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1

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

PubMed

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

Le Breton, Yoann; McIver, Kevin S

2013-01-01

2

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

PubMed Central

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

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

2009-01-01

3

[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

4

M1 Protein-Dependent Intracellular Trafficking Promotes Persistence and Replication of Streptococcus pyogenes in Macrophages  

Microsoft Academic Search

Streptococcus pyogenes is an important human pathogen that causes a variety of diseases including life-threatening invasive diseases, such as toxic shock and deep tissue infections. Although S. pyogenes are classically considered extracellular pathogens, a clinical significance of an intracellular source has been emphasized. In patients with deep tissue infections, an intracellular reservoir of S. pyogenes within macrophages was shown to

Erika Hertzén; Linda Johansson; Robert Wallin; Heike Schmidt; Mirko Kroll; Anders P. Rehn; Malak Kotb; Matthias Mörgelin; Anna Norrby-Teglund

2010-01-01

5

Surface Interactome in Streptococcus pyogenes*  

PubMed Central

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

2012-01-01

6

A Rare Cause of Endocarditis: Streptococcus pyogenes  

PubMed Central

Although group A ?-hemolytic streptococcus is an uncommon cause of infective endocarditis, an increase in the incidence of invasive group A streptococcus infections including bacteremia has been reported in the last two decades. Herein we report Streptococcus pyogenes endocarditis in a previously healthy adult patient who was hospitalized to investigate the etiology of fever. Because of a suspicion of a new vegetation appeared in the second (aortic) valve in the 14th day of high dose penicillin G treatment, the mitral and aortic valves were replaced by mechanical prosthesis on the 22nd day of treatment. He was discharged from hospital after the 6 week course of antibiotic treatment. PMID:25207027

Ye?ilkaya, Ay?egül; Azap, Özlem Kurt; Pirat, Bahar; Gültekin, Bahad?r; Arslan, Hande

2012-01-01

7

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

8

[Epidemiology of Streptococcus pyogenes invasive diseases in France (2007-2011)].  

PubMed

Group A Streptococcus (GAS) is a human pathogen responsible for a wide range of clinical manifestations. An increase of GAS invasive infections has been described since the mid 1980s. To study the French epidemiology of invasive infections (i) we characterized all GAS invasive strains received at the French National Reference Center for streptococci (CNR-Strep) between 2007 and 2011; (ii) we analyzed the epidemiological data on the corresponding strains. For each strain, emm genotype, superantigen genes and antibiotics susceptibility were determined. Among the 2 603 non redundant invasive GAS strains, 65.1 % (n=1 695) were isolated from blood culture. A streptococcal toxic shock syndrome (STSS) was described in 16.4 % (n=428) of cases, mostly associated with necrotizing fasciitis (NF), pleuropulmonary or osteoarticular infections (p ?0.001). The case fatality rate was 10.6 %. A total of 102 different emm genotypes were identified. Three emm genotypes predominated, reaching nearly 60 % of the strains: emm 1 (26.7 %), emm 28 (16.4 %), and emm 89 (12.8 %). The proportion of each emm genotype varied according to the year and the age of patients. Among those < 15 years old, the three main genotypes were emm 1 (36.8 %), emm 12 (12.9 %) and emm 4 (9.5 %). The distribution of superantigen genes (SpeA, SpeC and Ssa) was restricted to several emm genotypes. Between 2007 and 2011, the rate of macrolides resistant GAS strains decreased from 7.8 to 5.5 %. emm 1 strains are still the most common especially in most severe clinical manifestations including STSS and NF. PMID:25456682

Plainvert, C; Loubinoux, J; Bidet, P; Doloy, A; Touak, G; Dmytruk, N; Collobert, G; Bingen, E; Bouvet, A; Fouet, A; Poyart, C

2014-11-01

9

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

10

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

11

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

12

Interactions of Lactobacilli with Pathogenic Streptococcus pyogenes  

PubMed Central

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

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

2010-01-01

13

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

14

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

15

Toll-like receptor 4 gene (TLR4), but not TLR2, polymorphisms modify the risk of tonsillar disease due to Streptococcus pyogenes and Haemophilus influenzae.  

PubMed

Tonsillar disease (recurrent tonsillitis and/or tonsillar hypertrophy) is one of the most common human disorders, with Streptococcus pyogenes (group A beta-hemolytic streptococcus [GAS]) and Haemophilus influenzae representing the most common pathogens. Until now, no study has investigated why some individuals are more susceptible to tonsillar infections caused by specific bacteria than others. The aim of this study was to uncover possible associations between common Toll-like receptor gene (TLR) polymorphisms and tonsillar disease. The TLR2-R753Q, TLR4-D299G, and TLR4-T399I polymorphisms were determined in a cohort of 327 patients subjected to tonsillectomy due to recurrent tonsillitis (n = 245) and tonsillar hypertrophy (n = 82) and 245 healthy bone marrow donors. Associations of the aforementioned polymorphisms with the isolated bacterial strains after tonsillectomy were also investigated. Interestingly, carriers of the TLR4 polymorphisms displayed an approximately 3-fold increased risk for GAS infections (for TLR4-D299G, odds ratio [OR] = 2.81, 95% confidence interval [CI] = 1.16 to 6.79, P = 0.038; for TLR4-T399I, OR = 3.01, 95% CI = 1.29 to 7.02, P = 0.023), and this association was more profound in patients with recurrent tonsillitis. On the contrary, the presence of the TLR4-T399I polymorphism was associated with a 2-fold decreased risk of Haemophilus influenzae carriage (OR = 0.38, 95% CI = 0.15 to 0.96, P = 0.038). In the end, no significant differences were observed, considering the genotype and allele frequencies of the above-mentioned polymorphisms, between patients and controls. Our findings indicate that, regarding tonsillar infections, TLR4 polymorphisms predispose individuals to GAS infection, while they are protective against Haemophilus influenzae infection. This result further elucidates the role that host immune genetic variations might play in the susceptibility to common infections and tonsillar disease. PMID:21159925

Liadaki, Kyriaki; Petinaki, Efthimia; Skoulakis, Charalampos; Tsirevelou, Paraskeui; Klapsa, Dimitra; Germenis, Anastasios E; Speletas, Matthaios

2011-02-01

16

Identification of Rgg-Regulated Exoproteins of Streptococcus pyogenes  

Microsoft Academic Search

Streptococcus pyogenes secretes many proteins that influence host-pathogen interactions. Despite their im- portance, relatively little is known about the regulation of these proteins. The rgg gene (also known as ropB) is required for the expression of streptococcal erythrogenic toxin B (SPE B), an extracellular cysteine protease that contributes to virulence. Proteomics was used to determine if rgg regulates the expression

MICHAEL S. CHAUSSEE; ROBERT O. WATSON; JAMES C. SMOOT; JAMES M. MUSSER

2001-01-01

17

Predictors of death after severe Streptococcus pyogenes infection.  

PubMed

An evaluation of the relative importance of host and pathogen factors on the survival rate of patients with invasive Streptococcus pyogenes infection found a number of clinical and demographic factors to be associated with risk for death. Some evidence suggested a seasonal pattern to patient survival rate. PMID:19751599

Lamagni, Theresa L; Neal, Shona; Keshishian, Catherine; Powell, David; Potz, Nicola; Pebody, Richard; George, Robert; Duckworth, Georgia; Vuopio-Varkila, Jaana; Efstratiou, Androulla

2009-08-01

18

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

PubMed

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

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

2014-09-01

19

Molecular epidemiology of sil locus in clinical Streptococcus pyogenes strains.  

PubMed

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

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

2014-06-01

20

Molecular Epidemiology of sil Locus in Clinical Streptococcus pyogenes Strains  

PubMed Central

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

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

2014-01-01

21

The role of coagulation/fibrinolysis during Streptococcus pyogenes infection  

PubMed Central

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

22

Streptococcus pyogenes pneumonia with abscess formation.  

PubMed

A 30-year-old female with mild asthma presented with high fever, hypotension, pleuritic chest pain, vomiting and diarrhea. Chest radiograph showed consolidation of the right upper lobe, and S. pyogenes was cultured from blood and sputum. Following initial rapid recovery the patient relapsed ten days after antibiotics were ceased, with rapid development of a large abscess cavity. Clinical improvement occurred following reinstitution of treatment including intravenous penicillin. Progressive radiological resolution eventuated during outpatient follow-up. This case demonstrates that S. pyogenes pneumonia may occur without an antecedent viral infection or major predisposing condition, cause rapid cavitation despite antiobiotic therapy and resolve satisfactorily with prolonged penicillin therapy. PMID:2673177

McIntyre, H D; Armstrong, J G; Mitchell, C A

1989-06-01

23

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

24

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

25

Emergence of Streptococcus pyogenes strains resistant to erythromycin in Gipuzkoa, Spain  

Microsoft Academic Search

The aim of this study was to determine the evolution of resistance to macrolides and other antibiotics in strains ofStreptococcus pyogenes isolated in the province of Gipuzkoa, Spain. During the period 1984–1996, all 2561 strains ofStreptococcus pyogenes studied showed full susceptibility to penicillin. Until 1990, only 1.2% ofStreptococcus pyogenes isolates were resistant to erythromycin. Since then, resistance to erythromycin increased

E. Perez-Trallero; M. Urbieta; M. Montes; I. Ayestaran; J. M. Marimon

1998-01-01

26

In Vitro Antibacterial Activity of Essential Oils against Streptococcus pyogenes.  

PubMed

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

27

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

28

Macrolide-resistant Streptococcus pyogenes: prevalence and treatment strategies.  

PubMed

Although penicillin remains the first-choice treatment for Streptococcus pyogenes infection, macrolides are important alternatives for allergic patients and lincosamides are recommended together with ?-lactams in invasive infections. S. pyogenes may exhibit macrolide resistance because of active efflux (mef genes) or target modification (erm genes), the latter conferring cross resistance to lincosamides and streptogramin B. Worldwide, resistance is restricted to a limited number of genetic lineages, despite resistance genes being encoded on mobile genetic elements. For reasons that are not completely clear, resistance and the associated phenotypes are highly variable across countries. Although resistance remains high in several countries, particularly in Asia, an overall decreasing trend of resistance has been noted in recent years, mostly in Europe. This decrease is not always accompanied by declines in macrolide consumption, suggesting significant roles of other factors in determining the dynamics of macrolide-resistant clones. Continued surveillance is needed to obtain further insights into the forces governing macrolide resistance in S. pyogenes. PMID:25746210

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

2015-05-01

29

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

30

Proteomic Analysis and Identification of Streptococcus pyogenes Surface-Associated Proteins  

Microsoft Academic Search

Streptococcus pyogenes is a gram-positive human pathogen that causes a wide spectrum of disease, placing a significant burden on public health. Bacterial surface-associated proteins play crucial roles in host-pathogen interactions and pathogenesis and are important targets for the immune system. The identification of these proteins for vaccine development is an important goal of bacterial proteomics. Here we describe a method

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

2007-01-01

31

Streptococcus pyogenes biofilms—formation, biology, and clinical relevance  

PubMed Central

Streptococcus pyogenes (group A streptococci, GAS) is an exclusive human bacterial pathogen. The virulence potential of this species is tremendous. Interactions with humans range from asymptomatic carriage over mild and superficial infections of skin and mucosal membranes up to systemic purulent toxic-invasive disease manifestations. Particularly the latter are a severe threat for predisposed patients and lead to significant death tolls worldwide. This places GAS among the most important Gram-positive bacterial pathogens. Many recent reviews have highlighted the GAS repertoire of virulence factors, regulators and regulatory circuits/networks that enable GAS to colonize the host and to deal with all levels of the host immune defense. This covers in vitro and in vivo studies, including animal infection studies based on mice and more relevant, macaque monkeys. It is now appreciated that GAS, like many other bacterial species, do not necessarily exclusively live in a planktonic lifestyle. GAS is capable of microcolony and biofilm formation on host cells and tissues. We are now beginning to understand that this feature significantly contributes to GAS pathogenesis. In this review we will discuss the current knowledge on GAS biofilm formation, the biofilm-phenotype associated virulence factors, regulatory aspects of biofilm formation, the clinical relevance, and finally contemporary treatment regimens and future treatment options. PMID:25717441

Fiedler, Tomas; Köller, Thomas; Kreikemeyer, Bernd

2015-01-01

32

Streptococcus pyogenes biofilms-formation, biology, and clinical relevance.  

PubMed

Streptococcus pyogenes (group A streptococci, GAS) is an exclusive human bacterial pathogen. The virulence potential of this species is tremendous. Interactions with humans range from asymptomatic carriage over mild and superficial infections of skin and mucosal membranes up to systemic purulent toxic-invasive disease manifestations. Particularly the latter are a severe threat for predisposed patients and lead to significant death tolls worldwide. This places GAS among the most important Gram-positive bacterial pathogens. Many recent reviews have highlighted the GAS repertoire of virulence factors, regulators and regulatory circuits/networks that enable GAS to colonize the host and to deal with all levels of the host immune defense. This covers in vitro and in vivo studies, including animal infection studies based on mice and more relevant, macaque monkeys. It is now appreciated that GAS, like many other bacterial species, do not necessarily exclusively live in a planktonic lifestyle. GAS is capable of microcolony and biofilm formation on host cells and tissues. We are now beginning to understand that this feature significantly contributes to GAS pathogenesis. In this review we will discuss the current knowledge on GAS biofilm formation, the biofilm-phenotype associated virulence factors, regulatory aspects of biofilm formation, the clinical relevance, and finally contemporary treatment regimens and future treatment options. PMID:25717441

Fiedler, Tomas; Köller, Thomas; Kreikemeyer, Bernd

2015-01-01

33

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

34

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

PubMed

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; Fischetti, Vincent A

2013-06-01

35

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

36

Extensive Diversity of Streptococcus pyogenes in a Remote Human Population Reflects Global-Scale Transmission Rather than Localised Diversification  

PubMed Central

The Indigenous population of the Northern Territory of Australia (NT) suffers from a very high burden of Streptococcus pyogenes disease, including cardiac and renal sequelae. The aim of this study was to determine if S. pyogenes isolated from this population represent NT endemic strains, or conversely reflect strains with global distribution. emm sequence typing data were used to select 460 S. pyogenes isolates representing NT S. pyogenes diversity from 1987–2008. These isolates were genotyped using either multilocus sequence typing (MLST) or a high resolution melting-based MLST surrogate (Minim typing). These data were combined with MLST data from other studies on NT S. pyogenes to yield a set of 731 MLST or Minim typed isolates for analysis. goeBURST analysis of MLST allelic profiles and neighbour-joining trees of the MLST allele sequences revealed that a large proportion of the known global S. pyogenes MLST-defined diversity has now been found in the NT. Specifically, fully sequence typed NT isolates encompass 19% of known S. pyogenes STs and 43% of known S. pyogenes MLST alleles. These analyses provided no evidence for major NT-endemic strains, with many STs and MLST alleles shared between the NT and the rest of the world. The relationship between the number of known Minim types, and the probability that a Minim type identified in a calendar year would be novel was determined. This revealed that Minim types typically persist in the NT for >1 year, and indicate that the majority of NT Minim types have been identified. This study revealed that many diverse S. pyogenes strains exhibit global scale mobility that extends to isolated populations. The burden of S. pyogenes disease in the NT is unlikely to be due to the nature of NT S. pyogenes strains, but is rather a function of social and living conditions. PMID:24066079

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

2013-01-01

37

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.

38

Molecular Analysis of an Outbreak of Lethal Postpartum Sepsis Caused by Streptococcus pyogenes  

PubMed Central

Sepsis is now the leading direct cause of maternal death in the United Kingdom, and Streptococcus pyogenes is the leading pathogen. We combined conventional and genomic analyses to define the duration and scale of a lethal outbreak. Two postpartum deaths caused by S. pyogenes occurred within 24 h; one was characterized by bacteremia and shock and the other by hemorrhagic pneumonia. The women gave birth within minutes of each other in the same maternity unit 2 days earlier. Seven additional infections in health care and household contacts were subsequently detected and treated. All cluster-associated S. pyogenes isolates were genotype emm1 and were initially indistinguishable from other United Kingdom emm1 isolates. Sequencing of the virulence gene sic revealed that all outbreak isolates had the same unique sic type. Genome sequencing confirmed that the cluster was caused by a unique S. pyogenes clone. Transmission between patients occurred on a single day and was associated with casual contact only. A single isolate from one patient demonstrated a sequence change in sic consistent with longer infection duration. Transmission to health care workers was traced to single clinical contacts with index cases. The last case was detected 18 days after the first case. Following enhanced surveillance, the outbreak isolate was not detected again. Mutations in bacterial regulatory genes played no detectable role in this outbreak, illustrating the intrinsic ability of emm1 S. pyogenes to spread while retaining virulence. This fast-moving outbreak highlights the potential of S. pyogenes to cause a range of diseases in the puerperium with rapid transmission, underlining the importance of immediate recognition and response by clinical infection and occupational health teams. PMID:23616448

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

2013-01-01

39

Variability in the Distribution of Genes Encoding Virulence Factors and Putative Extracellular Proteins of Streptococcus pyogenes in India, a Region with High Streptococcal Disease Burden, and Implication for Development of a Regional Multisubunit Vaccine  

PubMed Central

Streptococcus pyogenes causes a wide variety of human diseases and is a significant cause of morbidity and mortality. Attempts to develop a vaccine were hampered by the genetic diversity of S. pyogenes across different regions of the world. This study sought to identify streptococcal antigens suitable for a region-specific vaccine in India. We used a two-step approach, first performing epidemiological analysis to identify the conserved antigens among Indian isolates. The second step consisted of validating the identified antigens by serological analysis. The 201 streptococcal clinical isolates from India used in this study represented 69 different emm types, with emm12 being the most prevalent. Virulence profiling of the North and South Indian S. pyogenes isolates with a custom-designed streptococcal virulence microarray identified seven conserved putative vaccine candidates. Collagen-like surface protein (SCI), putative secreted 5?-nucleotidase (PSNT), and C5a peptidase were found in 100% of the isolates, while R28, a putative surface antigen (PSA), and a hypothetical protein (HYP) were found in 90% of the isolates. A fibronectin binding protein, SfbI, was present in only 78% of the isolates. In order to validate the identified potential vaccine candidates, 185 serum samples obtained from patients with different clinical manifestations were tested for antibodies. Irrespective of clinical manifestations, serum samples showed high antibody titers to all proteins except for SCI and R28. Thus, the data indicate that PSNT, C5a peptidase, PSA, HYP, and SfbI are promising candidates for a region-specific streptococcal vaccine for the different parts of India. PMID:22971782

Sagar, Vivek; Bergmann, René; Nerlich, Andreas; McMillan, David J.; Nitsche Schmitz, D. Patric

2012-01-01

40

Molecular characterization of macrolide resistance mechanisms among Streptococcus pneumoniae and Streptococcus pyogenes isolated from the PROTEKT 1999-2000 study  

Microsoft Academic Search

In this study, the distribution of macrolide resistance mechanisms was determined for isolates of Streptococcus pneumoniae and Streptococcus pyogenes obtained from the PROTEKT 1999- 2000 study (a global, longitudinal study of the antibacterial susceptibility of bacterial pathogens associated with community-acquired lower respiratory tract infections). The global macrolide resistance mechanism distribution results for 1043 macrolide-resistant S. pneumoniae isolates collected from 25

D. J. Farrell; I. Morrissey; S. Bakker; D. Felmingham

2002-01-01

41

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

42

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

43

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

PubMed

Both Streptococcus pyogenes and Streptococcus pneumoniae are widely thought to rapidly die outside the human host, losing infectivity following desiccation in the environment. However, to date, all literature investigating the infectivity of desiccated streptococci has used broth-grown, planktonic populations. In this study, we examined the impact of biofilm formation on environmental survival of clinical and laboratory isolates of S. pyogenes and S. pneumoniae as both organisms are thought to colonize the human host as biofilms. Results clearly demonstrate that while planktonic cells that are desiccated rapidly lose viability both on hands and abiotic surfaces, such as plastic, biofilm bacteria remain viable over extended periods of time outside the host and remain infectious in a murine colonization model. To explore the level and extent of streptococcal fomite contamination that children might be exposed to naturally, direct bacteriologic cultures of items in a day care center were conducted, which demonstrated high levels of viable streptococci of both species. These findings raise the possibility that streptococci may survive in the environment and be transferred from person to person via fomites contaminated with oropharyngeal secretions containing biofilm streptococci. PMID:24371220

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

2014-03-01

44

Rapid Detection of Streptococcus pyogenes in Pleural Fluid Samples from Pediatric Patients with Empyema  

PubMed Central

A total of 120 pleural fluid specimens from 113 pediatric patients were tested using two rapid antigen detection assays for Streptococcus pyogenes. Results were compared to culture, Gram stain, and PCR results. Each rapid antigen assay detected 9 out of 10 (90%) PCR-positive samples, with 100% specificity. These antigen detection assays are useful to provide microbiological diagnosis of empyema caused by S. pyogenes. PMID:22622442

O'Leary, Amanda; Uhl, James R.; Patel, Robin; Shulman, Stanford T.

2012-01-01

45

Typing of Streptococcus pyogenes Strains Isolated from Throat Infections in the Region of Aachen, Germany  

Microsoft Academic Search

Background: Changes in the epidemiology of Streptococcus pyogenes infections may be associated with the introduction and reappearance of individual serotypes within a population.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and Methods: Typing of 216 consecutive isolates of S. pyogenes from patients with pharyngitis in the region of Aachen, Germany, was performed by sequencing the emm gene, slide-agglutination of the T-antigen and determining the serum opacity

C. M. Brandt; B. Spellerberg; M. Honscha; N. D. Truong; B. Hoevener; R. Lütticken

2001-01-01

46

Fluoroquinolone Resistance in Invasive Streptococcus pyogenes Isolates Due to Spontaneous Mutation and Horizontal Gene Transfer  

Microsoft Academic Search

Fluoroquinolone resistance in Streptococcus pyogenes has been described only anecdotally. In this study we describe two invasive ciprofloxacin-resistant S. pyogenes isolates (ciprofloxacin MICs, 8 mg\\/liter), one of which shows evidence of interspecies recombination. The quinolone resistance-determining regions of gyrA and parC were sequenced. In both isolates, there was no evidence for an efflux pump and no mutation in gyrA. Both

M. W. R. Pletz; L. McGee; C. A. Van Beneden; S. Petit; M. Bardsley; M. Barlow; K. P. Klugman

2006-01-01

47

Structure of the C-terminal domain of AspA (antigen I/II-family) protein from Streptococcus pyogenes  

PubMed Central

The pathogenic bacteria Streptococcus pyogenes can cause an array of diseases in humans, including moderate infections such as pharyngitis (strep throat) as well as life threatening conditions such as necrotizing fasciitis and puerperal fever. The antigen I/II family proteins are cell wall anchored adhesin proteins found on the surfaces of most oral streptococci and are involved in host colonization and biofilm formation. In the present study we have determined the crystal structure of the C2–3-domain of the antigen I/II type protein AspA from S. pyogenes M type 28. The structure was solved to 1.8 Å resolution and shows that the C2–3-domain is comprised of two structurally similar DEv-IgG motifs, designated C2 and C3, both containing a stabilizing covalent isopeptide bond. Furthermore a metal binding site is identified, containing a bound calcium ion. Despite relatively low sequence identity, interestingly, the overall structure shares high similarity to the C2–3-domains of antigen I/II proteins from Streptococcus gordonii and Streptococcus mutans, although certain parts of the structure exhibit distinct features. In summary this work constitutes the first step in the full structure determination of the AspA protein from S. pyogenes. PMID:24918040

Hall, Michael; Nylander, ?sa; Jenkinson, Howard F.; Persson, Karina

2014-01-01

48

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

49

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

PubMed

Streptococcus pyogenes is a human pathogen which causes a spectrum of diseases ranging from pharyngitis to rheumatic fever, necrotising fasciitis and toxic shock syndrome. Development of a vaccine for S. pyogenes has been confounded both by the diversity of the disease-causing serotypes and the spectre of inadvertently stimulating autoimmunity. The S. pyogenes nuclease A (SpnA) is a recently characterised virulence factor that is highly conserved across strains and expressed during human disease. Deletion of spnA from S. pyogenes results in reduced survival of bacteria in whole human blood and attenuated virulence in a mouse model of infection. Collectively these features suggest that SpnA has potential as a vaccine candidate for S. pyogenes. Mice vaccinated subcutaneously with single or multiple doses of recombinant SpnA emulsified in Incomplete Freund's Adjuvant developed a robust and durable IgG response, including neutralising activity, to this protein. However, vaccination with rSpnA conferred no advantage in terms of lesion development, disease symptoms or colonisation levels after a sub-lethal subcutaneous challenge with S. pyogenes. Anti-SpnA serum IgG responses and neutralising activity were increased in response to challenge, indicating that SpnA is expressed in vivo. SpnA is unlikely to be a suitable antigen for a vaccine against S. pyogenes. PMID:25119670

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

2015-04-01

50

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

PubMed Central

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 BB; Neves, Felipe PG; Barros, Rosana R

2014-01-01

51

Rgg Influences the Expression of Multiple Regulatory Loci To Coregulate Virulence Factor Expression in Streptococcus pyogenes  

Microsoft Academic Search

The human pathogen Streptococcus pyogenes secretes many proteins to the cell wall and extracellular environment that contribute to virulence. Rgg regulates the expression of several exoproteins including a cysteine protease (SPE B), a nuclease (MF-1), a putative nuclease (MF-3), and autolysin. The functional heterogeneity of Rgg-regulated exoproteins and the lack of a conserved regulatory motif in the promoter regions of

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

2002-01-01

52

Interspecies Recombination Occurs Frequently in Quinolone Resistance-Determining Regions of Clinical Isolates of Streptococcus pyogenes?  

PubMed Central

Fluoroquinolone resistance in Streptococcus pyogenes has been reported only anecdotally, but a recent Belgian surveillance study found a rate of nonsusceptibility of 5.4%. From an analysis of these isolates, we show that interspecies horizontal gene transfer within the parC quinolone resistance-determining region is a frequent phenomenon that might contribute to fluoroquinolone resistance. PMID:18765693

Duesberg, Christoph B.; Malhotra-Kumar, Surbhi; Goossens, Herman; McGee, Lesley; Klugman, Keith P.; Welte, Tobias; Pletz, Mathias W. R.

2008-01-01

53

Axillary Abscess Complicated by Venous Thrombosis: Identification of Streptococcus pyogenes by 16S PCR?  

PubMed Central

We report a case of an axillary abscess with Streptococcus pyogenes complicated by venous thrombosis. Bacterial etiology and typing were obtained by PCR and sequencing of the 16S rRNA and M-protein genes from abscess material. The bacterium was of serotype M41, and serology indicated that it had expressed procoagulant factors. PMID:20592151

Kahn, Fredrik; Linder, Adam; Petersson, Ann Cathrine; Christensson, Bertil; Rasmussen, Magnus

2010-01-01

54

Genetics of resistance to macrolide antibiotics and lincomycin in natural isolates of Streptococcus pyogenes  

Microsoft Academic Search

Of 5 clinically isolated strains of Streptococcus pyogenes, 3 showed high-level resistance to erythromycin and lincomycin that was inducible by subinhibitory concentrations of these drugs (IR strains) while 2 strains exhibited constitutive erythromycin and lincomycin resistance (CR strains) which was expressed without prior exposure to low drug concentrations. The CR strain 15346 showed spontaneous loss of resistance whereas resistance in

Horst Malke

1974-01-01

55

Production of recombinant streptokinase from Streptococcus pyogenes isolate and its potential for thrombolytic therapy  

PubMed Central

Objectives: To produce an effective recombinant streptokinase (rSK) from pathogenic Streptococcus pyogenes isolate in yeast, and evaluate its potential for thrombolytic therapy. Methods: This study was conducted from November 2012 to December 2013 at King Khalid University, Abha, Kingdom of Saudi Arabia (KSA). Throat swabs collected from 45 pharyngitis patients in Asser Central Hospital, Abha, KSA were used to isolate Streptococcus pyogenes. The bacterial DNA was used for amplification of the streptokinase gene (1200 bp). The gene was cloned and in vitro transcribed in an eukaryotic expression vector that was transformed into yeast Pichia pastoris SMD1168, and the rSK protein was purified and tested for its thrombolytic activity. Results: The Streptococcus pyogenes strain was isolated and its DNA nucleotide sequence revealed similarity to other Streptococcus pyogenes in the Gene bank. Sequencing of the amplified gene based on DNA nucleotide sequence revealed a SK gene closely related to other SK genes in the Gene bank. However, based on deduced amino acids sequence, the gene formed a separate cluster different from clusters formed by other examined genes, suggesting a new bacterial isolate and accordingly a new gene. The purified protein showed 82% clot lysis compared to a commercial SK (81%) at an enzyme concentration of 2000 U/ml. Conclusion: The present yeast rSK showed similar thrombolytic activity in vitro as that of a commercial SK, suggesting its potential for thrombolytic therapy and large scale production. PMID:25491213

Assiri, Abdullah S.; El-Gamal, Basiouny A.; Hafez, Elsayed E.; Haidara, Mohamed A.

2014-01-01

56

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

57

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

58

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

PubMed

Toxic shock syndrome caused by Streptococcus pyogenes (S. pyogenes) is a re-emerging infectious disease. Many virulence-associated proteins play important roles in its pathogenesis and the production of these proteins is controlled by many regulatory factors. CovS is one of the most important two-component sensor proteins in S. pyogenes, and it has been analyzed extensively. Our recent analyses revealed the existence of a transposon between covS and nrdR in several strains, and we speculated that this insertion has some importance. Hence, we examined the significances of the NrdR stand-alone regulator and DnaB, which is encoded by the gene located immediately downstream of nrdR in S. pyogenes infection. We established an nrdR-only knockout strain, and both nrdR and partial dnaB knockout strain. These established knockout strains exhibited a deteriorated response to H2 O2 exposure. nrdR and partial dnaB knockout strain was more easily killed by human polynuclear blood cells, but the nrdR-only knockout strain had no significant difference compared to wild type in contrast to the combined knockout strain. In addition, the mouse infection model experiment illustrated that nrdR and partial dnaB knockout strain, but not the nrdR-only knockout strain, was less virulent compared with the parental strain. These results suggest that DnaB is involved in response to host defense. PMID:25469586

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

2015-03-01

59

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

60

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

61

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

62

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

PubMed

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

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

2014-05-01

63

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

PubMed Central

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

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

2014-01-01

64

A Novel Role for Pro-Coagulant Microvesicles in the Early Host Defense against Streptococcus pyogenes  

PubMed Central

Previous studies have shown that stimulation of whole blood or peripheral blood mononuclear cells with bacterial virulence factors results in the sequestration of pro-coagulant microvesicles (MVs). These particles explore their clotting activity via the extrinsic and intrinsic pathway of coagulation; however, their pathophysiological role in infectious diseases remains enigmatic. Here we describe that the interaction of pro-coagulant MVs with bacteria of the species Streptococcus pyogenes is part of the early immune response to the invading pathogen. As shown by negative staining electron microscopy and clotting assays, pro-coagulant MVs bind in the presence of plasma to the bacterial surface. Fibrinogen was identified as a linker that, through binding to the M1 protein of S. pyogenes, allows the opsonization of the bacteria by MVs. Surface plasmon resonance analysis revealed a strong interaction between pro-coagulant MVs and fibrinogen with a KD value in the nanomolar range. When performing a mass-spectrometry-based strategy to determine the protein quantity, a significant up-regulation of the fibrinogen-binding integrins CD18 and CD11b on pro-coagulant MVs was recorded. Finally we show that plasma clots induced by pro-coagulant MVs are able to prevent bacterial dissemination and possess antimicrobial activity. These findings were confirmed by in vivo experiments, as local treatment with pro-coagulant MVs dampens bacterial spreading to other organs and improved survival in an invasive streptococcal mouse model of infection. Taken together, our data implicate that pro-coagulant MVs play an important role in the early response of the innate immune system in infectious diseases. PMID:23935504

Oehmcke, Sonja; Westman, Johannes; Malmström, Johan; Mörgelin, Matthias; Olin, Anders I.; Kreikemeyer, Bernd; Herwald, Heiko

2013-01-01

65

Macrolide Resistance in Streptococcus pyogenes Isolates from Throat Infections in the Region of Aachen, Germany  

Microsoft Academic Search

Macrolide-resistance was assessed in 216 consecutive Streptococcus pyogenes isolates from throat infections in the region of Aachen, Germany. Seventeen isolates were resistant to erythromycin: 12 isolates revealed a macrolide (M) phenotype and harbored mefA, and five strains expressed an inducible macrolide-lincosamide- streptogramin B (MLS B) phenotype of which four strains harbored ermA(TR) and one strain contained ermB(AM). Telithromycin (HMR 3647)

C. M. Brandt; M. Honscha; N. D. Truong; R. Holland; B. Hovener; A. Bryskier; R. Lutticken; R. R. Reinert

2001-01-01

66

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

67

Characterization of Two Novel Pyrogenic Toxin Superantigens Made by an Acute Rheumatic Fever Clone of Streptococcus pyogenes Associated with Multiple Disease Outbreaks  

PubMed Central

The pathogenesis of acute rheumatic fever (ARF) is poorly understood. We identified two contiguous bacteriophage genes, designated speL and speM, encoding novel inferred superantigens in the genome sequence of an ARF strain of serotype M18 group A streptococcus (GAS). speL and speM were located at the same genomic site in 33 serotype M18 isolates, and no nucleotide sequence diversity was observed in the 33 strains analyzed. Furthermore, the genes were absent in 13 non-M18 strains tested. These data indicate a recent acquisition event by a distinct clone of serotype M18 GAS. speL and speM were transcribed in vitro and upregulated in the exponential phase of growth. Purified SpeL and SpeM were pyrogenic and mitogenic for rabbit splenocytes and human peripheral blood mononuclear cells in picogram amounts. SpeL preferentially expanded human T cells expressing T-cell receptors V?1, V?5.1, and V?23, and SpeM had specificity for V?1 and V?23 subsets, indicating that both proteins had superantigen activity. SpeL was lethal in two animal models of streptococcal toxic shock, and SpeM was lethal in one model. Serologic studies indicated that ARF patients were exposed to serotype M18 GAS, SpeL, and SpeM. The data demonstrate that SpeL and SpeM are pyrogenic toxin superantigens and suggest that they may participate in the host-pathogen interactions in some ARF patients. PMID:12438391

Smoot, Laura M.; McCormick, John K.; Smoot, James C.; Hoe, Nancy P.; Strickland, Ian; Cole, Robert L.; Barbian, Kent D.; Earhart, Cathleen A.; Ohlendorf, Douglas H.; Veasy, L. George; Hill, Harry R.; Leung, Donald Y. M.; Schlievert, Patrick M.; Musser, James M.

