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Sample records for streptococcus pyogenes causantes

  1. [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. PMID:25456681

  2. 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

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

    PubMed

    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

  4. Surface Interactome in Streptococcus pyogenes*

    PubMed Central

    Galeotti, Cesira L.; Bove, Elia; Pezzicoli, Alfredo; Nogarotto, Renzo; Norais, Nathalie; Pileri, Silvia; Lelli, Barbara; Falugi, Fabiana; Balloni, Sergio; Tedde, Vittorio; Chiarot, Emiliano; Bombaci, Mauro; Soriani, Marco; Bracci, Luisa; Grandi, Guido; Grifantini, Renata

    2012-01-01

    Very few studies have so far been dedicated to the systematic analysis of protein interactions occurring between surface and/or secreted proteins in bacteria. Such interactions are expected to play pivotal biological roles that deserve investigation. Taking advantage of the availability of a detailed map of surface and secreted proteins in Streptococcus pyogenes (group A Streptococcus (GAS)), we used protein array technology to define the “surface interactome” in this important human pathogen. Eighty-three proteins were spotted on glass slides in high density format, and each of the spotted proteins was probed for its capacity to interact with any of the immobilized proteins. A total of 146 interactions were identified, 25 of which classified as “reciprocal,” namely, interactions that occur irrespective of which of the two partners was immobilized on the chip or in solution. Several of these interactions were validated by surface plasmon resonance and supported by confocal microscopy analysis of whole bacterial cells. By this approach, a number of interesting interactions have been discovered, including those occurring between OppA, DppA, PrsA, and TlpA, proteins known to be involved in protein folding and transport. These proteins, all localizing at the septum, might be part, together with HtrA, of the recently described ExPortal complex of GAS. Furthermore, SpeI was found to strongly interact with the metal transporters AdcA and Lmb. Because SpeI strictly requires zinc to exert its function, this finding provides evidence on how this superantigen, a major player in GAS pathogenesis, can acquire the metal in the host environment, where it is largely sequestered by carrier proteins. We believe that the approach proposed herein can lead to a deeper knowledge of the mechanisms underlying bacterial invasion, colonization, and pathogenesis. PMID:22199230

  5. Surface interactome in Streptococcus pyogenes.

    PubMed

    Galeotti, Cesira L; Bove, Elia; Pezzicoli, Alfredo; Nogarotto, Renzo; Norais, Nathalie; Pileri, Silvia; Lelli, Barbara; Falugi, Fabiana; Balloni, Sergio; Tedde, Vittorio; Chiarot, Emiliano; Bombaci, Mauro; Soriani, Marco; Bracci, Luisa; Grandi, Guido; Grifantini, Renata

    2012-04-01

    Very few studies have so far been dedicated to the systematic analysis of protein interactions occurring between surface and/or secreted proteins in bacteria. Such interactions are expected to play pivotal biological roles that deserve investigation. Taking advantage of the availability of a detailed map of surface and secreted proteins in Streptococcus pyogenes (group A Streptococcus (GAS)), we used protein array technology to define the "surface interactome" in this important human pathogen. Eighty-three proteins were spotted on glass slides in high density format, and each of the spotted proteins was probed for its capacity to interact with any of the immobilized proteins. A total of 146 interactions were identified, 25 of which classified as "reciprocal," namely, interactions that occur irrespective of which of the two partners was immobilized on the chip or in solution. Several of these interactions were validated by surface plasmon resonance and supported by confocal microscopy analysis of whole bacterial cells. By this approach, a number of interesting interactions have been discovered, including those occurring between OppA, DppA, PrsA, and TlpA, proteins known to be involved in protein folding and transport. These proteins, all localizing at the septum, might be part, together with HtrA, of the recently described ExPortal complex of GAS. Furthermore, SpeI was found to strongly interact with the metal transporters AdcA and Lmb. Because SpeI strictly requires zinc to exert its function, this finding provides evidence on how this superantigen, a major player in GAS pathogenesis, can acquire the metal in the host environment, where it is largely sequestered by carrier proteins. We believe that the approach proposed herein can lead to a deeper knowledge of the mechanisms underlying bacterial invasion, colonization, and pathogenesis. PMID:22199230

  6. Molecular typing of Chinese Streptococcus pyogenes isolates.

    PubMed

    You, Yuanhai; Wang, Haibin; Bi, Zhenwang; Walker, Mark; Peng, Xianhui; Hu, Bin; Zhou, Haijian; Song, Yanyan; Tao, Xiaoxia; Kou, Zengqiang; Meng, Fanliang; Zhang, Menghan; Bi, Zhenqiang; Luo, Fengji; Zhang, Jianzhong

    2015-06-01

    Streptococcus pyogenes causes human infections ranging from mild pharyngitis and impetigo to serious diseases including necrotizing fasciitis and streptococcal toxic shock syndrome. The objective of this study was to compare molecular emm typing and pulsed field gel electrophoresis (PFGE) with multiple-locus variable-number tandem-repeat analysis (MLVA) for genotyping of Chinese S. pyogenes isolates. Molecular emm typing and PFGE were performed using standard protocols. Seven variable number tandem repeat (VNTR) loci reported in a previous study were used to genotype 169 S. pyogenes geographically-diverse isolates from China isolated from a variety of disease syndromes. Multiple-locus variable-number tandem-repeat analysis provided greater discrimination between isolates when compared to emm typing and PFGE. Removal of a single VNTR locus (Spy2) reduced the sensitivity by only 0.7%, which suggests that Spy2 was not informative for the isolates screened. The results presented support the use of MLVA as a powerful epidemiological tool for genotyping S. pyogenes clinical isolates. PMID:25843529

  7. 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

  8. 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. PMID:22615992

  9. Interactions of Lactobacilli with Pathogenic Streptococcus pyogenes

    PubMed Central

    Westbroek, Mark L.; Davis, Crystal L.; Fawson, Lena S.; Price, Travis M.

    2010-01-01

    Objective. To determine whether (1) a decreased concentration of Lactobacilli allows S. pyogenes to grow; (2) S. pyogenes is able to grow in the presence of healthy Lactobacillus concentrations; (3) S. pyogenes is capable of inhibiting Lactobacilli. Methods. One hundred fifty patient samples of S. pyogenes were mixed with four different concentrations of L. crispatus and L. jensenii. Colony counts and pH measurements were taken from these concentrations and compared using t-tests and ANOVA statistical analyses. Results. Statistical tests showed no significant difference between the colony counts of S. pyogenes by itself and growth when mixed with Lactobacilli, and no significant difference between the colony counts of S. pyogenes in the four different concentrations of Lactobacilli. Conclusion. The statistical data representing the growth of these two organisms suggests that Lactobacilli did not inhibit the growth of S. pyogenes. Also, S. pyogenes did not inhibit the growth of Lactobacilli. PMID:20508738

  10. Status of research and development of vaccines for Streptococcus pyogenes.

    PubMed

    Steer, Andrew C; Carapetis, Jonathan R; Dale, James B; Fraser, John D; Good, Michael F; Guilherme, Luiza; Moreland, Nicole J; Mulholland, E Kim; Schodel, Florian; Smeesters, Pierre R

    2016-06-01

    Streptococcus pyogenes is an important global pathogen, causing considerable morbidity and mortality, especially in low and middle income countries where rheumatic heart disease and invasive infections are common. There is a number of promising vaccine candidates, most notably those based on the M protein, the key virulence factor for the bacterium. Vaccines against Streptococcus pyogenes are considered as impeded vaccines because of a number of crucial barriers to development. Considerable effort is needed by key players to bring current vaccine candidates through phase III clinical trials and there is a clear need to develop a roadmap for future development of current and new candidates. PMID:27032515

  11. Is Streptococcus pyogenes resistant or susceptible to trimethoprim-sulfamethoxazole?

    PubMed

    Bowen, Asha C; Lilliebridge, Rachael A; Tong, Steven Y C; Baird, Robert W; Ward, Peter; McDonald, Malcolm I; Currie, Bart J; Carapetis, Jonathan R

    2012-12-01

    Streptococcus pyogenes is commonly believed to be resistant to trimethoprim-sulfamethoxazole (SXT), resulting in reservations about using SXT for skin and soft tissue infections (SSTI) where S. pyogenes is involved. S. pyogenes' in vitro susceptibility to SXT depends on the medium's thymidine content. Thymidine allows S. pyogenes to bypass the sulfur-mediated inhibition of folate metabolism and, historically, has resulted in apparently reduced susceptibility of S. pyogenes to sulfur antibacterials. The low thymidine concentration in Mueller-Hinton agar (MHA) is now regulated. We explored S. pyogenes susceptibility to SXT on various media. Using two sets of 100 clinical S. pyogenes isolates, we tested for susceptibility using SXT Etests on MHA containing defibrinated horse blood and 20 mg/liter β-NAD (MHF), MHA with sheep blood (MHS), MHA alone, MHA with horse blood (MHBA), and MHA with lysed horse blood (MHLHBA). European Committee on Antibacterial Susceptibility Testing (EUCAST) breakpoints defined susceptibility (MIC, ≤ 1 mg/liter) and resistance (MIC, >2 mg/liter). In study 1, 99% of S. pyogenes isolates were susceptible to SXT on MHA, MHBA, and MHLHBA, with geometric mean MICs of 0.04, 0.04, and 0.05 mg/liter, respectively. In study 2, all 100 S. pyogenes isolates were susceptible to SXT on MHF, MHS, MHA, and MHLHBA with geometric mean MICs of 0.07, 0.16, 0.07, and 0.09 mg/liter, respectively. This study confirms the in vitro susceptibility of S. pyogenes to SXT, providing support for the use of SXT for SSTIs. A clinical trial using SXT for impetigo is ongoing. PMID:23052313

  12. 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

  13. 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. PMID:23662123

  14. 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

  15. 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. PMID:18463210

  16. Epidemiology of Severe Streptococcus pyogenes Disease in Europe▿

    PubMed Central

    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

    2008-01-01

    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. PMID:18463210

  17. Increase in invasive Streptococcus pyogenes and Streptococcus pneumoniae infections in England, December 2010 to January 2011.

    PubMed

    Zakikhany, K; Degail, M A; Lamagni, T; Waight, P; Guy, R; Zhao, H; Efstratiou, A; Pebody, R; George, R; Ramsay, M

    2011-01-01

    Increases in invasive Streptococcus pyogenes and S. pneumoniae above the seasonally expected levels are currently being seen in England. Preliminary analyses suggest that the high level of influenza activity seen this winter may be contributing to an increased risk of concurrent invasive bacterial and influenza infections in children and young adults. PMID:21315057

  18. One More Disguise in the Stealth Behavior of Streptococcus pyogenes

    PubMed Central

    Dale, James B.

    2016-01-01

    ABSTRACT The ability to hide in the animal kingdom is essential for survival; the same is true for bacteria. Streptococcus pyogenes is considered one of the more successful stealth bacteria in its production of a hyaluronic acid capsule that is chemically identical to the hyaluronic acid lining human joints. It has also acquired the capacity to enter eukaryotic cells to avoid the onslaught of the host’s immune defenses, as well as drugs. From this intracellular vantage point, it may remain dormant from days to weeks, only to cause disease again at a later time, perhaps causing a relapse in a drug-treated patient. We now learn that it is able to enter macrophages as well, enabling the Streptococcus to use this “Trojan horse” approach to be transported to distant sites in the body. PMID:27190219

  19. One More Disguise in the Stealth Behavior of Streptococcus pyogenes.

    PubMed

    Fischetti, Vincent A; Dale, James B

    2016-01-01

    The ability to hide in the animal kingdom is essential for survival; the same is true for bacteria. Streptococcus pyogenes is considered one of the more successful stealth bacteria in its production of a hyaluronic acid capsule that is chemically identical to the hyaluronic acid lining human joints. It has also acquired the capacity to enter eukaryotic cells to avoid the onslaught of the host's immune defenses, as well as drugs. From this intracellular vantage point, it may remain dormant from days to weeks, only to cause disease again at a later time, perhaps causing a relapse in a drug-treated patient. We now learn that it is able to enter macrophages as well, enabling the Streptococcus to use this "Trojan horse" approach to be transported to distant sites in the body. PMID:27190219

  20. Cationic Antimicrobial Peptides Disrupt the Streptococcus pyogenes ExPortal

    PubMed Central

    Vega, Luis Alberto; Caparon, Michael G.

    2012-01-01

    Summary Although they possess a well-characterized ability to porate the bacterial membrane, emerging research suggests that cationic antimicrobial peptides (CAPs) can influence pathogen behavior at levels that are sub-lethal. In this study, we investigated the interaction of polymyxin B and human neutrophil peptide (HNP-1) with the human pathogen Streptococcus pyogenes. At sub-lethal 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. PMID:22780862

  1. Transcriptional Analysis of the Streptococcus pyogenes Salivaricin Locus

    PubMed Central

    Namprachan-Frantz, Phanramphoei; Rowe, Hannah M.; Runft, Donna L.

    2014-01-01

    The sal lantibiotic locus plays an important role in the virulence of Streptococcus pyogenes. Our transcriptional analysis of the sal locus provides new information on the complex regulation of this operon. Transcription of the operon is regulated by a promoter upstream of the operon and by a second internal promoter upstream of the salKRZ genes. Here we identify the location of the internal promoter and provide information on how this promoter is autoregulated by proteins within the locus. We determined by primer extension that the salKR promoter is located within the salY gene and identified several regulatory regions important for expression. The higher activity of the promoter in a salKR deletion strain indicates a role in repression by the SalR response regulator. Further, this promoter had higher activity in a salA deletion strain, implicating corepression or a signaling role for the SalA peptide. Finally, we demonstrate that this promoter can be controlled by host factors. Analysis of transcriptional regulation of this locus provides a better understanding of the function of the sal locus in S. pyogenes pathogenesis. PMID:24244008

  2. 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. PMID:19594623

  3. [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. PMID:12861520

  4. IdeS and SpeB: immunoglobulin-degrading cysteine proteinases of Streptococcus pyogenes.

    PubMed

    von Pawel-Rammingen, Ulrich; Björck, Lars

    2003-02-01

    The Gram-positive bacterium Streptococcus pyogenes is a major human pathogen causing substantial morbidity and mortality in society. S. pyogenes has evolved numerous molecular mechanisms to avoid the various actions of the human immune system and has established means to modulate both adaptive and innate immune responses. S. pyogenes produces and secretes proteolytic enzymes, which have an important impact on the ability of the bacteria to survive in the human host. Prominent among these are two immunoglobulin-degrading enzymes: the newly discovered streptococcal cysteine proteinase, IdeS, and the classical cysteine proteinase of S. pyogenes, SpeB. PMID:12615219

  5. 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

  6. Identification of Rgg-regulated exoproteins of Streptococcus pyogenes.

    PubMed

    Chaussee, M S; Watson, R O; Smoot, J C; Musser, J M

    2001-02-01

    Streptococcus pyogenes secretes many proteins that influence host-pathogen interactions. Despite their importance, relatively little is known about the regulation of these proteins. The rgg gene (also known as ropB) is required for the expression of streptococcal erythrogenic toxin B (SPE B), an extracellular cysteine protease that contributes to virulence. Proteomics was used to determine if rgg regulates the expression of additional exoproteins. Exponential- and stationary-phase culture supernatant proteins made by S. pyogenes NZ131 rgg and NZ131 speB were separated by two-dimensional electrophoresis. Differences were identified in supernatant proteins from both exponential- and stationary-phase cultures, although considerably more differences were detected among stationary-phase supernatant proteins. Forty-two proteins were identified by peptide fingerprinting with matrix-assisted laser desorption mass spectrometry. Mitogenic factor, DNA entry nuclease (open reading frame [ORF 226]), and ORF 953, which has no known function, were more abundant in the culture supernatants of the rgg mutant compared to the speB mutant. ClpB, lysozyme, and autolysin were detected in the culture supernatant of the speB mutant but not the rgg mutant. To determine if Rgg affected protein expression at the transcriptional level, real-time (TaqMan) reverse transcription (RT)-PCR was used to quantitate Rgg-regulated transcripts from NZ131 wild-type and speB and rgg mutant strains. The results obtained with RT-PCR correlated with the proteomic data. We conclude that Rgg regulates the transcription of several genes expressed primarily during the stationary phase of growth. PMID:11159974

  7. Identification of Rgg-Regulated Exoproteins of Streptococcus pyogenes

    PubMed Central

    Chaussee, Michael S.; Watson, Robert O.; Smoot, James C.; Musser, James M.

    2001-01-01

    Streptococcus pyogenes secretes many proteins that influence host-pathogen interactions. Despite their importance, relatively little is known about the regulation of these proteins. The rgg gene (also known as ropB) is required for the expression of streptococcal erythrogenic toxin B (SPE B), an extracellular cysteine protease that contributes to virulence. Proteomics was used to determine if rgg regulates the expression of additional exoproteins. Exponential- and stationary-phase culture supernatant proteins made by S. pyogenes NZ131 rgg and NZ131 speB were separated by two-dimensional electrophoresis. Differences were identified in supernatant proteins from both exponential- and stationary-phase cultures, although considerably more differences were detected among stationary-phase supernatant proteins. Forty-two proteins were identified by peptide fingerprinting with matrix-assisted laser desorption mass spectrometry. Mitogenic factor, DNA entry nuclease (open reading frame [ORF 226]), and ORF 953, which has no known function, were more abundant in the culture supernatants of the rgg mutant compared to the speB mutant. ClpB, lysozyme, and autolysin were detected in the culture supernatant of the speB mutant but not the rgg mutant. To determine if Rgg affected protein expression at the transcriptional level, real-time (TaqMan) reverse transcription (RT)-PCR was used to quantitate Rgg-regulated transcripts from NZ131 wild-type and speB and rgg mutant strains. The results obtained with RT-PCR correlated with the proteomic data. We conclude that Rgg regulates the transcription of several genes expressed primarily during the stationary phase of growth. PMID:11159974

  8. Comparative functional analysis of the lac operons in Streptococcus pyogenes.

    PubMed

    Loughman, Jennifer A; Caparon, Michael G

    2007-04-01

    Having no known environmental reservoir, Streptococcus pyogenes, a bacterium responsible for a wider variety of human diseases than any other bacterial species, must rely on its host for metabolic substrates. Although a streptococcal aldolase, LacD.1, has been adapted to virulence gene regulation, both LacD.1 and a paralogous protein, LacD.2, are predicted to function in the tagatose 6-phosphate pathway for lactose and galactose utilization. In order to gain insight into the mechanism of the LacD.1 regulatory pathway and the role of genome context in the emergence of LacD.1's novel regulatory functions, we compared the function and regulation of the Lac.1 and Lac.2 loci. The Lac.1 operon is not inducible, and regulation by LacD.1 is independent of a functional tagatose 6-phosphate pathway and enhanced by the conserved truncation of upstream Lac.1 genes. In contrast, Lac.2 expression is sensitive to environmental carbohydrates, and LacD.2, not LacD.1, contributes to growth on galactose. Thus, we conclude that the Lac.1 locus has been specialized to participate in regulation, leaving efficient utilization of carbohydrate sources to the Lac.2 locus. The adaptation of LacD for transcription regulation may be an underappreciated strategy among prokaryotes, as homologues of this multifaceted enzyme are present in a broad range of species. PMID:17371500

  9. 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

  10. 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. PMID:21877175

  11. Vaccination against the M protein of Streptococcus pyogenes prevents death after influenza virus:S. pyogenes super-infection

    PubMed Central

    Klonoski, Joshua M.; Hurtig, Heather R.; Juber, Brian A.; Schuneman, Margaret J.; Bickett, Thomas E.; Svendsen, Joshua M.; Burum, Brandon; Penfound, Thomas A.; Sereda, Grigoriy; Dale, James B.; Chaussee, Michael S.; Huber, Victor C.

    2014-01-01

    Influenza virus infections are associated with a significant number of illnesses and deaths on an annual basis. Many of the deaths are due to complications from secondary bacterial invaders, including Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pyogenes. The β-hemolytic bacteria S. pyogenes colonizes both skin and respiratory surfaces, and frequently presents clinically as strep throat or impetigo. However, when these bacteria gain access to normally sterile sites, they can cause deadly diseases including sepsis, necrotizing fasciitis, and pneumonia. We previously developed a model of influenza virus:S. pyogenes super-infection, which we used to demonstrate that vaccination against influenza virus can limit deaths associated with a secondary bacterial infection, but this protection was not complete. In the current study, we evaluated the efficacy of a vaccine that targets the M protein of S. pyogenes to determine whether immunity toward the bacteria alone would allow the host to survive an influenza virus:S. pyogenes super-infection. Our data demonstrate that vaccination against the M protein induces IgG antibodies, in particular those of the IgG1 and IgG2a isotypes, and that these antibodies can interact with macrophages. Ultimately, this vaccine-induced immunity eliminated death within our influenza virus:S. pyogenes super-infection model, despite the fact that all M protein-vaccinated mice showed signs of illness following influenza virus inoculation. These findings identify immunity against bacteria as an important component of protection against influenza virus:bacteria super-infection. PMID:25077423

  12. Vaccination against the M protein of Streptococcus pyogenes prevents death after influenza virus: S. pyogenes super-infection.

    PubMed

    Klonoski, Joshua M; Hurtig, Heather R; Juber, Brian A; Schuneman, Margaret J; Bickett, Thomas E; Svendsen, Joshua M; Burum, Brandon; Penfound, Thomas A; Sereda, Grigoriy; Dale, James B; Chaussee, Michael S; Huber, Victor C

    2014-09-01

    Influenza virus infections are associated with a significant number of illnesses and deaths on an annual basis. Many of the deaths are due to complications from secondary bacterial invaders, including Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pyogenes. The β-hemolytic bacteria S. pyogenes colonizes both skin and respiratory surfaces, and frequently presents clinically as strep throat or impetigo. However, when these bacteria gain access to normally sterile sites, they can cause deadly diseases including sepsis, necrotizing fasciitis, and pneumonia. We previously developed a model of influenza virus:S. pyogenes super-infection, which we used to demonstrate that vaccination against influenza virus can limit deaths associated with a secondary bacterial infection, but this protection was not complete. In the current study, we evaluated the efficacy of a vaccine that targets the M protein of S. pyogenes to determine whether immunity toward the bacteria alone would allow the host to survive an influenza virus:S. pyogenes super-infection. Our data demonstrate that vaccination against the M protein induces IgG antibodies, in particular those of the IgG1 and IgG2a isotypes, and that these antibodies can interact with macrophages. Ultimately, this vaccine-induced immunity eliminated death within our influenza virus:S. pyogenes super-infection model, despite the fact that all M protein-vaccinated mice showed signs of illness following influenza virus inoculation. These findings identify immunity against bacteria as an important component of protection against influenza virus:bacteria super-infection. PMID:25077423

  13. Rapid emergence of emm84 among invasive Streptococcus pyogenes infections in Finland.

    PubMed

    Siljander, Tuula; Lyytikäinen, Outi; Vähäkuopus, Susanna; Säilä, Petrus; Jalava, Jari; Vuopio-Varkila, Jaana

    2009-02-01

    From 2005 to 2007, in Finland, the incidence of invasive Streptococcus pyogenes disease increased sharply, partly due to the uncommon emm84 gene becoming more prevalent from 2006 onwards. The overall case fatality rate of infections caused by strains carrying emm84 was not significantly different than that of infections caused by other types (7% versus 10%, respectively; P = 0.50). PMID:19073871

  14. Rapid Emergence of emm84 among Invasive Streptococcus pyogenes Infections in Finland▿

    PubMed Central

    Siljander, Tuula; Lyytikäinen, Outi; Vähäkuopus, Susanna; Säilä, Petrus; Jalava, Jari; Vuopio-Varkila, Jaana

    2009-01-01

    From 2005 to 2007, in Finland, the incidence of invasive Streptococcus pyogenes disease increased sharply, partly due to the uncommon emm84 gene becoming more prevalent from 2006 onwards. The overall case fatality rate of infections caused by strains carrying emm84 was not significantly different than that of infections caused by other types (7% versus 10%, respectively; P = 0.50). PMID:19073871

  15. Identification of the Streptococcus pyogenes surface antigens recognised by pooled human immunoglobulin

    PubMed Central

    Reglinski, Mark; Gierula, Magdalena; Lynskey, Nicola N.; Edwards, Robert J.; Sriskandan, Shiranee

    2015-01-01

    Immunity to common bacteria requires the generation of antibodies that promote opsonophagocytosis and neutralise toxins. Pooled human immunoglobulin is widely advocated as an adjunctive treatment for clinical Streptococcus pyogenes infection however, the protein targets of the reagent remain ill defined. Affinity purification of the anti-streptococcal antibodies present within pooled immunoglobulin resulted in the generation of an IgG preparation that promoted opsonophagocytic killing of S. pyogenes in vitro and provided passive immunity in vivo. Isolation of the streptococcal surface proteins recognised by pooled human immunoglobulin permitted identification and ranking of 94 protein antigens, ten of which were reproducibly identified across four contemporary invasive S. pyogenes serotypes (M1, M3, M12 and M89). The data provide novel insight into the action of pooled human immunoglobulin during invasive S. pyogenes infection, and demonstrate a potential route to enhance the efficacy of antibody based therapies. PMID:26508447

  16. Chromosomal islands of Streptococcus pyogenes and related streptococci: molecular switches for survival and virulence

    PubMed Central

    Nguyen, Scott V.; McShan, William M.

    2014-01-01

    Streptococcus pyogenes is a significant pathogen of humans, annually causing over 700,000,000 infections and 500,000 deaths. Virulence in S. pyogenes is closely linked to mobile genetic elements like phages and chromosomal islands (CI). S. pyogenes phage-like chromosomal islands (SpyCI) confer a complex mutator phenotype on their host. SpyCI integrate into the 5′ end of DNA mismatch repair (MMR) gene mutL, which also disrupts downstream operon genes lmrP, ruvA, and tag. During early logarithmic growth, SpyCI excise from the bacterial chromosome and replicate as episomes, relieving the mutator phenotype. As growth slows and the cells enter stationary phase, SpyCI reintegrate into the chromosome, again silencing the MMR operon. This system creates a unique growth-dependent and reversible mutator phenotype. Additional CI using the identical attachment site in mutL have been identified in related species, including Streptococcus dysgalactiae subsp. equisimilis, Streptococcus anginosus, Streptococcus intermedius, Streptococcus parauberis, and Streptococcus canis. These CI have small genomes, which range from 13 to 20 kB, conserved integrase and DNA replication genes, and no identifiable genes encoding capsid proteins. SpyCI may employ a helper phage for packaging and dissemination in a fashion similar to the Staphylococcus aureus pathogenicity islands (SaPI). Outside of the core replication and integration genes, SpyCI and related CI show considerable diversity with the presence of many indels that may contribute to the host cell phenotype or fitness. SpyCI are a subset of a larger family of streptococcal CI who potentially regulate the expression of other host genes. The biological and phylogenetic analysis of streptococcal chromosomal islands provides important clues as to how these chromosomal islands help S. pyogenes and other streptococcal species persist in human populations in spite of antibiotic therapy and immune challenges. PMID:25161960

  17. Chromosomal islands of Streptococcus pyogenes and related streptococci: molecular switches for survival and virulence.

    PubMed

    Nguyen, Scott V; McShan, William M

    2014-01-01

    Streptococcus pyogenes is a significant pathogen of humans, annually causing over 700,000,000 infections and 500,000 deaths. Virulence in S. pyogenes is closely linked to mobile genetic elements like phages and chromosomal islands (CI). S. pyogenes phage-like chromosomal islands (SpyCI) confer a complex mutator phenotype on their host. SpyCI integrate into the 5' end of DNA mismatch repair (MMR) gene mutL, which also disrupts downstream operon genes lmrP, ruvA, and tag. During early logarithmic growth, SpyCI excise from the bacterial chromosome and replicate as episomes, relieving the mutator phenotype. As growth slows and the cells enter stationary phase, SpyCI reintegrate into the chromosome, again silencing the MMR operon. This system creates a unique growth-dependent and reversible mutator phenotype. Additional CI using the identical attachment site in mutL have been identified in related species, including Streptococcus dysgalactiae subsp. equisimilis, Streptococcus anginosus, Streptococcus intermedius, Streptococcus parauberis, and Streptococcus canis. These CI have small genomes, which range from 13 to 20 kB, conserved integrase and DNA replication genes, and no identifiable genes encoding capsid proteins. SpyCI may employ a helper phage for packaging and dissemination in a fashion similar to the Staphylococcus aureus pathogenicity islands (SaPI). Outside of the core replication and integration genes, SpyCI and related CI show considerable diversity with the presence of many indels that may contribute to the host cell phenotype or fitness. SpyCI are a subset of a larger family of streptococcal CI who potentially regulate the expression of other host genes. The biological and phylogenetic analysis of streptococcal chromosomal islands provides important clues as to how these chromosomal islands help S. pyogenes and other streptococcal species persist in human populations in spite of antibiotic therapy and immune challenges. PMID:25161960

  18. Identification and characterization of a Streptococcus pyogenes ABC transporter with multiple specificity for metal cations.

    PubMed

    Janulczyk, R; Pallon, J; Björck, L

    1999-11-01

    Metal ions are crucial trace elements for bacteria infecting the human host. The LraI (lipoprotein receptor-associated antigen I) transporter in Streptococcus spp. belongs to the superfamily of ABC transporters. The transporter consists of a lipoprotein, an ATP-binding protein and a hydrophobic integral membrane protein. Here, we describe a new member of the LraI family in the important human pathogen Streptococcus pyogenes. The system was identified in silico by analysis of the S. pyogenes Genome Sequencing Project. The S. pyogenes operon exhibits an atypical organization compared with equivalents in other Streptococcus spp. The presence and atypical organization of the operon was verified in a number of S. pyogenes strains of different serotypes. Transcriptional analysis of the LraI operon demonstrates a polycistronic transcription attenuated by a stable stem-loop structure, which allows the lipoprotein to be expressed in larger quantities than the other two components. The localization of the native lipoprotein at the bacterial surface was shown by proteolytic digestion of S. pyogenes bacteria and NH2-terminal sequencing of a released lipoprotein fragment. Recombinant lipoprotein was expressed as a GST fusion protein, and studies of molecular interactions with metal radioisotopes demonstrated that the protein has affinity for Zn(II), Fe(III) and Cu(II). Zn(II) and Cu(II) were found to compete for the same binding site, whereas Fe(III) uses a second site. Also, proton-induced X-ray analysis of lipoprotein samples identified iron, copper and zinc. Finally, a mutant strain lacking a functional mtsABC operon was generated and showed reduced uptake of 55Fe and 65Zn compared with the wild-type strain. The operon encoding this novel ABC transporter with multiple specificity for metal cations is designated mtsABC, for metal transporter of Streptococcus. PMID:10564500

  19. Structure-function and pathogenesis studies of Streptococcus pyogenes extracellular cysteine protease.

    PubMed

    Burns, E H; Marciel, A M; Musser, J M

    1997-01-01

    Replacement of the single cysteine residue (C192) with serine in the Streptococcus pyogenes extracellular cysteine protease (SCP) prevented auto-catalytic processing of the 40-kDa zymogen to the 28-kDa mature form and eliminated proteolytic activity. SCP incubated with human endothelial cells induced a time- and concentration-dependent increase in a 66-kDa gelatinase/type IV collagenase in culture supernatants. Activation of this gelatinase/collagenase may contribute to endothelial cell damage, tissue destruction, and hemodynamic derangement observed in some patients with severe, invasive S. pyogenes infection. PMID:9331720

  20. Development of a multicomponent vaccine for Streptococcus pyogenes based on the antigenic targets of IVIG

    PubMed Central

    Reglinski, Mark; Lynskey, Nicola N.; Choi, Yoon Jung; Edwards, Robert J.; Sriskandan, Shiranee

    2016-01-01

    Summary Objectives Despite over a century of research and the careful scrutiny of many promising targets, there is currently no vaccine available for the prevention of Streptococcus pyogenes infection. Through analysis of the protective, anti-streptococcal components of pooled human immunoglobulin, we previously identified ten highly conserved and invariant S. pyogenes antigens that contribute to anti-streptococcal immunity in the adult population. We sought to emulate population immunity to S. pyogenes through a process of active vaccination, using the antigens targeted by pooled human immunoglobulin. Methods Seven targets were produced recombinantly and mixed to form a multicomponent vaccine (Spy7). Vaccinated mice were challenged with S. pyogenes isolates representing four globally relevant serotypes (M1, M3, M12 and M89) using an established model of invasive disease. Results Vaccination with Spy7 stimulated the production of anti-streptococcal antibodies, and limited systemic dissemination of M1 and M3 S. pyogenes from an intramuscular infection focus. Vaccination additionally attenuated disease severity due to M1 S. pyogenes as evidenced by reduction in weight loss, and modulated cytokine release. Conclusion Spy7 vaccination successfully stimulated the generation of protective anti-streptococcal immunity in vivo. Identification of reactive antigens using pooled human immunoglobulin may represent a novel route to vaccine discovery for extracellular bacteria. PMID:26880087

  1. Pyogenic Sacroiliitis due to Group A Streptococcus following Uncomplicated Pregnancy and Vaginal Delivery

    PubMed Central

    Owen, Alexander Michael; Adno, Alan Maurice; Marry, Jyothi

    2013-01-01

    Background. Although the incidence of pregnancy-associated pyogenic sacroiliitis is low, it is associated with significant morbidity and mortality. Timely diagnosis of the condition is challenging due to its nonspecific clinical features. Case. A 31-year-old primigravida had an uncomplicated pregnancy and labour. Postpartum, she developed persistent fever and debilitating hip pain on ambulation. White cell count was normal (7.3 × 109/L) and C-reactive protein was elevated (468.4 mg/L). Streptococcus pyogenes was identified on vaginal swabs and blood cultures, and a pelvic magnetic resonance imaging scan revealed bilateral sacroiliitis. Conclusion. Pyogenic sacroiliitis is a potentially lethal cause of postpartum pain. It should be considered as a differential diagnosis even in low-risk women who present with debilitating pelvic pain in or around pregnancy, particularly when initial therapy appears unsuccessful. PMID:24396619

  2. Pyogenic Sacroiliitis due to Group A Streptococcus following Uncomplicated Pregnancy and Vaginal Delivery.

    PubMed

    Park, Yoon Sik; Owen, Alexander Michael; Adno, Alan Maurice; Marry, Jyothi

    2013-01-01

    Background. Although the incidence of pregnancy-associated pyogenic sacroiliitis is low, it is associated with significant morbidity and mortality. Timely diagnosis of the condition is challenging due to its nonspecific clinical features. Case. A 31-year-old primigravida had an uncomplicated pregnancy and labour. Postpartum, she developed persistent fever and debilitating hip pain on ambulation. White cell count was normal (7.3 × 10(9)/L) and C-reactive protein was elevated (468.4 mg/L). Streptococcus pyogenes was identified on vaginal swabs and blood cultures, and a pelvic magnetic resonance imaging scan revealed bilateral sacroiliitis. Conclusion. Pyogenic sacroiliitis is a potentially lethal cause of postpartum pain. It should be considered as a differential diagnosis even in low-risk women who present with debilitating pelvic pain in or around pregnancy, particularly when initial therapy appears unsuccessful. PMID:24396619

  3. EndoS and SpeB from Streptococcus pyogenes inhibit immunoglobulin-mediated opsonophagocytosis.

    PubMed

    Collin, Mattias; Svensson, Mikael D; Sjöholm, Anders G; Jensenius, Jens C; Sjöbring, Ulf; Olsén, Arne

    2002-12-01

    The human pathogen Streptococcus pyogenes primarily infects the upper respiratory tract and skin, but occasionally it disseminates and causes severe invasive disease with high mortality. This study revealed that the activity of extracellular EndoS, which hydrolyzes the functionally important N-linked oligosaccharides on opsonizing immunoglobulin G (IgG), contributes to increased survival of S. pyogenes in human blood ex vivo. The inability to kill the bacteria is due to reduced binding of IgG to Fc receptors and impaired classical pathway-mediated activation of complement. In addition, the activity of extracellular SpeB, which cleaves IgG into Fc and Fab fragments, also increases bacterial survival. This suggests that S. pyogenes expresses two enzymes, EndoS and SpeB, which modulate IgG by different mechanisms in order to evade the adaptive immune system. PMID:12438337

  4. EndoS and SpeB from Streptococcus pyogenes Inhibit Immunoglobulin-Mediated Opsonophagocytosis

    PubMed Central

    Collin, Mattias; Svensson, Mikael D.; Sjöholm, Anders G.; Jensenius, Jens C.; Sjöbring, Ulf; Olsén, Arne

    2002-01-01

    The human pathogen Streptococcus pyogenes primarily infects the upper respiratory tract and skin, but occasionally it disseminates and causes severe invasive disease with high mortality. This study revealed that the activity of extracellular EndoS, which hydrolyzes the functionally important N-linked oligosaccharides on opsonizing immunoglobulin G (IgG), contributes to increased survival of S. pyogenes in human blood ex vivo. The inability to kill the bacteria is due to reduced binding of IgG to Fc receptors and impaired classical pathway-mediated activation of complement. In addition, the activity of extracellular SpeB, which cleaves IgG into Fc and Fab fragments, also increases bacterial survival. This suggests that S. pyogenes expresses two enzymes, EndoS and SpeB, which modulate IgG by different mechanisms in order to evade the adaptive immune system. PMID:12438337

  5. Streptococcus pyogenes Infection in a Free-Living European Hedgehog (Erinaceus europaeus).

    PubMed

    Franklinos, Lydia H V; Efstratiou, Androulla; Macgregor, Shaheed K; John, Shinto K; Hopkins, Timothy; Cunningham, Andrew A; Lawson, Becki

    2015-12-01

    Streptococcus pyogenes, a common pathogen of humans, was isolated from the carcass of a free-living European hedgehog (Erinaceus europaeus) found in northern England in June 2014. The animal had abscessation of the deep right cervical lymph node, mesenteric lymph nodes and liver. The S. pyogenes strain isolated from the lesions, peritoneal and pleural cavities was characterised as emm 28, which can be associated with invasive disease in humans. This is the first known report of S. pyogenes in a hedgehog and in any free-living wild animal that has been confirmed by gene sequencing. As close associations between wild hedgehogs and people in England are common, we hypothesise that this case might have resulted from anthroponotic infection. PMID:26242215

  6. Purification, crystallization and preliminary crystallographic analysis of Streptococcus pyogenes laminin-binding protein Lbp

    SciTech Connect

    Linke, Christian; Caradoc-Davies, Tom T.; Proft, Thomas; Baker, Edward N.

    2008-02-01

    The S. pyogenes laminin-binding protein Lbp, which is essential for adhesion to human laminin, has been expressed, purified and crystallized. The laminin-binding protein Lbp (Spy2007) from Streptococcus pyogenes (a group A streptococcus) mediates adhesion to the human basal lamina glycoprotein laminin. Accordingly, Lbp is essential in in vitro models of cell adhesion and invasion. However, the molecular and structural basis of laminin binding by bacteria remains unknown. Therefore, the lbp gene has been cloned for recombinant expression in Escherichia coli. Lbp has been purified and crystallized from 30%(w/v) PEG 1500 by the sitting-drop vapour-diffusion method. The crystals belonged to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 42.62, b = 92.16, c = 70.61 Å, β = 106.27°, and diffracted to 2.5 Å resolution.

  7. Recurrent Streptococcus pyogenes genital infection in a woman: test and treat the partner!

    PubMed

    Verkaeren, Emilienne; Epelboin, Loïc; Epelboin, Sylvie; Boddaert, Nathalie; Brossier, Florence; Caumes, Eric

    2014-12-01

    Group A Streptococcus (GAS) is a well-known cause of vulvovaginitis in prepubescent girls, but it is rarely described in adult women. We describe the case of a 64-year-old woman who presented with endometritis revealed by GAS bacteraemia, followed by recurrent vulvovaginitis due to a wild-type strain of GAS. She relapsed twice despite amoxicillin treatment. Her husband was found to be an asymptomatic carrier after GAS was identified in nasal and rectal swabs. She was cured after eradication of carriage in both herself and her husband with amoxicillin and rifampin. When recurrent Streptococcus pyogenes genital infections occur, test and treat the partner. PMID:25449232

  8. Adapting a diet from sugar to meat: double-dealing genes of Streptococcus pyogenes.

    PubMed

    Rosch, Jason W; Tuomanen, Elaine

    2007-04-01

    Intuitively, paralogues created by gene duplication should retain related functions. However, a study of the two lactose metabolic operons of Streptococcus pyogenes, reported in this issue of Molecular Microbiology, indicates that paralogues might evolve very different functions, in this case changing from a metabolic enzyme to a regulator of virulence. Divergence of paralogues could be a newly recognized theme in the metamorphosis of a bacteria from innocuous to pathogenic. PMID:17493119

  9. Complete Genome Assembly of Streptococcus pyogenes ATCC 19615, a Group A β-Hemolytic Reference Strain.

    PubMed

    Minogue, T D; Daligault, H A; Davenport, K W; Bishop-Lilly, K A; Broomall, S M; Bruce, D C; Chain, P S; Chertkov, O; Coyne, S R; Freitas, T; Frey, K G; Gibbons, H S; Jaissle, J; Redden, C L; Rosenzweig, C N; Xu, Y; Johnson, S L

    2014-01-01

    We present the complete genome assembly of Streptococcus pyogenes ATCC 19615 (Rosenbach) as submitted to GenBank under accession number CP008926. This group A nonmotile β-hemolytic clinical isolate is used for quality control in a variety of commercially available tests. The assembled genome is 1.84 Mb (38.5% G+C content) and contains 1,788 coding regions. PMID:25258274

  10. Complete Genome Assembly of Streptococcus pyogenes ATCC 19615, a Group A β-Hemolytic Reference Strain

    PubMed Central

    Minogue, T. D.; Daligault, H. A.; Davenport, K. W.; Bishop-Lilly, K. A.; Broomall, S. M.; Bruce, D. C.; Chain, P. S.; Chertkov, O.; Coyne, S. R.; Freitas, T.; Frey, K. G.; Gibbons, H. S.; Jaissle, J.; Redden, C. L.; Rosenzweig, C. N.; Xu, Y.

    2014-01-01

    We present the complete genome assembly of Streptococcus pyogenes ATCC 19615 (Rosenbach) as submitted to GenBank under accession number CP008926. This group A nonmotile β-hemolytic clinical isolate is used for quality control in a variety of commercially available tests. The assembled genome is 1.84 Mb (38.5% G+C content) and contains 1,788 coding regions. PMID:25258274

  11. Kinetics of cytokine profile in response to Mycobacterium bovis BCG and Streptococcus pyogenes activated cells.

    PubMed

    Verma, Vivek; Kumar, Parveen; Dhanda, Rakesh Singh; Yadav, Manisha

    2016-06-01

    The infection of epithelial cells is a necessary step for Mycobacterium bovis BCG dissemination, but the mechanism of mycobacterial epithelial interactions is not completely understood. Similarly, Streptococcus pyogenes is a strictly human pathogen that favorably colonizes the skin and the pharynx. Effective cytokine secretion is essential in order to fabricate a suitable inflammatory response against an infection. In this data article, the cytokine profile in BCG and S. pyogenes activated THP-1 cell line in media after the acute phase of infection by ELISA is described. The interleukin-8 level was increased in response to both BCG and S. pyogenes, but was quite prominent after 24 h and further increased upto 72 h post infection. On the other hand, an increase in IL-6 response to S. pyogenes was observed while there was no response to BCG even after 48 h of infection. A low level of TNF-α was detected upon BCG and S. pyogenes infection. PMID:27014727

  12. Kinetics of cytokine profile in response to Mycobacterium bovis BCG and Streptococcus pyogenes activated cells

    PubMed Central

    Verma, Vivek; Kumar, Parveen; Dhanda, Rakesh Singh; Yadav, Manisha

    2016-01-01

    The infection of epithelial cells is a necessary step for Mycobacterium bovis BCG dissemination, but the mechanism of mycobacterial epithelial interactions is not completely understood. Similarly, Streptococcus pyogenes is a strictly human pathogen that favorably colonizes the skin and the pharynx. Effective cytokine secretion is essential in order to fabricate a suitable inflammatory response against an infection. In this data article, the cytokine profile in BCG and S. pyogenes activated THP-1 cell line in media after the acute phase of infection by ELISA is described. The interleukin-8 level was increased in response to both BCG and S. pyogenes, but was quite prominent after 24 h and further increased upto 72 h post infection. On the other hand, an increase in IL-6 response to S. pyogenes was observed while there was no response to BCG even after 48 h of infection. A low level of TNF-α was detected upon BCG and S. pyogenes infection. PMID:27014727

  13. Inactivation of the Rgg2 Transcriptional Regulator Ablates the Virulence of Streptococcus pyogenes

    PubMed Central

    Zutkis, Anastasia A.; Anbalagan, Srivishnupriya; Chaussee, Michael S.; Dmitriev, Alexander V.

    2014-01-01

    Streptococcus pyogenes adapts to different niches encountered in the human host via the activity of numerous regulatory proteins including the Rgg family of transcriptional regulators. The S. pyogenes chromosome encodes four Rgg paralogues designated Rgg1 (RopB), Rgg2 (MutR), Rgg3, and Rgg4 (ComR). In order to understand the role of the Rgg2 protein in the regulation of metabolic and virulence-associated properties of S. pyogenes, the rgg2 gene was inactivated in the M1 serotype strain SF370. Inactivation of rgg2 increased the growth yield of S. pyogenes in THY broth, increased biofilm formation, and increased production of SIC, which is an important virulence factor that inhibits complement mediated lysis. To identify Rgg2-regulated genes, the transcriptomes of SF370 and the rgg2 mutant strains were compared in the middle-exponential and post-exponential phases of growth. Rgg2 was found to control the expression of dozens of genes primarily in the exponential phase of growth, including genes associated with virulence (sse, scpA, slo, nga, mf-3), DNA transformation, and nucleotide metabolism. Inactivation of rgg2 decreased the ability of S. pyogenes to adhere to epithelial cells. In addition, the mutant strain was more sensitive to killing when incubated with human blood and avirulent in a murine bacteremia model. Finally, inoculation of mice with the avirulent rgg2 mutant of S. pyogenes SF370 conferred complete protection to mice subsequently challenged with the wild-type strain. Restoration of an intact rgg2 gene in mutant strain restored the wild-type phenotypes. Overall, the results demonstrate that Rgg2 is an important regulatory protein in S. pyogenes involved in controlling genes associated with both metabolism and virulence. PMID:25486272

  14. ICESpy009, a Conjugative Genetic Element Carrying mef(E) in Streptococcus pyogenes.

    PubMed

    Del Grosso, Maria; Camilli, Romina; Rizzi, Ermanno; Pietrelli, Alessandro; De Bellis, Gianluca; Pantosti, Annalisa

    2016-07-01

    Efflux-mediated macrolide resistance due to mef(E) and mel, carried by the mega element, is common in Streptococcus pneumoniae, for which it was originally characterized, but it is rare in Streptococcus pyogenes In S. pyogenes, mega was previously found to be enclosed in Tn2009, a composite genetic element of the Tn916 family containing tet(M) and conferring erythromycin and tetracycline resistance. In this study, S. pyogenes isolates containing mef(E), apparently not associated with other resistance determinants, were examined to characterize the genetic context of mega. By whole-genome sequencing of one isolate, MB56Spyo009, we identified a novel composite integrative and conjugative element (ICE) carrying mega, designated ICESpy009, belonging to the ICESa2603 family. ICESpy009 was 55 kb long, contained 61 putative open reading frames (ORFs), and was found to be integrated into hylA, a novel integration site for the ICESa2603 family. The modular organization of the ICE was similar to that of members of the ICESa2603 family carried by different streptococcal species. In addition, a novel cluster of accessory resistance genes was found inside a region that encloses mega. PCR mapping targeting ICESpy009 revealed the presence of a similar ICE in five other isolates under study. While in three isolates the integration site was the same as that of ICESpy009, in two isolates the ICE was integrated into rplL, the typical integration site of the ICESa2603 family. ICESpy009 was able to transfer macrolide resistance by conjugation to both S. pyogenes and S. pneumoniae, showing the first evidence of the transferability of mega from S. pyogenes. PMID:27067338

  15. 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

  16. Characterization of a virulence-associated and cell-wall-located DNase of Streptococcus pyogenes.

    PubMed

    Hasegawa, Tadao; Minami, Masaaki; Okamoto, Akira; Tatsuno, Ichiro; Isaka, Masanori; Ohta, Michio

    2010-01-01

    We investigated culture supernatant proteins from the M1 serotype of Streptococcus pyogenes by two-dimensional gel electrophoresis and peptide mass mapping analysis, and characterized the single protein spots. Among them, we analysed the Spy0747 protein. This protein is homologous to the SsnA protein, a cell-wall-located DNase expressed in Streptococcus suis serotype 2. We designated the Spy0747 protein as SpnA. SpnA protein was also detected in the insoluble fraction of whole-cell lysates using shotgun proteomic analysis, suggesting that SpnA is also located in the cell wall. SpnA was expressed as a glutathione S-transferase-fusion protein in Escherichia coli. We confirmed that the recombinant protein had DNase activity that was dependent on Ca(2+) and Mg(2+), like SsnA. Blood bactericidal assays and mouse infection model experiments showed that the spnA knockout strain was less virulent than the parental strain, thus suggesting that SpnA could play an important role in virulence. Using PCR, we found that the spnA gene was present in all clinical S. pyogenes strains we examined. Our results, together with a previous report identifying Spy0747 as a surface-associated protein, suggest that SpnA is an important cell-wall-located DNase that is generally produced in S. pyogenes and is involved in virulence. PMID:19850619

  17. Cation Reversal of Inhibition of Growth by Valinomycin in Streptococcus pyogenes and Clostridium sporogenes1

    PubMed Central

    Seshachalam, Dutta; Frahm, David H.; Ferraro, Frank M.

    1973-01-01

    Study of the antimicrobial spectrum of valinomycin revealed that, in addition to the gram-positive bacteria reported in literature, Streptococcus pyogenes and Clostridium sporogenes are also susceptible to this antibiotic. The minimal inhibitory concentrations (MIC) of the antibiotic for S. pyogenes grown aerobically and anaerobically did not differ markedly, negating the hypothesis that oxidative phosphorylation is involved in the mechanism of action of this antibiotic. This conclusion is further strengthened by the inhibition of growth of C. sporogenes, an obligate anaerobe. In a medium with a low K+ concentration, the MIC for S. pyogenes was 0.02 μg/ml, the lowest ever recorded for this antibiotic. The inhibition of growth of S. pyogenes and C. sporogenes was readily reversed by addition of K+ to the medium, indicating a compensation for net efflux of K+ from the cells when the transmembrane potential reached equilibrium. In contrast to these bacteria, Bacillus subtilis was less susceptible to the antibiotic when the potassium concentration of the medium was low. The addition of potassium in the presence of valinomycin increased the inhibition of growth, which appears to result from dissipation of metabolic energy as in the mitochondrial system. PMID:4208280

  18. RNA sequencing uncovers antisense RNAs and novel small RNAs in Streptococcus pyogenes.

    PubMed

    Le Rhun, Anaïs; Beer, Yan Yan; Reimegård, Johan; Chylinski, Krzysztof; Charpentier, Emmanuelle

    2016-02-01

    Streptococcus pyogenes is a human pathogen responsible for a wide spectrum of diseases ranging from mild to life-threatening infections. During the infectious process, the temporal and spatial expression of pathogenicity factors is tightly controlled by a complex network of protein and RNA regulators acting in response to various environmental signals. Here, we focus on the class of small RNA regulators (sRNAs) and present the first complete analysis of sRNA sequencing data in S. pyogenes. In the SF370 clinical isolate (M1 serotype), we identified 197 and 428 putative regulatory RNAs by visual inspection and bioinformatics screening of the sequencing data, respectively. Only 35 from the 197 candidates identified by visual screening were assigned a predicted function (T-boxes, ribosomal protein leaders, characterized riboswitches or sRNAs), indicating how little is known about sRNA regulation in S. pyogenes. By comparing our list of predicted sRNAs with previous S. pyogenes sRNA screens using bioinformatics or microarrays, 92 novel sRNAs were revealed, including antisense RNAs that are for the first time shown to be expressed in this pathogen. We experimentally validated the expression of 30 novel sRNAs and antisense RNAs. We show that the expression profile of 9 sRNAs including 2 predicted regulatory elements is affected by the endoribonucleases RNase III and/or RNase Y, highlighting the critical role of these enzymes in sRNA regulation. PMID:26580233

  19. Antibacterial Activity of Rhodomyrtus tomentosa (Aiton) Hassk. Leaf Extract against Clinical Isolates of Streptococcus pyogenes

    PubMed Central

    Limsuwan, Surasak; Kayser, Oliver; Voravuthikunchai, Supayang Piyawan

    2012-01-01

    Ethanol extract of Rhodomyrtus tomentosa (Aiton) Hassk. leaf was evaluated for antibacterial activity against 47 clinical isolates of Streptococcus pyogenes. The extract exhibited good anti-S. pyogenes activity against all the tested isolates with similar minimum inhibitory concentration (MIC, 3.91–62.5 μg mL−1) and minimum bactericidal concentration (MBC, 3.91–62.5 μg mL−1) ranges. No surviving cells were detected at 16 h after treatment with 8 × MIC of the extract. The extract-treated cells demonstrated no lysis and cytoplasmic leakage through the bacterial membrane. Electron micrographs further revealed that the extract did not cause any dramatic changes on the treated cells. Rhodomyrtone, an isolated compound, exhibited good anti-S. pyogenes activity (14 isolates), expressed very low MIC (0.39–1.56 μg mL−1) and MBC (0.39-1.56 μg mL−1) values. Rhodomyrtus tomentosa leaf extract and rhodomyrtone displayed promising antibacterial activity against clinical isolates of S. pyogenes. PMID:22973404

  20. Emerging role of the interleukin-8 cleaving enzyme SpyCEP in clinical Streptococcus pyogenes infection.

    PubMed

    Turner, Claire E; Kurupati, Prathiba; Jones, Michael D; Edwards, Robert J; Sriskandan, Shiranee

    2009-08-15

    Neutrophil chemoattractant interleukin (IL)-8 is cleaved and inactivated by the Streptococcus pyogenes cell envelope protease SpyCEP. A range of clinical S. pyogenes strains of differing emm type demonstrated SpyCEP activity, although transcription of the SpyCEP gene cepA differed 1000-fold between isolates. Disruption of the 2-component regulatory system covR/S in pharyngeal isolates increased cepA transcription 100-fold; this finding is consistent with endogenous CovR/S-mediated repression of cepA being responsible for low SpyCEP expression in some S. pyogenes strains associated with pharyngitis. Among patients with invasive S. pyogenes infection, disease severity and outcome were associated with the SpyCEP activity of the isolate. Lethal invasive isolate H292 (emm81) expressed more cepA than did other tested isolates. This strain carried a unique covR mutation that impaired binding to the cepA promoter. CovR/S sequence comparison in other clinical isolates revealed community-wide dissemination of covS mutations but not covR mutations. The results highlight a potential hazard and underline the importance of continuing molecular epidemiological surveillance for community-wide dissemination of CovR/S mutant hyperinvasive strains. PMID:19591574

  1. Inhibition of Growth and Gene Expression by PNA-peptide Conjugates in Streptococcus pyogenes

    PubMed Central

    Patenge, Nadja; Pappesch, Roberto; Krawack, Franziska; Walda, Claudia; Mraheil, Mobarak Abu; Jacob, Anette; Hain, Torsten; Kreikemeyer, Bernd

    2013-01-01

    While Streptococcus pyogenes is consistently susceptible toward penicillin, therapeutic failure of penicillin treatment has been reported repeatedly and a considerable number of patients exhibit allergic reactions to this substance. At the same time, streptococcal resistance to alternative antibiotics, e.g., macrolides, has increased. Taken together, these facts demand the development of novel therapeutic strategies. In this study, S. pyogenes growth was inhibited by application of peptide-conjugated antisense-peptide nucleic acids (PNAs) specific for the essential gyrase A gene (gyrA). Thereby, HIV-1 Tat peptide-coupled PNAs were more efficient inhibitors of streptococcal growth as compared with (KFF)3K-coupled PNAs. Peptide-anti-gyrA PNAs decreased the abundance of gyrA transcripts in S. pyogenes. Growth inhibition by antisense interference was enhanced by combination of peptide-coupled PNAs with protein-level inhibitors. Antimicrobial synergy could be detected with levofloxacin and novobiocin, targeting the gyrase enzyme, and with spectinomycin, impeding ribosomal function. The prospective application of carrier peptide-coupled antisense PNAs in S. pyogenes covers the use as an antimicrobial agent and the employment as a knock-down strategy for the investigation of virulence factor function. PMID:24193033

  2. RNA sequencing uncovers antisense RNAs and novel small RNAs in Streptococcus pyogenes

    PubMed Central

    Le Rhun, Anaïs; Beer, Yan Yan; Reimegård, Johan; Chylinski, Krzysztof; Charpentier, Emmanuelle

    2016-01-01

    ABSTRACT Streptococcus pyogenes is a human pathogen responsible for a wide spectrum of diseases ranging from mild to life-threatening infections. During the infectious process, the temporal and spatial expression of pathogenicity factors is tightly controlled by a complex network of protein and RNA regulators acting in response to various environmental signals. Here, we focus on the class of small RNA regulators (sRNAs) and present the first complete analysis of sRNA sequencing data in S. pyogenes. In the SF370 clinical isolate (M1 serotype), we identified 197 and 428 putative regulatory RNAs by visual inspection and bioinformatics screening of the sequencing data, respectively. Only 35 from the 197 candidates identified by visual screening were assigned a predicted function (T-boxes, ribosomal protein leaders, characterized riboswitches or sRNAs), indicating how little is known about sRNA regulation in S. pyogenes. By comparing our list of predicted sRNAs with previous S. pyogenes sRNA screens using bioinformatics or microarrays, 92 novel sRNAs were revealed, including antisense RNAs that are for the first time shown to be expressed in this pathogen. We experimentally validated the expression of 30 novel sRNAs and antisense RNAs. We show that the expression profile of 9 sRNAs including 2 predicted regulatory elements is affected by the endoribonucleases RNase III and/or RNase Y, highlighting the critical role of these enzymes in sRNA regulation. PMID:26580233

  3. Proteomic Analysis and Identification of Streptococcus pyogenes Surface-Associated Proteins▿

    PubMed Central

    Severin, Anatoly; Nickbarg, Elliott; Wooters, Joseph; Quazi, Shakey A.; Matsuka, Yury V.; Murphy, Ellen; Moutsatsos, Ioannis K.; Zagursky, Robert J.; Olmsted, Stephen B.

    2007-01-01

    Streptococcus pyogenes is a gram-positive human pathogen that causes a wide spectrum of disease, placing a significant burden on public health. Bacterial surface-associated proteins play crucial roles in host-pathogen interactions and pathogenesis and are important targets for the immune system. The identification of these proteins for vaccine development is an important goal of bacterial proteomics. Here we describe a method of proteolytic digestion of surface-exposed proteins to identify surface antigens of S. pyogenes. Peptides generated by trypsin digestion were analyzed by multidimensional tandem mass spectrometry. This approach allowed the identification of 79 proteins on the bacterial surface, including 14 proteins containing cell wall-anchoring motifs, 12 lipoproteins, 9 secreted proteins, 22 membrane-associated proteins, 1 bacteriophage-associated protein, and 21 proteins commonly identified as cytoplasmic. Thirty-three of these proteins have not been previously identified as cell surface associated in S. pyogenes. Several proteins were expressed in Escherichia coli, and the purified proteins were used to generate specific mouse antisera for use in a whole-cell enzyme-linked immunosorbent assay. The immunoreactivity of specific antisera to some of these antigens confirmed their surface localization. The data reported here will provide guidance in the development of a novel vaccine to prevent infections caused by S. pyogenes. PMID:17142387

  4. Synergy and Mode of Action of Ceftazidime plus Quercetin or Luteolin on Streptococcus pyogenes

    PubMed Central

    Siriwong, Supatcharee; Thumanu, Kanjana; Hengpratom, Tanaporn; Eumkeb, Griangsak

    2015-01-01

    Streptococcus pyogenes causes streptococcal toxic shock syndrome. The recommended therapy has been often failure through the interfering of beta-lactamase-producing bacteria (BLPB). The present study was to investigate antibacterial activity, synergy, and modes of action of luteolin and quercetin using alone and plus ceftazidime against S. pyogenes. The MICs of ceftazidime, luteolin, and quercetin against all S. pyogenes were 0.50, 128, and 128 µg mL−1, respectively. A synergistic effect was exhibited on luteolin and quercetin plus ceftazidime against these strains at fractional inhibitory concentration indices 0.37 and 0.27, respectively, and was confirmed by the viable count. These combinations increased cytoplasmic membrane (CM) permeability, caused irregular cell shape, peptidoglycan, and CM damage, and decreased nucleic acid but increased proteins in bacterial cells. Enzyme assay demonstrated that these flavonoids had an inhibitory activity against β-lactamase. In summary, this study provides evidence that the inhibitory mode of action of luteolin and quercetin may be mediated via three mechanisms: (1) inhibiting of peptidoglycan synthesis, (2) increasing CM permeability, and (3) decreasing nucleic acid but increasing the protein contents of bacterial cells. So, luteolin and quercetin propose the high potential to develop adjunct to ceftazidime for the treatment of coexistence of the BLPB and S. pyogenes infections. PMID:26576195

  5. Absorption of kininogen from human plasma by Streptococcus pyogenes is followed by the release of bradykinin.

    PubMed Central

    Ben Nasr, A; Herwald, H; Sjöbring, U; Renné, T; Müller-Esterl, W; Björck, L

    1997-01-01

    H-kininogen (high-molecular-mass kininogen, HK) is the precursor of the vasoactive peptide hormone bradykinin (BK). Previous work has demonstrated that HK binds to Streptococcus pyogenes through M-proteins, fibrous surface proteins and important virulence factors of these bacteria. Here we find that M-protein-expressing bacteria absorb HK from human plasma. The HK bound to the bacteria was found to be cleaved, and analysis of the degradation pattern suggested that the cleavage of HK at the bacterial surface is associated with the release of BK. Moreover, addition of activated plasma prekallikrein to bacteria preincubated with human plasma, resulted in BK release. This mechanism, by which a potent vasoactive and proinflammatory peptide is generated at the site of infection, should influence the host-parasite relationship during S. pyogenes infections. PMID:9307013

  6. Molecular markers for discriminating Streptococcus pyogenes and S. dysgalactiae subspecies equisimilis.

    PubMed

    McMillan, D J; Vu, T; Bramhachari, P V; Kaul, S Y; Bouvet, A; Shaila, M S; Karmarkar, M G; Sriprakash, K S

    2010-05-01

    Given the increasing aetiological importance of Streptococcus dysgalactiae subspecies equisimilis in diseases which are primarily attributed to S. pyogenes, molecular markers are essential to distinguish these species and delineate their epidemiology more precisely. Many clinical microbiology laboratories rely on agglutination reactivity and biochemical tests to distinguish them. These methods have limitations which are particularly exacerbated when isolates with mixed properties are encountered. In order to provide additional distinguishing parameters that could be used to unequivocally discriminate these two common pathogens, we assess here three molecular targets: the speB gene, intergenic region upstream of the scpG gene (IRSG) and virPCR. Of these, the former two respectively gave positive and negative results for S. pyogenes, and negative and positive results for S. dysgalactiae subsp. equisimilis. Thus, a concerted use of these nucleic acid-based methods is particularly helpful in epidemiological surveillance to accurately assess the relative contribution of these species to streptococcal infections and diseases. PMID:20221892

  7. The Cryptic Competence Pathway in Streptococcus pyogenes Is Controlled by a Peptide Pheromone

    PubMed Central

    Mashburn-Warren, Lauren; Morrison, Donald A.

    2012-01-01

    Horizontal gene transfer is an important means of bacterial evolution that is facilitated by transduction, conjugation, and natural genetic transformation. Transformation occurs after bacterial cells enter a state of competence, where naked DNA is acquired from the extracellular environment. Induction of the competent state relies on signals that activate master regulators, causing the expression of genes involved in DNA uptake, processing, and recombination. All streptococcal species contain the master regulator SigX and SigX-dependent effector genes required for natural genetic transformation; however, not all streptococcal species have been shown to be naturally competent. We recently demonstrated that competence development in Streptococcus mutans requires the type II ComRS quorum-sensing circuit, comprising an Rgg transcriptional activator and a novel peptide pheromone (L. Mashburn-Warren, D. A. Morrison, and M. J. Federle, Mol. Microbiol. 78:589–606, 2010). The type II ComRS system is shared by the pyogenic, mutans, and bovis streptococci, including the clinically relevant pathogen Streptococcus pyogenes. Here, we describe the activation of sigX by a small-peptide pheromone and an Rgg regulator of the type II ComRS class. We confirm previous reports that SigX is functional and able to activate sigX-dependent gene expression within the competence regulon, and that SigX stability is influenced by the cytoplasmic protease ClpP. Genomic analyses of available S. pyogenes genomes revealed the presence of intact genes within the competence regulon. While this is the first report to show natural induction of sigX, S. pyogenes remained nontransformable under laboratory conditions. Using radiolabeled DNA, we demonstrate that transformation is blocked at the stage of DNA uptake. PMID:22730123

  8. Intracellular Streptococcus pyogenes in human macrophages display an altered gene expression profile.

    PubMed

    Hertzén, Erika; Johansson, Linda; Kansal, Rita; Hecht, Alexander; Dahesh, Samira; Janos, Marton; Nizet, Victor; Kotb, Malak; Norrby-Teglund, Anna

    2012-01-01

    Streptococcus pyogenes is an important human pathogen, which has recently gained recognition as an intracellular microorganism during the course of severe invasive infections such as necrotizing fasciitis. Although the surface anchored M protein has been identified as a pivotal factor affecting phagosomal maturation and S. pyogenes survival within macrophages, the overall transcriptional profile required for the pathogen to adapt and persist intracellularly is as of yet unknown. To address this, the gene expression profile of S. pyogenes within human macrophages was determined and compared to that of extracellular bacteria using customized microarrays and real-time qRT-PCR. In order to model the early phase of infection involving adaptation to the intracellular compartment, samples were collected 2h post-infection. Microarray analysis revealed that the expression of 145 streptococcal genes was significantly altered in the intracellular environment. The majority of differentially regulated genes were associated with metabolic and energy-dependent processes. Key up-regulated genes in early phase intracellular bacteria were ihk and irr, encoding a two-component gene regulatory system (TCS). Comparison of gene expression of selected genes at 2h and 6h post-infection revealed a dramatic shift in response regulators over time with a down-regulation of ihk/irr genes concurring with an up-regulation of the covR/S TCS. In re-infection assays, intracellular bacteria from the 6h time point exhibited significantly greater survival within macrophages than did bacteria collected at the 2h time point. An isogenic S. pyogenes mutant deficient in ihk/irr displayed significantly reduced bacterial counts when compared to wild-type bacteria following infection of macrophages. The findings illustrate how gene expression of S. pyogenes during the intracellular life cycle is fine-tuned by temporal expression of specific two-component systems. PMID:22511985

  9. The structure of pyogenecin immunity protein, a novel bacteriocin-like immunity protein from streptococcus pyogenes.

    SciTech Connect

    Chang, C.; Coggill, P.; Bateman, A.; Finn, R.; Cymborowski, M.; Otwinowski, Z.; Minor, W.; Volkart, L.; Joachimiak, A.; Wellcome Trust Sanger Inst.; Univ. of Virginia; UT Southwestern Medical Center

    2009-12-17

    Many Gram-positive lactic acid bacteria (LAB) produce anti-bacterial peptides and small proteins called bacteriocins, which enable them to compete against other bacteria in the environment. These peptides fall structurally into three different classes, I, II, III, with class IIa being pediocin-like single entities and class IIb being two-peptide bacteriocins. Self-protective cognate immunity proteins are usually co-transcribed with these toxins. Several examples of cognates for IIa have already been solved structurally. Streptococcus pyogenes, closely related to LAB, is one of the most common human pathogens, so knowledge of how it competes against other LAB species is likely to prove invaluable. We have solved the crystal structure of the gene-product of locus Spy-2152 from S. pyogenes, (PDB: 2fu2), and found it to comprise an anti-parallel four-helix bundle that is structurally similar to other bacteriocin immunity proteins. Sequence analyses indicate this protein to be a possible immunity protein protective against class IIa or IIb bacteriocins. However, given that S. pyogenes appears to lack any IIa pediocin-like proteins but does possess class IIb bacteriocins, we suggest this protein confers immunity to IIb-like peptides. Combined structural, genomic and proteomic analyses have allowed the identification and in silico characterization of a new putative immunity protein from S. pyogenes, possibly the first structure of an immunity protein protective against potential class IIb two-peptide bacteriocins. We have named the two pairs of putative bacteriocins found in S. pyogenes pyogenecin 1, 2, 3 and 4.

  10. In vitro sensitivity of hemophilus influenzae and streptococcus pyogenes to co-trimoxazole.

    PubMed

    Leers, W D

    1975-06-14

    The invitro testing of Hemophilus influenzae and Streptococcus pyogenes for co-trimoxazole sensitivity requires certain "defined" media that have to be free of inhibitory substances. The use of Columbia agar base with Fildes extract for H. influenzae or of blood agar for S. pyogenes may produce "false-resistant" strains. The addition of thymidine phosphorylases in the form of gentlylysed horse blood (2 to 10%) does not remove all inhibitors in those tests, especially where "undefined" agar bases are used, and results in scanty growth of H. influenzae; the addition of more than 2% results in dark plates, making reading of sensitivities difficult. Fildes agar for testing H. influenzae may be made with enriched sheep or horse blood if the proper "defined" agar base is used. The use of Wellcotest or DST (Oxoid) agar is recommended with Fildes extract for H. influenzae or with blood for S. pyogenes for in vitro testing for co-trimoxazole sensitivity. The addition of thymidine phosphorylase in the form of 2% lysed horse blood does not interfere with reading. However, it results in scanty growth of H. influenzae. Proper inoculation of plates is important. The growth on the plates should be light, dense, but not confluent. Heavy growth may render some strains "false-resistant" even when defined media are used. Our results indicate that many of the previously reported resistant strains of H. influenzae and S. pyogenes may have been "false-resistant" because of the use of "undefined" media. We believe that, in view of our results, respiratory infections may be treated with co-trimoxazole until bacteriologic studies prove that this treatment is contraindicated, since H. influenzae and S. pyogenes are usually found sensitive in vitro under proper conditions. PMID:1093653

  11. Intracellular Streptococcus pyogenes in Human Macrophages Display an Altered Gene Expression Profile

    PubMed Central

    Hertzén, Erika; Johansson, Linda; Kansal, Rita; Hecht, Alexander; Dahesh, Samira; Janos, Marton; Nizet, Victor; Kotb, Malak; Norrby-Teglund, Anna

    2012-01-01

    Streptococcus pyogenes is an important human pathogen, which has recently gained recognition as an intracellular microorganism during the course of severe invasive infections such as necrotizing fasciitis. Although the surface anchored M protein has been identified as a pivotal factor affecting phagosomal maturation and S. pyogenes survival within macrophages, the overall transcriptional profile required for the pathogen to adapt and persist intracellularly is as of yet unknown. To address this, the gene expression profile of S. pyogenes within human macrophages was determined and compared to that of extracellular bacteria using customized microarrays and real-time qRT-PCR. In order to model the early phase of infection involving adaptation to the intracellular compartment, samples were collected 2h post-infection. Microarray analysis revealed that the expression of 145 streptococcal genes was significantly altered in the intracellular environment. The majority of differentially regulated genes were associated with metabolic and energy-dependent processes. Key up-regulated genes in early phase intracellular bacteria were ihk and irr, encoding a two-component gene regulatory system (TCS). Comparison of gene expression of selected genes at 2h and 6h post-infection revealed a dramatic shift in response regulators over time with a down-regulation of ihk/irr genes concurring with an up-regulation of the covR/S TCS. In re-infection assays, intracellular bacteria from the 6h time point exhibited significantly greater survival within macrophages than did bacteria collected at the 2h time point. An isogenic S. pyogenes mutant deficient in ihk/irr displayed significantly reduced bacterial counts when compared to wild-type bacteria following infection of macrophages. The findings illustrate how gene expression of S. pyogenes during the intracellular life cycle is fine-tuned by temporal expression of specific two-component systems. PMID:22511985

  12. [T serotypes distribution and antimicrobial susceptibility of Streptococcus pyogenes in children with pharyngotonsillitis in Asahikawa].

    PubMed

    Sakata, Hiroshi

    2008-12-01

    Between June 2006 and April 2007, I measured T serotypes and antibiotic susceptibilities of 367 strains of Streptococcus pyogenes isolated from children with pharyngotonsillitis in Asahikawa. Prevalent serotypes were 12 (33.8%), 1 (22.9%), and 28 (12.5%). The MIC90s of beta-lactams were 0.008 microg/ml in penicillin G, cefcapene, cefditoren, cefteram, cefdinir and faropenem, and 0.015 microg/ml in amoxicillin. Of 367 isolates, macrolide-resistant (erythromycin > 0.5 micro/ml) strains account for 42 (11.4%). PMID:19288853

  13. Effect of SpeB and EndoS from Streptococcus pyogenes on Human Immunoglobulins

    PubMed Central

    Collin, Mattias; Olsén, Arne

    2001-01-01

    Streptococcus pyogenes secretes a specific immunoglobulin G (IgG)-protease, SpeB, as well as the IgG glycan-hydrolyzing enzyme EndoS. Here we show that SpeB also degrades IgA, IgM, IgD, and IgE. We also show that EndoS only hydrolyzes the glycan moiety on native but not denatured IgG. Thus, SpeB has a broad immunoglobulin-degrading activity, while EndoS is highly specific for IgG. PMID:11598100

  14. Consideration of cysteine protease activity for serological M-typing of clinical Streptococcus pyogenes isolates.

    PubMed

    Morita, Masatomo; Ikebe, Tadayoshi; Watanabe, Haruo

    2004-01-01

    Clinical isolates of Streptococcus pyogenes were classified by serological typing of their surface M protein. Non-M typeable strains with the emm1 gene were characterized as the degradation of M protein caused by overproduction of the extracellular cysteine protease, SpeB. These events are dependent on the growth phase. M protein produced prior to expression of SpeB is degraded in the stationary phase when the active form of SpeB is detected. The proteolytic degradation of M protein should be considered for precise M typing analysis. PMID:15502412

  15. Effect of SpeB and EndoS from Streptococcus pyogenes on human immunoglobulins.

    PubMed

    Collin, M; Olsén, A

    2001-11-01

    Streptococcus pyogenes secretes a specific immunoglobulin G (IgG)-protease, SpeB, as well as the IgG glycan-hydrolyzing enzyme EndoS. Here we show that SpeB also degrades IgA, IgM, IgD, and IgE. We also show that EndoS only hydrolyzes the glycan moiety on native but not denatured IgG. Thus, SpeB has a broad immunoglobulin-degrading activity, while EndoS is highly specific for IgG. PMID:11598100

  16. 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.

  17. Targeted Curing of All Lysogenic Bacteriophage from Streptococcus pyogenes Using a Novel Counter-selection Technique

    PubMed Central

    Euler, Chad W.; Juncosa, Barbara; Ryan, Patricia A.; Deutsch, Douglas R.; McShan, W. Michael; Fischetti, Vincent A.

    2016-01-01

    Streptococcus pyogenes is a human commensal and a bacterial pathogen responsible for a wide variety of human diseases differing in symptoms, severity, and tissue tropism. The completed genome sequences of >37 strains of S. pyogenes, representing diverse disease-causing serotypes, have been published. The greatest genetic variation among these strains is attributed to numerous integrated prophage and prophage-like elements, encoding several virulence factors. A comparison of isogenic strains, differing in prophage content, would reveal the effects of these elements on streptococcal pathogenesis. However, curing strains of prophage is often difficult and sometimes unattainable. We have applied a novel counter-selection approach to identify rare S. pyogenes mutants spontaneously cured of select prophage. To accomplish this, we first inserted a two-gene cassette containing a gene for kanamycin resistance (KanR) and the rpsL wild-type gene, responsible for dominant streptomycin sensitivity (SmS), into a targeted prophage on the chromosome of a streptomycin resistant (SmR) mutant of S. pyogenes strain SF370. We then applied antibiotic counter-selection for the re-establishment of the KanS/SmR phenotype to select for isolates cured of targeted prophage. This methodology allowed for the precise selection of spontaneous phage loss and restoration of the natural phage attB attachment sites for all four prophage-like elements in this S. pyogenes chromosome. Overall, 15 mutants were constructed that encompassed every permutation of phage knockout as well as a mutant strain, named CEM1ΔΦ, completely cured of all bacteriophage elements (a ~10% loss of the genome); the only reported S. pyogenes strain free of prophage-like elements. We compared CEM1ΔΦ to the WT strain by analyzing differences in secreted DNase activity, as well as lytic and lysogenic potential. These mutant strains should allow for the direct examination of bacteriophage relationships within S. pyogenes and

  18. Targeted Curing of All Lysogenic Bacteriophage from Streptococcus pyogenes Using a Novel Counter-selection Technique.

