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

PubMed

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

2016-11-01

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

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

PubMed

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.

Status of research and development of vaccines for Streptococcus pyogenes.

PubMed

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

2016-06-03

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.

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry identification of large colony beta-hemolytic streptococci containing Lancefield groups A, C, and G.

PubMed

Jensen, Christian Salgård; Dam-Nielsen, Casper; Arpi, Magnus

2015-08-01

The aim of this study was to investigate whether large colony beta-hemolytic streptococci containing Lancefield groups A, C, and G can be adequately identified using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-ToF). Previous studies show varying results, with an identification rate from below 50% to 100%. Large colony beta-hemolytic streptococci containing Lancefield groups A, C, and G isolated from blood cultures between January 1, 2007 and May 1, 2012 were included in the study. Isolates were identified to the species level using a combination of phenotypic characteristics and 16s rRNA sequencing. The isolates were subjected to MALDI-ToF analysis. We used a two-stage approach starting with the direct method. If no valid result was obtained we proceeded to an extraction protocol. Scores above 2 were considered valid identification at the species level. A total of 97 Streptococcus pyogenes, 133 Streptococcus dysgalactiae, and 2 Streptococcus canis isolates were tested; 94%, 66%, and 100% of S. pyogenes, S. dysgalactiae, and S. canis, respectively, were correctly identified by MALDI-ToF. In most instances when the isolates were not identified by MALDI-ToF this was because MALDI-ToF was unable to differentiate between S. pyogenes and S. dysgalactiae. By removing two S. pyogenes reference spectra from the MALDI-ToF database the proportion of correctly identified isolates increased to 96% overall. MALDI-ToF is a promising method for discriminating between S. dysgalactiae, S. canis, and S. equi, although more strains need to be tested to clarify this.

Detection of Streptococcus pyogenes using rapid visual molecular assay.

PubMed

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

2015-09-01

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

[Significance of group A streptococcal infections in human pathology].

PubMed

Cvjetković, Dejan; Jovanović, Jovana; Hrnjaković-Cvjetković, Ivana; Aleksić-Dordević, Mirjana; Stefan-Mikić, Sandra

2008-01-01

Group A streptococci is the causative agent in 80 percents of human streptococcal infections. The only member of this group is Streptococcus pyogenes. CLINICALFEATURES OF GAS INFECTIONS: The various clinical entities and related complications caused by pyogenic streptococci are reviewed in the article. Pharyngitis, scarlet fever, skin and soft tissue infections (pyoderma, cellulitis, perianal dermatitis, necrotising fasciitis) and streptococcal toxic shock syndrome are described. The way of setting the diagnosis including epidemiological data, clinical features and the course of illness, laboratory findings and supportive diagnostic methods are represented in the article. The most important clinical entities which should be discussed in differential diagnosis of diseases caused by pyogenic streptococci are listed. The major principles of etiologic treatment through widely accepted strategies related to first choice antibiotics and alternatives are reviewed.

Acanthamoeba castellanii interactions with Streptococcus pneumoniae and Streptococcus pyogenes.

PubMed

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.

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

PubMed

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. 

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

PubMed

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.

The novel conjugative transposon tn1207.3 carries the macrolide efflux gene mef(A) in Streptococcus pyogenes.

PubMed

Santagati, Maria; Iannelli, Francesco; Cascone, Carmela; Campanile, Floriana; Oggioni, Marco R; Stefani, Stefania; Pozzi, Gianni

2003-01-01

The macrolide efflux gene mef(A) of the Streptococcus pyogenes clinical strain 2812A was found to be carried by a 52-kb chromosomal genetic element that could be transferred by conjugation to the chromosome of other streptococcal species. The characteristics of this genetic element are typical of conjugative transposons and was named Tn1207.3. The size of Tn1207.3 was established by pulsed-field gel electrophoresis (PFGE), and DNA sequencing analysis showed that the 7,244 bp at the left end of Tn1207.3 were identical to those of the pneumococcal Tn1207.1 element. Tn1207.3-like genetic elements were found to be inserted at a single specific chromosomal site in 12 different clinical isolates S. pyogenes exhibiting the M phenotype of resistance to macrolides and carrying the mef(A) gene. Tn1207.3 was transferred from S. pyogenes 2812A to Streptococcus pneumoniae, and sequence analysis carried out on six independent transconjugants showed that insertion of Tn1207.3 in the pneumococcal genome always occurred at a single specific site as in Tn1207.1. Using MF2, a representative S. pneumoniae transconjugant, as a donor, Tn1207.3 was transferred again by conjugation to S. pyogenes and Streptococcus gordonii. The previously described nonconjugative element Tn1207.1 of S. pneumoniae appears to be a defective element, part of a longer conjugative transposon that carries mef(A) and is found in clinical isolates of S. pyogenes.

Streptococcus pyogenes translocates across an epithelial barrier.

PubMed

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.

CNS autoimmune disease after Streptococcus pyogenes infections: animal models, cellular mechanisms and genetic factors

PubMed Central

Cutforth, Tyler; DeMille, Mellissa MC; Agalliu, Ilir; Agalliu, Dritan

2016-01-01

Streptococcus pyogenes infections have been associated with two autoimmune diseases of the CNS: Sydenham’s chorea (SC) and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus infections (PANDAS). Despite the high frequency of pharyngeal streptococcus infections among children, only a small fraction develops SC or PANDAS. This suggests that several factors in combination are necessary to trigger autoimmune complications: specific S. pyogenes strains that induce a strong immune response toward the host nervous system; genetic susceptibility that predispose children toward an autoimmune response involving movement or tic symptoms; and multiple infections of the throat or tonsils that lead to a robust Th17 cellular and humoral immune response when untreated. In this review, we summarize the evidence for each factor and propose that all must be met for the requisite neurovascular pathology and behavioral deficits found in SC/PANDAS. PMID:27110222

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

PubMed

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.

Selection and characterization, application of a DNA aptamer targeted to Streptococcus pyogenes in cooked chicken.

PubMed

Huang, Yukun; Wang, Xin; Duan, Nuo; Xia, Yu; Wang, Zhouping; Che, Zhenming; Wang, Lijun; Yang, Xiao; Chen, Xianggui

2018-06-15

An aptamer against Streptococcus pyogenes was selected and identified, and a fluorescent method based on the reported aptamer was established to detect S. pyogenes in the cooked chicken. Through a twelve rounds of whole-bacterium SELEX (systematic evolution of ligands by exponential enrichment) selection in vitro, a set of aptamers binding to the whole cell of S. pyogenes were generated, harvesting a low-level dissociation constant (K d ) value of 44 ± 5 nmol L -1 of aptamer S-12. Aptamer-based quantification of S. pyogenes in the cooked chicken sample was implemented in a fluorescence resonance energy transfer-based assay by using graphene oxide, resulting in a limit of detection of 70 cfu mL -1 . The selected aptamer showed affinity and selectivity recognizing S. pyogenes; besides, more biosensors based on the selected aptamer as a molecular recognition element could be developed in the innovative determinations of S. pyogenes. Copyright © 2018 Elsevier Inc. All rights reserved.

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

PubMed Central

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

2014-01-01

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

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

PubMed

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

2015-10-01

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

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

PubMed Central

Nguyen, Scott V.; McShan, William M.

2014-01-01

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

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

PubMed

Nguyen, Scott V; McShan, William M

2014-01-01

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

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

PubMed

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.

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

PubMed

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

2012-11-01

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

Streptococcus penaeicida sp. nov., isolated from a diseased farmed Pacific white shrimp (Penaeus vannamei).

PubMed

Morales-Covarrubias, Maria Soledad; Del Carmen Bolan-Mejía, María; Vela Alonso, Ana Isabel; Fernandez-Garayzabal, Jose F; Gomez-Gil, Bruno

2018-05-01

Strain CAIM 1838 T , isolated from the hepatopancreas of a cultured diseased Pacific white shrimp (Penaeus vannamei), was subjected to characterization by a polyphasic taxonomic approach. On the basis of 16S rRNA gene sequence analysis, strain CAIM 1838 T was most closely related to Streptococcus bovimastitidis 99.3 % and to other species of the Pyogenes clade of Streptococcus with lower similarity values. Average nucleotide identity values and the genome-to-genome distance of strain CAIM 1838 T , as compared with the type strains, confirmed the separate species status with closely related species of the genus Streptococcus and were all below the thresholds to delimit a species, 93.1 and 49.4 %, respectively. The DNA G+C content was 38.1 mol%. Differential phylogenetic distinctiveness together with phenotypic properties obtained in this study revealed that strain CAIM 1838 T could be differentiated from the closely related species. Based on these results it is proposed that strain CAIM 1838 T represents a novel species in the genus Streptococcus, for which the name Streptococcus penaeicida sp. nov is proposed (type strain, CAIM 1838 T =CECT 8596 T ,=DSM26545 T ), is proposed.

Streptococcus anginosus infections: crossing tissue planes.

PubMed

Sunwoo, Bernie Y; Miller, Wallace T

2014-10-01

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

A Rare Cause of Endocarditis: Streptococcus pyogenes

PubMed Central

Yeşilkaya, Ayşegül; Azap, Özlem Kurt; Pirat, Bahar; Gültekin, Bahadır; Arslan, Hande

2012-01-01

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

A Rare Cause of Endocarditis: Streptococcus pyogenes.

PubMed

Yeşilkaya, Ayşegül; Azap, Ozlem Kurt; Pirat, Bahar; Gültekin, Bahadır; Arslan, Hande

2012-09-01

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

Evolution of the core and pan-genome of Streptococcus: positive selection, recombination, and genome composition

PubMed Central

Lefébure, Tristan; Stanhope, Michael J

2007-01-01

Background The genus Streptococcus is one of the most diverse and important human and agricultural pathogens. This study employs comparative evolutionary analyses of 26 Streptococcus genomes to yield an improved understanding of the relative roles of recombination and positive selection in pathogen adaptation to their hosts. Results Streptococcus genomes exhibit extreme levels of evolutionary plasticity, with high levels of gene gain and loss during species and strain evolution. S. agalactiae has a large pan-genome, with little recombination in its core-genome, while S. pyogenes has a smaller pan-genome and much more recombination of its core-genome, perhaps reflecting the greater habitat, and gene pool, diversity for S. agalactiae compared to S. pyogenes. Core-genome recombination was evident in all lineages (18% to 37% of the core-genome judged to be recombinant), while positive selection was mainly observed during species differentiation (from 11% to 34% of the core-genome). Positive selection pressure was unevenly distributed across lineages and biochemical main role categories. S. suis was the lineage with the greatest level of positive selection pressure, the largest number of unique loci selected, and the largest amount of gene gain and loss. Conclusion Recombination is an important evolutionary force in shaping Streptococcus genomes, not only in the acquisition of significant portions of the genome as lineage specific loci, but also in facilitating rapid evolution of the core-genome. Positive selection, although undoubtedly a slower process, has nonetheless played an important role in adaptation of the core-genome of different Streptococcus species to different hosts. PMID:17475002

The role of coagulation/fibrinolysis during Streptococcus pyogenes infection

PubMed Central

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

2014-01-01

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

The role of coagulation/fibrinolysis during Streptococcus pyogenes infection.

PubMed

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

2014-01-01

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

Myosin: A Link between Streptococci and Heart

NASA Astrophysics Data System (ADS)

Krisher, Karen; Cunningham, Madeleine W.

1985-01-01

Murine monoclonal antibodies to Streptococcus pyogenes reacted with skeletal muscle myosin. High molecular weight proteins in extracts of human heart tissue that reacted with an antibody to S. pyogenes also reacted with a monoclonal antibody to ventricular myosin. Adsorption of the antibody to streptococci with S. pyogenes simultaneously removed reactivity of the antibody for either S. pyogenes or myosin. These results indicate that myosin shares immunodeterminants with a component of S. pyogenes.

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

PubMed Central

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

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

PubMed

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

2016-11-03

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.

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

PubMed Central

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

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

PubMed

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.

Pyogenic liver abscess presenting after malignant polypectomy.

PubMed

Harnik, Ian G

2007-12-01

Streptococcus bovis bacteremia has been linked to the presence of occult colon cancer since 1977. We present a case of pyogenic liver abscess and bacteremia with a different Streptococcus viridans 1 week after colonic adenocarcinoma was removed via polypectomy, discuss the likely etiology and review whether there is evidence to support looking for colon cancer in patients who present similarly but have not already undergone screening.

Draft Genome Sequences of Two Streptococcus pyogenes Strains Involved in Abnormal Sharp Raised Scarlet Fever in China, 2011

PubMed Central

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

2012-01-01

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

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

PubMed Central

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

2015-01-01

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

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

PubMed Central

Winterhoff, Nora; Goethe, Ralph; Gruening, Petra; Rohde, Manfred; Kalisz, Henryk; Smith, Hilde E.; Valentin-Weigand, Peter

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 induced expression of two cell wall-associated proteins with apparent molecular masses of approximately 47 and 53 kDa. Amino-terminal sequence analysis of the two proteins indicated homologies of the 47-kDa protein with an ornithine carbamoyltransferase (OCT) from Streptococcus pyogenes and of the 53-kDa protein with the streptococcal acid glycoprotein (SAGP) from S. pyogenes, an arginine deiminase (AD) recently proposed as a putative virulence factor. Cloning and sequencing the genes encoding the putative OCT and AD of S. suis, octS and adiS, respectively, revealed that they had 81.2 (octS) and 80.2% (adiS) identity with the respective genes of S. pyogenes. Both genes belong to the AD system, also found in other bacteria. Southern hybridization analysis demonstrated the presence of the adiS gene in all 42 serotype 2 and 9 S. suis strains tested. In 9 of these 42 strains, selected randomly, we confirmed expression of the AdiS protein, homologous to SAGP, by immunoblot analysis using a specific antiserum against the SAGP of S. pyogenes. In all strains AD activity was detected. Furthermore, by immunoelectron microscopy using the anti-S. pyogenes SAGP antiserum we were able to demonstrate that the AdiS protein is expressed on the streptococcal surface in association with the capsular polysaccharides but is not coexpressed with them. PMID:12446626

Impact of bacteria and bacterial components on osteogenic and adipogenic differentiation of adipose-derived mesenchymal stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fiedler, Tomas, E-mail: tomas.fiedler@med.uni-rostock.de; Salamon, Achim; Adam, Stefanie

Adult mesenchymal stem cells (MSC) are present in several tissues, e.g. bone marrow, heart muscle, brain and subcutaneous adipose tissue. In invasive infections MSC get in contact with bacteria and bacterial components. Not much is known about how bacterial pathogens interact with MSC and how contact to bacteria influences MSC viability and differentiation potential. In this study we investigated the impact of three different wound infection relevant bacteria, Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes, and the cell wall components lipopolysaccharide (LPS; Gram-negative bacteria) and lipoteichoic acid (LTA; Gram-positive bacteria) on viability, proliferation, and osteogenic as well as adipogenic differentiationmore » of human adipose tissue-derived mesenchymal stem cells (adMSC). We show that all three tested species were able to attach to and internalize into adMSC. The heat-inactivated Gram-negative E. coli as well as LPS were able to induce proliferation and osteogenic differentiation but reduce adipogenic differentiation of adMSC. Conspicuously, the heat-inactivated Gram-positive species showed the same effects on proliferation and adipogenic differentiation, while its cell wall component LTA exhibited no significant impact on adMSC. Therefore, our data demonstrate that osteogenic and adipogenic differentiation of adMSC is influenced in an oppositional fashion by bacterial antigens and that MSC-governed regeneration is not necessarily reduced under infectious conditions. - Highlights: • Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli bind to and internalize into adMSC. • Heat-inactivated cells of these bacterial species trigger proliferation of adMSC. • Heat-inactivated E. coli and LPS induce osteogenic differentiation of adMSC. • Heat-inactivated E. coli and LPS reduce adipogenic differentiation of adMSC. • LTA does not influence adipogenic or osteogenic differentiation of adMSC.« less

Antimicrobial Susceptibility Survey of Streptococcus pyogenes Isolated in Japan from Patients with Severe Invasive Group A Streptococcal Infections

PubMed Central

Ikebe, Tadayoshi; Hirasawa, Kyoko; Suzuki, Rieko; Isobe, Junko; Tanaka, Daisuke; Katsukawa, Chihiro; Kawahara, Ryuji; Tomita, Masaaki; Ogata, Kikuyo; Endoh, Miyoko; Okuno, Rumi; Watanabe, Haruo

2005-01-01

We assessed antimicrobial susceptibility against 211 Streptococcus pyogenes strains isolated from patients with severe invasive group A streptococcal infections. Overall, 3.8, 1.4, 1.4, and 0.5% of the isolates were resistant to erythromycin, clindamycin, telithromycin, and ciprofloxacin, respectively, and 10.4% had intermediate resistance to ciprofloxacin. All isolates were susceptible to ampicillin and cefotaxime. PMID:15673769

Complete Genome Sequence of a Streptococcus pyogenes Serotype M12 Scarlet Fever Outbreak Isolate from China, Compiled Using Oxford Nanopore and Illumina Sequencing

PubMed Central

You, Yuanhai; Kou, Yongjun; Niu, Longfei; Jia, Qiong; Liu, Yahui; Walker, Mark J.; Zhu, Jiaqiang

2018-01-01

ABSTRACT The incidence of scarlet fever cases remains high in China. Here, we report the complete genome sequence of a Streptococcus pyogenes isolate of serotype M12, which has been confirmed as the predominant serotype in recent outbreaks. Genome sequencing was achieved by a combination of Oxford Nanopore MinION and Illumina methodologies. PMID:29724853

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

PubMed

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 predict the virulence of a S. pyogenes strain in mice and which could be used to identify key aspects of this bacteria's pathogenesis. Copyright © 2016 Elsevier GmbH. All rights reserved.

21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

Code of Federal Regulations, 2011 CFR

2011-04-01

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

21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

Code of Federal Regulations, 2014 CFR

2014-04-01

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

21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

Code of Federal Regulations, 2012 CFR

2012-04-01

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

21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

Code of Federal Regulations, 2013 CFR

2013-04-01

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

A case of meningitis caused by Streptococcus pyogenes in a previously healthy woman.

PubMed

Ulug, Mehmet; Ulug, Nuray Can; Celen, Mustafa Kemal; Geyik, Mehmet Faruk; Ayaz, Celal

2009-04-01

Streptococcus pyogenes is a well-known cause of a variety of clinical infections including local symptoms such as tonsillopharyngitis, cervical lymphadenitis, otitis media, cellulites, erysipelas, as well as more severe diseases such as scarlet fever, osteomyelitis, necrotizing fasciitis, sepsis, and toxic shock syndrome. However, acute bacterial meningitis caused by this pathogen is unusual. We report a case of group A streptococcus (GAS) meningitis in a previously healthy woman with a dramatically rapid course and fatal outcome. A 41-year-old previously healthy woman presented a history of fever, headache, vomiting, and sore throat of three days' duration. Neurological examination revealed diminished consciousness and neck rigidity. The cerebrospinal fluid (CSF) was turbid with 10,000 leukocytes/mm(3). Direct examination of CSF showed Gram-positive cocci in chains, and cultures yielded S. pyogenes. Blood cultures yielded growth of S. pyogenes. The patient was treated initially with ceftriaxone (4 g/day) and the control CSF examination was not changed on the third day, so vancomycin (2 g/day) was added to the treatment; however, she died on the fourth day of the treatment. S. pyogenes meningitis is uncommon and the incidence seems to be persistently low; nevertheless, clinicians should be aware that sporadic cases may occur and may have a fulminant course with a relevant neurological sequel.

Complete Genome Sequence of a Streptococcus pyogenes Serotype M12 Scarlet Fever Outbreak Isolate from China, Compiled Using Oxford Nanopore and Illumina Sequencing.

PubMed

You, Yuanhai; Kou, Yongjun; Niu, Longfei; Jia, Qiong; Liu, Yahui; Davies, Mark R; Walker, Mark J; Zhu, Jiaqiang; Zhang, Jianzhong

2018-05-03

The incidence of scarlet fever cases remains high in China. Here, we report the complete genome sequence of a Streptococcus pyogenes isolate of serotype M12, which has been confirmed as the predominant serotype in recent outbreaks. Genome sequencing was achieved by a combination of Oxford Nanopore MinION and Illumina methodologies. Copyright © 2018 You et al.

The Transcriptional Regulator CpsY Is Important for Innate Immune Evasion in Streptococcus pyogenes

PubMed Central

Vega, Luis A.; Valdes, Kayla M.; Sundar, Ganesh S.; Belew, Ashton T.; Islam, Emrul; Berge, Jacob; Curry, Patrick; Chen, Steven

2016-01-01

ABSTRACT As an exclusively human pathogen, Streptococcus pyogenes (the group A streptococcus [GAS]) has specifically adapted to evade host innate immunity and survive in multiple tissue niches, including blood. GAS can overcome the metabolic constraints of the blood environment and expresses various immunomodulatory factors necessary for survival and immune cell resistance. Here we present our investigation of one such factor, the predicted LysR family transcriptional regulator CpsY. The encoding gene, cpsY, was initially identified as being required for GAS survival in a transposon-site hybridization (TraSH) screen in whole human blood. CpsY is homologous with transcriptional regulators of Streptococcus mutans (MetR), Streptococcus iniae (CpsY), and Streptococcus agalactiae (MtaR) that regulate methionine transport, amino acid metabolism, resistance to neutrophil-mediated killing, and survival in vivo. Our investigation indicated that CpsY is involved in GAS resistance to innate immune cells of its human host. However, GAS CpsY does not manifest the in vitro phenotypes of its homologs in other streptococcal species. GAS CpsY appears to regulate a small set of genes that is markedly different from the regulons of its homologs. The differential expression of these genes depends on the growth medium, and CpsY modestly influences their expression. The GAS CpsY regulon includes known virulence factors (mntE, speB, spd, nga [spn], prtS [SpyCEP], and sse) and cell surface-associated factors of GAS (emm1, mur1.2, sibA [cdhA], and M5005_Spy0500). Intriguingly, the loss of CpsY in GAS does not result in virulence defects in murine models of infection, suggesting that CpsY function in immune evasion is specific to the human host. PMID:27993974

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linke, Christian, E-mail: clin180@ec.auckland.ac.nz; Caradoc-Davies, Tom T.; Australian Synchrotron, Clayton, Victoria 3168

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 themore » 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.« less

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

PubMed Central

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

2014-01-01

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

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

PubMed

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.

Characterization of a Complement-Binding Protein, DRS, from Strains of Streptococcus pyogenes Containing the emm12 and emm55 Genes

PubMed Central

Binks, Michael; Sriprakash, K. S.

2004-01-01

An extracellular protein of Streptococcus pyogenes, streptococcal inhibitor of complement (SIC), and its variant, called DRS (distantly related to SIC), are expressed by some S. pyogenes strains. SIC from type 1 (M1) isolates of S. pyogenes interferes with complement-mediated cell lysis, reportedly via its interaction with complement proteins. In this study we demonstrate that S. pyogenes strains carrying emm12 and emm55 (the genes for the M12 and M55 proteins, respectively) express and secrete DRS. This protein, like SIC, binds to the C6 and C7 complement proteins, and competition enzyme-linked immunosorbent assay experiments demonstrate that DRS competes with SIC for C6 and C7 binding. Similarly, SIC competes with DRS for binding to the complement proteins. Despite this, the recombinant DRS preparation showed no significant effect on complement function, as determined by lysis of sensitized sheep erythrocytes. Furthermore, the presence of DRS is not inhibitory to SIC activity. PMID:15213143

Characterization of a complement-binding protein, DRS, from strains of Streptococcus pyogenes containing the emm12 and emm55 genes.

PubMed

Binks, Michael; Sriprakash, K S

2004-07-01

An extracellular protein of Streptococcus pyogenes, streptococcal inhibitor of complement (SIC), and its variant, called DRS (distantly related to SIC), are expressed by some S. pyogenes strains. SIC from type 1 (M1) isolates of S. pyogenes interferes with complement-mediated cell lysis, reportedly via its interaction with complement proteins. In this study we demonstrate that S. pyogenes strains carrying emm12 and emm55 (the genes for the M12 and M55 proteins, respectively) express and secrete DRS. This protein, like SIC, binds to the C6 and C7 complement proteins, and competition enzyme-linked immunosorbent assay experiments demonstrate that DRS competes with SIC for C6 and C7 binding. Similarly, SIC competes with DRS for binding to the complement proteins. Despite this, the recombinant DRS preparation showed no significant effect on complement function, as determined by lysis of sensitized sheep erythrocytes. Furthermore, the presence of DRS is not inhibitory to SIC activity.

Molecular typing of Chinese Streptococcus pyogenes isolates.

PubMed

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

2015-06-01

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

Cloning and characterization of two novel DNases from Streptococcus pyogenes.

PubMed

Hasegawa, Tadao; Torii, Keizo; Hashikawa, Shinnosuke; Iinuma, Yoshitsugu; Ohta, Michio

2002-06-01

The proteins in the culture supernatant (exoproteins) from Streptococcus pyogenes serotype M1 were separated by two-dimensional gel electrophoresis, and their N-terminal amino acid sequences were determined. The amino acid sequences were compared to sequences in the S. pyogenes genome database. The coding sequence showed similarity to sequences of two genes, mf2-v ( mf2 variant) and mf3, which had sequence similarity to genes encoding mitogenic factor (MF); MF has DNase activity. The recombinant genes were expressed in Escherichia coli and the proteins were synthesized. Mf2-v and Mf3 had DNase activity. The activity of Mf2-v was localized to the C-terminal half of the protein. The mf3 gene was shown to be present in most clinically isolated strains of S. pyogenes tested, and the mf2gene was detected in 20% of the isolates. The products of the mf2 and mf3 genes in clinically isolated S. pyogenes strains were thus shown to be DNases.

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

PubMed

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.

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

PubMed

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

2015-11-01

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

Changing prevalent T serotypes and emm genotypes of Streptococcus pyogenes isolates from streptococcal toxic shock-like syndrome (TSLS) patients in Japan.

PubMed

Ikebe, T; Murai, N; Endo, M; Okuno, R; Murayama, S; Saitoh, K; Yamai, S; Suzuki, R; Isobe, J; Tanaka, D; Katsukawa, C; Tamaru, A; Katayama, A; Fujinaga, Y; Hoashi, K; Ishikawa, J; Watanabe, H

2003-06-01

We surveyed T serotypes and emm genotypes of Streptococcus pyogenes isolates from streptococcal toxic shock-like syndrome (TSLS) patients. T1 (emm1) remained dominant through 1992 to 2000, but the dominant T3 (emm3.1) strains from 1992 to 1995 disappeared during 1996-2000. Strains of several emm genotypes emerged during 1996-2000, indicating alterations in the prevalent strains causing TSLS.

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

PubMed

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

2016-03-15

Streptococcus pyogenes is a clinically important pathogen consisting of various serotypes determined by different M proteins expressed on the cell surface. The M type is therefore a useful marker to monitor the spread of invasive S. pyogenes in a population. Serotyping and nucleic acid amplification/sequencing methods for the identification of M types are laborious, inconsistent, and usually confined to reference laboratories. The primary objective of this work is to develop a technique that enables generation of aptamers binding to specific M-types of S. pyogenes. We describe here an in vitro technique that directly used live bacterial cells and the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) strategy. Live S. pyogenes cells were incubated with DNA libraries consisting of 40-nucleotides randomized sequences. Those sequences that bound to the cells were separated, amplified using polymerase chain reaction (PCR), purified using gel electrophoresis, and served as the input DNA pool for the next round of SELEX selection. A specially designed forward primer containing extended polyA20/5Sp9 facilitated gel electrophoresis purification of ssDNA after PCR amplification. A counter-selection step using non-target cells was introduced to improve selectivity. DNA libraries of different starting sequence diversity (10(16) and 10(14)) were compared. Aptamer pools from each round of selection were tested for their binding to the target and non-target cells using flow cytometry. Selected aptamer pools were then cloned and sequenced. Individual aptamer sequences were screened on the basis of their binding to the 10 M-types that were used as targets. Aptamer pools obtained from SELEX rounds 5-8 showed high affinity to the target S. pyogenes cells. Tests against non-target Streptococcus bovis, Streptococcus pneumoniae, and Enterococcus species demonstrated selectivity of these aptamers for binding to S. pyogenes. Several aptamer sequences were found to bind preferentially to the M11 M-type of S. pyogenes. Estimated binding dissociation constants (Kd) were in the low nanomolar range for the M11 specific sequences; for example, sequence E-CA20 had a Kd of 7±1 nM. These affinities are comparable to those of a monoclonal antibody. The improved bacterial cell-SELEX technique is successful in generating aptamers selective for S. pyogenes and some of its M-types. These aptamers are potentially useful for detecting S. pyogenes, achieving binding profiles of the various M-types, and developing new M-typing technologies for non-specialized laboratories or point-of-care testing. Copyright © 2015 Elsevier Inc. All rights reserved.

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

PubMed Central

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

Genome Analysis of Streptococcus pyogenes Associated with Pharyngitis and Skin Infections

PubMed Central

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

Prevalence of β-hemolytic Streptococcus in children with special health care needs.

PubMed

Morais, Viviane Martha Santos de; Orsi, Alice Ramos; Maranhão, Fernanda Cristina de Albuquerque; Castro, Therezita Maria Peixoto Patury Galvão; Castro, Karina Cavalcante Beltrão de; Silva, Denise Maria Wanderlei

2012-10-01

Pharyngotonsillitis by β-hemolytic Streptococcus mostly affects children and immunocompromised, being Streptococcus pyogenes (Group A) the most common agent in bacterial pharyngotonsillitis. This work targeted the research of β-hemolytic Streptococcus Group-A (SBHGA) and No-A (SBHGNA) in the oropharynx of individuals with special health needs from the APAE (Maceió-AL). A prospective study with oropharynx samples from patients with Down syndrome and other mental disorders (test) and students from a private school (control) aged 5-15 years. Cultures in blood agar (5%) were identified through Gram/catalase tests and bacitracin/trimethoprim-sulfamethoxazole disk diffusion method, applying the chi-squared statistical analysis. A total of 222 bacterial colonies were isolated in 74 individuals from APAE and 65 in the control group. In the test group, previous episodes of pharyngotonsillitis were reported by 36.49% (27/74) and 9.46% (7/74) were diagnosed with symptoms and/or signs suggestive of oropharynx infection. No positive sample of S. pyogenes was confirmed at APAE, being all samples classified as SBHGNA, with 5 SBHGA in the control group. The early identification of β-hemolytic Streptococcus is important for the fast treatment of pharyngotonsillitis and the absence of S. pyogenes avoid future suppurative or not-suppurative sequels in the group from APAE.

Impetigo

MedlinePlus

... It's usually caused by one of two bacteria: Staphylococcus aureus or Streptococcus pyogenes (also called group A streptococcus, which also causes strep throat ). Methicillin-resistant Staphylococcus aureus ( MRSA ) is also becoming an important cause of ...

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

PubMed

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

2014-06-27

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

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

PubMed

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.

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

PubMed

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

2013-09-01

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

Factors that cause trimethoprim resistance in Streptococcus pyogenes.

PubMed

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

2014-01-01

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

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

PubMed Central

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

2001-01-01

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

Streptococcal acute pharyngitis.

PubMed

Anjos, Lais Martins Moreira; Marcondes, Mariana Barros; Lima, Mariana Ferreira; Mondelli, Alessandro Lia; Okoshi, Marina Politi

2014-07-01

Acute pharyngitis/tonsillitis, which is characterized by inflammation of the posterior pharynx and tonsils, is a common disease. Several viruses and bacteria can cause acute pharyngitis; however, Streptococcus pyogenes (also known as Lancefield group A β-hemolytic streptococci) is the only agent that requires an etiologic diagnosis and specific treatment. S. pyogenes is of major clinical importance because it can trigger post-infection systemic complications, acute rheumatic fever, and post-streptococcal glomerulonephritis. Symptom onset in streptococcal infection is usually abrupt and includes intense sore throat, fever, chills, malaise, headache, tender enlarged anterior cervical lymph nodes, and pharyngeal or tonsillar exudate. Cough, coryza, conjunctivitis, and diarrhea are uncommon, and their presence suggests a viral cause. A diagnosis of pharyngitis is supported by the patient's history and by the physical examination. Throat culture is the gold standard for diagnosing streptococcus pharyngitis. However, it has been underused in public health services because of its low availability and because of the 1- to 2-day delay in obtaining results. Rapid antigen detection tests have been used to detect S. pyogenes directly from throat swabs within minutes. Clinical scoring systems have been developed to predict the risk of S. pyogenes infection. The most commonly used scoring system is the modified Centor score. Acute S. pyogenes pharyngitis is often a self-limiting disease. Penicillins are the first-choice treatment. For patients with penicillin allergy, cephalosporins can be an acceptable alternative, although primary hypersensitivity to cephalosporins can occur. Another drug option is the macrolides. Future perspectives to prevent streptococcal pharyngitis and post-infection systemic complications include the development of an anti-Streptococcus pyogenes vaccine.

Factors That Cause Trimethoprim Resistance in Streptococcus pyogenes

PubMed Central

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

2014-01-01

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

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

PubMed

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

2016-06-01

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

Streptococcus pyogenes Infection and the Human Proteome with a Special Focus on the Immunoglobulin G-cleaving Enzyme IdeS.

PubMed

Karlsson, Christofer A Q; Järnum, Sofia; Winstedt, Lena; Kjellman, Christian; Björck, Lars; Linder, Adam; Malmström, Johan A

2018-06-01

Infectious diseases are characterized by a complex interplay between host and pathogen, but how these interactions impact the host proteome is unclear. Here we applied a combined mass spectrometry-based proteomics strategy to investigate how the human proteome is transiently modified by the pathogen Streptococcus pyogenes , with a particular focus on bacterial cleavage of IgG in vivo In invasive diseases, S. pyogenes evokes a massive host response in blood, whereas superficial diseases are characterized by a local leakage of several blood plasma proteins at the site of infection including IgG. S. pyogenes produces IdeS, a protease cleaving IgG in the lower hinge region and we find highly effective IdeS-cleavage of IgG in samples from local IgG poor microenvironments. The results show that IdeS contributes to the adaptation of S. pyogenes to its normal ecological niches. Additionally, the work identifies novel clinical opportunities for in vivo pathogen detection. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Characterization of Streptococcus pyogenes from Animal Clinical Specimens, Spain

PubMed Central

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

2017-01-01

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. PMID:29148379

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

PubMed Central

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

2013-01-01

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

Streptococcus pyogenes pharyngeal colonization resulting in recurrent, prepubertal vulvovaginitis.

PubMed

Hansen, Megan T; Sanchez, Veronica T; Eyster, Kathleen; Hansen, Keith A

2007-10-01

Recurrent, prepubertal, vaginal infections are an uncommon, troublesome problem for the patient and her family. Failure of initial therapy to alleviate vulvovaginitis may be related to vulvar skin disease, foreign body, sexual abuse, pinworms, reactions to medications, anatomic anomalies, or allergies. This report describes a case of recurrent Streptococcus pyogenes vulvovaginitis secondary to presumed vaginal re-inoculation from pharyngeal colonization. A 4-yr-old presented with one year of culture proven, recurrent Streptococcus pyogenes vulvovaginitis. Her symptoms repeatedly resolved with penicillin therapy, but continued to recur following cessation of antibiotic therapy. Evaluation included physical examination, trans-abdominal pelvic ultrasound, and vaginoscopy which all revealed normal upper and lower genital tract anatomy. Both the patient and her mother demonstrated culture proven, Group A Streptococcus pharyngeal colonization. Because of the possibility of repeated inoculations of the vaginal area from the colonized pharynx, they were both treated for decolonization with a regimen of amoxicillin and rifampin for ten days. Following this therapy there was resolution of vaginal symptoms with no further recurrence. Follow-up pharyngeal culture done on both mother and child on their last visit were negative for Group A Streptococcus. This case demonstrated an unusual specific cause of recurrent vaginitis resulting from presumed self or maternal re-inoculation with group A beta-hemolytic streptococcus from pharyngeal colonization. Group A beta-hemolytic streptococcus are consistently sensitive to penicillin, but up to 25% of acute pharyngitis cases treated with penicillin having continued asymptomatic, bacterial carriage within the nasopharynx. Thus initial alleviation of symptoms in a patient with Group A beta-hemolytic vulvovaginitis treated with penicillin, can have continued asymptomatic pharyngeal colonization which can result in recurrence of the vulvovaginitis. This case stresses the importance of considering re-infection through this route in the patient with recurrent Group A beta-hemolytic streptococcus vulvovaginitis.

Prevalence of Bovine Mastitis Pathogens in Bulk Tank Milk in China

PubMed Central

Wang, Ya Jing; Qin, Yun; Guix Vallverdú, Roger; Maldonado García, Jaime; Sun, Wei; Li, Shengli; Cao, Zhijun

2016-01-01

The objectives of this study were to estimate the herd prevalence of major mastitis pathogens in bulk tank milk (BTM) in China dairy herds, to determine the relationship between the presence of mastitis pathogens and bulk tank milk somatic cell counts (BTSCC), and to investigate the impact of different dairy cattle farming modes and region on bacterial species. BTM samples collected from 894 dairy herds in China were examined for the presence of mastitis pathogens. The Flinders Technology Associates (FTA) cards were used for BTM sample collection, storage, and transportation and bacterial DNA amplification by real-time PCR. Among contagious pathogens, Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae were detected in 50.1, 92.2, and 72.3% of the 894 BTM samples, respectively. Among environmental pathogens, E. coli, Streptococcus uberis, Enterococcus spp., Klebsiella spp., Serratia marcescens, Corynebacterium bovis, and Arcanobacterium pyogenes were detected in 28.6, 8.9, 35.7, 20.0, 1.3, 17.0, and 67.2% of the BTM samples, respectively. Staphylococcal β-lactamase gene was detected in 61.7% of the BTM samples. The presence of Staphylococcus aureus and Arcanobacterium pyogenes were significantly associated with high BTSCC, respectively. Significant differences were found in presence of Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae in BTM sampled from the small household farms, dairy-farming communities, and large-scaled dairy farms. There were significant differences in the presence of Streptococcus agalactiae, Streptococcus dysgalactiae, Arcanobacterium pyogenes, staphylococcal β-lactamase gene, Staphylococcus spp., Klebsiella spp., Enterococcus spp., and Streptococcus uberis in BTM among Inner Mongolia, Heilongjiang, and Hebei province. In conclusion, contagious mammary pathogens are predominated among pathogens in BTM samples in China. PMID:27187065

Potential Factors Enabling Human Body Colonization by Animal Streptococcus dysgalactiae subsp. equisimilis Strains.

PubMed

Ciszewski, Marcin; Szewczyk, Eligia M

2017-05-01

Streptococcus dysgalactiae subsp. equisimilis (SDSE) is a pyogenic, Lancefield C or G streptococcal pathogen. Until recently, it has been considered as an exclusive animal pathogen. Nowadays, it is responsible for both animal infections in wild animals, pets, and livestock and human infections often clinically similar to the ones caused by group A streptococcus (Streptococcus pyogenes). The risk of zoonotic infection is the most significant in people having regular contact with animals, such as veterinarians, cattlemen, and farmers. SDSE is also prevalent on skin of healthy dogs, cats, and horses, which pose a risk also to people having contact with companion animals. The main aim of this study was to evaluate if there are features differentiating animal and human SDSE isolates, especially in virulence factors involved in the first stages of pathogenesis (adhesion and colonization). Equal groups of human and animal SDSE clinical strains were obtained from superficial infections (skin, wounds, abscesses). The presence of five virulence genes (prtF1, prtF2, lmb, cbp, emm type) was evaluated, as well as ability to form bacterial biofilm and produce BLIS (bacteriocin-like inhibitory substances) which are active against human skin microbiota. The study showed that the presence of genes coding for fibronectin-binding protein and M protein, as well as BLIS activity inhibiting the growth of Corynebacterium spp. strains might constitute the virulence factors which are necessary to colonize human organism, whereas they are not crucial in animal infections. Those virulence factors might be horizontally transferred from human streptococci to animal SDSE strains, enabling their ability to colonize human organism.

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

PubMed

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

2014-02-01

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

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

PubMed

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

2016-07-01

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

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

PubMed Central

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

2016-01-01

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

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

PubMed

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.

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

PubMed Central

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

2016-01-01

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

A Glycine Riboswitch in Streptococcus pyogenes Controls Expression of a Sodium:Alanine Symporter Family Protein Gene.

PubMed

Khani, Afsaneh; Popp, Nicole; Kreikemeyer, Bernd; Patenge, Nadja

2018-01-01

Regulatory RNAs play important roles in the control of bacterial gene expression. In this study, we investigated gene expression regulation by a putative glycine riboswitch located in the 5'-untranslated region of a sodium:alanine symporter family (SAF) protein gene in the group A Streptococcus pyogenes serotype M49 strain 591. Glycine-dependent gene expression mediated by riboswitch activity was studied using a luciferase reporter gene system. Maximal reporter gene expression was observed in the absence of glycine and in the presence of low glycine concentrations. Differences in glycine-dependent gene expression were not based on differential promoter activity. Expression of the SAF protein gene and the downstream putative cation efflux protein gene was investigated in wild-type bacteria by RT-qPCR transcript analyses. During growth in the presence of glycine (≥1 mM), expression of the genes were downregulated. Northern blot analyses revealed premature transcription termination in the presence of high glycine concentrations. Growth in the presence of 0.1 mM glycine led to the production of a full-length transcript. Furthermore, stability of the SAF protein gene transcript was drastically reduced in the presence of glycine. We conclude that the putative glycine riboswitch in S. pyogenes serotype M49 strain 591 represses expression of the SAF protein gene and the downstream putative cation efflux protein gene in the presence of high glycine concentrations. Sequence and secondary structure comparisons indicated that the streptococcal riboswitch belongs to the class of tandem aptamer glycine riboswitches.

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

PubMed

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.

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

PubMed Central

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

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

PubMed

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

2017-03-17

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.

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

PubMed

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

2014-12-01

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

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

PubMed

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

2016-07-01

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

Asymptomatic throat carriage rate and antimicrobial resistance pattern of Streptococcus pyogenes in Nepalese school children.

PubMed

Dumre, S P; Sapkota, K; Adhikari, N; Acharya, D; Karki, M; Bista, S; Basanyat, S R; Joshi, S K

2009-01-01

Streptococcus pyogenes or Group A streptococcus (GAS) causes several suppurative and non suppurative infections. In addition to pharyngitis and skin infections, GAS are also the causative agent of post-streptococcal infection syndromes such as acute rheumatic fever (ARF) and post-streptococcal glumerulonephritis (PSG). GAS frequently colonises in the throat of an asymptomatic person. Pharyngeal carriage rates of GAS among healthy school children vary with geographical location and seasons. We carried out this preliminary study to determine the throat carriage rate and antimicrobial resistance trend of Streptococcus pyogenes or Group A streptococcus (GAS) among the Nepalese school children. Four schools situated at different locations of Kathmandu valley were included in the study. Throat swabs from 350 students of age group 5-15 years were collected, immediately transported to the laboratory and were processed for S. pyogenes following standard microbiological procedures. Antimicrobial susceptibility testing of the isolates was performed by Kirby Bauer disc diffusion method following CLSI guidelines. S. pyogenes was isolated from 10.9% (38/350) of the screened children. The GAS colonisation rate was statistically insignificant (P>0.05) with sex and age sub-groups, although the rate was slightly higher among girls and age sub-group 9-12 years. No significant difference in carrier rate was observed among different schools (P>0.05). All isolates were susceptible to azithromycin. No resistance was detected for penicillin and its derivative antibiotic ampicillin. Highest resistance rate was observed for cotrimoxazole (71.0%) followed by chloramphenicol (7.8%), ciprofloxacin (5.2%) and erythromycin (5.2%). Antibiotic resistant GAS isolated from asymptomatic Nepalese school children is a public health concern. When screened and appropriately treated with antibiotics, carriers can be prevented from spreading of streptococcal infections in the school environment and the community. Preventing cross infections would ultimately reduce the incidence of life-threatening sequelae which are debilitating and difficult to treat. It is recommended to conduct regular screening and GAS surveillance in schools, and maintain rational use of antibiotics to minimise GAS carriage/infections and resistance.

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

PubMed

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

1995-03-28

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

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

PubMed

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.

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

PubMed

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.

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

PubMed

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

2014-10-01

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

Comparative in-vitro activities of quinupristin-dalfopristin against Gram-positive bloodstream isolates.

PubMed

Schouten, M A; Hoogkamp-Korstanje, J A

1997-08-01

The in-vitro activity of quinupristin-dalfopristin was compared with those of vancomycin, teicoplanin, erythromycin, clarithromycin, rifampicin, imipenem, meropenem, ciprofloxacin and sparfloxacin against 414 bloodstream isolates of Gram-positive cocci. Quinupristin-dalfopristin inhibited strains of Streptococcus pyogenes and Streptococcus agalactiae at 0.12 mg/L, methicillin- and/or erythromycin-resistant Staphylococcus aureus and Staphylococcus epidermidis at 0.5 mg/L, Staphylococcus haemolyticus, Enterococcus faecium, Streptococcus pneumoniae, Streptococcus mitis, Streptococcus bovis, Streptococcus sanguis and Streptococcus anginosus at 1 mg/L and Enterococcus faecalis at 8 mg/L.

[Streptococcus pyogenes or group A streptococcal infections in child: French national reference center data].

PubMed

Bidet, P; Plainvert, C; Doit, C; Mariani-Kurkdjian, P; Bonacorsi, S; Lepoutre, A; Bouvet, A; Poyart, C; Bingen, E

2010-02-01

Since the 1980s, infections due to Streptococcus pyogenes or group A streptococci (GAS) were marked by the increase in invasive infections and the emergence of clones which were resistant to macrolides. Those challenges led the French national reference center for streptococci to enhance the epidemiological survey and the characterization of GAS strains, in collaboration with the National Institute for Public Health Surveillance. Active surveillance is of major importance for implementation of therapeutic and prophylactic guidelines and for evaluation of future streptococcal vaccines. Copyright 2009 Elsevier Masson SAS. All rights reserved.

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

PubMed Central

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

2015-01-01

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 Mg2+, Ca2+, or Mn2+. However, Zn2+ 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. PMID:26527680

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

PubMed

Sakai, Tetsuya; Taniyama, Daisuke; Takahashi, Saeko; Nakamura, Morio; Takahashi, Takashi

2017-01-01

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.

[Evaluation of Prolex for the rapid identification of streptococci isolated in medical microbiology].