2002-01-01

68

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

69

Sensitivity of Staphylococcus aureus and Streptococcus pyogenes isolated from skin infections in 1992 to antimicrobial agents.  

PubMed

We studied the efficacy of antimicrobial agents against Staphylococcus aureus (S. aureus) and Streptococcus pyogenes (S. pyogenes) isolated from skin infections in 1992. For S. aureus, we measured the minimum inhibitory concentrations (MICs) of the following 10 drugs: methicillin (DMPPC), cefaclor (CCL), gentamicin (GM), erythromycin (EM), clindamycin (CLDM), minocycline (MINO), vancomycin (VAN), fusidic acid (FA), ofloxacin (OFLX) and nadifloxacin (NDFX); for S. pyogenes, we determined the MICs of the following 9 drugs: ampicillin (ABPC), amoxicillin (AMPC), cefpodoxime proxetil (CPDX-PR), erythromycin (EM), clindamycin (CLDM), minocycline (MINO), norfloxacin (NFLX), of loxacin (OFLX) and nadifloxacin (NDFX). These drugs are frequently used to treat skin infections, either systemically or topically. NDFX is a new synthetic fluoroquinolone, recently developed for use as a topical acne medication in Japan. It is used NDFX for acne, but not for skin infections. There were no strains of S. aureus resistant to NDFX, VAN or FA. The resistance (> or = 12.5 micrograms/ml) of S. aureus was highest to GM and lowest to OFLX. Four strains of methicillin-resistant (> or = 12.5 micrograms/ml) S. aureus (MRSA) were found. In contrast, no resistant strains of S. pyogenes were found except to MINO. Only two strains of S. pyogenes were susceptible to MINO. The sensitivity of S. pyogenes to ABPC, AMPC, CPDX-PR, EM and CLDM was very good. All the strains were susceptible at a MIC below > or = 0.05 microgram/ml. However, the S. pyogenes strains were not very sensitive to the new quinolones, especially NFLX. We concluded that penicillins, cephalosporins and macrolides are still effective against streptococcal infections.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8056894

Nishijima, S; Namura, S; Kawai, S; Akamatsu, H; Asada, Y; Kawabata, S

1994-04-01

70

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

PubMed Central

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

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

2014-01-01

71

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

72

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. PMID:25620959

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

2014-01-01

73

Fluoroquinolone Resistance in Invasive Streptococcus pyogenes Isolates Due to Spontaneous Mutation and Horizontal Gene Transfer  

PubMed Central

Fluoroquinolone resistance in Streptococcus pyogenes has been described only anecdotally. In this study we describe two invasive ciprofloxacin-resistant S. pyogenes isolates (ciprofloxacin MICs, 8 mg/liter), one of which shows evidence of interspecies recombination. The quinolone resistance-determining regions of gyrA and parC were sequenced. In both isolates, there was no evidence for an efflux pump and no mutation in gyrA. Both isolates had an S79F mutation in parC that is known to confer fluoroquinolone resistance. In addition, a D91N mutation in parC, which is not related to fluoroquinolone resistance but is a feature of the parC sequence of Streptococcus dysgalactiae, was found in one isolate. The parC nucleotide sequence of that isolate showed greater diversity than that of S. pyogenes. A GenBank search and phylogenetic analysis suggest that this isolate acquired resistance by horizontal gene transfer from S. dysgalactiae. Statistical testing for recombination confirmed interspecies recombination of a 90-bp sequence containing the S79F mutation from S. dysgalactiae. For the other isolate, we could confirm that it acquired resistance by spontaneous mutation by identifying the susceptible ancestor in an outbreak setting. PMID:16495255

Pletz, M. W. R.; McGee, L.; Van Beneden, C. A.; Petit, S.; Bardsley, M.; Barlow, M.; Klugman, K. P.

2006-01-01

74

Fluoroquinolone resistance in invasive Streptococcus pyogenes isolates due to spontaneous mutation and horizontal gene transfer.  

PubMed

Fluoroquinolone resistance in Streptococcus pyogenes has been described only anecdotally. In this study we describe two invasive ciprofloxacin-resistant S. pyogenes isolates (ciprofloxacin MICs, 8 mg/liter), one of which shows evidence of interspecies recombination. The quinolone resistance-determining regions of gyrA and parC were sequenced. In both isolates, there was no evidence for an efflux pump and no mutation in gyrA. Both isolates had an S79F mutation in parC that is known to confer fluoroquinolone resistance. In addition, a D91N mutation in parC, which is not related to fluoroquinolone resistance but is a feature of the parC sequence of Streptococcus dysgalactiae, was found in one isolate. The parC nucleotide sequence of that isolate showed greater diversity than that of S. pyogenes. A GenBank search and phylogenetic analysis suggest that this isolate acquired resistance by horizontal gene transfer from S. dysgalactiae. Statistical testing for recombination confirmed interspecies recombination of a 90-bp sequence containing the S79F mutation from S. dysgalactiae. For the other isolate, we could confirm that it acquired resistance by spontaneous mutation by identifying the susceptible ancestor in an outbreak setting. PMID:16495255

Pletz, M W R; McGee, L; Van Beneden, C A; Petit, S; Bardsley, M; Barlow, M; Klugman, K P

2006-03-01

75

Fulminant necrotizing soft tissue infections due to Streptococcus pyogens  

Microsoft Academic Search

Aim-Background  Necrotizing soft tissue infection (NSTI) is a rapidly progressive soft tissue infection with high morbidity and mortality\\u000a rates. It has an incidence of approximately 1000 cases per year in the United States. Severe invasive group A Streptococcus\\u000a infections associated with bacteraemia and septic shock have occurred with increasing incidence. Early recognition and prompt\\u000a medical and surgical intervention are necessary to

Ch. Kontovounisios; M. Korontzi; V. Armoutidis; T. Papakonstantinou; G. Sgourakis; S. Lanitis

2010-01-01

76

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

PubMed

While Streptococcus pyogenes is consistently susceptible toward penicillin, therapeutic failure of penicillin treatment has been reported repeatedly and a considerable number of patients exhibit allergic reactions to this substance. At the same time, streptococcal resistance to alternative antibiotics, e.g., macrolides, has increased. Taken together, these facts demand the development of novel therapeutic strategies. In this study, S. pyogenes growth was inhibited by application of peptide-conjugated antisense-peptide nucleic acids (PNAs) specific for the essential gyrase A gene (gyrA). Thereby, HIV-1 Tat peptide-coupled PNAs were more efficient inhibitors of streptococcal growth as compared with (KFF)3K-coupled PNAs. Peptide-anti-gyrA PNAs decreased the abundance of gyrA transcripts in S. pyogenes. Growth inhibition by antisense interference was enhanced by combination of peptide-coupled PNAs with protein-level inhibitors. Antimicrobial synergy could be detected with levofloxacin and novobiocin, targeting the gyrase enzyme, and with spectinomycin, impeding ribosomal function. The prospective application of carrier peptide-coupled antisense PNAs in S. pyogenes covers the use as an antimicrobial agent and the employment as a knock-down strategy for the investigation of virulence factor function.Molecular Therapy-Nucleic Acids (2013) 2, e132; doi:10.1038/mtna.2013.62; published online 5 November 2013. PMID:24193033

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

2013-01-01

77

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

78

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

PubMed Central

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

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

2011-01-01

79

Innate Immune Response to Streptococcus pyogenes Depends on the Combined Activation of TLR13 and TLR2  

PubMed Central

Innate immune recognition of the major human-specific Gram-positive pathogen Streptococcus pyogenes is not understood. Here we show that mice employ Toll-like receptor (TLR) 2- and TLR13-mediated recognition of S. pyogenes. These TLR pathways are non-redundant in the in vivo context of animal infection, but are largely redundant in vitro, as only inactivation of both of them abolishes inflammatory cytokine production by macrophages and dendritic cells infected with S. pyogenes. Mechanistically, S. pyogenes is initially recognized in a phagocytosis-independent manner by TLR2 and subsequently by TLR13 upon internalization. We show that the TLR13 response is specifically triggered by S. pyogenes rRNA and that Tlr13?/? cells respond to S. pyogenes infection solely by engagement of TLR2. TLR13 is absent from humans and, remarkably, we find no equivalent route for S. pyogenes RNA recognition in human macrophages. Phylogenetic analysis reveals that TLR13 occurs in all kingdoms but only in few mammals, including mice and rats, which are naturally resistant against S. pyogenes. Our study establishes that the dissimilar expression of TLR13 in mice and humans has functional consequences for recognition of S. pyogenes in these organisms. PMID:25756897

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

2015-01-01

80

Antibacterial Activity of the Contact and Complement Systems Is Blocked by SIC, a Protein Secreted by Streptococcus pyogenes*  

PubMed Central

Recent studies have shown that activation of complement and contact systems results in the generation of antibacterial peptides. Streptococcus pyogenes, a major bacterial pathogen in humans, exists in >100 different serotypes due to sequence variation in the surface-associated M protein. Cases of invasive and life-threatening S. pyogenes infections are commonly associated with isolates of the M1 serotype, and in contrast to the large majority of M serotypes, M1 isolates all secrete the SIC protein. Here, we show that SIC interferes with the activation of the contact system and blocks the activity of antibacterial peptides generated through complement and contact activation. This effect promotes the growth of S. pyogenes in human plasma, and in a mouse model of S. pyogenes sepsis, SIC enhances bacterial dissemination, results which help explain the high frequency of severe S. pyogenes infections caused by isolates of the M1 serotype. PMID:21068386

Frick, Inga-Maria; Shannon, Oonagh; ?kesson, Per; Mörgelin, Matthias; Collin, Mattias; Schmidtchen, Artur; Björck, Lars

2011-01-01

81

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

82

Streptococcus pneumoniaeandStreptococcus pyogenesResistant to Macrolides but Sensitive to Clindamycin: a Common Resistance Pattern Mediated by an Efflux System  

Microsoft Academic Search

Macrolide-resistant Streptococcus pyogenes isolates from Finland, Australia, and the United Kingdom and, more recently,Streptococcus pneumoniaeandS. pyogenesstrains from the United States were shown to have an unusual resistance pattern to macrolides, lincosamides, and streptogramin B antibiotics. This pattern, re- ferred to as M resistance, consists of susceptibility to clindamycin and streptogramin B antibiotics but resistance to 14- and 15-membered macrolides. An

JOYCE SUTCLIFFE; AMELIA TAIT-KAMRADT; ANDLILLIAN WONDRACK

1996-01-01

83

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

PubMed Central

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

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

2014-01-01

84

Streptococcus pyogenes Arginine and Citrulline Catabolism Promotes Infection and Modulates Innate Immunity  

PubMed Central

A bacterium's ability to acquire nutrients from its host during infection is an essential component of pathogenesis. For the Gram-positive pathogen Streptococcus pyogenes, catabolism of the amino acid arginine via the arginine deiminase (ADI) pathway supplements energy production and provides protection against acid stress in vitro. Its expression is enhanced in murine models of infection, suggesting an important role in vivo. To gain insight into the function of the ADI pathway in pathogenesis, the virulence of mutants defective in each of its enzymes was examined. Mutants unable to use arginine (?ArcA) or citrulline (?ArcB) were attenuated for carriage in a murine model of asymptomatic mucosal colonization. However, in a murine model of inflammatory infection of cutaneous tissue, the ?ArcA mutant was attenuated but the ?ArcB mutant was hyperattenuated, revealing an unexpected tissue-specific role for citrulline metabolism in pathogenesis. When mice defective for the arginine-dependent production of nitric oxide (iNOS?/?) were infected with the ?ArcA mutant, cutaneous virulence was rescued, demonstrating that the ability of S. pyogenes to utilize arginine was dispensable in the absence of nitric oxide-mediated innate immunity. This work demonstrates the importance of arginine and citrulline catabolism and suggests a novel mechanism of virulence by which S. pyogenes uses its metabolism to modulate innate immunity through depletion of an essential host nutrient. PMID:24144727

Cusumano, Zachary T.; Watson, Michael E.

2014-01-01

85

Genome Sequence of a Nephritogenic and Highly Transformable M49 Strain of Streptococcus pyogenes? †  

PubMed Central

The 1,815,783-bp genome of a serotype M49 strain of Streptococcus pyogenes (group A streptococcus [GAS]), strain NZ131, has been determined. This GAS strain (FCT type 3; emm pattern E), originally isolated from a case of acute post-streptococcal glomerulonephritis, is unusually competent for electrotransformation and has been used extensively as a model organism for both basic genetic and pathogenesis investigations. As with the previously sequenced S. pyogenes genomes, three unique prophages are a major source of genetic diversity. Two clustered regularly interspaced short palindromic repeat (CRISPR) regions were present in the genome, providing genetic information on previous prophage encounters. A unique cluster of genes was found in the pathogenicity island-like emm region that included a novel Nudix hydrolase, and, further, this cluster appears to be specific for serotype M49 and M82 strains. Nudix hydrolases eliminate potentially hazardous materials or prevent the unbalanced accumulation of normal metabolites; in bacteria, these enzymes may play a role in host cell invasion. Since M49 S. pyogenes strains have been known to be associated with skin infections, the Nudix hydrolase and its associated genes may have a role in facilitating survival in an environment that is more variable and unpredictable than the uniform warmth and moisture of the throat. The genome of NZ131 continues to shed light upon the evolutionary history of this human pathogen. Apparent horizontal transfer of genetic material has led to the existence of highly variable virulence-associated regions that are marked by multiple rearrangements and genetic diversification while other regions, even those associated with virulence, vary little between genomes. The genome regions that encode surface gene products that will interact with host targets or aid in immune avoidance are the ones that display the most sequence diversity. Thus, while natural selection favors stability in much of the genome, it favors diversity in these regions. PMID:18820018

McShan, W. Michael; Ferretti, Joseph J.; Karasawa, Tadahiro; Suvorov, Alexander N.; Lin, Shaoping; Qin, Biafang; Jia, Honggui; Kenton, Steve; Najar, Fares; Wu, Hongmin; Scott, Julie; Roe, Bruce A.; Savic, Dragutin J.

2008-01-01

86

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

PubMed

A scarlet fever outbreak caused by Streptococcus pyogenes occurred in China in 2011. To determine the genomic features of the outbreak strains, we deciphered genomes of two strains isolated from the regions with the highest incidence rates. The sequences will provide valuable information for comprehensive study of mechanisms related to this outbreak. PMID:23045496

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

2012-11-01

87

M-protein and other intrinsic virulence factors of Streptococcus pyogenes are encoded on an ancient pathogenicity island  

Microsoft Academic Search

BACKGROUND: The increasing number of completely sequenced bacterial genomes allows comparing their architecture and genetic makeup. Such new information highlights the crucial role of lateral genetic exchanges in bacterial evolution and speciation. RESULTS: Here we analyzed the twelve sequenced genomes of Streptococcus pyogenes by a naïve approach that examines the preferential nucleotide usage along the chromosome, namely the usage of

Alexandre Panchaud; Lionel Guy; François Collyn; Marisa Haenni; Masanobu Nakata; Andreas Podbielski; Philippe Moreillon; Claude-Alain H Roten

2009-01-01

88

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

PubMed Central

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

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

2012-01-01

89

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

90

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

PubMed

Streptococcus pyogenes is the most common bacterial pathogen causing pharyngotonsillitis, and also can lead to diseases such as otitis media, impetigo, necrotizing fasciitis, bacteremia, sepsis and toxic shock-like syndrome. M protein encoded by emm gene is an important virulence factor of S.pyogenes and it is used for genotyping in epidemiological studies. The aims of this study were to determine the M protein types of group A streptococci (GAS) by using emm gene sequence analysis method, to compare the M types in terms of analogy with the vaccine in development and to determine the antibiotic susceptibilities of the isolates. A total of 35 GAS strains isolated from various clinical specimens in our laboratory were included in the study. Strains growing in blood culture were considered as invasive, strains growing in throat and abscess cultures were considered as non-invasive. The isolates have been identified by conventional methods and 16S rRNA sequence analysis at species level. emm genotyping of strains identified as S.pyogenes, was performed by PCR method as proposed by the CDC. Amplicons were obtained and sequenced in 23 out of 35 isolates. The results were compared with CDC emm sequence database. Antibiotic susceptibility of the isolates was performed by agar dilution method and evaluated as recommended by CLSI. Twenty-three out of 35 isolates could be typed and 15 different emm genotypes were detected. The most common emm types were emm1 (22%), emm89 (13%), emm18 (9%) and emm19 (9%). The detection rate of other emm types (emm5, 12, 14, 17, 26, 29, 37, 74, 78, 92, 99) was 47%. Types emm1, 12, 19, 74, 89 and 99 were observed in strains isolated from blood cultures. It was detected that nine of the 15 (60%) emm types are within the contents of 26 valent vaccine (emm 1, 5, 12, 14, 18, 19, 29, 89, 92). It was also observed that 17 (74%) of the 23 cases were infected by vaccine types and the four emm types (emm1, 12, 19, 89) identified in blood samples were among the vaccine types. All of the strains were found susceptible to penicillin, ampicillin, erythromycin, lincomycin, gentamicin, chloramphenicol, vancomycin and linezolid, however six isolates were resistant to levofloxacin (MIC= 4 and 16 µg/ml) and one isolate was resistant to tetracycline (MIC= 16 µg/ml). In conclusion, this preliminary local study with limited number of invasive and non-invasive S.pyogenes isolates, emphasized the need for larger scale multi-center studies to determine the analogy and efficacy of the vaccine in development. PMID:23621731

Arslan, U?ur; Orya??n, Erman; Eskin, Zeynep; Türk Da??, Hatice; F?nd?k, Duygu; Tuncer, Inci; Bozdo?an, Bülent

2013-04-01

91

Epidemiology of Invasive Streptococcus pyogenes Infections in France in 2007 ?  

PubMed Central

Invasive group A streptococcal (GAS) infections cause significant morbidity and mortality. A national survey was initiated to assess the burden of invasive GAS infections in France, describe their clinical characteristics, and assess the molecular characteristics of GAS strains responsible for these infections. The survey was conducted in 194 hospitals, accounting for 51% of acute care hospital admissions in France. Clinical data, predisposing factors, and demographic data were obtained, and all GAS isolates were emm sequence typed. We identified 664 cases of invasive GAS infections, with an annual incidence of 3.1 per 100,000 population. The case-fatality ratio was 14% and rose to 43% in the case of streptococcal toxic shock syndrome. Bacteremia without identified focus (22%) and skin/soft tissue infections (30%) were the most frequent clinical presentations. Necrotizing fasciitis was frequent in adults (18%) and uncommon in children (3%). The 3 predominant emm types were emm1, emm89, and emm28, accounting for 33%, 16%, and 10% of GAS isolates, respectively. The emm1 type was associated with fatal outcomes and was more frequent in children than in adults. Six clusters of cases were identified, with each cluster involving 2 invasive cases due to GAS strains which shared identical GAS emm sequence types. Four clusters of cases involved eight postpartum infections, one family cluster involved a mother and child, and one cluster involved two patients in a nursing home. Invasive GAS infection is one of the most severe bacterial diseases in France, particularly in persons aged ?50 years or when associated with toxic shock syndrome. PMID:21976764

Lepoutre, A.; Doloy, A.; Bidet, P.; Leblond, A.; Perrocheau, A.; Bingen, E.; Trieu-Cuot, P.; Bouvet, A.; Poyart, C.; Lévy-Bruhl, D.

2011-01-01

92

Structural and functional characterization of Streptococcus pyogenes Cas2 protein under different pH conditions.  

PubMed

Clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins constitute an RNA-guided microbial defense system against invading foreign genetic materials. Cas2 is one of the core Cas proteins found universally in all the subtypes of CRISPR-Cas systems and is required for incorporating new spacers into CRISPR loci. Cas2 homologues from different CRISPR-Cas subtypes were characterized previously as metal-dependent nucleases with different substrate preferences, and it was proposed that a pH-dependent conformational change mediates metal binding and catalysis. Here, we report the crystal structures of Streptococcus pyogenes Cas2 at three different pHs (5.6, 6.5, and 7.5), as well as the results of its nuclease activity assay against double-stranded DNAs at varying pHs (6.0-9.0). Although S. pyogenes Cas2 exhibited strongly pH-dependent catalytic activity, there was no significant conformational difference among the three crystal structures. However, structural comparisons with other Cas2 homologues revealed structural variability and the flexible nature of its putative hinge regions, supporting the hypothesis that conformational switching is important for catalysis. Taken together, our results confirm that Cas2 proteins have pH-dependent nuclease activity against double-stranded DNAs, and provide indirect structural evidence for their conformational changes. PMID:25079131

Ka, Donghyun; Kim, Dayoun; Baek, Gyeongyun; Bae, Euiyoung

2014-08-15

93

SpeB of Streptococcus pyogenes Differentially Modulates Antibacterial and Receptor Activating Properties of Human Chemokines  

PubMed Central

Background CXC chemokines are induced by inflammatory stimuli in epithelial cells and some, like MIG/CXCL9, IP–10/CXCL10 and I–TAC/CXCL11, are antibacterial for Streptococcus pyogenes. Methodology/Principal Findings SpeB from S. pyogenes degrades a wide range of chemokines (i.e. IP10/CXCL10, I-TAC/CXCL11, PF4/CXCL4, GRO?/CXCL1, GRO?/CXCL2, GRO?/CXCL3, ENA78/CXCL5, GCP-2/CXCL6, NAP-2/CXCL7, SDF-1/CXCL12, BCA-1/CXCL13, BRAK/CXCL14, SRPSOX/CXCL16, MIP-3?/CCL20, Lymphotactin/XCL1, and Fractalkine/CX3CL1), has no activity on IL-8/CXCL8 and RANTES/CCL5, partly degrades SRPSOX/CXCL16 and MIP-3?/CCL20, and releases a 6 kDa CXCL9 fragment. CXCL10 and CXCL11 loose receptor activating and antibacterial activities, while the CXCL9 fragment does not activate the receptor CXCR3 but retains its antibacterial activity. Conclusions/Significance SpeB destroys most of the signaling and antibacterial properties of chemokines expressed by an inflamed epithelium. The exception is CXCL9 that preserves its antibacterial activity after hydrolysis, emphasizing its role as a major antimicrobial on inflamed epithelium. PMID:19274094

Egesten, Arne; Olin, Anders I.; Linge, Helena M.; Yadav, Manisha; Mörgelin, Matthias; Karlsson, Anna; Collin, Mattias

2009-01-01

94

Intramolecular Isopeptide Bonds Give Thermodynamic and Proteolytic Stability to the Major Pilin Protein of Streptococcus pyogenes*  

PubMed Central

The pili expressed by Streptococcus pyogenes and certain other Gram-positive bacterial pathogens are based on a polymeric backbone in which individual pilin subunits are joined end-to-end by covalent isopeptide bonds through the action of sortase enzymes. The crystal structure of the major pilin of S. pyogenes, Spy0128, revealed that each domain of the two domain protein contained an intramolecular isopeptide bond cross-link joining a Lys side chain to an Asn side chain. In the present work, mutagenesis was used to create mutant proteins that lacked either one isopeptide bond (E117A, N168A, and E258A mutants) or both isopeptide bonds (E117A/E258A). Both the thermal stability and proteolytic stability of Spy0128 were severely compromised by loss of the isopeptide bonds. Unfolding experiments, monitored by circular dichroism, revealed a transition temperature Tm of 85 °C for the wild type protein. In contrast, mutants with only one isopeptide bond showed biphasic unfolding, with the domain lacking an isopeptide bond having a Tm that was ?30 °C lower than the unaltered domain. High resolution crystal structures of the E117A and N168A mutants showed that the loss of an isopeptide bond did not change the overall pilin structure but caused local disturbance of the protein core that was greater for E117A than for N168A. These effects on stability appear also to be important for pilus assembly. PMID:19497855

Kang, Hae Joo; Baker, Edward N.

2009-01-01

95

Structure and activity of the Streptococcus pyogenes family GH1 6-phospho-?-glucosidase SPy1599.  

PubMed

The group A streptococcus Streptococcus pyogenes is the causative agent of a wide spectrum of invasive infections, including necrotizing fasciitis, scarlet fever and toxic shock syndrome. In the context of its carbohydrate chemistry, it is interesting that S. pyogenes (in this work strain M1 GAS SF370) displays a spectrum of oligosaccharide-processing enzymes that are located in close proximity on the genome but that the in vivo function of these proteins remains unknown. These proteins include different sugar transporters (SPy1593 and SPy1595), both GH125 ?-1,6- and GH38 ?-1,3-mannosidases (SPy1603 and SPy1604), a GH84 ?-hexosaminidase (SPy1600) and a putative GH2 ?-galactosidase (SPy1586), as well as SPy1599, a family GH1 `putative ?-glucosidase'. Here, the solution of the three-dimensional structure of SPy1599 in a number of crystal forms complicated by unusual crystallographic twinning is reported. The structure is a classical (?/?)(8)-barrel, consistent with CAZy family GH1 and other members of the GH-A clan. SPy1599 has been annotated in sequence depositions as a ?-glucosidase (EC 3.2.1.21), but no such activity could be found; instead, three-dimensional structural overlaps with other enzymes of known function suggested that SPy1599 contains a phosphate-binding pocket in the active site and has possible 6-phospho-?-glycosidase activity. Subsequent kinetic analysis indeed showed that SPy1599 has 6-phospho-?-glucosidase (EC 3.2.1.86) activity. These data suggest that SPy1599 is involved in the intracellular degradation of 6-phosphoglycosides, which are likely to originate from import through one of the organism's many phosphoenolpyruvate phosphotransfer systems (PEP-PTSs). PMID:23275159

Stepper, Judith; Dabin, Jerome; Eklof, Jens M; Thongpoo, Preeyanuch; Kongsaeree, Prachumporn; Taylor, Edward J; Turkenburg, Johan P; Brumer, Harry; Davies, Gideon J

2013-01-01

96

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

97

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

PubMed

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

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

2014-06-27

98

Rapid identification of the animal pathogens Streptococcus uberis and Arcanobacterium pyogenes by fluorescence in situ hybridization (FISH).  

PubMed

Fluorescence in situ hybridization (FISH) has been reported to be an easy and rapid identification method for many human pathogens, but applications for common veterinary pathogens are lacking. Gene probes for FISH of the animal pathogens Streptococcus uberis and Arcanobacterium pyogenes were designed to provide probes for a specific identification of these bacteria from cultures. Specific FISH probes for these species have so far not been published. Both probes recognized all isolates of the target species correctly. With the S. uberis probe SUB 196 no false-positive results were obtained for reference strains as well as for clinical isolates. Probe APYO 183 for A. pyogenes produced false-positive reactions with so far rarely described Arcanobacterium species from animals at standard hybridization conditions. In order to avoid any incorrect classifications of microorganisms as A. pyogenes, two non-labelled competitor probes were designed and successfully evaluated. PMID:22033042

Werckenthin, Christiane; Gey, Annerose; Straubinger, Reinhard K; Poppert, Sven

2012-05-01

99

Comparison of emm Typing and Ribotyping with Three Restriction Enzymes To Characterize Clinical Isolates of Streptococcus pyogenes  

Microsoft Academic Search

A total of 336 Streptococcus pyogenes isolates recently recovered from patients with pharyngitis from 13 countries were characterized by emm typing and riboprinting using an automated Riboprinter (Dupont\\/ Qualicon) based on the patterns produced by three restriction enzymes, EcoRI, PstI, and HindIII. Three enzymes were necessary to increase the discrimination of ribogroups formed by each enzyme. A total of 40

Stella Z. Doktor; Jill M. Beyer; Robert K. Flamm; Virginia D. Shortridge

2005-01-01

100

Epidemiology and Molecular Characterization of Streptococcus pyogenes Recovered from Scarlet Fever Patients in Central Taiwan from 1996 to 1999  

Microsoft Academic Search

One hundred seventy-nine Streptococcus pyogenes isolates recovered from scarlet fever patients from 1996 to 1999 in central Taiwan were characterized by emm, Vir, and pulsed-field gel electrophoresis (PFGE) typing methods. The protocols for Vir and PFGE typing were standardized. A database of the DNA fingerprints for the isolates was established. Nine emm or emm-like genes, 19 Vir patterns, and 26

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

2004-01-01

101

Phenotypes and Genotypes of Erythromycin-Resistant Streptococcus pyogenes Strains in Italy and Heterogeneity of Inducibly Resistant Strains  

Microsoft Academic Search

A total of 387 clinical strains of erythromycin-resistant (MIC, >1 mg\\/ml) Streptococcus pyogenes, all isolated in Italian laboratories from 1995 to 1998, were examined. By the erythromycin-clindamycin double-disk test, 203 (52.5%) strains were assigned to the recently described M phenotype, 120 (31.0%) were assigned to the inducible macrolide, lincosamide, and streptogramin B resistance (iMLS) phenotype, and 64 (16.5%) were assigned

ELEONORA GIOVANETTI; MARIA PIA MONTANARI; MARINA MINGOIA; PIETRO EMANUELE VARALDO

1999-01-01

102

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

Microsoft Academic Search

The extracellular cysteine protease from Streptococcus pyogenes is a virulence factor that plays a significant role in host-pathogen interaction. Streptococcal protease is expressed as an inactive 40-kDa precursor that is autocatalytically converted into a 28-kDa mature (active) enzyme. Replacement of the single cysteine residue involved in formation of the enzyme active site with serine (C192S mutation) abolished detectable proteolytic activity

YURY V. MATSUKA; SUBRAMONIA PILLAI; SIDDESWAR GUBBA; JAMES M. MUSSER

1999-01-01

103

Antagonistic Rgg Regulators Mediate Quorum Sensing via Competitive DNA Binding in Streptococcus pyogenes  

PubMed Central

ABSTRACT Recent studies have established the fact that multiple members of the Rgg family of transcriptional regulators serve as key components of quorum sensing (QS) pathways that utilize peptides as intercellular signaling molecules. We previously described a novel QS system in Streptococcus pyogenes which utilizes two Rgg-family regulators (Rgg2 and Rgg3) that respond to neighboring signaling peptides (SHP2 and SHP3) to control gene expression and biofilm formation. We have shown that Rgg2 is a transcriptional activator of target genes, whereas Rgg3 represses expression of these genes, and that SHPs function to activate the QS system. The mechanisms by which Rgg proteins regulate both QS-dependent and QS-independent processes remain poorly defined; thus, we sought to further elucidate how Rgg2 and Rgg3 mediate gene regulation. Here we provide evidence that S. pyogenes employs a unique mechanism of direct competition between the antagonistic, peptide-responsive proteins Rgg2 and Rgg3 for binding at target promoters. The highly conserved, shared binding sites for Rgg2 and Rgg3 are located proximal to the ?35 nucleotide in the target promoters, and the direct competition between the two regulators results in concentration-dependent, exclusive occupation of the target promoters that can be skewed in favor of Rgg2 in vitro by the presence of SHP. These results suggest that exclusionary binding of target promoters by Rgg3 may prevent Rgg2 binding under SHP-limiting conditions, thereby preventing premature induction of the quorum sensing circuit. PMID:23188510

LaSarre, Breah; Aggarwal, Chaitanya; Federle, Michael J.

2012-01-01

104

Self-association of streptococcus pyogenes collagen-like constructs into higher order structures.  

