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Sample records for streptococcus pyogenes isolates

  1. Molecular typing of Chinese Streptococcus pyogenes isolates.

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

    2015-06-01

    Streptococcus pyogenes causes human infections ranging from mild pharyngitis and impetigo to serious diseases including necrotizing fasciitis and streptococcal toxic shock syndrome. The objective of this study was to compare molecular emm typing and pulsed field gel electrophoresis (PFGE) with multiple-locus variable-number tandem-repeat analysis (MLVA) for genotyping of Chinese S. pyogenes isolates. Molecular emm typing and PFGE were performed using standard protocols. Seven variable number tandem repeat (VNTR) loci reported in a previous study were used to genotype 169 S. pyogenes geographically-diverse isolates from China isolated from a variety of disease syndromes. Multiple-locus variable-number tandem-repeat analysis provided greater discrimination between isolates when compared to emm typing and PFGE. Removal of a single VNTR locus (Spy2) reduced the sensitivity by only 0.7%, which suggests that Spy2 was not informative for the isolates screened. The results presented support the use of MLVA as a powerful epidemiological tool for genotyping S. pyogenes clinical isolates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Highly virulent M1 Streptococcus pyogenes isolates resistant to clindamycin.

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    Plainvert, C; Martin, C; Loubinoux, J; Touak, G; Dmytruk, N; Collobert, G; Fouet, A; Ploy, M-C; Poyart, C

    2015-01-01

    Emm1-type group A Streptococcus (GAS), or Streptococcus pyogenes, is mostly responsible for invasive infections such as necrotizing fasciitis (NF) and streptococcal toxic shock syndrome (STSS). The recommended treatment of severe invasive GAS infections is a combination of clindamycin and penicillin. Until 2012, almost all emm1 isolates were susceptible to clindamycin. We aimed to identify the phenotypic and genotypic characteristics of emm1 GAS clone resistant to clindamycin. GAS strains were characterized by emm sequence typing, detection of genes encoding pyrogenic exotoxins or superantigens. Cluster analysis was performed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Antibiotic susceptibility was assessed using disk diffusion and resistance genes were detected by PCR. A total of 1321 GAS invasive isolates were analyzed between January 2011 and December 2012. The overall number of invasive isolates resistant to clindamycin was 52 (3.9%); seven of them were emm1 isolates. All isolates had the same genomic markers: macrolide resistance due to the presence of the erm(B) gene, emm subtype 1.0, the same toxin or superantigen profile, PFGE pattern and sequence type. This is the first description of highly virulent GAS emm1 isolates resistant to clindamycin in France. This article strengthens the need for monitoring the epidemiology of invasive GAS strains as they could lead to changes in treatment guidelines. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  3. Characterisation of clinically isolated Streptococcus pyogenes from balanoposthitis patients, with special emphasis on emm89 isolates.

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    Hasegawa, Tadao; Hata, Nanako; Matsui, Hideyuki; Isaka, Masanori; Tatsuno, Ichiro

    2017-04-01

    Streptococcus pyogenes causes a variety of diseases, such as pharyngitis and toxic shock syndrome. In addition, this bacterium is a causative agent of balanoposthitis. To reveal the bacteriological characteristics of the isolates from balanoposthitis patients, we analysed 47 isolates. In addition, novel clade genotype emm89 S. pyogenes isolates have been reported to be spreading worldwide recently. Hence, we further analysed eight emm89 isolates. A drug susceptibility experiment was performed and emm types were determined. More detailed experiments, such as PCR analysis for the presence of virulence-associated genes and MLST analysis, were performed especially using emm89 isolates. All isolates were sensitive to ampicillin, but 34 % of the isolates were resistant to at least one antibiotic. The emm types of the isolates varied, with emm89 and emm11 being the most prevalent, but the emm1 type was not detected. The analysis of emm89 isolates revealed that drug susceptibilities varied. All isolates were negative for the hasABC gene and produced active NADase that are characteristics of novel clade genotype emm89 S. pyogenes. MLST analysis demonstrated that six isolates were of the ST101 type, the most predominant type reported thus far, but two isolates were of the ST646 type. According to the PCR analysis used to determine the presence of streptococcal pyrogenic exotoxin-related genes, the six ST101 isolates were further classified into four groups. These results suggest that balanoposthitis is caused by a variety of types of S. pyogenes, with novel clade genotype emm89 isolates playing a role in balanoposthitis infections in Japan.

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

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

    2014-12-01

    To produce an effective recombinant streptokinase (rSK) from pathogenic Streptococcus pyogenes isolate in yeast, and evaluate its potential for thrombolytic therapy. 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. 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. 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. 

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

    Science.gov (United States)

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

    2014-01-01

    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

  6. Erythromycine resistance in streptococcus pyogenes group a throat isolates in sukkur city

    International Nuclear Information System (INIS)

    Memon, B.

    2007-01-01

    To examine and evaluate the predominant and common etiologic agent(s) of pharyngitis in Sukkur city and to determine their current antibiotic susceptibility/resistance trends. Out of 257 throat samples, 149 positive for Streptococcus pyogenes Group A between November 2001 and May 2003 from adult population of Sukkur city were tested for their susceptibility to erythromycin, clindamycin, azithromycin and clairithromycin. The throat samples (swabs) were examined by Gram-stain, API system, and for presence of a hemolysis. Samples were further cultured on Muller Hinton agar for determination of antibiotic sensitivity patterns. The sensitivity was performed on only those samples which were positive for S. pyogenes. Of all throat isolates, 95% were predominantly resistant to erythromycin. Their sensitivity towards clindamycin was 30%, azithromycin 44% and clairithromycin 76% respectively. The current pharyngeal isolates of S. pyogenes exhibited frequent and alarmingly high erythromycin resistance which may be due to both intrinsic and acquired mechanisms. (author)

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

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

    2014-02-01

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

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

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    Surasak Limsuwan

    2012-01-01

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

  9. Streptococcus pyogenes emm types and subtypes of isolates from paediatric asymptomatic carriers and children with pharyngitis.

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    Blandino, Giovanna; Puglisi, Salvatore; Speciale, Annamaria; Musumeci, Rosario

    2011-01-01

    This study determined emm subtypes of Streptococcus pyogenes strains isolated from asymptomatic carriers and children with pharyngitis. All strains were previously investigated for fibronectin-binding genes (prtF1 and prtF2) and antimicrobial susceptibility. The most significant differences between the two groups, which share only 5 of the 14 detected emmsubtypes, concern the presence of the two more common emmsubtypes, 12.0 (50.0% vs. 3.1%, for asymptomatic carriers and children with pharyngitis, respectively) and 1.0 (28.1% vs. 0%, for children with pharyngitis and asymptomatic carriers, respectively).

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

    OpenAIRE

    Watanabe, Shinya; Sasahara, Teppei; Arai, Naoshi; Sasaki, Kazumasa; Aiba, Yoshifumi; Sato?o, Yusuke; Cui, Longzhu

    2016-01-01

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

  11. Detection of invasive protein profile of Streptococcus pyogenes M1 isolates from pharyngitis patients.

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    Hasegawa, Tadao; Okamoto, Akira; Kamimura, Takuya; Tatsuno, Ichiro; Hashikawa, Shin-Nosuke; Yabutani, Mitsutaka; Matsumoto, Masakado; Yamada, Keiko; Isaka, Masanori; Minami, Masaaki; Ohta, Michio

    2010-03-01

    Streptococcal toxic shock syndrome (STSS) is a re-emerging infectious disease in Japan and many other developed countries. Epidemiological studies have revealed that the M1 serotype of Streptococcus pyogenes is the most dominant causative isolate of STSS. Recent characterization of M1 isolates revealed that the mutation of covS, one of the two-component regulatory systems, plays an important role in STSS by altering protein expression. We analyzed the M1 S. pyogenes clinical isolates before or after 1990 in Japan, using two-dimensional gel electrophoresis (2-DE) and pulsed-field gel electrophoresis (PFGE). PFGE profiles were different between the isolates before and after 1990. Markedly different profiles among isolates after 1990 from STSS and pharyngitis patients were detected. Sequence analysis of two-component regulatory systems showed that covS mutations were detected not only in STSS but also in three pharyngitis isolates, in which proteins from the culture supernatant displayed the invasive type. The mutated CovS detected in the pharyngitis isolates had impaired function on the production of streptococcal pyrogenic exotoxin B (SpeB) analyzed by 2-DE. These results suggest that several covS mutations that lead to the malfunction of the CovS protein occurred even in pharyngeal infection.

  12. Comparative genomics of Streptococcus pyogenes M1 isolates differing in virulence and propensity to cause systemic infection in mice

    NARCIS (Netherlands)

    Fiebig, A.; Loof, T.G.; Babbar, A.; Itzeg, A.; Koehorst, J.J.; Schaap, P.J.; Nitsche-Schmitz, D.P.

    2015-01-01

    Streptococcus pyogenes serotype M1 is a frequent cause of severe infections in humans. Some M1 isolates are pathogenic in mice and used in studies on infection pathogenesis. We observed marked differences in murine infections caused by M1 strain SF370, 5448, 5448AP or AP1 which prompted us to

  13. Isolation and immunochemical characterization of carbohydrate antigens prepared from group A Streptococcus pyogenes.

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    Hamada, S; Okahashi, N; Yamamoto, T; Morisaki, I; Michalek, S M; McGhee, J R

    1983-11-01

    Group A carbohydrate antigens were prepared from isolated cell walls or whole cells of Streptococcus pyogenes strain Sv (group A, M type 3). Cell walls were lysate by the enzymatic action of M1 endo-N-acetylmuramidase. The cell wall lysate was concentrated and chromatographed on a Sephadex G-100 column. Two fractions reactive with group A antisera were obtained. These were composed of N-acetylglucosamine, rhamnose, and peptidoglycan components such as glutamic acid, lysine, alanine, N-acetylmuramic acid and N-acetylglucosamine. For comparison, hot TCA extract of the cell walls (TCAgA) or Rantz and Randall extract of the whole cells (RRgA) was purified chromatographically. The latter two also contained rhamnose and glucosamine, and were reactive with group A antisera. The molecular weights of M1gA antigens were larger than those of TCAgA and RRgA. Hapten inhibition study indicated that N-acetylglucosamine was the most potent inhibitor.

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

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

    2015-07-01

    A steady increase in macrolide resistance in Streptococcus pyogenes, group A streptococci (GAS) was reported in Serbia during 2004-2009 (9.9%). However, there are no data on the molecular epidemiology of pharyngeal macrolide resistance GAS (MRGAS) isolates. Therefore, the aims of this first nationwide study were to examine the prevalence of macrolide resistance in Serbian GAS and to determine their resistance phenotypes, genotypes and clonal relationships. Overall 3893 non-duplicate pharyngeal S. pyogenes isolates from outpatients with GAS infection were collected throughout country during 2008 and 2009. Among 486 macrolide resistant pharyngeal isolates collected, 103 were further characterized. Macrolide resistance phenotypes and genotypes were determined by double-disk diffusion test and PCR, respectively. Strain relatedness was determined by emm typing, multilocus sequence typing (MLST), multilocus variable tandem repeat analysis (MLVA), phage profiling (PP) and virulence factor profiling (VFP). Overall, macrolide resistance among GAS isolates in Serbia was 12.5%. M phenotype was the most common (71.8%), followed by iMLS (18.4%) and cMLS (9.7%). Three clonal complexes--emm75/mefA/ST49, emm12/mefA/ST36 and emm77/ermA/tetO/ST63 comprised over 90% of the tested strains. Although MLVA, PP and VFP distinguished 10, 20 and 12 different patterns, respectively, cluster analysis disclosed only small differences between strains which belonged to the same emm/ST type. Our data indicate dominance of three major internationally widely disseminated macrolide resistant clones and a high genetic homogeneity among the Serbian MRGAS population. Continued surveillance of macrolide resistance and clonal composition in MRGAS in Serbia in future is necessary to determine stability of MRGAS clones and to guide therapy strategies. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Characterization of Streptococcus pyogenes isolates responsible for adult meningitis in France from 2003 to 2013.

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    Plainvert, Céline; Doloy, Alexandra; Joubrel, Caroline; Maataoui, Naouale; Dmytruk, Nicolas; Touak, Gérald; Collobert, Gislène; Fouet, Agnès; Poyart, Claire; Loubinoux, Julien

    2016-04-01

    Sixty-three cases of Streptococcus pyogenes meningitis in adults were studied. Three predominant emm types were associated with meningitis: emm1 (44%), emm3 (11%), and emm6 (11%). Streptococcal toxic shock syndrome and mortality rates were 40% and 38%, respectively. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Controlled Human Infection for Vaccination Against Streptococcus Pyogenes

    Science.gov (United States)

    2018-03-07

    Streptococcus Pyogenes Pharyngitis; Streptococcus Pharyngitis; Strep Throat; Streptococcus Pyogenes Infection; Group A Streptococcus: B Hemolytic Pharyngitis; Group A Streptococcal Infection; Gram-Positive Bacterial Infections; Bacterial Infections

  17. Isolation of Streptococcus pyogenes in individuals with pharyngotonsillitis and antimicrobial susceptibility testing

    OpenAIRE

    Scalabrin, Rozana; Buss, Gisele D.; Iamaguchi, Kelly Cristina S.; Cardoso, Celso Luiz; Garcia, Lourdes B.

    2003-01-01

    OBJETIVO: Investigamos a ocorrência de Streptococcus pyogenes em indivíduos com faringoamigdalite que espontaneamente procuraram atendimento em farmácias e unidades de saúde. FORMA DE ESTUDO: Coorte longitudinal. MATERIAL E MÉTODOS: Com auxílio de "swab" e abaixador de língua foram coletadas amostras da orofaringe de 58 indivíduos, as quais foram semeadas por técnica de esgotamento em placas contendo ágar sangue. No momento da coleta, nenhum dos indivíduos estava sob tratamento com antibiótic...

  18. In vitro activity of josamycin against Streptococcus pyogenes isolated from patients with upper respiratory tract infections in France.

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    Auzou, M; Caillon, J; Poyart, C; Weber, P; Ploy, M-C; Leclercq, R; Cattoir, V

    2015-07-01

    The primary objective of our study was to obtain susceptibility data for josamycin against Streptococcus pyogenes isolated from patients presenting with upper respiratory tract infections in France. The secondary objective was to characterize the molecular mechanism of resistance in macrolide-resistant isolates. MICs of erythromycin, clarithromycin, azithromycin, josamycin, and clindamycin were determined by the broth microdilution method. Resistance genes erm(B), erm(TR), and mef(A) were screened by PCR. The MIC50 and MIC90 of josamycin against 193 isolates of S. pyogenes were 0.12 and 0.25mg/L, respectively, with a resistance rate estimated at 4.7%. Resistance was due to the erm(B) gene whereas strains harboring erm(TR) or mef(A) remained susceptible. Josamycin was active against >95% of S. pyogenes isolated from patients with upper respiratory tract infections, and can be used as an alternative for the treatment of pharyngitis. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. High Prevalence of Macrolide-resistance and Molecular Characterization of Streptococcus pyogenes Isolates Circulating in China from 2009 to 2016

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    Lu, Binghuai; Fang, Yujie; Fan, Yanyan; Chen, Xingchun; Wang, Junrui; Zeng, Ji; Li, Yi; Zhang, Zhijun; Huang, Lei; Li, Hongxia; Li, Dong; Zhu, Fengxia; Cui, Yanchao; Wang, Duochun

    2017-01-01

    Streptococcus pyogenes, or group A Streptococcus, is a pathogen responsible for a wide range of clinical manifestations, from mild skin and soft tissue infections and pharyngitis to severe diseases. Its epidemiological characteristics should be comprehensively under surveillance for regulating the national prevention and treatment practice. Herein, a total of 140 S. pyogenes, including 38 invasive and 102 noninvasive isolates, were collected from infected patients in 10 tertiary general hospitals from 7 cities/provinces in China during the years 2009–2016. All strains were characterized by classical and molecular techniques for its emm types/subtypes, virulent factors and antibiotic resistance profiling. Of 140 isolates, 15 distinct emm types and 31 subtypes were detected, dominated by emm12 (60 isolates, 42.9%), emm1(43, 30.7%), and emm89 (10, 7.1%), and 8 new emm variant subtypes were identified. All strains, invasive or not, harbored the superantigenic genes, speB and slo. The other virulence genes, smeZ, speF, and speC accounted for 96.4, 91.4, and 87.1% of collected isolates, respectively. Further multilocus sequence typing (MLST) placed all strains into 22 individual sequence types (STs), including 4 newly-identified STs (11, 7.9%). All isolates were phenotypically susceptible to penicillin, ampicillin, cefotaxime, and vancomycin, whereas 131(93.5%), 132(94.2%), and 121(86.4%) were resistant to erythromycin, clindamycin, and tetracycline, respectively. Our study highlights high genotypic diversity and high prevalence of macrolide resistance of S. pyogenes among clinical isolates circulating in China. PMID:28642756

  20. In Vitro Activity of Antimicrobial Agents Against Streptococcus Pyogenes Isolates from patients with Acute Tonsillopharyngitis in Dakar, Senegal

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    A. Gueye Ndiaye

    2009-06-01

    Full Text Available Streptococcus pyogenes (S. pyogenes is the most important causative agent of tonsillopharyngitis. Beta-lactam antibiotics, particularly penicillin, are the drug of first choice and macrolides are recommended for patients who are allergic to penicillin. However, other antibiotics are also used for the treatment of streptococcal tonsillopharyngitis. In recent years, the increase in the incidence of respiratory tract pathogens that are resistant to current antibacterial agents highlights the need to monitor the evolution of the resistance of these pathogens to antibiotics. In this study, we assess the susceptibility of 98 isolates of S. pyogenes to 16 antibiotics. The pathogens were recovered from patients with acute tonsillopharyngitis in Dakar, the Senegalese capital city, who were recruited from May 2005 to August 2006. All strains were susceptible to penicillin with low Minimum Inhibitory Concentration (MIC = 0,016 mg/L. Amoxicillin had high activity (100% showing its importance in treatment of streptococcal infections. Cephalosporins had MIC90 values ranging from 0.016 to 0.094 mg/L. Macrolides have shown high activity. All strains were resistant to tetracyclin. Other molecules such as teicoplanin, levofloxacin and chloramphenicol were also active and would represent alternatives to treatment of tonsillopharyngitis due to this pathogen. These results indicate that no significant resistance to antibiotics was found among patients with tonsillopharyngitis studied in Dakar. Limitations of this study were that the number of isolates tested was small and all isolates were collected from one hospital in Dakar. Hence, results may not be representative of the isolates found, in the wider community or other regions of Senegal. Further studies are needed in other parts of Dakar and other geographic regions of Senegal, in order to better clarify the antibiotic susceptibility profile of S. pyogenes isolates recovered from patients with tonsillopharyngitis.

  1. Molecular Characteristics of Erythromycin-Resistant Streptococcus pyogenes Strains Isolated from Children Patients in Tunis, Tunisia.

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    Ksia, Sonia; Smaoui, Hanen; Hraoui, Manel; Bouafsoun, Aida; Boutiba-Ben Boubaker, Ihem; Kechrid, Amel

    2017-07-01

    The aims of our study were to characterize phenotypically and genotypically erythromycin-resistant Streptococcus pyogenes or group A streptococci (ERGAS) isolates, to evaluate macrolide resistance and to analyze the association between emm types and virulence factors. Included in this study were all ERGAS strains isolated from 2000 to 2013 at the Children's hospital of Tunis. Antimicrobial susceptibility was performed according to the CA-SFM guidelines. Macrolide resistance genes were revealed by polymerase chain reaction (PCR) method. Virulence factor genes (pyrogenic exotoxin genes and superantigen gene) were detected by PCR, and the emm types were defined by the sequencing of the variable 5' end of the emm gene. Among the 289 GAS isolates collected, 15 (5.2%) were resistant to erythromycin; 7 of the strains were assigned to the cMLS B phenotype (46.6%); 5 harbored ermB gene alone (33.3%); and 2 strains coharbored ermB and mefA (13.3%). The remaining (53.4%) were assigned to the M phenotype and harbored the mefA gene. The frequency of detection of each toxin gene among ERGAS was 13.4% for speA (2 strains), 53.4% for speC (8 strains), and 13.4% for ssa (2 strains). Emm types 1, 58, 11, and 78 were the most frequent among ERGAS strains. The distribution of the cMLS B and M phenotypes changed over the period of investigation with a decrement of cMLS B phenotype and ermB gene that predominated between 2000 and 2006 and an increase of M phenotype and mefA gene between 2007 and 2013, but this difference was nonstatistically significant because of the low number of resistant strains. Emm types 1, 58, and 4 were only present among strains assigned to the M phenotype. However strains assigned to the cMLS B phenotype were associated to emm11, emm22, emm28, emm78, or emm76. There was diversity in emm distribution in ERGAS between the two study periods. There was diversity in emm distribution among ERGAS particularly in 2000-2006. Indeed, from 2000 to 2006, the 6 ERGAS

  2. Isolamento de Streptococcus pyogenes em indivíduos com faringoamigdalite e teste de susceptibilidade a antimicrobianos Isolation of Streptococcus pyogenes in individuals with pharyngotonsillitis and antimicrobial susceptibility testing

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    Rozana Scalabrin

    2003-12-01

    collected, none of the individuals was under treatment with antibiotics. The presumptive identification of S. pyogenes was made by the susceptibility test to bacitracin and confirmed by the serological grouping through the extraction of the group-specific carbohydrate "C" antigen. RESULTS: From the 58 samples of oropharynx analyzed, 32 (55.2% were from individuals assisted in drugstores and 26 (44.8% were obtained from those that sought health units. A total of 15 (25.9% samples presented positive culture for S. pyogenes, being most of the strains (9/15, 60% coming from individuals assisted in drugstores. Streptococcus pyogenes was isolated in 33.3% (11/33 of the individuals from zero to 15 years of age and in 16% (4/25 of those over 15. The strains were susceptible to all the antimicrobial agents tested. CONCLUSION: The results of the present study emphasize the importance of the bacteriological diagnosis in the proper treatment for the streptococcal pharyngotonsillitis that determine the prevention of the supurative or non supurative complications and the eradication of the microorganism of the oropharynx.

  3. Isolation of Streptococcus pyogenes from children with pharyngitis and emm type analysis.

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    Khosravi, Azar D; Ebrahimifard, Nasim; Shamsizadeh, Ahmad; Shoja, Saeed

    2016-05-01

    The group A streptococcus (GAS) M protein, encoded by the emm gene, acts as a major virulence factor. Emm-typing is the GAS gold standard molecular typing and is based on the DNA sequence of the nucleotides of the emm gene. The aim of the present study was to isolate GAS from patients and to detect the emm types of the isolates using emm typing. A total of 1000 throat samples were collected from patients with pharyngitis referred to Aboozar Children's Hospital in Ahvaz, Iran. We performed antimicrobial susceptibility testing on all isolates using the Kirby-Bauer disk diffusion method. Additionally, amplification of the emm gene was performed using polymerase chain reaction using the standard primers and described protocol. From all throat samples screened, 25 isolates (2.5%) were identified as GAS. Antibiotic susceptibility testing revealed that all the GAS isolates were susceptible to penicillin and erythromycin, but 44% showed resistance to vancomycin. Based on polymerase chain reaction for the emm gene, the obtained emm types were: emm-3, observed in 20 isolates (80%); emm-1 observed in four isolates (16%); and emm-75 observed in one isolate (4%). The result of the present study showed that penicillin and erythromycin are still the most effective antibiotics against the organism. The emm typing revealed that emm type-3 was detected in most of the isolates from patients with purulent pharyngitis. On the basis of the findings of this study, we may conclude that emm typing provides new insights on the genetic diversity of the M proteins, and is of demonstrable value for molecular studies of GAS. Copyright © 2016. Published by Elsevier Taiwan LLC.

  4. Biofilm Formation Enhances Fomite Survival of Streptococcus pneumoniae and Streptococcus pyogenes

    OpenAIRE

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

    2014-01-01

    Both Streptococcus pyogenes and Streptococcus pneumoniae are widely thought to rapidly die outside the human host, losing infectivity following desiccation in the environment. However, to date, all literature investigating the infectivity of desiccated streptococci has used broth-grown, planktonic populations. In this study, we examined the impact of biofilm formation on environmental survival of clinical and laboratory isolates of S. pyogenes and S. pneumoniae as both organisms are thought t...

  5. Streptococcus pyogenes toxic-shock syndrome

    OpenAIRE

    Antunes, R; Diogo, M; Carvalho, A; Pimentel, T; Oliveira, J

    2011-01-01

    Recently there has been an exponential increase in invasive infections caused by Streptococcus ß hemolyticcus group A. In about one third of cases they are complicated by toxic shock syndrome, characterized by septic shock and multiorgan failure. The authors, by their rarity, report a case of bacteraemia caused by Streptococcus pyogenes complicated by toxic shock syndrome.

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

    Science.gov (United States)

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

    2016-07-22

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

  7. Streptococcus pyogenes translocates across an epithelial barrier.

    Science.gov (United States)

    Sumitomo, Tomoko

    2017-01-01

    Streptococcus pyogenes is a β-hemolytic organism responsible for a wide variety of human diseases that commonly occur as self-limiting purulent diseases of the pharynx and skin. Although the occurrence of invasive infections by S. pyogenes is rare, mortality rates remain high even with progressive medical therapy. As a prerequisite for causing the severe invasive disease, S. pyogenes must invade underlying sterile tissues by translocating across the epithelial barrier. In this study, streptolysin S and SpeB were identified as the novel factors that facilitate bacterial translocation via degradation of intercellular junctions. Furthermore, we found that S. pyogenes exploits host plasminogen for acceleration of bacterial invasion into deeper tissues via tricellular tight junctions. Here, I would like to show our study on bacterial translocation across the epithelial barrier through paracellular route.

  8. (Roxb) Schltr Extract against Streptococcus pyogenes

    African Journals Online (AJOL)

    Purpose: To determine the anti-Streptococcus pyogenes activity of the chloroform extract of Boesenbergia pandurata (Roxb.) Schltr. (Zingiberaceae) and investigate its possible antibacterial mechanisms of action. Methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were ...

  9. Sensibilidad antimicrobiana y caracterización de cepas de Streptococcus pyogenes aisladas de un brote de escarlatina Antimicrobial sensitivity and typing of Streptococcus pyogenes strains isolated during a scarlet fever outbreak

    Directory of Open Access Journals (Sweden)

    Alberto González Pedraza-Avilés

    2002-09-01

    Full Text Available Objetivo. Evaluar la actividad in vitro de 13 antibióticos contra 47 Streptococcus pyogenes grupo A (SGA. Determinar la presencia de genes que codifican para exotoxina pirogénica estreptocóccica A (SpeA y serotipos con base en proteína M. Material y métodos. Estudio transversal hecho en el Centro de Salud Dr. José Castro Villagrana sobre un brote de escarlatina en el Colegio Espíritu de América, entre diciembre de 1999 y enero de 2000. El número de niños estudiados fue 137. Se extrajeron porcentajes de sensibilidad. La concentración inhibitoria mínima (CIM se obtuvo por microdilución semiautomatizada. Se utilizó un secuenciador automatizado de DNA para el análisis de variación de secuencias en los genes que codifican para proteína M y SpeA. Resultados. Todas las cepas fueron sensibles a beta-lactámicos y clindamicina; 12.7% fueron resistentes a eritromicina. El serotipo M2 fue el más frecuente, 27 del total. Prácticamente todas las bacterias (96% con el gen SpeA tienen el gen que codifica para el serotipo M2. Conclusiones. Debido a la reciente reaparición de infecciones por SGA se sugiere realizar estudios tanto de sensibilidad a macrólidos y beta-lactámicos, como de epidemiología molecular.Objective. To evaluate the in vitro activities of 13 antimicrobial agents against 47 group A Streptococcus pyogenes (GAS strains, and to determine the presence of genes encoding streptococcal pyrogenic exotoxin A (SpeA and the M--protein serotypes. Materials and Methods. A cross-sectional study was conducted at Centro de Salud Dr. José Castro Villagrana, during a scarlet fever outbreak occurring between December 1999 and January 2000, among 137 children at Colegio Espíritu de América. Minimum Inhibitory Concentrations (MICs were obtained by the semiautomated microdilution method. Automated DNA sequencing was used for analysis of sequence variation in genes encoding the M protein, and SpeA. Results. All strains were sensitive to

  10. NEPHRITOGENIC ACTIVITY OF STREPTOCOCCUS PYOGENES emm1 AND emm12 GENOTYPES ISOLATED FROM PATIENTS AND ASYMPTOMATIC CARRIERS

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    L. A. Burova

    2015-01-01

    Full Text Available In this paper the nephritogenic activity of Streptococcus pyogenes genotype emm1 and emm12 clinical isolates from scarlet fever patients and healthy children was considered. As earlier established, strains of these types differ in Fc-binding profile, interacting with native IgG and immune complexes (IC, respectively. As expected, all the type emm1 strains bound native IgG; besides, ICs interacted only with strains from patients but not with those from carriers. In contrast, all type emm12 strains appeared to be negative for native IgG, whereas ICs were bound by strains from patients exclusively. None of the tested strains bound IgG3. By immunization of rabbits, binding of native IgG as well as ICs was associated with increasing of anti-IgG antibodies titer, formation of ICs, «crescent» deposition of IgG and C3-complement, local production of the proinflammatory cytokine TNFα, аnd also with accumulation of lymphocytes in kidney tissue. These signs indicated immune inflammation, leading to experimental membrane-proliferative glomerulonephritis (PSGN. It is known that PSGN development depends on IC-binding by tissue FcγR, on complement activation as well as on tissue infiltration by macrophages/monocytes. According to the data of morphometric evaluation the nephritogenic activity of the type emm12 strains exceeded those of type emm1. On testing of three IC-binding emm12 strains in six rabbits, typical PSGN developed in 5 of them and an abortive process in 1 animal. In case of five IgG-binding type emm1 strains, out of ten rabbits full-blown PSGN was observed only in 3 of them, but abortive changes in 5 and negative result in 2 animals. No pathologic changes were elicited by the «carrier» strains of either genotype; the inability of these to bind ICs, according to literature data, could be explained by mutation in the Mga-regulator gene thereby impeding M-proteins synthesis. We conclude that isolation of type emm12 IC-binding strains at acute

  11. Virulence gene pool detected in bovine group C Streptococcus dysgalactiae subsp. dysgalactiae isolates by use of a group A S. pyogenes virulence microarray.

    Science.gov (United States)

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

    2011-07-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

  13. Factors that cause trimethoprim resistance in Streptococcus pyogenes.

    Science.gov (United States)

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

    2014-01-01

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

  14. Isolation of Streptococcus pyogenes from children with pharyngitis and emm type analysis

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    Azar D. Khosravi

    2016-05-01

    Conclusion: The result of the present study showed that penicillin and erythromycin are still the most effective antibiotics against the organism. The emm typing revealed that emm type-3 was detected in most of the isolates from patients with purulent pharyngitis. On the basis of the findings of this study, we may conclude that emm typing provides new insights on the genetic diversity of the M proteins, and is of demonstrable value for molecular studies of GAS.

  15. Novel Regulatory Small RNAs in Streptococcus pyogenes

    Science.gov (United States)

    Tesorero, Rafael A.; Yu, Ning; Wright, Jordan O.; Svencionis, Juan P.; Cheng, Qiang; Kim, Jeong-Ho; Cho, Kyu Hong

    2013-01-01

    Streptococcus pyogenes (Group A Streptococcus or GAS) is a Gram-positive bacterial pathogen that has shown complex modes of regulation of its virulence factors to cause diverse diseases. Bacterial small RNAs are regarded as novel widespread regulators of gene expression in response to environmental signals. Recent studies have revealed that several small RNAs (sRNAs) have an important role in S. pyogenes physiology and pathogenesis by regulating gene expression at the translational level. To search for new sRNAs in S. pyogenes, we performed a genomewide analysis through computational prediction followed by experimental verification. To overcome the limitation of low accuracy in computational prediction, we employed a combination of three different computational algorithms (sRNAPredict, eQRNA and RNAz). A total of 45 candidates were chosen based on the computational analysis, and their transcription was analyzed by reverse-transcriptase PCR and Northern blot. Through this process, we discovered 7 putative novel trans-acting sRNAs. Their abundance varied between different growth phases, suggesting that their expression is influenced by environmental or internal signals. Further, to screen target mRNAs of an sRNA, we employed differential RNA sequencing analysis. This study provides a significant resource for future study of small RNAs and their roles in physiology and pathogenesis of S. pyogenes. PMID:23762235

  16. Characterization of Streptococcus pyogenes from Animal Clinical Specimens, Spain.

    Science.gov (United States)

    Vela, Ana Isabel; Villalón, Pilar; Sáez-Nieto, Juan Antonio; Chacón, Gema; Domínguez, Lucas; Fernández-Garayzábal, José Francisco

    2017-12-01

    Streptococcus pyogenes appears to be almost exclusively restricted to humans, with few reports on isolation from animals. We provide a detailed characterization (emm typing, pulsed-field gel electrophoresis [PFGE], and multilocus sequence typing [MLST]) of 15 S. pyogenes isolates from animals associated with different clinical backgrounds. We also investigated erythromycin resistance mechanisms and phenotypes and virulence genes. We observed 2 emm types: emm12 (11 isolates) and emm77 (4 isolates). Similarly, we observed 2 genetic linages, sequence type (ST) 26 and ST63. Most isolates exhibited the M macrolide resistance phenotype and the mefA/ermB genotype. Isolates were grouped into 2 clones on the basis of emm-MLST-PFGE-virulence gene profile combinations: clone 1, characterized by the combined genotype emm12-ST36-pulsotype A-speG; and clone 2, characterized by the genotype emm77-ST63-pulsotype B-speC. Our results do not show conclusively that animals may represent a new reservoir of S. pyogenes but indicate the ability of human-derived S. pyogenes isolates to colonize and infect animals.

  17. Conjugative transfer of the erm(A) gene from erythromycin-resistant Streptococcus pyogenes to macrolide-susceptible S. pyogenes, Enterococcus faecalis and Listeria innocua.

    Science.gov (United States)

    Giovanetti, E; Magi, G; Brenciani, A; Spinaci, C; Lupidi, R; Facinelli, B; Varaldo, P E

    2002-08-01

    In mating experiments, the erythromycin resistance methylase gene erm(A) was successfully transferred from erm(A)-positive clinical isolates of Streptococcus pyogenes to macrolide-susceptible recipients of S. pyogenes, Enterococcus faecalis and Listeria innocua. Compared with the SmaI macrorestriction pattern of the S. pyogenes recipient, the patterns of S. pyogenes transconjugants shared the lack of a fragment and the appearance of a new, larger fragment. This is the first experimental evidence that the erm(A) gene can be transferred from erythromycin-resistant S. pyogenes to macrolide-susceptible S. pyogenes as well as to other Gram-positive recipients.

  18. Carrying pharyngeal of Streptococcus pyogenes and sensitivity profiles in schoolchild from Cartagena

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    Lucy Margarita Villafañe-Ferrer

    2015-07-01

    Full Text Available To determine the frequency of carrying pharyngeal of Streptococcus pyogenes and their sensitivity profiles in schoolchildren from Cartagena. Analytical cross-sectional study, the sample was composed by 131 children. Strains of Streptococcus pyogenes were identified using conventional methods. Antibiotic sensitivity was determined the Kirby-Bauer methods. A questionnaire was applied in order to identify risk factors associated.19,8% of children were carriers of bacterium. 26 isolates of Streptococcus pyogenes were obtained. To evaluate the sensitivity were found strains sensible to ceftriaxone and erytrhomycin (84,6% each one. 23,1% (6/26 0f isolates were resistant to ampicillin. It not was found association between carrying pharyngeal of Streptococcus pyogenes and risk factors (p>0,05. It were found resistant strains to antibiotics considered of first election for therapy of infectious diseases produced by this bacterium.

  19. Acanthamoeba castellanii interactions with Streptococcus pneumoniae and Streptococcus pyogenes.

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Yee Ong, Timothy Yu; Jung, Suk Yul; Khan, Naveed Ahmed

    2017-12-01

    Among the genus Streptococcus, S. pyogenes and S. pneumoniae are the major causes of pharyngitis, impetigo, pneumonia and meningitis in humans. Streptococcus spp. are facultative anaerobes that are nutritionally fastidious, yet survive in the environment and target the predisposed population. Antibacterial disinfectants have been partially effective only, indicating the need for novel preventative measures and to understand mechanisms of bacterial resistance. Acanthamoeba is a free-living protist that is known to harbour microbial pathogens, provide shelter, and assist in their transmission to susceptible population. The overall aim of this study was to determine whether S. pyogenes and S. pneumoniae can interact with A. castellanii by associating, invading, and surviving inside trophozoites and cysts. It was observed that both S. pyogenes and S. pneumoniae were able to associate as well as invade and/or taken up by the phagocytic A. castellanii trophozoite. Notably, S. pyogenes and S. pneumoniae survived the encystation process, avoided phagocytosis, multiplied, and exhibited higher recovery from the mature cysts, compared with the trophozoite stage (approximately 2 bacteria per amoebae ratio for cyst stage versus 0.02 bacteria per amoeba ration for trophozoite stage). As Acanthamoeba cysts are resilient and can disperse through the air, A. castellanii can act as a vector in providing shelter, facilitating growth and possibly genetic exchanges. In addition, these interactions may contribute to S. pyogenes and S. pneumoniae survival in harsh environments, and transmission to susceptible population and possibly affecting their virulence. Future studies will determine the molecular mechanisms associated with Acanthamoeba interactions with Streptococcus and the evolution of pathogenic bacteria and in turn expedite the discovery of novel therapeutic and/or preventative measures. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Tristan Lefébure

    Full Text Available 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.

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2014-04-01

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

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

    Science.gov (United States)

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

    2015-07-01

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

  5. Thermoregulation of Capsule Production by Streptococcus pyogenes

    Science.gov (United States)

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

    2012-01-01

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

  6. Evolutionary Constraints Shaping Streptococcus pyogenes-Host Interactions.

    Science.gov (United States)

    Wilkening, Reid V; Federle, Michael J

    2017-07-01

    Research on the Gram-positive human-restricted pathogen Streptococcus pyogenes (Group A Streptococcus, GAS) has long focused on invasive illness, the most severe manifestations of GAS infection. Recent advances in descriptions of molecular mechanisms of GAS virulence, coupled with massive sequencing efforts to isolate genomes, have allowed the field to better understand the molecular and evolutionary changes leading to pandemic strains. These findings suggest that it is necessary to rethink the dogma involving GAS pathogenesis, and that the most productive avenues for research going forward may be investigations into GAS in its 'normal' habitat, the nasopharynx, and its ability to either live with its host in an asymptomatic lifestyle or as an agent of superficial infections. This review will consider these advances, focusing on the natural history of GAS, the evolution of pandemic strains, and novel roles for several key virulence factors that may allow the field to better understand their physiological role. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Recurrent bacteremia with different strains of Streptococcus pyogenes in an immunocompromised child.

    Science.gov (United States)

    Hattori, Takuya; Minami, Masaaki; Narita, Kotaro; Nakata, Tomohiko; Itomi, Seiko; Kubota, Kinya; Oya, Teruaki; Nishiyama, Hideki; Kato, Hideki; Yuasa, Norihiro

    2016-06-01

    We report an immunocompromised child who experienced two episodes of bacteremia due to Streptococcus pyogenes. Random amplification of polymorphic DNA profiles, emm genotypes, superantigen profiles, antimicrobial susceptibility, and resistance-related genes were investigated, and the results showed different profiles between the two isolates. This is the first report describing recurrent bacteremia caused by different strains of S. pyogenes. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  8. Detection of Streptococcus pyogenes virulence genes in Streptococcus dysgalactiae subsp. equisimilis from Vellore, India.

    Science.gov (United States)

    Babbar, Anshu; Itzek, Andreas; Pieper, Dietmar H; Nitsche-Schmitz, D Patric

    2018-03-12

    Streptococcus dysgalactiae subsp. equisimilis (SDSE), belonging to the group C and G streptococci, are human pathogens reported to cause clinical manifestations similar to infections caused by Streptococcus pyogenes. To scrutinize the distribution of gene coding for S. pyogenes virulence factors in SDSE, 255 isolates were collected from humans infected with SDSE in Vellore, a region in southern India, with high incidence of SDSE infections. Initial evaluation indicated SDSE isolates comprising of 82.35% group G and 17.64% group C. A multiplex PCR system was used to detect 21 gene encoding virulence-associated factors of S. pyogenes, like superantigens, DNases, proteinases, and other immune modulatory toxins. As validated by DNA sequencing of the PCR products, sequences homologous to speC, speG, speH, speI, speL, ssa and smeZ of the family of superantigen coding genes and for DNases like sdaD and sdc were detected in the SDSE collection. Furthermore, there was high abundance (48.12% in group G and 86.6% in group C SDSE) of scpA, the gene coding for C5a peptidase in these isolates. Higher abundance of S. pyogenes virulence factor genes was observed in SDSE of Lancefield group C as compared to group G, even though the incidence rates in former were lower. This study not only substantiates detection of S. pyogenes virulence factor genes in whole genome sequenced SDSE but also makes significant contribution towards the understanding of SDSE and its increasing virulence potential.

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

    Science.gov (United States)

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

    2014-05-01

    Complete characterization of a Streptococcus pyogenes population from a defined geographic region comprises information on the plasmids that circulate in these bacteria. Therefore, we determined the distribution of small plasmids (pyogenes isolates from India, where diversity of strains and incidence rates of S. pyogenes infections are high. The collection comprised 77 emm-types. For plasmid detection and discrimination, we developed PCRs for different plasmid replication initiation protein genes, the putative repressor gene copG and bacteriocin genes dysA and scnM57. Plasmid distribution was limited to 13 emm-types. Co-detection analysis using aforementioned PCRs revealed four distinct plasmid sub-types, two of which were previously unknown. Representative plasmids pA852 and pA996 of the two uncharacterized plasmid sub-types were sequenced. These two plasmids could be assigned to the pMV158 and the pC194/pUB110 family of rolling-circle plasmids, respectively. The majority of small plasmids found in India belonged to the two newly characterized sub-types, with pA852- and pA996-like plasmids amounting to 42% and 22% of all detected plasmids, respectively. None of the detected plasmids coded for a known antibiotic resistance gene. Instead, all of the four plasmid sub-types carried known or potential bacteriocin genes. These genes may have influence on the evolutionary success of certain S. pyogenes genotypes. Notably, pA852-like plasmids were found in all isolates of the most prevalent emm-type 11.0. Together, a priori fitness of this genotype and increased fitness due to the acquired plasmids may have rendered type emm11.0 successful and caused the prevalence of pA852-like plasmids in India. Copyright © 2013 Elsevier GmbH. All rights reserved.

  10. In vitro antimicrobial activity of ozenoxacin against methicillin-susceptible Staphylococcus aureus, methicillin-resistant S. aureus and Streptococcus pyogenes isolated from clinical cutaneous specimens in Japan.

    Science.gov (United States)

    Kanayama, Shoji; Ikeda, Fumiaki; Okamoto, Kazuaki; Nakajima, Akiko; Matsumoto, Tatsumi; Ishii, Ritsuko; Amano, Ayako; Matsuzaki, Kaoru; Matsumoto, Satoru

    2016-10-01

    Ozenoxacin, a novel non-fluorinated topical quinolone, was assessed for in vitro antimicrobial activity against each 50 isolates of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and Streptococcus pyogenes according to the broth microdilution method recommended by the Clinical and Laboratory Standards Institute. The isolates used in this study were recovered from cutaneous specimens of Japanese adult and pediatric patients who visited hospitals in 2014. The MIC90s of ozenoxacin against MSSA, MRSA and S. pyogenes isolates from adult patients were ≤0.06, 4 and ≤0.06 μg/mL, respectively. The MIC90s of ozenoxacin against MSSA and S. pyogenes isolates from pediatric patients were equal to those against the adult isolates. On the other hand, the MIC90s of ozenoxacin against the pediatric MRSA isolates was 0.12 μg/mL, and was 32 times lower than that against the adult isolates. The antimicrobial activity of ozenoxacin against MSSA, MRSA and S. pyogenes was equal to or greater than those of 7 reference antimicrobial agents had been used for the treatment of skin infections. The MICs of ozenoxacin was highly correlated with those of nadifloxacin and levofloxacin in the 50 MRSA isolates (r(2) = 0.906 and 0.833, respectively). However, ozenoxacin kept the potent antimicrobial activity with the MIC ranging from 1 to 4 μg/mL even against MRSA low susceptible (MIC: >64 μg/mL) to nadifloxacin or levofloxacin. Ozenoxacin could represent the first-in-class non-fluorinated quinolone for the topical treatment of various superficial skin infections caused by MSSA, MRSA and S. pyogenes. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  11. Incidencia de faringitis por Streptococcus pyogenes en Bariloche: Argentina Incidence of Streptococcus pyogenes pharyngitis in Bariloche: Argentina

    Directory of Open Access Journals (Sweden)

    G. Rubinstein

    2005-06-01

    Full Text Available Fueron evaluadas la incidencia y estacionalidad de faringitis por Streptococcus pyogenes en Bariloche, una ciudad donde las bajas temperaturas favorecen las condiciones de hacinamiento durante gran parte del año. Se analizaron 5.276 hisopados de fauces durante el período 2000-2003. Las muestras fueron sembradas en agar sangre ovina (5% e incubadas 24-48 h a 35 °C. Las colonias beta-hemolíticas fueron identificadas utilizando los métodos convencionales. Se calcularon las medias mensuales de hisopados de fauces totales, de aislamientos de S. pyogenes y de los porcentajes de faringitis por S. pyogenes. La incidencia de faringitis por este microorganismo fue superior al 24% en todos los meses del período abril-diciembre, con un máximo en noviembre (33%. El mes de menor incidencia fue febrero (13%. Se observó una tendencia creciente desde marzo a noviembre, con un leve valle en julio y un marcado descenso que se inició en diciembre y mostró valores mínimos en enero y febrero, los meses más cálidos. Este patrón estacional difiere del observado en climas templados. La incidencia fue alta durante gran parte del año, abarcando desde mediados del otoño hasta principios del verano.The incidence and seasonality of pharyngitis by S. pyogenes in Bariloche, a city were long periods of low temperatures result in extended indoor activities were studied. A total of 5276 throat swab specimens collected during 2000-2003 in the clinical microbiology laboratories of the three main medical institutions of the city, were analyzed. Samples were cultured on blood-agar media containing 5% defibrinated sheep blood, and incubated for 24-48 h at 35 °C. Strains were identified using standard procedures. Monthly means for throat swabs, S. pyogenes isolates, and percent of S. pyogenes pharyngitis, were estimated. The incidence of pharyngitis by this microorganism was greater than 24% for every month within the April-December period, reaching a maximum in

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

    Science.gov (United States)

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

    2015-10-01

    Fluoroquinolone-nonsusceptible Streptococcus pyogenes has rapidly emerged in several countries. The aim of this study was to survey the epidemiology and molecular characteristics of fluoroquinolone-nonsusceptible S. pyogenes in Taiwan. A total of 350 consecutive S. pyogenes isolates were collected between January 2005 and December 2012, including 152 (43.4%) invasive and 198 (56.6%) noninvasive isolates. Thirty-nine isolates (11.1%) of S. pyogenes were nonsusceptible to fluoroquinolones, including one emm1/ST28, 4 emm4/ST39, 33 emm12/ST36, and 1 emm87/ST62. Of all the isolates, emm12 (50%) demonstrated the highest prevalence of fluoroquinolone nonsusceptibility. Alterations of Ser79Phe and Ala12Val in ParC were the most frequently mutations in fluoroquinolone-nonsusceptible S. pyogenes isolates. There were no amino acid substitutions in GyrB, and 1 emm87 isolate exhibited 3 nonsynonymous mutations in ParE. Our study reveals the emergence of fluoroquinolone-nonsusceptible S. pyogenes emm12/ST36 in Taiwan. Regular surveillance of fluoroquinolone susceptibility in S. pyogenes is suggested. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2015-01-01

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

  14. Distribution of subclasses mefA and mefE of the mefA gene among clinical isolates of macrolide-resistant (M-phenotype) Streptococcus pneumoniae, viridans group streptococci, and Streptococcus pyogenes.

    Science.gov (United States)

    Ardanuy, Carmen; Tubau, Fe; Liñares, Josefina; Domínguez, María Angeles; Pallarés, Román; Martín, Rogelio

    2005-02-01

    The distribution of subclasses mefA and mefE of the mefA gene among 116 M-phenotype streptococci was as follows: pneumococci (38 strains had mefE and 4 mefA), viridans streptococci (49 mefE and 1 mefA), and Streptococcus pyogenes (24 mefA). Spain(9V)-3-14 and England(14)-9 clones of serotype 14 were dominant among pneumococci.

  15. Anti-Streptococcus pyogenes Activity of Selected Medicinal Plant ...

    African Journals Online (AJOL)

    Original Research Article. Anti-Streptococcus pyogenes Activity of Selected. Medicinal Plant Extracts Used in Thai Traditional Medicine. Surasak Limsuwan1 and Supayang P Voravuthikunchai2*. 1Faculty of Traditional Thai Medicine and Natural Products Research Center of Excellence, 2Department of Microbiology and.

  16. Streptococcus pyogenes: an unusual cause of salpingitis. Case report and review of the literature.

    Science.gov (United States)

    Blot, Mathieu; de Curraize, Claire; Salmon-Rousseau, Arnaud; Gehin, Sophie; Bador, Julien; Chavanet, Pascal; Neuwirth, Catherine; Piroth, Lionel; Amoureux, Lucie

    2017-10-01

    Streptococcus pyogenes can colonize genitourinary tract, but it is a rare cause of salpingitis. We report a case of bilateral salpingitis due to Streptococcus pyogenes in a 34-year-old woman using an intra-uterine device and which occurred following a family history of recurrent S. pyogenes infections. We review 12 other cases reported in the literature, and discuss the pathophysiological mechanisms of this potentially life-threatening disease. It is important to take into account consider Streptococcus pyogenes as a cause of acute salpingitis in the context of recent intra-familial Streptococcus pyogenes infections.

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

    Science.gov (United States)

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

    2014-03-01

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

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

    Science.gov (United States)

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

    2015-09-01

    Streptococcus pyogenes is an increasingly important pathogen in many parts of the world. Rapid and accurate detection of S. pyogenes aids in the control of the infection. In this study, a loop-mediated isothermal amplification (LAMP) assay was developed and validated for the specific detection of S. pyogenes. The assay incorporates two methods: a chromogenic analysis using a calcein/Mn(2+) complex and real-time turbidity monitoring to assess the reaction. Both methods detected the target DNA within 60 min under 64°C isothermal conditions. The assay used specifically designed primers to target spy1258, and correctly identified 111 strains of S. pyogenes and 32 non-S. pyogenes strains, including other species of the genus Streptococcus. Tests using reference strains showed that the LAMP assay was highly specific. The sensitivity of the assay, with a detection limit of 1.49 pg DNA, was 10-fold greater than that of PCR. The LAMP assay established in this study is simple, fast and sensitive, and does not rely upon any special equipment; thus, it could be employed in clinical diagnosis. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Science.gov (United States)

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

    2014-01-01

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

  20. Mixed Streptococcus pneumoniae and Streptococcus pyogenes meningitis in an immunocompromised adult patient: a case report.

    Science.gov (United States)

    Demerle, Clémence; Ivanov, Vadim; Mercier, Cédric; Costello, Régis; Drancourt, Michel

    2015-11-29

    Community-acquired meningitis is a monomicrobial infection caused by either viruses or bacteria in the vast majority of patients. We report here one exceptional case of a patient with mixed bacterial meningitis due to Streptococcus pneumoniae and Streptococcus pyogenes. We report the case of a 68-year-old immunocompromised Caucasian man suffering from otitis and then meningitis caused by Streptococcus pneumoniae and Streptococcus pyogenes. Bacteria were undistinguishable by direct microscopic examination of the cerebrospinal fluid. He responded well to treatment with cefotaxime and dexamethasone, with no sequelae observed at the 4-month follow-up. This first reported case of mixed S. pneumoniae and S. pyogenes meningitis illustrates the life-threatening consequences of barotrauma in immunocompromised patients suffering from otorhinolaryngeal infections.

  1. Genome Analysis of Streptococcus pyogenes Associated with Pharyngitis and Skin Infections

    Science.gov (United States)

    Ibrahim, Joe; Eisen, Jonathan A.; Jospin, Guillaume; Coil, David A.; Khazen, Georges

    2016-01-01

    Streptococcus pyogenes is a very important human pathogen, commonly associated with skin or throat infections but can also cause life-threatening situations including sepsis, streptococcal toxic shock syndrome, and necrotizing fasciitis. Various studies involving typing and molecular characterization of S. pyogenes have been published to date; however next-generation sequencing (NGS) studies provide a comprehensive collection of an organism’s genetic variation. In this study, the genomes of nine S. pyogenes isolates associated with pharyngitis and skin infection were sequenced and studied for the presence of virulence genes, resistance elements, prophages, genomic recombination, and other genomic features. Additionally, a comparative phylogenetic analysis of the isolates with global clones highlighted their possible evolutionary lineage and their site of infection. The genomes were found to also house a multitude of features including gene regulation systems, virulence factors and antimicrobial resistance mechanisms. PMID:27977735

  2. Local Th17/IgA immunity correlate with protection against intranasal infection with Streptococcus pyogenes

    DEFF Research Database (Denmark)

    Mortensen, Rasmus; Christensen, Dennis; Hansen, Lasse Bøllehuus

    2017-01-01

    Streptococcus pyogenes (group A streptococcus, GAS) is responsible for a wide array of infections. Respiratory transmission via droplets is the most common mode of transmission but it may also infect the host via other routes such as lesions in the skin. To advance the development of a future...... that locally primed immunity is important for the defense against intranasal infection with Streptococcus pyogenes....

  3. Anti-Bacterial Activity of Phenolic Compounds against Streptococcus pyogenes

    DEFF Research Database (Denmark)

    Macé, Sabrina; Hansen, Lisbeth Truelstrup; P. Vasantha Rupasinghe, H.

    2017-01-01

    Background: Worldwide, Streptococcus pyogenes is the leading cause of bacterial pharyngitis. To reduce the use of antibiotics, antimicrobial phytochemical-containing remedies, which have long been in use in traditional medicine, may provide new approaches for management of streptococcal pharyngitis....... The objective of this study was to assess the inhibitory activities of 25 natural phenolic compounds against three strains of S. pyogenes. Methods: After an initial screening, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the nine most effective phenolic compounds...... were determined. The effect of four compounds with the lowest MIC and MBC on streptococcal growth and biofilm formation was also studied. Results: 1,2-Naphthoquinone and 5-hydroxy-1,4-naphthoquinone elicited the greatest anti-S. pyogenes activities with MICs ranging from 0.39 to 6.25 µg mL−1 and MBCs...

  4. In Vitro Antibacterial Activity of Essential Oils against Streptococcus pyogenes

    Directory of Open Access Journals (Sweden)

    Julien Sfeir

    2013-01-01

    Full Text Available 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.

  5. CodY-mediated regulation of Streptococcus pyogenes exoproteins

    Directory of Open Access Journals (Sweden)

    McDowell Emily J

    2012-06-01

    Full Text Available Abstract Background The production of Streptococcus pyogenes exoproteins, many of which contribute to virulence, is regulated in response to nutrient availability. CodY is a transcriptional regulator that controls gene expression in response to amino acid availability. The purpose of this study was to identify differences in the expression of streptococcal exoproteins associated with deletion of the codY gene. Results We compared the secreted proteins produced by wild-type S. pyogenes to a codY mutant in the post-exponential phase of growth. We used both one and two-dimensional gel electrophoresis to separate exoproteins. Proteins that were significantly different in abundance upon repeated analysis were identified with tandem mass spectrometry. The production of the secreted cysteine protease SpeB, a secreted chromosomally encoded nuclease (SdaB, and a putative adhesion factor (Spy49_0549 were more abundant in supernatant fluids obtained from the codY mutant. In addition, hyaluronidase (HylA, CAMP factor (Cfa, a prophage encoded nuclease (Spd-3, and an uncharacterized extracellular protein (Spy49_0015 were less abundant in supernatant fluids obtained from the codY mutant strain. Enzymatic assays showed greater DNase activity in culture supernatants isolated in the post-exponential phase of growth from the codY mutant strain compared to the wild-type strain. Because extracellular nucleases and proteases can influence biofilm formation, we also measured the ability of the strains to form biofilms during growth with both rich medium (Todd Hewitt yeast extract; THY and chemically defined media (CDM. No difference was observed with rich media but with CDM the biofilms formed by the codY mutant strain had less biomass compared to the wild-type strain. Conclusions Overall, the results indicate that CodY alters the abundance of a select group of S. pyogenes exoproteins, including DNases, a protease, and hylauronidase, which together may alleviate

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

    Science.gov (United States)

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

    2016-04-01

    Despite over a century of research and the careful scrutiny of many promising targets, there is currently no vaccine available for the prevention of Streptococcus pyogenes infection. Through analysis of the protective, anti-streptococcal components of pooled human immunoglobulin, we previously identified ten highly conserved and invariant S. pyogenes antigens that contribute to anti-streptococcal immunity in the adult population. We sought to emulate population immunity to S. pyogenes through a process of active vaccination, using the antigens targeted by pooled human immunoglobulin. Seven targets were produced recombinantly and mixed to form a multicomponent vaccine (Spy7). Vaccinated mice were challenged with S. pyogenes isolates representing four globally relevant serotypes (M1, M3, M12 and M89) using an established model of invasive disease. Vaccination with Spy7 stimulated the production of anti-streptococcal antibodies, and limited systemic dissemination of M1 and M3 S. pyogenes from an intramuscular infection focus. Vaccination additionally attenuated disease severity due to M1 S. pyogenes as evidenced by reduction in weight loss, and modulated cytokine release. Spy7 vaccination successfully stimulated the generation of protective anti-streptococcal immunity in vivo. Identification of reactive antigens using pooled human immunoglobulin may represent a novel route to vaccine discovery for extracellular bacteria. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    Science.gov (United States)

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

    2016-06-03

    Streptococcus pyogenes is an important global pathogen, causing considerable morbidity and mortality, especially in low and middle income countries where rheumatic heart disease and invasive infections are common. There is a number of promising vaccine candidates, most notably those based on the M protein, the key virulence factor for the bacterium. Vaccines against Streptococcus pyogenes are considered as impeded vaccines because of a number of crucial barriers to development. Considerable effort is needed by key players to bring current vaccine candidates through phase III clinical trials and there is a clear need to develop a roadmap for future development of current and new candidates. Copyright © 2016 World Health Organization. Published by Elsevier Ltd.. All rights reserved.

