Molecular and Clinical Study of Clostridium perfringens in Gas Gangrene: Genetic Variations and Virulence Factors

Abstract

Gas gangrene, or clostridial myonecrosis, remains one of the most rapidly progressive and life-threatening soft-tissue infections, predominantly caused by Clostridium perfringens. This study investigates the molecular and clinical characteristics of C. perfringens isolates recovered from confirmed gas gangrene cases, with a focus on genetic diversity, toxin gene profiles, and key virulence determinants. Clinical samples were obtained from patients undergoing surgical debridement, followed by anaerobic culture, whole-genome sequencing, and comprehensive toxinotyping. Molecular analysis demonstrated substantial genomic variability among isolates, particularly in the distribution of plasmid-encoded virulence genes. The plc gene encoding alpha-toxin—an indispensable factor in myonecrosis—was consistently detected, while additional genes such as pfoA (perfringolysin O), colA (collagenase), and nanH (neuraminidase) varied in presence and expression levels. Gene expression assays revealed differential regulation of major toxins under host-mimicking conditions, highlighting the influence of environmental cues and the VirS/VirR regulatory system. Clinically, patients exhibited rapidly evolving symptoms characterized by severe pain, tissue necrosis, systemic toxicity, and gas formation. Correlation analysis showed that isolates with broader toxin repertoires and higher expression levels of plc and pfoA were associated with more severe clinical outcomes, including increased rates of amputation and intensive care admission. Host-cell interaction assays confirmed the synergistic cytotoxic effects of alpha-toxin and perfringolysin O on endothelial and muscle cells, supporting their central role in vascular collapse and rapid tissue destruction. This study underscores the importance of integrating molecular diagnostics with clinical assessment to improve early recognition and management of gas gangrene. Understanding the genetic and virulence profiles of C. perfringens may enable the development of rapid detection tools, targeted therapies, and preventive strategies.