Tn4453a is a chloramphenicol resistance transposon similar to Tn4451. The chloramphenicol resistance is mediated by catD gene. It was detected in Clostridium difficile. The Tn4453a was found to be co-existed with another transposon, Tn4453b in C. difficile.
Lyras, D., Storie, C., Huggins, A. S., Crellin, P. K., Bannam, T. L., & Rood, J. I. (1998). Chloramphenicol resistance in Clostridium difficile is encoded on Tn4453 transposons that are closely related to Tn4451 from Clostridium perfringens. Antimicrobial Agents and Chemotherapy, 42(7), 1563-1567. DOI: PMCID: PMC105645