    PubMed

    Euler, Chad W; Juncosa, Barbara; Ryan, Patricia A; Deutsch, Douglas R; McShan, W Michael; Fischetti, Vincent A

    2016-01-01

    Streptococcus pyogenes is a human commensal and a bacterial pathogen responsible for a wide variety of human diseases differing in symptoms, severity, and tissue tropism. The completed genome sequences of >37 strains of S. pyogenes, representing diverse disease-causing serotypes, have been published. The greatest genetic variation among these strains is attributed to numerous integrated prophage and prophage-like elements, encoding several virulence factors. A comparison of isogenic strains, differing in prophage content, would reveal the effects of these elements on streptococcal pathogenesis. However, curing strains of prophage is often difficult and sometimes unattainable. We have applied a novel counter-selection approach to identify rare S. pyogenes mutants spontaneously cured of select prophage. To accomplish this, we first inserted a two-gene cassette containing a gene for kanamycin resistance (KanR) and the rpsL wild-type gene, responsible for dominant streptomycin sensitivity (SmS), into a targeted prophage on the chromosome of a streptomycin resistant (SmR) mutant of S. pyogenes strain SF370. We then applied antibiotic counter-selection for the re-establishment of the KanS/SmR phenotype to select for isolates cured of targeted prophage. This methodology allowed for the precise selection of spontaneous phage loss and restoration of the natural phage attB attachment sites for all four prophage-like elements in this S. pyogenes chromosome. Overall, 15 mutants were constructed that encompassed every permutation of phage knockout as well as a mutant strain, named CEM1ΔΦ, completely cured of all bacteriophage elements (a ~10% loss of the genome); the only reported S. pyogenes strain free of prophage-like elements. We compared CEM1ΔΦ to the WT strain by analyzing differences in secreted DNase activity, as well as lytic and lysogenic potential. These mutant strains should allow for the direct examination of bacteriophage relationships within S. pyogenes and

  19. Comparative growth, cross stress resistance, transcriptomics of Streptococcus pyogenes cultured under low shear modeled microgravity and normal gravity

    PubMed Central

    Kalpana, Duraisamy; Im, Chanki; Lee, Yang Soo

    2015-01-01

    Streptococcus pyogenes is commonly found on pharynx, mouth and rarely on skin, lower gastrointestinal tract. It is a potential pathogen causing tonsillitis, pneumonia, endocarditis. The present study was undertaken to study the effects of low shear modeled microgravity on growth, morphology, antibiotic resistance, cross-stress resistance to various stresses and alteration in gene expression of S. pyogenes. The growth analysis performed using UV–Visible spectroscopy indicated decrease in growth of S. pyogenes under low shear modeled microgravity. Morphological analysis by Bio-transmission electron microscopy (TEM), Bio-scanning electron microscopy (SEM) did not reveal much difference between normal and low shear modeled microgravity grown S. pyogenes. The sensitivity of S. pyogenes to antibiotics ampicillin, penicillin, streptomycin, kanamycin, hygromycin, rifampicin indicates that the bacterium is resistant to hygromycin. Further S. pyogenes cultured under low shear modeled microgravity was found to be more sensitive to ampicillin and rifampicin as compared with normal gravity grown S. pyogenes. The bacteria were tested for the acid, osmotic, temperature and oxidative cross stress resistances. The gene expression of S. pyogenes under low shear modeled microgravity analyzed by microarray revealed upregulation of 26 genes and down regulation of 22 genes by a fold change of 1.5. PMID:26858535

  20. Zinc disrupts central carbon metabolism and capsule biosynthesis in Streptococcus pyogenes

    PubMed Central

    Ong, Cheryl-lynn Y.; Walker, Mark J.; McEwan, Alastair G.

    2015-01-01

    Neutrophils release free zinc to eliminate the phagocytosed bacterial pathogen Streptococcus pyogenes (Group A Streptococcus; GAS). In this study, we investigated the mechanisms underpinning zinc toxicity towards this human pathogen, responsible for diseases ranging from pharyngitis and impetigo, to severe invasive infections. Using the globally-disseminated M1T1 GAS strain, we demonstrate that zinc stress impairs glucose metabolism through the inhibition of the glycolytic enzymes phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase. In the presence of zinc, a metabolic shift to the tagatose-6-phosphate pathway allows conversion of D-galactose to dihydroxyacetone phosphate and glyceraldehyde phosphate, partially bypassing impaired glycolytic enzymes to generate pyruvate. Additionally, zinc inhibition of phosphoglucomutase results in decreased capsule biosynthesis. These data indicate that zinc exerts it toxicity via mechanisms that inhibit both GAS central carbon metabolism and virulence pathways. PMID:26028191

  1. Zinc disrupts central carbon metabolism and capsule biosynthesis in Streptococcus pyogenes.

    PubMed

    Ong, Cheryl-lynn Y; Walker, Mark J; McEwan, Alastair G

    2015-01-01

    Neutrophils release free zinc to eliminate the phagocytosed bacterial pathogen Streptococcus pyogenes (Group A Streptococcus; GAS). In this study, we investigated the mechanisms underpinning zinc toxicity towards this human pathogen, responsible for diseases ranging from pharyngitis and impetigo, to severe invasive infections. Using the globally-disseminated M1T1 GAS strain, we demonstrate that zinc stress impairs glucose metabolism through the inhibition of the glycolytic enzymes phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase. In the presence of zinc, a metabolic shift to the tagatose-6-phosphate pathway allows conversion of D-galactose to dihydroxyacetone phosphate and glyceraldehyde phosphate, partially bypassing impaired glycolytic enzymes to generate pyruvate. Additionally, zinc inhibition of phosphoglucomutase results in decreased capsule biosynthesis. These data indicate that zinc exerts it toxicity via mechanisms that inhibit both GAS central carbon metabolism and virulence pathways. PMID:26028191

  2. Overexpression and Enzymatic Assessment of Antigenic Fragments of Hyaluronidase Recombinant Protein From Streptococcus pyogenes

    PubMed Central

    Sadoogh Abbasian, Shabnam; Ghaznavi Rad, Ehsanollah; Akbari, Neda; Zolfaghari, Mohammad Reza; pakzad, Iraj; Abtahi, Hamid

    2014-01-01

    Background: Hyaluronidase catalyzes the hydrolysis of hyaluronan polymers to N-acetyl-D-glucosamine and D-glucuronic acid. This enzyme is a dimer of identical subunits. Hyaluronidase has different pharmaceutical and medical applications. Previously, we produced a recombinant hyaluronidase antigenic fragment of Streptococcus pyogenes. Objectives: This study aimed to improve the protein production and purity of hyaluronidase recombinant protein from S. pyogenes. In addition, the enzymatic activity of this protein was investigated. Materials and Methods: The expression of hyaluronidase antigenic fragments was optimized using IPTG concentration, time of induction, temperature, culture, and absorbance of 0.6-0.8-1 at 600 nm. Afterwards, the expressed proteins were purified and the enzymatic activity was assessed by turbid metric method. Results: Data indicated that maximum protein is produced in OD = 0.8, 0.5 mM Isopropyl β-D-1-thiogalactopyranoside (IPTG), 37ºC, NB 1.5x, without glucose, incubated for overnight. The enzymatic activity of the recombinant protein was similar to the commercial form of hyaluronidase. Conclusions: The results showed that an antigenic fragment of the recombinant hyaluronidase protein from S. pyogenes has a considerable enzymatic activity. It can be suggested to use it for medical purposes. In addition, applications of bioinformatics software would facilitate the production of a smaller protein with same antigenic properties and enzymatic activity. PMID:25789122

  3. Streptococcus pyogenes Pneumonia in Adults: Clinical Presentation and Molecular Characterization of Isolates 2006-2015

    PubMed Central

    Tamayo, Esther; Montes, Milagrosa; Vicente, Diego; Pérez-Trallero, Emilio

    2016-01-01

    Introduction In the preantibiotic era Streptococcus pyogenes was a common cause of severe pneumonia but currently, except for postinfluenza complications, it is not considered a common cause of community-acquired pneumonia in adults. Aim and Material and Methods This study aimed to identify current clinical episodes of S. pyogenes pneumonia, its relationship with influenza virus circulation and the genotypes of the involved isolates during a decade in a Southern European region (Gipuzkoa, northern Spain). Molecular analysis of isolates included emm, multilocus-sequence typing, and superantigen profile determination. Results Forty episodes were detected (annual incidence 1.1 x 100,000 inhabitants, range 0.29–2.29). Thirty-seven episodes were community-acquired, 21 involved an invasive infection and 10 developed STSS. The associated mortality rate was 20%, with half of the patients dying within 24 hours after admission. Influenza coinfection was confirmed in four patients and suspected in another. The 52.5% of episodes occurred outside the influenza seasonal epidemic. The 67.5% of affected persons were elderly individuals and adults with severe comorbidities, although 13 patients had no comorbidities, 2 of them had a fatal outcome. Eleven clones were identified, the most prevalent being emm1/ST28 (43.6%) causing the most severe cases. Conclusions S. pyogenes pneumonia had a continuous presence frequently unrelated to influenza infection, being rapidly fatal even in previously healthy individuals. PMID:27027618

  4. Streptococcus pyogenes Triggers Activation of the Human Contact System by Streptokinase

    PubMed Central

    Nitzsche, Ramona; Rosenheinrich, Maik; Kreikemeyer, Bernd

    2015-01-01

    Severe invasive infectious diseases remain a major and life-threatening health problem. In serious cases, a systemic activation of the coagulation cascade is a critical complication that is associated with high mortality rates. We report here that streptokinase, a group A streptococcal plasminogen activator, triggers the activation of the human contact system. Activation of contact system factors at the surface of the Streptococcus pyogenes serotype M49 is dependent on streptokinase and plasminogen. Our results also show that secreted streptokinase is an efficient contact system activator, independent from a contact surface. This results in the processing of high-molecular-weight kininogen and the release of bradykinin, a potent vascular mediator. We further investigated whether the ability of 50 different clinical S. pyogenes isolates to activate the contact system is associated with an invasive phenotype. The data reveal that isolates from invasive infections trigger an activation of the contact system more potently than strains isolated from noninvasive infections. The present study gives new insights into the mechanisms by which S. pyogenes triggers the human contact system and stresses the function of soluble and surface located plasmin exploited as a group A streptococcal virulence factor through the action of streptokinase. PMID:25987706

  5. Streptococcus pyogenes and re-emergence of scarlet fever as a public health problem

    PubMed Central

    Wong, Samson SY; Yuen, Kwok-Yung

    2012-01-01

    Explosive outbreaks of infectious diseases occasionally occur without immediately obvious epidemiological or microbiological explanations. Plague, cholera and Streptococcus pyogenes infection are some of the epidemic-prone bacterial infections. Besides epidemiological and conventional microbiological methods, the next-generation gene sequencing technology permits prompt detection of genomic and transcriptomic profiles associated with invasive phenotypes. Horizontal gene transfer due to mobile genetic elements carrying virulence factors and antimicrobial resistance, or mutations associated with the two component CovRS operon are important bacterial factors conferring survival advantage or invasiveness. The high incidence of scarlet fever in children less than 10 years old suggests that the lack of protective immunity is an important host factor. A high population density, overcrowded living environment and a low yearly rainfall are environmental factors contributing to outbreak development. Inappropriate antibiotic use is not only ineffective for treatment, but may actually drive an epidemic caused by drug-resistant strains and worsen patient outcomes by increasing the bacterial density at the site of infection and inducing toxin production. Surveillance of severe S. pyogenes infection is important because it can complicate concurrent chickenpox and influenza. Concomitant outbreaks of these two latter infections with a highly virulent and drug-resistant S. pyogenes strain can be disastrous. PMID:26038416

  6. Rgg influences the expression of multiple regulatory loci to coregulate virulence factor expression in Streptococcus pyogenes.

    PubMed

    Chaussee, Michael S; Sylva, Gail L; Sturdevant, Daniel E; Smoot, Laura M; Graham, Morag R; Watson, Robert O; Musser, James M

    2002-02-01

    The human pathogen Streptococcus pyogenes secretes many proteins to the cell wall and extracellular environment that contribute to virulence. Rgg regulates the expression of several exoproteins including a cysteine protease (SPE B), a nuclease (MF-1), a putative nuclease (MF-3), and autolysin. The functional heterogeneity of Rgg-regulated exoproteins and the lack of a conserved regulatory motif in the promoter regions of the genes suggested that Rgg interacts with additional regulatory networks to influence gene expression. DNA microarrays were used to test this hypothesis by comparing genomewide transcript profiles of S. pyogenes NZ131 and isogenic derivative NZ131 rgg during the exponential phase of growth. Transcripts of known and putative virulence-associated genes were more abundant in the rgg mutant, including emm, scpA, orfX, scl1, hasAB, slo, sagA, ska, speH, grab, mac, mf-1, and mf-3. Increased transcription of emm, scpA, and orfX in the rgg mutant was associated with increased production of the corresponding proteins. Differences in the expression of virulence-associated genes were associated with changes in the expression of several regulatory genes, including mga, sagA, csrRS, and fasBCA. The results show that Rgg influences the expression of multiple regulatory networks to coregulate virulence factor expression in S. pyogenes. PMID:11796609

  7. Molecular analysis of Streptococcus pyogenes strains isolated from Chinese children with pharyngitis.

    PubMed

    Chang, Hesheng; Shen, Xuzhuang; Huang, Guoying; Fu, Zhou; Zheng, Yuejie; Wang, Libo; Li, Chengrong; Liu, Lan; Shen, Ying; Liu, Xiaorong; Yang, Yonghong

    2011-02-01

    Streptococcus pyogenes is an important gram-positive bacterial pathogen that causes various human diseases, of which streptococcal pharyngitis is the most common. In this work, a total of 185 S. pyogenes isolated from Chinese children with pharyngitis was analyzed by superantigen (SAg) genes, emm genotyping, and pulsed-field gel electrophoresis (PFGE). Fifty-eight (31.4%) isolates were also typed by multilocus sequence typing (MLST). The results indicate that most of the emm1 isolates possessed speA (88.5%) and speJ (83.6%), and few isolates possessed speI gene (13.1%). In contrast, none of the emm12-type isolates possessed speJ; few isolates possessed speA (5.2%); and most of the isolates possessed speI (91.7%). PFGE analysis revealed 25 different clusters, and MLST was performed for 2 predominant emm-type isolates; emm12 isolates belonged to ST36 while emm1 isolates belonged to ST28. As far as this collection is concerned, emm1 and emm12 are the prevalent genotypes among S. pyogenes strains associated with children's pharyngitis in China. Most of the pharyngitis strains can be covered by a 26-valent vaccine. A strong correspondence is found only in the direction of emm type for both SAg profiles and PFGE types but not in the reverse direction. PMID:21251553

  8. 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 Central

    Jacob, Kristin M.; Spilker, Theodore; LiPuma, John J.; Dawid, Suzanne R.

    2016-01-01

    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%. PMID:26988046

  9. Identification of Streptococcus pyogenes – Phenotypic Tests vs Molecular Assay (spy1258PCR): A Comparative Study

    PubMed Central

    Abraham, Tintu

    2016-01-01

    Introduction Traditionally Group A Streptococcus pyogenes (GAS) is differentiated from other beta haemolytic streptococci (BHS) by certain presumptive tests such as bacitracin sensitivity and production of Pyrollidonyl Aryl Sulfatase (PYR). The phenotypic and genotypic confirmatory tests are Lancefield grouping for cell wall carbohydrate antigen and PCR for spy1258 gene respectively. Reliance on presumptive tests alone may lead to misidentification of isolates. Aim To compare the predictive values of routine phenotypic tests with spy1258 PCR for the identification of Streptococcus pyogenes. Materials and Methods This comparative analytical study was carried out in the Department of Microbiology, JIPMER, Puducherry, over a period of 18 months (1st November 2013 to 30th April 2015). Two hundred and six consecutive BHS isolates from various clinical samples were subjected to phenotypic tests such as bacitracin sensitivity, PYR test and Lancefield grouping. The results were compared with spy1258 PCR which was considered 95 the confirmatory test for identification. Results The sensitivity and specificity of phenotypic tests were as follows; Susceptibility to bacitracin – 95.42%, 70.96%, PYR test – 95.42%, 77.41%, Lancefield grouping- 97.71%, 80.64%. Conclusion Clinical laboratories should not depend on bacitracin sensitivity as a single presumptive test for the routine identification of GAS but should use supplemental tests such as PYR test or latex agglutination test and for best results use spy1258 PCR.

  10. Lactobacilli Interfere with Streptococcus pyogenes Hemolytic Activity and Adherence to Host Epithelial Cells.

    PubMed

    Saroj, Sunil D; Maudsdotter, Lisa; Tavares, Raquel; Jonsson, Ann-Beth

    2016-01-01

    Streptococcus pyogenes [Group A streptococcus (GAS)], a frequent colonizer of the respiratory tract mucosal surface, causes a variety of human diseases, ranging from pharyngitis to the life-threatening streptococcal toxic shock-like syndrome. Lactobacilli have been demonstrated to colonize the respiratory tract. In this study, we investigated the interference of lactobacilli with the virulence phenotypes of GAS. The Lactobacillus strains L. rhamnosus Kx151A1 and L. reuteri PTA-5289, but not L. salivarius LMG9477, inhibited the hemolytic activity of S. pyogenes S165. The inhibition of hemolytic activity was attributed to a decrease in the production of streptolysin S (SLS). Conditioned medium (CM) from the growth of L. rhamnosus Kx151A1 and L. reuteri PTA-5289 was sufficient to down-regulate the expression of the sag operon, encoding SLS. The Lactobacillus strains L. rhamnosus Kx151A1, L. reuteri PTA-5289, and L. salivarius LMG9477 inhibited the initial adherence of GAS to host epithelial cells. Intriguingly, competition with a combination of Lactobacillus species reduced GAS adherence to host cells most efficiently. The data suggest that an effector molecule released from certain Lactobacillus strains attenuates the production of SLS at the transcriptional level and that combinations of Lactobacillus strains may protect the pharyngeal mucosa more efficiently from the initial colonization of GAS. The effector molecules released from Lactobacillus strains affecting the virulence phenotypes of pathogens hold potential in the development of a new generation of therapeutics. PMID:27524981

  11. Lactobacilli Interfere with Streptococcus pyogenes Hemolytic Activity and Adherence to Host Epithelial Cells

    PubMed Central

    Saroj, Sunil D.; Maudsdotter, Lisa; Tavares, Raquel; Jonsson, Ann-Beth

    2016-01-01

    Streptococcus pyogenes [Group A streptococcus (GAS)], a frequent colonizer of the respiratory tract mucosal surface, causes a variety of human diseases, ranging from pharyngitis to the life-threatening streptococcal toxic shock-like syndrome. Lactobacilli have been demonstrated to colonize the respiratory tract. In this study, we investigated the interference of lactobacilli with the virulence phenotypes of GAS. The Lactobacillus strains L. rhamnosus Kx151A1 and L. reuteri PTA-5289, but not L. salivarius LMG9477, inhibited the hemolytic activity of S. pyogenes S165. The inhibition of hemolytic activity was attributed to a decrease in the production of streptolysin S (SLS). Conditioned medium (CM) from the growth of L. rhamnosus Kx151A1 and L. reuteri PTA-5289 was sufficient to down-regulate the expression of the sag operon, encoding SLS. The Lactobacillus strains L. rhamnosus Kx151A1, L. reuteri PTA-5289, and L. salivarius LMG9477 inhibited the initial adherence of GAS to host epithelial cells. Intriguingly, competition with a combination of Lactobacillus species reduced GAS adherence to host cells most efficiently. The data suggest that an effector molecule released from certain Lactobacillus strains attenuates the production of SLS at the transcriptional level and that combinations of Lactobacillus strains may protect the pharyngeal mucosa more efficiently from the initial colonization of GAS. The effector molecules released from Lactobacillus strains affecting the virulence phenotypes of pathogens hold potential in the development of a new generation of therapeutics. PMID:27524981

  12. ELECTROPHORETIC SEPARATION OF CONSTITUENTS OF PARTIALLY PURIFIED M PROTEIN OF STREPTOCOCCUS PYOGENES

    PubMed Central

    Pierce, William A.

    1964-01-01

    Pierce, William A., Jr. (Tulane University, New Orleans, La.). Electrophoretic separation of constituents of partially purified M protein of Streptococcus pyogenes. J. Bacteriol. 88:912–921. 1964.—Partially purified M protein of a group A, type 12 strain of Streptococcus pyogenes was studied by use of chemical, electrophoretic, and immunological techniques. It was demonstrated in immunodiffusion tests that the antigen contains multiple precipitating components. The type-specific antigen was identified, and evidence was presented that, in some instances at least, the cross-reactions observed between this type 12 M protein and heterologous antisera in immunodiffusion tests involve contaminating antigens rather than the component which precipitates with adsorbed homologous-typing antiserum. In passive hemagglutination tests where M protein was adsorbed to tanned sheep erythrocytes, it was found that antisera suitably adsorbed to show good specificity in capillary precipitin tests nevertheless still contain cross-reactive antibodies which are detectable by this more sensitive technique. Electrophoresis on starch paste separates some of the components of partially purified M protein, so that a fraction can be obtained which has fewer precipitating antigens, as determined in immunodiffusion tests, and which is less cross-reactive in passive hemagglutination tests with heterologous unadsorbed antistreptococcal antisera. PMID:14219054

  13. Cysteine Proteinase from Streptococcus pyogenes Enables Evasion of Innate Immunity via Degradation of Complement Factors*

    PubMed Central

    Honda-Ogawa, Mariko; Ogawa, Taiji; Terao, Yutaka; Sumitomo, Tomoko; Nakata, Masanobu; Ikebe, Kazunori; Maeda, Yoshinobu; Kawabata, Shigetada

    2013-01-01

    Streptococcus pyogenes is an important human pathogen that causes invasive diseases such as necrotizing fasciitis, sepsis, and streptococcal toxic shock syndrome. We investigated the function of a major cysteine protease from S. pyogenes that affects the amount of C1-esterase inhibitor (C1-INH) and other complement factors and aimed to elucidate the mechanism involved in occurrence of streptococcal toxic shock syndrome from the aspect of the complement system. First, we revealed that culture supernatant of a given S. pyogenes strain and recombinant SpeB degraded the C1-INH. Then, we determined the N-terminal sequence of the C1-INH fragment degraded by recombinant SpeB. Interestingly, the region containing one of the identified cleavage sites is not present in patients with C1-INH deficiency. Scanning electron microscopy of the speB mutant incubated in human serum showed the abnormal superficial architecture and irregular oval structure. Furthermore, unlike the wild-type strain, that mutant strain showed lower survival capacity than normal as compared with heat-inactivated serum, whereas it had a significantly higher survival rate in serum without the C1-INH than in normal serum. Also, SpeB degraded multiple complement factors and the membrane attack complex. Flow cytometric analyses revealed deposition of C9, one of the components of membrane the attack complex, in greater amounts on the surface of the speB mutant, whereas lower amounts of C9 were bound to the wild-type strain surface. These results suggest that SpeB can interrupt the human complement system via degrading the C1-INH, thus enabling S. pyogenes to evade eradication in a hostile environment. PMID:23589297

  14. Acquisition of regulators of complement activation by Streptococcus pyogenes serotype M1.

    PubMed

    Pandiripally, Vinod; Gregory, Eugene; Cue, David

    2002-11-01

    Opsonization of bacteria by complement proteins is an important component of the immune response. The pathogenic bacterium Streptococcus pyogenes has evolved multiple mechanisms for the evasion of complement-mediated opsonization. One mechanism involves the binding of human regulators of complement activation such as factor H (FH) and FH-like protein 1 (FHL-1). Acquisition of these regulatory proteins can limit deposition of the opsonin C3b on bacteria, thus decreasing the pathogen's susceptibility to phagocytosis. Binding of complement regulatory proteins by S. pyogenes has previously been attributed to the streptococcal M and M-like proteins. Here, we report that the S. pyogenes cell surface protein Fba can mediate binding of FH and FHL-1. We constructed mutant derivatives of S. pyogenes that lack Fba, M1 protein, or both proteins and assayed the strains for FH binding, susceptibility to phagocytosis, and C3 deposition. Fba expression was found to be sufficient for binding of purified FH as well as for binding of FH and FHL-1 from human plasma. Plasma adsorption experiments also revealed that M1(+) Fba(+) streptococci preferentially bind FHL-1, whereas M1(-) Fba(+) streptococci have similar affinities for FH and FHL-1. Fba was found to contribute to the survival of streptococci incubated with human blood and to inhibit C3 deposition on bacterial cells. Streptococci harvested from log-phase cultures readily bound FH, but binding was greatly reduced for bacteria obtained from stationary-phase cultures. Bacteria cultured in the presence of the protease inhibitor E64 maintained FH binding activity in stationary phase, suggesting that Fba is removed from the cell surface via proteolysis. Western analyses confirmed that E64 stabilizes cell surface expression of Fba. These data indicate that Fba is an antiopsonic, antiphagocytic protein that may be regulated by cell surface proteolysis. PMID:12379699

  15. Acquisition of Regulators of Complement Activation by Streptococcus pyogenes Serotype M1

    PubMed Central

    Pandiripally, Vinod; Gregory, Eugene; Cue, David

    2002-01-01

    Opsonization of bacteria by complement proteins is an important component of the immune response. The pathogenic bacterium Streptococcus pyogenes has evolved multiple mechanisms for the evasion of complement-mediated opsonization. One mechanism involves the binding of human regulators of complement activation such as factor H (FH) and FH-like protein 1 (FHL-1). Acquisition of these regulatory proteins can limit deposition of the opsonin C3b on bacteria, thus decreasing the pathogen's susceptibility to phagocytosis. Binding of complement regulatory proteins by S. pyogenes has previously been attributed to the streptococcal M and M-like proteins. Here, we report that the S. pyogenes cell surface protein Fba can mediate binding of FH and FHL-1. We constructed mutant derivatives of S. pyogenes that lack Fba, M1 protein, or both proteins and assayed the strains for FH binding, susceptibility to phagocytosis, and C3 deposition. Fba expression was found to be sufficient for binding of purified FH as well as for binding of FH and FHL-1 from human plasma. Plasma adsorption experiments also revealed that M1+ Fba+ streptococci preferentially bind FHL-1, whereas M1− Fba+ streptococci have similar affinities for FH and FHL-1. Fba was found to contribute to the survival of streptococci incubated with human blood and to inhibit C3 deposition on bacterial cells. Streptococci harvested from log-phase cultures readily bound FH, but binding was greatly reduced for bacteria obtained from stationary-phase cultures. Bacteria cultured in the presence of the protease inhibitor E64 maintained FH binding activity in stationary phase, suggesting that Fba is removed from the cell surface via proteolysis. Western analyses confirmed that E64 stabilizes cell surface expression of Fba. These data indicate that Fba is an antiopsonic, antiphagocytic protein that may be regulated by cell surface proteolysis. PMID:12379699

  16. 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). PMID:26014938

  17. 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. PMID:22567013

  18. Clinical and microbiological characteristics of severe Streptococcus pyogenes disease in Europe.

    PubMed

    Luca-Harari, Bogdan; Darenberg, Jessica; Neal, Shona; Siljander, Tuula; Strakova, Lenka; Tanna, Asha; Creti, Roberta; Ekelund, Kim; Koliou, Maria; Tassios, Panayotis T; van der Linden, Mark; Straut, Monica; Vuopio-Varkila, Jaana; Bouvet, Anne; Efstratiou, Androulla; Schalén, Claes; Henriques-Normark, Birgitta; Jasir, Aftab

    2009-04-01

    In an attempt to compare the epidemiology of severe Streptococcus pyogenes infection within Europe, prospective data were collected through the Strep-EURO program. Surveillance for severe cases of S. pyogenes infection diagnosed during 2003 and 2004 was undertaken in 11 countries across Europe by using a standardized case definition and questionnaire. Patient data as well as bacterial isolates were collected and characterized by T and M/emm typing, and selected strains were analyzed for the presence of superantigen genes. Data were analyzed to compare the clinical and microbiological patterns of the infections across the participating countries. A total of 4,353 isolates were collected from 5,521 cases with severe S. pyogenes infections who were identified. A wide diversity of M/emm types (n = 104) was found among the S. pyogenes clinical isolates, but the M/emm type distribution varied broadly between participating countries. The 10 most predominant M/emm types were M/emm type 1 (M/emm1), M/emm28, M/emm3, M/emm89, M/emm87, M/emm12, M/emm4, M/emm83, M/emm81, and M/emm5, in descending order. A correlation was found between some specific disease manifestations, the age of the patients, and the emm types. Although streptococcal toxic shock syndrome and necrotizing fasciitis were caused by a large number of types, they were particularly associated with M/emm1 and M/emm3. The emm types included in the 26-valent vaccine under development were generally well represented in the present material; 16 of the vaccine types accounted for 69% of isolates. The Strep-EURO collaborative program has contributed to enhancement of the knowledge of the spread of invasive disease caused by S. pyogenes within Europe and encourages future surveillance by the notification of cases and the characterization of strains, which are important for vaccination strategies and other health care issues. PMID:19158266

  19. Clinical and Microbiological Characteristics of Severe Streptococcus pyogenes Disease in Europe▿

    PubMed Central

    Luca-Harari, Bogdan; Darenberg, Jessica; Neal, Shona; Siljander, Tuula; Strakova, Lenka; Tanna, Asha; Creti, Roberta; Ekelund, Kim; Koliou, Maria; Tassios, Panayotis T.; van der Linden, Mark; Straut, Monica; Vuopio-Varkila, Jaana; Bouvet, Anne; Efstratiou, Androulla; Schalén, Claes; Henriques-Normark, Birgitta; Jasir, Aftab

    2009-01-01

    In an attempt to compare the epidemiology of severe Streptococcus pyogenes infection within Europe, prospective data were collected through the Strep-EURO program. Surveillance for severe cases of S. pyogenes infection diagnosed during 2003 and 2004 was undertaken in 11 countries across Europe by using a standardized case definition and questionnaire. Patient data as well as bacterial isolates were collected and characterized by T and M/emm typing, and selected strains were analyzed for the presence of superantigen genes. Data were analyzed to compare the clinical and microbiological patterns of the infections across the participating countries. A total of 4,353 isolates were collected from 5,521 cases with severe S. pyogenes infections who were identified. A wide diversity of M/emm types (n = 104) was found among the S. pyogenes clinical isolates, but the M/emm type distribution varied broadly between participating countries. The 10 most predominant M/emm types were M/emm type 1 (M/emm1), M/emm28, M/emm3, M/emm89, M/emm87, M/emm12, M/emm4, M/emm83, M/emm81, and M/emm5, in descending order. A correlation was found between some specific disease manifestations, the age of the patients, and the emm types. Although streptococcal toxic shock syndrome and necrotizing fasciitis were caused by a large number of types, they were particularly associated with M/emm1 and M/emm3. The emm types included in the 26-valent vaccine under development were generally well represented in the present material; 16 of the vaccine types accounted for 69% of isolates. The Strep-EURO collaborative program has contributed to enhancement of the knowledge of the spread of invasive disease caused by S. pyogenes within Europe and encourages future surveillance by the notification of cases and the characterization of strains, which are important for vaccination strategies and other health care issues. PMID:19158266

  20. Geoepidemiological hints about Streptococcus pyogenes strains in relationship with acute rheumatic fever.

    PubMed

    Esposito, Susanna; Bianchini, Sonia; Fastiggi, Michele; Fumagalli, Monica; Andreozzi, Laura; Rigante, Donato

    2015-07-01

    Group A Streptococcus (GAS) strains are lately classified on the basis of sequence variations in the emm gene encoding the M protein, but despite the high number of distinct emm genotypes, the spectrum of phenotypes varying from invasive suppurative to non-suppurative GAS-related disorders has still to be defined. The relationship of GAS types with the uprising of acute rheumatic fever (ARF), a multisystemic disease caused by misdirected anti-GAS response in predisposed people, is also obscure. Studies published over the last 15 years were retrieved from PubMed using the keywords: "Streptococcus pyogenes" or "group A Streptococcus" and "acute rheumatic fever": the prevalence of peculiar emm types across different countries of the world is highly variable, depending on research designs, year of observation, country involved, patients' age, and gender. Most studies revealed that a relatively small number of specific emm/M protein types can be considered "rheumatogenic", as potentially characterized by the possibility of inducing ARF, with remarkable differences between developing and developed countries. The association between emm types and post-streptococcal manifestations is challenging, however surveillance of disease-causing variants in a specific community with high rate of ARF should be reinforced with the final goal of developing a potential primary prophylaxis against GAS infections. PMID:25772310

  1. Characterization and genome sequencing of a novel bacteriophage infecting Streptococcus agalactiae with high similarity to a phage from Streptococcus pyogenes.

    PubMed

    Bai, Qinqin; Zhang, Wei; Yang, Yongchun; Tang, Fang; Nguyen, Xuanhoa; Liu, Guangjin; Lu, Chengping

    2013-08-01

    A novel bacteriophage, JX01, specifically infecting bovine Streptococcus agalactiae was isolated from milk of mastitis-affected cattle. The phage morphology showed that JX01 belongs to the family Siphoviridae, and this phage demonstrated a broad host range. Microbiological characterization demonstrated that nearly 90 % of JX01 phage particles were adsorbed after 2.5 min of incubation, that the burst size was 20 virions released per infected host cell, and that there was a latent period of 30 min. JX01 was thermal sensitive and showed acid and alkaline resistance (pH 3-11). The genome of JX01 was found to consist of a linear, double-stranded 43,028-bp DNA molecule with a GC content of 36.81 % and 70 putative open reading frames (ORFs) plus one tRNA. Comparative genome analysis revealed high similarity between JX01 and the prophage 315.2 of Streptococcus pyogenes. PMID:23515875

  2. Genome Sequence of the Uncommon Streptococcus pyogenes M/emm66 Strain STAB13021, Isolated from Clonal Clustered Cases in French Brittany

    PubMed Central

    Meygret, Alexandra; Vincent, Pascal; Moullec, Séverine; Nacazume, Jessica; Adnani, Yahia; Lavenier, Dominique

    2016-01-01

    Here, we announce the complete annotated genome sequence of the invasive Streptococcus pyogenes strain M/emm66, isolated in 2013 from a subcutaneous abscess in new clustered cases in French Brittany. PMID:27445380

  3. Genome Sequence of the Uncommon Streptococcus pyogenes M/emm66 Strain STAB13021, Isolated from Clonal Clustered Cases in French Brittany.

    PubMed

    Meygret, Alexandra; Vincent, Pascal; Moullec, Séverine; Nacazume, Jessica; Adnani, Yahia; Lavenier, Dominique; Kayal, Samer; Faili, Ahmad

    2016-01-01

    Here, we announce the complete annotated genome sequence of the invasive Streptococcus pyogenes strain M/emm66, isolated in 2013 from a subcutaneous abscess in new clustered cases in French Brittany. PMID:27445380

  4. Streptococcus pyogenes Malate Degradation Pathway Links pH Regulation and Virulence

    PubMed Central

    Paluscio, Elyse

    2015-01-01

    The ability of Streptococcus pyogenes to infect different niches within its human host most likely relies on its ability to utilize alternative carbon sources. In examining this question, we discovered that all sequenced S. pyogenes strains possess the genes for the malic enzyme (ME) pathway, which allows malate to be used as a supplemental carbon source for growth. ME is comprised of four genes in two adjacent operons, with the regulatory two-component MaeKR required for expression of genes encoding a malate permease (maeP) and malic enzyme (maeE). Analysis of transcription indicated that expression of maeP and maeE is induced by both malate and low pH, and induction in response to both cues is dependent on the MaeK sensor kinase. Furthermore, both maePE and maeKR are repressed by glucose, which occurs via a CcpA-independent mechanism. Additionally, malate utilization requires the PTS transporter EI enzyme (PtsI), as a PtsI– mutant fails to express the ME genes and is unable to utilize malate. Virulence of selected ME mutants was assessed in a murine model of soft tissue infection. MaeP–, MaeK–, and MaeR– mutants were attenuated for virulence, whereas a MaeE– mutant showed enhanced virulence compared to that of the wild type. Taken together, these data show that ME contributes to S. pyogenes' carbon source repertory, that malate utilization is a highly regulated process, and that a single regulator controls ME expression in response to diverse signals. Furthermore, malate uptake and utilization contribute to the adaptive pH response, and ME can influence the outcome of infection. PMID:25583521

  5. Mutation of luxS affects growth and virulence factor expression in Streptococcus pyogenes.

    PubMed

    Lyon, W R; Madden, J C; Levin, J C; Stein, J L; Caparon, M G

    2001-10-01

    Adaptive responses of bacteria that involve sensing the presence of other bacteria are often critical for proliferation and the expression of virulence characteristics. The autoinducer II (AI-2) pathway has recently been shown to be a mechanism for sensing other bacteria that is highly conserved among diverse bacterial species, including Gram-positive pathogens. However, a role for this pathway in the regulation of virulence factors in Gram-positive pathogens has yet to be established. In this study, we have inactivated luxS, an essential component of the AI-2 pathway, in the Gram-positive pathogen Streptococcus pyogenes. Analyses of the resulting mutants revealed the aberrant expression of several virulence properties that are regulated in response to growth phase, including enhanced haemolytic activity, and a dramatic reduction in the expression of secreted proteolytic activity. This latter defect was associated with a reduced ability to secrete and process the precursor of the cysteine protease (SpeB) as well as a difference in the timing of expression of the protease. Enhanced haemolytic activity of the luxS strain was also shown to be linked with an increased expression of the haemolysin S-associated gene sagA. Disruptions of luxS in these mutants also produced a media-dependent growth defect. Finally, an allelic replacement analysis of an S. pyogenes strain with a naturally occurring insertion of IS1239 in luxS suggested a mechanism for modulation of virulence during infection. Results from this study suggest that luxS makes an important contribution to the regulation of S. pyogenes virulence factors. PMID:11679074

  6. Synthesis of "group polysaccharide" by membranes from Streptococcus pyogenes and its stabilized L-form.

    PubMed Central

    Reusch, V M; Panos, C

    1977-01-01

    Rhamnose and N-acetylglucosamine (GlcNAc) are incorporated from thymidine 5'-diphosphorhamnose and uridine 5-diphospho-N-acetylglucosamine (UDPGlcNAc) into membrane fragments prepared from Streptococcus pyogenes but not into membrane fragements prepared from a stabilized L-form of this organism. Incorporation from TDPrhamnose is partially dependent upon UDPGlcNAc and vice versa. The oligomeric GlcNAc and rhamonose-containing products are easily extracted from membrane particles by sedimentation through detergent solutions. They are substantially extracted into methanol but not into chloroform-methanol (2:1). When product containing both radioactive rhamnose and GlcNAc is deacetylated and hydrolyzed briefy in acid, glucosaminyl rhamnose is obtained, byt not higher oligomers, suggesting that oligomer synthesis in vitro is terminated because unidentified wnzymatic requirements are not satisfied. The data are consistent with the assembly of group A-specific polysaccharide at the cellular membrane with participation of a lipoid anchor (acceptor) molecule. PMID:321425

  7. Mouse skin passage of Streptococcus pyogenes results in increased streptokinase expression and activity.

    PubMed

    Rezcallah, Myrna S; Boyle, Michael D P; Sledjeski, Darren D

    2004-02-01

    The plasminogen activator streptokinase has been proposed to be a key component of a complex mechanism that promotes skin invasion by Streptococcus pyogenes. This study was designed to compare ska gene message and protein levels in wild-type M1 serotype isolate 1881 and a more invasive variant recovered from the spleen of a lethally infected mouse. M1 isolates selected for invasiveness demonstrated enhanced levels of active plasminogen activator activity in culture. This effect was due to a combination of increased expression of the ska gene and decreased expression of the speB gene. The speB gene product, SpeB, was found to efficiently degrade streptokinase in vitro. PMID:14766914

  8. Scrum kidney: epidemic pyoderma caused by a nephritogenic Streptococcus pyogenes in a rugby team.

    PubMed

    Ludlam, H; Cookson, B

    1986-08-01

    In December, 1984, an outbreak of pyoderma affected five scrum players in the St Thomas' Hospital rugby team. The causative organism, Streptococcus pyogenes, was acquired during a match against a team experiencing an outbreak of impetigo, and was transmitted to two front row players of another team a week later, and to two girlfriends of affected St Thomas' players a month later. The strain was M-type 49, tetracycline-resistant, and virulent. It caused salpingitis in a girlfriend and acute glomerulonephritis in one rugby player. No case of subclinical glomerulonephritis was detected in eight patients with pyoderma. Screening of the St Thomas' Hospital team revealed four further cases of non-streptococcal skin infection, with evidence for contemporaneous spread of Staphylococcus aureus. Teams should not field players with sepsis, and it may be advisable to apply a skin antiseptic to traumatised skin after the match. PMID:2874337

  9. Towards scalable production of a collagen-like protein from Streptococcus pyogenes for biomedical applications

    PubMed Central

    2012-01-01

    Background Collagen has proved valuable as biomedical materials for a range of clinical applications, particularly in wound healing. It is normally produced from animal sources, such as from bovines, but concerns have emerged over transmission of diseases. Recombinant collagens would be preferable, but are difficult to produce. Recently, studies have shown that ‘collagens’ from bacteria, including Streptococcus pyogenes, can be produced in the laboratory as recombinant products, and that these are biocompatible. In the present study we have established that examples of bacterial collagens can be produced in a bioreactor with high yields providing proof of manufacture of this important group of proteins. Results Production trials in shake flask cultures gave low yields of recombinant product, < 1 g/L. Increased yields, of around 1 g/L, were obtained when the shake flask process was transferred to a stirred tank bioreactor, and the yield was further enhanced to around 10 g/L by implementation of a high cell density fed-batch process and the use of suitably formulated fully defined media. Similar yields were obtained with 2 different constructs, one containing an introduced heparin binding domain. The best yields, of up to 19 g/L were obtained using this high cell density strategy, with an extended 24 h production time. Conclusions These data have shown that recombinant bacterial collagen from S. pyogenes, can be produced in sufficient yield by a scalable microbial production process to give commercially acceptable yields for broad use in biomedical applications. PMID:23126526

  10. Structural characterization of the virulence factor Sda1 nuclease from Streptococcus pyogenes.

    PubMed

    Moon, Andrea F; Krahn, Juno M; Lu, Xun; Cuneo, Matthew J; Pedersen, Lars C

    2016-05-01

    Infection by Group A Streptococcus pyogenes (GAS) is a leading cause of severe invasive disease in humans, including streptococcal toxic shock syndrome and necrotizing fasciitis. GAS infections lead to nearly 163,000 annual deaths worldwide. Hypervirulent strains of S. pyogenes have evolved a plethora of virulence factors that aid in disease-by promoting bacterial adhesion to host cells, subsequent invasion of deeper tissues and blocking the immune system's attempts to eradicate the infection. Expression and secretion of the extracellular nuclease Sda1 is advantageous for promoting bacterial dissemination throughout the host organism, and evasion of the host's innate immune response. Here we present two crystal structures of Sda1, as well as biochemical studies to address key structural features and surface residues involved in DNA binding and catalysis. In the active site, Asn211 is observed to directly chelate a hydrated divalent metal ion and Arg124, on the putative substrate binding loop, likely stabilizes the transition state during phosphodiester bond cleavage. These structures provide a foundation for rational drug design of small molecule inhibitors to be used in prevention of invasive streptococcal disease. PMID:26969731

  11. Structural characterization of the virulence factor Sda1 nuclease from Streptococcus pyogenes

    PubMed Central

    Moon, Andrea F.; Krahn, Juno M.; Lu, Xun; Cuneo, Matthew J.; Pedersen, Lars C.

    2016-01-01

    Infection by Group A Streptococcus pyogenes (GAS) is a leading cause of severe invasive disease in humans, including streptococcal toxic shock syndrome and necrotizing fasciitis. GAS infections lead to nearly 163,000 annual deaths worldwide. Hypervirulent strains of S. pyogenes have evolved a plethora of virulence factors that aid in disease—by promoting bacterial adhesion to host cells, subsequent invasion of deeper tissues and blocking the immune system's attempts to eradicate the infection. Expression and secretion of the extracellular nuclease Sda1 is advantageous for promoting bacterial dissemination throughout the host organism, and evasion of the host's innate immune response. Here we present two crystal structures of Sda1, as well as biochemical studies to address key structural features and surface residues involved in DNA binding and catalysis. In the active site, Asn211 is observed to directly chelate a hydrated divalent metal ion and Arg124, on the putative substrate binding loop, likely stabilizes the transition state during phosphodiester bond cleavage. These structures provide a foundation for rational drug design of small molecule inhibitors to be used in prevention of invasive streptococcal disease. PMID:26969731

  12. An improved SELEX technique for selection of DNA aptamers binding to M-type 11 of Streptococcus pyogenes.

    PubMed

    Hamula, Camille L A; Peng, Hanyong; Wang, Zhixin; Tyrrell, Gregory J; Li, Xing-Fang; Le, X Chris

    2016-03-15

    Streptococcus pyogenes is a clinically important pathogen consisting of various serotypes determined by different M proteins expressed on the cell surface. The M type is therefore a useful marker to monitor the spread of invasive S. pyogenes in a population. Serotyping and nucleic acid amplification/sequencing methods for the identification of M types are laborious, inconsistent, and usually confined to reference laboratories. The primary objective of this work is to develop a technique that enables generation of aptamers binding to specific M-types of S. pyogenes. We describe here an in vitro technique that directly used live bacterial cells and the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) strategy. Live S. pyogenes cells were incubated with DNA libraries consisting of 40-nucleotides randomized sequences. Those sequences that bound to the cells were separated, amplified using polymerase chain reaction (PCR), purified using gel electrophoresis, and served as the input DNA pool for the next round of SELEX selection. A specially designed forward primer containing extended polyA20/5Sp9 facilitated gel electrophoresis purification of ssDNA after PCR amplification. A counter-selection step using non-target cells was introduced to improve selectivity. DNA libraries of different starting sequence diversity (10(16) and 10(14)) were compared. Aptamer pools from each round of selection were tested for their binding to the target and non-target cells using flow cytometry. Selected aptamer pools were then cloned and sequenced. Individual aptamer sequences were screened on the basis of their binding to the 10 M-types that were used as targets. Aptamer pools obtained from SELEX rounds 5-8 showed high affinity to the target S. pyogenes cells. Tests against non-target Streptococcus bovis, Streptococcus pneumoniae, and Enterococcus species demonstrated selectivity of these aptamers for binding to S. pyogenes. Several aptamer sequences were found to bind

  13. Functional and Structural Properties of a Novel Protein and Virulence Factor (Protein sHIP) in Streptococcus pyogenes *

    PubMed Central

    Wisniewska, Magdalena; Happonen, Lotta; Kahn, Fredrik; Varjosalo, Markku; Malmström, Lars; Rosenberger, George; Karlsson, Christofer; Cazzamali, Giuseppe; Pozdnyakova, Irina; Frick, Inga-Maria; Björck, Lars; Streicher, Werner; Malmström, Johan; Wikström, Mats

    2014-01-01

    Streptococcus pyogenes is a significant bacterial pathogen in the human population. The importance of virulence factors for the survival and colonization of S. pyogenes is well established, and many of these factors are exposed to the extracellular environment, enabling bacterial interactions with the host. In the present study, we quantitatively analyzed and compared S. pyogenes proteins in the growth medium of a strain that is virulent to mice with a non-virulent strain. Particularly, one of these proteins was present at significantly higher levels in stationary growth medium from the virulent strain. We determined the three-dimensional structure of the protein that showed a unique tetrameric organization composed of four helix-loop-helix motifs. Affinity pull-down mass spectrometry analysis in human plasma demonstrated that the protein interacts with histidine-rich glycoprotein (HRG), and the name sHIP (streptococcal histidine-rich glycoprotein-interacting protein) is therefore proposed. HRG has antibacterial activity, and when challenged by HRG, sHIP was found to rescue S. pyogenes bacteria. This and the finding that patients with invasive S. pyogenes infection respond with antibody production against sHIP suggest a role for the protein in S. pyogenes pathogenesis. PMID:24825900

  14. Counteractive balancing of transcriptome expression involving CodY and CovRS in Streptococcus pyogenes.

    PubMed

    Kreth, Jens; Chen, Zhiyun; Ferretti, Joseph; Malke, Horst

    2011-08-01

    Streptococcus pyogenes (group A streptococcus [GAS]) responds to environmental changes in a manner that results in an adaptive regulation of the transcriptome. The objective of the present study was to understand how two global transcriptional regulators, CodY and CovRS, coordinate the transcriptional network in S. pyogenes. Results from expression microarray data and quantitative reverse transcription-PCR (qRT-PCR) showed that the global regulator CodY controls the expression of about 250 genes, or about 17% of the genome of strain NZ131. Additionally, the codY gene was shown to be negatively autoregulated, with its protein binding directly to the promoter region with a CodY binding site. In further studies, the influence of codY, covRS, and codY-covRS mutations on gene expression was analyzed in growth phase-dependent conditions using C medium, reported to mimic nutritional abundance and famine conditions similar to those found during host GAS infection. Additional biological experiments of several virulence phenotypes, including pilin production, biofilm formation, and NAD glycohydrolase activity, demonstrated the role that both CodY and CovRS play in their regulation. Correlation analysis of the overall data revealed that, in exponentially growing cells, CodY and CovRS act in opposite directions, with CodY stimulating and CovRS repressing a substantial fraction of the core genome, including many virulence factors. This is the first report of counteractive balancing of transcriptome expression by global transcription regulators and provides important insight into how GAS modulates gene expression by integrating important extracellular and intracellular information. PMID:21705595

  15. Generation of Metabolically Diverse Strains of Streptococcus pyogenes during Survival in Stationary Phase▿

    PubMed Central

    Wood, Daniel N.; Weinstein, Kathryn E.; Podbielski, Andreas; Kreikemeyer, Berndt; Gaughan, John P.; Valentine, Samara; Buttaro, Bettina A.

    2009-01-01

    Streptococcus pyogenes, in addition to causing fulminant disease, can be carried asymptomatically and may survive in the host without causing disease. Long-term stationary-phase cultures were used to characterize the metabolism of cultures surviving after glucose depletion. Survival of stationary-phase cultures in glucose-depleted rich medium was truncated by switching the cells to phosphate-buffered saline or by the addition of antibiotics, suggesting that survival depended on the presence of nutrients and metabolic activity. The metabolites of the pyruvate-to-acetate (PA) pathway (acetate and formate) and amino acid catabolic pathways (ammonia) accumulated throughout long-term stationary phase (12 weeks). Acid and ammonia production was balanced so that the culture pH was maintained above pH 5.6. Strains isolated from long-term stationary-phase cultures accumulated mutations that resulted in unique exponential-phase metabolisms, with some strains expressing the PA pathway, some strains producing ammonia, and some strains expressing both in the presence of glucose. Strains expressing high levels of PA pathway activity during exponential growth were unable to survive when regrown in pure culture due to the production of excess acid. These data suggest that S. pyogenes diversifies during survival in stationary phase into distinct strains with different metabolisms and that complementary metabolism is required to control the pH in stationary-phase cultures. One of three survivor strains isolated from tonsillar discard material from patients expressed high levels of the PA pathway during exponential growth. Sequencing of multiple group A streptococcus regulators revealed two different mutations in two different strains, suggesting that random mutation occurs during survival. PMID:19666718

  16. Primary peritonitis by Streptococcus pyogenes. A condition as rare as it is aggressive.

    PubMed

    Abellán Morcillo, Israel; González, Antonio; Selva Cabañero, Pilar; Bernabé, Antonio

    2016-04-01

    We report the case of a 60-year-old female patient who presented to the emergency room for abdominal pain standing with impaired general status, fever of up to 38.7ºC, and somnolence. Upon arrival the patient had a heart rate of 115 bpm, hypotension (80/40 mmHg),acute respiratory distress, and both hepatic and renal failure. During her examination the patient was drowsy and had a diffusely tender abdomen with peritoneal irritation signs. Blood tests revealed 22,000 WBCs (82%N), CRP 32.4 mg/dL, total bilirubin 3.2 mg/dL, GOT 300 U/L, GPT 160 U/L, LDH 200 U/L, AP 310 U/L, 91,000 platelets, creatinine2.3 mg/dL, and PA 64%. An abdominal CT scan was performed, which revealed a minimal amount of free intraperitoneal fluid with no other findings. Given the patient's poor status an exploratory laparoscopy was carried out, which found a moderate amount of diffuse purulent exudate, particularly in interloop and lesser pelvis areas, with no additional findings. Following surgery she was transferred to the intensive care unit on wide spectrum antibiotics .Peritoneal exudate cultures from the surgical procedure revealed Streptococcus pyogenes. The patient had a favorable outcome being subsequently discharged from hospital at day 10 after the procedure. S. pyogenesis a beta hemolytic streptococcus well known as a cause of pharyngotonsillar, skin and soft tissues infection. Primary peritonitis by S.pyogenesis a rare condition with only a few isolated cases reported. PP cases by S.pyogenes predominantly involve previously healthy young women. PP diagnosis is usually retrospective, when other causes have been ruled out by surgery and culture is positive post hoc. An appropriate differential diagnosis from conditions such as gram-negative shock, staphylococcal toxic shock, meningococcal disease, viral infection, etc., is crucial. Abdominal CT may be helpful but a variable amount of free intraperitoneal fluid is usually the only finding. The surgical approach is usually laparoscopy

  17. The FbaB-type fibronectin-binding protein of Streptococcus pyogenes promotes specific invasion into endothelial cells

    PubMed Central

    Amelung, Silva; Nerlich, Andreas; Rohde, Manfred; Spellerberg, Barbara; Cole, Jason N.; Nizet, Victor; Chhatwal, Gursharan S.; Talay, Susanne R.

    2016-01-01

    Summary Invasive serotype M3 Streptococcus pyogenes are among the most frequently isolated organisms from patients suffering from invasive streptococcal disease and have the potential to invade primary human endothelial cells (EC) via a rapid and efficient mechanism. FbaB protein, the fibronectin-binding protein expressed by M3 S. pyogenes, was herein identified as a potent invasin for EC. By combining heterologous gene expression with allelic replacement, we demonstrate that FbaB is essential and sufficient to trigger EC invasion via a Rac1-dependent phagocytosis-like uptake. FbaB-mediated uptake follows the classical endocytic pathway with lysosomal destination. FbaB is demonstrated to be a streptococcal invasin exhibiting EC tropism. FbaB thus initiates a process that may contribute to the deep tissue tropism and spread of invasive S. pyogenes isolates into the vascular EC lining. PMID:21615663

  18. A systematic and functional classification of Streptococcus pyogenes that serves as a new tool for molecular typing and vaccine development.

    PubMed

    Sanderson-Smith, Martina; De Oliveira, David M P; Guglielmini, Julien; McMillan, David J; Vu, Therese; Holien, Jessica K; Henningham, Anna; Steer, Andrew C; Bessen, Debra E; Dale, James B; Curtis, Nigel; Beall, Bernard W; Walker, Mark J; Parker, Michael W; Carapetis, Jonathan R; Van Melderen, Laurence; Sriprakash, Kadaba S; Smeesters, Pierre R

    2014-10-15

    Streptococcus pyogenes ranks among the main causes of mortality from bacterial infections worldwide. Currently there is no vaccine to prevent diseases such as rheumatic heart disease and invasive streptococcal infection. The streptococcal M protein that is used as the substrate for epidemiological typing is both a virulence factor and a vaccine antigen. Over 220 variants of this protein have been described, making comparisons between proteins difficult, and hindering M protein-based vaccine development. A functional classification based on 48 emm-clusters containing closely related M proteins that share binding and structural properties is proposed. The need for a paradigm shift from type-specific immunity against S. pyogenes to emm-cluster based immunity for this bacterium should be further investigated. Implementation of this emm-cluster-based system as a standard typing scheme for S. pyogenes will facilitate the design of future studies of M protein function, streptococcal virulence, epidemiological surveillance, and vaccine development. PMID:24799598

  19. Molecular characterization of Streptococcus pyogenes group A isolates from a tertiary hospital in Lebanon.

    PubMed

    Karaky, Nathalie M; Araj, George F; Tokajian, Sima T

    2014-09-01

    Streptococcus pyogenes [Group A Streptococcus (GAS)] is one of the most important human pathogens, responsible for numerous diseases with diverse clinical manifestations. As the epidemiology of GAS infections evolves, a rapid and reliable characterization of the isolates remains essential for epidemiological analysis and infection control. This study investigated the epidemiological patterns and genetic characteristics of 150 GAS isolates from a tertiary hospital in Lebanon by emm typing, superantigens (SAgs) detection, PFGE and antibiotic profiling. The results revealed 41 distinct emm types, the most prevalent of which were emm89 (16 %), emm12 (10 %), emm2 (9 %) and emm1 (8 %). Testing for the presence of superantigens showed that speB (87 %), ssa (36 %) and speG (30 %) were predominant. PFGE detected 39 pulsotypes when a similarity cut-off value of 80 % was implemented. Antibiotic-susceptibility testing against seven different classes of antibiotics showed that 9 % of the isolates were resistant to clindamycin, 23 % were resistant to erythromycin and 4 % showed the macrolide-lincosamide-streptogramin B (MLSB) phenotype. The emergence of tetracycline-resistant strains (37 %) was high when compared with previous reports from Lebanon. This study provided comprehensive evidence of the epidemiology of GAS in Lebanon, highlighting the association between emm types and toxin genes, and providing valuable information about the origin and dissemination of this pathogen. PMID:24980572

  20. Essential Genes in the Core Genome of the Human Pathogen Streptococcus pyogenes

    PubMed Central

    Le Breton, Yoann; Belew, Ashton T.; Valdes, Kayla M.; Islam, Emrul; Curry, Patrick; Tettelin, Hervé; Shirtliff, Mark E.; El-Sayed, Najib M.; McIver, Kevin S.

    2015-01-01

    Streptococcus pyogenes (Group A Streptococcus, GAS) remains a major public health burden worldwide, infecting over 750 million people leading to over 500,000 deaths annually. GAS pathogenesis is complex, involving genetically distinct GAS strains and multiple infection sites. To overcome fastidious genetic manipulations and accelerate pathogenesis investigations in GAS, we developed a mariner-based system (Krmit) for en masse monitoring of complex mutant pools by transposon sequencing (Tn-seq). Highly saturated transposant libraries (Krmit insertions in ca. every 25 nucleotides) were generated in two distinct GAS clinical isolates, a serotype M1T1 invasive strain 5448 and a nephritogenic serotype M49 strain NZ131, and analyzed using a Bayesian statistical model to predict GAS essential genes, identifying sets of 227 and 241 of those genes in 5448 and NZ131, respectively. A large proportion of GAS essential genes corresponded to key cellular processes and metabolic pathways, and 177 were found conserved within the GAS core genome established from 20 available GAS genomes. Selected essential genes were validated using conditional-expression mutants. Finally, comparison to previous essentiality analyses in S. sanguinis and S. pneumoniae revealed significant overlaps, providing valuable insights for the development of new antimicrobials to treat infections by GAS and other pathogenic streptococci. PMID:25996237

  1. Spontaneous mutations in Streptococcus pyogenes isolates from streptococcal toxic shock syndrome patients play roles in virulence.

    PubMed

    Ikebe, Tadayoshi; Matsumura, Takayuki; Nihonmatsu, Hisako; Ohya, Hitomi; Okuno, Rumi; Mitsui, Chieko; Kawahara, Ryuji; Kameyama, Mitsuhiro; Sasaki, Mari; Shimada, Naomi; Ato, Manabu; Ohnishi, Makoto

    2016-01-01

    Streptococcus pyogenes (group A Streptococcus; GAS) is a widespread human pathogen and causes streptococcal toxic shock syndrome (STSS). STSS isolates have been previously shown to have high frequency mutations in the csrS/csrR (covS/covR) and/or rgg (ropB) genes, which are negative regulators of virulence. However, these mutations were found at somewhat low frequencies in emm1-genotyped isolates, the most prevalent STSS genotype. In this study, we sought to detect causal mutations of enhanced virulence in emm1 isolates lacking mutation(s) in the csrS/csrR and rgg genes. Three mutations associated with elevated virulence were found in the sic (a virulence gene) promoter, the csrR promoter, and the rocA gene (a csrR positive regulator). In vivo contribution of the sic promoter and rocA mutations to pathogenicity and lethality was confirmed in a GAS mouse model. Frequency of the sic promoter mutation was significantly higher in STSS emm1 isolates than in non-invasive STSS isolates; the rocA gene mutation frequency was not significantly different among STSS and non-STSS isolates. STSS emm1 isolates possessed a high frequency mutation in the sic promoter. Thus, this mutation may play a role in the dynamics of virulence and STSS pathogenesis. PMID:27349341

  2. Antibody to streptococcal cysteine proteinase as a seromarker of group A Streptococcal (Streptococcus pyogenes) infections.

    PubMed

    Batsford, Stephen; Brundiers, Mechtild; Schweier, Oliver; Horbach, Elmar; Mönting, Jürgen Schulte

    2002-01-01

    Serological tests are commonly employed to aid the diagnosis of Streptococcus pyogenes infections, particularly when non-suppurative sequelae are suspected. Conventional laboratory practice is to measure antibody levels to various combinations of the extracellular group A Streptococcus (GAS) antigens streptolysin O (SLO), DNase B, streptokinase and hyaluronidase. Antibody to the extracellular cysteine proteinase streptococcal pyrogenic exotoxin B (SPE B) and its precursor zymogen is also produced in response to GAS infections. An indirect hemagglutination test for antibody to zymogen/SPE B was established and evaluated in serum samples from 168 patients with proven (n = 27) or suspected GAS (n = 141) infections, which were also screened for antibodies using the 4 conventional tests. For comparison, sera from 56 patients infected with a variety of other pathogens, as well as sera from 16 patients infected with either S. agalactiae or S. pneumoniae and 34 sera from healthy subjects, were tested. Statistical analysis confirmed that antibody to zymogen/SPE B is a serological marker that can discriminate GAS infections. It can be ranked with the anti-SLO titer, currently the most widely used test, as a marker of an antecedent GAS infection. PMID:12160165

  3. Molecular and genomic characterization of pathogenic traits of group A Streptococcus pyogenes

    PubMed Central

    HAMADA, Shigeyuki; KAWABATA, Shigetada; NAKAGAWA, Ichiro

    2015-01-01

    Group A streptococcus (GAS) or Streptococcus pyogenes causes various diseases ranging from self-limiting sore throat to deadly invasive diseases. The genome size of GAS is 1.85–1.9 Mb, and genomic rearrangement has been demonstrated. GAS possesses various surface-associated substances such as hyaluronic capsule, M proteins, and fibronectin/laminin/immunoglobulin-binding proteins. These are related to the virulence and play multifaceted and mutually reflected roles in the pathogenesis of GAS infections. Invasion of GAS into epithelial cells and deeper tissues provokes immune and non-immune defense or inflammatory responses including the recruitment of neutrophils, macrophages, and dendritic cells in hosts. GAS frequently evades host defense mechanisms by using its virulence factors. Extracellular products of GAS may perturb cellular and subcellular functions and degrade tissues enzymatically, which leads to the aggravation of local and/or systemic disorders in the host. In this review, we summarize some important cellular and extracellular substances that may affect pathogenic processes during GAS infections, and the host responses to these. PMID:26666305

  4. Spontaneous mutations in Streptococcus pyogenes isolates from streptococcal toxic shock syndrome patients play roles in virulence

    PubMed Central

    Ikebe, Tadayoshi; Matsumura, Takayuki; Nihonmatsu, Hisako; Ohya, Hitomi; Okuno, Rumi; Mitsui, Chieko; Kawahara, Ryuji; Kameyama, Mitsuhiro; Sasaki, Mari; Shimada, Naomi; Ato, Manabu; Ohnishi, Makoto

    2016-01-01

    Streptococcus pyogenes (group A Streptococcus; GAS) is a widespread human pathogen and causes streptococcal toxic shock syndrome (STSS). STSS isolates have been previously shown to have high frequency mutations in the csrS/csrR (covS/covR) and/or rgg (ropB) genes, which are negative regulators of virulence. However, these mutations were found at somewhat low frequencies in emm1-genotyped isolates, the most prevalent STSS genotype. In this study, we sought to detect causal mutations of enhanced virulence in emm1 isolates lacking mutation(s) in the csrS/csrR and rgg genes. Three mutations associated with elevated virulence were found in the sic (a virulence gene) promoter, the csrR promoter, and the rocA gene (a csrR positive regulator). In vivo contribution of the sic promoter and rocA mutations to pathogenicity and lethality was confirmed in a GAS mouse model. Frequency of the sic promoter mutation was significantly higher in STSS emm1 isolates than in non-invasive STSS isolates; the rocA gene mutation frequency was not significantly different among STSS and non-STSS isolates. STSS emm1 isolates possessed a high frequency mutation in the sic promoter. Thus, this mutation may play a role in the dynamics of virulence and STSS pathogenesis. PMID:27349341

  5. Veno-arterial extracorporeal membrane oxygenation for Streptococcus pyogenes toxic shock syndrome in pregnancy.

    PubMed

    Imaeda, Taro; Nakada, Taka-Aki; Abe, Ryuzo; Tateishi, Yoshihisa; Oda, Shigeto

    2016-06-01

    Streptococcal toxic shock syndrome (STSS), an invasive Streptococcus pyogenes (Group A streptococcus) infection with hypotension and multiple organ failure, is quite rare in pregnancy but is characterized by rapid disease progression and high fatality rates. We present a case of STSS with infection-induced cardiac dysfunction in a pregnant woman who was treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). A 24-year-old multiparous woman in the third trimester had early symptoms of high fever and diarrhea 1 day prior to admission to the hospital emergency department. On admission, she had multiple organ failure including circulatory failure. Due to fetal distress, emergency Cesarean section was carried out and transferred to intensive care units. She had refractory circulatory failure with depressed myocardial contractility with progressive multiple organ failure, despite receiving significant hemodynamic supports including high-dose catecholamine. Thus, VA-ECMO was initiated 18 h after intensive care unit admission. Consequently, ECMO provided extra time to recover from infection and myocardial depression. She was successfully weaned from VA-ECMO on day 7 and was discharged home on day 53. VA-ECMO can be a therapeutic option for refractory circulatory failure with significant myocardial depression in STSS. PMID:26758056

  6. Zn2+ Uptake in Streptococcus pyogenes: Characterization of adcA and lmb Null Mutants

    PubMed Central

    Tedde, Vittorio; Rosini, Roberto; Galeotti, Cesira L.

    2016-01-01

    An effective regulation of metal ion homeostasis is essential for the growth of microorganisms in any environment and in pathogenic bacteria is strongly associated with their ability to invade and colonise their hosts. To gain a better insight into zinc acquisition in Group A Streptococcus (GAS) we characterized null deletion mutants of the adcA and lmb genes of Streptococcus pyogenes strain MGAS5005 encoding the orthologues of AdcA and AdcAII, the two surface lipoproteins with partly redundant roles in zinc homeostasis in Streptococcus pneumoniae. Null adcA and lmb mutants were analysed for their capability to grow in zinc-depleted conditions and were found to be more susceptible to zinc starvation, a phenotype that could be rescued by the addition of Zn2+ ions to the growth medium. Expression of AdcA, Lmb and HtpA, the polyhistidine triad protein encoded by the gene adjacent to lmb, during growth under conditions of limited zinc availability was examined by Western blot analysis in wild type and null mutant strains. In the wild type strain, AdcA was always present with little variation in expression levels between conditions of excess or limited zinc availability. In contrast, Lmb and HtpA were expressed at detectable levels only during growth in the presence of low zinc concentrations or in the null adcA mutant, when expression of lmb is required to compensate for the lack of adcA expression. In the latter case, Lmb and HtpA were overexpressed by several fold, thus indicating that also in GAS AdcA is a zinc-specific importer and, although it shares this function with Lmb, the two substrate-binding proteins do not show fully overlapping roles in zinc homeostasis. PMID:27031880

  7. Unraveling the regulatory network in Streptococcus pyogenes: the global response regulator CovR represses rivR directly.

    PubMed

    Roberts, Samantha A; Churchward, Gordon G; Scott, June R

    2007-02-01

    The response regulator CovR acts as a master regulator of virulence in Streptococcus pyogenes by repressing transcription of approximately 15% of the group A streptococcus genome directly or indirectly. We demonstrate that phosphorylated CovR represses transcription of rivR directly by binding to conserved sequences located downstream from the promoter to block procession of RNA polymerase. This establishes the first link in a regulatory network where CovR interacts directly with other proteins that modulate gene expression. PMID:16963575

  8. Growth-Phase-Dependent Expression of Virulence Factors in an M1T1 Clinical Isolate of Streptococcus pyogenes

    PubMed Central

    Unnikrishnan, Meera; Cohen, Jonathan; Sriskandan, Shiranee

    1999-01-01

    The effect of growth phase on expression of virulence-associated factors was studied by Northern hybridization in an M1T1 clinical isolate of Streptococcus pyogenes. Expression of M protein, C5a peptidase, and capsule was maximal in the exponential phase of growth, while streptococcal pyrogenic exotoxins A and B and mitogenic factor were maximally expressed in later phases of growth. PMID:10496938

  9. Growth-phase-dependent expression of virulence factors in an M1T1 clinical isolate of Streptococcus pyogenes.

    PubMed

    Unnikrishnan, M; Cohen, J; Sriskandan, S

    1999-10-01

    The effect of growth phase on expression of virulence-associated factors was studied by Northern hybridization in an M1T1 clinical isolate of Streptococcus pyogenes. Expression of M protein, C5a peptidase, and capsule was maximal in the exponential phase of growth, while streptococcal pyrogenic exotoxins A and B and mitogenic factor were maximally expressed in later phases of growth. PMID:10496938

  10. 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

  11. IL-2 Expression and T lymphocyte Phenotyping in Young Children Suffering from Upper Respiratory Tract Infection with Streptococcus Pyogenes

    PubMed Central

    Guadalupe Ramirez-Valles, Eda; Dayali Gutierrez-Martinez, Verónica; Cervantes-Flores, Maribel; Ruiz-Baca, Estela; Alvarado-Esquivel, Cosme

    2016-01-01

    T cells are components of adaptive immunity and are involved in the resolution of respiratory infections, which are a major cause of morbidity and mortality in young children worldwide. Activation and differentiation of T cells is given mostly by the cytokine IL-2. This study aimed to determine the phenotype of T cells and IL-2 expression in children suffering from upper respiratory tract infection with Streptococcus pyogenes (S. pyogenes). For this purpose, IL-2 expression at its gene and protein levels and quantitation of CD4+ and CD8+ T lymphocytes were assessed in children aged 0-5 years old suffering from upper respiratory tract infection with S. pyogenes and healthy children of the same age. Children with S. pyogenes infection had a higher expression of IL-2 gene and a lower level of this cytokine expression at protein level than healthy children. The numbers of CD4+ T lymphocytes were similar among the groups. In contrast, difference in the numbers of CD8+ T lymphocytes among the groups was found. We conclude that infections by S. pyogenes in young children lead to an increased expression of IL-2 mRNA. PMID:27493590

  12. Adherence of streptococcus pyogenes, Escherichia coli, and Pseudomonas aeruginosa to fibronectin-coated and uncoated epithelial cells.

    PubMed Central

    Abraham, S N; Beachey, E H; Simpson, W A

    1983-01-01

    The relationship between the variability in the fibronectin (Fn) content on human buccal epithelial cells and the capacity of the cells to bind gram-positive (Streptococcus pyogenes) or gram-negative (Escherichia coli or Pseudomonas aeruginosa) bacteria was investigated. Adhesion experiments performed with mixtures of epithelial cells and mixed suspensions of either S. pyogenes and E. coli or S. pyogenes and P. aeruginosa exhibited three major populations of buccal cells: one of these was able to bind S. pyogenes (gram positive) but neither of the gram-negative bacteria; a second population was able to bind the gram-negative but not the gram-positive bacteria; and a third was able to bind various numbers of both types of organisms. Further adhesion experiments performed with a mixture of epithelial cells and a mixed suspension of S. pyrogens, E. coli, and fluoresceinconjugated methacrylate beads coated with immune immunoglobulin G directed against Fn revealed that the epithelial cells recognizing the gram-positive bacteria were rich in Fn, whereas those recognizing the gram-negative organisms were poor in Fn. Immunoelectron microscopy confirmed that cells of S. pyogenes bound to epithelial cells coated with Fn, whereas cells of E. coli bound to epithelial cells lacking Fn. These results suggest that Fn on the surfaces of epithelial cells may modulate the ecology of the human oropharyngeal cavity, especially with respect to the colonization of these surfaces by pathogenic gram-negative or gram-positive bacteria. Images PMID:6411621

  13. Partial loss of CovS function in Streptococcus pyogenes causes severe invasive disease

    PubMed Central

    2013-01-01

    Background CovRS (or CsrRS) is a two-component regulatory system that regulates the production of multiple virulence factors in Streptococcus pyogenes. covS mutations are often found in isolates recovered from mice that have been experimentally infected with S. pyogenes and covS mutations enhance bacterial virulence in an invasive infection mouse model. In addition, covS mutations were detected more frequently in a panel of clinical isolates from severe invasive streptococcal infections than those from non-severe infections. Thus, covS mutations may be associated with the onset of severe invasive infections. Results Known covS mutations were divided into two groups: (i) frameshift mutations that caused a deletion of functional regions and (ii) point mutations that caused single (or double) amino acid(s) substitutions. Frameshift mutations are frequent in mouse-passaged isolates, whereas point mutations are frequent in clinical isolates. The functions of CovS proteins with a single amino acid substitution in clinical isolates were estimated based on the streptococcal pyrogenic exotoxin B (SpeB) production and NAD+-glycohydrolase (NADase) activity, which are known to be regulated by the CovRS system. Point mutations partially, but not completely, impaired the function of the covS alleles. We also investigated some of the benefits that a partial loss of function in covS alleles with point mutations might confer on clinical isolates. We found that covS knockout mutants (ΔcovS strains) had an impaired growth ability in a normal atmosphere in Todd Hewitt broth compared with parental isolates having wild-type or point-mutated covS. Conclusions The loss of CovS proteins in S. pyogenes may confer greater virulence, but bacteria may also lose the ability to respond to certain external signals recognized by CovS. Therefore, point mutations that retain the function of CovS and confer hypervirulence may have natural selective advantages. PMID:23537349

  14. Biochemical and biological activity of arginine deiminase from Streptococcus pyogenes M22.

    PubMed

    Starikova, Eleonora A; Sokolov, Alexey V; Vlasenko, Anna Yu; Burova, Larisa A; Freidlin, Irina S; Vasilyev, Vadim B

    2016-04-01

    Streptococcus pyogenes (group A Streptococcus; GAS) is an important gram-positive extracellular bacterial pathogen responsible for a number of suppurative infections. This micro-organism has developed complex virulence mechanisms to avoid the host's defenses. We have previously reported that SDSC from GAS type M22 causes endothelial-cell dysfunction, and inhibits cell adhesion, migration, metabolism, and proliferation in a dose-dependent manner, without affecting cell viability. This work aimed to isolate and characterize a component from GAS type M22 supernatant that suppresses the proliferation of endothelial cells (EA.hy926). In the process of isolating a protein possessing antiproliferative activity we identified arginine deiminase (AD). Further study showed that this enzyme is most active at pH 6.8. Calculating Km and Vmax gave the values of 0.67 mmol·L(-1) and 42 s(-1), respectively. A distinctive feature of AD purified from GAS type M22 is that its optimum activity and the maximal rate of the catalytic process is close to neutral pH by comparison with enzymes from other micro-organisms. AD from GAS type M22 suppressed the proliferative activity of endothelial cells in a dose-dependent mode. At the same time, in the presence of AD, the proportion of cells in G0/G1 phase increased. When l-Arg was added at increasing concentrations to the culture medium containing AD (3 μg·mL(-1)), the enzyme's capacity to inhibit cell proliferation became partially depressed. The proportion of cells in phases S/G2 increased concomitantly, although the cells did not fully recover their proliferation activity. This suggests that AD from GAS type M22 has potential for the suppression of excessive cell proliferation. PMID:26695833

  15. Control of Streptococcus pyogenes virulence: modeling of the CovR/S signal transduction system.

    PubMed

    Mitrophanov, Alexander Y; Churchward, Gordon; Borodovsky, Mark

    2007-05-01

    The CovR/S system in Streptococcus pyogenes (Group A Streptococcus, or GAS), a two-component signal transduction/transcription regulation system, controls the expression of major virulence factors. The presence of a negative feedback loop distinguishes the CovR/S system from the majority of bacterial two-component systems. We developed a deterministic model of the CovR/S system consisting of eight delay differential equations. Computational experiments showed that the system possessed a unique stable steady state. The dynamical behavior of the system showed a tendency for oscillations becoming more pronounced for longer but still biochemically realistic delays resulting from reductions in the rates of translation elongation. We have devised an efficient procedure for computing the system's steady state. Further, we have shown that the signal-response curves are hyperbolic for the default parameter values. However, in experiments with randomized parameters we demonstrated that sigmoidality of signal-response curves, implying a response threshold, is not only possible, but seems to be rather typical for CovR/S-like systems even when binding of the CovR response regulator protein to a promoter is non-cooperative. We used sensitivity analysis to simplify the model in order to make it analytically tractable. The existence and uniqueness of the steady state and hyperbolicity of signal-response curves for the majority of the variables was proved for the simplified model. Also, we found that provided CovS was active, the system was insensitive to changes in the concentration of any other phosphoryl donor such as acetyl phosphate. PMID:17240398

  16. Leukotriene B4 enhances innate immune defense against the puerperal sepsis agent Streptococcus pyogenes.

    PubMed

    Soares, Elyara M; Mason, Katie L; Rogers, Lisa M; Serezani, Carlos H; Faccioli, Lucia H; Aronoff, David M

    2013-02-15

    Puerperal sepsis is a leading cause of maternal mortality worldwide. Streptococcus pyogenes [group A Streptococcus; (GAS)] is a major etiologic agent of severe postpartum sepsis, yet little is known regarding the pathogenesis of these infections. Tissue macrophages provide innate defense against GAS, and their actions are highly regulated. The intracellular second messenger cAMP can negatively regulate macrophage actions against GAS. Because leukotriene (LT) B(4) has been shown to suppress intracellular cAMP in macrophages, we hypothesized that it could enhance innate defenses against GAS. We assessed the capacity of LTB(4) to modulate antistreptococcal actions of human macrophages, including placental and decidual macrophages and used a novel intrauterine infection model of GAS in mice lacking the 5-lipoxygenase enzyme to determine the role of endogenous LTs in host defense against this pathogen. Animals lacking 5-lipoxygenase were significantly more vulnerable to intrauterine GAS infection than were wild-type mice and showed enhanced dissemination of bacteria out of the uterus and a more robust inflammatory response than did wild-type mice. In addition, LTB(4) reduced intracellular cAMP levels via the BLT1 receptor and was a potent stimulant of macrophage phagocytosis and NADPH oxidase-dependent intracellular killing of GAS. Importantly, interference was observed between the macrophage immunomodulatory actions of LTB(4) and the cAMP-inducing lipid PGE(2), suggesting that interplay between pro- and anti-inflammatory compounds may be important in vivo. This work underscores the potential for pharmacological targeting of lipid mediator signaling cascades in the treatment of invasive GAS infections. PMID:23325886

  17. Involvement of T6 Pili in Biofilm Formation by Serotype M6 Streptococcus pyogenes

    PubMed Central

    Kimura, Keiji Richard; Nakata, Masanobu; Sumitomo, Tomoko; Kreikemeyer, Bernd; Podbielski, Andreas; Terao, Yutaka

    2012-01-01

    The group A streptococcus (GAS) Streptococcus pyogenes is known to cause self-limiting purulent infections in humans. The role of GAS pili in host cell adhesion and biofilm formation is likely fundamental in early colonization. Pilus genes are found in the FCT (fibronectin-binding protein, collagen-binding protein, and trypsin-resistant antigen) genomic region, which has been classified into nine subtypes based on the diversity of gene content and nucleotide sequence. Several epidemiological studies have indicated that FCT type 1 strains, including serotype M6, produce large amounts of monospecies biofilm in vitro. We examined the direct involvement of pili in biofilm formation by serotype M6 clinical isolates. In the majority of tested strains, deletion of the tee6 gene encoding pilus shaft protein T6 compromised the ability to form biofilm on an abiotic surface. Deletion of the fctX and srtB genes, which encode pilus ancillary protein and class C pilus-associated sortase, respectively, also decreased biofilm formation by a representative strain. Unexpectedly, these mutant strains showed increased bacterial aggregation compared with that of the wild-type strain. When the entire FCT type 1 pilus region was ectopically expressed in serotype M1 strain SF370, biofilm formation was promoted and autoaggregation was inhibited. These findings indicate that assembled FCT type 1 pili contribute to biofilm formation and also function as attenuators of bacterial aggregation. Taken together, our results show the potential role of FCT type 1 pili in the pathogenesis of GAS infections. PMID:22155780

  18. Inducer expulsion in Streptococcus pyogenes: properties and mechanism of the efflux reaction

    SciTech Connect

    Sutrina, S.L.; Reizer, J.; Saier, M.H Jr.

