest homologous score was 114. This nif gene of ATCC 10556 strain may correlate with nutrient metabolism and peroxide hydrogen release of Streptococcus sanguis.

  19. Phenotypic, Genotypic, and Antimicrobial Characteristics of Streptococcus halichoeri Isolates from Humans, Proposal To Rename Streptococcus halichoeri as Streptococcus halichoeri subsp. halichoeri, and Description of Streptococcus halichoeri subsp. hominis subsp. nov., a Bacterium Associated with Human Clinical Infections.

    PubMed

    Shewmaker, P L; Whitney, A M; Humrighouse, B W

    2016-03-01

    Phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain of Streptococcus halichoeri isolated from a seal are presented. Sequencing of the 16S rRNA, rpoB, sodA, and recN genes; comparative whole-genome analysis; conventional biochemical and Rapid ID 32 Strep identification methods; and antimicrobial susceptibility testing were performed on the human isolates, the type strain of S. halichoeri, and type strains of closely related species. The six human clinical isolates were biochemically indistinguishable from each other and showed 100% 16S rRNA, rpoB, sodA, and recN gene sequence similarity. Comparative 16S rRNA gene sequencing analysis revealed 98.6% similarity to S. halichoeri CCUG 48324(T), 97.9% similarity to S. canis ATCC 43496(T), and 97.8% similarity to S. ictaluri ATCC BAA-1300(T). A 3,530-bp fragment of the rpoB gene was 98.8% similar to the S. halichoeri type strain, 84.6% to the S. canis type strain, and 83.8% to the S. ictaluri type strain. The S. halichoeri type strain and the human clinical isolates were susceptible to the antimicrobials tested based on CLSI guidelines for Streptococcus species viridans group with the exception of tetracycline and erythromycin. The human isolates were phenotypically distinct from the type strain isolated from a seal; comparative whole-genome sequence analysis confirmed that the human isolates were S. halichoeri. On the basis of these results, a novel subspecies, Streptococcus halichoeri subsp. hominis, is proposed for the human isolates and Streptococcus halichoeri subsp. halichoeri is proposed for the gray seal isolates. The type strain of the novel subspecies is SS1844(T) = CCUG 67100(T) = LMG 28801(T). Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  20. Identification of Streptococcus pneumoniae with a DNA probe.

    PubMed Central

    Denys, G A; Carey, R B

    1992-01-01

    The Accuprobe Streptococcus pneumoniae Culture Identification Test (Gen-Probe, Inc.) was evaluated with 172 isolates of S. pneumoniae and 204 nonpneumococcal isolates. The sensitivity and specificity of the Accuprobe test were 100%. Optimum results were obtained when four or more discrete colonies were selected for testing. The Accuprobe test was determined to be an accurate and rapid method for identification of S. pneumoniae. PMID:1400974

  1. First Report of the Multiresistance Gene cfr in Streptococcus suis

    PubMed Central

    Wang, Yang; Li, Dexi; Song, Li; Liu, Yang; He, Tao; Liu, Hebing; Wu, Congming

    2013-01-01

    The multiresistance gene cfr was identified for the first time in streptococci, namely, in porcine Streptococcus suis isolate S10. The cfr gene was detected on the ∼100-kb plasmid pStrcfr, where it was bracketed by two copies of the novel insertion sequence ISEnfa5, located in the same orientation. The detection of a cfr- and ISEnfa5-containing amplicon by inverse PCR suggests that ISEnfa5 may play a role in the dissemination of cfr. PMID:23733472

  2. First Characterization of Fluoroquinolone Resistance in Streptococcus suis▿

    PubMed Central

    Escudero, Jose Antonio; San Millan, Alvaro; Catalan, Ana; de la Campa, Adela G.; Rivero, Estefania; Lopez, Gema; Dominguez, Lucas; Moreno, Miguel Angel; Gonzalez-Zorn, Bruno

    2007-01-01

    We have identified and sequenced the genes encoding the quinolone-resistance determining region (QRDR) of ParC and GyrA in fluoroquinolone-susceptible and -resistant Streptococcus suis clinical isolates. Resistance is the consequence of single point mutations in the QRDRs of ParC and GyrA and is not due to clonal spread of resistant strains or horizontal gene transfer with other bacteria. PMID:17116660

  3. Disseminated Streptococcus pneumoniae infection involving a ventricular assist device

    PubMed Central

    Reeves, J.S.; Rajagopalan, N.; Huaman, M.A.

    2015-01-01

    We describe the first reported case, to our knowledge, of disseminated pneumococcal infection involving a left ventricular assist device (LVAD). The management of this infection was extremely challenging, requiring multiple surgical debridements, LVAD removal, and prolonged courses of antibiotics. The Streptococcus pneumoniae isolate was found to be serotype 19F, which is included in both the pneumococcal polysaccharide and conjugate vaccines. This report highlights the importance of routine screening for up-to-date vaccination in patients who undergo LVAD implantation. PMID:26073334

  4. Disseminated Streptococcus pneumoniae infection involving a ventricular assist device.

    PubMed

    Reeves, J S; Rajagopalan, N; Huaman, M A

    2015-08-01

    We describe the first reported case, to our knowledge, of disseminated pneumococcal infection involving a left ventricular assist device (LVAD). The management of this infection was extremely challenging, requiring multiple surgical debridements, LVAD removal, and prolonged courses of antibiotics. The Streptococcus pneumoniae isolate was found to be serotype 19F, which is included in both the pneumococcal polysaccharide and conjugate vaccines. This report highlights the importance of routine screening for up-to-date vaccination in patients who undergo LVAD implantation.

  5. Streptococcus equi subspecies equi infection (strangles) in horses.

    PubMed

    Boyle, Ashley

    2011-03-01

    Streptococcus equi subspecies equi (strangles) is a highly contagious upper respiratory infection in horses. The infection is transmitted by inhalation or direct contact with mucopurulent discharge from an infective animal, resulting in fever, depression, and submandibular and retropharyngeal lymph node enlargement that can lead to respiratory distress. Complications include purpura hemorrhagica and metastatic abscessation. Control of outbreaks requires strict isolation protocols and hygiene measures. Detection of carriers is essential for preventing disease recurrence on a farm.

  6. Phenotypic, Genotypic, and Antimicrobial Characteristics of Streptococcus halichoeri Isolates from Humans, Proposal To Rename Streptococcus halichoeri as Streptococcus halichoeri subsp. halichoeri, and Description of Streptococcus halichoeri subsp. hominis subsp. nov., a Bacterium Associated with Human Clinical Infections

    PubMed Central

    Whitney, A. M.; Humrighouse, B. W.

    2016-01-01

    Phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain of Streptococcus halichoeri isolated from a seal are presented. Sequencing of the 16S rRNA, rpoB, sodA, and recN genes; comparative whole-genome analysis; conventional biochemical and Rapid ID 32 Strep identification methods; and antimicrobial susceptibility testing were performed on the human isolates, the type strain of S. halichoeri, and type strains of closely related species. The six human clinical isolates were biochemically indistinguishable from each other and showed 100% 16S rRNA, rpoB, sodA, and recN gene sequence similarity. Comparative 16S rRNA gene sequencing analysis revealed 98.6% similarity to S. halichoeri CCUG 48324T, 97.9% similarity to S. canis ATCC 43496T, and 97.8% similarity to S. ictaluri ATCC BAA-1300T. A 3,530-bp fragment of the rpoB gene was 98.8% similar to the S. halichoeri type strain, 84.6% to the S. canis type strain, and 83.8% to the S. ictaluri type strain. The S. halichoeri type strain and the human clinical isolates were susceptible to the antimicrobials tested based on CLSI guidelines for Streptococcus species viridans group with the exception of tetracycline and erythromycin. The human isolates were phenotypically distinct from the type strain isolated from a seal; comparative whole-genome sequence analysis confirmed that the human isolates were S. halichoeri. On the basis of these results, a novel subspecies, Streptococcus halichoeri subsp. hominis, is proposed for the human isolates and Streptococcus halichoeri subsp. halichoeri is proposed for the gray seal isolates. The type strain of the novel subspecies is SS1844T = CCUG 67100T = LMG 28801T. PMID:26763962

  7. Bullous impetigo caused by Streptococcus salivarius: a case report.

    PubMed Central

    Brook, I

    1980-01-01

    A 19-month-old child presented with bullous impetigo around the perineal region, penis, and left foot. Streptococcus salivarius was the only isolate recovered from the lesions. The child was treated with parenteral penicillin, debridement of the bulli, and local application of silver sulphadiazine cream. This case of bullous impetigo illustrates another aspect of the pathogenicity of Strep. salivarius. Images Fig. 1 Fig. 2 PMID:7002959

  8. Characterization of Streptococcus salivarius growth and maintenance in artificial saliva.

    PubMed

    Roger, P; Delettre, J; Bouix, M; Béal, C

    2011-09-01

    To help gain a better understanding of factors influencing the establishment within the oral cavity of Streptococcus salivarius K12, a commensal oral bacterium, we characterized its behaviour in artificial saliva. Streptococcus salivarius K12 was grown in artificial saliva complemented with a representative meal, under oral pH and temperature conditions. Exponential growth phase was characterized by a high specific growth rate (2.8 h(-1)). During maintenance phase, an uncoupling between growth and lactic acid production occurred, which allowed maintaining viability (95%), intracellular pH (6.6) and membrane polarisation (95%), and thus proton motive force. However, in late stationary phase, viability (64%) and vitality were degraded as a result of lower synthesis of energetic and glycogen-related proteins as compared to a richer medium. Streptococcus salivarius was able to rapidly grow in complemented artificial saliva. Nevertheless, a degradation of its physiological state was observed in late-stationary phase. This work demonstrates, for the first time, that artificial saliva was a convenient medium that permitted Strep. salivarius to grow in oral conditions (physico-chemical environment, addition of meals) but not to maintain cellular viability and vitality in starvation conditions. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  9. Characterization of salivary alpha-amylase binding to Streptococcus sanguis

    SciTech Connect

    Scannapieco, F.A.; Bergey, E.J.; Reddy, M.S.; Levine, M.J. )

    1989-09-01

    The purpose of this study was to identify the major salivary components which interact with oral bacteria and to determine the mechanism(s) responsible for their binding to the bacterial surface. Strains of Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans, and Actinomyces viscosus were incubated for 2 h in freshly collected human submandibular-sublingual saliva (HSMSL) or parotid saliva (HPS), and bound salivary components were eluted with 2% sodium dodecyl sulfate. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western transfer, alpha-amylase was the prominent salivary component eluted from S. sanguis. Studies with {sup 125}I-labeled HSMSL or {sup 125}I-labeled HPS also demonstrated a component with an electrophoretic mobility identical to that of alpha-amylase which bound to S. sanguis. Purified alpha-amylase from human parotid saliva was radiolabeled and found to bind to strains of S. sanguis genotypes 1 and 3 and S. mitis genotype 2, but not to strains of other species of oral bacteria. Binding of ({sup 125}I)alpha-amylase to streptococci was saturable, calcium independent, and inhibitable by excess unlabeled alpha-amylases from a variety of sources, but not by secretory immunoglobulin A and the proline-rich glycoprotein from HPS. Reduced and alkylated alpha-amylase lost enzymatic and bacterial binding activities. Binding was inhibited by incubation with maltotriose, maltooligosaccharides, limit dextrins, and starch.

  10. FORMATION OF PROTOPLASTS FROM STREPTOCOCCUS FAECALIS BY LYSOZYME1

    PubMed Central

    Bibb, William R.; Straughn, W. R.

    1962-01-01

    Bibb, William R. (University of North Carolina, Chapel Hill) and W. R. Straughn. Formation of protoplasts from Streptococcus faecalis by lysozyme. J. Bacteriol. 84:1094–1098. 1962.—Incubation of whole cells of Streptococcus faecalis F24 in the presence of the crystalline egg-white lysozyme and appropriate sucrose concentration resulted in the formation of discrete spherical structures. On dilution, these osmotically fragile structures lysed immediately. Methyl pentose determinations on isolated cell walls and protoplast membranes verified the presence of rhamnose in the cell walls and its essentially complete absence in protoplast membranes. Cell walls were rendered soluble by lysozyme. After lysozyme treatment of cell walls, 96% of the rhamnose present was not sedimented by centrifugation at 12,500 × g for 30 min. No cell-wall structures were recognized by phasecontrast or electron microscopy. After direct lysis of whole cells of S. faecalis F24 by lysozyme, protoplast membranes were isolated. It is concluded that, in the strain of group D streptococcus studied, lysozyme effectively removes the cell wall. Images PMID:13968087

  11. Structure of a conjugative element in Streptococcus pneumoniae

    SciTech Connect

    Vijayakumar, M.N.; Priebe, S.D.; Guild, W.R.

    1986-06-01

    The authors have cloned and mapped a 69-kilobase (kb) region of the chromosome of Streptococcus pneumoniae DP1322, which carries the conjugative Omega(cat-tet) insertion from S. pneumoniae BM6001. This element proved to be 65.5 kb in size. Location of the junctions was facilitated by cloning a preferred target region from the wild-type strain Rx1 recipient genome. This target site was preferred by both the BM6001 element and the cat-erm-tet element from Streptococcus agalactiae B109. Within the BM6001 element cat and tet were separated by 30 kb, and cat was flanked by two copies of a sequence that was also present in the recipient strain Rx1 DNA. Another sequence at least 2.4 kb in size was found inside the BM6001 element and at two places in the Rx1 genome. Its role is unknown. The ends of the BM6001 element appear to be the same as those of the B109 element, both as seen after transfer to S. pneumoniae and as mapped by others in pDP5 after transposition in Streptococcus faecalis. No homology is seen between the ends of the BM6001 element and no evidence found suggesting that it ever circularizes.

  12. Antimicrobial activity of commercially available essential oils against Streptococcus mutans.

    PubMed

    Chaudhari, Lalit Kumar D; Jawale, Bhushan Arun; Sharma, Sheeba; Sharma, Hemant; Kumar, C D Mounesh; Kulkarni, Pooja Adwait

    2012-01-01

    Many essential oils have been advocated for use in complementary medicine for bacterial and fungal infections. However, few of the many claims of therapeutic efficacy have been validated adequately by either in vitro testing or in vivo clinical trials. To study the antibacterial activity of nine commercially available essential oils against Streptococcus mutans in vitro and to compare the antibacterial activity between each material. Nine pure essential oils; wintergreen oil, lime oil, cinnamon oil, spearmint oil, peppermint oil, lemongrass oil, cedarwood oil, clove oil and eucalyptus oil were selected for the study. Streptococcus mutans was inoculated at 37ºC and seeded on blood agar medium. Agar well diffusion assay was used to measure antibacterial activity. Zone of inhibition was measured around the filter paper in millimeters with vernier caliper. Cinnamon oil showed highest activity against Streptococcus mutans followed by lemongrass oil and cedarwood oil. Wintergreen oil, lime oil, peppermint oil and spearmint oil showed no antibacterial activity. Cinnamon oil, lemongrass oil, cedarwood oil, clove oil and eucalyptus oil exhibit antibacterial property against S. mutans. The use of these essential oils against S. mutans can be a viable alternative to other antibacterial agents as these are an effective module used in the control of both bacteria and yeasts responsible for oral infections.

  13. Antibacterial activity and mechanism of berberine against Streptococcus agalactiae

    PubMed Central

    Peng, Lianci; Kang, Shuai; Yin, Zhongqiong; Jia, Renyong; Song, Xu; Li, Li; Li, Zhengwen; Zou, Yuanfeng; Liang, Xiaoxia; Li, Lixia; He, Changliang; Ye, Gang; Yin, Lizi; Shi, Fei; Lv, Cheng; Jing, Bo

    2015-01-01

    The antibacterial activity and mechanism of berberine against Streptococcus agalactiae were investigated in this study by analyzing the growth, morphology and protein of the S. agalactiae cells treated with berberine. The antibacterial susceptibility test result indicated minimum inhibition concentration (MIC) of berberine against Streptococcus agalactiae was 78 μg/mL and the time-kill curves showed the correlation of concentration-time. After the bacteria was exposed to 78 μg/mL berberine, the fragmentary cell membrane and cells unequal division were observed by the transmission electron microscopy (TEM), indicating the bacterial cells were severely damaged. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) study demonstrated that berberine could damage bacterial cells through destroying cellular proteins. Meanwhile, Fluorescence microscope revealed that berberine could affect the synthesis of DNA. In conclusion, these results strongly suggested that berberine may damage the structure of bacterial cell membrane and inhibit synthesis of protein and DNA, which cause Streptococcus agalactiae bacteria to die eventually. PMID:26191220

  14. Antibacterial activity and mechanism of berberine against Streptococcus agalactiae.

    PubMed

    Peng, Lianci; Kang, Shuai; Yin, Zhongqiong; Jia, Renyong; Song, Xu; Li, Li; Li, Zhengwen; Zou, Yuanfeng; Liang, Xiaoxia; Li, Lixia; He, Changliang; Ye, Gang; Yin, Lizi; Shi, Fei; Lv, Cheng; Jing, Bo

    2015-01-01

    The antibacterial activity and mechanism of berberine against Streptococcus agalactiae were investigated in this study by analyzing the growth, morphology and protein of the S. agalactiae cells treated with berberine. The antibacterial susceptibility test result indicated minimum inhibition concentration (MIC) of berberine against Streptococcus agalactiae was 78 μg/mL and the time-kill curves showed the correlation of concentration-time. After the bacteria was exposed to 78 μg/mL berberine, the fragmentary cell membrane and cells unequal division were observed by the transmission electron microscopy (TEM), indicating the bacterial cells were severely damaged. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) study demonstrated that berberine could damage bacterial cells through destroying cellular proteins. Meanwhile, Fluorescence microscope revealed that berberine could affect the synthesis of DNA. In conclusion, these results strongly suggested that berberine may damage the structure of bacterial cell membrane and inhibit synthesis of protein and DNA, which cause Streptococcus agalactiae bacteria to die eventually.

  15. Six-Month Multicenter Study on Invasive Infections Due to Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis in Argentina

    PubMed Central

    Lopardo, Horacio A.; Vidal, Patricia; Sparo, Monica; Jeric, Paola; Centron, Daniela; Facklam, Richard R.; Paganini, Hugo; Pagniez, N. Gaston; Lovgren, Marguerite; Beall, Bernard

    2005-01-01

    During a 6-month period, 95 invasive infections due to Streptococcus pyogenes and group C or group G Streptococcus dysgalactiae subsp. equisimilis were recorded from 40 centers of 16 cities in Argentina. We describe here epidemiologic data available for 55 and 19 patients, respectively, associated with invasive infections due to S. pyogenes and S. dysgalactiae subsp. equisimilis. The associated isolates and 58 additional pharyngeal isolates were genotyped and subjected to serologic and/or antibiotic susceptibility testing. Group A streptococcal emm type distribution and strain association with toxic shock appeared to differ somewhat from results found within the United States; however, serologic characterization and sof sequence typing suggested that emm types found in both countries are reflective of shared clonal types. PMID:15695683

  16. Survival of Streptococcus suis, Streptococcus dysgalactiae and Trueperella pyogenes in dry-cured Iberian pork shoulders and loins.

    PubMed

    Cardoso-Toset, F; Luque, I; Morales-Partera, A; Galán-Relaño, A; Barrero-Domínguez, B; Hernández, M; Gómez-Laguna, J

    2017-02-01

    Dry-cured hams, shoulders and loins of Iberian pigs are highly appreciated in national and international markets. Salting, additive addition and dehydration are the main strategies to produce these ready-to-eat products. Although the dry curing process is known to reduce the load of well-known food borne pathogens, studies evaluating the viability of other microorganisms in contaminated pork have not been performed. In this work, the efficacy of the dry curing process to eliminate three swine pathogens associated with pork carcass condemnation, Streptococcus suis, Streptococcus dysgalactiae and Trueperella pyogenes, was evaluated. Results of this study highlight that the dry curing process is a suitable method to obtain safe ready-to-eat products free of these microorganisms. Although salting of dry-cured shoulders had a moderate bactericidal effect, results of this study suggest that drying and ripening were the most important stages to obtain dry-cured products free of these microorganisms.

  17. [Description of 3 cases of skin and soft tissue infections caused by Streptococcus pneumoniae].

    PubMed

    Martínez, Mónica Elisabeth; Grenón, Sandra Liliana; López, Oscar Herminio; Leguizamón, Lorena Beatriz; Mollerach, Marta Eugenia; von Specht, Martha Helena

    The role of Streptococcus pneumoniae as a causative agent of skin and soft tissue infections (SSTI) is unusual and its clinical interpretation is difficult. We describe here three cases of SSTI due to S. pneumoniae in patients admitted to the Provincial Pediatric Hospital of Misiones, Argentina that were detected during 10 years of invasive disease (ID) surveillance documented in 2010, 2011 and 2015. These cases involved two girls aged 8 and 7 months old, and a two-year-old male child with diagnoses of gluteal abscess, preseptal cellulites and pyoderma respectively. All the patients were eutrophic and in good general condition on admission; one of them was seropositive for HIV. Antimicrobial susceptibility and serotypes were framed within the local epidemiology of invasive pneumococcal disease. Despite its low frequency, S. pneumoniae as an etiological agent of SSTI must be considered. Our findings revalue the role of the diagnostic laboratory and contribute to document the behavior of this pathogen. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. The thioredoxin system in the dental caries pathogen Streptococcus mutans and the food-industry bacterium Streptococcus thermophilus.

    PubMed

    Marco, Salvatore; Rullo, Rosario; Albino, Antonella; Masullo, Mariorosario; De Vendittis, Emmanuele; Amato, Massimo

    2013-11-01

    The Streptococcus genus includes the pathogenic species Streptococcus mutans, the main responsible of dental caries, and the safe microorganism Streptococcus thermophilus, used for the manufacture of dairy products. These facultative anaerobes control the levels of reactive oxygen species (ROS) and indeed, both S. mutans and S. thermophilus possess a cambialistic superoxide dismutase, the key enzyme for a preventive action against ROS. To evaluate the properties of a crucial mechanism for repairing ROS damages, the molecular and functional characterization of the thioredoxin system in these streptococci was investigated. The putative genes encoding its protein components in S. mutans and S. thermophilus were analysed and the corresponding recombinant proteins were purified. A single thioredoxin reductase was obtained from either S. mutans (SmTrxB) or S. thermophilus (StTrxB1), whereas two thioredoxins were prepared from either S. mutans (SmTrxA and SmTrxH1) or S. thermophilus (StTrxA1 and StTrxA2). Both SmTrxB and StTrxB1 reduced the synthetic substrate DTNB in the presence of NADPH, whereas only SmTrxA and StTrxA1 accelerated the insulin reduction in the presence of DTT. To reconstitute an in vitro streptococcal thioredoxin system, the combined activity of the thioredoxin components was tested through the insulin precipitation in the absence of DTT. The assay functions with a combination of SmTrxB or StTrxB1 with either SmTrxA or StTrxA1. These results suggest that the streptococcal members of the thioredoxin system display a direct functional interaction between them and that these protein components are interchangeable within the Streptococcus genus. In conclusion, our data prove the existence of a functioning thioredoxin system even in these microaerophiles.

  19. Transduction of the Streptococcus pyogenes bacteriophage Φm46.1, carrying resistance genes mef(A) and tet(O), to other Streptococcus species.

    PubMed

    Giovanetti, Eleonora; Brenciani, Andrea; Morroni, Gianluca; Tiberi, Erika; Pasquaroli, Sonia; Mingoia, Marina; Varaldo, Pietro E

    2014-01-01

    Φm46.1 - Streptococcus pyogenes bacteriophage carrying mef(A) and tet(O), respectively, encoding resistance to macrolides (M phenotype) and tetracycline - is widespread in S. pyogenes but has not been reported outside this species. Φm46.1 is transferable in vitro among S. pyogenes isolates, but no information is available about its transferability to other Streptococcus species. We thus investigated Φm46.1 for its ability to be transduced in vitro to recipients of different Streptococcus species. Transductants were obtained from recipients of Streptococcus agalactiae, Streptococcus gordonii, and Streptococcus suis. Retransfer was always achieved, and from S. suis to S. pyogenes occurred at a much greater frequency than in the opposite direction. In transductants Φm46.1 retained its functional properties, such as inducibility with mitomycin C, presence both as a prophage and as a free circular form, and transferability. The transductants shared the same Φm46.1 chromosomal integration site as the donor, at the 3' end of a conserved RNA uracil methyltransferase (rum) gene, which is an integration hotspot for a variety of genetic elements. No transfer occurred to recipients of Streptococcus pneumoniae, Streptococcus oralis, and Streptococcus salivarius, even though rum-like genes were also detected in the sequenced genomes of these species. A largely overlapping 18-bp critical sequence, where the site-specific recombination process presumably takes place, was identified in the rum genes of all recipients, including those of the species yielding no transductants. Growth assays to evaluate the fitness cost of Φm46.1 acquisition disclosed a negligible impact on S. pyogenes, S. agalactiae, and S. gordonii transductants and a noticeable fitness advantage in S. suis. The S. suis transductant also displayed marked overexpression of the autolysin-encoding gene atl.

  20. Streptococcus caviae sp. nov., isolated from guinea pig faecal samples.

    PubMed

    Palakawong Na Ayudthaya, Susakul; Hilderink, Loes J; Oost, John van der; Vos, Willem M de; Plugge, Caroline M

    2017-05-01

    A novel cellobiose-degrading and lactate-producing bacterium, strain Cavy grass 6T, was isolated from faecal samples of guinea pigs (Cavia porcellus). Cells of the strain were ovalshaped, non-motile, non-spore-forming, Gram-stain-positive and facultatively anaerobic. The strain gr at 25-40 °C (optimum 37 °C) and pH 4.5-9.5 (optimum 8.0). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Cavy grass 6T belongs to the genus Streptococcus with its closest relative being Streptococcus devriesei CCUG 47155T with only 96.5 % similarity. Comparing strain Cavy grass 6T and Streptococcus devriesei CCUG 47155T, average nucleotide identity and level of digital DNA-DNA hybridization dDDH were only 86.9 and 33.3 %, respectively. Housekeeping genes groEL and gyrA were different between strain Cavy grass 6T and other streptococci. The G+C content of strain Cavy grass 6T was 42.6±0.3 mol%. The major (>10 %) cellular fatty acids of strain Cavy grass 6T were C16:0, C20 : 1ω9c and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). Strain Cavy grass 6T ferment a range of plant mono- and disaccharides as well as polymeric carbohydrates, including cellobiose, dulcitol, d-glucose, maltose, raffinose, sucrose, l-sorbose, trehalose, inulin and dried grass extract, to lactate, formate, acetate and ethanol. Based on phylogenetic and physiological characteristics, Cavy grass 6T can be distinguished from other members of the genus Streptococcus. Therefore, a novel species of the genus Streptococcus, family Streptococcaceae, order Lactobacillales is proposed, Streptococcuscaviae sp. nov. (type strain Cavy grass 6T=TISTR 2371T=DSM 102819T).

  1. National Department of Defense Surveillance for Invasive Streptococcus Pneumoniae: Antibiotic Resistance, Serotype Distribution, and Arbitrarily Primed Polymerase Chain Reaction Analyses

    DTIC Science & Technology

    2008-02-15

    penicillin -susceptible and peni- cillin-resistant Streptococcnspneuttmoniae serotypes in Canada. J Infect Dis Streptococcus pneumoniae Surveillance Group...Gray for the Streptococcus pneumonia Surveillance Group Report No. 00-44 Approved for public release; distribution unlimited. NAVAL HEALTH RESEARCH...Defense Surveillance for Invasive Streptococcus pneumoniae : Antibiotic Resistance, Serotype Distribution, and Arbitrarily Primed Polymerase Chain

  2. Non-infectivity of Cattle Streptococcus agalactiae in Nile Tilapia, Oreochromis niloticus and Channel Catfish, Ictalurus punctatus

    USDA-ARS?s Scientific Manuscript database

    Streptococcus agalactiae is classified as a Lancefield’s group B Streptococcus (GBS). It is the causative bacterium of streptococcosis that is responsible for severe economic losses in wild and cultured fish, worldwide. Streptococcus agalactiae also causes bovine mastitis. Only limited comparativ...

  3. Re-evaluation of the taxonomy of the Mitis group of the genus Streptococcus based on whole genome phylogenetic analyses, and proposed reclassification of Streptococcus dentisani as Streptococcus oralis subsp. dentisani comb. nov., Streptococcus tigurinus as Streptococcus oralis subsp. tigurinus comb. nov., and Streptococcus oligofermentans as a later synonym of Streptococcus cristatus.

    PubMed

    Jensen, Anders; Scholz, Christian F P; Kilian, Mogens

    2016-11-01

    The Mitis group of the genus Streptococcus currently comprises 20 species with validly published names, including the pathogen S. pneumoniae. They have been the subject of much taxonomic confusion, due to phenotypic overlap and genetic heterogeneity, which has hampered a full appreciation of their clinical significance. The purpose of this study was to critically re-examine the taxonomy of the Mitis group using 195 publicly available genomes, including designated type strains for phylogenetic analyses based on core genomes, multilocus sequences and 16S rRNA gene sequences, combined with estimates of average nucleotide identity (ANI) and in silico and in vitro analyses of specific phenotypic characteristics. Our core genomic phylogenetic analyses revealed distinct clades that, to some extent, and from the clustering of type strains represent known species. However, many of the genomes have been incorrectly identified adding to the current confusion. Furthermore, our data show that 16S rRNA gene sequences and ANI are unsuitable for identifying and circumscribing new species of the Mitis group of the genus Streptococci. Based on the clustering patterns resulting from core genome phylogenetic analysis, we conclude that S. oligofermentans is a later synonym of S. cristatus. The recently described strains of the species Streptococcus dentisani includes one previously referred to as 'S. mitis biovar 2'. Together with S. oralis, S. dentisani and S. tigurinus form subclusters within a coherent phylogenetic clade. We propose that the species S. oralis consists of three subspecies: S. oralis subsp. oralis subsp. nov., S. oralis subsp. tigurinus comb. nov., and S. oralis subsp. dentisani comb. nov.

  4. Controlled laboratory challenge demonstrates substantial additive genetic variation in resistance to Streptococcus iniae in Nile tilapia

    USDA-ARS?s Scientific Manuscript database

    Streptococcus iniae is an etiologic agent of streptococcal disease in tilapia and is one of several Streptococcus spp. that negatively impact worldwide tilapia production. Methods for the prevention and control of S. iniae include vaccines, management strategies, and antibiotics. An alternative and ...

  5. The Host Immune Response to Streptococcus pneumoniae: Bridging Innate and Adaptive Immunity

    DTIC Science & Technology

    2006-07-06

    pneumoniae Epidemiology A major human pathogen, Streptococcus pneumoniae (Pn) is a Gram -positive facultative anaerobe. Originally named Diplococcus... peptidoglycan layer, as well as TA and LTA, form a matrix that provides elasticity, strength and structure to the bacterium. PC, besides acting as an...Figure 3. Important virulence factors of Streptococcus pneumoniae. Peptidoglycan , teichoic acid (TA), and lipoteichoic acid (LTA) provide strength and

  6. Nonhemolytic Streptococcus pyogenes Isolates That Lack Large Regions of the sag Operon Mediating Streptolysin S Production▿

    PubMed Central

    Yoshino, Miho; Murayama, Somay Y.; Sunaoshi, Katsuhiko; Wajima, Takeaki; Takahashi, Miki; Masaki, Junko; Kurokawa, Iku; Ubukata, Kimiko

    2010-01-01

    Among nonhemolytic Streptococcus pyogenes (group A streptococcus) strains (n = 9) isolated from patients with pharyngitis or acute otitis media, we identified three deletions in the region from the epf gene, encoding the extracellular matrix binding protein, to the sag operon, mediating streptolysin S production. PMID:20018818

  7. Identification of a pheA gene associated with Streptococcus mitis by using suppression subtractive hybridization.

    PubMed

    Park, Hee Kuk; Dang, Hien Thanh; Myung, Soon Chul; Kim, Wonyong

    2012-04-01

    We performed suppression subtractive hybridization to identify genomic differences between Streptococcus mitis and Streptococcus pneumoniae. Based on the pheA gene, a primer set specific to S. mitis detection was found in 18 out of 103 S. mitis-specific clones. Our findings would be useful for discrimination of S. mitis from other closely related cocci in the oral environment.

  8. 21 CFR 866.3720 - Streptococcus spp. exo-enzyme reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... spp. exo-enzyme reagents. (a) Identification. Streptococcus spp. exoenzyme reagents are devices used...

  9. 21 CFR 866.3720 - Streptococcus spp. exo-enzyme reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... spp. exo-enzyme reagents. (a) Identification. Streptococcus spp. exoenzyme reagents are devices used...

  10. 21 CFR 866.3720 - Streptococcus spp. exo-enzyme reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... spp. exo-enzyme reagents. (a) Identification. Streptococcus spp. exoenzyme reagents are devices used...

  11. 21 CFR 866.3720 - Streptococcus spp. exo-enzyme reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... spp. exo-enzyme reagents. (a) Identification. Streptococcus spp. exoenzyme reagents are devices used...

  12. 21 CFR 866.3720 - Streptococcus spp. exo-enzyme reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3720 Streptococcus spp. exo-enzyme reagents. (a) Identification. Streptococcus spp. exoenzyme reagents are devices used... information on these diseases. Pathogenic streptococci are associated with infections, such as sore...

  13. Hypopituitarism as consequence of late neonatal infection by Group B streptococcus: a case report

    PubMed Central

    Ferreira, Amanda Santana; Fernandes, Ana Lourdes Lima Araújo; Guaragna-Filho, Guilherme

    2015-01-01

    Hypopituitarism is a condition characterized by dysfunction of the pituitary gland hormone production. The insults of the perinatal period, which includes the late infection by Group B Streptococcus, consists in a rare etiology of this condition. We present the case of a 39-days-old infant with meningitis caused by Streptococcus Group B, which showed, among other consequences, hypopituitarism. PMID:26161231

  14. Complete Genome Sequence of Streptococcus iniae 89353, a Virulent Strain Isolated from Diseased Tilapia in Taiwan

    PubMed Central

    Wu, Sheng-Han; Chen, Chun-Yao; Huang, Chang-Wen; Lu, Jenn-Kan; Chou, Hsin-Yiu

    2017-01-01

    ABSTRACT Streptococcus iniae 89353 is a virulent strain isolated from diseased tilapia in Taiwan. The full-genome sequence of S. iniae 89353 is 2,098,647 bp. The revealed genome information will be beneficial for identification and understanding of potential virulence genes of Streptococcus iniae and possible immunogens for vaccine development against streptococcosis. PMID:28126946

  15. Draft Genome Sequence of Hypervirulent and Vaccine Candidate Streptococcus suis Strain SC19

    PubMed Central

    Teng, Lin; Dong, Xingxing; Zhou, Yang; Li, Zhiwei; Deng, Limei; Chen, Huanchun; Wang, Xiaohong

    2017-01-01

    ABSTRACT Streptococcus suis, a zoonotic bacterium found primarily in pigs, has been recognized recently as an emerging pathogen of humans. Herein, we describe the genome of Streptococcus suis strain SC19, a hypervirulent and vaccine candidate strain isolated from a pig amid the 2005 outbreak in China. PMID:28104658

  16. Hypopituitarism as consequence of late neonatal infection by Group B streptococcus: a case report.

    PubMed

    Ferreira, Amanda Santana; Fernandes, Ana Lourdes Lima Araújo; Guaragna-Filho, Guilherme

    2015-01-01

    Hypopituitarism is a condition characterized by dysfunction of the pituitary gland hormone production. The insults of the perinatal period, which includes the late infection by Group B Streptococcus, consists in a rare etiology of this condition. We present the case of a 39-days-old infant with meningitis caused by Streptococcus Group B, which showed, among other consequences, hypopituitarism.

  17. Molecular characterization of the presence of Eubacterium spp and Streptococcus spp in endodontic infections.

    PubMed

    Fouad, A F; Kum, K-Y; Clawson, M L; Barry, J; Abenoja, C; Zhu, Q; Caimano, M; Radolf, J D

    2003-08-01

    Eubacterium spp. and Streptococcus spp. are virulent, commonly identified microorganisms in endodontic infections. The purpose of this study was to use molecular methods to identify these organisms in 22 infected root canals that include eight cases with preoperative clinical symptoms and five cases with a history of diabetes mellitus. The presence of Streptococcus spp. and Eubacterium spp. was examined using two sets of PCR primers specific with multiple species within the respective genera. Positive specimens had their PCR products sequenced and phylogenetically analyzed to identify the specific species. Sixteen specimens (73%) contained Eubacterium spp. and nine (41%) were positive for Streptococcus spp. Eubacterium infirmum was the most prevalent Eubacterium sp. This organism was significantly associated with a history of diabetes (OR = 9.6; P = 0.04). Streptococcus anginosus was the most common Streptococcus sp., but neither it nor any of the other streptococci were significantly associated with the clinical parameters evaluated.

  18. Complete Genome Sequence of emm4 Streptococcus pyogenes MEW427, a Throat Isolate from a Child Meeting Clinical Criteria for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus (PANDAS).

    PubMed

    Jacob, Kristin M; Spilker, Theodore; LiPuma, John J; Dawid, Suzanne R; Watson, Michael E

    2016-03-17

    We report the complete genome assembly of the Streptococcus pyogenes type emm4 strain MEW427 (also referred to as strain UM001 in the Pediatric Acute-Onset Neuropsychiatric Syndrome [PANS] Research Consortium), a throat isolate from a child with acute-onset neuropsychiatric symptoms meeting clinical criteria for PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcus). The genome length is 1,814,455 bp with 38.51% G+C%. Copyright © 2016 Jacob et al.

  19. Association of Streptococcus pluranimalium with valvular endocarditis and septicaemia in adult broiler parents.

    PubMed

    Hedegaard, L; Christensen, H; Chadfield, M S; Christensen, J P; Bisgaard, M

    2009-04-01

    The genus Streptococcus consists of more than 60 species, but only Streptococcus equi subspecies zooepidemicus, Streptococcus gallolyticus ssp. gallolyticus, Streptococcus gallinaceus, Streptococcus dysgalactiae, Streptococcus mutans and Streptococcus suis have been isolated from poultry. During investigations of the aetiology of increased mortality in broiler parent stock at the end of production, pure cultures of streptococcal-like organisms that could not be classified among these six species were obtained from 24 cases of septicaemia or valvular endocarditis and septicaemia. Phenotypic characterization using the API20 STREP kit identified the isolates as Aerococcus viridans (10), Aerococcus urinae (2), Leuconostoc species (4), Streptococcus salivarius (2), Streptococcus bovis II 3 (1), Enterococcus avium (3), Enterococcus faecium (1) or Gemella morbillorum (1). However, this identification was misleading as subsequent genetic investigations using pulse field gel electrophoresis and sequencing of 16S rRNA genes showed that 19 isolates were classified as Streptococcus pluranimalium, while the remaining isolates were E. avium (3), E. faecium (1) or Lactobacillus species (1). Misidentification by API20 STREP was related to the database provided by the manufacturer, as the phenotypic characteristics could identify these organisms as S. pluranimalium. The isolates of S. pluranimalium belonged to at least three different clones as determined by pulsed field gel electrophoresis of SmaI-digested genomic DNA. The capacity that these isolates had to colonize the valvular endothelium was suggested by the occurrence of valvular endocarditis in 12 of 19 cases. Demonstration of the same clone in all four houses on a farm suggested the pathogenic potential of this organism.

  20. Group C Streptococcus Causing Rheumatic Heart Disease in a Child.

    PubMed

    Chandnani, Harsha K; Jain, Renu; Patamasucon, Pisespong

    2015-07-01

    Human infection with group C Streptococcus is extremely rare and a select number of cases have been reported to cause acute pharyngitis, acute glomerulonephritis, skin and soft tissue infections, septic arthritis, osteomyelitis, pneumonitis, and bacteremia. In pediatrics, this bacteria is known to cause epidemic food-borne pharyngitis, pneumonia, endocarditis, and meningitis, and has reportedly been isolated in the blood, meninges, sinuses, fingernail, peritonsillar abscess, and thyroglossal duct cyst, among others. Our patient was a 7-year-old previously healthy female who presented with abnormal movements of her upper body and grimaces of her face that progressively worsened over time. Initial laboratory resulted revealed 3+ protein on urinalysis and elevated antistreptolysin-O and anti-DNAse antibody levels, and echocardiogram showed mild-to-moderate mitral regurgitation. We describe a rare case of group C Streptococcus resulting in rheumatic heart disease in a child, with a detailed review of the literature pertaining to the diagnosis and management of this infection. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Early recognition of rheumatic heart disease is crucial in the overall outcome of the condition and therefore knowledge of the symptoms associated with condition is also imperative. Group C Streptococcus is rarely associated with rheumatic heart disease and most children exhibiting acute onset of common symptoms, such as chorea, fever, carditis, and rash (erythema marginatum) will present to the emergency department first. Increased awareness and prompt recognition, as done with this child, will result in proper follow-up and adequate management of this condition in all patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Human Streptococcus agalactiae strains in aquatic mammals and fish.

    PubMed

    Delannoy, Christian M J; Crumlish, Margaret; Fontaine, Michael C; Pollock, Jolinda; Foster, Geoff; Dagleish, Mark P; Turnbull, James F; Zadoks, Ruth N

    2013-02-18

    In humans, Streptococcus agalactiae or group B streptococcus (GBS) is a frequent coloniser of the rectovaginal tract, a major cause of neonatal infectious disease and an emerging cause of disease in non-pregnant adults. In addition, Streptococcus agalactiae causes invasive disease in fish, compromising food security and posing a zoonotic hazard. We studied the molecular epidemiology of S. agalactiae in fish and other aquatic species to assess potential for pathogen transmission between aquatic species and humans. Isolates from fish (n = 26), seals (n = 6), a dolphin and a frog were characterized by pulsed-field gel electrophoresis, multilocus sequence typing and standardized 3-set genotyping, i.e. molecular serotyping and profiling of surface protein genes and mobile genetic elements. Four subpopulations of S. agalactiae were identified among aquatic isolates. Sequence type (ST) 283 serotype III-4 and its novel single locus variant ST491 were detected in fish from Southeast Asia and shared a 3-set genotype identical to that of an emerging ST283 clone associated with invasive disease of adult humans in Asia. The human pathogenic strain ST7 serotype Ia was also detected in fish from Asia. ST23 serotype Ia, a subpopulation that is normally associated with human carriage, was found in all grey seals, suggesting that human effluent may contribute to microbial pollution of surface water and exposure of sea mammals to human pathogens. The final subpopulation consisted of non-haemolytic ST260 and ST261 serotype Ib isolates, which belong to a fish-associated clonal complex that has never been reported from humans. The apparent association of the four subpopulations of S. agalactiae with specific groups of host species suggests that some strains of aquatic S. agalactiae may present a zoonotic or anthroponotic hazard. Furthermore, it provides a rational framework for exploration of pathogenesis and host-associated genome content of S. agalactiae strains.

  2. Genomics of Streptococcus salivarius, a major human commensal.

    PubMed

    Delorme, Christine; Abraham, Anne-Laure; Renault, Pierre; Guédon, Eric

    2015-07-01

    The salivarius group of streptococci is of particular importance for humans. This group consists of three genetically similar species, Streptococcus salivarius, Streptococcus vestibularis and Streptococcus thermophilus. S. salivarius and S. vestibularis are commensal organisms that may occasionally cause opportunistic infections in humans, whereas S. thermophilus is a food bacterium widely used in dairy production. We developed Multilocus sequence typing (MLST) and comparative genomic analysis to confirm the clear separation of these three species. These analyses also identified a subgroup of four strains, with a core genome diverging by about 10%, in terms of its nucleotide sequence, from that of S. salivarius sensu stricto. S. thermophilus species displays a low level of nucleotide variability, due to its recent emergence with the development of agriculture. By contrast, nucleotide variability is high in the other two species of the salivarius group, reflecting their long-standing association with humans. The species of the salivarius group have genome sizes ranging from the smallest (∼ 1.7 Mb for S. thermophilus) to the largest (∼ 2.3 Mb for S. salivarius) among streptococci, reflecting genome reduction linked to a narrow, nutritionally rich environment for S. thermophilus, and natural, more competitive niches for the other two species. Analyses of genomic content have indicated that the core genes of S. salivarius account for about two thirds of the genome, indicating considerable variability of gene content and differences in potential adaptive features. Furthermore, we showed that the genome of this species is exceptionally rich in genes encoding surface factors, glycosyltransferases and response regulators. Evidence of widespread genetic exchanges was obtained, probably involving a natural competence system and the presence of diverse mobile elements. However, although the S. salivarius strains studied were isolated from several human body-related sites

  3. Human Streptococcus agalactiae strains in aquatic mammals and fish

    PubMed Central

    2013-01-01

    Background In humans, Streptococcus agalactiae or group B streptococcus (GBS) is a frequent coloniser of the rectovaginal tract, a major cause of neonatal infectious disease and an emerging cause of disease in non-pregnant adults. In addition, Streptococcus agalactiae causes invasive disease in fish, compromising food security and posing a zoonotic hazard. We studied the molecular epidemiology of S. agalactiae in fish and other aquatic species to assess potential for pathogen transmission between aquatic species and humans. Methods Isolates from fish (n = 26), seals (n = 6), a dolphin and a frog were characterized by pulsed-field gel electrophoresis, multilocus sequence typing and standardized 3-set genotyping, i.e. molecular serotyping and profiling of surface protein genes and mobile genetic elements. Results Four subpopulations of S. agalactiae were identified among aquatic isolates. Sequence type (ST) 283 serotype III-4 and its novel single locus variant ST491 were detected in fish from Southeast Asia and shared a 3-set genotype identical to that of an emerging ST283 clone associated with invasive disease of adult humans in Asia. The human pathogenic strain ST7 serotype Ia was also detected in fish from Asia. ST23 serotype Ia, a subpopulation that is normally associated with human carriage, was found in all grey seals, suggesting that human effluent may contribute to microbial pollution of surface water and exposure of sea mammals to human pathogens. The final subpopulation consisted of non-haemolytic ST260 and ST261 serotype Ib isolates, which belong to a fish-associated clonal complex that has never been reported from humans. Conclusions The apparent association of the four subpopulations of S. agalactiae with specific groups of host species suggests that some strains of aquatic S. agalactiae may present a zoonotic or anthroponotic hazard. Furthermore, it provides a rational framework for exploration of pathogenesis and host-associated genome content of S

  4. Streptococcus oralis Neuraminidase Modulates Adherence to Multiple Carbohydrates on Platelets.

    PubMed

    Singh, Anirudh K; Woodiga, Shireen A; Grau, Margaret A; King, Samantha J

    2017-03-01

    Adherence to host surfaces is often mediated by bacterial binding to surface carbohydrates. Although it is widely appreciated that some bacterial species express glycosidases, previous studies have not considered whether bacteria bind to multiple carbohydrates within host glycans as they are modified by bacterial glycosidases. Streptococcus oralis is a leading cause of subacute infective endocarditis. Binding to platelets is a critical step in disease; however, the mechanisms utilized by S. oralis remain largely undefined. Studies revealed that S. oralis, like Streptococcus gordonii and Streptococcus sanguinis, binds platelets via terminal sialic acid. However, unlike those organisms, S. oralis produces a neuraminidase, NanA, which cleaves terminal sialic acid. Further studies revealed that following NanA-dependent removal of terminal sialic acid, S. oralis bound exposed β-1,4-linked galactose. Adherence to both these carbohydrates required Fap1, the S. oralis member of the serine-rich repeat protein (SRRP) family of adhesins. Mutation of a conserved residue required for sialic acid binding by other SRRPs significantly reduced platelet binding, supporting the hypothesis that Fap1 binds this carbohydrate. The mechanism by which Fap1 contributes to β-1,4-linked galactose binding remains to be defined; however, binding may occur via additional domains of unknown function within the nonrepeat region, one of which shares some similarity with a carbohydrate binding module. This study is the first demonstration that an SRRP is required to bind β-1,4-linked galactose and the first time that one of these adhesins has been shown to be required for binding of multiple glycan receptors. Copyright © 2017 American Society for Microbiology.

