Emergence and global spread ofListeria monocytogenesmain clinical clonal complex

Abstract

AbstractRetracing microbial emergence and spread is essential to understanding the evolution and dynamics of pathogens. The bacterial foodborne pathogenListeria monocytogenesclonal complex 1 (Lm-CC1) is the most prevalent clonal group associated with listeriosis, and is strongly associated with cattle and dairy products. Here we analysed 2,021Lm-CC1 isolates collected from 40 countries, since the firstLmisolation to the present day, to define its evolutionary history and population dynamics. Our results suggest thatLm-CC1 spread worldwide from North America following the Industrial Revolution through two waves of expansion, coinciding with the transatlantic livestock trade in the second half of the 19thcentury and the rapid growth of cattle farming in the 20thcentury.Lm-CC1 then firmly established at a local level, with limited inter-country spread. This study provides an unprecedented insight intoLm-CC1 phylogeography and dynamics and can contribute to effective disease surveillance to reduce the burden of listeriosis.