ZMPB ALLELIC VARIATION IN STREPTOCOCCUS PNEUMONIAE ISOLATES CAUSING MENINGITIS IN INDIAN POPULATION
Streptococcus pneumoniae is a leading cause of meningitis. Intense inflammatory response observed in meningitis is partially attributed to zinc metalloprotease encoded by zmpB in pneumococcal strains. We aimed to study allelic variations of zmpB among isolates obtained from Meningitis patients
36 cerebrospinal fluid (CSF) isolates collected across the country from 2009-2016 were sequenced on Illumina platform. The CRL in-house bioinformatics pipeline was used to extract gene sequences, alignment and phylogeny analysis. SeroBA was used to determine serotype. Allelic variations of zmpB gene was analyzed by comparing the identity with the virulent strain S. pneumoniae TIGR4.
36 pneumococcal isolates belong to 24 serotypes with 19F(n=5) as dominant type. Non-PCV13 vaccine serotypes constituted 50% of the isolates(n=18). The isolates were assigned to 28 sequence clusters, among them GPSC10(n=4) & GPSC2(n=3) were predominant.32 of 36 isolates showed 21 to 88% of sequence variation, while remaining 4 isolates showed sequence similarity of 98% with the TIGR4. Allelic variations did not affect the protein coding region analysis and conserved domains of ZmpB protein was identified in all isolates.
The findings provide insight on the allelic variations of zmpB, indicating there is a high degree of polymorphism in the sequence of zmpB in pneumococci causing meningitis.