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1

Frequency of serotypes of Streptococcus pyogenes in different diseases  

PubMed Central

During an 18-month period 1,002 strains of Streptococcus pyogenes, consecutively isolated in the laboratory from a wide variety of lesions, were typed by the precipitin and slide-agglutination tests. The relative frequency of serotypes in different diseases was examined and a close association between type 4 in scarlet fever and type 3.13 in impetigo noted. An apparent lack of any relationship between particular serotypes and streptococcal sore throat was evident. The difficulty of distinguishing the more virulent types of Str. pyogenes and correlating a type-specific disease relationship is discussed. PMID:14474621

Mitchell, E. S.

1962-01-01

2

[Streptococcus pyogenes pathogenic factors].  

PubMed

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

Bidet, Ph; Bonacorsi, S

2014-11-01

3

Erythromycin resistance in Streptococcus pyogenes in Italy.  

PubMed Central

In a prospective study of acute pharyngitis in Italian children, 69 (38.3%) of 180 isolates of Streptococcus pyogenes were resistant to macrolides. S. pyogenes was eradicated in 12 (63.1%) of 19 patients with erythromycin-resistant S. pyogenes treated with clarithromycin and in 22 (88%) of 25 patients with erythromycin-susceptible strains. The constitutive-resistant phenotype was correlated with failure of macrolide treatment. PMID:10756153

Bassetti, M.; Manno, G.; Collidà, A.; Ferrando, A.; Gatti, G.; Ugolotti, E.; Cruciani, M.; Bassetti, D.

2000-01-01

4

Surface interactome in Streptococcus pyogenes.  

PubMed

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

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

2012-04-01

5

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

PubMed Central

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

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

2012-01-01

6

The FbaB-type fibronectin-binding protein of Streptococcus pyogenes promotes specific invasion  

E-print Network

The FbaB-type fibronectin-binding protein of Streptococcus pyogenes promotes specific invasion3 Streptococcus pyogenes are among the most frequently isolated organisms from patients suffering of invasive S. pyogenes iso- lates into the vascular EC lining. Introduction Streptococcus pyogenes (group

Nizet, Victor

7

CRISPR Inhibition of Prophage Acquisition in Streptococcus pyogenes  

Microsoft Academic Search

Streptococcus pyogenes, one of the major human pathogens, is a unique species since it has acquired diverse strain-specific virulence properties mainly through the acquisition of streptococcal prophages. In addition, S. pyogenes possesses clustered regularly interspaced short palindromic repeats (CRISPR)\\/Cas systems that can restrict horizontal gene transfer (HGT) including phage insertion. Therefore, it was of interest to examine the relationship between

Takashi Nozawa; Nayuta Furukawa; Chihiro Aikawa; Takayasu Watanabe; Bijaya Haobam; Ken Kurokawa; Fumito Maruyama; Ichiro Nakagawa

2011-01-01

8

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

E-print Network

Streptococcus pyogenes Strain SF370 Carola Venturini,a Cheryl-lynn Y. Ong,a Christine M. Gillen,a Nouri L. Ben of California--San Diego, La Jolla, California, USAb The resurgence of invasive disease caused by Streptococcus pyogenes (group A Streptococcus [GAS]) in the past 30 years has par- alleled the emergence and global

Nizet, Victor

9

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

PubMed

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

2003-12-01

10

Chemokine-cleaving Streptococcus pyogenes protease SpyCEP is necessary and sufficient for bacterial  

E-print Network

Chemokine-cleaving Streptococcus pyogenes protease SpyCEP is necessary and sufficient for bacterial, University of California at San Diego, La Jolla, CA 92093, USA. Summary SpyCEP is a Streptococcus pyogenes and also underlies dissemination in the respiratory tract. Introduction Streptococcus pyogenes causes

Nizet, Victor

11

The CXC Chemokine-degrading Protease SpyCep of Streptococcus pyogenes Promotes Its Uptake  

E-print Network

The CXC Chemokine-degrading Protease SpyCep of Streptococcus pyogenes Promotes Its Uptake, San Diego, La Jolla, California 92093 Streptococcus pyogenes expresses the LPXTG motif-contain- ing protein into human endothe- lial cells. Streptococcus pyogenes is an important human pathogen able

Nizet, Victor

12

Is Streptococcus pyogenes Resistant or Susceptible to Trimethoprim-Sulfamethoxazole?  

PubMed Central

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 ?-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

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

2012-01-01

13

The role of coagulation/fibrinolysis during Streptococcus pyogenes infection.  

PubMed

The hemostatic system comprises platelet aggregation, coagulation and fibrinolysis and is a host defense mechanism that protects the integrity of the vascular system after tissue injury. During bacterial infections, the coagulation system cooperates with the inflammatory system to eliminate the invading pathogens. However, pathogenic bacteria have frequently evolved mechanisms to exploit the hemostatic system components for their own benefit. Streptococcus pyogenes, also known as Group A Streptococcus, provides a remarkable example of the extraordinary capacity of pathogens to exploit the host hemostatic system to support microbial survival and dissemination. The coagulation cascade comprises the contact system (also known as the intrinsic pathway) and the tissue factor pathway (also known as the extrinsic pathway), both leading to fibrin formation. During the early phase of S. pyogenes infection, the activation of the contact system eventually leads to bacterial entrapment within a fibrin clot, where S. pyogenes is immobilized and killed. However, entrapped S. pyogenes can circumvent the antimicrobial effect of the clot by sequestering host plasminogen on the bacterial cell surface that, after conversion into its active proteolytic form, plasmin, degrades the fibrin network and facilitates the liberation of S. pyogenes from the clot. Furthermore, the surface-localized fibrinolytic activity also cleaves a variety of extracellular matrix proteins, thereby enabling S. pyogenes to migrate across barriers and disseminate within the host. This review summarizes the knowledge gained during the last two decades on the role of coagulation/fibrinolysis in host defense against S. pyogenes as well as the strategies developed by this pathogen to evade and exploit these host mechanisms for its own benefit. PMID:25309880

Loof, Torsten G; Deicke, Christin; Medina, Eva

2014-01-01

14

Inactivation of DltA Modulates Virulence Factor Expression in Streptococcus pyogenes  

E-print Network

Inactivation of DltA Modulates Virulence Factor Expression in Streptococcus pyogenes Kathleen H the effects that mutating dltA has on virulence factor expression in Streptococcus pyogenes. Methodology/Significance: This study has identified a novel mechanism for the reduced virulence of dltA mutants of Streptococcus

Nizet, Victor

15

Closed Genome Sequence of Noninvasive Streptococcus pyogenes M/emm3 Strain STAB902  

E-print Network

Closed Genome Sequence of Noninvasive Streptococcus pyogenes M/emm3 Strain STAB902 Nicolas Soriano Rennes 1, Rennes, Franced We report a closed genome sequence of group A Streptococcus genotype emm3 (GAS. Closed genome sequence of noninvasive Streptococcus pyogenes M/emm3 strain STAB902. Genome Announc. 2

Paris-Sud XI, Université de

16

In Vitro Antibacterial Activity of Essential Oils against Streptococcus pyogenes  

PubMed Central

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

Sfeir, Julien; Lefrançois, Corinne; Baudoux, Dominique; Derbré, Séverine; Licznar, Patricia

2013-01-01

17

Protein F, a Fibronectin-Binding Protein, is an Adhesin of the Group A Streptococcus Streptococcus pyogenes  

Microsoft Academic Search

Binding to fibronectin has been suggested to play an important role in adherence of the group A streptococcus Streptococcus pyogenes to host epithelial cells; however, the identity of the streptococcal fibronectin receptor has been elusive. Here we demonstrate that the fibronectin-binding property of S. pyogenes is mediated by protein F, a bacterial surface protein that binds fibronectin at high affinity.

Emanuel Hanski; Michael Caparon

1992-01-01

18

Sterilization of Streptococcus pyogenes by afterglow dielectric barrier discharge using O 2 and CO 2 working gases  

Microsoft Academic Search

Streptococcus pyogenes is a causative agent in wide range of human diseases. To inactivate S. pyogenes by the afterglow of a dielectric barrier discharge (DBD), we prepared suspensions of the cultured bacterium in liquid (with concentrations of OD600nm=0.25 McFarland standard) and solid (with 7.75×105 spread cells per surface plate) Luria–Bertini (LB) broth media. The influence of DBD exposure on S.

Abasalt Hosseinzadeh Colagar; Farshad Sohbatzadeh; Saeed Mirzanejhad; Azadeh Valinataj Omran

2010-01-01

19

Factors That Cause Trimethoprim Resistance in Streptococcus pyogenes  

PubMed Central

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

Bergmann, René; van der Linden, Mark; Chhatwal, Gursharan S.

2014-01-01

20

Novel Bacteriophage Lysin with Broad Lytic Activity Protects against Mixed Infection by Streptococcus pyogenes and Methicillin-Resistant Staphylococcus aureus  

PubMed Central

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 ?g/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 ?g/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. PMID:23571534

Gilmer, Daniel B.; Schmitz, Jonathan E.; Euler, Chad W.

2013-01-01

21

Inhibition of Streptococcus pyogenes Biofilm Formation by Coral-Associated Actinomycetes  

Microsoft Academic Search

Streptococcus pyogenes biofilms tend to exhibit significant tolerance to antimicrobials during infections. We screened coral-associated actinomycetes\\u000a (CAA) for antibiofilm activity against different biofilm forming M serotype of Streptococcus pyogenes. Actinomycetes isolated from the mucus of the coral Acropora digitifera were screened for antibiofilm activity against S. pyogenes biofilms wherein several isolates clearly demonstrated antibiofilm activity. The biofilm inhibitory concentrations (BICs)

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

2010-01-01

22

Opacity Factor Activity and Epithelial Cell Binding by the Serum Opacity Factor Protein of Streptococcus pyogenes Are  

E-print Network

of Streptococcus pyogenes Are Functionally Discrete*S Received for publication,August 14, 2007, and in revised form determinant expressed at the surface of Streptococcus pyo- genes and has been shown to elicit protective to the FnBD alone. Streptococcus pyogenes (group A streptococcus, GAS)4 is an important human pathogen

Nizet, Victor

23

Specific Interactions between F1 Adhesin of Streptococcus pyogenes and N-terminal Modules of Fibronectin*  

E-print Network

Specific Interactions between F1 Adhesin of Streptococcus pyogenes and N-terminal Modules Protein F1 is a surface protein of Streptococcus pyo- genes that mediates high affinity binding fasciitis, and sepsis (8). Re- cent studies showed that Group A streptococcus is capable of inducing its own

Mosher, Deane F.

24

Transcriptional analysis of the Streptococcus pyogenes salivaricin locus.  

PubMed

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

Namprachan-Frantz, Phanramphoei; Rowe, Hannah M; Runft, Donna L; Neely, Melody N

2014-02-01

25

A novel adaptation of aldolase regulates virulence in Streptococcus pyogenes  

PubMed Central

Regulation of virulence factor expression is critical for pathogenic microorganisms that must sense and adapt to a dynamic host environment; yet, the signal transduction pathways that enable this process are generally poorly understood. Here, we identify LacD.1 as a global regulator of virulence factor expression in the versatile human pathogen, Streptococcus pyogenes. LacD.1 is derived from a class I tagatose-1,6-bisphosphate aldolase homologous to those involved in lactose and galactose metabolism in related prokaryotes. However, regulation of transcription by LacD.1 is not dependent on this enzymatic activity or the canonical catabolite repression pathway, but likely does require substrate recognition. Our results suggest that LacD.1 has been adapted as a metabolic sensor, and raise the possibility that regulation of gene expression by metabolic enzymes may be a novel mechanism by which Gram-positive bacteria, including S. pyogenes, coordinate multiple environmental cues, allowing essential transcription programs to be coupled with perceived nutritional status. PMID:17066081

Loughman, Jennifer A; Caparon, Michael G

2006-01-01

26

Transcriptional Analysis of the Streptococcus pyogenes Salivaricin Locus  

PubMed Central

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

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

2014-01-01

27

Complete genome of acute rheumatic fever-associated serotype M5 Streptococcus pyogenes strain manfredo.  

PubMed

Comparisons of the 1.84-Mb genome of serotype M5 Streptococcus pyogenes strain Manfredo with previously sequenced genomes emphasized the role of prophages in diversification of S. pyogenes and the close relationship between strain Manfredo and MGAS8232, another acute rheumatic fever-associated strain. PMID:17012393

Holden, Matthew T G; Scott, Annabel; Cherevach, Inna; Chillingworth, Tracey; Churcher, Carol; Cronin, Ann; Dowd, Linda; Feltwell, Theresa; Hamlin, Nancy; Holroyd, Simon; Jagels, Kay; Moule, Sharon; Mungall, Karen; Quail, Michael A; Price, Claire; Rabbinowitsch, Ester; Sharp, Sarah; Skelton, Jason; Whitehead, Sally; Barrell, Bart G; Kehoe, Michael; Parkhill, Julian

2007-02-01

28

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

PubMed Central

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

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

2013-01-01

29

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

PubMed

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. PMID:24837509

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

2014-06-24

30

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

PubMed

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

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

31

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

PubMed Central

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

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

2010-01-01

32

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

Microsoft Academic Search

The hemolytic Streptococcus pyogenes can use a variety of heme compounds as an iron source. In this study, we investigate hemoprotein utilization by S. pyogenes. We demonstrate that surface proteins contribute to the binding of hemoproteins to S. pyogenes. We identify an ABC transporter from the iron complex family named sia for streptococcal iron acquisition, which consists of a lipoprotein

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

2003-01-01

33

Growth phase-associated changes in the transcriptome and proteome of Streptococcus pyogenes  

Microsoft Academic Search

Streptococcus pyogenes is responsible for approximately 500,000 deaths each year worldwide. Many of the associated virulence factors are expressed\\u000a in a growth phase-dependent manner. To identify growth phase-associated changes in expression on a genomescale, the exponential\\u000a and stationary phase transcriptomes and proteomes of S. pyogenes strain NZ131 (serotype M49) were compared by using Affymetrix NimbleExpress gene chips and two-dimensional gel

Michelle A. Chaussee; Alexander V. Dmitriev; Eduardo A. Callegari; Michael S. Chaussee

2008-01-01

34

Identification of Rgg Binding Sites in the Streptococcus pyogenes Chromosome ? †  

PubMed Central

Streptococcus pyogenes Rgg is a regulatory protein that controls the transcription of 588 genes in strain NZ131 during the post-exponential phase of growth, including the virulence-associated genes encoding the extracellular SpeB protease, pullulanase A (PulA), and two extracellular nucleases (SdaB and Spd-3). Rgg binds to DNA proximally to the speB promoter (PspeB) to activate transcription; however, it is not known if Rgg binds to the promoters of other genes to influence expression, or if the perturbation of other global regulons accounts for the genome-wide changes in expression associated with the mutant. To address this issue, chromatin immunoprecipitation followed by DNA microarray analysis (ChIP-chip) was used to identify the DNA binding sites of Rgg. Rgg bound to 65 sites in the chromosome. Thirty-five were within noncoding DNA, and 43% of these were adjacent to genes previously identified as regulated by Rgg. Electrophoretic mobility shift assays were used to assess the binding of Rgg to a subset of sites bound in vivo, including the noncoding DNA upstream of speB, the genes encoding PulA, Spd-3, and a transcriptional regulator (SPY49_1113), and prophage-associated genes encoding a putative integrase (SPY49_0746) and a surface antigen (SPY49_0396). Rgg bound to all target DNAs in vitro, consistent with the in vivo results. Finally, analyses with a transcriptional reporter system showed that the DNA bound by Rgg contained an active promoter that was regulated by Rgg. Overall, the results indicate that Rgg binds specifically to multiple sites in the chromosome, including prophage DNA, to influence gene expression. PMID:21764942

Anbalagan, Srivishnupriya; McShan, W. Michael; Dunman, Paul M.; Chaussee, Michael S.

2011-01-01

35

Mechanism and regulation of phosphate transport in Streptococcus pyogenes  

SciTech Connect

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.

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

1987-01-01

36

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

PubMed Central

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

2012-01-01

37

Antimicrobial susceptibility patterns, emm type distribution and genetic diversity of Streptococcus pyogenes recovered in Brazil.  

PubMed

Streptococcus pyogenes is responsible for a variety of infectious diseases and immunological complications. In this study, 91 isolates of S. pyogenes recovered from oropharynx secretions were submitted to antimicrobial susceptibility testing, emm typing and pulsed-field gel electrophoresis (PFGE) analysis. All isolates were susceptible to ceftriaxone, levofloxacin, penicillin G and vancomycin. Resistance to erythromycin and clindamycin was 15.4%, which is higher than previous reports from this area, while 20.9% of the isolates were not susceptible to tetracycline. The macrolide resistance phenotypes were cMLSB (10) and iMLSB (4). The ermB gene was predominant, followed by the ermA gene. Thirty-two emm types and subtypes were found, but five (emm1, emm4, emm12, emm22, emm81) were detected in 48% of the isolates. Three new emm subtypes were identified (emm1.74, emm58.14, emm76.7). There was a strong association between emm type and PFGE clustering. A variety of PFGE profiles as well as emm types were found among tetracycline and erythromycin-resistant isolates, demonstrating that antimicrobial resistant strains do not result from the expansion of one or a few clones. This study provides epidemiological data that contribute to the development of suitable strategies for the prevention and treatment of such infections in a poorly studied area. PMID:25410998

Arêas, Glauber P; Schuab, Rôde B B; Neves, Felipe P G; Barros, Rosana R

2014-11-01

38

Antimicrobial susceptibility patterns, emm type distribution and genetic diversity of Streptococcus pyogenes recovered in Brazil.  

PubMed

Streptococcus pyogenes is responsible for a variety of infectious diseases and immunological complications. In this study, 91 isolates of S. pyogenes recovered from oropharynx secretions were submitted to antimicrobial susceptibility testing, emm typing and pulsed-field gel electrophoresis (PFGE) analysis. All isolates were susceptible to ceftriaxone, levofloxacin, penicillin G and vancomycin. Resistance to erythromycin and clindamycin was 15.4%, which is higher than previous reports from this area, while 20.9% of the isolates were not susceptible to tetracycline. The macrolide resistance phenotypes were cMLSB (10) and iMLSB (4). The ermB gene was predominant, followed by the ermA gene. Thirty-two emm types and subtypes were found, but five (emm1, emm4, emm12, emm22, emm81) were detected in 48% of the isolates. Three new emm subtypes were identified (emm1.74, emm58.14, emm76.7). There was a strong association between emm type and PFGE clustering. A variety of PFGE profiles as well as emm types were found among tetracycline and erythromycin-resistant isolates, demonstrating that antimicrobial resistant strains do not result from the expansion of one or a few clones. This study provides epidemiological data that contribute to the development of suitable strategies for the prevention and treatment of such infections in a poorly studied area. PMID:25351379

Arêas, Glauber P; Schuab, Rôde Bb; Neves, Felipe Pg; Barros, Rosana R

2014-10-28

39

Multilocus Sequence Typing of Streptococcus pyogenes and the Relationships between emm Type and Clone  

Microsoft Academic Search

Multilocus sequence typing (MLST) is a tool that can be used to study the molecular epidemiology and population genetic structure of microorganisms. A MLST scheme was developed for Streptococcus pyogenes and the nucleotide sequences of internal fragments of seven selected housekeeping loci were obtained for 212 isolates. A total of 100 unique combinations of housekeeping alleles (allelic profiles) were identified.

MARK C. ENRIGHT; BRIAN G. SPRATT; AWDHESH KALIA; JOHN H. CROSS; D. E. Bessen

2001-01-01

40

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

PubMed

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. PMID:23994376

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

41

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

PubMed

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

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

2014-09-01

42

Streptokinase variants from Streptococcus pyogenes isolates display altered plasminogen activation characteristics - implications for pathogenesis.  

PubMed

Streptococcus pyogenes (group A streptococcus, GAS) secretes streptokinase, a potent plasminogen activating protein. Among GAS isolates, streptokinase gene sequences (ska) are polymorphic and can be grouped into two distinct sequence clusters (termed cluster type-1 and cluster type-2) with cluster type-2 being further divided into sub-clusters type-2a and type-2b. In this study, far-UV circular dichroism spectroscopy indicated that purified streptokinase variants of each type displayed similar secondary structure. Type-2b streptokinase variants could not generate an active site in Glu-plasminogen through non-proteolytic mechanisms while all other variants had this capability. Furthermore, when compared with other streptokinase variants, type-2b variants displayed a 29- to 35-fold reduction in affinity for Glu-plasminogen. All SK variants could activate Glu-plasminogen when an activator complex was preformed with plasmin; however, type-2b and type-1 complexes were inhibited by ?(2) -antiplasmin. Exchanging ska(type-2a) in the M1T1 GAS strain 5448 with ska(type-2b) caused a reduction in virulence while exchanging ska(type-2a) with ska(type-1) into 5448 produced an increase in virulence when using a mouse model of invasive disease. These findings suggest that streptokinase variants produced by GAS isolates utilize distinct plasminogen activation pathways, which directly affects the pathogenesis of this organism. PMID:23106864

Cook, Simon M; Skora, Amanda; Gillen, Christine M; Walker, Mark J; McArthur, Jason D

2012-12-01

43

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

PubMed Central

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

Nguyen, Scott V.; McShan, William M.

2014-01-01

44

Streptococcus pyogenes degrades extracellular matrix in chondrocytes via MMP-13  

SciTech Connect

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.

Sakurai, Atsuo [Division of Bacteriology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Okahashi, Nobuo [Oral Frontier Biology, Osaka University Graduate School of Dentistry, Suita-Osaka 565-0871 (Japan); Maruyama, Fumito [Division of Bacteriology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Ooshima, Takashi [Pediatric Dentistry, Osaka University Graduate School of Dentistry, Suita-Osaka 565-0871 (Japan); Hamada, Shigeyuki [Advanced Research Institute for the Sciences and Humanities, Nihon University, 6F Ichigaya Tokyu Building, 2-1 Kudan-kita 4-chome, Chiyoda-ku, Tokyo 102-0073 (Japan); Nakagawa, Ichiro [Division of Bacteriology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan)], E-mail: ichiro-n@ims.u-tokyo.ac.jp

2008-08-29

45

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

PubMed Central

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

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

2005-01-01

46

Effect of subinhibitory concentrations of fluoroquinolones on biofilm production by clinical isolates of Streptococcus pyogenes  

PubMed Central

Background & objectives: Subinhibitory concentrations (sub-MICs) of antibiotics, although not able to kill bacteria, but influence bacterial virulence significantly. Fluoroquinolones (FQs) which are used against other bacterial pathogens creates resistance in non-targeted Streptococcus pyogenes. This study was undertaken to characterize the effect of sub-MICs of FQs on S. pyogenes biofilm formation. Methods: Biofilm forming six M serotypes M56, st38, M89, M65, M100 and M74 of S. pyogenes clinical isolates were challenged against four FQs namely, ciprofloxacin, ofloxacin, levofloxacin and norfloxacin. The antibiofilm potential of these FQs was analysed at their subinhibitory concentrations (1/2 to 1/64 MIC) using biofilm assay, XTT reduction assay, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Results: Among the four FQs tested, ofloxacin and levofloxacin at 1/2 MIC showed the maximum inhibition (92%) of biofilm formation against M56 and M74 serotypes. FQs effectively interfered in the microcolony formation of S. pyogenes isolates at 1/2 to 1/8 sub-MICs. Inhibition of biofilm formation was greatly reduced beyond 1/16 MICs and allowed biofilm formation. XTT reduction assay revealed the increase in metabolic activity of S. pyogenes biofilm against the decrease in FQs concentration. SEM and CLSM validated the potential of sub-MICs of FQs against the six S. pyogenes. Interpretation & conclusions: Our results showed that the inhibitory effect all four FQs on S. pyogenes biofilm formation was concentration dependent. FQs at proper dosage can be effective against S. pyogenes and lower concentrations may allow the bacteria to form barriers against the antibiotic in the form of biofilm. PMID:23760384

Balaji, Kannan; Thenmozhi, Ramalingam; Pandian, Shunmugiah Karutha

2013-01-01

47

First Streptococcus pyogenes Signature-Tagged Mutagenesis Screen Identifies Novel Virulence Determinants?  

PubMed Central

The virulence of bacterial pathogens is a complex process that requires the dynamic expression of many genes for the pathogens to invade and circumvent host defenses, as well as to proliferate in vivo. In this study, we employed a large-scale screen, signature-tagged mutagenesis (STM), to identify Streptococcus pyogenes virulence genes important for pathogenesis within the host. Approximately 1,200 STM mutants were created and screened using the zebrafish infectious disease model. The transposon insertion site was identified for 29 of the 150 mutants that were considered attenuated for virulence. Previously reported streptococcal virulence genes, such as mga, hasA, amrA, smeZ, and two genes in the sil locus, were identified, confirming the utility of the model for revealing genes important for virulence. Multiple genes not previously implicated in virulence were also identified, including genes encoding putative transporters, hypothetical cytosolic proteins, and macrolide efflux pumps. The STM mutant strains display various levels of attenuation, and multiple separate insertions were identified in either the same gene or the same locus, suggesting that these factors are important for this type of acute, invasive infection. We further examined two such genes, silB and silC of a putative quorum-sensing regulon, and determined that they are significant virulence factors in our model of necrotizing fasciitis. sil locus promoter expression was examined under various in vitro conditions, as well as in zebrafish tissues, and was found to be differentially induced. This study was a unique investigation of S. pyogenes factors required for successful invasive infection. PMID:19223485

Kizy, Anne E.; Neely, Melody N.

2009-01-01

48

Serine/Threonine Protein Kinase Stk Is Required for Virulence, Stress Response, and Penicillin Tolerance in Streptococcus pyogenes?  

PubMed Central

Genes encoding one or more Ser/Thr protein kinases have been identified recently in many bacteria, including one (stk) in the human pathogen Streptococcus pyogenes (group A streptococcus [GAS]). We report that in GAS, stk is required to produce disease in a murine myositis model of infection. Using microarray and quantitative reverse transcription-PCR (qRT-PCR) studies, we found that Stk activates genes for virulence factors, osmoregulation, metabolism of ?-glucans, and fatty acid biosynthesis, as well as genes affecting cell wall synthesis. Confirming these transcription studies, we determined that the stk deletion mutant is more sensitive to osmotic stress and to penicillin than the wild type. We discuss several possible Stk phosphorylation targets that might explain Stk regulation of expression of specific operons and the possible role of Stk in resuscitation from quiescence. PMID:21788381

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

2011-01-01

49

Complete genome sequence of an M1 strain of Streptococcus pyogenes  

Microsoft Academic Search

The 1,852,442-bp sequence of an M1 strain of Streptococcus pyo- genes, a Gram-positive pathogen, has been determined and con- tains 1,752 predicted protein-encoding genes. Approximately one- third of these genes have no identifiable function, with the remainder falling into previously characterized categories of known microbial function. Consistent with the observation that S. pyogenes is responsible for a wider variety of

Joseph J. Ferretti; William M. McShan; Dragana Ajdic; Dragutin J. Savic; Gorana Savic; Kevin Lyon; Charles Primeaux; Steven Sezate; Alexander N. Suvorov; Steve Kenton; Hong Shing Lai; Shao Ping Lin; Yudong Qian; Hong Gui Jia; Fares Z. Najar; Qun Ren; Hua Zhu; Lin Song; Jim White; Xiling Yuan; Sandra W. Clifton; Bruce A. Roe; Robert McLaughlin

2001-01-01

50

Alteration Of The Chemical Composition Of Human Immunoglobulin G By Streptococcus Pyogenes  

Microsoft Academic Search

Streptococcus pyogenes type 12, isolated from the pharynx of a patient with acute post- streptococcal glomerulonephritis, was subcultured in Todd-Hewitt broth and incubated at 37°C for 24 hr. The organisms were removed by centrifugation and washed with Dulbecco's solution, and serial dilutions were plated on blood-agar plates; 1 ml of suspension containing 3 x 104 organisms was used for treatment

RAWLE M. MCINTOSH; CLAUDIUS KULVINSKAS; DONALD B. KAUFMAN

1971-01-01

51

Non-Invasive Monitoring of Streptococcus pyogenes Vaccine Efficacy Using Biophotonic Imaging  

PubMed Central

Streptococcus pyogenes infection of the nasopharynx represents a key step in the pathogenic cycle of this organism and a major focus for vaccine development, requiring robust models to facilitate the screening of potentially protective antigens. One antigen that may be an important target for vaccination is the chemokine protease, SpyCEP, which is cell surface-associated and plays a role in pathogenesis. Biophotonic imaging (BPI) can non-invasively characterize the spatial location and abundance of bioluminescent bacteria in vivo. We have developed a bioluminescent derivative of a pharyngeal S. pyogenes strain by transformation of an emm75 clinical isolate with the luxABCDE operon. Evaluation of isogenic recombinant strains in vitro and in vivo confirmed that bioluminescence conferred a growth deficit that manifests as a fitness cost during infection. Notwithstanding this, bioluminescence expression permitted non-invasive longitudinal quantitation of S. pyogenes within the murine nasopharynx albeit with a detection limit corresponding to approximately 105 bacterial colony forming units (CFU) in this region. Vaccination of mice with heat killed streptococci, or with SpyCEP led to a specific IgG response in the serum. BPI demonstrated that both vaccine candidates reduced S. pyogenes bioluminescence emission over the course of nasopharyngeal infection. The work suggests the potential for BPI to be used in the non-invasive longitudinal evaluation of potential S. pyogenes vaccines. PMID:24278474

Alam, Faraz M.; Bateman, Colin; Turner, Claire E.; Wiles, Siouxsie; Sriskandan, Shiranee

2013-01-01

52

1116 | VOL.10 NO.11 | NOVEMBER2013 | nAture methods the cas9 protein from the Streptococcus pyogenes crisPr-cas  

E-print Network

the Streptococcus pyogenes crisPr-cas acquired immune system has been adapted for both rnA-guided genome editing from Streptococcus thermophilus CRISPR1 and N. meningitidis (ST1 and NM, respectively) and the large

Cai, Long

53

Transduction of the Streptococcus pyogenes bacteriophage ?m46.1, carrying resistance genes mef(A) and tet(O), to other Streptococcus species  

PubMed Central

?m46.1 – 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. ?m46.1 is transferable in vitro among S. pyogenes isolates, but no information is available about its transferability to other Streptococcus species. We thus investigated ?m46.1 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 ?m46.1 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 ?m46.1 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 ?m46.1 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.

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

2014-01-01

54

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

PubMed

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. PMID:24002218

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

2014-02-01

55

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

PubMed Central

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

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

2012-01-01

56

Potentiation of opsonization and phagocytosis of Streptococcus pyogenes following growth in the presence of clindamycin.  

PubMed

Streptococcus pyogenes, bearing M-protein on its surface, resists opsonization by normal human serum and subsequent phagocytosis by human polymorphonuclear leukocytes. Previous studies have shown that M-protein positive organisms are poorly opsonized by the alternate pathway of complement. In an attempt to define further the role of the surface components of S. pyogenes in this process, we examined the ability of clindamycin, an antibiotic that inhibits protein biosynthesis, to alter bacterial opsonization. An M-protein positive strain of S. pyogenes was grown in varying concentrations of clindamycin at levels lower than those which inhibited growth, i.e., at levels less than the minimal inhibitory concentration. These bacteria were incubated with purified human polymorphonuclear leukocytes and peripheral blood monocytes. Significant enhancement of bacterial opsonization, phagocytosis, and killing resulted. Measurement of complement consumption and binding of the third component of complement (C3) onto the bacterial surface demonstrated that organisms grown in the presence of clindamycin activated complement more readily and fixed more C3 on their surface. Electron microscopy revealed the probable basis for these findings. Streptococci exposed to clindamycin during growth were largely denuded of surface "fuzz," the hairlike structures bearing M-protein. We conclude that the incorporation of clindamycin at concentrations that fail to inhibit growth of S. pyogenes nevertheless causes significant changes in the capacity of these bacteria to resist opsonization by serum complement. These findings support the hypothesis that M-protein inhibits bacterial opsonization by interfering with effective complement activation on the bacterial surface. PMID:7014632

Gemmell, C G; Peterson, P K; Schmeling, D; Kim, Y; Mathews, J; Wannamaker, L; Quie, P G

1981-05-01

57

Antibiotic susceptibility of streptococcus pyogenes isolated from respiratory tract infections in dakar, senegal.  

PubMed

Group A Streptococcus (GAS) is one of the major causes of respiratory tract infections. The objectives of this study were to identify isolates of S. pyogenes obtained from respiratory tract infections, and to assess their susceptibility to several antibiotics. A total of 40 strains were isolated and their susceptibility to 17 antibiotics was tested using a standard disk diffusion method. The minimum inhibitory concentrations (MICs) were determined using the E-test. All isolates were sensitive to ?-lactam antibiotics including penicillin, amoxicillin, and cephalosporins. Macrolides remain active with the exception of spiramycin, which showed reduced susceptibility. Out of the 40 isolates, 100% of the isolates were resistant to tetracycline. Interestingly, isolates were sensitive to chloramphenicol, teicoplanin, vancomycine, and levofloxacin, providing potential alternative choices of treatment against infections with S. pyogenes. PMID:24826076

Camara, Makhtar; Dieng, Assane; Boye, Cheikh Saad Bouh

2013-01-01

58

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

PubMed

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 ?M 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 ?M for 120 min, compared to the control group in which only 10% of the cells aggregated, this was also shown to be statistically significant. PMID:22591139

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

2012-08-01

59

Antibiotic Susceptibility of Streptococcus Pyogenes Isolated from Respiratory Tract Infections in Dakar, Senegal  

PubMed Central

Group A Streptococcus (GAS) is one of the major causes of respiratory tract infections. The objectives of this study were to identify isolates of S. pyogenes obtained from respiratory tract infections, and to assess their susceptibility to several antibiotics. A total of 40 strains were isolated and their susceptibility to 17 antibiotics was tested using a standard disk diffusion method. The minimum inhibitory concentrations (MICs) were determined using the E-test. All isolates were sensitive to ?-lactam antibiotics including penicillin, amoxicillin, and cephalosporins. Macrolides remain active with the exception of spiramycin, which showed reduced susceptibility. Out of the 40 isolates, 100% of the isolates were resistant to tetracycline. Interestingly, isolates were sensitive to chloramphenicol, teicoplanin, vancomycine, and levofloxacin, providing potential alternative choices of treatment against infections with S. pyogenes. PMID:24826076

Camara, Makhtar; Dieng, Assane; Boye, Cheikh Saad Bouh

2013-01-01

60

M protein-associated adherence of Streptococcus pyogenes to epithelial surfaces: prerequisite for virulence.  

PubMed

Virulent strains of Streptococcus pyogenes containing M protein were found to adhere well to human cheek epithelial cells in vitro, whereas an avirulent M - mutant strain adhered feebly. Pretreatment of M + strains with trypsin to remove their M protein surface coating or reacting them with type-specific antiserum markedly impaired their abilities to attach to epithelial cells. Electron microscopy revealed that the attachment of an M + strain to germfree rat epithelial cells was mediated by a fuzzy surface structure previously shown to contain M protein. When mixtures of streptomycin-resistant M + and M - strains were introduced into the mouths of mice, the proportions of the M + strain increased on tongue and cheek surfaces relative to its M - mutant. These data indicate that the surface fuzz of S. pyogenes which contains M protein functions in the attachment of the organism to epithelial surfaces, thereby permitting its colonization. PMID:4564883

Ellen, R P; Gibbons, R J

1972-05-01

61

A new closed-tube multiplex real-time PCR to detect eleven superantigens of Streptococcus pyogenes identifies a strain without superantigen activity.  

PubMed

Superantigens (SAgs) are very potent microbial toxins that are involved in severe diseases such as necrotizing fasciitis and toxic shock syndrome. There are currently 11 different SAgs that have been identified from Streptococcus pyogenes. In the present study, two sets of multiplex PCRs were developed for detection of these 11 SAg genes. The first group comprises spea1-3+5, spec, speg, spej, spek, and spel. The second group consists of spea1-4, speh, spei, spem, ssa, and smez. The presence of Streptococcus pyogenes SAg genes can be immediately identified using a real-time method with SYBR-Green, thus providing an excellent tool in clinical diagnostics. After testing more than 300 clinical isolates, we identified one strain without any SAg gene. This finding contrasts with previous reports describing SAg genes located on every Streptococcus pyogenes genome. This SAg gene-negative strain also did not show any mitogenic activity. It is hypothesized that clinical isolates from patients may overrepresent bacterial strains with pathogenic factors, such as SAgs. PMID:17481952

Lintges, Maria; Arlt, Sabine; Uciechowski, Peter; Plümäkers, Birgit; Reinert, Ralf R; Al-Lahham, Adnan; Lütticken, Rudolf; Rink, Lothar

2007-10-01

62

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

SciTech Connect

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.

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

63

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

PubMed Central

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

Leers, W. D.

1975-01-01

64

ICESp1116, the Genetic Element Responsible for erm(B)-Mediated, Inducible Resistance to Erythromycin in Streptococcus pyogenes  

PubMed Central

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. PMID:23027190

Brenciani, Andrea; Tiberi, Erika; Morici, Eleonora; Orya??n, Erman; Varaldo, Pietro E.

2012-01-01

65

Bacteriophage content of M49 strains of Streptococcus pyogenes.  

PubMed

Bacteriophages are common autonomous migrating mobile genetic elements in group A Streptococcus (GAS) and are often associated with the carriage of various virulence genes, including toxins, mitogens and enzymes. Two collections of GAS type M49 strains isolated from invasive (22 strains) and noninvasive (16 strains) clinical cases have been studied for the presence of phage and phage-associated virulence genes. All the GAS strains carried from at least two to six phage genomes as determined by the number of known phage integrase genes found. A sampling of the invasive M49 strains showed that they belonged to the same multilocus sequence typing type, carried two specific integrase genes (int5 and int7), and contained the toxin genes speA, speH and speI. Other invasive strains lacking this gene profile carried the prophage integrating in mutL-mutS region and inducing the 'mutator' phenotype. We suggest that this specific phage-related virulence gene constellation might be an important factor increasing M49 GAS pathogenicity. PMID:19493003

Suvorov, Alexander N; Polyakova, Ekaterina M; McShan, W Michael; Ferretti, Joseph J

2009-05-01

66

Transcriptional Regulation of a Bacteriophage Encoded Extracellular DNase (Spd-3) by Rgg in Streptococcus pyogenes  

PubMed Central

The Streptococcus pyogenes transcriptional regulator Rgg controls the expression of virulence-associated genes encoded both within the core genome and within horizontally transmissible DNA such as temperate bacteriophage. Previously, we showed that Rgg binds to the non-coding DNA upstream of the bacteriophage gene encoding an extracellular DNase Spd-3. In the current study, we further characterized Rgg-mediated regulation of spd-3 expression. Two spd-3 transcripts were identified by northern blotting. The 5? ends were 27 and 594 nucleotides upstream of the start codon as determined with primer extension analysis and 5? RACE (rapid amplification of c-DNA ends), respectively. Results obtained with gel shift assays showed that purified Rgg bound specifically to non-coding DNA containing the promoters of both transcripts. Transcriptional fusion analyses confirmed the presence of Rgg-repressible promoters within these DNA regions. In addition, repression was associated with direct DNA binding by Rgg as determined with chromatin immunoprecipitation (ChIP) coupled with quantitative PCR (qPCR). The results show that the chromosomally encoded transcriptional regulator, Rgg, directly represses both bacteriophage promoters controlling the expression of Spd-3. The results provide new information regarding the regulation of prophage encoded virulence factors of S. pyogenes and highlight the complex evolutionary history of S. pyogenes and temperate bacteriophage. PMID:23613830

Anbalagan, Srivishnupriya; Chaussee, Michael S.

2013-01-01

67

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

Microsoft Academic Search

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

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

2001-01-01

68

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

PubMed

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. PMID:17011079

Bukvi? Krajaci?, Mirjana; Novak, Predrag; Cindri?, Mario; Brajsa, Karmen; Dumi?, Miljenko; Kujundzi?, Nedjeljko

2007-02-01

69

The structural characterization of a prophage-encoded extracellular DNase from Streptococcus pyogenes  

PubMed Central

The pathogenic bacterium Group A Streptococcus pyogenes produces several extracellular DNases that have been shown to facilitate invasive infection by evading the human host immune system. DNases degrade the chromatin in neutrophil extracellular traps, enabling the bacterium to evade neutrophil capture. Spd1 is a type I, nonspecific ???/metal-dependent nuclease from Streptococcus pyogenes, which is encoded by the SF370.1 prophage and is likely to be expressed as a result of prophage induction. We present here the X-ray structure of this DNase in the wild-type and Asn145Ala mutant form. Through structural and sequence alignments as well as mutagenesis studies, we have identified the key residues His121, Asn145 and Glu164, which are crucial for Spd1 nucleolytic activity and shown the active site constellation. Our wild-type structure alludes to the possibility of a catalytically blocked dimeric form of the protein. We have investigated the multimeric nature of Spd1 using size-exclusion chromatography with multi-angle light scattering (SEC-MALLS) in the presence and absence of the divalent metal ion Mg2+, which suggests that Spd1 exists in a monomeric form in solution. PMID:21948797

Korczynska, Justyna E.; Turkenburg, Johan P.; Taylor, Edward J.

2012-01-01

70

SclA, a novel collagen-like surface protein of Streptococcus pyogenes.  

PubMed

Surface proteins of Streptococcus pyogenes are important virulence factors. Here we describe a novel collagen-like surface protein, designated SclA (streptococcal collagen-like surface protein). The sclA gene was identified in silico using the Streptococcal Genome Sequencing Project with the recently identified protein GRAB as the probe. SclA has a signal sequence and a cell wall attachment region containing the prototypic LPXTGX motif. The surface-exposed part of SclA contains a unique NH(2)-terminal domain of 73 amino acids, followed by a collagen-like region. The sclA gene was found to be positively regulated by Mga, a transcriptional activator of several S. pyogenes virulence determinants. A mutant lacking cell wall-associated SclA was constructed and was found to be as effective as wild-type bacteria in platelet aggregation, survival in fresh human blood, and adherence to pharyngeal cells. The sclA gene was found in all 12 S. pyogenes strains that were investigated using PCR. Sequence analysis revealed that the signal sequence and the cell wall attachment region are highly conserved. The collagen-like domain is variable in its NH(2)-terminal region and has conserved repeated domains in its COOH-terminal part. SclA proteins from most strains have additional proline-rich repeats spacing the collagen-like domain and the cell wall attachment sequence. The unique NH(2)-terminal region is hypervariable, but computer predictions indicate a common secondary structure, with two alpha helices connected by a loop region. Immune selection may explain the hypervariability in the NH(2)-terminal region, whereas the preserved secondary structure implies that this region has a common function. These features and the Mga regulation are shared with the M protein of S. pyogenes. Moreover, as with the gene encoding the M protein, phylogenetic analysis indicates that horizontal gene transfer has contributed to the evolution of sclA. PMID:11035747

Rasmussen, M; Edén, A; Björck, L

2000-11-01

71

Carrier state of Haemophilus influenzae type b (Hib), Streptococcus pneumoniae, Streptococcus pyogenes, Neisseria meningitidis and Corynebacterium diphtheriae among school children in Pokhara, Nepal  

PubMed Central

Objective To determine the incidence of carrier state of Haemophilus influenzae type b, Streptococcus pneumoniae (S. pneumoniae), Streptococcus pyogenes, Neisseria meningitidis and Corynebacterium diphtheriae among school children. Methods Specimen from posterior pharyngeal wall and tonsils were collected on calcium alginate coated swabs from 102 participants. Processing of specimen and antimicrobial susceptibility testing was done by standard procedures. Results Potential pathogens isolated in our study were S. pneumoniae (14.7%), Staphylococcus aureus (12.7%), Corynebacterium diphtheriae (3.9%), Streptococcus pyogenes (3.9%) and Haemophilus influenzae (1.9%). Important findings in antibiogram include high resistance of S. pneumoniae to penicillin (73%) and resistance of Staphylococcus aureus to oxacillin (23%). Conclusions Pharyngeal colonization by S. pneumoniae among school children was found high and there is need of introduction of pneumococcal vaccines among children. Despite expected universal vaccination, pharyngeal colonization by Corynebacterium diphtheriae is possible and there is possibility of transmission.

