Molecular heterogeneity among north Indian isolates of Group A Streptococcus.
OBJECTIVE
To monitor molecular heterogeneity among the clinical isolates of group A Streptococcus (GAS) from north India by Vir and emm typing.


RESULTS
GAS isolates, 31 from pharyngitis and nine from rheumatic fever (RF)/rheumatic heart disease (RHD) patients were differentiated into 16 Vir types (VT). These isolates were further discriminated into 23 emm types. Most of emm types were Vir type specific, except few (7.5%), which revealed different Vir types within same emm type. The most prevalent emm type found was emm 49 (15%) followed by 7.5% of emm 69, emm 71 and emm 75 which were different from emm type distribution reported from south India.


CONCLUSIONS
Analysis of data revealed 40% heterogeneity by Vir typing and 57.5% by emm typing among GAS isolates which is significant in view of small number of isolates studied. SIGNIFICANCE OF IMPACT OF THE STUDY: The molecular study for the first time demonstrates different emm types prevalent and circulating in northern region of India and such data may help in selection of types for vaccine development.
Sagar
V
V
Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Bakshi
D K
DK
Nandi
S
S
Ganguly
N K
NK
Kumar
R
R
Chakraborti
A
A
D000293:Adolescent; D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D002352:Carrier Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D014644:Genetic Variation; D006801:Humans; D007194:India / Q000453:epidemiology; D010612:Pharyngitis / Q000453:epidemiology / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D018085:Regulon; D012213:Rheumatic Fever / Q000453:epidemiology / Q000382:microbiology*; D012214:Rheumatic Heart Disease / Q000453:epidemiology / Q000382:microbiology*; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein