Partial sequence at 2BC region of HAV isolated from stool of acute sporadic HAV patients.

More than 20 hepatitis A virus (HAV) strains that can be distinguished from each other are known till now. In the present study, a cytopathic strain of HAV (HA-10) was isolated in Egypt from stool of acute sporadic cases. The isolated strain showed CPE in early stages of adaptation in cell culture. Accordingly, the first step in the work was to confirm the presence of HAV, the second step was to prove that no enteric virus is associated with the isolate and finally to try to know the reason for that rapid adaptation in cell culture. So, RT-PCR was carried out for different regions of the viral RNA (5'ntr, VP1, VP1/2A, 2B and 2B/2C) also, enterovirus primers (5'ntr) were used. Reference HAV strains such as HM-175, HAS-15, MBB and 18F were used for comparison. Segment of 2BC region of the viral RNA was sequenced and compared with the nucleotide sequence of the reference HAV strains at the same region. The results revealed that HA-10 isolate react with all HAV primers and similar in this behavior with 18F and HM-175 strains. The nucleotide sequencing showed that there are 16 mutations in HA-10, two of them in 2B and the others in 2C region which may explain the reason for the highly adaptation of HA-10 isolate than 18F. As a result of this study, HA-10 may give us a highlight on HAV replication and also, the isolated strain may be useful for vaccine development.