Bhatta, Dharm Raj; Gokhale, Shishir; Sharma, Annavarapu Laxminarasimha; Gupta, Umesh; Gaur, Abhishek; Gowda, Supram; Raut, Shristi; Thapa, Sangeeta; Khadka, Rupendra

2014-01-01

72

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

PubMed Central

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

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

2014-01-01

73

Structural conservation, variability, and immunogenicity of the T6 backbone pilin of serotype M6 Streptococcus pyogenes.  

PubMed

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

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

2014-07-01

74

Manuka honey inhibits the development of Streptococcus pyogenes biofilms and causes reduced expression of two fibronectin binding proteins.  

PubMed

Streptococcus pyogenes (group A Streptococcus; GAS) is always of clinical significance in wounds where it can initiate infection, destroy skin grafts and persist as a biofilm. Manuka honey has broad spectrum antimicrobial activity and its use in the clinical setting is beginning to gain acceptance with the continuing emergence of antibiotic resistance and the inadequacy of established systemic therapies; novel inhibitors may affect clinical practice. In this study, the effect of manuka honey on S. pyogenes (M28) was investigated in vitro with planktonic and biofilm cultures using MIC, MBC, microscopy and aggregation efficiency. Bactericidal effects were found in both planktonic cultures and biofilms, although higher concentrations of manuka honey were needed to inhibit biofilms. Abrogation of adherence and intercellular aggregation was observed. Manuka honey permeated 24 h established biofilms of S. pyogenes, resulting in significant cell death and dissociation of cells from the biofilm. Sublethal concentrations of manuka honey effectively prevented the binding of S. pyogenes to the human tissue protein fibronectin, but did not inhibit binding to fibrinogen. The observed inhibition of fibronectin binding was confirmed by a reduction in the expression of genes encoding two major fibronectin-binding streptococcal surface proteins, Sof and SfbI. These findings indicate that manuka honey has potential in the topical treatment of wounds containing S. pyogenes. PMID:22294681

Maddocks, Sarah E; Lopez, Marta Salinas; Rowlands, Richard S; Cooper, Rose A

2012-03-01

75

Streptococcus pyogenes Malate Degradation Pathway Links pH Regulation and Virulence.  

PubMed

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

Paluscio, Elyse; Caparon, Michael G

2015-03-01

76

Purification, crystallization and preliminary crystallographic analysis of the adhesion domain of Epf from Streptococcus pyogenes  

PubMed Central

The extracellular protein Epf from Streptococcus pyogenes is important for streptococcal adhesion to human epithelial cells. However, Epf has no sequence identity to any protein of known structure or function. Thus, several predicted domains of the 205?kDa protein Epf were cloned separately and expressed in Escherichia coli. The N-terminal domain of Epf was crystallized in space groups P21 and P212121 in the presence of the protease chymotrypsin. Mass spectrometry showed that the species crystallized corresponded to a fragment comprising residues 52–357 of Epf. Complete data sets were collected to 2.0 and 1.6?Å resolution, respectively, at the Australian Synchrotron. PMID:22750867

Linke, Christian; Siemens, Nikolai; Middleditch, Martin J.; Kreikemeyer, Bernd; Baker, Edward N.

2012-01-01

77

Role of Serine/Threonine Phosphatase (SP-STP) in Streptococcus pyogenes Physiology and Virulence*  

PubMed Central

Reversible phosphorylation is the key mechanism regulating several cellular events in prokaryotes and eukaryotes. In prokaryotes, signal transduction is perceived to occur primarily via the two-component signaling system involving histidine kinases and cognate response regulators. Although an alternative regulatory pathway controlled by the eukaryote-type serine/threonine kinase (Streptococcus pyogenes serine/threonine kinase; SP-STK) has been shown to modulate bacterial growth, division, adherence, invasion, and virulence in group A Streptococcus (GAS; S. pyogenes), the precise role of the co-transcribing serine/threonine phosphatase (SP-STP) has remained enigmatic. In this context, this is the first report describing the construction and characterization of non-polar SP-STP mutants in two different strains of Type M1 GAS. The STP knock-out mutants displayed increased bacterial chain lengths in conjunction with thickened cell walls, significantly reduced capsule and hemolysin production, and restoration of the phenotypes postcomplementation. The present study also reveals important contribution of cognately regulated-reversible phosphorylation by SP-STK/SP-STP on two major response regulators of two-component systems, WalRK and CovRS. We also demonstrate a distinct role of SP-STP in terms of expression of surface proteins and SpeB in a strain-specific manner. Further, the attenuation of virulence in the absence of STP and its restoration only in the complemented strains that were generated by the use of a low copy plasmid and not by a high copy one emphasize not only the essential role of STP in virulence but also highlight the tightly regulated SP-STP/SP-STK-mediated cognate functions. SP-STP thus is an important regulator of GAS virulence and plays a critical role in GAS pathogenesis. PMID:21917918

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

2011-01-01

78

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

PubMed Central

Puerperal sepsis is a leading cause of maternal mortality worldwide. Streptococcus pyogenes (Group A Streptococcus; GAS) is a major etiologic agent of severe postpartum sepsis yet little is known regarding the pathogenesis of these infections. Tissue macrophages provide innate defense against GAS and their actions are highly regulated. The intracellular second messenger cAMP can negatively regulate macrophage actions against GAS. Because leukotriene (LT) B4 has been shown to suppress intracellular cAMP in macrophages, we hypothesized that it could enhance innate defenses against GAS. We assessed the capacity of LTB4 to modulate anti-streptococcal actions of human macrophages, including placental and decidual macrophages and used a novel intrauterine infection model of GAS in mice lacking the 5-lipoxygenase (5LO) enzyme to determine the role of endogenous LTs in host defense against this pathogen. Animals lacking 5LO were significantly more vulnerable to intrauterine GAS infection than wild-type mice and showed enhanced dissemination of bacteria out of the uterus and a more robust inflammatory response compared to wild-type mice. Additionally, LTB4 reduced intracellular cAMP levels via the BLT1 receptor and was a potent stimulant of macrophage phagocytosis and NADPH oxidase-dependent intracellular killing of GAS. Importantly, interference was observed between the macrophage immunomodulatory actions of LTB4 and the cAMP-inducing lipid prostaglandin E2, suggesting that interplay between pro- and anti-inflammatory compounds may be important in vivo. This work underscores the potential for pharmacological targeting of lipid mediator signaling cascades in the treatment of invasive GAS infections. PMID:23325886

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

2012-01-01

79

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

SciTech Connect

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.

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

1988-04-01

80

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

PubMed Central

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

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

2015-01-01

81

Kinetic and Structural Characterization for Cofactor Preference of Succinic Semialdehyde Dehydrogenase from Streptococcus pyogenes  

PubMed Central

The ?-Aminobutyric acid (GABA) that is found in prokaryotic and eukaryotic organisms has been used in various ways as a signaling molecule or a significant component generating metabolic energy under conditions of nutrient limitation or stress, through GABA catabolism. Succinic semialdehyde dehydrogenase (SSADH) catalyzes the oxidation of succinic semialdehyde to succinic acid in the final step of GABA catabolism. Here, we report the catalytic properties and two crystal structures of SSADH from Streptococcus pyogenes (SpSSADH) regarding its cofactor preference. Kinetic analysis showed that SpSSADH prefers NADP+ over NAD+ as a hydride acceptor. Moreover, the structures of SpSSADH were determined in an apo-form and in a binary complex with NADP+ at 1.6 Å and 2.1 Å resolutions, respectively. Both structures of SpSSADH showed dimeric conformation, containing a single cysteine residue in the catalytic loop of each subunit. Further structural analysis and sequence comparison of SpSSADH with other SSADHs revealed that Ser158 and Tyr188 in SpSSADH participate in the stabilization of the 2’-phosphate group of adenine-side ribose in NADP+. Our results provide structural insights into the cofactor preference of SpSSADH as the gram-positive bacterial SSADH. PMID:25256219

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

2014-01-01

82

Structural Model for Covalent Adhesion of the Streptococcus pyogenes Pilus through a Thioester Bond*  

PubMed Central

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. PMID:24220033

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

2014-01-01

83

Heparin-inhibitable basement membrane-binding protein of Streptococcus pyogenes.  

PubMed Central

Solubilized surface proteins of Streptococcus pyogenes serotype M6 were found by indirect immunofluorescence assays to bind selectively to proteoglycan-containing regions of basement membranes of kidney and cardiac muscle in vitro. Epithelial, endothelial, and interstitial cells were unstained. Binding of streptococcal protein to basement membranes was competitively inhibited by heparin and, to a lesser extent, by heparan sulfate. Weak inhibition was also observed with other glycosaminoglycans, including dermatan sulfate, chondroitin sulfate, and hyaluronic acid. Type IV collagen, gelatin, serum fibronectin, glucuronic acid, and a selection of monosaccharides had no significant effects on binding. The heparin-inhibitable basement membrane-binding protein was purified by affinity chromatography on heparin-Sepharose 6-B. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and urea dissociated the affinity-purified protein into two polypeptides of 9,000 and 15,000 mrs. Chemical analyses revealed that the purified protein was devoid of cysteine, amino and neutral sugars, and phosphate. Thus, the polypeptides are not glycosylated or complexed with trace amounts of lipoteichoic acid or polysaccharide. Binding of purified protein to tissue was determined by direct radioassay and indirect immunofluorescence and was inhibitable by heparin. Although the in vivo effects of this streptococcal component remain to be determined, its deposition on basement membranes in vitro supports the hypothesis that it contributes to the pathogenesis of poststreptococcal glomerulonephritis or acute rheumatic fever. Images PMID:3290104

Bergey, E J; Stinson, M W

1988-01-01

84

Constitutive and inflammation-dependent antimicrobial peptides produced by epithelium are differentially processed and inactivated by the commensal Finegoldia magna and the pathogen Streptococcus pyogenes.  

PubMed

Epithelial linings serve as physical barriers and produce antimicrobial peptides (AMPs) to maintain host integrity. Examples are the bactericidal proteins midkine (MK) and BRAK/CXCL14 that are constitutively produced in the skin epidermal layer, where the anaerobic Gram-positive coccoid commensal Finegoldia magna resides. Consequently, this bacterium is likely to encounter both MK and BRAK/CXCL14, making these molecules possible threats to its habitat. In this study, we show that MK expression is upregulated during inflammation, concomitant with a strong downregulation of BRAK/CXCL14, resulting in changed antibacterial conditions. MK, BRAK/CXCL14, and the inflammation-dependent antimicrobial ?-defensins human ?-defensin (hBD)-2 and hBD-3 all showed bactericidal activity against both F. magna and the virulent pathogen Streptococcus pyogenes at similar concentrations. SufA, a released protease of F. magna, degraded MK and BRAK/CXCL14 but not hBD-2 nor hBD-3. Cleavage was seen at lysine and arginine residues, amino acids characteristic of AMPs. Intermediate SufA-degraded fragments of MK and BRAK/CXCL14 showed stronger bactericidal activity against S. pyogenes than F. magna, thus promoting survival of the latter. In contrast, the cysteine-protease SpeB of S. pyogenes rapidly degraded all AMPs investigated. The proteins FAF and SIC, released by F. magna and S. pyogenes, respectively, neutralized the antibacterial activity of MK and BRAK/CXCL14, protein FAF being the most efficient. Quantitation and colocalization by immunoelectron microscopy demonstrated significant levels and interactions of the molecules in in vivo and ex vivo samples. The findings reflect strategies used by a permanently residing commensal and a virulent pathogen, the latter operating during the limited time course of invasive disease. PMID:21918193

Frick, Inga-Maria; Nordin, Sara L; Baumgarten, Maria; Mörgelin, Matthias; Sørensen, Ole E; Olin, Anders I; Egesten, Arne

2011-10-15

85

Outbreak of Streptococcus pyogenes emm type 58 in a high dependency unit of a level-1 trauma center of India  

PubMed Central

Background and Aims: Group A Streptococcus (GAS) can cause illnesses ranging from self-limited to severe, life-threatening, invasive infections. The objective of the following study was to investigate a suspected Streptococcus pyogenes outbreak in a high dependency unit (HDU) of our trauma center. Materials and Methods: All the isolates of beta hemolytic Streptococci were identified by standard microbiological methods, Vitek 2 system and latex agglutination tests. Antimicrobial susceptibility testing was performed as recommended by Clinical Laboratory Standards Institute. Exotoxin genes, including speA, speB, speC, speF, smeZ, ssa, speG, speH, speJ, speL, speM and speI were detected by polymerase chain reaction (PCR). The emm types of isolates of S. pyogenes were determined by sequencing the variable 5’ end of emm gene after amplification by PCR. Results: In a 28 bedded poly-trauma ward with a four bedded HDU three out of four patients developed S. pyogenes emm type 58 infection. The strain was macrolide and tetracycline resistant and produced the Streptococcal pyrogenic exotoxins speB, speC, speG, speF and smeZ. Surveillance sampling was done for investigation from patients, health-care workers and environmental samples. Conclusion: An outbreak of GAS infections was established caused by the uncommonly reported emm type 58. The outbreak was controlled by prompt treatment, intensive surveillance, feedback and training. PMID:24678149

Mathur, Purva; Bhardwaj, Nidhi; Gupta, Gunjan; Punia, Parul; Tak, Vibhor; John, Nibu Varghese; Agrawal, Deepak; Misra, Manesh C.

2014-01-01

86

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

PubMed Central

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

Houston, C W; Ferretti, J J

1981-01-01

87

Macrolide Resistance in Peptostreptococcus spp. Mediated by ermTR: Possible Source of Macrolide-Lincosamide-Streptogramin B Resistance in Streptococcus pyogenes  

Microsoft Academic Search

Eighty percent (21 of 26) of macrolide-resistant Peptostreptococcus strains studied harbored the ermTR gene. This methyltransferase gene is also the most frequently found gene among macrolide-lincosamide-strepto- gramin B-resistant Streptococcus pyogenes strains. Transfer of the ermTR gene from Peptostreptococcus magnus to macrolide-susceptible S. pyogenes strains indicates that this resistance determinant may circulate among gram-positive aerobic and anaerobic species of the oropharyngeal

MILAGRO REIG; JUAN-CARLOS GALAN; FERNANDO BAQUERO; JOSE CLAUDIO PEREZ-DIAZ

2001-01-01

88

Streptococcus pyogenes and Lactobacillus rhamnosus differentially induce maturation and production of Th1-type cytokines and chemokines in human monocyte-derived dendritic cells  

Microsoft Academic Search

Dendritic cells (DCs) are the most ef- ficient antigen-presenting cells and thus, have a major role in regulating host immune responses. In the present study, we have analyzed the ability of Gram-positive, pathogenic Streptococcus pyogenes and nonpathogenic Lactobacillus rhamnosus to in- duce the maturation of human monocyte-derived DCs. Stimulation of DCs with S. pyogenes resulted in strong expression of DC

Ville Veckman; Minja Miettinen; Jaana Pirhonen; Jukka Siren; Sampsa Matikainen; Ilkka Julkunen

2003-01-01

89

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

SciTech Connect

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.

Tran, Timothy H.; Christoffersen, S.; Allan, Paula W.; Parker, William B.; Piskur, Jure; Serra, I.; Terreni, M.; Ealick, Steven E. (Cornell); (Pavia); (Lund); (Southern Research)

2011-09-20

90

Streptococcus pyogenes Polymyxin B-Resistant Mutants Display Enhanced ExPortal Integrity  

PubMed Central

The ExPortal protein secretion organelle in Streptococcus pyogenes is an anionic phospholipid-containing membrane microdomain enriched in Sec translocons and postsecretion protein biogenesis factors. Polymyxin B binds to and disrupts ExPortal integrity, resulting in defective secretion of several toxins. To gain insight into factors that influence ExPortal organization, a genetic screen was conducted to select for spontaneous polymyxin B-resistant mutants displaying enhanced ExPortal integrity. Whole-genome resequencing of 25 resistant mutants revealed from one to four mutations per mutant genome clustered primarily within a core set of 10 gene groups. Construction of mutants with individual deletions or insertions demonstrated that 7 core genes confer resistance and enhanced ExPortal integrity through loss of function, while 3 were likely due to gain of function and/or combinatorial effects. Core resistance genes include a transcriptional regulator of lipid biosynthesis, several genes involved in nutrient acquisition, and a variety of genes involved in stress responses. Two members of the latter class also function as novel regulators of the secreted SpeB cysteine protease. Analysis of the most frequently isolated mutation, a single nucleotide deletion in a track of 9 consecutive adenine residues in pstS, encoding a component of a high-affinity Pi transporter, suggests that this sequence functions as a molecular switch to facilitate stress adaptation. Together, these data suggest the existence of a membrane stress response that promotes enhanced ExPortal integrity and resistance to cationic antimicrobial peptides. PMID:24794568

Port, Gary C.; Vega, Luis A.; Nylander, Andrew B.

2014-01-01

91

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

PubMed Central

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

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

2014-01-01

92

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

PubMed Central

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

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

2014-01-01

93

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

PubMed

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. PMID:25001603

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

2014-09-01

94

Functional differences between Streptococcus pyogenes cluster 1 and cluster 2b streptokinases are determined by their ?-domains.  

PubMed

Cluster 1 streptokinases (SK1) from Streptococcus pyogenes (GAS) show substantially higher human plasminogen (hPg) activation activities and tighter hPg binding affinities than cluster 2b streptokinases (SK2b) in solution. The extent to which the different domains of SK are responsible for these differences is unknown. We exchanged each of the three known SK domains (?, ?, and ?) between SK1 and SK2b and assessed the function of the resulting variants. Our results show that primary structural differences in the ?-domains dictate these functional differences. This first report on the primary structure-functional relationship between naturally occurring SK1 and SK2b sheds new light on the mechanism of hPg activation by SK, a critical virulence determinant in this species of human pathogenic bacteria. PMID:23474243

Zhang, Yueling; Liang, Zhong; Glinton, Kristofor; Ploplis, Victoria A; Castellino, Francis J

2013-05-01

95

Sequence analysis and expression in Escherichia coli of the hyaluronidase gene of Streptococcus pyogenes bacteriophage H4489A.  

PubMed Central

The hyaluronidase gene (hylP) from Streptococcus pyogenes bacteriophage H4489A was previously cloned into Escherichia coli plasmid pUC8 as a 3.1-kilobase ThaI fragment. Southern hybridization experiments confirmed the origin of this fragment in bacteriophage H4489A before determination of the nucleotide sequence of the entire fragment. Two open reading frames (ORFs) were found, the first of which specified a 39,515-molecular-weight protein identified as the bacteriophage hyaluronidase. The second ORF encoded a 65,159-molecular-weight protein of unknown function. Putative transcription and translation control sequences for each ORF were identified by using a plasmid containing a promoterless chloramphenicol acetyltransferase gene. Controlled exclusive expression of the hylP gene via the T7 polymerase-promoter system in E. coli resulted in a 40,000-dalton protein, a result consistent with the coding capacity of the hylP gene. Images PMID:2643574

Hynes, W L; Ferretti, J J

1989-01-01

96

Illustration of a Common Framework for Relating Multiple Typing Methods by Application to Macrolide-Resistant Streptococcus pyogenes  

PubMed Central

The studies that correlate the results obtained by different typing methodologies rely solely on qualitative comparisons of the groups defined by each methodology. We propose a framework of measures for the quantitative assessment of correspondences between different typing methods as a first step to the global mapping of type equivalences. A collection of 325 macrolide-resistant Streptococcus pyogenes isolates associated with pharyngitis cases in Portugal was used to benchmark the proposed measures. All isolates were characterized by macrolide resistance phenotyping, T serotyping, emm sequence typing, and pulsed-field gel electrophoresis (PFGE), using SmaI or Cfr9I and SfiI. A subset of 41 isolates, representing each PFGE cluster, was also characterized by multilocus sequence typing (MLST). The application of Adjusted Rand and Wallace indices allowed the evaluation of the strength and the directionality of the correspondences between the various typing methods and showed that if PFGE or MLST data are available one can confidently predict the emm type (Wallace coefficients of 0.952 for both methods). In contrast, emm typing was a poor predictor of PFGE cluster or MLST sequence type (Wallace coefficients of 0.803 and 0.655, respectively). This was confirmed by the analysis of the larger data set available from http://spyogenes.mlst.net and underscores the necessity of performing PFGE or MLST to unambiguously define clones in S. pyogenes. PMID:16825375

Carriço, J. A.; Silva-Costa, C.; Melo-Cristino, J.; Pinto, F. R.; de Lencastre, H.; Almeida, J. S.; Ramirez, M.

2006-01-01

97

Effects of the ERES Pathogenicity Region Regulator Ralp3 on Streptococcus pyogenes Serotype M49 Virulence Factor Expression  

PubMed Central

Streptococcus pyogenes (group A streptococcus [GAS]) is a highly virulent Gram-positive bacterium. For successful infection, GAS expresses many virulence factors, which are clustered together with transcriptional regulators in distinct genomic regions. Ralp3 is a central regulator of the ERES region. In this study, we investigated the role of Ralp3 in GAS M49 pathogenesis. The inactivation of Ralp3 resulted in reduced attachment to and internalization into human keratinocytes. The ?ralp3 mutant failed to survive in human blood and serum, and the hyaluronic acid capsule was slightly decreased. In addition, the mutant showed a lower binding capacity to human plasminogen, and the SpeB activity was significantly decreased. Complementation of the ?ralp3 mutant restored the wild-type phenotype. The transcriptome and quantitative reverse transcription-PCR analysis of the serotype M49 GAS strain and its isogenic ?ralp3 mutant identified 16 genes as upregulated, and 43 genes were found to be downregulated. Among the downregulated genes, there were open reading frames encoding proteins involved in metabolism (e.g., both lac operons and the fru operon), genes encoding lantibiotics (e.g., the putative salivaricin operon), and ORFs encoding virulence factors (such as the whole Mga core regulon and further genes under Mga control). In summary, the ERES region regulator Ralp3 is an important serotype-specific transcriptional regulator for virulence and metabolic control. PMID:22544273

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

2012-01-01

98

Substitution of Cysteine 192 in a Highly Conserved Streptococcus pyogenesExtracellular Cysteine Protease (Interleukin 1bConvertase) Alters Proteolytic Activity and Ablates Zymogen Processing  

Microsoft Academic Search

Virtually all strains of the human pathogenic bacterium Streptococcus pyogenes express a highly conserved extracellular cysteine protease. The protein is made as an inactive zymogen of 40,000 Da and undergoes autocatalytic truncation to result in a 28,000-Da active protease. Numerous independent lines of investigation suggest that this enzyme participates in one or more phases of host-parasite interaction, such as inflammation

JAMES M. MUSSER; KATHRYN STOCKBAUER; VIVEK KAPUR; ANDGARY W. RUDGERS

99

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

PubMed

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. PMID:25614568

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

2015-01-01

100

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

PubMed

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. PMID:24958729

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

2014-08-01

101

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

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

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

2014-01-01

102

Proteome-wide selected reaction monitoring assays for the human pathogen Streptococcus pyogenes  

PubMed Central

Selected reaction monitoring mass spectrometry (SRM-MS) is a targeted proteomics technology used to identify and quantify proteins with high sensitivity, specificity and high reproducibility. Execution of SRM-MS relies on protein-specific SRM assays, a set of experimental parameters that requires considerable effort to develop. Here we present a proteome-wide SRM assay repository for the gram-positive human pathogen group A Streptococcus. Using a multi-layered approach we generated SRM assays for 10,412 distinct group A Streptococcus peptides followed by extensive testing of the selected reaction monitoring assays in >200 different group A Streptococcus protein pools. Based on the number of SRM assay observations we created a rule-based selected reaction monitoring assay-scoring model to select the most suitable assays per protein for a given cellular compartment and bacterial state. The resource described here represents an important tool for deciphering the group A Streptococcus proteome using selected reaction monitoring and we anticipate that concepts described here can be extended to other pathogens. PMID:23250431

Karlsson, Christofer; Malmström, Lars; Aebersold, Ruedi; Malmström, Johan

2012-01-01

103

Identification and Characterization of a Novel Heme-Associated Cell Surface Protein Made by Streptococcus pyogenes  

Microsoft Academic Search

Analysis of the genome sequence of a serotype M1 group A Streptococcus (GAS) strain identified a gene encoding a previously undescribed putative cell surface protein. The gene was cloned from a serotype M1 strain, and the recombinant protein was overexpressed in Escherichia coli and purified to homogeneity. The purified protein was associated with heme in a 1:1 stoichiometry. This streptococcal

Benfang Lei; Laura M. Smoot; Heather M. Menning; Jovanka M. Voyich; Subbarao V. Kala; Frank R. Deleo; Sean D. Reid; James M. Musser

2002-01-01

104

Initial events in the pathogenesis of acute tonsillitis caused by Streptococcus pyogenes 1 This paper was presented in part at the XVI World Congress of Otorhinolaryngology, Head and Neck Surgery, Sydney, Australia, March 2–7, 1997. 1  

Microsoft Academic Search

Bacterial and epithelial cell samples were obtained, within 24 h of onset of pharyngeal symptoms, from the palatine tonsils of nine patients (four female and five male; age range 10–40 years, median age 23) with acute tonsillitis, culture-positive for Streptococcus pyogenes. The specimens were examined using fluorescein isothiocyanate- (FITC) and gold-labelled antiserum to S. pyogenes and fluorescence, scanning electron and

Markus Lilja; Simo Räisänen; Lars-Eric Stenfors

1998-01-01

105

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

PubMed Central

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

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

1985-01-01

106

In vitro pharmacokinetic/pharmacodynamic activity of NXL103 versus clindamycin and linezolid against clinical Staphylococcus aureus and Streptococcus pyogenes isolates.  

PubMed

NXL103 (linopristin/flopristin, 30/70) is a novel oral streptogramin combination with activity against a large variety of multidrug-resistant Gram-positive pathogens. The objective of this study was to evaluate the in vitro activity of NXL103 in comparison with oral comparators (clindamycin and linezolid). Six clinical isolates [four meticillin-resistant Staphylococcus aureus (MRSA) and two Streptococcus pyogenes] were exposed for 48 h in an in vitro pharmacokinetic/pharmacodynamic (PK/PD) model at a starting inoculum of ca. 10(6) colony-forming units (CFU)/mL. Antimicrobial simulations included NXL103 500 mg every 12 h, linezolid 600 mg every 12 h and clindamycin 450 mg every 6 h. Bactericidal and static effects were defined as ?3log(10) and <3log(10) CFU/mL kill from the starting inoculum, respectively. Experiments were performed in duplicate to ensure reproducibility, and differences between regimens were evaluated by analysis of variance (ANOVA) with Tukey's post-hoc test. NXL103 exhibited lower minimum inhibitory concentrations than comparators, with values ?0.06 mg/L for S. pyogenes and 0.125-0.25 mg/L for MRSA isolates. In the PK/PD model, NXL103 demonstrated significantly better activity than linezolid and clindamycin (P<0.05), achieving sustained bactericidal activity within <2 h against S. pyogenes strains and between 7.3-32 h against MRSA isolates. In contrast, linezolid only exhibited a static effect, whereas clindamycin achieved 3log(10) kill at 6h against the unique clindamycin-susceptible S. pyogenes strain evaluated. In conclusion, at therapeutic concentrations NXL103 exhibits promising activity against both MRSA and S. pyogenes strains, including clindamycin-resistant organisms. Further in vitro and in vivo experiments are warranted to explore the therapeutic benefit of NXL103 for the treatment of Gram-positive skin and soft-tissue infections. PMID:21764263

Vidaillac, Celine; Parra-Ruiz, Jorge; Winterfield, Patricia; Rybak, Michael J

2011-10-01

107

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

PubMed Central

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

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

1996-01-01

108

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

PubMed Central

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

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

2012-01-01

109

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

PubMed Central

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

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

1995-01-01

110

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

PubMed Central

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

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

2011-01-01

111

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

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. PMID:25403787

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

2015-01-01

112

Characterization of emm types and superantigens of Streptococcus pyogenes isolates from children during two sampling periods.  

PubMed

The characteristics of 359 group A streptococcal (GAS) isolates collected from Chinese paediatric patients in two periods (1993-1994, 2005-2006) were studied. Isolates were assigned to emm types and assayed for eight superantigen (SAg) genes (speA, speC, speH, speI, speG, speJ, ssa, SMEZ). Types emm1 and emm12 were consistently the most prevalent during the two periods, while others varied in frequency. GAS isolates carrying six or more SAg genes increased from 46.53% (1993-1994) to 78.39% (2005-2006); ssa, speH and speJ genes (P<0.05) increased but speA declined (P<0.05). SAg gene profiles were closely associated with the emm type, but strains of the same emm type sometimes carried different SAg genes in the two periods. No significant difference in emm-type distribution and SAg gene profile was noted between isolates from different diseases. These data may contribute towards the development of a GAS vaccine in China. PMID:19243651

Ma, Y; Yang, Y; Huang, M; Wang, Y; Chen, Y; Deng, L; Yu, S; Deng, Q; Zhang, H; Wang, C; Liu, L; Shen, X

2009-10-01

113

?1-pyrroline-5-carboxylate reductase as a new target for therapeutics: inhibition of the enzyme from Streptococcus pyogenes and effects in vivo.  

PubMed

Compounds able to interfere with amino acid biosynthesis have the potential to inhibit cell growth. In both prokaryotic and eukaryotic microorganisms, unless an ornithine cyclodeaminase is present, the activity of ?1-pyrroline-5-carboxylate (P5C) reductase is mandatory to proline production, and the enzyme inhibition should result in amino acid starvation, blocking in turn protein synthesis. The ability of some substituted derivatives of aminomethylenebisphosphonic acid and its analogues to interfere with the activity of the enzyme from the human pathogen Streptococcus pyogenes was investigated. Several compounds were able to suppress activity in the micromolar range of concentrations, with a mechanism of uncompetitive type with respect to the substrate P5C and non-competitive with respect to the electron donor NAD(P)H. The actual occurrence of enzyme inhibition in vivo was supported by the effects of the most active derivatives upon bacterial growth and free amino acid content. PMID:21744012

Forlani, Giuseppe; Petrollino, Davide; Fusetti, Massimo; Romanini, Letizia; Nocek, Bogus?aw; Joachimiak, Andrzej; Berlicki, Lukasz; Kafarski, Pawe?

2012-06-01

114

Activation of the Nlrp3 Inflammasome by Streptococcus pyogenes Requires Streptolysin O and NF-?B Activation but Proceeds Independently of TLR Signaling and P2X7 Receptor1  

PubMed Central

Macrophages play a crucial role in the innate immune response against the human pathogen Streptococcus pyogenes, yet the innate immune response against the bacterium is poorly characterized. In the present study, we show that caspase-1 activation and IL-1? secretion were induced by live, but not killed S. pyogenes, and required expression of the pore-forming toxin streptolysin O. Using macrophages deficient in inflammasome components, we found that both Nlrp3 and Asc were crucial for caspase-1 activation and IL-1? secretion, but dispensable for pro-IL-1? induction, in response to S. pyogenes infection. Conversely, macrophages deficient in the essential TLR adaptors Myd88 and Trif showed normal activation of caspase-1, but impaired induction of pro-IL-1? and secretion of IL-1?. Notably, activation of caspase-1 by TLR2 and TLR4 ligands in the presence of SLO required Myd88/Trif whereas that induced by S. pyogenes was blocked by inhibition of NF-?B. Unlike activation of the Nlrp3 inflammasome by TLR ligands, the induction of caspase-1 activation by S. pyogenes did not require exogenous ATP or the P2X7R. In vivo experiments revealed that Nlrp3 was critical for the production of IL-1? but was not important for survival in a mouse model of S. pyogenes peritoneal infection. These results indicate that caspase-1 activation in response to S. pyogenes infection requires NF-?B and the virulence factor streptolysin O, but proceeds independently of P2X7R and TLR signaling. PMID:19812205

Harder, Jurgen; Franchi, Luigi; Muñoz-Planillo, Raúl; Park, Jong-Hwan; Reimer, Thornik; Núñez, Gabriel

2009-01-01

115

M.SpyI, a DNA Methyltransferase Encoded on a mefA Chimeric Element, Modifies the Genome of Streptococcus pyogenes?  

PubMed Central

While screening the clonality of Streptococcus pyogenes isolates from an outbreak of erythromycin-resistant pharyngitis in Pittsburgh, PA, we found a correlation between the presence of the chimeric element ?10394.4 (carrying the macrolide efflux gene, mefA) and genomic DNA being resistant to cleavage by SmaI restriction endonuclease. A search of the open reading frames in ?10394.4 identified a putative type II restriction-modification (R-M) cassette containing a cytosine methyltransferase gene (spyIM). Heterologous expression of the cloned spyIM gene, as well as allelic-replacement experiments, showed that the action of this methyltransferase (M.SpyI) was responsible for the inhibition of SmaI digestion of genomic DNA in the ?10394.4-containing isolates. Analysis of the methylation patterns of streptococcal genomic DNA from spyIM-positive strains, a spyIM deletion mutant, and a spyIM-negative strain determined that M.SpyI specifically recognized and methylated the DNA sequence to generate 5?-CmCNGG. To our knowledge, this is the first methyltransferase gene from S. pyogenes to be cloned and to have its activity characterized. These results reveal why pulsed field gel electrophoresis analysis of SmaI-digested genomic DNA cannot be used to analyze the clonality of some streptococci containing ?10394.4 and may explain the inability of previous epidemiological studies to use SmaI to analyze DNAs from macrolide-resistant streptococci. The presence of the SpyI R-M cassette in ?10394.4 could impart a selective advantage to host strain survival and may provide another explanation for the observed increase in macrolide-resistant streptococci. PMID:17085578

Euler, Chad W.; Ryan, Patricia A.; Martin, Judith M.; Fischetti, Vincent A.

2007-01-01

116

The Membrane Bound LRR Lipoprotein Slr, and the Cell Wall-Anchored M1 Protein from Streptococcus pyogenes Both Interact with Type I Collagen  

PubMed Central

Streptococcus pyogenes is an important human pathogen and surface structures allow it to adhere to, colonize and invade the human host. Proteins containing leucine rich repeats (LRR) have been indentified in mammals, viruses, archaea and several bacterial species. The LRRs are often involved in protein-protein interaction, are typically 20–30 amino acids long and the defining feature of the LRR motif is an 11-residue sequence LxxLxLxxNxL (x being any amino acid). The streptococcal leucine rich (Slr) protein is a hypothetical lipoprotein that has been shown to be involved in virulence, but at present no ligands for Slr have been identified. We could establish that Slr is a membrane attached horseshoe shaped lipoprotein by homology modeling, signal peptidase II inhibition, electron microscopy (of bacteria and purified protein) and immunoblotting. Based on our previous knowledge of LRR proteins we hypothesized that Slr could mediate binding to collagen. We could show by surface plasmon resonance that recombinant Slr and purified M1 protein bind with high affinity to collagen I. Isogenic slr mutant strain (MB1) and emm1 mutant strain (MC25) had reduced binding to collagen type I as shown by slot blot and surface plasmon resonance. Electron microscopy using gold labeled Slr showed multiple binding sites to collagen I, both to the monomeric and the fibrillar structure, and most binding occurred in the overlap region of the collagen I fibril. In conclusion, we show that Slr is an abundant membrane bound lipoprotein that is co-expressed on the surface with M1, and that both these proteins are involved in recruiting collagen type I to the bacterial surface. This underlines the importance of S. pyogenes interaction with extracellular matrix molecules, especially since both Slr and M1 have been shown to be virulence factors. PMID:21655249

Bober, Marta; Mörgelin, Matthias; Olin, Anders I.; von Pawel-Rammingen, Ulrich; Collin, Mattias

2011-01-01

117

Streptococcus pyogenes Ser/Thr Kinase-regulated Cell Wall Hydrolase Is a Cell Division Plane-recognizing and Chain-forming Virulence Factor*  

PubMed Central

Cell division and cell wall synthesis are closely linked complex phenomena and play a crucial role in the maintenance and regulation of bacterial virulence. Eukaryotic-type Ser/Thr kinases reported in prokaryotes, including that in group A Streptococcus (GAS) (Streptococcus pyogenes Ser/Thr kinase (SP-STK)), regulate cell division, growth, and virulence. The mechanism of this regulation is, however, unknown. In this study, we demonstrated that SP-STK-controlled cell division is mediated under the positive regulation of secretory protein that possesses a cysteine and histidine-dependent aminohydrolases/peptidases (CHAP) domain with functionally active cell wall hydrolase activity (henceforth named as CdhA (CHAP-domain-containing and chain-forming cell wall hydrolase). Deletion of the CdhA-encoding gene resulted in severe cell division and growth defects in GAS mutants. The mutant expressing the truncated CdhA (devoid of the CHAP domain), although displayed no such defects, it became attenuated for virulence in mice and highly susceptible to cell wall-acting antibiotics, as observed for the mutant lacking CdhA. When CdhA was overexpressed in the wild-type GAS as well as in heterologous strains, Escherichia coli and Staphylococcus aureus, we observed a distinct increase in bacterial chain length. Our data reveal that CdhA is a multifunctional protein with a major function of the N-terminal region as a cell division plane-recognizing domain and that of the C-terminal CHAP domain as a virulence-regulating domain. CdhA is thus an important therapeutic target. PMID:20643653

Pancholi, Vijay; Boël, Gregory; Jin, Hong

2010-01-01

118

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

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.

González-Páez, Gonzalo E.; Wolan, Dennis W. (Scripps)

2012-09-05

119

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 Central

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.| PMID:23989154

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

2013-01-01

120

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

PubMed

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

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

2015-01-01

121

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

PubMed Central

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

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

2015-01-01

122

Pathological fracture and pyogenic osteomyelitis in a patient with type 2 Gaucher disease.  

PubMed

In Gaucher disease (GD), enzyme replacement therapy (ERT) results in the alleviation of hematological abnormalities and visceral infiltration as well as improvement in quality of life and life-span. However, several years may be required for skeletal manifestations, which are usually observed in type 1 and 3 GD, to respond to ERT. Infants with type 2 GD rarely present skeletal manifestations because most of these patients die within the first 2 years of life before they develop skeletal involvement. The use of ERT may prolong the lifespan of these patients and influence the natural history of the disease. The present study reports a new natural history of treated GD in which a 2-year and 7-month-old girl with type 2 GD who was receiving ERT developed valproate-induced Fanconi syndrome, pathological fractures, and pyogenic osteomyelitis. In conclusion, skeletal disease may occur in any type of GD, and Fanconi syndrome may lead to severe skeletal complications in patients with GD. PMID:24412634

Hayashi, Anri; Kawakita, Rie; Kumada, Tomohiro; Nozaki, Fumihito; Hiejima, Ikuko; Miyajima, Tomoko; Kusunoki, Takashi; Fujii, Tatsuya

2014-10-01

123

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

PubMed

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

Nguyen, Sy Le Thanh; Quyen, Dinh Thi; Vu, Hong Diep

2014-01-01

124

Nucleotide sequence of conjugative prophage ?1207.3 (formerly Tn1207.3) carrying the mef(A)/msr(D) genes for e?ux resistance to macrolides in Streptococcus pyogenes  

PubMed Central

Genetic element ?1207.3 (formerly Tn1207.3) is a prophage of Streptococcus pyogenes which carries the macrolide e?ux resistance genes mef(A)/msr(D) and is capable of conjugal transfer among streptococci. Complete nucleotide sequence showed that ?1207.3 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. ?1207.3 codes for two different C-methylation systems, several phage structural genes, a lysis cassette (composed by a holin and a peptidoglycan hydrolase), and three site-specific resolvases of the serine recombinase family. PMID:25538698

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

2014-01-01

125

Pyogenic spondylitis.  

PubMed

Pyogenic spondylitis is a neurological and life threatening condition. It encompasses a broad range of clinical entities, including pyogenic spondylodiscitis, septic discitis, vertebral osteomyelitis, and epidural abscess. The incidence though low appears to be on the rise. The diagnosis is based on clinical, radiological, blood and tissue cultures and histopathological findings. Most of the cases can be treated non-operatively. Surgical treatment is required in 10-20% of patients. Anterior decompression, debridement and fusion are generally recommended and instrumentation is acceptable after good surgical debridement with postoperative antibiotic cover. PMID:22033610

Cheung, W Y; Luk, Keith D K

2012-02-01

126

RESEARCH ARTICLE Role of group A Streptococcus HtrA in  

E-print Network

RESEARCH ARTICLE Role of group A Streptococcus HtrA in the maturation of SpeB protease Jason NP) of the human pathogen Streptococcus pyogenes (group A Streptococcus; GAS) is localized to the ExB / Streptococcus pyogenes 4488 Proteomics 2007, 7, 4488­4498 1 Introduction The multifunctional chaperone

Nizet, Victor

127

Horizontal gene transfer and recombination in Streptococcus dysgalactiae subsp. equisimilis  

PubMed Central

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

McNeilly, Celia L.; McMillan, David J.

2014-01-01

128

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

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. PMID:24064215

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

2013-11-01

129

Gene Regulation in Streptococcus pneumoniae: interplay between nutrition and virulence.  

E-print Network

??abstractStreptococcus pneumoniae (the pneumococcus) is a Gram-positive bacterium, which belongs to the species of streptococci. Other pathogenic bacteria belonging to this class include Streptococcus pyogenes,… (more)

W.T. Hendriksen (Wouter)

2010-01-01

130

Streptococcus pneumoniae biofilm formation and dispersion during colonization and disease  

PubMed Central

Streptococcus pneumoniae (the pneumococcus) is a common colonizer of the human nasopharynx. Despite a low rate of invasive disease, the high prevalence of colonization results in millions of infections and over one million deaths per year, mostly in individuals under the age of 5 and the elderly. Colonizing pneumococci form well-organized biofilm communities in the nasopharyngeal environment, but the specific role of biofilms and their interaction with the host during colonization and disease is not yet clear. Pneumococci in biofilms are highly resistant to antimicrobial agents and this phenotype can be recapitulated when pneumococci are grown on respiratory epithelial cells under conditions found in the nasopharyngeal environment. Pneumococcal biofilms display lower levels of virulence in vivo and provide an optimal environment for increased genetic exchange both in vitro and in vivo, with increased natural transformation seen during co-colonization with multiple strains. Biofilms have also been detected on mucosal surfaces during pneumonia and middle ear infection, although the role of these biofilms in the disease process is debated. Recent studies have shown that changes in the nasopharyngeal environment caused by concomitant virus infection, changes in the microflora, inflammation, or other host assaults trigger active release of pneumococci from biofilms. These dispersed bacteria have distinct phenotypic properties and transcriptional profiles different from both biofilm and broth-grown, planktonic bacteria, resulting in a significantly increased virulence in vivo. In this review we discuss the properties of pneumococcal biofilms, the role of biofilm formation during pneumococcal colonization, including their propensity for increased ability to exchange genetic material, as well as mechanisms involved in transition from asymptomatic biofilm colonization to dissemination and disease of otherwise sterile sites. Greater understanding of pneumococcal biofilm formation and dispersion will elucidate novel avenues to interfere with the spread of antibiotic resistance and vaccine escape, as well as novel strategies to target the mechanisms involved in induction of pneumococcal disease.

Chao, Yashuan; Marks, Laura R.; Pettigrew, Melinda M.; Hakansson, Anders P.

2015-01-01

131

Streptococcus acidominimus causing invasive disease in humans: a case series  

PubMed Central

Introduction Streptococcus acidominimus is a member of the viridans group streptococci and is rarely pathogenic in humans, making it difficult to assess its epidemiologic and clinical significance. Case presentation We report the cases of five Han Chinese patients with invasive diseases caused by S. acidominimus over a one-year time frame. Three of the patients developed continuous fever after surgery, consisting of a successful elective laparoscopic cholecystectomy (case 1), a laparoscopic esophageal resection and gastroesophageal anastomosis (case 2), and a liver transplant in a patient with liver cancer (case 3). For these three patients, cultures of the purulent drainage material grew S. acidominimus. Case 4 concerns a 52-year-old man who developed sepsis 48 hours after hospitalization for hepatitis, liver cirrhosis and hepatitis-related glomerulonephritis. Case 5 concerns a 55-year-old woman receiving regular hemodialysis who had low-grade fever for one month. For these two patients, blood cultures grew S. acidominimus. An antimicrobial susceptibility test revealed that S. acidominimus was resistant to clindamycin and, to some degree, beta-lactam or macrolides. The S. acidominimus from the patient on hemodialysis was resistant to multiple antibiotics. Conclusion S. acidominimus is an ever-increasing cause of disease, especially in patients who are critically ill. It is showing increased resistance to antimicrobial agents, so in patients with viridans group streptococci infections, it is necessary to identify the species to improve the clinical management of S. acidominimus. PMID:24529345

2014-01-01

132

Influenza A virus facilitates Streptococcus pneumoniae transmission and disease.  

