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ABSTRACT: 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 (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.
Letters in Applied Microbiology 06/2004; 39(1):84 - 88. · 1.62 Impact Factor
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ABSTRACT: To monitor molecular heterogeneity among the clinical isolates of group A Streptococcus (GAS) from north India by Vir and emm typing.
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.
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.
Letters in Applied Microbiology 02/2004; 39(1):84-8. · 1.62 Impact Factor
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ABSTRACT: 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.
Letters in Applied Microbiology 08/2002; 35(3):237 - 241. · 1.62 Impact Factor
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ABSTRACT: To monitor the presence of various pyrogenic exotoxin genes in strains of Streptococcus pyogenes isolated in India.
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.
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.
Letters in Applied Microbiology 01/2002; 35(3):237-41. · 1.62 Impact Factor
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ABSTRACT: To estimate the incidence and risk factors of group A streptococcus (GAS) sore throat among school-aged children living in a periurban slum area of Chandigarh, North India.
A total of 536 children aged 5-15 years from 261 families identified by a systematic random selection method were enrolled in the study. Episodes of sore throat were recorded through fortnightly home visits over a one-year period. The local vernacular (Hindi) terms gala kharab (bad throat) and khansi jukam (cough and cold) were used to identify symptoms of sore throat, and throat swab specimens were collected from children who had these symptoms on the day of the home visit. Bacterial culture was carried out and the isolation of GAS was confirmed using group-A-specific antiserum.
The incidences of sore throat and GAS sore throat were, respectively, 7.05 and 0.95 episodes per child-year. The incidence was higher in the following situations: among 11-year-olds, during the winter (November to January) and rainy (August) months (a bimodal peak), among children living in houses where there was no separate room for the kitchen, and in homes that included a tobacco smoker.
The results show that the incidence of GAS sore throat was related to age, season, and indoor air pollution.
Bulletin of the World Health Organisation 02/2001; 79(6):528-33. · 4.64 Impact Factor