  5. Streptococcus oralis Neuraminidase Modulates Adherence to Multiple Carbohydrates on Platelets

    PubMed Central

    Singh, Anirudh K.; Woodiga, Shireen A.; Grau, Margaret A.

    2016-01-01

    ABSTRACT Adherence to host surfaces is often mediated by bacterial binding to surface carbohydrates. Although it is widely appreciated that some bacterial species express glycosidases, previous studies have not considered whether bacteria bind to multiple carbohydrates within host glycans as they are modified by bacterial glycosidases. Streptococcus oralis is a leading cause of subacute infective endocarditis. Binding to platelets is a critical step in disease; however, the mechanisms utilized by S. oralis remain largely undefined. Studies revealed that S. oralis, like Streptococcus gordonii and Streptococcus sanguinis, binds platelets via terminal sialic acid. However, unlike those organisms, S. oralis produces a neuraminidase, NanA, which cleaves terminal sialic acid. Further studies revealed that following NanA-dependent removal of terminal sialic acid, S. oralis bound exposed β-1,4-linked galactose. Adherence to both these carbohydrates required Fap1, the S. oralis member of the serine-rich repeat protein (SRRP) family of adhesins. Mutation of a conserved residue required for sialic acid binding by other SRRPs significantly reduced platelet binding, supporting the hypothesis that Fap1 binds this carbohydrate. The mechanism by which Fap1 contributes to β-1,4-linked galactose binding remains to be defined; however, binding may occur via additional domains of unknown function within the nonrepeat region, one of which shares some similarity with a carbohydrate binding module. This study is the first demonstration that an SRRP is required to bind β-1,4-linked galactose and the first time that one of these adhesins has been shown to be required for binding of multiple glycan receptors. PMID:27993975

  6. YMC-2011, a Temperate Phage of Streptococcus salivarius 57.I.

    PubMed

    Chou, Wen-Chun; Huang, Szu-Chuan; Chiu, Cheng-Hsun; Chen, Yi-Ywan M

    2017-03-15

    Streptococcus salivarius is an abundant isolate of the oral cavity. The genome of S. salivarius 57.I consists of a 2-Mb chromosome and a 40,758-bp circular molecule, designated YMC-2011. Annotation of YMC-2011 revealed 55 open reading frames, most of them associated with phage production, although plaque formation is not observed in S. salivarius 57.I after lytic induction using mitomycin C. Results from Southern hybridization and quantitative real-time PCR confirmed that YMC-2011 exists extrachromosomally, with an estimated copy number of 3 to 4. Phage particles were isolated from the supernatant of mitomycin C-treated S. salivarius 57.I cultures, and transmission electron microscopic examination indicated that YMC-2011 belongs to the Siphoviridae family. Phylogenetic analysis suggests that phage YMC-2011 and the cos-type phages of Streptococcus thermophilus originated from a common ancestor. An extended -10 element (p L ) and a σ(70)-like promoter (p R ) were mapped 5' to Ssal_phage00013 (encoding a CI-like repressor) and Ssal_phage00014 (encoding a hypothetical protein), respectively, using 5' rapid amplification of cDNA ends, indicating that YMC-2011 transcribes at least two mRNAs in opposite orientations. Studies using promoter-chloramphenicol acetyltransferase reporter gene fusions revealed that p R , but not p L , was sensitive to mitomycin C induction, suggesting that the switch from lysogenic growth to lytic growth was controlled mainly by the activity of these two promoters. In conclusion, a lysogenic state is maintained in S. salivarius 57.I, presumably by the repression of genes encoding proteins for lytic growth.IMPORTANCE The movement of mobile genetic elements such as bacteriophages and the establishment of lysogens may have profound effects on the balance of microbial ecology where lysogenic bacteria reside. The discovery of phage YMC-2011 from Streptococcus salivarius 57.I suggests that YMC-2011 and Streptococcus thermophilus-infecting phages

  7. YMC-2011, a Temperate Phage of Streptococcus salivarius 57.I

    PubMed Central

    Chou, Wen-Chun; Huang, Szu-Chuan; Chiu, Cheng-Hsun

    2017-01-01

    ABSTRACT Streptococcus salivarius is an abundant isolate of the oral cavity. The genome of S. salivarius 57.I consists of a 2-Mb chromosome and a 40,758-bp circular molecule, designated YMC-2011. Annotation of YMC-2011 revealed 55 open reading frames, most of them associated with phage production, although plaque formation is not observed in S. salivarius 57.I after lytic induction using mitomycin C. Results from Southern hybridization and quantitative real-time PCR confirmed that YMC-2011 exists extrachromosomally, with an estimated copy number of 3 to 4. Phage particles were isolated from the supernatant of mitomycin C-treated S. salivarius 57.I cultures, and transmission electron microscopic examination indicated that YMC-2011 belongs to the Siphoviridae family. Phylogenetic analysis suggests that phage YMC-2011 and the cos-type phages of Streptococcus thermophilus originated from a common ancestor. An extended −10 element (pL) and a σ70-like promoter (pR) were mapped 5′ to Ssal_phage00013 (encoding a CI-like repressor) and Ssal_phage00014 (encoding a hypothetical protein), respectively, using 5′ rapid amplification of cDNA ends, indicating that YMC-2011 transcribes at least two mRNAs in opposite orientations. Studies using promoter-chloramphenicol acetyltransferase reporter gene fusions revealed that pR, but not pL, was sensitive to mitomycin C induction, suggesting that the switch from lysogenic growth to lytic growth was controlled mainly by the activity of these two promoters. In conclusion, a lysogenic state is maintained in S. salivarius 57.I, presumably by the repression of genes encoding proteins for lytic growth. IMPORTANCE The movement of mobile genetic elements such as bacteriophages and the establishment of lysogens may have profound effects on the balance of microbial ecology where lysogenic bacteria reside. The discovery of phage YMC-2011 from Streptococcus salivarius 57.I suggests that YMC-2011 and Streptococcus thermophilus

  8. Evaluation of universal antenatal screening for group B streptococcus.

    PubMed

    Van Dyke, Melissa K; Phares, Christina R; Lynfield, Ruth; Thomas, Ann R; Arnold, Kathryn E; Craig, Allen S; Mohle-Boetani, Janet; Gershman, Ken; Schaffner, William; Petit, Susan; Zansky, Shelley M; Morin, Craig A; Spina, Nancy L; Wymore, Kathryn; Harrison, Lee H; Shutt, Kathleen A; Bareta, Joseph; Bulens, Sandra N; Zell, Elizabeth R; Schuchat, Anne; Schrag, Stephanie J

    2009-06-18

    Group B streptococcal disease is one of the most common infections in the first week after birth. In 2002, national guidelines recommended universal late antenatal screening of pregnant women for colonization with group B streptococcus to identify candidates for intrapartum chemoprophylaxis. We evaluated the implementation of the guidelines in a multistate, retrospective cohort selected from the Active Bacterial Core surveillance, a 10-state, population-based system that monitors invasive group B streptococcal disease. We abstracted data from the labor and delivery records of a stratified random sample of live births and of all cases in which the newborn had early-onset group B streptococcal disease (i.e., disease in infants <7 days of age) in 2003 and 2004. We compared our results with those from a study with a similar design that evaluated screening practices in 1998 and 1999. We abstracted records of 254 births in which the infant had group B streptococcal disease and 7437 births in which the infant did not. The rate of screening for group B streptococcus before delivery increased from 48.1% in 1998-1999 to 85.0% in 2003-2004; the percentage of infants exposed to intrapartum antibiotics increased from 26.8% to 31.7%. Chemoprophylaxis was administered in 87.0% of the women who were positive for group B streptococcus and who delivered at term, but in only 63.4% of women with unknown colonization status who delivered preterm. The overall incidence of early-onset group B streptococcal disease was 0.32 cases per 1000 live births. Preterm infants had a higher incidence of early-onset group B streptococcal disease than did term infants (0.73 vs. 0.26 cases per 1000 live births); however, 74.4% of the cases of group B streptococcal disease (189 of 254) occurred in term infants. Missed screening among mothers who delivered at term accounted for 34 of the 254 cases of group B streptococcal disease (13.4%). A total of 61.4% of the term infants with group B streptococcal

  9. Ecology of Streptococcus faecium bacteriophage in chicken gut.

    PubMed Central

    Houghton, S B; Fuller, R

    1980-01-01

    The interaction in the chick gut between Streptococcus faecium and its phage was examined. In conventional chicks, large numbers of S. faecium and phage were found in the cecum and smaller numbers were found in the anterior gut. In gnotobiotic chicks associated with S. faecium SY1 and its phage, there was no marked effect on bacterial numbers, but resistance to the phage rapidly developed. Depression of chick growth caused by S. faecium strain SY1 was partially reversed by its phage. Images PMID:7190368

  10. Improving the sensitivity of blood culture for Streptococcus pneumoniae.

    PubMed

    Saha, Samir; Darmstadt, Gary; Naheed, Aliya; Arifeen, Shams; Islam, Maksuda; Fatima, Kaniz; Breiman, Robert; Sack, David; Hamer, Davidson

    2011-06-01

    Isolation of Streptococcus pneumoniae is jeopardized by low sensitivity of blood culture, autolysis and contamination with fast-growing organism(s). We performed an immunochromatographic (ICT) test for S. pneumoniae on chocolatized blood culture bottles and also sub-cultured contaminated bottles on a selective medium, thus identifying an additional eight and three cases, respectively, and improving the detection of pneumococcus by 23% (48% vs. 59%). Prescreening of culture bottles in a blinded fashion could rationalize the use of ICT with ~99% accuracy. These two approaches can aid microbiology laboratories in resource-poor countries to substantially improve rates of detection of S. pneumoniae.

  11. Neonatal necrotizing fasciitis of the scrotum caused by Streptococcus agalactiae.

    PubMed

    Kuroda, Junpei; Inoue, Nobuaki; Satoh, Hiroyuki; Fukuzawa, Ryuji; Terakawa, Toshiro; Hasegawa, Yukihiro

    2015-04-01

    We herein describe the case of a 27-day-old male infant who was brought to the emergency room for intermittent crying, and swelling of the left scrotum. Based on the clinical findings, necrotizing fasciitis was suspected, and surgical intervention was successfully completed within a few hours of admission. Streptococcus agalactiae type Ia was cultured from the drained abscess, and was considered the causative pathogen. To our knowledge, this is the first report of neonatal necrotizing fasciitis caused by S. agalactiae. Prompt diagnosis and immediate surgical debridement are crucial in the initial management of this disease.

  12. First isolation of Streptococcus downei from human dental plaques.

    PubMed

    Yoo, So Young; Kim, Kwan-Joong; Lim, Seong-Hoon; Kim, Kwang-Won; Hwang, Ho-Keel; Min, Byung-Moo; Choe, Son-Jin; Kook, Joong-Ki

    2005-08-15

    In this study, we isolated four bacterial strains grown on mitis-salivarius sucrose bacitracin agar. The strains had similar biochemical characteristics to biotypes I or II of mutans streptococci. The four isolates were identified as Streptococcus downei by 16S rDNA and dextranase gene (dex) sequencing as well as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting dex. To our knowledge, this is the first report of the isolation and identification of S. downei from dental plaque in humans. The results suggest that S. downei can inhabit the human oral cavity.

  13. Isolation and some properties of fimbriae of oral Streptococcus intermedius.

    PubMed

    Yamaguchi, Taihei; Matsunoshita, Nobuko

    2004-07-01

    Streptococcus intermedius 1208-1 carried linear fiber-like fimbriae that extended radially from the cell surface. The fimbriae were isolated by pipetting and sonication and were purified by ammonium sulfate precipitation followed by a column chromatography series. Heat treatment in the presence of sodium dodecyl sulfate resulted in the dissociation into smaller molecules. Rabbit antiserum raised against the purified protein reacted with fimbriae on the surface of bacteria under immunogold staining. Serotype g or g-related strains produced the fimbriae and aggregated in human saliva. The aggregation was inhibited by the anti-fimbriae immunoglobulin Fab fragment or the purified fimbriae.

  14. Peritoneal culture alters Streptococcus pneumoniae protein profiles and virulence properties

    NASA Technical Reports Server (NTRS)

    Orihuela, C. J.; Janssen, R.; Robb, C. W.; Watson, D. A.; Niesel, D. W.

    2000-01-01

    We have examined the properties of Streptococcus pneumoniae cultured in the murine peritoneal cavity and compared its virulence-associated characteristics to those of cultures grown in vitro. Analysis of mRNA levels for specific virulence factors demonstrated a 2.8-fold increase in ply expression and a 2.2-fold increase in capA3 expression during murine peritoneal culture (MPC). Two-dimensional gels and immunoblots using convalescent-phase patient sera and murine sera revealed distinct differences in protein production in vivo (MPC). MPC-grown pneumococci adhered to A549 epithelial cell lines at levels 10-fold greater than those cultured in vitro.

  15. A Rare Cause of Primary Aortoenteric Fistula: Streptococcus parasanguinis Aortitis

    PubMed Central

    Rowe, Kyle; Munguti, Cyrus; Nassif, Imad

    2017-01-01

    Primary aortoenteric fistula is a rare cause of upper gastrointestinal bleed but can lead to significant mortality if the diagnosis is delayed. Aortitis, characterized by inflammation of the aortic wall, is a rare cause of aortoenteric fistula. We present a case report of a 72-year-old male patient with infectious aortoenteric fistula secondary to Streptococcus parasanguinis, along with a review of the literature. This case demonstrates the importance of early diagnosis and aggressive surgical treatment of aortoenteric fistulae and recognizing infectious aortitis as a potential etiology. PMID:28255476

  16. The Streptococcus pyogenes proteome: maps, virulence factors and vaccine candidates

    PubMed Central

    Dmitriev, Alexander V; Chaussee, Michael S

    2011-01-01

    Streptococcus pyogenes is an important cause of human morbidity and mortality worldwide. A wealth of genomic information related to this pathogen has facilitated exploration of the proteome, particularly in response to environmental conditions thought to mimic various aspects of pathogenesis. Proteomic approaches are also used to identify immunoreactive proteins for vaccine development and to identify proteins that may induce autoimmunity. These studies have revealed new mechanisms involved in regulating the S. pyogenes proteome, which has opened up new avenues in the study of S. pyogenes pathogenesis. This article describes the methods used, and progress being made towards characterizing the S. pyogenes proteome, including studies seeking to identify potential vaccine candidates. PMID:21073313

  17. Chromosome and cell wall segregation in Streptococcus faecium ATCC 9790

    SciTech Connect

    Higgins, M.L.; Glaser, D.; Dicker, D.T.; Zito, E.T.

    1989-01-01

    Segregation was studied by measuring the positions of autoradiographic grain clusters in chains formed from single cells containing on average less than one radiolabeled chromosome strand. The degree to which chromosomal and cell wall material cosegregated was quantified by using the methods of S. Cooper and M. Weinberger, dividing the number of chains labeled at the middle. This analysis indicated that in contrast to chromosomal segregation in Escherichia coli and, in some studies, to that in gram-positive rods, chromosomal segregation in Streptococcus faecium was slightly nonrandom and did not vary with growth rate. Results were not significantly affected by strand exchange. In contrast, labeled cell wall segregated predominantly nonrandomly.

  18. Peritoneal culture alters Streptococcus pneumoniae protein profiles and virulence properties

    NASA Technical Reports Server (NTRS)

    Orihuela, C. J.; Janssen, R.; Robb, C. W.; Watson, D. A.; Niesel, D. W.

    2000-01-01

    We have examined the properties of Streptococcus pneumoniae cultured in the murine peritoneal cavity and compared its virulence-associated characteristics to those of cultures grown in vitro. Analysis of mRNA levels for specific virulence factors demonstrated a 2.8-fold increase in ply expression and a 2.2-fold increase in capA3 expression during murine peritoneal culture (MPC). Two-dimensional gels and immunoblots using convalescent-phase patient sera and murine sera revealed distinct differences in protein production in vivo (MPC). MPC-grown pneumococci adhered to A549 epithelial cell lines at levels 10-fold greater than those cultured in vitro.

  19. Development of Streptococcus pneumoniae Vaccines Using Live Vectors

    PubMed Central

    Wang, Shifeng; Curtiss, Roy

    2014-01-01

    Streptococcus pneumoniae still causes severe morbidity and mortality worldwide, especially in young children and the elderly. Much effort has been dedicated to developing protein-based universal vaccines to conquer the current shortcomings of capsular vaccines and capsular conjugate vaccines, such as serotype replacement, limited coverage and high costs. A recombinant live vector vaccine delivering protective antigens is a promising way to achieve this goal. In this review, we discuss the researches using live recombinant vaccines, mainly live attenuated Salmonella and lactic acid bacteria, to deliver pneumococcal antigens. We also discuss both the limitations and the future of these vaccines. PMID:25309747

  20. Antibiotic Susceptibility of Streptococcus mutans: Comparison of Serotype Profiles

    PubMed Central

    Little, Wayne A.; Thomson, Lynn A.; Bowen, William H.

    1979-01-01

    A total of 82 strains of Streptococcus mutans representing serotypes a through g were tested for susceptibility to erythromycin, penicillin, methicillin, lincomycin, tetracycline, vancomycin, gentamicin, streptomycin, neomycin, kanamycin, bacitracin, and polymyxin B. Strains included stock cultures and isolates from human and animal dental plaque. Minimal inhibitory concentrations were determined by a broth-microdilution procedure. The major differences in antibiotic susceptibility observed among the serotypes resulted with antibiotics which act on the cell surface. Bacitracin was most active against serotype a strains and polymyxin B against serotype b strains. Serotypes a, d, and g were less susceptible than the other serotypes to methicillin. PMID:464571

  1. Streptococcus Pneumoniae Intracranial Abscess and Post-Infectious Vasculitis

    PubMed Central

    Lucas, Alexandra; Maung, Ko Ko; Ratts, Ryan

    2016-01-01

    Intracranial abscesses are rare complications of Streptococcus pneumoniae infections, and to our knowledge, there have been no case reports of post-infectious vasculitis developing in such patients. Here we describe the case of a 48-year-old post-splenectomy male who developed post-infectious vasculitis following S. pneumoniae otitis media complicated by mastoiditis, osteomyelitis, meningitis, and intracranial abscess. Clinicians ought to be aware of the possible adverse outcomes of invasive S. pneumoniae and the limitations of current treatment options. PMID:28191299

  2. A novel pheromone quorum-sensing system controls the development of natural competence in Streptococcus thermophilus and Streptococcus salivarius.

    PubMed

    Fontaine, Laetitia; Boutry, Céline; de Frahan, Marie Henry; Delplace, Brigitte; Fremaux, Christophe; Horvath, Philippe; Boyaval, Patrick; Hols, Pascal

    2010-03-01

    In streptococcal species, the key step of competence development is the transcriptional induction of comX, which encodes the alternative sigma factor sigma(X), which positively regulates genes necessary for DNA transformation. In Streptococcus species belonging to the mitis and mutans groups, induction of comX relies on the activation of a three-component system consisting of a secreted pheromone, a histidine kinase, and a response regulator. In Streptococcus thermophilus, a species belonging to the salivarius group, the oligopeptide transporter Ami is essential for comX expression under competence-inducing conditions. This suggests a different regulation pathway of competence based on the production and reimportation of a signal peptide. The objective of our work was to identify the main actors involved in the early steps of comX induction in S. thermophilus LMD-9. Using a transcriptomic approach, four highly induced early competence operons were identified. Among them, we found a Rgg-like regulator (Ster_0316) associated with a nonannotated gene encoding a 24-amino-acid hydrophobic peptide (Shp0316). Through genetic deletions, we showed that these two genes are essential for comX induction. Moreover, addition to the medium of synthetic peptides derived from the C-terminal part of Shp0316 restored comX induction and transformation of a Shp0316-deficient strain. These peptides also induced competence in S. thermophilus and Streptococcus salivarius strains that are poorly transformable or not transformable. Altogether, our results show that Ster_0316 and Shp0316, renamed ComRS, are the two members of a novel quorum-sensing system responsible for comX induction in species from the salivarius group, which differs from the classical phosphorelay three-component system identified previously in streptococci.

  3. A Novel Pheromone Quorum-Sensing System Controls the Development of Natural Competence in Streptococcus thermophilus and Streptococcus salivarius▿ †

    PubMed Central

    Fontaine, Laetitia; Boutry, Céline; de Frahan, Marie Henry; Delplace, Brigitte; Fremaux, Christophe; Horvath, Philippe; Boyaval, Patrick; Hols, Pascal

    2010-01-01

    In streptococcal species, the key step of competence development is the transcriptional induction of comX, which encodes the alternative sigma factor σX, which positively regulates genes necessary for DNA transformation. In Streptococcus species belonging to the mitis and mutans groups, induction of comX relies on the activation of a three-component system consisting of a secreted pheromone, a histidine kinase, and a response regulator. In Streptococcus thermophilus, a species belonging to the salivarius group, the oligopeptide transporter Ami is essential for comX expression under competence-inducing conditions. This suggests a different regulation pathway of competence based on the production and reimportation of a signal peptide. The objective of our work was to identify the main actors involved in the early steps of comX induction in S. thermophilus LMD-9. Using a transcriptomic approach, four highly induced early competence operons were identified. Among them, we found a Rgg-like regulator (Ster_0316) associated with a nonannotated gene encoding a 24-amino-acid hydrophobic peptide (Shp0316). Through genetic deletions, we showed that these two genes are essential for comX induction. Moreover, addition to the medium of synthetic peptides derived from the C-terminal part of Shp0316 restored comX induction and transformation of a Shp0316-deficient strain. These peptides also induced competence in S. thermophilus and Streptococcus salivarius strains that are poorly transformable or not transformable. Altogether, our results show that Ster_0316 and Shp0316, renamed ComRS, are the two members of a novel quorum-sensing system responsible for comX induction in species from the salivarius group, which differs from the classical phosphorelay three-component system identified previously in streptococci. PMID:20023010

  4. Molecular characterization of virulence genes of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus in equines

    PubMed Central

    Javed, R.; Taku, A. K.; Gangil, Rakhi; Sharma, R. K.

    2016-01-01

    Aim: The aim was to determine the occurrence of streptococci in equines in Jammu (R. S. Pura, Katra), characterization of Streptococci equi subsp. equi and Streptococcus equi subsp. zooepidemicus with respect to their virulence traits and to determine antibiotic sensitivity pattern of virulent Streptococcus isolates. Materials and Methods: A total of 96 samples were collected from both clinically affected animals (exhibiting signs of respiratory tract disease) and apparently healthy animals and were sent to laboratory. The organisms were isolated on Columbia nalidixic acid agar containing 5% sheep blood as well as on sheep blood agar and confirmed by cultural characteristics and biochemical tests. Molecular detection of Streptococcus was done directly from cultures using sodA and seM gene-based polymerase chain reaction (PCR). Antibiogram was performed against five antibiotics such as amoxicillin, penicillin G, streptomycin, rifampicin, and methicillin. Results: During this study, a total 40 streptococcal isolates were obtained out of which 2 isolates were of S. equi subsp. equi, 12 isolates were from S. equi subsp. zooepidemicus. In the PCR-based detection, we revealed amplicons of 235 bp and 679 bp for confirmation of sodA and seM gene, respectively. In antibiogram, two isolates of S. equi subsp. equi were found resistant to penicillin G, and all other isolates were found sensitive to amoxicillin and streptomycin. Conclusion: The majority of streptococcal infections was due to S. equi subsp. Zooepidemicus, and thus was recognized as a potential pathogen of diseases of equines besides S. equi subsp. equi. PMID:27651677

  5. Development of a multiplex PCR assay to detect Edwardsiella tarda, Streptococcus parauberis, and Streptococcus iniae in olive flounder (Paralichthys olivaceus).

    PubMed

    Park, Seong Bin; Kwon, Kyoung; Cha, In Seok; Jang, Ho Bin; Nho, Seong Won; Fagutao, Fernand F; Kim, Young Kyu; Yu, Jong Earn; Jung, Tae Sung

    2014-01-01

    A multiplex PCR protocol was established to simultaneously detect major bacterial pathogens in olive flounder (Paralichthys olivaceus) including Edwardsiella (E.) tarda, Streptococcus (S.) parauberis, and S. iniae. The PCR assay was able to detect 0.01 ng of E. tarda, 0.1 ng of S. parauberis, and 1 ng of S. iniae genomic DNA. Furthermore, this technique was found to have high specificity when tested with related bacterial species. This method represents a cheaper, faster, and reliable alternative for identifying major bacterial pathogens in olive flounder, the most important farmed fish in Korea.

  6. Phylogenomics and the Dynamic Genome Evolution of the Genus Streptococcus

    PubMed Central

    Richards, Vincent P.; Palmer, Sara R.; Pavinski Bitar, Paulina D.; Qin, Xiang; Weinstock, George M.; Highlander, Sarah K.; Town, Christopher D.; Burne, Robert A.; Stanhope, Michael J.

    2014-01-01

    The genus Streptococcus comprises important pathogens that have a severe impact on human health and are responsible for substantial economic losses to agriculture. Here, we utilize 46 Streptococcus genome sequences (44 species), including eight species sequenced here, to provide the first genomic level insight into the evolutionary history and genetic basis underlying the functional diversity of all major groups of this genus. Gene gain/loss analysis revealed a dynamic pattern of genome evolution characterized by an initial period of gene gain followed by a period of loss, as the major groups within the genus diversified. This was followed by a period of genome expansion associated with the origins of the present extant species. The pattern is concordant with an emerging view that genomes evolve through a dynamic process of expansion and streamlining. A large proportion of the pan-genome has experienced lateral gene transfer (LGT) with causative factors, such as relatedness and shared environment, operating over different evolutionary scales. Multiple gene ontology terms were significantly enriched for each group, and mapping terms onto the phylogeny showed that those corresponding to genes born on branches leading to the major groups represented approximately one-fifth of those enriched. Furthermore, despite the extensive LGT, several biochemical characteristics have been retained since group formation, suggesting genomic cohesiveness through time, and that these characteristics may be fundamental to each group. For example, proteolysis: mitis group; urea metabolism: salivarius group; carbohydrate metabolism: pyogenic group; and transcription regulation: bovis group. PMID:24625962

  7. Streptococcus mitis: walking the line between commensalism and pathogenesis.

    PubMed

    Mitchell, J

    2011-04-01

    Streptococcus mitis is a viridans streptococcus and a normal commensal of the human oropharynx. However, S. mitis can escape from this niche and cause a variety of infectious complications including infective endocarditis, bacteraemia and septicaemia. It uses a variety of strategies to effectively colonize the human oropharynx. These include expression of adhesins, immunoglobulin A proteases and toxins, and modulation of the host immune system. These various colonization factors allow S. mitis to compete for space and nutrients in the face of its more pathogenic oropharyngeal microbial neighbours. However, it is likely that in vulnerable immune-compromised patients S. mitis will use the same colonization and immune modulation factors as virulence factors promoting its opportunistic pathogenesis. The recent publication of a complete genome sequence for S. mitis strain B6 will allow researchers to thoroughly investigate which genes are involved in S. mitis host colonization and pathogenesis. Moreover, it will help to give insight into where S. mitis fits in the complicated oral microbiome. This review will discuss the current knowledge of S. mitis factors involved in host colonization, their potential role in virulence and what needs to be done to fully understand how a an oral commensal successfully transitions to a virulent pathogen.

  8. A molecular trigger for intercontinental epidemics of group A Streptococcus

    PubMed Central

    Zhu, Luchang; Olsen, Randall J.; Nasser, Waleed; Beres, Stephen B.; Vuopio, Jaana; Kristinsson, Karl G.; Gottfredsson, Magnus; Porter, Adeline R.; DeLeo, Frank R.; Musser, James M.

    2015-01-01

    The identification of the molecular events responsible for strain emergence, enhanced virulence, and epidemicity has been a long-pursued goal in infectious diseases research. A recent analysis of 3,615 genomes of serotype M1 group A Streptococcus strains (the so-called “flesh-eating” bacterium) identified a recombination event that coincides with the global M1 pandemic beginning in the early 1980s. Here, we have shown that the allelic variation that results from this recombination event, which replaces the chromosomal region encoding secreted NADase and streptolysin O, is the key driver of increased toxin production and enhanced infection severity of the M1 pandemic strains. Using isoallelic mutant strains, we found that 3 polymorphisms in this toxin gene region increase resistance to killing by human polymorphonuclear leukocytes, increase bacterial proliferation, and increase virulence in animal models of pharyngitis and necrotizing fasciitis. Genome sequencing of an additional 1,125 streptococcal strains and virulence studies revealed that a highly similar recombinational replacement event underlies an ongoing intercontinental epidemic of serotype M89 group A Streptococcus infections. By identifying the molecular changes that enhance upper respiratory tract fitness, increased resistance to innate immunity, and increased tissue destruction, we describe a mechanism that underpins epidemic streptococcal infections, which have affected many millions of people. PMID:26258415

  9. THE ANTIGENIC COMPLEX OF STREPTOCOCCUS HÆMOLYTICUS

    PubMed Central

    Lancefield, Rebecca C.

    1928-01-01

    1. The chemical and immunological characteristics of the species-specific substance (C) of Streptococcus hæmolyticus are considered. (a) It seems to be a carbohydrate because considerably purified preparations of C resisted prolonged tryptic and peptic digestion and were negative for the ordinary protein color tests but gave positive Molisch reactions to the limit of the precipitin titer. One such "purified" lot, however, had 4.2 per cent nitrogen and only 28 per cent reducing sugars on hydrolysis. Whether the nitrogen was due to impurities or was combined in the C substance itself, as is true of the Type I pneumococcus specific polysaccharide, cannot be stated without more material. (b) The C substance forms precipitates with antibacterial sera prepared against heterologous, as well as against homologous hemolytic streptococci. These precipitates are typical discs like those formed by type-specific carbohydrates of other species of bacteria. C does not precipitate antinucleoprotein sera. (c) While there is only slight direct evidence that the C substance is not antigenic, there is considerable indirect proof that this is the case. It probably is a haptene in the sense of Landsteiner. 2. A discussion is included of the chemical and immunological relationships of all the serologically active substances so far identified in extracts of the hemolytic streptococcus. PMID:19869425

  10. Disease Manifestations and Pathogenic Mechanisms of Group A Streptococcus

    PubMed Central

    Barnett, Timothy C.; McArthur, Jason D.; Cole, Jason N.; Gillen, Christine M.; Henningham, Anna; Sriprakash, K. S.; Sanderson-Smith, Martina L.; Nizet, Victor

    2014-01-01

    SUMMARY Streptococcus pyogenes, also known as group A Streptococcus (GAS), causes mild human infections such as pharyngitis and impetigo and serious infections such as necrotizing fasciitis and streptococcal toxic shock syndrome. Furthermore, repeated GAS infections may trigger autoimmune diseases, including acute poststreptococcal glomerulonephritis, acute rheumatic fever, and rheumatic heart disease. Combined, these diseases account for over half a million deaths per year globally. Genomic and molecular analyses have now characterized a large number of GAS virulence determinants, many of which exhibit overlap and redundancy in the processes of adhesion and colonization, innate immune resistance, and the capacity to facilitate tissue barrier degradation and spread within the human host. This improved understanding of the contribution of individual virulence determinants to the disease process has led to the formulation of models of GAS disease progression, which may lead to better treatment and intervention strategies. While GAS remains sensitive to all penicillins and cephalosporins, rising resistance to other antibiotics used in disease treatment is an increasing worldwide concern. Several GAS vaccine formulations that elicit protective immunity in animal models have shown promise in nonhuman primate and early-stage human trials. The development of a safe and efficacious commercial human vaccine for the prophylaxis of GAS disease remains a high priority. PMID:24696436

  11. [Streptococcus pyogenes and the brain: living with the enemy].

    PubMed

    Dale, R C

    Streptococcus pyogenes (or group A beta hemolytic streptococcus) is a pathogenic bacterium that can give rise to a range of invasive and autoimmune diseases, although it is more widely known as the cause of tonsillitis. It is particularly interesting to note that this germ only causes disease in humans. For many years it has been acknowledged that it can cause an autoimmune brain disease (Sydenham s chorea). Yet, the spectrum of post streptococcal brain disorders has recently been extended to include other movement disorders such as tics or dystonia. A number of systematic psychiatric studies have shown that certain emotional disorders generally accompany the movement disorder (particularly, obsessive compulsive disorder). The proposed pathogenetic mechanism is that of a neuronal dysfunction in which antibodies play a mediating role. The antibodies that are produced after the streptococcal infection cross react with neuronal proteins, and more especially so in individuals with a propensity. This represents a possible model of immunological mimicry and its potential importance with respect to certain idiopathic disorders such as Tourette syndrome and obsessive compulsive disorder.

  12. Induction of Cytokines by Glucosyltransferases of Streptococcus mutans

    PubMed Central

    Chia, Jean-San; Lien, Huei-Ting; Hsueh, Po-Ren; Chen, Pei-Min; Sun, Andy; Chen, Jen-Yang

    2002-01-01

    Production of proinflammatory cytokines is implicated in the pathogenesis of viridans streptococcus-induced α-streptococcal shock syndrome and infective endocarditis. Streptococcus mutans, one of the opportunistic pathogens causing infective endocarditis, was reported previously to stimulate monocytes and epithelial and endothelial cells in vitro to produce various cytokines. We found that glucosyltransferases (GTFs) GtfC and GtfD of S. mutans stimulated predominantly the production of interleukin-6 (IL-6) from T cells cultured in vitro. The level of IL-6 but not of tumor necrosis factor alpha in blood was significantly elevated when rats were injected intravenously with S. mutans GS-5, whereas IL-6 was detected at a much lower level when rats were challenged with NHS1DD, an isogenic mutant defective in the expression of GTFs. The serum IL-6 level was elevated in patients with endocarditis caused by different species of viridans streptococci which express GTF homologues. Affinity column-purified GTFs reduced the levels of detectable IL-2 of T cells stimulated by another bacterial antigen, tetanus toxoid. These results suggested that GTFs might modulate the production of Th1-type cytokines and that GTFs of S. mutans play a significant role in stimulating the production of the proinflammatory cytokine IL-6 in vivo. PMID:12093691

  13. Induction of cytokines by glucosyltransferases of streptococcus mutans.

    PubMed

    Chia, Jean-San; Lien, Huei-Ting; Hsueh, Po-Ren; Chen, Pei-Min; Sun, Andy; Chen, Jen-Yang

    2002-07-01

    Production of proinflammatory cytokines is implicated in the pathogenesis of viridans streptococcus-induced alpha-streptococcal shock syndrome and infective endocarditis. Streptococcus mutans, one of the opportunistic pathogens causing infective endocarditis, was reported previously to stimulate monocytes and epithelial and endothelial cells in vitro to produce various cytokines. We found that glucosyltransferases (GTFs) GtfC and GtfD of S. mutans stimulated predominantly the production of interleukin-6 (IL-6) from T cells cultured in vitro. The level of IL-6 but not of tumor necrosis factor alpha in blood was significantly elevated when rats were injected intravenously with S. mutans GS-5, whereas IL-6 was detected at a much lower level when rats were challenged with NHS1DD, an isogenic mutant defective in the expression of GTFs. The serum IL-6 level was elevated in patients with endocarditis caused by different species of viridans streptococci which express GTF homologues. Affinity column-purified GTFs reduced the levels of detectable IL-2 of T cells stimulated by another bacterial antigen, tetanus toxoid. These results suggested that GTFs might modulate the production of Th1-type cytokines and that GTFs of S. mutans play a significant role in stimulating the production of the proinflammatory cytokine IL-6 in vivo.

  14. Responses of innate immune cells to group A Streptococcus

    PubMed Central

    Fieber, Christina; Kovarik, Pavel

    2014-01-01

    Group A Streptococcus (GAS), also called Streptococcus pyogenes, is a Gram-positive beta-hemolytic human pathogen which causes a wide range of mostly self-limiting but also several life-threatening diseases. Innate immune responses are fundamental for defense against GAS, yet their activation by pattern recognition receptors (PRRs) and GAS-derived pathogen-associated molecular patterns (PAMPs) is incompletely understood. In recent years, the use of animal models together with the powerful tools of human molecular genetics began shedding light onto the molecular mechanisms of innate immune defense against GAS. The signaling adaptor MyD88 was found to play a key role in launching the immune response against GAS in both humans and mice, suggesting that PRRs of the Toll-like receptor (TLR) family are involved in sensing this pathogen. The specific TLRs and their ligands have yet to be identified. Following GAS recognition, induction of cytokines such as TNF and type I interferons (IFNs), leukocyte recruitment, phagocytosis, and the formation of neutrophil extracellular traps (NETs) have been recognized as key events in host defense. A comprehensive knowledge of these mechanisms is needed in order to understand their frequent failure against GAS immune evasion strategies. PMID:25325020

  15. Mechanisms of group A Streptococcus resistance to reactive oxygen species.

    PubMed

    Henningham, Anna; Döhrmann, Simon; Nizet, Victor; Cole, Jason N

    2015-07-01

    Streptococcus pyogenes, also known as group A Streptococcus (GAS), is an exclusively human Gram-positive bacterial pathogen ranked among the 'top 10' causes of infection-related deaths worldwide. GAS commonly causes benign and self-limiting epithelial infections (pharyngitis and impetigo), and less frequent severe invasive diseases (bacteremia, toxic shock syndrome and necrotizing fasciitis). Annually, GAS causes 700 million infections, including 1.8 million invasive infections with a mortality rate of 25%. In order to establish an infection, GAS must counteract the oxidative stress conditions generated by the release of reactive oxygen species (ROS) at the infection site by host immune cells such as neutrophils and monocytes. ROS are the highly reactive and toxic byproducts of oxygen metabolism, including hydrogen peroxide (H2O2), superoxide anion (O2•(-)), hydroxyl radicals (OH•) and singlet oxygen (O2*), which can damage bacterial nucleic acids, proteins and cell membranes. This review summarizes the enzymatic and regulatory mechanisms utilized by GAS to thwart ROS and survive under conditions of oxidative stress.

  16. GROUP B STREPTOCOCCUS: PREVALENCE IN A NON-OBSTETRIC POPULATION

    PubMed Central

    LECLAIR, Catherine M.; HART, Ashley E.; GOETSCH, Martha F.; CARPENTIER, Heather; JENSEN, Jeffrey T.

    2010-01-01

    Objective: To establish and compare the prevalence of Group B streptococcus (GBS) colonization in the vaginas of non-obstetric women with and without vaginitis. Materials and Methods: Cross-sectional analysis Group B streptococcus vaginal culture status of non-pregnant, estrogen-replete women ≥18 years presenting for annual gynecological exams or vaginal infection. Subjects were classified into 3 groups: no vaginitis (NV) if symptoms were absent and exam was normal, common vaginitis (CV) if microscopic exam revealed yeast, bacterial vaginosis or trichomonads, or inflammatory vaginitis (IV) if exam revealed inflammation and immature squamous cells, but no pathogens. Results: Of the 215 women recruited: 147 (68.4%) showed no evidence of vaginitis, 41 (19.1%) had CV, and 27 (12.6%) showed evidence of IV. The overall prevalence rate of GBS was 22.8%. Vaginitis was associated with a significantly increased risk of GBS colonization [Adjusted OR: CV 2.7 (1.1-6.2); IV 2.9 (1.1-8.0)]. Logistic regression revealed pH >4.5, presence of abnormal discharge on exam and a women's complaint of current symptoms to be significant predicators of the presence of GBS. Conclusion: GBS colonization occurs more commonly in women with vaginitis. This suggests that disruption of the normal vaginal bacterial environment is an important predictor for GBS colonization. PMID:20592549

  17. Phylogenomics and the dynamic genome evolution of the genus Streptococcus.

    PubMed

    Richards, Vincent P; Palmer, Sara R; Pavinski Bitar, Paulina D; Qin, Xiang; Weinstock, George M; Highlander, Sarah K; Town, Christopher D; Burne, Robert A; Stanhope, Michael J

    2014-04-01

    The genus Streptococcus comprises important pathogens that have a severe impact on human health and are responsible for substantial economic losses to agriculture. Here, we utilize 46 Streptococcus genome sequences (44 species), including eight species sequenced here, to provide the first genomic level insight into the evolutionary history and genetic basis underlying the functional diversity of all major groups of this genus. Gene gain/loss analysis revealed a dynamic pattern of genome evolution characterized by an initial period of gene gain followed by a period of loss, as the major groups within the genus diversified. This was followed by a period of genome expansion associated with the origins of the present extant species. The pattern is concordant with an emerging view that genomes evolve through a dynamic process of expansion and streamlining. A large proportion of the pan-genome has experienced lateral gene transfer (LGT) with causative factors, such as relatedness and shared environment, operating over different evolutionary scales. Multiple gene ontology terms were significantly enriched for each group, and mapping terms onto the phylogeny showed that those corresponding to genes born on branches leading to the major groups represented approximately one-fifth of those enriched. Furthermore, despite the extensive LGT, several biochemical characteristics have been retained since group formation, suggesting genomic cohesiveness through time, and that these characteristics may be fundamental to each group. For example, proteolysis: mitis group; urea metabolism: salivarius group; carbohydrate metabolism: pyogenic group; and transcription regulation: bovis group.

  18. Naturally occurring disseminated group B streptococcus infections in postnatal rats.

    PubMed

    Shuster, Katherine A; Hish, Gerald A; Selles, Lindsi A; Chowdhury, Mahboob A; Wiggins, Roger C; Dysko, Robert C; Bergin, Ingrid L

    2013-02-01

    Group B Streptococcus (Streptococcus agalactiae, GBS) is a gram-positive commensal and occasional opportunistic pathogen of the human vaginal, respiratory, and intestinal tracts that can cause sepsis, pneumonia, or meningitis in human neonates, infants, and immunosuppressed persons. We report here on a spontaneous outbreak of postnatal GBS-associated disease in rats. Ten of 26 (38.5%) 21- to 24-d-old rat pups died or were euthanized due to a moribund state in a colony of rats transgenic for the human diphtheria toxin receptor on a Munich-Wistar-Frömter genetic background. Four pups had intralesional coccoid bacteria in various organs without accompanying inflammation. GBS was isolated from the liver of 2 of these pups and from skin abscesses in 3 littermates. A connection with the transgene could not be established. A treatment protocol was evaluated in the remaining breeding female rats. GBS is a potentially clinically significant spontaneous infection in various populations of research rats, with some features that resemble late-onset postnatal GBS infection in human infants.

  19. Molecular Epidemiology of sil Locus in Clinical Streptococcus pyogenes Strains

    PubMed Central

    Plainvert, Céline; Dinis, Márcia; Ravins, Miriam; Hanski, Emanuel; Touak, Gérald; Dmytruk, Nicolas; Fouet, Agnès

    2014-01-01

    Streptococcus pyogenes (group A Streptococcus [GAS]) causes a wide variety of diseases, ranging from mild noninvasive to severe invasive infections. Mutations in regulatory components have been implicated in the switch from colonization to invasive phenotypes. The inactivation of the sil locus, composed of six genes encoding a quorum-sensing complex, gives rise to a highly invasive strain. However, studies conducted on limited collections of GAS strains suggested that sil prevalence is around 15%; furthermore, whereas a correlation between the presence of sil and the genetic background was suggested, no link between the presence of a functional sil locus and the invasive status was assessed. We established a collection of 637 nonredundant strains covering all emm genotypes present in France and of known clinical history; 68%, 22%, and 10% were from invasive infections, noninvasive infections, and asymptomatic carriage, respectively. Among the 637 strains, 206 were sil positive. The prevalence of the sil locus varied according to the emm genotype, being present in >85% of the emm4, emm18, emm32, emm60, emm87, and emm90 strains and absent from all emm1, emm28, and emm89 strains. A random selection based on 2009 French epidemiological data indicated that 16% of GAS strains are sil positive. Moreover, due to mutations leading to truncated proteins, only 9% of GAS strains harbor a predicted functional sil system. No correlation was observed between the presence or absence of a functional sil locus and the strain invasiveness status. PMID:24671796

  20. The cell-bound α-amylases of Streptococcus bovis

    PubMed Central

    Walker, Gwen J.

