Epidemiological characteristics and antibiotic resistance mechanisms of Streptococcus pneumoniae: An updated review

Streptococcus pneumoniae (S. pneumoniae, pneumococcus) is a Gram-positive bacterium, which can cause a variety of diseases including otitis media, nasosinusitis, pneumonia, bacteremia and meningitis. To prevent and control pneumococcus diseases, pneumococcal conjugate vaccines (PCVs) were developed and widely implemented worldwide. The introduction of PCVs reduced the infections caused by PCV serotypes, while serotype replacements affected vaccine effectiveness. S. pneumoniae has developed resistance to multiple antibiotics including penicillin, macrolides, fluoroquinolone, and sulfamethoxazole-trimethoprim. In turn, infections caused by antibiotic resistant strains can affect the treatment of related diseases. Genetic functional studies, molecular detection, and molecular characterization of newly identified mechanisms have been updated in recent years. Hence, this review aims to summarize the serotype distribution, epidemiology and antibiotic resistance mechanism of S. pneumoniae in the vaccine era. A greater understanding of the epidemiological features and antibiotic resistance mechanisms could ultimately assist clinical treatment and prevent the spread of antibiotic resistance strains.