Case study: discovery of a superbug

This report discusses the pan-resistant microbe, New Delhi Metallo-Beta-Lactamase-producing Klebsiella pneumoniae. It was resistant to all available antimicrobial drugs at the time. Klebsiella pneumoniae can be commensal in nature and is a part of normal flora of the mouth, skin, and intestines. However, a recent emergence in highly resistant strains has made treatment of infected wounds very difficult.

In August 2016, a 70-year old woman from Nevada presented with an infected right hip seroma and was diagnosed with systemic inflammatory response syndrome. Prior to this, she was on an extended visit to India, where she had had multiple hospitalisations due to a right femur fracture and subsequent osteomyelitis of the right femur and hip. Unfortunately, within a month of hospitalisation in the US, she developed septic shock and died.

Klebsiella pneumoniae was isolated from a wound specimen and was found to be a carbapenem-resistant enterobacteriaceae (CRE). The isolate was sent to Centers for Disease Control and Prevention (CDC) for testing to determine the mechanism of antimicrobial resistance, which confirmed the presence of New Delhi metallo-beta-lactamase (NDM). Antimicrobial susceptibility testing confirmed that the isolate was resistant to 26 antibiotics, including all aminoglycosides and polymyxins tested.

This case illustrates the importance of health care facilities obtaining a history of health care exposures outside their region upon admission and checking for CRE. When these bacteria are identified, appropriate infection control must be implemented to prevent transmission.

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