Emerging Corynebacterium Species Infections in the Shadow of Radiation Therapy: A Case Series in Cancer Patients

Corynebacterium species are increasingly recognized as opportunistic pathogens in immunocompromised hosts. We report three cases of culture-confirmed Corynebacterium infections in cancer patients undergoing radiation therapy at a tertiary care centre. Two patients developed Corynebacterium striatum skin and soft tissue infections and one had Corynebacterium matruchotii vaginal infection. All cases presented with foul-smelling discharge and delayed wound healing in previously irradiated tissues. Identification was performed using MALDI-TOF MS (Bruker Biotyper®) and standard microbiological methods. Direct Gram stain of all specimens revealed gram-positive, pleomorphic rod-shaped bacilli. Antimicrobial susceptibility testing confirmed susceptibility to linezolid in all isolates, and culture-guided therapy with linezolid resulted in rapid clinical improvement. These cases highlight the importance of recognizing Corynebacterium species as true pathogens rather than contaminants in immunocompromised cancer patients.