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

    Science.gov (United States)

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

    2016-07-01

    Efflux-mediated macrolide resistance due to mef(E) and mel, carried by the mega element, is common in Streptococcus pneumoniae, for which it was originally characterized, but it is rare in Streptococcus pyogenes In S. pyogenes, mega was previously found to be enclosed in Tn2009, a composite genetic element of the Tn916 family containing tet(M) and conferring erythromycin and tetracycline resistance. In this study, S. pyogenes isolates containing mef(E), apparently not associated with other resistance determinants, were examined to characterize the genetic context of mega. By whole-genome sequencing of one isolate, MB56Spyo009, we identified a novel composite integrative and conjugative element (ICE) carrying mega, designated ICESpy009, belonging to the ICESa2603 family. ICESpy009 was 55 kb long, contained 61 putative open reading frames (ORFs), and was found to be integrated into hylA, a novel integration site for the ICESa2603 family. The modular organization of the ICE was similar to that of members of the ICESa2603 family carried by different streptococcal species. In addition, a novel cluster of accessory resistance genes was found inside a region that encloses mega. PCR mapping targeting ICESpy009 revealed the presence of a similar ICE in five other isolates under study. While in three isolates the integration site was the same as that of ICESpy009, in two isolates the ICE was integrated into rplL, the typical integration site of the ICESa2603 family. ICESpy009 was able to transfer macrolide resistance by conjugation to both S. pyogenes and S. pneumoniae, showing the first evidence of the transferability of mega from S. pyogenes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

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

    Science.gov (United States)

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

    2018-02-01

    Streptococcus pyogenes or Group A Streptococci (GAS) cause many infections in infancy. Changes in its epidemiology have been described in recent years, including an increase in invasive infections (iGAS). A retrospective-descriptive study was conducted on children less than 15 years old, with GAS infections, in particular iGAS, and their complications from February 2004-April 2014. A total of 2,192 positive cultures were obtained of which 92.7% were pharyngeal cultures. Twenty-nine patients were admitted to hospital: 4 with suppurative complications, 7 post-infective, 14 iGAS, and 4 probable iGAS cases. There were no differences in the frequency of GAS isolations/year. Non-invasive isolates were more frequent in winter and spring (P<.001), and 68.3% were in patients younger than 5 years. The incidence of iGAS was 2.1/100,000 children/year. There was no seasonality, and it was more frequent in younger children (P=.039). The most common diagnosis was pneumonia (6/14). Eight patients required intensive care. They were treated empirically with second or third-generation cephalosporin or with intravenous penicillin, and pneumonia required longer treatment times (P=.016). All GAS isolates were sensitive to penicillin, and 10.6% were resistant to erythromycin. The time spent in hospital was longer for iGAS than other cases (P=.028). No patients died. Pharyngotonsillitis caused by GAS is common in childhood, and its incidence is increasing in children younger than 5 years. At the moment, post-infectious complications are rare. Invasive infections are the most severe forms of presentation, and are more common in younger children. Copyright © 2016 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Streptococcus pyogenes as the cause of vulvovaginitis and balanitis in children.

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    Randjelovic, Gordana; Otasevic, Suzana; Mladenovic-Antic, Snezana; Mladenovic, Vesna; Radovanovic-Velickovic, Radmila; Randjelovic, Marina; Bogdanovic, Dragan

    2017-04-01

    Streptococcus pyogenes (group A Streptococcus) is the etiological agent of perineal infection in children, consisting of perianal infection, vulvovaginitis and balanitis. If it is not properly diagnosed and treated, it can persist for many months and can cause severe complications. Furthermore, treatment with penicillin can be followed by failures and recurrences. We report here the prevalence of S. pyogenes isolates in genital tract specimens from girls (n = 1692) with symptoms of vulvovaginitis and from boys (n = 52) with balanitis in the municipality of Nis, Southeast-Serbia (the Western Balkans) in a 10 year period, and the seasonal distribution, patient age and sensitivity to bacitracin and antimicrobial drugs used in the treatment of streptococcal infection. Streptococcal vulvovaginitis was diagnosed in 2.30% of examinees. Of those cases, 64.10% were detected from April to September, and it was most common (71.79%) in girls aged 3-7 years. Streptococcal balanitis was diagnosed in two instances: in a 4-year-old boy and in a 7-year-old boy. S. pyogenes strains resistant to bacitracin were identified in five girls. Two isolates with M phenotype and five isolates with cMLS B phenotype were identified. Streptococcal vulvovaginitis was diagnosed less often in the present study, but it was still far more common than streptococcal balanitis in childhood. Bacitracin resistance of S. pyogenes strains should be taken into account in routine microbiological identification, and the detection of S. pyogenes isolates resistant to erythromycin requires surveillance in the present geographical territory. © 2016 Japan Pediatric Society.

  11. Delineation of Streptococcus dysgalactiae, its subspecies, and its clinical and phylogenetic relationship to Streptococcus pyogenes.

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    Jensen, Anders; Kilian, Mogens

    2012-01-01

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

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

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    Jensen, Anders

    2012-01-01

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

  13. Non-invasive monitoring of Streptococcus pyogenes vaccine efficacy using biophotonic imaging.

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    Faraz M Alam

    Full Text Available 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 10(5 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.

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

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

    2013-01-01

    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

  15. Invasive disease by Streptococcus pyogenes: patients hospitalized for 6 years.

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    Arias-Constantí, Vanessa; Trenchs-Sainz de la Maza, Victoria; Sanz-Marcos, Nuria Elvira; Guitart-Pardellans, Carmina; Gené-Giralt, Amadeu; Luaces-Cubells, Carles

    2017-07-10

    The last years an increase of severe cases of invasive disease (ID) due to Streptococcus pyogenes or streptococcus b-hemolytic group A (SGA) had been detected. The aim of this study was to analyze the epidemiology and the clinical features of ID due to SGA in a tertiary Pediatric Hospital. Retrospective study in a Pediatric hospital, of all in-patients with final diagnosis of ID due to SGA during 6 years (2009-2014). To consider ID, SGA had to be isolated in sterile samples; in patients with fascitis necroticans in skin samples or in any sample in patients with the diagnostic of Streptococcal Toxic Shock Syndrome (STSS). The SSTS was defined as hypotension and at least 2 of these criteria: renal failure, hepatic failure, acute respiratory distress, tissue necrosis or desquamative erythematous rash. Demographic data, type of infection, risk factors, clinical presentation, analytical data at admission, treatment, need for admission to a pediatric intensive care unit, microbiological data, hospital stay and evolution were collected. Fifty-two (52) cases were included (12/10,000 of all inpatients); 3 years-old was the medium age (p25-75: 1.4-6.9 years); 28 (53.8%) were boys. Fourteen patients (26.9%) had risk factors. Fever was the major symptom (51 patients, 98.1%). The skin lesions were the most frequent clinical manifestations found (21; 40.4%). In 50 (96%) cases, SGA was isolated in at least one sterile sample. Skin and soft tissue infections were diagnosed in 14 patients (26.9%), 14 (26.9%) pneumonias, 12 (23.1%) bones and joints infections, 10 (19.2%) SSTS, 6 (11.5%) occult bacteremia, 4 (7.7%) meningitis and 2 (3.8%) sepsis. Surgery was required in 18 cases (34.6%) and 17 patients (32.7%) needed intensive care. The medium hospital stay was 9.5 days (p25-75: 8-15 days). Three patients presented sequels and one patient died. The ID due to SGA was a rare but serious reason for hospital admission. Skin and soft tissue infections, and pleuroneumonia were the most

  16. Identification and cluster analysis of Streptococcus pyogenes by MALDI-TOF mass spectrometry.

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    Jie Wang

    Full Text Available BACKGROUND: Whole-cell matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF mass spectrometry (MS has been successfully applied for bacterial identification and typing of many pathogens. The fast and reliable qualities of MALDI-TOF MS make it suitable for clinical diagnostics. MALDI-TOF MS for the identification and cluster analysis of Streptococcus pyogenes, however, has not been reported. The goal of our study was to evaluate this approach for the rapid identification and typing of S. pyogenes. METHODS: 65 S. pyogenes isolates were obtained from the hospital. The samples were prepared and MALDI-TOF MS measurements were conducted as previously reported. Identification of unknown spectra was performed via a pattern recognition algorithm with a reference spectra and a dendrogram was constructed using the statistical toolbox in Matlab 7.1 integrated in the MALDI Biotyper 2.0 software. RESULTS: For identification, 61 of 65 S. pyogenes isolates could be identified correctly by MALDI-TOF MS with BioType 2.0 when compared to biochemical identification (API Strep, with an accuracy of 93.85%. In clustering analysis, 44 of 65 isolates were in accordance with those established by M typing, with a matching rate of 67.69%. When only the M type prevalence in China was considered, 41 of 45 isolates were in agreement with M typing, with a matching rate of 91.1%. CONCLUSIONS: It was here shown that MALDI-TOF MS with Soft Biotype 2.0 and its database could facilitate rapid identification of S. pyogenes. It may present an attractive alternative to traditional biochemical methods of identification. However, for classification, more isolates and advances in the MALDI-TOF MS technology are needed to improve accuracy.

  17. [Orbital cellulitis complicated by subperiosteal abscess due to Streptococcus pyogenes infection].

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    Ruíz Carrillo, José Daniel; Vázquez Guerrero, Edwin; Mercado Uribe, Mónica Cecilia

    Orbital cellulitis is an infectious disease that is very common in pediatric patients, in which severe complications may develop. Etiological agents related to this disease are Haemophilus influenzae B, Staphylococcus aureus, Streptococcus pneumoniae and Moraxella catarrhalis, which correspond to 95% of cases. Moreover, Streptococcus beta hemolytic and anaerobic microorganisms may also be present corresponding to < 5% of the cases. We present an uncommon case of cellulitis complicated by sub-periosteal abscess caused by Streptococcus pyogenes (Group A beta hemolytic streptococcus). A 9-year-old male patient with a history of deficit disorder and hyperactivity since 5 years of age. His current condition started with erythema in the external edge of the right eye, increase in peri-orbicular volume with limitation of eyelid opening, progression to proptosis, pain with eye movements and conjunctival purulent discharge. Image studies reported subperiosteal abscess and preseptal right with extraocular cellulitis. The patient started with empirical antibiotic treatment, surgical drainage and culture of purulent material from which Streptococcus pyogenes was isolated. Due to the implementation of vaccination schemes against H. influenza and S. pneumoniae since the 90s, the cases by these pathogens have decreased, causing new bacteria to take place as the cause of the infection. The importance of considering S. pyogenes as an etiology of orbital cellulitis is the rapid progression to abscess formation, and the few cases described in the literature. Copyright © 2017 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

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

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    Fischetti, Vincent A; Dale, James B

    2016-05-17

    The ability to hide in the animal kingdom is essential for survival; the same is true for bacteria. Streptococcus pyogenes is considered one of the more successful stealth bacteria in its production of a hyaluronic acid capsule that is chemically identical to the hyaluronic acid lining human joints. It has also acquired the capacity to enter eukaryotic cells to avoid the onslaught of the host's immune defenses, as well as drugs. From this intracellular vantage point, it may remain dormant from days to weeks, only to cause disease again at a later time, perhaps causing a relapse in a drug-treated patient. We now learn that it is able to enter macrophages as well, enabling the Streptococcus to use this "Trojan horse" approach to be transported to distant sites in the body. Copyright © 2016 Fischetti and Dale.

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

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    Vincent A. Fischetti

    2016-05-01

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

  20. Cell Death Induction By Streptococcus Pyogenes in Four Types of Malignant Cell Llines

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    Hamid Mollaii

    2010-02-01

    Full Text Available Background:The interest in using bacteria as anti- cancer therapeutic agents dates back to the end of the19th century. Some bacteria like Salmonella and Listeria replicate effectively inside malignant cell lines and suppress their growth. The bacterium Streptococcus pyogenes has become medically famous as a flesh-eating pathogen since mid-1980s. It is the causative agent of a life threatening clinical condition called necrotizing fasciitis. S. pyogenes usually produces a range of lytic enzymes that promote bacterial pathogenesis. With these characters, could this bacteria. be employed as a curing agent for certain cancers? The aim of this study was to determine the influence of S. pyogenes on malignant cellular death (apoptosis or necrosis- in an ex-vivo "experimental- interventional" study.Methods: The cytotoxicity of fifteen internalized streptococcal strains( including 12 clinical isolates, 2 known M types [M1, M3] and standard strain, on four types of malignant cell lines- A549, BT-20, PC-3, L-929- were tested by Trypan blue exclusion, DNAfragmentation and WST-1 methods. The streptococcal protease, lipase, DNase and serum opacity factor (SOF were tested concurrently. The standard strain of Streptococcus (Enterococcus faecalis was employed as negative control. The results were analyzed by statistical Minitab software.   Results: The overall cytotoxicity rate of -internalized- S. pyogenes was 57% by trypan blue method and 50 % by DNA electrophoresis. False positive results occurred for the negative control in WST-1; therefore this test did not present reasonable results. The correlation between production of SOF, lipase, DNase and cytotoxicity of S. pyogenes was not significant (p > 0.05. However, 67% of the protease positive strains induced cellular death in at least one type of - malignant cell line (p

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

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

    2016-05-01

    Streptococcus pyogenes is a causative agent of streptococcal toxic shock syndrome (STSS). Mutations in covR/S or rgg, negative regulators, can reportedly modulate the severity of infection in this pathogen. Recently, we showed that the regions encoding the SalR-SalK, a two-component regulatory system, were deleted in some emm 1-type isolates (named as 'novel-type'). In this study, the two novel 'STSS' isolates 10-85stss and 11-171stss were more virulent than the two novel 'non-STSS' isolates 11O-2non and 11T-3non when examined using a mouse model of invasive infection. Genome-sequencing experiments using the three strains 10-85stss , 11-171stss , and 11O-2non detected only one single nucleotide polymorphism that causes a non-synonymous mutation in fabT encoding a transcriptional regulator in strain 11O-2non . Loss of fabT reduced the high level of virulence observed in the STSS isolates to that in the non-STSS isolates, and introduction of an intact fabT compensated the lower virulence of 11O-2non , suggesting that the mutation in fabT, but not in covR/S or rgg, is involved in the differential virulence among the novel-type clinical isolates. This type of non-synonymous fabT mutation was also identified in 12 non-STSS isolates (including 11O-2non and 11T-3non ), and most of those 12 isolates showed impaired FabT function. © 2016 APMIS. Published by John Wiley & Sons Ltd.

  2. Importance of adhesins in the recurrence of pharyngeal infections caused by Streptococcus pyogenes.

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    Wozniak, Aniela; Scioscia, Natalia; Geoffroy, Enrique; Ponce, Iván; García, Patricia

    2017-04-01

    Pharyngo-amygdalitis is the most common infection caused by Streptococcus pyogenes (S. pyogenes). Reinfection with strains of different M types commonly occurs. However, a second infection with a strain of the same M type can still occur and is referred to as recurrence. We aimed to assess whether recurrence of S. pyogenes could be associated to erythromycin resistance, biofilm formation or surface adhesins like fibronectin-binding proteins and pilus proteins, both located in the fibronectin-binding, collagen-binding, T-antigen (FCT) region. We analyed clinical isolates of S. pyogenes obtained from children with multiple positive cultures of throat swabs. We analysed potential associations between M types, clonal patterns, biofilm production and FCT types with their capacity of producing a recurrent infection. We genetically defined recurrence as an infection with the same M type (same strain) and reinfection as an infection with a different M type. No differences were observed between recurrent and reinfection isolates in relation to erythromycin resistance, presence and number of domains of prtF1 gene, and biofilm formation capacity; the only significant difference was the higher frequency of FCT-4 type among recurrent isolates. However, when all the factors that could contribute to recurrence (erythromycin resistance, biofilm production, presence of prtF1 gene and FCT-4 type) were analysed together, we observed that recurrent isolates have a higher number of factors than reinfection isolates. Recurrence seems not to be associated with biofilm formation. However, pili and fibronectin-binding proteins could be associated with recurrence because FCT-4 isolates which harbour two fibronectin-binding proteins are more frequent among recurrent isolates.

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

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

    2016-01-01

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

  4. Platelet Activation by Streptococcus pyogenes Leads to Entrapment in Platelet Aggregates, from Which Bacteria Subsequently Escape

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    Svensson, Lisbeth; Baumgarten, Maria; Mörgelin, Matthias

    2014-01-01

    Platelet activation and aggregation have been reported to occur in response to a number of Gram-positive pathogens. Here, we show that platelet aggregates induced by Streptococcus pyogenes were unstable and that viable bacteria escaped from the aggregates over time. This was not due to differential activation in response to the bacteria compared with physiological activators. All the bacterial isolates induced significant platelet activation, including integrin activation and alpha and dense-granule release, at levels equivalent to those induced by potent physiological platelet activators that induced stable aggregates. The ability to escape the aggregates and to resist the antibacterial effects of platelets was dependent on active protein synthesis by the bacteria within the aggregate. We conclude that S. pyogenes bacteria can temporarily cover themselves with activated platelets, and we propose that this may facilitate survival of the bacteria in the presence of platelets. PMID:25069984

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

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    Dharm Raj Bhatta

    2014-02-01

    Full Text Available Objective: To determine the incidence of carrier state of Haemophilus influenzae type b, Streptococcus pneumoniae (S. pneumoniae, Streptococcus pyogenes, Neisseria meningitidis and Corynebacterium diphtheriae among school children. Methods: Specimen from posterior pharyngeal wall and tonsils were collected on calcium alginate coated swabs from 1 02 participants. Processing of specimen and antimicrobial susceptibility testing was done by standard procedures. Results: Potential pathogens isolated in our study were S. pneumoniae (14.7%, Staphylococcus aureus (12.7%, Corynebacterium diphtheriae (3.9%, Streptococcus pyogenes (3.9% and Haemophilus influenzae (1.9%. Important findings in antibiogram include high resistance of S. pneumoniae to penicillin (73% and resistance of Staphylococcus aureus to oxacillin (23%. Conclusions: Pharyngeal colonization by S. pneumoniae among school children was found high and there is need of introduction of pneumococcal vaccines among children. Despite expected universal vaccination, pharyngeal colonization by Corynebacterium diphtheriae is possible and there is possibility of transmission.

  6. The ScpC Protease of Streptococcus pyogenes Affects the Outcome of Sepsis in a Murine Model ▿

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    Sjölinder, Hong; Lövkvist, Lena; Plant, Laura; Eriksson, Jens; Aro, Helena; Jones, Allison; Jonsson, Ann-Beth

    2008-01-01

    The ScpC protease of Streptococcus pyogenes degrades interleukin-8 (IL-8), a chemokine that mediates neutrophil transmigration and activation. The ability to degrade IL-8 differs dramatically among clinical isolates of S. pyogenes. Bacteria expressing ScpC overcome immune clearance by preventing the recruitment of neutrophils in soft tissue infection of mice. To study the role of ScpC in streptococcal sepsis, we generated an ScpC mutant that did not degrade IL-8 and thus failed to prevent the...

  7. Molecular epidemiology, antimicrobial susceptibilities and resistance mechanisms of Streptococcus pyogenes isolates resistant to erythromycin and tetracycline in Spain (1994–2006

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    Rubio-López Virginia

    2012-09-01

    Full Text Available Abstract Background Group A Streptococcus (GAS causes human diseases ranging in severity from uncomplicated pharyngitis to life-threatening necrotizing fasciitis and shows high rates of macrolide resistance in several countries. Our goal is to identify antimicrobial resistance in Spanish GAS isolates collected between 1994 and 2006 and to determine the molecular epidemiology (emm/T typing and PFGE and resistance mechanisms of those resistant to erythromycin and tetracycline. Results Two hundred ninety-five out of 898 isolates (32.8% were erythromycin resistant, with the predominance of emm4T4, emm75T25, and emm28T28, accounting the 67.1% of the 21 emm/T types. Spread of emm4T4, emm75T25 and emm28T28 resistant clones caused high rates of macrolide resistance. The distribution of the phenotypes was M (76.9%, cMLSB (20.3%, iMLSB (2.7% with the involvement of the erythromycin resistance genes mef(A (89.5%, msr(D (81.7%, erm(B (37.3% and erm(A (35.9%. Sixty-one isolates were tetracycline resistant, with the main representation of the emm77T28 among 20 emm/T types. To note, the combination of tet(M and tet(O tetracycline resistance genes were similar to tet(M alone reaching values close to 40%. Resistance to both antibiotics was detected in 19 isolates of 7 emm/T types, being emm11T11 and the cMLSB phenotype the most frequent ones. erm(B and tet(M were present in almost all the strains, while erm(A, mef(A, msr(D and tet(O appeared in less than half of them. Conclusions Spanish GAS were highly resistant to macrolides meanwhile showed minor resistance rate to tetracycline. A remarkable correlation between antimicrobial resistance and emm/T type was noticed. Clonal spread of emm4T4, emm75T25 and emm28T28 was the main responsable for macrolide resistance where as that emm77T28 clones were it to tetraclycline resistance. A wide variety of macrolide resistance genes were responsible for three macrolide resistance phenotypes.

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

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    Abraham, Tintu; Sistla, Sujatha

    2016-07-01

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

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

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

    2016-01-01

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

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

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    Glauber P Arêas

    2014-11-01

    Full Text Available 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.

  11. Meningite neonatal por Streptococcus pyogenes e trombose de seio sagital: relato de caso Neonatal Streptococcus pyogenes meningitis and sagittal sinus thrombosis: case report

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    VERA LÚCIA JORNADA KREBS

    1998-12-01

    Full Text Available Relatamos um caso de meningite por Streptococcus pyogenes em menina de 18 dias de vida, com evolução complicada por trombose de seio sagital. São discutidos alguns aspectos da patogênese, tratamento e seguimento da doença. Frente ao aumento mundial das infecções estreptocócicas graves nos últimos 10 anos, é provável que a meningite neonatal por Streptococcus pyogenes se torne mais frequente no futuro, sendo importante estar alerta para o diagnóstico precoce e as possíveis complicações dessa infecção potencialmente letal.We report a case of Streptococcus pyogenes meningitis in a 18 days year-old-girl with clinical course complicated by sagittal sinus thrombosis. Some aspects of the pathogenesis, treatment and follow-up of the disease are discussed. The world increase of serious streptococcal infections in the last 10 years, probably will become neonatal Streptococcus pyogenes meningitis more frequent in the future and it is important to be alert for the precocious diagnosis and the possible complications of that potentially lethal infection.

  12. Members of a new subgroup of Streptococcus anginosus harbor virulence related genes previously observed in Streptococcus pyogenes.

    Science.gov (United States)

    Babbar, Anshu; Kumar, Venkatesan Naveen; Bergmann, René; Barrantes, Israel; Pieper, Dietmar H; Itzek, Andreas; Nitsche-Schmitz, D Patric

    2017-04-01

    Conventionally categorized as commensals, the Streptococci of the species S. anginosus are facultative human pathogens that are difficult to diagnose and often overlooked. Furthermore, detailed investigation and diagnosis of S. anginosus infections is hampered by unexplored taxonomy and widely elusive molecular pathogenesis. To explore their pathogenic potential, S. anginosus isolates collected from patients of two geographical locations (Vellore, India and Leipzig, Germany) were subjected to multi-locus sequence analysis (MLSA). This analysis revealed the potential presence of a new distinct clade of the species S. anginosus, tentatively termed here as genomosubspecies vellorensis. A complementary PCR-based screening for S. pyogenes virulence factor as well as antibiotic resistance genes revealed not only the presence of superantigen- and extracellular DNase coding genes identical to corresponding genes of S. pyogenes, but also of erythromycin and tetracycline resistance genes in the genomes of the analyzed S. anginosus isolates, thus posing a matter of significant health concern. Identification of new pathogenic S. anginosus strains capable of causing difficult to treat infections may pose additional challenges to the diagnosis and treatment of Streptococcus based infections. Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. Streptococcus pyogenes biofilms – formation, biology,and clinical relevance

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    Tomas eFiedler

    2015-02-01

    Full Text Available 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.

  14. Molecular epidemiology, antimicrobial susceptibility, and characterization of macrolide-resistant Streptococcus pyogenes in Japan.

    Science.gov (United States)

    Tanaka, Yuhei; Gotoh, Kenji; Teramachi, Mariko; Ishimoto, Kazuhisa; Tsumura, Naoki; Shindou, Shizuo; Yamashita, Yushiro

    2016-11-01

    Here we report the molecular epidemiology of macrolide-resistant Streptococcus pyogenes (group A streptococci, GAS) isolated from children with pharyngotonsillitis between 2011 and 2013 in Japan. In 299 isolates, 124 (41.5%) isolates were macrolide-resistant. We characterized the isolates by emm typing, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Of 299 isolates, 124 (41.5%) were macrolide-resistant isolates, 76 (61.3%) possessed mefA and 46 (37.1%) possessed ermB. All 76 isolates with mefA possessed msrD. There were no isolates possessed ermTR in this study. Eight emm/MLST types were observed. The predominant type was emm1/ST28 (57 isolates, 46.0%), which possessed the mefA/msrD complex, presenting as the M phenotype. The second most predominant type was emm12/ST467, which possessed ermB, presenting as the cMLS B phenotype. Of the cMLS B phenotype isolates, types emm28/ST52 and emm12/ST36 had multiple genetic backgrounds. We found high proportions of macrolide-resistant GAS in the southwestern areas of Japan. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  15. Complete Genome Sequences of emm111 Type Streptococcus pyogenes Strain GUR, with Antitumor Activity, and Its Derivative Strain GURSA1 with an Inactivated emm Gene

    DEFF Research Database (Denmark)

    Suvorova, Maria A; Tsapieva, Anna N; Bak, Emilie Glad

    2017-01-01

    We present here the complete genome sequence of Streptococcus pyogenes type emm111 strain GUR, a throat isolate from a scarlet fever patient, which has been used to treat cancer patients in the former Soviet Union. We also present the complete genome sequence of its derivative strain GURSA1...

  16. Genomic analysis of a Streptococcus pyogenes strain causing endocarditis in a child

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    M. Beye

    2017-05-01

    Full Text Available We sequenced the genome of Streptococcus pyogenes strain G773 that caused an infective endocarditis in a 4-year-old boy suffering from acute endocarditis. The 1.9-Mb genome exhibited a specific combination of virulence factors including a complete integrative and conjugative element, sp2905, previously described as incomplete in S. pyogenes, and five bacteriocin-coding genes. However, strain G773 lacked a CRISPR-Cas system.

  17. Macrolide resistance can be transferred by conjugation from viridans streptococci to Streptococcus pyogenes.

    Science.gov (United States)

    Jönsson, Maria; Swedberg, Göte

    2006-08-01

    Efflux pumps encoded by mef genes are among the most common mechanisms of resistance to macrolides. These genes are often located on horizontally transferable elements such as transposons. We present data indicating conjugative transfer of the mef(E) gene from viridans streptococci to the pathogen Streptococcus pyogenes. The mef(E) gene is located on the previously described MEGA (macrolide efflux genetic assembly) element. Of 110 isolates tested, 85% of those that carried the mef(A/E) gene carried it on MEGA, and in all cases of conjugal transfer of the mef(E) gene it was carried on MEGA. It therefore appears reasonable to draw the conclusion that this element is important in the lateral transfer of macrolide resistance between streptococci.

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

    Science.gov (United States)

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

    2016-01-01

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

  19. Mechanism and regulation of phosphate transport in Streptococcus pyogenes

    International Nuclear Information System (INIS)

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

    1987-01-01

    In contrast to results reported with other bacteria, uptake of 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 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

  20. Dynamics in prophage content of invasive and noninvasive M1 and M28 Streptococcus pyogenes isolates in the Netherlands from 1959 to 1996

    NARCIS (Netherlands)

    Vlaminckx, B.J.M.; Schuren, F.H.J.; Montijn, R.C.; Caspers, M.P.M.; Beitsma, M.M.; Wannet, W.J.B.; Schouls, L.M.; Verhoef, J.; Jansen, W.T.M.

    2007-01-01

    Invasive group A streptococcal (GAS) disease reemerged in The Netherlands in the late 1980s. To seek an explanation for this resurgence, the genetic compositions of 22 M1 and 19 M28 GAS strains isolated in The Netherlands between 1960s and the mid-1990s were analyzed by using a mixed-genome DNA

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

    Science.gov (United States)

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

    2016-05-31

    For over a century, a fundamental objective in infection biology research has been to understand the molecular processes contributing to the origin and perpetuation of epidemics. Divergent hypotheses have emerged concerning the extent to which environmental events or pathogen evolution dominates in these processes. Remarkably few studies bear on this important issue. Based on population pathogenomic analysis of 1,200 Streptococcus pyogenes type emm89 infection isolates, we report that a series of horizontal gene transfer events produced a new pathogenic genotype with increased ability to cause infection, leading to an epidemic wave of disease on at least two continents. In the aggregate, these and other genetic changes substantially remodeled the transcriptomes of the evolved progeny, causing extensive differential expression of virulence genes and altered pathogen-host interaction, including enhanced immune evasion. Our findings delineate the precise molecular genetic changes that occurred and enhance our understanding of the evolutionary processes that contribute to the emergence and persistence of epidemically successful pathogen clones. The data have significant implications for understanding bacterial epidemics and for translational research efforts to blunt their detrimental effects. The confluence of studies of molecular events underlying pathogen strain emergence, evolutionary genetic processes mediating altered virulence, and epidemics is in its infancy. Although understanding these events is necessary to develop new or improved strategies to protect health, surprisingly few studies have addressed this issue, in particular, at the comprehensive population genomic level. Herein we establish that substantial remodeling of the transcriptome of the human-specific pathogen Streptococcus pyogenes by horizontal gene flow and other evolutionary genetic changes is a central factor in precipitating and perpetuating epidemic disease. The data unambiguously show that

  2. A Case of Systemic Infection Caused by Streptococcus pyogenes Oral Infection in an Edentulous Patient.

    Science.gov (United States)

    Inagaki, Yumi; Abe, Masanobu; Inaki, Ryoko; Zong, Liang; Suenaga, Hideyuki; Abe, Takahiro; Hoshi, Kazuto

    2017-08-18

    Infections in the oral and maxillofacial region can sometimes extend beyond the oral cavity, with serious consequences. Most oral infections are odontogenic, occurring through the root apex of the tooth or the periodontal pocket. It thus makes sense that edentulous patients have a much lower risk of oral bacterial infection. For this reason, while there are many reports on systemic infections caused by oral infections, few of these describe such infections in edentulous patients. We present a case of oral and maxillofacial cellulitis followed by sepsis due to Streptococcus pyogenes infection in an 89-year-old Japanese edentulous woman. S. pyogenes was detected in the wound of left maxilla and the blood sample. S. pyogenes has been reported to be one of the most common and influential aerobic bacteria associated with deep neck infection and subsequent systemic infection. Left maxillary sinusitis was observed, and this could be the origin of the S. pyogenes infection. S. pyogenes derived from the sinusitis and leaked to the oral cavity might have caused systemic infection through wounding of the oral mucosa. Fortunately, intensive antibiotic therapy was effective, and the patient recovered without any surgical procedures. We experienced a rare case of oral and maxillofacial cellulitis followed by sepsis due to a Streptococcus pyogenes infection in an old edentulous woman. This result indicated that, while edentulous patients are considered to have no risk of odontogenic infection, they still carry a risk of bacterial infection.

  3. The microbiology of impetigo in indigenous children: associations between Streptococcus pyogenes, Staphylococcus aureus, scabies, and nasal carriage.

    Science.gov (United States)

    Bowen, Asha C; Tong, Steven Y C; Chatfield, Mark D; Carapetis, Jonathan R

    2014-12-31

    Impetigo is caused by both Streptococcus pyogenes and Staphylococcus aureus; the relative contributions of each have been reported to fluctuate with time and region. While S. aureus is reportedly on the increase in most industrialised settings, S. pyogenes is still thought to drive impetigo in endemic, tropical regions. However, few studies have utilised high quality microbiological culture methods to confirm this assumption. We report the prevalence and antimicrobial resistance of impetigo pathogens recovered in a randomised, controlled trial of impetigo treatment conducted in remote Indigenous communities of northern Australia. Each child had one or two sores, and the anterior nares, swabbed. All swabs were transported in skim milk tryptone glucose glycogen broth and frozen at -70°C, until plated on horse blood agar. S. aureus and S. pyogenes were confirmed with latex agglutination. From 508 children, we collected 872 swabs of sores and 504 swabs from the anterior nares prior to commencement of antibiotic therapy. S. pyogenes and S. aureus were identified together in 503/872 (58%) of sores; with an additional 207/872 (24%) sores having S. pyogenes and 81/872 (9%) S. aureus, in isolation. Skin sore swabs taken during episodes with a concurrent diagnosis of scabies were more likely to culture S. pyogenes (OR 2.2, 95% CI 1.1 - 4.4, p = 0.03). Eighteen percent of children had nasal carriage of skin pathogens. There was no association between the presence of S. aureus in the nose and skin. Methicillin-resistance was detected in 15% of children who cultured S. aureus from either a sore or their nose. There was no association found between the severity of impetigo and the detection of a skin pathogen. S. pyogenes remains the principal pathogen in tropical impetigo; the relatively high contribution of S. aureus as a co-pathogen has also been confirmed. Children with scabies were more likely to have S. pyogenes detected. While clearance of S. pyogenes is the key

  4. Pyogenic liver abscess secondary to disseminated Streptococcus Anginosus from Sigmoid Diverticulitis

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    Shishir Murarka

    2011-01-01

    Full Text Available Pyogenic liver abscess secondary to dissemination from Sigmoid diverticulitis is rare. Streptococcus anginosus has been linked to abscesses but has been rarely reported from a Sigmoid diverticulitis source. We report a case of liver abscess in which the source was confounding but eventually was traced to Sigmoid diverticulitis on laparotomy.

  5. Streptococcus pyogenes meningitis in children: report of two cases and literature review

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    Mariana V. Arnoni

    Full Text Available Streptococcus pyogenes meningitis (SPM occurs sporadically, even with the increase of invasive streptococcal disease observed in the past years. We reported two cases of SPM in infants to alert pediatricians for the possibility of this agent as a cause of meningitis in previously healthy children.

  6. Streptococcus pyogenes udgående fra tonsilfokus som mulig årsag til alvorlig sepsis

    DEFF Research Database (Denmark)

    Alimoradi, Jalal; Lisby, Gorm; Jeppesen, Jørgen

    2009-01-01

    Streptococcus pyogenes (SP) is a common bacterial pathogen. For the past two decades, several studies have reported an increase in the severity and the incidence of SP infections. Case: a 60-year-old female admitted to the hospital with tonsillitis acuta verified by strep-A test was initially...

  7. Streptococcus pyogenes udgående fra tonsilfokus som mulig årsag til alvorlig sepsis

    DEFF Research Database (Denmark)

    Alimoradi, Jalal; Lisby, Gorm; Jeppesen, Jørgen

    2009-01-01

    Streptococcus pyogenes (SP) is a common bacterial pathogen. For the past two decades, several studies have reported an increase in the severity and the incidence of SP infections. Case: a 60-year-old female admitted to the hospital with tonsillitis acuta verified by strep-A test was initially tre...

  8. Streptococcal toxic shock syndrome caused by the dissemination of an invasive emm3/ST15 strain of Streptococcus pyogenes.

    Science.gov (United States)

    Sekizuka, Tsuyoshi; Nai, Emina; Yoshida, Tomohiro; Endo, Shota; Hamajima, Emi; Akiyama, Satoka; Ikuta, Yoji; Obana, Natsuko; Kawaguchi, Takahiro; Hayashi, Kenta; Noda, Masahiro; Sumita, Tomoko; Kokaji, Masayuki; Katori, Tatsuo; Hashino, Masanori; Oba, Kunihiro; Kuroda, Makoto

    2017-12-18

    Streptococcus pyogenes (group A Streptococcus [GAS]) is a major human pathogen that causes a wide spectrum of clinical manifestations. Although invasive GAS (iGAS) infections are relatively uncommon, emm3/ST15 GAS is a highly virulent, invasive, and pathogenic strain. Global molecular epidemiology analysis has suggested that the frequency of emm3 GAS has been recently increasing. A 14-year-old patient was diagnosed with streptococcal toxic shock syndrome and severe pneumonia, impaired renal function, and rhabdomyolysis. GAS was isolated from a culture of endotracheal aspirates and designated as KS030. Comparative genome analysis suggested that KS030 is classified as emm3 (emm-type) and ST15 (multilocus sequencing typing [MLST]), which is similar to iGAS isolates identified in the UK (2013) and Switzerland (2015). We conclude that the global dissemination of emm3/ST15 GAS strain has the potential to cause invasive disease.

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

    Science.gov (United States)

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

    2016-06-01

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

  10. A cluster of ecthyma outbreaks caused by a single clone of invasive and highly infective Streptococcus pyogenes.

    Science.gov (United States)

    Wasserzug, Oshri; Valinsky, Lea; Klement, Eyal; Bar-Zeev, Yael; Davidovitch, Nadav; Orr, Nadav; Korenman, Zina; Kayouf, Raid; Sela, Tamar; Ambar, Ruhama; Derazne, Estela; Dagan, Ron; Zarka, Salman

    2009-05-01

    Ecthyma is an invasive, ulcerated skin infection. Four ecthyma outbreaks occurred in different infantry units in the Israeli Defense Force from October 2004 through February 2005. Morbidity attack rates in the first 3 outbreaks were 89% (49 of 55 soldiers), 73% (32 of 44), and 82% (37 of 45). In the fourth outbreak, in which early intervention (antimicrobial treatment and improvement of hygiene) was applied, the attack rate was 25% (10 of 40 soldiers). In the first outbreak cluster, 4 soldiers experienced poststreptococcal glomerulonephritis, and 5 cases of systemic sequelae were recorded (1 case of severe septic shock, 3 cases of pneumonia, and 1 case of septic olecranon bursitis). Streptococcus pyogenes and Staphylococcus aureus were isolated from ecthyma sores, oropharynx, and anterior nares of affected and unaffected soldiers involved in all 4 outbreaks. Although the S. aureus isolates had different genomic profiles, >90% of S. pyogenes isolates were identified as belonging to a single clone, emm type 81, T type 8. Epidemiological investigation revealed that the hygiene levels of the soldiers and their living conditions were probably the most important cause for the difference in attack rates, wound severity, and systemic sequelae found between and within the units. Our study demonstrates the possible ramifications of the combination of a virulent and highly infective S. pyogenes strain and poor living conditions, and it emphasizes the importance of early intervention in such conditions.

  11. Características de la resistencia antimicrobiana de una colección clínica de Strptococcus pyogenes Antimicrobial resistance of Streptococcus pyogenes clinical strains

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    Romeo S. Rodríguez

    2000-06-01

    Full Text Available OBJETIVO: Determinar la susceptibilidad antimicrobiana de Streptococcus pyogenes con el fin de estimar la prevalencia de los fenotipos de resistencia a los macrólidos. MATERIAL Y MÉTODOS: Se realizó un estudio de tipo transversal, en 1999, en el que se evaluaron 100 cepas de S. pyogenes, aislados en el Hospital Infantil de México Federico Gómez, en el lapso comprendido entre 1992 y 1998, procedentes de niños con faringoamigdalitis, conservadas en congelación en el laboratorio de bacteriología hasta su procesamiento. Se determinó la susceptibilidad antimicrobiana a algunos beta-lactámicos, macrólidos y clindamicina. La resistencia a eritromicina se probó por medio de la prueba de difusión de doble disco. Se calcularon medidas de tendencia central. RESULTADOS: Todas las cepas fueron sensibles a los beta-lactámicos y clindamicina; 16% fueron resistentes a los macrólidos, y todas correspondieron al fenotipo M. CONCLUSIONES: Es conveniente realizar periódicamente pruebas de escrutinio para conocer los posibles cambios en los patrones de sensibilidad estreptocócica.OBJECTIVE: To determine the antibiotic susceptibility of recent isolates of Streptococcus pyogenes and to evaluate the prevalence of macrolide-resistant phenotypes. MATERIAL AND METHODS: In 1999, we conducted a cross-sectional study at Mexico Children's Hospital "Federico Gomez", to analyze one hundred strains of S. pyogenes isolated from 1992 to 1998, in children with uncomplicated pharyngotonsillitis. Strains were frozen at the bacteriology lab until they were analyzed. Strains were tested for susceptibility against some beta-lactams, macrolides and clindamycin. Double-disk testing was carried out to evaluate erythromycin-resistant phenotypes. Data are presented using central tendency measures. RESULTS: All tested strains were not resistant to beta-lactams and clindamycin; 16% of the strains were resistant to macrolides and all of them belonged to phenotype M. CONCLUSIONS

  12. Chromosomal Islands of Streptococcus pyogenes and related streptococci: Molecular Switches for Survival and Virulence

    Directory of Open Access Journals (Sweden)

    Scott Van Nguyen

    2014-08-01

    Full Text Available 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 13-20 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.

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

    Science.gov (United States)

    Nguyen, Scott V; McShan, William M

    2014-01-01

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

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

    DEFF Research Database (Denmark)

    Lannergård, Jonas; Kristensen, Bodil M.; Gustafsson, Mattias C. U.

    2015-01-01

    The M protein of Streptococcus pyogenes, a major bacterial virulence factor, has an amino-terminal hypervariable region (HVR) that is a target for type-specific protective antibodies. Intriguingly, the HVR elicits a weak antibody response, indicating that it escapes host immunity by two mechanisms...... fibrinogen-binding B repeat region exhibits extensive sequence divergence. Analysis of antisera from S. pyogenes-infected patients, infected mice, and immunized mice showed that both the HVR and the B repeat region elicited weak antibody responses, while the conserved carboxy-terminal part was immunodominant...

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

    NARCIS (Netherlands)

    Levering, J.; Fiedler, T.; Sieg, A.; van Grinsven, K.W.A.; Hering, S.; Veith, N.; Olivier, B.G.; Klett, L.; Hugenholtz, J.; Teusink, B.; Kreikemeyer, B.; Kummer, U.

    2016-01-01

    Genome-scale metabolic models comprise stoichiometric relations between metabolites, as well as associations between genes and metabolic reactions and facilitate the analysis of metabolism. We computationally reconstructed the metabolic network of the lactic acid bacterium Streptococcus pyogenes

  16. Activation of TAFI on the surface of Streptococcus pyogenes evokes inflammatory reactions by modulating the kallikrein/kinin system

    NARCIS (Netherlands)

    Bengtson, Sara H.; Sandén, Caroline; Mörgelin, Matthias; Marx, Pauline F.; Olin, Anders I.; Leeb-Lundberg, L. M. Fredrik; Meijers, Joost C. M.; Herwald, Heiko

    2008-01-01

    Bacteria-controlled regulation of host responses to infection is an important virulence mechanism that has been demonstrated to contribute to disease progression. Here we report that the human pathogen Streptococcus pyogenes employs the procarboxypeptidase TAFI (thrombin-activatable fibrinolysis

  17. Pleural empyema and streptococcal toxic shock syndrome due to Streptococcus pyogenes in a healthy Spanish traveler in Japan

    Directory of Open Access Journals (Sweden)

    Tetsuya Sakai

    2017-01-01

    Full Text Available Group A Streptococcus (GAS, Streptococcus pyogenes causes invasive infections including streptococcal toxic shock syndrome (STSS and local infections. To our knowledge, this is the first report of a case of an invasive GAS infection with pneumonia and pleural empyema (PE followed by STSS (disseminated intravascular coagulation [DIC] and acute renal insufficiency in a healthy male adult. He received combined supportive therapies of PE drainage, anti-DIC agent, hemodialysis, and antimicrobials and eventually made a clinical recovery. GAS isolated from PE was found to have emm1/speA genes, suggestive of a pathogenic strain. Clinicians should be aware of the possibility of this disease entity (pneumonia, PE, and STSS in healthy male adults as well as children and adult women.

  18. Increase in fluoroquinolone non-susceptibility among clinical Streptococcus pyogenes in Belgium during 2007-10.

    Science.gov (United States)

    Van Heirstraeten, Liesbet; Leten, Gert; Lammens, Christine; Goossens, Herman; Malhotra-Kumar, Surbhi

    2012-11-01

    To study the temporal evolution of fluoroquinolone non-susceptibility among Streptococcus pyogenes during 2007-10 in Belgium. S. pyogenes (n = 4690) recovered from patients with tonsillopharyngitis or skin, wound or invasive infections were screened for fluoroquinolone non-susceptibility. A selection of fluoroquinolone-non-susceptible strains was investigated for resistance mechanisms: reserpine-sensitive efflux and mutations in topoisomerase genes parC and gyrA. Clonality was determined by emm typing. Fluoroquinolone non-susceptibility (ciprofloxacin MIC ≥2 mg/L) was identified in 535 (11.4%) of 4690 S. pyogenes recovered during 2007-10 in Belgium. The proportion of fluoroquinolone-non-susceptible S. pyogenes increased significantly from 4.3% (2008) to 10.9% (2009) to 21.6% (2010) and coincided with a significant increase in emm6 strains among fluoroquinolone-non-susceptible S. pyogenes. Ciprofloxacin MICs of 2-8 mg/L correlated with first-step ParC substitutions. Two high-level fluoroquinolone-resistant S. pyogenes strains (ciprofloxacin MICs 32 mg/L) showed second-step substitutions in GyrA (Ser-81→Phe or Tyr) in addition to first-step mutations in parC. Reserpine-sensitive efflux was not observed. We report an unprecedented increase in fluoroquinolone-non-susceptible S. pyogenes in Belgium, a country with high quinolone use, as well as emergence of two high-level fluoroquinolone-resistant S. pyogenes strains with second-step mutations in gyrA, warning us of the need for more prudent use of fluoroquinolones and for continued resistance surveillance.

  19. Genome sequence analysis of emm89 Streptococcus pyogenes strains causing infections in Scotland, 2010-2016.

    Science.gov (United States)

    Beres, Stephen B; Olsen, Randall J; Ojeda Saavedra, Matthew; Ure, Roisin; Reynolds, Arlene; Lindsay, Diane S J; Smith, Andrew J; Musser, James M

    2017-12-01

    Strains of type emm89 Streptococcus pyogenes have recently increased in frequency as a cause of human infections in several countries in Europe and North America. This increase has been molecular epidemiologically linked with the emergence of a new genetically distinct clone, designated clade 3. We sought to extend our understanding of this epidemic behavior by the genetic characterization of type emm89 strains responsible in recent years for an increased frequency of infections in Scotland. We sequenced the genomes of a retrospective cohort of 122 emm89 strains recovered from patients with invasive and noninvasive infections throughout Scotland during 2010 to 2016. All but one of the 122 emm89 infection isolates are of the recently emerged epidemic clade 3 clonal lineage. The Scotland isolates are closely related to and not genetically distinct from recent emm89 strains from England, they constitute a single genetic population. The clade 3 clone causes virtually all-contemporary emm89 infections in Scotland. These findings add Scotland to a growing list of countries of Europe and North America where, by whole genome sequencing, emm89 clade 3 strains have been demonstrated to be the cause of an ongoing epidemic of invasive infections and to be genetically related due to descent from a recent common progenitor.

  20. Molecular epidemiological characteristics of Streptococcus pyogenes strains involved in an outbreak of scarlet fever in China, 2011.

    Science.gov (United States)

    You, Yuan Hai; Song, Yan Yan; Yan, Xiao Mei; Wang, Hai Bin; Zhang, Meng Han; Tao, Xiao Xia; Li, Lei Lei; Zhang, Yu Xin; Jiang, Xi Hong; Zhang, Bing Hua; Zhou, Hao; Xiao, Di; Jin, Lian Mei; Feng, Zi Jian; Luo, Feng Ji; Zhang, Jian Zhong

    2013-11-01

    To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011. Seventy-four Streptococcal pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011. Emm genotyping, pulsed-field gel electrophoresis (PFGE), superantigen (SAg) genes and antimicrobial susceptibility profiling were analyzed for these isolates. A total of 4 different emm types were identified. Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles. Emm12 (79.7%) and emm1 (14.9%) accounted for approximately 94% of all the isolates. The speA gene was all negative in emm12 isolates and positive in emm1 isolates. All strains were resistant to erythromycin, and 89.4% of them were resistant to erythromycin, tracycline, and clindamycin simultaneously. Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains, though no new emm type was found in this outbreak. The data provide a baseline for further surveillance of scarlet fever, which may contribute to the explanation of the outbreak and development of a GAS vaccine in China. Copyright © 2013 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  1. [Epidemiology and clinical features of Streptococcus pyogenes bacteremia in Cartagena (Murcia, Spain)].

    Science.gov (United States)

    Jimeno-Almazán, Amaya; Viqueira-Gonzalez, Montserrat; Alcalde, María Del Mar; Alcaraz-Vidal, Begoña; Vera-Méndez, Francisco

    2013-01-01

    A gradual increase in severe cases due to Streptococcus pyogenes or Streptococcus beta-hemolytic group A (SGA), has been detected in the last few decades. Retrospective study of bacteremia due to S.pyogenes detected between January 2009 and January 2013 in Cartagena. The annual incidence for severe bacteremia has been estimated. Thirteen cases of SGA bacteremia were recorded. The incidence increased from 0.37 in 2009 to 2.5 cases/100,000 inhabitants in 2012. The predominant focus was skin and soft tissue infections (53%). Early mortality was 20%. Severe streptococcal disease is rare, but affects individuals with good functional status, and is associated with a high mortality. Copyright © 2012 Elsevier España, S.L. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Linke, Christian, E-mail: clin180@ec.auckland.ac.nz [School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland (New Zealand); Caradoc-Davies, Tom T. [School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland (New Zealand); Australian Synchrotron, Clayton, Victoria 3168 (Australia); Proft, Thomas [School of Medical Sciences, University of Auckland, Private Bag 92019, Auckland (New Zealand); Baker, Edward N. [School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland (New Zealand)

    2008-02-01

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  4. Nasopharyngeal infection by Streptococcus pyogenes requires superantigen-responsive Vβ-specific T cells

    Science.gov (United States)

    Zeppa, Joseph J.; Kasper, Katherine J.; Mohorovic, Ivor; Mazzuca, Delfina M.

    2017-01-01

    The globally prominent pathogen Streptococcus pyogenes secretes potent immunomodulatory proteins known as superantigens (SAgs), which engage lateral surfaces of major histocompatibility class II molecules and T-cell receptor (TCR) β-chain variable domains (Vβs). These interactions result in the activation of numerous Vβ-specific T cells, which is the defining activity of a SAg. Although streptococcal SAgs are known virulence factors in scarlet fever and toxic shock syndrome, mechanisms by how SAgs contribute to the life cycle of S. pyogenes remain poorly understood. Herein, we demonstrate that passive immunization against the Vβ8-targeting SAg streptococcal pyrogenic exotoxin A (SpeA), or active immunization with either wild-type or a nonfunctional SpeA mutant, protects mice from nasopharyngeal infection; however, only passive immunization, or vaccination with inactive SpeA, resulted in high-titer SpeA-specific antibodies in vivo. Mice vaccinated with wild-type SpeA rendered Vβ8+ T cells poorly responsive, which prevented infection. This phenotype was reproduced with staphylococcal enterotoxin B, a heterologous SAg that also targets Vβ8+ T cells, and rendered mice resistant to infection. Furthermore, antibody-mediated depletion of T cells prevented nasopharyngeal infection by S. pyogenes, but not by Streptococcus pneumoniae, a bacterium that does not produce SAgs. Remarkably, these observations suggest that S. pyogenes uses SAgs to manipulate Vβ-specific T cells to establish nasopharyngeal infection. PMID:28794279

  5. PORTADORES ASSINTOMÁTICOS DE STREPTOCOCCUS PYOGENES E STAPHYLOCOCCUS AUREUS ENTRE CRIANÇAS ATENDIDAS EM UMA CRECHE

    Directory of Open Access Journals (Sweden)

    Alexandre Braoios

    2009-06-01

    Full Text Available Streptococcus pyogenes and Staphylococcus aureus are recognized as important infantile pathogens. Infections of pharynx caused by these microorganisms are common in individuals of 0 to 12 years. In children taken care in day-care center a serious problem of health can become, a time that the transmission in gives airmail and living together with assymptomathics carrier can unchain outbreak infections pharynx. Beyond of infection, S. pyogenes can unchain serious imunologycal sequels. The rheumatic fever and the glomerunephits are imunologycal riots that can cause cardiac and renals injuries. These pathologys demand continuous treatment to prevent re-infection. The precocious detection of assymptomathics carriers can help in the prevention of the sequels, through treatment prophylactic with antibiotics adequate. After the development of the sequel does not have available treatment for the cure of the patient. This work had for objective to detect assymptomathics carriers of S. pyogenes and S. aureus between childrens taken care of in the day-care center “Municipal Association of Minor’s Protection” in the city Presidente Bernardes, SP. For this way, oropharynx samples had been collected with aid of swab absorbed in barren physiological solution. After the culture of the samples, bacterial identification had been performed by conventional biochemistry techniques. Samples had been of 122 children of 0 to 6 years. In 10 children (8.2% were isolated S. aureus, and 2 children (1.6% were isolated S. pyogenes. Despite the low index of carriers, these few children who carry these microorganisms can become souces of contagion for the individuals that coexist together.

  6. Scarlet Fever Epidemic in China Caused by Streptococcus pyogenes Serotype M12: Epidemiologic and Molecular Analysis

    Directory of Open Access Journals (Sweden)

    Yuanhai You

    2018-02-01

    Full Text Available From 2011, Hong Kong and mainland China have witnessed a sharp increase in reported cases, with subsequent reports of epidemic scarlet fever in North Asia and the United Kingdom. Here we examine epidemiological data and investigate the genomic context of the predominantly serotype M12 Streptococcus pyogenes scarlet fever isolates from mainland China. Incident case data was obtained from the Chinese Nationwide Notifiable Infectious Diseases Reporting Information System. The relative risk of scarlet fever in recent outbreak years 2011–2016 was calculated using the median age-standardised incidence rate, compared to years 2003–2010 prior this outbreak. Whole genome sequencing was performed on 32 emm12 scarlet fever isolates and 13 emm12 non-scarlet fever isolates collected from different geographic regions of China, and compared with 203 published emm12 S. pyogenes genomes predominantly from scarlet fever outbreaks in Hong Kong (n = 134 and the United Kingdom (n = 63. We found during the outbreak period (2011–2016, the median age-standardised incidence in China was 4.14/100,000 (95% confidence interval (CI 4.11-4.18, 2.62-fold higher (95% CI 2.57-2.66 than that of 1.58/100,000 (95% CI 1.56-1.61 during the baseline period prior to the outbreak (2003−2010. Highest incidence was reported for children 5 years of age (80.5/100,000. Streptococcal toxin encoding prophage φHKU.vir and φHKU.ssa in addition to the macrolide and tetracycline resistant ICE-emm12 and ICE-HKU397 elements were found amongst mainland China multi-clonal emm12 isolates suggesting a role in selection and expansion of scarlet fever lineages in China. Global dissemination of toxin encoded prophage has played a role in the expansion of scarlet fever emm12 clones. These findings emphasize the role of comprehensive surveillance approaches for monitoring of epidemic human disease.

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

    Directory of Open Access Journals (Sweden)

    Emilienne Verkaeren

    2014-12-01

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

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

    Science.gov (United States)

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

    2016-02-01

    Streptococcus pyogenes produces molecules that inhibit the function of human immune system, thus allowing the pathogen to grow and spread in tissues. It is known that S. pyogenes CAMP factor increases erythrocytosis induced by Staphylococcus aureus β-hemolysin. However, the effects of CAMP factor for immune cells are unclear. In this study, we investigated the effects of CAMP factor to macrophages. Western blotting analysis demonstrated that all examined strains expressed CAMP factor protein. In the presence of calcium or magnesium ion, CAMP factor was significantly released in the supernatant. In addition, both culture supernatant from S. pyogenes strain SSI-9 and recombinant CAMP factor dose-dependently induced vacuolation in RAW 264.7 cells, but the culture supernatant from Δcfa isogenic mutant strain did not. CAMP factor formed oligomers in RAW 264.7 cells in a time-dependent manner. CAMP factor suppressed cell proliferation via G2 phase cell cycle arrest without inducing cell death. Furthermore, CAMP factor reduced the uptake of S. pyogenes and phagocytic activity indicator by RAW 264.7 cells. These results suggest that CAMP factor works as a macrophage dysfunction factor. Therefore, we conclude that CAMP factor allows S. pyogenes to escape the host immune system, and contribute to the spread of streptococcal infection. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  9. Delineation of Streptococcus dysgalactiae, its subspecies, and its clinical and phylogenetic relationship to Streptococcus pyogenes

    DEFF Research Database (Denmark)

    Jensen, Anders; Kilian, Mogens

    2011-01-01

    The close phylogenetic relationship of the important pathogen Streptococcus pneumoniae and several species of commensal streptococci, particularly Streptococcus mitis and Streptococcus pseudopneumoniae, and the recently demonstrated sharing of genes and phenotypic traits previously considered...

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

    Science.gov (United States)

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

    2013-09-01

    Streptococcus pyogenes (group A Streptococcus, GAS) is an important human pathogen causing mild superficial infections of skin and mucous membranes, but also life-threatening systemic diseases. S. pyogenes and other prokaryotic organisms use the arginine deiminase system (ADS) for survival in acidic environments. In this study, the arginine deiminase (AD), and carbamate kinase (CK) from S. pyogenes M49 strain 591 were heterologously expressed in Escherichia coli DH5α, purified, and kinetically characterized. AD and CK from S. pyogenes M49 share high amino acid sequence similarity with the respective enzymes from Lactococcus lactis subsp. lactis IL1403 (45.6% and 53.5% identical amino acids) and Enterococcus faecalis V583 (66.8% and 66.8% identical amino acids). We found that the arginine deiminase of S. pyogenes is not allosterically regulated by the intermediates and products of the arginine degradation (e.g., ATP, citrulline, carbamoyl phosphate). The Km and Vmax values for arginine were 1.13±0.12mM (mean±SD) and 1.51±0.07μmol/min/mg protein. The carbamate kinase is inhibited by ATP but unaffected by arginine and citrulline. The Km and Vmax values for ADP were 0.72±0.08mM and 1.10±0.10μmol/min/mg protein and the Km for carbamoyl phosphate was 0.65±0.07mM. The optimum pH and temperature for both enzymes were 6.5 and 37°C, respectively. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    1985-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Nadja Patenge

    2013-01-01

    Full Text Available 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 (KFF3K-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.

  13. Streptococcus pyogenes cluster in a care home in England April to June 2010.

    Science.gov (United States)

    Milne, L M; Lamagni, T; Efstratiou, A; Foley, C; Gilman, J; Lilley, M; Guha, S; Head, F; Han, T

    2011-11-24

    Two fatal cases of Streptococcus pyogenes emm st22.6 bacteraemia occurred in a care home in England during April and June 2010, initiating a cluster investigation. The first case had left the home 13 days before the second case took up residence. We sought further cases and carriers. We swabbed throat and chronic skin lesions from residents and staff and examined these specimens for the presence of S. pyogenes. 61 specimens were taken from 18 of 19 residents and 39 of 39 staff. All results from swabbing were culture negative. We observed infection control practices and the environment at the care home for deficiencies. Issues were identified relating to the correct use of personal protective equipment, hand hygiene, clinical waste and laundry. Infection control practices were improved and training given. Infection control practices and the environment at a care home should be examined as part of the investigation of a S. pyogenes cluster. Screening for carriage of S. pyogenes should be done before antibiotic chemoprophylaxis is issued to care home residents and staff.

  14. Throat Carriage Rate and Antimicrobial Resistance of Streptococcus pyogenes In Rural Children in Argentina.

    Science.gov (United States)

    Delpech, Gastón; Sparo, Mónica; Baldaccini, Beatriz; Pourcel, Gisela; Lissarrague, Sabina; García Allende, Leonardo

    2017-03-01

    The aim of this study was to determine the prevalence of asymptomatic carriers of group A β-hemolytic streptococci (GAS) in children living in a rural community and to investigate the association between episodes of acute pharyngitis and carrier status. Throat swabs were collected from September to November 2013 among children 5-13 years of age from a rural community (Maria Ignacia-Vela, Argentina). The phenotypic characterization of isolates was performed by conventional tests. Antimicrobial susceptibility was assayed for penicillin, tetracycline, chloramphenicol, erythromycin, and clindamycin (disk diffusion). The minimum inhibitory concentration was determined for penicillin, cefotaxime, tetracycline, and erythromycin. The carriage of β-hemolytic streptococci was detected in 18.1% of participants, with Streptococcus pyogenes in 18 participants followed by S. dysgalactiae ssp. equisimilis in 5. The highest proportion of GAS was found in 8 to 10-year-old children. No significant association between the number of episodes of acute pharyngitis suffered in the last year and the carrier state was detected ( p >0.05). Tetracycline resistance (55.5%) and macrolide-resistant phenotypes (11.1%) were observed. Resistance to penicillin, cefotaxime, or chloramphenicol was not expressed in any streptococcal isolate. The present study demonstrated significant throat carriage of GAS and the presence of group C streptococci ( S. dysgalactiae ssp. equisimilis ) in an Argentinian rural population. These results point out the need for continuous surveillance of GAS and non-GAS carriage as well as of antimicrobial resistance in highly susceptible populations, such as school-aged rural children. An extended surveillance program including school-aged children from different cities should be considered to estimate the prevalence of GAS carriage in Argentina.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    DEFF Research Database (Denmark)

    Wisniewska, Magdalena; Happonen, Lotta; Kahn, Fredrik

    2014-01-01

    Streptococcus pyogenes is a significant bacterial pathogen in the human population. The importance of virulence factors for the survival and colonization of S. pyogenes is well established, and many of these factors are exposed to the extracellular environment enabling bacterial interactions...... with the host. In the present study we quantitatively analyzed and compared S. pyogenes proteins in the growth medium of a strain that is virulent to mice, with a non-virulent strain. Particularly one of these proteins was present at significantly higher levels in stationary growth medium from the virulent......), 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...

