Genomic evolution of S.pneumoniae CC63 in India.. Streptococcus pneumoniae CC63 in India

Serotype 14 is one of the major serotype associated with penicillin non susceptibility which was highly prevalent in carriage as well as IPD worldwide during the pre-vaccine era. Though, the serotype 14 associated IPD infections has decreased in the PCV introduced countries it is still the major serotype in South East Asian countries, especially in India. Serotype 14 is associated with high invasive disease potential leading to complicated HUS and necrotizing pneumonia. It also possess many virulence gens and macrolide resistance associated mobile genetic elements. Earlier International PMEN clones reported with serotype 14 are ST18, 9, 20, 67, 230 and 124. Currently majority of st14 is associated with CC63 (Africa & Asia) while PMEN clone ST63 was first reported from Sweden with serotype15A. The shift to CC63st14 is not identified. In India, CC63st14 is most common associated with IPD,PNSP and MDR (resistance to antibiotics such as; penicillin, erythromycin, ceftriaxone and Co-trimoxazole) with limited or a little data on carriage isolates. CC63st15A is the most prevalent penicillin- and meropenem-resistant clones associated with IPD in Taiwan seen during post PCV. CC63 belong to GPSC9 which is one among the ten most prevalent GPSCs causing non-VT IPD in the PCV13 era. Recently, in late 2017 PCV 13 had been introduced in India. In this scenario, genomic analysis of CC63 isolates both in IPD and carriage during pre and the PCV13 era will explain the evolutionary changes of CC63 in India.