Increased growth ability and pathogenicity of American- and Pacific-subtype Zika virus (ZIKV) strains compared with a...

Area of Science:

• Virology
• Infectious Diseases
• Pathogen Biology

Background:

• Zika virus (ZIKV) poses a significant public health threat.
• Understanding ZIKV strain variations is crucial for assessing disease risk.
• Asian/American lineage strains exhibit distinct genetic and geographic origins.

Purpose of the Study:

• To compare the in vitro growth properties and in vivo virulence of three distinct ZIKV strains from the Asian/American lineage.
• To evaluate the impact of different ZIKV subtypes on viral replication, viremia, and testicular pathology in a mouse model.

Main Methods:

• In vitro viral growth assays were performed for PRVABC59, ChibaS36, and NIID123 ZIKV strains.
• Mice were inoculated with ZIKV strains to assess viremia levels and infectious virus presence in testes.
• Histopathological examination of testes and detection of ZIKV NS1 antigen were conducted post-inoculation.

Main Results:

• The American subtype strain PRVABC59 demonstrated the highest in vitro growth, while the Southeast Asian subtype strain NIID123 showed the lowest.
• PRVABC59 infection resulted in the highest viremia and infectious virus levels in testes, alongside increased testicular damage.
• ZIKV NS1 antigen was detected in damaged testes and epididymides, particularly in PRVABC59 and ChibaS36 infected mice.

Conclusions:

• ZIKV strains PRVABC59 and ChibaS36 exhibit enhanced in vitro and in vivo replication capabilities.
• These strains demonstrate a greater potential to cause testicular damage in mice compared to NIID123.
• Strain-specific differences in ZIKV growth and virulence are significant, impacting pathogenesis and potential for reproductive complications.