    1988-04-01

    Expulsion of preaccumulated methyl-..beta..-D-thiogalactoside-phosphate (TMG-P) from Streptococcus pyogenes is a two-step process comprising intracellular dephosphorylation of TMG-P followed by rapid efflux of the intracellularly formed free galactoside. The present study identifies the mechanism and the order and characterizes the temperature dependency of the efflux step. Unidirectional efflux of the intracellularly formed (/sup 14/C)TMG was only slightly affected when measured in the presence of unlabeled TMG (25 to 400 mM) in the extracellular medium. In contrast, pronounced inhibition of net efflux was observed in the presence of relatively low concentrations (1 to 16 mM) of extracellular (/sup 14/C)TMG. Since net efflux was nearly arrested when the external concentration of (/sup 14/C)TMG approached the intracellular concentration of this sugar, we propose that a facilitated diffusion mechanism is responsible for efflux and equilibration of TMG between the intracellular and extracellular milieus. The exit reaction was markedly dependent upon temperature, exhibited a high energy of activation (23 kcal (ca. 96 kJ) per mol), and followed first-order kinetics, indicating that the permease mediating this efflux was not saturated under the conditions of expulsion employed.

  19. The Human Pathogen Streptococcus pyogenes Releases Lipoproteins as Lipoprotein-rich Membrane Vesicles*

    PubMed Central

    Biagini, Massimiliano; Garibaldi, Manuela; Aprea, Susanna; Pezzicoli, Alfredo; Doro, Francesco; Becherelli, Marco; Taddei, Anna Rita; Tani, Chiara; Tavarini, Simona; Mora, Marirosa; Teti, Giuseppe; D'Oro, Ugo; Nuti, Sandra; Soriani, Marco; Margarit, Immaculada; Rappuoli, Rino; Grandi, Guido; Norais, Nathalie

    2015-01-01

    Bacterial lipoproteins are attractive vaccine candidates because they represent a major class of cell surface-exposed proteins in many bacteria and are considered as potential pathogen-associated molecular patterns sensed by Toll-like receptors with built-in adjuvanticity. Although Gram-negative lipoproteins have been extensively characterized, little is known about Gram-positive lipoproteins. We isolated from Streptococcus pyogenes a large amount of lipoproteins organized in vesicles. These vesicles were obtained by weakening the bacterial cell wall with a sublethal concentration of penicillin. Lipid and proteomic analysis of the vesicles revealed that they were enriched in phosphatidylglycerol and almost exclusively composed of lipoproteins. In association with lipoproteins, a few hypothetical proteins, penicillin-binding proteins, and several members of the ExPortal, a membrane microdomain responsible for the maturation of secreted proteins, were identified. The typical lipidic moiety was apparently not necessary for lipoprotein insertion in the vesicle bilayer because they were also recovered from the isogenic diacylglyceryl transferase deletion mutant. The vesicles were not able to activate specific Toll-like receptor 2, indicating that lipoproteins organized in these vesicular structures do not act as pathogen-associated molecular patterns. In light of these findings, we propose to name these new structures Lipoprotein-rich Membrane Vesicles. PMID:26018414

  20. Preparation and characterization of monomers to tetramers of a collagen-like domain from Streptococcus pyogenes

    PubMed Central

    Peng, Yong Y; Stoichevska, Violet; Howell, Linda; Madsen, Soren; Werkmeister, Jerome A; Dumsday, Geoff J; Ramshaw, John AM

    2014-01-01

    The collagen like domain Scl2 from Streptococcus pyogenes has been proposed as a potential biomedical material. It is non-cytotoxic and non-immunogenic and can be prepared in good yield in fermentation. The Scl2 collagen domain is about a quarter of the length, 234 residues, of the main collagen type, mammalian type I collagen (1014 residues) that is currently used in biomedical devices. In the present study we have made constructs comprising 1 to 4 copies of the Scl2 collagen domain, plus these same constructs with a CysCys sequence at the C-terminal, analogous to that found in mammalian type III collagens. The yields of these constructs were examined from 2 L fermentation studies. The yields of both series declined with increasing size. Circular dichroism showed that the addition of further collagen domains did not lead to a change in the melting temperature compared to the monomer domain. Addition of the CysCys sequence led to a small additional stabilization of about 2-3°C for the monomer construct when the folding (V) domain was present. PMID:25482084

  1. Patterns of virulence gene expression differ between biofilm and tissue communities of Streptococcus pyogenes.

    PubMed

    Cho, Kyu Hong; Caparon, Michael G

    2005-09-01

    The ability of Streptococcus pyogenes to form biofilm-like bacterial communities during infection of soft tissue has suggested that the capacity to produce biofilm may be important for pathogenesis. To examine this relationship, a panel of mutants was evaluated for their ability to form biofilm on abiotic surfaces in several assays. Several established virulence factors were crucial for biofilm formation, including the M protein, required for initial cell-surface interactions, and the hyaluronic acid capsule, required for subsequent maturation into a three-dimensional structure. Mutants lacking the transcription regulators Mga and CovR (CsrR) also failed to form biofilm. Comparison of transcriptional profiles revealed differential regulation of approximately 25% of the genome upon adaptation to biofilm. During infection of zebrafish, several virulence factors (notably cysteine protease and streptokinase) were regulated in a biofilm-like manner. However, the overall profile of virulence factor expression indicated that tissue communities have a pattern of gene expression different from biofilm. Taken together, these data show that while biofilm and tissue communities have many characteristics in common, that biofilm reproduces only a subset of the myriad cues used by tissue communities for regulation of virulence. PMID:16135223

  2. An Association Between Peptidoglycan Synthesis and Organization of the Streptococcus pyogenes ExPortal

    PubMed Central

    Vega, Luis Alberto; Port, Gary C.; Caparon, Michael G.

    2013-01-01

    ABSTRACT The ExPortal of Streptococcus pyogenes is a focal microdomain of the cytoplasmic membrane that clusters the translocons of the general secretory pathway with accessory factors to facilitate the maturation of secreted polypeptides. While it is known that the ExPortal is enriched in anionic lipids, the mechanisms that organize the ExPortal are poorly understood. In the present study, we examined the role of the cell wall in organizing and maintaining the ExPortal. Removal of the cell wall resulted in a loss of ExPortal focal integrity accompanied by the circumferential redistribution of ExPortal lipid and protein components. A similar loss occurred upon treatment with gallidermin, a nonpermeabilizing lantibiotic that targets the lipid II precursor of peptidoglycan synthesis, and this treatment disrupted the secretion of several ExPortal substrates. Furthermore, several enzymes involved in the membrane-associated steps of lipid II synthesis, including MraY and MurN, were found to localize to a single discrete focus in the membrane that was coincident with the focal location of the secretory translocons and the anionic lipid microdomain. These data suggest that the ExPortal is associated with the site of peptidoglycan precursor synthesis and that peptidoglycan biogenesis influences ExPortal organization. These data add to an emerging literature indicating that cell wall biogenesis, cell division, and protein secretion are spatially coorganized processes. PMID:24065630

  3. Transcriptome Remodeling Contributes to Epidemic Disease Caused by the Human Pathogen Streptococcus pyogenes

    PubMed Central

    Beres, Stephen B.; Kachroo, Priyanka; Nasser, Waleed; Olsen, Randall J.; Zhu, Luchang; Flores, Anthony R.; de la Riva, Ivan; Paez-Mayorga, Jesus; Jimenez, Francisco E.; Cantu, Concepcion; Vuopio, Jaana; Jalava, Jari; Kristinsson, Karl G.; Gottfredsson, Magnus; Corander, Jukka; Fittipaldi, Nahuel; Di Luca, Maria Chiara; Petrelli, Dezemona; Vitali, Luca A.; Raiford, Annessa; Jenkins, Leslie

    2016-01-01

    ABSTRACT For over a century, a fundamental objective in infection biology research has been to understand the molecular processes contributing to the origin and perpetuation of epidemics. Divergent hypotheses have emerged concerning the extent to which environmental events or pathogen evolution dominates in these processes. Remarkably few studies bear on this important issue. Based on population pathogenomic analysis of 1,200 Streptococcus pyogenes type emm89 infection isolates, we report that a series of horizontal gene transfer events produced a new pathogenic genotype with increased ability to cause infection, leading to an epidemic wave of disease on at least two continents. In the aggregate, these and other genetic changes substantially remodeled the transcriptomes of the evolved progeny, causing extensive differential expression of virulence genes and altered pathogen-host interaction, including enhanced immune evasion. Our findings delineate the precise molecular genetic changes that occurred and enhance our understanding of the evolutionary processes that contribute to the emergence and persistence of epidemically successful pathogen clones. The data have significant implications for understanding bacterial epidemics and for translational research efforts to blunt their detrimental effects. PMID:27247229

  4. Preparation and characterization of monomers to tetramers of a collagen-like domain from Streptococcus pyogenes.

    PubMed

    Peng, Yong Y; Stoichevska, Violet; Howell, Linda; Madsen, Soren; Werkmeister, Jerome A; Dumsday, Geoff J; Ramshaw, John A M

    2014-01-01

    The collagen like domain Scl2 from Streptococcus pyogenes has been proposed as a potential biomedical material. It is non-cytotoxic and non-immunogenic and can be prepared in good yield in fermentation. The Scl2 collagen domain is about a quarter of the length, 234 residues, of the main collagen type, mammalian type I collagen (1014 residues) that is currently used in biomedical devices. In the present study we have made constructs comprising 1 to 4 copies of the Scl2 collagen domain, plus these same constructs with a CysCys sequence at the C-terminal, analogous to that found in mammalian type III collagens. The yields of these constructs were examined from 2 L fermentation studies. The yields of both series declined with increasing size. Circular dichroism showed that the addition of further collagen domains did not lead to a change in the melting temperature compared to the monomer domain. Addition of the CysCys sequence led to a small additional stabilization of about 2-3°C for the monomer construct when the folding (V) domain was present. PMID:25482084

  5. A new genotyping scheme based on MLVA for inter-laboratory surveillance of Streptococcus pyogenes.

    PubMed

    Imperi, Monica; Pittiglio, Valentina; D'Avenio, Giuseppe; Gherardi, Giovanni; Ciammaruconi, Andrea; Lista, Florigio; Pourcel, Christine; Baldassarri, Lucilla; Creti, Roberta

    2016-08-01

    A newly developed MLVA seven-loci scheme for Streptococcus pyogenes is described. The method can be successfully applied by using both agarose gel with visual inspections of bands and Lab on Chip technology. The potential of the present MLVA has been tested on a collection of 100 clinical GAS strains representing the most common emm types found in high-income countries plus 18 published gap-free genomes, in comparison to PFGE and MLST. The MLVA analysis defined 30 MLVA types with ten out of the considered 15 emm types exhibiting multiple and specific MLVA types. In only one occasion the same MLVA profile was shared between isolates belonging to two different emm types. A robust congruency between the methods was observed, with MLVA discriminating within clonal complexes as defined by PFGE or MLST. This new MLVA scheme can be adopted as a quick, low-cost and reliable typing method to track the short-term diffusion of GAS clones in inter-laboratory-based surveillance. PMID:27302039

  6. Targeted Quantitative Analysis of Streptococcus pyogenes Virulence Factors by Multiple Reaction Monitoring*S⃞

    PubMed Central

    Lange, Vinzenz; Malmström, Johan A.; Didion, John; King, Nichole L.; Johansson, Björn P.; Schäfer, Juliane; Rameseder, Jonathan; Wong, Chee-Hong; Deutsch, Eric W.; Brusniak, Mi-Youn; Bühlmann, Peter; Björck, Lars; Domon, Bruno; Aebersold, Ruedi

    2008-01-01

    In many studies, particularly in the field of systems biology, it is essential that identical protein sets are precisely quantified in multiple samples such as those representing differentially perturbed cell states. The high degree of reproducibility required for such experiments has not been achieved by classical mass spectrometry-based proteomics methods. In this study we describe the implementation of a targeted quantitative approach by which predetermined protein sets are first identified and subsequently quantified at high sensitivity reliably in multiple samples. This approach consists of three steps. First, the proteome is extensively mapped out by multidimensional fractionation and tandem mass spectrometry, and the data generated are assembled in the PeptideAtlas database. Second, based on this proteome map, peptides uniquely identifying the proteins of interest, proteotypic peptides, are selected, and multiple reaction monitoring (MRM) transitions are established and validated by MS2 spectrum acquisition. This process of peptide selection, transition selection, and validation is supported by a suite of software tools, TIQAM (Targeted Identification for Quantitative Analysis by MRM), described in this study. Third, the selected target protein set is quantified in multiple samples by MRM. Applying this approach we were able to reliably quantify low abundance virulence factors from cultures of the human pathogen Streptococcus pyogenes exposed to increasing amounts of plasma. The resulting quantitative protein patterns enabled us to clearly define the subset of virulence proteins that is regulated upon plasma exposure. PMID:18408245

  7. Extensive genetic diversity among clinical isolates of Streptococcus pyogenes serotype M5.

    PubMed

    Desai, M; Tanna, A; Efstratiou, A; George, R; Clewley, J; Stanley, J

    1998-03-01

    The genetic diversity of clinical isolates of Streptococcus pyogenes serotype M5 has been characterized. Strain genotypes were defined by macrorestriction profile, 16S ribotype, emm gene subtype, insertion element IS1239 profile, and exotoxin gene determinant. By these criteria, clinical isolates of M5 constituted a multiplicity of strain clusters rather than a homogeneous population as found for certain serotypes. Distance matrices and an unrooted tree were constructed from macrorestriction data with three rarely cutting endonucleases, determined by PFGE. A single IS1239 profile was common to 85% of isolates but there was great diversity of both ribotype and macrorestriction profile, and 18 different emm gene subtypes were detected by PCR-RFLP. DNA sequence analysis of the antigen-coding 5' (hypervariable) region of emm gene amplicons (about 240 bp) showed that 14/18 exhibited up to 6% divergence. Four amplicons had highly divergent sequences--corresponding to those previously determined for emm6, emm11, emm18 and emm77. Further serological and hybridization studies were used to analyse the discrepancy between the Lancefield serotype of these strains (M5) and their emm genotype. Overall, this study shows a high degree of genetic diversity in serotype M5, with implications for the Lancefield scheme itself, for the epidemiology of group A streptococci, and for recombinant DNA strategies for M protein-based vaccine development. PMID:9534234

  8. Variation in M protein production among Streptococcus pyogenes strains according to emm genotype.

    PubMed

    Matsumoto, Masakado; Suzuki, Masahiro; Hirose, Kaoru; Hiramatsu, Reiji; Minagawa, Hiroko; Minami, Masaaki; Tatsuno, Ichiro; Okamoto, Akira; Ohta, Michio; Hasegawa, Tadao

    2011-06-01

    M protein is an important virulence determinant in Streptococcus pyogenes, but the amounts of M protein in various strains of the species remain to be elucidated. To assess the amount of M protein in strains of each emm genotype, dot blot analysis was performed on 141 clinically isolated strains. Among the cell membrane-associated proteins, M protein was present in greater quantities in the emm1, 3, and 6 strains than in the other emm strains. In addition three strains, one each of the emm1, 3, and 6 types, showed prolific M protein production (M protein-high producers). These three emm genotypes are frequently isolated in clinical practice. Sequencing of the csrRS gene, one of the two-component signal transduction systems implicated in virulence, was performed on 25 strains bearing different amounts of M protein. CsrS mutations, in contrast to CsrR protein, were detected in 11 strains. The M protein-high producer strain of emm1 type carried two amino acid substitutions, whereas the other three emm1 strains carried only one substitution each. The M protein-high producer expressed its emm gene more strongly than the corresponding M protein-low producer did according to TaqMan RT-PCR. These observations suggest that the accumulation of amino acid substitutions in CsrS protein may contribute, at least in part, to the large amount of M protein production seen in several emm genotypes. PMID:21371090

  9. The characterization of two new low molecular weight proteins (LMPs) from Streptococcus pyogenes.

    PubMed

    Gerlach, D; Alouf, H; Morávek, L; Pavlik, M; Köhler, W

    1992-06-01

    Two novel extracellular mitogenic substances were isolated from Streptococcus pyogenes strain NY-5 and characterized. The purification steps involved an initial enrichment of the proteins from culture supernatant by silica gel adsorption, followed by ion exchange chromatography and gel filtration. The purified materials were homogeneous in SDS-PAGE, showed estimated molecular weights of 12 kD and isoelectric points of 4.7 and 4.3, respectively. Both proteins (LMP-12k-4.3pI and LMP-12k-4.7pI) demonstrated lymphocyte transformation activity at a concentration of 0.1 microgram/ml. The LMP-12k-4.7pI showed a 69.2% homology of the amino acid sequence with that of a phosphocarrier protein of Staphylococcus aureus and with a total identity in the active centre. The same protein was also isolated from streptococcal group C strain H46A with an N-terminal amino acid sequence being identical. The LMP-12k-4.7pI demonstrated biochemical properties identical with those of the earlier described streptococcal pyrogenic exotoxin type D. The LMP-12k-4.3pI did not show such a clear relation to other functional proteins. PMID:1520957

  10. Structural Studies of Streptococcus pyogenes Streptolysin O Provide Insights into the Early Steps of Membrane Penetration

    PubMed Central

    Feil, Susanne C.; Ascher, David B.; Kuiper, Michael J.; Tweten, Rodney K.; Parker, Michael W.

    2015-01-01

    Cholesterol-dependent cytolysins (CDCs) are a large family of bacterial toxins that exhibit a dependence on the presence of membrane cholesterol in forming large pores in cell membranes. Significant changes in the three-dimensional structure of these toxins are necessary to convert the soluble monomeric protein into a membrane pore. We have determined the crystal structure of the archetypical member of the CDC family, streptolysin O (SLO), a virulence factor from Streptococcus pyogenes. The overall fold is similar to previously reported CDC structures, although the C-terminal domain is in a different orientation with respect to the rest of the molecule. Surprisingly, a signature stretch of CDC sequence called the undecapeptide motif, a key region involved in membrane recognition, adopts a very different structure in SLO to that of the well-characterized CDC perfringolysin O (PFO), although the sequences in this region are identical. An analysis reveals that, in PFO, there are complementary interactions between the motif and the rest of domain 4 that are lost in SLO. Molecular dynamics simulations suggest that the loss of a salt bridge in SLO and a cation–pi interaction are determining factors in the extended conformation of the motif, which in turn appears to result in a greater flexibility of the neighboring L1 loop that houses a cholesterol-sensing motif. These differences may explain the differing abilities of SLO and PFO to efficiently penetrate target cell membranes in the first step of toxin insertion into the membrane. PMID:24316049

  11. Relevance of the two-component sensor protein CiaH to acid and oxidative stress responses in Streptococcus pyogenes

    PubMed Central

    2014-01-01

    Background The production of virulence proteins depends on environmental factors, and two-component regulatory systems are involved in sensing these factors. We previously established knockout strains in all suspected two-component regulatory sensor proteins of the emm1 clinical strain of S. pyogenes and examined their relevance to acid stimuli in a natural atmosphere. In the present study, their relevance to acid stimuli was re-examined in an atmosphere containing 5% CO2. Results The spy1236 (which is identical to ciaHpy) sensor knockout strain showed significant growth reduction compared with the parental strain in broth at pH 6.0, suggesting that the Spy1236 (CiaHpy) two-component sensor protein is involved in acid response of S. pyogenes. CiaH is also conserved in Streptococcus pneumoniae, and it has been reported that deletion of the gene for its cognate response regulator (ciaRpn) made the pneumococcal strains more sensitive to oxidative stress. In this report, we show that the spy1236 knockout mutant of S. pyogenes is more sensitive to oxidative stress than the parental strain. Conclusions These results suggest that the two-component sensor protein CiaH is involved in stress responses in S. pyogenes. PMID:24673808

  12. Molecular modeling and simulation of FabG, an enzyme involved in the fatty acid pathway of Streptococcus pyogenes.

    PubMed

    Shafreen, Rajamohmed Beema; Pandian, Shunmugiah Karutha

    2013-09-01

    Streptococcus pyogenes (SP) is the major cause of pharyngitis accompanied by strep throat infections in humans. 3-keto acyl reductase (FabG), an important enzyme involved in the elongation cycle of the fatty acid pathway of S. pyogenes, is essential for synthesis of the cell-membrane, virulence factors and quorum sensing-related mechanisms. Targeting SPFabG may provide an important aid for the development of drugs against S. pyogenes. However, the absence of a crystal structure for FabG of S. pyogenes limits the development of structure-based drug designs. Hence, in the present study, a homology model of FabG was generated using the X-ray crystallographic structure of Aquifex aeolicus (PDB ID: 2PNF). The modeled structure was refined using energy minimization. Furthermore, active sites were predicted, and a large dataset of compounds was screened against SPFabG. The ligands were docked using the LigandFit module that is available from Discovery Studio version 2.5. From this list, 13 best hit ligands were chosen based on the docking score and binding energy. All of the 13 ligands were screened for Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) properties. From this, the two best descriptors, along with one descriptor that lay outside the ADMET plot, were selected for molecular dynamic (MD) simulation. In vitro testing of the ligands using biological assays further substantiated the efficacy of the ligands that were screened based on the in silico methods. PMID:23988477

  13. Genome-scale reconstruction of the Streptococcus pyogenes M49 metabolic network reveals growth requirements and indicates potential drug targets.

    PubMed

    Levering, Jennifer; Fiedler, Tomas; Sieg, Antje; van Grinsven, Koen W A; Hering, Silvio; Veith, Nadine; Olivier, Brett G; Klett, Lara; Hugenholtz, Jeroen; Teusink, Bas; Kreikemeyer, Bernd; Kummer, Ursula

    2016-08-20

    Genome-scale metabolic models comprise stoichiometric relations between metabolites, as well as associations between genes and metabolic reactions and facilitate the analysis of metabolism. We computationally reconstructed the metabolic network of the lactic acid bacterium Streptococcus pyogenes M49. Initially, we based the reconstruction on genome annotations and already existing and curated metabolic networks of Bacillus subtilis, Escherichia coli, Lactobacillus plantarum and Lactococcus lactis. This initial draft was manually curated with the final reconstruction accounting for 480 genes associated with 576 reactions and 558 metabolites. In order to constrain the model further, we performed growth experiments of wild type and arcA deletion strains of S. pyogenes M49 in a chemically defined medium and calculated nutrient uptake and production fluxes. We additionally performed amino acid auxotrophy experiments to test the consistency of the model. The established genome-scale model can be used to understand the growth requirements of the human pathogen S. pyogenes and define optimal and suboptimal conditions, but also to describe differences and similarities between S. pyogenes and related lactic acid bacteria such as L. lactis in order to find strategies to reduce the growth of the pathogen and propose drug targets. PMID:26970054

  14. Analysis of the pathological lesions of the lung in a mouse model of cutaneous infection with Streptococcus pyogenes.

    PubMed

    Minami, Masaaki; Sobue, Sayaka; Ichihara, Masatoshi; Hasegawa, Tadao

    2012-02-01

    Invasive diseases such as toxic shock syndrome caused by Streptococcus pyogenes (S. pyogenes) are re-emerging infectious diseases. The mechanism of pathogenesis is not completely understood although the virulence of this organism has been analyzed using animal model systems, particularly using mice. The analysis of the progression of infection, however, is difficult. Computed tomography (CT) scanning is an extremely powerful technique that we applied to the mouse model of cutaneous infection with S. pyogenes. Two or three days after subcutaneous administration of bacteria, high density reticular areas were detected in the lung by CT. Histopathological examination of the lung was performed to examine the results of CT. Increased numbers of cytokeratin-positive epithelial cells, probably alveolar type II epithelial cells, were detected but no remarkable increase of inflammatory cell infiltrates was observed. Our results show that the pathological lesions of the lung in this model, wherein relatively few numbers of neutrophils were in the alveoli, are well correlated with the lung of a part of streptococcal toxic shock syndrome patients. Therefore, CT may be useful in assessing the progression of S. pyogenes infection, particularly in the pathological lesions of the lung in this model. PMID:22243779

  15. Enzyme-linked immunosorbent assay for detection of type A streptococcal exotoxin: kinetics and regulation during growth of Streptococcus pyogenes.

    PubMed Central

    Houston, C W; Ferretti, J J

    1981-01-01

    We describe the detection and quantitation of type A streptococcal exotoxin (erythrogenic toxin, streptococcal pyrogenic exotoxin) by an enzyme-linked immunosorbent assay. This sensitive and specific technique detected microgram amounts of type A exotoxin and was useful for studying the kinetics and regulation of type A exotoxin production during the growth of Streptococcus pyogenes NY5. Maximum production of type A exotoxin was observed during the mid-log phase of growth, similar to the production of other streptococcal extracellular products. When S. pyogenes NY5 was grown at 42 degrees C, decreases in both growth and type A exotoxin production were observed. The results obtained when we studied the influence of nutrient additives and metal ions on the production of type A exotoxin led to the conclusion that none of these factors significantly affected type A exotoxin synthesis and that regulation was constitutive. Images PMID:7026447

  16. Intra- and Interspecies Signaling between Streptococcus salivarius and Streptococcus pyogenes Mediated by SalA and SalA1 Lantibiotic Peptides

    PubMed Central

    Upton, M.; Tagg, J. R.; Wescombe, P.; Jenkinson, H. F.

    2001-01-01

    Streptococcus salivarius 20P3 produces a 22-amino-acid residue lantibiotic, designated salivaricin A (SalA), that inhibits the growth of a range of streptococci, including all strains of Streptococcus pyogenes. Lantibiotic production is associated with the sal genetic locus comprising salA, the lantibiotic structural gene; salBCTX genes encoding peptide modification and export machinery proteins; and salYKR genes encoding a putative immunity protein and two-component sensor-regulator system. Insertional inactivation of salB in S. salivarius 20P3 resulted in abrogation of SalA peptide production, of immunity to SalA, and of salA transcription. Addition of exogenous SalA peptide to salB mutant cultures induced dose-dependent expression of salA mRNA (0.2 kb), demonstrating that SalA production was normally autoregulated. Inactivation of salR encoding the response regulator of the SalKR two-component system led to reduced production of, and immunity to, SalA. The sal genetic locus was also present in S. pyogenes SF370 (M type 1), but because of a deletion across the salBCT genes, the corresponding lantibiotic peptide, designated SalA1, was not produced. However, in S. pyogenes T11 (M type 4) the sal locus gene complement was apparently complete, and active SalA1 peptide was synthesized. Exogenously added SalA1 peptide from S. pyogenes T11 induced salA1 transcription in S. pyogenes SF370 and in an isogenic S. pyogenes T11 salB mutant and salA transcription in S. salivarius 20P3 salB. Thus, SalA and SalA1 are examples of streptococcal lantibiotics whose production is autoregulated. These peptides act as intra- and interspecies signaling molecules, modulating lantibiotic production and possibly influencing streptococcal population ecology in the oral cavity. PMID:11395456

  17. Bacterial superantigens promote acute nasopharyngeal infection by Streptococcus pyogenes in a human MHC Class II-dependent manner.

    PubMed

    Kasper, Katherine J; Zeppa, Joseph J; Wakabayashi, Adrienne T; Xu, Stacey X; Mazzuca, Delfina M; Welch, Ian; Baroja, Miren L; Kotb, Malak; Cairns, Ewa; Cleary, P Patrick; Haeryfar, S M Mansour; McCormick, John K

    2014-05-01

    Establishing the genetic determinants of niche adaptation by microbial pathogens to specific hosts is important for the management and control of infectious disease. Streptococcus pyogenes is a globally prominent human-specific bacterial pathogen that secretes superantigens (SAgs) as 'trademark' virulence factors. SAgs function to force the activation of T lymphocytes through direct binding to lateral surfaces of T cell receptors and class II major histocompatibility complex (MHC-II) molecules. S. pyogenes invariably encodes multiple SAgs, often within putative mobile genetic elements, and although SAgs are documented virulence factors for diseases such as scarlet fever and the streptococcal toxic shock syndrome (STSS), how these exotoxins contribute to the fitness and evolution of S. pyogenes is unknown. Here we show that acute infection in the nasopharynx is dependent upon both bacterial SAgs and host MHC-II molecules. S. pyogenes was rapidly cleared from the nasal cavity of wild-type C57BL/6 (B6) mice, whereas infection was enhanced up to ∼10,000-fold in B6 mice that express human MHC-II. This phenotype required the SpeA superantigen, and vaccination with an MHC -II binding mutant toxoid of SpeA dramatically inhibited infection. Our findings indicate that streptococcal SAgs are critical for the establishment of nasopharyngeal infection, thus providing an explanation as to why S. pyogenes produces these potent toxins. This work also highlights that SAg redundancy exists to avoid host anti-SAg humoral immune responses and to potentially overcome host MHC-II polymorphisms. PMID:24875883

  18. Vaccine based on a ubiquitous cysteinyl protease and streptococcal pyrogenic exotoxin A protects against Streptococcus pyogenes sepsis and toxic shock

    PubMed Central

    Ulrich, Robert G

    2008-01-01

    Background The gram-positive bacterium Streptococcus pyogenes is a common pathogen of humans that causes invasive infections, toxic-shock syndrome, rheumatic fever, necrotizing fasciitis and other diseases. Detection of antibiotic resistance in clinical isolates has renewed interest in development of new vaccine approaches for control S. pyogenes sepsis. In the study presented, a novel protein vaccine was examined. The vaccine was based on a recombinant protein fusion between streptococcal pyrogenic exotoxin B (SpeB), a cysteinyl protease expressed by all clinical isolates, and streptococcal pyrogenic exotoxin A (SpeA), a superantigen produced by a large subset of isolates. Results A novel protein was produced by mutating the catalytic site of SpeB and the receptor binding surface of SpeA in a fusion of the two polypeptides. Vaccination of HLA-DQ8 transgenic mice with the SpeA-SpeB fusion protein protected against a challenge with the wild-type SpeA that was lethal to naïve controls, and vaccinated mice were protected from an otherwise lethal S. pyogenes infection. Conclusion These results suggest that the genetically attenuated SpeA-SpeB fusion protein may be useful for controlling S. pyogenes infections. Vaccination with the SpeA-SpeB fusion protein described in this study may potentially result in protective immunity against multiple isolates of S. pyogenes due to the extensive antibody cross-reactivity previously observed among all sequence variants of SpeB and the high frequency of SpeA-producing strains. PMID:18976486

  19. The Crystal Structure of Streptococcus pyogenes Uridine Phosphorylase Reveals a Distinct Subfamily of Nucleoside Phosphorylases

    SciTech Connect

    Tran, Timothy H.; Christoffersen, S.; Allan, Paula W.; Parker, William B.; Piskur, Jure; Serra, I.; Terreni, M.; Ealick, Steven E.

    2011-09-20

    Uridine phosphorylase (UP), a key enzyme in the pyrimidine salvage pathway, catalyzes the reversible phosphorolysis of uridine or 2'-deoxyuridine to uracil and ribose 1-phosphate or 2'-deoxyribose 1-phosphate. This enzyme belongs to the nucleoside phosphorylase I superfamily whose members show diverse specificity for nucleoside substrates. Phylogenetic analysis shows Streptococcus pyogenes uridine phosphorylase (SpUP) is found in a distinct branch of the pyrimidine subfamily of nucleoside phosphorylases. To further characterize SpUP, we determined the crystal structure in complex with the products, ribose 1-phosphate and uracil, at 1.8 {angstrom} resolution. Like Escherichia coli UP (EcUP), the biological unit of SpUP is a hexamer with an ?/? monomeric fold. A novel feature of the active site is the presence of His169, which structurally aligns with Arg168 of the EcUP structure. A second active site residue, Lys162, is not present in previously determined UP structures and interacts with O2 of uracil. Biochemical studies of wild-type SpUP showed that its substrate specificity is similar to that of EcUP, while EcUP is {approx}7-fold more efficient than SpUP. Biochemical studies of SpUP mutants showed that mutations of His169 reduced activity, while mutation of Lys162 abolished all activity, suggesting that the negative charge in the transition state resides mostly on uracil O2. This is in contrast to EcUP for which transition state stabilization occurs mostly at O4.

  20. Protective Mechanisms of Respiratory Tract Streptococci against Streptococcus pyogenes Biofilm Formation and Epithelial Cell Infection

    PubMed Central

    Fiedler, Tomas; Riani, Catur; Koczan, Dirk; Standar, Kerstin

    2013-01-01

    Streptococcus pyogenes (group A streptococci [GAS]) encounter many streptococcal species of the physiological microbial biome when entering the upper respiratory tract of humans, leading to the question how GAS interact with these bacteria in order to establish themselves at this anatomic site and initiate infection. Here we show that S. oralis and S. salivarius in direct contact assays inhibit growth of GAS in a strain-specific manner and that S. salivarius, most likely via bacteriocin secretion, also exerts this effect in transwell experiments. Utilizing scanning electron microscopy documentation, we identified the tested strains as potent biofilm producers except for GAS M49. In mixed-species biofilms, S. salivarius dominated the GAS strains, while S. oralis acted as initial colonizer, building the bottom layer in mixed biofilms and thereby allowing even GAS M49 to form substantial biofilms on top. With the exception of S. oralis, artificial saliva reduced single-species biofilms and allowed GAS to dominate in mixed biofilms, although the overall two-layer structure was unchanged. When covered by S. oralis and S. salivarius biofilms, epithelial cells were protected from GAS adherence, internalization, and cytotoxic effects. Apparently, these species can have probiotic effects. The use of Affymetrix array technology to assess HEp-2 cell transcription levels revealed modest changes after exposure to S. oralis and S. salivarius biofilms which could explain some of the protective effects against GAS attack. In summary, our study revealed a protection effect of respiratory tract bacteria against an important airway pathogen and allowed a first in vitro insight into local environmental processes after GAS enter the respiratory tract. PMID:23241973

  1. Changes in Streptococcus pyogenes causing invasive disease in Portugal: evidence for superantigen gene loss and acquisition.

    PubMed

    Friães, Ana; Lopes, Joana P; Melo-Cristino, José; Ramirez, Mario

    2013-12-01

    The emergence of highly virulent and successful Streptococcus pyogenes (group A streptococci - GAS) clones has been attributed to the exchange of virulence factors by lateral gene transfer mechanisms, which strongly contribute to genomic diversity. We characterized a collection of 191 GAS isolates recovered from normally sterile sites in Portugal during 2006-2009 and compared them to invasive isolates obtained during 2000-2005. Antimicrobial resistance rates did not change significantly between the two periods and were generally low. In 2006-2009, emm1, emm89, emm3, and emm6 represented 60% of the isolates. The chromosomally encoded superantigen (SAg) genes speG and smeZ were present in the majority (>90%) of the isolates, while speJ was found in only 45%. The phage encoded SAgs varied greatly in prevalence (2-53%). The distribution of emm types, pulsed-field gel electrophoresis profiling (PFGE) clusters, and SAg profiles changed significantly between the periods, although there were no statistically supported changes in the prevalence of individual types. While the macrolide susceptible clone emm1-T1-ST28 remained dominant (28%), there was a significant decrease in clonal diversity as indicated by both PFGE profiling and emm typing. This was accompanied by intra-clonal divergence of SAg profiles, which was statistically confirmed for isolates representing emm1, emm28, and emm44. This diversification was associated with the loss and acquisition of SAg genes, carried by phages and of chromosomal origin. These data suggest an ongoing genomic diversification of GAS invasive isolates in Portugal that may contribute to the persistence of clones with improved fitness or virulence. PMID:23932912

  2. Differences in the epidemiology between paediatric and adult invasive Streptococcus pyogenes infections.

    PubMed

    Zachariadou, L; Stathi, A; Tassios, P T; Pangalis, A; Legakis, N J; Papaparaskevas, J

    2014-03-01

    In order to investigate for possible differences between paediatric and adult invasive Streptococcus pyogenes (iGAS) infections, a total of 142 cases were identified in 17 Greek hospitals during 2003-2007, of which 96 were children and 46 adults. Bacteraemia, soft tissue infections, streptococcal toxic shock syndrome (STSS), and necrotizing fasciitis were the main clinical presentations (67·6%, 45·1%, 13·4%, and 12·0% of cases, respectively). Bacteraemia and lymphadenitis were significantly more frequent in children (P=0·019 and 0·021, respectively), whereas STSS was more frequent in adults (P=0·017). The main predisposing factors in children were varicella and streptococcal pharyngotonsillitis (25% and 19·8%, respectively), as opposed to malignancy, intravenous drug abuse and diabetes mellitus in adults (19·6%, 15·2% and 10·9%, respectively). Of the two dominant emm-types, 1 and 12 (28·2% and 8·5%, respectively), the proportion of emm-type 12 remained stable during the study period, whereas emm-type 1 rates fluctuated considerably. Strains of emm-type 1 from children were associated with erythromycin susceptibility, STSS and intensive-care-unit admission, whereas emm-type 12 isolates from adults were associated with erythromycin and clindamycin resistance. Finally, specific emm-types were detected exclusively in adults or in children. In conclusion, several clinical and epidemiological differences were detected, that could prove useful in designing age-focused strategies for prevention and treatment of iGAS infections. PMID:23746128

  3. V-ATPase-mediated phagosomal acidification is impaired by Streptococcus pyogenes through Mga-regulated surface proteins.

    PubMed

    Nordenfelt, Pontus; Grinstein, Sergio; Björck, Lars; Tapper, Hans

    2012-11-01

    Streptococcus pyogenes, a significant bacterial pathogen in humans, interferes with the membrane traffic of human neutrophils and survives following phagocytosis. The mechanism(s) behind this property is not known, but in contrast to wild-type bacteria, mutant bacteria lacking virulence factors regulated by the transcriptional regulator Mga, are phagocytosed and killed. In the present work we investigated whether differences in phagosomal acidification may contribute to this difference. Phagosomal pH in neutrophil-differentiated HL-60 cells was studied by fluorescence ratio imaging, and phagosomes containing wild-type S. pyogenes bacteria of the M1 serotype exhibited little or no acidification, whereas Mga mutant bacteria were found in more acidic phagosomes. With phagosomes containing these bacteria, proton delivery was inhibited by adding folimycin, a vacuolar-type adenosine triphosphatase (V-ATPase) inhibitor. This inhibitor had no effect on phagosomes containing wild-type bacteria, indicating either inactivation or removal of V-ATPases by the bacteria. Analysis of isolated bacteria-containing phagosomes confirmed the latter scenario and showed a more efficient delivery of V-ATPases to phagosomes containing Mga mutant bacteria. The results demonstrate that V-ATPase-mediated phagosomal proton delivery is reduced during phagocytosis of wild-type S. pyogenes, leading to impaired acidification, and that surface proteins of the mga regulon are responsible for this effect. PMID:22981599

  4. Streptococcus pyogenes Associated Post-traumatic Brodie’s Abscess of Cuboid: A Case Report and Review of Literature

    PubMed Central

    Amit, Priyadarshi; Maharajan, Karthikeyan; Varma, Bhaskar

    2015-01-01

    Introduction: Brodie’s abscess of cuboid bone is one of the rarest diagnosis in children which most often is hematogenous in origin. Although Streptococcus pyogenes has been uncommonly implicated as causative organism in other bones, it is not yet reported in the cuboid. Case Report: We report the case of 14-year-old boy who presented with a lytic lesion in the cuboid bone. It was preceded by a penetrating injury with a small iron nail. He was treated with simple curettage without the addition of bone graft. Frank pus present in the cavity in the cuboid bone grew S. pyogenes on bacterial culture. Symptoms resolved after 6 weeks of antibiotics, however, complete radiological healing was obtained after 9 months. Conclusion: Although very rare, S. pyogenes associated Brodie’s abscess should strongly be suspected in a posttraumatic lytic lesion in the cuboid bone and bone grafting is not always required for bone healing even in presence of large pus-filled cavity. PMID:27299080

  5. Trading Capsule for Increased Cytotoxin Production: Contribution to Virulence of a Newly Emerged Clade of emm89 Streptococcus pyogenes

    PubMed Central

    Zhu, Luchang; Olsen, Randall J.; Nasser, Waleed; de la Riva Morales, Ivan

    2015-01-01

    ABSTRACT Strains of emm89 Streptococcus pyogenes have become one of the major causes of invasive infections worldwide in the last 10 years. We recently sequenced the genome of 1,125 emm89 strains and identified three major phylogenetic groups, designated clade 1, clade 2, and the epidemic clade 3. Epidemic clade 3 strains, which now cause the great majority of infections, have two distinct genetic features compared to clade 1 and clade 2 strains. First, all clade 3 organisms have a variant 3 nga promoter region pattern, which is associated with increased production of secreted cytolytic toxins SPN (S. pyogenes NADase) and SLO (streptolysin O). Second, all clade 3 strains lack the hasABC locus mediating hyaluronic acid capsule synthesis, whereas this locus is intact in clade 1 and clade 2 strains. We constructed isogenic mutant strains that produce different levels of SPN and SLO toxins and capsule (none, low, or high). Here we report that emm89 strains with elevated toxin production are significantly more virulent than low-toxin producers. Importantly, we also show that capsule production is dispensable for virulence in strains that already produce high levels of SPN and SLO. Our results provide new understanding about the molecular mechanisms contributing to the rapid emergence and molecular pathogenesis of epidemic clade 3 emm89 S. pyogenes. PMID:26443457

  6. The cell envelope-associated protein, LytR, regulates the cysteine protease SpeB in Streptococcus pyogenes.

    PubMed

    Minami, Masaaki; Ichikawa, Mariko; Ohta, Michio; Hasegawa, Tadao

    2012-05-01

    The LytR family of cell envelope-associated transcriptional attenuators in bacteria has been brought into focus of scientific interest on the expression of various virulence factors, as well as bacterial cell envelope maintenance. However, this protein of Streptococcus pyogenes has been only described as cell surface-associated protein, and its function is completely unknown. We created lytR mutant strains from two independent S. pyogenes strains to analyze the function of LytR. The protease assay in culture supernatant showed that lytR mutant had the higher cysteine protease activity than wild-type. Two-dimensional gel electrophoresis and western blotting analysis revealed that the amount of cysteine protease, SpeB in lytR mutant was more compared with that in wild-type. The level of speB mRNA in lytR mutant also increased compared with that of wild-type. The membrane integrity and potential in lytR mutant also were decreased compared with that of wild-type. Murine infection model showed that less survival was detected in mice inoculated with lytR mutant than that with wild-type, and the size of wound lesion of mice with lytR mutant was larger than that with wild-type. Our data suggest that the lytR regulates the expression of SpeB in S. pyogenes with relation to membrane integrity. PMID:22515297

  7. EndoS, a novel secreted protein from Streptococcus pyogenes with endoglycosidase activity on human IgG

    PubMed Central

    Collin, Mattias; Olsén, Arne

    2001-01-01

    Streptococcus pyogenes is an important human pathogen that selectively interacts with proteins involved in the humoral defense system, such as immunoglobulins and complement factors. In this report we show that S.pyogenes has the ability to hydrolyze the chitobiose core of the asparagine-linked glycan on immuno globulin G (IgG) when bacteria are grown in the presence of human plasma. This activity is associated with the secretion of a novel 108 kDa protein denoted EndoS. EndoS has endoglycosidase activity on purified soluble IgG as well as IgG bound to the bacterial surface. EndoS is required for the activity on IgG, as an isogenic EndoS mutant could not hydrolyze the glycan on IgG. In addition, we show that the secreted streptococcal cysteine proteinase SpeB cleaves IgG in the hinge region in a papain-like manner. This is the first example of an endoglycosidase produced by a bacterial pathogen that selectively hydrolyzes human IgG, and reveals a novel mechanism which may contribute to S.pyogenes pathogenesis. PMID:11406581

  8. MALDI-TOF mass spectrometry as a tool for differentiation of invasive and noninvasive Streptococcus pyogenes isolates

    PubMed Central

    Moura, Hercules; Woolfitt, Adrian R; Carvalho, Maria G; Pavlopoulos, Antonis; Teixeira, Lucia M; Satten, Glen A; Barr, John R

    2008-01-01

    A novel mass spectral fingerprinting and proteomics approach using MALDI-TOF MS was applied to detect and identify protein biomarkers of group A Streptococcus (GAS) strains. Streptococcus pyogenes ATCC 700294 genome strain was compared with eight GAS clinical isolates to explore the ability of MALDI-TOF MS to differentiate isolates. Reference strains of other bacterial species were also analyzed and compared with the GAS isolates. MALDI preparations were optimized by varying solvents, matrices, plating techniques, and mass ranges for S. pyogenes ATCC 700294. Spectral variability was tested. A subset of common, characteristic, and reproducible biomarkers in the range of 2000–14 000 Da were detected, and they appeared to be independent of the culture media. Statistical analysis confirmed method reproducibility. Random Forest analysis of all selected GAS isolates revealed differences among most of them, and summed spectra were used for hierarchical cluster analysis. Specific biomarkers were found for each strain, and invasive GAS isolates could be differentiated. GAS isolates from cases of necrotizing fasciitis were clustered together and were distinct from isolates associated with noninvasive infections, despite their sharing the same emm type. Almost 30% of the biomarkers detected were tentatively identified as ribosomal proteins. PMID:18537829

  9. Integration of Genomic and Other Epidemiologic Data to Investigate and Control a Cross-Institutional Outbreak of Streptococcus pyogenes

    PubMed Central

    Chalker, Victoria J.; Smith, Alyson; Al-Shahib, Ali; Botchway, Stella; Macdonald, Emily; Daniel, Roger; Phillips, Sarah; Platt, Steven; Doumith, Michel; Tewolde, Rediat; Coelho, Juliana; Jolley, Keith A.; Underwood, Anthony

    2016-01-01

    Single-strain outbreaks of Streptococcus pyogenes infections are common and often go undetected. In 2013, two clusters of invasive group A Streptococcus (iGAS) infection were identified in independent but closely located care homes in Oxfordshire, United Kingdom. Investigation included visits to each home, chart review, staff survey, microbiologic sampling, and genome sequencing. S. pyogenes emm type 1.0, the most common circulating type nationally, was identified from all cases yielding GAS isolates. A tailored whole-genome reference population comprising epidemiologically relevant contemporaneous isolates and published isolates was assembled. Data were analyzed independently using whole-genome multilocus sequencing and single-nucleotide polymorphism analyses. Six isolates from staff and residents of the homes formed a single cluster that was separated from the reference population by both analytical approaches. No further cases occurred after mass chemoprophylaxis and enhanced infection control. Our findings demonstrate the ability of 2 independent analytical approaches to enable robust conclusions from nonstandardized whole-genome analysis to support public health practice. PMID:27192043

  10. Integration of Genomic and Other Epidemiologic Data to Investigate and Control a Cross-Institutional Outbreak of Streptococcus pyogenes.

    PubMed

    Chalker, Victoria J; Smith, Alyson; Al-Shahib, Ali; Botchway, Stella; Macdonald, Emily; Daniel, Roger; Phillips, Sarah; Platt, Steven; Doumith, Michel; Tewolde, Rediat; Coelho, Juliana; Jolley, Keith A; Underwood, Anthony; McCarthy, Noel D

    2016-06-01

    Single-strain outbreaks of Streptococcus pyogenes infections are common and often go undetected. In 2013, two clusters of invasive group A Streptococcus (iGAS) infection were identified in independent but closely located care homes in Oxfordshire, United Kingdom. Investigation included visits to each home, chart review, staff survey, microbiologic sampling, and genome sequencing. S. pyogenes emm type 1.0, the most common circulating type nationally, was identified from all cases yielding GAS isolates. A tailored whole-genome reference population comprising epidemiologically relevant contemporaneous isolates and published isolates was assembled. Data were analyzed independently using whole-genome multilocus sequencing and single-nucleotide polymorphism analyses. Six isolates from staff and residents of the homes formed a single cluster that was separated from the reference population by both analytical approaches. No further cases occurred after mass chemoprophylaxis and enhanced infection control. Our findings demonstrate the ability of 2 independent analytical approaches to enable robust conclusions from nonstandardized whole-genome analysis to support public health practice. PMID:27192043

  11. Structure and Activity of Streptococcus pyogenes SipA: A Signal Peptidase-Like Protein Essential for Pilus Polymerisation

    PubMed Central

    Young, Paul G.; Proft, Thomas; Harris, Paul W. R.; Brimble, Margaret A.; Baker, Edward N.

    2014-01-01

    The pili expressed on the surface of the human pathogen Streptococcus pyogenes play an important role in host cell attachment, colonisation and pathogenesis. These pili are built from two or three components, an adhesin subunit at the tip, a major pilin that forms a polymeric shaft, and a basal pilin that is attached to the cell wall. Assembly is carried out by specific sortase (cysteine transpeptidase) enzyme. These components are encoded in a small gene cluster within the S. pyogenes genome, often together with another protein, SipA, whose function is unknown. We show through functional assays, carried out by expressing the S. pyogenes pilus components in Lactococcus lactis, SipA from the clinically important M1T1 strain is essential for pilus assembly, and that SipA function is likely to be conserved in all S. pyogenes. From the crystal structure of SipA we confirm that SipA belongs to the family of bacterial signal peptidases (SPases), which process the signal-peptides of secreted proteins. In contrast to a previous arm-swapped SipA dimer, this present structure shows that its principal domain closely resembles the catalytic domain of SPases and has a very similar peptide-binding cleft, but it lacks the catalytic Ser and Lys residues characteristic of SPases. In SipA these are replaced by Asp and Gly residues, which play no part in activity. We propose that SipA functions by binding a key component at the bacterial cell surface, in a conformation that facilitates pilus assembly. PMID:24911348

  12. Fibronectin-binding protein of Streptococcus pyogenes: sequence of the binding domain involved in adherence of streptococci to epithelial cells.

    PubMed Central

    Talay, S R; Valentin-Weigand, P; Jerlström, P G; Timmis, K N; Chhatwal, G S

    1992-01-01

    The sequence of the fibronectin-binding domain of the fibronectin-binding protein of Streptococcus pyogenes (Sfb protein) was determined, and its role in streptococcal adherence was investigated by use of an Sfb fusion protein in adherence studies. A 1-kb DNA fragment coding for the binding domain of Sfb protein was cloned into the expression vector pEX31 to produce an Sfb fusion protein consisting of the N-terminal part of MS2 polymerase and a C-terminal fragment of the streptococcal protein. Induction of the vector promoter resulted in hyperexpression of fibronectin-binding fusion protein in the cytoplasm of the recombinant Escherichia coli cells. Sequence determination of the cloned 1-kb fragment revealed an in-frame reading frame for a 268-amino-acid peptide composed of a 37-amino-acid sequence which is completely repeated three times and incompletely repeated a fourth time. Cloning of one repeat into pEX31 resulted in expression of small fusion peptides that show fibronectin-binding activity, indicating that one repeat contains at least one binding domain. Each repeat exhibits two charged domains and shows high homology with the 38-amino-acid D3 repeat of the fibronectin-binding protein of Staphylococcus aureus. Sequence comparison with other streptococcal ligand-binding surface proteins, including M protein, failed to reveal significant homology, which suggests that Sfb protein represents a novel type of functional protein in S. pyogenes. The Sfb fusion protein isolated from the cytoplasm of recombinant cells was purified by fast protein liquid chromatography. It showed a strong competitive inhibition of fibronectin binding to S. pyogenes and of the adherence of bacteria to cultured epithelial cells. In contrast, purified streptococcal lipoteichoic acid showed only a weak inhibition of fibronectin binding and streptococcal adherence. These results demonstrate that Sfb protein is directly involved in the fibronectin-mediated adherence of S. pyogenes to

  13. Identification and Characterization of a Streptococcus pyogenes Operon Involved in Binding of Hemoproteins and Acquisition of Iron

    PubMed Central

    Bates, Christopher S.; Montañez, Griselle E.; Woods, Charles R.; Vincent, Rebecca M.; Eichenbaum, Zehava

    2003-01-01

    The hemolytic Streptococcus pyogenes can use a variety of heme compounds as an iron source. In this study, we investigate hemoprotein utilization by S. pyogenes. We demonstrate that surface proteins contribute to the binding of hemoproteins to S. pyogenes. We identify an ABC transporter from the iron complex family named sia for streptococcal iron acquisition, which consists of a lipoprotein (siaA), membrane permease (siaB), and ATPase (siaC). The sia transporter is part of a highly conserved, iron regulated, 10-gene operon. SiaA, which was localized to the cell membrane, could specifically bind hemoglobin. The operon's first gene encodes a novel bacterial protein that bound hemoglobin, myoglobin, heme-albumin, and hemoglobin-haptoglobin (but not apo-haptoglobin) and therefore was named Shr, for streptococcal hemoprotein receptor. PhoZ fusion and Western blot analysis showed that Shr has a leader peptide and is found in both membrane-bound and soluble forms. An M1 SF370 strain with a polar mutation in shr was more resistant to streptonigrin and hydrogen peroxide, suggesting decreased iron uptake. The addition of hemoglobin to the culture medium increased cell resistance to hydrogen peroxide in SF370 but not in the mutant, implying the sia operon may be involved in hemoglobin-dependent resistance to oxidative stress. The shr mutant demonstrated reduced hemoglobin binding, though cell growth in iron-depleted medium supplemented with hemoglobin, whole blood, or ferric citrate was not affected, suggesting additional systems are involved in hemoglobin utilization. SiaA and Shr are the first hemoprotein receptors identified in S. pyogenes; their possible role in iron capture is discussed. PMID:12595414

  14. Insidious manifestation of pyogenic liver abscess caused by Streptococcus intermedius and Micrococcus luteus: a case report.

    PubMed

    Ioannou, Antreas; Xenophontos, Eleni; Karatsi, Alexandra; Petrides, Christos; Kleridou, Maro; Zintilis, Chrysostomos

    2016-01-01

    Pyogenic liver abscesses are caused by various microorganisms and usually present with fever, abdominal pain, leukocytosis and liver enzyme abnormalities. This case presents the insidious manifestation of a pyogenic liver abscess in a 34-year-old immunocompetent male, where classical manifestations of a liver abscess were absent. The microorganisms cultured from the abscess belonged to oral cavity's and gastrointestinal tract's normal flora. PMID:26770811

  15. Insidious manifestation of pyogenic liver abscess caused by Streptococcus intermedius and Micrococcus luteus: a case report

    PubMed Central

    Ioannou, Antreas; Xenophontos, Eleni; Karatsi, Alexandra; Petrides, Christos; Kleridou, Maro; Zintilis, Chrysostomos

    2016-01-01

    Pyogenic liver abscesses are caused by various microorganisms and usually present with fever, abdominal pain, leukocytosis and liver enzyme abnormalities. This case presents the insidious manifestation of a pyogenic liver abscess in a 34-year-old immunocompetent male, where classical manifestations of a liver abscess were absent. The microorganisms cultured from the abscess belonged to oral cavity's and gastrointestinal tract's normal flora. PMID:26770811

  16. The NADase-Negative Variant of the Streptococcus pyogenes Toxin NAD+ Glycohydrolase Induces JNK1-Mediated Programmed Cellular Necrosis

    PubMed Central

    Chandrasekaran, Sukantha

    2016-01-01

    ABSTRACT Virulence factors are often multifunctional and contribute to pathogenesis through synergistic mechanisms. For the human pathogen Streptococcus pyogenes, two factors that act synergistically are the S. pyogenes NAD+ glycohydrolase (SPN) and streptolysin O (SLO). Through distinct mechanisms, SLO forms pores in host cell membranes and translocates SPN into the host cell cytosol. Two natural variants of SPN exist, one that exhibits NADase activity and one that lacks this function, and both versions are translocated and act in concert with SLO to cause an accelerated death response in epithelial cells. While NADase+ SPN is known to trigger a metabolic form of necrosis through the depletion of NAD+, the mechanism by which NADase− SPN induces cell death was unknown. In the studies described here, we examined the pathway of NADase− cell death through analysis of activation patterns of mitogen-activated protein kinases (MAPKs). S. pyogenes infection resulted in activation of members of three MAPK subfamilies (p38, ERK, and JNK). However, only JNK was activated in an SLO-specific manner. NADase− SPN induced necrosis in HeLa epithelial cells associated with depolarization of mitochondrial membranes, activation of NF-κB, and the generation of reactive oxygen species. Remarkably, RNA interference (RNAi) silencing of JNK protected cells from NADase−-SPN-mediated necrosis, suggesting that NADase− SPN triggers a form of programmed necrosis dependent on JNK signaling. Taken together, these data demonstrate that SPN acts with SLO to elicit necrosis through two different mechanisms depending on its NADase activity, i.e., metabolic (NADase+) or programmed (NADase−), leading to distinct inflammatory profiles. PMID:26838722

  17. Identification of a divergent M protein gene and an M protein-related gene family in Streptococcus pyogenes serotype 49.

    PubMed Central

    Haanes, E J; Cleary, P P

    1989-01-01

    The antigenically variant M protein of Streptococcus pyogenes enhances virulence by promoting resistance to phagocytosis. The serum opacity factor (OF), produced by a subset of M serotypes, is also antigenically variant, and its antigenic variability exactly parallels that of M protein. OF-positive and OF-negative streptococci are also phenotypically distinguishable by a number of other criteria. In order to study the differences between OF-positive and OF-negative streptococci, we cloned and sequenced the type 49 M protein gene (emm49), the first to be cloned from an OF-positive strain. This gene showed evolutionary divergence from the OF-negative M protein genes studied previously. Furthermore, emm49 was part of a gene family, in contrast to the single-copy nature of previously characterized M protein genes. Images PMID:2687231

  18. Identifying protective Streptococcus pyogenes vaccine antigens recognized by both B and T cells in human adults and children

    PubMed Central

    Mortensen, Rasmus; Nissen, Thomas Nørrelykke; Fredslund, Sine; Rosenkrands, Ida; Christensen, Jan Pravsgaard; Andersen, Peter; Dietrich, Jes

    2016-01-01

    No commercial vaccine exists against Group A streptococci (GAS; Streptococcus pyogenes) and only little is known about anti-GAS protective immunity. In our effort to discover new protective vaccine candidates, we selected 21 antigens based on an in silico evaluation. These were all well-conserved among different GAS strains, upregulated in host-pathogen interaction studies, and predicted to be extracellular or associated with the surface of the bacteria. The antigens were tested for both antibody recognition and T cell responses in human adults and children. The antigenicity of a selected group of antigens was further validated using a high-density peptide array technology that also identified the linear epitopes. Based on immunological recognition, four targets were selected and tested for protective capabilities in an experimental GAS infection model in mice. Shown for the first time, three of these targets (spy0469, spy1228 and spy1801) conferred significant protection whereas one (spy1643) did not. PMID:26911649

  19. Identifying protective Streptococcus pyogenes vaccine antigens recognized by both B and T cells in human adults and children.

    PubMed

    Mortensen, Rasmus; Nissen, Thomas Nørrelykke; Fredslund, Sine; Rosenkrands, Ida; Christensen, Jan Pravsgaard; Andersen, Peter; Dietrich, Jes

    2016-01-01

    No commercial vaccine exists against Group A streptococci (GAS; Streptococcus pyogenes) and only little is known about anti-GAS protective immunity. In our effort to discover new protective vaccine candidates, we selected 21 antigens based on an in silico evaluation. These were all well-conserved among different GAS strains, upregulated in host-pathogen interaction studies, and predicted to be extracellular or associated with the surface of the bacteria. The antigens were tested for both antibody recognition and T cell responses in human adults and children. The antigenicity of a selected group of antigens was further validated using a high-density peptide array technology that also identified the linear epitopes. Based on immunological recognition, four targets were selected and tested for protective capabilities in an experimental GAS infection model in mice. Shown for the first time, three of these targets (spy0469, spy1228 and spy1801) conferred significant protection whereas one (spy1643) did not. PMID:26911649

  20. [Invasive disease due to Streptococcus pyogenes in a patient with A H1N1 influenza infection. Report of one case].

    PubMed

    Guerrero S, Gonzalo; Marín S, Felipe

    2015-08-01

    Bacterial superinfection is a known complication among patients affected by viral respiratory tract infections. Streptococcus pyogenes, a major bacterial agent involved in acute tonsillopharyngitis, skin and soft tissue infections, was reported as a co-infecting microorganism during the 2009 A H1N1 influenza pandemic. We report a 65-year-old male patient who evolved with multifocal pneumonia and multiple organ failure with a fatal outcome. Influenza A H1N1 was detected by a polymerase chain reaction-based technique from a tracheal aspirate sample. S. pyogenes was identified by a rapid test from a nasopharyngeal sample and isolated afterwards from a positive blood culture. PMID:26436938

  1. Crystallization and preliminary X-ray crystallographic analysis of the tRNA-specific adenosine deaminase from Streptococcus pyogenes

    SciTech Connect

    Ku, Min-Je; Lee, Won-Ho; Nam, Ki-hyun; Rhee, Kyeong-hee; Lee, Ki-Seog; Kim, Eunice EunKyung; Yu, Myung-Hee; Hwang, Kwang Yeon

    2005-04-01

    The tRNA-specific adenosine deaminase from the pathogenic bacteria S. pyogenes has been overexpressed and crystallized. The tRNA-specific adenosine deaminase from the pathogenic bacteria Streptococcus pyogenes (spTAD) has been overexpressed in Escherichia coli and crystallized in the presence of Zn{sup 2+} ion at 295 K using ammonium sulfate as a precipitant. Flash-cooled crystals of spTAD diffracted to 2.0 Å using 30%(v/v) glycerol as a cryoprotectant. X-ray diffraction data have been collected to 2.0 Å using synchrotron radiation. The crystal belongs to the tetragonal space group P4{sub 2}2{sub 1}2, with unit-cell parameters a = b = 81.042, c = 81.270 Å. The asymmetric unit contains one subunit of spTAD, with a corresponding crystal volume per protein weight (V{sub M}) of 3.3 Å{sup 3} Da{sup −1} and a solvent content of 62.7%.

  2. The YvqE two-component system controls biofilm formation and acid production in Streptococcus pyogenes.

    PubMed

    Isaka, Masanori; Tatsuno, Ichiro; Maeyama, Jun-Ichi; Matsui, Hideyuki; Zhang, Yan; Hasegawa, Tadao

    2016-07-01

    In Streptococcus pyogenes, proteins involved in determining virulence are controlled by stand-alone response regulators and by two-component regulatory systems. Previous studies reported that, compared to the parental strain, the yvqE sensor knockout strain showed significantly reduced growth and lower virulence. To determine the function of YvqE, we performed biofilm analysis and pH assays on yvqE mutants, and site-directed mutagenesis of YvqE. The yvqE deletion mutant showed a slower acid production rate, indicating that YvqE regulates acid production from sugar fermentation. The mutant strain, in which the Asp(26) residue in YvqE was replaced with Asn, affected biofilm formation, suggesting that this amino acid senses hydrogen ions produced by fermentative sugar metabolism. Signals received by YvqE were directly or indirectly responsible for inducing pilus expression. This study shows that at low environmental pH, biofilm formation in S. pyogenes is mediated by YvqE and suggests that regulation of pilus expression by environmental acidification could be directly under the control of YvqE. PMID:27061781

  3. Contribution of CsrR-Regulated Virulence Factors to the Progress and Outcome of Murine Skin Infections by Streptococcus pyogenes

    PubMed Central

    Engleberg, N. Cary; Heath, Andrew; Vardaman, Kristal; DiRita, Victor J.

    2004-01-01

    Streptococcus pyogenes with null mutations in the csrRS regulatory locus are highly virulent in mice due to derepression of hyaluronic acid capsule synthesis and exotoxins, e.g., streptolysin S (SLS) and pyrogenic exotoxin B (SpeB). We generated derivatives of a ΔcsrRS strain that also carry deletions in hasAB (leading to an acapsular phenotype) or in sagA (phenotypically SLS−) or an interruption of speB (SpeB−) to test the relative contributions of these factors to the development of necrotic skin lesions. Inoculation of 2 × 106 to 4 × 106 CFU of either acapsular or SLS− strains into hairless mice resulted in lesions ∼70% smaller than those of the ΔcsrRS parent strain. Elimination of SLS also reduced lethality from 100% to 0% at this inoculum (P < 10−7; Fisher exact test). In contrast, SLS+ SpeB− mutants yielded lesions that were only 41% smaller than the parent strain (t = 2.2; P = 0.04), but only 3 the 17 lesions had dermal sloughing (P = 10−5). The nonulcerative lesions associated with SpeB− strains appeared pale with surrounding erythema. We conclude that capsule and SLS contribute to the subcutaneous spread of S. pyogenes and to a fatal outcome of infection. SpeB facilitates early dermal ulceration but has minor influence on lesion size and mortality. Large ulcerative lesions are observed only when both toxins are present. PMID:14742501

  4. Role of M3 protein in the adherence and internalization of an invasive Streptococcus pyogenes strain by epithelial cells.

    PubMed

    Eyal, Osnat; Jadoun, Jeries; Bitler, Arcady; Skutelski, Ehud; Sela, Shlomo

    2003-10-15

    Streptococcus pyogenes utilizes multiple mechanisms for adherence to and internalization by epithelial cells. One of the molecules suggested of being involved in adherence and internalization is the M protein. Although strains of the M3 serotype form the second largest group isolated from patients with severe invasive diseases and fatal infections, not much information is known regarding the interactions of M3 protein with mammalian cells. In this study we have constructed an emm3 mutant of an invasive M3 serotype (SP268), and demonstrated that the M3 protein is involved in both adherence to and internalization by HEp-2 cells. Fibronectin promoted both adherence and internalization of SP268 in an M3-independent pathway. Utilizing speB and speB/emm3 double mutants, it was found that M3 protein is not essential for the maturation of SpeB, as was reported for the M1 protein. Increased internalization efficiency observed in both the speB and emm3/speB mutants suggested that inhibition of S. pyogenes internalization by SpeB is not related to the presence of an intact M3 protein. Thus, other proteins in SP268, which serve as targets for SpeB activity, have a prominent role in the internalization process. PMID:14522456

  5. Contribution of CsrR-regulated virulence factors to the progress and outcome of murine skin infections by Streptococcus pyogenes.

    PubMed

    Engleberg, N Cary; Heath, Andrew; Vardaman, Kristal; DiRita, Victor J

    2004-02-01

    Streptococcus pyogenes with null mutations in the csrRS regulatory locus are highly virulent in mice due to derepression of hyaluronic acid capsule synthesis and exotoxins, e.g., streptolysin S (SLS) and pyrogenic exotoxin B (SpeB). We generated derivatives of a DeltacsrRS strain that also carry deletions in hasAB (leading to an acapsular phenotype) or in sagA (phenotypically SLS-) or an interruption of speB (SpeB-) to test the relative contributions of these factors to the development of necrotic skin lesions. Inoculation of 2 x 10(6) to 4 x 10(6) CFU of either acapsular or SLS- strains into hairless mice resulted in lesions approximately 70% smaller than those of the DeltacsrRS parent strain. Elimination of SLS also reduced lethality from 100% to 0% at this inoculum (P < 10(-7); Fisher exact test). In contrast, SLS+ SpeB- mutants yielded lesions that were only 41% smaller than the parent strain (t = 2.2; P = 0.04), but only 3 the 17 lesions had dermal sloughing (P = 10(-5)). The nonulcerative lesions associated with SpeB- strains appeared pale with surrounding erythema. We conclude that capsule and SLS contribute to the subcutaneous spread of S. pyogenes and to a fatal outcome of infection. SpeB facilitates early dermal ulceration but has minor influence on lesion size and mortality. Large ulcerative lesions are observed only when both toxins are present. PMID:14742501

  6. Association of phenotypic and genotypic characteristics of invasive Streptococcus pyogenes isolates with clinical components of streptococcal toxic shock syndrome.

    PubMed Central

    Talkington, D F; Schwartz, B; Black, C M; Todd, J K; Elliott, J; Breiman, R F; Facklam, R R

    1993-01-01

    Sixty-two invasive Streptococcus pyogenes strains, including 32 strains isolated from patients with streptococcal toxic shock syndrome (STSS), were analyzed for the following phenotypic and genotypic characteristics: M-protein type, serum opacity factor production, protease production, the presence of streptococcal pyrogenic exotoxin (Spe) genes A, B, and C, and in vitro production of SpeA and SpeB. These characteristics were analyzed for possible associations with each other as well as with clinical components of STSS. M-type 1, the most commonly isolated M-type, was significantly associated with protease production. Protease activity was significantly associated with the clinical sign of soft tissue necrosis. M-type 1 and 3 strains from STSS patients were significantly associated with the clinical signs of shock and organ involvement as well as with SpeA production in vitro. Finally, the production of SpeA was significantly associated with the clinical component of shock and organ involvement as well as with rash. These data suggest that STSS does not make up a single syndrome but, rather, that the multiple STSS clinical criteria probably reflect different phenotypic characteristics of individual S. pyogenes isolates. PMID:8335368

  7. The fibronectin-binding protein of Streptococcus pyogenes, SfbI, is involved in the internalization of group A streptococci by epithelial cells.

    PubMed

    Molinari, G; Talay, S R; Valentin-Weigand, P; Rohde, M; Chhatwal, G S

    1997-04-01

    Streptococcus pyogenes organisms (group A streptococci) are considered to be highly adhesive extracellular pathogens. However, it has recently been reported that S. pyogenes has the capacity to efficiently invade eukaryotic cells. In this study, we demonstrate that the interaction of S. pyogenes fibronectin-binding protein (SfbI) with fibronectin on nonphagocytic HEp-2 cells triggers bacterial internalization. Blocking of the SfbI adhesin by either antibodies against the whole protein or antibodies against the fibronectin-binding domains of SfbI, as well as pretreatment of HEp-2 cells with purified SfbI protein, prevents both S. pyogenes attachment and internalization. Inert latex beads precoated with the purified SfbI protein are ingested by eukaryotic cells, demonstrating that SfbI is per se enough to trigger the internalization process. Experiments performed with a recombinant SfbI domain encompassing the two fibronectin-binding regions of the SfbI molecule demonstrated that these binding regions are essential and sufficient to activate uptake by HEp-2 cells. These results demonstrate that the fibronectin-binding protein SfbI is involved in both S. pyogenes' attachment to and ingestion by HEp-2 cells and contribute to elucidation of the underlying molecular events leading to eukaryotic cell invasion by S. pyogenes. PMID:9119474

  8. A novel superantigen isolated from pathogenic strains of Streptococcus pyogenes with aminoterminal homology to staphylococcal enterotoxins B and C.

    PubMed Central

    Mollick, J A; Miller, G G; Musser, J M; Cook, R G; Grossman, D; Rich, R R

    1993-01-01

    Streptococcus pyogenes (group A Streptococcus) has re-emerged in recent years as a cause of severe human disease. Because extracellular products are involved in streptococcal pathogenesis, we explored the possibility that a disease isolate expresses an uncharacterized superantigen. We screened culture supernatants for superantigen activity with a major histocompatibility complex class II-dependent T cell proliferation assay. Initial fractionation with red dye A chromatography indicated production of a class II-dependent T cell mitogen by a toxic shock-like syndrome (TSLS) strain. The amino terminus of the purified streptococcal superantigen was more homologous to the amino termini of staphylococcal enterotoxins B, C1, and C3 (SEB, SEC1, and SEC3), than to those of pyrogenic exotoxins A, B, C or other streptococcal toxins. The molecule, designated SSA, had the same pattern of class II isotype usage as SEB in T cell proliferation assays. However, it differed in its pattern of human T cell activation, as measured by quantitative polymerase chain reaction with V beta-specific primers. SSA activated human T cells that express V beta 1, 3, 15 with a minor increase of V beta 5.2-bearing cells, whereas SEB activated V beta 3, 12, 15, and 17-bearing T cells. Immunoblot analysis of 75 disease isolates from several localities detected SSA production only in group A streptococci, and found that SSA is apparently confined to only three clonal lineages as defined by multilocus enzyme electrophoresis typing. Isolates of one of these lineages, (electrophoretic type 2) are strongly associated with TSLS. The data identify SSA as a novel streptococcal superantigen that appears to be more related structurally to staphylococcal enterotoxins than to streptococcal exotoxins. Because abundant SSA production is apparently confined to only three streptococcal clonal lineages, the data also suggest that the SSA gene has only recently been acquired by S. pyogenes. Images PMID:8349810

  9. Activities of a New Fluoroketolide, HMR 3787, and Its (Des)-Fluor Derivative RU 64399 Compared to Those of Telithromycin, Erythromycin A, Azithromycin, Clarithromycin, and Clindamycin against Macrolide-Susceptible or -Resistant Streptococcus pneumoniae and S. pyogenes

    PubMed Central

    Nagai, Kensuke; Davies, Todd A.; Ednie, Lois M.; Bryskier, Andre; Palavecino, Elizabeth; Jacobs, Michael R.; Appelbaum, Peter C.

