Acquisition and Loss of CTX-M-Producing and Non-Producing Escherichia coli in the Fecal Microbiome of Travelers to South Asia.

Over 80% of travelers from the United Kingdom to the Indian subcontinent acquire CTX-M-producing (CTX-M-EC), but the mechanism of CTX-M-EC acquisition is poorly understood. We aimed to investigate the dynamics of CTX-M-EC acquisition in healthy travelers and how this relates to populations of non-CTX-M-EC in the fecal microbiome. This is a prospective observational study of healthy volunteers traveling from the United Kingdom to South Asia.

Global epidemiology of CTX-M β-lactamases: temporal and geographical shifts in genotype.

Globally, rates of ESBL-producing Enterobacteriaceae are rising. We undertook a literature review, and present the temporal trends in blaCTX-M epidemiology, showing that blaCTX-M-15 and blaCTX-M-14 have displaced other genotypes in many parts of the world. Explanations for these changes can be attributed to: (i) horizontal gene transfer (HGT) of plasmids; (ii) successful Escherichia coli clones; (iii) ESBLs in food animals; (iv) the natural environment; and (v) human migration and access to basic sanitation.