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

    Science.gov (United States)

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

    2016-01-01

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

  18. Local Th17/IgA immunity correlate with protection against intranasal infection with Streptococcus pyogenes.

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    Rasmus Mortensen

    Full Text Available Streptococcus pyogenes (group A streptococcus, GAS is responsible for a wide array of infections. Respiratory transmission via droplets is the most common mode of transmission but it may also infect the host via other routes such as lesions in the skin. To advance the development of a future vaccine against GAS, it is therefore important to investigate how protective immunity is related to the route of vaccine administration. To explore this, we examined whether a parenterally administered anti-GAS vaccine could protect against an intranasal GAS infection or if this would require locally primed immunity. We foundd that a parenteral CAF01 adjuvanted GAS vaccine offered no protection against intranasal infection despite inducing strong systemic Th1/Th17/IgG immunity that efficiently protected against an intraperitoneal GAS infection. However, the same vaccine administered via the intranasal route was able to induce protection against repeated intranasal GAS infections in a murine challenge model. The lack of intranasal protection induced by the parenteral vaccine correlated with a reduced mucosal recall response at the site of infection. Taken together, our results demonstrate that locally primed immunity is important for the defense against intranasal infection with Streptococcus pyogenes.

  19. Local Th17/IgA immunity correlate with protection against intranasal infection with Streptococcus pyogenes.

    Science.gov (United States)

    Mortensen, Rasmus; Christensen, Dennis; Hansen, Lasse Bøllehuus; Christensen, Jan Pravsgaard; Andersen, Peter; Dietrich, Jes

    2017-01-01

    Streptococcus pyogenes (group A streptococcus, GAS) is responsible for a wide array of infections. Respiratory transmission via droplets is the most common mode of transmission but it may also infect the host via other routes such as lesions in the skin. To advance the development of a future vaccine against GAS, it is therefore important to investigate how protective immunity is related to the route of vaccine administration. To explore this, we examined whether a parenterally administered anti-GAS vaccine could protect against an intranasal GAS infection or if this would require locally primed immunity. We foundd that a parenteral CAF01 adjuvanted GAS vaccine offered no protection against intranasal infection despite inducing strong systemic Th1/Th17/IgG immunity that efficiently protected against an intraperitoneal GAS infection. However, the same vaccine administered via the intranasal route was able to induce protection against repeated intranasal GAS infections in a murine challenge model. The lack of intranasal protection induced by the parenteral vaccine correlated with a reduced mucosal recall response at the site of infection. Taken together, our results demonstrate that locally primed immunity is important for the defense against intranasal infection with Streptococcus pyogenes.

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

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    Volkart Lour

    2009-12-01

    Full Text Available Abstract Background 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. Results 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. Conclusions 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.

  1. An Approach for Identification of Novel Drug Targets in Streptococcus pyogenes SF370 Through Pathway Analysis.

    Science.gov (United States)

    Singh, Satendra; Singh, Dev Bukhsh; Singh, Anamika; Gautam, Budhayash; Ram, Gurudayal; Dwivedi, Seema; Ramteke, Pramod W

    2016-12-01

    Streptococcus pyogenes is one of the most important pathogens as it is involved in various infections affecting upper respiratory tract and skin. Due to the emergence of multidrug resistance and cross-resistance, S. Pyogenes is becoming more pathogenic and dangerous. In the present study, an in silico comparative analysis of total 65 metabolic pathways of the host (Homo sapiens) and the pathogen was performed. Initially, 486 paralogous enzymes were identified so that they can be removed from possible drug target list. The 105 enzymes of the biochemical pathways of S. pyogenes from the KEGG metabolic pathway database were compared with the proteins from the Homo sapiens by performing a BLASTP search against the non-redundant database restricted to the Homo sapiens subset. Out of these, 83 enzymes were identified as non-human homologous while 30 enzymes of inadequate amino acid length were removed for further processing. Essential enzymes were finally mined from remaining 53 enzymes. Finally, 28 essential enzymes were identified in S. pyogenes SF370 (serotype M1). In subcellular localization study, 18 enzymes were predicted with cytoplasmic localization and ten enzymes with the membrane localization. These ten enzymes with putative membrane localization should be of particular interest. Acyl-carrier-protein S-malonyltransferase, DNA polymerase III subunit beta and dihydropteroate synthase are novel drug targets and thus can be used to design potential inhibitors against S. pyogenes infection. 3D structure of dihydropteroate synthase was modeled and validated that can be used for virtual screening and interaction study of potential inhibitors with the target enzyme.

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-12-17

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

  4. Expression of Recombinant Streptokinase from Streptococcus Pyogenes and its Reaction with Infected Human and Murine Sera

    Science.gov (United States)

    Molaee, Neda; Abtahi, Hamid; Mosayebi, Ghasem

    2013-01-01

    Objective(s): Streptokinase (SKa) is an antigenic protein which is secreted by Streptococcus pyogenes. Streptokinase induces inflammation by complement activation, which may play a role in post infectious diseases. In the present study, recombinant streptokinase from S. pyogenes was produced and showed that recombinant SKa protein was recognized by infected human sera using Western blot analysis. Materials and Methods: In this study, the ska gene from S. pyogenes was amplified and cloned into pET32a which is a prokaryotic expression vector. pET32a-ska was transformed to Escherichia coli BL21 (DE3) pLysS and gene expression was induced by IPTG. Protein production was improved by modification of composition of the bacterial culture media and altering the induction time by IPTG. The expressed protein was purified by affinity chromatography using the Ni-NTA resin. The integrity of the product was confirmed by Westernblot analysis using infected mice. Serum reactivity of five infected individuals was further analyzed against the recombinant SKa protein. Results: Data indicated that recombinant SKa protein from S. pyogenes can be recognized by patient and mice sera. The concentration of the purified recombinant protein was 3.2 mg/L of initial culture. The highest amount of the expressed protein after addition of IPTG was obtained in a bacterial culture without glucose with the culture optical density of 0.8 (OD600 = 0.8). Conclusion : Present data shows, recombinant SKa protein has same epitopes with natural form of this antigen. Recombinant SKa also seemed to be a promising antigen for the serologic diagnosis of S. pyogenes infections. PMID:24171077

  5. Expression of Recombinant Streptokinase from Streptococcus Pyogenes and Its Reaction with Infected Human and Murine Sera

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    Neda Molaee

    2013-09-01

    Full Text Available   Objective(s: Streptokinase (SKa is an antigenic protein which is secreted by Streptococcus pyogenes. Streptokinase induces inflammation by complement activation, which may play a role in post infectious diseases. In the present study, recombinant streptokinase from S. pyogenes was produced and showed that recombinant SKa protein was recognized by infected human sera using Western blot analysis.   Materials and Methods: In this study, the ska gene from S. pyogenes was amplified and cloned into pET32a which is a prokaryotic expression vector. pET32a-ska was transformed to Escherichia coli BL21 (DE3 pLysS and gene expression was induced by IPTG. Protein production was improved by modification of composition of the bacterial culture media and altering the induction time by IPTG. The expressed protein was purified by affinity chromatography using the Ni-NTA resin. The integrity of the product was confirmed by Westernblot analysis using infected mice. Serum reactivity of five infected individuals was further analyzed against the recombinant SKa protein. Results: Data indicated that recombinant SKa protein from S. pyogenes can be recognized by patient and mice sera. The concentration of the purified recombinant protein was 3.2 mg/L of initial culture. The highest amount of the expressed protein after addition of IPTG was obtained in a bacterial culture without glucose with the culture optical density of 0.8 (OD600 = 0.8. Conclusion : Present data shows, recombinant SKa protein has same epitopes with natural form of this antigen. Recombinant SKa also seemed to be a promising antigen for the serologic diagnosis of S. pyogenes infections.

  6. Streptococcus pyogenes degrades extracellular matrix in chondrocytes via MMP-13

    International Nuclear Information System (INIS)

    Sakurai, Atsuo; Okahashi, Nobuo; Maruyama, Fumito; Ooshima, Takashi; Hamada, Shigeyuki; Nakagawa, Ichiro

    2008-01-01

    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

  7. Protein F, a fibronectin-binding protein, is an adhesin of the group A streptococcus Streptococcus pyogenes.

    Science.gov (United States)

    Hanski, E; Caparon, M

    1992-07-01

    Binding to fibronectin has been suggested to play an important role in adherence of the group A streptococcus Streptococcus pyrogenes 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. The gene encoding protein F (prtF) produced a functional fibronectin-binding protein in Escherichia coli. Insertional mutagenesis of the cloned gene generated a mutation that resulted in the loss of fibronectin-binding activity. When this mutation was introduced into the S. pyrogenes chromosome by homologous recombination with the wild-type allele, the resulting strains no longer produced protein F and lost their ability to bind fibronectin. The mutation could be complemented by prtF introduced on a plasmid. Mutants lacking protein F had a much lower capacity to adhere to respiratory epithelial cells. These results demonstrate that protein F is an important adhesin of S. pyogenes.

  8. The surgical team as a source of postoperative wound infections caused by Streptococcus pyogenes

    DEFF Research Database (Denmark)

    Kolmos, H J; Svendsen, R N; Nielsen, S V

    1997-01-01

    Postoperative wound infection, caused by Streptococcus pyogenes transmitted during the operation from members of the surgical team, is a rare but serious complication of surgery. This study describes three cases, which could be traced to an orthopaedic surgeon, who carried the epidemic strain...... surgeons and obstetricians. In outbreaks where an attack rate could be calculated, it was at least 7%. T-28 was the most commonly involved T-type, accounting for seven outbreaks. The anus and vagina were the most common carrier sites in staff members. A combination of penicillin and oral vancomycin seemed...

  9. SENSIBILIDAD ANTIMICROBIANA CAUSADA POR EL Streptococcus Pyogenes EN MUESTRAS DE CULTIVO DE EXUDADO FARÍNGEO

    OpenAIRE

    Solórzano Solórzano, Stalin Lorenzo; Universidad Técnica de Machala, El Oro – Ecuador

    2016-01-01

    El Streptococcus pyogenes es uno de los de los gérmenes patógenos más frecuentes, causante de enfermedades supurativas y no supurativas; son la causa más habitual de faringitis bacteriana y constituye una de las mayores causas de enfermedad infecciosa relacionada con morbi-mortalidad en todo el mundo. Después de un período de incubación de 2 a 4 días; el aislamiento del microorganismo causal en el exudado faríngeo no implica necesariamente su patogenicidad; y  es necesaria la demostración de ...

  10. The ScpC Protease of Streptococcus pyogenes Affects the Outcome of Sepsis in a Murine Model ▿

    Science.gov (United States)

    Sjölinder, Hong; Lövkvist, Lena; Plant, Laura; Eriksson, Jens; Aro, Helena; Jones, Allison; Jonsson, Ann-Beth

    2008-01-01

    The ScpC protease of Streptococcus pyogenes degrades interleukin-8 (IL-8), a chemokine that mediates neutrophil transmigration and activation. The ability to degrade IL-8 differs dramatically among clinical isolates of S. pyogenes. Bacteria expressing ScpC overcome immune clearance by preventing the recruitment of neutrophils in soft tissue infection of mice. To study the role of ScpC in streptococcal sepsis, we generated an ScpC mutant that did not degrade IL-8 and thus failed to prevent the recruitment of immune cells as well as to cause disease after soft tissue infection. In a murine model of sepsis, challenge with the ScpC mutant resulted in more severe systemic disease with higher bacteremia levels and mortality than did challenge with the wild-type strain. As expected, the blood level of KC, the murine IL-8 homologue, increased in mice infected with the ScpC mutant. However, the elevated KC levels did not influence neutrophil numbers in blood, as it did in soft tissue, indicating that additional factors contributed to neutrophil transmigration in blood. In addition, the absence of ScpC increased tumor necrosis factor, IL-6, and C5a levels in blood, which contributed to disease severity. Thus, the ScpC mutant triggers high neutrophil infiltration but not lethal outcome after soft tissue infection, whereas intravenous infection leads to highly aggressive systemic disease. PMID:18573900

  11. The ScpC protease of Streptococcus pyogenes affects the outcome of sepsis in a murine model.

    Science.gov (United States)

    Sjölinder, Hong; Lövkvist, Lena; Plant, Laura; Eriksson, Jens; Aro, Helena; Jones, Allison; Jonsson, Ann-Beth

    2008-09-01

    The ScpC protease of Streptococcus pyogenes degrades interleukin-8 (IL-8), a chemokine that mediates neutrophil transmigration and activation. The ability to degrade IL-8 differs dramatically among clinical isolates of S. pyogenes. Bacteria expressing ScpC overcome immune clearance by preventing the recruitment of neutrophils in soft tissue infection of mice. To study the role of ScpC in streptococcal sepsis, we generated an ScpC mutant that did not degrade IL-8 and thus failed to prevent the recruitment of immune cells as well as to cause disease after soft tissue infection. In a murine model of sepsis, challenge with the ScpC mutant resulted in more severe systemic disease with higher bacteremia levels and mortality than did challenge with the wild-type strain. As expected, the blood level of KC, the murine IL-8 homologue, increased in mice infected with the ScpC mutant. However, the elevated KC levels did not influence neutrophil numbers in blood, as it did in soft tissue, indicating that additional factors contributed to neutrophil transmigration in blood. In addition, the absence of ScpC increased tumor necrosis factor, IL-6, and C5a levels in blood, which contributed to disease severity. Thus, the ScpC mutant triggers high neutrophil infiltration but not lethal outcome after soft tissue infection, whereas intravenous infection leads to highly aggressive systemic disease.

  12. Antibiotic susceptibility in Streptococcus pneumoniae, Haemophilus influenzae and Streptococcus pyogenes in Pakistan: a review of results from the Survey of Antibiotic Resistance (SOAR) 2002-15.

    Science.gov (United States)

    Zafar, A; Hasan, R; Nizamuddin, S; Mahmood, N; Mukhtar, S; Ali, F; Morrissey, I; Barker, K; Torumkuney, D

    2016-05-01

    To investigate changes in the antibiotic susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Streptococcus pyogenes from the Survey of Antibiotic Resistance (SOAR) in community-acquired respiratory tract infections (CA-RTIs) between 2002 and 2015 in Pakistan. This is a review based on previously published studies from 2002-03, 2004-06 and 2007-09 and also new data from 2014-15. Susceptibility was determined by Etest(®) or disc diffusion according to CLSI and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints. A total of 706 isolates from CA-RTIs comprising 381 S. pneumoniae, 230 H. influenzae and 95 S. pyogenes were collected between 2002 and 2015 and tested against a range of antibiotics. Antibiotic resistance in S. pneumoniae rose steeply from 2002 to 2009, with isolates non-susceptible to penicillin and macrolides increasing from 10% to 34.1% and from 13%-14% to 29.7%, respectively. Susceptibility to amoxicillin/clavulanic acid (and by inference amoxicillin) remained between 99.4% and 100% from 2002 to 2015. Over the years, the prevalence of susceptibility to cefuroxime was 98%-100% among S. pneumoniae. Resistance in S. pneumoniae to some older antibiotics between 2007 and 2009 was high (86.8% for trimethoprim/sulfamethoxazole and 57.2% for tetracycline). Between 2002 and 2015, ampicillin resistance (β-lactamase-positive strains) among H. influenzae has remained low (between 2.6% and 3.2%) and almost unchanged over the years (H. influenzae was not tested during 2004-06). For S. pyogenes isolates, macrolide resistance reached 22%; however, susceptibility to penicillin, amoxicillin/clavulanic acid and cefuroxime remained stable at 100%. In S. pneumoniae from Pakistan, there has been a clear reduction in susceptibility to key antibiotics since 2002, but not to amoxicillin/clavulanic acid (amoxicillin) or cefuroxime. However, susceptibility in H. influenzae has remained stable. Local antibiotic susceptibility/resistance data are essential to

  13. Parotiditis por Streptococcus Pyogenes: Presentacion de un caso

    Directory of Open Access Journals (Sweden)

    Zoila del S. López-Díaz

    1995-08-01

    Full Text Available La glándula parótida es generalmente afectada por procesos inflamatorios. Su etiología se debe a infecciones primarias de la glándula o como complicación de infecciones sistémicas. Se reporta el Stafilococcus aureus como el agente causal más frecuente de parotiditis aguda supurada, y se señalan además otras bacterias y virus. Se presenta un niño de 9 años de edad con un proceso supurativo agudo de la parótida izquierda de un mes de evolución, con salida de abundante pus por el conducto de Stenon. Se realizó cultivo de la secreción e identificación de Streptococcus B hemolítico grupo A, a pesar de haber recibido antibioticoterapia previa. Se utilizó ampicillina y se tuvo en cuenta la sensibilidad in vitro; no presentó mejoría clínica, por lo que se decidió el empleo de la sialografía como alternativa terapéutica en este caso. Se obtuvo la resolución del proceso supurativo infeccioso y además se evidenció en este estudio la pérdida del estroma parotídeo.

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

    Science.gov (United States)

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

    2014-12-01

    Group A Streptococcus (GAS) is a well-known cause of vulvovaginitis in prepubescent girls, but it is rarely described in adult women. We describe the case of a 64-year-old woman who presented with endometritis revealed by GAS bacteraemia, followed by recurrent vulvovaginitis due to a wild-type strain of GAS. She relapsed twice despite amoxicillin treatment. Her husband was found to be an asymptomatic carrier after GAS was identified in nasal and rectal swabs. She was cured after eradication of carriage in both herself and her husband with amoxicillin and rifampin. When recurrent Streptococcus pyogenes genital infections occur, test and treat the partner. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    Science.gov (United States)

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

    2016-01-01

    emm typing is the most widely used molecular typing method for the human pathogen Streptococcus pyogenes (group A streptococcus [GAS]). emm typing is based on a small variable region of the emm gene; however, the emm cluster typing system defines GAS types according to the nearly complete sequence of the emm gene. Therefore, emm cluster typing is considered to provide more information regarding the functional and structural properties of M proteins in different emm types of GAS. In the present study, 677 isolates collected between 1994 and 2008 in a hospital in southern Taiwan were analyzed by the emm cluster typing system. emm clusters A-C4, E1, E6, and A-C3 were the most prevalent emm cluster types and accounted for 67.4% of total isolates. emm clusters A-C4 and E1 were associated with noninvasive diseases, whereas E6 was significantly associated with both invasive and noninvasive manifestations. In addition, emm clusters D4, E2, and E3 were significantly associated with invasive manifestations. Furthermore, we found that the functional properties of M protein, including low fibrinogen-binding and high IgG-binding activities, were correlated significantly with invasive manifestations. In summary, the present study provides updated epidemiological information on GAS emm cluster types in southern Taiwan. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. A case of descending mediastinitis caused by Streptococcus pyogenes harboring genotype emm25 and sequence type 660.

    Science.gov (United States)

    Ohya, Hiroaki; Mori, Nobuaki; Hayashi, Tetsuro; Minami, Shujiro; Higuchi, Akiko; Takahashi, Takashi

    2017-06-01

    Descending mediastinitis caused by Streptococcus pyogenes (group A streptococcus, GAS) is rare among cases of invasive GAS infection. In this report, we describe a case of a cervical abscess and secondary descending mediastinitis in a previously healthy 39-year-old Japanese man. The patient presented with a 2-week history of a sore throat, and subsequently developed an abscess and descending mediastinitis. We treated the cervical abscess using ampicillin/sulbactam and drainage, and GAS was subsequently isolated in two blood cultures from the patient's admission. Microbiological analyses revealed that the isolate harbored genotype emm25 and sequence type (ST) 660. This strain was susceptible to erythromycin (minimum inhibitory concentration [MIC]: ≤0.12 μg/mL), resistant to minocycline (MIC: >4 μg/mL), and possessed the tet(M) determinant. Although we have reviewed the literature regarding the clinical and microbiological characteristics of descending mediastinitis cause by GAS, little is known regarding epidemiological and clinical characteristics of emm25/ST660 GAS. Furthermore, to best of our knowledge, this is the first reported case of descending mediastinitis caused by emm25/ST660 GAS. Therefore, physicians should be aware of case with a cervical abscess and secondary descending mediastinitis caused by GAS infection, even if the patient is immunocompetent. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Cusumano, Zachary T.; Watson, Michael E.

    2014-01-01

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

  18. Purification, crystallization and preliminary crystallographic analysis of the minor pilin FctB from Streptococcus pyogenes

    International Nuclear Information System (INIS)

    Linke, Christian; Young, Paul G.; Kang, Hae Joo; Proft, Thomas; Baker, Edward N.

    2010-01-01

    The minor pilin FctB from S. pyogenes strain 90/306S was expressed in E. coli, purified and crystallized. The hexagonal FctB crystals diffracted to 2.9 Å resolution. The minor pilin FctB is an integral part of the pilus assembly expressed by Streptococcus pyogenes. Since it is located at the cell wall, it can be hypothesized that it functions as a cell-wall anchor for the streptococcal pilus. In order to elucidate its structure, the genes for FctB from the S. pyogenes strains 90/306S and SF370 were cloned for overexpression in Escherichia coli. FctB from strain 90/306S was crystallized by the sitting-drop vapour-diffusion method using sodium citrate as a precipitant. The hexagonal FctB crystals belonged to space group P6 1 or P6 5 , with unit-cell parameters a = b = 95.15, c = 100.25 Å, and diffracted to 2.9 Å resolution

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

    Science.gov (United States)

    Wong, Samson SY; Yuen, Kwok-Yung

    2012-01-01

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

  20. Two-Component Systems Involved in Susceptibility to Nisin A in Streptococcus pyogenes.

    Science.gov (United States)

    Kawada-Matsuo, Miki; Tatsuno, Ichiro; Arii, Kaoru; Zendo, Takeshi; Oogai, Yuichi; Noguchi, Kazuyuki; Hasegawa, Tadao; Sonomoto, Kenji; Komatsuzawa, Hitoshi

    2016-10-01

    Two-component systems (TCSs) are regulatory systems in bacteria that play important roles in sensing and adapting to the environment. In this study, we systematically evaluated the roles of TCSs in the susceptibility of the group A Streptococcus (GAS; Streptococcus pyogenes) SF370 strain to several types of lantibiotics. Using individual TCS deletion mutants, we found that the deletion of srtRK (spy_1081-spy_1082) in SF370 increased the susceptibility to nisin A, which is produced by Lactococcus lactis ATCC 11454, but susceptibility to other types of lantibiotics (nukacin ISK-1, produced by Staphylococcus warneri, and staphylococcin C55, produced by Staphylococcus aureus) was not altered in the TCS mutants tested. The expression of srtFEG (spy_1085 to spy_1087), which is located downstream of srtRK and is homologous to ABC transporters, was increased in response to nisin A. However, srtEFG expression was not induced by nisin A in the srtRK mutant. The inactivation of srtFEG increased the susceptibility to nisin A. These results suggest that SrtRK controls SrtFEG expression to alter the susceptibility to nisin A. Further experiments showed that SrtRK is required for coexistence with L. lactis ATCC 11454, which produces nisin A. Our results elucidate the important roles of S. pyogenes TCSs in the interactions between different bacterial species, including bacteriocin-producing bacteria. In this study, we focused on the association of TCSs with susceptibility to bacteriocins in S. pyogenes SF370, which has no ability to produce bacteriocins, and reported two major new findings. We demonstrated that the SrtRK TCS is related to susceptibility to nisin A by controlling the ABC transporter SrtFEG. We also showed that S. pyogenes SrtRK is important for survival when the bacteria are cocultured with nisin A-producing Lactococcus lactis This report highlights the roles of TCSs in the colocalization of bacteriocin-producing bacteria and non-bacteriocin-producing bacteria. Our

  1. Streptococcus pyogenes strains in Sao Paulo, Brazil: molecular characterization as a basis for StreptInCor coverage capacity analysis.

    Science.gov (United States)

    Freschi de Barros, Samar; De Amicis, Karine Marafigo; Alencar, Raquel; Smeesters, Pierre Robert; Trunkel, Ariel; Postól, Edilberto; Almeida Junior, João Nóbrega; Rossi, Flavia; Pignatari, Antonio Carlos Campos; Kalil, Jorge; Guilherme, Luiza

    2015-08-05

    Several human diseases are caused by Streptococcus pyogenes, ranging from common infections to autoimmunity. Characterization of the most prevalent strains worldwide is a useful tool for evaluating the coverage capacity of vaccines under development. In this study, a collection of S. pyogenes strains from Sao Paulo, Brazil, was analyzed to describe the diversity of strains and assess the vaccine coverage capacity of StreptInCor. Molecular epidemiology of S. pyogenes strains was performed by emm-genotyping the 229 isolates from different clinical sites, and PCR was used for superantigen profile analysis. The emm-pattern and tissue tropism for these M types were also predicted and compared based on the emm-cluster classification. The strains were fit into 12 different emm-clusters, revealing a diverse phylogenetic origin and, consequently, different mechanisms of infection and escape of the host immune system. Forty-eight emm-types were distinguished in 229 samples, and the 10 most frequently observed types accounted for 69 % of all isolates, indicating a diverse profile of circulating strains comparable to other countries under development. A similar proportion of E and A-C emm-patterns were observed, whereas pattern D was less frequent, indicating that the strains of this collection primarily had a tissue tropism for the throat. In silico analysis of the coverage capacity of StreptInCor, an M protein-conserved regionally based vaccine candidate developed by our group, had a range of 94.5 % to 59.7 %, with a mean of 71.0 % identity between the vaccine antigen and the predicted amino acid sequence of the emm-types included here. This is the first report of S. pyogenes strain characterization in Sao Paulo, one of the largest cities in the world; thus, the strain panel described here is a representative sample for vaccine coverage capacity analysis. Our results enabled evaluation of StreptInCor candidate vaccine coverage capacity against diverse M-types, indicating

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

    Science.gov (United States)

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

    2013-05-31

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

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

    Science.gov (United States)

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

    2013-12-01

    Streptococcus pyogenes (group A streptococcus, GAS) is a major cause of necrotizing soft tissue infection (NSTI). On rare occasions, other β-haemolytic streptococci may also cause NSTI, but the significance and nature of these infections has not been thoroughly investigated. In this study, clinical and molecular characteristics of NSTI caused by GAS and β-haemolytic Streptococcus dysgalactiae subsp. equisimilis of groups C and G (GCS/GGS) in western Norway during 2000-09 are presented. Clinical data were included retrospectively. The bacterial isolates were subsequently emm typed and screened for the presence of genes encoding streptococcal superantigens. Seventy cases were identified, corresponding to a mean annual incidence rate of 1.4 per 100 000. Sixty-one of the cases were associated with GAS, whereas GCS/GGS accounted for the remaining nine cases. The in-hospital case fatality rates of GAS and GCS/GGS disease were 11% and 33%, respectively. The GCS/GGS patients were older, had comorbidities more often and had anatomically more superficial disease than the GAS patients. High age and toxic shock syndrome were associated with mortality. The Laboratory Risk Indicator for Necrotizing Fasciitis laboratory score showed high values (≥6) in only 31 of 67 cases. Among the available 42 GAS isolates, the most predominant emm types were emm1, emm3 and emm4. The virulence gene profiles were strongly correlated to emm type. The number of superantigen genes was low in the four available GCS/GGS isolates. Our findings indicate a high frequency of streptococcal necrotizing fasciitis in our community. GCS/GGS infections contribute to the disease burden, but differ from GAS cases in frequency and predisposing factors. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

  4. Invasieve infecties door beta-haemolytische Streptokokken Lancefield Groep A (Streptococcus pyogenes, GAS) in Nederland, 1992-1993

    NARCIS (Netherlands)

    Schellekens JFP; Schouls LM; van Silfhout A; Elzenaar CP; Brunings HA; Blokpoel MCJ; Top J; van Leeuwen WJ; LBA; MMB

    1994-01-01

    In recent years an increase of severe invasive infections and toxic shock syndrome (TSS) with beta-haemolytic Group A streptococci (Streptococcus pyogenes, GAS) has been reported from North-America and North-Western Europe. In the spring of 1992 several reports of cases suggested that this epidemic

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

    DEFF Research Database (Denmark)

    Mortensen, Rasmus; Nissen, Thomas Nørrelykke; Fredslund, Sine

    2016-01-01

    No commercial vaccine exists against Group A streptococci (GAS; Streptococcus pyogenes) and only little is known about anti-GAS protective immunity. In our effort to discover new protective vaccine candidates, we selected 21 antigens based on an in silico evaluation. These were all well...

  6. Chronic plaque psoriasis: streptococcus pyogenes throat carriage rate and therapeutic response to oral antibiotics in comparison with oral methotrexate

    International Nuclear Information System (INIS)

    Raza, N.; Usman, M.; Hameed, A.

    2007-01-01

    To determine the throat carriage rate of Streptococcus pyogenes in patients having chronic plaque psoriasis and the effect of antibiotics as compared with that of oral methotrexate. Forty patients and 40 age and gender-matched controls were selected. Throat swab for culture of Streptococcus pyogenes was taken from each patient and control. All patients were treated with oral Penicillin V 250 mg, 6 hourly, and oral Rifampicin, 600 mg daily, for 10 days. Pre- and post therapy 'Psoriasis Area and Severity Index' (PASI) were compared. Thirty of these 40 patients were later given oral methotrexate, 5-10 mg weekly, for 04 weeks and pre- and post-therapy PASI were compared. Chi-square and paired-samples t-test were used for data analysis. Throat swab cultures were positive for Streptococcus pyogenes in 05 (12.5%) patients and none (0%) of the controls (p=0.02). Mean pre- and postantibiotic therapy PASI were 15.92 + 05.94 and 15.19 + 06.17 respectively (p=0.078). Mean pre- and postmethotrexate PASI were 15.81+ 5.55 and 8.79 + 4.19 respectively (p <0.01). Throat carriage of Streptococcus pyogenes is common in patients with chronic plaque psoriasis. Short-term antibiotic treatment has no role in routine treatment of chronic plaque psoriasis. However, it would be worthwhile to consider the effects of long term antibiotics on chronic plaque psoriasis. (author)

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

    Science.gov (United States)

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

    2016-02-01

    Gram-positive Streptococcus pyogenes (group A Streptococcus or GAS) is a major skin pathogen and interacts with keratinocytes in cutaneous tissues. GAS can cause diverse suppurative and inflammatory infections, such as cellulitis, a common acute bacterial dermo-hypodermitis with a high morbidity. Bacterial isolation yields from the lesions are low despite the strong local inflammation observed, raising numerous questions about the pathogenesis of the infection. Using an in vitro model of GAS-infected keratinocytes, we show that the major ROS produced is the superoxide anion ([Formula: see text]), and that its production is time- and dose-dependent. Using specific modulators of ROS production, we show that [Formula: see text] is mainly synthesized by the cytoplasmic NADPH oxidase. Superoxide anion production leads to keratinocyte necrosis but incomplete inhibition of GAS growth, suggesting that GAS may be partially resistant to the oxidative burst. In conclusion, GAS-stimulated keratinocytes are able to develop an innate immune response based on the production of ROS. This local immune response limits GAS development and induces keratinocyte cell death, resulting in the skin lesions observed in patients with cellulitis. © The Author(s) 2015.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  10. Scarlet fever is caused by a limited number of Streptococcus pyogenes lineages and is associated with the exotoxin genes ssa, speA and speC.

    Science.gov (United States)

    Silva-Costa, Catarina; Carriço, Joao A; Ramirez, Mario; Melo-Cristino, Jose

    2014-03-01

    Several outbreaks of scarlet fever caused by Streptococcus pyogenes were recently reported. Scarlet fever is historically considered a toxin-mediated disease, dependent on the production of the exotoxins SpeA and SpeC, but a strict association between scarlet fever and these exotoxins is not always detected. The aims of this study were to characterize the scarlet fever bacterial isolates recovered from patients in a Lisbon hospital and to identify any distinctive characteristics of such isolates. We characterized a collection of 303 pharyngeal S. pyogenes collected between 2002 and 2008. One-hundred and one were isolated from scarlet fever patients and 202 were associated to a diagnosis of tonsillo-pharyngitis. Isolates were characterized by T and emm typing, pulsed field gel electrophoresis profiling and superantigen gene profiling. The diversity of the scarlet fever isolates was lower than that of the pharyngitis isolates. Specific lineages of emm87, emm4 and emm3 were overrepresented in scarlet fever isolates but only 1 pulsed field gel electrophoresis major lineage was significantly associated with scarlet fever. Multivariate analysis indicated associations of ssa, speA and speC with scarlet fever. In nonoutbreak conditions, scarlet fever is caused by a number of distinct genetic lineages. The lower diversity of these isolates and the association with specific exotoxin genes indicates that some lineages are more prone to cause this presentation than others even in nonoutbreak conditions.

  11. Variation in Streptococcus pyogenes NAD+ glycohydrolase is associated with tissue tropism.

    Science.gov (United States)

    Riddle, David J; Bessen, Debra E; Caparon, Michael G

    2010-07-01

    Streptococcus pyogenes is an important pathogen that causes a variety of diseases. The most common infections involve the throat (pharyngitis) or skin (impetigo); however, the factors that determine tissue tropism and severity are incompletely understood. The S. pyogenes NAD(+) glycohydrolase (SPN) is a virulence factor that has been implicated in contributing to the pathogenesis of severe infections. However, the role of SPN in determining the bacterium's tissue tropism has not been evaluated. In this report, we examine the sequences of spn and its endogenous inhibitor ifs from a worldwide collection of S. pyogenes strains. Analysis of average pairwise nucleotide diversity, average number of nucleotide differences, and ratio of nonsynonymous to synonymous substitutions revealed significant diversity in spn and ifs. Application of established models of molecular evolution shows that SPN is evolving under positive selection and diverging into NAD(+) glycohydrolase (NADase)-active and -inactive subtypes. Additionally, the NADase-inactive SPN subtypes maintain the characteristics of a functional gene while ifs becomes a pseudogene. Thus, NADase-inactive SPN continues to evolve under functional constraint. Furthermore, NADase activity did not correlate with invasive disease in our collection but was associated with tissue tropism. The ability to cause infection at both the pharynx and the skin ("generalist" strains) is correlated with NADase-active SPN, while the preference for causing infection at either the throat or the skin ("specialist" strains) is associated with NADase-inactive SPN. These findings suggest that SPN has a NADase-independent function and prompt a reevaluation of the role of SPN in streptococcal pathogenesis.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ji Young; An, Doo Ri; Yoon, Hye-Jin [Seoul National University, Seoul 151-747 (Korea, Republic of); Kim, Hyoun Sook [Seoul National University, Seoul 151-747 (Korea, Republic of); Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, Sang Jae [Seoul National University, Seoul 151-742 (Korea, Republic of); Im, Ha Na; Jang, Jun Young [Seoul National University, Seoul 151-747 (Korea, Republic of); Suh, Se Won, E-mail: sewonsuh@snu.ac.kr [Seoul National University, Seoul 151-747 (Korea, Republic of); Seoul National University, Seoul 151-747 (Korea, Republic of)

    2013-11-01

    The crystal structure of the complex between the C-terminal domain of Streptococcus pyogenes β-NAD{sup +} glycohydrolase and an endogenous inhibitor for SPN was determined at 1.70 Å. It reveals that the interface between the two proteins is highly rich in water molecules. One of the virulence factors produced by Streptococcus pyogenes is β-NAD{sup +} 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 SPN{sub ct}–IFS complex, which consists of the SPN C-terminal domain (SPN{sub ct}; 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 SPN{sub ct} 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.

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

    International Nuclear Information System (INIS)

    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

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

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

    Science.gov (United States)

    Totolian, A A

    2015-01-01

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

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

    Science.gov (United States)

    Ludlam, H; Cookson, B

    1986-08-09

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

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

    Science.gov (United States)

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

    2015-10-01

    The M protein of Streptococcus pyogenes, a major bacterial virulence factor, has an amino-terminal hypervariable region (HVR) that is a target for type-specific protective antibodies. Intriguingly, the HVR elicits a weak antibody response, indicating that it escapes host immunity by two mechanisms, sequence variability and weak immunogenicity. However, the properties influencing the immunogenicity of regions in an M protein remain poorly understood. Here, we studied the antibody response to different regions of the classical M1 and M5 proteins, in which not only the HVR but also the adjacent fibrinogen-binding B repeat region exhibits extensive sequence divergence. Analysis of antisera from S. pyogenes-infected patients, infected mice, and immunized mice showed that both the HVR and the B repeat region elicited weak antibody responses, while the conserved carboxy-terminal part was immunodominant. Thus, we identified a correlation between sequence variability and weak immunogenicity for M protein regions. A potential explanation for the weak immunogenicity was provided by the demonstration that protease digestion selectively eliminated the HVR-B part from whole M protein-expressing bacteria. These data support a coherent model, in which the entire variable HVR-B part evades antibody attack, not only by sequence variability but also by weak immunogenicity resulting from protease attack. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    Succinic semialdehyde dehydrogenase (SSADH) from S. pyogenes was purified and crystallized. Crystals of native and NAD + -complexed SSADH diffracted to resolutions of 1.6 and 1.7 Å, respectively. Succinic semialdehyde dehydrogenase (SSADH) plays a critical role in the metabolism of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) and catalyzes the NAD(P) + -coupled oxidation of succinic semialdehyde (SSA) to succinic acid (SA). SSADH from Streptococcus pyogenes has been purified and crystallized as the apoenzyme and in a complex with NAD + . The crystals of native and NAD + -complexed SSADH diffracted to resolutions of 1.6 and 1.7 Å, respectively, using a synchrotron-radiation source. Both crystals belonged to the orthorhombic space group P2 1 2 1 2 1 , 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 Å 3 Da −1 and a solvent content of 48.0%

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    The putative adhesion domain of the multidomain protein Epf from S. pyogenes has been crystallized in space groups P2 1 and P2 1 2 1 2 1 . The crystals diffracted to 2.0 and 1.6 Å resolution, respectively, at the Australian Synchrotron. The extracellular protein Epf from Streptococcus pyogenes is important for streptococcal adhesion to human epithelial cells. However, Epf has no sequence identity to any protein of known structure or function. Thus, several predicted domains of the 205 kDa protein Epf were cloned separately and expressed in Escherichia coli. The N-terminal domain of Epf was crystallized in space groups P2 1 and P2 1 2 1 2 1 in the presence of the protease chymotrypsin. Mass spectrometry showed that the species crystallized corresponded to a fragment comprising residues 52–357 of Epf. Complete data sets were collected to 2.0 and 1.6 Å resolution, respectively, at the Australian Synchrotron

  20. Expression, purification and crystallization of the C-terminal LRR domain of Streptococcus pyogenes protein 0843

    International Nuclear Information System (INIS)

    Haikarainen, Teemu; Loimaranta, Vuokko; Prieto-Lopez, Carlos; Battula, Pradeep; Finne, Jukka; Papageorgiou, Anastassios C.

    2013-01-01

    The C-terminal LRR domain of S. pyogenes protein 0843 was overexpressed in E. coli, purified and crystallized. A complete data set to 1.59 Å resolution was collected using synchrotron radiation. Streptococcus pyogenes protein 0843 (Spy0843) is a recently identified protein with a potential adhesin function. Sequence analysis has shown that Spy0843 contains two leucine-rich repeat (LRR) domains that mediate interactions with the gp340 receptor. Here, the C-terminal LRR domain was overexpressed in Escherichia coli, purified and crystallized in the presence of 1.7–1.8 M ammonium sulfate pH 7.4 as precipitant. Data were collected from a single crystal to 1.59 Å resolution at 100 K at a synchrotron-radiation source. The crystal was found to belong to space group I4 1 , with unit-cell parameters a = b = 121.4, c = 51.5 Å and one molecule in the asymmetric unit. Elucidation of the crystal structure will provide insights into the interactions of Spy0843 with the gp340 receptor and a better understanding of the role of Spy0843 in streptococcal infections

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

    Science.gov (United States)

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

    2015-10-01

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

  2. Importance of whole genome sequencing for the assessment of outbreaks in diagnostic laboratories: analysis of a case series of invasive Streptococcus pyogenes infections.

    Science.gov (United States)

    Tagini, F; Aubert, B; Troillet, N; Pillonel, T; Praz, G; Crisinel, P A; Prod'hom, G; Asner, S; Greub, G

    2017-07-01

    Outbreaks of Streptococcus pyogenes hypervirulent clones are constant public health threats. In western Switzerland, an increase of severe cases of S. pyogenes invasive infections was observed between December 2015 and March 2016. Our aim was (i) to investigate these cases by the use of Whole Genome Sequencing (WGS) and (ii) to determine the specific virulome and resistome of each isolate in order to undertake adequate public health measures. Eleven Streptococcus pyogenes strains isolated from 11 patients with severe invasive infections between December 13, 2015 and March 12, 2016 were included in our study. Practically, emm-typing, MLST and WGS were used to investigate the relatedness between the isolates. The presence of virulence and antibiotic resistance genes as well as mutations in transcriptional regulators of virulence and in genes encoding for antibiotic targets were assessed. Three and two groups of isolates shared the same emm-type and ST type, respectively. Single Nucleotide Polymorphism (SNP) analysis revealed 14 to 32 SNPs between the strains of the same emm-type group, ruling out the possibility of a clonal outbreak. Mutations found in covS and rocA could partially explain an increased virulence. As these reassuring results were obtained in less than 10 days, no specific hospital hygiene and no dedicated public health measures had to be undertaken. WGS is a powerful technique to discriminate between closely related strains, excluding an outbreak in less than 10 days. Moreover, WGS provided extensive data on the virulome and resistome of all these strains.

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

    DEFF Research Database (Denmark)

    Diehl, Carl; Wisniewska, Magdalena; Frick, Inga-Maria

    2016-01-01

    Streptococcus pyogenes is one of the most significant bacterial pathogens in the human population mostly causing superficial and uncomplicated infections (pharyngitis and impetigo) but also invasive and life-threatening disease. We have previously identified a virulence determinant, protein s......HIP, which is secreted at higher levels by an invasive compared to a non-invasive strain of S. pyogenes. The present work presents a further characterization of the structural and functional properties of this bacterial protein. Biophysical and structural studies have shown that protein sHIP forms stable...

  4. The hypervariable region of Streptococcus pyogenes M protein escapes antibody attack by antigenic variation and weak immunogenicity

    DEFF Research Database (Denmark)

    Lannergård, Jonas; Gustafsson, Caj Ulrik Mattias; Waldemarsson, Johan

    2011-01-01

    , we analyzed the clinically important HVR-containing M proteins of the human pathogen Streptococcus pyogenes. Antibodies elicited by M proteins were directed almost exclusively against the C-terminal part and not against the N-terminal HVR. Similar results were obtained for mice and humans...... with invasive S. pyogenes infection. Nevertheless, only anti-HVR antibodies protected efficiently against infection, as shown by passive immunizations. The HVR fused to an unrelated protein elicited no antibodies, implying that it is inherently weakly immunogenic. These data indicate that the M protein HVR...

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

    Science.gov (United States)

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

    2014-06-27

    Streptococcus pyogenes is a significant bacterial pathogen in the human population. The importance of virulence factors for the survival and colonization of S. pyogenes is well established, and many of these factors are exposed to the extracellular environment, enabling bacterial interactions with the host. In the present study, we quantitatively analyzed and compared S. pyogenes proteins in the growth medium of a strain that is virulent to mice with a non-virulent strain. Particularly, one of these proteins was present at significantly higher levels in stationary growth medium from the virulent strain. We determined the three-dimensional structure of the protein that showed a unique tetrameric organization composed of four helix-loop-helix motifs. Affinity pull-down mass spectrometry analysis in human plasma demonstrated that the protein interacts with histidine-rich glycoprotein (HRG), and the name sHIP (streptococcal histidine-rich glycoprotein-interacting protein) is therefore proposed. HRG has antibacterial activity, and when challenged by HRG, sHIP was found to rescue S. pyogenes bacteria. This and the finding that patients with invasive S. pyogenes infection respond with antibody production against sHIP suggest a role for the protein in S. pyogenes pathogenesis. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-03-15

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

  8. Potential antibiotic and anti-infective effects of rhodomyrtone from Rhodomyrtus tomentosa (Aiton) Hassk. on Streptococcus pyogenes as revealed by proteomics

    NARCIS (Netherlands)

    Limsuwan, Surasak; Voravuthikunchai, Supayang Piyawan; van Dijl, Jan Maarten; Kayser, Oliver; Meinders, Hesseling A.

    2011-01-01

    Rhodomyrtone from Rhodomyrtus tomentosa (Aiton) Hassk. leaf extract has a strong antibacterial activity against the bacterial pathogen Streptococcus pyogenes. Our previous studies indicated that the bactericidal activity of rhodomyrtone might involve intracellular targets. In the present studies we

  9. Properties and antimicrobial susceptibility of Trueperella pyogenes isolated from bovine mastitis in China.

    Science.gov (United States)

    Alkasir, Rashad; Wang, Jianfang; Gao, Jian; Ali, Tariq; Zhang, Limei; Szenci, Ottó; Bajcsy, Árpád Csaba; Han, Bo

    2016-03-01

    Trueperella (T.) pyogenes is an opportunistic pathogen that causes suppurative diseases in domestic animals. In this work, the properties, pathogenesis and phenotypic diversity of T. pyogenes isolates from bovine mastitis were studied. Both pyolysin (plo) and collagen-binding protein (cbp) virulence factor genes were detected by PCR in all T. pyogenes isolates (n = 50). Using the tissue culture plate method, 90% of T. pyogenes isolates were able to form biofilms. The minimum inhibitory concentrations (MICs) of 13 antimicrobials against T. pyogenes isolates were determined. High susceptibility was observed to rifampin (96%), ampicillin (94%), ciprofloxacin (94%), and penicillin (92%), while low susceptibility was found to trimethoprim-sulphamethoxazole (10%) and bacitracin (2%). The intracellular assay revealed that T. pyogenes isolates had different cytopathogenic effects on cells. The high percentage (28.6%) of T. pyogenes isolates suggests that this bacterium is an important contributor to mastitis. Moreover, the high occurrence of multidrug resistance, biofilm production, intracellular survival, and the temporal dynamics of T. pyogenes interactions are key factors for a better understanding of how immunity acts on infections with these bacteria and how they evade immune surveillance, thus highlighting the need for the prudent use of antimicrobial agents in veterinary medicine.

  10. Emergence of Streptococcus pyogenes emm102 causing toxic shock syndrome in Southern Taiwan during 2005-2012.

    Directory of Open Access Journals (Sweden)

    Jiun-Nong Lin

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

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

    Science.gov (United States)

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

    2016-05-01

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

  12. Lactobacilli interfere with Streptococcus pyogenes hemolytic activity and adherence to host epithelial cells

    Directory of Open Access Journals (Sweden)

    Sunil D Saroj

    2016-07-01

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

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

    Science.gov (United States)

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

    2016-01-01

    Group A Streptococcus (GAS, Streptococcus pyogenes) is a human-restricted pathogen with a capacity to both colonize asymptomatically and cause illnesses ranging from pharyngitis to necrotizing fasciitis. An understanding of how and when GAS switches between genetic programs governing these different lifestyles has remained an enduring mystery and likely requires carefully tuned environmental sensors to activate and silence genetic schemes when appropriate. Herein, we describe the relationship between the Control of Virulence (CovRS, CsrRS) two-component system and the Rgg2/3 quorum-sensing pathway. We demonstrate that responses of CovRS to the stress signals Mg(2+) and a fragment of the antimicrobial peptide LL-37 result in modulated activity of pheromone signaling of the Rgg2/3 pathway through a means of proteolysis of SHP peptide pheromones. This degradation is mediated by the cytoplasmic endopeptidase PepO, which is the first identified enzymatic silencer of an RRNPP-type quorum-sensing pathway. These results suggest that under conditions in which the virulence potential of GAS is elevated (i.e. enhanced virulence gene expression), cellular responses mediated by the Rgg2/3 pathway are abrogated and allow individuals to escape from group behavior. These results also indicate that Rgg2/3 signaling is instead functional during non-virulent GAS lifestyles. © 2015 John Wiley & Sons Ltd.

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

    Science.gov (United States)

    Young, Christie A; Gordon, Lily D; Fang, Zhong; Holder, Robert C; Reid, Sean D

    2015-08-01

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

  15. Investigation of antibacterial activities of Albizia gummifera and Ferula communis on Streptococcus pneumoniae and Streptoccus pyogenes.

    Science.gov (United States)

    Unasho, Abayneh; Geyid, Aberra; Melaku, Abebe; Debela, Asfaw; Mekasha, Amha; Girma, Samson; Kebede, Tesfaye; Fantaw, Surafael; Asaminew, Nega; Mamo, Kidanemariam

    2009-01-01

    Respiratory Tract infections continue to be a major cause of morbidity and mortality world wide. There is a failure to treat respiratory infections due to the emergence of antibiotic resistant strains among the most common respiratory pathogens. To evaluate the in vitro antibacterial activities of two traditionally used plants: Albizia gummifera (Ambabesa-Muka, Oromifa, Sessa-Amharic.) and Ferula communis (Doge-Oromifa, Dog-Amharic) against clinical isolates of S. pyogenes and S. pneumoniae. The study involving the antibacterial susceptibility test of traditionally used plant species against Gram-positive bacterial pathogens was conducted over a period of 5 months (January - August, 2004) at the Ethiopian Health, and Nutrition Research Institute. The in vitro antibacterial activities of 80% methanol crude extracts prepared from the seeds of Ablizia gummifera and, roots of Ferula communis as well as their respective hydro alcoholic solvent fractionates of both plant species were tested for inhibitory activity against the clinical isolates of six S. pneumonae and twenty two S. pyogenes using agar dilution method. Eighty percent ethanol solubilized fractions of both plants were found to have antibacterial effects to all assayed bacteria while aqueous solubilized fractions did not exhibit any effect. Minimum inhibitory concentration (MIC) of the 80% ethanol solubilized fractions was determined and the MIC of the fractions ranged from 500 mg/ ml to 1000 mg/ml for both plants showing the extracts may contain bioactive compounds of therapeutic interest. All extracts showed antibacterial activities against clinical isolates of S. pyogenes and S. pneumoniae. The extracts may contain compounds with potential therapeutic activity. Further purification and identification are needed to be tested using animal models.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  18. Factor H binds to the hypervariable region of many Streptococcus pyogenes M proteins but does not promote phagocytosis resistance or acute virulence.

    Directory of Open Access Journals (Sweden)

    Mattias C U Gustafsson

    Full Text Available 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.

  19. Identification of a two-component Class IIb bacteriocin in Streptococcus pyogenes by recombinase-based in vivo expression technology

    Science.gov (United States)

    Armstrong, Brent D.; Herfst, Christine A.; Tonial, Nicholas C.; Wakabayashi, Adrienne T.; Zeppa, Joseph J.; McCormick, John K.

    2016-01-01

    Streptococcus pyogenes is a globally prominent bacterial pathogen that exhibits strict tropism for the human host, yet bacterial factors responsible for the ability of S. pyogenes to compete within this limited biological niche are not well understood. Using an engineered recombinase-based in vivo expression technology (RIVET) system, we identified an in vivo-induced promoter region upstream of a predicted Class IIb bacteriocin system in the M18 serotype S. pyogenes strain MGAS8232. This promoter element was not active under in vitro laboratory conditions, but was highly induced within the mouse nasopharynx. Recombinant expression of the predicted mature S. pyogenes bacteriocin peptides (designated SpbM and SpbN) revealed that both peptides were required for antimicrobial activity. Using a gain of function experiment in Lactococcus lactis, we further demonstrated S. pyogenes immunity function is encoded downstream of spbN. These data highlight the importance of bacterial gene regulation within appropriate environments to help understand mechanisms of niche adaptation by bacterial pathogens. PMID:27808235

  20. Epidemiological study of erythromycin-resistant Streptococcus pyogenes from Korea and Japan by emm genotyping and multilocus sequence typing.

    Science.gov (United States)

    Takahashi, Takashi; Arai, Kazuaki; Lee, Dong Hyun; Koh, Eun Ha; Yoshida, Haruno; Yano, Hisakazu; Kaku, Mitsuo; Kim, Sunjoo

    2016-01-01

    We determined the epidemiological characteristics of erythromycin (EM)-resistant Streptococcus pyogenes (group A streptococci, GAS) strains isolated from Korea and Japan, using emm genotyping and multilocus sequence typing (MLST). Clinical isolates of GAS had been collected from 1992 to 2012 in Korea and from 2004 to 2009 in Japan. EM resistance was determined by the microdilution method, and resistance genotypes were assessed by PCR. The emm genotyping and MLST were performed by DNA sequencing. The emm genotypes and sequence types (STs) were concordant in 143 (85.1%) of 168 EM-resistant GAS strains from Korea. ST36/emm12 (35.1%), ST52/emm28 (22.6%), and ST49/emm75 (16.1%) were the most common types. Most of the ST36 (93.9%) and ST52 (95.8%) strains harbored erm(B), whereas strains ST49, ST42, and ST15 contained mef(A). The concordance between emm genotypes and STs was 41 (93.2%) among 44 EM-resistant GAS strains from Japan. ST36/emm12 (34.1%), ST49/emm75 (18.2%), and ST28/emm1 (15.9%) were the major types. ST36 isolates harbored either erm(B) (56.3%) or mef(A) (37.5%), whereas isolates ST28, ST49, and ST38 carried only mef(A). The proportion of erm(B) and mef(A) was 66.1% and 33.3% in Korea and 22.7% and 68.2% in Japan, respectively. The common STs in Korea and Japan were ST36 and ST49, whereas ST52 was present only in Korea and ST28 only in Japan. Genotype erm(B) was predominant in Korea, whereas mef(A) was frequent in Japan. There were differences between Korea and Japan regarding the frequencies of emm genotypes, STs, and EM resistance genes among the EM-resistant GAS.

  1. Identification and Characterization of Fluoroquinolone Non-susceptible Streptococcus pyogenes Clones Harboring Tetracycline and Macrolide Resistance in Shanghai, China

    Science.gov (United States)

    Shen, Yinfang; Cai, Jiehao; Davies, Mark R.; Zhang, Chi; Gao, Kun; Qiao, Dan; Jiang, Haoqin; Yao, Weilei; Li, Yuefang; Zeng, Mei; Chen, Mingliang

    2018-01-01

    Streptococcus pyogenes, also known as group A Streptococcus (GAS), is one of the top 10 infectious causes of death worldwide. Macrolide and tetracycline resistant GAS has emerged as a major health concern in China coinciding with an ongoing scarlet fever epidemic. Furthermore, increasing rates of fluoroquinolone (FQ) non-susceptibility within GAS from geographical regions outside of China has also been reported. Fluoroquinolones are the third most commonly prescribed antibiotic in China and is an therapeutic alternative for multi-drug resistant GAS. The purpose of this study was to investigate the epidemiological and molecular features of GAS fluoroquinolone (FQ) non-susceptibility in Shanghai, China. GAS (n = 2,258) recovered between 2011 and 2016 from children and adults were tested for FQ-non-susceptibility. Efflux phenotype and mutations in parC, parE, gyrA, and gyrB were investigated and genetic relationships were determined by emm typing, pulsed-field gel electrophoresis and phylogenetic analysis. The frequency of GAS FQ-non-susceptibility was 1.3% (30/2,258), with the phenotype more prevalent in GAS isolated from adults (14.3%) than from children (1.2%). Eighty percent (24/30) of FQ-non-susceptible isolates were also resistant to both macrolides (ermB) and tetracycline (tetM) including the GAS sequence types emm12, emm6, emm11, and emm1. Genomic fingerprinting analysis of the 30 isolates revealed that non-susceptibility may arise in various genetic backgrounds even within a single emm type. No efflux phenotype was observed in FQ non-susceptible isolates, and molecular analysis of the quinolone resistance-determining regions (QRDRs) identified several sequence polymorphisms in ParC and ParE, and none in GyrA and GyrB. Expansion of this analysis to 152 publically available GAS whole genome sequences from Hong Kong predicted 7.9% (12/152) of Hong Kong isolates harbored a S79F ParC mutation, of which 66.7% (8/12) were macrolide and tetracycline resistant

  2. Identification and Characterization of Fluoroquinolone Non-susceptible Streptococcus pyogenes Clones Harboring Tetracycline and Macrolide Resistance in Shanghai, China

    Directory of Open Access Journals (Sweden)

    Yinfang Shen

    2018-03-01

    Full Text Available Streptococcus pyogenes, also known as group A Streptococcus (GAS, is one of the top 10 infectious causes of death worldwide. Macrolide and tetracycline resistant GAS has emerged as a major health concern in China coinciding with an ongoing scarlet fever epidemic. Furthermore, increasing rates of fluoroquinolone (FQ non-susceptibility within GAS from geographical regions outside of China has also been reported. Fluoroquinolones are the third most commonly prescribed antibiotic in China and is an therapeutic alternative for multi-drug resistant GAS. The purpose of this study was to investigate the epidemiological and molecular features of GAS fluoroquinolone (FQ non-susceptibility in Shanghai, China. GAS (n = 2,258 recovered between 2011 and 2016 from children and adults were tested for FQ-non-susceptibility. Efflux phenotype and mutations in parC, parE, gyrA, and gyrB were investigated and genetic relationships were determined by emm typing, pulsed-field gel electrophoresis and phylogenetic analysis. The frequency of GAS FQ-non-susceptibility was 1.3% (30/2,258, with the phenotype more prevalent in GAS isolated from adults (14.3% than from children (1.2%. Eighty percent (24/30 of FQ-non-susceptible isolates were also resistant to both macrolides (ermB and tetracycline (tetM including the GAS sequence types emm12, emm6, emm11, and emm1. Genomic fingerprinting analysis of the 30 isolates revealed that non-susceptibility may arise in various genetic backgrounds even within a single emm type. No efflux phenotype was observed in FQ non-susceptible isolates, and molecular analysis of the quinolone resistance-determining regions (QRDRs identified several sequence polymorphisms in ParC and ParE, and none in GyrA and GyrB. Expansion of this analysis to 152 publically available GAS whole genome sequences from Hong Kong predicted 7.9% (12/152 of Hong Kong isolates harbored a S79F ParC mutation, of which 66.7% (8/12 were macrolide and tetracycline resistant

  3. Infección y colonización faríngea asintomática de niños por Streptococcus pyogenes = Streptococcus pyogenes infection and asymptomatic throat carriage in children

    Directory of Open Access Journals (Sweden)

    Acuña Ramos, Clara Patricia

    2012-07-01

    Full Text Available Objetivo: establecer la frecuencia de estreptococo beta hemolítico del grupo A (Streptococcus pyogenes en niños, mediante una prueba rápida de inmunoensayo cromatográfico.Métodos: estudio piloto de tipo transversal en una muestra no probabilística de 144 niños entre 3 y 13 años, asistentes a centros infantiles de Medellín y su área metropolitana y a una institución educativa de Bogotá. Se tomaron muestras de garganta por frotis para la prueba rápida de S. pyogenes y se recolectó información demográfica y de antecedentes personales mediante una encuesta. Se calcularon los promedios con sus desviaciones estándar y los porcentajes de acuerdo con la naturaleza de las variables de interés.Resultados: la edad promedio del grupo fue 5,5 ± 2,8 años con distribución similar por sexo. Veintiún niños (14,6% fueron positivos para S. pyogenes, diez de ellos fueron posibles infecciones y 11, portadores asintomáticos. De los 144 niños, 45 (31,3% tenían síntomas faríngeos, de los cuales 10 (22,2% tenían S. pyogenes. Un total de 99 (68,8% niños fueron asintomáticos y 11 de estos (11,1% presentaron prueba positiva para S. pyogenes.Discusión: la alta frecuencia de S. pyogenes en este grupo es un llamado de atención sobre la necesidad de implementar protocolos de manejo con pruebas rápidas para la detección del microorganismo.

