The considerable diversity we observed within a single epidemiological strain set, confirms that EAEC are indeed very heterogeneous and demonstrates that the EAEC pathotype, as presently defined, is comprised of E. coli strains whose defining superior colonization phenotype does not reflect a common ancestry or even a manageable number of clonal groups.
For epidemiological strain comparison, MP isolates from patients from two other seasons and locations were also DNA sequenced and genotyped.
The ideal microbial typing technique should enable differentiation of epidemiological unrelated strains and group epidemiological related (outbreak) strains, [ 2] and give information that will help to understand the evolutionary history of multiple strains within a clonal lineage [ 1, 2].
Another important point coming from the present student is the utility of WGS for epidemiological surveillance and strain typing.
This may be the result of epidemiological circumstances or strain differences in their ability to survive, spread and cause disease under Norwegian conditions.
Despite the technical difficulties in data analysis, as WGS costs converge towards the cost of MIRU-VNTR, the former is likely to replace MIRU-VNTR as the gold-standard for molecular epidemiological surveillance and strain typing.
Compensatory evolution restoring in vivo fitness, as well as social and behavior factors, may have played a role in the epidemiological persistence of strain M. The intracellular replication of the pathogen and its spread from the lungs to other sites occur before the development of adaptive immune responses.
The epidemiological relationship between strains colonizing healthy children and strains causing pneumococcal infections has been documented before, so surveillance studies of pneumococcal carriage allow monitoring strains circulating in community, including their antibiotic resistance.
PCR MP proved a repeatable and specific method for differentiation of Salmonella strains, showing a discriminatory power high enough to identify the real epidemiological links between strains.
The fact that strains with identical genotyping patterns can accumulate significant amounts of genetic diversity indicates that epidemiological links between strains with identical genotyping data can be more remote and are likely to represent older transmission events rather than cases of recent transmission among patients in one RFLP cluster[62].
This need exists for epidemiological studies of outbreak strains, where strain discrimination is the primary focus, as well as for population genetic studies where genomic information is of central importance.