PubMed

Streptococcus pneumoniae (the pneumococcus) kills approximately 1.6 million people annually. Pneumococcal infections predominantly manifest as pneumonia, sepsis, meningitis, and otitis media. S. pneumoniae is also a member of the normal nasopharyngeal flora, colonizing up to 80% of children. Infection with influenza A virus (IAV) has been associated with both pneumococcal disease and transmission. However, to date no animal model has been available to investigate the role of IAV in the spread of S. pneumoniae. Here we investigate pneumococcal-influenza synergism with a particular focus on the role of IAV on pneumococcal transmission. Infant mice were colonized with S. pneumoniae and subsequently infected with IAV 3 d later. Using this novel model we show increased pneumococcal colonization and disease in the presence of IAV. Notably, in vivo imaging showed that IAV was essential for the transmission of S. pneumoniae from colonized ("index") mice to their naive cohoused littermates ("contacts"). Transmission occurred only when all mice were infected with IAV and was prevented when an IAV-neutralizing antibody was used to inhibit IAV replication in either index mice or contact mice. Together, these data provide novel insights into pneumococcal-influenza synergism and may indicate a previously unappreciated role of IAV in the spread of S. pneumoniae. PMID:20097876

Diavatopoulos, Dimitri A; Short, Kirsty R; Price, John T; Wilksch, Jonathan J; Brown, Lorena E; Briles, David E; Strugnell, Richard A; Wijburg, Odilia L

2010-06-01

133

Crystal structure of peptidyl-tRNA hydrolase from a Gram-positive bacterium, Streptococcus pyogenes at 2.19 Å resolution shows the closed structure of the substrate-binding cleft  

PubMed Central

Peptidyl-tRNA hydrolase (Pth) catalyses the release of tRNA and peptide components from peptidyl-tRNA molecules. Pth from a Gram-positive bacterium Streptococcus pyogenes (SpPth) was cloned, expressed, purified and crystallised. Three-dimensional structure of SpPth was determined by X-ray crystallography at 2.19 Å resolution. Structure determination showed that the asymmetric unit of the unit cell contained two crystallographically independent molecules, designated A and B. The superimposition of C? traces of molecules A and B showed an r.m.s. shift of 0.4 Å, indicating that the structures of two crystallographically independent molecules were identical. The polypeptide chain of SpPth adopted an overall ?/? conformation. The substrate-binding cleft in SpPth is formed with three loops: the gate loop, Ile91–Leu102; the base loop, Gly108–Gly115; and the lid loop, Gly136–Gly150. Unlike in the structures of Pth from Gram-negative bacteria, the entry to the cleft in the structure of SpPth appeared to be virtually closed. However, the conformations of the active site residues were found to be similar. PMID:25389518

Singh, Avinash; Gautam, Lovely; Sinha, Mau; Bhushan, Asha; Kaur, Punit; Sharma, Sujata; Singh, T.P.

2014-01-01

134

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

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

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

2013-09-20

135

Complete Genome Sequence of a Virulent Streptococcus agalactiae Strain, 138P, Isolated from Diseased Nile Tilapia  

PubMed Central

Streptococcus agalactiae strain 138P was isolated from the kidney of diseased Nile tilapia in Idaho during a 2007 streptococcal disease outbreak. The full genome sequence of S. agalactiae 138P is 1,838,701 bp. The availability of this genome will allow comparative genomics analysis to identify genes for antigen discovery and vaccine development. PMID:24744333

Zhang, Dunhua

2014-01-01

136

Complete Genome Sequence of a Virulent Streptococcus agalactiae Strain, 138P, Isolated from Diseased Nile Tilapia.  

PubMed

Streptococcus agalactiae strain 138P was isolated from the kidney of diseased Nile tilapia in Idaho during a 2007 streptococcal disease outbreak. The full genome sequence of S. agalactiae 138P is 1,838,701 bp. The availability of this genome will allow comparative genomics analysis to identify genes for antigen discovery and vaccine development. PMID:24744333

Pridgeon, Julia W; Zhang, Dunhua

2014-01-01

137

Colonization with antibiotic-resistant Streptococcus pneumoniae in children with sickle cell disease  

Microsoft Academic Search

OBJECTIVE: Because of a susceptibility to severe pneumococcal infection, children with sickle cell disease (SCD) routinely receive penicillin prophylaxis. Increasing rates of penicillin resistance have been reported throughout the world. Our objective was to assess the prevalence of nasopharyngeal colonization with Streptococcus pneumoniae and to assess the antimicrobial susceptibility of the organisms in children with SCD. STUDY DESIGN: Nasopharyngeal cultures

Russell W. Steele; Rajasekharan Warrier; Patrick J. Unkel; Bertrand J. Foch; Richard F. Howes; Sanjay Shah; Karen Williams; Sheila Moore; Sue J. Jue

1996-01-01

138

Complete Genome Sequence of a Virulent Strain, Streptococcus iniae ISET0901, Isolated from Diseased Tilapia  

PubMed Central

Streptococcus iniae ISET0901 is a virulent strain isolated in 2007 from diseased tilapia. Its full genome is 2,070,856 bp. The availability of this genome will allow comparative genomics to identify virulence genes important for the pathogenesis of streptococcosis caused by S. iniae, as well as possible immunogens for vaccine development. PMID:24903878

Zhang, Dunhua; Zhang, Lee

2014-01-01

139

Group A Streptococcus Endometritis following Medical Abortion  

PubMed Central

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

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

2014-01-01

140

Growth Inhibition of Streptococcus pyogenes by Bacitracin  

NSDL National Science Digital Library

This blood agar plate demonstrates that the beta-hemolytic colonies were sensitive to bacitracin and did not grow around the antibiotic containing disc. It also demonstrates that other colony types are present in this sample that are not hemolytic.

American Society For Microbiology;

2002-01-01

141

From the Cover: Crystal structure of the zymogen form of the group A Streptococcus virulence factor SpeB: An integrin-binding cysteine protease  

Microsoft Academic Search

Pathogenic bacteria secrete protein toxins that weaken or disable their host, and thereby act as virulence factors. We have determined the crystal structure of streptococcal pyrogenic exotoxin B (SpeB), a cysteine protease that is a major virulence factor of the human pathogen Streptococcus pyogenes and participates in invasive disease episodes, including necrotizing fasciitis. The structure, determined for the 40-kDa precursor

Todd F. Kagawa; Jakki C. Cooney; Heather M. Baker; Sean McSweeney; Mengyao Liu; Siddeswar Gubba; James M. Musser; Edward N. Baker

2000-01-01

142

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

PubMed Central

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

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

143

Laboratory detection of group B Streptococcus for prevention of perinatal disease.  

PubMed

Group B Streptococcus (GBS) or Streptococcus agalactiae emerged in the 1970s as the leading cause of neonatal morbidity and mortality. Today, GBS remains one of the leading causes of sepsis and meningitis in newborns despite important prevention efforts, including the issuance of recommendations for prevention of perinatal GBS disease by the American College of Obstetricians and Gynecologists, the Centers for Disease Control and Prevention, and the American Academy of Pediatrics in 1996/1997. The gastrointestinal tract is the natural human reservoir for GBS and is the likely source of vaginal colonization. GBS disease in newborns usually results from ascending spread of GBS into the amniotic fluid, which leads to neonatal colonization and to invasive disease in some infants. This review analyzes the various laboratory methods available for the detection of GBS from clinical samples collected from pregnant women and will discuss their impact in the prevention of neonatal GBS infections and in the rationalization of antibiotic use. The recent commercial availability of a rapid and highly sensitive real-time polymerase chain reaction assay suitable for the specific detection of GBS from vagino-rectal samples obtained from pregnant women during delivery, which is approved by the US Food and Drug Administration, provides improvements in the accuracy and rapidity of GBS colonization screening compared to the standard culture-based method using the recommended selective enrichment broth. PMID:15258832

Picard, F J; Bergeron, M G

2004-09-01

144

Identification and typing of pyogenic streptococci by enzyme electrophoretic polymorphism.  

PubMed

Polyacrylamide-agarose gel electrophoresis was used to study polymorphism of lactate dehydrogenase (LDH), nucleoside phosphorylase (NSP), phosphoglucose isomerase (PGI), hydroxybutyrate dehydrogenase (HBD), adenylate kinase (ADK) and esterases of 44 strains of Streptococcus pyogenes, 25 group G streptococcal strains, 11 "S. equisimilis" strains, seven S. dysgalactiae strains, four S. canis strains, three S. equi strains and seven S. zooepidemicus strains. Analysis of LDH, NSP, PGI, HBD and ADK provided valuable interspecies differentiation, by showing that four groups of strains corresponded to the four known DNA homology groups. Esterases showed greater intraspecies variation than the other enzymes. The combined analysis of the six enzymes indicated 31 zymotypes among S. pyogenes, 14 in group G streptococci and 11 in "S. equisimilis" strains. This was shown to be an effective technique for typing pyogenic streptococci. PMID:7791210

Bert, F; Picard, B; Lambert-Zechovsky, N; Goullet, P

1995-06-01

145

Isolation and characterization of Streptococcus sp. from diseased flounder (Paralichthys olivaceus) in Jeju Island  

PubMed Central

Streptococcus sp. is gram-positive coccus that causes streptococcal infections in fish due to intensification of aquaculture and caused significant economic losses in fish farm industry. A streptococcal infection occurred from cultured diseased olive flounder (Paralichthys olivaceus) in May, 2005 at a fish farm in Jeju Island, Korea. The diseased flounder exhibited bilateral exophthalmic eyes and rotten gills; water temperature was 16~18? when samples were collected. Of the 22 fish samples collected, 3 samples were identified as Lactococcus garvieae and 18 samples were identified as Streptococcus parauberis by culture-based, biochemical test. Serological methods such as slide agglutination, hemolysis and antimicrobial susceptibility test were also used as well as multiplex PCR-based method to simultaneously detect and confirm the pathogens involved in the infection. S. parauberis and L. garvieae have a target region of 700 and 1100 bp., respectively. One fish sample was not identified because of the difference in the different biochemical and serological tests and was negative in PCR assay. In the present study, it showed that S. parauberis was the dominant species that caused streptococcosis in the cultured diseased flounder. PMID:16434850

Baeck, Gun Wook; Kim, Ji Hyung; Gomez, Dennis Kaw

2006-01-01

146

Role for Streptococcal Collagen-Like Protein 1 in M1T1 Group A Streptococcus Resistance to Neutrophil Extracellular Traps  

E-print Network

Role for Streptococcal Collagen-Like Protein 1 in M1T1 Group A Streptococcus Resistance of the most highly expressed proteins in the invasive M1T1 serotype group A Streptococcus (GAS), a globally A Streptococcus (GAS) (Streptococcus pyogenes) is among the top 10 human pathogens worldwide and is responsible

Nizet, Victor

147

Draft Genome Sequence of Trueperella pyogenes, Isolated from the Infected Uterus of a Postpartum Cow with Metritis  

PubMed Central

Trueperella pyogenes is a common commensal bacterium and an opportunistic pathogen associated with chronic purulent disease, particularly in ruminants. We report here the genome sequence of a T. pyogenes isolate from a severe case of bovine metritis. This is the first full record of a T. pyogenes genome. PMID:24762932

Goldstone, Robert J.; Amos, Matt; Talbot, Richard; Schuberth, Hans-Joachim; Sandra, Olivier; Sheldon, I. Martin

2014-01-01

148

Draft Genome Sequence of Trueperella pyogenes, Isolated from the Infected Uterus of a Postpartum Cow with Metritis.  

PubMed

Trueperella pyogenes is a common commensal bacterium and an opportunistic pathogen associated with chronic purulent disease, particularly in ruminants. We report here the genome sequence of a T. pyogenes isolate from a severe case of bovine metritis. This is the first full record of a T. pyogenes genome. PMID:24762932

Goldstone, Robert J; Amos, Matt; Talbot, Richard; Schuberth, Hans-Joachim; Sandra, Olivier; Sheldon, I Martin; Smith, David G E

2014-01-01

149

Genetic Characterization of Streptococcus iniae in Diseased Farmed Rainbow Trout (Onchorhynchus mykiss) in Iran  

PubMed Central

Genetic characterization of strains of Streptococcus iniae recovered from morbidity and mortality of farmed rainbow trout in different provinces of Iran were studied. The Gram-positive cocci isolates were obtained from the kidney tissues of diseased rainbow trout on blood agar at 25°C for 72?h. The grown bacteria were then characterized using biochemical and molecular works. The identified 26 isolates of S. iniae producing a 513?bp in PCR procedure were then compared using random amplified polymorphic DNA (RAPD) analysis using 9 random primers. The phylogenetic tree of the RAPD product using UPMGA software included these strains in one genetic group but into two clusters. The results of this study show that S. iniae strains from the diseased rainbow trout in the north part of Iran are genetically similar to those strains in the south and west parts of the country. PMID:22550467

Erfanmanesh, A.; Soltani, M.; Pirali, E.; Mohammadian, S.; Taherimirghaed, A.

2012-01-01

150

[Late-onset group B streptococcus disease in twins delivered by caesarean section].  

PubMed

Group B Streptococcus (GBS) is a commensal pathogen of the gut microflora with a well-established role in the aetiology of early and late onset GBS infections in the newborn. The incidence of early onset infections by vertical transmission has been drastically reduced in recent decades with the use of intravenous intrapartum prophylaxis. Progress in risk factor detection and prophylaxis of late-onset infection has however remained static. The ongoing modifications and improvements of the guidelines regarding prophylaxis, risk factors and prevention of the early-onset GBS disease have not addressed late-onset GBS infection in detail. The following cases illustrate the presence of grey areas in current guidelines and in the knowledge of the pathogenesis of late-onset disease. PMID:24588958

Escolano Serrano, S; Ruiz Alcántara, I; Alfonso Diego, J; González Muñoz, A; Gastaldo Simeón, E

2015-01-01

151

Clindamycin-Resistant Group B Streptococcus and Failure of Intrapartum Prophylaxis to Prevent Early-Onset Disease  

PubMed Central

Guidelines recommend intrapartum antibiotic prophylaxis (IAP) for parturient women who have a screen positive for group B Streptococcus (GBS). Clindamycin should be used for IAP only if the maternal GBS isolate is susceptible. We report a case of clindamycin-resistant GBS disease in a newborn infant whose mother received clindamycin IAP, and we review clindamycin susceptibility testing. PMID:20056242

Blaschke, Anne J.; Pulver, Laurie S.; Korgenski, E. Kent; Savitz, Lucy A.; Daly, Judy A.; Byington, Carrie L.

2011-01-01

152

Streptococcus iniae M-Like Protein Contributes to Virulence in Fish and Is a Target for Live Attenuated  

E-print Network

Streptococcus iniae M-Like Protein Contributes to Virulence in Fish and Is a Target for Live Technologies, San Diego, California, United States of America Abstract Background: Streptococcus iniae-like regulatory gene, mgx. In contrast to the Mga locus of group A Streptococcus (GAS, S. pyogenes), scp

Nizet, Victor

153

Penicillin and cephalosporin-resistant strains of Streptococcus pneumoniae causing sepsis and meningitis in children with sickle cell disease  

Microsoft Academic Search

Objective: We investigated the possibility that antimicrobial-resistant pneumococci were causing invasive disease in children with sickle-cell disease (SCD). Study design: Records of all children with SCD observed at the Mid-South Sickle Cell Center (MSSCC) at LeBonheur Children's Medical Center were reviewed from January 1990 to June 1994. Children with SCD and pneumococcal sepsis were identified. The Streptococcus pneumoniae isolates from

P. Joan Chesney; Judith A. Wilimas; Gerald Presbury; Seema Abbasi; Robert J. Leggiadro; Yvonne Davis; Sara W. Day; Gordon E. Schutze; Winfred C. Wang

1995-01-01

154

Interkingdom Signaling Induces Streptococcus pneumoniae Biofilm Dispersion and Transition from Asymptomatic Colonization to Disease  

PubMed Central

ABSTRACT Streptococcus pneumoniae is a common human nasopharyngeal commensal colonizing 10% to 40% of healthy individuals, depending on age. Despite a low invasive disease rate, widespread carriage ensures that infection occurs often enough to make S. pneumoniae a leading bacterial cause of respiratory disease worldwide. However, the mechanisms behind transition from asymptomatic colonization to dissemination and disease in otherwise sterile sites remain poorly understood but are epidemiologically strongly linked to infection with respiratory viruses. In this report, we show that infection with influenza A virus and treatment with the resulting host signals (febrile-range temperatures, norepinephrine, extracytoplasmic ATP, and increased nutrient availability) induce the release of bacteria from biofilms in a newly developed biofilm model on live epithelial cells both in vitro and during in vivo colonization. These dispersed bacteria have distinct phenotypic properties different from those of both biofilm and broth-grown, planktonic bacteria, with the dispersed population showing differential virulence gene expression characteristics resulting in a significantly increased ability to disseminate and cause infection of otherwise sterile sites, such as the middle ear, lungs, and bloodstream. The results offer novel and important insights into the role of interkingdom signaling between microbe and host during biofilm dispersion and transition to acute disease. PMID:23882016

Marks, Laura R.; Davidson, Bruce A.; Knight, Paul R.; Hakansson, Anders P.

2013-01-01

155

Interaction of Streptococcus agalactiae and Cellular Innate Immunity in Colonization and Disease  

PubMed Central

Streptococcus agalactiae (Group B streptococcus, GBS) is highly adapted to humans, where it is a normal constituent of the intestinal and vaginal flora. Yet, GBS has highly invasive potential and causes excessive inflammation, sepsis, and death at the beginning of life, in the elderly and in diabetic patients. Thus, GBS is a model pathobiont that thrives in the healthy host, but has not lost its potential virulence during coevolution with mankind. It remains incompletely understood how the innate immune system contains GBS in the natural niches, the intestinal and genital tracts, and which molecular events underlie breakdown of mucocutaneous resistance. Newborn infants between days 7 and 90 of life are at risk of a particularly striking sepsis manifestation (late-onset disease), where the transition from colonization to invasion and dissemination, and thus from health to severe sepsis is typically fulminant and not predictable. The great majority of late-onset sepsis cases are caused by one clone, GBS ST17, which expresses HvgA as a signature virulence factor and adhesin. In mice, HvgA promotes the crossing of both the mucosal and the blood–brain barrier. Expression levels of HvgA and other GBS virulence factors, such as pili and toxins, are regulated by the upstream two-component control system CovR/S. This in turn is modulated by acidic epithelial pH, high glucose levels, and during the passage through the mouse intestine. After invasion, GBS has the ability to subvert innate immunity by mechanisms like glycerinaldehyde-3-phosphate-dehydrogenase-dependent induction of IL-10 and ?-protein binding to the inhibitory phagocyte receptors sialic acid binding immunoglobulin-like lectin 5 and 14. On the host side, sensing of GBS nucleic acids and lipopeptides by both Toll-like receptors and the inflammasome appears to be critical for host resistance against GBS. Yet, comprehensive models on the interplay between GBS and human immune cells at the colonizing site are just emerging. PMID:25400631

Landwehr-Kenzel, Sybille; Henneke, Philipp

2014-01-01

156

MOLECULAR MODELING OF STREPTOCOCCUS PNEUMONIAE  

E-print Network

MOLECULAR MODELING OF STREPTOCOCCUS PNEUMONIAE CAPSULAR POLYSACCHARIDE ANTIGENS. Michelle Kuttel Bangalore, India #12;STREPTOCOCCUS PNEUMONIAE · leading cause of disease esp. in developing world to the recent licensure of: * Poolman et al., Clin. Vaccine Immunol. 2011, 18, 327­336 #12;STREPTOCOCCUS

Kuttel, Michelle

157

Mode of action of a lysostaphin-like bacteriolytic agent produced by Streptococcus zooepidemicus 4881.  

PubMed Central

Electron microscopy of zoocin A-treated sensitive streptococcus cells revealed cytoplasmic disruption and ultimately complete rupture of the cell wall. Culture viability and optical density were shown to decrease rapidly and simultaneously in Streptococcus pyogenes FF22 but less quickly in the relatively more resistant Streptococcus mutans 10449. Zoocin A was shown to cleave hexaglycine in a colorimetric cell-free microtiter assay system, and it is concluded that the killing action of zoocin A, like that of lysostaphin, is most probably the result of direct cleavage of the peptidoglycan cross-links in the cell wall. The relationship between sensitivity to zoocin A and the peptidoglycan cross-linkage structure of Streptococcus zooepidemicus, Lactococcus spp., S. pyogenes, Streptococcus gordonii, Streptococcus oralis, S. mutans, and Streptococcus rattus has been evaluated. PMID:8953725

Simmonds, R S; Pearson, L; Kennedy, R C; Tagg, J R

1996-01-01

158

Evidence of lateral gene transfer among strains of Streptococcus zooepidemicus in weanling horses with respiratory disease.  

PubMed

Streptococcus zooepidemicus (Sz) is a tonsillar commensal of healthy horses but with potential to opportunistically invade the lower respiratory tract. Sz is genetically variable and recombinogenic based on analysis of gene sequences including szp, szm and MLST data. Although a variety of serovars of the protective SzP are commonly harbored in the tonsils of the same horse, lower respiratory infections usually involve a single clone. Nevertheless, isolation of specific clones from epizootics of respiratory disease has been recently reported in horses and dogs in N. America, Europe and Asia. In this report, we provide evidence suggestive of lateral gene exchange and recombination between strains of Sz from cases of respiratory disease secondary to experimental equine herpes 1 virus infection in an isolated group of weanling horses and ponies. Nasal swabs of 13 of 18 weanlings with respiratory disease yielded mucoid colonies of Sz following culture. Comparison of arcC, nrdE, proS, spi, tdk, tpi and yqiL of these Sz revealed 3 Clades. Clade-1 (ST-212) and 2 (ST-24) were composed of 7 and 3 isolates, respectively. ST-24 and 212 differed in all 7 housekeeping as well as szp and szm alleles. Two isolates of Clade-1 were assigned to ST-308, a single locus variant of ST-212 that contained the proS-16 allele sequenced in ST-24. One isolate of ST-308 contained szm-2, the same allele sequenced in Clade 2 isolates; the other was positive for the szp-N2HV2 allele of Clade 2. These observations are consistent with gene transfer between Sz in the natural host and may explain formation of novel clones that invade the lower respiratory tract or cause epizootics of respiratory disease in dogs and horses. PMID:24263112

Velineni, Sridhar; Breathnach, Cormac C; Timoney, John F

2014-01-01

159

The economic costs of Group B Streptococcus (GBS) disease: prospective cohort study of infants with GBS disease in England.  

PubMed

The objective of this study was to estimate the economic costs over the first 2 years of life of Group B Streptococcus (GBS) disease occurring in infants less than 90 days of age. A cost analysis was conducted using a prospective cohort of children born between 2000 and 2003 in the Greater London, Oxford, Portsmouth and Bristol areas of England. Unit costs were applied to estimates of the health and social resource use made by 138 infants diagnosed with GBS disease and 305 non-GBS controls matched for birth weight and hospital stay and time of birth. The health and social care costs for infants exposed to GBS disease were analysed in a multiple linear regression model. The mean health and social care cost over the first 2 years of life was estimated at pound11,968.9 for infants with GBS, compared to pound6,260.7 for the non-GBS controls; a mean cost difference of pound5,708.1 (bootstrap 95% CI pound2,977.1, pound8,391.2, P=0.03). After adjusting for gestational age and other potential confounders in a multiple linear regression, mean societal costs was pound6,144.7 higher among GBS cases than among non-GBS controls (P<0.001). This study shows that the health and social care costs for infants with GBS disease is, on average, two-fold higher during the first 2 years of life than for infants without GBS disease. These data should be used to inform policy decisions regarding the cost-effectiveness of prevention and treatment strategies for GBS disease during early childhood. PMID:19002511

Schroeder, Elizabeth-Ann; Petrou, Stavros; Balfour, Gail; Edamma, Oya; Heath, Paul T

2009-07-01

160

Streptococcus dysgalactiae subsp. equisimilis bacteremia: an emerging infection.  

PubMed

The importance of group C and G Streptococcus dysgalactiae subspecies equisimilis (S. dysgalactiae subsp. equisimilis) as a significant pathogen has recently been better recognized. S. dysgalactiae subsp. equisimilis disease can range in severity from milder skin and soft-tissue conditions such as wound infection, erysipelas, and cellulitis, to life-threatening necrotizing fasciitis and streptococcal toxic shock syndrome, thus sharing the clinical picture with S. pyogenes. The most common clinical manifestation of bacteremia is cellulitis. An increase in the incidence of S. dysgalactiae subsp. equisimilis bacteremia has been recognized. Invasive forms of this infection are most commonly found in elderly patients with underlying comorbidities and skin breakdown. The case fatality in bacteremia has been reported to be 15-18%. In this review, the epidemiology, clinical characteristics, and emm types of S. dysgalactiae subsp. equisimilis bacteremia are summarized. PMID:24682845

Rantala, S

2014-08-01

161

Antimicrobial Effect of Lactobacillus reuteri on Cariogenic Bacteria Streptococcus gordonii, Streptococcus mutans, and Periodontal Diseases Actinomyces naeslundii and Tannerella forsythia.  

PubMed

Lactic acid bacteria (LAB) are well known for their beneficial effects on human health in the intestine and immune system; however, there are few studies on the impact they can generate in oral health. The aim of this study was to test and compare in vitro antimicrobial activity of L. reuteri on pathogenic bacteria involved in the formation of dental caries: S. mutans, S. gordonii, and periodontal disease: A. naeslundii and T. forsythia. Also, we determined the growth kinetics of each bacterium involved in this study. Before determining the antimicrobial action of L. reuteri on cariogenic bacteria and periodontal disease, the behavior and cell development time of each pathogenic bacterium were studied. Once the conditions for good cell growth of each of selected pathogens were established according to their metabolic requirements, maximum exponential growth was determined, this being the reference point for analyzing the development or inhibition by LAB using the Kirby Bauer method. Chlorhexidine 0.12 % was positive control. L. reuteri was shown to have an inhibitory effect against S. mutans, followed by T. forsythia and S. gordonii, and a less significant effect against A. naeslundii. Regarding the effect shown by L. reuteri on the two major pathogens, we consider its potential use as a possible functional food in the prevention or treatment of oral diseases. PMID:25422124

Baca-Castañón, Magda Lorena; De la Garza-Ramos, Myriam Angélica; Alcázar-Pizaña, Andrea Guadalupe; Grondin, Yohann; Coronado-Mendoza, Anahí; Sánchez-Najera, Rosa Isela; Cárdenas-Estrada, Eloy; Medina-De la Garza, Carlos Eduardo; Escamilla-García, Erandi

2014-11-25

162

Review on the association of Group B Streptococcus capsular antibody and protection against invasive disease in infants.  

PubMed

A trivalent Group B streptococcus (GBS) polysaccharide-protein conjugate vaccine for vaccination of pregnant women is under development to protect their newborns against invasive GBS disease. Establishing sero-correlates of protection against invasive GBS disease in infants could expedite the licensure pathway of polysaccharide-protein conjugate vaccine. A systematic review of studies reporting on the association of capsular antibodies and invasive GBS disease in infants and colonization in women or newborns was undertaken. Most studies that described maternal and/or infant capsular antibody levels in infants with invasive GBS disease identified an association between low capsular antibody levels in invasive GBS cases compared to controls. Different assay methods and the lack of standardized reference ranges for serotype-specific antibody levels makes it difficult to select an antibody level that may be used as a reliable sero-correlate of protection. Further studies using standardized methods are warranted. PMID:25242617

Dangor, Ziyaad; Kwatra, Gaurav; Izu, Alane; Lala, Sanjay G; Madhi, Shabir A

2015-01-01

163

Streptococcus pneumoniae in Urinary Tracts of Children with Chronic Kidney Disease  

PubMed Central

Streptococcus pneumoniae is not commonly considered an agent of urinary tract infections. We report 3 children with urinary tract abnormalities who had high numbers of S. pneumoniae in their urine (>104 CFU/mL) and varying clinical symptoms. PMID:21192871

Zimmermann, Stefan

2011-01-01

164

Responses of innate immune cells to group A Streptococcus  

PubMed Central

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

Fieber, Christina; Kovarik, Pavel

2014-01-01

165

Streptococcus pyogenes Sternoclavicular Septic Arthritis in a Healthy Adult  

PubMed Central

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

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

2014-01-01

166

Streptococcus pyogenes activates human plasmacytoid and myeloid dendritic cells  

Microsoft Academic Search

Human peripheral blood contains two major dendritic cell (DC) populations, namely CD11c-CD123 plasmacytoid DCs (PDCs) and CD11cCD123- myeloid DCs (MDCs). Although the activation of these DC types by various TLR ligands has been relatively well-characterized, less is known about the ability of whole live bacteria to induce PDC and MDC activation. In the present report, we have compared the activation

Ville Veckman; Ilkka Julkunen

2007-01-01

167

Systemic disease during Streptococcus pneumoniae acute lung infection requires 12-lipoxygenase-dependent inflammation  

PubMed Central

Acute pulmonary infection by Streptococcus pneumoniae is characterized by high bacterial numbers in the lung, a robust alveolar influx of polymorphonuclear cells (PMNs) and a risk of systemic spread of the bacterium. We investigated host-mediators of S. pneumoniae-induced PMN migration and the role of inflammation in septicemia following pneumococcal lung infection. Hepoxilin A3 (HXA3) is a PMN chemoattractant and a metabolite of the 12-lipoxygenase (12-LOX) pathway. We observed that S. pneumoniae infection induced the production of 12-lipoxygenase in cultured pulmonary epithelium and in the lungs of infected mice. Inhibition of the 12- LOX pathway prevented pathogen-induced PMN transepithelial migration in vitro and dramatically reduced lung inflammation upon high-dose pulmonary challenge with S. pneumoniae in vivo, thus implicating HXA3 in pneumococcus-induced pulmonary inflammation. PMN basolateral-to-apical transmigration in vitro significantly increased apical-to-basolateral transepithelial migration of bacteria. Mice suppressed in the expression of 12-lipoxygenase exhibited little or no bacteremia and survived an otherwise lethal pulmonary challenge. Our data suggest that pneumococcal pulmonary inflammation is required for high level bacteremia and systemic infection, partly by disrupting lung epithelium through 12-LOX-dependent HXA3 production and subsequent PMN transepithelial migration. PMID:24089193

Bhowmick, Rudra; Maung, Nang; Hurley, Bryan P.; Ghanem, Elsa Bou; Gronert, Karsten

2013-01-01

168

Towards Control of Streptococcus iniae  

PubMed Central

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

Barnes, Andrew C.

2009-01-01

169

Lyme disease and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS): an overview  

PubMed Central

Lyme disease (LD) is a complex, multisystemic illness. As the most common vector- borne disease in the United States, LD is caused by bacterial spirochete Borrelia burgdorferi sensu stricto, with potential coinfections from agents of anaplasmosis, babesiosis, and ehrlichiosis. Persistent symptoms and clinical signs reflect multiorgan involvement with episodes of active disease and periods of remission, not sparing the coveted central nervous system. The capability of microorganisms to cause and exacerbate various neuropsychiatric pathology is also seen in pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS), a recently described disorder attributed to bacterium Streptococcus pyogenes of group A beta-hemolytic streptococcus in which neurologic tics and obsessive-compulsive disorders are sequelae of the infection. In the current overview, LD and PANDAS are juxtaposed through a review of their respective infectious etiologies, clinical presentations, mechanisms of disease development, courses of illness, and treatment options. Future directions related to immunoneuropsychiatry are also discussed. PMID:22393303

Rhee, Hanna; Cameron, Daniel J

2012-01-01

170

Pyogenic Sacroiliitis and Pyomyositis in a Patient with Systemic Lupus Erythematous  

PubMed Central

Pyogenic sacroiliitis and pyomyositis are uncommon infectious diseases and their diagnoses are often delayed. They are typically seen in children and young adults and are rare in middle-aged people especially in those affected by rheumatic diseases. We present the first case of a Staphylococcus aureus related pyogenic sacroiliitis associated with iliacus and gluteal pyomyositis occurring in a patient with systemic lupus erythematosus. Antibiotic treatment was administered for a total of 6 weeks with a total recovery. Pyogenic sacroiliitis and pyomyositis, although remaining rare events, should be remembered as severe complications in immunosuppressed patients with inflammatory diseases. Early clinical suspicion, imaging diagnosis, and adequate therapy are decisive for the satisfactory outcome. PMID:25165609

Chebbi, Wafa; Jerbi, Saida; Kessomtini, Wassia; Fradi, Asma; Sfar, Mohamed Habib

2014-01-01

171

Characterization of a mucoid clone of Streptococcus zooepidemicus from an epizootic of equine respiratory disease in New Caledonia.  

PubMed

Streptococcus equi subspecies zooepidemicus (Sz) is a tonsillar and mucosal commensal of healthy horses with the potential to cause opportunistic infections of the distal respiratory tract stressed by virus infection, transportation, training or high temperature. The invasive clone varies from horse to horse with little evidence of lateral transmission in the group. Tonsillar isolates are non-mucoid although primary isolates from opportunist lower respiratory tract infections may initially be mucoid. In this study, a novel stably mucoid Sz (SzNC) from a clonal epizootic of respiratory disease in horses in different parts of New Caledonia is described. SzNC (ST-307) was isolated in pure culture from transtracheal aspirates and as heavy growths from 80% of nasal swabs (n=31). Only 4% of swabs from unaffected horses (n=25) yielded colonies of Sz. A viral etiology was ruled out based on culture and early/late serum antibody screening. Evidence for clonality of SzNC included a mucoid colony phenotype, SzP and SzM sequences, and multilocus sequence typing. SzNC, with the exception of isolates at the end of the outbreak, was hyaluronidase positive. Its SzP protein was composed of an N2 terminal, and HV4 variable region motifs and 18 carboxy terminal PEPK repeats. Biotin labeling of surface proteins revealed DnaK and alanyl-tRNA synthetase (AlaS) on the surface of clonal isolates, but not on non-clonal non-mucoid Sz from horses in the epizootic or unrelated US isolates. Reactivity of these proteins and SzP with convalescent serum indicated expression during infection. PMID:24618399

Velineni, Sridhar; Desoutter, Denise; Perchec, Anne-Marie; Timoney, John F

2014-04-01

172

Structural and functional analysis of the fibronectin-binding protein FNE from Streptococcus equi spp. equi.  

PubMed

Streptococcus equi is a horse pathogen belonging to Lancefield group C. Infection by S. equi ssp. equi causes strangles, a serious and highly contagious disease of the upper respiratory tract. S. equi ssp. equi secretes a fibronectin (Fn)-binding protein, FNE, that does not contain cell wall-anchoring motifs. FNE binds to the gelatin-binding domain (GBD) of Fn, composed of the motifs (6) FI (12) FII (789) FI . FNE lacks the canonical Fn-binding peptide repeats observed in many microbial surface components recognizing adhesive matrix molecules. We found that the interaction between FNE and the human GBD is mediated by the binding of the disordered C-terminal region (residues 208-262) of FNE to the (789) FI GBD subfragment. The crystal structure of FNE showed that it is similar to the minor pilus protein Spy0125 of Streptococcus pyogenes, found at the end of pilus polymers and responsible for adhesion. FNE and Spy0125 both have a superimposable internal thioester bond between highly conserved Cys and Gln residues. Small-angle X-ray scattering of the FNE-(789) FI complex provided a model that aligns the C-terminal peptide of FNE with the E-strands of the FI domains, adopting the ?-zipper extension model observed in previous structures of microbial surface components recognizing adhesive matrix molecule adhesion peptides bound to FI domains. PMID:25290767

Tiouajni, Mounira; Durand, Dominique; Blondeau, Karine; Graille, Marc; Urvoas, Agathe; Valerio-Lepiniec, Marielle; Guellouz, Asma; Aumont-Nicaise, Magali; Minard, Philippe; van Tilbeurgh, Herman

2014-12-01

173

Outbreak of Group A beta hemolytic Streptococcus pharyngitis in a Peruvian military facility, April 2012.  

PubMed

Group A Streptococcus (GAS), or Streptococcus pyogenes, is a common cause of acute pharyngitis as well as other diseases. Closed populations such as those living on military bases, nursing homes, and prisons are particularly vulnerable to GAS outbreaks due to crowding that facilitates person-to-person transmission. This report details a large outbreak of GAS pharyngitis at a Peruvian military training facility near Lima, Peru, in April 2012. Initial findings showed 145 cases. However, as the investigation continued it was revealed that some trainees may have concealed their illness to avoid real or perceived negative consequences of seeking medical care. A subsequent anonymous survey of all trainees revealed at least 383 cases of pharyngitis among the facility's 1,549 trainees and an attack rate of 34 percent among the 1,137 respondents. The epidemic curve revealed a pattern consistent with routine person-to-person transmission, although a point-source initiating event could not be excluded. Laboratory results showed GAS emm type 80.1 to be the culprit pathogen, an organism not commonly implicated in outbreaks of GAS in the Americas. Barious unique and illustrative features of outbreak investigation in military facilities and populations are discussed. PMID:23819536

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

174

Identification of ?-haemolysin-encoding genes in Streptococcus anginosus.  

PubMed

Streptococcus anginosus is an emerging pathogen, but little is known about its virulence factors. To detect the genes responsible for ?-haemolysis we performed genomic mutagenesis of the ?-haemolytic S. anginosus type strain ATCC 12395 using the vector pGhost9:ISS1. Integration site analysis of 15 non-haemolytic mutants identified a gene cluster with high homology to the genes of the streptolysin S (SLS) encoding sag gene cluster of S. pyogenes. The gene cluster harbours 10 open reading frames displaying significant similarities to the S. pyogenes genes sagA-sagI, with the identities on protein level ranging from 38 to 87%. Complementation assays of S. anginosus sagB and sagD integration mutants with the respective genes confirmed their importance for ?-haemolysin production and suggest the presence of post-translational modifications in S. anginosus SLS similar to SLS of S. pyogenes. Characterization of the S. anginosus haemolysin in comparison to the S. pyogenes SLS showed that the haemolysin is surface bound, but in contrast to S. pyogenes neither fetal calf serum nor RNA was able to stabilize the haemolysin of S. anginosus in culture supernatants. Inhibition of ?-haemolysis by polyethylene glycol of different sizes was carried out, giving no evidence of a pore-forming haemolytic mechanism. Analysis of a whole genome shotgun sequence of Streptococcus constellatus, a closely related streptococcal species that belongs to the S. anginosus group, revealed a similar sag gene cluster. Employing a genomic mutagenesis strategy we were able to determine an SLS encoding gene cluster in S. anginosus and demonstrate its importance for ?-haemolysin production in S. anginosus. PMID:23594064

Asam, D; Mauerer, S; Walheim, E; Spellerberg, B

2013-08-01

175

Comparative phylogenomics of Streptococcus pneumoniae isolated from invasive disease and nasopharyngeal carriage from West Africans  

PubMed Central

Background We applied comparative phylogenomics (whole genome comparisons of microbes using DNA microarrays combined with Bayesian-based phylogenies) to investigate S. pneumoniae isolates from West Africa, with the aim of providing insights into the pathogenicity and other features related to the biology of the organism. The strains investigated comprised a well defined collection of 58 invasive and carriage isolates that were sequenced typed and included eight different S. pneumoniae serotypes (1, 3, 5, 6A, 11, 14, 19?F and 23?F) of varying invasive disease potential. Results The core genome of the isolates was estimated to be 38% and was mainly represented by gene functional categories associated with housekeeping functions. Comparison of the gene content of invasive and carriage isolates identified at least eleven potential genes that may be important in virulence including surface proteins, transport proteins, transcription factors and hypothetical proteins. Thirteen accessory regions (ARs) were also identified and did not show any loci association with the eleven virulence genes. Intraclonal diversity (isolates of the same serotype and MLST but expressing different patterns of ARs) was observed among some clones including ST 1233 (serotype 5), ST 3404 (serotype 5) and ST 3321 (serotype 14). A constructed phylogenetic tree of the isolates showed a high level of heterogeneity consistent with the frequent S. pneumoniae recombination. Despite this, a homogeneous clustering of all the serotype 1 strains was observed. Conclusions Comparative phylogenomics of invasive and carriage S. pneumoniae isolates identified a number of putative virulence determinants that may be important in the progression of S. pneumoniae from the carriage phase to invasive disease. Virulence determinants that contribute to S. pneumoniae pathogenicity are likely to be distributed randomly throughout its genome rather than being clustered in dedicated loci or islands. Compared to other S. pneumoniae serotypes, serotype 1 appears most genetically uniform. PMID:23107513

2012-01-01

176

Necrotizing fasciitis resulting from human bites: A report of two cases of disease caused by group A streptococcus  

PubMed Central

Necrotizing fasciitis is a serious and potentially life-threatening condition. Although bite wounds are common, they are not frequently reported as a cause of necrotizing fasciitis. In the present article, two cases of bite-associated necrotizing fasciitis caused by group A streptococcus are reported. Previously published cases are also reviewed. PMID:18159548

Sikora, Christopher A; Spielman, Jack; MacDonald, Kerry; Tyrrell, Gregory J; Embil, John M

2005-01-01

177

Identification of a Novel Virulence Determinant with Serum Opacification Activity in Streptococcus suis  

PubMed Central

Streptococcus suis serotype 2 is a porcine and human pathogen with adhesive and invasive properties. In other streptococci, large surface-associated proteins (>100 kDa) of the MSCRAMM family (microbial surface components recognizing adhesive matrix molecules) are key players in interactions with host tissue. In this study, we identified a novel opacity factor of S. suis (OFS) with structural homology to members of the MSCRAMM family. The N-terminal region of OFS is homologous to the respective regions of fibronectin-binding protein A (FnBA) of Streptococcus dysgalactiae and the serum opacity factor (SOF) of Streptococcus pyogenes. Similar to these two proteins, the N-terminal domain of OFS opacified horse serum. Serum opacification activity was detectable in sodium dodecyl sulfate extracts of wild-type S. suis but not in extracts of isogenic ofs knockout mutants. Heterologous expression of OFS in Lactococcus lactis demonstrated that a high level of expression of OFS is sufficient to provide surface-associated serum opacification activity. Furthermore, serum opacification could be inhibited by an antiserum against recombinant OFS. The C-terminal repetitive sequence elements of OFS differed significantly from the respective repeat regions of FnBA and SOF as well as from the consensus sequence of the fibronectin-binding repeats of MSCRAMMs. Accordingly, fibronectin binding was not detectable in recombinant OFS. To investigate the putative function of OFS in the pathogenesis of invasive S. suis diseases, piglets were experimentally infected with an isogenic mutant strain in which the ofs gene had been knocked out by an in-frame deletion. The mutant was severely attenuated in virulence but not in colonization, demonstrating that OFS represents a novel virulence determinant of S. suis. PMID:17057090

Baums, Christoph G.; Kaim, Ute; Fulde, Marcus; Ramachandran, Girish; Goethe, Ralph; Valentin-Weigand, Peter

2006-01-01

178

Comparison of Pyogenic Spondylitis and Tuberculous Spondylitis  

PubMed Central

Pyogenic spondylitis and tuberculous spondylitis are common causes of spinal infection. It is difficult to differentiate tuberculous spondylitis and pyogenic spondylitis clinically and radiologically. Recently magnetic resonance imaging has been reported to be beneficial for early diagnosis and differential diagnosis of the spondylitis, and is being used extensively for diagnosis. However, the diagnosis must be considered in combination with corresponding changes in clinical manifestations, radiological findings, blood and tissue cultures and histopathological findings. Conservative treatments, including antimicrobial medications, are started initially. Surgical treatments, which include anterior or posterior approach, single-stage or two-stage surgery, with or without instrumentation, may be performed as indicated. PMID:24761207

2014-01-01

179

Camel Streptococcus agalactiae populations are associated with specific disease complexes and acquired the tetracycline resistance gene tetM via a Tn916-like element  

PubMed Central

Camels are the most valuable livestock species in the Horn of Africa and play a pivotal role in the nutritional sustainability for millions of people. Their health status is therefore of utmost importance for the people living in this region. Streptococcus agalactiae, a Group B Streptococcus (GBS), is an important camel pathogen. Here we present the first epidemiological study based on genetic and phenotypic data from African camel derived GBS. Ninety-two GBS were characterized using multilocus sequence typing (MLST), capsular polysaccharide typing and in vitro antimicrobial susceptibility testing. We analysed the GBS using Bayesian linkage, phylogenetic and minimum spanning tree analyses and compared them with human GBS from East Africa in order to investigate the level of genetic exchange between GBS populations in the region. Camel GBS sequence types (STs) were distinct from other STs reported so far. We mapped specific STs and capsular types to major disease complexes caused by GBS. Widespread resistance (34%) to tetracycline was associated with acquisition of the tetM gene that is carried on a Tn916-like element, and observed primarily among GBS isolated from mastitis. The presence of tetM within different MLST clades suggests acquisition on multiple occasions. Wound infections and mastitis in camels associated with GBS are widespread and should ideally be treated with antimicrobials other than tetracycline in East Africa. PMID:24083845

2013-01-01

180

Camel Streptococcus agalactiae populations are associated with specific disease complexes and acquired the tetracycline resistance gene tetM via a Tn916-like element.  