PubMed

Loubinoux, J; Mihaila-Amrouche, L; Bouvet, A

2004-10-01

The need to rapidly identify streptococci responsible for acute infectious diseases has led to the development of agglutination techniques that are able to identify streptococcal group antigens (A, B, C, D, F, and G) directly from primoculture colonies on blood agar. The Prolex agglutination tests (Pro-Lab Diagnostics, Richmond Hill, Ontario, Canada), distributed in France by i2a, have been used for the determination of group antigens of 166 isolates of streptococci and enterococci previously identified in the National Reference Center for Streptococci. The results obtained with the Prolex reagents have permitted to correctly identify all pyogenic beta-hemolytic streptococci (23 Streptococcus pyogenes, 21 Streptococcus agalactiae, 33 Streptococcus dysgalactiae subsp. equisimilis including 6 group C and 27 group G, and 5 Streptococcus porcinus including 4 group B). Four differences between unexpected agglutinations (A or F) and species identifications have been obtained. These differences were observed for four non-hemolytic isolates of Streptococcus mutans, Streptococcus gordonii, Streptococcus infantarius, and Streptococcus suis. The anti-D reagent has been of value as a marker for isolates of enterococci. Thus, these results confirm the abilities of these agglutination tests for the grouping of beta-hemolytic streptococci. Moreover, the use of Prolex has the advantage to be rapid because of the non-enzymatic but chemical extraction of streptococcal antigens.

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

PubMed

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 the key outcome of these molecular events is evolution of a new, more virulent pathogenic genotype. Our findings provide new understanding of epidemic disease. Copyright © 2016 Beres et al.

[Antibiotic resistance to erythromycin, clindamycin and tetracycline of 573 strains of Streptococcus pyogenes (1992-1994)].

PubMed

Orden, B; Martínez, R; López de los Mozos, A; Franco, A

1996-02-01

The aim of this study was to know the antibiotic resistence of Streptococcus pyogenes to erythromycine, clindamycine and/or tetracycline in community samples. The second aim was to determine the existence of multiresistant strains and to know the relationship between resistant strains, clinical samples and age of the patient. A retrospective analysis was performed in all the strains of S. pyogenes isolated from January 1992 to December 1994. Antibiotic sensitivity was studied by MIC by the microdilution method using the Pasco semiautomatic system. During the study period 573 beta hemolytic streptococci were identified as S. pyogenes. The global resistance to erythromycine (2.8%), clindamycine (1.4%) and tetracycline (7.3%) remains at low levels but has significantly increased in the case of erythromycine (p < 0.05) and tetracycline (p < 0.05) over these 3 years. The incidence of strains resistant to clindamycine has also increased slowly although this rise is not significant. Five strains (0.9%) were not sensitive to the three antibiotics studied, 4 being isolated in the last trimester of 1994 in pharyngeal exudates. S. pyogenes resistant to erythromycine was most frequently isolated from cutaneous lesions and in pediatric patients (under the age of 14 years). These results confirm the trend towards an increase in the number of strains of S. pyogenes resistant to erythromycine, clindamycine and/or tetracycline, being most often found in cutaneous lesions and pediatric patients.

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

PubMed Central

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

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

PubMed

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

2016-02-01

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

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

PubMed

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.

Antibacterial activity and mechanism of action of Monarda punctata essential oil and its main components against common bacterial pathogens in respiratory tract.

PubMed

Li, Hong; Yang, Tian; Li, Fei-Yan; Yao, Yan; Sun, Zhong-Min

2014-01-01

The aim of the current research work was to study the chemical composition of the essential oil of Monarda punctata along with evaluating the essential oil and its major components for their antibacterial effects against some frequently encountered respiratory infection causing pathogens. Gas chromatographic mass spectrometric analysis revealed the presence of 13 chemical constituents with thymol (75.2%), p-cymene (6.7%), limonene (5.4), and carvacrol (3.5%) as the major constituents. The oil composition was dominated by the oxygenated monoterpenes. Antibacterial activity of the essential oil and its major constituents (thymol, p-cymene, limonene) was evaluated against Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Haemophilus influenzae and Escherichia coli. The study revealed that the essential oil and its constituents exhibited a broad spectrum and variable degree of antibacterial activity against different strains. Among the tested strains, Streptococcus pyogenes, Escherichia coli and Streptococcus pneumoniae were the most susceptible bacterial strain showing lowest MIC and MBC values. Methicillin-resistant Staphylococcus aureus was the most resistant bacterial strain to the essential oil treatment showing relatively higher MIC and MBC values. Scanning electron microscopy revealed that the essential oil induced potent and dose-dependent membrane damage in S. pyogenes and MRSA bacterial strains. The reactive oxygen species generated by the Monarda punctata essential oil were identified using 2', 7'-dichlorofluorescein diacetate (DCFDA).This study indicated that the Monarda punctata essential oil to a great extent and thymol to a lower extent triggered a substantial increase in the ROS levels in S. pyogenes bacterial cultures which ultimately cause membrane damage as revealed by SEM results.

Antibacterial activity and mechanism of action of Monarda punctata essential oil and its main components against common bacterial pathogens in respiratory tract

PubMed Central

Li, Hong; Yang, Tian; Li, Fei-Yan; Yao, Yan; Sun, Zhong-Min

2014-01-01

The aim of the current research work was to study the chemical composition of the essential oil of Monarda punctata along with evaluating the essential oil and its major components for their antibacterial effects against some frequently encountered respiratory infection causing pathogens. Gas chromatographic mass spectrometric analysis revealed the presence of 13 chemical constituents with thymol (75.2%), p-cymene (6.7%), limonene (5.4), and carvacrol (3.5%) as the major constituents. The oil composition was dominated by the oxygenated monoterpenes. Antibacterial activity of the essential oil and its major constituents (thymol, p-cymene, limonene) was evaluated against Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Haemophilus influenzae and Escherichia coli. The study revealed that the essential oil and its constituents exhibited a broad spectrum and variable degree of antibacterial activity against different strains. Among the tested strains, Streptococcus pyogenes, Escherichia coli and Streptococcus pneumoniae were the most susceptible bacterial strain showing lowest MIC and MBC values. Methicillin-resistant Staphylococcus aureus was the most resistant bacterial strain to the essential oil treatment showing relatively higher MIC and MBC values. Scanning electron microscopy revealed that the essential oil induced potent and dose-dependent membrane damage in S. pyogenes and MRSA bacterial strains. The reactive oxygen species generated by the Monarda punctata essential oil were identified using 2’, 7’-dichlorofluorescein diacetate (DCFDA).This study indicated that the Monarda punctata essential oil to a great extent and thymol to a lower extent triggered a substantial increase in the ROS levels in S. pyogenes bacterial cultures which ultimately cause membrane damage as revealed by SEM results. PMID:25550774

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

PubMed

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

2015-07-09

Integrative conjugative elements (ICEs) are mobile genetic elements that reside in the chromosome but retain the ability to undergo excision and to transfer by conjugation. Genes involved in drug resistance, virulence, or niche adaptation are often found among backbone genes as cargo DNA. We recently characterized in Streptococcus suis an ICE (ICESsu32457) carrying resistance genes [tet(O/W/32/O), tet(40), erm(B), aphA, and aadE] in the 15K unstable genetic element, which is flanked by two ∼1.3kb direct repeats. Remarkably, ∼1.3-kb sequences are conserved in ICESa2603 of Streptococcus agalactiae 2603V/R, which carry heavy metal resistance genes cadC/cadA and mer. In matings between S. suis 32457 (donor) and S. agalactiae 2603V/R (recipient), transconjugants were obtained. PCR experiments, PFGE, and sequence analysis of transconjugants demonstrated a tandem array between ICESsu32457 and ICESa2603. Matings between tandem array-containing S. agalactiae 2603V/R (donor) and Streptococcus pyogenes RF12 (recipient) yielded a single transconjugant containing a hybrid ICE, here named ICESa2603/ICESsu32457. The hybrid formed by recombination of the left ∼1.3-kb sequence of ICESsu32457 and the ∼1.3-kb sequence of ICESa2603. Interestingly, the hybrid ICE was transferable between S. pyogenes strains, thus demonstrating that it behaves as a conventional ICE. These findings suggest that both tandem arrays and hybrid ICEs may contribute to the evolution of antibiotic resistance in streptococci, creating novel mobile elements capable of disseminating new combinations of antibiotic resistance genes. Copyright © 2015 Elsevier B.V. All rights reserved.

Streptococcus pyogenes vulvovaginitis in children in Nottingham.

PubMed Central

Donald, F. E.; Slack, R. C.; Colman, G.

1991-01-01

Isolates of Streptococcus pyogenes from vaginal swabs of children with vulvovaginitis received at Nottingham Public Health Laboratory during 1986-9 were studied. A total of 159 isolates was made during the 4 years, increasing from 17 in 1986 to 64 in 1989 and accounting for 11% of all vaginal swabs received from children. The numbers of throat swabs yielding S. pyogenes also showed an increase from 974 in 1986 to 1519 in 1989. A winter peak of isolates was noted for both vaginal swabs and throat swabs. A total of 98 strains from vaginal swabs were serotyped: 22 different types were identified, 61% of which were the common types M4, M6, R28 and M12. Erythromycin sensitivity was done on 89 strains; 84% were highly sensitive (MIC less than 0.03 mg/l). There are no other reports of such large numbers in the literature; the reason for seeing this increase in Nottingham is unclear. PMID:2050200

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

PubMed

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

2013-09-01

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

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

PubMed Central

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

2014-01-01

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

A highly active and negatively charged Streptococcus pyogenes lysin with a rare D-alanyl-L-alanine endopeptidase activity protects mice against streptococcal bacteremia.

PubMed

Lood, Rolf; Raz, Assaf; Molina, Henrik; Euler, Chad W; Fischetti, Vincent A

2014-06-01

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. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Fluoroquinolone Resistance in Streptococcus dysgalactiae subsp. equisimilis and Evidence for a Shared Global Gene Pool with Streptococcus pyogenes▿

PubMed Central

Pinho, M. D.; Melo-Cristino, J.; Ramirez, M.

2010-01-01

Quinolone resistance is an emerging problem in Streptococcus pyogenes, and recombination with Streptococcus dysgalactiae DNA has been implicated as a frequent mechanism leading to resistance. We have characterized a collection of S. dysgalactiae subsp. equisimilis isolates responsible for infections in humans (n = 314) and found a high proportion of levofloxacin-resistant isolates (12%). Resistance was associated with multiple emm types and genetic lineages, as determined by pulsed-field gel electrophoretic profiling. Since we could not find evidence for a role of efflux pumps in resistance, we sequenced the quinolone resistance-determining regions of the gyrA and parC genes of representative resistant and susceptible isolates. We found much greater diversity among the parC genes (19 alleles) than among the gyrA genes (5 alleles). While single mutations in either GyrA or ParC were sufficient to raise the MIC so that the strains were classified as intermediately resistant, higher-level resistance was associated with mutations in both GyrA and ParC. Evidence for recombination with S. pyogenes DNA was found in some parC alleles, but this was not exclusively associated with resistance. Our data support the existence of a common reservoir of genes conferring quinolone resistance shared between S. dysgalactiae subsp. equisimilis and S. pyogenes, while no recombination with the animal pathogen S. dysgalactiae subsp. dysgalactiae could be found. PMID:20145082

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

PubMed Central

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

2009-01-01

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

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

PubMed

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

2016-01-01

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

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

PubMed Central

Mashburn-Warren, Lauren; Morrison, Donald A.

2012-01-01

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

Survival of Streptococcus suis, Streptococcus dysgalactiae and Trueperella pyogenes in dry-cured Iberian pork shoulders and loins.

PubMed

Cardoso-Toset, F; Luque, I; Morales-Partera, A; Galán-Relaño, A; Barrero-Domínguez, B; Hernández, M; Gómez-Laguna, J

2017-02-01

Dry-cured hams, shoulders and loins of Iberian pigs are highly appreciated in national and international markets. Salting, additive addition and dehydration are the main strategies to produce these ready-to-eat products. Although the dry curing process is known to reduce the load of well-known food borne pathogens, studies evaluating the viability of other microorganisms in contaminated pork have not been performed. In this work, the efficacy of the dry curing process to eliminate three swine pathogens associated with pork carcass condemnation, Streptococcus suis, Streptococcus dysgalactiae and Trueperella pyogenes, was evaluated. Results of this study highlight that the dry curing process is a suitable method to obtain safe ready-to-eat products free of these microorganisms. Although salting of dry-cured shoulders had a moderate bactericidal effect, results of this study suggest that drying and ripening were the most important stages to obtain dry-cured products free of these microorganisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

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

2016-08-20

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

Periorbital Necrotizing Fasciitis Secondary to Candida parapsilosis and Streptococcus pyogenes.

PubMed

Zhang, Matthew; Chelnis, James; Mawn, Louise A

Necrotizing fasciitis is most often caused by either polymicrobial bacterial infections or by Gram-positive organisms, such as Streptococcus or Staphylococcus; however, rare cases of fungal necrotizing fasciitis have been reported. Candida parapsilosis is an emerging fungal pathogen. This fungus grows in either a yeast or pseudohyphal form. C. parapsilosis has been reported to cause keratitis, intraocular infection, and seeding of frontalis slings. C. parapsilosis is a commensal of human skin and can be acquired by nosocomial spread. Necrotizing fasciitis due to Candida has rarely been reported, but to date C. parapsilosis has not been identified as the causative organism in necrotizing fasciitis. This is the first documented case of human periocular soft tissue infection by C. parapsilosis, and also the first report providing evidence of mycotic infection in a necrotizing fasciitis concurrently infected by Streptococcus pyogenes.

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

PubMed

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

2015-06-01

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

Zinc disrupts central carbon metabolism and capsule biosynthesis in Streptococcus pyogenes

PubMed Central

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

2015-01-01

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

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

PubMed

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.

mga genosensor for early detection of human rheumatic heart disease.

PubMed

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

2014-05-01

The 5' amino-labeled DNA probe complementary to mga gene of Streptococcus pyogenes was immobilized on carboxylated multiwall carbon nanotubes electrode and hybridized with 0.1-100 ng/6 μl single-stranded genomic DNA (ssG-DNA) of S. pyogenes from throat swab of suspected rheumatic heart disease (RHD) patients. Electrochemical response was measured by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance (EI). The sensitivity of the sensor was 106.03 (μA/cm(2))/ng and limit of detection (LOD) was found 0.014 ng/6 μl with regression coefficient (R(2)) of 0.921 using DPV. The genosensor was characterized by FTIR and SEM, and electrode was found stable for 6 months on storage at 4 °C with 5-6 % loss in initial DPV current. mga genosensor is the first report on RHD sensor which can save life of several suspected patients by early diagnosis in 30 min.

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

PubMed

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

2015-12-25

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

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

PubMed

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.

Local Changes in Rates of Group A Streptococcus Disease and Antibiotic Resistance are Associated with Geographically Widespread Strain Turnover Events

DTIC Science & Technology

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

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

PubMed

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 strains with the clade 3 phenotype (absence of capsule and high expression of SPN and SLO) are highly virulent in mice. These findings provide new understanding of how new virulent clones emerge and cause severe infections worldwide. This newfound knowledge of S. pyogenes virulence can be used to help understand future epidemics and conduct new translational research. Copyright © 2015 Zhu et al.

Macrolide resistance gene erm(TR) and erm(TR)-carrying genetic elements in Streptococcus agalactiae: characterization of ICESagTR7, a new composite element containing IMESp2907.

PubMed

Mingoia, Marina; Morici, Eleonora; Marini, Emanuela; Brenciani, Andrea; Giovanetti, Eleonora; Varaldo, Pietro E

2016-03-01

The objective of this study was to investigate macrolide-resistant Streptococcus agalactiae isolates harbouring erm(TR), an erm(A) gene subclass, with emphasis on their erm(TR)-carrying genetic elements. Four erm(TR)-carrying elements have been described to date: three closely related (ICE10750-RD.2, Tn1806 and ICESp1108) in Streptococcus pyogenes, Streptococcus pneumoniae and S. pyogenes, respectively; and one completely different (IMESp2907, embedded in ICESp2906 to form ICESp2905) in S. pyogenes. Seventeen macrolide-resistant erm(TR)-positive S. agalactiae isolates were phenotypically and genotypically characterized. Their erm(TR)-carrying elements were explored by analysing the distinctive recombination genes of known erm(TR)-carrying integrative and conjugative elements (ICEs) and by PCR mapping. The new genetic context and organization of IMESp2907 in S. agalactiae were explored using several experimental procedures and in silico analyses. Five isolates harboured ICE10750-RD.2/Tn1806, five isolates harboured ICESp1108 and five isolates bore unknown erm(TR)-carrying elements. The remaining two isolates, exhibiting identical serotypes and pulsotypes, harboured IMESp2907 in a new genetic environment, which was further investigated in one of the two isolates, SagTR7. IMESp2907 was circularizable in S. agalactiae, as described in S. pyogenes. The new IMESp2907 junctions were identified based on its site-specific integration; the att sites were almost identical to those in S. pyogenes. In strain SagTR7, erm(TR)-carrying IMESp2907 was embedded in an erm(TR)-less internal element related to ICE10750-RD.2/Tn1806, which, in turn, was embedded in an ICESde3396-like element. The resulting whole ICE, ICESagTR7 (∼129 kb), was integrated into the chromosome downstream of the rplL gene, and was excisable in circular form and transferable by conjugation. This is the first study exploring erm(TR)-carrying genetic elements in S. agalactiae. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

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

PubMed

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.

Two zinc-binding domains in the transporter AdcA from Streptococcus pyogenes facilitate high-affinity binding and fast transport of zinc.

PubMed

Cao, Kun; Li, Nan; Wang, Hongcui; Cao, Xin; He, Jiaojiao; Zhang, Bing; He, Qing-Yu; Zhang, Gong; Sun, Xuesong

2018-04-20

Zinc is an essential metal in bacteria. One important bacterial zinc transporter is AdcA, and most bacteria possess AdcA homologs that are single-domain small proteins due to better efficiency of protein biogenesis. However, a double-domain AdcA with two zinc-binding sites is significantly overrepresented in Streptococcus species, many of which are major human pathogens. Using molecular simulation and experimental validations of AdcA from Streptococcus pyogenes , we found here that the two AdcA domains sequentially stabilize the structure upon zinc binding, indicating an organization required for both increased zinc affinity and transfer speed. This structural organization appears to endow Streptococcus species with distinct advantages in zinc-depleted environments, which would not be achieved by each single AdcA domain alone. This enhanced zinc transport mechanism sheds light on the significance of the evolution of the AdcA domain fusion, provides new insights into double-domain transporter proteins with two binding sites for the same ion, and indicates a potential target of antimicrobial drugs against pathogenic Streptococcus species. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Severe invasive streptococcal infection by Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis.

PubMed

Watanabe, Shinya; Takemoto, Norihiko; Ogura, Kohei; Miyoshi-Akiyama, Tohru

2016-01-01

Streptococcus pyogenes, a group A Streptococcus (GAS), has been recognized as the causative pathogen in patients with severe invasive streptococcal infection with or without necrotizing fasciitis. In recent epidemiological studies, Streptococcus dysgalactiae subsp. equisimilis (SDSE) has been isolated from severe invasive streptococcal infection. Complete genome sequence showed that SDSE is the closest bacterial species to GAS, with approximately 70% of genome coverage. SDSE, however, lacks several key virulence factors present in GAS, such as SPE-B, the hyaluronan synthesis operon and active superantigen against human immune cells. A key event in the ability of GAS to cause severe invasive streptococcal infection was shown to be the acquisition of novel genetic traits such as phages. Strikingly, however, during severe invasive infection, GAS destroys its own covRS two-component system, which negatively regulates many virulence factor genes, resulting in a hyper-virulent phenotype. In contrast, this phenomenon has not been observed in SDSE. The present review describes the epidemiology of severe invasive streptococcal infection and the detailed pathogenic mechanisms of GAS and SDSE, emphasizing findings from their genome sequences and analyses of gene expression. © 2015 The Societies and John Wiley & Sons Australia, Ltd.

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

PubMed Central

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

2012-01-01

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

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

PubMed Central

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

2013-01-01

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

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

PubMed Central

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

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

PubMed

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

2014-07-21

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

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

PubMed

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

2016-01-01

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ku, Min-Je; Lee, Won-Ho; Biotechnology and Genetic Engineering, Korea University, Seoul 136-701

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. Themore » 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%.« less

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

PubMed Central

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

2012-01-01

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

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

PubMed

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.

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

PubMed Central

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

Molecular modeling on streptolysin-O of multidrug resistant Streptococcus pyogenes and computer aided screening and in vitro assay for novel herbal inhibitors.

PubMed

Skariyachan, Sinosh; Narayan, Naik Sowmyalaxmi; Aggimath, Tejaswini S; Nagaraj, Sushmitha; Reddy, Monika S; Narayanappa, Rajeswari

2014-03-01

Streptococcus pyogenes is a notorious pathogenic bacterium which causes various human diseases ranging from localized infections to life threatening invasive diseases. Streptolysin-O (SLO), pore-forming thiol-activated cytolysin, is the major virulent factor for streptococcal infections. Present therapies against streptococcal infections are limited as most of the strains have developed multi-drug resistance to present generation of drugs. Hence, there is a need for alternative therapeutic substances. Structure based virtual screening is a novel platform to select lead molecules with better pharmacokinetic properties. The 3D structure of SLO (not available in native form), essential for such studies, was computationally generated and this homology model was used as probable drug target. Based on literature survey, several phytoligands from 25 medicinal plants were selected. Out of these, leads from 11 plants showed better pharmacokinetic properties. The best lead molecules were screened based on computer aided drug likeness and pharmacokinetic predictions. The inhibitory properties of selected herbal leads against SLO were studied by molecular docking. An in vitro assay was further carried out and variations observed were found to be significant (p<0.05). Antibiotic sensitivity testing was also performed with the clinical strain of Streptococcus pyogenes with conventional drugs. The clinical strain showed multi-drug resistance to conventional drugs. Our study revealed that numerous phytoligands have better inhibitory properties towards the toxin. We noticed that incorporation of selected herbal extracts in blood agar medium showed significant reduction in hemolysis (MIC 300μl/plate), indicating inhibition of SLO. Furthermore, the butanol extracts of selected herbal preparation based on computer aided screening showed significant inhibitory properties at 250 mcg/disc concentration. We also noticed that selected herbal formulations have better antimicrobial properties at MIC range of 300- 400μl. Hence, our study suggests that these herbal extracts have better inhibitory properties against the toxin as well as drug resistant Streptococcus pyogenes.

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

PubMed Central

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

2014-01-01

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

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

PubMed

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.

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

PubMed Central

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

2016-01-01

ABSTRACT 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. IMPORTANCE 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 findings provide new insights into the function of TCSs in S. pyogenes. PMID:27474716

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

PubMed

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 findings provide new insights into the function of TCSs in S. pyogenes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Differentiation of Streptococcus pneumoniae Conjunctivitis Outbreak Isolates by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry▿

PubMed Central

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.

2008-01-01

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. PMID:18708515

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

PubMed Central

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

2016-01-01

Streptococcus pyogenes is a human commensal and a bacterial pathogen responsible for a wide variety of human diseases differing in symptoms, severity, and tissue tropism. The completed genome sequences of >37 strains of S. pyogenes, representing diverse disease-causing serotypes, have been published. The greatest genetic variation among these strains is attributed to numerous integrated prophage and prophage-like elements, encoding several virulence factors. A comparison of isogenic strains, differing in prophage content, would reveal the effects of these elements on streptococcal pathogenesis. However, curing strains of prophage is often difficult and sometimes unattainable. We have applied a novel counter-selection approach to identify rare S. pyogenes mutants spontaneously cured of select prophage. To accomplish this, we first inserted a two-gene cassette containing a gene for kanamycin resistance (KanR) and the rpsL wild-type gene, responsible for dominant streptomycin sensitivity (SmS), into a targeted prophage on the chromosome of a streptomycin resistant (SmR) mutant of S. pyogenes strain SF370. We then applied antibiotic counter-selection for the re-establishment of the KanS/SmR phenotype to select for isolates cured of targeted prophage. This methodology allowed for the precise selection of spontaneous phage loss and restoration of the natural phage attB attachment sites for all four prophage-like elements in this S. pyogenes chromosome. Overall, 15 mutants were constructed that encompassed every permutation of phage knockout as well as a mutant strain, named CEM1ΔΦ, completely cured of all bacteriophage elements (a ~10% loss of the genome); the only reported S. pyogenes strain free of prophage-like elements. We compared CEM1ΔΦ to the WT strain by analyzing differences in secreted DNase activity, as well as lytic and lysogenic potential. These mutant strains should allow for the direct examination of bacteriophage relationships within S. pyogenes and further elucidate how the presence of prophage may affect overall streptococcal survival, pathogenicity, and evolution. PMID:26756207

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

PubMed

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

2012-07-01

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.

Targeted quantitative analysis of Streptococcus pyogenes virulence factors by multiple reaction monitoring.

PubMed

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

2008-08-01

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

Pyogenic Pericarditis and Cardiac Tamponade Due to Streptococcus anginosus in a Combat Theater.

PubMed

Maves, Ryan C; Tripp, Michael S; Franzos, Tracy; Wallace, Scott C; Drinkwine, Benjamin J; Villines, Todd C

2017-01-01

Streptococcus anginosus group pericarditis is rare. A 24-year-old male soldier presented for care at a military clinic in Afghanistan with shock and cardiac tamponade requiring emergent pericardial drainage and aeromedical evacuation. We review the patient's case, the need for serial pericardial drainage, and the available literature on this disorder.

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

PubMed Central

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

2016-01-01

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

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

PubMed Central

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

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

PubMed Central

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

2013-01-01

Streptococcus anginosus is a member of the anginosus group streptococci, which form part of the normal human oral flora. In contrast to the pyogenic group streptococci, our knowledge of the virulence factors of the anginosus group streptococci, including S. anginosus, is not sufficient to allow a clear understanding of the basis of their pathogenicity. Generally, hemolysins are thought to be important virulence factors in streptococcal infections. In the present study, a sag operon homologue was shown to be responsible for beta-hemolysis in S. anginosus strains by random gene knockout. Interestingly, contrary to pyogenic group streptococci, beta-hemolytic S. anginosus was shown to have two tandem sagA homologues, encoding streptolysin S (SLS)-like peptides, in the sag operon homologue. Gene deletion and complementation experiments revealed that both genes were functional, and these SLS-like peptides were essential for beta-hemolysis in beta-hemolytic S. anginosus. Furthermore, the amino acid sequence of these SLS-like peptides differed from that of the typical SLS of S. pyogenes, especially in their propeptide domain, and an amino acid residue indicated to be important for the cytolytic activity of SLS in S. pyogenes was deleted in both S. anginosus homologues. These data suggest that SLS-like peptides encoded by two sagA homologues in beta-hemolytic S. anginosus may be potential virulence factors with a different structure essential for hemolytic activity and/or the maturation process compared to the typical SLS present in pyogenic group streptococci. PMID:23292771

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

PubMed

Wong, Samson Sy; Yuen, Kwok-Yung

2012-07-01

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

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

PubMed Central

Wong, Samson SY; Yuen, Kwok-Yung

2012-01-01

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

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

PubMed

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

1991-02-01

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

Evolutionary Constraints Shaping Streptococcus pyogenes-Host Interactions.

PubMed

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.

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

PubMed Central

HAMADA, Shigeyuki; KAWABATA, Shigetada; NAKAGAWA, Ichiro

2015-01-01

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

A hospital-based study to evaluate the incidence pattern of group A streptococcal throat infections from different age group patients.

PubMed

Ray, Dipanwita; Banerjee, Surajita; Bhattacharya, Sujata; Sinha, Sukanta; Bandyopadhyay, Debasis; Ghosal, Chaitry; Gupta, Siddhartha; Majumdar, Pallav Kumar; Saha, Somnath; Gupta, Soma; Bhattacharya, Basudev

2010-02-01

Streptococcus pyogenes(group A) is a major pathogen capable of causing a wide range of diseases in different age group of people. In this study 100 patients were selected who presented with the complaint of sore throat. All the patients were divided in four age groups. Streptococcus pyogenes colonies were confirmed on the basis of beta-haemolysis, bacitracin sensitivity test, and latex agglutination test for group A. Out of a total of 100 samples, 42 were confirmed as group A streptococcus. From this study, it has been observed that all age groups, with maximum occurrence in 5-15 years age group, were suffering from group A streptococcal pharyngitis. Therefore every case of sore throat especially affecting children should be investigated to detect the causative agent for initiation of proper therapy so that the more serious outcome like acute rheumatic fever (ARF) and acute glomerulonephritis (AGN) can be prevented.

Crystal structure of SP-PTP, a low molecular weight protein tyrosine phosphatase from Streptococcus pyogenes.

PubMed

Ku, Bonsu; Keum, Chae Won; Lee, Hye Seon; Yun, Hye-Yeoung; Shin, Ho-Chul; Kim, Bo Yeon; Kim, Seung Jun

2016-09-23

Streptococcus pyogenes, or Group A Streptococcus (GAS), is a pathogenic bacterium that causes a variety of infectious diseases. The GAS genome encodes one protein tyrosine phosphatase, SP-PTP, which plays an essential role in the replication and virulence maintenance of GAS. Herein, we present the crystal structure of SP-PTP at 1.9 Å resolution. Although SP-PTP has been reported to have dual phosphatase specificity for both phosphorylated tyrosine and serine/threonine, three-dimensional structural analysis showed that SP-PTP shares high similarity with typical low molecular weight protein tyrosine phosphatases (LMWPTPs), which are specific for phosphotyrosine, but not with dual-specificity phosphatases, in overall folding and active site composition. In the dephosphorylation activity test, SP-PTP consistently acted on phosphotyrosine substrates, but not or only minimally on phosphoserine/phosphothreonine substrates. Collectively, our structural and biochemical analyses verified SP-PTP as a canonical tyrosine-specific LMWPTP. Copyright © 2016 Elsevier Inc. All rights reserved.

An Outbreak of Streptococcus pyogenes in a Mental Health Facility: Advantage of Well-Timed Whole-Genome Sequencing Over emm Typing.

PubMed

Bergin, Sarah M; Periaswamy, Balamurugan; Barkham, Timothy; Chua, Hong Choon; Mok, Yee Ming; Fung, Daniel Shuen Sheng; Su, Alex Hsin Chuan; Lee, Yen Ling; Chua, Ming Lai Ivan; Ng, Poh Yong; Soon, Wei Jia Wendy; Chu, Collins Wenhan; Tan, Siyun Lucinda; Meehan, Mary; Ang, Brenda Sze Peng; Leo, Yee Sin; Holden, Matthew T G; De, Partha; Hsu, Li Yang; Chen, Swaine L; de Sessions, Paola Florez; Marimuthu, Kalisvar

2018-05-09

OBJECTIVEWe report the utility of whole-genome sequencing (WGS) conducted in a clinically relevant time frame (ie, sufficient for guiding management decision), in managing a Streptococcus pyogenes outbreak, and present a comparison of its performance with emm typing.SETTINGA 2,000-bed tertiary-care psychiatric hospital.METHODSActive surveillance was conducted to identify new cases of S. pyogenes. WGS guided targeted epidemiological investigations, and infection control measures were implemented. Single-nucleotide polymorphism (SNP)-based genome phylogeny, emm typing, and multilocus sequence typing (MLST) were performed. We compared the ability of WGS and emm typing to correctly identify person-to-person transmission and to guide the management of the outbreak.RESULTSThe study included 204 patients and 152 staff. We identified 35 patients and 2 staff members with S. pyogenes. WGS revealed polyclonal S. pyogenes infections with 3 genetically distinct phylogenetic clusters (C1-C3). Cluster C1 isolates were all emm type 4, sequence type 915 and had pairwise SNP differences of 0-5, which suggested recent person-to-person transmissions. Epidemiological investigation revealed that cluster C1 was mediated by dermal colonization and transmission of S. pyogenes in a male residential ward. Clusters C2 and C3 were genomically diverse, with pairwise SNP differences of 21-45 and 26-58, and emm 11 and mostly emm120, respectively. Clusters C2 and C3, which may have been considered person-to-person transmissions by emm typing, were shown by WGS to be unlikely by integrating pairwise SNP differences with epidemiology.CONCLUSIONSWGS had higher resolution than emm typing in identifying clusters with recent and ongoing person-to-person transmissions, which allowed implementation of targeted intervention to control the outbreak.Infect Control Hosp Epidemiol 2018;1-9.

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

PubMed

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.

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

PubMed Central

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

2013-01-01

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

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

PubMed

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.

Pyogenic Pericarditis and Cardiac Tamponade Due to Streptococcus anginosus in a Combat Theater

PubMed Central

Tripp, Michael S.; Franzos, Tracy; Wallace, Scott C.; Drinkwine, Benjamin J.; Villines, Todd C.

2017-01-01

Abstract Streptococcus anginosus group pericarditis is rare. A 24-year-old male soldier presented for care at a military clinic in Afghanistan with shock and cardiac tamponade requiring emergent pericardial drainage and aeromedical evacuation. We review the patient’s case, the need for serial pericardial drainage, and the available literature on this disorder. PMID:28470013

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

PubMed Central

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

2015-01-01

We applied an emm cluster typing system to group A Streptococcus strains in New Zealand, including those associated with acute rheumatic fever (ARF). We observed few so-called rheumatogenic emm types but found a high proportion of emm types previously associated with pyoderma, further suggesting a role for skin infection in ARF. PMID:26292296

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

PubMed

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

2016-07-01

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

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

PubMed

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

2016-01-05

CRISPRs and Cas proteins constitute an RNA-guided microbial immune system against invading nucleic acids. Cas1 is a universal Cas protein found in all three types of CRISPR-Cas systems, and its role is implicated in new spacer acquisition during CRISPR-mediated adaptive immunity. Here, we report the crystal structure of Streptococcus pyogenes Cas1 (SpCas1) in a type II CRISPR-Cas system and characterize its interaction with S. pyogenes Csn2 (SpCsn2). The SpCas1 structure reveals a unique conformational state distinct from type I Cas1 structures, resulting in a more extensive dimerization interface, a more globular overall structure, and a disruption of potential metal-binding sites for catalysis. We demonstrate that SpCas1 directly interacts with SpCsn2, and identify the binding interface and key residues for Cas complex formation. These results provide structural information for a type II Cas1 protein, and lay a foundation for studying multiprotein Cas complexes functioning in type II CRISPR-Cas systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Streptococcus pyogenes collagen type I-binding Cpa surface protein. Expression profile, binding characteristics, biological functions, and potential clinical impact.

PubMed

Kreikemeyer, Bernd; Nakata, Masanobu; Oehmcke, Sonja; Gschwendtner, Caroline; Normann, Jana; Podbielski, Andreas

2005-09-30

The Streptococcus pyogenes collagen type I-binding protein Cpa (collagen-binding protein of group A streptococci) expressed by 28 serotypes of group A streptococci has been extensively characterized at the gene and protein levels. Evidence for three distinct families of cpa genes was found, all of which shared a common sequence encoding a 60-amino acid domain that accounted for selective binding to type I collagen. Surface plasmon resonance-based affinity measurements and functional studies indicated that the expression of Cpa was consistent with an attachment role for bacteria to tissue containing collagen type I. A cpa mutant displayed a significantly decreased internalization rate when incubated with HEp-2 cells but had no effect on the host cell viability. By utilizing serum from patients with a positive titer for streptolysin/DNase antibody, an increased anti-Cpa antibody titer was noted for patients with a clinical history of arthritis or osteomyelitis. Taken together, these results suggest Cpa may be a relevant matrix adhesin contributing to the pathogenesis of S. pyogenes infection of bones and joints.

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

PubMed

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

2008-12-31

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

Complete Genome Sequence and Comparative Genomics of a Streptococcus pyogenes emm3 Strain M3-b isolated from a Japanese Patient with Streptococcal Toxic Shock Syndrome.

PubMed

Ogura, Kohei; Watanabe, Shinya; Kirikae, Teruo; Miyoshi-Akiyama, Tohru

2017-01-01

Epidemiologic typing of Streptococcus pyogenes (GAS) is frequently based on the genotype of the emm gene, which encodes M/Emm protein. In this study, the complete genome sequence of GAS emm3 strain M3-b, isolated from a patient with streptococcal toxic shock syndrome (STSS), was determined. This strain exhibited 99% identity with other complete genome sequences of emm3 strains MGAS315, SSI-1, and STAB902. The complete genomes of five additional strains isolated from Japanese patients with and without STSS were also sequences. Maximum-likelihood phylogenetic analysis showed that strains M3-b, M3-e, and SSI-1, all which were isolated from STSS patients, were relatively close.

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

PubMed

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.

Detection of strep throat causing bacterium directly from medical swabs by touch spray-mass spectrometry.

PubMed

Jarmusch, Alan K; Pirro, Valentina; Kerian, Kevin S; Cooks, R Graham

2014-10-07

Strep throat causing Streptococcus pyogenes was detected in vitro and in simulated clinical samples by performing touch spray ionization-mass spectrometry. MS analysis took only seconds to reveal characteristic bacterial and human lipids. Medical swabs were used as the substrate for ambient ionization. This work constitutes the initial step in developing a non-invasive MS-based test for clinical diagnosis of strep throat. It is limited to the single species, S. pyogenes, which is responsible for the vast majority of cases. The method is complementary to and, with further testing, a potential alternative to current methods of point-of-care detection of S. pyogenes.

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

PubMed

Min, Sharon; Ingraham, Karen; Huang, Jianzhong; McCloskey, Lynn; Rilling, Sarah; Windau, Anne; Pizzollo, Jason; Butler, Deborah; Aubart, Kelly; Miller, Linda A; Zalacain, Magdalena; Holmes, David J; O'Dwyer, Karen

2015-08-01

The continuous emergence of multidrug-resistant pathogenic bacteria is compromising the successful treatment of serious microbial infections. GSK1322322, a novel peptide deformylase (PDF) inhibitor, shows good in vitro antibacterial activity and has demonstrated safety and efficacy in human proof-of-concept clinical studies. In vitro studies were performed to determine the frequency of resistance (FoR) to this antimicrobial agent in major pathogens that cause respiratory tract and skin infections. Resistance to GSK1322322 occurred at high frequency through loss-of-function mutations in the formyl-methionyl transferase (FMT) protein in Staphylococcus aureus (4/4 strains) and Streptococcus pyogenes (4/4 strains) and via missense mutations in Streptococcus pneumoniae (6/21 strains), but the mutations were associated with severe in vitro and/or in vivo fitness costs. The overall FoR to GSK1322322 was very low in Haemophilus influenzae, with only one PDF mutant being identified in one of four strains. No target-based mutants were identified from S. pyogenes, and only one or no PDF mutants were isolated in three of the four S. aureus strains studied. In S. pneumoniae, PDF mutants were isolated from only six of 21 strains tested; an additional 10 strains did not yield colonies on GSK1322322-containing plates. Most of the PDF mutants characterized from those three organisms (35/37 mutants) carried mutations in residues at or in close proximity to one of three highly conserved motifs that are part of the active site of the PDF protein, with 30 of the 35 mutations occurring at position V71 (using the S. pneumoniae numbering system). Copyright © 2015, American Society for Microbiology. All Rights Reserved.

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

PubMed Central

Ingraham, Karen; Huang, Jianzhong; McCloskey, Lynn; Rilling, Sarah; Windau, Anne; Pizzollo, Jason; Butler, Deborah; Aubart, Kelly; Miller, Linda A.; Zalacain, Magdalena; Holmes, David J.; O'Dwyer, Karen

2015-01-01

The continuous emergence of multidrug-resistant pathogenic bacteria is compromising the successful treatment of serious microbial infections. GSK1322322, a novel peptide deformylase (PDF) inhibitor, shows good in vitro antibacterial activity and has demonstrated safety and efficacy in human proof-of-concept clinical studies. In vitro studies were performed to determine the frequency of resistance (FoR) to this antimicrobial agent in major pathogens that cause respiratory tract and skin infections. Resistance to GSK1322322 occurred at high frequency through loss-of-function mutations in the formyl-methionyl transferase (FMT) protein in Staphylococcus aureus (4/4 strains) and Streptococcus pyogenes (4/4 strains) and via missense mutations in Streptococcus pneumoniae (6/21 strains), but the mutations were associated with severe in vitro and/or in vivo fitness costs. The overall FoR to GSK1322322 was very low in Haemophilus influenzae, with only one PDF mutant being identified in one of four strains. No target-based mutants were identified from S. pyogenes, and only one or no PDF mutants were isolated in three of the four S. aureus strains studied. In S. pneumoniae, PDF mutants were isolated from only six of 21 strains tested; an additional 10 strains did not yield colonies on GSK1322322-containing plates. Most of the PDF mutants characterized from those three organisms (35/37 mutants) carried mutations in residues at or in close proximity to one of three highly conserved motifs that are part of the active site of the PDF protein, with 30 of the 35 mutations occurring at position V71 (using the S. pneumoniae numbering system). PMID:26014938

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

PubMed

Shafreen, Rajamohmed Beema; Pandian, Shunmugiah Karutha

2013-09-01

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

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

PubMed

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.

Prevalence and molecular diversity of invasive Streptococcus dysgalactiae and Streptococcus pyogenes in a German tertiary care medical centre.

PubMed

Rößler, S; Berner, R; Jacobs, E; Toepfner, N

2018-05-03

Prevalence of invasive ß-haemolytic streptococci (BHS) at a tertiary care hospital and molecular diversity of S. pyogenes and S. dysgalactiae was studied. Between 2012 and 2016, all blood culture sets (n = 55,839), CSF (n = 8413) and soft tissue (n = 20,926) samples were analysed for BHS positivity using HYBASE software. Molecular profiles of 99 S. pyogenes and S. dysgalactiae were identified by sequencing of M protein genes (emm types) and multiplex PCR typing of 20 other virulence determinants. Streptococci contributed to 6.2% of blood, 10.7% of CSF and 14.5% of soft tissue isolates, being among the most common invasive isolates. The overall rates of invasive S. pyogenes, S. agalactiae, S. dysgalactiae and S. pneumoniae were 2.4, 4.4, 2.1, and 5.3%. Whereas S. pneumoniae was 1.5% more common in CSF samples, BHS isolates were 2-fold and 11-fold higher in bacteraemia and invasive soft tissue infections. Genetic BHS typing revealed wide molecular diversity of invasive and noninvasive group A and group G BHS, whereas one emm-type (stG62647.0) and no other virulence determinants except scpA were detected in invasive group C BHS. BHS were important invasive pathogens, outpacing S. pneumoniae in bacteraemia and invasive soft tissue infections. The incidence of S. dysgalactiae infections was comparable to that of S. pyogenes even with less diversity of molecular virulence. The results of this study emphasise the need for awareness of BHS invasiveness in humans and the need to develop BHS prevention strategies.

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.

PubMed

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 support informed prescribing for CA-RTIs and other infections. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

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

PubMed Central

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

2015-01-01

ABSTRACT Infection with Streptococcus pyogenes is associated with a breadth of clinical manifestations ranging from mild pharyngitis to severe necrotizing fasciitis. Elevated levels of intracellular copper are highly toxic to this bacterium, and thus, the microbe must tightly regulate the level of this metal ion by one or more mechanisms, which have, to date, not been clearly defined. In this study, we have identified two virulence mechanisms by which S. pyogenes protects itself against copper toxicity. We defined a set of putative genes, copY (for a regulator), copA (for a P1-type ATPase), and copZ (for a copper chaperone), whose expression is regulated by copper. Our results indicate that these genes are highly conserved among a range of clinical S. pyogenes isolates. The copY, copA, and copZ genes are induced by copper and are transcribed as a single unit. Heterologous expression assays revealed that S. pyogenes CopA can confer copper tolerance in a copper-sensitive Escherichia coli mutant by preventing the accumulation of toxic levels of copper, a finding that is consistent with a role for CopA in copper export. Evaluation of the effect of copper stress on S. pyogenes in a planktonic or biofilm state revealed that biofilms may aid in protection during initial exposure to copper. However, copper stress appears to prevent the shift from the planktonic to the biofilm state. Therefore, our results indicate that S. pyogenes may use several virulence mechanisms, including altered gene expression and a transition to and from planktonic and biofilm states, to promote survival during copper stress. IMPORTANCE Bacterial pathogens encounter multiple stressors at the host-pathogen interface. This study evaluates a virulence mechanism(s) utilized by S. pyogenes to combat copper at sites of infection. A better understanding of pathogen tolerance to stressors such as copper is necessary to determine how host-pathogen interactions impact bacterial survival during infections. These insights may lead to the identification of novel therapeutic targets that can be used to address antibiotic resistance. PMID:26013489

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

PubMed

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 lead to the identification of novel therapeutic targets that can be used to address antibiotic resistance. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Co-Infection of Rickettsia rickettsii and Streptococcus pyogenes: Is Fatal Rocky Mountain Spotted Fever Underdiagnosed?

PubMed Central

Raczniak, Gregory A.; Kato, Cecilia; Chung, Ida H.; Austin, Amy; McQuiston, Jennifer H.; Weis, Erica; Levy, Craig; Carvalho, Maria da Gloria S.; Mitchell, Audrey; Bjork, Adam; Regan, Joanna J.

2014-01-01

Rocky Mountain spotted fever, a tick-borne disease caused by Rickettsia rickettsii, is challenging to diagnose and rapidly fatal if not treated. We describe a decedent who was co-infected with group A β-hemolytic streptococcus and R. rickettsii. Fatal cases of Rocky Mountain spotted fever may be underreported because they present as difficult to diagnose co-infections. PMID:25331804

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

PubMed Central

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

2011-01-01

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

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

PubMed

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

2013-11-01

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

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

PubMed Central

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

Application of a unique server-based oligonucleotide probe selection tool toward a novel biosensor for the detection of Streptococcus pyogenes.

PubMed

Nugen, Sam R; Leonard, Barbara; Baeumner, Antje J

2007-05-15

We developed a software program for the rapid selection of detection probes to be used in nucleic acid-based assays. In comparison to commercially available software packages, our program allows the addition of oligotags as required by nucleic acid sequence-based amplification (NASBA) as well as automatic BLAST searches for all probe/primer pairs. We then demonstrated the usefulness of the program by designing a novel lateral flow biosensor for Streptococcus pyogenes that does not rely on amplification methods such as the polymerase chain reaction (PCR) or NASBA to obtain low limits of detection, but instead uses multiple reporter and capture probes per target sequence and an instantaneous amplification via dye-encapsulating liposomes. These assays will decrease the detection time to just a 20 min hybridization reaction and avoid costly enzymatic gene amplification reactions. The lateral flow assay was developed quantifying the 16S rRNA from S. pyogenes by designing reporter and capture probes that specifically hybridize with the RNA and form a sandwich. DNA reporter probes were tagged with dye-encapsulating liposomes, biotinylated DNA oligonucleotides were used as capture probes. From the initial number of capture and reporter probes chosen, a combination of two capture and three reporter probes were found to provide optimal signal generation and significant enhancement over single capture/reporter probe combinations. The selectivity of the biosensor was proven by analyzing organisms closely related to S. pyogenes, such as other Streptococcus and Enterococcus species. All probes had been selected by the software program within minutes and no iterative optimization and re-design of the oligonucleotides was required which enabled a very rapid biosensor prototyping. While the sensitivity obtained with the biosensor was only 135 ng, future experiments will decrease this significantly by the addition of more reporter and capture probes for either the same rRNA or a different nucleic acid target molecule. This will lead to the possibility of detecting S. pyogenes with a rugged assay that does not require a cell culturing or gene amplification step and will therefore enable rapid, specific and sensitive onsite testing.

