Epidemiological Genetic Study for Novel World Records of Hepatitis B Virus Strains Detected by DNA Sequences in the South of Iraq/Al-Basrah Province

Abstract

Hepatitis B virus (HBV) infection is one of the global and major health problems which possess a serious threat to humans and normally associated with the presence of hepatitis B surface antigen (HBsAg) (i.e. HBsAg small (S) protein particle). The small hepatitis B virus envelope protein S has the intrinsic ability to direct the morphogenesis of spherical 20-nm subviral lipoprotein particles. The DNA sequence analysis of hepatitis B virus surface protein S gene samples was amplified by PCR for 36 blood samples collected from Al-Basrah Province patients. Seven of 36 (19.4%) strains of HBV were identical (100%) to those previously isolated from Italy (1), Iran (3) and India (3), while the other 29 (80.6) strains which closely related with those strains from Sudan (24), India (2), Iran (1), Turkey (1) and Australia (1) were recorded in GenBank as novel strains in the world. In the present study, several point mutations in the sequence of s gene upon over-expression of full-length surface proteins, which may possibly contribute to HBV genome replication. These results suggest that indicated s gene rather than the surface protein was involved in regulation of HBV genome replication and could be developed into a safe and promising adjuvant of HB vaccine. The study investigation indicates that all new strains were closely related (99% identity) with the pervious mentioned global strains.