PubMed

Camels are the most valuable livestock species in the Horn of Africa and play a pivotal role in the nutritional sustainability for millions of people. Their health status is therefore of utmost importance for the people living in this region. Streptococcus agalactiae, a Group B Streptococcus (GBS), is an important camel pathogen. Here we present the first epidemiological study based on genetic and phenotypic data from African camel derived GBS. Ninety-two GBS were characterized using multilocus sequence typing (MLST), capsular polysaccharide typing and in vitro antimicrobial susceptibility testing. We analysed the GBS using Bayesian linkage, phylogenetic and minimum spanning tree analyses and compared them with human GBS from East Africa in order to investigate the level of genetic exchange between GBS populations in the region. Camel GBS sequence types (STs) were distinct from other STs reported so far. We mapped specific STs and capsular types to major disease complexes caused by GBS. Widespread resistance (34%) to tetracycline was associated with acquisition of the tetM gene that is carried on a Tn916-like element, and observed primarily among GBS isolated from mastitis. The presence of tetM within different MLST clades suggests acquisition on multiple occasions. Wound infections and mastitis in camels associated with GBS are widespread and should ideally be treated with antimicrobials other than tetracycline in East Africa. PMID:24083845

Fischer, Anne; Liljander, Anne; Kaspar, Heike; Muriuki, Cecilia; Fuxelius, Hans-Henrik; Bongcam-Rudloff, Erik; de Villiers, Etienne P; Huber, Charlotte A; Frey, Joachim; Daubenberger, Claudia; Bishop, Richard; Younan, Mario; Jores, Joerg

2013-01-01

181

Emended Descriptions and Recognition of Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus as Distinct Species  

Microsoft Academic Search

Strains currently classified as Streptococcus anginosus include strains previously identified as Streptococcus constellatus (Prevot 1924) Holdeman and Moore 1974, Streptococcus intermedius (Prevot 1925), and \\

ROBERT A. WHILEY; DAVID BEIGHTON

182

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

PubMed Central

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

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

2013-01-01

183

Pyogenic flexor tenosynovitis associated with Cellulosimicrobium cellulans.  

PubMed

Cellulosimicrobium cellulans, formerly known as Oerskovia xanthineolytica, is a rare human pathogen, often in association with a foreign body. A case of pyogenic flexor tenosynovitis associated with C. cellulans in an immunocompetent boy is described, underlining the importance of prompt surgical and microbiologic evaluation. PMID:18832122

Tucker, Joseph D; Montecino, Rafael; Winograd, Jonathan M; Ferraro, Maryjane; Michelow, Ian C

2008-12-01

184

Pyogenic Flexor Tenosynovitis Associated with Cellulosimicrobium cellulans?  

PubMed Central

Cellulosimicrobium cellulans, formerly known as Oerskovia xanthineolytica, is a rare human pathogen, often in association with a foreign body. A case of pyogenic flexor tenosynovitis associated with C. cellulans in an immunocompetent boy is described, underlining the importance of prompt surgical and microbiologic evaluation. PMID:18832122

Tucker, Joseph D.; Montecino, Rafael; Winograd, Jonathan M.; Ferraro, MaryJane; Michelow, Ian C.

2008-01-01

185

Streptococcus Dysgalactiae Subspecies Dysgalactiae Infection after Total Knee Arthroplasty: A Case Report  

PubMed Central

Streptococcus dysgalactiae subspecies dysgalactiae (SDSD), Lancefield group C streptococcus, is an animal pathogen which often causes pyogenic infection in domestic animals. Human infection by SDSD has been reported as a cellulitis on the upper arm, but a prosthetic joint infection caused by SDSD after total knee arthroplasty (TKA) has not yet been reported in the literature demonstrating that its clinical manifestation and management have not been well established. In this case report, we aimed to present a case of SDSD prosthetic joint infection after TKA, which was successfully treated by two-stage re-implantation with an application of antibiotic-impregnated cement spacer. PMID:22708114

Park, Man Jun; Jung, Chul-Young; Ko, Young-Chul; Kim, Young-June; Kim, Chang-kyu; Kang, Eun-Jin

2012-01-01

186

A Case of Acute Pyogenic Sacroiliitis and Bacteremia Caused by Community-Acquired Methicillin-Resistant Staphylococcus aureus.  

PubMed

Pyogenic sacroiliitis is a rare osteoarticular infection, occurring most frequently in children and young adults. Diagnosis of the disease is challenging because of a general lack of awareness of the disease and its nonspecific signs and symptoms. Staphylococcus aureus is the most common causative bacteria in pyogenic sacroiliitis. Methicillin-resistant S. aureus (MRSA) has typically been considered a hospital-associated pathogen; however, community-acquired (CA)-MRSA infections are becoming increasingly common in Korea. We report the first domestic case of acute pyogenic sacroiliitis with abscess and bacteremia caused by CA-MRSA. The pathogen carried the type IV-A staphylococcal cassette chromosome mec (SCCmec) without the Panton-Valentine leukocidin (PVL) gene, and was identified as sequence type (ST) 72 by multilocus sequence typing. PMID:24475359

Kim, Suyoung; Lee, Kang Lock; Baek, Hae Lim; Jang, Seung Jun; Moon, Song Mi; Cho, Yong Kyun

2013-12-01

187

Fournier’s gangrene of the penis caused by Streptococcus dysgalactiae subspecies equisimilis: case report and incidence study in a tertiary-care hospital  

PubMed Central

Background Fournier’s gangrene is a rare necrotizing soft tissue infection of the scrotum and penis. We report, to our knowledge, the first case of Fournier’s gangrene caused by Streptococcus dysgalactiae subsp. equisimilis (SDSE), a strain of pyogenic ?-hemolytic streptococci that is increasingly being recognized as an important human pathogen. Case presentation We describe a healthy 59 year-old Caucasian male who presented to the emergency department with Fournier’s gangrene of the penis and scrotum, with extension to the anterior abdominal wall. He underwent urgent surgical debridement of his scrotum, penis, and anterior abdomen. Swabs from the scrotum grew Gram-positive cocci, which were initially identified as Streptococcus anginosus group by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). However, polymerase chain reaction (PCR) amplification and sequencing of the 16S rRNA gene identified the isolate as Streptococcus dysgalatiae subspecies equisimilis (SDSE). The incidences of invasive S. anginosus group and SDSE infections at the London Health Sciences Centre, a tertiary-care institution in southwestern Ontario, were determined between August 1, 2011 and August 31, 2012, revealing a slightly lower rate of SDSE (3.2 cases per 100,000 population) than other studies. Conclusions This case highlights a unique disease manifestation of the emerging human pathogen Streptococcus dysgalatiae subspecies equisimilis that has not been previously reported. This case also underscores the limitations of MALDI-TOF MS in differentiating between closely-related streptococcal species which may have different pathogenic profiles. PMID:23957431

2013-01-01

188

Extragingival pyogenic granuloma histologically mimicking capillary hemangioma  

PubMed Central

Pyogenic granuloma is a tumor-like proliferation to a non-specific infection. The tumor-like growth is considered to be non-neoplastic in nature and presents in various clinical and histological forms in the oral cavity. Hemangiomas are benign vascular anomalies characterized by benign proliferation of blood vessels. The aim of this article is to drive attention toward the uncommon location of capillary hemangioma on the palate. In spite of their benign nature, intraoral capillary hemangiomas are always clinically important to be diagnosed well in time and suitably managed. The lesion in the present case although clinically diagnosed as pyogenic granuloma gave a histological picture of capillary hemangioma when surgically excised. PMID:25425828

Dahiya, Ritu; Kathuria, Abhinav

2014-01-01

189

Characterization and protective immunogenicity of the SzM protein of Streptococcus zooepidemicus NC78 from a clonal outbreak of equine respiratory disease.  

PubMed

Streptococcus zooepidemicus of Lancefield group C is a highly variable tonsillar and mucosal commensal that usually is associated with opportunistic infections of the respiratory tract of vertebrate hosts. More-virulent clones have caused epizootics of severe respiratory disease in dogs and horses. The virulence factors of these strains are poorly understood. The antiphagocytic protein SeM is a major virulence factor and protective antigen of Streptococcus equi, a clonal biovar of an ancestral S. zooepidemicus strain. Although the genome of S. zooepidemicus strain H70, an equine isolate, contains a partial homolog (szm) of sem, expression of the gene has not been documented. We have identified and characterized SzM from an encapsulated S. zooepidemicus strain from an epizootic of equine respiratory disease in New Caledonia. The SzM protein of strain NC78 (SzM(NC78)) has a predicted predominantly alpha-helical fibrillar structure with an LPSTG cell surface anchor motif and resistance to hot acid. A putative binding site for plasminogen is present in the B repeat region, the sequence of which shares homology with repeats of the plasminogen binding proteins of human group C and G streptococci. Equine plasminogen is activated in a dose-dependent manner by recombinant SzM(NC78). Only 23.20 and 25.46% DNA homology is shared with SeM proteins of S. equi strains CF32 and 4047, respectively, and homology ranges from 19.60 to 54.70% for SzM proteins of other S. zooepidemicus strains. As expected, SzM(NC78) reacted with convalescent-phase sera from horses with respiratory disease associated with strains of S. zooepidemicus. SzM(NC78) resembles SeM in binding equine fibrinogen and eliciting strong protective antibody responses in mice. Sera of vaccinated mice opsonized S. zooepidemicus strains NC78 and W60, the SzM protein of which shared partial amino acid homology with SzM(NC78). We conclude that SzM is a protective antigen of NC78; it was strongly reactive with serum antibodies from horses during recovery from S. zooepidemicus-associated respiratory disease. PMID:23740925

Velineni, Sridhar; Timoney, John F

2013-08-01

190

Primary pyogenic abscess of the psoas muscle  

Microsoft Academic Search

Summary. During a six-year period, eleven persons with primary pyogenic abscess of the psoas muscle were treated at the Mackay Memorial\\u000a Hospital. Five were males and six were females and their average age was 47.2 years (range 6?–?83 years). The abscess was\\u000a identified by CT in 7 patients, MRI in 2 and ultrasonography in 1. One abscess was found during

T.-L. Wu; C.-H. Huang; D.-Y. Hwang; J.-H. Lai; R.-Y. Su

1998-01-01

191

Childhood pyogenic meningitis: clinical and investigative indicators of etiology and outcome.  

PubMed Central

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

Johnson, Abdul-Wahab B. R.; Adedoyin, Olanrewaju T.; Abdul-Karim, Aishat A.; Olanrewaju, Abdul-Waheed I.

2007-01-01

192

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

PubMed Central

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

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

193

Distinct structural features of the peroxide response regulator from group A Streptococcus drive DNA binding.  

PubMed

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

Lin, Chang Sheng-Huei; Chao, Shi-Yu; 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

194

Experimental exposure of young pigs using a pathogenic strain of Streptococcus suis serotype 2 and evaluation of this method for disease prevention.  

PubMed Central

Control of Streptococcus suis infections and associated disease have proven to be a difficult challenge under most farm conditions. The objective of this study was to experimentally expose young pigs with a pathogenic strain of S. suis serotype 2 as a means of controlling the disease in a commercial swine farm. Prior to the start of the study, the pathogenic S. suis strain responsible for mortality in the farm was identified and used to experimentally inoculate baby piglets. Over a 3-week period, groups of pigs were selected (100 pigs/wk) and divided into 2 groups: control (50 pigs/week) and experimentally exposed (50 pigs/week). Pigs in the experimentally exposed group were inoculated at 5 d old by tonsillar swabbing with the pathogenic S. suis farm isolate. The effect of exposure with this pathogenic strain was evaluated during the nursery and finishing stages and was based on: morbidity (pigs with central nervous signs (CNS) and/or lameness), mortality and number of treatments required by pigs that had either CNS or lameness. The relative risk (RR) of acquiring disease due to S. suis infection was also calculated. Results showed that morbidity in the experimentally exposed groups was lower than in the control group and these results were statistically different (P = 0.006). Experimentally exposed pigs also showed a statistically significant reduction in lameness problems (P = 0.012), but not in CNS (P = 0.20) or mortality (P = 0.59). Pigs in the control group had an increased RR of 4.76, 8.77 and 2.7 for morbidity, to have lameness or to have CNS signs, respectively. In conclusion, experimental exposure of young pigs with the farm's pathogenic S. suis strain at a young age, had a positive effect in reducing clinical signs characteristics of S. suis infection. This method constitutes a novel approach to the control of S. suis infections in swine farms. Images Figure 1. PMID:10534006

Torremorell, M; Pijoan, C; Dee, S

1999-01-01

195

Pyogenic vertebral osteomyelitis: diagnosis and management.  

PubMed Central

Vertebral osteomyelitis represents a diagnostic challenge to the clinician. Two cases of pyogenic vertebral osteomyelitis occurring weeks to months after a urinary tract infection with Escherichia coli are described. The rarity and subtle clinical presentation of this condition, the presence of pre-existing degenerative arthritic changes, and delayed appearance of radiologic signs of progression to destructive osteomyelitis contributed to a significant delay in diagnosis. Increased awareness of vertebral osteomyelitis as a clinical entity combined with information from radionuclide scanning may permit earlier detection of this condition. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:6367920

Kern, R. Z.; Houpt, J. B.

1984-01-01

196

Quantitative susceptibility of Streptococcus suis strains isolated from diseased pigs in seven European countries to antimicrobial agents licensed in veterinary medicine.  

PubMed

The susceptibility of Streptococcus suis strains (n=384) isolated from diseased pigs in seven European countries to 10 antimicrobial agents was determined. For that purpose a microbroth dilution method was used according to CLSI recommendations. The following antimicrobial agents were tested: ceftiofur, cefquinome, enrofloxacin, florfenicol, gentamicin, penicillin, spectinomycin, tetracycline, tilmicosin and trimethoprim/sulphamethoxazole. Using breakpoints established by CLSI for veterinary pathogens, all strains were susceptible to ceftiofur, florfenicol, enrofloxacin and penicillin. MIC-90 values of these antibiotics were < or = 0.03, 0.5, 2 and < or = 0.13 microg/mL, respectively. A low degree of resistance was observed for gentamicin (1.3%), spectinomycin (3.6%) and trimethoprim/sulphamethoxazole (6.0%). MIC-90 values of these antibiotics were 8, 16 and 2 microg/mL, respectively. A high level of resistance was observed for tetracycline (75.1%). A MIC-90 value of 64 microg/mL was found for this antibiotic. Serotype-associated differences in MIC-90 values were observed for tetracycline, tilmicosin and trimethoprim/suphamethoxazole. PMID:16387456

Wisselink, Henk J; Veldman, Kees T; Van den Eede, Chris; Salmon, Sarah A; Mevius, Dik J

2006-03-10

197

Human Disease Isolates of Serotype M4 and M22 Group A Streptococcus Lack Genes Required for Hyaluronic Acid Capsule Biosynthesis  

PubMed Central

ABSTRACT Group A streptococcus (GAS) causes human pharyngitis and invasive infections and frequently colonizes individuals asymptomatically. Many lines of evidence generated over decades have shown that the hyaluronic acid capsule is a major virulence factor contributing to these infections. While conducting a whole-genome analysis of the in vivo molecular genetic changes that occur in GAS during longitudinal human pharyngeal interaction, we discovered that serotypes M4 and M22 GAS strains lack the hasABC genes necessary for hyaluronic acid capsule biosynthesis. Using targeted PCR, we found that all 491 temporally and geographically diverse disease isolates of these two serotypes studied lack the hasABC genes. Consistent with the lack of capsule synthesis genes, none of the strains produced detectable hyaluronic acid. Despite the lack of a hyaluronic acid capsule, all strains tested multiplied extensively ex vivo in human blood. Thus, counter to the prevailing concept in GAS pathogenesis research, strains of these two serotypes do not require hyaluronic acid to colonize the upper respiratory tract or cause abundant mucosal or invasive human infections. We speculate that serotype M4 and M22 GAS have alternative, compensatory mechanisms that promote virulence. PMID:23131832

Flores, Anthony R.; Jewell, Brittany E.; Fittipaldi, Nahuel; Beres, Stephen B.; Musser, James M.

2012-01-01

198

Full-genome dissection of an epidemic of severe invasive disease caused by a hypervirulent, recently emerged clone of group A Streptococcus.  

PubMed

Group A Streptococcus (GAS) causes an exceptionally broad range of infections in humans, from relatively mild pharyngitis and skin infections to life-threatening necrotizing fasciitis and toxic shock syndrome. An epidemic of severe invasive human infections caused by type emm59 GAS, heretofore an exceedingly rare cause of disease, spread west to east across Canada over a 3-year period (2006 to 2008). By sequencing the genomes of 601 epidemic, historic, and other emm59 organisms, we discovered that a recently emerged, genetically distinct emm59 clone is responsible for the Canadian epidemic. Using near-real-time genome sequencing, we were able to show spread of the Canadian epidemic clone into the United States. The extensive genome data permitted us to identify patterns of geographic dissemination as well as links between emm59 subclonal lineages that cause infections. Mouse and nonhuman primate models of infection demonstrated that the emerged clone is unusually virulent. Transmission of epidemic emm59 strains may have occurred primarily by skin contact, as suggested by an experimental model of skin transmission. In addition, the emm59 strains had a significantly impaired ability to persist in human saliva and to colonize the oropharynx of mice, and seldom caused human pharyngitis. Our study contributes new information to the rapidly emerging field of molecular pathogenomics of bacterial epidemics and illustrates how full-genome data can be used to precisely illuminate the landscape of strain dissemination during a bacterial epidemic. PMID:22330677

Fittipaldi, Nahuel; Beres, Stephen B; Olsen, Randall J; Kapur, Vivek; Shea, Patrick R; Watkins, M Ebru; Cantu, Concepcion C; Laucirica, Daniel R; Jenkins, Leslie; Flores, Anthony R; Lovgren, Marguerite; Ardanuy, Carmen; Liñares, Josefina; Low, Donald E; Tyrrell, Gregory J; Musser, James M

2012-04-01

199

Introduction and Proliferation of Multidrug-Resistant Streptococcus pneumoniae Serotype 19A  

E-print Network

Introduction and Proliferation of Multidrug- Resistant Streptococcus pneumoniae Serotype 19A Clones of disease caused by Streptococcus pneumoniae serotype 19A (Sp19A) and with increasing drug resistance within era, Streptococcus pneumoniae serotype 19A (Sp19A), which became a leading serotype in naso

Dever, Jennifer A.

200

Human Streptococcus agalactiae Isolate in Nile Tilapia (Oreochromis niloticus)  

PubMed Central

Streptococcus agalactiae, the Lancefield group B streptococcus (GBS) long recognized as a mammalian pathogen, is an emerging concern with regard to fish. We show that a GBS serotype Ia multilocus sequence type ST-7 isolate from a clinical case of human neonatal meningitis caused disease and death in Nile tilapia (Oreochromis niloticus). PMID:19402966

Klesius, Phillip H.; Pasnik, David J.; Bohnsack, John F.

2009-01-01

201

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

PubMed

Streptococcus agalactiae, the Lancefield group B streptococcus (GBS) long recognized as a mammalian pathogen, is an emerging concern with regard to fish. We show that a GBS serotype Ia multilocus sequence type ST-7 isolate from a clinical case of human neonatal meningitis caused disease and death in Nile tilapia (Oreochromis niloticus). PMID:19402966

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

2009-05-01

202

Interleukin-1? Regulates CXCL8 Release and Influences Disease Outcome in Response to Streptococcus pneumoniae, Defining Intercellular Cooperation between Pulmonary Epithelial Cells and Macrophages  

PubMed Central

The success of Streptococcus pneumoniae (the pneumococcus) as a pulmonary pathogen is related to its restriction of innate immune responses by respiratory epithelial cells. The mechanisms used to overcome this restriction are incompletely elucidated. Pulmonary chemokine expression involves complex cellular and molecular networks, involving the pulmonary epithelium, but the specific cellular interactions and the cytokines that control them are incompletely defined. We show that serotype 2 or 4 pneumococci induce only modest levels of CXCL8 expression from epithelial cell lines, even in the absence of a polysaccharide capsule. In contrast, coculture of A549 cells with the macrophage-like THP-1 cell line, differentiated with vitamin D, or monocyte-derived macrophages enhanced CXCL8 release. Supernatants from the THP-1 cell line prime A549 cells to release CXCL8 at levels similar to cocultures. Interleukin-1Ra (IL-1Ra) inhibits CXCL8 release from cocultures and reduces the activity of macrophage-conditioned media, but inhibition of tumor necrosis factor alpha (TNF-?) had only a minimal effect on CXCL8 release. Release of IL-1? but not TNF-? was upregulated in cocultures. IL-1 type 1 receptor knockout C57BL/6 and BALB/c mice confirmed the importance of IL-1 signaling in CXC chemokine expression and neutrophil recruitment in vivo. In fulminant disease, increased IL-1 signaling resulted in increased neutrophils in the airway and more invasive disease. These results demonstrate that IL-1 is an important component of the cellular network involving macrophages and epithelial cells, which facilitates CXC chemokine expression and aids neutrophil recruitment during pneumococcal pneumonia. They also highlight a potential clinical role for anti-IL-1 treatment to limit excessive neutrophilic inflammation in the lung. PMID:22158745

Marriott, Helen M.; Gascoyne, Kate A.; Gowda, Ravi; Geary, Ian; Nicklin, Martin J. H.; Iannelli, Francesco; Pozzi, Gianni; Mitchell, Timothy J.; Whyte, Moira K. B.; Sabroe, Ian

2012-01-01

203

Novel Twin Streptolysin S-Like Peptides Encoded in the sag Operon Homologue of Beta-Hemolytic Streptococcus anginosus  

PubMed Central

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

Tabata, Atsushi; Nakano, Kota; Ohkura, Kazuto; Tomoyasu, Toshifumi; Kikuchi, Ken; Whiley, Robert A.

2013-01-01

204

Two cases of giant pyogenic granuloma of scalp  

PubMed Central

Pyogenic granuloma is a benign vascular tumor of unknown etiology, though multiple factors play a role in its onset, e.g., trauma, chronic irritation, drugs etc., It is commonly seen in children and adolescents. Giant pyogenic granuloma is its atypical variant. We are presenting two cases of giant pyogenic granuloma, one, in a 28-year-old adult, presenting as a giant fluffy swelling of scalp and the other in a 11-year-old child, presenting as a giant ulcerated globular swelling of the scalp. PMID:24350008

Chandra, B. Satish; Rao, P. Narasimha

2013-01-01

205

Dietary supplementation with Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus oryzae enhance immunity and disease resistance against Aeromonas hydrophila and Streptococcus iniae infection in juvenile tilapia Oreochromis niloticus.  

PubMed

A feeding trial was conducted to investigate the effects of dietary administration of probiotic with Bacillus subtilis, Aspergillus oryzae and Saccharomyces cerevisiae on growth, innate immune response, Hemato-immunological parameters and disease resistance of Nile tilapia, Oreochromis niloticus. Animals were distributed in three equal groups, each of five replicates and received one of the following experimental diets for four weeks: Control, non-supplemented diet; 5 g kg(-1) probiotic mixture (B. subtilis 1.5 × 10(9) CFU g(-1), S. cerevisiae 10(9) CFU g(-1) and A. oryzae 2 × 10(9) CFU g(-1)); and 10 g kg(-1) probiotic mixture (B. subtilis 3.0 × 10(9) CFU g(-1), S. cerevisiae 2.0 × 10(9) CFU g(-1) and A. oryzae 4.0 × 10(9) CFU g(-1)). The respiratory burst activity, white blood cells and hematological parameters were evaluated after four, five and six weeks of feeding. At the end of the growth trial, fish were sampled for intestinal microbiology and challenged by intraperitoneal injection of LD50 concentration of Aeromonas hydrophila and Streptococcus iniae. Mortality was recorded for the following 3 weeks. Results showed that administration of the probiotic had no significant effect on the growth rates of Nile tilapias, although the fish fed probiotics had better feed conversion. Respiratory burst activity, erythrocyte fragility and levels of white blood cells were significantly improved in tilapias fed diet supplemented with probiotic levels (P < 0.05), which may exhibit up-regulating effects on tilapia immune parameters. The cumulative mortality after A. hydrophila and S. iniae challenge decreased in tilapias fed with probiotic (P < 0.05). The present study demonstrated the potential of B. subtilis, S. cerevisiae and A. oryzae combined as beneficial dietary probiotic in juvenile O. niloticus. PMID:25530581

Iwashita, Marina Keiko P; Nakandakare, Ivan B; Terhune, Jeffery S; Wood, Theresa; Ranzani-Paiva, Maria José T

2015-03-01

206

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

PubMed Central

"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

Ruoff, K L

1988-01-01

207

Pyogenic Granuloma on the Upper Labial Mucosa: A Case Report  

PubMed Central

Pyogenic granuloma is thought to represent an exuberant tissue response to a local irritation or trauma. It is a reactional response to constant minor trauma and it might be related to hormonal changes. Clinically, these lesions usually present as single nodules or sessile papules with smooth or lobulated surfaces. These may be seen in any size, from a few millimetres to several centimetres. Pyogenic granuloma of the oral cavity is known to involve the gingiva more commonly (75% of all the cases). An extragingival occurrence of pyogenic granuloma is rare. This paper has described an extragingival pyogenic granuloma which occurred on the upper labial mucosa in a 30 years old female patient. PMID:23905151

K A, Kamala; Ashok, L.; G P, Sujatha

2013-01-01

208

Studies of the two-component signal transduction system RR/HK06 in Streptococcus pneumoniae.  

E-print Network

??Streptococcus pneumoniae (the pneumococcus) is a major human pathogen responsible for significant morbidity and mortality worldwide. Pneumococcal disease, which can include both invasive conditions such… (more)

Standish, Alistair James

2006-01-01

209

Brachial Plexus Neuritis Associated With Streptococcus agalactiae Infection: A Case Report  

PubMed Central

Brachial plexus neuritis is reportedly caused by various factors; however, it has not been described in association with Streptococcus agalactiae. This is a case report of a patient diagnosed with brachial plexus neuritis associated with pyogenic arthritis of the shoulder. A 57-year-old man visited the hospital complaining of sudden weakness and painful swelling of the left arm. The diagnosis was pyogenic arthritis of the left shoulder, and the patient was treated with open irrigation and debridement accompanied by intravenous antibiotic therapy. S. agalactiae was isolated from a wound culture, and an electrodiagnostic study showed brachial plexopathy involving the left upper and middle trunk. Nine weeks after onset, muscle strength improved in most of the affected muscles, and an electrodiagnostic study showed signs of reinnervation. In conclusion, S. agalactiae infection can lead to various complications including brachial plexus neuritis. PMID:25229037

Seo, Yu Jung; Lee, Yu Jin; Kim, Joon Sung; Lim, Seong Hoon

2014-01-01

210

Evidence for niche adaptation in the genome of the bovine pathogen Streptococcus uberis  

PubMed Central

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

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

211

Antiphagocytic function of an IgG glycosyl hydrolase from Streptococcus equi subsp. equi and its use as a vaccine component.  

PubMed

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

Flock, Margareta; Frykberg, Lars; Sköld, Markus; Guss, Bengt; Flock, Jan-Ingmar

2012-08-01

212

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

PubMed Central

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

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

2012-01-01

213

An Unusual Cause of Flexor Tenosynovitis: Streptococcus mitis  

PubMed Central

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

Ulucay, Ca?atay; Ozler, Turhan

2014-01-01

214

Beta-hemolytic streptococcus group A endocarditis: a rare clinical presentation.  

PubMed

A case report of an elderly gentleman is reported herein, who presented with one week history of fever, drowsiness and left lower limb weakness. Examination revealed left lower limb weakness with power of grade 3/5. His workup showed evidence of infection and multiple cerebral infarcts on the right side. Blood culture grew Streptococcus pyogens. Echocardiogram showed two vegetations on the aortic valve. Fever was the main presenting feature in this case but it was the presentation of patient with multiple cerebral infarcts that lead to the diagnosis of infective endocarditis. The organism causing Infective Endocarditis (IE) in this patient was a rare one. PMID:18452666

Almas, Aysha; Tariq, Muhammad

2008-01-01

215

Streptococcus pyogenes streptolysin O as a cause of false-positive CAMP reactions.  

PubMed Central

The synergistic hemolysis of sheep erythrocytes in the CAMP reaction by the sequential action of staphylococcal beta-lysin and the CAMP factor of group B streptococci is the only known function of this extracellular product of group B streptococci. The reaction forms the basis of the CAMP test used to identify group B streptococci because the CAMP factor is believed to be restricted to this group of organisms. However, on occasion other streptococci, notably group A streptococci, may produce a similar synergistic lysis of sheep erythrocytes. The nature of the synergistic lytic factor of group A streptococci responsible for this sequential hemolysis was investigated in a tube CAMP reaction system. The properties of this synergistic lytic factor were found to correspond to those of streptolysin O of group A streptococci. The synergistic lytic factor, like streptolysin O, was produced during the logarithmic phase of growth; the activity was increased by reducing agents and greatly decreased or abolished by heat, trypsin, cholesterol, and anti-streptolysin O, and it was immunogenic in rabbits. This would suggest that the synergistic hemolysis seen in the CAMP reaction system with group A streptococci is due to the action of those small amounts of streptolysin O which remain unoxidized and thus have a capacity to lyse the fragile beta-lysin-treated sheep erythrocytes. PMID:6371051

Tapsall, J W; Phillips, E A

1984-01-01

216

Linkage relationships of mutations endowing Streptococcus pyogenes with resistance to antibiotics that affect the ribosome  

Microsoft Academic Search

Several mutations conferring resistance to streptomycin, kanamycin, spectinomycin, erythromycin, and lincomycin on the group A streptococcal strain 56188 have been mapped by two- and three-point crosses using transduction with bacteriophage A25. The markers are located in two linkage regions too distant to be cotransduced. One harbors the streptomycin and kanamycin loci which are transduced jointly at 78% and the other

Horst Malke

1972-01-01

217

Berberine sulfate blocks adherence of Streptococcus pyogenes to epithelial cells, fibronectin, and hexadecane.  

PubMed Central

Berberine sulfate is an alkaloid extracted from the roots and bark of various plants and possesses antibacterial, antifungal, and antiprotozoal activities. Most studies have focused on the bacteriostatic or bactericidal activities of this compound. In this study, we report that berberine sulfate is bacteriostatic for streptococci and that sub-MICs of berberine blocked the adherence of streptococci to host cells, immobilized fibronectin, and hexadecane. Concentrations of berberine below its MIC caused an eightfold increase in release of lipoteichoic acid from the streptococci. Higher concentrations of berberine directly interfered with the adherence of streptococci to host cells either by preventing the complexing of lipoteichoic acid with fibronectin or by dissolution of such complexes once they were formed. Thus, berberine sulfate interferes with the adherence of group A streptococci by two distinct mechanisms: one by releasing the adhesin lipoteichoic acid from the streptococcal cell surface and another by directly preventing or dissolving lipoteichoic acid-fibronectin complexes. PMID:3058020

Sun, D; Courtney, H S; Beachey, E H

1988-01-01

218

Scarlet fever  

MedlinePLUS

... disease caused by infection with the group A Streptococcus bacteria (the same bacteria that causes strep throat ). ... Bisno AL, Stevens DL. Streptococcus pyogenes. In: Mandell GL, Bennett ... of Infectious Diseases . 7th ed. Philadelphia, Pa: Elsevier ...

219

Streptococcus Adherence and Colonization  

PubMed Central

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

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

2009-01-01

220

Group B Streptococcus and Pregnancy  

MedlinePLUS

What is group B streptococcus (GBS)? Group B streptococcus is one of the many types of bacteria that live in the body and usually do ... and Gynecologists f AQ • What is group B streptococcus (GBS)? • What does it mean to be colonized ...

221

Streptococcus bovis meningitis and hemorrhoids.  

PubMed

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

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

2010-07-01

222

Nucleotide Sequence Analysis of Integrative Conjugative Element Tn5253 of Streptococcus pneumoniae  

PubMed Central

Conjugative transposon Tn5253, an integrative conjugative element (ICE) of Streptococcus pneumoniae carrying the cat and tet(M) genes, was shown to be 64,528 bp in size and to contain 79 open reading frames, of which only 38 could be annotated. Two distinct genetic elements were found integrated into Tn5253: Tn5251 (18,033 bp), of the Tn916-Tn1545 family of ICEs, and ?cat(pC194) (7,627 bp), which could not conjugate but was capable of intracellular mobility by excision, circularization, and integration by homologous recombination. The highest conjugation frequency of Tn5253 was observed when Streptococcus pyogenes was the donor (6.7 × 10?3 transconjugants/donor). PMID:24295984

Iannelli, Francesco; Santoro, Francesco; Oggioni, Marco R.

2014-01-01

223

Midline pyogenic granuloma of the tongue: two case studies.  

PubMed

Characteristically, pyogenic granuloma of the tongue is more common on the lateral side of the tongue. The reasons for this are unclear, but may be related to trauma from adjacent teeth or dentures. This article was prompted by the presentation of two patients with lesions in the midline of the anterior surface of the dorsum of the tongue. Both lesions were successfully removed surgically, and histology revealed them to be pyogenic granulomas. There has been no evidence of recurrence in the 6th month of the follow-up period. PMID:12761638

Croton, Elizabeth; Kale, Uday

2003-11-01

224

Midline pyogenic granuloma of the tongue: two case studies  

Microsoft Academic Search

Characteristically, pyogenic granuloma of the tongue is more common on the lateral side of the tongue. The reasons for this are unclear, but may be related to trauma from adjacent teeth or dentures. This article was prompted by the presentation of two patients with lesions in the midline of the anterior surface of the dorsum of the tongue. Both lesions

Elizabeth Croton; Uday Kale

2003-01-01

225

Phylogenomics and the Dynamic Genome Evolution of the Genus Streptococcus  

PubMed Central

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

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

226

Are Pyogenic Liver Abscesses Still a Surgical Concern? A Western Experience  

PubMed Central

Backgrounds. Pyogenic liver abscess is a rare disease whose management has shifted toward greater use of percutaneous drainage. Surgery still plays a role in treatment, but its indications are not clear. Method. We conducted a retrospective study of pyogenic abscess cases admitted to our university hospital between 1999 and 2010 and assessed the factors potentially associated with surgical treatment versus medical treatment alone. Results. In total, 103 liver abscess patients were treated at our center. The mortality was 9%. The main symptoms were fever and abdominal pain. All of the patients had CRP > 6?g/dL. Sixty-nine patients had a unique abscess. Seventeen patients were treated with antibiotics alone and 57 with percutaneous drainage and antibiotics. Twenty-seven patients who were treated with percutaneous techniques required surgery, and 29 patients initially received it. Eventually, 43 patients underwent abscess surgery. The factors associated with failed medical treatment were gas-forming abscess (P = 0.006) and septic shock at the initial presentation (P = 0.008). Conclusion. Medical and percutaneous treatment constitute the standard management of liver abscess cases. Surgery remains necessary after failure of the initial treatment but should also be considered as an early intervention for cases presenting with gas-forming abscesses and septic shock and when treatment of the underlying cause is immediately required. PMID:22536008

Alkofer, Barbara; Dufay, Corentin; Parienti, Jean Jacques; Lepennec, Vincent; Dargere, Sylvie; Chiche, Laurence

2012-01-01

227

Resistance in Streptococcus pneumoniae  

Microsoft Academic Search

\\u000a Streptococcus pneumoniae is a leading cause of community-acquired lower respiratory tract infections, sinusitis, meningitis, and bloodstream infections.\\u000a Pneumococci are Gram positive, encapsulated bacteria and exhibit more than 90 different capsular serotypes.\\u000a \\u000a Resistance to penicillin in clinical isolates was reported anecdotally as early as 1965, but was not considered a major concern\\u000a until the mid-1990s. In the 1990s, there was a

Mathias W. R. Pletz; Tobias Welte; Lesley McGee

228

Streptococcus bovis Meningitis in an Infant  

PubMed Central

Streptococcus bovis is a nonenterococcal, group D streptococcus which has been identified as a causative agent for serious human infections, including endocarditis, bacteremia, and septic arthritis. Several cases of adult S. bovis meningitis have been reported, usually in association with underlying disease. In the neonatal period, it is an uncommon agent of meningitis. We report, to our knowledge, the third documented case of neonatal S. bovis meningitis in the English language literature. As in the previous cases, this neonate showed no anatomical or congenital immunologic lesion which might be expected to predispose the patient to meningitis. Sequencing of the 16S ribosomal DNA gene was performed and a new PCR test was used to secure a more reliable identification of the strain. PMID:10618145

Grant, Russell J.; Whitehead, Terence R.; Orr, James E.

2000-01-01

229

Intravascular laser therapy in different forms of lung diseases  

NASA Astrophysics Data System (ADS)

The potentions of laser intravascular therapy in elimination of pyogenic and inflammatory intoxication in cases of acute pneumonia, pyo-destructive diseases (including posttraumatic diseases) of the lungs are studied clinically.

Kirillov, M. N.; Reshetnikov, V. A.; Kazhekin, O. A.; Shepelenko, A. F.

1993-06-01

230

Clinicopathologic characterization of oral pyogenic granuloma in 8 cats.  

PubMed

This case series characterizes the clinicopathologic features and treatment of oral pyogenic granuloma in 8 cats. The cats reported here were patients originating from collaborative efforts at an academic clinical teaching hospital and a specialty dentistry/oral surgery referral practice. Although the initial biopsy results were variable, in all cases the diagnosis reflected an inflammatory process. A second clinicopathologic evaluation of these cases determined that all lesions were consistent with oral pyogenic granuloma. The location of the lesion was consistent among all cats within the present study Lesions developed at the vestibular mucogingival tissues of the mandibular first molar teeth. We propose that malocclusion and secondary traumatic contact of the ipsilateral maxillary fourth premolar tooth with the mandibular soft tissues is a possible contributing factor in the etiopathogenic mechanism. PMID:25185331

Riehl, Jessica; Bell, Cynthia M; Constantaras, Marika E; Snyder, Christopher J; Charlier, Cindy J; Soukup, Jason W

2014-01-01

231

Hepatogastric fistula: a rare complication of pyogenic liver abscess.  

PubMed

Hepatogastric fistula is very rare. We report a case of hepatogastric fistula as a complication of pyogenic liver abscess. A 40-year-old man presented with upper abdominal pain and high-grade fever of 2?weeks. Evaluation revealed multiple liver abscesses. On an empirical diagnosis of pyogenic liver abscess, he was treated with antibiotics. During hospital stay he developed intermittent large quantity bilious vomiting. Gastroduodenoscopy and contrast-enhanced CT of the abdomen showed rupture of left lobe liver abscess into the stomach. As expectant management failed to resolve the abscess, endoscopic retrograde papillotomy and stenting of common bile duct was performed. After endoscopic stenting, symptoms subsided. Imaging repeated after 2 weeks of endoscopic stenting showed resolving abscess. He was discharged and is doing well on regular follow-ups. We conclude that hepatogastric fistula can be managed by endoscopic stenting as bile flow through the stent hastens resolution and healing of the fistula. PMID:25035445

Gandham, Venkata Srinivas; Pottakkat, Biju; Panicker, Lakshmi C; Hari, Ranjit Vijaya

2014-01-01

232

Screening of Streptococcus pneumoniae ABC Transporter Mutants Demonstrates that LivJHMGF, a Branched-Chain Amino Acid ABC Transporter, Is Necessary for Disease Pathogenesis?  

PubMed Central

Bacterial ABC transporters are an important class of transmembrane transporters that have a wide variety of substrates and are important for the virulence of several bacterial pathogens, including Streptococcus pneumoniae. However, many S. pneumoniae ABC transporters have yet to be investigated for their role in virulence. Using insertional duplication mutagenesis mutants, we investigated the effects on virulence and in vitro growth of disruption of 9 S. pneumoniae ABC transporters. Several were partially attenuated in virulence compared to the wild-type parental strain in mouse models of infection. For one ABC transporter, required for full virulence and termed LivJHMGF due to its similarity to branched-chain amino acid (BCAA) transporters, a deletion mutant (?livHMGF) was constructed to investigate its phenotype in more detail. When tested by competitive infection, the ?livHMGF strain had reduced virulence in models of both pneumonia and septicemia but was fully virulent when tested using noncompetitive experiments. The ?livHMGF strain had no detectable growth defect in defined or complete laboratory media. Recombinant LivJ, the substrate binding component of the LivJHMGF, was shown by both radioactive binding experiments and tryptophan fluorescence spectroscopy to specifically bind to leucine, isoleucine, and valine, confirming that the LivJHMGF substrates are BCAAs. These data demonstrate a previously unsuspected role for BCAA transport during infection for S. pneumoniae and provide more evidence that functioning ABC transporters are required for the full virulence of bacterial pathogens. PMID:19470745

Basavanna, Shilpa; Khandavilli, Suneeta; Yuste, Jose; Cohen, Jonathan M.; Hosie, Arthur H. F.; Webb, Alexander J.; Thomas, Gavin H.; Brown, Jeremy S.

2009-01-01

233

Dominance of Multidrug-Resistant Denmark(14)-32 (ST230) Clone Among Streptococcus pneumoniae Serotype 19A Isolates Causing Pneumococcal Disease in Bulgaria from 1992 to 2013.  

PubMed

A pneumococcal conjugate vaccine (PCV10) was introduced in Bulgarian national immunization program since April 2010. Clonal composition based on pulsed-field gel electrophoresis and multilocus sequence typing genotyping of 52 serotype 19A Streptococcus pneumoniae isolates was analyzed. These were invasive and respiratory isolates collected between 1992 and 2013 from both children (78.8% <5 years) and adults with pneumococcal infections. Multidrug resistance was found in 82.7% of all 19A isolates. The most prevalent genotype (63.5%) among serotype 19A pneumococcal strains was the multidrug-resistant clonal complex CC230, which is a capsular switched variant of the Denmark(14)-32 (ST230) global clone. The most frequent sequence type (ST) was ST230 (48.1%) and together with four other closely related STs (15.4%), belonging to ST1611, ST276, ST7466, and ST2013, which were single- and double-locus variants; they were included in the main CC230. The disappearance of highly drug-resistant ST663 clone and emergence of new clones as CC320 and CC199 was also observed among the rest 19A isolates. A comparison of clonal composition between invasive and noninvasive isolates did not show a great genetic diversity among both kinds of isolates. Continuous surveillance of serotype 19A population following the introduction of PCV10 is essential to evaluate the impact of the vaccine on the epidemiology of this serotype. PMID:25080213

Setchanova, Lena Petrova; Alexandrova, Alexandra; Dacheva, Daniela; Mitov, Ivan; Kaneva, Radka; Mitev, Vanio

2015-02-01

234

21 CFR 866.3740 - Streptococcus spp. serological reagents.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Streptococcus spp. serological reagents. 866...Serological Reagents § 866.3740 Streptococcus spp. serological reagents. (a) Identification. Streptococcus spp. serological...