    2001-01-01

    Activities of HMR 3787 and RU 64399 were compared to those of three macrolides, telithromycin, and clindamycin against 175 Streptococcus pneumoniae isolates and 121 Streptococcus pyogenes isolates. HMR3787 and telithromycin were the most active compounds tested against pneumococci. Telithromycin and RU 64399 were equally active against macrolide-susceptible (MICs, 0.008 to 0.06 μg/ml) and -resistant S. pyogenes isolates, but HMR 3787 had lower MICs for ermB strains. PMID:11600391

  10. Citrulline Protects Streptococcus pyogenes from Acid Stress Using the Arginine Deiminase Pathway and the F1Fo-ATPase

    PubMed Central

    Cusumano, Zachary T.

    2015-01-01

    ABSTRACT A common stress encountered by both pathogenic and environmental bacteria is exposure to a low-pH environment, which can inhibit cell growth and lead to cell death. One major defense mechanism against this stress is the arginine deiminase (ADI) pathway, which catabolizes arginine to generate two ammonia molecules and one molecule of ATP. While this pathway typically relies on the utilization of arginine, citrulline has also been shown to enter into the pathway and contribute to protection against acid stress. In the pathogenic bacterium Streptococcus pyogenes, the utilization of citrulline has been demonstrated to contribute to pathogenesis in a murine model of soft tissue infection, although the mechanism underlying its role in infection is unknown. To gain insight into this question, we analyzed a panel of mutants defective in different steps in the ADI pathway to dissect how arginine and citrulline protect S. pyogenes in a low-pH environment. While protection provided by arginine utilization occurred through the buffering of the extracellular environment, citrulline catabolism protection was pH independent, requiring the generation of ATP via the ADI pathway and a functional F1Fo-ATP synthase. This work demonstrates that arginine and citrulline catabolism protect against acid stress through distinct mechanisms and have unique contributions to virulence during an infection. IMPORTANCE An important aspect of bacterial pathogenesis is the utilization of host-derived nutrients during an infection for growth and virulence. Previously published work from our lab identified a unique role for citrulline catabolism in Streptococcus pyogenes during a soft tissue infection. The present article probes the role of citrulline utilization during this infection and its contribution to protection against acid stress. This work reveals a unique and concerted action between the catabolism of citrulline and the F1Fo-ATPase that function together to provide protection for

  11. [Distribution of emm genotypes and antibiotic susceptibility of Streptococcus pyogenes strains: analogy with the vaccine in development].

    PubMed

    Arslan, Uğur; Oryaşın, Erman; Eskin, Zeynep; Türk Dağı, Hatice; Fındık, Duygu; Tuncer, Inci; Bozdoğan, Bülent

    2013-04-01

    Streptococcus pyogenes is the most common bacterial pathogen causing pharyngotonsillitis, and also can lead to diseases such as otitis media, impetigo, necrotizing fasciitis, bacteremia, sepsis and toxic shock-like syndrome. M protein encoded by emm gene is an important virulence factor of S.pyogenes and it is used for genotyping in epidemiological studies. The aims of this study were to determine the M protein types of group A streptococci (GAS) by using emm gene sequence analysis method, to compare the M types in terms of analogy with the vaccine in development and to determine the antibiotic susceptibilities of the isolates. A total of 35 GAS strains isolated from various clinical specimens in our laboratory were included in the study. Strains growing in blood culture were considered as invasive, strains growing in throat and abscess cultures were considered as non-invasive. The isolates have been identified by conventional methods and 16S rRNA sequence analysis at species level. emm genotyping of strains identified as S.pyogenes, was performed by PCR method as proposed by the CDC. Amplicons were obtained and sequenced in 23 out of 35 isolates. The results were compared with CDC emm sequence database. Antibiotic susceptibility of the isolates was performed by agar dilution method and evaluated as recommended by CLSI. Twenty-three out of 35 isolates could be typed and 15 different emm genotypes were detected. The most common emm types were emm1 (22%), emm89 (13%), emm18 (9%) and emm19 (9%). The detection rate of other emm types (emm5, 12, 14, 17, 26, 29, 37, 74, 78, 92, 99) was 47%. Types emm1, 12, 19, 74, 89 and 99 were observed in strains isolated from blood cultures. It was detected that nine of the 15 (60%) emm types are within the contents of 26 valent vaccine (emm 1, 5, 12, 14, 18, 19, 29, 89, 92). It was also observed that 17 (74%) of the 23 cases were infected by vaccine types and the four emm types (emm1, 12, 19, 89) identified in blood samples were

  12. Effects of the ERES pathogenicity region regulator Ralp3 on Streptococcus pyogenes serotype M49 virulence factor expression.

    PubMed

    Siemens, Nikolai; Fiedler, Tomas; Normann, Jana; Klein, Johannes; Münch, Richard; Patenge, Nadja; Kreikemeyer, Bernd

    2012-07-01

    Streptococcus pyogenes (group A streptococcus [GAS]) is a highly virulent Gram-positive bacterium. For successful infection, GAS expresses many virulence factors, which are clustered together with transcriptional regulators in distinct genomic regions. Ralp3 is a central regulator of the ERES region. In this study, we investigated the role of Ralp3 in GAS M49 pathogenesis. The inactivation of Ralp3 resulted in reduced attachment to and internalization into human keratinocytes. The Δralp3 mutant failed to survive in human blood and serum, and the hyaluronic acid capsule was slightly decreased. In addition, the mutant showed a lower binding capacity to human plasminogen, and the SpeB activity was significantly decreased. Complementation of the Δralp3 mutant restored the wild-type phenotype. The transcriptome and quantitative reverse transcription-PCR analysis of the serotype M49 GAS strain and its isogenic Δralp3 mutant identified 16 genes as upregulated, and 43 genes were found to be downregulated. Among the downregulated genes, there were open reading frames encoding proteins involved in metabolism (e.g., both lac operons and the fru operon), genes encoding lantibiotics (e.g., the putative salivaricin operon), and ORFs encoding virulence factors (such as the whole Mga core regulon and further genes under Mga control). In summary, the ERES region regulator Ralp3 is an important serotype-specific transcriptional regulator for virulence and metabolic control. PMID:22544273

  13. Epidemiology Analysis of Streptococcus pyogenes in a Hospital in Southern Taiwan by Use of the Updated emm Cluster Typing System

    PubMed Central

    Zheng, Po-Xing; Wang, Shu-Ying; Tsai, Pei-Jane; Chuang, Woei-Jer; Lin, Yee-Shin; Liu, Ching-Chuan

    2015-01-01

    emm typing is the most widely used molecular typing method for the human pathogen Streptococcus pyogenes (group A streptococcus [GAS]). emm typing is based on a small variable region of the emm gene; however, the emm cluster typing system defines GAS types according to the nearly complete sequence of the emm gene. Therefore, emm cluster typing is considered to provide more information regarding the functional and structural properties of M proteins in different emm types of GAS. In the present study, 677 isolates collected between 1994 and 2008 in a hospital in southern Taiwan were analyzed by the emm cluster typing system. emm clusters A-C4, E1, E6, and A-C3 were the most prevalent emm cluster types and accounted for 67.4% of total isolates. emm clusters A-C4 and E1 were associated with noninvasive diseases, whereas E6 was significantly associated with both invasive and noninvasive manifestations. In addition, emm clusters D4, E2, and E3 were significantly associated with invasive manifestations. Furthermore, we found that the functional properties of M protein, including low fibrinogen-binding and high IgG-binding activities, were correlated significantly with invasive manifestations. In summary, the present study provides updated epidemiological information on GAS emm cluster types in southern Taiwan. PMID:26560544

  14. Superoxide anions produced by Streptococcus pyogenes group A-stimulated keratinocytes are responsible for cellular necrosis and bacterial growth inhibition.

    PubMed

    Regnier, Elodie; Grange, Philippe A; Ollagnier, Guillaume; Crickx, Etienne; Elie, Laetitia; Chouzenoux, Sandrine; Weill, Bernard; Plainvert, Céline; Poyart, Claire; Batteux, Frédéric; Dupin, Nicolas

    2016-02-01

    Gram-positive Streptococcus pyogenes (group A Streptococcus or GAS) is a major skin pathogen and interacts with keratinocytes in cutaneous tissues. GAS can cause diverse suppurative and inflammatory infections, such as cellulitis, a common acute bacterial dermo-hypodermitis with a high morbidity. Bacterial isolation yields from the lesions are low despite the strong local inflammation observed, raising numerous questions about the pathogenesis of the infection. Using an in vitro model of GAS-infected keratinocytes, we show that the major ROS produced is the superoxide anion ([Formula: see text]), and that its production is time- and dose-dependent. Using specific modulators of ROS production, we show that [Formula: see text] is mainly synthesized by the cytoplasmic NADPH oxidase. Superoxide anion production leads to keratinocyte necrosis but incomplete inhibition of GAS growth, suggesting that GAS may be partially resistant to the oxidative burst. In conclusion, GAS-stimulated keratinocytes are able to develop an innate immune response based on the production of ROS. This local immune response limits GAS development and induces keratinocyte cell death, resulting in the skin lesions observed in patients with cellulitis. PMID:26621818

  15. Necrotizing soft tissue infections caused by Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis of groups C and G in western Norway.

    PubMed

    Bruun, T; Kittang, B R; de Hoog, B J; Aardal, S; Flaatten, H K; Langeland, N; Mylvaganam, H; Vindenes, H A; Skrede, S

    2013-12-01

    Streptococcus pyogenes (group A streptococcus, GAS) is a major cause of necrotizing soft tissue infection (NSTI). On rare occasions, other β-haemolytic streptococci may also cause NSTI, but the significance and nature of these infections has not been thoroughly investigated. In this study, clinical and molecular characteristics of NSTI caused by GAS and β-haemolytic Streptococcus dysgalactiae subsp. equisimilis of groups C and G (GCS/GGS) in western Norway during 2000-09 are presented. Clinical data were included retrospectively. The bacterial isolates were subsequently emm typed and screened for the presence of genes encoding streptococcal superantigens. Seventy cases were identified, corresponding to a mean annual incidence rate of 1.4 per 100 000. Sixty-one of the cases were associated with GAS, whereas GCS/GGS accounted for the remaining nine cases. The in-hospital case fatality rates of GAS and GCS/GGS disease were 11% and 33%, respectively. The GCS/GGS patients were older, had comorbidities more often and had anatomically more superficial disease than the GAS patients. High age and toxic shock syndrome were associated with mortality. The Laboratory Risk Indicator for Necrotizing Fasciitis laboratory score showed high values (≥6) in only 31 of 67 cases. Among the available 42 GAS isolates, the most predominant emm types were emm1, emm3 and emm4. The virulence gene profiles were strongly correlated to emm type. The number of superantigen genes was low in the four available GCS/GGS isolates. Our findings indicate a high frequency of streptococcal necrotizing fasciitis in our community. GCS/GGS infections contribute to the disease burden, but differ from GAS cases in frequency and predisposing factors. PMID:23795951

  16. Complete Genome Sequence of emm28 Type Streptococcus pyogenes MEW123, a Streptomycin-Resistant Derivative of a Clinical Throat Isolate Suitable for Investigation of Pathogenesis

    PubMed Central

    Jacob, Kristin M.; Spilker, Theodore; LiPuma, John J.; Dawid, Suzanne R.

    2016-01-01

    We present here the complete genome sequence of Streptococcus pyogenes type emm28 strain MEW123, a streptomycin-resistant derivative of a pediatric throat isolate. The genome length is 1,878,699 bp, with 38.29% G+C% content. The genome sequence adds value to this virulent emm28 representative strain and will aid in the investigation of streptococcal pathogenesis. PMID:26988051

  17. Intergenic Variable-Number Tandem-Repeat Polymorphism Upstream of rocA Alters Toxin Production and Enhances Virulence in Streptococcus pyogenes.

    PubMed

    Zhu, Luchang; Olsen, Randall J; Horstmann, Nicola; Shelburne, Samuel A; Fan, Jia; Hu, Ye; Musser, James M

    2016-07-01

    Variable-number tandem-repeat (VNTR) polymorphisms are ubiquitous in bacteria. However, only a small fraction of them has been functionally studied. Here, we report an intergenic VNTR polymorphism that confers an altered level of toxin production and increased virulence in Streptococcus pyogenes The nature of the polymorphism is a one-unit deletion in a three-tandem-repeat locus upstream of the rocA gene encoding a sensor kinase. S. pyogenes strains with this type of polymorphism cause human infection and produce significantly larger amounts of the secreted cytotoxins S. pyogenes NADase (SPN) and streptolysin O (SLO). Using isogenic mutant strains, we demonstrate that deleting one or more units of the tandem repeats abolished RocA production, reduced CovR phosphorylation, derepressed multiple CovR-regulated virulence factors (such as SPN and SLO), and increased virulence in a mouse model of necrotizing fasciitis. The phenotypic effect of the VNTR polymorphism was nearly the same as that of inactivating the rocA gene. In summary, we identified and characterized an intergenic VNTR polymorphism in S. pyogenes that affects toxin production and virulence. These new findings enhance understanding of rocA biology and the function of VNTR polymorphisms in S. pyogenes. PMID:27141081

  18. Evaluation of novel Streptococcus pyogenes vaccine candidates incorporating multiple conserved sequences from the C-repeat region of the M-protein.

    PubMed

    Bauer, Michelle J; Georgousakis, Melina M; Vu, Therese; Henningham, Anna; Hofmann, Andreas; Rettel, Mandy; Hafner, Louise M; Sriprakash, Kadaba S; McMillan, David J

    2012-03-01

    A major challenge for Streptococcus pyogenes vaccine development is the identification of epitopes that confer protection from infection by multiple S. pyogenes M-types. Here we have identified and characterised the distribution of common variant sequences from individual repeat units of the C-repeat region (CRR) of M-proteins representing 77 different M-types. Three polyvalent fusion vaccine candidates (SV1, SV2 and SV3) incorporating the most common variants were subsequently expressed and purified, and demonstrated to be alpha-helical by Circular Dichroism (CD), a secondary conformational characteristic of the CRR in the M-protein. Antibodies raised against each of these constructs recognise M-proteins that vary in their CRR, and bind to the surface of multiple S. pyogenes isolates. Antibodies raised against SV1, containing five variant sequences, also kill heterologous S. pyogenes isolates in in vitro bactericidal assays. Further structural characterisation of this construct demonstrated the conformation of SV1 was stable at different pHs, and thermal unfolding of SV1 is a reversible process. Our findings demonstrate that linkage of multiple variant sequences into a single recombinant construct overcomes the need to embed the variant sequences in foreign helix promoting flanking sequences for conformational stability, and demonstrates the viability of the polyvalent candidates as global S. pyogenes vaccine candidates. PMID:22265945

  19. Predicted Coverage and Immuno-Safety of a Recombinant C-Repeat Region Based Streptococcus pyogenes Vaccine Candidate.

    PubMed

    McNeilly, Celia; Cosh, Samantha; Vu, Therese; Nichols, Jemma; Henningham, Anna; Hofmann, Andreas; Fane, Anne; Smeesters, Pierre R; Rush, Catherine M; Hafner, Louise M; Ketheesan, Natkuman; Sriprakash, Kadaba S; McMillan, David J

    2016-01-01

    The C-terminal region of the M-protein of Streptococcus pyogenes is a major target for vaccine development. The major feature is the C-repeat region, consisting of 35-42 amino acid repeat units that display high but not perfect identity. SV1 is a S. pyogenes vaccine candidate that incorporates five 14mer amino acid sequences (called J14i variants) from differing C-repeat units in a single recombinant construct. Here we show that the J14i variants chosen for inclusion in SV1 are the most common variants in a dataset of 176 unique M-proteins. Murine antibodies raised against SV1 were shown to bind to each of the J14i variants present in SV1, as well as variants not present in the vaccine. Antibodies raised to the individual J14i variants were also shown to bind to multiple but different combinations of J14i variants, supporting the underlying rationale for the design of SV1. A Lewis Rat Model of valvulitis was then used to assess the capacity of SV1 to induce deleterious immune response associated with rheumatic heart disease. In this model, both SV1 and the M5 positive control protein were immunogenic. Neither of these antibodies were cross-reactive with cardiac myosin or collagen. Splenic T cells from SV1/CFA and SV1/alum immunized rats did not proliferate in response to cardiac myosin or collagen. Subsequent histological examination of heart tissue showed that 4 of 5 mice from the M5/CFA group had valvulitis and inflammatory cell infiltration into valvular tissue, whereas mice immunised with SV1/CFA, SV1/alum showed no sign of valvulitis. These results suggest that SV1 is a safe vaccine candidate that will elicit antibodies that recognise the vast majority of circulating GAS M-types. PMID:27310707

  20. Epidemiological and molecular characteristics of clinical isolates of Streptococcus pyogenes collected between 2005 and 2008 from Chinese children.

    PubMed

    Liang, Yunmei; Liu, Xiaorong; Chang, Hesheng; Ji, Lili; Huang, Guoying; Fu, Zhou; Zheng, Yuejie; Wang, Libo; Li, Chengrong; Shen, Ying; Yu, Sangjie; Yao, Kaihu; Ma, Lin; Shen, Xuzhuang; Yang, Yonghong

    2012-07-01

    The aim of this study was to explore the epidemiological and molecular characteristics of Streptococcus pyogenes in children from different cities in mainland China who were diagnosed with scarlet fever, impetigo and pharyngitis, as well as to detect asymptomatic carriers, between 2005 and 2008, and to compare the results with isolates from rural Chinese children with acute glomerulonephritis in 2005 and in the 1990s. Susceptibility tests to determine MICs and analysis of the presence of erythromycin-resistant genes (mefA, ermB and ermA) and emm gene typing were performed on 466 S. pyogenes isolates from Beijing, Shanghai, Chongqing and Shenzhen. Superantigen genes (speA and speC) were examined by performing PCR on isolates with the most prevalent emm genotype. All isolates were sensitive to penicillin, cefradine and ofloxacin. The highest rate of resistance was against clarithromycin (98.1 %), followed by erythromycin (97.6 %), azithromycin and clindamycin (both 97.2 %), and tetracycline (94.0 %). Among the 466 isolates, 421 (90.3 %) harboured the ermB gene, 145 (31.1 %) were speA-positive and 273 (58.6 %) were speC-positive. The speA gene was common in emm1.0 (88.8 %) and emm6.5 (83.3 %) genotypes. The speC gene was frequently observed in emm4.0 (90.0 %), emm12.0 (69.6 %), emm18.0 (66.7 %), emm22.0 (75.9 %) and emm80.0 (80.0 %) genotypes. The most prevalent emm genotypes in mainland China in recent years were emm1.0 and emm12.0. All isolates remained sensitive to β-lactams and quinolone. PMID:22442290

  1. Predicted Coverage and Immuno-Safety of a Recombinant C-Repeat Region Based Streptococcus pyogenes Vaccine Candidate

    PubMed Central

    McNeilly, Celia; Cosh, Samantha; Vu, Therese; Nichols, Jemma; Henningham, Anna; Hofmann, Andreas; Fane, Anne; Smeesters, Pierre R.; Rush, Catherine M.; Hafner, Louise M.; Ketheesan, Natkuman; Sriprakash, Kadaba S.; McMillan, David J.

    2016-01-01

    The C-terminal region of the M-protein of Streptococcus pyogenes is a major target for vaccine development. The major feature is the C-repeat region, consisting of 35–42 amino acid repeat units that display high but not perfect identity. SV1 is a S. pyogenes vaccine candidate that incorporates five 14mer amino acid sequences (called J14i variants) from differing C-repeat units in a single recombinant construct. Here we show that the J14i variants chosen for inclusion in SV1 are the most common variants in a dataset of 176 unique M-proteins. Murine antibodies raised against SV1 were shown to bind to each of the J14i variants present in SV1, as well as variants not present in the vaccine. Antibodies raised to the individual J14i variants were also shown to bind to multiple but different combinations of J14i variants, supporting the underlying rationale for the design of SV1. A Lewis Rat Model of valvulitis was then used to assess the capacity of SV1 to induce deleterious immune response associated with rheumatic heart disease. In this model, both SV1 and the M5 positive control protein were immunogenic. Neither of these antibodies were cross-reactive with cardiac myosin or collagen. Splenic T cells from SV1/CFA and SV1/alum immunized rats did not proliferate in response to cardiac myosin or collagen. Subsequent histological examination of heart tissue showed that 4 of 5 mice from the M5/CFA group had valvulitis and inflammatory cell infiltration into valvular tissue, whereas mice immunised with SV1/CFA, SV1/alum showed no sign of valvulitis. These results suggest that SV1 is a safe vaccine candidate that will elicit antibodies that recognise the vast majority of circulating GAS M-types. PMID:27310707

  2. Streptococcus pyogenes SpyCEP Influences Host-Pathogen Interactions during Infection in a Murine Air Pouch Model

    PubMed Central

    Chiappini, Nico; Seubert, Anja; Telford, John L.; Grandi, Guido; Serruto, Davide; Margarit, Immaculada; Janulczyk, Robert

    2012-01-01

    Streptococcus pyogenes is a major human pathogen worldwide, responsible for both local and systemic infections. These bacteria express the subtilisin-like protease SpyCEP which cleaves human IL-8 and related chemokines. We show that localization of SpyCEP is growth-phase and strain dependent. Significant shedding was observed only in a strain naturally overexpressing SpyCEP, and shedding was not dependent on SpyCEP autoproteolytic activity. Surface-bound SpyCEP in two different strains was capable of cleaving IL-8. To investigate SpyCEP action in vivo, we adapted the mouse air pouch model of infection for parallel quantification of bacterial growth, host immune cell recruitment and chemokine levels in situ. In response to infection, the predominant cells recruited were neutrophils, monocytes and eosinophils. Concomitantly, the chemokines KC, LIX, and MIP-2 in situ were drastically increased in mice infected with the SpyCEP knockout strain, and growth of this mutant strain was reduced compared to the wild type. SpyCEP has been described as a potential vaccine candidate against S. pyogenes, and we showed that surface-associated SpyCEP was recognized by specific antibodies. In vitro, such antibodies also counteracted the inhibitory effects of SpyCEP on chemokine mediated PMN recruitment. Thus, α-SpyCEP antibodies may benefit the host both directly by enabling opsonophagocytosis, and indirectly, by neutralizing an important virulence factor. The animal model we employed shows promise for broad application in the study of bacterial pathogenesis. PMID:22848376

  3. Virulence factors of Streptococcus pyogenes strains from women in peri-labor with invasive infections.

    PubMed

    Golińska, E; van der Linden, M; Więcek, G; Mikołajczyk, D; Machul, A; Samet, A; Piórkowska, A; Dorycka, M; Heczko, P B; Strus, M

    2016-05-01

    Invasive group A streptococcal (GAS) infections constitute an important epidemiological problem. Many cases occur in women during the postnatal period. The objective of this study was to evaluate the presence of the genes responsible for production of iron-chelating protein (perR) and superantigens (speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ, and ssa) in S. pyogenes strains isolated from invasive infections in women after delivery. Furthermore, this study sought to verify whether S. pyogenes strains show special phenotypic and genotypic (sla, spy1325) characteristics that may play a decisive role in adherence to the genital tract epithelium. Moreover, the emm-types and antibiotic susceptibility were determined. We tested 30 invasive S. pyogenes strains isolated from postpartum invasive infection and 37 GAS control strains isolated from the genital tracts of asymptomatic multiparous women. The majority of the tested strains were shown to express two types of emm genes (1 and 28), though emm -12, -28, -75 and -89 were uniquely expressed in the group of strains isolated from invasive infections. A significantly higher prevalence of perR in the strains from puerperal fever was shown. Significant differences were also found between the two groups with respect to the incidence of the genes related to adherence; GAS strains originating from women with sepsis/puerperal fever showed presence of these genes less frequently than those of the control group. Although differences in frequencies of the gene coding for various superantigens were noted between the compared groups of GAS strains, they were not significant. PMID:26873375

  4. Antimicrobial Susceptibility of Invasive Streptococcus pyogenes Isolates in Germany during 2003-2013

    PubMed Central

    Imöhl, Matthias; van der Linden, Mark

    2015-01-01

    A nationwide laboratory-based surveillance study of invasive S. pyogenes infections was conducted in Germany. Invasive isolates (n = 1,281) were obtained between 2003 and 2013. All isolates were susceptible to penicillin, cefotaxime and vancomycin. Tetracycline showed the highest rate of resistant or intermediate resistant isolates with 9.8%, followed by macrolides (4.0%), trimethoprim/sulfamethoxazole (SXT) (1.9%), levofloxacin (1.3%), chloramphenicol (0.9%) and clindamycin (0.7%). The most prominent trends were the appearance of levofloxacin non-susceptible isolates since 2011, and an increase of SXT non-susceptibility since 2012. PMID:26340445

  5. Antimicrobial Susceptibility of Invasive Streptococcus pyogenes Isolates in Germany during 2003-2013.

    PubMed

    Imöhl, Matthias; van der Linden, Mark

    2015-01-01

    A nationwide laboratory-based surveillance study of invasive S. pyogenes infections was conducted in Germany. Invasive isolates (n = 1,281) were obtained between 2003 and 2013. All isolates were susceptible to penicillin, cefotaxime and vancomycin. Tetracycline showed the highest rate of resistant or intermediate resistant isolates with 9.8%, followed by macrolides (4.0%), trimethoprim/sulfamethoxazole (SXT) (1.9%), levofloxacin (1.3%), chloramphenicol (0.9%) and clindamycin (0.7%). The most prominent trends were the appearance of levofloxacin non-susceptible isolates since 2011, and an increase of SXT non-susceptibility since 2012. PMID:26340445

  6. Constitutive expression of fibronectin binding in Streptococcus pyogenes as a result of anaerobic activation of rofA.

    PubMed Central

    Fogg, G C; Caparon, M G

    1997-01-01

    Protein F is a fibronectin-binding surface protein of Streptococcus pyogenes (group A streptococcus) that mediates adherence to host cells. A gene product encoded by rofA activates transcription of the gene that encodes protein F (prtF) and was identified in a strain of S. pyogenes that expressed high levels of protein F under all conditions tested. Insertional inactivation of rofA in this strain results in a phenotype similar to that of other strains where high-level transcription of prtF occurs only in response to increased oxygen tension. In this study, we have compared the regulation of prtF and rofA in O2-regulated and constitutive strains in order to gain further insight into the function of rofA. Comparison of the prtF and rofA transcripts by S1 nuclease and primer extension assays indicated that the same promoters for each transcript are used in both O2-regulated and constitutive strains. However, analyses of rofA-lacZ reporter alleles revealed that a key difference between strains involves regulation of rofA itself. In O2-regulated strains, expression of rofA was elevated following culture under conditions of reduced O2 tension. However, a much more robust activation of rofA expression was observed when constitutive strains were grown under similar conditions. Exchange of reporter and rofA alleles between strains demonstrated that host genetic background, and not the sequence of the respective rofA allele or regulatory region, dictates the expression phenotype. Activation of rofA required RofA, and RofA was shown to bind specifically to DNA containing the promoters for rofA and prtF. Finally, overexpression of either allele of rofA caused constitutive expression of prtF regardless of host background. These data suggest a model where anaerobic expression of prtF in constitutive hosts is controlled at the level of transcription of rofA and implicate additional factors in this regulatory pathway. PMID:9324268

  7. Transcription of the Streptococcus pyogenes hyaluronic acid capsule biosynthesis operon is regulated by previously unknown upstream elements.

    PubMed

    Falaleeva, Marina; Zurek, Oliwia W; Watkins, Robert L; Reed, Robert W; Ali, Hadeel; Sumby, Paul; Voyich, Jovanka M; Korotkova, Natalia

    2014-12-01

    The important human pathogen Streptococcus pyogenes (group A Streptococcus [GAS]) produces a hyaluronic acid (HA) capsule that plays critical roles in immune evasion. Previous studies showed that the hasABC operon encoding the capsule biosynthesis enzymes is under the control of a single promoter, P1, which is negatively regulated by the two-component regulatory system CovR/S. In this work, we characterize the sequence upstream of P1 and identify a novel regulatory region controlling transcription of the capsule biosynthesis operon in the M1 serotype strain MGAS2221. This region consists of a promoter, P2, which initiates transcription of a novel small RNA, HasS, an intrinsic transcriptional terminator that inefficiently terminates HasS, permitting read-through transcription of hasABC, and a putative promoter which lies upstream of P2. Electrophoretic mobility shift assays, quantitative reverse transcription-PCR, and transcriptional reporter data identified CovR as a negative regulator of P2. We found that the P1 and P2 promoters are completely repressed by CovR, and capsule expression is regulated by the putative promoter upstream of P2. Deletion of hasS or of the terminator eliminates CovR-binding sequences, relieving repression and increasing read-through, hasA transcription, and capsule production. Sequence analysis of 44 GAS genomes revealed a high level of polymorphism in the HasS sequence region. Most of the HasS variations were located in the terminator sequences, suggesting that this region is under strong selective pressure. We discovered that the terminator deletion mutant is highly resistant to neutrophil-mediated killing and is significantly more virulent in a mouse model of GAS invasive disease than the wild-type strain. Together, these results are consistent with the naturally occurring mutations in this region modulating GAS virulence. PMID:25287924

  8. Generation and Surface Localization of Intact M Protein in Streptococcus pyogenes Are Dependent on sagA

    PubMed Central

    Biswas, Indranil; Germon, Pierre; McDade, Kathleen; Scott, June R.

    2001-01-01

    The M protein is an important surface-located virulence factor of Streptococcus pyogenes, the group A streptococcus (GAS). Expression of M protein is primarily controlled by Mga, a transcriptional activator protein. A recent report suggested that the sag locus, which includes nine genes necessary and sufficient for production of streptolysin S, another GAS virulence factor, is also needed for transcription of emm, encoding the M protein (Z. Li, D. D. Sledjeski, B. Kreikemeyer, A. Podbielski, and M. D. Boyle, J. Bacteriol. 181:6019–6027, 1999). To investigate this in more detail, we constructed an insertion-deletion mutation in sagA, the first gene in the sag locus, in the M6 strain JRS4. The resulting strain, JRS470, produced no detectable streptolysin S and showed a drastic reduction in cell surface-associated M protein, as measured by cell aggregation and Western blot analysis. However, transcription of the emm gene was unaffected by the sagA mutation. Detailed analysis with monoclonal antibodies and an antipeptide antibody showed that the M protein in the sagA mutant strain was truncated so that it lacks the C-repeat region and the C-terminal domain required for anchoring it to the cell surface. This truncated M protein was largely found, as expected, in the culture supernatant. Lack of surface-located M protein made the sagA mutant strain susceptible to phagocytosis. Thus, although sagA does not affect transcription of the M6 protein gene, it is needed for the surface localization of this important virulence factor. PMID:11598078

  9. Generation and surface localization of intact M protein in Streptococcus pyogenes are dependent on sagA.

    PubMed

    Biswas, I; Germon, P; McDade, K; Scott, J R

    2001-11-01

    The M protein is an important surface-located virulence factor of Streptococcus pyogenes, the group A streptococcus (GAS). Expression of M protein is primarily controlled by Mga, a transcriptional activator protein. A recent report suggested that the sag locus, which includes nine genes necessary and sufficient for production of streptolysin S, another GAS virulence factor, is also needed for transcription of emm, encoding the M protein (Z. Li, D. D. Sledjeski, B. Kreikemeyer, A. Podbielski, and M. D. Boyle, J. Bacteriol. 181:6019-6027, 1999). To investigate this in more detail, we constructed an insertion-deletion mutation in sagA, the first gene in the sag locus, in the M6 strain JRS4. The resulting strain, JRS470, produced no detectable streptolysin S and showed a drastic reduction in cell surface-associated M protein, as measured by cell aggregation and Western blot analysis. However, transcription of the emm gene was unaffected by the sagA mutation. Detailed analysis with monoclonal antibodies and an antipeptide antibody showed that the M protein in the sagA mutant strain was truncated so that it lacks the C-repeat region and the C-terminal domain required for anchoring it to the cell surface. This truncated M protein was largely found, as expected, in the culture supernatant. Lack of surface-located M protein made the sagA mutant strain susceptible to phagocytosis. Thus, although sagA does not affect transcription of the M6 protein gene, it is needed for the surface localization of this important virulence factor. PMID:11598078

  10. Transcription of the Streptococcus pyogenes Hyaluronic Acid Capsule Biosynthesis Operon Is Regulated by Previously Unknown Upstream Elements

    PubMed Central

    Falaleeva, Marina; Zurek, Oliwia W.; Watkins, Robert L.; Reed, Robert W.; Ali, Hadeel; Sumby, Paul; Voyich, Jovanka M.

    2014-01-01

    The important human pathogen Streptococcus pyogenes (group A Streptococcus [GAS]) produces a hyaluronic acid (HA) capsule that plays critical roles in immune evasion. Previous studies showed that the hasABC operon encoding the capsule biosynthesis enzymes is under the control of a single promoter, P1, which is negatively regulated by the two-component regulatory system CovR/S. In this work, we characterize the sequence upstream of P1 and identify a novel regulatory region controlling transcription of the capsule biosynthesis operon in the M1 serotype strain MGAS2221. This region consists of a promoter, P2, which initiates transcription of a novel small RNA, HasS, an intrinsic transcriptional terminator that inefficiently terminates HasS, permitting read-through transcription of hasABC, and a putative promoter which lies upstream of P2. Electrophoretic mobility shift assays, quantitative reverse transcription-PCR, and transcriptional reporter data identified CovR as a negative regulator of P2. We found that the P1 and P2 promoters are completely repressed by CovR, and capsule expression is regulated by the putative promoter upstream of P2. Deletion of hasS or of the terminator eliminates CovR-binding sequences, relieving repression and increasing read-through, hasA transcription, and capsule production. Sequence analysis of 44 GAS genomes revealed a high level of polymorphism in the HasS sequence region. Most of the HasS variations were located in the terminator sequences, suggesting that this region is under strong selective pressure. We discovered that the terminator deletion mutant is highly resistant to neutrophil-mediated killing and is significantly more virulent in a mouse model of GAS invasive disease than the wild-type strain. Together, these results are consistent with the naturally occurring mutations in this region modulating GAS virulence. PMID:25287924

  11. Isolation and characterization of a Streptococcus pyogenes protein that binds to basal laminae of human cardiac muscle.

    PubMed Central

    Winters, B D; Ramasubbu, N; Stinson, M W

    1993-01-01

    A 9-kDa glycosaminoglycan-binding protein (GAG-BP) was isolated from Streptococcus pyogenes and purified to homogeneity by affinity chromatography on heparin-agarose. The protein selectively bound to the basal laminae of human cardiac muscle and had an apparent dissociation constant of 2.5 x 10(-7) M. Chemical analyses indicated that the GAG-BP was rich in alanine, lysine, and arginine (pI 9.5) and devoid of tyrosine, methionine, histidine, and half-cystine. There were no detectable carbohydrate or phosphate substituents. The amino acid sequence of the N terminus of GAG-BP showed homology with those of histone-like DNA-binding proteins of several other bacteria. Circular dichroism spectroscopy indicated that the protein was made up of 50% beta-sheet and 50% beta-turn and random coil in aqueous solution; however, when the protein complexed with heparin, it adopted a more ordered structure containing 25% alpha-helix, 50% beta-sheet, and 25% beta-turn and random coil. The GAG-BP cross-reacted serologically with a component of similar size in extracts of other group A streptococci and was present in the culture medium during late logarithmic growth. Images PMID:8335359

  12. Emergence of scarlet fever Streptococcus pyogenes emm12 clones in Hong Kong is associated with toxin acquisition and multidrug resistance.

    PubMed

    Davies, Mark R; Holden, Matthew T; Coupland, Paul; Chen, Jonathan H K; Venturini, Carola; Barnett, Timothy C; Zakour, Nouri L Ben; Tse, Herman; Dougan, Gordon; Yuen, Kwok-Yung; Walker, Mark J

    2015-01-01

    A scarlet fever outbreak began in mainland China and Hong Kong in 2011 (refs. 1-6). Macrolide- and tetracycline-resistant Streptococcus pyogenes emm12 isolates represent the majority of clinical cases. Recently, we identified two mobile genetic elements that were closely associated with emm12 outbreak isolates: the integrative and conjugative element ICE-emm12, encoding genes for tetracycline and macrolide resistance, and prophage ΦHKU.vir, encoding the superantigens SSA and SpeC, as well as the DNase Spd1 (ref. 4). Here we sequenced the genomes of 141 emm12 isolates, including 132 isolated in Hong Kong between 2005 and 2011. We found that the introduction of several ICE-emm12 variants, ΦHKU.vir and a new prophage, ΦHKU.ssa, occurred in three distinct emm12 lineages late in the twentieth century. Acquisition of ssa and transposable elements encoding multidrug resistance genes triggered the expansion of scarlet fever-associated emm12 lineages in Hong Kong. The occurrence of multidrug-resistant ssa-harboring scarlet fever strains should prompt heightened surveillance within China and abroad for the dissemination of these mobile genetic elements. PMID:25401300

  13. Life in protein-rich environments: the relA-independent response of Streptococcus pyogenes to amino acid starvation.

    PubMed

    Steiner, K; Malke, H

    2000-12-01

    Considering that group A streptococci are multiple auxotrophs that may encounter shortage of amino acids during specific stages of the infectious process, we studied their adaptive response to amino acid deprivation. We found that, in addition to the (p)ppGpp-mediated stringent response characterized previously, Streptococcus pyogenes exhibits a relA-independent response comprising transcriptional modulation of a specific subset of genes involved in pathogenesis. Genes/operons transcriptionally upregulated during starvation of both wild type and relA mutants included the two-component signal transduction system covRS, the positive regulator (ropB) of the pyrogenic exotoxin B gene, speB, the oligopeptide (opp) and dipeptide (dpp) permease systems and the pepB gene putatively involved in the intracellular processing of oligopeptides. Upregulation of covRS was accompanied by downregulation of ska, one of the target genes of the negative CovR regulator, and the net effect of amino acid starvation also favoured repression of speB. A significant feature of upregulated opp expression was stimulated readthrough transcription of the operon-internal oppA terminator, leading to increased mRNA levels for synthesis of the translocator complex relative to the substrate-binding protein. Based on these and previous results, a stimulus-response network is proposed that counteracts the stringent response and may enable the pathogen to mount a dynamic response to the protein-rich environment provided by its human host. PMID:11123674

  14. Description of the Pathogenic Features of Streptococcus pyogenes Isolates from Invasive and Non-Invasive Diseases in Aichi, Japan.

    PubMed

    Matsumoto, Masakado; Yamada, Kazuhiro; Suzuki, Masahiro; Adachi, Hirokazu; Kobayashi, Shinichi; Yamashita, Teruo; Minagawa, Hiroko; Tatsuno, Ichiro; Hasegawa, Tadao

    2016-07-22

    We identified hypervirulent Streptococcus pyogenes in 27 and 420 isolates from patients with invasive and non-invasive diseases, respectively, in Aichi Prefecture, Japan, between 2003 and 2012, in an attempt to understand why the prevalence of streptococcal toxic shock syndrome (STSS) suddenly increased in this location during 2011. Hypervirulent strains belong to the emm1 genotype, with a mutation in the covR/S genes that regulate many other genes, encoding virulence determinants and resulting in the absence of the proteinase streptococcal exotoxin B and the production of virulence factors such as the superantigen streptococcal exotoxin A, the nuclease streptococcal DNase, the cytotoxin NAD-glycohydrolase, and the hemolysin streptolysin O. We found 1 strain from invasive disease and 1 from non-invasive disease with traits similar to those of hypervirulent strains, except that the sda1 gene was absent. We also found 1 non-emm1 strain with phenotypic and genetic traits identical to those of the emm1 hypervirulent strains except that it did not belong to emm1 genotype, from non-invasive diseases cases in 2011. These findings suggested that hypervirulent and hypervirulent-like strains from invasive and non-invasive disease cases could have at least partially contributed to the sudden increase in the number of patients with STSS in Aichi during 2011. PMID:26567838

  15. [Regulation of endothelial cells functions by ultrasonic supernatant of Streptococcus pyogenes].

    PubMed

    Starikova, É A; Lebedeva, A M; Burova, L A; Freĭdlin, I S

    2012-01-01

    Angiogenesis and vascular remodeling are vital components of inflammation. As an inflammation evolves, vessels expand to supply nutrients and inflammatory mediators, sustaining the accumulation of activated immune cells in the affected tissues. This study demonstrates that ultrasonic supernatant of Streptoccocus pyogenes has anti-angiogenic properties: inhibit EA.hy 926 human endothelial cells metabolism, adhesion, migration, proliferation. At the same time Streptococcal components inhibit signaling pathways that involve FAK and ERK1/2. These effects are not associated with necrosis or apoptosis in cell culture. Taking together, our results suggest that impairing angiogenic function of endothelial cells might contribute to the reduced tissue perfusion, hypoxia, and subsequent regional tissue necrosis caused by Streptococci group A. PMID:22567900

  16. Serotype- and strain- dependent contribution of the sensor kinase CovS of the CovRS two-component system to Streptococcus pyogenes pathogenesis

    PubMed Central

    2010-01-01

    Background The Streptococcus pyogenes (group A streptococci, GAS) two-component signal transduction system CovRS has been described to be important for pathogenesis of this exclusively human bacterial species. If this system acts uniquely in all serotypes is currently unclear. Presence of serotype- or strain-dependent regulatory circuits and polarity is an emerging scheme in Streptococcus pyogenes pathogenesis. Thus, the contribution of the sensor kinase (CovS) of the global regulatory two-component signal transduction system CovRS on pathogenesis of several M serotypes was investigated. Results CovS mutation uniformly repressed capsule expression and hampered keratinocyte adherence in all tested serotypes. However, a serotype- and even strain-dependent contribution on survival in whole human blood and biofilm formation was noted, respectively. Conclusions These data provide new information on the action of the CovS sensor kinase and revealed that its activity on capsule expression and keratinocyte adherence is uniform across serotypes, whereas the influence on biofilm formation and blood survival is serotype or even strain dependent. This adds the CovRS system to a growing list of serotype-specific acting regulatory loci in S. pyogenes. PMID:20113532

  17. Inactivation of the CovR/S virulence regulator impairs infection in an improved murine model of Streptococcus pyogenes naso-pharyngeal infection.

    PubMed

    Alam, Faraz M; Turner, Claire E; Smith, Ken; Wiles, Siouxsie; Sriskandan, Shiranee

    2013-01-01

    Streptococcus pyogenes is a leading cause of pharyngeal infection, with an estimated 616 million cases per year. The human nasopharynx represents the major reservoir for all S. pyogenes infection, including severe invasive disease. To investigate bacterial and host factors that influence S. pyogenes infection, we have devised an improved murine model of nasopharyngeal colonization, with an optimized dosing volume to avoid fulminant infections and a sensitive host strain. In addition we have utilized a refined technique for longitudinal monitoring of bacterial burden that is non-invasive thereby reducing the numbers of animals required. The model was used to demonstrate that the two component regulatory system, CovR/S, is required for optimum infection and transmission from the nasopharynx. There is a fitness cost conferred by covR/S mutation that is specific to the nasopharynx. This may explain why S. pyogenes with altered covR/S have not become prevalent in community infections despite possessing a selective advantage in invasive infection. PMID:23637876

  18. Inactivation of the CovR/S Virulence Regulator Impairs Infection in an Improved Murine Model of Streptococcus pyogenes Naso-Pharyngeal Infection

    PubMed Central

    Alam, Faraz M.; Turner, Claire E.; Smith, Ken; Wiles, Siouxsie; Sriskandan, Shiranee

    2013-01-01

    Streptococcus pyogenes is a leading cause of pharyngeal infection, with an estimated 616 million cases per year. The human nasopharynx represents the major reservoir for all S. pyogenes infection, including severe invasive disease. To investigate bacterial and host factors that influence S. pyogenes infection, we have devised an improved murine model of nasopharyngeal colonization, with an optimized dosing volume to avoid fulminant infections and a sensitive host strain. In addition we have utilized a refined technique for longitudinal monitoring of bacterial burden that is non-invasive thereby reducing the numbers of animals required. The model was used to demonstrate that the two component regulatory system, CovR/S, is required for optimum infection and transmission from the nasopharynx. There is a fitness cost conferred by covR/S mutation that is specific to the nasopharynx. This may explain why S. pyogenes with altered covR/S have not become prevalent in community infections despite possessing a selective advantage in invasive infection. PMID:23637876

  19. Use of surface-enhanced laser desorption ionization protein chip system to analyze streptococcal exotoxin B activity secreted by Streptococcus pyogenes.

    PubMed

    Boyle, M D; Romer, T G; Meeker, A K; Sledjeski, D D

    2001-08-01

    Ciphergen surface-enhanced laser desorption ionization (SELDI) protein chip technology was used to analyze the secretion and autoactivation of the Streptococcus pyogenes cysteine protease SpeB. This method allowed rapid identification of both the zymogen form of the protein Mr approximately 41,000 and the fully active enzyme Mr approximately 28,500. SpeB production in culture supernatants was demonstrated to be growth-phase regulated and SpeB positive and negative variants of a blood passaged S. pyogenes isolate could readily be distinguished. In kinetic studies of the autoactivation of the zymogen form of SpeB, the sequential generation of four intermediates was detected before the accumulation of the fully active enzyme. The methods described enabled enhanced speed, use of lower sample volumes and concentrations, and a more complete molecular characterization of SpeB than allowed by existing methods of analysis using SDS-PAGE and Western immunoblotting. PMID:11412919

  20. Severe Soft Tissue Infection Caused by a Non-Beta-Hemolytic Streptococcus pyogenes Strain Harboring a Premature Stop Mutation in the sagC Gene

    PubMed Central

    Gerlach, Roman G.; Ensser, Armin; Dahesh, Samira; Popp, Isabel; Heeg, Christiane; Bleiziffer, Oliver; Merz, Thomas; Schulz, Theresia; Horch, Raymund E.; Bogdan, Christian; Nizet, Victor; van der Linden, Mark

    2013-01-01

    We recovered a non-beta-hemolytic Streptococcus pyogenes strain from a severe soft tissue infection. In this isolate, we detected a premature stop codon within the sagC gene of the streptolysin S (SLS) biosynthetic operon. Reintroduction of full-length sagC gene on a plasmid vector restored the beta-hemolytic phenotype to our clinical isolate, indicating that the point mutation in sagC accounted for loss of hemolytic activity. To the best of our knowledge, this is the first report to demonstrate that a severe soft tissue infection can be caused by a non-beta-hemolytic S. pyogenes strain lacking a functional SagC. PMID:23515542

  1. Structure and Interactions of a Dimeric Variant of sHIP, a Novel Virulence Determinant of Streptococcus pyogenes

    PubMed Central

    Diehl, Carl; Wisniewska, Magdalena; Frick, Inga-Maria; Streicher, Werner; Björck, Lars; Malmström, Johan; Wikström, Mats

    2016-01-01

    Streptococcus pyogenes is one of the most significant bacterial pathogens in the human population mostly causing superficial and uncomplicated infections (pharyngitis and impetigo) but also invasive and life-threatening disease. We have previously identified a virulence determinant, protein sHIP, which is secreted at higher levels by an invasive compared to a non-invasive strain of S. pyogenes. The present work presents a further characterization of the structural and functional properties of this bacterial protein. Biophysical and structural studies have shown that protein sHIP forms stable tetramers both in the crystal and in solution. The tetramers are composed of four helix-loop-helix motifs with the loop regions connecting the helices displaying a high degree of flexibility. Owing to interactions at the tetramer interface, the observed tetramer can be described as a dimer of dimers. We identified three residues at the tetramer interface (Leu84, Leu88, Tyr95), which due to largely non-polar side-chains, could be important determinants for protein oligomerization. Based on these observations, we produced a sHIP variant in which these residues were mutated to alanines. Biophysical experiments clearly indicated that the sHIP mutant appear only as dimers in solution confirming the importance of the interfacial residues for protein oligomerisation. Furthermore, we could show that the sHIP mutant interacts with intact histidine-rich glycoprotein (HRG) and the histidine-rich repeats in HRG, and inhibits their antibacterial activity to the same or even higher extent as compared to the wild type protein sHIP. We determined the crystal structure of the sHIP mutant, which, as a result of the high quality of the data, allowed us to improve the existing structural model of the protein. Finally, by employing NMR spectroscopy in solution, we generated a model for the complex between the sHIP mutant and an HRG-derived heparin-binding peptide, providing further molecular

  2. Structure and Interactions of a Dimeric Variant of sHIP, a Novel Virulence Determinant of Streptococcus pyogenes.

    PubMed

    Diehl, Carl; Wisniewska, Magdalena; Frick, Inga-Maria; Streicher, Werner; Björck, Lars; Malmström, Johan; Wikström, Mats

    2016-01-01

    Streptococcus pyogenes is one of the most significant bacterial pathogens in the human population mostly causing superficial and uncomplicated infections (pharyngitis and impetigo) but also invasive and life-threatening disease. We have previously identified a virulence determinant, protein sHIP, which is secreted at higher levels by an invasive compared to a non-invasive strain of S. pyogenes. The present work presents a further characterization of the structural and functional properties of this bacterial protein. Biophysical and structural studies have shown that protein sHIP forms stable tetramers both in the crystal and in solution. The tetramers are composed of four helix-loop-helix motifs with the loop regions connecting the helices displaying a high degree of flexibility. Owing to interactions at the tetramer interface, the observed tetramer can be described as a dimer of dimers. We identified three residues at the tetramer interface (Leu84, Leu88, Tyr95), which due to largely non-polar side-chains, could be important determinants for protein oligomerization. Based on these observations, we produced a sHIP variant in which these residues were mutated to alanines. Biophysical experiments clearly indicated that the sHIP mutant appear only as dimers in solution confirming the importance of the interfacial residues for protein oligomerisation. Furthermore, we could show that the sHIP mutant interacts with intact histidine-rich glycoprotein (HRG) and the histidine-rich repeats in HRG, and inhibits their antibacterial activity to the same or even higher extent as compared to the wild type protein sHIP. We determined the crystal structure of the sHIP mutant, which, as a result of the high quality of the data, allowed us to improve the existing structural model of the protein. Finally, by employing NMR spectroscopy in solution, we generated a model for the complex between the sHIP mutant and an HRG-derived heparin-binding peptide, providing further molecular

  3. Conserved DegP Protease in Gram-Positive Bacteria Is Essential for Thermal and Oxidative Tolerance and Full Virulence in Streptococcus pyogenes

    PubMed Central

    Jones, C. Hal; Bolken, Tove' C.; Jones, Kevin F.; Zeller, Gloria O.; Hruby, Dennis E.

    2001-01-01

    The DegP protease, a multifunctional chaperone and protease, has been shown to be essential for virulence in gram-negative pathogens such as Salmonella enterica serovar Typhimurium, Brucella abortus, Yersinia enterocolitica, and Pseudomonas aeruginosa. The function of DegP in pathogenesis appears to be the degradation of damaged proteins that accumulate as a result of the initial host response to infection, which includes the release of reactive oxygen intermediates. Additionally, the DegP protease plays a major role in monitoring and maintaining the Escherichia coli periplasm and influences E. coli pilus biogenesis. We report here the identification of highly homologous enzymes in Streptococcus pyogenes, Streptococcus gordonii, Streptococcus mutans, Staphylococcus aureus, and Enterococcus faecalis. Moreover, the phenotype of an insertionally inactivated degP allele in S. pyogenes is similar to that reported for E. coli, with temperature sensitivity for growth and enhanced sensitivity to reactive oxygen intermediates. Virulence studies in a mouse model of streptococcal infection indicate that a functional DegP protease is required for full virulence. These results suggest DegP as an attractive broad-spectrum target for future anti-infective drug development. PMID:11500427

  4. Incidence and characterization of beta-hemolytic Streptococcus milleri and differentiation from S. pyogenes (group A), S. equisimilis (group C), and large-colony group G streptococci.

    PubMed

    Lawrence, J; Yajko, D M; Hadley, W K

    1985-11-01

    The biochemical characteristics of 172 clinical isolates of group A, C, F, or G or "nongroupable" beta-hemolytic streptococci were examined. Among these isolates, 91 were identified as beta-hemolytic strains of Streptococcus milleri. The remaining isolates included 20 Streptococcus pyogenes, 21 Streptococcus equisimilis, 37 large-colony group G streptococci, and 3 unidentified nongroupable isolates. A majority (84%) of the S. milleri strains possessed Lancefield group antigen (3 A, 27 C, 41 F, and 5 G), whereas 15 S. milleri strains (16%) were nongroupable. Serological tests did not differentiate S. milleri isolates with group A, C, or G antigen from S. pyogenes (group A), S. equisimilis (group C), or large-colony group G streptococci. Biochemical tests which were found useful for differentiation included the Voges-Proskauer test, hydrolysis of pyroglutamic acid and beta-D-glucuronide, bacitracin susceptibility, and acid production from ribose. S. milleri represented 56% of the group C, 100% of the group F, and 83% of the nongroupable beta-hemolytic streptococci isolated in our clinical laboratory, whereas the incidence of S. milleri among group A and group G streptococci was estimated to be low. The role of beta-hemolytic S. milleri as a cause of human infection remains obscured by the failure to routinely differentiate S. milleri from other beta-hemolytic streptococci. PMID:3902878

  5. Engineering multiple biological functional motifs into a blank collagen-like protein template from Streptococcus pyogenes.

    PubMed

    Peng, Yong Y; Stoichevska, Violet; Schacht, Kristin; Werkmeister, Jerome A; Ramshaw, John A M

    2014-07-01

    Bacterially derived triple-helical, collagen-like proteins are attractive as potential biomedical materials. The collagen-like domain of the Scl2 protein from S. pyogenes lacks any specific binding sites for mammalian cells yet possesses the inherent structural integrity of the collagen triple-helix of animal collagens. It can, therefore, be considered as a structurally-stable "blank slate" into which various defined, biological sequences, derived from animal collagens, can be added by substitutions or insertions, to enable production of novel designed materials to fit specific functional requirements. In the present study, we have used site directed mutagenesis to substitute two functional sequences, one for heparin binding and the other for integrin binding, into different locations in the triple-helical structure. This provided three new constructs, two containing the single substitutions and one containing both substitutions. The stability of these constructs was marginally reduced when compared to the unmodified sequence. When compared to the unmodified bacterial collagen, both the modified collagens that contain the heparin binding site showed marked binding of fluorescently labeled heparin. Similarly, the modified collagens from both constructs containing the integrin binding site showed significant adhesion of L929 cells that are known to possess the appropriate integrin receptor. C2C12 cells that lack any appropriate integrins did not bind. These data show that bacterial collagen-like sequences can be modified to act like natural extracellular matrix collagens by inserting one or more unique biological domains with defined function. PMID:23913780

  6. Rapid increase of resistance to erythromycin and clindamycin in Streptococcus pyogenes in Italy, 1993-1995. The Italian Surveillance Group for Antimicrobial Resistance.

    PubMed Central

    Cornaglia, G.; Ligozzi, M.; Mazzariol, A.; Valentini, M.; Orefici, G.; Fontana, R.

    1996-01-01

    A survey of antibiotic resistance in Streptococcus pyogenes in Italy showed a sharp increase in erythromycin resistance. In 1993, the incidence of erythromycin-resistant strains was on average 5.1%, with marked variations by geographic area. Two years later, the incidence of these strains had registered a 1.5- to roughly 20-fold increase, with a mean value of 25.9%, exceeding 40% in three centers out of 13 and 30% in another four. For all the strains studied, normal levels of susceptibility to penicillin were reported. PMID:9011381

  7. CovS inactivates CovR and is required for growth under conditions of general stress in Streptococcus pyogenes.

    PubMed

    Dalton, Tracy L; Scott, June R

    2004-06-01

    The gram-positive human pathogen Streptococcus pyogenes (group A streptococcus [GAS]) causes diseases ranging from mild and often self-limiting infections of the skin or throat to invasive and life-threatening illnesses. To cause such diverse types of disease, the GAS must be able to sense adverse environments and regulate its gene expression accordingly. The CovR/S two-component signal transduction regulatory system in GAS represses about 15% of the GAS genome, including many genes involved in virulence, in response to the environment. We report that CovR is still able to repress transcription from several promoters in the absence of the putative histidine kinase sensor for this system, CovS. We also show that a phosphorylation site mutant (D53A) of CovR is unable to repress gene expression. In addition, we report that a strain with a nonpolar mutation in CovS does not grow at a low pH, elevated temperature, or high osmolarity. The stress-related phenotypes of the CovS mutant were complemented by expression of covS from a plasmid. Selection for growth of a CovS mutant under stress conditions resulted in isolation of second-site mutations that inactivated covR, indicating that CovR and CovS act in the same pathway. Also, at 40 degrees C in the wild-type strain, CovR appeared to be less active on the promoter tested, which is consistent with the hypothesis that it was partially inactivated by CovS. We suggest that under mild stress conditions, CovS inactivates CovR, either directly or indirectly, and that this inactivation relieves repression of many GAS genes, including the genes needed for growth of GAS under stress conditions and some genes that are necessary for virulence. Growth of many gram-positive bacteria under multiple-stress conditions requires alteration of promoter recognition produced by RNA polymerase association with the general stress response sigma factor, sigma(B). We provide evidence that for GAS, which lacks a sigB ortholog, growth under stress

  8. CovS Inactivates CovR and Is Required for Growth under Conditions of General Stress in Streptococcus pyogenes

    PubMed Central

    Dalton, Tracy L.; Scott, June R.

    2004-01-01

    The gram-positive human pathogen Streptococcus pyogenes (group A streptococcus [GAS]) causes diseases ranging from mild and often self-limiting infections of the skin or throat to invasive and life-threatening illnesses. To cause such diverse types of disease, the GAS must be able to sense adverse environments and regulate its gene expression accordingly. The CovR/S two-component signal transduction regulatory system in GAS represses about 15% of the GAS genome, including many genes involved in virulence, in response to the environment. We report that CovR is still able to repress transcription from several promoters in the absence of the putative histidine kinase sensor for this system, CovS. We also show that a phosphorylation site mutant (D53A) of CovR is unable to repress gene expression. In addition, we report that a strain with a nonpolar mutation in CovS does not grow at a low pH, elevated temperature, or high osmolarity. The stress-related phenotypes of the CovS mutant were complemented by expression of covS from a plasmid. Selection for growth of a CovS mutant under stress conditions resulted in isolation of second-site mutations that inactivated covR, indicating that CovR and CovS act in the same pathway. Also, at 40°C in the wild-type strain, CovR appeared to be less active on the promoter tested, which is consistent with the hypothesis that it was partially inactivated by CovS. We suggest that under mild stress conditions, CovS inactivates CovR, either directly or indirectly, and that this inactivation relieves repression of many GAS genes, including the genes needed for growth of GAS under stress conditions and some genes that are necessary for virulence. Growth of many gram-positive bacteria under multiple-stress conditions requires alteration of promoter recognition produced by RNA polymerase association with the general stress response sigma factor, σB. We provide evidence that for GAS, which lacks a sigB ortholog, growth under stress conditions

  9. Nucleotides critical for the interaction of the Streptococcus pyogenes Mga virulence regulator with Mga-regulated promoter sequences.

    PubMed

    Hause, Lara L; McIver, Kevin S

    2012-09-01

    The Mga regulator of Streptococcus pyogenes directly activates the transcription of a core regulon that encodes virulence factors such as M protein (emm), C5a peptidase (scpA), and streptococcal inhibitor of complement (sic) by directly binding to a 45-bp binding site as determined by an electrophoretic mobility shift assay (EMSA) and DNase I protection. However, by comparing the nucleotide sequences of all established Mga binding sites, we found that they exhibit only 13.4% identity with no discernible symmetry. To determine the core nucleotides involved in functional Mga-DNA interactions, the M1T1 Pemm1 binding site was altered and screened for nucleotides important for DNA binding in vitro and for transcriptional activation using a plasmid-based luciferase reporter in vivo. Following this analysis, 34 nucleotides within the Pemm1 binding site that had an effect on Mga binding, Mga-dependent transcriptional activation, or both were identified. Of these critical nucleotides, guanines and cytosines within the major groove were disproportionately identified clustered at the 5' and 3' ends of the binding site and with runs of nonessential adenines between the critical nucleotides. On the basis of these results, a Pemm1 minimal binding site of 35 bp bound Mga at a level comparable to the level of binding of the larger 45-bp site. Comparison of Pemm with directed mutagenesis performed in the M1T1 Mga-regulated PscpA and Psic promoters, as well as methylation interference analysis of PscpA, establish that Mga binds to DNA in a promoter-specific manner. PMID:22773785

  10. Structural Analysis of Streptococcus pyogenes NADH Oxidase: Conformational Dynamics Involved in Formation of the C(4a)-Peroxyflavin Intermediate.

    PubMed

    Wallen, Jamie R; Mallett, T Conn; Okuno, Takashi; Parsonage, Derek; Sakai, Hiroaki; Tsukihara, Tomitake; Claiborne, Al

    2015-11-17

    In probing the oxygen reactivity of an Enterococcus faecalis NADH oxidase (Nox; O2 → 2H2O) C42S mutant lacking the Cys42-sulfenic acid (Cys42-SOH) redox center, we provided direct evidence of a C(4a)-peroxyflavin intermediate in the oxidative half-reaction and also described a conformational or chemical change that is rate-limiting for full reoxidation of the homodimer. In this work, the Nox from Streptococcus pyogenes (SpyNox) has been expressed and crystallized, and the overoxidized wild-type [Cys44-SOH → Cys44-sulfinic acid (Cys44-SO2H)] and C44S mutant enzyme structures have been refined at 2.0 and 2.15 Å, respectively. We show that azide binds to the two-electron reduced wild-type (EH2) enzyme and to the mutant enzyme in solution, but with a significantly higher affinity for the mutant protein. The spectral course of the titration with the SpyNox EH2 form clearly indicates progressive displacement of the Cys44-S(-) → FAD charge-transfer interaction. An azide soak with C44S Nox crystals led to the structure of the complex, as refined at 2.10 Å. The active-site N3(-) ligand is proximal to the Ser44 and His11 side chains, and a significant shift in the Ser44 side chain also appears. This provides an attractive explanation for the azide-induced loss of charge-transfer absorbance seen with the wild-type EH2 form and also permits accommodation of a C(4a)-peroxyflavin structural model. The conformation of Ser44 and the associated helical element, and the resulting steric accommodation, appear to be linked to the conformational change described in the E. faecalis C42S Nox oxidative half-reaction. PMID:26506002

  11. The neural and vascular effects of killed Su-Streptococcus pyogenes (OK-432) in preterm fetal sheep

    PubMed Central

    Cowie, R. V.; Stone, P. R.; Barrett, R.; Naylor, A. S.; Blood, A. B.; Gunn, A. J.

    2010-01-01

    Fetal exposure to inflammatory mediators is associated with a greater risk of brain injury and may cause endothelial dysfunction; however, nearly all the evidence is derived from gram-negative bacteria. Intrapleural injections of OK-432, a killed Su-strain of Streptococcus pyogenes, has been used to treat fetal chylothorax. In this study, we evaluated the neural and cardiovascular effects of OK-432 in preterm fetal sheep (104 ± 1 days, term 147 days). OK-432 (0.1 mg, n = 6) or saline vehicle (n = 7) was infused in the fetal pleura, and fetuses were monitored for 7 days. Blood samples were taken routinely for plasma nitrite measurement. Fetal brains were taken for histological assessment at the end of the experiment. Between 3 and 7 h postinjection, OK-432 administration was associated with transient suppression of fetal body and breathing movements and electtroencephalogram activity (P < 0.05), increased carotid and femoral vascular resistance (P < 0.05), but no change in blood pressure. Brain activity and behavior then returned to normal except in one fetus that developed seizures. OK-432 fetuses showed progressive, sustained vasodilatation (P < 0.05), with lower blood pressure after 4 days (P < 0.05), but normal heart rate. There were no changes in plasma nitrite levels. Histological studies showed bilateral infarction in the dorsal limb of the hippocampus of the fetus that developed seizures, but no injury in other fetuses. We conclude that a single low-dose injection of OK-432 can be associated with risk of focal cerebral injury in the preterm fetus and chronic central and peripheral vasodilatation that does not appear to be mediated by nitric oxide. PMID:20484698

  12. Unique Genomic Arrangements in an Invasive Serotype M23 Strain of Streptococcus pyogenes Identify Genes That Induce Hypervirulence

    PubMed Central

    Bao, Yunjuan; Liang, Zhong; Booyjzsen, Claire; Mayfield, Jeffrey A.; Li, Yang; Lee, Shaun W.; Ploplis, Victoria A.; Song, Hui

    2014-01-01

    The first genome sequence of a group A Streptococcus pyogenes serotype M23 (emm23) strain (M23ND), isolated from an invasive human infection, has been completed. The genome of this opacity factor-negative (SOF−) strain is composed of a circular chromosome of 1,846,477 bp. Gene profiling showed that this strain contained six phage-encoded and 24 chromosomally inherited well-known virulence factors, as well as 11 pseudogenes. The bacterium has acquired four large prophage elements, ΦM23ND.1 to ΦM23ND.4, harboring genes encoding streptococcal superantigen (ssa), streptococcal pyrogenic exotoxins (speC, speH, and speI), and DNases (spd1 and spd3), with phage integrase genes being present at one flank of each phage insertion, suggesting that the phages were integrated by horizontal gene transfer. Comparative analyses revealed unique large-scale genomic rearrangements that result in genomic rearrangements that differ from those of previously sequenced GAS strains. These rearrangements resulted in an imbalanced genomic architecture and translocations of chromosomal virulence genes. The covS sensor in M23ND was identified as a pseudogene, resulting in the attenuation of speB function and increased expression of the genes for the chromosomal virulence factors multiple-gene activator (mga), M protein (emm23), C5a peptidase (scpA), fibronectin-binding proteins (sfbI and fbp54), streptolysin O (slo), hyaluronic acid capsule (hasA), streptokinase (ska), and DNases (spd and spd3), which were verified by PCR. These genes are responsible for facilitating host epithelial cell binding and and/or immune evasion, thus further contributing to the virulence of M23ND. In conclusion, strain M23ND has become highly pathogenic as the result of a combination of multiple genetic factors, particularly gene composition and mutations, prophage integrations, unique genomic rearrangements, and regulated expression of critical virulence factors. PMID:25225265

  13. Heme-bound SiaA from Streptococcus pyogenes: Effects of mutations and oxidation state on protein stability.

    PubMed

    Akbas, Neval; Draganova, Elizabeth B; Block, Darci R; Sook, Brian R; Chan, Yau Fong; Zhuo, Joy; Eichenbaum, Zehava; Rodgers, Kenton R; Dixon, Dabney W

    2016-05-01

    The protein SiaA (HtsA) is part of a heme uptake pathway in Streptococcus pyogenes. In this report, we present the heme binding of the alanine mutants of the axial histidine (H229A) and methionine (M79A) ligands, as well as a lysine (K61A) and cysteine (C58A) located near the heme propionates (based on homology modeling) and a control mutant (C47A). pH titrations gave pKa values ranging from 9.0 to 9.5, close to the value of 9.7 for WT SiaA. Resonance Raman spectra of the mutants suggested that the ferric heme environment may be distinct from the wild-type; spectra of the ferrous states were similar. The midpoint reduction potential of the K61A mutant was determined by spectroelectrochemical titration to be 61±3mV vs. SHE, similar to the wild-type protein (68±3mV). The addition of guanidine hydrochloride showed two processes for protein denaturation, consistent with heme loss from protein forms differing by the orientation of the heme in the binding pocket (the half-life for the slower process ranged from less than half a day to two days). The ease of protein unfolding was related to the strength of interaction of the residues with the heme. We hypothesize that kinetically facile but only partial unfolding, followed by a very slow approach to the completely unfolded state, may be a fundamental attribute of heme trafficking proteins. Small motions to release/transfer the heme accompanied by resistance to extensive unfolding may preserve the three dimensional form of the protein for further uptake and release. PMID:26746808

  14. Crystal structure of Streptococcus pyogenes EndoS, an immunomodulatory endoglycosidase specific for human IgG antibodies

    PubMed Central

    Trastoy, Beatriz; Lomino, Joseph V.; Pierce, Brian G.; Carter, Lester G.; Günther, Sebastian; Giddens, John P.; Snyder, Greg A.; Weiss, Thomas M.; Weng, Zhiping; Wang, Lai-Xi; Sundberg, Eric J.

    2014-01-01

    To evade host immune mechanisms, many bacteria secrete immunomodulatory enzymes. Streptococcus pyogenes, one of the most common human pathogens, secretes a large endoglycosidase, EndoS, which removes carbohydrates in a highly specific manner from IgG antibodies. This modification renders antibodies incapable of eliciting host effector functions through either complement or Fc γ receptors, providing the bacteria with a survival advantage. On account of this antibody-specific modifying activity, EndoS is being developed as a promising injectable therapeutic for autoimmune diseases that rely on autoantibodies. Additionally, EndoS is a key enzyme used in the chemoenzymatic synthesis of homogenously glycosylated antibodies with tailored Fc γ receptor-mediated effector functions. Despite the tremendous utility of this enzyme, the molecular basis of EndoS specificity for, and processing of, IgG antibodies has remained poorly understood. Here, we report the X-ray crystal structure of EndoS and provide a model of its encounter complex with its substrate, the IgG1 Fc domain. We show that EndoS is composed of five distinct protein domains, including glycosidase, leucine-rich repeat, hybrid Ig, carbohydrate binding module, and three-helix bundle domains, arranged in a distinctive V-shaped conformation. Our data suggest that the substrate enters the concave interior of the enzyme structure, is held in place by the carbohydrate binding module, and that concerted conformational changes in both enzyme and substrate are required for subsequent antibody deglycosylation. The EndoS structure presented here provides a framework from which novel endoglycosidases could be engineered for additional clinical and biotechnological applications. PMID:24753590

  15. Role of RopB in growth phase expression of the SpeB cysteine protease of Streptococcus pyogenes.

    PubMed

    Neely, Melody N; Lyon, William R; Runft, Donna L; Caparon, Michael

    2003-09-01

    The Rgg family of transcription regulators is widely distributed among gram-positive bacteria; however, how the members of this family control transcription is poorly understood. In the pathogen Streptococcus pyogenes, the Rgg family member RopB is required for transcription of the gene that encodes the secreted SpeB cysteine protease. Expression of the protease follows distinct kinetics that involves control of transcription in response to the growth phase. In this study, the contribution of RopB to growth phase control was examined. The gene encoding the protease (speB) and ropB are transcribed divergently from a 940-bp intergenic region. Primer extension analyses, in conjunction with reporter fusion studies, revealed that the major region controlling the transcription of both speB and ropB is adjacent to ropB and that the promoters for the two genes likely overlap. Furthermore, it was found that RopB is a DNA-binding protein that specifically binds to sequences in this control region. The interrelationship between ropB and speB expression was further reflected in the observation that transcription of ropB itself is subject to growth phase control. However, while expression of ropB from a promoter expressed during the early logarithmic phase of growth could complement a ropB deletion mutant, ectopic expression of ropB did not uncouple the expression of speB from its growth phase signal. These data implicate other factors in growth phase control and suggest that regulation of ropB expression itself is not the central mechanism of control. PMID:12923089

  16. Fibrinogen cleavage by the Streptococcus pyogenes extracellular cysteine protease and generation of antibodies that inhibit enzyme proteolytic activity.

    PubMed

    Matsuka, Y V; Pillai, S; Gubba, S; Musser, J M; Olmsted, S B

    1999-09-01

    The extracellular cysteine protease from Streptococcus pyogenes is a virulence factor that plays a significant role in host-pathogen interaction. Streptococcal protease is expressed as an inactive 40-kDa precursor that is autocatalytically converted into a 28-kDa mature (active) enzyme. Replacement of the single cysteine residue involved in formation of the enzyme active site with serine (C192S mutation) abolished detectable proteolytic activity and eliminated autocatalytic processing of zymogen to the mature form. In the present study, we investigated activity of the wild-type (wt) streptococcal protease toward human fibrinogen and bovine casein. The former is involved in blood coagulation, wound healing, and other aspects of hemostasis. Treatment with streptococcal protease resulted in degradation of the COOH-terminal region of fibrinogen alpha chain, indicating that fibrinogen may serve as an important substrate for this enzyme during the course of human infection. Polyclonal antibodies generated against recombinant 40- and 28-kDa (r40- and r28-kDa) forms of the C192S streptococcal protease mutant exhibited high enzyme-linked immunosorbent assay titers but demonstrated different inhibition activities toward proteolytic action of the wt enzyme. Activity of the wt protease was readily inhibited when the reaction was carried out in the presence of antibodies generated against r28-kDa C192S mutant. Antibodies produced against r40-kDa C192S mutant had no significant effect on proteolysis. These data suggest that the presence of the NH(2)-terminal prosegment prevents generation of functionally active antibodies and indicate that inhibition activity of antibodies most likely depends on their ability to bind the active-site region epitope(s) of the protein. PMID:10456870

  17. The luxS Gene of Streptococcus pyogenes Regulates Expression of Genes That Affect Internalization by Epithelial Cells

    PubMed Central

    Marouni, Mehran J.; Sela, Shlomo

    2003-01-01

    The gram-positive pathogen Streptococcus pyogenes was recently reported to possess a homologue of the luxS gene that is responsible for the production of autoinducer 2, which participates in quorum sensing of both gram-positive and gram-negative bacteria. To test the effect of LuxS on streptococcal internalization, a LuxS mutant was constructed in strain SP268, an invasive M3 serotype. Functional analysis of the mutant revealed that it was internalized by HEp-2 cells with higher efficiency than the wild type (wt). Several genes, including hasA (hyaluronic acid synthesis), speB (streptococcal pyrogenic exotoxin B), and csrR (capsule synthesis regulator), a part of a two-component regulatory system, are known to affect the internalization of strain SP268 (J. Jadoun, O. Eyal, and S. Sela, Infect. Immun. 70:462-469, 2002). Therefore, the expression of these genes in the mutant and in the wt was examined. LuxS mutation significantly reduced the mRNA level of speB and increased the mRNA level of emm3. No substantial effect was observed on transcription of hasA and csrR. Yet less hyaluronic acid capsule was expressed in the mutant. Further analysis revealed that luxS is under the regulation of the two-component global regulator CsrR. Our results indicate that LuxS activity in strain SP268 plays an important role in the expression of virulence factors associated with epithelial cell internalization. PMID:14500483

  18. Fibrinogen Cleavage by the Streptococcus pyogenes Extracellular Cysteine Protease and Generation of Antibodies That Inhibit Enzyme Proteolytic Activity

    PubMed Central

    Matsuka, Yury V.; Pillai, Subramonia; Gubba, Siddeswar; Musser, James M.; Olmsted, Stephen B.

    1999-01-01

    The extracellular cysteine protease from Streptococcus pyogenes is a virulence factor that plays a significant role in host-pathogen interaction. Streptococcal protease is expressed as an inactive 40-kDa precursor that is autocatalytically converted into a 28-kDa mature (active) enzyme. Replacement of the single cysteine residue involved in formation of the enzyme active site with serine (C192S mutation) abolished detectable proteolytic activity and eliminated autocatalytic processing of zymogen to the mature form. In the present study, we investigated activity of the wild-type (wt) streptococcal protease toward human fibrinogen and bovine casein. The former is involved in blood coagulation, wound healing, and other aspects of hemostasis. Treatment with streptococcal protease resulted in degradation of the COOH-terminal region of fibrinogen α chain, indicating that fibrinogen may serve as an important substrate for this enzyme during the course of human infection. Polyclonal antibodies generated against recombinant 40- and 28-kDa (r40- and r28-kDa) forms of the C192S streptococcal protease mutant exhibited high enzyme-linked immunosorbent assay titers but demonstrated different inhibition activities toward proteolytic action of the wt enzyme. Activity of the wt protease was readily inhibited when the reaction was carried out in the presence of antibodies generated against r28-kDa C192S mutant. Antibodies produced against r40-kDa C192S mutant had no significant effect on proteolysis. These data suggest that the presence of the NH2-terminal prosegment prevents generation of functionally active antibodies and indicate that inhibition activity of antibodies most likely depends on their ability to bind the active-site region epitope(s) of the protein. PMID:10456870

  19. Role of RopB in Growth Phase Expression of the SpeB Cysteine Protease of Streptococcus pyogenes

    PubMed Central

    Neely, Melody N.; Lyon, William R.; Runft, Donna L.; Caparon, Michael

    2003-01-01

    The Rgg family of transcription regulators is widely distributed among gram-positive bacteria; however, how the members of this family control transcription is poorly understood. In the pathogen Streptococcus pyogenes, the Rgg family member RopB is required for transcription of the gene that encodes the secreted SpeB cysteine protease. Expression of the protease follows distinct kinetics that involves control of transcription in response to the growth phase. In this study, the contribution of RopB to growth phase control was examined. The gene encoding the protease (speB) and ropB are transcribed divergently from a 940-bp intergenic region. Primer extension analyses, in conjunction with reporter fusion studies, revealed that the major region controlling the transcription of both speB and ropB is adjacent to ropB and that the promoters for the two genes likely overlap. Furthermore, it was found that RopB is a DNA-binding protein that specifically binds to sequences in this control region. The interrelationship between ropB and speB expression was further reflected in the observation that transcription of ropB itself is subject to growth phase control. However, while expression of ropB from a promoter expressed during the early logarithmic phase of growth could complement a ropB deletion mutant, ectopic expression of ropB did not uncouple the expression of speB from its growth phase signal. These data implicate other factors in growth phase control and suggest that regulation of ropB expression itself is not the central mechanism of control. PMID:12923089

  20. Heme-bound SiaA from Streptococcus pyogenes: Effects of Mutations and Oxidation State on Protein Stability

    PubMed Central

    Akbas, Neval; Draganova, Elizabeth B.; Block, Darci R.; Sook, Brian R.; Chan, Yau Fong; Zhuo, Joy; Eichenbaum, Zehava; Rodgers, Kenton R.; Dixon, Dabney W.