  4. SENSITIZATION TO STREPTOCOCCUS PYOGENES AT CHILDREN OF EARLY AND PRESCHOOL AGE WITH RECURRENT RESPIRATORY INFECTIONS — PREDICTORS OF RHEUMATIC PATHOLOGY

    Directory of Open Access Journals (Sweden)

    E. V. Shabaldina

    2015-01-01

    Full Text Available Streptococcus pyogenes is the reason of rheumatism and a post-streptococcal glomerulonephritis. Primary colonization of mucosal with this microorganism develops in the period of early ontogenesis. It was confirmed that at a carriage of this microorganism children at them activate immunopathological reactions. Clinic and immune features of the children with recurrent respiratory infections of early and preschool age having the immune response to S. pyogenes were studied. Position of risk of formation of rheumatic diseases at these children was studied. 771 children, in an age interval of 2–6 years are examined. Immune and clinical indicators in two groups of the children having the immune response to S. pyogenes (n = 306 and not having it (n = 465 were analyzed. It was shown that in group of the children with immune response to S. pyogenes were authentically higher: point of an hereditary predisposition, expressiveness of placental insufficiency and a fetal hypoxia during the real pregnancy, and in the post-natal period degree of a thymomegaly, a pharyngeal lymphoid ring hypertrophy, skin manifestations of food allergy on the first year of life, the frequency of sharp respiratory infections within one year — in comparison with control. The group of the children having the immune response to S. pyogenes had a high level in a nasal secret of TNFα, IL-4, IFNα, and in blood — ASL-O, ASG, RF, CRP and immunoglobulin E. It was shown that at the children with a sensitization to S. pyogenes were lowered in peripheral blood: the general leukocytes, lymphocytes, T-lymphocytes (CD3 positive, T-helpery (CD3 and CD4 positive, an immunoregulatory index (the relation of CD4 of positive lymphocytes to CD8 to positive lymphocytes, phagocytosis (in test with nitro blue tetrazolium chloride — NBT and immunoglobulin A — in comparison with control. The atopic immune response to S. pyogenes, S. pneumoniae, S. aureus, P. vulgaris, K. pneumoniae, H

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

    Science.gov (United States)

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

    2015-12-25

    Streptococcus pyogenes is an important human pathogen that causes a wide range of diseases. Using bioinformatics analysis of the complete S. pyogenes strain SF370 genome, we have identified a novel S. pyogenes virulence factor, which we termed streptococcal 5'-nucleotidase A (S5nA). A recombinant form of S5nA hydrolyzed AMP and ADP, but not ATP, to generate the immunomodulatory molecule adenosine. Michaelis-Menten kinetics revealed a Km of 169 μm and a Vmax of 7550 nmol/mg/min for the substrate AMP. Furthermore, recombinant S5nA acted synergistically with S. pyogenes nuclease A to generate macrophage-toxic deoxyadenosine from DNA. The enzyme showed optimal activity between pH 5 and pH 6.5 and between 37 and 47 °C. Like other 5'-nucleotidases, S5nA requires divalent cations and was active in the presence of Mg(2+), Ca(2+), or Mn(2+). However, Zn(2+) inhibited the enzymatic activity. Structural modeling combined with mutational analysis revealed a highly conserved catalytic dyad as well as conserved substrate and cation-binding sites. Recombinant S5nA significantly increased the survival of the non-pathogenic bacterium Lactococcus lactis during a human whole blood killing assay in a dose-dependent manner, suggesting a role as an S. pyogenes virulence factor. In conclusion, we have identified a novel S. pyogenes enzyme with 5'-nucleotidase activity and immune evasion properties. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Superantigenic activity of emm3 Streptococcus pyogenes is abrogated by a conserved, naturally occurring smeZ mutation.

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    Claire E Turner

    Full Text Available Streptococcus pyogenes M/emm3 strains have been epidemiologically linked with enhanced infection severity and risk of streptococcal toxic shock syndrome (STSS, a syndrome triggered by superantigenic stimulation of T cells. Comparison of S. pyogenes strains causing STSS demonstrated that emm3 strains were surprisingly less mitogenic than other emm-types (emm1, emm12, emm18, emm28, emm87, emm89 both in vitro and in vivo, indicating poor superantigenic activity. We identified a 13 bp deletion in the superantigen smeZ gene of all emm3 strains tested. The deletion led to a premature stop codon in smeZ, and was not present in other major emm-types tested. Expression of a functional non-M3-smeZ gene successfully enhanced mitogenic activity in emm3 S. pyogenes and also restored mitogenic activity to emm1 and emm89 S. pyogenes strains where the smeZ gene had been disrupted. In contrast, the M3-smeZ gene with the 13 bp deletion could not enhance or restore mitogenicity in any of these S. pyogenes strains, confirming that M3-smeZ is non-functional regardless of strain background. The mutation in M3-smeZ reduced the potential for M3 S. pyogenes to induce cytokines in human tonsil, but not during invasive infection of superantigen-sensitive mice. Notwithstanding epidemiological associations with STSS and disease severity, emm3 strains have inherently poor superantigenicity that is explained by a conserved mutation in smeZ.

  7. Extreme sequence divergence but conserved ligand-binding specificity in Streptococcus pyogenes M protein.

    Directory of Open Access Journals (Sweden)

    2006-05-01

    Full Text Available Many pathogenic microorganisms evade host immunity through extensive sequence variability in a protein region targeted by protective antibodies. In spite of the sequence variability, a variable region commonly retains an important ligand-binding function, reflected in the presence of a highly conserved sequence motif. Here, we analyze the limits of sequence divergence in a ligand-binding region by characterizing the hypervariable region (HVR of Streptococcus pyogenes M protein. Our studies were focused on HVRs that bind the human complement regulator C4b-binding protein (C4BP, a ligand that confers phagocytosis resistance. A previous comparison of C4BP-binding HVRs identified residue identities that could be part of a binding motif, but the extended analysis reported here shows that no residue identities remain when additional C4BP-binding HVRs are included. Characterization of the HVR in the M22 protein indicated that two relatively conserved Leu residues are essential for C4BP binding, but these residues are probably core residues in a coiled-coil, implying that they do not directly contribute to binding. In contrast, substitution of either of two relatively conserved Glu residues, predicted to be solvent-exposed, had no effect on C4BP binding, although each of these changes had a major effect on the antigenic properties of the HVR. Together, these findings show that HVRs of M proteins have an extraordinary capacity for sequence divergence and antigenic variability while retaining a specific ligand-binding function.

  8. Preclinical safety study of a recombinant Streptococcus pyogenes vaccine formulated with aluminum adjuvant.

    Science.gov (United States)

    HogenEsch, Harm; Dunham, Anisa; Burlet, Elodie; Lu, Fangjia; Mosley, Yung-Yi C; Morefield, Garry

    2017-02-01

    A recombinant vaccine composed of a fusion protein formulated with aluminum hydroxide adjuvant is under development for protection against diseases caused by Streptococcus pyogenes. The safety and local reactogenicity of the vaccine was assessed by a comprehensive series of clinical, pathologic and immunologic tests in preclinical experiments. Outbred mice received three intramuscular injections of 1/5th of the human dose (0.1 ml) and rabbits received two injections of the full human dose. Control groups received adjuvant or protein antigen. The vaccine did not cause clinical evidence of systemic toxicity in mice or rabbits. There was a transient increase of peripheral blood neutrophils after the third vaccination of mice. In addition, the concentration of acute phase proteins serum amyloid A and haptoglobin was significantly increased 1 day after injection of the vaccine in mice. There was mild transient swelling and erythema of the injection site in both mice and rabbits. Treatment-related pathology was limited to inflammation at the injection site and accumulation of adjuvant-containing macrophages in the draining lymph nodes. In conclusion, the absence of clinical toxicity in two animal species suggest that the vaccine is safe for use in a phase I human clinical trial. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

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

    International Nuclear Information System (INIS)

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

    1988-01-01

    Expulsion of preaccumulated methyl-β-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 [ 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 [ 14 C]TMG. Since net efflux was nearly arrested when the external concentration of [ 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa, E-mail: m.tuzen@gmail.com [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Uluozlu, Ozgur Dogan [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Karaman, Isa [Gaziosmanpasa University, Faculty of Science and Arts, Biology Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)

    2009-09-30

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    Science.gov (United States)

    Zhu, Luchang; Olsen, Randall J; Nasser, Waleed; de la Riva Morales, Ivan; Musser, James M

    2015-10-06

    Strains of emm89 Streptococcus pyogenes have become one of the major causes of invasive infections worldwide in the last 10 years. We recently sequenced the genome of 1,125 emm89 strains and identified three major phylogenetic groups, designated clade 1, clade 2, and the epidemic clade 3. Epidemic clade 3 strains, which now cause the great majority of infections, have two distinct genetic features compared to clade 1 and clade 2 strains. First, all clade 3 organisms have a variant 3 nga promoter region pattern, which is associated with increased production of secreted cytolytic toxins SPN (S. pyogenes NADase) and SLO (streptolysin O). Second, all clade 3 strains lack the hasABC locus mediating hyaluronic acid capsule synthesis, whereas this locus is intact in clade 1 and clade 2 strains. We constructed isogenic mutant strains that produce different levels of SPN and SLO toxins and capsule (none, low, or high). Here we report that emm89 strains with elevated toxin production are significantly more virulent than low-toxin producers. Importantly, we also show that capsule production is dispensable for virulence in strains that already produce high levels of SPN and SLO. Our results provide new understanding about the molecular mechanisms contributing to the rapid emergence and molecular pathogenesis of epidemic clade 3 emm89 S. pyogenes. S. pyogenes (group A streptococcus [GAS]) causes pharyngitis ("strep throat"), necrotizing fasciitis, and other human infections. Serious infections caused by emm89 S. pyogenes strains have recently increased in frequency in many countries. Based on whole-genome sequence analysis of 1,125 strains recovered from patients on two continents, we discovered that a new emm89 clone, termed clade 3, has two distinct genetic features compared to its predecessors: (i) absence of the genes encoding antiphagocytic hyaluronic acid capsule virulence factor and (ii) increased production of the secreted cytolytic toxins SPN and SLO. emm89 S. pyogenes

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

    Science.gov (United States)

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

    2011-01-01

    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

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

    Science.gov (United States)

    Tatsuno, Ichiro; Isaka, Masanori; Okada, Ryo; Zhang, Yan; Hasegawa, Tadao

    2014-03-28

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

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

    Science.gov (United States)

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

    2016-08-20

    Genome-scale metabolic models comprise stoichiometric relations between metabolites, as well as associations between genes and metabolic reactions and facilitate the analysis of metabolism. We computationally reconstructed the metabolic network of the lactic acid bacterium Streptococcus pyogenes M49. Initially, we based the reconstruction on genome annotations and already existing and curated metabolic networks of Bacillus subtilis, Escherichia coli, Lactobacillus plantarum and Lactococcus lactis. This initial draft was manually curated with the final reconstruction accounting for 480 genes associated with 576 reactions and 558 metabolites. In order to constrain the model further, we performed growth experiments of wild type and arcA deletion strains of S. pyogenes M49 in a chemically defined medium and calculated nutrient uptake and production fluxes. We additionally performed amino acid auxotrophy experiments to test the consistency of the model. The established genome-scale model can be used to understand the growth requirements of the human pathogen S. pyogenes and define optimal and suboptimal conditions, but also to describe differences and similarities between S. pyogenes and related lactic acid bacteria such as L. lactis in order to find strategies to reduce the growth of the pathogen and propose drug targets. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Nina Gratz

    2011-05-01

    Full Text Available 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.

  17. Production of bacteriocin-like inhibitory substances (BLIS by Streptococcus salivarius strains isolated from the tongue and throat of children with and without sore throat Produção de substâncias inibidoras semelhantes à bacteriocina por cepas de Streptococcus salivarius, isoladas da língua e garganta de crianças com e sem dor de garganta

    Directory of Open Access Journals (Sweden)

    Vera Fantinato

    1999-12-01

    Full Text Available Streptococcus salivarius strains, isolated from children with and without sore throat, were tested for bacteriocin production against Streptococcus pyogenes. S. salivarius strains producing bacteriocin-like inhibitory substances (BLIS against S. pyogenes were more frequently found in children without sore throat. These results suggest that these children may be protected against sore throat by the presence of BLIS-positive S. salivarius strains.Cepas de Streptococcus salivarius, isoladas de crianças com e sem dor de garganta, foram testadas quanto à produção de bacteriocina contra Streptococcus pyogenes. Os resultados mostraram que as crianças que não tinham dor de garganta possuiam, na boca, cepas de bactérias produtoras de substâncias inibidoras semelhantes à bacteriocina contra S. pyogenes.

  18. Emergence of high-level fluoroquinolone resistance in emm6 Streptococcus pyogenes and in vitro resistance selection with ciprofloxacin, levofloxacin and moxifloxacin.

    Science.gov (United States)

    Malhotra-Kumar, Surbhi; Van Heirstraeten, Liesbet; Lammens, Christine; Chapelle, Sabine; Goossens, Herman

    2009-05-01

    To investigate the prevalence of fluoroquinolone resistance in Streptococcus pyogenes and its in vitro selection by ciprofloxacin and the respiratory fluoroquinolones, levofloxacin and moxifloxacin. S. pyogenes (n = 5851) recovered from pharyngitis and invasive infections during 2003-06 in Belgium were screened for fluoroquinolone non-susceptibility (ciprofloxacin MIC > or =2 mg/L) and further studied for mutations in the topoisomerase genes, reserpine-sensitive efflux, clonality by PFGE and emm typing. Fourteen well-characterized fluoroquinolone-non-susceptible or -susceptible isolates were exposed stepwise to increasing levels of ciprofloxacin, levofloxacin and moxifloxacin. Selected mutants with increased MICs were analysed for resistance mechanisms. Mutation frequencies at 2x and 4x MIC of moxifloxacin and levofloxacin were estimated for a clinical emm6 parent strain carrying mutations in both parC and gyrA. Prevalence of fluoroquinolone-non-susceptible S. pyogenes (n = 437; 7.47%) increased significantly from 2.08% and 5.08% to 13.11% during 2003-05 and decreased to 8.93% in 2006 (chi(2) test; P fluoroquinolone-non-susceptible isolates. Of the 71 S. pyogenes sequenced, 70 harboured first-step parC or gyrA mutations correlating with ciprofloxacin MICs 2-8 mg/L. Reserpine-sensitive efflux was not observed. One emm6parC mutant (Ser79Ala) also showed a second-step mutation in gyrA (Ser81Tyr), with MICs of ciprofloxacin, levofloxacin and moxifloxacin of 32, 8 and 1 mg/L, respectively. Mean mutation frequencies under moxifloxacin selection were 500- to 30 000-fold higher for this strain than those for an emm6 control strain. Selection of the emm6 double mutant with moxifloxacin generated a mutant with a moxifloxacin MIC of 64 mg/L and a levofloxacin MIC of 128 mg/L, and an additional Asp83Tyr substitution in ParC. We report an emergence of levofloxacin and high-level ciprofloxacin resistance associated with a second-step gyrA mutation in a clinical emm6 S. pyogenes

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  20. Single- and multistep resistance selection studies on the activity of retapamulin compared to other agents against Staphylococcus aureus and Streptococcus pyogenes.

    Science.gov (United States)

    Kosowska-Shick, Klaudia; Clark, Catherine; Credito, Kim; McGhee, Pamela; Dewasse, Bonifacio; Bogdanovich, Tatiana; Appelbaum, Peter C

    2006-02-01

    Retapamulin had the lowest rate of spontaneous mutations by single-step passaging and the lowest parent and selected mutant MICs by multistep passaging among all drugs tested for all Staphylococcus aureus strains and three Streptococcus pyogenes strains which yielded resistant clones. Retapamulin has a low potential for resistance selection in S. pyogenes, with a slow and gradual propensity for resistance development in S. aureus.

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

    Science.gov (United States)

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

    2014-10-01

    The linkage between the macrolide efflux gene mef(I) and the chloramphenicol inactivation gene catQ was first described in Streptococcus pneumoniae (strain Spn529), where the two genes are located in a module designated IQ element. Subsequently, two different defective IQ elements were detected in Streptococcus pyogenes (strains Spy029 and Spy005). The genetic elements carrying the three IQ elements were characterized, and all were found to be Tn5253 family integrative and conjugative elements (ICEs). The ICE from S. pneumoniae (ICESpn529IQ) was sequenced, whereas the ICEs from S. pyogenes (ICESpy029IQ and ICESpy005IQ, the first Tn5253-like ICEs reported in this species) were characterized by PCR mapping, partial sequencing, and restriction analysis. ICESpn529IQ and ICESpy029IQ were found to share the intSp 23FST81 integrase gene and an identical Tn916 fragment, whereas ICESpy005IQ has int5252 and lacks Tn916. All three ICEs were found to lack the linearized pC194 plasmid that is usually associated with Tn5253-like ICEs, and all displayed a single copy of a toxin-antitoxin operon that is typically contained in the direct repeats flanking the excisable pC194 region when this region is present. Two different insertion sites of the IQ elements were detected, one in ICESpn529IQ and ICESpy029IQ, and another in ICESpy005IQ. The chromosomal integration of the three ICEs was site specific, depending on the integrase (intSp 23FST81 or int5252). Only ICESpy005IQ was excised in circular form and transferred by conjugation. By transformation, mef(I) and catQ were cotransferred at a high frequency from S. pyogenes Spy005 and at very low frequencies from S. pneumoniae Spn529 and S. pyogenes Spy029. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  2. Differential compartmentalization of Streptococcus pyogenes virulence factors and host protein binding properties as a mechanism for host adaptation.

    Science.gov (United States)

    Kilsgård, Ola; Karlsson, Christofer; Malmström, Erik; Malmström, Johan

    2016-11-01

    Streptococcus pyogenes is an important human pathogen responsible for substantial morbidity and mortality worldwide. Although S. pyogenes is a strictly human pathogen with no other known animal reservoir, several murine infection models exist to explore different aspects of the bacterial pathogenesis. Inoculating mice with wild-type S. pyogenes strains can result in the generation of new bacterial phenotypes that are hypervirulent compared to the original inoculum. In this study, we used a serial mass spectrometry based proteomics strategy to investigate if these hypervirulent strains have an altered distribution of virulence proteins across the intracellular, surface associated and secreted bacterial compartments and if any change in compartmentalization can alter the protein-protein interaction network between bacteria and host proteins. Quantitative analysis of the S. pyogenes surface and secreted proteomes revealed that animal passaged strains are associated with significantly higher amount of virulence factors on the bacterial surface and in the media. This altered virulence factor compartmentalization results in increased binding of several mouse plasma proteins to the bacterial surface, a trend that was consistent for mouse plasma from several different mouse strains. In general, both the wild-type strain and animal passaged strain were capable of binding high amounts of human plasma proteins. However, compared to the non-passaged strains, the animal passaged strains displayed an increased ability to bind mouse plasma proteins, in particular for M protein binders, indicating that the increased affinity for mouse blood plasma proteins is a consequence of host adaptation of this pathogen to a new host. In conclusion, plotting the total amount of virulence factors against the total amount of plasma proteins associated to the bacterial surface could clearly separate out animal passaged strains from wild type strains indicating a virulence model that could

  3. Factor H-IgG Chimeric Proteins as a Therapeutic Approach against the Gram-Positive Bacterial Pathogen Streptococcus pyogenes.

    Science.gov (United States)

    Blom, Anna M; Magda, Michal; Kohl, Lisa; Shaughnessy, Jutamas; Lambris, John D; Ram, Sanjay; Ermert, David

    2017-12-01

    Bacteria can cause life-threatening infections, such as pneumonia, meningitis, or sepsis. Antibiotic therapy is a mainstay of treatment, although antimicrobial resistance has drastically increased over the years. Unfortunately, safe and effective vaccines against most pathogens have not yet been approved, and thus developing alternative treatments is important. We analyzed the efficiency of factor H (FH)6-7/Fc, a novel antibacterial immunotherapeutic protein against the Gram-positive bacterium Streptococcus pyogenes This protein is composed of two domains of complement inhibitor human FH (FH complement control protein modules 6 and 7) that bind to S. pyogenes , linked to the Fc region of IgG (FH6-7/Fc). FH6-7/Fc has previously been shown to enhance complement-dependent killing of, and facilitate bacterial clearance in, animal models of the Gram-negative pathogens Haemophilus influenzae and Neisseria meningitidis We hypothesized that activation of complement by FH6-7/Fc on the surface of Gram-positive bacteria such as S. pyogenes will enable professional phagocytes to eliminate the pathogen. We found that FH6-7/Fc alleviated S. pyogenes- induced sepsis in a transgenic mouse model expressing human FH ( S. pyogenes binds FH in a human-specific manner). Furthermore, FH6-7/Fc, which binds to protein H and selected M proteins, displaced FH from the bacterial surface, enhanced alternative pathway activation, and reduced bacterial blood burden by opsonophagocytosis in a C3-dependent manner in an ex vivo human whole-blood model. In conclusion, FH-Fc chimeric proteins could serve as adjunctive treatments against multidrug-resistant bacterial infections. Copyright © 2017 by The American Association of Immunologists, Inc.

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

    Science.gov (United States)

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

    2014-01-01

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

  5. Functional dissection of Streptococcus pyogenes M5 protein: the hypervariable region is essential for virulence.

    Directory of Open Access Journals (Sweden)

    Johan Waldemarsson

    Full Text Available The surface-localized M protein of Streptococcus pyogenes is a major virulence factor that inhibits phagocytosis, as determined ex vivo. Because little is known about the role of M protein in vivo we analyzed the contribution of different M protein regions to virulence, using the fibrinogen (Fg-binding M5 protein and a mouse model of acute invasive infection. This model was suitable, because M5 is required for mouse virulence and binds mouse and human Fg equally well, as shown here. Mixed infection experiments with wild type bacteria demonstrated that mutants lacking the N-terminal hypervariable region (HVR or the Fg-binding B-repeat region were strongly attenuated, while a mutant lacking the conserved C-repeats was only slightly attenuated. Because the HVR of M5 is not required for phagocytosis resistance, our data imply that this HVR plays a major but unknown role during acute infection. The B-repeat region is required for phagocytosis resistance and specifically binds Fg, suggesting that it promotes virulence by binding Fg. However, B-repeat mutants were attenuated even in Fg-deficient mice, implying that the B-repeats may have a second function, in addition to Fg-binding. These data demonstrate that two distinct M5 regions, including the HVR, are essential to virulence during the early stages of an infection. In particular, our data provide the first in vivo evidence that the HVR of an M protein plays a major role in virulence, focusing interest on the molecular role of this region.

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  8. mef(A), mef(E) and a new mef allele in macrolide-resistant Streptococcus spp. isolates from Norway.

    Science.gov (United States)

    Sangvik, Maria; Littauer, Pia; Simonsen, Gunnar Skov; Sundsfjord, Arnfinn; Dahl, Kristin Hegstad

    2005-11-01

    To type mef genes in a nationwide collection of clinical isolates of Streptococcus pneumoniae and Streptococcus pyogenes as well as pharyngeal carrier strains of viridans streptococci in Norway. Erythromycin-resistant mef-positive multilocus sequence-typed (MLST) clinical isolates of S. pneumoniae (n = 36) and S. pyogenes (n = 12) from the National Surveillance Program for Antimicrobial Resistance (NORM) as well as viridans streptococci (n = 20) from healthy adults were included. PCR-amplified mef genes were initially discriminated by BamHI digestion. Selected mef genes from representatives of different sequence types (STs) of S. pneumoniae (n = 11) and S. pyogenes (n = 4), and viridans group streptococcal species (n = 8) were typed by sequencing and their strains examined for co-resistances. Hydropathy plots of different mef-encoded proteins were performed. A predominance of mef(A) was detected in S. pneumoniae (23/36) and S. pyogenes (9/12) due to the clonal spread of ST9 and ST39, respectively. mef(E) was the most widely distributed mef determinant occurring in nine different STs of S. pneumoniae and in four different viridans species. A new mef allele was identified in two STs of S. pyogenes. mef(E) is the most widely distributed mef determinant in Norwegian clinical strains of S. pneumoniae and pharyngeal carrier strains of various viridans streptococci. However, mef(A) is more prevalent in S. pneumoniae and S. pyogenes due to clonal spread. A new mef allele was found in two different STs of S. pyogenes.

  9. Inhibitory role of acyl homoserine lactones in hemolytic activity and viability of Streptococcus pyogenes M6 S165

    Science.gov (United States)

    Saroj, Sunil D.; Holmer, Linda; Berengueras, Júlia M.; Jonsson, Ann-Beth

    2017-01-01

    Streptococcus pyogenes an adapted human pathogen asymptomatically colonizes the nasopharynx, among other polymicrobial communities. However, information on the events leading to the colonization and expression of virulence markers subject to interspecies and host-bacteria interactions are limited. The interference of acyl homoserine lactones (AHLs) with the hemolytic activity and viability of S. pyogenes M6 S165 was examined. AHLs, with fatty acid side chains ≥12 carbon atoms, inhibited hemolytic activity by downregulating the expression of the sag operon involved in the production of streptolysin S. Inhibitory AHLs upregulated the expression of transcriptional regulator LuxR. Electrophoretic mobility shift assays revealed the interaction of LuxR with the region upstream of sagA. AHL-mediated bactericidal activity observed at higher concentrations (mM range) was an energy-dependent process, constrained by the requirement of glucose and iron. Ferrichrome transporter FtsABCD facilitated transport of AHLs across the streptococcal membrane. The study demonstrates a previously unreported role for AHLs in S. pyogenes virulence. PMID:28303956

  10. Evaluation of the Potency, Neutralizing Antibody Response, and Stability of a Recombinant Fusion Protein Vaccine for Streptococcus pyogenes.

    Science.gov (United States)

    Burlet, E; HogenEsch, H; Dunham, A; Morefield, G

    2017-05-01

    Streptococcus pyogenes or group A streptococcus (GAS) is a Gram-positive bacterium that can cause a wide range of diseases, including pharyngitis, impetigo, scarlet fever, necrotizing fasciitis, rheumatic fever, and streptococcal toxic shock syndrome. Despite the increasing burden on global health caused by GAS, there is currently no licensed vaccine available. In this study, we evaluated immunogenicity, induction of neutralizing antibodies, and stability of a new recombinant fusion protein vaccine that targets infections from GAS. The recombinant fusion protein (SpeAB) combines inactive mutant forms of streptococcal pyrogenic exotoxin A (SpeA) and streptococcal pyrogenic exotoxin B (SpeB). The SpeAB vaccine evaluated in this study was adsorbed to an aluminum adjuvant and demonstrated robust immunogenicity, eliciting production of specific neutralizing antibodies against SpeA and SpeB, two major virulence factors of S. pyogenes. Stability studies suggest that the vaccine will retain immunogenicity for at least 2 years when stored at refrigerated temperatures. This novel vaccine shows great potential to provide protection against GAS infections and to reduce the burden of GAS disease globally.

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

    Science.gov (United States)

    Shafreen, Rajamohmed Beema; Pandian, Shunmugiah Karutha

    2013-09-01

    Streptococcus pyogenes (SP) is the major cause of pharyngitis accompanied by strep throat infections in humans. 3-keto acyl reductase (FabG), an important enzyme involved in the elongation cycle of the fatty acid pathway of S. pyogenes, is essential for synthesis of the cell-membrane, virulence factors and quorum sensing-related mechanisms. Targeting SPFabG may provide an important aid for the development of drugs against S. pyogenes. However, the absence of a crystal structure for FabG of S. pyogenes limits the development of structure-based drug designs. Hence, in the present study, a homology model of FabG was generated using the X-ray crystallographic structure of Aquifex aeolicus (PDB ID: 2PNF). The modeled structure was refined using energy minimization. Furthermore, active sites were predicted, and a large dataset of compounds was screened against SPFabG. The ligands were docked using the LigandFit module that is available from Discovery Studio version 2.5. From this list, 13 best hit ligands were chosen based on the docking score and binding energy. All of the 13 ligands were screened for Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) properties. From this, the two best descriptors, along with one descriptor that lay outside the ADMET plot, were selected for molecular dynamic (MD) simulation. In vitro testing of the ligands using biological assays further substantiated the efficacy of the ligands that were screened based on the in silico methods. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Occurrence, isolation and DNA identification of Streptococcus ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-28

    Nov 28, 2011 ... Streptococcus thermophilus isolates from traditional butter 'Smen', a fermented product from cow's ... temperature of milk. The fresh butter is removed manually in a single lump called 'Zebda' which is trans- formed into 'Smen' by washing with salt ... Egyptian artisanal butter 'zabady' was reported recently.

  13. Regulation of sagA, siaA and scpC by SilCR, a putative signaling peptide of Streptococcus pyogenes.

    Science.gov (United States)

    Salim, Kowthar Y; de Azavedo, Joyce C; Bast, Darrin J; Cvitkovitch, Dennis G

    2008-12-01

    SilCR, a 17 amino acid putative signaling peptide, was proposed to modulate gene expression in Streptococcus pyogenes. We showed that SilCR added exogenously to an M1 serotype strain lacking the sil locus upregulates the in vitro expression of sagA, siaA, and scpC, genes associated with S. pyogenes pathogenesis. Interestingly, only sagA and siaA were upregulated by SilCR in vivo, whereas the expression of scpC remained unaltered. A previous report indicated that exogenously added SilCR protects mice to some degree from developing necrotic lesions caused by an invasive strain of S. pyogenes. In contrast to this report, we found that SilCR did not reduce lesion formation in a subcutaneous murine model of S. pyogenes infection but rather appeared to delay wound healing.

  14. Cloning of the gene encoding Streptococcin A-FF22, a novel lantibiotic produced by Streptococcus pyogenes, and determination of its nucleotide sequence.

    OpenAIRE

    Hynes, W L; Ferretti, J J; Tagg, J R

    1993-01-01

    Streptococcin A-FF22 (SA-FF22) is a lantibiotic produced by Streptococcus pyogenes FF22. The nucleotide sequence of the SA-FF22 structural gene (scnA) was determined and shown to encode a 51-amino-acid prepeptide. The proteolytic processing site of the SA-FF22 prepeptide differs from that which characterizes other type A lantibiotics.

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

    DEFF Research Database (Denmark)

    Magnussen, Marita D; Gaini, Shahin; Gislason, Hannes

    2016-01-01

    The aim of this study was to investigate the antibacterial resistance of Streptococcus pyogenes (GAS), and correlate the findings with the sales of erythromycin and tetracycline. General practitioners in the Faroe Islands were recruited to send oropharyngeal swabs. From an ongoing pneumococcal...

  16. Streptococcus pyogenes CAMP factor promotes bacterial adhesion and invasion in pharyngeal epithelial cells without serum via PI3K/Akt signaling pathway.

    Science.gov (United States)

    Kurosawa, Mie; Oda, Masataka; Domon, Hisanori; Isono, Toshihito; Nakamura, Yuki; Saitoh, Issei; Hayasaki, Haruaki; Yamaguchi, Masaya; Kawabata, Shigetada; Terao, Yutaka

    2018-01-01

    Streptococcus pyogenes is a bacterium that causes systemic diseases, such as pharyngitis and toxic shock syndrome, via oral- or nasal-cavity infection. S. pyogenes produces various molecules known to function with serum components that lead to bacterial adhesion and invasion in human tissues. In this study, we identified a novel S. pyogenes adhesin/invasin. Our results revealed that CAMP factor promoted streptococcal adhesion and invasion in pharyngeal epithelial Detroit562 cells without serum. Recombinant CAMP factor initially localized on the membranes of cells and then became internalized in the cytosol following S. pyogenes infection. Additionally, CAMP factor phosphorylated phosphoinositide 3-kinase and serine-threonine kinase in the cells. ELISA results demonstrate that CAMP factor affected the amount of phosphorylated phosphoinositide 3-kinase and serine-threonine kinase in Detroit562 cells. Furthermore, CAMP factor did not reverse the effect of phosphoinositide 3-kinase knockdown by small interfering RNA in reducing the level of adhesion and invasion of S. pyogenes isogenic cfa-deficient mutant. These results suggested that S. pyogenes CAMP factor activated the phosphoinositide 3-kinase/serine-threonine kinase signaling pathway, promoting S. pyogenes invasion of Detroit562 cells without serum. Our findings suggested that CAMP factor played an important role on adhesion and invasion in pharyngeal epithelial cells. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  17. Molecular characterization and evaluation of the emerging antibiotic-resistant Streptococcus pyogenes from eastern India.

    Science.gov (United States)

    Ray, Dipanwita; Saha, Somnath; Sinha, Sukanta; Pal, Nishith Kumar; Bhattacharya, Basudev

    2016-12-12

    Group A Streptococcus strains causing wide variety of diseases, recently became noticeable in eastern India, are not amenable to standard treatment protocol thus enhancing the possibility of disease morbidity by becoming antibiotic resistance. The association of Lancefield group A Streptococcal variation with degree of vir architectural diversity was evaluated using emm typing and restriction fragment length polymorphism analyses. The antibiotic sensitivity patterns were examined by modified Kirby-Bauer method of disk diffusion. Percentage calculations, 95% confidence interval and one-way ANOVA were used to assess differences in proportions. Our observations revealed 20 different emm types and 13 different HaeIII vir typing patterns. A 1.2 kb fragment was found in all HaeIII typing pattern. Fragments of 1.2 kb and 550 bp were conserved in majority of the isolates. HinfI digestion was found proficient in differentiating the strains of same vir typing patterns. Strong predominance of speC (85%) and speF (80%) genes have been observed encoding exotoxins production. 4 isolates were found to be erythromycin resistant and were of genotype emm49. High degree of tetracycline resistance was shown by 53.57% isolates which belonged to 12 different emm genotypes. These findings suggested that in addition to emm typing, sequential application of HaeIII and HinfI restriction enzymes in vir typing analysis is an effective tool for group A streptococcal molecular characterization associated with antibiotic resistance.

  18. Association of the shuffling of Streptococcus pyogenes clones and the fluctuation of scarlet fever cases between 2000 and 2006 in central Taiwan

    Directory of Open Access Journals (Sweden)

    Wang Wan-Ling

    2009-06-01

    Full Text Available Abstract Background The number of scarlet fever occurrences reported between 2000 and 2006 fluctuated considerably in central Taiwan and throughout the nation. Isolates of Streptococcus pyogenes were collected from scarlet fever patients in central Taiwan and were characterized by emm sequencing and a standardized pulsed-field gel electrophoresis (PFGE method. National weekly report data were collected for investigating epidemiological trends. Results A total of 23 emm types were identified in 1,218 S. pyogenes isolates. The five most prevalent emm types were emm12 (50.4%, emm4 (23.2%, emm1 (16.4%, emm6 (3.8% and emm22 (3.0%. PFGE analysis with SmaI suggested that, with a few exceptions, strains with a common emm type belonged to the same clone. There were two large emm12 clones, one with DNA resistant to cleavage by SmaI. Each prevalent emm clone had major PFGE strain(s and many minor strains. Most of the minor strains emerged in the population and disappeared soon after. Even some major strains remained prevalent for only 2–3 years before declining. The large fluctuation of scarlet fever cases between 2000 and 2006 was associated with the shuffling of six prevalent emm clones. In 2003, the dramatic drop in scarlet fever cases in central Taiwan and throughout the whole country was associated with the occurrence of a severe acute respiratory syndrome (SARS outbreak that occurred between late-February and mid-June in Taiwan. Conclusion The occurrences of scarlet fever in central Taiwan in 2000–2006 were primarily caused by five emm types, which accounted for 96.8% of the isolates collected. Most of the S. pyogenes strains (as defined by PFGE genotypes emerged and lasted for only a few years. The fluctuation in the number of scarlet fever cases during the seven years can be primarily attributed to the shuffling of six prevalent emm clones and to the SARS outbreak in 2003.

  19. The CXC Chemokine-degrading Protease SpyCep of Streptococcus pyogenes Promotes Its Uptake into Endothelial Cells*

    Science.gov (United States)

    Kaur, Simran Jeet; Nerlich, Andreas; Bergmann, Simone; Rohde, Manfred; Fulde, Marcus; Zähner, Dorothea; Hanski, Emanuel; Zinkernagel, Annelies; Nizet, Victor; Chhatwal, Gursharan S.; Talay, Susanne R.

    2010-01-01

    Streptococcus pyogenes expresses the LPXTG motif-containing cell envelope serine protease SpyCep (also called ScpC, PrtS) that degrades and inactivates the major chemoattractant interleukin 8 (IL-8), thereby impairing host neutrophil recruitment. In this study, we identified a novel function of SpyCep: the ability to mediate uptake into primary human endothelial cells. SpyCep triggered its uptake into endothelial cells but not into human epithelial cells originating from pharynx or lung, indicating an endothelial cell-specific uptake mechanism. SpyCep mediated cellular invasion by an endosomal/lysosomal pathway distinct from the caveolae-mediated invasion pathway of S. pyogenes. Recombinant expression and purification of proteolytically active SpyCep and a series of subfragments allowed functional dissection of the domains responsible for endothelial cell invasion and IL-8 degradation. The N-terminal PR domain was sufficient to mediate endothelial cell invasion, whereas for IL-8-degrading activity, the protease domain and the flanking A domain were required. A polyclonal rabbit serum raised against the recombinant protease efficiently blocked the invasion-mediating activity of SpyCep but not its proteolytic function, further indicating that SpyCep-mediated internalization is independent from its enzymatic activity. SpyCep may thus specifically mediate its own uptake as secreted protein into human endothelial cells. PMID:20562101

  20. The CXC chemokine-degrading protease SpyCep of Streptococcus pyogenes promotes its uptake into endothelial cells.

    Science.gov (United States)

    Kaur, Simran Jeet; Nerlich, Andreas; Bergmann, Simone; Rohde, Manfred; Fulde, Marcus; Zähner, Dorothea; Hanski, Emanuel; Zinkernagel, Annelies; Nizet, Victor; Chhatwal, Gursharan S; Talay, Susanne R

    2010-09-03

    Streptococcus pyogenes expresses the LPXTG motif-containing cell envelope serine protease SpyCep (also called ScpC, PrtS) that degrades and inactivates the major chemoattractant interleukin 8 (IL-8), thereby impairing host neutrophil recruitment. In this study, we identified a novel function of SpyCep: the ability to mediate uptake into primary human endothelial cells. SpyCep triggered its uptake into endothelial cells but not into human epithelial cells originating from pharynx or lung, indicating an endothelial cell-specific uptake mechanism. SpyCep mediated cellular invasion by an endosomal/lysosomal pathway distinct from the caveolae-mediated invasion pathway of S. pyogenes. Recombinant expression and purification of proteolytically active SpyCep and a series of subfragments allowed functional dissection of the domains responsible for endothelial cell invasion and IL-8 degradation. The N-terminal PR domain was sufficient to mediate endothelial cell invasion, whereas for IL-8-degrading activity, the protease domain and the flanking A domain were required. A polyclonal rabbit serum raised against the recombinant protease efficiently blocked the invasion-mediating activity of SpyCep but not its proteolytic function, further indicating that SpyCep-mediated internalization is independent from its enzymatic activity. SpyCep may thus specifically mediate its own uptake as secreted protein into human endothelial cells.

  1. Bivalent mucosal peptide vaccines administered using the LCP carrier system stimulate protective immune responses against Streptococcus pyogenes infection.

    Science.gov (United States)

    Schulze, Kai; Ebensen, Thomas; Chandrudu, Saranya; Skwarczynski, Mariusz; Toth, Istvan; Olive, Colleen; Guzman, Carlos A

    2017-11-01

    Despite the broad knowledge about the pathogenicity of Streptococcus pyogenes there is still a controversy about the correlate of protection in GAS infections. We aimed in further improving the immune responses stimulated against GAS comparing different vaccine formulations including bis-(3',5')-cyclic dimeric adenosine monophosphate (c-di-AMP) and BPPCysMPEG, a derivative of the macrophage-activating lipopeptide (MALP-2), as adjuvants, respectively, to be administered with and without the universal T helper cell epitope P25 along with the optimized B cell epitope J14 of the M protein and B and T cell epitopes of SfbI. Lipopeptide based nano carrier systems (LCP) were used for efficient antigen delivery across the mucosal barrier. The stimulated immune responses were efficient in protecting mice against a respiratory challenge with a lethal dose of a heterologous S. pyogenes strain. Moreover, combination of the LCP based peptide vaccine with c-di-AMP allowed reduction of antigen dose at the same time maintaining vaccine efficacy. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2016-07-01

    In Streptococcus pyogenes, proteins involved in determining virulence are controlled by stand-alone response regulators and by two-component regulatory systems. Previous studies reported that, compared to the parental strain, the yvqE sensor knockout strain showed significantly reduced growth and lower virulence. To determine the function of YvqE, we performed biofilm analysis and pH assays on yvqE mutants, and site-directed mutagenesis of YvqE. The yvqE deletion mutant showed a slower acid production rate, indicating that YvqE regulates acid production from sugar fermentation. The mutant strain, in which the Asp(26) residue in YvqE was replaced with Asn, affected biofilm formation, suggesting that this amino acid senses hydrogen ions produced by fermentative sugar metabolism. Signals received by YvqE were directly or indirectly responsible for inducing pilus expression. This study shows that at low environmental pH, biofilm formation in S. pyogenes is mediated by YvqE and suggests that regulation of pilus expression by environmental acidification could be directly under the control of YvqE. © 2016 APMIS. Published by John Wiley & Sons Ltd.

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

    Science.gov (United States)

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

    2016-01-01

    We investigated the correlation between the genetic variation within mef(A)-msr(D) determinants of efflux-mediated erythromycin resistance in Streptococcus pyogenes and the level of erythromycin resistance. Twenty-eight mef(A)-positive strains were selected according to erythromycin MIC (4-32 μg/mL), and their mef(A)-msr(D) regions were sequenced. Strains were classified according to the bacteriophage carrying mef(A)-msr(D). A new Φm46.1 genetic variant was found in 8 strains out of 28 and named VP_00501.1. Degree of allelic variation was higher in mef(A) than in msr(D). Hotspots for recombination were mapped within the locus that could have shaped the apparent mosaic structure of the region. There was a general correlation between mef(A)-msr(D) sequence and erythromycin resistance level. However, lysogenic conversion of susceptible strains by mef(A)-msr(D)-carrying Φm46.1 indicated that key determinants may not all reside within the mef(A)-msr(D) locus and that horizontal gene transfer could contribute to changes in the level of antibiotic resistance in S. pyogenes. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ku, Min-Je [Functional Proteomics Center, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Lee, Won-Ho [Functional Proteomics Center, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Biotechnology and Genetic Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Nam, Ki-hyun; Rhee, Kyeong-hee [Biomedical Research Center, Life Science Division, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Lee, Ki-Seog [Biotechnology and Genetic Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Kim, Eunice EunKyung [Biomedical Research Center, Life Science Division, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Yu, Myung-Hee [Functional Proteomics Center, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Hwang, Kwang Yeon, E-mail: hwangky@kist.re.kr [Biomedical Research Center, Life Science Division, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Functional Proteomics Center, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2005-04-01

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

  5. Streptococcus pyogenes Phospholipase A2 Induces the Expression of Adhesion Molecules on Human Umbilical Vein Endothelial Cells and Aorta of Mice.

    Science.gov (United States)

    Oda, Masataka; Domon, Hisanori; Kurosawa, Mie; Isono, Toshihito; Maekawa, Tomoki; Yamaguchi, Masaya; Kawabata, Shigetada; Terao, Yutaka

    2017-01-01

    The Streptococcus pyogenes phospholipase A 2 (SlaA) gene is highly conserved in the M3 serotype of group A S. pyogenes , which often involves hypervirulent clones. However, the role of SlaA in S. pyogenes pathogenesis is unclear. Herein, we report that SlaA induces the expression of intercellular adhesion molecule 1 (ICAM1) and vascular cell adhesion molecule 1 (VCAM1) via the arachidonic acid signaling cascade. Notably, recombinant SlaA induced ICAM1 and VCAM1 expression in human umbilical vein endothelial cells (HUVECs), resulting in enhanced adhesion of human monocytic leukemia (THP-1) cells. However, C134A, a variant enzyme with no enzymatic activity, did not induce such events. In addition, culture supernatants from S. pyogenes SSI-1 enhanced the adhesion of THP-1 cells to HUVECs, but culture supernatants from the Δ slaA isogenic mutant strain had limited effects. Aspirin, a cyclooxygenase 2 inhibitor, prevented the adhesion of THP-1 cells to HUVECs and did not induce ICAM1 and VCAM1 expression in HUVECs treated with SlaA. However, zileuton, a 5-lipoxygenase inhibitor, did not exhibit such effects. Furthermore, pre-administration of aspirin in mice intravenously injected with SlaA attenuated the transcriptional abundance of ICAM1 and VCAM1 in the aorta. These results suggested that SlaA from S. pyogenes stimulates the expression of adhesion molecules in vascular endothelial cells. Thus, SlaA contributes to the inflammation of vascular endothelial cells upon S. pyogenes infection.

  6. The molecular mechanism of N-acetylglucosamine side-chain attachment to the Lancefield group A carbohydrate in Streptococcus pyogenes.

    Science.gov (United States)

    Rush, Jeffrey S; Edgar, Rebecca J; Deng, Pan; Chen, Jing; Zhu, Haining; van Sorge, Nina M; Morris, Andrew J; Korotkov, Konstantin V; Korotkova, Natalia

    2017-11-24

    In many Lactobacillales species ( i.e. lactic acid bacteria), peptidoglycan is decorated by polyrhamnose polysaccharides that are critical for cell envelope integrity and cell shape and also represent key antigenic determinants. Despite the biological importance of these polysaccharides, their biosynthetic pathways have received limited attention. The important human pathogen, Streptococcus pyogenes , synthesizes a key antigenic surface polymer, the Lancefield group A carbohydrate (GAC). GAC is covalently attached to peptidoglycan and consists of a polyrhamnose polymer, with N -acetylglucosamine (GlcNAc) side chains, which is an essential virulence determinant. The molecular details of the mechanism of polyrhamnose modification with GlcNAc are currently unknown. In this report, using molecular genetics, analytical chemistry, and mass spectrometry analysis, we demonstrated that GAC biosynthesis requires two distinct undecaprenol-linked GlcNAc-lipid intermediates: GlcNAc-pyrophosphoryl-undecaprenol (GlcNAc-P-P-Und) produced by the GlcNAc-phosphate transferase GacO and GlcNAc-phosphate-undecaprenol (GlcNAc-P-Und) produced by the glycosyltransferase GacI. Further investigations revealed that the GAC polyrhamnose backbone is assembled on GlcNAc-P-P-Und. Our results also suggested that a GT-C glycosyltransferase, GacL, transfers GlcNAc from GlcNAc-P-Und to polyrhamnose. Moreover, GacJ, a small membrane-associated protein, formed a complex with GacI and significantly stimulated its catalytic activity. Of note, we observed that GacI homologs perform a similar function in Streptococcus agalactiae and Enterococcus faecalis In conclusion, the elucidation of GAC biosynthesis in S. pyogenes reported here enhances our understanding of how other Gram-positive bacteria produce essential components of their cell wall. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Oral immunization of mice with engineered Lactobacillus gasseri NM713 strain expressing Streptococcus pyogenes M6 antigen.

    Science.gov (United States)

    Mansour, Nahla M; Abdelaziz, Sahar A

    2016-08-01

    The aim of this in vivo study was to evaluate the effects of a recombinant probiotic strain, Lactobacillus gasseri NM713, which expresses the conserved region of streptococcal M6 protein (CRR6), as an oral vaccine against Streptococcus pyogenes. A dose of 10(9) cells of the recombinant strain in 150 μL PBS buffer was administered orally to a group of mice. One control group received an equivalent dose of Lb. gasseri NM613 (containing the empty plasmid without insert) or and another control group received PBS buffer. Each group contained 30 mice. The immunization protocol was followed on three consecutive days, after which two booster doses were administered at two week intervals. Fecal and serum samples were collected from the mice on Days 18, 32, 46, 58 after the first immunization and Day 0 prior to immunization. Anti-CRR6 IgA and IgG concentrations were measured by ELISA in fecal and sera samples, respectively, to assess immune responses. Vaccination with the recombinant Lb. gasseri NM713 strain induced significant protection after nasal challenge with S. pyogenes, only a small percentage of this group developing streptococcal infection (10%) or dying of it (3.3%) compared with the NM613 and PBS control groups, high percentages of which developed streptococcal infection (43.3% and 46.7%, respectively) and died of it (46.7% and 53%, respectively). These results indicate that recombinant Lb. gasseri NM713 has potential as an oral delivery vaccine against streptococcus group A. © 2016 The Societies and John Wiley & Sons Australia, Ltd.

  8. Case report of the family transmission of Streptococcus pyogenes orbital cellulitis

    Directory of Open Access Journals (Sweden)

    Christelle Doyon, MD

    2017-06-01

    Conclusions and importance: To our knowledge, this is the first case ever reported of family transmission of orbital cellulitis. This highlights the importance of early diagnosis and treatment of S pyogenes, and the role of throat cultures as means of diagnosis even in the absence of symptoms or signs of pharyngitis.

  9. Characteristics of Streptococcus Strains Isolated From Clinical Specimens Other Than Throat Culture and Characteristics of Streptococcal Infections

    Directory of Open Access Journals (Sweden)

    Fatma Ünlü

    2017-12-01

    Full Text Available Aim: This study was to investigate the laboratory and clinical features of patients in whom Streptococcus spp. were isolated from cultures other than throat cultures. Methods: A total of 161 Streptococcus strains isolated from clinical specimens from 101 (64% hospitalized patients and 65 (36% outpatients and clinical and laboratory features of patients were investigated retrospectively. Isolated Streptococcus strains were further identified for type and antibiotic susceptibility according to the Clinical and Laboratory Standards Institute guidelines. Results: Streptococcus strains types were determined as follows; group A (9-5.6%, group B (64-39.7%, group C (2-1.2%, group D (2-1.2%, group G (2-1.2%, viridans (57-32.2%, and Streptococcus pneumonia (24-14,9%. Most frequently observed infections were urinary system infections (52-32.2%, skin and soft tissue infections (48-29.8% and pulmonary infections (25-15.5%. In 87 (54% of patients, there was more than one comorbid condition. While all group A Streptococcus pyogenes strains were susceptible to penicillin, 13% of Streptococcus pneumonia were resistant to penicillin and 36.3% were resistant to macrolides. Mortality was observed in eight patients. Conclusion: Invasive streptococcal infections may cause serious mortality and morbidity especially in patients with comorbid conditions. Early detection and appropriate antimicrobial therapy are most important parameters for the management of streptococcal infections.

  10. Citrulline protects Streptococcus pyogenes from acid stress using the arginine deiminase pathway and the F1Fo-ATPase.

    Science.gov (United States)

    Cusumano, Zachary T; Caparon, Michael G

    2015-04-01

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

  11. Factor H binds to the hypervariable region of many Streptococcus pyogenes M proteins but does not promote phagocytosis resistance or acute virulence

    DEFF Research Database (Denmark)

    Gustafsson, Caj Ulrik Mattias; Lannergård, Jonas; Nilsson, Olof Rickard

    2013-01-01

    Many pathogens express a surface protein that binds the human complement regulator factor H (FH), as first described for Streptococcus pyogenes and the antiphagocytic M6 protein. It is commonly assumed that FH recruited to an M protein enhances virulence by protecting the bacteria against...... complement deposition and phagocytosis, but the role of FH-binding in S. pyogenes pathogenesis has remained unclear and controversial. Here, we studied seven purified M proteins for ability to bind FH and found that FH binds to the M5, M6 and M18 proteins but not the M1, M3, M4 and M22 proteins. Extensive...... 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...

  12. Adaptive Immunity against Streptococcus pyogenes in Adults Involves Increased IFN-gamma and IgG3 Responses Compared with Children

    DEFF Research Database (Denmark)

    Mortensen, Rasmus; Nissen, Thomas Norrelykke; Blauenfeldt, Thomas

    2015-01-01

    Each year, millions of people are infected with Streptococcus pyogenes, leading to an estimated 500,000 annual deaths worldwide. For unknown reasons, school-aged children have substantially higher infection rates than adults. The goal for this study was to provide, to our knowledge, the first...... detailed characterization of the human adaptive immune response against S. pyogenes in both children and adults. We report that all adults in our study, as well as most children, showed immunity against the two conserved group A streptococci (GAS) Ags, streptococcal C5a peptidase and immunogenic secreted...... significantly with IFN-γ, but not with IL-5, IL-13, IL-17, or TNF-α. Interestingly, children showed a similar pattern of Ag-specific cytokine release, but displayed significantly lower levels of IgG3 and IFN-γ compared with adults. Thus, human immune responses against S. pyogenes consist of a robust Th1...

  13. Caracterización molecular de Streptococcus pyogenes causantes de enfermedad invasora y síndrome de shock tóxico estreptocócico Molecular characterization of Streptococcus pyogenes from invasive disease and streptococcal toxic shock syndrome episodes

    Directory of Open Access Journals (Sweden)

    F. Traverso

    2010-02-01

    Full Text Available Streptococcus pyogenes es el agente causal de varias enfermedades comunes entre las que se incluyen la faringoamigdalitis, la escarlatina y el impétigo. Sin embargo, en las últimas décadas se ha registrado mundialmente un resurgimiento de casos de enfermedad invasora y síndrome de shock tóxico estreptocócico (SSTE. El propósito del presente trabajo fue estudiar la diversidad genética, los factores de virulencia (genes spe, sme, ssa y la sensibilidad a los antibióticos de 10 cepas de S. pyogenes causantes de enfermedad invasora y SSTE. Los aislamientos fueron recuperados de hemocultivos de pacientes internados en el Hospital Santamarina y en la Nueva Clínica Chacabuco (Tandil, Argentina entre diciembre de 2000 y abril de 2005. Predominaron 2 patrones de electroforesis en campo pulsante. El más frecuente comprendió 5 aislamientos del tipo emm1-T1, con perfil de toxinas speA, speB, speF, speG y smeZ. El segundo patrón más frecuente incluyó 2 aislamientos tipo emm3-TNT (speB, speF, speG. Estos dos tipos (emm1 y emm3 fueron los prevalentes en las infecciones invasoras. Las otras tres cepas correspondieron a los tipos emm49-TNT (speB, speC, speF, speG, emm75-T25 (speB, speF, speG y emm83-TNT (speB, speF, speG, ssa, smeZ. Se encontró diversidad genética entre las cepas aisladas, pero todos los aislamientos fueron sensibles a penicilina, cefotaxima, eritromicina, clindamicina, cloranfenicol, tetraciclina y rifampicina. Por tal motivo, aún es válido el tratamiento empírico con penicilina asociada a clindamicina.Streptococcus pyogenes causes a variety of common human diseases, including pharyngitis, scarlet fever and impetigo. Nevertheless, the past decades have witnessed a worldwide resurgence in invasive disease and streptococcal toxic shock syndrome (STSS. The objective of the present study is to evaluate the genetic diversity, virulence gene distribution (spe, sme and ssa genes and susceptibility pattern of 10 S. pyogenes isolates

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2015-10-01

    Streptococcus pyogenes genome. Mutations that inactivate CovR or CovS enhance the virulence of this bacterium. We determined complete transcriptomes of a naturally CovS-inactivated invasive deep tissue isolate of an emm23 strain of S. pyogenes (M23ND) and its complemented avirulent variant (CovS(+)). We identified diverse virulence genes whose altered expression revealed a genetic switching of a nonvirulent form of M23ND to a highly virulent strain. Furthermore, we also systematically uncovered for the first time the comparative levels of expression of a broad spectrum of metabolic genes, which reflected different metabolic needs of the bacterium as it invaded deeper tissue of the human host. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

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

    Science.gov (United States)

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

    2016-07-01

    Variable-number tandem-repeat (VNTR) polymorphisms are ubiquitous in bacteria. However, only a small fraction of them has been functionally studied. Here, we report an intergenic VNTR polymorphism that confers an altered level of toxin production and increased virulence in Streptococcus pyogenes The nature of the polymorphism is a one-unit deletion in a three-tandem-repeat locus upstream of the rocA gene encoding a sensor kinase. S. pyogenes strains with this type of polymorphism cause human infection and produce significantly larger amounts of the secreted cytotoxins S. pyogenes NADase (SPN) and streptolysin O (SLO). Using isogenic mutant strains, we demonstrate that deleting one or more units of the tandem repeats abolished RocA production, reduced CovR phosphorylation, derepressed multiple CovR-regulated virulence factors (such as SPN and SLO), and increased virulence in a mouse model of necrotizing fasciitis. The phenotypic effect of the VNTR polymorphism was nearly the same as that of inactivating the rocA gene. In summary, we identified and characterized an intergenic VNTR polymorphism in S. pyogenes that affects toxin production and virulence. These new findings enhance understanding of rocA biology and the function of VNTR polymorphisms in S. pyogenes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

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

    Science.gov (United States)

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

    2013-10-01

    Streptococcus pyogenes is a common colonizer of the mucosal layers in the mouth, nose, and pharynx but it is also a major Gram-positive human pathogen that causes infections ranging from pharyngitis to severe systemic diseases. The lactobacilli colonize the oral tracts and are known to protect against colonization by many pathogens. Epithelial cells participate in the innate host defense by expressing a variety of proinflammatory cytokines and TLRs in the interaction with microorganisms. The potentially probiotic strain Lactobacillus plantarum was investigated for its capacity to influence the innate immune response of HEp-2 and A549 epithelial cells to S. pyogenes infection. In both epithelial cell types, pre-treatment with L. plantarum showed inhibition of S. pyogenes growth and a greater decrease in IL-17 and IL-23 levels compared to the control. Pre-treatment with the anti-TLR2/4 antibody abolished the inhibitory effects of L. plantarum on IL-17 and IL-23 production following S. pyogenes infection, indicating that L. plantarum downregulates TLR2/4-dependent IL-17 and IL-23 production. Overall, our findings suggest that in epithelial cell cultures with S. pyogenes, cytokine responses are modulated by the presence of L. plantarum through the induction of TLR2/TLR4. © 2013.

  18. Local activation of coagulation factor XIII reduces systemic complications and improves the survival of mice after Streptococcus pyogenes M1 skin infection.

    Science.gov (United States)

    Deicke, Christin; Chakrakodi, Bhavya; Pils, Marina C; Dickneite, Gerhard; Johansson, Linda; Medina, Eva; Loof, Torsten G

    2016-11-01

    Coagulation is a mechanism for wound healing after injury. Several recent studies delineate an additional role of the intrinsic pathway of coagulation, also known as the contact system, in the early innate immune response against bacterial infections. In this study, we investigated the role of factor XIII (FXIII), which is activated upon coagulation induction, during Streptococcus pyogenes-mediated skin and soft tissue infections. FXIII has previously been shown to be responsible for the immobilization of bacteria within a fibrin network which may prevent systemic bacterial dissemination. In order to investigate if the FXIII-mediated entrapment of S. pyogenes also influences the disease outcome we used a murine S. pyogenes M1 skin and soft tissue infection model. Here, we demonstrate that a lack of FXIII leads to prolonged clotting times, increased signs of inflammation, and elevated bacterial dissemination. Moreover, FXIII-deficient mice show an impaired survival when compared with wildtype animals. Additionally, local reconstitution of FXIII-deficient mice with a human FXIII-concentrate (Fibrogammin ® P) could reduce the systemic complications, suggesting a protective role for FXIII during early S. pyogenes skin infection. FXIII therefore might be a possible therapeutically application to support the early innate immune response during skin infections caused by S. pyogenes. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

    Science.gov (United States)

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

    2014-08-08

    Streptococcus pyogenes, a human-restricted pathogen, accounts for substantial mortality related to infections worldwide. Recent studies indicate that streptococci produce and respond to several secreted peptide signaling molecules (pheromones), including those known as short hydrophobic peptides (SHPs), to regulate gene expression by a quorum-sensing mechanism. Upon transport into the bacterial cell, pheromones bind to and modulate activity of receptor proteins belonging to the Rgg family of transcription factors. Previously, we reported biofilm regulation by the Rgg2/3 quorum-sensing circuit in S. pyogenes. The aim of this study was to identify the composition of mature pheromones from cell-free culture supernatants that facilitate biofilm formation. Bioluminescent reporters were employed to detect active pheromones in culture supernatants fractionated by reverse-phase chromatography, and mass spectrometry was used to characterize their properties. Surprisingly, multiple SHPs that varied by length were detected. Synthetic peptides of each variant were tested individually using bioluminescence reporters and biofilm growth assays, and although activities differed widely among the group, peptides comprising the C-terminal eight amino acids of the full-length native peptide were most active. Direct Rgg/SHP interactions were determined using a fluorescence polarization assay that utilized FITC-labeled peptide ligands. Peptide receptor affinities were seen to be as low as 500 nm and their binding affinities directly correlated with observed bioactivity. Revelation of naturally produced pheromones along with determination of their affinity for cognate receptors are important steps forward in designing compounds whose purpose is positioned for future therapeutics aimed at treating infections through the interference of bacterial communication. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. The isolation rate of Staphylococcus and Streptococcus pathogenic ...

