Molecular characterisation of streptococcus pneumoniae clinical isolates at a major tertiary hospital in Klang Valley

Chang, Li Wen (2022) Molecular characterisation of streptococcus pneumoniae clinical isolates at a major tertiary hospital in Klang Valley. [Project Paper] (Submitted)

Text FPSK2 2022 43.pdf Download (2MB)

Abstract

Streptococcus pneumoniae is a major human pathogen that normally colonises and becomes part of the normal flora of the human upper respiratory tracts. However, it has the potential to cause several diseases such as sinusitis, acute otitis media, pneumonia and bacterial meningitis under favourable conditions. Although studies have addressed the serotypes and sequence types (ST) distribution of S. pneumoniae among Malaysians, the information about the genetic background of S. pneumoniae clinical isolates at local settings remains scarce. Objective: This study aims to investigate the genotypic characteristics of S. pneumonia clinical isolates at a major tertiary hospital in Klang Valley based on sequence type (ST). Hypothesis: It is hypothesised that the most common ST of the clinical isolates is associated with the globally dominant lineages, especially those in South East Asia. Methodology: Pre-characterised clinical isolates of S. pneumoniae from a major tertiary hospital were re-identified through gram staining, catalase test, optochin susceptibility test and bile solubility test. Molecular identification by Ply and LytA gene expression and serotyping were conducted. 10 clinical isolates were eligible for further analyse by Multilocus Sequence Typing (MLST). Phylogenetics analysis was then conducted to investigate the genetic relatedness among the S. pneumoniae clinical isolates. Result & Discussion: 19F (n=10), 6A/B (n=7) and 19A (n=6) are the most common serotypes identified. The most common ST is ST320 (n=3), a globally disseminated sequence type that is predominant in Asia. Other STs such as ST695, ST90, ST271, ST81, ST5872 and ST9 were about equally distributed. ST16499 (n=1) is a novel ST found in this study. All the clinical isolates are genetically closely related to each other in their respective clusters corresponding to their STs. Conclusion: The presence of S. pneumoniae globally disseminated strains in this study provides an insight to stricten the vaccination policy in entering Malaysia. However, larger surveillance program on the ST distributions of S. pneumoniae around Malaysia are necessary to enhance the insights in the building of vaccination policy.

Item Type:	Project Paper
Faculty:	Faculty of Medicine and Health Science
Depositing User:	Ms. Nor Safa'aton Saidin
Date Deposited:	14 Feb 2024 07:36
Last Modified:	14 Feb 2024 07:36
URI:	http://psaspb.upm.edu.my/id/eprint/1393

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