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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

    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. 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

  4. 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.

  5. Gene repertoire evolution of Streptococcus pyogenes inferred from phylogenomic analysis with Streptococcus canis and Streptococcus dysgalactiae.

    PubMed

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

    2012-01-01

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

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

    PubMed Central

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

    2012-01-01

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

  7. 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.

  8. 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

  9. 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.

  10. Detection of Streptococcus pyogenes using rapid visual molecular assay.

    PubMed

    Zhao, Xiangna; He, Xiaoming; Li, Huan; Zhao, Jiangtao; Huang, Simo; Liu, Wei; Wei, Xiao; Ding, Yiwei; Wang, Zhaoyan; Zou, Dayang; Wang, Xuesong; Dong, Derong; Yang, Zhan; Yan, Xiabei; Huang, Liuyu; Du, Shuangkui; Yuan, Jing

    2015-09-01

    Streptococcus pyogenes is an increasingly important pathogen in many parts of the world. Rapid and accurate detection of S. pyogenes aids in the control of the infection. In this study, a loop-mediated isothermal amplification (LAMP) assay was developed and validated for the specific detection of S. pyogenes. The assay incorporates two methods: a chromogenic analysis using a calcein/Mn(2+) complex and real-time turbidity monitoring to assess the reaction. Both methods detected the target DNA within 60 min under 64°C isothermal conditions. The assay used specifically designed primers to target spy1258, and correctly identified 111 strains of S. pyogenes and 32 non-S. pyogenes strains, including other species of the genus Streptococcus. Tests using reference strains showed that the LAMP assay was highly specific. The sensitivity of the assay, with a detection limit of 1.49 pg DNA, was 10-fold greater than that of PCR. The LAMP assay established in this study is simple, fast and sensitive, and does not rely upon any special equipment; thus, it could be employed in clinical diagnosis.

  11. The role of coagulation/fibrinolysis during Streptococcus pyogenes infection.

    PubMed

    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.

  12. Macrolide-resistant Streptococcus pyogenes: prevalence and treatment strategies.

    PubMed

    Silva-Costa, Catarina; Friães, Ana; Ramirez, Mario; Melo-Cristino, Jose

    2015-05-01

    Although penicillin remains the first-choice treatment for Streptococcus pyogenes infection, macrolides are important alternatives for allergic patients and lincosamides are recommended together with β-lactams in invasive infections. S. pyogenes may exhibit macrolide resistance because of active efflux (mef genes) or target modification (erm genes), the latter conferring cross resistance to lincosamides and streptogramin B. Worldwide, resistance is restricted to a limited number of genetic lineages, despite resistance genes being encoded on mobile genetic elements. For reasons that are not completely clear, resistance and the associated phenotypes are highly variable across countries. Although resistance remains high in several countries, particularly in Asia, an overall decreasing trend of resistance has been noted in recent years, mostly in Europe. This decrease is not always accompanied by declines in macrolide consumption, suggesting significant roles of other factors in determining the dynamics of macrolide-resistant clones. Continued surveillance is needed to obtain further insights into the forces governing macrolide resistance in S. pyogenes.

  13. 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

  14. Periprosthetic breast abscess caused by Streptococcus pyogenes after scarlet fever.

    PubMed

    Persichetti, Paolo; Langella, Marika; Marangi, Giovanni Francesco; Vulcano, Ettore; Gherardi, Giovanni; Dicuonzo, Giordano

    2008-01-01

    We present a case of a 32-year-old white women, affected by breast cancer and treated with mastectomy, who underwent immediate breast reconstruction with a tissue expander. She presented a periprosthetic infection from Streptococcus pyogenes (group A streptococcus, GAS) after scarlet fever. S. pyogenes may be responsible for suppurative complications of the respiratory system and a variety of metastatic foci of infection such as suppurative arthritic, endocarditis, meningitis, or brain abscess. Even though, in the literature, several cases and types of infection associated with breast implantation have been described, to our knowledge this is the first case report of periprosthetic infection after scarlet fever. Signs, symptoms, diagnosis, and treatment of GAS infection that occurred 2 months after the surgery are discussed.

  15. Laboratory growth and maintenance of Streptococcus pyogenes (the Group A Streptococcus, GAS).

    PubMed

    Gera, Kanika; McIver, Kevin S

    2013-10-02

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

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

    PubMed Central

    Gera, Kanika; McIver, Kevin S.

    2013-01-01

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

  17. Invasive Streptococcus pyogenes after allograft implantation--Colorado, 2003.

    PubMed

    2003-12-01

    Allograft tissues are used for various orthopedic procedures (e.g., ligament reconstruction, meniscal transplantation, and spinal surgery). In 2002, approximately one million allografts were distributed for transplantation (American Association of Tissue Banks [AATB], unpublished data, 2002). Recent reports of allograft-associated infections have prompted evaluation of the processing and quality-control methods employed by tissue processors. This report describes a case of invasive disease with Streptococcus pyogenes (i.e., group A streptococcus [GAS]), after reconstructive knee surgery using contaminated allograft tissue and provides recommendations to reduce the risk for allograft-associated infections. Although allograft infections are rare, they highlight the need for improved tissue evaluation and processing standards.

  18. Factors that cause trimethoprim resistance in Streptococcus pyogenes.

    PubMed

    Bergmann, René; van der Linden, Mark; Chhatwal, Gursharan S; Nitsche-Schmitz, D Patric

    2014-01-01

    The use of trimethoprim in treatment of Streptococcus pyogenes infections has long been discouraged because it has been widely believed that this pathogen is resistant to this antibiotic. To gain more insight into the extent and molecular basis of trimethoprim resistance in S. pyogenes, we tested isolates from India and Germany and sought the factors that conferred the resistance. Resistant isolates were identified in tests for trimethoprim or trimethoprim-sulfamethoxazole (SXT) susceptibility. Resistant isolates were screened for the known horizontally transferable trimethoprim-insensitive dihydrofolate reductase (dfr) genes dfrG, dfrF, dfrA, dfrD, and dfrK. The nucleotide sequence of the intrinsic dfr gene was determined for resistant isolates lacking the horizontally transferable genes. Based on tentative criteria, 69 out of 268 isolates (25.7%) from India were resistant to trimethoprim. Occurring in 42 of the 69 resistant isolates (60.9%), dfrF appeared more frequently than dfrG (23 isolates; 33.3%) in India. The dfrF gene was also present in a collection of SXT-resistant isolates from Germany, in which it was the only detected trimethoprim resistance factor. The dfrF gene caused resistance in 4 out of 5 trimethoprim-resistant isolates from the German collection. An amino acid substitution in the intrinsic dihydrofolate reductase known from trimethoprim-resistant Streptococcus pneumoniae conferred resistance to S. pyogenes isolates of emm type 102.2, which lacked other aforementioned dfr genes. Trimethoprim may be more useful in treatment of S. pyogenes infections than previously thought. However, the factors described herein may lead to the rapid development and spread of resistance of S. pyogenes to this antibiotic agent.

  19. Factors that cause trimethoprim resistance in Streptococcus pyogenes.

    PubMed

    Bergmann, René; van der Linden, Mark; Chhatwal, Gursharan S; Nitsche-Schmitz, D Patric

    2014-01-01

    The use of trimethoprim in treatment of Streptococcus pyogenes infections has long been discouraged because it has been widely believed that this pathogen is resistant to this antibiotic. To gain more insight into the extent and molecular basis of trimethoprim resistance in S. pyogenes, we tested isolates from India and Germany and sought the factors that conferred the resistance. Resistant isolates were identified in tests for trimethoprim or trimethoprim-sulfamethoxazole (SXT) susceptibility. Resistant isolates were screened for the known horizontally transferable trimethoprim-insensitive dihydrofolate reductase (dfr) genes dfrG, dfrF, dfrA, dfrD, and dfrK. The nucleotide sequence of the intrinsic dfr gene was determined for resistant isolates lacking the horizontally transferable genes. Based on tentative criteria, 69 out of 268 isolates (25.7%) from India were resistant to trimethoprim. Occurring in 42 of the 69 resistant isolates (60.9%), dfrF appeared more frequently than dfrG (23 isolates; 33.3%) in India. The dfrF gene was also present in a collection of SXT-resistant isolates from Germany, in which it was the only detected trimethoprim resistance factor. The dfrF gene caused resistance in 4 out of 5 trimethoprim-resistant isolates from the German collection. An amino acid substitution in the intrinsic dihydrofolate reductase known from trimethoprim-resistant Streptococcus pneumoniae conferred resistance to S. pyogenes isolates of emm type 102.2, which lacked other aforementioned dfr genes. Trimethoprim may be more useful in treatment of S. pyogenes infections than previously thought. However, the factors described herein may lead to the rapid development and spread of resistance of S. pyogenes to this antibiotic agent. PMID:24492367

  20. Human plasma fibronectin inhibits adherence of Streptococcus pyogenes to hexadecane.

    PubMed Central

    Courtney, H S; Ofek, I; Simpson, W A; Whitnack, E; Beachey, E H

    1985-01-01

    The effect of human plasma fibronectin on the adherence of Streptococcus pyogenes to hexadecane droplets was investigated. Fibronectin blocked the adherence of streptococci to hexadecane in a dose-dependent manner. The inhibitory effect resulted from the binding of fibronectin to the streptococcal cells; radiolabeled fibronectin failed to bind to the hexadecane but bound readily to untreated streptococci. Chemical treatments of streptococci that decreased streptococcal binding of fibronectin also decreased their binding to hexadecane. Pretreatment of fibronectin with lipoteichoic acid blocked the binding of fibronectin to streptococci and abolished its ability to inhibit streptococcal adherence to hexadecane in a dose-related manner. In contrast, wheat germ agglutinin, which binds to N-acetylglucosamine on the surface of S. pyogenes cells, failed to alter hexadecane adherence. The data suggest that fibronectin binds to lipoteichoic acid on the surface of the streptococci, thereby preventing lipoteichoic acid from interacting with the hexadecane phase. PMID:3880729

  1. Reliable five-minute test strip method for identification of Streptococcus pyogenes.

    PubMed

    Dealler, S F; Campbell, L; Kerr, K G; McGoldrick, J; Flannigan, K A; Hawkey, P M

    1989-04-01

    A novel and rapid method (Strep Strip, Lab M) for identification of Streptococcus pyogenes was evaluated. The method combines the established test for pyroglutamyl aminopeptidase (PYR) with a rapid chromogenic test for beta-glucosidase on a paper strip. The test was evaluated with 274 clinical isolates and 237 culture collection isolates of beta-haemolytic streptococci. Streptococcus pyogenes was identified with 100% specificity. Six isolates identified as Lancefield group A and which might therefore be assumed to be Streptococcus pyogenes were shown by the test strip method not to be this species. The beta-glucosidase test on the test strip allowed differentiation between enterococci and Streptococcus pyogenes (both PYR positive) in all cases. The test strip method represents an economical and accurate method for identification of Streptococcus pyogenes in clinical material. PMID:2565813

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

    PubMed

    Fischetti, Vincent A; Dale, James B

    2016-05-17

    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.

  3. 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

  4. Invasive Streptococcus pyogenes after allograft implantation--Colorado, 2003.

    PubMed

    2003-12-01

    Allograft tissues are used for various orthopedic procedures (e.g., ligament reconstruction, meniscal transplantation, and spinal surgery). In 2002, approximately one million allografts were distributed for transplantation (American Association of Tissue Banks [AATB], unpublished data, 2002). Recent reports of allograft-associated infections have prompted evaluation of the processing and quality-control methods employed by tissue processors. This report describes a case of invasive disease with Streptococcus pyogenes (i.e., group A streptococcus [GAS]), after reconstructive knee surgery using contaminated allograft tissue and provides recommendations to reduce the risk for allograft-associated infections. Although allograft infections are rare, they highlight the need for improved tissue evaluation and processing standards. PMID:14654764

  5. Distribution of small native plasmids in Streptococcus pyogenes in India.

    PubMed

    Bergmann, René; Nerlich, Andreas; Chhatwal, Gursharan S; Nitsche-Schmitz, D Patric

    2014-05-01

    Complete characterization of a Streptococcus pyogenes population from a defined geographic region comprises information on the plasmids that circulate in these bacteria. Therefore, we determined the distribution of small plasmids (<5kb) in a collection of 279 S. pyogenes isolates from India, where diversity of strains and incidence rates of S. pyogenes infections are high. The collection comprised 77 emm-types. For plasmid detection and discrimination, we developed PCRs for different plasmid replication initiation protein genes, the putative repressor gene copG and bacteriocin genes dysA and scnM57. Plasmid distribution was limited to 13 emm-types. Co-detection analysis using aforementioned PCRs revealed four distinct plasmid sub-types, two of which were previously unknown. Representative plasmids pA852 and pA996 of the two uncharacterized plasmid sub-types were sequenced. These two plasmids could be assigned to the pMV158 and the pC194/pUB110 family of rolling-circle plasmids, respectively. The majority of small plasmids found in India belonged to the two newly characterized sub-types, with pA852- and pA996-like plasmids amounting to 42% and 22% of all detected plasmids, respectively. None of the detected plasmids coded for a known antibiotic resistance gene. Instead, all of the four plasmid sub-types carried known or potential bacteriocin genes. These genes may have influence on the evolutionary success of certain S. pyogenes genotypes. Notably, pA852-like plasmids were found in all isolates of the most prevalent emm-type 11.0. Together, a priori fitness of this genotype and increased fitness due to the acquired plasmids may have rendered type emm11.0 successful and caused the prevalence of pA852-like plasmids in India.

  6. Probable role of Streptococcus pyogenes in Kawasaki disease.

    PubMed

    Akiyama, T; Yashiro, K

    1993-02-01

    Over the past 25 years, the clinical course of Kawasaki disease has been defined, the prevalence and nature of the cardiovascular effects widely understood, and pathological changes in the most severe cases well described. However, the aetiology and pathogenesis of this puzzling disease have remained unclear, thus specific therapy is not yet available. Because of some close clinical similarities between this disease and streptococcal scarlet fever, particular attention has been paid to the possible role of Streptococcus pyogenes as an aetiological agent in this illness. Until now, however, group A beta-haemolytic streptococci have never been consistently isolated from any patients; in addition, the titre of anti-streptolysin 0 is not raised, and lack of response to antibiotics is a feature of this disease. Our long series of investigations over more than 10 years, which will be covered in the present review, were performed in an attempt at elucidating causative agent(s) of Kawasaki disease. This has led to our firm belief in the probable role of S. pyogenes in the pathogenesis of this disease, despite the lack of fulfillment of Koch's postulates, on the basis of the following findings. Patients with Kawasaki disease recovering from the acute, febrile phase of the illness exhibited an exaggerated cell-mediated reactivity, as measured by the macrophage migration inhibition test, to group A beta-haemolytic streptococci, their pyrogenic exotoxin and streptolysin 0 as well as to several mammalian muscle cell extracts which are allegedly related antigenically to the cell wall and/or cytoplasmic membrane of S. pyogenes. Protoplast-like "spherical bodies" varying in diameter from 0.5 to 1.5 microns, and devoid of cell walls, were detected in the buffy coats of peripheral blood from patients with this disease, and stained distinctly by immuno-electron microscopy using, as a primary antibody, a rabbit antiserum to S. pyogenes- derived protoplasts, and followed by absorption

  7. 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

  8. [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.

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

    PubMed Central

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

    2014-01-01

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

  10. 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

  11. [Streptococcus pyogenes--much more than the aetiological agent of scarlet fever].

    PubMed

    Stock, Ingo

    2009-11-01

    The grampositive bacterium S. pyogenes (beta-haemolytic group A Streptococcus) is a natural colonizer of the human oropharynx mucous membrane and one of the most common agents of infectious diseases in humans. S. pyogenes causes the widest range of disease in humans among all bacterial pathogens. It is responsible for various skin infections such as impetigo contagiosa and erysipelas, and localized mucous membrane infections of the oropharynx (e. g. tonsillitis and pharyngitis). Betahaemolytic group A Streptococcus causes also invasive diseases such as sepses including puerperal sepsis. Additionally, S. pyogenes induces toxin-mediated syndromes, i. e. scarlet fever, streptococcal toxic shock syndrome (STSS) and necrotizing fasciitis (NF). STSS and NF are severe, frequently fatal diseases that have emerged in Europe and Northern America during the last two decades. Finally, some immunpathological diseases such as acute rheumatic fever and glomerulonephritis also result from S. pyogenes infections. Most scientists recommend penicillins (benzylpenicillin, phenoxymethylpenicllin) as drugs of first choice for treatment of Streptococcus tonsillopharyngitis and scarlet fever. Erysipelas and some other skin infections should be treated with benzylpenicillin. Intensive care measurements are needed for treatment of severe toxin-mediated S. pyogenes diseases. These measurements include the elimination of internal bacterial foci, concomitant application of clindamycin and benzylpenicillin and suitable treatment of shock symptoms. Management of immunpathological diseases requires antiphlogistical therapy. Because of the wide distribution of S. pyogenes in the general population and the lack of an effective vaccine, possibilities for prevention allowing a suitable protection for diseases due to S. pyogenes are very limited.

  12. 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

  13. 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

  14. 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

  15. 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.

  16. 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

  17. Biofilm formation enhances fomite survival of Streptococcus pneumoniae and Streptococcus pyogenes.

    PubMed

    Marks, Laura R; Reddinger, Ryan M; Hakansson, Anders P

    2014-03-01

    Both Streptococcus pyogenes and Streptococcus pneumoniae are widely thought to rapidly die outside the human host, losing infectivity following desiccation in the environment. However, to date, all literature investigating the infectivity of desiccated streptococci has used broth-grown, planktonic populations. In this study, we examined the impact of biofilm formation on environmental survival of clinical and laboratory isolates of S. pyogenes and S. pneumoniae as both organisms are thought to colonize the human host as biofilms. Results clearly demonstrate that while planktonic cells that are desiccated rapidly lose viability both on hands and abiotic surfaces, such as plastic, biofilm bacteria remain viable over extended periods of time outside the host and remain infectious in a murine colonization model. To explore the level and extent of streptococcal fomite contamination that children might be exposed to naturally, direct bacteriologic cultures of items in a day care center were conducted, which demonstrated high levels of viable streptococci of both species. These findings raise the possibility that streptococci may survive in the environment and be transferred from person to person via fomites contaminated with oropharyngeal secretions containing biofilm streptococci.

  18. Influenza A virus-infected hosts boost an invasive type of Streptococcus pyogenes infection in mice.

    PubMed

    Okamoto, Shigefumi; Kawabata, Shigetada; Nakagawa, Ichiro; Okuno, Yoshinobu; Goto, Toshiyuki; Sano, Kouichi; Hamada, Shigeyuki

    2003-04-01

    The apparent worldwide resurgence of invasive Streptococcus pyogenes infection in the last two decades remains unexplained. At present, animal models in which toxic shock-like syndrome or necrotizing fasciitis is induced after S. pyogenes infection are not well developed. We demonstrate here that infection with a nonlethal dose of influenza A virus 2 days before intranasal infection with a nonlethal dose of S. pyogenes strains led to a death rate of more than 90% in mice, 10% of which showed necrotizing fasciitis. Infection of lung alveolar epithelial cells by the influenza A virus resulted in viral hemagglutinin expression on the cell surface and promoted internalization of S. pyogenes. However, treatment with monoclonal antibodies to hemagglutinin markedly decreased this internalization. Our results indicate that prior infection with influenza A virus induces a lethal synergism, resulting in the induction of invasive S. pyogenes infection in mice.

  19. Nasopharyngeal Infection of Mice with Streptococcus pyogenes and In Vivo Detection of Superantigen Activity.

    PubMed

    Zeppa, Joseph J; Wakabayashi, Adrienne T; Kasper, Katherine J; Xu, Stacey X; Haeryfar, S M Mansour; McCormick, John K

    2016-01-01

    Streptococcus pyogenes is a globally prominent human-specific pathogen that is responsible for an enormous burden of infectious disease. Despite intensive experimental efforts to understand the molecular correlates that contribute to invasive infections, there has been less focus on S. pyogenes carriage and local infection of the nasopharynx. This chapter describes an acute nasopharyngeal infection model in mice that is utilized in our laboratory to study the role of superantigen toxins in the biology of S. pyogenes. We also describe a method to detect superantigen-specific T cell activation in vivo.

  20. Bacterial Pneumonia Caused by Streptococcus pyogenes Infection: A Case Report and Review of the Literature

    PubMed Central

    Akuzawa, Nobuhiro; Kurabayashi, Masahiko

    2016-01-01

    A 78-year-old Japanese man was admitted to our hospital because of fever lasting for 4 days. His white blood cell count and C-reactive protein level were elevated and computed tomography of the chest showed bronchopneumonia in the right upper lobe of the lung. Streptococcus pyogenes was detected from sputum and blood culture samples on admission and administration of ampicillin/sulbactam was effective. Although our patient’s clinical course was good, S. pyogenes pneumonia commonly shows a high rate of fatality and septicemia, and may affect a previously healthy population. Physicians should be aware of pernicious characteristics of S. pyogenes pneumonia. PMID:27738486

  1. Mechanism and regulation of phosphate transport in Streptococcus pyogenes

    SciTech Connect

    Reizer, J.; Saier, M.H. Jr.

    1987-01-01

    In contrast to results reported with other bacteria, uptake of /sup 32/Pi in Streptococcus pyogenes was found to occur rapidly in starved cultures and to be strongly and immediately inhibited by addition of exogenous glycolytic energy sources (such as glucose) and nonglycolytic sources of ATP (such as arginine). Preincubation of starved cells with NaF, iodoacetate, or arsenate eliminated the inhibiting effect of glucose but not that of arginine. In accordance with the hypothesis that transport was attributable to P/sub i/-P/sub i/ exchange, uptake and efflux of /sup 32/P/sub i/ in the presence of trans unlabeled P/sub i/ exhibited similar characteristics and were largely eliminated by reduction of the trans P/sub i/ concentration. Neither process was inhibited appreciably by pretreatment of cells with ionophores or metabolic inhibitors, but both processes were abolished by exposure to p-chloromercuribenzoate. Inhibition by both exogenous energy sources resulted in a reduction in the maximal velocity of transport (V/sub max/). Whereas arginine also caused a shift in the apparent Michaelis-Menten constant (K/sub m/) to larger values, glucose did not alter the K/sub m/. On the basis of the results reported, it is proposed that the rate of P/sub i/ exchange is determined positively by the intracellular and extracellular concentrations of P/sub i/ and negatively by ATP or metabolites thereof. The mechanism of ATP action is unknown but could involve either covalent or noncovalent modification of the carrier protein.

  2. Impact of immunization against SpyCEP during invasive disease with two streptococcal species: Streptococcus pyogenes and Streptococcus equi

    PubMed Central

    Turner, Claire E.; Kurupati, Prathiba; Wiles, Siouxsie; Edwards, Robert J.; Sriskandan, Shiranee

    2009-01-01

    Currently there is no licensed vaccine against the human pathogen Streptococcus pyogenes. The highly conserved IL-8 cleaving S. pyogenes cell envelope proteinase SpyCEP is surface expressed and is a potential vaccine candidate. A recombinant N-terminal part of SpyCEP (CEP) was expressed and purified. AntiCEP antibodies were found to neutralize the IL-8 cleaving activity of SpyCEP. CEP-immunized mice had reduced bacterial dissemination from focal S. pyogenes intramuscular infection and intranasal infection. We also identified a functional SpyCEP-homolog protease SeCEP, expressed by the equine pathogen Streptococcus equi, which was able to cleave both human and equine IL-8. CEP-immunized mice also demonstrated reduced bacterial dissemination from S. equi intramuscular infection. Therefore immunization against SpyCEP may provide protection against other streptococci species with homologous proteases. PMID:19563892

  3. Complete Genome Sequences of emm6 Streptococcus pyogenes JRS4 and Parental Strain D471

    PubMed Central

    Port, Gary C.; Paluscio, Elyse

    2015-01-01

    We report the complete genome assemblies of the group A Streptococcus pyogenes serotype emm6 strain D471 and its streptomycin-resistant derivative JRS4. Both of these well-studied laboratory strains have been extensively characterized over the past three decades and have been instrumental in the discovery of multiple aspects of streptococcal pathogenesis. PMID:26139722

  4. Complete Genome Sequence of Streptococcus pyogenes Strain JMUB1235 Isolated from an Acute Phlegmonous Gastritis Patient

    PubMed Central

    Watanabe, Shinya; Sasahara, Teppei; Arai, Naoshi; Sasaki, Kazumasa; Aiba, Yoshifumi; Sato’o, Yusuke

    2016-01-01

    Acute phlegmonous gastritis is an uncommon endogenous bacterial gastritis presenting with a high mortality rate. Here, we report the complete genome sequence of an emm89 Streptococcus pyogenes strain, JMUB1235, which is the causative agent of acute phlegmonous gastritis. PMID:27795272

  5. Analysis of the coverage capacity of the StreptInCor candidate vaccine against Streptococcus pyogenes.

    PubMed

    De Amicis, Karine M; Freschi de Barros, Samar; Alencar, Raquel E; Postól, Edilberto; Martins, Carlo de Oliveira; Arcuri, Helen Andrade; Goulart, Cibelly; Kalil, Jorge; Guilherme, Luiza

    2014-07-01

    Streptococcus pyogenes is responsible for infections as pharyngitis, sepsis, necrotizing fasciitis and streptococcal toxic shock syndrome. The M protein is the major bacterial antigen and consists of both polymorphic N-terminal portion and a conserved region. In the present study, we analyzed the in vitro ability of StreptInCor a C-terminal candidate vaccine against S. pyogenes to induce antibodies to neutralize/opsonize the most common S. pyogenes strains in Sao Paulo by examining the recognition by sera from StreptInCor immunized mice. We also evaluated the presence of cross-reactive antibodies against human heart valve tissue. Anti-StreptInCor antibodies were able to neutralize/opsonize at least 5 strains, showing that immunization with StreptInCor is effective against several S. pyogenes strains and can prevent infection and subsequent sequelae without causing autoimmune reactions.

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

    PubMed

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

    2015-07-01

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

  7. Comparative analysis of the localization of lipoteichoic acid in Streptococcus agalactiae and Streptococcus pyogenes.

    PubMed Central

    Mattingly, S J; Johnston, B P

    1987-01-01

    The cellular locations of deacylated lipoteichoic acid (dLTA) and lipoteichoic acid (LTA) were examined in late-exponential-phase cells of a serotype III strain of Streptococcus agalactiae (group B streptococci [GBS]) isolated from an infant with late-onset meningitis and compared with a fresh clinical isolate of Streptococcus pyogenes (group A streptococci [GAS]). LTA and dLTA were found to be associated with the protoplast membranes of both organisms, with only dLTA found in mutanolysin cell wall digests. Both organisms released dLTA during growth, but only the GAS released substantial levels of LTA into the culture medium. However, penicillin treatment (5 micrograms/ml for 60 min) of GBS resulted in the recovery of LTA in cell wall digests as well as in the culture medium. These results suggest that under normal growth conditions, the hydrophobic region (glycolipid) of LTA remains associated with the cytoplasmic membrane of GBS and unavailable for hydrophobic interactions at the cell surface with epithelial cells. In contrast, release of LTA into the environment by the GAS allows the fatty acid moieties to interact with hydrophobic domains on the surface of epithelial cells. These results may help explain the marked differences in the specificity of binding between these two major streptococcal pathogens for human fetal and adult epithelial cells. PMID:3308704

  8. High prevalence of fluoroquinolone-nonsusceptible Streptococcus pyogenes emm12 in Taiwan.

    PubMed

    Lin, Jiun-Nong; Chang, Lin-Li; Lai, Chung-Hsu; Huang, Yi-Han; Chen, Wei-Fang; Yang, Chih-Hui; Hsu, Janine; Lin, Hsi-Hsun; Chen, Yen-Hsu

    2015-10-01

    Fluoroquinolone-nonsusceptible Streptococcus pyogenes has rapidly emerged in several countries. The aim of this study was to survey the epidemiology and molecular characteristics of fluoroquinolone-nonsusceptible S. pyogenes in Taiwan. A total of 350 consecutive S. pyogenes isolates were collected between January 2005 and December 2012, including 152 (43.4%) invasive and 198 (56.6%) noninvasive isolates. Thirty-nine isolates (11.1%) of S. pyogenes were nonsusceptible to fluoroquinolones, including one emm1/ST28, 4 emm4/ST39, 33 emm12/ST36, and 1 emm87/ST62. Of all the isolates, emm12 (50%) demonstrated the highest prevalence of fluoroquinolone nonsusceptibility. Alterations of Ser79Phe and Ala12Val in ParC were the most frequently mutations in fluoroquinolone-nonsusceptible S. pyogenes isolates. There were no amino acid substitutions in GyrB, and 1 emm87 isolate exhibited 3 nonsynonymous mutations in ParE. Our study reveals the emergence of fluoroquinolone-nonsusceptible S. pyogenes emm12/ST36 in Taiwan. Regular surveillance of fluoroquinolone susceptibility in S. pyogenes is suggested.

  9. Severe acute otitis media caused by mucoid Streptococcus pyogenes in a previously healthy adult.

    PubMed

    Kakuta, Risako; Yano, Hisakazu; Hidaka, Hiroshi; Miyazaki, Hiromitsu; Irimada, Mihoko; Oda, Kiyoshi; Arai, Kazuaki; Ozawa, Daiki; Takahashi, Takashi; Kaku, Mitsuo; Katori, Yukio

    2014-01-01

    Streptococcus (S.) pyogenes is well recognized as the most common pathogen causing pharyngotonsillitis in school-age children. In Japan, mucoid Streptococcus pneumoniae is well known as a causative agent of severe acute otitis media (AOM); however, mucoid S. pyogenes has rarely been reported. To the best of our knowledge, this is the first report of an AOM patient caused by mucoid S. pyogenes in Japan. A 36-year-old previously healthy female was referred to our hospital with suspicion of cerebrospinal otorrhea due to increasing otalgia accompanied by headache following myringotomy. Bacterial cultures of middle ear secretions were performed, and mucoid-form colonies surrounded by zones of complete β-hemolysis were produced on sheep's blood agar. Antigen-agglutination test results were positive for S. pyogenes, and thus the patient received treatment with panipenem-betamipron 2.0 g/day for 10 days, which resolved nearly all symptoms. The bacteriological features of this strain were then investigated. The M-protein genotype encoded by the emm gene, the major virulence factor of S. pyogenes, was determined to be emm75. Generally, S. pyogenes forms colonies having non-mucoid matt appearances based on β-hemolysis of sheep's blood agar. The mucoid phenotype results from abundant production of hyaluronic acid capsular polysaccharide, a key virulence determinant. emm75 is common in noninvasive, but less common in invasive disease. In conclusion, mucoid S. pyogenes can cause severe infection even in previously healthy persons. Emergence of mucoid S. pyogenes and drug resistance trends should be monitored in the future. PMID:24727832

  10. 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.

  11. 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

  12. Rapid detection of Streptococcus pyogenes in pediatric patient specimens by DNA probe.

    PubMed Central

    Steed, L L; Korgenski, E K; Daly, J A

    1993-01-01

    A chemiluminescent DNA probe test (Group A Streptococcus Direct Test; Gen-Probe, Inc., San Diego, Calif.) for rapid, direct detection of cRNA of Streptococcus pyogenes in throat swabs was compared with conventional culture and identification techniques. Throat swabs from 277 patients suspected of having streptococcal pharyngitis were examined. By DNA probe alone, 10 specimens were positive, 51 were positive by both assays, and 8 were positive by culture alone. Thus, DNA probe sensitivity, specificity, and positive and negative predictive values were 86, 95, 84, and 96%, respectively. Including an indeterminate category, sensitivity, specificity, and positive and negative predictive values were 89, 96, 86, and 97%, respectively. After discrepancy testing, these values for the raw data improved to 90, 98, 93, and 97%, respectively. None of the 24 specimens that grew non-S. pyogenes beta-hemolytic streptococci in culture were positive by the DNA probe. Because mucoid S. pyogenes strains are more virulent than nonmucoid strains, 24 isolates were retrospectively tested with the DNA probe to ensure that both types would be detected equally well. Isolates were examined in pure cultures as well as mixed with representative normal oral flora. There was no statistical difference in detection of any of the four groups. Group A Streptococcus Direct Test is a rapid, sensitive, and specific test for S. pyogenes. PMID:8263185

  13. 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

  14. 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.

  15. Clinical and microbiologic characteristics of invasive Streptococcus pyogenes infections in north and south India.

    PubMed

    Haggar, Axana; Nerlich, Andreas; Kumar, Rajesh; Abraham, Vinod J; Brahmadathan, Kootallur N; Ray, Pallab; Dhanda, Vanita; Joshua, John Melbin Jose; Mehra, Narinder; Bergmann, Rene; Chhatwal, G Singh; Norrby-Teglund, Anna

    2012-05-01

    The lack of epidemiologic data on invasive Streptococcus pyogenes infections in many developing countries is concerning, as S. pyogenes infections are commonly endemic in these areas. Here we present the results of the first prospective surveillance study of invasive Streptococcus pyogenes infections in India. Fifty-four patients with invasive S. pyogenes infections were prospectively enrolled at two study sites, one in the north and one in the south of India. Sterile-site isolates were collected, and clinical information was documented using a standardized questionnaire. Available acute-phase sera were tested for their ability to inhibit superantigens produced by the patient's own isolate using a cell-based neutralizing assay. The most common clinical presentations were bacteremia without focus (30%), pneumonia (28%), and cellulitis (17%). Only two cases of streptococcal toxic shock syndrome and no cases of necrotizing fasciitis were identified. Characterization of the isolates revealed great heterogeneity, with 32 different emm subtypes and 29 different superantigen gene profiles being represented among the 49 sterile-site isolates. Analyses of acute-phase sera showed that only 20% of the cases in the north cohort had superantigen-neutralizing activity in their sera, whereas 50% of the cases from the south site had neutralizing activity. The results demonstrate that there are important differences in both clinical presentation and strain characteristics between invasive S. pyogenes infections in India and invasive S. pyogenes infections in Western countries. The findings underscore the importance of epidemiologic studies on streptococcal infections in India and have direct implications for current vaccine developments.

  16. 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.

  17. 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

  18. Streptococcus pyogenes CAMP factor attenuates phagocytic activity of RAW 264.7 cells.

    PubMed

    Kurosawa, Mie; Oda, Masataka; Domon, Hisanori; Saitoh, Issei; Hayasaki, Haruaki; Terao, Yutaka

    2016-02-01

    Streptococcus pyogenes produces molecules that inhibit the function of human immune system, thus allowing the pathogen to grow and spread in tissues. It is known that S. pyogenes CAMP factor increases erythrocytosis induced by Staphylococcus aureus β-hemolysin. However, the effects of CAMP factor for immune cells are unclear. In this study, we investigated the effects of CAMP factor to macrophages. Western blotting analysis demonstrated that all examined strains expressed CAMP factor protein. In the presence of calcium or magnesium ion, CAMP factor was significantly released in the supernatant. In addition, both culture supernatant from S. pyogenes strain SSI-9 and recombinant CAMP factor dose-dependently induced vacuolation in RAW 264.7 cells, but the culture supernatant from Δcfa isogenic mutant strain did not. CAMP factor formed oligomers in RAW 264.7 cells in a time-dependent manner. CAMP factor suppressed cell proliferation via G2 phase cell cycle arrest without inducing cell death. Furthermore, CAMP factor reduced the uptake of S. pyogenes and phagocytic activity indicator by RAW 264.7 cells. These results suggest that CAMP factor works as a macrophage dysfunction factor. Therefore, we conclude that CAMP factor allows S. pyogenes to escape the host immune system, and contribute to the spread of streptococcal infection.

  19. 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.

  20. Inactivation of the Rgg2 transcriptional regulator ablates the virulence of Streptococcus pyogenes.

    PubMed

    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.

  1. A comprehensive analysis of the Streptococcus pyogenes and human plasma protein interaction network.

    PubMed

    Sjöholm, Kristoffer; Karlsson, Christofer; Linder, Adam; Malmström, Johan

    2014-07-01

    Streptococcus pyogenes is a major human bacterial pathogen responsible for severe and invasive disease associated with high mortality rates. The bacterium interacts with several human blood plasma proteins and clarifying these interactions and their biological consequences will help to explain the progression from mild to severe infections. In this study, we used a combination of mass spectrometry (MS) based techniques to comprehensively quantify the components of the S. pyogenes-plasma protein interaction network. From an initial list of 181 interacting human plasma proteins defined using liquid chromatography (LC)-MS/MS analysis we further subdivided the interacting protein list using selected reaction monitoring (SRM) depending on the level of enrichment and protein concentration on the bacterial surface. The combination of MS methods revealed several previously characterized interactions between the S. pyogenes surface and human plasma along with many more, so far uncharacterised, possible plasma protein interactions with S. pyogenes. In follow-up experiments, the combination of MS techniques was applied to study differences in protein binding to a S. pyogenes wild type strain and an isogenic mutant lacking several important virulence factors, and a unique pair of invasive and non-invasive S. pyogenes isolates from the same patient. Comparing the plasma protein-binding properties of the wild type and the mutant and the invasive and non-invasive S. pyogenes bacteria revealed considerable differences, underlining the significance of these protein interactions. The results also demonstrate the power of the developed mass spectrometry method to investigate host-microbial relationships with a large proteomics depth and high quantitative accuracy.