    1965-01-01

    1. The cell-bound α-amylase of Streptococcus bovis has been isolated from other carbohydrases in the cell extract by chromatography on DEAE-cellulose. The enzyme has been compared with the extracellular α-amylase produced by this organism. 2. The two amylases had similar action patterns on amylose, the main product being maltotriose with smaller amounts of maltose and a little glucose. 3. The cell-bound amylase hydrolysed maltopentaose and maltohexaose at a similar rate to the hydrolysis of amylose. Maltotetraose was hydrolysed six times more slowly, and maltotriose 280 times more slowly, than amylose. 4. Studies with end-labelled maltodextrins revealed that the cell-bound α-amylase preferentially hydrolysed the third linkage from the non-reducing end, liberating maltotriose. The linkage at the reducing end of maltotriose was more easily hydrolysed than the other. 5. Egg-white lysozyme and the extracellular enzymes of Streptomyces albus lysed the cell walls of Streptococcus bovis, releasing amylase into the medium. In the presence of 0·6 m-sucrose 10% of the maximal amylase activity was released by lysozyme. Suspension of the spheroplasts in dilute buffer caused the rupture of the cytoplasmic membrane and the liberation of amylase. 6. A sensitive method for determining the ability of amylases to degrade starch granules is described. PMID:14346085

  1. Mechanisms of group A Streptococcus resistance to reactive oxygen species

    PubMed Central

    Henningham, Anna; Döhrmann, Simon; Nizet, Victor; Cole, Jason N.

    2015-01-01

    Streptococcus pyogenes, also known as group A Streptococcus (GAS), is an exclusively human Gram-positive bacterial pathogen ranked among the ‘top 10’ causes of infection-related deaths worldwide. GAS commonly causes benign and self-limiting epithelial infections (pharyngitis and impetigo), and less frequent severe invasive diseases (bacteremia, toxic shock syndrome and necrotizing fasciitis). Annually, GAS causes 700 million infections, including 1.8 million invasive infections with a mortality rate of 25%. In order to establish an infection, GAS must counteract the oxidative stress conditions generated by the release of reactive oxygen species (ROS) at the infection site by host immune cells such as neutrophils and monocytes. ROS are the highly reactive and toxic byproducts of oxygen metabolism, including hydrogen peroxide (H2O2), superoxide anion (O2•−), hydroxyl radicals (OH•) and singlet oxygen (O2*), which can damage bacterial nucleic acids, proteins and cell membranes. This review summarizes the enzymatic and regulatory mechanisms utilized by GAS to thwart ROS and survive under conditions of oxidative stress. PMID:25670736

  2. Proteomic Biomarkers Associated with Streptococcus agalactiae Invasive Genogroups

    PubMed Central

    Lanotte, Philippe; Perivier, Marylise; Haguenoer, Eve; Mereghetti, Laurent; Burucoa, Christophe; Claverol, Stéphane; Atanassov, Christo

    2013-01-01

    Group B streptococcus (GBS, Streptococcus agalactiae) is a leading cause of meningitis and sepsis in newborns and an etiological agent of meningitis, endocarditis, osteoarticular and soft tissue infections in adults. GBS isolates are routinely clustered in serotypes and in genotypes. At present one GBS sequence type (i.e. ST17) is considered to be closely associated with bacterial invasiveness and novel proteomic biomarkers could make a valuable contribution to currently available GBS typing data. For that purpose we analyzed the protein profiles of 170 genotyped GBS isolates by Surface-Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (SELDI). Univariate statistical analysis of the SELDI profiles identified four protein biomarkers significantly discriminating ST17 isolates from those of the other sequence types. Two of these biomarkers (MW of 7878 Da and 12200 Da) were overexpressed and the other two (MW of 6258 Da and 10463 Da) were underexpressed in ST17. The four proteins were isolated by mass spectrometry-assisted purification and their tryptic peptides analyzed by LC-MS/MS. They were thereby identified as the small subunit of exodeoxyribonuclease VII, the 50S ribosomal protein L7/L12, a CsbD-like protein and thioredoxin, respectively. In conclusion, we identified four candidate biomarkers of ST17 by SELDI for high-throughput screening. These markers may serve as a basis for further studies on the pathophysiology of GBS infection, and for the development of novel vaccines. PMID:23372719

  3. Human milk oligosaccharides inhibit growth of group B Streptococcus.

    PubMed

    Lin, Ann E; Autran, Chloe A; Szyszka, Alexandra; Escajadillo, Tamara; Huang, Mia; Godula, Kamil; Prudden, Anthony R; Boons, Geert-Jan; Lewis, Amanda L; Doran, Kelly S; Nizet, Victor; Bode, Lars

    2017-07-07

    Streptococcus agalactiae (group B Streptococcus, GBS) is a leading cause of invasive bacterial infections in newborns, typically acquired vertically during childbirth secondary to maternal vaginal colonization. Human milk oligosaccharides (HMOs) have important nutritional and biological activities that guide the development of the immune system of the infant and shape the composition of normal gut microbiota. In this manner, HMOs help protect against pathogen colonization and reduce the risk of infection. In the course of our studies of HMO-microbial interactions, we unexpectedly uncovered a novel HMO property to directly inhibit the growth of GBS independent of host immunity. By separating different HMO fractions through multidimensional chromatography, we found the bacteriostatic activity to be confined to specific non-sialylated HMOs and synergistic with a number of conventional antibiotic agents. Phenotypic screening of a GBS transposon insertion library identified a mutation within a GBS-specific gene encoding a putative glycosyltransferase that confers resistance to HMOs, suggesting that HMOs may function as an alternative substrate to modify a GBS component in a manner that impairs growth kinetics. Our study uncovers a unique antibacterial role for HMOs against a leading neonatal pathogen and expands the potential therapeutic utility of these versatile molecules. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Identification of Major Outer Surface Proteins of Streptococcus agalactiae

    PubMed Central

    Hughes, Martin J. G.; Moore, Joanne C.; Lane, Jonathan D.; Wilson, Rebecca; Pribul, Philippa K.; Younes, Zabin N.; Dobson, Richard J.; Everest, Paul; Reason, Andrew J.; Redfern, Joanne M.; Greer, Fiona M.; Paxton, Thanai; Panico, Maria; Morris, Howard R.; Feldman, Robert G.; Santangelo, Joseph D.

    2002-01-01

    To identify the major outer surface proteins of Streptococcus agalactiae (group B streptococcus), a proteomic analysis was undertaken. An extract of the outer surface proteins was separated by two-dimensional electrophoresis. The visualized spots were identified through a combination of peptide sequencing and reverse genetic methodologies. Of the 30 major spots identified as S. agalactiae specific, 27 have been identified. Six of these proteins, previously unidentified in S. agalactiae, were sequenced and cloned. These were ornithine carbamoyltransferase, phosphoglycerate kinase, nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase, purine nucleoside phosphorylase, enolase, and glucose-6-phosphate isomerase. Using a gram-positive expression system, we have overexpressed two of these proteins in an in vitro system. These recombinant, purified proteins were used to raise antisera. The identification of these proteins as residing on the outer surface was confirmed by the ability of the antisera to react against whole, live bacteria. Further, in a neonatal-animal model system, we demonstrate that some of these sera are protective against lethal doses of bacteria. These studies demonstrate the successful application of proteomics as a technique for identifying vaccine candidates. PMID:11854208

  5. METABOLISM OF RESISTANT MUTANTS OF STREPTOCOCCUS FAECALIS IV.

    PubMed Central

    Coultas, M. Katharine; Hutchison, Dorris J.

    1962-01-01

    Coultas, M. Katharine (Sloan-Kettering Institute for Cancer Research, Rye, N.Y.) and Dorris J. Hutchison. Metabolism of resistant mutants of Streptococcus faecalis. IV. Use of a biophotometer in growth-curve studies. J. Bacteriol. 84:393–401. 1962. — Analysis of data obtained using the Bonet-Maury and Jouan biophotometer has shown it to be an accurate, automatic device for recording an entire bacterial growth curve, from which quantitative measurements of growth rate can be calculated. Growth rate values obtained in this manner agree with those obtained by conventional methods. The instrument is described in detail and reference is given to other uses of this type of photometer. The growth curves of Streptococcus faecalis ATCC 8043 and three mutants resistant to purine analogues were compared in media with and without a purine. Differences in these growth curves were evident. In the purine-deficient medium SF/AZAG, the 8-azaguanine-resistant mutant had the shortest doubling time, 61 min, followed by the two 6-mercaptopurine-resistant mutants (SF/MPcc, 72 min; SF/MP, 91 min), and finally the wild strain with a doubling time of 135 min. In the medium supplemented with xanthine, the respective doubling times were 52, 61, 68, and 68 min. Images PMID:14023399

  6. Characterisation of Streptococcus suis isolates from wild boars (Sus scrofa).

    PubMed

    Sánchez del Rey, Verónica; Fernández-Garayzábal, José F; Mentaberre, Gregorio; Briones, Víctor; Lavín, Santiago; Domínguez, Lucas; Gottschalk, Marcelo; Vela, Ana Isabel

    2014-06-01

    Wild boar are widely distributed throughout the Iberian Peninsula and can carry potentially virulent strains of Streptococcus suis. The objective of this study was to determine the prevalence of S. suis in wild boars from two large geographical regions of Spain. Serotypes 1, 2, 7 and 9 identified were further genetically characterised by virulence-associated genotyping, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) to determine the population structure of S. suis carried by these animals. Streptococcus suis was isolated from 39.1% of the wild boars examined: serotype 9 was the most frequently isolated (12.5%), followed by serotype 1 (2.5%). Serotype 2 was rarely isolated (0.3%). Eighteen additional serotypes were identified indicating wide diversity of this pathogen within the wild boar population. This heterogeneity was confirmed by PFGE and MLST analyses and the majority of isolates exhibited the virulence-associated genotype mrp-/epf-/sly-. The results of this study highlight that the carriage of S. suis by wild boars is commonplace. However, MLST data indicate that these isolates are not related to prevalent clonal complexes ST1, ST16, ST61 and ST87 typically associated with infection of pigs or humans in Europe. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Oxygen dependent pyruvate oxidase expression and production in Streptococcus sanguinis

    PubMed Central

    Zheng, Lan-yan; Itzek, Andreas; Chen, Zhi-yun; Kreth, Jens

    2011-01-01

    The objective of this study was to characterize the oxygen dependent regulation of pyruvate oxidase (SpxB) gene expression and protein production in Streptococcus sanguinis (S. sanguinis). SpxB is responsible for the generation of growth-inhibiting amounts of hydrogen peroxide (H2O2) able to antagonize cariogenic Streptococcus mutans (S. mutans). Furthermore, the ecological consequence of H2O2 production was investigated in its self-inhibiting ability towards the producing strain. Expression of spxB was determined with quantitative Real-Time RT-PCR and a fluorescent expression reporter strain. Protein abundance was investigated with FLAG epitope engineered in frame on the C-terminal end of SpxB. Self inhibition was tested with an antagonism plate assay. The expression and protein abundance decreased in cells grown under anaerobic conditions. S. sanguinis was resistant against its own produced H2O2, while cariogenic S. mutans was inhibited in its growth. The results suggest that S. sanguinis produces H2O2 as antimicrobial substance to inhibit susceptible niche competing species like S. mutans during initial biofilm formation, when oxygen availability allows for spxB expression and Spx production. PMID:21485312

  8. Responses of innate immune cells to group A Streptococcus.

    PubMed

    Fieber, Christina; Kovarik, Pavel

    2014-01-01

    Group A Streptococcus (GAS), also called Streptococcus pyogenes, is a Gram-positive beta-hemolytic human pathogen which causes a wide range of mostly self-limiting but also several life-threatening diseases. Innate immune responses are fundamental for defense against GAS, yet their activation by pattern recognition receptors (PRRs) and GAS-derived pathogen-associated molecular patterns (PAMPs) is incompletely understood. In recent years, the use of animal models together with the powerful tools of human molecular genetics began shedding light onto the molecular mechanisms of innate immune defense against GAS. The signaling adaptor MyD88 was found to play a key role in launching the immune response against GAS in both humans and mice, suggesting that PRRs of the Toll-like receptor (TLR) family are involved in sensing this pathogen. The specific TLRs and their ligands have yet to be identified. Following GAS recognition, induction of cytokines such as TNF and type I interferons (IFNs), leukocyte recruitment, phagocytosis, and the formation of neutrophil extracellular traps (NETs) have been recognized as key events in host defense. A comprehensive knowledge of these mechanisms is needed in order to understand their frequent failure against GAS immune evasion strategies.

  9. Streptococcus caprae sp. nov., isolated from Iberian ibex (Capra pyrenaica hispanica).

    PubMed

    Vela, A I; Mentaberre, G; Lavín, S; Domínguez, L; Fernández-Garayzábal, J F

    2016-01-01

    Biochemical and molecular genetic studies were performed on a novel Gram-stain-positive, catalase-negative, coccus-shaped organism isolated from tonsil samples of two Iberian ibexes. The micro-organism was identified as a streptococcal species based on its cellular, morphological and biochemical characteristics. 16S rRNA gene sequence comparison studies confirmed its identification as a member of the genus Streptococcus, but the organism did not correspond to any species of this genus. The nearest phylogenetic relative of the unknown coccus from ibex was Streptococcus porci 2923-03T (96.6 % 16S rRNA gene sequence similarity). Analysis based on rpoB and sodA gene sequences revealed sequence similarity values lower than 86.0 and 83.8 %, respectively, from the type strains of recognized Streptococcus species. The novel bacterial isolate was distinguished from Streptococcus porci and other Streptococcus species using biochemical tests. Based on both phenotypic and phylogenetic findings, it is proposed that the unknown bacterium be classified as representing a novel species of the genus Streptococcus, for which the name Streptococcus caprae sp. nov. is proposed. The type strain is DICM07-02790-1CT ( = CECT 8872T = CCUG 67170T).

  10. Streptococcus oriloxodontae sp. nov., isolated from the oral cavities of elephants.

    PubMed

    Shinozaki-Kuwahara, Noriko; Saito, Masanori; Hirasawa, Masatomo; Takada, Kazuko

    2014-11-01

    Two strains were isolated from oral cavity samples of healthy elephants. The isolates were Gram-positive, catalase-negative, coccus-shaped organisms that were tentatively identified as a streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequence analysis suggested classification of these organisms in the genus Streptococcus with Streptococcus criceti ATCC 19642(T) and Streptococcus orisuis NUM 1001(T) as their closest phylogenetic neighbours with 98.2 and 96.9% gene sequence similarity, respectively. When multi-locus sequence analysis using four housekeeping genes, groEL, rpoB, gyrB and sodA, was carried out, similarity of concatenated sequences of the four housekeeping genes from the new isolates and Streptococcus mutans was 89.7%. DNA-DNA hybridization experiments suggested that the new isolates were distinct from S. criceti and other species of the genus Streptococcus. On the basis of genotypic and phenotypic differences, it is proposed that the novel isolates are classified in the genus Streptococcus as representatives of Streptococcus oriloxodontae sp. nov. The type strain of S. oriloxodontae is NUM 2101(T) ( =JCM 19285(T) =DSM 27377(T)).

  11. Streptococcus danieliae sp. nov., a novel bacterium isolated from the caecum of a mouse.

    PubMed

    Clavel, Thomas; Charrier, Cédric; Haller, Dirk

    2013-01-01

    We report the characterization of one novel bacterium, strain ERD01G(T), isolated from the cecum of a TNF(deltaARE) mouse. The strain was found to belong to the genus Streptococcus based on phylogenetic analysis of partial 16S rRNA gene sequences. The bacterial species with standing name in nomenclature that was most closely related to our isolate was Streptococcus alactolyticus (97 %). The two bacteria were characterized by a DNA-DNA hybridization similarity value of 35 %, demonstrating that they belong to different species. The new isolate was negative for acetoin production, esculin hydrolysis, urease, α-galactosidase and β-glucosidase, was able to produce acid from starch and trehalose, grew as beta-hemolytic coccobacilli on blood agar, did not grow at >40 °C, did not survive heat treatment at 60 °C for 20 min and showed negative agglutination in Lancefield tests. On the basis of these characteristics, strain ERD01G(T) differed from the most closely related species S. alactolyticus, Streptococcus gordonii, Streptococcus intermedius and Streptococcus sanguinis. Thus, based on genotypic and phenotypic evidence, we propose that the isolate belongs to a novel bacterial taxon within the genus Streptococcus, for which the name Streptococcus danieliae is proposed. The type strain is ERD01G(T) (= DSM 22233(T) = CCUG 57647(T)).

  12. Streptococcus mutans and Streptococcus sobrinus detection by Polymerase Chain Reaction and their relation to dental caries in 12 and 15 year-old schoolchildren in Valencia (Spain)

    PubMed Central

    Sánchez-Acedo, Mateo; Montiel-Company, José M.; Dasí-Fernández, Francisco

    2013-01-01

    A cross-sectional study was carried out to determine the prevalence of Streptococcus mutans and Streptococcus sobrinus and the association of the two in a random sample (n=614) of the child population of the region of Valencia (Spain). Saliva samples were analyzed by the quantitative polymerase chain reaction (PCR) method to study the relation of these bacteria to caries prevalence and the DMFT index. The prevalence of S. mutans was 35.4% at age 12 and 22.9% at age 15, that of S. sobrinus 18.9% and 8.4% and that of the S. mutans-S. sobrinus association 18.2% and 6.8% respectively. At both 12 and 15 years of age, the caries prevalence rates were lower in the Streptococcus-free group of children (37.6% and 48.5% respectively) and higher in the S.mutans-only group (67.3% and 74.0%). At the age of 12, the DMFT index was significantly higher in the mutans-only carriers (2.1) than in the Streptococcus-free and S. mutans-S. sobrinus association groups (both 0.9). At the age of 15, the DMFT index was significantly higher in the S. mutans-S. sobrinus association (3.71) and mutans-only (3.1) carrier groups than in the Streptococcus-free group (1.4). Determination of S. mutans and S. sobrinus by real-time quantitative PCR can provide valuable information for caries risk assessment in epidemiological studies. Key words:Streptococcus mutans, Streptococcus sobrinus, polymerase chain reaction, dental caries, cross-sectional studies. PMID:23722138

  13. Versatility of choline metabolism and choline-binding proteins in Streptococcus pneumoniae and commensal streptococci.

    PubMed

    Hakenbeck, Regine; Madhour, Abderrahim; Denapaite, Dalia; Brückner, Reinhold

    2009-05-01

    The pneumococcal choline-containing teichoic acids are targeted by cholinebinding proteins (CBPs), major surface components implicated in the interaction with host cells and bacterial cell physiology. CBPs also occur in closely related commensal species, Streptococcus oralis and Streptococcus mitis, and many strains of these species contain choline in their cell wall. Physiologically relevant CBPs including cell wall lytic enzymes are highly conserved between Streptococcus pneumoniae and S. mitis. In contrast, the virulence-associated CBPs, CbpA, PspA and PcpA, are S. pneumoniae specific and are thus relevant for the characteristic properties of this species.

  14. STUDIES ON THE RELATIONSHIP OF STREPTOCOCCUS HEMOLYTICUS TO THE RHEUMATIC PROCESS

    PubMed Central

    Coburn, Alvin F.; Pauli, Ruth H.

    1932-01-01

    In the first two papers findings were presented which point to a close relationship between the incidence of rheumatic fever and the distribution of Streptococcus hemolyticus. The fact was emphasized that in the rheumatic subject a recrudescence of the disease process is usually preceded by pharyngeal infection with hemolytic streptococci. These organisms conspicuous in the throat flora during the period of infection preliminary to an attack of acute rheumatism fell into six antigenic groups and produced toxins which in 70 per cent were neutralized by a monovalent streptococcus antiserum. In the present study, four series of observations have been presented, demonstrating the development of immune bodies to hemolytic streptococcus during the course of rheumatic fever. The agglutination and complement fixation reactions of sera from patients with acute rheumatism suggest recent infection with streptococcus. Precipitin tests indicate that at the time of appearance of the rheumatic attack, individuals develop, in their blood, precipitins to the protein fractions of hemolytic streptococcus. That these precipitins may not be entirely specific is recognized from their cross-reactions with antigens of chemically related organisms. The studies made in association with E. W. Todd of England have demonstrated that at the onset of an attack of acute rheumatism, there occurs in each instance a rise in the antistreptolysin titer of the patient's serum. This titer is much higher than that observed in normal subjects or in patients with bacterial infection other than hemolytic streptococcus. This presence of antistreptolysin with an N.D. of 0.005 cc. is considered strong evidence of recent infection by hemolytic streptococcus. In conclusion, the relationship between the incidence of hemolytic streptococcus and the geographical distribution of rheumatic fever, the relationship between the recrudescence in the rheumatic subject and infection of the throat with hemolytic

  15. Beta-hemolytic Streptococcus dysgalactiae strains isolated from horses are a genetically distinct population within the Streptococcus dysgalactiae taxon

    PubMed Central

    Pinho, Marcos D.; Erol, Erdal; Ribeiro-Gonçalves, Bruno; Mendes, Catarina I.; Carriço, João A.; Matos, Sandra C.; Preziuso, Silvia; Luebke-Becker, Antina; Wieler, Lothar H.; Melo-Cristino, Jose; Ramirez, Mario

    2016-01-01

    The pathogenic role of beta-hemolytic Streptococcus dysgalactiae in the equine host is increasingly recognized. A collection of 108 Lancefield group C (n = 96) or L (n = 12) horse isolates recovered in the United States and in three European countries presented multilocus sequence typing (MLST) alleles, sequence types and emm types (only 56% of the isolates could be emm typed) that were, with few exceptions, distinct from those previously found in human Streptococcus dysgalactiae subsp. equisimilis. Characterization of a subset of horse isolates by multilocus sequence analysis (MLSA) and 16S rRNA gene sequence showed that most equine isolates could also be differentiated from S. dysgalactiae strains from other animal species, supporting the existence of a horse specific genomovar. Draft genome information confirms the distinctiveness of the horse genomovar and indicates the presence of potentially horse-specific virulence factors. While this genomovar represents most of the isolates recovered from horses, a smaller MLST and MLSA defined sub-population seems to be able to cause infections in horses, other animals and humans, indicating that transmission between hosts of strains belonging to this group may occur. PMID:27530432

  16. mef(A) is the predominant macrolide resistance determinant in Streptococcus pneumoniae and Streptococcus pyogenes in Germany.

    PubMed

    Bley, Christine; van der Linden, Mark; Reinert, Ralf René

    2011-05-01

    In this study, macrolide-resistant Streptococcus pneumoniae and Streptococcus pyogenes isolates from Germany were carefully characterised by susceptibility testing, phenotyping, polymerase chain reaction (PCR) and sequencing of macrolides resistance genes, and multilocus sequence typing (MLST). Of 2045 S. pneumoniae and 352 S. pyogenes isolates, 437 (21.4%) and 29 (8.2%), respectively, were found to be macrolide-resistant. Amongst the S. pneumoniae isolates, the most prevalent resistance marker was mef(A) (57.7%) followed by erm(B) (27.0%) and mef(E) (11.2%). Of note, the dual resistance mechanism mef(E)+erm(B) was found in a relatively high proportion (4.1%) of pneumococcal isolates. Amongst the S. pyogenes isolates, 31.0% carried mef(A), 34.5% erm(B) and 13.8% erm(A). Dissemination of a single clone [mef(A)-positive England(14)-9] has significantly contributed to the emergence of macrolide resistance amongst pneumococci in Germany.

  17. Beta-hemolytic Streptococcus dysgalactiae strains isolated from horses are a genetically distinct population within the Streptococcus dysgalactiae taxon.

    PubMed

    Pinho, Marcos D; Erol, Erdal; Ribeiro-Gonçalves, Bruno; Mendes, Catarina I; Carriço, João A; Matos, Sandra C; Preziuso, Silvia; Luebke-Becker, Antina; Wieler, Lothar H; Melo-Cristino, Jose; Ramirez, Mario

    2016-08-17

    The pathogenic role of beta-hemolytic Streptococcus dysgalactiae in the equine host is increasingly recognized. A collection of 108 Lancefield group C (n = 96) or L (n = 12) horse isolates recovered in the United States and in three European countries presented multilocus sequence typing (MLST) alleles, sequence types and emm types (only 56% of the isolates could be emm typed) that were, with few exceptions, distinct from those previously found in human Streptococcus dysgalactiae subsp. equisimilis. Characterization of a subset of horse isolates by multilocus sequence analysis (MLSA) and 16S rRNA gene sequence showed that most equine isolates could also be differentiated from S. dysgalactiae strains from other animal species, supporting the existence of a horse specific genomovar. Draft genome information confirms the distinctiveness of the horse genomovar and indicates the presence of potentially horse-specific virulence factors. While this genomovar represents most of the isolates recovered from horses, a smaller MLST and MLSA defined sub-population seems to be able to cause infections in horses, other animals and humans, indicating that transmission between hosts of strains belonging to this group may occur.

  18. Effect of cigarette smoke exposure on the growth of Streptococcus mutans and Streptococcus sanguis: an in vitro study.

    PubMed

    Zonuz, Ali Taghavi; Rahmati, Ali; Mortazavi, Hadi; Khashabi, Ehasn; Farahani, Ramin Mostofi Zadeh

    2008-01-01

    The aim of the present study was to determine the effect of cigarette smoke on the growth of Streptococcus mutans and Streptococcus sanguis. The standard strains of S. mutans (ATCC 25175) and S. sanguis (ATCC 10556) were cultured on blood agar and incubated for 48 hr in three main environments: atmospheric air, carbon dioxide, and cigarette smoke. Kent gold 1(nicotine: 0.1 mg, tar: 1 mg), Kent lights (nicotine: 0.8 mg, tar: 9 mg) and Bahman (nicotine: 1 mg, tar: 13 mg) were the brands used in the present study. Afterwards, digital photographs of the colonies were taken and the diameter of colonies was measured. Data were analyzed using Post Hoc and General Linear Model statistical tests. Cigarette smoke and carbon dioxide environments significantly increased the growth of S. mutans. However, high nicotine/tar content cigarette smoke (Bahman) had the greatest impact on S. mutans and S. sanguis. The mutans/sanguis ratio, which was 0.71 in atmospheric air, increased to 1.07 in the presence of carbon dioxide. Kent gold 1, Kent lights, and Bahman demonstrated a mutans/sanguis ratio of 1, 0.84, and 0.98 respectively. In conclusion, it seems that the growth of S. sanguis and S. mutans is accelerated in the vicinity of cigarette smoke.

  19. A novel suicide shuttle plasmid for Streptococcus suis serotype 2 and Streptococcus equi ssp. zooepidemicus gene mutation

    PubMed Central

    Liu, Rui; Zhang, Ping; Su, Yiqi; Lin, Huixing; Zhang, Hui; Yu, Lei; Ma, Zhe; Fan, Hongjie

    2016-01-01

    The mariner-based Himar1 system has been utilized for creating mutant libraries of many Gram-positive bacteria. Streptococcus suis serotype 2 (SS2) and Streptococcus equi ssp. zooepidemicus (SEZ) are primary pathogens of swine that threaten the swine industry in China. To provide a forward-genetics technology for finding virulent phenotype-related genes in these two pathogens, we constructed a novel temperature-sensitive suicide shuttle plasmid, pMar4s, which contains the Himar1 system transposon, TnYLB-1, and the Himar1 C9 transposase from pMarA and the repTAs temperature-sensitive fragment from pSET4s. The kanamycin (Kan) resistance gene was in the TnYLB-1 transposon. Temperature sensitivity and Kan resistance allowed the selection of mutant strains and construction of the mutant library. The SS2 and SEZ mutant libraries were successfully constructed using the pMar4s plasmid. Inverse-Polymerase Chain Reaction (Inverse-PCR) results revealed large variability in transposon insertion sites and that the library could be used for phenotype alteration screening. The thiamine biosynthesis gene apbE was screened for its influence on SS2 anti-phagocytosis; likewise, the sagF gene was identified to be a hemolytic activity-related gene in SEZ. pMar4s was suitable for mutant library construction, providing more information regarding SS2 and SEZ virulence factors and illustrating the pathogenesis of swine streptococcosis. PMID:27256117

  20. Solitary Pyomyositis of the Left Rhomboideus Muscle Caused by Streptococcus anginosus and Streptococcus intermedius in an Immunocompetent Person.

    PubMed

    Tanaka, Yasuhiro; Takaya, Kenichi; Yamamoto, Go; Shinzato, Isaku; Takafuta, Toshiro

    2015-01-01

    Primary pyomyositis is a bacterial infection of the skeletal muscle commonly affecting children with Staphylococcus aureus most often isolated as a pathogen. However, pyomyositis caused by anaerobic bacteria is rare in adults. Here, we report a case of solitary Pyomyositis of the left rhomboideus muscle in an immunocompetent person. A 70-year-old Japanese male presented with high fever and left shoulder pain. His muscle below the lower edge of the left scapula was tender and swollen. His laboratory examinations revealed severe inflammation. Computed tomography showed a solitary low-density area around a contrast enhancement in the left rhomboideus muscle. He was diagnosed as having solitary pyomyositis. Although his symptoms did not improve despite empiric intravenous administration of antibiotics, an incision was performed. Streptococcus anginosus and Streptococcus intermedius were isolated from the culture of drainage fluid. His symptoms gradually disappeared after the incisional drainage and continuous administration of antibiotics. Pyomyositis did not recur after his discharge. To the best of our knowledge, this is the first report on anaerobic pyomyositis of the shoulder muscle.

  1. Streptococcus mutans and Streptococcus sobrinus colonization and caries experience in 3- and 5-year-old Thai children

    PubMed Central

    Saraithong, P.; Pattanaporn, K.; Chen, Z.; Khongkhunthian, S.; Laohapensang, P.; Chhun, N.; Pattanaporn, W.; Gaw, H. Y.; Li, Y.

    2016-01-01

    Objectives The aim of this study was to examine the colonization of Streptococcus mutans and Streptococcus sobrinus in supra-gingival plaque samples and to determine their correlation with the prevalence of early childhood caries (ECC) in Thai children. Materials and methods A total of 344 Thai children, ages 3 and 5 years, were invited to participate in this study. Caries status of the children was examined. Supra-gingival plaque samples were collected. Quantitative real-time PCR was performed to evaluate DNA levels of S. mutans and S. sobrinus. Results Eighty-five percent of the children were colonized by S. mutans and 50.9 % of them were colonized by S. sobrinus. The prevalence of ECC was 43.8 % and 56.2 % among 3- and 5-year-old children, respectively, and was significantly associated with the presence of S. mutans and S. sobrinus. The severity of ECC was significantly correlated with increased DNA levels of the two bacteria. Children who were positive for S. mutans and S. sobrinus (Sm+/Sb+) were 8 times or 44 times more likely to experience ECC than children who were Sm−/Sb+or were Sm−/Sb−. Conclusions The study evidence further suggest that children colonized by both S. mutans and S. sobrinus are at the higher risk for ECC. Clinical relevance Molecular-based qPCR can be used to detect and quantify S. mutans and S. sobrinus colonization for epidemiological and clinical studies for ECC risk assessment. PMID:25753978

  2. Identification of a high-virulence clone of type III Streptococcus agalactiae (group B Streptococcus) causing invasive neonatal disease.

    PubMed Central

    Musser, J M; Mattingly, S J; Quentin, R; Goudeau, A; Selander, R K

    1989-01-01

    Chromosomal genotypes of 128 isolates of six serotypes (Ia, Ib, Ic, II, Ic/II, and III) of Streptococcus agalactiae (group B Streptococcus) recovered predominantly from human infants in the United States were characterized by an analysis of electrophoretically demonstrable allelic profiles at 11 metabolic enzyme loci. Nineteen distinctive electrophoretic types (ETs), representing multilocus clonal genotypes, were identified. Mean genetic diversity per locus among ETs of isolates of the same serotype was, on average, nearly equal to that in all 19 ETs. Cluster analysis of the ETs revealed two primary phylogenetic divisions at a genetic distance of 0.65. A single clone (ET 1) represented by 40 isolates expressing type III antigen formed division I. Division II was composed of 18 ETs in three major lineages diverging from one another at distances greater than 0.35 and included strains of all six antigenic classes. The type III organisms in division I produce more extracellular neuraminidase and apparently are more virulent than the type III strains in division II, which are related to strains of other serotypes that cause disease much less frequently. The existence of this unusually virulent clone accounts, in major part, for the high morbidity and mortality associated with infection by type III organisms. PMID:2660146

  3. Salivaricin G32, a Homolog of the Prototype Streptococcus pyogenes Nisin-Like Lantibiotic SA-FF22, Produced by the Commensal Species Streptococcus salivarius.

    PubMed

    Wescombe, Philip A; Dyet, Kristin H; Dierksen, Karen P; Power, Daniel A; Jack, Ralph W; Burton, Jeremy P; Inglis, Megan A; Wescombe, Anna L; Tagg, John R

    2012-01-01

    Salivaricin G32, a 2667 Da novel member of the SA-FF22 cluster of lantibiotics, has been purified and characterized from Streptococcus salivarius strain G32. The inhibitory peptide differs from the Streptococcus pyogenes-produced SA-FF22 in the absence of lysine in position 2. The salivaricin G32 locus was widely distributed in BLIS-producing S. salivarius, with 6 (23%) of 26 strains PCR-positive for the structural gene, slnA. As for most other lantibiotics produced by S. salivarius, the salivaricin G32 locus can be megaplasmid encoded. Another member of the SA-FF22 family was detected in two Streptococcus dysgalactiae of bovine origin, an observation supportive of widespread distribution of this lantibiotic within the genus Streptococcus. Since the inhibitory spectrum of salivaricin G32 includes Streptococcus pyogenes, its production by S. salivarius, either as a member of the normal oral microflora or as a commercial probiotic, could serve to enhance protection of the human host against S. pyogenes infection.

  4. Salivaricin G32, a Homolog of the Prototype Streptococcus pyogenes Nisin-Like Lantibiotic SA-FF22, Produced by the Commensal Species Streptococcus salivarius

    PubMed Central

    Wescombe, Philip A.; Dyet, Kristin H.; Dierksen, Karen P.; Power, Daniel A.; Jack, Ralph W.; Burton, Jeremy P.; Inglis, Megan A.; Wescombe, Anna L.; Tagg, John R.

    2012-01-01

    Salivaricin G32, a 2667 Da novel member of the SA-FF22 cluster of lantibiotics, has been purified and characterized from Streptococcus salivarius strain G32. The inhibitory peptide differs from the Streptococcus pyogenes—produced SA-FF22 in the absence of lysine in position 2. The salivaricin G32 locus was widely distributed in BLIS-producing S. salivarius, with 6 (23%) of 26 strains PCR-positive for the structural gene, slnA. As for most other lantibiotics produced by S. salivarius, the salivaricin G32 locus can be megaplasmid encoded. Another member of the SA-FF22 family was detected in two Streptococcus dysgalactiae of bovine origin, an observation supportive of widespread distribution of this lantibiotic within the genus Streptococcus. Since the inhibitory spectrum of salivaricin G32 includes Streptococcus pyogenes, its production by S. salivarius, either as a member of the normal oral microflora or as a commercial probiotic, could serve to enhance protection of the human host against S. pyogenes infection. PMID:22567013

  5. The antibacterial effect of four mouthwashes against streptococcus mutans and escherichia coli.

    PubMed

    Ghapanchi, Janan; Lavaee, Fatemeh; Moattari, Afagh; Shakib, Mahmood

    2015-04-01

    To evaluate the antimicrobial properties of several mouthwash concentrations on oral Streptococcus mutans and Escherichia coli. The study was conducted at Shiraz Medicine School in 2011. Serial dilutions of Chlorohexidin, Oral B and Persica and Irsha (2,4,8,16,64,128) were prepared in Muller-Hinton media. Minimum inhibitory concentration was visually determined and defined as the lowest concentration of each oral washing which inhibited > 95% growth reduction compared to the growth control well. Chlorhexidine, Oral B and Irsha mouthwash inhibited Streptococcus mutans even with diluted concentrations. Also, Chlorhexidine and Oral B prohibited Escherichia coli with different potencies. But Persica had no antimicrobial activity against either Escherichia coli or Streptococcus mutans. Chlorhexidine, Irsha, and Oral B mouthwashes can be used for antimicrobial effects, especially on Streptococcus mutans. This chemical activity of mouthwashes is an adjuvant for mechanical removing of plaque. However, the antimicrobial effect of Persicaremains controversial.

  6. Mechanism of resistance to macrolide-lincosamide-streptogramin antibiotics in Streptococcus thermophilus

    USDA-ARS?s Scientific Manuscript database

    Resistance to macrolide-lincosamide-streptogramin (MLS) group antibiotics in the dairy bacterium Streptococcus thermophilus (ST) is documented but the mechanism of resistance has not been elucidated. MIC values for erythromycin (Erm), azithromycin (Azm), tylosin (Tyl), spiramycin (Spm), pristinamyci...

  7. Antibiotic Resistances of Yogurt Starter Cultures Streptococcus thermophilus and Lactobacillus bulgaricus.

    PubMed

    Sozzi, T; Smiley, M B

    1980-11-01

    Twenty-nine strains of Lactobacillus bulgaricus and 15 strains of Streptococcus thermophilus were tested for resistance to 35 antimicrobial agents by using commercially available sensitivity disks. Approximately 35% of the isolates had uncharacteristic resistance patterns.

  8. Antibiotic Resistances of Yogurt Starter Cultures Streptococcus thermophilus and Lactobacillus bulgaricus

    PubMed Central

    Sozzi, Tommaso; Smiley, Martin B.

    1980-01-01

    Twenty-nine strains of Lactobacillus bulgaricus and 15 strains of Streptococcus thermophilus were tested for resistance to 35 antimicrobial agents by using commercially available sensitivity disks. Approximately 35% of the isolates had uncharacteristic resistance patterns. PMID:16345654

  9. Bath immersion, booster vaccination strategy holds potential for protecting juvenile tilapia against Streptococcus iniae

    USDA-ARS?s Scientific Manuscript database

    Streptococcus iniae is a significant bacterial pathogen that causes hemorrhagic septicemia and meningoencephalitis in tilapia, hybrid striped bass, rainbow trout, olive flounder, yellowtail, barramundi and other species of cultured and wild fish worldwide. In tilapia production, vaccination of fry ...

  10. Evaluation of nine teat dip formulations under experimental challenge to staphylococcus aureus and streptococcus agalactiae.

    PubMed

    Pankey, J W; Philpot, W N; Boddie, R L; Watts, J L

    1983-01-01

    Nine postmilking teat dips were evaluated by an experimental challenge model against either Staphylococcus aureus, Streptococcus agalactiae, or both. Formulations containing .9 and .6% sodium hypochlorite, 1% sodium dichloro-s-triazene-trione, .55% chlorhexidine gluconate, and .35% povidone iodine reduced incidence of Staphylococcus aureus infections 56.8, 28.3, 75.9, 92.5, and 77.9%. Incidence of infections with Streptococcus agalactiae was reduced 48.1 and 63.2% by 1.7 and 1% sodium dichloro-s-triazene-trione formulations. The 1% chlorhexidine gluconate and .35% povidone iodine products reduced Streptococcus agalactiae infections 71.0 and 67.0%. Three experimental 1% iodophor formulations reduced Streptococcus agalactiae infections 28.9, 44.8, and 50.7%. The experimental challenge model was refined further and provided an efficient method to determine efficacy of postmilking teat dips.

  11. Effects of Salts and Metal Oxides on Electrochemical and Optical Properties of Streptococcus mutans

    NASA Astrophysics Data System (ADS)

    Kawai, Tsuyoshi; Nagame, Seigo; Kambara, Masaki; Yoshino, Katsumi

    1994-10-01

    The effects of calcium salts and metal oxide powders on electrochemical, optical and biological properties of Streptococcus mutans have been studied as a novel method to determine the strain. Electrochemical signals of Streptococcus mutans show remarkable decrease in the presence of saturated calcium salts such as CaHPO4, Ca3(PO4)2, and Ca5(PO4)3OH depending on the strains of Streptococcus mutans: Ingbritt, NCTC-10449, or GS-5. The number of viable cells also decreases upon addition of these powders. The effects of metal oxides such as ZnO and BaTiO3 on the electrochemical characteristics and photoluminescence of Streptococcus mutans have also been studied.

  12. Draft Genome Sequence of Streptococcus orisasini SH06, Isolated from a Healthy Thoroughbred Gastrointestinal Tract

    PubMed Central

    Takagi, Misako; Nakano, Akiyo; Toh, Hidehiro; Oshima, Kenshiro; Arakawa, Kensuke; Nakajima, Fumihiko; Tashiro, Kosuke; Kikusui, Tekefumi; Yanagida, Fujitoshi

    2016-01-01

    Streptococcus orisasini SH06 was isolated from a healthy thoroughbred gastrointestinal tract. Here, we report the draft genome sequence of this organism. This paper is the first published report of the genomic sequence of S. orisasini. PMID:26769944

  13. Lactose metabolism by Streptococcus mutans: evidence for induction of the tagatose 6-phosphate pathway.

    PubMed Central

    Hamilton, I R; Lebtag, H

    1979-01-01

    Growth on lactose by strains of Streptococcus mutans resulted in the induction of the lactose-phosphoenolpyruvate-phosphotransferase system, phospho-beta-galactosidase, and the enzymes of the tagatose 6-phosphate pathway. PMID:230175

  14. Differentiation of human and animal strains of Streptococcus dysgalactiae by pulsed-field gel electrophoresis.

    PubMed

    Bert, F; Branger, C; Poutrel, B; Lambert-Zechovsky, N

    1997-05-01

    The genetic diversity among 54 human isolates and 33 animal isolates belonging to the species Streptococcus dysgalactiae (20 alpha-haemolytic Streptococcus dysgalactiae, 23 Streptococcus equisimilis, 43 group G streptococci and one group L streptococcus) was evaluated by macrorestriction analysis of chromosomal DNA with SmaI and resolution by pulsed-field gel electrophoresis. This technique revealed a high degree of intraspecies polymorphism, leading to the differentiation of 80 distinct banding patterns, and identified the presence of two major clusters, one containing isolates of human origin and the other isolates of animal origin. These results suggest than human and animal isolates of S.dysgalactiae are genetically distinct, and support the recent proposal of the subspecies S. dysgalactiae subsp. equisimilis for human isolates. The heterogeneity revealed within isolates from the same host type indicates that pulsed-field gel electrophoresis is a powerful epidemiological tool for studying S. dysgalactiae infections.

  15. Fatal Streptococcus pneumoniae Sepsis in a Patient With Celiac Disease-Associated Hyposplenism

    PubMed Central

    Ouseph, Madhu M.; Simons, Malorie; Treaba, Diana O.; Yakirevich, Evgeny; Green, Peter H.; Bhagat, Govind; Moss, Steven F.

    2016-01-01

    We present a 59-year-old male with poorly controlled celiac disease (CD) and fatal Streptococcus pneumoniae sepsis, describe the morphologic findings, and stress the need for monitoring splenic function and pneumococcal vaccination in these patients. PMID:27761478

  16. Neonatal Mortality in Puppies Due to Bacteremia by Streptococcus dysgalactiae subsp. dysgalactiae

    PubMed Central

    Vela, Ana I.; Falsen, Enevold; Simarro, Isabel; Rollan, Eduardo; Collins, Matthew D.; Domínguez, Lucas; Fernandez-Garayzabal, Jose F.

    2006-01-01

    We report a case of bacteremia in puppies caused by Streptococcus dysgalactiae subsp. dysgalactiae. Identification was achieved by phenotypic and molecular genetic methods. This is the first report of the recovery of S. dysgalactiae subsp. dysgalactiae from dogs. PMID:16455943

  17. Vaccine development for protection against systemic infections with Streptococcus suis and Haemophilus parasuis in swine

    USDA-ARS?s Scientific Manuscript database

    Both Streptococcus suis and Haemophilus parasuis are important invasive bacterial pathogens of swine, commonly causing meningitis, arthritis, polyserositis, and septicemia. Due to the presence of many serotypes and high genotypic variability, efficacious vaccines are not readily available. We are us...

  18. Megaplasmids encode differing combinations of lantibiotics in Streptococcus salivarius.

    PubMed

    Wescombe, Philip A; Burton, Jeremy P; Cadieux, Peter A; Klesse, Nikolai A; Hyink, Otto; Heng, Nicholas C K; Chilcott, Chris N; Reid, Gregor; Tagg, John R

    2006-10-01

    Streptococcus salivarius strains commonly produce bacteriocins as putative anti-competitor or signalling molecules. Here we report that bacteriocin production by the oral probiotic strain S. salivarius K12 is encoded by a large (ca. 190 kb) plasmid. Oral cavity transmission of the plasmid from strain K12 to a plasmid-negative variant of this bacterium was demonstrated in two subjects. Tests of additional S. salivarius strains showed large (up to ca. 220 kb) plasmids present in bacteriocin-producing isolates. Various combinations (up to 3 per plasmid) of loci encoding the known streptococcal lantibiotics salivaricin A, salivaricin B, streptin and SA-FF22 were localised to these plasmids. Since all bacteriocin-producing strains of S. salivarius tested to date appear to harbour plasmids, it appears that they may function as mobile repositories for bacteriocin loci, especially those of the lantibiotic class.

