THE MAIN DIFFERENCES BETWEEN GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA, STRUCTURAL, FUNCTIONAL, AND CLINICAL IMPLICATIONS – A NARRATIVE REVIEW

Abstract

Gram-positive and Gram-negative bacteria constitute the two main taxonomic groups of bacteria, classified based on structural differences in their cell wall, as evidenced by the Gram staining technique. These structural differences determine significant variations in physiological, biochemical, pathogenic, and antimicrobial response aspects. The presence or absence of an outer membrane, the composition of peptidoglycan, virulence mechanisms, and antimicrobial resistance systems confer distinct characteristics to each group, directly impacting the diagnosis, treatment, and control of bacterial infections. This narrative review aims to discuss in an integrated manner the main differences between Gram-positive and Gram-negative bacteria, addressing structural and functional aspects, pathogenicity mechanisms, antimicrobial resistance, and clinical implications, highlighting their relevance to medical microbiology and clinical practice.