  2. 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

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

    PubMed

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

    2011-05-01

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

  4. Kinetic characterization of arginine deiminase and carbamate kinase from Streptococcus pyogenes M49.

    PubMed

    Hering, Silvio; Sieg, Antje; Kreikemeyer, Bernd; Fiedler, Tomas

    2013-09-01

    Streptococcus pyogenes (group A Streptococcus, GAS) is an important human pathogen causing mild superficial infections of skin and mucous membranes, but also life-threatening systemic diseases. S. pyogenes and other prokaryotic organisms use the arginine deiminase system (ADS) for survival in acidic environments. In this study, the arginine deiminase (AD), and carbamate kinase (CK) from S. pyogenes M49 strain 591 were heterologously expressed in Escherichia coli DH5α, purified, and kinetically characterized. AD and CK from S. pyogenes M49 share high amino acid sequence similarity with the respective enzymes from Lactococcus lactis subsp. lactis IL1403 (45.6% and 53.5% identical amino acids) and Enterococcus faecalis V583 (66.8% and 66.8% identical amino acids). We found that the arginine deiminase of S. pyogenes is not allosterically regulated by the intermediates and products of the arginine degradation (e.g., ATP, citrulline, carbamoyl phosphate). The Km and Vmax values for arginine were 1.13±0.12mM (mean±SD) and 1.51±0.07μmol/min/mg protein. The carbamate kinase is inhibited by ATP but unaffected by arginine and citrulline. The Km and Vmax values for ADP were 0.72±0.08mM and 1.10±0.10μmol/min/mg protein and the Km for carbamoyl phosphate was 0.65±0.07mM. The optimum pH and temperature for both enzymes were 6.5 and 37°C, respectively.

  5. 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

  6. Molecular analysis of an outbreak of lethal postpartum sepsis caused by Streptococcus pyogenes.

    PubMed

    Turner, Claire E; Dryden, Matthew; Holden, Matthew T G; Davies, Frances J; Lawrenson, Richard A; Farzaneh, Leili; Bentley, Stephen D; Efstratiou, Androulla; Sriskandan, Shiranee

    2013-07-01

    Sepsis is now the leading direct cause of maternal death in the United Kingdom, and Streptococcus pyogenes is the leading pathogen. We combined conventional and genomic analyses to define the duration and scale of a lethal outbreak. Two postpartum deaths caused by S. pyogenes occurred within 24 h; one was characterized by bacteremia and shock and the other by hemorrhagic pneumonia. The women gave birth within minutes of each other in the same maternity unit 2 days earlier. Seven additional infections in health care and household contacts were subsequently detected and treated. All cluster-associated S. pyogenes isolates were genotype emm1 and were initially indistinguishable from other United Kingdom emm1 isolates. Sequencing of the virulence gene sic revealed that all outbreak isolates had the same unique sic type. Genome sequencing confirmed that the cluster was caused by a unique S. pyogenes clone. Transmission between patients occurred on a single day and was associated with casual contact only. A single isolate from one patient demonstrated a sequence change in sic consistent with longer infection duration. Transmission to health care workers was traced to single clinical contacts with index cases. The last case was detected 18 days after the first case. Following enhanced surveillance, the outbreak isolate was not detected again. Mutations in bacterial regulatory genes played no detectable role in this outbreak, illustrating the intrinsic ability of emm1 S. pyogenes to spread while retaining virulence. This fast-moving outbreak highlights the potential of S. pyogenes to cause a range of diseases in the puerperium with rapid transmission, underlining the importance of immediate recognition and response by clinical infection and occupational health teams.

  7. Characterization of levofloxacin non-susceptible clinical Streptococcus pyogenes isolated in the central part of Italy.

    PubMed

    Petrelli, D; Di Luca, M C; Prenna, M; Bernaschi, P; Repetto, A; Vitali, L A

    2014-02-01

    We investigated the prevalence, genetics, and clonality of fluoroquinolone non-susceptible isolates of Streptococcus pyogenes in the central part of Italy. S. pyogenes strains (n = 197) were isolated during 2012 from patients with tonsillopharyngitis, skin, wound or invasive infections and screened for fluoroquinolone non-susceptibility (resistance to norfloxacin and levofloxacin minimum inhibitory concentration (MIC) = 2 mg/L) following EUCAST guidelines. First-step topoisomerase parC and gyrA substitutions were investigated using sequencing analysis. Clonality was determined by pulsed field gel electrophoresis (PFGE; SmaI digestion) and by emm typing. The fluoroquinolone non-susceptible phenotype was identified in 18 isolates (9.1 %) and correlated with mutations in parC, but not in gyrA, the most frequent leading to substitution of the serine at position 79 with an alanine. Most of the fluoroquinolone non-susceptible isolates belonged to the emm-type 6, even if other emm-types were also represented (emm75, emm89, and emm2). A significant level of association was measured between PFGE and both emm type and substitutions in parC. The prevalence of fluoroquinolone non-susceptible Streptococcus pyogenes isolates in Italy is of concern and, although the well-known emm type 6 is dominant, other types are appearing and spreading.

  8. Antibiofilm activity of coral-associated bacteria against different clinical M serotypes of Streptococcus pyogenes.

    PubMed

    Thenmozhi, Ramalingam; Nithyanand, Paramasivam; Rathna, Janarthanam; Pandian, Shunmugiah Karutha

    2009-12-01

    Streptococcus pyogenes is the frequent cause of purulent infections in humans. Formation of a biofilm is one of the important aspects of its pathogenicity. Streptococcus pyogenes biofilm communities tend to exhibit significant tolerance to antimicrobial challenge during infections. Exploring novel targets against biofilm-forming pathogens is therefore an important alternative treatment measure. We attempted to screen marine bacteria, especially coral-associated bacteria (CAB), for antibiofilm activity against streptococcal biofilm formation. The bacterial biofilms were quantified by crystal violet staining. Of 43 CAB isolates, nine clearly demonstrated antibiofilm activity. At biofilm inhibitory concentrations (BIC), biofilm formation was reduced up to 80%, and sub-BIC (0.5 and 0.25 BIC) significantly reduced biofilm formation by up to 60% and 40-60%, respectively. Extracts of Bacillus horikoshii (E6) displayed efficient antibiofilm activity. As quorum sensing (QS) and cell surface hydrophobicity (CSH) are crucial factors for biofilm formation in S. pyogenes, the CAB were further screened for QS inhibition properties and CSH reduction properties. This study reveals the antibiofilm and QS inhibition property of CAB. PMID:19845763

  9. Novel impedimetric immunosensor for detection of pathogenic bacteria Streptococcus pyogenes in human saliva.

    PubMed

    Ahmed, Asif; Rushworth, Jo V; Wright, John D; Millner, Paul A

    2013-12-17

    Streptococcus pyogenes , also known as group A streptococcus (GAS), is a Gram positive human pathogen responsible for invasive and noninvasive human infections with a high incidence rate. Traditional detection methods involve cell culture and PCR, which are limited by long processing times or the need for high cost equipment. Impedance-based electrochemical immunosensors provide an alternative by which precise and rapid quantitative detection of the organism can help with rapid clinical decisions. To bring a biosensor for point-of-care applications to market, strict optimization of each level of construction and operation is required. In this paper, commercial screen-printed gold electrodes have been used to construct polytyramine (Ptyr)-based immunosensors. Biotin tagged whole antibodies against S. pyogenes were conjugated to Ptyr amine group via biotin-NeutrAvidin coupling. Sensors were optimized at each level of construction, particularly for Ptyr electrodeposition and antibody concentration, to optimize signal and specificity. Scanning electron microscopy, fluorescence microscopy, and on-sensor analysis (HRP conjugated enhanced chemiluminescence-based semiquantitative method) to detect Ptyr surface amine and bound antibody were performed as supporting techniques. Cumulative and single shot incubations had shown detection range of 100 to 10(5) cells per 10 μL and 100 to 10(4) cells per 10 μL of bacteria in PBS, respectively. Sensors were also able to specifically detect S. pyogenes in 50% (v/v) human saliva, with good selectivity and low cross-reactivity.

  10. 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

  11. 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

  12. Novel bacteriophage lysin with broad lytic activity protects against mixed infection by Streptococcus pyogenes and methicillin-resistant Staphylococcus aureus.

    PubMed

    Gilmer, Daniel B; Schmitz, Jonathan E; Euler, Chad W; Fischetti, Vincent A

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pyogenes (group A streptococcus [GrAS]) cause serious and sometimes fatal human diseases. They are among the many Gram-positive pathogens for which resistance to leading antibiotics has emerged. As a result, alternative therapies need to be developed to combat these pathogens. We have identified a novel bacteriophage lysin (PlySs2), derived from a Streptococcus suis phage, with broad lytic activity against MRSA, vancomycin-intermediate S. aureus (VISA), Streptococcus suis, Listeria, Staphylococcus simulans, Staphylococcus epidermidis, Streptococcus equi, Streptococcus agalactiae (group B streptococcus [GBS]), S. pyogenes, Streptococcus sanguinis, group G streptococci (GGS), group E streptococci (GES), and Streptococcus pneumoniae. PlySs2 has an N-terminal cysteine-histidine aminopeptidase (CHAP) catalytic domain and a C-terminal SH3b binding domain. It is stable at 50 °C for 30 min, 37 °C for >24 h, 4°C for 15 days, and -80 °C for >7 months; it maintained full activity after 10 freeze-thaw cycles. PlySs2 at 128 μg/ml in vitro reduced MRSA and S. pyogenes growth by 5 logs and 3 logs within 1 h, respectively, and exhibited a MIC of 16 μg/ml for MRSA. A single, 2-mg dose of PlySs2 protected 92% (22/24) of the mice in a bacteremia model of mixed MRSA and S. pyogenes infection. Serially increasing exposure of MRSA and S. pyogenes to PlySs2 or mupirocin resulted in no observed resistance to PlySs2 and resistance to mupirocin. To date, no other lysin has shown such notable broad lytic activity, stability, and efficacy against multiple, leading, human bacterial pathogens; as such, PlySs2 has all the characteristics to be an effective therapeutic.

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

    PubMed

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

    2014-01-01

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

  14. Innate immune response to Streptococcus pyogenes depends on the combined activation of TLR13 and TLR2.

    PubMed

    Fieber, Christina; Janos, Marton; Koestler, Tina; Gratz, Nina; Li, Xiao-Dong; Castiglia, Virginia; Aberle, Marion; Sauert, Martina; Wegner, Mareike; Alexopoulou, Lena; Kirschning, Carsten J; Chen, Zhijian J; von Haeseler, Arndt; Kovarik, Pavel

    2015-01-01

    Innate immune recognition of the major human-specific Gram-positive pathogen Streptococcus pyogenes is not understood. Here we show that mice employ Toll-like receptor (TLR) 2- and TLR13-mediated recognition of S. pyogenes. These TLR pathways are non-redundant in the in vivo context of animal infection, but are largely redundant in vitro, as only inactivation of both of them abolishes inflammatory cytokine production by macrophages and dendritic cells infected with S. pyogenes. Mechanistically, S. pyogenes is initially recognized in a phagocytosis-independent manner by TLR2 and subsequently by TLR13 upon internalization. We show that the TLR13 response is specifically triggered by S. pyogenes rRNA and that Tlr13-/- cells respond to S. pyogenes infection solely by engagement of TLR2. TLR13 is absent from humans and, remarkably, we find no equivalent route for S. pyogenes RNA recognition in human macrophages. Phylogenetic analysis reveals that TLR13 occurs in all kingdoms but only in few mammals, including mice and rats, which are naturally resistant against S. pyogenes. Our study establishes that the dissimilar expression of TLR13 in mice and humans has functional consequences for recognition of S. pyogenes in these organisms.

  15. The effect of the flavonol morin on adhesion and aggregation of Streptococcus pyogenes.

    PubMed

    Green, Angharad E; Rowlands, Richard S; Cooper, Rose A; Maddocks, Sarah E

    2012-08-01

    The effect of the flavonol morin on Streptococcus pyogenes biofilm growth was determined using a static biofilm model, in which reduced biofilm biomass was observed in the presence of morin, suggesting that morin inhibited biofilm development. Morin at concentrations exceeding 225 μM had the greatest impact on biofilm biomass causing reductions of up to 65%, which was found to be statistically significant. Morin was also shown to induce rapid bacterial aggregation. Approximately 55% of S. pyogenes in liquid suspension aggregated when incubated with morin at concentrations of 275 and 300 μM for 120 min, compared to the control group in which only 10% of the cells aggregated, this was also shown to be statistically significant.

  16. Predominant role of msr(D) over mef(A) in macrolide resistance in Streptococcus pyogenes.

    PubMed

    Zhang, Yan; Tatsuno, Ichiro; Okada, Ryo; Hata, Nanako; Matsumoto, Masakado; Isaka, Masanori; Isobe, Ken-ichi; Hasegawa, Tadao

    2016-01-01

    In Japan, the number of patients with streptococcal toxic shock syndrome is reported to be increasing. mef(A) gene-positive macrolide-resistant emm1 strains are thought to possibly contribute to the rise in the frequency of STSS. Although analyses of macrolide-resistant mechanisms, including mef(A) resistance, have been performed mainly in Streptococcus pneumoniae, the role of this gene in Streptococcus pyogenes has not been completely investigated. Therefore, to the best of our knowledge, we established the first mef(A)-knockout strain using an emm1-type S. pyogenes strain, and tested its susceptibility to erythromycin, clarithromycin and azithromycin. We found that the antimicrobial susceptibilities were almost identical to those of the parental strain. Hence, we established a knockout strain for another gene, msr(D), that is located immediately downstream of mef(A). The macrolide resistances of the resulting strain significantly decreased, and were further altered when both mef(A) and msr(D) were knocked out. The introduction of the msr(D) gene into a macrolide-sensitive strain conferred more resistance than the introduction of the mef(A) gene. The erythromycin susceptibilities of knockout strains were further dissected using two additional emm4- and emm75-type S. pyogenes strains. We found almost identical results for both strains except for the mef(A) knockout emm4 type, whose susceptibility was altered, although the change was less than that for the msr(D) knockout. These results suggest that both mef(A) and msr(D) are involved in macrolide resistance in S. pyogenes, and that the msr(D) gene plays a more predominant role in macrolide resistance than mef(A).

  17. Pyogenic knee arthritis caused by group A β-hemolytic Streptococcus: a toxic shock-prevented case.

    PubMed

    Goto, Masafumi; Gotoh, Masafumi; Mitsui, Yasuhiro; Shibata, Hideaki; Okawa, Takahiro; Higuchi, Fujio; Shiba, Naoto

    2014-01-01

    Pyogenic knee arthritis caused by group A β-hemolytic Streptococcus (GAS) is rare. GAS sometimes causes group A β-hemolytic streptococcal toxic shock syndrome. We encountered a case of pyogenic knee arthritis caused by GAS that resolved after appropriate treatment (emergency arthroscopic synovectomy and medication) administered within 48 h of onset. In cases of a history of another infection with acute knee joint pain, the possibility of GAS-induced pyogenic knee arthritis should be considered, and proper treatment should be administered immediately.

  18. 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.

  19. Murine Vaginal Colonization Model for Investigating Asymptomatic Mucosal Carriage of Streptococcus pyogenes

    PubMed Central

    Watson, Michael E.; Nielsen, Hailyn V.; Hultgren, Scott J.

    2013-01-01

    While many virulence factors promoting Streptococcus pyogenes invasive disease have been described, specific streptococcal factors and host properties influencing asymptomatic mucosal carriage remain uncertain. To address the need for a refined model of prolonged S. pyogenes asymptomatic mucosal colonization, we have adapted a preestrogenized murine vaginal colonization model for S. pyogenes. In this model, derivatives of strains HSC5, SF370, JRS4, NZ131, and MEW123 established a reproducible, asymptomatic colonization of the vaginal mucosa over a period of typically 3 to 4 weeks' duration at a relatively high colonization efficiency. Prior treatment with estradiol prolonged streptococcal colonization and was associated with reduced inflammation in the colonized vaginal epithelium as well as a decreased leukocyte presence in vaginal fluid compared to the levels of inflammation and leukocyte presence in non-estradiol-treated control mice. The utility of our model for investigating S. pyogenes factors contributing to mucosal carriage was verified, as a mutant with a mutation in the transcriptional regulator catabolite control protein A (CcpA) demonstrated significant impairment in vaginal colonization. An assessment of in vivo transcriptional activity in the CcpA− strain for several known CcpA-regulated genes identified significantly elevated transcription of lactate oxidase (lctO) correlating with excessive generation of hydrogen peroxide to self-lethal levels. Deletion of lctO did not impair colonization, but deletion of lctO in a CcpA− strain prolonged carriage, exceeding even that of the wild-type strain. Thus, while LctO is not essential for vaginal colonization, its dysregulation is deleterious, highlighting the critical role of CcpA in promoting mucosal colonization. The vaginal colonization model should prove effective for future analyses of S. pyogenes mucosal colonization. PMID:23460515

  20. 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

  1. 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.

  2. Two distinct pathways for the invasion of Streptococcus pyogenes in non-phagocytic cells.

    PubMed

    Molinari, G; Rohde, M; Guzmán, C A; Chhatwal, G S

    2000-04-01

    Adherence to and invasion of epithelial cells represent important pathogenic mechanisms of Streptococcus pyogenes. A fibronectin-binding surface protein of S. pyogenes, Sfbl protein, has been implicated in both adherence and invasion processes. Invasion of Sfbl-containing strains has been suspected to be responsible for the failure of antibiotics treatment to eradicate S. pyogenes. In this study, we tested the adherence and invasion properties of two well-characterized clinical isolates: A40, which expresses Sfbl; and A8, which is Sfbl negative and is unable to bind fibronectin. In strain A40, Sfbl was the main factor required for attachment and invasion by using fibronectin as a bridging molecule and the alpha5beta1 integrin as cellular receptor. The uptake process was characterized by the generation of large membrane invaginations at the bacteria-cell interface without evidence of actin recruitment or cellular injury. A40 cells were located in phagosomes and, only 24 h after infection, a consistent part of the bacterial population reached the cytoplasm. In contrast, uptake of strain A8 required major rearrangements of cytoskeletal proteins underneath attached bacteria. In A8, a proteinaceous moiety was involved, which does not interact with alpha5beta1 or need any known bridging molecule. Bacterial attachment stimulated elongation and massive recruitment of neighbouring microvilli, which fused to surround streptococcal chains. They led to the generation of large pseudopod-like structures, which engulfed bacteria that were rapidly released and replicated in the cytoplasm. The identification of two completely different uptake pathways reported here provided further evidence regarding the diversity of S. pyogenes isolates and might contribute towards understanding the pathogenesis and persistence of S. pyogenes.

  3. 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.

  4. [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

  5. ICESp1116, the genetic element responsible for erm(B)-mediated, inducible resistance to erythromycin in Streptococcus pyogenes.

    PubMed

    Brenciani, Andrea; Tiberi, Erika; Morici, Eleonora; Oryasin, Erman; Giovanetti, Eleonora; Varaldo, Pietro E

    2012-12-01

    ICESp1116, responsible for erm(B)-mediated, inducible erythromycin resistance in Streptococcus pyogenes, was comprehensively characterized, and its chromosomal integration site was determined. It displayed a unique mosaic organization consisting of a scaffold, related to TnGallo1 from Streptococcus gallolyticus, with two inserted fragments separated by IS1216. One fragment, containing erm(B), displayed high-level identity to a portion of the S. pyogenes plasmid pSM19035; the other, containing a truncated tet(M) gene, displayed high-level identity to the right-hand portion of Clostridium difficile Tn5397.

  6. 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

  7. 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

  8. 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

  9. 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

  10. Extensive diversity of Streptococcus pyogenes in a remote human population reflects global-scale transmission rather than localised diversification.

    PubMed

    Towers, Rebecca J; Carapetis, Jonathan R; Currie, Bart J; Davies, Mark R; Walker, Mark J; Dougan, Gordon; Giffard, Philip M

    2013-01-01

    The Indigenous population of the Northern Territory of Australia (NT) suffers from a very high burden of Streptococcus pyogenes disease, including cardiac and renal sequelae. The aim of this study was to determine if S. pyogenes isolated from this population represent NT endemic strains, or conversely reflect strains with global distribution. emm sequence typing data were used to select 460 S. pyogenes isolates representing NT S. pyogenes diversity from 1987-2008. These isolates were genotyped using either multilocus sequence typing (MLST) or a high resolution melting-based MLST surrogate (Minim typing). These data were combined with MLST data from other studies on NT S. pyogenes to yield a set of 731 MLST or Minim typed isolates for analysis. goeBURST analysis of MLST allelic profiles and neighbour-joining trees of the MLST allele sequences revealed that a large proportion of the known global S. pyogenes MLST-defined diversity has now been found in the NT. Specifically, fully sequence typed NT isolates encompass 19% of known S. pyogenes STs and 43% of known S. pyogenes MLST alleles. These analyses provided no evidence for major NT-endemic strains, with many STs and MLST alleles shared between the NT and the rest of the world. The relationship between the number of known Minim types, and the probability that a Minim type identified in a calendar year would be novel was determined. This revealed that Minim types typically persist in the NT for >1 year, and indicate that the majority of NT Minim types have been identified. This study revealed that many diverse S. pyogenes strains exhibit global scale mobility that extends to isolated populations. The burden of S. pyogenes disease in the NT is unlikely to be due to the nature of NT S. pyogenes strains, but is rather a function of social and living conditions.

  11. 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

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

    PubMed

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

    2015-06-01

    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.

  13. Streptococcus pyogenes arginine and citrulline catabolism promotes infection and modulates innate immunity.

    PubMed

    Cusumano, Zachary T; Watson, Michael E; Caparon, Michael G

    2014-01-01

    A bacterium's ability to acquire nutrients from its host during infection is an essential component of pathogenesis. For the Gram-positive pathogen Streptococcus pyogenes, catabolism of the amino acid arginine via the arginine deiminase (ADI) pathway supplements energy production and provides protection against acid stress in vitro. Its expression is enhanced in murine models of infection, suggesting an important role in vivo. To gain insight into the function of the ADI pathway in pathogenesis, the virulence of mutants defective in each of its enzymes was examined. Mutants unable to use arginine (ΔArcA) or citrulline (ΔArcB) were attenuated for carriage in a murine model of asymptomatic mucosal colonization. However, in a murine model of inflammatory infection of cutaneous tissue, the ΔArcA mutant was attenuated but the ΔArcB mutant was hyperattenuated, revealing an unexpected tissue-specific role for citrulline metabolism in pathogenesis. When mice defective for the arginine-dependent production of nitric oxide (iNOS(-/-)) were infected with the ΔArcA mutant, cutaneous virulence was rescued, demonstrating that the ability of S. pyogenes to utilize arginine was dispensable in the absence of nitric oxide-mediated innate immunity. This work demonstrates the importance of arginine and citrulline catabolism and suggests a novel mechanism of virulence by which S. pyogenes uses its metabolism to modulate innate immunity through depletion of an essential host nutrient.

  14. The Streptococcus pyogenes NAD+ Glycohydrolase Modulates Epithelial Cell PARylation and HMGB1 Release

    PubMed Central

    Chandrasekaran, Sukantha; Caparon, Michael G.

    2015-01-01

    Streptococcus pyogenes uses the cytolysin Streptolysin O (SLO) to translocate an enzyme, the S. pyogenes NAD+ glycohydrolase (SPN), into the host cell cytosol. However, the function of SPN in this compartment is not known. As a complication, many S. pyogenes strains express a SPN variant lacking NAD+ glycohydrolase (NADase) activity. Here, we show that SPN modifies several SLO- and NAD+-dependent host cell responses in patterns that correlate with NADase activity. SLO pore formation results in hyper-activation of the cellular enzyme Poly-ADP-ribose Polymerase-1 (PARP-1) and production of polymers of Poly-ADP-ribose (PAR). However, while SPN NADase activity moderates PARP-1 activation and blocks accumulation of PAR, these processes continued unabated in the presence of NADase-inactive SPN. Temporal analyses revealed that while PAR production is initially independent of NADase activity, PAR rapidly disappears in the presence of NADase-active SPN, host cell ATP is depleted and the pro-inflammatory mediator High-Mobility Group Box-1 (HMGB1) protein is released from the nucleus by a PARP-1 dependent mechanism. In contrast, HMGB1 is not released in response to NADase-inactive SPN and instead the cells release elevated levels of IL-8 and TNFα. Thus, SPN and SLO combine to induce cellular responses subsequently influenced by the presence or absence of NADase activity. PMID:25818652

  15. Macrolide resistance in Streptococcus pyogenes isolates from throat infections in the region of Aachen, Germany.

    PubMed

    Brandt, C M; Honscha, M; Truong, N D; Holland, R; Hövener, B; Bryskier, A; Lütticken, R; Reinert, R R

    2001-01-01

    Macrolide-resistance was assessed in 216 consecutive Streptococcus pyogenes isolates from throat infections in the region of Aachen, Germany. Seventeen isolates were resistant to erythromycin: 12 isolates revealed a macrolide (M) phenotype and harbored mefA, and five strains expressed an inducible macrolide-lincosamide-streptogramin B (MLSB) phenotype of which four strains harbored ermA(TR) and one strain contained ermB(AM). Telithromycin (HMR 3647) and quinupristin/dalfopristin remained active particularly against the ermA(TR)-containing S. pyogenes isolates studied. Random amplified polymorphic DNA analysis identified multiple clones among erythromycin-resistant strains, but did not discriminate beyond the emm-type. mefA was present in three isolates either with emm2, emm12, or emm75, and in nine isolates with emm4. All four strains with ermA(TR) contained emm77, and the single strain with ermB(AM) harbored emm1. Despite the relative low rate of macrolide-resistance, these data suggest that at least three different macrolide-resistance determinants are prevalent in Germany and that mefA has spread rapidly into multiple clones of S. pyogenes.

  16. 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

  17. Autonomous expression of the slo gene of the bicistronic nga-slo operon of Streptococcus pyogenes.

    PubMed

    Savic, Dragutin J; McShan, William M; Ferretti, Joseph J

    2002-05-01

    A recent model for cytolysin-mediated translocation in Streptococcus pyogenes proposes that NAD-glycohydrolase is translocated through streptolysin O-generated pores into a host cell (J. Madden, N. Ruiz, and M. Caparon, Cell 104:143-152, 2001). This model also assumes that the NAD-glycohydrolase (nga) and streptolysin O (slo) genes that code for these products are organized in an operon-like structure expressed from a single promoter only (nga). We expand this model by showing that slo possesses its own autonomous promoter, which is located 155 bp upstream of the slo gene. Under experimental conditions in which S. pyogenes is grown in THY medium, the strength of the slo promoter, as measured by the activity of a lacZ reporter gene, resulted in low but highly reproducible values. Finally, we demonstrated that sloR, a S. pyogenes gene that closely resembles the Clostridium perfringens pfoR gene, exerts a negative effect on the expression of the slo gene. PMID:11953421

  18. 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

  19. 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

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

    PubMed

    Wong, Samson Sy; Yuen, Kwok-Yung

    2012-07-01

    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.

  1. 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

  2. Development of a recombinant fusion protein vaccine formulation to protect against Streptococcus pyogenes.

    PubMed

    Morefield, Garry; Touhey, Graham; Lu, Fangjia; Dunham, Anisa; HogenEsch, Harm

    2014-06-24

    Diseases resulting from infection by group A streptococcus (GAS) are an increasing burden on global health. A novel vaccine was developed targeting infection by Streptococcus pyogenes. The vaccine incorporates a recombinant fusion protein antigen (SpeAB) which was engineered by combining inactive mutant forms of streptococcal pyrogenic exotoxin A (SpeA) and streptococcal pyrogenic exotoxin B (SpeB) from S. pyogenes. A rational, scientific approach to vaccine development was utilized to determine optimal formulation conditions with aluminum adjuvants. Investigations of the pH stability profile of SpeAB concluded the antigen was most stable near pH 8. Incorporation of the stabilizers sucrose and mannitol significantly enhanced the stability of the antigen. Vaccines were formulated in which most of the SpeAB was adsorbed to the adjuvant or remained in solution. A SpeAB vaccine formulation, stabilized with sucrose, in which the antigen remains adsorbed to the aluminum adjuvant retained the greatest potency as determined by evaluation of neutralizing antibody responses in mice. This vaccine has great potential to provide a safe and effective method for prevention of GAS disease.

  3. 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. PMID:27630838

  4. Azithromycin-sulfonamide conjugates as inhibitors of resistant Streptococcus pyogenes strains.

    PubMed

    Bukvić Krajacić, Mirjana; Novak, Predrag; Cindrić, Mario; Brajsa, Karmen; Dumić, Miljenko; Kujundzić, Nedjeljko

    2007-02-01

    Novel hybrid compounds 6a-6d, conjugates of 15-membered azalides and sulfonamides, i.e. unsubstituted, 4-aryl- and 4-heteroaryl-aminosulfonyl derivatives of 9a-[N'-(phenylcarbamoyl)]-9-deoxo-9-dihydro-9a-aza-9a-homoerythromycin A were synthesized and characterized by IR, one- and two-dimensional NMR spectroscopies and MALDI-TOF and MS/MS mass spectrometry. The new compounds were evaluated in vitro against a panel of sensitive and resistant Gram-positive and Gram-negative bacterial strains. 9a-{N'-[4-(Aminosulfonyl)phenyl]carbamoyl}--(6a) and 9a-{N'-[4-(phenylaminosulfonyl)phenyl]carbamoyl}--(6b) derivatives showed improvements in activity against inducible resistant Streptococcus pyogenes in comparison with macrolide antibiotic azithromycin and starting material 9-deoxo-9-dihydro-9a-aza-9a-homoerythromycin A (2). In addition, the synthesized azithromycin-sulfonamide conjugates 6a-6d showed good antibacterial activity against sensitive S. pyogenes and Streptococcus pneumoniae strains. The kinetics of degradation in the artificial gastric juice showed that the most active compounds, 6a and 6b, exhibited azithromycin like stability. The cleavage of the cladinose sugar was found to be the main decomposition pathway leading to inactive 7a and 7b, prepared also as analytical standards by the alternative synthetic route together with 7c and 7d.

  5. 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.

  6. 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

  7. 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.

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

    PubMed

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

    2016-01-01

    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

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

    PubMed

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

    2016-03-17

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

  11. Cysteine proteinase from Streptococcus pyogenes enables evasion of innate immunity via degradation of complement factors.

    PubMed

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

    2013-05-31

    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.

  12. [Streptococcus pyogenes: penicillin and erythromycin susceptibility in the cities of Neuquen and Cipolletti].

    PubMed

    Soriano, S V; Brasili, S; Saiz, M; Carranza, C; Vidal, P; Calderón, J; Lopardo, H A

    2000-01-01

    Penicillin resistance has not yet been detected in Streptococcus pyogenes. However macrolide-resistant streptococci have emerged in several countries. Only low rates of erythromycin-resistant S. pyogenes were reported in Argentina, with the exception of a 11.1% observed in Mendoza. The aim of the present study was to determine the susceptibility to penicillin and to erythromycin of 251 consecutive clinically-significant isolates of S. pyogenes obtained from four centers of Cipolletti and Neuquén during the period April-December 1998. The double disk test with erythromycin and clindamycin disks was employed as a screening method to detect ERY-resistant streptococci and to determine the phenotype of macrolide resistance. Disk diffusion was also employed for determining penicillin susceptibility. Macrolide-resistant isolates were also tested for penicillin, ceftriaxone, erythromycin, clindamycin and azithromycin susceptibility by the agar dilution method. Additionally they were also tested for erythromycin susceptibility by E-test (AB Biodisk, Solna, Sweden). All streptococci studied were susceptible to penicillin and thirty of them (12.0%) were resistant to erythromycin. All these resistant isolates were also resistant to azithromycin but susceptible to ceftriaxone and clindamycin. They showed the phenotype M (probably efflux-mediated mechanism) and the MICs of erythromycin ranged between 8 and 16 micrograms/ml. According to these results we conclude that in spite of universal susceptibility to penicillin in S. pyogenes, macrolide resistance is a matter of concern in Neuquén and Cipolletti. At least in those cities it appears to be necessary to routinely perform macrolide susceptibility tests in beta-hemolytic streptococci.

  13. Draft genome sequences of two Streptococcus pyogenes strains involved in abnormal sharp raised scarlet fever in China, 2011.

    PubMed

    You, Yuanhai; Yang, Xianwei; Song, Yanyan; Yan, Xiaomei; Yuan, Yanting; Li, Dongfang; Yan, Yanfeng; Wang, Haibin; Tao, Xiaoxia; Li, Leilei; Jiang, Xihong; Zhou, Hao; Xiao, Di; Jin, Lianmei; Feng, Zijian; Yang, Ruifu; Luo, Fengji; Cui, Yujun; Zhang, Jianzhong

    2012-11-01

    A scarlet fever outbreak caused by Streptococcus pyogenes occurred in China in 2011. To determine the genomic features of the outbreak strains, we deciphered genomes of two strains isolated from the regions with the highest incidence rates. The sequences will provide valuable information for comprehensive study of mechanisms related to this outbreak.

  14. Frequency of Spontaneous Resistance to Peptide Deformylase Inhibitor GSK1322322 in Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae

    PubMed Central

    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

    2015-01-01

    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

  15. 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).

  16. 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

  17. 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

  18. HMGB1 in severe soft tissue infections caused by Streptococcus pyogenes.

    PubMed

    Johansson, Linda; Snäll, Johanna; Sendi, Parham; Linnér, Anna; Thulin, Pontus; Linder, Adam; Treutiger, Carl-Johan; Norrby-Teglund, Anna

    2014-01-01

    Extracellular High Mobility Group Box 1 (HMGB1) has been associated with acute and chronic inflammatory conditions. However, little is known about HMGB1 in necrotizing bacterial infections. We hypothesized that the local HMGB1 response is excessive in severe soft tissue infections (STIs), which are characterized by necrosis and hyperinflammation. To explore this, tissue biopsies were collected from patients with varying severity of Streptococcus pyogenes skin and STIs, including erysipelas, cellulitis, and necrotizing fasciitis. Tissue sections were immunostained for HMGB1, S. pyogenes, and inflammatory cell infiltrates and results quantified by acquired computerized image analysis (ACIA). HMGB1 expression increased in parallel to disease severity and was significantly higher in necrotizing fasciitis than in erysipelas (p = 0.0023). Confocal microscopy of sections co-stained for HMGB1 and cell markers revealed both extracellular and cytoplasmic HMGB1, the latter of which was found predominantly in macrophages. To further verify macrophages as main source of activation triggered HMGB1 release, human macrophages were infected with clinical S. pyogenes isolates. The results demonstrated infection triggered release of HMGB1. Dual staining's visualized HMGB1 in areas close to, but not overlapping, with neutrophils, indicating a potential chemotactic role. In vitro transmigration experiments showed a chemotactic effect of HMGB1 on neutrophils. The data furthermore provided in vivo support that HGMB1 may form immunostimulatory complexes with IL-1β. Taken together, the findings provide the first in vivo evidence that HMGB1 is abundant at the local site of severe bacterial STIs and its levels correlated to severity of infections; hence, indicating its potential value as a biomarker for tissue pathology.

  19. Streptococcus pyogenes malate degradation pathway links pH regulation and virulence.

    PubMed

    Paluscio, Elyse; Caparon, Michael G

    2015-03-01

    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.

  20. Transport of. cap alpha. -aminoisobutyric acid by Streptococcus pyogenes and its derived L-form

    SciTech Connect

    Reizer, J.; Panos, C.

    1982-01-01

    We studied the uptake of ..cap alpha..-aminoisobutyric acid (AIB) in Streptococcus pyogenes and its physiologically isotonic L-form. S. pyogenes cells starved for glucose or treated with carbonyl cyanide-m-chlorophenyl hydrazone accumulated limited amounts of AIB. A high apparent K/sub m/ value characterized the glucose-independent transport of AIB. The rate and extent of AIB accumulation significantly increased in the presence of glucose. Two saturable transport components with distinct apparent K/sub m/values characterized glycolysis-coupled transport of AIB. A biphasic Lineweaver-Burk plot was also obtained for L-alanine transport by glycolyzing S. pyogenes cells. AIB seems to share a common transport system(s) with glycine, L- and D-anine, L-serine, and L-valine. This was shown by the competitive exchange efflux of accumulated AIB. About 30% of the AIB uptake was not inhibited by a saturating amount of L-valine, indicating the existence of more than one system for AIB transport, p-Chloromercuribenzoate markedly inhibited the accumulation of AIB by both glycolyzing and glucose-starved cells. In contrast, carbonyl cyanide-m-chlorophenyl hydrazone affected only metabolism-dependent uptake of AIB, which was also sensitive to dinitrophenol, N-ethylmaleimide, iodoacetate, fluoride (NaF), arsenate, and N,N'-dicyclohexylcarbodiimide. These results are interpreted according to the chemiosmotic theory of Mitchell, whereby a proton motive force constitutes the driving force for AIB accumulation. AIB was not accumulated by the L-form. However, a temporary accumulation of AIB by a counterflow mechanism and a saturable system with a low apparent affinity were demonstrated for AIB transport by this organism. We suggest that a deficiency in the coupling of energy to AIB transport is responsible for the apparent lack of active AIB accumulation by the L-form.

  1. 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

  2. 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

  3. [Past and present of streptococcus pyogenes: some pathogenic factors and their genetic determination].

    PubMed

    Totolian, A A

    2015-01-01

    In this review two aspects dealt with Streptococcus pyogenes--one of the leading agent responsible for infectious diseases and another related to their complications in humans worldwide--are given. In the first part of the review the comparative evaluation of laboratory diagnostic approaches and methods used in the second half of the twentieth century and molecular technologies developed during last twenty years are described. In the second part the role of the main microbial pathogenic factors as well as the data on intra- and interspecies genetic exchange with extrachromosomal genetic elements and their influence on biological properties of the pathogen are discussed. Essential for today possibilities for molecular epidemiology of streptococcal pathology approaches must be introduces in diagnostic laboratories within the country.

  4. Antimicrobial susceptibility and macrolide resistance genes in Streptococcus pyogenes collected in Austria and Hungary.