2013-04-01

235

21 CFR 866.3740 - Streptococcus spp. serological reagents.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Streptococcus spp. serological reagents. 866...Serological Reagents § 866.3740 Streptococcus spp. serological reagents. (a) Identification. Streptococcus spp. serological...

2010-04-01

236

21 CFR 866.3740 - Streptococcus spp. serological reagents.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Streptococcus spp. serological reagents. 866...Serological Reagents § 866.3740 Streptococcus spp. serological reagents. (a) Identification. Streptococcus spp. serological...

2014-04-01

237

21 CFR 866.3740 - Streptococcus spp. serological reagents.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Streptococcus spp. serological reagents. 866...Serological Reagents § 866.3740 Streptococcus spp. serological reagents. (a) Identification. Streptococcus spp. serological...

2011-04-01

238

21 CFR 866.3740 - Streptococcus spp. serological reagents.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Streptococcus spp. serological reagents. 866...Serological Reagents § 866.3740 Streptococcus spp. serological reagents. (a) Identification. Streptococcus spp. serological...

2012-04-01

239

Streptolysin S of Streptococcus anginosus exhibits broad-range hemolytic activity.  

PubMed

Streptococcus anginosus is a commensal of mucous membranes and an emerging human pathogen. Some strains, including the type strain, display a prominent ?-hemolytic phenotype. A gene cluster (sag), encoding a variant of streptolysin S (SLS) has recently been identified as the genetic background for ?-hemolysin production in S. anginosus. In this study, we further characterized the hemolytic and cytolytic activity of the S. anginosus hemolysin in comparison with other streptococcal hemolysins. The results indicate that SLS of S. anginosus is a broad-range hemolysin able to lyse erythrocytes of different species, including horse, bovine, rabbit and even chicken. The hemolytic activity is temperature dependent, and a down-regulation of the hemolysin expression is induced in the presence of high glucose levels. Survival assays indicate that in contrast to other streptococcal species, S. anginosus does not require SLS for survival in the presence of human granulocytes. Cross-complementation studies using the sagB and sagD genes of Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis demonstrated functional similarities to the S. anginosus SLS. Nevertheless, distinct differences to other streptolysin S variants were noted and provide further insights into the molecular mechanisms of SLS pathogen host interactions. PMID:25381594

Asam, Daniela; Mauerer, Stefanie; Spellerberg, Barbara

2014-11-01

240

AN OVERVIEW STREPTOCOCCUS IN WARM-WATER FISH  

Technology Transfer Automated Retrieval System (TEKTRAN)

Despite being known mainly as mammalian disease agents, Streptococcus iniae and S. agalactiae have become recognized as emerging pathogens of wild and cultured fish. The worldwide economic impact of S. iniae and S. agalactiae to the aquaculture industry is estimated in hundreds of millions annually...

241

An unusual presentation of pyogenic granuloma of the lower lip  

PubMed Central

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. PMID:25395771

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

2014-01-01

242

Plants used in Guatemala for the treatment of respiratory diseases. 1. Screening of 68 plants against gram-positive bacteria.  

PubMed

Respiratory ailments are important causes of morbidity and mortality in developing countries. Ethnobotanical surveys and literature reviews conducted in Guatemala during 1986-88 showed that 234 plants from 75 families, most of them of American origin, have been used for the treatment of respiratory ailments. Three Gram-positive bacteria causing respiratory infections (Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus pyogenes) were used to screen 68 of the most commonly used plants for activity. Twenty-eight of these (41.2%) inhibited the growth of one or more of the bacteria tested. Staphylococcus aureus was inhibited by 18 of the plant extracts, while 7 extracts were effective against Streptococcus pyogenes. Plants of American origin which exhibited antibacterial activity were: Gnaphalium viscosum, Lippia alba, Lippia dulcis, Physalis philadelphica, Satureja brownei, Solanum nigrescens and Tagetes lucida. These preliminary in vitro results provide scientific basis for the use of these plants against bacterial respiratory infections. PMID:2023428

Caceres, A; Alvarez, A V; Ovando, A E; Samayoa, B E

1991-02-01

243

MI68CH23-Nizet ARI 9 June 2014 16:33 Subterfuge and Sabotage  

E-print Network

-micro-092412-155711 Copyright c 2014 by Annual Reviews. All rights reserved Keywords Streptococcus pyogenes, Streptococcus agalactiae, Staphylococcus aureus, Streptococcus pneumoniae, innate immunity, immune evasion of the genera Streptococcus and Staphylococcus stand out for their unique invasive disease po- tential

Nizet, Victor

244

Use of Streptococcus salivarius K12 in the prevention of streptococcal and viral pharyngotonsillitis in children  

PubMed Central

Background Streptococcus salivarius K12 is an oral probiotic strain releasing two lantibiotics (salivaricin A2 and salivaricin B) that antagonize the growth of S. pyogenes, the most important bacterial cause of pharyngeal infections in humans also affected by episodes of acute otitis media. S. salivarius K12 successfully colonizes the oral cavity, and is endowed with an excellent safety profile. We tested its preventive role in reducing the incidence of both streptococcal and viral pharyngitis and/or tonsillitis in children. Materials and methods We enrolled 61 children with a diagnosis of recurrent oral streptococcal disorders. Thirty-one of them were enrolled to be treated daily for 90 days with a slow-release tablet for oral use, containing no less than 1 billion colony-forming units/tablet of S. salivarius K12 (Bactoblis®), and the remaining 30 served as the untreated control group. During treatment, they were all examined for streptococcal infection. Twenty children (ten per group) were also assessed in terms of viral infection. Secondary end points in both groups were the number of days under antibiotic and antipyretic therapy and the number of days off school (children) and off work (parents). Results The 30 children who completed the 90-day trial with Bactoblis® showed a significant reduction in their episodes of streptococcal pharyngeal infection (>90%), as calculated by comparing the infection rates of the previous year. No difference was observed in the control group. The treated group showed a significant decrease in the incidence (80%) of oral viral infections. Again, there was no difference in the control group. With regard to secondary end points, the number of days under antibiotic treatment of the treated and control groups were 30 and 900 respectively, days under antipyretic treatment 16 and 228, days of absence from school 16 and 228, and days of absence from work 16 and 228. The product was well tolerated by the subjects, with no side effects, and only one individual reported bad product palatability and dropped out. Conclusion Prophylactic administration of S. salivarius K12 to children with a history of recurrent oral streptococcal disease resulted in a considerable reduction of episodes of both streptococcal and viral infections and reduced the number of days under antibiotic and/or antipyretic therapy and days of absence from school or work. PMID:24600248

Di Pierro, Francesco; Colombo, Maria; Zanvit, Alberto; Risso, Paolo; Rottoli, Amilcare S

2014-01-01

245

Resolution of recalcitrant pyogenic granuloma with laser, corticosteroid, and timolol therapy.  

PubMed

A pyogenic granuloma (PG) is a rapidly growing benign vascular tumor that can be found on the skin or subcutaneous tissue. While some pyogenic granulomas may resolve spontaneously, most have a tendency to bleed easily and require treatment. Current therapeutic modalities include topical imiquimod, cryotherapy, electrodessication, curettage, excision, laser therapy, sclerotherapy, and microembolization. We report a recalcitrant case of chronic pyogenic granuloma occurring on the scalp of a healthy young male which was unresponsive to conventional surgical and non-surgical modalities. Ultimately, aggressive laser therapy, intralesional triamcinolone acetonide injections, and topical timolol application led to complete resolution and healing. PMID:24656264

Millsop, Jillian Wong; Trinh, Nhat; Winterfield, Laura; Berrios, Ricado; Hutchens, Kelli A; Tung, Rebecca

2014-03-01

246

Multiplex PCR for Identification of Seven Streptococcus pneumoniae Serotypes Targeted by a 7Valent Conjugate Vaccine  

Microsoft Academic Search

Pneumococcal disease is a major public health problem throughout the world. At least 1 million children die of pneu- mococcal disease every year, most of these being young chil- dren in developing countries (15). In the developed world, elderly persons carry the major disease burden. The etiological agent, Streptococcus pneumoniae (the pneumococcus), is sur- rounded by a polysaccharide capsule. Differences

Damien M. O'Halloran; Mary T. Cafferkey

2005-01-01

247

Laser: A Powerful Tool for Treatment of Pyogenic Granuloma  

PubMed Central

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

Rai, Shalu; Kaur, Mandeep; Bhatnagar, Puneet

2011-01-01

248

Multilocus Sequence Analysis of Streptococcus canis Confirms the Zoonotic Origin of Human Infections and Reveals Genetic Exchange with Streptococcus dysgalactiae subsp. equisimilis  

PubMed Central

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

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

2013-01-01

249

Intramolecular isopeptide but not internal thioester bonds confer proteolytic and significant thermal stability to the S. pyogenes pilus adhesin Spy0125  

PubMed Central

Streptococcus pyogenes and other Gram-positive bacterial pathogens present long macromolecular filaments known as pili on their surface that mediate adhesion and colonization. These pili are covalent polymers, assembled by sortases. Typically, they comprise a putative adhesin at their tip, a backbone subunit present in multiple copies and a basal subunit that is covalently anchored to the peptidoglycan layer of the cell surface. The crystal structures of pilin subunits revealed the presence of unusual covalent linkages in these proteins, including intramolecular isopeptide and internal thioester bonds. The intramolecular isopeptide bonds in backbone pilins are important for protein stability. Here, using both the wild-type protein and a set of mutants, we assessed the proteolytic and thermal stability of the S. pyogenes pilus tip adhesin Spy0125, in the presence and absence of its intramolecular isopeptide and internal thioester bonds. We also determined a crystal structure of the internal thioester bond variant Spy0125Cys426Ala. We find that mutations in the intramolecular isopeptide bonds compromise the stability of Spy0125. Using limited proteolysis and thermal denaturation assays, we could separate the contribution of each intramolecular isopeptide bond to Spy0125 stability. In contrast, mutation in the internal thioester bond had a lesser effect on protein stability and the crystal structure is essentially identical to wild type. This work suggests that the internal thioester in Spy0125, although having a minor contributory role, is not required for protein stability and must have a different primary function, most likely mediating a covalent interaction with host cell ligands. Proteins 2014; 82:517–527. © 2013 The Authors Proteins: Structure, Function, and Bioinformatics Published by Wiley Periodicals, Inc. PMID:24123467

Walden, Miriam; Crow, Allister; Nelson, Miles D; Banfield, Mark J

2014-01-01

250

Single-level lumbar pyogenic spondylodiscitis treated with minimally invasive anterior debridement and fusion combined with posterior fixation via Wiltse approach.  

PubMed

The effect and safety of anterior debridement and fusion with a minimally invasive approach combined with posterior fixation via the Wiltse approach were assessed in the single-level lumbar pyogenic spondylodiscitis. Seventeen patients from 2007 to 2009 underwent anterior debridement and fusion with a minimally invasive approach combined with posterior fixation via the Wiltse approach. Postoperative follow-up time was 24-41 months. Data included the patients' general information, microbiology, operative time, intraoperative blood loss, postoperative complications, intervertebral fusion rate, and preoperative and final follow-up scores for American Spinal Injury Association (ASIA) impairment, visual analogue scale (VAS), and Oswestry Disability Index (ODI). Ten patients had undergone a prior spinal invasive procedure, and 7 had hematogenous infection. The infected segments included L1-2, L2-3, L3-4, and L4-5 in 1, 2, 5, and 9 cases, respectively. Thirteen bacterial cultures were positive for Staphylococcus aureus (5 cases), Staphylococcus epidermidis (4), Streptococcus (3), and Escherichia coli (1). The operative time was 213.8±45.6 min, and the intraoperative blood loss was 180.6±88.1 mL. Postoperative complications consisted of urinary retention (2 cases), constipation (3), and deep vein thrombosis (2). On the final follow-up, VAS scores and ODIs were significantly lower than those of preoperation, while the ASIA grades improved. All the cases achieved good intervertebral bony fusion. Anterior debridement and fusion with a minimally invasive approach combined with posterior fixation via the Wiltse approach can successfully treat single-level lumbar pyogenic spondylodiscitis, with less trauma and reliable immobilization. It is a viable option for clinical application. PMID:24142724

Lin, Yang; Chen, Wen-jian; Zhu, Wen-tao; Li, Feng; Fang, Huang; Chen, An-min; Xiong, Wei

2013-10-01

251

Streptococcus agalactiae infection in domestic rabbits, Oryctolagus cuniculus.  

PubMed

Streptococcus agalactiae (Group B streptococcus, GBS) has emerged as an important pathogen that affects humans and animals, including aquatic species. In August 2011, a severe infectious disease affecting rabbits, which caused 42% mortality, occurred in Mianyang, Sichuan Province, China. The main clinical signs included acute respiratory distress syndrome, fever, paddling and convulsions. A Gram-positive, chain-forming coccus was isolated from the primary organs and tissues of diseased rabbits and then identified as S. agalactiae by morphology, biochemical and physiological characteristics, 16S rDNA and gyrB gene sequences analysis. All isolates of S. agalactiae showed a similar antibiotic susceptibility, which were sensitive to florfenicol, ampicillin,gentamicin and norfloxacin, as well as being resistant to penicillin, amoxicillin and tetracycline. To our knowledge, this is the first report on S. agalactiae natural infection in domestic rabbits. PMID:23465082

Ren, S Y; Geng, Y; Wang, K Y; Zhou, Z Y; Liu, X X; He, M; Peng, X; Wu, C Y; Lai, W M

2014-12-01

252

Recombination-deficient Streptococcus sanguis  

SciTech Connect

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.

Daneo-Moore, L.; Volpe, A.

1985-05-01

253

Comparative genomics of the bacterial genus streptococcus illuminates evolutionary implications of species groups.  

PubMed

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

Gao, Xiao-Yang; Zhi, Xiao-Yang; Li, Hong-Wei; Klenk, Hans-Peter; Li, Wen-Jun

2014-01-01

254

Macedocin, a Food-Grade Lantibiotic Produced by Streptococcus macedonicus ACA-DC 198  

PubMed Central

Streptococcus macedonicus ACA-DC 198, a strain isolated from Greek Kasseri cheese, produces a food-grade lantibiotic named macedocin. Macedocin has a molecular mass of 2,794.76 ± 0.42 Da, as determined by electrospray mass spectrometry. Partial N-terminal sequence analysis revealed 22 amino acid residues that correspond with the amino acid sequence of the lantibiotics SA-FF22 and SA-M49, both of which were isolated from the pathogen Streptococcus pyogenes. Macedocin inhibits a broad spectrum of lactic acid bacteria, as well as several food spoilage and pathogenic bacteria, including Clostridium tyrobutyricum. It displays a bactericidal effect towards the most sensitive indicator strain, Lactobacillus sakei subsp. sakei LMG 13558T, while the producer strain itself displays autoinhibition when it is grown under conditions that do not favor bacteriocin production. Macedocin is active at pHs between 4.0 and 9.0, and it retains activity even after incubation for 20 min at 121°C with 1 atm of overpressure. Inhibition of macedocin by proteolytic enzymes is variable. PMID:12450808

Georgalaki, Marina D.; Van den Berghe, Erika; Kritikos, Dimitrios; Devreese, Bart; Van Beeumen, Jozef; Kalantzopoulos, George; De Vuyst, Luc; Tsakalidou, Effie

2002-01-01

255

Conjugative Transfer of the Integrative Conjugative Elements ICESt1 and ICESt3 from Streptococcus thermophilus? †  

PubMed Central

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

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

2009-01-01

256

Coenzyme preference of Streptococcus pyogenes ?1-pyrroline-5-carboxylate reductase: evidence supporting NADPH as the physiological electron donor.  

PubMed

The streptococcal enzyme that catalyzes the last step in proline biosynthesis was heterologously expressed and the recombinant protein was purified to electrophoretic homogeneity and characterized thoroughly. As for ?1-pyrroline-5-carboxylate reductases from other sources, it was able to use either NADH or NADPH as the electron donor in vitro. However, with NADH the activity was markedly inhibited by physiological levels of NADP+. Results also strengthen the possibility that an unusual ordered substrate binding occurs, in which the dinucleotide binds last. PMID:21938400

Petrollino, Davide; Forlani, Giuseppe

2012-07-01

257

Bacteriophage enzymes for the prevention and treatment of bacterial infections: Stability and stabilization of the enzyme lysing Streptococcus pyogenes cells  

SciTech Connect

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

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

258

Release of SpeA from Streptococcus pyogenes after exposure to penicillin: dependency on dose and inhibition by clindamycin.  

PubMed

The amount and time course of SpeA release from group A streptococci (GAS) was studied at different starting inoculate after exposure to different doses of penicillin, clindamycin or a combination of the 2. The release was related to the bacterial concentration and killing rate. A clinical GAS strain was exposed to benzylpenicillin, 2 and 1000 x MIC, clindamycin, 2 and 32 x MIC, or combinations of the 2. Samples for viable counts and SpeA analyses were drawn before and after the addition of antibiotics and at 3, 6 and 24 h. The SpeA release was higher at low than at high concentrations of penicillin and the combination (both, p<0.05). The addition of clindamycin to penicillin reduced SpeA production at both concentrations (p<0.01). Most SpeA was released before 3 h, and for penicillin and the combination, the amount correlated to the number of killed bacteria during this period (r=0.50; p<0.05). A positive correlation was found between the inoculum size and the SpeA concentration at time zero (r=0.54; p<0.05). The SpeA concentration was dependent on the initial number of bacteria, the class of antibiotic, the dose of penicillin and the killing rate. PMID:17148065

Goscinski, Gunilla; Tano, Eva; Thulin, Pontus; Norrby-Teglund, Anna; Sjölin, Jan

2006-01-01

259

Genome of the Bacterium Streptococcus pneumoniae Strain R6  

Microsoft Academic Search

Streptococcus pneumoniae is among the most significant causes of bacterial disease in humans. Here we report the 2,038,615-bp genomic sequence of the gram-positive bacterium S. pneumoniae R6. Because the R6 strain is avirulent and, more importantly, because it is readily transformed with DNA from homologous species and many heterologous species, it is the principal platform for investigation of the biology

JOANN HOSKINS; WILLIAM E. ALBORN; JEFFREY ARNOLD; LARRY C. BLASZCZAK; STANLEY BURGETT; BRADLEY S. DEHOFF; SHAWN T. ESTREM; LORI FRITZ; DONG-JING FU; WENDY FULLER; CHAD GERINGER; RAYMOND GILMOUR; JENNIFER S. GLASS; HAMID KHOJA; ANGELIKA R. KRAFT; ROBERT E. LAGACE; DONALD J. LEBLANC; LINDA N. LEE; ELLIOT J. LEFKOWITZ; JIN LU; PATTI MATSUSHIMA; SCOTT M. MCAHREN; MARGARET MCHENNEY; KEVIN MCLEASTER; CHRISTOPHER W. MUNDY; THALIA I. NICAS; FRANKLIN H. NORRIS; M. O'Gara; R. B. Peery; G. T. Robertson; P. Rockey; P.-M. Sun; M. E. Winkler; Y. Yang; M. Young-Bellido; G. Zhao; C. A. Zook; R. H. Baltz; S. R. Jaskunas; P. R. Rosteck; PAUL L. SKATRUD; JOHN I. GLASS

2001-01-01

260

Molecular characterization of an Australian serotype 1 Streptococcus pneumoniae outbreak.  

PubMed

SUMMARY Serotype 1 Streptococcus pneumoniae is a cause of invasive pneumococcal disease (IPD) worldwide and has been associated with IPD outbreaks, while carriage is rarely detected in healthy adults or children. This study details an Australian multi-state and territory outbreak of serotype 1 S. pneumoniae IPD between 2010 and 2012. Molecular characterization demonstrated the outbreak was largely due to the clonal expansion of sequence type 306, MLVA type 261 S. pneumoniae serotype 1. PMID:24666470

Staples, M; Graham, R M A; Jennison, A V; Ariotti, L; Hicks, V; Cook, H; Krause, V; Giele, C; Smith, H V

2015-01-01

261

Bacterial Virulence in the Moonlight: Multitasking Bacterial Moonlighting Proteins Are Virulence Determinants in Infectious Disease ?  

PubMed Central

Men may not be able to multitask, but it is emerging that proteins can. This capacity of proteins to exhibit more than one function is termed protein moonlighting, and, surprisingly, many highly conserved proteins involved in metabolic regulation or the cell stress response have a range of additional biological actions which are involved in bacterial virulence. This review highlights the multiple roles exhibited by a range of bacterial proteins, such as glycolytic and other metabolic enzymes and molecular chaperones, and the role that such moonlighting activity plays in the virulence characteristics of a number of important human pathogens, including Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Helicobacter pylori, and Mycobacterium tuberculosis. PMID:21646455

Henderson, Brian; Martin, Andrew

2011-01-01

262

A liver abscess deprived a healthy adult of eyesight: endogenous endophthalmitis associated with a pyogenic liver abscess caused by serotype K1 Klebsiella pneumonia.  

PubMed

Klebsiella pneumonia usually causes urinary tract infections, pneumonia, and other infectious diseases in hospitalized and immunocompromised patients. Among the types of Klebsiella pneumonia, serotype K1 is known to be a highly virulent pathogen. We herein report the case of a healthy 63-year-old man with a pyogenic liver abscess and bilateral endogenous endophthalmitis caused by serotype K1 Klebsiella pneumonia. Although the patient received percutaneous abscess drainage and antibiotic therapy, he lost his eyesight. To improve the poor prognoses of ocular complications, providing both an earlier diagnosis and treatment is critical. PMID:23583997

Maruno, Takahisa; Ooiwa, Yoko; Takahashi, Ken; Kodama, Yuzo; Takakura, Shunji; Ichiyama, Satoshi; Chiba, Tsutomu

2013-01-01

263

Skin Disease Presenting as an Outbreak of Pseudobacteremia in a Laboratory Worker  

Microsoft Academic Search

An outbreak of pseudobacteremia due to Streptococcus pyogenes (group A streptococci (GAS)) and methicil- lin-susceptible Staphylococcus aureus (MSSA) was traced to the venting procedure for aerobic bottles prior to their loading into the incubator of the BacT\\/Alert analyzer (Organon Teknika). Bacteria shed by a laboratory worker suffering from impetigo and cellulitis contaminated the aerobic bottles of 10 patients. All blood

A. Simhon; G. Rahav; M. Shapiro; C. Block

2001-01-01

264

RESEARCH ARTICLE Open Access Reductive evolution in Streptococcus agalactiae  

E-print Network

RESEARCH ARTICLE Open Access Reductive evolution in Streptococcus agalactiae and the emergence bottlenecks. The Gram positive bacteria Streptococcus agalactiae (also called GBS), responsible for septicemia evolutionary step marked by a higher frequency of large deletions. Keywords: Streptococcus agalactiae, Host

Paris-Sud XI, Université de

265

Hosts, environment, stress, phages Response of Streptococcus thermophilus CNRZ368  

E-print Network

Hosts, environment, stress, phages Response of Streptococcus thermophilus CNRZ368 and its colonial Vandoeuvre-lès-Nancy, France Abstract -- The aerotolerance of Streptococcus thermophilus raises the question variants. oxidative stress / conditional instability / morphotype / resistance / Streptococcus thermophilus

Boyer, Edmond

266

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

Code of Federal Regulations, 2010 CFR

...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 ); blackleg...

2010-04-01

267

Bilateral acute pyogenic conjunctivitis with iritis induced by unilateral topical application of bacterial peptidoglycan muramyl dipeptide in adult rabbits.  

PubMed

The factors responsible for the conjunctivitis and iritis associated with acute ocular infection and post enteric inflammatory disease are not fully known. The pro-inflammatory activity of unilateral topical application of muramyl dipeptide (MDP; the smallest bio-active Gram-positive and Gram-negative bacterial cell wall component) was investigated in adult rabbits. The resultant bilateral conjunctivitis/iritis and pyogenic responses were characterized. Bilateral symptoms were graded by slit lamp examinations; tear fluid, Schirmer tests (tear production), blood and aqueous humor (AH) samples were obtained from MDP-treated and untreated rabbits. MDP concentration, gamma-glutamyltranspeptidase activity (GGT; key enzyme in glutathione recapture, xenobiotic detoxification, eicosanoid synthesis and neutrophil function), protein concentration, and tear cell density, cytology, and immunofluorescent antibody reactivity to GGT and calreticulin (CRT; MDP-binding protein) were determined. MDP was cleared from ipsilateral tears and serum by 6 h, but was undetected in mock-treated contralateral tears. Bilateral signs of acute transient pyogenic conjunctivitis, characterized by tearing, lid edema, conjunctival hyperemia, chemosis and leukocytic infiltrate with iritis (erythema and aqueous flare) were detected. Milder symptoms occurred in the mock-treated contralateral eyes. Bilateral symptoms, tear production, tear protein, GGT activity, and mucopurulent discharge (containing up to 2.5-5.0 × 10(6) cells/mL) were elevated 4-8 h post MDP and resolved to near pre-treatment levels by 24 h. Tear GGT activity and protein levels were higher in MDP-treated and mock-treated contralateral eyes than in eyes of untreated adult rabbits (p's < 0.001). Elevated tear GGT activity was associated with histopathology and increased vascular and epithelial permeability to serum protein, GGT-positive epithelia cells, macrophages and heterophils. Repeat MDP applications induced recurrent induction and resolution patterns of bilateral conjunctivitis/iritis and tear GGT activity, but ipsilateral GGT responses were lower. The results suggest unilateral topical MDP application to adult rabbit eyes induces a bilateral acute pyogenic conjunctivitis/iritis (PCI) characterized by increased vascular and epithelial permeability similar to acute bacterial conjunctivitis in man. The detection of CRT/GGT positive heterophils in tears suggests efferocytosis (phagocytosis of dead/dying cells). Tear GGT activity may be a useful means to quantify MDP-induced toxicity and extraocular inflammation. PMID:24135297

Langford, Marlyn P; Foreman, Bridgett D; Srur, Lana; Ganley, James P; Redens, Thomas B

2013-11-01

268

Pyogenic granuloma on the upper lip: an unusual location  

PubMed Central

Pyogenic granuloma (PG) is a benign non-neoplastic mucocutaneous lesion. It is a reactional response to constant minor trauma and might be related to hormonal changes. In the mouth, PG is manifested as a sessile or pedunculated, resilient, erythematous, exophytic and painful papule or nodule with a smooth or lobulated surface that bleeds easily. PG preferentially affects the gingiva, but may also occur on the lips, tongue, oral mucosa and palate. The most common treatment is surgical excision. This paper describes a mucocutaneous PG on the upper lip, analyzing the clinical characteristics and discussing the features that distinguish this lesion from other similar oral mucosa lesions. The diagnosis of oral lesions is complex and leads the dentist to consider distinct lesions with different diagnostic methods. This case report with a 4 year-follow-up calls the attention to the uncommon mucocutaneous labial location of PG and to the fact that surgical excision is the safest method for diagnosis and treatment of PG of the lip, even when involving the mucosa and skin PMID:21085814

GONÇALES, Eduardo Sanches; DAMANTE, José Humberto; FISCHER RUBIRA, Cassia Maria; TAVEIRA, Luís Antônio de Assis

2010-01-01

269

Nicotine Regulates Streptococcus mutans Extracellular Polysaccharide and Related Protein Expression.  

E-print Network

Nicotine Regulates Streptococcus mutans Extracellular Polysaccharide and Related Protein Expression of Dentistry; 2 Department of Pathology and Laboratory Medicine, IU School of Medicine Streptococcus mutans

Zhou, Yaoqi

270

Hydrolytic enzymes of "Streptococcus milleri".  

PubMed Central

Seventy-two isolates classified as "Streptococcus milleri" were examined for the presence of various hydrolytic enzymes. While no protein or lipid-degrading activities were demonstrated, some isolates showed DNase and mucopolysaccharide-degrading activities. Beta-hemolytic isolates were more likely to produce these enzymes than were nonhemolytic strains. Isolates of one "S. milleri" biotype (mannitol fermentation positive) were uniformly devoid of all enzyme activities tested. PMID:2958496

Ruoff, K L; Ferraro, M J

1987-01-01

271

Case Report: Group B Streptococcus meningitis in an adolescent    

PubMed Central

Streptococcus agalactiae (group B Streptococcus, GBS) usually colonizes the gastrointestinal and lower genital tracts of asymptomatic hosts, yet the incidence of invasive disease is on the rise . We describe a case of an 18 year old woman, recently diagnosed with lupus, who reported a spontaneous abortion six weeks prior to her hospitalization.  She presented with fever, altered mental status, and meningeal signs, paired with a positive blood culture for GBS. Magnetic resonance imaging of her brain demonstrated an extra-axial fluid collection, and she was diagnosed with meningitis.  She received prolonged intravenous antibiotic therapy and aggressive treatment for lupus, leading to clinical recovery. This case illustrates the importance of recognizing GBS as a potential pathogen in all patients presenting with CNS infection .   PMID:25339988

Vittorino, Roselle; Hui-Yuen, Joyce; Ratner, Adam J.; Starr, Amy; McCann, Teresa

2014-01-01

272

Is Streptococcus bovis a urinary pathogen?  

PubMed

The Streptococcus bovis group (SBG) comprises several microorganisms associated with human infections. They have been associated with bacteremia, endocarditis, biliary tract infection, meningitis, and colorectal cancer, but their role as urinary pathogens is not well known. The objective of this investigation was to discover the incidence and clinical significance of the bacteriuria associated with this complex. A retrospective analysis of all adult patients with bacteriuria caused by SBG during the period 1995-2012 was carried out. During the study period, SBG was isolated in 153 adult patients, who had a mean age of 67 years, most of them being women (80 %). Most of our patients (65 %) had some underlying disease, with urologic disease being the most common (37 %), followed by diabetes mellitus (27 %) and neurologic disease (25 %). Among the 88 patients in whom we were able to correctly assess symptoms, 45 % had asymptomatic bacteriuria, 35 % had lower urinary tract infection, and 20 % had upper urinary tract infection. In 14 cases (9 %), SBG was also isolated in blood cultures. Most of the isolates of SBG (72 %) were S. gallolyticus subsp. pasteurianus. All isolates were susceptible to penicillin, 98 % to nitrofurantoin, and 77 % to fosfomycin. Although SBG bacteriuria is uncommon, it should not always be taken as a contaminant, mainly when S. pasteurianus is isolated, because it may cause urinary tract infections and, occasionally, sepsis, whereas when S. gallolyticus is isolated from urine, it may be a marker of underlying endocarditis and colorectal cancer. PMID:25416160

Matesanz, M; Rubal, D; Iñiguez, I; Rabuñal, R; García-Garrote, F; Coira, A; García-País, M J; Pita, J; Rodriguez-Macias, A; López-Álvarez, M J; Alonso, M P; Corredoira, J

2014-11-22

273

A Gray-purple Mass on the Floor of the Mouth: Gigantic Mucogingival Pyogenic Granuloma in a Teenage Patient  

PubMed Central

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

Brunet-LLobet, Lluís; Miranda-Rius, Jaume; Lahor-Soler, Eduard; Mrina, Ombeni; Nadal, Alfons

2014-01-01

274

Pyogenic granuloma of labial mucosa: A misnomer in an anomolous site  

PubMed Central

Pyogenic granuloma is tumor-like proliferation to a nonspecific infection. Clinically, pyogenic granuloma presents as sessile or pedunculated exophytic mass with a smooth or lobulated surface which has a tendency to bleed easily. These lesions tend to occur slightly more in females, frequently involving the gingiva of the maxillary region. Histologically, these lesions show an excessive proliferation of vascular type of connective tissue to a nonspecific infection. The most common treatment is surgical excision with eradication of local irritants. This case report describes a pyogenic granuloma on the labial mucosa in a 33-year-old male, discussing the clinical features and histopathologic features that distinguish this lesion from other similar oral mucosa lesions. PMID:23066251

Ravi, Vaiyapuri; Jacob, Mathew; Sivakumar, Aandamuthu; Saravanan, Srinivasan; Priya, Kesavan

2012-01-01

275

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

PubMed

Biochemical and molecular genetic studies were performed on two unidentified Gram-stain positive, catalase and oxidase negative, non-hemolytic Streptococcus-like organisms recovered from raw camel milk in Morocco. Phenotypic characterization and comparative 16S rRNA gene sequencing demonstrated that the two strains were highly different from each other and that they did not correspond to any recognized species of the genus Streptococcus. Phylogenetic analysis based on 16S rRNA gene sequences showed the unidentified organisms each formed a hitherto unknown sub-line within the genus Streptococcus, displaying a close affinity with Streptococcus moroccensis, Streptococcus minor and Streptococcus ovis. DNA G+C content determination, MALDI-TOF mass spectrometry and biochemical tests demonstrated the bacterial isolates represent two novel species. Based on the phenotypic distinctiveness of the new bacteria and molecular genetic evidence, it is proposed to classify the two strains as Streptococcus tangierensis sp. nov., with CCMM B832(T) (=LMG 27683(T)) as the type strain, and Streptococcus cameli sp. nov., with CCMM B834(T) (=LMG 27685(T)) as the type strain. PMID:25491120

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

2014-12-10

276

Subcutaneous immunization with inactivated bacterial components and purified protein of Escherichia coli, Fusobacterium necrophorum and Trueperella pyogenes prevents puerperal metritis in Holstein dairy cows.  

PubMed

In this study we evaluate the efficacy of five vaccine formulations containing different combinations of proteins (FimH; leukotoxin, LKT; and pyolysin, PLO) and/or inactivated whole cells (Escherichia coli, Fusobacterium necrophorum, and Trueperella pyogenes) in preventing postpartum uterine diseases. Inactivated whole cells were produced using two genetically distinct strains of each bacterial species (E. coli, F. necrophorum, and T. pyogenes). FimH and PLO subunits were produced using recombinant protein expression, and LKT was recovered from culturing a wild F. necrophorum strain. Three subcutaneous vaccines were formulated: Vaccine 1 was composed of inactivated bacterial whole cells and proteins; Vaccine 2 was composed of proteins only; and Vaccine 3 was composed of inactivated bacterial whole cells only. Two intravaginal vaccines were formulated: Vaccine 4 was composed of inactivated bacterial whole cells and proteins; and Vaccine 5 was composed of PLO and LKT. To evaluate vaccine efficacy, a randomized clinical trial was conducted at a commercial dairy farm; 371 spring heifers were allocated randomly into one of six different treatments groups: control, Vaccine 1, Vaccine 2, Vaccine 3, Vaccine 4 and Vaccine 5. Late pregnant heifers assigned to one of the vaccine groups were each vaccinated twice: at 230 and 260 days of pregnancy. When vaccines were evaluated grouped as subcutaneous and intravaginal, the subcutaneous ones were found to significantly reduce the incidence of puerperal metritis. Additionally, subcutaneous vaccination significantly reduced rectal temperature at 6±1 days in milk. Reproduction was improved for cows that received subcutaneous vaccines. In general, vaccination induced a significant increase in serum IgG titers against all antigens, with subcutaneous vaccination again being more effective. In conclusion, subcutaneous vaccination with inactivated bacterial components and/or protein subunits of E. coli, F. necrophorum and T. pyogenes can prevent puerperal metritis during the first lactation of dairy cows, leading to improved reproduction. PMID:24638139

Machado, Vinícius Silva; Bicalho, Marcela Luccas de Souza; Meira Junior, Enoch Brandão de Souza; Rossi, Rodolfo; Ribeiro, Bruno Leonardo; Lima, Svetlana; Santos, Thiago; Kussler, Arieli; Foditsch, Carla; Ganda, Erika Korzune; Oikonomou, Georgios; Cheong, Soon Hon; Gilbert, Robert Owen; Bicalho, Rodrigo Carvalho

2014-01-01

277

Subcutaneous Immunization with Inactivated Bacterial Components and Purified Protein of Escherichia coli, Fusobacterium necrophorum and Trueperella pyogenes Prevents Puerperal Metritis in Holstein Dairy Cows  

PubMed Central

In this study we evaluate the efficacy of five vaccine formulations containing different combinations of proteins (FimH; leukotoxin, LKT; and pyolysin, PLO) and/or inactivated whole cells (Escherichia coli, Fusobacterium necrophorum, and Trueperella pyogenes) in preventing postpartum uterine diseases. Inactivated whole cells were produced using two genetically distinct strains of each bacterial species (E. coli, F. necrophorum, and T. pyogenes). FimH and PLO subunits were produced using recombinant protein expression, and LKT was recovered from culturing a wild F. necrophorum strain. Three subcutaneous vaccines were formulated: Vaccine 1 was composed of inactivated bacterial whole cells and proteins; Vaccine 2 was composed of proteins only; and Vaccine 3 was composed of inactivated bacterial whole cells only. Two intravaginal vaccines were formulated: Vaccine 4 was composed of inactivated bacterial whole cells and proteins; and Vaccine 5 was composed of PLO and LKT. To evaluate vaccine efficacy, a randomized clinical trial was conducted at a commercial dairy farm; 371 spring heifers were allocated randomly into one of six different treatments groups: control, Vaccine 1, Vaccine 2, Vaccine 3, Vaccine 4 and Vaccine 5. Late pregnant heifers assigned to one of the vaccine groups were each vaccinated twice: at 230 and 260 days of pregnancy. When vaccines were evaluated grouped as subcutaneous and intravaginal, the subcutaneous ones were found to significantly reduce the incidence of puerperal metritis. Additionally, subcutaneous vaccination significantly reduced rectal temperature at 6±1 days in milk. Reproduction was improved for cows that received subcutaneous vaccines. In general, vaccination induced a significant increase in serum IgG titers against all antigens, with subcutaneous vaccination again being more effective. In conclusion, subcutaneous vaccination with inactivated bacterial components and/or protein subunits of E. coli, F. necrophorum and T. pyogenes can prevent puerperal metritis during the first lactation of dairy cows, leading to improved reproduction. PMID:24638139

Machado, Vinícius Silva; Bicalho, Marcela Luccas de Souza; Meira Junior, Enoch Brandão de Souza; Rossi, Rodolfo; Ribeiro, Bruno Leonardo; Lima, Svetlana; Santos, Thiago; Kussler, Arieli; Foditsch, Carla; Ganda, Erika Korzune; Oikonomou, Georgios; Cheong, Soon Hon; Gilbert, Robert Owen; Bicalho, Rodrigo Carvalho

2014-01-01

278

Human Streptococcus agalactiae strains in aquatic mammals and fish  

PubMed Central

Background In humans, Streptococcus agalactiae or group B streptococcus (GBS) is a frequent coloniser of the rectovaginal tract, a major cause of neonatal infectious disease and an emerging cause of disease in non-pregnant adults. In addition, Streptococcus agalactiae causes invasive disease in fish, compromising food security and posing a zoonotic hazard. We studied the molecular epidemiology of S. agalactiae in fish and other aquatic species to assess potential for pathogen transmission between aquatic species and humans. Methods Isolates from fish (n = 26), seals (n = 6), a dolphin and a frog were characterized by pulsed-field gel electrophoresis, multilocus sequence typing and standardized 3-set genotyping, i.e. molecular serotyping and profiling of surface protein genes and mobile genetic elements. Results Four subpopulations of S. agalactiae were identified among aquatic isolates. Sequence type (ST) 283 serotype III-4 and its novel single locus variant ST491 were detected in fish from Southeast Asia and shared a 3-set genotype identical to that of an emerging ST283 clone associated with invasive disease of adult humans in Asia. The human pathogenic strain ST7 serotype Ia was also detected in fish from Asia. ST23 serotype Ia, a subpopulation that is normally associated with human carriage, was found in all grey seals, suggesting that human effluent may contribute to microbial pollution of surface water and exposure of sea mammals to human pathogens. The final subpopulation consisted of non-haemolytic ST260 and ST261 serotype Ib isolates, which belong to a fish-associated clonal complex that has never been reported from humans. Conclusions The apparent association of the four subpopulations of S. agalactiae with specific groups of host species suggests that some strains of aquatic S. agalactiae may present a zoonotic or anthroponotic hazard. Furthermore, it provides a rational framework for exploration of pathogenesis and host-associated genome content of S. agalactiae strains. PMID:23419028

2013-01-01

279

nature biotechnology VOLUME 32 NUMBER 4 APRIL 2014 347 r e v i e w  

E-print Network

research and is a potential avenue for therapy of genetic diseases. Frameshift knockout mutations enable based on a bacterial CRISPR-associated protein 9 nuclease from Streptococcus pyogenes (hereafter

Kaski, Samuel

280

FUSOBACTERIUM NECROPHORUM AND ACTINOMYCES PYOGENES ASSOCIATED FACIAL AND MANDIBULAR ABSCESSES IN BLUE DUIKER  

Microsoft Academic Search

Anaerobic and aerobic cultures of facial and mandibular abscesses were made from 12 blue duiker (Cephalophus monticola fusicolor) housed at the Deer and Duiker Research Facility of the Pennsylvania State University (USA). Increases in concentrations of total protein and serum globulin occurred in all cases. Actinomyces pyogenes was isolated from nine animals. Fusobac- terium necrophorum was present in eight and

B. L. Roeder; M. M. Chengappa; K. F. Lechtenberg; T. G. Nagaraja; G. A. Varg

1989-01-01

281

Complete Genome Sequence of Trueperella pyogenes, an Important Opportunistic Pathogen of Livestock  

PubMed Central

Here, we report the complete genome sequence of Trueperella pyogenes TP6375, a strain isolated from the uterus of a dairy cow affected with metritis. The complete circular genome is 2,338,390 bp and contains several genes needed for pathogenicity. PMID:24786956

Machado, Vinicius S.

2014-01-01

282

Streptococcus agalactiae mastitis: a review.  

PubMed Central

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

Keefe, G P

1997-01-01

283

Conjugative Transfer and cis-Mobilization of a Genomic Island by an Integrative and Conjugative Element of Streptococcus agalactiae  

PubMed Central

Putative integrative and conjugative elements (ICEs), i.e., genomic islands which could excise, self-transfer by conjugation, and integrate into the chromosome of the bacterial host strain, were previously identified by in silico analysis in the sequenced genomes of Streptococcus agalactiae (M. Brochet et al., J. Bacteriol. 190:6913–6917, 2008). We investigated here the mobility of the elements integrated into the 3? end of a tRNALys gene. Three of the four putative ICEs tested were found to excise but only one (ICE_515_tRNALys) was found to transfer by conjugation not only to S. agalactiae strains but also to a Streptococcus pyogenes strain. Transfer was observed even if recipient cell already carries a related resident ICE or a genomic island flanked by attL and attR recombination sites but devoid of conjugation or recombination genes (CIs-Mobilizable Element [CIME]). The incoming ICE preferentially integrates into the 3? end of the tRNALys gene (i.e., the attR site of the resident element), leading to a CIME-ICE structure. Transfer of the whole composite element CIME-ICE was obtained, showing that the CIME is mobilizable in cis by the ICE. Therefore, genomic islands carrying putative virulence genes but lacking the mobility gene can be mobilized by a related ICE after site-specific accretion. PMID:23275243

Puymège, Aurore; Bertin, Stéphane; Chuzeville, Sarah; Guédon, Gérard

2013-01-01

284

Immunological cross-reactivity between Streptococcus mutans and human heart tissue examined by cross-immunization experiments.  

