Within patient horizontal gene transfer dynamics of a blaNDM-7 plasmid among four different bacterial species.

PURPOSE: We describe the case of a 73-year old male who was found to be a carrier of an blaNDM -producing Citrobacter freundii shortly after admission. During his admission, he developed abdominal abscesses and received multiple courses of piperacillin-tazobactam. In the following months, he was found to carry three other carbapenemase-positive species: Klebsiella oxytoca, Raoultella planticola and Serratia marscescens.

RESULTS

Two of these strains had clustering carbapenem-sensitive isolates cultured before. The species all carried an blaNDM-7 encoding incX3 plasmid, which demonstrated horizontal gene transfer within this patient.

CONCLUSION

This case report underlines the importance of mobile genetic elements in infection control, as they serve as transmission vehicles for antimicrobial resistance beyond the spread of identical bacterial strains.