    PubMed

    Gattringer, Rainer; Sauermann, Robert; Lagler, Heimo; Stich, Karin; Buxbaum, Astrid; Graninger, Wolfgang; Georgopoulos, Apostolos

    2004-09-01

    A total of 341 clinical isolates of Streptococcus pyogenes from Vienna, Austria and three Hungarian cities were tested for susceptibility to four macrolides and 12 other antibiotics. All isolates were fully susceptible to penicillin and the other beta-lactams tested. A high level of tetracycline resistance was found in Austria (26.7%) and in Hungary (30.5%). The rate of resistance to erythromycin, clarithromycin and azithromycin was 4.7% in Vienna and 3.7% in the Hungarian communities. In both countries, the MIC(90) values of erythromycin and clarithromycin were 0.12 mg/L and the MIC(90) of josamycin was 0.5mg/L. The M phenotype of resistance conferred by the mefA genes was predominant (n = 9) among the macrolide-resistant isolates (n = 14).

  5. 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

  6. Sequence variability is correlated with weak immunogenicity in Streptococcus pyogenes M protein

    PubMed Central

    Lannergård, Jonas; Kristensen, Bodil M; Gustafsson, Mattias C U; Persson, Jenny J; Norrby-Teglund, Anna; Stålhammar-Carlemalm, Margaretha; Lindahl, Gunnar

    2015-01-01

    The M protein of Streptococcus pyogenes, a major bacterial virulence factor, has an amino-terminal hypervariable region (HVR) that is a target for type-specific protective antibodies. Intriguingly, the HVR elicits a weak antibody response, indicating that it escapes host immunity by two mechanisms, sequence variability and weak immunogenicity. However, the properties influencing the immunogenicity of regions in an M protein remain poorly understood. Here, we studied the antibody response to different regions of the classical M1 and M5 proteins, in which not only the HVR but also the adjacent fibrinogen-binding B repeat region exhibits extensive sequence divergence. Analysis of antisera from S. pyogenes-infected patients, infected mice, and immunized mice showed that both the HVR and the B repeat region elicited weak antibody responses, while the conserved carboxy-terminal part was immunodominant. Thus, we identified a correlation between sequence variability and weak immunogenicity for M protein regions. A potential explanation for the weak immunogenicity was provided by the demonstration that protease digestion selectively eliminated the HVR-B part from whole M protein-expressing bacteria. These data support a coherent model, in which the entire variable HVR-B part evades antibody attack, not only by sequence variability but also by weak immunogenicity resulting from protease attack. PMID:26175306

  7. Active but inoperable thrombin is accumulated in a plasma protein layer surrounding Streptococcus pyogenes.

    PubMed

    Naudin, Clément; Hurley, Sinead M; Malmström, Erik; Plug, Tom; Shannon, Oonagh; Meijers, Joost C M; Mörgelin, Matthias; Björck, Lars; Herwald, Heiko

    2015-10-01

    Activation of thrombin is a critical determinant in many physiological and pathological processes including haemostasis and inflammation. Under physiological conditions many of these functions are involved in wound healing or eradication of an invading pathogen. However, when activated systemically, thrombin can contribute to severe and life-threatening conditions by causing complications such as multiple multi-organ failure and disseminated intravascular coagulation. In the present study we investigated how the activity of thrombin is modulated when it is bound to the surface of Streptococcus pyogenes. Our data show that S. pyogenes bacteria become covered with a proteinaceous layer when incubated with human plasma, and that thrombin is a constituent of this layer. Though the coagulation factor is found attached to the bacteria with a functional active site, thrombin has lost its capacity to interact with its natural substrates and inhibitors. Thus, the interaction of bacteria with human plasma renders thrombin completely inoperable at the streptococcal surface. This could represent a host defense mechanism to avoid systemic activation of coagulation which could be otherwise induced when bacteria enter the circulation and cause systemic infection.

  8. [Susceptibility of Streptococcus pyogenes to macrolides and quinolones in Guadalajara, Spain].

    PubMed

    Rodríguez-Zurita, M E; Solís del Baño, S; Robres Guillén, P; González Praetorius, A; Gimeno Fernández, C; Pérez Pomata, M T; Bisquert Santiago, J

    2003-03-01

    We carried out a retrospective study of the susceptibility of 104 Streptococcus pyogenes strains, which were isolated in 2000 and 2001 from clinical samples of different origins, to penicillin, erythromycin, clindamycin, ofloxacin and levofloxacin. The susceptibility testing was performed using the agar difusion method according to the guidelines of the NCCLS. All of the isolates showed susceptibility to penicillin and clindamycin. However, we detected 11 strains that were resistant to erythromycin (10.6%) and 4 strains resistant to ofloxacin (3.8%). We studied the resistance phenotypes of macrolides and lincosamides using erythromycin and clindamycin discs. Nine of the eleven strains that were resistant to erythromycin showed an M phenotype, while the remaining two showed inducible resistance to clindamycin, thus suggesting an MLS(B) inducible phenotype. No strains with constitutive resistance to erythromycin or clindamycin (MLS(B) constitutive phenotype) were identified. While penicillin is still uniformly active against S. pyogenes, in Guadalajara, there are 10.6% strains that are resistant to 14- and 15-atoms macrolides.

  9. 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

  10. Structural Basis of Streptococcus pyogenes Immunity to its NAD+ Glycohydrolase Toxin

    PubMed Central

    Smith, Craig L.; Ghosh, Joydeep; Elam, Jennifer Stine; Pinkner, Jerome S.; Hultgren, Scott J.; Caparon, Michael G.; Ellenberger, Tom

    2011-01-01

    SUMMARY The virulence of Gram-positive bacteria is enhanced by toxins like the Streptococcus pyogenes β-NAD+ glycohydrolase known as SPN. SPN-producing strains of S. pyogenes additionally express the protein immunity factor for SPN (IFS), which forms an inhibitory complex with SPN. We have determined crystal structures of the SPN-IFS complex and IFS alone, revealing that SPN is structurally related to ADP-ribosyl transferases but lacks the canonical binding site for protein substrates. SPN is instead a highly efficient glycohydrolase with the potential to deplete cellular levels of β-NAD+. The protective effect of IFS involves an extensive interaction with the SPN active site that blocks access to β-NAD+. The conformation of IFS changes upon binding to SPN, with repacking of an extended C-terminal α-helix into a compact shape. IFS is an attractive target for the development of novel bacteriocidal compounds functioning by blocking the bacterium's self-immunity to the SPN toxin. PMID:21300288

  11. Detection of early gastric cancer facilitated by surveillance for a pyogenic liver abscess caused by Streptococcus intermedius.

    PubMed

    Shigefuku, Ryuta; Matsunaga, Kotaro; Tamura, Tomohiro; Ozawa, Shun-Ichiro; Matsuo, Yasumasa; Takahashi, Hideaki; Matsumoto, Nobuyuki; Okuse, Chiaki; Suzuki, Michihiro; Itoh, Fumio

    2016-01-01

    We report a case of early gastric cancer that was detected during surveillance of a pyogenic liver abscess caused by Streptococcus intermedius, an oral microbiota. Treatment with proton pump inhibitors can result in the alteration of gastric bacterial flora by altering intragastric acidity. This can place immunocompromised patients, such as those with diabetes mellitus and the elderly, at an increased risk for disease of the upper gastrointestinal tract to be a route of bacterial transmission. In this case, the patient developed a pyogenic liver abscess.

  12. 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

  13. 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

  14. 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

  15. 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

  16. Streptococcal 5'-Nucleotidase A (S5nA), a Novel Streptococcus pyogenes Virulence Factor That Facilitates Immune Evasion.

    PubMed

    Zheng, Lisa; Khemlani, Adrina; Lorenz, Natalie; Loh, Jacelyn M S; Langley, Ries J; Proft, Thomas

    2015-12-25

    Streptococcus pyogenes is an important human pathogen that causes a wide range of diseases. Using bioinformatics analysis of the complete S. pyogenes strain SF370 genome, we have identified a novel S. pyogenes virulence factor, which we termed streptococcal 5'-nucleotidase A (S5nA). A recombinant form of S5nA hydrolyzed AMP and ADP, but not ATP, to generate the immunomodulatory molecule adenosine. Michaelis-Menten kinetics revealed a Km of 169 μm and a Vmax of 7550 nmol/mg/min for the substrate AMP. Furthermore, recombinant S5nA acted synergistically with S. pyogenes nuclease A to generate macrophage-toxic deoxyadenosine from DNA. The enzyme showed optimal activity between pH 5 and pH 6.5 and between 37 and 47 °C. Like other 5'-nucleotidases, S5nA requires divalent cations and was active in the presence of Mg(2+), Ca(2+), or Mn(2+). However, Zn(2+) inhibited the enzymatic activity. Structural modeling combined with mutational analysis revealed a highly conserved catalytic dyad as well as conserved substrate and cation-binding sites. Recombinant S5nA significantly increased the survival of the non-pathogenic bacterium Lactococcus lactis during a human whole blood killing assay in a dose-dependent manner, suggesting a role as an S. pyogenes virulence factor. In conclusion, we have identified a novel S. pyogenes enzyme with 5'-nucleotidase activity and immune evasion properties.

  17. Functional and structural properties of a novel protein and virulence factor (Protein sHIP) in Streptococcus pyogenes.

    PubMed

    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

    2014-06-27

    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.

  18. 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

  19. Phage 3396 from a Streptococcus dysgalactiae subsp. equisimilis pathovar may have its origins in streptococcus pyogenes.

    PubMed

    Davies, Mark R; McMillan, David J; Van Domselaar, Gary H; Jones, Malcolm K; Sriprakash, Kadaba S

    2007-04-01

    Streptococcus dysgalactiae subsp. equisimilis strains (group G streptococcus [GGS]) are largely defined as commensal organisms, which are closely related to the well-defined human pathogen, the group A streptococcus (GAS). While lateral gene transfers are emerging as a common theme in these species, little is known about the mechanisms and role of these transfers and their effect on the population structure of streptococci in nature. It is now becoming evident that bacteriophages are major contributors to the genotypic diversity of GAS and, consequently, are pivotal to the GAS strain structure. Furthermore, bacteriophages are strongly associated with altering the pathogenic potential of GAS. In contrast, little is know about phages from GGS and their role in the population dynamics of GGS. In this study we report the first complete genome sequence of a GGS phage, Phi3396. Exhibiting high homology to the GAS phage Phi315.1, the chimeric nature of Phi3396 is unraveled to reveal evidence of extensive ongoing genetic diversity and dissemination of streptococcal phages in nature. Furthermore, we expand on our recent findings to identify inducible Phi3396 homologues in GAS from a region of endemicity for GAS and GGS infection. Together, these findings provide new insights into not only the population structure of GGS but also the overall population structure of the streptococcal genus and the emergence of pathogenic variants.

  20. 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.

  1. 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.

  2. PepO, a CovRS-controlled endopeptidase, disrupts Streptococcus pyogenes quorum sensing.

    PubMed

    Wilkening, Reid V; Chang, Jennifer C; Federle, Michael J

    2016-01-01

    Group A Streptococcus (GAS, Streptococcus pyogenes) is a human-restricted pathogen with a capacity to both colonize asymptomatically and cause illnesses ranging from pharyngitis to necrotizing fasciitis. An understanding of how and when GAS switches between genetic programs governing these different lifestyles has remained an enduring mystery and likely requires carefully tuned environmental sensors to activate and silence genetic schemes when appropriate. Herein, we describe the relationship between the Control of Virulence (CovRS, CsrRS) two-component system and the Rgg2/3 quorum-sensing pathway. We demonstrate that responses of CovRS to the stress signals Mg(2+) and a fragment of the antimicrobial peptide LL-37 result in modulated activity of pheromone signaling of the Rgg2/3 pathway through a means of proteolysis of SHP peptide pheromones. This degradation is mediated by the cytoplasmic endopeptidase PepO, which is the first identified enzymatic silencer of an RRNPP-type quorum-sensing pathway. These results suggest that under conditions in which the virulence potential of GAS is elevated (i.e. enhanced virulence gene expression), cellular responses mediated by the Rgg2/3 pathway are abrogated and allow individuals to escape from group behavior. These results also indicate that Rgg2/3 signaling is instead functional during non-virulent GAS lifestyles.

  3. 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

  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. 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

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

    PubMed

    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.

  7. 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

  8. An arm-swapped dimer of the Streptococcus pyogenes pilin specific assembly factor SipA.

    PubMed

    Young, Paul G; Kang, Hae Joo; Baker, Edward N

    2013-07-01

    Streptococcus pyogenes (group A streptococcus [GAS]) is a major human pathogen. Attachment of GAS to host cells depends in large part on pili. These assemblies are built from multiple covalently linked subunits of a backbone protein (FctA), which forms the shaft of the pilus, and two minor pilin proteins, FctB anchoring the pilus to the cell wall and Cpa functioning as the adhesin at the tip. Polymerisation of the pilin subunits is mediated by a specific sortase, which catalyzes the formation of peptide bonds linking successive subunits. An additional gene, SipA, is also essential for GAS pilus polymerisation, but its function remains undefined. Here we report the crystal structure of a truncated SipA protein from GAS, determined at 1.67Å resolution. The structure reveals that SipA has the same core fold as the Escherichia coli type-I signal peptidase (SPase-I), but has a much smaller non-catalytic domain. The truncated protein, which lacks 9 N-terminal residues, forms an arm-swapped dimer in which the C-terminal β-strand of each monomer crosses over to interact with an N-terminal strand from the other monomer. In addition, there is no peptide binding cleft and significant differences in the putative membrane association region. PMID:23747392

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

    PubMed

    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.

  10. 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

  11. Rapid Development of Brain Abscess Caused by Streptococcus Pyogenes Following Penetrating Skull Injury via the Ethmoidal Sinus and Lamina Cribrosa

    PubMed Central

    Aydin, Gerilmez; Cömert, Serhat; Altinors, Nur

    2010-01-01

    Objective Streptococcus pyogenes is a beta-hemolytic bacterium that belongs to Lancefield serogroup A, also known as group A streptococci (GAS). There have been five reported case in terms of PubMed-based search but no reported case of brain abscess caused by Streptococcus pyogenes as a result of penetrating skull injury. We present a patient who suffered from penetrating skull injury that resulted in a brain abscess caused by Streptococcus pyogenes. Methods The patient was a 12-year-old boy who fell down from his bicycle while cycling and ran into a tree. A wooden stick penetrated his skin below the right lower eyelid and advanced to the cranium. He lost consciousness on the fifth day of the incident and his body temperature was measured as 40℃. While being admitted to our hospital, a cranial computed tomography revealed a frontal cystic mass with a perilesional hypodense zone of edema. There was no capsule formation around the lesion after intravenous contrast injection. Paranasal CT showed a bone defect located between the ethmoidal sinus and lamina cribrosa. Results Bifrontal craniotomy was performed. The abscess located at the left frontal lobe was drained and the bone defect was repaired. Conclusion Any penetrating lesion showing a connection between the lamina cribrosa and ethmoidal sinus may result in brain abscess caused by Streptococcus pyogenes. These patients should be treated urgently to repair the defect and drain the abscess with appropriate antibiotic therapy started due to the fulminant course of the brain abscess caused by this microorganism. PMID:20717517

  12. 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.

  13. 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

  14. 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

  15. 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

  16. Molecular characterization of macrolide resistant Streptococcus pyogenes isolates from pharyngitis patients in Serbia.

    PubMed

    Opavski, Natasa; Gajic, Ina; Borek, Anna L; Obszańska, Katarzyna; Stanojevic, Maja; Lazarevic, Ivana; Ranin, Lazar; Sitkiewicz, Izabela; Mijac, Vera

    2015-07-01

    A steady increase in macrolide resistance in Streptococcus pyogenes, group A streptococci (GAS) was reported in Serbia during 2004-2009 (9.9%). However, there are no data on the molecular epidemiology of pharyngeal macrolide resistance GAS (MRGAS) isolates. Therefore, the aims of this first nationwide study were to examine the prevalence of macrolide resistance in Serbian GAS and to determine their resistance phenotypes, genotypes and clonal relationships. Overall 3893 non-duplicate pharyngeal S. pyogenes isolates from outpatients with GAS infection were collected throughout country during 2008 and 2009. Among 486 macrolide resistant pharyngeal isolates collected, 103 were further characterized. Macrolide resistance phenotypes and genotypes were determined by double-disk diffusion test and PCR, respectively. Strain relatedness was determined by emm typing, multilocus sequence typing (MLST), multilocus variable tandem repeat analysis (MLVA), phage profiling (PP) and virulence factor profiling (VFP). Overall, macrolide resistance among GAS isolates in Serbia was 12.5%. M phenotype was the most common (71.8%), followed by iMLS (18.4%) and cMLS (9.7%). Three clonal complexes--emm75/mefA/ST49, emm12/mefA/ST36 and emm77/ermA/tetO/ST63 comprised over 90% of the tested strains. Although MLVA, PP and VFP distinguished 10, 20 and 12 different patterns, respectively, cluster analysis disclosed only small differences between strains which belonged to the same emm/ST type. Our data indicate dominance of three major internationally widely disseminated macrolide resistant clones and a high genetic homogeneity among the Serbian MRGAS population. Continued surveillance of macrolide resistance and clonal composition in MRGAS in Serbia in future is necessary to determine stability of MRGAS clones and to guide therapy strategies.

  17. Analysis of Polymorphic Residues Reveals Distinct Enzymatic and Cytotoxic Activities of the Streptococcus pyogenes NAD+ Glycohydrolase*

    PubMed Central

    Chandrasekaran, Sukantha; Ghosh, Joydeep; Port, Gary C.; Koh, Eun-ik; Caparon, Michael G.

    2013-01-01

    The Streptococcus pyogenes NAD+ glycohydrolase (SPN) is secreted from the bacterial cell and translocated into the host cell cytosol where it contributes to cell death. Recent studies suggest that SPN is evolving and has diverged into NAD+ glycohydrolase-inactive variants that correlate with tissue tropism. However, the role of SPN in both cytotoxicity and niche selection are unknown. To gain insight into the forces driving the adaptation of SPN, a detailed comparison of representative glycohydrolase activity-proficient and -deficient variants was conducted. Of a total 454 amino acids, the activity-deficient variants differed at only nine highly conserved positions. Exchanging residues between variants revealed that no one single residue could account for the inability of the deficient variants to cleave the glycosidic bond of β-NAD+ into nicotinamide and ADP-ribose; rather, reciprocal changes at 3 specific residues were required to both abolish activity of the proficient version and restore full activity to the deficient variant. Changing any combination of 1 or 2 residues resulted in intermediate activity. However, a change to any 1 residue resulted in a significant decrease in enzyme efficiency. A similar pattern involving multiple residues was observed for comparison with a second highly conserved activity-deficient variant class. Remarkably, despite differences in glycohydrolase activity, all versions of SPN were equally cytotoxic to cultured epithelial cells. These data indicate that the glycohydrolase activity of SPN may not be the only contribution the toxin has to the pathogenesis of S. pyogenes and that both versions of SPN play an important role during infection. PMID:23689507

  18. Molecular characterization and phylogenetic distribution of the streptococcal superantigen gene (ssa) from Streptococcus pyogenes.

    PubMed Central

    Reda, K B; Kapur, V; Mollick, J A; Lamphear, J G; Musser, J M; Rich, R R

    1994-01-01

    A striking increase in the frequency and severity of invasive infections caused by Streptococcus pyogenes has occurred in recent years. Among these diseases is streptococcal toxic-shock-like syndrome (TSLS), a condition characterized by fulminant soft-tissue destruction and multiorgan failure. Streptococcal superantigen (SSA), a superantigen isolated from a TSLS-inducing, serotype M3 S. pyogenes strain, has recently been identified. We here describe the cloning, sequencing, and phylogenetic distribution of the SSA structural gene. The 783-bp open reading frame encodes a predicted 260-amino-acid protein that is similar in size to several other bacterial superantigens. The deduced sequence of the mature protein is 60.2% identical to that of staphylococcal enterotoxin B but only 49% identical to that of streptococcal pyrogenic exotoxin A. Southern blot and PCR analysis of 138 group A streptococcal strains representing 65 M protein serotypes and 15 nontypeable isolates identified ssa in 68 strains from 10 distinct clonal lineages. All ssa-positive clones expressed SSA. Of the two clones associated with TSLS, the ET 2-M3 lineage, but not the ET 1-M1 lineage, carried the SSA gene. Further analysis of the ET 2-M3 lineage found evidence for temporal variation in ssa association. Contemporary ET 2-M3 disease isolates had ssa, but two older isolates of this clone recovered in 1910 and 1920 lacked the gene. The clonal and temporal distribution patterns of ssa suggest a relatively recent acquisition of this superantigen-encoding gene by the ET 2-M3 lineage, perhaps by horizontal transfer and recombination. Images PMID:8168951

  19. 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

  20. An oxygen-induced but protein F-independent fibronectin-binding pathway in Streptococcus pyogenes.

    PubMed Central

    Lee, J Y; Caparon, M

    1996-01-01

    Protein F is an important fibronectin-binding adhesin of Streptococcus pyogenes (group A streptococcus). However, all previous analyses of protein F have been conducted in a mutant strain which expresses protein F under anaerobic conditions nonpermissive for expression in other strains. In this study, we have examined the fibronectin-binding properties of several protein F-deficient mutants cultured under aerobic conditions and have identified a second pathway for binding fibronectin. Unlike the case with protein F, exposure to an aerobic environment does not induce transcription of a new gene product. Rather, O2 is apparently required for the modification of a protease-resistant cell surface component into a binding-component form. Modification occurred preferentially at a pH of 6.0 or less, and the binding of the modified component to fibronectin required Zn2+. The oxidizing agent Fe(CN)6 could be substituted for O2 and stimulated expression of binding activity under O2-limiting conditions. Streptococcal fibronectin binding mediated by this pathway but not by protein F could be inhibited by laminin and by streptococcal lipoteichoic acid, a molecule previously implicated as the streptococcal adhesin for fibronectin. The non-protein F-binding activity could also substantially enhance the binding of the organism for fibronectin. The non-protein F-binding activity could also substantially enhance the binding of the organism to basement membrane. By using differential inhibition, analyses of binding to non-protein F mutant strains demonstrated that the total level of fibronectin bound under aerobic conditions reflects contributions from both pathways. Because of its dependence on Zn2+, an oxidant, and pH, this binding activity has been designated the ZOP binding pathway. PMID:8550185

  1. Resistance to Macrolides in Streptococcus pyogenes in France in Pediatric Patients

    PubMed Central

    Bingen, Edouard; Fitoussi, Frederic; Doit, Catherine; Cohen, Robert; Tanna, Asha; George, Robert; Loukil, Chawki; Brahimi, Naima; Le Thomas, Isabelle; Deforche, Dominique

    2000-01-01

    A total of 1,500 recent throat isolates of Streptococcus pyogenes collected between 1996 and 1999 from children throughout France were tested for their susceptibility to erythromycin, azithromycin, josamycin, clindamycin, and streptogramin B. The erythromycin-resistant isolates were further studied for their genetic mechanism of resistance, by means of PCR. The clonality of these strains was also investigated by means of serotyping and ribotyping. In all, 6.2% of the strains were erythromycin resistant, and 3.4 and 2.8% expressed the constitutive MLSB and M resistance phenotypes and harbored the ermB and mefA genes, respectively; ermTR was recovered from one isolate which also harbored the ermB gene. Ten serotypes and 8 ribotypes were identified, but we identified 17 strains by combining serotyping with ribotyping. Among the eight ribotypes, the mefA gene was recovered from six clusters, one being predominant, while the ermB gene was recovered from four clusters, of which two were predominant. PMID:10817692

  2. 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.

  3. Structural model for covalent adhesion of the Streptococcus pyogenes pilus through a thioester bond.

    PubMed

    Linke-Winnebeck, Christian; Paterson, Neil G; Young, Paul G; Middleditch, Martin J; Greenwood, David R; Witte, Gregor; Baker, Edward N

    2014-01-01

    The human pathogen Streptococcus pyogenes produces pili that are essential for adhesion to host surface receptors. Cpa, the adhesin at the pilus tip, was recently shown to have a thioester-containing domain. The thioester bond is believed to be important in adhesion, implying a mechanism of covalent attachment analogous to that used by human complement factors. Here, we have characterized a second active thioester-containing domain on Cpa, the N-terminal domain of Cpa (CpaN). Expression of CpaN in Escherichia coli gave covalently linked dimers. These were shown by x-ray crystallography and mass spectrometry to comprise two CpaN molecules cross-linked by the polyamine spermidine following reaction with the thioester bonds. This cross-linked CpaN dimer provides a model for the covalent attachment of Cpa to target receptors and thus the streptococcal pilus to host cells. Similar thioester domains were identified in cell wall proteins of other Gram-positive pathogens, suggesting that thioester domains are more widely used and provide a mechanism of adhesion by covalent bonding to target molecules on host cells that mimics that used by the human complement system to eliminate pathogens.

  4. 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

  5. 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

  6. Crystallization and preliminary X-ray crystallographic studies of succinic semialdehyde dehydrogenase from Streptococcus pyogenes

    PubMed Central

    Jang, Eun Hyuk; Lim, Jong Eun; Chi, Young Min; Lee, Ki Seog

    2012-01-01

    Succinic semialdehyde dehydrogenase (SSADH) plays a critical role in the metabolism of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) and catalyzes the NAD(P)+-coupled oxidation of succinic semialdehyde (SSA) to succinic acid (SA). SSADH from Streptococcus pyogenes has been purified and crystallized as the apoenzyme and in a complex with NAD+. The crystals of native and NAD+-complexed SSADH diffracted to resolutions of 1.6 and 1.7 Å, respectively, using a synchrotron-radiation source. Both crystals belonged to the orthorhombic space group P21212­1, with unit-cell parameters a = 93.3, b = 100.3, c = 105.1 Å for the native crystal and a = 93.3, b = 100.3, c = 105.0 Å for the complex crystal. Preliminary molecular replacement confirmed the presence of one dimer in both crystals, corresponding to a Matthews coefficient (V M) of 2.37 Å3 Da−1 and a solvent content of 48.0%. PMID:22442224

  7. 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

  8. Presence of a Prophage Determines Temperature-Dependent Capsule Production in Streptococcus pyogenes

    PubMed Central

    Brown, Leslie; Kim, Jeong-Ho; Cho, Kyu Hong

    2016-01-01

    A hyaluronic acid capsule is a major virulence factor in the pathogenesis of Streptococcus pyogenes. It acts as an anti-phagocytic agent and adhesin to keratinocytes. The expression of the capsule is primarily regulated at the transcriptional level by the two-component regulatory system CovRS, in which CovR acts as a transcriptional repressor. The covRS genes are frequently mutated in many invasive strains, and a subset of the invasive CovRS mutants does not produce a detectable level of the capsule at 37 °C, but produces a significant amount of the capsule at sub-body temperatures. Here, we report that a prophage has a crucial role in this capsule thermoregulation. Passaging CovR-null strains showing capsule thermoregulation using a lab medium produced spontaneous mutants producing a significant amount of the capsule regardless of incubation temperature and this phenotypic change was caused by curing of a particular prophage. The lab strain HSC5 contains three prophages on the chromosome, and only ΦHSC5.3 was cured in all spontaneous mutants. This result indicates that the prophage ΦHSC5.3 plays a crucial role in capsule thermoregulation, most likely by repressing capsule production at 37 °C. PMID:27669311

  9. 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

  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. Presence of a Prophage Determines Temperature-Dependent Capsule Production in Streptococcus pyogenes.

    PubMed

    Brown, Leslie; Kim, Jeong-Ho; Cho, Kyu Hong

    2016-01-01

    A hyaluronic acid capsule is a major virulence factor in the pathogenesis of Streptococcus pyogenes. It acts as an anti-phagocytic agent and adhesin to keratinocytes. The expression of the capsule is primarily regulated at the transcriptional level by the two-component regulatory system CovRS, in which CovR acts as a transcriptional repressor. The covRS genes are frequently mutated in many invasive strains, and a subset of the invasive CovRS mutants does not produce a detectable level of the capsule at 37 °C, but produces a significant amount of the capsule at sub-body temperatures. Here, we report that a prophage has a crucial role in this capsule thermoregulation. Passaging CovR-null strains showing capsule thermoregulation using a lab medium produced spontaneous mutants producing a significant amount of the capsule regardless of incubation temperature and this phenotypic change was caused by curing of a particular prophage. The lab strain HSC5 contains three prophages on the chromosome, and only ΦHSC5.3 was cured in all spontaneous mutants. This result indicates that the prophage ΦHSC5.3 plays a crucial role in capsule thermoregulation, most likely by repressing capsule production at 37 °C. PMID:27669311

  12. Mercury(II) and methyl mercury speciation on Streptococcus pyogenes loaded Dowex Optipore SD-2.

    PubMed

    Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Karaman, Isa; Soylak, Mustafa

    2009-09-30

    A solid phase extraction procedure based on speciation of mercury(II) and methyl mercury on Streptococcus pyogenes immobilized on Dowex Optipore SD-2 has been established. Selective and sequential elution with 0.1 mol L(-1) HCl for methyl mercury and 2 mol L(-1) HCl for mercury(II) were performed at pH 8. The determination of mercury levels was performed by cold vapour atomic absorption spectrometry (CVAAS). Optimal analytical conditions including pH, amounts of biosorbent, sample volumes, etc., were investigated. The influences of the some alkaline and earth alkaline ions and some transition metals on the recoveries were also investigated. The capacity of biosorbent for mercury(II) and methyl mercury was 4.8 and 3.4 mg g(-1). The detection limit (3 sigma) of the reagent blank for mercury(II) and methyl mercury was 2.1 and 1.5 ng L(-1). Preconcentration factor was calculated as 25. The relative standard deviations of the procedure were below 7%. The validation of the presented procedure is performed by the analysis of standard reference material (NRCC-DORM 2 Dogfish Muscle). The procedure was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and environmental samples.

  13. 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.

  14. Analysis of the roles of NrdR and DnaB from Streptococcus pyogenes in response to host defense.

    PubMed

    Zhang, Yan; Okada, Ryo; Isaka, Masanori; Tatsuno, Ichiro; Isobe, Ken-Ichi; Hasegawa, Tadao

    2015-03-01

    Toxic shock syndrome caused by Streptococcus pyogenes (S. pyogenes) is a re-emerging infectious disease. Many virulence-associated proteins play important roles in its pathogenesis and the production of these proteins is controlled by many regulatory factors. CovS is one of the most important two-component sensor proteins in S. pyogenes, and it has been analyzed extensively. Our recent analyses revealed the existence of a transposon between covS and nrdR in several strains, and we speculated that this insertion has some importance. Hence, we examined the significances of the NrdR stand-alone regulator and DnaB, which is encoded by the gene located immediately downstream of nrdR in S. pyogenes infection. We established an nrdR-only knockout strain, and both nrdR and partial dnaB knockout strain. These established knockout strains exhibited a deteriorated response to H2 O2 exposure. nrdR and partial dnaB knockout strain was more easily killed by human polynuclear blood cells, but the nrdR-only knockout strain had no significant difference compared to wild type in contrast to the combined knockout strain. In addition, the mouse infection model experiment illustrated that nrdR and partial dnaB knockout strain, but not the nrdR-only knockout strain, was less virulent compared with the parental strain. These results suggest that DnaB is involved in response to host defense.

  15. Increased blood levels of IgG reactive with secreted Streptococcus pyogenes proteins in chronic plaque psoriasis.

    PubMed

    El-Rachkidy, Rana G; Hales, Jonathan M; Freestone, Primrose P E; Young, Helen S; Griffiths, Christopher E M; Camp, Richard D R

    2007-06-01

    A pathogenic role for Streptococcus (S) pyogenes infections in chronic plaque psoriasis is suspected but poorly defined. We separated cellular and supernatant proteins from S. pyogenes cultures by high-resolution two-dimensional gel electrophoresis, and used immunoblotting to demonstrate the diversity of serum or plasma IgGs that react with elements of the proteome of this bacterium. We have shown that a substantial proportion of IgG-reactive proteins from cultured S. pyogenes are secreted. The total secreted protein fraction, including diverse IgG-binding elements, was subsequently used in an ELISA to measure blood titers of reactive IgG. This ELISA showed that blood samples from patients with chronic plaque psoriasis contained significantly higher titers of reactive IgG than samples from age- and sex-matched healthy controls (P=0.0009). In contrast, neither a standard assay measuring antistreptolysin O titers nor ELISAs measuring titers of IgG reactive with protein fractions from Staphylococcus aureus and Staphylococcus epidermidis, were able to distinguish between blood samples from the two groups. These findings justify the hypothesis that S. pyogenes infections are more important in the pathogenesis of chronic plaque psoriasis than has previously been recognized, and indicate the need for further controlled therapeutic trials of antibacterial measures in this common skin disease.

  16. 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

  17. 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

  18. Tn5253 family integrative and conjugative elements carrying mef(I) and catQ determinants in Streptococcus pneumoniae and Streptococcus pyogenes.

    PubMed

    Mingoia, Marina; Morici, Eleonora; Morroni, Gianluca; Giovanetti, Eleonora; Del Grosso, Maria; Pantosti, Annalisa; Varaldo, Pietro E

    2014-10-01

    The linkage between the macrolide efflux gene mef(I) and the chloramphenicol inactivation gene catQ was first described in Streptococcus pneumoniae (strain Spn529), where the two genes are located in a module designated IQ element. Subsequently, two different defective IQ elements were detected in Streptococcus pyogenes (strains Spy029 and Spy005). The genetic elements carrying the three IQ elements were characterized, and all were found to be Tn5253 family integrative and conjugative elements (ICEs). The ICE from S. pneumoniae (ICESpn529IQ) was sequenced, whereas the ICEs from S. pyogenes (ICESpy029IQ and ICESpy005IQ, the first Tn5253-like ICEs reported in this species) were characterized by PCR mapping, partial sequencing, and restriction analysis. ICESpn529IQ and ICESpy029IQ were found to share the intSp 23FST81 integrase gene and an identical Tn916 fragment, whereas ICESpy005IQ has int5252 and lacks Tn916. All three ICEs were found to lack the linearized pC194 plasmid that is usually associated with Tn5253-like ICEs, and all displayed a single copy of a toxin-antitoxin operon that is typically contained in the direct repeats flanking the excisable pC194 region when this region is present. Two different insertion sites of the IQ elements were detected, one in ICESpn529IQ and ICESpy029IQ, and another in ICESpy005IQ. The chromosomal integration of the three ICEs was site specific, depending on the integrase (intSp 23FST81 or int5252). Only ICESpy005IQ was excised in circular form and transferred by conjugation. By transformation, mef(I) and catQ were cotransferred at a high frequency from S. pyogenes Spy005 and at very low frequencies from S. pneumoniae Spn529 and S. pyogenes Spy029.

  19. Bacterial Superantigens Promote Acute Nasopharyngeal Infection by Streptococcus pyogenes in a Human MHC Class II-Dependent Manner

    PubMed Central

    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.

    2014-01-01

    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

  20. 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

  1. 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.

  2. 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.

  3. Defective synthesis of lipid intermediates for peptidoglycan formation in a stabilized L-form of Streptococcus pyogenes.

    PubMed Central

    Reusch, V M; Panos, C

    1976-01-01

    Membrane preparations obtained from a stabilized L-form of Streptococcus pyogenes are incapable of synthesizing peptidoglycan from uridine-5'-diphospho-N-acetyl-D-muramyl-L-Ala-D-iso-Glu-L-Lys-D-Ala-D-Ala and uridine-5'-diphospho-N-acetyl-D-glucosamine, in contrast with similar preparations from the parental streptococcus. Furthermore, 50-fold higher levels of lipid intermediates which serve as membrane-bound substrates for peptidoglycan synthesis are synthesized in reaction mixtures containing streptococcal membranes than with similar preparations from the L-form. These observations suggest that the inability of this stabilized L-form to form a cell wall in vivo lies, at least in part, in its failure to synthesize significant quantities of the lipid substrates for peptidoglycan synthesis. PMID:4426

  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. 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

  6. Structure and activity of Streptococcus pyogenes SipA: a signal peptidase-like protein essential for pilus polymerisation.

    PubMed

    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.

  7. 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

  8. 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

  9. Vaccination with Streptococcus pyogenes nuclease A stimulates a high antibody response but no protective immunity in a mouse model of infection.

    PubMed

    Radcliff, Fiona J; Fraser, John D; Proft, Thomas

    2015-04-01

    Streptococcus pyogenes is a human pathogen which causes a spectrum of diseases ranging from pharyngitis to rheumatic fever, necrotising fasciitis and toxic shock syndrome. Development of a vaccine for S. pyogenes has been confounded both by the diversity of the disease-causing serotypes and the spectre of inadvertently stimulating autoimmunity. The S. pyogenes nuclease A (SpnA) is a recently characterised virulence factor that is highly conserved across strains and expressed during human disease. Deletion of spnA from S. pyogenes results in reduced survival of bacteria in whole human blood and attenuated virulence in a mouse model of infection. Collectively these features suggest that SpnA has potential as a vaccine candidate for S. pyogenes. Mice vaccinated subcutaneously with single or multiple doses of recombinant SpnA emulsified in Incomplete Freund's Adjuvant developed a robust and durable IgG response, including neutralising activity, to this protein. However, vaccination with rSpnA conferred no advantage in terms of lesion development, disease symptoms or colonisation levels after a sub-lethal subcutaneous challenge with S. pyogenes. Anti-SpnA serum IgG responses and neutralising activity were increased in response to challenge, indicating that SpnA is expressed in vivo. SpnA is unlikely to be a suitable antigen for a vaccine against S. pyogenes.