PubMed

A number of bacterial collagen-like proteins with Gly as every third residue and a high Pro content have been observed to form stable triple-helical structures despite the absence of hydroxyproline (Hyp). Here, the high yield cold-shock expression system is used to obtain purified recombinant collagen-like protein (V-CL) from Streptococcus pyogenes containing an N-terminal globular domain V followed by the collagen triple-helix domain CL and the modified construct with two tandem collagen domains V-CL-CL. Both constructs and their isolated collagenous domains form stable triple-helices characterized by very sharp thermal transitions at 35-37 degrees C and by high values of calorimetric enthalpy. Procedures for the formation of collagen SLS crystallites lead to parallel arrays of in register V-CL-CL molecules, as well as centrosymmetric arrays of dimers joined at their globular domains. At neutral pH and high concentrations, the bacterial constructs all show a tendency towards aggregation. The isolated collagen domains, CL and CL-CL, form units of diameter 4-5 nm which bundle together and twist to make larger fibrillar structures. Thus, although this S. pyogenes collagen-like protein is a cell surface protein with no indication of participation in higher order structure, the triple-helix domain has the potential of forming fibrillar structures even in the absence of hydroxyproline. The formation of fibrils suggests bacterial collagen proteins may be useful for biomaterials and tissue engineering applications. PMID:19472339

Yoshizumi, Ayumi; Yu, Zhuoxin; Silva, Teresita; Thiagarajan, Geetha; Ramshaw, John A M; Inouye, Masayori; Brodsky, Barbara

2009-06-01

105

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

PubMed Central

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

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

2013-01-01

106

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

PubMed

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

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

2014-12-01

107

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

108

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

PubMed Central

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

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

2012-01-01

109

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

PubMed Central

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

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

2013-01-01

110

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

111

Crystal Structures of ?1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes  

PubMed Central

L-Proline is an amino acid that plays an important role in proteins uniquely contributing to protein folding, structure, and stability, and this amino acid serves as a sequence-recognition motif. Proline biosynthesis can occur via two pathways, one from glutamate and the other from arginine. In both pathways, the last step of biosynthesis, the conversion of ?1-pyrroline-5-carboxylate (P5C) to L-proline, is catalyzed by ?1-pyrroline-5-carboxylate reductase (P5CR) using NAD(P)H as a cofactor. We have determined the first crystal structure of P5CR from two human pathogens, Neisseria meningitides and Streptococcus pyogenes, at 2.0Å and 2.15Å resolution, respectively. The catalytic unit of P5CR is a dimer composed of two domains, but the biological unit seems to be species-specific. The N-terminal domain of P5CR is an ?/?/? sandwich, a Rossmann fold. The C-terminal dimerization domain is rich in ?-helices and shows domain swapping. Comparison of the native structure of P5CR to structures complexed with L-proline and NADP+ in two quite different primary sequence backgrounds provides unique information about key functional features: the active site and the catalytic mechanism. The inhibitory L-proline has been observed in the crystal structure. PMID:16233902

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

2009-01-01

112

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

113

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

114

Type I Interferon Production Induced by Streptococcus pyogenes-Derived Nucleic Acids Is Required for Host Protection  

PubMed Central

Streptococcus pyogenes is a Gram-positive human pathogen that is recognized by yet unknown pattern recognition receptors (PRRs). Engagement of these receptor molecules during infection with S. pyogenes, a largely extracellular bacterium with limited capacity for intracellular survival, causes innate immune cells to produce inflammatory mediators such as TNF, but also type I interferon (IFN). Here we show that signaling elicited by type I IFNs is required for successful defense of mice against lethal subcutaneous cellulitis caused by S. pyogenes. Type I IFN signaling was accompanied with reduced neutrophil recruitment to the site of infection. Mechanistic analysis revealed that macrophages and conventional dendritic cells (cDCs) employ different signaling pathways leading to IFN-beta production. Macrophages required IRF3, STING, TBK1 and partially MyD88, whereas in cDCs the IFN-beta production was fully dependent on IRF5 and MyD88. Furthermore, IFN-beta production by macrophages was dependent on the endosomal delivery of streptococcal DNA, while in cDCs streptococcal RNA was identified as the IFN-beta inducer. Despite a role of MyD88 in both cell types, the known IFN-inducing TLRs were individually not required for generation of the IFN-beta response. These results demonstrate that the innate immune system employs several strategies to efficiently recognize S. pyogenes, a pathogenic bacterium that succeeded in avoiding recognition by the standard arsenal of TLRs. PMID:21625574

Gratz, Nina; Hartweger, Harald; Matt, Ulrich; Kratochvill, Franz; Janos, Marton; Sigel, Stefanie; Drobits, Barbara; Li, Xiao-Dong; Knapp, Sylvia; Kovarik, Pavel

2011-01-01

115

Type I interferon production induced by Streptococcus pyogenes-derived nucleic acids is required for host protection.  

PubMed

Streptococcus pyogenes is a Gram-positive human pathogen that is recognized by yet unknown pattern recognition receptors (PRRs). Engagement of these receptor molecules during infection with S. pyogenes, a largely extracellular bacterium with limited capacity for intracellular survival, causes innate immune cells to produce inflammatory mediators such as TNF, but also type I interferon (IFN). Here we show that signaling elicited by type I IFNs is required for successful defense of mice against lethal subcutaneous cellulitis caused by S. pyogenes. Type I IFN signaling was accompanied with reduced neutrophil recruitment to the site of infection. Mechanistic analysis revealed that macrophages and conventional dendritic cells (cDCs) employ different signaling pathways leading to IFN-beta production. Macrophages required IRF3, STING, TBK1 and partially MyD88, whereas in cDCs the IFN-beta production was fully dependent on IRF5 and MyD88. Furthermore, IFN-beta production by macrophages was dependent on the endosomal delivery of streptococcal DNA, while in cDCs streptococcal RNA was identified as the IFN-beta inducer. Despite a role of MyD88 in both cell types, the known IFN-inducing TLRs were individually not required for generation of the IFN-beta response. These results demonstrate that the innate immune system employs several strategies to efficiently recognize S. pyogenes, a pathogenic bacterium that succeeded in avoiding recognition by the standard arsenal of TLRs. PMID:21625574

Gratz, Nina; Hartweger, Harald; Matt, Ulrich; Kratochvill, Franz; Janos, Marton; Sigel, Stefanie; Drobits, Barbara; Li, Xiao-Dong; Knapp, Sylvia; Kovarik, Pavel

2011-05-01

116

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

PubMed

The linkage between the macrolide efflux gene mef(I) and the chloramphenicol inactivation gene catQ was first described in Streptococcus pneumoniae (strain Spn529), where the two genes are located in a module designated IQ element. Subsequently, two different defective IQ elements were detected in Streptococcus pyogenes (strains Spy029 and Spy005). The genetic elements carrying the three IQ elements were characterized, and all were found to be Tn5253 family integrative and conjugative elements (ICEs). The ICE from S. pneumoniae (ICESpn529IQ) was sequenced, whereas the ICEs from S. pyogenes (ICESpy029IQ and ICESpy005IQ, the first Tn5253-like ICEs reported in this species) were characterized by PCR mapping, partial sequencing, and restriction analysis. ICESpn529IQ and ICESpy029IQ were found to share the intSp 23FST81 integrase gene and an identical Tn916 fragment, whereas ICESpy005IQ has int5252 and lacks Tn916. All three ICEs were found to lack the linearized pC194 plasmid that is usually associated with Tn5253-like ICEs, and all displayed a single copy of a toxin-antitoxin operon that is typically contained in the direct repeats flanking the excisable pC194 region when this region is present. Two different insertion sites of the IQ elements were detected, one in ICESpn529IQ and ICESpy029IQ, and another in ICESpy005IQ. The chromosomal integration of the three ICEs was site specific, depending on the integrase (intSp 23FST81 or int5252). Only ICESpy005IQ was excised in circular form and transferred by conjugation. By transformation, mef(I) and catQ were cotransferred at a high frequency from S. pyogenes Spy005 and at very low frequencies from S. pneumoniae Spn529 and S. pyogenes Spy029. PMID:25070090

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

2014-10-01

117

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

118

Crystal Structure of Streptococcus pyogenes Csn2 Reveals Calcium-Dependent Conformational Changes in Its Tertiary and Quaternary Structure  

PubMed Central

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins constitute a microbial immune system against invading genetic elements, such as plasmids and phages. Csn2 is an Nmeni subtype-specific Cas protein, and was suggested to function in the adaptation process, during which parts of foreign nucleic acids are integrated into the host microbial genome to enable immunity against future invasion. Here, we report a 2.2 Å crystal structure of Streptococcus pyogenes Csn2. The structure revealed previously unseen calcium-dependent conformational changes in its tertiary and quaternary structure. This supports the proposed double-stranded DNA-binding function of S. pyogenes Csn2. PMID:22479393

Bae, Euiyoung

2012-01-01

119

Adaptive Evolution of the Streptococcus pyogenes Regulatory Aldolase LacD.1  

PubMed Central

In the human-pathogenic bacterium Streptococcus pyogenes, the tagatose bisphosphate aldolase LacD.1 likely originated through a gene duplication event and was adapted to a role as a metabolic sensor for regulation of virulence gene transcription. Although LacD.1 retains enzymatic activity, its ancestral metabolic function resides in the LacD.2 aldolase, which is required for the catabolism of galactose. In this study, we compared these paralogous proteins to identify characteristics correlated with divergence and novel function. Surprisingly, despite the fact that these proteins have identical active sites and 82% similarity in amino acid sequence, LacD.1 was less efficient at cleaving both fructose and tagatose bisphosphates. Analysis of kinetic properties revealed that LacD.1's adaptation was associated with a decrease in kcat and an increase in Km. Construction and analysis of enzyme chimeras indicated that non-active-site residues previously associated with the variable activities of human aldolase isoenzymes modulated LacD.1's affinity for substrate. Mutant LacD.1 proteins engineered to have LacD.2-like levels of enzymatic efficiency lost the ability to function as regulators, suggesting that an alteration in efficiency was required for adaptation. In competition under growth conditions that mimic a deep-tissue environment, LacD.1 conferred a significant gain in fitness that was associated with its regulatory activity. Taken together, these data suggest that LacD.1's adaptation represents a form of neofunctionalization in which duplication facilitated the gain of regulatory function important for growth in tissue and pathogenesis. PMID:23316044

Cusumano, Zachary

2013-01-01

120

Streptococcus pyogenes polymyxin B-resistant mutants display enhanced ExPortal integrity.  

PubMed

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; Caparon, Michael G

2014-07-01

121

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

122

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

123

Disease Manifestations and Pathogenic Mechanisms of Group A Streptococcus  

PubMed Central

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

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

2014-01-01

124

Disease manifestations and pathogenic mechanisms of group a Streptococcus.  

PubMed

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

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

2014-04-01

125

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

126

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

PubMed

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

2014-05-01

127

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

128

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

PubMed Central

The sequence of the fibronectin-binding domain of the fibronectin-binding protein of Streptococcus pyogenes (Sfb protein) was determined, and its role in streptococcal adherence was investigated by use of an Sfb fusion protein in adherence studies. A 1-kb DNA fragment coding for the binding domain of Sfb protein was cloned into the expression vector pEX31 to produce an Sfb fusion protein consisting of the N-terminal part of MS2 polymerase and a C-terminal fragment of the streptococcal protein. Induction of the vector promoter resulted in hyperexpression of fibronectin-binding fusion protein in the cytoplasm of the recombinant Escherichia coli cells. Sequence determination of the cloned 1-kb fragment revealed an in-frame reading frame for a 268-amino-acid peptide composed of a 37-amino-acid sequence which is completely repeated three times and incompletely repeated a fourth time. Cloning of one repeat into pEX31 resulted in expression of small fusion peptides that show fibronectin-binding activity, indicating that one repeat contains at least one binding domain. Each repeat exhibits two charged domains and shows high homology with the 38-amino-acid D3 repeat of the fibronectin-binding protein of Staphylococcus aureus. Sequence comparison with other streptococcal ligand-binding surface proteins, including M protein, failed to reveal significant homology, which suggests that Sfb protein represents a novel type of functional protein in S. pyogenes. The Sfb fusion protein isolated from the cytoplasm of recombinant cells was purified by fast protein liquid chromatography. It showed a strong competitive inhibition of fibronectin binding to S. pyogenes and of the adherence of bacteria to cultured epithelial cells. In contrast, purified streptococcal lipoteichoic acid showed only a weak inhibition of fibronectin binding and streptococcal adherence. These results demonstrate that Sfb protein is directly involved in the fibronectin-mediated adherence of S. pyogenes to epithelial cells. Images PMID:1386839

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

1992-01-01

129

In Vivo Expression of Streptococcus pyogenes Immunogenic Proteins during Tibial Foreign Body Infection  

PubMed Central

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.

2014-01-01

130

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

131

M-protein and other intrinsic virulence factors of Streptococcus pyogenes are encoded on an ancient pathogenicity island  

PubMed Central

Background The increasing number of completely sequenced bacterial genomes allows comparing their architecture and genetic makeup. Such new information highlights the crucial role of lateral genetic exchanges in bacterial evolution and speciation. Results Here we analyzed the twelve sequenced genomes of Streptococcus pyogenes by a naïve approach that examines the preferential nucleotide usage along the chromosome, namely the usage of G versus C (GC-skew) and T versus A (TA-skew). The cumulative GC-skew plot presented an inverted V-shape composed of two symmetrical linear segments, where the minimum and maximum corresponded to the origin and terminus of DNA replication. In contrast, the cumulative TA-skew presented a V-shape, which segments were interrupted by several steep slopes regions (SSRs), indicative of a different nucleotide composition bias. Each S. pyogenes genome contained up to nine individual SSRs, encompassing all described strain-specific prophages. In addition, each genome contained a similar unique non-phage SSR, the core of which consisted of 31 highly homologous genes. This core includes the M-protein, other mga-related factors and other virulence genes, totaling ten intrinsic virulence genes. In addition to a high content in virulence-related genes and to a peculiar nucleotide bias, this SSR, which is 47 kb-long in a M1GAS strain, harbors direct repeats and a tRNA gene, suggesting a mobile element. Moreover, its complete absence in a M-protein negative group A Streptococcus natural isolate demonstrates that it could be spontaneously lost, but in vitro deletion experiments indicates that its excision occurred at very low rate. The stability of this SSR, combined to its presence in all sequenced S. pyogenes sequenced genome, suggests that it results from an ancient acquisition. Conclusion Thus, this non-phagic SSR is compatible with a pathogenicity island, acquired before S. pyogenes speciation. Its potential excision might bear relevance for vaccine development, because vaccines targeting M-protein might select for M-protein-negative variants that still carry other virulence determinants. PMID:19397826

Panchaud, Alexandre; Guy, Lionel; Collyn, François; Haenni, Marisa; Nakata, Masanobu; Podbielski, Andreas; Moreillon, Philippe; Roten, Claude-Alain H

2009-01-01

132

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

133

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

PubMed Central

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

2015-01-01

134

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

135

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

PubMed

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

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

2012-07-01

136

[Fc-receptor proteins of Streptococcus pyogenes and pathogenesis of post-infection complications].  

PubMed

Phenomenon and mechanism of non-immune binding of immunoglobulins G and A by various emm-genotypes of group A streptococcus and in particular M-family proteins--main factors of pathogenicity of this causative agent of widespread human diseases are examined. The role of these receptor proteins in pathogenesis of post-streptococcal damage of kidneys (glomerules) and heart (myocarditis) are proved. Results of long-term studies that confirm hypothesis of initiating function of Fc-receptor M proteins in genesis of immune inflammation in organ tissues that precede development of glomerulonephritis and myocarditis are provided. According to the basic position, Fc-binding of an immunoglobulin by M proteins initiates production of anti-IgG, immune complexes of various composition and complement activation, deposition of those in tissues results in lymphocyte infiltration and production of pro-inflammatory cytokines. Literature data on the role of Fc-binding proteins in genesis of IgA-nephropathies and rheumatoid factor is also examined. An important role of other factors of the microbe is discussed such as cross-reacting antigens, erythrogenic toxin B, system of streptokinase-plasmin receptor or endostreptosin in post-streptococcal processes in kidneys. Their participation in the process must be mediated by an inflammation reaction in the tissue that is initiated by interaction of immunoglobulins with Fc-binding proteins of the microbe. A novel approach to understanding the nature of this pathology allowed to establish the ability of Fc-fragments of immunoglobulin G to suppress the development of the process. PMID:25286515

Totolian, A A; Burova, L A

2014-01-01

137

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

138

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

139

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

PubMed

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

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

2015-01-01

140

Decline in macrolide-resistant Streptococcus pyogenes isolates from French children.  

PubMed

We studied the macrolide resistance and serotypes of 585 group A streptococcus (GAS) isolates collected from French children with pharyngitis. Nineteen isolates (3.2%) were erythromycin-resistant and harbored the following resistance genes: 31.6% mef(A), 15.8% erm(A), and 52.6% erm(B). The 19 isolates included 7 different emm types (4, 1, 11, 2, 28, 12, and 77) and 7 corresponding multilocus sequence types. The current fall in macrolide consumption has led to a very low rate of GAS macrolide resistance. PMID:23103047

d'Humières, Camille; Cohen, Robert; Levy, Corinne; Bidet, Philippe; Thollot, Franck; Wollner, Alain; Bingen, Edouard

2012-12-01

141

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

PubMed Central

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

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

2001-01-01

142

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

PubMed

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

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

2014-07-01

143

Exclusion of bioactive contaminations in Streptococcus pyogenes erythrogenic toxin A preparations by recombinant expression in Escherichia coli.  

PubMed Central

The streptococcal erythrogenic exotoxin A (SPEA) belongs to the family of bacterial superantigens and has been implicated in the pathogenesis of a toxic shock-like syndrome and scarlet fever. Concerning its biological activity, mainly T-cell-stimulatory properties, conflicting data exist. In this study, we show that most of the SPEA preparations used so far contain biologically active contaminations. Natural SPEA from the culture supernatant of Streptococcus pyogenes NY-5 and recombinant SPEA purified from the culture filtrate of S. sanguis are strongly contaminated with DNases. We show that natural SPEA induces more tumor necrosis factor alpha (TNF-alpha) than recombinant SPEA, but we also show that DNases are able to induce TNF-alpha. In commercial SPEA preparations, we identified a highly active protease, which was shown not to be SPEB. To exclude these contaminations, we overexpressed SPEA cloned in the effective high-level expression vector pIN-III-ompA2 in Escherichia coli. The expressed SPEA shows the same amino acid composition as natural SPEA, whereas functional studies reported so far were carried out with toxins containing an incorrect amino terminus. We describe the rapid purification of lipopolysaccharide-, DNase-, and protease-free SPEA in two steps from the host's periplasm and its structural characterization by circular dichroism. Our results represent for the first time the production in E. coli of recombinant SPEA with the authentic N-terminal sequence and a proven superantigenic activity. Collectively, our results indicate that immunological studies of superantigens require highly purified substances free of biologically active contaminations. PMID:9353057

Fagin, U; Hahn, U; Grötzinger, J; Fleischer, B; Gerlach, D; Buck, F; Wollmer, A; Kirchner, H; Rink, L

1997-01-01

144

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

PubMed Central

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

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

2010-01-01

145

Characterization of Streptococcus pyogenes beta-NAD+ glycohydrolase: re-evaluation of enzymatic properties associated with pathogenesis.  

PubMed

The gram-positive pathogen Streptococcus pyogenes injects a beta-NAD(+) glycohydrolase (SPN) into the cytosol of an infected host cell using the cytolysin-mediated translocation pathway. In this compartment, SPN accelerates the death of the host cell by an unknown mechanism that may involve its beta-NAD(+)-dependent enzyme activities. SPN has been reported to possess the unique characteristic of not only catalyzing hydrolysis of beta-NAD(+), but also carrying out ADP-ribosyl cyclase and ADP-ribosyltransferase activities, making SPN the only beta-NAD(+) glycohydrolase that can catalyze all of these reactions. With the long term goal of understanding how these activities may contribute to pathogenesis, we have further characterized the enzymatic activity of SPN using highly purified recombinant protein. Kinetic studies of the multiple activities of SPN revealed that SPN possessed only beta-NAD(+) hydrolytic activity and lacked detectable ADP-ribosyl cyclase and ADP-ribosyltransferase activities. Similarly, SPN was unable to catalyze cyclic ADPR hydrolysis, and could not catalyze methanolysis or transglycosidation. Kinetic analysis of product inhibition by recombinant SPN demonstrated an ordered uni-bi mechanism, with ADP-ribose being released as a second product. SPN was unaffected by product inhibition using nicotinamide, suggesting that this moiety contributes little to the binding energy of the substrate. Upon transformation, SPN was toxic to Saccharomyces cerevisiae, whereas a glycohydrolase-inactive SPN allowed for viability. Taken together, these data suggest that SPN functions exclusively as a strict beta-NAD(+) glycohydrolase during pathogenesis. PMID:20018886

Ghosh, Joydeep; Anderson, Patricia J; Chandrasekaran, Sukantha; Caparon, Michael G

2010-02-19

146

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

PubMed

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

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

2014-12-01

147

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

PubMed Central

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 heme-associated protein, designated Shp, was produced in vitro by GAS, located on the bacterial cell surface, and accessible to specific antibody raised against the purified recombinant protein. Mice inoculated subcutaneously with GAS and humans with invasive infections and pharyngitis caused by GAS seroconverted to Shp, indicating that Shp was produced in vivo. The blood of mice actively immunized with Shp had significantly higher bactericidal activity than the blood of unimmunized mice. The shp gene was cotranscribed with eight contiguous genes, including homologues of an ABC transporter involved in iron uptake in gram-negative bacteria. Our results indicate that Shp is a novel cell surface heme-associated protein. PMID:12117961

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

2002-01-01

148

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

PubMed Central

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

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

2013-01-01

149

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

150

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

PubMed Central

Our multicenter nationwide surveillance data indicated that erythromycin (ERY) resistance among group A Streptococcus (GAS) isolates in Taiwan declined from 53.1% in 1998 and 2000 to 14.6% in 2002 and 2004 and 10.7% in 2006 to 2010 (P < 0.01). The present study aimed to assess the epidemiology of GAS in Taiwan and identify factors associated with ERY resistance. All 127 ERY-resistant (ERYr) isolates and 128 randomly selected ERY-susceptible (ERYs) isolates recovered from 1998 to 2010 were emm typed. ERYr isolates were also characterized by ERY resistance phenotype and mechanisms and pulsed-field gel electrophoresis (PFGE). Multilocus sequence typing was performed on selected ERYr isolates. The predominant emm types in ERYr isolates were emm22 (n = 33, 26.0%), emm12 (n = 24, 18.9%), emm4 (n = 21, 16.5%), and emm106 (n = 15, 11.8%). In ERYs isolates, emm12 (n = 27, 21.9%), emm1 (n = 18, 14.1%), emm106 (n = 16, 12.5%), and emm11 (n = 9, 7.1%) predominated. The most common ERY resistance phenotype was the M phenotype (resistant to macrolides) (70.9%), with all but one isolate carrying mef(A), followed by the constitutive macrolide-lincosamide-streptogramin B resistance (cMLSB) phenotype (26.8%), with isolates carrying erm(B) or erm(TR). ERYr isolates of the emm12-sequence type 36 (ST36) lineage with the cMLSB phenotype were mostly present before 2004, while those of the emm22-ST46 lineage with the M phenotype predominated in later years. Recovery from respiratory (throat swab) specimens was an independent factor associated with ERY resistance. emm1 and emm11 GAS isolates were significantly associated with ERYs, while emm22 was detected only in ERYr GAS. In addition, emm106 isolates were prevalent among the abscess/pus isolates, whereas emm12 isolates were strongly associated with a respiratory (throat) origin. In addition to identifying factors associated with ERY resistance in GAS, our study provides helpful information on the changing GAS epidemiology in Taiwan. PMID:24478481

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

2014-01-01

151

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

PubMed Central

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

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

2013-01-01

152

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

PubMed

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

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

2014-12-01

153

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

PubMed Central

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

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

2012-01-01

154

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

PubMed Central

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

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

2013-01-01

155

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

PubMed

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

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

2013-12-01

156

Differential endometrial cell sensitivity to a cholesterol-dependent cytolysin links Trueperella pyogenes to uterine disease in cattle.  

PubMed

Purulent disease of the uterus develops in 40% of dairy cows after parturition, when the epithelium of the endometrium is disrupted to expose the underlying stroma to bacteria. The severity of endometrial pathology is associated with isolation of Trueperella pyogenes. In the present study, T. pyogenes alone caused uterine disease when infused into the uterus of cattle where the endometrial epithelium was disrupted. The bacterium secretes a cholesterol-dependent cytolysin, pyolysin (PLO), and the plo gene was identical and the plo gene promoter was highly similar amongst 12 clinical isolates of T. pyogenes. Bacteria-free filtrates of the T. pyogenes cultures caused hemolysis and endometrial cytolysis, and PLO was the main cytolytic agent, because addition of anti-PLO antibody prevented cytolysis. Similarly, a plo-deletion T. pyogenes mutant did not cause hemolysis or endometrial cytolysis. Endometrial stromal cells were notably more sensitive to PLO-mediated cytolysis than epithelial or immune cells. Stromal cells also contained more cholesterol than epithelial cells, and reducing stromal cell cholesterol content using cyclodextrins protected against PLO. Although T. pyogenes or plo-deletion T. pyogenes stimulated accumulation of inflammatory mediators, such as IL-1beta, IL-6, and IL-8, from endometrium, PLO did not stimulate inflammatory responses by endometrial or hematopoietic cells, or in vitro organ cultures of endometrium. The marked sensitivity of stromal cells to PLO-mediated cytolysis provides an explanation for how T. pyogenes acts as an opportunistic pathogen to cause pathology of the endometrium once the protective epithelium is lost after parturition. PMID:24478394

Amos, Matthew R; Healey, Gareth D; Goldstone, Robert J; Mahan, Suman M; Düvel, Anna; Schuberth, Hans-Joachim; Sandra, Olivier; Zieger, Peter; Dieuzy-Labaye, Isabelle; Smith, David G E; Sheldon, Iain Martin

2014-03-01

157

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

158

Streptococcus pyogenes c-di-AMP phosphodiesterase, GdpP, influences SpeB processing and virulence.  

PubMed

Small cyclic nucleotide derivatives are employed as second messengers by both prokaryotes and eukaryotes to regulate diverse cellular processes responding to various signals. In bacteria, c-di-AMP has been discovered most recently, and some Gram-positive pathogens including S. pyogenes use this cyclic nucleotide derivative as a second messenger instead of c-di-GMP, a well-studied important bacterial second messenger. GdpP, c-di-AMP phosphodiesterase, is responsible for degrading c-di-AMP inside cells, and the cellular role of GdpP in S. pyogenes has not been examined yet. To test the cellular role of GdpP, we created a strain with a nonpolar inframe deletion of the gdpP gene, and examined the properties of the strain including virulence. From this study, we demonstrated that GdpP influences the biogenesis of SpeB, the major secreted cysteine protease, at a post-translational level, susceptibility to the beta lactam antibiotic ampicillin, and is necessary for full virulence in a murine subcutaneous infection model. PMID:23869242

Cho, Kyu Hong; Kang, Song Ok

2013-01-01

159

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

PubMed

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

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

2015-01-01

160

[Pyogenic liver abscess caused by Klebsiella pneumoniae].  

PubMed

Pyogenic liver abscess caused by Klebsiella pneumoniae is usually found in Southeast Asia, while in Europe Escherichia coli, Streptococcus or Staphylococcus are most common. In case of a failed ultrasound controlled abscess, aspiration surgical treatment is indicated. This paper reports the clinical case of pyogenic liver abscess caused by Klebsiella pneumoniae, which was treated by operative drainage. A 60-year-old patient was transferred to our institution from the University Hospital for Infectious Diseases with septic temperature, abdominal pain and finding of Klebsiella pneumoniae liver abscess (resistant to antibiotic therapy). Additional laboratory tests and abdominal MSCT scan confirmed the initial diagnosis. The localization of abscesses technically prevented ultrasound-controlled abscess aspiration and drainage; after appropriate preparation, operative liver abscess incision and drainage were performed. Microbiological examination of the abscess sample revealed Klebsiella pneumoniae as the cause of liver abscess. PMID:23814976

Zorici?, Ivan; Vukusi?, Darko; Sever, Marko; Lojo, Nermin; Bari?, Marko

2012-10-01

161

SpyA, a C3-like ADP-ribosyltransferase, contributes to virulence in a mouse subcutaneous model of Streptococcus pyogenes infection.  

PubMed

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

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

2011-06-01

162

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

163

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

PubMed Central

Background The oral probiotic Streptococcus salivarius K12 has been shown clearly to antagonize the growth of Streptococcus pyogenes, the most important bacterial cause of pharyngeal infections in humans, by releasing two bacteriocins named salivaricin A2 and salivaricin B. Unpublished observations indicate that it can also antagonize the growth of other bacteria involved in acute otitis media. Because of its ability to colonize the oral cavity and its safety profile, we have tested its efficacy in reducing the incidence of streptococcal pharyngitis and/or tonsillitis and episodes of acute otitis media. Methods We enrolled 82 children, including 65 with and 17 without a recent diagnosis of recurrent oral streptococcal pathology. Of those with recurrent pathology, 45 were treated daily for 90 days with an oral slow-release tablet containing five billion colony-forming units of S. salivarius K12 (Bactoblis®), and the remaining 20 served as an untreated control group. The 17 children without a recent diagnosis of recurrent oral pathology were used as an additional control group. After 90 days of treatment, a 6-month follow-up period without treatment was included to evaluate a possible persistent protective role for the previously administered product. Results The 41 children who completed the 90-day course of Bactoblis showed a reduction in their episodes of streptococcal pharyngeal infection (about 90%) and/or acute otitis media (about 40%), calculated by comparing infection rates in the previous year. The 90-day treatment also reduced the reported incidence of pharyngeal and ear infections by about 65% in the 6-month follow-up period during which the product was not administered. Subjects tolerated the product well, with no side effects or dropouts reported. Conclusion Prophylactic administration of S. salivarius K12 to children with a history of recurrent oral streptococcal pathology reduced episodes of streptococcal pharyngeal infections and/or tonsillitis as well as episodes of acute otitis media. PMID:23233809

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

2012-01-01

164

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

165

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

166

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

167

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

168

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

PubMed Central

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

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

2012-01-01

169

The molecular basis of Streptococcus equi infection and disease.  

PubMed

Streptococcus equi is the aetiological agent of strangles, one of the most prevalent diseases of the horse. The animal suffering and economic burden associated with this disease necessitate effective treatment. Current antibiotic therapy is often ineffective and thus recent attention has focused on vaccine development. A systematic understanding of S. equi virulence, leading to the identification of targets to which protective immunity can be directed, is a prerequisite of the development of such a vaccine. Here, the virulence factors of S. equi are reviewed. PMID:11932201

Harrington, Dean J; Sutcliffe, Iain C; Chanter, Neil

2002-04-01

170

Epethelial Presence of Trueperella pyogenes Predicts Site-Level Presence of Cranial Abscess Disease in White-Tailed Deer (Odocoileus virginianus)  

PubMed Central

Cranial/intracranial abscess disease is an emerging source of significant mortality for male white-tailed deer (Odocoileus virginianus). Most cases of cranial/intracranial abscess disease are associated with infection by the opportunistic pathogen Trueperella pyogenes although the relationship between the prevalence of the bacteria and occurrence of disease is speculative. We examined 5,612 hunter-harvested deer from 29 sites across all physiographic provinces in Georgia for evidence of cranial abscess disease and sampled the forehead, lingual, and nasal surfaces from 692 deer. We used polymerase chain reaction (PCR) to determine presence of T. pyogenes from these samples. We found T. pyogenes prevalence at a site was a predictor for the occurrence of cranial abscess disease. Prevalence of T. pyogenes did not differ between samples from the nose or tongue although prevalence along the forehead was greater for males than females (p = 0.04), particularly at sites with high occurrence of this disease. Socio-sexual behaviors, bacterial prevalence, or physiological characteristics may predispose male deer to intracranial/cranial abscess disease. Determination of factors that affect T. pyogenes prevalence among sites may help explain the occurrence of this disease among populations. PMID:25803047

Belser, Emily H.; Cohen, Bradley S.; Keeler, Shamus P.; Killmaster, Charles H.; Bowers, John W.; Miller, Karl V.