  19. Monoclonal antibodies to the extracellular glucosyltransferases from Streptococcus sobrinus 6715.

    PubMed Central

    McCabe, M M; Alberts, M; Stein, J

    1987-01-01

    Murine monoclonal antibodies (MAbs) were raised against the glucosyltransferases (GTFs) of Streptococcus sobrinus 6715. The antibody panels included MAbs raised against the primer-independent, soluble product enzyme (GTF-Si) which did not cross-react with other GTFs, as well as MAbs raised against the primer-dependent, soluble product enzyme (GTF-Sd) which recognized both GTF-Si and GTF-Sd, thus indicating that these catalytically distinct enzymes share epitopes. MAbs raised against GTF-I recognized several forms of GTF-I and did not cross-react with the GTF-S enzymes. None of the MAbs recognized the major glucan-binding protein of S. sobrinus. Two MAbs inhibited glucan synthesis, one blocking primer synthesis by GTF-Si by 89% and the second inhibiting that by GTF-I by 92%. Images PMID:2956196

  20. Streptococcus viridans tubo-ovarian abscess in an adolescent virgin.

    PubMed

    Simpson-Camp, Lashondria; Richardson, Elizabeth Jane; Alaish, Samuel M

    2012-10-01

    A tubo-ovarian abscess (TOA) is a common complication of pelvic inflammatory disease in premenopausal women; however, in virginal females, TOAs are an exceedingly rare occurrence. Within this rare subset of patients, there is almost always an underlying condition, such as vaginal voiding, or a concomitant disease process. A virginal adolescent female with no prior medical history presented with a large pelvic mass which proved to be a TOA. An exploratory laparotomy was eventually required to establish the diagnosis. Open drainage and antibiotic therapy successfully treated the patient. With only the organism, Streptococcus viridians, isolated in her cultures, an etiology of direct ascension from the lower genitourinary tract is implicated. We believe this to be the youngest case of a TOA occurring in a virginal adolescent female without a predisposing condition. A TOA should be considered in the differential diagnosis of pelvic masses in previously healthy pediatric patients regardless of their sexual activity.

  1. Glucosyltransferase from Streptococcus sobrinus Catalyzes Glucosylation of Catechin.

    PubMed

    Nakahara, K; Kontani, M; Ono, H; Kodama, T; Tanaka, T; Ooshima, T; Hamada, S

    1995-07-01

    We previously showed that the polymeric forms of polyphenols present in oolong tea extract exhibited strong inhibitory activities against glucosyltransferases (GTases) of mutans streptococci, while green tea extract, which is rich in catechins, did not show such GTase-inhibitory activities. In this study, (+)-catechin [2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-3,5,7-triol] was found to be glucosylated by the GTase of Streptococcus sobrinus 6715 with sucrose as the substrate, and the product was identified as 4(prm1)-O-(alpha)-d-glucopyranosyl-(+)-catechin, with a molecular weight of 452. The (alpha)-glucosylated (+)-catechin did not exhibit significant inhibition of glucan synthesis from sucrose by the GTase, which is in contrast to the polymeric polyphenols isolated from oolong tea leaves.

  2. Genetic patterns of Streptococcus uberis isolated from bovine mastitis.

    PubMed

    Reinoso, Elina B; Lasagno, Mirta C; Odierno, Liliana M

    2015-01-01

    The aim of this study was to evaluate the genotypic relationships among 40 Streptococcus uberis isolated from bovine mastitis by using pulsed-field gel electrophoresis (PFGE). Additionally, the association between PFGE patterns and virulence profiles was investigated. The isolates exhibited 17 PFGE patterns. Different strains were found within and among herds; however, a low number of isolates within the same herd shared an identical PFGE type. No association between PFGE patterns and virulence profiles was found. However, the detection of specific strains in some herds could indicate that some strains are more virulent than others. Further research needs to be undertaken to elucidate new virulence-associated genes that might contribute to the capability of these strains to produce infection.

  3. Fatal necrotizing fasciitis due to Streptococcus pneumoniae: a case report.

    PubMed

    Park, So-Youn; Park, So Young; Moon, Soo-Youn; Son, Jun Seong; Lee, Mi Suk

    2011-01-01

    Necrotizing fasciitis is known to be a highly lethal infection of deep-seated subcutaneous tissue and superficial fascia. Reports of necrotizing fasciitis due to Streptococcus pneumoniae are exceedingly rare. We report a case of necrotizing fasciitis in a 62-yr-old man with liver cirrhosis and diabetes mellitus. He presented with painful swelling of left leg and right hand. On the day of admission, compartment syndrome was aggravated and the patient underwent surgical exploration. Intra-operative findings revealed necrotizing fasciitis and cultures of two blood samples and wound aspirates showed S. pneumoniae. The patient died despite debridement and proper antimicrobial treatment. To the best of our knowledge, this is the first case of fatal necrotizing fasciitis with meningitis reported in Korea. We also review and discuss the literature on pneumococcal necrotizing fasciitis.

  4. Regulation and Function of Lactate Oxidation in Streptococcus faecium

    PubMed Central

    London, Jack

    1968-01-01

    Regulation of the synthesis and function of an l(+)-specific lactate-oxidizing enzyme system found in a homofermentative Streptococcus was investigated. With the exception of fructose, aerobic growth at the expense of a variety of substrates resulted in the formation of a lactate oxidation system; anaerobic growth resulted in a marked reduction or complete loss of lactate-oxidizing activity. Growth on fructose, under aerobic and anaerobic conditions, invariably produced a decrease in the activity of the lactate oxidation system. A negative control, activated by an early intermediate product of glycolysis, appeared to be responsible for repression of the lactate-oxidizing enzyme(s). The enzyme system confers upon the organism the ability to grow aerobically at the expense of l(+)-lactic acid. PMID:5646625

  5. Insertional mutagenesis of an industrial strain of Streptococcus thermophilus.

    PubMed

    Labarre, C; Schirawski, J; van der Zwet, A; Fitzgerald, G F; van Sinderen, D

    2001-06-12

    Random mutagenesis of an industrial strain of Streptococcus thermophilus was achieved through an adapted version of a two-plasmid system. The mutagenesis strategy is based on random integration of derivatives of the non-replicative (Rep(-)) plasmid pORI19 by means of homologous recombination following a temperature shift that eliminates replication of the temperature-sensitive (Rep(ts)) helper plasmid pVE6007. In this way mutants were generated which were affected in bacteriophage sensitivity or sucrose metabolism. Homologues were identified of a protein related to folate metabolism from a bacteriophage-resistant mutant and of two subunits of an oligopeptide transport system from a mutant deficient in sucrose utilisation.

  6. Late, Late-Onset Group B Streptococcus Cellulitis With Bacteremia.

    PubMed

    Yokouchi, Yukako; Katsumori, Hiroshi; Koike, Yuji

    2016-01-01

    Group B streptococcus (GBS) infection remains a leading cause of serious neonatal and early infantile infection. As the infection often presents with nonspecific symptoms, and is associated with underlying bacteremia, prompt investigation and treatment is required. We report a case of late, late-onset GBS infection with bacteremia in a 94-day-old boy experiencing cellulitis of the left hand. Although late-onset disease or late, late-onset disease has been reported to be common among infants with underlying conditions such as premature birth, immunocompromised status, trauma, or among those using medical devices, no such underlying medical condition predisposed this infant to invasive GBS infection. Recent reports including the present case underscore the risk of GBS infection among previously healthy infants beyond the neonatal period. Thus, clinicians should especially be aware of unusual presentations of GBS invasive disease with bacteremia.

  7. [Study on the mechanism of erythritol effecting on Streptococcus mutans].

    PubMed

    Yao, Jun; Zhang, Jiali

    2012-02-01

    To evaluate the effect of erythritol on cell wall structure of Streptococcus mutans (S. mutans) and explore its potential mechanism. Enzyme activities of lactate dehydrogenase (LDH) in bacterial solution were detected under respective condition of sucrose and erythritol. A scanning electron microscope (SEM) was used to investigate the change of S. mutans' cell wall under the condition of sucrose and erythritol. Enzyme activities of LDH in erythritol culture medium were different from that in sucrose, but the difference was slight. SEM observation showed the integrity of cell wall was not destroyed and no content leaked out. It's suggested that erythritol has an antibacterial effect on S. mutans through no affecting on the normal structure of the cell wall of S. mutans.

  8. Treatment of Streptococcus mutans bacteria by a plasma needle

    SciTech Connect

    Zhang Xianhui; Huang Jun; Lv Guohua; Liu Xiaodi; Peng Lei; Guo Lihong; Chen Wei; Feng Kecheng; Yang Size

    2009-03-15

    A dielectric barrier discharge plasma needle was realized at atmospheric pressure with a funnel-shaped nozzle. The preliminary characteristics of the plasma plume and its applications in the inactivation of Streptococcus mutans (S. mutans), the most important microorganism causing dental caries, were presented in this paper. The temperature of the plasma plume does not reach higher than 315 K when the power is below 28 W. Oxygen was injected downstream in the plasma afterglow region through the powered steel tube. Its effect was studied via optical-emission spectroscopy, both in air and in agar. Results show that addition of 26 SCCM O{sub 2} does not affect the plume length significantly (SCCM denotes cubic centimeter per minute at STP). The inactivation of S. mutans is primarily attributed to ultraviolet light emission, O, OH, and He radicals.

  9. In Vitro Antibacterial Activity of Essential Oils against Streptococcus pyogenes.

    PubMed

    Sfeir, Julien; Lefrançois, Corinne; Baudoux, Dominique; Derbré, Séverine; Licznar, Patricia

    2013-01-01

    Streptococcus pyogenes plays an important role in the pathogenesis of tonsillitis. The present study was conducted to evaluate the in vitro antibacterial activities of 18 essential oils chemotypes from aromatic medicinal plants against S. pyogenes. Antibacterial activity of essential oils was investigated using disc diffusion method. Minimum Inhibitory Concentration of essential oils showing an important antibacterial activity was measured using broth dilution method. Out of 18 essential oils tested, 14 showed antibacterial activity against S. pyogenes. Among them Cinnamomum verum, Cymbopogon citratus, Thymus vulgaris CT thymol, Origanum compactum, and Satureja montana essential oils exhibited significant antibacterial activity. The in vitro results reported here suggest that, for patients suffering from bacterial throat infections, if aromatherapy is used, these essential oils, considered as potential antimicrobial agents, should be preferred.

  10. Aromatic Esters of Bicyclic Amines as Antimicrobials against Streptococcus pneumoniae.

    PubMed

    de Gracia Retamosa, María; Díez-Martínez, Roberto; Maestro, Beatriz; García-Fernández, Esther; de Waal, Bas; Meijer, E W; García, Pedro; Sanz, Jesús M

    2015-11-09

    A double approach was followed in the search of novel inhibitors of the surface choline-binding proteins (CBPs) of Streptococcus pneumoniae (pneumococcus) with antimicrobial properties. First, a library of 49 rationally-designed esters of alkyl amines was screened for their specific binding to CBPs. The best binders, being esters of bicyclic amines (EBAs), were then tested for their in vitro effect on pneumococcal growth and morphology. Second, the efficiency of EBA-induced CBP inhibition was enhanced about 45,000-fold by multivalency effects upon synthesizing a poly(propylene imine) dendrimer containing eight copies of an atropine derivative. Both approaches led to compounds that arrest bacterial growth, dramatically decrease cell viability, and exhibit a protection effect in animal disease models, demonstrating that the pneumococcal CBPs are adequate targets for the discovery of novel antimicrobials that overcome the currently increasing antimicrobial resistance issues.

  11. In Vitro Antibacterial Activity of Essential Oils against Streptococcus pyogenes

    PubMed Central

    Sfeir, Julien; Lefrançois, Corinne; Baudoux, Dominique; Derbré, Séverine; Licznar, Patricia

    2013-01-01

    Streptococcus pyogenes plays an important role in the pathogenesis of tonsillitis. The present study was conducted to evaluate the in vitro antibacterial activities of 18 essential oils chemotypes from aromatic medicinal plants against S. pyogenes. Antibacterial activity of essential oils was investigated using disc diffusion method. Minimum Inhibitory Concentration of essential oils showing an important antibacterial activity was measured using broth dilution method. Out of 18 essential oils tested, 14 showed antibacterial activity against S. pyogenes. Among them Cinnamomum verum, Cymbopogon citratus, Thymus vulgaris CT thymol, Origanum compactum, and Satureja montana essential oils exhibited significant antibacterial activity. The in vitro results reported here suggest that, for patients suffering from bacterial throat infections, if aromatherapy is used, these essential oils, considered as potential antimicrobial agents, should be preferred. PMID:23662123

  12. Splenic abscess in an infant caused by Streptococcus intermedius.

    PubMed

    Matsubayashi, Tadashi; Matsubayashi, Rie; Saito, Isamu; Tobayama, Shigeo; Machida, Hiromichi

    2007-12-01

    We report a 20-month-old girl with splenic abscess. The patient was admitted to our hospital because of persistent high fever and abdominal pain. Laboratory data showed leucocytosis and elevated C-reactive protein levels. Abdominal computed tomography showed multiple low-density lesions in the spleen. These findings were consistent with a diagnosis of splenic abscess. She was successfully treated with ultrasonographically guided percutaneous drainage for 11 days and intravenous antibiotic for 17 days. On culture, aspirated fluid from the abscess grew Streptococcus intermedius. This case illustrates that the differential diagnosis of unknown-focus infection in infants should include splenic abscess. We recommend conservative therapy (antibiotics and drainage) as first-line therapy for splenic abscess in pediatric patients, based on the importance of the immunological functions of the spleen.

  13. The role of Streptococcus intermedius in brain abscess.

    PubMed

    Mishra, A K; Fournier, P-E

    2013-04-01

    Brain abscess represents a significant medical problem, despite recent advances made in detection and therapy. Streptococcus intermedius, a commensal organism, has the potential to cause significant morbidity. S. intermedius expresses one or more members of a family of structurally and antigenically related surface proteins termed antigen I/II, which plays a potential role in its pathogenesis. It is involved in binding to human fibronectin and laminin and in inducing IL-8 release from monocytes, which promotes neutrophil chemotaxis and activation. There are few published data on the role of this organism in brain abscess. This review focuses on the clinical evidence, pathogenic role, mechanism of predisposition, and currently employed strategies to fight against S. intermedius associated to brain abscess.

  14. Pleural effusion Due to Streptococcus milleri: Case descriptions.

    PubMed

    Madrid-Carbajal, Claudia Janeth; Molinos, Luis; García-Clemente, Marta; Pando-Sandoval, Ana; Fleites, Ana; Casan-Clarà, Pere

    2014-09-01

    In this study we analyzed the characteristics of patients with pleural effusion secondary to Streptococcus milleri studied retrospectively between January and March 2013 and found seven patients with a mean age of 60 years, 43% of which were smokers and 57% with a drinking habit. The most common associated factors were alcoholism, previous pneumonia and diabetes. Other bacteria were identified as Enterobacter aerogenes, Bacteroides and Prevotella intermedia capillosus in two patients. The mean duration of antibiotic therapy was 28 days; six patients underwent pleural drainage by chest tube and one patient needed surgery due to poor clinical progress. The mean duration of hospitalization was 30 days with satisfactory outcome in all cases, despite some changes in residual function. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

  15. Interpreting Assays for the Detection of Streptococcus pneumoniae

    PubMed Central

    2011-01-01

    Streptococcus pneumoniae is both an aggressive pathogen and a normal part of the human respiratory microbiome. Clinicians and microbiologists have struggled to develop tests that can identify pneumococcal respiratory infection and accurately distinguish colonization from invasive disease. Molecular methods hold the promise of an improved ability to rapidly detect microorganisms in respiratory secretions and to make an accurate diagnosis; however, interpretation of diagnostic testing for S. pneumoniae remains problematic. Molecular assays, such as those targeting the pneumolysin gene, may cross-react with other streptococcal species, confounding detection and quantification. Assays that target the autolysin gene appear to be more specific. Even when accurately identified, however, the significance of S. pneumoniae DNA detected in clinical samples is difficult to determine. Here we will discuss the challenges faced in the interpretation of molecular testing for S. pneumoniae, and some strategies that might be used to improve our ability to diagnose pneumococcal respiratory infection. PMID:21460292

  16. A rare case of sepsis in newborn: Streptococcus pneumoniae septicemia.

    PubMed

    Karabayir, Nalan; Hatipoglu, Nevin; Adal, Erdal; Sanli, Kamuran

    2010-11-01

    Streptococcus pneumoniae is a rare cause of sepsis in the newborn. The term baby was admitted on complaint of dyspnea, and antibiotherapy was begun after samples for hemocultures were obtained with the suspicion of sepsis according to the clinical and laboratory data. S. pneumoniae was demonstrated in the vaginal culture of the mother of the patient whose lumbar punction and chest roentgenogram were normal but hemoculture revealed the propagation of S. pneumoniae. The patient, treated with antibiotherapy for 14 days, was discharged without any complications. In preventing the probable complications, it is important to absolutely treat the maternal pneumococcal colonization that can cause severe infections in the newborn and also to treat the newborns even if they are asymptomatic.

  17. Treatment of Streptococcus mutans bacteria by a plasma needle

    NASA Astrophysics Data System (ADS)

    Zhang, Xianhui; Huang, Jun; Liu, Xiaodi; Peng, Lei; Guo, Lihong; Lv, Guohua; Chen, Wei; Feng, Kecheng; Yang, Si-ze

    2009-03-01

    A dielectric barrier discharge plasma needle was realized at atmospheric pressure with a funnel-shaped nozzle. The preliminary characteristics of the plasma plume and its applications in the inactivation of Streptococcus mutans (S. mutans), the most important microorganism causing dental caries, were presented in this paper. The temperature of the plasma plume does not reach higher than 315 K when the power is below 28 W. Oxygen was injected downstream in the plasma afterglow region through the powered steel tube. Its effect was studied via optical-emission spectroscopy, both in air and in agar. Results show that addition of 26 SCCM O2 does not affect the plume length significantly (SCCM denotes cubic centimeter per minute at STP). The inactivation of S. mutans is primarily attributed to ultraviolet light emission, O, OH, and He radicals.

  18. Clinical analysis of cases of neonatal Streptococcus agalactiae sepsis.

    PubMed

    Zeng, S J; Tang, X S; Zhao, W L; Qiu, H X; Wang, H; Feng, Z C

    2016-06-17

    With the advent of antibiotic resistance, pathogenic bacteria have become a major threat in cases of neonatal sepsis; however, guidelines for treatment have not yet been standardized. In this study, 15 cases of neonatal Streptococcus agalactiae sepsis from our hospital were retrospectively analyzed. Of these, nine cases showed early-onset and six cases showed late-onset sepsis. Pathogens were characterized by genotyping and antibiotic sensitivity tests on blood cultures. Results demonstrated that in cases with early-onset sepsis, clinical manifestations affected mainly the respiratory tract, while late-onset sepsis was accompanied by intracranial infection. Therefore, we suggest including a cerebrospinal fluid examination when diagnosing neonatal sepsis. Bacterial genotyping indicated the bacteria were mainly type Ib, Ia, and III S. agalactiae. We recommend treatment with penicillin or ampicillin, since bacteria were resistant to clindamycin and tetracycline. In conclusion, our results provide valuable information for the clinical treatment of S. agalactiae sepsis in neonatal infants.

  19. Streptococcus mutans serotype c tagatose 6-phosphate pathway gene cluster.

    PubMed Central

    Jagusztyn-Krynicka, E K; Hansen, J B; Crow, V L; Thomas, T D; Honeyman, A L; Curtiss, R

    1992-01-01

    DNA cloned into Escherichia coli K-12 from a serotype c strain of Streptococcus mutans encodes three enzyme activities for galactose utilization via the tagatose 6-phosphate pathway: galactose 6-phosphate isomerase, tagatose 6-phosphate kinase, and tagatose-1,6-bisphosphate aldolase. The genes coding for the tagatose 6-phosphate pathway were located on a 3.28-kb HindIII DNA fragment. Analysis of the tagatose proteins expressed by recombinant plasmids in minicells was used to determine the sizes of the various gene products. Mutagenesis of these plasmids with transposon Tn5 was used to determine the order of the tagatose genes. Tagatose 6-phosphate isomerase appears to be composed of 14- and 19-kDa subunits. The sizes of the kinase and aldolase were found to be 34 and 36 kDa, respectively. These values correspond to those reported previously for the tagatose pathway enzymes in Staphylococcus aureus and Lactococcus lactis. Images PMID:1328153

  20. Streptococcus constellatus-associated pyoderma in a dog.

    PubMed

    De Martino, Luisa; Nizza, Sandra; de Martinis, Claudio; Foglia Manzillo, Valentina; Iovane, Valentina; Paciello, Orlando; Pagnini, Ugo

    2012-03-01

    This report describes a case of chronic and deep pyodermitis in a 4-year-old male dog with a 3-month skin problems history that had been treated unsuccessfully with fluoroquinolone therapy, prescribed by a private medical veterinary practice, without an early diagnosis. Microbiological examination and antimicrobial susceptibility testing were performed in our laboratory (Faculty of Veterinary Medicine) and a diagnosis of Streptococcus constellatus-associated pyoderma in the dog was made. A new antimicrobial treatment, with tetracyclines, was designed after the definitive diagnosis and antimicrobial susceptibility testing performed by the Kirby-Bauer disc diffusion method. The dog remained free of clinical illness at completion of therapy. To our knowledge, this is the first case of a canine pyoderma caused by S. constellatus, a commensal organism which may also cause pyogenic infections. Furthermore, this study confirms that a fluoroquinolone represents a poor empirical choice for initial therapy of canine pyoderma.

  1. Streptococcus pyogenes degrades extracellular matrix in chondrocytes via MMP-13

    SciTech Connect

    Sakurai, Atsuo; Okahashi, Nobuo; Maruyama, Fumito; Ooshima, Takashi; Hamada, Shigeyuki; Nakagawa, Ichiro

    2008-08-29

    Group A streptococcus (GAS) causes a wide range of human diseases, including bacterial arthritis. The pathogenesis of arthritis is characterized by synovial proliferation and the destruction of cartilage and subchondral bone in joints. We report here that GAS strain JRS4 invaded a chondrogenic cell line ATDC5 and induced the degradation of the extracellular matrix (ECM), whereas an isogenic mutant of JRS4 lacking a fibronectin-binding protein, SAM1, failed to invade the chondrocytes or degrade the ECM. Reverse transcription-PCR and Western blot analysis revealed that the expression of matrix metalloproteinase (MMP)-13 was strongly elevated during the infection with GAS. A reporter assay revealed that the activation of the AP-1 transcription factor and the phosphorylation of c-Jun terminal kinase participated in MMP-13 expression. These results suggest that MMP-13 plays an important role in the destruction of infected joints during the development of septic arthritis.

  2. Purulent pericarditis and pneumonia caused by Streptococcus equi subsp. zooepidemicus.

    PubMed

    Held, Jürgen; Schmitz, Roland; van der Linden, Mark; Nührenberg, Thomas; Häcker, Georg; Neumann, Franz-Josef

    2014-02-01

    Purulent pericarditis is a life-threatening disease that usually manifests following bacteraemia or through spreading from an intrathoracic focus. Only a few cases of this disease have been reported with Lancefield group C streptococci as aetiological agents, and the primary focus in these infections remains unknown. We report a case of purulent pericarditis with septic and cardiogenic shock, caused by Streptococcus equi subsp. zooepidemicus (group C) in a 51-year-old patient. The pathogen was possibly contracted through contact with horses. Most probably, it caused initially pneumonia before spreading to the pericardium, either directly or via the bloodstream. A combined therapeutic approach, consisting of antibiotic therapy and repeated pericardial drainage, was necessary to ensure a clinical cure. After discharge, long-term follow-up for development of constrictive pericarditis is considered mandatory.

  3. Single Cell Bottlenecks in the Pathogenesis of Streptococcus pneumoniae

    PubMed Central

    Zafar, M. Ammar; Zuniga, Marisol; Roche, Aoife M.; Hamaguchi, Shigeto; Weiser, Jeffrey N.

    2016-01-01

    Herein, we studied a virulent isolate of the leading bacterial pathogen Streptococcus pneumoniae in an infant mouse model of colonization, disease and transmission, both with and without influenza A (IAV) co-infection. To identify vulnerable points in the multiple steps involved in pneumococcal pathogenesis, this model was utilized for a comprehensive analysis of population bottlenecks. Our findings reveal that in the setting of IAV co-infection the organism must pass through single cell bottlenecks during bloodstream invasion from the nasopharynx within the host and in transmission between hosts. Passage through these bottlenecks was not associated with genetic adaptation by the pathogen. The bottleneck in transmission occurred between bacterial exit from one host and establishment in another explaining why the number of shed organisms in secretions is critical to overcoming it. These observations demonstrate how viral infection, and TLR-dependent innate immune responses it stimulates and that are required to control it, drive bacterial contagion. PMID:27732665

  4. Streptococcus suis Sequence Type 7 Outbreak, Sichuan, China

    PubMed Central

    Ye, Changyun; Zhu, Xiaoping; Jing, Huaiqi; Du, Huamao; Segura, Mariela; Zheng, Han; Kan, Biao; Wang, Lili; Bai, Xuemei; Zhou, Yongyun; Cui, Zhigang; Zhang, Shouying; Jin, Dong; Sun, Na; Luo, Xia; Zhang, Ji; Gong, Zhaolong; Wang, Xin; Wang, Lei; Sun, Hui; Li, Zhenjun; Sun, Qiangzheng; Liu, Honglu; Dong, Boqing; Ke, Changwen; Yuan, Hui; Wang, Hua; Tian, Kecheng; Wang, Yu; Gottschalk, Marcelo

    2006-01-01

    An outbreak of Streptococcus suis serotype 2 emerged in the summer of 2005 in Sichuan Province, and sporadic infections occurred in 4 additional provinces of China. In total, 99 S. suis strains were isolated and analyzed in this study: 88 isolates from human patients and 11 from diseased pigs. We defined 98 of 99 isolates as pulse type I by using pulsed-field gel electrophoresis analysis of SmaI-digested chromosomal DNA. Furthermore, multilocus sequence typing classified 97 of 98 members of the pulse type I in the same sequence type (ST), ST-7. Isolates of ST-7 were more toxic to peripheral blood mononuclear cells than ST-1 strains. S. suis ST-7, the causative agent, was a single-locus variant of ST-1 with increased virulence. These findings strongly suggest that ST-7 is an emerging, highly virulent S. suis clone that caused the largest S. suis outbreak ever described. PMID:16965698

  5. Characteristics of Streptococcus suis isolated from patients in Japan.

    PubMed

    Chang, Bin; Wada, Akihito; Ikebe, Tadayoshi; Ohnishi, Makoto; Mita, Kazuhito; Endo, Miyoko; Matsuo, Hirosuke; Asatuma, Yoshinori; Kuramoto, Sanae; Sekiguchi, Hiroshi; Yamazaki, Motoyosi; Yoshikawa, Hiroko; Watabe, Nobuei; Yamada, Hideko; Kurita, Shohachi; Imai, Yumiko; Watanabe, Haruo

    2006-12-01

    Seven cases of Streptococcus suis infection in Japan during 1994 and 2006 were summarized. All cases had porcine exposure and five of them had hand skin injury during the exposure. Five cases presented symptoms of meningitis, three presented symptoms of sepsis, and one resulted in sudden death. All of the isolated S. suis belonged to Lancefield's group D and to serotype 2. They were susceptible to penicillin G, ampicillin, cefotaxime, and ciprofloxacin. However, six of them were resistant to both erythromycin and clindamycin, and four were also resistant to minocycline. Multilocus sequence typing of six isolates showed that they belonged to sequence type (ST) 1, and their pulsed-field gel electrophoresis (PFGE) patterns were similar. The remaining isolate was ST28 and its PFGE pattern was distinct from those of the others.

  6. Streptococcus suis infection in swine. A sixteen month study.

    PubMed Central

    Higgins, R; Gottschalk, M; Mittal, K R; Beaudoin, M

    1990-01-01

    A total of 349 isolates of Streptococcus suis retrieved from different tissues from diseased pigs were examined in this study. Only 48% of them could be categorized as one of serotypes 1 to 8 and 1/2. Among typable isolates, serotype 2 was the most prevalent (23%), followed by serotype 3 (10%). The majority of all isolates originated from lungs, meninges/brain, and multiple tissues. Forty-one percent of typable isolates and 33% of untypable isolates were retrieved in pure culture. Other isolates were found in conjunction with Pasteurella multocida, Escherichia coli, Actinobacillus pleuropneumoniae, Actinomyces pyogenes, and other streptococci. Typable S. suis isolates were more frequently isolated from pigs between five and ten weeks of age, while untypable isolates were mostly found in animals aged more than 24 weeks. No obvious monthly and/or seasonal variation of the prevalence of isolation of S. suis could be detected. PMID:2306668

  7. Evaluation of Melia azedarach extracts against Streptococcus mutans.

    PubMed

    Della Bona, Alvaro; Nedel, Fernanda

    2015-02-01

    Although the incidence of caries worldwide has declined in recent years, it is necessary to search for new means to overcome this disease and its microbiological agents. Phytochemistry can become an effective alternative to antibiotics, offering a promising strategy in the prevention and therapy of dental caries. This study aimed to evaluate in vitro the bactericide activity of a bioactive phytocomponent from Melia azedarach against Streptococcus mutans. The crude extract (CEx) from leaves and stem barks of M. azedarach in chloroform, petroleum ether, acetate ethyl, butanol, and aqueous fractions was evaluated using seven different concentrations. Disk diffusion and minimum inhibitory concentration assays were used to evaluate the antibacterial activity. 0.12% chlorhexidine was used as a positive control. The CEx and the petroleum ether fraction from M. azedarach showed significant antibacterial activity against S. mutans, confirming its antibiotic potential.

  8. Red drum Sciaenops ocellatus mortalities associated with Streptococcus iniae infection.

    PubMed

    Eldar, A; Perl, S; Frelier, P F; Bercovier, H

    1999-05-12

    We isolated for the first time Streptococcus iniae strains associated with diseased marine fish. Diseased red drum Sciaenops ocellatus were lethargic, and presented external signs (exophthalmia and loss of orientation) resembling those of freshwater fish infected by S. iniae. Skin lesions, extending to a necrotizing myositis, were typical of S. iniae infection of red drum. Histopathological findings indicate that S. iniae infection in red drum produces a chronic disease with systemic involvement characterized by multiple necrotic foci. Molecular epidemiology (RFLP [restriction fragment length polymorphism] ribotyping) revealed that 2 different ribotypes were involved in a single outbreak. The first is the EcoRI 'Israeli' trout and tilapine ribotype (Hind III type a strains), while the second is the EcoRI 'American' ribotype (Hind III type b strains), typical of tilapines farmed in Texas and Idaho.

  9. Involvement of NADH Oxidase in Biofilm Formation in Streptococcus sanguinis

    PubMed Central

    Ge, Xiuchun; Shi, Xiaoli; Shi, Limei; Liu, Jinlin; Stone, Victoria; Kong, Fanxiang; Kitten, Todd; Xu, Ping

    2016-01-01

    Biofilms play important roles in microbial communities and are related to infectious diseases. Here, we report direct evidence that a bacterial nox gene encoding NADH oxidase is involved in biofilm formation. A dramatic reduction in biofilm formation was observed in a Streptococcus sanguinis nox mutant under anaerobic conditions without any decrease in growth. The membrane fluidity of the mutant bacterial cells was found to be decreased and the fatty acid composition altered, with increased palmitic acid and decreased stearic acid and vaccenic acid. Extracellular DNA of the mutant was reduced in abundance and bacterial competence was suppressed. Gene expression analysis in the mutant identified two genes with altered expression, gtfP and Idh, which were found to be related to biofilm formation through examination of their deletion mutants. NADH oxidase-related metabolic pathways were analyzed, further clarifying the function of this enzyme in biofilm formation. PMID:26950587

  10. Endothelial cells are intrinsically defective in xenophagy of Streptococcus pyogenes

    PubMed Central

    Lu, Shiou-Ling; Kawabata, Tsuyoshi; Cheng, Yi-Lin; Omori, Hiroko; Hamasaki, Maho; Kusaba, Tatsuya; Iwamoto, Ryo; Lin, Yee-Shin

    2017-01-01

    Group A Streptococcus (GAS) is deleterious pathogenic bacteria whose interaction with blood vessels leads to life-threatening bacteremia. Although xenophagy, a special form of autophagy, eliminates invading GAS in epithelial cells, we found that GAS could survive and multiply in endothelial cells. Endothelial cells were competent in starvation-induced autophagy, but failed to form double-membrane structures surrounding GAS, an essential step in xenophagy. This deficiency stemmed from reduced recruitment of ubiquitin and several core autophagy proteins in endothelial cells, as demonstrated by the fact that it could be rescued by exogenous coating of GAS with ubiquitin. The defect was associated with reduced NO-mediated ubiquitin signaling. Therefore, we propose that the lack of efficient clearance of GAS in endothelial cells is caused by their intrinsic inability to target GAS with ubiquitin to promote autophagosome biogenesis for xenophagy. PMID:28683091

  11. Recognition of Streptococcus pneumoniae by the innate immune system.

    PubMed

    Koppe, Uwe; Suttorp, Norbert; Opitz, Bastian

    2012-04-01

    Streptococcus pneumoniae is both a frequent colonizer of the upper respiratory tract and a leading cause of life-threatening infections such as pneumonia, meningitis and sepsis. The innate immune system is critical for the control of colonization and for defence during invasive disease. Initially, pneumococci are recognized by different sensors of the innate immune system called pattern recognition receptors (PRRs), which control most subsequent host defence pathways. These PRRs include the transmembrane Toll-like receptors (TLRs) as well as the cytosolic NOD-like receptors (NLRs) and DNA sensors. Recognition of S. pneumoniae by members of these PRR families regulates the production of inflammatory mediators that orchestrate the following immune response of infected as well as neighbouring non-infected cells, stimulates the recruitment of immune cells such as neutrophils and macrophages, and shapes the adaptive immunity. This review summarizes the current knowledge of the function of different PRRs in S. pneumoniae infection.

  12. Specific detection by PCR of Streptococcus agalactiae in milk.

    PubMed

    Martinez, G; Harel, J; Gottschalk, M

    2001-01-01

    The aim of this study was to develop a simple and specific method for direct detection of Streptococcus agalactiae from cow's milk. The method was based on polymerase chain reaction (PCR) using species-specific and universal primers derived from the 16S rRNA gene. The amplification product was verified by restriction endonuclease digest and sequencing. Specific identification was proven on a collection of 147 S. agalactiae isolates of bovine and human origin. In addition, 17 strains belonging to different bacterial species that potentially can be found in milk samples also tested negative. The PCR developed was used for direct detection of S. agalactiae in milk, using for the first time with gram-positive bacteria the nucleic acid-binding properties of diatomaceous earth. The test, which has high specificity, high sensitivity (100 cfu/mL), and can be carried out in less than 24 h, represents an innovative diagnostic tool for the detection of S. agalactiae in milk.

  13. Salivaricin 9, a new lantibiotic produced by Streptococcus salivarius.

    PubMed

    Wescombe, P A; Upton, M; Renault, P; Wirawan, R E; Power, D; Burton, J P; Chilcott, C N; Tagg, J R

    2011-05-01

    Salivaricin 9 (Sal9) is a 2560 Da lantibiotic having just 46 % amino acid identity with its closest known homologue, the Streptococcus pyogenes lantibiotic SA-FF22. The Sal9 locus (designated siv) in Streptococcus salivarius strain 9 was partially sequenced and localized to an approximately 170 kb megaplasmid, which also harbours the locus for the lantibiotic salivaricin A4. The entire locus was fully characterized in the draft genome sequence of S. salivarius strain JIM8780 and shown to consist of eight genes, having the following putative functions: sivK, sensor kinase; sivR, response regulator; sivA, Sal9 precursor peptide; sivM, lantibiotic modification enzyme; sivT, ABC transporter involved in the export of Sal9 and concomitant cleavage of its leader peptide; and sivFEG, encoding lantibiotic self-immunity. Intriguingly, in contrast to strain 9, the siv locus was chromosomally located in strain JIM8780--the first lantibiotic locus shown not to be exclusively plasmid-associated in S. salivarius. Sal9-containing extracts specifically induced lantibiotic production in both strain 9 and strain JIM8780, indicating that Sal9 functions as a signal peptide for upregulation of its own biosynthesis. Screening representative strains of three streptococcal species (S. salivarius, S. pyogenes and S. mitis) for sivA indicated that it was present only in S. salivarius, with 12 of 28 tested S. salivarius positive. Since Sal9 was inhibitory to all tested S. pyogenes strains it appears to have potential as an important component of the bacteriocin armoury of S. salivarius probiotics intended to control S. pyogenes infections of the human oral cavity.

  14. Characterization of the arginine deiminase of Streptococcus equi subsp. zooepidemicus.

    PubMed

    Hong, Kyongsu

    2006-09-01

    Streptococcus equi subsp. zooepidemicus is an important cause of infectious diseases in horses and rarely humans. Little is known about the virulence factors or protective antigens of S. equi subsp. zooepidemicus. In the present study, I designed original primers based on an alignment of the gene sagp(arcA) from Streptococcus pyogenes encoding streptococcal acid glycoprotein-arginine deiminase (SAGP/AD) to amplify the S. equi subsp. zooepidemicus counterpart sequence by polymerase chain reaction, and I analyzed the sagp(arcA) gene of the organism. Using chromosomal walking steps, I identified a contiguous eight-gene locus involved in SAGP/AD production. Their open reading frames were found to share significant homologies and to correspond closely in molecular mass to previously sequenced arc genes of S. pyogenes, thus they were designated ahrC.2 (arginine repressor), arcR (CRP/FNR transcription regulator), sagp(arcA) (streptococcal acid glycoprotein-arginine deiminase), putative acetyltransferase gene, arcB (ornithine carbamyl transferase), arcD (arginine-ornithine antiporter), arcT (Xaa-His peptidase), and arcC (carbamate kinase). The SAGP homologue of S. equi subsp. zooepidemicus (SzSAGP), encoded by arcA gene of the bacteria (arcA(SZ)), was successfully expressed in Escherichia coli and purified to homogeneity. When in vitro growth inhibitory activity of the recombinant SzSAGP was tested against MOLT-3 cells, it inhibited the growth of the cells during the 3 days of culture in a dose-dependent manner, accompanied by the induction of apoptotic cell death. The recombinant protein also possessed AD activity. By immunoblot analysis using both anti-SzSAGP-SfbI(H8) and anti-SfbI(H8) sera, I was able to demonstrate that the SzSAGP protein is expressed on the streptococcal surface.

  15. Serotype IX, a Proposed New Streptococcus agalactiae Serotype▿

    PubMed Central

    Slotved, Hans-Christian; Kong, Fanrong; Lambertsen, Lotte; Sauer, Susanne; Gilbert, Gwendolyn L.

    2007-01-01

    We identified three isolates of Streptococcus agalactiae (group B streptococcus [GBS]), of human origin, which failed to react with antisera against any of the nine known GBS serotypes. Polyclonal rabbit antisera raised against these isolates and standard GBS typing sera were used in capillary precipitation and Ouchterlony tests to compare the strains with known GBS serotype reference strains. All three previously nontypeable isolates reacted with all three new antisera, producing lines of identity in the Ouchterlony test. Weak cross-reactions with antisera against several GBS serotypes were observed but were removed by absorption with corresponding antigens. The new antisera were used to test 227 GBS isolates that had been nontypeable or difficult to type using standard antisera. Of these, five reacted with the new antisera. These results suggested that all eight isolates belong to the previously unrecognized GBS serotype. They were tested by Western blotting for the Cα and Cβ proteins and by PCR to identify molecular serotypes and surface protein antigen genes. Two segments of the cps gene cluster (3′ end of cpsE-cpsF and 5′ end of cpsG, approximately 700 bp; 3′ end of cpsH and 5′ end of cpsM, approximately 560 bp) were sequenced. All eight isolates expressed Cα, and seven expressing the Cβ protein and the corresponding genes, bca and bac, respectively, were identified. They all share the same, unique partial cps sequence. These results indicate that these eight isolates represent a new S. agalactiae serotype, which we propose should be designated serotype IX. PMID:17634306

  16. The role of coagulation/fibrinolysis during Streptococcus pyogenes infection

    PubMed Central

    Loof, Torsten G.; Deicke, Christin; Medina, Eva

    2014-01-01

    The hemostatic system comprises platelet aggregation, coagulation and fibrinolysis and is a host defense mechanism that protects the integrity of the vascular system after tissue injury. During bacterial infections, the coagulation system cooperates with the inflammatory system to eliminate the invading pathogens. However, pathogenic bacteria have frequently evolved mechanisms to exploit the hemostatic system components for their own benefit. Streptococcus pyogenes, also known as Group A Streptococcus, provides a remarkable example of the extraordinary capacity of pathogens to exploit the host hemostatic system to support microbial survival and dissemination. The coagulation cascade comprises the contact system (also known as the intrinsic pathway) and the tissue factor pathway (also known as the extrinsic pathway), both leading to fibrin formation. During the early phase of S. pyogenes infection, the activation of the contact system eventually leads to bacterial entrapment within a fibrin clot, where S. pyogenes is immobilized and killed. However, entrapped S. pyogenes can circumvent the antimicrobial effect of the clot by sequestering host plasminogen on the bacterial cell surface that, after conversion into its active proteolytic form, plasmin, degrades the fibrin network and facilitates the liberation of S. pyogenes from the clot. Furthermore, the surface-localized fibrinolytic activity also cleaves a variety of extracellular matrix proteins, thereby enabling S. pyogenes to migrate across barriers and disseminate within the host. This review summarizes the knowledge gained during the last two decades on the role of coagulation/fibrinolysis in host defense against S. pyogenes as well as the strategies developed by this pathogen to evade and exploit these host mechanisms for its own benefit. PMID:25309880

  17. Effects of Fluoride Varnish on Streptococcus mutans Count in Saliva.

    PubMed

    Badjatia, Sourabh; Badjatia, Rini G; Thanveer, K; Krishnan, Ajith Cg

    2017-01-01

    To evaluate the effect of fluoride varnish on Streptococcus mutans count in saliva among 12-year-old school children. A field experiment was conducted to evaluate the effects of fluoride varnish on S. mutans count in saliva among 12-year-old school children. A total of 42 school-going children attending schools in Vadodara district, Gujarat, India, were divided into two groups. Group I was treated with fluoride varnish and group II received no treatment. Assessment of S. mutans was carried out at baseline and 3 to 6 months postfluoride varnish application. Friedman analysis of variance test and post hoc test were applied to detect statistically significant differences between baseline, 3 to 6 months of fluoride varnish application, and also between groups I and II. The mean number of salivary S. mutans value found in case group at baseline, 3 to 6 months was 31.23 ± 1.119, 9.27 ± 0.852, and 9.39 ± 0.908 × 10(4) colony-forming unit CFU/mL respectively. The difference in S. mutans count from baseline to 3 to 6 months was highly statistically significant (p = 0.000), but the difference from 3 to 6 months was not statistically significant (p = 0.142). In control group, the mean S. mutans value found at baseline, 3 to 6 months was 30.63 ± 1.436, 31.23 ± 1.351, and 31.40 ± 1.374 × 10(4) CFU/mL respectively. The differences between these values were not statistically significant (p = 0.11). Statistically significant reduction in S. mutans count in saliva was seen 3 to 6 months after fluoride varnish application. Badjatia S, Badjatia RG, Thanveer K, Krishnan ACG. Effects of Fluoride Varnish on Streptococcus mutans Count in Saliva. Int J Clin Pediatr Dent 2017;10(1):62-66.

  18. Maternal group B Streptococcus-related stillbirth: a systematic review.

    PubMed

    Nan, C; Dangor, Z; Cutland, C L; Edwards, M S; Madhi, S A; Cunnington, M C

    2015-10-01

    Limited epidemiological data on the association between maternal rectovaginal group B Streptococcus (GBS) colonisation and stillbirth makes assessment of antenatal interventions for GBS stillbirth difficult. To systematically review the existing literature and evaluate the incidence of GBS-related stillbirth by region up to March 2015. A systematic review of the published literature was completed using PubMed/MEDLINE, EMBASE, LILACS, and Cochrane Library, with Medical Subject Headings (MeSH) and search terms based upon the Centers for Disease Control and Prevention's (CDC) Active Bacterial Core Surveillance (ABCs) GBS-related stillbirth definition and chorioamnionitis. Studies reporting original data on GBS-related stillbirth occurring ≥20 weeks of gestation, with GBS confirmed by autopsy or by culture from the placenta, amniotic fluid, or other normally sterile site samples from the stillborn. Descriptive analyses were performed with the absolute GBS-related stillbirth rates and proportion of stillbirths attributed to GBS calculated per study where possible. Differences in stillbirth definitions did not allow for pooled estimates to be calculated. Seventeen studies reported GBS-related stillbirth rates varying from 0.04 to 0.9 per 1000 births, with the proportion of stillbirths associated with GBS ranging from 0 to 12.1%. Most studies reported data from before the year 2000 and from high-income countries. The sparsely available epidemiological evidence was not reported consistently, emphasising the importance of standardised stillbirth definitions and diagnostic methods to optimally assess the effectiveness of any future antenatal interventions. Timing of stillbirth, GBS serotype, and global diversity were gaps in the current evidence. Systematic review finds Group B Streptococcus causes up to 12.1% of stillbirths, but more research is needed. © 2015 Royal College of Obstetricians and Gynaecologists.