    2016-01-01

    The protein SiaA (HtsA) is part of a heme uptake pathway in Streptococcus pyogenes. In this report, we present the heme binding of the alanine mutants of the axial histidine (H229A) and methionine (M79A) ligands, as well as a lysine (K61A) and cysteine (C58A) located near the heme propionates (based on homology modeling) and a control mutant (C47A). pH titrations gave pKa values ranging from 9.0 to 9.5, close to the value of 9.7 for WT SiaA. Resonance Raman spectra of the mutants suggested that the ferric heme environment may be distinct from the wild-type; spectra of the ferrous states were similar. The midpoint reduction potential of the K61A mutant was determined by spectroelectrochemical titration to be 61 ± 3 mV vs. SHE, similar to the wild-type protein (68 ± 3 mV). The addition of guanidine hydrochloride showed two processes for protein denaturation, consistent with heme loss from protein forms differing by the orientation of the heme in the binding pocket (the half-life for the slower process was one to three days). The ease of protein unfolding was related to the strength of interaction of the residues with the heme. We hypothesize that kinetically facile but only partial unfolding, followed by a very slow approach to the completely unfolded state, may be a fundamental attribute of heme trafficking proteins. Small motions to release/transfer the heme accompanied by resistance to extensive unfolding may preserve the three dimensional form of the protein for further uptake and release. PMID:26746808

  1. Differences between macrolide-resistant and -susceptible Streptococcus pyogenes: importance of clonal properties in addition to antibiotic consumption.

    PubMed

    Silva-Costa, C; Friães, A; Ramirez, M; Melo-Cristino, J

    2012-11-01

    A steady decline in macrolide resistance among Streptococcus pyogenes (group A streptococci [GAS]) in Portugal was reported during 1999 to 2006. This was accompanied by alterations in the prevalence of macrolide resistance phenotypes and in the clonal composition of the population. In order to test whether changes in the macrolide-resistant population reflected the same changing patterns of the overall population, we characterized both macrolide-susceptible and -resistant GAS associated with a diagnosis of tonsillo-pharyngitis recovered in the period from 2000 to 2005 in Portugal. Pulsed-field gel electrophoresis (PFGE) profiling was the best predictor of emm type and the only typing method that could discriminate clones associated with macrolide resistance and susceptibility within each emm type. Six PFGE clusters were significantly associated with macrolide susceptibility: T3-emm3-ST406, T4-emm4-ST39, T1-emm1-ST28, T6-emm6-ST382, B3264-emm89-ST101/ST408, and T2-emm2-ST55. Four PFGE clusters were associated with macrolide resistance: T4-emm4-ST39, T28-emm28-ST52, T12-emm22-ST46, and T1-emm1-ST28. We found no evidence for frequent ongoing horizontal transfer of macrolide resistance determinants. The diversity of the macrolide-resistant population was lower than that of susceptible isolates. The differences found between the two populations suggest that the macrolide-resistant population of GAS has its own dynamics, independent of the behavior of the susceptible population. PMID:22908153

  2. The luxS gene of Streptococcus pyogenes regulates expression of genes that affect internalization by epithelial cells.

    PubMed

    Marouni, Mehran J; Sela, Shlomo

    2003-10-01

    The gram-positive pathogen Streptococcus pyogenes was recently reported to possess a homologue of the luxS gene that is responsible for the production of autoinducer 2, which participates in quorum sensing of both gram-positive and gram-negative bacteria. To test the effect of LuxS on streptococcal internalization, a LuxS mutant was constructed in strain SP268, an invasive M3 serotype. Functional analysis of the mutant revealed that it was internalized by HEp-2 cells with higher efficiency than the wild type (wt). Several genes, including hasA (hyaluronic acid synthesis), speB (streptococcal pyrogenic exotoxin B), and csrR (capsule synthesis regulator), a part of a two-component regulatory system, are known to affect the internalization of strain SP268 (J. Jadoun, O. Eyal, and S. Sela, Infect. Immun. 70:462-469, 2002). Therefore, the expression of these genes in the mutant and in the wt was examined. LuxS mutation significantly reduced the mRNA level of speB and increased the mRNA level of emm3. No substantial effect was observed on transcription of hasA and csrR. Yet less hyaluronic acid capsule was expressed in the mutant. Further analysis revealed that luxS is under the regulation of the two-component global regulator CsrR. Our results indicate that LuxS activity in strain SP268 plays an important role in the expression of virulence factors associated with epithelial cell internalization. PMID:14500483

  3. Analysis of a second bacteriophage hyaluronidase gene from Streptococcus pyogenes: evidence for a third hyaluronidase involved in extracellular enzymatic activity.

    PubMed Central

    Hynes, W L; Hancock, L; Ferretti, J J

    1995-01-01

    The hyaluronidase gene (hylP2) from a second group A streptococcal bacteriophage was isolated from ATCC T-type-22 hyaluronidase-producing strain 10403, a strain known to produce increased amounts of extracellular hyaluronidase. Sequence analysis of hylP2 and alignment with the previously described bacteriophage hyaluronidase gene (hylP) showed a high degree of similarity; however, hylP2 had deletions of regions specifying 34 amino acids. Twenty-eight of the deleted amino acids were in a region of HylP containing a series of collagen-like Gly-X-Y repeating units. By employing primers for both hylP and hylP2, PCR amplification resulted in fragments of appropriate sizes in 97% of the strains tested, with some strains producing two fragments, indicating the presence of at least two phages. When the hylP2 gene was introduced via a plasmid vector into a non-hyaluronidase-producing Streptococcus pyogenes strain, this strain was still unable to produce extracellular hyaluronidase, although intracellular hyaluronidase was present. These results, along with the absence of a typical N-terminal signal peptide, indicate that HylP2 is unable to be secreted into the extracellular milieu. Examination of more than 100 strains for production of hyaluronidase showed that only 23% of the strains produced extracellular hyaluronidase. One of these strains (strain 10403) contains a single bacteriophage hyaluronidase gene (hylP2) which, when inactivated by allelic replacement, still produces large amounts of extracellular hyaluronidase. These results suggest the presence of a different hyaluronidase gene encoding a protein that is actively secreted into the extracellular milieu. PMID:7622224

  4. Unique genomic arrangements in an invasive serotype M23 strain of Streptococcus pyogenes identify genes that induce hypervirulence.

    PubMed

    Bao, Yunjuan; Liang, Zhong; Booyjzsen, Claire; Mayfield, Jeffrey A; Li, Yang; Lee, Shaun W; Ploplis, Victoria A; Song, Hui; Castellino, Francis J

    2014-12-01

    The first genome sequence of a group A Streptococcus pyogenes serotype M23 (emm23) strain (M23ND), isolated from an invasive human infection, has been completed. The genome of this opacity factor-negative (SOF(-)) strain is composed of a circular chromosome of 1,846,477 bp. Gene profiling showed that this strain contained six phage-encoded and 24 chromosomally inherited well-known virulence factors, as well as 11 pseudogenes. The bacterium has acquired four large prophage elements, ΦM23ND.1 to ΦM23ND.4, harboring genes encoding streptococcal superantigen (ssa), streptococcal pyrogenic exotoxins (speC, speH, and speI), and DNases (spd1 and spd3), with phage integrase genes being present at one flank of each phage insertion, suggesting that the phages were integrated by horizontal gene transfer. Comparative analyses revealed unique large-scale genomic rearrangements that result in genomic rearrangements that differ from those of previously sequenced GAS strains. These rearrangements resulted in an imbalanced genomic architecture and translocations of chromosomal virulence genes. The covS sensor in M23ND was identified as a pseudogene, resulting in the attenuation of speB function and increased expression of the genes for the chromosomal virulence factors multiple-gene activator (mga), M protein (emm23), C5a peptidase (scpA), fibronectin-binding proteins (sfbI and fbp54), streptolysin O (slo), hyaluronic acid capsule (hasA), streptokinase (ska), and DNases (spd and spd3), which were verified by PCR. These genes are responsible for facilitating host epithelial cell binding and and/or immune evasion, thus further contributing to the virulence of M23ND. In conclusion, strain M23ND has become highly pathogenic as the result of a combination of multiple genetic factors, particularly gene composition and mutations, prophage integrations, unique genomic rearrangements, and regulated expression of critical virulence factors. PMID:25225265

  5. Copper Tolerance and Characterization of a Copper-Responsive Operon, copYAZ, in an M1T1 Clinical Strain of Streptococcus pyogenes

    PubMed Central

    Gordon, Lily D.; Fang, Zhong; Holder, Robert C.; Reid, Sean D.

    2015-01-01

    ABSTRACT Infection with Streptococcus pyogenes is associated with a breadth of clinical manifestations ranging from mild pharyngitis to severe necrotizing fasciitis. Elevated levels of intracellular copper are highly toxic to this bacterium, and thus, the microbe must tightly regulate the level of this metal ion by one or more mechanisms, which have, to date, not been clearly defined. In this study, we have identified two virulence mechanisms by which S. pyogenes protects itself against copper toxicity. We defined a set of putative genes, copY (for a regulator), copA (for a P1-type ATPase), and copZ (for a copper chaperone), whose expression is regulated by copper. Our results indicate that these genes are highly conserved among a range of clinical S. pyogenes isolates. The copY, copA, and copZ genes are induced by copper and are transcribed as a single unit. Heterologous expression assays revealed that S. pyogenes CopA can confer copper tolerance in a copper-sensitive Escherichia coli mutant by preventing the accumulation of toxic levels of copper, a finding that is consistent with a role for CopA in copper export. Evaluation of the effect of copper stress on S. pyogenes in a planktonic or biofilm state revealed that biofilms may aid in protection during initial exposure to copper. However, copper stress appears to prevent the shift from the planktonic to the biofilm state. Therefore, our results indicate that S. pyogenes may use several virulence mechanisms, including altered gene expression and a transition to and from planktonic and biofilm states, to promote survival during copper stress. IMPORTANCE Bacterial pathogens encounter multiple stressors at the host-pathogen interface. This study evaluates a virulence mechanism(s) utilized by S. pyogenes to combat copper at sites of infection. A better understanding of pathogen tolerance to stressors such as copper is necessary to determine how host-pathogen interactions impact bacterial survival during infections

  6. Paediatric obstructive sleep apnoea syndrome (OSAS) is associated with tonsil colonisation by Streptococcus pyogenes

    PubMed Central

    Viciani, Elisa; Montagnani, Francesca; Tavarini, Simona; Tordini, Giacinta; Maccari, Silvia; Morandi, Matteo; Faenzi, Elisa; Biagini, Cesare; Romano, Antonio; Salerni, Lorenzo; Finco, Oretta; Lazzi, Stefano; Ruggiero, Paolo; De Luca, Andrea; Barocchi, Michèle A.; Manetti, Andrea G. O.

    2016-01-01

    The involvement of pathogenic bacteria in obstructive sleep apnoea syndrome (OSAS) has yet to be elucidated. We investigated the possible role of group A streptococcus (GAS) in OSAS pathogenesis. In 40 tonsillectomized patients affected by OSAS and 80 healthy controls, significant (p < 0.0001) association of GAS with paediatric OSAS was found. Supernatant from streptolysin O (SLO)-producing GAS induced production of cysteinyl leukotrienes (CysLTs) in tonsil mononuclear cells (TMCs). CysLTs-treated TMCs showed significant (p < 0.05) proliferation of CD4+ T, CD19+ and CD19+CD27+CD38+ B lymphocytes. We discovered a SLO-dependent activation of CysLTs production through a pathway involving TOLL-like receptor 4 (TLR4), TIR-domain-containing adapter-inducing interferon-β (TRIF), Myeloid differentiation primary response gene 88 (MyD88), and p38 MAP Kinase. In conclusion, we hypothesise that GAS may contribute to paediatric tonsillar hyperplasia through CysLTs production induced by SLO, and this might explain its association with OSAS. PMID:26860261

  7. Mutation in csrR global regulator reduces Streptococcus pyogenes internalization.

    PubMed

    Jadoun, J; Sela, S

    2000-11-01

    Transposon (Tn 916) mutagenesis was employed to identify genes in group A streptococcus (GAS) that are involved in bacterial internalization by epithelial cells. One mutant displayed significantly reduced internalization efficiency and was therefore selected for further characterization. The mutant harbored a single Tn 916 insertion in csr, a genetic locus encoding a two-component regulatory system. Mutations in csr were found to derepress hyaluronic acid (HA) capsule synthesis. Since capsule expression has been previously reported to interfere with internalization of GAS, it was possible that the transposon exerted its inhibitory effect either by derepression of capsule synthesis, or by another mechanism. To study the effect of the csr mutation on bacterial internalization, isogenic mutants deficient in either csrR, hasA or both were generated. The hasA mutant adhered to and internalized into HEp-2 cells significantly better than the parent and the csrR mutant strains. The internalization efficiency of the double mutant (csrR(-)/hasA(-)) was reduced by seven-fold compared to that of the hasA mutant. These findings suggest that csrR affects streptococcal entry by modulating capsule expression as well as by another, yet unknown, mechanism. PMID:11031125

  8. Surface Export of GAPDH/SDH, a Glycolytic Enzyme, Is Essential for Streptococcus pyogenes Virulence

    PubMed Central

    Jin, Hong; Agarwal, Shivangi; Agarwal, Shivani; Pancholi, Vijay

    2011-01-01

    ABSTRACT Streptococcal surface dehydrogenase (SDH) (glyceraldehyde-3-phosphate dehydrogenase [GAPDH]) is an anchorless major multifunctional surface protein in group A Streptococcus (GAS) with the ability to bind important mammalian proteins, including plasmin(ogen). Although several biological properties of SDH are suggestive of its possible role in GAS virulence, its direct role in GAS pathogenesis has not been ascertained because it is essential for GAS survival. Thus, it has remained enigmatic as to “how and why” SDH/GAPDH is exported onto the bacterial surface. The present investigation highlights “why” SDH is exported onto the GAS surface. Differential microarray-based genome-wide transcript abundance analysis was carried out using a specific mutant, which was created by inserting a hydrophobic tail at the C-terminal end of SDH (M1-SDHHBtail) and thus preventing its exportation onto the GAS surface. This analysis revealed downregulation of the majority of genes involved in GAS virulence and genes belonging to carbohydrate and amino acid metabolism and upregulation of those related to lipid metabolism. The complete attenuation of this mutant for virulence in the mouse model and the decreased and increased virulence of the wild-type and mutant strains postcomplementation with SDHHBtail and SDH, respectively, indicated that the SDH surface export indeed regulates GAS virulence. M1-SDHHBtail also displayed unaltered growth patterns, increased intracellular ATP concentration and Hpr double phosphorylation, and significantly reduced pH tolerance, streptolysin S, and SpeB activities. These phenotypic and physiological changes observed in the mutant despite the unaltered expression levels of established transcriptional regulators further highlight the fact that SDH interfaces with many regulators and its surface exportation is essential for GAS virulence. PMID:21628503

  9. Analysis of the role of CovR and CovS in the dissemination of Streptococcus pyogenes in invasive skin disease.

    PubMed

    Dalton, Tracy L; Hobb, Rhonda I; Scott, June R

    2006-05-01

    The global regulatory two-component system CovR/S controls expression of about 15% of the Streptococcus pyogenes (group A streptococcus; GAS) genome. Recently, we found that CovS plays a pivotal role in general stress response of this strictly human pathogen. Therefore, we expected that both CovS and CovR might affect virulence. In this work, mice were inoculated subcutaneously with isogenic nonpolar covR and covS deletion-substitution mutants and the isogenic wild-type strain. The covS mutant behaved like the wild-type parental strain in terms of resulting lesion appearance and invasive disease leading to death. This is in agreement with previous results suggesting that the absence of its cognate sensor kinase does not affect the ability of CovR to become phosphorylated and cause repression of its regulon. However, two different covR deletion-substitution mutants caused significantly less invasive disease and death in the mice than the wild-type parental strain, although the local lesions produced by the covR mutants were more severe and purulent than those resulting from the wild-type GAS strain. Thus, it appears that production of CovR increases the ability of S. pyogenes to cause severe invasive disease in this mouse model and therefore is an important virulence factor for this organism. PMID:16542816

  10. Epidemiology and Molecular Characterization of Macrolide-Resistant Streptococcus pyogenes in Taiwan

    PubMed Central

    Huang, Chia-Ying; Lai, Jui-Fen; Huang, I-Wen; Chen, Pei-Chen; Wang, Hui-Ying; Shiau, Yih-Ru; Cheng, Ya-Wen; Hsieh, Li-Yun; Chang, Shan-Chwen

    2014-01-01

    Our multicenter nationwide surveillance data indicated that erythromycin (ERY) resistance among group A Streptococcus (GAS) isolates in Taiwan declined from 53.1% in 1998 and 2000 to 14.6% in 2002 and 2004 and 10.7% in 2006 to 2010 (P < 0.01). The present study aimed to assess the epidemiology of GAS in Taiwan and identify factors associated with ERY resistance. All 127 ERY-resistant (ERYr) isolates and 128 randomly selected ERY-susceptible (ERYs) isolates recovered from 1998 to 2010 were emm typed. ERYr isolates were also characterized by ERY resistance phenotype and mechanisms and pulsed-field gel electrophoresis (PFGE). Multilocus sequence typing was performed on selected ERYr isolates. The predominant emm types in ERYr isolates were emm22 (n = 33, 26.0%), emm12 (n = 24, 18.9%), emm4 (n = 21, 16.5%), and emm106 (n = 15, 11.8%). In ERYs isolates, emm12 (n = 27, 21.9%), emm1 (n = 18, 14.1%), emm106 (n = 16, 12.5%), and emm11 (n = 9, 7.1%) predominated. The most common ERY resistance phenotype was the M phenotype (resistant to macrolides) (70.9%), with all but one isolate carrying mef(A), followed by the constitutive macrolide-lincosamide-streptogramin B resistance (cMLSB) phenotype (26.8%), with isolates carrying erm(B) or erm(TR). ERYr isolates of the emm12-sequence type 36 (ST36) lineage with the cMLSB phenotype were mostly present before 2004, while those of the emm22-ST46 lineage with the M phenotype predominated in later years. Recovery from respiratory (throat swab) specimens was an independent factor associated with ERY resistance. emm1 and emm11 GAS isolates were significantly associated with ERYs, while emm22 was detected only in ERYr GAS. In addition, emm106 isolates were prevalent among the abscess/pus isolates, whereas emm12 isolates were strongly associated with a respiratory (throat) origin. In addition to identifying factors associated with ERY resistance in GAS, our study provides helpful information on the changing GAS epidemiology in Taiwan. PMID

  11. Analysis of Streptococcus pyogenes promoters by using novel Tn916-based shuttle vectors for the construction of transcriptional fusions to chloramphenicol acetyltransferase.

    PubMed Central

    Geist, R T; Okada, N; Caparon, M G

    1993-01-01

    We have developed a series of shuttle vectors based on the conjugative transposon Tn916 that have been designed for the analysis of transcriptional regulation in Streptococcus pyogenes and other gram-positive bacteria. Designated the pVIT vectors (vectors for integration into Tn916), the vectors are small, stable plasmids in Escherichia coli to facilitate the fusion of promoters from cloned S. pyogenes genes to a promoterless gene which encodes chloramphenicol acetyltransferase. The vectors each contain one or more small regions of Tn916 to direct the integration of the transcriptional fusion into the transposon via homologous recombination following transformation of S. pyogenes or other suitable gram-positive hosts. Integration can be monitored by the inactivation or replacement of an antibiotic resistance determinant in modified derivatives of Tn916. Promoter activity can then be quantitated by the determination of chloramphenicol acetyltransferase-specific activity. In addition, since integration is into loci that do not disrupt the conjugative transpositional functions of Tn916, the vectors are useful for analysis of regulation in strains that are difficult or impossible to transform and can be introduced into these strains by conjugation following transformation of an intermediate host. The promoters for the genes which encode both the M protein and protein F of S. pyogenes were active in pVIT vectors, as was the region which controls transcription of mry, a trans-acting positive regulator of M protein expression. However, neither of the two characterized promoters for mry demonstrated activity when independently analyzed in pVIT-generated partial diploid strains, suggesting that regulation of mry is more complex than predicted by current models. The broad host range of Tn916 should make the pVIT vectors useful for analysis of regulation in numerous other bacterial species. PMID:8244925

  12. Factor H Binds to the Hypervariable Region of Many Streptococcus pyogenes M Proteins but Does Not Promote Phagocytosis Resistance or Acute Virulence

    PubMed Central

    Kristensen, Bodil M.; Olsen, John E.; Harris, Claire L.; Ufret-Vincenty, Rafael L.; Stålhammar-Carlemalm, Margaretha; Lindahl, Gunnar

    2013-01-01

    Many pathogens express a surface protein that binds the human complement regulator factor H (FH), as first described for Streptococcus pyogenes and the antiphagocytic M6 protein. It is commonly assumed that FH recruited to an M protein enhances virulence by protecting the bacteria against complement deposition and phagocytosis, but the role of FH-binding in S. pyogenes pathogenesis has remained unclear and controversial. Here, we studied seven purified M proteins for ability to bind FH and found that FH binds to the M5, M6 and M18 proteins but not the M1, M3, M4 and M22 proteins. Extensive immunochemical analysis indicated that FH binds solely to the hypervariable region (HVR) of an M protein, suggesting that selection has favored the ability of certain HVRs to bind FH. These FH-binding HVRs could be studied as isolated polypeptides that retain ability to bind FH, implying that an FH-binding HVR represents a distinct ligand-binding domain. The isolated HVRs specifically interacted with FH among all human serum proteins, interacted with the same region in FH and showed species specificity, but exhibited little or no antigenic cross-reactivity. Although these findings suggested that FH recruited to an M protein promotes virulence, studies in transgenic mice did not demonstrate a role for bound FH during acute infection. Moreover, phagocytosis tests indicated that ability to bind FH is neither sufficient nor necessary for S. pyogenes to resist killing in whole human blood. While these data shed new light on the HVR of M proteins, they suggest that FH-binding may affect S. pyogenes virulence by mechanisms not assessed in currently used model systems. PMID:23637608

  13. Streptococcus pyogenes Employs Strain-dependent Mechanisms of C3b Inactivation to Inhibit Phagocytosis and Killing of Bacteria.

    PubMed

    Agrahari, Garima; Liang, Zhong; Glinton, Kristofor; Lee, Shaun W; Ploplis, Victoria A; Castellino, Francis J

    2016-04-22

    Evasion of complement-mediated opsonophagocytosis enables group A Streptococcus pyogenes (GAS) to establish infection. Different strain-dependent mechanisms are employed by the host to accomplish this goal. In general, GAS inhibits the amplification of the complement cascade on its cell surface by facilitating the degradation of C3b, an opsonin, to an inactive product, inactivated C3b (iC3b), in a step catalyzed by factor I (FI) and its cofactor, factor H (FH), with or without the participation of human host plasmin (hPm). GAS recruits FH to its cell surface via FH receptors, which are transcriptionally controlled by the two-component cluster of virulence responder-sensor system. The manner in which FI-FH and hPm function together on GAS cells is unknown. Using GAS strain AP53, which strongly binds host human plasminogen/plasmin (hPg/hPm) directly via an hPg/hPm surface receptor (PAM), we show that both FI-FH and hPm sequentially cleave C3b. Whereas FI-FH proteolytically cleaves C3b into iC3b, PAM-bound hPm catalyzes cleavage of iC3b into multiple smaller peptides. Unlike AP53, GAS strain M23ND weakly binds FH and recruits hPg/hPm to its cell surface indirectly via fibrinogen bound to M-protein, M23. In this case, FH-FI cleaves C3b into iC3b, with negligible degradation of iC3b by hPm that is bound to fibrinogen on the cells. AP53 and M23ND display similar resistance to human neutrophil-mediated phagocytosis, which results in a corresponding high lethality in mice after injection of these cells. These results suggest that GAS utilizes diverse mechanisms to degrade C3b and thus to protect bacterial cells from the complement response of the host. PMID:26945067

  14. Virulence Gene Pool Detected in Bovine Group C Streptococcus dysgalactiae subsp. dysgalactiae Isolates by Use of a Group A S. pyogenes Virulence Microarray ▿

    PubMed Central

    Rato, Márcia G.; Nerlich, Andreas; Bergmann, René; Bexiga, Ricardo; Nunes, Sandro F.; Vilela, Cristina L.; Santos-Sanches, Ilda; Chhatwal, Gursharan S.

    2011-01-01

    A custom-designed microarray containing 220 virulence genes of Streptococcus pyogenes (group A Streptococcus [GAS]) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causing bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections, with the latter being used for comparative purposes, for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin S, glyceraldehyde-3-phosphate dehydrogenase, the plasminogen-binding M-like protein PAM, and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94 to 100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein, and the C5a peptidase precursor, were detected in all human isolates but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase, and/or streptodornase were detected in bovine isolates (72%) but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene encoding R28, were detected in all bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by reverse transcriptase PCR (RT-PCR). Phylogenetic analysis of superantigen gene sequences revealed a high level (>98%) of identity among genes of bovine GCS, of the horse pathogen Streptococcus equi subsp. equi, and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a nonhuman pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans. PMID:21525223

  15. A Two-Component Regulatory System, CsrR-CsrS, Represses Expression of Three Streptococcus pyogenes Virulence Factors, Hyaluronic Acid Capsule, Streptolysin S, and Pyrogenic Exotoxin B

    PubMed Central

    Heath, Andrew; DiRita, Victor J.; Barg, Neil L.; Engleberg, N. Cary

    1999-01-01

    Certain Tn916 insertions in the chromosome of an M1-type, nonmucoid Streptococcus pyogenes isolate (MGAS166) were previously shown to result in stable mucoidy with increased expression of the capsular synthetic genes. The transposon insertions in these strains are directly upstream of an apparent operon encoding a two-component regulatory system, designated csrR-csrS. Compared with MGAS166, these mucoid mutants are more hemolytic and cause significantly more tissue damage in a murine model of skin infection. To extend these observations, we constructed an in-frame deletion in the gene encoding the response regulator, csrR, and we evaluated the expression of other known S. pyogenes virulence factors. We discovered that csrR mutants have enhanced transcription of sagA, a gene associated with streptolysin S (SLS) and speB, the gene encoding pyrogenic exotoxin B (SpeB). The mutants also express substantially higher SLS activity and SpeB antigen in late-exponential-phase cultures. There is no change in expression of emm, scpA, sic, or cpa (genes encoding other S. pyogenes virulence factors). CsrR− strains but not the wild-type parental strain produce necrotizing lesions in a mouse model of subcutaneous infection. A double mutant with deletions in both csrR and the capsular synthesis genes caused fewer and smaller necrotic skin lesions than the csrR mutants. However, this nonmucoid csrR strain was more likely than the wild type to yield necrotic lesions, suggesting that mucoidy contributes to virulence in this model of infection but that there are other csrR-regulated factors involved in the production of necrotic lesions. PMID:10496909

  16. Dynamics of uterine infections with Escherichia coli, Streptococcus uberis and Trueperella pyogenes in post-partum dairy cows and their association with clinical endometritis.

    PubMed

    Wagener, K; Grunert, T; Prunner, I; Ehling-Schulz, M; Drillich, M

    2014-12-01

    The diversity and dynamics of the uterine microbiota of dairy cows are poorly understood although it is becoming increasingly evident that they play a crucial role in the development of metritis and endometritis. Fourier-transform infrared (FTIR) spectroscopy was used to monitor the bovine microbiota of 40 cows on the day of calving and days 3, 9, 15, and 21 after parturition, and to investigate the associations of selected species with clinical endometritis (CE). Trueperella pyogenes (43.5%), Escherichia coli (21.5%), Bacillus spp. (21.0%) and Streptococcus uberis (18.5%) were the most frequently isolated microbes. Analyses of different sampling time points revealed that the presence of S. uberis on day 3 increased the risk of subsequent T. pyogenes infection on day 9 (odds ratio [OR] = 5.1, 95% confidence interval [CI] = 1.2-22.6). T. pyogenes infection (OR = 36.0, 95% CI = 3.8-343.2) and retained fetal membranes (RFM) (OR = 12.4, 95%CI = 1.4-112.7) were significant risk factors for CE. Cows with S. uberis on day 3 tended to have greater odds of CE than S. uberis-negative cows (OR = 7.1, 95% CI = 0.9-55.6). Chemometric analysis revealed significant differences in the metabolic profile of S. uberis strains isolated from cows with different vaginal discharge scores. This is the first study showing the association of specific S. uberis subtypes with the uterine health status of post-partum dairy cows. The study demonstrates that uterine clearance is a highly dynamic process, during which time bacteria show distinct patterns of progression, and provides information about interactions between bacterial species involved in the occurrence of CE. PMID:25439441

  17. A two-component regulatory system, CsrR-CsrS, represses expression of three Streptococcus pyogenes virulence factors, hyaluronic acid capsule, streptolysin S, and pyrogenic exotoxin B.

    PubMed

    Heath, A; DiRita, V J; Barg, N L; Engleberg, N C

    1999-10-01

    Certain Tn916 insertions in the chromosome of an M1-type, nonmucoid Streptococcus pyogenes isolate (MGAS166) were previously shown to result in stable mucoidy with increased expression of the capsular synthetic genes. The transposon insertions in these strains are directly upstream of an apparent operon encoding a two-component regulatory system, designated csrR-csrS. Compared with MGAS166, these mucoid mutants are more hemolytic and cause significantly more tissue damage in a murine model of skin infection. To extend these observations, we constructed an in-frame deletion in the gene encoding the response regulator, csrR, and we evaluated the expression of other known S. pyogenes virulence factors. We discovered that csrR mutants have enhanced transcription of sagA, a gene associated with streptolysin S (SLS) and speB, the gene encoding pyrogenic exotoxin B (SpeB). The mutants also express substantially higher SLS activity and SpeB antigen in late-exponential-phase cultures. There is no change in expression of emm, scpA, sic, or cpa (genes encoding other S. pyogenes virulence factors). CsrR- strains but not the wild-type parental strain produce necrotizing lesions in a mouse model of subcutaneous infection. A double mutant with deletions in both csrR and the capsular synthesis genes caused fewer and smaller necrotic skin lesions than the csrR mutants. However, this nonmucoid csrR strain was more likely than the wild type to yield necrotic lesions, suggesting that mucoidy contributes to virulence in this model of infection but that there are other csrR-regulated factors involved in the production of necrotic lesions. PMID:10496909

  18. The transcriptional terminator sequences downstream of the covR gene terminate covR/S operon transcription to generate covR monocistronic transcripts in Streptococcus pyogenes.

    PubMed

    Chiang-Ni, Chuan; Tsou, Chih-Cheng; Lin, Yee-Shin; Chuang, Woei-Jer; Lin, Ming-T; Liu, Ching-Chuan; Wu, Jiunn-Jong

    2008-12-31

    CovR/S is an important two component regulatory system, which regulates about 15% of the gene expression in Streptococcus pyogenes. The covR/S locus was identified as an operon generating an RNA transcript around 2.5-kb in size. In this study, we found the covR/S operon produced three RNA transcripts (around 2.5-, 1.0-, and 0.8-kb in size). Using RNA transcriptional terminator sequence prediction and transcriptional terminator analysis, we identified two atypical rho-independent terminator sequences downstream of the covR gene and showed these terminator sequences terminate RNA transcription efficiently. These results indicate that covR/S operon generates covR/S transcript and monocistronic covR transcripts. PMID:18824088

  19. The SpeB virulence factor of Streptococcus pyogenes, a multifunctional secreted and cell surface molecule with strepadhesin, laminin-binding and cysteine protease activity.

    PubMed

    Hytönen, J; Haataja, S; Gerlach, D; Podbielski, A; Finne, J

    2001-01-01

    The interactions between pathogenic bacteria and the host need to be resolved at the molecular level in order to develop novel vaccines and drugs. We have previously identified strepadhesin, a novel glycoprotein-binding activity in Streptococcus pyogenes, which is regulated by Mga, a regulator of streptococcal virulence factors. We have now identified the protein responsible for the strepadhesin activity and find that (i) strepadhesin activity is carried by SpeB, streptococcal pyrogenic exotoxin with cysteine protease activity; (ii) SpeB carries laminin-binding activity of the bacteria; and (iii) SpeB is not only a secreted molecule but also occurs unexpectedly tightly bound to the bacterial cell surface. Thus, in contrast to the previous view of SpeB as mainly an extracellular protease, it is also present as a streptococcal surface molecule with binding activity to laminin and other glycoproteins. PMID:11136470

  20. Toward New Therapeutics for Skin and Soft Tissue Infections: Propargyl-Linked Antifolates Are Potent Inhibitors of MRSA and Streptococcus pyogenes

    PubMed Central

    Scocchera, Eric W.; Martin, Brooke D.; Swain III, P. Whitney; Alverson, Jeremy B.; Priestley, Nigel D.; Anderson, Amy C.; Wright, Dennis L.

    2012-01-01

    Hospital- and community-acquired, complicated skin and soft tissue infections, often attributed to Staphylococcus aureus and Streptococcus pyogenes, present a significant health burden that is associated with increased health care costs and mortality. As these two species are difficult to discern on diagnosis and are associated with differential profiles of drug resistance, the development of an efficacious antibacterial agent that targets both organisms is a high priority. Herein we describe a structure-based drug development effort that has produced highly potent inhibitors of dihydrofolate reductase from both species. Optimized propargyl-linked antifolates containing a key pyridyl substituent display antibacterial activity against both methicillin-resistant S. aureus and S. pyogenes at MIC values below 0.1 µg/mL and minimal cytotoxicity against mammalian cells. Further evaluation against a panel of clinical isolates shows good efficacy against a range of important phenotypes such as hospital- and community-acquired strains as well as strains resistant to vancomycin. PMID:22347365

  1. Regulation of SpeB in Streptococcus pyogenes by pH and NaCl: a Model for In Vivo Gene Expression†

    PubMed Central

    Loughman, Jennifer A.; Caparon, Michael

    2006-01-01

    For a pathogen such as Streptococcus pyogenes, ecological success is determined by its ability to sense the environment and mount an appropriate adaptive transcriptional response. Thus, determining conditions for analyses of gene expression in vitro that are representative of the in vivo environment is critical for understanding the contributions of transcriptional response pathways to pathogenesis. In this study, we determined that the gene encoding the SpeB cysteine protease is up-regulated over the course of infection in a murine soft-tissue model. Conditions were identified, including growth phase, acidic pH, and an NaCl concentration of <0.1 M, that were required for expression of speB in vitro. Analysis of global expression profiles in response to these conditions in vitro identified a set of coregulated genes whose expression patterns showed a significant correlation with that of speB when examined during infection of murine soft tissues. This analysis revealed that a culture medium that promotes high levels of SpeB expression in vitro produced an expression profile that showed significant correlation to the profile observed in vivo. Taken together, these studies establish culture conditions that mimic in vivo expression patterns; that growth phase, pH, and NaCl may mimic relevant cues sensed by S. pyogenes during infection; and that identification of other environmental cues that alter expression of speB in vitro may provide insight into the signals that direct global patterns of gene expression in vivo. PMID:16385029

  2. SpeB modulates fibronectin-dependent internalization of Streptococcus pyogenes by efficient proteolysis of cell-wall-anchored protein F1.

    PubMed

    Nyberg, Patrik; Rasmussen, Magnus; Von Pawel-Rammingen, Ulrich; Björck, Lars

    2004-05-01

    SpeB is a cysteine proteinase and virulence determinant secreted by the important human pathogen Streptococcus pyogenes. Recent investigations have suggested a role for SpeB in streptococcal entry into human cells. However, conflicting data concerning the contribution of SpeB to internalization have been presented. Protein F1 is a cell-wall-attached fibronectin (Fn)-binding protein that is present in a majority of streptococcal isolates and is important for internalization. This study shows that protein F1 is efficiently degraded by SpeB, and that removal of protein F1 from the bacterial surface leads to reduced internalization. Whereas M1 protein and protein H, two additional surface proteins of S. pyogenes that bind human plasma proteins, are protected from proteolytic degradation by their ligands, protein F1 is readily cleaved by SpeB also when in complex with Fn. This finding, and the connection between the presence of Fn at the bacterial surface and entry into human cells, suggest that SpeB plays a role in the regulation of the internalization process. PMID:15133117

  3. In vitro activity of antimicrobial agents against streptococcus pyogenes isolated from different regions of Khyber Pakhtun Khwa Pakistan.

    PubMed

    Rizwan, Muhammad; Bakht, Jehan; Bacha, Nafees; Ahmad, Bashir

    2016-01-01

    The present study investigates the antibiotic resistance of S. pyogenes of 600 isolates collected from different body parts including throat and sputum were analyzed for their antimicrobial susceptibility to 5 antibiotics using the Kirby Bauer disc diffusion method. Based on different identification tests including, gram staining, beta hemolysis, catalase test and bacitracin sensitivity test, a total of 138 isolates were confirmed as S. pyogenes. The prevalence of S. pyogenes was 80% in sore throat and 29% in sputum samples. These isolates were further tested for antibiotics resistance using disk diffusion method. Out of 138 isolates, 49.27% isolates showed resistance towards cefixime, 28.98% towards cefotaxime and 17.39% towards ciprofloxacin, 17.39% towards ampicillin, 17.39% towards erythromycin, 15.94% towards streptomycin, 0.724% isolates towards chloromphenicol and 0% towards penicillin. Among the resistant isolates of S. pyogenes, 60.71% showed resistance towards cefixime, 57.14% towards ciprofloxacin, 57.14% towards streptomycin, 50% towards erythromycin and 25% towards cefotaxime. PMID:26826819

  4. Differential Secretomics of Streptococcus pyogenes Reveals a Novel Peroxide Regulator (PerR)-regulated Extracellular Virulence Factor Mitogen Factor3 (MF3)*

    PubMed Central

    Wen, Yao-Tseng; Tsou, Chih-Cheng; Kuo, Hsin-Tzu; Wang, Jie-Siou; Wu, Jiunn-Jong; Liao, Pao-Chi

    2011-01-01

    Streptococcus pyogenes is a human pathogen that causes various diseases. Numerous virulence factors secreted by S. pyogenes are involved in pathogenesis. The peroxide regulator (PerR) is associated with the peroxide resistance response and pathogenesis, but little is known about the regulation of the secretome involved in virulence. To investigate how PerR regulates the expression of the S. pyogenes secretome involved in virulence, a perR deficient mutant was used for comparative secretomic analysis with a wild-type strain. The conditioned medium containing secreted proteins of a wild-type strain and a perR deficient mutant at the stationary phase were collected for two-dimensional gel electrophoresis analysis, where protease inhibitors were applied to avoid the degradation of extracellular proteins. Differentially expressed protein spots were identified by liquid chromatography electrospray ionization tandem MS. More than 330 protein spots were detected on each gel. We identified 25 unique up-regulated proteins and 13 unique down-regulated proteins that were directly or indirectly controlled by the PerR regulator. Among these identified proteins, mitogen factor 3 (MF3), was selected to verify virulence and the expression of gene products. The data showed that MF3 protein levels in conditioned medium, as measured by immunoblot analysis, correlated well with protein levels determined by two-dimensional gel electrophoresis analysis. We also demonstrated that PerR bound to the promoter region of the mf3 gene. The result of an infection model showed that virulence was attenuated in the mf3 deficient mutant. Additional growth data of the wild-type strain and the mf3 deficient mutant suggested that MF3 played a role in digestion of exogenous DNA for promoting growth. To summarize, we conclude that PerR can positively regulate the expression of the secreted protein MF3 that contributes to the virulence in S. pyogenes. The analysis of the PerR-regulated secretome provided

  5. The histone-like protein Hlp is essential for growth of Streptococcus pyogenes: comparison of genetic approaches to study essential genes.

    PubMed

    Bugrysheva, Julia V; Froehlich, Barbara J; Freiberg, Jeffrey A; Scott, June R

    2011-07-01

    Selection of possible targets for vaccine and drug development requires an understanding of the physiology of bacterial pathogens, for which the ability to manipulate expression of essential genes is critical. For Streptococcus pyogenes (the group A streptococcus [GAS]), an important human pathogen, the lack of genetic tools for such studies has seriously hampered research. To address this problem, we characterized variants of the inducible Ptet cassette, in both sense and antisense contexts, as tools to regulate transcription from GAS genes. We found that although the three-operator Ptet construct [Ptet(O)3] had low uninduced expression, its induction level was low, while the two-operator construct [Ptet(O)2] was inducible to a high level but showed significant constitutive expression. Use of Ptet(O)3 in the chromosome allowed us to demonstrate previously that RNases J1 and J2 are required for growth of GAS. Here we report that the uninduced level from the chromosomally inserted Ptet(O)2 construct was too high for us to observe differential growth. For the highly expressed histone-like protein (Hlp) of GAS, neither chromosomal insertion of Ptet(O)2 or Ptet(O)3 nor their use on a high-copy-number plasmid to produce antisense RNA specific to hlp resulted in adequate differential expression. However, by replacing the ribosome binding site of hlp with an engineered riboswitch to control translation of Hlp, we demonstrated for the first time that this protein is essential for GAS growth. PMID:21531823

  6. Acquisition of the Sda1-encoding bacteriophage does not enhance virulence of the serotype M1 Streptococcus pyogenes strain SF370.

    PubMed

    Venturini, Carola; Ong, Cheryl-Lynn Y; Gillen, Christine M; Ben-Zakour, Nouri L; Maamary, Peter G; Nizet, Victor; Beatson, Scott A; Walker, Mark J

    2013-06-01

    The resurgence of invasive disease caused by Streptococcus pyogenes (group A Streptococcus [GAS]) in the past 30 years has paralleled the emergence and global dissemination of the highly virulent M1T1 clone. The GAS M1T1 clone has diverged from the ancestral M1 serotype by horizontal acquisition of two unique bacteriophages, encoding the potent DNase Sda1/SdaD2 and the superantigen SpeA, respectively. The phage-encoded DNase promotes escape from neutrophil extracellular traps and is linked to enhanced virulence of the M1T1 clone. In this study, we successfully used in vitro lysogenic conversion to transfer the Sda1-encoding phage from the M1T1 clonal strain 5448 to the nonclonal M1 isolate SF370 and determined the impact of this horizontal gene transfer event on virulence. Although Sda1 was expressed in SF370 lysogens, no capacity of the phage-converted strain to survive human neutrophil killing, switch to a hyperinvasive covRS mutant form, or cause invasive lethal infection in a humanized plasminogen mouse model was observed. This work suggests that the hypervirulence of the M1T1 clone is due to the unique synergic effect of the M1T1 clone bacteriophage-specific virulence factor Sda1 acting in concert with the M1T1 clone-specific genetic scaffold. PMID:23529618

  7. Acquisition of the Sda1-Encoding Bacteriophage Does Not Enhance Virulence of the Serotype M1 Streptococcus pyogenes Strain SF370

    PubMed Central

    Venturini, Carola; Ong, Cheryl-lynn Y.; Gillen, Christine M.; Ben-Zakour, Nouri L.; Maamary, Peter G.; Nizet, Victor; Beatson, Scott A.

    2013-01-01

    The resurgence of invasive disease caused by Streptococcus pyogenes (group A Streptococcus [GAS]) in the past 30 years has paralleled the emergence and global dissemination of the highly virulent M1T1 clone. The GAS M1T1 clone has diverged from the ancestral M1 serotype by horizontal acquisition of two unique bacteriophages, encoding the potent DNase Sda1/SdaD2 and the superantigen SpeA, respectively. The phage-encoded DNase promotes escape from neutrophil extracellular traps and is linked to enhanced virulence of the M1T1 clone. In this study, we successfully used in vitro lysogenic conversion to transfer the Sda1-encoding phage from the M1T1 clonal strain 5448 to the nonclonal M1 isolate SF370 and determined the impact of this horizontal gene transfer event on virulence. Although Sda1 was expressed in SF370 lysogens, no capacity of the phage-converted strain to survive human neutrophil killing, switch to a hyperinvasive covRS mutant form, or cause invasive lethal infection in a humanized plasminogen mouse model was observed. This work suggests that the hypervirulence of the M1T1 clone is due to the unique synergic effect of the M1T1 clone bacteriophage-specific virulence factor Sda1 acting in concert with the M1T1 clone-specific genetic scaffold. PMID:23529618

  8. CovRS-Regulated Transcriptome Analysis of a Hypervirulent M23 Strain of Group A Streptococcus pyogenes Provides New Insights into Virulence Determinants

    PubMed Central

    Bao, Yun-Juan; Liang, Zhong; Mayfield, Jeffrey A.; Lee, Shaun W.; Ploplis, Victoria A.

    2015-01-01

    ABSTRACT The two-component control of virulence (Cov) regulator (R)-sensor (S) (CovRS) regulates the virulence of Streptococcus pyogenes (group A Streptococcus [GAS]). Inactivation of CovS during infection switches the pathogenicity of GAS to a more invasive form by regulating transcription of diverse virulence genes via CovR. However, the manner in which CovRS controls virulence through expression of extended gene families has not been fully determined. In the current study, the CovS-regulated gene expression profiles of a hypervirulent emm23 GAS strain (M23ND/CovS negative [M23ND/CovS−]) and a noninvasive isogenic strain (M23ND/CovS+), under different growth conditions, were investigated. RNA sequencing identified altered expression of ∼349 genes (18% of the chromosome). The data demonstrated that M23ND/CovS− achieved hypervirulence by allowing enhanced expression of genes responsible for antiphagocytosis (e.g., hasABC), by abrogating expression of toxin genes (e.g., speB), and by compromising gene products with dispensable functions (e.g., sfb1). Among these genes, several (e.g., parE and parC) were not previously reported to be regulated by CovRS. Furthermore, the study revealed that CovS also modulated the expression of a broad spectrum of metabolic genes that maximized nutrient utilization and energy metabolism during growth and dissemination, where the bacteria encounter large variations in available nutrients, thus restructuring metabolism of GAS for adaption to diverse growth environments. From constructing a genome-scale metabolic model, we identified 16 nonredundant metabolic gene modules that constitute unique nutrient sources. These genes were proposed to be essential for pathogen growth and are likely associated with GAS virulence. The genome-wide prediction of genes associated with virulence identifies new candidate genes that potentially contribute to GAS virulence. IMPORTANCE The CovRS system modulates transcription of ∼18% of the genes in

  9. Elimination of Chromosomal Island SpyCIM1 from Streptococcus pyogenes Strain SF370 Reverses the Mutator Phenotype and Alters Global Transcription

    PubMed Central

    Nguyen, Scott V.; Rahman, Maliha; McCullor, Kimberly A.; King, Catherine J.; Fischetti, Vincent A.; McShan, W. Michael

    2015-01-01

    Streptococcus pyogenes chromosomal island M1 (SpyCIM1) integrates by site-specific recombination into the 5’ end of DNA mismatch repair (MMR) gene mutL in strain SF370SmR, blocking transcription of it and the downstream operon genes. During exponential growth, SpyCIM1 excises from the chromosome and replicates as an episome, restoring mutL transcription. This process is reversed in stationary phase with SpyCIM1 re-integrating into mutL, returning the cells to a mutator phenotype. Here we show that elimination of SpyCIM1 relieves this mutator phenotype. The downstream MMR operon genes, multidrug efflux pump lmrP, Holliday junction resolution helicase ruvA, and DNA base excision repair glycosylase tag, are also restored to constitutive expression by elimination of SpyCIM1. The presence of SpyCIM1 alters global transcription patterns in SF370SmR. RNA sequencing (RNA-Seq) demonstrated that loss of SpyCIM1 in the SpyCIM1 deletion mutant, CEM1Δ4, impacted the expression of over 100 genes involved in virulence and metabolism both in early exponential phase, when the SpyCIM1 is episomal, as well as at the onset of stationary phase, when SpyCIM1 has reintegrated into mutL. Among these changes, the up-regulation of the genes for the antiphagocytic M protein (emm1), streptolysin O (slo), capsule operon (hasABC), and streptococcal pyrogenic exotoxin (speB), are particularly notable. The expression pattern of the MMR operon confirmed our earlier observations that these genes are transcribed in early exponential phase but silenced as stationary phase is approached. Thus, the direct role of SpyCIM1 in causing the mutator phenotype is confirmed, and further, its influence upon the biology of S. pyogenes was found to impact multiple genes in addition to the MMR operon, which is a novel function for a mobile genetic element. We suggest that such chromosomal islands are a remarkable evolutionary adaptation to promote the survival of its S. pyogenes host cell in changing

  10. Comparative Genomics of the Mucoid and Nonmucoid Strains of Streptococcus pyogenes, Isolated from the Same Patient with Streptococcal Meningitis

    PubMed Central

    Yoshida, Haruno; Ishigaki, Yasuhito; Takizawa, Asako; Moro, Kunihiko; Kishi, Yuki; Takahashi, Takashi

    2015-01-01

    Mucoid (MTB313) and nonmucoid (MTB314) strains of group A streptococcus emm type 1 were simultaneously isolated from a single patient suffering from streptococcal meningitis. Whole-genome sequencing revealed that MTB313 carried a nucleotide substitution within rocA, which generated an amber termination codon. PMID:25883280

  11. Regulation of streptokinase expression by CovR/S in Streptococcus pyogenes: CovR acts through a single high-affinity binding site.

    PubMed

    Churchward, Gordon; Bates, Christopher; Gusa, Asiya A; Stringer, Virginia; Scott, June R

    2009-02-01

    The important human pathogen Streptococcus pyogenes (the group A streptococcus or GAS) produces many virulence factors that are regulated by the two-component signal transduction system CovRS (CsrRS). Dissemination of GAS infection originating at the skin has been shown to require production of streptokinase, whose transcription is repressed by CovR. In this work we have studied the interaction of CovR and phosphorylated CovR (CovR-P) with the promoter for streptokinase, Pska. We found that, in contrast to the other CovR-repressed promoters, Pska regulation by CovR occurs through binding at a single ATTARA consensus binding sequence (CB) that overlaps the -10 region of the promoter. Binding of CovR to other nearby consensus sequences occurs upon phosphorylation of the protein, but these other CBs do not contribute to the regulation of Pska by CovR. Thus, binding at a specific site does not necessarily indicate that the site is involved in regulation by CovR. In addition, at Pska, CovR binding to the different sites does not appear to involve cooperative interactions, which simplifies the analysis of CovR binding and gives us insight into the modes of interaction that occur between CovR and its specific DNA-binding sites. Finally, the observation that regulation of transcription from Pska occurs at a very low concentration of phosphorylated CovR may have important implications for the regulation of virulence gene expression during GAS infection. PMID:19202105

  12. RscA, a member of the MDR1 family of transporters, is repressed by CovR and required for growth of Streptococcus pyogenes under heat stress.

    PubMed

    Dalton, Tracy L; Collins, Julie T; Barnett, Timothy C; Scott, June R

    2006-01-01

    The ability of Streptococcus pyogenes (group A streptococcus [GAS]) to respond to changes in environmental conditions is essential for this gram-positive organism to successfully cause disease in its human host. The two-component system CovRS controls expression of about 15% of the GAS genome either directly or indirectly. In most operons studied, CovR acts as a repressor. We previously linked CovRS to the GAS stress response by showing that the sensor kinase CovS is required to inactivate the response regulator CovR so that GAS can grow under conditions of heat, acid, and salt stress. Here, we sought to identify CovR-repressed genes that are required for growth under stress. To do this, global transcription profiles were analyzed by microarrays following exposure to increased temperature (40 degrees C) and decreased pH (pH 6.0). The CovR regulon in an M type 6 strain of GAS was also examined by global transcriptional analysis. We identified a gene, rscA (regulated by stress and Cov), whose transcription was confirmed to be repressed by CovR and activated by heat and acid. RscA is a member of the MDR1 family of ABC transporters, and we found that it is required for growth of GAS at 40 degrees C but not at pH 6.0. Thus, for GAS to grow at 40 degrees C, CovR repression must be alleviated so that rscA can be transcribed to allow the production of this potential exporter. Possible explanations for the thermoprotective role of RscA in this pathogen are discussed. PMID:16352823

  13. Mode of Expression and Functional Characterization of FCT-3 Pilus Region-Encoded Proteins in Streptococcus pyogenes Serotype M49▿ †

    PubMed Central

    Nakata, Masanobu; Köller, Thomas; Moritz, Karin; Ribardo, Deborah; Jonas, Ludwig; McIver, Kevin S.; Sumitomo, Tomoko; Terao, Yutaka; Kawabata, Shigetada; Podbielski, Andreas; Kreikemeyer, Bernd

    2009-01-01

    The human pathogen Streptococcus pyogenes (group A streptococcus [GAS]) pilus components, suggested to play a role in pathogenesis, are encoded in the variable FCT (fibronectin- and collagen-binding T-antigen) region. We investigated the functions of sortase A (SrtA), sortase C2 (SrtC2), and the FctA protein of the most prevalent type 3 FCT region from a serotype M49 strain. Although it is considered a housekeeping sortase, SrtA's activity is involved in pilus formation in addition to its essentiality for GAS extracellular matrix protein binding, host cell adherence/internalization, survival in human blood, and biofilm formation. SrtC2 activity is crucial for pilus formation but dispensable for the other phenotypes tested in vitro. FctA is the major pilus backbone protein, simultaneously acting as the M49 T antigen, and requires SrtC2 and LepA, a signal peptidase I homologue, for monomeric surface expression and polymerization, respectively. Collagen-binding protein Cpa expression supports pilus formation at the pilus base. Immunofluorescence microscopy and fluorescence-activated cell sorting analysis revealed several unexpected expression patterns, as follows: (i) the monomeric pilus protein FctA was found exclusively at the old poles of GAS cells, (ii) FctA protein expression increased with lower temperatures, and (iii) FctA protein expression was restricted to 20 to 50% of a given GAS M49 population, suggesting regulation by a bistability mode. Notably, disruption of pilus assembly by sortase deletion rendered GAS serotype M49 significantly more aggressive in a dermonecrotic mouse infection model, indicating that sortase activity and, consequently, pilus expression allow a subpopulation of this GAS serotype to be less aggressive. Thus, pilus expression may not be a virulence attribute of GAS per se. PMID:18852238

  14. Role for Serine Protease HtrA (DegP) of Streptococcus pyogenes in the Biogenesis of Virulence Factors SpeB and the Hemolysin Streptolysin S

    PubMed Central

    Lyon, William R.; Caparon, Michael G.

    2004-01-01

    The serine protease HtrA is involved in the folding and maturation of secreted proteins, as well as in the degradation of proteins that misfold during secretion. Depletion of HtrA has been shown to affect the sensitivity of many organisms to thermal and environmental stresses, as well as being essential for virulence in many pathogens. In the present study, we compared the behaviors of several different HtrA mutants of the gram-positive pathogen Streptococcus pyogenes (group A streptococcus). Consistent with prior reports, insertional inactivation of htrA, the gene that encodes HtrA, resulted in a mutant that grew poorly at 37°C. However, an identical phenotype was observed when a similar polar insertion was placed immediately downstream of htrA in the streptococcal chromosome, suggesting that the growth defect of the insertion mutant was not a direct result of insertional inactivation of htrA. This conclusion was supported by the observation that a nonpolar deletion mutation of htrA did not produce the growth defect. However, this mutation did affect the production of several secreted virulence factors whose biogenesis requires extensive processing. For the SpeB cysteine protease, the loss of HtrA was associated with a failure to proteolytically process the zymogen to an active protease. For the streptolysin S hemolysin, a dramatic increase in hemolytic activity resulted from the depletion of HtrA. Interestingly, HtrA-deficient mutants were not attenuated in a murine model of subcutaneous infection. These data add to the growing body of information that implies an important role for HtrA in the biogenesis of secreted proteins in gram-positive bacteria. PMID:14977969

  15. Role for serine protease HtrA (DegP) of Streptococcus pyogenes in the biogenesis of virulence factors SpeB and the hemolysin streptolysin S.

    PubMed

    Lyon, William R; Caparon, Michael G

    2004-03-01

    The serine protease HtrA is involved in the folding and maturation of secreted proteins, as well as in the degradation of proteins that misfold during secretion. Depletion of HtrA has been shown to affect the sensitivity of many organisms to thermal and environmental stresses, as well as being essential for virulence in many pathogens. In the present study, we compared the behaviors of several different HtrA mutants of the gram-positive pathogen Streptococcus pyogenes (group A streptococcus). Consistent with prior reports, insertional inactivation of htrA, the gene that encodes HtrA, resulted in a mutant that grew poorly at 37 degrees C. However, an identical phenotype was observed when a similar polar insertion was placed immediately downstream of htrA in the streptococcal chromosome, suggesting that the growth defect of the insertion mutant was not a direct result of insertional inactivation of htrA. This conclusion was supported by the observation that a nonpolar deletion mutation of htrA did not produce the growth defect. However, this mutation did affect the production of several secreted virulence factors whose biogenesis requires extensive processing. For the SpeB cysteine protease, the loss of HtrA was associated with a failure to proteolytically process the zymogen to an active protease. For the streptolysin S hemolysin, a dramatic increase in hemolytic activity resulted from the depletion of HtrA. Interestingly, HtrA-deficient mutants were not attenuated in a murine model of subcutaneous infection. These data add to the growing body of information that implies an important role for HtrA in the biogenesis of secreted proteins in gram-positive bacteria. PMID:14977969

  16. Ultrahigh and High Resolution Structures and Mutational Analysis of Monomeric Streptococcus pyogenes SpeB Reveal a Functional Role for the Glycine-rich C-terminal Loop

    SciTech Connect

    González-Páez, Gonzalo E.; Wolan, Dennis W.

    2012-09-05

    Cysteine protease SpeB is secreted from Streptococcus pyogenes and has been studied as a potential virulence factor since its identification almost 70 years ago. Here, we report the crystal structures of apo mature SpeB to 1.06 {angstrom} resolution as well as complexes with the general cysteine protease inhibitor trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and a novel substrate mimetic peptide inhibitor. These structures uncover conformational changes associated with maturation of SpeB from the inactive zymogen to its active form and identify the residues required for substrate binding. With the use of a newly developed fluorogenic tripeptide substrate to measure SpeB activity, we determined IC{sub 50} values for trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and our new peptide inhibitor and the effects of mutations within the C-terminal active site loop. The structures and mutational analysis suggest that the conformational movements of the glycine-rich C-terminal loop are important for the recognition and recruitment of biological substrates and release of hydrolyzed products.

  17. Cleavage of interleukin 1 beta (IL-1 beta) precursor to produce active IL-1 beta by a conserved extracellular cysteine protease from Streptococcus pyogenes.

    PubMed Central

    Kapur, V; Majesky, M W; Li, L L; Black, R A; Musser, J M

    1993-01-01

    Streptococcal pyrogenic exotoxin B (SPE B), a conserved extracellular cysteine protease expressed by the human pathogenic bacterium Streptococcus pyogenes, was purified and shown to cleave inactive human interleukin 1 beta precursor (pIL-1 beta) to produce biologically active IL-1 beta. SPE B cleaves pIL-1 beta one residue amino-terminal to the site where a recently characterized endogenous human cysteine protease acts. IL-1 beta resulting from cleavage of pIL-1 beta by SPE B induced nitric oxide synthase activity in vascular smooth muscle cells and killed of the human melanoma A375 line. Two additional naturally occurring SPE B variants cleaved pIL-1 beta in a similar fashion. By demonstrating that SPE B catalyzes the formation of biologically active IL-1 beta from inactive pIL-1 beta, our data add a further dimension to an emerging theme in microbial pathogenesis that bacterial and viral virulence factors act directly on host cytokine pathways. The data also contribute to an enlarging literature demonstrating that microbial extracellular cysteine proteases are important in host-parasite interactions. Images Fig. 1 Fig. 2 Fig. 4 PMID:7689226

  18. A Streptococcus pyogenes derived collagen-like protein as a non-cytotoxic and non-immunogenic cross-linkable biomaterial

    PubMed Central

    Peng, Yong Y.; Yoshizumi, Ayumi; Danon, Stephen J.; Glattauer, Veronica; Prokopenko, Olga; Mirochnitchenko, Oleg; Yu, Zhuoxin; Inouye, Masayori; Werkmeister, Jerome A.; Brodsky, Barbara; Ramshaw, John A.M.

    2011-01-01

    A range of bacteria have been shown to contain collagen-like sequences that form triple-helical structures. Some of these proteins have been shown to form triple-helical motifs that are stable around body temperature without the inclusion of hydroxyproline or other secondary modifications to the protein sequence. This makes these collagen-like proteins particularly suitable for recombinant production as only a single gene product and no additional enzyme needs to be expressed. In the present study, we have examined the cytotoxicity and immunogenicity of the collagen-like domain from Streptococcus pyogenes Scl2 protein. These data show that the purified, recombinant collagen-like protein is not cytotoxic to fibroblasts and does not illicit an immune response in SJL/J and Arc mice. The freeze dried protein can be stabilised by glutaraldehyde cross-linking giving a material that is stable at >37°C and which supports cell attachment while not causing loss of viability. These data suggest that bacterial collagen-like proteins, which can be modified to include specific functional domains, could be a useful material for medical applications and as a scaffold for tissue engineering. PMID:20056274

  19. A role for trigger factor and an rgg-like regulator in the transcription, secretion and processing of the cysteine proteinase of Streptococcus pyogenes.

    PubMed Central

    Lyon, W R; Gibson, C M; Caparon, M G

    1998-01-01

    The ability of numerous microorganisms to cause disease relies upon the highly regulated expression of secreted proteinases. In this study, mutagenesis with a novel derivative of Tn4001 was used to identify genes required for the expression of the secreted cysteine proteinase (SCP) of the pathogenic Gram-positive bacterium Streptococcus pyogenes. Designated as Rop loci (regulation of proteinase), ropB is a rgg-like transcriptional activator required for transcription of the gene which encodes the proteinase. In contrast, ropA contributes post-transcriptionally to the secretion and processing of SCP and encodes a homologue of Trigger Factor, a peptidyl-prolyl isomerase and putative chaparone which is highly conserved in most bacterial species, but of unknown function. Analysis of additional ropA mutants demonstrated that RopA acts both to assist in targeting SCP to the secretory pathway and to promote the ability of the proprotein to establish an active conformation upon secretion. This latter function was dependent upon the peptidyl-prolyl isomerase domain of RopA and mutants that lacked this domain exhibited a bipartite deficiency manifested as a kinetic defect in autologous processing of the proprotein to the mature proteinase, and as a catalytic defect in the mature proteinase. These results provide insight into the function of Trigger Factor, the regulation of proteinase activity and the mechanism of secretion in Gram-positive bacteria. PMID:9799235

  20. Ultrahigh and High Resolution Structures and Mutational Analysis of Monomeric Streptococcus pyogenes SpeB Reveal a Functional Role for the Glycine-rich C-terminal Loop

    PubMed Central

    González-Páez, Gonzalo E.; Wolan, Dennis W.

    2012-01-01

    Cysteine protease SpeB is secreted from Streptococcus pyogenes and has been studied as a potential virulence factor since its identification almost 70 years ago. Here, we report the crystal structures of apo mature SpeB to 1.06 Å resolution as well as complexes with the general cysteine protease inhibitor trans-epoxysuccinyl-l-leucylamido(4-guanidino)butane and a novel substrate mimetic peptide inhibitor. These structures uncover conformational changes associated with maturation of SpeB from the inactive zymogen to its active form and identify the residues required for substrate binding. With the use of a newly developed fluorogenic tripeptide substrate to measure SpeB activity, we determined IC50 values for trans-epoxysuccinyl-l-leucylamido(4-guanidino)butane and our new peptide inhibitor and the effects of mutations within the C-terminal active site loop. The structures and mutational analysis suggest that the conformational movements of the glycine-rich C-terminal loop are important for the recognition and recruitment of biological substrates and release of hydrolyzed products. PMID:22645124

  1. A role for trigger factor and an rgg-like regulator in the transcription, secretion and processing of the cysteine proteinase of Streptococcus pyogenes.

    PubMed

    Lyon, W R; Gibson, C M; Caparon, M G

    1998-11-01

    The ability of numerous microorganisms to cause disease relies upon the highly regulated expression of secreted proteinases. In this study, mutagenesis with a novel derivative of Tn4001 was used to identify genes required for the expression of the secreted cysteine proteinase (SCP) of the pathogenic Gram-positive bacterium Streptococcus pyogenes. Designated as Rop loci (regulation of proteinase), ropB is a rgg-like transcriptional activator required for transcription of the gene which encodes the proteinase. In contrast, ropA contributes post-transcriptionally to the secretion and processing of SCP and encodes a homologue of Trigger Factor, a peptidyl-prolyl isomerase and putative chaparone which is highly conserved in most bacterial species, but of unknown function. Analysis of additional ropA mutants demonstrated that RopA acts both to assist in targeting SCP to the secretory pathway and to promote the ability of the proprotein to establish an active conformation upon secretion. This latter function was dependent upon the peptidyl-prolyl isomerase domain of RopA and mutants that lacked this domain exhibited a bipartite deficiency manifested as a kinetic defect in autologous processing of the proprotein to the mature proteinase, and as a catalytic defect in the mature proteinase. These results provide insight into the function of Trigger Factor, the regulation of proteinase activity and the mechanism of secretion in Gram-positive bacteria. PMID:9799235

  2. Antibacterial resistance in Streptococcus pyogenes (GAS) from healthy carriers and tonsillitis patients and association with antibacterial sale in the Faroe Islands.

    PubMed

    Magnussen, Marita D; Gaini, Shahin; Gislason, Hannes; Kristinsson, Karl G

    2016-04-01

    The aim of this study was to investigate the antibacterial resistance of Streptococcus pyogenes (GAS), and correlate the findings with the sales of erythromycin and tetracycline. General practitioners in the Faroe Islands were recruited to send oropharyngeal swabs. From an ongoing pneumococcal study, nasopharyngeal swabs were sampled from healthy children 0-7 years of age. Erythromycin susceptibility data from Iceland were obtained from the reference laboratory at the Landspitali University Hospital. Susceptibility testing in the Faroe Islands and Iceland was performed according to CLSI methods and criteria. The resistance rate to erythromycin and tetracycline found in patients in the Faroe Islands in 2009/2010 was 6% and 30% respectively. Tetracycline resistance in patients declined significantly from 2009 to 2010 (37-10%, p-value = 0.006 < 0.05) and differed significantly between age groups (p-value = 0.03 < 0.05). In Iceland, there was a peak in erythromycin resistance in 2008 (44%) and a substantial decrease in 2009 (5%). Although the prevalence of erythromycin and tetracycline resistance in the Faroe Islands and Iceland may be associated with antimicrobial use, sudden changes can occur with the introduction of new resistant clones. PMID:26833774

  3. SpyA, a C3-Like ADP-Ribosyltransferase, Contributes to Virulence in a Mouse Subcutaneous Model of Streptococcus pyogenes Infection ▿ † ‡

    PubMed Central

    Hoff, Jessica S.; DeWald, Mark; Moseley, Steve L.; Collins, Carleen M.; Voyich, Jovanka M.

    2011-01-01

    Streptococcus pyogenes is an important human pathogen with an expansive repertoire of verified and putative virulence factors. Here we demonstrate that a mutant deficient in the production of the streptococcal ADP-ribosyltransferase SpyA generates lesions of reduced size in a subcutaneous mouse infection model. At early stages of infection, when the difference in lesion size is first established, inflamed tissue isolated from lesions of mice infected with spyA mutant bacteria has higher levels of mRNA encoding the chemokines CXCL1 and CCL2 than does tissue isolated from mice infected with wild-type bacteria. In addition, at these early times, the mRNA levels for the gene encoding the intermediate filament vimentin are higher in the mutant-infected tissue. As wound resolution progresses, mRNA levels of the gene encoding matrix metallopeptidase 2 are lower in mutant-infected tissue. Furthermore, we demonstrate that the spyA mutant is internalized more efficiently than wild-type bacteria by HeLa cells. We conclude that SpyA contributes to streptococcal pathogenesis in the mouse subcutaneous infection model. Our observations suggest that the presence of SpyA delays wound healing in this model. PMID:21422178

  4. Pyogenic infection and rheumatoid arthritis.

    PubMed Central

    Rowe, I. F.; Deans, A. C.; Keat, A. C.

    1987-01-01

    Ten episodes of severe pyogenic infection occurring in nine patients with rheumatoid arthritis are reported. There was a wide range of presenting features including pyoarthrosis in 7 episodes. Three cases presented with meningitis, bacterial endocarditis and probable multiple abscesses respectively. Infection was caused by Staphylococcus aureus in 7 episodes and by Staphylococcus epidermidis, Streptococcus pneumoniae and beta-haemolytic Streptococcus in each of one episode. Three infective episodes were fatal. Pyogenic, especially staphylococcal, infection should be considered in patients with rheumatoid arthritis with unexplained illness with or without sudden deterioration in joint symptoms. It is important to recognize and treat infection rapidly. Images Figure 1 Figure 2 PMID:3671222

  5. Preliminary pediatric clinical evaluation of the oral probiotic Streptococcus salivarius K12 in preventing recurrent pharyngitis and/or tonsillitis caused by Streptococcus pyogenes and recurrent acute otitis media

    PubMed Central

    Di Pierro, Francesco; Donato, Guido; Fomia, Federico; Adami, Teresa; Careddu, Domenico; Cassandro, Claudia; Albera, Roberto

    2012-01-01

    Background The oral probiotic Streptococcus salivarius K12 has been shown clearly to antagonize the growth of Streptococcus pyogenes, the most important bacterial cause of pharyngeal infections in humans, by releasing two bacteriocins named salivaricin A2 and salivaricin B. Unpublished observations indicate that it can also antagonize the growth of other bacteria involved in acute otitis media. Because of its ability to colonize the oral cavity and its safety profile, we have tested its efficacy in reducing the incidence of streptococcal pharyngitis and/or tonsillitis and episodes of acute otitis media. Methods We enrolled 82 children, including 65 with and 17 without a recent diagnosis of recurrent oral streptococcal pathology. Of those with recurrent pathology, 45 were treated daily for 90 days with an oral slow-release tablet containing five billion colony-forming units of S. salivarius K12 (Bactoblis®), and the remaining 20 served as an untreated control group. The 17 children without a recent diagnosis of recurrent oral pathology were used as an additional control group. After 90 days of treatment, a 6-month follow-up period without treatment was included to evaluate a possible persistent protective role for the previously administered product. Results The 41 children who completed the 90-day course of Bactoblis showed a reduction in their episodes of streptococcal pharyngeal infection (about 90%) and/or acute otitis media (about 40%), calculated by comparing infection rates in the previous year. The 90-day treatment also reduced the reported incidence of pharyngeal and ear infections by about 65% in the 6-month follow-up period during which the product was not administered. Subjects tolerated the product well, with no side effects or dropouts reported. Conclusion Prophylactic administration of S. salivarius K12 to children with a history of recurrent oral streptococcal pathology reduced episodes of streptococcal pharyngeal infections and/or tonsillitis as

  6. In Vitro Activity of the New Ketolide Telithromycin Compared with Those of Macrolides against Streptococcus pyogenes: Influences of Resistance Mechanisms and Methodological Factors

    PubMed Central

    Bemer-Melchior, Pascale; Juvin, Marie-Emmanuelle; Tassin, Sandrine; Bryskier, Andre; Schito, Gian Carlo; Drugeon, Henri-B.

    2000-01-01

    One hundred and seven clinical isolates of Streptococcus pyogenes, 80 susceptible to macrolides and 27 resistant to erythromycin A (MIC >0.5 μg/ml), were examined. The erythromycin A-lincomycin double-disk test assigned 7 resistant strains to the M-phenotype, 8 to the inducible macrolide, lincosamide, and streptogramin B resistance (iMLSB) phenotype, and 12 to the constitutive MLSB resistance (cMLSB) phenotype. MICs of erythromycin A, clarithromycin, azithromycin, roxithromycin, and clindamycin were determined by a broth microdilution method. MICs of telithromycin were determined by three different methods (broth microdilution, agar dilution, and E-test methods) in an ambient air atmosphere and in a 5 to 6% CO2 atmosphere. Erythromycin A resistance genes were investigated by PCR in the 27 erythromycin A-resistant isolates. MICs of erythromycin A and clindamycin showed six groups of resistant strains, groups A to F. iMLSB strains (A, B, and D groups) are characterized by two distinct patterns of resistance correlated with genotypic results. A- and B-group strains were moderately resistant to 14- and 15-membered ring macrolides and highly susceptible to telithromycin. All A- and B-group isolates harbored erm TR gene, D-group strains, highly resistant to macrolides and intermediately resistant to telithromycin (MICs, 1 to 16 μg/ml), were all characterized by having the ermB gene. All M-phenotype isolates (C group), resistant to 14- and 15-membered ring macrolides and susceptible to clindamycin and telithromycin, harbored the mefA gene. All cMLSB strains (E and F groups) with high level of resistance to macrolides, lincosamide, and telithromycin had the ermB gene. The effect of 5 to 6% CO2 was remarkable on resistant strains, by increasing MICs of telithromycin from 1 to 6 twofold dilutions against D-E- and F-group isolates. PMID:11036012

  7. Genetic inactivation of an extracellular cysteine protease (SpeB) expressed by Streptococcus pyogenes decreases resistance to phagocytosis and dissemination to organs.

    PubMed

    Lukomski, S; Burns, E H; Wyde, P R; Podbielski, A; Rurangirwa, J; Moore-Poveda, D K; Musser, J M

    1998-02-01

    Streptococcal pyrogenic exotoxin B (SpeB), a conserved cysteine protease expressed by virtually all Streptococcus pyogenes strains, has recently been shown to be an important virulence factor (S. Lukomski, S. Sreevatsan, C. Amberg, W. Reichardt, M. Woischnik, A. Podbielski, and J. M. Musser, J. Clin. Invest. 99:2574-2580, 1997). Genetic inactivation of SpeB significantly decreased the lethality of a serotype M49 strain for mice and abolished the lethality of a serotype M3 strain after intraperitoneal (i.p.) injection. In the present study, a wild-type M3 isolate and an M3 speB mutant derivative were used to investigate the mechanism responsible for altered virulence. Following i.p. injection, the mutant and wild-type strains induced virtually identical cellular inflammatory responses, characterized largely by an influx of polymorphonuclear leukocytes (PMNs). In addition, the mutant and wild-type strains rapidly entered the blood and were recovered from all organs examined. However, significantly fewer (P < 0.05) CFUs of the isogenic mutant derivative than of the wild-type parent strain were recovered from blood and organs. PMNs effectively cleared the M3 speB mutant from the peritoneum by 22 h, thereby sparing the host. In contrast, the wild-type M3 strain continued to replicate intraperitoneally and had the ability to kill phagocytes. This process allowed the wild-type strain to continuously disseminate, resulting in host death. Our results indicate that genetic inactivation of the cysteine protease decreased the resistance of the mutant to phagocytosis and impaired its subsequent dissemination to organs. These results provide insight into the detrimental effect of SpeB inactivation on virulence. PMID:9453640

  8. Genetic Inactivation of an Extracellular Cysteine Protease (SpeB) Expressed by Streptococcus pyogenes Decreases Resistance to Phagocytosis and Dissemination to Organs

    PubMed Central

    Lukomski, Slawomir; Burns, Eugene H.; Wyde, Philip R.; Podbielski, Andreas; Rurangirwa, Jacqueline; Moore-Poveda, Donna K.; Musser, James M.

    1998-01-01

    Streptococcal pyrogenic exotoxin B (SpeB), a conserved cysteine protease expressed by virtually all Streptococcus pyogenes strains, has recently been shown to be an important virulence factor (S. Lukomski, S. Sreevatsan, C. Amberg, W. Reichardt, M. Woischnik, A. Podbielski, and J. M. Musser, J. Clin. Invest. 99:2574–2580, 1997). Genetic inactivation of SpeB significantly decreased the lethality of a serotype M49 strain for mice and abolished the lethality of a serotype M3 strain after intraperitoneal (i.p.) injection. In the present study, a wild-type M3 isolate and an M3 speB mutant derivative were used to investigate the mechanism responsible for altered virulence. Following i.p. injection, the mutant and wild-type strains induced virtually identical cellular inflammatory responses, characterized largely by an influx of polymorphonuclear leukocytes (PMNs). In addition, the mutant and wild-type strains rapidly entered the blood and were recovered from all organs examined. However, significantly fewer (P < 0.05) CFUs of the isogenic mutant derivative than of the wild-type parent strain were recovered from blood and organs. PMNs effectively cleared the M3 speB mutant from the peritoneum by 22 h, thereby sparing the host. In contrast, the wild-type M3 strain continued to replicate intraperitoneally and had the ability to kill phagocytes. This process allowed the wild-type strain to continuously disseminate, resulting in host death. Our results indicate that genetic inactivation of the cysteine protease decreased the resistance of the mutant to phagocytosis and impaired its subsequent dissemination to organs. These results provide insight into the detrimental effect of SpeB inactivation on virulence. PMID:9453640

  9. Interleukin-17A Contributes to the Control of Streptococcus pyogenes Colonization and Inflammation of the Female Genital Tract

    PubMed Central

    Carey, Alison J.; Weinberg, Jason B.; Dawid, Suzanne R.; Venturini, Carola; Lam, Alfred K.; Nizet, Victor; Caparon, Michael G.; Walker, Mark J.; Watson, Michael E.; Ulett, Glen C.

