Emergence of New Delhi metallo-β-lactamase type 1-producing enterobacteriaceae and non-enterobacteriaceae: global case detection and bacterial surveillance.

OBJECTIVE: A systematic review of the literature was conducted to summarize the descriptive and molecular epidemiology of human cases and surveillance reports with New Delhi metallo-β-lactamase type 1 (NDM-1)-producing bacteria reported worldwide from January 2008 through July 6, 2011.
METHODS: A comprehensive literature review was conducted to identify publications of NDM-1-producing bacteria. Studies were divided into two broad categories of (1) case series and case reports of NDM-1-producing bacteria, or (2) active surveillance and environmental surveillance studies of NDM-1-producing bacteria.
RESULTS: Sixty cases with NDM-1-producing bacteria were reported in the 3.5-year interval since the index case detection. The majority of reported cases represented colonization without evidence of infection (n=39, 65%); urine was the most common specimen source for cases with infection (41.7%) and colonization (33.3%). Seventeen cases (28.3%) had NDM-1-producing bacteria at more than one body site. Klebsiella pneumoniae and Escherichia coli were the most frequent bacteria detected, and the multilocus sequence type data from 34 E. coli and K. pneumoniae clinical isolates provided an incomplete, yet heterogeneous global distribution of NDM-1-producing bacteria. The majority of cases (63.3%) had exposure to the Indian subcontinent of south central Asia, and laboratory surveillance systems, as well as an environmental survey from India, suggest a presence of environmental reservoirs for potential human infection and colonization with NDM-1-producing bacteria.
CONCLUSIONS: The majority of case reports with NDM-1-producing bacteria had presumed colonization, not infection, with one or more bacteria. The available human case reports and surveillance data suggest a global distribution of NDM-1-producing Enterobacteriaceae and non-Enterobacteriaceae.