  10. A NEW SELECTIVE BLOOD AGAR MEDIUM FOR STREPTOCOCCUS PYOGENES AND OTHER HAEMOLYTIC STREPTOCOCCI.

    PubMed

    LOWBURY, E J; KIDSON, A; LILLY, H A

    1964-05-01

    Horse blood agar containing polymyxin B sulphate, neomycin sulphate, and fusidic acid inhibited the growth of Staph. aureus, Ps. pyocyanea, Proteus mirabilis, E. coli, and Klebsiella pneumoniae but allowed good growth of, and haemolysis by, Str. pyogenes. In a comparison with blood agar, blood 4% agar, and gentian violet blood agar, the selective medium (P.N.F.) yielded a significantly higher proportion of streptococci than the other media, both by aerobic and by anaerobic culture, from burn swab extracts deliberately contaminated with Str. pyogenes; P.N.F. culture was more effective with dilute than with heavy inocula of Str. pyogenes, allowing from three to seven times as many recoveries of Str. pyogenes from swabs contaminated with 10(-3) dilution of streptococcal cultures than cultures of the same material on the other media. Haemolytic streptococci of groups A, C, D, G, and others were isolated by aerobic culture from burns in a consecutive series of 1,277 swabs more often on P.N.F. medium than on blood 4% agar. Viable counts of 12 strains (including 11 different serological types) of Str. pyogenes showed some reduction in the numbers of colonies compared with counts on blood agar, and some strains grew more slowly on P.N.F. medium. These limitations, however, were offset and outweighed by the higher final yield of streptococci on the selective medium.

  11. 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

  12. Crystal structures of Streptococcus pyogenes Dpr reveal a dodecameric iron-binding protein with a ferroxidase site.

    PubMed

    Haikarainen, Teemu; Tsou, Chih-Cheng; Wu, Jiunn-Jong; Papageorgiou, Anastassios C

    2010-02-01

    DNA-binding protein from starved cells (Dps)-like proteins are key factors involved in oxidative stress protection in bacteria. They bind and oxidize iron, thus preventing the formation of harmful reactive oxygen species that can damage biomolecules, particularly DNA. Dps-like proteins are composed of 12 identical subunits assembled in a spherical structure with a hollow central cavity. The iron oxidation occurs at 12 intersubunit sites located at dimer interfaces. Streptococcus pyogenes Dps-like peroxide resistance protein (Dpr) has been previously found to protect the catalase-lacking S. pyogenes bacterium from oxidative stress. We have determined the crystal structure of S. pyogenes Dpr, the second Dpr structure from a streptococcal bacterium, in iron-free and iron-bound forms at 2.0- and 1.93-A resolution, respectively. The iron binds to well-conserved sites at dimer interfaces and is coordinated directly to Asp77 and Glu81 from one monomer, His50 from a twofold symmetry-related monomer, a glycerol molecule, and a water molecule. Upon iron binding, Asp77 and Glu81 change conformation. Site-directed mutagenesis of active-site residues His50, His62, Asp66, Asp77, and Glu81 to Ala revealed a dramatic decrease in iron incorporation. A short helix at the N-terminal was found in a different position compared with other Dps-like proteins. Two types of pores were identified in the dodecamer. Although the N-terminal pore was found to be similar to that of other Dps-like proteins, the C-terminal pore was found to be blocked by bulky Tyr residues instead of small residues present in other Dps-like proteins. PMID:19727858

  13. 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

  14. Epidemiology and molecular characterization of Streptococcus pyogenes recovered from scarlet fever patients in central Taiwan from 1996 to 1999.

    PubMed

    Chiou, Chien-Shun; Liao, Tsai-Ling; Wang, Tzu-Hui; Chang, Hsiu-Li; Liao, Jui-Cheng; Li, Chun-Chin

    2004-09-01

    One hundred seventy-nine Streptococcus pyogenes isolates recovered from scarlet fever patients from 1996 to 1999 in central Taiwan were characterized by emm, Vir, and pulsed-field gel electrophoresis (PFGE) typing methods. The protocols for Vir and PFGE typing were standardized. A database of the DNA fingerprints for the isolates was established. Nine emm or emm-like genes, 19 Vir patterns, and 26 SmaI PFGE patterns were detected among the isolates. Among the three typing methods, PFGE was the most discriminatory. However, it could not completely replace Vir typing because some isolates with identical PFGE patterns could be further differentiated into several Vir patterns. The prevalent emm types were emm4 (n = 81 isolates [45%]), emm12 (n = 64 [36%]), emm1 (n = 14 [8%]), and emm22 (n = 13 [7%]). Some emm type isolates could be further differentiated into several emm-Vir-PFGE genotypes; however, only one genotype in each emm group was usually predominant. DNA from nine isolates was resistant to SmaI digestion. Further PFGE analysis with SgrAI showed that the SmaI digestion-resistant strains could be derived from indigenous strains by horizontal transfer of exogenous genetic material. The emergence of the new strains could have resulted in an increase in scarlet fever cases in central Taiwan since 2000. The emm sequences, Vir, and PFGE pattern database will serve as a basis for information for the long-term evolutionary study of local S. pyogenes strains.

  15. 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%.

  16. Correlation between genetic features of the mef(A)-msr(D) locus and erythromycin resistance in Streptococcus pyogenes.

    PubMed

    Vitali, Luca Agostino; Di Luca, Maria Chiara; Prenna, Manuela; Petrelli, Dezemona

    2016-01-01

    We investigated the correlation between the genetic variation within mef(A)-msr(D) determinants of efflux-mediated erythromycin resistance in Streptococcus pyogenes and the level of erythromycin resistance. Twenty-eight mef(A)-positive strains were selected according to erythromycin MIC (4-32 μg/mL), and their mef(A)-msr(D) regions were sequenced. Strains were classified according to the bacteriophage carrying mef(A)-msr(D). A new Φm46.1 genetic variant was found in 8 strains out of 28 and named VP_00501.1. Degree of allelic variation was higher in mef(A) than in msr(D). Hotspots for recombination were mapped within the locus that could have shaped the apparent mosaic structure of the region. There was a general correlation between mef(A)-msr(D) sequence and erythromycin resistance level. However, lysogenic conversion of susceptible strains by mef(A)-msr(D)-carrying Φm46.1 indicated that key determinants may not all reside within the mef(A)-msr(D) locus and that horizontal gene transfer could contribute to changes in the level of antibiotic resistance in S. pyogenes.

  17. The in vitro antibacterial activity of ceftriaxone against Streptococcus pyogenes is unrelated to penicillin-binding protein 4.

    PubMed

    Yan, S; Mendelman, P M; Stevens, D L

    1993-07-01

    The in vitro activities of penicillin and ceftriaxone were compared against 29 strains of Streptococcus pyogenes with the result that ceftriaxone showed greater activity than penicillin. The morphological changes induced by 1/2 and 1x MIC concentrations of penicillin and ceftriaxone, respectively, were very similar using scanning electron microscopy. Competitive binding studies using 'cold' penicillin or ceftriaxone as inhibitors of radiolabeled penicillin binding demonstrated that ceftriaxone had a very low affinity for penicillin binding protein (PBP) 4 compared to that of penicillin. Since ceftriaxone had greater antibacterial activity, this suggests that PBP 4 may not be important to the in vitro activity of ceftriaxone. In contrast, the IC50 for ceftriaxone was much lower (> 200 fold) for PBPs 2 and 3 compared to PBP 4, suggesting greater avidity of these high molecular mass PBPs for ceftriaxone. These data may at least in part explain the superior in vitro activity of ceftriaxone compared to penicillin against S. pyogenes. These data, together with the observation that PBP 1 was saturated at a lower concentration of penicillin than any of the other PBPs, suggest that the inhibition of PBPs 1, 2, and 3 mediates the bactericidal activity of beta-lactam antibiotics against group A streptococci. PMID:8354465

  18. 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

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

    PubMed Central

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

    1997-01-01

    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

  20. 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.

  1. 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

  2. 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

  3. [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

  4. [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

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

    PubMed

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

    2016-01-01

    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.

  6. 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.

  7. Virulence factor regulation and regulatory networks in Streptococcus pyogenes and their impact on pathogen-host interactions.

    PubMed

    Kreikemeyer, Bernd; McIver, Kevin S; Podbielski, Andreas

    2003-05-01

    Streptococcus pyogenes (group A streptococcus, GAS) is a very important human pathogen with remarkable adaptation capabilities. Survival within the harsh host surroundings requires sensing potential on the bacterial side, which leads in particular to coordinately regulated virulence factor expression. GAS 'stand-alone' response regulators (RRs) and two-component signal transduction systems (TCSs) link the signals from the host environment with adaptive responses of the bacterial cell. Numerous putative regulatory systems emerged from GAS genome sequences. Only three RRs [Mga, RofA-like protein (RALP) and Rgg/RopB] and three TCSs (CsrRS/CovRS, FasBCAX and Ihk/Irr) have been studied in some detail with respect to their growth-phase-dependent activity and their influence on GAS-host cell interaction. In particular, the Mga-, RALP- and Rgg/RopB-regulated pathways display interconnected activities that appear to influence GAS colonization, persistence and spreading mechanisms, in a growth-phase-related fashion. Here, we have summarized our current knowledge about these RRs and TCSs to highlight the questions that should be addressed in future research on GAS pathogenicity.

  8. 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

  9. Structural Conservation, Variability, and Immunogenicity of the T6 Backbone Pilin of Serotype M6 Streptococcus pyogenes

    PubMed Central

    Moreland, Nicole J.; Loh, Jacelyn M.; Bell, Anita; Atatoa Carr, Polly; Proft, Thomas; Baker, Edward N.

    2014-01-01

    Group A streptococcus (GAS; Streptococcus pyogenes) is a Gram-positive human pathogen that causes a broad range of diseases ranging from acute pharyngitis to the poststreptococcal sequelae of acute rheumatic fever. GAS pili are highly diverse, long protein polymers that extend from the cell surface. They have multiple roles in infection and are promising candidates for vaccine development. This study describes the structure of the T6 backbone pilin (BP; Lancefield T-antigen) from the important M6 serotype. The structure reveals a modular arrangement of three tandem immunoglobulin-like domains, two with internal isopeptide bonds. The T6 pilin lysine, essential for polymerization, is located in a novel VAKS motif that is structurally homologous to the canonical YPKN pilin lysine in other three- and four-domain Gram-positive pilins. The T6 structure also highlights a conserved pilin core whose surface is decorated with highly variable loops and extensions. Comparison to other Gram-positive BPs shows that many of the largest variable extensions are found in conserved locations. Studies with sera from patients diagnosed with GAS-associated acute rheumatic fever showed that each of the three T6 domains, and the largest of the variable extensions (V8), are targeted by IgG during infection in vivo. Although the GAS BP show large variations in size and sequence, the modular nature of the pilus proteins revealed by the T6 structure may aid the future design of a pilus-based vaccine. PMID:24778112

  10. SpyB, a Small Heme-Binding Protein, Affects the Composition of the Cell Wall in Streptococcus pyogenes

    PubMed Central

    Edgar, Rebecca J.; Chen, Jing; Kant, Sashi; Rechkina, Elena; Rush, Jeffrey S.; Forsberg, Lennart S.; Jaehrig, Bernhard; Azadi, Parastoo; Tchesnokova, Veronika; Sokurenko, Evgeni V.; Zhu, Haining; Korotkov, Konstantin V.; Pancholi, Vijay; Korotkova, Natalia

    2016-01-01

    Streptococcus pyogenes (Group A Streptococcus or GAS) is a hemolytic human pathogen associated with a wide variety of infections ranging from minor skin and throat infections to life-threatening invasive diseases. The cell wall of GAS consists of peptidoglycan sacculus decorated with a carbohydrate comprising a polyrhamnose backbone with immunodominant N-acetylglucosamine side-chains. All GAS genomes contain the spyBA operon, which encodes a 35-amino-acid membrane protein SpyB, and a membrane-bound C3-like ADP-ribosyltransferase SpyA. In this study, we addressed the function of SpyB in GAS. Phenotypic analysis of a spyB deletion mutant revealed increased bacterial aggregation, and reduced sensitivity to β-lactams of the cephalosporin class and peptidoglycan hydrolase PlyC. Glycosyl composition analysis of cell wall isolated from the spyB mutant suggested an altered carbohydrate structure compared with the wild-type strain. Furthermore, we found that SpyB associates with heme and protoporphyrin IX. Heme binding induces SpyB dimerization, which involves disulfide bond formation between the subunits. Thus, our data suggest the possibility that SpyB activity is regulated by heme. PMID:27790410

  11. 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.

  12. 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

  13. Complete Genome Sequence of Streptococcus pyogenes M/emm44 Strain STAB901, Isolated in a Clonal Outbreak in French Brittany.

    PubMed

    Soriano, Nicolas; Vincent, Pascal; Piau, Caroline; Moullec, Séverine; Gautier, Philippe; Lagente, Vincent; Faili, Ahmad; Kayal, Samer

    2014-11-20

    We report the complete genome sequence of an invasive isolate of Streptococcus pyogenes M/emm44, belonging to a clonal outbreak that occurred in French Brittany. The genome is composed of 1,795,608 bp, with a GC content of 38.5%, has 1,358 identified coding sequences (CDSs), and harbors a novel Tn916-like transposon (Tn6253).

  14. Complete Genome Sequence of Noninvasive Streptococcus pyogenes M/emm28 Strain STAB10015, Isolated from a Child with Perianal Dermatitis in French Brittany.

    PubMed

    de Andrade Barboza, Suzane; Meygret, Alexandra; Vincent, Pascal; Moullec, Séverine; Soriano, Nicolas; Lagente, Vincent; Minet, Jacques; Kayal, Samer; Faili, Ahmad

    2015-07-16

    We report here the complete genome sequence of a noninvasive strain of Streptococcus pyogenes M/emm28, isolated from perianal dermatitis in a child. The genome is composed of 1,950,454 bp, with a G+C content of 38.2%, and it has 1,925 identified coding sequences and harbors two intact prophages and a new integrating conjugative element (ICE).

  15. Full-Length Genome Sequence of Type M/emm83 Group A Streptococcus pyogenes Strain STAB1101, Isolated from Clustered Cases in Brittany.

    PubMed

    Soriano, Nicolas; Vincent, Pascal; Auger, Gabriel; Cariou, Marie-Estelle; Moullec, Séverine; Lagente, Vincent; Ygout, Jean-François; Kayal, Samer; Faili, Ahmad

    2015-01-22

    Here, we announce the complete annotated genome sequence of a Streptococcus pyogenes M/emm83 strain, STAB1101, isolated from clustered cases in homeless persons in Brittany (France). The genome is composed of 1,709,790 bp, with a G+C content of 38.4% and 1,550 identified coding sequences (CDS), and it harbors a Tn916-like transposon.

  16. Lactobacillus plantarum reduces Streptococcus pyogenes virulence by modulating the IL-17, IL-23 and Toll-like receptor 2/4 expressions in human epithelial cells.

    PubMed

    Rizzo, Antonietta; Losacco, Antonio; Carratelli, Caterina Romano; Domenico, Marina Di; Bevilacqua, Nazario

    2013-10-01

    Streptococcus pyogenes is a common colonizer of the mucosal layers in the mouth, nose, and pharynx but it is also a major Gram-positive human pathogen that causes infections ranging from pharyngitis to severe systemic diseases. The lactobacilli colonize the oral tracts and are known to protect against colonization by many pathogens. Epithelial cells participate in the innate host defense by expressing a variety of proinflammatory cytokines and TLRs in the interaction with microorganisms. The potentially probiotic strain Lactobacillus plantarum was investigated for its capacity to influence the innate immune response of HEp-2 and A549 epithelial cells to S. pyogenes infection. In both epithelial cell types, pre-treatment with L. plantarum showed inhibition of S. pyogenes growth and a greater decrease in IL-17 and IL-23 levels compared to the control. Pre-treatment with the anti-TLR2/4 antibody abolished the inhibitory effects of L. plantarum on IL-17 and IL-23 production following S. pyogenes infection, indicating that L. plantarum downregulates TLR2/4-dependent IL-17 and IL-23 production. Overall, our findings suggest that in epithelial cell cultures with S. pyogenes, cytokine responses are modulated by the presence of L. plantarum through the induction of TLR2/TLR4.

  17. 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

  18. Multiple length peptide-pheromone variants produced by Streptococcus pyogenes directly bind Rgg proteins to confer transcriptional regulation.

    PubMed

    Aggarwal, Chaitanya; Jimenez, Juan Cristobal; Nanavati, Dhaval; Federle, Michael J

    2014-08-01

    Streptococcus pyogenes, a human-restricted pathogen, accounts for substantial mortality related to infections worldwide. Recent studies indicate that streptococci produce and respond to several secreted peptide signaling molecules (pheromones), including those known as short hydrophobic peptides (SHPs), to regulate gene expression by a quorum-sensing mechanism. Upon transport into the bacterial cell, pheromones bind to and modulate activity of receptor proteins belonging to the Rgg family of transcription factors. Previously, we reported biofilm regulation by the Rgg2/3 quorum-sensing circuit in S. pyogenes. The aim of this study was to identify the composition of mature pheromones from cell-free culture supernatants that facilitate biofilm formation. Bioluminescent reporters were employed to detect active pheromones in culture supernatants fractionated by reverse-phase chromatography, and mass spectrometry was used to characterize their properties. Surprisingly, multiple SHPs that varied by length were detected. Synthetic peptides of each variant were tested individually using bioluminescence reporters and biofilm growth assays, and although activities differed widely among the group, peptides comprising the C-terminal eight amino acids of the full-length native peptide were most active. Direct Rgg/SHP interactions were determined using a fluorescence polarization assay that utilized FITC-labeled peptide ligands. Peptide receptor affinities were seen to be as low as 500 nm and their binding affinities directly correlated with observed bioactivity. Revelation of naturally produced pheromones along with determination of their affinity for cognate receptors are important steps forward in designing compounds whose purpose is positioned for future therapeutics aimed at treating infections through the interference of bacterial communication.

  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. 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

  1. Emergence of Streptococcus pyogenes emm102 Causing Toxic Shock Syndrome in Southern Taiwan during 2005–2012

    PubMed Central

    Lin, Jiun-Nong; Chang, Lin-Li; Lai, Chung-Hsu; Lin, Hsi-Hsun; Chen, Yen-Hsu

    2013-01-01

    Background Streptococcal toxic shock syndrome (STSS) is an uncommon but life-threatening disease caused by Streptococcus pyogenes. Methods To understand the clinical and molecular characteristics of STSS, we analyzed clinical data and explored the emm types, superantigen genes, and pulsed-field gel electrophoresis of causative S. pyogenes isolates obtained between 2005 and 2012. Results In total, 53 patients with STSS were included in this study. The median age of the patients was 57 years (range: 9–83 years), and 81.1% were male. The most prevalent underlying disease was diabetes mellitus (45.3%). Skin and soft-tissue infection accounted for 86.8% of STSS. The overall mortality rate was 32.1%. Underlying diseases had no statistical impact on mortality. A total of 19 different emm types were identified. The most prevalent emm type was emm102 (18.9%), followed by emm11 (17%), emm1 (11.3%), emm87 (9.4%), and emm89 (7.5%). There was no statistically significant association between emm type and a fatal outcome. Among the superantigen genes, speB was the most frequently detected one (92.5%), followed by smeZ (90.6%), speG (81.1%), speC (39.6%), and speF (39.6%). The majority of emm102 strains were found to have speB, speC, speG, and smeZ. The presence of speG was negatively associated with a fatal outcome (P = 0.045). Conclusions Our surveillance revealed the emergence of uncommon emm types, particularly emm102, causing STSS in southern Taiwan. Characterization of clinical, epidemiological, and molecular characteristics of STSS will improve our understanding of this life-threatening disease. PMID:24349115

  2. Expression of the fibronectin-binding components of Streptococcus pyogenes in Escherichia coli demonstrates that they are proteins.

    PubMed

    Talay, S R; Ehrenfeld, E; Chhatwal, G S; Timmis, K N

    1991-07-01

    The fibronectin-binding components (fbcs) of two clinical isolates and a culture collection strain of Streptococcus pyogenes have been analysed. Western immunoblotting of bacterial lysates which had been fractionated on polyacrylamide gels revealed trypsin-sensitive fibronectin-binding species. The genes specifying the fbcs were cloned from all three strains and expressed in Escherichia coli using a lambda EMBL3 vector. An fbc gene from the culture collection strain was subcloned and expressed in the E. coli expression vector pJLA601, and subjected to deletion analysis. The fibronectin-binding domain was thereby localized within a 40 kDa truncated peptide encoded by the 1000 bp C-terminal region of the gene. Southern hybridization experiments demonstrated that the analysed gene was present in the parental S. pyogenes chromosome, but not in the DNA of fbc expressing lambda clones obtained from the two clinical isolates. Further evidence for the existence of at least two different types of fbcs in group A streptococci was provided by Western blot analysis of recombinant phage lysates which revealed a complex series of fibronectin-binding species ranging from 120 to 200 kDa in size and showing strain-dependent variation in their patterns. As was the case with parental streptococcal strains all of the recombinant fbcs were protease-sensitive, and treatment with trypsin or pronase resulted in a total loss of fibronectin-binding activity. Competitive inhibition experiments indicated that lipoteichoic acid was not a significant fbc in the tested streptococcal strains.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Evolution of macrolide resistance in Streptococcus pyogenes over 14 years in an area of central Italy.

    PubMed

    Olivieri, Raffaela; Morandi, Matteo; Zanchi, Alessandra; Tordini, Giacinta; Pozzi, Gianni; De Luca, Andrea; Montagnani, Francesca

    2015-10-01

    We evaluated temporal fluctuations in macrolide resistance rates, analysing genetic determinants of resistance and clonal evolution in a population of 2744 S. pyogenes isolates collected in the period 2000-2013. The total resistance rate to erythromycin of the isolates was 17.9 %. A maximum of erythromycin resistance emerged in 2000 (38.6 %), followed by a significant decrease to 5.2 % in 2012 (P < 0.0001). Molecular analysis revealed the presence and co-presence of known genetic resistance determinants mefA, mefE, ermTR and ermB, in line with phenotypes. PFGE analysis identified genetically related groups in 2000 and 2007-2008, mainly the MLS and M phenotypes, respectively. The most prevalent emm types among a representative subset of resistant isolates were emm2, emm75 and emm77. All emm2 and 88.2 % of the strains harbouring the emm75 gene were only recorded in M-phenotype strains, whilst all emm77-positive strains had the inducible MLS phenotype. The analysed susceptible isolates showed several emm types partially shared with resistant ones. Our results suggest that changes in bacterial population clonality, rather than horizontal transfer of resistance determinants, plays a major epidemiological role in S. pyogenes. Continuous monitoring of microbiological epidemiology seems to be crucial for correct and effective management of streptococcal infections.

  4. A Highly Active and Negatively Charged Streptococcus pyogenes Lysin with a Rare d-Alanyl-l-Alanine Endopeptidase Activity Protects Mice against Streptococcal Bacteremia

    PubMed Central

    Lood, Rolf; Raz, Assaf; Molina, Henrik; Euler, Chad W.

    2014-01-01

    Bacteriophage endolysins have shown great efficacy in killing Gram-positive bacteria. PlyC, a group C streptococcal phage lysin, represents the most efficient lysin characterized to date, with a remarkably high specificity against different streptococcal species, including the important pathogen Streptococcus pyogenes. However, PlyC is a unique lysin, in terms of both its high activity and structure (two distinct subunits). We sought to discover and characterize a phage lysin active against S. pyogenes with an endolysin architecture distinct from that of PlyC to determine if it relies on the same mechanism of action as PlyC. In this study, we identified and characterized an endolysin, termed PlyPy (phage lysin from S. pyogenes), from a prophage infecting S. pyogenes. By in silico analysis, PlyPy was found to have a molecular mass of 27.8 kDa and a pI of 4.16. It was active against a majority of group A streptococci and displayed high levels of activity as well as binding specificity against group B and C streptococci, while it was less efficient against other streptococcal species. PlyPy showed the highest activity at neutral pH in the presence of calcium and NaCl. Surprisingly, its activity was not affected by the presence of the group A-specific carbohydrate, while the activity of PlyC was partly inhibited. Additionally, PlyPy was active in vivo and could rescue mice from systemic bacteremia. Finally, we developed a novel method to determine the peptidoglycan bond cleaved by lysins and concluded that PlyPy exhibits a rare d-alanyl-l-alanine endopeptidase activity. PlyPy thus represents the first lysin characterized from Streptococcus pyogenes and has a mechanism of action distinct from that of PlyC. PMID:24637688

  5. M-Protein Analysis of Streptococcus pyogenes Isolates Associated with Acute Rheumatic Fever in New Zealand.

    PubMed

    Williamson, Deborah A; Smeesters, Pierre R; Steer, Andrew C; Steemson, John D; Ng, Adrian C H; Proft, Thomas; Fraser, John D; Baker, Michael G; Morgan, Julie; Carter, Philip E; Moreland, Nicole J

    2015-11-01

    We applied an emm cluster typing system to group A Streptococcus strains in New Zealand, including those associated with acute rheumatic fever (ARF). We observed few so-called rheumatogenic emm types but found a high proportion of emm types previously associated with pyoderma, further suggesting a role for skin infection in ARF.

  6. 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.

  7. Dynamin inhibition interferes with inflammasome activation and cytokine gene expression in Streptococcus pyogenes-infected human macrophages

    PubMed Central

    Latvala, S; Mäkelä, S M; Miettinen, M; Charpentier, E; Julkunen, I

    2014-01-01

    In the present study, we have analysed the ability of Streptococcus pyogenes [Group A streptococcus (GAS)] to activate the NACHT-domain-, leucine-rich repeat- and PYD-containing protein 3 (NALP3) inflammasome complex in human monocyte-derived macrophages and the molecules and signalling pathways involved in GAS-induced inflammatory responses. We focused upon analysing the impact of dynamin-dependent endocytosis and the role of major streptococcal virulence factors streptolysin O (SLO) and streptolysin S (SLS) in the immune responses induced by GAS. These virulence factors are involved in immune evasion by forming pores in host cell membranes, and aid the bacteria to escape from the endosome–lysosome pathway. We analysed cytokine gene expression in human primary macrophages after stimulation with live or inactivated wild-type GAS as well as with live SLO and SLS defective bacteria. Interleukin (IL)-1β, IL-10, tumour necrosis factor (TNF)-α and chemokine (C-X-C motif) ligand (CXCL)-10 cytokines were produced after bacterial stimulation in a dose-dependent manner and no differences in cytokine levels were seen between live, inactivated or mutant bacteria. These data suggest that streptolysins or other secreted bacterial products are not required for the inflammatory responses induced by GAS. Our data indicate that inhibition of dynamin-dependent endocytosis in macrophages attenuates the induction of IL-1β, TNF-α, interferon (IFN)-β and CXCL-10 mRNAs. We also observed that pro-IL-1β protein was expressed and efficiently cleaved into mature-IL-1β via inflammasome activation after bacterial stimulation. Furthermore, we demonstrate that multiple signalling pathways are involved in GAS-stimulated inflammatory responses in human macrophages. PMID:25079511

  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. 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

  10. Preliminary validation of a novel high-resolution melt-based typing method based on the multilocus sequence typing scheme of Streptococcus pyogenes.

    PubMed

    Richardson, L J; Tong, S Y C; Towers, R J; Huygens, F; McGregor, K; Fagan, P K; Currie, B J; Carapetis, J R; Giffard, P M

    2011-09-01

    The major limitation of current typing methods for Streptococcus pyogenes, such as emm sequence typing and T typing, is that these are based on regions subject to considerable selective pressure. Multilocus sequence typing (MLST) is a better indicator of the genetic backbone of a strain but is not widely used due to high costs. The objective of this study was to develop a robust and cost-effective alternative to S. pyogenes MLST. A 10-member single nucleotide polymorphism (SNP) set that provides a Simpson's Index of Diversity (D) of 0.99 with respect to the S. pyogenes MLST database was derived. A typing format involving high-resolution melting (HRM) analysis of small fragments nucleated by each of the resolution-optimized SNPs was developed. The fragments were 59-119 bp in size and, based on differences in G+C content, were predicted to generate three to six resolvable HRM curves. The combination of curves across each of the 10 fragments can be used to generate a melt type (MelT) for each sequence type (ST). The 525 STs currently in the S. pyogenes MLST database are predicted to resolve into 298 distinct MelTs and the method is calculated to provide a D of 0.996 against the MLST database. The MelTs are concordant with the S. pyogenes population structure. To validate the method we examined clinical isolates of S. pyogenes of 70 STs. Curves were generated as predicted by G+C content discriminating the 70 STs into 65 distinct MelTs.

  11. 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.

  12. 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

  13. Structural insight into the substrate inhibition mechanism of NADP(+)-dependent succinic semialdehyde dehydrogenase from Streptococcus pyogenes.

    PubMed

    Jang, Eun Hyuk; Park, Seong Ah; Chi, Young Min; Lee, Ki Seog

    2015-06-01

    Succinic semialdehyde dehydrogenases (SSADHs) are ubiquitous enzymes that catalyze the oxidation of succinic semialdehyde (SSA) to succinic acid in the presence of NAD(P)(+), and play an important role in the cellular mechanisms including the detoxification of accumulated SSA or the survival in conditions of limited nutrients. Here, we report the inhibitory properties and two crystal structures of SSADH from Streptococcus pyogenes (SpSSADH) in a binary (ES) complex with SSA as the substrate and a ternary (ESS) complex with the substrate SSA and the inhibitory SSA, at 2.4 Å resolution for both structures. Analysis of the kinetic inhibitory parameters revealed significant substrate inhibition in the presence of NADP(+) at concentrations of SSA higher than 0.02 mM, which exhibited complete uncompetitive substrate inhibition with the inhibition constant (Ki) value of 0.10 ± 0.02 mM. In ES-complex of SpSSADH, the SSA showed a tightly bound bent form nearby the catalytic residues, which may be caused by reduction of the cavity volume for substrate binding, compared with other SSADHs. Moreover, structural comparison of ESS-complex with a binary complex with NADP(+) of SpSSADH indicated that the substrate inhibition was induced by the binding of inhibitory SSA in the cofactor-binding site, instead of NADP(+). Our results provide first structure-based molecular insights into the substrate inhibition mechanism of SpSSADH as the Gram-positive bacterial SSADH.

  14. Invasive infections due to Streptococcus pyogenes: seasonal variation of severity and clinical characteristics, Iceland, 1975 to 2012.

    PubMed

    Olafsdottir, L B; Erlendsdóttir, H; Melo-Cristino, J; Weinberger, D M; Ramirez, M; Kristinsson, K G; Gottfredsson, M

    2014-05-01

    Epidemiology and clinical characteristics of invasive Group A streptococcal infections (IGASI) are highly variable. Long-term studies are needed to understand the interplay between epidemiology and virulence. In a population-based study of IGASI in Iceland from 1975 to 2012, 288 cases were identified by positive cultures from normally sterile body sites. Charts were reviewed retrospectively and emm-types of viable Streptococcus pyogenes isolates (n=226) determined. Comparing the first and last decade of the study period, IGASI incidence increased from 1.09 to 3.96 cases per 100,000 inhabitants per year. The most common were emm types 1 (25%), 28 (11%) and 89 (11%); emm1 strains were most likely to cause severe infections. Infections in adults were significantly more likely to be severe during the seasonal peak from January to April (risk ratio: 2.36, 95% confidence interval: 1.34–4.15). Significant seasonal variability in severity was noted among patients with diagnosis of sepsis, respiratory infection and cellulitis, with 38% of severe infections in January to April compared with 16% in other months (p<0.01). A seasonal increase in severity of IGASI suggested that generalised seasonal increase in host susceptibility, rather than introduction of more virulent strains may play a role in the pathogenesis of these potentially fatal infections.

  15. A peptide antagonist of CD28 signaling attenuates toxic shock and necrotizing soft-tissue infection induced by Streptococcus pyogenes.

    PubMed

    Ramachandran, Girish; Tulapurkar, Mohan E; Harris, Kristina M; Arad, Gila; Shirvan, Anat; Shemesh, Ronen; Detolla, Louis J; Benazzi, Cinzia; Opal, Steven M; Kaempfer, Raymond; Cross, Alan S

    2013-06-15

    Staphylococcus aureus and group A Streptococcus pyogenes (GAS) express superantigen (SAg) exotoxin proteins capable of inducing lethal shock. To induce toxicity, SAgs must bind not only to the major histocompatibility complex II molecule of antigen-presenting cells and the variable β chain of the T-cell receptor but also to the dimer interface of the T-cell costimulatory receptor CD28. Here, we show that the CD28-mimetic peptide AB103 (originally designated "p2TA") protects mice from lethal challenge with streptococcal exotoxin A, as well as from lethal GAS bacterial infection in a murine model of necrotizing soft-tissue infection. Administration of a single dose of AB103 increased survival when given up to 5 hours after infection, reduced inflammatory cytokine expression and bacterial burden at the site of infection, and improved muscle inflammation in a dose-dependent manner, without compromising cellular and humoral immunity. Thus, AB103 merits further investigation as a potential therapeutic in SAg-mediated necrotizing soft-tissue infection.

  16. Prediction of surface exposed proteins in Streptococcus pyogenes, with a potential application to other Gram-positive bacteria.

    PubMed

    Barinov, Aleksandr; Loux, Valentin; Hammani, Amal; Nicolas, Pierre; Langella, Philippe; Ehrlich, Dusko; Maguin, Emmanuelle; van de Guchte, Maarten

    2009-01-01

    The in silico prediction of bacterial surface exposed proteins is of growing interest for the rational development of vaccines and in the study of bacteria-host relationships, whether pathogenic or host beneficial. This interest is driven by the increase in the use of DNA sequencing as a major tool in the early characterization of pathogenic bacteria and, more recently, even of complex ecosystems at the host-environment interface in metagenomics approaches. Current protein localization protocols are not suited to this prediction task as they ignore the potential surface exposition of many membrane-associated proteins. Therefore, we developed a new flow scheme, SurfG+, for the processing of protein sequence data with the particular aim of identification of potentially surface exposed (PSE) proteins from Gram-positive bacteria, which was validated for Streptococcus pyogenes. The results of an exploratory case study on closely related lactobacilli of the acidophilus group suggest that the yogurt bacterium Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) dedicates a relatively important fraction of its coding capacity to secreted proteins, while the probiotic gastrointestinal (GI) tract bacteria L. johnsonii and L. gasseri appear to encode a larger variety of PSE proteins, that may play a role in the interaction with the host.

  17. Crystal Structures of Δ1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes

    PubMed Central

    Nocek, B.; Chang, C.; Li, H.; Lezondra, L.; Holzle, D.; Collart, F.; Joachimiak, A.

    2009-01-01

    L-Proline is an amino acid that plays an important role in proteins uniquely contributing to protein folding, structure, and stability, and this amino acid serves as a sequence-recognition motif. Proline biosynthesis can occur via two pathways, one from glutamate and the other from arginine. In both pathways, the last step of biosynthesis, the conversion of Δ1-pyrroline-5-carboxylate (P5C) to L-proline, is catalyzed by Δ1-pyrroline-5-carboxylate reductase (P5CR) using NAD(P)H as a cofactor. We have determined the first crystal structure of P5CR from two human pathogens, Neisseria meningitides and Streptococcus pyogenes, at 2.0Å and 2.15Å resolution, respectively. The catalytic unit of P5CR is a dimer composed of two domains, but the biological unit seems to be species-specific. The N-terminal domain of P5CR is an α/β/α sandwich, a Rossmann fold. The C-terminal dimerization domain is rich in α-helices and shows domain swapping. Comparison of the native structure of P5CR to structures complexed with L-proline and NADP+ in two quite different primary sequence backgrounds provides unique information about key functional features: the active site and the catalytic mechanism. The inhibitory L-proline has been observed in the crystal structure. PMID:16233902

  18. Antimicrobial Susceptibilities of 1,684 Streptococcus pneumoniae and 2,039 Streptococcus pyogenes Isolates and Their Ecological Relationships: Results of a 1-Year (1998–1999) Multicenter Surveillance Study in Spain

    PubMed Central

    Pérez-Trallero, E.; Fernández-Mazarrasa, C.; García-Rey, C.; Bouza, E.; Aguilar, L.; García-de-Lomas, J.; Baquero, F.

    2001-01-01

    A nationwide multicenter susceptibility surveillance study which included 1,684 Streptococcus pneumoniae and 2,039 S. pyogenes isolates was carried out over 1 year in order to assess the current resistance patterns for the two most important gram-positive microorganisms responsible for community-acquired infections in Spain. Susceptibility testing was done by a broth microdilution method according to National Committee for Clinical Laboratory Standards M100-S10 interpretative criteria. For S. pneumoniae, the prevalences of highly resistant strains were 5% for amoxicillin and amoxicillin-clavulanic acid; 7% for cefotaxime; 22% for penicillin; 31% for cefuroxime; 35% for erythromycin, clarithromycin, and azithromycin; and 42% for cefaclor. For S. pyogenes, the prevalence of erythromycin resistance was 20%. Efflux was encountered in 90% of S. pyogenes and 5% of S. pneumoniae isolates that exhibited erythromycin resistance. Erythromycin resistance was associated with clarithromycin and azithromycin in both species, regardless of phenotype. Despite the different nature of the mechanisms of resistance, a positive correlation (r = 0.612) between the two species in the prevalence of erythromycin resistance was found in site-by-site comparisons, suggesting some kind of link with antibiotic consumption. Regarding ciprofloxacin, the MIC was ≥4 μg/ml for 7% of S. pneumoniae and 3.5% of S. pyogenes isolates. Ciprofloxacin resistance (MIC, ≥4 μg/ml) was significantly (P < 0.05) associated with macrolide resistance in both S. pyogenes and S. pneumoniae and with penicillin nonsusceptibility in S. pneumoniae. PMID:11709305

  19. Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of SpyCEP, a candidate antigen for a vaccine against Streptococcus pyogenes.

    PubMed

    Abate, Francesca; Malito, Enrico; Falugi, Fabiana; Margarit Y Ros, Immaculada; Bottomley, Matthew James

    2013-10-01

    Streptococcus pyogenes (Group A streptococcus; GAS) is an important human pathogen against which an effective vaccine does not yet exist. The S. pyogenes protein SpyCEP (S. pyogenes cell-envelope proteinase) is a surface-exposed subtilisin-like serine protease of 1647 amino acids. In addition to its auto-protease activity, SpyCEP is capable of cleaving interleukin 8 and related chemokines, contributing to GAS immune-evasion strategies. SpyCEP is immunogenic and confers protection in animal models of GAS infections. In order to structurally characterize this promising vaccine candidate, several SpyCEP protein-expression constructs were designed, cloned, produced in Escherichia coli, purified by affinity chromatography and subjected to crystallization trials. Crystals of a selenomethionyl form of a near-full-length SpyCEP ectodomain were obtained. The crystals diffracted X-rays to 3.3 Å resolution and belonged to space group C2, with unit-cell parameters a=139.2, b=120.4, c=104.3 Å, β=111°.