PubMed Central

Hyperimmunization of rabbits with Streptococcus mutans or other related cariogenic streptococci sometimes induces serum antibodies that react with human heart muscle. To determine whether antigen I/II (AgI/II), a major surface protein antigen present in most human isolates of these organisms, was responsible for inducing cross-reactive antibodies, we tested it for antigenic similarity to heart components, exploiting the ability of immune systems to mount anamnestic responses to antigens previously encountered. Mice immunized with a strain of Streptococcus pyogenes type M6, known to be heart cross-reactive, or with intact S. mutans cells developed antibodies that could be detected on a human heart sarcolemmal preparation. However, mice immunized with AgI/II and boosted with sarcolemma were unable to develop significant antisarcolemmal antibodies attributable to prior sensitization by AgI/II. Similarly, AgI/II was unable to recall antisarcolemmal responses in mice previously immunized with sarcolemma. Nevertheless, strong immunoglobulin G antibody responses to AgI/II were detected at the single-cell level in spleens and as circulating antibodies in all mice immunized with AgI/II or AgI/II-bearing S. mutans. We conclude that the ability of S. mutans to induce heart-reactive antibodies is not due to antigenic similarity between AgI/II and components of human heart but may be caused by other cross-reactive antigens in the bacterial cells or by nonspecific stimulation of the immune system. PMID:2228225

Wu, H Y; Russell, M W

1990-01-01

285

Draft Genome Sequence of a Nonhemolytic Fish-Pathogenic Streptococcus agalactiae Strain  

PubMed Central

Streptococcus agalactiae is a significant Gram-positive bacterial pathogen of terrestrial and aquatic animals. A subpopulation of nonhemolytic strains which appear to be pathogenic only for poikilotherms exists. We report here the first draft genome sequence of a nonhemolytic S. agalactiae isolate recovered from a diseased fish. PMID:23105075

Zadoks, Ruth N.; Lainson, Frederick A.; Ferguson, Hugh W.; Crumlish, Margaret; Turnbull, James F.; Fontaine, Michael C.

2012-01-01

286

Streptococcus iniae, a Human and Animal Pathogen: Specific Identification by the Chaperonin 60 Gene Identification Method  

PubMed Central

It was recently reported that Streptococcus iniae, a bacterial pathogen of aquatic animals, can cause serious disease in humans. Using the chaperonin 60 (Cpn60) gene identification method with reverse checkerboard hybridization and chemiluminescent detection, we identified correctly each of 12 S. iniae samples among 34 aerobic gram-positive isolates from animal and clinical human sources. PMID:9650992

Goh, Swee Han; Driedger, David; Gillett, Sandra; Low, Donald E.; Hemmingsen, Sean M.; Amos, Mayben; Chan, David; Lovgren, Marguerite; Willey, Barbara M.; Shaw, Carol; Smith, John A.

1998-01-01

287

Transcriptional Regulation in the Streptococcus pneumoniae rlrA Pathogenicity Islet by RlrA  

Microsoft Academic Search

The proper temporal expression of virulence genes during infection is crucial to the infectious life cycle of microbial pathogens, particularly in pathogens that encounter a multitude of environments in eukaryotic hosts. Streptococcus pneumoniae normally colonizes the nasopharynges of healthy adults but can cause a range of diseases at a variety of host sites. Transcriptional regulators that are essential for full

David L. Hava; Carolyn J. Hemsley; Andrew Camilli

2003-01-01

288

Identification and Epidemiology of Streptococcus iniae and S. agalactiae in tilapias Oreochromis spp.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Despite being known mainly as mammalian disease agents, Streptococcus iniae and S. agalactiae have become recognized as emerging pathogens of wild and cultured fish. The worldwide economic impact of S. iniae and S. agalactiae to the aquaculture industry is estimated in hundreds of millions annually...

289

Immunoproteomic analysis of the antibody response obtained in tilapia following immunization with a Streptococcus iniae vaccine  

Technology Transfer Automated Retrieval System (TEKTRAN)

Streptococcus iniae is one of the most economically important Gram-positive pathogens in cultured fish species worldwide. Research has shown that vaccination is a tool that can be used in the prevention of streptococcal disease. The USDA-ARS patented S. iniae vaccine has been demonstrated to be ef...

290

Streptococcus pneumoniae anchor to activated human cells by the receptor for platelet-activating factor  

Microsoft Academic Search

THE Gram-positive bacterium Streptococcus pneumoniae is a major cause of pneumonia, sepsis and meningitis1. Although the invasive disease is severe, some 40% of individuals harbour the pneumococcus in the nasopharynx asymptomatically2. Here we investigate the molecular elements of the encounter between host and pathogen that distinguish these different outcomes. We show that inflammatory activation of human cells shifts the targeting

Diana R. Cundell; Norma P. Gerard; Craig Gerard; Ilona Idanpaan-Heikkila; Elaine I. Tuomanen

1995-01-01

291

Possible Transmission of Streptococcus iniae from Wild Fish to Cultured Marine Fish  

PubMed Central

Streptococcus iniae was isolated from diseased wild fish collected near a mariculture facility where gilthead sea bream and European sea bass exhibited a similar infection. Species-specific PCR and ribotyping confirmed that wild and cultured fish were infected by a single S. iniae clone. Wild fish are therefore potential amplifiers of pathogenic S. iniae strains. PMID:9758844

Zlotkin, Amir; Hershko, Hannah; Eldar, Avi

1998-01-01

292

Sequencing and Comparative Genome Analysis of Two Pathogenic Streptococcus gallolyticus Subspecies: Genome Plasticity, Adaptation and Virulence  

Microsoft Academic Search

Streptococcus gallolyticus infections in humans are often associated with bacteremia, infective endocarditis and colon cancers. The disease manifestations are different depending on the subspecies of S. gallolyticus causing the infection. Here, we present the complete genomes of S. gallolyticus ATCC 43143 (biotype I) and S. pasteurianus ATCC 43144 (biotype II.2). The genomic differences between the two biotypes were characterized with

I.-Hsuan Lin; Tze-Tze Liu; Yu-Ting Teng; Hui-Lun Wu; Yen-Ming Liu; Keh-Ming Wu; Chuan-Hsiung Chang; Ming-Ta Hsu; Niyaz Ahmed

2011-01-01

293

Surgical Treatment of Pyogenic Spondylitis with the Use of Freeze-Dried Structural Allograft  

PubMed Central

Objective Radical debridement and reconstruction is necessary for surgical treatment of pyogenic spondylitis to control infection and to provide segmental stability. The authors identified 25 patients who underwent surgery for pyogenic spondylitis using freeze-dried structural allograft for reconstruction. This study aimed to evaluate and demonstrate the effectiveness and safety of a freeze-dried structural allograft during the surgical treatment of pyogenic spondylitis. Methods From January 2011 to May 2013, we retrospectively reviewed 25 surgically treated patients of pyogenic spondylitis. Surgical techniques used were anterior radical debridement and reconstruction with a freeze-dried structural allograft and instrumentation. In these 25 patients, we retrospectively examined whether the symptoms had improved and the infection was controlled after surgery by evaluating laboratory data, clinical and radiological outcomes. The average follow-up period was 15.7 months (range, 12.2-37.5 months). Results The infection resolved in all of the patients and there were no cases of recurrent infection. The mean Visual Analog Scale score was 6.92 (range, 5-10) before surgery and 1.90 (range, 0-5) at the time of the last follow-up. Preoperatively, lower extremity motor deficits related to spinal infection were noted in 10 patients, and they improved in 7 patients after surgery. Follow-up computed tomographic scans were obtained from 10 patients, and osseous union between the vertebral body and the structural allograft was achieved in 2 patients. Conclusion The freeze-dried structural allograft can be a safe and effective alternative for surgical treatment of pyogenic spondylitis, and another option for vertebral reconstruction instead of using the other materials. PMID:25346759

Kim, Seung-Soo; Yoon, Jong-Won; Park, Hyun; Lee, Chul-Hee; Hwang, Soo-Hyun

2014-01-01

294

Group B Streptococcus: global incidence and vaccine development  

PubMed Central

An ongoing public health challenge is to develop vaccines that are effective against infectious diseases that have global relevance. Vaccines against serotypes of group B Streptococcus (GBS) that are prevalent in the United States and Europe are not optimally efficacious against serotypes common to other parts of the world. New technologies and innovative approaches are being used to identify GBS antigens that overcome serotype-specificity and that could form the basis of a globally effective vaccine against this opportunistic pathogen. This Review highlights efforts towards this goal and describes a template that can be followed to develop vaccines against other bacterial pathogens. PMID:17088932

Johri, Atul Kumar; Paoletti, Lawrence C.; Glaser, Philippe; Dua, Meenakshi; Sharma, Puja Kumari; Grandi, Guido; Rappuoli, Rino

2009-01-01

295

Streptococcus group C meningitis with cavernous sinus thrombosis  

PubMed Central

Group C Streptococcus (GCS) is a rare cause of bacteremia in humans. It is mostly associated with zoonological infections. Although GCS can be part of the normal oral, skin, and genitourinary fora, an infection with this pathogen can be highly virulent, causing rapid, disseminating disease. With a mortality of about 25%, the poor prognosis is linked to the severity of illness and the high level of virulence of the organism. Only a few cases of GCS meningitis have been reported. We present the first case of GCS meningitis with cavernous sinus thrombosis. PMID:23966796

Clarke, Mattew; Enuh, Hilary; Saverimuttu, Jessie; Nfonoyim, Jay

2013-01-01

296

A decade of molecular pathogenomic analysis of group A Streptococcus  

PubMed Central

Molecular pathogenomic analysis of the human bacterial pathogen group A Streptococcus has been conducted for a decade. Much has been learned as a consequence of the confluence of low-cost DNA sequencing, microarray technology, high-throughput proteomics, and enhanced bioinformatics. These technical advances, coupled with the availability of unique bacterial strain collections, have facilitated a systems biology investigative strategy designed to enhance and accelerate our understanding of disease processes. Here, we provide examples of the progress made by exploiting an integrated genome-wide research platform to gain new insight into molecular pathogenesis. The studies have provided many new avenues for basic and translational research. PMID:19729843

Musser, James M.; Shelburne, Samuel A.

2009-01-01

297

Quorum sensing in group A Streptococcus  

PubMed Central

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

Jimenez, Juan Cristobal; Federle, Michael J.

2014-01-01

298

Quorum sensing in group A Streptococcus.  

PubMed

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

Jimenez, Juan Cristobal; Federle, Michael J

2014-01-01

299

DrsG from Streptococcus dysgalactiae subsp. equisimilis Inhibits the Antimicrobial Peptide LL-37  

PubMed Central

SIC and DRS are related proteins present in only 4 of the >200 Streptococcus pyogenes emm types. These proteins inhibit complement-mediated lysis and/or the activity of certain antimicrobial peptides (AMPs). A gene encoding a homologue of these proteins, herein called DrsG, has been identified in the related bacterium Streptococcus dysgalactiae subsp. equisimilis. Here we show that geographically dispersed isolates representing 14 of 50 emm types examined possess variants of drsG. However, not all isolates within the drsG-positive emm types possess the gene. Sequence comparisons also revealed a high degree of conservation in different S. dysgalactiae subsp. equisimilis emm types. To examine the biological activity of DrsG, recombinant versions of two major DrsG variants, DrsGS and DrsGL, were expressed and purified. Western blot analysis using antisera raised to these proteins demonstrated both variants to be expressed and secreted into culture supernatants. Unlike SIC, but similar to DRS, DrsG does not inhibit complement-mediated lysis. However, like both SIC and DRS, DrsG is a ligand of the cathelicidin LL-37 and is inhibitory to its bactericidal activity in in vitro assays. Conservation of prolines in the C-terminal region also suggests that these residues are important in the biology of this family of proteins. This is the first report demonstrating the activity of an AMP-inhibitory protein in S. dysgalactiae subsp. equisimilis and suggests that inhibition of AMP activity is the primary function of this family of proteins. The acquisition of the complement-inhibitory activity of SIC may reflect its continuing evolution. PMID:24664506

Smyth, Danielle; Cameron, Ainslie; Davies, Mark R.; McNeilly, Celia; Hafner, Louise; Sriprakash, Kadaba S.

2014-01-01

300

Paclitaxel-associated subungual pyogenic granuloma: report in a patient with breast cancer receiving paclitaxel and review of drug-induced pyogenic granulomas adjacent to and beneath the nail.  

PubMed

Subungual and periungual pyogenic granuloma occur in association with certain systemic medications. Paclitaxel is an antitumor drug of the taxane family used in the management of breast cancer. Taxanes have many associated nail changes that may occur in patients receiving either docetaxel or paclitaxel for systemic chemotherapy. The nail changes in a 68-year-old woman with metastatic breast cancer who presented for nail changes after receiving 12 cycles of weekly paclitaxel are described herein: nail plate red-brown discoloration, onycholysis with leukonychia, proximal subungual hemorrhage, and subungual pyogenic granuloma. The literature on systemic medications associated with the development of subungual and periungual pyogenic granulomas is reviewed; drugs associated with the development of pyogenic granuloma at the locations include antineoplastics, antiretrovirals, epidermal growth factor receptor inhibitors, immunosuppressants and retinoids. In conclusion, subungual pyogenic granuloma can occur not only in patients receiving docetaxel, but also in patients treated with paclitaxel. And, paclitaxel should be included in the list of drugs associated with the occurrence of subungual pyogenic granuloma. PMID:22270214

Paul, Laura J; Cohen, Philip R

2012-02-01

301

CSFGGiardia sirapseudonana  

E-print Network

Bacillus halodurans Oceanobacillus iheyensis Ente rococcus fa ecalis Lactococcus la ctis Streptococcus pneum onia e R6 Streptococcus pneum onia e TIG R4 Streptococcus agala ctia e III Streptococcus agala ctia e V Streptococcus pyogenes M 1 Streptococcus pyogenes M GAS8232 Strepto coccus pyogenes M GAS315

Shoubridge, Eric

302

Group A Streptococcal (GAS) Disease  

MedlinePLUS

... Cancel Submit Search The CDC Group A Streptococcal (GAS) Disease Note: Javascript is disabled or is not ... Share Compartir Group A Streptococcus (group A strep, GAS) bacteria can live in a person's nose and ...

303

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

PubMed Central

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

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

2014-01-01

304

Anterior instrumentation for the treatment of pyogenic vertebral osteomyelitis of thoracic and lumbar spine  

Microsoft Academic Search

Anterior radical debridement and bone grafting is popular in the treatment of pyogenic infection of the spine, but there remains\\u000a great concern of placing instrumentation in the presence of infection because of the potentiality of infection recurrence\\u000a after surgery. The objective of this study was to prospectively evaluate the efficacy and safety of anterior instrumentation\\u000a in patients who underwent simultaneous

Li-Yang Dai; Wei-Hua Chen; Lei-Sheng Jiang

2008-01-01

305

The use of surgical Nd:YAG laser in an oral pyogenic granuloma: a case report.  

PubMed

Pyogenic granuloma is a benign, non-neoplastic, mucocutaneous lesion and is especially common on the tongue, lips, and gums. This case report presents a large oral pyogenic granuloma of the gingiva and the surgical treatment of this lesion with Nd:YAG laser. A 14-year-old female patient referred with a complaint of a swelling and growth on the buccal side of her mandibular left premolar teeth. A comprehensive intraoral examination revealed a localized gingival mass between mandibular left premolar teeth on the buccal aspect. The treatment selected was surgical removal using Nd:YAG laser with the following irradiation parameters: power output 4 W, energy 100 mJ, frequency 40 Hz, and pulsed emission mode. During surgery, complications including hemorrhage were not observed, and no scarring developed after surgery. The excised area gradually improved within 1 month. The use of Nd:YAG laser in the treatment of pyogenic granuloma reduced bleeding during surgery, with a consequent reduction in operating time, promoted rapid postoperative hemostasis, and has better patient acceptance. PMID:24689434

Kocaman, Gülhan; Beldüz, Nihal; Erdogan, Ceren; Ozbek, Elvan; Sadik, Elif; Kara, Cankat

2014-08-01

306

Galactokinase activity in Streptococcus thermophilus  

SciTech Connect

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

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

1985-10-01

307

Functional amyloid formation by Streptococcus mutans.  

PubMed

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

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

2012-12-01

308

Functional amyloid formation by Streptococcus mutans  

PubMed Central

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

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

2012-01-01

309

Hosts, environment, stress, phages Application of Streptococcus thermophilus DPC1842  

E-print Network

Hosts, environment, stress, phages Application of Streptococcus thermophilus DPC1842 as an adjunct lactococcal phage attack. Streptococcus thermophilus / adjunct / Cheddar / bacteriophage Résumé -- Ajout de Streptococcus thermophilus DPC1842 à la flore lactococcale utilisée en fabrication de Cheddar pour contrecarrer

Paris-Sud XI, Université de

310

Introduction Streptococcus pneumoniae (SPN) is a major human pathogen that  

E-print Network

Introduction Streptococcus pneumoniae (SPN) is a major human pathogen that produces pneumonia of NF is group A Streptococcus (GAS); mixed aerobic/anaerobic aetiolo- gies are also well-documented.5 Fasciitis Due to Penicillin-resistant Streptococcus pneumoniae: Case Report and Review of the Literature G

Nizet, Victor

311

Hyaluronan Breakdown Contributes to Immune Defense against Group A Streptococcus*  

E-print Network

Hyaluronan Breakdown Contributes to Immune Defense against Group A Streptococcus* Received, La Jolla, California 92093 Background: The role of hyaluronan catabolism in group A Streptococcus be a previously unrecognized mechanism for host defense. Group A Streptococcus (GAS) commonly infects human skin

Nizet, Victor

312

Kinetics of Coinfection with Influenza A Virus and Streptococcus pneumoniae  

E-print Network

Kinetics of Coinfection with Influenza A Virus and Streptococcus pneumoniae Amber M. Smith1 between influenza and certain bacteria, particularly Streptococcus pneumoniae, but the precise processes, Gutenkunst RN, McAuley JL, et al. (2013) Kinetics of Coinfection with Influenza A Virus and Streptococcus

Adler, Fred

313

Original article Sortase anchored proteins of Streptococcus uberis  

E-print Network

Original article Sortase anchored proteins of Streptococcus uberis play major roles March 2010; accepted 2 June 2010) Abstract ­ Streptococcus uberis, strain 0140J, contains a single copy / sortase / vaccine 1. INTRODUCTION Streptococcus uberis is one of the most com- mon pathogens isolated from

Boyer, Edmond

314

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

SciTech Connect

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

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

1986-11-01

315

Naturally Occurring Disseminated Group B Streptococcus Infections in Postnatal Rats  

PubMed Central

Group B Streptococcus (Streptococcus agalactiae, GBS) is a gram-positive commensal and occasional opportunistic pathogen of the human vaginal, respiratory, and intestinal tracts that can cause sepsis, pneumonia, or meningitis in human neonates, infants, and immunosuppressed persons. We report here on a spontaneous outbreak of postnatal GBS-associated disease in rats. Ten of 26 (38.5%) 21- to 24-d-old rat pups died or were euthanized due to a moribund state in a colony of rats transgenic for the human diphtheria toxin receptor on a Munich–Wistar–Frömter genetic background. Four pups had intralesional coccoid bacteria in various organs without accompanying inflammation. GBS was isolated from the liver of 2 of these pups and from skin abscesses in 3 littermates. A connection with the transgene could not be established. A treatment protocol was evaluated in the remaining breeding female rats. GBS is a potentially clinically significant spontaneous infection in various populations of research rats, with some features that resemble late-onset postnatal GBS infection in human infants. PMID:23561938

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

2013-01-01

316

Quorum sensing and biofilms in the pathogen, Streptococcus pneumoniae.  

PubMed

Bacteria are able to colonize and thrive in a variety of different environments as a biofilm, but only within the last half century new insights have been gained in this complex biosystem. Bacterial biofilms play a major role in human health by forming a defensive barrier against antibacterial chemical therapeutics and other potential pathogens, and in infectious disease when the bacteria invade normally sterile compartments. Quorum sensing is the signaling network for cell-to-cell communication and utilized by bacteria to regulate biofilms and other cellular processes. This review will describe recent advances in quorum sensing and biofilms. Initially, it will focus on Streptococcus pneumoniae biofilm regulation and the involvement of the ComABCDE pathway. As part of this review an original analysis of the genotypic and phenotypic variation of the signaling molecule, ComC and its cognate receptor ComD, firstly within the pneumococcal species and then within the genus Streptococcus will be presented. Additionally, a pathway similar to ComABCDE, the BlpABCSRH that regulates bacteriocin and immunity protein production that inhibit the growth of competing bacteria will be described. This review will then examine a third quorum sensing mechanism in the pneumococcus, the LuxS/AI-2, and present a novel gene and protein sequence comparative analysis that indicates its occurrence is more universal across bacterial genera compared with the Com pathway, with more sequence similarities between bacterial genera that are known to colonize the mucosal epithelium. PMID:25189864

Galante, Joana; Ho, Alfred C-Y; Tingey, Sarah; Charalambous, Bambos M

2015-01-01

317

Monoclonal Idiotope Vaccine against Streptococcus pneumoniae Infection  

NASA Astrophysics Data System (ADS)

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

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

1984-12-01

318

Hemorrhage in the Wall of Pyogenic Brain Abscess on Susceptibility Weighted MR Sequence: A Report of 3 Cases  

PubMed Central

Background and Purpose. In pyogenic brain abscess, hemorrhage in the walls is considered exceptional. Recently, hemorrhagic changes in the walls of pyogenic abscess have been demonstrated on susceptibility weighted imaging with 3T MRI. Here, we report hemorrhagic changes in the walls of pyogenic brain abscess on susceptibility weighted imaging with 1.5T MRI. Method. MRI of brain was done using 1.5T MRI with diffusion weighted sequence, susceptibility weighted sequence, and other standard sequences in 3 consecutive cases of pyogenic brain abscess. Stereotactic biopsy and cultures were obtained in 2 cases. One case was treated empirically with antibiotics. Results. Susceptibility sequence demonstrated hemorrhage in the wall of brain abscess in all three cases. All three cases also demonstrated restricted diffusion on diffusion weighted imaging. Conclusion. Susceptibility weighted imaging can demonstrate hemorrhagic changes in the walls of pyogenic brain abscess on 1.5T MRI. Presence of hemorrhage in the walls of ring enhancing lesions should not automatically lead to a diagnosis of tumor. PMID:25309770

Agarwal, Amit K.; Sabat, Shyamsunder B.; Nguyen, Dan T.

2014-01-01

319

77 FR 735 - New Animal Drugs; Cephalosporin Drugs; Extralabel Animal Drug Use; Order of Prohibition  

Federal Register 2010, 2011, 2012, 2013, 2014

...tissue infections caused by Staphylococcus aureus and Streptococcus pyogenes...aeruginosa, Serratia marcescens, Staphylococcus aureus, Streptococcus pneumoniae...Streptococcus agalactiae and Staphylococcus aureus. C. Mechanism of...

2012-01-06

320

21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.  

Code of Federal Regulations, 2013 CFR

...Hemolytic staphylococcus, Streptococcus spp., Bacterial pulmonary...by Brucella bronchiseptica, Streptococcus pyogenes, Staphylococcus aureus...Brucella bronchiseptica, Streptococcus spp. (2) The drug...

2013-04-01

321

21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.  

Code of Federal Regulations, 2012 CFR

...Hemolytic staphylococcus, Streptococcus spp., Bacterial pulmonary...by Brucella bronchiseptica, Streptococcus pyogenes, Staphylococcus aureus...Brucella bronchiseptica, Streptococcus spp. (2) The drug...

2012-04-01

322

21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.  

Code of Federal Regulations, 2014 CFR

...Hemolytic staphylococcus, Streptococcus spp., Bacterial pulmonary...by Brucella bronchiseptica, Streptococcus pyogenes, Staphylococcus aureus...Brucella bronchiseptica, Streptococcus spp. (2) The drug...

2014-04-01

323

21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.  

Code of Federal Regulations, 2011 CFR

...Hemolytic staphylococcus, Streptococcus spp., Bacterial pulmonary...by Brucella bronchiseptica, Streptococcus pyogenes, Staphylococcus aureus...Brucella bronchiseptica, Streptococcus spp. (2) The drug...

2011-04-01

324

Extensive Adaptive Changes Occur in the Transcriptome of Streptococcus agalactiae (Group B Streptococcus) in Response to Incubation with Human Blood  

PubMed Central

To enhance understanding of how Streptococcus agalactiae (group B streptococcus, GBS) adapts during invasive infection, we performed a whole-genome transcriptome analysis after incubation with whole human blood. Global changes occurred in the GBS transcriptome rapidly in response to blood contact following shift from growth in a rich laboratory medium. Most (83%) of the significantly altered transcripts were down-regulated after 30 minutes of incubation in blood, and all functional categories of genes were abundantly represented. We observed complex dynamic changes in the expression of transcriptional regulators and stress response genes that allow GBS to rapidly adapt to blood. The transcripts of relatively few proven virulence genes were up-regulated during the first 90 minutes. However, a key discovery was that genes encoding proteins involved in interaction with the host coagulation/fibrinolysis system and bacterial-host interactions were rapidly up-regulated. Extensive transcript changes also occurred for genes involved in carbohydrate metabolism, including multi-functional proteins and regulators putatively involved in pathogenesis. Finally, we discovered that an incubation temperature closer to that occurring in patients with severe infection and high fever (40°C) induced additional differences in the GBS transcriptome relative to normal body temperature (37°C). Taken together, the data provide extensive new information about transcriptional adaptation of GBS exposed to human blood, a crucial step during GBS pathogenesis in invasive diseases, and identify many new leads for molecular pathogenesis research. PMID:18769548

Mereghetti, Laurent; Sitkiewicz, Izabela; Green, Nicole M.; Musser, James M.

2008-01-01

325

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

PubMed

Two catalase- and oxidase-negative Streptococcus-like strains, LMG 27682(T) and LMG 27684(T), were isolated from raw camel milk in Morocco. Comparative 16S rRNA gene sequencing assigned these bacteria to the genus Streptococcus with Streptococcus rupicaprae 2777-2-07(T) as their closest phylogenetic neighbour (95.9% and 95.7% similarity, respectively). 16S rRNA gene sequence similarity between the two strains was 96.7%. Although strains LMG 27682(T) and LMG 27684(T) shared a DNA-DNA hybridization value that corresponded to the threshold level for species delineation (68%), the two strains could be distinguished by multiple biochemical tests, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes and by their MALDI-TOF MS profiles. On the basis of these considerable phenotypic and genotypic differences, we propose to classify both strains as novel species of the genus Streptococcus, for which the names Streptococcus moroccensis sp. nov. (type strain, LMG 27682(T) ?= CCMM B831(T)) and Streptococcus rifensis sp. nov. (type strain, LMG 27684(T) ?= CCMM B833(T)) are proposed. PMID:24786712

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

2014-07-01

326

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

PubMed

Four Gram-stain-positive, catalase-negative, coccoid-shaped organisms were isolated from elephant oral cavities. The isolates were tentatively identified as streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequencing studies confirmed the organisms to be members of the genus Streptococcus. Two isolates (NUM 6304(T) and NUM 6312) were related most closely to Streptococcus salivarius with 96.8?% and 93.1?% similarity based on the 16S rRNA gene and the RNA polymerase ? subunit encoding gene (rpoB), respectively, and to Streptococcus vestibularis with 83.7?% similarity based on the 60 kDa heat-shock protein gene (groEL). The other two isolates (NUM 6306(T) and NUM 6318) were related most closely to S. vestibularis with 97.0?% and 82.9?% similarity based on the 16S rRNA and groEL genes, respectively, and to S. salivarius with 93.5?% similarity based on the rpoB gene. Based on phylogenetic and phenotypic evidence, these isolates are suggested to represent novel species of the genus Streptococcus, for which the names Streptococcus loxodontisalivarius sp. nov. (type strain NUM 6304(T)?=?JCM 19287(T)?=?DSM 27382(T)) and Streptococcus saliviloxodontae sp. nov. (type strain NUM 6306(T)?=?JCM 19288(T)?=?DSM 27513(T)) are proposed. PMID:24994777

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

2014-09-01

327

Hospital-acquired infection with Streptococcus pneumoniae.  

PubMed

A prospective survey was carried out in the winter of 1983-84 to determine the incidence of hospital-acquired pneumococcal chest infection in a district general hospital. Twenty-one patients (of a total of 103 infected with Streptococcus pneumoniae) were assessed as having hospital-acquired infection. The implication of this and the need for further studies are discussed. PMID:2859331

Davies, A J; Dyas, A

1985-03-01

328

Characterization of Streptococcus thermophilus phages from cheese  

Microsoft Academic Search

Ten Streptococcus thermophilus phages isolated from commercial and natural starter cultures have been characterized on the basis of their host range, genome size, and restriction digest profiles. All phage DNAs exhibited distinct digestion profiles, seven phage genomes showed cohesive ends, and the sizes ranged between 36 to 42 Kb. Data obtained showed a large variability among all phages except for

M. ZAGO; D. CARMINATI; G. GIRAFFA

329

Incidence and Pathogenic Effect of Streptococcus pseudopneumoniae  

PubMed Central

We evaluated the incidence of Streptococcus pseudopneumoniae in clinical isolates by phenotypic methods and DNA-DNA hybridization. The pathogenic role of this organism was investigated with the mouse peritonitis/sepsis model. Our results show a low incidence (1/120 pneumococcal isolates) and a potential pathogenic effect for S. pseudopneumoniae. PMID:16757628

Harf-Monteil, Colette; Granello, Carole; Le Brun, Cécile; Monteil, Henri; Riegel, Philippe

2006-01-01

330

9230 FECAL ENTEROCOCCUS/STREPTOCOCCUS GROUPS  

EPA Science Inventory

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

331

Mucosal and systemic immune responses to a recombinant protein expressed on the surface of the oral commensal bacterium Streptococcus gordonii after oral colonization.  

PubMed Central

To circumvent the need to engineer pathogenic microorganisms as live vaccine-delivery vehicles, a system was developed which allowed for the stable expression of a wide range of protein antigens on the surface of Gram-positive commensal bacteria. The human oral commensal Streptococcus gordonii was engineered to surface express a 204-amino acid allergen from hornet venom (Ag5.2) as a fusion with the anchor region of the M6 protein of Streptococcus pyogenes. The immunogenicity of the M6-Ag5.2 fusion protein was assessed in mice inoculated orally and intranasally with a single dose of recombinant bacteria, resulting in the colonization of the oral/pharyngeal mucosa for 10-11 weeks. A significant increase of Ag5.2-specific IgA with relation to the total IgA was detected in saliva and lung lavages when compared with mice colonized with wild-type S. gordonii. A systemic IgG response to Ag5.2 was also induced after oral colonization. Thus, recombinant Gram-positive commensal bacteria may be a safe and effective way of inducing a local and systemic immune response. Images Fig. 1 Fig. 2 Fig. 4 PMID:7624334

Medaglini, D; Pozzi, G; King, T P; Fischetti, V A

1995-01-01

332

Meningitis in a pregnant woman caused by Streptococcus dysgalactiae subspecies equisimilis.  

PubMed

Infection of the central nervous system by streptococci is known to result in severe bacterial meningitis, however some strains have low pathogenic potential and affect the brain only in immunocompromised patients. Here we report the first case of an otherwise healthy non immunocompromised young adult woman who developed meningitis caused by Streptococcus dysgalactiae subspecies equisimilis. The patient was in the 17th week of her 3rd pregnancy. The course of the disease was quickly remittent under antibiotic treatment. PMID:24053027

Waltereit, Robert; Herrlinger, Ulrich; Stark, Maik; Borgmann, Stefan

2013-01-01

333

Contribution of glutamine synthetase to the virulence of Streptococcus suis serotype 2  

Microsoft Academic Search

Streptococcus suis serotype 2 (S. suis 2) is an important pathogen, responsible for diverse diseases in swine and human. In this study, we investigated the role of the glutamine synthetase (GlnA) in the pathogenesis of S. suis 2 in mice. To assess the contribution of glutamine synthetase (GlnA) to the virulence of S. suis 2, an knockout mutant (?glnA) unable

Youhui Si; Fangyan Yuan; Haitao Chang; Xijian Liu; Hongru Li; Kai Cai; Zhuofei Xu; Qinfeng Huang; Weicheng Bei; Huanchun Chen

2009-01-01

334

Posterior Lumbar Interbody Fusion Using Compressive Bone Graft with Allograft and Autograft in the Pyogenic Discitis  

PubMed Central

Study Design This is a retrospective study. Purpose To evaluate the advantages and effects of posterior lumbar interbody fusion (PLIF) using allograft and posterior instrumentation in the lumbar pyogenic discitis, which are resistant to antibiotics. Overview of Literature To present preliminary results of PLIF using a compressive bone graft with allograft and pedicle screw fixation in the lumbar pyogenic discitis. Methods Fifteen patients who had lumbar pyogenic discitis were treated by posterior approach from May 2004 to July 2008. The mean follow-up duration was 27.2 ± 18.68 months. The standing radiographs of the lumbar spine and clinical results were compared and analyzed in order to assess the bony union, the changes in the distance between the two vertebral bodies and the changes in the lordotic angle formed between the fused bodies immediately after surgery and at the final follow-up. Results Fifteen solid unions at an average of 15.2 ± 3.5 weeks after operation. The mean preoperative lordotic angle of the affected segments was 14.3 ± 15.1°, compared to 20.3 ± 12.3° after surgery and 19.8 ± 15.2° at last follow-up. For the functional result according to the Kirkaldy-Willis criteria, the outcome was excellent in 9, good in 5, fair in 1, and there were no poor cases. The average visual analogue scale score was decreased from 7.4 before surgery to 3.4 at 2 weeks postoperative. Conclusions The main advantage in the procedure of PLIF using compressive bone graft with allograft and post instrumentation is early ambulation. We believe that this is another good procedure for patients with poor general condition because a further autograft bone harvest is not required. PMID:22439083

An, Ki Chan; Kim, Tae Hyoung; Kim, Jin Suck; Park, Dae Hyoun; Kim, Jeon Gyo; Sung, Tae Woo

2012-01-01

335

Evaluation of an internally controlled real-time polymerase chain reaction assay targeting the groEL gene for the detection of Bartonella spp. DNA in patients with suspected cat-scratch disease.  

PubMed

Bartonella (B.) henselae is the causative agent of cat-scratch disease (CSD), which usually presents as a self-limiting lymphadenopathy. This study reports the development and evaluation of an internally controlled real-time polymerase chain reaction targeting the groEL gene for detection of Bartonella spp. DNA was extracted using the MagNA Pure system. The lower detection limit was 10-100 fg DNA and the in vitro sensitivity of the assay was not affected by duplexing with an internal control PCR. The real-time PCR assay detected DNA from all five B. henselae strains tested, and from B. birtlesii, B. vinsonii subsp. vinsonii, B. vinsonii subsp. arupensis and B. doshiae. The assay generated negative results with a selection of other bacteria, including several Mycobacterium spp., Streptococcus pyogenes and Staphylococcus aureus. Results of real-time PCR in clinical samples were compared with those of a conventional 16S rDNA-based PCR assay. During the period described in the Material and methods section, real-time PCR and conventional 16S PCR were performed on 73 clinical samples. Of these samples, 29 (40%) were found to give positive results and 44 (60%) gave negative results, both by real-time PCR and by conventional PCR, with a 100% agreement between the two tests. The PCR developed in this study is a rapid, sensitive, and simple method for the detection of Bartonella spp. in CSD and is suitable for implementation in the diagnostic laboratory. PMID:17624560

Diederen, B M W; Vermeulen, M J; Verbakel, H; van der Zee, A; Bergmans, A; Peeters, M F

2007-09-01

336

Pyogenic vertebral osteomyelitis complicating abdominal penetrating injury: case report and review of the literature  

PubMed Central

Pyogenic vertebral osteomyelitis is a rare condition usually associated with endocarditis or spinal surgery. However, it may also occur following abdominal penetrating trauma with associated gastrointestinal perforation. Diagnosis might be challenging and appropriate treatment is essential to ensure a positive outcome. In trans-abdominal trauma, 48 hours of broad-spectrum antibiotics is generally recommended for prophylaxis of secondary infections. A case report of vertebral osteomyelitis complicating trans-colonic injury to the retroperitoneum is presented and clinical management is discussed in the light of literature review. PMID:24373134

2013-01-01

337

A middle-aged lady with a pyogenic liver abscess caused by Clostridium perfringens  

PubMed Central

The pyogenic liver abscess caused by Clostridium perfringens (C. perfringens) is a rare, but rapidly fatal infection. It is usually associated with malignancy and immunosuppression. We report the case of 50-year-old lady with the secondary liver metastases from rectal cancer presented with fever and epigastric pain. The identification of Gram-positive bacilli septicaemia, the presence of gas-forming liver abscess and massive intravascular hemolysis should lead to the suspicion of C. perfringens infection. Here we review twenty cases published since 1990 and their clinical features are discussed. The importance of ”an aggressive treatment policy” with multidisciplinary team approach is emphasized. PMID:22993668

Law, Siu-Tong; Lee, Ming Kai

2012-01-01

338

Extragingival pyogenic granuloma associated with medication: Report of an unusual case.  

PubMed

Pyogenic granuloma (PG) is a well-known benign non-neoplastic overgrowth. It is a response to mild irritation and might be related to hormonal factors and certain kinds of drugs. PG preferentially affects the gingiva, but can be found extragingivally with varying clinical features. The most common treatment is surgical excision. This article describes a case of extragingival PG occurring on the tongue with unusual presentation, with emphasis on non-surgical treatment. Since surgical management had not been successful, an alternative approach was taken. We illustrated how the lesion was successfully treated with a series of intralesional corticosteroid injections. PMID:25097653

Ghalayani, Parichehr; Hajisadeghi, Samira; Babadi, Fatemeh

2014-05-01

339

Extragingival pyogenic granuloma associated with medication: Report of an unusual case  

PubMed Central

Pyogenic granuloma (PG) is a well-known benign non-neoplastic overgrowth. It is a response to mild irritation and might be related to hormonal factors and certain kinds of drugs. PG preferentially affects the gingiva, but can be found extragingivally with varying clinical features. The most common treatment is surgical excision. This article describes a case of extragingival PG occurring on the tongue with unusual presentation, with emphasis on non-surgical treatment. Since surgical management had not been successful, an alternative approach was taken. We illustrated how the lesion was successfully treated with a series of intralesional corticosteroid injections. PMID:25097653

Ghalayani, Parichehr; Hajisadeghi, Samira; Babadi, Fatemeh

2014-01-01

340

ARTICLE doi:10.1038/nature09967 Streptococcal M1 protein constructs a  

E-print Network

invasive strain of group A Streptococcus, is sufficient to induce toxic-shock-like vascular leakage toxic shock. The M protein1 is the major surface-associated virulence factor of Streptococcus pyogenes invasive diseases with high mortality rates (,30%), such as streptococcal toxic shock syndrome (STSS)2

Nizet, Victor

341

Evaluation of Melia azedarach Extracts Against Streptococcus mutans.  

PubMed

Although the incidence of caries worldwide has declined in recent years, it is necessary to search for new means to overcome this disease and its microbiological agents. Phytochemistry can become an effective alternative to antibiotics, offering a promising strategy in the prevention and therapy of dental caries. This study aimed to evaluate in vitro the bactericide activity of a bioactive phytocomponent from Melia azedarach against Streptococcus mutans. The crude extract (CEx) from leaves and stem barks of M. azedarach in chloroform, petroleum ether, acetate ethyl, butanol, and aqueous fractions was evaluated using seven different concentrations. Disk diffusion and minimum inhibitory concentration assays were used to evaluate the antibacterial activity. 0.12% chlorhexidine was used as a positive control. The CEx and the petroleum ether fraction from M. azedarach showed significant antibacterial activity against S. mutans, confirming its antibiotic potential. PMID:25069066

Della Bona, Alvaro; Nedel, Fernanda

2015-02-01

342

Streptolysin O and NAD-Glycohydrolase Prevent Phagolysosome Acidification and Promote Group A Streptococcus Survival in Macrophages  

PubMed Central

ABSTRACT Group A Streptococcus (GAS, Streptococcus pyogenes) is an ongoing threat to human health as the agent of streptococcal pharyngitis, skin and soft tissue infections, and life-threatening conditions such as necrotizing fasciitis and streptococcal toxic shock syndrome. In animal models of infection, macrophages have been shown to contribute to host defense against GAS infection. However, as GAS can resist killing by macrophages in vitro and induce macrophage cell death, it has been suggested that GAS intracellular survival in macrophages may enable persistent infection. Using isogenic mutants, we now show that the GAS pore-forming toxin streptolysin O (SLO) and its cotoxin NAD-glycohydrolase (NADase) mediate GAS intracellular survival and cytotoxicity for macrophages. Unexpectedly, the two toxins did not inhibit fusion of GAS-containing phagosomes with lysosomes but rather prevented phagolysosome acidification. SLO served two essential functions, poration of the phagolysosomal membrane and translocation of NADase into the macrophage cytosol, both of which were necessary for maximal GAS intracellular survival. Whereas NADase delivery to epithelial cells is mediated by SLO secreted from GAS bound to the cell surface, in macrophages, the source of SLO and NADase is GAS contained within phagolysosomes. We found that transfer of NADase from the phagolysosome to the macrophage cytosol occurs not by simple diffusion through SLO pores but rather by a specific translocation mechanism that requires the N-terminal translocation domain of NADase. These results illuminate the mechanisms through which SLO and NADase enable GAS to defeat macrophage-mediated killing and provide new insight into the virulence of a major human pathogen. PMID:25227466

Bastiat-Sempe, Benedicte; Love, John F.; Lomayesva, Natalie

2014-01-01

343

Group A Streptococcus Adheres to Pharyngeal Epithelial Cells with Salivary Proline-rich Proteins via GrpE Chaperone Protein*  

PubMed Central

Group A Streptococcus pyogenes (GAS) is an important human pathogen that frequently causes pharyngitis. GAS organisms can adhere to and invade pharyngeal epithelial cells, which are overlaid by salivary components. However, the role of salivary components in GAS adhesion to pharyngeal cells has not been reported precisely. We collected human saliva and purified various salivary components, including proline-rich protein (PRP), statherin, and amylase, and performed invasion assays. The GAS-HEp-2 association ratio (invasion/adhesion ratio) and invasion ratio of GAS were increased significantly with whole human saliva and PRP, while the anti-PRP antibody inhibited the latter. GAS strain NY-5, which lacks M and F proteins on the cell surface, was promoted to cohere with HEp-2 cells by whole human saliva and PRP. The 28-kDa protein of GAS bound to PRP and was identified as GrpE, a chaperone protein, whereas the N-terminal of GrpE was found to bind to PRP. A GrpE-deficient mutant of GAS strain B514Sm, TR-45, exhibited a reduced ability to adhere to and invade HEp-2 cells. Microscopic observations showed the GrpE was mainly expressed on the surface of the cell division site of GAS. Furthermore, GrpE-deficient mutants of GAS and Streptococcus pneumoniae showed an elongated morphology as compared with the wild type. Taken together, this is the first study to show an interaction between salivary PRP and GAS GrpE, which plays an important role in GAS infection on the pharynx, whereas the expression of GrpE on the surface of GAS helps to maintain morphology. PMID:22566698

Murakami, Jumpei; Terao, Yutaka; Morisaki, Ichijiro; Hamada, Shigeyuki; Kawabata, Shigetada

2012-01-01

344

Streptococcus pneumoniae Invades Erythrocytes and Utilizes Them to Evade Human Innate Immunity  

E-print Network

Streptococcus pneumoniae Invades Erythrocytes and Utilizes Them to Evade Human Innate Immunity Hospital for Infection Control, Nagoya University Hospital, Nagoya, Aichi, Japan Abstract Streptococcus. (2013) Streptococcus pneumoniae Invades Erythrocytes and Utilizes Them to Evade Human Innate Immunity

Nizet, Victor

345

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Exclusive License: P4 Peptide From Streptococcus Pneumoniae AGENCY: Technology Transfer...vaccine conjugate for prevention of Streptococcus pneumonia infection in humans...entitled ``Functional Epitopes of Streptococcus Pneumoniae PsaA Antigen and Uses...

2012-05-02

346

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

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs...Serological Reagents § 866.3720 Streptococcus spp. exo-enzyme reagents. (a) Identification. Streptococcus...

2013-04-01

347

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

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs...Serological Reagents § 866.3720 Streptococcus spp. exo-enzyme reagents. (a) Identification. Streptococcus...

2014-04-01

348

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

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs...Serological Reagents § 866.3720 Streptococcus spp. exo-enzyme reagents. (a) Identification. Streptococcus...

2010-04-01

349

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

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs...Serological Reagents § 866.3720 Streptococcus spp. exo-enzyme reagents. (a) Identification. Streptococcus...

2011-04-01

350

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

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs...Serological Reagents § 866.3720 Streptococcus spp. exo-enzyme reagents. (a) Identification. Streptococcus...