  19. Differentiation of cultured keratinocytes promotes the adherence of Streptococcus pyogenes.

    PubMed Central

    Darmstadt, G L; Fleckman, P; Jonas, M; Chi, E; Rubens, C E

    1998-01-01

    Based on a consideration of the histopathology of nonbullous impetigo that shows localization of Streptococcus pyogenes to highly differentiated, subcorneal keratinocytes, we hypothesized that adherence of an impetigo strain of S. pyogenes would be promoted by terminal differentiation of keratinocytes. An assay was developed in which S. pyogenes adhered via pilus-like projections from the cell wall to the surface of cultured human keratinocytes in a time- and inoculum-dependent manner suggestive of a receptor-mediated process. Terminal differentiation of keratinocytes was induced by increasing the calcium concentration in the growth medium, and was confirmed by morphologic analysis using electron microscopy. Adherence of S. pyogenes was three and fourfold greater to keratinocytes differentiated in 1.0 and 1.5 mM calcium, respectively, compared with undifferentiated keratinocytes in 0.15 mM calcium. The presence of calcium during the adherence assay further enhanced adherence nearly twofold. Adherence occurred preferentially to sites of contact between adjacent keratinocytes, suggesting that the keratinocyte receptor may be a molecule involved in cell-to-cell adhesion. In contrast, nonpathogenic Streptococcus gordonii adhered poorly to keratinocytes regardless of their state of terminal differentiation, and adherence of a pharyngeal strain of S. pyogenes was twofold greater to undifferentiated than differentiated keratinocytes. This is the first report of in vitro adherence of S. pyogenes to keratinocytes in a manner that emulates human impetigo. Adherence of only the impetigo strain, and not the pharyngeal strain of S. pyogenes or the nonpathogenic S. gorgonii isolate, was promoted by keratinocyte differentiation. This result provides a model system for investigating the molecular pathogenesis of streptococcal skin infections. PMID:9421474

  20. Factors That Cause Trimethoprim Resistance in Streptococcus pyogenes

    PubMed Central

    Bergmann, René; van der Linden, Mark; Chhatwal, Gursharan S.

    2014-01-01

    The use of trimethoprim in treatment of Streptococcus pyogenes infections has long been discouraged because it has been widely believed that this pathogen is resistant to this antibiotic. To gain more insight into the extent and molecular basis of trimethoprim resistance in S. pyogenes, we tested isolates from India and Germany and sought the factors that conferred the resistance. Resistant isolates were identified in tests for trimethoprim or trimethoprim-sulfamethoxazole (SXT) susceptibility. Resistant isolates were screened for the known horizontally transferable trimethoprim-insensitive dihydrofolate reductase (dfr) genes dfrG, dfrF, dfrA, dfrD, and dfrK. The nucleotide sequence of the intrinsic dfr gene was determined for resistant isolates lacking the horizontally transferable genes. Based on tentative criteria, 69 out of 268 isolates (25.7%) from India were resistant to trimethoprim. Occurring in 42 of the 69 resistant isolates (60.9%), dfrF appeared more frequently than dfrG (23 isolates; 33.3%) in India. The dfrF gene was also present in a collection of SXT-resistant isolates from Germany, in which it was the only detected trimethoprim resistance factor. The dfrF gene caused resistance in 4 out of 5 trimethoprim-resistant isolates from the German collection. An amino acid substitution in the intrinsic dihydrofolate reductase known from trimethoprim-resistant Streptococcus pneumoniae conferred resistance to S. pyogenes isolates of emm type 102.2, which lacked other aforementioned dfr genes. Trimethoprim may be more useful in treatment of S. pyogenes infections than previously thought. However, the factors described herein may lead to the rapid development and spread of resistance of S. pyogenes to this antibiotic agent. PMID:24492367

  1. DNA Microarray-Based Typing of Streptococcus agalactiae Isolates

    PubMed Central

    Nitschke, Heike; Slickers, Peter; Müller, Elke; Ehricht, Ralf

    2014-01-01

    Streptococcus agalactiae frequently colonizes the urogenital tract, and it is a major cause of bacterial septicemia, meningitis, and pneumonia in newborns. For typing purposes, a microarray targeting group B streptococcus (GBS) virulence-associated markers and resistance genes was designed and validated with reference strains, as well as clinical and veterinary isolates. Selected isolates were also subjected to multilocus sequence typing. It was observed that putative typing markers, such as alleles of the alpha-like protein or capsule types, vary independently of each other, and they also vary independently from the affiliation to their multilocus sequence typing (MLST)-defined sequence types. Thus, it is not possible to assign isolates to sequence types based on the identification of a single distinct marker, such as a capsule type or alp allele. This suggests the occurrence of frequent genomic recombination. For array-based typing, a set of 11 markers (bac, alp, pil1 locus, pepS8, fbsB, capsule locus, hylB, abiG-I/-II plus Q8DZ34, pil2 locus, nss plus srr plus rogB2, and rgfC/A/D/B) was defined that provides a framework for splitting the tested 448 S. agalactiae isolates into 76 strains that clustered mainly according to MLST-defined clonal complexes. There was evidence for region- and host-specific differences in the population structure of S. agalactiae, as well as an overrepresentation of strains related to sequence type 17 among the invasive isolates. The arrays and typing scheme described here proved to be a convenient tool for genotyping large numbers of clinical/veterinary isolates and thus might help obtain insight into the epidemiology of S. agalactiae. PMID:25165085

  2. Redundant group a streptococcus signaling peptides exhibit unique activation potentials.

    PubMed

    LaSarre, Breah; Chang, Jennifer C; Federle, Michael J

    2013-09-01

    All bacterial quorum sensing (QS) systems are based on the production, secretion, and detection of small signaling molecules. Gram-positive bacteria typically use small peptides as QS effectors, and each QS circuit generally requires the interaction of a single signaling molecule with a single receptor protein. The recently described Rgg2 and Rgg3 (Rgg2/3) regulatory circuit of Streptococcus pyogenes (group A streptococcus [GAS]) is one of only a few QS circuits known to utilize multiple signaling peptides. In this system, two distinct, endogenously produced peptide pheromones (SHP2 and SHP3) both function to activate the QS circuit. The aim of this study was to further define the roles of SHP2 and SHP3 in activation of the Rgg2/3 QS system, specifically with regard to shp gene identity and dosage. Results from our studies using transcriptional reporters and isogenic GAS mutants demonstrate that shp gene dosage does contribute to Rgg2/3 system induction, as decreased gene dosage results in decreased or absent induction. Beyond this, however, data indicate that the shp genes possess distinct potentials for supporting system activation, with shp3 more readily able to support system activation than shp2. Studies using synthetic peptides and shp gene mutants indicate that the disparate activities of endogenous SHPs are due to production, rather than signaling, differences and are conferred by the N-terminal regions rather than the C-terminal signaling regions of the peptides. These data provide evidence that the N-terminal, noneffector sequences of SHP pheromones influence their production efficiencies and thereby the relative activation potentials of endogenous SHPs.

  3. Comparative molecular analysis of ovine and bovine Streptococcus uberis isolates.

    PubMed

    Gilchrist, T L; Smith, D G E; Fitzpatrick, J L; Zadoks, R N; Fontaine, M C

    2013-02-01

    Streptococcus uberis causes clinical and subclinical mastitis in cattle and sheep, but it is unknown whether the composition of Strep. uberis populations differs between host species. To address this, we characterized a collection of bovine and ovine Strep. uberis isolates with shared geographical and temporal origins by means of an expanded multilocus sequence typing scheme. Among 14 ovine and 35 bovine isolates, 35 allelic profiles were detected. Each allelic profile was associated with a single host species and all but one were new to the multilocus sequence typing database. The median number of new alleles per isolate was higher for ovine isolates than for bovine isolates. None of the ovine isolates belonged to the global clonal complexes 5 or 143, which are commonly associated with bovine mastitis and which have a wide geographical distribution. Ovine isolates also differed from bovine isolates in carriage of plasminogen activator genes, with significantly higher prevalence of pauB in ovine isolates. Isolates that were negative for yqiL, one of the targets of multilocus sequence typing, were found among ovine and bovine isolates and were not associated with a specific sequence type or global clonal complex. One bovine isolate carried a gapC allele that was probably acquired through lateral gene transfer, most likely from Streptococcus salivarius. We conclude that ovine isolates are distinct from bovine isolates of Strep. uberis, and that recombination between isolates from different host species or bacterial species could contribute to changes in virulence gene profiles with relevance for vaccine development. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. Streptococcus pneumoniae and Pseudomonas aeruginosa pneumonia induce distinct host responses.

    PubMed

    McConnell, Kevin W; McDunn, Jonathan E; Clark, Andrew T; Dunne, W Michael; Dixon, David J; Turnbull, Isaiah R; Dipasco, Peter J; Osberghaus, William F; Sherman, Benjamin; Martin, James R; Walter, Michael J; Cobb, J Perren; Buchman, Timothy G; Hotchkiss, Richard S; Coopersmith, Craig M

    2010-01-01

    Pathogens that cause pneumonia may be treated in a targeted fashion by antibiotics, but if this therapy fails, then treatment involves only nonspecific supportive measures, independent of the inciting infection. The purpose of this study was to determine whether host response is similar after disparate infections with similar mortalities. Prospective, randomized controlled study. Animal laboratory in a university medical center. Pneumonia was induced in FVB/N mice by either Streptococcus pneumoniae or two different concentrations of Pseudomonas aeruginosa. Plasma and bronchoalveolar lavage fluid from septic animals was assayed by a microarray immunoassay measuring 18 inflammatory mediators at multiple time points. The host response was dependent on the causative organism as well as kinetics of mortality, but the pro-inflammatory and anti-inflammatory responses were independent of inoculum concentration or degree of bacteremia. Pneumonia caused by different concentrations of the same bacteria, Pseudomonas aeruginosa, also yielded distinct inflammatory responses; however, inflammatory mediator expression did not directly track the severity of infection. For all infections, the host response was compartmentalized, with markedly different concentrations of inflammatory mediators in the systemic circulation and the lungs. Hierarchical clustering analysis resulted in the identification of five distinct clusters of the host response to bacterial infection. Principal components analysis correlated pulmonary macrophage inflammatory peptide-2 and interleukin-10 with progression of infection, whereas elevated plasma tumor necrosis factor sr2 and macrophage chemotactic peptide-1 were indicative of fulminant disease with >90% mortality within 48 hrs. Septic mice have distinct local and systemic responses to Streptococcus pneumoniae and Pseudomonas aeruginosa pneumonia. Targeting specific host inflammatory responses induced by distinct bacterial infections could represent a

  5. Bacterial adhesion of Streptococcus mutans to provisional fixed prosthodontic material.

    PubMed

    Buergers, Ralf; Rosentritt, Martin; Handel, Gerhard

    2007-12-01

    Bacterial adhesion and formation of dental plaque on provisional fixed prosthodontic materials results in gingival inflammation and secondary caries. The purpose of this in vitro study was to compare 10 commonly used provisional fixed prosthodontic materials (2 acrylic polymethyl methacrylates, 2 improved methacrylates, and 6 bisacrylate composite resins), based on their susceptibility to adhere to Streptococcus mutans, and examine the influence of surface roughness and hydrophobicity. Surface roughness was assessed by perthometer and hydrophobicity by contact angle measurements. Streptococcus mutans suspension was incubated with 15 disk-shaped specimens for each material (10 x 2 mm) and examined with the fluorescence dye, Alamar Blue/resazurin, and an automated multidetection reader. Glass and the veneering composite resin, Sinfony, served as controls. Statistical analysis was performed using the Mann-Whitney U-test in combination with the Bonferroni adjustment. Additionally, scanning electron micrographs were made. Median surface roughness values ranged between 0.04 microm and 0.08 microm, and median contact angles between 46.5 and 71 degrees. High relative fluorescence intensities (>10,000) were found for Snap, UniFast LC, and CronMix K plus, moderate values (5000-10,000) for Trim, Temphase, Structur Premium, and PreVISION CB, and lowest fluorescence intensities (<5000) were found for Cronsin, Protemp 3 Garant, and Luxatemp. Scanning electron micrographs displayed streptococcal monolayers on all investigated surfaces, indicating initial bacterial adhesion. The quantity of bacterial adhesion differed significantly among the assessed provisional materials. A correlation between bacterial adhesion and surface roughness or hydrophobicity was not confirmed. Bisacrylate composite resins and acrylic polymethyl methacrylates had significantly lower adhesion potentials than improved methacrylates.

  6. Identification of β-haemolysin-encoding genes in Streptococcus anginosus.

    PubMed

    Asam, D; Mauerer, S; Walheim, E; Spellerberg, B

    2013-08-01

    Streptococcus anginosus is an emerging pathogen, but little is known about its virulence factors. To detect the genes responsible for β-haemolysis we performed genomic mutagenesis of the β-haemolytic S. anginosus type strain ATCC 12395 using the vector pGhost9:ISS1. Integration site analysis of 15 non-haemolytic mutants identified a gene cluster with high homology to the genes of the streptolysin S (SLS) encoding sag gene cluster of S. pyogenes. The gene cluster harbours 10 open reading frames displaying significant similarities to the S. pyogenes genes sagA-sagI, with the identities on protein level ranging from 38 to 87%. Complementation assays of S. anginosus sagB and sagD integration mutants with the respective genes confirmed their importance for β-haemolysin production and suggest the presence of post-translational modifications in S. anginosus SLS similar to SLS of S. pyogenes. Characterization of the S. anginosus haemolysin in comparison to the S. pyogenes SLS showed that the haemolysin is surface bound, but in contrast to S. pyogenes neither fetal calf serum nor RNA was able to stabilize the haemolysin of S. anginosus in culture supernatants. Inhibition of β-haemolysis by polyethylene glycol of different sizes was carried out, giving no evidence of a pore-forming haemolytic mechanism. Analysis of a whole genome shotgun sequence of Streptococcus constellatus, a closely related streptococcal species that belongs to the S. anginosus group, revealed a similar sag gene cluster. Employing a genomic mutagenesis strategy we were able to determine an SLS encoding gene cluster in S. anginosus and demonstrate its importance for β-haemolysin production in S. anginosus.

  7. Effect of a chlorhexidine varnish on Streptococcus mutans in saliva.

    PubMed

    Piovano, Susana; Marcantoni, Mabel; Doño, Raquel; Bellagamba, Hebe

    2005-01-01

    The aim of the present work was to evaluate the effect of a thymol/chlorhexidine varnish at 1% on Streptococcus mutans (S. mutans) in saliva applied after teaching and evaluating an oral hygiene technique and dressing the cavities to reduce the bacterial load. Streptococcus mutans levels in saliva samples and dental status were evaluated in 38 girls between 6 and 13 years of age with high risk of caries. The girls were then trained and assessed in oral hygiene. On day seven, oral hygiene assessment was repeated and supragingival plaque control was performed. After 15 days (day 21) another culture was performed and the level of S. mutans in saliva samples was determined. Evaluation and reinforcement of the oral hygiene technique were repeated and the cavities were dressed to reduce the bacterial load. At 36 days from the onset of the experiment, culture S. mutans counts were performed; evaluation and reinforcement of the oral hygiene technique were undertaken and the girls were divided randomly into two groups: 1 The teeth of the experimental group were painted with a varnish containing 1% chlorhexidine and thymol. 2 The teeth of the control group were painted with a placebo varnish containing only thymol. After a further 15 days (day 51), another culture and S. mutans counts were performed. The results showed a gradual reduction in the S. mutans counts in saliva in each subsequent experimental period analyzed. Significant differences between the experimental group and the control group were recorded after treatment. It can be concluded that the levels of S. mutans decreased in each subsequent experimental period and that the application of a 1% chlorhexidine varnish elicited a significant reduction in S. mutans levels.

  8. vanG Element Insertions within a Conserved Chromosomal Site Conferring Vancomycin Resistance to Streptococcus agalactiae and Streptococcus anginosus

    PubMed Central

    Srinivasan, Velusamy; Metcalf, Benjamin J.; Knipe, Kristen M.; Ouattara, Mahamoudou; McGee, Lesley; Shewmaker, Patricia L.; Glennen, Anita; Nichols, Megin; Harris, Carol; Brimmage, Mary; Ostrowsky, Belinda; Park, Connie J.; Schrag, Stephanie J.; Frace, Michael A.; Sammons, Scott A.

    2014-01-01

    ABSTRACT Three vancomycin-resistant streptococcal strains carrying vanG elements (two invasive Streptococcus agalactiae isolates [GBS-NY and GBS-NM, both serotype II and multilocus sequence type 22] and one Streptococcus anginosus [Sa]) were examined. The 45,585-bp elements found within Sa and GBS-NY were nearly identical (together designated vanG-1) and shared near-identity over an ~15-kb overlap with a previously described vanG element from Enterococcus faecalis. Unexpectedly, vanG-1 shared much less homology with the 49,321-bp vanG-2 element from GBS-NM, with widely different levels (50% to 99%) of sequence identity shared among 44 related open reading frames. Immediately adjacent to both vanG-1 and vanG-2 were 44,670-bp and 44,680-bp integrative conjugative element (ICE)-like sequences, designated ICE-r, that were nearly identical in the two group B streptococcal (GBS) strains. The dual vanG and ICE-r elements from both GBS strains were inserted at the same position, between bases 1328 and 1329, within the identical RNA methyltransferase (rumA) genes. A GenBank search revealed that although most GBS strains contained insertions within this specific site, only sequence type 22 (ST22) GBS strains contained highly related ICE-r derivatives. The vanG-1 element in Sa was also inserted within this position corresponding to its rumA homolog adjacent to an ICE-r derivative. vanG-1 insertions were previously reported within the same relative position in the E. faecalis rumA homolog. An ICE-r sequence perfectly conserved with respect to its counterpart in GBS-NY was apparent within the same site of the rumA homolog of a Streptococcus dysgalactiae subsp. equisimilis strain. Additionally, homologous vanG-like elements within the conserved rumA target site were evident in Roseburia intestinalis. PMID:25053786

  9. Phenotypic characterisation and 16S rRNA sequence analysis of veterinary isolates of Streptococcus pluranimalium.

    PubMed

    Twomey, D F; Carson, T; Foster, G; Koylass, M S; Whatmore, A M

    2012-05-01

    Forty-two isolates of Streptococcus pluranimalium were identified from cattle (n=38), sheep (n=2), an alpaca (n=1) and a pheasant (n=1) in the United Kingdom. The isolates were confirmed as S. pluranimalium by 16S rRNA sequence analysis but could not be differentiated reliably from Streptococcus acidominimus by phenotypic characterisation using commercial kits routinely used in veterinary laboratories. The alanyl-phenylalanyl-proline arylamidase reaction could be used to differentiate S. pluranimalium (positive) from Aerococcus urinae (negative).

  10. Streptococcus himalayensis sp. nov., isolated from the respiratory tract of Marmota himalayana.

    PubMed

    Niu, Lina; Lu, Shan; Lai, Xin-He; Hu, Shoukui; Chen, Cuixia; Zhang, Gui; Yang, Jing; Jin, Dong; Wang, Yi; Lan, Ruiting; Lu, Gang; Xie, Yingping; Ye, Changyun; Xu, Jianguo

    2017-02-01

    Five strains of Gram-positive-staining, catalase-negative, coccus-shaped, chain-forming organisms isolated separately from the respiratory tracts of five Marmota himalayana animals in the Qinghai-Tibet Plateau of China were subjected to phenotypic and molecular taxonomic analyses. Comparative analysis of the 16S rRNA gene indicated that these singular organisms represent a new member of the genus Streptococcus, being phylogenetically closest to Streptococcus marmotae DSM 101995T (98.4 % similarity). The groEL, sodA and rpoB sequence analysis showed interspecies similarity values between HTS2T and Streptococcus. marmotae DSM 101995T, its closest phylogenetic relative based on 16S rRNA gene sequences, of 98.2, 78.8 and 93.7 %, respectively. A whole-genome phylogenetic tree built from 82 core genes of genomes from 16 species of the genus Streptococcus validated that HTS2T forms a distinct subline and exhibits specific phylogenetic affinity with S. marmotae. In silico DNA-DNA hybridization of HTS2T showed an estimated DNA reassociation value of 40.5 % with Streptococcus. marmotae DSM 101995T. On the basis of their phenotypic characteristics and phylogenetic findings, it is proposed that the five isolates be classified as representatives of a novel species of the genus Streptococcus, Streptococcus himalayensis sp. nov. The type strain is HTS2T (=DSM 101997T=CGMCC 1.15533T). The genome of Streptococcus himalayensis sp. nov. strain HTS2T contains 2195 genes with a size of 2 275 471 bp and a mean DNA G+C content of 41.3 mol%.

  11. Intracerebral hemorrhage and deep microbleeds associated with cnm-positive Streptococcus mutans; a hospital cohort study.

    PubMed

    Tonomura, Shuichi; Ihara, Masafumi; Kawano, Tomohiro; Tanaka, Tomotaka; Okuno, Yoshinori; Saito, Satoshi; Friedland, Robert P; Kuriyama, Nagato; Nomura, Ryota; Watanabe, Yoshiyuki; Nakano, Kazuhiko; Toyoda, Kazunori; Nagatsuka, Kazuyuki

    2016-02-05

    Oral infectious diseases are epidemiologically associated with stroke. We previously showed that oral Streptococcus mutans with the cnm gene encoding a collagen-binding Cnm protein induced intracerebral hemorrhage (ICH) experimentally and was also associated with cerebral microbleeds (CMBs) in our population-based cohort study. We therefore investigated the roles of cnm-positive Streptococcus mutans in this single hospital-based, observational study that enrolled 100 acute stroke subjects. The cnm gene in Streptococcus mutans isolated from saliva was screened using PCR techniques and its collagen-binding activities examined. CMBs were evaluated on T2* gradient-recalled echo MRI. One subject withdrew informed consent and 99 subjects (63 males) were analyzed, consisting of 67 subjects with ischemic stroke, 5 with transient ischemic attack, and 27 with ICH. Eleven cases showed Streptococcus mutans strains positive for cnm. The presence of cnm-positive Streptococcus mutans was significantly associated with ICH [OR vs. ischemic stroke, 4.5; 95% CI, 1.17-19.1] and increased number of deep CMBs [median (IQR), 3 (2-9) vs. 0 (0-1), p = 0.0002]. In subjects positive for Streptococcus mutans, collagen binding activity was positively correlated with the number of deep CMBs (R(2) = 0.405; p < 0.0001). These results provide further evidence for the key role of oral health in stroke.

  12. Intracerebral hemorrhage and deep microbleeds associated with cnm-positive Streptococcus mutans; a hospital cohort study

    PubMed Central

    Tonomura, Shuichi; Ihara, Masafumi; Kawano, Tomohiro; Tanaka, Tomotaka; Okuno, Yoshinori; Saito, Satoshi; Friedland, Robert P.; Kuriyama, Nagato; Nomura, Ryota; Watanabe, Yoshiyuki; Nakano, Kazuhiko; Toyoda, Kazunori; Nagatsuka, Kazuyuki

    2016-01-01

    Oral infectious diseases are epidemiologically associated with stroke. We previously showed that oral Streptococcus mutans with the cnm gene encoding a collagen-binding Cnm protein induced intracerebral hemorrhage (ICH) experimentally and was also associated with cerebral microbleeds (CMBs) in our population-based cohort study. We therefore investigated the roles of cnm-positive Streptococcus mutans in this single hospital-based, observational study that enrolled 100 acute stroke subjects. The cnm gene in Streptococcus mutans isolated from saliva was screened using PCR techniques and its collagen-binding activities examined. CMBs were evaluated on T2* gradient-recalled echo MRI. One subject withdrew informed consent and 99 subjects (63 males) were analyzed, consisting of 67 subjects with ischemic stroke, 5 with transient ischemic attack, and 27 with ICH. Eleven cases showed Streptococcus mutans strains positive for cnm. The presence of cnm-positive Streptococcus mutans was significantly associated with ICH [OR vs. ischemic stroke, 4.5; 95% CI, 1.17–19.1] and increased number of deep CMBs [median (IQR), 3 (2–9) vs. 0 (0–1), p = 0.0002]. In subjects positive for Streptococcus mutans, collagen binding activity was positively correlated with the number of deep CMBs (R2 = 0.405; p < 0.0001). These results provide further evidence for the key role of oral health in stroke. PMID:26847666

  13. [Experimental study of the inhibitory effects of Chelidonium majus L. extractive on Streptococcus mutans in vitro].

    PubMed

    Cheng, Rui-bo; Chen, Xu; Liu, Shu-jie; Zhang, Xiao-fang; Zhang, Guang-he

    2006-06-01

    To study the inhibitory effects of Chelidonium majus L. extractive on the growth of Streptococcus mutans in vitro, and to explore its mechanism in caries prevention. Streptococcus mutans 25175 was chosen as the experimental bacterium. The Chelidonium majus L. extractives chelidonine and chelerythrine were double diluted to different concentrations by two-fold dilution. The inhibitory effect of Streptococcus mutans was measured by slip diffusion method. The minimal inhibitory concentration(MIC) was also determined. 0.16% liquor hibitane was used as positive control. Spearman correlation was used for statistical analysis. Inhibition zone of Streptococcus mutans appeared in some concentration of chelerythrine, but no inhibition zone in each concentration of chelidonine. The MIC of chelerythrine was 0.78 mg/ml which determined by liquid culture medium. The concentration of chelerythrine was highly related to the inhibitory zone of Streptococcus mutans (r=0.99, P<0.01). The antibacterial activity of Chelidonium majus L. extractive chelerythrine on Streptococcus mutans was significant,and the antibacterial activity of the concentration 100 mg/ml was higher than that of 0.16% liquor hibitane (19.4 mm), indicating that chelerythrine can be used as an agent for prevention of dental caries.

  14. Streptococcus constellatus Causing Septic Thrombophlebitis of the Right Ovarian Vein with Extension into the Inferior Vena Cava

    PubMed Central

    Haidar, Abdallah; Haddad, Amy; Naqvi, Amir; Onyesoh, Ngozi U.; Malik, Rushdah; Williams, Michael

    2015-01-01

    Introduction. Streptococcus constellatus collectively with Streptococcus anginosus and Streptococcus intermedius constitute the Streptococcus anginosus (formerly Streptococcus milleri) group. Though they are commonly associated with abscesses, bacteremia with subsequent septic thrombophlebitis is extremely rare, and resulting mortality is infrequent. Case Presentation. We report a case of a previously healthy 60-year-old African American female who presented with Streptococcus constellatus bacteremia associated with septic thrombophlebitis to the right ovarian vein extending into the inferior vena cava. She was urgently treated with antibiotics and anticoagulation. Conclusion. Septic thrombophlebitis has a clinical presentation that is often misleading. Therefore, a high clinical index of suspicion and the use of appropriate imaging modalities (computed tomography) are essential in recognizing and confirming this diagnosis. Prompt treatment is warranted. Surgical thrombectomies have been successfully replaced by a combination of antibiotics and anticoagulation therapy. PMID:26171262

  15. Streptococcus constellatus Causing Septic Thrombophlebitis of the Right Ovarian Vein with Extension into the Inferior Vena Cava.

    PubMed

    Haidar, Abdallah; Haddad, Amy; Naqvi, Amir; Onyesoh, Ngozi U; Malik, Rushdah; Williams, Michael

    2015-01-01

    Introduction. Streptococcus constellatus collectively with Streptococcus anginosus and Streptococcus intermedius constitute the Streptococcus anginosus (formerly Streptococcus milleri) group. Though they are commonly associated with abscesses, bacteremia with subsequent septic thrombophlebitis is extremely rare, and resulting mortality is infrequent. Case Presentation. We report a case of a previously healthy 60-year-old African American female who presented with Streptococcus constellatus bacteremia associated with septic thrombophlebitis to the right ovarian vein extending into the inferior vena cava. She was urgently treated with antibiotics and anticoagulation. Conclusion. Septic thrombophlebitis has a clinical presentation that is often misleading. Therefore, a high clinical index of suspicion and the use of appropriate imaging modalities (computed tomography) are essential in recognizing and confirming this diagnosis. Prompt treatment is warranted. Surgical thrombectomies have been successfully replaced by a combination of antibiotics and anticoagulation therapy.

  16. Influence of fluoride on the bacterial composition of a dual-species biofilm composed of Streptococcus mutans and Streptococcus oralis.

    PubMed

    Jung, Ji-Eun; Cai, Jian-Na; Cho, Sung-Dae; Song, Kwang-Yeob; Jeon, Jae-Gyu

    2016-10-01

    Despite the widespread use of fluoride for the prevention of dental caries, few studies have demonstrated the effects of fluoride on the bacterial composition of dental biofilms. This study investigated whether fluoride affects the proportion of Streptococcus mutans and S. oralis in mono- and dual-species biofilm models, via microbiological, biochemical, and confocal fluorescence microscope studies. Fluoride did not affect the bacterial count and bio-volume of S. mutans and S. oralis in mono-species biofilms, except for the 24-h-old S. mutans biofilms. However, fluoride reduced the proportion and bio-volume of S. mutans but did not decrease those of S. oralis during both S. oralis and S. mutans dual-species biofilm formation, which may be related to the decrease in extracellular polysaccharide formation by fluoride. These results suggest that fluoride may prevent the shift in the microbial proportion to cariogenic bacteria in dental biofilms, subsequently inhibiting the cariogenic bacteria dominant biofilm formation.

  17. Spontaneous meningitis due to Streptococcus salivarius subsp. salivarius: cross-reaction in an assay with a rapid diagnostic kit that detected Streptococcus pneumoniae antigens.

    PubMed

    Shirokawa, Taijiro; Nakajima, Jun; Hirose, Kazuhito; Suzuki, Hiromichi; Nagaoka, Shoko; Suzuki, Masatsune

    2014-01-01

    Streptococcus salivarius subsp. salivarius occasionally causes meningitis associated with iatrogenic or traumatic events. We herein describe a case of meningitis caused by this organism in a patient without any apparent risk factors. In an assay of the patient's cerebrospinal fluid, cross-reaction occurred with Streptococcus pneumoniae antigen-coated latex particles in the Pastorex Meningitis Kit. In the in vitro assays, three of the five clinically isolated S. salivarius strains showed cross-reactions with the kit, indicating that these strains expressed pneumococcal antigen-like antigens. This case shows that meningitis caused by S. salivarius can occur spontaneously and it may sometimes be misdiagnosed as S. pneumoniae infection.

  18. Differentiation between Streptococcus gallolyticus Strains of Human Clinical and Veterinary Origins and Streptococcus bovis Strains from the Intestinal Tracts of Ruminants

    PubMed Central

    Devriese, Luc A.; Vandamme, Peter; Pot, Bruno; Vanrobaeys, Mia; Kersters, Karel; Haesebrouck, Freddy

    1998-01-01

    Strains formerly identified as Streptococcus bovis were allotted to two groups by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of whole-cell proteins. Strains from humans with infections, mostly patients with endocarditis, and strains from pigeons with septicemia clustered with the recently described species Streptococcus gallolyticus. The original S. bovis type strain and strains exclusively from ruminants formed the second cluster. The findings indicate that S. gallolyticus is more likely to be involved in human and animal infections than S. bovis. Growth characteristics and several biochemical reactions were found to be useful in the differentiation of S. gallolyticus from S. bovis. PMID:9817865

  19. Novel real-time PCR assays using TaqMan minor groove binder probes for identification of fecal carriage of Streptococcus bovis/Streptococcus equinus complex from rectal swab specimens.

    PubMed

    Lopes, Paulo Guilherme Markus; Cantarelli, Vlademir Vicente; Agnes, Grasiela; Costabeber, Ane Micheli; d'Azevedo, Pedro Alves

    2014-03-01

    Real-time PCR based on the recN and gyrB genes was developed to detect four Streptococcus bovis/Streptococcus equinus complex (SBEC) subspecies from rectal swab specimens. The overall prevalence was 35.2%: Streptococcus gallolyticus subsp. gallolyticus (11.1%), S. gallolyticus subsp. pasteurianus (13%), Streptococcus infantarius subsp. coli (20.4%), and S. infantarius subsp. infantarius (11.1%). To conclude, these real-time PCR assays provide a reliable molecular method to detect SBEC pathogenic subspecies from rectal swab specimens.

  20. Inhibiting effects of Streptococcus salivarius on competence-stimulating peptide-dependent biofilm formation by Streptococcus mutans.

    PubMed

    Tamura, S; Yonezawa, H; Motegi, M; Nakao, R; Yoneda, S; Watanabe, H; Yamazaki, T; Senpuku, H

    2009-04-01

    The effects of Streptococcus salivarius on the competence-stimulating peptide (CSP)-dependent biofilm formation by Streptococcus mutans were investigated. Biofilms were grown on 96-well microtiter plates coated with salivary components in tryptic soy broth without dextrose supplemented with 0.25% sucrose. Biofilm formations were stained using safranin and quantification of stained biofilms was performed by measuring absorbance at 492 nm. S. mutans formed substantial biofilms, whereas biofilms of S. salivarius were formed poorly in the medium conditions used. Furthermore, in combination cultures, S. salivarius strongly inhibited biofilm formation when cultured with S. mutans. This inhibition occurred in the early phase of biofilm formation and was dependent on inactivation of the CSP of S. mutans, which is associated with competence, biofilm formation, and antimicrobial activity of the bacterium, and is induced by expression of the comC gene. Comparisons between the S. mutans clinical strains FSC-3 and FSC-3DeltaglrA in separate dual-species cultures with S. salivarius indicated that the presence of the bacitracin transport ATP-binding protein gene glrA caused susceptibility to inhibition of S. mutans biofilm formation by S. salivarius, and was also associated with the regulation of CSP production by com gene-dependent quorum sensing systems. It is considered that regulation of CSP by glrA in S. mutans and CSP inactivation by S. salivarius are important functions for cell-to-cell communication between biofilm bacteria and oral streptococci such as S. salivarius. Our results provide useful information for understanding the ecosystem of oral streptococcal biofilms, as well as the competition between and coexistence of multiple species in the oral cavity.

  1. Antibacterial activity of clove, gall nut methanolic and ethanolic extracts on Streptococcus mutans PTCC 1683 and Streptococcus salivarius PTCC 1448.

    PubMed

    Mirpour, Mirsasan; Gholizadeh Siahmazgi, Zohreh; Sharifi Kiasaraie, Masoumeh

    2015-01-01

    Antimicrobial compounds from herbal sources have good therapeutic potential. In this study, the antibacterial effects of clove and gall nut, methanolic and ethanolic extractions, were evaluated for their effect on Streptococcus mutans PTCC 1683 and Streptococcus salivarius PTCC 1448, as both the two cause oral diseases. The clove and gall nut methanolic and ethanolic extracts were prepared and antibacterial activity was evaluated for S. mutans and S. salivarius in the base of inhibition zone diameter using agar diffusion method. In this part minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were assessed. These extracts showed effective antibacterial activity on bacteria. Antibacterial activity of Methanolic extract of clove was more than that of ethanolic extract, and ethanolic extracts of gall nut had antibacterial activity more than that of methanolic extracts. MIC and MBC results for clove methanolic extract were 1.5 mg/ml and 3 mg/ml for S. mutans and 6.25 mg/ml and 12.5 mg/ml for S. salivarius, respectively. These results for clove ethanolic extracts were 12.5 mg/ml and 25 mg/ml for S. mutans and 25 mg/ml and 50 mg/ml for S. salivarius, respectively. MIC and MBC results for gall nut methanolic extract were 25 mg/ml and 50 mg/ml for S. mutans and 12.5 mg/ml and 25 mg/ml for S. salivarius, respectively. These results for gall nut ethanolic extracts were 3.1 mg/ml and 6.2 mg/ml for S. mutans and 25 mg/ml and 50 mg/ml for S. salivarius, respectively. The results showed effective antibacterial activity using clove and gall nut methanolic extracts. If other properties such as tolerance of tissue can also be studied, these extracts can be used as a mouthwash.

  2. Clinical characteristics and significance of Streptococcus salivarius bacteremia and Streptococcus bovis bacteremia: a prospective 16-year study.

    PubMed

    Corredoira, J C; Alonso, M P; García, J F; Casariego, E; Coira, A; Rodriguez, A; Pita, J; Louzao, C; Pombo, B; López, M J; Varela, J

    2005-04-01

    The aim of this study was to determine the clinical significance of Streptococcus salivarius isolates recovered from blood cultures and compare them with isolates of Streptococcus bovis biotypes I and II. Seventeen of the 52 (32%) S. salivarius isolates recovered were considered clinically significant, compared with 62 of the 64 (97%) S. bovis isolates (p<0.0001). Bacteremia caused by S. salivarius occurred mostly in patients who showed relevant disruption of the mucous membranes and/or serious underlying diseases. Patients with S. salivarius bacteremia were younger than those with S. bovis bacteremia (57 vs. 67 years; p<0.01). Patients with S. salivarius bacteremia and patients with S. bovis II bacteremia had similar rates of endocarditis, colon tumors, and non-colon cancer. On the other hand, when compared with S. bovis I bacteremia, S. salivarius bacteremia was associated with lower rates of endocarditis (18% vs. 74%, respectively) (p<0.01) and colon tumors (0% vs. 57%, respectively) (p<0.005) and higher rates of non-colon cancer (53% vs. 9.5%, respectively) (p<0.01). Bacteremia caused by S. bovis II had a hepatobiliary origin in 50% of the patients, while, in contrast, that due to S. salivarius or S. bovis I was less frequently associated with a hepatobiliary origin (12% and 5%, respectively) (p<0.00001). The rate of penicillin resistance was 31% among S. salivarius isolates and 0% among S. bovis isolates (p<0.0001). In conclusion, the clinical characteristics of S. salivarius bacteremia and S. bovis II bacteremia are similar, and the isolation of S. salivarius in blood should not be systematically regarded as contamination.

  3. Influence of time, toothpaste and saliva in the retention of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes

    PubMed Central

    SCHMIDT, Julia Caroline; BUX, Miriam; FILIPUZZI-JENNY, Elisabeth; KULIK, Eva Maria; WALTIMO, Tuomas; WEIGER, Roland; WALTER, Clemens

    2014-01-01

    Objectives The intraoral transmission of cariogenic and periodontopathogenic species seems to be facilitated by contaminated toothbrushes and other oral hygiene devices. The aim of this investigation was to analyze the in vitro retention and survival rate of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes. The impacts of human saliva and antimicrobial toothpaste on these parameters were further evaluated. Material and Methods Part I: Four toothbrushes (Colgate 360°, Curaprox CS5460 ultra soft, elmex InterX, Trisa Flexible Head3) were contaminated by S. mutans DSM 20523 or S. sanguinis DSM 20068 suspensions for three minutes. Bacteria were removed from the toothbrushes after either three minutes (T0) or 24 hours (T24) of dry storage and grown on Columbia blood agar plates for the quantification of colony-forming units (CFUs). Part II: The effects of saliva from a caries-active or a caries-inactive person and of toothpaste containing 0.12% chlorhexidine digluconate were also tested. Results Part I: After three minutes of dry storage, approximately one percent of the bacteria were still detectable on the toothbrushes. After 24 hours, S. sanguinis exhibited a more pronounced decrease in viable cell numbers compared with S. mutans but the differences were not significant (Kruskal-Wallis test, p>0.05). Part II: The addition of human saliva from a caries-active or caries-inactive person slightly increased the retention of both streptococcal species at T0. The use of toothpaste had no influence on the amount of viable streptococci at T0, but it reduced the microbial load after 24 hours of storage. There were only slight nonsignificant differences (p>0.05) between the four toothbrushes. Conclusions In vitro bacterial retention and survival of S. sanguinis and S. mutans on different toothbrushes occurred. Within the limitations of this study, the use of human saliva or an antimicrobial toothpaste did not lead to significant differences in the

  4. Chemical and botanical characterization of Chilean propolis and biological activity on cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus.

    PubMed

    Barrientos, Leticia; Herrera, Christian L; Montenegro, Gloria; Ortega, Ximena; Veloz, Jorge; Alvear, Marysol; Cuevas, Alejandro; Saavedra, Nicolás; Salazar, Luis A

    2013-01-01

    Propolis is a non-toxic natural substance with multiple pharmacological properties including anti-cancer, antioxidant, fungicidal, antibacterial, antiviral, and anti-inflammatory among others. The aim of this study was to determine the chemical and botanical characterization of Chilean propolis samples and to evaluate their biological activity against the cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus. Twenty propolis samples were obtained from beekeeping producers from the central and southern regions of Chile. The botanical profile was determined by palynological analysis. Total phenolic contents were determined using colorimetric assays. Reverse phase HPLC and HPLC-MS were used to determine the chemical composition. The minimum inhibitory concentration (MIC) was determined on S. mutans and S. sobrinus. All propolis samples were dominated by structures from native plant species. The characterization by HPLC/MS, evidenced the presence of quercetin, myricetin, kaempferol, rutine, pinocembrin, coumaric acid, caffeic acid and caffeic acid phenethyl ester, that have already been described in these propolis with conventional HPLC. Although all propolis samples inhibited the mutans streptococci growth, it was observed a wide spectrum of action (MIC 0.90 to 8.22 μg mL(-1)). Given that results it becomes increasingly evident the need of standardization procedures, where we combine both the determination of botanical and the chemical characterization of the extracts. Research conducted to date, describes a promising effectiveness of propolis in the prevention of caries and other diseases of the oral cavity, making it necessary to develop studies to identify and understand the therapeutic targets or mechanisms of molecular action of the various compounds present on them.

  5. Divalent cations enhance fluoride binding to Streptococcus mutans and Streptococcus sanguinis cells and subsequently inhibit bacterial acid production.

    PubMed

    Domon-Tawaraya, H; Nakajo, K; Washio, J; Ashizawa, T; Ichino, T; Sugawara, H; Fukumoto, S; Takahashi, N

    2013-01-01

    One preventive effect of topical fluoride application is derived from the fact that fluoride can inhibit bacterial acid production. Furthermore, divalent cations such as Ca(2+) and Mg(2+) increase the binding of fluoride to bacterial cells. These findings suggest that exposure of oral bacteria to fluoride in the presence of divalent cations increases fluoride binding to bacterial cells and subsequently enhances fluoride-induced inhibition of bacterial acid production. This study investigated the effects of fluoride exposure (0-20,000 ppm F) in the presence of Ca(2+) or Mg(2+) prior to glucose challenge on pH fall ability by bacterial sugar fermentation, as well as fluoride binding to bacterial cells by exposure to fluoride, and fluoride release from bacterial cells during bacterial sugar fermentation, using caries-related bacteria, Streptococcus mutans and Streptococcus sanguinis. The pH fall by both streptococci was inhibited by exposure to over 250 ppm F in the presence of Ca(2+) (p < 0.01), whereas in the presence of Mg(2+), the pH fall by S. mutans and S. sanguinis was inhibited after exposure to over 250 and 950 ppm F, respectively (p < 0.05). The amounts of fluoride binding to and released from streptococcal cells increased with the concentration of fluoride the cells were exposed to in the presence of Mg(2+), but were high enough even after 250 ppm F exposure in the presence of Ca(2+). The enhanced inhibition of acid production in the presence of divalent cations is probably due to the improved efficiency of fluoride binding to bacterial cells being improved via these divalent cations.

  6. Chemical and botanical characterization of Chilean propolis and biological activity on cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus

    PubMed Central

    Barrientos, Leticia; Herrera, Christian L.; Montenegro, Gloria; Ortega, Ximena; Veloz, Jorge; Alvear, Marysol; Cuevas, Alejandro; Saavedra, Nicolás; Salazar, Luis A.

    2013-01-01

    Propolis is a non-toxic natural substance with multiple pharmacological properties including anti-cancer, antioxidant, fungicidal, antibacterial, antiviral, and anti-inflammatory among others. The aim of this study was to determine the chemical and botanical characterization of Chilean propolis samples and to evaluate their biological activity against the cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus. Twenty propolis samples were obtained from beekeeping producers from the central and southern regions of Chile. The botanical profile was determined by palynological analysis. Total phenolic contents were determined using colorimetric assays. Reverse phase HPLC and HPLC-MS were used to determine the chemical composition. The minimum inhibitory concentration (MIC) was determined on S. mutans and S. sobrinus. All propolis samples were dominated by structures from native plant species. The characterization by HPLC/MS, evidenced the presence of quercetin, myricetin, kaempferol, rutine, pinocembrin, coumaric acid, caffeic acid and caffeic acid phenethyl ester, that have already been described in these propolis with conventional HPLC. Although all propolis samples inhibited the mutans streptococci growth, it was observed a wide spectrum of action (MIC 0.90 to 8.22 μg mL−1). Given that results it becomes increasingly evident the need of standardization procedures, where we combine both the determination of botanical and the chemical characterization of the extracts. Research conducted to date, describes a promising effectiveness of propolis in the prevention of caries and other diseases of the oral cavity, making it necessary to develop studies to identify and understand the therapeutic targets or mechanisms of molecular action of the various compounds present on them. PMID:24294257

  7. Acidogenicity and acid tolerance of Streptococcus oralis and Streptococcus mitis isolated from plaque of healthy and incipient caries teeth

    PubMed Central

    Banas, Jeffrey A.; Zhu, Min; Dawson, Deborah V.; Blanchette, Derek R.; Drake, David R.; Gu, Hongjie; Frost, Ryan; McCaulley, Grant; Levy, Steven M.