  20. Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of SpyCEP, a candidate antigen for a vaccine against Streptococcus pyogenes

    PubMed Central

    Abate, Francesca; Malito, Enrico; Falugi, Fabiana; Margarit Y Ros, Immaculada; Bottomley, Matthew James

    2013-01-01

    Streptococcus pyogenes (Group A streptococcus; GAS) is an important human pathogen against which an effective vaccine does not yet exist. The S. pyogenes protein SpyCEP (S. pyogenes cell-envelope proteinase) is a surface-exposed subtilisin-like serine protease of 1647 amino acids. In addition to its auto-protease activity, SpyCEP is capable of cleaving interleukin 8 and related chemokines, contributing to GAS immune-evasion strategies. SpyCEP is immunogenic and confers protection in animal models of GAS infections. In order to structurally characterize this promising vaccine candidate, several SpyCEP protein-expression constructs were designed, cloned, produced in Escherichia coli, purified by affinity chromatography and subjected to crystallization trials. Crystals of a selenomethionyl form of a near-full-length SpyCEP ectodomain were obtained. The crystals diffracted X-rays to 3.3 Å resolution and belonged to space group C2, with unit-cell parameters a = 139.2, b = 120.4, c = 104.3 Å, β = 111°. PMID:24100558

  1. 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.

  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. 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

  4. 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

  5. In vivo expression of Streptococcus pyogenes immunogenic proteins during tibial foreign body infection.

    PubMed

    Freiberg, Jeffrey A; McIver, Kevin S; Shirtliff, Mark E

    2014-09-01

    Group A streptococcus (GAS) is an important human pathogen that causes a number of diseases with a wide range of severities. While all known strains of GAS are still sensitive to penicillin, there have been reports of antibiotic treatment failure in as many as 20% to 40% of cases. Biofilm formation has been implicated as a possible cause for these failures. A biofilm is a microbially derived, sessile community where cells grow attached to a surface or as a bacterial conglomerate and surrounded by a complex extracellular matrix. While the ability of group A streptococcus to form biofilms in the laboratory has been shown, there is a lack of understanding of the role of GAS biofilms during an infection. We hypothesized that during infections, GAS exhibits a biofilm phenotype, complete with unique protein expression. To test this hypothesis, a rabbit model of GAS osteomyelitis was developed. A rabbit was inoculated with GAS using an infected indwelling device. Following the infection, blood and tissue samples were collected. Histological samples of the infected tibia were prepared, and the formation of a biofilm in vivo was visualized using peptide nucleic acid fluorescent in situ hybridization (PNA-FISH) and confocal microscopy. In addition, Western blotting with convalescent rabbit serum detected cell wall proteins expressed in vitro under biofilm and planktonic growth conditions. Immunogenic proteins were then identified using matrix-assisted laser desorption ionization-time of flight tandem mass spectrometry (MALDI-TOF/TOF MS). These identities, along with the in vivo results, support the hypothesis that GAS forms biofilms during an infection. This unique phenotype should be taken into consideration when designing a vaccine or any other treatment for group A streptococcus infections.

  6. The ancillary protein 1 of Streptococcus pyogenes FCT-1 pili mediates cell adhesion and biofilm formation through heterophilic as well as homophilic interactions

    PubMed Central

    Becherelli, Marco; Manetti, Andrea G O; Buccato, Scilla; Viciani, Elisa; Ciucchi, Laura; Mollica, Giulia; Grandi, Guido; Margarit, Imma

    2012-01-01

    Summary Gram-positive pili are known to play a role in bacterial adhesion to epithelial cells and in the formation of biofilm microbial communities. In the present study we undertook the functional characterization of the pilus ancillary protein 1 (AP1_M6) from Streptococcus pyogenes isolates expressing the FCT-1 pilus variant, known to be strong biofilm formers. Cell binding and biofilm formation assays using S. pyogenes in-frame deletion mutants, Lactococcus expressing heterologous FCT-1 pili and purified recombinant AP1_M6, indicated that this pilin is a strong cell adhesin that is also involved in bacterial biofilm formation. Moreover, we show that AP1_M6 establishes homophilic interactions that mediate inter-bacterial contact, possibly promoting bacterial colonization of target epithelial cells in the form of three-dimensional microcolonies. Finally, AP1_M6 knockout mutants were less virulent in mice, indicating that this protein is also implicated in GAS systemic infection. PMID:22320452

  7. 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

  8. Differences between Macrolide-Resistant and -Susceptible Streptococcus pyogenes: Importance of Clonal Properties in Addition to Antibiotic Consumption

    PubMed Central

    Silva-Costa, C.; Friães, A.; Melo-Cristino, J.

    2012-01-01

    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

  9. 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

  10. 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

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

    PubMed

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

    2010-08-01

    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.

  12. Haemolysin-deficient variants of Streptococcus pyogenes and S. dysgalactiae subsp. equisimilis may be overlooked as aetiological agents of pharyngitis.

    PubMed

    Dierksen, K P; Tagg, J R

    2000-09-01

    Variants of large colony beta-haemolytic Lancefield group A, C and G streptococci that are non-haemolytic or alpha-haemolytic on sheep blood agar have been detected in clinical specimens due to their enhanced haemolytic activity when grown on a new selective and differential blood agar medium containing colistin, nalidixic acid and pH 7.5-adjusted PIPES buffer (CNA-P). The large colony Lancefield group C and G isolates were identified as Streptococcus dysgalactiae subsp. equisimilis by API 20 Strep classification and 16S rDNA profiling. The haemolytic activity of these variants on various blood agar media, including CNA-P, was closely similar to that of known streptolysin S-defective mutants of S. pyogenes and was blocked by addition of cholesterol, a specific inhibitor of the streptolysin O family of haemolysins. As haemolysin variants could be detected in large numbers in cultures from patients with clinical symptoms of pharyngitis it is suggested that they may function as primary pathogens in such infections. The high frequency with which haemolysin variants were isolated from clinical specimens during a 3-month trial (3%, 13% and 10%, respectively, of group A, C and G streptococcal isolates) indicated that a substantial proportion of streptococcal infections may go undetected if only conventional sheep blood agar media are used in clinical laboratories for the detection of beta-haemolytic streptococci. As haemolysin variants have been implicated in the development of serious streptococcal sequelae, further investigation of the full extent of their contribution to streptococcal disease is indicated.

  13. A case of varicella complicated by cellulitis and scarlet fever due to Streptococcus pyogenes.

    PubMed

    Oyake, S; Ohi, T; Koga, M

    2000-11-01

    We report a 4-year-old boy with cellulitis and scarlet fever due to streptococcal infection following the onset of varicella. He developed a painful ulcer and subcutaneous induration on the left shoulder and a small, light-red-colored rash on the trunk at approximately the same time as the development of vesicles over the entire body. Streptococcus pyrogenes was isolated from samples from the posterior intranasal space and the ulcer on the shoulder. The clinical symptoms improved with the administration of antibiotics and intravenous drip infusion, but it took approximately one month from the first visit for the subcutaneous induration to disappear and the ulcer to heal with epithelialization. The complication of secondary streptococcal infection in varicella is relatively rare in Japan, but in Western countries there have been many reported cases of life-threatening necrotizing fasciitis and necrotizing pyomyositis due to secondary streptococcal infection following varicella. Close attention should be paid to streptococcal infection as a complication of varicella.

  14. 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

  15. High-resolution crystal structure of Streptococcus pyogenes β-NAD+ glycohydrolase in complex with its endogenous inhibitor IFS reveals a highly water-rich interface

    PubMed Central

    Yoon, Ji Young; An, Doo Ri; Yoon, Hye-Jin; Kim, Hyoun Sook; Lee, Sang Jae; Im, Ha Na; Jang, Jun Young; Suh, Se Won

    2013-01-01

    One of the virulence factors produced by Streptococcus pyogenes is β-NAD+ glycohydrolase (SPN). S. pyogenes injects SPN into the cytosol of an infected host cell using the cytolysin-mediated translocation pathway. As SPN is toxic to bacterial cells themselves, S. pyogenes possesses the ifs gene that encodes an endogenous inhibitor for SPN (IFS). IFS is localized intracellularly and forms a complex with SPN. This intracellular complex must be dissociated during export through the cell envelope. To provide a structural basis for understanding the interactions between SPN and IFS, the complex was overexpressed between the mature SPN (residues 38–451) and the full-length IFS (residues 1–161), but it could not be crystallized. Therefore, limited proteolysis was used to isolate a crystallizable SPNct–IFS complex, which consists of the SPN C-terminal domain (SPNct; residues 193–451) and the full-length IFS. Its crystal structure has been determined by single anomalous diffraction and the model refined at 1.70 Å resolution. Interestingly, our high-resolution structure of the complex reveals that the interface between SPNct and IFS is highly rich in water molecules and many of the interactions are water-mediated. The wet interface may facilitate the dissociation of the complex for translocation across the cell envelope. PMID:24121349

  16. CD46 transgenic mouse model of necrotizing fasciitis caused by Streptococcus pyogenes infection.

    PubMed

    Matsui, Hidenori; Sekiya, Yukie; Nakamura, Masahiko; Murayama, Somay Yamagata; Yoshida, Haruno; Takahashi, Tetsufumi; Imanishi, Ken'ichi; Tsuchimoto, Kanji; Uchiyama, Takehiko; Sunakawa, Keisuke; Ubukata, Kimiko

    2009-11-01

    We developed a human CD46-expressing transgenic (Tg) mouse model of subcutaneous (s.c.) infection into both hind footpads with clinically isolated 11 group A streptococcus (GAS) serotype M1 strains. When the severity levels of foot lesions at 72 h and the mortality rates by 336 h were compared after s.c. infection with 1x10(7) CFU of each GAS strain, the GAS472 strain, isolated from the blood of a patient suffering from streptococcal toxic shock syndrome (STSS), induced the highest severity levels and mortality rates. GAS472 led to a 100% mortality rate in CD46 Tg mice after only 168 h postinfection through the supervention of severe necrotizing fasciitis (NF) of the feet. In contrast, GAS472 led to a 10% mortality rate in non-Tg mice through the supervention of partial necrotizing cutaneous lesions of the feet. The footpad skin sections of CD46 Tg mice showed hemorrhaging and necrotic striated muscle layers in the dermis, along with the exfoliation of epidermis with intracellular edema until 48 h after s.c. infection with GAS472. Thereafter, the bacteria proliferated, reaching a 90-fold or 7-fold increase in the livers of CD46 Tg mice or non-Tg mice, respectively, for 24 h between 48 and 72 h after s.c. infection with GAS472. As a result, the infected CD46 Tg mice appeared to suffer severe liver injuries. These findings suggest that human CD46 enhanced the progression of NF in the feet and the exponential growth of bacteria in deep tissues, leading to death.

  17. 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

  18. Application of an enzyme-labeled antigen method for visualizing plasma cells producing antibodies against Strep A, a carbohydrate antigen of Streptococcus pyogenes, in recurrent tonsillitis.

    PubMed

    Onouchi, Takanori; Mizutani, Yasuyoshi; Shiogama, Kazuya; Inada, Ken-ichi; Okada, Tatsuyoshi; Naito, Kensei; Tsutsumi, Yutaka

    2015-01-01

    Streptococcus pyogenes is the main causative pathogen of recurrent tonsillitis. Histologically, lesions of recurrent tonsillitis contain numerous plasma cells. Strep A is an antigenic carbohydrate molecule on the cell wall of S. pyogenes. As expected, plasma cells in subjects with recurrent tonsillitis secrete antibodies against Strep A. The enzyme-labeled antigen method is a novel histochemical technique that visualizes specific antibody-producing cells in tissue sections by employing a biotin-labeled antigen as a probe. The purpose of the present study was to visualize plasma cells producing antibodies reactive with Strep A in recurrent tonsillitis. Firstly, the lymph nodes of rats immunized with boiled S. pyogenes were paraformaldehyde-fixed and specific plasma cells localized in frozen sections with biotinylated Strep A. Secondly, an enzyme-labeled antigen method was used on human tonsil surgically removed from 12 patients with recurrent tonsillitis. S. pyogenes genomes were PCR-detected in all 12 specimens. The emm genotypes belonged to emm12 in nine specimens and emm1 in three. Plasma cells producing anti-Strep A antibodies were demonstrated in prefixed frozen sections of rat lymph nodes, 8/12 human specimens from patients with recurrent tonsillitis but not in two control tonsils. In human tonsils, Strep A-reactive plasma cells were observed within the reticular squamous mucosa and just below the mucosa, and the specific antibodies belonged to either IgA or IgG classes. Our technique is effective in visualizing immunocytes producing specific antibodies against the bacterial carbohydrate antigen, and is thus a novel histochemical tool for analyzing immune reactions in infectious disorders.

  19. Upregulation of capsule enables Streptococcus pyogenes to evade immune recognition by antigen-specific antibodies directed to the G-related alpha2-macroglobulin-binding protein GRAB located on the bacterial surface.

    PubMed

    Dinkla, Katrin; Sastalla, Inka; Godehardt, Antonia W; Janze, Nina; Chhatwal, Gursharan S; Rohde, Manfred; Medina, Eva

    2007-07-01

    One of the major problems associated with the development of a vaccine against Streptococcus pyogenes is the ability of this pathogen to escape recognition by antibodies directed against conserved surface-associated determinants and to establish infection in the setting of an acquired immune response. Identification of the mechanism(s) used by S. pyogenes to avoid recognition by antigen-specific antibodies and escape killing in blood was the focus of this study. We showed here that S. pyogenes was capable of surviving in human blood containing high levels of antibodies directed against the G-related alpha2-macroglobulin-binding protein GRAB, a highly conserved bacterial surface protein. S. pyogenes upregulated the hyaluronic acid capsule production during incubation with human blood, suggesting that the capsule may structurally minimize antibody access to protein GRAB. This hypothesis was confirmed by the ability of anti-GRAB antibodies to promote opsonophagocytosis of a capsule-deficient mutant of S. pyogenes but not of the encapsulated wild-type strain. Capsule upregulation and protection of S. pyogenes from opsonophagocytosis in the presence of anti-GRAB antibodies was also observed in a murine model of streptococcal infection. Thus, masking of surface immunogenic determinants by the hyaluronic acid capsule may constitute a novel mechanism of S. pyogenes for evasion of antigen-specific antibodies.

  20. 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

  1. Simultaneous isolation of emm89-type Streptococcus pyogenes strains with a wild-type or mutated covS gene from a single streptococcal toxic shock syndrome patient.

    PubMed

    Masuno, Katsuaki; Okada, Ryo; Zhang, Yan; Isaka, Masanori; Tatsuno, Ichiro; Shibata, Shinichiro; Hasegawa, Tadao

    2014-04-01

    Streptococcal toxic shock syndrome (STSS) is a re-emerging infectious disease in many developed countries. Recent studies have suggested that mutations in CovRS, a two-component regulatory system in Streptococcus pyogenes, play important roles in the pathogenesis of STSS. However, in vivo evidence of the significance of CovRS in human infections has not been fully demonstrated. We investigated five S. pyogenes strains isolated simultaneously from the pharynx, sputum, knee joint, cerebrospinal fluid and blood of a single STSS patient. All were emm89-type strains, and multilocus sequence typing (MLST) analysis revealed that the strains of pharynx and blood were isogenic. The growth rates of the strains from pharynx and sputum were faster than those of the other strains. Protein profiles of the culture supernatants of strains from the pharynx and sputum were also different from those of the other strains. Sequence analyses revealed that strains from the knee joint, cerebrospinal fluid and blood contained a single nucleotide difference in the covS coding region, resulting in one amino acid change, compared with the other strains. Introduction of a plasmid containing the covS gene from the pharynx strain to the blood strain increased the production of SpeB protein. This suggests that the one amino acid alteration in CovS was relevant to pathogenesis. This report supports the idea that mutated CovS plays important roles in vivo in the dissemination of S. pyogenes from the upper respiratory tract of human to aseptic tissues such as blood and cerebrospinal fluid.

  2. 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

  3. In vitro induction of resistance by tissue concentrations of azithromycin, clarithromycin, cefixime and amoxicillin/clavulanate in clinical isolates of Streptococcus pyogenes.

    PubMed

    De Vecchi, E; Nicola, L; Zucchetti, E; Drago, L

    2006-08-01

    This study evaluated the effects of exposure to serum, tonsils and breakpoint drug concentrations of clarithromycin, azithromycin, cefixime and amoxicillin/clavulanate on Streptococcus pyogenes susceptibility. Frequency of mutation and development of resistance after ten passages on antibiotic gradient plates, followed by ten passages without antibiotic, were determined. Phenotypes of macrolide-resistant strains grown at the end of multi-step selection were also determined. Azithromycin induced a surge of resistant strains more rapidly and frequently than clarithromycin, particularly at tonsils concentrations. With amoxicillin/clavulanate no strains showed minimum inhibitory concentrations (MICs) higher than the susceptibility breakpoint. Mutational frequencies were higher for azithromycin, at serum and breakpoint drug concentrations, than for the other drugs. Most of the macrolide resistant strains showed an MLS(B) phenotype. In conclusion, the ability to prevent the occurrence of resistance in clinical isolates of S. pyogenes was similar for amoxicillin/clavulanate and clarithromycin followed by cefixime > azithromycin when tonsil drug concentrations were considered, and greater for amoxicillin/clavulanate followed by clarithromycin > cefixime> azithromycin, at breakpoint and serum concentrations.

  4. Crystal Structure of Streptococcus pyogenes Cas1 and Its Interaction with Csn2 in the Type II CRISPR-Cas System.

    PubMed

    Ka, Donghyun; Lee, Hasup; Jung, Yi-Deun; Kim, Kyunggon; Seok, Chaok; Suh, Nayoung; Bae, Euiyoung

    2016-01-01

    CRISPRs and Cas proteins constitute an RNA-guided microbial immune system against invading nucleic acids. Cas1 is a universal Cas protein found in all three types of CRISPR-Cas systems, and its role is implicated in new spacer acquisition during CRISPR-mediated adaptive immunity. Here, we report the crystal structure of Streptococcus pyogenes Cas1 (SpCas1) in a type II CRISPR-Cas system and characterize its interaction with S. pyogenes Csn2 (SpCsn2). The SpCas1 structure reveals a unique conformational state distinct from type I Cas1 structures, resulting in a more extensive dimerization interface, a more globular overall structure, and a disruption of potential metal-binding sites for catalysis. We demonstrate that SpCas1 directly interacts with SpCsn2, and identify the binding interface and key residues for Cas complex formation. These results provide structural information for a type II Cas1 protein, and lay a foundation for studying multiprotein Cas complexes functioning in type II CRISPR-Cas systems.

  5. Hyporesponsiveness of peripheral blood lymphocytes to streptococcal superantigens in patients with guttate psoriasis: evidence for systemic stimulation of T cells with superantigens released from focally infecting Streptococcus pyogenes.

    PubMed

    Tokura, Y; Seo, N; Ohshima, A; Wakita, H; Yokote, R; Furukawa, F; Takigawa, M

    1999-01-01

    Throat infection with Streptococcus pyogenes is the most important trigger for acute guttate psoriasis. We examined the in vitro responses of peripheral blood mononuclear cells (PBMC) to streptococcal superantigens, SPEA and SPEC, and staphylococcal superantigens, SEB and TSST-1, in patients with guttate psoriasis, in patients with chronic plaque psoriasis, and in healthy subjects. PBMC from patients with guttate psoriasis responded poorly to SPEA and SPEC at concentrations of 0.1 and 1 ng/ml as compared with those from patients with plaque psoriasis, but showed high responses to SEB and TSST-1. The hyporesponsiveness recovered after improvement of the skin eruption. There was no significant difference between guttate and chronic types of psoriasis in the percentage of circulating T-cell receptor BV2 or BV8-bearing T cells, responsive to streptococcal superantigens, indicating that T-cell clonal anergy was a mechanism underlying the hyporesponsiveness. Our results suggest that superantigens released from focally infecting S. pyogenes induce a transient activation of relevant T cells, leading to the development of skin eruption and, subsequently, temporary T-cell anergy to these toxins.

  6. Phage-Like Streptococcus pyogenes Chromosomal Islands (SpyCI) and Mutator Phenotypes: Control by Growth State and Rescue by a SpyCI-Encoded Promoter.

    PubMed

    Scott, Julie; Nguyen, Scott V; King, Catherine J; Hendrickson, Christina; McShan, W Michael

    2012-01-01

    We recently showed that a prophage-like Streptococcus pyogenes chromosomal island (SpyCI) controls DNA mismatch repair and other repair functions in M1 genome strain SF370 by dynamic excision and reintegration into the 5' end of mutL in response to growth, causing the cell to alternate between a wild type and mutator phenotype. Nine of the 16 completed S. pyogenes genomes contain related SpyCI integrated into the identical attachment site in mutL, and in this study we examined a number of these strains to determine whether they also had a mutator phenotype as in SF370. With the exception of M5 genome strain Manfredo, all demonstrated a mutator phenotype as compared to SpyCI-free strain NZ131. The integrase gene (int) in the SpyCIM5 contains a deletion that rendered it inactive, and this deletion predicts that Manfredo would have a pronounced mutator phenotype. Remarkably, this was found not to be the case, but rather a cryptic promoter within the int ORF was identified that ensured constitutive expression of mutL and the downstream genes encoded on the same mRNA, providing a striking example of rescue of gene function following decay of a mobile genetic element. The frequent occurrence of SpyCI in the group A streptococci may facilitate bacterial survival by conferring an inducible mutator phenotype that promotes adaptation in the face of environmental challenges or host immunity.

  7. Boesenbergia pandurata (Roxb.) Schltr., Eleutherine americana Merr. and Rhodomyrtus tomentosa (Aiton) Hassk. as antibiofilm producing and antiquorum sensing in Streptococcus pyogenes.

    PubMed

    Limsuwan, Surasak; Voravuthikunchai, Supayang Piyawan

    2008-08-01

    Biofilm formation has been demonstrated as a potentially important mechanism contributing to antibiotic treatment failure on Streptococcus pyogenes. It could play a significant role in recurrent and chronic infections. Boesenbergia pandurata (Roxb.) Schltr., Eleutherine americana Merr. and Rhodomyrtus tomentosa (Aiton) Hassk. have been previously reported from our laboratory as effective agents against S. pyogenes. Therefore, in the present study, we observed the effect of these plants on biofilm formation. The bacterial biofilms were quantified by safranin staining and absorbance at 492 nm. The results clearly demonstrated that all subinhibitory concentrations [1/32-1/2 minimal inhibitory concentration (MIC)] of E. americana (7.81-125 microg mL(-1)) and R. tomentosa (0.24-7.81 microg mL(-1)) extracts significantly prevented biofilm formation while 1/2MIC (7.81 microg mL(-1)) of B. pandurata extract produced this effect. The issue of antiquorum sensing of this pathogenic bacterium has been further explored. A correlation between antiquorum-sensing and antibiofilm-producing activities was demonstrated. Strong inhibition on quorum sensing was displayed with the extract of R. tomentosa. Eleutherine americana extract showed partial inhibition, while B. pandurata did not show this activity. By contrast, an assay of microbial adhesion to hydrocarbon revealed no changes in the cell-surface hydrophobicity of the treated organisms. Active organisms with the ability to inhibit quorum sensing and biofilm formation are worth studying as they may provide complimentary medicine for biofilm-associated infections. PMID:18631184

  8. 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

  9. 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

  10. Differential secretomics of Streptococcus pyogenes reveals a novel peroxide regulator (PerR)-regulated extracellular virulence factor mitogen factor 3 (MF3).

    PubMed

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

    2011-09-01

    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

  11. 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

  12. 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

  13. 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

  14. 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

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

    PubMed

    Hendrickson, Christina; Euler, Chad W; 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 environments.

  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. 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.

  18. 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

  19. 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

  20. Crystal structure of omega transcriptional repressor encoded by Streptococcus pyogenes plasmid pSM19035 at 1.5 A resolution.

    PubMed

    Murayama, K; Orth, P; de la Hoz, A B; Alonso, J C; Saenger, W

    2001-12-01

    The 71 amino acid residue omega protein encoded by the Streptococcus pyogenes non-conjugative plasmid pSM19035 is a transcriptional repressor that regulates expression of genes for copy number control and stable maintenance of plasmids. The crystal structure of omega protein has been determined by multiple isomorphous replacement, including anomalous scattering and refined to an R-factor of 21.1 % (R(free)=23.2 %) at 1.5 A resolution. Two monomers related by a non-crystallographic 2-fold axis form a homodimer that occupies the asymmetric unit. Each polypeptide chain is folded into two alpha-helices and one beta-strand forming an antiparallel beta-ribbon in the homodimer. The N-terminal regions (1-23 and 1-22 in subunits I and II, respectively) are not defined in the electron density due to proteolysis of the N-terminal 20 amino acid residues during crystallisation and partial disorder. The omega protein belongs to the structural superfamily of MetJ/Arc repressors featuring a ribbon-helix-helix DNA-binding motif with the beta-ribbon located in and recognizing the major groove of operator DNA; according to a modelled omega protein-DNA complex, residues Arg31 and Arg31' on the beta-ribbon are in positions to interact with a nucleobase, especially guanine. PMID:11733997

  1. Crystal structure of omega transcriptional repressor encoded by Streptococcus pyogenes plasmid pSM19035 at 1.5 A resolution.

    PubMed

    Murayama, K; Orth, P; de la Hoz, A B; Alonso, J C; Saenger, W

    2001-12-01

    The 71 amino acid residue omega protein encoded by the Streptococcus pyogenes non-conjugative plasmid pSM19035 is a transcriptional repressor that regulates expression of genes for copy number control and stable maintenance of plasmids. The crystal structure of omega protein has been determined by multiple isomorphous replacement, including anomalous scattering and refined to an R-factor of 21.1 % (R(free)=23.2 %) at 1.5 A resolution. Two monomers related by a non-crystallographic 2-fold axis form a homodimer that occupies the asymmetric unit. Each polypeptide chain is folded into two alpha-helices and one beta-strand forming an antiparallel beta-ribbon in the homodimer. The N-terminal regions (1-23 and 1-22 in subunits I and II, respectively) are not defined in the electron density due to proteolysis of the N-terminal 20 amino acid residues during crystallisation and partial disorder. The omega protein belongs to the structural superfamily of MetJ/Arc repressors featuring a ribbon-helix-helix DNA-binding motif with the beta-ribbon located in and recognizing the major groove of operator DNA; according to a modelled omega protein-DNA complex, residues Arg31 and Arg31' on the beta-ribbon are in positions to interact with a nucleobase, especially guanine.

  2. Crystallization and preliminary X-ray diffraction studies of the epsilonzeta addiction system encoded by Streptococcus pyogenes plasmid pSM19035.

    PubMed

    Meinhart, A; Alings, C; Sträter, N; Camacho, A G; Alonso, J C; Saenger, W

    2001-05-01

    The proteins encoded by the Streptococcus pyogenes broad-host range and low copy-number plasmid pSM19035 form a toxin-antitoxin module that secures stable maintenance by causing the death of plasmid-free segregants. The epsilonzeta protein complex was crystallized in four different forms at pH 5.0 and pH 7.0 using the vapour-diffusion method with PEG 3350 and ethylene glycol as precipitants. Three of the crystal forms were obtained in the same droplet under identical conditions at pH 5.0. One form belongs to the enantiomorphic space groups P4(3)2(1)2 or P4(1)2(1)2. For the other two, the X-ray reflection conditions match those of space group P2(1)2(1)2(1), one representing a superlattice of the other. A crystal form growing at pH 7.0 also belongs to space group P2(1)2(1)2(1), but there is no indication of a structural relationship to the other orthorhombic forms. Initially, the crystals diffracted to 2.9 A resolution and diffracted to 1.95 A after soaking at pH 7.0. A preparation of selenomethionyl epsilonzeta protein complex yielded single crystals suitable for X-ray diffraction experiments using synchrotron sources.

  3. [Carriage of Streptococcus pyogenes in primary school children: M-protein types, pyrogenic toxin genes, and investigation of the clonal relationships between the isolates].

    PubMed

    Otlu, Barış; Karakurt, Cemşit; Bayındır, Yaşar; Kayabaş, Üner; Yakupoğulları, Yusuf; Gözükara Bağ, Harika

    2015-07-01

    M-protein and pyrogenic toxins are the most important virulence factors of Streptococcus pyogenes, and they play significant role in the pathophysiology of acute rheumatoid fever and scarlet fever, respectively. In this study, the pharyngeal carriage of S.pyogenes of the primary school children, clonal relationship of the strains, M-protein types, and the presence of pyrogenic toxin genes were aimed to be investigated. A total of 668 throat cultures obtained from children (age range: 6-16 years) in two primary schools in our region, were included in the study. The clonal relationships of the isolated group A streptococci (GAS) strains were investigated by DiversiLab assay (BioMérieux, France), and the clonal relatedness was confirmed by pulsed-field gel electrophoresis (PFGE) method. M-protein (emm) typing was performed by DNA sequencing as suggested by Centers for Disease Control and Prevention (CDC). The genes encoding pyrogenic toxins, speA and speC, were investigated by an in-house multiplex polymerase chain reaction (PCR) method. S.pyogenes was isolated from 134 (20.05%) of the throat samples. The GAS carriage rate of the students aged ≥10 was statistically higher than those 7-9 years age group (%22 vs %16.4, p<0.05). The M protein gene could be characterized only among 123 isolates by DNA sequencing, and 20 different emm types were detected. The most frequent emm type was emm1 (n=38, 30.9%) followed by emm12 (n=18, 14.6%), emm89 (n=10, 8.1%), emm118 (n=9, 7.3%), and emm4 (n=7, 5.7%). Pyrogenic toxin genes were found in 25 (18.6%) of the isolates, including speA in 11 isolates (8.2%) and speC in 12 isolates (8.9%) and both genes were detected in 2 isolates (1.5%). Sixty-two different Rep (Repetitive extragenic palindromic)-PCR profiles were detected in 134 S.pyogenes isolates by DiversiLab method. Thirteen different clusters were formed by a total of clonally related 36 isolates revealing a strain clustering ratio of 26.9%. Clonal relationship of all

  4. Crystallization and preliminary X-ray crystallographic analysis of the variable domain of Scl2.3, a streptococcal collagen-like protein from invasive M3-type Streptococcus pyogenes.

    PubMed

    Squeglia, Flavia; Bachert, Beth; Romano, Maria; Lukomski, Slawomir; Berisio, Rita

    2013-09-01

    Streptococcal collagen-like proteins (Scls) are widely expressed by the well recognized human pathogen Streptococcus pyogenes. These surface proteins contain a signature central collagen-like region and an amino-terminal globular domain, termed the variable domain, which is protruded away from the cell surface by the collagen-like domain. Despite their recognized importance in bacterial pathogenicity, no structural information is presently available on proteins of the Scl class. The variable domain of Scl2 from invasive M3-type S. pyogenes has successfully been crystallized using vapour-diffusion methods. The crystals diffracted to 1.5 Å resolution and belonged to space group H32, with unit-cell parameters a = 44.23, b = 44.23, c = 227.83 Å. The crystal structure was solved by single-wavelength anomalous dispersion using anomalous signal from a europium chloride derivative.|

  5. Effects of penicillin and erythromycin on adherence of invasive and noninvasive isolates of Streptococcus pyogenes to laminin.

    PubMed

    Šmitran, Aleksandra; Vuković, Dragana; Gajić, Ina; Marinković, Jelena; Ranin, Lazar

    2015-08-01

    This study investigated the possible relationship between the invasiveness of group A Streptococcus (GAS) strains and their abilities to adhere to laminin and assessed the effects of subinhibitory concentrations of penicillin and erythromycin on the ability of GAS to adhere to laminin. The adherence of noninvasive and highly invasive isolates of GAS to laminin was significantly higher than the adherence displayed by isolates of low invasiveness. Antibiotic treatment caused significant reductions in adherence to laminin in all three groups of strains. Penicillin was more successful in reducing the adherence abilities of the tested GAS strains than erythromycin.

  6. 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

  7. 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

  8. 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

  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. Flesh-eating Streptococcus pyogenes triggers the expression of receptor activator of nuclear factor-κB ligand.

    PubMed

    Matsui, Hidenori; Nakatani, Yuriko; Yoshida, Haruno; Takizawa, Asako; Takeuchi, Osamu; Øverby, Anders; Takahashi, Takashi; Murayama, Somay Y; Matsuo, Koichi

    2016-10-01

    Human CD46 is a receptor for the M protein of group A streptococcus (GAS). The emm1 GAS strain GAS472 was isolated from a patient suffering from streptococcal toxic shock-like syndrome. Human CD46-expressing transgenic (Tg) mice developed necrotizing fasciitis associated with osteoclast-mediated progressive and severe bone destruction in the hind paws 3 days after subcutaneous infection with 5 × 10(5) colony-forming units of GAS472. GAS472 infection induced expression of the receptor activator of nuclear factor-κB ligand (RANKL) while concomitantly reducing osteoprotegerin expression in the hind limb bones of CD46 Tg mice. Micro-computed tomography analysis of the bones suggested that GAS472 infection induced local bone erosion and systemic bone loss in CD46 Tg mice. Because treatment with monoclonal antibodies (mAbs) against mouse CD4(+) and CD8(+) T lymphocytes did not inhibit osteoclastogenesis, T lymphocyte-derived RANKL was not considered a major contributor to massive bone loss during GAS472 infection. However, immunohistochemical analysis of the hind limb bones showed that GAS472 infection stimulated RANKL production in various bone marrow cells, including fibroblast-like cells. Treatment with a mAb against mouse RANKL significantly inhibited osteoclast formation and bone resorption. These data suggest that increased expression of RANKL in heterogeneous bone marrow cells provoked bone destruction during GAS infection.

  11. 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

  12. Point-Counterpoint: A Nucleic Acid Amplification Test for Streptococcus pyogenes Should Replace Antigen Detection and Culture for Detection of Bacterial Pharyngitis.

    PubMed

    Pritt, Bobbi S; Patel, Robin; Kirn, Thomas J; Thomson, Richard B

    2016-10-01

    Nucleic acid amplification tests (NAATs) have frequently been the standard diagnostic approach when specific infectious agents are sought in a clinic specimen. They can be applied for specific agents such as S. pyogenes, or commercial multiplex NAATs for detection of a variety of pathogens in gastrointestinal, bloodstream, and respiratory infections may be used. NAATs are both rapid and sensitive. For many years, S. pyogenes testing algorithms used a rapid and specific group A streptococcal antigen test to screen throat specimens, followed, in some clinical settings, by a throat culture for S. pyogenes to increase the sensitivity of its detection. Now S. pyogenes NAATs are being used with increasing frequency. Given their accuracy, rapidity, and ease of use, should they replace antigen detection and culture for the detection of bacterial pharyngitis? Bobbi Pritt and Robin Patel of the Mayo Clinic, where S. pyogenes NAATs have been used for well over a decade with great success, will explain the advantages of this approach, while Richard (Tom) Thomson and Tom Kirn of the NorthShore University HealthSystem will discuss their concerns about this approach to diagnosing bacterial pharyngitis.

  13. 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

    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.

  14. In silico modeling of the type 2 IDI enzymes of Bacillus licheniformis, Pseudomonas stutzeri, Streptococcus pyogenes, and Staphylococcus aureus for virtual screening of potential inhibitors of this therapeutic target.

    PubMed

    Torktaz, Ibrahim; Shahbani Zahiri, Hossein; Akbari Noghabi, Kambiz

    2013-02-01

    Isopentenyl diphosphate isomerase is an essential enzyme in those living organisms such as pathogenic strains of Streptococcus and Staphylococcus genera which rely on the Mevalonate pathway for the production of isoprenoids. The pathogens contain type 2 IDI in contrast to human that contains type 1 IDI. Therefore, the type 2 IDI may be a potential target for the therapy of some infectious diseases. In the current study, a virtual screening by docking was performed among 2000 chemicals from CoCoCo library to find a specific inhibitor for type 2 IDIs. To this end, the structures of the type 2 IDIs of Bacillus licheniformis, Pseudomonas stutzeri, Streptococcus pyogenes, and Staphylococcus aureus were molded using comparative modeling and Hidden Markov Model (HMM) based prediction. The predicted models were evaluated based on Q-mean and Prosa score. Molegro Virtual Docker with MolDock scoring function was used for measuring the binding affinity of the found inhibitor to the active site of the models. Also the inhibition effect of the compound was virtually tested on the crystallography-solved structures of the Sulfolobus shibatae and Thermus thermophilus type 2 IDIs as well as the Escherichia coli type 1 IDI. Finally, the inhibition effect of the found inhibitor was virtually tested on the human type 1 IDI. Interestingly, the results suggest that the inhibitor efficiently binds to and inhibits the bacterial IDIs especially the type 2 IDIs of pathogens while it is not inhibiting the human IDI. PMID:23280415

  15. The Streptococcus pyogenes serotype M49 Nra-Ralp3 transcriptional regulatory network and its control of virulence factor expression from the novel eno ralp3 epf sagA pathogenicity region.

