Poster Presentation 20th Lancefield International Symposium on Streptococci and Streptococcal Diseases 2017

Distribution of collagen binding PARF Motifs in M Proteins of Group A, C and G Streptococcal Strains from North India (#168)

Vivek Sagar 1 , Anuradha Chakraborti 1 , D P Nitsche-Schmitz 2 , Yash P Sharma 1 , Pallab Ray 1 , Gursharan S Chhatwal 2 , Rajesh Kumar 1
  1. Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
  2. Helmholtz Centre for Infection Research, Braunschweig, Germany

Streptococcal strains, upon binding to host collagen form auto-antigen complex which generates anti-collagen antibodies, lead to development of RF/RHD. PARF(Peptide Associated with Rheumatic Fever) motif of M proteins helps strains to bind collagen. It is hypothesized that streptococci having PARF(AEYLKALN) may have higher tendency to cause RF/RHD. Besides GAS, there are indications that GCS/GGS strains may also cause RF/RHD. Therefore distribution of PARF was explored in GAS, GCS/GGS strains and level of anti-collagen antibodies was also estimated in patient sera.

Strains were isolated from children of age group 5-15 years in school health survey. Serum samples were collected from GAS positive, RF/RHD  patients. emm  typing and identification of PARF was done by emm gene sequencing. Anti-collagen IV antibodies were estimated by ELISA.

Out of 5000 children examined, 201 isolates(43GAS, 33GCS, 125GGS) were collected. From 990(19.8%) pharyngitis cases, 9(0.90%) were GAS, 3(0.3%) were GCS and 22(3.4%) were GGS positive. Out of 158 GCS/GGS isolates, 57 belonged to emm gene positive dysgalactiae group. Out of 100, 93 strains (37GAS,56GCS/GGS) were further characterized. From 37 GAS, belonging to 23 types(most prevalent: emm100, emm85, emm71), none of isolate was PARF positive. Among 56 GCS/GGS strains(most prevalent: stG245, stG653), PARF was identified from only two GGS(stG10.0) strains. PARF like motifs were identified from 20 GAS and 20 GCS/GGS strains. Anti-collagen IV antibodies were high in GAS positive(6), RF(8), RHD(14) samples in comparison to healthy controls(10).

PARF is rare in North Indian streptococcal strains but high level of anti-collagen antibodies in patient’s sera was observed.