Comparison of Antimicrobial Susceptibility Patterns of Streptococcus pneumoniae Respiratory Isolates: Systematic...

Streptococcus pneumoniae acquiring multidrug resistance globally, which poses a threat to the effective treatment of respiratory infections. This systematic review and meta-analysis aimed to evaluate global and regional antimicrobial susceptibility patterns of S. pneumoniae respiratory isolates collected between 2015 and 2024.

Scopus, PubMed and Web of Science were searched from January 2015 to December 2024 following PRISMA guidelines. Inclusion criteria comprised English-language original studies reporting antibiotic susceptibility rates of S. pneumoniae isolated from respiratory samples of human origin, while studies with fewer than 10 isolates or lacking clear specification of sample type were excluded. Participants were respiratory samples yielding S. pneumoniae from human subjects across six WHO-defined regions. No interventions were applied, as this was an observational synthesis of surveillance and observational studies. Study quality was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Prevalence Studies. A random-effects model with double arcsine transformation was applied to pool susceptibility proportions, and subgroup analyses were conducted by geographical region.

Thirty-three studies comprising 20,768 isolates were included. Overall susceptibility rates were highest for linezolid (100%) and vancomycin (99%). Penicillin susceptibility was 77% (95% CI: 65-88), but markedly lower in the African (61%) and Eastern Mediterranean (26%) regions. Erythromycin (35%) and tetracycline (42%) susceptibility showed significant declines in the Western Pacific region (3% and 11%, respectively). Trimethoprim-sulfamethoxazole (48%) and clindamycin (60%) also displayed regional variability. Sensitivity analyses restricted to low-risk studies confirmed the robustness of findings.

Antimicrobial susceptibility of S. pneumoniae respiratory isolates varies substantially by region. These results support the importance of regional antibiotic stewardship strategies and updated treatment guidelines to address declining susceptibility and emerging resistance patterns.