Molecular Epidemiology and Genomics of Group A Streptococcus

PubMed Central

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

2014-01-01

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

Postpartum pyogenic sacroiliitis with methicillin-resistant Staphylococcus aureus in a healthy adult: A case report and review of the literature.

PubMed

Imagama, Takashi; Tokushige, Atsunori; Sakka, Akihito; Seki, Kazushige; Taguchi, Toshihiko

2015-06-01

Back and buttock pain during pregnancy and the postpartum period generally improves spontaneously and rarely causes problems. However, such pain is infrequently induced by pyogenic sacroiliitis. We herein present a 37-year-old female patient with no previous medical history who developed pyogenic sacroiliitis with severe right buttock pain 7 days after cesarean delivery. Arthrocentesis was performed, and a culture revealed the presence of methicillin-resistant Staphylococcus aureus (MRSA). After 6 weeks of treatment with intravenous antibiotics, her infection became quiescent. Eight cases of pyogenic sacroiliitis during the postpartum period and seven cases during pregnancy have been reported, but most of the causative pathogens were methicillin-sensitive Staphylococcus or Streptococcus species. This report describes the first case of postpartum pyogenic sacroiliitis caused by MRSA. The frequency of infection with MRSA has recently increased, and community-acquired MRSA, which affects even healthy young people, has also become a problem. Antibiotics for empirical therapy after a diagnosis of pyogenic sacroiliitis, including anti-MRSA antibiotics, should be carefully selected. Copyright © 2015. Published by Elsevier B.V.

The Regulatory Small RNA MarS Supports Virulence of Streptococcus pyogenes.

PubMed

Pappesch, Roberto; Warnke, Philipp; Mikkat, Stefan; Normann, Jana; Wisniewska-Kucper, Aleksandra; Huschka, Franziska; Wittmann, Maja; Khani, Afsaneh; Schwengers, Oliver; Oehmcke-Hecht, Sonja; Hain, Torsten; Kreikemeyer, Bernd; Patenge, Nadja

2017-09-25

Small regulatory RNAs (sRNAs) play a role in the control of bacterial virulence gene expression. In this study, we investigated an sRNA that was identified in Streptococcus pyogenes (group A Streptococcus, GAS) but is conserved throughout various streptococci. In a deletion strain, expression of mga, the gene encoding the multiple virulence gene regulator, was reduced. Accordingly, transcript and proteome analyses revealed decreased expression of several Mga-activated genes. Therefore, and because the sRNA was shown to interact with the 5' UTR of the mga transcript in a gel-shift assay, we designated it MarS for m ga-activating regulatory sRNA. Down-regulation of important virulence factors, including the antiphagocytic M-protein, led to increased susceptibility of the deletion strain to phagocytosis and reduced adherence to human keratinocytes. In a mouse infection model, the marS deletion mutant showed reduced dissemination to the liver, kidney, and spleen. Additionally, deletion of marS led to increased tolerance towards oxidative stress. Our in vitro and in vivo results indicate a modulating effect of MarS on virulence gene expression and on the pathogenic potential of GAS.

[Streptococcus pyogenes and the brain: living with the enemy].

PubMed

Dale, R C

Streptococcus pyogenes (or group A beta hemolytic streptococcus) is a pathogenic bacterium that can give rise to a range of invasive and autoimmune diseases, although it is more widely known as the cause of tonsillitis. It is particularly interesting to note that this germ only causes disease in humans. For many years it has been acknowledged that it can cause an autoimmune brain disease (Sydenham s chorea). Yet, the spectrum of post streptococcal brain disorders has recently been extended to include other movement disorders such as tics or dystonia. A number of systematic psychiatric studies have shown that certain emotional disorders generally accompany the movement disorder (particularly, obsessive compulsive disorder). The proposed pathogenetic mechanism is that of a neuronal dysfunction in which antibodies play a mediating role. The antibodies that are produced after the streptococcal infection cross react with neuronal proteins, and more especially so in individuals with a propensity. This represents a possible model of immunological mimicry and its potential importance with respect to certain idiopathic disorders such as Tourette syndrome and obsessive compulsive disorder.

Detection of strep throat causing bacterium directly from medical swabs by touch spray - mass spectrometry

PubMed Central

Jarmusch, Alan K.; Pirro, Valentina; Kerian, Kevin S.; Cooks, Graham

2014-01-01

Strep throat causing Streptococcus pyogenes was detected in vitro and in simulated clinical samples by performing touch spray ionization - mass spectrometry. MS analysis took only seconds to reveal characteristic bacterial and human lipids. Medical swabs were used as the substrate for ambient ionization. This work constitutes the initial step in developing a noninvasive MS-based test for clinical diagnosis of strep throat. It is limited to the single species, S. pyogenes, which is responsible for the vast majority of cases. The method is complementary to and, with further testing, a potential alternative to current methods of point-of-care detection of S. pyogenes. PMID:25102079

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

NASA Astrophysics Data System (ADS)

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

2014-11-01

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

Characterization of consecutive Streptococcus pyogenes isolates from patients with pharyngitis and bacteriological treatment failure: special reference to prtF1 and sic / drs.

PubMed

Brandt, C M; Allerberger, F; Spellerberg, B; Holland, R; Lütticken, R; Haase, G

2001-02-15

To analyze bacteriological treatment failure in streptococcal pharyngitis, 40 consecutive Streptococcus pyogenes isolates from 18 patients were characterized. For 17 patients, isolates were indistinguishable with respect to emm type, random amplified polymorphic DNA pattern, and presence of prtF1 encoding the fibronectin-binding protein F1. prtF1 was detected only in the 11 isolates (4 patients) with emm12 and in the single isolate with emm6. Further analysis by vir(mga) regulon typing, sequencing of sic encoding the streptococcal inhibitor of complement from 19 isolates with emm1 (9 patients), and sequencing of drs (distantly related sic) from 11 isolates with emm12 revealed distinct sic alleles with insertions and/or deletions in sic that corresponded to differences in restriction patterns of the vir(mga) regulon only for paired isolates of 2 patients. Among isolates with emm12, 2 novel drs alleles were found. Analysis of these data suggests that neither the presence of prtF1 nor the diversification of sic / drs is required for the persistence of S. pyogenes in pharyngitis.

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

PubMed

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

2016-01-01

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

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

PubMed

Gustafsson, Mattias C U; Lannergård, Jonas; Nilsson, O Rickard; 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.

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

PubMed

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.

Distribution of small native plasmids in Streptococcus pyogenes in India.

PubMed

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

2014-05-01

Complete characterization of a Streptococcus pyogenes population from a defined geographic region comprises information on the plasmids that circulate in these bacteria. Therefore, we determined the distribution of small plasmids (<5kb) in a collection of 279 S. pyogenes isolates from India, where diversity of strains and incidence rates of S. pyogenes infections are high. The collection comprised 77 emm-types. For plasmid detection and discrimination, we developed PCRs for different plasmid replication initiation protein genes, the putative repressor gene copG and bacteriocin genes dysA and scnM57. Plasmid distribution was limited to 13 emm-types. Co-detection analysis using aforementioned PCRs revealed four distinct plasmid sub-types, two of which were previously unknown. Representative plasmids pA852 and pA996 of the two uncharacterized plasmid sub-types were sequenced. These two plasmids could be assigned to the pMV158 and the pC194/pUB110 family of rolling-circle plasmids, respectively. The majority of small plasmids found in India belonged to the two newly characterized sub-types, with pA852- and pA996-like plasmids amounting to 42% and 22% of all detected plasmids, respectively. None of the detected plasmids coded for a known antibiotic resistance gene. Instead, all of the four plasmid sub-types carried known or potential bacteriocin genes. These genes may have influence on the evolutionary success of certain S. pyogenes genotypes. Notably, pA852-like plasmids were found in all isolates of the most prevalent emm-type 11.0. Together, a priori fitness of this genotype and increased fitness due to the acquired plasmids may have rendered type emm11.0 successful and caused the prevalence of pA852-like plasmids in India. Copyright © 2013 Elsevier GmbH. All rights reserved.

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

PubMed

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

2013-05-31

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

Long-term survival of Streptococcus pyogenes in rich media is pH-dependent

PubMed Central

McShan, William M.

2012-01-01

The mechanisms that allow Streptococcus pyogenes to survive and persist in the human host, often in spite of antibiotic therapy, remain poorly characterized. Therefore, the determination of culture conditions for long-term studies is crucial to advancement in this field. Stationary cultures of S. pyogenes strain NZ131 and its spontaneous small-colony variant OK171 were found to survive in rich medium for less than 2 weeks, and this inability to survive resulted from the acidification of the medium to below pH 5.5, which the cells did not tolerate for longer than 6–7 days. The growth of NZ131 resulted in acidification of the culture to below pH 5.5 by the onset of stationary phase, and the loss of viability occurred in a linear fashion. These results were also found to be true for M49 strain CS101 and for M1 strain SF370. The S. pyogenes strains could be protected from killing by the addition of a buffer that stabilized the pH of the medium at pH 6.5, ensuring bacterial survival to at least 70 days. By contrast, increasing the glucose added to the medium accelerated the loss of culture viability in strain NZ131 but not OK171, suggesting that the small-colony variant is altered in glucose uptake or metabolism. Similarly, acidification of the medium prior to inoculation or at the middle of exponential phase resulted in growth inhibition of all strains. These results suggest that control of the pH is crucial for establishing long-term cultures of S. pyogenes. PMID:22361943

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

PubMed Central

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

2013-01-01

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

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

PubMed

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

2015-01-01

Streptococcus pyogenes is the main causative pathogen of recurrent tonsillitis. Histologically, lesions of recurrent tonsillitis contain numerous plasma cells. Strep A is an antigenic carbohydrate molecule on the cell wall of S. pyogenes. As expected, plasma cells in subjects with recurrent tonsillitis secrete antibodies against Strep A. The enzyme-labeled antigen method is a novel histochemical technique that visualizes specific antibody-producing cells in tissue sections by employing a biotin-labeled antigen as a probe. The purpose of the present study was to visualize plasma cells producing antibodies reactive with Strep A in recurrent tonsillitis. Firstly, the lymph nodes of rats immunized with boiled S. pyogenes were paraformaldehyde-fixed and specific plasma cells localized in frozen sections with biotinylated Strep A. Secondly, an enzyme-labeled antigen method was used on human tonsil surgically removed from 12 patients with recurrent tonsillitis. S. pyogenes genomes were PCR-detected in all 12 specimens. The emm genotypes belonged to emm12 in nine specimens and emm1 in three. Plasma cells producing anti-Strep A antibodies were demonstrated in prefixed frozen sections of rat lymph nodes, 8/12 human specimens from patients with recurrent tonsillitis but not in two control tonsils. In human tonsils, Strep A-reactive plasma cells were observed within the reticular squamous mucosa and just below the mucosa, and the specific antibodies belonged to either IgA or IgG classes. Our technique is effective in visualizing immunocytes producing specific antibodies against the bacterial carbohydrate antigen, and is thus a novel histochemical tool for analyzing immune reactions in infectious disorders. © 2014 The Authors. Microbiology and Immunology Published by The Societies and Wiley Publishing Asia Pty Ltd.

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.

PubMed

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.

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

PubMed

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.

Antimicrobial activity of wild mushroom extracts against clinical isolates resistant to different antibiotics.

PubMed

Alves, M J; Ferreira, I C F R; Martins, A; Pintado, M

2012-08-01

This work aimed to screen the antimicrobial activity of aqueous methanolic extracts of 13 mushroom species, collected in Bragança, against several clinical isolates obtained in Hospital Center of Trás-os-Montes and Alto Douro, Portugal. Microdilution method was used to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). MIC results showed that Russula delica and Fistulina hepatica extracts inhibited the growth of gram-negative (Escherichia coli, Morganella morganni and Pasteurella multocida) and gram-positive (Staphylococcus aureus, MRSA, Enterococcus faecalis, Listeria monocytogenes, Streptococcus agalactiae and Streptococcus pyogenes) bacteria. A bactericide effect of both extracts was observed in Past. multocida, Strep. agalactiae and Strep. pyogenes with MBC of 20, 10 and 5 mg ml⁻¹, respectively. Lepista nuda extract exhibited a bactericide effect upon Past. multocida at 5 mg ml⁻¹ and inhibited Proteus mirabilis at 20 mg ml⁻¹. Ramaria botrytis extract showed activity against Enterococcus faecalis and L. monocytogenes, being bactericide for Past. multocida, Strep. agalactiae (MBCs 20 mg ml⁻¹) and Strep. pyogenes (MBC 10 mg ml⁻¹). Leucopaxillus giganteus extract inhibited the growth of E. coli and Pr. mirabilis, being bactericide for Past. multocida, Strep. pyogenes and Strep. agalactiae. Fistulina hepatica, R. botrytis and R. delica are the most promising species as antimicrobial agents. Mushroom extracts could be an alternative as antimicrobials against pathogenic micro-organisms resistant to conventional treatments. © 2012The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Circulating polymerase chain reaction chips utilizing multiple-membrane activation

NASA Astrophysics Data System (ADS)

Wang, Chih-Hao; Chen, Yi-Yu; Liao, Chia-Sheng; Hsieh, Tsung-Min; Luo, Ching-Hsing; Wu, Jiunn-Jong; Lee, Huei-Huang; Lee, Gwo-Bin

2007-02-01

This paper reports a new micromachined, circulating, polymerase chain reaction (PCR) chip for nucleic acid amplification. The PCR chip is comprised of a microthermal control module and a polydimethylsiloxane (PDMS)-based microfluidic control module. The microthermal control modules are formed with three individual heating and temperature-sensing sections, each modulating a specific set temperature for denaturation, annealing and extension processes, respectively. Micro-pneumatic valves and multiple-membrane activations are used to form the microfluidic control module to transport sample fluids through three reaction regions. Compared with other PCR chips, the new chip is more compact in size, requires less time for heating and cooling processes, and has the capability to randomly adjust time ratios and cycle numbers depending on the PCR process. Experimental results showed that detection genes for two pathogens, Streptococcus pyogenes (S. pyogenes, 777 bps) and Streptococcus pneumoniae (S. pneumoniae, 273 bps), can be successfully amplified using the new circulating PCR chip. The minimum number of thermal cycles to amplify the DNA-based S. pyogenes for slab gel electrophoresis is 20 cycles with an initial concentration of 42.5 pg µl-1. Experimental data also revealed that a high reproducibility up to 98% could be achieved if the initial template concentration of the S. pyogenes was higher than 4 pg µl-1. The preliminary results of the current paper were presented at the 19th IEEE International Conference on Micro Electro Mechanical Systems (IEEE MEMS 2006), Istanbul, Turkey, 22-26 January, 2006.

Thermoregulation of Capsule Production by Streptococcus pyogenes

PubMed Central

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

2012-01-01

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

An Ineffective Differential Diagnosis of Infective Endocarditis and Rheumatic Heart Disease after Streptococcal Skin and Soft Tissue Infection.

PubMed

Suzuki, Tetsuya; Mawatari, Momoko; Iizuka, Toshihiko; Amano, Tatsuya; Kutsuna, Satoshi; Fujiya, Yoshihiro; Takeshita, Nozomi; Hayakawa, Kayoko; Ohmagari, Norio

2017-09-01

We herein report the case of a 68-year-old woman with a skin and soft tissue infection at her extremities. The blood culture results were positive for Streptococcus pyogenes, and we started treatment using ampicillin and clindamycin, although subsequent auscultation revealed a new-onset heart murmur. We therefore suspected rheumatic heart disease and infective endocarditis. The case met both the Jones criteria and the modified Duke criteria. Transesophageal echocardiography revealed vegetation on the aortic valve, although the pathological findings were also compatible with both rheumatic heart disease and infective endocarditis. The present findings suggest that these two diseases can coexist in some cases.

An Ineffective Differential Diagnosis of Infective Endocarditis and Rheumatic Heart Disease after Streptococcal Skin and Soft Tissue Infection

PubMed Central

Suzuki, Tetsuya; Mawatari, Momoko; Iizuka, Toshihiko; Amano, Tatsuya; Kutsuna, Satoshi; Fujiya, Yoshihiro; Takeshita, Nozomi; Hayakawa, Kayoko; Ohmagari, Norio

2017-01-01

We herein report the case of a 68-year-old woman with a skin and soft tissue infection at her extremities. The blood culture results were positive for Streptococcus pyogenes, and we started treatment using ampicillin and clindamycin, although subsequent auscultation revealed a new-onset heart murmur. We therefore suspected rheumatic heart disease and infective endocarditis. The case met both the Jones criteria and the modified Duke criteria. Transesophageal echocardiography revealed vegetation on the aortic valve, although the pathological findings were also compatible with both rheumatic heart disease and infective endocarditis. The present findings suggest that these two diseases can coexist in some cases. PMID:28794364

Influenza-like Illness Surveillance on the California-Mexico Border, 2004-2009

DTIC Science & Technology

2011-01-01

common in all age groups, causing both hospital- and community - acquired epidemics. AdV probably accounts for 3% of the infections in the civilian...enterovirus, herpes simplex virus, Streptococcus pneumoniae , and Streptococcus pyogenes. Conclusions The US-Mexico border is one of the busiest in...countries where ARIs are the cause of up to 25% of all pediatric deaths.3 In Mexico, ARIs are the leading cause of disease (http://www.dged

[Toxic shock syndrome caused by pyogenic bacteria].

PubMed

Gábor, Zsuzsa; Szekeres, Sándor; Gacs, Mária

2003-01-12

Case reports and review of the literature. Severe toxic shock syndrome caused by invasive infection with pyogenic bacteria Staphylococcus aureus or group A Streptococcus pyogenes, with high mortality rates in cases of the latter, remained one of the most problematic chapters of critical care medicine to date. To give an overview on the epidemiology, clinical manifestations, the complex therapeutical approaches of the syndrome and, on the role and mechanisms of action of bacterial superantigens in the pathophysiological processes as well. Literary data, and some illustrative selected cases demonstrate that, the incidence of TSS shows increasing tendency worldwide and, that otherwise healthy, younger people are the most frequently affected. As for prognosis: early diagnosis and treatment with sufficient radicality are of decisive importance.

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

PubMed

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.

Mixed community-acquired pneumonia in hospitalised patients.

PubMed

de Roux, A; Ewig, S; García, E; Marcos, M A; Mensa, J; Lode, H; Torres, A

2006-04-01

The role of mixed community-acquired pneumonia (CAP) is controversial. The aim of the present study was to determine the incidence, principal microbial patterns, clinical predictors and course of mixed CAP. The current study included 1,511 consecutive hospitalised patients with CAP. Of these, 610 (40%) patients had an established aetiology. One pathogen was demonstrated in 528 patients and 82 (13%) patients had mixed pneumonia. Cases including CAP, by a pyogenic bacteria and a complete paired serology for "atypicals", revealed that 82 (13%) patients had definite single pyogenic pneumonia and 28 patients (5%) had mixed pyogenic pneumonia. In patients with mixed CAP, Streptococcus pneumoniae was the most prevalent microorganism (44 out of 82; 54%). The most frequent combination was S. pneumoniae with Haemophilus influenzae (17 out of 82; 21%). Influenza virus A and S. pneumoniae (five out of 28; 18%) was the most frequent association in the mixed pyogenic pneumonia group. No clinical predictors for mixed pneumonias could be identified. Patients with mixed pyogenic pneumonia more frequently developed shock when compared with patients with single pyogenic pneumonia (18 versus 4%). In conclusion, mixed pneumonia occurs in >10% of cases with community-acquired pneumonia requiring hospitalisation.

Genomic Landscape of Intrahost Variation in Group A Streptococcus: Repeated and Abundant Mutational Inactivation of the fabT Gene Encoding a Regulator of Fatty Acid Synthesis

PubMed Central

Eraso, Jesus M.; Olsen, Randall J.; Beres, Stephen B.; Kachroo, Priyanka; Porter, Adeline R.; Nasser, Waleed; Bernard, Paul E.; DeLeo, Frank R.

2016-01-01

To obtain new information about Streptococcus pyogenes intrahost genetic variation during invasive infection, we sequenced the genomes of 2,954 serotype M1 strains recovered from a nonhuman primate experimental model of necrotizing fasciitis. A total of 644 strains (21.8%) acquired polymorphisms relative to the input parental strain. The fabT gene, encoding a transcriptional regulator of fatty acid biosynthesis genes, contained 54.5% of these changes. The great majority of polymorphisms were predicted to deleteriously alter FabT function. Transcriptome-sequencing (RNA-seq) analysis of a wild-type strain and an isogenic fabT deletion mutant strain found that between 3.7 and 28.5% of the S. pyogenes transcripts were differentially expressed, depending on the growth temperature (35°C or 40°C) and growth phase (mid-exponential or stationary phase). Genes implicated in fatty acid synthesis and lipid metabolism were significantly upregulated in the fabT deletion mutant strain. FabT also directly or indirectly regulated central carbon metabolism genes, including pyruvate hub enzymes and fermentation pathways and virulence genes. Deletion of fabT decreased virulence in a nonhuman primate model of necrotizing fasciitis. In addition, the fabT deletion strain had significantly decreased survival in human whole blood and during phagocytic interaction with polymorphonuclear leukocytes ex vivo. We conclude that FabT mutant progeny arise during infection, constitute a metabolically distinct subpopulation, and are less virulent in the experimental models used here. PMID:27600505

Case report: Co-infection of Rickettsia rickettsii and Streptococcus pyogenes: is fatal Rocky Mountain spotted fever underdiagnosed?

PubMed

Raczniak, Gregory A; Kato, Cecilia; Chung, Ida H; Austin, Amy; McQuiston, Jennifer H; Weis, Erica; Levy, Craig; Carvalho, Maria da Gloria S; Mitchell, Audrey; Bjork, Adam; Regan, Joanna J

2014-12-01

Rocky Mountain spotted fever, a tick-borne disease caused by Rickettsia rickettsii, is challenging to diagnose and rapidly fatal if not treated. We describe a decedent who was co-infected with group A β-hemolytic streptococcus and R. rickettsii. Fatal cases of Rocky Mountain spotted fever may be underreported because they present as difficult to diagnose co-infections. © The American Society of Tropical Medicine and Hygiene.

Influence of subinhibitory antibiotic concentration on Streptococcus pyogenes adherence and biofilm production.

PubMed

Šmitran, Aleksandra; Vuković, Dragana; Opavski, Nataša; Gajić, Ina; Marinković, Jelena; Božić, Ljiljana; Živanović, Irena; Kekić, Dušan; Popović, Sunčica; Ranin, Lazar

2018-06-01

In this study, the focus was on the effects of sub-MICs of the antibiotics on adherence, hydrophobicity, and biofilm formation by two groups of Streptococcus pyogenes strains, which were responsible for different clinical cases. The aim of this study was to explore the effects of sub-MICs of penicillin, ceftriaxone, erythromycin, and clindamycin on adherence, surface hydrophobicity, and biofilm biomass in two selected collections of group A streptococcus (GAS): strains isolated from carriers (CA) and strains isolated from patients with tonsillopharyngitis (TPh). Isolates were tested for hydrophobicity to xylene, adherence, and biofilm production in uncoated microtiter plates before and after treatment with 1/2 and 1/4 MICs of antibiotics. Penicillin reduced adherence and biofilm production in TPh strains, whereas ceftriaxone diminished adherence and biofilm formation in CA group. On the contrary, clindamycin enhanced adherence and biofilm production in both groups of strains. Erythromycin did not significantly alter adherence, but triggered biofilm production in both groups of isolates. Hydrophobicity of both groups of strains was significantly reduced after exposure to all antibiotics. Beta-lactams displayed anti-biofilm activity; penicillin diminished both adherence and biofilm production in TPh strains, whereas ceftriaxone reduced it in strains isolated from CA.

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

PubMed

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

2016-06-01

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

SpyB, a small heme-binding protein, affects the composition of the cell wall in Streptococcus pyogenes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edgar, Rebecca J.; Chen, Jing; Kant, Sashi

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 C 3-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 ofmore » 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. Furthermore, our data suggest the possibility that SpyB activity is regulated by heme.« less

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

PubMed

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.

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

PubMed

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

2016-02-01

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

SpyB, a small heme-binding protein, affects the composition of the cell wall in Streptococcus pyogenes

DOE PAGES

Edgar, Rebecca J.; Chen, Jing; Kant, Sashi; ...

2016-10-13

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 C 3-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 ofmore » 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. Furthermore, our data suggest the possibility that SpyB activity is regulated by heme.« less

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

PubMed Central

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

2011-01-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Swati; Kumar, Ashok, E-mail: rajesh-csir@yahoo.com, E-mail: ashokigib@rediffmail.com; Academy of Scientific and Innovative Research

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

Streptococcal toxic shock syndrome from necrotizing soft-tissue infection of the breast caused by a mucoid type strain.

PubMed

Kohayagawa, Yoshitaka; Ishitobi, Natsuko; Yamamori, Yuji; Wakuri, Miho; Sano, Chiaki; Tominaga, Kiyoshi; Ikebe, Tadayoshi

2015-02-01

Streptococcal toxic shock syndrome is a severe infectious disease. We report a Japanese case of Streptococcal toxic shock syndrome caused by a highly mucoid strain of Streptococcus pyogenes. A 31-year old female with shock vital sign presented at a tertiary medical center. Her left breast was necrotizing and S. pyogenes was detected by Immunochromatographic rapid diagnostic kits. Intensive care, including administration of antibiotics and skin debridement, was performed. After 53 days in our hospital, she was discharged. The blood cultures and skin swab cultures all grew S. pyogenes which displayed a highly mucoid morphology on culture media. In her course of the disease, the Streptococcus strain had infected two other family members. All of the strains possessed the T1 and M1 antigens, as well as the emm1.0 gene. As for fever genes, the strains were all positive for speA, speB, and speF, but negative for speC. All of the strains exhibited and the same pattern in PFGE with the SfiI restriction enzyme. The strain might have spread in the local area by the data from the Japanese Infectious Disease Surveillance Center. Immunochromatographic rapid diagnostic kits are very useful for detecting S. pyogenes. However, they can not be used to diagnose severe streptococcul disease by highly mucoid strain alone. Careful observation of patients and colony morphology are useful methods for diagnosing severe streptococcal disease by highly mucoid strain. Copyright © 2014 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

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

PubMed

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

2014-04-01

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

[Biological activity tests of chemical constituents from two Brazilian Labiatae plants].

PubMed

Isobe, Takahiko; Doe, Matsumi; Morimoto, Yoshiki; Nagata, Kumiko; Masuoka, Noriyoshi; Ohsaki, Ayumi

2007-02-01

We studied the bioactivities of constituents from two tropical medicinal plants, Cunila spicata and Hyptis fasciculata. These plants found in Brazil belong to the Labiatae family. Four known compounds obtained from these herbs were identified as 3alpha, 24-dihydoxylurs-12-en-28-oic acid, betulinic acid, aurantiamide acetate, and aurantiamide benzoate by spectroscopic means. 3alpha, 24-Dihydoxylurs-12-en-28-oic acid has potent inhibitory activity against Streptococcus salivarius, Streptococcus pneumoniae, Streptococcus pyogenes, and Porphyromomas gingivalis. Aurantiamide benzoate exhibited moderate inhibitory activity against xanthine oxidase. It was clarified that herbs Cunila spicata and Hyptis fasciculata are effective against bronchitis and gout.

In vitro activity of flomoxef in comparison to other cephalosporins.

PubMed

Simon, C; Simon, M; Plieth, C

1988-01-01

Flomoxef and cefazolin had nearly the same activity against staphylococci, which was stronger than that of other cephalosporins. Against Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus pneumoniae, cefotaxime and cefazolin were more active than flomoxef, but the other cephamycins were less active than flomoxef. In comparison to the other cephalosporins, latamoxef and flomoxef had higher activity against Branhamella catarrhalis, whereas cefotaxime, latamoxef and cefotetan were more active against Haemophilus influenzae. Flomoxef was the only drug exhibiting activity against Clostridium difficile. The activity of flomoxef and latamoxef against Bacteroides fragilis was stronger than that of the other cephalosporins, but Bacteroides bivius was resistant to each of these antibiotics.

Respiratory Diseases among U.S. Military Personnel: Countering Emerging Threats

PubMed Central

Callahan, Johnny D.; Hawksworth, Anthony W.; Fisher, Carol A.; Gaydos, Joel C.

1999-01-01

Emerging respiratory disease agents, increased antibiotic resistance, and the loss of effective vaccines threaten to increase the incidence of respiratory disease in military personnel. We examine six respiratory pathogens (adenoviruses, influenza viruses, Streptococcus pneumoniae, Streptococcus pyogenes, Mycoplasma pneumoniae, and Bordetella pertussis) and review the impact of the diseases they cause, past efforts to control these diseases in U.S. military personnel, as well as current treatment and surveillance strategies, limitations in diagnostic testing, and vaccine needs. PMID:10341174

Novel strategies for controlling Streptococcus pyogenes infection and associated diseases: from potential peptide vaccines to antibody immunotherapy.

PubMed

Pandey, Manisha; Sekuloski, Silvana; Batzloff, Michael R

2009-07-01

Infections caused by group A streptococcus (GAS) represent a public health problem in both developing and developed countries. The current available methods of prevention are either inadequate or ineffective, which is highlighted by the resurgence in invasive GAS infections over the past two decades. The management of GAS and associated diseases requires new and improved approaches. This review discusses various potential approaches in controlling GAS infections, ranging from prophylactic vaccines to antibody immunotherapy.

Protective immunity induced by an intranasal multivalent vaccine comprising 10 Lactococcus lactis strains expressing highly prevalent M-protein antigens derived from Group A Streptococcus.

PubMed

Wozniak, Aniela; Scioscia, Natalia; García, Patricia C; Dale, James B; Paillavil, Braulio A; Legarraga, Paulette; Salazar-Echegarai, Francisco J; Bueno, Susan M; Kalergis, Alexis M

2018-04-28

Streptococcus pyogenes (group A Streptococcus) causes diseases ranging from mild pharyngitis to severe invasive infections. The N-terminal fragment of Streptococcal M protein elicits protective antibodies and is an attractive vaccine target. However, this N- terminal fragment is hypervariable and there are more than 200 different M types. We are developing an intranasal live bacterial vaccine comprised of 10 strains of Lactococcus lactis, each expressing one N-terminal fagment of M protein. Live bacterial-vectored vaccines have lower associated costs because of its less complex manufacturing processes compared to protein subunit vaccines. Moreover, intranasal administration does not require syringe or specilized personnel. The evaluation of individual vaccine types (M1, M2, M3, M4, M6, M9, M12, M22, M28 and M77) showed that most of them protected mice against challenge with virulent S. pyogenes. All of the 10 strains combined in a 10-valent vaccine (Mx10) induced serum and bronchoalveolar lavages IgG titers that ranged from 3 to 10-fold those of unimmunized mice. Survival of Mx10-immunized mice after intranasal challenge with M28 streptococci is significantly higher than unimmunized mice. In contrast, when mice were challenged with M75 streptococci, survival of Mx10-immunized mice was not significantly different from unimmunized mice. Mx-10 immunized mice were significantly less colonized with S. pyogenes in oropharyngeal washes and developed less severe disease symptoms after challenge compared to unimmunized mice. Our L. lactis-based vaccine may provide an alternative solution to the development of broadly protective group A streptococcal vaccines. © 2018 The Societies and John Wiley & Sons Australia, Ltd.

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

PubMed

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.

Rapid and Accurate Diagnosis of Acute Pyogenic Meningitis Due to Streptococcus Pneumoniae, Haemophilus influenzae Type b and Neisseria meningitidis Using A Multiplex PCR Assay.

PubMed

Seth, Rajeev; Murthy, Peela Sree Ramchandra; Sistla, Sujatha; Subramanian, Mahadevan; Tamilarasu, Kadhiravan

2017-09-01

Acute bacterial meningitis is one of the major causes of morbidity and mortality in children and geriatric population, especially in developing countries. Methods of identification are standard culture and other phenotypic tests in many resource poor settings. To use molecular methods for the improvement of aetiological diagnosis of acute pyogenic meningitis in patients. CSF samples of 125 patients were included for the study. Gram staining and culture were performed according to standard procedures. Antigen was detected using commercial latex agglutination test kit. Multiplex PCR was performed using previously published primers and protocols. Fischer's exact test was used for finding association between presence of the disease and clinical/biochemical parameters, considering two tailed p<0.05 as statistically significant. Sensitivity, specificity, positive and negative predictive values were calculated using Graphpad QuicCalc software. A total of 39 cases (31.2%) were confirmed to be of acute pyogenic meningitis based on biochemical methods. Only 10/39 was positive for the three organisms tested. Multiplex PCR was able to detect one additional isolate each of Streptococcus pneumoniae and Haemophilus influenzae type b. When compared with multiplex PCR as the gold standard, culture and latex agglutination tests had same sensitivity (80%), specificity (100%), PPV (100%) and NPV (97.8%), whereas Gram stain had poor sensitivity (40%) and good specificity (95.6%). Detection rates were higher in multiplex PCR for the two organisms Streptococcus pneumoniae and Haemophilus influenzae type b. Multiplex PCR was more sensitive than culture or antigen detection, and employing this assay can significantly increase the speed and accuracy of identification of the pathogen.

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

PubMed

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

2016-10-01

Nucleic acid amplification tests (NAATs) have frequently been the standard diagnostic approach when specific infectious agents are sought in a clinic specimen. They can be applied for specific agents such as S. pyogenes, or commercial multiplex NAATs for detection of a variety of pathogens in gastrointestinal, bloodstream, and respiratory infections may be used. NAATs are both rapid and sensitive. For many years, S. pyogenes testing algorithms used a rapid and specific group A streptococcal antigen test to screen throat specimens, followed, in some clinical settings, by a throat culture for S. pyogenes to increase the sensitivity of its detection. Now S. pyogenes NAATs are being used with increasing frequency. Given their accuracy, rapidity, and ease of use, should they replace antigen detection and culture for the detection of bacterial pharyngitis? Bobbi Pritt and Robin Patel of the Mayo Clinic, where S. pyogenes NAATs have been used for well over a decade with great success, will explain the advantages of this approach, while Richard (Tom) Thomson and Tom Kirn of the NorthShore University HealthSystem will discuss their concerns about this approach to diagnosing bacterial pharyngitis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

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

PubMed

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 CovR plays a crucial role. As an OmpR/PhoB family member, CovR is activated by phosphorylation on a conserved aspartate residue, leading to protein dimerization and subsequent binding to operator sites. Our transcriptome analysis using the monomeric phosphorylation mimic mutant CovR-D53E broadens this general notion by revealing dimerization-independent repression of a subset of CovR-regulated genes. Combined with promoter analyses, these data suggest distinct mechanisms of CovR transcriptional control, which allow for differential expression of virulence genes in response to environmental cues. Copyright © 2017 American Society for Microbiology.

Structure of the streptococcal endopeptidase IdeS, a cysteine proteinase with strict specificity for IgG.

PubMed

Wenig, Katja; Chatwell, Lorenz; von Pawel-Rammingen, Ulrich; Björck, Lars; Huber, Robert; Sondermann, Peter

2004-12-14

Pathogenic bacteria have developed complex and diverse virulence mechanisms that weaken or disable the host immune defense system. IdeS (IgG-degrading enzyme of Streptococcus pyogenes) is a secreted cysteine endopeptidase from the human pathogen S. pyogenes with an extraordinarily high degree of substrate specificity, catalyzing a single proteolytic cleavage at the lower hinge of human IgG. This proteolytic degradation promotes inhibition of opsonophagocytosis and interferes with the killing of group A Streptococcus. We have determined the crystal structure of the catalytically inactive mutant IdeS-C94S by x-ray crystallography at 1.9-A resolution. Despite negligible sequence homology to known proteinases, the core of the structure resembles the canonical papain fold although with major insertions and a distinct substrate-binding site. Therefore IdeS belongs to a unique family within the CA clan of cysteine proteinases. Based on analogy with inhibitor complexes of papain-like proteinases, we propose a model for substrate binding by IdeS.

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

PubMed

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

2013-05-01

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 I41, 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.

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

PubMed Central

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

2013-01-01

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 I41, 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. PMID:23695577

The incidence of scarlet fever.

PubMed Central

Perks, E. M.; Mayon-White, R. T.

1983-01-01

This study attempted to find the incidence of scarlet fever in the Oxford region, including the proportion of patients from whom Streptococcus pyogenes could be isolated. General practitioners collected throat swabs from patients with suspected scarlet fever. The swabs were examined for viral and bacterial pathogens. Children admitted to hospital were used as controls. Twenty-five of 105 patients with suspected scarlet fever grew Str. pyogenes; M type 4 was the commonest type. The clinical diagnosis of scarlet fever was not always confirmed by throat culture. The annual incidence of scarlet fever was estimated to be 0.3 cases per 1000 per year. PMID:6358344

Streptococcus pyogenes outbreak in a long-term care facility.

PubMed

Harkness, G A; Bentley, D W; Mottley, M; Lee, J

1992-06-01

Although outbreaks involving Streptococcus pyogenes have been uncommon among the elderly population, recent reports suggest that this organism is an important nosocomial pathogen among institutionalized older patients and carries significant morbidity and mortality. An outbreak of S. pyogenes, type M12, T12, occurred in a large long-term care institution serving the ill and chronically disabled. The outbreak involved 14 residents of the intermediate care facility and lasted for 4 months. A prospective epidemiologic investigation was initiated at the onset of the outbreak. Pertinent clinical and demographic information regarding both residents and personnel was obtained by interview, review of medical and surveillance records, and examination of patients for lesions. Cultures were obtained within 24 hours of symptom onset from those with characteristic clinical symptoms. Unpaired convalescent sera were tested for group A streptococcal extracellular antigens by a rapid hemagglutination slide test. Control measures included active surveillance of residents and staff for suspicious clinical syndromes, transfer of high-risk patients, elimination of a common seating area, and improved handwashing and hygiene measures. The attack rate was 7.5%, with 64.3% of these patients residing on one unit. S. pyogenes was isolated from eight residents, 5 residents had a characteristic syndrome and an elevated streptozyme hemagglutination titer of 400, and 1 resident died within hours of having cellulitis of the groin. Clinical syndromes included cellulitis, pharyngitis, bronchitis, pneumonia, and septicemia. Seven residents required acute care; two residents died within 3 weeks of the onset, yielding a case fatality rate of 14.3%. The major means of transmission appeared to be direct contact between residents, although transmission from an infected staff member may have accounted for some cases. The hypothesis of long-term colonization was supported by the extended times between infections. The severity of illness and the apparent transmission through direct contact between residents warrants (1) early detection of infected lesions, (2) recognition of invasive illness, (3) prompt effective treatment, and (4) surveillance for S. pyogenes infections among residents and personnel.

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

PubMed

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-pH environment. Dissection of these collaborative pathways highlights the complexity of bacterial infections and the contribution of atypical nutrients, such as citrulline, to pathogenesis. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

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.

PubMed

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 the secretome in acidic and neutral conditions. The dynamic label-free LC-MS/MS profiling and secretome prediction were used in this study for mining acid-influenced secreted proteins. We identified 33 acid-influenced secreted proteins in this study. Among these proteins, a novel acid-induced virulence factor, HtpA, was demonstrated to improve anti-phagocytosis ability for causing necrotizing fasciitis. In addition, our study demonstrates the first evidence that acidic stimuli and growth-phase cues are crucial for classical protein secretion in S. pyogenes. Copyright © 2014. Published by Elsevier B.V.

5-Fluorouracil sensitivity varies among oral micro-organisms.

PubMed

Vanlancker, Eline; Vanhoecke, Barbara; Smet, Rozel; Props, Ruben; Van de Wiele, Tom

2016-08-01

5-Fluorouracil (5-FU), a commonly used chemotherapeutic agent, often causes oral mucositis, an inflammation and ulceration of the oral mucosa. Micro-organisms in the oral cavity are thought to play an important role in the aggravation and severity of mucositis, but the mechanisms behind this remain unclear. Although 5-FU has been shown to elicit antibacterial effects at high concentrations (>100 µM), its antibacterial effect at physiologically relevant concentrations in the oral cavity is unknown. This study reports the effect of different concentrations of 5-FU (range 0.1-50 µM) on the growth and viability of bacterial monocultures that are present in the oral cavity and the possible role in the activity of dihydropyrimidine dehydrogenase (DPD), an enzyme involved in 5-FU resistance. Our data showed a differential sensitivity among the tested oral species towards physiological concentrations of 5-FU. Klebsiellaoxytoca, Streptococcus salivarius, Streptococcus mitis, Streptococcus oralis, Pseudomonas aeruginosa and Lactobacillus salivarius appeared to be highly resistant to all tested concentrations. In contrast, Lactobacillusoris, Lactobacillus plantarum, Streptococcus pyogenes, Fusobacterium nucleatum and Neisseria mucosa showed a significant reduction in growth and viability starting from very low concentrations (0.2-3.1 µM). We can also provide evidence that DPD is not involved in the 5-FU resistance of the selected species. The observed variability in response to physiological 5-FU concentrations may explain why certain microbiota lead to a community dysbiosis and/or an overgrowth of certain resistant micro-organisms in the oral cavity following cancer treatment.

Group A streptococcal infections of the skin: molecular advances but limited therapeutic progress.

PubMed

Currie, Bart J

2006-04-01

With the sequencing of several Streptococcus pyogenes (group A Streptococcus) genomes have come major advances in understanding the pathogenesis of group A Streptococcus-associated diseases. This review focuses on group A Streptococcus skin infections and summarizes data published in the English language medical literature in 2004 and 2005. Group A Streptococcus shows enormous and evolving molecular diversity driven by horizontal transmission between group A Streptococcus strains and between group A Streptococcus and other streptococci. Acquisition of prophages accounts for much of the diversity, conferring both virulence through phage-associated virulence factors and increased bacterial survival against host defences. Studies of group A Streptococcus isolates outside the US also question the generalizability of classic group A Streptococcus M serotype associations with specific disease entities such as acute rheumatic fever and necrotizing fasciitis. The distinction between throat and skin group A Streptococcus has become blurred. Although there have been few advances in treatment of group A Streptococcus skin infections, developments towards group A Streptococcus vaccines are promising. The diversity of group A Streptococcus remains a challenge for vaccine development. As acute rheumatic fever and streptococcal pyoderma occur predominantly in disadvantaged populations, international funding support will be necessary for any group A Streptococcus vaccine to have a sustained impact on the global burden of disease.

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

PubMed Central

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

2016-01-01

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

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

PubMed

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

2016-01-01

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

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

PubMed

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

2016-06-28

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

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

PubMed

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

2016-05-01

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

Novel Genes Required for the Fitness of Streptococcus pyogenes in Human Saliva

PubMed Central

Zhu, Luchang; Charbonneau, Amelia R. L.; Waller, Andrew S.; Olsen, Randall J.; Beres, Stephen B.

2017-01-01

ABSTRACT Streptococcus pyogenes (group A streptococcus [GAS]) causes 600 million cases of pharyngitis each year. Despite this considerable disease burden, the molecular mechanisms used by GAS to infect, cause clinical pharyngitis, and persist in the human oropharynx are poorly understood. Saliva is ubiquitous in the human oropharynx and is the first material GAS encounters in the upper respiratory tract. Thus, a fuller understanding of how GAS survives and proliferates in saliva may provide valuable insights into the molecular mechanisms at work in the human oropharynx. We generated a highly saturated transposon insertion mutant library in serotype M1 strain MGAS2221, a strain genetically representative of a pandemic clone that arose in the 1980s and spread globally. The transposon mutant library was exposed to human saliva to screen for GAS genes required for wild-type fitness in this clinically relevant fluid. Using transposon-directed insertion site sequencing (TraDIS), we identified 92 genes required for GAS fitness in saliva. The more prevalent categories represented were genes involved in carbohydrate transport/metabolism, amino acid transport/metabolism, and inorganic ion transport/metabolism. Using six isogenic mutant strains, we confirmed that each of the mutants was significantly impaired for growth or persistence in human saliva ex vivo. Mutants with an inactivated Spy0644 (sptA) or Spy0646 (sptC) gene had especially severe persistence defects. This study is the first to use of TraDIS to study bacterial fitness in human saliva. The new information we obtained will be valuable for future translational maneuvers designed to prevent or treat human GAS infections. IMPORTANCE The human bacterial pathogen Streptococcus pyogenes (group A streptococcus [GAS]) causes more than 600 million cases of pharyngitis annually worldwide, 15 million of which occur in the United States. The human oropharynx is the primary anatomic site for GAS colonization and infection, and saliva is the first material encountered. Using a genome-wide transposon mutant screen, we identified 92 GAS genes required for wild-type fitness in human saliva. Many of the identified genes are involved in carbohydrate transport/metabolism, amino acid transport/metabolism, and inorganic ion transport/metabolism. The new information is potentially valuable for developing novel GAS therapeutics and vaccine research. PMID:29104937

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

PubMed

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

2013-12-01

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

Essential oils from Origanum vulgare and Salvia officinalis exhibit antibacterial and anti-biofilm activities against Streptococcus pyogenes.

PubMed

Wijesundara, Niluni M; Rupasinghe, H P Vasantha

2018-04-01

In the present study, essential oils (EOs) extracted from oregano, sage, cloves, and ginger were evaluated for the phytochemical profile, antibacterial, and anti-biofilm activities against Streptococcus pyogenes. The broth microdilution method was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of EOs. The minimum biofilm inhibitory concentrations (MBICs) were determined using MTT assay and fixed biofilms were observed through scan electron microscopy. The oregano and sage EOs showed the lowest MIC as well as MBC of 0.25-0.5 mg/mL. Time kill assay results showed that oregano and sage EOs exhibited bactericidal effects within 5 min and 4 h, respectively. Both oregano and sage extracts acts as a potent anti-biofilm agent with dual actions, preventing and eradicating the biofilm. The microscopic visualization of biofilms treated with EOs have shown morphological and density changes compared to the untreated control. Oregano EO was constituted predominantly carvacrol (91.6%) and in sage EO, higher levels of α-thujone (28.5%) and camphor (16.6%) were revealed. EOs of oregano and sage inhibit the growth and biofilm formation of S. pyogenes. Effective concentrations of oregano and sage EOs and their phytochemicals can be used in developing potential plant-derived antimicrobial agents in the management of streptococcal pharyngitis. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

PubMed Central

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

2012-01-01

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

The extracellular protein factor Epf from Streptococcus pyogenes is a cell surface adhesin that binds to cells through an N-terminal domain containing a carbohydrate-binding module.

PubMed

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

2012-11-02

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

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

PubMed

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.

Interference of a speB 5' untranslated region partial deletion with mRNA degradation in Streptococcus pyogenes.

