Capsular typing of Streptococcus pneumoniae isolated from clinical specimens in Gauhati Medical College and hospital, Assam, India

Purpose: Streptococcus pneumoniae is an important human respiratory tract pathogen causing pneumococcal dis-eases in majority of children and adults. The capsule is a significant virulence factor of Pneumococci which de-termines the bacterial serotype and is the component used for synthesis of pneumococcal vaccines. This cross-sectional study aimed to isolate Streptococcus pneumoniae from clinical samples and determine the occurrence of its circulating serotypes in Assam, North East India.Materials and methods: A total of 80 clinical samples were collected from June 2019 to May 2020 from patients clinically suspected from pneumococcal infection and also included samples routinely sent to bacteriology lab-oratory. Isolation and identification of S. pneumoniae was performed using conventional culture and molecular methods. Antibiotic susceptibility patterns were monitored. Capsular serotyping was performed using PCR of cpsA gene followed by DNA sequencing.Results: Majority of the cases suspected of pneumococcal infection belong to the paediatric group aged less than 5 years. Out of 80 samples, 10 (12.50%) were found to be positive by PCR of recP gene. Culture was positive in 80% (8/10) of the total positives. Co-trimoxazole resistance was seen in 33.33% of the isolate from sputum. Serotypes 6A, 6B, 6C and 19F were detected in our region, out of which 6C is a non-vaccine serotype.Conclusion: Continued surveillance is needed to monitor trends in non-vaccine serotypes that may emerge as highly associated with antibiotic resistance. Also, the need to continuous monitoring of the antibiotic suscepti-bility of S. pneumoniae in North eastern parts of India is of outmost importance.