2015-01-01

171

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

172

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

173

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

174

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

PubMed

The host-restricted bacterium Streptococcus equi is the causative agent of equine strangles, the most frequently diagnosed infectious disease of horses worldwide. The disease is characterized by abscessation of the lymph nodes of the head and neck, leading to significant welfare and economic cost. S. equi is believed to have evolved from an ancestral strain of Streptococcus zooepidemicus, an opportunistic pathogen of horses and other animals. Comparison of the genome of S. equi strain 4047 with those of S. zooepidemicus identified examples of gene loss due to mutation and deletion, and gene gain through the acquisition of mobile genetic elements that have probably shaped the pathogenic specialization of S. equi. In particular, deletion of the CRISPR (clustered regularly interspaced short palindromic repeats) locus in the ancestor of S. equi may have predisposed the bacterium to acquire and incorporate new genetic material into its genome. These include four prophages and a novel integrative conjugative element. The virulence cargo carried by these mobile genetic elements is believed to have shaped the ability of S. equi to cause strangles. Further sequencing of S. zooepidemicus has highlighted the diversity of this opportunistic pathogen. Again, CRISPRs are postulated to influence evolution, balancing the need for gene gain over genome stability. Analysis of spacer sequences suggest that these pathogens may be susceptible to a limited range of phages and provide further evidence of cross-species exchange of genetic material among Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus dysgalactiae. PMID:24256234

Waller, Andrew S; Robinson, Carl

2013-12-01

175

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

176

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. PMID:25629011

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

2015-01-01

177

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 Central

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 125I-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.

2013-01-01

178

Arcanobacterium pyogenes mastitis in an 18-month-old heifer  

Microsoft Academic Search

ExtractIn New Zealand, the agent Arcanobacterium (formerly Actinomyces) pyogenes is commonly associated with suppurative diseases in cattle, including abscesses, chronic endometritis and embolic pneumonia, but is an uncommon pathogen in bovine mastitis. Overseas, A. pyogenes mastitis is widespread and usually sporadic. The source of infection is considered to be endogenous, as A. pyogenes can be recovered from the mucous membranes,

AK Quinn; JJ Vermunt; DP Twiss

2002-01-01

179

Streptococcus-Zebrafish Model of Bacterial Pathogenesis  

PubMed Central

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

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

2002-01-01

180

Complete genome sequence of a virulent Streptococcus agalactiae strain 138P isolated from diseased Nile tilapia  

Technology Transfer Automated Retrieval System (TEKTRAN)

Streptococcus agalactiae strain 138P was isolated from the kidney of diseased Nile tilapia in Idaho during a 2007 streptococcal disease outbreak. The full genome of S. agalactiae 138P is 1,838,716 bp. The availability of this genome will allow comparative genomics to identify genes for antigen disco...

181

Invasive group B streptococcus (GBS) disease in Norway 1996–2006  

Microsoft Academic Search

The aim of this study was to survey the occurrence of invasive group B streptococcus (GBS) disease in Norway and detect possible\\u000a trends in characteristics of invasive GBS strains from1996 to 2006. Data from national monitoring systems for infectious diseases\\u000a in Norway were analysed. Of 638,452 live births in the period, 434 cases of invasive GBS disease in infants were

H. Bergseng; M. Rygg; L. Bevanger; K. Bergh

2008-01-01

182

Replacement of Histidine 340 with Alanine Inactivates the Group A Streptococcus Extracellular Cysteine Protease Virulence Factor  

Microsoft Academic Search

Streptococcus pyogenes expresses a highly conserved extracellular cysteine protease that is a virulence factor for invasive disease, including soft tissue infection. Site-directed mutagenesis was used to generate a His340Ala recombinant mutant protein that was made as a stable 40-kDa zymogen by Escherichia coli. Purified His340Ala protein was proteolytically inactive when bovine casein and human fibronectin were used as substrates. Wild-type

SIDDESWAR GUBBA; VINCENT CIPRIANO; JAMES M. MUSSER

2000-01-01

183

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

184

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

185

Pyogenic Liver Abscess with a Focus on Klebsiella pneumoniae as a Primary Pathogen: An Emerging Disease with Unique Clinical Characteristics  

Microsoft Academic Search

OBJECTIVES:Pyogenic liver abscess is a common intraabdominal infection. Historically, Escherichia coli (E. coli) has been the predominant causative agent. Klebsiella liver abscess (KLA) was first reported in Taiwan and has surpassed E. coli as the number one isolate from patients with hepatic abscesses in that country and reports from other countries, including the United States, have increased. We examined the

Edith R. Lederman; Nancy F. Crum

2005-01-01

186

Association between virulence factors of Escherichia coli, Fusobacterium necrophorum, and Arcanobacterium pyogenes and uterine diseases of dairy cows.  

PubMed

The objective of this study was to evaluate the relationship between bacterial species-specific virulence factors (VFs) present in the uterus at 3 different stages of lactation (1-3, 8-10, and 34-36 days in milk (DIM)) and the incidence of metritis and clinical endometritis in dairy cows. The following VF genes were investigated: plo (pyolysin), cbpA (collagen-binding protein), and fimA (fimbriae expression) which are Arcanobacterium pyogenes specific; fimH (a type 1 pilus component), Escherichia coli specific; and lktA (leukotoxin), Fusobacterium necrophorum specific. Uterine swabs were collected from 111 postpartum dairy cows. PCR was used to detect the presence of plo, cbpA, fimA, fimH, and lktA genes. A. pyogenes cbpA was detected in only 5 samples and therefore was not subjected to further analysis. E. coli (fimH) was significantly associated with metritis and endometritis when detected at 1-3 DIM; F. necrophorum (lktA) was significantly associated with metritis when detected at 1-3 and 8-12 DIM and with endometritis when detected at 34-36 DIM; and A. pyogenes (fimA and plo) was associated with metritis (fimA) when detected at 1-3 DIM and endometritis (fimA and plo) when detected at 8-10 and 34-36 DIM. PMID:22186615

Bicalho, M L S; Machado, V S; Oikonomou, G; Gilbert, R O; Bicalho, R C

2012-05-25

187

Advances in potential M-protein peptide-based vaccines for preventing rheumatic fever and rheumatic heart disease  

Microsoft Academic Search

Rheumatic fever (RF) and rheumatic heart disease (RHD) are post-infectious complications of an infection (or repeated infection)\\u000a with the Gram-positive bacterium Streptococcus pyogenes (also known as group A streptococcus, GAS). RF and RHD are global problems and affect many indigenous populations of developed\\u000a countries and many developing countries. However, RF and RHD are only part of a larger spectrum of

Michael R. Batzloff; Manisha Pandey; Colleen Olive; Michael F. Good

2006-01-01

188

Rheumatic Fever and Rheumatic Heart Disease: Cellular Mechanisms Leading Autoimmune Reactivity and Disease  

Microsoft Academic Search

Introduction  Rheumatic fever (RF) is an autoimmune disease caused by the gram-positive bacteria Streptococcus pyogenes that follows a nontreated throat infection in susceptible children. The disease manifests as polyarthritis, carditis, chorea,\\u000a erythema marginatum, and\\/or subcutaneous nodules. Carditis, the most serious complication, occurs in 30% to 45% of RF patients\\u000a and leads to chronic rheumatic heart disease (RHD), which is characterized by

Luiza Guilherme; Jorge Kalil

2010-01-01

189

Genomic signatures of human and animal disease in the zoonotic pathogen Streptococcus suis  

PubMed Central

Streptococcus suis causes disease in pigs worldwide and is increasingly implicated in zoonotic disease in East and South-East Asia. To understand the genetic basis of disease in S. suis, we study the genomes of 375 isolates with detailed clinical phenotypes from pigs and humans from the United Kingdom and Vietnam. Here, we show that isolates associated with disease contain substantially fewer genes than non-clinical isolates, but are more likely to encode virulence factors. Human disease isolates are limited to a single-virulent population, originating in the 1920, s when pig production was intensified, but no consistent genomic differences between pig and human isolates are observed. There is little geographical clustering of different S. suis subpopulations, and the bacterium undergoes high rates of recombination, implying that an increase in virulence anywhere in the world could have a global impact over a short timescale. PMID:25824154

Weinert, Lucy A.; Chaudhuri, Roy R.; Wang, Jinhong; Peters, Sarah E.; Corander, Jukka; Jombart, Thibaut; Baig, Abiyad; Howell, Kate J.; Vehkala, Minna; Välimäki, Niko; Harris, David; Chieu, Tran Thi Bich; Van Vinh Chau, Nguyen; Campbell, James; Schultsz, Constance; Parkhill, Julian; Bentley, Stephen D.; Langford, Paul R.; Rycroft, Andrew N.; Wren, Brendan W.; Farrar, Jeremy; Baker, Stephen; Hoa, Ngo Thi; Holden, Matthew T.G.; Tucker, Alexander W.; Maskell, Duncan J.; Bossé, Janine T.; Li, Yanwen; Maglennon, Gareth A.; Matthews, Dominic; Cuccui, Jon; Terra, Vanessa

2015-01-01

190

Genomic signatures of human and animal disease in the zoonotic pathogen Streptococcus suis.  

PubMed

Streptococcus suis causes disease in pigs worldwide and is increasingly implicated in zoonotic disease in East and South-East Asia. To understand the genetic basis of disease in S. suis, we study the genomes of 375 isolates with detailed clinical phenotypes from pigs and humans from the United Kingdom and Vietnam. Here, we show that isolates associated with disease contain substantially fewer genes than non-clinical isolates, but are more likely to encode virulence factors. Human disease isolates are limited to a single-virulent population, originating in the 1920, s when pig production was intensified, but no consistent genomic differences between pig and human isolates are observed. There is little geographical clustering of different S. suis subpopulations, and the bacterium undergoes high rates of recombination, implying that an increase in virulence anywhere in the world could have a global impact over a short timescale. PMID:25824154

Weinert, Lucy A; Chaudhuri, Roy R; Wang, Jinhong; Peters, Sarah E; Corander, Jukka; Jombart, Thibaut; Baig, Abiyad; Howell, Kate J; Vehkala, Minna; Välimäki, Niko; Harris, David; Chieu, Tran Thi Bich; Van Vinh Chau, Nguyen; Campbell, James; Schultsz, Constance; Parkhill, Julian; Bentley, Stephen D; Langford, Paul R; Rycroft, Andrew N; Wren, Brendan W; Farrar, Jeremy; Baker, Stephen; Hoa, Ngo Thi; Holden, Matthew T G; Tucker, Alexander W; Maskell, Duncan J

2015-01-01

191

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

192

Arcanobacterium pyogenes : molecular pathogenesis of an animal opportunist  

Microsoft Academic Search

Arcanobacterium pyogenes is a commensal and an opportunistic pathogen of economically important livestock, causing diseases as diverse as mastitis, liver abscessation and pneumonia. This organism possesses a number of virulence factors that contribute to its pathogenic potential. A. pyogenes expresses a cholesterol-dependent cytolysin, pyolysin, which is a haemolysin and is cytolytic for immune cells, including macrophages. Expression of pyolysin is

B. Helen Jost; Stephen J. Billington

2005-01-01

193

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

194

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

195

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

196

Identification of a Streptolysin S-Associated Gene Cluster and Its Role in the Pathogenesis of Streptococcus iniae Disease  

Microsoft Academic Search

Streptococcus iniae causes meningoencephalitis and death in cultured fish species and soft-tissue infection in humans. We recently reported that S. iniae is responsible for local tissue necrosis and bacteremia in a murine subcutaneous infection model. The ability to cause bacteremia in this model is associated with a genetic profile unique to strains responsible for disease in fish and humans (J.

Jeffrey D. Fuller; Alvin C. Camus; Carla L. Duncan; Victor Nizet; Darrin J. Bast; Ronald L. Thune; Donald E. Low; J. C. S. de Azavedo

2002-01-01

197

Streptococcus suis infection: an emerging/reemerging challenge of bacterial infectious diseases?  

PubMed

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

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

2014-05-15

198

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

199

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

200

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

201

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

202

Comparative genomics and the role of lateral gene transfer in the evolution of bovine adapted Streptococcus agalactiae  

PubMed Central

In addition to causing severe invasive infections in humans, Streptococcus agalactiae, or group B Streptococcus (GBS), is also a major cause of bovine mastitis. Here we provide the first genome sequence for S. agalactiae isolated from a cow diagnosed with clinical mastitis (strain FSL S3-026). Comparison to eight S. agalactiae genomes obtained from human disease isolates revealed 183 genes specific to the bovine strain. Subsequent polymerase chain reaction (PCR) screening for the presence/absence of a subset of these loci in additional bovine and human strains revealed strong differentiation between the two groups (Fisher exact test: p < 0.0001). The majority of the bovine strain-specific genes (~85%) clustered tightly into eight genomic islands, suggesting these genes were acquired through lateral gene transfer (LGT). This bovine GBS also contained an unusually high proportion of insertion sequences (4.3% of the total genome), suggesting frequent genomic rearrangement. Comparison to other mastitis-causing species of bacteria provided strong evidence for two cases of interspecies LGT within the shared bovine environment: bovine S. agalactiae with Streptococcus uberis (nisin U operon) and Streptococcus dysgalactiae subsp. dysgalactiae (lactose operon). We also found evidence for LGT, involving the salivaricin operon, between the bovine S. agalactiae strain and either Streptococcus pyogenes or Streptococcus salivarius. Our findings provide insight intomechanismsfacilitatingenvironmentaladaptationandacquisitionofpotential virulence factors, while highlighting both the key role LGT has played in the recent evolution of the bovine S. agalactiae strain, and the importance of LGT among pathogens within a shared environment. PMID:21536150

Richards, Vincent P.; Lang, Ping; Pavinski Bitar, Paulina D.; Lefébure, Tristan; Schukken, Ynte H.; Zadoks, Ruth N.; Stanhope, Michael J.

2011-01-01

203

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

204

Attachment of capsular polysaccharide to the cell wall of Streptococcus pneumoniae type 2 is required for invasive disease  

Microsoft Academic Search

The capacity of Streptococcus pneumoniae to produce capsular polysaccharide (CPS) is essential for virulence. The CPS biosynthesis proteins CpsB, CpsC, and CpsD function to regulate CPS production via tyrosine phosphorylation of CpsD. This mechanism of regulating CPS production is important for enabling S. pneumoniae to cause invasive disease. Here, we identify mutations affecting the attachment of CPS to the cell

Judy K. Morona; Renato Morona; James C. Paton

2006-01-01

205

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

206

Neonatal Streptococcus pneumoniae Infection May Aggravate Adulthood Allergic Airways Disease in Association with IL-17A  

PubMed Central

Epidemiologic studies have demonstrated that some bacteria colonization or infections in early-life increased the risk for subsequent asthma development. However, little is known about the mechanisms by which early-life bacterial infection increases this risk. The aim of this study was to investigate the effect of neonatal Streptococcus pneumoniae infection on the development of adulthood asthma, and to explore the possible mechanism. A non-lethal S. pneumoniae lung infection was established by intranasal inoculation of neonatal (1-week-old) female mice with D39. Mice were sensitized and challenged with ovalbumin in adulthood to induce allergic airways disease (AAD). Twenty-four hours later, the lungs and bronchoalveolar lavage fluid (BALF) were collected to assess AAD. Neonatal S. pneumoniae infection exacerbated adulthood hallmark features of AAD, with enhanced airway hyperresponsiveness and increased neutrophil recruitment into the airways, increased Th17 cells and interleukin (IL)-17A productions. Depletion of IL-17A by i.p. injection of a neutralizing monoclonal antibody reduced neutrophil recruitment into the airways, alleviated airway inflammation and decreased airway hyperresponsiveness. Furthermore, IL-17A depletion partially restored levels of inteferon-?, but had no effect on the release of IL-5 or IL-13. Our data suggest that neonatal S. pneumoniae infection may promote the development of adulthood asthma in association with increased IL-17A production. PMID:25816135

Yang, Ting; Jiang, Xiaoli; Zhang, Liqun; Wang, Lijia; Wang, Qinghong; Luo, Zhengxiu; Liu, Enmei; Fu, Zhou

2015-01-01

207

Streptococcus pneumoniae infection suppresses allergic airways disease by inducing regulatory T-cells.  

PubMed

An inverse association exists between some bacterial infections and the prevalence of asthma. We investigated whether Streptococcus pneumoniae infection protects against asthma using mouse models of ovalbumin (OVA)-induced allergic airway disease (AAD). Mice were intratracheally infected or treated with killed S. pneumoniae before, during or after OVA sensitisation and subsequent challenge. The effects of S. pneumoniae on AAD were assessed. Infection or treatment with killed S. pneumoniae suppressed hallmark features of AAD, including antigen-specific T-helper cell (Th) type 2 cytokine and antibody responses, peripheral and pulmonary eosinophil accumulation, goblet cell hyperplasia, and airway hyperresponsiveness. The effect of infection on the development of specific features of AAD depended on the timing of infection relative to allergic sensitisation and challenge. Infection induced significant increases in regulatory T-cell (Treg) numbers in lymph nodes, which correlated with the degree of suppression of AAD. Tregs reduced T-cell proliferation and Th2 cytokine release. The suppressive effects of infection were reversed by anti-CD25 treatment. Respiratory infection or treatment with S. pneumoniae attenuates allergic immune responses and suppresses AAD. These effects may be mediated by S. pneumoniae-induced Tregs. This identifies the potential for the development of therapeutic agents for asthma from S. pneumoniae. PMID:20525707

Preston, J A; Thorburn, A N; Starkey, M R; Beckett, E L; Horvat, J C; Wade, M A; O'Sullivan, B J; Thomas, R; Beagley, K W; Gibson, P G; Foster, P S; Hansbro, P M

2011-01-01

208

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

209

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

2015-03-01

210

Burden of Invasive Group B Streptococcus Disease and Early Neurological Sequelae in South African Infants  

PubMed Central

Introduction Group B Streptococcus (GBS) is a leading cause of neonatal sepsis and meningitis. We aimed to evaluate the burden of invasive early-onset (0–6 days of life, EOD) and late-onset (7–89 days, LOD) GBS disease and subsequent neurological sequelae in infants from a setting with a high prevalence (29.5%) of HIV among pregnant women. Methods A case-control study was undertaken at three secondary-tertiary care public hospitals in Johannesburg. Invasive cases in infants <3 months age were identified by surveillance of laboratories from November 2012 to February 2014. Neurodevelopmental screening was done in surviving cases and controls at 3 and 6 months of age. Results We identified 122 cases of invasive GBS disease over a 12 month period. Although the incidence (per 1,000 live births) of EOD was similar between HIV-exposed and HIV-unexposed infants (1.13 vs. 1.46; p = 0.487), there was a 4.67-fold (95%CI: 2.24–9.74) greater risk for LOD in HIV-exposed infants (2.27 vs. 0.49; p<0.001). Overall, serotypes Ia, Ib and III constituted 75.8% and 92.5% of EOD and LOD, respectively. Risk factors for EOD included offensive draining liquor (adjusted Odds Ratio: 27.37; 95%CI: 1.94–386.50) and maternal GBS bacteriuria (aOR: 8.41; 95%CI: 1.44–49.15), which was also a risk-factor for LOD (aOR: 3.49; 95%CI: 1.17–10.40). The overall case fatality rate among cases was 18.0%. The adjusted odds for neurological sequelae at 6 months age was 13.18-fold (95%CI: 1.44–120.95) greater in cases (13.2%) than controls (0.4%). Discussion The high burden of invasive GBS disease in South Africa, which is also associated with high case fatality rates and significant neurological sequelae among survivors, is partly due to the heightened risk for LOD in infants born to HIV-infected women. An effective trivalent GBS conjugate vaccine targeted at pregnant women could prevent invasive GBS disease in this setting. PMID:25849416

Dangor, Ziyaad; Lala, Sanjay G.; Cutland, Clare L.; Koen, Anthonet; Jose, Lisa; Nakwa, Firdose; Ramdin, Tanusha; Fredericks, Joy; Wadula, Jeannette; Madhi, Shabir A.

2015-01-01

211

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

212

Complete genome sequence and comparative genomic analysis of an emerging human pathogen, serotype V Streptococcus agalactiae  

Microsoft Academic Search

The 2,160,267 bp genome sequence of Streptococcus agalactiae, the leading cause of bacterial sepsis, pneumonia, and meningitis in neonates in the U.S. and Europe, is predicted to encode 2,175 genes. Genome comparisons among S. agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes, and the other completely sequenced genomes identified genes specific to the streptococci and to S. agalactiae. These in silico analyses, combined

Hervé Tettelin; Vega Masignani; Michael J. Cieslewicz; Jonathan A. Eisen; Scott Peterson; Michael R. Wessels; Ian T. Paulsen; Karen E. Nelson; Immaculada Margarit; Timothy D. Read; Lawrence C. Madoff; Alex M. Wolf; Maureen J. Beanan; Lauren M. Brinkac; Sean C. Daugherty; Robert T. Deboy; A. Scott Durkin; James F. Kolonay; Ramana Madupu; Matthew R. Lewis; Diana Radune; Nadezhda B. Fedorova; David Scanlan; Hoda Khouri; Stephanie Mulligan; Heather A. Carty; Robin T. Cline; Susan E. van Aken; John Gill; Maria Scarselli; Marirosa Mora; Emilia T. Iacobini; Cecilia Brettoni; Giuliano Galli; Massimo Mariani; Filippo Vegni; Domenico Maione; Daniela Rinaudo; Rino Rappuoli; John L. Telford; Dennis L. Kasper; Guido Grandi; Claire M. Fraser

2002-01-01

213

Mode of Action of a Lysostaphin-Like Bacteriolytic Agent Produced byStreptococcus zooepidemicus4881  

Microsoft Academic Search

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,

R. S. SIMMONDS; L. PEARSON; R. C. KENNEDY; R. TAGG

1996-01-01

214

The role of Streptococcus pneumoniae virulence factors in host respiratory colonization and disease  

Microsoft Academic Search

Streptococcus pneumoniae is a Gram-positive bacterial pathogen that colonizes the mucosal surfaces of the host nasopharynx and upper airway. Through a combination of virulence-factor activity and an ability to evade the early components of the host immune response, this organism can spread from the upper respiratory tract to the sterile regions of the lower respiratory tract, which leads to pneumonia.

Jeffrey N. Weiser; James C. Paton; Peter W. Andrew; Aras Kadioglu

2008-01-01

215

Original article Actinomyces pyogenes: susceptibility  

E-print Network

(Mueller-Hinton agar supplemented with 5% sheep blood). All the strains were susceptible to penicillin G confirmed by Collins and Jones (1982). This pathogen is commonly isolated from pyogenic processes in cattle

Paris-Sud XI, Université de

216

Arcanobacterium pyogenes endocarditis: a case report and literature review.  

PubMed

We report the case of a 64-year-old man with Arcanobacterium pyogenes endocarditis. The patient presented with dyspnea and asymmetrical progressive quadriparesis. A transthoracic echocardiogram revealed mobile vegetations on both leaflets of his mitral valve measuring 0.5 x 3 cm, thickening of the mitral valve with severe mitral regurgitation due to dehiscence of the papillary muscle to the posterior mitral leaflet. He also had aortic sclerosis with a vegetation measuring 0.5 x 1 cm causing aortic valve dehiscence and free flow aortic regurgitation. An initial hemoculture grew out pleomorphic, gram-positive, non-motile, anaerobic to microaerophilic bacilli. A diagnosis of infective endocarditis was made using modified Duke criteria. He was treated with intravenous ampicillin and gentamicin. Four days after admission, he developed acute respiratory failure and succumbed to the disease. A pre-mortem hemoculture and post-mortem heart valve culture grew Arcanobacterium pyogenes. Septic thromboemboli involving the brain, kidneys, lungs and spleen were documented. The patient also had ischemic vasculopathy with focal spinal arteriolitis and bilateral demyelination of the cervical corticospinal tracts. There are three published reports of human A. pyogenes endocarditis in the literature. Neurological involvement with ischemic spinal vasculopathy and demyelination has not been reported. We report the first autopsy proven case of A. pyogenes infective endocarditis with ischemic spinal vasculopathy. We review the clinicopathologic features of systemic A. pyogenes infection. PMID:24964663

Chesdachai, Supavit; Larbcharoensub, Noppadol; Chansoon, Tharintorn; Chalermsanyakorn, Panas; Santanirand, Pitak; Chotiprasitsakul, Darunee; Ratanakorn, Disya; Boonbaichaiyapruck, Sarana

2014-01-01

217

Molecular characterization of penicillin-resistant Streptococcus pneumoniae isolates causing respiratory disease in the United States.  

PubMed

Three hundred twenty-eight (328) penicillin-resistant Streptococcus pneumoniae isolates collected in 39 states of the United States between October, 1996, and March, 1997, from (mostly adult) patients with respiratory disease were characterized by microbiological, serological, and molecular fingerprinting techniques, including determination of chromosomal macrorestriction pattern with pulsed-field gel electrophoresis (PFGE) and hybridization with DNA probes specific for various antibiotic resistance genes. The overwhelming majority of the isolates were in five serogroups (23, 6, 19, 9, 14). All isolates had penicillin MIC values of at least 2 microg/ml, but the collection also included isolates with MIC values as high as 16 microg/ml. Virtually all isolates (96.6%) were resistant to trimethoprim/sulfamethoxazole (SXT) and many isolates were also resistant to chloramphenicol (43%), tetracycline (55%), and erythromycin (65%). Resistance to levofloxacin was extremely rare. The molecular fingerprinting methods showed that a surprisingly large proportion (167 out of 328, or 50.9%) of the isolates belonged to two international epidemic clones of S. pneumoniae: clone A (127, or 38.7%) with properties indistinguishable from that of the 23F multiresistant "Spanish/USA" clone widely spread in Europe, Asia, Latin America, and South Africa, and clone B (40, or 12.2%) belonging to the "French" serogroup 9/14 clone widely spread in Europe and South America. Virtually all members of clone A were also resistant to chloramphenicol (cat+), tetracycline (tetM+), and SXT, and about 75% were also resistant to erythromycin (mefE+ or ermB+). Close to 30% (39 out of 127) of the clone A isolates expressed anomalous serotypes (primarily serotypes 19 and 14, and nontypable) and most likely represented spontaneous capsular transformants. Most of the 40 isolates (35/40) belonging to clone B expressed serotype 9, with five of the isolates expressing serotypes 14 or 19, or were nontypable. All members of this clone were resistant to penicillin and SXT with only occasional isolates showing resistance to macrolides, tetracycline, and chloramphenicol. The combination of microbiological tests and DNA hybridizations also allowed the identification of unusual strains, for instance, isolates that reacted with the tetM or mefE DNA probes without showing phenotypic antibiotic resistance, an isolate showing phenotypic macrolide resistance without hybridizing with either the ermB or mefE DNA probes, or isolates that hybridized with both of these DNA probes. In addition to clones A and B, another large portion of the S. pneumoniae isolates (112 of 328, or 34.1%) was represented by eight clusters, each with a unique PFGE type. These clusters, together with the clone A and clone B isolates, made up 85% of all the penicillin-resistant isolates identified in this survey in the United States. Both international clones and the unique clusters showed wide geographic dispersal: Clone A was present in 30 of the 39 states and clone B in 18. The data suggest that the major mode of spread of penicillin-resistant pneumococci in the United States is by clonal expansion and that the most significant components (clones A and B) have been imported into the United States from abroad. PMID:9988052

Corso, A; Severina, E P; Petruk, V F; Mauriz, Y R; Tomasz, A

1998-01-01

218

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

219

Identification of a novel collagen-like protein, SclC, in Streptococcus equi using signal sequence phage display.  

PubMed

Strangles is a serious disease in horses caused by Streptococcus equi subspecies equi. In this study, genes encoding putative extracellular proteins in this subspecies have been identified using signal sequence phage display. Among these, one showed similarities to the SclB protein, a member of the collagen-like proteins of Streptococcus pyogenes. The novel gene denoted sclC encodes a protein, SclC, of 302 amino acids, containing typical features found in cell wall-anchored proteins in Gram-positive bacteria. Based on similarities to the S. pyogenes collagen-like proteins the mature SclC protein can be divided into various domains: an N-terminal non-repetitive region (A), a highly repetitive collagen-like region (CL), and a C-terminal proline-rich wall-associated region (W). Using PCR, the sclC gene was detected in all studied strains of S. equi subsp. equi and S. equi subsp. zooepidemicus. Further, antibodies against recombinant SclC were detected in a collection of sera from horses with no history of strangles as well as horses previously infected with S. equi subsp. equi. Interestingly, the sera from convalescence horses were found to have significantly increased antibody titers against the SclC protein indicating that this protein is expressed during infection of S. equi subsp. equi. PMID:15564026

Karlström, Asa; Jacobsson, Karin; Flock, Margareta; Flock, Jan-Ingmar; Guss, Bengt

2004-12-01

220

Identification of a Streptolysin S-Associated Gene Cluster and Its Role in the Pathogenesis of Streptococcus iniae Disease  

PubMed Central

Streptococcus iniae causes meningoencephalitis and death in cultured fish species and soft-tissue infection in humans. We recently reported that S. iniae is responsible for local tissue necrosis and bacteremia in a murine subcutaneous infection model. The ability to cause bacteremia in this model is associated with a genetic profile unique to strains responsible for disease in fish and humans (J. D. Fuller, D. J. Bast, V. Nizet, D. E. Low, and J. C. S. de Azavedo, Infect. Immun. 69:1994-2000, 2001). S. iniae produces a cytolysin that confers a hemolytic phenotype on blood agar media. In this study, we characterized the genomic region responsible for S. iniae cytolysin production and assessed its contribution to virulence. Transposon (Tn917) mutant libraries of commensal and disease-associated S. iniae strains were generated and screened for loss of hemolytic activity. Analysis of two nonhemolytic mutants identified a chromosomal locus comprising 9 genes with 73% homology to the group A streptococcus (GAS) sag operon for streptolysin S (SLS) biosynthesis. Confirmation that the S. iniae cytolysin is a functional homologue of SLS was achieved by PCR ligation mutagenesis, complementation of an SLS-negative GAS mutant, and use of the SLS inhibitor trypan blue. SLS-negative sagB mutants were compared to their wild-type S. iniae parent strains in the murine model and in human whole-blood killing assays. These studies demonstrated that S. iniae SLS expression is required for local tissue necrosis but does not contribute to the establishment of bacteremia or to resistance to phagocytic clearance. PMID:12228303

Fuller, Jeffrey D.; Camus, Alvin C.; Duncan, Carla L.; Nizet, Victor; Bast, Darrin J.; Thune, Ronald L.; Low, Donald E.; de Azavedo, Joyce C. S.

2002-01-01

221

Actinomycetes in pyogenic liver abscess  

Microsoft Academic Search

Three patients with pyogenic liver abscesses had actinomycetes cultured from aspirated pus, although it is unusual for hepatic actinomycosis to present in this way. The spectrum of bacteria found in liver abscesses appears to be changing, with the increased isolation of anaerobes partly due to improved techniques. It is important to recognise the presence of actinomycetes so that appropriate chemotherapy

M. N. Logan; P. J. Stanley; A. Exley; C. Gagg; I. D. Farrell

1989-01-01

222

Single-walled carbon nanotubes based chemiresistive genosensor for label-free detection of human rheumatic heart disease  

NASA Astrophysics Data System (ADS)

A specific and ultrasensitive, label free single-walled carbon nanotubes (SWNTs) based chemiresistive genosensor was fabricated for the early detection of Streptococcus pyogenes infection in human causing rheumatic heart disease. The mga gene of S. pyogenes specific 24 mer ssDNA probe was covalently immobilized on SWNT through a molecular bilinker, 1-pyrenemethylamine, using carbodiimide coupling reaction. The sensor was characterized by the current-voltage (I-V) characteristic curve and scanning electron microscopy. The sensing performance of the sensor was studied with respect to changes in conductance in SWNT channel based on hybridization of the target S. pyogenes single stranded genomic DNA (ssG-DNA) to its complementary 24 mer ssDNA probe. The sensor shows negligible response to non-complementary Staphylococcus aureus ssG-DNA, confirming the specificity of the sensor only with S. pyogenes. The genosensor exhibited a linear response to S. pyogenes G-DNA from 1 to1000 ng ml-1 with a limit of detection of 0.16 ng ml-1.

Singh, Swati; Kumar, Ashok; Khare, Shashi; Mulchandani, Ashok; Rajesh

2014-11-01

223

Identification and characterization of the heme-binding proteins SeShp and SeHtsA of Streptococcus equi subspecies equi  

Microsoft Academic Search

BACKGROUND: Heme is a preferred iron source of bacterial pathogens. Streptococcus equi subspecies equi is a bacterial pathogen that causes strangles in horses. Whether S. equi has a heme acquisition transporter is unknown. RESULTS: An S. equi genome database was blasted with the heme binding proteins Shp and HtsA of Streptococcus pyogenes, and found that S. equi has the homologue

Tyler K Nygaard; Mengyao Liu; Michael J McClure; Benfang Lei

2006-01-01

224

Attachment of capsular polysaccharide to the cell wall of Streptococcus pneumoniae type 2 is required for invasive disease.  

