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High Diversity of Group A Streptococcal emm Types in an Indian Community: The Need to Tailor Multivalent Vaccines.
- Source :
-
Clinical Infectious Diseases . 1/1/2005, Vol. 40 Issue 1, p46-51. 6p. - Publication Year :
- 2005
-
Abstract
- Background. Concern about the emergence of antibiotic-resistant strains and about morbidity and/or mortality related to rheumatic fever and rheumatic heart disease has been a continuous impetus for the development of a safe, effective vaccine against group A Streptococcus (GAS). To date, >120 GAS M types are known, as identified by serological typing. in general, serum immunoglobulin G directed to the hypervariable NH2 terminal portion of M protein leads to complement fixation and opsonophagocytosis of the homologous streptococcal serotype by polymorphonuclear leukocytes, and the protection is type specific. The sequence variation at the N terminus ultimately affects the binding of opsonic antibodies. Because of hypervariability in these opsonic sequences from different M types, it was relevant to use epitopes derived from these multiple sequences in a "multivalent vaccine" design for evaluation of protection against these M types of GAS. Thus, any attempts to design vaccines for a given community will require information on N terminal-sequence typing and variation. Methods. in the present study, we performed molecular characterization of isolates recovered from patients in northern india-to our knowledge, for the first time-in an attempt to study the circulating M types and their N terminal sequence variability. Results. We report tremendous diversity in GAS strains recovered from symptomatic patients, with implications on the design of appropriate vaccines. Fifty-nine isolates represented 33 different sequence types. Very few novel types and no predominant clones were found. Conclusions. The high diversity of emm types encountered in a single year suggests that any M protein-based multivalent vaccine would have to be specifically tailored for this region. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10584838
- Volume :
- 40
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Clinical Infectious Diseases
- Publication Type :
- Academic Journal
- Accession number :
- 15330194
- Full Text :
- https://doi.org/10.1086/426443