Introduction and spread of NDM-producing Enterobacterales and Acinetobacter baumannii into Middle Eastern countries: a molecular-based hypothesis

Introduction: The goal of this review is to provide a plausible explanation for the dissemination of NDM-producing Enterobacterales (NDME) and Acinetobacter baumannii (NDMAb) across the ME. Areas covered: We described and analyzed (1) the initial reports of NDME and NDMAb in ME countries; (2) the most contemporary data regarding the epidemiology of NDME and NDMAb in ME countries; and (3) the molecular features of NDME and NDMAb in ME countries. Expert opinion: NDMAb first appeared in the Eastern Mediterranean and the Gulf States in 2009–2010. Although no connection to the Indian subcontinent could be traced, evidence for transmission within the region was found. The spread of NDMAb was mainly by clonal transmission, and it remained limited to less than 10% of the total CRAb population. NDME most likely had evolved from NDMAb and appeared later in the ME. Subsequently, the spread of NDME was mainly via the transmission of the bla_NDM gene into several Klebsiella pneumoniae and Escherichia coli successful clones that had served before as recipient to various bla_ESBLgenes. The most recent epidemiological situation varied widely, from 20.7% of carbapenem-resistant Enterobacterales (CRE) in Saudi Arabia to 80.5% in Egypt.