PubMed

The capacity of Streptococcus pneumoniae to produce capsular polysaccharide (CPS) is essential for virulence. The CPS biosynthesis proteins CpsB, CpsC, and CpsD function to regulate CPS production via tyrosine phosphorylation of CpsD. This mechanism of regulating CPS production is important for enabling S. pneumoniae to cause invasive disease. Here, we identify mutations affecting the attachment of CPS to the cell wall. These mutations were located in cpsC, such that CpsC functioned independently from CpsD tyrosine phosphorylation. These mutants produced WT levels of CPS, but were unable to cause bacteremia in mice after intranasal challenge. This finding suggests that cell-wall attachment of CPS is essential for invasive pneumococcal disease; production of WT levels of CPS alone is not sufficient. We also show that cpsB mutants, which lack the phosphotyrosine-protein phosphatase, produced less CPS than the WT strain, but attached substantially more CPS to their cell wall. Thus, the phosphorylated form of CpsD promotes attachment of CPS to the cell wall. PMID:16707578

Morona, Judy K; Morona, Renato; Paton, James C

2006-05-30

225

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

226

Streptococcus pyogenes Sternoclavicular Septic Arthritis in a Healthy Adult.  

PubMed

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

2014-12-01

227

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

228

The Core Promoter of the Capsule Operon of Streptococcus pneumoniae Is Necessary for Colonization and Invasive Disease  

PubMed Central

Streptococcus pneumoniae is a commensal of the human nasopharynx but can cause invasive diseases, including otitis media, pneumonia, sepsis, and meningitis. The capsular polysaccharide (capsule) is a critical virulence factor required for both asymptomatic colonization and invasive disease, yet the expression level is different in each anatomical site. During colonization, reduced levels of capsule promote binding to the host epithelium and biofilm formation, while during systemic infection, increased capsule is required to evade opsonophagocytosis. How this regulation of capsule expression occurs is incompletely understood. To investigate the contribution of transcriptional regulation on capsule level in the serotype 4 strain TIGR4, we constructed two mutants harboring a constitutive promoter that was either comparably weaker (Pcat) or stronger (PtRNAGlu) than the wild-type (WT) capsule promoter, Pcps. Mild reductions in cpsA and cpsE transcript levels in the Pcat promoter mutant resulted in a 2-fold reduction in total amounts of capsule and in avirulence in murine models of lung and blood infection. Additionally, the PtRNAGlu mutant revealed that, despite expressing enhanced levels of cpsA and cpsE and possessing levels of capsule comparable to those of WT TIGR4, it was still significantly attenuated in all tested in vivo niches. Further analysis using chimeric promoter mutants revealed that the WT ?10 and ?35 boxes are required for optimal nasopharyngeal colonization and virulence. These data support the hypothesis that dynamic transcriptional regulation of the capsule operon is required and that the core promoter region plays a central role in fine-tuning levels of capsule to promote colonization and invasive disease. PMID:24478084

Shainheit, Mara G.; Mulé, Matthew

2014-01-01

229

Dynamic changes in the Streptococcus pneumoniae transcriptome during transition from biofilm formation to invasive disease upon influenza A virus infection.  

PubMed

Streptococcus pneumoniae is a leading cause of infectious disease globally. Nasopharyngeal colonization occurs in biofilms and precedes infection. Prior studies have indicated that biofilm-derived pneumococci are avirulent. However, influenza A virus (IAV) infection releases virulent pneumococci from biofilms in vitro and in vivo. Triggers of dispersal include IAV-induced changes in the nasopharynx, such as increased temperature (fever) and extracellular ATP (tissue damage). We used whole-transcriptome shotgun sequencing (RNA-seq) to compare the S. pneumoniae transcriptome in biofilms, bacteria dispersed from biofilms after exposure to IAV, febrile-range temperature, or ATP, and planktonic cells grown at 37°C. Compared with biofilm bacteria, actively dispersed S. pneumoniae, which were more virulent in invasive disease, upregulated genes involved in carbohydrate metabolism. Enzymatic assays for ATP and lactate production confirmed that dispersed pneumococci exhibited increased metabolism compared to those in biofilms. Dispersed pneumococci also upregulated genes associated with production of bacteriocins and downregulated colonization-associated genes related to competence, fratricide, and the transparent colony phenotype. IAV had the largest impact on the pneumococcal transcriptome. Similar transcriptional differences were also observed when actively dispersed bacteria were compared with avirulent planktonic bacteria. Our data demonstrate complex changes in the pneumococcal transcriptome in response to IAV-induced changes in the environment. Our data suggest that disease is caused by pneumococci that are primed to move to tissue sites with altered nutrient availability and to protect themselves from the nasopharyngeal microflora and host immune response. These data help explain pneumococcal virulence after IAV infection and have important implications for studies of S. pneumoniae pathogenesis. PMID:25135685

Pettigrew, Melinda M; Marks, Laura R; Kong, Yong; Gent, Janneane F; Roche-Hakansson, Hazeline; Hakansson, Anders P

2014-11-01

230

Actinomycetes in pyogenic liver abscess.  

PubMed

Three patients with pyogenic liver abscesses had actinomycetes cultured from aspirated pus, although it is unusual for hepatic actinomycosis to present in this way. The spectrum of bacteria found in liver abscesses appears to be changing, with the increased isolation of anaerobes partly due to improved techniques. It is important to recognise the presence of actinomycetes so that appropriate chemotherapy can be given. PMID:2502404

Logan, M N; Stanley, P J; Exley, A; Gagg, C; Farrell, I D

1989-05-01

231

Peripheral compartment innate immune response to Haemophilus influenzae and Streptococcus pneumoniae in chronic obstructive pulmonary disease patients.  

PubMed

Alterations in innate immunity that predispose to chronic obstructive pulmonary disease (COPD) exacerbations are poorly understood. We examined innate immunity gene expression in peripheral blood polymorphonuclear leukocytes (PMN) and monocytes stimulated by Haemophilus influenzae and Streptococcus pneumoniae. Thirty COPD patients (15 rapid and 15 non-rapid lung function decliners) and 15 smokers without COPD were studied. Protein expression of IL-8, IL-6, TNF-? and IFN-? (especially monocytes) increased with bacterial challenge. In monocytes stimulated with S. pneumoniae, TNF-? protein expression was higher in COPD (non-rapid decliners) than in smokers. In co-cultures of monocytes and PMN, mRNA expression of TGF-?1 and MYD88 was up-regulated, and CD14, TLR2 and IFN-? down-regulated with H. influenzae challenge. TNF-? mRNA expression was increased with H. influenzae challenge in COPD. Cytokine responses were similar between rapid and non-rapid decliners. TNF-? expression was up-regulated in non-rapid decliners in response to H. influenzae (monocytes) and S. pneumoniae (co-culture of monocytes and PMN). Exposure to bacterial pathogens causes characteristic innate immune responses in peripheral blood monocytes and PMN in COPD. Bacterial exposure significantly alters the expression of TNF-? in COPD patients, although not consistently. There did not appear to be major differences in innate immune responses between rapid and non-rapid decliners. PMID:23212542

Francis, Santiyagu M Savarimuthu; Tan, Maxine E; Fung, Pamela R; Shaw, Janet G; Semmler, Annalese Bt; Nataatmadja, Maria; Bowman, Rayleen V; Fong, Kwun M; Yang, Ian A

2013-01-01

232

Genetic diversity and virulence of novel sequence types of Streptococcus suis from diseased and healthy pigs in China  

PubMed Central

Streptococcus suis is a serious threat to swine industry and public health. In this work, a total of 62 S. suis isolates recovered from infected and healthy pigs from four provinces in northern China were classified by multilocus sequence typing into nine sequence types (STs), including six novel ones, namely, ST417, ST418, ST419, ST420, ST421, and ST422. The majority (64.5%) of these 62 isolates belong to serotype 2; all of these serotype 2 isolates can be assigned into ST1 or ST28 clonal complex, indicating at least two parallel routes of clonal dissemination of these isolates. In these serotype 2 isolates, 23 (20 from healthy pigs and three from diseased pigs) were identified as ST7 strains, which were previously characterized as the cause of streptococcal toxic shock-like syndrome. The novel ST strains lack 89 K pathogenicity island but can cause septicemia and meningitis in a mouse model, showing remarkable differences in virulence. The ST421 strain named HLB causes suppurative encephalitis. Our results highlighted the need for increased surveillance of S. suis in farm-raised pigs in northern China.

Wang, Shujie; Gao, Mingming; An, Tongqing; Liu, Yonggang; Jin, Jiamin; Wang, Gang; Jiang, Chenggang; Tu, Yabin; Hu, Shouping; Li, Jinsong; Wang, Jie; Zhou, Dongsheng; Cai, Xuehui

2015-01-01

233

Inactivation of a gene for a fibronectin-binding protein of the oral bacterium Streptococcus mutans partially impairs its adherence to fibronectin  

Microsoft Academic Search

A sequence of 1647 base pairs in length of Streptococcus mutans DNA that encodes for a 63-kDa protein with significant amino acid similarity with fibronectin-binding proteins of Streptococcus pyogenes and Streptococcus gordonii was cloned. The putative recombinant fibronectin-binding protein of S. mutans was purified using affinity chromatography and the cloned protein was used to prepare polyclonal antibodies against the recombinant

Tracey A. Miller-Torbert; Shvetank Sharma; Robert G. Holt

2008-01-01

234

VACCINES TO PREVENT STREPTOCOCCUS INIAE AND S. AGALACTIAE DISEASE IN TILAPIA OREOCHROMIS NILOTICUS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Minimizing the effects of diseases is crucial to prevent mortality, morbidity, and to promote optimal growth and feed conversion in sustained culture of warm-water fish in fresh, estuarine and marine waters. The control of diseases has been dependent on the use of therapeutics since the inception o...

235

VACCINES TO PREVENT Streptococcus iniae AND S. agalactiae DISEASE IN NILE TILAPIA Oreochromis niloticus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Minimizing the effects of disease is crucial to prevent mortality, morbidity, and to promote optimal growth and feed conversion in sustained culture of warm-water fish in fresh, estuarine and marine waters. The control of diseases has been dependent on the use of therapeutics since the inception of...

236

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

237

Diversity of Prophage DNA Regions of Streptococcus agalactiae Clonal Lineages from Adults and Neonates with Invasive Infectious Disease  

PubMed Central

The phylogenetic position and prophage DNA content of the genomes of 142 S. agalactiae (group-B streptococcus, GBS) isolates responsible for bacteremia and meningitis in adults and neonates were studied and compared. The distribution of the invasive isolates between the various serotypes, sequence types (STs) and clonal complexes (CCs) differed significantly between adult and neonatal isolates. Use of the neighbor-net algorithm with the PHI test revealed evidence for recombination in the population studied (PHI, P?=?2.01×10?6), and the recombination-mutation ratio (R/M) was 6?7. Nevertheless, the estimated R/M ratio differed between CCs. Analysis of the prophage DNA regions of the genomes of the isolates assigned 90% of the isolates to five major prophage DNA groups: A to E. The mean number of prophage DNA fragments amplified per isolate varied from 2.6 for the isolates of prophage DNA group E to 4.0 for the isolates of prophage DNA group C. The isolates from adults and neonates with invasive diseases were distributed differently between the various prophage DNA groups (P<0.00001). Group C prophage DNA fragments were found in 52% of adult invasive isolates, whereas 74% of neonatal invasive isolates had prophage DNA fragments of groups A and B. Differences in prophage DNA content were also found between serotypes, STs and CCs (P<0.00001). All the ST-1 and CC1 isolates, mostly of serotype V, belonged to the prophage DNA group C, whereas 84% of the ST-17 and CC17 isolates, all of serotype III, belonged to prophage DNA groups A and B. These data indicate that the transduction mechanisms, i.e., gene transfer from one bacterium to another by a bacteriophage, underlying genetic recombination in S. agalactiae species, are specific to each intraspecies lineage and population of strains responsible for invasive diseases in adults and neonates. PMID:21633509

Salloum, Mazen; van der Mee-Marquet, Nathalie; Valentin-Domelier, Anne-Sophie; Quentin, Roland

2011-01-01

238

Identification of Lipoprotein Homologues of Pneumococcal PsaA in the Equine Pathogens Streptococcus equi and Streptococcus zooepidemicus  

Microsoft Academic Search

Streptococcus equi and Streptococcus zooepidemicus are major etiological agents of upper and lower airway disease in horses. Despite the considerable animal suffering and economic burden associated with these diseases, the factors that contribute to the virulence of these equine pathogens have not been extensively investigated. Here we demonstrate the presence of a homologue of the Streptococcus pneumoniae PsaA protein in

DEAN J. HARRINGTON; JOANNE S. GREATED; NEIL CHANTER; IAIN C. SUTCLIFFE

2000-01-01

239

Lack of mitogenic activity of speG- and speG(dys)-positive Streptococcus dysgalactiae subspecies equisimilis isolates from patients with invasive infections.  

PubMed

In recent years, Streptococcus dysgalactiae subspecies equisimilis has been isolated with an increasing frequency as the cause of invasive streptococcal diseases. For 46 S. dysgalactiae subspecies equisimilis isolates from invasive infections and four isolates from superficial infections, the presence of emm/emmL genes and of genes encoding various different streptococcal superantigens was determined by polymerase chain reaction (PCR). Subsequently, PCR products were identified by DNA sequencing, and the expression of mRNA from superantigen genes was assessed by reverse transcriptase-PCR. The mitogenic activity of S. dysgalactiae subspecies equisimilis was assessed by [3H]thymidine incorporation into human lymphocytes and compared with that of Streptococcus agalactiae and Streptococcus pyogenes. All S. dysgalactiae subspecies equisimilis isolates studied harbored an emm/emmL gene. Only in six of the S. dysgalactiae subspecies equisimilis isolates from invasive infections, speG was detected by PCR, two of which were further identified as speGdys by sequencing of the PCR product. None of the S. dysgalactiae subspecies equisimilis isolates harbored any of the genes speA, speB, speC, speF, speH, speI, speJ, speK, speL, speM, smeZ, or ssa of S. pyogenes. In contrast to S. pyogenes, no expression of speG or speGdys mRNA, respectively, was detected in the reverse transcriptase-PCR assay for any of the speG- or speGdys-positive S. dysgalactiae subspecies equisimilis isolates. Moreover, S. dysgalactiae subspecies equisimilis and S. agalactiae revealed no or very low mitogenic activity, while S. pyogenes was a very powerful inducer of proliferative responses. These findings support the hypothesis that the pathogenicity of S. dysgalactiae subspecies equisimilis may be associated in part with the presence of emm/emmL genes, and suggest that the severity of S. dysgalactiae subspecies equisimilis invasive infections is not mediated by superantigen-induced mitogenicity. PMID:16325550

Brandt, Claudia M; Schweizer, Klaus G; Holland, Regina; Lütticken, Rudolf; Freyaldenhoven, Bettina S

2005-12-01

240

Developing oral probiotics from Streptococcus salivarius.  

PubMed

Considerable human illness can be linked to the development of oral microbiota disequilibria. The predominant oral cavity commensal, Streptococcus salivarius has emerged as an important source of safe and efficacious probiotics, capable of fostering more balanced, health-associated oral microbiota. Strain K12, the prototype S. salivarius probiotic, originally introduced to counter Streptococcus pyogenes infections, now has an expanded repertoire of health-promoting applications. K12 and several more recently proposed S. salivarius probiotics are now being applied to control diverse bacterial consortia infections including otitis media, halitosis and dental caries. Other potential applications include upregulation of immunological defenses against respiratory viral infections and treatment of oral candidosis. An overview of the key steps required for probiotic development is also presented. PMID:23231486

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

2012-12-01

241

Group A Streptococcus: a re-emergent pathogen. Infectious Diseases and Immunization Committee, Canadian Paediatric Society.  

PubMed Central

Rheumatic fever is still rare in North America but must continue to be considered in the appropriate clinical setting. Invasive or severe GABHS disease remains unusual and is unlikely to be missed by the practitioner; however, it is essential that GABHS infection be considered as a possible cause of a severe sepsis-like syndrome. Currently the routine management of GABHS infection is unchanged; however, heightened awareness of the infection's rare, more serious complications is needed. PMID:8500028

1993-01-01

242

Intraclonal Variations Among Streptococcus pneumoniae Isolates Influence the Likelihood of Invasive Disease in Children  

PubMed Central

Background.?Pneumococcal serotypes are represented by a varying number of clonal lineages with different genetic contents, potentially affecting invasiveness. However, genetic variation within the same genetic lineage may be larger than anticipated. Methods.?A total of 715 invasive and carriage isolates from children in the same region and during the same period were compared using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Bacterial genome sequencing, functional assays, and in vivo virulence mice studies were performed. Results.?Clonal types of the same serotype but also intraclonal variants within clonal complexes (CCs) showed differences in invasive-disease potential. CC138, a common CC, was divided into several PFGE patterns, partly explained by number, location, and type of temperate bacteriophages. Whole-genome sequencing of 4 CC138 isolates representing PFGE clones with different invasive-disease potentials revealed intraclonal sequence variations of the virulence-associated proteins pneumococcal surface protein A (PspA) and pneumococcal choline-binding protein C (PspC). A carrier isolate lacking PcpA exhibited decreased virulence in mice, and there was a differential binding of human factor H, depending on invasiveness. Conclusions.?Pneumococcal clonal types but also intraclonal variants exhibited different invasive-disease potentials in children. Intraclonal variants, reflecting different prophage contents, showed differences in major surface antigens. This suggests ongoing immune selection, such as that due to PspC-mediated complement resistance through varied human factor H binding, that may affect invasiveness in children. PMID:24009156

Browall, Sarah; Norman, Martin; Tångrot, Jeanette; Galanis, Ilias; Sjöström, Karin; Dagerhamn, Jessica; Hellberg, Christel; Pathak, Anuj; Spadafina, Tiziana; Sandgren, Andreas; Bättig, Patrick; Franzén, Oscar; Andersson, Björn; Örtqvist, Åke; Normark, Staffan; Henriques-Normark, Birgitta

2014-01-01

243

Group B streptococcus cystitis presenting in a diabetic patient with a massive abdominopelvic abscess: a case report  

PubMed Central

Introduction Streptococcus agalactiae or group B streptococcus is a Gram-positive pathogen that is typically associated with neonatal disease and infection in pregnant women. Group B streptococcus also causes invasive infections in non-pregnant adults including urinary tract infections. The spectrum of urinary tract infections caused by group B streptococcus includes cystitis, pyelonephritis, urosepsis and asymptomatic bacteriuria, which is particularly common among elderly individuals. A rare form of invasive group B streptococcus infection in adults is secondary abscess. Here, we present the first reported case of a patient who developed an unusual, massive abdominopelvic abscess secondary to acute group B streptococcus urinary tract infection. Case presentation A 46-year-old African-American woman presented to the University Emergency Department complaining of urinary tract infection symptoms and severe abdominal pain. Diagnostic imaging by transvaginal ultrasound and computed tomography revealed a massive peripherally-enhancing, low-attenuating fluid collection within her pelvis. The patient’s abdominopelvic abscess was drained by ultrasound-guided drainage and this yielded a septic aspirate that was culture positive for abundant S. agalactiae. A recent history of urinary tract infection symptoms in the patient suggested that her abscess developed secondary to cystitis. Complete resolution of the abscess as a favorable outcome was achieved in this case following surgical drainage and appropriate antimicrobial therapy. Conclusion Acute bacterial urinary tract infection leading to an abdominopelvic abscess has not previously been reported in the literature. This case report defines a new disease etiology associated with acute streptococcal cystitis and it will be of interest in cases of urinary tract infections where there is an association with abdominal and/or pelvic pain. A brief review of the literature on unusual secondary abscesses due to group B streptococcus is provided alongside this case to highlight the clinical significance and prognoses of these rare infections. Finally, this case emphasizes the requirement to distinguish unusual etiologies of pyogenic abscesses in order to guide successful clinical management and to treat patients with antibiotics active against the causal organism. PMID:22883571

2012-01-01

244

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

245

IdeE, an IgG-endopeptidase of Streptococcus equi ssp. equi.  

PubMed

Streptococcus equi ssp. equi is the causative agent of strangles, a highly contagious and serious disease in the upper respiratory tract of horses. The present study describes the characterization of IdeE, a homolog of the secreted IgG-specific protease IdeS/Mac of Streptococcus pyogenes. The activity of IdeE is compared with the activity of IdeZ, the corresponding enzyme of the closely related S. equi ssp. zooepidemicus. A study of the proteolytic activity of recombinant IdeE and IdeZ on IgG from a selection of mammals shows that only antibodies containing the substrate site of IdeS/Mac are cleaved, indicating that the specificities of these enzymes are similar. Interestingly, IgG from horse is less effectively cleaved than IgG from e.g. dog or humans, as the dominating IgG isotype in horse sera (IgG4) lacks a distinct substrate site for IdeE/IdeZ. IgG-degradation is observed when S. equi ssp. equi is grown in the presence of horse serum, but not when grown with purified IgG. As the fraction of degraded IgG contains IgG4, the observed activity might be due to the expression of an unknown enzyme rather than IdeE. In a similar assay, no proteolysis of IgG was detected in the growth media of S. equi ssp. zooepidemicus. PMID:16923080

Lannergård, Jonas; Guss, Bengt

2006-09-01

246

Characterization and immunogenicity of pyrogenic mitogens SePE-H and SePE-I of Streptococcus equi  

Microsoft Academic Search

Two pyrogenic mitogens, SePE-H and SePE-I, were characterized in Streptococcus equi, the cause of equine strangles. SePE-H and SePE-I have molecular masses of 27.5 and 29.5 kDa, respectively, and each is almost identical to its counterpart in Streptococcus pyogenes M1. Both genes are adjacent to a gene encoding a phage muramidase of 49.7 kDa and are located immediately downstream from

S. C. Artiushin; J. F. Timoney; A. S. Sheoran; S. K. Muthupalani

2002-01-01

247

ORIGINAL ARTICLE Conserved anchorless surface proteins as group A  

E-print Network

March 2012 # Springer-Verlag 2012 Abstract Streptococcus pyogenes (group A Streptococcus (GAS)) causes antigens as promising vaccine candidates for the prevention of GAS disease. Keywords Streptococcus pyogenes A Streptococcus ((GAS), S. pyogenes) is a major human pathogen causing the ubiquitous infections of pharyngitis

Nizet, Victor

248

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

PubMed Central

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

Lindmark, Hans; Guss, Bengt

1999-01-01

249

Molecular typing methods for outbreak detection and surveillance of invasive disease caused by Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae, a review  

PubMed Central

Invasive disease caused by the encapsulated bacteria Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae remains an important cause of morbidity and mortality worldwide, despite the introduction of successful conjugate polysaccharide vaccines that target disease-associated strains. In addition, resistance, or more accurately reduced susceptibility, to therapeutic antibiotics is spreading in populations of these organisms. There is therefore a continuing requirement for the surveillance of vaccine and non-vaccine antigens and antibiotic susceptibilities among isolates from invasive disease, which is only partially met by conventional methods. This need can be met with molecular and especially nucleotide sequence-based typing methods, which are fully developed in the case of N. meningitidis and which could be more widely deployed in clinical laboratories for S. pneumoniae and H. influenzae. PMID:21622526

Harrison, Odile B.; Brueggemann, Angela B.; Caugant, Dominique A.; van der Ende, Arie; Frosch, Matthias; Gray, Stephen; Heuberger, Sigrid; Krizova, Paula; Olcen, Per; Slack, Mary; Taha, Muhamed-Kheir; Maiden, Martin C. J

2014-01-01

250

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

Code of Federal Regulations, 2014 CFR

...identify antibodies to Streptococcus spp. exoenzyme in serum. The identification aids in the diagnosis of disease caused by bacteria belonging to the genus Streptococcus and provides epidemiological information on these diseases. Pathogenic...

2014-04-01

251

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

Code of Federal Regulations, 2013 CFR

...identify antibodies to Streptococcus spp. exoenzyme in serum. The identification aids in the diagnosis of disease caused by bacteria belonging to the genus Streptococcus and provides epidemiological information on these diseases. Pathogenic...

2013-04-01

252

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

Code of Federal Regulations, 2012 CFR

...identify antibodies to Streptococcus spp. exoenzyme in serum. The identification aids in the diagnosis of disease caused by bacteria belonging to the genus Streptococcus and provides epidemiological information on these diseases. Pathogenic...

2012-04-01

253

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

Code of Federal Regulations, 2011 CFR

...identify antibodies to Streptococcus spp. exoenzyme in serum. The identification aids in the diagnosis of disease caused by bacteria belonging to the genus Streptococcus and provides epidemiological information on these diseases. Pathogenic...

2011-04-01

254

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

255

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

256

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

257

Estimation of the invasive disease potential of Streptococcus pneumoniae in children by the use of direct capsular typing in clinical specimens.  

PubMed

Traditionally, invasiveness indexes have been based on culture methods. We aimed to establish a new classification of the invasive disease potential of pneumococcal serotypes causing invasive pediatric disease in the era of conjugate vaccines in Catalonia, Spain, by adding capsular typing of Streptococcus pneumoniae in direct sample. Two samples of children attended at the University Hospital Sant Joan de Déu (Barcelona, Spain) between 2007 and 2011 were compared: a first sample of 358 children with invasive pneumococcal disease and a second sample of 402 pneumococcal nasopharyngeal carriers selected from 714 healthy children admitted for minor surgical procedures. The most common invasive serotypes were 1 (20.1 %, n?=?72), 19A (13.9 %, n?=?50), 3 (12.3 %, n?=?44), and 7FA (7.5 %, n?=?27), whereas the most common serotypes in carriage were 19A (8.7 %, n?=?38), 10FC33C (7.8 %, n?=?34), 6C (6.9 %, n?=?30), and 19FBC (5.5 %, n?=?24). We detected a rate of cocolonization of 26.4 % (n?=?89) among the 336 samples serotyped in the carriers population. Serotypes 1, 3, and 7FA were significantly associated with high invasiveness. Serotypes 6C, 10FC33C, 23A, 35B, 19FBC, 21, 11AD, 15BC, 23B, 34, and 6A were significantly associated with low invasiveness. Our results proved that the use of molecular techniques in direct sample for both the detection and the capsular identification of Streptococcus pneumoniae is very useful to obtain a more accurate calculation of the invasiveness of the different pneumococcal serotypes. PMID:25413925

Del Amo, E; Selva, L; de Sevilla, M F; Ciruela, P; Brotons, P; Triviño, M; Hernandez, S; Garcia-Garcia, J J; Dominguez, Á; Muñoz-Almagro, C

2015-04-01

258

Getting to grips with strangles: an effective multi-component recombinant vaccine for the protection of horses from Streptococcus equi infection.  

PubMed

Streptococcus equi subspecies equi (S. equi) is a clonal, equine host-adapted pathogen of global importance that causes a suppurative lymphodendopathy of the head and neck, more commonly known as Strangles. The disease is highly prevalent, can be severe and is highly contagious. Antibiotic treatment is usually ineffective. Live attenuated vaccine strains of S. equi have shown adverse reactions and they suffer from a short duration of immunity. Thus, a safe and effective vaccine against S. equi is highly desirable. The bacterium shows only limited genetic diversity and an effective vaccine could confer broad protection to horses throughout the world. Welsh mountain ponies (n = 7) vaccinated with a combination of seven recombinant S. equi proteins were significantly protected from experimental infection by S. equi, resembling the spontaneous disease. Vaccinated horses had significantly reduced incidence of lymph node swelling (p = 0.0013) lymph node abscessation (p = 0.00001), fewer days of pyrexia (p = 0.0001), reduced pathology scoring (p = 0.005) and lower bacterial recovery from lymph nodes (p = 0.004) when compared with non-vaccinated horses (n = 7). Six of 7 vaccinated horses were protected whereas all 7 non-vaccinated became infected. The protective antigens consisted of five surface localized proteins and two IgG endopeptidases. A second vaccination trial (n = 7+7), in which the IgG endopeptidases were omitted, demonstrated only partial protection against S. equi, highlighting an important role for these vaccine components in establishing a protective immune response. S. equi shares >80% sequence identity with Streptococcus pyogenes. Several of the components utilized here have counterparts in S. pyogenes, suggesting that our findings have broader implications for the prevention of infection with this important human pathogen. This is one of only a few demonstrations of protection from streptococcal infection conferred by a recombinant multi-component subunit vaccine in a natural host. PMID:19763180

Guss, Bengt; Flock, Margareta; Frykberg, Lars; Waller, Andrew S; Robinson, Carl; Smith, Ken C; Flock, Jan-Ingmar

2009-09-01

259

Getting to Grips with Strangles: An Effective Multi-Component Recombinant Vaccine for the Protection of Horses from Streptococcus equi Infection  

PubMed Central

Streptococcus equi subspecies equi (S. equi) is a clonal, equine host-adapted pathogen of global importance that causes a suppurative lymphodendopathy of the head and neck, more commonly known as Strangles. The disease is highly prevalent, can be severe and is highly contagious. Antibiotic treatment is usually ineffective. Live attenuated vaccine strains of S. equi have shown adverse reactions and they suffer from a short duration of immunity. Thus, a safe and effective vaccine against S. equi is highly desirable. The bacterium shows only limited genetic diversity and an effective vaccine could confer broad protection to horses throughout the world. Welsh mountain ponies (n?=?7) vaccinated with a combination of seven recombinant S. equi proteins were significantly protected from experimental infection by S. equi, resembling the spontaneous disease. Vaccinated horses had significantly reduced incidence of lymph node swelling (p?=?0.0013) lymph node abscessation (p?=?0.00001), fewer days of pyrexia (p?=?0.0001), reduced pathology scoring (p?=?0.005) and lower bacterial recovery from lymph nodes (p?=?0.004) when compared with non-vaccinated horses (n?=?7). Six of 7 vaccinated horses were protected whereas all 7 non-vaccinated became infected. The protective antigens consisted of five surface localized proteins and two IgG endopeptidases. A second vaccination trial (n?=?7+7), in which the IgG endopeptidases were omitted, demonstrated only partial protection against S. equi, highlighting an important role for these vaccine components in establishing a protective immune response. S. equi shares >80% sequence identity with Streptococcus pyogenes. Several of the components utilized here have counterparts in S. pyogenes, suggesting that our findings have broader implications for the prevention of infection with this important human pathogen. This is one of only a few demonstrations of protection from streptococcal infection conferred by a recombinant multi-component subunit vaccine in a natural host. PMID:19763180

Guss, Bengt; Flock, Margareta; Frykberg, Lars; Waller, Andrew S.; Robinson, Carl; Smith, Ken C.; Flock, Jan-Ingmar

2009-01-01

260

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

PubMed Central

Background Understanding the distribution of disease in wildlife is key to predicting the impact of emerging zoonotic one health concerns, especially for wildlife species with extensive human and livestock interfaces. The widespread distribution and complex interactions of white-tailed deer (Odocoileus virginianus) with humans suggest deer population health and management may have implications beyond stewardship of the animals. The intracranial abscessation suppurative meningitis (IASM) disease complex in deer has been linked to Arcanobacterium pyogenes, an under-diagnosed and often misdiagnosed organism considered commensal in domestic livestock but associated with serious disease in numerous species, including humans. Methods Our study used standard bacterial culture techniques to assess A. pyogenes prevalence among male deer sampled across six physiogeographic regions in Maryland and male and female deer in the Upper Eastern Shore under Traditional Deer Management (TDM) and Quality Deer Management (QDM), a management protocol that alters population demographics in favor of older male deer. Samples were collected from antler pedicles for males, the top of the head where pedicles would be if present for females, or the whole dorsal frontal area of the head for neonates. We collected nasal samples from all animals by swabbing the nasopharyngeal membranes. A gram stain and catalase test were conducted, and aerobic bacteria were identified to genus and species when possible. We evaluated the effect of region on whether deer carried A. pyogenes using Pearson's chi-square test with Yates’ continuity correction. For the white-tailed deer management study, we tested whether site, age class and sex predisposed animals to carrying A. pyogenes using binary logistic regression. Results A. pyogenes was detected on deer in three of the six regions studied, and was common in only one region, the Upper Eastern Shore. In the Upper Eastern Shore, 45% and 66% of antler and nasal swabs from deer were positive for A. pyogenes, respectively. On the Upper Eastern Shore, prevalence of A. pyogenes cultured from deer did not differ between management areas, and was abundant among both sexes and across all age classes. No A. pyogenes was cultured from a small sample of neonates. Conclusion Our study indicates A. pyogenes may be carried widely among white-tailed deer regardless of sex or age class, but we found no evidence the pathogen is acquired in utero. The distribution of A. pyogenes across regions and concentration in a region with low livestock levels suggests the potential for localized endemicity of the organism and the possibility that deer may serve as a maintenance reservoir for an emerging one health concern. PMID:23930157

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

2013-01-01

261

Streptococcus pneumoniae serotype 6C presenting as recurrent prosthetic knee joint infection in a patient with a history of congenital asplenia and underlying autoimmune disease: a case report and literature review.  

PubMed

This report describes a case of primary Streptococcus pneumoniae bacteremia with prosthetic joint infection caused by serotype 6C with recurrent infection in a patient with a history of congenital asplenia and underlying autoimmune disease. Isolates from the primary and recurrent infections were determined to be indistinguishable by pulsed-field gel electrophoresis. This study expands the conditions associated with recurrent invasive pneumococcal disease caused by serotype 6C. PMID:24139971

Roberts, Amity L; Hewlett, Angela L; Yu, Jigui; Nahm, Moon H; Fey, Paul D; Iwen, Peter C

2013-12-01

262

Crystal structure of the zymogen form of the group A Streptococcus virulence factor SpeB: an integrin-binding cysteine protease.  

