Superbug Resistant to All Available Antimicrobials

Microbiologist holding open Petri dish
Microbiologist holding open Petri dish
A Nevada woman was found to be infected with a pan-resistant superbug.

A carbapenem-resistant Enterobacteriaceae (CRE) has been identified and is resistant to all available antibiotics in the United States, according to a report published in the Morbidity and Mortality Weekly Report.

A woman in her 70s from Washoe County Health District in Reno, Nevada, was admitted to an acute care hospital in early August 2016 after an extended visit to India. The specific CRE, Klebsiella pneumoniae, was isolated from a wound and sent for testing to the Centers for Disease Control and Prevention, which confirmed the presence of New Delhi metallo-beta-lactamase.

The patient had been hospitalized multiple times in India for management of a right femur fracture and subsequent osteomyelitis of the right femur and hip. Before the US hospitalization in August, she was last hospitalized in India in June 2016.

Antimicrobial susceptibility testing confirmed that the isolate was resistant to all 26 antibiotics, including colistin. Results were negative for the mcr-1 gene. The “isolate had a relatively low fosfomycin [minimum inhibitory concentration] of 16 μg/mL by ETEST,” but fosfomycin is “approved in the United States only as an oral treatment of uncomplicated cystitis.”

Subsequent sampling of rectal swab specimens from other patients admitted to the same unit did not identify additional CRE.

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Chen L, Todd R, Kiehlbauch J, Walters M, Kallen A. Notes from the field: pan-resistant New Delhi metallo-beta-lactamase-producing Klebsiella pneumoniae – Washoe County, Nevada, 2016. MMWR Morb Mortal Wkly Rep. 2017;66:33. doi: 10.15585/mmwr.mm6601a7