    PubMed

    Kreikemeyer, Bernd; Nakata, Masanobu; Köller, Thomas; Hildisch, Hendrikje; Kourakos, Vassilios; Standar, Kerstin; Kawabata, Shigetada; Glocker, Michael O; Podbielski, Andreas

    2007-12-01

    Many Streptococcus pyogenes (group A streptococcus [GAS]) virulence factor- and transcriptional regulator-encoding genes cluster together in discrete genomic regions. Nra is a central regulator of the FCT region. Previous studies exclusively described Nra as a transcriptional repressor of adhesin and toxin genes. Here transcriptome and proteome analysis of a serotype M49 GAS strain and an isogenic Nra mutant of this strain revealed the complete Nra regulon profile. Nra is active in all growth phases tested, with the largest regulon in the transition phase. Almost exclusively, virulence factor-encoding genes are repressed by Nra; these genes include the GAS pilus operon, the capsule synthesis operon, the cytolysin-mediated translocation system genes, all Mga region core virulence genes, and genes encoding other regulators, like the Ihk/Irr system, Rgg, and two additional RofA-like protein family regulators. Surprisingly, our experiments revealed that Nra additionally acts as a positive regulator, mostly for genes encoding proteins and enzymes with metabolic functions. Epidemiological investigations revealed strong genetic linkage of one particular Nra-repressed regulator, Ralp3 (SPy0735), with a gene encoding Epf (extracellular protein factor from Streptococcus suis). In a serotype-specific fashion, this ralp3 epf gene block is integrated, most likely via transposition, into the eno sagA virulence gene block, which is present in all GAS serotypes. In GAS serotypes M1, M4, M12, M28, and M49 this novel discrete genetic region is therefore designated the eno ralp3 epf sagA (ERES) pathogenicity region. Functional experiments showed that Epf is a novel GAS plasminogen-binding protein and revealed that Ralp3 activity counteracts Nra and MsmR regulatory activity. In addition to the Mga and FCT regions, the ERES region is the third discrete chromosomal pathogenicity region. All of these regions are transcriptionally linked, adding another level of complexity to the known

  16. 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.

  17. Liquid–liquid diffusion crystallization improves the X-ray diffraction of EndoS, an endo-β-N-acetyl­glucosaminidase from Streptococcus pyogenes with activity on human IgG

    PubMed Central

    Trastoy, Beatriz; Lomino, Joseph V.; Wang, Lai-Xi; Sundberg, Eric J.

    2013-01-01

    Endoglycosidase S (EndoS) is an enzyme secreted by Streptococcus pyogenes that specifically hydrolyzes the β-1,4-di-N-acetylchitobiose core glycan on immunoglobulin G (IgG) antibodies. One of the most common human pathogens and the cause of group A streptococcal infections, S. pyogenes secretes EndoS in order to evade the host immune system by rendering IgG effector mechanisms dysfunctional. On account of its specificity for IgG, EndoS has also been used extensively for chemoenzymatic synthesis of homogeneous IgG glycoprotein preparations and is being developed as a novel therapeutic for a wide range of autoimmune diseases. The structural basis of its enzymatic activity and substrate specificity, however, remains unknown. Here, the purification and crystallization of EndoS are reported. Using traditional hanging-drop and sitting-drop vapor-diffusion crystallization, crystals of EndoS were grown that diffracted to a maximum of 3.5 Å resolution but suffered from severe anisotropy, the data from which could only be reasonably processed to 7.5 Å resolution. When EndoS was crystallized by liquid–liquid diffusion, it was possible to grow crystals with a different space group to those obtained by vapor diffusion. Crystals of wild-type endoglycosidase and glycosynthase constructs of EndoS grown by liquid–liquid diffusion diffracted to 2.6 and 1.9 Å resolution, respectively, with a greatly diminished anisotropy. Despite extensive efforts, the failure to reproduce these liquid–liquid diffusion-grown crystals by vapor diffusion suggests that these crystallization methods each sample a distinct crystallization space. PMID:24316841

  18. Binding of complement inhibitor C4b-binding protein to a highly virulent Streptococcus pyogenes M1 strain is mediated by protein H and enhances adhesion to and invasion of endothelial cells.

    PubMed

    Ermert, David; Weckel, Antonin; Agarwal, Vaibhav; Frick, Inga-Maria; Björck, Lars; Blom, Anna M

    2013-11-01

    Streptococcus pyogenes AP1, a strain of the highly virulent M1 serotype, uses exclusively protein H to bind the complement inhibitor C4b-binding protein (C4BP). We found a strong correlation between the ability of AP1 and its isogenic mutants lacking protein H to inhibit opsonization with complement C3b and binding of C4BP. C4BP bound to immobilized protein H or AP1 bacteria retained its cofactor activity for degradation of (125)I-C4b. Furthermore, C4b deposited from serum onto AP1 bacterial surfaces was processed into C4c/C4d fragments, which did not occur on strains unable to bind C4BP. Recombinant C4BP mutants, which (i) lack certain CCP domains or (ii) have mutations in single aa as well as (iii) mutants with additional aa between different CCP domains were used to determine that the binding is mainly mediated by a patch of positively charged amino acid residues at the interface of domains CCP1 and CCP2. Using recombinant protein H fragments, we narrowed down the binding site to the N-terminal domain A. With a peptide microarray, we identified one single 18-amino acid-long peptide comprising residues 92-109, which specifically bound C4BP. Biacore was used to determine KD = 6 × 10(-7) M between protein H and a single subunit of C4BP. C4BP binding also correlated with elevated levels of adhesion and invasion to endothelial cells. Taken together, we identified the molecular basis of C4BP-protein H interaction and found that it is not only important for decreased opsonization but also for invasion of endothelial cells by S. pyogenes.

  19. Liquid-liquid diffusion crystallization improves the X-ray diffraction of EndoS, an endo-β-N-acetylglucosaminidase from Streptococcus pyogenes with activity on human IgG.

    PubMed

    Trastoy, Beatriz; Lomino, Joseph V; Wang, Lai Xi; Sundberg, Eric J

    2013-12-01

    Endoglycosidase S (EndoS) is an enzyme secreted by Streptococcus pyogenes that specifically hydrolyzes the β-1,4-di-N-acetylchitobiose core glycan on immunoglobulin G (IgG) antibodies. One of the most common human pathogens and the cause of group A streptococcal infections, S. pyogenes secretes EndoS in order to evade the host immune system by rendering IgG effector mechanisms dysfunctional. On account of its specificity for IgG, EndoS has also been used extensively for chemoenzymatic synthesis of homogeneous IgG glycoprotein preparations and is being developed as a novel therapeutic for a wide range of autoimmune diseases. The structural basis of its enzymatic activity and substrate specificity, however, remains unknown. Here, the purification and crystallization of EndoS are reported. Using traditional hanging-drop and sitting-drop vapor-diffusion crystallization, crystals of EndoS were grown that diffracted to a maximum of 3.5 Å resolution but suffered from severe anisotropy, the data from which could only be reasonably processed to 7.5 Å resolution. When EndoS was crystallized by liquid-liquid diffusion, it was possible to grow crystals with a different space group to those obtained by vapor diffusion. Crystals of wild-type endoglycosidase and glycosynthase constructs of EndoS grown by liquid-liquid diffusion diffracted to 2.6 and 1.9 Å resolution, respectively, with a greatly diminished anisotropy. Despite extensive efforts, the failure to reproduce these liquid-liquid diffusion-grown crystals by vapor diffusion suggests that these crystallization methods each sample a distinct crystallization space.

  20. 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

  1. Determination of As(III) and As(V) species in some natural water and food samples by solid-phase extraction on Streptococcus pyogenes immobilized on Sepabeads SP 70 and hydride generation atomic absorption spectrometry.

    PubMed

    Uluozlu, Ozgur Dogan; Tuzen, Mustafa; Mendil, Durali; Soylak, Mustafa

    2010-05-01

    The speciation of arsenic(III) and arsenic(V) by using Streptococcus pyogenes immobilized on Sepabeads SP 70 resin has been investigated with solid-phase extraction method. The arsenic levels were determined hydride generation atomic absorption spectrometry (HGAAS) in sample solutions. The procedure presented based on quantitative recoveries of As(III) as >95%. Also the As(V) recoveries were obtained as <5% using the presented method. After reduction of As(V) by using KI and ascorbic acid and waiting 1h later, the system was applied to determination of total arsenic. As(V) was found as the difference between the total As and As(III) content. Various experimental parameters such as pH, amount of microorganism, sample volume, etc. were investigated. The capacity of biosorbent for arsenic(III) was calculated as 7.3 mg/g. The preconcentration factor was found as 36. The relative standard deviation was calculated below 8%. Limit of detection was calculated as 13 ng/L. The validation of the presented procedure was tested by analysis of standard reference materials (NIST SRM 1568a Rice floor and GBW 07605 Tea) and obtained fairly compatible results. The procedure was also successfully applied to arsenic speciation and determination of some natural water and food samples.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. Group A Streptococcus endometritis following medical abortion.

    PubMed

    Gendron, Nicolas; Joubrel, Caroline; Nedellec, Sophie; Campagna, Jennifer; Agostini, Aubert; Doucet-Populaire, Florence; Casetta, Anne; Raymond, Josette; Poyart, Claire; Kernéis, Solen

    2014-07-01

    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

  7. 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

  8. Inhibition of group A streptococcus infection by carboxyfullerene.

    PubMed

    Tsao, N; Luh, T Y; Chou, C K; Wu, J J; Lin, Y S; Lei, H Y

    2001-06-01

    The effect of a water-soluble trimalonic acid derivative of fullerene, carboxyfullerene, against Streptococcus pyogenes infection was tested. Pretreatment with carboxyfullerene was able to protect mice from S. pyogenes infection in an air pouch model. S. pyogenes-induced death and skin injury were inhibited dose dependently by carboxyfullerene. Administration of carboxyfullerene via the peritoneum and air pouch at 3 h post-S. pyogenes infection was able to protect 33% of mice from death. Surveys of exudates of the air pouch of carboxyfullerene-treated mice revealed that survival of infiltrating neutrophils was prolonged and that the bacteria were eliminated as a result of enhanced bactericidal activity of the neutrophils. Furthermore, carboxyfullerene was able to directly inhibit in vitro growth of S. pyogenes. These data suggest that carboxyfullerene can be considered an antimicrobial agent for group A streptococcus infection. PMID:11353626

  9. [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

  10. 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...

  11. 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

  12. [THE DIAGNOSTIC APPROACHES TO VERIFICATION OF STREPTOCOCCUS INFECTION IN PATIENTS WITH INFECTIOUS MONONUCLEOSIS].

    PubMed

    Kim, M A; Labushkina, A V; Simovanian, E N; Kharseeva, G G

    2015-11-01

    The Rostovskii state medical university of Minzdrav of Russia, 344022 Rostov-on-Don, Russia The analysis is applied concerning significance of laboratory techniques of verification of streptococcus infection (bacteriological analysis, detection of anti-streptolysin O in pair serums) in 148 patients with infectious mononucleosis aged from 3 to 15 years. The content of anti-streptolysin O exceeded standard in 41 ± 4.8% of patients with concomitant in acute period and in 49.5 ± 4.9% during period of re-convalescence. This data differed from analogous indicator in patients with negative result of examination on streptococcus infection independently of period of disease (9.3 ± 2.8%). The exceeding of standard of anti-streptolysin O was detected more frequently (t ≥ 2, P ≥ 95%) in patients with isolation of Streptococcus pyogenes (56.9 ± 5.8%) than in patients with Streptococcus viridans (31.2 ± 6.5%). The concentration of anti-streptolysin 0 in patients with concomitant streptococcus infection varied within limits 200-1800 IE/ml. The minimal level of anti-streptolysin O (C = 200 IE/mI) was detected independently of type of isolated Streptococcus and period of disease. The high levels of anti-streptolysin O were observed exclusively in patients with isolation of Streptococcus pyogenes. In blood serum ofpatient with concomitant streptococcus infection (Streptococcus pyogenes + Streptococcus viridans) increasing of level of anti-streptolysin O was detected in dynamics of diseases from minimal (C = 200 IE/ ml) to moderately high (200 < C < 400 IE/mI). It is demonstrated that to identify streptococcus infection in patients with infectious mononucleosis the anamnesis data is to be considered. The complex bacteriological and serological examination ofpatients is to be implemented This is necessary for early detection ofpatients with streptococcus infection and decreasing risk of formation of streptococcus carrier state. PMID:26999869

  13. Immune response to Streptococcus pyogenes and the susceptibility to psoriasis.

    PubMed

    Muto, M; Fujikura, Y; Hamamoto, Y; Ichimiya, M; Ohmura, A; Sasazuki, T; Fukumoto, T; Asagami, C

    1996-05-01

    Monoclonal antibodies directed against type 12 Group A streptococcal cell wall antigens cross-react with nuclei and cytoplasm of cells from skin and synovium from controls, uninvolved skin of psoriatics and psoriatic plaques. Patients with psoriasis had high serum titres of antibody against the M12 (C-region) streptococcal antigen compared to controls. An abnormal immune response directed against a "self' antigen after initiation by Group A streptococcal infection may play an important role in the exacerbation or development of psoriasis.

  14. Streptococcus pyogenes sternoclavicular septic arthritis in a healthy adult.

    PubMed

    Savcic-Kos, Radmila M; Mali, Padmavati; Abraham, Ajit; Issa, Meltiady; Rangu, Venu; Nasser, Rana

    2014-12-01

    Sternoclavicular septic arthritis is a rare infection, accounting for approximately 1% of septic arthritis in the general population. Staphylococcus aureus is the predominant etiologic agent, and it usually occurs in relatively young adults with some type of predisposition to infection. We report, to the best of our knowledge, the first case of group A streptococcal, sternoclavicular arthritis in a previously healthy 62-year-old male patient. We present a detailed history and physical examination, with laboratory findings, imaging studies, cultures, and therapy.

  15. Streptococcus pyogenes Sternoclavicular Septic Arthritis in a Healthy Adult

    PubMed Central

    Savcic-Kos, Radmila M.; Mali, Padmavati; Abraham, Ajit; Issa, Meltiady; Rangu, Venu; Nasser, Rana

    2014-01-01

    Sternoclavicular septic arthritis is a rare infection, accounting for approximately 1% of septic arthritis in the general population. Staphylococcus aureus is the predominant etiologic agent, and it usually occurs in relatively young adults with some type of predisposition to infection. We report, to the best of our knowledge, the first case of group A streptococcal, sternoclavicular arthritis in a previously healthy 62-year-old male patient. We present a detailed history and physical examination, with laboratory findings, imaging studies, cultures, and therapy. PMID:24667224

  16. [Epidemiology of Streptococcus pyogenes infections in developing countries].

    PubMed

    Minodier, Ph; Laporte, R; Miramont, S

    2014-11-01

    Group A streptococcal (GAS) infections are frequent in developing countries but the epidemiology is incompletely known. In 2005, 90 % of symptomatic pharyngitis, 96 % of invasive diseases and 97 % of deaths due to GAS were observed in these countries. Clinical features of GAS invasive infections are identical to those reported in developed countries, but frequency and mortality are higher, as is the number of the different emm types involved. In the world, from 15.6 to 19.6 millions of persons are affected by rheumatic heart disease (282,000 new cases and 233,000-468,000 deaths per year). Incidence of acute post-streptococcal glomerulonephritis varies with time and location: in 2005, 472,000 new cases have been reported in the world (83 % in a developing country). World Heart Federation recently aimed at reducing the burden of rheumatic heart diseases by 25 % among < 25 years persons in 2025.

  17. Molecular Epidemiology and Genomics of Group A Streptococcus

    PubMed Central

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

    2014-01-01

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

  18. Streptococcus anginosus infections: crossing tissue planes.

    PubMed

    Sunwoo, Bernie Y; Miller, Wallace T

    2014-10-01

    Streptococcus anginosus has long been recognized to cause invasive pyogenic infections. This holds true for thoracic infections where S. anginosus has a propensity for abscess and empyema formation. Early diagnosis is important given the significant morbidity and mortality associated with thoracic S. anginosus infections. Yet, distinguishing thoracic S. anginosus clinically is difficult. We present three cases of thoracic S. anginosus that demonstrated radiographic extension across tissue planes, including the interlobar fissure, diaphragm, and chest wall. Few infectious etiologies are known to cross tissue planes. Accordingly, we propose S. anginosus be considered among the differential diagnosis of potential infectious etiologies causing radiographic extension across tissue planes.

  19. Anterior Debridement and Strut Graft with Pedicle Screw Fixation for Pyogenic Spondylitis

    PubMed Central

    Kim, Hak-Sun; Ahn, Chang-Soo; Lee, Dong-Hoon; Lee, Soon-Chul

    2007-01-01

    Study Design A retrospective study. Purpose We evaluated the results of the use of anterior debridement and interbody fusion followed by posterior spinal instrumentation. Overview of Literature An early diagnosis of pyogenic spondylitis is difficult to obtain. The disease can be treated with various surgical methods (such as anterior debridement and bone graft, anterior instrumentation, and posterior instrumentation). Methods This study included 20 patients who received anterior debridement and interbody fusion with strut bone graft followed by posterior spinal fusion for pyogenic spondylitis between 1996 and 2005. We analyzed the culture studies, the correction of the kyphotic angle, blood chemistry, the bony union period, and the amount of symptom relief. Results In terms of clinical symptoms relief, eight patients were grouped as "excellent", eleven patients as "good", and one patient as "fair". The vertebral body cultures were positive in 14 patients showing coagulase (-) streptococcus and S. aureus. The average times for normalization of the erythrocyte sedimentation rate and C-reactive protein level were 3.3 and 1.9 months, respectively. Four months was required for bony union. For complications, meralgia paresthetica was found in two cases. Conclusions Due to early ambulation and the correction of the kyphotic angle, anterior interbody fusion with strut bone graft and posterior instrumentation could be another favorable method for the treatment of pyogenic spondyulitis. PMID:20411131

  20. 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

  1. 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

  2. Streptococcus-Zebrafish Model of Bacterial Pathogenesis

    PubMed Central

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

    2002-01-01

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

  3. Giant Pyogenic Granuloma in a Patient with Chronic Lymphocytic Leukemia

    PubMed Central

    Plovanich, Molly; Tsibris, Hillary C.; Lian, Christine G.; Mostaghimi, Arash

    2014-01-01

    Pyogenic granuloma, also known as lobular capillary hemangioma, is a common benign vascular proliferative lesion that can present at any age on the skin or mucous membranes. Most lesions do not exceed 2 cm, but there are a handful of giant cutaneous pyogenic granulomas that have been reported, often in individuals with underlying immune dysfunction. Here, we report the first giant pyogenic granuloma in a patient with a hematological malignancy, chronic lymphocytic leukemia. PMID:25408651

  4. 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

  5. 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

  6. Pyogenic granuloma, port-wine stain and pregnancy.

    PubMed

    Rodins, Karl; Gramp, Dallas; James, Daniel; Kumar, Sandeep

    2011-11-01

    We present a novel case of pyogenic granuloma occurring within a port-wine stain in two sequential pregnancies at different sites. There was no history of precipitating events such as trauma. We discuss why a pyogenic granuloma may occur within a port-wine stain and how pregnancy may increase the likelihood of this occurring.

  7. 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.

  8. 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

  9. Concurrent Occurrence of Mucocele and Pyogenic Granuloma

    PubMed Central

    Kim, Jae-Hong; Park, Hwa-young; Hong, Seung Phil

    2011-01-01

    A mucocele is a common, benign lesion of the oral cavity that develops following the extravasation or retention of mucous from a major or minor salivary gland. A pyogenic granuloma (PG) is also a common, benign condition characterized by proliferating capillaries that affect the skin and mucous membranes. The concurrent occurrence of a mucocele and a PG lesion has rarely been reported in the medical literature. This case study reports such a finding in a 16-year-old patient who presented to our department. PMID:22028553

  10. Rapid antigen testing for group A Streptococcus by DNA probe.

    PubMed

    Heelan, J S; Wilbur, S; Depetris, G; Letourneau, C

    1996-02-01

    The Gen-probe group A Streptococcus direct test (GASD), a nucleic acid probe assay for detecting GAS from throat swabs, has recently been developed. The test uses an acridium ester-labeled DNA probe which is complementary to the rRNA of Streptococcus pyogenes. In this study, 318 single culturette throat swabs were tested by this method using culture as a "gold standard." After plating onto trypticase soy agar plates with 5% sheep blood, swabs were stored at 4 degrees C for no more than 72 h before the probe assay was performed. Our patient population consisted of symptomatic outpatients seen in the Memorial Hospital Emergency Department and in the Family Care Center. After discrepancy testing, sensitivity, specificity, and positive and negative predictive values were 91.4%, 97%, 91.4%, and 97%. The GASD is a rapid, easy-to-perform method for batch screening for streptococcal pharyngitis.

  11. PYOGENIC LIVER ABSCESS: DIAGNOSTIC AND THERAPEUTIC MANAGEMENT

    PubMed Central

    dos SANTOS-ROSA, Otto Mauro; LUNARDELLI, Henrique Simonsen; RIBEIRO-JUNIOR, Marcelo Augusto Fontenelle

    2016-01-01

    ABSTRACT Background: The pyogenic liver abscess has an incidence of 1.1/1,000 habitants. Mortality can reach 100%. The use of less invasive procedures diminish morbidity and hospital stay. Aim: Identify risk factors in patients who underwent percutaneous drainage guided by ultrasound as treatment. Method: Were analyzed 10 patients submitted to the method. Epidemiological characteristics, laboratory markers and imaging exams (ultrasound and CT) were evaluated. Results: The majority of the patients were men with mean age of 50 years old. Liver disease, alcoholism and biliary tract disease were the most common prodromes. Abdominal pain (90%), fever (70%) and jaundice (40%) were the most common clinical manifestations. Mortality of 20% was observed in this series. Hypoalbuminemia and days of hospitalization had a statistically significant positive association with death. Conclusion: The pyogenic liver abscess has subacute evolution which makes the diagnosis difficult. Image exams have high sensitivity in diagnosis, particularly computed tomography. Percutaneous drainage associated with antibiotic therapy is safe and effective therapeutic resource. PMID:27759785

  12. 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.

  13. 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

  14. Membrane cofactor protein (CD46) is a keratinocyte receptor for the M protein of the group A streptococcus.

    PubMed Central

    Okada, N; Liszewski, M K; Atkinson, J P; Caparon, M

    1995-01-01

    The pathogenic Gram-positive bacterium Streptococcus pyogenes (group A streptococcus) is the causative agent of numerous suppurative diseases of human skin. The M protein of S. pyogenes mediates the adherence of the bacterium to keratinocytes, the most numerous cell type in the epidermis. In this study, we have constructed and analyzed a series of mutant M proteins and have shown that the C repeat domain of the M molecule is responsible for cell recognition. The binding of factor H, a serum regulator of complement activation, to the C repeat region of M protein blocked bacterial adherence. Factor H is a member of a large family of complement regulatory proteins that share a homologous structural motif termed the short consensus repeat. Membrane cofactor protein (MCP), or CD46, is a short consensus repeat-containing protein found on the surface of keratinocytes, and purified MCP could competitively inhibit the adherence of S. pyogenes to these cells. Furthermore, the M protein was found to bind directly to MCP, whereas mutant M proteins that lacked the C repeat domain did not bind MCP, suggesting that recognition of MCP plays an important role in the ability of the streptococcus to adhere to keratinocytes. Images Fig. 1 Fig. 2 Fig. 3 PMID:7708671

  15. Genomic Evidence for the Evolution of Streptococcus equi: Host Restriction, Increased Virulence, and Genetic Exchange with Human Pathogens

    PubMed Central

    Paillot, Romain; Steward, Karen F.; Webb, Katy; Ainslie, Fern; Jourdan, Thibaud; Bason, Nathalie C.; Holroyd, Nancy E.; Mungall, Karen; Quail, Michael A.; Sanders, Mandy; Simmonds, Mark; Willey, David; Brooks, Karen; Aanensen, David M.; Spratt, Brian G.; Jolley, Keith A.; Maiden, Martin C. J.; Kehoe, Michael; Chanter, Neil; Bentley, Stephen D.; Robinson, Carl; Maskell, Duncan J.; Parkhill, Julian; Waller, Andrew S.

    2009-01-01

    The continued evolution of bacterial pathogens has major implications for both human and animal disease, but the exchange of genetic material between host-restricted pathogens is rarely considered. Streptococcus equi subspecies equi (S. equi) is a host-restricted pathogen of horses that has evolved from the zoonotic pathogen Streptococcus equi subspecies zooepidemicus (S. zooepidemicus). These pathogens share approximately 80% genome sequence identity with the important human pathogen Streptococcus pyogenes. We sequenced and compared the genomes of S. equi 4047 and S. zooepidemicus H70 and screened S. equi and S. zooepidemicus strains from around the world to uncover evidence of the genetic events that have shaped the evolution of the S. equi genome and led to its emergence as a host-restricted pathogen. Our analysis provides evidence of functional loss due to mutation and deletion, coupled with pathogenic specialization through the acquisition of bacteriophage encoding a phospholipase A2 toxin, and four superantigens, and an integrative conjugative element carrying a novel iron acquisition system with similarity to the high pathogenicity island of Yersinia pestis. We also highlight that S. equi, S. zooepidemicus, and S. pyogenes share a common phage pool that enhances cross-species pathogen evolution. We conclude that the complex interplay of functional loss, pathogenic specialization, and genetic exchange between S. equi, S. zooepidemicus, and S. pyogenes continues to influence the evolution of these important streptococci. PMID:19325880

  16. 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

  17. Trueperella pyogenes and Escherichia coli as an etiological factor of endometritis in cows and the susceptibility of these bacteria to selected antibiotics.

    PubMed

    Brodzki, P; Bochniarz, M; Brodzki, A; Wrona, Z; Wawron, W

    2014-01-01

    The aim of this study was to determine the percentage of participation of particular species of microorganisms, isolated from the uterus of cows with endometritis and from cows without inflammatory lesions of the uterus, in the same postpartum period. The aim of the study was also to examine how long after parturition non-treated endometritis persists. Moreover, antibiotic susceptibility tests were carried out of the bacterial isolates dominating in the uterus. Forty cows were included in the study: 20 cows with endometritis (experimental group) and 20 cows without any inflammatory condition of the uterus (control group). The material for cytological and bacteriological tests was collected on the 5th, 26th, 40th and 60th day after parturition, using an intrauterine brush adapted for cows. The total number of collected isolates was 149, including 120 isolates from the uterus of cows with endometritis and 29 isolates from the uterus of cows without endometritis. The following species of microorganisms were isolated from the material collected from cows with endometritis: T. pyogenes (49.2%), E.coli (22.5%), F. necrophorum (11.7%), Staphylococcus sp. (6.7%), B. melaninogenicus (5.8%), and Streptococcus sp. (4.1%). The participation percentage of particular species of bacteria in the material collected from the uterus of cows without endometritis was as follows: T. pyogenes (27.6%), E.coli (24.2%), Staphylococcus sp. (20.7%), Streptococcus sp. (20.7%), B. melaninogenicus (3.4%) and F. necrophorum (3.4%). The highest percentage of T. pyogenes isolates was susceptible to ceftiofur (89.6%); cefoperazone (85.1%) and amoxicillin combined with clavulanic acid (79.1%). E. coli isolates were most susceptible to amoxicillin combined with clavulanic acid (100%), cefoperazone (94.1%) and oxytetracycline (82.3%). PMID:25638979

  18. 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

  19. 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

  20. 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

  1. 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

  2. Localisation of /sup 125/I-labelled streptolysin O of Streptococcus pyogenes in mice

    SciTech Connect

    Shibl, A.M.; Abdullah, M.E.; Al-Sowaygh, I.A.

    1981-01-01

    The fate of /sup 125/I-labelled Streptolysin O injected intravenously into mice was studied. After 2 hours only 5% of the injected label remained in the blood. The highest concentration of radioactivity was consistently observed in the liver and kidneys. The labelled toxin was degraded in the liver but its greatest toxic effect took place in the kidneys.

  3. 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

  4. Genetic and phenotypic characterization of resistance to macrolides in Streptococcus pyogenes from Argentina.

    PubMed

    Martínez, Silvia; Amoroso, Ana M; Famiglietti, Angela; de Mier, Carmen; Vay, Carlos; Gutkind, Gabriel O

    2004-01-01

    Five hundred and seventy-eight strains of group A streptococci (GAS) isolated mostly from paediatric pharyngeal swabs were tested to evaluate their susceptibility to erythromycin. Resistant strains were then tested for their MICs to erythromycin and clindamycin, their phenotype of resistance to macrolides-lincosamides-streptogramin (MLS(B)) and for the presence of macrolide resistance genes. The rate of resistance to erythromycin was 8.2%. Constitutive, inducible and M phenotypes of resistance were detected in 2.1, 2.1 and 95.8% of resistant strains, respectively. All M phenotypes harboured the mefA gene, whereas constitutive and inducible phenotypes had ermB and ermTR genes, respectively.

  5. Antiphagocytic Function of an IgG Glycosyl Hydrolase from Streptococcus equi subsp. equi and Its Use as a Vaccine Component

    PubMed Central

    Flock, Margareta; Frykberg, Lars; Sköld, Markus; Guss, Bengt

    2012-01-01

    EndoSe from Streptococcus equi subsp. equi is an enzyme hydrolyzing glycosyl groups on IgG, analogous to EndoS from Streptococcus pyogenes. We here show that the activity of EndoSe leads to an antiphagocytic function and may thus be a contributory factor to immune evasion of S. equi. Despite the damaging effect that EndoSe has on IgG, antibodies against EndoSe can neutralize its function. Antibodies against EndoSe restored the opsonic activity of specific opsonizing antibodies. Mice infected with either S. equi subsp. equi or subsp. zooepidemicus or S. pyogenes could be protected by vaccination with EndoSe. It is speculated that EndoSe could be a suitable vaccine candidate against streptococcal infections. PMID:22615244

  6. 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

  7. 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

  8. The Histopathological Spectrum of Pyogenic Granuloma: A Case Series.

    PubMed

    Marla, Vinay; Shrestha, Ashish; Goel, Khushboo; 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

  9. 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

  10. 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

  11. 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

  12. Relatedness of Streptococcus canis from canine streptococcal toxic shock syndrome and necrotizing fasciitis.

    PubMed Central

    DeWinter, L M; Prescott, J F

    1999-01-01

    The emergence of streptococcal toxic shock syndrome (STSS) and necrotizing fasciitis (NF) in dogs caused by Streptococcus canis has been reported by our laboratory. Since clonal expansion is thought to be partially responsible for the spread of invasive strains of Streptococcus pyogenes in humans, the relatedness of 15 isolates of S. canis from canine STSS and/or NF was examined using pulsed field gel electrophoresis and biotyping; production of proteases and of a CAMP-like reaction were also examined. Only 2 of the 15 STSS and/or NF isolates were clonally related, suggesting that the emergence of canine STSS/NF is not the result of clonal expansion of one or more highly virulent strains of S. canis. All of the isolates produced proteases and demonstrated a CAMP-like reaction, which appear to be additional characteristics of S. canis. PMID:10369564

  13. 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.

  14. Streptococcus bovis meningitis and hemorrhoids.

    PubMed

    Smith, Adam Hewitt; Sra, Harminder K; Bawa, Sandeep; Stevens, Richard

    2010-07-01

    We report a case of Streptococcus bovis (Streptococcus gallolyticus subsp. pasteurianus) meningitis, a rare cause of central nervous system (CNS) infection in an adult, and comment on the importance of investigation of the lower gastrointestinal tract to identify a portal of entry in cases of systemic Streptococcus bovis infection. PMID:20421434

  15. 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

  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.

  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. 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

  19. 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

  20. 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

  1. 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.

  2. Fibronectin-binding protein of Streptococcus equi subsp. zooepidemicus.

    PubMed Central

    Lindmark, H; Jacobsson, K; Frykberg, L; Guss, B

    1996-01-01

    By screening a genomic lambda library of Streptococcus equi subsp. zooepidemicus, we have cloned and sequenced a gene, termed fnz, encoding a fibronectin (Fn)-binding protein called FNZ. On the basis of the deduced amino acid sequence of FNZ, the mature protein has a molecular mass of approximately 61 kDa. Analysis of FNZ reveals a structural organization similar to that of other cell surface proteins from streptococci and staphylococci. The Fn-binding activity is localized to two domains in the C-terminal part of FNZ. One domain is composed of five repeats, which contain a motif similar to what has earlier been found in other Fn-binding proteins in streptococci and staphylococci. The first and second repeats are separated by a short stretch of amino acids, including the motif LAGESGET, which is an important part of the second Fn-binding domain. This motif is also present in an Fn-binding domain (UR) in protein F of Streptococcus pyogenes. A fusion protein covering the Fn-binding domain of FNZ inhibits the binding of the 29-kDa N-terminal fragment of Fn to cells of various streptococcal species as well as to Staphylococcus aureus. PMID:8926060

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

    PubMed Central

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

    2015-01-01

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

  4. 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

  5. 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

  6. 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

  7. Two Novel Superantigens Found in Both Group A and Group C Streptococcus

    PubMed Central

    Proft, Thomas; Webb, Phillip D.; Handley, Vanessa; Fraser, John D.

    2003-01-01

    Two novel streptococcal superantigen genes (speLSe and speMSe) were identified from the Streptococcus equi genome database at the Sanger Center. Genotyping of 8 S. equi isolates and 40 Streptococcus pyogenes isolates resulted in the detection of the orthologous genes speL and speM in a restricted number of S. pyogenes isolates (15 and 5%, respectively). Surprisingly, the novel superantigen genes could not be found in any of the analyzed S. equi isolates. The results suggest that both genes are located on a mobile element that enables gene transfer between individual isolates and between streptococci from different Lancefield groups. S. equi pyrogenic exotoxin L (SPE-LSe)/streptococcal pyrogenic exotoxin L (SPE-L) and SPE-MSe/SPE-M are most closely related to SMEZ, SPE-C, SPE-G, and SPE-J, but build a separate branch within this group. Recombinant SPE-L (rSPE-L) and rSPE-M were highly mitogenic for human peripheral blood lymphocytes, with half-maximum responses at 1 and 10 pg/ml, respectively. The results from competitive binding experiments suggest that both proteins bind major histocompatibility complex class II at the β-chain, but not at the α-chain. The most common targets for both toxins were human Vβ1.1 expressing T cells. Seroconversion against SPE-L and SPE-M was observed in healthy blood donors, suggesting that the toxins are expressed in vivo. Interestingly, the speL gene is highly associated with S. pyogenes M89, a serotype that is linked to acute rheumatic fever in New Zealand. PMID:12595453

  8. 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

  9. Serologic studies of Streptococcus intermedius, Streptococcus constellatus, and Streptococcus morbillorum by crossed immunoelectrophoresis.

    PubMed

    Coleman, R M; Lambe, D W

    1979-07-01

    A reference antigen-antibody system for Streptococcus intermedius, Streptococcus constellatus, and Streptococcus morbillorum was established with crossed immunoelectrophoresis. A comparison of S. intermedius, S. constellatus, and S. morbillorum with crossed immunoelectrophoresis and crossed immunoelectrophoresis with intermediate gel indicated that S. intermedius and S. constellatus are closely related antigenically with as many as six common cytoplasmic antigens. S. morbillorum was antigenically more distinct; antiserum of one strain of S. morbillorum was monospecific, indicating that specific serogroups of S. morbillorum exist. Crossed immunoelectrophoresis and tandem crossed immunoelectrophoresis revealed that S. intermedius, S. constellatus, and S. morbillorum also share some common antigens with Streptococcus sanguis and Streptococcus mitis, but S. intermedius, S. constellatus, and S. morbillorum are antigenically distinct from Streptococcus mutans and Streptococcus bovis.

  10. Acute guttate psoriasis patients have positive streptococcus hemolyticus throat cultures and elevated antistreptococcal M6 protein titers.

    PubMed

    Zhao, Guang; Feng, Xiaoling; Na, Aihua; Yongqiang, Jiang; Cai, Qing; Kong, Jian; Ma, Huijun

    2005-02-01

    To further study the role of Streptococci hemolyticus infection and streptococcal M6 protein in the pathogenesis of acute guttate psoriasis, streptococcal cultures were taken from the throats of 68 patients with acute guttate psoriasis. PCR technique was applied to detect M6 protein encoding DNA from those cultured streptococci. Pure M6 protein was obtained by Sephacry/S-200HR and Mono-Q chromatography from proliferated Streptococcus hemolyticus. Antistreptococcal M6 protein titers were measured in the serum of patients with acute guttate psoriasis, plaque psoriasis and healthy controls by ELISA. A high incidence of Streptococcus hemolyticus culture was observed in the guttate psoriatic group compared with the plaque psoriasis and control groups. Fourteen strains of Streptococcus hemolyticus were cultured from the throats of 68 acute guttate psoriasis patients. Of these, 5 strains contain DNA encoding the M6 protein gene as confirmed by PCR technique. More than 85% purification of M6 protein was obtained from Streptococcus pyogenes. Applying our pure M6 protein with the ELISA methods, we found that the titer of antistreptococcal M6 protein was significantly higher in the serum of guttate psoriasis patients than in the control or plaque psoriasis groups (P < 0.01). We verified that patients of acute guttate psoriasis have a high incidence of Streptococcus hemolyticus in their throats and raised titers of antistreptococcal M6 protein in their sera.

  11. 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

  12. 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

  13. An unusual presentation of pyogenic granuloma of the lower lip.

    PubMed

    Asha, V; Dhanya, M; Patil, Bharati A; Revanna, G

    2014-10-01

    Exophytic growth of the oral cavity often presents a diagnostic challenge because a diverse group of the pathologic process can produce such lesions. Inflammatory hyperplasia is one of the important etiology behind the exophytic growths of the oral cavity. The pyogenic granuloma (PG) is the most common type of inflammatory hyperplasia found in the oral cavity especially in the gingiva. Extragingival occurrence of PG is very rare. This case report has described an extragingival PG which occurred on the lower labial mucosa in a 54-year-old male patient.