    2016-01-01

    Background Non-mutans low pH oral streptococci are postulated to contribute to caries etiology. Objective This study was undertaken to investigate whether the acidogenicity and acid tolerance of clinical strains of Streptococcus oralis and Streptococcus mitis correlate with health or early-stage enamel caries. Design S. oralis and S. mitis were isolated from plaque samples taken from the occlusal surfaces of second molars sampled at two different visits 4 years apart. All sites were sound at Visit 1; subjects were segregated into one of three groups based on the status of the site at Visit 2 and caries elsewhere in the dentition. Strains of S. oralis and S. mitis were evaluated for acidogenicity and acid tolerance, and the results correlated with the clinical status of the sites from which they were isolated. Mutans streptococci (MS) isolated from the plaque samples were also quantified, and the presence or absence of growth on pH 5.5 media or on media selective for bifidobacteria was recorded. Results No significant positive correlations were found between the acidogenicity properties of the S. oralis and S. mitis clones and caries at either visit. Similar results were obtained for acid tolerance of S. oralis clones but were inconclusive for S. mitis clones. A statistically significant positive correlation between MS levels and caries (or future caries) was evident at both visits, but there were no statistical correlations with the growth on pH 5.5 media or media selective for bifidobacteria. Conclusions The low pH potential likely varies considerably among oral streptococcal species and is least likely to be found among strains of S. mitis. Accordingly, the concept and constitution of ‘low pH streptococci’ may need to be re-evaluated. PMID:27790973

  8. Influence of time, toothpaste and saliva in the retention of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes.

    PubMed

    Schmidt, Julia Caroline; Bux, Miriam; Filipuzzi-Jenny, Elisabeth; Kulik, Eva Maria; Waltimo, Tuomas; Weiger, Roland; Walter, Clemens

    2014-06-01

    The intraoral transmission of cariogenic and periodontopathogenic species seems to be facilitated by contaminated toothbrushes and other oral hygiene devices. The aim of this investigation was to analyze the in vitro retention and survival rate of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes. The impacts of human saliva and antimicrobial toothpaste on these parameters were further evaluated. Part I: Four toothbrushes (Colgate 360°, Curaprox CS5460 ultra soft, elmex InterX, Trisa Flexible Head3) were contaminated by S. mutans DSM 20523 or S. sanguinis DSM 20068 suspensions for three minutes. Bacteria were removed from the toothbrushes after either three minutes (T0) or 24 hours (T24) of dry storage and grown on Columbia blood agar plates for the quantification of colony-forming units (CFUs). Part II: The effects of saliva from a caries-active or a caries-inactive person and of toothpaste containing 0.12% chlorhexidine digluconate were also tested. Part I: After three minutes of dry storage, approximately one percent of the bacteria were still detectable on the toothbrushes. After 24 hours, S. sanguinis exhibited a more pronounced decrease in viable cell numbers compared with S. mutans but the differences were not significant (Kruskal-Wallis test, p>0.05). Part II: The addition of human saliva from a caries-active or caries-inactive person slightly increased the retention of both streptococcal species at T0. The use of toothpaste had no influence on the amount of viable streptococci at T0, but it reduced the microbial load after 24 hours of storage. There were only slight nonsignificant differences (p>0.05) between the four toothbrushes. In vitro bacterial retention and survival of S. sanguinis and S. mutans on different toothbrushes occurred. Within the limitations of this study, the use of human saliva or an antimicrobial toothpaste did not lead to significant differences in the microbial load on toothbrushes.

  9. Frequency of Spontaneous Resistance to Peptide Deformylase Inhibitor GSK1322322 in Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae.

    PubMed

    Min, Sharon; Ingraham, Karen; Huang, Jianzhong; McCloskey, Lynn; Rilling, Sarah; Windau, Anne; Pizzollo, Jason; Butler, Deborah; Aubart, Kelly; Miller, Linda A; Zalacain, Magdalena; Holmes, David J; O'Dwyer, Karen

    2015-08-01

    The continuous emergence of multidrug-resistant pathogenic bacteria is compromising the successful treatment of serious microbial infections. GSK1322322, a novel peptide deformylase (PDF) inhibitor, shows good in vitro antibacterial activity and has demonstrated safety and efficacy in human proof-of-concept clinical studies. In vitro studies were performed to determine the frequency of resistance (FoR) to this antimicrobial agent in major pathogens that cause respiratory tract and skin infections. Resistance to GSK1322322 occurred at high frequency through loss-of-function mutations in the formyl-methionyl transferase (FMT) protein in Staphylococcus aureus (4/4 strains) and Streptococcus pyogenes (4/4 strains) and via missense mutations in Streptococcus pneumoniae (6/21 strains), but the mutations were associated with severe in vitro and/or in vivo fitness costs. The overall FoR to GSK1322322 was very low in Haemophilus influenzae, with only one PDF mutant being identified in one of four strains. No target-based mutants were identified from S. pyogenes, and only one or no PDF mutants were isolated in three of the four S. aureus strains studied. In S. pneumoniae, PDF mutants were isolated from only six of 21 strains tested; an additional 10 strains did not yield colonies on GSK1322322-containing plates. Most of the PDF mutants characterized from those three organisms (35/37 mutants) carried mutations in residues at or in close proximity to one of three highly conserved motifs that are part of the active site of the PDF protein, with 30 of the 35 mutations occurring at position V71 (using the S. pneumoniae numbering system). Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  10. Phylogenetic, epidemiological and functional analyses of the Streptococcus bovis/Streptococcus equinus complex through an overarching MLST scheme.

    PubMed

    Jans, Christoph; de Wouters, Tomas; Bonfoh, Bassirou; Lacroix, Christophe; Kaindi, Dasel Wambua Mulwa; Anderegg, Janine; Böck, Désirée; Vitali, Sabrina; Schmid, Thomas; Isenring, Julia; Kurt, Fabienne; Kogi-Makau, Wambui; Meile, Leo

    2016-06-21

    The Streptococcus bovis/Streptococcus equinus complex (SBSEC) comprises seven (sub)species classified as human and animal commensals, emerging opportunistic pathogens and food fermentative organisms. Changing taxonomy, shared habitats, natural competence and evidence for horizontal gene transfer pose difficulties for determining their phylogeny, epidemiology and virulence mechanisms. Thus, novel phylogenetic and functional classifications are required. An SBSEC overarching multi locus sequence type (MLST) scheme targeting 10 housekeeping genes was developed, validated and combined with host-related properties of adhesion to extracellular matrix proteins (ECM), activation of the immune responses via NF-KB and survival in simulated gastric juice (SGJ). Commensal and pathogenic SBSEC strains (n = 74) of human, animal and food origin from Europe, Asia, America and Africa were used in the MLST scheme yielding 66 sequence types and 10 clonal complexes differentiated into distinct habitat-associated and mixed lineages. Adhesion to ECMs collagen I and mucin type II was a common characteristic (23 % of strains) followed by adhesion to fibronectin and fibrinogen (19.7 %). High adhesion abilities were found for East African dairy and human blood isolate branches whereas commensal fecal SBSEC displayed low adhesion. NF-KB activation was observed for a limited number of dairy and blood isolates suggesting the potential of some pathogenic strains for reduced immune activation. Strains from dairy MLST clades displayed the highest relative survival to SGJ independently of dairy adaptation markers lacS/lacZ. Combining phylogenetic and functional analyses via SBSEC MLST enabled the clear delineation of strain clades to unravel the complexity of this bacterial group. High adhesion values shared between certain dairy and blood strains as well as the behavior of NF-KB activation are concerning for specific lineages. They highlighted the health risk among shared lineages and

  11. Macrolide-Resistant Streptococcus pneumoniae and Streptococcus pyogenes in the Pediatric Population in Germany during 2000-2001

    PubMed Central

    Reinert, Ralf René; Lütticken, Rudolf; Bryskier, André; Al-Lahham, Adnan

    2003-01-01

    In a nationwide study in Germany covering 13 clinical microbiology laboratories, a total of 307 Streptococcus pyogenes (mainly pharyngitis) and 333 Streptococcus pneumoniae (respiratory tract infections) strains were collected from outpatients less than 16 years of age. The MICs of penicillin G, amoxicillin, cefotaxime, erythromycin A, clindamycin, levofloxacin, and telithromycin were determined by the microdilution method. In S. pyogenes isolates, resistance rates were as follows: penicillin, 0%; erythromycin A, 13.7%; and levofloxacin, 0%. Telithromycin showed good activity against S. pyogenes isolates (MIC90 = 0.25 μg/ml; MIC range, 0.016 to 16 μg/ml). Three strains were found to be telithromycin-resistant (MIC ≥ 4 μg/ml). Erythromycin-resistant strains were characterized for the underlying resistance genotype, with 40.5% having the efflux type mef(A), 38.1% having the erm(A), and 9.5% having the erm(B) genotypes. emm typing of macrolide-resistant S. pyogenes isolates showed emm types 4 (45.2%), 77 (26.2%), and 12 (11.9%) to be predominant. In S. pneumoniae, resistance rates were as follows: penicillin intermediate, 7.5%; penicillin resistant, 0%; erythromycin A, 17.4%; and levofloxacin, 0%. Telithromycin was highly active against pneumococcal isolates (MIC90 ≤ 0.016 μg/ml; range, 0.016 to 0.5 μg/ml). The overall resistance profile of streptococcal respiratory tract isolates is still favorable, but macrolide resistance is of growing concern in Germany. PMID:12543648

  12. Salivary density of Streptococcus mutans and Streptococcus sobrinus and dental caries in children and adolescents with Down syndrome

    PubMed Central

    SCALIONI, Flávia; CARRADA, Camila; MACHADO, Fernanda; Karina, DEVITO; RIBEIRO, Luiz Cláudio; CESAR, Dionéia; RIBEIRO, Rosangela

    2017-01-01

    Abstract Streptococcus mutans and Streptococcus sobrinus are strongly associated with dental caries. However, the relationship between oral streptococci and dental caries in children with Down syndrome is not well characterized. Objective To assess and compare dental caries experience and salivary S. mutans, S. sobrinus, and streptococci counts between groups of Down syndrome and non-Down syndrome children and adolescents. Material and Methods This study included a sample of 30 Down syndrome children and adolescents (G-DS) and 30 age- and sex-matched non-Down syndrome subjects (G-ND). Dental caries experience was estimated by the number of decayed, missing, and filled teeth in the primary dentition and the permanent dentition. Unstimulated whole saliva samples were collected from all participants. The fluorescence in situ hybridization technique was used to identify the presence and counts of the bacteria. The statistical analysis included chi-square, Student’s t-test and Spearman’s correlation. Results The G-DS exhibited a significantly higher caries-free rate (p<0.001) and a lower S. mutans salivary density (p<0.001). No significant differences were found in the salivary densities of S. sobrinus or streptococci between the groups (p=0.09 and p=0.21, respectively). The salivary S. mutans or S. sobrinus densities were not associated with dental caries experience in neither group. Conclusion The reduced dental caries experience observed in this group of Down syndrome children and adolescents cannot be attributed to lower salivary S. mutans densities, as determined with the fluorescence in situ hybridization technique. PMID:28678943

  13. Comparative Genomics Analysis of Streptococcus Isolates from the Human Small Intestine Reveals their Adaptation to a Highly Dynamic Ecosystem

    PubMed Central

    Van den Bogert, Bartholomeus; Boekhorst, Jos; Herrmann, Ruth; Smid, Eddy J.; Zoetendal, Erwin G.; Kleerebezem, Michiel

    2013-01-01

    The human small-intestinal microbiota is characterised by relatively large and dynamic Streptococcus populations. In this study, genome sequences of small-intestinal streptococci from S. mitis, S. bovis, and S. salivarius species-groups were determined and compared with those from 58 Streptococcus strains in public databases. The Streptococcus pangenome consists of 12,403 orthologous groups of which 574 are shared among all sequenced streptococci and are defined as the Streptococcus core genome. Genome mining of the small-intestinal streptococci focused on functions playing an important role in the interaction of these streptococci in the small-intestinal ecosystem, including natural competence and nutrient-transport and metabolism. Analysis of the small-intestinal Streptococcus genomes predicts a high capacity to synthesize amino acids and various vitamins as well as substantial divergence in their carbohydrate transport and metabolic capacities, which is in agreement with observed physiological differences between these Streptococcus strains. Gene-specific PCR-strategies enabled evaluation of conservation of Streptococcus populations in intestinal samples from different human individuals, revealing that the S. salivarius strains were frequently detected in the small-intestine microbiota, supporting the representative value of the genomes provided in this study. Finally, the Streptococcus genomes allow prediction of the effect of dietary substances on Streptococcus population dynamics in the human small-intestine. PMID:24386196

  14. Identification of "Streptococcus milleri" group isolates to the species level with a commercially available rapid test system.

    PubMed

    Flynn, C E; Ruoff, K L

    1995-10-01

    Clinical isolates of the "Streptococcus milleri" species group were examined by conventional methods and a rapid, commercially available method for the identification of these strains to the species level. The levels of agreement between the identifications obtained with the commercially available system (Fluo-Card Milleri; KEY Scientific, Round Rock, Tex.) and conventional methods were 98% for 50 Streptococcus anginosus strains, 97% for 31 Streptococcus constellatus strains, and 88% for 17 isolates identified as Streptococcus intermedius. Patient records were also studied in order to gain information on the frequency and sites of isolation of each of the three "S. milleri" group species.

  15. Comparative genomics analysis of Streptococcus isolates from the human small intestine reveals their adaptation to a highly dynamic ecosystem.

    PubMed

    Van den Bogert, Bartholomeus; Boekhorst, Jos; Herrmann, Ruth; Smid, Eddy J; Zoetendal, Erwin G; Kleerebezem, Michiel

    2013-01-01

    The human small-intestinal microbiota is characterised by relatively large and dynamic Streptococcus populations. In this study, genome sequences of small-intestinal streptococci from S. mitis, S. bovis, and S. salivarius species-groups were determined and compared with those from 58 Streptococcus strains in public databases. The Streptococcus pangenome consists of 12,403 orthologous groups of which 574 are shared among all sequenced streptococci and are defined as the Streptococcus core genome. Genome mining of the small-intestinal streptococci focused on functions playing an important role in the interaction of these streptococci in the small-intestinal ecosystem, including natural competence and nutrient-transport and metabolism. Analysis of the small-intestinal Streptococcus genomes predicts a high capacity to synthesize amino acids and various vitamins as well as substantial divergence in their carbohydrate transport and metabolic capacities, which is in agreement with observed physiological differences between these Streptococcus strains. Gene-specific PCR-strategies enabled evaluation of conservation of Streptococcus populations in intestinal samples from different human individuals, revealing that the S. salivarius strains were frequently detected in the small-intestine microbiota, supporting the representative value of the genomes provided in this study. Finally, the Streptococcus genomes allow prediction of the effect of dietary substances on Streptococcus population dynamics in the human small-intestine.

  16. Generation of Diversity in Streptococcus mutans Genes Demonstrated by MLST

    PubMed Central

    Do, Thuy; Gilbert, Steven C.; Clark, Douglas; Ali, Farida; Fatturi Parolo, Clarissa C.; Maltz, Marisa; Russell, Roy R.; Holbrook, Peter; Wade, William G.; Beighton, David

    2010-01-01

    Streptococcus mutans, consisting of serotypes c, e, f and k, is an oral aciduric organism associated with the initiation and progression of dental caries. A total of 135 independent Streptococcus mutans strains from caries-free and caries-active subjects isolated from various geographical locations were examined in two versions of an MLST scheme consisting of either 6 housekeeping genes [accC (acetyl-CoA carboxylase biotin carboxylase subunit), gki (glucokinase), lepA (GTP-binding protein), recP (transketolase), sodA (superoxide dismutase), and tyrS (tyrosyl-tRNA synthetase)] or the housekeeping genes supplemented with 2 extracellular putative virulence genes [gtfB (glucosyltransferase B) and spaP (surface protein antigen I/II)] to increase sequence type diversity. The number of alleles found varied between 20 (lepA) and 37 (spaP). Overall, 121 sequence types (STs) were defined using the housekeeping genes alone and 122 with all genes. However π, nucleotide diversity per site, was low for all loci being in the range 0.019–0.007. The virulence genes exhibited the greatest nucleotide diversity and the recombination/mutation ratio was 0.67 [95% confidence interval 0.3–1.15] compared to 8.3 [95% confidence interval 5.0–14.5] for the 6 concatenated housekeeping genes alone. The ML trees generated for individual MLST loci were significantly incongruent and not significantly different from random trees. Analysis using ClonalFrame indicated that the majority of isolates were singletons and no evidence for a clonal structure or evidence to support serotype c strains as the ancestral S. mutans strain was apparent. There was also no evidence of a geographical distribution of individual isolates or that particular isolate clusters were associated with caries. The overall low sequence diversity suggests that S. mutans is a newly emerged species which has not accumulated large numbers of mutations but those that have occurred have been shuffled as a consequence of intra

  17. Effects of Fluoride Varnish on Streptococcus mutans Count in Saliva

    PubMed Central

    Badjatia, Rini G; Thanveer, K; Krishnan, Ajith CG

    2017-01-01

    Aim To evaluate the effect of fluoride varnish on Streptococcus mutans count in saliva among 12-year-old school children. Materials and methods A field experiment was conducted to evaluate the effects of fluoride varnish on S. mutans count in saliva among 12-year-old school children. A total of 42 school-going children attending schools in Vadodara district, Gujarat, India, were divided into two groups. Group I was treated with fluoride varnish and group II received no treatment. Assessment of S. mutans was carried out at baseline and 3 to 6 months postfluoride varnish application. Friedman analysis of variance test and post hoc test were applied to detect statistically significant differences between baseline, 3 to 6 months of fluoride varnish application, and also between groups I and II. Results The mean number of salivary S. mutans value found in case group at baseline, 3 to 6 months was 31.23 ± 1.119, 9.27 ± 0.852, and 9.39 ± 0.908 × 104 colony-forming unit CFU/mL respectively. The difference in S. mutans count from baseline to 3 to 6 months was highly statistically significant (p = 0.000), but the difference from 3 to 6 months was not statistically significant (p = 0.142). In control group, the mean S. mutans value found at baseline, 3 to 6 months was 30.63 ± 1.436, 31.23 ± 1.351, and 31.40 ± 1.374 × 104 CFU/mL respectively. The differences between these values were not statistically significant (p = 0.11). Conclusion Statistically significant reduction in S. mutans count in saliva was seen 3 to 6 months after fluoride varnish application. How to cite this article Badjatia S, Badjatia RG, Thanveer K, Krishnan ACG. Effects of Fluoride Varnish on Streptococcus mutans Count in Saliva. Int J Clin Pediatr Dent 2017;10(1):62-66. PMID:28377658

  18. Recombinant production of Streptococcus equisimilis streptokinase by Streptomyces lividans

    PubMed Central

    Pimienta, Elsa; Ayala, Julio C; Rodríguez, Caridad; Ramos, Astrid; Van Mellaert, Lieve; Vallín, Carlos; Anné, Jozef

    2007-01-01

    Background Streptokinase (SK) is a potent plasminogen activator with widespread clinical use as a thrombolytic agent. It is naturally secreted by several strains of beta-haemolytic streptococci. The low yields obtained in SK production, lack of developed gene transfer methodology and the pathogenesis of its natural host have been the principal reasons to search for a recombinant source for this important therapeutic protein. We report here the expression and secretion of SK by the Gram-positive bacterium Streptomyces lividans. The structural gene encoding SK was fused to the Streptomyces venezuelae CBS762.70 subtilisin inhibitor (vsi) signal sequence or to the Streptomyces lividans xylanase C (xlnC) signal sequence. The native Vsi protein is translocated via the Sec pathway while the native XlnC protein uses the twin-arginine translocation (Tat) pathway. Results SK yield in the spent culture medium of S. lividans was higher when the Sec-dependent signal peptide mediates the SK translocation. Using a 1.5 L fermentor, the secretory production of the Vsi-SK fusion protein reached up to 15 mg SK/l. SK was partially purified from the culture supernatant by DEAE-Sephacel chromatography. A 44-kDa degradation product co-eluted with the 47-kDa mature SK. The first amino acid residues of the S. lividans-produced SK were identical with those of the expected N-terminal sequence. The Vsi signal peptide was thus correctly cleaved off and the N-terminus of mature Vsi-SK fusion protein released by S. lividans remained intact. This result also implicates that the processing of the recombinant SK secreted by Streptomyces probably occurred at its C-terminal end, as in its native host Streptococcus equisimilis. The specific activity of the partially purified Streptomyces-derived SK was determined at 2661 IU/mg protein. Conclusion Heterologous expression of Streptococcus equisimilis ATCC9542 skc-2 in Streptomyces lividans was successfully achieved. SK can be translocated via both the

  19. Effects of Carbohydrate Source on Genetic Competence in Streptococcus mutans

    PubMed Central

    Moye, Zachary D.; Son, Minjun; Rosa-Alberty, Ariana E.; Zeng, Lin; Ahn, Sang-Joon

    2016-01-01

    ABSTRACT The capacity to internalize and catabolize carbohydrates is essential for dental caries pathogens to persist and cause disease. The expression of many virulence-related attributes by Streptococcus mutans, an organism strongly associated with human dental caries, is influenced by the peptide signaling pathways that control genetic competence. Here, we demonstrate a relationship between the efficiency of competence signaling and carbohydrate source. A significant increase in the activity of the promoters for comX, comS, and comYA after exposure to competence-stimulating peptide (CSP) was observed in cells growing on fructose, maltose, sucrose, or trehalose as the primary carbohydrate source, compared to cells growing on glucose. However, only cells grown in the presence of trehalose or sucrose displayed a significant increase in transformation frequency. Notably, even low concentrations of these carbohydrates in the presence of excess glucose could enhance the expression of comX, encoding a sigma factor needed for competence, and the effects on competence were dependent on the cognate sugar:phosphotransferase permease for each carbohydrate. Using green fluorescent protein (GFP) reporter fusions, we observed that growth in fructose or trehalose resulted in a greater proportion of the population activating expression of comX and comS, encoding the precursor of comX-inducing peptide (XIP), after addition of CSP, than growth in glucose. Thus, the source of carbohydrate significantly impacts the stochastic behaviors that regulate subpopulation responses to CSP, which can induce competence in S. mutans. IMPORTANCE The signaling pathways that regulate development of genetic competence in Streptococcus mutans are intimately intertwined with the pathogenic potential of the organism, impacting biofilm formation, stress tolerance, and expression of known virulence determinants. Induction of the gene for the master regulator of competence, ComX, by competence

  20. Characterization of the adherence properties of Streptococcus salivarius.

    PubMed

    Weerkamp, A H; McBride, B C

    1980-08-01

    The adherence and aggregation properties of 46 human oral Streptococcus salivarius isolates were examined. A total of 41% of the isolates aggregated with whole human saliva, 50% aggregated with human erythrocytes, and 85% adhered to human buccal epithelial cells. Strains that aggregated with saliva and erythrocytes usually reacted with Streptococcus group K typing serum whereas the non-hemagglutinating strains did not. K+ strains also adhered more strongly to human buccal epithelial cells than K- strains. All isolates coaggregated with Fusobacterium nucleatum LF and Bacteroides asaccharolyticus 2D, 91% coaggregated with Veillonella alcalescens V1, and 50% coaggregated with Veillonella parvula V4. S. salivarius HB aggregated with saliva from 15 different human donors and aggregated with human erythrocytes irrespective of the blood group. This strain only weakly aggregated with rat saliva or rat erythrocytes. We isolated mutants which concomitantly lost the ability to agglutinate erythrocytes, aggregate with saliva, and bind to buccal epithelial cells, but retained their interbacterial aggregation properties. A second class of mutants lost the ability to coaggregate with Veillonella, but these mutants retained all of the other aggregation properties. Treatment of S. salivarius HB cells with pronase or subtilisin destroyed their ability to aggregate with saliva and erythrocytes and to bind to buccal epithelial cells. The unique characteristics of the aggregation and adherence reactions were suggested by differences in the rate of loss of activity during protease treatment and in the response to chemical modification. The presence of saliva did not affect hemagglutination and adherence to buccal epithelial cells. Binding of the salivary aggregating factor to the bacteria could be distinguished from aggregation on the basis that the latter required divalent cations. The factor involved in coaggregation with F. nucleatum LF was physicochemically different from the other

  1. Effects of Carbohydrate Source on Genetic Competence in Streptococcus mutans.

    PubMed

    Moye, Zachary D; Son, Minjun; Rosa-Alberty, Ariana E; Zeng, Lin; Ahn, Sang-Joon; Hagen, Stephen J; Burne, Robert A

    2016-08-01

    The capacity to internalize and catabolize carbohydrates is essential for dental caries pathogens to persist and cause disease. The expression of many virulence-related attributes by Streptococcus mutans, an organism strongly associated with human dental caries, is influenced by the peptide signaling pathways that control genetic competence. Here, we demonstrate a relationship between the efficiency of competence signaling and carbohydrate source. A significant increase in the activity of the promoters for comX, comS, and comYA after exposure to competence-stimulating peptide (CSP) was observed in cells growing on fructose, maltose, sucrose, or trehalose as the primary carbohydrate source, compared to cells growing on glucose. However, only cells grown in the presence of trehalose or sucrose displayed a significant increase in transformation frequency. Notably, even low concentrations of these carbohydrates in the presence of excess glucose could enhance the expression of comX, encoding a sigma factor needed for competence, and the effects on competence were dependent on the cognate sugar:phosphotransferase permease for each carbohydrate. Using green fluorescent protein (GFP) reporter fusions, we observed that growth in fructose or trehalose resulted in a greater proportion of the population activating expression of comX and comS, encoding the precursor of comX-inducing peptide (XIP), after addition of CSP, than growth in glucose. Thus, the source of carbohydrate significantly impacts the stochastic behaviors that regulate subpopulation responses to CSP, which can induce competence in S. mutans The signaling pathways that regulate development of genetic competence in Streptococcus mutans are intimately intertwined with the pathogenic potential of the organism, impacting biofilm formation, stress tolerance, and expression of known virulence determinants. Induction of the gene for the master regulator of competence, ComX, by competence-stimulating peptide (CSP

  2. Invasive disease by Streptococcus pyogenes: patients hospitalized for 6 years.

    PubMed

    Arias-Constantí, Vanessa; Trenchs-Sainz de la Maza, Victoria; Sanz-Marcos, Nuria Elvira; Guitart-Pardellans, Carmina; Gené-Giralt, Amadeu; Luaces-Cubells, Carles

    2017-07-10

    The last years an increase of severe cases of invasive disease (ID) due to Streptococcus pyogenes or streptococcus b-hemolytic group A (SGA) had been detected. The aim of this study was to analyze the epidemiology and the clinical features of ID due to SGA in a tertiary Pediatric Hospital. Retrospective study in a Pediatric hospital, of all in-patients with final diagnosis of ID due to SGA during 6 years (2009-2014). To consider ID, SGA had to be isolated in sterile samples; in patients with fascitis necroticans in skin samples or in any sample in patients with the diagnostic of Streptococcal Toxic Shock Syndrome (STSS). The SSTS was defined as hypotension and at least 2 of these criteria: renal failure, hepatic failure, acute respiratory distress, tissue necrosis or desquamative erythematous rash. Demographic data, type of infection, risk factors, clinical presentation, analytical data at admission, treatment, need for admission to a pediatric intensive care unit, microbiological data, hospital stay and evolution were collected. Fifty-two (52) cases were included (12/10,000 of all inpatients); 3 years-old was the medium age (p25-75: 1.4-6.9 years); 28 (53.8%) were boys. Fourteen patients (26.9%) had risk factors. Fever was the major symptom (51 patients, 98.1%). The skin lesions were the most frequent clinical manifestations found (21; 40.4%). In 50 (96%) cases, SGA was isolated in at least one sterile sample. Skin and soft tissue infections were diagnosed in 14 patients (26.9%), 14 (26.9%) pneumonias, 12 (23.1%) bones and joints infections, 10 (19.2%) SSTS, 6 (11.5%) occult bacteremia, 4 (7.7%) meningitis and 2 (3.8%) sepsis. Surgery was required in 18 cases (34.6%) and 17 patients (32.7%) needed intensive care. The medium hospital stay was 9.5 days (p25-75: 8-15 days). Three patients presented sequels and one patient died. The ID due to SGA was a rare but serious reason for hospital admission. Skin and soft tissue infections, and pleuroneumonia were the most

  3. Clinical evaluation of the oral probiotic Streptococcus salivarius K12 in the prevention of recurrent pharyngitis and/or tonsillitis caused by Streptococcus pyogenes in adults.

    PubMed

    Di Pierro, Francesco; Adami, Teresa; Rapacioli, Giuliana; Giardini, Nadia; Streitberger, Christian

    2013-03-01

    Streptococcus salivarius K12 has been shown to inhibit the growth of Streptococcus pyogenes due to bacteriocins release. Because of its ability to colonize the oral cavity, we have tested the strain K12 for its efficacy in preventing streptococcal pharyngitis and/or tonsillitis in adults. Forty adults with a diagnosis of recurrent oral streptococcal pharyngitis were enrolled in the study. Twenty of these subjects took for 90 days a tablet containing Streptococcus salivarius K12 (Bactoblis®). The other 20 subjects served as untreated controls. A 6-month follow-up was included to evaluate any persistent protective role. The 20 adults who completed the 90-day course of Bactoblis® showed a reduction in their episodes of streptococcal pharyngeal infection (about 80%). The 90 days treatment was also associated with an approximately 60% reduction in the incidence of reported pharyngitis in the 6-month period following use of the product. The product was well tolerated by the subjects with no treatment-related side effects or drop-outs reported. Prophylactic administration of Streptococcus salivarius K12 to adults having a history of recurrent oral streptococcal pathology reduced the number of episodes of streptococcal pharyngeal infections and/or tonsillitis.

  4. Streptococcus mutans and Streptococcus sobrinus detection by Polymerase Chain Reaction and their relation to dental caries in 12 and 15 year-old schoolchildren in Valencia (Spain).

    PubMed

    Sánchez-Acedo, Mateo; Montiel-Company, José-María; Dasí-Fernández, Francisco; Almerich-Silla, José-Manuel

    2013-11-01

    A cross-sectional study was carried out to determine the prevalence of Streptococcus mutans and Streptococcus sobrinus and the association of the two in a random sample (n=614) of the child population of the region of Valencia (Spain). Saliva samples were analyzed by the quantitative polymerase chain reaction (PCR) method to study the relation of these bacteria to caries prevalence and the DMFT index. The prevalence of S. mutans was 35.4% at age 12 and 22.9% at age 15, that of S. sobrinus 18.9% and 8.4% and that of the S. mutans-S. sobrinus association 18.2% and 6.8% respectively. At both 12 and 15 years of age, the caries prevalence rates were lower in the Streptococcus-free group of children (37.6% and 48.5% respectively) and higher in the S.mutans-only group (67.3% and 74.0%). At the age of 12, the DMFT index was significantly higher in the mutans-only carriers (2.1) than in the Streptococcus-free and S. mutans-S. sobrinus association groups (both 0.9). At the age of 15, the DMFT index was significantly higher in the S. mutans-S. sobrinus association (3.71) and mutans-only (3.1) carrier groups than in the Streptococcus-free group (1.4). Determination of S. mutans and S. sobrinus by real-time quantitative PCR can provide valuable information for caries risk assessment in epidemiological studies.

  5. Cytosolic Replication of Group A Streptococcus in Human Macrophages

    PubMed Central

    O’Neill, Alan M.; Thurston, Teresa L. M.

    2016-01-01

    ABSTRACT As key components of innate immune defense, macrophages are essential in controlling bacterial pathogens, including group A Streptococcus (GAS). Despite this, only a limited number of studies have analyzed the recovery of GAS from within human neutrophils and macrophages. Here, we determined the intracellular fate of GAS in human macrophages by using several quantitative approaches. In both U937 and primary human macrophages, the appearance over time of long GAS chains revealed that despite GAS-mediated cytotoxicity, replication occurred in viable, propidium iodide-negative macrophages. Whereas the major virulence factor M1 did not contribute to bacterial growth, a GAS mutant strain deficient in streptolysin O (SLO) was impaired for intracellular replication. SLO promoted bacterial escape from the GAS-containing vacuole (GCV) into the macrophage cytosol. Up to half of the cytosolic GAS colocalized with ubiquitin and p62, suggesting that the bacteria were targeted by the autophagy machinery. Despite this, live imaging of U937 macrophages revealed proficient replication of GAS after GCV rupture, indicating that escape from the GCV is important for growth of GAS in macrophages. Our results reveal that GAS can replicate within viable human macrophages, with SLO promoting GCV escape and cytosolic growth, despite the recruitment of autophagy receptors to bacteria. PMID:27073088

  6. Transcriptional Regulation of the Streptococcus salivarius 57.I Urease Operon

    PubMed Central

    Chen, Yi-Ywan M.; Weaver, Cheryl A.; Mendelsohn, David R.; Burne, Robert A.

    1998-01-01

    The Streptococcus salivarius 57.I ure cluster was organized as an operon, beginning with ureI, followed by ureABC (structural genes) and ureEFGD (accessory genes). Northern analyses revealed transcripts encompassing structural genes and transcripts containing the entire operon. A ς70-like promoter could be mapped 5′ to ureI (PureI) by primer extension analysis. The intensity of the signal increased when cells were grown at an acidic pH and was further enhanced by excess carbohydrate. To determine the function(s) of two inverted repeats located 5′ to PureI, transcriptional fusions of the full-length promoter region (PureI), or a deletion derivative (PureIΔ100), and a promoterless chloramphenicol acetyltransferase (CAT) gene were constructed and integrated into the chromosome to generate strains PureICAT and PureIΔ100CAT, respectively. CAT specific activities of PureICAT were repressed at pH 7.0 and induced at pH 5.5 and by excess carbohydrate. In PureIΔ100CAT, CAT activity was 60-fold higher than in PureICAT at pH 7.0 and pH induction was nearly eliminated, indicating that expression was negatively regulated. Thus, it was concluded that PureI was the predominant, regulated promoter and that regulation was governed by a mechanism differing markedly from other known mechanisms for bacterial urease expression. PMID:9791132

  7. A novel endolysin disrupts Streptococcus suis with high efficiency.

    PubMed

    Ji, Wenhui; Huang, Qingqing; Sun, Liang; Wang, Hengan; Yan, Yaxian; Sun, Jianhe

    2015-12-01

    Streptococcus suis serotype 2 (S. suis 2) is a zoonotic pathogen that exhibits high-level resistance and multi-drug resistance to classic antibiotics and causes serious human casualties and heavy economic losses in the swine industry worldwide. Therefore, alternative therapies or novel antibacterial agents need to be developed to combat this pathogen. A novel endolysin derived from the S. suis temperate phage phi7917, termed Ly7917, was identified, which had broad lytic activity against S. suis type 1, 2, 7 and 9. Ly7917 consisted of an N-terminal cysteine, histidine-dependent amidohydrolases/peptidase catalytic domain and C-terminal SH3b cell wall binding domain. The endolysin maintained activity at high pH and its catalytic activity could be improved by addition of 10 μM 1.5 mM Ca(2+). In animal studies, 90% of BALB/c mice challenged with typical virulent strain HA9801 of S. suis 2 were protected by Ly7917 treatment. The bacterial load in the blood of HA9801-challenged mice was efficiently reduced almost 50% by Ly7917 while that of penicillin-G-treated mice kept almost unchanged. Our data suggest that Ly7917 may be an alternative therapeutic agent for infections caused by virulent S. suis strains.

  8. Effect of Streptococcus pneumoniae on human respiratory epithelium in vitro.

    PubMed

    Steinfort, C; Wilson, R; Mitchell, T; Feldman, C; Rutman, A; Todd, H; Sykes, D; Walker, J; Saunders, K; Andrew, P W

    1989-07-01

    A total of 11 of 15 Streptococcus pneumoniae culture filtrates and all five bacterial autolysates produced by cell death in the stationary phase caused slowed ciliary beating and disruption of the surface integrity of human respiratory epithelium in organ culture. This effect was inhibited by cholesterol and was heat labile and reduced by standing at room temperature but was stable at -40 degrees C. The activity was detected at the late stationary phase of culture and was associated with the presence of hemolytic activity. Gel filtration of a concentrated culture filtrate and autolysate both yielded a single fraction of approximately 50 kilodaltons which slowed ciliary beating and were the only fractions with hemolytic activity. Rabbit antiserum to pneumolysin, a sulfhydryl-activated hemolytic cytotoxin released by S. pneumoniae during autolysis, neutralized the effect of the culture filtrate on respiratory epithelium. Both native and recombinant pneumolysin caused ciliary slowing and epithelial disruption. Electron microscopy showed a toxic effect of pneumolysin on epithelial cells: cytoplasmic blebs, mitochondrial swelling, cellular extrusion, and cell death, but no change in ciliary ultrastructure. Recombinant pneumolysin (10 micrograms/ml) caused ciliary slowing in the absence of changes in cell ultrastructure. Release of pneumolysin in the respiratory tract during infection may perturb host defenses, allowing bacterial proliferation and spread.

  9. Evolutionary inactivation of a sialidase in group B Streptococcus

    PubMed Central

    Yamaguchi, Masaya; Hirose, Yujiro; Nakata, Masanobu; Uchiyama, Satoshi; Yamaguchi, Yuka; Goto, Kana; Sumitomo, Tomoko; Lewis, Amanda L.; Kawabata, Shigetada; Nizet, Victor

    2016-01-01

    Group B Streptococcus (GBS) is a leading cause of bacterial sepsis and meningitis in newborns. GBS possesses a protein with homology to the pneumococcal virulence factor, NanA, which has neuraminidase (sialidase) activity and promotes blood-brain barrier penetration. However, phylogenetic sequence and enzymatic analyses indicate the GBS NanA ortholog has lost sialidase function – and for this distinction we designate the gene and encoded protein nonA/NonA. Here we analyze NonA function in GBS pathogenesis, and through heterologous expression of active pneumococcal NanA in GBS, potential costs of maintaining sialidase function. GBS wild-type and ΔnonA strains lack sialidase activity, but forced expression of pneumococcal NanA in GBS induced degradation of the terminal sialic acid on its exopolysaccharide capsule. Deletion of nonA did not change GBS-whole blood survival or brain microvascular cell invasion. However, forced expression of pneumococcal NanA in GBS removed terminal sialic acid residues from the bacterial capsule, restricting bacterial proliferation in human blood and in vivo upon mouse infection. GBS expressing pneumococcal NanA had increased invasion of human brain microvascular endothelial cells. Thus, we hypothesize that nonA lost enzyme activity allowing the preservation of an effective survival factor, the sialylated exopolysaccharide capsule. PMID:27352769

  10. Characterization of Pit, a Streptococcus pneumoniae Iron Uptake ABC Transporter

    PubMed Central

    Brown, Jeremy S.; Gilliland, Sarah M.; Ruiz-Albert, Javier; Holden, David W.

    2002-01-01

    Bacteria frequently have multiple mechanisms for acquiring iron, an essential micronutrient, from the environment. We have identified a four-gene Streptococcus pneumoniae operon, named pit, encoding proteins with similarity to components of a putative Brachyspira hyodysenteriae iron uptake ABC transporter, Bit. An S. pneumoniae strain containing a defined mutation in pit has impaired growth in medium containing the iron chelator ethylenediamine di-o-hydroxyphenylacetic acid, reduced sensitivity to the iron-dependent antibiotic streptonigrin, and impaired virulence in a mouse model of S. pneumoniae systemic infection. Furthermore, addition of a mutation in pit to a strain containing mutations in the two previously described S. pneumoniae iron uptake ABC transporters, piu and pia, resulted in a strain with impaired growth in two types of iron-deficient medium, a high degree of resistance to streptonigrin, and a reduced rate of iron uptake. Comparison of the susceptibilities to streptonigrin of the individual pit, piu, and pia mutant strains and comparison of the growth in iron-deficient medium and virulence of single and double mutant strains suggest that pia is the dominant iron transporter during in vitro and in vivo growth. PMID:12117949

  11. Role of the Vegetation in Experimental Streptococcus viridans Endocarditis

    PubMed Central

    Hook, Edward W.; Sande, Merle A.

    1974-01-01

    This study examines the role of the vegetation in catheter-induced experimental endocarditis in predisposing to bacterial colonization of cardiac valves and in influencing the course of the disease and response to penicillin therapy. Platelet-fibrin vegetations developed at areas of valvular trauma and were colonized when Streptococcus viridans were injected intravenously. Pretreatment with warfarin prevented vegetation formation, but animals still developed endocarditis at the same rate after injection of 106S. viridans. The course of the disease in anticoagulated animals was more explosive, as determined by a more rapid rise in fever and level of bacteremia. Mean survival was shorter in anticoagulated rabbits (7 versus 12.7 days). Large vegetations containing 109S. viridans/g were found in control animals, whereas anticoagulated rabbits developed only microscopic deposits. Large vegetations required a longer duration of penicillin therapy to sterilize than the infected valves of the anticoagulated group (7 versus 3 days). Therefore, a preformed platelet-fibrin deposit is not a prerequisite for bacterial colonization of cardiac valves. After infection, the vegetation is an important factor in determining the subacute course of disease and resistance to penicillin therapy. Images PMID:4497487

  12. The alpha-hemolysin of Streptococcus gordonii is hydrogen peroxide.

    PubMed Central

    Barnard, J P; Stinson, M W

    1996-01-01

    The alpha-hemolysin of viridans group streptococci, which causes greening of intact erythrocytes, is a potential virulence factor as well as an important criterion for the laboratory identification of these bacteria; however, it has never been purified and characterized. The alpha-hemolysin of Streptococcus gordonii CH1 caused characteristic shifts in the A403, A430, A578, and A630 of sheep hemoglobin. A spectrophotometric assay was developed and used to monitor purification of alpha-hemolysin during extraction in organic solvents and separation by reverse-phase high-performance liquid chromatography (HPLC). The alpha-hemolysin was identical to hydrogen peroxide with respect to its effects on erythrocyte hemoglobin, oxygen-dependent synthesis by streptococci, insensitivity to proteases, inactivation by catalase, differential solubility, failure to adsorb to ion-exchange chromatography resins, and retention time on a reverse-phase HPLC column. The amount of hydrogen peroxide present in HPLC-fractionated spent culture medium was sufficient to account for all alpha-hemolytic activity observed. PMID:8751938

  13. Corrosion of dental alloys in artificial saliva with Streptococcus mutans

    PubMed Central

    Lu, Chunhui; Zheng, Yuanli; Zhong, Qun

    2017-01-01

    A comparative study of the corrosion resistance of CoCr and NiCr alloys in artificial saliva (AS) containing tryptic soy broth (Solution 1) and Streptococcus mutans (S. mutans) species (Solution 2) was performed by electrochemical methods, including open circuit potential measurements, impedance spectroscopy, and potentiodynamic polarization. The adherence of S. mutans to the NiCr and CoCr alloy surfaces immersed in Solution 2 for 24 h was verified by scanning electron microscopy, while the results of electrochemical impedance spectroscopy confirmed the importance of biofilm formation for the corrosion process. The R(QR) equivalent circuit was successfully used to fit the data obtained for the AS mixture without S. mutans, while the R(Q(R(QR))) circuit was found to be more suitable for describing the biofilm properties after treatment with the AS containing S. mutans species. In addition, a negative shift of the open circuit potential with immersion time was observed for all samples regardless of the solution type. Both alloys exhibited higher charge transfer resistance after treatment with Solution 2, and lower corrosion current densities were detected for all samples in the presence of S. mutans. The obtained results suggest that the biofilm formation observed after 24 h of exposure to S. mutans bacteria might enhance the corrosion resistance of the studied samples by creating physical barriers that prevented oxygen interactions with the metal surfaces. PMID:28350880

  14. Cationic antimicrobial peptides disrupt the Streptococcus pyogenes ExPortal.

    PubMed

    Vega, Luis Alberto; Caparon, Michael G

    2012-09-01

    Although they possess a well-characterized ability to porate the bacterial membrane, emerging research suggests that cationic antimicrobial peptides (CAPs) can influence pathogen behaviour at levels that are sublethal. In this study, we investigated the interaction of polymyxin B and human neutrophil peptide (HNP-1) with the human pathogen Streptococcus pyogenes. At sublethal concentrations, these CAPs preferentially targeted the ExPortal, a unique microdomain of the S. pyogenes membrane, specialized for protein secretion and processing. A consequence of this interaction was the disruption of ExPortal organization and a redistribution of ExPortal components into the peripheral membrane. Redistribution was associated with inhibition of secretion of certain toxins, including the SpeB cysteine protease and the streptolysin O (SLO) cytolysin, but not SIC, a protein that protects S. pyogenes from CAPs. These data suggest a novel function for CAPs in targeting the ExPortal and interfering with secretion of factors required for infection and survival. This mechanism may prove valuable for the design of new types of antimicrobial agents to combat the emergence of antibiotic-resistant pathogens.

  15. Flamingo cadherin: a putative host receptor for Streptococcus pneumoniae.

    PubMed

    Blau, Karin; Portnoi, Maxim; Shagan, Marilou; Kaganovich, Antonina; Rom, Slava; Kafka, Daniel; Chalifa Caspi, Vered; Porgador, Angel; Givon-Lavi, Noga; Gershoni, Jonathan M; Dagan, Ron; Mizrachi Nebenzahl, Yaffa

    2007-06-15

    Streptococcus pneumoniae fructose bisphosphate aldolase (FBA) is a cell wall-localized lectin. We demonstrate that recombinant (r) FBA and anti-rFBA antibodies inhibit encapsulated and unencapsulated S. pneumoniae serotype 3 adherence to A549 type II lung carcinoma epithelial cells. A random combinatorial peptide library expressed by filamentous phage was screened with rFBA. Eleven of 30 rFBA-binding phages inhibited 90% of S. pneumoniae adhesion to A549 cells. The insert peptide sequence of 9 of these phages matched the Flamingo cadherin receptor (FCR) when aligned against the human genome. A peptide comprising a putative FBA-binding region of FCR (FCRP) inhibited 2 genetically and capsularly unrelated pairs of encapsulated and unencapsulated S. pneumoniae strains from binding to A549 cells. Moreover, FCRP inhibited S. pneumoniae nasopharyngeal and lung colonization and, possibly, pneumonia development in the mouse intranasal inoculation model system. These data indicate that FBA is an S. pneumoniae adhesin and that FCR is its host receptor.

  16. Kinetics of Coinfection with Influenza A Virus and Streptococcus pneumoniae

    SciTech Connect

    Smith, Amber M.; Adler, Frederick R.; Ribeiro, Ruy M.; Gutenkunst, Ryan N.; McAuley, Julie L.; McCullers, Jonathan A.; Perelson, Alan S.