    African Journals Online (AJOL)

    Staphylococcus and Streptococcus isolates are among the major pathogens causing different diseases in Ethiopia. The aim of this study was to determine the frequency of isolation and sensitivity pattern of Staphylococcus and Streptococcus against the commonly used antibiotics. A retrospective study was carried out in this ...

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

    Science.gov (United States)

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

    2014-01-01

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

  2. Streptococcus pyogenes Endopeptidase O Contributes to Evasion from Complement-mediated Bacteriolysis via Binding to Human Complement Factor C1q.

    Science.gov (United States)

    Honda-Ogawa, Mariko; Sumitomo, Tomoko; Mori, Yasushi; Hamd, Dalia Talat; Ogawa, Taiji; Yamaguchi, Masaya; Nakata, Masanobu; Kawabata, Shigetada

    2017-03-10

    Streptococcus pyogenes secretes various virulence factors for evasion from complement-mediated bacteriolysis. However, full understanding of the molecules possessed by this organism that interact with complement C1q, an initiator of the classical complement pathway, remains elusive. In this study, we identified an endopeptidase of S. pyogenes , PepO, as an interacting molecule, and investigated its effects on complement immunity and pathogenesis. Enzyme-linked immunosorbent assay and surface plasmon resonance analysis findings revealed that S. pyogenes recombinant PepO bound to human C1q in a concentration-dependent manner under physiological conditions. Sites of inflammation are known to have decreased pH levels, thus the effects of PepO on bacterial evasion from complement immunity was analyzed in a low pH condition. Notably, under low pH conditions, PepO exhibited a higher affinity for C1q as compared with IgG, and PepO inhibited the binding of IgG to C1q. In addition, pepO deletion rendered S. pyogenes more susceptible to the bacteriocidal activity of human serum. Also, observations of the morphological features of the pepO mutant strain (Δ pepO ) showed damaged irregular surfaces as compared with the wild-type strain (WT). WT-infected tissues exhibited greater severity and lower complement activity as compared with those infected by Δ pepO in a mouse skin infection model. Furthermore, WT infection resulted in a larger accumulation of C1q than that with Δ pepO. Our results suggest that interaction of S. pyogenes PepO with C1q interferes with the complement pathway, which enables S. pyogenes to evade complement-mediated bacteriolysis under acidic conditions, such as seen in inflammatory sites. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Streptococcus pyogenes Endopeptidase O Contributes to Evasion from Complement-mediated Bacteriolysis via Binding to Human Complement Factor C1q*

    Science.gov (United States)

    Honda-Ogawa, Mariko; Sumitomo, Tomoko; Mori, Yasushi; Hamd, Dalia Talat; Ogawa, Taiji; Yamaguchi, Masaya; Nakata, Masanobu; Kawabata, Shigetada

    2017-01-01

    Streptococcus pyogenes secretes various virulence factors for evasion from complement-mediated bacteriolysis. However, full understanding of the molecules possessed by this organism that interact with complement C1q, an initiator of the classical complement pathway, remains elusive. In this study, we identified an endopeptidase of S. pyogenes, PepO, as an interacting molecule, and investigated its effects on complement immunity and pathogenesis. Enzyme-linked immunosorbent assay and surface plasmon resonance analysis findings revealed that S. pyogenes recombinant PepO bound to human C1q in a concentration-dependent manner under physiological conditions. Sites of inflammation are known to have decreased pH levels, thus the effects of PepO on bacterial evasion from complement immunity was analyzed in a low pH condition. Notably, under low pH conditions, PepO exhibited a higher affinity for C1q as compared with IgG, and PepO inhibited the binding of IgG to C1q. In addition, pepO deletion rendered S. pyogenes more susceptible to the bacteriocidal activity of human serum. Also, observations of the morphological features of the pepO mutant strain (ΔpepO) showed damaged irregular surfaces as compared with the wild-type strain (WT). WT-infected tissues exhibited greater severity and lower complement activity as compared with those infected by ΔpepO in a mouse skin infection model. Furthermore, WT infection resulted in a larger accumulation of C1q than that with ΔpepO. Our results suggest that interaction of S. pyogenes PepO with C1q interferes with the complement pathway, which enables S. pyogenes to evade complement-mediated bacteriolysis under acidic conditions, such as seen in inflammatory sites. PMID:28154192

  4. Streptococcus pyogenes Sortase Mutants Are Highly Susceptible to Killing by Host Factors Due to Aberrant Envelope Physiology

    Science.gov (United States)

    Raz, Assaf; Tanasescu, Ana-Maria; Zhao, Anna M.; Serrano, Anna; Alston, Tricia; Sol, Asaf; Bachrach, Gilad; Fischetti, Vincent A.

    2015-01-01

    Cell wall anchored virulence factors are critical for infection and colonization of the host by Gram-positive bacteria. Such proteins have an N-terminal leader sequence and a C-terminal sorting signal, composed of an LPXTG motif, a hydrophobic stretch, and a few positively charged amino acids. The sorting signal halts translocation across the membrane, allowing sortase to cleave the LPXTG motif, leading to surface anchoring. Deletion of sortase prevents the anchoring of virulence factors to the wall; the effects on bacterial physiology however, have not been thoroughly characterized. Here we show that deletion of Streptococcus pyogenes sortase A leads to accumulation of sorting intermediates, particularly at the septum, altering cellular morphology and physiology, and compromising membrane integrity. Such cells are highly sensitive to cathelicidin, and are rapidly killed in blood and plasma. These phenomena are not a loss-of-function effect caused by the absence of anchored surface proteins, but specifically result from the accumulation of sorting intermediates. Reduction in the level of sorting intermediates leads to a return of the sortase mutant to normal morphology, while expression of M protein with an altered LPXTG motif in wild type cells leads to toxicity in the host environment, similar to that observed in the sortase mutant. These unanticipated effects suggest that inhibition of sortase by small-molecule inhibitors could similarly lead to the rapid elimination of pathogens from an infected host, making such inhibitors much better anti-bacterial agents than previously believed. PMID:26484774

  5. The AgI/II family adhesin AspA is required for respiratory infection by Streptococcus pyogenes.

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    Linda Franklin

    Full Text Available Streptococcus pyogenes (GAS is a human pathogen that causes pharyngitis and invasive diseases such as toxic shock syndrome and sepsis. The upper respiratory tract is the primary reservoir from which GAS can infect new hosts and cause disease. The factors involved in colonisation are incompletely known however. Previous evidence in oral streptococci has shown that the AgI/II family proteins are involved. We hypothesized that the AspA member of this family might be involved in GAS colonization. We describe a novel mouse model of GAS colonization of the nasopharynx and lower respiratory tract to elucidate these interactions. We used two clinical M serotypes expressing AspA, and their aspA gene deletant isogenic mutants in experiments using adherence assays to respiratory epithelium, macrophage phagocytosis and neutrophil killing assays and in vivo models of respiratory tract colonisation and infection. We demonstrated the requirement for AspA in colonization of the respiratory tract. AspA mutants were cleared from the respiratory tract and were deficient in adherence to epithelial cells, and susceptible to phagocytosis. Expression of AspA in the surrogate host Lactococcus lactis protected bacteria from phagocytosis. Our results suggest that AspA has an essential role in respiratory infection, and may function as a novel anti-phagocytic factor.

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

    Science.gov (United States)

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

    2013-01-01

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

  7. Structure and interactions of a dimeric variant of sHIP, a novel virulence determinant of Streptococcus pyogenes

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    Carl eDiehl

    2016-02-01

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

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

    Science.gov (United States)

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

    2014-08-01

    Streptococcus tigurinus is a new member of the Streptococcus viridians group and is closely related to Streptococcus mitis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae, Streptococcus oralis, and Streptococcus infantis. The type strain AZ_3a(T) of S. tigurinus was originally isolated from a patient with infective endocarditis. Accurate identification of S. tigurinus is facilitated only by newer molecular methods like 16S rRNA gene analysis. During the course of study on bacteraemia and infective endocarditis with reference to periodontitis and viridians group of streptococci, a strain of S. tigurinus isolated from subgingival plaque of a patient with periodontitis identified by 16S rRNA gene analysis, which was originally identified as Streptococcus pluranimalium by Vitek 2. Confirmation by 16S rRNA gene analysis showed 99.39% similarity (1476/1485 bp) with S. tigurinus AZ_3a(T) (AORU01000002). To the best of our knowledge, this is the first report of isolation of S. tigurinus from the oral cavity of a periodontitis patient. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  9. Expression profile of BAFF in peripheral blood from patients of IgA nephropathy: Correlation with clinical features and Streptococcus pyogenes infection.

    Science.gov (United States)

    Zheng, Nuoyan; Fan, Jinjin; Wang, Bing; Wang, Dongxian; Feng, Pinning; Yang, Qiongqiong; Yu, Xueqing

    2017-04-01

    B cells are critically important for the pathogenesis of IgA nephropathy (IgAN). The present study aimed to investigate the abundance of B cell activating factor (BAFF), which belongs to the tumor necrosis factor superfamily, in the peripheral blood of patients with IgAN. The different forms of BAFF in peripheral blood and its association with clinical features and immunological factors were analyzed. mRNA levels of BAFF and other associated genes in the peripheral blood mononuclear cells (PBMCs) of patients with IgAN and controls were analyzed by quantitative polymerase chain reaction. Cellular BAFF proteins in PBMCs and plasma soluble BAFF proteins were measured by western blot analysis and ELISA, respectively. PBMCs from patients were stimulated with Streptococcus pyogenes (S. pyogenes) ex vivo for the BAFF secretion assay. The data demonstrated that, although mRNA levels of BAFF in PBMC were not significantly increased in patients with IgAN, they were positively associated with those of a proliferation inducing ligand (APRIL), Toll‑like receptor (TLR)2, TLR4 and TLR7. The cellular BAFF protein in PBMCs was not upregulated. Plasma BAFF protein levels in patients with IgAN (n=76) were significantly decreased compared with controls. However, plasma BAFF levels were positively associated with serum creatinine, proteinuria, uric acid and group A Streptococcus infection index in patients with IgAN. In patients with IgAN, plasma BAFF concentrations were markedly higher in those with more severe renal tubular atrophy/interstitial fibrosis and global glomerulosclerosis. Furthermore, BAFF production in PBMCs of patients with IgAN was increased following S. pyogenes stimulation ex vivo. In conclusion, plasma BAFF levels in patients with IgAN were associated with renal function and disease activity. S. pyogenes infection was closely associated with BAFF production in patients with IgAN.

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

    Science.gov (United States)

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

    2015-02-01

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

  11. Heterologous expression of Ralp3 in Streptococcus pyogenes M2 and M6 strains affects the virulence characteristics.

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    Nikolai Siemens

    Full Text Available BACKGROUND: Ralp3 is a transcriptional regulator present in a serotype specific fashion on the chromosome of the human pathogen Streptococcus pyogenes (group A streptococci, GAS. In serotypes harbouring the ralp3 gene either positive or negative effects on important metabolic and virulence genes involved in colonization and immune evasion in the human host were observed. A previous study revealed that deletion of ralp3 in a GAS M49 serotype significantly attenuated many virulence traits and caused metabolic disadvantages. This leads to two questions: (i which kind of consequences could Ralp3 expression have in GAS serotypes naturally lacking this gene, and (ii is Ralp3 actively lost during evolution in these serotypes. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the role of Ralp3 in GAS M2 and M6 pathogenesis. Both serotypes lack ralp3 on their chromosome. The heterologous expression of ralp3 in both serotypes resulted in reduced attachment to and internalization into the majority of tested epithelial cells. Both ralp3 expression strains showed a decreased ability to survive in human blood and exclusively M2::ralp3 showed decreased survival in human serum. Both mutants secreted more active SpeB in the supernatant, resulting in a higher activity compared to wild type strains. The respective M2 and M6 wild type strains outcompeted the ralp3 expression strains in direct metabolic competition assays. The phenotypic changes observed in the M2:ralp3 and M6:ralp3 were verified on the transcriptional level. Consistent with the virulence data, tested genes showed transcript level changes in the same direction. CONCLUSIONS/SIGNIFICANCE: Together these data suggest that Ralp3 can take over transcriptional control of virulence genes in serotypes lacking the ralp3 gene. Those serotypes most likely lost Ralp3 during evolution since obviously expression of this gene is disadvantageous for metabolism and pathogenesis.

  12. The Influence of Programmed Cell Death in Myeloid Cells on Host Resilience to Infection with Legionella pneumophila or Streptococcus pyogenes.

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    Pia Gamradt

    2016-12-01

    Full Text Available Pathogen clearance and host resilience/tolerance to infection are both important factors in surviving an infection. Cells of the myeloid lineage play important roles in both of these processes. Neutrophils, monocytes, macrophages, and dendritic cells all have important roles in initiation of the immune response and clearance of bacterial pathogens. If these cells are not properly regulated they can result in excessive inflammation and immunopathology leading to decreased host resilience. Programmed cell death (PCD is one possible mechanism that myeloid cells may use to prevent excessive inflammation. Myeloid cell subsets play roles in tissue repair, immune response resolution, and maintenance of homeostasis, so excessive PCD may also influence host resilience in this way. In addition, myeloid cell death is one mechanism used to control pathogen replication and dissemination. Many of these functions for PCD have been well defined in vitro, but the role in vivo is less well understood. We created a mouse that constitutively expresses the pro-survival B-cell lymphoma (bcl-2 protein in myeloid cells (CD68(bcl2tg, thus decreasing PCD specifically in myeloid cells. Using this mouse model we explored the impact that decreased cell death of these cells has on infection with two different bacterial pathogens, Legionella pneumophila and Streptococcus pyogenes. Both of these pathogens target multiple cell death pathways in myeloid cells, and the expression of bcl2 resulted in decreased PCD after infection. We examined both pathogen clearance and host resilience and found that myeloid cell death was crucial for host resilience. Surprisingly, the decreased myeloid PCD had minimal impact on pathogen clearance. These data indicate that the most important role of PCD during infection with these bacteria is to minimize inflammation and increase host resilience, not to aid in the clearance or prevent the spread of the pathogen.

  13. Sensibilidad antimicrobiana y caracterización de cepas de Streptococcus pyogenes aisladas de un brote de escarlatina

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    Pedraza-Avilés Alberto González

    2002-01-01

    Full Text Available Objetivo. Evaluar la actividad in vitro de 13 antibióticos contra 47 Streptococcus pyogenes grupo A (SGA. Determinar la presencia de genes que codifican para exotoxina pirogénica estreptocóccica A (SpeA y serotipos con base en proteína M. Material y métodos. Estudio transversal hecho en el Centro de Salud Dr. José Castro Villagrana sobre un brote de escarlatina en el Colegio Espíritu de América, entre diciembre de 1999 y enero de 2000. El número de niños estudiados fue 137. Se extrajeron porcentajes de sensibilidad. La concentración inhibitoria mínima (CIM se obtuvo por microdilución semiautomatizada. Se utilizó un secuenciador automatizado de DNA para el análisis de variación de secuencias en los genes que codifican para proteína M y SpeA. Resultados. Todas las cepas fueron sensibles a beta-lactámicos y clindamicina; 12.7% fueron resistentes a eritromicina. El serotipo M2 fue el más frecuente, 27 del total. Prácticamente todas las bacterias (96% con el gen SpeA tienen el gen que codifica para el serotipo M2. Conclusiones. Debido a la reciente reaparición de infecciones por SGA se sugiere realizar estudios tanto de sensibilidad a macrólidos y beta-lactámicos, como de epidemiología molecular.

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

    Science.gov (United States)

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

    2015-11-17

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

  15. The Influence of Programmed Cell Death in Myeloid Cells on Host Resilience to Infection with Legionella pneumophila or Streptococcus pyogenes

    Science.gov (United States)

    Gamradt, Pia; Xu, Yun; Gratz, Nina; Duncan, Kellyanne; Kobzik, Lester; Högler, Sandra; Decker, Thomas

    2016-01-01

    Pathogen clearance and host resilience/tolerance to infection are both important factors in surviving an infection. Cells of the myeloid lineage play important roles in both of these processes. Neutrophils, monocytes, macrophages, and dendritic cells all have important roles in initiation of the immune response and clearance of bacterial pathogens. If these cells are not properly regulated they can result in excessive inflammation and immunopathology leading to decreased host resilience. Programmed cell death (PCD) is one possible mechanism that myeloid cells may use to prevent excessive inflammation. Myeloid cell subsets play roles in tissue repair, immune response resolution, and maintenance of homeostasis, so excessive PCD may also influence host resilience in this way. In addition, myeloid cell death is one mechanism used to control pathogen replication and dissemination. Many of these functions for PCD have been well defined in vitro, but the role in vivo is less well understood. We created a mouse that constitutively expresses the pro-survival B-cell lymphoma (bcl)-2 protein in myeloid cells (CD68(bcl2tg), thus decreasing PCD specifically in myeloid cells. Using this mouse model we explored the impact that decreased cell death of these cells has on infection with two different bacterial pathogens, Legionella pneumophila and Streptococcus pyogenes. Both of these pathogens target multiple cell death pathways in myeloid cells, and the expression of bcl2 resulted in decreased PCD after infection. We examined both pathogen clearance and host resilience and found that myeloid cell death was crucial for host resilience. Surprisingly, the decreased myeloid PCD had minimal impact on pathogen clearance. These data indicate that the most important role of PCD during infection with these bacteria is to minimize inflammation and increase host resilience, not to aid in the clearance or prevent the spread of the pathogen. PMID:27973535

  16. Extended binding site on fibronectin for the functional upstream domain of protein F1 of Streptococcus pyogenes.

    Science.gov (United States)

    Maurer, Lisa M; Tomasini-Johansson, Bianca R; Ma, Wenjiang; Annis, Douglas S; Eickstaedt, Nathan L; Ensenberger, Martin G; Satyshur, Kenneth A; Mosher, Deane F

    2010-12-24

    The 49-residue functional upstream domain (FUD) of Streptococcus pyogenes F1 adhesin interacts with fibronectin (FN) in a heretofore unknown manner that prevents assembly of a FN matrix. Biotinylated FUD (b-FUD) bound to adsorbed FN or its recombinant N-terminal 70-kDa fibrin- and gelatin-binding fragment (70K). Binding was blocked by FN or 70K, but not by fibrin- or gelatin-binding subfragments of 70K. Isothermal titration calorimetry showed that FUD binds with K(d) values of 5.2 and 59 nM to soluble 70K and FN, respectively. We tested sets of FUD mutants and epitope-mapped monoclonal antibodies (mAbs) for ability to compete with b-FUD for binding to FN or to block FN assembly by cultured fibroblasts. Deletions or alanine substitutions throughout FUD caused loss of both activities. mAb 4D1 to the (2)FNI module had little effect, whereas mAb 7D5 to the (4)FNI module in the fibrin-binding region, 5C3 to the (9)FNI module in the gelatin-binding region, or L8 to the G-strand of (1)FNIII module adjacent to (9)FNI caused loss of binding of b-FUD to FN and decreased FN assembly. Conversely, FUD blocked binding of 7D5, 5C3, or L8, but not of 4D1, to FN. Circular dichroism indicated that FUD binds to 70K by β-strand addition, a possibility supported by modeling based on crystal structures of peptides bound to (2)FNI-(5)FNI of the fibrin-binding domain and (8)FNI-(9)FNI of the gelatin-binding domain. Thus, the interaction likely involves an extensive anti-parallel β-zipper in which FUD interacts with the E-strands of (2)FNI-(5)FNI and (8)FNI-(9)FNI.

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

    Science.gov (United States)

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

    2014-09-01

    Four Gram-stain-positive, catalase-negative, coccoid-shaped organisms were isolated from elephant oral cavities. The isolates were tentatively identified as streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequencing studies confirmed the organisms to be members of the genus Streptococcus. Two isolates (NUM 6304(T) and NUM 6312) were related most closely to Streptococcus salivarius with 96.8 % and 93.1 % similarity based on the 16S rRNA gene and the RNA polymerase β subunit encoding gene (rpoB), respectively, and to Streptococcus vestibularis with 83.7 % similarity based on the 60 kDa heat-shock protein gene (groEL). The other two isolates (NUM 6306(T) and NUM 6318) were related most closely to S. vestibularis with 97.0 % and 82.9 % similarity based on the 16S rRNA and groEL genes, respectively, and to S. salivarius with 93.5 % similarity based on the rpoB gene. Based on phylogenetic and phenotypic evidence, these isolates are suggested to represent novel species of the genus Streptococcus, for which the names Streptococcus loxodontisalivarius sp. nov. (type strain NUM 6304(T) = JCM 19287(T) = DSM 27382(T)) and Streptococcus saliviloxodontae sp. nov. (type strain NUM 6306(T) = JCM 19288(T) = DSM 27513(T)) are proposed. © 2014 IUMS.

  18. Changing epidemiology of Streptococcus pyogenes emm types and associated invasive and noninvasive infections in Southern Taiwan.

    Science.gov (United States)

    Su, Yu-Fang; Wang, Shih-Min; Lin, Ya-Lan; Chuang, Woei-Jer; Lin, Yee-Shin; Wu, Jiunn-Jong; Lin, Ming T; Liu, Ching-Chuan

    2009-08-01

    A total of 242 isolates were recovered from 76 patients with invasive diseases, 89 with scarlet fever, and 77 with pharyngitis. The most frequent emm types were types 12 (43.4%), 4 (18.2%), and 1 (16.9%). emm12 reemerged in 2005 and peaked in 2007. emm11 was recovered only from patients with invasive disease.

  19. Revelation of susceptibility differences due to Hg(II) accumulation in Streptococcus pyogenes against CX-AgNPs and Cefixime by atomic force microscopy.

    Science.gov (United States)

    Rasheed, Wasia; Shah, Muhammad Raza; Perveen, Samina; Ahmed, Shakil; Uzzaman, Sami

    2018-01-01

    Solution based method for the formation of chemically modified silver nanoparticles (CX-AgNPs) using Cefixime as stabilizing and reducing agent was developed. The CX-AgNPs were characterized by AFM, UV-visible, FT-IR and MALDI-TOF MS. Bactericidal efficiency of CX-AgNPs and Cefixime against Streptococcus pyogenes was evaluated. Afterwards, susceptibility differences of Streptococcus pyogenes due to accumulation of Hg(II) against CX-AgNPs and Cefixime were estimated and validated through Atomic force microscopy. Selectivity and sensitivity of CX-AgNPs against Hg(II) was evaluated in a systematic manner. The CX-AgNPs was titrated against optically silent Hg(II) which induced enhancement in the SPR band of CX-AgNPs. The increase in intensity of SPR band of CX-AgNPs was determined to be proportionate to the concentration of Hg(II) in the range of 33.3-700µM obeying linear regression equation of y = 0.125x + 8.962 with the detection limit of 0.10µM and the coefficient of determination equals to 0.985 (n = 3). The association constant Ka of CX-AgNPs-Hg(II) was found to be 386.0095mol -1 dm 3 by using the Benesi Hildebrand plot. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2016-11-01

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

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

    NARCIS (Netherlands)

    W.T. Hendriksen (Wouter)

    2010-01-01

    textabstractStreptococcus pneumoniae (the pneumococcus) is a Gram-positive bacterium, which belongs to the species of streptococci. Other pathogenic bacteria belonging to this class include Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus suis, Streptococcus uberis, Streptococcus

  2. Differentiation of Streptococcus pneumoniae conjunctivitis outbreak isolates by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

    Science.gov (United States)

    Williamson, Yulanda M; Moura, Hercules; Woolfitt, Adrian R; Pirkle, James L; Barr, John R; Carvalho, Maria Da Gloria; Ades, Edwin P; Carlone, George M; Sampson, Jacquelyn S

    2008-10-01

    Streptococcus pneumoniae (pneumococcus [Pnc]) is a causative agent of many infectious diseases, including pneumonia, septicemia, otitis media, and conjunctivitis. There have been documented conjunctivitis outbreaks in which nontypeable (NT), nonencapsulated Pnc has been identified as the etiological agent. The use of mass spectrometry to comparatively and differentially analyze protein and peptide profiles of whole-cell microorganisms remains somewhat uncharted. In this report, we discuss a comparative proteomic analysis between NT S. pneumoniae conjunctivitis outbreak strains (cPnc) and other known typeable or NT pneumococcal and streptococcal isolates (including Pnc TIGR4 and R6, Streptococcus oralis, Streptococcus mitis, Streptococcus pseudopneumoniae, and Streptococcus pyogenes) and nonstreptococcal isolates (including Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus) as controls. cPnc cells and controls were grown to mid-log phase, harvested, and subsequently treated with a 10% trifluoroacetic acid-sinapinic acid matrix mixture. Protein and peptide fragments of the whole-cell bacterial isolate-matrix combinations ranging in size from 2 to 14 kDa were evaluated by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Additionally Random Forest analytical tools and dendrogramic representations (Genesis) suggested similarities and clustered the isolates into distinct clonal groups, respectively. Also, a peak list of protein and peptide masses was obtained and compared to a known Pnc protein mass library, in which a peptide common and unique to cPnc isolates was tentatively identified. Information gained from this study will lead to the identification and validation of proteins that are commonly and exclusively expressed in cPnc strains which could potentially be used as a biomarker in the rapid diagnosis of pneumococcal conjunctivitis.

  3. Aspectos clínico-epidemiológicos de las infecciones por Streptococcus pyogenes en el período neonatal Clinical and epidemiological aspects of the infections caused by Streptococcus pyogenes in the neonatal period

    Directory of Open Access Journals (Sweden)

    Manuel Díaz Alvarez

    2008-03-01

    included consecutive newborn infants who had infections caused by group A Streptococcus and that were admitted in the neonatology service of "Juan M. Márquez" Pediatric Teaching Hospital between 1992 and 2005 was carried out. Different clinical and epidemiological variables were processed and analyzed by calculating the incidence and lethality rates. RESULTS. 20 newborn infants with infection caused by group A Streptococcus were registered, accounting for an annual average rate of 0.2 per 100 admissions. This infection shows an incidence with a significant trend to decrease in the last years. According to the classification used, all the infections had a late onset, and regarding their origin those acquired in the community prevailed (95.0 %. The infection of the soft tissues was the most common clinical form (10 of 20; 50 % and evolved with bacteremia. The isolations of group A Streptococcus has 100 % of sensitivity to betalactamics. Only one patient affected with meningitis died, which represented a lethality rate of 5.0 %. CONCLUSIONS. The group A Streptococcus is an agent causing infections that affect the newborn infant, mainly in the community environment. These infections may be lethal in some patients with infection of the central nervous system, in spite of the pattern of elevated susceptibility to betalactamics.

  4. Susceptibility Pattern of Nasopharyngeal Isolates of Streptococcus ...

    African Journals Online (AJOL)

    Aims: To determine the rate of nasopharyngeal colonization of Streptococcus pneumoniae among nursery school children in Enugu urban and to determine their antibiotic susceptibility pattern particularly the penicillin resistant strains. Methods: Specimens were collected from the nasopharynx of 385 apparently healthy ...

  5. Species identification of Streptococcus bovis group isolates causing bacteremia

    DEFF Research Database (Denmark)

    Agergaard, Charlotte N; Knudsen, Elisa; Dargis, Rimtas

    2017-01-01

    This study compared two MALDI-TOF MS systems (Biotyper and VITEK MS) on clinical Streptococcus bovis group isolates (n=66). The VITEK MS gave fewer misidentifications and a higher rate of correct identifications than the Biotyper. Only the identification of S. lutetiensis by the VITEK MS was reli......This study compared two MALDI-TOF MS systems (Biotyper and VITEK MS) on clinical Streptococcus bovis group isolates (n=66). The VITEK MS gave fewer misidentifications and a higher rate of correct identifications than the Biotyper. Only the identification of S. lutetiensis by the VITEK MS...

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

    Science.gov (United States)

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

    2014-07-01

    Two catalase- and oxidase-negative Streptococcus-like strains, LMG 27682(T) and LMG 27684(T), were isolated from raw camel milk in Morocco. Comparative 16S rRNA gene sequencing assigned these bacteria to the genus Streptococcus with Streptococcus rupicaprae 2777-2-07(T) as their closest phylogenetic neighbour (95.9% and 95.7% similarity, respectively). 16S rRNA gene sequence similarity between the two strains was 96.7%. Although strains LMG 27682(T) and LMG 27684(T) shared a DNA-DNA hybridization value that corresponded to the threshold level for species delineation (68%), the two strains could be distinguished by multiple biochemical tests, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes and by their MALDI-TOF MS profiles. On the basis of these considerable phenotypic and genotypic differences, we propose to classify both strains as novel species of the genus Streptococcus, for which the names Streptococcus moroccensis sp. nov. (type strain, LMG 27682(T)  = CCMM B831(T)) and Streptococcus rifensis sp. nov. (type strain, LMG 27684(T)  = CCMM B833(T)) are proposed. © 2014 IUMS.

  7. Streptococcus porci sp. nov., isolated from swine sources.

    Science.gov (United States)

    Vela, A I; Perez, M; Zamora, L; Palacios, L; Domínguez, L; Fernández-Garayzábal, J F

    2010-01-01

    Two unidentified Gram-positive, catalase-negative, coccus-shaped organisms were recovered from pigs and subjected to a polyphasic taxonomic analysis. Based on cellular morphology and biochemical criteria, the isolates were tentatively assigned to the genus Streptococcus, although the organisms did not appear to correspond to any recognized species. Comparative 16S rRNA gene sequence studies confirmed this identification and showed that the nearest phylogenetic relatives of the unknown cocci were Streptococcus plurextorum 1956-02(T) and Streptococcus suis NCTC 10234(T) (97.9 and 96.0 % 16S rRNA gene sequence similarity, respectively). The new isolates were related most closely to S. suis CIP 103217(T) based on rpoB gene sequence analysis (<8 % sequence divergence). DNA-DNA pairing studies showed that one of the unidentified strains (2923-03(T)) displayed DNA relatedness values of 26.6 and 27.2 % with S. plurextorum CECT 7308(T) and S. suis NCTC 10234(T), respectively. On the basis of phenotypic and phylogenetic evidence, it is proposed that the unknown isolates from pigs be classified in the genus Streptococcus as members of Streptococcus porci sp. nov., with the type strain 2923-03(T) (=CECT 7374(T) =CCUG 55896(T)).

  8. Antimicrobial resistance of bacterial strains isolated from orange ...

    African Journals Online (AJOL)

    The organisms encountered include Saccharomyces cerevisiae, Saccharomyces sp, Rhodotorula sp, Bacillus cereus, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes and Micrococcus sp. The resistances of thirty bacterial strains isolated from orange juice products to the commonly used ...

  9. Is there any difference in pyogenic liver abscess caused by Streptococcus milleri and Klebsiella spp?: retrospective analysis over a 10-year period in a regional hospital.

    Science.gov (United States)

    Law, Siu-Tong; Kong Li, Michael Kin

    2013-02-01

    To compare the clinical characteristics of patients with Streptococcus milleri (SM) and Klebsiella spp. associated pyogenic liver abscess (PLA). A retrospective study of patients with PLA due to SM and Klebsiella spp. was conducted. Clinical characteristics, laboratory and radiological features, management and outcomes were analyzed. From 2000 to 2009 inclusive, 21 and 140 patients had SM and Klebsiella spp. associated monomicrobial infected PLA, respectively. A higher incidence of active malignancy occurred in the SM group (14.3% vs. 3.6%, p Klebsiella spp. associated PLA tended to have more complications: bacteremia (61.6% vs. 31.6%, p Klebsiella spp. with regard to risk factors, clinical manifestations and complications. However, both can be effectively treated with a combination of antibiotics and image-guided aspiration with/without drainage. Copyright © 2011. Published by Elsevier B.V.

  10. SpxA1 and SpxA2 Act Coordinately To Fine-Tune Stress Responses and Virulence in Streptococcus pyogenes.

    Science.gov (United States)

    Port, Gary C; Cusumano, Zachary T; Tumminello, Paul R; Caparon, Michael G

    2017-03-28

    SpxA is a unique transcriptional regulator highly conserved among members of the phylum Firmicutes that binds RNA polymerase and can act as an antiactivator. Why some Firmicutes members have two highly similar SpxA paralogs is not understood. Here, we show that the SpxA paralogs of the pathogen Streptococcus pyogenes , SpxA1 and SpxA2, act coordinately to regulate virulence by fine-tuning toxin expression and stress resistance. Construction and analysis of mutants revealed that SpxA1 - mutants were defective for growth under aerobic conditions, while SpxA2 - mutants had severely attenuated responses to multiple stresses, including thermal and oxidative stresses. SpxA1 - mutants had enhanced resistance to the cationic antimicrobial molecule polymyxin B, while SpxA2 - mutants were more sensitive. In a murine model of soft tissue infection, a SpxA1 - mutant was highly attenuated. In contrast, the highly stress-sensitive SpxA2 - mutant was hypervirulent, exhibiting more extensive tissue damage and a greater bacterial burden than the wild-type strain. SpxA1 - attenuation was associated with reduced expression of several toxins, including the SpeB cysteine protease. In contrast, SpxA2 - hypervirulence correlated with toxin overexpression and could be suppressed to wild-type levels by deletion of speB These data show that SpxA1 and SpxA2 have opposing roles in virulence and stress resistance, suggesting that they act coordinately to fine-tune toxin expression in response to stress. SpxA2 - hypervirulence also shows that stress resistance is not always essential for S. pyogenes pathogenesis in soft tissue. IMPORTANCE For many pathogens, it is generally assumed that stress resistance is essential for pathogenesis. For Streptococcus pyogenes , environmental stress is also used as a signal to alter toxin expression. The amount of stress likely informs the bacterium of the strength of the host's defense response, allowing it to adjust its toxin expression to produce the ideal

  11. Pyogenic sacroiliitis

    International Nuclear Information System (INIS)

    Gordon, G.; Kabins, S.A.

    1980-01-01

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

  12. The PerR-Regulated P1B-4-Type ATPase (PmtA) Acts as a Ferrous Iron Efflux Pump in Streptococcus pyogenes.

    Science.gov (United States)

    Turner, Andrew G; Ong, Cheryl-Lynn Y; Djoko, Karrera Y; West, Nicholas P; Davies, Mark R; McEwan, Alastair G; Walker, Mark J

    2017-06-01

    Streptococcus pyogenes (group A Streptococcus [GAS]) is an obligate human pathogen responsible for a broad spectrum of human disease. GAS has a requirement for metal homeostasis within the human host and, as such, tightly modulates metal uptake and efflux during infection. Metal acquisition systems are required to combat metal sequestration by the host, while metal efflux systems are essential to protect against metal overload poisoning. Here, we investigated the function of PmtA ( P erR-regulated m etal t ransporter A ), a P 1B-4 -type ATPase efflux pump, in invasive GAS M1T1 strain 5448. We reveal that PmtA functions as a ferrous iron [Fe(II)] efflux system. In the presence of high Fe(II) concentrations, the 5448Δ pmtA deletion mutant exhibited diminished growth and accumulated 5-fold-higher levels of intracellular Fe(II) than did the wild type and the complemented mutant. The 5448Δ pmtA deletion mutant also showed enhanced susceptibility to killing by the Fe-dependent antibiotic streptonigrin as well as increased sensitivity to hydrogen peroxide and superoxide. We suggest that the PerR-mediated control of Fe(II) efflux by PmtA is important for bacterial defense against oxidative stress. PmtA represents an exemplar for an Fe(II) efflux system in a host-adapted Gram-positive bacterial pathogen. Copyright © 2017 American Society for Microbiology.

  13. Long-term antibody memory induced by synthetic peptide vaccination is protective against Streptococcus pyogenes infection and is independent of memory T cell help.

    Science.gov (United States)

    Pandey, Manisha; Wykes, Michelle N; Hartas, Jon; Good, Michael F; Batzloff, Michael R

    2013-03-15

    Streptococcus pyogenes (group A Streptococcus [GAS]) is a leading human pathogen associated with a diverse array of mucosal and systemic infections. Vaccination with J8, a conserved region synthetic peptide derived from the M-protein of GAS and containing only 12 aa from GAS, when conjugated to diphtheria toxoid, has been shown to protect mice against a lethal GAS challenge. Protection has been previously shown to be Ab-mediated. J8 does not contain a dominant GAS-specific T cell epitope. The current study examined long-term Ab memory and dissected the role of B and T cells. Our results demonstrated that vaccination generates specific memory B cells (MBC) and long-lasting Ab responses. The MBC response can be activated following boost with Ag or limiting numbers of whole bacteria. We further show that these memory responses protect against systemic infection with GAS. T cell help is required for activation of MBC but can be provided by naive T cells responding directly to GAS at the time of infection. Thus, individuals whose T cells do not recognize the short synthetic peptide in the vaccine will be able to generate a protective and rapid memory Ab response at the time of infection. These studies significantly strengthen previous findings, which showed that protection by the J8-diphtheria toxoid vaccine is Ab-mediated and suggest that in vaccine design for other organisms the source of T cell help for Ab responses need not be limited to sequences from the organism itself.

  14. Celulitis orbitaria complicada por absceso subperióstico debido a infección por Streptococcus pyogenes

    OpenAIRE

    José Daniel Ruíz Carrillo; Edwin Vázquez Guerrero; Mónica Cecilia Mercado Uribe

    2017-01-01

    Introducción: La celulitis orbitaria es una enfermedad infecciosa muy frecuente en la edad pediátrica que puede provocar el desarrollo de severas complicaciones. Los principales microorganismos involucrados son Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae y Moraxella catarrhalis, que juntos corresponden al 95% de los casos. También se pueden presentar Streptococcus beta hemolíticos y microorganismos anaerobios, que corresponden a menos del 5% de los casos. Se presen...

  15. Trueperella pyogenes isolated from dairy cows with endometritis in Inner Mongolia, China: Tetracycline susceptibility and tetracycline-resistance gene distribution.

    Science.gov (United States)

    Zhang, Dexian; Zhao, Jingcui; Wang, Qiuxia; Liu, Yaochuan; Tian, Chunlian; Zhao, Yujun; Yu, Lihui; Liu, Mingchun

    2017-04-01

    Trueperella pyogenes plays a crucial role in endometritis pathogenesis and is also associated with many infections, including metritis, mastitis, arthritis and liver abscessation, in many domestic animals. In this study, we investigated the prevalence of tetracycline resistance in T. pyogenes isolated from dairy cows with endometritis in Inner Mongolia, China, and we assessed tetracycline-resistance gene distribution among the isolates. Our results indicated that 68.7% and 62.5% of the isolates were resistant to tetracycline and doxycycline, respectively, and the rate of resistance to metacycline was 18.8%. The tetracycline resistance gene tetK was present in all isolates (n = 32), whereas the tetM gene was identified in 12.5% and 9.4% of the isolates, in the chromosome and plasmid, respectively. Strains carrying tetW were also common in the chromosome and plasmid, with abundances of 53.1% and 46.9%, respectively. However, tetO and otrA were absent in all isolates. The resistance phenotype analysis indicated that 6.3% of strains were susceptible to all tetracyclines, while 3.1% showed resistance to all tetracyclines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Celulitis orbitaria complicada por absceso subperióstico debido a infección por Streptococcus pyogenes

    Directory of Open Access Journals (Sweden)

    José Daniel Ruíz Carrillo

    2017-03-01

    Conclusiones: Debido a la implementación de los esquemas de vacunación desde la década de los 90 contra H. influenza y S. pneumoniae, los casos por estos patógenos han disminuido, provocando que nuevas bacterias tomen su lugar como causantes de la infección. La importancia de considerar a S. pyogenes como etiología de celulitis orbitaria radica en la rápida progresión para la formación de abscesos, así como los pocos casos descritos en la literatura.

  17. Streptococcus bovimastitidis sp. nov., isolated from a dairy cow with mastitis.

    Science.gov (United States)

    de Vries, Stefan P W; Hadjirin, Nazreen F; Lay, Elizabeth M; Zadoks, Ruth N; Peacock, Sharon J; Parkhill, Julian; Grant, Andrew J; McDougall, Scott; Holmes, Mark A

    2018-01-01

    Here we describe a new species of the genus Streptococcus that was isolated from a dairy cow with mastitis in New Zealand. Strain NZ1587 T was Gram-positive, coccus-shaped and arranged as chains, catalase and coagulase negative, γ-haemolytic and negative for Lancefield carbohydrates (A-D, F and G). The 16S rRNA sequence did not match sequences in the NCBI 16S rRNA or GreenGenes databases. Taxonomic classification of strain NZ1587 T was investigated using 16S rRNA and core genome phylogeny, genome-wide average nucleotide identity (ANI) and predicted DNA-DNA hybridisation (DDH) analyses. Phylogeny based on 16S rRNA was unable to resolve the taxonomic position of strain NZ1587 T , however NZ1587 T shared 99.4 % identity at the 16S rRNA level with a distinct branch of S. pseudoporcinus. Importantly, core genome phylogeny demonstrated that NZ1587 T grouped amongst the 'pyogenic' streptococcal species and formed a distinct branch supported by a 100 % bootstrap value. In addition, average nucleotide identity and inferred DNA-DNA hybridisation analyses showed that NZ1587 T represents a novel species. Biochemical profiling using the rapid ID 32 strep identification test enabled differentiation of strain NZ1587 T from closely related streptococcal species. In conclusion, strain NZ1587 T can be classified as a novel species, and we propose a novel taxon named Streptococcus bovimastitidis sp. nov.; the type strain is NZ1587 T . NZ1587 T has been deposited in the Culture Collection University of Gothenburg (CCUG 69277 T ) and the Belgian Co-ordinated Collections of Micro-organisms/LMG (LMG 29747).

  18. Isolation of genes involved in biofilm formation of a Klebsiella pneumoniae strain causing pyogenic liver abscess.

    Directory of Open Access Journals (Sweden)

    Meng-Chuan Wu

    Full Text Available BACKGROUND: Community-acquired pyogenic liver abscess (PLA complicated with meningitis and endophthalmitis caused by Klebsiella pneumoniae is an emerging infectious disease. To investigate the mechanisms and effects of biofilm formation of K. pneumoniae causing PLA, microtiter plate assays were used to determine the levels of biofilm formed by K. pneumoniae clinical isolates and to screen for biofilm-altered mutants from a transposon mutant library of a K. pneumoniae PLA-associated strain. METHODOLOGY/PRINCIPAL FINDINGS: The biofilm formation of K. pneumoniae was examined by microtiter plate assay. Higher levels of biofilm formation were demonstrated by K. pneumoniae strains associated with PLA. A total of 23 biofilm-decreased mutants and 4 biofilm-increased mutants were identified. Among these mutants, a biofilm-decreased treC mutant displayed less mucoviscosity and produced less capsular polysaccharide (CPS, whereas a biofilm-increased sugE mutant displayed higher mucoviscosity and produced more CPS. The biofilm phenotypes of treC and sugE mutants also were confirmed by glass slide culture. Deletion of treC, which encodes trehalose-6-phosphate hydrolase, impaired bacterial trehalose utilization. Addition of glucose to the culture medium restored the capsule production and biofilm formation in the treC mutant. Transcriptional profile analysis suggested that the increase of CPS production in ΔsugE may reflect elevated cps gene expression (upregulated through rmpA in combination with increased treC expression. In vivo competition assays demonstrated that the treC mutant strain was attenuated in competitiveness during intragastric infection in mice. CONCLUSIONS/SIGNIFICANCE: Genes important for biofilm formation by K. pneumoniae PLA strain were identified using an in vitro assay. Among the identified genes, treC and sugE affect biofilm formation by modulating CPS production. The importance of treC in gastrointestinal tract colonization suggests

  19. Use of a Phosphorylation Site Mutant To Identify Distinct Modes of Gene Repression by the Control of Virulence Regulator (CovR) in Streptococcus pyogenes.

    Science.gov (United States)

    Horstmann, Nicola; Sahasrabhojane, Pranoti; Yao, Hui; Su, Xiaoping; Shelburne, Samuel A

    2017-09-15

    Control of the virulence regulator/sensor kinase (CovRS) two-component system (TCS) serves as a model for investigating the impact of signaling pathways on the pathogenesis of Gram-positive bacteria. However, the molecular mechanisms by which CovR, an OmpR/PhoB family response regulator, controls virulence gene expression are poorly defined, partly due to the labile nature of its aspartate phosphorylation site. To better understand the regulatory effect of phosphorylated CovR, we generated the phosphorylation site mutant strain 10870-CovR-D53E, which we predicted to have a constitutive CovR phosphorylation phenotype. Interestingly, this strain showed CovR activity only for a subset of the CovR regulon, which allowed for classification of CovR-influenced genes into D53E-regulated and D53E-nonregulated groups. Inspection of the promoter sequences of genes belonging to each group revealed distinct promoter architectures with respect to the location and number of putative CovR-binding sites. Electrophoretic mobility shift analysis demonstrated that recombinant CovR-D53E protein retains its ability to bind promoter DNA from both CovR-D53E-regulated and -nonregulated groups, implying that factors other than mere DNA binding are crucial for gene regulation. In fact, we found that CovR-D53E is incapable of dimerization, a process thought to be critical to OmpR/PhoB family regulator function. Thus, our global analysis of CovR-D53E indicates dimerization-dependent and dimerization-independent modes of CovR-mediated repression, thereby establishing distinct mechanisms by which this critical regulator coordinates virulence gene expression. IMPORTANCE Streptococcus pyogenes causes a wide variety of diseases, ranging from superficial skin and throat infections to life-threatening invasive infections. To establish these various disease manifestations, Streptococcus pyogenes requires tightly coordinated production of its virulence factor repertoire. Here, the response regulator

  20. Isolation and Typing of Streptococcus mutans and Streptococcus sobrinus from Caries-active Subjects.

    Science.gov (United States)

    Salman, Hamzah Abdulrahman; Senthilkumar, R; Imran, Khalid; Selvam, K Panneer

    2017-01-01

    Streptococcus mutans and Streptococcus sobrinus are main etiological agents of dental caries. The aim of the study was to isolate, identify, characterize, and determine the minimum inhibitory concentration (MIC) of S. mutans and S. sobrinus from caries-active subjects. Sixty-five plaque samples were collected from caries-active subjects aged between 35 and 44 years, processed and cultured on mitis salivarius bacitracin agar. All the bacterial isolates were subjected to morphotyping and the suspected colonies were identified by 16S rDNA sequencing. The S. mutans and S. sobrinus strains were characterized by biotyping and phylogenetic analysis. The MIC of ampicillin and erythromycin was determined by microtiter plate method. Of the study population, 41 isolates displayed typical colony morphologies of S. mutans and S. sobrinus . The 16S rDNA sequencing results revealed that 36 isolates were S. mutans and 5 isolates were S. sobrinus . The biotyping of these isolates demonstrated three biotypes, namely, biotype I ( n = 35), biotype III ( n = 1), and biotype IV ( n = 2). However, 3 isolates exhibited variant biotypes. The phylogenetic analysis revealed that the clinical strains of S. mutans and S. sobrinus clustered independently along with respective reference strains. The average MIC of ampicillin and erythromycin against S. mutans and S. sobrinus was 0.047 μg/ml and 0.39 μg/ml, respectively. The 16S rDNA sequencing was an impeccable method for S. mutans and S. sobrinus identification when compared with morphotyping and biotyping methods. The study also suggested that nonspecific bacteria might be involved in caries formation.

  1. Isolation and typing of Streptococcus mutans and Streptococcus sobrinus from caries-active subjects

    Directory of Open Access Journals (Sweden)

    Hamzah Abdulrahman Salman

    2017-01-01

    Full Text Available Background: Streptococcus mutans and Streptococcus sobrinus are main etiological agents of dental caries. Aim: The aim of the study was to isolate, identify, characterize, and determine the minimum inhibitory concentration (MIC of S. mutans and S. sobrinus from caries-active subjects. Materials and Methods: Sixty-five plaque samples were collected from caries-active subjects aged between 35 and 44 years, processed and cultured on mitis salivarius bacitracin agar. All the bacterial isolates were subjected to morphotyping and the suspected colonies were identified by 16S rDNA sequencing. The S. mutans and S. sobrinus strains were characterized by biotyping and phylogenetic analysis. The MIC of ampicillin and erythromycin was determined by microtiter plate method. Results: Of the study population, 41 isolates displayed typical colony morphologies of S. mutans and S. sobrinus. The 16S rDNA sequencing results revealed that 36 isolates were S. mutans and 5 isolates were S. sobrinus. The biotyping of these isolates demonstrated three biotypes, namely, biotype I (n = 35, biotype III (n = 1, and biotype IV (n = 2. However, 3 isolates exhibited variant biotypes. The phylogenetic analysis revealed that the clinical strains of S. mutans and S. sobrinus clustered independently along with respective reference strains. The average MIC of ampicillin and erythromycin against S. mutans and S. sobrinus was 0.047 μg/ml and 0.39 μg/ml, respectively. Conclusion: The 16S rDNA sequencing was an impeccable method for S. mutans and S. sobrinus identification when compared with morphotyping and biotyping methods. The study also suggested that nonspecific bacteria might be involved in caries formation.

  2. Meningitis neonatal por Streptococcus pyogenes y revisión de la literatura de los últimos 50 años Neonatal meningitis caused by Streptococcus pyogenes and literature review of the last 50 years

    Directory of Open Access Journals (Sweden)

    Manuel Díaz Alvarez

    2008-06-01

    Full Text Available Se describe el caso de un recién nacido fallecido a causa de meningitis bacteriana por estreptococo del grupo A. Se revisó la literatura mediante la búsqueda en distintas bases de datos y otras fuentes de los últimos 50 años. Antes de la publicación de este caso, se han documentado casos de otros 20 neonatos con meningitis bacteriana por estreptococo del grupo A y se halla la descripción clínica de ellos desde el año 1957. En otros artículos al mostrar la casuística de sepsis o meningitis neonatal, en general, reportan casos de recién nacidos con esta infección ocasionada por estreptococos del grupo A, pero no se ofrece información detallada de los casos. Según las publicaciones citadas, se demuestra que, aunque en la actualidad el estreptococo del grupo A no es ya un azote en el período neonatal, puede considerarse entre los microorganismos causales de meningitis bacteriana neonatal.The case of a newborn infant who died of bacterial meningitis caused by streptococcus of the group A was described. The literature was reviewed by searching different databases and other sources of the last 50 years. Before publishing this case, cases of other 20 neonates with bacterial meningitis due to streptococcus of the group A have been documented and their clinical description has been made since 1957. Other articles show the casuistics of sepsis or neonatal meningitis in general by reporting cases of newborns with this infection produced by streptococcus of group A, but no detailed information of the cases is provided. According to the publications cited, it was proved that in spite of the fact that at present streptococcus is not a hazard in the neonatal period, it may be considered among the microorganisms causing neonatal bacterial meningitis.

  3. Identification and characterization of two temperature-induced surface-associated proteins of Streptococcus suis with high homologies to members of the arginine deiminase system of Streptococcus pyogenes

    NARCIS (Netherlands)

    Winterhoff, N.; Goethe, R.; Gruening, P.; Rohde, M.; Kalisz, H.; Smith, H.E.; Valentin-Weigand, P.

    2002-01-01

    The present study was performed to identify stress-induced putative virulence proteins of Streptococcus suis. For this, protein expression patterns of streptococci grown at 32, 37, and 42°C were compared by one- and two-dimensional gel electrophoresis. Temperature shifts from 32 and 37 to 42°C

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

    Science.gov (United States)

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

    2016-04-01

    The aim of this study was to investigate the antibacterial resistance of Streptococcus pyogenes (GAS), and correlate the findings with the sales of erythromycin and tetracycline. General practitioners in the Faroe Islands were recruited to send oropharyngeal swabs. From an ongoing pneumococcal study, nasopharyngeal swabs were sampled from healthy children 0-7 years of age. Erythromycin susceptibility data from Iceland were obtained from the reference laboratory at the Landspitali University Hospital. Susceptibility testing in the Faroe Islands and Iceland was performed according to CLSI methods and criteria. The resistance rate to erythromycin and tetracycline found in patients in the Faroe Islands in 2009/2010 was 6% and 30% respectively. Tetracycline resistance in patients declined significantly from 2009 to 2010 (37-10%, p-value = 0.006 < 0.05) and differed significantly between age groups (p-value = 0.03 < 0.05). In Iceland, there was a peak in erythromycin resistance in 2008 (44%) and a substantial decrease in 2009 (5%). Although the prevalence of erythromycin and tetracycline resistance in the Faroe Islands and Iceland may be associated with antimicrobial use, sudden changes can occur with the introduction of new resistant clones. © 2016 APMIS. Published by John Wiley & Sons Ltd.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-05

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

  6. Purification and characterization of erythrogenic toxins of Streptococcus pyogenes. VI. Mitogenic activity of isoelectrically focused erythrogenic toxin preparations and culture supernatants of group A streptococci.

    Science.gov (United States)

    Knöll, H; Gerlach, D; Ozegowski, J H; Hribalová, V; Köhler, W

    1983-11-01

    Isoelectric focusing (IF) was used to separate erythrogenic toxins (ET) type A, B and C from concentrated culture filtrates of Streptococcus pyogenes strains. The ET's were identified by their mitogenic activity on human lymphocytes in the lymphocyte transformation test: purified ET type A appeared at pH 5.3, ET type C at pH 6.8 and ET type B at pH 7.5 to 8.5; the ET type B was only biologically active when PAGE IF was used. IF on Sephadex G 100 failed to yield active B toxin. The application of as little as 0.1 micrograms ET type A to an isoelectric focusing gel was still sufficient to detect a mitogenic peak in the eluates. ET type A was identified in nine out of 10 culture filtrates, ET type C in 4 out of 10. Detection of ET type B (identical with streptococcal proteinase proenzyme) in culture filtrates after IF proved to be difficult. Here the pH of cultivation media and the autocatalytic conversion of streptococcal proteinase proenzyme to activated proteinase have to be considered.

  7. EFFECT OF THE ESSENTIAL OIL, INFUSION AND ETHANOL EXTRACT OF Thymus vulgaris L., ON THE GROWTH IN VITRO OF GROUP A ß-HEMOLYTIC Streptococcus pyogenes

    Directory of Open Access Journals (Sweden)

    Eloy Solano

    2006-01-01

    Full Text Available Se estimó un tratamiento alternativo de bajo costo para conocer la efectividad del tomillo Thymus vulgaris L., sobre la faringoamigdalitis bacteriana. Al aceite esencial obtenido por destilación, extracto etanólico e infusión de tomillo; se les evaluó su actividad biológica sobre el crecimiento de Streptococcus pyogenes ß-hemolítico del grupo A de Lancefield, principal causante de la faringoamigdalitis. Se realizaron pruebas de sensibilidad y se midieron las zonas de inhibición in vitro. El aceite esencial destilado, registró el mayor halo de inhibición (3.2 cm, incluso superó a la penicilina (2.4 cm. Con el extracto etanólico la inhibición fue menor y con la infusión no hubo inhibición. El aceite esencial y el extracto etanólico fueron analizados por medio de cromatografía en capa fina y cromatografía de gases para determinar su concentración y pureza en comparación con el aceite escencial puro de tomillo, obteniéndose la presencia de timol y en menor grado carvacrol, agentes activos que producen inhibición en el crecimiento bacteriano.

  8. Genetic patterns of Streptococcus uberis isolated from bovine mastitis

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    Elina B Reinoso

    2015-06-01

    Full Text Available The aim of this study was to evaluate the genotypic relationships among 40 Streptococcus uberis isolated from bovine mastitis by using pulsed-field gel electrophoresis (PFGE. Additionally, the association between PFGE patterns and virulence profiles was investigated. The isolates exhibited 17 PFGE patterns. Different strains were found within and among herds; however, a low number of isolates within the same herd shared an identical PFGE type. No association between PFGE patterns and virulence profiles was found. However, the detection of specific strains in some herds could indicate that some strains are more virulent than others. Further research needs to be undertaken to elucidate new virulence-associated genes that might contribute to the capability of these strains to produce infection.

  9. Genetic patterns of Streptococcus uberis isolated from bovine mastitis.

    Science.gov (United States)

    Reinoso, Elina B; Lasagno, Mirta C; Odierno, Liliana M

    2015-01-01

    The aim of this study was to evaluate the genotypic relationships among 40 Streptococcus uberis isolated from bovine mastitis by using pulsed-field gel electrophoresis (PFGE). Additionally, the association between PFGE patterns and virulence profiles was investigated. The isolates exhibited 17 PFGE patterns. Different strains were found within and among herds; however, a low number of isolates within the same herd shared an identical PFGE type. No association between PFGE patterns and virulence profiles was found. However, the detection of specific strains in some herds could indicate that some strains are more virulent than others. Further research needs to be undertaken to elucidate new virulence-associated genes that might contribute to the capability of these strains to produce infection. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. 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.

    Science.gov (United States)

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

    2013-09-01

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

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

    Science.gov (United States)

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

    2017-05-01

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

  12. Antibiotic Susceptibilities and Serotyping of Clinical Streptococcus Agalactiae Isolates

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    Altay Atalay

    2011-11-01

    Full Text Available Objective: Streptococcus agalactiae (Group B streptococci, GBS are frequently responsible for sepsis and meningitis seen in the early weeks of life. GBS may cause perinatal infection and premature birth in pregnant women. The aim of this study was to serotype GBS strains isolated from clinical samples and evaluate their serotype distribution according to their susceptibilities to antibiotics and isolation sites. Material and Methods: One hundred thirty one S. agalactiae strains isolated from the clinical samples were included in the study. Of the strains, 99 were isolated from urine, 20 from soft tissue, 10 from blood and 2 from vaginal swab. Penicillin G and ceftriaxone susceptibilities of GBS were determined by the agar dilution method. Susceptibilities to erythromycin, clindamycin, vancomycin and tetracycline were determined by the Kirby-Bauer method according to CLSI criteria. Serotyping was performed using the latex aglutination method using specific antisera (Ia, Ib, II-VIII. Results: While in 131 GBS strains, serotypes VII and VIII were not detected, the most frequently isolated serotypes were types Ia (36%, III (30.5% and II (13% respectively. Serotype Ia was the most frequently seen serotype in all samples. All GBS isolates were susceptible to penicilin G, ceftriaxone and vancomycin. Among the strains, tetracycline, erythromycin and clindamycin resistance rates were determined as 90%, 14.5%, and 13% respectively. Conclusion: Penicillin is still the first choice of treatment for the infections with all serotypes of S. agalactiae in Turkey.