  14. Periungual Pyogenic Granuloma: The Importance of the Medical History.

    PubMed

    Alessandrini, Aurora; Bruni, Francesca; Starace, Michela; Piraccini, Bianca Maria

    2016-05-01

    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

  15. 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

  16. 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

  17. 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

  18. Management of oral pyogenic granuloma with sodium tetra decyl sulphate. A case series.

    PubMed

    Samatha, Y; Reddy, T Harshavardhan; Jyothirrmai; Ravikiran, A; Sankar, A J Sai

    2013-01-01

    Pyogenic granuloma, or granuloma pyogenicum, is a common, tumor-like growth of the oral cavity or skin that is considered to be an exaggerated, localized connective tissue reaction to a minor injury or irritation. A total of five clinical cases of oral pyogenic granuloma were randomly selected in the age group between 26 and 41 years. All these cases were treated with sodium tetra decyl sulphate and examined for regression and reccurrence of the lesion for six months. Various treatment modalities consist of conservative surgical excision, cryosurgery, laser surgery and sclerotherapy. Sclerotherapy with sodium tetra decyl sulphate is a relatively simple and effective method for treating oral pyogenic granuloma.

  19. Streptococcus dysgalactiae subsp. equisimilis Isolated From Infections in Dogs and Humans: Are Current Subspecies Identification Criteria accurate?

    PubMed

    Ciszewski, Marcin; Zegarski, Kamil; Szewczyk, Eligia M

    2016-11-01

    Streptococcus dysgalactiae is a pyogenic species pathogenic both for humans and animals. Until recently, it has been considered an exclusive animal pathogen causing infections in wild as well as domestic animals. Currently, human infections are being reported with increasing frequency, and their clinical picture is often similar to the ones caused by Streptococcus pyogenes. Due to the fact that S. dysgalactiae is a heterogeneous species, it was divided into two subspecies: S. dysgalactiae subsp. equisimilis (SDSE) and S. dysgalactiae subsp. dysgalactiae (SDSD). The first differentiation criterion, described in 1996, was based on strain isolation source. Currently applied criteria, published in 1998, are based on hemolysis type and Lancefield group classification. In this study, we compared subspecies identification results for 36 strains isolated from clinical cases both in humans and animals. Species differentiation was based on two previously described criteria as well as MALDI-TOF and genetic analyses: RISA and 16S rRNA genes sequencing. Antimicrobial susceptibility profiles were also determined according to CLSI guidelines. The results presented in our study suggest that the subspecies differentiation criteria previously described in the above two literature positions seem to be inaccurate in analyzed group of strains, the hemolysis type on blood agar, and Lancefield classification should not be here longer considered as criteria in subspecies identification. The antimicrobial susceptibility tests indicate emerging of multiresistant human SDSE strains resistant also to vancomycin, linezolid and tigecycline, which might pose a substantial problem in treatment. PMID:27502064

  20. Laser: A Powerful Tool for Treatment of Pyogenic Granuloma

    PubMed Central

    Rai, Shalu; Kaur, Mandeep; Bhatnagar, Puneet

    2011-01-01

    Lasers have opened a new door for the treatment of various disorders. Treatment of soft tissue intraoral mucosal growth by laser has profound effect on the patient acceptability taking the functional and aesthetic factor into consideration. The patient is able to get the outdoor treatment without the phobia of local anaesthetic and is out of the clinic in few minutes in contrast to the traditional method of surgical excision. Very few cases have been reported in literature regarding treatment of mucosal growth by soft tissue lasers. We present a case of recurrent pyogenic granuloma in a patient treated with an alternative approach, that is, diode laser, without the use of anaesthesia, sutures, anti-inflammatory drugs, or analgesics. The diagnosis of this lesion is equally important for correct treatment planning. PMID:21976910

  1. [Current concepts in the management of pyogenic brain abscesses].

    PubMed

    Badreddine, Kilani; Lamia, Ammari; Emna, Mnif; Hanene, Tiouiri; Fakher, Kanoun; Ahmed, Goubontini; Chahib, Marrakchi; Faycel, Zouiten; Taoufik, Ben Chaabène

    2005-07-01

    Brain abscesses are severe infections with lethal outcome in the case of delay in diagnosis and treatment. The authors report their experience about 30 patients with pyogenic brain abscesses treated between 1989 and 2000. The goal of the study is to analyse epidemiological, clinical and therapeutic aspects of this disease. The sex ratio (M:W) was 2,3 and the mean age was 34 years. Predisposing factors were sepsis of adjacent organs (53%) and bacteremia (30%). The clinical manifestations were: fever (83%), headaches (90%) and focal neurologic signs (57%). CT-scan findings were single lesions in 80% of cases. CT-scan showed a deep ring-enhancing lesion with surrounding edema in 77% of cases. Bacteriological agents in 13 cases (43%) were: 4 Staphylococcus aureus, 2 Neisseria meningitidis and 7 negative Gram bacilli. Medical treatment alone was in 77% of cases; seven patients benefited from medical and neurosurgical approaches. Death occured in 10% of cases.

  2. Small plasmids in Streptococcus dysgalactiae subsp. equisimilis isolated from human infections in southern India and sequence analysis of two novel plasmids.

    PubMed

    Bergmann, René; Nitsche-Schmitz, D Patric

    2015-05-01

    Small plasmids are frequently found in S. pyogenes isolates from human infections in India. Streptococcus dysgalactiae subsp. equisimilis (SDSE) is a streptococcal subspecies that is genetically similar to S. pyogenes and has a similar ecology. Therefore, we determined the distribution of small plasmids in a collection of 254 SDSE isolates, comprising 44 different emm-types and emm non-typable strains, from southern India, utilizing an established PCR based method. Briefly, 1.2% (n=3) of the isolates were positive for repA (encoding the replication initiation protein A) and 1.6% (n=4) were repB positive (encoding the replication initiation protein B). One isolate (G315) showed a co-detection of repB and dysA (encoding the bacteriocin dysgalacticin) which is characteristic for previously described pDN281/pW2580-like plasmids, observed in SDSE and S. pyogenes. The remaining plasmid bearing isolates showed no characteristic co-detection of known plasmid-associated genes. Thus, plasmids pG271 and pG279, representatives for repB and repA harboring plasmids, respectively, were analyzed. The plasmids pG271 and pG279 could be assigned to the pMV158 and the pC194/pUB110 family of rolling-circle plasmids, respectively. Like the characterized small native plasmids of S. pyogenes from India, the SDSE plasmids discovered and described in this study did not carry any of the known antibiotic resistance genes. SDSE bore less of the investigated small native plasmids that were distinct from the small native plasmids of S. pyogenes of the same geographic region. This indicates a low rate of lateral transfer of these genetic elements between these two related streptococcal species.

  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. 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

  5. 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

  6. 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

  7. Characterization of a Streptococcus suis tet(O/W/32/O)-carrying element transferable to major streptococcal pathogens.

    PubMed

    Palmieri, Claudio; Magi, Gloria; Mingoia, Marina; Bagnarelli, Patrizia; Ripa, Sandro; Varaldo, Pietro E; Facinelli, Bruna

    2012-09-01

    Mosaic tetracycline resistance determinants are a recently discovered class of hybrids of ribosomal protection tet genes. They may show different patterns of mosaicism, but their final size has remained unaltered. Initially thought to be confined to a small group of anaerobic bacteria, mosaic tet genes were then found to be widespread. In the genus Streptococcus, a mosaic tet gene [tet(O/W/32/O)] was first discovered in Streptococcus suis, an emerging drug-resistant pig and human pathogen. In this study, we report the molecular characterization of a tet(O/W/32/O) gene-carrying mobile element from an S. suis isolate. tet(O/W/32/O) was detected, in tandem with tet(40), in a circular 14,741-bp genetic element (39.1% G+C; 17 open reading frames [ORFs] identified). The novel element, which we designated 15K, also carried the macrolide resistance determinant erm(B) and an aminoglycoside resistance four-gene cluster including aadE (streptomycin) and aphA (kanamycin). 15K appeared to be an unstable genetic element that, in the absence of recombinases, is capable of undergoing spontaneous excision under standard growth conditions. In the integrated form, 15K was found inside a 54,879-bp integrative and conjugative element (ICE) (50.5% G+C; 55 ORFs), which we designated ICESsu32457. An ∼1.3-kb segment that apparently served as the att site for excision of the unstable 15K element was identified. The novel ICE was transferable at high frequency to recipients from pathogenic Streptococcus species (S. suis, Streptococcus pyogenes, Streptococcus pneumoniae, and Streptococcus agalactiae), suggesting that the multiresistance 15K element can successfully spread within streptococcal populations.

  8. 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.

  9. Impact of identification of Streptococcus dysgalactiae subspecies equisimilis from throat cultures in an adult population.

    PubMed

    Harrington, Amanda T; Clarridge, Jill E

    2013-05-01

    Streptococcus dysgalactiae subspecies equisimilis (SDSE) are isolated from the throat of patients with pharyngitis, although the clinical significance remains debated. We sought to determine the incidence and association with pharyngitis of SDSE in an adult veteran population. Organisms were phenotypically identified to subspecies and Lancefield group, with selective 16S rRNA gene sequencing. From 833 throat cultures, the overall frequency of SDSE was 3.4% (64% group C and 36% group G) as compared to 8.6% for S. pyogenes (GAS). SDSE was described as a large colony in only 29% of the original culture evaluations by bench technologists, and clinical symptoms were similar for GAS and SDSE. Laboratory algorithms that are limited to identification of only GAS or are based on Lancefield group or visual identification of "large-colony type" β hemolytic Lancefield group C and G streptococci may be missing or misidentifying SDSE along with Anginosus group streptococci.

  10. Molecular Characterization of Invasive Streptococcus dysgalactiae subsp. equisimilis, Japan.

    PubMed

    Wajima, Takeaki; Morozumi, Miyuki; Hanada, Shigeo; Sunaoshi, Katsuhiko; Chiba, Naoko; Iwata, Satoshi; Ubukata, Kimiko

    2016-02-01

    We collected β-hemolytic streptococci (1,611 isolates) from patients with invasive streptococcal infections in Japan during April 2010-March 2013. Streptococcus dysgalactiae subsp. equisimilis (SDSE) was most common (n = 693); 99% of patients with SDSE infections were elderly (mean age 75 years, SD ±15 years). We aimed to clarify molecular and epidemiologic characteristics of SDSE isolates and features of patient infections. Bacteremia with no identified focus of origin and cellulitis were the most prevalent manifestations; otherwise, clinical manifestations resembled those of S. pyogenes infections. Clinical manifestations also differed by patient's age. SDSE isolates were classified into 34 emm types; stG6792 was most prevalent (27.1%), followed by stG485 and stG245. Mortality rates did not differ according to emm types. Multilocus sequence typing identified 46 sequence types and 12 novel types. Types possessing macrolide- and quinolone-resistance genes were 18.4% and 2.6%, respectively; none showed β-lactam resistance. Among aging populations, invasive SDSE infections are an increasing risk.

  11. Effects of Suilysin on Streptococcus suis-Induced Platelet Aggregation

    PubMed Central

    Zhang, Shengwei; Wang, Junping; Chen, Shaolong; Yin, Jiye; Pan, Zhiyuan; Liu, Keke; Li, Lin; Zheng, Yuling; Yuan, Yuan; Jiang, Yongqiang

    2016-01-01

    Blood platelets play important roles during pathological thrombocytopenia in streptococcal toxic shock syndrome (STSS). Streptococcus suis (S. suis) an emerging human pathogen, can cause STSS similarly to S. pyogenes. However, S. suis interactions with platelets are poorly understood. Here, we found that suilysin (SLY), different from other bacterial cholesterol-dependent cytolysins (CDCs), was the sole stimulus that induced platelet aggregation. Furthermore, the inside-out activation of GPIIb/IIIa of platelets mediated SLY-induced platelet aggregation. This process was triggered by Ca2+ influx that depend on the pore forming on platelets by SLY. Additionally, although SLY induced α-granule release occurred via the MLCK-dependent pathway, PLC-β-IP3/DAG-MLCK and Rho-ROCK-MLCK signaling were not involved in SLY-induced platelet aggregation. Interestingly, the pore dependent Ca2+ influx was also found to participate in the induction of platelet aggregation with pneumolysin (PLY) and streptolysin O (SLO), two other CDCs. It is possible that the CDC-mediated platelet aggregation we observed in S. suis is a similar response mechanism to that used by a wide range of bacteria. These findings might lead to the discovery of potential therapeutic targets for S. suis-associated STSS. PMID:27800304

  12. 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

  13. 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

  14. Oral Pyogenic Granuloma Associated With a Dental Implant Treated With an Er:YAG Laser: A Case Report.

    PubMed

    Kaya, Alper; Ugurlu, Faysal; Basel, Bilal; Sener, Cem B

    2015-12-01

    A pyogenic granuloma is a tumorlike proliferation that occurs slightly more often in females, frequently involving the gingiva in the maxillary region. Clinically, it presents as a sessile or pedunculated exophytic mass with a smooth or lobulated surface, which tends to bleed easily. Its color can range from pink to dark red. The most common treatment is surgical excision. This case report presents a pyogenic granuloma that formed around an implant 7 years after its insertion. Pyogenic granulomas associated with dental implants are extremely rare; this is the fourth reported case and the first case of pyogenic granuloma to be treated with an Er:YAG laser.

  15. 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

  16. 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

  17. Phenotypic characteristics and virulence genotypes of Trueperella (Arcanobacterium) pyogenes strains isolated from European bison (Bison bonasus).

    PubMed

    Rzewuska, Magdalena; Stefańska, Ilona; Osińska, Barbara; Kizerwetter-Świda, Magdalena; Chrobak, Dorota; Kaba, Jarosław; Bielecki, Wojciech

    2012-11-01

    Trueperella (Arcanobacterium) pyogenes is an opportunistic animal pathogen, which in European bison is associated with different suppurative infections mainly of the urogenital tract. Little is known about the virulence of this bacterium and about the pathogenesis of infections. The main objective of this study was to determine phenotypic properties and virulence genotypes of the twenty-five T. pyogenes strains isolated from lesions in various tissues of free-living European bison. Classical bacteriological methods were used for phenotypic characterization. Genes encoding seven known and putative virulence factors of T. pyogenes were detected by PCR technique. Analysis of 16S rDNA partial sequences was performed to establish phylogenetic relationships of the isolated strains. All isolates showed typical morphological features of T. pyogenes and variable biochemical activity. Most of them displayed a strong positive effect in synergistic CAMP test. For all isolates the 16S rRNA gene partial sequence was identical to that of the T. pyogenes reference strain. All isolates carried the plo and fimA genes, while the nanH, nanP, cbpA, fimC and fimG genes were present in 40, 44, 12, 88 and 24% of the isolates, respectively. The T. pyogenes strains isolated from European bison represented various phenotypes and virulence genotypes, but there was no association between the investigated properties of the bacteria and the type of anatomopathological lesions from which they were isolated. These results indicate that the studied virulence factors of T. pyogenes are not significant determinants of the localization and type of infection caused by this bacterium.

  18. Streptococcus sp. and Staphylococcus aureus isolates from patients with psoriasis possess genes that code for toxins (superantigens): clinical and therapeutic implications.

    PubMed

    El Ferezli, Jessica; Jenbazian, Lori; Rubeiz, Nelly; Kibbi, Abdul-Ghani; Zaynoun, Shukrallah; Abdelnoor, Alexander M

    2008-01-01

    Superantigens are powerful T lymphocyte-stimulating agents that are believed to contribute to the pathogenesis of certain diseases such as psoriasis. Toxins produced by Streptococcus pyogenes and Staphylococcus aureus are superantigens. The aim of this study was to detect genes that code for superantigens in Streptococcus and Staphylococcus aureus isolates from psoriatic patients. Primers to amplify streptococcal pyrogenic exotoxin A, B, and C and streptolysin O genes and staphylococcal enterotoxin A, B, C, and D genes were used. Streptococcal exotoxin B was detected in five streptococcal isolates. Staphyloccocus aureus enterotoxin A and/or C genes were detected in nine S. aureus isolates. Isolates from 13 of 22 patients possesed gene(s) that code for toxin(s) (superantigens). These results might support the role of superantigens in the exacerbation of psoriasis.

  19. 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

  20. Associations of macrolide and fluoroquinolone resistance with molecular typing in Streptococcus pyogenes from invasive infections, 2010-2012.

    PubMed

    Wajima, Takeaki; Morozumi, Miyuki; Chiba, Naoko; Shouji, Michi; Iwata, Satoshi; Sakata, Hiroshi; Ubukata, Kimiko

    2013-11-01

    In this study, the relationship between emm type and antibiotic resistance in 283 invasive group A streptococcal strains collected during surveillance from 2010 to 2012 was analysed. Strains were characterised by emm typing, multilocus sequence typing and antimicrobial susceptibility. Resistance rates for macrolide antibiotics conferred by mef(A), erm(A) or erm(B) were high (54.4%). The most prevalent (40.3%) macrolide resistance mediated by mef(A) was present in 92.2% of emm1 strains. It was found that 53.3% of emm12 strains and 91.7% of emm28 strains had erm(A) or erm(B) genes. Intermediate resistance to fluoroquinolones caused by a mutation in parC was found in 14.1% of strains. Furthermore, three strains (1.1%) with high resistance caused by mutations in both parC and gyrA were detected. Fluoroquinolone resistance was present in various emm types.

  1. [Bacteriophage enzymes for the prevention and treatment of bacterial infections: stability and stabilization of the Streptococcus pyogenes cell lysing enzyme].

    PubMed

    Kliachko, N L; Dmitrieva, N F; Eshchina, A S; Ignatenko, O V; Filatova, L Iu; Raĭnina, E I; Kazarov, A K; Levashov, A V

    2008-01-01

    The effect of various compounds on the activity and stability of a phage-associated enzyme lysing cells of streptococci of groups A and C (PlyC) was investigated. Substantial inhibition of the enzyme activity was revealed at an increased ionic strength (in the presence of NaCl) and upon the addition of carbohydrates (mono-, di-, and polysaccharides), i.e., agents stabilizing many enzymes. It was established that the enzyme activity was substantially reduced in the presence of positively charged polyelectrolytes and surfactants, whereas incubation with micelle-forming substances and negatively charged polyelectrolytes led to PlyC activation and stabilization. It was shown that, in the mycelial 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 practically completely lost its activity in 2 days. Characteristics of the enzyme thermal inactivation were found, in particular, its semiinactivation time at various temperatures; these allowed us to estimate its behavior at any temperature and to recommend conditions for its storage and use.

  2. 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

  3. Highly effective renaturation of a streptokinase from Streptococcus pyogenes DT7 as inclusion bodies overexpressed in Escherichia coli.

    PubMed

    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.

  4. 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.

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

    PubMed Central

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

    2016-01-01

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

  6. 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

  7. Multilocus sequence analysis of Streptococcus canis confirms the zoonotic origin of human infections and reveals genetic exchange with Streptococcus dysgalactiae subsp. equisimilis.

    PubMed

    Pinho, M D; Matos, S C; Pomba, C; Lübke-Becker, A; Wieler, L H; Preziuso, S; Melo-Cristino, J; Ramirez, M

    2013-04-01

    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.

  8. 75 FR 54017 - New Animal Drugs; Change of Sponsor; Penicillin G Benzathine and Penicillin G Procaine Suspension...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-03

    ... pneumonia (Streptococcus spp., Actinomyces pyogenes, Staphylococcus aureus); upper respiratory infections such as rhinitis or pharyngitis (A. pyogenes); blackleg (Clostridium chauvoei). * * * * *...

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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 ...

  14. 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.

  15. Streptococcus intermedius Bacteremia and Liver Abscess following a Routine Dental Cleaning.

    PubMed

    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.

  16. Conjugative Transfer of the Integrative Conjugative Elements ICESt1 and ICESt3 from Streptococcus thermophilus▿ †

    PubMed Central

    Bellanger, Xavier; Roberts, Adam P.; Morel, Catherine; Choulet, Frédéric; Pavlovic, Guillaume; Mullany, Peter; Decaris, Bernard; Guédon, Gérard

    2009-01-01

    Integrative and conjugative elements (ICEs), also called conjugative transposons, are genomic islands that excise, self-transfer by conjugation, and integrate in the genome of the recipient bacterium. The current investigation shows the intraspecies conjugative transfer of the first described ICEs in Streptococcus thermophilus, ICESt1 and ICESt3. Mitomycin C, a DNA-damaging agent, derepresses ICESt3 conjugative transfer almost 25-fold. The ICESt3 host range was determined using various members of the Firmicutes as recipients. Whereas numerous ICESt3 transconjugants of Streptococcus pyogenes and Enterococcus faecalis were recovered, only one transconjugant of Lactococcus lactis was obtained. The newly incoming ICEs, except the one from L. lactis, are site-specifically integrated into the 3′ end of the fda gene and are still able to excise in these transconjugants. Furthermore, ICESt3 was retransferred from E. faecalis to S. thermophilus. Recombinant plasmids carrying different parts of the ICESt1 recombination module were used to show that the integrase gene is required for the site-specific integration and excision of the ICEs, whereas the excisionase gene is required for the site-specific excision only. PMID:19181800

  17. 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

  18. 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

  19. 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

  20. 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

  1. Molecular epidemiology of group A streptococcus causing scarlet fever in northern Taiwan, 2001-2002.

    PubMed

    Chen, Ying-Yan; Huang, Chung-Ter; Yao, Shu-Man; Chang, Yi-Ching; Shen, Pei-Wun; Chou, Chen-Ying; Li, Shu-Ying

    2007-07-01

    In this study, 830 Streptococcus pyogenes isolates collected between 2001 and 2002 from patients with scarlet fever in northern Taiwan were analyzed by M protein gene (emm) sequence typing, pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility testing. A total of 21 emm types and 56 PFGE patterns were identified. The most frequent emm types were emm1 (29.2%), emm4 (24.1%), emm12 (19.0%), emm6 (15.8%), stIL103 (5.7%), and emm22 (1.9%). Antimicrobial resistance profiles were determined, and resistance to erythromycin (24.6%), clindamycin (2.0%), and chloramphenicol (1.3%) was detected. Five major emm types (emm4, emm12, emm1, emm22, and emm6) accounted for 95.6% of the erythromycin-resistant isolates. The decreased prevalence of erythromycin-resistant emm12 strains coincided with the overall decrease in erythromycin resistance from 32.1% in 2001 to 21.1% in 2002 in Taiwan. Five major clones (emm4/2000, emm12/0000, emm4/2010, emm1/1000, and emm22/8100) represented 72.1% of the erythromycin-resistant isolates. The survey of group A Streptococcus emm types, genetic diversity, and antibiotic resistance has direct relevance to current antimicrobial use policies and potential vaccine development strategies.

  2. 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.

  3. 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

  4. 21 CFR 522.1696a - Penicillin G benzathine and penicillin G procaine suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Conditions of use. (A) Treatment of bacterial pneumonia (Streptococcus spp., Actinomyces pyogenes pyogenes, Staphylococcus aureus); upper respiratory infections such as rhinitis or pharyngitis (A. pyogenes);...

  5. Subtractive genomics approach to identify putative drug targets and identification of drug-like molecules for beta subunit of DNA polymerase III in Streptococcus species.

    PubMed

    Georrge, John J; Umrania, V V

    2012-07-01

    The prolonged use of the antibiotics over the years has transformed many organisms resistant to multiple drugs. This has made the field of drug discovery of vital importance in curing various infections and diseases. The drugs act by binding to a specific target protein of prime importance for the cell's survival. Streptococcus agalactiae, Streptococcus pneumoniae, and Streptococcus pyogenes are the few gram positive organisms that have developed resistance to drugs. It causes pneumonia, meningitis, pharyngitis, otitis media, sinusitis, bacteremia, pericarditis, and arthritis infections. The present study was carried out to identify potential drug targets and inhibitors for beta subunit of DNA polymerase III in these three Streptococcus species that might facilitate the discovery of novel drugs in near future. Various steps were adopted to find out novel drug targets. And finally 3D structure of DNA polymerase III subunit beta was modeled. The ligand library was generated from various databases to find the most suitable ligands. All the ligands were docked using Molegro Virtual Docker and the lead molecules were investigated for ADME and toxicity. PMID:22415782

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. Genetic diversity and virulence properties of Streptococcus dysgalactiae subsp. equisimilis from different sources.

    PubMed

    Gherardi, Giovanni; Imperi, Monica; Palmieri, Claudio; Magi, Gloria; Facinelli, Bruna; Baldassarri, Lucilla; Pataracchia, Marco; Creti, Roberta

    2014-01-01

    A recent increase in virulence of pathogenic Streptococcus dysgalactiae subsp. equisimilis (SDSE) has been widely proposed. Such an increase may be partly explained by the acquisition of new virulence traits by horizontal gene transfer from related streptococci such as Streptococcus pyogenes (GAS) and Streptococcus agalactiae (GBS). A collection of 54 SDSE strains isolated in Italy in the years 2000-2010 from different sources (paediatric throat carriage, invasive and non-invasive diseases) was characterized by emm typing and pulsed-field gel electrophoresis (PFGE) analysis. The virulence repertoire was evaluated by PCR for the presence of GAS superantigen (spe) genes, the streptolysin S (sagA) gene, the group G fibronectin-binding protein (gfbA) gene and GAS-GBS alpha-like protein family (alp) genes; moreover, the ability to invade human epithelial cells was investigated. Resistance to tetracycline, erythromycin and clindamycin was assessed. The combined use of emm typing and PFGE proved to be a reliable strategy for the epidemiological analysis of SDSE isolates. The most frequent emm types were the same as those more frequently reported in other studies, thus indicating the diffusion of a limited number of a few successful emm types fit to disseminate in humans. The speG gene was detected in SDSE strains of different genetic backgrounds. Erythromycin resistance determined by the erm(T) gene, and the unusual, foggy MLSB phenotype, observed in one and seven strains, respectively, have never previously, to our knowledge, been reported in SDSE. Moreover, a new member of the alp family was identified. The identification of new antibiotic and virulence determinants, despite the small size of the sample analysed, shows the importance of constant attention to monitoring the extent of lateral gene transfer in this emerging pathogen.

  13. 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

  14. Replacing and Additive Horizontal Gene Transfer in Streptococcus

    PubMed Central

    Choi, Sang Chul; Rasmussen, Matthew D.; Hubisz, Melissa J.; Gronau, Ilan; Stanhope, Michael J.; Siepel, Adam

    2012-01-01

    The prominent role of Horizontal Gene Transfer (HGT) in the evolution of bacteria is now well documented, but few studies have differentiated between evolutionary events that predominantly cause genes in one lineage to be replaced by homologs from another lineage (“replacing HGT”) and events that result in the addition of substantial new genomic material (“additive HGT”). Here in, we make use of the distinct phylogenetic signatures of replacing and additive HGTs in a genome-wide study of the important human pathogen Streptococcus pyogenes (SPY) and its close relatives S. dysgalactiae subspecies equisimilis (SDE) and S. dysgalactiae subspecies dysgalactiae (SDD). Using recently developed statistical models and computational methods, we find evidence for abundant gene flow of both kinds within each of the SPY and SDE clades and of reduced levels of exchange between SPY and SDD. In addition, our analysis strongly supports a pronounced asymmetry in SPY–SDE gene flow, favoring the SPY-to-SDE direction. This finding is of particular interest in light of the recent increase in virulence of pathogenic SDE. We find much stronger evidence for SPY–SDE gene flow among replacing than among additive transfers, suggesting a primary influence from homologous recombination between co-occurring SPY and SDE cells in human hosts. Putative virulence genes are correlated with transfer events, but this correlation is found to be driven by additive, not replacing, HGTs. The genes affected by additive HGTs are enriched for functions having to do with transposition, recombination, and DNA integration, consistent with previous findings, whereas replacing HGTs seen to influence a more diverse set of genes. Additive transfers are also found to be associated with evidence of positive selection. These findings shed new light on the manner in which HGT has shaped pathogenic bacterial genomes. PMID:22617954

  15. SFS, a Novel Fibronectin-Binding Protein from Streptococcus equi, Inhibits the Binding between Fibronectin and Collagen

    PubMed Central

    Lindmark, Hans; Guss, Bengt

    1999-01-01

    The obligate parasitic bacterium Streptococcus equi subsp. equi is the causative agent of strangles, a serious disease of the upper respiratory tract in horses. In this study we have, using shotgun phage display, cloned from S. equi subsp. equi and characterized a gene, called sfs, encoding a protein termed SFS, representing a new type of fibronectin (Fn)-binding protein. The sfs gene was found to be present in all 50 isolates of S. equi subsp. equi tested and in 41 of 48 S. equi subsp. zooepidemicus isolates tested. The sfs gene is down-regulated during growth in vitro compared to fnz, a previously characterized gene encoding an Fn-binding protein from S. equi subsp. zooepidemicus. Sequence comparisons revealed no similarities to previously characterized Fn-binding proteins, but high scores were obtained against collagen. Besides similarity due to the high content of glycine, serine, and proline residues present in both proteins, there was a nine-residue motif present both in collagen and in the Fn-binding domain of SFS. By searching the Oklahoma S. pyogenes database, we found that this motif is also present in a potential cell surface protein from S. pyogenes. Protein SFS was found to inhibit the binding between Fn and collagen in a concentration-dependent way. PMID:10225899

  16. 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

  17. 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

  18. 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.

  19. 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

  20. GLYOXYLATE FERMENTATION BY STREPTOCOCCUS ALLANTOICUS

    PubMed Central

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

    1964-01-01

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

  1. 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.

  2. Habitat, wildlife and one health: Arcanobacterium pyogenes in Maryland and Upper Eastern Shore white-tailed deer populations

    USGS Publications Warehouse

    Turner, Melissa M.; DePerno, Christopher S.; Conner, Mark C.; Eyler, T. Brian; Lancia, Richard A.; Klaver, Robert W.; Stoskopf, Michael K.

    2013-01-01

    Conclusion: Our study indicates A. pyogenes may be carried widely among white-tailed deer regardless of sex or age class, but we found no evidence the pathogen is acquired in utero. The distribution of A. pyogenes across regions and concentration in a region with low livestock levels suggests the potential for localized endemicity of the organism and the possibility that deer may serve as a maintenance reservoir for an emerging one health concern.

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

    PubMed

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

    2015-09-01

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

  4. 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

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

    PubMed

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

    2015-09-01

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

  6. Resistance to β-lactam antibiotic may influence nanH gene expression in Trueperella pyogenes isolated from bovine endometritis.

    PubMed

    Zhang, De-Xian; Tian, Kai; Han, Li-Mei; Wang, Qiu-Xia; Liu, Yao-Chuan; Tian, Chun-Lian; Liu, Ming-Chun

    2014-01-01

    Virulence could be modulated by many instinctive and environmental factors including oxygen, osmolarity and antimicrobial agents. This study aimed to investigate the correlation between drug resistance and the nanH expression in Trueperella pyogenes (T. pyogenes). Minimum inhibitory concentrations (MICs) of 6 β-lactam antimicrobial agents (penicillin G, amoxicillin, oxacillin, cefazolin, ceftiofur, and ampicillin) against T. pyogenes were tested by standard broth dilution method according to the protocols of the Clinical and Laboratory Standards Institute (CLSI), and real-time fluorescent quantitative reverse transcription-polymerase chain reaction (RT-PCR) was selected to investigate the mRNA expression levels of the nanH in T. pyogenes. All the isolates were resistant to atleast 2 of antimicrobial agents, and multidrug resistance (resistance to atleast 3 antimicrobials) was observed in 84.38% (27/32) of isolates. The mRNA expression levels of the nanH were significantly higher in comparison with that in ATCC19411, as the resistance profile enlarged, the nanH mRNA expression levels decreased in T. pyogenes. These results indicated that β-lactam antibiotic resistance in T. pyogenes may alter the expression of the nanH. PMID:24803199

  7. Diagnostic yield of computed tomography-guided bone biopsy and clinical outcomes of tuberculous and pyogenic spondylitis

    PubMed Central

    Joo, Eun-Jeong; Yeom, Joon-Sup; Ha, Young Eun; Park, So Yeon; Lee, Chong-Suh; Kim, Eun-Sang; Kang, Cheol-In; Chung, Doo-Ryeon; Song, Jae-Hoon; Peck, Kyong Ran

    2016-01-01

    Background/Aims: This study aimed to evaluate the efficacy of computed tomography (CT)-guided bone biopsy for the diagnosis of spinal infection and compared the clinical outcomes between tuberculous and pyogenic spinal infections. Methods: The retrospective cohort study included patients who received CT-guided bone biopsy at a tertiary hospital over the 13 years. Results: Among 100 patients, 67 had pyogenic spondylitis and 33 had tuberculous spondylitis. Pathogens were isolated from bone specimens obtained by CT-guided biopsy in 42 cases, with diagnostic yields of 61% (20/33) for tuberculous spondylitis and 33% (22/67) for pyogenic spondylitis. For 36 culture-proven pyogenic cases, Staphylococcus aureus was the most commonly isolated organism. Patients with pyogenic spondylitis more frequently presented with fever accompanied by an increase in inflammatory markers than did those with tuberculosis. Among all patients who underwent surgery, the incidence of late surgery performed one month after diagnosis was higher in patients with tuberculous infection (56.3%) than in those with pyogenic disease (23.3%, p = 0.026). Conclusions: Results obtained by CT-guided bone biopsy contributed to prompt diagnoses of spinal infections, especially those caused by tuberculosis. Despite administration of anti-tuberculous agents, patients with tuberculous spondylitis showed an increased tendency to undergo late surgery. PMID:27079327

  8. Evolution and Diversity of the Antimicrobial Resistance Associated Mobilome in Streptococcus suis: A Probable Mobile Genetic Elements Reservoir for Other Streptococci

    PubMed Central

    Huang, Jinhu; Ma, Jiale; Shang, Kexin; Hu, Xiao; Liang, Yuan; Li, Daiwei; Wu, Zuowei; Dai, Lei; Chen, Li; Wang, Liping

    2016-01-01

    Streptococcus suis is a previously neglected, newly emerging multidrug-resistant zoonotic pathogen. Mobile genetic elements (MGEs) play a key role in intra- and interspecies horizontal transfer of antimicrobial resistance (AMR) determinants. Although, previous studies showed the presence of several MGEs, a comprehensive analysis of AMR-associated mobilome as well as their interaction and evolution has not been performed. In this study, we presented the AMR-associated mobilome and their insertion hotspots in S. suis. Integrative conjugative elements (ICEs), prophages and tandem MGEs were located at different insertion sites, while 86% of the AMR-associated MGEs were inserted at rplL and rum loci. Comprehensive analysis of insertions at rplL and rum loci among four pathogenic Streptococcus species (Streptococcus agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes, and S. suis) revealed the existence of different groups of MGEs, including Tn5252, ICESp1108, and TnGBS2 groups ICEs, Φm46.1 group prophage, ICE_ICE and ICE_prophage tandem MGEs. Comparative ICE genomics of ICESa2603 family revealed that module exchange and acquisition/deletion were the main mechanisms in MGEs' expansion and evolution. Furthermore, the observation of tandem MGEs reflected a novel mechanism for MGE diversity. Moreover, an in vitro competition assay showed no visible fitness cost was observed between different MGE-carrying isolates and a conjugation assay revealed the transferability of ICESa2603 family of ICEs. Our statistics further indicated that the prevalence and diversity of MGEs in S. suis is much greater than in other three species which prompted our hypothesis that S. suis is probably a MGEs reservoir for other streptococci. In conclusion, our results showed that acquisition of MGEs confers S. suis not only its capability as a multidrug resistance pathogen, but also represents a paradigm to study the modular evolution and matryoshkas of MGEs. PMID:27774436

  9. Pyogenic granuloma, an unusual presentation of peripubertal vaginal bleeding. Case report and review of the literature.

    PubMed

    Barasoain-Millán, Alberto; Rodriguez-Contreras, Francisco Javier; Guerrero-Fernandez, Julio; Merino, Maria Beato; Gonzalez-Casado, Isabel

    2015-03-01

    Pyogenic granuloma, also named lobular capillary hemangioma, is a common proliferative vascular lesion known as a benign condition despite its rapid growth. It may appear in any cutaneous or mucosal surface but is usually restricted to the oral cavity. It is characterized by a friable mulberry-like lesion that can be sessile or pedunculated. Bleeding is usually its first clinical manifestation. Locations on respiratory, digestive and genital tracts are uncommon and sporadic. We describe the occurrence of an intravaginal pyogenic granuloma in a peripubertal girl with recurrent vaginal bleeding. This is the first reported case of a genital tract lobular capillary hemangioma in pediatric age to our knowledge. Therefore, we suggest this entity in the differential diagnosis of an unclear peripubertal vaginal bleeding.

  10. Infantile multiple large pyogenic granuloma on burned skin. Case report and review of literature*

    PubMed Central

    Dastgheib, Ladan; Maghami, Zohreh; Aslani, Fatemeh Sari

    2016-01-01

    Pyogenic granuloma (PG) is a benign vascular lesion of the skin and mucous membranes, presenting as a solitary, red, pedunculated papule that bleeds easily and which appears to be a reactive vascular proliferation to minor injury. These lesions are more common in children and are mostly seen in exposed sites. Multiple disseminated PG is a rare condition. This report describes an infant with multiple, disseminated, pyogenic granulomas following burns from boiling milk. We reviewed literature published in English and found 9 cases. Six cases were provoked by hot milk, 2 by hot water, while the cause of the other case is unknown. Angiogiogenetic activity in milk may explain PG development in these patients. PMID:27192522

  11. Identification of Trueperella pyogenes Isolated from Bovine Mastitis by Fourier Transform Infrared Spectroscopy

    PubMed Central

    Nagib, Samy; Rau, Jörg; Sammra, Osama; Lämmler, Christoph; Schlez, Karen; Zschöck, Michael; Prenger-Berninghoff, Ellen; Klein, Guenter; Abdulmawjood, Amir

    2014-01-01

    The present study was designed to investigate the potential of Fourier transform infrared (FT-IR) spectroscopy to identify Trueperella (T.) pyogenes isolated from bovine clinical mastitis. FT-IR spectroscopy was applied to 57 isolates obtained from 55 cows in a period from 2009 to 2012. Prior to FT-IR spectroscopy these isolates were identified by phenotypic and genotypic properties, also including the determination of seven potential virulence factor encoding genes. The FT-IR analysis revealed a reliable identification of all 57 isolates as T. pyogenes and a clear separation of this species from the other species of genus Trueperella and from species of genus Arcanobacterium and Actinomyces. The results showed that all 57 isolates were assigned to the correct species indicating that FT-IR spectroscopy could also be efficiently used for identification of this bacterial pathogen. PMID:25133407

  12. Percutaneous Transpedicular Interbody Fusion Technique in Percutaneous Pedicle Screw Stabilization for Pseudoarthrosis Following Pyogenic Spondylitis.