PubMed

Chen, Z; Mashburn-Warren, L; Merritt, J; Federle, M J; Kreth, J

2017-10-01

The 5' untranslated region (5' UTR) of an mRNA molecule embeds important determinants that modify its stability and translation efficiency. In Streptococcus pyogenes, a strict human pathogen, a gene encoding a secreted protease (speB) has a large 5' UTR with unknown functions. Here we describe that a partial deletion of the speB 5' UTR caused a general accumulation of mRNA in the stationary phase, and that the mRNA accumulation was due to retarded mRNA degradation. The phenotype was observed in several M serotypes harboring the partial deletion of the speB 5' UTR. The phenotype was triggered by the production of the truncated speB 5' UTR, but not by the disruption of the intact speB 5' UTR. RNase Y, a major endoribonuclease, was previously shown to play a central role in bulk mRNA turnover in stationary phase. However, in contrast to our expectations, we observed a weaker interaction between the truncated speB 5' UTR and RNase Y compared with the wild-type, which suggests that other unidentified RNA degrading components are required for the pleiotropic effects observed from the speB UTR truncation. Our study demonstrates how S. pyogenes uses distinct mRNA degradation schemes in exponential and stationary growth phases. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Structure of a group A streptococcal phage-encoded virulence factor reveals a catalytically active triple-stranded beta-helix.

PubMed

Smith, Nicola L; Taylor, Edward J; Lindsay, Anna-Marie; Charnock, Simon J; Turkenburg, Johan P; Dodson, Eleanor J; Davies, Gideon J; Black, Gary W

2005-12-06

Streptococcus pyogenes (group A Streptococcus) causes severe invasive infections including scarlet fever, pharyngitis (streptococcal sore throat), skin infections, necrotizing fasciitis (flesh-eating disease), septicemia, erysipelas, cellulitis, acute rheumatic fever, and toxic shock. The conversion from nonpathogenic to toxigenic strains of S. pyogenes is frequently mediated by bacteriophage infection. One of the key bacteriophage-encoded virulence factors is a putative "hyaluronidase," HylP1, a phage tail-fiber protein responsible for the digestion of the S. pyogenes hyaluronan capsule during phage infection. Here we demonstrate that HylP1 is a hyaluronate lyase. The 3D structure, at 1.8-angstroms resolution, reveals an unusual triple-stranded beta-helical structure and provides insight into the structural basis for phage tail assembly and the role of phage tail proteins in virulence. Unlike the triple-stranded beta-helix assemblies of the bacteriophage T4 injection machinery and the tailspike endosialidase of the Escherichia coli K1 bacteriophage K1F, HylP1 possesses three copies of the active center on the triple-helical fiber itself without the need for an accessory catalytic domain. The triple-stranded beta-helix is not simply a structural scaffold, as previously envisaged; it is harnessed to provide a 200-angstroms-long substrate-binding groove for the optimal reduction in hyaluronan viscosity to aid phage penetration of the capsule.

Functional analysis of Streptococcus pyogenes nuclease A (SpnA), a novel group A streptococcal virulence factor.

PubMed

Chang, Ann; Khemlani, Adrina; Kang, HaeJoo; Proft, Thomas

2011-03-01

Streptococcus pyogenes nuclease A (SpnA) is a recently discovered DNase that plays a role in virulence as shown in a mouse infection model. SpnA is the only cell wall-anchored DNase found in S. pyogenes thus far and shows a unique protein architecture. The C-terminal nuclease domain contains highly conserved catalytic site and Mg(2+) binding site residues. However, expression of the SpnA nuclease domain alone resulted in a soluble, but enzymatically inactive protein. We found that at least two out of three oligonucleotide/oligosaccharide-binding fold motifs found in the N-terminal domain are required for SpnA activity, probably contributing to substrate binding. Using a combination of a spnA deletion mutant and a Lactococcus lactis'gain-of-function' mutant, we have shown that SpnA promotes survival in whole human blood and in neutrophil killing assays and this is, at least in part, achieved by the destruction of neutrophil extracellular traps (NETs). We observed higher frequencies for anti-SpnA antibodies in streptococcal disease patient sera (79%, n = 19) compared with sera from healthy donors (33%, n = 9) suggesting that SpnA is expressed during infection. Detection of anti-SpnA antibodies in patient serum might be useful for the diagnostic of post-streptococcal diseases, such as acute rheumatic fever or glomerulonephritis. © 2011 Blackwell Publishing Ltd.

Flomoxef showed excellent in vitro activity against clinically important gram-positive and gram-negative pathogens causing community- and hospital-associated infections.

PubMed

Yang, Qiwen; Zhang, Hui; Cheng, Jingwei; Xu, Zhipeng; Hou, Xin; Xu, Yingchun

2015-04-01

The objective of this study was to better understand the in vitro activity of flomoxef against clinical pathogens. A total of 545 clinical isolates, including Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus, Streptococcus pneumoniae, and Streptococcus pyogenes, were isolated consecutively from clinical specimens from Peking Union Medical College Hospital in 2013. MICs were determined using broth microdilution method. esbl and ampC genes were detected by polymerase chain reaction and sequencing. Flomoxef showed excellent activity against E. coli, K. pneumoniae, and P. mirabilis isolates, with susceptibility rate of 88.8%, 88.3%, and 97.7%, separately. Moreover, flomoxef exhibited great activity against extended-spectrum beta-lactamase (ESBL) producers, with MIC50/MIC90 of 0.125/(0.5-1) μg/mL. Flomoxef showed MIC50/MIC90 of 0.5/0.5 μg/mL against MSSA, 0.125/0.25 μg/mL against S. pyogenes, and 2/16 μg/mL against S. pneumoniae. In conclusion, flomoxef is one of the cephamycins showing excellent activity against ESBL-producing or ESBL-nonproducing E. coli, K. pneumoniae, and P. mirabilis and was also potent against MSSA, S. pyogenes, and S. pneumoniae. Copyright © 2015 Elsevier Inc. All rights reserved.

[Epidemiological study on Streptococcus pyogenes strains isolated from the patients with streptococcal toxic shock syndrome (STSS) in Japan in 1992-2001].

PubMed

Okuno, Rumi; Endoh, Miyoko; Shimojima, Yukako; Yanagawa, Yoshitoki; Morozumi, Satoshi; Igarashi, Hideo; Ooe, Kenji

2004-01-01

To investigate clinical and microbiological features of streptococcal toxic shock syndrome (STSS), clinical, epidemiological, and bacteriological data obtained from 250 patients between 1992 and 2001 were analyzed. Among these 250 cases, 16 cases were excluded from the study because the causative microorganism were not Streptococcus pyogenes. 234 strains of S. pyogenes obtained from the aforementioned 234 cases were tested for T-type by a serological method, and for streptococcal pyrogenic exotoxin (SPE) by in vitro productivity of the toxin as well as molecular genetic methods. The number of patients was 141 (56.4%) for males, and 107 (42.8%) for females. The highest frequency of STSS was observed in those patients in their sixties in both sexes. The overall mortality rate was 43.2%. The mortality rate for male was 36.9%, and 52.3% for female. Bacteriological studies revealed that most common T types were T1 and T3. These strains consisted 54.3% of the strains collected. Among strains of T1 type, 98.8% possessed genes of spe A, and 46.1% were shown to produce SPE A in vitro. Among strains of T3 type, 82.9% possessed spe A gene, and all of these strains were shown to produce the toxin in vitro. It is concluded that certain strains of S. pyogenes, such as those with T1, or T3 type, and those with spe A gene or in vitro production of SPE A, are the most frequent cause of STSS. Although infections caused by such bacteria are quite common, STSS rarely occurs in most such patients. Additional factors, such as host factors, may play a crucial role in the pathogenesis of STSS.

Virulence gene regulation by CvfA, a putative RNase: the CvfA-enolase complex in Streptococcus pyogenes links nutritional stress, growth-phase control, and virulence gene expression.

PubMed

Kang, Song Ok; Caparon, Michael G; Cho, Kyu Hong

2010-06-01

Streptococcus pyogenes, a multiple-auxotrophic human pathogen, regulates virulence gene expression according to nutritional availability during various stages in the infection process or in different infection sites. We discovered that CvfA influenced the expression of virulence genes according to growth phase and nutritional status. The influence of CvfA in C medium, rich in peptides and poor in carbohydrates, was most pronounced at the stationary phase. Under these conditions, up to 30% of the transcriptome exhibited altered expression; the levels of expression of multiple virulence genes were altered, including the genes encoding streptokinase, CAMP factor, streptolysin O, M protein (more abundant in the CvfA(-) mutant), SpeB, mitogenic factor, and streptolysin S (less abundant). The increase of carbohydrates or peptides in media restored the levels of expression of the virulence genes in the CvfA(-) mutant to wild-type levels (emm, ska, and cfa by carbohydrates; speB by peptides). Even though the regulation of gene expression dependent on nutritional stress is commonly linked to the stringent response, the levels of ppGpp were not altered by deletion of cvfA. Instead, CvfA interacted with enolase, implying that CvfA, a putative RNase, controls the transcript decay rates of virulence factors or their regulators according to nutritional status. The virulence of CvfA(-) mutants was highly attenuated in murine models, indicating that CvfA-mediated gene regulation is necessary for the pathogenesis of S. pyogenes. Taken together, the CvfA-enolase complex in S. pyogenes is involved in the regulation of virulence gene expression by controlling RNA degradation according to nutritional stress.

Effects of meteorologic factors and schooling on the seasonality of group A streptococcal pharyngitis

NASA Astrophysics Data System (ADS)

Hervás, Daniel; Hervás-Masip, Juan; Ferrés, Laia; Ramírez, Antonio; Pérez, José L.; Hervás, Juan A.

2016-05-01

The objective of this study was to determine the seasonal pattern of group A streptococcal pharyngitis in children attended at a hospital emergency department in the Mediterranean island of Mallorca (Spain), and its association with meteorologic factors and schooling. We conducted a retrospective review of the medical records of children aged 1-15 years with a diagnosis of Streptococcus pyogenes pharyngitis between January 2006 and December 2011. The number of S. pyogenes pharyngitis was correlated to temperature, humidity, rainfall, atmospheric pressure, wind speed, solar radiation, and schooling, using regression and time series techniques. A total of 906 patients (median, 4 years old) with S. pyogenes pharyngitis, confirmed by throat culture, were attended during the study period. A seasonal pattern was observed with a peak activity in June and a minimum in September. Mean temperature, solar radiation, and school holidays were the best predicting variables ( R 2 = 0.68; p < 0.001 ). S. pyogenes activity increased with the decrease of mean temperature ( z = -2.4; p < 0.05), the increase of solar radiation ( z = 4.2; p < 0.001), and/or the decrease in school holidays ( z = -2.4; p < 0.05). In conclusion, S. pyogenes pharyngitis had a clear seasonality predominating in springtime, and an association with mean temperature, solar radiation, and schooling was observed. The resulting model predicted 68 % of S. pyogenes pharyngitis.

Manuka honey inhibits adhesion and invasion of medically important wound bacteria in vitro.

PubMed

Maddocks, Sarah Elizabeth; Jenkins, Rowena Eleri; Rowlands, Richard Samuel; Purdy, Kevin John; Cooper, Rose Agnes

2013-12-01

To characterize the effect of manuka honey on medically important wound bacteria in vitro, focusing on its antiadhesive properties. Crystal violet biofilm assays, fluorescent microscopy, protein adhesion assay and gentamicin protection assay were used to determine the impact of manuka honey on biofilm formation, human protein binding and adherence to/invasion into human keratinocytes. Manuka honey effectively disrupted and caused extensive cell death in biofilms of Staphylococcus aureus, Pseudomonas aeruginosa and Streptococcus pyogenes. Sublethal doses of manuka honey inhibited bacterial adhesion to the fibronectin, fibrinogen and collagen. Manuka honey impaired adhesion of laboratory and clinical isolates of S. aureus, P. aeruginosa and S. pyogenes to human keratinocytes in vitro, and inhibited invasion by S. pyogenes and homogeneous vancomycin intermediate S. aureus. Manuka honey can directly affect bacterial cells embedded in a biofilm and exhibits antiadhesive properties against three common wound pathogens.

Streptococcal Diversity of Human Milk and Comparison of Different Methods for the Taxonomic Identification of Streptococci.

PubMed

Martín, Virginia; Mediano, Pilar; Del Campo, Rosa; Rodríguez, Juan M; Marín, María

2016-11-01

The genus Streptococcus is 1 of the dominant bacterial groups in human milk, but the taxonomic identification of some species remains difficult. The objective of this study was to investigate the discriminatory ability of different methods to identify streptococcal species in order to perform an assessment of the streptococcal diversity of human milk microbiota as accurately as possible. The identification of 105 streptococcal strains from human milk was performed by 16S rRNA, tuf, and sodA gene sequencing, phylogenetic analysis, and Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) mass spectrometry. Streptococcus salivarius, Streptococcus mitis, and Streptococcus parasanguinis were the streptococcal dominant species in the human milk microbiota. Sequencing of housekeeping genes allowed the classification of 96.2% (16S rRNA), 84.8% ( sodA), and 88.6% ( tuf) of the isolates. Phylogenetic analysis showed 3 main streptococcal clusters corresponding with the mitis (73 isolates), salivarius (29), mutans (1)-pyogenic (2) groups, but many of the mitis group isolates (36) could not be assigned to any species. The application of the MALDI-TOF Bruker Biotyper system resulted in the identification of 56 isolates (53.33%) at the species level, but it could not discriminate between S pneumoniae and S mitis isolates, in contrast to the Vitek-MS system. There was a good agreement among the different methods assessed in this study to identify those isolates of the salivarius, mutans, and pyogenic groups, whereas unambiguous discrimination could not be achieved concerning some species of the mitis group ( S mitis, S pneumoniae, S pseudopneumoniae, S oralis).

Systemic cytokine response in moribund mice of streptococcal toxic shock syndrome model.

PubMed

Saito, Mitsumasa; Kajiwara, Hideko; Iida, Ken-ichiro; Hoshina, Takayuki; Kusuhara, Koichi; Hara, Toshiro; Yoshida, Shin-ichi

2011-02-01

Streptococcus pyogenes causes severe invasive disease in humans, including streptococcal toxic shock syndrome (STSS). We previously reported a mouse model that is similar to human STSS. When mice were infected intramuscularly with 10(7) CFU of S. pyogenes, all of them survived acute phase of infection. After 20 or more days of infection, a number of them died suddenly accompanied by S. pyogenes bacteremia. We call this phenomenon "delayed death". We analyzed the serum cytokine levels of mice with delayed death, and compared them with those of mice who died in the acute phase of intravenous S. pyogenes infection. The serum levels of TNF-α and IFN-γ in mice of delayed death were more than 100 times higher than those in acute death mice. IL-10 and IL-12, which were not detected in acute death, were also significantly higher in mice of delayed death. IL-6 and MCP-1 (CCL-2) were elevated in both groups of mice. It was noteworthy that not only pro-inflammatory cytokines but also anti-inflammatory cytokines were elevated in delayed death. We also found that intravenous TNF-α injection accelerated delayed death, suggesting that an increase of serum TNF-α induced S. pyogenes bacteremia in our mouse model. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effects of natural honey on polymicrobial culture of various human pathogens

PubMed Central

Al-Waili, Faiza S.; Akmal, Mohammed; Ali, Amjed; Salom, Khelod Y.; Al Ghamdi, Ahmad A.

2012-01-01

Introduction Honey has a wide range of antimicrobial activity. All previous studies have considered honey's effect on a single microbe. The present study investigated activity of honey towards a high dose of single or polymicrobial culture. Material and methods 10 µl specimens of Staphylococcus aureus (S. aureus), Streptococcus pyogenes (S. pyogenes), Escherichia coli (E. coli) and Candida albicans (C. albicans) were cultured in 10 ml of 10-100% (wt/v) honey diluted in broth. Six types of polymicrobial microbial cultures were prepared by culturing the isolates with each other onto broth (control) and broth containing various concentrations of honey (10-100% wt/v). Microbial growth was assessed on solid plate media after 24 h incubation. Results Honey (30-70%) prevents growth of 10 µl specimens of all the isolates. Greater reduction in growth of E. coli was observed when cultured with S. aureus. Culturing of S. aureus with S. pyogenes, C. albicans, or E. coli increased its sensitivity to honey. S. aureus and S. pyogenes increased sensitivity of C. albicans to honey while E. coli and C. albicans decreased sensitivity of S. pyogenes. Conclusions It might be concluded that honey prevents and inhibits growth of single and polymicrobial pathogenic cultures. Polymicrobial culture affects growth of the isolates and increases their sensitivity to honey. PMID:24904656

Effects of natural honey on polymicrobial culture of various human pathogens.

PubMed

Al-Waili, Noori S; Al-Waili, Faiza S; Akmal, Mohammed; Ali, Amjed; Salom, Khelod Y; Al Ghamdi, Ahmad A

2014-05-12

Honey has a wide range of antimicrobial activity. All previous studies have considered honey's effect on a single microbe. The present study investigated activity of honey towards a high dose of single or polymicrobial culture. 10 µl specimens of Staphylococcus aureus (S. aureus), Streptococcus pyogenes (S. pyogenes), Escherichia coli (E. coli) and Candida albicans (C. albicans) were cultured in 10 ml of 10-100% (wt/v) honey diluted in broth. Six types of polymicrobial microbial cultures were prepared by culturing the isolates with each other onto broth (control) and broth containing various concentrations of honey (10-100% wt/v). Microbial growth was assessed on solid plate media after 24 h incubation. Honey (30-70%) prevents growth of 10 µl specimens of all the isolates. Greater reduction in growth of E. coli was observed when cultured with S. aureus. Culturing of S. aureus with S. pyogenes, C. albicans, or E. coli increased its sensitivity to honey. S. aureus and S. pyogenes increased sensitivity of C. albicans to honey while E. coli and C. albicans decreased sensitivity of S. pyogenes. It might be concluded that honey prevents and inhibits growth of single and polymicrobial pathogenic cultures. Polymicrobial culture affects growth of the isolates and increases their sensitivity to honey.

Multifocal bacterial osteomyelitis after varicella infection: a rare but dreaded complication of chickenpox.

PubMed

Gallach Sanchis, David; Doñate Pérez, Francisco; Jiménez Ortega, Plácido

2014-06-01

Chickenpox is an infectious disease common in children, which in most cases is benign toward the self-limited resolution. There are, however, serious systemic and musculoskeletal complications, especially in patients with immunosuppression. We report a case of multifocal skeletal muscle involvement, as a complication of chickenpox by Streptococcus pyogenes.

One-pot enzymatic glycan remodeling of a therapeutic monoclonal antibody by endoglycosidase S (Endo-S) from Streptococcus pyogenes.

PubMed

Tong, Xin; Li, Tiezheng; Orwenyo, Jared; Toonstra, Christian; Wang, Lai-Xi

2018-04-01

A facile, one-pot enzymatic glycan remodeling of antibody rituximab to produce homogeneous high-mannose and hybrid type antibody glycoforms is described. This method was based on the unique substrate specificity of the endoglycosidase S (Endo-S) from Streptococcus pyogenes. While Endo-S efficiently hydrolyzes the bi-antennary complex type IgG Fc N-glycans, we found that Endo-S did not hydrolyze the "ground state" high-mannose or hybrid glycoforms, and only slowly hydrolyzed the highly activated high-mannose or hybrid N-glycan oxazolines. Moreover, we found that wild-type Endo-S could efficiently use high-mannose or hybrid glycan oxazolines for transglycosylation without product hydrolysis. The combination of the remarkable difference in substrate specificity of Endo-S allows the deglycosylation of heterogeneous rituximab and the transglycosylation with glycan oxazoline to take place in one-pot without the need of isolating the deglycosylated intermediate or changing the enzyme to afford the high-mannose type, hybrid type, and some selectively modified truncated form of antibody glycoforms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Purification, crystallization and preliminary X-ray analysis of native and selenomethionine class I tagatose-1,6-bisphosphate aldolase from Streptococcus pyogenes.

PubMed

Liotard, Brigitte; Sygusch, Jurgen

2004-03-01

Tagatose-1,6-bisphosphate aldolase (EC 4.1.2.40) is situated at the branching of the tagatose-6-phosphate and Embden-Meyerhof-Parnas (glycolysis) metabolic pathways, where it catalyzes the reversible cleavage of tagatose-1,6-bisphosphate to dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. The recombinant protein from Streptococcus pyogenes was overexpressed in Escherichia coli in its native and selenomethionine-derivative forms and purified using ion-exchange and hydrophobic interaction chromatography. Orthorhombic crystals suitable for structural analysis were obtained by the hanging-drop vapour-diffusion method for both isoforms. The crystals belong to space group P2(1)2(1)2(1), with unit-cell parameters a = 63.7, b = 108.1, c = 238.7 A for the native form and a = 64.1, b = 108.3, c = 239.8 A for the selenomethionine derivative. The asymmetric unit contains four protomers, corresponding to a crystal volume per protein weight (V(M)) of 2.8 A(3) Da(-1) and a solvent content of 56% by volume.

Pathogen detection in milk samples by ligation detection reaction-mediated universal array method.

PubMed

Cremonesi, P; Pisoni, G; Severgnini, M; Consolandi, C; Moroni, P; Raschetti, M; Castiglioni, B

2009-07-01

This paper describes a new DNA chip, based on the use of a ligation detection reaction coupled to a universal array, developed to detect and analyze, directly from milk samples, microbial pathogens known to cause bovine, ovine, and caprine mastitis or to be responsible for foodborne intoxication or infection, or both. Probes were designed for the identification of 15 different bacterial groups: Staphylococcus aureus, Streptococcus agalactiae, nonaureus staphylococci, Streptococcus bovis, Streptococcus equi, Streptococcus canis, Streptococcus dysgalactiae, Streptococcus parauberis, Streptococcus uberis, Streptococcus pyogenes, Mycoplasma spp., Salmonella spp., Bacillus spp., Campylobacter spp., and Escherichia coli and related species. These groups were identified based on the 16S rRNA gene. For microarray validation, 22 strains from the American Type Culture Collection or other culture collections and 50 milk samples were tested. The results demonstrated high specificity, with sensitivity as low as 6 fmol. Moreover, the ligation detection reaction-universal array assay allowed for the identification of Mycoplasma spp. in a few hours, avoiding the long incubation times of traditional microbiological identification methods. The universal array described here is a versatile tool able to identify milk pathogens efficiently and rapidly.

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

PubMed

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

2016-01-01

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

Highly virulent M1 Streptococcus pyogenes isolates resistant to clindamycin.

PubMed

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.

Linkage of T3 and Cpa pilins in the Streptococcus pyogenes M3 pilus.

PubMed

Quigley, Bernard R; Zähner, Dorothea; Hatkoff, Matthew; Thanassi, David G; Scott, June R

2009-06-01

The important human pathogen Streptococcus pyogenes (group A streptococcus, GAS) initiates infection by pilus-mediated attachment to host tissue. Thus, the pilus is an excellent target for design of anti-infective strategies. The T3 pilus of GAS is composed of multiple covalently linked subunits of the T3 protein to which the two minor pilins, Cpa and OrfB, are covalently attached. Because the proteins of GAS pili do not contain either of the motifs required for pilus polymerization in other Gram-positive bacteria, we investigated the residues involved in their linkage. We show that linkage of Cpa to T3 by the sortase family transpeptidase SrtC2 requires the VPPTG motif in the cell wall-sorting signal of Cpa. We also demonstrate that K173 of T3 is required both for T3 polymerization and for attachment of Cpa to T3. Therefore, attachment of Cpa to K173 of a T3 subunit would block further addition of T3 subunits to this end of the growing pilus. This implies that Cpa is located exclusively at the pilus tip, a location supported by immunogold electron microscopy, and suggests that, as for well-studied pili on Gram-negative bacteria, the role of the pilus is to present the adhesin external to the bacterial capsule.

Reactive oxygen species induced by Streptococcus pyogenes invasion trigger apoptotic cell death in infected epithelial cells.

PubMed

Aikawa, Chihiro; Nozawa, Takashi; Maruyama, Fumito; Tsumoto, Kohei; Hamada, Shigeyuki; Nakagawa, Ichiro

2010-06-01

Streptococcus pyogenes (group A streptococcus, GAS), one of the most common pathogens of humans, attaches and invades into human pharyngeal or skin epithelial cells. We have previously reported that induction of apoptosis is associated with GAS invasion, which induces mitochondrial dysfunction and apoptotic cell death. We demonstrate here that GAS-induced apoptosis is mediated by reactive oxygen species (ROS) production. Both the induction of apoptosis and ROS production markedly increased upon invasion of wild-type GAS strain JRS4 into HeLa cells; however, the apoptotic response was not observed in fibronectin-binding protein F1-disrupted mutant SAM1-infected cells. In Bcl-2-overexpressing HeLa cells (HBD98-2-4), the induction of apoptosis, ROS production and mitochondrial dysfunction were significantly suppressed, whereas the numbers of invaded GAS was not different between HeLa (mock cells) and the HeLa HBD98-2-4 cells. Whereas Rac1 activation occurred during GAS invasion, ROS production in GAS-infected cells was clearly inhibited by transfection with the Rac1 mutants (L37 or V12L37), but not by the dominant active mutant (V12L61) or by the dominant negative mutant (N17). These observations indicate that GAS invasion triggers ROS production through Rac1 activation and generated ROS induced mitochondrial dysfunction leading to cellular apoptosis.

Molecular characterization and antibiotic resistance of Streptococcus dysgalactiae subspecies equisimilis isolated from patients with streptococcal toxic shock syndrome.

PubMed

Ikebe, T; Okuno, R; Sasaki, M; Kanda, Y; Otsuka, H; Kawahara, R; Ohya, H; Suzuki, M; Uchida, K; Nihonmatsu, H; Ohnishi, M

2018-02-01

Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multiorgan failure, and high mortality. Although STSS is mainly caused by Streptococcus pyogenes, group G streptococcus identified as S. dysgalactiae subsp. equisimilis (SDSE) causing STSS has also been reported; however, no study has analyzed >100 isolates of SDSE causing STSS. Therefore, we characterized the emm genotype of 173 SDSE isolates obtained from STSS patients in Japan during 2014-2016 and performed antimicrobial susceptibility testing using the broth microdilution method and emm gene typing. The predominant emm genotype was found to be stG6792, followed by stG485, stG245, stG10, stG6, and stG2078. These six genotypes constituted more than 75% of the STSS isolates. The proportion of each emm genotype in STSS isolates correlated with that in invasive isolates previously reported. We found that 16.2% of the isolates showed clindamycin resistance. The proportion of clindamycin-resistant SDSE isolates was significantly higher than that of S. pyogenes isolates. Thus, while treating STSS caused by SDSE, it is necessary to consider the possibility of clindamycin resistance and to ensure judicious use of the drug. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

[Molecular characterization of Streptococcus pyogenes from invasive disease and streptococcal toxic shock syndrome episodes].

PubMed

Traverso, F; Sparo, M; Rubio, V; Sáez Nieto, J A

2010-01-01

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 causing invasive disease and STSS. The isolates were recovered from blood cultures of hospitalized patients at Hospital Santamarina and Nueva Clínica Chacabuco, Tandil, Buenos Aires, Argentina between 12/2000-04/2005. Two pulse field gel electrophoretic patterns predominated. The most frequent one included 5 characteristic isolates of emm1-T1 type, toxin gene profile speA, speB, speF, speG and smeZ. The second pattern included 2 characteristic isolates of emm3-TNT type (speB, speF, speG). The other 3 isolates corresponded to types emm49-TNT (speB, speC, speF, speG), emm75-T25 (speB, speF, speG) and emm83-TNT (speB, speF, speG, ssa, smeZ). All isolates were susceptible to penicillin, cefotaxime, erythromycin, clindamycin, chloramphenicol, tetracycline and rifampicin. The data from the present study demonstrated genetic diversity among the strains. Types emm1 and emm3 were prevalent in invasive disease. The empirical treatment with the combination of penicillin and clindamicin is still valid.

Phenotypes and genotypes of erythromycin-resistant Streptococcus pyogenes strains isolated from invasive and non-invasive infections from Mexico and the USA during 1999–2010

PubMed Central

Villaseñor-Sierra, Alberto; Katahira, Eva; Jaramillo-Valdivia, Abril N.; de los Angeles Barajas-García, María; Bryant, Amy; Morfín-Otero, Rayo; Márquez-Díaz, Francisco; Tinoco, Juan Carlos; Sánchez-Corona, José; Stevens, Dennis L.

2012-01-01

Summary Objective To compare the prevalence, phenotypes, and genes responsible for erythromycin resistance among Streptococcus pyogenes isolates from Mexico and the USA. Methods Eighty-nine invasive and 378 non-invasive isolates from Mexico, plus 148 invasive, 21 non-invasive, and five unclassified isolates from the USA were studied. Susceptibilities to penicillin, erythromycin, clindamycin, ceftriaxone, and vancomycin were evaluated according to Clinical and Laboratory Standards Institute (CLSI) standards. Phenotypes of erythromycin resistance were identified by triple disk test, and screening for mefA, ermTR, and ermB genes was carried out by PCR. Results All isolates were susceptible to penicillin, ceftriaxone, and vancomycin. Erythromycin resistance was found in 4.9% of Mexican strains and 5.2% of USA strains. Phenotypes in Mexican strains were 95% M and 5% cMLS; in strains from the USA, phenotypes were 33.3% iMLS, 33.3% iMLS-D, and 33.3% M. Erythromycin resistance genes in strains from Mexico were mefA (95%) and ermB (5%); USA strains harbored ermTR (56%), mefA (33%), and none (11%). In Mexico, all erythromycin-resistant strains were non-invasive, whereas 89% of strains from the USA were invasive. Conclusions Erythromycin resistance continues to exist at low levels in both Mexico and the USA, although the genetic mechanisms responsible differ between the two nations. These genetic differences may be related to the invasive character of the S. pyogenes isolated. PMID:22217469

Inactivated and live, attenuated influenza vaccines protect mice against influenza:Streptococcus pyogenes super-infections

PubMed Central

Chaussee, Michael S.; Sandbulte, Heather R.; Schuneman, Margaret J.; DePaula, Frank P.; Addengast, Leslie A.; Schlenker, Evelyn H.; Huber, Victor C.

2011-01-01

Mortality associated with influenza virus super-infections is frequently due to secondary bacterial complications. To date, super-infections with Streptococcus pyogenes have been studied less extensively than those associated with S. pneumoniae. This is significant because a vaccine for S. pyogenes is not clinically available, leaving vaccination against influenza virus as our only means for preventing these super-infections. In this study, we directly compared immunity induced by two types of influenza vaccine, either inactivated influenza virus (IIV) or live, attenuated influenza virus (LAIV), for the ability to prevent super-infections. Our data demonstrate that both IIV and LAIV vaccines induce similar levels of serum antibodies, and that LAIV alone induces IgA expression at mucosal surfaces. Upon super-infection, both vaccines have the ability to limit the induction of pro-inflammatory cytokines within the lung, including IFN-γ which has been shown to contribute to mortality in previous models of super-infection. Limiting expression of these pro-inflammatory cytokines within the lungs subsequently limits recruitment of macrophages and neutrophils to pulmonary surfaces, and ultimately protects both IIV- and LAIV-vaccinated mice from mortality. Despite their overall survival, both IIV- and LAIV-vaccinated mice demonstrated levels of bacteria within the lung tissue to levels that are similar to those seen in unvaccinated mice. Thus, influenza virus:bacteria super-infections can be limited by vaccine-induced immunity against influenza virus, but the ability to prevent morbidity is not complete. PMID:21440037

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

PubMed

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.

Purification and characterization of ribosomal proteins L27 and L30 having antimicrobial activity produced by the Lactobacillus salivarius SGL 03.

PubMed

Pidutti, P; Federici, F; Brandi, J; Manna, L; Rizzi, E; Marini, U; Cecconi, D

2018-02-01

The aim of this study was to investigate the antimicrobial potential of proteins secreted by a new strain of Lactobacillus salivarius. The secretome of L. salivarius SGL 03 strain was analysed by gel-assisted fractionation and MS/MS to identify low-molecular-mass proteins. This strategy allowed us to identify 10 secreted proteins. Then, a combination of heterologous expression and agar well diffusion was used to characterize them as to their antimicrobial activity, mechanisms of action and stability. Our findings indicate that L27 and L30 proteins of the 50S ribosomal subunit have antimicrobial activity against Streptococcus pyogenes, Streptococcus uberis and Enterococcus faecium. In addition, both proteins are bactericidal against S. pyogenes and maintain their antimicrobial activity after different protease treatments, at acidic pH, after heat treatment, and if stored in a refrigerated ambient at least at 4°C. The overall results demonstrated that the L27 and L30 ribosomal proteins are of interest as new antimicrobial molecules to prevent the growth of S. pyogenes, S. uberis and E. faecium. Our results provide the first insight into the extra-ribosomal activity of L27 and L30 secreted proteins of L. salivarius. This study demonstrated the capacity of L. salivarius SGL 03 to produce antimicrobial molecules and suggested this strain as a promising probiotic candidate. © 2017 The Society for Applied Microbiology.

Identification of Enterococcus, Streptococcus, and Staphylococcus by Multivariate Analysis of Proton Magnetic Resonance Spectroscopic Data from Plate Cultures

PubMed Central

Bourne, Roger; Himmelreich, Uwe; Sharma, Ansuiya; Mountford, Carolyn; Sorrell, Tania

2001-01-01

A new fingerprinting technique with the potential for rapid identification of bacteria was developed by combining proton magnetic resonance spectroscopy (1H MRS) with multivariate statistical analysis. This resulted in an objective identification strategy for common clinical isolates belonging to the bacterial species Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, and the Streptococcus milleri group. Duplicate cultures of 104 different isolates were examined one or more times using 1H MRS. A total of 312 cultures were examined. An optimized classifier was developed using a bootstrapping process and a seven-group linear discriminant analysis to provide objective classification of the spectra. Identification of isolates was based on consistent high-probability classification of spectra from duplicate cultures and achieved 92% agreement with conventional methods of identification. Fewer than 1% of isolates were identified incorrectly. Identification of the remaining 7% of isolates was defined as indeterminate. PMID:11474013

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

PubMed

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 that the vaccine candidate likely would induce protection against the diverse strains worldwide.

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

PubMed

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

2015-10-01

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

PlyC, a bacteriophage endolysin that is internalized by epithelial cells and retains bacteriolytic activity against intracellular streptococci

USDA-ARS?s Scientific Manuscript database

PlyC, a bacteriophage-encoded endolysin, lyses Streptococcus pyogenes (Spy) on contact. Here, we demonstrate that PlyC is a potent agent for controlling intracellular Spy that often underlies refractory infections. We show that the PlyC holoenzyme, mediated by its PlyCB subunit, crosses epithelial...

Mutational Effects on Protein Folding Stability and Antigenicity: The Case of Streptococcal Pyrogenic Exotoxin A

DTIC Science & Technology

2003-01-01

1]. SPEA1 is a major virulence factor released by Streptococcus pyogenes and is associated with scarlet fever and severe invasive infections [1–4...Selander, J.M. Musser, Character- ization and clonal distribution of four alleles of the speA gene en- coding pyrogenic exotoxin A ( scarlet fever toxin

Varicella complicated by scarlet fever.

PubMed

Yavuz, Taner; Parlak, Ali Haydar; Kocabay, Kenan

2003-10-01

We report a 3-year-old boy with varicella complicated by cellulitis and scarlet fever. He developed a typical rash of scarlet fever following the onset of varicella. Streptococcus pyogenes was isolated from the ulcers due to varicella. The present case suggests that scarlet fever may rarely develop following varicella and should be considered in children with complicated varicella.

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

PubMed

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

2016-01-01

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

Patterns of isolation of common gram positive bacterial pathogens and their susceptibilities to antimicrobial agents in Jimma Hospital.

PubMed

Gebreselassie, Solomon

2002-04-01

Gram positive bacteria are frequently emerging as antibiotic resistant pathogens, causing serious infections than ever before in the ill and debilitated patients. The pattern of isolation and the antimicrobial susceptibilities of common Gram positive cocci including Staphylococcus aureus, coagulase negative staphylococcus (CoNS), Streptococcus pyogenes, Enterococcus species and Streptococcus pneumoniae was investigated between January 1997 and June 2000 in Jimma Hospital. Of the 500 specimens collected from children and adults, 116 (23.2%) consisted of one or more of the above organisms. The following strains: Staphylococcus aureus, 47 (40.5%), CoNS, 36 (31.0%), Streptococcus pneumoniae, 26 (22.4%) Streptococcus pyogenes, 5 (4.3%) and Streptococcus faecalis, 2(1.7%) were isolated from different specimens including pus, sputum, urine, stool, blood and oro/nasopharyngeal swabs of patients. The in vitro activities of 14 different antibiotics including penicillin G, ampicillin, cloxacillin, cephalothin, gentamicin, kanamycin, tetracycline, chloramphenicol, erythromycin, trimethoprim-sulfamethoxazole, streptomycin, methicillin, vancomycin and clindamycin was determined against the clinical bacterial isolates. The antimicrobial activities were evaluated by agar diffusion technique using Mueller-Hinton agar according to NCCLS recommendations. The majority of the pathogens, 59(50.9%) were recovered from upper respiratory tract infections and 17 (14.6%) from the lower respiratory tract. The resistance patterns of S. aureus, CoNS, S. pneumoniae and enterococci to penicillin was 91.5%, 94.4%, 7.7% and 100% respectively. Penicillin, ampicillin and cloxacillin showed low effects (< 60%) on both S. aureus and CoNS. Multi-drug resistance was observed in all the gram-positive isolates, especially higher in staphylococcus species. All isolates of S. aureus (100%) were susceptible to vancomycin, clindamycin and gentamicin. In order to reduce morbidity and mortality due to antibiotic resistance susceptibility testing should be performed for the proper management of bacterial infections. This entails the need for national surveillance to monitor antibiotic resistance in bacteria by susceptibility testing using reliable methods.

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

PubMed

Chiou, Chien-Shun; Wang, You-Wun; Chen, Pei-Ling; Wang, Wan-Ling; Wu, Ping-Fuai; Wei, Hsiao-Lun

2009-06-01

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. 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. 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.

Rapid degradation of Streptococcus pyogenes biofilms by PlyC, a bacteriophage-encoded endolysin.

PubMed

Shen, Yang; Köller, Thomas; Kreikemeyer, Bernd; Nelson, Daniel C

2013-08-01

Streptococcus pyogenes, or Group A streptococcus (GAS), has a propensity to colonize human tissues and form biofilms. Significantly, these biofilms are a contributing mechanism of antibiotic treatment failure in streptococcal disease. In this study, we evaluate a streptococcal-specific bacteriophage-encoded endolysin (PlyC), which is known to lyse planktonic streptococci, on both static and dynamic streptococcal biofilms. PlyC was benchmarked against antibiotics for MIC, MBC and minimum biofilm eradication concentration (MBEC). A biomass eradication assay based on crystal violet staining of the biofilm matrix was also used to quantify the anti-biofilm properties of PlyC. Finally, conventional fluorescence microscopy and laser scanning confocal microscopy were used to study the effects of PlyC on static and dynamic biofilms of GAS. PlyC and antibiotics had similar MIC (range 0.02-0.08 mg/L) and MBC (range 0.02-1.25 mg/L) values on planktonic GAS. However, when GAS grew in biofilms, the MBEC values for antibiotics rose to clinically resistant values (≥400 mg/L) whereas PlyC had MBEC values two orders of magnitude lower by mass and four orders of magnitude lower by molarity than the conventional antibiotics. Laser scanning confocal microscopy revealed that PlyC destroys the biofilm as it diffuses through the matrix in a time-dependent fashion. Our findings indicate that while streptococcal cells within a biofilm rapidly become refractory to traditional antibiotics, the biofilm matrix is readily destroyed by the lytic actions of PlyC.

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

PubMed

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.

Involvement of T6 pili in biofilm formation by serotype M6 Streptococcus pyogenes.

PubMed

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

2012-02-01

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

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

PubMed

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.

Phenotypes and genotypes of erythromycin-resistant Streptococcus pyogenes strains isolated from invasive and non-invasive infections from Mexico and the USA during 1999-2010.

PubMed

Villaseñor-Sierra, Alberto; Katahira, Eva; Jaramillo-Valdivia, Abril N; Barajas-García, María de los Angeles; Bryant, Amy; Morfín-Otero, Rayo; Márquez-Díaz, Francisco; Tinoco, Juan Carlos; Sánchez-Corona, José; Stevens, Dennis L

2012-03-01

To compare the prevalence, phenotypes, and genes responsible for erythromycin resistance among Streptococcus pyogenes isolates from Mexico and the USA. Eighty-nine invasive and 378 non-invasive isolates from Mexico, plus 148 invasive, 21 non-invasive, and five unclassified isolates from the USA were studied. Susceptibilities to penicillin, erythromycin, clindamycin, ceftriaxone, and vancomycin were evaluated according to Clinical and Laboratory Standards Institute (CLSI) standards. Phenotypes of erythromycin resistance were identified by triple disk test, and screening for mefA, ermTR, and ermB genes was carried out by PCR. All isolates were susceptible to penicillin, ceftriaxone, and vancomycin. Erythromycin resistance was found in 4.9% of Mexican strains and 5.2% of USA strains. Phenotypes in Mexican strains were 95% M and 5% cMLS; in strains from the USA, phenotypes were 33.3% iMLS, 33.3% iMLS-D, and 33.3% M. Erythromycin resistance genes in strains from Mexico were mefA (95%) and ermB (5%); USA strains harbored ermTR (56%), mefA (33%), and none (11%). In Mexico, all erythromycin-resistant strains were non-invasive, whereas 89% of strains from the USA were invasive. Erythromycin resistance continues to exist at low levels in both Mexico and the USA, although the genetic mechanisms responsible differ between the two nations. These genetic differences may be related to the invasive character of the S. pyogenes isolated. Copyright © 2011 International Society for Infectious Diseases. All rights reserved.

Streptococcus pyogenes strains containing emm12 and emm55 possess a novel gene coding for distantly related SIC protein.

PubMed

Hartas, J; Sriprakash, K S

1999-01-01

Streptococcus pyogenes infection and acute glomerulonephritis (AGN), a non-suppurtave disease, are endemic in the Aboriginal people of the Northern Territory (NT) of Australia. Vir typing, a locus-specific polymerase chain reaction (PCR)-based typing method [Gardiner, Hartas, Currie et al PCR Meth Appl 1995 4: 288-93], has revealed high divergence among the NT streptococcal strains. A total of 76 Vir types (VTs) representing about 95% of the NT isolates were screened for sic, a gene for streptococcal inhibitor of complement function, by PCR and hybridization. This revealed that seven VTs are positive for sic, and there are two classes of the gene: those closely related to sic (CRS) originally described by Akesson, Sjoholm & Bjorck [ J. Biol. Chem. 1996 271: 1081-8] and those distantly related to sic (DRS). Among the CRS-positive VTs, VT16, VT78 and VT91 have emm (gene for M protein) encoding type 1 M protein or related specificity, and VT8 and VT101 contain emm57 or related alleles. Chromosomal location of CRS in emm57 is different from that in emm1 or related strains. The DRS-positive VT18 and VT52 contained emm55 and emm12 respectively, which are phylogenetically related. Strains of S. pyogenes types 1, 12, 55 and 57 are known to be associated with AGN. Restricted distribution of CRS and DRS among the M types historically associated with AGN suggests that these sic alleles may have a role in AGN pathogenesis. Copyright 1999 Academic Press.

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

PubMed Central

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

2013-01-01

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

Molecular biology of Group A Streptococcus and its implications in vaccine strategies.

PubMed

Brahmadathan, N K

2017-01-01

Infections due to Streptococcus pyogenes and their complications are a problem of major concern in many countries, including India. Primary prophylaxis with benzathine penicillin is the key to control and prevent sequelae such as acute rheumatic fever and rheumatic heart disease (RF/RHD) or post-streptococcal glomerulonephritis (PSGN). Non-compliance to prophylaxis due to fear of injection and anaphylaxis is major issues in RF/RHD control in India and leads to continued high prevalence of infection and post-streptococcal sequelae. Differing reports on the efficacy of two weekly, three weekly or monthly injections raise questions on the actual dosages to be administered. Availability of more effective antibiotics with better dosages has replaced the use of penicillin; hence, companies are reluctant to manufacture penicillin preparations in India. It is in this context that a concept of a Group A streptococci vaccine is looked at and whether or not a globally designed vaccine will be useful in the Indian context. Modern molecular techniques and genomic analysis of S. pyogenes have identified many molecules as vaccine candidates among which the M-protein has attracted the most attention. High diversity of M (emm) types in endemic regions raises questions about the efficacy of such a vaccine. A recent 30-valent M-protein-based vaccine that elicits antibodies to homologous as well as non-vaccine M types looks promising. This review will discuss the genomics of S. pyogenes, the various candidate vaccine molecules and highlight their efficacy in the Indian context where control of post-streptococcal sequelae remains a challenge.

Multiple Length Peptide-Pheromone Variants Produced by Streptococcus pyogenes Directly Bind Rgg Proteins to Confer Transcriptional Regulation*

PubMed Central

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

2014-01-01

Streptococcus pyogenes, a human-restricted pathogen, accounts for substantial mortality related to infections worldwide. Recent studies indicate that streptococci produce and respond to several secreted peptide signaling molecules (pheromones), including those known as short hydrophobic peptides (SHPs), to regulate gene expression by a quorum-sensing mechanism. Upon transport into the bacterial cell, pheromones bind to and modulate activity of receptor proteins belonging to the Rgg family of transcription factors. Previously, we reported biofilm regulation by the Rgg2/3 quorum-sensing circuit in S. pyogenes. The aim of this study was to identify the composition of mature pheromones from cell-free culture supernatants that facilitate biofilm formation. Bioluminescent reporters were employed to detect active pheromones in culture supernatants fractionated by reverse-phase chromatography, and mass spectrometry was used to characterize their properties. Surprisingly, multiple SHPs that varied by length were detected. Synthetic peptides of each variant were tested individually using bioluminescence reporters and biofilm growth assays, and although activities differed widely among the group, peptides comprising the C-terminal eight amino acids of the full-length native peptide were most active. Direct Rgg/SHP interactions were determined using a fluorescence polarization assay that utilized FITC-labeled peptide ligands. Peptide receptor affinities were seen to be as low as 500 nm and their binding affinities directly correlated with observed bioactivity. Revelation of naturally produced pheromones along with determination of their affinity for cognate receptors are important steps forward in designing compounds whose purpose is positioned for future therapeutics aimed at treating infections through the interference of bacterial communication. PMID:24958729

Group A beta-hemolytic streptococcal hemorrhagic colitis complicated with pharyngitis and impetigo.

PubMed

Isozaki, Atsushi; Matsubara, Keiko; Yui, Takako; Kobayashi, Kenji; Kawano, Yutaka

2007-12-01

A 6-year-old boy with bloody diarrhea was diagnosed with group A beta-hemolytic streptococcal hemorrhagic colitis. Complications included pharyngitis and impetigo, both caused by the same organisms. In addition to being isolated from stools, Streptococcus pyogenes was also isolated from skin lesions. Furthermore, a rapid group A streptococcal antigen test by throat swab was also positive. Hemorrhagic colitis caused by group A beta-hemolytic streptococcus is extremely rare, and much rarer are its complications with pharyngitis and impetigo. Compared with findings in reports of group A beta-hemolytic streptococcal proctitis and perianal and perineal diseases, this case suggests a distinct pathogenesis for hemorrhagic colitis.