    2013-03-21

    Secondary bacterial infections are a leading cause of illness and death during epidemic and pandemic influenza. Experimental studies suggest a lethal synergism between influenza and certain bacteria, particularly Streptococcus pneumoniae, but the precise processes involved are unclear. In this paper, to address the mechanisms and determine the influences of pathogen dose and strain on disease, we infected groups of mice with either the H1N1 subtype influenza A virus A/Puerto Rico/8/34 (PR8) or a version expressing the 1918 PB1-F2 protein (PR8-PB1-F2(1918)), followed seven days later with one of two S. pneumoniae strains, type 2 D39 or type 3 A66.1. We determined that, following bacterial infection, viral titers initially rebound and then decline slowly. Bacterial titers rapidly rise to high levels and remain elevated. We used a kinetic model to explore the coupled interactions and study the dominant controlling mechanisms. We hypothesize that viral titers rebound in the presence of bacteria due to enhanced viral release from infected cells, and that bacterial titers increase due to alveolar macrophage impairment. Dynamics are affected by initial bacterial dose but not by the expression of the influenza 1918 PB1-F2 protein. Finally, our model provides a framework to investigate pathogen interaction during coinfections and to uncover dynamical differences based on inoculum size and strain.

  17. Effects of Suilysin on Streptococcus suis-Induced Platelet Aggregation

    PubMed Central

    Zhang, Shengwei; Wang, Junping; Chen, Shaolong; Yin, Jiye; Pan, Zhiyuan; Liu, Keke; Li, Lin; Zheng, Yuling; Yuan, Yuan; Jiang, Yongqiang

    2016-01-01

    Blood platelets play important roles during pathological thrombocytopenia in streptococcal toxic shock syndrome (STSS). Streptococcus suis (S. suis) an emerging human pathogen, can cause STSS similarly to S. pyogenes. However, S. suis interactions with platelets are poorly understood. Here, we found that suilysin (SLY), different from other bacterial cholesterol-dependent cytolysins (CDCs), was the sole stimulus that induced platelet aggregation. Furthermore, the inside-out activation of GPIIb/IIIa of platelets mediated SLY-induced platelet aggregation. This process was triggered by Ca2+ influx that depend on the pore forming on platelets by SLY. Additionally, although SLY induced α-granule release occurred via the MLCK-dependent pathway, PLC-β-IP3/DAG-MLCK and Rho-ROCK-MLCK signaling were not involved in SLY-induced platelet aggregation. Interestingly, the pore dependent Ca2+ influx was also found to participate in the induction of platelet aggregation with pneumolysin (PLY) and streptolysin O (SLO), two other CDCs. It is possible that the CDC-mediated platelet aggregation we observed in S. suis is a similar response mechanism to that used by a wide range of bacteria. These findings might lead to the discovery of potential therapeutic targets for S. suis-associated STSS. PMID:27800304

  18. Structural genomics studies of human caries pathogen Streptococcus mutans.

    PubMed

    Li, Lanfen; Nan, Jie; Li, Dan; Brostromer, Erik; Wang, Zixi; Liu, Cong; Hou, Qiaoming; Fan, Xuexin; Ye, Zhaoyang; Su, Xiao-Dong

    2014-09-01

    Gram-positive bacterium Streptococcus mutans is the primary causative agent of human dental caries. To better understand this pathogen at the atomic structure level and to establish potential drug and vaccine targets, we have carried out structural genomics research since 2005. To achieve the goal, we have developed various in-house automation systems including novel high-throughput crystallization equipment and methods, based on which a large-scale, high-efficiency and low-cost platform has been establish in our laboratory. From a total of 1,963 annotated open reading frames, 1,391 non-membrane targets were selected prioritized by protein sequence similarities to unknown structures, and clustered by restriction sites to allow for cost-effective high-throughput conventional cloning. Selected proteins were over-expressed in different strains of Escherichia coli. Clones expressed soluble proteins were selected, expanded, and expressed proteins were purified and subjected to crystallization trials. Finally, protein crystals were subjected to X-ray analysis and structures were determined by crystallographic methods. Using the previously established procedures, we have so far obtained more than 200 kinds of protein crystals and 100 kinds of crystal structures involved in different biological pathways. In this paper we demonstrate and review a possibility of performing structural genomics studies at moderate laboratory scale. Furthermore, the techniques and methods developed in our study can be widely applied to conventional structural biology research practice.

  19. Identification of essential amino acids in the Streptococcus mutans glucosyltransferases.

    PubMed Central

    Tsumori, H; Minami, T; Kuramitsu, H K

    1997-01-01

    A comparison of the amino acid sequences of the glucosyltransferases (GTFs) of mutans streptococci with those from the alpha-amylase family of enzymes revealed a number of conserved amino acid positions which have been implicated as essential in catalysis. Utilizing a site-directed mutagenesis approach with the GTF-I enzyme of Streptococcus mutans GS-5, we identified three of these conserved amino acid positions, Asp413, Trp491, and His561, as being important in enzymatic activity. Mutagenesis of Asp413 to Thr resulted in a GTF which expressed only about 12% of the wild-type activity. In contrast, mutagenesis of Asp411 did not inhibit enzyme activity. In addition, the D413T mutant was less stable than was the parental enzyme when expressed in Escherichia coli. Moreover, conversion of Trp491 or His561 to either Gly or Ala resulted in enzymes devoid of GTF activity, indicating the essential nature of these two amino acids for activity. Furthermore, mutagenesis of the four Tyr residues present at positions 169 to 172 which are part of a subdomain with homology to the direct repeating sequences present in the glucan-binding domain of the GTFs had little overall effect on enzymatic activity, although the glucan products appeared to be less adhesive. These results are discussed relative to the mechanisms of catalysis proposed for the GTFs and related enzymes. PMID:9171379

  20. Immunological relationships between glucosyltransferases from Streptococcus mutans serotypes.

    PubMed Central

    Kuramitsu, H; Ingersoll, L

    1976-01-01

    Partially purified glycosyltransferase enzymes for Streptococcus mutans GS-5 (serotype c) have been utilized to prepare antibodies directed against the soluble glucan-synthesizing activity, GTF-B, and the insoluble-soluble glucan synthetic activity, GTF-A. Anti-GTF-A inhibited insoluble glucan formation catalyzed by the extracellular enzymes from strains GS-5 and FA-1 (serotype b) to a much greater extent than that of strains HS-6 (serotype a) or OMZ-176 (serotype d). This antibody fraction also inhibited both the cell-associated glucosyltransferase activities as well as the sucrose-mediated adherence of cells to glass surfaces by strains GS-5 and FA-1 but not that of strains HS-6 and OMZ-176. Anti-GTF-B inhibited soluble glucan formation catalyzed by the extracellular enzymes of strains GS-5 but not that of strain HS-6, FA-1, or OMZ-176. However, this antibody fraction did not strongly inhibit either the cell-associated glycosyltransferase activity or cellular adherence of any of the four strains. These results with body antibody fractions were also correlated with the ability of the antibodies to agglutinate the cells and form precipitin bands after immunodiffusion with the extracellular enzymes. Antibody prepared against the homogeneous soluble glucan-synthesizing enzyme demonstrated similar effects to the anti-GTF-B fraction. These results are discussed in terms of the antigenic relationships existing between the glucosyltransferases from different serotypes of S. mutans. PMID:965089

  1. Metabolic engineering of acetaldehyde production by Streptococcus thermophilus.

    PubMed

    Chaves, A C S D; Fernandez, M; Lerayer, A L S; Mierau, I; Kleerebezem, M; Hugenholtz, J

    2002-11-01

    The process of acetaldehyde formation by the yogurt bacterium Streptococcus thermophilus is described in this paper. Attention was focused on one specific reaction for acetaldehyde formation catalyzed by serine hydroxymethyltransferase (SHMT), encoded by the glyA gene. In S. thermophilus, SHMT also possesses threonine aldolase (TA) activity, the interconversion of threonine into glycine and acetaldehyde. In this work, several wild-type S. thermophilus strains were screened for acetaldehyde production in the presence and absence of L-threonine. Supplementation of the growth medium with L-threonine led to an increase in acetaldehyde production. Furthermore, acetaldehyde formation during fermentation could be correlated to the TA activity of SHMT. To study the physiological role of SHMT, a glyA mutant was constructed by gene disruption. Inactivation of glyA resulted in a severe reduction in TA activity and complete loss of acetaldehyde formation during fermentation. Subsequently, an S. thermophilus strain was constructed in which the glyA gene was cloned under the control of a strong promoter (P(LacA)). When this strain was used for fermentation, an increase in TA activity and in acetaldehyde and folic acid production was observed. These results show that, in S. thermophilus, SHMT, displaying TA activity, constitutes the main pathway for acetaldehyde formation under our experimental conditions. These findings can be used to control and improve acetaldehyde production in fermented (dairy) products with S. thermophilus as starter culture.

  2. Monofluorophosphate Blocks Internal Polysaccharide Synthesis in Streptococcus mutans

    PubMed Central

    Naleway, Conrad; Iglesias, Alberto A.; Ballicora, Miguel A.

    2017-01-01

    Streptococcus mutans is the leading cause of dental caries worldwide by accumulating a glycogen-like internal polysaccharide (IPS) that contributes to cariogenicity when sugars are in excess. Sodium monofluorophosphate (MFP) is an active anticariogenic compound in toothpastes. Herein, we show that MFP inhibits (with an I0.5 of 1.5 mM) the S. mutans ADP-glucose pyrophosphorylase (EC 2.7.7.27), which catalyzes the key step in IPS biosynthesis. Enzyme inhibition by MFP is similar to orthophosphate (Pi), except that the effect caused by MFP is not reverted by fructose-1,6-bisP, as occurs with Pi. Inhibition was correlated with a decrease in acidogenesis and IPS accumulation in S. mutans cells cultured with 2 mM sodium MFP. These effects were not mimicked by sodium fluoride. Considering that glycogen synthesis occurs by different pathways in mammals and bacteria, ADP-glucose pyrophosphorylase could be visualized as a molecular target for controlling S. mutans virulence. Our results strongly suggest that MFP is a suitable compound to affect such a target, inducing an anticariogenic effect primarily by inhibiting a key step in IPS synthesis. PMID:28125652

  3. Kaffir lime leaves extract inhibits biofilm formation by Streptococcus mutans.

    PubMed

    Kooltheat, Nateelak; Kamuthachad, Ludthawun; Anthapanya, Methinee; Samakchan, Natthapon; Sranujit, Rungnapa Pankla; Potup, Pachuen; Ferrante, Antonio; Usuwanthim, Kanchana

    2016-04-01

    Although kaffir lime has been reported to exhibit antioxidant and antileukemic activity, little is known about the antimicrobial effect of kaffir lime extract. Because Streptococcus mutans has been known to cause biofilm formation, it has been considered the most important causative pathogen of dental caries. Thus, the effective control of its effects on the oral biofilm is the key to the prevention of dental caries. The aims of the present study were to investigate the effect of kaffir lime leaves extract on biofilm formation and its antibacterial activity on S. mutans. We examined the effect of kaffir lime leaves extract on growth and biofilm formation of S. mutans. For the investigation we used a kaffir lime extract with high phenolic content. The minimum inhibitory concentration of the extract was determined by broth microdilution assay. The inhibitory effect of the test substances on biofilm formation was also investigated by biofilm formation assay and qRT-PCR of biofilm formation-associated genes. Kaffir lime leaves extract inhibits the growth of S. mutans, corresponding to the activity of an antibiotic, ampicillin. Formation of biofilm by S. mutans was also inhibited by the extract. These results were confirmed by the down-regulation of genes associated with the biofilm formation. The findings highlight the ability of kaffir lime leaves extract to inhibit S. mutans activity, which may be beneficial in the prevention of biofilm formation on dental surface, reducing dental plaque and decreasing the chance of dental carries. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. AdcAII of Streptococcus pneumoniae Affects Pneumococcal Invasiveness

    PubMed Central

    Brown, Lindsey R.; Gunnell, Steven M.; Cassella, Adam N.; Keller, Lance E.; Scherkenbach, Lisa A.; Mann, Beth; Brown, Matthew W.; Hill, Rebecca; Fitzkee, Nicholas C.; Rosch, Jason W.; Tuomanen, Elaine I.; Thornton, Justin A.

    2016-01-01

    Across bacterial species, metal binding proteins can serve functions in pathogenesis in addition to regulating metal homeostasis. We have compared and contrasted the activities of zinc (Zn2+)-binding lipoproteins AdcA and AdcAII in the Streptococcus pneumoniae TIGR4 background. Exposure to Zn2+-limiting conditions resulted in delayed growth in a strain lacking AdcAII (ΔAdcAII) when compared to wild type bacteria or a mutant lacking AdcA (ΔAdcA). AdcAII failed to interact with the extracellular matrix protein laminin despite homology to laminin-binding proteins of related streptococci. Deletion of AdcA or AdcAII led to significantly increased invasion of A549 human lung epithelial cells and a trend toward increased invasion in vivo. Loss of AdcAII, but not AdcA, was shown to negatively impact early colonization of the nasopharynx. Our findings suggest that expression of AdcAII affects invasiveness of S. pneumoniae in response to available Zn2+ concentrations. PMID:26752283

  5. Corrosion of dental alloys in artificial saliva with Streptococcus mutans.

    PubMed

    Lu, Chunhui; Zheng, Yuanli; Zhong, Qun

    2017-01-01

    A comparative study of the corrosion resistance of CoCr and NiCr alloys in artificial saliva (AS) containing tryptic soy broth (Solution 1) and Streptococcus mutans (S. mutans) species (Solution 2) was performed by electrochemical methods, including open circuit potential measurements, impedance spectroscopy, and potentiodynamic polarization. The adherence of S. mutans to the NiCr and CoCr alloy surfaces immersed in Solution 2 for 24 h was verified by scanning electron microscopy, while the results of electrochemical impedance spectroscopy confirmed the importance of biofilm formation for the corrosion process. The R(QR) equivalent circuit was successfully used to fit the data obtained for the AS mixture without S. mutans, while the R(Q(R(QR))) circuit was found to be more suitable for describing the biofilm properties after treatment with the AS containing S. mutans species. In addition, a negative shift of the open circuit potential with immersion time was observed for all samples regardless of the solution type. Both alloys exhibited higher charge transfer resistance after treatment with Solution 2, and lower corrosion current densities were detected for all samples in the presence of S. mutans. The obtained results suggest that the biofilm formation observed after 24 h of exposure to S. mutans bacteria might enhance the corrosion resistance of the studied samples by creating physical barriers that prevented oxygen interactions with the metal surfaces.

  6. Streptococcus pneumoniae folate biosynthesis responds to environmental CO2 levels.

    PubMed

    Burghout, Peter; Zomer, Aldert; van der Gaast-de Jongh, Christa E; Janssen-Megens, Eva M; Françoijs, Kees-Jan; Stunnenberg, Hendrik G; Hermans, Peter W M

    2013-04-01

    Although carbon dioxide (CO2) is known to be essential for Streptococcus pneumoniae growth, it is poorly understood how this respiratory tract pathogen adapts to the large changes in environmental CO2 levels it encounters during transmission, host colonization, and disease. To identify the molecular mechanisms that facilitate pneumococcal growth under CO2-poor conditions, we generated a random S. pneumoniae R6 mariner transposon mutant library representing mutations in 1,538 different genes and exposed it to CO2-poor ambient air. With Tn-seq, we found mutations in two genes that were involved in S. pneumoniae adaptation to changes in CO2 availability. The gene pca, encoding pneumococcal carbonic anhydrase (PCA), was absolutely essential for S. pneumoniae growth under CO2-poor conditions. PCA catalyzes the reversible hydration of endogenous CO2 to bicarbonate (HCO3(-)) and was previously demonstrated to facilitate HCO3(-)-dependent fatty acid biosynthesis. The gene folC that encodes the dihydrofolate/folylpolyglutamate synthase was required at the initial phase of bacterial growth under CO2-poor culture conditions. FolC compensated for the growth-phase-dependent decrease in S. pneumoniae intracellular long-chain (n > 3) polyglutamyl folate levels, which was most pronounced under CO2-poor growth conditions. In conclusion, S. pneumoniae adaptation to changes in CO2 availability involves the retention of endogenous CO2 and the preservation of intracellular long-chain polyglutamyl folate pools.

  7. Serotype-specific mortality from invasive Streptococcus pneumoniae disease revisited

    PubMed Central

    Martens, Pernille; Worm, Signe Westring; Lundgren, Bettina; Konradsen, Helle Bossen; Benfield, Thomas

    2004-01-01

    Background Invasive infection with Streptococcus pneumoniae (pneumococci) causes significant morbidity and mortality. Case series and experimental data have shown that the capsular serotype is involved in the pathogenesis and a determinant of disease outcome. Methods Retrospective review of 464 cases of invasive disease among adults diagnosed between 1990 and 2001. Multivariate Cox proportional hazard analysis. Results After adjustment for other markers of disease severity, we found that infection with serotype 3 was associated with an increased relative risk (RR) of death of 2.54 (95% confidence interval (CI): 1.22–5.27), whereas infection with serotype 1 was associated with a decreased risk of death (RR 0.23 (95% CI, 0.06–0.97)). Additionally, older age, relative leucopenia and relative hypothermia were independent predictors of mortality. Conclusion Our study shows that capsular serotypes independently influenced the outcome from invasive pneumococcal disease. The limitations of the current polysaccharide pneumococcal vaccine warrant the development of alternative vaccines. We suggest that the virulence of pneumococcal serotypes should be considered in the design of novel vaccines. PMID:15228629

  8. [Contrasting study of erythritol and xylitol on Streptococcus mutans].

    PubMed

    Yao, Jun; Zhang, Jia-Li; Wu, Yu-Qiong; Lu, Zhao-Jie

    2009-12-01

    To study the inhibitory effect of erythritol by contrast to xylitol on growth and acid production of Streptococcus mutans (S. mutans). S. mutans were incubated respectively in 0.5%, 1%, 2%, 4%, 8%, 12%, 16% erythritol or xylitol culture medium under anaerobic conditions. The A and pH value of the mediums were measured at 0, 2, 4, 6, 8, 10, 12, 18, 24 hours, following the profile plots by SPSS. The data of A were higher in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while lower in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. The data of pH were lower in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while higer in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. It indicated that the growth and acid production of S. mutans were higer in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while lower in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. Compared with xylitol, erythritol in low concentration has weaker effort on the growth and acid production of S. mutans, while having stronger effort in high concentration.

  9. Contribution of IL-1 to resistance to Streptococcus pneumoniae infection.

    PubMed

    Kafka, Daniel; Ling, Eduard; Feldman, Galia; Benharroch, Daniel; Voronov, Elena; Givon-Lavi, Noga; Iwakura, Yoichiro; Dagan, Ron; Apte, Ron N; Mizrachi-Nebenzahl, Yaffa

    2008-09-01

    The role of IL-1 in susceptibility to Streptococcus pneumoniae infection was studied in mice deficient in genes of the IL-1 family [i.e. IL-1alpha-/-, IL-1beta-/-, IL-1alpha/beta-/- and IL-1R antagonist (IL-1Ra)-/- mice] following intra-nasal inoculation. Intra-nasal inoculation of S. pneumoniae of IL-1beta-/- and IL-1alpha/beta-/- mice displayed significantly lower survival rates and higher nasopharyngeal and lung bacterial load as compared with control, IL-1alpha-/- and IL-1Ra-/- mice. Treatment of IL-1beta-/- mice with rIL-1beta significantly improved their survival. A significant increase in blood neutrophils was found in control, IL-1alpha-/- and IL-1Ra-/- but not in IL-1beta-/- and IL-1alpha/beta-/- mice. Local infiltrates of neutrophils and relatively preserved organ architecture were observed in the lungs of IL-1alpha-/- and control mice. However, S. pneumoniae-infected IL-1beta-/-, IL-1alpha/beta-/- and IL-1Ra-/- mice demonstrated diffuse pneumonia and tissue damage. Altogether, all three isoforms contribute to protection against S. pneumoniae; our results point to differential role of IL-1alpha and IL-1beta in the pathogenesis and control of S. pneumoniae infection and suggest that IL-1beta has a major role in resistance to primary pneumococcal infection while the role of IL-1alpha is less important.

  10. Recent advances in our understanding of Streptococcus pneumoniae infection

    PubMed Central

    Anderson, Ronald

    2014-01-01

    A number of significant challenges remain with regard to the diagnosis, treatment, and prevention of infections with Streptococcus pneumoniae (pneumococcus), which remains the most common bacterial cause of community-acquired pneumonia. Although this infection is documented to be extremely common in younger children and in older adults, the burden of pneumonia it causes is considerably underestimated, since the incidence statistics are derived largely from bacteremic infections, because they are easy to document, and yet the greater burden of pneumococcal pneumonias is non-invasive. It has been estimated that for every bacteremic pneumonia that is documented, three non-bacteremic infections occur. Management of these infections is potentially complicated by the increasing resistance of the isolates to the commonly used antibiotics. Furthermore, it is well recognized that despite advances in medical care, the mortality of bacteremic pneumococcal pneumonia has remained largely unchanged over the past 50 years and averages approximately 12%. Much recent research interest in the field of pneumococcal infections has focused on important virulence factors of the organism, on improved diagnostic and prognostication tools, on defining risk factors for death, on optimal treatment strategies involving both antibiotics and adjunctive therapies, and on disease prevention. It is hoped that through these endeavors the outlook of pneumococcal infections will be improved. PMID:25343039

  11. Recombinant expression of Streptococcus pneumoniae capsular polysaccharides in Escherichia coli

    PubMed Central

    Kay, Emily J.; Yates, Laura E.; Terra, Vanessa S.; Cuccui, Jon; Wren, Brendan W.

    2016-01-01

    Currently, Streptococcus pneumoniae is responsible for over 14 million cases of pneumonia worldwide annually, and over 1 million deaths, the majority of them children. The major determinant for pathogenesis is a polysaccharide capsule that is variable and is used to distinguish strains based on their serotype. The capsule forms the basis of the pneumococcal polysaccharide vaccine (PPV23) that contains purified capsular polysaccharide from 23 serotypes, and the pneumococcal conjugate vaccine (PCV13), containing 13 common serotypes conjugated to CRM197 (mutant diphtheria toxin). Purified capsule from S. pneumoniae is required for pneumococcal conjugate vaccine production, and costs can be prohibitively high, limiting accessibility of the vaccine in low-income countries. In this study, we demonstrate the recombinant expression of the capsule-encoding locus from four different serotypes of S. pneumoniae within Escherichia coli. Furthermore, we attempt to identify the minimum set of genes necessary to reliably and efficiently express these capsules heterologously. These E. coli strains could be used to produce a supply of S. pneumoniae serotype-specific capsules without the need to culture pathogenic bacteria. Additionally, these strains could be applied to synthetic glycobiological applications: recombinant vaccine production using E. coli outer membrane vesicles or coupling to proteins using protein glycan coupling technology. PMID:27110302

  12. Granzyme A impairs host defense during Streptococcus pneumoniae pneumonia.

    PubMed

    van den Boogaard, Florry E; van Gisbergen, Klaas P J M; Vernooy, Juanita H; Medema, Jan P; Roelofs, Joris J T H; van Zoelen, Marieke A D; Endeman, Henrik; Biesma, Douwe H; Boon, Louis; Van't Veer, Cornelis; de Vos, Alex F; van der Poll, Tom

    2016-08-01

    Streptococcus pneumoniae is the most common causative pathogen in community-acquired pneumonia (CAP). Granzyme A (GzmA) is a serine protease produced by a variety of cell types involved in the immune response. We sought to determine the role of GzmA on the host response during pneumococcal pneumonia. GzmA was measured in bronchoalveolar lavage fluid (BALF) harvested from CAP patients from the infected and contralateral uninfected side and in lung tissue slides from CAP patients and controls. In CAP patients, GzmA levels were increased in BALF obtained from the infected lung. Human lungs showed constitutive GzmA expression by both parenchymal and nonparenchymal cells. In an experimental setting, pneumonia was induced in wild-type (WT) and GzmA-deficient (GzmA(-/-)) mice by intranasal inoculation of S. pneumoniae In separate experiments, WT and GzmA(-/-) mice were treated with natural killer (NK) cell depleting antibodies. Upon infection with S. pneumoniae, GzmA(-/-) mice showed a better survival and lower bacterial counts in BALF and distant body sites compared with WT mice. Although NK cells showed strong GzmA expression, NK cell depletion did not influence bacterial loads in either WT or GzmA(-/-) mice. These results implicate that GzmA plays an unfavorable role in host defense during pneumococcal pneumonia by a mechanism that does not depend on NK cells.

  13. Penicillin resistance and serotyping of Streptococcus pneumoniae in Latin America.

    PubMed

    Camargos, Paulo; Fischer, Gilberto Bueno; Mocelin, Helena; Dias, Cícero; Ruvinsky, Raúl

    2006-09-01

    Streptococcus pneumoniae (Strep. pneumoniae) is the main cause of bacterial pneumonia in children less than 5 years of age, with high mortality rates in developing countries. In 1993, the Regional System for Vaccines Group (SIREVA) of the pan-American Health Organisation (PAHO) began a study involving six Latin American countries to identify serotypes and their representativity in the new conjugated vaccines, and to determine the degree of resistance to penicillin. Serotypes 14 (highest resistance level), 5, 1, 6A/B, 23F, 7F, 9V, 19F, 18C, 19A, 9N, were prevalent in the region, with some differences among countries. Although resistance to penicillin ranged from 2% (Brazil) to 21.1% (Mexico), studies have shown that pneumonia caused by Strep. pneumoniae with diminished sensitivity to penillin can be treated with this antibiotic. Only 58% of the serotypes isolated in the region studied were represented in the seven-valent vaccine. Continual surveillance is essential to determine which formulation of conjugated vaccine will be suitable for use in Latin America.

  14. Molecular Characterization of Invasive Streptococcus dysgalactiae subsp. equisimilis, Japan.

    PubMed

    Wajima, Takeaki; Morozumi, Miyuki; Hanada, Shigeo; Sunaoshi, Katsuhiko; Chiba, Naoko; Iwata, Satoshi; Ubukata, Kimiko

    2016-02-01

    We collected β-hemolytic streptococci (1,611 isolates) from patients with invasive streptococcal infections in Japan during April 2010-March 2013. Streptococcus dysgalactiae subsp. equisimilis (SDSE) was most common (n = 693); 99% of patients with SDSE infections were elderly (mean age 75 years, SD ±15 years). We aimed to clarify molecular and epidemiologic characteristics of SDSE isolates and features of patient infections. Bacteremia with no identified focus of origin and cellulitis were the most prevalent manifestations; otherwise, clinical manifestations resembled those of S. pyogenes infections. Clinical manifestations also differed by patient's age. SDSE isolates were classified into 34 emm types; stG6792 was most prevalent (27.1%), followed by stG485 and stG245. Mortality rates did not differ according to emm types. Multilocus sequence typing identified 46 sequence types and 12 novel types. Types possessing macrolide- and quinolone-resistance genes were 18.4% and 2.6%, respectively; none showed β-lactam resistance. Among aging populations, invasive SDSE infections are an increasing risk.

  15. Expression, purification and crystallization of Streptococcus dysgalactiae-derived mitogen

    SciTech Connect

    Papageorgiou, Anastassios C. Saarinen, Susanna; Ramirez-Bartutis, Rosa; Kato, Hidehito; Uchiyama, Takehiko; Kirikae, Teruo; Miyoshi-Akiyama, Toru

    2006-03-01

    S. dysgalactiae-derived mitogen, a superantigen, was crystallized. Crystals diffract to 2.4 Å at a synchrotron-radiation source and belong to space group P3/P3{sub 1}/P3{sub 2}, with unit-cell parameters a = b = 52.7, c = 62.4 Å, γ = 120° and one molecule in the crystallographic asymmetric unit. Superantigens are bacterial or viral toxins with potent immunostimulatory properties. Streptococcus dysgalactiae-derived mitogen, a 25 kDa protein, is a recently discovered superantigen isolated from S. dysgalactiae culture supernatant. Sequence considerations suggest that it belongs to a new superantigen family distinct from other superantigens. The protein was expressed in Escherichia coli cells and purified to homogeneity. Crystals were grown at pH 4.2–4.4 in the presence of 18–20%(w/v) PEG 3350 and 0.4 M lithium nitrate. A complete data set to 2.4 Å resolution was collected from a single crystal at liquid-nitrogen temperatures using synchrotron radiation. The crystals belong to space group P3/P3{sub 1}/P3{sub 2}, with unit-cell parameters a = b = 52.7, c = 62.4 Å, γ = 120° and one molecule in the crystallographic asymmetric unit.

  16. Streptococcal toxic shock syndrome secondary to group A Streptococcus vaginitis.

    PubMed

    Hikone, Mayu; Kobayashi, Ken-Ichiro; Washino, Takuya; Ota, Masayuki; Sakamoto, Naoya; Iwabuchi, Sentaro; Ohnishi, Kenji

    2015-12-01

    Streptococcal toxic shock syndrome (TSS) is a systemic illness usually caused in the setting of infection by group A Streptococcus (GAS). The primary infections are often invasive infections of the respiratory tract or necrotizing infections of the skin and soft tissue, but some infections occur without relevant focus. GAS vaginitis is a rare condition among adult women and is accordingly thought to be uncommon as a cause of streptococcal TSS. Here we report the cases of two postmenopausal women with streptococcal TSS secondary to GAS vaginitis, one aged 55 and one aged 60. Both came to our emergency department with complaints or symptoms of abdominal pain, fever, hypotension, and multi-organ failure. In both cases, the relevant factor associated with streptococcal infection was a recent episode of GAS vaginitis. Both underwent fluid management and 14 days of antibiotic treatment and fully recovered without complications. Vaginitis was likely to be the primary infectious trigger of TSS in these two cases. Intrauterine device insertion, endometrial biopsy, and post-partum state have all been previously reported in TSS patients, and the female genital tract has been described as a portal of entry. GAS vaginitis warrants appropriate treatment as it may progress to severe systemic infection as described. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  17. β-Phosphoglucomutase contributes to aciduricity in Streptococcus mutans

    PubMed Central

    Buckley, Andrew A.; Faustoferri, Roberta C.

    2014-01-01

    Streptococcus mutans encounters an array of sugar moieties within the oral cavity due to a varied human diet. One such sugar is β-d-glucose 1-phosphate (βDG1P), which must be converted to glucose 6-phosphate (G6P) before further metabolism to lactic acid. The conversion of βDG1P to G6P is mediated by β-phosphoglucomutase, which has not been previously observed in any oral streptococci, but has been extensively characterized and the gene designated pgmB in Lactococcus lactis. An orthologue was identified in S. mutans, SMU.1747c, and deletion of the gene resulted in the inability of the deletion strain to convert βDG1P to G6P, indicating that SMU.1747c is a β-phosphoglucomutase and should be designated pgmB. In this study, we sought to characterize how deletion of pgmB affected known virulence factors of S. mutans, specifically acid tolerance. The ΔpgmB strain showed a decreased ability to survive acid challenge. Additionally, the strain lacking β-phosphoglucomutase had a diminished glycolytic profile compared with the parental strain. Deletion of pgmB had a negative impact on the virulence of S. mutans in the Galleria mellonella (greater wax worm) animal model. Our results indicate that pgmB plays a role at the juncture of carbohydrate metabolism and virulence. PMID:24509501

  18. Adaptation of Group A Streptococcus to Human Amniotic Fluid

    PubMed Central

    Sitkiewicz, Izabela; Green, Nicole M.; Guo, Nina; Bongiovanni, Ann M.; Witkin, Steven S.; Musser, James M.

    2010-01-01

    Background For more than 100 years, group A Streptococcus has been identified as a cause of severe and, in many cases, fatal infections of the female urogenital tract. Due to advances in hospital hygiene and the advent of antibiotics, this type of infection has been virtually eradicated. However, within the last three decades there has been an increase in severe intra- and post-partum infections attributed to GAS. Methodology We hypothesized that GAS alters its transcriptome to survive in human amniotic fluid (AF) and cause disease. To identify genes that were up or down regulated in response to growth in AF, GAS was grown in human AF or standard laboratory media (THY) and samples for expression microarray analysis were collected during mid-logarithmic, late-logarithmic, and stationary growth phases. Microarray analysis was performed using a custom Affymetrix chip and normalized hybridization values derived from three biological replicates were collected at each growth point. Ratios of AF/THY above a 2-fold change and P-value <0.05 were considered significant. Principal Findings The majority of changes in the GAS transcriptome involved down regulation of multiple adhesins and virulence factors and activation of the stress response. We observed significant changes in genes involved in the arginine deiminase pathway and in the nucleotide de novo synthesis pathway. Conclusions/Significance Our work provides new insight into how pathogenic bacteria respond to their environment to establish infection and cause disease. PMID:20352104

  19. Nicotine Enhances Interspecies Relationship between Streptococcus mutans and Candida albicans.

    PubMed

    Liu, Shiyu; Qiu, Wei; Zhang, Keke; Zhou, Xuedong; Ren, Biao; He, Jinzhi; Xu, Xin; Cheng, Lei; Li, Mingyun

    2017-01-01

    Streptococcus mutans and Candida albicans are common microorganisms in the human oral cavity. The synergistic relationship between these two species has been deeply explored in many studies. In the present study, the effect of alkaloid nicotine on the interspecies between S. mutans and C. albicans is explored. We developed a dual-species biofilm model and studied biofilm biomass, biofilm structure, synthesis of extracellular polysaccharides (EPS), and expression of glucosyltransferases (Gtfs). Biofilm formation and bacterial and fungal cell numbers in dual-species biofilms increased in the presence of nicotine. More C. albicans cells were present in the dual-species biofilms in the nicotine-treated groups as determined by scanning electron microscopy. The synthesis of EPS was increased by 1 mg/ml of nicotine as detected by confocal laser scanning microscopy. The result of qRT-PCR showed gtfs expression was upregulated when 1 mg/ml of nicotine was used. We speculate that nicotine promoted the growth of S. mutans, and more S. mutans cells attracted more C. albicans cells due to the interaction between two species. Since S. mutans and C. albicans are putative pathogens for dental caries, the enhancement of the synergistic relationship by nicotine may contribute to caries development in smokers.

  20. Effect of nicotine on cariogenic virulence of Streptococcus mutans.

    PubMed

    Li, Mingyun; Huang, Ruijie; Zhou, Xuedong; Qiu, Wei; Xu, Xin; Gregory, Richard L

    2016-11-01

    Nicotine has well-documented effects on the growth and colonization of Streptococcus mutans. This study attempts to investigate the effects of nicotine on pathogenic factors of S. mutans, such as the effect on biofilm formation and viability, expression of pathogenic genes, and metabolites of S. mutans. The results demonstrated that addition of nicotine did not significantly influence the viability of S. mutans cells. The biofilms became increasingly compact as the concentrations of nicotine increased. The expression of virulence genes, such as ldh and phosphotransferase system (PTS)-associated genes, was upregulated, and nlmC was upregulated significantly, while ftf was downregulated. The lactate concentration of S. mutans grown in 1 mg/mL of nicotine was increased up to twofold over either biofilm or planktonic cells grown without nicotine. Changes in the metabolites involved in central carbon metabolism from sucrose indicated that most selected metabolites were detectable and influenced by increased concentrations of nicotine. This study demonstrated that nicotine can influence the pathogenicity of S. mutans and may lead to increased dental caries through the production of more lactate and the upregulation of virulence genes.

  1. Structural basis of hyaluronan degradation by Streptococcus pneumoniae hyaluronate lyase

    PubMed Central

    Li, Songlin; Kelly, Stephen J.; Lamani, Ejvis; Ferraroni, Marta; Jedrzejas, Mark J.

    2000-01-01

    Streptococcus pneumoniae hyaluronate lyase (spnHL) is a pathogenic bacterial spreading factor and cleaves hyaluronan, an important constituent of the extra– cellular matrix of connective tissues, through an enzymatic β–elimination process, different from the hyaluronan degradation by hydrolases in animals. The mechanism of hyaluronan binding and degradation was proposed based on the 1.56 Å resolution crystal structure, substrate modeling and mutagenesis studies on spnHL. Five mutants, R243V, N349A, H399A, Y408F and N580G, were constructed and their activities confirmed our mechanism hypothesis. The important roles of Tyr408, Asn349 and His399 in enzyme catalysis were proposed, explained and confirmed by mutant studies. The remaining weak enzymatic activity of the H399A mutant, the role of the free carboxylate group on the glucuronate residue, the enzymatic behavior on chondroitin and chondroitin sulfate, and the small activity increase in the N580G mutant were explained based on this mechanism. A possible function of the C–terminal β–sheet domain is to modulate enzyme activity through binding to calcium ions. PMID:10716923

  2. Molecular epidemiology of Streptococcus agalactiae recovered from significant bacteriuria.

    PubMed

    Schuab, Rôde B B; Arêas, Glauber P; Souza, Viviane C; Barros, Rosana R

    2015-09-01

    Streptococcus agalactiae has been implicated in urinary tract infections, but the molecular epidemiology of such infections is poorly characterized. In this study, 194 isolates recovered from significant bacteriuria of non-pregnant individuals were submitted to antimicrobial susceptibility testing, molecular characterization of macrolide resistance, PCR-based capsular typing and analysis of genetic diversity by pulsed-field gel electrophoresis (PFGE). By disk diffusion, all isolates were susceptible to ceftriaxone, levofloxacin, penicillin G and vancomycin; 87.6% and 9.3% of isolates were non-susceptible to tetracycline and clindamycin, respectively. The minimum inhibitory concentration (MIC) confirmed that 11.3% of isolates were resistant to erythromycin. Macrolide resistance determinants were iMLSB (n = 9), cMLSB (n = 9) and M (n = 4), associated with ermA, ermB and mefA/E. Predominant capsular types were V, Ia, II and III. No significant association was observed between any capsular type and the occurrence of pyuria. However, type III was associated with erythromycin resistance, while type II was associated with erythromycin-susceptible isolates. Distinct PFGE profiles were observed among different types, but identical profiles were found among erythromycin-susceptible and -resistant isolates of the same type. A variety of capsular and PFGE types are involved in significant bacteriuria. Although capsular types found here are prevalent in different infections, the frequency of each type seems to be unique. Erythromycin resistance is due to polyclonal origin instead of the expansion of few clones of S. agalactiae.

  3. A case of multiple empyema caused by Streptococcus intermedius.

    PubMed

    Kaga, Akihito; Higo, Ryuzaburo; Yoshikawa, Hiroshi; Yokoi, Naoko; Haruyama, Takuo; Komatsu, Hiroaki; Yabe, Ayumi; Kusunoki, Takeshi; Ikeda, Katsuhisa

    2016-11-29

    We report the case of a patient with multiple empyema present throughout his body, including chronic sinusitis and chronic suppurative otitis media, as well as subsequent epidural empyema, all caused by Streptococcus intermedius. A 38-year-old man presented with chief complaints of headache, left ear discharge, and nasal congestion. Imaging studies revealed pansinusitis, soft tissue signs in the mastoid cells, and otitis media. The patient was treated with meropenem hydrate, 6g/day. While clinical findings indicated improvement of the sinusitis, his headache did not improve. Further examination with contrast computerized tomography (CT) 'a chest radiography' blood cultures were performed, and the patient was diagnosed with multiple empyema (with an epidural empyema, pulmonary suppuration) caused by S. intermedius. Subsequent burr hole drainage was implemented to drain the epidural empyema. Long-term administration was required to treat pulmonary suppuration. While they remain rare, there has been a recent upward trend in the frequency of cases in which a young, previously healthy patient has developed multiple empyema throughout their body despite the absence of complicating diseases that pose an immune deficiency risk, such as diabetes or infection with the human immunodeficiency virus (HIV). In order to properly diagnose and treat patients presenting with multiple empyema infection with S. intermedius should be included in the differential diagnosis.

  4. Nicotine Enhances Interspecies Relationship between Streptococcus mutans and Candida albicans

    PubMed Central

    Qiu, Wei; Zhang, Keke; Zhou, Xuedong; Ren, Biao; He, Jinzhi; Xu, Xin

    2017-01-01

    Streptococcus mutans and Candida albicans are common microorganisms in the human oral cavity. The synergistic relationship between these two species has been deeply explored in many studies. In the present study, the effect of alkaloid nicotine on the interspecies between S. mutans and C. albicans is explored. We developed a dual-species biofilm model and studied biofilm biomass, biofilm structure, synthesis of extracellular polysaccharides (EPS), and expression of glucosyltransferases (Gtfs). Biofilm formation and bacterial and fungal cell numbers in dual-species biofilms increased in the presence of nicotine. More C. albicans cells were present in the dual-species biofilms in the nicotine-treated groups as determined by scanning electron microscopy. The synthesis of EPS was increased by 1 mg/ml of nicotine as detected by confocal laser scanning microscopy. The result of qRT-PCR showed gtfs expression was upregulated when 1 mg/ml of nicotine was used. We speculate that nicotine promoted the growth of S. mutans, and more S. mutans cells attracted more C. albicans cells due to the interaction between two species. Since S. mutans and C. albicans are putative pathogens for dental caries, the enhancement of the synergistic relationship by nicotine may contribute to caries development in smokers. PMID:28280743

  5. HIV Infection Affects Streptococcus mutans Levels, but Not Genotypes

    PubMed Central

    Liu, G.; Saxena, D.; Chen, Z.; Norman, R.G.; Phelan, J.A.; Laverty, M.; Fisch, G.S.; Corby, P.M.; Abrams, W.; Malamud, D.; Li, Y.

    2012-01-01

    We report a clinical study that examines whether HIV infection affects Streptococcus mutans colonization in the oral cavity. Whole stimulated saliva samples were collected from 46 HIV-seropositive individuals and 69 HIV-seronegative control individuals. The level of S. mutans colonization was determined by conventional culture methods. The genotype of S. mutans was compared between 10 HIV-positive individuals before and after highly active antiretroviral therapy (HAART) and 10 non-HIV-infected control individuals. The results were analyzed against viral load, CD4+ and CD8+ T-cell counts, salivary flow rate, and caries status. We observed that S. mutans levels were higher in HIV-infected individuals than in the non-HIV-infected control individuals (p = 0.013). No significant differences in S. mutans genotypes were found between the two groups over the six-month study period, even after HAART. There was a bivariate linear relationship between S. mutans levels and CD8+ counts (r = 0.412; p = 0.007), but not between S. mutans levels and either CD4+ counts or viral load. Furthermore, compared with non-HIV-infected control individuals, HIV-infected individuals experienced lower salivary secretion (p = 0.009) and a positive trend toward more decayed tooth surfaces (p = 0.027). These findings suggest that HIV infection can have a significant effect on the level of S. mutans, but not genotypes. PMID:22821240

  6. Kinetics of Coinfection with Influenza A Virus and Streptococcus pneumoniae

    DOE PAGES

    Smith, Amber M.; Adler, Frederick R.; Ribeiro, Ruy M.; ...

    2013-03-21

    Secondary bacterial infections are a leading cause of illness and death during epidemic and pandemic influenza. Experimental studies suggest a lethal synergism between influenza and certain bacteria, particularly Streptococcus pneumoniae, but the precise processes involved are unclear. In this paper, to address the mechanisms and determine the influences of pathogen dose and strain on disease, we infected groups of mice with either the H1N1 subtype influenza A virus A/Puerto Rico/8/34 (PR8) or a version expressing the 1918 PB1-F2 protein (PR8-PB1-F2(1918)), followed seven days later with one of two S. pneumoniae strains, type 2 D39 or type 3 A66.1. We determinedmore » that, following bacterial infection, viral titers initially rebound and then decline slowly. Bacterial titers rapidly rise to high levels and remain elevated. We used a kinetic model to explore the coupled interactions and study the dominant controlling mechanisms. We hypothesize that viral titers rebound in the presence of bacteria due to enhanced viral release from infected cells, and that bacterial titers increase due to alveolar macrophage impairment. Dynamics are affected by initial bacterial dose but not by the expression of the influenza 1918 PB1-F2 protein. Finally, our model provides a framework to investigate pathogen interaction during coinfections and to uncover dynamical differences based on inoculum size and strain.« less

  7. Metabolic Engineering of Acetaldehyde Production by Streptococcus thermophilus

    PubMed Central

    Chaves, A. C. S. D.; Fernandez, M.; Lerayer, A. L. S.; Mierau, I.; Kleerebezem, M.; Hugenholtz, J.