PubMed

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 form of SpeB at 1.6-A resolution, reveals that the protein is a distant homologue of the papain superfamily that includes the mammalian cathepsins B, K, L, and S. Despite negligible sequence identity, the protease portion has the canonical papain fold, albeit with major loop insertions and deletions. The catalytic site differs from most other cysteine proteases in that it lacks the Asn residue of the Cys-His-Asn triad. The prosegment has a unique fold and inactivation mechanism that involves displacement of the catalytically essential His residue by a loop inserted into the active site. The structure also reveals the surface location of an integrin-binding Arg-Gly-Asp (RGD) motif that is a feature unique to SpeB among cysteine proteases and is linked to the pathogenesis of the most invasive strains of S. pyogenes. PMID:10681429

Kagawa, T F; Cooney, J C; Baker, H M; McSweeney, S; Liu, M; Gubba, S; Musser, J M; Baker, E N

2000-02-29

263

mefE is necessary for the erythromycin-resistant M phenotype in Streptococcus pneumoniae.  

PubMed Central

Recently, it was shown that a significant number of erythromycin-resistant Streptococcus pneumoniae and Streptococcus pyogenes strains contain a determinant that mediates resistance via a putative efflux pump. The gene encoding the erythromycin-resistant determinant was cloned and sequenced from three strains of S. pneumoniae bearing the M phenotype (macrolide resistant but clindamycin and streptogramin B susceptible). The DNA sequences of mefE were nearly identical, with only 2-nucleotide differences between genes from any two strains. When the mefE sequences were compared to the mefA sequence from S. pyogenes, the two genes were found to be closely related (90% identity). Strains of S. pneumoniae were constructed to confirm that mefE is necessary to confer erythromycin resistance and to explore the substrate specificity of the pump; no substrates other than 14- and 15-membered macrolides were identified. PMID:9333056

Tait-Kamradt, A; Clancy, J; Cronan, M; Dib-Hajj, F; Wondrack, L; Yuan, W; Sutcliffe, J

1997-01-01

264

Molecular epidemiology of group A streptococcus causing scarlet fever in northern Taiwan, 2001–2002  

Microsoft Academic Search

In this study, 830 Streptococcus pyogenes isolates collected between 2001 and 2002 from patients with scarlet fever in northern Taiwan were analyzed by M protein gene (emm) sequence typing, pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility testing. A total of 21 emm types and 56 PFGE patterns were identified. The most frequent emm types were emm1 (29.2%), emm4 (24.1%), emm12

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

2007-01-01

265

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

266

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

267

Characterization and Protective Immunogenicity of the SzM Protein of Streptococcus zooepidemicus NC78 from a Clonal Outbreak of Equine Respiratory Disease  

PubMed Central

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 (SzMNC78) 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 SzMNC78. 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, SzMNC78 reacted with convalescent-phase sera from horses with respiratory disease associated with strains of S. zooepidemicus. SzMNC78 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 SzMNC78. 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

2013-01-01

268

Gold-mercaptopropionic acid-polyethylenimine composite based DNA sensor for early detection of rheumatic heart disease.  

PubMed

The first gold-mercaptopropionic acid-polyethylenimine composite based electrochemical DNA biosensor was fabricated for the early detection of Streptococcus pyogenes infection in humans causing rheumatic heart disease (heart valve damage). No biosensor is available for the detection of rheumatic heart disease (RHD). Therefore, the mga gene based sensor was developed by the covalent immobilization of a 5'-carboxyl modified single stranded DNA probe onto the gold composite electrode. The immobilized probe was hybridized with the genomic DNA (G-DNA) of S. pyogenes from throat swabs and the electrochemical response was measured by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance (EI). Covalent immobilization of the probe onto the gold composite and its hybridization with G-DNA was characterized by FTIR and SEM. The sensitivity of the sensor was 110.25 ?A cm(-2) ng(-1) with DPV and the lower limit of detection was 10 pg per 6 ?L. The sensor was validated with patient throat swab samples and results were compared with available methods. The sensor is highly specific to S. pyogenes and can prevent damage to heart valves by the early detection of the infection in only 30 min. PMID:24875529

Singh, Swati; Kaushal, Ankur; Khare, Shashi; Kumar, Pradeep; Kumar, Ashok

2014-07-21

269

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

PubMed Central

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

2013-01-01

270

Contrast-enhanced ultrasound in different stages of pyogenic liver abscess.  

PubMed

To enable sonographic classification of different stages of pyogenic liver abscesses, sonographic findings in 86 patients with 113 pyogenic liver abscesses were retrospectively analyzed and compared with established pathomorphologic descriptions of the disease. The typical findings in contrast-enhanced ultrasound were sub-segmental hyperemia (93/113, 82%) and necrosis with a hyperemic margin (109/113, 96%) in the arterial phase and a washout of liver tissue surrounding necrosis in the late phase (101/113, 89%). Four different sonomorphologic stages of pyogenic liver abscess were identified. Stage I was defined by focal inflammation without necrosis (n = 2); stage II by focal clusters of micro-abscesses appearing to coalesce (n = 41); and stage III by a single cavity with or without capsule (n = 64). Stage IV was defined as numerous small abscesses scattered all over the liver (n = 6). The results indicate that contrast-enhanced ultrasound is suitable for classifying different stages of pyogenic liver abscesses. Knowledge of the described morphologic patterns influences therapeutic decisions and helps distinguish abscesses from other liver masses. PMID:25701525

Kunze, Georg; Staritz, Martin; Köhler, Michael

2015-04-01

271

21 CFR 866.3740 - Streptococcus spp. serological reagents.  

Code of Federal Regulations, 2012 CFR

...spp. from cultured isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by bacteria belonging to the genus Streptococcus and provides epidemiological information on these diseases. Pathogenic...

2012-04-01

272

[The importance of Streptococcus bovis systemic infections].  

PubMed

Streptococcus bovis is relatively common cause of bacteremia and endocarditis, especially in older persons, or in patients that have some kind of chronic disease. These infections are frequently connected with malignant, potentially malignant, or benign colorectal neoplasia. Hematogenous dissemination of Streptococcus bovis could result with various clinical manifestations, namely purulent meningitis, brain abscess, osteomyelitis, spondylodiscitis, and many different kinds of infections in AIDS patients are reported. In this report, two patients hospitalized at the Departement of Infectious Diseases at the General Hospital "Dr. Josip Bencevi?" in Slavonski Brod are presented. The first patient was addmited to the hospital because of fever of unknown origin, and in his blood cultures, Streptococcus bovis was isolated. He was an older man, who had undergone prostatectomy due prostatic adenoma several years before. The other patient, previously completely healthy younger man, suffered purulent meningitis caused by the same microorganism. Colon endoscopy was performed in both patients and it revealed colon polyps. Histologically, in both cases, those were benign neoplasia. In Croatia, until this report, there have been no other reports about patients suffering systemic Streptococcus bovis infections. At the same time, this report describes Streptococcus bovis purulent meningitis in a previously healthy adult, which is also extremely rare in the medical literature. Since Streptococcus bovis infections are associated with colon carcinoma, it is imperative to perform colonoscopy in each patient suffering infection with this germ, and to consider him as a high risk patient for developing colon cancer. PMID:17087134

Pandak, Nenad; Tomi?-Paradzik, Maja; Krizanovi?, Branka; Fornet-Sapcevski, Josipa

2006-01-01

273

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

274

40 CFR 725.421 - Introduced genetic material.  

Code of Federal Regulations, 2010 CFR

...monocytogenes Listeriolysin (A B) Streptococcus pneumoniae Pneumolysin Streptococcus pyogene Streptolysin O (SLO) ...Leucocidin (leukocidin, cytotoxin) Streptococcus pyogenes Streptolysin S (SLS);...

2010-07-01

275

40 CFR 725.421 - Introduced genetic material.  

Code of Federal Regulations, 2013 CFR

...monocytogenes Listeriolysin (A B) Streptococcus pneumoniae Pneumolysin Streptococcus pyogene Streptolysin O (SLO) ...Leucocidin (leukocidin, cytotoxin) Streptococcus pyogenes Streptolysin S (SLS);...

2013-07-01

276

40 CFR 725.421 - Introduced genetic material.  

Code of Federal Regulations, 2012 CFR

...monocytogenes Listeriolysin (A B) Streptococcus pneumoniae Pneumolysin Streptococcus pyogene Streptolysin O (SLO) ...Leucocidin (leukocidin, cytotoxin) Streptococcus pyogenes Streptolysin S (SLS);...

2012-07-01

277

40 CFR 725.421 - Introduced genetic material.  

Code of Federal Regulations, 2014 CFR

...monocytogenes Listeriolysin (A B) Streptococcus pneumoniae Pneumolysin Streptococcus pyogene Streptolysin O (SLO) ...Leucocidin (leukocidin, cytotoxin) Streptococcus pyogenes Streptolysin S (SLS);...

2014-07-01

278

40 CFR 725.421 - Introduced genetic material.  

Code of Federal Regulations, 2011 CFR

...monocytogenes Listeriolysin (A B) Streptococcus pneumoniae Pneumolysin Streptococcus pyogene Streptolysin O (SLO) ...Leucocidin (leukocidin, cytotoxin) Streptococcus pyogenes Streptolysin S (SLS);...

2011-07-01

279

Evolutionary pathway to increased virulence and epidemic group A Streptococcus disease derived from 3,615 genome sequences  

PubMed Central

We sequenced the genomes of 3,615 strains of serotype Emm protein 1 (M1) group A Streptococcus to unravel the nature and timing of molecular events contributing to the emergence, dissemination, and genetic diversification of an unusually virulent clone that now causes epidemic human infections worldwide. We discovered that the contemporary epidemic clone emerged in stepwise fashion from a precursor cell that first contained the phage encoding an extracellular DNase virulence factor (streptococcal DNase D2, SdaD2) and subsequently acquired the phage encoding the SpeA1 variant of the streptococcal pyrogenic exotoxin A superantigen. The SpeA2 toxin variant evolved from SpeA1 by a single-nucleotide change in the M1 progenitor strain before acquisition by horizontal gene transfer of a large chromosomal region encoding secreted toxins NAD+-glycohydrolase and streptolysin O. Acquisition of this 36-kb region in the early 1980s into just one cell containing the phage-encoded sdaD2 and speA2 genes was the final major molecular event preceding the emergence and rapid intercontinental spread of the contemporary epidemic clone. Thus, we resolve a decades-old controversy about the type and sequence of genomic alterations that produced this explosive epidemic. Analysis of comprehensive, population-based contemporary invasive strains from seven countries identified strong patterns of temporal population structure. Compared with a preepidemic reference strain, the contemporary clone is significantly more virulent in nonhuman primate models of pharyngitis and necrotizing fasciitis. A key finding is that the molecular evolutionary events transpiring in just one bacterial cell ultimately have produced millions of human infections worldwide. PMID:24733896

Nasser, Waleed; Beres, Stephen B.; Olsen, Randall J.; Dean, Melissa A.; Rice, Kelsey A.; Long, S. Wesley; Kristinsson, Karl G.; Gottfredsson, Magnus; Vuopio, Jaana; Raisanen, Kati; Caugant, Dominique A.; Steinbakk, Martin; Low, Donald E.; McGeer, Allison; Darenberg, Jessica; Henriques-Normark, Birgitta; Van Beneden, Chris A.; Hoffmann, Steen; Musser, James M.

2014-01-01

280

Fusobacterium necrophorum and Actinomyces pyogenes associated facial and mandibular abscesses in blue duiker.  

PubMed

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. Fusobacterium necrophorum was present in eight and Bacteroides sp. was found in seven animals; other genera of isolated bacteria included: Streptococcus (from two animals), Lactobacillus (one), Staphylococcus (one) and Actinomyces (two). Eight (67%) of affected animals were less than or equal to 2 yr of age. Facial soft tissues and mandibles were the tissues most often affected. Tissues within the oral cavity were not affected at the time of presentation. A common finding, not reported in other host species with necrobacillosis, was the presence of nondestructive mandibular proliferation. PMID:2761010

Roeder, B L; Chengappa, M M; Lechtenberg, K F; Nagaraja, T G; Varga, G A

1989-07-01

281

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

PubMed

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

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

2011-09-01

282

Identification of Three Novel Superantigen-Encoding Genes in Streptococcus equi subsp. zooepidemicus, szeF, szeN, and szeP? †  

PubMed Central

The acquisition of superantigen-encoding genes by Streptococcus pyogenes has been associated with increased morbidity and mortality in humans, and the gain of four superantigens by Streptococcus equi is linked to the evolution of this host-restricted pathogen from an ancestral strain of the opportunistic pathogen Streptococcus equi subsp. zooepidemicus. A recent study determined that the culture supernatants of several S. equi subsp. zooepidemicus strains possessed mitogenic activity but lacked known superantigen-encoding genes. Here, we report the identification and activities of three novel superantigen-encoding genes. The products of szeF, szeN, and szeP share 59%, 49%, and 34% amino acid sequence identity with SPEH, SPEM, and SPEL, respectively. Recombinant SzeF, SzeN, and SzeP stimulated the proliferation of equine peripheral blood mononuclear cells, and tumor necrosis factor alpha (TNF-?) and gamma interferon (IFN-?) production, in vitro. Although none of these superantigen genes were encoded within functional prophage elements, szeN and szeP were located next to a prophage remnant, suggesting that they were acquired by horizontal transfer. Eighty-one of 165 diverse S. equi subsp. zooepidemicus strains screened, including 7 out of 15 isolates from cases of disease in humans, contained at least one of these new superantigen-encoding genes. The presence of szeN or szeP, but not szeF, was significantly associated with mitogenic activity in the S. equi subsp. zooepidemicus population (P < 0.000001, P < 0.000001, and P = 0.104, respectively). We conclude that horizontal transfer of these novel superantigens from and within the diverse S. equi subsp. zooepidemicus population is likely to have implications for veterinary and human disease. PMID:20713629

Paillot, Romain; Darby, Alistair C.; Robinson, Carl; Wright, Nicola L.; Steward, Karen F.; Anderson, Emma; Webb, Katy; Holden, Matthew T. G.; Efstratiou, Androulla; Broughton, Karen; Jolley, Keith A.; Priestnall, Simon L.; Marotti Campi, Maria C.; Hughes, Margaret A.; Radford, Alan; Erles, Kerstin; Waller, Andrew S.

2010-01-01

283

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.

284

Human Streptococcus agalactiae isolate in Nile tilapia (Oreochromis niloticus)  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

285

Draft Genome Sequence of Streptococcus agalactiae PR06.  

PubMed

Streptococcus agalactiae (group B streptococcus [GBS]) is a Gram-positive bacterium that was first recognized as a causative agent of bovine mastitis. S. agalactiae has subsequently emerged as a significant cause of human diseases. Here, we report the draft genome sequence of S. agalactiae PR06, which was isolated from a septicemic patient in a local hospital in Malaysia. PMID:23766409

Mz, Irma Syakina; Teh, L K; Salleh, M Z

2013-01-01

286

Recombinant hyaluronate associated protein as a protective immunogen against Streptococcus equi and Streptococcus zooepidemicus challenge in mice  

Microsoft Academic Search

The capsule of Streptococcus equi, the cause of strangles, and Streptococcus zooepidemicus, associated with equine lower airway disease, plays an important role in evasion of phagocytosis by polymorphonuclear leucocytes. It is composed of hyaluronate, making it non-immunogenic. A hyaluronate associated protein (HAP) fromS. equisimilis , whose gene has been sequenced [1], was investigated (a) for its presence in S. equi

Neil Chanter; Chantelle L Ward; Nicola C Talbot; Julia A Flanagan; Matthew Binns; Stephen B Houghton; Kenneth C Smith; Jennifer A Mumford

1999-01-01

287

Contribution of Each of Four Superantigens to Streptococcus equi-Induced Mitogenicity, Gamma Interferon Synthesis, and Immunity ?  

PubMed Central

Streptococcus equi is the causative agent of strangles, the most frequently diagnosed infectious disease of horses worldwide. The disease is characterized by abscessation and swelling of the lymph nodes of the head and neck, which can literally strangle the horse to death. S. equi produces four recently acquired phage-associated bacterial superantigens (sAgs; SeeH, SeeI, SeeL, and SeeM) that share homology with the mitogenic toxins of Streptococcus pyogenes. The aim of this study was to characterize the contribution of each of these S. equi sAgs to mitogenic activity in vitro and quantify the sAg-neutralizing capacity of sera from naturally infected horses in order to better understand their role in pathogenicity. Each of the sAgs was successfully cloned, and soluble proteins were produced in Escherichia coli. SeeI, SeeL, and SeeM induced a dose-dependent proliferative response in equine CD4 T lymphocytes and synthesis of gamma interferon (IFN-?). SeeH did not stimulate equine peripheral blood mononuclear cells (PBMC) but induced proliferation of asinine PBMC. Allelic replacement mutants of S. equi strain 4047 with sequential deletion of the superantigen genes were generated. Deletion of seeI, seeL, and seeM completely abrogated the mitogenic activity and synthesis of IFN-?, in equine PBMC, of the strain 4047 culture supernatant. Sera from naturally infected convalescent horses had only limited sAg-neutralizing activities. We propose that S. equi sAgs play an important role in S. equi pathogenicity by stimulating an overzealous and inappropriate Th1 response that may interfere with the development of an effective immune response. PMID:20123710

Paillot, Romain; Robinson, Carl; Steward, Karen; Wright, Nicola; Jourdan, Thibaud; Butcher, Nicola; Heather, Zoe; Waller, Andrew S.

2010-01-01

288

Contribution of each of four Superantigens to Streptococcus equi-induced mitogenicity, gamma interferon synthesis, and immunity.  

PubMed

Streptococcus equi is the causative agent of strangles, the most frequently diagnosed infectious disease of horses worldwide. The disease is characterized by abscessation and swelling of the lymph nodes of the head and neck, which can literally strangle the horse to death. S. equi produces four recently acquired phage-associated bacterial superantigens (sAgs; SeeH, SeeI, SeeL, and SeeM) that share homology with the mitogenic toxins of Streptococcus pyogenes. The aim of this study was to characterize the contribution of each of these S. equi sAgs to mitogenic activity in vitro and quantify the sAg-neutralizing capacity of sera from naturally infected horses in order to better understand their role in pathogenicity. Each of the sAgs was successfully cloned, and soluble proteins were produced in Escherichia coli. SeeI, SeeL, and SeeM induced a dose-dependent proliferative response in equine CD4 T lymphocytes and synthesis of gamma interferon (IFN-gamma). SeeH did not stimulate equine peripheral blood mononuclear cells (PBMC) but induced proliferation of asinine PBMC. Allelic replacement mutants of S. equi strain 4047 with sequential deletion of the superantigen genes were generated. Deletion of seeI, seeL, and seeM completely abrogated the mitogenic activity and synthesis of IFN-gamma, in equine PBMC, of the strain 4047 culture supernatant. Sera from naturally infected convalescent horses had only limited sAg-neutralizing activities. We propose that S. equi sAgs play an important role in S. equi pathogenicity by stimulating an overzealous and inappropriate Th1 response that may interfere with the development of an effective immune response. PMID:20123710

Paillot, Romain; Robinson, Carl; Steward, Karen; Wright, Nicola; Jourdan, Thibaud; Butcher, Nicola; Heather, Zoe; Waller, Andrew S

2010-04-01

289

Hematogenous pyogenic vertebral osteomyelitis: diagnostic value of radionuclide bone imaging  

SciTech Connect

Hematogenous pyogenic vertebral osteomyelitis (HPVO) continues to be a diagnostic problem for clinicians due to nonspecific presentation of the disease (1,2). We reviewed our experience of the last 10 years to determine the diagnostic usefulness of radionuclide bone studies in this disease. We found 15 patients whose primary diagnosis was HPVO. Of the 15 patients, 12 had (99mTc)MDP bone scans which were all positive. Five of the 12 patients had positive (/sup 67/Ga)citrate scans and one patient with chronic active HPVO had negative /sup 67/Ga and (/sup 111/In)WBC bone images. At the same time, three patients' spine x-rays and one patient's CT scan of the vertebra were normal. Additionally, in three patients spine x-rays were interpreted as consistent with degenerative joint disease that contributed to the delay of the diagnosis. We conclude that when HPVO is suspected an abnormal (99mTc)MDP bone image increases the probability of the disease, even if the x-rays and CT scans of the spine are normal. An abnormal /sup 67/Ga image following an abnormal 99mTc bone image increases the specificity of the diagnosis. Normal (99mTc)MDP and (/sup 67/Ga)citrate bone images of the vertebra virtually exclude the diagnosis of HPVO.

Adatepe, M.H.; Powell, O.M.; Isaacs, G.H.; Nichols, K.; Cefola, R.

1986-11-01

290

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

291

Brain-abscess caused by Streptococcus bovis  

Microsoft Academic Search

Sir, Streptococcusbovis is found in the faeces of10-16 % of healthy persons and animals (i). This causative agent has long been known to be associated with endocarditis (2). It is a frequent cause of bacteremia and gastrointestinal diseases, principally neoplasias of the colon (1). We report a case of brain abscess associated with endocarditis caused by Streptococcus bovis. A 69

M. Montejo Baranda; K. Aguirrebengoa; M. Testillano; C. Aguirre

1985-01-01

292

Association of Streptococcus equi with equine monocytes  

Microsoft Academic Search

Streptococcus equi (Se), the cause of equine strangles, is highly resistant to phagocytosis by neutrophils and is usually classified as an extracellular pathogen. Large numbers of the organism in tonsillar tissues during the acute phase of the disease are completely eliminated during convalescence by mechanisms not yet understood. In this study we demonstrate in an opsono-bactericidal assay and by cytometry

Catherine Mérant; Abhineet Sheoran; John F. Timoney

2011-01-01

293

Identification of Lipoprotein Homologues of Pneumococcal PsaA in the Equine Pathogens Streptococcus equi and Streptococcus zooepidemicus  

PubMed Central

Streptococcus equi and Streptococcus zooepidemicus are major etiological agents of upper and lower airway disease in horses. Despite the considerable animal suffering and economic burden associated with these diseases, the factors that contribute to the virulence of these equine pathogens have not been extensively investigated. Here we demonstrate the presence of a homologue of the Streptococcus pneumoniae PsaA protein in both of these equine pathogens. Inhibition of signal peptide processing by the antibiotic globomycin confirmed the lipoprotein nature of the mature proteins, and surface exposure was confirmed by their release from intact cells by mild trypsinolysis. PMID:10992520

Harrington, Dean J.; Greated, Joanne S.; Chanter, Neil; Sutcliffe, Iain C.

2000-01-01

294

SpyAD, a moonlighting protein of group A Streptococcus contributing to bacterial division and host cell adhesion.  

PubMed

Group A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of the spy0269 gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interact in vitro with the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cells in vitro and that Lactococcus lactis expressing Spy0269 on its cell surface could adhere to mammalian cells in vitro and to mice nasal mucosa in vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (Streptococcus pyogenes Adhesion and Division protein). PMID:24778116

Gallotta, Marilena; Gancitano, Giovanni; Pietrocola, Giampiero; Mora, Marirosa; Pezzicoli, Alfredo; Tuscano, Giovanna; Chiarot, Emiliano; Nardi-Dei, Vincenzo; Taddei, Anna Rita; Rindi, Simonetta; Speziale, Pietro; Soriani, Marco; Grandi, Guido; Margarit, Immaculada; Bensi, Giuliano

2014-07-01

295

SpyAD, a Moonlighting Protein of Group A Streptococcus Contributing to Bacterial Division and Host Cell Adhesion  

PubMed Central

Group A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of the spy0269 gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interact in vitro with the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cells in vitro and that Lactococcus lactis expressing Spy0269 on its cell surface could adhere to mammalian cells in vitro and to mice nasal mucosa in vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (Streptococcus pyogenes Adhesion and Division protein). PMID:24778116

Gallotta, Marilena; Gancitano, Giovanni; Pietrocola, Giampiero; Mora, Marirosa; Pezzicoli, Alfredo; Tuscano, Giovanna; Chiarot, Emiliano; Nardi-Dei, Vincenzo; Taddei, Anna Rita; Rindi, Simonetta; Speziale, Pietro; Soriani, Marco; Bensi, Giuliano

2014-01-01

296

Identification of potential universal vaccine candidates against group A Streptococcus by using high throughput in silico and proteomics approach.  

PubMed

Streptococcus pyogenes or group A Streptococcus (GAS) causes ~700 million human infections each year, resulting in over 500,000 deaths. The development of a commercial GAS vaccine is hampered due to high strain and serotype diversity in different geographical regions, and the generation of cross-reactive antibodies that may induce autoimmune disease. There is an urgent need to search for alternative vaccine candidates. High throughput multigenome data mining coupled with proteomics seems to be a promising approach to identify the universal vaccine candidates. In the present study, in silico analysis led to prediction of 147 proteins as universal vaccine candidates. Distribution pattern of these predicted candidates was explored in nonsequenced Indian GAS strains (n = 20) by using DNA array hybridization validating in silico analysis. High throughput analyses of surface proteins using 1D-SDS-PAGE coupled with ESI-LC-MS/MS was applied on highly (M49) and less (M1) invasive GAS strains of Indian origin. Comparative proteomics analysis revealed that highly invasive GAS M49 had metabolically more active membrane associated protein machinery than less invasive M1. Further, by overlapping proteomics data with in silico predicted vaccine candidate genes, 52 proteins were identified as probable universal vaccine candidates, which were expressed in these GAS serotypes. These proteins can further be investigated as universal vaccine candidates against GAS. Moreover, this robust approach may serve as a model that can be applied to identify the universal vaccine candidates in case of other pathogenic bacteria with high strain and genetic diversity. PMID:23181284

Sharma, Abhinay; Arya, Deepak Kumar; Sagar, Vivek; Bergmann, René; Chhatwal, Gursharan Singh; Johri, Atul Kumar

2013-01-01

297

Recent advances in understanding the molecular basis of group B Streptococcus virulence  

PubMed Central

Group B Streptococcus commonly colonises healthy adults without symptoms, yet under certain circumstances displays the ability to invade host tissues, evade immune detection and cause serious invasive disease. Consequently, Group B Streptococcus remains a leading cause of neonatal pneumonia, sepsis and meningitis. Here we review recent information on the bacterial factors and mechanisms that direct host–pathogen interactions involved in the pathogenesis of Group B Streptococcus infection. New research on host signalling and inflammatory responses to Group B Streptococcus infection is summarised. An understanding of the complex interplay between Group B Streptococcus and host provides valuable insight into pathogen evolution and highlights molecular targets for therapeutic intervention. PMID:18803886

Maisey, Heather C.; Doran, Kelly S.; Nizet, Victor

2009-01-01

298

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

299

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

300

Group B streptococcus - pregnancy  

MedlinePLUS

Group B streptococcus (GBS) is a type of bacteria that some women carry in their intestines and vagina. It is not ... to infections in: The blood (sepsis) The lungs (pneumonia) The brain (meningitis) Most babies who get GBS ...

301

Identification of a novel streptococcal gene cassette mediating SOS mutagenesis in Streptococcus uberis.  

PubMed

Streptococci have been considered to lack the classical SOS response, defined by increased mutation after UV exposure and regulation by LexA. Here we report the identification of a potential self-regulated SOS mutagenesis gene cassette in the Streptococcaceae family. Exposure to UV light was found to increase mutations to antibiotic resistance in Streptococcus uberis cultures. The mutational spectra revealed mainly G:C-->A:T transitions, and Northern analyses demonstrated increased expression of a Y-family DNA polymerase resembling UmuC under DNA-damaging conditions. In the absence of the Y-family polymerase, S. uberis cells were sensitive to UV light and to mitomycin C. Furthermore, the UV-induced mutagenesis was almost completely abolished in cells deficient in the Y-family polymerase. The gene encoding the Y-family polymerase was localized in a four-gene operon including two hypothetical genes and a gene encoding a HdiR homolog. Electrophoretic mobility shift assays demonstrated that S. uberis HdiR binds specifically to an inverted repeat sequence in the promoter region of the four-gene operon. Database searches revealed conservation of the gene cassette in several Streptococcus species, including at least one genome each of Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus mitis, Streptococcus sanguinis, and Streptococcus thermophilus strains. In addition, the umuC operon was localized in several mobile DNA elements of Streptococcus and Lactococcus species. We conclude that the hdiR-umuC-ORF3-ORF4 operon represents a novel gene cassette capable of mediating SOS mutagenesis among members of the Streptococcaceae. PMID:17513475

Varhimo, Emilia; Savijoki, Kirsi; Jalava, Jari; Kuipers, Oscar P; Varmanen, Pekka

2007-07-01

302

Insight into the Evolution of the Histidine Triad Protein (HTP) Family in Streptococcus  

PubMed Central

The Histidine Triad Proteins (HTPs), also known as Pht proteins in Streptococcus pneumoniae, constitute a family of surface-exposed proteins that exist in many pathogenic streptococcal species. Although many studies have revealed the importance of HTPs in streptococcal physiology and pathogenicity, little is known about their origin and evolution. In this study, after identifying all htp homologs from 105 streptococcal genomes representing 38 different species/subspecies, we analyzed their domain structures, positions in genome, and most importantly, their evolutionary histories. By further projecting this information onto the streptococcal phylogeny, we made several major findings. First, htp genes originated earlier than the Streptococcus genus and gene-loss events have occurred among three streptococcal groups, resulting in the absence of the htp gene in the Bovis, Mutans and Salivarius groups. Second, the copy number of htp genes in other groups of Streptococcus is variable, ranging from one to four functional copies. Third, both phylogenetic evidence and domain structure analyses support the division of two htp subfamilies, designated as htp I and htp II. Although present mainly in the pyogenic group and in Streptococcus suis, htp II members are distinct from htp I due to the presence of an additional leucine-rich-repeat domain at the C-terminus. Finally, htp genes exhibit a faster nucleotide substitution rate than do housekeeping genes. Specifically, the regions outside the HTP domains are under strong positive selection. This distinct evolutionary pattern likely helped Streptococcus to easily escape from recognition by host immunity. PMID:23527301

Pan, Xiu-Zhen; Wang, Bin; Chen, Jian-Qun

2013-01-01

303

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

304

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

305

Fatal multivalvular endocarditis due to Streptococcus milleri and Streptococcus sanguis  

Microsoft Academic Search

Sir, Streptococcus milleri is an unusual cause of infective endocarditis that has been associated with high rates of suppurative complications (1). We report here on a patient with multivalvular, polymicrobial endocarditis due to Streptococcus milleri and Streptococcus sanguis who died despite prompt antibiotic therapy and early surgery. The previously healthy 44 year old male presented with a ten day history

R. M. Tucker; W. M. Scheid; R. M. Mentzer; R. S. Gibson

1987-01-01

306

Isolation of gram-positive rods that resemble but are clearly distinct from Actinomyces pyogenes from mixed wound infections.  

PubMed Central

Beginning in 1990, gram-positive rods resembling Actinomyces pyogenes were found with increasing frequency in mixed cultures from various infectious processes, most of them from patients with otitis, empyema, pilonidal cysts, perianal abscesses, and decubitus ulcers. Ribotyping and hybridization showed that these gram-positive rods could be divided into five groups not related to known Actinomyces species. Biochemical markers for reliable differentiation into these groups, however, could not be found. Therefore, naming new species is not warranted unless parameters are discovered that allow identification without DNA hybridization. These gram-positive rods have been isolated only in mixed cultures with anaerobes, Staphylococcus aureus, Streptococcus "milleri," enterococci, and gram-negative rods. Their exact role in these possibly synergistic infections needs further investigation. Images PMID:8501213

Wüst, J; Lucchini, G M; Lüthy-Hottenstein, J; Brun, F; Altwegg, M

1993-01-01

307

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

308

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 ...