The effects of titanium nitride-coating on the topographic and biological features of TPS implant surfaces.

PubMed

Annunziata, Marco; Oliva, Adriana; Basile, Maria Assunta; Giordano, Michele; Mazzola, Nello; Rizzo, Antonietta; Lanza, Alessandro; Guida, Luigi

2011-11-01

Titanium nitride (TiN) coating has been proposed as an adjunctive surface treatment aimed to increase the physico-mechanical and aesthetic properties of dental implants. In this study we investigated the surface characteristics of TiN-coated titanium plasma sprayed (TiN-TPS) and uncoated titanium plasma sprayed (TPS) surfaces and their biological features towards both primary human bone marrow mesenchymal stem cells (BM-MSC) and bacterial cultures. 15 mm×1 mm TPS and TiN-TPS disks (P.H.I. s.r.l., San Vittore Olona, Milano, Italy) were topographically analysed by confocal optical profilometry. Primary human BM-MSC were obtained from healthy donors, isolated and expanded. Cells were seeded on the titanium disks and cell adhesion, proliferation, protein synthesis and osteoblastic differentiation in terms of alkaline phosphatase activity, osteocalcin synthesis and extracellular mineralization, were evaluated. Furthermore, adhesion and proliferation of Streptococcus pyogenes and Streptococcus sanguinis on both surfaces were also analysed. TiN-TPS disks showed a decreased roughness (about 50%, p < 0.05) and a decreased bacterial adhesion and proliferation compared to TPS ones. No difference (p > 0.05) in terms of BM-MSC adhesion, proliferation and osteoblastic differentiation between TPS and TiN-TPS surfaces was found. TiN coating showed to modify the topographical characteristics of TPS titanium surfaces and to significantly reduce bacterial adhesion and proliferation, although maintaining their biological affinity towards bone cell precursors. Copyright © 2011 Elsevier Ltd. All rights reserved.

Scarlet Fever Upsurge in England and Molecular-Genetic Analysis in North-West London, 2014.

PubMed

Turner, Claire E; Pyzio, Marta; Song, Bonita; Lamagni, Theresa; Meltzer, Margie; Chow, J Yimmy; Efstratiou, Androulla; Curtis, Sally; Sriskandan, Shiranee

2016-06-01

Scarlet fever notifications surged across the United Kingdom in spring 2014. Molecular epidemiologic investigation of Streptococcus pyogenes infections in North-West London highlighted increased emm4 and emm3 infections coincident with the upsurge. Unlike outbreaks in other countries, antimicrobial resistance was uncommon, highlighting an urgent need to better understand the drivers of scarlet fever activity.

A newly discovered Bordetella species carries a transcriptionally active CRISPR-Cas with a small Cas9 endonuclease

USDA-ARS?s Scientific Manuscript database

The Cas9 endonuclease of the Type II-a clustered regularly interspersed short palindromic repeats (CRISPR), of Streptococcus pyogenes (SpCas9) has been adapted as a widely used tool for genome editing and genome engineering. Herein, we describe a gene encoding a novel Cas9 ortholog (BpsuCas9) and th...

In Vitro Susceptibilities of Shigella flexneri and Streptococcus pyogenes to Inner Gel of Aloe barbadensis Miller

PubMed Central

Ferro, Valerie A.; Bradbury, Fiona; Cameron, Pamela; Shakir, Eisin; Rahman, Sabita R.; Stimson, William H.

2003-01-01

Aloe barbadensis Miller (or Aloe vera) has widespread use in health products, and despite numerous reports on the whole plant, little work has been performed on the inner gel, which has been used extensively in these products. This report describes the in vitro susceptibilities of two bacteria to this component. PMID:12604556

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2012-09-05

Cysteine protease SpeB is secreted from Streptococcus pyogenes and has been studied as a potential virulence factor since its identification almost 70 years ago. Here, we report the crystal structures of apo mature SpeB to 1.06 {angstrom} resolution as well as complexes with the general cysteine protease inhibitor trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and a novel substrate mimetic peptide inhibitor. These structures uncover conformational changes associated with maturation of SpeB from the inactive zymogen to its active form and identify the residues required for substrate binding. With the use of a newly developed fluorogenic tripeptide substrate to measure SpeB activity, we determined IC{sub 50}more » 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.« less

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

PubMed

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

2015-01-01

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

Generation of efficient mutants of endoglycosidase from Streptococcus pyogenes and their application in a novel one-pot transglycosylation reaction for antibody modification.

PubMed

Iwamoto, Mitsuhiro; Sekiguchi, Yukiko; Nakamura, Kensuke; Kawaguchi, Yoshirou; Honda, Takeshi; Hasegawa, Jun

2018-01-01

The fine structures of Fc N-glycan modulate the biological functions and physicochemical properties of antibodies. By remodeling N-glycan to obtain a homogeneous glycoform or chemically modified glycan, antibody characteristics can be controlled or modified. Such remodeling can be achieved by transglycosylation reactions using a mutant of endoglycosidase from Streptococcus pyogenes (Endo-S) and glycan oxazoline. In this study, we generated improved mutants of Endo-S by introducing additional mutations to the D233Q mutant. Notably, Endo-S D233Q/Q303L, D233Q/E350Q, and several other mutations resulted in transglycosylation efficiencies exceeding 90%, with a single-digit donor-to-substrate ratio of five, and D233Q/Y402F/D405A and several other mutations resulted in slightly reduced transglycosylation efficiencies accompanied by no detectable hydrolysis activity for 48 h. We further demonstrated that the combined use of mutants of Endo-S with Endo-M or Endo-CC, endoglycosidases from Mucor hiemalis and Coprinopsis cinerea, enables one-pot transglycosylation from sialoglycopeptide to antibodies. This novel reaction enables glycosylation remodeling of antibodies, without the chemical synthesis of oxazoline in advance or in situ.

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

PubMed Central

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

2014-01-01

The human pathogen Streptococcus pyogenes produces pili that are essential for adhesion to host surface receptors. Cpa, the adhesin at the pilus tip, was recently shown to have a thioester-containing domain. The thioester bond is believed to be important in adhesion, implying a mechanism of covalent attachment analogous to that used by human complement factors. Here, we have characterized a second active thioester-containing domain on Cpa, the N-terminal domain of Cpa (CpaN). Expression of CpaN in Escherichia coli gave covalently linked dimers. These were shown by x-ray crystallography and mass spectrometry to comprise two CpaN molecules cross-linked by the polyamine spermidine following reaction with the thioester bonds. This cross-linked CpaN dimer provides a model for the covalent attachment of Cpa to target receptors and thus the streptococcal pilus to host cells. Similar thioester domains were identified in cell wall proteins of other Gram-positive pathogens, suggesting that thioester domains are more widely used and provide a mechanism of adhesion by covalent bonding to target molecules on host cells that mimics that used by the human complement system to eliminate pathogens. PMID:24220033

High-level fluorescence labeling of gram-positive pathogens.

PubMed

Aymanns, Simone; Mauerer, Stefanie; van Zandbergen, Ger; Wolz, Christiane; Spellerberg, Barbara

2011-01-01

Fluorescence labeling of bacterial pathogens has a broad range of interesting applications including the observation of living bacteria within host cells. We constructed a novel vector based on the E. coli streptococcal shuttle plasmid pAT28 that can propagate in numerous bacterial species from different genera. The plasmid harbors a promoterless copy of the green fluorescent variant gene egfp under the control of the CAMP-factor gene (cfb) promoter of Streptococcus agalactiae and was designated pBSU101. Upon transfer of the plasmid into streptococci, the bacteria show a distinct and easily detectable fluorescence using a standard fluorescence microscope and quantification by FACS-analysis demonstrated values that were 10-50 times increased over the respective controls. To assess the suitability of the construct for high efficiency fluorescence labeling in different gram-positive pathogens, numerous species were transformed. We successfully labeled Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus dysgalactiae subsp. equisimilis, Enterococcus faecalis, Enterococcus faecium, Streptococcus mutans, Streptococcus anginosus and Staphylococcus aureus strains utilizing the EGFP reporter plasmid pBSU101. In all of these species the presence of the cfb promoter construct resulted in high-level EGFP expression that could be further increased by growing the streptococcal and enterococcal cultures under high oxygen conditions through continuous aeration.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, C.; Coggill, P.; Bateman, A.

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. Wemore » 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.« less

Scarlet Fever Upsurge in England and Molecular-Genetic Analysis in North-West London, 2014

PubMed Central

Turner, Claire E.; Pyzio, Marta; Song, Bonita; Lamagni, Theresa; Meltzer, Margie; Chow, J. Yimmy; Efstratiou, Androulla; Curtis, Sally

2016-01-01

Scarlet fever notifications surged across the United Kingdom in spring 2014. Molecular epidemiologic investigation of Streptococcus pyogenes infections in North-West London highlighted increased emm4 and emm3 infections coincident with the upsurge. Unlike outbreaks in other countries, antimicrobial resistance was uncommon, highlighting an urgent need to better understand the drivers of scarlet fever activity. PMID:27192393

[M protein gene (emm) typing of Streptococcus pyogenes].

PubMed

Katsukawa, Chihiro; Tamaru, Aki; Morikawa, Yoshiro; Oda, Kimiko

2002-04-01

T-agglutination typing and M protein gene (emm) typing were determined on the isolates of Streptococcus pyogenes taken from patients in Osaka and neighboring districts during 1996-2000. A total of 701 isolates were classified to 15 kinds of T types and type untypable. In all isolates, T 12 was revealed as the most dominant serotype, followed by T1, T4 and T2. The isolation rates of T 12 strains were high through these five years, and these of T1 or T4 strains formed epidemic waves showing the peak to be from 1997 to 1999 and 1998 to 2000, respectively. These of T2 strains were high in 1996 and 1997 and decreased rapidly. In 2000 T2 strain has not been detected. A total of 304 isolates were examined for emm typing. We are able to determine the emm type of all isolates including T-untypable (UT) isolates and to classify 21 kinds of emm types. T1, T2, T4, T6, T9, T11, T12, T22, T25 strains exhibited one T-type and emm type pattern association respectively such as T1/emm1, T2/emm2, T4/emm4, T6/emm6, T9/emm9, T11/emm11, T12/emm12, T22/emm22, T25/emm75. Whereas T13 strains had varied T/emm pattern associations such as T13/emm73, T13/emm77, T13/emm101. Similarly, T28, TB3264, UT had varied T/emm pattern associations. emm28 and emm87 were seen in T28, emm89 and emm94 in TB3264, emm2, emm12, emm22, emm58, emm75, emm77 and emm112 in UT. The emm typing method did not require many kinds of M typing antisera, and were successful by using the two highly conserved primers to amplify the emm gene and direct sequencing. Therefore, this method was a useful tool for typing Streptococcus pyogenes isolates.

Antibody classes & subclasses induced by mucosal immunization of mice with Streptococcus pyogenes M6 protein & oligodeoxynucleotides containing CpG motifs.

PubMed

Teloni, R; von Hunolstein, C; Mariotti, S; Donati, S; Orefici, G; Nisini, R

2004-05-01

Type-specific antibodies against M protein are critical for human protection as they enhance phagocytosis and are protective. An ideal vaccine for the protection against Streptococcus pyogenes would warrant mucosal immunity, but mucosally administered M-protein has been shown to be poorly immunogenic in animals. We used a recombinant M type 6 protein to immunize mice in the presence of synthetic oligodeoxynucleotides containing CpG motifs (immunostimulatory sequences: ISS) or cholera toxin (CT) to explore its possible usage in a mucosal vaccine. Mice were immunized by intranasal (in) or intradermal (id) administration with four doses at weekly intervals of M6-protein (10 microg/mouse) with or without adjuvant (ISS, 10 microg/mouse or CT, 0,5 microg/mouse). M6 specific antibodies were measured by enzyme linked immunosorbent assay using class and subclass specific monoclonal antibodies. The use of ISS induced an impressive anti M-protein serum IgG response but when id administered was not detectable in the absence of adjuvant. When used in, M-protein in the presence of both ISS and CT induced anti M-protein IgA in the bronchoalveolar lavage, as well as specific IgG in the serum. IgG were able to react with serotype M6 strains of S. pyogenes. The level of antibodies obtained by immunizing mice in with M-protein and CT was higher in comparison to M-protein and ISS. The analysis of anti-M protein specific IgG subclasses showed high levels of IgG1, IgG2a and IgG2b, and low levels of IgG3 when ISS were used as adjuvant. Thus, in the presence of ISS, the ratio IgG2a/IgG1 and (IgG2a+IgG3)/IgG1 >1 indicated a type 1-like response obtained both in mucosally or systemically vaccinated mice. Our study offers a reproducible model of anti-M protein vaccination that could be applied to test new antigenic formulations to induce an anti-group A Streptococcus (GAS) vaccination suitable for protection against the different diseases caused by this bacterium.

Differential induction of pro- and anti-inflammatory cytokines in whole blood by bacteria: effects of antibiotic treatment.

PubMed

Frieling, J T; Mulder, J A; Hendriks, T; Curfs, J H; van der Linden, C J; Sauerwein, R W

1997-07-01

The in vitro production of interleukin-1beta (IL-1beta), IL-6, and the IL-1 receptor antagonist (IL-1ra) in whole blood upon stimulation with different bacterial strains was measured to study the possible relationship between disease severity and the cytokine-inducing capacities of these strains. Escherichia coli, Neisseria meningitidis, Neisseria gonorrhoeae, Bacteroides fragilis, Capnocytophaga canimorsus, Staphylococcus aureus, Enterococcus faecalis, Streptococcus pneumoniae, and Streptococcus pyogenes induced the cytokines IL-1beta, IL-6, and IL-1ra. Gram-negative bacteria induced significantly higher levels of proinflammatory cytokine production than gram-positive bacteria. These differences were less pronounced for the anti-inflammatory cytokine IL-1ra. In addition, blood was stimulated with E. coli killed by different antibiotics to study the effect of the antibiotics on the cytokine-inducing capacity of the bacterial culture. E. coli treated with cefuroxime and gentamicin induced higher levels of IL-1beta and IL-6 production but levels of IL-1ra production similar to that of heat-killed E. coli. In contrast, ciprofloxacin- and imipenem-cilastatin-mediated killing showed a decreased or similar level of induction of cytokine production as compared to that by heat-killed E. coli; polymyxin B decreased the level of production of the cytokines.

Targeted Proteomics and Absolute Protein Quantification for the Construction of a Stoichiometric Host-Pathogen Surface Density Model*

PubMed Central

Sjöholm, Kristoffer; Kilsgård, Ola; Teleman, Johan; Happonen, Lotta; Malmström, Lars; Malmström, Johan

2017-01-01

Sepsis is a systemic immune response responsible for considerable morbidity and mortality. Molecular modeling of host-pathogen interactions in the disease state represents a promising strategy to define molecular events of importance for the transition from superficial to invasive infectious diseases. Here we used the Gram-positive bacterium Streptococcus pyogenes as a model system to establish a mass spectrometry based workflow for the construction of a stoichiometric surface density model between the S. pyogenes surface, the surface virulence factor M-protein, and adhered human blood plasma proteins. The workflow relies on stable isotope labeled reference peptides and selected reaction monitoring mass spectrometry analysis of a wild-type strain and an M-protein deficient mutant strain, to generate absolutely quantified protein stoichiometry ratios between S. pyogenes and interacting plasma proteins. The stoichiometry ratios in combination with a novel targeted mass spectrometry method to measure cell numbers enabled the construction of a stoichiometric surface density model using protein structures available from the protein data bank. The model outlines the topology and density of the host-pathogen protein interaction network on the S. pyogenes bacterial surface, revealing a dense and highly organized protein interaction network. Removal of the M-protein from S. pyogenes introduces a drastic change in the network topology, validated by electron microscopy. We propose that the stoichiometric surface density model of S. pyogenes in human blood plasma represents a scalable framework that can continuously be refined with the emergence of new results. Future integration of new results will improve the understanding of protein-protein interactions and their importance for bacterial virulence. Furthermore, we anticipate that the general properties of the developed workflow will facilitate the production of stoichiometric surface density models for other types of host-pathogen interactions. PMID:28183813

[Postoperative necrotizing fasciitis: a rare and fatal complication].

PubMed

Ghezala, Hassen Ben; Feriani, Najla

2016-01-01

Postoperative parietal complications can be exceptionally severe and serious threatening vital prognosis. Necrotizing fasciitis is a rare infection of the skin and deep subcutaneous tissues, spreading along fascia and adipose tissue. It is mainly caused by group A streptococcus (streptococcus pyogenes) but also by other bacteria such as Vibrio vulnificus, Clostridium perfringens or Bacteroides fragilis. Necrotizing fasciitis is a real surgical and medical emergency. We report, in this study, a very rare case of abdominal parietal gangrene occurring in a 75-year-old woman on the fifth day after surgery for an ovarian cyst. Evolution was marked by occurrence of a refractory septic shock with a rapidly fatal course on the third day of management.

A clone of the emergent Streptococcus pyogenes emm89 clade responsible for a large outbreak in a post-surgery oncology unit in France.

PubMed

Plainvert, Céline; Longo, Magalie; Seringe, Elise; Saintpierre, Benjamin; Sauvage, Elisabeth; Ma, Laurence; Beghain, Johann; Dmytruk, Nicolas; Collobert, Gislène; Hernandez, Eric; Manuel, Christian; Astagneau, Pascal; Glaser, Philippe; Ariey, Frédéric; Poyart, Claire; Fouet, Agnès

2018-06-23

An outbreak of nosocomial infections due to Streptococcus pyogenes (Group A Streptococcus; GAS) occurred in a post-surgery oncology unit and concerned more than 60 patients and lasted 20 months despite enhanced infection control and prophylaxis measures. All GAS strains were characterized (emm genotype, toxin gene profile and pulse-field gel electrophoresis subtype). Selected strains were sequenced and phylogenetic relationship established. Capacity to form biofilm and interaction with human pulmonary epithelial cells and macrophages were determined. Twenty-six GAS strains responsible for invasive infections (II) and 57 for non-II or colonization were isolated from patients (n = 66) or healthcare workers (n = 13). Seventy strains shared the same molecular markers and 69 the same PFGE pattern; 56 were sequenced. They all belonged to the emerging emm89 clade 3; all but 1 were clonal. Whole genome sequencing identified 43 genetic profiles with sporadic mutations in regulatory genes and acquired mutations in 2 structural genes. Except for two regulatory gene mutants, all strains tested had the same biofilm formation capacity and displayed similar adherence and invasion of pulmonary epithelial cells and phagocytosis and survival in human macrophages. This large outbreak of GAS infection in a post-surgery oncology unit, a setting that contains highly susceptible patients, arose from a strain of the emergent emm89 clade. No relationship between punctual or acquired mutations, invasive status, and strain phenotypic characteristics was found. Noteworthy, the phenotypic characteristics of this clone account for its emergence and its remarkable capacity to elicit outbreaks.

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

PubMed

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

2014-07-01

Group A streptococcus (GAS; Streptococcus pyogenes) is a Gram-positive human pathogen that causes a broad range of diseases ranging from acute pharyngitis to the poststreptococcal sequelae of acute rheumatic fever. GAS pili are highly diverse, long protein polymers that extend from the cell surface. They have multiple roles in infection and are promising candidates for vaccine development. This study describes the structure of the T6 backbone pilin (BP; Lancefield T-antigen) from the important M6 serotype. The structure reveals a modular arrangement of three tandem immunoglobulin-like domains, two with internal isopeptide bonds. The T6 pilin lysine, essential for polymerization, is located in a novel VAKS motif that is structurally homologous to the canonical YPKN pilin lysine in other three- and four-domain Gram-positive pilins. The T6 structure also highlights a conserved pilin core whose surface is decorated with highly variable loops and extensions. Comparison to other Gram-positive BPs shows that many of the largest variable extensions are found in conserved locations. Studies with sera from patients diagnosed with GAS-associated acute rheumatic fever showed that each of the three T6 domains, and the largest of the variable extensions (V8), are targeted by IgG during infection in vivo. Although the GAS BP show large variations in size and sequence, the modular nature of the pilus proteins revealed by the T6 structure may aid the future design of a pilus-based vaccine. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

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

PubMed Central

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

2001-01-01

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

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

PubMed Central

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

2012-01-01

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

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

PubMed Central

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

2013-01-01

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 amino acids from GAS, when conjugated to DT, has been shown to protect mice against a lethal GAS challenge. Protection has been previously shown to be antibody-mediated. J8 does not contain a dominant GAS-specific T-cell epitope. The current study examined long-term antibody memory and dissected the role of B and T-cells. Our results demonstrated that vaccination generates specific memory B-cells and long-lasting antibody responses. The memory B-cell response can be activated following boost with antigen 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 memory B-cells but can be provided by naïve 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 antibody response at the time of infection. These studies significantly strengthen previous findings, which showed that protection by the J8-DT vaccine is antibody-mediated and suggest that in vaccine design for other organisms the source of T-cell help for antibody responses need not be limited to sequences from the organism itself. PMID:23401589

Streptococcus dysgalactiae subsp. dysgalactiae isolated from milk of the bovine udder as emerging pathogens: In vitro and in vivo infection of human cells and zebrafish as biological models.

PubMed

Alves-Barroco, Cinthia; Roma-Rodrigues, Catarina; Raposo, Luís R; Brás, Catarina; Diniz, Mário; Caço, João; Costa, Pedro M; Santos-Sanches, Ilda; Fernandes, Alexandra R

2018-03-25

Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) is a major cause of bovine mastitis and has been regarded as an animal-restricted pathogen, although rare infections have been described in humans. Previous studies revealed the presence of virulence genes encoded by phages of the human pathogen Group A Streptococcus pyogenes (GAS) in SDSD isolated from the milk of bovine udder with mastitis. The isolates SDSD VSD5 and VSD13 could adhere and internalize human primary keratinocyte cells, suggesting a possible human infection potential of bovine isolates. In this work, the in vitro and in vivo potential of SDSD to internalize/adhere human cells of the respiratory track and zebrafish as biological models was evaluated. Our results showed that, in vitro, bovine SDSD strains could interact and internalize human respiratory cell lines and that this internalization was dependent on an active transport mechanism and that, in vivo, SDSD are able to cause invasive infections producing zebrafish morbidity and mortality. The infectious potential of these isolates showed to be isolate-specific and appeared to be independent of the presence or absence of GAS phage-encoded virulence genes. Although the infection ability of the bovine SDSD strains was not as strong as the human pathogenic S. pyogenes in the zebrafish model, results suggested that these SDSD isolates are able to interact with human cells and infect zebrafish, a vertebrate infectious model, emerging as pathogens with zoonotic capability. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

[Species and quantitative characteristics of pharyngeal mucosa microflora in pregnant women].

PubMed

Meshcheriakova, A K; Kostinov, M P; Magarshak, O O; Zaĭtseva, E V

2014-01-01

Species and quantitative characteristics of upper respiratory tract (URT) mucosa microflora in women at gestation period. The results of a bacteriological study of 68 samples of mucus from posterior pharyngeal wall in women at gestation period (from 14 weeks), 52 of those--from pregnant women with acute respiratory infection (ARI) symptoms and 16--from women without signs of disease, are presented. Qualitative and quantitative composition of microflora was studied by a generally accepted bacteriological method. During primary bacteriological study 111 microorganism cultures were isolated. 88 (79.3%) of strains belonged to Gram-positive flora, 20 (18.0%)--to Gram-negative, and Candida genus fungi constituted 3 (2.7%) isolates. Streptococcus pyogenes and Moraxella catarrhalis were isolated from pregnant women with ARI signs at 23.1% and 5.8% frequency of occurrence, respectively. A higher detectability of Staphylococcus aureus--in 31.3% and Candida spp.--in 6.3% of women who did not complain as opposed to patients with URT lesions (in 21.2 and 3.9%, respectively) was determined. In patients without ARI signs the amount of bacteria did not exceed 10(5)--10(6) CFU/ml, in pregnant women with ARI diagnosis in 8 of 52 cases semination of pharyngeal mucuswas observed--10(7)--10(8) CFU/ml. Prevalence of S. aureus, Streptococcus agalactiae, S. pyogenes, Streptococcus mutans in composition of pharyngeal mucus microflora of pregnant women both with URT lesion signs and without them was shown, however the degree of semination by pathogens in the groups was different that determined the severity of disease manifestations.

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

PubMed

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

2013-01-01

Streptococcal toxic shock syndrome (STSS) is an uncommon but life-threatening disease caused by Streptococcus pyogenes. 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. 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). 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.

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

PubMed Central

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

2013-01-01

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

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

PubMed

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

2013-12-01

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

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

PubMed

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

2014-08-08

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.

New non-alcoholic formulation for hand disinfection.

PubMed

Biagi, Marco; Giachetti, Daniela; Miraldi, Elisabetta; Figura, Natale

2014-04-01

Hand washing is considered as the single most important strategy to prevent infections. World health organization (WHO) defines hand hygiene as a primary issue of personal care with particular reference to hospital personnel and health facility workers. In this work, we investigated a new combination for hand disinfection as an alternative to alcohol-based and chlorhexidine products. The new combination of 5-pyrrolidone-2-carboxylic acid (PCA) and copper sulphate pentahydrate (CS) was tested upon different bacterial species that normally colonize hands, including Staphylococcus aureus, methicillin resistant S. aureus (MR S. aureus), Staphylococcus epidermidis, multidrug resistant S. epidermidis (MDR S. epidermidis), Streptococcus pyogenes, Streptococcus agalactiae, Escherichia coli, Candida albicans and three clinical isolates: MR S. aureus, MDR S. epidermidis, and an E. coli strain. Minimal inhibitory concentrations (MICs), Minimal bactericidal concentrations (MBCs), fractional inhibitory concentration (FIC) indices, and fractional bactericidal concentration (FBC) indices were evaluated. Ethanol 70% V/V, isopropanol 60% V/V, and 4% w/V chlorhexidine solution were used as reference hand disinfectants. Copper sulphate pentahydrate was very effective against all tested microorganisms: The MIC and MBC for CS ranged from 781 mg/l against S. pyogenes to 12500 mg/l against E. coli strains and C. albicans. In addition, PCA exhibited a good antimicrobial activity, in particular, against S. pyogenes and S. agalactiae. The combination of CS and PCA showed a strong synergistic effect and all FIC indices were ≤0·500. The combination of CS and PCA were more effective than ethanol 70% V/V and isopropanol 60% V/V. In addition to antimicrobial activity, the new formulation possesses peculiar features such as residual activity and moisturizing effect. This work identifies a new strategy for hand disinfection.

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

PubMed

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

2015-07-01

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

Development of an opsonophagocytic killing assay for group a streptococcus.

PubMed

Jones, Scott; Moreland, Nicole J; Zancolli, Marta; Raynes, Jeremy; Loh, Jacelyn M S; Smeesters, Pierre R; Sriskandan, Shiranee; Carapetis, Jonathan R; Fraser, John D; Goldblatt, David

2018-05-15

Group A Streptococcus (GAS) or Streptococcus pyogenes is responsible for an estimated 500,000 deaths worldwide each year. Protection against GAS infection is thought to be mediated by phagocytosis, enhanced by bacteria-specific antibody. There are no licenced GAS vaccines, despite many promising candidates in preclinical and early stage clinical development, the most advanced of which are based on the GAS M-protein. Vaccine progress has been hindered, in part, by the lack of a standardised functional assay suitable for vaccine evaluation. Current assays, developed over 50 years ago, rely on non-immune human whole blood as a source of neutrophils and complement. Variations in complement and neutrophil activity between donors result in variable data that is difficult to interpret. We have developed an opsonophagocytic killing assay (OPKA) for GAS that utilises dimethylformamide (DMF)-differentiated human promyelocytic leukemia cells (HL-60) as a source of neutrophils and baby rabbit complement, thus removing the major sources of variation in current assays. We have standardised the OPKA for several clinically relevant GAS strain types (emm1, emm6 and emm12) and have shown antibody-specific killing for each emm-type using M-protein specific rabbit antisera. Specificity was demonstrated by pre-incubation of the antisera with homologous M-protein antigens that blocked antibody-specific killing. Additional qualifications of the GAS OPKA, including the assessment of the accuracy, precision, linearity and the lower limit of quantification, were also performed. This GAS OPKA assay has the potential to provide a robust and reproducible platform to accelerate GAS vaccine development. Copyright © 2018 Elsevier Ltd. All rights reserved.

High-Level Fluorescence Labeling of Gram-Positive Pathogens

PubMed Central

Aymanns, Simone; Mauerer, Stefanie; van Zandbergen, Ger; Wolz, Christiane; Spellerberg, Barbara

2011-01-01

Fluorescence labeling of bacterial pathogens has a broad range of interesting applications including the observation of living bacteria within host cells. We constructed a novel vector based on the E. coli streptococcal shuttle plasmid pAT28 that can propagate in numerous bacterial species from different genera. The plasmid harbors a promoterless copy of the green fluorescent variant gene egfp under the control of the CAMP-factor gene (cfb) promoter of Streptococcus agalactiae and was designated pBSU101. Upon transfer of the plasmid into streptococci, the bacteria show a distinct and easily detectable fluorescence using a standard fluorescence microscope and quantification by FACS-analysis demonstrated values that were 10–50 times increased over the respective controls. To assess the suitability of the construct for high efficiency fluorescence labeling in different gram-positive pathogens, numerous species were transformed. We successfully labeled Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus dysgalactiae subsp. equisimilis, Enterococcus faecalis, Enterococcus faecium, Streptococcus mutans, Streptococcus anginosus and Staphylococcus aureus strains utilizing the EGFP reporter plasmid pBSU101. In all of these species the presence of the cfb promoter construct resulted in high-level EGFP expression that could be further increased by growing the streptococcal and enterococcal cultures under high oxygen conditions through continuous aeration. PMID:21731607

Genomic Diversity of Burkholderia pseudomallei Clinical Isolates: Subtractive Hybridization Reveals a Burkholderia mallei-Specific Propage in B. pseudomallei 1026b

DTIC Science & Technology

2004-06-01

identification of several new virulence gene candidates. In particular, K96243 harbors multiple genomic islands with relatively low GC contents, suggesting...coli, Streptococcus pyogenes, Staphylococcus aureus, S. enterica, and Xylella fastidiosa (11, 16, 17). The genomic sequencing results for multiple... virulence genes by subtractive hybridization: identifica- tion of capsular polysaccharide of Burkholderia pseudomallei as a major virulence determinant

The effect of selective photosuppression of sensitized pathogenic microflora: Part II. Experimental validation on animals

NASA Astrophysics Data System (ADS)

Masychev, Viktor I.; Risovannaya, Olga N.

2005-03-01

Results of in vivo experiments have shown the maximum effectiveness of combined use of photo sensitizer 0,1% gel Radachlorine simultaneously with continuous and super pulse low energy irradiation of the diode laser with energy density 400 J/cm2, and power 1W. Given parameters have lead to complete elimination of Streptococcus pyogenes from inflammation foci in oral cavity of experimental animals.

Detection of Staphylococcus Aureus Enterotoxin A and B Genes with PCR-EIA and a Hand-Held Electrochemical Sensor

DTIC Science & Technology

2004-06-11

Streptococcus pneumoniae 33400 Enterobacter cloaceae 49141 S. pyogenes 19615 E. aerogenes m10822 Vibrio cholerae N16961 Enterococcus durans 6056 Yersinia...identified. Thus the sensitivity for both assays was 100%. Of the 56 samples that lacked sea or seb genes, two false positives ( Enterobacter aerogenes ...Comanonas, Enterobacter , Enterococcus, Escherichia, Francisella, Haemophilus, Klebsiella, Listeria, Moraxella, Neisseria, Proteus, Pseudomonas, Salmonella

Streptococcal toxic shock syndrome by an iMLS resistant M type 77 Streptococcus pyogenes in the Netherlands.

PubMed

Gooskens, J; Neeling, A J De; Willems, R J; Wout, J W Van 't; Kuijper, E J

2005-01-01

An increasing number of group A streptococci (GAS) with constitutive or inducible resistance to macrolide-lincosamide-streptogramin B antibiotics (cMLS or iMLS phenotype) is observed in Europe, but MLS resistant GAS associated with streptococcal toxic shock syndrome (STSS) has not been reported. We describe a patient admitted with STSS caused by an iMLS resistant T28 M77 Streptococcus pyogenes carrying the ermA [subclass TR] gene. A 2-y retrospective analysis among 701 nationwide collected GAS strains revealed an incidence of 3.1% of this M type 77 GAS. Analysis of 17 available M77 strains (12 T28 and 5 T13) indicated that 2 (12%) were MLS resistant due to the ermA [TR] gene. Both MLS resistant strains were cultured from blood and belonged to T28 serotype. Multilocus sequence typing (MLST) showed that all M77 isolates belonged to sequence type 63. We conclude that 17 M77 GAS collected in the Netherlands in a 2-y period were associated with invasive disease and belonged to the same clonal complex. Since only 12% carried the ermA [TR] resistance gene, it is very likely that the gene has been acquired by horizontal transmission rather than from spread of a resistant circulating clone.

Auranofin-loaded nanoparticles as a new therapeutic tool to fight streptococcal infections.

PubMed

Díez-Martínez, Roberto; García-Fernández, Esther; Manzano, Miguel; Martínez, Ángel; Domenech, Mirian; Vallet-Regí, María; García, Pedro

2016-01-18

Drug-loaded nanoparticles (NPs) can improve infection treatment by ensuring drug concentration at the right place within the therapeutic window. Poly(lactic-co-glycolic acid) (PLGA) NPs are able to enhance drug localization in target site and to sustainably release the entrapped molecule, reducing the secondary effects caused by systemic antibiotic administration. We have loaded auranofin, a gold compound traditionally used for treatment of rheumatoid arthritis, into PLGA NPs and their efficiency as antibacterial agent against two Gram-positive pathogens, Streptococcus pneumoniae and Streptococcus pyogenes was evaluated. Auranofin-PLGA NPs showed a strong bactericidal effect as cultures of multiresistant pneumococcal strains were practically sterilized after 6 h of treatment with such auranofin-NPs at 0.25 μM. Moreover, this potent bactericidal effect was also observed in S. pneumoniae and S. pyogenes biofilms, where the same concentration of auranofin-NPs was capable of decreasing the bacterial population about 4 logs more than free auranofin. These results were validated using a zebrafish embryo model demonstrating that treatment with auranofin loaded into NPs achieved a noticeable survival against pneumococcal infections. All these approaches displayed a clear superiority of loaded auranofin PLGA nanocarriers compared to free administration of the drug, which supports their potential application for the treatment of streptococcal infections.

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

PubMed

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.

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

PubMed

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.

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

PubMed

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

2016-04-01

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

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

PubMed

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.

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

PubMed

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

2000-02-29

Pathogenic bacteria secrete protein toxins that weaken or disable their host, and thereby act as virulence factors. We have determined the crystal structure of streptococcal pyrogenic exotoxin B (SpeB), a cysteine protease that is a major virulence factor of the human pathogen Streptococcus pyogenes and participates in invasive disease episodes, including necrotizing fasciitis. The structure, determined for the 40-kDa precursor form of SpeB at 1.6-A resolution, reveals that the protein is a distant homologue of the papain superfamily that includes the mammalian cathepsins B, K, L, and S. Despite negligible sequence identity, the protease portion has the canonical papain fold, albeit with major loop insertions and deletions. The catalytic site differs from most other cysteine proteases in that it lacks the Asn residue of the Cys-His-Asn triad. The prosegment has a unique fold and inactivation mechanism that involves displacement of the catalytically essential His residue by a loop inserted into the active site. The structure also reveals the surface location of an integrin-binding Arg-Gly-Asp (RGD) motif that is a feature unique to SpeB among cysteine proteases and is linked to the pathogenesis of the most invasive strains of S. pyogenes.

Generation of efficient mutants of endoglycosidase from Streptococcus pyogenes and their application in a novel one-pot transglycosylation reaction for antibody modification

PubMed Central

Sekiguchi, Yukiko; Nakamura, Kensuke; Kawaguchi, Yoshirou; Honda, Takeshi; Hasegawa, Jun

2018-01-01

The fine structures of Fc N-glycan modulate the biological functions and physicochemical properties of antibodies. By remodeling N-glycan to obtain a homogeneous glycoform or chemically modified glycan, antibody characteristics can be controlled or modified. Such remodeling can be achieved by transglycosylation reactions using a mutant of endoglycosidase from Streptococcus pyogenes (Endo-S) and glycan oxazoline. In this study, we generated improved mutants of Endo-S by introducing additional mutations to the D233Q mutant. Notably, Endo-S D233Q/Q303L, D233Q/E350Q, and several other mutations resulted in transglycosylation efficiencies exceeding 90%, with a single-digit donor-to-substrate ratio of five, and D233Q/Y402F/D405A and several other mutations resulted in slightly reduced transglycosylation efficiencies accompanied by no detectable hydrolysis activity for 48 h. We further demonstrated that the combined use of mutants of Endo-S with Endo-M or Endo-CC, endoglycosidases from Mucor hiemalis and Coprinopsis cinerea, enables one-pot transglycosylation from sialoglycopeptide to antibodies. This novel reaction enables glycosylation remodeling of antibodies, without the chemical synthesis of oxazoline in advance or in situ. PMID:29474426

Deciphering the mode of action of cell wall-inhibiting antibiotics using metabolic labeling of growing peptidoglycan in Streptococcus pyogenes.

PubMed

Sugimoto, Atsushi; Maeda, Asuka; Itto, Kaori; Arimoto, Hirokazu

2017-04-25

Because of the scanty pipeline of antibiotics newly obtained from nature, chemical modification of established drugs is one of the major streams of current antibacterial research. Intuitive and easy-to-use assays are critical for identifying drug candidates with novel modes of action. In this study, we demonstrated that metabolic fluorescent staining of growing cell walls is a powerful tool for mode-of-action analyses of antibiotics using Streptococcus pyogenes. A set of major cell-wall-inhibiting antibiotics (bacitracin, D-cycloserine, flavomycin, oxacillin, ramoplanin, and vancomycin) was employed to validate the potential of the assay. The mechanistic differences of these antibiotics were successfully observed. For instance, D-cycloserine treatment induced fluorescently stained, excessive peripheral cell wall growth. This may indicate that the switch from the peripheral growth stage to the succeeding septal growth was disturbed by the treatment. We then applied this assay to analyze a series of vancomycin derivatives. The assay was sufficiently sensitive to detect the effects of single-site chemical modification of vancomycin on its modes of action. This metabolic fluorescent labeling method is easy to perform, especially because it does not require radiolabeled substrates. Thus, it is suitable for the preliminary evaluation of antibacterial mechanisms during antibacterial research.

Synthesis and SARs of novel lincomycin derivatives Part 5: optimization of lincomycin analogs exhibiting potent antibacterial activities by chemical modification at the 6- and 7-positions.

PubMed

Wakiyama, Yoshinari; Kumura, Ko; Umemura, Eijiro; Masaki, Satomi; Ueda, Kazutaka; Sato, Yasuo; Hirai, Yoko; Hayashi, Yoshio; Ajito, Keiichi

2018-02-01

In order to modify lincomycin at the C-6 and C-7 positions, we prepared target molecules, which have substituted pipecolinic acid at the 6-amino group and a para-substituted phenylthio group at the C-7 position, in application of palladium-catalyzed cross-coupling as a key reaction. As the result of structure-activity relationship (SAR) studies at the 6-position, analogs possessing 4'-cis-(cyclopropylmethyl)piperidine showed significantly strong antibacterial activities against Streptococcus pneumoniae and Streptococcus pyogenes with an erm gene. On the basis of SAR, we further synthesized novel analogs possessing 4'-cis-(cyclopropylmethyl)piperidine by transformation of a C-7 substituent. Consequently, novel derivatives possessing a para-heteroaromatic-phenylthio group at the C-7 position exhibited significantly strong activities against S. pneumoniae and S. pyogenes with an erm gene even when compared with those of telithromycin. Finally, in vivo efficacy of selected two derivatives was evaluated in a rat pulmonary infection model with resistant S. pneumoniae with erm + mef genes. One of them exhibited strong and constant in vivo efficacy in this model, and both compounds showed strong in vivo efficacy against resistant S. pneumoniae with a mef gene.

PIMMS (Pragmatic Insertional Mutation Mapping System) Laboratory Methodology a Readily Accessible Tool for Identification of Essential Genes in Streptococcus

PubMed Central

Blanchard, Adam M.; Egan, Sharon A.; Emes, Richard D.; Warry, Andrew; Leigh, James A.

2016-01-01

The Pragmatic Insertional Mutation Mapping (PIMMS) laboratory protocol was developed alongside various bioinformatics packages (Blanchard et al., 2015) to enable detection of essential and conditionally essential genes in Streptococcus and related bacteria. This extended the methodology commonly used to locate insertional mutations in individual mutants to the analysis of mutations in populations of bacteria. In Streptococcus uberis, a pyogenic Streptococcus associated with intramammary infection and mastitis in ruminants, the mutagen pGhost9:ISS1 was shown to integrate across the entire genome. Analysis of >80,000 mutations revealed 196 coding sequences, which were not be mutated and a further 67 where mutation only occurred beyond the 90th percentile of the coding sequence. These sequences showed good concordance with sequences within the database of essential genes and typically matched sequences known to be associated with basic cellular functions. Due to the broad utility of this mutagen and the simplicity of the methodology it is anticipated that PIMMS will be of value to a wide range of laboratories in functional genomic analysis of a wide range of Gram positive bacteria (Streptococcus, Enterococcus, and Lactococcus) of medical, veterinary, and industrial significance. PMID:27826289

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

PubMed Central

2009-01-01

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. PMID:19486515

Zebrafish and Streptococcal Infections.

PubMed

Saralahti, A; Rämet, M

2015-09-01

Streptococcal bacteria are a versatile group of gram-positive bacteria capable of infecting several host organisms, including humans and fish. Streptococcal species are common colonizers of the human respiratory and gastrointestinal tract, but they also cause some of the most common life-threatening, invasive infections in humans and aquaculture. With its unique characteristics and efficient tools for genetic and imaging applications, the zebrafish (Danio rerio) has emerged as a powerful vertebrate model for infectious diseases. Several zebrafish models introduced so far have shown that zebrafish are suitable models for both zoonotic and human-specific infections. Recently, several zebrafish models mimicking human streptococcal infections have also been developed. These models show great potential in providing novel information about the pathogenic mechanisms and host responses associated with human streptococcal infections. Here, we review the zebrafish infection models for the most relevant streptococcal species: the human-specific Streptococcus pneumoniae and Streptococcus pyogenes, and the zoonotic Streptococcus iniae and Streptococcus agalactiae. The recent success and the future potential of these models for the study of host-pathogen interactions in streptococcal infections are also discussed. © 2015 The Foundation for the Scandinavian Journal of Immunology.

Streptococcal M protein promotes IL-10 production by cGAS-independent activation of the STING signaling pathway

PubMed Central

Movert, Elin; Lienard, Julia; Valfridsson, Christine; Johansson-Lindbom, Bengt

2018-01-01

From an evolutionary point of view a pathogen might benefit from regulating the inflammatory response, both in order to facilitate establishment of colonization and to avoid life-threatening host manifestations, such as septic shock. In agreement with this notion Streptococcus pyogenes exploits type I IFN-signaling to limit detrimental inflammation in infected mice, but the host-pathogen interactions and mechanisms responsible for induction of the type I IFN response have remained unknown. Here we used a macrophage infection model and report that S. pyogenes induces anti-inflammatory IL-10 in an M protein-dependent manner, a function that was mapped to the B- and C-repeat regions of the M5 protein. Intriguingly, IL-10 was produced downstream of type I IFN-signaling, and production of type I IFN occurred via M protein-dependent activation of the STING signaling pathway. Activation of STING was independent of the cytosolic double stranded DNA sensor cGAS, and infection did not induce detectable release into the cytosol of either mitochondrial, nuclear or bacterial DNA–indicating DNA-independent activation of the STING pathway in S. pyogenes infected macrophages. These findings provide mechanistic insight concerning how S. pyogenes induces the type I IFN response and identify a previously unrecognized macrophage-modulating role for the streptococcal M protein that may contribute to curb the inflammatory response to infection. PMID:29579113

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

PubMed

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 amount of tissue damage, balancing between too little damage, which will result in its elimination, and too much damage, which will debilitate the host. Here we identify components of a genetic circuit involved in stress resistance and toxin expression that has a fine-tuning function in tissue damage. The circuit consists of two versions of the protein SpxA that regulate transcription and are highly similar but have opposing effects on the severity of soft tissue damage. These results will help us understand how virulence is fine-tuned in other pathogens that have two SpxA proteins. Copyright © 2017 Port et al.

Dynamic distribution of the SecA and SecY translocase subunits and septal localization of the HtrA surface chaperone/protease during Streptococcus pneumoniae D39 cell division.

PubMed

Tsui, Ho-Ching Tiffany; Keen, Susan K; Sham, Lok-To; Wayne, Kyle J; Winkler, Malcolm E

2011-01-01

The Sec translocase pathway is the major route for protein transport across and into the cytoplasmic membrane of bacteria. Previous studies reported that the SecA translocase ATP-binding subunit and the cell surface HtrA protease/chaperone formed a single microdomain, termed "ExPortal," in some species of ellipsoidal (ovococcus) Gram-positive bacteria, including Streptococcus pyogenes. To investigate the generality of microdomain formation, we determined the distribution of SecA and SecY by immunofluorescent microscopy in Streptococcus pneumoniae (pneumococcus), which is an ovococcus species evolutionarily distant from S. pyogenes. In the majority (≥ 75%) of exponentially growing cells, S. pneumoniae SecA (SecA (Spn)) and SecY (Spn) located dynamically in cells at different stages of division. In early divisional cells, both Sec subunits concentrated at equators, which are future sites of constriction. Further along in division, SecA(Spn) and SecY(Spn) remained localized at mid-cell septa. In late divisional cells, both Sec subunits were hemispherically distributed in the regions between septa and the future equators of dividing cells. In contrast, the HtrA (Spn) homologue localized to the equators and septa of most (> 90%) dividing cells, whereas the SrtA(Spn) sortase located over the surface of cells in no discernable pattern. This dynamic pattern of Sec distribution was not perturbed by the absence of flotillin family proteins, but was largely absent in most cells in early stationary phase and in cls mutants lacking cardiolipin synthase. These results do not support the existence of an ExPortal microdomain in S. pneumoniae. Instead, the localization of the pneumococcal Sec translocase depends on the stage of cell division and anionic phospholipid content. Two patterns of Sec translocase distribution, an ExPortal microdomain in certain ovococcus-shaped species like Streptococcus pyogenes and a spiral pattern in rod-shaped species like Bacillus subtilis, have been reported for Gram-positive bacteria. This study provides evidence for a third pattern of Sec localization in the ovococcus human pathogen Streptococcus pneumoniae. The SecA motor and SecY channel subunits of the Sec translocase localize dynamically to different places in the mid-cell region during the division cycle of exponentially growing, but not stationary-phase, S. pneumoniae. Unexpectedly, the S. pneumoniae HtrA (HtrA(Spn)) protease/chaperone principally localizes to cell equators and division septa. The coincident localization of SecA(Spn), SecY (Spn), and HtrA (Spn) to regions of peptidoglycan (PG) biosynthesis in unstressed, growing cells suggests that the pneumococcal Sec translocase directs assembly of the PG biosynthesis apparatus to regions where it is needed during division and that HtrA(Spn) may play a general role in quality control of proteins exported by the Sec translocase.

