AN ANALYSIS OF ANTIMICROBIAL RESISTANCE AND EPIDEMIOLOGICAL EVOLUTIONARY DYNAMICS OF STREPTOCOCCUS PNEUMONIAE

Abstract

Streptococcus pneumoniae remains one of the most clinically significant bacterial pathogens worldwide, being the predominant etiological agent in community-acquired pneumonia, among other infections of considerable relevance. Therapeutic efficacy against pneumococcal infections has been progressively compromised by the emergence and dissemination of strains resistant to multiple classes of antimicrobials. This challenge is further exacerbated by the phenomenon of serotype replacement, a direct consequence of the selective pressure imposed by mass vaccination with pneumococcal conjugate vaccines (PCVs), which, although successful in reducing disease caused by vaccine-covered serotypes, have facilitated the rise of frequently multidrug-resistant non-vaccine serotypes. This complex interplay between pathogen evolution, antimicrobial use, and immunization strategies compromises host response, hinders clinical recovery, and increases the costs associated with treatment. This article presents an in-depth, descriptive literature review exploring the multifaceted problem of pneumococcal resistance, addressing microbiological, epidemiological, and clinical aspects, with emphasis on molecular resistance mechanisms, biofilms as a virulence and persistence factor, the dynamics of serotype replacement, and the pathogen’s immune evasion strategies. The analysis highlights the importance of integrated surveillance strategies, rational antibiotic use, and continuous vaccine updates to curb the spread of resistant strains. Understanding these aspects is essential for clinical management, prevention, and the formulation of public health policies, in addition to outlining future perspectives for the control of pneumococcal infections in pharmaceutical, medical, and public health practice.