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V . S A G A R , D . K . B A K S H I , S . N A N D I , N . K . G A N G U L Y , R . K U M A R A N D A . C H A K R A B O R T I . 2004. Aim: To monitor molecular heterogeneity among the clinical isolates of group A Streptococcus (GAS) from north India by Vir and emm typing. Methods and 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 (7AE5%), which revealed different Vir types within same emm type. The most prevalent emm type found was emm 49 (15%) followed by 7AE5% 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 57AE5% 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.

Aim: To monitor the presence of various pyrogenic exotoxin genes in strains of Streptococcus pyogenes isolated in India. Methods & Results: Isolates recovered from pharyngitis (52) and rheumatic fever (RF)/ rheumatic heart disease (RHD) (8) patients were analysed for the presence of toxin genes, speA, speB and speF, by PCR. The specificity of the products was confirmed by restriction enzyme digestion and Southern hybridization. Among the 60 isolates studied, the incidence of speA, speB and speF were 5(8.3%), 56(93.3%) and 53(88.3%), respectively. The expression of these genes was established in representative isolates by RT-PCR. Conclusions: Comparative analysis of frequency of the speA, speB and speF genes, among pharyngitis and RF/RHD associated isolates, showed higher incidence in RF/RHD (25%, 100%,100%) as compared to pharyngitis patients (5.8%, 92.3%, 86.5%), respectively. Significance of Study: The presence of the speA gene, which is usually associated with scarlet fever or toxic shock-like syndrome, within few Indian isolates may be indicative of new virulent strains circulating within the Indian community. High distribution of toxin genes among RF/RHD compared to pharyngitis isolates indicate their possible role in increased virulence.

Heterogeneity exists among Group a Streptococcus emm types worldwide. In 2003, we observed 11 circulating emm types in northern region of India, of which emm 81 was found to be the predominant type (17.5%). As emm 81 has been reported to be associated with invasive diseases in western countries, hence, in the present study, attempts were made to study the virulence potential of these isolates from skin and throat samples. Isolates were screened for nine fi bronectin binding protein (FBP) genes, evaluated for adherence & invasion potential along with drug resistance to various commonly prescribed antibiotics for treatment. Throat isolates showed higher distribution of FBP genes as compared to skin isolates. All the isolates were found to be positive for sciB and prtF15; 92.9% for sfb and fba, 78.6% for sciA; 35.2% for prtF1; 7.1% for prtF2 but none for sfb2 and pfbp. Isolates showed low (8.5%) to moderate (27.7%) adherence and negligible invasion potential in the experimental A549 cell line which was con firmed by immuno fluorescent confocal microscopy. Drug resistance pro fi ling showed isolates to be highly resistant to macrolides, tetracycline, co-trimaxazole but all susceptible to penicillin. The study shows emm 81 strains from northern India to be of less virulent nature with respect to adherence/invasion potential, highlighting that same emm type in different geographical regions may have a different clinical outcome, the latter being dependent on number of factors like ethnicity, geographical, socioeconomic factors besides its molecular type and source.