Pneumococcal Conjugate Vaccine (PCV) use has resulted in decrease of vaccine serotypes (VTs) and emergence of non-vaccine types (NVTs). We applied whole genome sequence (WGS) to predict serotype, sequence type (ST) and antibiotic resistance of NVT invasive pneumococcal isolates collected during the pre-vaccine era from Indian population.
96 NVT invasive isolates (2009-2017) collected across the country were sequenced on Illumina platform. Bioinformatic pipelines SeroBA and CDC pneumococcal pipeline for AMR calls were used for data analysis.
Serotypes 15B (n=11), 24 (n=9) were dominant NVT types followed by 8 (n=8) and 34,10A,11A,16F (n=5). MLST resolved strains into 67 known STs. ST13727 (n=6) and ST2234 (n=5) were most common. Strains clustered in 45 clonal complexes and 16 singletons. The dominant clonal complex CC230 (n=12) was from serotypes 15B,15C,24,10A and 11A. 78(81%) of isolates were multidrug-resistant. Resistance genes for tetracycline (n=44), cotrimoxazole (n=41), erythromycin (n=34), penicillin (n=13) and chloramphenicol (n=2) were identified.
With the introduction of PCV in 2018 in national immunization program our data provides information for post-vaccination assessments. With higher valency vaccines coming to market by Indian manufacturers, knowledge of PCV13 NVT disease is important to identify serotypes to expand vaccine coverage in India.