2012-04-01

351

Host Responses to Group A Streptococcus: Cell Death and Inflammation  

PubMed Central

Infections caused by group A Streptococcus (GAS) are characterized by robust inflammatory responses and can rapidly lead to life-threatening disease manifestations. However, host mechanisms that respond to GAS, which may influence disease pathology, are understudied. Recent works indicate that GAS infection is recognized by multiple extracellular and intracellular receptors and activates cell signalling via discrete pathways. Host leukocyte receptor binding to GAS-derived products mediates release of inflammatory mediators associated with severe GAS disease. GAS induces divergent phagocyte programmed cell death responses and has inflammatory implications. Epithelial cell apoptotic and autophagic components are mobilized by GAS infection, but can be subverted to ensure bacterial survival. Examination of host interactions with GAS and consequences of GAS infection in the context of cellular receptors responsible for GAS recognition, inflammatory mediator responses, and cell death mechanisms, highlights potential avenues for diagnostic and therapeutic intervention. Understanding the molecular and cellular basis of host symptoms during severe GAS disease will assist the development of improved treatment regimens for this formidable pathogen. PMID:25165887

Tsatsaronis, James A.; Walker, Mark J.; Sanderson-Smith, Martina L.

2014-01-01

352

Propionibacterium acnes and Staphylococcus lugdunensis Cause Pyogenic Osteomyelitis in an Intramedullary Nail Model in Rabbits  

PubMed Central

Propionibacterium acnes and coagulase-negative staphylococci (CoNS) are opportunistic pathogens implicated in prosthetic joint and fracture fixation device-related infections. The purpose of this study was to determine whether P. acnes and the CoNS species Staphylococcus lugdunensis, isolated from an “aseptically failed” prosthetic hip joint and a united intramedullary nail-fixed tibial fracture, respectively, could cause osteomyelitis in an established implant-related osteomyelitis model in rabbits in the absence of wear debris from the implant material. The histological features of P. acnes infection in the in vivo rabbit model were consistent with localized pyogenic osteomyelitis, and a biofilm was present on all explanted intramedullary (IM) nails. The animals displayed no outward signs of infection, such as swelling, lameness, weight loss, or elevated white blood cell count. In contrast, infection with S. lugdunensis resulted in histological features consistent with both pyogenic osteomyelitis and septic arthritis, and all S. lugdunensis-infected animals displayed weight loss and an elevated white blood cell count despite biofilm detection in only two out of six rabbits. The differences in the histological and bacteriological profiles of the two species in this rabbit model of infection are reflective of their different clinical presentations: low-grade infection in the case of P. acnes and acute infection for S. lugdunensis. These results are especially important in light of the growing recognition of chronic P. acnes biofilm infections in prosthetic joint failure and nonunion of fracture fixations, which may be currently reported as “aseptic” failure. PMID:24599975

Gahukamble, Abhay Deodas; McDowell, Andrew; Post, Virginia; Salavarrieta Varela, Julian; Rochford, Edward Thomas James; Richards, Robert Geoff; Patrick, Sheila

2014-01-01

353

M Protein of the Group A Streptococcus Binds to the Seventh Short Consensus Repeat of Human Complement Factor H  

PubMed Central

Streptococcus pyogenes evades complement by binding the complement-regulatory protein factor H (fH) via the central conserved C-repeat region of M protein. However, the corresponding binding region within fH has not previously been precisely localized. fH is composed of 20 conserved modules called short consensus repeats (SCRs), each of which contains approximately 60 amino acids. A series of fH truncated and deletion mutants were prepared, and their interaction with M6 protein was examined. The M protein binding site was initially localized to SCRs 6 to 15 as demonstrated by ligand dot blotting, chemical cross-linking, and enzyme-linked immunosorbent assay. SCR 7 was then shown to contain the M protein binding site, as a construct consisting of the first seven SCRs bound M protein but a construct containing the first six SCRs did not bind. In addition, deletion of SCR 7 from full-length fH abolished binding to M protein. SCR 7 is known to contain a heparin binding domain, and binding of fH to M6 protein was almost totally inhibited in the presence of 400 U of heparin per ml. These results localize the M6 protein binding site of fH to SCR 7 and indicate that it is in close proximity to the heparin binding site. PMID:9529063

Blackmore, Timothy K.; Fischetti, Vincent A.; Sadlon, Tania A.; Ward, Helena M.; Gordon, David L.

1998-01-01

354

Huge pyogenic cervical cyst with endometriosis, developing 13 years after myomectomy at the lower uterine segment: a case report  

PubMed Central

Background Surgical site infections are potential complications following open myomectomy. These infections usually develop immediately after the surgery, and are most often located in the myometrium. Pyogenic cervical cysts are rare and have not been previously reported to occur at the site of myomectomy. Case presentation A 41-year-old nulligravida Japanese woman was referred to our hospital with a large cervical cyst (>15 cm in diameter). She had undergone a myomectomy 13 years previously, and the surgical site had extended to the endocervical gland. Standard blood tests did not show any evidence of inflammation. The patient underwent a total abdominal hysterectomy, which revealed that the cyst contained multiple components, including Escherichia coli, old blood, and evidence of endometriosis. A pathological review did not show malignant cells within the cyst. The pyogenic cyst originated from the upper anterior cervix, which was one of the sites involved in the previous myomectomy. Conclusion We reported a huge pyogenic cervical cyst exhibiting signs of endometriosis, in the vicinity of the uterine scar from the open myomectomy. The previous surgery and endometriosis might have contributed to the formation of this rare pyogenic cyst. PMID:25186472

2014-01-01

355

Energy condition affects fermentation rate of Streptococcus bovis without changing fermentation pattern  

E-print Network

Energy condition affects fermentation rate of Streptococcus bovis without changing fermentation fermentation patterns are unclear. Streptococcus bovis is a major ruminal bacteria, produces acetate, lactate

Boyer, Edmond

356

Crystal Structure of Streptococcus mutans Pyrophosphatase  

Microsoft Academic Search

Background:Streptococcus mutans pyrophosphatase (Sm-PPase) is a member of a relatively uncommon but widely dispersed sequence family (family II) of inorganic pyrophosphatases. A structure will answer two main questions: is it structurally similar to the family I PPases, and is the mechanism similar?Results: The first family II PPase structure, that of homodimeric Sm-PPase complexed with metal and sulfate ions, has been

Michael C Merckel; Igor P Fabrichniy; Anu Salminen; Nisse Kalkkinen; Alexander A Baykov; Reijo Lahti; Adrian Goldman

2001-01-01

357

Recombination-deficient mutant of Streptococcus faecalis  

SciTech Connect

An ultraviolet radiation-sensitive derivative of Streptococcus faecalis strain JH2-2 was isolated and found to be deficient in recombination, using a plasmid-plasmid recombination system. The strain was sensitive to chemical agents which interact with deoxyribonucleic acid and also underwent deoxyribonucleic acid degradation after ultraviolet irradiation. Thus, the mutant has properties similar to those of recA strains of Escherichia coli.

Yagi, Y.; Clewell, D.B.

1980-08-01

358

A selective medium for Streptococcus mutans  

Microsoft Academic Search

Summary-A selective medium was developed for the isolation of Streptococcus mutans from human dental plaque. Mitis-salivarius agar was modified by adding 0.2 units\\/ml bacitracin and by increasing the sucrose concentration to 20 per cent. At these concen- trations, the selective agents allowed the undiminished recovery of Strep. mutans with maximum inhibition of the balance of the streptococcal flora normally encountered

Olga G. Gold; H. V. Jordan; J. van Houte

1973-01-01

359

Transposable multiple antibiotic resistance in Streptococcus pneumoniae  

Microsoft Academic Search

A mobile genetic element, designated Tn1545, was detected in the chromosome of Streptococcus pneumoniae BM4200, a clinical isolate multiply resistant to antibiotics. The 25.3 kb element conferred resistance to kanamycin and structurally related aminoglycosides by synthesis of a 3'-aminoglycoside phosphotranferase type III (aphA-3), to macrolide-lincosamide-streptogramin B-type antibiotics (ermAM), and to tetracycline (tetM). Tn1545 was self-transferable to a recombination deficient S.

Patrice Courvalin; Cécile Carlier

1986-01-01

360

Genetic analysis of Streptococcus agalactiae strains isolated from neonates and their mothers.  

PubMed

Streptococcus agalactiae or group B streptococcus (GBS) is the most common cause of neonatal sepsis and meningitis in neonates. One of the major questions is whether the GBS strains able to cause neonatal invasive disease have peculiar genetic features. A collection of S. agalactiae strains, isolated from cervix, vagina and rectum of 10 mothers and from throat, ear and umbilicus of their newborns was genetically characterized by pulsed-field gel electrophoresis (PFGE). This study demonstrated that the strains isolated from each mother and her child were all genetically identical but that the strains from the 10 mother/child pairs mutually were genetically heterogeneous and 10 different PFGE patterns were found. Although it has been suggested that PFGE would be able to identify virulence traits to direct decisions in antibiotic management, the heterogeneous feature of GBS strains does not support broad application. PMID:12727374

Melchers, Willem J G; Bakkers, Judith M J E; Toonen, Marga; van Kuppeveld, Frank J M; Trijbels, Monique; Hoogkamp-Korstanje, Jacomina A A

2003-05-15

361

Accidental fall due to abnormal behavior after experiencing a Streptococcus pyogenes infection: febrile delirium or pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection?  

PubMed

An 11-year-old boy with a high fever (39.4 degrees C) presented at a local medical institution. His condition was diagnosed as hemolytic streptococcal infection, and he was prescribed an antibiotic. After returning home, he took a dose of his medication and rested; however, he suddenly began to run around while yelling incomprehensible words. He ran up to his room on the second floor and fell from the second floor window down to the ground. He lost consciousness and was transferred to our department. His history included being born as a twin with a low birth weight and pneumonia at 1 year of age. He regained consciousness on the seventh hospital day and was discharged without any neurological abnormality on the 14th day. His abnormal behavior might have resulted from febrile delirium or an unusual expression of pediatric autoimmune neuropsychiatric disorder associated with a streptococcal infection. PMID:19687712

Yanagawa, Youichi; Kaneko, Naoyuki; Higashidate, Seiki; Matsumoto, Hiroshi

2009-08-01

362

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2010-09-03

363

Streptococcus iniae in Gilthead Seabream (Sparus aurata, L.) and Red Porgy (Pagrus pagrus, L.): Ultrastructural Analysis.  

PubMed

Streptococcosis caused by Streptococcus iniae has become one of the most serious marine and freshwater aquatic diseases in the past decade, causing large losses in farmed and wild fish worldwide. In this study, we performed an ultrastructural study of major lesions in gilthead seabream Sparus aurata and red porgy Pagrus pagrus experimentally infected with the S. iniae IUSA-1 strain, isolated in a natural outbreak in Spain in the mentioned species. The transmission electron micrographs revealed the resistance of this pathogen inside the phagosome, indicating that the macrophage may provide a significant bacterial reservoir for continuing infection, disease dissemination, and tissue injury by crossing the blood-brain barrier. PMID:24496225

Aamri, F El; Caballero, M J; Real, F; Acosta, F; Déniz, S; Román, L; Padilla, D

2015-01-01

364

Emergence of novel Streptococcus iniae exopolysaccharide-producing strains following vaccination with nonproducing strains.  

PubMed

Streptococcus iniae is a major pathogen of fish, producing fatal disease among fish species living in very diverse environments. Recently, reoccurrences of disease outbreaks were recorded in rainbow trout (Oncorhynchus mykiss, Walbaum) farms where the entire fish population was routinely vaccinated. New strains are distinguished from previous strains by their ability to produce large amounts of extracellular polysaccharide that is released into the medium. Present findings indicate that the extracellular polysaccharide is a major antigenic factor, suggesting an evolutionary selection of strains capable of extracellular polysaccharide production. PMID:18806000

Eyngor, Marina; Tekoah, Yoram; Shapira, Roni; Hurvitz, Avshalom; Zlotkin, Amir; Lublin, Avishay; Eldar, Avi

2008-11-01

365

Emergence of Novel Streptococcus iniae Exopolysaccharide-Producing Strains following Vaccination with Nonproducing Strains ? †  

PubMed Central

Streptococcus iniae is a major pathogen of fish, producing fatal disease among fish species living in very diverse environments. Recently, reoccurrences of disease outbreaks were recorded in rainbow trout (Oncorhynchus mykiss, Walbaum) farms where the entire fish population was routinely vaccinated. New strains are distinguished from previous strains by their ability to produce large amounts of extracellular polysaccharide that is released into the medium. Present findings indicate that the extracellular polysaccharide is a major antigenic factor, suggesting an evolutionary selection of strains capable of extracellular polysaccharide production. PMID:18806000

Eyngor, Marina; Tekoah, Yoram; Shapira, Roni; Hurvitz, Avshalom; Zlotkin, Amir; Lublin, Avishay; Eldar, Avi

2008-01-01

366

A naturally occurring single amino Acid replacement in multiple gene regulator of group a streptococcus significantly increases virulence.  

PubMed

Single-nucleotide polymorphisms (SNPs) are the most common source of genetic variation within a species; however, few investigations demonstrate how naturally occurring SNPs may increase strain virulence. We recently used group A Streptococcus as a model pathogen to study bacteria strain genotype-patient disease phenotype relationships. Whole-genome sequencing of approximately 800 serotype M59 group A Streptococcus strains, recovered during an outbreak of severe invasive infections across North America, identified a disproportionate number of SNPs in the gene encoding multiple gene regulator of group A Streptococcus (mga). Herein, we report results of studies designed to test the hypothesis that the most commonly occurring SNP, encoding a replacement of arginine for histidine at codon 201 of Mga (H201R), significantly increases virulence. Whole transcriptome analysis revealed that the H201R replacement significantly increased expression of mga and 54 other genes, including many proven virulence factors. Compared to the wild-type strain, a H201R isogenic mutant strain caused significantly larger skin lesions in mice. Serial quantitative bacterial culture and noninvasive magnetic resonance imaging also demonstrated that the isogenic H201R strain was significantly more virulent in a nonhuman primate model of joint infection. These findings show that the H201R replacement in Mga increases the virulence of M59 group A Streptococcus and provide new insight to how a naturally occurring SNP in bacteria contributes to human disease phenotypes. PMID:25476528

Sanson, Misu; O'Neill, Brian E; Kachroo, Priyanka; Anderson, Jeff R; Flores, Anthony R; Valson, Chandni; Cantu, Concepcion C; Makthal, Nishanth; Karmonik, Christof; Fittipaldi, Nahuel; Kumaraswami, Muthiah; Musser, James M; Olsen, Randall J

2015-02-01

367

Structural Differences between the Streptococcus agalactiae Housekeeping and Pilus-Specific Sortases: SrtA and SrtC1  

SciTech Connect

The assembly of pili on the cell wall of Gram-positive bacteria requires transpeptidase enzymes called sortases. In Streptococcus agalactiae, the PI-1 pilus island of strain 2603V/R encodes two pilus-specific sortases (SrtC1 and SrtC2) and three pilins (GBS80, GBS52 and GBS104). Although either pilus-specific sortase is sufficient for the polymerization of the major pilin, GBS80, incorporation of the minor pilins GBS52 and GBS104 into the pilus structure requires SrtC1 and SrtC2, respectively. The S. agalactiae housekeeping sortase, SrtA, whose gene is present at a different location and does not catalyze pilus polymerization, was shown to be involved in cell wall anchoring of pilus polymers. To understand the structural basis of sortases involved in such diverse functions, we determined the crystal structures of S. agalactiae SrtC1 and SrtA. Both enzymes are made of an eight-stranded beta-barrel core with variations in their active site architecture. SrtA exhibits a catalytic triad arrangement similar to that in Streptococcus pyogenes SrtA but different from that in Staphylococcus aureus SrtA. In contrast, the SrtC1 enzyme contains an N-terminal helical domain and a 'lid' in its putative active site, which is similar to that seen in Streptococcus pneumoniae pilus-specific sortases, although with subtle differences in positioning and composition. To understand the effect of such differences on substrate recognition, we have also determined the crystal structure of a SrtC1 mutant, in which the conserved DP(W/F/Y) motif was replaced with the sorting signal motif of GBS80, IPNTG. By comparing the structures of WT wild type SrtA and SrtC1 and the 'lid' mutant of SrtC1, we propose that structural elements within the active site and the lid may be important for defining the role of specific sortase in pili biogenesis.

Khare, B.; Krishnan, V.; Rajashankar, K.R.; I-Hsiu, H.; Xin, M.; Ton-That, H.; Narayana, S.V. (Texas-HSC); (Cornell); (UAB)

2011-10-21

368

Pyogenic granuloma near the midline of the oral cavity: A series of case reports.  

PubMed

Pyogenic granuloma (PyG) is a common cause of swelling in the oral cavity during pregnancy and also as an exaggerated response to any minor trauma. The condition is frequently associated with periodontal pain and discomfort, in some cases interfering with mastication and creating esthetic problems. Six patients reported to the Department of Periodontics with gingival overgrowth in the lower anteriors. After recording the details of the patients' oral hygiene status, all the patients were provided initial therapy with scaling and were prescribed analgesics for the reduction of pain and discomfort. After 1 week, surgical excision of the overgrowth was performed and sent for histopathological analysis. The histopathological report is suggestive of PyG. PMID:24872636

Adusumilli, Srikanth; Yalamanchili, Pallavi Samatha; Manthena, Sathish

2014-03-01

369

Pyogenic granuloma near the midline of the oral cavity: A series of case reports  

PubMed Central

Pyogenic granuloma (PyG) is a common cause of swelling in the oral cavity during pregnancy and also as an exaggerated response to any minor trauma. The condition is frequently associated with periodontal pain and discomfort, in some cases interfering with mastication and creating esthetic problems. Six patients reported to the Department of Periodontics with gingival overgrowth in the lower anteriors. After recording the details of the patients’ oral hygiene status, all the patients were provided initial therapy with scaling and were prescribed analgesics for the reduction of pain and discomfort. After 1 week, surgical excision of the overgrowth was performed and sent for histopathological analysis. The histopathological report is suggestive of PyG. PMID:24872636

Adusumilli, Srikanth; Yalamanchili, Pallavi Samatha; Manthena, Sathish

2014-01-01

370

[Problems of bacteriologic diagnosis and aimed antibiotic therapy in pyogenic maxillofacial infections].  

PubMed

Bacteriologic analysis of pathogens from pyogenic infections of the jaw in 71 patients revealed that bacteria normally found in the buccal cavity predominated in 86% of the specimens. Considering the fact that no pathogens could be identified in 7% of the specimens, this then means that pathogens were only found in 7% of the specimens. Six to 12 strains were usually isolated in the mixed bacteria population of the buccal cavity. A total of 430 strains of bacteria were cultured and tested for their response to 20 common antibiotic preparations. We were able to confirm the high effectiveness of penicillin and/or broad spectrum penicillin 92% of the cases (8600 determinations of resistance). Tetracycline was effective in 89% of the cases; trimethoprim sulfamethoxazole, in 83%. The effectiveness of newer, more expensive, antibiotic preparations was not significantly better than that of pencillin. Administration of such antibiotic preparations therefore should be limited to problematic pathogens. PMID:367753

Geiger, S A; Gräf, W

1978-11-01

371

Pyogenic granuloma associated with periodontal abscess and bone loss - A rare case report  

PubMed Central

A diverse group of the pathologic process can produce the enlargement of soft tissues in the oral cavity and often present a diagnostic challenge. This soft tissue enlargement may represent a variation of the normal anatomic structure, inflammatory reaction, cyst, neoplasm, and developmental anomalies. A group of reactive hyperplasias, which develop in response to chronic recurring tissue injury that stimulates an excessive tissue repair response. The pyogenic granuloma (PG) is a reactive enlargement that is an inflammatory response to local irritation such as calculus, a fractured tooth, rough dental restoration, and foreign materials or hormonal (pregnancy tumor) and rarely associated with bone loss. This paper presents a rare case of PG associated with periodontal abscess and bone loss in a 30-year-old male. PMID:22090773

Panseriya, Bhrugesh J.; Hungund, Shital

2011-01-01

372

Streptococcus raffinozactis Orla- Jensen and Hansen, a Group N Streptococcus Found in Raw Milk  

Microsoft Academic Search

The properties of the lactate dehydrogenases, percent guanine plus cytosine in the deoxyribonucleic acid (DNA), and DNA\\/DNA hybridization studies have shown that three strains of group N streptococci do not belong to either Strep- tococcus Zactis or Streptococcus cremoris. The biochemical properties of the three strains were published about 25 years ago, and at that time the strains were not

ELLEN I. GARVIE

1978-01-01

373

[Serotype diversity and antimicrobial resistance of Streptococcus pneumoniae].  

PubMed

The pneumococcus (Streptococcus pneumoniae) is a common bacterial pathogen responsible for various infections, especially in children below 5 years of age. The severity of pneumococcal infections varies from self-limiting mucosal infections, including acute otitis media, sinusitis, and noninvasive pneumonia, to life-threatening invasive disease like bacteremia and meningitis. A high incidence of pneumococcal infections is combined with a constantly growing antibiotic resistance of this pathogen. The growing resistance is thought to be associated with misuse of antibiotics and emerging of resistant clones that may spread throughout the entire population. Pneumococcal polysaccharide conjugate vaccines (PCV) contain an assortment of pneumococcal capsular polysaccharides (from 7 to 13) that produce serotype-specific protective antibodies. Since early 2000's, the introduction of PCV into national immunization programs has been shown to substantially decrease the incidence of invasive pneumococcal disease and pneumococcal carriage associated with vaccine-type pneumococci in many countries. In 2014, PCV vaccination was included in the Russian national calendar of prophylactic vaccination. The present article reviews the current literature on serotype prevalence, antibiotic susceptibility, and PCV effect on the evolution of pneumococcus. PMID:25563003

2014-01-01

374

Mosaic Genes and Mosaic Chromosomes: Intra- and Interspecies Genomic Variation of Streptococcus pneumoniae  

PubMed Central

Streptococcus pneumoniae remains a major causative agent of serious human diseases. The worldwide increase of antibiotic resistant strains revealed the importance of horizontal gene transfer in this pathogen, a scenario that results in the modulation of the species-specific gene pool. We investigated genomic variation in 20 S. pneumoniae isolates representing major antibiotic-resistant clones and 10 different capsular serotypes. Variation was scored as decreased hybridization signals visualized on a high-density oligonucleotide array representing 1,968 genes of the type 4 reference strain KNR.7/87. Up to 10% of the genes appeared altered between individual isolates and the reference strain; variability within clones was below 2.1%. Ten gene clusters covering 160 kb account for half of the variable genes. Most of them are associated with transposases and are assumed to be part of a flexible gene pool within the bacterial population; other variable loci include mosaic genes encoding antibiotic resistance determinants and gene clusters related to bacteriocin production. Genomic comparison between S. pneumoniae and commensal Streptococcus mitis and Streptococcus oralis strains indicates distinct antigenic profiles and suggests a smooth transition between these species, supporting the validity of the microarray system as an epidemiological and diagnostic tool. PMID:11254610

Hakenbeck, Regine; Balmelle, Nadège; Weber, Beate; Gardès, Christophe; Keck, Wolfgang; de Saizieu, Antoine

2001-01-01

375

Longitudinal study of dental caries incidence associated with Streptococcus mutans and Streptococcus sobrinus in pre-school children  

Microsoft Academic Search

Streptococcus mutans and Streptococcus sobrinus are known to be associated with the development of dental caries. In this study these bacteria were detected in pre-school children (each with primary dentition, age range 3-5 years, n ¼ 60) using a PCR method, and then their presence was compared with the incidence of dental caries over a 1-year period. Plaque samples were

Mitsugi Okada; Yoshiko Soda; Fumiko Hayashi; Takako Doi; Junji Suzuki; Kazuo Miura; Katsuyuki Kozai

2005-01-01

376

Streptococcus iniae sp. nov. , a Beta-Hemolytic Streptococcus Isolated from an Amazon Freshwater Dolphin, Inia geo ffrens is  

Microsoft Academic Search

Evidence is presented for the recognition of a new species of Streptococcus isolated from abscess foci in an Amazon freshwater dolphin, Inia geoffrensis . The organism appears to be immunologically distinct from members of the recognized Lancefield groups of streptococci. Antigens prepared by five different extraction procedures do not react with antisera to Streptococcus groups A to U, whereas antisera

GERALD B. PIER; STEWART H. MADIN

377

Discovery and characterization of sialic acid O-acetylation in group B Streptococcus  

E-print Network

Discovery and characterization of sialic acid O-acetylation in group B Streptococcus Amanda L, New York, NY, and approved June 21, 2004 (received for review April 28, 2004) Group B Streptococcus. Streptococcus agalactiae polysaccharide capsule Neu5Ac Group B Streptococcus (GBS) is the leading cause

Nizet, Victor

378

Ferrous iron transport in Streptococcus mutans  

SciTech Connect

Radioiron uptake from /sup 59/FeCl/sub 3/ by Streptococcus mutans OMZ176 was increased by anaerobiosis, sodium ascorbate, and phenazine methosulfate (PMS), although there was a 10-min lag before PMS stimulation was evident. The reductant ascorbate may have provided ferrous iron. The PMS was reduced by the cells, and the reduced PMS then may have generated ferrous iron for transport; reduced PMS also may have depleted dissolved oxygen. It was concluded that S. mutans transports only ferrous iron, utilizing reductants furnished by glucose metabolism to reduce iron prior to its uptake.

Evans, S.L.; Arcenaeux, J.E.L.; Byers, B.R.; Martin, M.E.; Aranha, H.

1986-12-01

379

Streptococcus pluranimalium: A novel human pathogen?  

PubMed Central

INTRODUCTION We present the first case of a subdural empyema caused by Streptococcus pluranimalium, in a healthy adolescent male as a possible complication of subclinical frontal sinusitis. Clinical features, diagnostic approach and management of subdural empyema are discussed. PRESENTATION OF CASE A 17-year-old male with a 2 day history of headache and nausea was referred to our Emergency Department (ED) as a case of possible meningitis. He was afebrile, lethargic and drowsy with significant neck stiffness on examination. Computerized tomography (CT) revealed a large frontotemporoparietal subdural fluid collection with significant midline shift. Subsequent contrast-enhanced CT established the presence of intracranial empyema; the patient underwent immediate burr-hole evacuation of the pus and received 7 weeks of intravenous antibiotics, recovering with no residual neurological deficit. DISCUSSION The diagnosis of subdural empyema as a complication of asymptomatic sinusitis in an immunocompetent patient with no history of fever or upper respiratory symptoms was unanticipated. Furthermore, the organism Streptococcus pluranimalium that was cultured from the pus has only been documented twice previously in medical literature to cause infection in humans, as it is primarily a pathogen responsible for infection in bovine and avian species. CONCLUSION Subdural empyema represents a neurosurgical emergency and if left untreated is invariably fatal. Rapid diagnosis, surgical intervention and intensive antibiotic therapy improve both morbidity and mortality. PMID:25437686

Aryasinghe, Lasanthi; Sabbar, Saweera; Kazim, Yasmin; Awan, Liaqat Mahmood; Khan, Hammad Khan Nadir

2014-01-01

380

Fatal outcome after insufficient spine fixation for pyogenic thoracic spondylodiscitis: an imperative for 360° fusion of the infected spine  

Microsoft Academic Search

BACKGROUND: Pyogenic spondylodiscitis represents a potentially life-threatening condition. Due to the low incidence, evidence-based surgical recommendations in the literature are equivocal, and the treatment modalities remain controversial. CASE PRESENTATION: A 59 year-old patient presented with a history of thoracic spondylodiscitis resistant to antibiotic treatment for 6 weeks, progressive severe back pain, and a new onset of bilateral lower extremity weakness.

Michael A Flierl; Kathryn M Beauchamp; Gene E Bolles; Ernest E Moore; Philip F Stahel

2009-01-01

381

The Arcanobacterium (Actinomyces) pyogenes hemolysin, pyolysin, is a novel member of the thiol-activated cytolysin family.  

PubMed Central

Arcanobacterium (Actinomyces) pyogenes, an animal pathogen, produces a hemolytic exotoxin, pyolysin (PLO). The gene encoding PLO was cloned, and sequence analysis revealed an open reading frame of 1,605 bp encoding a protein of 57.9 kDa. PLO has 30 to 40% identity with the thiol-activated cytolysins (TACYs) of a number of gram-positive bacteria. The activity of PLO was found to be very similar to those of other TACYs, except that it was not thiol activated. The highly conserved TACY undecapeptide is divergent in PLO; in particular, the cysteine residue required for thiol activation has been replaced with alanine. However, mutagenesis of the alanine residue to cysteine did not confer thiol activation on PLO, suggesting a conformational difference in the undecapeptide region of this toxin. Specific antibodies against purified, recombinant PLO completely neutralized the hemolytic activity of A. pyogenes, suggesting that this organism produces a single hemolysin. Furthermore, these antibodies could passively protect mice against lethal challenge with A. pyogenes, suggesting that like other TACYs PLO is an important virulence factor in the pathogenesis of this organism. PMID:9324258

Billington, S J; Jost, B H; Cuevas, W A; Bright, K R; Songer, J G

1997-01-01

382

An Arcanobacterium (Actinomyces) pyogenes Mutant Deficient in Production of the Pore-Forming Cytolysin Pyolysin Has Reduced Virulence  

PubMed Central

Pyolysin (PLO), the hemolytic exotoxin expressed by Arcanobacterium (Actinomyces) pyogenes, is a member of the thiol-activated cytolysin family of bacterial toxins. Insertional inactivation of the plo gene results in loss of expression of PLO with a concomitant loss in hemolytic activity. The plo mutant, PLO-1, has an approximately 1.8-log10 reduction in the 50% infectious dose compared to that for wild-type A. pyogenes in a mouse intraperitoneal infection model. Studies involving cochallenge of wild-type and PLO-1 bacteria resulted in recovery of similar numbers of both strains, suggesting that PLO production is required for survival in vivo. Recombinant, His-tagged PLO (His-PLO) is cytotoxic for mouse peritoneal macrophages and J774 cells in a dose-dependent manner. Protection against challenge with A. pyogenes could be afforded by vaccination with formalin-inactivated His-PLO, suggesting that PLO is a host-protective antigen, as well as a virulence determinant. PMID:10085010

Jost, B. H.; Songer, J. G.; Billington, S. J.

1999-01-01

383

Sequencing and Comparative Genome Analysis of Two Pathogenic Streptococcus gallolyticus Subspecies: Genome Plasticity, Adaptation and Virulence  

PubMed Central

Streptococcus gallolyticus infections in humans are often associated with bacteremia, infective endocarditis and colon cancers. The disease manifestations are different depending on the subspecies of S. gallolyticus causing the infection. Here, we present the complete genomes of S. gallolyticus ATCC 43143 (biotype I) and S. pasteurianus ATCC 43144 (biotype II.2). The genomic differences between the two biotypes were characterized with comparative genomic analyses. The chromosome of ATCC 43143 and ATCC 43144 are 2,36 and 2,10 Mb in length and encode 2246 and 1869 CDS respectively. The organization and genomic contents of both genomes were most similar to the recently published S. gallolyticus UCN34, where 2073 (92%) and 1607 (86%) of the ATCC 43143 and ATCC 43144 CDS were conserved in UCN34 respectively. There are around 600 CDS conserved in all Streptococcus genomes, indicating the Streptococcus genus has a small core-genome (constitute around 30% of total CDS) and substantial evolutionary plasticity. We identified eight and five regions of genome plasticity in ATCC 43143 and ATCC 43144 respectively. Within these regions, several proteins were recognized to contribute to the fitness and virulence of each of the two subspecies. We have also predicted putative cell-surface associated proteins that could play a role in adherence to host tissues, leading to persistent infections causing sub-acute and chronic diseases in humans. This study showed evidence that the S. gallolyticus still possesses genes making it suitable in a rumen environment, whereas the ability for S. pasteurianus to live in rumen is reduced. The genome heterogeneity and genetic diversity among the two biotypes, especially membrane and lipoproteins, most likely contribute to the differences in the pathogenesis of the two S. gallolyticus biotypes and the type of disease an infected patient eventually develops. PMID:21633709

Teng, Yu-Ting; Wu, Hui-Lun; Liu, Yen-Ming; Wu, Keh-Ming; Chang, Chuan-Hsiung; Hsu, Ming-Ta

2011-01-01

384

Intranasal Vaccination with Pneumococcal Surface Protein A and Interleukin12 Augments Antibody-Mediated Opsonization and Protective Immunity against Streptococcus pneumoniae Infection  

Microsoft Academic Search

Streptococcus pneumoniae is a major pathogen in humans that enters the host primarily through the respiratory tract. Targeting mucosal surfaces directly may therefore be an optimal approach for vaccination to prevent bacterial colonization and invasive disease. We have previously demonstrated the effectiveness of interleukin-12 (IL-12) delivered intransally (i.n.) as an antiviral respiratory adjuvant. In this study, we examined the effects

BERNARD P. ARULANANDAM; JOYCE M. LYNCH; DAVID E. BRILES; SUSAN HOLLINGSHEAD; D. W. Metzger

2001-01-01

385

Genome Sequence of Avery's Virulent Serotype 2 Strain D39 of Streptococcus pneumoniae and Comparison with That of Unencapsulated Laboratory Strain R6  

Microsoft Academic Search

Streptococcus pneumoniae (pneumococcus) is a leading human respiratory pathogen that causes a variety of serious mucosal and invasive diseases. D39 is an historically important serotype 2 strain that was used in experiments by Avery and coworkers to demonstrate that DNA is the genetic material. Although isolated nearly a century ago, D39 remains extremely virulent in murine infection models and is

Joel A. Lanie; Wai-Leung Ng; Krystyna M. Kazmierczak; Tiffany M. Andrzejewski; Tanja M. Davidsen; Kyle J. Wayne; H. Tettelin; J. I. Glass; M. E. Winkler

2007-01-01

386

Characterization of MtsR, a New Metal Regulator in Group A Streptococcus, Involved in Iron Acquisition and Virulence  

Microsoft Academic Search

Group A streptococcus (GAS) is a common pathogen of the human skin and mucosal surfaces capable of producing a variety of diseases. In this study, we investigated regulation of iron uptake in GAS and the role of a putative transcriptional regulator named MtsR (for Mts repressor) with homology to the DtxR family of metal-dependent regulatory proteins. An mtsR mutant was

Christopher S. Bates; Chadia Toukoki; Melody N. Neely; Zehava Eichenbaum

2005-01-01

387

A Natural Inactivating Mutation in the CovS Component of the CovRS Regulatory Operon in a Pattern D Streptococcal pyogenes Strain Influences Virulence-associated Genes*  

PubMed Central

A skin-tropic invasive group A Streptococcus pyogenes (GAS) strain, AP53, contains a natural inactivating mutation in the covS gene (covSM) of the two-component responder (CovR)/sensor (CovS) gene regulatory system. The effects of this mutation on specific GAS virulence determinants have been assessed, with emphasis on expression of the extracellular protease, streptococcal pyrogenic exotoxin B (SpeB), capsular hyaluronic acid, and proteins that allow host plasmin assembly on the bacterial surface, viz. a high affinity plasminogen (Pg)/plasmin receptor, Pg-binding group A streptococcal M protein (PAM), and the human Pg activator streptokinase. To further illuminate mechanisms of the functioning of CovRS in the virulence of AP53, two AP53 isogenic strains were generated, one in which the natural covSM gene was mutated to WT-covS (AP53/covSWT) and a strain that contained an inactivated covR gene (AP53/?covR). Two additional strains that do not contain PAM, viz. WT-NS931 and NS931/covSM, were also employed. SpeB was not measurably expressed in strains containing covRWT/covSM, whereas in strains with natural or engineered covRWT/covSWT, SpeB expression was highly up-regulated. Alternatively, capsule synthesis via the hasABC operon was enhanced in strain AP53/covSM, whereas streptokinase expression was only slightly affected by the covS inactivation. PAM expression was not substantially influenced by the covS mutation, suggesting that covRS had minimal effects on the mga regulon that controls PAM expression. These results demonstrate that a covS inactivation results in virulence gene alterations and also suggest that the CovR phosphorylation needed for gene up- or down-regulation can occur by alternative pathways to CovS kinase. PMID:23316057

Liang, Zhong; Zhang, Yueling; Agrahari, Garima; Chandrahas, Vishwanatha; Glinton, Kristofor; Donahue, Deborah L.; Balsara, Rashna D.; Ploplis, Victoria A.; Castellino, Francis J.

2013-01-01

388

The macrophage chemotactic activity of Streptococcus agalactiae and Streptococcus iniae extracellular products (ECP).  

PubMed

The ability of Streptococcus agalactiae and Streptococcus iniae to attract macrophages of Nile tilapia (Oreochromis niloticus) was investigated. The extracellular products (ECP) from S. agalactiae and S. iniae were tested in vitro for macrophage chemotaxis using blind-well chambers. The macrophages were obtained from the peritoneal cavity 4-5 days after intraperitoneal injection of squalene. Both macrophage chemotactic and chemokinetic activities were demonstrated using the S. agalactiae ECP. However, only chemotactic activity was shown for S. iniae ECP. High-pressure liquid chromatography fractionation revealed that semi-purified S. agalactiae and S. iniae ECPs had estimated molecular weights of 7.54 and 19.2kDa, respectively. The prominent chemotactic activities of ECP from S. agalactiae and S. iniae are likely to be involved in the proinflammatory responses of macrophages to S. agalactiae and S. iniae infections. PMID:17212985

Klesius, Phillip H; Evans, Joyce J; Shoemaker, Craig A

2007-05-01

389

Transfer of Streptococcus faecalis and Streptococcus faecium to the Genus Enterococcus norn. rev. as Enterococcus faecalis comb. nov. and Enterococcus faecium comb. nov  

Microsoft Academic Search

The results of deoxyribonucleic acid-deoxyribonucleic acid and deoxyribonucleic acid-ribosomal ribonu- cleic acid hybridization studies demonstrated that Streptococcus faecalis and Streptococcus faecium are distantly related to the non-enterococcal streptococci (Streptococcus hovis and Streptococcus equinus) of serological group D and to other streptococci. On the basis of our results and those of previous studies, we propose that S. faecalis and S. faecium

KARL H. SCHLEIFER; RENATE KILPPER-BALZ

390

Recent advances in our understanding of Streptococcus pneumoniae infection  

PubMed Central

A number of significant challenges remain with regard to the diagnosis, treatment, and prevention of infections with Streptococcus pneumoniae (pneumococcus), which remains the most common bacterial cause of community-acquired pneumonia. Although this infection is documented to be extremely common in younger children and in older adults, the burden of pneumonia it causes is considerably underestimated, since the incidence statistics are derived largely from bacteremic infections, because they are easy to document, and yet the greater burden of pneumococcal pneumonias is non-invasive. It has been estimated that for every bacteremic pneumonia that is documented, three non-bacteremic infections occur. Management of these infections is potentially complicated by the increasing resistance of the isolates to the commonly used antibiotics. Furthermore, it is well recognized that despite advances in medical care, the mortality of bacteremic pneumococcal pneumonia has remained largely unchanged over the past 50 years and averages approximately 12%. Much recent research interest in the field of pneumococcal infections has focused on important virulence factors of the organism, on improved diagnostic and prognostication tools, on defining risk factors for death, on optimal treatment strategies involving both antibiotics and adjunctive therapies, and on disease prevention. It is hoped that through these endeavors the outlook of pneumococcal infections will be improved. PMID:25343039

Anderson, Ronald

2014-01-01

391

Requirement for Capsule in Colonization by Streptococcus pneumoniae  

PubMed Central

Nasopharyngeal colonization is a necessary first step in the pathogenesis of Streptococcus pneumoniae. Using isolates containing defined mutations in the S. pneumoniae capsule locus, we found that expression of the capsular polysaccharide is essential for colonization by the type 2 strain D39 and the type 3 strains A66 and WU2. Nonencapsulated derivatives of each of these strains were unable to colonize BALB/cByJ mice. Similarly, type 3 mutants that produced <6% of the parental amounts of capsule could not colonize. Capsule production equivalent to that of the parent strain was not required for efficient colonization, however, as type 3 mutants producing approximately 20% of the parental amounts of capsule colonized as effectively as the parent. This 80% reduction in capsule level had only a minimal effect on intraperitoneal virulence but caused a significant reduction in virulence via the intravenous route. In the X-linked immunodeficient CBA/N mouse, the type 3 mutant producing ?20% of the parental amount of capsule (AM188) was diminished in its ability to cause invasive disease and death following intranasal inoculation. Following intravenous or intraperitoneal challenge, however, only extended survival times were observed. Our results demonstrate an additional role for capsule in the pathogenesis of S. pneumoniae and show that isolates producing reduced levels of capsule can remain highly virulent. PMID:11349040

Magee, Ashalla D.; Yother, Janet

2001-01-01

392

Streptococcus faecium outbreak in a neonatal intensive care unit.  

PubMed Central

An outbreak of bacteremia and meningitis in a neonatal intensive care unit is described. Seven cases occurred in premature infants with severe underlying diseases. An epidemiological investigation failed to document the reservoir of the epidemic strain but suggested that its transmission among the infants was via the hands of hospital personnel. All patients had nasogastric tubes and multiple intravascular devices, and the portal of entry may have been either the gastrointestinal tract or the sites of the intravascular devices. Conventional biotyping of isolates failed to differentiate between isolates from infected patients and isolates recovered from prevalence surveys and from the environment. However, rapid identification systems (API-20S [Analytab Products, Plainview, N.Y.] and the AutoMicrobic system [Vitek Systems, Inc., Hazelwood, Mo.]) were able to distinguish isolates recovered from infected patients and hands of hospital personnel from isolates recovered during prevalence and environmental surveys and 29 isolates from widespread geographical areas. This is the first known report of a nosocomial neonatal outbreak of bacteremia and meningitis due to Streptococcus faecium; it underscores the importance of identifying streptococci to species level. PMID:6520215

Coudron, P E; Mayhall, C G; Facklam, R R; Spadora, A C; Lamb, V A; Lybrand, M R; Dalton, H P

1984-01-01

393

Human Streptococcus suis Endocarditis: Echocardiographic Features and Clinical Outcome  

PubMed Central

Background: Human Streptococcus suis endocarditis occurs infrequently and continues to be a serious illness with high mortality. However, knowledge of the echocardiographic features and clinical outcome of this disease remains unclear. Methods: One hundred and fourteen patients were identified in a prospective study, and hospitalized at Queen Sirikit Heart Center and Srinagarind Hospital, Khon Kaen University. Echocardiography was routinely performed in all patients. Results: Between January 2010 and December 2011, three cases of S. suis endocarditis were diagnosed. All cases were male and aged 27–53 years. The most common risk factor for contracting S. suis infection was eating undercooked pork. Three patients presented with congestive heart failure. Transthoracic echocardiography demonstrated large, highly mobile vegetations and severe valvular damage. Aortic valve involvement was documented in two patients, and mitral valve involvement in one. One patient presented with embolic stroke and one with arterial occlusion. All patients underwent urgent valve replacement with a good clinical outcome. Conclusion: The echocardiographic features of S. suis endocarditis show destructive, extensive valvular damage and early embolization with a fulminant course, needing early surgical intervention with a good clinical outcome. PMID:22872789

Pachirat, Orathai; Taksinachanekit, Suthep; Mootsikapun, Piroon; Kerdsin, Anusak

2012-01-01

394

Natural transformation and genome evolution in Streptococcus pneumoniae.  