309

Streptococcus salivariusUrease: Genetic and Biochemical Characterization and Expression in a Dental Plaque Streptococcus  

Microsoft Academic Search

The hydrolysis of urea by urease enzymes of oral bacteria is believed to have a major impact on oral microbial ecology and to be intimately involved in oral health and diseases. To begin to understand the biochemistry and genetics of oral ureolysis, a study of the urease ofStreptococcus salivarius, a highly ureolytic organism which is present in large numbers on

YI-YWAN M. CHEN; K. ANNE CLANCY; ANDROBERT A. BURNE

1996-01-01

310

Streptococcus equi but not Streptococcus zooepidemicus produces potent mitogenic responses from equine peripheral blood mononuclear cells  

Microsoft Academic Search

Streptococcus equi causes equine strangles. The acute disease has many of the hallmarks of an acute response including high fever, elevated plasma fibrinogen and neutrophilia, affects known to be mediated by proinflammatory cytokines. The objective of this study was to screen-culture supernatants from equine clinical isolates of S. equi and S. zooepidemicus for stimulation of mitogenic responses by horse peripheral

T Anzai; A. S Sheoran; Y Kuwamoto; T Kondo; R Wada; T Inoue; J. F Timoney

1999-01-01

311

Genetic Relationships between Clinical Isolates of Streptococcus pneumoniae, Streptococcus oralis, and Streptococcus mitis: Characterization of \\  

Microsoft Academic Search

The oral streptococcal group (mitis phylogenetic group) currently consists of nine recognized species, although the group has been traditionally difficult to classify, with frequent changes in nomenclature over the years. The pneumococcus (Streptococcus pneumoniae), an important human pathogen, is traditionally distin- guished from the most closely related oral streptococcal species Streptococcus mitis and Streptococcus oralis on the basis of three

ADRIAN M. WHATMORE; ANDROULLA EFSTRATIOU; A. PAUL PICKERILL; KAREN BROUGHTON; GEOFFREY WOODARD; DANIEL STURGEON; ROBERT GEORGE; CHRISTOPHER G. DOWSON

2000-01-01

312

Real-time PCR for detection and differentiation of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus  

Microsoft Academic Search

Strangles is a contagious equine disease caused by Streptococcus equi subsp. equi. In this study, clinical strains of S. equi (n=24) and Streptococcus equi subsp. zooepidemicus (n=24) were genetically characterized by sequencing of the 16S rRNA and sodA genes in order to devise a real-time PCR system that can detect S. equi and S. zooepidemicus and distinguish between them.Sequencing demonstrated

V. Båverud; S. K. Johansson; A. Aspan

2007-01-01

313

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

314

Immune complex binding Streptococcus pyogenes type M12/emm12 in experimental glomerulonephritis.  

PubMed

In a rabbit model, we have previously reported evidence for a pathogenic role of streptococcal IgG Fc-binding proteins (IgGFcBP) in poststreptococcal glomerulonephritis (PSGN). These proteins, of the M protein family, were shown to trigger anti-IgG production and enhance renal deposition of IgG and/or immune complexes (ICs), with resulting activation of complement and cytokine cascades. In the present study, type M12/emm12, group A streptococci (GAS) were found often to bind artificial ICs, viz. peroxidase-anti-peroxidase rabbit IgG (PAP) or tetanus toxoid-anti-tetanus human IgG (TAT), rather than monomeric IgG. Animals injected with each of four IC binding clinical isolates (from patients with scarlet fever or PSGN) showed pronounced inflammatory and degenerative glomerular changes, morphologically similar to human PSGN, with membrane thickening and IgG and complement C3 deposition, as well as secretion of IL-6 and TNF-? by mesangial and endothelial cells. In contrast, non-binding strains (two from asymptomatic carriers and one from a PSGN case) failed to trigger any renal changes. Only the IC binding strains induced elevated titres of anti-IgG. Though the streptococcal binding component(s) has not been demonstrated, the selective binding of ICs by type M12/emm12 strains appears important for the well-known, marked nephritogenic potential of this GAS type. PMID:23788594

Burova, Larissa; Pigarevsky, Peter; Duplik, Nadezhda; Snegova, Vlada; Suvorov, Alexander; Schalen, Claes; Totolian, Artem

2013-09-01

315

Draft Genome Sequences of Three Strains of Bacteroides pyogenes Isolated from a Cat and Swine  

PubMed Central

Here, we report the draft genome sequences of Bacteroides pyogenes JCM 6294T, JCM 6292, and JCM 10003, which were isolated from a cat and swine and were recently classified into a single species, B. pyogenes. Comparative analyses of these genomes revealed the diversification of B. pyogenes strains isolated from different animals. PMID:24482517

Oshima, Kenshiro; Suda, Wataru; Kitamura, Keiko; Iida, Toshiya; Hattori, Masahira; Ohkuma, Moriya

2014-01-01

316

Streptococcus iniae vaccine  

Technology Transfer Automated Retrieval System (TEKTRAN)

Streptococcus iniae is among the most important emergent pathogens that affects many fish species worldwide, especially in warm-water regions. In marine and freshwater systems, this Gram-positive bacterium causes significant economic losses, estimated at hundreds of millions of dollars annually. Inf...

317

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

318

Characterization and immunogenicity of pyrogenic mitogens SePE-H and SePE-I of Streptococcus equi.  

PubMed

Two pyrogenic mitogens, SePE-H and SePE-I, were characterized in Streptococcus equi, the cause of equine strangles. SePE-H and SePE-I have molecular masses of 27.5 and 29.5 kDa, respectively, and each is almost identical to its counterpart in Streptococcus pyogenes M1. Both genes are adjacent to a gene encoding a phage muramidase of 49.7 kDa and are located immediately downstream from a phage genomic sequence almost identical to a similar phage sequence in S. pyogenes M1. Strong mitogenic responses were elicited by both proteins from horse peripheral blood mononuclear cells. However, although both were pyrogenic for rabbits, only SePE-I was pyrogenic in ponies. Convalescent sera contained antibody to each mitogen and horses recovered from strangles or immunized with SePE-I were resistant to the pyrogenic effect of SePE-I. The immunogenicity of SePE-I suggests that it should be included in new generation strangles vaccines. In isolates of S. equi sepe-I and sepe-H were consistently present but they were absent from the closely related Streptococcus zooepidemicus, suggesting that phage mediated transfer was an important event in the formation of the clonal, more virulent, S. equi from its putative S. zooepidemicus ancestor. PMID:11812213

Artiushin, S C; Timoney, J F; Sheoran, A S; Muthupalani, S K

2002-02-01

319

Multiple periungual pyogenic granulomas following systemic 5-fluorouracil.  

PubMed

A 65-year-old man presented with a 7-month history of eight bleeding periungual lesions on both feet. The clinical diagnosis of multiple pyogenic granulomas was confirmed by histological examination. Historically, the pyogenic granulomas appeared 3 months after commencing 5-fluorouracil chemotherapy for rectal carcinoma, suggesting a possible causative relationship. Chemotherapy was ceased by the supervising oncologist. Resolution occurred after two lesions had been treated with curettage and diathermy, and the remaining lesions with occlusive dressings over Kenacomb ointment (triamcinolone acetonide 0.1%, neomycin sulphate 0.25%, gramicidin 0.025%, nystatin 100,000 U/g) topically twice daily for a period of 3 months. PMID:16637811

Curr, Nathan; Saunders, Helen; Murugasu, Anand; Cooray, Prasad; Schwarz, Max; Gin, Douglas

2006-05-01

320

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

PubMed Central

Two novel streptococcal superantigen genes (speLSe and speMSe) were identified from the Streptococcus equi genome database at the Sanger Center. Genotyping of 8 S. equi isolates and 40 Streptococcus pyogenes isolates resulted in the detection of the orthologous genes speL and speM in a restricted number of S. pyogenes isolates (15 and 5%, respectively). Surprisingly, the novel superantigen genes could not be found in any of the analyzed S. equi isolates. The results suggest that both genes are located on a mobile element that enables gene transfer between individual isolates and between streptococci from different Lancefield groups. S. equi pyrogenic exotoxin L (SPE-LSe)/streptococcal pyrogenic exotoxin L (SPE-L) and SPE-MSe/SPE-M are most closely related to SMEZ, SPE-C, SPE-G, and SPE-J, but build a separate branch within this group. Recombinant SPE-L (rSPE-L) and rSPE-M were highly mitogenic for human peripheral blood lymphocytes, with half-maximum responses at 1 and 10 pg/ml, respectively. The results from competitive binding experiments suggest that both proteins bind major histocompatibility complex class II at the ?-chain, but not at the ?-chain. The most common targets for both toxins were human V?1.1 expressing T cells. Seroconversion against SPE-L and SPE-M was observed in healthy blood donors, suggesting that the toxins are expressed in vivo. Interestingly, the speL gene is highly associated with S. pyogenes M89, a serotype that is linked to acute rheumatic fever in New Zealand. PMID:12595453

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

2003-01-01

321

Internal jugular vein pyogenic capillary hemangioma: a case report.  

PubMed

Internal jugular vein hemangioma, also called pyogenic granuloma, is a rare tumor. Such a neoformation was accidentally discovered and excised in a middle-aged man. Histologic and immunohistochemical investigations were performed, and this case is compared with the poor amount of similar ones described in the literature. PMID:25462549

Cera, Chiara; Calvagna, Cristiano; Sgorlon, Giada; Zamolo, Francesca; Pancrazio, Francesco; Adovasio, Roberto

2015-02-01

322

Post-partum pyogenic abscess containing Ascaris lumbricoides  

PubMed Central

We report an unusual case of multiple pyogenic liver abscesses containing Ascariasis lumbricoides in a 35-year-old post-partum female who had delivered 1 month back. Open drainage of liver abscess along with liver worm was done. Patient did well post-operatively. PMID:23961448

Hamid, Raashid; Wani, Sajad; Ahmad, Nawab; Akhter, Afrozah

2013-01-01

323

[A case of prostate abscess with sepsis, infectious endocarditis and pyogenic spondylitis].  

PubMed

A 65-year-old man with diabetes mellitus (DM) presented with an indwelling urethral catheter placed for urinary retention by his previous doctor. Thereafter, he had fever, vomiting and general fatigue. His blood examination showed severe inflammatory findings. He was diagnosed with acute prostatitis and immediately admitted to our hospital. Pelvic computerized tomography (CT) showed a prostate abscess. We performed transrectal ultrasonographic-guided puncture of the prostate abscess for drainage and blood culture was tested. Methicillin-sensitive Staphylococcus aureus (MSSA) was cultured from the puncture fluid and blood. We administered antibiotics with strict control of DM. After the prostate abscess improved and the urethral catheter was removed, the patient was systematically examined for potential sepsis-related disease caused by MSSA septic infection. Magnetic resonance imaging (MRI) of the head indicated multiple cerebral infarction, abdominal CT indicated splenetic infarction, ultrasonography of the heart indicated vegetation on the mitral valve and aortic valve, and chest X-ray indicated pulmonary congestion. Furthermore, MRI of the lumbar spine showed a high intensity lesion at the 4th and 5th lumbar spine, indicating pyogenic spondylitis. We diagnosed prostate abscess with sepsis, infectious endocarditis, congestive heart failure and pyogenic spondylitis. Aortic valve replacement, mitral annuloplasty, tricuspid valvuloplasty and ovale hole closure surgeries were performed to treat these conditions. PMID:23235281

Matsumoto, Minori; Shigemura, Katsumi; Yamamichi, Fukashi; Nakano, Yuzo; Miyake, Hideaki; Tanaka, Kazushi; Arakawa, Soichi; Fujisawa, Masato

2012-10-01

324

Pyogenic liver abscess caused by Fusobacterium in a 21-year-old immunocompetent male  

PubMed Central

A 21-year-old male with no significant past medical history, presented with right upper quadrant (RUQ) abdominal pain along with fevers and chills. Lab work revealed leukocytosis, anemia, and slightly elevated alkaline phosphatase. Viral serology for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus were negative and he was immunocompetent. Computed tomography imaging revealed hepatic abscesses, the largest measuring 9.5 cm. Empiric antibiotics were started and percutaneous drains were placed in the abscesses. Anaerobic cultures from the abscesses grew Fusobacterium nucleatum. This is a gram negative anaerobic bacteria; a normal flora of the oral cavity. Fusobacterium is most commonly seen in Lemiere’s disease, which is translocation of oral bacteria to the internal jugular vein causing a thrombophlebitis and subsequent spread of abscesses. Our patient did not have Lemiere’s, and is the first case described of fusobacterium pyogenic liver abscess in a young immunocompetent male with good oral hygiene. This case was complicated by sepsis, empyema, and subsequent abscesses located outside the liver. These abscesses’ have the propensity to flare abruptly and can be fatal. This case not only illustrates fusobacterium as a rare entity for pyogenic liver abscess, but also the need for urgent diagnosis and treatment. It is incumbent on physicians to diagnose and drain any suspicious hepatic lesions. While uncommon, such infections may develop without any overt source and can progress rapidly. Prompt drainage with antibiotic therapy remains the cornerstone of therapy.

Ahmed, Zohair; Bansal, Saurabh K; Dhillon, Sonu

2015-01-01

325

Group a streptococcal diseases and their global burden.  

PubMed

Group A streptococcus (GAS) or Streptococcus pyogenes has been recognised as an important human pathogen since early days of modern microbiology, and it remains among the top ten causes of mortality from an infectious disease. Clinical manifestations attributable to this organism are perhaps the most diverse of any single human pathogen. These encompass invasive GAS infections, with high mortality rates despite effective antimicrobials, toxin-mediated diseases including scarlet fever and streptococcal toxic shock syndrome, the autoimmune sequelae of rheumatic fever and glomerulonephritis with potential for long-term disability, and nuisance manifestations of superficial skin and pharyngeal infection, which continue to consume a sizable proportion of healthcare resources. Although an historical perspective indicates major overall reductions in GAS infection rates in the modern era, chiefly as a result of widespread improvements in socioeconomic circumstances, this pathogen remains as a leading infectious cause of global morbidity and mortality. More than 18 million people globally are estimated to suffer from serious GAS disease. This burden disproportionally affects least affluent populations, and is a major cause of illness and death among children and young adults, including pregnant women, in low-resource settings. We review GAS transmission characteristics and prevention strategies, historical and geographical trends and report on the estimated global burden disease attributable to GAS. The lack of systematic reporting makes accurate estimation of rates difficult. This highlights the need to support improved surveillance and epidemiological research in low-resource settings, in order to enable better assessment of national and global disease burdens, target control strategies appropriately and assess the success of control interventions. PMID:23242849

Ralph, Anna P; Carapetis, Jonathan R

2013-01-01

326

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

327

[Properties of metabolic substance produced by group A Streptococcus from two food-borne epidemic].  

PubMed

We report the finding for two food-poisonins outbreaks occurring in Tokyo and Chiba in September 2003. Patients in the Tokyo outbreak suffered from fever varying widely from 35.9 degrees C to 39.4 degrees C. Throat pain was predominant, accompanied by headache, cough, and joint pain. Patients in the Chiba outbreak suffered from malaise in addition to the above symptoms. To clarify the relationship between pathology and virulence factors, we studied the properties of hemolysins and proteases produced by the causative bacteria, Streptococcus pyogenes, specifically type T-28 in the Tokyo outbreak and type T-B3264 in the Chiba outbreak. The main S. pyogenes T serotypes isolated in 2003 were types T12, T1, T4, and T3, followed types T-28 and T-B3264. The hemolytic titer of hemolysins, which are metabolic, was 173HD50/mL for T-28 and 147HD50/mL for T-B3264. Hemolysins produced by both strains did not depend on reducing agents and were not inhibited by gamma-globulin or cholesterol, indicating the streptolysin S (SLS) rather than hemolysis inhibition by phospholipids. The fact that the titer increased slightly in the presence of reducing agents indicates that some amount of streptolysin O may also have been present. Protease production was four times greater for T-B3264 than for T-28. Proteases produced by both strains were similarly inhibited by sodium tetrathionate, iodoacetate, and normal serum. The outbreak infection was caused by infiltration of food-borne Streptococcus bacteria via the upper airway during eating. The primary cause of predominant throat pain was thought to be SLS cytotoxicity in the upper respiratory mucous membrane. This toxin was also thought to assist in Streptococcus bacteria infiltration and proliferation. Proteases produced by pathogenic bacteria were thought to have acted on the body as potent virulence factors. PMID:19697874

Suzuki, Jun; Sakaguchi, Kazuko

2009-07-01

328

Interim UK guidelines for management of close community contacts of invasive group A streptococcal disease Health Protection Agency, Group A Streptococcus Working Group  

Microsoft Academic Search

Summary: Group A streptococci cause a wide range of illnesses from non-invasive disease such as pharyngitis to more severe invasive infections such as necrotising fasciitis. There remains uncertainty about the risk of invasive disease among close contacts of an index case of invasive disease and whether this risk warrants antibiotic prophylaxis. A 19-200 fold increased risk among household contacts has

James M Stuart; Stonehouse GL

329

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

330

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

331

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

332

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

333

Distribution of streptococcal inhibitor of complement variants in pharyngitis and invasive isolates in an epidemic of serotype M1 group A Streptococcus infection.  

PubMed

Streptococcal inhibitor of complement (Sic) is a highly polymorphic extracellular protein made predominantly by serotype M1 group A Streptococcus (GAS). New variants of the Sic protein frequently appear in M1 epidemics as a result of positive natural selection. To gain further understanding of the molecular basis of M1 epidemics, the sic gene was sequenced from 471 pharyngitis and 127 pyogenic and blood isolates recovered from 598 patients living in metropolitan Helsinki, Finland, during a 37-month population-based surveillance study. Most M1 GAS subclones recovered from pyogenic infections and blood were abundantly represented in the pool of subclones causing pharyngitis. Alleles shared among the pharyngitis, pyogenic, and blood samples were identified in throat isolates a mean of 9.8 months before their recovery from pyogenic infections and blood, which indicates that selection of most sic variants occurs on mucosal surfaces. In contrast, no variation was identified in the emm and covR/covS genes. PMID:11170990

Hoe, N P; Vuopio-Varkila, J; Vaara, M; Grigsby, D; De Lorenzo, D; Fu, Y X; Dou, S J; Pan, X; Nakashima, K; Musser, J M

2001-02-15

334

GENOMIC DIVERSITY OF STREPTOCOCCUS AGALACTIAE FROM FISH, BOVINE AND HUMAN HOSTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Group B Streptococcus agalactiae (GBS) is a cause of infectious disease in multiple poikilothermic and homothermic animal species. Epidemiological and zoonotic considerations necessitate an undertaking of a comparison of S. agalactiae isolates from different phylogenetic hosts and geographical regi...

335

Putative lipoproteins of Streptococcus agalactiae identified by bioinformatic genome analysis  

Microsoft Academic Search

Streptococcus agalactiae is a significant pathogen causing invasive disease in neonates and thus an understanding of the molecular basis of the pathogenicity of this organism is of importance. N-terminal lipidation is a major mechanism by which bacteria can tether proteins to membranes. Lipidation is directed by the presence of a cysteine-containing ‘lipobox’ within specific signal peptides and this feature has

Iain C. Sutcliffe; Dean J. Harrington

2004-01-01

336

Group B Streptococcus: global incidence and vaccine development  

Microsoft Academic Search

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

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

2006-01-01

337

Citrobacter koseri: an unusual cause of pyogenic liver abscess  

PubMed Central

Liver abscess is a common pathology in the Indian subcontinent and usually results from amoebic or bacterial infection. Pyogenic abscesses usually occur in those with underlying predisposing factors like intra-abdominal infections, biliary infections or comorbidities like malignancy, immunosuppression, diabetes mellitus and previous biliary surgery or interventional endoscopy. Citrobacter is an unusual cause of pyogenic liver abscess and may occur in the setting of underlying comorbidities. We report a 56-year-old man with diabetes (operated for periampullary carcinoma 20?years ago), who presented with a history of fever for 1?week and on evaluation was found to have Citrobacter koseri-related hepatic abscess. The patient was managed with parenteral antibiotics, repeated aspiration of liver abscess and pigtail drainage. PMID:23505286

Gupta, Monica; Sharma, Alka; Singh, Ram; Lehl, S S

2013-01-01

338

Association of Streptococcus equi with equine monocytes.  

PubMed

Streptococcus equi (Se), the cause of equine strangles, is highly resistant to phagocytosis by neutrophils and is usually classified as an extracellular pathogen. Large numbers of the organism in tonsillar tissues during the acute phase of the disease are completely eliminated during convalescence by mechanisms not yet understood. In this study we demonstrate in an opsono-bactericidal assay and by cytometry and confocal microscopy that Se is interiorized and killed by equine blood monocytes. This finding supports the hypotheses that adaptive immune clearance is mediated by tonsillar macrophages and that macrophages monocytes could serve as a vehicle for transport from the tonsil to local lymph nodes. PMID:21752476

Mérant, Catherine; Sheoran, Abhineet; Timoney, John F

2011-09-15

339

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

2015-04-01

340

[Maternal and perinatal infections to Streptococcus agalactiae].  

PubMed

Streptococcus agalactiae (Group B Streptococcus, GBS) is a Gram-positive encapsulated bacterium, found in the digestive and vaginal tracts of 20-30% healthy individuals. It is the leading cause of neonatal invasive infections (septicaemia and meningitis). Two GBS-associated syndromes have been recognized in neonates, the early-onset disease (EOD) and the late-onset disease (LOD), which occur in the first week of life (age 0-6 days) and after (age 7 days-3 months), respectively. Since the establishment of early antibiotic prophylaxis there has been a decrease in the incidence of EOD. However, LOD incidence remains stable. Epidemiological studies revealed a strong association between LOD and a single capsular serotype III ST-17 clone. This ST-17 clone, referred to as the "hypervirulent" clone, possesses specific virulence factors that could account for its increased virulence and neonatal tropism. Conjugate vaccines directed against several capsular serotypes are being developed to prevent invasive disease. However, hypervirulent strains having made a switch to a capsular serotype not covered by such vaccines are emerging, reinforcing the need to identify new candidate vaccines. PMID:24855049

Six, Anne; Joubrel, Caroline; Tazi, Asmaa; Poyart, Claire

2014-06-01

341

Pneumococcal Disease: Types of Infection  

MedlinePLUS

... Vaccination World Health Organization National Foundation for Infectious Diseases Types of Infection Recommend on Facebook Tweet Share Compartir Streptococcus pneumoniae bacteria, or pneumococcus, can cause many types ...

342

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

343

Fatal case of toxic shock-like syndrome due to group C streptococcus associated with superantigen exotoxin.  

PubMed

Group C streptococci have been reported to cause invasive disease similar to that classically associated with group A streptococcus (GAS). We describe a fatal case of toxic shock-like syndrome due to Streptococcus equi subsp. zooepidemicus. The causative organism did not possess any known GAS superantigen exotoxin genes but did show evidence of superantigen production. PMID:15184494

Korman, Tony M; Boers, Anthony; Gooding, Travis M; Curtis, Nigel; Visvanathan, Kumar

2004-06-01

344

Fatal Case of Toxic Shock-Like Syndrome Due to Group C Streptococcus Associated with Superantigen Exotoxin  

PubMed Central

Group C streptococci have been reported to cause invasive disease similar to that classically associated with group A streptococcus (GAS). We describe a fatal case of toxic shock-like syndrome due to Streptococcus equi subsp. zooepidemicus. The causative organism did not possess any known GAS superantigen exotoxin genes but did show evidence of superantigen production. PMID:15184494

Korman, Tony M.; Boers, Anthony; Gooding, Travis M.; Curtis, Nigel; Visvanathan, Kumar

2004-01-01

345

Fatal Case of Toxic Shock-Like Syndrome Due to Group C Streptococcus Associated with Superantigen Exotoxin  

Microsoft Academic Search

Group C streptococci have been reported to cause invasive disease similar to that classically associated with group A streptococcus (GAS). We describe a fatal case of toxic shock-like syndrome due to Streptococcus equi subsp. zooepidemicus. The causative organism did not possess any known GAS superantigen exotoxin genes but did show evidence of superantigen production.

Tony M. Korman; Anthony Boers; Travis M. Gooding; Nigel Curtis; Kumar Visvanathan

2004-01-01

346

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

347

Appendicitis in a Child due to Streptococcus Pneumoniae: A Rare Case Report  

PubMed Central

A variety of bacterial species play a major role in appendicitis. Both aerobic and anaerobic gram positive and gram negative bacteria such as, Bacteroides fragilis, Streptococcus species, Escherichia coli, Klebsiella species and Citrobacter freundii cause appendicitis. Appendicitis is usually polymicrobial. The case assumes importance because of single aetiological agent i.e. unimicrobial and no predisposing factors are present to cause infection. We report a rare case of appendicitis due to Streptococcus pneumoniae in child. This case emphasizes that Streptococcus pneumoniae can cause wide spectrum of disease like appendicitis. PMID:25737990

Kamble, Deepali Shivajirao; Nale, Swati Shivajirao; Bhore, Arvind Vamanrao

2015-01-01

348

Profusely bleeding oral pyogenic granuloma in a teenage girl  

PubMed Central

Pyogenic granuloma (PG) is a kind of inflammatory hyperplastic soft tissue lesion of the oral cavity. The lesion, however, is not related to infection and arise as a reactive growth in response to various stimuli. It has a very high vascularity because of the presence of numerous prominent capillaries. The lesion has a bleeding tendency, even after a minor traumatic episode, such as during mastication. Bleeding may be at times very severe and difficult to control. We present the case of a profusely bleeding young PG in a young teenage child. PMID:23486345

Singh, Rajeev Kumar; Kaushal, Ambrish; Kumar, Rakesh; Pandey, Ramesh Kumar

2013-01-01

349

Streptococcus agalactiae infection in zebrafish larvae.  

PubMed

Streptococcus agalactiae (Group B Streptococcus, GBS) is an encapsulated, Gram-positive bacterium that is a leading cause of neonatal pneumonia, sepsis and meningitis, and an emerging aquaculture pathogen. The zebrafish (Danio rerio) is a genetically tractable model vertebrate that has been used to analyze the pathogenesis of both aquatic and human bacterial pathogens. We have developed a larval zebrafish model of GBS infection to study bacterial and host factors that contribute to disease progression. GBS infection resulted in dose dependent larval death, and GBS serotype III, ST-17 strain was observed as the most virulent. Virulence was dependent on the presence of the GBS capsule, surface anchored lipoteichoic acid (LTA) and toxin production, as infection with GBS mutants lacking these factors resulted in little to no mortality. Additionally, interleukin-1? (il1b) and CXCL-8 (cxcl8a) were significantly induced following GBS infection compared to controls. We also visualized GBS outside the brain vasculature, suggesting GBS penetration into the brain during the course of infection. Our data demonstrate that zebrafish larvae are a valuable model organism to study GBS pathogenesis. PMID:25617657

Kim, Brandon J; Hancock, Bryan M; Del Cid, Natasha; Bermudez, Andres; Traver, David; Doran, Kelly S

2015-02-01

350

Posthaste Outgrow of Lip Pyogenic Granuloma after Diode Laser Removal  

PubMed Central

Introduction: Pyogenic granuloma (PG) is one of the inflammatory hyperplasia seen in the oral cavity. It is a reactional response to minor trauma or chronic irritation and also might be related to hormonal changes. Rarely, PG occurs extragingivally.The most common treatment of PG is surgical excision but alternative approaches such as laser excision have also been proposed. Case report: Herein, we present a case of lip pyogenic granuloma in a 15-year-old male whom had been under orthodontic treatment. The lesion was first excised with diode laser as a conservative method, but the lesion had immediately recurred and was excised with surgical blade as the traditional method. No recurrence or scarring was observed in 6 months follow-up. Results and conclusion: Although the use of laser as modern medicine offers a new tool for treatment of oral lesions, scalpel (blade) surgical excision still seems to be the successful treatment of choice in minimizing the recurrence of lesion especially when exacerbating factors such as hormonal imbalances exist. PMID:25653806

Asnaashari, Mohammad; Bigom-Taheri, Jamile; Mehdipoor, Maesoome; Bakhshi, Mahin

2014-01-01

351

Virulence determinants and biofilm production among Trueperella pyogenes recovered from abscesses of captive forest musk deer.  

PubMed

Trueperella pyogenes (formerly Arcanobacterium) is commonly isolated from domesticated or wild ruminants as an opportunistic pathogen. To investigate the role of virulence determinants (VDs) and biofilm production in T. pyogenes isolates, a total of 36 T. pyogenes were collected from abscesses of forest musk deer in Miyaluo Farm (Sichuan Province, China). The prevalence of VDs and associations with clonal types, antibiotic resistance and biofilm production were analyzed by PCR and bioassay. Finally, T. pyogenes isolates were separated into three clonal types based on the DNA fingerprinting of BOX-PCR. Isolates with less VDs obtained from sick forest musk deer were mainly belonged to Type 1, and the isolates with robust VD repertoire obtained from dead forest musk deer were included in Type 3. Accordingly, resistant isolates exhibited significant lower virulence than susceptible ones. Majority of T. pyogenes isolates of this study were capable of producing a biofilm. However, no VDs presence and antibiotic resistance were statistically associated with biofilm production. In conclusion, the current study demonstrated that T. pyogenes was probably the primary pathogen of abscesses in the forest musk deer. Moreover, as an animal origin pathogen, the increasing resistance of T. pyogenes isolates could also associate with a decreased virulence. PMID:23354327

Zhao, Kelei; Tian, Yongqiang; Yue, Bisong; Wang, Hongning; Zhang, Xiuyue

2013-03-01

352

Pyogenic granuloma occurring in a postmenopausal woman on hormone replacement therapy.  

PubMed

Pyogenic granuloma is a benign nodular lesion occurring most commonly on the gingiva of females during periods of elevated sex hormones such as puberty and pregnancy. Possible molecular mechanisms responsible for the appearance of pyogenic granuloma in this demographic have been suggested. Increased incidence of pyogenic granuloma in post menopausal women on hormone replacement therapy has not been reported. A 49-year-old woman with preexisting titanium implant placement in the left posterior mandible presented with complaint of food impaction and slight discomfort associated with the implant. Clinical examination revealed slight soft tissue erythema and edema, but no foreign body could be identified. Subsequently, a nodular gingival lesion associated with the implant developed and was treated by conservative surgical excision. Histologic characteristics of the lesion were consistent with pyogenic granuloma. The patient was informed of the diagnosis. No evidence of recurrence could be identified after 6 months. Like peripubertal and pregnant women, postmenopausal women treated with hormone replacement therapy may be at increased risk for pyogenic granuloma. Observational studies designed to establish an association between hormone replacement therapy and pyogenic granuloma have not been conducted. Dentists should be aware of putative pathophysiologic mechanisms for pyogenic granuloma formation and the possibility that hormone replacement may trigger these mechanisms. PMID:21409768

Johnson, Thomas M; Demsar, Williamr J; Herold, Robert W; Bisch, Frederick C; Gerlach, Robert C; Swiec, Gary D

2011-01-01

353

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

PubMed

Pyogenic granuloma, or granuloma pyogenicum, is a common, tumor-like growth of the oral cavity or skin that is considered to be an exaggerated, localized connective tissue reaction to a minor injury or irritation. A total of five clinical cases of oral pyogenic granuloma were randomly selected in the age group between 26 and 41 years. All these cases were treated with sodium tetra decyl sulphate and examined for regression and reccurrence of the lesion for six months. Various treatment modalities consist of conservative surgical excision, cryosurgery, laser surgery and sclerotherapy. Sclerotherapy with sodium tetra decyl sulphate is a relatively simple and effective method for treating oral pyogenic granuloma. PMID:24027901

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

2013-01-01

354

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

355

Population structure of Streptococcus oralis  

PubMed Central

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

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

2009-01-01

356

Streptococcus equi subspecies equi infection (strangles) in horses.  

PubMed

Streptococcus equi subspecies equi (strangles) is a highly contagious upper respiratory infection in horses. The infection is transmitted by inhalation or direct contact with mucopurulent discharge from an infective animal, resulting in fever, depression, and submandibular and retropharyngeal lymph node enlargement that can lead to respiratory distress. Complications include purpura hemorrhagica and metastatic abscessation. Control of outbreaks requires strict isolation protocols and hygiene measures. Detection of carriers is essential for preventing disease recurrence on a farm. PMID:21870348

Boyle, Ashley

2011-03-01

357

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

358

Group A Streptococcus tissue invasion by CD44-mediated cell signalling  

NASA Astrophysics Data System (ADS)

Streptococcus pyogenes (also known as group A Streptococcus, GAS), the agent of streptococcal sore throat and invasive soft-tissue infections, attaches to human pharyngeal or skin epithelial cells through specific recognition of its hyaluronic acid capsular polysaccharide by the hyaluronic-acid-binding protein CD44 (refs 1, 2). Because ligation of CD44 by hyaluronic acid can induce epithelial cell movement on extracellular matrix, we investigated whether molecular mimicry by the GAS hyaluronic acid capsule might induce similar cellular responses. Here we show that CD44-dependent GAS binding to polarized monolayers of human keratinocytes induced marked cytoskeletal rearrangements manifested by membrane ruffling and disruption of intercellular junctions. Transduction of the signal induced by GAS binding to CD44 on the keratinocyte surface involved Rac1 and the cytoskeleton linker protein ezrin, as well as tyrosine phosphorylation of cellular proteins. Studies of bacterial translocation in two models of human skin indicated that cell signalling triggered by interaction of the GAS capsule with CD44 opened intercellular junctions and promoted tissue penetration by GAS through a paracellular route. These results support a model of host cytoskeleton manipulation and tissue invasion by an extracellular bacterial pathogen.

Cywes, Colette; Wessels, Michael R.

2001-12-01

359

Laser: a powerful tool for treatment of pyogenic granuloma.  

PubMed

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

2011-05-01

360

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

361

Mechanism of Hyaluronan Degradation by Streptococcus pneumoniae Hyaluronate Lyase  

E-print Network

Mechanism of Hyaluronan Degradation by Streptococcus pneumoniae Hyaluronate Lyase STRUCTURES structures of Streptococcus pneumoniae hyaluro- nate lyase with tetra- and hexasaccharide hyaluronan may facilitate the binding of the negatively charged hyaluro- nan to the enzyme. Streptococcus

de Groot, Bert

362

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

363

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

364

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

365

Micromachined polymerase chain reaction system for multiple DNA amplification of upper respiratory tract infectious diseases.  