    2002-01-01

    The process of acetaldehyde formation by the yogurt bacterium Streptococcus thermophilus is described in this paper. Attention was focused on one specific reaction for acetaldehyde formation catalyzed by serine hydroxymethyltransferase (SHMT), encoded by the glyA gene. In S. thermophilus, SHMT also possesses threonine aldolase (TA) activity, the interconversion of threonine into glycine and acetaldehyde. In this work, several wild-type S. thermophilus strains were screened for acetaldehyde production in the presence and absence of l-threonine. Supplementation of the growth medium with l-threonine led to an increase in acetaldehyde production. Furthermore, acetaldehyde formation during fermentation could be correlated to the TA activity of SHMT. To study the physiological role of SHMT, a glyA mutant was constructed by gene disruption. Inactivation of glyA resulted in a severe reduction in TA activity and complete loss of acetaldehyde formation during fermentation. Subsequently, an S. thermophilus strain was constructed in which the glyA gene was cloned under the control of a strong promoter (PLacA). When this strain was used for fermentation, an increase in TA activity and in acetaldehyde and folic acid production was observed. These results show that, in S. thermophilus, SHMT, displaying TA activity, constitutes the main pathway for acetaldehyde formation under our experimental conditions. These findings can be used to control and improve acetaldehyde production in fermented (dairy) products with S. thermophilus as starter culture. PMID:12406762

  8. Group B Streptococcus pili mediate adherence to salivary glycoproteins.

    PubMed

    Brittan, Jane L; Nobbs, Angela H

    2015-05-01

    Group B Streptococcus (GBS) is a leading cause of neonatal sepsis, pneumonia and meningitis, and is responsible for a rising number of severe invasive infections in adults. For all disease manifestations, colonisation is a critical first step. GBS has frequently been isolated from the oropharynx of neonates and adults. However, little is understood about the mechanisms of GBS colonisation at this site. In this study it is shown that three GBS strains (COH1, NEM316, 515) have capacity to adhere to human salivary pellicle. Heterologous expression of GBS pilus island (PI) genes in Lactococcus lactis to form surface-expressed pili demonstrated that GBS PI-2a and PI-1 pili bound glycoprotein-340 (gp340), a component of salivary pellicle. By contrast, PI-2b pili did not interact with gp340. The variation was attributable to differences in capacities for backbone and ancillary protein subunits of each pilus to bind gp340. Furthermore, while GBS strains were aggregated by fluid-phase gp340, this mechanism was not mediated by pili, which displayed specificity for immobilised gp340. Thus pili may enable GBS to colonise the soft and hard tissues of the oropharynx, while evading an innate mucosal defence, with implications for risk of progression to severe diseases such as meningitis and sepsis. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  9. β-Phosphoglucomutase contributes to aciduricity in Streptococcus mutans.

    PubMed

    Buckley, Andrew A; Faustoferri, Roberta C; Quivey, Robert G

    2014-04-01

    Streptococcus mutans encounters an array of sugar moieties within the oral cavity due to a varied human diet. One such sugar is β-d-glucose 1-phosphate (βDG1P), which must be converted to glucose 6-phosphate (G6P) before further metabolism to lactic acid. The conversion of βDG1P to G6P is mediated by β-phosphoglucomutase, which has not been previously observed in any oral streptococci, but has been extensively characterized and the gene designated pgmB in Lactococcus lactis. An orthologue was identified in S. mutans, SMU.1747c, and deletion of the gene resulted in the inability of the deletion strain to convert βDG1P to G6P, indicating that SMU.1747c is a β-phosphoglucomutase and should be designated pgmB. In this study, we sought to characterize how deletion of pgmB affected known virulence factors of S. mutans, specifically acid tolerance. The ΔpgmB strain showed a decreased ability to survive acid challenge. Additionally, the strain lacking β-phosphoglucomutase had a diminished glycolytic profile compared with the parental strain. Deletion of pgmB had a negative impact on the virulence of S. mutans in the Galleria mellonella (greater wax worm) animal model. Our results indicate that pgmB plays a role at the juncture of carbohydrate metabolism and virulence.

  10. Invasive Group A Streptococcus Infection among Children, Rural Kenya.

    PubMed

    Seale, Anna C; Davies, Mark R; Anampiu, Kirimi; Morpeth, Susan C; Nyongesa, Sammy; Mwarumba, Salim; Smeesters, Pierre R; Efstratiou, Androulla; Karugutu, Rosylene; Mturi, Neema; Williams, Thomas N; Scott, J Anthony G; Kariuki, Samuel; Dougan, Gordon; Berkley, James A

    2016-02-01

    To determine the extent of group A Streptococcus (GAS) infections in sub-Saharan Africa and the serotypes that cause disease, we analyzed surveillance data for 64,741 hospital admissions in Kilifi, Kenya, during 1998-2011. We evaluated incidence, clinical presentations, and emm types that cause invasive GAS infection. We detected 370 cases; of the 369 for which we had data, most were skin and soft tissue infections (70%), severe pneumonia (23%), and primary bacteremia (14%). Overall case-fatality risk was 12%. Incidence of invasive GAS infection was 0.6 cases/1,000 live births among neonates, 101/100,000 person-years among children <1 year of age, and 35/100,000 among children <5 years of age. Genome sequencing identified 88 emm types. GAS causes serious disease in children in rural Kenya, especially neonates, and the causative organisms have considerable genotypic diversity. Benefit from the most advanced GAS type-specific vaccines may be limited, and efforts must be directed to protect against disease in regions of high incidence.

  11. Severe Streptococcus pyogenes Infections, United Kingdom, 2003–2004

    PubMed Central

    Neal, Shona; Keshishian, Catherine; Alhaddad, Neelam; George, Robert; Duckworth, Georgia; Vuopio-Varkila, Jaana; Efstratiou, Androulla

    2008-01-01

    As part of a Europe-wide initiative to explore current epidemiologic patterns of severe disease caused by Streptococcus pyogenes, the United Kingdom undertook enhanced population-based surveillance during 2003–2004. A total of 3,775 confirmed cases of severe S. pyogenes infection were identified over 2 years, 3.33/100,000 population, substantially more than previously estimated. Skin/soft tissue infections were the most common manifestation (42%), followed by respiratory tract infections (17%). Injection drug use was identified as a risk factor for 20% of case-patients. One in 5 infected case-patients died within 7 days of diagnosis; the highest mortality rate was for cases of necrotizing fasciitis (34%). Nonsteroidal antiinflammatory drugs, alcoholism, young age, and infection with emm/M3 types were independently associated with increased risk for streptococcal toxic shock syndrome. Understanding the pattern of these diseases and predictors of poor patient outcome will help with identification and assessment of the potential effect of targeted interventions. PMID:18258111

  12. Severe Streptococcus pyogenes infections, United Kingdom, 2003-2004.

    PubMed

    Lamagni, Theresa L; Neal, Shona; Keshishian, Catherine; Alhaddad, Neelam; George, Robert; Duckworth, Georgia; Vuopio-Varkila, Jaana; Efstratiou, Androulla

    2008-02-01

    As part of a Europe-wide initiative to explore current epidemiologic patterns of severe disease caused by Streptococcus pyogenes, the United Kingdom undertook enhanced population-based surveillance during 2003-2004. A total of 3,775 confirmed cases of severe S. pyogenes infection were identified over 2 years, 3.33/100,000 population, substantially more than previously estimated. Skin/soft tissue infections were the most common manifestation (42%), followed by respiratory tract infections (17%). Injection drug use was identified as a risk factor for 20% of case-patients. One in 5 infected case-patients died within 7 days of diagnosis; the highest mortality rate was for cases of necrotizing fasciitis (34%). Nonsteroidal antiinflammatory drugs, alcoholism, young age, and infection with emm/M3 types were independently associated with increased risk for streptococcal toxic shock syndrome. Understanding the pattern of these diseases and predictors of poor patient outcome will help with identification and assessment of the potential effect of targeted interventions.

  13. Epidemiology of severe Streptococcus pyogenes disease in Europe.

    PubMed

    Lamagni, Theresa L; Darenberg, Jessica; Luca-Harari, Bogdan; Siljander, Tuula; Efstratiou, Androulla; Henriques-Normark, Birgitta; Vuopio-Varkila, Jaana; Bouvet, Anne; Creti, Roberta; Ekelund, Kim; Koliou, Maria; Reinert, Ralf René; Stathi, Angeliki; Strakova, Lenka; Ungureanu, Vasilica; Schalén, Claes; Jasir, Aftab

    2008-07-01

    The past 2 decades have brought worrying increases in severe Streptococcus pyogenes diseases globally. To investigate and compare the epidemiological patterns of these diseases within Europe, data were collected through a European Union FP-5-funded program (Strep-EURO). Prospective population-based surveillance of severe S. pyogenes infection diagnosed during 2003 and 2004 was undertaken in 11 countries across Europe (Cyprus, the Czech Republic, Denmark, Finland, France, Germany, Greece, Italy, Romania, Sweden, and the United Kingdom) using a standardized case definition. A total of 5,522 cases were identified across the 11 countries during this period. Rates of reported infection varied, reaching 3/100,000 population in the northern European countries. Seasonal patterns of infection showed remarkable congruence between countries. The risk of infection was highest among the elderly, and rates were higher in males than in females in most countries. Skin lesions/wounds were the most common predisposing factor, reported in 25% of cases; 21% had no predisposing factors reported. Skin and soft tissue were the most common foci of infection, with 32% of patients having cellulitis and 8% necrotizing fasciitis. The overall 7-day case fatality rate was 19%; it was 44% among patients who developed streptococcal toxic shock syndrome. The findings from Strep-EURO confirm a high incidence of severe S. pyogenes disease in Europe. Furthermore, these results have identified targets for public health intervention, as well as raising awareness of severe S. pyogenes disease across Europe.

  14. Pleiotropic virulence factor - Streptococcus pyogenes fibronectin-binding proteins.

    PubMed

    Yamaguchi, Masaya; Terao, Yutaka; Kawabata, Shigetada

    2013-04-01

    Streptococcus pyogenes causes a broad spectrum of infectious diseases, including pharyngitis, skin infections and invasive necrotizing fasciitis. The initial phase of infection involves colonization, followed by intimate contact with the host cells, thus promoting bacterial uptake by them. S. pyogenes recognizes fibronectin (Fn) through its own Fn-binding proteins to obtain access to epithelial and endothelial cells in host tissue. Fn-binding proteins bind to Fn to form a bridge to α5 β1 -integrins, which leads to rearrangement of cytoskeletal actin in host cells and uptake of invading S. pyogenes. Recently, several structural analyses of the invasion mechanism showed molecular interactions by which Fn converts from a compact plasma protein to a fibrillar component of the extracellular matrix. After colonization, S. pyogenes must evade the host innate immune system to spread into blood vessels and deeper organs. Some Fn-binding proteins contribute to evasion of host innate immunity, such as the complement system and phagocytosis. In addition, Fn-binding proteins have received focus as non-M protein vaccine candidates, because of their localization and conservation among different M serotypes.Here, we review the roles of Fn-binding proteins in the pathogenesis and speculate regarding possible vaccine antigen candidates. © 2012 Blackwell Publishing Ltd.

  15. Streptococcus pyogenes biofilms-formation, biology, and clinical relevance.

    PubMed

    Fiedler, Tomas; Köller, Thomas; Kreikemeyer, Bernd

    2015-01-01

    Streptococcus pyogenes (group A streptococci, GAS) is an exclusive human bacterial pathogen. The virulence potential of this species is tremendous. Interactions with humans range from asymptomatic carriage over mild and superficial infections of skin and mucosal membranes up to systemic purulent toxic-invasive disease manifestations. Particularly the latter are a severe threat for predisposed patients and lead to significant death tolls worldwide. This places GAS among the most important Gram-positive bacterial pathogens. Many recent reviews have highlighted the GAS repertoire of virulence factors, regulators and regulatory circuits/networks that enable GAS to colonize the host and to deal with all levels of the host immune defense. This covers in vitro and in vivo studies, including animal infection studies based on mice and more relevant, macaque monkeys. It is now appreciated that GAS, like many other bacterial species, do not necessarily exclusively live in a planktonic lifestyle. GAS is capable of microcolony and biofilm formation on host cells and tissues. We are now beginning to understand that this feature significantly contributes to GAS pathogenesis. In this review we will discuss the current knowledge on GAS biofilm formation, the biofilm-phenotype associated virulence factors, regulatory aspects of biofilm formation, the clinical relevance, and finally contemporary treatment regimens and future treatment options.

  16. Evidence for a disseminated plasmid in Streptococcus mutans.

    PubMed Central

    Macrina, F L; Scott, C L

    1978-01-01

    Based on a survey of 86 isolates, approximately 5% of all naturally occurring strains of Streptococcus mutans contains a 3.6 X 10(6)-dalton (3.6-megadalton) multicopy plasmid of unknown function. The amount of plasmid deoxyribonucleic acid per chromosome varies from 2 to 6% depending on the host strain. About 13% of the total covalently closed circular deoxyribonucleic acid in each of the four plasmid-containing strains consists of dimeric molecules, with interlocked circular forms predominating. Site-specific restriction endonucleases have been identified that cleave this 3.6-megadalton plasmid at single and at multiple sites. Each of the four plasmids is cleaved once by the HindIII and BamHI restriction enzymes. The HpaI, TaqI, and HhaI enzymes generate two, five, and six components, respectively, and the digestion products of each of the four plasmids are identical. Because the four plasmid-containing S. mutans strains are physiologically unique with respect to one another, we conclude this plasmid to be a disseminated extrachromosomal element in S. mutans. Images PMID:669797

  17. Streptococcus pyogenes bacteraemia, emm types and superantigen profiles.

    PubMed

    Rantala, S; Vähäkuopus, S; Siljander, T; Vuopio, J; Huhtala, H; Vuento, R; Syrjänen, J

    2012-05-01

    The aim of this study was to investigate the emm types and superantigen profiles of bacteraemic group A streptococcal (GAS; Streptococcus pyogenes) isolates and to detect possible associations between the molecular characteristics of isolates and the clinical presentations of disease. In this population-based study, 87 bacteraemic GAS isolates from adult patients in Pirkanmaa Health District (HD), Finland, during the period 1995-2004 were emm typed and genotyped for superantigen (SAg) profiles. The epidemiological and clinical data of the patients were analysed with the microbiological characterisation data. Among the 87 isolates, 18 different emm types were found. emm1, emm28 and emm81 were the three most common types, covering 52% of isolates. The prevalence of specific emm types showed high variability during the 10-year study period. We could not find any association between the emm type and clinical features of bacteraemic infection, such as underlying diseases, disease manifestations or case fatality. Of nine superantigen genes examined, speA and speC were identified in 20 and 30% of the strains, respectively. No association was found between disease manifestation and the presence of single superantigen genes. The 26-valent GAS vaccine would have covered only 62% of isolates causing invasive disease in Pirkanmaa HD during the study period.

  18. Mucosal vaccination promotes clearance of Streptococcus agalactiae vaginal colonization.

    PubMed

    Baker, Jacqueline A; Lewis, Emma L; Byland, Leah M; Bonakdar, Maryam; Randis, Tara M; Ratner, Adam J

    2017-03-01

    Group B Streptococcus (GBS) is a leading cause of morbidity and mortality in infants, and colonization of the maternal genital tract is the primary risk factor for newborn infection. Despite the importance of mucosal colonization in GBS pathogenesis, relevant host and bacterial factors are incompletely understood. We investigated the role of humoral immunity in clearance of vaginal colonization in vivo. B-cell-deficient mice or those lacking neonatal Fc-receptor, a mediator of IgG transport to the vaginal mucosa, exhibit prolonged GBS vaginal colonization compared to wild type animals. Intranasal but not intramuscular immunization induced systemic and mucosal immune responses and decreased GBS colonization duration without altering initial colonization density. Vaccine-induced clearance of GBS was serotype-specific, suggesting a role for anti-capsule antibodies in protection. Our results support a role for humoral immunity in GBS eradication from the female genital tract and suggest that mucosal vaccination may prime colonization clearance. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  19. Extracellular Transglucosylase and α-Amylase of Streptococcus equinus1

    PubMed Central

    Boyer, Ernest W.; Hartman, Paul A.

    1971-01-01

    Culture filtrates of Streptococcus equinus 1091 contained α-amylase and transglucosylase. The effects of calcium carbonate, age of inoculum, concentration of maltose, and duration of the fermentation on α-amylase and transglucosylase production were determined. The extracellular α-amylase was purified 48-fold and was free of transglucosylase activity. The α-amylase (amylose substrate) required Cl− for maximum activity; ethylenediaminetetraacetic acid (EDTA) partially inhibited activity, but CaCl2 prevented EDTA inhibition. The temperature optimum was 38 C at pH 7.0, and the pH optimum was 7.0 at 37 C in the presence of CaCl2. Predominant final products of amylose hydrolysis, in order of decreasing prevalence, were maltose, maltotriose, maltotetraose, and glucose. The α-amylase showed no evidence of multiple attack. The extracellular transglucosylase was purified 27-fold, but a small amount of α-amylase remained. Transglucosylase activity (amylose substrate) was not increased in the presence of CaCl2. The temperature optimum was 37 C at pH 6.5, and the pH optimum was 6.0 at 37 C. Carbohydrates that served as acceptors for the transglucosylase to degrade amylose were, in order of decreasing acceptor efficiency: d-glucose, d-mannose, l-sorbose, maltose, sucrose, and trehalose. The extracellular transglucosylase of S. equinus 1091 synthesized higher maltodextrins in the medium when the cells were grown in the presence of maltose. Images PMID:4995651

  20. Genomic analysis and reconstruction of cefotaxime resistance in Streptococcus pneumoniae.

    PubMed

    Fani, Fereshteh; Brotherton, Marie-Christine; Leprohon, Philippe; Ouellette, Marc

    2013-08-01

    To identify non-penicillin-binding protein (PBP) mutations contributing to resistance to the third-generation cephalosporin cefotaxime in Streptococcus pneumoniae at the genome-wide scale. The genomes of two in vitro S. pneumoniae cefotaxime-resistant isolates and of two transformants serially transformed with the genomic DNA of cefotaxime-resistant mutants were determined by next-generation sequencing. A role in cefotaxime resistance for the mutations identified was confirmed by reconstructing resistance in a cefotaxime-susceptible background. Analysis of the genome assemblies revealed mutations in genes coding for the PBPs 2x, 2a and 3, of which pbp2x was the only mutated gene common to all mutants. The transformation of altered PBP alleles into S. pneumoniae R6 confirmed the role of PBP mutations in cefotaxime resistance, but these were not sufficient to fully explain the levels of resistance. Thirty-one additional genes were found to be mutated in at least one of the four sequenced genomes. Non-PBP resistance determinants appeared to be mostly lineage specific. Mutations in spr1333, spr0981, spr1704 and spr1098, encoding a peptidoglycan N-acetylglucosamine deacetylase, a glycosyltransferase, an ABC transporter and a sortase, respectively, were implicated in resistance by transformation experiments and allowed the reconstruction of the full level of resistance observed in the parent resistant strains. This whole-genome analysis coupled to functional studies has allowed the discovery of both known and novel cefotaxime resistance genes in S. pneumoniae.

  1. Immune Response to Invasive Group B Streptococcus Disease in Adults

    PubMed Central

    Rench, Marcia A.; Rinaudo, C. Daniela; Fabbrini, Monica; Tuscano, Giovanna; Buffi, Giada; Bartolini, Erika; Bonacci, Stefano; Baker, Carol J.; Margarit, Immaculada

    2016-01-01

    Immunization of nonpregnant adults could help prevent invasive group B Streptococcus (GBS) infections, but adult immune responses have not been investigated. We defined capsular polysaccharide (CPS) and pilus island (PI) surface antigen distribution and expression and immune responses to GBS infection in nonpregnant adults. Prospective surveillance from 7 hospitals in Houston, Texas, USA, identified 102 adults with GBS bacteremia; 43% had skin/soft tissue infection, 16% bacteremia without focus, and 12% osteomyelitis. CPS-specific IgG was determined by ELISA and pilus-specific IgG by multiplex immunoassay. CPS types were Ia (24.5%), Ib (12.7%), II (9.8%), III (16.7%), IV (13.7%), and V (12.7%); 9.8% were nontypeable by serologic methods. Pili, expressed by 89%, were most often PI-2a. CPS and pilus-specific IgG increased during convalescence among patients with strains expressing CPS or PI. All GBS expressed CPS or PI; 79% expressed both. Increased antibodies to CPS and PI during recovery suggests that GBS bacteremia in adults is potentially vaccine preventable. PMID:27767008

  2. Genetic analysis of Streptococcus suis isolates from wild rabbits.

    PubMed

    Sánchez del Rey, V; Fernández-Garayzábal, J F; Briones, V; Iriso, A; Domínguez, L; Gottschalk, M; Vela, A I

    2013-08-30

    This work aims to investigate the presence of Streptococcus suis in wild rabbits. A total of 65 S. suis isolates were recovered from 33.3% of the wild rabbits examined. Most isolates (86.2%) belong to genotype cps9. These isolates were further characterized by pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and virulence genotyping. Overall, S. suis exhibited a low genetic diversity. Only 5 genetic profiles were obtained by PFGE and most isolates (71.4%) were included in two pulsotypes that were also widely distributed among the wild rabbit population. MLST analysis assigned all cps9 isolates into three new singlestones (ST216, ST217 and ST284), which were not genetically related to the European ST87 and Spanish ST61 widespread swine clones, indicating a different genetic background for the S. suis isolates from wild rabbits and pigs. Wild rabbit isolates exhibited the genotype mrp-/epf-/sly-, different from those showed by most of the swine S. suis isolates of the ST87 and ST61 clones. None of the S. suis isolated from wild rabbits exhibited the genotype cps2/mrp+/epf+/sly+ associated with human infections. These results indicate that S. suis isolates from wild rabbits are not genetically related with prevalent clones usually associated with infections in pigs or humans in Europe and do not exhibit either their virulence genotypes. Therefore, although wild rabbits could represent an unknown reservoir of this pathogen, they could not represent a potential risk for pigs or humans.

  3. Streptococcus iniae Virulence Is Associated with a Distinct Genetic Profile

    PubMed Central

    Fuller, Jeffrey D.; Bast, Darrin J.; Nizet, Victor; Low, Donald E.; de Azavedo, Joyce C. S.

    2001-01-01

    Streptococcus iniae causes meningoencephalitis and death in commercial fish species and has recently been identified as an emerging human pathogen producing fulminant soft tissue infection. As identified by pulsed-field gel electrophoresis (PFGE), strains causing disease in either fish or humans belong to a single clone, whereas isolates from nondiseased fish are genetically diverse. In this study, we used in vivo and in vitro models to examine the pathogenicity of disease-associated isolates. Strains with the clonal (disease-associated) PFGE profile were found to cause significant weight loss and bacteremia in a mouse model of subcutaneous infection. As little as 102 CFU of a disease-associated strain was sufficient to establish bacteremia, with higher inocula (107) resulting in increased mortality. In contrast, non-disease-associated (commensal) strains failed to cause bacteremia and weight loss, even at inocula of 108 CFU. In addition, disease-associated strains were more resistant to phagocytic clearance in a human whole blood killing assay compared to commensal strains, which were almost entirely eradicated. Disease-associated strains were also cytotoxic to human endothelial cells as measured by lactate dehydrogenase release from host cells. However, both disease-associated and commensal strains adhered to and invaded cultured human epithelial and endothelial cells equally well. While cellular invasion may still contribute to the pathogenesis of invasive S. iniae disease, resistance to phagocytic clearance and direct cytotoxicity appear to be discriminating virulence attributes of the disease-associated clone. PMID:11254550

  4. Streptococcus agalactiae impairs cerebral bioenergetics in experimentally infected silver catfish.

    PubMed

    Baldissera, Matheus D; Souza, Carine F; Parmeggiani, Belisa S; Santos, Roberto C V; Leipnitz, Guilhian; Moreira, Karen L S; da Rocha, Maria Izabel U M; da Veiga, Marcelo L; Baldisserotto, Bernardo

    2017-10-01

    It is becoming evident that bacterial infectious diseases affect brain energy metabolism, where alterations of enzymatic complexes of the mitochondrial respiratory chain and creatine kinase (CK) lead to an impairment of cerebral bioenergetics which contribute to disease pathogenesis in the central nervous system (CNS). Based on this evidence, the aim of this study was to evaluate whether alterations in the activity of complex IV of the respiratory chain and CK contribute to impairment of cerebral bioenergetics during Streptococcus agalactiae infection in silver catfish (Rhamdia quelen). The activity of complex IV of the respiratory chain in brain increased, while the CK activity decreased in infected animals compared to uninfected animals. Brain histopathology revealed inflammatory demyelination, gliosis of the brain and intercellular edema in infected animals. Based on this evidence, S. agalactiae infection causes an impairment in cerebral bioenergetics through the augmentation of complex IV activity, which may be considered an adaptive response to maintain proper functioning of the electron respiratory chain, as well as to ensure ongoing electron flow through the electron transport chain. Moreover, inhibition of cerebral CK activity contributes to lower availability of ATP, contributing to impairment of cerebral energy homeostasis. In summary, these alterations contribute to disease pathogenesis linked to the CNS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Streptococcus mutans: a new Gram-positive paradigm?

    PubMed

    Lemos, José A; Quivey, Robert G; Koo, Hyun; Abranches, Jacqueline

    2013-03-01

    Despite the enormous contributions of the bacterial paradigms Escherichia coli and Bacillus subtilis to basic and applied research, it is well known that no single organism can be a perfect representative of all other species. However, given that some bacteria are difficult, or virtually impossible, to cultivate in the laboratory, that some are recalcitrant to genetic and molecular manipulation, and that others can be extremely dangerous to manipulate, the use of model organisms will continue to play an important role in the development of basic research. In particular, model organisms are very useful for providing a better understanding of the biology of closely related species. Here, we discuss how the lifestyle, the availability of suitable in vitro and in vivo systems, and a thorough understanding of the genetics, biochemistry and physiology of the dental pathogen Streptococcus mutans have greatly advanced our understanding of important areas in the field of bacteriology such as interspecies biofilms, competence development and stress responses. In this article, we provide an argument that places S. mutans, an organism that evolved in close association with the human host, as a novel Gram-positive model organism.

  6. [Invasive Streptococcus pneumoniae infection (Austrian syndrome): a case report].

    PubMed

    Echeverri, Daniel; Vargas, María de los Ángeles; Matta, Lorena; Rosso, Fernando; Segura, Janier Daniel

    2015-01-01

    Austrian syndrome is defined as the triad consisting of pneumonia, endocarditis and meningitis due to invasive Streptococcus pneumoniae infection. Few case reports have been reported since its first description in 1975 by Robert Austrian, mainly because it is rarely observed. Below we report the case of a 61 year-old male patient who presented with bacterial meningitis due S. pneumoniae followed by bacterial pneumonia and severe mitral regurgitation, associated with four vegetations on the atrial surface of the posterior mitral leaflet; in addition, there was rupture and prolapse of its middle scallop. The S. pneumoniae bacterium was isolated from cerebrospinal fluid and blood cultures. In consequence, the patient was given broad-spectrum antibiotic therapy and had an early valve replacement performed, obtaining a good clinical outcome. The key prognostic factor of the Austrian syndrome is determined by the damage of cardiac valves, particularly in patients with a compromised aortic valve; hence, it is necessary to identify the degree of valve injury and define surgical and antibiotic treatment on a timely fashion. However, in subacute, less frequent clinical cases where the mitral valve is the main valve compromised, usually a directed antibiotic therapy associated with advanced support measures are sufficient to control this infection.

  7. Potential Transmission Pathways of Streptococcus gallolyticus subsp. gallolyticus

    PubMed Central

    Dumke, Jessika; Hinse, Dennis; Vollmer, Tanja; Schulz, Jochen; Knabbe, Cornelius; Dreier, Jens

    2015-01-01

    Streptococcus gallolyticus subsp. gallolyticus (S. gallolyticus subsp. gallolyticus), a member of group D streptococci, is an inhabitant of the animal and human gastrointestinal tract. Furthermore, it is a facultative pathogen which causes e.g. endocarditis, septicemia and mastitis. S. gallolyticus subsp. gallolyticus may be transmitted either directly or indirectly between animals and humans. However, the transmission routes are an unsolved issue. In this study, we present systematic analyses of an S. gallolyticus subsp. gallolyticus isolate of an infective endocarditis patient in relation to isolates of his laying hen flock. Isolates from pooled droppings of laying hens, pooled dust samples and human blood culture were characterized by using multilocus sequence typing (MLST) and DNA fingerprinting. MLST revealed the same allelic profile of isolates from the human blood culture and from the droppings of laying hens. In addition, these isolates showed clonal identity regarding a similar DNA fingerprinting pattern. For the first time, we received a hint that transmission of S. gallolyticus subsp. gallolyticus between poultry and humans may occur. This raises the question about the zoonotic potential of isolates from poultry and should be considered in future studies. PMID:25978355

  8. Fluoride exposure attenuates expression of Streptococcus pyogenes virulence factors.

    PubMed

    Thongboonkerd, Visith; Luengpailin, Jirapon; Cao, Junkai; Pierce, William M; Cai, Jian; Klein, Jon B; Doyle, R J

    2002-05-10

    Fluoridation causes an obvious reduction of dental caries by interference with cariogenic streptococci. However, the effect of fluoride on group A streptococci that causes rheumatic fever and acute poststreptococcal glomerulonephritis is not known. We have used proteomic analysis to create a reference proteome map for Streptococcus pyogenes and to determine fluoride-induced protein changes in the streptococci. Cellular and extracellular proteins were resolved by two-dimensional polyacrylamide gel electrophoresis and identified by matrix-assisted laser desorption ionization mass spectrometry. 183 protein spots were visualized, and 74 spots representing 60 unique proteins were identified. A 16-h exposure to sodium fluoride caused decreased expression of proteins required to respond to cellular stress, including anti-oxidants, glycolytic enzymes, transcriptional and translational regulators, and protein folding. Fluoride caused decreased cellular expression of two well-characterized S. pyogenes virulence factors. Fluoride decreased expression of glyceraldehyde-3-phosphate dehydrogenase, which acts to bind fibronectin and promote bacterial adherence. We also performed proteomic analysis of protein released by S. pyogenes into the culture supernatant and observed decreased expression of M proteins following fluoride exposure. These data provide evidence that fluoride causes decreased expression by S. pyogenes proteins used to respond to stress, virulence factors, and implicated in non-suppurative complications of S. pyogenes, including glomerulonephritis and rheumatic fever.

  9. Fluoroquinolone resistance in Streptococcus pneumoniae from a university hospital, Thailand.

    PubMed

    Srifuengfung, Somporn; Tribuddharat, Chanwit; Chokephaibulkit, Kulkanya; Comerungsee, Sopita

    2010-11-01

    The most frequent markers of fluoroquinolone resistance in S. pneumoniae are chromosomal mutations in the quinolone-resistance-determining regions of DNA gyrase and topoisomerase IV encoding for the gyrA, gyrB and parC, parE genes. In 2008, 6.5% of the Streptococcus pneumoniae isolates in a Bangkok university hospital were resistant to ofloxacin. Using PCR and DNA sequencing, we identified mutations in both the gyrA and parC genes of four ofloxacin- and ciprofloxacin-resistant S. pneumoniae isolates (minimum inhibitory concentrations > 32 microg/ml). Mutations were found in the gyrA gene at positions Ser81Phe, Glu85Gly, Glu85Lys and in the parC gene at position Ser79Tyr. Three isolates had mutations in both genes. Two of the isolates were serotype 6B and two were serotypes not contained in currently licensed pneumococcal vaccines. This is the first report of the mechanisms of fluoroquinolone resistance in S. pneumoniae in Thailand.

  10. Costs of CRISPR-Cas-mediated resistance in Streptococcus thermophilus

    PubMed Central

    Vale, Pedro F.; Lafforgue, Guillaume; Gatchitch, Francois; Gardan, Rozenn; Moineau, Sylvain; Gandon, Sylvain

    2015-01-01

    CRISPR-Cas is a form of adaptive sequence-specific immunity in microbes. This system offers unique opportunities for the study of coevolution between bacteria and their viral pathogens, bacteriophages. A full understanding of the coevolutionary dynamics of CRISPR-Cas requires knowing the magnitude of the cost of resisting infection. Here, using the gram-positive bacterium Streptococcus thermophilus and its associated virulent phage 2972, a well-established model system harbouring at least two type II functional CRISPR-Cas systems, we obtained different fitness measures based on growth assays in isolation or in pairwise competition. We measured the fitness cost associated with different components of this adaptive immune system: the cost of Cas protein expression, the constitutive cost of increasing immune memory through additional spacers, and the conditional costs of immunity during phage exposure. We found that Cas protein expression is particularly costly, as Cas-deficient mutants achieved higher competitive abilities than the wild-type strain with functional Cas proteins. Increasing immune memory by acquiring up to four phage-derived spacers was not associated with fitness costs. In addition, the activation of the CRISPR-Cas system during phage exposure induces significant but small fitness costs. Together these results suggest that the costs of the CRISPR-Cas system arise mainly due to the maintenance of the defence system. We discuss the implications of these results for the evolution of CRISPR-Cas-mediated immunity. PMID:26224708

  11. Characterization of Afb, a novel bifunctional protein in Streptococcus agalactiae

    PubMed Central

    Dehbashi, Sanaz; Pourmand, Mohammad Reza; Mashhadi, Rahil

    2016-01-01

    Background and Objectives: Streptococcus agalactiae is the leading cause of bacterial sepsis and meningitis in newborns and results in pneumonia and bacteremia in adults. A number of S. agalactiae components are involved in colonization of target cells. Destruction of peptidoglycan and division of covalently linked daughter cells is mediated by autolysins. In this study, autolytic activity and plasma binding ability of AFb novel recombinant protein of S. agalactiae was investigated. Materials and Methods: The gbs1805 gene was cloned and expressed. E. coli strains DH5α and BL21 were used as cloning and expression hosts, respectively. After purification, antigenicity and binding ability to plasma proteins of the recombinant protein was evaluated. Results: AFb, the 18KDa protein was purified successfully. The insoluble mature protein revealed the ability to bind to fibrinogen and fibronectin. This insoluble mature protein revealed that it has the ability to bind to fibrinogen and fibronectin plasma proteins. Furthermore, in silico analysis demonstrated the AFb has an autolytic activity. Conclusions: AFb is a novel protein capable of binding to fibrinogen and fibronectin. This findings lay a ground work for further investigation of the role of the bacteria in adhesion and colonization to the host. PMID:27092228

  12. Genome of the Opportunistic Pathogen Streptococcus sanguinis▿ †

    PubMed Central

    Xu, Ping; Alves, Joao M.; Kitten, Todd; Brown, Arunsri; Chen, Zhenming; Ozaki, Luiz S.; Manque, Patricio; Ge, Xiuchun; Serrano, Myrna G.; Puiu, Daniela; Hendricks, Stephanie; Wang, Yingping; Chaplin, Michael D.; Akan, Doruk; Paik, Sehmi; Peterson, Darrell L.; Macrina, Francis L.; Buck, Gregory A.

    2007-01-01

    The genome of Streptococcus sanguinis is a circular DNA molecule consisting of 2,388,435 bp and is 177 to 590 kb larger than the other 21 streptococcal genomes that have been sequenced. The G+C content of the S. sanguinis genome is 43.4%, which is considerably higher than the G+C contents of other streptococci. The genome encodes 2,274 predicted proteins, 61 tRNAs, and four rRNA operons. A 70-kb region encoding pathways for vitamin B12 biosynthesis and degradation of ethanolamine and propanediol was apparently acquired by horizontal gene transfer. The gene complement suggests new hypotheses for the pathogenesis and virulence of S. sanguinis and differs from the gene complements of other pathogenic and nonpathogenic streptococci. In particular, S. sanguinis possesses a remarkable abundance of putative surface proteins, which may permit it to be a primary colonizer of the oral cavity and agent of streptococcal endocarditis and infection in neutropenic patients. PMID:17277061

  13. A novel adaptation of aldolase regulates virulence in Streptococcus pyogenes

    PubMed Central

    Loughman, Jennifer A; Caparon, Michael G

    2006-01-01

    Regulation of virulence factor expression is critical for pathogenic microorganisms that must sense and adapt to a dynamic host environment; yet, the signal transduction pathways that enable this process are generally poorly understood. Here, we identify LacD.1 as a global regulator of virulence factor expression in the versatile human pathogen, Streptococcus pyogenes. LacD.1 is derived from a class I tagatose-1,6-bisphosphate aldolase homologous to those involved in lactose and galactose metabolism in related prokaryotes. However, regulation of transcription by LacD.1 is not dependent on this enzymatic activity or the canonical catabolite repression pathway, but likely does require substrate recognition. Our results suggest that LacD.1 has been adapted as a metabolic sensor, and raise the possibility that regulation of gene expression by metabolic enzymes may be a novel mechanism by which Gram-positive bacteria, including S. pyogenes, coordinate multiple environmental cues, allowing essential transcription programs to be coupled with perceived nutritional status. PMID:17066081

  14. Fluoroquinolone Resistance in Penicillin-resistant Streptococcus pneumoniae Clones, Spain

    PubMed Central

    Balsalobre, Luz; Ardanuy, Carmen; Fenoll, Asunción; Pérez-Trallero, Emilio; Liñares, Josefina

    2004-01-01

    Among 2,882 Streptococcus pneumoniae sent to the Spanish Reference Laboratory during 2002, 75 (2.6%) were ciprofloxacin-resistant. Resistance was associated with older patients (3.9% in adults and 7.2% in patients >65 years of age), with isolation from noninvasive sites (4.3% vs. 1.0%), and with penicillin and macrolide resistance. Among 14 low-level resistant (MIC 4–8 µg/mL) strains, 1 had a fluoroquinolone efflux phenotype, and 13 showed single ParC changes. The 61 high-level ciprofloxacin-resistant (MIC >16 µg/mL) strains showed either two or three changes at ParC, ParE, and GyrA. Resistance was acquired either by point mutation (70 strains) or by recombination with viridans streptococci (4 strains) at the topoisomerase II genes. Although 36 pulsed-field gel electrophoresis patterns were observed, 5 international multiresistant clones (Spain23F-1, Spain6B-2, Spain9V-3, Spain14-5 and Sweden15A-25) accounted for 35 (46.7%) of the ciprofloxacin-resistant strains. Continuous surveillance is needed to prevent the dissemination of these clones. PMID:15504260

  15. Fluoroquinolone resistance in penicillin-resistant Streptococcus pneumoniae clones, Spain.

    PubMed

    de la Campa, Adela G; Balsalobre, Luz; Ardanuy, Carmen; Fenoll, Asunción; Pérez-Trallero, Emilio; Liñares, Josefina

    2004-10-01

    Among 2,882 Streptococcus pneumoniae sent to the Spanish Reference Laboratory during 2002, 75 (2.6%) were ciprofloxacin-resistant. Resistance was associated with older patients (3.9% in adults and 7.2% in patients > or =65 years of age), with isolation from noninvasive sites (4.3% vs. 1.0%), and with penicillin and macrolide resistance. Among 14 low-level resistant (MIC 4-8 microg/mL) strains, 1 had a fluoroquinolone efflux phenotype, and 13 showed single ParC changes. The 61 high-level ciprofloxacin-resistant (MIC > or =16 microg/mL) strains showed either two or three changes at ParC, ParE, and GyrA. Resistance was acquired either by point mutation (70 strains) or by recombination with viridans streptococci (4 strains) at the topoisomerase II genes. Although 36 pulsed-field gel electrophoresis patterns were observed, 5 international multiresistant clones (Spain23F-1, Spain6B-2, Spain9V-3, Spain14-5 and Sweden15A-25) accounted for 35 (46.7%) of the ciprofloxacin-resistant strains. Continuous surveillance is needed to prevent the dissemination of these clones.

  16. Streptococcus pyogenes biofilms—formation, biology, and clinical relevance

    PubMed Central

    Fiedler, Tomas; Köller, Thomas; Kreikemeyer, Bernd

    2015-01-01

    Streptococcus pyogenes (group A streptococci, GAS) is an exclusive human bacterial pathogen. The virulence potential of this species is tremendous. Interactions with humans range from asymptomatic carriage over mild and superficial infections of skin and mucosal membranes up to systemic purulent toxic-invasive disease manifestations. Particularly the latter are a severe threat for predisposed patients and lead to significant death tolls worldwide. This places GAS among the most important Gram-positive bacterial pathogens. Many recent reviews have highlighted the GAS repertoire of virulence factors, regulators and regulatory circuits/networks that enable GAS to colonize the host and to deal with all levels of the host immune defense. This covers in vitro and in vivo studies, including animal infection studies based on mice and more relevant, macaque monkeys. It is now appreciated that GAS, like many other bacterial species, do not necessarily exclusively live in a planktonic lifestyle. GAS is capable of microcolony and biofilm formation on host cells and tissues. We are now beginning to understand that this feature significantly contributes to GAS pathogenesis. In this review we will discuss the current knowledge on GAS biofilm formation, the biofilm-phenotype associated virulence factors, regulatory aspects of biofilm formation, the clinical relevance, and finally contemporary treatment regimens and future treatment options. PMID:25717441

  17. Streptococcus pneumoniae capsule determines disease severity in experimental pneumococcal meningitis

    PubMed Central

    Grandgirard, Denis; Valente, Luca G.; Täuber, Martin G.; Leib, Stephen L.

    2016-01-01

    Streptococcus pneumoniae bacteria can be characterized into over 90 serotypes according to the composition of their polysaccharide capsules. Some serotypes are common in nasopharyngeal carriage whereas others are associated with invasive disease, but when carriage serotypes do invade disease is often particularly severe. It is unknown whether disease severity is due directly to the capsule type or to other virulence factors. Here, we used a clinical pneumococcal isolate and its capsule-switch mutants to determine the effect of capsule, in isolation from the genetic background, on severity of meningitis in an infant rat model. We found that possession of a capsule was essential for causing meningitis. Serotype 6B caused significantly more mortality than 7F and this correlated with increased capsule thickness in the cerebrospinal fluid (CSF), a stronger inflammatory cytokine response in the CSF and ultimately more cortical brain damage. We conclude that capsule type has a direct effect on meningitis severity. This is an important consideration in the current era of vaccination targeting a subset of capsule types that causes serotype replacement. PMID:27009189

  18. Antibiotic-resistant Streptococcus pneumoniae. Implications for medical practice.

    PubMed Central

    Wang, E. E.; Kellner, J. D.; Arnold, S.

    1998-01-01

    OBJECTIVE: To review the definition and prevalence of antibiotic-resistant Streptococcus pneumoniae, its links with antibiotic prescribing, data on antibiotic prescribing and prescribing appropriateness, and evidence-based treatment guidelines for common respiratory tract syndromes. QUALITY OF EVIDENCE: Primary studies consist of cross-sectional surveys and case-control studies. Treatment guidelines are based on clinical trials, meta-analyses, and cohort studies. Study designs were appropriate for the specific study questions. MAIN FINDINGS: The increasing prevalence of penicillin-resistant S pneumoniae is concurrent with increasing antibiotic prescribing. Individual patients show a twofold to ninefold increase in nasopharyngeal carriage of resistant bacteria or invasion with resistant bacteria (among those who have received antibiotics in the preceding 3 months). Cross-sectional data as well as data from medicaid and drug databases attest to overprescribing of antibiotics for respiratory tract infections. Physician surveys and focus groups blame this on parental pressure for antibiotic prescriptions. However, parents in focus groups and surveys deny they pressure their physicians and indicate their main purpose for office visits is to obtain a diagnosis and to seek reassurance that their children are not seriously ill. Evidence-based guidelines suggest treatment strategies that would reduce antibiotic prescribing. CONCLUSIONS: The few antibiotics that can be used with resistant organisms are expensive and are increasingly being needed. To control the rise of antibiotic resistance, it is important to limit antibiotic overprescribing. PMID:9789668

  19. Mast cells impair host defense during murine Streptococcus pneumoniae pneumonia.

    PubMed

    van den Boogaard, Florry E; Brands, Xanthe; Roelofs, Joris J T H; de Beer, Regina; de Boer, Onno J; van 't Veer, Cornelis; van der Poll, Tom

    2014-11-01

    Streptococcus pneumoniae is the most common causative pathogen in community-acquired pneumonia. Mast cells (MCs) are located mainly at the host-environment interface where they function as sentinels. Our goal was to study the role of MCs during pneumonia caused by S. pneumoniae. Lung tissue of patients who had died from pneumococcal pneumonia or a nonpulmonary cause was stained for MCs and tryptase. Wild-type (WT) and MC-deficient (Kit(W-sh/W-sh)) mice were observed or sacrificed after induction of pneumonia by intranasal inoculation of S. pneumoniae. In separate experiments, WT mice were treated with doxantrazole or cromoglycate, which are MC stabilizing agents. The constitutive presence of tryptase-positive MCs was reduced in affected lungs from pneumonia patients. Kit(W-sh/W-sh) mice showed a prolonged survival during the first few days after median lethal dose (LD)100 and LD50 infection, while overall mortality did not differ from that in WT mice. Relative to WT mice, Kit(W-sh/W-sh) mice showed reduced bacterial counts with less bacterial dissemination to distant organs and less inflammation. Neither doxantrazole nor cromoglycate influenced antibacterial defense or inflammatory responses after airway infection with S. pneumoniae. MCs exhibit an unfavorable role in host defense during pneumococcal pneumonia by a mechanism independent of degranulation. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Thrombocytopenia impairs host defense during murine Streptococcus pneumoniae pneumonia.

    PubMed

    van den Boogaard, Florry E; Schouten, Marcel; de Stoppelaar, Sacha F; Roelofs, Joris J T H; Brands, Xanthe; Schultz, Marcus J; van't Veer, Cornelis; van der Poll, Tom

    2015-03-01

    Streptococcus pneumoniae is the most common causative pathogen in community-acquired pneumonia. In patients, thrombocytopenia is correlated with an adverse outcome of pneumonia. Platelets can modulate the host response to infection in several ways, that is, by facilitating clot formation, production of antimicrobial proteins, and interaction with neutrophils. We studied the effect of thrombocytopenia during murine pneumococcal pneumonia. Animal study. University research laboratory. Mice. Pneumonia was induced by intranasal inoculation of S. pneumoniae. Platelets were depleted by anti-mouse thrombocyte serum; controls received nonimmunogenic serum. In separate studies, mice were treated with the platelet P2Y12 receptor inhibitor clopidogrel or placebo. Thrombocytopenic mice (platelet counts < 1% of uninfected controls) showed a reduced survival during pneumococcal pneumonia (27% vs 75% among controls; p = 0.003), which was associated with higher bacterial loads in lungs, spleen, and blood. Thrombocytopenic mice showed enhanced coagulation activation (thrombin-antithrombin complexes) in plasma. Proinflammatory cytokine levels were higher in plasma but not in lungs of thrombocytopenic mice. Although clopidogrel treatment strongly prolonged the bleeding time, it did not impact on bacterial loads during pneumococcal pneumonia. Platelets play a protective role during pneumococcal pneumonia independent of their aggregation.