Immune response against M protein-conserved region peptides from prevalent group A Streptococcus in a North Indian population

BackgroundGroup A streptococci (GAS) cause infections with a high prevalence in most developing countries. A GAS vaccine under trial that is based on the amino-terminus of the M protein provides type-specific immunity, and hence seems ineffective in India because of heterogeneous emm types. However, the conserved C-terminal region of the M protein protects against multiple serotypes. In this paper, the immune response generated against the conserved C-repeat region of the M protein was checked in an Indian population to establish their vaccine candidature.MethodsWhen screened for GAS, patients with pharyngitis, rheumatic fever/rheumatic heart disease (RF/RHD), and invasive disease showed heterogeneous emm types, out of which five prevalent types (1-2, 11, 49, 75 and 112) were selected for the study. The C-terminal region of their M proteins showed conserved C1-, C2-, and C3-repeats. The C1-repeat was more diverse and had two different J14-like sequences. Peptides to these C-terminal regions (J14.1 and J14-R6) were designed. Antibodies against these peptides were analyzed using the sera of 130 GAS-infected volunteers.ResultsSerum antibodies were significantly higher in patients with acute rheumatic fever, RHD, and invasive disease than in patients with pharyngitis or the healthy controls. The serum antibodies to these peptides was higher in teenagers and adults than in children.ConclusionResults showed an association between streptococcal disease progression and the age-related development of immunity to the conserved regions. Hence, these peptides could be considered protective in impeding streptococcal infections worldwide

Nuclear and Chloroplast DNA Variation Provides Insights into Population Structure and Multiple Origin of Native Aromatic Rices of Odisha, India

<div><p>A large number of short grain aromatic rice suited to the agro-climatic conditions and local preferences are grown in niche areas of different parts of India and their diversity is evolved over centuries as a result of selection by traditional farmers. Systematic characterization of these specialty rices has not been attempted. An effort was made to characterize 126 aromatic short grain rice landraces, collected from 19 different districts in the State of Odisha, from eastern India. High level of variation for grain quality and agronomic traits among these aromatic rices was observed and genotypes having desirable phenotypic traits like erect flag leaf, thick culm, compact and dense panicles, short plant stature, early duration, superior yield and grain quality traits were identified. A total of 24 SSR markers corresponding to the hyper variable regions of rice chromosomes were used to understand the genetic diversity and to establish the genetic relationship among the aromatic short grain rice landraces at nuclear genome level. SSR analysis of 126 genotypes from Odisha and 10 genotypes from other states revealed 110 alleles with an average of 4.583 and the Nei’s genetic diversity value (<i>He</i>) was in the range of 0.034–0.880 revealing two sub-populations SP 1 (membership percentage-27.1%) and SP 2 (72.9%). At the organelle genomic level for the C/A repeats in PS1D sequence of chloroplasts, eight different plastid sub types and 33 haplotypes were detected. The <i>japonica</i> (Nipponbare) subtype (6C7A) was detected in 100 genotypes followed by <i>O</i>. <i>rufipogon</i> (KF428978) subtype (6C6A) in 13 genotypes while <i>indica</i> (93–11) sub type (8C8A) was seen in 14 genotypes. The tree constructed based on haplotypes suggests that short grain aromatic landraces might have independent origin of these plastid subtypes. Notably a wide range of diversity was observed among these landraces cultivated in different parts confined to the State of Odisha.</p></div

Analysis of molecular variance of short grain aromatic rices based on SSR marker data (district wise).

<p>Analysis of molecular variance of short grain aromatic rices based on SSR marker data (district wise).</p

Haplotype tree depicting different haplotypes among the short grain aromatic rices based on nucleotide polymorphism of the PS1D region.

<p>Haplotype tree depicting different haplotypes among the short grain aromatic rices based on nucleotide polymorphism of the PS1D region.</p

Distribution of duration and amylose content in short grain aromatic rice genotypes collected from 19 districts.

<p>Note: Numbers in the x-axis represent 19 different districts [Anugul (1), Balasore (2), Bolangir (3), Cuttack (4), Deogarh (5), Dhenkanal (6), Ganjam (7), Jajpur (8), Kalahandi (9), Kendrapara (10), Kenojhar (11), Koraput (12), Malkangiri (13), Mayurbhanj (14), Nayagarh (15), Kandhamal (16), Puri (17), Sambalpur (18) and Sundargarh (19)].</p

Genetic diversity parameters calculated on SSR data.

<p>Genetic diversity parameters calculated on SSR data.</p

Variability for different agronomic and grain quality traits in short grain aromatic rices.

<p>Variability for different agronomic and grain quality traits in short grain aromatic rices.</p

Unrooted neighbour-joining tree showing genetic relationship of short aromatic grain rices (based on SSR marker data) among 19 geographical districts.

<p>Unrooted neighbour-joining tree showing genetic relationship of short aromatic grain rices (based on SSR marker data) among 19 geographical districts.</p

Genetic relationships and population structure of short grain aromatic rices.

<p>A: NJ dendrogram; B: Principal Co-ordinate analysis; C: Population Structure.</p