University of California San Francisco (UCSF-1): Construction of Directional Regulatory Networks Using Orthogonal CRISPR/Cas Screens | Office of Cancer Genomics

Cancer.gov

UCSF investigators developed an orthogonal CRISPR/Cas system which can be used to quantify gene regulation and construct directional regulatory networks. They combined two orthogonal Cas9 proteins from Streptococcus pyogenes and Staphylococcus aureus to carry out a dual screen in which one gene is activated while a second gene is deleted in the same cell. Read the abstract.

Modification of the classical Lancefield assay of group A streptococcal killing to reduce inter-donor variation.

PubMed

Reglinski, Mark; Lynskey, Nicola N; Sriskandan, Shiranee

2016-05-01

The lack of a surrogate-of-immunity assay presents a major barrier to Streptococcus pyogenes research. Modification of the Lancefield assay to include an antibody digestion step reduced inter-donor variation and permitted detection of the anti-streptococcal activity of intravenous immunoglobulin and convalescent serum, thus facilitating retrospective evaluation of immunity using stored samples. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Distribution of macrolide resistance mechanisms in Bulgarian clinical isolates of Streptococcus pyogenes during the years of 2013-2016.

PubMed

Muhtarova, Adile A; Gergova, Raina T; Mitov, Ivan G

2017-09-01

Streptococcus pyogenes, or group A streptococcus (GAS), is the main etiological agent of bacterial tonsillopharyngitis and a common cause of a wide variety of other mild to severe infections. Objectives of the present study was to determine and evaluate the distribution of genetic mechanisms associated with certain phenotypes of macrolide resistance in Bulgarian GAS isolated during the years of 2013-2016. All GAS strains were screened for the macrolide resistance genes erm(A), erm(B) and mef(A), using multiplex polymerase chain reaction (PCR). The minimal inhibitory concentrations (MICs) of erythromycin, azithromycin, clarithromycin, clindamycin were determined by E-tests. Almost 23% of GAS isolates obtained in 2013-2014 and near 40% of them in 2015-2016 contained various elements of resistance. The predominant gene was mef(A), which encodes an efflux pump (M-phenotype), identified in 57.84% of the macrolide-resistant strains. The next frequently prevalent mechanism was a combination of mef(A) and erm(B) in 22.55%, which determined high-level inducible or constitutive resistance to macrolides, lincosamides and streptogramins (iMLSB or cMLSB). The highest MIC value (>256mg/L) was detected in association with erm(B) (p<0.05). The MIC range was observed to be much higher in the isolates with combinations of resistance genes vs. those with mef genes alone (p<0.05). The data about the distribution and prevalence of macrolide resistance mechanisms obtained in this study can help in the treatment of persistent and recurrent GAS infections and in the correct choice of empiric therapy. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Different Genetic Elements Carrying the tet(W) Gene in Two Human Clinical Isolates of Streptococcus suis▿ †

PubMed Central

Palmieri, Claudio; Princivalli, Maria Stella; Brenciani, Andrea; Varaldo, Pietro E.; Facinelli, Bruna

2011-01-01

The genetic support for tet(W), an emerging tetracycline resistance determinant, was studied in two strains of Streptococcus suis, SsCA and SsUD, both isolated in Italy from patients with meningitis. Two completely different tet(W)-carrying genetic elements, sharing only a tet(W)-containing segment barely larger than the gene, were found in the two strains. The one from strain SsCA was nontransferable, and aside from an erm(B)-containing insertion, it closely resembled a genomic island recently described in an S. suis Chinese human isolate in sequence, organization, and chromosomal location. The tet(W)-carrying genetic element from strain SsUD was transferable (at a low frequency) and, though apparently noninducible following mitomycin C treatment, displayed a typical phage organization and was named ΦSsUD.1. Its full sequence was determined (60,711 bp), the highest BLASTN score being Streptococcus pyogenes Φm46.1. ΦSsUD.1 exhibited a unique combination of antibiotic and heavy metal resistance genes. Besides tet(W), it contained a MAS (macrolide-aminoglycoside-streptothricin) fragment with an erm(B) gene having a deleted leader peptide and a cadC/cadA cadmium efflux cassette. The MAS fragment closely resembled the one recently described in pneumococcal transposons Tn6003 and Tn1545. These resistance genes found in the ΦSsUD.1 phage scaffold differed from, but were in the same position as, cargo genes carried by other streptococcal phages. The chromosome integration site of ΦSsUD.1 was at the 3′ end of a conserved tRNA uracil methyltransferase (rum) gene. This site, known to be an insertional hot spot for mobile elements in S. pyogenes, might play a similar role in S. suis. PMID:21115784

Different genetic elements carrying the tet(W) gene in two human clinical isolates of Streptococcus suis.

PubMed

Palmieri, Claudio; Princivalli, Maria Stella; Brenciani, Andrea; Varaldo, Pietro E; Facinelli, Bruna

2011-02-01

The genetic support for tet(W), an emerging tetracycline resistance determinant, was studied in two strains of Streptococcus suis, SsCA and SsUD, both isolated in Italy from patients with meningitis. Two completely different tet(W)-carrying genetic elements, sharing only a tet(W)-containing segment barely larger than the gene, were found in the two strains. The one from strain SsCA was nontransferable, and aside from an erm(B)-containing insertion, it closely resembled a genomic island recently described in an S. suis Chinese human isolate in sequence, organization, and chromosomal location. The tet(W)-carrying genetic element from strain SsUD was transferable (at a low frequency) and, though apparently noninducible following mitomycin C treatment, displayed a typical phage organization and was named ΦSsUD.1. Its full sequence was determined (60,711 bp), the highest BLASTN score being Streptococcus pyogenes Φm46.1. ΦSsUD.1 exhibited a unique combination of antibiotic and heavy metal resistance genes. Besides tet(W), it contained a MAS (macrolide-aminoglycoside-streptothricin) fragment with an erm(B) gene having a deleted leader peptide and a cadC/cadA cadmium efflux cassette. The MAS fragment closely resembled the one recently described in pneumococcal transposons Tn6003 and Tn1545. These resistance genes found in the ΦSsUD.1 phage scaffold differed from, but were in the same position as, cargo genes carried by other streptococcal phages. The chromosome integration site of ΦSsUD.1 was at the 3' end of a conserved tRNA uracil methyltransferase (rum) gene. This site, known to be an insertional hot spot for mobile elements in S. pyogenes, might play a similar role in S. suis.

The association between varicella (chickenpox) and group A streptococcus infections in historical perspective

PubMed Central

Coleman, Stephen

2016-01-01

Objectives: The aim of the research is to investigate the historical relationship between varicella and Streptococcus pyogenes infections. In the past few decades, varicella has been identified as a risk factor for invasive group A streptococcus infections. The question is whether this relationship also existed between varicella and scarlet fever in the historical era. Methods: The analysis begins with a search of historical medical reports on the relationship between varicella and scarlet fever epidemics in the late 19th and early 20th century, as well as in more recent empirical studies. Correlations and cross-correlations between varicella and scarlet fever are analyzed using weekly public health case reports from 1924 to 1932 for Boston, Chicago, New York City, and Philadelphia. Regression models are used to estimate the relationship between varicella and scarlet fever after controlling for seasonal forcing. Results: Historical records give limited support for a causal relationship between varicella and scarlet fever but indicate that these diseases often occurred close in time to each other. Likewise, statistical analysis shows that varicella and scarlet fever epidemics are closely aligned with each other, and varicella has a strong relationship with scarlet fever. The relationship is stronger than reported in any previous research on the two diseases. Conclusion: The close correspondence of the two diseases likely depends on multiple factors, including seasonal forcing, a causal relationship, and co-infections. The results raise questions about whether this close relationship might have had a synergistic effect or a role in the evolution of S. pyogenes from the virulent, high incidence epidemics of the 19th century to the relatively benign scarlet fever of the 1950s. PMID:27504182

Antimicrobial activities of some Thai traditional medical longevity formulations from plants and antibacterial compounds from Ficus foveolata.

PubMed

Meerungrueang, W; Panichayupakaranant, P

2014-09-01

Medicinal plants involved in traditional Thai longevity formulations are potential sources of antimicrobial compounds. To evaluate the antimicrobial activities of some extracts from medicinal plants used in traditional Thai longevity formulations against some oral pathogens, including Streptococcus pyogenes, Streptococcus mitis, Streptococcus mutans, and Candida albicans. An extract that possessed the strongest antimicrobial activity was fractionated to isolate and identify the active compounds. Methanol and ethyl acetate extracts of 25 medicinal plants used as Thai longevity formulations were evaluated for their antimicrobial activity using disc diffusion (5 mg/disc) and broth microdilution (1.2-2500 µg/mL) methods. The ethyl acetate extract of Ficus foveolata Wall. (Moraceae) stems that exhibited the strongest antibacterial activity was fractionated to isolate the active compounds by an antibacterial assay-guided isolation process. The ethyl acetate extract of F. foveolata showed the strongest antibacterial activity with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 19.5-39.0 and 39.0-156.2 µg/mL, respectively. On the basis of an antibacterial assay-guided isolation, seven antibacterial compounds, including 2,6-dimethoxy-1,4-benzoquinone (1), syringaldehyde (2), sinapaldehyde (3), coniferaldehyde (4), 3β-hydroxystigmast-5-en-7-one (5), umbelliferone (6), and scopoletin (7), were purified. Among these isolated compounds, 2,6-dimethoxy-1,4-benzoquinone (1) exhibited the strongest antibacterial activities against S. pyogenes, S. mitis, and S. mutans with MIC values of 7.8, 7.8, and 15.6 µg/mL, and MBC values of 7.8, 7.8, and 31.2 µg/mL, respectively. In addition, this is the first report of these antibacterial compounds in the stems of F. foveolata.

Differential diagnosis between tuberculous spondylodiscitis and pyogenic spontaneous spondylodiscitis: a multicenter descriptive and comparative study.

PubMed

Yoon, Young K; Jo, Yu M; Kwon, Hyun H; Yoon, Hee J; Lee, Eun J; Park, So Y; Park, Seong Y; Choo, Eun J; Ryu, Seong Y; Lee, Mi S; Yang, Kyung S; Kim, Shin W

2015-08-01

Although tuberculous and pyogenic spondylodiscitis are common causes of spinal infections, their protean manifestation complicates differential diagnosis. The clinical, laboratory, and radiologic characteristics of tuberculous and pyogenic spontaneous spondylodiscitis were compared in this study. This multicenter retrospective study was conducted in 11 teaching hospitals in the Republic of Korea from January 2011 to December 2013. Study subjects included adult patients (≥18 years) diagnosed with tuberculous (n=60) or pyogenic (n=117) spontaneous spondylodiscitis. Risk factors for tuberculous spondylodiscitis were determined, and their predictive performance was evaluated. Multivariate logistic regression analysis was performed to determine predictors independently associated with tuberculous spondylodiscitis. Receiver-operating characteristic curve analysis using the presence or absence of risk factors was used to generate a risk index to identify patients with increased probability of tuberculous spondylodiscitis. Of 177 patients, multivariate logistic regression analysis showed that patients with tuberculous spondylodiscitis (n=60) were more frequently women, with increased nonlumbar spinal involvement and associated non-spinal lesions, delayed diagnosis, higher serum albumin levels, reduced white blood cell counts, and lower C-reactive protein and procalcitonin levels. Among 117 patients with pyogenic spondylodiscitis, the most frequent causative microorganism was Staphylococcus aureus (64.1%). The mean diagnostic delay was significantly shorter, which may reflect higher clinical expression leading to earlier diagnosis. A combination of clinical data and biomarkers had better predictive value for differential diagnosis compared with biomarkers alone, with an area under the curve of 0.93, and sensitivity, specificity, and positive and negative predictive values of 95.0%, 79.5%, 70.4%, and 96.9%, respectively. This study provides guidance for clinicians to predict the causative organisms of spondylodiscitis in uncertain situations and before culture or pathologic examinations. Clinical data and single biomarkers combined can be useful for differential diagnoses between tuberculous and pyogenic spondylodiscitis. Copyright © 2015. Published by Elsevier Inc.

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

PubMed

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

2014-01-01

Pyogenic granuloma is defined as a benign neoplasm of vascular phenotype. This case describes the clinical and histopathological features of a gigantic mucogingival pyogenic granuloma, in a 14-year-old healthy black boy. This exophytic gray-purple mass, related to a toothpick injury, had more than twelve-month evolution on the anterior mandible involving lingual area besides to the floor of the mouth pressing the right salivary duct. Conservative excision was performed, followed by uncomplicated healing with no recurrence in two years. The histopathological examination reported a pyogenic granuloma (lobular capillary haemangioma). The authors provide a discussion of the presurgical differential diagnosis of the lesion. This case report presents an extremely uncommon location of a gigantic pyogenic granuloma, involving mucogingival complex and affecting the salivary outflow. This clinical manuscript may shed light on the controversies about possible mechanisms inducing oral pyogenic granuloma.

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

PubMed Central

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

2014-01-01

Pyogenic granuloma is defined as a benign neoplasm of vascular phenotype. This case describes the clinical and histopathological features of a gigantic mucogingival pyogenic granuloma, in a 14-year-old healthy black boy. This exophytic gray-purple mass, related to a toothpick injury, had more than twelve-month evolution on the anterior mandible involving lingual area besides to the floor of the mouth pressing the right salivary duct. Conservative excision was performed, followed by uncomplicated healing with no recurrence in two years. The histopathological examination reported a pyogenic granuloma (lobular capillary haemangioma). The authors provide a discussion of the presurgical differential diagnosis of the lesion. This case report presents an extremely uncommon location of a gigantic pyogenic granuloma, involving mucogingival complex and affecting the salivary outflow. This clinical manuscript may shed light on the controversies about possible mechanisms inducing oral pyogenic granuloma. PMID:24987485

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

PubMed

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

2005-02-01

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

Mechanisms of group A Streptococcus resistance to reactive oxygen species

PubMed Central

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

2015-01-01

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

Mechanisms of group A Streptococcus resistance to reactive oxygen species.

PubMed

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

2015-07-01

Streptococcus pyogenes, also known as group A Streptococcus (GAS), is an exclusively human Gram-positive bacterial pathogen ranked among the 'top 10' causes of infection-related deaths worldwide. GAS commonly causes benign and self-limiting epithelial infections (pharyngitis and impetigo), and less frequent severe invasive diseases (bacteremia, toxic shock syndrome and necrotizing fasciitis). Annually, GAS causes 700 million infections, including 1.8 million invasive infections with a mortality rate of 25%. In order to establish an infection, GAS must counteract the oxidative stress conditions generated by the release of reactive oxygen species (ROS) at the infection site by host immune cells such as neutrophils and monocytes. ROS are the highly reactive and toxic byproducts of oxygen metabolism, including hydrogen peroxide (H2O2), superoxide anion (O2•(-)), hydroxyl radicals (OH•) and singlet oxygen (O2*), which can damage bacterial nucleic acids, proteins and cell membranes. This review summarizes the enzymatic and regulatory mechanisms utilized by GAS to thwart ROS and survive under conditions of oxidative stress. © FEMS 2015.

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

PubMed

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).

Prophagic DNA Fragments in Streptococcus agalactiae Strains and Association with Neonatal Meningitis

PubMed Central

van der Mee-Marquet, Nathalie; Domelier, Anne-Sophie; Mereghetti, Laurent; Lanotte, Philippe; Rosenau, Agnès; van Leeuwen, Willem; Quentin, Roland

2006-01-01

We identified—by randomly amplified polymorphic DNA (RAPD) analysis at the population level followed by DNA differential display, cloning, and sequencing—three prophage DNA fragments (F5, F7, and F10) in Streptococcus agalactiae that displayed significant sequence similarity to the DNA of S. agalactiae and Streptococcus pyogenes. The F5 sequence aligned with a prophagic gene encoding the large subunit of a terminase, F7 aligned with a phage-associated cell wall hydrolase and a phage-associated lysin, and F10 aligned with a transcriptional regulator (ArpU family) and a phage-associated endonuclease. We first determined the prevalence of F5, F7, and F10 by PCR in a collection of 109 strains isolated in the 1980s and divided into two populations: one with a high risk of causing meningitis (HR group) and the other with a lower risk of causing meningitis (LR group). These fragments were significantly more prevalent in the HR group than in the LR group (P < 0.001). Our findings suggest that lysogeny has increased the ability of some S. agalactiae strains to invade the neonatal brain endothelium. We then determined the prevalence of F5, F7, and F10 by PCR in a collection of 40 strains recently isolated from neonatal meningitis cases for comparison with the cerebrospinal fluid (CSF) strains isolated in the 1980s. The prevalence of the three prophage DNA fragments was similar in these two populations isolated 15 years apart. We suggest that the prophage DNA fragments identified have remained stable in many CSF S. agalactiae strains, possibly due to their importance in virulence or fitness. PMID:16517893

Assessing the impact of a temporary class drug order on ethylphenidate-related infections among people who inject drugs in Lothian, Scotland: an interrupted time-series analysis.

PubMed

Yeung, Alan; Weir, Amanda; Austin, Hannah; Morrison, Kirsty; Inverarity, Donald; Sherval, Jim; Henderson, Naomi; Joshi, Shruti; Ure, Roisin; McAuley, Andrew

2017-10-01

In April 2015, the UK government enacted a temporary class drug order (TCDO) on ethylphenidate in response to reported harms associated with its use, in particular an outbreak of infections among people who inject drugs (PWID) in Lothian, Scotland. This study assesses the effect that the TCDO had on reducing the most common infections identified during the outbreak: Streptococcus pyogenes and Staphylococcus aureus. The outbreak was split into a pre-intervention period (35 weeks) and a post-intervention period (26 weeks) based around the date of the TCDO. Segmented negative binomial regression models were used to compare trends in weekly counts of infections between the pre- and post-intervention periods. PWID in the Lothian region of Scotland. Cases of S. pyogenes and S. aureus infections reported within the National Health Service, Lothian. There were 251 S. pyogenes and/or S. aureus infections recorded among 211 PWID between February 2014 and December 2015: 171 infections in the pre-intervention period and 51 in the post-intervention period. Significant trend changes in weekly S. pyogenes and/or S. aureus infections following the TCDO were found [relative risk (RR) = 0.88, 95% confidence interval (CI) = 0.82-0.94]. PWID who self-reported using novel psychoactive substances (NPS) were at higher risk of acquiring these infections (RR = 1.81, 95% CI = 1.12-2.93), particularly when comparing the risk of infection with NPS use for a specific strain, S. pyogenes emm76.0, against the risk of infection with NPS use for S. pyogenes (emm types other than emm76.0) (RR = 3.49, 95% CI = 1.32-9.21). The UK government's 2015 temporary class drug order on ethylphenidate was effective in reducing infections among people who inject drugs during an outbreak situation in Lothian, Scotland. © 2017 Crown copyright.

Targeted Proteomics and Absolute Protein Quantification for the Construction of a Stoichiometric Host-Pathogen Surface Density Model.

PubMed

Sjöholm, Kristoffer; Kilsgård, Ola; Teleman, Johan; Happonen, Lotta; Malmström, Lars; Malmström, Johan

2017-04-01

Sepsis is a systemic immune response responsible for considerable morbidity and mortality. Molecular modeling of host-pathogen interactions in the disease state represents a promising strategy to define molecular events of importance for the transition from superficial to invasive infectious diseases. Here we used the Gram-positive bacterium Streptococcus pyogenes as a model system to establish a mass spectrometry based workflow for the construction of a stoichiometric surface density model between the S. pyogenes surface, the surface virulence factor M-protein, and adhered human blood plasma proteins. The workflow relies on stable isotope labeled reference peptides and selected reaction monitoring mass spectrometry analysis of a wild-type strain and an M-protein deficient mutant strain, to generate absolutely quantified protein stoichiometry ratios between S. pyogenes and interacting plasma proteins. The stoichiometry ratios in combination with a novel targeted mass spectrometry method to measure cell numbers enabled the construction of a stoichiometric surface density model using protein structures available from the protein data bank. The model outlines the topology and density of the host-pathogen protein interaction network on the S. pyogenes bacterial surface, revealing a dense and highly organized protein interaction network. Removal of the M-protein from S. pyogenes introduces a drastic change in the network topology, validated by electron microscopy. We propose that the stoichiometric surface density model of S. pyogenes in human blood plasma represents a scalable framework that can continuously be refined with the emergence of new results. Future integration of new results will improve the understanding of protein-protein interactions and their importance for bacterial virulence. Furthermore, we anticipate that the general properties of the developed workflow will facilitate the production of stoichiometric surface density models for other types of host-pathogen interactions. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

In-vitro effect of edta-tris-lysozyme solutions on selected pathogenic bacteria.

PubMed

Wooley, R E; Blue, J L

1975-02-01

The in-vitro effect of EDTA-Tris-lysozyme solution on 16 pathogenic bacteria of medical or veterinary importance was determined. Marked decreases in bacterial count occurred with Pseudomonas aeruginosa, Escherichia coli, Moraxella osloensis and Campylobacter fetus, and smaller decreses with Salmonella typhimurium, Shigella boydii, Aeromonas hydrophila, proteus mirabilis, Listeria monocytogenes and Erysipelothrix insidiosa. The test solution had no effect on Klebsiella ozaenae, Brucella canis, Cornynebacterium pyogenes, Coryne, renale, Streptococcus equi and staphylococcus aureus.

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

PubMed

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

2016-07-22

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

Antibacterial screening of traditional herbal plants and standard antibiotics against some human bacterial pathogens.

PubMed

Awan, Uzma Azeem; Andleeb, Saiqa; Kiyani, Ayesha; Zafar, Atiya; Shafique, Irsa; Riaz, Nazia; Azhar, Muhammad Tehseen; Uddin, Hafeez

2013-11-01

Chloroformic and isoamyl alcohol extracts of Cinnnamomum zylanicum, Cuminum cyminum, Curcuma long Linn, Trachyspermum ammi and selected standard antibiotics were investigated for their in vitro antibacterial activity against six human bacterial pathogens. The antibacterial activity was evaluated and based on the zone of inhibition using agar disc diffusion method. The tested bacterial strains were Streptococcus pyogenes, Staphylococcus epidermidis, Klebsiella pneumonia, Staphylococcus aurues, Serratia marcesnces, and Pseudomonas aeruginosa. Ciprofloxacin showed highly significant action against K. pneumonia and S. epidermidis while Ampicillin and Amoxicillin indicated lowest antibacterial activity against tested pathogens. Among the plants chloroform and isoamyl alcohol extracts of C. cyminum, S. aromaticum and C. long Linn had significant effect against P. aeruginosa, S. marcesnces and S. pyogenes. Comparison of antibacterial activity of medicinal herbs and standard antibiotics was also recorded via activity index. Used medicinal plants have various phytochemicals which reasonably justify their use as antibacterial agent.

Streptococcal Toxic Shock Syndrome: Life Saving Role of Peritoneal Lavage and Drainage.

PubMed

Yokoyama, Minako; Oyama, Fumie; Ito, Asami; Yokota, Megumi; Matsukura, Daisuke; Tsutsumi, Shinji; Kasai, Tomonori; Nitobe, Yohshiro; Morikawa, Akiko; Ozaki, Takashi; Yokoyama, Yoshihito

2016-01-01

We encountered a case where an infection with group A streptococcus (GAS; ie, Streptococcus pyogenes) initially caused primary peritonitis and then subsequently caused streptococcal toxic shock syndrome. The patient's life was likely saved by an emergency laparotomy followed by extensive peritoneal lavage and drainage. A 40-year-old woman was admitted to the Emergency Department for lower abdominal pain and numbness in the extremities. She presented with systemic inflammatory response syndrome. An emergency laparotomy was performed, and ascites that resembled pus and general peritonitis were noted. Peritoneal lavage and drainage were performed, and GAS was isolated from peritoneal fluid. Gram staining of cervical polyp specimens revealed Gram-positive bacteria. The patient was diagnosed with streptococcal toxic shock syndrome due to an ascending GAS infection originating from vagina.

[The pharmacodynamic research on fuxiye, a Chinese herbal lotion for external wash].

PubMed

Chen, Xue-Qi; Ge, Bei-Fen; Shen, Wei; Liu, Pei; Cao, Jun-Ming; Chen, Zhe

2013-05-01

To observe antisepsis, anti-swelling, and therapeutic effects of Fuxiye (FXY), a Chinese medical lotion for external wash in treating vaginitis model rats. The cervicitis rat model was induced by agar plate diffusion, ear auricle swelling induced by dimethylbenzene, and chemical stimulus. The in vitro antibiotic actions of FXY were observed. Besides, its effects on the swelling and inflammation in model rats were also observed. FXY at 25 mg/mL could completely inhibit the growth of Pseudomonas aeruginosa, Escherichia coli, pyogenic Streptococcus, and Streptococcus agalactiae. FXY at 50 mg/mL could completely inhibit the growth of Staphylococcus aureus and Candida albicans. It obviously restrained dimethylbenzene induced ear auricle swelling. It significantly alleviated cervicitis induced by chemical stiumli. FXY showed better effects on antisepsis, anti-inflammation, and treating cervicitis.

Group B streptococcal necrotizing pneumonia in a diabetic adult patient.

PubMed

Pacha, Andrea; Luna Cian, Ramiro; Bonofiglio, Laura; Solari, Melisa; Strada, Virginia; Suárez, Mariana; Vigliarolo, Laura; Tersigni, Carina; Mollerach, Marta; Lopardo, Horacio

The aim of this report is to describe a rare case of necrotizing pneumonia due to group B Streptococcus serotype III in a relatively young male adult (48 years old) suffering from diabetes. The organism was isolated from his pleural fluid and was only resistant to tetracycline. The patient first received ceftazidime (2g/8h i.v.)+clindamycin (300mg/8h) for 18 days and then he was discharged home and orally treated with amoxicillin clavulanic acid (1g/12h) for 23 days with an uneventful evolution. As in the cases of invasive infection by Streptococcus pyogenes, clindamycin could prevent streptococcal toxic shock syndrome. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

The Naval Health Research Center Respiratory Disease Laboratory.

PubMed

Ryan, M; Gray, G; Hawksworth, A; Malasig, M; Hudspeth, M; Poddar, S

2000-07-01

Concern about emerging and reemerging respiratory pathogens prompted the development of a respiratory disease reference laboratory at the Naval Health Research Center. Professionals working in this laboratory have instituted population-based surveillance for pathogens that affect military trainees and responded to threats of increased respiratory disease among high-risk military groups. Capabilities of this laboratory that are unique within the Department of Defense include adenovirus testing by viral shell culture and microneutralization serotyping, influenza culture and hemagglutination inhibition serotyping, and other special testing for Streptococcus pneumoniae, Streptococcus pyogenes, Mycoplasma pneumonia, and Chlamydia pneumoniae. Projected capabilities of this laboratory include more advanced testing for these pathogens and testing for other emerging pathogens, including Bordetella pertussis, Legionella pneumoniae, and Haemophilus influenzae type B. Such capabilities make the laboratory a valuable resource for military public health.

Pathogenesis of group A streptococcal infections.

PubMed

Henningham, Anna; Barnett, Timothy C; Maamary, Peter G; Walker, Mark J

2012-05-01

Group A Streptococcus (GAS; Streptococcus pyogenes) is a human pathogen which causes significant morbidity and mortality globally. GAS typically infects the throat and skin of the host, causing mild infections such as pharyngitis and impetigo, in addition to life threatening conditions including necrotizing fasciitis, streptococcal toxic shock syndrome (STSS), and bacteremia. Repeated infection with GAS may result in the non-suppurative sequelae, acute rheumatic fever, and acute glomerulonephritis. GAS remains sensitive to the antibiotic penicillin which can be administered as a means to treat infection or as prophylaxis. However, issues with patient compliance and a growing concern over the possible emergence of resistant GAS strains may limit the usefulness of antibiotics in the future. A vaccine capable of preventing GAS infection may be the only effective way to control and eliminate GAS infection and disease.

Human intravenous immunoglobulin for experimental streptococcal toxic shock: bacterial clearance and modulation of inflammation.

PubMed

Sriskandan, Shiranee; Ferguson, Melissa; Elliot, Victoria; Faulkner, Lee; Cohen, Jonathan

2006-07-01

Polyclonal human intravenous immunoglobulin (IVIG) has been advocated as an adjunct to therapy in severe invasive streptococcal toxic shock because of its ability to neutralize superantigen toxins. The aim of this study was to assess IVIG therapeutic efficacy in an experimental model of streptococcal toxic shock. To confirm the in vitro activity of IVIG against the Streptococcus pyogenes strain used in the study, IVIG was tested for superantigen neutralizing and bacterial opsonizing activity prior to in vivo studies. To evaluate the in vivo effects of IVIG in terms of microbiological outcome and disease severity in a superantigen-sensitive transgenic model of streptococcal shock, HLA-DQ transgenic mice were treated with IVIG either at the time of infection or after infection with S. pyogenes. Antibiotics were included in some studies. The IVIG preparation neutralized superantigenicity of S. pyogenes in vitro and enhanced bacterial killing in a whole blood assay. When given to mice at the time of S. pyogenes infection, IVIG neutralized circulating superantigens and reduced systemic inflammatory response. Remarkably, IVIG-enhanced systemic clearance of bacteria and enhanced neutrophil infiltrate into the infected tissues. However, when used in combination with penicillin and clindamycin in a delayed treatment setting, IVIG did not confer additional therapeutic benefit, in terms of inflammatory response, bacterial clearance or survival. IVIG monotherapy can confer benefit in experimental streptococcal shock, but extension of these findings to the clinical situation will require further evaluation.

Endocarditis in adults with bacterial meningitis.

PubMed

Lucas, Marjolein J; Brouwer, Matthijs C; van der Ende, Arie; van de Beek, Diederik

2013-05-21

Endocarditis may precede or complicate bacterial meningitis, but the incidence and impact of endocarditis in bacterial meningitis are unknown. We assessed the incidence and clinical characteristics of patients with meningitis and endocarditis from a nationwide cohort study of adults with community-acquired bacterial meningitis in the Netherlands from 2006 to 2012. Endocarditis was identified in 24 of 1025 episodes (2%) of bacterial meningitis. Cultures yielded Streptococcus pneumoniae in 13 patients, Staphylococcus aureus in 8 patients, and Streptococcus agalactiae, Streptococcus pyogenes, and Streptococcus salivarius in 1 patient each. Clues leading to the diagnosis of endocarditis were cardiac murmurs, persistent or recurrent fever, a history of heart valve disease, and S aureus as the causative pathogen of bacterial meningitis. Treatment consisted of prolonged antibiotic therapy in all patients and surgical valve replacement in 10 patients (42%). Two patients were treated with oral anticoagulants, and both developed life-threatening intracerebral hemorrhage. Systemic (70%) and neurological (54%) complications occurred frequently, leading to a high proportion of patients with unfavorable outcome (63%). Seven of 24 patients (29%) with meningitis and endocarditis died. Endocarditis is an uncommon coexisting condition in bacterial meningitis but is associated with a high rate of unfavorable outcome.

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

PubMed

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

2014-06-01

Clustered regularly interspaced short palindromic repeats (CRISPR) are composed of numerous repeat-spacer units and are considered a prokaryotic defence system against foreign nucleic acids. Since antibiotic-resistant genes are frequently encoded in foreign nucleic acids, the aim of this study was to test whether erythromycin susceptibility in group A streptococcus (Streptococcus pyogenes) is associated with characteristics of CRISPR elements. Erythromycin susceptibility of 330 isolates collected between 1997 and 2003 was analysed. Among 29 emm types, emm12, emm75 and emm92 showed significant changes in erythromycin-resistance rates. By sequencing the spacers from two CRISPR loci, spacer contents in emm12, emm75 and emm92 strains were associated with erythromycin susceptibility. Strains with fewer spacers were more resistant to erythromycin. Moreover, in emm4 strains, which showed no significant change in their annual erythromycin-resistance rate, CRISPR type and number of spacers were not correlated with erythromycin susceptibility. These results highlight a novel association between CRISPR spacer content and erythromycin susceptibility in group A streptococcus. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

Comparative Analysis of the Antibacterial Activity of a Novel Peptide Deformylase Inhibitor, GSK1322322

PubMed Central

O'Dwyer, Karen; Hackel, Meredith; Hightower, Sarah; Hoban, Daryl; Bouchillon, Samuel; Qin, Donghui; Aubart, Kelly; Zalacain, Magdalena

2013-01-01

GSK1322322 is a novel peptide deformylase (PDF) inhibitor being developed for the intravenous and oral treatment of acute bacterial skin and skin structure infections and hospitalized patients with community-acquired pneumonia. The activity of GSK1322322 was tested against a global collection of clinical isolates of Haemophilus influenzae (n = 2,370), Moraxella catarrhalis (n = 115), Streptococcus pneumoniae (n = 947), Streptococcus pyogenes (n = 617), and Staphylococcus aureus (n = 940), including strains resistant to one or more marketed antibiotics. GSK1322322 had an MIC90 of 1 μg/ml against M. catarrhalis and 4 μg/ml against H. influenzae, with 88.8% of β-lactamase-positive strains showing growth inhibition at that concentration. All S. pneumoniae strains were inhibited by ≤4 μg/ml of GSK1322322, with an MIC90 of 2 μg/ml. Pre-existing resistance mechanisms did not affect its potency, as evidenced by the MIC90 of 1 μg/ml for penicillin, levofloxacin, and macrolide-resistant S. pneumoniae. GSK1322322 was very potent against S. pyogenes strains, with an MIC90 of 0.5 μg/ml, irrespective of their macrolide resistance phenotype. This PDF inhibitor was also active against S. aureus strains regardless of their susceptibility to methicillin, macrolides, or levofloxacin, with an MIC90 of 4 μg/ml in all cases. Time-kill studies showed that GSK1322322 had bactericidal activity against S. pneumoniae, H. influenzae, S. pyogenes, and S. aureus, demonstrating a ≥3-log10 decrease in the number of CFU/ml at 4× MIC within 24 h in 29 of the 33 strains tested. Given the antibacterial potency demonstrated against this panel of organisms, GSK1322322 represents a valuable alternative therapy for the treatment of infectious diseases caused by drug-resistant pathogens. PMID:23478958

Highly pathogenic beta-hemolytic streptococcal infections in cats from an institutionalized hoarding facility and a multi-species comparison.

PubMed

Morrow, Becky L; McNatt, Rachel; Joyce, Lindsay; McBride, Shelley; Morgan, Daniel; Tressler, Chelsey; Mellits, Cara

2016-04-01

Two hundred and thirty-four cats removed from an institutionalized hoarding facility (IHF) demonstrated severe, atypical pyogenic infections. The objective of this study was to document the various syndromes and determine the etiology of the infections. All cats were evaluated initially after removal from the IHF and on a daily basis for at least 15 months. Samples were collected and sent for culture/susceptibility and histopathology to commercial laboratories or stored at -20(o)C. PCR was performed using universal bacterial primers to amplify the 16S-23S rRNA intergenic spacer region. PCR products were sequenced to determine the identity of the bacteria. Multiple pyogenic syndromes were documented, including abscesses of the paws and carpal/tarsal regions in 82 cats, acute rhinitis with profuse purulent nasal discharge in 68 cats and cervical lymphadenitis with abscessation unassociated with any wounding in 51 cats. Many cats exhibited septic arthritis with total joint destruction, necrotizing fasciitis, meningitis, otitis and septic shock, often leading to death. These infections appeared to be caused by beta-hemolytic streptococci (BHS) based on initial culture results (n = 10), though speciation was unclear and some samples (n = 6) produced no growth. Based on PCR results (n = 26), Streptococcus canis was the only bacterial species or the dominant species identified in each sample, and was the only species present in all the regions associated with the pyogenic infections. Horizontal gene transfer and loss of the cell wall may account for the discrepancy between the culture and PCR results and the highly pathogenic nature of S canis in this particular population of cats. A large-scale hoarding situation with multiple animal species, overcrowding, stress and mixing of animals from many geographical regions created ideal conditions for these events to occur. The specific virulence factors present may be more useful in predicting the pathophysiology of BHS infections than the species of Streptococcus found in the host per se. © ISFM and AAFP 2015.

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

PubMed

You, Yuanhai; Davies, Mark R; Protani, Melinda; McIntyre, Liam; Walker, Mark J; Zhang, Jianzhong

2018-02-01

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 5years 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. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

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

PubMed

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

2016-01-01

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

Antimicrobial Resistance among Respiratory Pathogens in Spain: Latest Data and Changes over 11 Years (1996-1997 to 2006-2007)▿

PubMed Central

Pérez-Trallero, Emilio; Martín-Herrero, Jose E.; Mazón, Ana; García-Delafuente, Celia; Robles, Purificación; Iriarte, Victor; Dal-Ré, Rafael; García-de-Lomas, Juan

2010-01-01

A nationwide multicenter susceptibility surveillance study (Susceptibility to the Antimicrobials Used in the Community in España [SAUCE] project), SAUCE-4, including 2,559 Streptococcus pneumoniae, 2,287 Streptococcus pyogenes, and 2,736 Haemophilus influenzae isolates was carried out from May 2006 to June 2007 in 34 Spanish hospitals. Then, the results from SAUCE-4 were compared to those from all three previous SAUCE studies carried out in 1996-1997, 1998-1999, and 2001-2002 to assess the temporal trends in resistance and the phenotypes of resistance over the 11-year period. In SAUCE-4, on the basis of the CLSI breakpoints, penicillin (parenteral, nonmeningitis breakpoint) and cefotaxime were the antimicrobials that were the most active against S. pneumoniae (99.8% and 99.6%, respectively). Only 0.9% of isolates had a penicillin MIC of ≥2 μg/ml. In S. pyogenes, nonsusceptibility to erythromycin was observed in 19.4% of isolates. Among the H. influenzae isolates, a β-lactamase-positive prevalence of 15.7% was found. A statistically significant temporal decreasing trend over the 11-year period was observed for nonsusceptibility (from 60.0% to 22.9%) and resistance (from 36.5% to 0.9%) to penicillin and for the proportion of erythromycin-resistant isolates of S. pneumoniae of the macrolide-lincosamide-streptogramin B (MLSB) phenotype (from 98.4% to 81.3%). A similar trend was observed for the prevalence of ampicillin resistance (from 37.6% to 16.1%), β-lactamase production (from 25.7% to 15.7%), and β-lactamase-negative ampicillin resistance (BLNAR) in H. influenzae (from 13.5% to 0.7%). Among erythromycin-resistant isolates of S. pyogenes, a significant increasing trend in the prevalence of MLSB was observed (from 7.0% to 35.5%). SAUCE-4 confirms a generalized decline in the resistance of the main respiratory pathogens to the antimicrobials as well as a shift in their resistance phenotypes. PMID:20439616

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

PubMed

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

2007-12-01

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

The Streptococcus pyogenes Serotype M49 Nra-Ralp3 Transcriptional Regulatory Network and Its Control of Virulence Factor Expression from the Novel eno ralp3 epf sagA Pathogenicity Region▿ †

PubMed Central

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

2007-01-01

Many Streptococcus pyogenes (group A streptococcus [GAS]) virulence factor- and transcriptional regulator-encoding genes cluster together in discrete genomic regions. Nra is a central regulator of the FCT region. Previous studies exclusively described Nra as a transcriptional repressor of adhesin and toxin genes. Here transcriptome and proteome analysis of a serotype M49 GAS strain and an isogenic Nra mutant of this strain revealed the complete Nra regulon profile. Nra is active in all growth phases tested, with the largest regulon in the transition phase. Almost exclusively, virulence factor-encoding genes are repressed by Nra; these genes include the GAS pilus operon, the capsule synthesis operon, the cytolysin-mediated translocation system genes, all Mga region core virulence genes, and genes encoding other regulators, like the Ihk/Irr system, Rgg, and two additional RofA-like protein family regulators. Surprisingly, our experiments revealed that Nra additionally acts as a positive regulator, mostly for genes encoding proteins and enzymes with metabolic functions. Epidemiological investigations revealed strong genetic linkage of one particular Nra-repressed regulator, Ralp3 (SPy0735), with a gene encoding Epf (extracellular protein factor from Streptococcus suis). In a serotype-specific fashion, this ralp3 epf gene block is integrated, most likely via transposition, into the eno sagA virulence gene block, which is present in all GAS serotypes. In GAS serotypes M1, M4, M12, M28, and M49 this novel discrete genetic region is therefore designated the eno ralp3 epf sagA (ERES) pathogenicity region. Functional experiments showed that Epf is a novel GAS plasminogen-binding protein and revealed that Ralp3 activity counteracts Nra and MsmR regulatory activity. In addition to the Mga and FCT regions, the ERES region is the third discrete chromosomal pathogenicity region. All of these regions are transcriptionally linked, adding another level of complexity to the known GAS growth phase-dependent regulatory network. PMID:17893125

Zinc Binding and Dimerization of Streptococcus pyogenes Pyrogenic Exotoxin C Are Not Essential for T-Cell Stimulation

DTIC Science & Technology

2003-03-14

streptococcal superantigen binding to MHCII on the surface of cells (7–9), suggesting an essential role in both MHCII molecular recognition and TCR-mediated...extent, mutations of side chains found in a second conserved MHCII alpha-chain-binding site consisting of a hydrophobic surface loop decreased T-cell...fraction of dimer is present at T-cell stimulatory concentrations of Spe-C following mutation of the unpaired side chain of cys- teine at residue 27 to

Fulminant streptococcal toxic shock syndrome.

PubMed

Zavala, S; Arias, M; Legua, P

2018-03-01

We present a case of a previously healthy 37-year-old male who developed fever, nausea, vomiting, diarrhoea, and hypovolaemia. Within 5.5 h he presented with tachycardia, tachypnoea, became hypotensive and displayed a diffuse erythematous rash. In the following hours he developed persistent hypotension, acute respiratory distress syndrome, liver failure, kidney failure and disseminated intravascular coagulation. A diagnosis of toxic shock syndrome was made, but despite antibiotic therapy, immunoglobulin administration, and supportive measures, the patient died 50 h after presentation. Streptococcus pyogenes was isolated from blood cultures.

Characterization and Evolution of Salmonella CRISPR-Cas Systems

DTIC Science & Technology

2014-01-01

aeruginosa and Streptococcus pyogenes ( Cady et al., 2011; Deltcheva et al., 2011). In the former, CRISPR-Cas has been linked to the regulation of...Science 321, 960–964. Cady , K. C., White, A. S., Hammond, J. H., Abendroth, M. D., Karthikeyan, R. S., Lalitha, P., Zegans, M. E. & O’Toole, G. A...40, 5569–5576. Zegans, M. E., Wagner, J. C., Cady , K. C., Murphy, D. M., Hammond, J. H. & O’Toole, G. A. (2009). Interaction between bacteriophage

The influence of specific binding of collagen-silk chimeras to silk biomaterials on hMSC behavior.

PubMed

An, Bo; DesRochers, Teresa M; Qin, Guokui; Xia, Xiaoxia; Thiagarajan, Geetha; Brodsky, Barbara; Kaplan, David L

2013-01-01

Collagen-like proteins in the bacteria Streptococcus pyogenes adopt a triple-helix structure with a thermal stability similar to that of animal collagens, can be expressed in high yield in Escherichia coli and can be easily modified through molecular biology techniques. However, potential applications for such recombinant collagens are limited by their lack of higher order structure to achieve the physical properties needed for most biomaterials. To overcome this problem, the S. pyogenes collagen domain was fused to a repetitive Bombyx mori silk consensus sequence, as a strategy to direct specific non-covalent binding onto solid silk materials whose superior stability, mechanical and material properties have been previously established. This approach resulted in the successful binding of these new collagen-silk chimeric proteins to silk films and porous scaffolds, and the binding affinity could be controlled by varying the number of repeats in the silk sequence. To explore the potential of collagen-silk chimera for regulating biological activity, integrin (Int) and fibronectin (Fn) binding sequences from mammalian collagens were introduced into the bacterial collagen domain. The attachment of bioactive collagen-silk chimeras to solid silk biomaterials promoted hMSC spreading and proliferation substantially in comparison to the controls. The ability to combine the biomaterial features of silk with the biological activities of collagen allowed more rapid cell interactions with silk-based biomaterials, improved regulation of stem cell growth and differentiation, as well as the formation of artificial extracellular matrices useful for tissue engineering applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

PubMed Central

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

2013-01-01

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

Exploring internal features of 16S rRNA gene for identification of clinically relevant species of the genus Streptococcus

PubMed Central

2011-01-01

Background Streptococcus is an economically important genus as a number of species belonging to this genus are human and animal pathogens. The genus has been divided into different groups based on 16S rRNA gene sequence similarity. The variability observed among the members of these groups is low and it is difficult to distinguish them. The present study was taken up to explore 16S rRNA gene sequence to develop methods that can be used for preliminary identification and can supplement the existing methods for identification of clinically-relevant isolates of the genus Streptococcus. Methods 16S rRNA gene sequences belonging to the isolates of S. dysgalactiae, S. equi, S. pyogenes, S. agalactiae, S. bovis, S. gallolyticus, S. mutans, S. sobrinus, S. mitis, S. pneumoniae, S. thermophilus and S. anginosus were analyzed with the purpose to define genetic variability within each species to generate a phylogenetic framework, to identify species-specific signatures and in-silico restriction enzyme analysis. Results The framework based analysis was used to segregate Streptococcus spp. previously identified upto genus level. This segregation was validated using species-specific signatures and in-silico restriction enzyme analysis. 43 uncharacterized Streptococcus spp. could be identified using this approach. Conclusions The markers generated exploring 16S rRNA gene sequences provided useful tool that can be further used for identification of different species of the genus Streptococcus. PMID:21702978

[Differentiation of nonspecific serological reactions in brucellosis].