    2016-01-01

    Postpartum women are at increased risk of developing puerperal sepsis caused by group A Streptococcus (GAS). Specific GAS serotypes, including M1 and M28, are more commonly associated with puerperal sepsis. However, the mechanisms of GAS genital tract infection are not well understood. We utilized a murine genital tract carriage model to demonstrate that M1 and M28 GAS colonization triggers TNF-α, IL-1β, and IL-17A production in the female genital tract. GAS-induced IL-17A significantly influences streptococcal carriage and alters local inflammatory responses in two genetically distinct inbred strains of mice. An absence of IL-17A or the IL-1 receptor was associated with reduced neutrophil recruitment to the site of infection; and clearance of GAS was significantly attenuated in IL-17A−/− mice and Rag1−/− mice (that lack mature lymphocytes) but not in mice deficient for the IL-1 receptor. Together, these findings support a role for IL-17A in contributing to the control of streptococcal mucosal colonization and provide new insight into the inflammatory mediators regulating host-pathogen interactions in the female genital tract. PMID:27241677

  10. The Streptococcus pyogenes orphan protein tyrosine phosphatase, SP-PTP, possesses dual specificity and essential virulence regulatory functions.

    PubMed

    Kant, Sashi; Agarwal, Shivani; Pancholi, Preeti; Pancholi, Vijay

    2015-08-01

    Group A Streptococcus (GAS) is a human pathogen that causes high morbidity and mortality. GAS lacks a gene encoding tyrosine kinase but contains one encoding tyrosine phosphatase (SP-PTP). Thus, GAS is thought to lack tyrosine phosphorylation, and the physiological significance of SP-PTP is, therefore, questionable. Here, we demonstrate that SP-PTP possesses dual phosphatase specificity for Tyr- and Ser/Thr-phosphorylated GAS proteins, such as Ser/Thr kinase (SP-STK) and the SP-STK-phosphorylated CovR and WalR proteins. Phenotypic analysis of GAS mutants lacking SP-PTP revealed that the phosphatase activity per se positively regulates growth, cell division and the ability to adhere to and invade host cells. Furthermore, A549 human lung cells infected with GAS mutants lacking SP-PTP displayed increased Ser-/Thr-/Tyr-phosphorylation. SP-PTP also differentially regulates the expression of ∼50% of the total GAS genes, including several virulence genes potentially through the two-component regulators, CovR, WalR and PTS/HPr regulation of Mga. Although these mutants exhibit attenuated virulence, a GAS mutant overexpressing SP-PTP is hypervirulent. Our study provides the first definitive evidence for the presence and importance of Tyr-phosphorylation in GAS and the relevance of SP-PTP as an important therapeutic target. PMID:25939957

  11. Adhesin competence repressor (AdcR) from Streptococcus pyogenes controls adaptive responses to zinc limitation and contributes to virulence

    PubMed Central

    Sanson, Misu; Makthal, Nishanth; Flores, Anthony R.; Olsen, Randall J.; Musser, James M.; Kumaraswami, Muthiah

    2015-01-01

    Altering zinc bioavailability to bacterial pathogens is a key component of host innate immunity. Thus, the ability to sense and adapt to the alterations in zinc concentrations is critical for bacterial survival and pathogenesis. To understand the adaptive responses of group A Streptococcus (GAS) to zinc limitation and its regulation by AdcR, we characterized gene regulation by AdcR. AdcR regulates the expression of 70 genes involved in zinc acquisition and virulence. Zinc-bound AdcR interacts with operator sequences in the negatively regulated promoters and mediates differential regulation of target genes in response to zinc deficiency. Genes involved in zinc mobilization and conservation are derepressed during mild zinc deficiency, whereas the energy-dependent zinc importers are upregulated during severe zinc deficiency. Further, we demonstrated that transcription activation by AdcR occurs by direct binding to the promoter. However, the repression and activation by AdcR is mediated by its interactions with two distinct operator sequences. Finally, mutational analysis of the metal ligands of AdcR caused impaired DNA binding and attenuated virulence, indicating that zinc sensing by AdcR is critical for GAS pathogenesis. Together, we demonstrate that AdcR regulates GAS adaptive responses to zinc limitation and identify molecular components required for GAS survival during zinc deficiency. PMID:25510500

  12. Complement factor H allotype 402H is associated with increased C3b opsonization and phagocytosis of Streptococcus pyogenes.

    PubMed

    Haapasalo, Karita; Jarva, Hanna; Siljander, Tuula; Tewodros, Wezenet; Vuopio-Varkila, Jaana; Jokiranta, T Sakari

    2008-11-01

    The main virulence factor of group A streptococcus (GAS), M protein, binds plasma complement regulators factor H (FH) and FH-like protein 1 (FHL-1) leading to decreased opsonization. The M protein binding site on FH is within domain 7 in which also the age-related macular degeneration (AMD)-associated polymorphism Y402H is located. We studied if FH allotypes 402H and 402Y have different binding affinities to GAS. Plasma-derived FH allotype 402H and its recombinant fragment FH5-7(402H) showed decreased binding to several GAS strains. Growth of GAS in human blood taken from FH(402H) homozygous individuals was decreased when compared with blood taken from FH(402Y) homozygous individuals. The effect of the allotype 402H can be explained by combining the previous M protein mutagenesis data and the recently published crystal structure of FH6-8. In conclusion the data indicate that the AMD-associated allotype 402H leads to diminished binding of FH to GAS and increased opsonophagocytosis of the bacteria in blood. These results suggest that the homozygous presence of the allele 402H could be associated with decreased risk for severe GAS infections offering an explanation for the high frequency of the allele despite its association with visual impairment. PMID:18627465

  13. Use of flow cytometry for the adhesion analysis of Streptococcus pyogenes mutant strains to epithelial cells: investigation of the possible role of surface pullulanase and cysteine protease, and the transcriptional regulator Rgg

    PubMed Central

    Hytönen, Jukka; Haataja, Sauli; Finne, Jukka

    2006-01-01

    Background Flow cytometry based adherence assay is a potentially powerful but little used method in the study of bacterial binding to host structures. We have previously characterized a glycoprotein-binding activity in Streptococcus pyogenes called 'strepadhesin' binding to thyroglobulin, submaxillar mucin, fetuin and asialofetuin. We have identified surface-associated pullulanase (PulA) and cysteine protease (SpeB) as carriers of strepadhesin activity. In the present paper, we investigated the use of flow cytometry as a method to study the binding of Rgg, SpeB and PulA knock-out strains to cultured human epithelial cells. Results Streptococcal mutants were readily labelled with CFDA-SE and their binding to epithelial cells could be effectively studied by flow cytometry. A strain deficient in Rgg expression showed increased binding to the analyzed epithelial cell lines of various origin. Inactivation of SpeB had no effect on the adhesion, while PulA knock-out strains displayed decreased binding to the cell lines. Conclusion These results suggest that the flow cytometric assay is a valuable tool in the analysis of S. pyogenes adherence to host cells. It appears to be an efficient and sensitive tool for the characterization of interactions between the bacteria and the host at the molecular level. The results also suggest a role for Rgg regulated surface molecules, like PulA, in the adhesion of S. pyogenes to host cells. PMID:16504124

  14. Serine/Threonine Phosphatase (SP-STP), Secreted from Streptococcus pyogenes, Is a Pro-apoptotic Protein*

    PubMed Central

    Agarwal, Shivani; Agarwal, Shivangi; Jin, Hong; Pancholi, Preeti; Pancholi, Vijay

    2012-01-01

    This investigation illustrates an important property of eukaryote-type serine/threonine phosphatase (SP-STP) of group A Streptococcus (GAS) in causing programmed cell death of human pharyngeal cells. The secretory nature of SP-STP, its elevated expression in the intracellular GAS, and the ability of wild-type GAS but not the GAS mutant devoid of SP-STP to cause apoptosis of the host cell both in vitro and in vivo suggest that GAS deploys SP-STP as an important virulence determinant to exploit host cell machinery for its own advantage during infection. The exogenously added SP-STP is able to enter the cytoplasm and subsequently traverses into the nucleus in a temporal fashion to cause apoptosis of the pharyngeal cells. The programmed cell death induced by SP-STP, which requires active transcription and de novo protein synthesis, is also caspase-dependent. Furthermore, the entry of SP-STP into the cytoplasm is dependent on its secondary structure as the catalytically inactive SP-STP with an altered structure is unable to internalize and cause apoptosis. The ectopically expressed wild-type SP-STP was found to be in the nucleus and conferred apoptosis of Detroit 562 pharyngeal cells. However, the catalytically inactive SP-STP was unable to cause apoptosis even when intracellularly expressed. The ability of SP-STP to activate pro-apoptotic signaling cascades both in the cytoplasm and in the nucleus resulted in mitochondrial dysfunctioning and perturbation in the phosphorylation status of histones in the nucleus. SP-STP thus not only functions as a virulence regulator but also as an important factor responsible for host-related pathogenesis. PMID:22262847

  15. Mouse skin passage of a Streptococcus pyogenes Tn917 mutant of sagA/pel restores virulence, beta-hemolysis and sagA/pel expression without altering the position or sequence of the transposon

    PubMed Central

    Eberhard, Thomas H; Sledjeski, Darren D; Boyle, Michael DP

    2001-01-01

    Background Streptolysin S (SLS), the oxygen-stable hemolysin of Streptococcus pyogenes, has recently been shown to be encoded by the sagA/pel gene. Mutants lacking expression of this gene were less virulent in a dermonecrotic mouse infection model. Inactivation of the sagA/pel gene affect the expression of a variety of virulence factors in addition to the hemolysin. Insertion of a Tn917 transposon into the promoter region of the sagA/pel gene of S. pyogenes isolate CS101 eliminated expression of SLS, as well as decreased expression of the streptococcal pyrogenic exotoxin B, streptokinase and M protein. Results In this study a mouse skin air sac model was utilized to analyze the effect of biological pressures on expression of SLS and other sagA/pel regulated gene products. The insertion delayed the lethal effect of S. pyogenes in a mouse skin infection model. Despite this, bacteria could be cultured from the kidneys 72 hours post infection. These kidney-recovered isolates were β-hemolytic despite the transposon being present in its original location and had equivalent virulence to the wild type isolate when re-injected into naive mice. Northern blot analysis of the kidney-recovered isolates confirmed that transcription of sagA/pel was restored; however the expression of all sagA/pel regulated genes was not restored to wild type levels. Conclusions These results show that biological pressure present in the mouse can select for variants with altered expression of key virulence factor genes in S. pyogenes. PMID:11801184

  16. Binding of the global response regulator protein CovR to the sag promoter of Streptococcus pyogenes reveals a new mode of CovR-DNA interaction.

    PubMed

    Gao, Jinxin; Gusa, Asiya A; Scott, June R; Churchward, Gordon

    2005-11-25

    CovR (CsrR) is a response regulator of gene expression in Streptococcus pyogenes. It regulates approximately 15% of the genome, including the genes encoding several streptococcal virulence factors, and acts primarily as a repressor rather than an activator of transcription. We showed that in vitro, CovR is sufficient to repress transcription from the sag promoter, which directs the expression of streptolysin S, a hemolysin that can damage the membranes of eukaryotic cells and subcellular organelles. Repression was stimulated 10-fold by phosphorylation of CovR with acetyl phosphate. In contrast to binding at the has and cov promoters, which direct the expression of genes involved in capsule biosynthesis and of CovR itself, binding of CovR to Psag was highly cooperative. CovR bound to two extended regions of Psag, an upstream region overlapping the -35 and -10 promoter elements and a downstream region overlapping the translation initiation signals of the sagA gene. Each of these regions contains only a single consensus CovR binding sequence, ATTARA, which at the has promoter defines individual sites to which CovR binds non-cooperatively. At Phas and Pcov the T residues in the sequence ATTARA are important for CovR binding. However, using uracil interference experiments we find that although the ATTARA sequence in the Psag upstream region contains thymine residues important for CovR binding, important thymine residues in the Psag downstream region are located outside this sequence. Furthermore, again in contrast to its behavior at the has and cov promoters where phosphorylation of CovR leads to a 2-3-fold increase in DNA binding affinity, binding of CovR to the sag promoter was stimulated 8-32-fold by phosphorylation. We suggest that these differences in CovR binding mean that individual promoters will be repressed at different intracellular levels of phosphorylated CovR, permitting differences in the response of members of the CovR regulon to environmental and

  17. Nucleotide sequence of conjugative prophage Φ1207.3 (formerly Tn1207.3) carrying the mef(A)/msr(D) genes for efflux resistance to macrolides in Streptococcus pyogenes

    PubMed Central

    Iannelli, Francesco; Santagati, Maria; Santoro, Francesco; Oggioni, Marco R.; Stefani, Stefania; Pozzi, Gianni

    2014-01-01

    Genetic element Φ1207.3 (formerly Tn1207.3) is a prophage of Streptococcus pyogenes which carries the macrolide efflux resistance genes mef(A)/msr(D) and is capable of conjugal transfer among streptococci. Complete nucleotide sequence showed that Φ1207.3 is 52,491 bp in length and contained 58 open reading frames (ORFs). A manual homology-based annotation with functional prediction of the hypothetical gene product was possible only for 34 out of 58 ORFs. Φ1207.3 codes for two different C-methylation systems, several phage structural genes, a lysis cassette (composed by a holin and a peptidoglycan hydrolase), and three site-specific resolvases of the serine recombinase family. PMID:25538698

  18. The Extracellular Protein Factor Epf from Streptococcus pyogenes Is a Cell Surface Adhesin That Binds to Cells through an N-terminal Domain Containing a Carbohydrate-binding Module*

    PubMed Central

    Linke, Christian; Siemens, Nikolai; Oehmcke, Sonja; Radjainia, Mazdak; Law, Ruby H. P.; Whisstock, James C.; Baker, Edward N.; Kreikemeyer, Bernd

    2012-01-01

    Streptococcus pyogenes is an exclusively human pathogen. Streptococcal attachment to and entry into epithelial cells is a prerequisite for a successful infection of the human host and requires adhesins. Here, we demonstrate that the multidomain protein Epf from S. pyogenes serotype M49 is a streptococcal adhesin. An epf-deficient mutant showed significantly decreased adhesion to and internalization into human keratinocytes. Cell adhesion is mediated by the N-terminal domain of Epf (EpfN) and increased by the human plasma protein plasminogen. The crystal structure of EpfN, solved at 1.6 Å resolution, shows that it consists of two subdomains: a carbohydrate-binding module and a fibronectin type III domain. Both fold types commonly participate in ligand receptor and protein-protein interactions. EpfN is followed by 18 repeats of a domain classified as DUF1542 (domain of unknown function 1542) and a C-terminal cell wall sorting signal. The DUF1542 repeats are not involved in adhesion, but biophysical studies show they are predominantly α-helical and form a fiber-like stalk of tandem DUF1542 domains. Epf thus conforms with the widespread family of adhesins known as MSCRAMMs (microbial surface components recognizing adhesive matrix molecules), in which a cell wall-attached stalk enables long range interactions via its adhesive N-terminal domain. PMID:22977243

  19. EndoS from Streptococcus pyogenes is hydrolyzed by the cysteine proteinase SpeB and requires glutamic acid 235 and tryptophans for IgG glycan-hydrolyzing activity

    PubMed Central

    Allhorn, Maria; Olsén, Arne; Collin, Mattias

    2008-01-01

    Background The endoglycosidase EndoS and the cysteine proteinase SpeB from the human pathogen Streptococcus pyogenes are functionally related in that they both hydrolyze IgG leading to impairment of opsonizing antibodies and thus enhance bacterial survival in human blood. In this study, we further investigated the relationship between EndoS and SpeB by examining their in vitro temporal production and stability and activity of EndoS. Furthermore, theoretical structure modeling of EndoS combined with site-directed mutagenesis and chemical blocking of amino acids was used to identify amino acids required for the IgG glycan-hydrolyzing activity of EndoS. Results We could show that during growth in vitro S. pyogenes secretes the IgG glycan-hydrolyzing endoglycosidase EndoS prior to the cysteine proteinase SpeB. Upon maturation SpeB hydrolyzes EndoS that then loses its IgG glycan-hydrolyzing activity. Sequence analysis and structural homology modeling of EndoS provided a basis for further analysis of the prerequisites for IgG glycan-hydrolysis. Site-directed mutagenesis and chemical modification of amino acids revealed that glutamic acid 235 is an essential catalytic residue, and that tryptophan residues, but not the abundant lysine or the single cysteine residues, are important for EndoS activity. Conclusion We present novel information about the amino acid requirements for IgG glycan-hydrolyzing activity of the immunomodulating enzyme EndoS. Furthermore, we show that the cysteine proteinase SpeB processes/degrades EndoS and thus emphasize the importance of the SpeB as a degrading/processing enzyme of proteins from the bacterium itself. PMID:18182097

  20. Pyogenic sacroiliitis

    SciTech Connect

    Gordon, G.; Kabins, S.A.

    1980-07-01

    Seven definite and three probable cases of pyogenic sacroiliitis are presented and compared to 72 cases found in the English literature. Patients may present with a subacute localized or an acute systemic illness. Six of our patients were parenteral drug abusers. Sacroiliac uptake of gallium 67 citrate and/or technetium 99m pyrophosphate suggested the diagnosis which was confirmed by fluoroscopically controlled joint aspiration when blood cultures were sterile. Gram-negative organisms, group B streptococci and a Staphylococcus were isolated. Antibiotic treatment for four to six weeks was uniformly successful. Surgery should be reserved for abscess or sequestrum formation, neither of which were encountered in this series.

  1. Spontaneous mutations in the CsrRS two-component regulatory system of Streptococcus pyogenes result in enhanced virulence in a murine model of skin and soft tissue infection.

    PubMed

    Engleberg, N C; Heath, A; Miller, A; Rivera, C; DiRita, V J

    2001-04-01

    CsrS/CsrR is a 2-component system in Streptococcus pyogenes that negatively regulates hyaluronic capsule and several exotoxins. To detect spontaneous mutations in csrRS, mucoid and large colony variants of M1 strain MGAS166 were isolated from experimental murine skin infections. By use of complementation with a csrRS(+) plasmid, relevant mutations were also detected in 7 of 12 human clinical isolates. The presence of spontaneous mutants in mouse infection was associated with larger, more necrotic lesions. Most spontaneous changes in CsrR resulted from single amino acid substitutions, whereas most csrS mutations were frameshift or nonsense mutations. In 2 instances, IS1548 insertions were found in csrS. Experimental inoculation of mixtures of wild-type (wt) and csrRS(-) bacteria yielded larger, more necrotic lesions than did either strain at twice the inoculum, which suggests that these variants may exhibit pathogenic synergy. Spontaneous emergence of csrRS(-) mutants in vivo enhances the virulence of wt bacteria and increases severity of murine skin infection. PMID:11237829

  2. Streptococcus pyogenes CovRS mediates growth in iron starvation and in the presence of the human cationic antimicrobial peptide LL-37.

    PubMed

    Froehlich, Barbara J; Bates, Christopher; Scott, June R

    2009-01-01

    We found that the global regulatory two-component signal transduction system CovRS mediates the ability of group A streptococcus (GAS) to grow under two stresses encountered during infection: iron starvation and the presence of LL-37. We also showed that CovRS regulates transcription of the multimetal transporter operon that is important for GAS growth in a low concentration of iron. PMID:18996992

  3. Role of CsrR, Hyaluronic Acid, and SpeB in the Internalization of Streptococcus pyogenes M Type 3 Strain by Epithelial Cells

    PubMed Central

    Jadoun, Jeries; Eyal, Osnat; Sela, Shlomo

    2002-01-01

    Internalization of group A streptococcus by human epithelial cells has been extensively studied during the past 6 years. It is now clear that multiple mechanisms are involved in this process. We have previously demonstrated that the CsrR global regulator controls the internalization of an invasive M type 3 strain through regulation of the has (hyaluronic acid synthesis) operon, as well as another, unknown gene(s). Recently, it was reported that the CsrR-regulated cysteine protease (SpeB) is also involved in bacterial uptake. In this study we have examined the roles of CsrR, hyaluronic acid capsule, and SpeB in streptococcal internalization. We have constructed isogenic mutants of the M3 serotype deficient in the csrR, hasA, and speB genes and tested their ability to be internalized by HEp-2 epithelial cells. Inactivation of csrR abolished internalization, while inactivation of either hasA or speB increased the internalization efficiency. Mutation in csrR derepressed hasA transcription and lowered the activity of SpeB, while no effect on speB transcription was observed. The speB mutant expressed smaller amounts of capsule, while the hasA mutant transcribed more csrR and speB mRNAs. Thus, it seems that complex interactions between CsrR, SpeB, and capsule are involved in modulation of group A streptococcus internalization. PMID:11796571

  4. Role of CsrR, hyaluronic acid, and SpeB in the internalization of Streptococcus pyogenes M type 3 strain by epithelial cells.

    PubMed

    Jadoun, Jeries; Eyal, Osnat; Sela, Shlomo

    2002-02-01

    Internalization of group A streptococcus by human epithelial cells has been extensively studied during the past 6 years. It is now clear that multiple mechanisms are involved in this process. We have previously demonstrated that the CsrR global regulator controls the internalization of an invasive M type 3 strain through regulation of the has (hyaluronic acid synthesis) operon, as well as another, unknown gene(s). Recently, it was reported that the CsrR-regulated cysteine protease (SpeB) is also involved in bacterial uptake. In this study we have examined the roles of CsrR, hyaluronic acid capsule, and SpeB in streptococcal internalization. We have constructed isogenic mutants of the M3 serotype deficient in the csrR, hasA, and speB genes and tested their ability to be internalized by HEp-2 epithelial cells. Inactivation of csrR abolished internalization, while inactivation of either hasA or speB increased the internalization efficiency. Mutation in csrR derepressed hasA transcription and lowered the activity of SpeB, while no effect on speB transcription was observed. The speB mutant expressed smaller amounts of capsule, while the hasA mutant transcribed more csrR and speB mRNAs. Thus, it seems that complex interactions between CsrR, SpeB, and capsule are involved in modulation of group A streptococcus internalization. PMID:11796571

  5. Mutations in the control of virulence sensor gene from Streptococcus pyogenes after infection in mice lead to clonal bacterial variants with altered gene regulatory activity and virulence.

    PubMed

    Mayfield, Jeffrey A; Liang, Zhong; Agrahari, Garima; Lee, Shaun W; Donahue, Deborah L; Ploplis, Victoria A; Castellino, Francis J

    2014-01-01

    The cluster of virulence sensor (CovS)/responder (CovR) two-component operon (CovRS) regulates ∼15% of the genes of the Group A Streptococcal pyogenes (GAS) genome. Bacterial clones containing inactivating mutations in the covS gene have been isolated from patients with virulent invasive diseases. We report herein an assessment of the nature and types of covS mutations that can occur in both virulent and nonvirulent GAS strains, and assess whether a nonvirulent GAS can attain enhanced virulence through this mechanism. A group of mice were infected with a globally-disseminated clonal M1T1 GAS (isolate 5448), containing wild-type (WT) CovRS (5448/CovR+S+), or less virulent engineered GAS strains, AP53/CovR+S+ and Manfredo M5/CovR+S+. SpeB negative GAS clones from wound sites and/or from bacteria disseminated to the spleen were isolated and the covS gene was subjected to DNA sequence analysis. Numerous examples of inactivating mutations were found in CovS in all regions of the gene. The mutations found included frame-shift insertions and deletions, and in-frame small and large deletions in the gene. Many of the mutations found resulted in early translation termination of CovS. Thus, the covS gene is a genomic mutagenic target that gives GAS enhanced virulence. In cases wherein CovS- was discovered, these clonal variants exhibited high lethality, further suggesting that randomly mutated covS genes occur during the course of infection, and lead to the development of a more invasive infection. PMID:24968349

  6. Mutations in the Control of Virulence Sensor Gene from Streptococcus pyogenes after Infection in Mice Lead to Clonal Bacterial Variants with Altered Gene Regulatory Activity and Virulence

    PubMed Central

    Mayfield, Jeffrey A.; Liang, Zhong; Agrahari, Garima; Lee, Shaun W.; Donahue, Deborah L.; Ploplis, Victoria A.; Castellino, Francis J.

    2014-01-01

    The cluster of virulence sensor (CovS)/responder (CovR) two-component operon (CovRS) regulates ∼15% of the genes of the Group A Streptococcal pyogenes (GAS) genome. Bacterial clones containing inactivating mutations in the covS gene have been isolated from patients with virulent invasive diseases. We report herein an assessment of the nature and types of covS mutations that can occur in both virulent and nonvirulent GAS strains, and assess whether a nonvirulent GAS can attain enhanced virulence through this mechanism. A group of mice were infected with a globally-disseminated clonal M1T1 GAS (isolate 5448), containing wild-type (WT) CovRS (5448/CovR+S+), or less virulent engineered GAS strains, AP53/CovR+S+ and Manfredo M5/CovR+S+. SpeB negative GAS clones from wound sites and/or from bacteria disseminated to the spleen were isolated and the covS gene was subjected to DNA sequence analysis. Numerous examples of inactivating mutations were found in CovS in all regions of the gene. The mutations found included frame-shift insertions and deletions, and in-frame small and large deletions in the gene. Many of the mutations found resulted in early translation termination of CovS. Thus, the covS gene is a genomic mutagenic target that gives GAS enhanced virulence. In cases wherein CovS− was discovered, these clonal variants exhibited high lethality, further suggesting that randomly mutated covS genes occur during the course of infection, and lead to the development of a more invasive infection. PMID:24968349

  7. Relevance of spontaneous fabT mutations to a streptococcal toxic shock syndrome to non-streptococcal toxic shock syndrome transition in the novel-type Streptococcus pyogenes isolates that lost a salRK.

    PubMed

    Tatsuno, Ichiro; Okada, Ryo; Matsumoto, Masakado; Hata, Nanako; Matsui, Hideyuki; Zhang, Yan; Isaka, Masanori; Hasegawa, Tadao

    2016-05-01

    Streptococcus pyogenes is a causative agent of streptococcal toxic shock syndrome (STSS). Mutations in covR/S or rgg, negative regulators, can reportedly modulate the severity of infection in this pathogen. Recently, we showed that the regions encoding the SalR-SalK, a two-component regulatory system, were deleted in some emm 1-type isolates (named as 'novel-type'). In this study, the two novel 'STSS' isolates 10-85stss and 11-171stss were more virulent than the two novel 'non-STSS' isolates 11O-2non and 11T-3non when examined using a mouse model of invasive infection. Genome-sequencing experiments using the three strains 10-85stss , 11-171stss , and 11O-2non detected only one single nucleotide polymorphism that causes a non-synonymous mutation in fabT encoding a transcriptional regulator in strain 11O-2non . Loss of fabT reduced the high level of virulence observed in the STSS isolates to that in the non-STSS isolates, and introduction of an intact fabT compensated the lower virulence of 11O-2non , suggesting that the mutation in fabT, but not in covR/S or rgg, is involved in the differential virulence among the novel-type clinical isolates. This type of non-synonymous fabT mutation was also identified in 12 non-STSS isolates (including 11O-2non and 11T-3non ), and most of those 12 isolates showed impaired FabT function. PMID:26861052

  8. Complement-mediated opsonization of invasive group A Streptococcus pyogenes strain AP53 is regulated by the bacterial two-component cluster of virulence responder/sensor (CovRS) system.

    PubMed

    Agrahari, Garima; Liang, Zhong; Mayfield, Jeffrey A; Balsara, Rashna D; Ploplis, Victoria A; Castellino, Francis J

    2013-09-20

    Group A Streptococcus pyogenes (GAS) strain AP53 is a primary isolate from a patient with necrotizing fasciitis. These AP53 cells contain an inactivating mutation in the sensor component of the cluster of virulence (cov) responder (R)/sensor (S) two-component gene regulatory system (covRS), which enhances the virulence of the primary strain, AP53/covR(+)S(-). However, specific mechanisms by which the covRS system regulates the survival of GAS in humans are incomplete. Here, we show a key role for covRS in the regulation of opsonophagocytosis of AP53 by human neutrophils. AP53/covR(+)S(-) cells displayed potent binding of host complement inhibitors of C3 convertase, viz. Factor H (FH) and C4-binding protein (C4BP), which concomitantly led to minimal C3b deposition on AP53 cells, further showing that these plasma protein inhibitors are active on GAS cells. This resulted in weak killing of the bacteria by human neutrophils and a corresponding high death rate of mice after injection of these cells. After targeted allelic alteration of covS(-) to wild-type covS (covS(+)), a dramatic loss of FH and C4BP binding to the AP53/covR(+)S(+) cells was observed. This resulted in elevated C3b deposition on AP53/covR(+)S(+) cells, a high level of opsonophagocytosis by human neutrophils, and a very low death rate of mice infected with AP53/covR(+)S(+). We show that covRS is a critical transcriptional regulator of genes directing AP53 killing by neutrophils and regulates the levels of the receptors for FH and C4BP, which we identify as the products of the fba and enn genes, respectively. PMID:23928307

  9. Complement-mediated Opsonization of Invasive Group A Streptococcus pyogenes Strain AP53 Is Regulated by the Bacterial Two-component Cluster of Virulence Responder/Sensor (CovRS) System*

    PubMed Central

    Agrahari, Garima; Liang, Zhong; Mayfield, Jeffrey A.; Balsara, Rashna D.; Ploplis, Victoria A.; Castellino, Francis J.

    2013-01-01

    Group A Streptococcus pyogenes (GAS) strain AP53 is a primary isolate from a patient with necrotizing fasciitis. These AP53 cells contain an inactivating mutation in the sensor component of the cluster of virulence (cov) responder (R)/sensor (S) two-component gene regulatory system (covRS), which enhances the virulence of the primary strain, AP53/covR+S−. However, specific mechanisms by which the covRS system regulates the survival of GAS in humans are incomplete. Here, we show a key role for covRS in the regulation of opsonophagocytosis of AP53 by human neutrophils. AP53/covR+S− cells displayed potent binding of host complement inhibitors of C3 convertase, viz. Factor H (FH) and C4-binding protein (C4BP), which concomitantly led to minimal C3b deposition on AP53 cells, further showing that these plasma protein inhibitors are active on GAS cells. This resulted in weak killing of the bacteria by human neutrophils and a corresponding high death rate of mice after injection of these cells. After targeted allelic alteration of covS− to wild-type covS (covS+), a dramatic loss of FH and C4BP binding to the AP53/covR+S+ cells was observed. This resulted in elevated C3b deposition on AP53/covR+S+ cells, a high level of opsonophagocytosis by human neutrophils, and a very low death rate of mice infected with AP53/covR+S+. We show that covRS is a critical transcriptional regulator of genes directing AP53 killing by neutrophils and regulates the levels of the receptors for FH and C4BP, which we identify as the products of the fba and enn genes, respectively. PMID:23928307

  10. An N-Terminal Signal Peptide Of Vfr Protein Negatively Influences RopB-Dependent SpeB Expression and Attenuates Virulence in Streptococcus pyogenes

    PubMed Central

    Shelburne, Samuel A.; Olsen, Randall J.; Makthal, Nishanth; Brown, Nicholas G.; Sahasrabhojane, Pranoti; Watkins, Ebru M.; Palzkill, Timothy; Musser, James M.; Kumaraswami, Muthiah

    2015-01-01

    SUMMARY Streptococcal pyrogenic exotoxin B (SpeB) is an extracellular cysteine protease that is a critical virulence factor made by the major human pathogen group A Streptococcus (GAS). speB expression is dependent on the regulator of proteinase B (RopB) and is upregulated with increasing cell density and during infection. Because computer modeling suggested significant structural similarity between RopB and peptide-sensing regulatory proteins made by other Gram-positive bacteria, we hypothesized that speB expression is influenced by RopB-peptide interactions. Inactivation of the gene (vfr) encoding the virulence factor related (Vfr) protein resulted in increased speB transcript level during the exponential growth phase, whereas provision of only the amino-terminal region of Vfr comprising the secretion signal sequence in trans restored a wild-type speB expression profile. Addition of the culture supernatant from a Vfr signal peptide-expressing GAS strain restored wild-type speB transcript level to a vfr-inactivated isogenic mutant strain. A distinct peptide in the Vfr secretion signal sequence specifically bound to recombinant RopB. Finally, overexpression of the Vfr secretion signal sequence significantly decreased speB transcript level and attenuated GAS virulence in two mouse models of invasive infection. Taken together, these data delineate a previously unknown small peptide-mediated regulatory system that controls GAS virulence factor production. PMID:22040048

  11. Characterization of Two Novel Pyrogenic Toxin Superantigens Made by an Acute Rheumatic Fever Clone of Streptococcus pyogenes Associated with Multiple Disease Outbreaks

    PubMed Central

    Smoot, Laura M.; McCormick, John K.; Smoot, James C.; Hoe, Nancy P.; Strickland, Ian; Cole, Robert L.; Barbian, Kent D.; Earhart, Cathleen A.; Ohlendorf, Douglas H.; Veasy, L. George; Hill, Harry R.; Leung, Donald Y. M.; Schlievert, Patrick M.; Musser, James M.

    2002-01-01

    The pathogenesis of acute rheumatic fever (ARF) is poorly understood. We identified two contiguous bacteriophage genes, designated speL and speM, encoding novel inferred superantigens in the genome sequence of an ARF strain of serotype M18 group A streptococcus (GAS). speL and speM were located at the same genomic site in 33 serotype M18 isolates, and no nucleotide sequence diversity was observed in the 33 strains analyzed. Furthermore, the genes were absent in 13 non-M18 strains tested. These data indicate a recent acquisition event by a distinct clone of serotype M18 GAS. speL and speM were transcribed in vitro and upregulated in the exponential phase of growth. Purified SpeL and SpeM were pyrogenic and mitogenic for rabbit splenocytes and human peripheral blood mononuclear cells in picogram amounts. SpeL preferentially expanded human T cells expressing T-cell receptors Vβ1, Vβ5.1, and Vβ23, and SpeM had specificity for Vβ1 and Vβ23 subsets, indicating that both proteins had superantigen activity. SpeL was lethal in two animal models of streptococcal toxic shock, and SpeM was lethal in one model. Serologic studies indicated that ARF patients were exposed to serotype M18 GAS, SpeL, and SpeM. The data demonstrate that SpeL and SpeM are pyrogenic toxin superantigens and suggest that they may participate in the host-pathogen interactions in some ARF patients. PMID:12438391

  12. Group A Streptococcus Endometritis following Medical Abortion

    PubMed Central

    Gendron, Nicolas; Joubrel, Caroline; Nedellec, Sophie; Campagna, Jennifer; Agostini, Aubert; Doucet-Populaire, Florence; Casetta, Anne; Raymond, Josette; Kernéis, Solen

    2014-01-01

    Medical abortion is not recognized as a high-risk factor for invasive pelvic infection. Here, we report two cases of group A Streptococcus (GAS; Streptococcus pyogenes) endometritis following medical abortions with a protocol of oral mifepristone and misoprostol. PMID:24829245

  13. [Pyogenic sacroiliitis in pregnancy].

    PubMed

    Chimura, T; Banzai, M; Yamakawa, M; Sato, S; Satou, S

    2001-09-01

    Pyogenic sacroiliitis is an extremely rare disease in the field of obstetrics and gynecology, and especially for the cases discovered and treated during pregnancy, only five cases can be found in literature. We experienced one case of the disease in which the patient needed urgent hospitalization due to dysbasia caused by fever and pain at the left hip at the 27th week of her pregnancy. The patient was a 31-year-old primipara presenting typical clinical symptoms of pyogenic sacroiliitis along with evidence of severe infection as represented by fever of 39.7 degrees C and CRP of 12.6 mg/dl. She showed a good response to meropenem (MEPM) at 1 g twice a day for 8 days and then at 0.5 g twice a day for 2 days, followed by faropenem (FRPM) at 200 mg three times a day for 12 days, which successfully improved her subjective and objective findings as well as her laboratory test values, resulting in a complete cure. The definitive diagnosis of the disease in the patient was made on the basis of MRI findings, but no pathogen was identified. The patient was found to have marginal placenta previa as a complication, but she had an uneventful trans-vaginal delivery at the 37th week of her pregnancy and left hospital after both she and her baby showed favorable post-delivery progress. The case reported here is the first case of pyogenic sacroiliitis that has ever been discovered and treated during pregnancy in Japan. PMID:11729713

  14. Palatal pyogenic granulomaa.

    PubMed

    Mahabob, Nazargi; Kumar, Senthil; Raja, Subramani

    2013-07-01

    Pyogenic granuloma (PG) is a kind of inflammatory hyperplasia seen in the oral cavity. This term is a misnomer because the lesion is unrelated to infection. In reality it arises in response to various stimuli such as low-grade local irritation, traumatic injury or hormonal factors. It predominantly occurs in the second decade of life in young females possibly because of the vascular effects of female hormones. It is also called as pregnancy tumor because of its high frequency of occurrence during the early part of pregnancy. Even though, this lesion is non-neoplastic and treatment procedure is simple, it should be diagnosed correctly before proceeding with the treatment. The most common site for PGs is gingiva (75%) and rarely in the palate. In this case report, we are going to present very rare occurrence of pregnancy tumor in the hard palate. PMID:23956603

  15. Streptococcus viridans osteomyelitis and endocarditis following dental treatment: a case report.

    PubMed

    Choudhury, Maitrayee; Patel, Brijesh R; Patel, Minal; Bashir, Tariq

    2009-01-01

    Vertebral osteomyelitis is an uncommon complication of infective endocarditis with the organism Streptococcus viridans being a rare cause of the condition. This case highlights an unusual presentation of Streptococcus viridans associated with infective endocarditis and pyogenic osteomyelitis in a patient following a dental procedure. PMID:19918551

  16. Direct Host Plasminogen Binding to Bacterial Surface M-protein in Pattern D Strains of Streptococcus pyogenes Is Required for Activation by Its Natural Coinherited SK2b Protein*

    PubMed Central

    Chandrahas, Vishwanatha; Glinton, Kristofor; Liang, Zhong; Donahue, Deborah L.; Ploplis, Victoria A.; Castellino, Francis J.

    2015-01-01

    Streptokinase (SK), secreted by Group A Streptococcus (GAS), is a single-chain ∼47-kDa protein containing three consecutive primary sequence regions that comprise its α, β, and γ modules. Phylogenetic analyses of the variable β-domain sequences from different GAS strains suggest that SKs can be arranged into two clusters, SK1 and SK2, with a subdivision of SK2 into SK2a and SK2b. SK2b is secreted by skin-tropic Pattern D M-protein strains that also express plasminogen (human Pg (hPg)) binding Group A streptococcal M-protein (PAM) as its major cell surface M-protein. SK2a-expressing strains are associated with nasopharynx tropicity, and many of these strains express human fibrinogen (hFg) binding Pattern A-C M-proteins, e.g. M1. PAM interacts with hPg directly, whereas M1 binds to hPg indirectly via M1-bound hFg. Subsequently, SK is secreted by GAS and activates hPg to plasmin (hPm), thus generating a proteolytic surface on GAS that enhances its dissemination. Due to these different modes of hPg/hPm recognition by GAS, full characterizations of the mechanisms of activation of hPg by SK2a and SK2b and their roles in GAS virulence are important topics. To more fully examine these subjects, isogenic chimeric SK- and M-protein-containing GAS strains were generated, and the virulence of these chimeric strains were analyzed in mice. We show that SK and M-protein alterations influenced the virulence of GAS and were associated with the different natures of hPg activation and hPm binding. These studies demonstrate that GAS virulence can be explained by disparate hPg activation by SK2a and SK2b coupled with the coinherited M-proteins of these strains. PMID:26070561

  17. Pyogenic psoas abscess: analysis of 27 cases.

    PubMed

    Lin, M F; Lau, Y J; Hu, B S; Shi, Z Y; Lin, Y H

    1999-12-01

    From 1993 to 1998, 29 pyogenic psoas abscesses occurring in 27 patients were seen in Taichung Veterans General Hospital. Their age range was 25 to 85 years. Diabetes mellitus was the leading underlying disease. Fever and pain in the flank area, back and hip were the usual manifestations. The duration of symptoms prior to the diagnosis ranged from 3 days to 6 months. Most abscesses were diagnosed by computed tomography (CT) images and proven by abscess cultures, which were divided into primary and secondary types. Eighteen of 29 abscesses were regarded as primary. Staphylococcus aureus was the most common pathogen in the primary abscesses, followed by Streptococcus agalactiae, Escherichia coli, viridans streptococci, S. epidermidis, and Salmonella spp.. In the secondary abscess category, E. coli was the leading organism in this series, followed by S. aureus, Klebsiella pneumoniae, viridans streptococci and Candida albicans. The associated conditions included epidural abscess, osteomyelitis, septic arthritis, perirenal abscess, pulmonary tuberculosis, empyema, hydronephrosis and trauma history. The initial empiric therapy comprised mostly of cefazolin or oxacillin with or without an aminoglycoside. Thirteen patients underwent percutaneous drainage, while six received surgical debridement, including two with a recurrent abscess. One patient had both drainage and debridement. Others received medical treatment only. Two of the patients with primary abscess died in spite of percutaneous drainage. Therefore, open drainage, besides appropriate antibiotic treatment, is still required to control complex abscesses with sepsis. PMID:10650491

  18. Streptococcus iniae and Streptococcus agalactiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. Extragingival Pyogenic Granuloma: an Unusual Clinical Presentation

    PubMed Central

    Sachdeva, Suresh K.

    2015-01-01

    Pyogenic granuloma is thought to represent an exuberant tissue reaction to local irritation. It occurs in second decade of life in young females. Clinically, oral pyogenic granuloma is a smooth or lobulated exophytic growth, pedunculated or sessile, which usually bleeds on provocation. Oral pyogenic granuloma preferentially affects the gingiva. On rare occasion, it can be found extragingivally on lips, tongue, buccal mucosa, and palate which may mimic more serious pathological conditions such as malignancies. This article reports an unusual case of extra gingival pyogenic granuloma occurring on the right buccal mucosa in a female patient and discusses the features that distinguish this lesion from other similar oral mucosal lesions. PMID:26535410

  20. Huge Pyogenic Granuloma of the Penis

    PubMed Central

    Akbulut, Fatih; Akbulut, Tugba; Kucukdurmaz, Faruk; Sonmezay, Erkan; Simsek, Abdulmuttalip; Gurbuz, Gokhan

    2015-01-01

    Pyogenic granulomas are benign vascular disorders of the skin and mucose membranes, generally developed by trauma and irritation. The lesions are generally small. They are most commonly seen in the skin and oral mucosa and rarely seen on penis. We present the case of a huge pyogenic granuloma on the penis. PMID:26229706

  1. Huge Pyogenic Granuloma of the Penis.

    PubMed

    Akbulut, Fatih; Akbulut, Tugba; Kucukdurmaz, Faruk; Sonmezay, Erkan; Simsek, Abdulmuttalip; Gurbuz, Gokhan

    2015-01-01

    Pyogenic granulomas are benign vascular disorders of the skin and mucose membranes, generally developed by trauma and irritation. The lesions are generally small. They are most commonly seen in the skin and oral mucosa and rarely seen on penis. We present the case of a huge pyogenic granuloma on the penis. PMID:26229706

  2. StreptInCor: A Candidate Vaccine Epitope against S. pyogenes Infections Induces Protection in Outbred Mice

    PubMed Central

    Postol, Edilberto; Alencar, Raquel; Higa, Fabio T.; Freschi de Barros, Samar; Demarchi, Lea M. F.; Kalil, Jorge; Guilherme, Luiza

    2013-01-01

    Infection with Streptococcus pyogenes (S. pyogenes) can result in several diseases, particularly in children. S. pyogenes M protein is the major virulence factor, and certain regions of its N-terminus can trigger autoimmune sequelae such as rheumatic fever in susceptible individuals with untreated group A streptococcal pharyngitis. In a previous study, we utilized a large panel of human peripheral blood cells to define the C-terminal protective epitope StreptInCor (medical identity), which does not induce autoimmune reactions. We recently confirmed the results in HLA-transgenic mice. In the present study, we extended the experimental assays to outbred animals (Swiss mice). Herein, we demonstrate high titers of StreptInCor-specific antibodies, as well as appropriate T-cell immune responses. No cross-reaction to cardiac myosin was detected. Additionally, immunized Swiss mice exhibited 87% survival one month after challenge with S. pyogenes. In conclusion, the data presented herein reinforce previous results in humans and animals and further emphasize that StreptInCor could be an effective and safe vaccine for the prevention of S. pyogenes infections. PMID:23593359

  3. Streptoccocus pyogenes: a forgotten cause of severe community-acquired pneumonia.

    PubMed

    Birch, C; Gowardman, J

    2000-02-01

    We report a case of severe community-acquired pneumonia caused by Streptococcus pyogenes (Lancefield Group A streptoccocus) that was complicated by a streptococcal toxic shock syndrome. Although this micro-organism is an uncommon cause of community-acquired pneumonia, previously well individuals may be infected and the clinical course may be fulminant. A household contact was the likely point of infection. Invasive group A streptococcal disease continues to remain an important cause of morbidity and mortality in the community and therefore will continue to be encountered by intensive care physicians. Treatment of Group A streptococcal infection remains penicillin; however, clindamycin should be added in severe infection. PMID:10701045

  4. Pyogenic liver abscess: uncommon presentation.

    PubMed

    Sotto Mayor, Joana; Robalo, Maria Margarida; Pacheco, Ana Paula; Esperança, Sofia

    2016-01-01

    Pyogenic liver abscess is a rare entity, but it is fatal when untreated. With a peak incidence in the fifth decade of life, its early recognition and intervention are key to successful treatment and better prognosis of patients. In recent years, its approach has been enhanced by the use of percutaneous drainage, improved imaging techniques and a better microbiological characterisation, allowing for a more appropriate use of antibiotics. Clinical manifestations are variable and depend on the size of the abscess, the condition of the patient, associated diseases and possible complications. Among the most common symptoms that stand out are the pain in the upper quadrants of the abdomen, high fever, nausea and vomiting. The authors present the case of a patient who developed an atrial flutter as the initial presentation of a hepatic abscess that imagiologically mimicked a hepatic tumour. PMID:27170608

  5. Pediatric pyogenic granuloma of the glans penis.

    PubMed

    Eickhorst, Kimberly M; Nurzia, Michael J; Barone, Joseph G

    2003-03-01

    Pyogenic granulomas are benign vascular proliferations of the skin and mucous membranes. We present a case report of a 13-year-old uncircumcised boy with phimosis and a pyogenic granuloma of the glans penis. The relationship between these lesions, phimosis, smegma, and circumcision is discussed. When the lesion is found in conjunction with phimosis, consideration should be given for circumcision. Close follow-up to rule out recurrence is necessary. PMID:12639669

  6. 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. PMID:23231486

  7. Acute Mastoiditis Caused by Streptococcus pneumoniae.

    PubMed

    Obringer, Emily; Chen, Judy L

    2016-05-01

    Acute mastoiditis (AM) is a relatively rare complication of acute otitis media (AOM). The most common pathogens include Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus. Pneumococcal vaccination and changes in antibiotic prescribing recommendations for AOM may change the incidence of AM in the future. Diagnosis of AM can be made based on clinical presentation, but computed tomography of the temporal bone with contrast should be considered if there is concern for complicated AM. Both extracranial and intracranial complications of AM may occur. Previously, routine cortical mastoidectomy was recommended for AM treatment, but new data suggest that a more conservative treatment approach can be considered, including intravenous (IV) antibiotics alone or IV antibiotics with myringotomy. [Pediatr Ann. 2016;45(5):e176-e179.]. PMID:27171806

  8. Coaggregation of Streptococcus sanguis and other streptococci with Candida albicans.

    PubMed Central

    Jenkinson, H F; Lala, H C; Shepherd, M G

    1990-01-01

    Thirteen strains of viridans group streptococci and two strains of other streptococci were tested for coaggregation with Candida albicans. Streptococcus sanguis strains generally exhibited low levels of adherence to 28 degrees C-grown exponential-phase yeast cells, but starvation of yeast cells for glucose at 37 degrees C (or at 28 degrees C) increased their coaggregating activity with these streptococci by at least tenfold. This was a property common to four C. albicans strains tested, two of which were able to form mycelia (6406 and MEN) and two of which were not (MM2002 and CA2). The expression of the coaggregation adhesin during yeast cell starvation was inhibited by addition of trichodermin or amphotericin B. The strains of S. sanguis, Streptococcus gordonii, and Streptococcus oralis tested for coaggregating activity encompassed a diverse range of physiological and morphological types, yet all exhibited saturable coaggregation with starved C. albicans cells. There was no correlation of cell surface hydrophobicity, of either yeast or streptococcal cells, with their abilities to coaggregate. Strains of Streptococcus anginosus also coaggregated with starved yeast cells; Streptococcus salivarius and Streptococcus pyogenes coaggregated to a lesser degree with C. albicans, and the coaggregation with S. pyogenes was not promoted by yeast cell starvation; Streptococcus mutans and Enterococcus faecalis did not coaggregate with yeast. The coaggregation reactions of S. sanguis and S. gordonii with C. albicans were inhibited by EDTA and by heat or protease treatment of the yeast cells and were not reversible by the addition of lactose or other simple sugars. These observations extend the range of intergeneric coaggregations that are known to occur between oral microbes and suggest that coaggregations of C. albicans with viridans group streptococci may be important for colonization of oral surfaces by the yeast. PMID:2182544

  9. Streptococcus viridans osteomyelitis with endocarditis presenting as acute onset lower back pain.

    PubMed

    Buchman, A L

    1990-01-01

    An elderly male with a history of diabetes mellitus and a recent dental procedure presented to the emergency department with acute lumbosacral pain and low grade fever. Computerized tomography (CT scan) and magnetic resonance imaging (MRI) yielded a presumptive diagnosis of pyogenic vertebral osteomyelitis. A diagnosis of viridans Streptococcus vertebral osteomyelitis was confirmed by gallium scanning and blood culture. The literature has emphasized the occurrence of pyogenic vertebral osteomyelitis as a chronic process. A review suggests that viridans Streptococci, although an uncommon cause of this disorder, is usually associated with back pain of more acute onset. It is therefore recommended that pyogenic vertebral osteomyelitis be considered in any patient presenting to the emergency department with the acute onset of lower back pain, fever, leukocytosis and an elevated erythrocyte sedimentation rate. PMID:2142706

  10. 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. PMID:21310787

  11. mefE is necessary for the erythromycin-resistant M phenotype in Streptococcus pneumoniae.

    PubMed Central

    Tait-Kamradt, A; Clancy, J; Cronan, M; Dib-Hajj, F; Wondrack, L; Yuan, W; Sutcliffe, J

    1997-01-01

    Recently, it was shown that a significant number of erythromycin-resistant Streptococcus pneumoniae and Streptococcus pyogenes strains contain a determinant that mediates resistance via a putative efflux pump. The gene encoding the erythromycin-resistant determinant was cloned and sequenced from three strains of S. pneumoniae bearing the M phenotype (macrolide resistant but clindamycin and streptogramin B susceptible). The DNA sequences of mefE were nearly identical, with only 2-nucleotide differences between genes from any two strains. When the mefE sequences were compared to the mefA sequence from S. pyogenes, the two genes were found to be closely related (90% identity). Strains of S. pneumoniae were constructed to confirm that mefE is necessary to confer erythromycin resistance and to explore the substrate specificity of the pump; no substrates other than 14- and 15-membered macrolides were identified. PMID:9333056

  12. Primary pyogenic abscess of the psoas muscle.

    PubMed

    Wu, T L; Huang, C H; Hwang, D Y; Lai, J H; Su, R Y

    1998-01-01

    During a six-year period, eleven persons with primary pyogenic abscess of the psoas muscle were treated at the Mackay Memorial Hospital. Five were males and six were females and their average age was 47.2 years (range 6-83 years). The abscess was identified by CT in 7 patients, MRI in 2 and ultrasonography in 1. One abscess was found during laparotomy. Treatment included extraperitoneal drainage of the abscess in 7 patients and CT guided aspiration in 3. One patient improved after antibiotic therapy and they all recovered after treatment. The diagnosis of primary pyogenic abscess requires a high index of suspicion and the best treatment is early operative drainage and administration of systemic antibiotics. PMID:9549580

  13. Pyogenic Vertebral Osteomyelitis in Heroin Addicts

    PubMed Central

    Fishbach, Ronald S.; Rosenblatt, Jon E.; Dahlgren, James G.

    1973-01-01

    The diagnosis of pyogenic vertebral osteomyelitis was made in seven narcotic addicts between 1967 and 1972. Vertebrae involved were either cervical or lumbar. Bacteriologic diagnosis was made in each case by percutaneous needle biopsy and aspiration. Staphylococcus aureus was cultured in two patients. Five patients had infections due to Gram-negative bacteria, including Klebsiella pneumoniae, Pseudomonas aeruginosa and Enterobacter. All patients were cured by treatment with antibiotics and immobilization. PMID:4199351

  14. Angioleiomyoma of Gingiva Masquerading as Pyogenic Granuloma.

    PubMed

    Bajpai, Manas; Pardhe, Nilesh; Kumar, Manish

    2016-07-01

    Leiomyomas are benign soft tissue neoplasms that arise from smooth muscles. Three distinctive patterns of leiomyoma have been described as piloleiomyomas, angioleiomyomas and genital leiomyomas. Here in, we report the case of 39-year male with chief complain of growth on his lower left front region of the jaw. On the basis of clinical examination, it was provisionally diagnosed as pyogenic granuloma; however, histopathological examination made to the final diagnosis of angioleiomyoma. Excision led to uneventful recovery. PMID:27504561

  15. Spectroscopic Method for Fast and Accurate Group A Streptococcus Bacteria Detection.

    PubMed

    Schiff, Dillon; Aviv, Hagit; Rosenbaum, Efraim; Tischler, Yaakov R

    2016-02-16

    Rapid and accurate detection of pathogens is paramount to human health. Spectroscopic techniques have been shown to be viable methods for detecting various pathogens. Enhanced methods of Raman spectroscopy can discriminate unique bacterial signatures; however, many of these require precise conditions and do not have in vivo replicability. Common biological detection methods such as rapid antigen detection tests have high specificity but do not have high sensitivity. Here we developed a new method of bacteria detection that is both highly specific and highly sensitive by combining the specificity of antibody staining and the sensitivity of spectroscopic characterization. Bacteria samples, treated with a fluorescent antibody complex specific to Streptococcus pyogenes, were volumetrically normalized according to their Raman bacterial signal intensity and characterized for fluorescence, eliciting a positive result for samples containing Streptococcus pyogenes and a negative result for those without. The normalized fluorescence intensity of the Streptococcus pyogenes gave a signal that is up to 16.4 times higher than that of other bacteria samples for bacteria stained in solution and up to 12.7 times higher in solid state. This method can be very easily replicated for other bacteria species using suitable antibody-dye complexes. In addition, this method shows viability for in vivo detection as it requires minute amounts of bacteria, low laser excitation power, and short integration times in order to achieve high signal. PMID:26752013

  16. Molecular phylogeny and a taxonomic proposal for the genus Streptococcus.

    PubMed

    Póntigo, F; Moraga, M; Flores, S V

    2015-01-01

    Alternative phylogenies for the genus Streptococcus have been proposed due to uncertainty about the among-species group relationships. Here, we performed a phylogenetic analysis of the genus Streptococcus, considering all the species groups and also the genomic data accumulated by other studies. Seventy-five species were subjected to a Bayesian phylogenetic analysis using sequences from eight genes (16S rRNA, rpoB, sodA, tuf, rnpB, gyrB, dnaJ, and recN). On the basis of our results, we propose a new Phylogeny for the genus, with special emphasis on the inter-species group level. This new phylogeny differs from those suggested previously. From topological and evolutionary distance criteria, we propose that gordonii, pluranimalium, and sobrinus should be considered as new species groups, in addition to the currently recognized groups of mutans, bovis, pyogenic, suis, mitis, and salivarius. PMID:26400318

  17. The conservative management of acute pyogenic iliopsoas abscess in children.

    PubMed

    Tong, C W; Griffith, J F; Lam, T P; Cheng, J C

    1998-01-01

    We describe three cases of acute pyogenic abscess of the iliopsoas in children treated conservatively. Two patients had image-guided aspiration and one was managed with antibiotics alone. All made a complete recovery. Acute pyogenic abscess of the iliopsoas in children can be treated effectively and safely with intravenous antibiotics and image-guided aspiration of the abscess. PMID:9460958

  18. CT in pyogenic osteomyelitis of the spine

    SciTech Connect

    Kattapuram, S.V.; Phillips, W.C.; Boyd, R.

    1983-06-01

    Six patients with bacteriologically proven pyogenic osteomyelitis of the spine were followed serially with computed tomography (CT). Initial evaluation of the involved vertebral bodies and adjacent soft tissues showed a drop in CT numbers when compared to normal cancellous bone and soft tissues. A soft-tissue mass was seen in all cases. After appropriate antibiotic therapy, all six patients showed an increase in bone density and a diminution of the soft-tissue mass (p < 0.05). Five of the six patients showed a further decrease in soft-tissue CT numbers.

  19. [Toxic shock syndrome by group A beta-hemolytic streptococcus. Study of clonal relationship between a case and its contacts].

    PubMed

    Fernández, J; Fica, A; Caorsi, B; Contreras, J; Luppi, M; Heitmann, I

    1998-08-01

    Group A Streptococcal infections have increased in severity and frequency worldwide. We report a female patient that was admitted by Group A Streptococcal lethal toxic shock syndrome due to pharyngitis as the primary focus and without cutaneous involvement. Streptococcus pyogenes was isolated from blood cultures and case definition fulfilled standard recommendations. Epidemiological studies among family members showed, that two children (aged 5 and 12 years) harbored the same strain in their pharynxes as confirmed by arbitrarily primed PCR (AP-PCR) using primers ERIC and Pn-1. Control strains were included in the analysis. None of three health care workers involved in intubation and laryngoscopic procedures with the patient carried S pyogenes. AP-PCR appears to be a useful and rapid procedure to demonstrate clonal relatedness among S pyogenes strains. PMID:9830749

  20. Pyogenic liver abscess: Changing patterns in approach

    PubMed Central

    Malik, Ajaz A; Bari, Shams UL; Rouf, Khawaja Abdul; Wani, Khurshid Alam

    2010-01-01

    AIM: To define optimum management of the pyogenic liver abscess and assess new trends in treatment. METHODS: One hundred and sixty nine patients with pyogenic liver abscess managed at Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Kashmir (India) from July 2001 to August 2006 were studied to evaluate and define the optimum treatment. RESULTS: Mortality in the surgically treated group of patients was 9.4% (12/119), while those treated non-surgically had a fatality rate of 16.66% (7/42). Multiple liver abscesses treated surgically had a surprisingly low mortality of 30%. The biliary tract (64.97%) was the most common cause of liver abscess. Multiple abscesses, mixed organisms and abscess complications are all associated with a significantly increased mortality. However, the lethality of the primary disease process was the most important factor in determining survival. CONCLUSION: Transperitoneal surgical drainage and antibiotics are the mainstay of treatment. Percutaneous drainage is recommended for high risk patients only. PMID:21206721

  1. An unusual case of Streptococcus anginosus group pyomyositis diagnosed using direct 16S ribosomal DNA sequencing

    PubMed Central

    Walkty, Andrew; Embil, John M; Nichol, Kim; Karlowsky, James

    2014-01-01

    Bacteria belonging to the Streptococcus anginosus group (Streptococcus intermedius, Streptococcus constellatus and Streptococcus anginosus) are capable of causing serious pyogenic infections, with a tendency for abscess formation. The present article reports a case of S anginosus group pyomyositis in a 47-year-old man. The pathogen was recovered from one of two blood cultures obtained from the patient, but speciation was initially not performed because the organism was considered to be a contaminant (viridans streptococci group). The diagnosis was ultimately confirmed using 16S ribosomal DNA sequencing of purulent fluid obtained from a muscle abscess aspirate. The present case serves to emphasize that finding even a single positive blood culture of an organism belonging to the S anginosus group should prompt careful evaluation of the patient for a pyogenic focus of infection. It also highlights the potential utility of 16S ribosomal DNA amplification and sequencing in direct pathogen detection from aspirated fluid in cases of pyomyositis in which antimicrobial therapy was initiated before specimen collection. PMID:24634686

  2. Application of immunoproteomics to analysis of post-translational processing of the antiphagocytic M protein of Streptococcus.

    PubMed

    Romer, Terence G; Boyle, Michael D P

    2003-01-01

    Post-translational modification of the antiphagocytic M1 protein of Streptococcus pyogenes can influence its binding properties for human immunoglobulin G subclasses and its invasive potential. Current methods of monitoring this modification event involve N-terminal sequencing and are cumbersome, slow and not amenable to routine analysis. In this study we demonstrate that surface enhanced laser desorption/ionization-time of flight mass spectrometry can be used to monitor modification of the M1 protein by the secreted bacterial cysteine protease, SpeB. This method, when combined with a specific antibody capture step provides a specific, rapid and sensitive assay for key virulence factors of the important human pathogen Streptococcus pyogenes. PMID:12548631

  3. Two cases of giant pyogenic granuloma of scalp

    PubMed Central

    Chandra, B. Satish; Rao, P. Narasimha

    2013-01-01

    Pyogenic granuloma is a benign vascular tumor of unknown etiology, though multiple factors play a role in its onset, e.g., trauma, chronic irritation, drugs etc., It is commonly seen in children and adolescents. Giant pyogenic granuloma is its atypical variant. We are presenting two cases of giant pyogenic granuloma, one, in a 28-year-old adult, presenting as a giant fluffy swelling of scalp and the other in a 11-year-old child, presenting as a giant ulcerated globular swelling of the scalp. PMID:24350008

  4. [The Corynebacterium pyogenes infection of cattle. 2. Tenacity of Corynebacterium pyogenes].

    PubMed

    Nattermann, H; Horsch, F

    1977-01-01

    Some common agents were tested for their effectiveness against Corynebacterium pyogenes. The pathogen proved most susceptable to Wofasteril. All germs were killed within ten minutes by a 0.005% solution. Equally good action was recorded from all the other tested agents as well (lactic acid, Lugol's solution, formalin, cupric sulphate, alcohol, and aethacridine. Other studies were conducted with the view to testing the survival capacity of Corynebacterium pyogenes in different media and storage conditions. The pathogen survived three months in routine media and mastitis secretion at room temperature. Regrowth of 38 in 50 strains took place after nine months of refrigerator storage in slanting blood agar tubes with paraffin plugs. Germs sampled from mastitis secretion and stored in a refrigerator were cultivable even after one year had elapsed. The detectability rate of Corynebacterium pyogenes did not change over months by storage of wound infection material at 12 degrees C below zero. The pathogen remained detectable five days from artificial contamination of cattle skin. PMID:336001

  5. Novel Twin Streptolysin S-Like Peptides Encoded in the sag Operon Homologue of Beta-Hemolytic Streptococcus anginosus

    PubMed Central

    Tabata, Atsushi; Nakano, Kota; Ohkura, Kazuto; Tomoyasu, Toshifumi; Kikuchi, Ken; Whiley, Robert A.

    2013-01-01

    Streptococcus anginosus is a member of the anginosus group streptococci, which form part of the normal human oral flora. In contrast to the pyogenic group streptococci, our knowledge of the virulence factors of the anginosus group streptococci, including S. anginosus, is not sufficient to allow a clear understanding of the basis of their pathogenicity. Generally, hemolysins are thought to be important virulence factors in streptococcal infections. In the present study, a sag operon homologue was shown to be responsible for beta-hemolysis in S. anginosus strains by random gene knockout. Interestingly, contrary to pyogenic group streptococci, beta-hemolytic S. anginosus was shown to have two tandem sagA homologues, encoding streptolysin S (SLS)-like peptides, in the sag operon homologue. Gene deletion and complementation experiments revealed that both genes were functional, and these SLS-like peptides were essential for beta-hemolysis in beta-hemolytic S. anginosus. Furthermore, the amino acid sequence of these SLS-like peptides differed from that of the typical SLS of S. pyogenes, especially in their propeptide domain, and an amino acid residue indicated to be important for the cytolytic activity of SLS in S. pyogenes was deleted in both S. anginosus homologues. These data suggest that SLS-like peptides encoded by two sagA homologues in beta-hemolytic S. anginosus may be potential virulence factors with a different structure essential for hemolytic activity and/or the maturation process compared to the typical SLS present in pyogenic group streptococci. PMID:23292771

  6. Pyogenic Flexor Tenosynovitis Caused by Shewanella algae.

    PubMed

    Fluke, Erin C; Carayannopoulos, Nikoletta L; Lindsey, Ronald W

    2016-07-01

    Pyogenic flexor tenosynovitis is an orthopedic emergency most commonly caused by Staphylococcus aureus and streptococci and occasionally, when associated with water exposure, Mycobacterium marinum. Shewanella algae, a gram-negative bacillus found in warm saltwater environments, has infrequently been reported to cause serious soft tissue infections and necrosis. In this case, S. algae caused complicated flexor tenosynovitis requiring open surgical irrigation and debridement. Flexor tenosynovitis caused by S. algae rapidly presented with all 4 Kanavel cardinal signs as well as subcutaneous purulence, ischemia, and necrosis, thus meeting the requirements for Pang et al group III classification of worst prognosis. Because of its rarity and virulence, S. algae should always be considered in cases of flexor tenosynovitis associated with traumatic water exposure to treat and minimize morbidity appropriately. PMID:27206398

  7. Primary pyogenic psoas abscess in children.

    PubMed

    Kadambari, D; Jagdish, S

    2000-01-01

    Primary pyogenic psoas abscess, although quite a common condition, particularly in the tropics, is often overlooked as a clinical entity, probably because a psoas abscess has been traditionally associated with tuberculous spondylitis. The abscess is easily diagnosed by ultrasonography (US). Treatment by open drainage and antibiotics effective against Staphylococcus aureus results in complete reversal of symptoms and signs. In our series of 55 cases in the pediatric age group (0-12 years), pain and flexion at the hip were the most frequent clinical features at presentation. US was diagnostic in all cases in which it was performed. All except 1 patient showed complete resolution with extraperitoneal drainage, antibiotics, and skin traction. Although 4% of the cases were associated with suppurative external-iliac lymphadenitis, the remaining ones arose de novo in the psoas sheath, suggesting a primary pyomyositis of the psoas muscle. PMID:10955575

  8. Pyogenic Granuloma on the Upper Labial Mucosa: A Case Report

    PubMed Central

    K A, Kamala; Ashok, L.; G P, Sujatha

    2013-01-01

    Pyogenic granuloma is thought to represent an exuberant tissue response to a local irritation or trauma. It is a reactional response to constant minor trauma and it might be related to hormonal changes. Clinically, these lesions usually present as single nodules or sessile papules with smooth or lobulated surfaces. These may be seen in any size, from a few millimetres to several centimetres. Pyogenic granuloma of the oral cavity is known to involve the gingiva more commonly (75% of all the cases). An extragingival occurrence of pyogenic granuloma is rare. This paper has described an extragingival pyogenic granuloma which occurred on the upper labial mucosa in a 30 years old female patient. PMID:23905151

  9. Atypical location of pyogenic granuloma in two pediatric patients.

    PubMed

    de Souza, Alice Granthon; da Silva, Bruna Cunha; Israel, Monica Simoes; Lindenblatt, Rhayany; de Andrade, Ana Maria; Ramos, Maria Eliza

    2008-01-01

    Pyogenic granuloma is a reactional lesion that is associated with dental calculi or trauma. It occurs most frequently in children and young adults, where the gingiva is affected most commonly. Its differential diagnosis is based on histopathological findings and treatment consists of surgical removal and elimination of the irritating factor. This article presents two cases of pyogenic granuloma in pediatric patients and explains the treatment methods used in each case. PMID:18683402

  10. Brachial Plexus Neuritis Associated With Streptococcus agalactiae Infection: A Case Report.

    PubMed

    Seo, Yu Jung; Lee, Yu Jin; Kim, Joon Sung; Lim, Seong Hoon; Hong, Bo Young

    2014-08-01

    Brachial plexus neuritis is reportedly caused by various factors; however, it has not been described in association with Streptococcus agalactiae. This is a case report of a patient diagnosed with brachial plexus neuritis associated with pyogenic arthritis of the shoulder. A 57-year-old man visited the hospital complaining of sudden weakness and painful swelling of the left arm. The diagnosis was pyogenic arthritis of the left shoulder, and the patient was treated with open irrigation and debridement accompanied by intravenous antibiotic therapy. S. agalactiae was isolated from a wound culture, and an electrodiagnostic study showed brachial plexopathy involving the left upper and middle trunk. Nine weeks after onset, muscle strength improved in most of the affected muscles, and an electrodiagnostic study showed signs of reinnervation. In conclusion, S. agalactiae infection can lead to various complications including brachial plexus neuritis. PMID:25229037

  11. Brachial Plexus Neuritis Associated With Streptococcus agalactiae Infection: A Case Report

    PubMed Central

    Seo, Yu Jung; Lee, Yu Jin; Kim, Joon Sung; Lim, Seong Hoon

    2014-01-01

    Brachial plexus neuritis is reportedly caused by various factors; however, it has not been described in association with Streptococcus agalactiae. This is a case report of a patient diagnosed with brachial plexus neuritis associated with pyogenic arthritis of the shoulder. A 57-year-old man visited the hospital complaining of sudden weakness and painful swelling of the left arm. The diagnosis was pyogenic arthritis of the left shoulder, and the patient was treated with open irrigation and debridement accompanied by intravenous antibiotic therapy. S. agalactiae was isolated from a wound culture, and an electrodiagnostic study showed brachial plexopathy involving the left upper and middle trunk. Nine weeks after onset, muscle strength improved in most of the affected muscles, and an electrodiagnostic study showed signs of reinnervation. In conclusion, S. agalactiae infection can lead to various complications including brachial plexus neuritis. PMID:25229037

  12. Isolation of gram-positive rods that resemble but are clearly distinct from Actinomyces pyogenes from mixed wound infections.

    PubMed Central

    Wüst, J; Lucchini, G M; Lüthy-Hottenstein, J; Brun, F; Altwegg, M

    1993-01-01

    Beginning in 1990, gram-positive rods resembling Actinomyces pyogenes were found with increasing frequency in mixed cultures from various infectious processes, most of them from patients with otitis, empyema, pilonidal cysts, perianal abscesses, and decubitus ulcers. Ribotyping and hybridization showed that these gram-positive rods could be divided into five groups not related to known Actinomyces species. Biochemical markers for reliable differentiation into these groups, however, could not be found. Therefore, naming new species is not warranted unless parameters are discovered that allow identification without DNA hybridization. These gram-positive rods have been isolated only in mixed cultures with anaerobes, Staphylococcus aureus, Streptococcus "milleri," enterococci, and gram-negative rods. Their exact role in these possibly synergistic infections needs further investigation. Images PMID:8501213

  13. Appendectomy correlates with increased risk of pyogenic liver abscess

    PubMed Central

    Liao, Kuan-Fu; Lai, Shih-Wei; Lin, Cheng-Li; Chien, Sou-Hsin

    2016-01-01

    Abstract Little is known on the association between appendectomy and pyogenic liver abscess. The objective of this study was to investigate the association between appendectomy and the risk of pyogenic liver abscess in Taiwan. This population-based retrospective cohort study was conducted using the hospitalization dataset of the Taiwan National Health Insurance Program. There were 212,530 subjects age 20 to 84 years with newly diagnosed appendectomy as the appendectomy group since 1998 to 2010, and 850,099 randomly selected subjects without appendectomy as the nonappendectomy group. Both appendectomy and nonappendectomy groups were matched with sex, age, comorbidities, and index year of diagnosing appendectomy. The incidence of pyogenic liver abscess at the end of 2011 was estimated in both groups. The multivariable Cox proportional hazards regression model was applied to investigate the hazard ratio (HR) and 95% confidence interval (CI) for risk of pyogenic liver abscess associated with appendectomy and other comorbidities including alcoholism, biliary stone, chronic kidney disease, chronic liver diseases, and diabetes mellitus. The overall incidence of pyogenic liver abscess was 1.73-fold greater in the appendectomy group than that in the nonappendectomy group (3.85 vs 2.22 per 10,000 person-years, 95% CI 1.71, 1.76). The multivariable regression analysis disclosed that the adjusted HR of pyogenic liver abscess was 1.77 for the appendectomy group (95% CI 1.59, 1.97), when compared with the nonappendectomy group. Appendectomy is associated with increased hazard of pyogenic liver abscess. Further studies remain necessary to confirm our findings. PMID:27368018

  14. 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

  15. Evidence for niche adaptation in the genome of the bovine pathogen Streptococcus uberis

    PubMed Central

    Ward, Philip N; Holden, Matthew TG; Leigh, James A; Lennard, Nicola; Bignell, Alexandra; Barron, Andy; Clark, Louise; Quail, Michael A; Woodward, John; Barrell, Bart G; Egan, Sharon A; Field, Terence R; Maskell, Duncan; Kehoe, Michael; Dowson, Christopher G; Chanter, Neil; Whatmore, Adrian M; Bentley, Stephen D; Parkhill, Julian

    2009-01-01

    Background Streptococcus uberis, a Gram positive bacterial pathogen responsible for a significant proportion of bovine mastitis in commercial dairy herds, colonises multiple body sites of the cow including the gut, genital tract and mammary gland. Comparative analysis of the complete genome sequence of S. uberis strain 0140J was undertaken to help elucidate the biology of this effective bovine pathogen. Results The genome revealed 1,825 predicted coding sequences (CDSs) of which 62 were identified as pseudogenes or gene fragments. Comparisons with related pyogenic streptococci identified a conserved core (40%) of orthologous CDSs. Intriguingly, S. uberis 0140J displayed a lower number of mobile genetic elements when compared with other pyogenic streptococci, however bacteriophage-derived islands and a putative genomic island were identified. Comparative genomics analysis revealed most similarity to the genomes of Streptococcus agalactiae and Streptococcus equi subsp. zooepidemicus. In contrast, streptococcal orthologs were not identified for 11% of the CDSs, indicating either unique retention of ancestral sequence, or acquisition of sequence from alternative sources. Functions including transport, catabolism, regulation and CDSs encoding cell envelope proteins were over-represented in this unique gene set; a limited array of putative virulence CDSs were identified. Conclusion S. uberis utilises nutritional flexibility derived from a diversity of metabolic options to successfully occupy a discrete ecological niche. The features observed in S. uberis are strongly suggestive of an opportunistic pathogen adapted to challenging and changing environmental parameters. PMID:19175920

  16. Evolution of the core and pan-genome of Streptococcus: positive selection, recombination, and genome composition

    PubMed Central

    Lefébure, Tristan; Stanhope, Michael J

    2007-01-01

    Background The genus Streptococcus is one of the most diverse and important human and agricultural pathogens. This study employs comparative evolutionary analyses of 26 Streptococcus genomes to yield an improved understanding of the relative roles of recombination and positive selection in pathogen adaptation to their hosts. Results Streptococcus genomes exhibit extreme levels of evolutionary plasticity, with high levels of gene gain and loss during species and strain evolution. S. agalactiae has a large pan-genome, with little recombination in its core-genome, while S. pyogenes has a smaller pan-genome and much more recombination of its core-genome, perhaps reflecting the greater habitat, and gene pool, diversity for S. agalactiae compared to S. pyogenes. Core-genome recombination was evident in all lineages (18% to 37% of the core-genome judged to be recombinant), while positive selection was mainly observed during species differentiation (from 11% to 34% of the core-genome). Positive selection pressure was unevenly distributed across lineages and biochemical main role categories. S. suis was the lineage with the greatest level of positive selection pressure, the largest number of unique loci selected, and the largest amount of gene gain and loss. Conclusion Recombination is an important evolutionary force in shaping Streptococcus genomes, not only in the acquisition of significant portions of the genome as lineage specific loci, but also in facilitating rapid evolution of the core-genome. Positive selection, although undoubtedly a slower process, has nonetheless played an important role in adaptation of the core-genome of different Streptococcus species to different hosts. PMID:17475002

  17. Genetic Relationships Deduced from emm and Multilocus Sequence Typing of Invasive Streptococcus dysgalactiae subsp. equisimilis and S. canis Recovered from Isolates Collected in the United States ▿

    PubMed Central

    Ahmad, Yusra; Gertz, Robert E.; Li, Zhongya; Sakota, Varja; Broyles, Laura N.; Van Beneden, Chris; Facklam, Richard; Shewmaker, P. Lynn; Reingold, Arthur; Farley, Monica M.; Beall, Bernard W.