PubMed

This paper presents a micro polymerase chain reaction (PCR) chip for the DNA-based diagnosis of microorganism genes and the detection of their corresponding antibiotic-resistant genes. The micro PCR chip comprises cheap biocompatible soda-lime glass substrates with integrated thin-film platinum resistors as heating/sensing elements, and is fabricated using micro-electro-mechanical-system (MEMS) techniques in a reliable batch-fabrication process. The heating and temperature sensing elements are made of the same material and are located inside the reaction chamber in order to ensure a uniform temperature distribution. This study performs the detection of several genes associated with upper respiratory tract infection microorganisms, i.e. Streptococcus pneumoniae, Haemopilus influenze, Staphylococcu aureus, Streptococcus pyogenes, and Neisseria meningitides, together with their corresponding antibiotic-resistant genes. The lower thermal inertia of the proposed micro PCR chip relative to conventional bench-top PCR systems enables a more rapid detection operation with reduced sample and reagent consumption. The experimental data reveal that the high heating and cooling rates of the system (20 and 10 degrees C/s, respectively) permit successful DNA amplification within 15 min. The micro PCR chip is also capable of performing multiple DNA amplification, i.e. the simultaneous duplication of multiple genes under different conditions in separate reaction wells. Compared with the large-scale PCR system, it is greatly advantageous for fast diagnosis of multiple infectious diseases. Multiplex PCR amplification of two DNA segments in the same well is also feasible using the proposed micro device. The developed micro PCR chip provides a crucial tool for genetic analysis, molecular biology, infectious disease detection, and many other biomedical applications. PMID:15590288

Liao, Chia-Sheng; Lee, Gwo-Bin; Wu, Jiunn-Jong; Chang, Chih-Ching; Hsieh, Tsung-Min; Huang, Fu-Chun; Luo, Ching-Hsing

2005-01-15

366

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

367

Replacing and Additive Horizontal Gene Transfer in Streptococcus  

PubMed Central

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

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

2012-01-01

368

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

369

Pyogenic pancreatic abscess mimicking pancreatic neoplasm: a four-case series.  

PubMed

A pyogenic pancreatic abscess mimicking pancreatic neoplasm in the absence of acute pancreatitis is rare. We report four patients who each presented with a pancreatic mass at the pancreas head or body without acute pancreatitis. The presenting symptoms were abdominal pain, fever, or weight loss. Abdominal CT scans showed low-density round masses at the pancreas head or body with/without lymphadenopathy. In each case, a PET-CT scan showed a mass with a high SUV, indicating possible malignancy. Comorbid diseases were identified in all patients: chronic pancreatitis and thrombus at the portal vein, penetrating duodenal ulcer, distal common bile duct stenosis, and diabetes mellitus. Diagnoses were performed by laparoscopic biopsy in two patients and via EUS fine needle aspiration in one patient. One patient revealed a multifocal microabscess at the pancreatic head caused by a deep-penetrating duodenal ulcer. He was treated with antibiotics and a proton-pump inhibitor. The clinical symptoms and pancreatic images of all the patients were improved using conservative management. Infective causes should be considered for a pancreatic mass mimicking malignancy. PMID:25896161

Kim, Mi Jin; Seo, Eui Keun; Kang, Eun Seok; Kim, Keun Mo; Oh, Young Min; Cho, Byung Ha; Kim, Hyung Woo; Ji, Myoung Jin; Jeong, Ji Won; Park, Seon Mee

2015-04-25

370

Pyogenic vertebral osteomyelitis in a breast cancer patient: report of a case.  

PubMed

We herein report a rare case of pyogenic vertebral osteomyelitis (PVO) coexisting with breast carcinoma. A 71-year-old female presented with neck pain without fever. Magnetic resonance imaging (MRI) showed suspected metastatic lesions in her neck (C7 and Th1). Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) showed increased FDG uptake in the neck spines and in the left breast. A core needle biopsy of the left breast revealed the presence of invasive ductal carcinoma. Our first tentative diagnosis of the patient was left breast carcinoma with bone metastases, and first-line endocrine therapy was started. However, surgical intervention for the spines had to be considered, because her neurological symptoms progressed. A repeated MRI scan showed a narrowing of the disc space and fluid accumulation around the vertebrae. This suggested the presence of PVO rather than metastases. Surgery confirmed the presence of PVO in C7 and Th1, and a culture of the abscess yielded Escherichia coli. The patient's neurological symptoms dramatically improved after surgery. Breast conserving surgery was performed 3 months after the surgery for PVO. The patient is well and has no clinical evidence of disease 18 months after the breast conserving surgery. PVO is rare, but should be included in the differential diagnosis in patients presenting with early breast carcinoma. PMID:22382854

Zaha, Hisamitsu; Onomura, Mai; Nishikuramori, Yukiko

2012-10-01

371

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

2015-04-01

372

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

2015-02-01

373

Intrapartum antibiotic prophylaxis for Group B Streptococcus: has the time come to wait more than 4 hours?  

PubMed

Despite progress in preventing infant group B streptococcal disease, group B streptococcus remains the leading cause of early-onset neonatal sepsis in the United States. Fortunately, most women who are colonized with group B streptococcus receive therapy and antibiotic prophylaxis is effective. However, the only factor associated with missed chemoprophylaxis is the short duration of time between hospital admission and delivery. Although antibiotic prophylaxis given for at least 2 hours shows some pharmacological benefit, the most effective method of preventing early-onset group B streptococcus disease is 4 hours of therapy. Intrapartum management strategies might be modified to improve the efficacy of antibiotic exposure. Obstetricians should consider strengthening the beneficial effect of intrapartum antibiotic prophylaxis for infants exposed to group B streptococcus by providing at least 4 hours of treatment coverage. PMID:24315859

Turrentine, Mark

2014-07-01

374

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

PubMed

Trueperella (Arcanobacterium) pyogenes is an opportunistic animal pathogen, which in European bison is associated with different suppurative infections mainly of the urogenital tract. Little is known about the virulence of this bacterium and about the pathogenesis of infections. The main objective of this study was to determine phenotypic properties and virulence genotypes of the twenty-five T. pyogenes strains isolated from lesions in various tissues of free-living European bison. Classical bacteriological methods were used for phenotypic characterization. Genes encoding seven known and putative virulence factors of T. pyogenes were detected by PCR technique. Analysis of 16S rDNA partial sequences was performed to establish phylogenetic relationships of the isolated strains. All isolates showed typical morphological features of T. pyogenes and variable biochemical activity. Most of them displayed a strong positive effect in synergistic CAMP test. For all isolates the 16S rRNA gene partial sequence was identical to that of the T. pyogenes reference strain. All isolates carried the plo and fimA genes, while the nanH, nanP, cbpA, fimC and fimG genes were present in 40, 44, 12, 88 and 24% of the isolates, respectively. The T. pyogenes strains isolated from European bison represented various phenotypes and virulence genotypes, but there was no association between the investigated properties of the bacteria and the type of anatomopathological lesions from which they were isolated. These results indicate that the studied virulence factors of T. pyogenes are not significant determinants of the localization and type of infection caused by this bacterium. PMID:22658663

Rzewuska, Magdalena; Stefa?ska, Ilona; Osi?ska, Barbara; Kizerwetter-?wida, Magdalena; Chrobak, Dorota; Kaba, Jaros?aw; Bielecki, Wojciech

2012-11-01

375

Expression of Streptococcus mutans gtf genes in Streptococcus milleri.  

PubMed Central

The Streptococcus mutans glucosyltransferase (GTF) genes gtfB and gtfC were ligated into Escherichia coli-streptococcus shuttle plasmids and introduced into Streptococcus milleri. gtfB transformant KSB8 formed an S. mutans-like rough colony on mitis salivarius agar and expressed an extracellular GTF-I, of 158 kDa, and two cell-bound GTF-Is, of 158 and 135 kDa. gtfC transformant KSC43 formed a semirough colony on mitis salivarius agar and expressed primarily an extracellular GTF-SI, of 146 kDa, and two cell-bound GTF-SIs, of 146 and 152 kDa. The extracellular GTFs from KSB8 and KSC43 were purified and characterized. The two types of GTF also reacted specifically with monoclonal antibodies directed against each enzyme. Both enzymes synthesized significant amounts of oligosaccharides, consisting primarily of alpha-1,6-glucosidic linkages, as well as water-insoluble glucans, containing alpha-1,3-glucosidic linkages. Insoluble-glucan-synthesizing activities of both enzymes were stimulated (three- to sixfold) by the addition of dextran T10 and were inhibited in the presence of 1.5 M ammonium sulfate. The Km(s) for sucrose and the optimal pHs were also similar for both enzymes. However, when the transformants were grown in Todd-Hewitt broth supplemented with sucrose, KSC43 cells, expressing GTF-SI activity, adhered to glass surfaces in vitro, while KSB8 cells, expressing GTF-I activity, did not. These results are discussed relative to the potential role of the gtfB and gftC genes in S. mutans cariogenicity. Images PMID:1377183

Fukushima, K; Ikeda, T; Kuramitsu, H K

1992-01-01

376

ORIGINAL ARTICLE M1T1 group A streptococcal pili promote epithelial  

E-print Network

A Streptococcus is a leading human pathogen associated with a diverse array of mucosal and systemic infections-009-0566-9 #12;Introduction Streptococcus pyogenes (group A Streptococcus (GAS)) is a leading human pathogen-threatening pneumonia, necrotizing fasciitis (NF) and toxic shock syndrome (TSS) [3]. A resurgence of severe GAS disease

Nizet, Victor

377

Human meningitis caused by Streptococcus suis.  

PubMed

Streptococcus suis is an important swine pathogen worldwide, which can be transmitted to human beings by direct contact; therefore, S. suis infections occur mainly in people who handle pigs or pork. We present a case of a patient with S. suis meningitis who worked as a butcher in a meat processing plant for 5 years. The 35-year-old man was admitted to the Department of Infectious Diseases in T. Browicz Memorial Central Infectious Disease and Observation Hospital in Bydgoszcz, Poland, with suspected bacterial meningitis. According to his medical history, the patient had been injured during the processing of pork. A microbiological examination of the cerebrospinal fluid and blood revealed S. suis as a single aetiological factor of this infection. The patient was empirically administered cefotaxime (2.0 g at 8-h intervals) and penicillin (9 million U at 8-h intervals). The patient made a complete recovery and his inflammatory markers normalized. Only the hearing deficit of his right ear did not disappear. An otolaryngologist recommended a 4-week steroid therapy. The patient was not examined because he did not report to the clinic. To our knowledge this is the first described case of human meningitis caused by S. suis in Poland. PMID:23222864

Zalas-Wiecek, Patrycja; Michalska, Anna; Grabczewska, Edyta; Olczak, Anita; Pawlowska, Malgorzata; Gospodarek, Eugenia

2013-03-01

378

Multicenter Clinical Evaluation of the illumigene Group A Streptococcus DNA Amplification Assay for Detection of Group A Streptococcus from Pharyngeal Swabs  

PubMed Central

Acute pharyngitis is a nonspecific symptom that can result from a number of viral or bacterial infections. For most etiologies, symptoms are self-limited and resolve without lasting effects; however, pharyngitis resulting from infection with Streptococcus pyogenes (a group A Streptococcus [GAS]) can be associated with serious sequelae, including acute rheumatic fever and acute glomerulonephritis. Rapid accurate detection of GAS in pharyngeal specimens from individuals suffering from pharyngitis aids in the management and selection of antibiotic therapy for these patients. A total of 796 pharyngeal swabs were collected at three separate clinical centers. Each specimen was analyzed using the illumigene group A strep DNA amplification assay (Meridian Bioscience Inc., Cincinnati, OH). To confirm GAS identification, the results were compared to those from direct and extracted culture methods using Gram staining and a GAS-specific latex agglutination test. Discrepant results were resolved using an alternative nucleic acid amplification test. The prevalence of culture-detected GAS in this study was 12.8% (102/796 specimens). The illumigene assay detected GAS in 74/74 direct culture-positive specimens (100% sensitivity) and 100/102 extracted culture-positive specimens (98.0% sensitivity). GAS was detected by the illumigene assay in an additional 42 specimens that were direct culture negative (94.2% specificity) and 16 specimens that were extracted culture negative (97.7% specificity). Discrepant analysis using an alternative molecular assay detected GAS nucleic acid in 13/16 (81.3%) false-positive specimens and 1/2 false-negative specimens, resulting in a final sensitivity of 99.0% and a specificity of 99.6% for the detection of GAS in pharyngeal swabs using the illumigene assay. PMID:23447639

Anderson, Neil W.; Buchan, Blake W.; Mayne, Donna; Mortensen, Joel E.; Mackey, Tami-Lea A.

2013-01-01

379

Genotypic characterization and evaluation of an antibiotic resistance of Trueperella pyogenes (Arcanobacterium pyogenes) isolated from milk of dairy cows with clinical mastitis.  

PubMed

Trueperella pyogenes, recently reclassified from the genus Arcanobacterium, is considered the causative agent of acute suppurative mastitis called summer mastitis. T. pyogenes produces a variety of known and putative virulence factors that include pyolysin and factors promoting adhesion to host cells. The objective of this study was to report the presence of virulence genes in T. pyogenes isolates that were identified as etiological agents of clinical mastitis in cows, as well as to determine antimicrobial resistance and distribution of selected determinants that can be associated with phenotypic resistance among these isolates. The presence of genes (plo, nanH, nanP, cbpA, fimA, fimC, fimE, fimG, tet(W), erm(X), erm(B)) was examined by conventional PCRs. Resistance to 10 antimicrobial agents was determined by the broth microdilution method. Among T. pyogenes isolates of bovine mastitis origin the genes encoding all virulence factors occurred. Besides pyolysin gene plo, the fimA was the only gene detected in all isolates, whereas other virulence factor genes were found with different frequencies. Phenotypic antimicrobial resistance was observed to tetracycline (85.5% isolates) and erythromycin (9.1%). Isolates non-susceptible to erythromycin simultaneously exhibited increased MIC of pirlimycin. Beta-lactams were active against isolates. We found the correlation between the presence of tetracycline and macrolide resistance genes and corresponding resistance phenotype. Genotypic characterization of a large number of T. pyogenes isolates from different herds performed in this study may be useful in explanation, which virulence factors play a significant role in the establishment of bovine mammary gland infection. PMID:22868181

Zastempowska, Ewa; Lassa, Henryka

2012-12-28

380

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

381

The antemortem diagnosis of pyogenic liver abscess due to perforation of the gut by a foreign body  

Microsoft Academic Search

Perforation of the gastrointestinal tract by ingested foreign bodies is rare; the diagnosis of pyogenic liver abscess resulting from such perforations is usually made at post-mortem. We present a case of perforation of the gut, due to an ingested dental plate, with a resultant pyogenic liver abscess, which presented as a pyrexia of unknown origin.

P. J. Shaw; J. G. Freeman

1983-01-01

382

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

383

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

384

Efficacy of an experimentally inactivated Streptococcus agalactiae vaccine in Nile tilapia (Oreochromis niloticus) reared in Brazil  

Technology Transfer Automated Retrieval System (TEKTRAN)

Tilapia aquaculture is one of the fastest growing segments of fish production in Brazil. Nile tilapia (Oreochromis niloticus) is largely cultivated in the state of Parana, where Streptococcus agalactiae is the cause of severe disease outbreaks. The objective of this paper was to evaluate an inactiva...

385

Capsular Serotype and Antibiotic Resistance of Streptococcus pneumoniae Isolates in Two Chilean Cities  

Microsoft Academic Search

We compared the incidence of nasopharyngeal colonization by Streptococcus pneumoniae, the serotypes causing mucosal and invasive diseases, and the antibiotic resistance of these strains in patients admitted to three large hospitals and children attending day care centers in two Chilean cities (Santiago and Temuco). The populations in both cities were similar in ethnic background, socioeconomic status, family size, and access

JAIME INOSTROZA; OLIVIA TRUCCO; VALERIA PRADO; ANA MARIA VINET; GLORIA RETAMAL; GONZALO OSSA; RICHARD R. FACKLAM; RICARDO U. SORENSEN

1998-01-01

386

High Prevalence of Antimicrobial Resistance among Clinical Streptococcus pneumoniae Isolates in Asia (an ANSORP Study)  

Microsoft Academic Search

A total of 685 clinical Streptococcus pneumoniae isolates from patients with pneumococcal diseases were collected from 14 centers in 11 Asian countries from January 2000 to June 2001. The in vitro susceptibilities of the isolates to 14 antimicrobial agents were determined by the broth microdilution test. Among the isolates tested, 483 (52.4%) were not susceptible to penicillin, 23% were intermediate,

Jae-Hoon Song; Sook-In Jung; Kwan Soo Ko; Na Young Kim; Jun Seong Son; Hyun-Ha Chang; Hyun Kyun Ki; Won Sup Oh; Ji Yoeun Suh; Kyong Ran Peck; Nam Yong Lee; Yonghong Yang; Quan Lu; Anan Chongthaleong; Cheng-Hsun Chiu; M. K. Lalitha; Jennifer Perera; Ti Teow Yee; Gamini Kumarasinghe; Farida Jamal; Adeeba Kamarulzaman; N. Parasakthi; P. H. Van; C. Carlos; T. So; T. K. Ng; A. Shibl

2004-01-01

387

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...

388

Use of a Bacteriophage Lysin, PlyC, as an Enzyme Disinfectant against Streptococcus equi  

Microsoft Academic Search

Streptococcus equi is the causative agent of the purulent infection equine strangles. This disease is trans- mitted through shedding of live bacteria from nasal secretions and abscess drainage or by contact with surfaces contaminated by the bacteria. Disinfectants are effective against S. equi, but inactivation by environmental factors, damage to equipment, and toxicity are of great concern. Bacteriophage-encoded lysins (cell

J. Todd Hoopes; Caren J. Stark; Han Ah Kim; Daniel J. Sussman; David M. Donovan; Daniel C. Nelson

2009-01-01

389

The molecular mechanisms of streptococcus gordonii-platelet interactions involved in the pathogenesis of cardiovascular infection  

Microsoft Academic Search

Numerous studies have implicated bacteria in cardiovascular disease; however the mechanisms involved have yet to be elucidated. Infective Endocarditis (IE) is characterised by the formation of platelet-bacteria thrombi on a heart valve which, if untreated, can lead to valve failure or the formation of infected emboli. The oral bacterium, Streptococcus gordonii, is amongst the most common pathogens isolated from IE

Ciara Keane

2010-01-01

390

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

391

The pathogenesis of the meningitis caused by Streptococcus suis: the unresolved questions  

Microsoft Academic Search

Streptococcus suis is one of the most important swine pathogens world-wide. Among the serotypes described, type 2 is the serotype most frequently associated with disease. Despite increasing research in recent years, knowledge of virulence factors and the pathogenesis of the infection remain limited. This review discusses the currently available information on S. suis serotype 2 virulence factors and the pathogenesis

Marcelo Gottschalk; Mariela Segura

2000-01-01

392

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

393

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

394

Suburethral vaginal erosion and pyogenic granuloma formation: an unusual complication of intravaginal slingplasty (IVS).  

PubMed

We report an unusual case of suburethral vaginal erosion and pyogenic granuloma formation 14 months after intravaginal slingplasty (IVS). A 64-year-old woman underwent IVS for recurrent stress incontinence 12 years after Burch colposuspension. Following seemingly uncomplicated surgery and recovery, she developed a recurrent urinary tract infection which was treated with antibiotics. When she presented with vaginal pain and postmenopausal bleeding approximately 14 months postoperatively, she was found to have suburethral vaginal erosion of the tape and a pyogenic granuloma. The exposed tape was removed, the granuloma excised, and the overlying vaginal skin was then closed. She then made an uneventful recovery. PMID:14752602

Lim, Y N; Rane, A

2004-01-01

395

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

PubMed

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

Czaba?ska, Anna; Neiwert, Olga; Lindner, Buko; Leigh, James; Holst, Otto; Duda, Katarzyna A

2012-11-01

396

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

397

Horizontal transmission of streptococcus mutans in schoolchildren  

PubMed Central

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

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

2012-01-01

398

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

399

Pyogenic, tuberculous, and brucellar vertebral osteomyelitis: a descriptive and comparative study of 219 cases  

PubMed Central

OBJECTIVES—To describe a large series of patients with vertebral osteomyelitis (VO), and to compare the clinical, biological, radiological, and prognostic features of pyogenic (PVO), tuberculous (TVO), and brucellar vertebral osteomyelitis (BVO).?METHODS—A retrospective multicentre study, which included 219 adult patients with VO with confirmed aetiology, who were diagnosed between 1983 and 1995 in two tertiary care centres. Of these patients, 105 (48%) had BVO, 72 (33%) PVO, and 42 (19%) TVO.?RESULTS—One hundred and forty eight (67.6%) patients were male and 71 (32.4%) female. The mean (SD) age was 50.4 (16.4) years (range 14-84) and the mean (SD) duration of symptoms before the diagnosis was 14 (16.8) weeks. In 127 patients (57.9%) the vertebral level involved was lumbar, in 70 (31.9%) thoracic, and in 16 (7.3%) cervical. One hundred and nineteen patients (54.4%) received only medical treatment and 100 (45.6%) required both medical and surgical treatment. The presence of diabetes mellitus, intravenous drug abuse, underlying chronic debilitating diseases or immunosuppression, previous infections, preceeding bacteraemia, recent vertebral surgery, leucocytosis, neutrophilia, and increased erythrocyte sedimentation rate (ESR) were significantly associated to PVO. A prolonged clinical course, thoracic segment involvement, absence of fever, presence of spinal deformity, neurological deficit, and paravertebral or epidural masses, were significantly more frequent in the group of TVO. The need for surgical treatment and the presence of severe functional sequelae were more frequent in the groups of PVO and TVO.?CONCLUSION—There are significant clinical, biological, radiological, and prognostic differences between BVO, PVO, and TVO. These differences can point to the causal agent and orient the initial empirical medical treatment while awaiting a final microbiological diagnosis.?? PMID:9496149

Colmenero, J; Jimenez-Mejias, M; Sanchez-Lora, F; Reguera, J; Palomino-Nicas, J; Martos, F; Heras, J; Pachon, J

1997-01-01

400

Segmental cholangiectasia clinically worrisome for cholangiocarcinoma: comparison with recurrent pyogenic cholangitis.  

PubMed

The aim of this study was to review the clinical, radiographic, and pathologic features of cases of benign segmental cholangiectasia in non-Asian US patients with clinical concern for cholangiocarcinoma and compare these features with cases of recurrent pyogenic cholangitis (RPC) in Asian patients. A total of 10 non-Asian US patients with benign segmental cholangiectasia were included in this study. Nine of them underwent partial hepatic resection due to cholangiographic findings of segmental cholangiectasia with mural thickening and/or proximal biliary stricture. One was found to have markedly dilated and thickened intrahepatic bile ducts at the time of autopsy. Clinical and radiographic findings were reviewed. Elastin stains and immunostains for immunoglobulin G4, cluster of differentiation (CD1a), and Langerin were performed. Six comparison cases of RPC in Asian US patients were also examined. Histologic examination of resection specimens revealed markedly dilated large intrahepatic bile ducts with variable degrees of mural fibrosis, periductal gland hyperplasia, inflammation, and liver parenchymal atrophy. These changes were not associated with a ductular reaction. There was no evidence of biliary dysplasia or biliary cirrhosis in any cases. No gross or microscopic feature definitively separated the Asian from non-Asian patients. The etiology of this disorder in non-Asian US patients is unclear. It does not appear to represent a localized variant of Caroli disease or primary sclerosing cholangitis. The high degree of similarity shared by these cases and classic RPC suggests a common pathogenic mechanism, although the pathologic features tend to be less well developed in the cases from the non-Asian US patients. PMID:25600951

Zhao, Lei; Hosseini, Mojgan; Wilcox, Rebecca; Liu, Qiang; Crook, Terri; Taxy, Jerome B; Ferrell, Linda; Hart, John

2015-03-01

401

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

402

Pyogenic and non-pyogenic spinal infections: emphasis on diffusion-weighted imaging for the detection of abscesses and pus collections.  

PubMed

The incidence of spinal infections has increased in the past two decades, owing to the increasing number of elderly patients, immunocompromised conditions, spinal surgery and instrumentation, vascular access and intravenous drug use. Conventional MRI is the gold standard for diagnostic imaging; however, there are still a significant number of misdiagnosed cases. Diffusion-weighted imaging (DWI) with a b-value of 1000 and apparent diffusion coefficient (ADC) maps provide early and accurate detection of abscess and pus collection. Pyogenic infections are classified into four types of extension based on MRI and DWI findings: (1) epidural/paraspinal abscess with spondylodiscitis, (2) epidural/paraspinal abscess with facet joint infection, (3) epidural/paraspinal abscess without concomitant spondylodiscitis or facet joint infection and (4) intradural abscess (subdural abscess, purulent meningitis and spinal cord abscess). DWI easily detects abscesses and demonstrates the extension, multiplicity and remote disseminated infection. DWI is often a key image in the differential diagnosis. Important differential diagnoses include epidural, subdural or subarachnoid haemorrhage, cerebrospinal fluid leak, disc herniation, synovial cyst, granulation tissue, intra- or extradural tumour and post-surgical fluid collections. DWI and the ADC values are affected by susceptibility artefacts, incomplete fat suppression and volume-averaging artefacts. Recognition of artefacts is essential when interpreting DWI of spinal and paraspinal infections. DWI is not only useful for the diagnosis but also for the treatment planning of pyogenic and non-pyogenic spinal infections. PMID:24999081

Moritani, T; Kim, J; Capizzano, A A; Kirby, P; Kademian, J; Sato, Y

2014-09-01

403

Molecular identification and further characterization of Arcanobacterium pyogenes isolated from bovine mastitis and from various other origins.  

PubMed

The present study was designed to identify phenotypically and genotypically 61 Arcanobacterium pyogenes isolated from bovine mastitis and from various other origins. The A. pyogenes isolates showed the typical cultural and biochemical properties of this species and displayed CAMP-like synergistic hemolytic activities with various indicator strains. The species identity could be confirmed genotypically by amplification and sequencing of the superoxide dismutase A encoding gene sodA of reference strains representing 8 species of genus Arcanobacterium and subsequent design of A. pyogenes sodA gene-specific oligonucleotide primer. The A. pyogenes sodA gene-specific oligonucleotide primer allowed, together with previously described A. pyogenes 16S-23S rDNA intergenic spacer region-specific oligonucleotide primer, a reliable molecular identification of all 61 A. pyogenes of various origins. The additionally performed PCR-mediated amplification of 5 known and putative virulence factor encoding genes revealed that 100, 20, 87, 75, and 98% of the A. pyogenes carried the genes plo, cbpA, nanH, nanP, and fimA, which allowed an individual strain characterization. This might help to elucidate the role the putative virulence factors play in bovine mastitis and in various other infections caused by this bacterial pathogen. PMID:21426970

Hijazin, M; Ulbegi-Mohyla, H; Alber, J; Lämmler, C; Hassan, A A; Abdulmawjood, A; Prenger-Berninghoff, E; Weiss, R; Zschöck, M

2011-04-01

404

Acute Pyogenic Arthritis of the Hip: An Operation Giving Free Access and Effective Drainage  

PubMed Central

Dr. Gathorne R. Girdlestone is shown at a Wingfield Hospital fête. Figure reprinted with permission of the Oxfordshire Health Archives, Oxfordshire, UK. Gathorne Robert Girdlestone was born in 1881, the son of the Rev. R.B. Girdlestone, Honorary Canon of Christ Church, Oxford [3]. His early education was at Charterhouse, then he read medicine at New College, Oxford. Girdlestone received his subsequent medical training at St. Thomas’ Hospital, London, completing his house appointment there. He subsequently went to Oswestry, where he was influenced by Sir Robert Jones. During WW I he returned to Oxford to assume charge of a military hospital that eventually had over 400 beds. The Wingfield Convalescent Home, an “old fashioned institution,” [3] was located in Headington, then a village near Oxford, and Girdlestone’s initial military hospital consisted largely of open air huts on the Wingfield grounds. Girdlestone continued to work there and at the Radcliffe Infirmary after the war. These huts were, through the benefaction of Sir William Morris (the founder of Morris Motors and later elevated to Lord Nuffield), replaced with modern buildings beginning in 1930 with a bequest of £70,000 [4]. These new buildings, initially named the Wingfield-Morris Orthopaedic Hospital, were opened by the Prince of Wales in 1933. As a result of his work and stature and perhaps his relationship with Lord Nuffield, Girdlestone was appointed in 1937 the first British Professor of Orthopaedic Surgery. (Oxford Medical School eventually received £2,000,000 from Lord Nuffield [3].) The Wingfield-Morris Orthopaedic Hospital became part of the National Health Service in 1948, then was renamed the Nuffield Orthopaedic Centre in 1950, the year of Girdlestone’s death. It is fair to say that Girdlestone was among the primary and most influential individuals creating a specialty of orthopaedic surgery in the first half of the 20th century. Girdlestone wrote at least two articles describing excision arthroplasty of the hip. The first, from 1928, described a radical excision for draining tuberculous hips [1] and the second (reprinted here), from 1942, a related and perhaps at times even more radical operation for pyogenic infections [2]. Girdlestone emphasized these radical operations were intended only for severe infections, and readers are reminded these were both published in the preantibiotic era, when radical surgery was often required to save a patient’s life. In the first article, he also emphasized the principle of “removal of diseased and devitalized tissues, flattening down of dead spaces, and leaving drainage so complete and lasting as will allow the wound to heal from the bottom” [1]. He excised the greater trochanter and all involved muscles, suturing skin edges deep into the wound so as to achieve effective drainage. When necessary, he also “flattened” the edges of the acetabulum. In the second article he suggested less radical operations were often ineffective in pyogenic infections owing to the “miniature rabbit-warren of sinuses and cavities” [2]. The techniques were fundamentally similar to those he had earlier described for tuberculosis. He used a wide transverse incision (Fig. 2) to access the hip, excising all lateral musculature along with the trochanter and the lateral margin of the acetabulum (Fig. 1). In the presence of infection in the intermuscular planes, he avoided suturing the skin deeply, and rather packed the wound with Vaseline gauze and rubber drains (Fig. 4). The postoperative care included splinting either on a frame (if good nursing care was available) or spica casting with a large window. Readers familiar with operations for infected total hip arthroplasties will immediately recognize current procedures are far less radical than those typically used in Girdlestone’s time. Rarely would an infected arthroplasty be treated with such radical excision of bone and muscle, open packing, and secondary healing. For t

2008-01-01

405

Sensitive and rapid detection of Trueperella pyogenes using loop-mediated isothermal amplification method.  

PubMed

Here we report the design and evaluation of a loop-mediated isothermal amplification (LAMP) assay for detecting Trueperella pyogenes DNA based on the plo gene sequence that encodes pyolysin. The results showed that target DNA was amplified specifically and with a detection limit 100-fold greater than PCR. PMID:23517678

Zhang, Wenlong; Meng, Xiangli; Wang, Junwei

2013-05-01

406

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

407

Real-time PCR for detection and differentiation of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus.  

PubMed

Strangles is a contagious equine disease caused by Streptococcus equi subsp. equi. In this study, clinical strains of S. equi (n=24) and Streptococcus equi subsp. zooepidemicus (n=24) were genetically characterized by sequencing of the 16S rRNA and sodA genes in order to devise a real-time PCR system that can detect S. equi and S. zooepidemicus and distinguish between them. Sequencing demonstrated that all S. equi strains had the same 16S rRNA sequence, whereas S. zooepidemicus strains could be divided into subgroups. One of these (n=12 strains) had 16S rRNA sequences almost identical with the S. equi strains. Interestingly, four of the strains biochemically identified as S. zooepidemicus were found by sequencing of the 16S rRNA gene to have a sequence homologous with Streptococcus equi subsp. ruminatorum. However, they did not have the colony appearance or the biochemical characteristics of the type strain of S. ruminatorum. Classification of S. ruminatorum may thus not be determined solely by 16S rRNA sequencing. Sequencing of the sodA gene demonstrated that all S. equi strains had an identical sequence. For the S. zooepidemicus strains minor differences were found between the sodA sequences. The developed real-time PCR, based on the sodA and seeI genes was compared with conventional culturing on 103 cultured samples from horses with suspected strangles or other upper respiratory disease. The real-time PCR system was found to be more sensitive than conventional cultivation as two additional field isolates of S. equi and four of S. zooepidemicus were detected. PMID:17531409

Båverud, V; Johansson, S K; Aspan, A

2007-10-01

408

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

409

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

410

Biofilm formation in Streptococcus pneumoniae  

PubMed Central

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

Domenech, Mirian; García, Ernesto; Moscoso, Miriam

2012-01-01

411

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

412

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

413

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 f