Figure 6. Comparison of EV-D68 strain-specific growth characteristics in primary human enteroids.

Primary enteroids grown on Matrigel (A, B) or transwells (C–F) were infected with 10⁶ PFU of the indicated EV-D68 strains: MD/09/23229 (orange), IL/14/18952 (burgundy), MA/18/23089 (pink), or KY/14/18953 (blue) and incubated at 33°C (A) or 37°C (B–F) for the indicated hours post-infection (hpi). For intestinal cells grown on transwells, cells were infected from either the apical (C, E) or basolateral (D, F) surfaces. Supernatants were sampled at the indicated hpi from both apical (C, D) or basolateral (E, F) compartments and titers determined by TCID50 assays. Titers are shown as mean ± standard deviation from three independent replicates. Dotted line denotes limit of assay detection. (G), Summary table denotes titer at 72 hpi, + corresponds to 10³, ++ 10⁴, +++ 10⁵, and ++++ 10⁶, NT not tested. Significance determined by one-way ANOVA. *p<0.05, **p<0.005, ns, not significant.