PubMed

Khristoforov, L

1979-01-01

Differentiation of non-specific agglutination was performed by the complement binding reaction, Coombs' reaction, Hajdu reaction, the surface fixation and agglutination reaction and the reaction of complement binding with heterologic antigens. For that purpose the following were used: 1) Serums--antiglobulin against cattle globulin, 5720 serum of various animals which had manifested non-specific agglutination with brucella antigen and brucella serums of experimentally infected sheep, of naturally infected swine and of cattle--received from abroad. 2) Antigens--of Br. abortus 99, of bacteria heterologic to brucellae: Proteus vulgaris, Listeria monocytogenes, Staphylococcus albus, Escherichia coli, Streptococcus pyogenes, S. abortus ovis, for O and OH agglutination, water extraction antigens--for complement binding and concentrated suspensions of all bacteria used in brucellose and non-brucellose serum absorption. Highest number of non-specific reactions were observed in cattle serums and lowest--in goat serums. Titers with heterologic antigens were higher than these with brucella antigens. Often the serum having non-specific agglutiantion reacted not only with one, but with more heterologic antigens. Non-specific complement binding reactions were not produced in complete antibodies with the brucella antigen. Heterologic brucella antigens were exhausted more fully than heterologic complement binding antibodies. In their effectiveness (differentiation of non-specific agglutination with brucella antigen in cattle serum) the serological reactions studied rank as follows: complement binding reaction, slow agglutination with serums absorbed by heterologic antigens, surface fixation reaction, Coombs' reaction, and Hadju agglutination.

Frequency and expression of mutacin biosynthesis genes in isolates of Streptococcus mutans with different mutacin-producing phenotypes.

PubMed

Kamiya, Regianne Umeko; Höfling, José Francisco; Gonçalves, Reginaldo Bruno

2008-05-01

The aim of this study was to analyse the frequency and expression of biosynthesis genes in 47 Streptococcus mutans isolates with different mutacin-producing phenotypes. Detection of the frequency and expression of genes encoding mutacin types I, II, III and IV were carried out by PCR and semi-quantitative RT-PCR, respectively, using primers specific for each type of biosynthesis gene. In addition, a further eight genes encoding putative bacteriocins, designated bsm 283, bsm 299, bsm 423, bsm 1889c, bsm 1892c, bsm 1896, bsm 1906c and bsm 1914, were also screened. There was a high phenotypic diversity; some Streptococcus mutans isolates presented broad antimicrobial spectra against other Streptococcus mutans clinical isolates, including bacteria resistant to common antibiotics, as well as Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Streptococcus pyogenes. The expression frequency of the bsm gene was higher than that of the previously characterized mutacins (I-IV). There was no positive correlation between the number of indicator strains inhibited (antimicrobial spectra) and the number of biosynthesis genes expressed (Spearman correlation test, r=-0.03, P>0.05). In conclusion, the high diversity of mutacin-producing phenotypes, associated with high frequency of expression of the biosynthesis genes screened, reveals a broad repertoire of genetic determinants encoding antimicrobial peptides that can act in different combinations.

DNA Microarray for Detection of Macrolide Resistance Genes

PubMed Central

Cassone, Marco; D'Andrea, Marco M.; Iannelli, Francesco; Oggioni, Marco R.; Rossolini, Gian Maria; Pozzi, Gianni

2006-01-01

A DNA microarray was developed to detect bacterial genes conferring resistance to macrolides and related antibiotics. A database containing 65 nonredundant genes selected from publicly available DNA sequences was constructed and used to design 100 oligonucleotide probes that could specifically detect and discriminate all 65 genes. Probes were spotted on a glass slide, and the array was reacted with DNA templates extracted from 20 reference strains of eight different bacterial species (Streptococcus pneumoniae, Streptococcus pyogenes, Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, Staphylococcus haemolyticus, Escherichia coli, and Bacteroides fragilis) known to harbor 29 different macrolide resistance genes. Hybridization results showed that probes reacted with, and only with, the expected DNA templates and allowed discovery of three unexpected genes, including msr(SA) in B. fragilis, an efflux gene that has not yet been described for gram-negative bacteria. PMID:16723563

Swine flu and antibiotics.

PubMed

Barlow, Gavin D

2009-11-01

Health services worldwide are likely to be hard-pressed by swine flu-related illness in the months ahead. Secondary infections with Streptococcus pneumoniae, other streptococci (e.g. Streptococcus pyogenes), Haemophilus influenzae and Staphylococcus aureus are likely to be important causes of morbidity and mortality. The UK Department of Health recently published clinical pathways for the management of swine flu. Suggested severity criteria have not been validated in respiratory infection and are different from those previously published. Antibiotics are recommended for all patients assessed at hospital, regardless of severity of illness; cephalosporins or quinolones are suggested for inpatients with pneumonia. These recommendations will jeopardize recent decreases in Clostridium difficile-associated diarrhoea (CDAD) and methicillin-resistant S. aureus (MRSA) in UK hospitals. This article, written on behalf of the BSAC Council, considers these recommendations and provides alternative antibiotic regimens for a range of clinical scenarios.

EndoSd: an IgG glycan hydrolyzing enzyme in Streptococcus dysgalactiae subspecies dysgalactiae.

PubMed

Shadnezhad, Azadeh; Naegeli, Andreas; Sjögren, Jonathan; Adamczyk, Barbara; Leo, Fredrik; Allhorn, Maria; Karlsson, Niclas G; Jensen, Anders; Collin, Mattias

2016-06-01

The aim of this study was to identify and characterize EndoS-like enzymes in Streptococcus dysgalactiae subspecies dysgalactiae (SDSD). PCR, DNA sequencing, recombinant protein expression, lectin blot, ultra high performance liquid chromatography analysis and a chitinase assay were used to identify ndoS-like genes and characterize EndoSd. EndoSd were found in four SDSD strains. EndoSd hydrolyzes the chitobiose core of the glycan on IgG. The amino acid sequence of EndoSd is 70% identical to EndoS in S. pyogenes, but it has a unique C-terminal sequence. EndoSd secretion is influenced by the carbohydrate composition of the growth medium. Our findings indicate that IgG glycan hydrolyzing activity is present in SDSD, and that the activity can be attributed to the here identified enzyme EndoSd.

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

PubMed

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.

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

PubMed Central

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

Crystal structure of Spy0129, a Streptococcus pyogenes class B sortase involved in pilus assembly.

PubMed

Kang, Hae Joo; Coulibaly, Fasséli; Proft, Thomas; Baker, Edward N

2011-01-11

Sortase enzymes are cysteine transpeptidases that mediate the covalent attachment of substrate proteins to the cell walls of gram-positive bacteria, and thereby play a crucial role in virulence, infection and colonisation by pathogens. Many cell-surface proteins are anchored by the housekeeping sortase SrtA but other more specialised sortases exist that attach sub-sets of proteins or function in pilus assembly. The sortase Spy0129, or SrtC1, from the M1 SF370 strain of Streptococcus pyogenes is responsible for generating the covalent linkages between the pilin subunits in the pili of this organism. The crystal structure of Spy0129 has been determined at 2.3 Å resolution (R = 20.4%, Rfree  = 26.0%). The structure shows that Spy0129 is a class B sortase, in contrast to other characterised pilin polymerases, which belong to class C. Spy0129 lacks a flap believed to function in substrate recognition in class C enzymes and instead has an elaborated β6/β7 loop. The two independent Spy0129 molecules in the crystal show differences in the positions and orientations of the catalytic Cys and His residues, Cys221 and His126, correlated with movements of the β7/β8 and β4/β5 loops that respectively follow these residues. Bound zinc ions stabilise these alternative conformations in the crystal. This conformational variability is likely to be important for function although there is no evidence that zinc is involved in vivo.

A Critical Role of Zinc Importer AdcABC in Group A Streptococcus-Host Interactions During Infection and Its Implications for Vaccine Development.

PubMed

Makthal, Nishanth; Nguyen, Kimberly; Do, Hackwon; Gavagan, Maire; Chandrangsu, Pete; Helmann, John D; Olsen, Randall J; Kumaraswami, Muthiah

2017-07-01

Bacterial pathogens must overcome host immune mechanisms to acquire micronutrients for successful replication and infection. Streptococcus pyogenes, also known as group A streptococcus (GAS), is a human pathogen that causes a variety of clinical manifestations, and disease prevention is hampered by lack of a human GAS vaccine. Herein, we report that the mammalian host recruits calprotectin (CP) to GAS infection sites and retards bacterial growth by zinc limitation. However, a GAS-encoded zinc importer and a nuanced zinc sensor aid bacterial defense against CP-mediated growth inhibition and contribute to GAS virulence. Immunization of mice with the extracellular component of the zinc importer confers protection against systemic GAS challenge. Together, we identified a key early stage host-GAS interaction and translated that knowledge into a novel vaccine strategy against GAS infection. Furthermore, we provided evidence that a similar struggle for zinc may occur during other streptococcal infections, which raises the possibility of a broad-spectrum prophylactic strategy against multiple streptococcal pathogens. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Comparison among four proposed direct blood culture microbial identification methods using MALDI-TOF MS.

PubMed

Bazzi, Ali M; Rabaan, Ali A; El Edaily, Zeyad; John, Susan; Fawarah, Mahmoud M; Al-Tawfiq, Jaffar A

Matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry facilitates rapid and accurate identification of pathogens, which is critical for sepsis patients. In this study, we assessed the accuracy in identification of both Gram-negative and Gram-positive bacteria, except for Streptococcus viridans, using four rapid blood culture methods with Vitek MALDI-TOF-MS. We compared our proposed lysis centrifugation followed by washing and 30% acetic acid treatment method (method 2) with two other lysis centrifugation methods (washing and 30% formic acid treatment (method 1); 100% ethanol treatment (method 3)), and picking colonies from 90 to 180min subculture plates (method 4). Methods 1 and 2 identified all organisms down to species level with 100% accuracy, except for Streptococcus viridans, Streptococcus pyogenes, Enterobacter cloacae and Proteus vulgaris. The latter two were identified to genus level with 100% accuracy. Each method exhibited excellent accuracy and precision in terms of identification to genus level with certain limitations. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

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

PubMed Central

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

2002-01-01

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

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

PubMed Central

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

2014-01-01

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

Evolution of sfbI Encoding Streptococcal Fibronectin-Binding Protein I: Horizontal Genetic Transfer and Gene Mosaic Structure

PubMed Central

Towers, Rebecca J.; Fagan, Peter K.; Talay, Susanne R.; Currie, Bart J.; Sriprakash, Kadaba S.; Walker, Mark J.; Chhatwal, Gursharan S.

2003-01-01

Streptococcal fibronectin-binding protein is an important virulence factor involved in colonization and invasion of epithelial cells and tissues by Streptococcus pyogenes. In order to investigate the mechanisms involved in the evolution of sfbI, the sfbI genes from 54 strains were sequenced. Thirty-four distinct alleles were identified. Three principal mechanisms appear to have been involved in the evolution of sfbI. The amino-terminal aromatic amino acid-rich domain is the most variable region and is apparently generated by intergenic recombination of horizontally acquired DNA cassettes, resulting in a genetic mosaic in this region. Two distinct and divergent sequence types that shared only 61 to 70% identity were identified in the central proline-rich region, while variation at the 3′ end of the gene is due to deletion or duplication of defined repeat units. Potential antigenic and functional variabilities in SfbI imply significant selective pressure in vivo with direct implications for the microbial pathogenesis of S. pyogenes. PMID:14662917

In Vivo Tracking of Streptococcal Infections of Subcutaneous Origin in a Murine Model.

PubMed

Davis, Richard W; Eggleston, Heather; Johnson, Frances; Nahrendorf, Matthias; Bock, Paul E; Peterson, Tiffany; Panizzi, Peter

2015-12-01

Generation of plasmin in vivo by Streptococcus pyogenes is thought to localize the active protease complexes to the pathogen surface to aid in tissue dissemination. Here, we chose to follow cutaneous streptococcal infections by the use of non-invasive bioluminescence imaging to determine if this pathogen can be followed by this approach and the extent of bacterial spread in the absence of canonical plasminogen activation by streptokinase. Mice were injected subcutaneously with either bioluminescent strains of streptococci, namely Xen20 and Xen10 or S. pyogenes ALAB49. Bioluminescence imaging was performed daily and results were correlated with microbiological and histological analyses. Comparative analysis of chronologic non-invasive datasets indicated that Xen20 did not disseminate from the initial infection site. Contrary to this, microbiological and histological analyses of Xen20 mice for total bacterial burden indicated sepsis and widespread pathogen involvement. The use of bioluminescence in microbe-based studies requires genomic and pathologic characterization to correlate imaging results with underlying pathology.

Biological screening of some Turkish medicinal plant extracts for antimicrobial and toxicity activities.

PubMed

Turker, A U; Usta, C

2008-01-20

Screening of antibacterial activity and toxicity of 22 aqueous plant extracts from 17 Turkish plants was conducted. Antibacterial activity was performed with six bacteria including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Staphylococcus epidermidis. Extracts of Tussilago farfara leaves, Helichyrsum plicatum flowers, Solanum dulcamara aerial parts and Urtica dioica leaves gave the best inhibitory activity against S. pyogenes, S. aureus and S. epidermidis. Of the 22 plant extracts, 20 extracts displayed toxicity (LC50 was <1000 mg L(-1)) in the brine shrimp bioassay. For radish seed bioassay, two different determinations (root length and seed germination) were performed with a comparison between two concentrations (50,000 mg L(-1) and 10,000 mg L(-1)). At low concentration (10,000 mg L(-1)), S. dulcamara aerial parts and Primula vulgaris leaf extracts were observed to inhibit the root length more than the other plant extracts. Also, the most inhibitive plant extract for seed germination was obtained with S. dulcamara aerial parts.

In Vivo Tracking of Streptococcal Infections of Subcutaneous Origin in a Murine Model

PubMed Central

Davis, Richard W.; Eggleston, Heather; Johnson, Frances; Nahrendorf, Matthias; Bock, Paul E.; Peterson, Tiffany; Panizzi, Peter

2016-01-01

Purpose Generation of plasmin in vivo by Streptococcus pyogenes is thought to localize the active protease complexes to the pathogen surface to aid in tissue dissemination. Here, we chose to follow cutaneous streptococcal infections by the use of non-invasive bioluminescence imaging to determine if this pathogen can be followed by this approach and the extent of bacterial spread in the absence of canonical plasminogen activation by streptokinase. Procedures Mice were injected subcutaneously with either bioluminescent strains of streptococci, namely Xen20 and Xen10 or S. pyogenes ALAB49. Bioluminescence imaging was performed daily and results were correlated with microbiological and histological analyses. Results Comparative analysis of chronologic non-invasive datasets indicated that Xen20 did not disseminate from the initial infection site. Contrary to this, microbiological and histological analyses of Xen20 mice for total bacterial burden indicated sepsis and widespread pathogen involvement. Conclusions The use of bioluminescence in microbe-based studies requires genomic and pathologic characterization to correlate imaging results with underlying pathology. PMID:25921659

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

PubMed

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

2012-09-01

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

Preliminary screening of ethnomedicinal plants from India.

PubMed

Perumal Samy, R; Ignacimuthu, S; Raja, D P

1999-08-01

Antibacterial activity of aqueous residues of 16 different ethnomedicinal plants have been studied. The effect of the aqueous extract at two different weights of plant residues, 30 and 40 mg, were tested against three gram positive bacteria and seven gram negative bacteria by the filter paper disc diffusion method. Among the tested plants, Cleome gynandropsis and Ageratum conyzoides showed a significant control of the growth of Alkaligens viscolactis, Klebsiella aerogenas, Bacillus cerues and Streptococcus pyogens. The maximum inhibitions were observed in Tridax procumbens, Cleome viscosa, Acalypha indica and Boerhaavia erecta against Aeromonas hydrophilla and Bacillus cerues.

Viper Plague Project

DTIC Science & Technology

2009-07-01

labeled with the conjugated Proteus antibody, 40x………………………………………………………………………………………………………………………………………….……18 Figure 10i, 10j. Staphylococcus aureus ...Figure 10i, 10j. Staphylococcus aureus and Streptococcus pyogenes, (gram positive), labeled with the conjugated Proteus antibody, 40x...15 10. Proteus OX19 Aptamer

Dual gene activation and knockout screen reveals directional dependencies in genetic networks. | Office of Cancer Genomics

Cancer.gov

Understanding the direction of information flow is essential for characterizing how genetic networks affect phenotypes. However, methods to find genetic interactions largely fail to reveal directional dependencies. We combine two orthogonal Cas9 proteins from Streptococcus pyogenes and Staphylococcus aureus to carry out a dual screen in which one gene is activated while a second gene is deleted in the same cell. We analyze the quantitative effects of activation and knockout to calculate genetic interaction and directionality scores for each gene pair.

Coenzyme preference of Streptococcus pyogenes δ1-pyrroline-5-carboxylate reductase: evidence supporting NADPH as the physiological electron donor.

PubMed

Petrollino, Davide; Forlani, Giuseppe

2012-07-01

The streptococcal enzyme that catalyzes the last step in proline biosynthesis was heterologously expressed and the recombinant protein was purified to electrophoretic homogeneity and characterized thoroughly. As for δ1-pyrroline-5-carboxylate reductases from other sources, it was able to use either NADH or NADPH as the electron donor in vitro. However, with NADH the activity was markedly inhibited by physiological levels of NADP+. Results also strengthen the possibility that an unusual ordered substrate binding occurs, in which the dinucleotide binds last.

Seasonal variation of streptococcal vulvo-vaginitis in an urban community

PubMed Central

Morris, C. A.

1971-01-01

A study was made of patients investigated by general practitioners. Over a three-year period Streptococcus pyogenes (group A) was isolated most commonly from vaginal and vulval swabs collected in the winter. The serotypes of strains indicate that some had probably been derived from the skin and others from the respiratory tract. The two sources are thought to have masked a consistent, but not obvious, seasonal variation in streptococcal vulvo-vaginitis acquired usually from streptococcal infections of the respiratory tract in winter and from those of the skin in summer. PMID:4946417

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klyachko, N. L.; Dmitrieva, N. F.; Eshchina, A. S.

2008-06-01

Recombinant, phage associated lytic enzyme Ply C capable to lyse streptococci of groups A and C was stabilized in the variety of the micelles containing compositions to improve the stability of the enzyme for further application in medicine. It was shown that, in the micellar polyelectrolyte composition M16, the enzyme retained its activity for 2 months; while in a buffer solution under the same conditions ((pH 6.3, room temperature), it completely lost its activity in 2 days

Identification and Structural Basis of Binding to Host Lung Glycogen by Streptococcal Virulence Factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lammerts van Bueren,A.; Higgins, M.; Wang, D.

2007-01-01

The ability of pathogenic bacteria to recognize host glycans is often essential to their virulence. Here we report structure-function studies of previously uncharacterized glycogen-binding modules in the surface-anchored pullulanases from Streptococcus pneumoniae (SpuA) and Streptococcus pyogenes (PulA). Multivalent binding to glycogen leads to a strong interaction with alveolar type II cells in mouse lung tissue. X-ray crystal structures of the binding modules reveal a novel fusion of tandem modules into single, bivalent functional domains. In addition to indicating a structural basis for multivalent attachment, the structure of the SpuA modules in complex with carbohydrate provides insight into the molecular basismore » for glycogen specificity. This report provides the first evidence that intracellular lung glycogen may be a novel target of pathogenic streptococci and thus provides a rationale for the identification of the streptococcal {alpha}-glucan-metabolizing machinery as virulence factors.« less

The contribution of group A streptococcal virulence determinants to the pathogenesis of sepsis

PubMed Central

Reglinski, Mark; Sriskandan, Shiranee

2014-01-01

Streptococcus pyogenes (group A streptococcus, GAS) is responsible for a wide range of pathologies ranging from mild pharyngitis and impetigo to severe invasive soft tissue infections. Despite the continuing susceptibility of the bacterium to β-lactam antibiotics there has been an unexplained resurgence in the prevalence of invasive GAS infection over the past 30 years. Of particular importance was the emergence of a GAS-associated sepsis syndrome that is analogous to the systemic toxicosis associated with TSST-1 producing strains of Staphylococcus aureus. Despite being recognized for over 20 years, the etiology of GAS associated sepsis and the streptococcal toxic shock syndrome remains poorly understood. Here we review the virulence factors that contribute to the etiology of GAS associated sepsis with a particular focus on coagulation system interactions and the role of the superantigens in the development of streptococcal toxic shock syndrome. PMID:24157731

Streptococcus pyogenes degrades extracellular matrix in chondrocytes via MMP-13

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakurai, Atsuo; Okahashi, Nobuo; Maruyama, Fumito

2008-08-29

Group A streptococcus (GAS) causes a wide range of human diseases, including bacterial arthritis. The pathogenesis of arthritis is characterized by synovial proliferation and the destruction of cartilage and subchondral bone in joints. We report here that GAS strain JRS4 invaded a chondrogenic cell line ATDC5 and induced the degradation of the extracellular matrix (ECM), whereas an isogenic mutant of JRS4 lacking a fibronectin-binding protein, SAM1, failed to invade the chondrocytes or degrade the ECM. Reverse transcription-PCR and Western blot analysis revealed that the expression of matrix metalloproteinase (MMP)-13 was strongly elevated during the infection with GAS. A reporter assaymore » 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.« less

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

PubMed

Rhee, Hanna; Cameron, Daniel J

2012-01-01

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

Antagonistic Rgg regulators mediate quorum sensing via competitive DNA binding in Streptococcus pyogenes.

PubMed

Lasarre, Breah; Aggarwal, Chaitanya; Federle, Michael J

2013-01-02

Recent studies have established the fact that multiple members of the Rgg family of transcriptional regulators serve as key components of quorum sensing (QS) pathways that utilize peptides as intercellular signaling molecules. We previously described a novel QS system in Streptococcus pyogenes which utilizes two Rgg-family regulators (Rgg2 and Rgg3) that respond to neighboring signaling peptides (SHP2 and SHP3) to control gene expression and biofilm formation. We have shown that Rgg2 is a transcriptional activator of target genes, whereas Rgg3 represses expression of these genes, and that SHPs function to activate the QS system. The mechanisms by which Rgg proteins regulate both QS-dependent and QS-independent processes remain poorly defined; thus, we sought to further elucidate how Rgg2 and Rgg3 mediate gene regulation. Here we provide evidence that S. pyogenes employs a unique mechanism of direct competition between the antagonistic, peptide-responsive proteins Rgg2 and Rgg3 for binding at target promoters. The highly conserved, shared binding sites for Rgg2 and Rgg3 are located proximal to the -35 nucleotide in the target promoters, and the direct competition between the two regulators results in concentration-dependent, exclusive occupation of the target promoters that can be skewed in favor of Rgg2 in vitro by the presence of SHP. These results suggest that exclusionary binding of target promoters by Rgg3 may prevent Rgg2 binding under SHP-limiting conditions, thereby preventing premature induction of the quorum sensing circuit. Rgg-family transcriptional regulators are widespread among low-G+C Gram-positive bacteria and in many cases contribute to bacterial physiology and virulence. Only recently was it discovered that several Rgg proteins function in cell-to-cell communication (quorum sensing [QS]) via direct interaction with signaling peptides. The mechanism(s) by which Rgg proteins mediate regulation is poorly understood, and further insight into Rgg function is anticipated to be of great importance for the understanding of both regulatory-network architecture and intercellular communication in Rgg-containing species. The results of this study on the Rgg2/3 QS circuit of S. pyogenes demonstrate that DNA binding of target promoters by the activator Rgg2 is directly inhibited by competitive binding by the repressor Rgg3, thereby preventing transcriptional activation of the target genes and premature induction of the QS circuit. This is a unique regulatory mechanism among Rgg proteins and other peptide-responsive QS regulators.

Acute abdomen due to group A streptococcus bacteremia caused by an isolate with a mutation in the csrS gene.

PubMed

Kaneko, Masahiko; Maruta, Masaki; Shikata, Hisaharu; Hanayama, Masakazu; Ikebe, Tadayoshi

2015-11-01

Streptococcus pyogenes (group A streptococcus) is an aerobic gram-positive coccus that causes infections ranging from non-invasive pharyngitis to severely invasive necrotizing fasciitis. Mutations in csrS/csrR and rgg, negative regulator genes of group A streptococcus, are crucial factors in the pathogenesis of streptococcal toxic shock syndrome, which is a severe, invasive infection characterized by sudden onset of shock and multiorgan failure, resulting in a high mortality rate. Here we present a case of group A streptococcal bacteremia in a 28-year-old Japanese woman with no relevant previous medical history. The patient developed progressive abdominal symptoms that may have been due to spontaneous bacterial peritonitis, followed by a state of shock, which did not fulfill the proposed criteria for streptococcal toxic shock. The isolate was found to harbor a mutation in the negative regulator csrS gene, whereas the csrR and rgg genes were intact. It was noteworthy that this strain carrying a csrS mutation had caused group A streptococcal bacteremia characterized by acute abdomen as the presenting symptom in a young individual who had been previously healthy. This case indicates that group A streptococcus with csrS mutations has potential virulence factors that are associated with the onset of group A streptococcal bacteremia that does not meet the diagnostic criteria for streptococcal toxic shock syndrome. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

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

PubMed

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.

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

PubMed

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

2016-05-01

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

Children hospitalized due to acute otitis media: how does this condition differ from acute mastoiditis?

PubMed

Laulajainen-Hongisto, Anu; Saat, Riste; Lempinen, Laura; Aarnisalo, Antti A; Jero, Jussi

2015-09-01

To evaluate the clinical picture and microbiological findings of children hospitalized due to acute otitis media and to analyze how it differs from acute mastoiditis. A retrospective review of the medical records of all children (0-16 years) hospitalized due to acute otitis media in the Department of Otorhinolaryngology at the Helsinki University Hospital, between 2003 and 2012. Comparison with previously published data of children with acute mastoiditis (n=56) from the same institute and period of time. The most common pathogens in the children hospitalized due to acute otitis media (n=44) were Streptococcus pneumoniae (18%), Pseudomonas aeruginosa (16%), Streptococcus pyogenes (14%), and Staphylococcus aureus (14%). One of the most common pathogens of out-patient acute otitis media, Haemophilus influenzae, was absent. Otorrhea was common in infections caused by S. pyogenes and otorrhea via tympanostomy tube in infections caused by P. aeruginosa. In children under 2 years-of-age, the most common pathogens were S. pneumoniae (43%), Moraxella catarrhalis (14%), and S. aureus (7%). S. pyogenes and P. aeruginosa were only found in children over 2 years-of-age. Previous health problems, bilateral infections, and facial nerve paresis were more common in children hospitalized due to acute otitis media, compared with acute mastoiditis, but they also demonstrated lower CRP values and shorter duration of hospital stay. The number of performed tympanostomies and mastoidectomies was also comparatively smaller in the children hospitalized due to acute otitis media. S. aureus was more common and S. pneumoniae, especially its resistant strains, was less common in the children hospitalized due to acute otitis media than acute mastoiditis. Acute otitis media requiring hospitalization and acute mastoiditis compose a continuum of complicated acute otitis media that differs from common out-patient acute otitis media. The bacteriology of children hospitalized due to acute otitis media resembled more the bacteriology of acute mastoiditis than that of out-patient acute otitis media. The children hospitalized due to acute otitis media needed less surgical treatment and a shorter hospitalization than those hospitalized due to acute mastoiditis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tran, Timothy H.; Christoffersen, S.; Allan, Paula W.

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 hexamermore » 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.« less

Adaptive Evolution of the Streptococcus pyogenes Regulatory Aldolase LacD.1

PubMed Central

Cusumano, Zachary

2013-01-01

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

Prolonged exposure to bacterial toxins downregulated expression of toll-like receptors in mesenchymal stromal cell-derived osteoprogenitors

PubMed Central

Mo, Irene Fung Ying; Yip, Kevin Hak Kong; Chan, Wing Keung; Law, Helen Ka Wai; Lau, Yu Lung; Chan, Godfrey Chi Fung

2008-01-01

Background Human mesenchymal stromal cells (MSCs, also known as mesenchymal stem cells) are multipotent cells with potential therapeutic value. Owing to their osteogenic capability, MSCs may be clinically applied for facilitating osseointegration in dental implants or orthopedic repair of bony defect. However, whether wound infection or oral microflora may interfere with the growth and osteogenic differentiation of human MSCs remains unknown. This study investigated whether proliferation and osteogenic differentiation of MSCs would be affected by potent gram-positive and gram-negative derived bacterial toxins commonly found in human settings. Results We selected lipopolysaccharide (LPS) from Escherichia coli and lipoteichoic acid (LTA) from Streptococcus pyogenes as our toxins of choice. Our findings showed both LPS and LTA did not affect MSC proliferation, but prolonged LPS challenge upregulated the osteogenic differentiation of MSCs, as assessed by alkaline phosphatase activity and calcium deposition. Because toll-like receptors (TLRs), in particularly TLR4 and TLR2, are important for the cellular responsiveness to LPS and LTA respectively, we evaluated their expression profiles serially from MSCs to osteoblasts by quantitative PCR. We found that during osteogenic differentiation, MSC-derived osteoprogenitors gradually expressed TLR2 and TLR4 by Day 12. But under prolonged incubation with LPS, MSC-derived osteoprogenitors had reduced TLR2 and TLR4 gene expression. This peculiar response to LPS suggests a possible adaptive mechanism when MSCs are subjected to continuous exposure with bacteria. Conclusion In conclusion, our findings support the potential of using human MSCs as a biological graft, even under a bacterial toxin-rich environment. PMID:18799018

Spondylodiscitis Caused by Enterobacter agglomerans

PubMed Central

Kothalawala, Mahen; Devakanthan, Balachandran; Arunan, Sinnappoo; Galgamuwa, Dinithi; Rathnayake, Manori

2016-01-01

All over the globe, the incidence of vertebral infection is rising. Nowadays, compared to tuberculous variety, pyogenic spondylodiscitis incidence is high. The increase in the susceptible population and improved diagnostics summatively contributed to this. In clinical grounds, differentiation of pyogenic and tuberculous spondylodiscitis is well defined. Enterobacter agglomerans is a hospital contaminant and associated with infections in immunocompromised individuals and intravenous lines. It causes a wide array of infections. Enterobacter agglomerans spondylodiscitis is unusual and there are, around the globe, only less than 31 suspected cases that have been previously reported. Enterobacter agglomerans histology mimics tuberculous rather than pyogenic spondylodiscitis. A 65-year-old farming lady, while being in hospital, developed sudden onset spastic paraparesis with hyperreflexia. Later blood culture revealed Enterobacter agglomerans with 41-hour incubation in 99.9% probability from Ramel identification system. Her initial ESR was 120 mm/first hour. Isolate was susceptible to ciprofloxacin and intravenous followed with oral therapy shows a drastic ESR fall and improved clinical response. Differentiation of tuberculous and pyogenic spondylodiscitis is very much important in management point of view. Therefore, blood culture has a role in diagnosis of spondylodiscitis. ESR can be used as important inflammatory marker in monitoring the response to treatment. Retrospectively, ESR would aid in reaching a definitive diagnosis. PMID:28127480

Clindamycin Affects Group A Streptococcus Virulence Factors and Improves Clinical Outcome.

PubMed

Andreoni, Federica; Zürcher, Claudia; Tarnutzer, Andrea; Schilcher, Katrin; Neff, Andrina; Keller, Nadia; Marques Maggio, Ewerton; Poyart, Claire; Schuepbach, Reto A; Zinkernagel, Annelies S

2017-01-15

Group A Streptococcus (GAS) has acquired an arsenal of virulence factors, promoting life-threatening invasive infections such as necrotizing fasciitis. Current therapeutic regimens for necrotizing fasciitis include surgical debridement and treatment with cell wall-active antibiotics. Addition of clindamycin (CLI) is recommended, although clinical evidence is lacking. Reflecting the current clinical dilemma, an observational study showed that only 63% of the patients with severe invasive GAS infection received CLI. This work thus aimed to address whether CLI improves necrotizing fasciitis outcome by modulating virulence factors of CLI-susceptible and CLI-resistant GAS in vitro and in vivo. Treatment with CLI reduced extracellular DNase Sda1 and streptolysin O (SLO) activity in vivo, whereas subinhibitory CLI concentrations induced expression and activity of SLO, DNase, and Streptococcus pyogenes cell envelope protease in vitro. Our in vivo results suggest that CLI should be administered as soon as possible to patients with necrotizing fasciitis, while our in vitro studies emphasize that a high dosage of CLI is essential. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

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

PubMed Central

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

2014-01-01

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

Responses of innate immune cells to group A Streptococcus

PubMed Central

Fieber, Christina; Kovarik, Pavel

2014-01-01

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

Group A Streptococcus tissue invasion by CD44-mediated cell signalling

NASA Astrophysics Data System (ADS)

Cywes, Colette; Wessels, Michael R.

2001-12-01

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

Frequency and antimicrobial susceptibility of aerobic bacterial vaginal isolates.

PubMed

Tariq, Nabia; Jaffery, Tara; Ayub, Rukhsana; Alam, Ali Yawar; Javid, Mahmud Haider; Shafique, Shamsa

2006-03-01

To determine the frequency and antimicrobial susceptibility of aerobic bacterial isolates from high vaginal swab cultures. Cross-sectional survey. Shifa International Hospital, Islamabad, from January 2003 to February 2004. The subjects included 136 symptomatic women attending Obstetrics and Gynecology Out-Patient Department. A proforma was filled to document the demographic details, presenting complaint and examination findings. High vaginal swabs were taken for gram staining, culture and antimicrobial sensitivity testing using standard microbiologic techniques. Normal flora was isolated in 30% of the cases, followed by Candida spp. (21.3%), Enterococcus spp. (14.7%), E.coli (10.2%), Beta hemolytic Streptococcus spp. (7.3%), Staphylococcus spp. (4.4%), Enterobacter spp. (4.4%), while Streptococcus pyogenes, Staphylococcus epidermidis and Klebsiella spp. were isolated 1.5% each. Enterococcus, Staphylococcus and Streptococcus were mostly sensitive to penicillin and amoxicillin while E.coli and Klebsiella were sensitive to (piperacillin-Tazobactum, Imipenem and vancomycin. Enterococci species showed significant resistance to aminoglycoside antibiotics (68.8% to 81.3%) resistance to vancomycin was 5%. Thirty percent of symptomatic patients had normal flora on culture. Candida spp was the most frequent pathogen isolated. Co-amoxiclav should be used as empiric therapy until culture-sensitivity report is available.

Anti-lipoteichoic acid antibodies enhance release of cytokines by monocytes sensitized with lipoteichoic acid.

PubMed Central

Mancuso, G; Tomasello, F; Ofek, I; Teti, G

1994-01-01

Lipoteichoic acid (LTA) from gram-positive bacteria can stimulate monocytes to produce cytokines. To ascertain whether aggregation of LTA receptors can contribute to this effect, human monocytes were sensitized with LTA from Streptococcus pyogenes, washed, and treated with anti-LTA antibodies. The addition of anti-LTA antibodies or F(ab')2 fragments markedly enhanced the aggregation of LTA receptors, as evidenced by indirect immunofluorescence and the release of tumor necrosis factor alpha and interleukin-1 beta. These findings suggest that aggregation of LTA receptors of monocytes is required for triggering marked cytokine responses. PMID:8132355

Managing toxic shock syndrome with antibiotics.

PubMed

Annane, Djillali; Clair, Bernard; Salomon, Jérôme

2004-08-01

Toxic shock syndrome (TSS) is a serious disorder with a worldwide prevalence of approximately 3/100,000 persons. TSS is mainly caused by Streptococcus pyogenes or Staphylococcus aureus. Thus, beta-lactam and lincosamides, such as clindamycin, are the first-line drugs. Yet, the mortality rate remains unacceptably high; highlighting the role of bacterial toxin-mediated activation of the inflammatory cascade in TSS pathogenesis. Further strategies should be targeted towards interfering with the interaction between bacterial toxins and host T cells. This paper aims to provide an overview of the epidemiology, pathomechanisms, and clinical presentation of TSS, and criteria for selecting drugs among available antibiotics.

[Toxic shock syndrome].

PubMed

Tyll, T; Bílková, M; Revinová, A; Müller, M; Čurdová, M; Zlámal, M; Holub, M

2015-10-01

The authors present an up-to-date review of toxic shock syndrome (TSS) - a life-threatening condition where toxins of the Gram-positive bacteria Staphyloccocus aureus and Streptococcus pyogenes play a key role in the pathogenesis. The authors provide insight into the epidemiology and pathogenesis of the disease and point out the relevant patient history data and clinical signs and symptoms that may indicate progression of TSS. Last but not least, the state of the art diagnostic and therapeutic approaches to early and full blown TSS are summarized. Case reports are presented to illustrate two different etiological forms of this relatively rare nosological entity.

A new sclerosant therapy for testicular hydrocele with aspiration and injection of OK-432.

PubMed

Yamamoto, M; Hibi, H; Miyake, K

1994-01-01

Twenty patients with testicular hydrocele were treated with a new sclerosing therapy consisting of intrascrotal injection of OK-432 (group A Streptococcus pyogenes of human origin). The median observation period after treatment was 6 months (range 2-13 months). Eighteen patients required only one treatment. Two patients had recurrences and received repeat injection. There have been no serious side effects except for fever of 2-3 days' duration and local inflammatory reaction. Sclerotherapy with OK-432 is an efficient and easy method which can be recommended as a primary treatment for hydrocele.

Peptidoglycan and lipoteichoic acid, components of the streptococcal cell wall, have marked and differential effects on adhesion molecule expression and the production of reactive oxygen species in human whole blood leukocytes.

PubMed

Saetre, T; Kähler, H; Foster, S J; Lyberg, T

2000-07-01

To elucidate the pathophysiology of infections with Streptococcus pyogenes we applied flow cytometric techniques to study dose-response and time-related effects of the streptococcal cell-wall-derived components lipoteichoic acid (LTA 0.005 to 50 microg/ml) and peptidoglycan (10 and 100 microg/ml) on the expression of leukocyte adhesion molecules, the CD14 receptor, and the production of leukocyte reactive oxygen species (ROS). LTA (50 microg/ml, 1-2 h) markedly increased the expression of CD11b (approximately 5-fold), CD11c (approximately 2-fold) and CD11a. Concomitantly, CD62L was downregulated (60%). Peptidoglycan alone or in combination with LTA had little effect on adhesion molecules, except for an amplification of the downregulation of CD62L to 90%. Monocyte CD14 expression was doubled by LTA. Leukocyte ROS production was 10-fold and 5-fold increased by peptidoglycan in granulocytes and monocytes, respectively. LTA alone had no effect, while the combination of peptidoglycan with LTA doubled the increase in ROS caused by peptidoglycan. LTA and peptidoglycan had marked and differential effects: LTA caused mainly adhesion molecule modulation, whereas peptidoglycan mainly increased ROS production. These changes are important in inflammatory cell activation and recruitment, intracellular microbial killing and adverse tissue injury.

Identification of clinically relevant viridans streptococci by an oligonucleotide array.

PubMed

Chen, Chao Chien; Teng, Lee Jene; Kaiung, Seng; Chang, Tsung Chain

2005-04-01

Viridans streptococci (VS) are common etiologic agents of subacute infective endocarditis and are capable of causing a variety of pyogenic infections. Many species of VS are difficult to differentiate by phenotypic traits. An oligonucleotide array based on 16S-23S rRNA gene intergenic spacer (ITS) sequences was developed to identify 11 clinically relevant VS. These 11 species were Streptococcus anginosus, S. constellatus, S. gordonii, S. intermedius, S. mitis, S. mutans, S. oralis, S. parasanguinis, S. salivarius, S. sanguinis, and S. uberis. The method consisted of PCR amplification of the ITS regions by using a pair of universal primers, followed by hybridization of the digoxigenin-labeled PCR products to a panel of species-specific oligonucleotides immobilized on a nylon membrane. After 120 strains of the 11 species of VG and 91 strains of other bacteria were tested, the sensitivity and specificity of the oligonucleotide array were found to be 100% (120 of 120 strains) and 95.6% (87 of 91 strains), respectively. S. pneumoniae cross-hybridized to the probes used for the identification of S. mitis, and simple biochemical tests such as optochin susceptibility or bile solubility should be used to differentiate S. pneumoniae from S. mitis. In conclusion, identification of species of VS by use of the present oligonucleotide array is accurate and could be used as an alternative reliable method for species identification of strains of VS.

Outbreak of pyogenic abscesses after diphtheria and tetanus toxoids and pertussis vaccination.

PubMed

Simon, P A; Chen, R T; Elliott, J A; Schwartz, B

1993-05-01

Nine children who received diphtheria and tetanus toxoids and pertussis vaccine from the same vial at a clinic in Colorado developed pyogenic abscesses at the site of injection. Eight abscesses required surgical drainage and five children were hospitalized. Group A Streptococcus (GAS) was cultured from eight wounds and Staphylococcus aureus was also isolated from four. Epidemiologic investigation revealed that within the hour of the first child's vaccination, three children had been diagnosed in the clinic with GAS pharyngitis. GAS recovered from repeat throat swabs from two of these children and the eight case-isolates were all serotype M-12, T-12 and had identical immunoblot patterns on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Laboratory simulation studies demonstrated that GAS can survive for at least 4 days on the external surface of a vaccine vial rubber stopper and contaminate needles inserted through the stopper. Swabbing the stopper with 70% isopropyl alcohol resulted in effective disinfection. To prevent potential contamination meticulous attention to sterile technique is important when withdrawing vaccine from multidose vaccine vials.

Synthesis, characterization and antimicrobial studies of Schiff base complexes

NASA Astrophysics Data System (ADS)

Zafar, Hina; Ahmad, Anis; Khan, Asad U.; Khan, Tahir Ali

2015-10-01

The Schiff base complexes, MLCl2 [M = Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)] have been synthesized by the template reaction of respective metal ions with 2-acetylpyrrole and 1,3-diaminopropane in 1:2:1 M ratio. The complexes have been characterized by elemental analyses, ESI - mass, NMR (1H and 13C), IR, XRD, electronic and EPR spectral studies, magnetic susceptibility and molar conductance measurements. These studies show that all the complexes have octahedral arrangement around the metal ions. The molar conductance measurements of all the complexes in DMSO indicate their non-electrolytic nature. The complexes were screened for their antibacterial activity in vitro against Gram-positive (Streptococcus pyogenes) and Gram-negative (Klebsiella pneumoniae) bacteria. Among the metal complexes studied the copper complex [CuLCl2], showed highest antibacterial activity nearly equal to standard drug ciprofloxacin. Other complexes also showed considerable antibacterial activity. The relative order of activity against S. Pyogenes is as Cu(II) > Zn(II) > Co(II) = Fe(II) > Ni(II) and with K. Pneumonia is as Cu(II) > Co(II) > Zn(II) > Fe(II) > Ni(II).

Using the CRISPR/Cas9 system to eliminate native plasmids of Zymomonas mobilis ZM4.

PubMed

Cao, Qing-Hua; Shao, Huan-Huan; Qiu, Hui; Li, Tao; Zhang, Yi-Zheng; Tan, Xue-Mei

2017-03-01

The CRISPR/Cas system can be used to simply and efficiently edit the genomes of various species, including animals, plants, and microbes. Zymomonas mobilis ZM4 is a highly efficient, ethanol-producing bacterium that contains five native plasmids. Here, we constructed the pSUZM2a-Cas9 plasmid and a single-guide RNA expression plasmid. The pSUZM2a-Cas9 plasmid was used to express the Cas9 gene cloned from Streptococcus pyogenes CICC 10464. The single-guide RNA expression plasmid pUC-T7sgRNA, with a T7 promoter, can be used for the in vitro synthesis of single-guide RNAs. This system was successfully employed to knockout the upp gene of Escherichia coli and the replicase genes of native Z. mobilis plasmids. This is the first study to apply the CRISPR/Cas9 system of S. pyogenes to eliminate native plasmids in Z. mobilis. It provides a new method for plasmid curing and paves the way for the genomic engineering of Z. mobilis.

Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae.

PubMed

Wang, Deguo; Liu, Yanhong

2015-05-26

Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactiae, S. uberis and S. agalactiae. The detection limit of all four LAMP primer sets were 0.1 pg DNA template per reaction, the LAMP method with 16S rRNA gene and 16S-23S rRNA intergenic spacers as the targets can differentiate the three pathogens, which is potentially useful in epidemiological studies.

Acute Post-Streptococcal Glomerulonephritis in the Northern Territory of Australia: A Review of 16 Years Data and Comparison with the Literature

PubMed Central

Marshall, Catherine S.; Cheng, Allen C.; Markey, Peter G.; Towers, Rebecca J.; Richardson, Leisha J.; Fagan, Peter K.; Scott, Lesley; Krause, Vicki L.; Currie, Bart J.

2011-01-01

Data relating to acute post-streptococcal glomerulonephritis (APSGN) from the notifiable diseases surveillance system in the Northern Territory of Australia was extracted and analyzed. Isolates of Streptococcus pyogenes from confirmed cases were emm sequence typed. From 1991 to July 2008, there were 415 confirmed cases and 23 probable cases of APSGN notified. Four hundred fifteen (94.7%) of these were Indigenous Australians and 428 (97.7%) were people living in remote or very remote locations. The median age of cases was 7 years (range 0–54). The incidence of confirmed cases was 12.5/100,000 person-years, with an incidence in Indigenous Australian children younger than 15 years of age of 94.3 cases/100,000 person-years. The overall rate ratio of confirmed cases in Indigenous Australians to non-Indigenous Australians was 53.6 (95% confidence interval 32.6–94.8). Outbreaks of disease across multiple communities occurred in 1995 (N = 68), 2000 (N = 55), and 2005 (N = 87 [confirmed cases]). Various emm types of S. pyogenes were isolated from cases of APSGN including some types not previously recognized to be nephritogenic. The widespread outbreak in 2005 was caused by emm55.0 S. pyogenes. Acute post-streptococcal glomerulonephritis continues to occur in remote Indigenous communities in Australia at rates comparable to or higher than those estimated in developing countries. Improvements in preventative and outbreak control strategies are needed. PMID:21976576

Acute post-streptococcal glomerulonephritis in the Northern Territory of Australia: a review of 16 years data and comparison with the literature.

PubMed

Marshall, Catherine S; Cheng, Allen C; Markey, Peter G; Towers, Rebecca J; Richardson, Leisha J; Fagan, Peter K; Scott, Lesley; Krause, Vicki L; Currie, Bart J

2011-10-01

Data relating to acute post-streptococcal glomerulonephritis (APSGN) from the notifiable diseases surveillance system in the Northern Territory of Australia was extracted and analyzed. Isolates of Streptococcus pyogenes from confirmed cases were emm sequence typed. From 1991 to July 2008, there were 415 confirmed cases and 23 probable cases of APSGN notified. Four hundred fifteen (94.7%) of these were Indigenous Australians and 428 (97.7%) were people living in remote or very remote locations. The median age of cases was 7 years (range 0-54). The incidence of confirmed cases was 12.5/100,000 person-years, with an incidence in Indigenous Australian children younger than 15 years of age of 94.3 cases/100,000 person-years. The overall rate ratio of confirmed cases in Indigenous Australians to non-Indigenous Australians was 53.6 (95% confidence interval 32.6-94.8). Outbreaks of disease across multiple communities occurred in 1995 (N = 68), 2000 (N = 55), and 2005 (N = 87 [confirmed cases]). Various emm types of S. pyogenes were isolated from cases of APSGN including some types not previously recognized to be nephritogenic. The widespread outbreak in 2005 was caused by emm55.0 S. pyogenes. Acute post-streptococcal glomerulonephritis continues to occur in remote Indigenous communities in Australia at rates comparable to or higher than those estimated in developing countries. Improvements in preventative and outbreak control strategies are needed.

