Serratia marcescens: A Versatile Opportunistic Pathogen with Emerging Clinical and Biotechnological Significance

Serratia marcescens is a Gram-negative opportunistic pathogen renowned for its extensive ecological versatility and clinical significance. Once considered a benign saprophyte, it has now been recognized as a notable etiological agent in nosocomial infections, predominantly affecting immunocompromised hosts. Its pathogenicity is mediated by an array of virulence determinants, including hemolysins, proteolytic enzymes, siderophores, and the biosynthesis of the pigmented secondary metabolite prodigiosin, which exhibits notable anticancer and immunomodulatory activities. S. marcescens exhibits proficient biofilm-forming capabilities that underpin persistent device colonization and confer resilience against antimicrobial therapies. Beyond its clinical impact, S. marcescens is of interest in industrial biotechnology and environmental bioremediation applications. This comprehensive review delineates current insights into its taxonomy, virulence pathways, antimicrobial resistance mechanisms, and emerging biotechnological utilities, emphasizing the dual challenges and opportunities it presents to microbiology and therapeutic development.