    PubMed

    Ikuta, Ko; Masuda, Keigo; Yonekura, Yutaka; Kitamura, Takahiro; Senba, Hideyuki; Shidahara, Satoshi

    2016-04-01

    This report introduces a percutaneous transpedicular interbody fusion (PTPIF) technique in posterior stabilization using percutaneous pedicle screws (PPSs). An 81-year-old man presented with pseudoarthrosis following pyogenic spondylitis 15 months before. Although no relapse of infection was found, he complained of obstinate low back pain and mild neurological symptoms. Radiological evaluations showed a pseudoarthrosis following pyogenic spondylitis at T11-12. Posterior stabilization using PPSs from Th9 to L2 and concomitant PTPIF using autologous iliac bone graft at T11-12 were performed. Low back pain and neurological symptoms were immediately improved after surgery. A solid interbody fusion at T11-12 was completed 9 months after surgery. The patient had no restriction of daily activity and could play golf at one year after surgery. PTPIF might be a useful option for perform segmental fusion in posterior stabilization using PPSs. PMID:27114777

  13. Pyogenic Bacterial Infections in Humans with MyD88 Deficiency

    PubMed Central

    von Bernuth, Horst; Picard, Capucine; Jin, Zhongbo; Pankla, Rungnapa; Xiao, Hui; Ku, Cheng-Lung; Chrabieh, Maya; Mustapha, Imen Ben; Ghandil, Pegah; Camcioglu, Yildiz; Vasconcelos, Júlia; Sirvent, Nicolas; Guedes, Margarida; Vitor, Artur Bonito; Herrero-Mata, María José; Aróstegui, Juan Ignacio; Rodrigo, Carlos; Alsina, Laia; Ruiz-Ortiz, Estibaliz; Juan, Manel; Fortuny, Claudia; Yagüe, Jordi; Antón, Jordi; Pascal, Mariona; Chang, Huey-Hsuan; Janniere, Lucile; Rose, Yoann; Garty, Ben-Zion; Chapel, Helen; Issekutz, Andrew; Maródi, László; Rodriguez-Gallego, Carlos; Banchereau, Jacques; Abel, Laurent; Li, Xiaoxia; Chaussabel, Damien; Puel, Anne; Casanova1, Jean-Laurent

    2009-01-01

    MyD88 is a key downstream adapter for most Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs). MyD88 deficiency in mice leads to susceptibility to a broad range of pathogens in experimental settings of infection. We describe a distinct situation in a natural setting of human infection. Nine children with autosomal recessive MyD88 deficiency suffered from life-threatening, often recurrent pyogenic bacterial infections, including invasive pneumococcal disease. However, these patients were otherwise healthy, with normal resistance to other microbes. Their clinical status improved with age, but not due to any cellular leakiness in MyD88 deficiency. The MyD88-dependent TLRs and IL-1Rs are therefore essential for protective immunity to a small number of pyogenic bacteria, but redundant for host defense to most natural infections. PMID:18669862

  14. Endocarditis caused by unusual Streptococcus species (Streptococcus pluranimalium)

    PubMed Central

    Fotoglidis, A; Pagourelias, E; Kyriakou, P; Vassilikos, V

    2015-01-01

    Background Infective endocarditis in intravenous drug abusers is caused mainly by Staphylococcus species and usually affects the right heart valves. Case Description We report the case of a 37-years-old intravenous drug abuser, who was diagnosed with infective endocarditis of the mitral and aortic valve. An unusual Streptococcus species (Streptococcus pluranimalium) was isolated from surgical specimens (peripheral arterial emboli, valves’ vegetations) which, according to the literature, is related to animals’ diseases such as infective endocarditis in adult broiler parents, with no references existing regarding causing such disease in humans. This unusual coccus infection caused specific clinical features (sizable vegetation on mitral valve >2cm, smaller vegetations on aortic valve, systemic emboli), resistance to antimicrobial therapy, rapid progression of the disease (despite of medical therapy and surgical replacement of both valves), and finally the death of the patient two months after the initial presentation of infective endocarditis. Conclusion Unusual cases of infective endocarditis in intravenous drug abusers are emerging and are characterized by changing microbiological profile and varying clinical characteristics. Clinical doctors must be aware of these cases, especially when their patients present an atypical clinical course, and reappraise their medical management. Hippokratia 2015; 19 (2):182-185. PMID:27418771

  15. Streptococcus milleri in the appendix.

    PubMed Central

    Poole, P M; Wilson, G

    1977-01-01

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

  16. Streptococcus milleri in the appendix.

    PubMed

    Poole, P M; Wilson, G

    1977-10-01

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

  17. Pyogenic liver abscess in beta-thalassemia major--report of two cases.

    PubMed

    Hwang, C F; Lee, C Y; Lee, P I; Chen, J M; Lli, K H; Lin, D T; Chang, M H

    1994-01-01

    Pyogenic liver abscess, which may lead to devastating consequences, is an uncommon medical problem in pediatrics and has generally been reported in compromised hosts. This article describes two patients with beta-thalassemia major and hemochromatosis complicated by Klebsiella pneumoniae liver abscess. One of the patients had severe complications, including subphrenic abscess, pleural effusion and meningitis. To present knowledge, the occurrence of K. pneumoniae liver abscess in patients with beta-thalassemia major has never before been reported in the literature.

  18. Arrangement and number of clustered regularly interspaced short palindromic repeat spacers are associated with erythromycin susceptibility in emm12, emm75 and emm92 of group A streptococcus.

    PubMed

    Zheng, P-X; Chiang-Ni, C; Wang, S-Y; Tsai, P-J; Kuo, C-F; Chuang, W-J; Lin, Y-S; Liu, C-C; Wu, J-J

    2014-06-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) are composed of numerous repeat-spacer units and are considered a prokaryotic defence system against foreign nucleic acids. Since antibiotic-resistant genes are frequently encoded in foreign nucleic acids, the aim of this study was to test whether erythromycin susceptibility in group A streptococcus (Streptococcus pyogenes) is associated with characteristics of CRISPR elements. Erythromycin susceptibility of 330 isolates collected between 1997 and 2003 was analysed. Among 29 emm types, emm12, emm75 and emm92 showed significant changes in erythromycin-resistance rates. By sequencing the spacers from two CRISPR loci, spacer contents in emm12, emm75 and emm92 strains were associated with erythromycin susceptibility. Strains with fewer spacers were more resistant to erythromycin. Moreover, in emm4 strains, which showed no significant change in their annual erythromycin-resistance rate, CRISPR type and number of spacers were not correlated with erythromycin susceptibility. These results highlight a novel association between CRISPR spacer content and erythromycin susceptibility in group A streptococcus.

  19. 21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Hemolytic staphylococcus, Streptococcus spp., Bacterial pulmonary infections caused by Brucella bronchiseptica, Streptococcus pyogenes, Staphylococcus aureus, secondary bacterial infections caused...

  20. 21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Hemolytic staphylococcus, Streptococcus spp., Bacterial pulmonary infections caused by Brucella bronchiseptica, Streptococcus pyogenes, Staphylococcus aureus, secondary bacterial infections caused...

  1. 21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Hemolytic staphylococcus, Streptococcus spp., Bacterial pulmonary infections caused by Brucella bronchiseptica, Streptococcus pyogenes, Staphylococcus aureus, secondary bacterial infections caused...

  2. 21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Hemolytic staphylococcus, Streptococcus spp., Bacterial pulmonary infections caused by Brucella bronchiseptica, Streptococcus pyogenes, Staphylococcus aureus, secondary bacterial infections caused...

  3. 21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Hemolytic staphylococcus, Streptococcus spp., Bacterial pulmonary infections caused by Brucella bronchiseptica, Streptococcus pyogenes, Staphylococcus aureus, secondary bacterial infections caused...

  4. Habitat, wildlife, and one health: Arcanobacterium pyogenes in Maryland and Upper Eastern Shore white-tailed deer populations

    PubMed Central

    Turner, Melissa M.; DePerno, Christopher S.; Conner, Mark C.; Eyler, T. Brian; Lancia, Richard A.; Klaver, Robert W.; Stoskopf, Michael K.

    2013-01-01

    Background Understanding the distribution of disease in wildlife is key to predicting the impact of emerging zoonotic one health concerns, especially for wildlife species with extensive human and livestock interfaces. The widespread distribution and complex interactions of white-tailed deer (Odocoileus virginianus) with humans suggest deer population health and management may have implications beyond stewardship of the animals. The intracranial abscessation suppurative meningitis (IASM) disease complex in deer has been linked to Arcanobacterium pyogenes, an under-diagnosed and often misdiagnosed organism considered commensal in domestic livestock but associated with serious disease in numerous species, including humans. Methods Our study used standard bacterial culture techniques to assess A. pyogenes prevalence among male deer sampled across six physiogeographic regions in Maryland and male and female deer in the Upper Eastern Shore under Traditional Deer Management (TDM) and Quality Deer Management (QDM), a management protocol that alters population demographics in favor of older male deer. Samples were collected from antler pedicles for males, the top of the head where pedicles would be if present for females, or the whole dorsal frontal area of the head for neonates. We collected nasal samples from all animals by swabbing the nasopharyngeal membranes. A gram stain and catalase test were conducted, and aerobic bacteria were identified to genus and species when possible. We evaluated the effect of region on whether deer carried A. pyogenes using Pearson's chi-square test with Yates’ continuity correction. For the white-tailed deer management study, we tested whether site, age class and sex predisposed animals to carrying A. pyogenes using binary logistic regression. Results A. pyogenes was detected on deer in three of the six regions studied, and was common in only one region, the Upper Eastern Shore. In the Upper Eastern Shore, 45% and 66% of antler and nasal

  5. RNA-mediated regulation in Gram-positive pathogens: an overview punctuated with examples from the group A Streptococcus

    PubMed Central

    Miller, Eric W.; Cao, Tram N.; Pflughoeft, Kathryn J.; Sumby, Paul

    2014-01-01

    RNA-based mechanisms of regulation represent a ubiquitous class of regulators that are associated with diverse processes including nutrient sensing, stress response, modulation of horizontal gene transfer, and virulence factor expression. While better studied in Gram-negative bacteria, the literature is replete with examples of the importance of RNA-mediated regulatory mechanisms to the virulence and fitness of Gram-positives. Regulatory RNAs are classified as cis-acting, e.g. riboswitches, which modulate the transcription, translation, or stability of co-transcribed RNA, or trans-acting, e.g. small regulatory RNAs, which target separate mRNAs or proteins. The group A Streptococcus (GAS, Streptococcus pyogenes) is a Gram-positive bacterial pathogen from which several regulatory RNA mechanisms have been characterized. The study of RNA-mediated regulation in GAS has uncovered novel concepts with respect to how small regulatory RNAs may positively regulate target mRNA stability, and to how CRISPR RNAs are processed from longer precursors. This review provides an overview of RNA-mediated regulation in Gram-positive bacteria, and is highlighted with specific examples from GAS research. The key roles that these systems play in regulating bacterial virulence are discussed and future perspectives outlined. PMID:25091277

  6. Differential Virulence Gene Expression of Group A Streptococcus Serotype M3 in Response to Co-Culture with Moraxella catarrhalis

    PubMed Central

    Verhaegh, Suzanne J. C.; Flores, Anthony R.; van Belkum, Alex; Musser, James M.; Hays, John P.

    2013-01-01

    Streptococcus pyogenes (group A Streptococcus, GAS) and Moraxella catarrhalis are important colonizers and (opportunistic) pathogens of the human respiratory tract. However, current knowledge regarding colonization and pathogenic potential of these two pathogens is based on work involving single bacterial species, even though the interplay between respiratory bacterial species is increasingly important in niche occupation and the development of disease. Therefore, to further define and understand polymicrobial species interactions, we investigated whether gene expression (and hence virulence potential) of GAS would be affected upon co-culture with M. catarrhalis. For co-culture experiments, GAS and M. catarrhalis were cultured in Todd-Hewitt broth supplemented with 0.2% yeast extract (THY) at 37°C with 5% CO2 aeration. Each strain was grown in triplicate so that triplicate experiments could be performed. Bacterial RNA was isolated, cDNA synthesized, and microarray transcriptome expression analysis performed. We observed significantly increased (≥4-fold) expression for genes playing a role in GAS virulence such as hyaluronan synthase (hasA), streptococcal mitogenic exotoxin Z (smeZ) and IgG endopeptidase (ideS). In contrast, significantly decreased (≥4-fold) expression was observed in genes involved in energy metabolism and in 12 conserved GAS two-component regulatory systems. This study provides the first evidence that M. catarrhalis increases GAS virulence gene expression during co-culture, and again shows the importance of polymicrobial infections in directing bacterial virulence. PMID:23626831

  7. Streptococcus agalactiae mastitis: a review.

    PubMed Central

    Keefe, G P

    1997-01-01

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

  8. Genetic and biochemical properties of a hemolysin (pyolysin) produced by a swine isolate of Arcanobacterium (Actinomyces) pyogenes.

    PubMed

    Ikegami, M; Hashimoto, N; Kaidoh, T; Sekizaki, T; Takeuchi, S

    2000-01-01

    Arcanobacterium (Actinomyces) pyogenes, a causative agent of various pyogenic diseases in domestic animals, produces a hemolysin which is thought to be an important virulence factor. This hemolysin was purified from the culture supernatant of A. pyogenes swine isolate. The purified hemolysin showed a single band with a molecular mass of 56 kDa on SDS-polyacrylamide gel electrophoresis, and its isoelectric point was 9.2. The activity of this hemolysin was not enhanced by the addition of L-cysteine or sodium thioglycolate, but it was inhibited by cholesterol. The gene encoding the hemolysin was cloned, sequenced and expressed in Escherichia coli by means of ZAP Express vector. Analysis by SDS-polyacrylamide gel electrophoresis with immunoblotting showed that the molecular weight of the hemolysin expressed in E. coli is the same as that of the hemolysin purified from A. pyogenes. Nucleotide sequence analysis revealed an open reading frame of 1,605 bp encoding a 534 amino acid protein of 57,989 Da. The nucleotide sequence of the hemolysin gene from A. pyogenes swine isolate differed only slightly (97.6% identity) from the sequence of plo gene from A. pyogenes strain BBR1 reported by Billington et al (J. Bacteriol. 179: 6100-6106, 1997). The cysteine residue existed in the undecapeptide region of the hemolysin, which is highly conserved in thiol-activated cytolysins (cholesterol-binding cytolysins), and is replaced with alanine. Therefore, the hemolysin of A. pyogenes seems to be a novel member of the thiol-activated cytolysin family. PMID:10711593

  9. Appendectomy correlates with increased risk of pyogenic liver abscess: A population-based cohort study in Taiwan.

    PubMed

    Liao, Kuan-Fu; Lai, Shih-Wei; Lin, Cheng-Li; Chien, Sou-Hsin

    2016-06-01

    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

  10. Structure-Informed Design of an Enzymatically Inactive Vaccine Component for Group A Streptococcus

    PubMed Central

    Henningham, Anna; Ericsson, Daniel J.; Langer, Karla; Casey, Lachlan W.; Jovcevski, Blagojce; Chhatwal, G. Singh; Aquilina, J. Andrew; Batzloff, Michael R.; Kobe, Bostjan; Walker, Mark J.

    2013-01-01

    ABSTRACT Streptococcus pyogenes (group A Streptococcus [GAS]) causes ~700 million human infections/year, resulting in >500,000 deaths. There is no commercial GAS vaccine available. The GAS surface protein arginine deiminase (ADI) protects mice against a lethal challenge. ADI is an enzyme that converts arginine to citrulline and ammonia. Administration of a GAS vaccine preparation containing wild-type ADI, a protein with inherent enzymatic activity, may present a safety risk. In an approach intended to maximize the vaccine safety of GAS ADI, X-ray crystallography and structural immunogenic epitope mapping were used to inform vaccine design. This study aimed to knock out ADI enzyme activity without disrupting the three-dimensional structure or the recognition of immunogenic epitopes. We determined the crystal structure of ADI at 2.5 Å resolution and used it to select a number of amino acid residues for mutagenesis to alanine (D166, E220, H275, D277, and C401). Each mutant protein displayed abrogated activity, and three of the mutant proteins (those with the D166A, H275A, and D277A mutations) possessed a secondary structure and oligomerization state equivalent to those of the wild type, produced high-titer antisera, and avoided disruption of B-cell epitopes of ADI. In addition, antisera raised against the D166A and D277A mutant proteins bound to the GAS cell surface. The inactivated D166A and D277A mutant ADIs are ideal for inclusion in a GAS vaccine preparation. There is no human ortholog of ADI, and we confirm that despite limited structural similarity in the active-site region to human peptidyl ADI 4 (PAD4), ADI does not functionally mimic PAD4 and antiserum raised against GAS ADI does not recognize human PAD4. PMID:23919999

  11. Superoxide Dismutase and Oxygen Metabolism in Streptococcus faecalis and Comparisons with Other Organisms

    PubMed Central

    Britton, Larry; Malinowski, Douglas P.; Fridovich, Irwin

    1978-01-01

    Streptococcus faecalis contains a single superoxide dismutase that has been purified to homogeneity with a 55% yield. This enzyme has a molecular weight of 45,000 and is composed of two subunits of equal size. It contains 1.3 atoms of manganese per molecule. Its amino acid composition was determined and is compared with that for the superoxide dismutases from Escherichia coli, Streptococcus mutans, and Mycobacterium lepraemurium. When used as an antigen in rabbits, the S. faecalis enzyme elicited the formation of a precipitating and inhibiting antibody. This antibody cross-reacted with the superoxide dismutase present in another strain of S. faecalis, but neither inhibited nor precipitated the superoxide dismutases in a wide range of other bacteria, including several other streptococci, such as S. pyogenes, S. pneumoniae, and S. lactis. The inhibiting antibody was used to suppress the superoxide dismutase activity present in cell extracts of S. faecalis and thus allow the demonstration that 17% of the total oxygen consumption by such extracts, in the presence of reduced nicotinamide adenine dinucleotide, was associated with the production of O2−. A variety of bacterial species were surveyed for their content of superoxide dismutases. The iron-containing enzyme was distinguished from the manganese-containing enzyme through the use of H2O2, which inactivates the former more readily than the latter. Some of the bacteria appeared to contain only the iron enzyme, others only the manganese enzyme, and still others both. Indeed, some had multiple, electrophoretically distinct superoxide dismutases in both categories. There was no discernible absolute relationship between the types of superoxide dismutases in a particular organism and their Gram-stain reaction. Images PMID:206536

  12. Distinct Structural Features of the Peroxide Response Regulator from Group A Streptococcus Drive DNA Binding

    PubMed Central

    Hammel, Michal; Nix, Jay C.; Tseng, Hsiao-Ling; Tsou, Chih-Cheng; Fei, Chun-Hsien; Chiou, Huo-Sheng; Jeng, U-Ser; Lin, Yee-Shin; Chuang, Woei-Jer; Wu, Jiunn-Jong; Wang, Shuying

    2014-01-01

    Group A streptococcus (GAS, Streptococcus pyogenes) is a strict human pathogen that causes severe, invasive diseases. GAS does not produce catalase, but has an ability to resist killing by reactive oxygen species (ROS) through novel mechanisms. The peroxide response regulator (PerR), a member of ferric uptake regulator (Fur) family, plays a key role for GAS to cope with oxidative stress by regulating the expression of multiple genes. Our previous studies have found that expression of an iron-binding protein, Dpr, is under the direct control of PerR. To elucidate the molecular interactions of PerR with its cognate promoter, we have carried out structural studies on PerR and PerR-DNA complex. By combining crystallography and small-angle X-ray scattering (SAXS), we confirmed that the determined PerR crystal structure reflects its conformation in solution. Through mutagenesis and biochemical analysis, we have identified DNA-binding residues suggesting that PerR binds to the dpr promoter at the per box through a winged-helix motif. Furthermore, we have performed SAXS analysis and resolved the molecular architecture of PerR-DNA complex, in which two 30 bp DNA fragments wrap around two PerR homodimers by interacting with the adjacent positively-charged winged-helix motifs. Overall, we provide structural insights into molecular recognition of DNA by PerR and define the hollow structural arrangement of PerR-30bpDNA complex, which displays a unique topology distinct from currently proposed DNA-binding models for Fur family regulators. PMID:24586487

  13. covR Mediated Antibiofilm Activity of 3-Furancarboxaldehyde Increases the Virulence of Group A Streptococcus

    PubMed Central

    Ashwinkumar Subramenium, Ganapathy; Viszwapriya, Dharmaprakash; Iyer, Prasanth Mani; Balamurugan, Krishnaswamy; Karutha Pandian, Shunmugiah

    2015-01-01

    Background Group A streptococcus (GAS, Streptococcus pyogenes), a multi-virulent, exclusive human pathogen responsible for various invasive and non-invasive diseases possesses biofilm forming phenomenon as one of its pathogenic armaments. Recently, antibiofilm agents have gained prime importance, since inhibiting the biofilm formation is expected to reduce development of antibiotic resistance and increase their susceptibility to the host immune cells. Principal Findings The current study demonstrates the antibiofilm activity of 3Furancarboxaldehyde (3FCA), a floral honey derived compound, against GAS biofilm, which was divulged using crystal violet assay, light microscopy, and confocal laser scanning microscopy. The report is extended to study its effect on various aspects of GAS (morphology, virulence, aggregation) at its minimal biofilm inhibitory concentration (132μg/ml). 3FCA was found to alter the growth pattern of GAS in solid and liquid medium and increased the rate of auto-aggregation. Electron microscopy unveiled the increase in extra polymeric substances around cell. Gene expression studies showed down-regulation of covR gene, which is speculated to be the prime target for the antibiofilm activity. Increased hyaluronic acid production and down regulation of srtB gene is attributed to the enhanced rate of auto-aggregation. The virulence genes (srv, mga, luxS and hasA) were also found to be over expressed, which was manifested with the increased susceptibility of the model organism Caenorhabditis elegans to 3FCA treated GAS. The toxicity of 3FCA was ruled out with no adverse effect on C. elegans. Significance Though 3FCA possess antibiofilm activity against GAS, it was also found to increase the virulence of GAS. This study demonstrates that, covR mediated antibiofilm activity may increase the virulence of GAS. This also emphasizes the importance to analyse the acclimatization response and virulence of the pathogen in the presence of antibiofilm compounds

  14. TNF-alpha is secreted by monocytes in transit to become macrophages, but not by peripheral blood monocytes, following OK-432 (lyophilized S. pyogenes) stimulation.

    PubMed

    Olsnes, C; Stavang, H; Olofsson, J; Aarstad, H J

    2007-12-01

    OK-432, penicillin-killed Streptococcus pyogenes, is used in treating lymphangiomas and carcinomas. We have studied proinflammatory interleukin (IL) secretion following OK-432 stimulation of total blood, peripheral blood mononuclear cell (PBMC) and purified monocytes in vitro. OK-432 stimulation of purified monocytes gave IL-1beta, IL-1RA, IL-6, IL-12p40 and tumour necrosis factor (TNF)-alpha response. OK-432 stimulation of cells within blood did, however, not yield TNF-alpha secretion. When PBMC or monocytes were cultured in low-attachment wells a decreased IL secretion was observed compared to adherent cells. Inhibition of Syk kinase with piceatannol, only at high, non-specific doses, but not PI3 kinase inhibition with LY294002 or Wortmannin, decreased monocyte IL response to OK-432. This shows that beta(1-3)-integrin receptor function is not necessary for monocyte OK-432-stimulated TNF-alpha secretion. Direct blockage of the beta(2)-integrin (CD18) receptor by anti-CD18 antibody was also unable to prevent the stimulating effects of OK-432 in human monocytes. On the other hand, Syk phosphorylation is elevated upon adherence of monocytes and this is further increased by OK-432 stimulation, as shown by Western blot. The Fc-receptor was also ruled out as a main receptor of the OK-432 monocyte response. In conclusion, TNF-alpha secretion is only found in monocytes removed from blood. This TNF-alpha secretion is not mediated through the beta(1-3)-integrin receptors. OK-432 may act as a target-seeking substance whereby only monocytes adhered, e.g. to a tumour cell, become cytotoxic in part explaining why OK-432 is well suited as a cancer treatment drug.

  15. Structural analysis of the lipoteichoic acids isolated from bovine mastitis Streptococcus uberis 233, Streptococcus dysgalactiae 2023 and Streptococcus agalactiae 0250.

    PubMed

    Czabańska, Anna; Neiwert, Olga; Lindner, Buko; Leigh, James; Holst, Otto; Duda, Katarzyna A

    2012-11-01

    Lipoteichoic acid (LTA) is an amphiphilic polycondensate located in the cell envelope of Gram-positive bacteria. In this study, LTAs were isolated from the three bovine mastitis species Streptococcus uberis 233, Streptococcus dysgalactiae 2023, and Streptococcus agalactiae 0250. Structural investigations of these LTAs were performed applying 1D and 2D nuclear magnetic resonance experiments as well as chemical analyses and mass spectrometry. Compositional analysis revealed the presence of glycerol (Gro), Glc, alanine (Ala), and 16:0, 16:1, 18:0, 18:1. The LTAs of the three Streptococcus strains possessed the same structure, that is, a lipid anchor comprised of α-Glcp-(1→2)-α-Glcp-(1→3)-1,2-diacyl-sn-Gro and the hydrophilic backbone consisting of poly(sn-Gro-1-phosphate) randomly substituted at O-2 of Gro by d-Ala.

  16. Structural analysis of the lipoteichoic acids isolated from bovine mastitis Streptococcus uberis 233, Streptococcus dysgalactiae 2023 and Streptococcus agalactiae 0250.

    PubMed

    Czabańska, Anna; Neiwert, Olga; Lindner, Buko; Leigh, James; Holst, Otto; Duda, Katarzyna A

    2012-11-01

    Lipoteichoic acid (LTA) is an amphiphilic polycondensate located in the cell envelope of Gram-positive bacteria. In this study, LTAs were isolated from the three bovine mastitis species Streptococcus uberis 233, Streptococcus dysgalactiae 2023, and Streptococcus agalactiae 0250. Structural investigations of these LTAs were performed applying 1D and 2D nuclear magnetic resonance experiments as well as chemical analyses and mass spectrometry. Compositional analysis revealed the presence of glycerol (Gro), Glc, alanine (Ala), and 16:0, 16:1, 18:0, 18:1. The LTAs of the three Streptococcus strains possessed the same structure, that is, a lipid anchor comprised of α-Glcp-(1→2)-α-Glcp-(1→3)-1,2-diacyl-sn-Gro and the hydrophilic backbone consisting of poly(sn-Gro-1-phosphate) randomly substituted at O-2 of Gro by d-Ala. PMID:23036931

  17. Antibody binding to Streptococcus mitis and Streptococcus oralis cell fractions

    PubMed Central

    Wirth, Katherine A.; Bowden, George H.; Richmond, Dorothy A.; Sheridan, Michael J.; Cole, Michael F.

    2008-01-01

    Summary Objective To determine which cell fraction(s) of Streptococcus mitis biovar 1 serve as the best source of antigens recognized by salivary SIgA antibodies in infants. Design Whole cells of 38 reference and wild-type isolates of Streptococcus mitis, S. oralis, S. gordonii, Enterococcus casseliflavus, and E. faecalis were fractionated into cell walls CW), protease-treated cell walls (PTCW), cell membranes (CM) and cell protein (CP). Whole cells and these fractions were tested for binding by rabbit anti-S. mitis SK145 and anti-S. oralis SK100 sera, and also by salivary SIgA antibodies from infants and adults. Results Anti-SK145 and anti-SK100 sera bound whole cells and fractions of all strains of S. mitis and S. oralis variably. Cluster analysis of antibody binding data placed the strains into S. mitis, S. oralis and ‘Non-S. mitis/non-S. oralis’ clusters. Antigens from CW and CM best discriminated S. mitis from S. oralis. CM bound the most infant salivary SIgA antibody and PTCW bound the least. In contrast, adult salivary SIgA antibody bound all of the cell fractions and at higher levels. Conclusions Presumably the relatively short period of immune stimulation and immunological immaturity in infants, in contrast to adults, result in low levels of salivary SIgA antibody that preferentially bind CM of S. mitis but not PTCW. By utilizing isolated cell walls and membranes as sources of antigens for proteomics it may be possible to identify antigens common to oral streptococci and dissect the fine specificity of salivary SIgA antibodies induced by oral colonization by S. mitis. PMID:17904095

  18. Antimicrobial susceptibility of Arcanobacterium pyogenes isolated from the lungs of white-tailed deer (Odocoileus virginianus) with pneumonia.

    PubMed

    Tell, Lisa A; Brooks, Jason W; Lintner, Valerie; Matthews, Tammy; Kariyawasam, Subhashinie

    2011-09-01

    In vitro susceptibilities of 29 strains of Arcanobacterium pyogenes isolated from lung lesions of white-tailed deer (Odocoileus virginianus) with pneumonia were determined using the broth microdilution method to ascertain efficacious treatment options for pneumonic white-tailed deer. All 29 A. pyogenes strains tested were susceptible to ceftiofur, spectinomycin, tiamulin, and trimethoprim-sulfamethoxazole but were resistant to both danofloxacin and sulfadimethoxine. Likewise, all 29 isolates were either fully susceptible or intermediately susceptible to gentamicin (25 susceptible; 4 intermediate) and tulathromycin (25 susceptible; 4 intermediate). At least one isolate of A. pyogenes tested was resistant to ampicillin, chlortetracycline, clindamycin, enrofloxacin, florfenicol, oxytetracycline, penicillin, and tilmicosin suggesting their ineffectiveness in treating A. pyogenes-associated lung infections in white-tailed deer. Minimum inhibitory concentration (MIC) data for tylosin and neomycin could not be interpreted due to unavailability of Clinical and Laboratory Standards Institute (CLSI)-approved breakpoints for these 2 agents. In summary, based on MIC values, ceftiofur, spectinomycin, tiamulin, and trimethoprim-sulfamethoxazole are more efficacious than other antimicrobial agents for treating A. pyogenes-related pneumonia in white-tailed deer. However, ceftiofur may be preferred over the other 4 drugs as it is being widely used to treat respiratory disease in cattle and other animal species, as well as is available for single dose parenteral administration. PMID:21908365

  19. Intra-Abdominal Abscess and Primary Peritonitis Caused by Streptococcus anginosus

    PubMed Central

    Terzi, Huseyin Agah; Demiray, Tayfur; Koroglu, Mehmet; Cakmak, Guner; Hakki Ciftci, Ihsan; Ozbek, Ahmet; Altindis, Mustafa

    2016-01-01

    Introduction The Streptococcus anginosus group of bacteria are low-virulence bacteria existing as commensals in the oral flora and gastrointestinal tracts of humans. S. anginosus may spread to the blood in individuals with poor oral hygiene in cases of oral infections, such as gingivitis and tooth abscesses, that develop following the loss of mucosal unity. This may lead to infections in the whole body, primarily as brain and liver abscesses. Case Presentation A 32-year-old male patient presented with complaints of nausea, vomiting, and diffuse abdominal pain. Diffuse abdominal tenderness and rebound tenderness were detected particularly in the epigastrium and right upper quadrant. Laboratory assessment revealed a leukocyte count of 20,500/mm3. Free fluid around the liver and heterogeneous areas of abscess formation in the right lateral gallbladder were revealed on abdominal computed tomography. Diffuse adhesions between the bowel and seropurulent free liquid in the abdomen were detected on surgical exploration, and a sample was taken for cultures. The patient was discharged without complications on the sixth postoperative day and his antibiotic course was completed with 4 weeks of oral treatment. We reviewed the literature for similar cases of disseminated pyogenic infections caused by the S. anginosus group. Conclusions It should be kept in mind that the oral flora bacterium S. anginosus may cause transient bacteremia and deep-seated organ abscesses in immunodeficient patients with poor oral hygiene. Such patients with intra-abdominal abscesses should be treated with antibiotics and surgery. PMID:27630763

  20. Epidemiology of Streptococcus dysgalactiae subsp. equisimilis in tropical communities, Northern Australia.

    PubMed

    McDonald, Malcolm; Towers, Rebecca J; Andrews, Ross M; Carapetis, Jonathan R; Currie, Bart J

    2007-11-01

    Streptococcus dysgalactiae subsp. equisimilis (groups C and G streptococci [GCS/GGS]) is an increasingly recognized human pathogen, although it may follow indirect pathways. Prospective surveillance of selected households in 3 remote Aboriginal communities in Australia provided 337 GCS/GGS isolates that were emm sequence-typed. Lancefield group C isolates (GCS) were localized to specific households and group G isolates (GGS) were more evenly distributed. GCS/GGS was more frequently recovered from the throat than group A streptococci (GAS [S. pyogenes]) but rarely recovered from skin sores, and then only with Staphylococcus aureus or GAS. Symptomatic GGS/GGC pharyngitis was also rare. Specific emm sequence types of GCS/GGS did not appear to cycle through the communities (sequential strain replacement) in a manner suggesting acquisition of type-specific immunity. These communities already have high levels of streptococcal and poststreptococcal disease. GCS/GGS may increase in importance as it acquires key virulence factors from GAS by lateral gene transfer.

  1. Cervical Facet Joint Infection and Associated Epidural Abscess with Streptococcus intermedius from a Dental Infection Origin A Case Report and Review.

    PubMed

    Kaye, Ian David; Protopsaltis, Themistocles S

    2016-09-01

    Pyogenic cervical facet joint infections are rare and such infections from a dental origin are even less common. Of these few cases, none have described infection with Streptococcus intermedius as the pathogen. A 65-year-old orthopaedic surgeon complained of fevers, right-sided radiating neck pain, stiffness, swelling, erythema, and right upper extremity weakness one month after he had broken a crown over his right mandibular premolar, a continued source of pain. Imaging of the cervical spine showed a right C4-C5 facet inflammatory arthropathy and a small epidural abscess that was cultured and initially treated with intravenous antibiotics. The oral maxillofacial surgery team performed an extraction of the infected, symptomatic tooth. For continued right upper extremity weakness, the patient underwent C4-C5 laminoforaminotomy and irrigation and debridement of the right C4-C5 facet joint. After 6 weeks of intravenous antibiotics, the patient's infectious and inflammatory markers had normalized. By 4 months, he had regained full strength at his upper extremity and a painless and full range of motion of his cervical spine.Pyogenic cervical facet joint infection is very rare and potentially dangerous. A high clinical suspicion and appropriate imaging, including magnetic resonance imaging, are important for correct diagnosis. Prompt medical and surgical treatment may avert complications, and although the patient presented made a complete recovery, patients may be left with neurological compromise.

  2. Cervical Facet Joint Infection and Associated Epidural Abscess with Streptococcus intermedius from a Dental Infection Origin A Case Report and Review.

    PubMed

    Kaye, Ian David; Protopsaltis, Themistocles S

    2016-09-01

    Pyogenic cervical facet joint infections are rare and such infections from a dental origin are even less common. Of these few cases, none have described infection with Streptococcus intermedius as the pathogen. A 65-year-old orthopaedic surgeon complained of fevers, right-sided radiating neck pain, stiffness, swelling, erythema, and right upper extremity weakness one month after he had broken a crown over his right mandibular premolar, a continued source of pain. Imaging of the cervical spine showed a right C4-C5 facet inflammatory arthropathy and a small epidural abscess that was cultured and initially treated with intravenous antibiotics. The oral maxillofacial surgery team performed an extraction of the infected, symptomatic tooth. For continued right upper extremity weakness, the patient underwent C4-C5 laminoforaminotomy and irrigation and debridement of the right C4-C5 facet joint. After 6 weeks of intravenous antibiotics, the patient's infectious and inflammatory markers had normalized. By 4 months, he had regained full strength at his upper extremity and a painless and full range of motion of his cervical spine.Pyogenic cervical facet joint infection is very rare and potentially dangerous. A high clinical suspicion and appropriate imaging, including magnetic resonance imaging, are important for correct diagnosis. Prompt medical and surgical treatment may avert complications, and although the patient presented made a complete recovery, patients may be left with neurological compromise. PMID:27620549

  3. A plasmid in Streptococcus pneumoniae.

    PubMed Central

    Smith, M D; Guild, W R

    1979-01-01

    Plasmid deoxyribonucleic acid has been detected in three related laboratory strains of Streptococcus pneumoniae. Strains D39S, R36, and R36NC each contain a minimum of two copies per cell of a 2.0-megadalton plasmid (pDP1). A plasmid twice as large as this smaller one is also present in much lower quantity in these strains, but neither plasmid is present in four strains related to these or in a drug-resistant clinical isolate from Paris. The plasmid yield was not amplified in the presence of chloramphenicol. No phenotype has been correlated with the presence of pDP1, which has existed in strains carried for many years in laboratory collections. Images PMID:33961

  4. Safety assessment of dairy microorganisms: Streptococcus thermophilus.

    PubMed

    Delorme, Christine

    2008-09-01

    Streptococcus thermophilus is a major dairy starter used in yogurt and cheese production. In Streptococcus genus, S. thermophilus is the only one food species among commensal and opportunistic pathogen species. Comparative genomics suggest that this species recently emerged and evolved by combination of loss-of-function and horizontal gene transfer events. These gene transfer events detected in S. thermophilus have originated from other dairy species and might contribute to its adaptation to the milk environment.

  5. Infections Associated with Streptococcus intermedius in Children.

    PubMed

    Faden, Howard S

    2016-09-01

    Streptococcus intermedius is a viridans Streptococcus belonging to the Anginosus group. In the past 7 years, it has been associated