EN
The purpose of the study was to attempt the application of flow cytometry to evaluate the sensitivity of various cell lines to EAV infections, according to their type and passage number. Monolayers of RK13, Vero, BHK-21 and MDBK cells were infected with reference EAV strain Bucyrus. First of all the susceptibility of each cell line to different titers of the virus was tested. The second step was to establish a time course kinetic of viral infection. Sequentially, starting from 2 to 72 hours post infection the cells were fixed, permeabilized and stained with FITC monoclonal EAV-specific antibodies. The analysis carried out in Coulter Epics XL (Beckman Coulter) flow cytometer considered the percentage of EAV infected cells determined in a time range by gating FITC/Count histograms. Significant differences in the sensitivity to EAV infection in particular cell lines were found. After 24 h. p.i. most RK13 cells infected with Bucyrus strain showed signs of infection in the titer of 10 TCID₅₀, whilst in Vero and BHK-21 a similar histogram was not obtained until 100 and 1000 TCID₅₀ respectively. As early as 10 and 12 h post inoculation significant level of infected cells (37.9 and 18.6%) were detected in line RK13 passage 36 and 11 respectively. Cell line Vero passage 115 indicated a higher sensitivity to EAV infection comparing to Vero passage 153. More than 70% of cells from that line were EAV infected after 24 hours post inoculation. In Vero passage 153 the infected cells (15.4%) were not detected until 36 h.p.i. The presence of infected cells was found also after 36 h post inoculation in BHK-21 cell line passage 10. The obtained results indicate that differences in cell line susceptibility to EAV infection depend on their type and decrease with their passage.