  13. Identification of Isolates of Streptococcus canis Infecting Humans

    Science.gov (United States)

    Whatmore, Adrian M.; Engler, Kathryn H.; Gudmundsdottir, Gudny; Efstratiou, Androulla

    2001-01-01

    During a survey of Group G and C streptococcal infections of humans two epidemiologically unrelated Group G streptococcal isolates were identified, one from a case of bacteremia and one from a wound infection. These isolates were atypical among this sample in that the emm gene could not be amplified from them by PCR. Biochemical characterization identified the isolates as Streptococcus canis, an organism normally associated with animal hosts. The biochemical identification was confirmed by sequencing of the 16S rRNA gene from both isolates and comparison with sequences of the S. canis type strain and other related streptococci of animals and humans. Comparative sequencing of fragments of two other housekeeping genes, sodA and mutS, confirmed that the isolates are most closely related to S. canis. The identification of two isolates of S. canis from a relatively small sample set suggests that the practice of identifying streptococci only by the Lancefield serological group may result in underestimation of the presence of S. canis in the human population. PMID:11682560

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

    Science.gov (United States)

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

    2014-12-01

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

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

    Science.gov (United States)

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

    2013-09-20

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

  16. [Structural homology between streptolysin O (SLO) produced by streptococcus pyogenes and SLO-like protein produced by non-pathogenic streptococci and cross-reactivity of antibody against SLO-like protein to SLO].

    Science.gov (United States)

    Iijima, Kenji; Koike, Hisashi; Ota, Hiromi; Nakagawa, Mayumi; Nishikawa, Ken-Ichi; Kotani, Kazuhiko

    2008-08-01

    Nine clones of non-pathogenic streptococci were isolated from the pharynges of seven healthy subjects, and grown on sheep blood agar plates with a hemolysis or gamma hemolysis, then cultured in LB broth for 16 hrs. Purified streptolysin O (SLO) purchased from Sigma Chemical Co. (Sigma-SLO), SLO antigen as a latex agglutination reagent from A company (A-SLO) and supernatants from four culture media were electrophoresed on 12% SDS-polyacrylamide gel and transferred to PVDF membranes. Immunological analyses of antibodies against SLO in healthy sera and proteins in culture medium demonstrated that healthy sera contained an antibody recognizing Sigma-SLO, A-SLO and a protein of the same size as SLO (SLO-like protein) in culture medium. These findings suggest that healthy subjects develop an antibody directed against SLO-like protein produced by non-pathogenic streptococci, and that this antibody cross-reacts with Sigma-SLO and A-SLO. Using DNA from Streptococcus pyogenes and non-pathogenic streptococci, the SLO gene and SLO-like protein gene were analyzed by direct sequencing with oligonucleotide primers designed to cover no. 74 to approximately 1900 of the SLO gene. There were three different bases resulting in amino acid substitution between the SLO gene and SLO-like protein gene, namely 101Lys (AAA) of SLO to Asn (AAT), 175Met (ATG) to Arg (AGG) and 185Asp (GAT) to Asn (AAT). Remaining 560 residues of 563 amino acids constituting SLO-like protein were homologous to SLO. Non-pathogenic streptococci on the pharynges of healthy subjects produce an SLO-like protein composed of amino acids similar to those of SLO, which induces an antibody against this SLO-like protein in serum. It is likely that an antibody against SLO-like protein in healthy sera cross-reacts with SLO and causes a pseudo-positive reaction on ASO measurement by the latex agglutination method using SLO antigen.

  17. Antibiotic Susceptibility of Periodontal Streptococcus Constellatus and Streptococcus Intermedius Clinical Isolates

    NARCIS (Netherlands)

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

    2014-01-01

    Background: Streptococcus constellatus and Streptococcus intermedius in subgingival dental plaque biofilms may contribute to forms of periodontitis that resist treatment with conventional mechanical root debridement/surgical procedures and may additionally participate in some extraoral infections.

  18. Local Changes in Rates of Group A Streptococcus Disease and Antibiotic Resistance are Associated with Geographically Widespread Strain Turnover Events

    Science.gov (United States)

    2010-08-01

    253 14. ABSTRACT (maximum 200 words) Group A Streptococcus pyogenes is a primary agent of respiratory disease in military environments...COVERED (from - to) January 2007–December 2008 4. TITLE AND SUBTITLE Local Changes in Rates of Group A Streptococcus Disease and Antibiotic Resistance...antibiotic resistance of 802 Streptococcus isolates from 10 US military facilities collected from 2002 through 2007. Most of these sites provided

  19. Identification of novel growth phase- and media-dependent small non-coding RNAs in Streptococcus pyogenes M49 using intergenic tiling arrays

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    Patenge Nadja

    2012-10-01

    Full Text Available Abstract Background Small non-coding RNAs (sRNAs have attracted attention as a new class of gene regulators in both eukaryotes and bacteria. Genome-wide screening methods have been successfully applied in Gram-negative bacteria to identify sRNA regulators. Many sRNAs are well characterized, including their target mRNAs and mode of action. In comparison, little is known about sRNAs in Gram-positive pathogens. In this study, we identified novel sRNAs in the exclusively human pathogen Streptococcus pyogenes M49 (Group A Streptococcus, GAS M49, employing a whole genome intergenic tiling array approach. GAS is an important pathogen that causes diseases ranging from mild superficial infections of the skin and mucous membranes of the naso-pharynx, to severe toxic and invasive diseases. Results We identified 55 putative sRNAs in GAS M49 that were expressed during growth. Of these, 42 were novel. Some of the newly-identified sRNAs belonged to one of the common non-coding RNA families described in the Rfam database. Comparison of the results of our screen with the outcome of two recently published bioinformatics tools showed a low level of overlap between putative sRNA genes. Previously, 40 potential sRNAs have been reported to be expressed in a GAS M1T1 serotype, as detected by a whole genome intergenic tiling array approach. Our screen detected 12 putative sRNA genes that were expressed in both strains. Twenty sRNA candidates appeared to be regulated in a medium-dependent fashion, while eight sRNA genes were regulated throughout growth in chemically defined medium. Expression of candidate genes was verified by reverse transcriptase-qPCR. For a subset of sRNAs, the transcriptional start was determined by 5′ rapid amplification of cDNA ends-PCR (RACE-PCR analysis. Conclusions In accord with the results of previous studies, we found little overlap between different screening methods, which underlines the fact that a comprehensive analysis of s

  20. Label-free proteomic analysis of environmental acidification-influenced Streptococcus pyogenes secretome reveals a novel acid-induced protein histidine triad protein A (HtpA) involved in necrotizing fasciitis.

    Science.gov (United States)

    Wen, Yao-Tseng; Wang, Jie-Siou; Tsai, Shu-Han; Chuan, Chiang-Ni; Wu, Jiunn-Jong; Liao, Pao-Chi

    2014-09-23

    Streptococcus pyogenes is responsible for various diseases. During infection, bacteria must adapt to adverse environments, such as the acidic environment. Acidic stimuli may stimulate S. pyogenes to invade into deeper tissue. However, how this acidic stimulus causes S. pyogenes to manipulate its secretome for facilitating invasion remains unclear. The dynamic label-free LC-MS/MS profiling identified 97 proteins, which are influenced by environmental acidification. Among these, 33 (34%) of the identified proteins were predicted to be extracellular proteins. Interestingly, classical secretory proteins comprise approximately 90% of protein abundance of the secretome in acidic condition at the stationary phase. One acid-induced secreted protein, HtpA, was selected to investigate its role in invasive infection. The mouse infected by the htpA deficient mutant showed lower virulence and smaller lesion area than the wild-type strain. The mutant strain was more efficiently cleared at infected skin than the wild-type strain. Besides, the relative phagocytosis resistance is lower in the mutant strain than in the wild-type strain. These data indicate that a novel acid-induced virulence factor, HtpA, which improves anti-phagocytosis ability for causing necrotizing fasciitis. Our investigation provides vital information for documenting the broad influences and mechanisms underlying the invasive behavior of S. pyogenes in an acidified environment. The acidified infected environment may facilitate S. pyogenes invasion from the mucosa to the deeper subepithelial tissue. The acid stimuli have been considered to affect the complex regulatory network of S. pyogenes for causing severe infections. Many of secreted virulence factors influenced by acidified environment may also play a crucial role in pathogenesis of invasive disease. To investigate temporal secretome changes under acidic environment, a comparative secretomics approach using label-free LC-MS/MS was undertaken to analyze

  1. 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

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    Di Pierro F

    2012-11-01

    Full Text Available Francesco Di Pierro,1 Guido Donato,2 Federico Fomia,3 Teresa Adami,4 Domenico Careddu,5 Claudia Cassandro,6 Roberto Albera61Scientific Department, Velleja Research, Milano, 2ASL 1, Cuneo, 3ASL 3, Brescia, 4Infective Diseases, Verona, 5ASL 13, Novara, 6Surgical Science Department, Università degli Studi, Torino, ItalyBackground: 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

  2. 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

    International Nuclear Information System (INIS)

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

    2013-01-01

    In this study, the variable domain of the collagen-like protein Scl2 from invasive M3-type S. pyogenes has successfully been crystallized. Single-wavelength anomalous dispersion experiments have been carried out to obtain experimental phases by preparing crystal derivatives with lanthanides. Model building and refinement, which are in progress, will provide the first structural clues for Scls. 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.|

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

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    Finne Jukka

    2006-02-01

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

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

    Science.gov (United States)

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

    2015-11-01

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

  5. SUSCEPTIBILITY OF RESPIRATORY ISOLATES OF STREPTOCOCCUS PNEUMONIAE ISOLATED FROM CHILDREN HOSPITALIZED IN THE CLINICAL CENTER NIS.

    Science.gov (United States)

    Dinić, Marina M; Mladenović Antić, Snezana; Kocić, Branislava; Stanković Dordević, Dobrila; Vrbić, Miodrag; Bogdanović, Milena

    2016-01-01

    Streptococcus pneumoniae is one of the most common causes of respiratory infections. The aim was to study the susceptibility to antimicrobial agents of respiratory isolates ofStreptococcus pneumoniae obtained from hospitalized children. A total of 190 respiratory pneumococcal isolates obtained from children aged from 0 to 14 years were isolated and identified by using standard microbiological methods. Susceptibility to oxacillin, erythromycin, clindamycin, tetracycline, cotrimoxazole, ofloxacin and rifampicin was tested by disc diffusion method. Minimal inhibitory concentrations for amoxicillin and ceftriaxone were determined by means of E test. The macrolide-resistant phenotype was detected by double disc diffusion test. All tested isolates were susceptible to amoxicillin and ceftriaxone. The minimal amoxicillin concentration inhibiting the growth of 50% of isolates and of 90% of isolates was 0.50 microg/ml and 1.0 microg/ml, respectively and the minimal ceftriaxone concentration inhibiting the growth of 50% of isolates and of 90% of isolates was 0.25 microg/ml and 0.50 microg/ml, respectively. Susceptibility to erythromycin and clindamycin was observed in 21.6% and 29.47% of isolates, respectively. The resistence to macrolides-M phenotype was detected in 10.07% of isolates and constitutive macrolide-lincosamide-streptogramin phenotype (constitutive MLS phenotype) was found in 89.93% of isolates. All tested isolates were susceptible to ofloxacin and rifampicin. Amoxicillin could be the therapy of choice in pediatric practice. The macrolides should not be recommended for the empirical therapy of pneumococcal respiratory tract infection in our local area.

  6. Isolation and antibiogram of Staphylococcus, Streptococcus and Escherichia coli isolates from clinical and subclinical cases of bovine mastitis

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    Nihar Nalini Mohanty,

    2013-08-01

    Full Text Available Aim: The present study was aimed to isolate and evaluate the continuous change in the pattern of drug resistance showed by different mastitogenic organisms, isolated from clinical and subclinical cases of mastitis.Materials and Methods: The study was carried out using 150 milk samples received from various clinical and subclinical cases, from which the causative organisms were isolated and subjected to in vitro antibiotic sensitivity test.Results: The bacteriological analysis of the samples indicated the presence of both Gram positive and Gram negative organisms followed by isolation of isolates like Staphylococcus, E. coli, Streptococcus, Bacillus, Corynebacterium, Listeria, Klebsiella. The in vitro sensitivity of Staphylococcus, E. coli and Streptococcus isolates revealed that they were more sensitive towards newer antimicrobials like Levofloxacin and Enrofloxacin.Conclusion: The prevalence of Staphylococcus was found to be maximum followed by Streptococcus and E. coli among the isolated organisms. Levofloxacin and Enrofloxacin were found to be most effective against the targeted isolates.

  7. Penicillin resistance is not extrapolable to amoxicillin resistance in Streptococcus pneumoniae isolated from middle ear fluid in children with acute otitis media.

    Science.gov (United States)

    Rosenblüt, Andrés; Santolaya, María Elena; Gonzalez, Patricia; Borel, Cecilia; Cofré, José

    2006-03-01

    We evaluated the in vitro antibacterial activity of amoxicillin against penicillin-susceptible and -nonsusceptible Streptococcus pneumoniae strains isolated from children with acute otitis media (AOM). Children more than 3 months of age with AOM who were seen in the Dr Sótero del Rio and Luis Calvo Mackenna Hospitals in Santiago, Chile, between July 1998 and December 2002 were subjected to tympanic puncture for middle ear fluid culture. The penicillin and amoxicillin susceptibilities of the S pneumoniae isolates were determined by epsilometer test (E test). A bacterial pathogen was isolated in 432 of 543 children (80%) as follows: S pneumoniae, 40%; Haemophilus influenzae, 29%; Moraxella catarrhalis, 7%; and Streptococcus pyogenes, 4%. Penicillin-susceptible S pneumoniae strains were less common than amoxicillin-susceptible strains (60% versus 95%; odds ratio [OR], 0.08; 95% confidence interval [CI], 0.04 to 0.18). Both intermediate- and high-resistance strains were more common for penicillin (22% versus 4.5%; OR, 5.6; 95% CI, 2.5 to 12.7) than for amoxicillin (18% versus 0.5%; OR, 41.3; 95% CI, 6.0 to 821). Penicillin resistance is not extrapolable to amoxicillin among S pneumoniae strains isolated from middle ear fluid of children with AOM. Our results support the recommendation to evaluate the minimal inhibitory concentrations of penicillin-nonsusceptible S pneumoniae for amoxicillin and to continue use of this antimicrobial as a first-line antimicrobial choice for children with AOM.

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

    Directory of Open Access Journals (Sweden)

    Jeffrey A Mayfield

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

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

    Science.gov (United States)

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

    2014-04-08

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

  10. Phenotypic heterogeneity of genomically-diverse isolates of Streptococcus mutans.

    Directory of Open Access Journals (Sweden)

    Sara R Palmer

    Full Text Available High coverage, whole genome shotgun (WGS sequencing of 57 geographically- and genetically-diverse isolates of Streptococcus mutans from individuals of known dental caries status was recently completed. Of the 57 sequenced strains, fifteen isolates, were selected based primarily on differences in gene content and phenotypic characteristics known to affect virulence and compared with the reference strain UA159. A high degree of variability in these properties was observed between strains, with a broad spectrum of sensitivities to low pH, oxidative stress (air and paraquat and exposure to competence stimulating peptide (CSP. Significant differences in autolytic behavior and in biofilm development in glucose or sucrose were also observed. Natural genetic competence varied among isolates, and this was correlated to the presence or absence of competence genes, comCDE and comX, and to bacteriocins. In general strains that lacked the ability to become competent possessed fewer genes for bacteriocins and immunity proteins or contained polymorphic variants of these genes. WGS sequence analysis of the pan-genome revealed, for the first time, components of a Type VII secretion system in several S. mutans strains, as well as two putative ORFs that encode possible collagen binding proteins located upstream of the cnm gene, which is associated with host cell invasiveness. The virulence of these particular strains was assessed in a wax-worm model. This is the first study to combine a comprehensive analysis of key virulence-related phenotypes with extensive genomic analysis of a pathogen that evolved closely with humans. Our analysis highlights the phenotypic diversity of S. mutans isolates and indicates that the species has evolved a variety of adaptive strategies to persist in the human oral cavity and, when conditions are favorable, to initiate disease.

  11. Phenotypic Heterogeneity of Genomically-Diverse Isolates of Streptococcus mutans

    Science.gov (United States)

    Palmer, Sara R.; Miller, James H.; Abranches, Jacqueline; Zeng, Lin; Lefebure, Tristan; Richards, Vincent P.; Lemos, José A.; Stanhope, Michael J.; Burne, Robert A.

    2013-01-01

    High coverage, whole genome shotgun (WGS) sequencing of 57 geographically- and genetically-diverse isolates of Streptococcus mutans from individuals of known dental caries status was recently completed. Of the 57 sequenced strains, fifteen isolates, were selected based primarily on differences in gene content and phenotypic characteristics known to affect virulence and compared with the reference strain UA159. A high degree of variability in these properties was observed between strains, with a broad spectrum of sensitivities to low pH, oxidative stress (air and paraquat) and exposure to competence stimulating peptide (CSP). Significant differences in autolytic behavior and in biofilm development in glucose or sucrose were also observed. Natural genetic competence varied among isolates, and this was correlated to the presence or absence of competence genes, comCDE and comX, and to bacteriocins. In general strains that lacked the ability to become competent possessed fewer genes for bacteriocins and immunity proteins or contained polymorphic variants of these genes. WGS sequence analysis of the pan-genome revealed, for the first time, components of a Type VII secretion system in several S. mutans strains, as well as two putative ORFs that encode possible collagen binding proteins located upstream of the cnm gene, which is associated with host cell invasiveness. The virulence of these particular strains was assessed in a wax-worm model. This is the first study to combine a comprehensive analysis of key virulence-related phenotypes with extensive genomic analysis of a pathogen that evolved closely with humans. Our analysis highlights the phenotypic diversity of S. mutans isolates and indicates that the species has evolved a variety of adaptive strategies to persist in the human oral cavity and, when conditions are favorable, to initiate disease. PMID:23613838

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

    Science.gov (United States)

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

    2014-11-01

    Two strains were isolated from oral cavity samples of healthy elephants. The isolates were Gram-positive, catalase-negative, coccus-shaped organisms that were tentatively identified as a streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequence analysis suggested classification of these organisms in the genus Streptococcus with Streptococcus criceti ATCC 19642(T) and Streptococcus orisuis NUM 1001(T) as their closest phylogenetic neighbours with 98.2 and 96.9% gene sequence similarity, respectively. When multi-locus sequence analysis using four housekeeping genes, groEL, rpoB, gyrB and sodA, was carried out, similarity of concatenated sequences of the four housekeeping genes from the new isolates and Streptococcus mutans was 89.7%. DNA-DNA hybridization experiments suggested that the new isolates were distinct from S. criceti and other species of the genus Streptococcus. On the basis of genotypic and phenotypic differences, it is proposed that the novel isolates are classified in the genus Streptococcus as representatives of Streptococcus oriloxodontae sp. nov. The type strain of S. oriloxodontae is NUM 2101(T) ( =JCM 19285(T) =DSM 27377(T)). © 2014 IUMS.

  13. Streptococcus ovuberis sp. nov., isolated from a subcutaneous abscess in the udder of a sheep.

    Science.gov (United States)

    Zamora, Leydis; Pérez-Sancho, Marta; Fernández-Garayzábal, Jose Francisco; Orden, Jose Antonio; Domínguez-Bernal, Gustavo; de la Fuente, Ricardo; Domínguez, Lucas; Vela, Ana Isabel

    2017-11-01

    One unidentified, Gram-stain-positive, catalase-negative coccus-shaped organism was recovered from a subcutaneous abscess of the udder of a sheep and subjected to a polyphasic taxonomic analysis. Based on cellular morphology and biochemical criteria, the isolate was tentatively assigned to the genus Streptococcus, although the organism did not appear to match any recognized species. 16S rRNA gene sequence comparison studies confirmed its identification as a member of the genus Streptococcus and showed that the nearest phylogenetic relatives of the unknown coccus corresponded to Streptococcus moroccensis and Streptococcus cameli (95.9 % 16S rRNA gene sequence similarity). The sodA sequence analysis showed less than 89.3 % sequence similarity with the currently recognized species of the genus Streptococcus. The novel bacterial isolate was distinguished from close relatives of the genus Streptococcusby using biochemical tests. A mass spectrometry profile was also obtained for the novel isolate using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Based on both phenotypic and phylogenetic findings, it is proposed that the unknown bacterium be classified as a representative of a novel species of the genus Streptococcus, Streptococcus ovuberis sp. nov. The type strain of Streptococcus ovuberissp. nov. is VB15-00779 T (=CECT 9179 T =CCUG 69612 T ).

  14. Isolation and partial characterization of a biosurfactant produced by Streptococcus thermophilus A

    NARCIS (Netherlands)

    Rodrigues, Ligia R.; Teixeira, Jose A.; van der Mei, Henny C.; Oliveira, Rosario

    2006-01-01

    Isolation and characterization of the surface active components from the crude biosurfactant produced by Streptococcus thermophilus A was studied. A fraction rich in glycolipids was obtained by the fractionation of crude biosurfactant using hydrophobic interaction chromatography. Molecular (by

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

    Science.gov (United States)

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

    2016-10-01

    Nucleic acid amplification tests (NAATs) have frequently been the standard diagnostic approach when specific infectious agents are sought in a clinic specimen. They can be applied for specific agents such as S. pyogenes, or commercial multiplex NAATs for detection of a variety of pathogens in gastrointestinal, bloodstream, and respiratory infections may be used. NAATs are both rapid and sensitive. For many years, S. pyogenes testing algorithms used a rapid and specific group A streptococcal antigen test to screen throat specimens, followed, in some clinical settings, by a throat culture for S. pyogenes to increase the sensitivity of its detection. Now S. pyogenes NAATs are being used with increasing frequency. Given their accuracy, rapidity, and ease of use, should they replace antigen detection and culture for the detection of bacterial pharyngitis? Bobbi Pritt and Robin Patel of the Mayo Clinic, where S. pyogenes NAATs have been used for well over a decade with great success, will explain the advantages of this approach, while Richard (Tom) Thomson and Tom Kirn of the NorthShore University HealthSystem will discuss their concerns about this approach to diagnosing bacterial pharyngitis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  16. Chemoprophylaxis against Group A Streptococcus during Military Training

    Science.gov (United States)

    2018-12-14

    chemoprophylaxis policy, the highlights of which are presented in this paper. 28 29 Group A Streptococcus 30 Streptococcus pyogenes (or GAS) is a Gram-positive...236 6, 2017. 237 20. Gray GC, Escamilla J, Hyams KC, Struewing JP, Kaplan EL, Tupponce AK. Hyperendemic 238 Streptococcus pyogenes infection...Pharyngeal colonization prevalence rates 261 for Streptococcus pyogenes and Steptococcus pneumoniae in a respiratory chemoprophylaxis 262 intervention

  17. M-protein gene-type distribution and hyaluronic acid capsule in group A Streptococcus clinical isolates in Chile: association of emm gene markers with csrR alleles.

    Science.gov (United States)

    Wozniak, A; Rojas, P; Rodríguez, C; Undabarrena, A; Garate, C; Riedel, I; Román, J C; Kalergis, A M; García, P

    2012-07-01

    Streptococcus pyogenes causes a variety of infections because of virulence factors such as capsular hyaluronic acid and M protein. The aim of this study was to determine emm types and capsule phenotype in 110 isolates of S. pyogenes from patients with invasive (sterile sites) and non-invasive (mainly pharyngitis) infections in Chile, and the relationship between both virulence factors. The most abundant types found were emm12, emm1, emm4 and emm28 and their distribution was similar to that seen in Latin America and developed countries, but very different from that in Asia and Pacific Island countries. Ten of 16 emm types identified in pharyngeal isolates were found in sterile-site isolates, and three of nine emm types of sterile-site isolates occurred in pharyngeal isolates; three emm subtypes were novel. The amount of hyaluronic acid was significantly higher in sterile-site isolates but did not differ substantially among emm types. Only three isolates were markedly capsulate and two of them had mutations in the csrR gene that codes for a repressor of capsule synthesis genes. We found a non-random association between emm types and csrR gene alleles suggesting that horizontal gene transfer is not freely occurring in the population.

  18. Complement inhibition by Sarcoptes scabiei protects Streptococcus pyogenes - An in vitro study to unravel the molecular mechanisms behind the poorly understood predilection of S. pyogenes to infect mite-induced skin lesions.

    Science.gov (United States)

    Swe, Pearl M; Christian, Lindsay D; Lu, Hieng C; Sriprakash, Kadaba S; Fischer, Katja

    2017-03-01

    On a global scale scabies is one of the most common dermatological conditions, imposing a considerable economic burden on individuals, communities and health systems. There is substantial epidemiological evidence that in tropical regions scabies is often causing pyoderma and subsequently serious illness due to invasion by opportunistic bacteria. The health burden due to complicated scabies causing cellulitis, bacteraemia and sepsis, heart and kidney diseases in resource-poor communities is extreme. Co-infections of group A streptococcus (GAS) and scabies mites is a common phenomenon in the tropics. Both pathogens produce multiple complement inhibitors to overcome the host innate defence. We investigated the relative role of classical (CP), lectin (LP) and alternative pathways (AP) towards a pyodermic GAS isolate 88/30 in the presence of a scabies mite complement inhibitor, SMSB4. Opsonophagocytosis assays in fresh blood showed baseline immunity towards GAS. The role of innate immunity was investigated by deposition of the first complement components of each pathway, specifically C1q, FB and MBL from normal human serum on GAS. C1q deposition was the highest followed by FB deposition while MBL deposition was undetectable, suggesting that CP and AP may be mainly activated by GAS. We confirmed this result using sera depleted of either C1q or FB, and serum deficient in MBL. Recombinant SMSB4 was produced and purified from Pichia pastoris. SMSB4 reduced the baseline immunity against GAS by decreasing the formation of CP- and AP-C3 convertases, subsequently affecting opsonisation and the release of anaphylatoxin. Our results indicate that the complement-inhibitory function of SMSB4 promotes the survival of GAS in vitro and inferably in the microenvironment of the mite-infested skin. Understanding the tripartite interactions between host, parasite and microbial pathogens at a molecular level may serve as a basis to develop improved intervention strategies targeting scabies

  19. Peritonitis primaria por Streptococcus pyogenes

    OpenAIRE

    Munrós, Jordina; Alonso Vargas, María Inmaculada; Pino Saladrigues, Marta del; Pahisa Fábregas, Jaume; Almela, M. (Manel); Mensa Pueyo, Josep; Carmona Herrera, Francisco

    2014-01-01

    Sr. Editor: la peritonitis de origen infeccioso habitualmente es secundaria a procesos patológicos del tracto gastrointestinal o genitourinario y suele ser polimicrobiana. Se denomina peritonitis primaria o espontánea aquélla en la que no se objetiva ninguna causa evidente. Generalmente es de etiología monomicrobiana y se observa en pacientes afectos de cirrosis hepática, síndrome nefrótico o inmunosupresión. Su hallazgo en personas sin ninguna comorbilidad es muy poco frecuente. Los microorg...

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

    Science.gov (United States)

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

    2016-01-01

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

  1. STREPTOCOCCUS PHOCAE ISOLATED FROM A SPOTTED SEAL (PHOCA LARGHA) WITH PYOMETRA IN ALASKA

    Science.gov (United States)

    Hueffer, Karsten; Lieske, Camilla L.; McGilvary, Lisa M.; Hare, Rebekah F.; Miller, Debra L.; O’Hara, Todd M.

    2013-01-01

    A spotted seal harvested by subsistence hunters in Kotzebue Sound, Alaska (USA), showed a grossly enlarged uterus and associated lymph nodes. Streptococcus phocae was isolated from the purulent uterine discharge. Histopathologic examination revealed inflammation that was limited to the uterine mucosa. Lymph nodes draining the affected organ were reactive but no evidence of active infection was found in the lymph nodes. This report is the first Streptococcus phocae isolated from spotted seals as well as the first report of pyometra as the main pathologic finding associated with this pathogen. Isolation of this pathogen from Alaska expands the reported range to arctic pinnipeds. Zoonotic potential remains unknown. PMID:22946378

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

    Science.gov (United States)

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

    2016-01-01

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

  3. Occurrence of Streptococcus milleri among beta-hemolytic streptococci isolated from clinical specimens.

    Science.gov (United States)

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

    1985-01-01

    A total of 256 beta-hemolytic streptococcal isolates were subjected to serological and physiological tests to identify those which could be classified as Streptococcus milleri. S. milleri accounted for 75% of 70 group C isolates, 15% of 69 group G isolates, 75% of 16 nongroupable isolates, and 100% of 20 group F isolates examined. No S. milleri isolates were encountered among the 90 group A streptococci studied. Of the 95 beta-hemolytic S. milleri isolates examined, 81% were recovered from respiratory specimens. PMID:4031029

  4. Comparative pathogenomic characterization of a non-invasive serotype M71 strain Streptococcus pyogenes NS53 reveals incongruent phenotypic implications from distinct genotypic markers.

    Science.gov (United States)

    Bao, Yun-Juan; Li, Yang; Liang, Zhong; Agrahari, Garima; Lee, Shaun W; Ploplis, Victoria A; Castellino, Francis J

    2017-07-31

    The strains serotyped as M71 from group A Streptococcus are common causes of pharyngeal and skin diseases worldwide. Here we characterize the genome of a unique non-invasive M71 human isolate, NS53. The genome does not contain structural rearrangements or large-scale gene gains/losses, but encodes a full set of non-truncated known virulence factors, thus providing an ideal reference for comparative studies. However, the NS53 genome showed incongruent phenotypic implications from distinct genotypic markers. NS53 is characterized as an emm pattern D and FCT (fibronectin-collagen-T antigen) type-3 strain, typical of skin tropic strains, but is phylogenetically close to emm pattern E strains with preference for both skin and pharyngeal infections. We propose that this incongruence could result from recombination within the emm gene locus, or, alternatively, selection has been against those genetic alterations. Combined with the inability to select for CovS switching, a process is indicated whereby NS53 has been pre-adapted to specific host niches selecting against variations in CovS and many other genes. This may allow the strain to attain successful colonization and long-term survival. A balance between genetic variations and fitness may exist for this bacterium to form a stabilized genome optimized for survival in specific host environments. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Science.gov (United States)

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

    2016-03-01

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

  6. Streptococcus rupicaprae sp. nov., isolated from a Pyrenean chamois (Rupicapra pyrenaica).

    Science.gov (United States)

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

    2011-08-01

    Biochemical and molecular genetic studies were performed on an unknown Gram-stain-positive, catalase-negative, coccus-shaped organism isolated from clinical samples of a Pyrenean chamois. The micro-organism was identified as a streptococcal species based on its cellular morphological and biochemical tests. 16S rRNA gene sequence comparison studies confirmed its identification as a member of the genus Streptococcus, but the organism did not correspond to any species of this genus. The nearest phylogenetic relative of the unknown coccus from chamois was Streptococcus ovis (95.9 % 16S rRNA gene sequence similarity). The rpoB and sodA sequence analysis showed sequence similarity values of less than 85.7 % and 83.0 %, respectively, with the currently recognized species of the genus Streptococcus. The novel bacterial isolate was distinguished from S. ovis and other species of the genus Streptococcus using biochemical tests. Based on both phenotypic and phylogenetic findings, it is proposed that the unknown bacterium be classified as a novel species of the genus Streptococcus, Streptococcus rupicaprae sp. nov., with the type strain 2777-2-07(T) ( = CECT 7718(T)  = CCUG 59652(T)).

  7. Rate of isolation of streptococcus species from children with ...

    African Journals Online (AJOL)

    Background: Streptococcus species are among the commonest bacterial causes of childhood morbidity in developing countries. Streptococcal diseases in children have not been as well characterized in Nigeria as it has been in industrialized countries. The rudimentary nature of public health surveillance makes the true ...

  8. Streptococcus himalayensis sp. nov., isolated from the respiratory tract of Marmota himalayana.

    Science.gov (United States)

    Niu, Lina; Lu, Shan; Lai, Xin-He; Hu, Shoukui; Chen, Cuixia; Zhang, Gui; Yang, Jing; Jin, Dong; Wang, Yi; Lan, Ruiting; Lu, Gang; Xie, Yingping; Ye, Changyun; Xu, Jianguo

    2017-02-01

    Five strains of Gram-positive-staining, catalase-negative, coccus-shaped, chain-forming organisms isolated separately from the respiratory tracts of five Marmota himalayana animals in the Qinghai-Tibet Plateau of China were subjected to phenotypic and molecular taxonomic analyses. Comparative analysis of the 16S rRNA gene indicated that these singular organisms represent a new member of the genus Streptococcus, being phylogenetically closest to Streptococcus marmotae DSM 101995T (98.4 % similarity). The groEL, sodA and rpoB sequence analysis showed interspecies similarity values between HTS2T and Streptococcus. marmotae DSM 101995T, its closest phylogenetic relative based on 16S rRNA gene sequences, of 98.2, 78.8 and 93.7 %, respectively. A whole-genome phylogenetic tree built from 82 core genes of genomes from 16 species of the genus Streptococcus validated that HTS2T forms a distinct subline and exhibits specific phylogenetic affinity with S. marmotae. In silico DNA-DNA hybridization of HTS2T showed an estimated DNA reassociation value of 40.5 % with Streptococcus. marmotae DSM 101995T. On the basis of their phenotypic characteristics and phylogenetic findings, it is proposed that the five isolates be classified as representatives of a novel species of the genus Streptococcus, Streptococcus himalayensis sp. nov. The type strain is HTS2T (=DSM 101997T=CGMCC 1.15533T). The genome of Streptococcus himalayensis sp. nov. strain HTS2T contains 2195 genes with a size of 2 275 471 bp and a mean DNA G+C content of 41.3 mol%.

  9. Streptococcus pharyngis sp. nov., a novel streptococcal species isolated from the respiratory tract of wild rabbits.

    Science.gov (United States)

    Vela, Ana I; Casas-Díaz, Encarna; Lavín, Santiago; Domínguez, Lucas; Fernández-Garayzábal, Jose F

    2015-09-01

    Four isolates of an unknown Gram-stain-positive, catalase-negative coccus-shaped organism, isolated from the pharynx of four wild rabbits, were characterized by phenotypic and molecular genetic methods. The micro-organisms were tentatively assigned to the genus Streptococcus based on cellular morphological and biochemical criteria, although the organisms did not appear to correspond to any species with a validly published name. Comparative 16S rRNA gene sequencing confirmed their identification as members of the genus Streptococcus, being most closely related phylogenetically to Streptococcus porcorum 682-03(T) (96.9% 16S rRNA gene sequence similarity). Analysis of rpoB and sodA gene sequences showed divergence values between the novel species and S. porcorum 682-03(T) (the closest phylogenetic relative determined from 16S rRNA gene sequences) of 18.1 and 23.9%, respectively. The novel bacterial isolate could be distinguished from the type strain of S. porcorum by several biochemical characteristics, such as the production of glycyl-tryptophan arylamidase and α-chymotrypsin, and the non-acidification of different sugars. Based on both phenotypic and phylogenetic findings, it is proposed that the unknown bacterium be assigned to a novel species of the genus Streptococcus, and named Streptococcus pharyngis sp. nov. The type strain is DICM10-00796B(T) ( = CECT 8754(T) = CCUG 66496(T)).

  10. Isolated Native Tricuspid Valve Endocarditis Caused by Viridans Streptococcus

    Directory of Open Access Journals (Sweden)

    John Swiston

    2001-01-01

    Full Text Available The present report describes a case of native tricuspid valve endocarditis caused by viridans group streptococcus in a 43-year-old man who had recently undergone dental extraction. The patient had no history of intravenous drug use, heart disease or right heart catheterization. Although there have been scattered reports of unusual organisms, to the authors' knowledge, this is the first case of viridans group streptococcal endocarditis involving only the tricuspid valve after dental manipulation.

  11. Isolated native tricuspid valve endocarditis caused by viridans streptococcus

    OpenAIRE

    Swiston, John; Shafran, Stephen D; Kassam, Narmin

    2001-01-01

    The present report describes a case of native tricuspid valve endocarditis caused by viridans group streptococcus in a 43-year-old man who had recently undergone dental extraction. The patient had no history of intravenous drug use, heart disease or right heart catheterization. Although there have been scattered reports of unusual organisms, to the authors' knowledge, this is the first case of viridans group streptococcal endocarditis involving only the tricuspid valve after dental manipulation.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  13. Functional Predominance of msr(D), Which Is More Effective as mef(A)-Associated Than mef(E)-Associated, Over mef(A)/mef(E) in Macrolide Resistance in Streptococcus pyogenes.

    Science.gov (United States)

    Tatsuno, Ichiro; Isaka, Masanori; Masuno, Katsuaki; Hata, Nanako; Matsumoto, Masakado; Hasegawa, Tadao

    2018-02-06

    Although mef(A) and its subclass mef(E) genes have long been considered to play a central role in macrolide efflux-based resistance, we have previously demonstrated that the msr(D) gene located immediately downstream of the mef(A) gene plays a predominant role in Streptococcus pyogenes macrolide resistance. The mef(A) and mef(E) genes are carried by different genetic elements and the resistance associated with mef(A) was reported to be higher than that associated with mef(E); therefore, we further investigated the functional relevance of mef(A)/mef(E) and its associated msr(D). We established additional mef(A)-, mef(E)-, and their associated msr(D)-knockout strains and confirmed the predominance of msr(D) over mef(A)/mef(E). In addition, we performed experiments introducing mef(A), mef(E), and their associated msr(D) genes into mef(A)/mef(E)-msr(D) double-knockout and mef(A)/mef(E) negative strains. Neither mef(A) nor mef(E) genes had effects on erythromycin resistance. However, both associated msr(D) showed significant effects, and the mef(A)-associated msr(D) exhibited more effect than the mef(E)-associated one. These results suggest that an overall functional predominance of msr(D) over mef(A)/mef(E) is conceivable in efflux-based macrolide resistance in at least some S. pyogenes strains. Furthermore, the higher resistance of mef(A) system over mef(E) system could be derived at least in part from functional differences of mef(A)- and mef(E)-associated msr(D).

  14. Improved method for rapid and accurate isolation and identification of Streptococcus mutans and Streptococcus sobrinus from human plaque samples.

    Science.gov (United States)

    Villhauer, Alissa L; Lynch, David J; Drake, David R

    2017-08-01

    Mutans streptococci (MS), specifically Streptococcus mutans (SM) and Streptococcus sobrinus (SS), are bacterial species frequently targeted for investigation due to their role in the etiology of dental caries. Differentiation of S. mutans and S. sobrinus is an essential part of exploring the role of these organisms in disease progression and the impact of the presence of either/both on a subject's caries experience. Of vital importance to the study of these organisms is an identification protocol that allows us to distinguish between the two species in an easy, accurate, and timely manner. While conducting a 5-year birth cohort study in a Northern Plains American Indian tribe, the need for a more rapid procedure for isolating and identifying high volumes of MS was recognized. We report here on the development of an accurate and rapid method for MS identification. Accuracy, ease of use, and material and time requirements for morphological differentiation on selective agar, biochemical tests, and various combinations of PCR primers were compared. The final protocol included preliminary identification based on colony morphology followed by PCR confirmation of species identification using primers targeting regions of the glucosyltransferase (gtf) genes of SM and SS. This method of isolation and identification was found to be highly accurate, more rapid than the previous methodology used, and easily learned. It resulted in more efficient use of both time and material resources. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Conjugative transfer of R-plasmids from Streptococcus faecalis to Staphylococcus aureus.

    OpenAIRE

    Schaberg, D R; Clewell, D B; Glatzer, L

    1982-01-01

    R-plasmids originally isolated from Streptococcus pyogenes(pAC1,pAM15346), Streptococcus agalactiae(pIP501), and Streptococcus faecalis(pAM beta 1) were shown to be self-transferable on filter membranes from S. faecalis JH2-2 to Staphylococcus aureus recipients. The nonconjugative plasmid pAM alpha 1 was mobilized into S. aureus by pAM beta 1. Once in S. aureus, conjugative R-plasmids could be transferred to a second S. aureus recipient or back into S. faecalis. Determinants for chloramphenic...

  16. Antibacterial activity of Iranian medicinal plants against Streptococcus iniae isolated from rainbow trout (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Pirbalouti Ghasemi Abdollah

    2011-01-01

    Full Text Available Streptococcus iniae is among the major pathogens of a large number of fish species cultured in fresh and marine recirculating and net pen production systems. Ten Iranian medicinal plants were assessed for their antimicrobial activity against Streptococcus iniae isolates obtained from diseased Oncorhynchus mykiss (Salmonidae; Walbaum, 1972 collected from fish farms in Iran. The antibacterial activity of ethanol extracts of Punica granatum, Quercus branti, Glycyrrhiza glabra and essential oils of Heracleum lasiopetalum, Satureja bachtiarica, Thymus daenensis, Myrtus communis, Echinophora platyloba, Kelussia odoratissima and Stachys lavandulifolia against Steptococcus iniae was evaluated by disc diffusion and serial dilution assays. Most of the extracts and essential oils showed a relatively high antibacterial activity against Streptococcus iniae. Of the plants studied, the most active extracts were those obtained from the essential oils of Satureja bachtiarica, Echinophora platyloba, Thymus daenensis and the ethanol extract of Quercus branti. Some of the extracts were active against Streptococcus iniae. Two essential oils showed lower MIC values; Heracleum lasiopetalum (78 μg/ml and Satureja bachtiarica (39 μg/ml. The essential oil of Satureja bachtiarica could be an important source of antibacterial compounds against the Streptococcus iniae isolated from rainbow trout.

  17. Competence without a competence pheromone in a natural isolate of Streptococcus infantis

    DEFF Research Database (Denmark)

    Ween, O; Teigen, S; Gaustad, P

    2002-01-01

    C and a two-component regulatory system encoded by comDE. Here we report that a natural isolate of a mitis group streptococcus (Atu-4) is competent for genetic transformation even though it has lost the gene encoding the competence pheromone. In contrast to other strains, induction of competence in Atu-4...

  18. Expression of the major heat shock proteins DnaK and GroEL in Streptococcus pyogenes: a comparison to Enterococcus faecalis and Staphylococcus aureus.

    Science.gov (United States)

    Laport, M S; de Castro, A C; Villardo, A; Lemos, J A; Bastos, M C; Giambiagi-deMarval, M

    2001-04-01

    One of the outstanding problems in the field of heat shock response has been to elucidate the mechanism underlying the induction of heat shock proteins (HSPs). In this work, we initiate an analysis of the expression of heat shock groEL and dnaK genes and their promoters in S. pyogenes. The synthesis of total cellular proteins was studied upon transfer of a log-phase culture from 37 degrees C to 42 degrees C by performing 5-min pulse-labeling experiments with (35)S-Met. The heat shock responses in the pathogenic Gram-positive cocci, Enterococcus faecalis and Staphylococcus aureus, were also analyzed.

  19. In vitro antimicrobial susceptibility of Mycoplasma mycoides mycoides large colony and Arcanobacterium pyogenes isolated from clinical cases of ulcerative balanitis and vulvitis in Dorper sheep in South Africa

    Directory of Open Access Journals (Sweden)

    A. Kidanemariam

    2005-06-01

    Full Text Available The in vitro activities of enrofloxacin, florfenicol, oxytetracycline and spiramycin were determined against field isolates of Mycoplasma mycoides mycoides large colony (MmmLC by means of the broth microdilution technique. The minimum inhibitory concentrations (MICs of these antimicrobial drugs were determined for a representative number of 10 isolates and 1 type strain. The susceptibility of Arcanobacterium pyogenes to enrofloxacin, oxytetracycline and tilmicosin was determined by means of an agar disk diffusion test. The MICs of enrofloxacin, florfenicol, oxytetracycline and spiramycin were within the ranges of 0.125-0.5, 1.0-2.0, 2.0-4.0 and 4.0-8.0 µg / m , respectively. This study has shown that resistance of MmmLC against enrofloxacin, florfenicol, oxytetracycline and spiramycin was negligible. All the field strains of A. pyogenes that were tested were susceptible to enrofloxacin, oxytetracycline and tilmicosin with mean inhibition zones of 30.6, 42.3 and 35.8mm, respectively. Although there is lack of data on in vivo efficacy and in vitro MIC or inhibition zone diameter breakpoints of these antimicrobial drugs for MmmLC, the MIC results indicate that these 4 classes of antimicrobial drugs should be effective in the treatment of ulcerative balanitis and vulvitis in sheep in South Africa.

  20. Heterogeneity of plasmids determining high-level resistance to gentamicin in clinical isolates of Streptococcus faecalis.

    OpenAIRE

    Zervos, M J; Mikesell, T S; Schaberg, D R

    1986-01-01

    Between November 1981 and October 1984, 48 of 3,458 clinical isolates of Streptococcus faecalis at the University of Michigan Hospital showed high-level (greater than 2,000 micrograms/ml) resistance to gentamicin, as well as to all other clinically available aminoglycosides. Thirteen percent of clinical isolates in the University of Michigan Hospital currently demonstrate this level of resistance. Transfer of resistance to a plasmid-free streptococcal recipient was observed in filter matings ...

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

    Science.gov (United States)

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

    2007-11-01

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

  2. Clinical Significance and Characterization of Streptococcus tigurinus Isolates in an Adult Population.

    Science.gov (United States)

    Bourassa, Lori; Clarridge, J E

    2015-11-01

    Streptococcus tigurinus is a newly described member of the Streptococcus mitis group. Due to the difficulty in distinguishing viridans group streptococci (VGS) by phenotype, analysis of 16S rRNA sequences is necessary for the accurate identification of most species. Through a laboratory policy of analyzing all clinically significant isolates from the VGS group by16S rRNA gene sequencing, we identified 14 S. tigurinus isolates from 11 patients. The Vitek 2 system most commonly gave an excellent rating to an incorrect identification (e.g., Streptococcus mitis), as did matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) (e.g., Streptococcus oralis). S. tigurinus strains were recovered from numerous body sites, including the blood, peritoneal fluid, bone, synovial fluid, a perianal abscess, and an arm wound. Retrospective chart review indicated that most isolates were clinically significant, with bacteremia (n = 5), soft tissue infections (n = 3) osteomyelitis (n = 2), infected joint prosthesis (n = 2), and peritonitis (n = 2) being the most common, thus expanding the spectrum of disease associated with S. tigurinus. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  3. Infection of human keratinocytes by Streptococcus dysgalactiae subspecies dysgalactiae isolated from milk of the bovine udder.

    Science.gov (United States)

    Roma-Rodrigues, Catarina; Alves-Barroco, Cynthia; Raposo, Luís R; Costa, Mafalda N; Fortunato, Elvira; Baptista, Pedro Viana; Fernandes, Alexandra R; Santos-Sanches, Ilda

    2016-04-01

    Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) are considered exclusive animal pathogens; however, a putative zoonotic upper limb cellulitis, a prosthetic joint infection and an infective endocarditis were described in humans. To unravel if bovine SDSD isolates are able to infect human cells, the adherence and internalization to human primary keratinocytes of two bovine SDSD strains isolated from milk collected from udder were analyzed. Bacterial adhesion assays and confocal microscopy indicate a high adherence and internalization of SDSD isolates to human cells, suggesting for the first time the ability of bovine isolates to infect human cells. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  4. Streptococcus oricebi sp. nov., isolated from the oral cavity of tufted capuchin.

    Science.gov (United States)

    Saito, M; Shinozaki-Kuwahara, N; Hirasawa, M; Takada, K

    2016-02-01

    A Gram-stain-positive, catalase-negative, coccus-shaped organism was isolated from the oral cavity of tufted capuchin (Cebus apella). Comparative 16S rRNA gene sequence analysis suggested classification of the organism within the genus Streptococcus. Strain M8T was related most closely to Streptococcus oralis ATCC 35037T (96.17 % similarity) followed by Streptococcus massiliensis CCUG 49690T (95.90 %) based on the 16S rRNA gene. Strain M8T was related most closely to S. massiliensis CCUG 49690T (86.58 %) based on the RNA polymerase β subunit-encoding gene (rpoB), and to Streptococcus tigurinus AZ_3aT (81.26 %) followed by S. massiliensis CCUG 49690T (80.45 %) based on the 60 kDa heat-shock protein gene (groEL). The phylogenetic trees of 16S rRNA, rpoB and groEL gene sequences showed that strain M8T was most closely related to S. massiliensis. Based on phenotypic characterization as well as 16S rRNA gene and housekeeping gene (rpoB and groEL) sequence data, a novel taxon, Streptococcus oricebi sp. nov. (type strain M8T = JCM 30719T = DSM 100101T), is proposed.

  5. Whole-Genome Sequence Analysis of Antimicrobial Resistance Genes in Streptococcus uberis and Streptococcus dysgalactiae Isolates from Canadian Dairy Herds

    Science.gov (United States)

    Vélez, Julián Reyes; Cameron, Marguerite; Rodríguez-Lecompte, Juan Carlos; Xia, Fangfang; Heider, Luke C.; Saab, Matthew; McClure, J. Trenton; Sánchez, Javier

    2017-01-01

    The objectives of this study are to determine the occurrence of antimicrobial resistance (AMR) genes using whole-genome sequence (WGS) of Streptococcus uberis (S. uberis) and Streptococcus dysgalactiae (S. dysgalactiae) isolates, recovered from dairy cows in the Canadian Maritime Provinces. A secondary objective included the exploration of the association between phenotypic AMR and the genomic characteristics (genome size, guanine–cytosine content, and occurrence of unique gene sequences). Initially, 91 isolates were sequenced, and of these isolates, 89 were assembled. Furthermore, 16 isolates were excluded due to larger than expected genomic sizes (>2.3 bp × 1,000 bp). In the final analysis, 73 were used with complete WGS and minimum inhibitory concentration records, which were part of the previous phenotypic AMR study, representing 18 dairy herds from the Maritime region of Canada (1). A total of 23 unique AMR gene sequences were found in the bacterial genomes, with a mean number of 8.1 (minimum: 5; maximum: 13) per genome. Overall, there were 10 AMR genes [ANT(6), TEM-127, TEM-163, TEM-89, TEM-95, Linb, Lnub, Ermb, Ermc, and TetS] present only in S. uberis genomes and 2 genes unique (EF-TU and TEM-71) to the S. dysgalactiae genomes; 11 AMR genes [APH(3′), TEM-1, TEM-136, TEM-157, TEM-47, TetM, bl2b, gyrA, parE, phoP, and rpoB] were found in both bacterial species. Two-way tabulations showed association between the phenotypic susceptibility to lincosamides and the presence of linB (P = 0.002) and lnuB (P genes and the between the presence of tetM (P = 0.015) and tetS (P = 0.064) genes and phenotypic resistance to tetracyclines only for the S. uberis isolates. The logistic model showed that the odds of resistance (to any of the phenotypically tested antimicrobials) was 4.35 times higher when there were >11 AMR genes present in the genome, compared with genes (P resistance was lower for S. dysgalactiae than S. uberis (P = 0

  6. [Antibiotics susceptibility of Streptococcus and Enterococcus: data of Onerba network].

    Science.gov (United States)

    Vachée, A; Varon, E; Jouy, E; Meunier, D

    2009-05-01

    This work was aimed to analyze trends in susceptibility to antibiotics among the main species of beta-hemolytic streptococci involved in community-acquired infections in human (Streptococcus pyogenes and Streptococcus agalactiae), or in animals (Streptococcus suis and Streptococcus uberis) and also among the main enterocci species, Enterococcus faecalis and Enterococcus faecium. Data were recorded since 1996 through the Onerba networks. S. pyogenes, as the other beta-hemolytic streptococci studied remained fully susceptible to beta-lactam antibiotics. However, susceptibility to macrolides is clearly decreasing in S. pyogenes. In 2002, only 62 to 65% of the strains according to the network considered, were susceptible to erythromycin. A similar trend was observed for S. agalactiae with only 75% of erythromycin susceptibility in 2002, and for both species isolated from animals S. suis and S. uberis, with respectively 35 and 76% of strains susceptible to erythromycin. In enterococci, susceptibility to beta-lactams remained stable between 2000 and 2004. Indeed, the susceptibility to aminopenicillins remained high in E. faecalis (about 98%), whereas the proportion of E. faecium isolates susceptible to these antibiotics were lower than 60%. From 1999 to 2004, various studies conducted in French hospitals showed that the vancomycin resistance among enterococci accounted for less than 2%. However, the recent emergence of glycopeptide resistant enterococci clusters in French hospitals is a matter of concern and emphasizes the need for an ongoing surveillance. Such trend in macrolide resistance among S. pyogenes or S. agalactiae should consequently lead to propose other alternatives in case of beta-lactam allergy, and for pharyngitis, to rethink the place of the culture for susceptibility testing.

  7. Characterization of Streptococcus suis serotype 7 isolates from diseased pigs in Denmark

    DEFF Research Database (Denmark)

    Tian, Y.; Aarestrup, Frank Møller; Lu, C.P.

    2004-01-01

    to erythromycin (41%), tetracycline (24%) and streptomycin (28%) was observed. Furthermore, almost all isolates (101) were resistant to sulphamethoxazol. Most isolates were susceptible to ceftiofur, chloramphenicol, florfenicol, penicillin, ciprofloxacin, trimethoprim and trimethoprim + sulphonamides. The tet......Isolates of Streptococcus suis serotype 7 from diseased pigs in Denmark were characterized by ribotyping, pulsed field gel electrophoresis (PFGE), MlC-determinations and detection of resistance genes. Forty-one different ribotype profiles were found among the 103 isolates and could be divided...... into two main clusters. No obvious relationship between ribotypes and the clinical origin of the isolates could be observed. Fifty-four isolates, including all 24 isolates belonging to the main ribotype profile were examined by PFGE and 50 different profiles were found. A high frequency of resistance...

  8. Resistance patterns of Streptococcus pneumoniae isolated from the ...

    African Journals Online (AJOL)

    Initial oxacillin screening for penicillin resistance revealed that 12 out of 36 isolates were clearly sensitive, but combined with the result of Etest, penicillin resistance was found to be 6.8%. Susceptibility testing by disc diffusion revealed that 80.5% of isolates were sensitive to ceftriaxone and 94.4% to chloramphenicol.

  9. Identification of Streptococcus canis Isolated from Milk of Dairy Cows with Subclinical Mastitis

    OpenAIRE

    Hassan, Abdulwahed Ahmed; Akineden, Ömer; Usleber, Ewald

    2005-01-01

    Streptococcus canis was isolated from 31 milk samples from 11 cows in a dairy herd (with 49 lactating cows) affected by subclinical mastitis in north Rhine-Westphalia, Germany. Thirty-one isolates from the infected udder quarters were further characterized for their phenotypic and molecular properties. Most isolates (83.9%) produced α-galactosidase, and all were negative for β-d-glucuronidase. Amplification of the 16S rRNA gene by the PCR method and digestion with the restriction enzymes RsaI...

  10. Antibiotic Therapy in Pyogenic Meningitis in Paediatric Patients

    International Nuclear Information System (INIS)

    Tajdin, F.; Rasheed, M.A.; Ashraf, M.; Khan, G.J.; Rasheed, H.; Ejaz, H.

    2013-01-01

    Objective: To isolate and identify the causative pathogen, antibiotic sensitivity testing and success rate of empirical antibiotic therapy in pyogenic meningitis. Study Design: Analytical study. Place and Duration of Study: The Children's Hospital and Institute of Child Health, Lahore, Pakistan, from March to July 2012. Methodology: The study was performed on 72 culture positive meningitis cases in children less than 15 years of age. This therapy was evaluated by monitoring the patient's clinical picture for 14 - 21 days. The collected data was analyzed by Chi-square test. Results: Seventeen different bacteria were isolated. The most commonly occurring bacteria were coagulase negative Staphylococci (25%), E. coli (12.5%), Klebsiella pneumoniae (8.3%), Streptococcus pneumoniae (8.3%) and Pseudomonas aeruginosa (8.3%). All the bacteria were sensitive to vancomycin (96.7%), meropenem (76.7%), amikacin (75%), ciprofloxacin (65.3%), chloramphenicol (46.5%), ceftazidime (44.2%), cefepime (41.9%), co-amoxiclav (38.0%), oxacillin (34.8%), cefotaxime (21.4%), penicillin (20.7%), ceftriaxone (18.6%), cefuroxime (14%) and ampicillin (6.9%). The combination of sulbactam and cefoperazone showed antimicrobial sensitivity of 81.4%. The success rate of empirical antibiotic therapy was 91.7%. Conclusion: It was found that Gram negative bacteria were the major cause of pyogenic meningitis. Mostly there were resistant strains against all commonly used antibiotics except vancomycin. All empirical antibiotic therapies were found to be most successful. (author)

  11. Antimicrobial susceptibility of Streptococcus suis isolated from clinically healthy swine in Brazil

    OpenAIRE

    Soares, Taíssa Cook Siqueira; Paes, Antonio Carlos; Megid, Jane; Ribolla, Paulo Eduardo Martins; Paduan, Karina dos Santos; Gottschalk, Marcelo

    2014-01-01

    Streptococcus suis is an important pathogen in the swine industry. This study is the first to report on the antimicrobial susceptibility of S. suis isolated from clinically healthy pigs in Brazil; the fourth major pork producer in the world. The antimicrobial susceptibility of 260 strains was determined by disc diffusion method. Strains were commonly susceptible to ceftiofur, cephalexin, chloramphenicol, and florfenicol, with more than 80% of the strains being susceptible to these antimicrobi...

  12. Occurrence, isolation and DNA identification of streptococcus thermophilus involved in algerian traditional butter 'Smen'

    OpenAIRE

    Labtar, Asmaa; Delorme, Christine; Renault, Pierre

    2011-01-01

    Streptococcus thermophilus isolates from traditional butter 'Smen', a fermented product from cow's and ewe's milk in arid area was subjected to taxonomical investigations. The identification procedure included phenotypic approaches, molecular characterization by using genus polymerase chain reaction (PCR) amplifications for sodA gene encoding the manganese-dependant superoxide dismutase A, and species-specific primers from gene encoding glucose kinase (glcK), gene encoding DNA polymerase III ...

  13. Streptococcus pneumoniae aislados de infecciones invasivas: serotipos y resistencia antimicrobiana Streptococcus pneumoniae isolated from invasive infections: serotypes and antimicrobial resistance

    Directory of Open Access Journals (Sweden)

    Gladys Antonia Cueto Montoya

    2007-03-01

    Full Text Available Las meningoencefalitis bacterianas constituyen una enfermedad invasiva importante, quizás no tanto por su frecuencia, como por la gravedad de su cuadro. Los cambios en la epidemiología de los síndromes neurológicos infecciosos en Cuba a partir de la vacunación contra meningococo BC y Haemophilus influenzae b han hecho que el Streptococcus pneumoniae constituya el agente causal más frecuente. Debido al incremento de la resistencia de este microorganismo a los antibióticos habituales, se realizaron modificaciones al régimen terapéutico convencional, fundamentalmente en las meningitis pediátricas. Es necesario lograr el aislamiento en cultivo de este agente para conocer los serotipos más frecuentes en el país, y lograr una vacuna neumocócica conjugada, así como para la vigilancia de las cepas frente a los antimicrobianos.The bacterial meningoencephalitis is an important invasive disease, not only because of its frequency, but also because of the severity of its picture. The changes in the epidemiology of the neurological infectious syndromes in Cuba starting from the vaccination against meningococcus BC and Haemophilus infuenzae b have made that Streptococcus pneumoniae be the most frequent causal agent. Due to the increase of the resistance of this microorganism to habitual antibiotics, modifications were made in the conventional therapeutic regimen, mainly in the pediatric meningitis. It is necessary to achieve the isolation in culture of this agent to know the most common serotypes in the country, to attain a conjugated pneumococcal vaccine, and to keep the surveillance of the strains against the antimicrobials.

  14. Pharmacodynamic analysis and clinical trial of amoxicillin sprinkle administered once daily for 7 days compared to penicillin V potassium administered four times daily for 10 days in the treatment of tonsillopharyngitis due to Streptococcus pyogenes in children.