    2009-01-01

    Beta-hemolytic group C and G streptococci cause a considerable invasive disease burden and sometimes cause disease outbreaks. Little is known about the critical epidemiologic parameter of genetic relatedness between isolates. We determined the emm types of 334 Streptococcus dysgalactiae subsp. equisimilis isolates, and attempted emm typing of 5 Streptococcus canis isolates from a recent population-based surveillance for invasive isolates. Thirty-four emm types were observed, including one from S. canis. We formulated multilocus sequence typing (MLST) primers with six of the seven loci corresponding to the Streptococcus pyogenes MLST scheme. We performed MLST with 65 of the 334 surveillance isolates (61 S. dysgalactiae subsp. equisimilis isolates, 4 S. canis isolates) to represent each emm type identified, including 2 to 3 isolates for each of the 25 redundantly represented emm types. Forty-one MLST sequence types (STs) were observed. Isolates within 16 redundantly represented S. dysgalactiae subsp. equisimilis emm types shared identical or nearly identical STs, demonstrating concordance between the emm type and genetic relatedness. However, seven STs were each represented by two to four different emm types, and 7 of the 10 S. dysgalactiae subsp. equisimilis eBURST groups represented up to six different emm types. Thus, S. dysgalactiae subsp. equisimilis isolates were similar to S. pyogenes isolates, in that strains of the same emm type were often highly related, but they differed from S. pyogenes, in that S. dysgalactiae subsp. equisimilis strains with identical or closely similar STs often exhibited multiple unrelated emm types. The phylogenetic relationships between S. dysgalactiae subsp. equisimilis and S. pyogenes alleles revealed a history of interspecies recombination, with either species often serving as genetic donors. The four S. canis isolates shared highly homologous alleles but were unrelated clones without evidence of past recombination with S

  18. [Angiolymphoid hyperplasia with eosinophilia. The spectrum from Kimura disease to atypical pyogenic granuloma].

    PubMed

    Wustrow, A; Mahrle, G

    1987-04-15

    A patient showed the "atypical pyogenic granuloma" of the head in combination with atopic dermatitis and proceeding pyogenic granuloma of the back. The diagnostic aspects of angiolymphoid hyperplasia with eosinophilia (ALHE) including Kimura's disease, subcutaneous ALHE, and atypical pyogenic granuloma are discussed. PMID:3111112

  19. "Pyogenic granuloma - Hyperplastic lesion of the gingiva: case reports".

    PubMed

    Verma, Pushpendra Kumar; Srivastava, Ruchi; Baranwal, H C; Chaturvedi, T P; Gautam, Anju; Singh, Amit

    2012-01-01

    Pyogenic granuloma is a reactive hyperplasia of connective tissue in response to local irritants. It is a tumourlike growth of the oral cavity, frequently located surrounding the anterior teeth or skin that is considered to be neoplastic in nature. It usually arises in response to various stimuli such as low-grade local irritation, traumatic injury, hormonal factors, or certain kinds of drugs. Histologically, the surface epithelium may be intact, or may show foci of ulcerations or even exhibiting hyperkeratosis. It overlies a mass of dense connective tissue composed of significant amounts of mature collagen. Gingiva is the most common site affected followed by buccal mucosa, tongue and lips. Pyogenic granuloma in general, does not occur when excised along with the base and its causative factors. This paper presents some cases of a pyogenic granuloma managed by surgical intervention. PMID:23091574

  20. Additional tests to differentiate Arcanobacterium haemolyticum and Actinomyces pyogenes.

    PubMed

    Carlson, P; Eerola, E; Kontiainen, S

    1995-04-01

    A commercially available biochemical test panel, commercially available diagnostic tablets and gas-liquid chromatography (GLC) of cellular fatty acids were used to find out whether Arcanobacterium haemolyticum and Actinomyces pyogenes could be further differentiated from each other. Xylitol and alpha-methyl-D-glucoside fermentation, Voges-Proskauer reaction and tributyrate hydrolysis were found to be useful additional tests which differentiated Arc. haemolyticum and A. pyogenes. GLC analysis revealed major differences in the cellular 16:0, 18:2(9,12) and 18:1(9) fatty acid composition of the two species. Especially the Voges-Proskauer test available as diagnostic tablets can be easily performed in clinical microbiology laboratories, in addition to the tests now used to differentiate Arc. haemolyticum from A. pyogenes. PMID:7549154

  1. Insight into the evolution of the histidine triad protein (HTP) family in Streptococcus.

    PubMed

    Shao, Zhu-Qing; Zhang, Yan-Mei; Pan, Xiu-Zhen; Wang, Bin; Chen, Jian-Qun

    2013-01-01

    The Histidine Triad Proteins (HTPs), also known as Pht proteins in Streptococcus pneumoniae, constitute a family of surface-exposed proteins that exist in many pathogenic streptococcal species. Although many studies have revealed the importance of HTPs in streptococcal physiology and pathogenicity, little is known about their origin and evolution. In this study, after identifying all htp homologs from 105 streptococcal genomes representing 38 different species/subspecies, we analyzed their domain structures, positions in genome, and most importantly, their evolutionary histories. By further projecting this information onto the streptococcal phylogeny, we made several major findings. First, htp genes originated earlier than the Streptococcus genus and gene-loss events have occurred among three streptococcal groups, resulting in the absence of the htp gene in the Bovis, Mutans and Salivarius groups. Second, the copy number of htp genes in other groups of Streptococcus is variable, ranging from one to four functional copies. Third, both phylogenetic evidence and domain structure analyses support the division of two htp subfamilies, designated as htp I and htp II. Although present mainly in the pyogenic group and in Streptococcus suis, htp II members are distinct from htp I due to the presence of an additional leucine-rich-repeat domain at the C-terminus. Finally, htp genes exhibit a faster nucleotide substitution rate than do housekeeping genes. Specifically, the regions outside the HTP domains are under strong positive selection. This distinct evolutionary pattern likely helped Streptococcus to easily escape from recognition by host immunity. PMID:23527301

  2. Necrotizing fasciitis of the retroperitoneum: an unusual presentation of group A Streptococcus infection.

    PubMed

    Devin, B; McCarthy, A; Mehran, R; Auger, C

    1998-04-01

    A 14-year-old girl presented with symptoms resembling acute appendicitis. Five days after appendectomy and continued fever and severe abdominal pain, blood cultures were found positive for Streptococcus pyogenes. Two days later a diagnosis of group A streptococcal peritonitis with necrotizing retroperitoneal fasciitis was confirmed by retroperitoneal cultures obtained at laparotomy. Although multiple organ systems showed impaired functioning, including hepatic, renal and respiratory changes, she did not meet the criteria for streptococcal toxic shock syndrome. She was treated with a combination of high-dose parenteral penicillin and clindamycin, followed by prolonged treatment with clindamycin orally. Recovery was complicated by persistent hydronephrosis, which was slow to resolve. PMID:9576000

  3. Streptococcus milleri and Recurrent Intra-Abdominal Abscesses: A Case Report and Literature Review

    PubMed Central

    Gana, Tabitha M.; Awolaran, Olugbenga; Akhtar, Sobia

    2016-01-01

    We report a case of recurrent intra-abdominal abscesses as a postoperative complication following diverticular perforation in which Streptococcus milleri (SM) was isolated. SM is evaluated here as a potent pyogenic organism commonly associated with intra-abdominal abscess especially in the postoperative setting. With the commonly adopted conservative management, the challenges of recurrence and prolonged hospital stay experienced in the indexed case as well as many other previous reports are highlighted. We also present a recommendation of the need for a more intensive approach of SM-related abscess drainage along with areas that would benefit further research. PMID:27313942

  4. Streptococcus suis infection in swine. A sixteen month study.

    PubMed

    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

  5. An Unusual Cause of Flexor Tenosynovitis: Streptococcus mitis

    PubMed Central

    Ulucay, Cağatay; Ozler, Turhan

    2014-01-01

    Summary: Streptococcus mitis is a commensal organism of the human oropharynx that rarely causes infection in healthy individuals. Herein, we describe a previously healthy 35-year-old woman who presented with acute pyogenic flexor tenosynovitis of the left index finger due to S. mitis infection. The patient’s infection was treated successfully via surgical and medical interventions, and during follow-up, it was determined that she was complement component C3 deficient. Tenosynovitis is an emergent clinical syndrome that can result in permanent disability or amputation. To the best of our knowledge, this case report is the first to describe tenosynovitis due to S. mitis; in addition, it highlights the importance of initiating therapy with antibiotics that are effective against this rare pathogen. PMID:25587497

  6. Minimally invasive approach to eliminate pyogenic granuloma: a case report.

    PubMed

    Chandrashekar, B

    2012-01-01

    Pyogenic granuloma is one of the inflammatory hyperplasia seen in the oral cavity. The term is a misnomer because it is not related to infection and arises in response to various stimuli such as low-grade local irritation, traumatic injury, or hormonal factors. It is most commonly seen in females in their second decade of life due to vascular effects of hormones. Although excisional surgery is the treatment of choice for it, this paper presents the safest and most minimally invasive procedure for the regression of pyogenic granuloma. PMID:22567459

  7. Trauma-Induced Giant Pyogenic Granuloma in the Upper Lip.

    PubMed

    de Carvalho, Fabrício Kitazono; Pinheiro, Tiago Novaes; Arid, Juliana; de Queiroz, Alexandra Mussolino; de Rossi, Andiara; Nelson-Filho, Paulo

    2015-01-01

    Pyogenic granuloma (PG) is a reactive local benign vascular lesion, where connective tissue fibrovascular proliferation occurs. The most common etiology of PG is chronic, low-level irritation. PG affects females mainly. The purpose of this paper is to report a giant pyogenic granuloma caused by an acute trauma in the upper lip of an 11-year-old boy. The initial clinical diagnosis suggested PG, which was confirmed after an excisional biopsy and a microscopic exam. Oral lesions of large proportions in children can cause functional, esthetic, and behavioral issues, and should be promptly investigated. PMID:26731254

  8. Pyogenic liver abscess: Differences in etiology and treatment in Southeast Asia and Central Europe

    PubMed Central

    Cerwenka, Herwig

    2010-01-01

    Knowledge of etiology and timely treatment of underlying causes, when possible, play an important role in the successful therapy of patients with pyogenic liver abscess (PLA). Recent publications from Central Europe and Southeast Asia hint at considerable differences in etiology. In this article, we aim to elaborate these differences and their therapeutic implications. Apart from some special types of PLA that are comparable in Southeast Asia and Central Europe (such as posttraumatic or postprocedural PLA), there are clear differences in the microbiological spectrum, which implies different risk factors and disease courses. Klebsiella pneumoniae (K. pneumoniae) PLA is predominantly seen in Southeast Asia, whereas, in Central Europe, PLA is typically caused by Escherichia coli, Streptococcus or Staphylococcus, and these patients are more likely to be older and to have a biliary abnormality or malignancy. K. pneumoniae patients are more likely to have diabetes mellitus. Control of septic spread is crucial in K. pneumoniae patients, whereas treatment of the underlying diseases is decisive in many Central European PLA patients. PMID:20503444

  9. Identification of macrolide-resistant clones of Streptococcus pyogenes in Portugal.

    PubMed

    Silva-Costa, C; Ramirez, M; Melo-Cristino, J

    2006-06-01

    Although the overall level of macrolide resistance (27%) has remained stable in Portugal, a rapid inversion in the dominant phenotypes has been noted, with a sharp decrease in the MLS(B) phenotype paralleled by an increase in the M phenotype. To gain further insight into these changes, 325 macrolide-resistant isolates were characterised using a combination of pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The use of Cfr9I, an isoschizomer of SmaI, to digest M phenotype isolates that were refractory to SmaI digestion allowed direct comparison of MLS(B) and M isolates. The results from PFGE and MLST were highly concordant and identified eight major clones, accounting for 92% of the isolates, each of which was associated exclusively with a single macrolide resistance phenotype. Two major clones were found among MLS(B) isolates, characterised by sequence types (ST) 46 (T12/emm22) and ST52 (T28/emm28), whereas clones characterised by ST39 (T4/emm4) and ST28 (T1/emm1) dominated among M isolates. The clone defined by ST52 corresponded to a bacitracin-resistant clone circulating in Europe, and a novel variant expressing other surface antigens (T12/emm22) was detected. The presence of the four major clones has been reported previously in other European countries, suggesting Europe-wide dissemination of a few macrolide-resistant lineages. PMID:16700698

  10. International circumpolar surveillance interlaboratory quality control program for emm typing of Streptococcus pyogenes, 2011-2015.

    PubMed

    Rudolph, Karen; Martin, Irene; Demczuk, Walter; Kakulphimp, Jocelyne; Bruden, Dana; Zulz, Tammy; Bruce, Michael

    2016-08-01

    In 2011, an interlaboratory quality control (QC) program for emm typing group A streptococci (GAS) was incorporated into existing international circumpolar surveillance QC programs. From 2011 - 2015, 35 GAS isolates were distributed to three laboratories; emm type-level concordance was 100%, while the overall sub-type level concordance was 83%. PMID:27238635

  11. Clonal diversity of Streptococcus pyogenes within some M-types revealed by multilocus enzyme electrophoresis.

    PubMed Central

    Haase, A. M.; Melder, A.; Mathews, J. D.; Kemp, D. J.; Adams, M.

    1994-01-01

    Twenty-two reference isolates and 30 local isolates of group A Streptococci were classified into 36 electrophoretic types (ET) on the basis of allozyme variation at 27 enzyme loci. Local isolates were characterized by a high frequency of M-non typable strains. M-type and ET were more closely associated in local isolates from an endemically-infected population; nevertheless, amongst the local isolates there were also strains of the same ET type with different M-types. A possible explanation is that genetic exchange between strains may introduce different M-types into strains of defined ET when these are exposed to strong selection in the presence of heavy loads of infection. In contrast to the reported clustering of strains associated with toxic shock-like syndrome into two closely related ET clones, we found no relationship of ET phenotype to acute poststreptococcal glomerulonephritis or rheumatic fever. PMID:7995355

  12. Activation of a 66-kilodalton human endothelial cell matrix metalloprotease by Streptococcus pyogenes extracellular cysteine protease.

    PubMed

    Burns, E H; Marciel, A M; Musser, J M

    1996-11-01

    Human umbilical vein endothelial cells (HUVECs) were used to gain insight into the molecular mechanism whereby the major extracellular protease from group A streptococci damages host tissue. HUVECs exposed to streptococcal cysteine protease (SCP) for various times exhibited cytopathic effect and cell detachment from the culture vessel. Gelatin substrate zymography showed that a time- and concentration-dependent increase in the level of activity of an approximately 66-kDa gelatinase occurred in culture medium taken from cells exposed to enzymatically active SCP. This gelatinase comigrated in gelatin zymograms with the activated form of purified recombinant matrix metalloprotease 2 (MMP-2) and had type IV collagenase activity. In contrast, medium taken from cells exposed to inactivated (boiled) SCP and cells exposed to SCP inhibited by treatment with N-benzyloxycarbonyl-leucyl-valyl-glycine diazomethyl ketone lacked the 66-kDa gelatinase. Appearance of the 66-kDa gelatinase activity was also prevented by 1,10-phenanthroline, a zinc chelator and MMP inhibitor. Inasmuch as proteolytically active SCP is required for the emergence of this gelatinase and MMP activation occurs by proteolytic processing, the 66-kDa gelatinase may be a proteolytic cleavage product of a latent MMP expressed extracellularly by HUVECs. Direct SCP treatment of culture supernatant taken from HUVECs not exposed to SCP also produced the 66-kDa gelatinase. The data show that SCP activates an MMP produced by human endothelial cells, a process that may contribute to endothelial cell damage, tissue destruction, and hemodynamic derangement observed in some patients with severe, invasive group A streptococcal infection. PMID:8890235

  13. Processing, stability, and kinetic parameters of C5a peptidase from Streptococcus pyogenes.

    PubMed

    Anderson, Elizabeth T; Wetherell, Michael G; Winter, Laurie A; Olmsted, Stephen B; Cleary, Patrick P; Matsuka, Yury V

    2002-10-01

    A recombinant streptococcal C5a peptidase was expressed in Escherichia coli and its catalytic properties and thermal stability were subjected to examination. It was shown that the NH2-terminal region of C5a peptidase (Asn32-Asp79/Lys90) forms the pro-sequence segment. Upon maturation the propeptide is hydrolyzed either via an autocatalytic intramolecular cleavage or by exogenous protease streptopain. At pH 7.4 the enzyme exhibited maximum activity in the narrow range of temperatures between 40 and 43 degrees C. The process of heat denaturation of C5a peptidase investigated by fluorescence and circular dichroism spectroscopy revealed that the protein undergoes biphasic unfolding transition with Tm of 50 and 70 degrees C suggesting melting of different parts of the molecule with different stability. Unfolding of the less stable structures was accompanied by the loss of proteolytic activity. Using synthetic peptides corresponding to the COOH-terminus of human complement C5a we demonstrated that in vitro peptidase catalyzes hydrolysis of two His67-Lys68 and Ala58-Ser59 peptide bonds. The high catalytic efficiency obtained for the SQLRANISHKDMQLGR extended peptide compared to the poor hydrolysis of its derivative Ac-SQLRANISH-pNA that lacks residues at P2'-P7' positions, suggest the importance of C5a peptidase interactions with the P' side of the substrate. PMID:12354115

  14. Activation of a 66-kilodalton human endothelial cell matrix metalloprotease by Streptococcus pyogenes extracellular cysteine protease.

    PubMed Central

    Burns, E H; Marciel, A M; Musser, J M

    1996-01-01

    Human umbilical vein endothelial cells (HUVECs) were used to gain insight into the molecular mechanism whereby the major extracellular protease from group A streptococci damages host tissue. HUVECs exposed to streptococcal cysteine protease (SCP) for various times exhibited cytopathic effect and cell detachment from the culture vessel. Gelatin substrate zymography showed that a time- and concentration-dependent increase in the level of activity of an approximately 66-kDa gelatinase occurred in culture medium taken from cells exposed to enzymatically active SCP. This gelatinase comigrated in gelatin zymograms with the activated form of purified recombinant matrix metalloprotease 2 (MMP-2) and had type IV collagenase activity. In contrast, medium taken from cells exposed to inactivated (boiled) SCP and cells exposed to SCP inhibited by treatment with N-benzyloxycarbonyl-leucyl-valyl-glycine diazomethyl ketone lacked the 66-kDa gelatinase. Appearance of the 66-kDa gelatinase activity was also prevented by 1,10-phenanthroline, a zinc chelator and MMP inhibitor. Inasmuch as proteolytically active SCP is required for the emergence of this gelatinase and MMP activation occurs by proteolytic processing, the 66-kDa gelatinase may be a proteolytic cleavage product of a latent MMP expressed extracellularly by HUVECs. Direct SCP treatment of culture supernatant taken from HUVECs not exposed to SCP also produced the 66-kDa gelatinase. The data show that SCP activates an MMP produced by human endothelial cells, a process that may contribute to endothelial cell damage, tissue destruction, and hemodynamic derangement observed in some patients with severe, invasive group A streptococcal infection. PMID:8890235

  15. Characterization of emm types and superantigens of Streptococcus pyogenes isolates from children during two sampling periods.

    PubMed

    Ma, Y; Yang, Y; Huang, M; Wang, Y; Chen, Y; Deng, L; Yu, S; Deng, Q; Zhang, H; Wang, C; Liu, L; Shen, X

    2009-10-01

    The characteristics of 359 group A streptococcal (GAS) isolates collected from Chinese paediatric patients in two periods (1993-1994, 2005-2006) were studied. Isolates were assigned to emm types and assayed for eight superantigen (SAg) genes (speA, speC, speH, speI, speG, speJ, ssa, SMEZ). Types emm1 and emm12 were consistently the most prevalent during the two periods, while others varied in frequency. GAS isolates carrying six or more SAg genes increased from 46.53% (1993-1994) to 78.39% (2005-2006); ssa, speH and speJ genes (P<0.05) increased but speA declined (P<0.05). SAg gene profiles were closely associated with the emm type, but strains of the same emm type sometimes carried different SAg genes in the two periods. No significant difference in emm-type distribution and SAg gene profile was noted between isolates from different diseases. These data may contribute towards the development of a GAS vaccine in China. PMID:19243651

  16. Rise and Persistence of Global M1T1 Clone of Streptococcus pyogenes

    PubMed Central

    Kotb, Malak

    2008-01-01

    The resurgence of severe invasive group A streptococcal infections in the 1980s is a typical example of the reemergence of an infectious disease. We found that this resurgence is a consequence of the diversification of particular strains of the bacteria. Among these strains is a highly virulent subclone of serotype M1T1 that has exhibited unusual epidemiologic features and virulence, unlike all other streptococcal strains. This clonal strain, commonly isolated from both noninvasive and invasive infection cases, is most frequently associated with severe invasive diseases. Because of its unusual prevalence, global spread, and increased virulence, we investigated the unique features that likely confer its unusual properties. In doing so, we found that the increased virulence of this clonal strain can be attributed to its diversification through phage mobilization and its ability to sense and adapt to different host environments; accordingly, the fittest members of this diverse bacterial community are selected to survive and invade host tissue. PMID:18826812

  17. Whole genome sequencing reveals extensive community-level transmission of group A Streptococcus in remote communities.

    PubMed

    Bowen, A C; Harris, T; Holt, D C; Giffard, P M; Carapetis, J R; Campbell, P T; McVERNON, J; Tong, S Y C

    2016-07-01

    Impetigo is common in remote Indigenous children of northern Australia, with the primary driver in this context being Streptococcus pyogenes [or group A Streptococcus (GAS)]. To reduce the high burden of impetigo, the transmission dynamics of GAS must be more clearly elucidated. We performed whole genome sequencing on 31 GAS isolates collected in a single community from children in 11 households with ⩾2 GAS-infected children. We aimed to determine whether transmission was occurring principally within households or across the community. The 31 isolates were represented by nine multilocus sequence types and isolates within each sequence type differed from one another by only 0-3 single nucleotide polymorphisms. There was evidence of extensive transmission both within households and across the community. Our findings suggest that strategies to reduce the burden of impetigo in this setting will need to extend beyond individual households, and incorporate multi-faceted, community-wide approaches. PMID:26833141

  18. Pyogenic Liver Abscess Caused by Acinetobacter lwoffii: A Case Report.

    PubMed

    Singh, N Pal; Sagar, Tanu; Nirmal, Kirti; Kaur, I Rajender

    2016-06-01

    Acinetobacter lwoffii is a gram negative aerobic non-fermenter bacilli. It is considered as an important emerging pathogen after Acinetobacter baumannii in patients with impaired immune system and in nosocomial infections. Here, we present a case of community acquired pyogenic liver Abscess caused by Acinetobacter lwoffii in a diabetic patient. PMID:27504286

  19. The Histopathological Spectrum of Pyogenic Granuloma: A Case Series

    PubMed Central

    Shrestha, Sajeev

    2016-01-01

    Background. Pyogenic granuloma is a reactive tumor-like lesion commonly affecting the oral cavity. These lesions usually appear as localized solitary nodule with a sessile or pedunculated base and colour varying from red, purplish, or pink, depending on the vascularity of the lesion. Pyogenic granuloma shows predilection for gingiva and is usually slow growing, but at times it shows rapid growth. The natural course of this lesion can be categorized into three distinct phases, namely, (i) cellular phase, (ii) capillary phase/vascular phase, and (iii) involutionary phase. Histopathologically, pyogenic granuloma is classified into lobular capillary hemangioma (LCH) and non-lobular capillary hemangioma (non-LCH). Case Presentation. In this series, four cases (varied age groups and both genders) of pyogenic granuloma showing varying histopathological presentation in relation to its clinical course have been described. The lesion in its early phase reveals diffuse endothelial cells, with few budding into capillaries. Among the capillary phase, the LCH type shows numerous blood vessels organized into lobular aggregates whereas the non-LCH type does not show any such organization and resembles granulation tissue. The involutionary phase shows healing of the lesion and is characterized by extensive fibrosis in the connective tissue. Conclusion. In conclusion, knowledge of the various histopathological presentation of this lesion is necessary for proper identification. PMID:27382492

  20. Pyogenic Liver Abscess Caused by Acinetobacter lwoffii: A Case Report

    PubMed Central

    Singh, N. Pal; Nirmal, Kirti; Kaur, I. Rajender

    2016-01-01

    Acinetobacter lwoffii is a gram negative aerobic non-fermenter bacilli. It is considered as an important emerging pathogen after Acinetobacter baumannii in patients with impaired immune system and in nosocomial infections. Here, we present a case of community acquired pyogenic liver Abscess caused by Acinetobacter lwoffii in a diabetic patient. PMID:27504286

  1. Acute pyogenic iliopsoas abscess in children in Nepal.

    PubMed

    Shah, R K; Singh, R P; Shah, N P

    2004-10-01

    We describe a prospective study of twenty-four cases of acute pyogenic abscess of the iliopsoas in children treated conservatively and operatively. Eight patients were managed conservatively with antibiotics alone while sixteen others were managed operatively by open drainage. All made a complete recovery. PMID:15510959

  2. Pyogenic Sacroiliitis in a 13-Month-Old Child

    PubMed Central

    Julien, Leroux; Isabelle, Bernardini; Lucie, Grynberg; Claire, Grandguillaume; Paul, Michelin; Mourad, Ould Slimane; Eric, Nectoux; François, Deroussen; Richard, Gouron; Audrey, Angelliaume; Brice, Ilharreborde; Mariette, Renaux-Petel

    2015-01-01

    Abstract Pyogenic sacroiliitis is exceptional in very young children. Diagnosis is difficult because clinical examination is misleading. FABER test is rarely helpful in very young children. Inflammatory syndrome is frequent. Bone scintigraphy and MRI are very sensitive for the diagnosis. Joint fluid aspiration and blood cultures are useful to identify the pathogen. Appropriate antibiotic therapy provides rapid regression of symptoms and healing. We report the case of pyogenic sacroiliitis in a 13-month-old child. Clinical, biological, and imaging data of this case were reviewed and reported retrospectively. A 13-month-old girl consulted for decreased weight bearing without fever or trauma. Clinical examination was not helpful. There was an inflammatory syndrome. Bone scintigraphy found a sacroiliitis, confirmed on MRI. Aspiration of the sacroiliac joint was performed. Empiric intravenous biantibiotic therapy was started. Patient rapidly recovered full weight bearing. On the 5th day, clinical examination and biological analysis returned to normal. Intravenous antibiotic therapy was switched for oral. One month later, clinical examination and biological analysis were normal and antibiotic therapy was stopped. Hematogenous osteoarticular infections are common in children but pyogenic sacroiliitis is rare and mainly affects older children. Diagnosis can be difficult because clinical examination is poor. Moreover, limping and decreased weight bearing are very common reasons for consultation. This may delay the diagnosis or refer misdiagnosis. Bone scintigraphy is useful to locate a bone or joint disease responsible for limping. In this observation, bone scintigraphy located the infection at the sacroiliac joint. Given the young age, MRI was performed to confirm the diagnosis. Despite the very young age of the patient, symptoms rapidly disappeared with appropriate antibiotic therapy. We report the case of pyogenic sacroiliitis in a 13-month-old child. It reminds the risk

  3. Recurrent Fusobacterium pyogenic myositis of the rotator cuff A case report of recurrent Fusobacterium pyogenic myositis of the rotator cuff

    PubMed Central

    McElnay, Philip J.; McCann, Philip A.; Williams, Martin O.; Wakeley, Charles J.; Amirfeyz, Rouin

    2014-01-01

    Pyogenic myositis is uncommon. It normally affects the large muscle groups in the lower limb or trunk and the most common causative organism is Staphylococcus aureus. We present a case of an immunocompetent man who, unusually, had a recurring form of the disease in subscapularis and teres minor. The causative organism was also highly unusual (Fusobacterium). PMID:24926162

  4. Replacement of histidine 340 with alanine inactivates the group A Streptococcus extracellular cysteine protease virulence factor.

    PubMed

    Gubba, S; Cipriano, V; Musser, J M

    2000-06-01

    Streptococcus pyogenes expresses a highly conserved extracellular cysteine protease that is a virulence factor for invasive disease, including soft tissue infection. Site-directed mutagenesis was used to generate a His340Ala recombinant mutant protein that was made as a stable 40-kDa zymogen by Escherichia coli. Purified His340Ala protein was proteolytically inactive when bovine casein and human fibronectin were used as substrates. Wild-type 28-kDa streptococcal protease purified from S. pyogenes processed the 40-kDa mutant zymogen to a 28-kDa mature form, a result suggesting that the derivative protein retained structural integrity. The data are consistent with the hypothesis that His340 is an enzyme active site residue, an idea confirmed by recent solution of the zymogen crystal structure (T. F. Kagawa, J. C. Cooney, H. M. Baker, S. McSweeney, M. Liu, S. Gubba, J. M. Musser, and E. N. Baker, Proc. Natl. Acad. Sci. USA 97:2235-2240, 2000). The data provide additional insight into structure-function relationships in this S. pyogenes virulence factor. PMID:10816533

  5. Replacement of Histidine 340 with Alanine Inactivates the Group A Streptococcus Extracellular Cysteine Protease Virulence Factor

    PubMed Central

    Gubba, Siddeswar; Cipriano, Vincent; Musser, James M.

    2000-01-01

    Streptococcus pyogenes expresses a highly conserved extracellular cysteine protease that is a virulence factor for invasive disease, including soft tissue infection. Site-directed mutagenesis was used to generate a His340Ala recombinant mutant protein that was made as a stable 40-kDa zymogen by Escherichia coli. Purified His340Ala protein was proteolytically inactive when bovine casein and human fibronectin were used as substrates. Wild-type 28-kDa streptococcal protease purified from S. pyogenes processed the 40-kDa mutant zymogen to a 28-kDa mature form, a result suggesting that the derivative protein retained structural integrity. The data are consistent with the hypothesis that His340 is an enzyme active site residue, an idea confirmed by recent solution of the zymogen crystal structure (T. F. Kagawa, J. C. Cooney, H. M. Baker, S. McSweeney, M. Liu, S. Gubba, J. M. Musser, and E. N. Baker, Proc. Natl. Acad. Sci. USA 97:2235–2240, 2000). The data provide additional insight into structure-function relationships in this S. pyogenes virulence factor. PMID:10816533

  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. 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

  8. Disease manifestations and pathogenic mechanisms of Group A Streptococcus.

    PubMed

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

    2014-04-01

    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

  9. 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. PMID:25670736

  10. Streptococcus iniae vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is among the most important emergent pathogens that affects many fish species worldwide, especially in warm-water regions. In marine and freshwater systems, this Gram-positive bacterium causes significant economic losses, estimated at hundreds of millions of dollars annually. Inf...

  11. Phenotypic differentiation of Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus strains within the "Streptococcus milleri group".

    PubMed Central

    Whiley, R A; Fraser, H; Hardie, J M; Beighton, D

    1990-01-01

    A biochemical scheme was developed by which strains of Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus can reliably be distinguished from within the "Streptococcus milleri group." Strains identified as S. intermedius were differentiated by the ability to produce detectable levels of alpha-glucosidase, beta-galactosidase, beta-D-fucosidase, beta-N-acetylgalactosaminidase, beta-N-acetylglucosaminidase, and sialidase with 4-methylumbelliferyl-linked fluorogenic substrates in microdilution trays after 3 h of incubation at 37 degrees C, together with the production of hyaluronidase. Strains of S. constellatus and S. anginosus were differentiated by the production of alpha-glucosidase and hyaluronidase by the former and the production of beta-glucosidase by the latter. The majority of strains of the S. milleri group obtained from dental plaque were identified as S. intermedius, as were most strains isolated from abscesses of the brain and liver. Strains of S. constellatus and S. anginosus were from a wider variety of infections, both oral and nonoral, than were strains of S. intermedius, with the majority of strains from urogenital infections being identified as S. anginosus. PMID:2380375

  12. Highly efficient heritable plant genome engineering using Cas9 orthologues from Streptococcus thermophilus and Staphylococcus aureus.

    PubMed

    Steinert, Jeannette; Schiml, Simon; Fauser, Friedrich; Puchta, Holger

    2015-12-01

    The application of the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas system of Streptococcus pyogenes (SpCas9) is currently revolutionizing genome engineering in plants. However, synthetic plant biology will require more complex manipulations of genomes and transcriptomes. The simultaneous addressing of different specific genomic sites with independent enzyme activities within the same cell is a key to this issue. Such approaches can be achieved by the adaptation of additional bacterial orthologues of the CRISPR/Cas system for use in plant cells. Here, we show that codon-optimised Cas9 orthologues from Streptococcus thermophilus (St1Cas9) and Staphylococcus aureus (SaCas9) can both be used to induce error-prone non-homologous end-joining-mediated targeted mutagenesis in the model plant Arabidopsis thaliana at frequencies at least comparable to those that have previously been reported for the S. pyogenes CRISPR/Cas system. Stable inheritance of the induced targeted mutations of the ADH1 gene was demonstrated for both St1Cas9- and SaCas9-based systems at high frequencies. We were also able to demonstrate that the SaCas9 and SpCas9 proteins enhance homologous recombination via the induction of double-strand breaks only in the presence of their species-specific single guide (sg) RNAs. These proteins are not prone to inter-species interference with heterologous sgRNA expression constructs. Thus, the CRISPR/Cas systems of S. pyogenes and S. aureus should be appropriate for simultaneously addressing different sequence motifs with different enzyme activities in the same plant cell. PMID:26576927

  13. Citrobacter koseri: an unusual cause of pyogenic liver abscess

    PubMed Central

    Gupta, Monica; Sharma, Alka; Singh, Ram; Lehl, S S

    2013-01-01

    Liver abscess is a common pathology in the Indian subcontinent and usually results from amoebic or bacterial infection. Pyogenic abscesses usually occur in those with underlying predisposing factors like intra-abdominal infections, biliary infections or comorbidities like malignancy, immunosuppression, diabetes mellitus and previous biliary surgery or interventional endoscopy. Citrobacter is an unusual cause of pyogenic liver abscess and may occur in the setting of underlying comorbidities. We report a 56-year-old man with diabetes (operated for periampullary carcinoma 20 years ago), who presented with a history of fever for 1 week and on evaluation was found to have Citrobacter koseri-related hepatic abscess. The patient was managed with parenteral antibiotics, repeated aspiration of liver abscess and pigtail drainage. PMID:23505286

  14. Diagnosis of hematogenous pyogenic vertebral osteomyelitis by magnetic resonance imaging

    SciTech Connect

    Meyers, S.P.; Wiener, S.N. )

    1991-04-01

    The clinical information and imaging data from 27 patients with hematogenous pyogenic vertebral osteomyelitis were reviewed. All patients had roentgenographic and magnetic resonance imaging examinations. Seventeen patients had computed tomograms; 17 had technetium Tc 99m medronate bone scans; and seven had gallium citrate Ga 67 scans. Magnetic resonance imaging, when used as a part of the initial radiologic evaluation, detected abnormalities consistent with osteomyelitis in all 27 patients. Magnetic resonance imaging also demonstrated paravertebral and/or epidural extension of infection in 14 patients, including seven patients who had neurologic signs of lower-extremity weakness. Roentgenograms, computed tomograms, technetium bone scans, and gallium scans had findings suggestive of the diagnosis in 48%, 65%, 71%, and 86% of the patients, respectively. We recommend magnetic resonance imaging as an important and perhaps critical imaging modality for detection of pyogenic vertebral osteomyelitis.

  15. Pyogenic granuloma underlying cutaneous horn in a young boy.

    PubMed

    Nair, Pragya A; Kota, Rahul Krishna S; Pilani, Abhisheik P

    2016-01-01

    Cutaneous horn is an elongated, keratinous projection that usually occurs over the sun-exposed areas. It is a clinical diagnosis and may overlie any benign, premalignant, or malignant conditions. Treatment includes wide surgical excision with careful histological examination to exclude a focus of malignancy. An unusual case of a pyogenic granuloma presenting as cutaneous horn on the lower lip in an 11-year-old boy is presented here. PMID:27057494

  16. Successful treatment of pyogenic granuloma with injection of absolute ethanol.

    PubMed

    Ichimiya, Makoto; Yoshikawa, Yoshiaki; Hamamoto, Yoshiaki; Muto, Masahiko

    2004-04-01

    Pyogenic granuloma (PG) is a small, almost always solitary, sessile or pedunculated, raspberry-like vegetation of exuberant granulation tissue. Conservative treatment by techniques such as cryosurgery, laser surgery, and electrodesiccation are usually adequate, whereas excisional treatment can often result in noticeable scars. We attempted a different approach using an injection of absolute ethanol in five patients with recurrence due to inadequate cryosurgery. This therapy is less invasive than surgical excision and appears to be an alternative therapy for PG. PMID:15187331

  17. Pyogenic granuloma underlying cutaneous horn in a young boy

    PubMed Central

    Nair, Pragya A.; Kota, Rahul Krishna S.; Pilani, Abhisheik P.

    2016-01-01

    Cutaneous horn is an elongated, keratinous projection that usually occurs over the sun-exposed areas. It is a clinical diagnosis and may overlie any benign, premalignant, or malignant conditions. Treatment includes wide surgical excision with careful histological examination to exclude a focus of malignancy. An unusual case of a pyogenic granuloma presenting as cutaneous horn on the lower lip in an 11-year-old boy is presented here. PMID:27057494

  18. [Study of pyogenic granuloma of the oral cavity].

    PubMed

    Inagi, K; Takahashi, H O; Yao, K; Kamata, T

    1991-12-01

    Pyogenic granuloma is one of the diseases sometimes seen in otorhinolaryngology clinics. The clinical features of this disease are understood to be that the lesion is located in the oral cavity in the majority of cases that its causative agent is usually discovered and that it most likely grows as a malignant tumor. However, the entity of pathological diagnosis has not been established. Thirty-one cases of oral pyogenic granuloma, including 16 males and 15 females, are reported in this paper. The granuloma was located most frequently at the tongue, followed, in order, by the gingiva, buccal mucosa, hard palate, lip and oral floor. The period between the patient's first visit to our clinic and the onset of his/her complaint was variable. It was relatively shorter in those cases with the lesion at the gingiva or tongue as compared to other locations. The size of the lesion was smaller than 10 x 10 mm. We classified the pathological features into three patterns; granuloma type, hemangioma type, and intermediate type. Many cases of lesions located at the back of the tongue, buccal mucosa, or hard palate were of the hemangioma type, while many cases of lesions located at the top of the tongue, gingiva, or oral floor were of the granuloma type. We have the impression that pyogenic granuloma could be one of the purulent changes associated with benign oral tumors. PMID:1779270

  19. Atlantoaxial Subluxation after Pyogenic Spondylitis around the Odontoid Process.

    PubMed

    Hasegawa, Atsushi; Yagi, Mitsuru; Takemitsu, Masakazu; Machida, Masafumi; Asazuma, Takashi; Ichimura, Shoichi

    2015-01-01

    Study Design. A case report and review of the literature. Objective. The aim of this study was to describe the conservative management of pyogenic spondylitis around the odontoid process. Summary of Background Data. Atlantoaxial subluxation after pyogenic spondylitis is rare. The therapeutic approach to infection of the upper cervical spine is controversial. Methods. Medical chart and radiological images of a 76-year-old male patient were retrospectively reviewed. Radiography revealed atlantoaxial subluxation, and an abscess was seen around the odontoid process on magnetic resonance images. Intravenous antibiotics and a halo vest were used to treat the patient. We then observed the patient's conservative treatment course. Results. C-reactive protein levels returned to normal 4 weeks after administration of the intravenous antibiotics. The patient's muscle weakness also completely recovered 8 weeks after administration of the intravenous antibiotics. Because the patient was able to walk without any support, surgical treatment was not necessary. Conclusions. Pyogenic spondylitis of the upper cervical spine is a rare manifestation. Surgical or conservative treatment must be selected carefully based on the patient's symptoms. If early diagnosis and treatment can be provided to the patients, conservative treatment can be achieved. PMID:26090255

  20. Characterization of the haem-uptake system of the equine pathogen Streptococcus equi subsp. equi.

    PubMed

    Meehan, Mary; Burke, Fiona M; Macken, Susan; Owen, Peter

    2010-06-01

    Streptococcus equi possesses a haem-uptake system homologous to that of Streptococcus pyogenes and Streptococcus zooepidemicus. The system consists of two ligand-binding proteins (Shr and Shp) and proteins (HtsA-C) with homology to an ABC transporter. The haem-uptake system of S. equi differs from that of S. pyogenes and S. zooepidemicus in that Shr is truncated by two-thirds. This study focused on the SeShr, SeShp and SeHtsA proteins of S. equi. Analysis of shr, shp and shphtsA knockout mutants showed that all three proteins were expressed in vitro and that expression was upregulated under conditions of iron limitation. SeShr possesses no membrane-/cell wall-spanning sequences and was shown to be secreted. Both SeShp and SeHtsA were confirmed to be envelope-associated. Recombinant SeShp and SeHtsA proteins have been previously shown to bind haem and SeHtsA could capture haem from SeShp. This report extends these studies and shows that both SeShp and SeHtsA can sequester haem from haemoglobin but not from haemoglobin-haptoglobin complexes. Like full-length Shr, SeShr possesses haemoglobin and haemoglobin-haptoglobin binding ability but unlike full-length Shr, it lacks haem- or fibronectin-binding capabilities. Analysis of SeShr truncates showed that residues within and upstream of the near transporter (NEAT) domain are required for this ligand binding. Structural predictions suggest that truncation of NEAT1 in SeShr accounts for its impaired ability to bind haem. Haem and haemoglobin restored to almost normal the impaired growth rates of wild-type S. equi cultured under iron-limiting conditions. However, no difference in the growth rates of wild-type and mutants could be detected under the in vitro growth conditions tested. PMID:20223800

  1. Distribution of streptococcal inhibitor of complement variants in pharyngitis and invasive isolates in an epidemic of serotype M1 group A Streptococcus infection.

    PubMed

    Hoe, N P; Vuopio-Varkila, J; Vaara, M; Grigsby, D; De Lorenzo, D; Fu, Y X; Dou, S J; Pan, X; Nakashima, K; Musser, J M

    2001-02-15

    Streptococcal inhibitor of complement (Sic) is a highly polymorphic extracellular protein made predominantly by serotype M1 group A Streptococcus (GAS). New variants of the Sic protein frequently appear in M1 epidemics as a result of positive natural selection. To gain further understanding of the molecular basis of M1 epidemics, the sic gene was sequenced from 471 pharyngitis and 127 pyogenic and blood isolates recovered from 598 patients living in metropolitan Helsinki, Finland, during a 37-month population-based surveillance study. Most M1 GAS subclones recovered from pyogenic infections and blood were abundantly represented in the pool of subclones causing pharyngitis. Alleles shared among the pharyngitis, pyogenic, and blood samples were identified in throat isolates a mean of 9.8 months before their recovery from pyogenic infections and blood, which indicates that selection of most sic variants occurs on mucosal surfaces. In contrast, no variation was identified in the emm and covR/covS genes. PMID:11170990

  2. Serine/Threonine Protein Kinase Stk Is Required for Virulence, Stress Response, and Penicillin Tolerance in Streptococcus pyogenes▿

    PubMed Central

    Bugrysheva, Julia; Froehlich, Barbara J.; Freiberg, Jeffrey A.; Scott, June R.

    2011-01-01

    Genes encoding one or more Ser/Thr protein kinases have been identified recently in many bacteria, including one (stk) in the human pathogen Streptococcus pyogenes (group A streptococcus [GAS]). We report that in GAS, stk is required to produce disease in a murine myositis model of infection. Using microarray and quantitative reverse transcription-PCR (qRT-PCR) studies, we found that Stk activates genes for virulence factors, osmoregulation, metabolism of α-glucans, and fatty acid biosynthesis, as well as genes affecting cell wall synthesis. Confirming these transcription studies, we determined that the stk deletion mutant is more sensitive to osmotic stress and to penicillin than the wild type. We discuss several possible Stk phosphorylation targets that might explain Stk regulation of expression of specific operons and the possible role of Stk in resuscitation from quiescence. PMID:21788381

  3. Draft Genome Sequence of Trueperella pyogenes, Isolated from the Infected Uterus of a Postpartum Cow with Metritis.

    PubMed

    Goldstone, Robert J; Amos, Matt; Talbot, Richard; Schuberth, Hans-Joachim; Sandra, Olivier; Sheldon, I Martin; Smith, David G E

    2014-01-01

    Trueperella pyogenes is a common commensal bacterium and an opportunistic pathogen associated with chronic purulent disease, particularly in ruminants. We report here the genome sequence of a T. pyogenes isolate from a severe case of bovine metritis. This is the first full record of a T. pyogenes genome. PMID:24762932

  4. Properties and antimicrobial susceptibility of Trueperella pyogenes isolated from bovine mastitis in China.

    PubMed

    Alkasir, Rashad; Wang, Jianfang; Gao, Jian; Ali, Tariq; Zhang, Limei; Szenci, Ottó; Bajcsy, Árpád Csaba; Han, Bo

    2016-03-01

    Trueperella (T.) pyogenes is an opportunistic pathogen that causes suppurative diseases in domestic animals. In this work, the properties, pathogenesis and phenotypic diversity of T. pyogenes isolates from bovine mastitis were studied. Both pyolysin (plo) and collagen-binding protein (cbp) virulence factor genes were detected by PCR in all T. pyogenes isolates (n = 50). Using the tissue culture plate method, 90% of T. pyogenes isolates were able to form biofilms. The minimum inhibitory concentrations (MICs) of 13 antimicrobials against T. pyogenes isolates were determined. High susceptibility was observed to rifampin (96%), ampicillin (94%), ciprofloxacin (94%), and penicillin (92%), while low susceptibility was found to trimethoprim-sulphamethoxazole (10%) and bacitracin (2%). The intracellular assay revealed that T. pyogenes isolates had different cytopathogenic effects on cells. The high percentage (28.6%) of T. pyogenes isolates suggests that this bacterium is an important contributor to mastitis. Moreover, the high occurrence of multidrug resistance, biofilm production, intracellular survival, and the temporal dynamics of T. pyogenes interactions are key factors for a better understanding of how immunity acts on infections with these bacteria and how they evade immune surveillance, thus highlighting the need for the prudent use of antimicrobial agents in veterinary medicine. PMID:26919137

  5. An uncommon cause of recurrent pyogenic meningitis: pituitary abscess

    PubMed Central

    Walia, Rama; Bhansali, Anil; Dutta, Pinaki; Shanmugasundar, G; Mukherjee, Kanchan Kumar; Upreti, Vimal; Das, Ashim

    2010-01-01

    The authors report a 36-year-old male who presented with headache and hypopituitarism, and MRI revealed a ring enhancing lesion with pituitary stalk thickening. During follow-up, he presented with recurrent pyogenic meningitis with persistence of the lesion, therefore a diagnosis of pituitary abscess was considered. He underwent trans-sphenoidal surgery (TSS) with evacuation of pus and received antibiotic treatment for the same. After this he remarkably improved and had no recurrence of symptoms. He is on levothyroxine, glucocorticoids and testosterone replacement therapy for his respective hormone deficits. PMID:22767626

  6. Recurrent oral pyogenic granuloma in port-wine stain.

    PubMed

    da Silva, Alessandra Dutra; Silva, Carolina Amália Barcellos; de Camargo Moraes, Paulo; Thomaz, Luiz Alexandre; Furuse, Cristiane; de Araújo, Vera Cavalcanti

    2011-11-01

    Pyogenic granuloma (PG) is a benign inflammatory lesion, nonneoplastic in nature, which occurs in the oral cavity and skin. This lesion arises in response to various stimuli such as low-grade local irritations, traumatic injury, or hormonal factors. Recently, in some cases, the occurrence of recurrent PGs in skin associated with vascular lesions, such as port-wine stains, has been described. It has been postulated that this association is promoted by arteriovenous anastomoses in the vascular lesions, leading to the development of PG. The authors discuss 2 cases of recurrent PG in patients with a port-wine stain, and the treatment options adopted. PMID:22134277

  7. Profusely bleeding oral pyogenic granuloma in a teenage girl.

    PubMed

    Singh, Rajeev Kumar; Kaushal, Ambrish; Kumar, Rakesh; Pandey, Ramesh Kumar

    2013-01-01

    Pyogenic granuloma (PG) is a kind of inflammatory hyperplastic soft tissue lesion of the oral cavity. The lesion, however, is not related to infection and arise as a reactive growth in response to various stimuli. It has a very high vascularity because of the presence of numerous prominent capillaries. The lesion has a bleeding tendency, even after a minor traumatic episode, such as during mastication. Bleeding may be at times very severe and difficult to control. We present the case of a profusely bleeding young PG in a young teenage child. PMID:23486345

  8. Oral pyogenic granuloma in hemophilia: a report of 2 cases.

    PubMed

    Lindsay, Holly; Srivaths, Lakshmi V

    2014-07-01

    Pyogenic granulomas (PGs) are benign vascular lesions occurring in skin and mucous membranes, often secondary to trauma or chronic inflammation. Oral PGs have never been described previously in hemophilia. We describe 2 pediatric patients with hemophilia A, who developed PGs with inadequate factor therapy for bleeding. PG pathophysiology suggests an association with hemophilia given chronic vascular damage and low-grade inflammation at sites of bleeding in hemophilia patients. Knowledge about the occurrence of PGs in hemophilia patients is essential for prompt diagnosis and early institution of factor therapy, which in turn allows more rapid cessation of bleeding and lesion involution. PMID:24663071

  9. Oral pyogenic granuloma: a review of 137 cases.

    PubMed

    Saravana, G H L

    2009-06-01

    We retrospectively reviewed 137 cases of histologically confirmed pyogenic granuloma of the oral cavity from the records of the Department of Oral Surgery, Bharat Heavy Electricals Hospital, Trichy, India between 1996 and 2006. The most commonly affected site was the gingiva (n=114, 83%). Mean age of patients was 31 years (range 6-85, male to female ratio 1:2.6). Simple excision is enough to prevent recurrence, but the aetiology and pathogenesis of the lesion must be known to understand its nature. PMID:19203815

  10. Pyogenic granuloma after transconjunctival blepharoplasty: a case report.

    PubMed

    Soll, S M; Lisman, R D; Charles, N C; Palu, R N

    1993-12-01

    This is the first known report of a relatively large postoperative pyogenic granuloma developing after a nonsutured transconjunctival blepharoplasty. Inflammation and separation or malapposition of the conjunctival wound edges probably permitted the lesion to proliferate in the inferior fornix. No foreign material could be implicated because no suture was used to close this incision. Additionally, Polydek suture material (braided polyester fiber) was associated with the complication of a suture tract and granuloma when used for a tarsal suspension procedure for ectropion repair in this patient. PMID:8305380

  11. Periungual Pyogenic Granuloma: The Importance of the Medical History

    PubMed Central

    Alessandrini, Aurora; Bruni, Francesca; Starace, Michela; Piraccini, Bianca Maria

    2016-01-01

    Pyogenic granuloma (PG) is a common, benign vascular proliferation that can arise on the skin or subcutaneous tissue. It is more frequent in the early decades of life, and the most common locations are the digits of both hands and feet. The most common cause of periungual PG is drug intake, but many other trigger factors have been described in the literature. Treatment should be chosen according to the cause. We describe 2 particular cases of periungual PG in which the clinical history has been fundamental. In the first case, there was an underlying hand eczema, and in the second case, a foreign body was present. PMID:27386461

  12. Repression of virulence genes by phosphorylation-dependent oligomerization of CsrR at target promoters in S. pyogenes.

    PubMed

    Miller, A A; Engleberg, N C; DiRita, V J

    2001-05-01

    csrRS encodes a two-component regulatory system that represses the transcription of a number of virulence factors in Streptococcus pyogenes, including the hyaluronic acid capsule and pyrogenic exotoxin B. CsrRS-regulated virulence factors have diverse functions during pathogenesis and are differentially expressed throughout growth. This suggests that multiple signals induce CsrRS-mediated gene regulation, or that regulated genes respond differently to CsrR, or both. As a first step in dissecting the csrRS signal transduction pathway, we determined the mechanism by which CsrR mediates the repression of its target promoters. We found that phosphorylated CsrR binds directly to all but one of the promoters of its regulated genes, with different affinities. Phosphorylation of CsrR enhances both oligomerization and DNA binding. We defined the binding site of CsrR at each of the regulated promoters using DNase I and hydroxyl radical footprinting. Based on these results, we propose a model for differential regulation by CsrRS. PMID:11401704

  13. Phospholipids of Streptococcus faecalis

    PubMed Central

    Mota, J. M. dos Santos; Den Kamp, J. A. F. Op; Verheij, H. M.; Van Deenen, L. L. M.

    1970-01-01

    Autoradiograms of total lipid extracts from Streptococcus faecalis ATCC 9790, harvested in the stationary phase from a medium containing 32P-orthophosphate, showed six major spots. The corresponding compounds were identified as diphosphatidylglycerol (possibly with a penta acyl structure); phosphatidylglycerol; a provisionally identified mixture of alanylphosphatidylglycerol and of the 2′-lysyl-derivative of phosphatidylglycerol; the 3′-lysyl-derivative of phosphatidylglycerol, probably together with some arginylphosphatidylglycerol; a diglucosyl derivative of phosphatidylglycerol; and a compound which was tentatively identified as the 2′,3′-dilysyl derivative of phosphatidylglycerol. Images PMID:4321329

  14. Streptolysin S of Streptococcus anginosus exhibits broad-range hemolytic activity.

    PubMed

    Asam, Daniela; Mauerer, Stefanie; Spellerberg, Barbara

    2015-04-01

    Streptococcus anginosus is a commensal of mucous membranes and an emerging human pathogen. Some strains, including the type strain, display a prominent β-hemolytic phenotype. A gene cluster (sag), encoding a variant of streptolysin S (SLS) has recently been identified as the genetic background for β-hemolysin production in S. anginosus. In this study, we further characterized the hemolytic and cytolytic activity of the S. anginosus hemolysin in comparison with other streptococcal hemolysins. The results indicate that SLS of S. anginosus is a broad-range hemolysin able to lyse erythrocytes of different species, including horse, bovine, rabbit and even chicken. The hemolytic activity is temperature dependent, and a down-regulation of the hemolysin expression is induced in the presence of high glucose levels. Survival assays indicate that in contrast to other streptococcal species, S. anginosus does not require SLS for survival in the presence of human granulocytes. Cross-complementation studies using the sagB and sagD genes of Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis demonstrated functional similarities to the S. anginosus SLS. Nevertheless, distinct differences to other streptolysin S variants were noted and provide further insights into the molecular mechanisms of SLS pathogen host interactions. PMID:25381594

  15. A Genome-Wide Profiling Strategy as an Aid for Searching Unique Identification Biomarkers for Streptococcus.

    PubMed

    Kalia, Vipin Chandra; Kumar, Ravi; Kumar, Prasun; Koul, Shikha

    2016-03-01

    The use of rrs (16S rRNA) gene is widely regarded as the "gold standard" for identifying bacteria and determining their phylogenetic relationships. Nevertheless, multiple copies of this gene in a genome is likely to give an overestimation of the bacterial diversity. In each of the 50 Streptococcus genomes (16 species, 50 strains), 4-7 copies of rrs are present. The nucleotide sequences of these rrs genes show high similarity within and among genomes, which did not allow unambiguous identification. A genome-wide search revealed the presence of 27 gene sequences common to all the Streptococcus species. Digestion of these 27 gene sequences with 10 type II restriction endonucleases (REs) showed that unique RE digestion in purH gene is sufficient for clear cut identification of 30 genomes belonging to 16 species. Additional gene-RE combinations allowed identification of another 15 strains belonging to S. pneumoniae, S. pyogenes, and S. suis. For the rest 5 strains, a combination of 2 genes was required for identifying them. The proposed strategy is likely to prove helpful in proper detection of pathogens like Streptococcus. PMID:26843696

  16. Gas-Forming Pyogenic Liver Abscess with Septic Shock

    PubMed Central

    Ishaq, Muhammad K.; Jones, Kellie R.

    2015-01-01

    The pyogenic liver abscess caused by Clostridium perfringens (C. perfringens) is a rare but rapidly fatal infection. The main virulence factor of this pathogen is its α-toxin (lecithinase), which decomposes the phospholipid in cell membranes leading to cell lysis. Once the bacteria are in blood stream, massive intravascular hemolysis occurs. This can present as anemia on admission with evidence of hemolysis as indicated by low serum haptoglobin, high serum lactate dehydrogenase (LDH), elevated indirect bilirubin, and spherocytosis. The clinical course of C. perfringens septicemia is marked by rapidly deteriorating course with a mortality rate ranging from 70 to 100%. The very rapid clinical course makes it difficult to diagnose on time, and most cases are diagnosed at autopsy. Therefore it is important to consider C. perfringens infection in any severely ill patient with fever and evidence of hemolysis. We present a case of seventy-seven-year-old male with septic shock secondary to pyogenic liver abscess with a brief review of existing literature on C. perfringens. PMID:26090240

  17. Recurrent Pyogenic Granuloma Around Dental Implants: A Rare Case Report.

    PubMed

    Gefrerer, Lidia; Popowski, Wojciech; Perek, Jan Nikodem; Wojtowicz, Andrzej

    2016-01-01

    The aim of this article is to present a rare case of a bilateral recurring pyogenic granuloma around dental implants supported by autogenic bone graft. A 55-year-old woman was treated with vertical bone augmentation and dental implants on both sides in the mandible. The patient was followed up for 2 years. Growing granuloma was observed 3 weeks after implants were loaded with splinted porcelain-fused-to-metal crowns. The granulomatous tissue was removed and samples were evaluated histologically and microbiologically with real-time polymerase chain reaction. The pathologic lesion recurred four times on one side and three times on the other side and was removed after each recurrence. Finally, the patient decided to have the implants removed due to the aggressive, permanent, and relapsing nature of the proliferative lesions associated with exposed implant threads. After implant removal, no hyperplasia was seen. Microbiologic contamination was excluded as a cause of this recurring granuloma, and it was presumed that the lesion could have been associated with an insufficient zone of attached gingiva around the implants and exposure of implant threads. However, the etiology of this pyogenic granuloma remains unknown. Due to the high recurrence rate of reactive hyperplastic lesions, a long-term follow-up is necessary. PMID:27333016

  18. Community-Acquired Methicillin-Resistant Pyogenic Liver Abscess

    PubMed Central

    Cherian, Joel; Singh, Rahul; Varma, Muralidhar; Vidyasagar, Sudha; Mukhopadhyay, Chiranjay

    2016-01-01

    Pyogenic liver abscesses are rare with an incidence of 0.5% to 0.8% and are mostly due to hepatobiliary causes (40% to 60%). Most are polymicrobial with less than 10% being caused by Staphylococcus aureus. Of these, few are caused by methicillin-resistant Staphylococcus aureus (MRSA) and fewer still by a community-acquired strain. Here we present a case study of a patient with a community-acquired MRSA liver abscess. The patient presented with fever since 1 month and tender hepatomegaly. Blood tests revealed elevated levels of alkaline phosphatase, C-reactive protein, erythrocyte sedimentation rate, and neutrophilic leukocytosis. Blood cultures were sterile. Ultrasound of the abdomen showed multiple abscesses, from which pus was drained and MRSA isolated. Computed tomography of the abdomen did not show any source of infection, and an amebic serology was negative. The patient was started on vancomycin for 2 weeks, following which he became afebrile and was discharged on oral linezolid for 4 more weeks. Normally a liver abscess is treated empirically with ceftriaxone for pyogenic liver abscess and metronidazole for amebic liver abscess. However, if the patient has risk factors for a Staphylococcal infection, it is imperative that antibiotics covering gram-positive organisms be added while waiting for culture reports. PMID:27540556

  19. Posthaste Outgrow of Lip Pyogenic Granuloma after Diode Laser Removal

    PubMed Central

    Asnaashari, Mohammad; Bigom-Taheri, Jamile; Mehdipoor, Maesoome; Bakhshi, Mahin

    2014-01-01

    Introduction: Pyogenic granuloma (PG) is one of the inflammatory hyperplasia seen in the oral cavity. It is a reactional response to minor trauma or chronic irritation and also might be related to hormonal changes. Rarely, PG occurs extragingivally.The most common treatment of PG is surgical excision but alternative approaches such as laser excision have also been proposed. Case report: Herein, we present a case of lip pyogenic granuloma in a 15-year-old male whom had been under orthodontic treatment. The lesion was first excised with diode laser as a conservative method, but the lesion had immediately recurred and was excised with surgical blade as the traditional method. No recurrence or scarring was observed in 6 months follow-up. Results and conclusion: Although the use of laser as modern medicine offers a new tool for treatment of oral lesions, scalpel (blade) surgical excision still seems to be the successful treatment of choice in minimizing the recurrence of lesion especially when exacerbating factors such as hormonal imbalances exist. PMID:25653806

  20. Pyogenic granuloma in relation to dental implants: Clinical and histopathological findings

    PubMed Central

    Pinas, Laura

    2015-01-01

    Background The occurrence of pyogenic granuloma in association to dental implants is rare and only five cases have been reported in the literature. Material and Methods Patients charts were analyzed to select patients who had been diagnosed for pyogenic granuloma and its association with dental implants had been evaluated. The clinical status of the dental implants and the prosthesis had also been assessed. Results Clinical and histopathological diagnosis of pyogenic granuloma had been reached for soft mass growth in association with dental implants in 10 patients. Histological analysis of all samples was performed to obtain a firm diagnosis of finding against pyogenic granuloma lesions. Accumulation of dental plaque due to poor oral hygiene and improper design of the prosthesis had been related to the occurrence of pyogenic granuoloma. This lesion showed no predilection to specific surface type and had no significant association with marginal bone loss. Conclusions Pyogenic granuloma should be included in the differential diagnosis of soft mass growth around dental implants. Key words:Reactive lesion, soft mass, pyogenic granuloma, dental implant, titanium. PMID:26535087

  1. Pyogenic granuloma occurring in a postmenopausal woman on hormone replacement therapy.

    PubMed

    Johnson, Thomas M; Demsar, Williamr J; Herold, Robert W; Bisch, Frederick C; Gerlach, Robert C; Swiec, Gary D

    2011-01-01

    Pyogenic granuloma is a benign nodular lesion occurring most commonly on the gingiva of females during periods of elevated sex hormones such as puberty and pregnancy. Possible molecular mechanisms responsible for the appearance of pyogenic granuloma in this demographic have been suggested. Increased incidence of pyogenic granuloma in post menopausal women on hormone replacement therapy has not been reported. A 49-year-old woman with preexisting titanium implant placement in the left posterior mandible presented with complaint of food impaction and slight discomfort associated with the implant. Clinical examination revealed slight soft tissue erythema and edema, but no foreign body could be identified. Subsequently, a nodular gingival lesion associated with the implant developed and was treated by conservative surgical excision. Histologic characteristics of the lesion were consistent with pyogenic granuloma. The patient was informed of the diagnosis. No evidence of recurrence could be identified after 6 months. Like peripubertal and pregnant women, postmenopausal women treated with hormone replacement therapy may be at increased risk for pyogenic granuloma. Observational studies designed to establish an association between hormone replacement therapy and pyogenic granuloma have not been conducted. Dentists should be aware of putative pathophysiologic mechanisms for pyogenic granuloma formation and the possibility that hormone replacement may trigger these mechanisms. PMID:21409768

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

    PubMed Central

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

    1984-01-01

    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. PMID:6490816

  3. A New Alkaline pH-Adjusted Medium Enhances Detection of β-Hemolytic Streptococci by Minimizing Bacterial Interference Due to Streptococcus salivarius

    PubMed Central

    Dierksen, Karen P.; Ragland, Nancy L.; Tagg, John R.

    2000-01-01

    A new selective medium (CNA-P) that reduces or eliminates the inhibitory activity of bacteriocin-producing Streptococcus salivarius against β-hemolytic streptococci has been developed and compared with sheep blood agar (SBA) for the sensitive detection of small numbers of β-hemolytic streptococci in clinical specimens. CNA-P has as its basis a commercial medium (Difco Columbia CNA agar) supplemented with 5% (vol/vol) sheep blood, and the CNA is further modified by addition of 100 mM PIPES buffer [piperazine-N,N′-bis(2-ethanesulfonic acid)] (pH 7.5) to maintain cultures at an alkaline pH during incubation. CNA-P was shown to inhibit the production and/or release of four different types of S. salivarius bacteriocins or bacteriocin-like inhibitory molecules. The efficacies of CNA-P and SBA for detection of β-hemolytic streptococci in 1,352 pharyngeal samples from 376 children were compared. The β-hemolytic streptococcal isolates recovered from the samples included 314 group A (S. pyogenes), 61 group G, 33 group B, and 5 group C streptococci. Of 314 samples that yielded S. pyogenes, 300 were positive on CNA-P (96%) and 264 (86%) were positive on SBA. A significantly greater number of S. pyogenes isolates from these samples were recovered only on CNA-P (50 of 314) compared with the number of isolates recovered only on SBA (14 of 314). In addition, the degree of positivity, a measure of the total numbers of S. pyogenes isolates on the plate, was significantly higher on CNA-P than on SBA (2.40 versus 2.07; P < 0.001). Interestingly, CNA-P was also found to enhance the hemolytic activity of streptolysin O, allowing detection of streptolysin S-deficient S. pyogenes strains which might otherwise go undetected on SBA and other isolation media. PMID:10655361

  4. Comparative genomics and the role of lateral gene transfer in the evolution of bovine adapted Streptococcus agalactiae.

    PubMed

    Richards, Vincent P; Lang, Ping; Bitar, Paulina D Pavinski; Lefébure, Tristan; Schukken, Ynte H; Zadoks, Ruth N; Stanhope, Michael J

    2011-08-01

    In addition to causing severe invasive infections in humans, Streptococcus agalactiae, or group B Streptococcus (GBS), is also a major cause of bovine mastitis. Here we provide the first genome sequence for S. agalactiae isolated from a cow diagnosed with clinical mastitis (strain FSL S3-026). Comparison to eight S. agalactiae genomes obtained from human disease isolates revealed 183 genes specific to the bovine strain. Subsequent polymerase chain reaction (PCR) screening for the presence/absence of a subset of these loci in additional bovine and human strains revealed strong differentiation between the two groups (Fisher exact test: p<0.0001). The majority of the bovine strain-specific genes (∼ 85%) clustered tightly into eight genomic islands, suggesting these genes were acquired through lateral gene transfer (LGT). This bovine GBS also contained an unusually high proportion of insertion sequences (4.3% of the total genome), suggesting frequent genomic rearrangement. Comparison to other mastitis-causing species of bacteria provided strong evidence for two cases of interspecies LGT within the shared bovine environment: bovine S. agalactiae with Streptococcus uberis (nisin U operon) and Streptococcus dysgalactiae subsp. dysgalactiae (lactose operon). We also found evidence for LGT, involving the salivaricin operon, between the bovine S. agalactiae strain and either Streptococcus pyogenes or Streptococcus salivarius. Our findings provide insight into mechanisms facilitating environmental adaptation and acquisition of potential virulence factors, while highlighting both the key role LGT has played in the recent evolution of the bovine S. agalactiae strain, and the importance of LGT among pathogens within a shared environment. PMID:21536150

  5. Surgical removal of an oral pyogenic granuloma and subsequent root coverage with a pedicle graft.

    PubMed

    Oliveira, Thais M; Greghi, Sebastião L A; Taveria, Luís A A; Santos, Carlos F; Machado, Maria Aparecida A M; Silva, Salete M B

    2008-01-01

    Pyogenic granuloma (PG) is a lesion characterized by non-neoplastic proliferation of endothelial cells, occurring in gingival tissue and representing an excessive reaction of the connective tissue to stimuli or injuries. The purpose of this report was to describe the treatment of an oral pyogenic granuloma, with emphasis on clinical, histopathological, and radiographic aspects. The surgical therapy comprised lesion excision followed by pedicle graft to cover the exposed root surface. The patient's pyogenic granuloma has been under control for a year, and recurrence has not been observed. The permanent teeth erupted correctly and the gingival tissue of both the receptor and donor sites shows a satisfactory clinical appearance. PMID:18505649

  6. Multiple pyogenic granuloma of the penis in a four-year-old child: a case report

    PubMed Central

    Di Giacomo, Martina; Bertocchini, Alessia; Loggini, Barbara; Pingitore, Raffaele

    2009-01-01

    Pyogenic granulomas are common, acquired, benign vascular lesions of the skin and mucous membranes that can develop both spontaneously and traumatically. We present a unique case of a four-year healthy, uncircumcised boy with multiple pyogenic granuloma on the mucous face of the penis foreskin. Although penile multiple pyogenic granulomas have previously been described in adults, there are no reports of similar problems in children. In this patient, the pathogenesis of the lesions is probably trauma related as reported in the anamnesis. Therapeutic options are discussed. PMID:19918487

  7. Multiple pyogenic granuloma of the penis in a four-year-old child: a case report.

    PubMed

    Spinelli, Claudio; Di Giacomo, Martina; Bertocchini, Alessia; Loggini, Barbara; Pingitore, Raffaele

    2009-01-01

    Pyogenic granulomas are common, acquired, benign vascular lesions of the skin and mucous membranes that can develop both spontaneously and traumatically. We present a unique case of a four-year healthy, uncircumcised boy with multiple pyogenic granuloma on the mucous face of the penis foreskin. Although penile multiple pyogenic granulomas have previously been described in adults, there are no reports of similar problems in children. In this patient, the pathogenesis of the lesions is probably trauma related as reported in the anamnesis. Therapeutic options are discussed. PMID:19918487

  8. 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

  9. 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

  10. Anionic Lipids Enriched at the ExPortal of Streptococcus pyogenes▿

    PubMed Central

    Rosch, Jason W.; Hsu, Fong Fu; Caparon, Michael G.

    2007-01-01

    The ExPortal of Streptococcus pyogenes is a membrane microdomain dedicated to the secretion and folding of proteins. We investigated the lipid composition of the ExPortal by examining the distribution of anionic membrane phospholipids. Staining with 10-N-nonyl-acridine orange revealed a single microdomain enriched with an anionic phospholipid whose staining characteristics and behavior in a cardiolipin-deficient mutant were characteristic of phosphatidylglycerol. Furthermore, the location of the microdomain corresponded to the site of active protein secretion at the ExPortal. These results indicate that the ExPortal is an asymmetric lipid microdomain, whose enriched content of anionic phospholipids may play an important role in ExPortal organization and protein trafficking. PMID:17142392

  11. Molecular Characterization of Invasive Streptococcus dysgalactiae subsp. equisimilis, Japan

    PubMed Central

    Wajima, Takeaki; Morozumi, Miyuki; Hanada, Shigeo; Sunaoshi, Katsuhiko; Chiba, Naoko; Iwata, Satoshi

    2016-01-01

    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. PMID:26760778

  12. Childhood pyogenic meningitis: clinical and investigative indicators of etiology and outcome.

    PubMed

    Johnson, Abdul-Wahab B R; Adedoyin, Olanrewaju T; Abdul-Karim, Aishat A; Olanrewaju, Abdul-Waheed I

    2007-08-01

    The relevant parameters of 71 consecutive pediatric admissions for pyogenic meningitis at the University of Ilorin Teaching Hospital, Ilorin, Nigeria, were analyzed to identify possible clinical and nonmicrobiologic investigative clues of disease etiology and mortality. Cerebrospinal fluid (CSF) was Gram-smear positive (GSP) in 41 (57.6%) of the 71 cases. Twenty-three (56.1%) had Gram-positive cocci (GPC), 14 (34.2%) Gram-negative bacilli (GNB) and three (7.3%) Gram-negative diplococci (GND). The respective mean ages of GPC, GNB and GND cases were 4.49 +/- 5.3, 3.06 +/- 4.8 and 4.47 +/-4.9 years. Streptococcus pneumoniae accounted for 22 (78.6%) of the 28 CSF isolates (p=0.00), Haemophilus influenzae for two (7.1%) cases and Neisseria meningitides in one (3.5%). Anemia was significantly more common among GSP cases (p=0.04), as was convulsion among those with GNB-positive smears (p=0.03) and a bulging fontanelle in the Gram-smear-negative category. Otherwise, the prevalence and resolution times of the other clinical parameters were comparable across the etiological categories. There were 30 deaths (42.3%) among which GNB-positive cases had significantly shorter stay (p=0.045). Mortality was significantly higher in those with an abnormal respiratory rhythm at admission (p=0.04), purulent/turbid CSF (p=0.03), CSF protein of >150 mg/dl (p=0.02) and glucose <1 mg/dl (p=0.047). Our findings highlight the inherent limitations of predicting the etiology of pediatric meningitides from the clinical parameters as well as the poor prognostic import of respiratory dysrhythmia and a profoundly deranged CSF protein and glucose. The etiological burden of GPC/S. pneumoniae in childhood meningitides in sub-Saharan Africa, the propensity of GNB/H. influenzae for quick fatality and the need for the relevant preventive vaccines are expounded in the discussion. PMID:17722674

  13. Childhood pyogenic meningitis: clinical and investigative indicators of etiology and outcome.

    PubMed Central

    Johnson, Abdul-Wahab B. R.; Adedoyin, Olanrewaju T.; Abdul-Karim, Aishat A.; Olanrewaju, Abdul-Waheed I.

    2007-01-01

    The relevant parameters of 71 consecutive pediatric admissions for pyogenic meningitis at the University of Ilorin Teaching Hospital, Ilorin, Nigeria, were analyzed to identify possible clinical and nonmicrobiologic investigative clues of disease etiology and mortality. Cerebrospinal fluid (CSF) was Gram-smear positive (GSP) in 41 (57.6%) of the 71 cases. Twenty-three (56.1%) had Gram-positive cocci (GPC), 14 (34.2%) Gram-negative bacilli (GNB) and three (7.3%) Gram-negative diplococci (GND). The respective mean ages of GPC, GNB and GND cases were 4.49 +/- 5.3, 3.06 +/- 4.8 and 4.47 +/-4.9 years. Streptococcus pneumoniae accounted for 22 (78.6%) of the 28 CSF isolates (p=0.00), Haemophilus influenzae for two (7.1%) cases and Neisseria meningitides in one (3.5%). Anemia was significantly more common among GSP cases (p=0.04), as was convulsion among those with GNB-positive smears (p=0.03) and a bulging fontanelle in the Gram-smear-negative category. Otherwise, the prevalence and resolution times of the other clinical parameters were comparable across the etiological categories. There were 30 deaths (42.3%) among which GNB-positive cases had significantly shorter stay (p=0.045). Mortality was significantly higher in those with an abnormal respiratory rhythm at admission (p=0.04), purulent/turbid CSF (p=0.03), CSF protein of >150 mg/dl (p=0.02) and glucose <1 mg/dl (p=0.047). Our findings highlight the inherent limitations of predicting the etiology of pediatric meningitides from the clinical parameters as well as the poor prognostic import of respiratory dysrhythmia and a profoundly deranged CSF protein and glucose. The etiological burden of GPC/S. pneumoniae in childhood meningitides in sub-Saharan Africa, the propensity of GNB/H. influenzae for quick fatality and the need for the relevant preventive vaccines are expounded in the discussion. PMID:17722674

  14. The association between varicella (chickenpox) and group A streptococcus infections in historical perspective

    PubMed Central

    Coleman, Stephen

    2016-01-01

    Objectives: The aim of the research is to investigate the historical relationship between varicella and Streptococcus pyogenes infections. In the past few decades, varicella has been identified as a risk factor for invasive group A streptococcus infections. The question is whether this relationship also existed between varicella and scarlet fever in the historical era. Methods: The analysis begins with a search of historical medical reports on the relationship between varicella and scarlet fever epidemics in the late 19th and early 20th century, as well as in more recent empirical studies. Correlations and cross-correlations between varicella and scarlet fever are analyzed using weekly public health case reports from 1924 to 1932 for Boston, Chicago, New York City, and Philadelphia. Regression models are used to estimate the relationship between varicella and scarlet fever after controlling for seasonal forcing. Results: Historical records give limited support for a causal relationship between varicella and scarlet fever but indicate that these diseases often occurred close in time to each other. Likewise, statistical analysis shows that varicella and scarlet fever epidemics are closely aligned with each other, and varicella has a strong relationship with scarlet fever. The relationship is stronger than reported in any previous research on the two diseases. Conclusion: The close correspondence of the two diseases likely depends on multiple factors, including seasonal forcing, a causal relationship, and co-infections. The results raise questions about whether this close relationship might have had a synergistic effect or a role in the evolution of S. pyogenes from the virulent, high incidence epidemics of the 19th century to the relatively benign scarlet fever of the 1950s. PMID:27504182

  15. Pyogenic granuloma on the tongue: a pediatric case report.

    PubMed

    Ximenes, Marcos; Triches, Thaisa C; Cardoso, Mariane; Bolan, Michele

    2013-08-01

    Pyogenic granuloma (PG) is a rare, benign, vascular, hyperplasic, soft tissue lesion caused by diverse factors, including traumatic injuries. This article presents a case involving the surgical removal of PG on the tongue of a 4-year-old boy who had difficulty with speech and eating because of the tongue lesion. The parents reported that the child had the habit of nibbling on and sucking his tongue. The lesion was excised and histopathological analysis confirmed the diagnosis of PG; however, because the child continued to nibble and suck on his tongue, the lesion recurred. A second surgery was performed with the same histopathological diagnosis. At a one-year follow-up, the child had ceased his tongue habits, and no recurrence was seen. PMID:23928434

  16. Alternative Therapeutic Approach in the Treatment of Oral Pyogenic Granuloma

    PubMed Central

    Bugshan, Amr; Patel, Harsh; Garber, Karen; Meiller, Timothy F.

