In the last part of this section, we show results computed in real-time in a video acquired in a non-controlled environment using our 3D-FE method.
An et al. explore in particular whether the theories of selective exposure and echo chamber can be observed in a non-controlled environment (as done in the past by traditional psychologists).
This report is one of the first studies on the short-term genome evolution of bacteria in a non-controlled environment, thus providing important information that may help in interpretation of data from laboratory evolution experiments.
Importantly, even in the unlikely scenario that the unique strain linked to listeriosis cases in 1998 and 2000 was reintroduced, rather than having persisted in the plant, the isolates characterized here would still represent a set of closely related isolates with a parent-descendant relationship, which have multiplied in a non-controlled environment over about 12 years.
In order to evaluate these techniques in non-controlled environments, a collection of standard databases, well known in the surveillance research community, has been used: PETS 2006, PETS 2007, PETS 2009 and CAVIAR.
However, evaluation of large quality improvement programmes is complicated due to changing, non-controlled environments.
Overall, our data indicate that short term evolution of L. monocytogenes in natural non-controlled environments involves limited diversification of the genomic backbone, but can involve considerable phage-mediated diversification as well as plasmid loss or gain.
Consequently, there is a need to better understand L. monocytogenes diversification in non-controlled environments and to develop improved subtyping approaches that can be used in follow-up studies to routine subtyping using PFGE.
Short-term evolution of L. monocytogenes in non-controlled environments appears to involve limited diversification beyond plasmid gain or loss and prophage diversification, highlighting the importance of phages in bacterial evolution.
Rather than single base-pair mutations or rearrangements in the genomic backbone, diversification in prophage sequences, and possibly plasmid loss and acquisition (as also supported by data from others [ 21]), seem to represent the major drivers of diversification in L. monocytogenes in non-controlled environments.
Determination of genome sequences for three L. monocytogenes isolates obtained from foods and human listeriosis cases linked to a single food processing facility, in conjunction with a previously reported genome sequence for a food isolate linked to the same facility [ 28], provided a unique resource to gain insight into the short-term evolution of L. monocytogenes in non-controlled environments.