    Science.gov (United States)

    Pichichero, M E; Casey, J R; Block, S L; Guttendorf, R; Flanner, H; Markowitz, D; Clausen, S

    2008-07-01

    An a priori pharmacokinetic/pharmacodynamic (PK/PD) target of 40% daily time above the MIC (T >MIC; based on the MIC(90) of 0.06 microg/ml for Streptococcus pyogenes reported in the literature) was shown to be achievable in a phase 1 study of 23 children with a once-daily (QD) modified-release, multiparticulate formulation of amoxicillin (amoxicillin sprinkle). The daily T >MIC achieved with the QD amoxicillin sprinkle formulation was comparable to that achieved with a four-times-daily (QID) penicillin VK suspension. An investigator-blinded, randomized, parallel-group, multicenter study involving 579 children 6 months to 12 years old with acute streptococcal tonsillopharyngitis was then undertaken. Children were randomly assigned 1:1 to receive either the amoxicillin sprinkle (475 mg for ages 6 months to 4 years, 775 mg for ages 5 to 12 years) QD for 7 days or 10 mg/kg of body weight of penicillin VK QID for 10 days (up to the maximum dose of 250 mg QID). Unexpectedly, the rates of bacteriological eradication at the test of cure were 65.3% (132/202) for the amoxicillin sprinkle and 68.0% (132/194) for penicillin VK (95% confidence interval, -12.0% to 6.6%). Thus, neither antibiotic regimen met the minimum criterion of > or =85% eradication ordinarily required by the U.S. FDA for first-line treatment of tonsillopharyngitis due to S. pyogenes. The results of subgroup analyses across demographic characteristics and current infection characteristics and by age/weight categories were consistent with the primary-efficacy result. The clinical cure rates for amoxicillin sprinkle and penicillin VK were 86.1% (216/251) and 91.9% (204/222), respectively (95% confidence interval, -11.6% to -0.4%). The results of a post hoc PD analysis suggested that a requirement for 60% daily T >MIC(90) more accurately predicted the observed high failure rates for bacteriologic eradication with the amoxicillin sprinkle and penicillin VK suspension studied. Based on the association between

  15. Pharmacodynamic Analysis and Clinical Trial of Amoxicillin Sprinkle Administered Once Daily for 7 Days Compared to Penicillin V Potassium Administered Four Times Daily for 10 Days in the Treatment of Tonsillopharyngitis Due to Streptococcus pyogenes in Children▿

    Science.gov (United States)

    Pichichero, M. E.; Casey, J. R.; Block, S. L.; Guttendorf, R.; Flanner, H.; Markowitz, D.; Clausen, S.

    2008-01-01

    An a priori pharmacokinetic/pharmacodynamic (PK/PD) target of 40% daily time above the MIC (T >MIC; based on the MIC90 of 0.06 μg/ml for Streptococcus pyogenes reported in the literature) was shown to be achievable in a phase 1 study of 23 children with a once-daily (QD) modified-release, multiparticulate formulation of amoxicillin (amoxicillin sprinkle). The daily T >MIC achieved with the QD amoxicillin sprinkle formulation was comparable to that achieved with a four-times-daily (QID) penicillin VK suspension. An investigator-blinded, randomized, parallel-group, multicenter study involving 579 children 6 months to 12 years old with acute streptococcal tonsillopharyngitis was then undertaken. Children were randomly assigned 1:1 to receive either the amoxicillin sprinkle (475 mg for ages 6 months to 4 years, 775 mg for ages 5 to 12 years) QD for 7 days or 10 mg/kg of body weight of penicillin VK QID for 10 days (up to the maximum dose of 250 mg QID). Unexpectedly, the rates of bacteriological eradication at the test of cure were 65.3% (132/202) for the amoxicillin sprinkle and 68.0% (132/194) for penicillin VK (95% confidence interval, −12.0% to 6.6%). Thus, neither antibiotic regimen met the minimum criterion of ≥85% eradication ordinarily required by the U.S. FDA for first-line treatment of tonsillopharyngitis due to S. pyogenes. The results of subgroup analyses across demographic characteristics and current infection characteristics and by age/weight categories were consistent with the primary-efficacy result. The clinical cure rates for amoxicillin sprinkle and penicillin VK were 86.1% (216/251) and 91.9% (204/222), respectively (95% confidence interval, −11.6% to −0.4%). The results of a post hoc PD analysis suggested that a requirement for 60% daily T >MIC90 more accurately predicted the observed high failure rates for bacteriologic eradication with the amoxicillin sprinkle and penicillin VK suspension studied. Based on the association between longer

  16. Isolation, characterization, virulence and immunogenicity testing of field isolates of Pasteurella multocida, Staphylococcus aureus, and Streptococcus agalactiae in laboratory settings.

    Science.gov (United States)

    Qudratullah; Muhammad, G; Saqib, M; Bilal, M Qamar

    2017-08-01

    The present study was designed to investigate isolation, characterization, virulence and immunogenicity testing of field isolates of Pasteurella multocida, Staphylococcus aureus, and Streptococcus agalactiae in rabbits and mice. Isolates of P. multocida, S. aureus and Str. agalactiae recovered from field cases of Hemorragic septicemia and mastitis were scrutinized for virulence/pathogenicity and immunogenicity. Mouse LD 50 of P. multocida showed that P. multocida isolate No.1 was more virulent than isolates No. 2 and 3. Virulence of isolate No.1S. aureus and Str. agalactiae revealed that 100, 80% rabbits died within 18h of inoculation. Seven-digit numerical profiles of these 4 isolates with API ® Staph test strips isolates, No.1 (6736153) showed good identification (S. aureus id=90.3%). Indirect ELISA-based serum antibody titers to P. multocida isolate No.1, S. aureus No.1, Str. agalactiae, isolate No.1 elicited high antibody titers 1.9, 1.23, 1.12 respectively. All the pathogens of Isolate No. 1 (P. multocida, S. aureus Str. agalactiae), were high antibody than others isolates. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Portadores assintomáticos de infecções por Streptococcus pyogenes em duas escolas públicas na cidade do Recife, Pernambuco

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    Maciel Amelia

    2003-01-01

    Full Text Available OBJETIVOS: investigar a prevalência Streptococus pyogenes em secreção de orofaringe de escolares procedentes de duas escolas públicas da cidade Recife. MÉTODOS: estudo epidemiológico e clínico-microbiológico descritivo no qual foram examinados 753 escolares. A cultura bacteriana da secreção orofaringeana foi realizada em ágar-sangue de carneiro 5% e as cepas SBGA identificadas através dos testes de bacitracina, Pyr e aglutinação em látex. RESULTADOS: a faixa etária dos 753 escolares analisados variou de cinco a 19 anos, sendo 54,3% do sexo masculino e 45,7% do sexo feminino. Seis eram portadores assintomáticos de SBGA e foram submetidos ao tratamento com penicilina. Após o tratamento, realizou-se a dosagem da antiestreptolisina o (ASLO, cujos títulos séricos foram inferiores a 200UT. CONCLUSÕES: uma prevalência de SBGA de 0,8% foi estimada em portadores assintomáticos, considerada baixa, quando comparado a outros resultados em estudos semelhantes. Os autores sugerem a realização de outros estudos para estimar a prevalência de SBGA em crianças com faringite e sua relação com a febre reumática aguda.

  18. Detection of staphylococcus aureus and streptococcus pyogenes in the personnel of the department of surgery and surgical rooms at the San Jose Universitary Hospital Popayan, Colombia

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    Liliana Caldas

    2010-03-01

    Full Text Available Objective: To detect Staphylococcus aureus and Streptococcus pyogenes in health personnel of the surgical and surgery services at Hospital San José. Methodology. Descriptive, Prospective cross-sectional study. The techniques used were surveys and sampling nasal and pharyngeal microbiological cultures. Results. It was found that from 29 persons under study, 10 (34.40yo were S. aureus carriers, and it was not found S. pyogenes carriers. From the positives, 8 (80% were S. aureus nasal carriers, and 2 (20% pharyngeal carriers. From 8 people (80%, 4 (40% belonged to the department ofsurgery and another 4 (40% to the surgical services; 2 (20% from the pharyngeal positives worked at the surgery services. From the carriers, 5 people (50% were nursing assistants, followed by 4 (40%, who belong to doctors and 1 person (10% belonged to nursing.

  19. Whole-Genome Sequence Analysis of Antimicrobial Resistance Genes in Streptococcus uberis and Streptococcus dysgalactiae Isolates from Canadian Dairy Herds

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    Julián Reyes Vélez

    2017-05-01

    Full Text Available The objectives of this study are to determine the occurrence of antimicrobial resistance (AMR genes using whole-genome sequence (WGS of Streptococcus uberis (S. uberis and Streptococcus dysgalactiae (S. dysgalactiae isolates, recovered from dairy cows in the Canadian Maritime Provinces. A secondary objective included the exploration of the association between phenotypic AMR and the genomic characteristics (genome size, guanine–cytosine content, and occurrence of unique gene sequences. Initially, 91 isolates were sequenced, and of these isolates, 89 were assembled. Furthermore, 16 isolates were excluded due to larger than expected genomic sizes (>2.3 bp × 1,000 bp. In the final analysis, 73 were used with complete WGS and minimum inhibitory concentration records, which were part of the previous phenotypic AMR study, representing 18 dairy herds from the Maritime region of Canada (1. A total of 23 unique AMR gene sequences were found in the bacterial genomes, with a mean number of 8.1 (minimum: 5; maximum: 13 per genome. Overall, there were 10 AMR genes [ANT(6, TEM-127, TEM-163, TEM-89, TEM-95, Linb, Lnub, Ermb, Ermc, and TetS] present only in S. uberis genomes and 2 genes unique (EF-TU and TEM-71 to the S. dysgalactiae genomes; 11 AMR genes [APH(3′, TEM-1, TEM-136, TEM-157, TEM-47, TetM, bl2b, gyrA, parE, phoP, and rpoB] were found in both bacterial species. Two-way tabulations showed association between the phenotypic susceptibility to lincosamides and the presence of linB (P = 0.002 and lnuB (P < 0.001 genes and the between the presence of tetM (P = 0.015 and tetS (P = 0.064 genes and phenotypic resistance to tetracyclines only for the S. uberis isolates. The logistic model showed that the odds of resistance (to any of the phenotypically tested antimicrobials was 4.35 times higher when there were >11 AMR genes present in the genome, compared with <7 AMR genes (P < 0.001. The odds of resistance was lower for S

  20. Purulent Pericarditis Caused by Group A Streptococcus

    OpenAIRE

    Bhaduri-McIntosh, Sumita; Prasad, Meeta; Moltedo, José; Vázquez, Marietta

    2006-01-01

    Purulent pericarditis is a rare disease that is most often caused by organisms such as Staphylococcus aureus, Streptococcus pneumoniae, viridans streptococci, Haemophilus influenzae, and anaerobic bacteria. We present an unusual case of purulent pericarditis caused by Streptococcus pyogenes, Lancefield group A streptococcus (GAS), and we provide a review of the literature.

  1. Streptococcus azizii sp. nov., isolated from naïve weanling mice.

    Science.gov (United States)

    Shewmaker, Patricia Lynn; Whitney, Anne M; Gulvik, Christopher A; Lipman, Neil S

    2017-12-01

    Three isolates of a previously reported novel catalase-negative, Gram-stain-positive, coccoid, alpha-haemolytic, Streptococcus species that were associated with meningoencephalitis in naïve weanling mice were further evaluated to confirm their taxonomic status and to determine additional phenotypic and molecular characteristics. Comparative 16S rRNA gene sequence analysis showed nearly identical intra-species sequence similarity (≥99.9 %), and revealed the closest phylogenetically related species, Streptococcus acidominimus and Streptococcuscuniculi, with 97.0 and 97.5 % sequence similarity, respectively. The rpoB, sodA and recN genes were identical for the three isolates and were 87.6, 85.7 and 82.5 % similar to S. acidominimus and 89.7, 86.2 and 80.7 % similar to S. cuniculi, respectively. In silico DNA-DNA hybridization analyses of mouse isolate 12-5202 T against S. acidominimus CCUG 27296 T and S. cuniculi CCUG 65085 T produced estimated values of 26.4 and 25.7 % relatedness, and the calculated average nucleotide identity values were 81.9 and 81.7, respectively. These data confirm the taxonomic status of 12-5202 T as a distinct Streptococcus species, and we formally propose the type strain, Streptococcusazizii 12-5202 T (=CCUG 69378 T =DSM 103678 T ). The genome of Streptococcus azizii sp. nov. 12-5202 T contains 2062 total genes with a size of 2.34 Mbp, and an average G+C content of 42.76 mol%.

  2. In silico assessment of virulence factors in strains of Streptococcus oralis and Streptococcus mitis isolated from patients with Infective Endocarditis

    DEFF Research Database (Denmark)

    Rasmussen, Louise H.; Iversen, Katrine Højholt; Dargis, Rimtas

    2017-01-01

    Streptococcus oralis and Streptococcus mitis belong to the Mitis group, which are mostly commensals in the human oral cavity. Even though S. oralis and S. mitis are oral commensals, they can be opportunistic pathogens causing infective endocarditis. A recent taxonomic re-evaluation of the Mitis...... group has embedded the species Streptococcus tigurinus and Streptococcus dentisani into the species S. oralis as subspecies. In this study, the distribution of virulence factors that contribute to bacterial immune evasion, colonization and adhesion was assessed in clinical strains of S. oralis (subsp...

  3. Comparative Genome Analyses of Streptococcus suis Isolates from Endocarditis Demonstrate Persistence of Dual Phenotypic Clones.

    Science.gov (United States)

    Tohya, Mari; Watanabe, Takayasu; Maruyama, Fumito; Arai, Sakura; Ota, Atsushi; Athey, Taryn B T; Fittipaldi, Nahuel; Nakagawa, Ichiro; Sekizaki, Tsutomu

    2016-01-01

    Many bacterial species coexist in the same niche as heterogeneous clones with different phenotypes; however, understanding of infectious diseases by polyphenotypic bacteria is still limited. In the present study, encapsulation in isolates of the porcine pathogen Streptococcus suis from persistent endocarditis lesions was examined. Coexistence of both encapsulated and unencapsulated S. suis isolates was found in 26 out of 59 endocarditis samples. The isolates were serotype 2, and belonged to two different sequence types (STs), ST1 and ST28. The genomes of each of the 26 pairs of encapsulated and unencapsulated isolates from the 26 samples were sequenced. The data showed that each pair of isolates had one or more unique nonsynonymous mutations in the cps gene, and the encapsulated and unencapsulated isolates from the same samples were closest to each other. Pairwise comparisons of the sequences of cps genes in 7 pairs of encapsulated and unencapsulated isolates identified insertion/deletions (indels) ranging from one to 104 bp in different cps genes of unencapsulated isolates. Capsule expression was restored in a subset of unencapsulated isolates by complementation in trans with cps expression vectors. Examination of gene content common to isolates indicated that mutation frequency was higher in ST28 pairs than in ST1 pairs. Genes within mobile genetic elements were mutation hot spots among ST28 isolates. Taken all together, our results demonstrate the coexistence of dual phenotype (encapsulated and unencapsulated) bacterial clones and suggest that the dual phenotypes arose independently in each farm by means of spontaneous mutations in cps genes.

  4. Streptococcus equi subsp. zooepidemicus isolates from equine infectious endometritis belong to a distinct genetic group.

    Science.gov (United States)

    Rasmussen, Camilla Dooleweerdt; Haugaard, Maria Mathilde; Petersen, Morten Roenn; Nielsen, Jesper Møller; Pedersen, Hanne Gervi; Bojesen, Anders Miki

    2013-04-18

    Streptococcus equi subsp. zooepidemicus is the pathogen most commonly isolated from the uterus of mares. S. zooepidemicus is an opportunistic pathogen and part of the resident flora in the caudal reproductive tract. The aim of this study was to investigate whether a genotypically distinct subpopulation of S. zooepidemicus is associated with endometritis in the mare, by genotyping and comparing uterine S. zooepidemicus strains with isolates from the vagina and clitoral fossa. Mares with (n=18) or without (n=11) clinical symptoms of endometritis were included. Uterine samples were obtained using a guarded endometrial biopsy punch, whereas a swab was used to recover samples from the cranial vagina and the clitoral fossa. If S. zooepidemicus was present, up to three colonies were selected from each anatomical location (max. 9 isolates per mare). Bacterial isolates were characterized by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). S. zooepidemicus was isolated from the endometrium of 12 mares. A total of 88 isolates were analyzed by PFGE: 31 from the endometrium, 26 from the cranial vagina and 31 isolates from the clitoral fossa. For MLST 21 isolates were chosen. Results demonstrated a higher genetic similarity of the isolates obtained from infectious endometritis compared to isolates obtained from the caudal reproductive tract. In conclusion, we demonstrate for the first time that a genetically distinct group of S. zooepidemicus is associated with infectious endometritis in the mare.

  5. Fluoroquinolone-nonsusceptible Streptococcus pneumoniae isolates from a medical center in the pneumococcal conjugate vaccine era

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    Hsin-Hang Chen

    2017-12-01

    Full Text Available Background/Purpose: Streptococcus pneumoniae is one of the most common pathogens to cause mucosal and invasive infection in humans. Resistance to fluoroquinolones (FQ is associated with clinical failure when treating pneumococcal diseases and increase of mortality. Methods: We collected clinical isolates of S. pneumoniae from January 2011 to July 2015 at Chang Gung Memorial Hospital, Taoyuan, Taiwan. Susceptibility to FQ was examined by disk diffusion method. Levofloxacin or moxifloxacin-nonsusceptible S. pneumoniae isolates were analyzed by serotyping, multilocus sequence typing, and sequencing of the quinolone resistance-determining regions (QRDRs of gyrA, gyrB, parC, and parE. Results: During the study period, 42 FQ-nonsusceptible pneumococcal isolates were identified. The rate increased from 1.6% of total pneumococcal isolates (2 of 127 in 2011 to 4.6% (13 of 283 in 2014, then decreased to 1.5% (3 of 202 in the first half of 2015. These isolates belonged to 13 serotypes, and serotype 14 (12 of 42, 33.3% was the most prevalent. Most of the isolates belonged to international clones or their variants. After QRDR analysis, there were 19 isolates in five clusters that shared both the same sequence type and QRDR mutation. Conclusions: FQ resistance initially emerged in either vaccine or nonvaccine serotypes. The majority of isolates were international clones or related variants, suggesting that resistance was disseminated through clonal spread. The wide use of pneumococcal conjugate vaccine since 2013 appears to have reduced the spread of FQ-nonsusceptible pneumococci. Keywords: Fluoroquinolone, resistance, Streptococcus pneumoniae, pneumococcal conjugate vaccine

  6. Serotype and Genotype Distribution among Invasive Streptococcus pneumoniae Isolates in Colombia, 2005–2010

    Science.gov (United States)

    Parra, Eliana L.; Ramos, Viviana; Sanabria, Olga; Moreno, Jaime

    2014-01-01

    In Colombia, a laboratory-based surveillance of invasive Streptococcus pneumoniae isolates as part of SIREVA II PAHO has been conducted since 1994. This study describes the serotype distribution, antimicrobial resistance, and genetic relationships of pneumococcal isolates recovered in Colombia from 2005 to 2010. In this study, demographic data of invasive S. pneumoniae isolates were analyzed, and antimicrobial susceptibility patterns were determined. Pulse field gel electrophoresis (n = 629) and multilocus sequence typing (n = 10) were used to determine genetic relationship of isolates with minimal inhibitory concentration to penicillin ≥0.125 µg/mL. A total of 1775 isolates of S. pneumoniae were obtained. Fifteen serotypes accounted for 80.7% of isolates. Serotype 14 (23.1%) was the most frequent in the general population. Penicillin resistance was 30.7% in meningitis and 9.0% in non-meningitis. Clones Spain6BST90, Spain9VST156, Spain23FST81, and Colombia23FST338 were associated to isolates. Additionally, serotype 6A isolates were associated with ST460 and ST473, and 19A isolates with ST276, ST320, and ST1118. In conclusion, the surveillance program provided updated information of trends in serotype distribution, antimicrobial resistance and the circulation of clones in invasive pneumococcal diseases. These results could be helpful to understand the epidemiology of S. pneumoniae in Colombia, and provide a baseline to measure the impact of vaccine introduction. PMID:24416330

  7. Streptococcus pneumoniae: estudo das cepas isoladas de liquor Streptococcus pneumoniae: a study of strains isolated from cerebrospinal fluid

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    Ataiza C. Vieira

    2007-02-01

    Full Text Available OBJETIVO: Determinar a freqüência dos sorotipos capsulares e a susceptibilidade antimicrobiana de cepas de Streptococcus pneumoniae, assim como dar suporte à indicação de vacinas disponíveis e ao uso de antimicrobianos. MÉTODOS: Neste estudo retrospectivo, foram adotadas metodologias padronizadas para identificar, sorotipar e determinar a susceptibilidade à penicilina, cefotaxima e vancomicina. O estudo foi realizado com cepas de pneumococo isoladas de liquor em pacientes atendidos nos hospitais públicos e em três hospitais particulares do Distrito Federal no período de janeiro de 1995 a dezembro de 2004. A identificação e a determinação de susceptibilidade a antimicrobianos foi realizada no Laboratório Central de Saúde Pública no Distrito Federal. A sorotipagem foi realizada no Instituto Adolfo Lutz. RESULTADOS: Foram isoladas 232 cepas de pneumococo, compreendendo 126 cepas (54,31% de pacientes do sexo masculino. A idade dos pacientes variou de 0 a 62 anos, sendo agrupados em faixas etárias de 0 a 5, 6 a 17, 18 a 50 e acima de 50 anos. Identificaram-se 36 sorotipos distintos. Desses destacaram-se oito: 14, 6B, 18C, 5, 19F, 23F, 9V e 6A. O teste de oxacilina caracterizou 67 cepas resistentes à penicilina; dessas, 47 foram confirmadas pelo E teste com resistência de nível intermediário. Nenhuma cepa apresentou resistência de alto nível. CONCLUSÃO: A resistência do pneumococo à penicilina apresentou um aumento gradativo nos últimos 10 anos no Distrito Federal. Os sorotipos mais isolados na faixa etária de 0 a 5 anos foram também os mais envolvidos na resistência à penicilina, e estão incluídos na vacina 7-valente.OBJECTIVE: To determine the frequency of capsular serotypes and the antimicrobial susceptibility of strains of Streptococcus pneumoniae, as well as to provide recommendations on the use of available vaccines and antimicrobial drugs. METHODS: In this retrospective study, standard procedures were followed

  8. Characterisation of Invasive Streptococcus pneumoniae Isolated from Cambodian Children between 2007 - 2012.

    Science.gov (United States)

    Moore, Catrin E; Giess, Adam; Soeng, Sona; Sar, Poda; Kumar, Varun; Nhoung, Pheakdey; Bousfield, Rachel; Turner, Paul; Stoesser, Nicole; Day, Nicholas P J; Parry, Christopher M

    2016-01-01

    The 13-valent pneumococcal vaccine (PCV13) was introduced in Cambodia in January 2015. There are limited data concerning the common serotypes causing invasive pneumococcal disease (IPD). Knowledge of the circulating pneumococcal serotypes is important to monitor epidemiological changes before and after vaccine implementation. All episodes of IPD defined by the isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or other sterile site in Cambodian children admitted to the Angkor Hospital for Children in Siem Reap, Northwestern Cambodia, between 1st January 2007 and 1st July 2012 were retrospectively studied. Streptococcus pneumoniae isolates that could be retrieved underwent phenotypic typing and whole genome sequencing. There were 90 Cambodian children hospitalized with IPD with a median (IQR) age of 2.3 years (0.9-6.2). The case fatality was 15.6% (95% CI 8-23). Of 50 Streptococcus pneumoniae isolates available for further testing, 46% were penicillin non-susceptible and 8% were ceftriaxone non-susceptible, 78% were cotrimoxazole resistant, 30% were erythromycin resistant and 30% chloramphenicol resistant. There were no significant changes in resistance levels over the five-year period. The most common serotypes were 1 (11/50; 22%), 23F (8/50; 16%), 14 (6/50; 12%), 5 (5/50; 10%) and 19A (3/50; 6%). Coverage by PCV7, PCV10 and PCV13 was 44%, 76% and 92% respectively. We identified novel multilocus sequence types and resistotypes using whole genome sequencing. This study suggests IPD is an important disease in Cambodian children and can have a significant mortality. PCV13 coverage of the serotypes determined in studied strains was high and consistent with another recent study. The phenotypic resistance patterns observed were similar to other regional studies. The use of whole genome sequencing in the present study provides additional typing and resistance information together with the description of novel sequence types and resistotypes.

  9. Characterisation of Invasive Streptococcus pneumoniae Isolated from Cambodian Children between 2007 - 2012.

    Directory of Open Access Journals (Sweden)

    Catrin E Moore

    Full Text Available The 13-valent pneumococcal vaccine (PCV13 was introduced in Cambodia in January 2015. There are limited data concerning the common serotypes causing invasive pneumococcal disease (IPD. Knowledge of the circulating pneumococcal serotypes is important to monitor epidemiological changes before and after vaccine implementation.All episodes of IPD defined by the isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or other sterile site in Cambodian children admitted to the Angkor Hospital for Children in Siem Reap, Northwestern Cambodia, between 1st January 2007 and 1st July 2012 were retrospectively studied. Streptococcus pneumoniae isolates that could be retrieved underwent phenotypic typing and whole genome sequencing.There were 90 Cambodian children hospitalized with IPD with a median (IQR age of 2.3 years (0.9-6.2. The case fatality was 15.6% (95% CI 8-23. Of 50 Streptococcus pneumoniae isolates available for further testing, 46% were penicillin non-susceptible and 8% were ceftriaxone non-susceptible, 78% were cotrimoxazole resistant, 30% were erythromycin resistant and 30% chloramphenicol resistant. There were no significant changes in resistance levels over the five-year period. The most common serotypes were 1 (11/50; 22%, 23F (8/50; 16%, 14 (6/50; 12%, 5 (5/50; 10% and 19A (3/50; 6%. Coverage by PCV7, PCV10 and PCV13 was 44%, 76% and 92% respectively. We identified novel multilocus sequence types and resistotypes using whole genome sequencing.This study suggests IPD is an important disease in Cambodian children and can have a significant mortality. PCV13 coverage of the serotypes determined in studied strains was high and consistent with another recent study. The phenotypic resistance patterns observed were similar to other regional studies. The use of whole genome sequencing in the present study provides additional typing and resistance information together with the description of novel sequence types and resistotypes.

  10. Characterisation of Invasive Streptococcus pneumoniae Isolated from Cambodian Children between 2007 – 2012

    Science.gov (United States)

    Giess, Adam; Soeng, Sona; Sar, Poda; Kumar, Varun; Nhoung, Pheakdey; Bousfield, Rachel; Turner, Paul; Stoesser, Nicole; Day, Nicholas P. J.; Parry, Christopher M.

    2016-01-01

    Background The 13-valent pneumococcal vaccine (PCV13) was introduced in Cambodia in January 2015. There are limited data concerning the common serotypes causing invasive pneumococcal disease (IPD). Knowledge of the circulating pneumococcal serotypes is important to monitor epidemiological changes before and after vaccine implementation. Methods All episodes of IPD defined by the isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or other sterile site in Cambodian children admitted to the Angkor Hospital for Children in Siem Reap, Northwestern Cambodia, between 1st January 2007 and 1st July 2012 were retrospectively studied. Streptococcus pneumoniae isolates that could be retrieved underwent phenotypic typing and whole genome sequencing. Results There were 90 Cambodian children hospitalized with IPD with a median (IQR) age of 2.3 years (0.9–6.2). The case fatality was 15.6% (95% CI 8–23). Of 50 Streptococcus pneumoniae isolates available for further testing, 46% were penicillin non-susceptible and 8% were ceftriaxone non-susceptible, 78% were cotrimoxazole resistant, 30% were erythromycin resistant and 30% chloramphenicol resistant. There were no significant changes in resistance levels over the five-year period. The most common serotypes were 1 (11/50; 22%), 23F (8/50; 16%), 14 (6/50; 12%), 5 (5/50; 10%) and 19A (3/50; 6%). Coverage by PCV7, PCV10 and PCV13 was 44%, 76% and 92% respectively. We identified novel multilocus sequence types and resistotypes using whole genome sequencing. Conclusions This study suggests IPD is an important disease in Cambodian children and can have a significant mortality. PCV13 coverage of the serotypes determined in studied strains was high and consistent with another recent study. The phenotypic resistance patterns observed were similar to other regional studies. The use of whole genome sequencing in the present study provides additional typing and resistance information together with the description of novel

  11. Genetic diversity of Streptococcus suis isolates as determined by comparative genome hybridization

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    Thi Hoa

    2011-07-01

    Full Text Available Abstract Background Streptococcus suis is a zoonotic pathogen that causes infections in young piglets. S. suis is a heterogeneous species. Thirty-three different capsular serotypes have been described, that differ in virulence between as well as within serotypes. Results In this study, the correlation between gene content, serotype, phenotype and virulence among 55 S. suis strains was studied using Comparative Genome Hybridization (CGH. Clustering of CGH data divided S. suis isolates into two clusters, A and B. Cluster A isolates could be discriminated from cluster B isolates based on the protein expression of extracellular factor (EF. Cluster A contained serotype 1 and 2 isolates that were correlated with virulence. Cluster B mainly contained serotype 7 and 9 isolates. Genetic similarity was observed between serotype 7 and serotype 2 isolates that do not express muramidase released protein (MRP and EF (MRP-EF-, suggesting these isolates originated from a common founder. Profiles of 25 putative virulence-associated genes of S. suis were determined among the 55 isolates. Presence of all 25 genes was shown for cluster A isolates, whereas cluster B isolates lacked one or more putative virulence genes. Divergence of S. suis isolates was further studied based on the presence of 39 regions of difference. Conservation of genes was evaluated by the definition of a core genome that contained 78% of all ORFs in P1/7. Conclusions In conclusion, we show that CGH is a valuable method to study distribution of genes or gene clusters among isolates in detail, yielding information on genetic similarity, and virulence traits of S. suis isolates.

  12. Characterization of Streptococcus pneumoniae isolates from Austrian companion animals and horses.

    Science.gov (United States)

    Ginders, Maximilian; Leschnik, Michael; Künzel, Frank; Kampner, Doris; Mikula, Claudia; Steindl, Georg; Eichhorn, Inga; Feßler, Andrea T; Schwarz, Stefan; Spergser, Joachim; Loncaric, Igor

    2017-11-14

    The aim of the present study was to investigate the genetic relatedness and the antimicrobial resistance profiles of a collection of Austrian Streptococcus pneumoniae isolates from companion animals and horses. A total of 12 non-repetitive isolates presumptively identified as S. pneumoniae were obtained during routinely diagnostic activities between March 2009 and January 2017. Isolates were confirmed as S. pneumoniae by bile solubility and optochin susceptibility testing, matrix-assisted laser desorption-ionization-time of flight (MALDI-TOF) mass spectrometry and sequence analysis of a part recA and the 16S rRNA genes. Isolates were further characterized by pneumolysin polymerase chain reaction (PCR) and genotyped by multilocus sequence typing (MLST). Antimicrobial susceptibility testing was performed and resistance genes were detected by specific PCR assays. All isolates were serotyped. Four sequence types (ST) (ST36, ST3546, ST6934 and ST6937) and four serotypes (3, 19A, 19F and 23F) were detected. Two isolates from twelve displayed a multidrug-resistance pheno- and genotype. This study represents the first comprehensive investigation on characteristics of S. pneumoniae isolates recovered from Austrian companion animals and horses. The obtained results indicate that common human sero- (23F) and sequence type (ST36) implicated in causing invasive pneumococcal disease (IPD) may circulate in dogs. Isolates obtained from other examined animals seem to be host-adapted.

  13. Streptococcus didelphis sp. nov., a streptococcus with marked catalase activity isolated from opossums (Didelphis virginiana) with suppurative dermatitis and liver fibrosis.

    Science.gov (United States)

    Rurangirwa, F R; Teitzel, C A; Cui, J; French, D M; McDonough, P L; Besser, T

    2000-03-01

    beta-Haemolytic, catalase-positive, Gram-positive cocci that formed chains in broth media but did not react with Lancefield group antisera were isolated from skin lesions, spleen, liver and lungs of nine opossums, including eight from a research colony and one from a wildlife rehabilitation organization. The isolates had vigorous catalase activity that was retained on initial passage on non-blood-containing media, but this activity was lost in subsequent passages. The use of standard phenotypic tests did not lead to satisfactory identification of these organisms beyond the genus level, even if the aberrant catalase reaction was not considered. The 16S rRNA gene sequence of the isolates was most similar (96%) to Streptococcus dysgalactiae, but distinct from that species as 16S rRNA gene similarity of different strains of S. dysgalactiae was > 99%. Characterization of biochemical reactions and cell-wall fatty acid profiles also revealed significant differences between the opossum isolates and all other known Streptococcus spp., thus it is proposed as a new species with the name Streptococcus didelphis, sp. nov. The type strain is ATCC 700828T.

  14. Serotypes and antibiotic susceptibility of Streptococcus pneumoniae isolates causative of invasive diseases in Mexican children.

    Science.gov (United States)

    Arredondo-García, José Luis; Calderón, Ernesto; Echániz-Aviles, Gabriela; Soto-Noguerón, Araceli; Arzate, Patricia; Amabile-Cuevas, Carlos F

    2011-03-02

    Streptococcus pneumoniae is a worldwide leading cause of morbidity and mortality, while susceptibility towards penicillin and macrolides can be less than 50% in many regions. A total of 150 isolates of S. pneumoniae causative of invasive diseases in children were characterized, of which 24.6% had a fatal outcome. The most prevalent serotypes were 19F, 6B, 23F and 14. Resistance to penicillin, erythromycin (mostly of macrolide-lincosamide-streptogramin resistance phenotype) or trimethoprim-sulfamethoxazole was found in more than 40% of the isolates, but no resistance phenotype appeared linked to lethality. Serotype 3 isolates, which were seldom resistant, had a twofold lethality rate compared to the total sample. Serotyping could provide a better outcome-predicting tool than susceptibility testing. The seven-valent vaccine does not include the most prevalent serotypes found in Mexico.

  15. Molecular epidemiology of group A streptococcus from pharyngeal isolates in Auckland, New Zealand, 2013.

    Science.gov (United States)

    Williamson, Deborah A; Moreland, Nicole J; Carter, Philip; Upton, Arlo; Morgan, Julie; Proft, Thomas; Lennon, Diana; Baker, Michael G; Dunbar, Rod; Fraser, John D

    2014-01-24

    To describe the molecular epidemiology of emm types associated with circulating pharyngeal group A streptococcus (GAS) isolates in Auckland, New Zealand. GAS isolates were collected over a 10-day period from a community pathology provider in Auckland. PCR analysis and sequencing of the emm gene was performed at the Institute of Environmental Science and Research. A total of 52 emm types were identified from 278 GAS isolates. The three most common emm types were emm1, emm89 and emm12. Overall, the experimental 30-valent GAS M protein vaccine covered 19 / 52 (37%) of emm types in our study. Our study provides baseline data on the circulating pharyngeal GAS emm types in Auckland. Future clinical and molecular surveillance of GAS pharyngitis is essential in the context of ongoing GAS vaccine development.

  16. Prevalence and Characteristics of Streptococcus canis Strains Isolated from Dogs and Cats

    Directory of Open Access Journals (Sweden)

    P. Lysková

    2007-01-01

    Full Text Available To determine the prevalence of Streptococcus canis in dogs and cats, a total of 926 swabs were examined bacteriologically in the period from 2003 to 2005. Eighty-six isolates obtained from various anatomical locations were further characterized for their phenotypic properties. The most frequently isolated biotype produced phosphatase, leucine amidopeptidase, arginine dihydrolase, alpha-D- and beta-D-galactosidase and fermented lactose and ribose. Additional identification by species-specific amplification of the 16S-23S rRNA intergenic spacer region was consistent with S. canis. All isolates were susceptible to penicillin G and ampicillin. The least effective antimicrobial agent was found to be tetracycline (only 33.8% of susceptible strains.

  17. Highly Variable Streptococcus oralis Strains Are Common among Viridans Streptococci Isolated from Primates.

    Science.gov (United States)

    Denapaite, Dalia; Rieger, Martin; Köndgen, Sophie; Brückner, Reinhold; Ochigava, Irma; Kappeler, Peter; Mätz-Rensing, Kerstin; Leendertz, Fabian; Hakenbeck, Regine

    2016-01-01

    Viridans streptococci were obtained from primates (great apes, rhesus monkeys, and ring-tailed lemurs) held in captivity, as well as from free-living animals (chimpanzees and lemurs) for whom contact with humans is highly restricted. Isolates represented a variety of viridans streptococci, including unknown species. Streptococcus oralis was frequently isolated from samples from great apes. Genotypic methods revealed that most of the strains clustered on separate lineages outside the main cluster of human S. oralis strains. This suggests that S. oralis is part of the commensal flora in higher primates and evolved prior to humans. Many genes described as virulence factors in Streptococcus pneumoniae were present also in other viridans streptococcal genomes. Unlike in S. pneumoniae, clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein (Cas) gene clusters were common among viridans streptococci, and many S. oralis strains were type PI-2 (pilus islet 2) variants. S. oralis displayed a remarkable diversity of genes involved in the biosynthesis of peptidoglycan (penicillin-binding proteins and MurMN) and choline-containing teichoic acid. The small noncoding cia-dependent small RNAs (csRNAs) controlled by the response regulator CiaR might contribute to the genomic diversity, since we observed novel genomic islands between duplicated csRNAs, variably present in some isolates. All S. oralis genomes contained a β-N-acetyl-hexosaminidase gene absent in S. pneumoniae, which in contrast frequently harbors the neuraminidases NanB/C, which are absent in S. oralis. The identification of S. oralis-specific genes will help us to understand their adaptation to diverse habitats. IMPORTANCE Streptococcus pneumoniae is a rare example of a human-pathogenic bacterium among viridans streptococci, which consist of commensal symbionts, such as the close relatives Streptococcus mitis and S. oralis. We have shown that S. oralis can frequently

  18. Chemical composition and nutrient degradability in elephant grass silage inoculated with Streptococcus bovis isolated from the rumen

    Directory of Open Access Journals (Sweden)

    DANIELE J. FERREIRA

    2014-03-01

    Full Text Available The objective of the present study was to assess the chemical and bromatological composition and in situ degradability of elephant grass silages inoculated with Streptococcus bovis isolated from cattle rumen. A complete randomized design was used with four treatments and six replications: elephant grass silage, elephant grass silage inoculated with 106 CFU/g Streptococcus bovis JB1 strains; elephant grass silage inoculated with 106 CFU/g Streptococcus bovis HC5 strains; elephant grass silage inoculated with 106 CFU/g Enterococcus faecium with six replications each. The pH and ammoniacal nitrogen values were lower (P<0.05 for the silages inoculated with Streptococcus bovis JB1 and HC5, respectively. The silage inoculated with Streptococcus bovis had a higher crude protein content (P<0.05 and there were no differences for the fiber contents in the silage. The (asoluble fraction degradability, especially in the silages inoculated with Streptococcus bovis JB1 and HC5, had higher values, 30.77 and 29.97%, for dry matter and 31.01 and 36.66% for crude protein, respectively. Inoculation with Streptococcus bovis improved the fermentation profile, protein value and rumen degradability of the nutrients.

  19. Bovine Endometrial Epithelial Cells Scale Their Pro-inflammatory ResponseIn vitroto PathogenicTrueperella pyogenesIsolated from the Bovine Uterus in a Strain-Specific Manner.

    Science.gov (United States)

    Ibrahim, Mohammad; Peter, Sarah; Wagener, Karen; Drillich, Marc; Ehling-Schulz, Monika; Einspanier, Ralf; Gabler, Christoph

    2017-01-01

    Among different bacteria colonizing the bovine uterus, Trueperella pyogenes is found to be associated with clinical endometritis (CE). The ability of cows to defend against T. pyogenes infections depends on the virulence of invading bacteria and on the host's innate immunity. Therefore, to gain insights into bacterial factors contributing to the interplay of this host pathogen, two strains of T. pyogenes were included in this study: one strain (TP2) was isolated from the uterus of a postpartum dairy cow developing CE and a second strain (TP5) was isolated from a uterus of a healthy cow. The two strains were compared in terms of their metabolic fingerprints, growth rate, virulence gene transcription, and effect on bovine endometrial epithelial cells in vitro . In addition, the effect of the presence of peripheral blood mononuclear cells (PBMCs) on the response of endometrial epithelial cells was evaluated. TP2, the strain isolated from the diseased cow, showed a higher growth rate, expressed more virulence factors ( cbpA, nanH, fimE , and fimG ), and elicited a higher mRNA expression of pro-inflammatory factors ( PTGS2, CXCL3 , and IL8 ) in bovine endometrial epithelial cells compared with TP5, the strain isolated from the healthy cow. The presence of PBMCs amplified the mRNA expression of pro-inflammatory factors ( PTGS2, CXCL3, IL1A, IL6 , and IL8 ) in bovine endometrial epithelial cells co-cultured with live TP2 compared with untreated cells, especially as early as after 4 h. In conclusion, particular strain characteristics of T. pyogenes were found to be important for the development of CE. Furthermore, immune cells attracted to the site of infection might also play an important role in up-regulation of the pro-inflammatory response in the bovine uterus and thus significantly contribute to the host-pathogen interaction.

  20. Comparative Genome Analyses of Streptococcus suis Isolates from Endocarditis Demonstrate Persistence of Dual Phenotypic Clones.

    Directory of Open Access Journals (Sweden)

    Mari Tohya

    Full Text Available Many bacterial species coexist in the same niche as heterogeneous clones with different phenotypes; however, understanding of infectious diseases by polyphenotypic bacteria is still limited. In the present study, encapsulation in isolates of the porcine pathogen Streptococcus suis from persistent endocarditis lesions was examined. Coexistence of both encapsulated and unencapsulated S. suis isolates was found in 26 out of 59 endocarditis samples. The isolates were serotype 2, and belonged to two different sequence types (STs, ST1 and ST28. The genomes of each of the 26 pairs of encapsulated and unencapsulated isolates from the 26 samples were sequenced. The data showed that each pair of isolates had one or more unique nonsynonymous mutations in the cps gene, and the encapsulated and unencapsulated isolates from the same samples were closest to each other. Pairwise comparisons of the sequences of cps genes in 7 pairs of encapsulated and unencapsulated isolates identified insertion/deletions (indels ranging from one to 104 bp in different cps genes of unencapsulated isolates. Capsule expression was restored in a subset of unencapsulated isolates by complementation in trans with cps expression vectors. Examination of gene content common to isolates indicated that mutation frequency was higher in ST28 pairs than in ST1 pairs. Genes within mobile genetic elements were mutation hot spots among ST28 isolates. Taken all together, our results demonstrate the coexistence of dual phenotype (encapsulated and unencapsulated bacterial clones and suggest that the dual phenotypes arose independently in each farm by means of spontaneous mutations in cps genes.

  1. Community-acquired soft-tissue pyogenic abscesses in Mulago ...

    African Journals Online (AJOL)

    Background: Clinical practice, for a long time, has dwelt on study and management of pyogenic abscesses without distinction between nosocomial and community-acquired types. This study aimed at identifying the bacteria isolated from community-acquired acute subcutaneous and soft tissue pyogenic abscesses.

  2. Characterization of Streptococcus milleri Group Isolates from Expectorated Sputum of Adult Patients with Cystic Fibrosis▿

    Science.gov (United States)

    Grinwis, Margot E.; Sibley, Christopher D.; Parkins, Michael D.; Eshaghurshan, Christina S.; Rabin, Harvey R.; Surette, Michael G.

    2010-01-01

    With the recent insights into the Streptococcus milleri group (SMG) as pulmonary pathogens in patients with cystic fibrosis (CF), we sought to characterize 128 isolates from the sputum of adults with CF, along with 45 isolates from patients with invasive diseases for comparison. The tests performed included Lancefield grouping; tests for hemolysis; tests for the production of hyaluronidase, chondroitin sulfatase, DNase, proteases, and hydrogen peroxide; and PCR for the detection of the intermedilysin gene (ily). We also generated biochemical profiles with the Rapid ID Strep 32 API system and tested cell-free supernatants for the presence of the signal molecule autoinducer-2 (AI-2) using a Vibrio harveyi bioassay with a subset of CF strains. The S. intermedius isolates from both strain collections were similar, while the S. constellatus and S. anginosus isolates yielded several biotypes that differed in prevalence between the two strain collections. Beta-hemolytic, Lancefield group C S. constellatus comprised 74.4% of the S. constellatus isolates from patients with CF but only 13.3% of the corresponding isolates from patients with invasive infections. This was the only S. constellatus biotype associated with pulmonary exacerbations. Hyaluronidase-positive S. anginosus was detected only among the isolates from patients with CF. Strain-to-strain variability in AI-2 expression was evident, with the mean values being the highest for S. anginosus, followed by S. constellatus and then S. intermedius. Cluster analysis and 16S rRNA sequencing revealed that the species of SMG could be accurately determined with a minimum of three phenotypic tests: tests for the Lancefield group, hyaluronidase production, and chondroitin sulfatase production. Furthermore, isolates from patients with invasive infections clustered with isolates from the sputum of patients with CF, suggesting that the respiratory tract isolates were equally pathogenic. PMID:20007382

  3. Characterization of Streptococcus milleri group isolates from expectorated sputum of adult patients with cystic fibrosis.

    Science.gov (United States)

    Grinwis, Margot E; Sibley, Christopher D; Parkins, Michael D; Eshaghurshan, Christina S; Rabin, Harvey R; Surette, Michael G

    2010-02-01

    With the recent insights into the Streptococcus milleri group (SMG) as pulmonary pathogens in patients with cystic fibrosis (CF), we sought to characterize 128 isolates from the sputum of adults with CF, along with 45 isolates from patients with invasive diseases for comparison. The tests performed included Lancefield grouping; tests for hemolysis; tests for the production of hyaluronidase, chondroitin sulfatase, DNase, proteases, and hydrogen peroxide; and PCR for the detection of the intermedilysin gene (ily). We also generated biochemical profiles with the Rapid ID Strep 32 API system and tested cell-free supernatants for the presence of the signal molecule autoinducer-2 (AI-2) using a Vibrio harveyi bioassay with a subset of CF strains. The S. intermedius isolates from both strain collections were similar, while the S. constellatus and S. anginosus isolates yielded several biotypes that differed in prevalence between the two strain collections. Beta-hemolytic, Lancefield group C S. constellatus comprised 74.4% of the S. constellatus isolates from patients with CF but only 13.3% of the corresponding isolates from patients with invasive infections. This was the only S. constellatus biotype associated with pulmonary exacerbations. Hyaluronidase-positive S. anginosus was detected only among the isolates from patients with CF. Strain-to-strain variability in AI-2 expression was evident, with the mean values being the highest for S. anginosus, followed by S. constellatus and then S. intermedius. Cluster analysis and 16S rRNA sequencing revealed that the species of SMG could be accurately determined with a minimum of three phenotypic tests: tests for the Lancefield group, hyaluronidase production, and chondroitin sulfatase production. Furthermore, isolates from patients with invasive infections clustered with isolates from the sputum of patients with CF, suggesting that the respiratory tract isolates were equally pathogenic.

  4. Daptomycin tested against 915 bloodstream isolates of viridans group streptococci (eight species) and Streptococcus bovis.

    Science.gov (United States)

    Streit, Jennifer M; Steenbergen, Judith N; Thorne, Grace M; Alder, Jeffrey; Jones, Ronald N

    2005-04-01

    To evaluate the activity of daptomycin tested against numerous species of viridans group streptococci and Streptococcus bovis, which are associated with wound infections, sepsis, cellulitis, endocarditis, abscesses and dental caries. The incidence of penicillin-resistant (non-susceptible) and MLS(B)-resistant strains among viridans group streptococci often varies by species. The activity of daptomycin was compared with seven other antimicrobial classes using reference broth microdilution and disc diffusion methods tested against 915 bacteraemic isolates of streptococci (815 viridans group strains; 100 S. bovis). Among all species of viridans group streptococci and S. bovis, 99.9% of isolates were susceptible to daptomycin (MIC values, viridans group streptococci, as well as S. bovis, with all MIC values at < or =2 mg/L.

  5. Effect of poly-hexamethylene biguanide hydrochloride (PHMB) treated non-sterile medical gloves upon the transmission of Streptococcus pyogenes, carbapenem-resistant E. coli, MRSA and Klebsiella pneumoniae from contact surfaces.

    Science.gov (United States)

    Ali, S; Wilson, A P R

    2017-08-17

    Reduction of accidental contamination of the near-patient environment has potential to reduce acquisition of healthcare-associated infection(s). Although medical gloves should be removed when soiled or touching the environment, compliance is variable. The use of antimicrobial-impregnated medical gloves could reduce the horizontal-transfer of bacterial contamination between surfaces. Determine the activity of antimicrobial-impregnated gloves against common hospital pathogens: Streptococcus pyogenes, carbapenem-resistant E.coli (CREC), MRSA and ESBL-producing Klebsiella pneumoniae. Fingerpads (~1cm 2 ) of PHMB-treated and untreated gloves were inoculated with 10 μL (~10 4 colony-forming-units [cfu]) of test-bacteria prepared in heavy-soiling (0.5%BSA), blood or distilled-water (no-soiling) and sampled after 0.25, 1, 10 or 15 min contact-time. Donor surfaces (~1cm 2 computer-keys) contaminated with wet/dry inoculum were touched with the fingerpad of treated/untreated gloves and subsequently pressed onto recipient (uncontaminated) computer-keys. Approximately 4.50log 10 cfu of all bacteria persisted after 15 min on untreated gloves regardless of soil-type. In the absence of soiling, PHMB-treated gloves reduced surface-contamination by ~4.5log 10 cfu (>99.99%) within 10 min of contact-time but only ~2.5log 10 (>99.9%) and ~1.0log 10 reduction respectively when heavy-soiling or blood was present. Gloves became highly-contaminated (~4.52log 10 -4.91log 10 cfu) when handling recently-contaminated computer-keys. Untreated gloves contaminated "recipient" surfaces (~4.5log 10 cfu) while PHMB-treated gloves transferred fewer bacteria (2.4-3.6log 10 cfu). When surface contamination was dry, PHMB gloves transferred fewer bacteria (0.3-0.6log 10 cfu) to "recipient" surfaces than untreated gloves (1.0-1.9log 10 ; P gloves may be useful in preventing dissemination of organisms in the near-patient environment during routine care. However they are not a substitute for

  6. Inference of Antibiotic Resistance and Virulence Among Diverse Group A Streptococcus Strains Using emm Sequencing and Multilocus Genotyping Methods

    Science.gov (United States)

    2009-09-04

    Surveillance Center, Silver Spring, Maryland, United States of America Abstract Background: Group A Streptococcus pyogenes (GAS) exhibits a high...david.metzgar@med.navy.mil Introduction Group A Streptococcus pyogenes (GAS) is a common agent of pharyngitis, febrile respiratory infection, and...Spratt BG, Kalia A, Cross JH, Bessen DE (2001) Multilocus sequence typing of Streptococcus pyogenes and the relationship between emm type and clone. Infect

  7. Comparative epidemiology of Streptococcus pyogenes emm-types causing invasive and noninvasive infections in French children by use of high-resolution melting-polymerase chain reaction.

    Science.gov (United States)

    d'Humières, Camille; Bidet, Philippe; Levy, Corinne; Béchet, Stéphane; Bonacorsi, Stéphane; Bingen, Edouard; Cohen, Robert

    2015-06-01

    This study aims to analyze the epidemiology of Group A streptococci (GAS) emm-types causing invasive and noninvasive infections in French children. From September 2009 to May 2011, we analyzed GAS isolates from 585 pharyngitis, 125 invasive infections and, for the first time in France, 32 healthy carriers. M protein gene (emm) typing of the isolates was carried out by a new rapid technique, combining 3 multiplex-polymerase chain reactions (PCRs) coupled to high-resolution melting (HRM) curves, able to detect 13 major emm-types (emm 1, 3, 4, 6, 11, 12, 22, 28, 75, 77, 87, 89 and 102). GAS belonging to emm-type 1 were more frequently found among invasive infections than among pharyngitis (24.0% vs. 11.5%, P type 4, 17.4% vs. 6.4%, P = 0.002 and emm-type 89, 9.9% vs. 2.4%, P = 0.006, respectively) and emm 3 and 4 were more common in cases of pharyngitis associated with scarlet fever (21.6% vs. 6.0%, P epidemiological studies. Comparison of GAS causing invasive and noninvasive infections in the same population of children displays an unbalanced repartition of emm-types.

  8. Pathogenesis of Streptococcus infantarius subspecies coli Isolated from Sea Otters with Infective Endocarditis.

    Science.gov (United States)

    Counihan, Katrina L; Gill, Verena A; Miller, Melissa A; Burek-Huntington, Kathleen A; LeFebvre, Rance B; Byrne, Barbara A

    2015-06-01

    The Gram positive bacterial coccus Streptococcus infantarius subspecies coli is increasingly linked with development of fatal vegetative infective endocarditis and septicemia in humans, sea otters (Enhydra lutris) and other animals. However, the pathogenesis of these infections is poorly understood. Using S. infantarius subsp. coli strains isolated from sea otters with infective endocarditis, this study evaluated adherence and invasion of epithelial and endothelial cells, adherence to extracellular matrix components, and macrophage survival. Significant adherence to endothelial-derived cells was observed for 62% of isolates, 24% adhered to epithelial cell lines, and 95% invaded one or both cell types in vitro. The importance of the hyaluronic acid capsule in host cell adherence and invasion was also evaluated. Capsule removal significantly reduced epithelial adherence and invasion for most S. infantarius subsp. coli isolates, suggesting that the capsule facilitates attachment to and invasion of epithelium. Enzyme-linked immunosorbent assay testing revealed that all isolates adhered significantly to the extracellular matrix components collagen IV, fibronectin, laminin and hyaluronic acid. Finally, significant bacterial survival following phagocytosis by macrophages was apparent for 81% of isolates at one or more time points. Taken collectively these findings indicate that S. infantarius subsp. coli has multiple pathogenic properties that may be important to host colonization, invasion and disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Serotypes and antimicrobial resistance of meningeal isolates of Streptococcus pneumonia. Cuba, 2007-2012

    Directory of Open Access Journals (Sweden)

    Gilda Toraño-Peraza

    2014-12-01

    Full Text Available An observational study was conducted to know the serotypes and antimicrobial susceptibility of isolates of Streptococcus pneumoniae responsible for meningitis in Cuba, where there is no vaccine yet to prevent invasive pneumococcal disease. The study included the total number of isolates submitted to the "Pedro Kourí" Institute between 2007 and 2012 (N=237. Serotypes identification was performed using capsular swelling test and antimicrobial susceptibility was studied by determining the minimum inhibitory concentration using the broth microdilution method. Predominant serotypes were 6A, 6B, 14, 19F and 23F and other non-vaccinal 18 serogroups/serotypes were identified in 29.1% of the isolates. A tendency to an increased resistance to penicillin (44.3 % was observed; the most common resistance patterns were: penicillin-trimethoprim/sulfamethoxazole and penicillin-erythromycin (21.1% and 10.5%, respectively. The largest number of isolates resistant to penicillin was in serotypes 6B, 14, 19F and 23F and the possibility of resistant non-vaccine serotypes emergence should be considered. The results show that 70.4 % of the isolates studied corresponds to the serotypes included in 13-valent conjugated pneumococcal vaccine, but with 10-valent it would achieve a lower vaccination potential coverage (56.1%. This information must be considered when evaluating the decision to use in Cuba any commercially available vaccine or the proposal of another strategy of vaccination from autochthonous vaccine candidates.

  10. The resistance to antibiotics of strains of Streptococcus viridans, Streptococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Proteus and Klebsiella isolated in Poland*

    Science.gov (United States)

    Jeljaszewicz, J.; Hawiger, J.

    1966-01-01

    A nation-wide survey has been carried out in Poland into the susceptibility of six genera of bacteria to eight antibiotics. The antibiotic-resistance of streptococci differed from that of the Gram-negative rods studied. Escherichia coli, Klebsiella and Pseudomonas aeruginosa are known to be completely resistant to penicillin. Streptococcus faecalis was much more resistant to antibiotics than Streptococcus viridans (highest resistance to streptomycin — 90.3% and 74.9%, respectively; least resistance to chloramphenicol — 47.3% and 9.1%). More than 90% of all Pseudomonas aeruginosa strains isolated were resistant to all the antibiotics; high resistance was also exhibited by E. coli (94.5% resistant to erythromycin and 59.5% to chloramphenicol), Proteus (92.3% to penicillin and 63.0% to chloramphenicol) and Klebsiella (84.0% to erythromycin and 62.8% to oxytetracycline). PMID:5332528

  11. Diversity of seM in Streptococcus equi subsp. equi isolated from strangles outbreaks.

    Science.gov (United States)

    Libardoni, Felipe; Vielmo, Andréia; Farias, Luana; Matter, Letícia Beatriz; Pötter, Luciana; Spilki, Fernando Rosado; de Vargas, Agueda Castagna

    2013-03-23

    Strangles is the main upper respiratory tract disease of horses. There are currently no studies on the changes in alleles of the M protein gene (seM) in Brazilian isolates of Streptococcus equi ssp. equi (S. equi). This study aimed to analyze and differentiate molecularly S. equi isolates from equine clinical specimens from southern Brazil, between 1994 and 2010. seM alleles were analyzed in 47 isolates of S. equi obtained from clinical cases of strangles (15 Thoroughbred horses, 29 Crioulo breed horses and three Brasileiro de Hipismo--BH). seM alleles characterization was performed by comparing variable region sequences of the seM gene. The alleles were also phylogenetically grouped by Neighbor-joining analysis, which demonstrated the geographic distribution of those in properties from southern Brazil. Fifteen alleles of the gene seM were found among the 47 S. equi isolates analyzed. Among these, only one allele (seM-61), which was identified in seven isolates (14.9%), was found in the database PubMLST-seM. Within the new alleles, allele seM-115 was the most prevalent, having been found in 13 isolates (27.7%), followed by allele seM-117 in 10 isolates (21.3%). In the Brazilian horse population studied, there is greater diversity of M protein alleles in S. equi isolates compared to worldwide data deposited in PubMLST-seM. Among the 15 seM alleles identified, only one allele sequence was previously published. The alleles identification is important to control the disease by guiding selection of strains for the manufacture of commercial and autogenous vaccines. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Streptococcus halotolerans sp. nov. isolated from the respiratory tract of Marmota himalayana in Qinghai-Tibet Plateau of China.

    Science.gov (United States)

    Niu, Lina; Lu, Shan; Hu, Shoukui; Jin, Dong; Lai, Xinhe; Yang, Jing; Chen, Cuixia; Wang, Yiting; Bai, Xiangning; Lan, Ruiting; Lv, Gang; Xie, Yingping; Ye, Changyun; Xu, Jianguo

    2016-10-01

    Two Gramstaining-positive, catalase-negative, α-hemolytic, coccus-shaped organisms were isolated separately from the respiratory tracts of two Marmota himalayana animals from the Qinghai-Tibet Plateau, PR China. Morphological, biological, biochemical, and molecular genetic studies were performed on these two isolates (HTS9T and HTS12). Their biochemical characteristics, such as acid production from different sugars and enzymatic activities, indicated that they represented a member of the genus Streptococcus. They are most closely related to Streptococcus thoraltensis CIP 105518T based on sequence analysis of their 16S rRNA, groEL, sodA and rpoB genes, with similarities of 97.6, 89.9, 92.6 and 91.1 % the four genes respectively. The whole genome phylogenetic tree reconstructed using 372 core genes from 65 genomes of members of the genus Streptococcus validates that HTS9T forms a distinct subline and exhibits specific phylogenetic affinity with S. thoraltensis. In silico DNA-DNA hybridization of HTS9T showed a DNA reassociation value of 32.1 %, closest to that of S. thoraltensis CIP 105518T. Based on their phenotypic characteristics and in particular the phylogenetic findings (DNA-DNA hybridization, three phylogenetic trees built from the partial 16S rRNA/housekeeping genes, and from 372 core genes of 65 genomes of members of the genus Streptococcus), we propose with confidence that strains HTS9T and HTS12 should be classified as representing a novel species of the genus Streptococcus, Streptococcus halotolerans sp. nov. The type strain is HTS9T (=DSM 101996T=CGMCC1.15532T). Genome analysis of Streptococcus halotolerans sp. nov. shows that its genome is 1 823 556 bp long with a DNA G+C content of 39.9 mol% and contains 2068 genes.