    2015-01-01

    Pyogenic granulomas (PGs) in the oral cavity present as an inflammatory hyperplasia usually caused by trauma, hormonal imbalance, chronic irritation, or as the response to a wide variety of drugs. PGs with atypical presentation and behavior may clinically mimic malignant tumors. Thus, histological examination is required to rule out cancer development. Lesions in the oral cavity have been described to be either an isolated entity or present in multiple forms and with multiple recurrences. Conservative surgical excision is the standard choice of treatment in almost every scenario. However, the severity of the lesions and the affected sites often challenge surgical treatment. In this report, we describe the clinical scenario of a recurrent PG, where surgical excision of the lesion was questioned. As an alternative, we describe a noninvasive approach with lesional steroid injections. PMID:26668570

  17. Development of pyogenic granuloma and hemangioma after placement of dental implants: A review of literature

    PubMed Central

    Al-Shamiri, Hashem Motahir; Alaizari, Nader Ahmed; Al-Maweri, Sadeq Ali; Tarakji, Bassel

    2015-01-01

    Aim: The aim of this study is to highlight the development of pyogenic granuloma and hemangioma after the placement of dental implants. Materials and Methods: A literature search was performed using MEDLINE, accessed via the National Library of Medicine PubMed Interface, for articles published between 2000 and 2014 in English, relating to the occurrence of pyogenic granuloma or hemangioma in relation to dental implants. Results: Our search identified only four case reports of pyogenic granuloma and hemangioma related to dental implants as reported in the English literature. Conclusion: Placement of dental implants can cause development of pyogenic granuloma and hemangioma, indicating that placement of dental implants requires well-trained specialists with perfect skills in dental implantology. Furthermore, the critical selection of the appropriate case is of paramount importance to avoid the occurrence of such complications. PMID:25992330

  18. Adherence of Veillonella Species Mediated by Extracellular Glucosyltransferase from Streptococcus salivarius

    PubMed Central

    McCabe, R. M.; Donkersloot, J. A.

    1977-01-01

    The effect of extracellular products from Streptococcus salivarius on sucrose-dependent adherence to smooth surfaces by other oral bacteria was studied in vitro. Strains of Streptococcus mitis, Streptococcus pyogenes, and Veillonella parvula without innate ability to adhere to a steel wire were able to do so when incubated with sucrose and cell-free culture fluid from S. salivarius strains 9759, 25975, CNII, and MEPI. These culture fluids synthesized more adherent material and water-insoluble glucan than those from Streptococcus mutans C67-1 and seven other S. salivarius strains. Among the S. salivarius strains, glucosyltransferase (GT; dextransucrase, EC 2.4.1.5) activity varied more than 100-fold. Cells of Veillonella and S. mitis S3 that had been incubated in culture fluids from S. salivarius 25975 and 9759, respectively, and then washed adhered upon subsequent incubation with sucrose. This was due to adsorbed GT because (i) the adherence was sensitive to dextranase; (ii) it was observed only with the high-GT culture fluids; (iii) it was dependent on sucrose; and (iv) the washed Veillonella cells synthesized glucan, but not fructan, from sucrose. These results suggest that sucrose-dependent adherence of bacteria without such innate ability can be mediated by (i) entrapment in insoluble glucan synthesized by S. salivarius culture fluids, and (ii) prior adsorption of GT from S. salivarius culture fluids. The possibility that GT formed by high-yield strains of S. salivarius is distributed through the mouth by the action of salivary flow and contributes to sucrose-dependent adherence and plaque formation is considered. Images PMID:591064

  19. Clinical Characteristics and Risk Factors of Pyogenic Spondylitis Caused by Gram-Negative Bacteria

    PubMed Central

    Kang, Seung-Ji; Jang, Hee-Chang; Jung, Sook-In; Choe, Pyoeng Gyun; Park, Wan Beom; Kim, Chung-Jong; Song, Kyoung-Ho; Kim, Eu Suk; Kim, Hong Bin; Oh, Myoung-don

    2015-01-01

    Background There are limited data describing the clinical characteristics of pyogenic spondylitis caused by Gram-negative bacteria (GNB). The aim of this study was to investigate the predisposing factors and clinical characteristics of pyogenic spondylitis caused by GNB compared to Gram-positive cocci (GPC). Methods We performed a retrospective review of medical records from patients with culture-confirmed pyogenic spondylitis at four tertiary teaching hospitals over an 8-year period. Results A total of 344 patients with culture-confirmed pyogenic spondylitis were evaluated. There were 62 patients (18.0%) with pyogenic spondylitis caused by GNB and the most common organism was Escherichia coli (n = 35, 10.2%), followed by Pseudomonas aeruginosa (n = 10, 2.9%). Pyogenic spondylitis caused by GNB was more frequently associated with the female gender (64.5 vs. 35.5%, P <0.01), preexisting or synchronous genitourinary tract infection (32.3 vs. 2.1%, P< 0.01), and intra-abdominal infection (12.9 vs. 0.4%, P< 0.01) compared to patients with GPC. Although pyogenic spondylitis caused by GNB presented with severe sepsis more frequently (24.2 vs. 11.3%, P = 0.01), the mortality rate (6.0 vs. 5.2%) and the proportion of patients with residual disability (6.0 vs. 9.0%), defined as grade 3 or 4 (P = 0.78) 3 months after completion of treatment, were not significantly different compared to GPC patients. Conclusion GNB should be considered as the etiologic organism when infectious spondylitis develops in a patient with preexisting or synchronous genitourinary tract and intra-abdominal infection. In addition, the mortality rate and clinical outcomes are not significantly different between pyogenic spondylitis caused by GNB and GPC. PMID:25978839

  20. Pyogenic granuloma: case report in a 9-year-old girl.

    PubMed

    Ramirez, Katalina; Bruce, Gretchen; Carpenter, William

    2002-01-01

    Based on clinical features alone, pyogenic granuloma can be difficult to differentiate from a peripheral giant cell granuloma, a more aggressive oral lesion that could have consequences such as teeth displacement and alveolar bone resorption. A thorough clinical and radiographic examination is important to determine whether teeth and/or bone are involved. Furthermore, the early onset of puberty in females may increase the prevalence of pyogenic granuloma at a young age. PMID:12116517

  1. An exaggerated response of intra-oral pyogenic granuloma during puberty.

    PubMed

    Papageorge, M B; Doku, H C

    1992-01-01

    Intra-oral pyogenic granulomas have been associated with pregnancy. The exaggerated response of these tumors has been related to the hormonal changes occurring during this period. A change in the hormonal balance also occurs during puberty. In this paper, we present two young patients with large pyogenic granulomas and suggest that the hormonal changes play a primary role in the pathogenesis of this tumor. PMID:1525077

  2. Cloning, expression, and characterization of a neuraminidase gene from Arcanobacterium pyogenes.

    PubMed

    Jost, B H; Songer, J G; Billington, S J

    2001-07-01

    Arcanobacterium pyogenes is an opportunistic pathogen, associated with suppurative infections in domestic animals. In addition to pyolysin, a pore-forming, cholesterol-binding toxin, A. pyogenes expresses a number of putative virulence factors, including several proteases and neuraminidase activity. A 3,009-bp gene, nanH, was cloned and sequenced and conferred neuraminidase activity on an Escherichia coli host strain. The predicted 107-kDa NanH protein displayed similarity to a number of bacterial neuraminidases and contained the RIP/RLP motif and five copies of the Asp box motif found in all bacterial neuraminidases. Recombinant His-tagged NanH was found to have pH and temperature optima of 5.5 to 6.0 and 55 degrees C, respectively. Insertional deletion of the nanH gene resulted in the reduction, but not absence, of neuraminidase activity, indicating the presence of a second neuraminidase gene in A. pyogenes. NanH was localized to the A. pyogenes cell wall. A. pyogenes adhered to HeLa, CHO, and MDBK cells in a washing-resistant manner. However, the nanH mutant was not defective for adherence to epithelial cells. The role of NanH in host epithelial cell adherence may be masked by the presence of a second neuraminidase in A. pyogenes. PMID:11401983

  3. 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

    2016-04-01

    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

  4. Multilocus Sequence Analysis of Streptococcus canis Confirms the Zoonotic Origin of Human Infections and Reveals Genetic Exchange with Streptococcus dysgalactiae subsp. equisimilis

    PubMed Central

    Pinho, M. D.; Matos, S. C.; Pomba, C.; Lübke-Becker, A.; Wieler, L. H.; Preziuso, S.; Melo-Cristino, J.

    2013-01-01

    Streptococcus canis is an animal pathogen that occasionally causes human infections. Isolates recovered from infections of animals (n = 78, recovered from 2000 to 2010 in three European countries, mainly from house pets) and humans (n = 7, recovered from 2006 to 2010 in Portugal) were identified by phenotypic and genotypic methods and characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and emm typing. S. canis isolates presented considerable variability in biochemical profiles and 16S rRNA. Resistance to antimicrobial agents was low, with the most significant being tet(M)- and tet(O)-mediated tetracycline resistance. MLST analysis revealed a polyclonal structure of the S. canis population causing infections, where the same genetic lineages were found infecting house pets and humans and were disseminated in distinct geographic locations. Phylogenetic analysis indicated that S. canis was a divergent taxon of the sister species Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis and found evidence of acquisition of genetic material by S. canis from S. dysgalactiae subsp. equisimilis. PFGE confirmed the MLST findings, further strengthening the similarity between animal and human isolates. The presence of emm-like genes was restricted to a few isolates and correlated with some MLST-based genetic lineages, but none of the human isolates could be emm typed. Our data show that S. canis isolates recovered from house pets and humans constitute a single population and demonstrate that isolates belonging to the main genetic lineages identified have the ability to infect the human host, providing strong evidence for the zoonotic nature of S. canis infection. PMID:23345291

  5. Lysates of S. pyogenes serotype M49 induce pancreatic tumor growth delay by specific and unspecific antitumor immune responses.

    PubMed

    Linnebacher, Michael; Maletzki, Claudia; Emmrich, Jörg; Kreikemeyer, Bernd

    2008-10-01

    Treatment of pancreatic cancer by active unspecific bacterial immunotherapy is a promising new strategy. Recently, we showed that a single intratumoral injection of wildtype Streptococcus pyogenes M49 results in complete regression of pancreatic carcinoma in mice mediated both by unspecific cytotoxicity and by specific immune reactions against tumor cells. As for potential clinical use, conditioning and especially inactivation of bacteria would abolish the risk of systemic bacterial infections; we here explored the potential of a streptococcal lysate prepared by bacteriophage lysine to affect pancreatic carcinoma growth in vivo. Application of the lysate into established Panc02 tumors resulted in pronounced growth cessation accompanied by raises in levels of circulating monocytes, granulocytes, and natural killer cells. Detailed analysis of splenocyte subsets revealed lysate-induced transient increases in pre-B cells followed by raised levels of activated T cells. Moreover, blood levels of proinflammatory, T helper-1-type cytokines were significantly elevated. These systemic immunologic effects were accompanied by massive infiltrations of cytotoxic T cells into the tumors. Concomitantly, lymphocytes obtained from treated mice specifically recognized Panc02 tumor cells in IFN-gamma-enzyme-linked immunosorbent spot and in cellular cytotoxicity assays. In rechallenge experiments, these immunologic effector cells were found to delay, but not completely prevent growth of secondary tumors. However, when considering the notoriously depressed immune status of individuals suffering from pancreatic carcinoma, the orchestrated antitumoral immune responses we analyzed here in detail significantly strengthen the potential usefulness of microbial compounds as active unspecific immunotherapeutic agent for treatment of pancreatic carcinoma. PMID:18779749

  6. Tylosin resistance in Arcanobacterium pyogenes is encoded by an erm X determinant.

    PubMed

    Jost, B Helen; Field, Adam C; Trinh, Hien T; Songer, J Glenn; Billington, Stephen J

    2003-11-01

    Arcanobacterium pyogenes, a commensal on the mucous membranes of many economically important animal species, is also a pathogen, causing abscesses of the skin, joints, and visceral organs as well as mastitis and abortion. In food animals, A. pyogenes is exposed to antimicrobial agents used for growth promotion, prophylaxis, and therapy, notably tylosin, a macrolide antibiotic used extensively for the prevention of liver abscessation in feedlot cattle in the United States. Of 48 A. pyogenes isolates, 11 (22.9%) exhibited inducible or constitutive resistance to tylosin (MIC of > or = 128 microg/ml). These isolates also exhibited resistance to other macrolide and lincosamide antibiotics, suggesting a macrolide-lincosamide resistance phenotype. Of the 11 resistant isolates, genomic DNA from nine hybridized to an erm(X)-specific probe. Cloning and nucleotide sequencing of the A. pyogenes erm(X) gene indicated that it was >95% similar to erm(X) genes from Corynebacterium and Propionibacterium spp. Eight of the erm(X)-containing A. pyogenes isolates exhibited inducible tylosin resistance, which was consistent with the presence of a putative leader peptide upstream of the erm(X) open reading frame. For at least one A. pyogenes isolate, 98-4277-2, erm(X) was present on a plasmid, pAP2, and was associated with the insertion sequence IS6100. pAP2 also carried genes encoding the repressor-regulated tetracycline efflux system determinant Tet 33. The repA gene from pAP2 was nonfunctional in Escherichia coli and at least one A. pyogenes isolate, suggesting that there may be host-encoded factors required for replication of this plasmid. PMID:14576111

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  8. Pyogenic Granuloma: Surgical Treatment with Er:YAG Laser

    PubMed Central

    Fekrazad, Reza; Nokhbatolfoghahaei, Hanieh; Khoei, Farzaneh; Kalhori, Katayoun AM

    2014-01-01

    Introduction: Pyogenic granuloma (PG) is a common tumor-like growth of the oral cavity, considered to be of non-neoplastic nature, often caused by constant low-grade trauma as well as poor oral hygiene and maybe due to hormonal disturbances. Surgical excision, and removal of underlying cause in some cases, is the preferred method of treatment as it is only a benign lesion.In order to remove this lesion, scalpel, cryosurgery and laser are used. Currently different lasers, with adequate parameters, are used for the surgery of PG, which include CO2 (Carbon Dioxide Laser), Nd:YAG (Neodymium-Doped Yttrium Aluminium Garnet), Diode and Er Family amongst others. In this present case, due to the proximity of the lesion with dental hard tissue, Er:YAG (Erbium-Doped Yttrium Aluminum Garnet) laser appears to be the more appropriate laser. The application of Laser is also a newly recommended technique. The aim of this study is to assess the stages of treatment, recovery and recurrence of PG when the Er:YAG laser is used. Furthermore this study aims to also evaluate the friendliness of this method with regards to the surgeon (therapist). Case report: A 24-year-old female was referred to the Laser Research Center of Dentistry of Tehran University of Medical Sciences with a complaint of gingival overgrowth and bleeding. This lesion was in the buccal and palatal side of the 5 and 6 maxillary teeth. Treatment plan included an excisional biopsy of the lesion using Er:YAG laser (3W, 300mJ, 10Hz, Short pulse, with contact headpiece). The bones were then cleaned of soft tissue before being smoothed using a curette. The excised specimen was preserved and sent for histopathological examination. Results: The patient reported no pain after surgery and did not use any systemic antibiotics. The patient was satisfied after the surgery. Chlorhexidine mouthwash was given to the patient. Pathology results confirmed Pyogenic granuloma.After 2 weeks, complete healing was observed. The 9-month

  9. Highly Effective Renaturation of a Streptokinase from Streptococcus pyogenes DT7 as Inclusion Bodies Overexpressed in Escherichia coli

    PubMed Central

    Nguyen, Sy Le Thanh; Quyen, Dinh Thi; Vu, Hong Diep

    2014-01-01

    The streptokinase (SK) is emerging as an important thrombolytic therapy agent in the treatment of patients suffering from cardiovascular diseases. We reported highly effective renaturation of a SK from S. pyogeness DT7 overexpressed in E. coli, purification, and biochemical characterization. A gene coding for the SK was cloned from S. pyogeness DT7. Because accumulation of active SK is toxic to the host cells, we have expressed it in the form of inclusion bodies. The mature protein was overexpressed in E. coli BL21 DE3/pESK under the control of the strong promoter tac induced by IPTG with a level of 60% of the total cell proteins. The activity of the rSK, renatured in phosphate buffer supplemented with Triton X-100 and glycerol, was covered with up to 41 folds of its initial activity. The purified of protein was identified with MALDI-TOF mass spectrometry through four peptide fragments, which showed 100% identification to the corresponding peptides of the putative SK from GenBank. Due to overexpression and highly effective renaturation of large amounts of inclusion bodies, the recombinant E. coli BL21 DE3/pESK system could be potentially applied for large-scale production of SK used in the therapy of acute myocardial infarction. PMID:24883307

  10. Staphylococcus aureus toxic shock syndrome toxin 1 and Streptococcus pyogenes erythrogenic toxin A modulate inflammatory mediator release from human neutrophils.

    PubMed Central

    Hensler, T; Köller, M; Geoffroy, C; Alouf, J E; König, W

    1993-01-01

    We studied the influence of staphylococcal toxic shock syndrome toxin 1 and streptococcal erythrogenic (pyrogenic) toxin A (ETA) on intact and digitonin-permeabilized human polymorphonuclear granulocytes (PMNs). As was shown by reversed-phase high-performance liquid chromatography analysis, toxic shock syndrome toxin 1 or ETA alone, in the absence of any additional stimulus, did not induce the generation of the chemoattractant leukotriene B4 (LTB4) from PMNs in a wide range of concentrations. In addition, pretreatment of intact PMNs with either toxin potentiated formyl-methionyl-leucyl-phenylalanine (fMLP)- and washed Staphylococcus aureus cell-induced generation of LTB4 in a time- and dose-dependent manner. This increase included LTB4 as well as its inactive omega-oxidated compounds. Further studies revealed evidence that toxin exposure was accompanied by enhanced cellular receptor expression for fMLP as well as for LTB4. The intrinsic GTPase activity of membrane fractions was modulated by both toxins. Short-term incubation with ETA increased the GTPase activity of PMNs up to 141%. Inhibitory effects were obtained when GTP-binding protein functions were stimulated with sodium fluoride (NaF). In addition, specific binding of Gpp(NH)p to GTP-binding protein was inhibited by both toxins during the first 10 min of incubation and was restored at later times of incubation. Our data therefore suggest that both toxins significantly affect the signal transduction pathways of human PMNs, which results in immunomodulatory functions. PMID:8381770

  11. Staphylococcus aureus toxic shock syndrome toxin 1 and Streptococcus pyogenes erythrogenic toxin A modulate inflammatory mediator release from human neutrophils.

    PubMed

    Hensler, T; Köller, M; Geoffroy, C; Alouf, J E; König, W

    1993-03-01

    We studied the influence of staphylococcal toxic shock syndrome toxin 1 and streptococcal erythrogenic (pyrogenic) toxin A (ETA) on intact and digitonin-permeabilized human polymorphonuclear granulocytes (PMNs). As was shown by reversed-phase high-performance liquid chromatography analysis, toxic shock syndrome toxin 1 or ETA alone, in the absence of any additional stimulus, did not induce the generation of the chemoattractant leukotriene B4 (LTB4) from PMNs in a wide range of concentrations. In addition, pretreatment of intact PMNs with either toxin potentiated formyl-methionyl-leucyl-phenylalanine (fMLP)- and washed Staphylococcus aureus cell-induced generation of LTB4 in a time- and dose-dependent manner. This increase included LTB4 as well as its inactive omega-oxidated compounds. Further studies revealed evidence that toxin exposure was accompanied by enhanced cellular receptor expression for fMLP as well as for LTB4. The intrinsic GTPase activity of membrane fractions was modulated by both toxins. Short-term incubation with ETA increased the GTPase activity of PMNs up to 141%. Inhibitory effects were obtained when GTP-binding protein functions were stimulated with sodium fluoride (NaF). In addition, specific binding of Gpp(NH)p to GTP-binding protein was inhibited by both toxins during the first 10 min of incubation and was restored at later times of incubation. Our data therefore suggest that both toxins significantly affect the signal transduction pathways of human PMNs, which results in immunomodulatory functions. PMID:8381770

  12. Consequences of the variability of the CovRS and RopB regulators among Streptococcus pyogenes causing human infections

    PubMed Central

    Friães, Ana; Pato, Catarina; Melo-Cristino, José; Ramirez, Mario

    2015-01-01

    To evaluate the importance of covRS and ropB mutations in invasive disease caused by Group A Streptococci (GAS), we determined the sequence of the covRS and ropB genes of 191 isolates from invasive infections and pharyngitis, comprising a diverse set of emm types and multilocus sequence types. The production of SpeB and the activity of NAD glycohydrolase (NADase) and streptolysin S (SLS) were evaluated. The results support the acquisition of null covS alleles (predicted to eliminate protein function), resulting in downregulation of SpeB and upregulation of NADase and SLS, as a mechanism possibly contributing to higher invasiveness. Among the isolates tested, this mechanism was found to be uncommon (10% of invasive isolates) and was not more prevalent among clones with enhanced invasiveness (including M1T1) but occurred in diverse genetic backgrounds. In lineages such as emm64, these changes did not result in upregulation of NADase and SLS, highlighting the diversity of regulatory pathways in GAS. Despite abrogating SpeB production, null alleles in ropB were not associated with invasive infection. The covRS and ropB genes are under stabilising selection and no expansion of isolates carrying null alleles has been observed, suggesting that the presence of these regulators is important for overall fitness. PMID:26174161

  13. Characterization of a two-component system in Streptococcus pyogenes which is involved in regulation of hyaluronic acid production.

    PubMed

    Bernish, B; van de Rijn, I

    1999-02-19

    Hyaluronic acid production by group A streptococci is regulated by transcriptional control. In this study, transposon mutagenesis of an unencapsulated strain yielded an encapsulated mutant. Two genes homologous to sensors and response regulators of bacterial two-component systems were identified downstream of the transposon insertion. Inactivation of the putative sensor gene, csrS, in three different unencapsulated strains yielded encapsulated mutant strains. Electrophoretic mobility shift assays determined factor(s) in a cytoplasmic extract of an unencapsulated group A streptococcal strain was binding to a double-stranded DNA fragment derived from the has operon promoter. In contrast, similarly prepared cytoplasmic extracts from a csrS deletion mutant did not shift the fragment. The putative response regulator, CsrR, was partially purified and was shown to bind the has operon promoter fragment. The affinity and specificity of CsrR for the fragment were increased significantly after incubation with acetyl phosphate. DNase I footprinting determined that the acetyl phosphate-treated CsrR was binding to key sequences in the promoter and the coding region of hasA. Therefore, a two-component system is repressing the production of hyaluronic acid in group A streptococci using a phosphorylation-dependent binding interaction between the response regulator CsrR and the promoter region of the has operon. PMID:9988717

  14. Bacteriophage enzymes for the prevention and treatment of bacterial infections: Stability and stabilization of the enzyme lysing Streptococcus pyogenes cells

    SciTech Connect

    Klyachko, N. L.; Dmitrieva, N. F.; Eshchina, A. S.; Ignatenko, O. V.; Filatova, L. Y.; Rainina, Evguenia I.; Kazarov, A. K.; Levashov, A. V.

    2008-06-01

    Recombinant, phage associated lytic enzyme Ply C capable to lyse streptococci of groups A and C was stabilized in the variety of the micelles containing compositions to improve the stability of the enzyme for further application in medicine. It was shown that, in the micellar polyelectrolyte composition M16, the enzyme retained its activity for 2 months; while in a buffer solution under the same conditions ((pH 6.3, room temperature), it completely lost its activity in 2 days

  15. 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

  16. Expression, genetic localization and phylogenic analysis of NAPlr in piscine Streptococcus dysgalactiae subspecies dysgalactiae isolates and their patterns of adherence

    PubMed Central

    Abdelsalam, M.; Fujino, M.; Eissa, A.E.; Chen, S.C.; Warda, M.

    2014-01-01

    Streptococcus dysgalactiae, the long recognized mammalian pathogen, has currently received a major concern regarding fish bacterial infection. Adhesion to host epithelial cells and the presence of wall-associated plasminogen binding proteins are prerequisites to Streptococcus infection. This is the first study of the occurrence of nephritis-associated plasminogen-binding receptor (NAPlr) and α-enolase genes in piscine S. dysgalactiae subspecies dysgalactiae (SDSD) isolates. Further characterization of surface localized NAPlr of fish SDSD revealed a similar immune-reactive band of 43 KDa as that from porcine S. dysgalactiae subsp. equisimilis (SDSE). The phylogenetic analysis revealed that NAPlr of fish SDSD is more associated with those of mammalian SDSE and Streptococcus pyogenes rather than of other streptococci. Our findings warrant public attention to the possible implication of these virulence genes in dissemination of SDSD to different tissues of infected hosts and to get advantage to new niches. The SDSD adherence patterns were also studied to better understand their pathogenicity. The patterns of adherence of SDSD on two different cell lines showed a different pattern of adherence. Such difference gives an insight about the variance in host susceptibility to infection. PMID:26425363

  17. Streptococcus thermophilus CRISPR-Cas9 Systems Enable Specific Editing of the Human Genome.

    PubMed

    Müller, Maximilian; Lee, Ciaran M; Gasiunas, Giedrius; Davis, Timothy H; Cradick, Thomas J; Siksnys, Virginijus; Bao, Gang; Cathomen, Toni; Mussolino, Claudio

    2016-03-01

    RNA-guided nucleases (RGNs) based on the type II CRISPR-Cas9 system of Streptococcus pyogenes (Sp) have been widely used for genome editing in experimental models. However, the nontrivial level of off-target activity reported in several human cells may hamper clinical translation. RGN specificity depends on both the guide RNA (gRNA) and the protospacer adjacent motif (PAM) recognized by the Cas9 protein. We hypothesized that more stringent PAM requirements reduce the occurrence of off-target mutagenesis. To test this postulation, we generated RGNs based on two Streptococcus thermophilus (St) Cas9 proteins, which recognize longer PAMs, and performed a side-by-side comparison of the three RGN systems targeted to matching sites in two endogenous human loci, PRKDC and CARD11. Our results demonstrate that in samples with comparable on-target cleavage activities, significantly lower off-target mutagenesis was detected using St-based RGNs as compared to the standard Sp-RGNs. Moreover, similarly to SpCas9, the StCas9 proteins accepted truncated gRNAs, suggesting that the specificities of St-based RGNs can be further improved. In conclusion, our results show that Cas9 proteins with longer or more restrictive PAM requirements provide a safe alternative to SpCas9-based RGNs and hence a valuable option for future human gene therapy applications. PMID:26658966

  18. Streptococcus intermedius Bacteremia and Liver Abscess following a Routine Dental Cleaning

    PubMed Central

    Livingston, Lachara V.; Perez-Colon, Elimarys

    2014-01-01

    Streptococcus intermedius is a member of the Streptococcus anginosus group of bacteria. This group is part of the normal flora of the oropharynx, genitourinary, and gastrointestinal tracts; however, they have been known to cause a variety of purulent infections including meningitis, endocarditis, and abscesses, even in immunocompetent hosts. In particular, S. intermedius has been associated with the development of liver and brain abscesses. There have been several case reports of S. intermedius liver abscesses with active periodontal infection. To our knowledge, however, there has not been a case following a routine dental procedure. In fact, the development of liver abscesses secondary to dental procedures is very rare in general, and there are only a few case reports in the literature describing this in relation to any pathogen. We present a rare case of S. intermedius bacteremia and liver abscess following a dental cleaning. This case serves to further emphasize that even routine dental procedures can place a patient at risk of the development of bacteremia and liver abscesses. For this reason, the clinician must be sure to perform a detailed history and careful examination. Timely diagnosis of pyogenic liver abscesses is vital, as they are typically fatal if left untreated. PMID:25197585

  19. Outbreak of Group A beta hemolytic Streptococcus pharyngitis in a Peruvian military facility, April 2012.

    PubMed

    Ramos, Mariana; Valle, Ruben; Reaves, Eric J; Loayza, Luis; Gonzalez, Sofia; Bernal, Maria; Soto, Giselle; Hawksworth, Anthony W; Kasper, Matthew R; Tilley, Drake H; De Mattos, Carlos A; Brown, Jason R; Bausch, David G

    2013-06-01

    Group A Streptococcus (GAS), or Streptococcus pyogenes, is a common cause of acute pharyngitis as well as other diseases. Closed populations such as those living on military bases, nursing homes, and prisons are particularly vulnerable to GAS outbreaks due to crowding that facilitates person-to-person transmission. This report details a large outbreak of GAS pharyngitis at a Peruvian military training facility near Lima, Peru, in April 2012. Initial findings showed 145 cases. However, as the investigation continued it was revealed that some trainees may have concealed their illness to avoid real or perceived negative consequences of seeking medical care. A subsequent anonymous survey of all trainees revealed at least 383 cases of pharyngitis among the facility's 1,549 trainees and an attack rate of 34 percent among the 1,137 respondents. The epidemic curve revealed a pattern consistent with routine person-to-person transmission, although a point-source initiating event could not be excluded. Laboratory results showed GAS emm type 80.1 to be the culprit pathogen, an organism not commonly implicated in outbreaks of GAS in the Americas. Barious unique and illustrative features of outbreak investigation in military facilities and populations are discussed. PMID:23819536

  20. Activation of band 3 mediates group A Streptococcus streptolysin S-based beta-haemolysis.

    PubMed

    Higashi, Dustin L; Biais, Nicolas; Donahue, Deborah L; Mayfield, Jeffrey A; Tessier, Charles R; Rodriguez, Kevin; Ashfeld, Brandon L; Luchetti, Jeffrey; Ploplis, Victoria A; Castellino, Francis J; Lee, Shaun W

    2016-01-01

    Streptococcus pyogenes, or group A Streptococcus (GAS), is a human bacterial pathogen that can manifest as a range of diseases from pharyngitis and impetigo to severe outcomes such as necrotizing fasciitis and toxic shock syndrome. GAS disease remains a global health burden with cases estimated at over 700 million annually and over half a million deaths due to severe infections(1). For over 100 years, a clinical hallmark of diagnosis has been the appearance of complete (beta) haemolysis when grown in the presence of blood. This activity is due to the production of a small peptide toxin by GAS known as streptolysin S. Although it has been widely held that streptolysin S exerts its lytic activity through membrane disruption, its exact mode of action has remained unknown. Here, we show, using high-resolution live cell imaging, that streptolysin S induces a dramatic osmotic change in red blood cells, leading to cell lysis. This osmotic change was characterized by the rapid influx of Cl(-) ions into the red blood cells through SLS-mediated disruption of the major erythrocyte anion exchange protein, band 3. Chemical inhibition of band 3 function significantly reduced the haemolytic activity of streptolysin S, and dramatically reduced the pathology in an in vivo skin model of GAS infection. These results provide key insights into the mechanism of streptolysin S-mediated haemolysis and have implications for the development of treatments against GAS. PMID:27571972

  1. Comparative genomics of the bacterial genus Streptococcus illuminates evolutionary implications of species groups.

    PubMed

    Gao, Xiao-Yang; Zhi, Xiao-Yang; Li, Hong-Wei; Klenk, Hans-Peter; Li, Wen-Jun

    2014-01-01

    Members of the genus Streptococcus within the phylum Firmicutes are among the most diverse and significant zoonotic pathogens. This genus has gone through considerable taxonomic revision due to increasing improvements of chemotaxonomic approaches, DNA hybridization and 16S rRNA gene sequencing. It is proposed to place the majority of streptococci into "species groups". However, the evolutionary implications of species groups are not clear presently. We use comparative genomic approaches to yield a better understanding of the evolution of Streptococcus through genome dynamics, population structure, phylogenies and virulence factor distribution of species groups. Genome dynamics analyses indicate that the pan-genome size increases with the addition of newly sequenced strains, while the core genome size decreases with sequential addition at the genus level and species group level. Population structure analysis reveals two distinct lineages, one including Pyogenic, Bovis, Mutans and Salivarius groups, and the other including Mitis, Anginosus and Unknown groups. Phylogenetic dendrograms show that species within the same species group cluster together, and infer two main clades in accordance with population structure analysis. Distribution of streptococcal virulence factors has no obvious patterns among the species groups; however, the evolution of some common virulence factors is congruous with the evolution of species groups, according to phylogenetic inference. We suggest that the proposed streptococcal species groups are reasonable from the viewpoints of comparative genomics; evolution of the genus is congruent with the individual evolutionary trajectories of different species groups. PMID:24977706

  2. Comparative Genomics of the Bacterial Genus Streptococcus Illuminates Evolutionary Implications of Species Groups

    PubMed Central

    Gao, Xiao-Yang; Zhi, Xiao-Yang; Li, Hong-Wei; Klenk, Hans-Peter; Li, Wen-Jun

    2014-01-01

    Members of the genus Streptococcus within the phylum Firmicutes are among the most diverse and significant zoonotic pathogens. This genus has gone through considerable taxonomic revision due to increasing improvements of chemotaxonomic approaches, DNA hybridization and 16S rRNA gene sequencing. It is proposed to place the majority of streptococci into “species groups”. However, the evolutionary implications of species groups are not clear presently. We use comparative genomic approaches to yield a better understanding of the evolution of Streptococcus through genome dynamics, population structure, phylogenies and virulence factor distribution of species groups. Genome dynamics analyses indicate that the pan-genome size increases with the addition of newly sequenced strains, while the core genome size decreases with sequential addition at the genus level and species group level. Population structure analysis reveals two distinct lineages, one including Pyogenic, Bovis, Mutans and Salivarius groups, and the other including Mitis, Anginosus and Unknown groups. Phylogenetic dendrograms show that species within the same species group cluster together, and infer two main clades in accordance with population structure analysis. Distribution of streptococcal virulence factors has no obvious patterns among the species groups; however, the evolution of some common virulence factors is congruous with the evolution of species groups, according to phylogenetic inference. We suggest that the proposed streptococcal species groups are reasonable from the viewpoints of comparative genomics; evolution of the genus is congruent with the individual evolutionary trajectories of different species groups. PMID:24977706

  3. Group A Streptococcus tissue invasion by CD44-mediated cell signalling

    NASA Astrophysics Data System (ADS)

    Cywes, Colette; Wessels, Michael R.

    2001-12-01

    Streptococcus pyogenes (also known as group A Streptococcus, GAS), the agent of streptococcal sore throat and invasive soft-tissue infections, attaches to human pharyngeal or skin epithelial cells through specific recognition of its hyaluronic acid capsular polysaccharide by the hyaluronic-acid-binding protein CD44 (refs 1, 2). Because ligation of CD44 by hyaluronic acid can induce epithelial cell movement on extracellular matrix, we investigated whether molecular mimicry by the GAS hyaluronic acid capsule might induce similar cellular responses. Here we show that CD44-dependent GAS binding to polarized monolayers of human keratinocytes induced marked cytoskeletal rearrangements manifested by membrane ruffling and disruption of intercellular junctions. Transduction of the signal induced by GAS binding to CD44 on the keratinocyte surface involved Rac1 and the cytoskeleton linker protein ezrin, as well as tyrosine phosphorylation of cellular proteins. Studies of bacterial translocation in two models of human skin indicated that cell signalling triggered by interaction of the GAS capsule with CD44 opened intercellular junctions and promoted tissue penetration by GAS through a paracellular route. These results support a model of host cytoskeleton manipulation and tissue invasion by an extracellular bacterial pathogen.

  4. Role of group A Streptococcus HtrA in the maturation of SpeB protease.

    PubMed

    Cole, Jason N; Aquilina, John A; Hains, Peter G; Henningham, Anna; Sriprakash, Kadaba S; Caparon, Michael G; Nizet, Victor; Kotb, Malak; Cordwell, Stuart J; Djordjevic, Steven P; Walker, Mark J

    2007-12-01

    The serine protease high-temperature requirement A (HtrA) (DegP) of the human pathogen Streptococcus pyogenes (group A Streptococcus; GAS) is localized to the ExPortal secretory microdomain and is reportedly essential for the maturation of cysteine protease streptococcal pyrogenic exotoxin B (SpeB). Here, we utilize HSC5 (M5 serotype) and the in-frame isogenic mutant HSC5DeltahtrA to determine whether HtrA contributes to the maturation of other GAS virulence determinants. Mutanolysin cell wall extracts and secreted proteins were arrayed by 2-DE and identified by MALDI-TOF PMF analysis. HSC5DeltahtrA had elevated levels of cell wall-associated M protein, whilst the supernatant had higher concentrations of M protein fragments and a reduced amount of mature SpeB protease, compared to wild-type (WT). Western blot analysis and protease assays revealed a delay in the maturation of SpeB in the HSC5DeltahtrA supernatant. HtrA was unable to directly process SpeB zymogen (proSpeB) to the active form in vitro. We therefore conclude that HtrA plays an indirect role in the maturation of cysteine protease SpeB. PMID:18072207

  5. The effect of ingestion of milk supplemented with salivaricin A-producing Streptococcus salivarius on the bacteriocin-like inhibitory activity of streptococcal populations on the tongue.

    PubMed

    Dierksen, Karen P; Moore, Chris J; Inglis, Megan; Wescombe, Philip A; Tagg, John R

    2007-03-01

    The colonization efficacies of salivaricin A (SalA)-producing Streptococcus salivarius strains 20P3 and 5 were compared when given in milk to 219 children, using either 2-day or 9-day dosing regimens. Colonization levels overall were superior for strain 5, and the 9-day dosing schedule resulted in higher levels of both initial colonization and strain persistence. The indigenous streptococcal tongue populations of 20 (10.9%) of the 189 children in the 2-day trial showed markedly increased SalA-like inhibitory activity following use of the S. salivarius-supplemented milk. All 20 of these children were found to have had relatively small (<5% of total S. salivarius) indigenous tongue populations of SalA-producing S. salivarius, and the relative proportions and/or inhibitory activity of these SalA producers on the childrens' tongues increased following ingestion of the S. salivarius-supplemented milk. Because SalA is known to be strongly inhibitory to Streptococcus pyogenes, an important implication of this study is that the consumption of SalA-producing probiotic S. salivarius could potentially help to effect a sustained increase in SalA-mediated protection against S. pyogenes infection. PMID:17069620

  6. A chemokine-degrading extracellular protease made by group A Streptococcus alters pathogenesis by enhancing evasion of the innate immune response.

    PubMed

    Sumby, Paul; Zhang, Shizhen; Whitney, Adeline R; Falugi, Fabiana; Grandi, Guido; Graviss, Edward A; Deleo, Frank R; Musser, James M

    2008-03-01

    Circumvention of the host innate immune response is critical for bacterial pathogens to infect and cause disease. Here we demonstrate that the group A Streptococcus (GAS; Streptococcus pyogenes) protease SpyCEP (S. pyogenes cell envelope protease) cleaves granulocyte chemotactic protein 2 (GCP-2) and growth-related oncogene alpha (GROalpha), two potent chemokines made abundantly in human tonsils. Cleavage of GCP-2 and GROalpha by SpyCEP abrogated their abilities to prime neutrophils for activation, detrimentally altering the innate immune response. SpyCEP expression is negatively regulated by the signal transduction system CovR/S. Purified recombinant CovR bound the spyCEP gene promoter region in vitro, indicating direct regulation. Immunoreactive SpyCEP protein was present in the culture supernatants of covR/S mutant GAS strains but not in supernatants from wild-type strains. However, wild-type GAS strains do express SpyCEP, where it is localized to the cell wall. Strain MGAS2221, an organism representative of the highly virulent and globally disseminated M1T1 GAS clone, differed significantly from its isogenic spyCEP mutant derivative strain in a mouse soft tissue infection model. Interestingly, and in contrast to previous studies, the isogenic mutant strain generated lesions of larger size than those formed following infection with the parent strain. The data indicate that SpyCEP contributes to GAS virulence in a strain- and disease-dependent manner. PMID:18174342

  7. A Chemokine-Degrading Extracellular Protease Made by Group A Streptococcus Alters Pathogenesis by Enhancing Evasion of the Innate Immune Response▿ †

    PubMed Central

    Sumby, Paul; Zhang, Shizhen; Whitney, Adeline R.; Falugi, Fabiana; Grandi, Guido; Graviss, Edward A.; DeLeo, Frank R.; Musser, James M.

    2008-01-01

    Circumvention of the host innate immune response is critical for bacterial pathogens to infect and cause disease. Here we demonstrate that the group A Streptococcus (GAS; Streptococcus pyogenes) protease SpyCEP (S. pyogenes cell envelope protease) cleaves granulocyte chemotactic protein 2 (GCP-2) and growth-related oncogene alpha (GROα), two potent chemokines made abundantly in human tonsils. Cleavage of GCP-2 and GROα by SpyCEP abrogated their abilities to prime neutrophils for activation, detrimentally altering the innate immune response. SpyCEP expression is negatively regulated by the signal transduction system CovR/S. Purified recombinant CovR bound the spyCEP gene promoter region in vitro, indicating direct regulation. Immunoreactive SpyCEP protein was present in the culture supernatants of covR/S mutant GAS strains but not in supernatants from wild-type strains. However, wild-type GAS strains do express SpyCEP, where it is localized to the cell wall. Strain MGAS2221, an organism representative of the highly virulent and globally disseminated M1T1 GAS clone, differed significantly from its isogenic spyCEP mutant derivative strain in a mouse soft tissue infection model. Interestingly, and in contrast to previous studies, the isogenic mutant strain generated lesions of larger size than those formed following infection with the parent strain. The data indicate that SpyCEP contributes to GAS virulence in a strain- and disease-dependent manner. PMID:18174342

  8. Pyogenic granuloma on the upper lip: an unusual location.

    PubMed

    Gonçales, Eduardo Sanches; Damante, José Humberto; Fischer Rubira, Cassia Maria; Taveira, Luís Antônio de Assis

    2010-01-01

    Pyogenic granuloma (PG) is a benign non-neoplastic mucocutaneous lesion. It is a reactional response to constant minor trauma and might be related to hormonal changes. In the mouth, PG is manifested as a sessile or pedunculated, resilient, erythematous, exophytic and painful papule or nodule with a smooth or lobulated surface that bleeds easily. PG preferentially affects the gingiva, but may also occur on the lips, tongue, oral mucosa and palate. The most common treatment is surgical excision. This paper describes a mucocutaneous PG on the upper lip, analyzing the clinical characteristics and discussing the features that distinguish this lesion from other similar oral mucosa lesions. The diagnosis of oral lesions is complex and leads the dentist to consider distinct lesions with different diagnostic methods. This case report with a 4 year-follow-up calls the attention to the uncommon mucocutaneous labial location of PG and to the fact that surgical excision is the safest method for diagnosis and treatment of PG of the lip, even when involving the mucosa and skin. PMID:21085814

  9. Hematogenous pyogenic vertebral osteomyelitis: diagnostic value of radionuclide bone imaging

    SciTech Connect

    Adatepe, M.H.; Powell, O.M.; Isaacs, G.H.; Nichols, K.; Cefola, R.

    1986-11-01

    Hematogenous pyogenic vertebral osteomyelitis (HPVO) continues to be a diagnostic problem for clinicians due to nonspecific presentation of the disease (1,2). We reviewed our experience of the last 10 years to determine the diagnostic usefulness of radionuclide bone studies in this disease. We found 15 patients whose primary diagnosis was HPVO. Of the 15 patients, 12 had (99mTc)MDP bone scans which were all positive. Five of the 12 patients had positive (/sup 67/Ga)citrate scans and one patient with chronic active HPVO had negative /sup 67/Ga and (/sup 111/In)WBC bone images. At the same time, three patients' spine x-rays and one patient's CT scan of the vertebra were normal. Additionally, in three patients spine x-rays were interpreted as consistent with degenerative joint disease that contributed to the delay of the diagnosis. We conclude that when HPVO is suspected an abnormal (99mTc)MDP bone image increases the probability of the disease, even if the x-rays and CT scans of the spine are normal. An abnormal /sup 67/Ga image following an abnormal 99mTc bone image increases the specificity of the diagnosis. Normal (99mTc)MDP and (/sup 67/Ga)citrate bone images of the vertebra virtually exclude the diagnosis of HPVO.

  10. Salivaricin D, a novel intrinsically trypsin-resistant lantibiotic from Streptococcus salivarius 5M6c isolated from a healthy infant.

    PubMed

    Birri, Dagim Jirata; Brede, Dag Anders; Nes, Ingolf F

    2012-01-01

    In this work, we purified and characterized a newly identified lantibiotic (salivaricin D) from Streptococcus salivarius 5M6c. Salivaricin D is a 34-amino-acid-residue peptide (3,467.55 Da); the locus of the gene encoding this peptide is a 16.5-kb DNA segment which contains genes encoding the precursor of two lantibiotics, two modification enzymes (dehydratase and cyclase), an ABC transporter, a serine-like protease, immunity proteins (lipoprotein and ABC transporters), a response regulator, and a sensor histidine kinase. The immunity gene (salI) was heterologously expressed in a sensitive indicator and provided significant protection against salivaricin D, confirming its immunity function. Salivaricin D is a naturally trypsin-resistant lantibiotic that is similar to nisin-like lantibiotics. It is a relatively broad-spectrum bacteriocin that inhibits members of many genera of Gram-positive bacteria, including the important human pathogens Streptococcus pyogenes and Streptococcus pneumoniae. Thus, Streptococcus salivarius 5M6c may be a potential biological agent for the control of oronasopharynx-colonizing streptococcal pathogens or may be used as a probiotic bacterium. PMID:22101034

  11. Salivaricin D, a Novel Intrinsically Trypsin-Resistant Lantibiotic from Streptococcus salivarius 5M6c Isolated from a Healthy Infant

    PubMed Central

    Birri, Dagim Jirata; Brede, Dag Anders

    2012-01-01

    In this work, we purified and characterized a newly identified lantibiotic (salivaricin D) from Streptococcus salivarius 5M6c. Salivaricin D is a 34-amino-acid-residue peptide (3,467.55 Da); the locus of the gene encoding this peptide is a 16.5-kb DNA segment which contains genes encoding the precursor of two lantibiotics, two modification enzymes (dehydratase and cyclase), an ABC transporter, a serine-like protease, immunity proteins (lipoprotein and ABC transporters), a response regulator, and a sensor histidine kinase. The immunity gene (salI) was heterologously expressed in a sensitive indicator and provided significant protection against salivaricin D, confirming its immunity function. Salivaricin D is a naturally trypsin-resistant lantibiotic that is similar to nisin-like lantibiotics. It is a relatively broad-spectrum bacteriocin that inhibits members of many genera of Gram-positive bacteria, including the important human pathogens Streptococcus pyogenes and Streptococcus pneumoniae. Thus, Streptococcus salivarius 5M6c may be a potential biological agent for the control of oronasopharynx-colonizing streptococcal pathogens or may be used as a probiotic bacterium. PMID:22101034

  12. Acute abdomen due to group A streptococcus bacteremia caused by an isolate with a mutation in the csrS gene.

    PubMed

    Kaneko, Masahiko; Maruta, Masaki; Shikata, Hisaharu; Hanayama, Masakazu; Ikebe, Tadayoshi

    2015-11-01

    Streptococcus pyogenes (group A streptococcus) is an aerobic gram-positive coccus that causes infections ranging from non-invasive pharyngitis to severely invasive necrotizing fasciitis. Mutations in csrS/csrR and rgg, negative regulator genes of group A streptococcus, are crucial factors in the pathogenesis of streptococcal toxic shock syndrome, which is a severe, invasive infection characterized by sudden onset of shock and multiorgan failure, resulting in a high mortality rate. Here we present a case of group A streptococcal bacteremia in a 28-year-old Japanese woman with no relevant previous medical history. The patient developed progressive abdominal symptoms that may have been due to spontaneous bacterial peritonitis, followed by a state of shock, which did not fulfill the proposed criteria for streptococcal toxic shock. The isolate was found to harbor a mutation in the negative regulator csrS gene, whereas the csrR and rgg genes were intact. It was noteworthy that this strain carrying a csrS mutation had caused group A streptococcal bacteremia characterized by acute abdomen as the presenting symptom in a young individual who had been previously healthy. This case indicates that group A streptococcus with csrS mutations has potential virulence factors that are associated with the onset of group A streptococcal bacteremia that does not meet the diagnostic criteria for streptococcal toxic shock syndrome. PMID:26231317

  13. Pyogenic granuloma in patients treated with selective BRAF inhibitors: another manifestation of paradoxical pathway activation.

    PubMed

    Henning, Benjamin; Stieger, Pascale; Kamarachev, Jivko; Dummer, Reinhard; Goldinger, Simone M

    2016-06-01

    Cutaneous toxicities under therapy with selective BRAF inhibitors such as vemurafenib or encorafenib (LGX818) are frequent, including plantar hyperkeratosis, squamous cell carcinoma, and second primary melanoma. Pyogenic granuloma is a benign, rapidly growing, eruptive hemangioma that often bleeds and ulcerates. Common causes are mechanical trauma and cast immobilization, as well as multiple drugs such as retinoids and antineoplastic agents. However, the development of pyogenic granuloma under treatment with encorafenib (LGX818) has not yet been reported. These three cases might be further examples for paradoxical activation of the mitogen-activated protein kinase pathway. We report three male patients with metastatic BRAFV600E-mutated melanoma who developed pyogenic granulomas 16, 10, and 12 weeks after treatment initiation with the selective BRAF inhibitors vemurafenib or encorafenib (LGX818). Except for one patient receiving retinoids, the clinical history for other frequent causes of pyogenic granuloma was negative. Pyogenic granulomas are not listed in the drugs investigator brochure but seem to be associated with selective BRAF inhibitors and might be a cutaneous phenomenon of paradoxical mitogen-activated protein kinase pathway activation. This correlation has to be confirmed by further observations. PMID:27116335

  14. 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.

  15. A Gray-purple Mass on the Floor of the Mouth: Gigantic Mucogingival Pyogenic Granuloma in a Teenage Patient

    PubMed Central

    Brunet-LLobet, Lluís; Miranda-Rius, Jaume; Lahor-Soler, Eduard; Mrina, Ombeni; Nadal, Alfons

    2014-01-01

    Pyogenic granuloma is defined as a benign neoplasm of vascular phenotype. This case describes the clinical and histopathological features of a gigantic mucogingival pyogenic granuloma, in a 14-year-old healthy black boy. This exophytic gray-purple mass, related to a toothpick injury, had more than twelve-month evolution on the anterior mandible involving lingual area besides to the floor of the mouth pressing the right salivary duct. Conservative excision was performed, followed by uncomplicated healing with no recurrence in two years. The histopathological examination reported a pyogenic granuloma (lobular capillary haemangioma). The authors provide a discussion of the presurgical differential diagnosis of the lesion. This case report presents an extremely uncommon location of a gigantic pyogenic granuloma, involving mucogingival complex and affecting the salivary outflow. This clinical manuscript may shed light on the controversies about possible mechanisms inducing oral pyogenic granuloma. PMID:24987485

  16. Pyogenic granuloma of labial mucosa: A misnomer in an anomolous site

    PubMed Central

    Ravi, Vaiyapuri; Jacob, Mathew; Sivakumar, Aandamuthu; Saravanan, Srinivasan; Priya, Kesavan

    2012-01-01

    Pyogenic granuloma is tumor-like proliferation to a nonspecific infection. Clinically, pyogenic granuloma presents as sessile or pedunculated exophytic mass with a smooth or lobulated surface which has a tendency to bleed easily. These lesions tend to occur slightly more in females, frequently involving the gingiva of the maxillary region. Histologically, these lesions show an excessive proliferation of vascular type of connective tissue to a nonspecific infection. The most common treatment is surgical excision with eradication of local irritants. This case report describes a pyogenic granuloma on the labial mucosa in a 33-year-old male, discussing the clinical features and histopathologic features that distinguish this lesion from other similar oral mucosa lesions. PMID:23066251

  17. Pyogenic Sacroiliitis and Pyomyositis in a Patient with Systemic Lupus Erythematous

    PubMed Central

    Chebbi, Wafa; Jerbi, Saida; Kessomtini, Wassia; Fradi, Asma; Sfar, Mohamed Habib

    2014-01-01

    Pyogenic sacroiliitis and pyomyositis are uncommon infectious diseases and their diagnoses are often delayed. They are typically seen in children and young adults and are rare in middle-aged people especially in those affected by rheumatic diseases. We present the first case of a Staphylococcus aureus related pyogenic sacroiliitis associated with iliacus and gluteal pyomyositis occurring in a patient with systemic lupus erythematosus. Antibiotic treatment was administered for a total of 6 weeks with a total recovery. Pyogenic sacroiliitis and pyomyositis, although remaining rare events, should be remembered as severe complications in immunosuppressed patients with inflammatory diseases. Early clinical suspicion, imaging diagnosis, and adequate therapy are decisive for the satisfactory outcome. PMID:25165609

  18. Pyogenic granuloma of the gingiva: A misnomer? – A case report and review of literature

    PubMed Central

    Gomes, Sheiba R.; Shakir, Quaid Johar; Thaker, Prarthana V.; Tavadia, Jamshed K.

    2013-01-01

    Pyogenic granuloma is a commonly occurring inflammatory hyperplasia of the skin and oral mucosa. It is not associated with pus as its name suggests and histologically it resembles an angiomatous lesion rather than a granulomatous lesion. It is known by a variety of names such as Crocker and Hartzell's disease, granuloma pyogenicum, granuloma pediculatum benignum, benign vascular tumor and during pregnancy as granuloma gravidarum. This tumor like growth is considered to be non-neoplastic in nature and it presents itself in the oral cavity in various clinical and histological forms. Due to its frequent occurrence in the oral cavity, especially the gingiva, this article presents a case report of a large pyogenic granuloma of the gingiva and its management, reviews the literature and discusses why the term “pyogenic granuloma” is a misnomer. PMID:24174735

  19. Streptococcus pneumoniae Serotype 3 among Costa Rican Children with Otitis Media: clinical, epidemiological characteristics and antimicrobial resistance patterns

    PubMed Central

    Abdelnour, Arturo; Soley, Carolina; Guevara, Silvia; Porat, Nurith; Dagan, Ron; Arguedas, Adriano

    2009-01-01

    Background After the introduction of the seven valent-pneumococcal conjugated vaccine into our National Immunization Program, it is important to establish and track local serotype distribution in order to evaluate its impact specially because serotype replacement phenomena has been described. To describe the clinical, epidemiological and antimicrobial resistance patterns of Costa Rican children with otitis media caused by Streptococcus pneumoniae serotype 3. Methods Middle ear fluid samples were obtained from Costa Rican children with otitis media who participated in various antimicrobial clinical trials between 1992 and 2007. Streptococcus pneumoniae was identified according to laboratory standard procedures. Strains were serotyped and antimicrobial susceptibility to penicillin, amoxicillin, cefuroxime, ceftriaxone, azithromycin and levofloxacin was determined by E-test. Results Throughout 1992–2007 a total of 1919 tympanocentesis were performed in children with otitis media (median age: 19 months) and yielded a total of 1208 middle ear isolates. The most common pathogens were: Streptococcus pneumoniae, 511 isolates (49%); Non-Typable Haemophilus influenzae, 386 isolates (37%); Moraxella catarrahalis, 100 isolates (9.5%); and Streptococcus pyogenes, 54 isolates (5%). Streptococcus pneumoniae serotyping was performed in 346/511 isolates (68%) recovered during years 1999–2006. The most common serotypes were 19F (101/30.0%), 14 (46/13.7%), 3 (34/10.1%), 6B (30/8.9%) and 23F (23/6.8%). Analysis performed per years showed a higher prevalence of serotype 3 Streptococcus pneumoniae during the study period 2004 and 2005. During the entire study period (1999–2006) serotype 3 was most commonly isolated in children older than 24 months (61.2% vs 40.6%;P = 0.05) and showed a lower rate of penicillin non-susceptibility (4.0% vs 18%; P = 0.003). Conclusion Streptococcus pneumoniae serotype 3 is an important pathogen in Costa Rican children with otitis media, especially in

  20. Zolpidem Use Associated With Increased Risk of Pyogenic Liver Abscess: A Case-Control Study in Taiwan.

    PubMed

    Liao, Kuan-Fu; Lin, Cheng-Li; Lai, Shih-Wei; Chen, Wen-Chi

    2015-08-01

    The purpose of this study was to explore the association between zolpidem use and pyogenic liver abscess in Taiwan.This was a population-based case-control study using the database of the Taiwan National Health Insurance Program since 2000 to 2011. We identified 1325 patients aged 20 to 84 years with the first-attack of pyogenic liver abscess as the cases, and 5082 patients without pyogenic liver abscess matched with sex, age, comorbidities, and index year of hospitalization for pyogenic liver abscess as the controls. Patients whose last remaining 1 tablet for zolpidem was noted ≤7 days before the date of admission for pyogenic liver abscess were defined as current use of zolpidem. Patients whose last remaining 1 tablet for zolpidem was noted >7 days before the date of admission for pyogenic liver abscess were defined as late use of zolpidem. Patients who never received 1 prescription for zolpidem were defined as never use of zolpidem. A multivariable unconditional logistic regression model was used to measure the odds ratio (OR) and 95% confidence interval (CI) to explore the association between zolpidem use and pyogenic liver abscess.After adjustment for possible confounding variables, the adjusted OR of pyogenic liver abscess was 3.89 for patients with current use of zolpidem (95% CI 2.89, 5.23), when compared with those with never use of zolpidem. The adjusted OR decreased to 0.85 for those with late use of zolpidem (95% CI 0.70, 1.03), but without statistical significance.Current use of zolpidem is associated with the increased risk of pyogenic liver abscess. Physicians should take the risk of pyogenic liver abscess into account when prescribing zolpidem. PMID:26266369

  1. NAD+-Glycohydrolase Promotes Intracellular Survival of Group A Streptococcus

    PubMed Central

    Sharma, Onkar; O’Seaghdha, Maghnus; Velarde, Jorge J.; Wessels, Michael R.

    2016-01-01

    A global increase in invasive infections due to group A Streptococcus (S. pyogenes or GAS) has been observed since the 1980s, associated with emergence of a clonal group of strains of the M1T1 serotype. Among other virulence attributes, the M1T1 clone secretes NAD+-glycohydrolase (NADase). When GAS binds to epithelial cells in vitro, NADase is translocated into the cytosol in a process mediated by streptolysin O (SLO), and expression of these two toxins is associated with enhanced GAS intracellular survival. Because SLO is required for NADase translocation, it has been difficult to distinguish pathogenic effects of NADase from those of SLO. To resolve the effects of the two proteins, we made use of anthrax toxin as an alternative means to deliver NADase to host cells, independently of SLO. We developed a novel method for purification of enzymatically active NADase fused to an amino-terminal fragment of anthrax toxin lethal factor (LFn-NADase) that exploits the avid, reversible binding of NADase to its endogenous inhibitor. LFn-NADase was translocated across a synthetic lipid bilayer in vitro in the presence of anthrax toxin protective antigen in a pH-dependent manner. Exposure of human oropharyngeal keratinocytes to LFn-NADase in the presence of protective antigen resulted in cytosolic delivery of NADase activity, inhibition of protein synthesis, and cell death, whereas a similar construct of an enzymatically inactive point mutant had no effect. Anthrax toxin-mediated delivery of NADase in an amount comparable to that observed during in vitro infection with live GAS rescued the defective intracellular survival of NADase-deficient GAS and increased the survival of SLO-deficient GAS. Confocal microscopy demonstrated that delivery of LFn-NADase prevented intracellular trafficking of NADase-deficient GAS to lysosomes. We conclude that NADase mediates cytotoxicity and promotes intracellular survival of GAS in host cells. PMID:26938870

  2. NAD+-Glycohydrolase Promotes Intracellular Survival of Group A Streptococcus.

    PubMed

    Sharma, Onkar; O'Seaghdha, Maghnus; Velarde, Jorge J; Wessels, Michael R

    2016-03-01

    A global increase in invasive infections due to group A Streptococcus (S. pyogenes or GAS) has been observed since the 1980s, associated with emergence of a clonal group of strains of the M1T1 serotype. Among other virulence attributes, the M1T1 clone secretes NAD+-glycohydrolase (NADase). When GAS binds to epithelial cells in vitro, NADase is translocated into the cytosol in a process mediated by streptolysin O (SLO), and expression of these two toxins is associated with enhanced GAS intracellular survival. Because SLO is required for NADase translocation, it has been difficult to distinguish pathogenic effects of NADase from those of SLO. To resolve the effects of the two proteins, we made use of anthrax toxin as an alternative means to deliver NADase to host cells, independently of SLO. We developed a novel method for purification of enzymatically active NADase fused to an amino-terminal fragment of anthrax toxin lethal factor (LFn-NADase) that exploits the avid, reversible binding of NADase to its endogenous inhibitor. LFn-NADase was translocated across a synthetic lipid bilayer in vitro in the presence of anthrax toxin protective antigen in a pH-dependent manner. Exposure of human oropharyngeal keratinocytes to LFn-NADase in the presence of protective antigen resulted in cytosolic delivery of NADase activity, inhibition of protein synthesis, and cell death, whereas a similar construct of an enzymatically inactive point mutant had no effect. Anthrax toxin-mediated delivery of NADase in an amount comparable to that observed during in vitro infection with live GAS rescued the defective intracellular survival of NADase-deficient GAS and increased the survival of SLO-deficient GAS. Confocal microscopy demonstrated that delivery of LFn-NADase prevented intracellular trafficking of NADase-deficient GAS to lysosomes. We conclude that NADase mediates cytotoxicity and promotes intracellular survival of GAS in host cells. PMID:26938870

  3. Illustration of a Common Framework for Relating Multiple Typing Methods by Application to Macrolide-Resistant Streptococcus pyogenes†

    PubMed Central

    Carriço, J. A.; Silva-Costa, C.; Melo-Cristino, J.; Pinto, F. R.; de Lencastre, H.; Almeida, J. S.; Ramirez, M.

    2006-01-01

    The studies that correlate the results obtained by different typing methodologies rely solely on qualitative comparisons of the groups defined by each methodology. We propose a framework of measures for the quantitative assessment of correspondences between different typing methods as a first step to the global mapping of type equivalences. A collection of 325 macrolide-resistant Streptococcus pyogenes isolates associated with pharyngitis cases in Portugal was used to benchmark the proposed measures. All isolates were characterized by macrolide resistance phenotyping, T serotyping, emm sequence typing, and pulsed-field gel electrophoresis (PFGE), using SmaI or Cfr9I and SfiI. A subset of 41 isolates, representing each PFGE cluster, was also characterized by multilocus sequence typing (MLST). The application of Adjusted Rand and Wallace indices allowed the evaluation of the strength and the directionality of the correspondences between the various typing methods and showed that if PFGE or MLST data are available one can confidently predict the emm type (Wallace coefficients of 0.952 for both methods). In contrast, emm typing was a poor predictor of PFGE cluster or MLST sequence type (Wallace coefficients of 0.803 and 0.655, respectively). This was confirmed by the analysis of the larger data set available from http://spyogenes.mlst.net and underscores the necessity of performing PFGE or MLST to unambiguously define clones in S. pyogenes. PMID:16825375

  4. Human TRAV1-2-negative MR1-restricted T cells detect S. pyogenes and alternatives to MAIT riboflavin-based antigens

    PubMed Central

    Meermeier, Erin W.; Laugel, Bruno F.; Sewell, Andrew K.; Corbett, Alexandra J.; Rossjohn, Jamie; McCluskey, James; Harriff, Melanie J.; Franks, Tamera; Gold, Marielle C.; Lewinsohn, David M.

    2016-01-01

    Mucosal-associated invariant T (MAIT) cells are thought to detect microbial antigens presented by the HLA-Ib molecule MR1 through the exclusive use of a TRAV1-2-containing TCRα. Here we use MR1 tetramer staining and ex vivo analysis with mycobacteria-infected MR1-deficient cells to demonstrate the presence of functional human MR1-restricted T cells that lack TRAV1-2. We characterize an MR1-restricted clone that expresses the TRAV12-2 TCRα, which lacks residues previously shown to be critical for MR1-antigen recognition. In contrast to TRAV1-2+ MAIT cells, this TRAV12-2-expressing clone displays a distinct pattern of microbial recognition by detecting infection with the riboflavin auxotroph Streptococcus pyogenes. As known MAIT antigens are derived from riboflavin metabolites, this suggests that TRAV12-2+ clone recognizes unique antigens. Thus, MR1-restricted T cells can discriminate between microbes in a TCR-dependent manner. We postulate that additional MR1-restricted T-cell subsets may play a unique role in defence against infection by broadening the recognition of microbial metabolites. PMID:27527800

  5. Human TRAV1-2-negative MR1-restricted T cells detect S. pyogenes and alternatives to MAIT riboflavin-based antigens.

    PubMed

    Meermeier, Erin W; Laugel, Bruno F; Sewell, Andrew K; Corbett, Alexandra J; Rossjohn, Jamie; McCluskey, James; Harriff, Melanie J; Franks, Tamera; Gold, Marielle C; Lewinsohn, David M

    2016-01-01

    Mucosal-associated invariant T (MAIT) cells are thought to detect microbial antigens presented by the HLA-Ib molecule MR1 through the exclusive use of a TRAV1-2-containing TCRα. Here we use MR1 tetramer staining and ex vivo analysis with mycobacteria-infected MR1-deficient cells to demonstrate the presence of functional human MR1-restricted T cells that lack TRAV1-2. We characterize an MR1-restricted clone that expresses the TRAV12-2 TCRα, which lacks residues previously shown to be critical for MR1-antigen recognition. In contrast to TRAV1-2(+) MAIT cells, this TRAV12-2-expressing clone displays a distinct pattern of microbial recognition by detecting infection with the riboflavin auxotroph Streptococcus pyogenes. As known MAIT antigens are derived from riboflavin metabolites, this suggests that TRAV12-2(+) clone recognizes unique antigens. Thus, MR1-restricted T cells can discriminate between microbes in a TCR-dependent manner. We postulate that additional MR1-restricted T-cell subsets may play a unique role in defence against infection by broadening the recognition of microbial metabolites. PMID:27527800

  6. 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. PMID:26555114

  7. Counteractive Balancing of Transcriptome Expression Involving CodY and CovRS in Streptococcus pyogenes▿†

    PubMed Central

    Kreth, Jens; Chen, Zhiyun; Ferretti, Joseph; Malke, Horst

    2011-01-01

    Streptococcus pyogenes (group A streptococcus [GAS]) responds to environmental changes in a manner that results in an adaptive regulation of the transcriptome. The objective of the present study was to understand how two global transcriptional regulators, CodY and CovRS, coordinate the transcriptional network in S. pyogenes. Results from expression microarray data and quantitative reverse transcription-PCR (qRT-PCR) showed that the global regulator CodY controls the expression of about 250 genes, or about 17% of the genome of strain NZ131. Additionally, the codY gene was shown to be negatively autoregulated, with its protein binding directly to the promoter region with a CodY binding site. In further studies, the influence of codY, covRS, and codY-covRS mutations on gene expression was analyzed in growth phase-dependent conditions using C medium, reported to mimic nutritional abundance and famine conditions similar to those found during host GAS infection. Additional biological experiments of several virulence phenotypes, including pilin production, biofilm formation, and NAD glycohydrolase activity, demonstrated the role that both CodY and CovRS play in their regulation. Correlation analysis of the overall data revealed that, in exponentially growing cells, CodY and CovRS act in opposite directions, with CodY stimulating and CovRS repressing a substantial fraction of the core genome, including many virulence factors. This is the first report of counteractive balancing of transcriptome expression by global transcription regulators and provides important insight into how GAS modulates gene expression by integrating important extracellular and intracellular information. PMID:21705595

  8. Pyogenic and non-pyogenic spinal infections: emphasis on diffusion-weighted imaging for the detection of abscesses and pus collections.

    PubMed

    Moritani, T; Kim, J; Capizzano, A A; Kirby, P; Kademian, J; Sato, Y

    2014-09-01

    The incidence of spinal infections has increased in the past two decades, owing to the increasing number of elderly patients, immunocompromised conditions, spinal surgery and instrumentation, vascular access and intravenous drug use. Conventional MRI is the gold standard for diagnostic imaging; however, there are still a significant number of misdiagnosed cases. Diffusion-weighted imaging (DWI) with a b-value of 1000 and apparent diffusion coefficient (ADC) maps provide early and accurate detection of abscess and pus collection. Pyogenic infections are classified into four types of extension based on MRI and DWI findings: (1) epidural/paraspinal abscess with spondylodiscitis, (2) epidural/paraspinal abscess with facet joint infection, (3) epidural/paraspinal abscess without concomitant spondylodiscitis or facet joint infection and (4) intradural abscess (subdural abscess, purulent meningitis and spinal cord abscess). DWI easily detects abscesses and demonstrates the extension, multiplicity and remote disseminated infection. DWI is often a key image in the differential diagnosis. Important differential diagnoses include epidural, subdural or subarachnoid haemorrhage, cerebrospinal fluid leak, disc herniation, synovial cyst, granulation tissue, intra- or extradural tumour and post-surgical fluid collections. DWI and the ADC values are affected by susceptibility artefacts, incomplete fat suppression and volume-averaging artefacts. Recognition of artefacts is essential when interpreting DWI of spinal and paraspinal infections. DWI is not only useful for the diagnosis but also for the treatment planning of pyogenic and non-pyogenic spinal infections. PMID:24999081

  9. Pyogenic and non-pyogenic spinal infections: emphasis on diffusion-weighted imaging for the detection of abscesses and pus collections

    PubMed Central

    Kim, J; Capizzano, A A; Kirby, P; Kademian, J; Sato, Y

    2014-01-01

    The incidence of spinal infections has increased in the past two decades, owing to the increasing number of elderly patients, immunocompromised conditions, spinal surgery and instrumentation, vascular access and intravenous drug use. Conventional MRI is the gold standard for diagnostic imaging; however, there are still a significant number of misdiagnosed cases. Diffusion-weighted imaging (DWI) with a b-value of 1000 and apparent diffusion coefficient (ADC) maps provide early and accurate detection of abscess and pus collection. Pyogenic infections are classified into four types of extension based on MRI and DWI findings: (1) epidural/paraspinal abscess with spondylodiscitis, (2) epidural/paraspinal abscess with facet joint infection, (3) epidural/paraspinal abscess without concomitant spondylodiscitis or facet joint infection and (4) intradural abscess (subdural abscess, purulent meningitis and spinal cord abscess). DWI easily detects abscesses and demonstrates the extension, multiplicity and remote disseminated infection. DWI is often a key image in the differential diagnosis. Important differential diagnoses include epidural, subdural or subarachnoid haemorrhage, cerebrospinal fluid leak, disc herniation, synovial cyst, granulation tissue, intra- or extradural tumour and post-surgical fluid collections. DWI and the ADC values are affected by susceptibility artefacts, incomplete fat suppression and volume-averaging artefacts. Recognition of artefacts is essential when interpreting DWI of spinal and paraspinal infections. DWI is not only useful for the diagnosis but also for the treatment planning of pyogenic and non-pyogenic spinal infections. PMID:24999081

  10. 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. PMID:25491120

  11. Complete Genome Sequence of Trueperella pyogenes, an Important Opportunistic Pathogen of Livestock.

    PubMed

    Machado, Vinicius S; Bicalho, Rodrigo C

    2014-01-01

    Here, we report the complete genome sequence of Trueperella pyogenes TP6375, a strain isolated from the uterus of a dairy cow affected with metritis. The complete circular genome is 2,338,390 bp and contains several genes needed for pathogenicity. PMID:24786956

  12. Pyogenic Liver Abscess Due to Rhodococcus equi in an Immunocompetent Host

    PubMed Central

    Napoleão, Fátima; Vieira Damasco, Paulo; Ferreira Camello, Thereza Cristina; Damasceno do Vale, Márcio; Braga de Andrade, Arnaldo Feitosa; Hirata, Raphael; de Mattos-Guaraldi, Ana Luíza

    2005-01-01

    A case of pyogenic liver abscess (PLA) due to Rhodococcus equi in an immunocompetent individual was successfully treated by combining surgery and antibiotics. The R. equi-targeted antimicrobial agents erythromycin and rifampin were used only after surgical resection of the lesion and identification of the infective organism. PMID:15695730

  13. Multiple Pyogenic Granulomas After Burns: Response to Conservative Treatment in Five Children.

    PubMed

    Zhao, Hongliang; Zhao, Huanjun; Zhang, Cuiping; Fu, Xiaobing

    2015-01-01

    We describe five children with multiple pyogenic granulomas after burns that were healed effectively using conservative treatment consisting of 1% povidone-iodine, silver nanoparticle dressing, and antibiotics. No relapse of the lesions was observed from 6 months to 2 years later. PMID:25895011

  14. Complete Genome Sequence of Trueperella pyogenes, an Important Opportunistic Pathogen of Livestock

    PubMed Central

    Machado, Vinicius S.

    2014-01-01

    Here, we report the complete genome sequence of Trueperella pyogenes TP6375, a strain isolated from the uterus of a dairy cow affected with metritis. The complete circular genome is 2,338,390 bp and contains several genes needed for pathogenicity. PMID:24786956

  15. Pyogenic cervical spondylitis with quadriplegia as a complication of severe burns: Report of a case.

    PubMed

    Asakage, Naoki; Katami, Atsuo; Takekawa, Satoru; Suzuki, Tetsuya; Goto, Michitoshi; Fukai, Ryuta

    2006-01-01

    We report a case of cervical pyogenic spondylitis complicated by epidural abscess with quadriplegia during treatment of severe burns. The patient was a 49-year-old man with 3rd-degree burns to 20% of his body, involving the lower extremities. We performed escharectomy of the 3rd-degree necrosis on days 7 and 16, followed by the first skin graft on day 23. Pseudomonas aeruginosa was detected in the postoperative graft wound culture. On day 23 after the skin graft, he became febrile and began to experience cervical pain and muscle weakness of the extremities. By day 24, quadriplegia had developed. A cervical vertebral magnetic resonance imaging (MRI) scan showed pyogenic spondylitis with an epidural abscess, which was causing the quadriplegia. We treated the patient by performing curettage of the pyogenic lesion and anterior fixation of the cervical vertebral bodies. The fact that P. aeruginosa was detected in the pyogenic focus culture indicated that burn wound sepsis was responsible for the infection. This case reinforces that acting on a strong suspicion helps to establish a diagnosis and initiate appropriate treatment early. PMID:17072727

  16. Point-of-Care Ultrasound in the Evaluation of Pyogenic Flexor Tenosynovitis.

    PubMed

    Cohen, Stephanie G; Beck, Sierra C

    2015-11-01

    A 4-year-old girl presented to the emergency department for evaluation of finger swelling after a dog bite. Point-of-care ultrasound was used to diagnose pyogenic flexor tenosynovitis of the digit after visualizing a fluid collection within the flexor tendon sheath. The patient underwent emergent incision and drainage of the digit with good outcome. PMID:26535504

  17. Anterior instrumentation for the treatment of pyogenic vertebral osteomyelitis of thoracic and lumbar spine

    PubMed Central

    Chen, Wei-Hua; Jiang, Lei-Sheng

    2008-01-01

    Anterior radical debridement and bone grafting is popular in the treatment of pyogenic infection of the spine, but there remains great concern of placing instrumentation in the presence of infection because of the potentiality of infection recurrence after surgery. The objective of this study was to prospectively evaluate the efficacy and safety of anterior instrumentation in patients who underwent simultaneous anterior debridement and autogenous bone grafting for the treatment of pyogenic vertebral osteomyelitis. The series consisted of 22 consecutive patients who were treated with anterior debridement, interbody fusion with autogenous bone grafting and anterior instrumentation for pyogenic vertebral osteomyelitis of thoracic and lumbar spine. The patients were prospectively followed up for a minimum of 3 years (average 46.1 months; range 36–74 months). Data were obtained for assessing clinically the neurological function and pain and radiologically the spinal alignment and fusion progress as well as recurrence of the infection. All the patients experienced complete or significant relief of back pain with rapid improvement of neurological function. Kyphosis was improved with an average correction rate of 93.1% (range 84–100%). Solid fusion and healing of the infection was achieved in all the patients without any evidence of recurrent or residual infection. The study shows that combined with perioperative antibiotic regimen, anterior instrumentation is effective and safe in the treatment of pyogenic vertebral osteomyelitis of thoracic and lumbar spine directly following radical debridement and autogenous bone grafting. PMID:18575900

  18. 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

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

    PubMed

    Patras, K