Antimicrobial activity of traditional medicinal plants from Ankober District, North Shewa Zone, Amhara Region, Ethiopia.

PubMed

Lulekal, E; Rondevaldova, J; Bernaskova, E; Cepkova, J; Asfaw, Z; Kelbessa, E; Kokoska, L; Van Damme, P

2014-05-01

Traditional medicinal plants have long been used in Ethiopia to treat human and livestock ailments. Despite a well-documented rich tradition of medicinal plant use in the country, their direct antimicrobial effects are still poorly known. To investigate the antimicrobial activity of 19 medicinal plant species that were selected based on the ethnobotanical information on their traditional use to treat infectious diseases in Ankober District. About 23 different ethanol extracts of plants obtained by maceration of various parts of 19 medicinal plant species were studied for potential antimicrobial activity using a broth microdilution method against Bacillus cereus, Bacteroides fragilis, Candida albicans, Clostridium perfringens, Enterococcus faecalis, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enteritidis, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes. Plant extracts from Embelia schimperi Vatke (Myrsinaceae) showed the strongest antibacterial activity with a minimum inhibitory concentration (MIC) value of 64 µg/ml against B. cereus, L. monocytogenes, and S. pyogenes. Growth inhibitory activities were also observed for extracts of Ocimum lamiifolium Hochst. (Lamiaceae) against S. pyogenes, and those of Rubus steudneri Schweinf. (Rosaceae) against S. epidermidis at an MIC value of 128 µg/ml. Generally, 74% of ethanol extracts (17 extracts) showed antimicrobial activity against one or more of the microbial strains tested at an MIC value of 512 µg/ml or below. Results confirm the antimicrobial role of traditional medicinal plants of Ankober and warrant further investigations on promising medicinal plant species so as to isolate and characterise chemicals responsible for the observed strong antimicrobial activities.

STUDIES ON THE BIOLOGY OF STREPTOCOCCUS

PubMed Central

Stevens, Franklin A.; Dochez, A. R.

1926-01-01

1. Strains of hemolytic streptococci isolated from cases of erysipelas agglutinate in a high percentage of instances with erysipelas immune sera. When agglutination occurs with one serum, the strain usually agglutinates with all other erysipelas sera. 2. Erysipelas immune sera agglutinate strains from erysipelas in a higher percentage of instances than they agglutinate scarlatinal strains. 3. Strains from miscellaneous pyogenic infections may agglutinate in these sera, but the percentage of positive reactions is low and a strain usually agglutinates in but one or two of several sera. 4. Erysipelas strains which agglutinate in immune sera are not necessarily identical, although identical strains may occur. Similarly, identical strains may occur among scarlatinal strains agglutinated by scarlatinal immune sera. 5. Erysipelas strains form a closely related group of hemolytic streptococci. Scarlatinal strains form an equally compact group. The two groups are related antigenically but less closely related than the strains within the groups. These groups are related to pyogenic strains, but less closely than they are related to each other. 6. Erysipelas, scarlatinal, or pyogenic strains which agglutinate in erysipelas or scarlatinal sera are capable of absorbing the agglutinin for all other strains except the homologous strain and strains identical with it. Strains identical with the homologous strain absorb the agglutinin completely. 7. Erysipelas or scarlatinal strains may absorb the common group agglutinin from their respective sera, when they are incapable of agglutination in these sera. 8. The agglutinogen is probably of complex or composite nature, with characteristic variations in the scarlet fever and erysipelas groups. PMID:19869130

Inhibition of NHEJ repair by type II-A CRISPR-Cas systems in bacteria.

PubMed

Bernheim, Aude; Calvo-Villamañán, Alicia; Basier, Clovis; Cui, Lun; Rocha, Eduardo P C; Touchon, Marie; Bikard, David

2017-12-12

Type II CRISPR-Cas systems introduce double-strand breaks into DNA of invading genetic material and use DNA fragments to acquire novel spacers during adaptation. These breaks can be the substrate of several DNA repair pathways, paving the way for interactions. We report that non-homologous end-joining (NHEJ) and type II-A CRISPR-Cas systems only co-occur once among 5563 fully sequenced prokaryotic genomes. We investigated experimentally the possible molecular interactions using the NHEJ pathway from Bacillus subtilis and the type II-A CRISPR-Cas systems from Streptococcus thermophilus and Streptococcus pyogenes. Our results suggest that the NHEJ system has no effect on CRISPR immunity. On the other hand, we provide evidence for the inhibition of NHEJ repair by the Csn2 protein. Our findings give insights on the complex interactions between CRISPR-Cas systems and repair mechanisms in bacteria, contributing to explain the scattered distribution of CRISPR-Cas systems in bacterial genome.

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

PubMed Central

Rhee, Hanna; Cameron, Daniel J

2012-01-01

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

New Insights into the Role of Zinc Acquisition and Zinc Tolerance in Group A Streptococcal Infection.

PubMed

Ong, Cheryl-Lynn Y; Berking, Olga; Walker, Mark J; McEwan, Alastair G

2018-06-01

Zinc plays an important role in host innate immune function. However, the innate immune system also utilizes zinc starvation ("nutritional immunity") to combat infections. Here, we investigate the role of zinc import and export in the protection of Streptococcus pyogenes (group A Streptococcus ; GAS), a Gram-positive bacterial pathogen responsible for a wide spectrum of human diseases, against challenge from host innate immune defense. In order to determine the role of GAS zinc import and export during infection, we utilized zinc import (Δ adcA Δ adcAII ) and export (Δ czcD ) deletion mutants in competition with the wild type in both in vitro and in vivo virulence models. We demonstrate that nutritional immunity is deployed extracellularly, while zinc toxicity is utilized upon phagocytosis of GAS by neutrophils. We also show that lysosomes and azurophilic granules in neutrophils contain zinc stores for use against intracellular pathogens. Copyright © 2018 American Society for Microbiology.

Preclinical immunogenicity and safety of a Group A streptococcal M protein-based vaccine candidate.

PubMed

Batzloff, Michael R; Fane, Anne; Gorton, Davina; Pandey, Manisha; Rivera-Hernandez, Tania; Calcutt, Ainslie; Yeung, Grace; Hartas, Jon; Johnson, Linda; Rush, Catherine M; McCarthy, James; Ketheesan, Natkunam; Good, Michael F

2016-12-01

Streptococcus pyogenes (group A streptococcus, GAS) causes a wide range of clinical manifestations ranging from mild self-limiting pyoderma to invasive diseases such as sepsis. Also of concern are the post-infectious immune-mediated diseases including rheumatic heart disease. The development of a vaccine against GAS would have a large health impact on populations at risk of these diseases. However, there is a lack of suitable models for the safety evaluation of vaccines with respect to post-infectious complications. We have utilized the Lewis Rat model for cardiac valvulitis to evaluate the safety of the J8-DT vaccine formulation in parallel with a rabbit toxicology study. These studies demonstrated that the vaccine did not induce abnormal pathology. We also show that in mice the vaccine is highly immunogenic but that 3 doses are required to induce protection from a GAS skin challenge even though 2 doses are sufficient to induce a high antibody titer.

Accurate Detection of Streptococcus pyogenes at the Point of Care Using the cobas Liat Strep A Nucleic Acid Test.

PubMed

Wang, Fangnian; Tian, Yu; Chen, Lingjun; Luo, Robert; Sickler, Joanna; Liesenfeld, Oliver; Chen, Shuqi

2017-10-01

The performance of a polymerase chain reaction-based point-of-care assay, the cobas Strep A Nucleic Acid Test for use on the cobas Liat System (cobas Liat Strep A assay), for the detection of group A Streptococcus bacteria was evaluated in primary care settings. Throat swab specimens from 427 patients were tested with the cobas Liat Strep A assay and a rapid antigen detection test (RADT) by existing medical staff at 5 primary care clinics, and results were compared with bacterial culture. The cobas Liat Strep A assay demonstrated equivalent sensitivity (97.7%) and specificity (93.3%) to reference culture with a 15-minute turnaround time. In comparison to RADTs, the cobas Liat Strep A assay showed improved sensitivity (97.7% Liat vs 84.5% RADT). The Clinical Laboratory Improvement Amendments-waived cobas Liat Strep A assay demonstrated the ease of use and improved turnaround time of RADTs along with the sensitivity of culture.

Preclinical immunogenicity and safety of a Group A streptococcal M protein-based vaccine candidate

PubMed Central

Batzloff, Michael R.; Fane, Anne; Gorton, Davina; Pandey, Manisha; Rivera-Hernandez, Tania; Calcutt, Ainslie; Yeung, Grace; Hartas, Jon; Johnson, Linda; Rush, Catherine M.; McCarthy, James; Ketheesan, Natkunam; Good, Michael F.

2016-01-01

ABSTRACT Streptococcus pyogenes (group A streptococcus, GAS) causes a wide range of clinical manifestations ranging from mild self-limiting pyoderma to invasive diseases such as sepsis. Also of concern are the post-infectious immune-mediated diseases including rheumatic heart disease. The development of a vaccine against GAS would have a large health impact on populations at risk of these diseases. However, there is a lack of suitable models for the safety evaluation of vaccines with respect to post-infectious complications. We have utilized the Lewis Rat model for cardiac valvulitis to evaluate the safety of the J8-DT vaccine formulation in parallel with a rabbit toxicology study. These studies demonstrated that the vaccine did not induce abnormal pathology. We also show that in mice the vaccine is highly immunogenic but that 3 doses are required to induce protection from a GAS skin challenge even though 2 doses are sufficient to induce a high antibody titer. PMID:27541593

Multistep Resistance Development Studies of Ceftaroline in Gram-Positive and -Negative Bacteria▿

PubMed Central

Clark, Catherine; McGhee, Pamela; Appelbaum, Peter C.; Kosowska-Shick, Klaudia

2011-01-01

Ceftaroline, the active component of the prodrug ceftaroline fosamil, is a novel broad-spectrum cephalosporin with bactericidal activity against Gram-positive and -negative isolates. This study evaluated the potential for ceftaroline and comparator antibiotics to select for clones of Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, Moraxella catarrhalis, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis with elevated MICs. S. pneumoniae and S. pyogenes isolates in the present study were highly susceptible to ceftaroline (MIC range, 0.004 to 0.25 μg/ml). No streptococcal strains yielded ceftaroline clones with increased MICs (defined as an increase in MIC of >4-fold) after 50 daily passages. Ceftaroline MICs for H. influenzae and M. catarrhalis were 0.06 to 2 μg/ml for four strains and 8 μg/ml for a β-lactamase-positive, efflux-positive H. influenzae with a mutation in L22. One H. influenzae clone with an increased ceftaroline MIC (quinolone-resistant, β-lactamase-positive) was recovered after 20 days. The ceftaroline MIC for this isolate increased 16-fold, from 0.06 to 1 μg/ml. MICs for S. aureus ranged from 0.25 to 1 μg/ml. No S. aureus isolates tested with ceftaroline had clones with increased MIC (>4-fold) after 50 passages. Two E. faecalis isolates tested had ceftaroline MICs increased from 1 to 8 μg/ml after 38 days and from 4 to 32 μg/ml after 41 days, respectively. The parental ceftaroline MIC for the one K. pneumoniae extended-spectrum β-lactamase-negative isolate tested was 0.5 μg/ml and did not change after 50 daily passages. PMID:21343467

Results from the Survey of Antibiotic Resistance (SOAR) 2011–13 in the Gulf States

PubMed Central

Jamsheer, A.; Rafay, A. M.; Daoud, Z.; Morrissey, I.; Torumkuney, D.

2016-01-01

Objectives To provide surveillance data on the susceptibility of community-acquired respiratory tract isolates from four Gulf and Near East countries from 2011 to 2013. Methods MICs were determined using Etests® for all antibiotics evaluated except erythromycin, where testing was by disc diffusion. Susceptibility was assessed using CLSI, EUCAST and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints. Results Seven hundred and twenty-six respiratory isolates comprising 265 isolates of Streptococcus pneumoniae, 125 isolates of Streptococcus pyogenes and 336 isolates of Haemophilus influenzae were collected from Bahrain, Lebanon, Oman and the United Arab Emirates (UAE). Among S. pneumoniae, susceptibility to penicillin was low in the UAE and Bahrain. Macrolide susceptibility was ∼45%–60% in the UAE and Oman but higher in Lebanon (73.7%) and Bahrain (84%–85%). Penicillin susceptibility using CLSI intravenous breakpoints was >85% in all countries. Antibiotic susceptibility of S. pneumoniae was lower in UAE and Oman. Among S. pyogenes isolates, resistance to erythromycin was highest in Oman (31.6%) but <20% in the other countries. In H. influenzae, susceptibility to most antibiotics was high, except for ampicillin in Lebanon (70.2%) and amoxicillin in Oman (95.4%). Lebanon also had a high percentage (14.9%) of β-lactamase-positive isolates with non-susceptibility to ampicillin. Amoxicillin/clavulanic acid susceptibility was >95% in all countries. Use of EUCAST versus CLSI breakpoints demonstrated profound differences for cefaclor and cefuroxime in S. pneumoniae and H. influenzae, with EUCAST showing lower susceptibility. Conclusions There was considerable variability in susceptibility among countries in the same region. Thus, continued surveillance is necessary to track future changes in antibiotic resistance. PMID:27048582

Results from the Survey of Antibiotic Resistance (SOAR) 2012–14 in Thailand, India, South Korea and Singapore

PubMed Central

Torumkuney, D.; Chaiwarith, R.; Reechaipichitkul, W.; Malatham, K.; Chareonphaibul, V.; Rodrigues, C.; Chitins, D. S.; Dias, M.; Anandan, S.; Kanakapura, S.; Park, Y. J.; Lee, K.; Lee, H.; Kim, J. Y.; Lee, Y.; Lee, H. K.; Kim, J. H.; Tan, T. Y.; Heng, Y. X.; Mukherjee, P.; Morrissey, I.

2016-01-01

Objectives To provide susceptibility data for community-acquired respiratory tract isolates of Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae and Moraxella catarrhalis collected in 2012–14 from four Asian countries. Methods MICs were determined using Etest® for all antibiotics except erythromycin, which was evaluated by disc diffusion. Susceptibility was assessed using CLSI, EUCAST and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints. For macrolide/clindamycin interpretation, breakpoints were adjusted for incubation in CO2 where available. Results Susceptibility of S. pneumoniae was generally lower in South Korea than in other countries. Penicillin susceptibility assessed using CLSI oral or EUCAST breakpoints ranged from 21.2% in South Korea to 63.8% in Singapore. In contrast, susceptibility using CLSI intravenous breakpoints was much higher, at 79% in South Korea and ∼95% or higher elsewhere. Macrolide susceptibility was ∼20% in South Korea and ∼50%–60% elsewhere. Among S. pyogenes isolates (India only), erythromycin susceptibility (∼20%) was lowest of the antibiotics tested. In H. influenzae antibiotic susceptibility was high except for ampicillin, where susceptibility ranged from 16.7% in South Korea to 91.1% in India. South Korea also had a high percentage (18.1%) of β-lactamase-negative ampicillin-resistant isolates. Amoxicillin/clavulanic acid susceptibility for each pathogen (PK/PD high dose) was between 93% and 100% in all countries except for H. influenzae in South Korea (62.5%). Conclusions Use of EUCAST versus CLSI breakpoints had profound differences for cefaclor, cefuroxime and ofloxacin, with EUCAST showing lower susceptibility. There was considerable variability in susceptibility among countries in the same region. Thus, continued surveillance is necessary to track future changes in antibiotic resistance. PMID:27048580

Epidemiology and emm types of invasive group A streptococcal infections in Finland, 2008-2013.

PubMed

Smit, P W; Lindholm, L; Lyytikäinen, O; Jalava, J; Pätäri-Sampo, A; Vuopio, J

2015-10-01

Invasive Streptococcus pyogenes (group A streptococcus, GAS) infections are a major global cause of morbidity and mortality. We analysed the surveillance data on invasive GAS and the microbiological characteristics of corresponding isolates to assess the incidence and emm type distribution of invasive GAS infections in Finland. Cases defined as patients with isolations of blood and cerebrospinal fluid S. pyogenes are mandatorily notified to the National Infectious Disease Registry and sent to the national reference laboratory for emm typing. Antimicrobial data were collected through the network including all clinical microbiology laboratories. Pulsed-field gel electrophoresis (PFGE) analysis was performed to assess clonality. In total, 1165 cases of invasive GAS were reported in Finland during 2008-2013; the median age was 52 years (range, 0-100) and 54% were male. The overall day 7 case fatality rate was 5.1% (59 cases). The average annual incidence was 3.6 cases per 100,000 population. A total of 1122 invasive GAS isolates (96%) were analysed by emm typing; 72 different emm types were identified, of which emm28 (297 isolates, 26%), emm89 (193 isolates, 12%) and emm1 (132 isolates, 12%) were the most common types. During 2008-2013, an increase of erythromycin resistance (1.9% to 8.7%) and clindamycin (0.9% to 9.2%) was observed. This resistance increase was in parallel with the introduction of a novel clone emm33 into Finland. The overall incidence of invasive GAS infections remained stable over the study period in Finland. We identified clonal spread of macrolide-resistant invasive emm33 GAS type, highlighting the importance of molecular surveillance.

Identification of Quorum-Sensing Inhibitors Disrupting Signaling between Rgg and Short Hydrophobic Peptides in Streptococci

PubMed Central

Aggarwal, Chaitanya; Jimenez, Juan Cristobal; Lee, Hyun; Chlipala, George E.; Ratia, Kiira

2015-01-01

ABSTRACT Bacteria coordinate a variety of social behaviors, important for both environmental and pathogenic bacteria, through a process of intercellular chemical signaling known as quorum sensing (QS). As microbial resistance to antibiotics grows more common, a critical need has emerged to develop novel anti-infective therapies, such as an ability to attenuate bacterial pathogens by means of QS interference. Rgg quorum-sensing pathways, widespread in the phylum Firmicutes, employ cytoplasmic pheromone receptors (Rgg transcription factors) that directly bind and elicit gene expression responses to imported peptide signals. In the human-restricted pathogen Streptococcus pyogenes, the Rgg2/Rgg3 regulatory circuit controls biofilm development in response to the short hydrophobic peptides SHP2 and SHP3. Using Rgg-SHP as a model receptor-ligand target, we sought to identify chemical compounds that could specifically inhibit Rgg quorum-sensing circuits. Individual compounds from a diverse library of known drugs and drug-like molecules were screened for their ability to disrupt complexes of Rgg and FITC (fluorescein isothiocyanate)-conjugated SHP using a fluorescence polarization (FP) assay. The best hits were found to bind Rgg3 in vitro with submicromolar affinities, to specifically abolish transcription of Rgg2/3-controlled genes, and to prevent biofilm development in S. pyogenes without affecting bacterial growth. Furthermore, the top hit, cyclosporine A, as well as its nonimmunosuppressive analog, valspodar, inhibited Rgg-SHP pathways in multiple species of Streptococcus. The Rgg-FITC-peptide-based screen provides a platform to identify inhibitors specific for each Rgg type. Discovery of Rgg inhibitors constitutes a step toward the goal of manipulating bacterial behavior for purposes of improving health. PMID:25968646

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

PubMed Central

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

2010-01-01

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

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

PubMed

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

2010-08-01

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

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

PubMed Central

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

2013-01-01

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

Assembly mechanism of FCT region type 1 pili in serotype M6 Streptococcus pyogenes.

PubMed

Nakata, Masanobu; Kimura, Keiji Richard; Sumitomo, Tomoko; Wada, Satoshi; Sugauchi, Akinari; Oiki, Eiji; Higashino, Miharu; Kreikemeyer, Bernd; Podbielski, Andreas; Okahashi, Nobuo; Hamada, Shigeyuki; Isoda, Ryutaro; Terao, Yutaka; Kawabata, Shigetada

2011-10-28

The human pathogen Streptococcus pyogenes produces diverse pili depending on the serotype. We investigated the assembly mechanism of FCT type 1 pili in a serotype M6 strain. The pili were found to be assembled from two precursor proteins, the backbone protein T6 and ancillary protein FctX, and anchored to the cell wall in a manner that requires both a housekeeping sortase enzyme (SrtA) and pilus-associated sortase enzyme (SrtB). SrtB is primarily required for efficient formation of the T6 and FctX complex and subsequent polymerization of T6, whereas proper anchoring of the pili to the cell wall is mainly mediated by SrtA. Because motifs essential for polymerization of pilus backbone proteins in other Gram-positive bacteria are not present in T6, we sought to identify the functional residues involved in this process. Our results showed that T6 encompasses the novel VAKS pilin motif conserved in streptococcal T6 homologues and that the lysine residue (Lys-175) within the motif and cell wall sorting signal of T6 are prerequisites for isopeptide linkage of T6 molecules. Because Lys-175 and the cell wall sorting signal of FctX are indispensable for substantial incorporation of FctX into the T6 pilus shaft, FctX is suggested to be located at the pilus tip, which was also implied by immunogold electron microscopy findings. Thus, the elaborate assembly of FCT type 1 pili is potentially organized by sortase-mediated cross-linking between sorting signals and the amino group of Lys-175 positioned in the VAKS motif of T6, thereby displaying T6 and FctX in a temporospatial manner.

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

PubMed

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.

Mitogenicity of M5 protein extracted from Streptococcus pyogenes cells is due to streptococcal pyrogenic exotoxin C and mitogenic factor MF.

PubMed Central

Schmidt, K H; Gerlach, D; Wollweber, L; Reichardt, W; Mann, K; Ozegowski, J H; Fleischer, B

1995-01-01

M proteins of Streptococcus pyogenes are virulence factors which impede phagocytosis, bind to many plasma proteins, and induce formation of cross-reactive autoimmune antibodies. Recently, it has been reported that some M proteins, extracted with pepsin from streptococci (pep M), are superantigens. One of these, pep M5, was investigated in detail and was shown to stimulate human T cells bearing V beta 2, V beta 4, and V beta 8. In the present study, we extracted and purified M5 protein by different biochemical methods from two M type 5 group A streptococcal strains. The crude extracts were fractionated by affinity chromatography and ion-exchange chromatography. All fractions were tested in parallel for M protein by immunoblotting and for T-cell-stimulating activity. Although several crude preparations of M5 protein were associated with mitogenicity for V beta 2 and V beta 8 T cells, the M5 proteins, irrespective of the extraction method, could be purified to the extent that they were no longer mitogenic. The mitogenic activity was not destroyed during the purification procedures but was found in fractions separated from M protein. In these fractions, streptococcal pyrogenic exotoxin C and mitogenic factor MF could be detected by protein blotting and enzyme-linked immunosorbent assay. Moreover, anti-M protein sera did not inhibit the mitogenic activity of crude extracts, but antisera which contained anti-streptococcal pyrogenic exotoxin C antibodies showed inhibition. The inability of M5 protein to stimulate T cells was confirmed with recombinant pep M5 produced in Escherichia coli. Our data strongly suggest that the mitogenic activity in M protein preparations is caused by traces of streptococcal superantigens different from M protein. PMID:7591107

THE THERAPEUTIC ACTIVITY OF PENICILLINS F, G, K, AND X IN EXPERIMENTAL INFECTIONS WITH PNEUMOCOCCUS TYPE I AND STREPTOCOCCUS PYOGENES

PubMed Central

Eagle, Harry

1947-01-01

1. The relative bactericidal activities of penicillins F, G, K, and X against Type I pneumococcus in vitro were 60, 100, 180, and 135. The corresponding activities against Streptococcus pyogenes, strain C-203, were 75, 100, 115, and 145, respectively. 2. The total curative doses (CD50) of penicillins F, G, K, and X in pneumococcal infections of white mice (ten injections at 3 hour intervals) were 4.6, 3.8, 20, and 2.4 mg. per kg., respectively, or relative activities of 83, 100, 19, and 160, referred to G as 100. 3. The corresponding curative doses in streptococcal infections of white mice were 2.6, 1.3, 14.0, and 0.5 mg. per kg., or relative activities of 50, 100, 9, and 260. 4. Penicillin K was therefore one-tenth as active in vivo as would be implied by its bactericidal activity in vitro. This probably reflects its rapid inactivation in vivo, evidenced by the low and evanescent blood levels observed in both rabbits and man, and the low urinary recovery of this species of penicillin. 5. Penicillin X was significantly more active therapeutically than its bactericidal activity in vitro would imply. This probably reflects its slower inactivation in vivo, evidenced by the somewhat higher and more prolonged blood levels afforded by this penicillin in comparison with penicillin G. Judged by the mouse infections with the strains here used, penicillin X is the penicillin of choice in the treatment of infections with pneumococcus Type I and hemolytic streptococci. 6. The curative dose of penicillin in streptococcal and pneumococcal infections paralleled the varying susceptibility of these organisms to penicillin in vitro. PMID:19871606

[Immunization and bacterial pathogens in the oropharynx as risk factors for alopecia areata].

PubMed

Morales-Sánchez, M A; Domínguez-Gómez, M A; Jurado-Santa Cruz, F; Peralta-Pedrero, M L

2010-06-01

Alopecia areata is an autoimmune inflammatory disease affecting the hair follicles. Researchers are currently interested in whether the presence of bacterial pathogens and/or a history of immunization can trigger an autoimmune response in patients who are genetically predisposed. This study aimed to determine whether there is an association between the development of alopecia areata and throat carriage of bacterial pathogens or a history of immunization. Sixty-five men and women with alopecia areata and 65 control patients with other skin diseases were studied at the Dr Ladislao de la Pascua Dermatology Clinic between September 2008 and February 2009. The patients ranged in age from 18-59 years. Patients with scalp diseases were excluded from the control group. In all cases, the patient was questioned about immunizations received in the previous 6 months, and a throat swab was cultured. A history of immunization (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.6-6.7; P=.001), the presence of bacterial pathogens in the oropharynx (OR, 2.6; 95% CI, 1.1-6.2; P=.033), and being a carrier of Streptococcus pyogenes (OR, 2.1; 95% CI, 1.7-2.5; P=.042) were risk factors for alopecia areata. Klebsiella pneumoniae, S. pyogenes, Pseudomonas aeruginosa, Streptococcus pneumoniae, Serratia marcescens and Escherichia coli were isolated from cultures. This is the first study to show an association between alopecia areata and throat carriage of bacterial pathogens or history of immunization, as risk factors for development of the disease. Given the characteristics of our study population, the association appears valid for patients with less than 25% hair loss and a course of disease under 1 year.

Development of primer sets for loop-mediated isothermal amplification that enables rapid and specific detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae

USDA-ARS?s Scientific Manuscript database

Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three ...

Cell-type-specific genome editing with a microRNA-responsive CRISPR–Cas9 switch

PubMed Central

Hirosawa, Moe; Fujita, Yoshihiko; Parr, Callum J. C.; Hayashi, Karin; Kashida, Shunnichi; Hotta, Akitsu; Woltjen, Knut

2017-01-01

Abstract The CRISPR–Cas9 system is a powerful genome-editing tool useful in a variety of biotechnology and biomedical applications. Here we developed a synthetic RNA-based, microRNA (miRNA)-responsive CRISPR–Cas9 system (miR-Cas9 switch) in which the genome editing activity of Cas9 can be modulated through endogenous miRNA signatures in mammalian cells. We created miR-Cas9 switches by using a miRNA-complementary sequence in the 5΄-UTR of mRNA encoding Streptococcus pyogenes Cas9. The miR-21-Cas9 or miR-302-Cas9 switches selectively and efficiently responded to miR-21-5p in HeLa cells or miR-302a-5p in human induced pluripotent stem cells, and post-transcriptionally attenuated the Cas9 activity only in the target cells. Moreover, the miR-Cas9 switches could differentially control the genome editing by sensing endogenous miRNA activities within a heterogeneous cell population. Our miR-Cas9 switch system provides a promising framework for cell-type selective genome editing and cell engineering based on intracellular miRNA information. PMID:28525578

rpoB Gene Sequence-Based Identification of Aerobic Gram-Positive Cocci of the Genera Streptococcus, Enterococcus, Gemella, Abiotrophia, and Granulicatella

PubMed Central

Drancourt, Michel; Roux, Véronique; Fournier, Pierre-Edouard; Raoult, Didier

2004-01-01

We developed a new molecular tool based on rpoB gene (encoding the beta subunit of RNA polymerase) sequencing to identify streptococci. We first sequenced the complete rpoB gene for Streptococcus anginosus, S. equinus, and Abiotrophia defectiva. Sequences were aligned with these of S. pyogenes, S. agalactiae, and S. pneumoniae available in GenBank. Using an in-house analysis program (SVARAP), we identified a 740-bp variable region surrounded by conserved, 20-bp zones and, by using these conserved zones as PCR primer targets, we amplified and sequenced this variable region in an additional 30 Streptococcus, Enterococcus, Gemella, Granulicatella, and Abiotrophia species. This region exhibited 71.2 to 99.3% interspecies homology. We therefore applied our identification system by PCR amplification and sequencing to a collection of 102 streptococci and 60 bacterial isolates belonging to other genera. Amplicons were obtained in streptococci and Bacillus cereus, and sequencing allowed us to make a correct identification of streptococci. Molecular signatures were determined for the discrimination of closely related species within the S. pneumoniae-S. oralis-S. mitis group and the S. agalactiae-S. difficile group. These signatures allowed us to design a S. pneumoniae-specific PCR and sequencing primer pair. PMID:14766807

Effect of Winemaking on the Composition of Red Wine as a Source of Polyphenols for Anti-Infective Biomaterials

PubMed Central

Di Lorenzo, Arianna; Bloise, Nora; Meneghini, Silvia; Sureda, Antoni; Tenore, Gian Carlo; Visai, Livia; Arciola, Carla Renata; Daglia, Maria

2016-01-01

Biomaterials releasing bactericides have currently become tools for thwarting medical device-associated infections. The ideal anti-infective biomaterial must counteract infection while safeguarding eukaryotic cell integrity. Red wine is a widely consumed beverage to which many biological properties are ascribed, including protective effects against oral infections and related bone (osteoarthritis, osteomyelitis, periprosthetic joint infections) and cardiovascular diseases. In this study, fifteen red wine samples derived from grapes native to the Oltrepò Pavese region (Italy), obtained from the winemaking processes of “Bonarda dell’Oltrepò Pavese” red wine, were analyzed alongside three samples obtained from marc pressing. Total polyphenol and monomeric anthocyanin contents were determined and metabolite profiling was conducted by means of a chromatographic analysis. Antibacterial activity of wine samples was evaluated against Streptococcus mutans, responsible for dental caries, Streptococcus salivarius, and Streptococcus pyogenes, two oral bacterial pathogens. Results highlighted the winemaking stages in which samples exhibit the highest content of polyphenols and the greatest antibacterial activity. Considering the global need for new weapons against bacterial infections and alternatives to conventional antibiotics, as well as the favorable bioactivities of polyphenols, results point to red wine as a source of antibacterial substances for developing new anti-infective biomaterials and coatings for biomedical devices. PMID:28773444

[Group A streptococcus-induced toxic shock syndrome in pregnancy: a case report of cesarean section].

PubMed

Yamada, Kumiko; Fukuda, Taeko; Kimura, Maiko; Hagiya, Keiichi; Danmura, Masato; Nakayama, Shin; Ogura, Tsuyoshi; Tanaka, Makoto

2012-12-01

Group A streptococcus (GAS)-induced toxic shock syndrome (TSS) in pregnancy is rare, but its clinical course is fulminant. The mortality rates of mother and fetus are reported to be 58 and 66%, respectively. We report a case of GAS-TSS after cesarean section. A 38-year-old pregnant woman of 38 weeks gestation was admitted to our hospital because of vomiting, fever of 39 degrees C, and continuous abdominal pain with scanty genital bleeding. She had complained of sore throat several days before. One hour after admission, external fetal monitoring revealed periodic pulse deceleration to 90 x beats min(-1). The emergent cesarean section was performed under general anesthesia. Approximately 8 hours after the cesarean section, she developed coma, shock and respiratory insufficiency requiring intubation. Streptococcus pyogens were isolated from her blood sample and the patient met criteria for GAS-TSS. She was treated with antibiotics (penicillin and clindamycin), antithrombin III, recomodulin, catecholamins, and continuous hemodialysis with filtration of toxins. Although the patient recovered and was discharged on 63rd day, the infant died on postpartum day 4. Early recognition and intensive treatment for GAS is recommended in a late stage pregnancy with an episode of sore throat, vomiting, high fever, strong labor pain, and DIC signs.

Disease Manifestations and Pathogenic Mechanisms of Group A Streptococcus

PubMed Central

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

2014-01-01

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

Study of streptococcal hemoprotein receptor (Shr) in iron acquisition and virulence of M1T1 group A streptococcus.

PubMed

Dahesh, Samira; Nizet, Victor; Cole, Jason N

2012-11-15

Streptococcus pyogenes (group A streptococcus, GAS) is a human bacterial pathogen of global significance, causing severe invasive diseases associated with serious morbidity and mortality. To survive within the host and establish an infection, GAS requires essential nutrients, including iron. The streptococcal hemoprotein receptor (Shr) is a surface-localized GAS protein that binds heme-containing proteins and extracellular matrix components. In this study, we employ targeted allelic exchange mutagenesis to investigate the role of Shr in the pathogenesis of the globally disseminated serotype M1T1 GAS. The shr mutant exhibited a growth defect in iron-restricted medium supplemented with ferric chloride, but no significant differences were observed in neutrophil survival, antimicrobial peptide resistance, cell surface charge, fibronectin-binding or adherence to human epithelial cells and keratinocytes, compared with wild-type. However, the shr mutant displayed a reduction in human blood proliferation, laminin-binding capacity and was attenuated for virulence in in vivo models of skin and systemic infection. We conclude that Shr augments GAS adherence to laminin, an important extracellular matrix attachment component. Furthermore, Shr-mediated iron uptake contributes to GAS growth in human blood, and is required for full virulence of serotype M1T1 GAS in mouse models of invasive disease.

Immunization with a streptococcal multiple-epitope recombinant protein protects mice against invasive group A streptococcal infection.

PubMed

Kuo, Chih-Feng; Tsao, Nina; Hsieh, I-Chen; Lin, Yee-Shin; Wu, Jiunn-Jong; Hung, Yu-Ting

2017-01-01

Streptococcus pyogenes (group A Streptococcus; GAS) causes clinical diseases, including pharyngitis, scarlet fever, impetigo, necrotizing fasciitis and streptococcal toxic shock syndrome. A number of group A streptococcus vaccine candidates have been developed, but only one 26-valent recombinant M protein vaccine has entered clinical trials. Differing from the design of a 26-valent recombinant M protein vaccine, we provide here a vaccination using the polyvalence epitope recombinant FSBM protein (rFSBM), which contains four different epitopes, including the fibronectin-binding repeats domain of streptococcal fibronectin binding protein Sfb1, the C-terminal immunogenic segment of streptolysin S, the C3-binding motif of streptococcal pyrogenic exotoxin B, and the C-terminal conserved segment of M protein. Vaccination with the rFSBM protein successfully prevented mortality and skin lesions caused by several emm strains of GAS infection. Anti-FSBM antibodies collected from the rFSBM-immunized mice were able to opsonize at least six emm strains and can neutralize the hemolytic activity of streptolysin S. Furthermore, the internalization of GAS into nonphagocytic cells is also reduced by anti-FSBM serum. These findings suggest that rFSBM can be applied as a vaccine candidate to prevent different emm strains of GAS infection.

Immunization with a streptococcal multiple-epitope recombinant protein protects mice against invasive group A streptococcal infection

PubMed Central

Kuo, Chih-Feng; Tsao, Nina; Hsieh, I-Chen; Lin, Yee-Shin; Wu, Jiunn-Jong; Hung, Yu-Ting

2017-01-01

Streptococcus pyogenes (group A Streptococcus; GAS) causes clinical diseases, including pharyngitis, scarlet fever, impetigo, necrotizing fasciitis and streptococcal toxic shock syndrome. A number of group A streptococcus vaccine candidates have been developed, but only one 26-valent recombinant M protein vaccine has entered clinical trials. Differing from the design of a 26-valent recombinant M protein vaccine, we provide here a vaccination using the polyvalence epitope recombinant FSBM protein (rFSBM), which contains four different epitopes, including the fibronectin-binding repeats domain of streptococcal fibronectin binding protein Sfb1, the C-terminal immunogenic segment of streptolysin S, the C3-binding motif of streptococcal pyrogenic exotoxin B, and the C-terminal conserved segment of M protein. Vaccination with the rFSBM protein successfully prevented mortality and skin lesions caused by several emm strains of GAS infection. Anti-FSBM antibodies collected from the rFSBM-immunized mice were able to opsonize at least six emm strains and can neutralize the hemolytic activity of streptolysin S. Furthermore, the internalization of GAS into nonphagocytic cells is also reduced by anti-FSBM serum. These findings suggest that rFSBM can be applied as a vaccine candidate to prevent different emm strains of GAS infection. PMID:28355251

Replacing and Additive Horizontal Gene Transfer in Streptococcus

PubMed Central

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

2012-01-01

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

Streptococcal pharyngitis and rheumatic heart disease: the superantigen hypothesis revisited.

PubMed

Hurst, Jacklyn R; Kasper, Katherine J; Sule, Akshay N; McCormick, John K

2018-07-01

Streptococcus pyogenes is a human-specific and globally prominent bacterial pathogen that despite causing numerous human infections, this bacterium is normally found in an asymptomatic carrier state. This review provides an overview of both bacterial and human factors that likely play an important role in nasopharyngeal colonization and pharyngitis, as well as the development of acute rheumatic fever and rheumatic heart disease. Here we highlight a recently described role for bacterial superantigens in promoting acute nasopharyngeal infection, and discuss how these immune system activating toxins could be crucial to initiate the autoimmune process in rheumatic heart disease. Copyright © 2018. Published by Elsevier B.V.

Chickenpox complicated by pneumococcal meningitis: a rare coinfection.

PubMed

Rebahi, H; Mouaffak, Y; Soraa, N; Younous, S

2014-11-01

Bacterial complications, particularly skin superinfections, are common during chickenpox. However, reports of acute bacterial meningitis associated with chickenpox are unusual and amount to only a very few observations. For the most part, they are caused by Neisseria meningitidis or Streptococcus pyogenes. We report an infrequent occurrence of pneumococcal meningitis 2 days after the onset of a chickenpox rash in a 7-year-old previously healthy boy. Based on data from the literature, we attempt to understand the possible mechanisms resulting in bacterial complications, particularly meningitis, during chickenpox and to determine the means to prevent it. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Multifocal necrotising fasciitis and septic shock complicating varicella infection in an adult

PubMed Central

Mifsud, Simon; Schembri, Emma Louise; Mallia Azzopardi, Charles; Zammit, Maria Alessandra

2013-01-01

A 35-year-old woman with a 3-day history of chickenpox, presented to the hospital in septic shock and with multifocal, non-adjacent lesions of necrotising fasciitis. Necrotising fasciitis is a rare yet life-threatening complication of chickenpox. Blood cultures and wound swabs confirmed the presence of Streptococcus pyogenes. The initial emergency management included oxygen, aggressive fluid resuscitation and antimicrobial therapy. Once the patient was stabilised, surgical management ensued. This included debridement and eventual grafting of the necrotic skin lesions. Intensive management and follow-up for 8 weeks were required before the patient was deemed fit for discharge. PMID:24130210

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

PubMed

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

2004-01-01

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

Antimicrobial and healing activity of kefir and kefiran extract.

PubMed

Rodrigues, Kamila Leite; Caputo, Lucélia Rita Gaudino; Carvalho, Jose Carlos Tavares; Evangelista, João; Schneedorf, Jose Maurício

2005-05-01

Kefir and its insoluble polysaccharide, kefiran, were both tested for antimicrobial and cicatrizing activities against several bacterial species and Candida albicans using an agar diffusion method. Comparator antimicrobials were also tested. Cicatrizing experiments were carried out on Wistar rats with induced skin lesions and Staphylococcus aureus inoculation, using a topical application of a 70% kefir gel. Both kefir and kefiran showed some activity against all organisms tested; the highest activity was against Streptococcus pyogenes. Cicatrizing experiments using 70% kefir gel had a protective effect on skin connective tissue and 7 days treatment enhanced wound healing compared with 5 mg/kg of neomycin-clostebol emulsion.

[Unsuccessful treatment with OK-432 picibanil for orbital lymphangioma].

PubMed

Lanuza García, A; Bañón Navarro, R; Llorca Cardeñosa, A; Delgado Navarro, C

2012-01-01

Lymphangioma is a malformation of the lymphatic system. The classic approach is surgery. We report a case of orbital lymphangioma in a girl who was given OK-432 to avoid surgery and its complications. OK-432 is a lyophilized mixture of group A Streptococcus pyogenes which produces a fibrosis limited to the lesion with a high cure rate. The main advantages are the easy intra-lesional application. with no scars and or damage of closed areas. Its main disadvantage is a significant local inflammatory reaction. Copyright © 2011 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

[Effect of medicinal plant extracts on the growth of microorganisms].

PubMed

Baronets, N G; Adlova, G P; Mel'nikova, V A

2001-01-01

Extracts obtained from sweatweed and licorice roots, flax seeds, milfoil, bur-marigold, plantain, coltsfoot, nettle, Indian corn stigmas, laminaria produced a stimulating effect on the growth of Candida albicans test strain and Streptococcus pyogenes test strain Dick 1. Sweatweed, licorice, Aerva lanata and violet extracts influenced the growth of Corynebacterium xerosis 1911, while sweatweed, violet, horse-tail, bur-marigold, camomile, plantain, and nettle extracts influenced the growth of shigellae. The stimulating effect could be supposedly produced by biologically active substances contained in medicinal plants (organic acids, alkaloids, carotinoids, vitamins, microelements). Further studies aimed at the identification of substances producing the stimulating effect are planned.

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

PubMed Central

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

2013-01-01

Streptococcus canis is an animal pathogen that occasionally causes human infections. Isolates recovered from infections of animals (n = 78, recovered from 2000 to 2010 in three European countries, mainly from house pets) and humans (n = 7, recovered from 2006 to 2010 in Portugal) were identified by phenotypic and genotypic methods and characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and emm typing. S. canis isolates presented considerable variability in biochemical profiles and 16S rRNA. Resistance to antimicrobial agents was low, with the most significant being tet(M)- and tet(O)-mediated tetracycline resistance. MLST analysis revealed a polyclonal structure of the S. canis population causing infections, where the same genetic lineages were found infecting house pets and humans and were disseminated in distinct geographic locations. Phylogenetic analysis indicated that S. canis was a divergent taxon of the sister species Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis and found evidence of acquisition of genetic material by S. canis from S. dysgalactiae subsp. equisimilis. PFGE confirmed the MLST findings, further strengthening the similarity between animal and human isolates. The presence of emm-like genes was restricted to a few isolates and correlated with some MLST-based genetic lineages, but none of the human isolates could be emm typed. Our data show that S. canis isolates recovered from house pets and humans constitute a single population and demonstrate that isolates belonging to the main genetic lineages identified have the ability to infect the human host, providing strong evidence for the zoonotic nature of S. canis infection. PMID:23345291

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

PubMed

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

2013-04-01

Streptococcus canis is an animal pathogen that occasionally causes human infections. Isolates recovered from infections of animals (n = 78, recovered from 2000 to 2010 in three European countries, mainly from house pets) and humans (n = 7, recovered from 2006 to 2010 in Portugal) were identified by phenotypic and genotypic methods and characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and emm typing. S. canis isolates presented considerable variability in biochemical profiles and 16S rRNA. Resistance to antimicrobial agents was low, with the most significant being tet(M)- and tet(O)-mediated tetracycline resistance. MLST analysis revealed a polyclonal structure of the S. canis population causing infections, where the same genetic lineages were found infecting house pets and humans and were disseminated in distinct geographic locations. Phylogenetic analysis indicated that S. canis was a divergent taxon of the sister species Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis and found evidence of acquisition of genetic material by S. canis from S. dysgalactiae subsp. equisimilis. PFGE confirmed the MLST findings, further strengthening the similarity between animal and human isolates. The presence of emm-like genes was restricted to a few isolates and correlated with some MLST-based genetic lineages, but none of the human isolates could be emm typed. Our data show that S. canis isolates recovered from house pets and humans constitute a single population and demonstrate that isolates belonging to the main genetic lineages identified have the ability to infect the human host, providing strong evidence for the zoonotic nature of S. canis infection.

A quantitative model for dermal infection and oedema in BALB/c mice pinna.

PubMed

Marino-Marmolejo, Erika Nahomy; Flores-Hernández, Flor Yohana; Flores-Valdez, Mario Alberto; García-Morales, Luis Felipe; González-Villegas, Ana Cecilia; Bravo-Madrigal, Jorge

2016-12-12

Pharmaceutical industry demands innovation for developing new molecules to improve effectiveness and safety of therapeutic medicines. Preclinical assays are the first tests performed to evaluate new therapeutic molecules using animal models. Currently, there are several models for evaluation of treatments, for dermal oedema or infection. However, the most common or usual way is to induce the inflammation with chemical substances instead of infectious agents. On the other hand, this kind of models require the implementation of histological techniques and the interpretation of pathologies to verify the effectiveness of the therapy under assessment. This work was focused on developing a quantitative model of infection and oedema in mouse pinna. The infection was achieved with a strain of Streptococcus pyogenes that was inoculated in an injury induced at the auricle of BALB/c mice, the induced oedema was recorded by measuring the ear thickness with a digital micrometer and histopathological analysis was performed to verify the damage. The presence of S. pyogenes at the infection site was determined every day by culture. Our results showed that S. pyogenes can infect the mouse pinna and that it can be recovered at least for up to 4 days from the infected site; we also found that S. pyogenes can induce a bigger oedema than the PBS-treated control for at least 7 days; our results were validated with an antibacterial and anti-inflammatory formulation made with ciprofloxacin and hydrocortisone. The model we developed led us to emulate a dermal infection and allowed us to objectively evaluate the increase or decrease of the oedema by measuring the thickness of the ear pinna, and to determine the presence of the pathogen in the infection site. We consider that the model could be useful for assessment of new anti-inflammatory or antibacterial therapies for dermal infections.

MALDI-TOF mass spectrometry for differentiation between Streptococcus pneumoniae and Streptococcus pseudopneumoniae.

PubMed

van Prehn, Joffrey; van Veen, Suzanne Q; Schelfaut, Jacqueline J G; Wessels, Els

2016-05-01

We compared the Vitek MS and Microflex MALDI-TOF mass spectrometry platform for species differentiation within the Streptococcus mitis group with PCR assays targeted at lytA, Spn9802, and recA as reference standard. The Vitek MS correctly identified 10/11 Streptococcus pneumoniae, 13/13 Streptococcus pseudopneumoniae, and 12/13 S. mitis/oralis. The Microflex correctly identified 9/11 S. pneumoniae, 0/13 S. pseudopneumoniae, and 13/13 S. mitis/oralis. MALDI-TOF is a powerful tool for species determination within the mitis group. Diagnostic accuracy varies depending on platform and database used. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.