<i>emm</i>and C-Repeat Region Molecular Typing of Beta-Hemolytic Streptococci in a Tropical Country: Implications for Vaccine Development

Steer, Andrew C.; Magor, Graham; Jenney, Adam; Kado, Joseph; Good, Michael F.; McMillan, David; Batzloff, Michael R.; Carapetis, Jonathan R.

doi:10.1128/jcm.00312-09

Cited by 53 publications

(45 citation statements)

References 47 publications

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“…Although it appears from the present study that there is more diversity in emm types than previously reported, our findings are much less diverse than data from other countries, such as the United States (56 emm types), Bali (70 emm types), Fiji (52 emm types), and Ethiopia (76 emm types) (24)(25)(26)(27). In a recent study from Spain, 29 emm types and 45 emm subtypes were recognized (28).…”

Section: Discussioncontrasting

confidence: 55%

Streptococcus pyogenes emm Types and Clusters during a 7-Year Period (2007 to 2013) in Pharyngeal and Nonpharyngeal Pediatric Isolates

et al. 2015

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Group A streptococcus (GAS) is an important cause of morbidity and mortality worldwide. Surveillance of emm types has important implications, as it can provide baseline information for possible implementation of vaccination. A total of 1,349 GAS pediatric isolates were collected during a 7-year period (2007 to 2013); emm typing was completed for 1,282 pharyngeal (84%) or nonpharyngeal (16%) isolates, and emm clusters and temporal changes were analyzed. Thirty-five different emm types, including 14 subtypes, were identified. The most prevalent emm types identified were 1 (16.7%), 12 (13.6%), 77 (10.9%), 4 (10.8%), 28 (10.4%), 6 (6.8%), 3 (6.6%), and 89 (6.6%), accounting for 82.3% of total isolates. Rheumatogenic emm types comprised 16.3% of total isolates. The emm types 12, 4, and 77 were more prevalent among pharyngeal isolates, and the emm types 1, 89, 6, 75, and 11 were more prevalent among nonpharyngeal isolates. The emm types identified belonged to 13 emm clusters, and the 8 most prevalent clusters comprised 97% of all isolates. There were statistically significant decreases in the prevalence of emm types 12, 4, 5, and 61 and increases in the prevalence of emm types 89, 75, and 11, compared with the period 2001 to 2006. The proposed 30-valent GAS vaccine, which is currently in preclinical studies, encompasses 97.2% of the emm types detected in our study and 97.4% of the erythromycin-resistant strains. In addition, it includes 93.3% of the emm types involved in bacteremia. A much greater diversity of GAS emm types was identified in our area than described previously. Seasonal fluctuations and the introduction of new emm types were observed. Continuous surveillance of emm types is needed in order to evaluate the possible benefits of an M protein-based GAS vaccine. Streptococcus pyogenes (group A streptococcus [GAS]) is an important cause of morbidity and mortality worldwide (1). GAS causes a broad spectrum of diseases, ranging from mild to lifethreatening invasive infections. GAS infections can also lead to immune-mediated sequelae such as rheumatic fever and glomerulonephritis, with long-term complications (2, 3).In order to yield such a diversity of clinical manifestations, GAS possesses a large number of virulence mechanisms, with a high degree of variability in virulence determinants among different GAS serotypes (4, 5). The cell wall-associated M protein, encoded by the emm gene, is a major antigenic epitope and virulence factor of GAS and forms the basis for the serotyping of GAS isolates (6). The M protein acts as an epithelial adhesion factor, inhibits phagocytosis, and allows the organism to overcome innate immune responses (7,8). The N terminus consists of a highly variable amino acid sequence, resulting in antigenic diversity, and is the basis for a nucleotide-based emm-typing scheme (9). There are at least 220 different emm types and subtypes of GAS, and new types are still being identified (8,10,11). Temporal, geographic, and seasonal variations in the dominant strains are well described and can ...

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Section: Discussioncontrasting

confidence: 55%

Streptococcus pyogenes emm Types and Clusters during a 7-Year Period (2007 to 2013) in Pharyngeal and Nonpharyngeal Pediatric Isolates

et al. 2015

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“…The variable nucleotide sequence encoding the N-terminal region of the M protein is not only the antigenic target for developing GAS vaccines (17)(18)(19) but also the basis for the sequence-based emm typing method (20). emm typing is the most widely used molecular typing approach, and more than 200 different emm types have been reported worldwide (21)(22)(23).…”

mentioning

confidence: 99%

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

et al. 2016

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g 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. S treptococcus pyogenes (group A streptococcus [GAS]) is an important Gram-positive human pathogen, which is responsible for more than 500,000 deaths per year (1). Although there is no vaccine available, several vaccine candidates, especially M proteinbased vaccines, are currently in development (2-5). M protein is a bacterial surface protein and has important roles in GAS pathogenesis (6, 7). These include binding to human fibrinogen, complement regulatory proteins, and immunoglobulins; contributing to resistance to phagocytic cell clearance; and inducing vascular leakage during infection (8-15). M protein-based vaccines are constructed from the hypervariable N-terminal region (26-and 30-valent vaccine) or the conserved C-terminal proportion (J8 vaccine and StreptInCor) of the M protein and were all proven to be effective against GAS infection in animal models (2, 3, 5). In addition, phase I trials with the 30-valent and J8 vaccines are under way in North America and Australia, respectively (16).The variable nucleotide sequence encoding the N-terminal region of the M protein is not only the antigenic target for developing GAS vaccines (17-19) but also the basis for the sequence-based emm typing method (20). emm typing is the most widely used molecular typing approach, and more than 200 different emm types have been reported worldwide (21-23). However, since emm typing is based on a small portion of the emm gene, this typing method provides limited information about the predicted conformational structure or functional domains of the M protein (24). emm pattern typing is another typing method that is based on the presence and arrangement of emm and emm-like genes in the GAS genome (25). emm pattern typing has...

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“…The Results of both IFA and FACS ( Table 1) confirmed binding of JJo specific antibodies to the surface of GAS cells of diverse M types. All GAS strains typically contained within their last C-terminal repeat M-specific sequences corresponding to either J14 or J14.1 [18]. Anti-J14 antisera cross react with J14 and J14.1 and vice versa [19].…”

Section: Binding Characteristics Of Jjo Antibodies To Gas Isolatesmentioning

confidence: 99%

JJo, a Recombinant Dimer of Conformationally Restricted Peptide Elicits Protective Response against Group A Streptococcus (GAS) Isolates from a GAS-Endemic Region

Sunagar¹,

Ramachandran²,

Georgousakis³

et al. 2011

WJV

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emmand C-Repeat Region Molecular Typing of Beta-Hemolytic Streptococci in a Tropical Country: Implications for Vaccine Development

Cited by 53 publications

References 47 publications

Streptococcus pyogenes emm Types and Clusters during a 7-Year Period (2007 to 2013) in Pharyngeal and Nonpharyngeal Pediatric Isolates

Streptococcus pyogenes emm Types and Clusters during a 7-Year Period (2007 to 2013) in Pharyngeal and Nonpharyngeal Pediatric Isolates

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

JJo, a Recombinant Dimer of Conformationally Restricted Peptide Elicits Protective Response against Group A Streptococcus (GAS) Isolates from a GAS-Endemic Region

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