  13. Emergence in France of Multiple Clones of Clinical Streptococcus pneumoniae Isolates with High-Level Resistance to Amoxicillin

    OpenAIRE

    Doit, Catherine; Loukil, Chawki; Fitoussi, Frederic; Geslin, Pierre; Bingen, Edouard

    1999-01-01

    The genetic relatedness of French isolates of Streptococcus pneumoniae highly resistant to amoxicillin (MIC, ≥4 μg/ml, equal to or exceeding those of penicillin) was investigated by molecular fingerprinting. The results suggest that high-level resistance to amoxicillin has emerged within preexisting penicillin-resistant clones.

  14. Draft genome sequence of Streptococcus equi subsp. zooepidemicus strain S31A1, isolated from equine infectious endometritis

    DEFF Research Database (Denmark)

    da Piedade, Isabelle; Skive, Bolette; Christensen, Henrik

    2013-01-01

    We present the draft genome sequence of Streptococcus equi subsp. zooepidemicus S31A1, a strain isolated from equine infectious endometritis in Denmark. Comparative analyses of this genome were done with four published reference genomes: S. zooepidemicus strains MGCS10565, ATCC 35246, and H70 and S...

  15. Draft genome sequences of three virulent Streptococcus thermophilus bacteriophages isolated from the dairy environment in the Veneto region of Italy

    DEFF Research Database (Denmark)

    Duarte, Viní­cius da Silva; Giaretta, Sabrina; Treu, Laura

    2018-01-01

    Streptococcus thermophilus, a very important dairy species, is constantly threatened by phage infection. We report the genome sequences of three S. thermophilus bacteriophages isolated from a dairy environment in the Veneto region of Italy. These sequences will be used for the development of new...

  16. The sensitivity to antibiotics of strains of group B streptococcus isolates from pregnant women in Belgrade

    Directory of Open Access Journals (Sweden)

    Jovanović Luka

    2016-01-01

    Full Text Available Introduction: Group B streptococcus (GBS is a significant human pathogen. GBS colonizes the vagina and it is one of the most important causes of early neonatal sepsis and meningitis. In many countries, screening of pregnant women and intrapartal use of antibiotics are common practice. Macrolide and lincosamide resistant strains of GBS are a significant problem, because these antibiotics are the second line therapy in case of penicillin allergy. Aim: Our aim was to investigate the frequency of antibiotic resistant strains of GBS and to detect macrolide resistance phenotypes in GBS strains obtained from pregnant women in Belgrade. Material and Methods: 105 GBS isolates were obtained from vaginal swabs of pregnant women attending two Gynecology and Obstetrics Centers in Belgrade. The isolates were tested for antimicrobial susceptibility pattern and D test were performed on Mueller Hinton agar. Results: Macrolide and lincosamide resistance was found in 30.4 %, and 23.8 % of isolates, respectively. There was a high frequency of tetracycline resistant strains (88.6 %. Most frequent macrolide resistant phenotype was iMLSb (macrolide and inducibile lincosamide resistance (62.4%. Conclusion: The results of our study indicate that there is a high level of macrolide resistance among GBS isolates in Serbia and the active surveillance is needed.

  17. Virulence genes and genetic diversity of Streptococcus suis serotype 2 isolates from Thailand.

    Science.gov (United States)

    Maneerat, K; Yongkiettrakul, S; Kramomtong, I; Tongtawe, P; Tapchaisri, P; Luangsuk, P; Chaicumpa, W; Gottschalk, M; Srimanote, P

    2013-11-01

    Isolates of Streptococcus suis from different Western countries as well as those from China and Vietnam have been previously well characterized. So far, the genetic characteristics and relationship between S. suis strains isolated from both humans and pigs in Thailand are unknown. In this study, a total of 245 S. suis isolates were collected from both human cases (epidemic and sporadic) and pigs (diseased and asymptomatic) in Thailand. Bacterial strains were identified by biochemical tests and PCR targeting both, the 16S rRNA and gdh genes. Thirty-six isolates were identified as serotype 2 based on serotyping and the cps2-PCR. These isolates were tested for the presence of six virulence-associated genes: an arginine deiminase (arcA), a 38-kDa protein and protective antigen (bay046), an extracellular factor (epf), an hyaluronidase (hyl), a muramidase-released protein (mrp) and a suilysin (sly). In addition, the genetic diversities of these isolates were studied by RAPD PCR and multilocus sequence typing (MLST) analysis. Four virulence-associated gene patterns (VAGP 1 to 4) were obtained, and the majority of isolates (32/36) carried all genes tested (VAGP1). Each of the three OPB primers used provided 4 patterns designated RAPD-A to RAPD-D. Furthermore, MLST analysis could also distinguish the 36 isolates into four sequence types (STs): ST1 (n = 32), ST104 (n = 2), ST233 (n = 1) and a newly identified ST, ST336 (n = 1). Dendrogram constructions based on RAPD patterns indicated that S. suis serotype 2 isolates from Thailand could be divided into four groups and that the characteristics of the individual groups were in complete agreement with the virulence gene profiles and STs. The majority (32/36) of isolates recovered from diseased pigs, slaughterhouse pigs or human patients could be classified into a single group (VAGP1, RAPD-A and ST1). This genetic information strongly suggests the transmission of S. suis isolates from pigs to humans in Thailand. Our findings are

  18. Milleri group streptococcus--a stepchild in the viridans family.

    Science.gov (United States)

    Siegman-Igra, Y; Azmon, Y; Schwartz, D

    2012-09-01

    The purpose of this investigation was to provide a comprehensive review of the pathogenic role and spectrum of disease of milleri group streptococci, with special attention to bloodstream invasion and to possible differential roles among the three species. All consecutive isolates of milleri group streptococci from any anatomic source, during a 37-month period, in a tertiary care teaching hospital in Tel-Aviv, Israel, were thoroughly investigated. Identification to the species level was performed by an automated system.Streptococcus anginosus constituted 82% of the 245 patient-unique isolates from hospitalized patients. All nonurinary isolates were involved in pyogenic infections mostly originating from the gastrointestinal tract, with bacteremia in 28 cases. The 71 urinary isolates represented either urinary tract infection or nonsignificant bacteriuria. No specific association could be detected between species and the infection site, except for a higher relative representation of Streptococcus constellatus in bacteremia. Milleri group streptococci are common in clinical practice and play a different pathogenic role to other viridans streptococci. Due to their invariable association with pyogenic processes, their presence in blood warrants immediate focus identification. In addition, they have a previously unappreciated clinical niche concerning urinary tract infection. The identification of viridans streptococci to the species level is of paramount clinical significance.

  19. Antimicrobial susceptibility of Streptococcus suis isolated from clinically healthy swine in Brazil.

    Science.gov (United States)

    Soares, Taíssa Cook Siqueira; Paes, Antonio Carlos; Megid, Jane; Ribolla, Paulo Eduardo Martins; Paduan, Karina dos Santos; Gottschalk, Marcelo

    2014-04-01

    Streptococcus suis is an important pathogen in the swine industry. This study is the first to report on the antimicrobial susceptibility of S. suis isolated from clinically healthy pigs in Brazil; the fourth major pork producer in the world. The antimicrobial susceptibility of 260 strains was determined by disc diffusion method. Strains were commonly susceptible to ceftiofur, cephalexin, chloramphenicol, and florfenicol, with more than 80% of the strains being susceptible to these antimicrobials. A high frequency of resistance to some of the antimicrobial agents was demonstrated, with resistance being most common to sulfa-trimethoprim (100%), tetracycline (97.69%), clindamycin (84.61%), norfloxacin (76.92%), and ciprofloxacin (61.15%). A high percentage of multidrug resistant strains (99.61%) were also found. The results of this study indicate that ceftiofur, cephalexin, and florfenicol are the antimicrobials of choice for empirical control of the infections caused by S. suis.

  20. Assessment and characterization of biofilm formation among human isolates of Streptococcus dysgalactiae subsp. equisimilis.

    Science.gov (United States)

    Genteluci, Gabrielle Limeira; Silva, Ligia Guedes; Souza, Maria Clara; Glatthardt, Thaís; de Mattos, Marcos Corrêa; Ejzemberg, Regina; Alviano, Celuta Sales; Figueiredo, Agnes Marie Sá; Ferreira-Carvalho, Bernadete Teixeira

    2015-12-01

    The capacity to form biofilm is considered a protective mechanism that allows the bacteria to survive and proliferate in hostile environments, facilitating the maintenance of the infectious process. Recently, biofilm has become a topic of interest in the study of the human pathogen group A Streptococcus (GAS). Although GAS has not been associated with infection on medical implants, the presence of microcolonies embedded in an extracellular matrix on infected tissues has been reported. Despite the similarity between GAS and Streptococcus dysgalactiae subspecies equisimilis (SDSE), there are no studies in the literature describing the production of biofilm by SDSE. In this work, we assessed and characterized biofilm development among SDSE human isolates of group C. The in vitro data showed that 59.3% of the 118 isolates tested were able to form acid-induced biofilm on glass, and 28% formed it on polystyrene surfaces. More importantly, biofilm was also formed in a foreign body model in mice. The biofilm structure was analyzed by confocal laser scanning microscopy, transmission electron microscopy, and scanning electron microscopy. Long fibrillar-like structures were observed by scanning electron microscopy. Additionally, the expression of a pilus associated gene of SDSE was increased for in vitro sessile cells compared with planktonics, and when sessile cells were collected from biofilms formed in the animal model compared with that of in vitro model. Results obtained from the immunofluorescence microscopy indicated the biofilm was immunogenic. Our data also suggested a role for proteins, exopolysaccharide and extracellular DNA in the formation and accumulation of biofilm by SDSE. Copyright © 2015 Elsevier GmbH. All rights reserved.

  1. Serotypes and antibiotic resistance in Group B streptococcus isolated from patients at the Maternity Hospital, Kuwait.

    Science.gov (United States)

    Boswihi, Samar S; Udo, Edet E; Al-Sweih, Noura

    2012-01-01

    A total of 143 group B streptococcus (GBS) isolates collected from mothers at the Maternity Hospital in Kuwait were investigated for their serotypes and antibiotic resistance, and screened by PCR for the carriage of genes for resistance to tetracycline (tetk, tetM, tetL, tetO), erythromycin (ermA, ermB, ermC, ermTR, ermM, mefA, mefE, msrA) and aminoglycosides (aph3, ant4, ant6). All isolates were serotyped using a latex agglutination test. Most of the isolates belonged to serotypes V (38.5 %), III (20.9 %), Ia (7.7 %) and II (11.2 %). Sixteen isolates (11.2 %) were nontypable. All isolates were susceptible to penicillin, ampicillin and cefotaxime (MICs 0.016-0.094 µg ml(-1)) but were resistant to trimethoprim (92.3 %), tetracycline (89.5 %), minocycline (89.5 %), high-level kanamycin (76.9 %), chloramphenicol (30.0 %), erythromycin (12.6 %), clindamycin (7.0 %), high-level streptomycin (3.5 %) and ciprofloxacin (0.7 %). The tetracycline-resistant isolates contained tetM (94.5 %), tetO (3.9 %), tetL (1.6 %) and tetK (0.8 %). The erythromycin-resistant isolates contained ermB (61.1 %), ermTR (38.9 %), ermA (5.5 %), mefA (5.5 %) and mefE (11 %). All high-level kanamycin-resistant isolates contained aph3. One of the high-level streptomycin-resistant isolates contained ant6. Partial DNA sequencing of aph3 revealed sequences with 99 % similarity to aph3 found in Enterococcus faecium, Enterococcus faecalis, Staphylococcus aureus and Staphylococcus epidermidis, suggesting that the GBS isolates could have acquired aph3 from other Gram-positive cocci. The high proportion of isolates with resistance to tetracycline, high-level kanamycin and trimethoprim, and the increase in the prevalence of erythromycin resistance, represents an emerging public health concern that needs further surveillance.

  2. Genotyping and serotyping of macrolide and multidrug resistant Streptococcus pneumoniae isolated from carrier children

    Directory of Open Access Journals (Sweden)

    S F Swedan

    2016-01-01

    Full Text Available Aims: Streptococcus pneumoniae, an opportunistic pathogen commonly carried asymptomatically in the nasopharynx of children, is associated with increasing rates of treatment failures due to a worldwide increase in drug resistance. We investigated the carriage of S. pneumoniae in children 5 years or younger, the identity of prevalent serotypes, the rates of resistance to macrolides and other antimicrobial agents and the genotypes responsible for macrolide resistance. Materials and Methods: Nasopharyngeal swabs were collected from 157 children under 5 years for cultural isolation of S. pneumoniae. Antibiogram of isolates  was determined using the disk diffusion test, and the minimal inhibitory concentration to macrolides was determined using the E-test. Isolate serotypes and macrolide resistance genes, erm(B and mef(E, were identified using multiplex polymerase chain reactions. Results: S. pneumoniae was recovered from 33.8% of children; 41.9% among males and 21.9% among females (P = 0.009. The highest carriage rate occurred among age groups 7-12 months and 49-60 months. Most frequent serotypes were 19F, 6A/B, 11A, 19A, 14 and 15B/C.  Resistance to macrolides was 60.4%. Resistance to oxacillin, trimethoprim/sulfamethoxazole and clindamycin was present among 90.6%, 54.7% and 32.1% of isolates, respectively. All isolates were susceptible to chloramphenicol, levofloxacin and vancomycin. Isolates resistant to one or more macrolide drugs were more likely to be multidrug resistant. Resistance to clindamycin or oxacillin coexisted with macrolide resistance. Among the erythromycin-resistant isolates, erm(B, mef(E and erm(B and mef(E genes were present at rates of 43.8%, 37.5% and 6.3%, respectively. Erm(B and mef(E were associated with very high level and moderate-to-high level resistance to macrolides, respectively. Conclusion: A significant proportion of children harboured macrolide and multidrug-resistant S. pneumoniae.

  3. Genetic and physiological studies of antibiotic resistance in a clinical isolate of Streptococcus faecalis

    International Nuclear Information System (INIS)

    Sharma, V.K.

    1987-01-01

    An erythromycin-sensitive clinical isolate of Streptococcus faecalis (CS-4B) generated intermediate-level erythromycin-resistant isolates ([CS-4B(S)] at a frequency of 4 x 10 -8 per cell. CS-4B(S) produces high-level erythromycin-resistant isolates [CS-4B(L)] at a very high frequency. The erythromycin-resistance is non-transferable, chromosomally located, and distinct from the well described erythromycin-resistance of the MLS type. The erythromycin-resistance of CS-4B(S) and CS-4B(L) is not due to an in vitro or in vivo alteration or inactivation of erythromycin. 14 C-erythromycin binds in vitro, as evaluated with sucrose gradients, to 70S ribosomes and 50S ribosomal subunits in CS-4B. Binding to CS-4B(L) ribosomes was barely detectable whereas CS-4B(S) ribosomes retained binding capacity. The binding studies on filter membranes revealed a substantial reduction of 14 C-erythromycin binding to CS-4B(S) ribosomes when compared to CS-4B ribosomes. The in vivo accumulation of 14 C-erythromycin in CS-4B and CS-4B(S) parallel the in vitro binding capacity of ribosomes indicating the apparent absence of a permeability barrier to erythromycin in CS-4B

  4. Genetic and physiological studies of antibiotic resistance in a clinical isolate of Streptococcus faecalis

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V.K.

    1987-01-01

    An erythromycin-sensitive clinical isolate of Streptococcus faecalis (CS-4B) generated intermediate-level erythromycin-resistant isolates ((CS-4B(S)) at a frequency of 4 x 10/sup -8/ per cell. CS-4B(S) produces high-level erythromycin-resistant isolates (CS-4B(L)) at a very high frequency. The erythromycin-resistance is non-transferable, chromosomally located, and distinct from the well described erythromycin-resistance of the MLS type. The erythromycin-resistance of CS-4B(S) and CS-4B(L) is not due to an in vitro or in vivo alteration or inactivation of erythromycin. /sup 14/C-erythromycin binds in vitro, as evaluated with sucrose gradients, to 70S ribosomes and 50S ribosomal subunits in CS-4B. Binding to CS-4B(L) ribosomes was barely detectable whereas CS-4B(S) ribosomes retained binding capacity. The binding studies on filter membranes revealed a substantial reduction of /sup 14/C-erythromycin binding to CS-4B(S) ribosomes when compared to CS-4B ribosomes. The in vivo accumulation of /sup 14/C-erythromycin in CS-4B and CS-4B(S) parallel the in vitro binding capacity of ribosomes indicating the apparent absence of a permeability barrier to erythromycin in CS-4B.

  5. Isolation and Pathogenicity of Streptococcus iniae in Cultured Red Hybrid Tilapia in Malaysia.

    Science.gov (United States)

    Rahmatullah, M; Ariff, M; Kahieshesfandiari, M; Daud, H M; Zamri-Saad, M; Sabri, M Y; Amal, M N A; Ina-Salwany, M Y

    2017-12-01

    This study describes the isolation and pathogenicity of Streptococcus iniae in cultured red hybrid tilapia (Nile Tilapia Oreochromis niloticus × Mozambique Tilapia O. mossambicus) in Malaysia. The isolated gram-positive S. iniae appeared punctiform, transparently white, catalase and oxidase negative and produced complete β-hemolysis on blood agar, while a PCR assay resulted in the amplification of the 16 S rRNA gene and lactate oxidase encoded genes. The isolate was sensitive to tetracycline, vancomycin, and bacitracin but was resistant to streptomycin, ampicillin, penicillin, and erythromycin. Pathogenicity trials conducted in local red hybrid tilapia (mean ± SE = 20.00 ± 0.45 g) showed 90.0, 96.7, and 100.0% mortality within 14 d postinfection following intraperitoneal exposure to 10 4 , 10 6 , and 10 8 CFU/mL of the pathogen, respectively. The clinical signs included erratic swimming, lethargy, and inappetance at 6 h postinfection, while mortality was recorded at less than 24 h postinfection in all infected groups. The LD 50-336 h of S. iniae against the red hybrid tilapia was 10 2 CFU/mL. The post mortem examinations revealed congested livers, kidneys, and spleens of the infected fish. This is the first report of S. iniae experimental infection in cultured red hybrid tilapia in Malaysia. Received January 20, 2017; accepted July 16, 2017.

  6. Activity of ceftobiprole against Streptococcus pneumoniae isolates exhibiting high-level resistance to ceftriaxone.

    Science.gov (United States)

    Davies, Todd A; Flamm, Robert K; Lynch, A Simon

    2012-06-01

    Tracking Resistance in the US Today (TRUST) 2008 surveillance data showed that 6% of Streptococcus pneumoniae were non-susceptible to ceftriaxone [minimum inhibitory concentration (MIC) ≥ 2 μg/mL] and that 8% of the ceftriaxone-non-susceptible isolates exhibited high-level resistance (MIC ≥ 8 μg/mL). Here we describe the activity of ceftobiprole against ceftriaxone-resistant isolates and characterise the genotypic traits associated with resistance. Thirty isolates with ceftriaxone MICs ≥ 8 μg/mL were analysed by sequencing of penicillin-binding protein (PBP) and murM genes. Sequencing of pbp1a, pbp2b and pbp2x showed nine PBP patterns, with the most common (n=17) being: PBP1a T371S (STMK motif), P432T (SRNVP motif); PBP2b T446A (SSNT motif), A619G (KTGTA motif); and PBP2x T338A and M339F (STMK motif), L364F, I371T, R384G, M400T, L546V (LKSGT motif); six isolates had the same pattern without the PBP2b A619G change. For these 23 isolates, MICs were 8 μg/mL for ceftriaxone, 4-8 μg/mL for penicillin and 0.5-2 μg/mL for ceftobiprole. The remaining seven isolates with higher MICs (ceftriaxone 8-32 μg/mL, penicillin 4-32 μg/mL and ceftobiprole 2-4 μg/mL) had fewer PBP active-site motif substitutions. The majority of isolates (17/30) had murM alleles similar to the wild-type, whilst the rest had alleles reflecting a mosaic structure. No murM alleles were associated with higher MICs. Against these 30 isolates, ceftobiprole was 4-16-fold more active than ceftriaxone. Widely described PBP and MurM substitutions probably account for the high ceftriaxone MICs (8 μg/mL) in the majority of isolates. However, seven isolates with ceftriaxone MICs of 8-32 μg/mL had fewer PBP substitutions in active-site motifs, suggesting either that there is another resistance mechanism or that unique PBP mutations may contribute to high-level β-lactam resistance. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  7. (garlic) and erythromycin on streptococcus pyogenes abstract

    African Journals Online (AJOL)

    LIVINGSTON

    thrombosis and hypertension , diabetic mellitus ; artherosclerosis inhibition and exhibits broad antibiotic spectrum . It has been suggested that garlic decreases fatigue and improvesmemory . Erythromycin is a macrolide antibiotic, which has antimicrobial spectrum similar to or slightly wider than that of penicillin and is often.

  8. Vaginal isolation of beta-haemolytic Streptococcus from bitches with and without neonatal deaths in the litters.

    Science.gov (United States)

    Guerrero, A E; Stornelli, M C; Jurado, S B; Giacoboni, G; Sguazza, G H; de la Sota, R L; Stornelli, M A

    2018-02-18

    The aim of the study was to identify beta-haemolytic streptococci in the vagina of bitches who had delivered healthy litters and bitches who had delivered litters in which neonatal deaths occurred. Fifty-one bitches divided into two groups were used. Group 1 (G1) included 28 bitches that had delivered healthy litters and group 2 (G2) included 23 bitches that had delivered puppies who died in the neonatal period. Two vaginal samples were taken, one in proestrus and the other at the end of gestation (EG). Beta-haemolytic Streptococcus (BS) was isolated from 16 bitches (57%) in G1 and from 21 bitches (91%) in G2. The bacteriological cultures, serological tests (Streptex ® ) and PCR assay allowed identification of Streptococcus canis and Streptococcus dysgalactiae in G1 and G2. Ultramicroscopic studies allowed the observation of M Protein and capsules in strains of S. dysgalactiae and S. canis in G1 and G2. The S. canis strains isolated from G2 showed thicker capsules than S. canis strains isolated from G1 (234 ± 24.2 vs 151.23 ± 28.93 nm; p  .70). All strains of beta-haemolytic Streptococcus isolated were penicillin sensitive. Penicillin was administered from EG to 5 days post-partum in 10 G2 females with isolation of BS (G2A). Saline solution was administered in eleven G2 females with isolation of BS (G2B). Ninety per cent of the puppies survived in G2A and 25% survived in G2B. Our results suggest BS is involved in canine neonatal deaths. © 2018 Blackwell Verlag GmbH.

  9. Is Penicillin plus Gentamicin Synergistic against Clinical Group B Streptococcus isolates?: A in-vitro Study.

    Directory of Open Access Journals (Sweden)

    Corinne Ruppen

    2016-10-01

    Full Text Available Group B Streptococcus (GBS is increasingly causing invasive infections in nonpregnant adults. Elderly patients and those with comorbidities are at increased risk. On the basis of previous studies focusing on neonatal infections, penicillin plus gentamicin is recommended for infective endocarditis (IE and periprosthetic joint infections (PJI in adults. The purpose of this study was to investigate whether a synergism with penicillin and gentamicin is present in GBS isolates that caused IE and PJI. We used 5 GBS isolates, two clinical strains and three control strains, including one displaying high-level gentamicin resistance (HLGR. The results from the checkerboard and time-kill assays (TKAs were compared. For TKAs, antibiotic concentrations for penicillin were 0.048 and 0.2 mg/L, and for gentamicin 4 mg/L or 12.5 mg/L. In the checkerboard assay, the median fractional inhibitory concentration indices (FICIs of all isolates indicated indifference. TKAs for all isolates failed to demonstrate synergism with penicillin 0.048 or 0.2 mg/L, irrespective of gentamicin concentrations used. Rapid killing was seen with penicillin 0.048 mg/L plus either 4 mg/L or 12.5 mg/L gentamicin, from 2 h up to 8 h hours after antibiotic exposure. TKAs with penicillin 0.2 mg/L decreased the starting inoculum below the limit of quantification within 4 h to 6 h, irrespective of the addition of gentamicin. Fast killing was seen with penicillin 0.2 mg/L plus 12.5 mg/L gentamicin within the first 2 h. Our in vitro results indicate that the addition of gentamicin to penicillin contributes to faster killing at low penicillin concentrations, but only within the first few hours. Twenty-four hours after antibiotic exposure, PEN alone was bactericidal and synergism was not seen.

  10. Antimicrobial resistance and molecular characteristics of Streptococcus agalactiae isolated from women of reproductive age

    Directory of Open Access Journals (Sweden)

    Magdalena Musiorska

    2016-12-01

    Full Text Available Introduction. Streptococcus agalactiae infections are among the most significant causes of neonatal invasive diseases. Proper screening and detection of pregnant women carrying GBS allows intrapartum administration of antibiotic prophylaxis and is an effective measure in preventing transmission of bacteria from mother to newborns. Material and methods. Sixty three bacterial strains were isolated from vaginal swabs from pregnant and nonpregnant women of reproductive age. Species were identified by colony morphology, haemolysis type, Gram staining and SLIDEX® Strepto Plus latex test. Antimicrobial resistance of 56 strains was determined using disk-diffusion method. The presence of molecular resistance determinants was assessed using PCR with specific primers, and capsular types were identified using multiplex PCR. Results. None of the strains were resistant to the first drug of choice, penicillin. A large percentage of isolates (78.6% were resistant to doxycycline. The prevalence of resistance to macrolides and lincosamides, antibiotics used in women allergic to penicillin, was high. Those results corresponded with PCR tests, as tetM and ermA1 were most frequently detected genes (98.4 and 87.3%, respectively. 7.94% of strains possessed 7 different out of 13 tested genes determining resistance to different groups of antimicrobials. Among the capsular types, Ia, which proved to be associated with the most severe and invasive infections in mothers and neonates, was the most prevalent (65.08%. Conclusions. Even though they are susceptible to penicillin, multidrug resistance is common among S. agalactiae strains isolated from women of reproductive age and this resistance can be caused by more than one gene per single isolate

  11. Comparative effects of photodynamic therapy mediated by curcumin on standard and clinical isolate of Streptococcus mutans.

    Science.gov (United States)

    Tonon, Caroline C; Paschoal, Marco Aurélio; Correia, Marilia; Spolidório, Denise M P; Bagnato, Vanderlei S; Giusti, Juçaíra S M; Santos-Pinto, Lourdes

    2015-01-01

    The aim of this study was investigate the effect of photodynamic therapy (PDT) using curcumin (C) as a photosensitizing agent irradiated with an LED (L) in the blue wavelength as a light source on a standard and clinical isolate of Streptococcus mutans (S. mutans) in a planktonic suspension model. Suspensions of both strains were divided into 4 groups as follows: absence of C and L (control group: C-L-), with C and without L (C group: C+L-), absence of C with L (L group: C-L+) and presence of C and L (PDT group: C+L+). Three different concentrations of curcumin (0.75 mg/ml, 1.5 mg/ml and 3 mg/ml) and three light fluences of studied light source (24, 48 and 72 J cm(-2)) were tested. Aliquots of each studied group was plated in BHI agar and submitted to colony forming units counting (CFU/ml) and the data transformed into logarithmical scale. A high photoinactivation rate of more than 70% was verified to standard S. mutans strain submitted to PDT whereas the clinical isolate showed a lower sensitivity to all the associations of curcumin and LED. A slight bacterial reduction was verified to C+L- and C-L+, demonstrating no toxic effects to the isolated application of light and photosensitizer to both S. mutans strains tested. Photodynamic therapy using a combination of curcumin and blue LED presented a substantial antimicrobial effect on S. mutans standard strain in a planktonic suspension model with a less pronounced effect on its clinical isolate counterparts due to resistance to this alternative approach. Alternative antimicrobial approaches, as photodynamic therapy, should be encouraged due to optimal results against cariogenic bacteria aiming to prevent or treat dental caries.

  12. Biotypes and ScM types of isolates of Streptococcus canis from diseased and healthy cats.

    Science.gov (United States)

    Timoney, J F; Velineni, S; Ulrich, B; Blanchard, P

    2017-04-08

    Lancefield group G Streptococcus canis is a component of the normal urogenital and pharyngeal flora of the cat. It is also frequently implicated in epizootics of severe disease in closed cat colonies and animal shelters. Given the importance of S canis as a feline pathogen and relative lack of published information on characteristics potentially associated with virulence, the authors have compared isolates from healthy and diseased cats in New York and California using fermentation profiles (biotype) and ScM sequences. With few exceptions, isolates associated with disease were biotype 1. Four alleles of scm were identified of which type 1 dominated in diseased cats. Type 4 allelic variants were found only in healthy cats and all but one were biotype 2. Type 2 and 3 alleles showed extensive N-terminal variation suggesting a plasminogen-binding site as found on the type 1 allele was absent. Cat antisera to ScM were opsonobactericidal, and these potentially protective antibodies increased during convalescence. British Veterinary Association.

  13. Molecular basis for different levels of tet(M) expression in Streptococcus pneumoniae clinical isolates.

    Science.gov (United States)

    Grohs, Patrick; Trieu-Cuot, Patrick; Podglajen, Isabelle; Grondin, Sophie; Firon, Arnaud; Poyart, Claire; Varon, Emmanuelle; Gutmann, Laurent

    2012-10-01

    Seventy-four unrelated clinical isolates of Streptococcus pneumoniae harboring the tet(M) gene were studied. Seven strains with low tetracycline (Tc) MICs (0.25 to 0.5 μg/ml) were found to harbor truncated tet(M) alleles that were inactivated by different frameshift mutations. In contrast, five strains bore deletions in the tet(M) promoter region, among which four displayed increased Tc MICs (16 to 64 μg/ml). The same promoter mutations were detected in Tc-resistant mutants selected in vitro from various susceptible strains. Sequence analysis revealed that these deletions might impede the formation of the transcriptional attenuator located immediately upstream of tet(M). Expression in Enterococcus faecalis of a tet(M) reporter gene transcribed from these promoter mutants conferred a level of Tc resistance similar to that observed in the parental S. pneumoniae strains. These results show that different levels of Tc susceptibility found in clinical isolates of S. pneumoniae can be explained by frameshift mutations within tet(M) and by alterations of the upstream transcriptional attenuator.

  14. Short communication: Conservation of Streptococcus uberis adhesion molecule and the sua gene in strains of Streptococcus uberis isolated from geographically diverse areas.

    Science.gov (United States)

    Yuan, Ying; Dego, Oudessa Kerro; Chen, Xueyan; Abadin, Eurife; Chan, Shangfeng; Jory, Lauren; Kovacevic, Steven; Almeida, Raul A; Oliver, Stephen P

    2014-12-01

    The objective was to identify and sequence the sua gene (GenBank no. DQ232760; http://www.ncbi.nlm.nih.gov/genbank/) and detect Streptococcus uberis adhesion molecule (SUAM) expression by Western blot using serum from naturally S. uberis-infected cows in strains of S. uberis isolated in milk from cows with mastitis from geographically diverse areas of the world. All strains evaluated yielded a 4.4-kb sua-containing PCR fragment that was subsequently sequenced. Deduced SUAM AA sequences from those S. uberis strains evaluated shared >97% identity. The pepSUAM sequence located at the N terminus of SUAM was >99% identical among strains of S. uberis. Streptococcus uberis adhesion molecule expression was detected in all strains of S. uberis tested. These results suggest that sua is ubiquitous among strains of S. uberis isolated from diverse geographic locations and that SUAM is immunogenic. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. Clonal relationships among penicillin-susceptible, multiresistant serotype 6B Streptococcus pneumoniae isolates recovered in Greece and France.

    Science.gov (United States)

    Syrogiannopoulos, G A; Doit, C; Grivea, I N; Geslin, P; Bingen, E

    2001-01-01

    In January 1996 the emergence of penicillin-susceptible, multiresistant serotype 6B Streptococcus pneumoniae isolates resistant to chloramphenicol, tetracycline, erythromycin, clindamycin and trimethoprim-sulfamethoxazole was observed in young carriers in the city of Patras, located in the southwestern region of Greece. Later, a significant spread of pneumococci with this unusual phenotype was noted in carriers living in various other areas of the country. Using restriction fragment length polymorphism of the ribosomal RNA genes, clonal relationships were found between these Greek strains and serotype 6B penicillin-susceptible, multiresistant pneumococci isolated in France between January 1992 and September 1996. The French and Greek isolates appear to have a common ancestry.

  16. Isolation of Streptococcus equi subsp. equi from thoroughbred horses in a racehorse-breeding area of Japan.

    Science.gov (United States)

    Anzai, T; Nakanishi, A; Wada, R; Higuchi, T; Hagiwara, S; Takazawa, M; Oobayashi, K; Inoue, T

    1997-11-01

    For determination whether strangles has invaded the Hidaka district of Hokkaido, the main racehorse-breeding area of Japan, a epizootiological survey with bacterial isolation was carried out during the breeding season in 1995. Streptococcus equi subsp. equi, which is the causative agent of strangles, was isolated from two Thoroughbred horses with submandibular lymphadenitis. Isolates were identified by serological grouping, biochemical tests and analysis of cell surface proteins by Western immunoblotting. Through this survey, it revealed that S. equi subsp. equi has invaded the Hidaka district and that strangles has become prevalent in racehorse-breeding farms in this area.

  17. Antibiotic sensitivities of Streptococcus pneumoniae, viridans streptococci, and group A hemolytic streptococci isolated from the maxillary and ethmoid sinuses.

    Science.gov (United States)

    Keleş, Erol; Aral, Murat; Alpay, H Cengiz

    2006-01-01

    To investigate antibiotic sensitivities of Streptococcus pneumoniae, viridans streptococci, and group A hemolytic streptococci isolated from the culture materials obtained from the sinuses of patients undergoing functional endoscopic sinus surgery due to chronic sinusitis. We recruited 93 patients (63 males, 30 females; mean age 36+/-17.5; range 19 to 68 years) who underwent functional endoscopic sinus surgery due to chronic sinusitis. Before surgical intervention, in order to eliminate a possible contamination from the skin and neighboring structures, nasal mucosa was cleansed with povidone-iodine solution. Nasal smear samples were obtained from all the patients before and after applying povidone-iodine solution. Streptococcus pneumoniae, viridans streptococci and group A hemolytic streptococci that were isolated from the cultures were tested for antibiotic sensitivity. The number of anaerobic bacteria isolated from 58 patients (62.3%) before applying povidone-iodine was 72, following the application of povidone-iodine a total of 16 microorganisms were identified from 12 patients (12.9%). Microorganisms were isolated from 95.6% (89/93) of the samples obtained from the maxillary sinuses and 91.3% (85/93) of the samples obtained from the ethmoid sinuses. The most commonly identified microorganisms from both sinuses were coagulase negative staphylococcus followed by viridans streptococci, coagulase positive staphylococcus, Streptococcus pneumoniae and group A hemolytic streptococci. For viridans streptococcal strains that were isolated, 33.3% were resistant to tetracycline, 23.8% to chloramphenicol, and 19.04% to penicillin. Hemolytic streptococci strains were sensitive to penicillin, ofloxacin, ceftriaxone, and cefepime in all the groups; however, they had 50% resistance to erythromycin and chloramphenicol and 100% resistance to tetracycline. The resistance pattern of the isolated Streptococcus pneumoniae strains were as follows: 25% to penicillin, 66.6% to

  18. Phenotypic and genotypic characterization of Streptococcus uberis isolated from bovine subclinical mastitis in Argentinean dairy farms

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    Mirta C Lasagno

    2011-09-01

    Full Text Available The aim of this study was to investigate the phenotypic and genotypic characteristics of Streptococcus uberis isolated from subclinical mastitis (SCM cases, and to examine the possible association between both characteristics. A total of 32 S. uberis were isolated from 772 quarter milk samples (SCM > 250,000 cells/ml collected from 195 cows selected randomly from 18 dairy farms located in Argentina. The S. uberis strains were characterized phenotypically by the presence of virulence factors as plasminogen activator factor (PAF, hyaluronidase (HYA, capsule (CAP and CAMP factor, and were further characterized genotypically by pulsed-field gel electrophoresis (PFGE. S. uberis strains expressed plasminogen activator factor, hyaluronidase or capsule (65.5 %, 56.3 %, 59.4 %, respectively, but only 25 % of isolates were CAMP factor positive. Thirteen different virulence profiles were identified on the basis of the combination of virulence factors. Eighteen PFGE patterns with 90% of similarity were identified among 32 S. uberis. A great diversity of virulence profiles and PFGE patterns were present among dairy farms. S. uberis strains with the same PFGE pattern showed different virulence profiles. Bovine S. uberis strains causing SCM included in the present study showed heterogeneity in regard to their phenotypic and genotypic characteristics, and the PFGE patterns are not associated with the virulence profiles.Caracterización fenotípica y genotípica de Streptococcus uberis aislados de mastitis bovina subclínica en tambos de Argentina. El objetivo de este estudio fue investigar las características fenotípicas y genotípicas de Streptococcus uberis aislados de casos de mastitis subclínica (MSC y examinar la posible asociación entre ambas características. Un total de 32 cepas de S. uberis fueron aisladas de 772 muestras de leche de cuartos mamarios (MSC > 25 0000 células/ml colectadas de 195 vacas seleccionadas al azar pertenecientes a 18 tambos

  19. Genetic diversity and virulence genes in Streptococcus uberis strains isolated from bovine mastitis

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    Rafael Ambrósio Loures

    2017-08-01

    Full Text Available Mastitis is one of the most common and costly infectious diseases in dairy cattle worldwide. This is a multifactorial illness caused by different microorganisms, including virus, yeasts, algae, parasites, and several species of bacteria. Among these bacteria, Streptococcus uberis is an important environmental pathogen that is responsible for a large range of clinical and subclinical mammary infections, especially in intensively managed herds. Despite the increasing importance of this pathogen in the etiology of bovine mastitis, data on its virulence and diversity in Brazilian dairy herds are scarce. The aims of the present study were to investigate the virulence characteristics of S. uberis isolated from bovine mastitis and to assess the molecular epidemiology of the Brazilian isolates using pulsed-field gel electrophoresis (PFGE. In this work, 46 strains of S. uberis isolated from bovine mastitis from 26 Brazilian dairy herds were evaluated regarding their genetic diversity by PFGE using with the SmaI enzyme. Additionally, the presence of the virulence genes skc and pauA, which encode plasminogen activators, and the gene sua, which encodes an adhesion molecule in mammary epithelial cells, were assessed by PCR. Our results showed a high genetic diversity in the population, displaying many different patterns in the PFGE analysis. A high proportion of strains was positive for virulence genes in the sampled population (sua [100%], pauA [91%], and skc [91%]. The high frequency of skc, pauA, and sua genes among the studied strains suggests the importance of these virulence factors, possibly helping S. uberis in the colonization of the bovine mammary gland. Surveys of the genetic and molecular characteristics of this pathogen can improve our knowledge of bacterial activity and identify molecules that have roles in the establishment of the infection. This might help in the development of more effective measures to control and prevent bovine mastitis.

  20. Variable characteristics of bacteriocin-producing Streptococcus salivarius strains isolated from Malaysian subjects.

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    Abdelahhad Barbour

    Full Text Available BACKGROUND: Salivaricins are bacteriocins produced by Streptococcus salivarius, some strains of which can have significant probiotic effects. S. salivarius strains were isolated from Malaysian subjects showing variable antimicrobial activity, metabolic profile, antibiotic susceptibility and lantibiotic production. METHODOLOGY/PRINCIPAL FINDINGS: In this study we report new S. salivarius strains isolated from Malaysian subjects with potential as probiotics. Safety assessment of these strains included their antibiotic susceptibility and metabolic profiles. Genome sequencing using Illumina's MiSeq system was performed for both strains NU10 and YU10 and demonstrating the absence of any known streptococcal virulence determinants indicating that these strains are safe for subsequent use as probiotics. Strain NU10 was found to harbour genes encoding salivaricins A and 9 while strain YU10 was shown to harbour genes encoding salivaricins A3, G32, streptin and slnA1 lantibiotic-like protein. Strain GT2 was shown to harbour genes encoding a large non-lantibiotic bacteriocin (salivaricin-MPS. A new medium for maximum biomass production buffered with 2-(N-morpholinoethanesulfonic acid (MES was developed and showed better biomass accumulation compared with other commercial media. Furthermore, we extracted and purified salivaricin 9 (by strain NU10 and salivaricin G32 (by strain YU10 from S. salivarius cells grown aerobically in this medium. In addition to bacteriocin production, S. salivarius strains produced levan-sucrase which was detected by a specific ESI-LC-MS/MS method which indicates additional health benefits from the developed strains. CONCLUSION: The current study established the bacteriocin, levan-sucrase production and basic safety features of S. salivarius strains isolated from healthy Malaysian subjects demonstrating their potential for use as probiotics. A new bacteriocin-production medium was developed with potential scale up application for

  1. The molecular identification of Streptococcus equi subsp. equi strains isolated within New Zealand.

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    Patty, O A; Cursons, R T M

    2014-03-01

    To identify Streptococcus equi subsp. equi (S. equi) by PCR analysis and obtain isolates by culture, in order to investigate the strains of S. equi infecting horses within New Zealand. A diagnostic PCR, based on the amplification of the seeI gene for S. equi, was used on 168 samples submitted from horses with and without clinical signs of strangles. Samples were also processed and cultured on selective media for the isolation of β-haemolytic colonies. In addition, the hypervariable region of the seM gene of S. equi was amplified and then sequenced for strain typing purposes. Of the 168 samples, 35 tested positive for S. equi using PCR. Thirty-two confirmed samples were from horses with a clinical diagnosis of strangles and three were from horses where clinical information was unavailable. Only 22/35 (63%) confirmed S. equi samples were successfully isolated following culture. Strain typing demonstrated that two novel seM alleles of S. equi were found in New Zealand with SeM-99 strains being restricted to the North Island while SeM-100 strains were found in both North and South Islands. The application of PCR for the laboratory confirmation of strangles allowed for a rapid and sensitive identification of S. equi. Moreover, seM typing revealed that within the samples examined two strains of S. equi co-circulated within the North Island of New Zealand but only one strain in the South Island. PCR reduces the time required to obtain laboratory confirmation of strangles compared with culture methods. It also has greater sensitivity in detecting S. equi infections, which is of particular importance in the detection of carrier animals which normally shed low numbers of bacteria. Additionally, seM molecular typing can differentiate between bacterial strains, assisting in the monitoring of local strains of S. equi subsp. equi causing disease.

  2. Using selective chromogenic plates to optimize isolation of group B Streptococcus in pregnant women

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    Romano Mattei

    2014-03-01

    Full Text Available Group B Streptococcus (GBS remains the leading cause of severe bacterial infections (sepsis, meningitis, pneumonia in neonates. We compared the detection of GBS from recto-vaginal swabs on blood agar and two chromogenic media and evaluated their antibiotic susceptibility. A total of 1351 swabs were taken from pregnant women at 35-37 weeks of gestation. Following enrichment in Todd Hewitt broth + nalidixic acid and colistin, the samples were plated on Columbia CNA agar (CNA, chromID Strepto B agar (STRB and Granada Agar (GRAN, respectively. GBS were found in 22.4% of recto-vaginal swabs from pregnant women. Sensitivity, specificity, positive and negative predictive values of GBS detection were 88%, 88%, 81% and 96% for CNA, 99%, 97%, 90% and 99% for STRB and 94%, 99%, 98% e 99% for GRAN; Cohen’s k index concordances for CNA, STREB and GRAN were 0.68, 0.92 and 0.96, respectively. All isolates were susceptible to penicillin, whereas resistances of erythromycin and clindamycin were 40% and 42%, respectively. To conclude, selective broth enrichment combined with chromogenic plates is recommended for GBS screening in pregnant women.

  3. [Antimicrobial susceptibility in isolates of Streptococcus equi subsp. equi from Buenos Aires province, Argentina].

    Science.gov (United States)

    Bustos, Carla P; Marfil, María J; Lanza, Natalia S; Guida, Nora

    2017-11-30

    Streptococcus equi subsp. equi is the etiologic agent of strangles, an infectious disease affecting the upper respiratory tract and head and neck lymph nodes of equines. Routine antimicrobial therapy includes penicillin (PEN) as antibiotic of first choice. Streptococci are usually susceptible to PEN and only a few antimicrobial studies had been performed. The aim of this work was to study the antimicrobial susceptibility profile of S. equi from Buenos Aires, Argentina. Ninety-two isolates were studied by the single disk method to PEN, cefotaxime, erythromycin (ERY), tetracycline, enrofloxacin (ENR), trimethoprim sulfamethoxazole (TMS), ciprofloxacin, clindamycin (CLI), streptomycin (STR) and florfenicol. Minimum inhibitory concentration (MIC) to PEN and antibiotics with resistance and intermediate susceptibility were tested. High percentages of susceptibility were obtained by the disk diffusion method and MIC values of PEN, TMS and CLI were found to be under the breakpoint values. Resistant strains of ENR and STR with MIC 50 , MIC 90 and MIC ranges above breakpoints were identified. These findings confirm that PEN may be used empirically because resistant strains were not found in Buenos Aires. Emphasis is placed on the rational use of antibiotics to achieve therapeutic success, to prevent chronicity, recurrence of infections and the emergence of resistance. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Genotypic Characterization of Streptococcus infantarius subsp. coli Isolates from Sea Otters with Infective Endocarditis and/or Septicemia and from Environmental Mussel Samples

    Science.gov (United States)

    Counihan-Edgar, Katrina L.; Gill, Verena A.; Doroff, Angela M.; Burek, Kathleen A.; Miller, Woutrina A.; Shewmaker, Patricia L.; Jang, Spencer; Goertz, Caroline E. C.; Tuomi, Pamela A.; Miller, Melissa A.; Jessup, David A.

    2012-01-01

    Pulsed-field gel electrophoresis (PFGE) was used to type 128 Streptococcus infantarius subsp. coli isolates from sea otters and mussels. Six SmaI PFGE groups were detected, with one predominant group representing 57% of the isolates collected over a wide geographic region. Several sea otter and mussel isolates were highly related, suggesting that an environmental infection source is possible. PMID:23052307

  5. Isolation of a tannic acid-degrading Streptococcus sp. from an anaerobic shea cake digester.

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    Nitiema, L W; Dianou, D; Simpore, J; Karou, S D; Savadogo, P W; Traore, A S

    2010-01-01

    An anaerobic digester fed with shea cake rich in tannins and phenolic compounds rich-shea cake and previously inoculated with anaerobic sludge from the pit of a slaughterhouse, enabled six months acclimatization of the bacteria to aromatic compounds. Afterwards, digester waste water samples were subject to successive culture on media with 1 g L(-1) tannic acid allowing the isolation of a bacterial strain coded AB. Strain AB was facultatively anaerobic, mesophilic, non-motile, non-sporulating, catalase and oxidase negative bacterium, namely strain AB, was isolated from an anaerobic digester fed with shea cake rich in tannins and phenolic compounds, after inoculation with anaerobic sludge from the pit of a slaughterhouse and enrichment on tannic acid. The coccoid cells occurred in pair, short or long chains and stained Gram-positive. Strain AB fermented a wide range of carbohydrates including glucose, fructose, galactose, raffinose, arabinose, sucrose, maltose, lactose, starch and cellulose. Optimum growth occurred with glucose and tannic acid at 37 degrees C and pH 8. The pH, temperature and salt concentration for growth ranged from 5 to 9, 20 to 45 degrees C and 0 to 15 g L(-1), respectively. Strain AB converted tannic acid to gallic acid. These features were similar to those of the Streptococcus genus. The determination of tannic acid hydrolysis end products, ability to utilize various organic acids, alcohols and peptides, GC% of the DNA, the sequencing of 16S rRNA gene and DNA-DNA hybridization will permit to confirm this affiliation and to determine the species.

  6. Identification of Escherichia coli and Trueperella pyogenes isolated from the uterus of dairy cows using routine bacteriological testing and Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Jaureguiberry, María; Madoz, Laura Vanina; Giuliodori, Mauricio Javier; Wagener, Karen; Prunner, Isabella; Grunert, Tom; Ehling-Schulz, Monika; Drillich, Marc; de la Sota, Rodolfo Luzbel

    2016-11-28

    Uterine disorders are common postpartum diseases in dairy cows. In practice, uterine treatment is often based on systemic or locally applied antimicrobials with no previous identification of pathogens. Accurate on-farm diagnostics are not available, and routine testing is time-consuming and cost intensive. An accurate method that could simplify the identification of uterine pathogenic bacteria and improve pathogen-specific treatments could be an important advance to practitioners. The objective of the present study was to evaluate whether a database built with uterine bacteria from European dairy cows could be used to identify bacteria from Argentinean cows by Fourier transformed infrared (FTIR) spectroscopy. Uterine samples from 64 multiparous dairy cows with different types of vaginal discharge (VD) were collected between 5 and 60 days postpartum, analyzed by routine bacteriological testing methods and then re-evaluated by FTIR spectroscopy (n = 27). FTIR spectroscopy identified Escherichia coli in 12 out of 14 samples and Trueperella pyogenes in 8 out of 10 samples. The agreement between the two methods was good with a Kappa coefficient of 0.73. In addition, the likelihood for bacterial growth of common uterine pathogens such as E. coli and T. pyogenes tended to increase with VD score. The odds for a positive result to E. coli or T. pyogenes was 1.88 times higher in cows with fetid VD than in herdmates with clear normal VD. We conclude that the presence of E. coli and T. pyogenes in uterine samples from Argentinean dairy cows can be detected with FTIR with the use of a database built with uterine bacteria from European dairy cows. Future studies are needed to determine if FTIR can be used as an alternative to routine bacteriological testing methods.

  7. Suicin 3908, a new lantibiotic produced by a strain of Streptococcus suis serotype 2 isolated from a healthy carrier pig.

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    Katy Vaillancourt

    Full Text Available While Streptococcus suis serotype 2 is known to cause severe infections in pigs, it can also be isolated from the tonsils of healthy animals that do not develop infections. We hypothesized that S. suis strains in healthy carrier pigs may have the ability to produce bacteriocins, which may contribute to preventing infections by pathogenic S. suis strains. Two of ten S. suis serotype 2 strains isolated from healthy carrier pigs exhibited antibacterial activity against pathogenic S. suis isolates. The bacteriocin produced by S. suis 3908 was purified to homogeneity using a three-step procedure: ammonium sulfate precipitation, cationic exchange HPLC, and reversed-phase HPLC. The bacteriocin, called suicin 3908, had a low molecular mass; was resistant to heat, pH, and protease treatments; and possessed membrane permeabilization activity. Additive effects were obtained when suicin 3908 was used in combination with penicillin G or amoxicillin. The amino acid sequence of suicin 3908 suggested that it is lantibiotic-related and made it possible to identify a bacteriocin locus in the genome of S. suis D12. The putative gene cluster involved in suicin production by S. suis 3908 was amplified by PCR, and the sequence analysis revealed the presence of nine open reading frames (ORFs, including the structural gene and those required for the modification of amino acids, export, regulation, and immunity. Suicin 3908, which is encoded by the suiA gene, exhibited approximately 50% identity with bovicin HJ50 (Streptococcus bovis, thermophilin 1277 (Streptococcus thermophilus, and macedovicin (Streptococcus macedonicus. Given that S. suis 3908 cannot cause infections in animal models, that it is susceptible to conventional antibiotics, and that it produces a bacteriocin with antibacterial activity against all pathogenic S. suis strains tested, it could potentially be used to prevent infections and to reduce antibiotic use by the swine industry.

  8. Primary pyogenic spondylitis following kyphoplasty: a case report

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    Heyse Thomas J

    2011-03-01

    Full Text Available Abstract Introduction Only ten cases of primary pyogenic spondylitis following vertebroplasty have been reported in the literature. To the best of our knowledge, we present the first reported case of primary pyogenic spondylitis and spondylodiscitis caused by kyphoplasty. Case presentation A 72-year old Caucasian man with an osteoporotic compression fracture of the first lumbar vertebra after kyphoplasty developed sensory incomplete paraplegia below the first lumbar vertebra. This was caused by myelon compression following pyogenic spondylitis with a psoas abscess. Computed tomography guided aspiration of the abscess cavity yielded group C Streptococcus. The psoas abscess was percutaneously drained and laminectomy and posterior instrumentation with an internal fixator from the eleventh thoracic vertebra to the fourth lumbar vertebra was performed. In a second operation, corpectomy of the first lumbar vertebra with cement removal and fusion from the twelfth thoracic vertebra to the second lumbar vertebra with a titanium cage was performed. Six weeks postoperatively, the patient was pain free with no neurologic deficits or signs of infection. Conclusion Pyogenic spondylitis is an extremely rare complication after kyphoplasty. When these patients develop recurrent back pain postoperatively, the diagnosis of pyogenic spondylitis must be considered.

  9. TetAB46, a predicted heterodimeric ABC transporter conferring tetracycline resistance in Streptococcus australis isolated from the oral cavity.

    Science.gov (United States)

    Warburton, Philip J; Ciric, Lena; Lerner, Avigdor; Seville, Lorna A; Roberts, Adam P; Mullany, Peter; Allan, Elaine

    2013-01-01

    To identify the genes responsible for tetracycline resistance in a strain of Streptococcus australis isolated from pooled saliva from healthy volunteers in France. S. australis is a viridans Streptococcus, originally isolated from the oral cavity of children in Australia, and subsequently reported in the lungs of cystic fibrosis patients and as a cause of invasive disease in an elderly patient. Agar containing 2 mg/L tetracycline was used for the isolation of tetracycline-resistant organisms. A genomic library in Escherichia coli was used to isolate the tetracycline resistance determinant. In-frame deletions and chromosomal repair were used to confirm function. Antibiotic susceptibility was determined by agar dilution and disc diffusion assay. The tetracycline resistance determinant from S. australis FRStet12 was isolated from a genomic library in E. coli and DNA sequencing showed two open reading frames predicted to encode proteins with similarity to multidrug resistance-type ABC transporters. Both genes were required for tetracycline resistance (to both the naturally occurring and semi-synthetic tetracyclines) and they were designated tetAB(46). This is the first report of a predicted ABC transporter conferring tetracycline resistance in a member of the oral microbiota.

  10. Pyogenic abscess (image)

    Science.gov (United States)

    ... become infected. The most common infecting bacteria include E coli , enterococcus, staphylococcus, and streptococcus. Treatment is usually a combination of drainage and prolonged antibiotic therapy.

  11. Isolation of a coaggregation-inhibiting cell wall polysaccharide from Streptococcus sanguis H1.

    OpenAIRE

    Cassels, F J; London, J

    1989-01-01

    Coaggregation between Streptococcus sanguis H1 and Capnocytophaga ochracea ATCC 33596 cells is mediated by a carbohydrate receptor on the former and an adhesin on the latter. Two methods were used to release the carbohydrate receptor from the gram-positive streptococcus, autoclaving and mutanolysin treatment. The polysaccharide released from the streptococcal cell wall by either treatment was purified by ion-exchange chromatography; this polysaccharide inhibited coaggregation when preincubate...

  12. Novel variant serotype of streptococcus suis isolated from piglets with meningitis.

    Science.gov (United States)

    Pan, Zihao; Ma, Jiale; Dong, Wenyang; Song, Wenchao; Wang, Kaicheng; Lu, Chengping; Yao, Huochun

    2015-02-01

    Streptococcus suis is an emerging zoonotic pathogen causing severe infections in pigs and humans. In previous studies, 33 serotypes of S. suis have been identified using serum agglutination. Here, we describe a novel S. suis strain, CZ130302, isolated from an outbreak of acute piglet meningitis in eastern China. Strong pathogenicity of meningitis caused by strain CZ130302 was reproduced in the BALB/c mouse model. The strain showed a high fatality rate (8/10), higher than those for known virulent serotype 2 strains P1/7 (1/10) and 9801 (2/10). Cell adhesion assay results with bEnd.3 and HEp2 cells showed that CZ130302 was significantly close to P1/7 and 9801. Both the agglutination test and its complementary test showed that strain CZ130302 had no strong cross-reaction with the other 33 S. suis serotypes. The multiplex PCR assays revealed no specified bands for all four sets used to detect the other 33 serotypes. In addition, genetic analysis of the whole cps gene clusters of all serotypes was performed in this study. The results of comparative genomics showed that the cps gene cluster of CZ130302, which was not previously reported, showed no homology to the gene sequences of the other strains. Especially, the wzy, wzx, and acetyltransferase genes of strain CZ130302 are phylogenetically distinct from strains of the other 33 serotypes. Therefore, this study suggested that strain CZ130302 represents a novel variant serotype of S. suis (designated serotype Chz) which has a high potential to be virulent and associated with meningitis in animals. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. Prevalence of Group A beta-haemolytic Streptococcus isolated from children with acute pharyngotonsillitis in Aden, Yemen.

    Science.gov (United States)

    Ba-Saddik, I A; Munibari, A A; Alhilali, A M; Ismail, S M; Murshed, F M; Coulter, J B S; Cuevas, L E; Hart, C A; Brabin, B J; Parry, C M

    2014-04-01

    To estimate the prevalence of Group A beta-haemolytic streptococcus (GAS) and non-GAS infections among children with acute pharyngotonsillitis in Aden, Yemen, to evaluate the value of a rapid diagnostic test and the McIsaac score for patient management in this setting and to determine the occurrence of emm genotypes among a subset of GAS isolated from children with acute pharyngotonsillitis and a history of acute rheumatic fever (ARF) or rheumatic heart disease (RHD). Group A beta-haemolytic streptococcus infections in school-aged children with acute pharyngotonsillitis in Aden, Yemen, were diagnosed by a rapid GAS antigen detection test (RADT) and/or GAS culture from a throat swab. The RADT value and the McIsaac screening score for patient management were evaluated. The emm genotype of a subset of GAS isolates was determined. Group A beta-haemolytic streptococcus pharyngotonsillitis was diagnosed in 287/691 (41.5%; 95% CI 37.8-45.3) children. Group B, Group C and Group G beta-haemolytic streptococci were isolated from 4.3% children. The RADT had a sensitivity of 238/258 (92.2%) and specificity of 404/423 (95.5%) against GAS culture. A McIsaac score of ≥4 had a sensitivity of 93% and a specificity of 82% for confirmed GAS infection. The emm genotypes in 21 GAS isolates from children with pharyngitis and a history of ARF and confirmed RHD were emm87 (11), emm12 (6), emm28 (3) and emm5 (1). This study demonstrates a very high prevalence of GAS infections in Yemeni children and the value of the RADT and the McIsaac score in this setting. More extensive emm genotyping is necessary to understand the local epidemiology of circulating strains. © 2014 John Wiley & Sons Ltd.

  14. Lysogenic Streptococcus suis isolate SS2-4 containing prophage SMP showed increased mortality in zebra fish compared to the wild-type isolate.

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    Fang Tang

    Full Text Available Streptococcus suis (S. suis infection is considered to be a major problem in the swine industry worldwide. Based on the capsular type, 33 serotypes of S. suis have been described, with serotype 2 (SS2 being the most frequently isolated from diseased piglets. Little is known, however, about the pathogenesis and virulence factors of S. suis. Research on bacteriophages highlights a new area in S. suis research. A S. suis serotype 2 bacteriophage, designated SMP, has been previously isolated in our laboratory. Here, we selected a lysogenic isolate in which the SMP phage was integrated into the chromosome of strain SS2-4. Compared to the wild-type isolate, the lysogenic strain showed increased mortality in zebra fish. Moreover the sensitivity of the lysogenic strain to lysozyme was seven times higher than that of the wild-type.

  15. Relatedness of Streptococcus equi subsp. zooepidemicus strains