PubMed

Streptococcus pneumoniae is a frequent colonizer of the human nasopharynx that has the potential to cause severe infections such as pneumonia, bacteremia and meningitis. Despite considerable efforts to reduce the burden of pneumococcal disease, it continues to be a major public health problem. After the Second World War, antimicrobial therapy was introduced to fight pneumococcal infections, followed by the first effective vaccines more than half a century later. These clinical interventions generated a selection pressure that drove the evolution of vaccine-escape mutants and strains that were highly resistant against antibiotics. The remarkable ability of S. pneumoniae to acquire drug resistance and evade vaccine pressure is due to its recombination-mediated genetic plasticity. S. pneumoniae is competent for natural genetic transformation, a property that enables the pneumococcus to acquire new traits by taking up naked DNA from the environment and incorporating it into its genome through homologous recombination. In the present paper, we review current knowledge on pneumococcal transformation, and discuss how the pneumococcus uses this mechanism to adapt and survive under adverse and fluctuating conditions. PMID:25445643

Straume, Daniel; Stamsås, Gro Anita; Håvarstein, Leiv Sigve

2014-11-01

395

Carbohydrate Availability Regulates Virulence Gene Expression in Streptococcus suis  

PubMed Central

Streptococcus suis is a major bacterial pathogen of young pigs causing worldwide economic problems for the pig industry. S. suis is also an emerging pathogen of humans. Colonization of porcine oropharynx by S. suis is considered to be a high risk factor for invasive disease. In the oropharyngeal cavity, where glucose is rapidly absorbed but dietary ?-glucans persist, there is a profound effect of carbohydrate availability on the expression of virulence genes. Nineteen predicted or confirmed S. suis virulence genes that promote adhesion to and invasion of epithelial cells were expressed at higher levels when S. suis was supplied with the ?-glucan starch/pullulan compared to glucose as the single carbon source. Additionally the production of suilysin, a toxin that damages epithelial cells, was increased more than ten-fold when glucose levels were low and S. suis was growing on pullulan. Based on biochemical, bioinformatics and in vitro and in vivo gene expression studies, we developed a biological model that postulates the effect of carbon catabolite repression on expression of virulence genes in the mucosa, organs and blood. This research increases our understanding of S. suis virulence mechanisms and has important implications for the design of future control strategies including the development of anti-infective strategies by modulating animal feed composition. PMID:24642967

Ferrando, M. Laura; van Baarlen, Peter; Orrù, Germano; Piga, Rosaria; Bongers, Roger S.; Wels, Michiel; De Greeff, Astrid; Smith, Hilde E.; Wells, Jerry M.

2014-01-01

396

Carbohydrate availability regulates virulence gene expression in Streptococcus suis.  

PubMed

Streptococcus suis is a major bacterial pathogen of young pigs causing worldwide economic problems for the pig industry. S. suis is also an emerging pathogen of humans. Colonization of porcine oropharynx by S. suis is considered to be a high risk factor for invasive disease. In the oropharyngeal cavity, where glucose is rapidly absorbed but dietary ?-glucans persist, there is a profound effect of carbohydrate availability on the expression of virulence genes. Nineteen predicted or confirmed S. suis virulence genes that promote adhesion to and invasion of epithelial cells were expressed at higher levels when S. suis was supplied with the ?-glucan starch/pullulan compared to glucose as the single carbon source. Additionally the production of suilysin, a toxin that damages epithelial cells, was increased more than ten-fold when glucose levels were low and S. suis was growing on pullulan. Based on biochemical, bioinformatics and in vitro and in vivo gene expression studies, we developed a biological model that postulates the effect of carbon catabolite repression on expression of virulence genes in the mucosa, organs and blood. This research increases our understanding of S. suis virulence mechanisms and has important implications for the design of future control strategies including the development of anti-infective strategies by modulating animal feed composition. PMID:24642967

Ferrando, M Laura; van Baarlen, Peter; Orrù, Germano; Piga, Rosaria; Bongers, Roger S; Wels, Michiel; De Greeff, Astrid; Smith, Hilde E; Wells, Jerry M

2014-01-01

397

In Vitro Functional and Immunomodulatory Properties of the Lactobacillus helveticus MIMLh5-Streptococcus salivarius ST3 Association That Are Relevant to the Development of a Pharyngeal Probiotic Product  

PubMed Central

The use of proper bacterial strains as probiotics for the pharyngeal mucosa is a potential prophylactic strategy for upper respiratory tract infections. In this context, we characterized in vitro the functional and immunomodulatory properties of the strains Lactobacillus helveticus MIMLh5 and Streptococcus salivarius ST3 that were selected during previous investigations as promising pharyngeal probiotics. In this study, we demonstrated in vitro that strains MIMLh5 and ST3, alone and in combination, can efficiently adhere to pharyngeal epithelial cells, antagonize Streptococcus pyogenes, and modulate host innate immunity by inducing potentially protective effects. In particular, we found that the strains MIMLh5 and ST3 activate U937 human macrophages by significantly inducing the expression of the proinflammatory cytokine tumor necrosis factor alpha (TNF-?). Nonetheless, the induction of the anti-inflammatory interleukin-10 (IL-10) by MIMLh5 or ST3 was never lower than that of TNF-?, suggesting that these bacteria can potentially exert a regulatory rather than a proinflammatory effect. We also found that the strains MIMLh5 and ST3 induce cyclooxygenase 2 (COX-2) expression and demonstrated that toll-like receptor 2 (TLR-2) participates in the recognition of the strains MIMLh5 and ST3 by U937 cells. Finally, we observed that these microorganisms grow efficiently when cocultured in milk, suggesting that the preparation of a milk-based fermented product containing both MIMLh5 and ST3 can be a practical solution for the administration of these bacteria. In conclusion, we propose the combined use of L. helveticus MIMLh5 and S. salivarius ST3 for the preparation of novel products that display probiotic properties for the pharyngeal mucosa. PMID:22504812

Taverniti, Valentina; Minuzzo, Mario; Arioli, Stefania; Junttila, Ilkka; Hämäläinen, Sanna; Turpeinen, Hannu; Mora, Diego; Karp, Matti; Pesu, Marko

2012-01-01

398

Natural Disruption of Two Regulatory Networks in Serotype M3 Group A Streptococcus Isolates Contributes to the Virulence Factor Profile of This Hypervirulent Serotype  

PubMed Central

Despite the public health challenges associated with the emergence of new pathogenic bacterial strains and/or serotypes, there is a dearth of information regarding the molecular mechanisms that drive this variation. Here, we began to address the mechanisms behind serotype-specific variation between serotype M1 and M3 strains of the human pathogen Streptococcus pyogenes (the group A Streptococcus [GAS]). Spatially diverse contemporary clinical serotype M3 isolates were discovered to contain identical inactivating mutations within genes encoding two regulatory systems that control the expression of important virulence factors, including the thrombolytic agent streptokinase, the protease inhibitor-binding protein-G-related ?2-macroglobulin-binding (GRAB) protein, and the antiphagocytic hyaluronic acid capsule. Subsequent analysis of a larger collection of isolates determined that M3 GAS, since at least the 1920s, has harbored a 4-bp deletion in the fasC gene of the fasBCAX regulatory system and an inactivating polymorphism in the rivR regulator-encoding gene. The fasC and rivR mutations in M3 isolates directly affect the virulence factor profile of M3 GAS, as evident by a reduction in streptokinase expression and an enhancement of GRAB expression. Complementation of the fasC mutation in M3 GAS significantly enhanced levels of the small regulatory RNA FasX, which in turn enhanced streptokinase expression. Complementation of the rivR mutation in M3 GAS restored the regulation of grab mRNA abundance but did not alter capsule mRNA levels. While important, the fasC and rivR mutations do not provide a full explanation for why serotype M3 strains are associated with unusually severe invasive infections; thus, further investigation is warranted. PMID:24516115

Cao, Tram N.; Liu, Zhuyun; Cao, Tran H.; Pflughoeft, Kathryn J.; Treviño, Jeanette; Danger, Jessica L.; Beres, Stephen B.; Musser, James M.

2014-01-01

399

Persistence of the Oral Probiotic Streptococcus salivarius M18 Is Dose Dependent and Megaplasmid Transfer Can Augment Their Bacteriocin Production and Adhesion Characteristics  

PubMed Central

Bacteriocin-producing probiotic Streptococcus salivarius M18 offers beneficial modulatory capabilities within the oral microbiome, apparently through potent inhibitory activity against potentially deleterious bacteria, such as Streptococcus pyogenes. The oral cavity persistence of S. salivarius M18 was investigated in 75 subjects receiving four different doses for 28 days. Sixty per cent of the subjects already had some inhibitor-producing S. salivarius in their saliva prior to probiotic intervention. Strain M18’s persistence was dependent upon the dose, but not the period of administration. Culture analysis indicated that in some individuals the introduced strain had almost entirely replaced the indigenous S. salivarius, though the total numbers of the species did not increase. Selected subjects showing either high or low probiotic persistence had their salivary populations profiled using Illumina sequencing of the V6 region of the 16S rRNA gene. Analysis indicated that while certain bacterial phenotypes were markedly modulated, the overall composition of the oral microbiome was not modified by the probiotic treatment. Megaplasmids encoding bacteriocins and adhesion factors were transferred in vitro to generate a transconjugant S. salivarius exhibiting enhanced antimicrobial production and binding capabilities to HEp-2 cells. Since no widespread perturbation of the existing indigenous microbiota was associated with oral instillation and given its antimicrobial activity against potentially pathogenic streptococci, it appears that application of probiotic strain M18 offers potential low impact alternative to classical antibiotic prophylaxis. For candidate probiotic strains having relatively poor antimicrobial or adhesive properties, unique derivatives displaying improved probiotic performance may be engineered in vitro by megaplasmid transfer. PMID:23785463

Burton, Jeremy P.; Wescombe, Philip A.; Macklaim, Jean M.; Chai, Melissa H. C.; MacDonald, Kyle; Hale, John D. F.; Tagg, John; Reid, Gregor; Gloor, Gregory B.; Cadieux, Peter A.

2013-01-01

400

Transfer of plasmids by conjugation in Streptococcus pneumoniae  

SciTech Connect

Transfer of resistance plasmids occurred by conjugation in Streptococcus pneumoniae (pneumococcus) similiarly to the process in other streptococcal groups. The 20-megadalton plasmid pIP501 mediated its own DNase-resistant transfer by filter mating and mobilized the 3.6-megadalton non-self-transmissible pMV158. Pneumococcal strains acted as donors or as recipients for intraspecies transfers and for interspecific transfers with Streptococcus faecalis. Transfer-deficient mutants of pIP501 have been found.

Smith, M.D.; Shoemaker, N.B.; Burdett, V.; Guild, W.R.

1980-01-01

401

Streptococcal Toxic Shock Syndrome Caused by Streptococcus suis Serotype 2  

Microsoft Academic Search

BackgroundStreptococcus suis serotype 2 ( S. suis 2, SS2) is a major zoonotic pathogen that causes only sporadic cases of meningitis and sepsis in humans. Most if not all cases of Streptococcal toxic shock syndrome (STSS) that have been well-documented to date were associated with the non-SS2 group A streptococcus (GAS). However, a recent large-scale outbreak of SS2 in Sichuan

Jiaqi Tang; Changjun Wang; Youjun Feng; Weizhong Yang; Huaidong Song; Zhihai Chen; Hongjie Yu; Xiuzhen Pan; Xiaojun Zhou; Huaru Wang; Bo Wu; Haili Wang; Huamei Zhao; Ying Lin; Jianhua Yue; Zhenqiang Wu; Xiaowei He; Feng Gao; Abdul Hamid Khan; Jian Wang; Guo-Ping Zhao; Yu Wang; Xiaoning Wang; Zhu Chen; George F Gao

2006-01-01

402

Résistances de Streptococcus pneumoniae et du groupe viridans aux fluoroquinolones  

Microsoft Academic Search

As in other Gram-positive bacteria, the resistance to fluoroquinolones (FQ) observed in Streptococcus pneumoniae and in Streptococcus viridans sp. involves two main mechanisms: modifications in their natural targets, gyrase and topo-isomerase IV; and the expression of an active efflux low-mechanism. For S. pneumoniae, the primary target, whose mutations are associated with the level resistance, depends on the FQ in question.

L. Gutmann; E. Varon

2001-01-01

403

Pyogenic granuloma of the large intestine: case report and review of reported cases in the adult.  

PubMed

Pyogenic granuloma (PG) is a polypoid lobular capillary hemangioma rarely described in the large bowel. We describe the case of a 72-year-old man with recent weight loss, anemia, and change in bowel habit. A 3cm×2cm polypoid lesion in the right flexure of the colon was observed and treated with extended right hemicolectomy. A review of the English-language literature on PG of the large bowel in adults yielded eight previously reported cases. The age of the patients ranged from 26 to 80 years with a mean of 54.8 years. The lesions were all solitary, except one case of multiple lesions in the colon. Another case was associated with satellite lesions. Seven cases were located in the colon and two in the rectum. The mean maximum diameter of the lesions was 1.6cm (range 0.5-3cm). Colorectal bleeding was the most common clinical symptom. Due to its unusual appearance, PG can be misdiagnosed and mistreated as colon carcinoma with extensive surgery. Polypectomy or endoscopy mucosal resection is the optimal treatment. In large or deep lesions, a surgical excision may be necessary. Pathologists should be familiar with this condition so as to avoid overdiagnosis as a malignant vascular tumor. PMID:23036166

Val-Bernal, José Fernando; Mayorga, Marta; García-Somacarrera, Elena

2012-11-15

404

Incidence and severity of Arcanobacterium pyogenes injection site abscesses with needle or needle-free injection.  

PubMed

Nursery-age pigs (n=198) were used to evaluate the difference in abscess formation at needle-free jet and conventional needle-and-syringe injection sites. Needle-free jet injection was used to administer injections in the neck and ham on one side of the animal whereas needle-and-syringe was used for neck and ham injections on the opposite side. Immediately prior to injection, the injection site surfaces were contaminated with an inoculum of Arcanobacterium pyogenes. Each pig was humanely euthanized 27 or 28 days after injections. Histopathological results showed that needle-free jet injection was associated with more abscesses than needle-and-syringe injection at both neck (P=0.0625) and ham (P=0.0313) injection sites. Out of 792 injection sites, only 13 abscesses were observed, with 12 of those present at needle-free jet injection sites. Needle-free jet injection may increase the occurrence of injection site abscesses that necessitate carcass trimming at pork processing plants. PMID:22854129

Gerlach, Bryce M; Houser, Terry A; Hollis, Larry C; Tokach, Michael D; Nietfeld, Jerome C; Higgins, James J; Anderson, Gary A; Goehring, Brandon L

2012-12-01

405

Biomechanical effects of steroid injections used to treat pyogenic flexor tenosynovitis  

PubMed Central

Background A recent study from our laboratory has demonstrated improved range of motion in the toes of broiler chickens afflicted with pyogenic flexor tenosynovitis when treated with local antibiotic and corticosteroid injections, without surgical drainage. However, the use of corticosteroids as an adjunct treatment raised peer concern, as steroids are thought to have deleterious effects on tendon strength. The purpose of this study was to compare the tensile strength of the aforementioned steroid treated tendons, to a group of tendons administered with the current standard treatment: systemic antibiotics, surgical drainage and no corticosteroids. Methods Twenty-three tendons’ structural and material properties were investigated (fifteen receiving the standard treatment, eight receiving the steroid treatment). The measurements from each group were interpreted via Student’s unpaired t-test and a post-hoc power analysis. Results The steroid treated tendons did demonstrate a trend toward decreased mechanical properties when compared with the standard treatment group, but the results were not statistically significant. Conclusions Treatment of septic tenosynovitis with local corticosteroid and local antibiotic injections resulted in better digital motion, without a significant loss of tendon strength, over a twenty-eight day recovery period. PMID:23047144

2012-01-01

406

Streptococcus iniae M-Like Protein Contributes to Virulence in Fish and Is a Target for Live Attenuated Vaccine Development  

PubMed Central

Background Streptococcus iniae is a significant pathogen in finfish aquaculture, though knowledge of virulence determinants is lacking. Through pyrosequencing of the S. iniae genome we have identified two gene homologues to classical surface-anchored streptococcal virulence factors: M-like protein (simA) and C5a peptidase (scpI). Methodology/Principal Findings S. iniae possesses a Mga-like locus containing simA and a divergently transcribed putative mga-like regulatory gene, mgx. In contrast to the Mga locus of group A Streptococcus (GAS, S. pyogenes), scpI is located distally in the chromosome. Comparative sequence analysis of the Mgx locus revealed only one significant variant, a strain with an insertion frameshift mutation in simA and a deletion mutation in a region downstream of mgx, generating an ORF which may encode a second putative mga-like gene, mgx2. Allelic exchange mutagenesis of simA and scpI was employed to investigate the potential role of these genes in S. iniae virulence. Our hybrid striped bass (HSB) and zebrafish models of infection revealed that M-like protein contributes significantly to S. iniae pathogenesis whereas C5a peptidase-like protein does not. Further, in vitro cell-based analyses indicate that SiMA, like other M family proteins, contributes to cellular adherence and invasion and provides resistance to phagocytic killing. Attenuation in our virulence models was also observed in the S. iniae isolate possessing a natural simA mutation. Vaccination of HSB with the ?simA mutant provided 100% protection against subsequent challenge with a lethal dose of wild-type (WT) S. iniae after 1,400 degree days, and shows promise as a target for live attenuated vaccine development. Conclusions/Significance Analysis of M-like protein and C5a peptidase through allelic replacement revealed that M-like protein plays a significant role in S. iniae virulence, and the Mga-like locus, which may regulate expression of this gene, has an unusual arrangement. The M-like protein mutant created in this research holds promise as live-attenuated vaccine. PMID:18665241

Locke, Jeffrey B.; Aziz, Ramy K.; Vicknair, Mike R.; Nizet, Victor; Buchanan, John T.

2008-01-01

407

Shr of Group A Streptococcus is a new type of composite NEAT protein involved in sequestering heme from methemoglobin  

PubMed Central

SUMMARY A growing body of evidence suggests that surface or secreted proteins with NEAr Transporter (NEAT) domains play a central role in heme acquisition and trafficking across the cell envelope of Gram-positive bacteria. Group A Streptococcus (GAS), a ?-hemolytic human pathogen, expresses a NEAT protein, Shr, which binds several hemoproteins and extracellular matrix (ECM) components. Shr is a complex, membrane-anchored protein, with a unique N-terminal domain (NTD) and two NEAT domains separated by a central leucine-rich repeat region. In this study we have carried out an analysis of the functional domains in Shr. We show that Shr obtains heme in solution and furthermore reduces the heme iron; this is the first report of heme reduction by a NEAT protein. More specifically, we demonstrate that both of the constituent NEAT domains of Shr are responsible for binding heme, although they are missing a critical tyrosine residue found in the ligand-binding pocket of other heme-binding NEAT domains. Further investigations show that a previously undescribed region within the Shr NTD interacts with methemoglobin. Shr NEAT domains, however, do not contribute significantly to the binding of methemoglobin but mediate binding to the ECM components fibronectin and laminin. A protein fragment containing the NTD plus the first NEAT domain was found to be sufficient to sequester heme directly from methemoglobin. Correlating these in vitro findings to in vivo biological function, mutants analysis establishes the role of Shr in GAS growth with methemoglobin as a sole source of iron, and indicates that at least one NEAT domain is necessary for the utilization of methemoglobin. We suggest that Shr is the prototype of a new group of NEAT composite proteins involved in heme uptake found in pyogenic streptococci and Clostridium novyi. PMID:20807204

Ouattara, Mahamoudou; Cunha, Elizabeth Bentley; Li, Xueru; Huang, Ya-Shu; Dixon, Dabney; Eichenbaum, Zehava

2010-01-01

408

Effect of Green Tea on Streptococcus mutans Metabolic Activity, Planktonic Growth, and Biofilm Activity in the Presence of Nicotine  

E-print Network

Effect of Green Tea on Streptococcus mutans Metabolic Activity, Planktonic Growth, and Biofilm of Cellular & Integrative Physiology at IU School of Medicine, Indianapolis, IN 46202 Streptococcus mutans

Zhou, Yaoqi

409

Nicotine Effects Surface Bound Enolase on Streptococcus mutans and Its Binding to Human Plasminogen Kamilah Walters1  

E-print Network

Nicotine Effects Surface Bound Enolase on Streptococcus mutans and Its Binding to Human Plasminogen University Indianapolis; 2 Department of Oral Biology, Indiana University School of Dentistry Streptococcus

Zhou, Yaoqi

410

21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

411

Susceptibility of Porphyromonas gingivalis and Streptococcus mutans to Antibacterial Effect from Mammea americana  

PubMed Central

The development of periodontal disease and dental caries is influenced by several factors, such as microorganisms of bacterial biofilm or commensal bacteria in the mouth. These microorganisms trigger inflammatory and immune responses in the host. Currently, medicinal plants are treatment options for these oral diseases. Mammea americana extracts have reported antimicrobial effects against several microorganisms. Nevertheless, this effect is unknown against oral bacteria. Therefore, the aim of this study was to evaluate the antibacterial effect of M. americana extract against Porphyromonas gingivalis and Streptococcus mutans. For this, an experimental study was conducted. Ethanolic extract was obtained from seeds of M. americana (one oil phase and one ethanolic phase). The strains of Porphyromonas gingivalis ATCC 33277 and Streptococcus mutans ATCC 25175 were exposed to this extract to evaluate its antibacterial effect. Antibacterial activity was observed with the two phases of M. americana extract on P. gingivalis and S. mutans with lower MICs (minimum inhibitory concentration). Also, bactericidal and bacteriostatic activity was detected against S. mutans, depending on the concentration of the extract, while on M. americana extract presented only bacteriostatic activity against P. gingivalis. These findings provide important and promising information allowing for further exploration in the future. PMID:24864137

Herrera Herrera, Alejandra; Franco Ospina, Luis; Fang, Luis; Díaz Caballero, Antonio

2014-01-01

412

Nasopharyngeal Carriage of Streptococcus pneumonia in Pneumonia-Prone Age Groups in Semarang, Java Island, Indonesia  

PubMed Central

Introduction Streptococcus pneumoniae is a worldwide occurring pathogen Nasopharyngeal carriage of Streptococcus pneumoniae precedes pneumonia and other pneumococcal diseases in the community. Little is known about S. pneumoniae carriage in Indonesia, complicating strategies to control pneumococcal diseases. We investigated nasopharyngeal carriage of S. pneumoniae in Semarang, Indonesia. Methods A population-based survey was performed in Semarang, Indonesia. Nasopharyngeal swabs and questionnaires were taken from 496 healthy young (6–60 month-old) children and 45–70 year-old adults. Results Forty-three percent of children aged 6–60 months and 11% of adults aged 45–75 years carried S. pneumoniae. Determinants of carriage were being a child (OR 7.7; 95% CI?=?4.5–13.0), passive smoking (OR 2.1; 95% CI?=?1.3–3.4), and contact with toddler(s) at home (OR 3.0; 95% CI?=?1.9–4.7). The most frequent serotypes found were 6A/B and 15B/C. The current commercially available vaccines cover <50% serotypes found in children. Twenty-four percent of S. pneumoniae strains were penicillin non-susceptible, and 45% were resistant to cotrimoxazol. Conclusions The limited coverage of commercially available vaccines against the serotypes found in this population, and the high proportion of non-susceptibility to penicillin and cotrimoxazol suggest the need for region-specific information and strategies to control S. pneumoniae. PMID:24498104

Farida, Helmia; Severin, Juliëtte A.; Gasem, M. Hussein; Keuter, Monique; Wahyono, Hendro; van den Broek, Peterhans; Hermans, Peter W. M.; Verbrugh, Henri A.

2014-01-01

413

The virulence of Streptococcus mutans and the ability to form biofilms.  

PubMed

In some diseases, a very important role is played by the ability of bacteria to form multi-dimensional complex structure known as biofilm. The most common disease of the oral cavity, known as dental caries, is a top leader. Streptococcus mutans, one of the many etiological factors of dental caries, is a microorganism which is able to acquire new properties allowing for the expression of pathogenicity determinants determining its virulence in specific environmental conditions. Through the mechanism of adhesion to a solid surface, S. mutans is capable of colonizing the oral cavity and also of forming bacterial biofilm. Additional properties enabling S. mutans to colonize the oral cavity include the ability to survive in an acidic environment and specific interaction with other microorganisms colonizing this ecosystem. This review is an attempt to establish which characteristics associated with biofilm formation--virulence determinants of S. mutans--are responsible for the development of dental caries. In order to extend the knowledge of the nature of Streptococcus infections, an attempt to face the following problems will be made: Biofilm formation as a complex process of protein-bacterium interaction. To what extent do microorganisms of the cariogenic flora exemplified by S. mutans differ in virulence determinants "expression" from microorganisms of physiological flora? How does the environment of the oral cavity and its microorganisms affect the biofilm formation of dominant species? How do selected inhibitors affect the biofilm formation of cariogenic microorganisms? PMID:24154653

Krzy?ciak, W; Jurczak, A; Ko?cielniak, D; Bystrowska, B; Skalniak, A

2014-04-01

414

Susceptibility of Porphyromonas gingivalis and Streptococcus mutans to Antibacterial Effect from Mammea americana.  

PubMed

The development of periodontal disease and dental caries is influenced by several factors, such as microorganisms of bacterial biofilm or commensal bacteria in the mouth. These microorganisms trigger inflammatory and immune responses in the host. Currently, medicinal plants are treatment options for these oral diseases. Mammea americana extracts have reported antimicrobial effects against several microorganisms. Nevertheless, this effect is unknown against oral bacteria. Therefore, the aim of this study was to evaluate the antibacterial effect of M. americana extract against Porphyromonas gingivalis and Streptococcus mutans. For this, an experimental study was conducted. Ethanolic extract was obtained from seeds of M. americana (one oil phase and one ethanolic phase). The strains of Porphyromonas gingivalis ATCC 33277 and Streptococcus mutans ATCC 25175 were exposed to this extract to evaluate its antibacterial effect. Antibacterial activity was observed with the two phases of M. americana extract on P. gingivalis and S. mutans with lower MICs (minimum inhibitory concentration). Also, bactericidal and bacteriostatic activity was detected against S. mutans, depending on the concentration of the extract, while on M. americana extract presented only bacteriostatic activity against P. gingivalis. These findings provide important and promising information allowing for further exploration in the future. PMID:24864137

Herrera Herrera, Alejandra; Franco Ospina, Luis; Fang, Luis; Díaz Caballero, Antonio

2014-01-01

415

Evaluation of 17 medicinal plants from Northern Côte d'Ivoire for their in vitro activity against Streptococcus pneumoniae.  

PubMed

Twenty crude extracts from 17 species out of 11 families were assessed for their antibacterial activity against Streptococcus pneumoniae (Pneumococcus). The selected plants are used in Northern Côte d'Ivoire to treat various infections including respiratory track diseases. From all the tested extracts, only 7 from 6 plants showed a promising in vitro bactericidal activity against Pneumococcus, including strains resistant to penicillin. The most active extracts were from Erythrina senegalensis (Fabaceae), Piliostigma thonningii (Caesalpiniaceae), Waltheria indica (Sterculiaceae), Andira inermis (Fabaceae), Uapaca togoensis (Euphorbiaceae), Keetia hispida (Rubiaceae) and Combretum molle (Combretaceae). This is the first time that the antipneumococcal activity of the tested plants is reported. The results of this preliminary investigation support the traditional use of these plants in the treatment of pneumococcal infections. The most active of them could be candidates for isolation of compounds which could serve as lead structures for the development of new drugs against Streptococcus pneumoniae. PMID:20162068

Koné, W Mamidou; Atindehou, K Kamanzi; Kacou-N'douba, A; Dosso, M

2006-01-01

416

INTERACTIONS OF HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS WITH TOBACCO TREATED STREPTOCOCCUS MUTANS  

E-print Network

INTERACTIONS OF HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS WITH TOBACCO TREATED STREPTOCOCCUS MUTANS Vinayak Gupta1 , L. Jack Windsor1 , Fengyu Song1 , and Richard Gregory1 Streptococcus mutans (S. mutans

Zhou, Yaoqi

417

Adverse Drug Reactions of Long-term Intravenous Antibiotics in Patients with Pyogenic Spondylitis  

PubMed Central

Objective The purpose of this study was to investigate the incidence, cause, and influence of the adverse drug reactions (ADRs) associated with long-term intravenous antibiotics in patients with pyogenic spondylitis (PS). Methods We retrospectively reviewed the medical records of 84 patients with PS who underwent intravenous antibiotic therapy in our hospital from January 2001 to December 2012. ADRs were categorized to drug eruption, acute renal failure (ARF), hematologic toxicity, toxic hepatitis, pseudomembranous colitis (PMC), drug fever, and neuronal toxicity. Incidence and onset time of each ADR after antibiotic therapy were analyzed with the incidence of ADRs according to types of antibiotics. Results ADRs occurred in 38 of the 84 patients (incidence: 45.2%). The use of antibiotics was longer in the patients with ADRs (62.7 days) than in the patients without ADRs (44.3 day). The incidence of drug eruption, ARF, hematologic toxicity, toxic hepatitis, PMC, drug fever, and neuronal toxicity were 22.6, 11.9, 11.9, 10.7, 7.1, 3.6%, and 1.2%, respectively. The duration of antibiotics administration was related to the occurrence of PMC (p=0.001). ADRs were more common in patients treated by glycopeptides including vacomycin and teicoplanin. Conclusion The incidence of ADRs due to long-term intravenous antibiotics was as high as 45.2% in patients with PS. Therefore, we speculate that the possibility of delayed ADRs should be considered after long-term use of the antibiotics. Furthermore, close observation is mandatory to identify and treat ADRs promptly, even though PS revealed the improvement after antibiotic therapy. PMID:25346755

Kim, Dong Hwan; Kim, Hwan Soo; Nam, Kyoung Hyup; Choi, Byung Kwan

2014-01-01

418

The Safety and Efficacy of Cadaveric Allografts and Titanium Cage as a Fusion Substitutes in Pyogenic Osteomyelitis  

PubMed Central

Objective The safety and efficacy of various fusion substitutes in pyogenic osteomyelitis has not been investigated. We evaluated and compared the cadaveric allograft and titanium cages used to reconstruct, maintain alignment and achieve fusion in the management of pyogenic spinal infection. Methods There were 33 patients with pyogenic osteomyelitis underwent fusion in this study. Fifteen of the 33 patients were operated on by fusion with allografts (cadaveric patella bones) and 18 of those were operated with titanium mesh cages filled with autologous cancellous iliac bone. After the affected disc and vertebral body resection with pus drainage, cadaveric allograft or titanium cages were inserted into the resected space. Posterior transpedicular screw fixation and rod compression in resected space, where cadaveric allograft or titanium cages were inserted, was performed to prevent the malposition in all patients except in 1 case. Recurrent infection was identified by serial erythrocyte sedimentation rate and cross reactive protein follow-up. Osseous union and recurred infection available at a minimum of 2 years following operation was identified. The amount of kyphosis correction and the subsidence were measured radiographically. Results Spinal fusion was achieved in 29 of 33 patients. In the cadaveric allograft group, 93.3% of patient (14 of 15) showed the osseous union while 83.3% of patient (15 of 18) in the titanium cage group showed union. Subsidence was noted in 12 of the patients. Twelve patients (36.3%) showed unsettling amounts of subsidence postoperatively whereas 46.6% of patients in the cadaveric allograft group and 37.7% of patients in the titanium cage group showed similar subsidence, respectively. There were statistical difference in the fusion rate (p=0.397) and subsidence rate (p=0.276) between the two groups. There was significant statistical difference in the postoperative improvement of segmental kyphosis between the two groups (p=0.022), that is the improvement in sagittal alignment was greater in the titanium cage group than in the cadaveric allograft group. There was no case of recurred infection. Conclusion The cadaveric allograft and titanium cages are effective and safe in restoring and maintaining sagittal plane alignment without increased incidence in infection recurrence in pyogenic osteomyelitis. The postoperative improvement of segmental kyphosis was better in the cage group. PMID:22200018

Kim, Hyun Woo; Ryu, Je-il

2011-01-01

419

?-Phosphoglucomutase contributes to aciduricity in Streptococcus mutans.  

PubMed

Streptococcus mutans encounters an array of sugar moieties within the oral cavity due to a varied human diet. One such sugar is ?-d-glucose 1-phosphate (?DG1P), which must be converted to glucose 6-phosphate (G6P) before further metabolism to lactic acid. The conversion of ?DG1P to G6P is mediated by ?-phosphoglucomutase, which has not been previously observed in any oral streptococci, but has been extensively characterized and the gene designated pgmB in Lactococcus lactis. An orthologue was identified in S. mutans, SMU.1747c, and deletion of the gene resulted in the inability of the deletion strain to convert ?DG1P to G6P, indicating that SMU.1747c is a ?-phosphoglucomutase and should be designated pgmB. In this study, we sought to characterize how deletion of pgmB affected known virulence factors of S. mutans, specifically acid tolerance. The ?pgmB strain showed a decreased ability to survive acid challenge. Additionally, the strain lacking ?-phosphoglucomutase had a diminished glycolytic profile compared with the parental strain. Deletion of pgmB had a negative impact on the virulence of S. mutans in the Galleria mellonella (greater wax worm) animal model. Our results indicate that pgmB plays a role at the juncture of carbohydrate metabolism and virulence. PMID:24509501

Buckley, Andrew A; Faustoferri, Roberta C; Quivey, Robert G

2014-04-01

420

Cloning of chromosomal genes in Streptococcus pneumoniae  

SciTech Connect

A system for molecular cloning in Streptococcus pneumoniae was developed. The multicopy plasmids pMV158 (5.4 kilobases) and pLS1 (4.3 kilobases), which confer tetracycline resistance, were used as vectors to clone chromosomal genes of S. pneumoniae in host cells of this species. A 3.3-kilobase restriction fragment containing the malM gene, which codes for amylomaltase, was cloned in a deletion mutant lacking chromosomal homology with the fragment. The recombinant plasmid, pLS70, could transform over 50% of a recipient population to maltose utilization. Amylomaltase constituted up to 10% of the protein of cells containing pLS70. A derivative with a deletion, pLS69, appeared to gain a selective advantage by producing less enzyme. A 10-kilobase restriction fragment containing the sul-d gene for sulfonamide resistance was cloned in the presence of the homologous chromosomal gene. De novo establishment of a recombinant plasmid was just as frequent as transformation in an endogenous plasmid. Despite the processing of DNA during uptake in the transformation of S. pneumoniae, recombinant plasmids can be introduced. Models for the reconstruction of recombinant DNA in cells of S. pneumoniae and Bacillus subtilis are considered and compared.

Stassi, D.L.; Lopez, P.; Espinosa, M.; Lacks, S.A.

1981-11-01

421

Ornithine transport and exchange in Streptococcus lactis  

SciTech Connect

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

Thompson, J.

1987-09-01

422

Peptide pheromone signaling in Streptococcus and Enterococcus  

PubMed Central

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

Cook, Laura C.; Federle, Michael J.

2014-01-01

423

Effect of immunization on susceptibility to experimental Streptococcus mutans and Streptococcus sanguis endocarditis.  

PubMed Central

It has been asserted that humoral immunity is an important potentiating factor in pathogenesis of infective endocarditis, in that prior immunization to certain bacteria may predispose the host to endocarditis caused by those organisms. If so, possible future vaccination of humans with streptococcal antigens for the prevention of dental caries might increase the susceptibility of the population to streptococcal endocarditis. To examine this hypothesis further, we immunized rabbits with killed Streptococcus sanguis or Streptococcus mutans. After complement-fixing antibody had developed, the rabbits were tested for susceptibility to experimental infective endocarditis. Rabbits with high titers of complement-fixing antibody to the infecting organism developed streptococcal endocarditis less often (13%) than animals with lower titers (69%; P less than 0.0002). These findings do not support the hypothesis that pre-immunization predisposes to infective endocarditis and lend no credence to the concept that vaccination of human subjects against dental caries might increase their susceptibility to streptococcal endocarditis. On the contrary, the results of these experiments indicate that specific antibody can confer relative immunity to infective endocarditis. PMID:730349

Durack, D T; Gilliland, B C; Petersdorf, R G

1978-01-01

424

Detection of Streptococcus suis in Bioaerosols of Swine Confinement Buildings  

PubMed Central

Streptococcus suis is an important swine pathogen that can cause septicemia, meningitis, and pneumonia. Also recognized as an emerging zoonotic agent, it is responsible for outbreaks of human infections in Asian countries. Serotype 2 is the predominant isolate from diseased animals and humans. The aerosolization of S. suis in the air of swine confinement buildings (SCB) was studied. The presence of S. suis in bioaerosols was monitored in SCB where cases of infection had been reported and in healthy SCB without reported infections. Using a quantitative-PCR (qPCR) method, we determined the total number of bacteria (1 × 108 to 2 × 108 airborne/m3), total number of S. suis bacteria (4 × 105 to 10 × 105 airborne/m3), and number of S. suis serotype 2 and 1/2 bacteria (1 × 103 to 30 × 103 airborne/m3) present in the air. S. suis serotypes 2 and 1/2 were detected in the air of all growing/finishing SCB that had documented cases of S. suis infection and in 50% of healthy SCB. The total number of bacteria and total numbers of S. suis and S. suis serotype 2 and 1/2 bacteria were monitored in one positive SCB during a 5-week period, and it was shown that the aerosolized S. suis serotypes 2 and 1/2 remain airborne for a prolonged period. When the effect of aerosolization on S. suis was observed, the percentage of intact S. suis bacteria (showing cell membrane integrity) in the air might have been up to 13%. Finally S. suis was found in nasal swabs from 14 out of 21 healthy finishing-SCB workers, suggesting significant exposure to the pathogen. This report provides a better understanding of the aerosolization, prevalence, and persistence of S. suis in SCB. PMID:24632262

Bonifait, Laetitia; Veillette, Marc; Létourneau, Valérie; Grenier, Daniel

2014-01-01

425

Phenotypic Heterogeneity of Genomically-Diverse Isolates of Streptococcus mutans  

PubMed Central

High coverage, whole genome shotgun (WGS) sequencing of 57 geographically- and genetically-diverse isolates of Streptococcus mutans from individuals of known dental caries status was recently completed. Of the 57 sequenced strains, fifteen isolates, were selected based primarily on differences in gene content and phenotypic characteristics known to affect virulence and compared with the reference strain UA159. A high degree of variability in these properties was observed between strains, with a broad spectrum of sensitivities to low pH, oxidative stress (air and paraquat) and exposure to competence stimulating peptide (CSP). Significant differences in autolytic behavior and in biofilm development in glucose or sucrose were also observed. Natural genetic competence varied among isolates, and this was correlated to the presence or absence of competence genes, comCDE and comX, and to bacteriocins. In general strains that lacked the ability to become competent possessed fewer genes for bacteriocins and immunity proteins or contained polymorphic variants of these genes. WGS sequence analysis of the pan-genome revealed, for the first time, components of a Type VII secretion system in several S. mutans strains, as well as two putative ORFs that encode possible collagen binding proteins located upstream of the cnm gene, which is associated with host cell invasiveness. The virulence of these particular strains was assessed in a wax-worm model. This is the first study to combine a comprehensive analysis of key virulence-related phenotypes with extensive genomic analysis of a pathogen that evolved closely with humans. Our analysis highlights the phenotypic diversity of S. mutans isolates and indicates that the species has evolved a variety of adaptive strategies to persist in the human oral cavity and, when conditions are favorable, to initiate disease. PMID:23613838

Palmer, Sara R.; Miller, James H.; Abranches, Jacqueline; Zeng, Lin; Lefebure, Tristan; Richards, Vincent P.; Lemos, José A.; Stanhope, Michael J.; Burne, Robert A.

2013-01-01

426

Group B Streptococcus Engages an Inhibitory Siglec through Sialic Acid Mimicry to Blunt Innate Immune and  

E-print Network

Group B Streptococcus Engages an Inhibitory Siglec through Sialic Acid Mimicry to Blunt Innate Streptococcus (GBS) is a common agent of bacterial sepsis and meningitis in newborns. The GBS surface capsule al. (2014) Group B Streptococcus Engages an Inhibitory Siglec through Sialic Acid Mimicry to Blunt

Nizet, Victor

427

Mutual Exclusivity of Hyaluronan and Hyaluronidase in Invasive Group A Streptococcus*S  

E-print Network

Mutual Exclusivity of Hyaluronan and Hyaluronidase in Invasive Group A Streptococcus*S Received Children's Hospital, San Diego, California 92123 Background: Serotype M4 group A Streptococcus lack exclusive interaction between GAS capsule and HylA expression. A recent analysis of group A Streptococcus

Nizet, Victor

428

General properties and substrate specificity of an intracellular soluble dipeptidase from Streptococcus diacetilactis  

E-print Network

Streptococcus diacetilactis M. J. DESMAZEAUD Claude ZEVACO Laboratoire de Biochimie microbienne, LN.R.A. 78350 and Seeley, 1974). Streptococcus diacetilactis in particular requires arginine or phenylalanine (Reiter of peptidic stimulation of lactic streptococcus growth in milk. Since these peptides are a source of amino

Paris-Sud XI, Université de

429

Efficacy of polymeric encapsulated C5a peptidasebased group B streptococcus vaccines in a murine model  

E-print Network

Efficacy of polymeric encapsulated C5a peptidase­based group B streptococcus vaccines in a murine. Key words: antigen encapsulation, C5a peptidase, group B streptococcus, microparticle, microsphere al. Efficacy of polymeric encapsulated C5a peptidase­based group B streptococcus vaccines in a murine

Salem, Aliasger K.

430

Streptolysin O Promotes Group A Streptococcus Immune Evasion by Accelerated Macrophage Apoptosis*  

E-print Network

Streptolysin O Promotes Group A Streptococcus Immune Evasion by Accelerated Macrophage Apoptosis and §§ Department of Biology, San Diego State University, San Diego, California 92182 Group A Streptococcus (GAS A Streptococcus (GAS)4 is a leading human pathogen that annually infects hundreds of millions of people worldwide

Nizet, Victor

431

Functional characterization of cell-wall-associated protein WapA in Streptococcus mutans  

E-print Network

Functional characterization of cell-wall-associated protein WapA in Streptococcus mutans Lin Zhu,1 9 April 2006 Streptococcus mutans is known as a primary pathogen responsible for dental caries. One­cell aggregation and biofilm architecture. INTRODUCTION Streptococcus mutans is considered as a principal patho

Gimzewski, James

432

JCM00175-09 -Revised Manuscript.1 Identification of Streptococcus agalactiae isolates from various phylogenetic2  

E-print Network

1 JCM00175-09 - Revised Manuscript.1 Identification of Streptococcus agalactiae isolates from this method, we identified 11029 Streptococcus agalactiae isolates characterized by serotyping and MLST-00557578,version1-21Jan2011 #12;3 Streptococcus agalactiae is the main cause of neonatal infections and has

Paris-Sud XI, Université de

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COMPARISON OF STREPTOCOCCUS UBERIS AND S. INFREQUENS. PATHOGENICITY FOR COW UDDER  

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COMPARISON OF STREPTOCOCCUS UBERIS AND S. INFREQUENS. PATHOGENICITY FOR COW UDDER M. ROGUINSKY I COMPARAISON DE STREPTOCOCCUS UBERIS ET DE S. INFREOUENS. PATHOGENICITE POUR LA MAMELLE DE LA VACHE. - On a comparé la pathogénicité de Streptococcus uberis et de S. infrequens pour la mamelle de la vache, en

Boyer, Edmond

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Strain-associated virulence factors of Streptococcus iniae in hybrid-striped bass  

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Strain-associated virulence factors of Streptococcus iniae in hybrid-striped bass John T. Buchanan 2007; received in revised form 24 February 2008; accepted 26 February 2008 Abstract Streptococcus iniae previously associated with virulence in other species of pathogenic Streptococcus in animals and humans

Nizet, Victor

435

Bioprospecting of strains of Streptococcus thermophilus from Indian fermented milk products  

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NOTE Bioprospecting of strains of Streptococcus thermophilus from Indian fermented milk products-prospecting of folate producing strains of Streptococcus thermophilus isolated from milk and different fermented milk·L-1 RAPD - PCR 10 LacZ , GenBank FJ161697 FJ161698 Keywords Streptococcus thermophilus . Folate

Boyer, Edmond

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Alternate Structural Conformations of Streptococcus pneumoniae Hyaluronan Lyase: Insights into Enzyme  

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Alternate Structural Conformations of Streptococcus pneumoniae Hyaluronan Lyase: Insights Chemistry, Am Fa�berg 11 37077 Go¨ttingen, Germany Streptococcus pneumoniae hyaluronan lyase is a surface and Streptococcus agalactiae, allowed for insights into this enzyme's molecular mechanism. Here, two new X

de Groot, Bert