Revolutionizing respiratory tract infections diagnosis: From gram stain to next-generation sequencing

Abstract

Introduction: Respiratory tract infections remain a leading cause of morbidity and mortality worldwide, burdening healthcare systems and promoting antimicrobial resistance. Accurate and timely diagnosis is vital for effective management and infection control. Over time, diagnostic modalities have evolved from microscopy and culture to molecular and genomic methods, redefining clinical microbiology. Aim and Objective: To review the evolution of respiratory tract infections diagnostics from traditional to molecular and genomic techniques, highlighting their strengths, limitations, and roles in improving accuracy, clinical outcomes, and antimicrobial stewardship. Discussion: Conventional methods like Gram staining and culture are simple and cost-effective but suffer from limited sensitivity and delayed results. Immunoassays offered rapid detection but covered few pathogens. Molecular tools, especially PCR and multiplex panels, revolutionized pathogen detection with enhanced speed and specificity. Next-Generation Sequencing (NGS) and metagenomics now enable unbiased identification of both known and novel pathogens, though high cost and data complexity limit routine use. Artificial intelligence integration promises faster, automated, and more precise diagnostics in the near future. Conclusion: The shift from Gram stain to NGS marks a transition from morphological to precision-based microbiology. A hybrid diagnostic model combining conventional and molecular tools can optimize accuracy and cost-effectiveness. Broader accessibility, affordability, and data standardization will be essential for equitable implementation of advanced diagnostics worldwide.