Replication of CHIKV (IMT isolate) in HeLa cells. (a) Ultrastructural analysis of mock-infected HeLa cells. Under high magnification, the cellular organelles such as the Golgi apparatus (GA) and mitochondria (M), can be seen. The bar corresponds to 0.2 μm. (b) Infection of CHIKV in HeLa cells. Viral-induced membranous spheres are observed to associate with the plasma membrane [boxed]. The bar corresponds to 0.2 μm. (c) CPV II complexes were detected at 12 hours post infection. The viral nucleocapsids (arrows) were observed to be budding in the CPV II complexes. The bar of c corresponds to 0.5 μm. (d) Massive accumulation of mature CHIKV (arrows) in infected cells at late infection. The bar corresponds to 0.5 μm.