These results clearly indicate a genetic difference between different strains of PAO1.
Another possibility that should be considered is the existence of small differences between different strains of the same specie as recently exposed by Ribeiro et al. [ 78] and by Dietrich et al. [ 79].
As the copy number of a species-specific repeat might differ between different strains of the same species, the median value of copies of particular repeat in the analyzed strains of particular species was used as the copy number of a given repeat.
While the initial sequencing of chlamydial genomes has provided important insights into the general biology of the chlamydiae, reconciling the minor genetic differences between different strains of the same species with particular diseases, hosts and sites of infection has been more challenging.
Furthermore, efficacy in the acute phase varies with the geographical area, probably because of differences in susceptibility between different strains of T. cruzi [ 2].
In experimental infections, significant differences in pathogenicity between different strains of S. dysgalactiae [ 35], as well as between different strains of S. uberis [ 36], have been shown in the past, and another option may be to study long-term outcome after experimental infections of isolates of different genotypes.
A similar variation rate for A. versicolor might explain the observed difference in Cq values between different strains of this species.
Finally, Apsegaite and Skirkevicius [31] found slight differences in the quantity of 9-ODA between different strains of honey bees, suggesting that genotypic differences might also alter pheromone profiles.
Other miRNAs specific to MAB-S-infected cells have also been found to differ in their expression levels between different strains of MTB (miR-99b and miR-140) or between latent and active tuberculosis (miR-877) [ 54].
Even between different strains of the same species considerable differences may exist.
