Serotype replacement and mobile genetic elements in Streptococcus pneumoniae: a systematic review

Area of Science:

• Microbiology
• Epidemiology
• Genetics

Background:

• Streptococcus pneumoniae causes severe diseases like pneumonia and meningitis.
• Antimicrobial resistance (AMR) in S. pneumoniae is rising, driven by mobile genetic elements (MGEs).
• Pneumococcal conjugate vaccines (PCVs) reduced disease but led to non-vaccine serotype (NVT) increases.

Purpose of the Study:

• To analyze global serotype replacement patterns in S. pneumoniae.
• To investigate the role of MGEs in driving AMR in S. pneumoniae.
• To identify emerging multidrug-resistant NVTs.

Main Methods:

• Systematic review of 70 studies on pneumococcus, MGEs, and serotype replacement.
• Data analysis of geographical patterns and AMR prevalence.
• Literature search using predefined terms managed via COVIDENCE.

Main Results:

• PCV implementation reduced vaccine serotypes but increased NVTs globally.
• Tn916-like and Tn5253-like integrative and conjugative elements (ICEs) mobilize tetracycline and macrolide resistance.
• Multidrug-resistant NVTs (e.g., 15A, 15C, 23A) are emerging worldwide.

Conclusions:

• PCV success is challenged by serotype replacement and MGE-driven AMR.
• Urgent need for improved antimicrobial stewardship and serotype-independent vaccines.
• Dual challenges of AMR spread and serotype shifts require novel strategies.